publicationDate,title,abstract,id
2021-07-16,Influence of inter-sublattice coupling on the terahertz nutation spin dynamics in antiferromagnets,"Spin nutation resonance has been well-explored in one-sublattice
ferromagnets. Here, we investigate the spin nutation in two-sublattice
antiferromagnets as well as, for comparison, ferrimagnets with inter-and
intra-sublattice nutation coupling. In particular, we derive the susceptibility
of the two-sublattice magnetic system in response to an applied external
magnetic field. To this end, the antiferromagnetic and ferrimagnetic (sub-THz)
precession and THz nutation resonance frequencies are calculated. Our results
show that the precession resonance frequencies and effective damping decrease
with intra-sublattice nutation coupling, while they increase with inter
-sublattice nutation in an antiferromagnet. However, we find that the THz
nutation resonance frequencies decrease with both the intra-and
inter-sublattice nutation couplings. For ferrimagnets, conversely, we calculate
two nutation modes with distinct frequencies, unlike antiferromagnets. The
exchange-like precession resonance frequency of ferrimagnets decreases with
intra-sublattice nutation coupling and increases with inter-sublattice nutation
coupling, like antiferromagnets, but the ferromagnetic-like precession
frequency of ferrimagnets is practically invariant to the intra and
inter-sublattice nutation couplings.",2107.07939v2
2000-12-19,Significance of the direct relaxation process in the low-energy spin dynamics of a one-dimensional ferrimagnet NiCu(C_7H_6N_2O_6)(H_2O)_3 2H_2O,"In response to recent nuclear-magnetic-resonance measurements on a
ferrimagnetic chain compound NiCu(C_7H_6N_2O_6)(H_2O)_3 2H_2O [Solid State
Commun. {\bf 113} (2000) 433], we calculate the nuclear spin-lattice relaxation
rate 1/T_1 in terms of a modified spin-wave theory. Emphasizing that the
dominant relaxation mechanism arises from the direct (single-magnon) process
rather than the Raman (two-magnon) one, we explain the observed temperature and
applied-field dependences of 1/T_1. Ferrimagnetic relaxation phenomena are
generally discussed and novel ferrimagnets with extremely slow dynamics are
predicted.",0012342v1
2019-07-10,Temperature dependence of magnetic resonance in ferrimagnetic GdFeCo alloys,"We provide a macroscopic theory and experimental results for magnetic
resonances of antiferromagnetically-coupled ferrimagnets. Our theory, which
interpolates the dynamics of antiferromagnets and ferromagnets smoothly, can
describe ferrimagnetic resonances across the angular momentum compensation
point. We also present experimental results for spin-torque induced
ferrimagnetic resonance at several temperatures. The spectral analysis based on
our theory reveals that the Gilbert damping parameter, which has been
considered to be strongly temperature dependent, is insensitive to temperature.
We envision that our work will facilitate further investigation of
ferrimagnetic dynamics by providing a theoretical framework suitable for a
broad range of temperatures.",1907.04540v1
2023-04-26,Direct observation of Néel-type skyrmions and domain walls in a ferrimagnetic DyCo$_3$ thin film,"Isolated magnetic skyrmions are stable, topologically protected spin textures
that are at the forefront of research interests today due to their potential
applications in information technology. A distinct class of skyrmion hosts are
rare earth - transition metal (RE-TM) ferrimagnetic materials. To date, the
nature and the control of basic traits of skyrmions in these materials are not
fully understood. We show that for an archetypal ferrimagnetic material
DyCo$_3$ that exhibits a strong perpendicular anisotropy, the ferrimagnetic
skyrmion size can be tuned by an external magnetic field. Moreover, by taking
advantage of the high spatial resolution of scanning transmission X-ray
microscopy (STXM) and utilizing a large x-ray magnetic linear dichroism (XMLD)
contrast that occurs naturally at the RE resonant edges, we resolve the nature
of the magnetic domain walls of ferrimagnetic skyrmions. We demonstrate that
through this method one can easily discriminate between Bloch and N\'eel type
domain walls for each individual skyrmion. For all isolated ferrimagnetic
skyrmions, we observe that the domain walls are of N\'eel-type. This key
information is corroborated with results of micromagnetic simulations and
allows us to conclude on the nature of the Dzyaloshinskii-Moriya interaction
(DMI) which concurs to the stabilisation of skyrmions in this ferrimagnetic
system. Establishing that an intrinsic DMI occurs in RE-TM materials will also
be beneficial towards a deeper understanding of chiral spin texture control in
ferrimagnetic materials.",2304.13698v2
2021-10-23,Optical interface for a hybrid magnon-photon resonator,"We study optical detection of magnetic resonance of a ferrimagnetic sphere
resonator, which is strongly coupled to a microwave loop gap resonator. Optical
fibers are employed for coupling the sphere resonator with light in the telecom
band. We find that magnetic resonance can be optically detected in the region
of anti-crossing between the loop gap and the ferrimagnetic resonances. By
measuring the response time of the optical detection we rule out the
possibility that microwave induced heating is responsible for the optical
detectability.",2110.13644v1
2022-07-21,Unusual ferrimagnetism in CaFe2O4,"Incomplete cancellation of collinear antiparallel spins gives rise to
ferrimagnetism. Even if the oppositely polarized spins are owing to the equal
number of a single magnetic element having the same valence state, in
principle, a ferrimagnetic state can still arise from the crystallographic
inequivalence of the host ions. However, experimental identification of such a
state as ferrimagnetic is not straightforward because of the tiny magnitude
expected for M and the requirement for a sophisticated technique to
differentiate similar magnetic sites. We report a synchrotron-based resonant
x-ray investigation at the Fe L2,3 edges on an epitaxial film of CaFe2O4, which
exhibits two magnetic phases with similar energies. We find that while one
phase of CaFe2O4 is antiferromagnetic, the other one is ferrimagnetic with an
antiparallel arrangement of an equal number of spins between two distinct
crystallographic sites with very similar local coordination environments. Our
results further indicate two distinct origins of an overall minute M; one is
intrinsic, from distinct Fe3+ sites, and the other one is extrinsic, arising
from defective Fe2+ likely forming weakly-coupled ferrimagnetic clusters. These
two origins are uncorrelated and have very different coercive fields. Hence,
this work provides a direct experimental demonstration of ferrimagnetism solely
due to crystallographic inequivalence of the Fe3+ as the origin of the weak M
of CaFe2O4.",2207.10775v1
2019-09-19,Magnetization dynamics of the compensated ferrimagnet $Mn_{2}Ru_{x}Ga$,"Here we study both static and time-resolved dynamic magnetic properties of
the compensated ferrimagnet from room temperature down to 10K, thus crossing
the magnetic compensation temperature $T_{M}$. The behaviour is analysed with a
model of a simple collinear ferrimagnet with uniaxial anisotropy and
site-specific gyromagnetic ratios. We find a maximum zero-applied-field
resonance frequency of $\sim$160GHz and a low intrinsic Gilbert damping
$\alpha$$\sim$0.02, making it a very attractive candidate for various
spintronic applications.",1909.09085v1
2021-11-16,Ultrathin ferrimagnetic GdFeCo films with very low damping,"Ferromagnetic materials dominate as the magnetically active element in
spintronic devices, but come with drawbacks such as large stray fields, and low
operational frequencies. Compensated ferrimagnets provide an alternative as
they combine the ultrafast magnetization dynamics of antiferromagnets with a
ferromagnet-like spin-orbit-torque (SOT) behavior. However to use ferrimagnets
in spintronic devices their advantageous properties must be retained also in
ultrathin films (t < 10 nm). In this study, ferrimagnetic Gdx(Fe87.5Co12.5)1-x
thin films in the thickness range t = 2-20 nm were grown on high resistance
Si(100) substrates and studied using broadband ferromagnetic resonance
measurements at room temperature. By tuning their stoichiometry, a nearly
compensated behavior is observed in 2 nm Gdx(Fe87.5Co12.5)1-x ultrathin films
for the first time, with an effective magnetization of Meff = 0.02 T and a low
effective Gilbert damping constant of {\alpha} = 0.0078, comparable to the
lowest values reported so far in 30 nm films. These results show great promise
for the development of ultrafast and energy efficient ferrimagnetic spintronic
devices.",2111.08768v1
2023-12-27,Sublattice-selective inverse Faraday effect in ferrimagnetic rare-earth iron garnet,"We performed time-resolved pump--probe measurements using rare-earth iron
garnet \ce{Gd3/2Yb1/2BiFe5O12} as a two-sublattice ferrimagnet. We measured the
initial phases of the magnetic resonance modes below and above the
magnetization compensation temperature to clarify the sublattice selectivity of
the inverse Faraday effect in ferrimagnets. A comparison of the time evolution
of magnetization estimated using the equations of motion revealed that the
inverse Faraday effect occurring in ferrimagnetic materials has sublattice
selectivity. This is in striking contrast to antiferromagnets, in which the
inverse Faraday effect acts on each sublattice identically. The initial phase
analysis can be applied to other ferrimagnets with compensation temperatures.",2312.16553v1
2018-08-17,Laser-induced antiferromagnetic-like resonance in amorphous ferrimagnets,"The magnetization dynamics for ferrimagnets at the angular momentum
compensation temperature T_A is believed to be analogous to that for
antiferromagnets. We investigated the pulsed-laser-induced magnetization
dynamics in amorphous rare-earth transition-metal ferrimagnet films with a T_A
just above room temperature. For a low pulse fluence, the magnetization
precession frequency decreases as the applied magnetic field increases, whereas
for a higher pulse fluence, it increases as the applied field increases. The
result was well explained by the left-handed and right-handed precession modes
of the antiferromagnetic-like resonance at temperatures below and above T_A,
respectively, and the data were in agreement with the theoretical simulation.
The study demonstrated the experimental route to achieving antiferromagnetic
resonance in ferrimagnets using a pulsed laser.",1808.05707v1
2013-05-14,Ferrimagnetic Spin Wave Resonance and Superconductivity in Carbon Nanotubes,"The phenomenon of ferrimagnetic spin wave resonance [uncompensated
antiferromagnetic spin wave resonance] has been detected for the first time. It
has been observed in carbon nanotubes, produced by high energy ion beam
modification of diamond single crystals in $\ <{100}\ >$ direction.
Peculiarities of spin wave resonance observed allow to insist on the formation
in given nanotubes of $s^+$ superconductivity at room temperature, coexisting
with uncompensated antiferromagnetic ordering.",1305.3256v1
2017-03-22,Fast domain wall motion induced by antiferromagnetic spin dynamics at the angular momentum compensation temperature of ferrimagnets,"Antiferromagnetic spintronics is an emerging research field which aims to
utilize antiferromagnets as core elements in spintronic devices. A central
motivation toward this direction is that antiferromagnetic spin dynamics is
expected to be much faster than ferromagnetic counterpart because
antiferromagnets have higher resonance frequencies than ferromagnets. Recent
theories indeed predicted faster dynamics of antiferromagnetic domain walls
(DWs) than ferromagnetic DWs. However, experimental investigations of
antiferromagnetic spin dynamics have remained unexplored mainly because of the
immunity of antiferromagnets to magnetic fields. Furthermore, this immunity
makes field-driven antiferromagnetic DW motion impossible despite rich physics
of field-driven DW dynamics as proven in ferromagnetic DW studies. Here we show
that fast field-driven antiferromagnetic spin dynamics is realized in
ferrimagnets at the angular momentum compensation point TA. Using rare-earth
3d-transition metal ferrimagnetic compounds where net magnetic moment is
nonzero at TA, the field-driven DW mobility remarkably enhances up to 20 km/sT.
The collective coordinate approach generalized for ferrimagnets and atomistic
spin model simulations show that this remarkable enhancement is a consequence
of antiferromagnetic spin dynamics at TA. Our finding allows us to investigate
the physics of antiferromagnetic spin dynamics and highlights the importance of
tuning of the angular momentum compensation point of ferrimagnets, which could
be a key towards ferrimagnetic spintronics.",1703.07515v1
2021-05-13,Thermal instability in a ferrimagnetic resonator strongly coupled to a loop-gap microwave cavity,"We study nonlinear response of a ferrimagnetic sphere resonator (FSR)
strongly coupled to a microwave loop gap resonator (LGR). The measured response
in the regime of weak nonlinearity allows the extraction of the FSR Kerr
coefficient and its cubic damping rate. We find that there is a certain range
of driving parameters in which the system exhibits instability. In that range,
self-sustained modulation of the reflected power off the system is generated.
The instability is attributed to absorption-induced heating of the FSR above
its Curie temperature.",2105.06102v2
2016-10-08,Perpendicularly magnetized CoFeB multilayers with tunable interlayer exchange for synthetic ferrimagnets,"A study of the multilayer system MgO/CoFeB(1.1nm)/Ta($t$)/CoFeB(0.8nm)/MgO is
presented, where the two CoFeB layers are separated by a Ta interlayer of
varying thickness $t$. The magnetization properties deduced from complementary
techniques such as superconducting quantum interference magnetometry,
ferromagnetic resonance frequency measurements and Brillouin light scattering
spectroscopy can be tuned by changing the Ta thickness between $t$=0.25 nm, 0.5
nm and 0.75 nm. For $t$=0.5 nm, a ferromagnetic coupling is observed, whereas
for t=0.75 nm, the antiferromagnetic coupling needed to construct a synthetic
ferrimagnet is realized. In the later case, the shape of magnetic domain walls
between two ferrimagnetic alignments or between a ferro- and a ferrimagnetic
alignment is very different. This behavior can be interpreted as a result of
the change in dipolar as well as interlayer exchange energy and domain wall
pinning, which is an important conclusion for the realization of data storage
devices based on synthetic ferri- and antiferromagnets.",1610.02550v1
2023-02-06,Observation of Coherently Coupled Cation Spin Dynamics in an Insulating Ferrimagnetic Oxide,"Many technologically useful magnetic oxides are ferrimagnetic insulators,
which consist of chemically distinct cations. Here, we examine the spin
dynamics of different magnetic cations in ferrimagnetic NiZnAl-ferrite
(Ni$_{0.65}$Zn$_{0.35}$Al$_{0.8}$Fe$_{1.2}$O$_4$) under continuous microwave
excitation. Specifically, we employ time-resolved x-ray ferromagnetic resonance
to separately probe Fe$^{2+/3+}$ and Ni$^{2+}$ cations on different sublattice
sites. Our results show that the precessing cation moments retain a rigid,
collinear configuration to within $\approx$2$^\circ$. Moreover, the effective
spin relaxation is identical to within $<$10% for all magnetic cations in the
ferrite. We thus validate the oft-assumed ``ferromagnetic-like'' dynamics in
resonantly driven ferrimagnetic oxides, where the magnetic moments from
different cations precess as a coherent, collective magnetization.",2302.03100v1
2023-05-04,Effective rectification of THz electromagnetic fields in a ferrimagnetic iron garnet,"It is found that single-cycle THz electromagnetic fields efficiently excite a
GHz spin resonance mode in ferrimagnetic Tm$_3$Fe$_5$O$_{12}$, despite the near
absence of GHz spectral components in the exciting THz pulse. By analyzing how
the efficiency of excitation depends on the orientation and strength of the THz
electric field, we show that it can be explained in terms of the nonlinear THz
inverse Cotton-Mouton effect. Here, the THz electric field gets effectively
rectified and acts on the ferrimagnetic spins as a uni-polar effective magnetic
field pulse. This interpretation is confirmed by a theoretical model based on
the phenomenological analysis of the effective magnetic field, combined with
the equations of motion derived from the effective Lagrangian for a
ferrimagnet. Moreover, by using the outcome of two-dimensional THz
spectroscopy, we conjecture a quantum-mechanical interpretation of the observed
effect in terms of stimulated Raman scattering of THz photons by the
crystal-field split f-f electronic transitions of Tm$^{3+}$.",2305.02971v1
2009-03-11,Ferrimagnetic-like surface resonance from hybrid metamaterial slab,"We show that a hybrid metamaterial slab comprising of an one-dimensional
array of two different types of cavities exhibits ferrimagnetic-like surface
resonances which can be used to realize interesting phenomena such as directive
emission as a consequence of strong angle-dependent reflection phase and the
selective coupling of a Gaussian incident beam into a higher order diffractive
channel, giving rise to the phenomenon of negative reflection and
retro-directive backtracking. The findings are verified by experiments in the
microwave regime.",0903.1907v2
2020-05-20,Frequency mixing in a ferrimagnetic sphere resonator,"Frequency mixing in ferrimagnetic resonators based on yttrium and calcium
vanadium iron garnets (YIG and CVBIG) is employed for studying their nonlinear
interactions. The ferrimagnetic Kittel mode is driven by applying a pump tone
at a frequency close to resonance. We explore two nonlinear frequency mixing
configurations. In the first one, mixing between a transverse pump tone and an
added longitudinal weak signal is explored, and the experimental results are
compared with the predictions of the Landau-Zener-Stuckelberg model. In the
second one, intermodulation measurements are employed by mixing pump and signal
tones both in the transverse direction for studying a bifurcation between a
stable spiral and a stable node attractors. Our results are applicable for
developing sensitive signal receivers with high gain for both the radio
frequency and the microwave bands.",2005.09864v1
2010-06-10,NMR study on the stability of the magnetic ground state in MnCr${}_2$O${}_4$,"The canting angles and fluctuation of the magnetic ion spins of spinel oxide
MnCr${}_2$O${}_4$ were studied by nuclear magnetic resonance (NMR) at low
temperatures, which has a collinear ferrimagnetic order below $T_C$ and a
ferrimagnetic spiral order below $T_s < T_C$. Contrary to previous reports,
only one spin canting angle of Cr ions was observed. The spin canting angles of
Mn and Cr ions in the ferrimagnetic spiral obtained at a liquid-He temperature
were $43\,^{\circ}$ and $110\,^{\circ}$, respectively. The nuclear spin-spin
relaxation was determined by the Suhl-Nakamura interaction at low temperatures
but the relaxation rate $T_2^{-1}$ increases rapidly as the temperature
approaches $T_s$. This indicates that the fluctuation of the spiral component
becomes faster as the temperature increases but not fast enough to leave an
averaged hyperfine field to nuclei in the time scale of nuclear spin precession
in the ferrimagnetic phase, which is on the order of $10^{-8}$ s. The spiral
volume fraction measured for various temperatures reveals that the collinear
and the spiral ferrimagnetic phases are mixed below the transition temperature
of the spiral order. The temperature hysteresis in the volume fraction implies
that this transition has first-order characteristics.",1006.1983v1
2017-10-07,Dissecting spin-phonon equilibration in ferrimagnetic insulators by ultrafast lattice excitation,"To gain control over magnetic order on ultrafast time scales, a fundamental
understanding of the way electron spins interact with the surrounding crystal
lattice is required. However, measurement and analysis even of basic collective
processes such as spin-phonon equilibration have remained challenging. Here, we
directly probe the flow of energy and angular momentum in the model insulating
ferrimagnet yttrium iron garnet. Following ultrafast resonant lattice
excitation, we observe that magnetic order reduces on distinct time scales of 1
ps and 100 ns. Temperature-dependent measurements, a spin-coupling analysis and
simulations show that the two dynamics directly reflect two stages of
spin-lattice equilibration. On the 1-ps scale, spins and phonons reach
quasi-equilibrium in terms of energy through phonon-induced modulation of the
exchange interaction. This mechanism leads to identical demagnetization of the
ferrimagnet's two spin-sublattices and a novel ferrimagnetic state of increased
temperature yet unchanged total magnetization. Finally, on the much slower,
100-ns scale, the excess of spin angular momentum is released to the crystal
lattice, resulting in full equilibrium. Our findings are relevant for all
insulating ferrimagnets and indicate that spin manipulation by phonons,
including the spin Seebeck effect, can be extended to antiferromagnets and into
the terahertz frequency range.",1710.02700v2
2021-03-09,Ultrafast demagnetization in a ferrimagnet under electromagnetic field funneling,"The quest to improve density, speed and energy efficiency of magnetic memory
storage has led to exploration of new ways of optically manipulating magnetism
at the ultrafast time scale, in particular in ferrimagnetic alloys. While
all-optical magnetization switching is well-established on the femtosecond
timescale, lateral nanoscale confinement and thus potential significant
reduction of the size of the magnetic element remains an outstanding challenge.
Here we employ resonant electromagnetic energy-funneling plasmon nanoantennas
to influence the demagnetization dynamics of a ferrimagnetic TbCo alloy thin
film. We demonstrate how Ag nanoring-shaped antennas under resonant optical
femtosecond pumping reduce the overall magneto-optical response due to
demagnetization in the underlying films up to three times compared to
non-resonant illumination. We attribute such substantial reduction to the
nanoscale confinement of the demagnetization process. This is qualitatively
supported by the electromagnetic simulations that strongly evidence the optical
energy-funneling to the nanoscale from the nanoantennas into the ferrimagnetic
film. This is the first and defining step for reaching deterministic ultrafast
all-optical magnetization switching at the nanoscale in such systems, opening a
route to develop nanoscale ultrafast magneto-optics.",2103.05365v1
2007-04-24,Element-resolved x-ray ferrimagnetic and ferromagnetic resonance spectroscopy,"We report on the measurement of element-specific magnetic resonance spectra
at gigahertz frequencies using x-ray magnetic circular dichroism (XMCD). We
investigate the ferrimagnetic precession of Gd and Fe ions in Gd-substituted
Yttrium Iron Garnet, showing that the resonant field and linewidth of Gd
precisely coincide with Fe up to the nonlinear regime of parametric
excitations. The opposite sign of the Gd x-ray magnetic resonance signal with
respect to Fe is consistent with dynamic antiferromagnetic alignment of the two
ionic species. Further, we investigate a bilayer metal film,
Ni$_{80}$Fe$_{20}$(5 nm)/Ni(50 nm), where the coupled resonance modes of Ni and
Ni$_{80}$Fe$_{20}$ are separately resolved, revealing shifts in the resonance
fields of individual layers but no mutual driving effects. Energy-dependent
dynamic XMCD measurements are introduced, combining x-ray absorption and
magnetic resonance spectroscopies.",0704.3139v2
2022-08-17,Polarization-selective magneto-optical modulation,"We study magneto-optical coupling in a ferrimagnetic sphere resonator made of
Yttrium iron garnet. We find that the resonator can be operated in the telecom
band as a polarization-selective optical modulator. Intermodulation gain can be
employed in the nonlinear regime for amplification.",2208.08148v2
2023-03-28,Exploring terahertz-scale exchange resonances in synthetic ferrimagnets with ultrashort optically induced spin currents,"Using spin currents generated by fs laser pulses, we demonstrate excitation
of GHz ferromagnetic resonance and THz ferrimagnetic exchange resonances in
Co/Gd/Co/Gd multilayers by time-resolved magneto-optic Kerr effect
measurements. Varying the Gd layer thickness allows for a tuning of the
resonance spectrum by manipulating the total angular momentum and strength of
effective exchange fields between the antiferromagnetically coupled layers.
Close to the compensation point of angular momentum, a minimum in the frequency
of the exchange-dominated mode and a maximum in the frequency of the
ferromagnetic resonance mode is observed. Finally, to gain better understanding
of the excitation mechanism, we analyze the anomalous variation in the measured
exchange mode amplitude as a function of its frequency. A peak in this
amplitude in the vicinity of the compensation point of angular momentum is
explained using a macrospin model, taking nonlinear effects at finite
precession amplitudes into account.",2303.15985v2
2015-10-23,Laser-induced THz magnetization precession for a tetragonal Heusler-like nearly compensated ferrimagnet,"Laser-induced magnetization precessional dynamics was investigated in
epitaxial films of Mn$_3$Ge, which is a tetragonal Heusler-like nearly
compensated ferrimagnet. The ferromagnetic resonance (FMR) mode was observed,
the precession frequency for which exceeded 0.5 THz and originated from the
large magnetic anisotropy field of approximately 200 kOe for this ferrimagnet.
The effective damping constant was approximately 0.03. The corresponding
effective Landau-Lifshitz constant of approximately 60 Mrad/s and is comparable
to those of the similar Mn-Ga materials. The physical mechanisms for the
Gilbert damping and for the laser-induced excitation of the FMR mode were also
discussed in terms of the spin-orbit-induced damping and the laser-induced
ultrafast modulation of the magnetic anisotropy, respectively.",1510.06793v1
2016-08-19,Competing Exchange Interactions in the Multiferroic and Ferrimagnetic CaBaCo$_4$O$_7$,"Competing exchange interactions can produce complex magnetic states together
with spin-induced electric polarizations. With competing interactions on
alternating triangular and kagome layers, the swedenborgite CBO may have one of
the largest measured spin-induced polarizations of about 1700 nC/cm$^2$ below
its ferrimagnetic transition temperature at 70 K. Powder neutron-diffraction
data, magnetization measurements, and spin-wave resonance frequencies in the
THz range reveal that the complex spin order of multiferroic CBO can be
described as a triangular array of c-axis chains ferrimagnetically coupled to
each other in the ab plane. Magnetostriction on bonds that couple those chains
produces the large spin-induced polarization of CBO.",1608.05628v3
2017-12-28,Charge ordering and ferrimagnetism in the strongly correlated $β$-V$_2$PO$_5$ single crystal,"A combined study of transport, thermodynamic, neutron diffraction, nuclear
magnetic resonance measurements and first principles calculation were performed
for $\beta$-V$_2$PO$_5$ single crystal. It was shown to be a semiconductor with
a band gap of 0.48 eV, undergoing a charge ordering (unusual V$^{2+}$ and
V$^{3+}$) phase transition accompanied by a tetragonal to monoclinic structural
distortion at 610 K and a paramagnetic to ferrimagnetic phase transition at 128
K with a propagation vector of $\textbf{k} = 0$. The easy axis is in the
monoclinic $ac$ plane pointing 47(9)$^\circ$ away from the monoclinic $a$ axis.
This collinear ferrimagnetic structure and anisotropic isothermal magnetization
measurements suggest weak magnetic anisotropy in this compound. The first
principles calculations indicate that the intra-chain interactions in the
face-sharing VO$_6$ chains dominate the magnetic hamiltonian and identify the
$\Gamma_5^+$ normal mode of the lattice vibration to be responsible for the
charge ordering and thus the structural phase transition.",1712.09973v1
2019-09-12,Magnetostrictively induced stationary entanglement between two microwave fields,"We present a scheme to entangle two microwave fields by using the nonlinear
magnetostrictive interaction in a ferrimagnet. The magnetostrictive interaction
enables the coupling between a magnon mode (spin wave) and a mechanical mode in
the ferrimagnet, and the magnon mode simultaneously couples to two microwave
cavity fields via the magnetic dipole interaction. The magnon-phonon coupling
is enhanced by directly driving the ferrimagnet with a strong red-detuned
microwave field, and the driving photons are scattered onto two sidebands
induced by the mechanical motion. We show that two cavity fields can be
prepared in a stationary entangled state if they are respectively resonant with
two mechanical sidebands. The present scheme illustrates a new mechanism for
creating entangled states of optical fields, and enables potential applications
in quantum information science and quantum tasks that require entangled
microwave fields.",1909.05936v3
2019-03-11,Exchange-enhanced Ultrastrong Magnon-Magnon Coupling in a Compensated Ferrimagnet,"The ultrastrong coupling of (quasi-)particles has gained considerable
attention due to its application potential and richness of the underlying
physics. Coupling phenomena arising due to electromagnetic interactions are
well explored. In magnetically ordered systems, the quantum-mechanical
exchange-interaction should furthermore enable a fundamentally different
coupling mechanism. Here, we report the observation of ultrastrong intralayer
exchange-enhanced magnon-magnon coupling in a compensated ferrimagnet. We
experimentally study the spin dynamics in a gadolinium iron garnet single
crystal using broadband ferromagnetic resonance. Close to the ferrimagnetic
compensation temperature, we observe ultrastrong coupling of clockwise and
anticlockwise magnon modes. The magnon-magnon coupling strength reaches more
than 30% of the mode frequency and can be tuned by varying the direction of the
external magnetic field. We theoretically explain the observed phenomenon in
terms of an exchange-enhanced mode-coupling mediated by a weak cubic
anisotropy.",1903.04330v2
2019-12-20,Picosecond spin-orbit torque switching of ferrimagnets,"Spintronics provides an efficient platform for realizing non-volatile memory
and logic devices. In these systems, data is stored in the magnetization of
magnetic materials, and magnetization is switched in the writing process. In
conventional spintronic devices, ferromagnetic materials are used which have a
magnetization dynamics timescale of around the nanoseconds, setting a limit for
the switching speed. Increasing the magnetization switching speed has been one
of the challenges in spintronic research. In this work we take advantage of the
ultrafast magnetization dynamics in ferrimagnetic materials instead of
ferromagnets, and we use femtosecond laser pulses and a photoconductive Auston
switch to create picosecond current pulses for switching the ferrimagnet. By
anomalous Hall and magneto-optic Kerr (MOKE) measurement, we demonstrate the
robust picosecond SOT driven magnetization switching of ferrimagnetic GdFeCo.
The time-resolved MOKE shows more than 50 GHz magnetic resonance frequency of
GdFeCo, indicating faster than 20 ps spin dynamics and tens of picosecond SOT
switching speed. Our work provides a promising route to realize picosecond
operation speed for non-volatile magnetic memory and logic applications.",1912.10129v1
2016-01-21,Spin pumping in strongly coupled magnon-photon systems,"We experimentally investigate magnon-polaritons, arising in ferrimagnetic
resonance experiments in a microwave cavity with a tuneable quality factor. To
his end, we simultaneously measure the electrically detected spin pumping
signal and microwave reflection (the ferrimagnetic resonance signal) of a
yttrium iron garnet (YIG) / platinum (Pt) bilayer in the microwave cavity. The
coupling strength of the fundamental magnetic resonance mode and the cavity is
determined from the microwave reflection data. All features of the magnetic
resonance spectra predicted by first principle calculations and an input-output
formalism agree with our experimental observations. By changing the decay rate
of the cavity at constant magnon-photon coupling rate, we experimentally tune
in and out of the strong coupling regime and successfully model the
corresponding change of the spin pumping signal. Furthermore, we observe the
coupling and spin pumping of several spin wave modes and provide a quantitative
analysis of their coupling rates to the cavity.",1601.05681v1
2008-10-27,Hybrid resonant phenomenon in a metamaterial structure with integrated resonant magnetic material,"We explore the hybridization of fundamental material resonances with the
artificial resonances of metamaterials. A hybrid structure is presented in the
waveguide environment that consists of a resonant magnetic material with a
characteristic tuneable gyromagnetic response that is integrated into a
complementary split ring resonator (CSRR) metamaterial structure. The combined
structure exhibits a distinct hybrid resonance in which each natural resonance
of the CSRR is split into a lower and upper resonance that straddle the
frequency for which the magnetic material's permeability is zero. We provide an
analytical understanding of this hybrid resonance and define an effective
medium theory for the combined structure that demonstrates good agreement with
numerical electromagnetic simulations. The designed structure demonstrates the
potential for using a ferrimagnetic or ferromagnetic material as a means of
creating a tunable metamaterial structure.",0810.4871v1
2008-08-14,Co-resonant enhancement of spin-torque critical currents in spin-valves with synthetic-ferrimagnet free-layer,"It is experimentally shown that the critical current for onset of spin-torque
instability in current-perpendicular-to-plane spin-valves can be strongly
enhanced using ""synthetic ferrimagnet"" free-layers of form FM1/Ru/FM2
(FM=ferrromagnet). However, this enhancement occurs for only one polarity of
bias current. A two-macrospin model is shown to reproduce the observations. The
model suggests that this phenomenon is related to a polarity-dependent,
spin-torque induced co-resonance between the two natural dynamic modes of the
FM1/FM2 couple. The resonance condition facilitates energy transfer out of the
spin-torque destabilized mode into the other stable mode whose effective
damping is actually enhanced by spin-torques, thereby delaying the onset of
instability of this coupled system to larger critical currents.",0808.2015v2
2018-08-25,Twisted magnetization states and inhomogeneous resonance modes in a Fe/Gd ferrimagnetic multilayer,"Static and dynamic magnetic properties of a ferrimagnetic
[Fe(35A)/Gd(50A)]x12 superlattice were investigated in a wide 4-300 K
temperature range using magneto-optical Kerr effect (MOKE) and ferromagnetic
resonance (FMR) techniques. The multilayer structure was sputtered on a
transparent glass substrate which made it possible to perform MOKE measurements
on both Fe and Gd terminated sides of the superlattice. These experiments
allowed us to detect a transition between field-aligned and canted magnetic
states on both sides of the film and to distinguish between the bulk and
surface twisted phases of the superlattice. As a result, the experimental H-T
magnetic phase diagram of the system was obtained. FMR studies at frequencies
7-36 GHz demonstrated a complex evolution of absorption spectra as temperature
decreased from room down to 4 K. Two spectral branches were detected in the
sample. Theoretical simulations show that the observed spectral branches
correspond to different types of inhomogeneous resonance modes in the
multilayer with non-uniform magnetization precession inside Gd layers.",1808.08466v1
2021-07-14,Ultrafast Optomagnonics in Ferrimagnetic Multi-Sublattice Garnets,"This review discusses the ultrafast magnetization dynamics within the
gigahertz to terahertz frequency range in ferrimagnetic rare-earth iron garnets
with different substitutions. In these garnets, the roles of spin-orbit and
exchange interactions have been detected using femtosecond laser pulses via the
inverse Faraday effect. The all-optical control of spin-wave and Kaplan-Kittel
exchange resonance modes in different frequency ranges is shown. Generation and
localization of the electric field distribution inside the garnet through the
metal-bound surface plasmon-polariton strongly enhance the amplitude of the
exchange resonance modes. The exchange resonance mode in yttrium iron garnets
was observed using circularly polarized Raman spectroscopy. The results of this
study may be utilized in the development of a wide class of optomagnonic
devices in the gigahertz to terahertz frequency range.",2107.06597v1
2021-08-16,Losses of Interface Waves in Plasmonic and Gyrotropic Structures,"The loss mechanisms of slow interface waves in the layered resonant media are
examined and illustrated by the examples of (i) surface plasmon polaritons in
an isotropic plasma layer, (ii) magnetoplasmons in magnetised plasma and (iii)
spin waves in ferrimagnetic layers. It is shown that losses of all these
interface waves grow at the same rate of Im(gamma) ~ Re(gamma^3), where gamma
is the wavenumber. These abnormal losses are caused by vortices of the power
flow of the interface waves near their resonance cut-off. The basic properties
of the slow interface waves discussed in the paper are inherent to the waves of
hyperbolic type in the layered resonant media.",2108.07180v1
2017-02-13,"Lieb and hole-doped ferrimagnetism, spiral, resonating valence-bond states, and phase separation in large-U $AB_{2}$ Hubbard chains","The ground state (GS) properties of the quasi-one-dimensional $AB_2$ Hubbard
model are investigated taking the effects of charge and spin quantum
fluctuations on equal footing. In the strong-coupling regime, we derive a
low-energy Lagrangian suitable to describe the ferrimagnetic phase at half
filling and the phases in the hole-doped regime. At half filling, a
perturbative spin-wave analysis allows us to find the GS energy, sublattice
magnetizations, and Lieb total spin per unit cell of the effective quantum
Heisenberg model, in very good agreement with previous results. In the
challenging hole doping regime away from half filling, we derive the
corresponding $t\textrm{-}J$ Hamiltonian. Under the assumption that charge and
spin quantum correlations are decoupled, the evolution of the second-order
spin-wave modes in the doped regime unveils the occurrence of spatially
modulated spin structures and the emergence of phase separation in the presence
of resonating-valence-bond states. We also calculate the doping-dependent GS
energy and total spin per unit cell, in which case it is shown that the spiral
ferrimagnetic order collapses at a critical hole concentration. Notably, our
analytical results in the doped regime are in very good agreement with density
matrix renormalization group studies, where our assumption of spin-charge
decoupling is numerically supported by the formation of charge-density waves in
anti-phase with the modulation of the magnetic structure.",1702.03609v4
2013-02-26,Resonant state selection in synthetic ferrimagnets,"Resonant activation of a synthetic antiferromagnet (SAF) is known to result
in a dynamic running state, where the SAF's symmetric spin-flop pair
continuously rotates between the two antiparallel ground states of the system,
with the two magnetic moments in-phase in the so-called acoustical
spin-resonance mode. The symmetry of an ideal SAF does not allow, however, to
deterministically select a particular ground state using a resonant excitation.
In this work, we study asymmetric SAF's, or synthetic ferrimagnets (SFi), in
which the two magnetic particles are different in thickness or are biased
asymmetrically with an external field. We show how the magnetic phase space of
the system can be reversibly tuned, post-fabrication, between the antiferro-
and ferri-magnetic behavior by exploiting these two asymmetry parameters and
applying a uniform external field. We observe a splitting of the optical
spin-resonance for the two ground states of the SFi system, with a frequency
spacing that can be controlled by a quasistatic uniform external field. We
demonstrate how the tunable magnetic asymmetry in SFi allows to
deterministically select a particular ground state using the splitting of the
optical spin-resonance. These results offer a new way of controlling the
magnetic state of a spin-flop bilayer, currently used in such large scale
applications as magnetic memory.",1302.6483v2
2009-09-25,"Electrical, magnetic, magnetodielectric and magnetoabsorption studies in multiferroic GaFeO3","We report electrical, magnetic, magnetodielectric and magnetoabsorption
properties of a polycrystalline GaFeO3. The resistivity measurement shows that
the sample is highly insulating below 200 K and the resistivity above 200 K
obey the Arrhenius law with an activation energy of Ea = 0.67 eV. An anomaly
occurs in the temperature dependence of permittivity (e) near the ferrimagnetic
transition temperature (TC = 228 K) in a zero magnetic field and it is
suppressed under H = 60 mT which indicates a possible magnetoelectric coupling
in GaFeO3 with a fractional change of de/e = -1.8% at 60 mT around TC. The
coercivity (HC) of the sample increases dramatically with lowering temperature
below 200 K from 0.1 T at 200 K to 0.9 T at 5 K. Magnetoabsorption was studied
with a LC resonance technique and we found a close correlation between the
shift in the resonance frequency due to applied magnetic field and the coercive
field measured using dc magnetization measurements. Our results obtained with
multiple techniques suggest that GaFeO3 is an interesting ferrimagnet with
potential applications in future multiferroic devices.",0909.4609v1
2016-07-11,Low loss spin wave resonances in organic-based ferrimagnet vanadium tetracyanoethylene thin films,"We experimentally demonstrate high quality factor spin wave resonances in an
encapsulated thin film of the organic-based ferrimagnet vanadium
tetracyanoethylene (V[TCNE]$_\textit{x~2}$) coated on an a-plane sapphire
substrate by low temperature chemical vapor deposition. The thickness standing
wave modes are observed in a broad frequency range (1 GHz ~ 5 GHz) with high
quality factor exceeding 3,200 in ambient air at room temperature, rivaling
those of inorganic magnetic materials. The exchange constant of
V[TCNE]$_\textit{x~2}$, a crucial material parameter for future study and
device design of the V[TCNE]$_\textit{x~2}$, is extracted from the measurement
with a value of $(4.61\pm 0.35)\times 10^{-16} \mathrm{\: m^{2}}$. Our result
establishes the feasibility of using organic-based materials for building
hybrid magnonic devices and circuits.",1607.03041v2
2018-11-30,Half-metallicity of Mn2VAl ferrimagnet revealed by resonant inelastic soft x-ray scattering under magnetic field,"Detailed information on the electronic states of both V and Mn 3d electrons
in the ferrimagnet Mn2VAl is obtained by the bulk sensitive resonant inelastic
soft x-ray scattering (SX-RIXS) excited with the circularly polarized light
under an external magnetic field for the first time. The results under the V
L-edge excitation have revealed the negligible partial density of states (PDOS)
of the V 3d states around the Fermi energy as well as their rather localized
character. Under the Mn L-edge excitation, on the other hand, the spectra are
dominated by fluorescence with clear magnetic circular dichroism with
noticeable excitation photon energy dependence. Compared with the theoretical
prediction of the RIXS spectra based on the density-functional-theory band
structure calculation, an itinerant, spin-dependent character of the Mn 3d
states and decays of the Mn 2p core states are confirmed in consistence with
the half-metallicity of the Mn 3d states.",1811.12600v1
2020-01-04,Observation of spin-motive force in ferrimagnetic GdFeCo alloy films,"Non-uniform magnetic structures produce emergent electromagnetic phenomena
such as the topological Hall effect and the spin-motive force (SMF). The
experimental reports on the SMF, however, are very few and the relationship
between the SMF and material parameters is still unclear. In this study, we
investigated the SMF in ferrimagnetic GdFeCo alloy films using the
spin-torque-induced ferromagnetic resonance method and clarified the
relationship. The amplitude of the detected SMF becomes larger than that of the
transition metal alloy FeCo by the Gd doping and reaches the maximum near a Gd
composition of the boundary between in-plane and perpendicularly magnetized
films. According to the analytical calculation, the enhancement is related to
the trajectory of the magnetization precession. Moreover, we find that the SMF
induced by the magnetic resonance is inversely proportional to the square of
the damping constant.",2001.01042v2
2019-12-25,Hybrid nanophotonic-nanomagnonic SiC-YiG quantum sensor: I/ theoretical design and properties,"Here I present the theory of a new hybrid paramagnetic-ferrimagnetic SiC-YiG
quantum sensor. It is designed to allow sub-nanoscale single external spin
sensitivity optically detected pulsed electron electron double resonance
spectroscopy, using an X band pulsed EPR spectrometer and an optical fiber. The
sensor contains one single V2 negatively charged silicon vacancy color center
in 4H-SiC, whose photoluminescence is waveguided by a 4H-SiC nanophotonic
structure towards an optical fiber. This V2 spin probe is created by ion
implantation at a depth of few nanometers below the surface, determined by
optically detected paramagnetic resonance under the strong magnetic field
gradient of a YiG ferrimagnetic nanostripe located on the back-side of the
nanophotonic structure. This gradient also allow the study, slice by slice at
nanoscale, of the target paramagnetic sample. The fabrication process of this
quantum sensor, its magnetic and optical properties, its external spins sensing
properties in a structural biology context, and its integration to a standard
commercially available pulsed EPR spectrometer are all presented here.",1912.11634v1
2021-06-03,"Relationship between A-site Cation and Magnetic Structure in 3d-5d-4f Double Perovskite Iridates Ln2NiIrO6 (Ln=La, Pr, Nd)","We report a comprehensive investigation of Ln2NiIrO6 (Ln = La, Pr, Nd) using
thermodynamic and transport properties, neutron powder diffraction, resonant
inelastic x-ray scattering, and density functional theory (DFT) calculations to
investigate the role of A-site cations on the magnetic interactions in this
family of hybrid 3d-5d-4f compositions. Magnetic structure determination using
neutron diffraction reveals antiferromagnetism for La2NiIrO6, a collinear
ferrimagnetic Ni/Ir state that is driven to long range antiferromagnetism upon
the onset of Nd ordering in Nd2NiIrO6, and a non-collinear ferrimagnetic Ni/Ir
sublattice interpenetrated by a ferromagnetic Pr lattice for Pr2NiIrO6. For
Pr2NiIrO6 heat capacity results reveal the presence of two independent magnetic
sublattices and transport resistivity indicates insulating behavior and a
conduction pathway that is thermally mediated. First principles DFT calculation
elucidates the existence of the two independent magnetic sublattices within
Pr2NiIrO6 and offers insight into the behavior in La2NiIrO6 and Nd2NiIrO6.
Resonant inelastic x-ray scattering is consistent with spin-orbit coupling
splitting the t2g manifold of octahedral Ir4+ into a Jeff = 1/2 and Jeff = 3/2
state for all members of the series considered.",2106.02025v1
2024-02-09,Level attraction in a quasi-closed cavity,"We provide a comprehensive analytical description of the effective coupling
associated with an antiresonance within a hybrid system comprised of a
quasi-closed photonic cavity and a ferrimagnetic material. Whilst so-called
level attraction between a resonant system inside an open cavity is well
understood, the physical underpinnings of this phenomena within quasi-closed
cavities have remained elusive. Leveraging the input-output theory, we
successfully differentiate between the repulsive and attractive aspects of this
coupling. Our proposed model demonstrates that by understanding the phase-jump
at the resonances and the studied antiresonance, we can predict the nature of
the effective coupling of the antiresonance for a given position of the
ferrimagnet in the cavity.",2402.06258v2
2019-03-11,Giant spin-orbit torque in a single ferrimagnetic metal layer,"Antiferromagnets and compensated ferrimagnets offer opportunities to
investigate spin dynamics in the 'terahertz gap' because their resonance modes
lie in the 0.3 THz to 3 THz range. Despite some inherent advantages when
compared to ferromagnets, these materials have not been extensively studied due
to difficulties in exciting and detecting the high-frequency spin dynamics,
especially in thin films. Here we show that spin-obit torque in a single layer
of the highly spin-polarized compensated ferrimagnet Mn2RuxGa is remarkably
efficient at generating spin-orbit fields \mu_0H_eff, which approach 0.1x10-10
T m2/A in the low-current density limit -- almost a thousand times the Oersted
field, and one to two orders of magnitude greater than the effective fields in
heavy metal/ferromagnet bilayers. From an analysis of the harmonic Hall effect
which takes account of the thermal contributions from the anomalous Nernst
effect, we show that the antidamping component of the spin-orbit torque is
sufficient to sustain self-oscillation. Our study demonstrates that spin
electronics has the potential to underpin energy-frugal, chip-based solutions
to the problem of ultra high-speed information transfer.",1903.04432v3
2022-04-20,Ferrimagnet GdFeCo characterization for spin-orbitronics: large field-like and damping-like torques,"Spintronics is showing promising results in the search for new materials and
effects to reduce energy consumption in information technology. Among these
materials, ferrimagnets are of special interest, since they can produce large
spin currents that trigger the magnetization dynamics of adjacent layers or
even their own magnetization. Here, we present a study of the generation of
spin current by GdFeCo in a GdFeCo/Cu/NiFe trilayer where the FeCo sublattice
magnetization is dominant at room temperature. Magnetic properties such as the
saturation magnetization are deduced from magnetometry measurements while
damping constant is estimated from spin-torque ferromagnetic resonance
(ST-FMR). We show that the overall damping-like (DL) and field-like (FL)
effective fields as well as the associated spin Hall angles can be reliably
obtained by performing the dependence of ST-FMR by an added dc current. The sum
of the spin Hall angles for both the spin Hall effect (SHE) and the spin
anomalous Hall effect (SAHE) symmetries are: $\theta_{DL}^{SAHE} +
\theta_{DL}^{SHE}=-0.15 \pm 0.05$ and $\theta_{FL}^{SAHE} +
\theta_{FL}^{SHE}=0.026 \pm 0.005$. From the symmetry of ST-FMR signals we find
that $\theta_{DL}^{SHE}$ is positive and dominated by the negative
$\theta_{DL}^{SAHE}$. The present study paves the way for tuning the different
symmetries in spin conversion in highly efficient ferrimagnetic systems.",2204.09776v1
2010-02-25,Ferromagnetic Resonance of Co/Gd and Co/Tb Multilayers,"The in-plane dynamics of ferrimagnetic Co/Gd multilayers are investigated by
means of ferromagnetic resonance, magneto-optical Kerr effect and SQUID
magnetometry. The power absorbed from these multilayers is strongly temperature
dependent. For example, the resonant peak for a (Co 40 A /Gd 40 A)8 multilayer
vanishes approximately 50 K below room temperature. We have further
investigated Gd/Co/Gd and Tb/Co/Tb trilayers with different thicknesses of Gd
(5-7 A), Tb (1-7 A) and Co (30-40 A). At room temperature, these Co-based
trilayers show a shift of approximately 600 Oe at 24 GHz in the uniform
ferromagnetic resonance field, compared to pure Co film, indicating the
exchange coupling between the Co and Gd. The shift in the field for the
resonance increases as the temperature is decreased. Furthermore the resonance
linewidth increases as the temperature is decreased. The experimental results
are in good agreement with our theoretical calculations.",1002.4889v1
2008-11-13,Selection rules for Single-Chain-Magnet behavior in non-collinear Ising systems,"The magnetic behavior of molecular Single-Chain Magnets is investigated in
the framework of a one-dimensional Ising model with single spin-flip Glauber
dynamics. Opportune modifications to the original theory are required in order
to account for reciprocal non-collinearity of local anisotropy axes and the
crystallographic (laboratory) frame. The extension of Glauber's theory to the
case of a collinear Ising ferrimagnetic chain is also discussed. Within this
formalism, both the dynamics of magnetization reversal in zero field and the
response of the system to a weak magnetic field, oscillating in time, are
studied. Depending on the geometry, selection rules are found for the
occurrence of slow relaxation of the magnetization at low temperatures, as well
as for resonant behavior of the a.c. susceptibility as a function of
temperature at low frequencies. The present theory applies successfully to some
real systems, namely Mn-, Dy-, and Co-based molecular magnetic chains, showing
that Single-Chain-Magnet behavior is not only a feature of collinear ferro- and
ferrimagnetic, but also of canted antiferromagnetic chains.",0811.2118v1
2015-04-08,Magnetic and nonmagnetic phases in doped AB2 t-J Hubbard chains,"We discuss the rich phase diagram of doped AB2 $t-J$ chains by using data
from density matrix renormalization group and exact diagonalization techniques.
The $J$ vs $\delta$ (hole doping) phase diagram exhibits regions of itinerant
ferrimagnetism, incommensurate, resonating valence bond and Nagaoka states,
phase separation, and Luttinger liquid (LL) physics. Several features are
highlighted, such as the modulated ferrimagnetic structure, the occurrence of
Nagaoka spin polarons in the underdoped regime and small values of $J=4t^2/U$,
where $t$ is the first-neighbor hopping amplitude and $U$ is the on-site
repulsive Coulomb interaction, incommensurate structures with nonzero
magnetization, and strong-coupling LL physics in the high-doped regime. We also
verify that relevant findings are in agreement with the corresponding findings
in square and n-leg ladder lattices. In particular, we mention the instability
of Nagaoka ferromagnetism against $J$ and $\delta$.",1504.01951v1
2015-08-06,Large spin-wave bullet in a ferrimagnetic insulator driven by spin Hall effect,"Due to its transverse nature, spin Hall effects (SHE) provide the possibility
to excite and detect spin currents and magnetization dynamics even in magnetic
insulators. Magnetic insulators are outstanding materials for the investigation
of nonlinear phenomena and for novel low power spintronics applications because
of their extremely low Gilbert damping. Here, we report on the direct imaging
of electrically driven spin-torque ferromagnetic resonance (ST-FMR) in the
ferrimagnetic insulator Y$_3$Fe$_5$O$_{12}$ based on the excitation and
detection by SHEs. The driven spin dynamics in Y$_3$Fe$_5$O$_{12}$ is directly
imaged by spatially-resolved microfocused Brillouin light scattering (BLS)
spectroscopy. Previously, ST-FMR experiments assumed a uniform precession
across the sample, which is not valid in our measurements. A strong spin-wave
localization in the center of the sample is observed indicating the formation
of a nonlinear, self-localized spin-wave `bullet'.",1508.01427v1
2016-07-25,Observation of an anisotropic Dirac cone reshaping and ferrimagnetic spin polarization in an organic conductor,"The Coulomb interaction among massless Dirac fermions in graphene is
unscreened around the isotropic Dirac points, causing a logarithmic velocity
renormalization and a cone reshaping. In less symmetric Dirac materials
possessing anisotropic cones with tilted axes, the Coulomb interaction can
provide still more exotic phenomena which have not been experimentally unveiled
yet. Here, using site-selective nuclear magnetic resonance, we find a
non-uniform cone reshaping accompanied by a bandwidth reduction and an emergent
ferrimagnetism in tilted Dirac cones that appear on the verge of charge
ordering in an organic compound. Our theoretical analyses based on the
renormalization-group approach and the Hubbard model show that these
observations are the direct consequences of the long-range and short-range
parts of the Coulomb interaction, respectively. The cone reshaping and the
bandwidth renormalization, as well as the novel magnetism revealed here, can be
ubiquitous and vital for many Dirac materials.",1607.07142v2
2013-08-06,Loop Liquid in an Ising-Spin Kondo Lattice Model on a Kagome Lattice,"Phase diagram of an Ising-spin Kondo lattice model on a kagome lattice is
investigated by a Monte Carlo simulation. We find that the system exhibits a
peculiar ferrimagnetic state at a finite temperature, in which each triangle is
in a two-up one-down spin configuration but the spin correlation does not
develop any superstructure. We call this state the loop liquid, as it is
characterized by the emergent degree of freedom, self-avoiding up-spin loops.
We elucidate that the system shows phase transitions from the loop liquid to
ferrimagnetically ordered states and a crossover to a partially ferromagnetic
state by changing the electron density and temperature. These can be viewed as
crystallization and cohesion of the loops, respectively. We demonstrate that
the loop formation is observed in the optical conductivity as a characteristic
resonant peak.",1308.1441v1
2012-01-03,Kondo Metal and Ferrimagnetic Insulator on the Triangular Kagomé Lattice,"We obtain the rich phase diagrams in the Hubbard model on the triangular
Kagom\'e lattice as a function of interaction, temperature and asymmetry, by
combining the cellular dynamical mean-field theory with the continuous time
quantum Monte Carlo method. The phase diagrams show the asymmetry separates the
critical points in Mott transition of two sublattices on the triangular
Kagom\'e lattice and produces two novel phases called plaquette insulator with
an obvious gap and a gapless Kondo metal. When the Coulomb interaction is
stronger than the critical value Uc, a short range paramagnetic insulating
phase, which is a candidate for the short rang resonating valence-bond spin
liquid, emerges before the ferrimagnetic order is formed independent of
asymmetry. Furthermore, we discuss how to measure these phases in future
experiments.",1201.0654v3
2018-10-02,Magnetocrystalline anisotropy and exchange probed by high-field anomalous Hall effect in fully-compensated half-metallic Mn2RuxGa thin films,"Magnetotransport is investigated in thin films of the half-metallic
ferrimagnet Mn$_2$Ru$_x$Ga in pulsed magnetic fields of up to 58 T. A
non-vanishing Hall signal is observed over a broad temperature range, spanning
the compensation temperature 155 K, where the net magnetic moment is strictly
zero, the anomalous Hall conductivity is 6673 $\Omega^{-1}.m^{-1}$ and the
coercivity exceeds 9 T. Molecular field modelling is used to determine the
intra- and inter-sublattice exchange constants and from the spin-flop
transition we infer the anisotropy of the electrically active sublattice to be
216 kJ/m$^3$ and predict the magnetic resonances frequencies. Exchange and
anisotropy are comparable and hard-axis applied magnetic fields result in a
tilting of the magnetic moments from their collinear ground state. Our analysis
is applicable to collinear ferrimagnetic half-metal systems.",1810.01158v1
2021-01-25,Raman Spectroscopy and Aging of the Low-Loss Ferrimagnet Vanadium Tetracyanoethylene,"Vanadium tetracyanoethylene (V[TCNE]$_{x}$, $x\approx 2$) is an organic-based
ferrimagnet with a high magnetic ordering temperature $\mathrm{T_C>600 ~K}$,
low magnetic damping, and growth compatibility with a wide variety of
substrates. However, similar to other organic-based materials, it is sensitive
to air. Although encapsulation of V[TCNE]$_{x}$ with glass and epoxy extends
the film lifetime from an hour to a few weeks, what is limiting its lifetime
remains poorly understood. Here we characterize encapsulated V[TCNE]$_{x}$
films using confocal microscopy, Raman spectroscopy, ferromagnetic resonance
and SQUID magnetometry. We identify the relevant features in the Raman spectra
in agreement with \textit{ab initio} theory, reproducing $\mathrm{C=C,C\equiv
N}$ vibrational modes. We correlate changes in the effective dynamic
magnetization with changes in Raman intensity and in photoluminescence. Based
on changes in Raman spectra, we hypothesize possible structural changes and
aging mechanisms in V[TCNE]$_x$. These findings enable a local optical probe of
V[TCNE]$_{x}$ film quality, which is invaluable in experiments where assessing
film quality with local magnetic characterization is not possible.",2101.10240v1
2017-05-09,Low spin wave damping in the insulating chiral magnet Cu$_{2}$OSeO$_{3}$,"Chiral magnets with topologically nontrivial spin order such as Skyrmions
have generated enormous interest in both fundamental and applied sciences. We
report broadband microwave spectroscopy performed on the insulating chiral
ferrimagnet Cu$_{2}$OSeO$_{3}$. For the damping of magnetization dynamics we
find a remarkably small Gilbert damping parameter of about $1\times10^{-4}$ at
5 K. This value is only a factor of 4 larger than the one reported for the best
insulating ferrimagnet yttrium iron garnet. We detect a series of sharp
resonances and attribute them to confined spin waves in the mm-sized samples.
Considering the small damping, insulating chiral magnets turn out to be
promising candidates when exploring non-collinear spin structures for high
frequency applications.",1705.03416v1
2017-05-29,Electronic Structure and Magnetic Properties of Half-metallic Ferrimagnet Mn$_{2}$VAl Probed by Soft X-ray Spectroscopies,"We have studied the electronic structure of ferrimagnetic Mn2VAl single
crystal by means of soft X-ray absorption spectroscopy (XAS), X-ray absorption
magnetic circular dichroism (XMCD) and resonant soft X-ray inelastic scattering
(RIXS). We have successfully observed the XMCD signals for all constitute
elements, supporting the spin polarized states at the Fermi level. The Mn
$L_{2,3}$ XAS and XMCD spectra are reproduced by the spectral simulation based
on density-functional theory (DFT), indicating itinerant character of the Mn 3d
states. On the other hand, V $3d$ electrons are rather localized since the
ionic model can qualitatively explain the V $L_{2,3}$ XAS and XMCD spectra as
well as the local dd excitation revealed by V $L_3$ RIXS.",1705.10027v2
2023-03-05,Electrical detection of antiferromagnetic dynamics in Gd-Co thin films by using a 154-GHz gyrotron irradiation,"THz magnetization dynamics is a key property of antiferromagnets as well as
ferrimagnets that could harness the THz forefront and spintronics. While most
of the present THz measurement techniques are for bulk materials whose
sensitivities rely on the volume of the material, measurement techniques
suitable for thin films are quite limited. In this study, we explored and
demonstrated electrical detection of the antiferromagnetic dynamics in
ferrimagnetic Gd-Co thin films by using a 154 GHz gyrotron, a high-power
electromagnetic wave source. Captured resonant modes allow us to characterize
the peculiar magnetization dynamics of the Gd-Co around the net angular
momentum compensation. As the gyrotron frequency is scalable up to THz, our
demonstration can be an important milestone toward the THz measurements for
antiferro- and ferri- magnetic thin films.",2303.02639v1
2012-06-04,Effects of Zeroline and Ferrimagnetic Fluctuation on Nuclear Magnetic Resonance for Dirac Electrons in Molecular Conductor alpha-(BEDT-TTF)2I3,"We re-examine the wave function of two-dimensional massless Dirac electron in
alpha-(BEDT-TTF)2I3 consisting of four molecules A, A', B and C in a unit cell,
using a tight-binding model. We find zerolines in the Brillouin zone, on which
the component of the wave function becomes zero for B or C sites. The
zerolines, which are bounded by two Dirac points at k0 and pass through the M-
or Y-points, result in a fact that the density of states of the B site exhibits
no the Van Hove singularity near the energy of the Dirac points. By taking
account of the on-site Coulomb interaction within the random phase
approximation, we examine the spin fluctuation in order to investigate
properties of the nuclear magnetic resonance for temperatures T > 50K. In the
region for 100 < T < 300K, it is shown that the Knight sift for B-site
monotonously decreases with decreasing temperature, owing to lack of the Van
Hove singularity, while it shows a maximum for the other sites (A, A' and C
sites). In the region for 50 < T < 100K, it is shown that the Knight sift is
convex downward and the Korringa ratio increases with decreasing temperature
for B-site. Such a behavior originates from the ferrimagnetic spin fluctuation
related to the zerolines. These results are consistent with those of the
nuclear magnetic resonance experiments.",1206.0527v1
2015-02-03,Generation of Spin Currents in the Skyrmion Phase of a Helimagnetic Insulator $\mathrm{Cu_2OSeO_3}$,"We report spin-current generation related with skyrmion dynamics resonantly
excited by a microwave in a helimagnetic insulator $\mathrm{Cu_2OSeO_3}$. A Pt
layer was fabricated on $\mathrm{Cu_2OSeO_3}$ and voltage in the Pt layer was
measured upon magnetic resonance of $\mathrm{Cu_2OSeO_3}$ to electrically
detect injected spin currents via the inverse spin Hall effect (ISHE) in Pt. We
found that ISHE-induced electromotive forces appear in the skyrmion phase of
$\mathrm{Cu_2OSeO_3}$ as well as in the ferrimagnetic phase, which shows that
magnetic skyrmions can contribute to the spin pumping effect.",1502.00742v1
2023-03-20,"Anapole, chiral and orbital states in Mn3Si2Te6","The ferrimagnet Mn3Si2Te6 attracts attention because of a recently discovered
colossal magnetoresistance (CMR) with unique magnetic field properties. An
improved magnetic structure for the material has emerged from a neutron
diffraction study linked to understanding the CMR. A deeper theoretical
investigation of the magnetic structure has now revealed anapole, chiral and
orbital states of manganese ions not previously mentioned. Moreover, it is
shown that existence of these states in the low temperature form of Mn3Si2Te6,
with a magnetic field applied, can be tested by neutron and resonant x-ray
diffraction.",2303.10979v2
2020-07-06,Ferrimagnetism in EuFe4As12 revealed by 153Eu NMR and 75As NQR measurements,"Filled skutterudite compound EuFe$_4$As$_{12}$ shows the highest magnetic
ordering temperature of $T_{\rm C}$ = 154 K among Eu-based skutterudite
compounds, but its magnetic ground state has not been determined yet. Here, we
performed $^{153}$Eu nuclear magnetic resonance (NMR) and $^{75}$As nuclear
quadrupole resonance (NQR) measurements on EuFe$_4$As$_{12}$ to reveal its
magnetic ground state as well as the physical properties from a microscopic
point of view. From the temperature and magnetic field dependence of $^{153}$Eu
NMR spectrum in the magnetically ordered state, we found that the Eu ions are
in Eu$^{2+}$ state with a nearly 7 $\mu_{\rm B}$ corresponding to $S$ = 7/2
spins. Combined with the magnetization measurements which show the reduced
saturation moments of 4.5 $\mu_{\rm B}$/f.u., we determined the ground magnetic
structure in EuFe$_4$As$_{12}$ to be ferrimagnetic where the Eu$^{2+}$ 4$f$ and
the Fe 3$d$ ordered moments are ferromagnetically aligned in each sublattice
but the moments between the sublattices are antiferromagnetically aligned. We
also found the local distortion at the Eu site from the cubic symmetry in the
magnetically ordered state. The relationship between the rattling motion of Eu
atoms and the local symmetry of the Eu ions is discussed. From the $^{75}$As
NQR nuclear spin-lattice relaxation time measurements as well as $^{153}$Eu NMR
measurements, we found that the 4$f$ electrons of the Eu ions are well
described by the local moment picture in both the magnetic and paramagnetic
metallic states.",2007.02983v1
2022-12-08,Strong photon-magnon coupling using a lithographically defined organic ferrimagnet,"We demonstrate a hybrid quantum system composed of superconducting resonator
photons and magnons hosted by the organic-based ferrimagnet vanadium
tetracyanoethylene (V[TCNE]$_x$). Our work is motivated by the challenge of
scalably integrating an arbitrarily-shaped, low-damping magnetic system with
planar superconducting circuits, thus enabling a host of quantum magnonic
circuit designs that were previously inaccessible. For example, by leveraging
the inherent properties of magnons, one can enable nonreciprocal
magnon-mediated quantum devices that use magnon propagation rather than
electrical current. We take advantage of the properties of V[TCNE]$_x$, which
has ultra-low intrinsic damping, can be grown at low processing temperatures on
arbitrary substrates, and can be patterned via electron beam lithography. We
demonstrate the scalable, lithographically integrated fabrication of hybrid
quantum magnonic devices consisting of a thin-film superconducting resonator
coupled to a low-damping, thin-film V[TCNE]$_x$ microstructure. Our devices
operate in the strong coupling regime, with a cooperativity as high as 1181(44)
at T$\sim$0.4 K, suitable for scalable quantum circuit integration. This work
paves the way for the exploration of high-cooperativity hybrid magnonic quantum
devices in which magnonic circuits can be designed and fabricated as easily as
electrical wires.",2212.04423v1
2016-07-08,Control of magnon-photon coupling strength in a planar resonator/YIG thin film configuration,"A systematic study of the coupling at room temperature between ferromagnetic
resonance (FMR) and a planar resonator is presented. The chosen magnetic
material is a ferrimagnetic insulator (Yttrium Iron Garnet: YIG) which is
positioned on top of a stop band (notch) filter based on a stub line
capacitively coupled to a 50 $\Omega$ microstrip line resonating at 4.731 GHz.
Control of the magnon-photon coupling strength is discussed in terms of the
microwave excitation configuration and the YIG thickness from 0.2 to 41 $\mu$m.
From the latter dependence, we extract a single spin-photon coupling of
g$_{0}$/2$\pi$=162$\pm$6 mHz and a maximum of an effective coupling of 290 MHz.",1607.02358v3
2020-12-04,Nutation in antiferromagnetic resonance,"The effect of inertial spin dynamics is compared between ferromagnetic,
antiferromagnetic and ferrimagnetic systems. The linear response to an
oscillating external magnetic field is calculated within the framework of the
inertial Landau--Lifshitz--Gilbert equation using analytical theory and
computer simulations. Precession and nutation resonance peaks are identified,
and it is demonstrated that the precession frequencies are reduced by the spin
inertia, while the lifetime of the excitations is enhanced. The interplay
between precession and nutation is found to be the most prominent in
antiferromagnets, where the timescale of the exchange-driven sublattice
dynamics is comparable to inertial relaxation times. Consequently,
antiferromagnetic resonance techniques should be better suited for the search
for intrinsical inertial spin dynamics on ultrafast timescales than
ferromagnetic resonance.",2012.02790v3
2023-08-22,"Structural, morphological, and magnetic characterizations of (Fe0.25Mn0.75)2O3 nanocrystals: a comprehensive stoichiometric determination","Iron manganese trioxide (Fe0.25Mn0.75)2O3 nanocrystals were synthesized by
the sol-gel method. The 80 K Mossbauer spectrum was well-fitted using two
doublets representing the 8b and 24d crystallographic sites of the
(FexMn1-x)2O3 phase and two weak extra sextets which were attributed to
crystalline and amorphous hematite. Our findings showed formation of a bixbyite
primary phase. The Raman spectrum exhibits six Raman active modes, typical of
(Fe,Mn)2O3, and two extra Raman modes associated with the secondary hematite
phase. X-ray photoelectron spectroscopy analysis confirmed the presence of
oxygen vacancy onto the (FexMn1-x)2O3 particle surface, with varying oxidation
states. X-band magnetic resonance data revealed a single broad resonance line
in the whole temperature range (3.8 K - 300 K). The temperature dependence of
both resonance field and resonance linewidth shows a remarkable change in the
range of 40 - 50 K, herein credited to surface spin glass behavior. The model
picture used assumes (FexMn1-x)2O3 nanoparticles with a core-shell structure.
Results indicate that below about 50 K the spin system of shell reveals a
paramagnetic to spin glass-like transition upon cooling, with a critical
temperature estimated at 43 K. In the higher temperature range, the
superparamagnetic hematite (secondary) phase contributes remarkably to the
temperature dependence of the resonance linewidth. Zero-field-cooled (ZFC) and
fieldcooled (FC) data show strong irreversibility and a peak in the ZFC curve
at 33 K, attributed to a paramagnetic-ferrimagnetic transition of the main
phase. Hysteresis curve at 5 K shows a low coercive field of 4 kOe, with the
magnetization not reaching saturation at 70 kOe, suggesting the occurrence of a
ferrimagnetic core with a magnetic disorder at surface, characteristic of
core-shell spin-glass-like behavior.",2308.11128v2
2012-07-25,High cooperativity in coupled microwave resonator ferrimagnetic insulator hybrids,"We report the observation of strong coupling between the exchange-coupled
spins in gallium-doped yttrium iron garnet and a superconducting coplanar
microwave resonator made from Nb. The measured coupling rate of 450 MHz is
proportional to the square-root of the number of exchange-coupled spins and
well exceeds the loss rate of 50 MHz of the spin system. This demonstrates that
exchange coupled systems are suitable for cavity quantum electrodynamics
experiments, while allowing high integration densities due to their
extraordinary high spin densities. Our results furthermore show, that
experiments with multiple exchange-coupled spin systems interacting via a
single resonator are within reach.",1207.6039v2
2014-03-04,Off-Resonant Manipulation of Spins in Diamond via Precessing Magnetization of a Proximal Ferromagnet,"We report the manipulation of nitrogen vacancy (NV) spins in diamond when
nearby ferrimagnetic insulator, yttrium iron garnet, is driven into precession.
The change in NV spin polarization, as measured by changes in
photoluminescence, is comparable in magnitude to that from conventional
optically detected magnetic resonance, but relies on a distinct mechanism as it
occurs at a microwave frequency far removed from the magnetic resonance
frequency of the NV spin. This observation presents a new approach to
transferring ferromagnetic spin information into a paramagnet and then
transducing the response into a robust optical signal. It also opens new
avenues for studying ferromagnetism and spin transport at the nanoscale.",1403.0656v1
2019-01-15,"SiC-YiG X band quantum sensor for sensitive surface paramagnetic resonance applied to chemistry, biology, physics","Here I present the SiC-YiG Quantum Sensor, allowing electron paramagnetic
resonance (EPR) studies of monolayer or few nanometers thick chemical,
biological or physical samples located on the sensor surface. It contains two
parts, a 4H-SiC substrate with many paramagnetic silicon vacancies (V2) located
below its surface, and YIG ferrimagnetic nanostripes. Spins sensing properties
are based on optically detected double electron-electron spin resonance under
the strong magnetic field gradient of nanostripes. Here I describe fabrication,
magnetic, optical and spins sensing properties of this sensor. I show that the
target spins sensitivity is at least five orders of magnitude larger than the
one of standard X band EPR spectrometer, for which it constitutes, combined
with a fiber bundle, a powerful upgrade for sensitive surface EPR. This sensor
can determine the target spins planes EPR spectrum, their positions with a
nanoscale precision of +/- 1 nm, and their 2D concentration down to
1/(20nm.20nm).",1901.05073v1
2021-03-31,Room temperature antiferromagnetic resonance and inverse spin-Hall voltage in canted antiferromagnets,"We study theoretically and experimentally the spin pumping signals induced by
the resonance of canted antiferromagnets with Dzyaloshinskii-Moriya interaction
and demonstrate that they can generate easily observable inverse spin-Hall
voltages. Using a bilayer of hematite/heavy metal as a model system, we measure
at room temperature the antiferromagnetic resonance and an associated inverse
spin-Hall voltage, as large as in collinear antiferromagnets. As expected for
coherent spin-pumping, we observe that the sign of the inverse spin-Hall
voltage provides direct information about the mode handedness as deduced by
comparing hematite, chromium oxide and the ferrimagnet Yttrium-Iron Garnet. Our
results open new means to generate and detect spin-currents at terahertz
frequencies by functionalizing antiferromagnets with low damping and canted
moments.",2103.16872v1
1998-10-09,Magnetic Properties of Quantum Ferrimagnetic Spin Chains,"Magnetic susceptibilities of spin-$(S,s)$ ferrimagnetic Heisenberg chains are
numerically investigated. It is argued how the ferromagnetic and
antiferromagnetic features of quantum ferrimagnets are exhibited as functions
of $(S,s)$. Spin-$(S,s)$ ferrimagnetic chains behave like combinations of
spin-$(S-s)$ ferromagnetic and spin-$(2s)$ antiferromagnetic chains provided
$S=2s$.",9810112v1
2023-08-07,$\textit{In situ}$ electric-field control of ferromagnetic resonance in the low-loss organic-based ferrimagnet V[TCNE]$_{x\sim 2}$,"We demonstrate indirect electric-field control of ferromagnetic resonance
(FMR) in devices that integrate the low-loss, molecule-based, room-temperature
ferrimagnet vanadium tetracyanoethylene (V[TCNE]$_{x \sim 2}$) mechanically
coupled to PMN-PT piezoelectric transducers. Upon straining the V[TCNE]$_x$
films, the FMR frequency is tuned by more than 6 times the resonant linewidth
with no change in Gilbert damping for samples with $\alpha = 6.5 \times
10^{-5}$. We show this tuning effect is due to a strain-dependent magnetic
anisotropy in the films and find the magnetoelastic coefficient $|\lambda_S|
\sim (1 - 4.4)$ ppm, backed by theoretical predictions from DFT calculations
and magnetoelastic theory. Noting the rapidly expanding application space for
strain-tuned FMR, we define a new metric for magnetostrictive materials,
$\textit{magnetostrictive agility}$, given by the ratio of the magnetoelastic
coefficient to the FMR linewidth. This agility allows for a direct comparison
between magnetostrictive materials in terms of their comparative efficacy for
magnetoelectric applications requiring ultra-low loss magnetic resonance
modulated by strain. With this metric, we show V[TCNE]$_x$ is competitive with
other magnetostrictive materials including YIG and Terfenol-D. This combination
of ultra-narrow linewidth and magnetostriction in a system that can be directly
integrated into functional devices without requiring heterogeneous integration
in a thin-film geometry promises unprecedented functionality for electric-field
tuned microwave devices ranging from low-power, compact filters and circulators
to emerging applications in quantum information science and technology.",2308.03353v1
2011-01-12,Gigantic terahertz magnetochromism via electromagnons in hexaferrite magnet Ba$_2$Mg$_2$Fe$_{12}$O$_{22}$,"Effects of temperature (6--225 K) and magnetic field (0--7 T) on the
low-energy (1.2--5 meV) electrodynamics of the electromagnon, the magnetic
resonance driven by the light electric field, have been investigated for a
hexaferrite magnet Ba$_2$Mg$_2$Fe$_{12}$O$_{22}$ by using terahertz time-domain
spectroscopy. We find the gigantic terahertz magnetochromism via
electromagnons; the magnetochromic change, as defined by the difference of the
absorption intensity with and without magnetic field, exceeds 500% even at 0.6
T. The results arise from the fact that the spectral intensity of the
electromagnon critically depends on the magnetic structure. With changing the
conical spin structures in terms of the conical angle $\theta$ from the proper
screw ($\theta=0^\circ$) to the ferrimagnetic ($\theta=90^\circ$) through the
conical spin-ordered phases ($0^\circ<\theta<90^\circ$) by external magnetic
fields, we identify the maximal magnetochromism around $\theta\approx45^\circ$.
On the contrary, there is no remarkable signature of the electromagnon in the
proper screw and spin-collinear (ferrimagnetic) phases, clearly indicating the
important role of the conical spin order to produce the
magnetically-controllable electromagnons. The possible origin of this
electromagnon is argued in terms of the exchange-striction mechanism.",1101.2303v1
2020-07-17,Coherent coupling between multiple ferrimagnetic spheres and a microwave cavity in the quantum-limit,"The spin resonance of electrons can be coupled to a microwave cavity mode to
obtain a photon-magnon hybrid system. These quantum systems are widely studied
for both fundamental physics and technological quantum applications. In this
article, the behavior of a large number of ferrimagnetic spheres coupled to a
single cavity is put under test. We use second-quantization modeling of
harmonic oscillators to theoretically describe our experimental setup and
understand the influence of several parameters. The magnon-polariton dispersion
relation is used to characterize the system, with a particular focus on the
vacuum Rabi mode splitting due to multiple spheres. We combine the results
obtained with simple hybrid systems to analyze the behavior of a more complex
one, and show that it can be devised in such a way to minimize the degrees of
freedom needed to completely describe it. By studying single-sphere coupling
two possible size-effects related to the sample diameter have been identified,
while multiple-spheres configurations reveal how to upscale the system. This
characterization is useful for the implementation of an
axion-to-electromagnetic field transducer in a ferromagnetic haloscope for dark
matter searches. Our dedicated setup, consisting in ten 2 mm-diameter YIG
spheres coupled to a copper microwave cavity, is used for this aim and studied
at mK temperatures. Moreover, we show that novel applications of
optimally-controlled hybrid systems can be foreseen for setups embedding a
large number of samples.",2007.08908v3
2020-05-29,Direction-sensitive magnetophotonic surface crystal,"Nanometer-thin rare-earth-transition metal (RE-TM) alloys with precisely
controlled compositions and out-of-plane magnetic anisotropy are currently in
the focus for ultrafast magnetophotonic applications. However, achieving
lateral nanoscale dimensions, crucial for potential device downscaling, while
maintaining designable optomagnetic functionality and out-of-plane magnetic
anisotropy is extremely challenging. Here we integrate nanosized
Tb$_{18}$Co$_{82}$ ferrimagnetic alloys, having strong out-of-plane magnetic
anisotropy, within a gold plasmonic nanoantenna array to design
micrometer-scale a magnetophotonic crystal that exhibit abrupt and narrow
magneto-optical spectral features that are both magnetic field and light
incidence direction controlled. The narrow Fano-type resonance arises through
the interference of the individual nanoantenna's surface plasmons and a
Rayleigh anomaly of the whole nanoantenna array, in both optical and
magneto-optical spectra, which we demonstrate and explain using Maxwell-theory
simulations. This robust magnetophotonic crystal opens the way for conceptually
new high-resolution light incidence direction sensors, as well as for building
blocks for plasmon-assisted all-optical magnetization switching in
ferrimagnetic RE-TM alloys.",2005.14478v3
2021-12-11,Optical excitation of electromagnons in hexaferrite,"Understanding ultrafast magnetization dynamics on the microscopic level is of
strong current interest due to the potential for applications in information
storage. In recent years, the spin-lattice coupling has been recognized to be
essential for ultrafast magnetization dynamics. Magnetoelectric multiferroics
of type II possess intrinsic correlations among magnetic sublattices and
electric polarization (P) through spin-lattice coupling, enabling fundamentally
coupled dynamics between spins and lattice. Here we report on ultrafast
magnetization dynamics in a room-temperature multiferroic hexaferrite
possessing ferrimagnetic and antiferromagnetic sublattices, revealed by
time-resolved resonant x-ray diffraction. A femtosecond above-bandgap
excitation triggers a coherent magnon in which the two magnetic sublattices
entangle and give rise to a transient modulation of P. A novel microscopic
mechanism for triggering the coherent magnon in this ferrimagnetic insulator
based on the spin-lattice coupling is proposed. Our finding opens up a novel
but general pathway for ultrafast control of magnetism.",2112.05961v1
2023-10-17,Low-energy electronic interactions in ferrimagnetic Sr2CrReO6 thin films,"We reveal in this study the fundamental low-energy landscape in the
ferrimagnetic Sr2CrReO6 double perovskite and describe the underlying
mechanisms responsible for the three low-energy excitations below 1.4 eV. Based
on resonant inelastic x-ray scattering and magnetic dynamics calculations, and
experiments collected from both Sr2CrReO6 powders and epitaxially strained thin
films, we reveal a strong competition between spin-orbit coupling, Hund's
coupling, and the strain-induced tetragonal crystal field. We also demonstrate
that a spin-flip process is at the origin of the lowest excitation at 200 meV,
and we bring insights into the predicted presence of orbital ordering in this
material. We study the nature of the magnons through a combination of ab initio
and spin-wave theory calculations, and show that two nondegenerate magnon bands
exist and are dominated either by rhenium or chromium spins. The rhenium band
is found to be flat at about 200 meV ($\pm$25 meV) through X-L-W-U
high-symmetry points and is dispersive toward $\Gamma$",2310.11585v1
2024-01-09,Microwave magnetic excitations in U-type hexaferrite Sr$_4$CoZnFe$_{36}$O$_{60}$ ceramics,"Microwave (MW) spectra of ferrimagnetic U-hexaferrite
Sr$_4$CoZnFe$_{36}$O$_{60}$ ceramics were studied using several experimental
techniques from 100 MHz to 50 GHz at temperatures between 10 and 390 K. They
revealed 9 excitations, which exhibit remarkable temperature dependences near
the magnetic phase transitions at 145 K and 305 K. Some of them also change
under the application of a weak bias magnetic field at room temperature. Three
lowest-frequency modes seen between 200 MHz and 3 GHz were assigned to the
dynamics of the magnetic domains. The mode attributed to the natural
ferromagnetic resonance exhibits a dramatic critical slowing-down from 25 GHz
at 390 K to 5 GHz near the 305 K phase transition, and again a hardening to ~11
GHz on further cooling. The higher-frequency excitations are most likely spin
wave (magnon) modes arising from the complex ferrimagnetic structure of
Sr$_4$CoZnFe$_{36}$O$_{60}$. The high sensitivity of the MW spectra to the weak
magnetic bias field $H$ < 700 Oe at room temperature is shown to be caused by
the transformation of the polydomain magnetic structure in randomly oriented
ceramic grains to a monodomain one. The MW response measured above 2 GHz using
coplanar and microstrip lines with different electromagnetic field distribution
and sample coupling revealed the same excitations with similar temperature and
bias field dependences. It confirms the reliability of the results and proves
the effectiveness of the used MW techniques.",2401.04678v1
2024-02-06,Magnon mediated spin pumping by coupled ferrimagnetic garnets heterostructure,"Spin pumping has significant implications for spintronics, providing a
mechanism to manipulate and transport spins for information processing.
Understanding and harnessing spin currents through spin pumping is critical for
the development of efficient spintronic devices. The use of a magnetic
insulator with low damping, enhances the signal-to-noise ratio in crucial
experiments such as spin-torque ferromagnetic resonance (FMR) and spin pumping.
A magnetic insulator coupled with a heavy metal or quantum material offers a
more straight forward model system, especially when investigating spin-charge
interconversion processes to greater accuracy. This simplicity arises from the
absence of unwanted effects caused by conduction electrons unlike in
ferromagnetic metals. Here, we investigate the spin pumping in coupled
ferrimagnetic (FiM) Y3Fe5O12 (YIG)/Tm3Fe5O12 (TmIG) bilayers combined with
heavy-metal (Pt) using the inverse spin Hall effect (ISHE). It is observed that
magnon transmission occurs at both of the FiMs FMR positions. The enhancement
of spin pumping voltage (Vsp) in the FiM garnet heterostructures is attributed
to the strong interfacial exchange coupling between FiMs. The modulation of Vsp
is achieved by tuning the bilayer structure. Further, the spin mixing
conductance for these coupled systems is found to be 10^18 m^-2. Our findings
describe a novel coupled FiM system for the investigation of magnon coupling
providing new prospects for magnonic devices.",2402.03734v1
1999-01-08,Quantum Ferrimagnets,"We study quantum ferrimagnets in one, two, and three dimensions by using a
variety of methods and approximations. These include: (i) a treatment based on
the spin coherent state path-integral formulation of quantum ferrimagnets by
taking into account the leading order quantum and thermal fluctuations (ii) a
field-theoretical (non-linear $\sigma$-model type) formulation of the special
case of one-dimensional quantum ferrimagnets at zero temperature (iii) an
effective description in terms of dimers and quantum rotors, and (iv) a quantum
renormalization group study of ferrimagnetic Heisenberg chains. Some of the
formalism discussed here can be used for a unified treatment of both
ferromagnets and antiferromagnets in the semiclassical limit. We show that the
low (high) energy effective Hamiltonian of a (S_1, S_2) Heisenberg ferrimagnet
is a ferromagnetic (antiferromagnetic) Heisenberg model. We also study the
phase diagram of quantum ferrimagnets in the presence of an external magnetic
field h ($h_{c1} < h < h_{c2}$) and show that the low- and the high-field
phases correspond respectively to the classical N\'eel and the fully polarized
ferromagnetic states. We also calculate the transition temperature for the
Berezinskii-Kosterlitz-Thouless phase transition in the special case of
two-dimensional quantum ferrimagnets.",9901063v2
2012-07-29,Ferrimagnetism of the Heisenberg Models on the Quasi-One-Dimensional Kagome Strip Lattices,"We study the ground-state properties of the S=1/2 Heisenberg models on the
quasi-onedimensional kagome strip lattices by the exact diagonalization and
density matrix renormalization group methods. The models with two different
strip widths share the same lattice structure in their inner part with the
spatially anisotropic two-dimensional kagome lattice. When there is no magnetic
frustration, the well-known Lieb-Mattis ferrimagnetic state is realized in both
models. When the strength of magnetic frustration is increased, on the other
hand, the Lieb-Mattis-type ferrimagnetism is collapsed. We find that there
exists a non-Lieb-Mattis ferrimagnetic state between the Lieb-Mattis
ferrimagnetic state and the nonmagnetic ground state. The local magnetization
clearly shows an incommensurate modulation with long-distance periodicity in
the non-Lieb-Mattis ferrimagnetic state. The intermediate non-Lieb-Mattis
ferrimagnetic state occurs irrespective of strip width, which suggests that the
intermediate phase of the two-dimensional kagome lattice is also the
non-Lieb-Mattis-type ferrimagnetism.",1207.6771v1
2017-10-21,Correlation between Compensation Temperatures of Magnetization and Angular Momentum in GdFeCo Ferrimagnets,"Determining the angular momentum compensation temperature of ferrimagnets is
an important step towards ferrimagnetic spintronics, but is not generally easy
to achieve it experimentally. We propose a way to estimate the angular momentum
compensation temperature of ferrimagnets. We find a linear relation between the
compensation temperatures of the magnetization and angular momentum in GdFeCo
ferrimagnetic materials, which is proved by theoretically as well as
experimentally. The linearity comes from the power-law criticality and is
governed by the Curie temperature and the Land\'e g factors of the elements
composing the ferrimagnets. Therefore, measuring the magnetization compensation
temperature and the Curie temperature, which are easily assessable
experimentally, enables to estimate the angular momentum compensation
temperature of ferrimagnets. Our study provides efficient avenues into an
exciting world of ferrimagnetic spintronics.",1710.07779v1
2008-02-22,Microwave spectral analysis by means of non-resonant parametric recovery of spin-wave signals in a thin magnetic film,"We report on the storage and non-resonant parametric recovery of microwave
signals carried by a dipolar surface spin-wave pulse in a thin ferrimagnetic
film. The information about the intensity of the spectral components of the
signal within a narrow frequency band is saved due to the excitation of a
dipolar-exchange standing spin-wave mode across the film thickness and is
afterwards restored by means of parametric amplification of this mode. The
intensity of the restored signal measured for varying shifts between the signal
carrier frequency and half of the pumping frequency, which is equal to the
frequency of the standing mode, reveals information about the entire frequency
spectrum of the input microwave signal.",0802.3302v1
2016-01-04,Unidirectional terahertz light absorption in the pyroelectric ferrimagnet CaBaCo4O7,"Spin excitations were studied by absorption spectroscopy in CaBaCo4O7 which
is a type-I multiferroic compound with the largest magnetic-order induced
ferroelectric polarization ({\Delta}P=17mC/m2) reported, so far. We observed
two optical magnon branches: a solely electric dipole allowed one and a mixed
magnetoelectric resonance. The entangled magnetization and polarization
dynamics of the magnetoelectric resonance gives rise to unidirectional light
absorption, i.e. that magnon mode absorbs the electromagnetic radiation for one
propagation direction but not for the opposite direction. Our systematic study
of the magnetic field and temperature dependence of magnon modes provides
information about the energies and symmetries of spin excitations, which is
required to develop a microscopic spin model of CaBaCo4O7.",1601.00444v1
2014-03-21,Colloidal Assemblies of Oriented Maghemite Nanocrystals and their NMR Relaxometric Properties,"Elevated-temperature polyol-based colloidal-chemistry approach allows for the
development of size-tunable (50 and 86 nm) assemblies of maghemite iso-oriented
nanocrystals, with enhanced magnetization. 1H-Nuclear Magnetic Resonance (NMR)
relaxometric experiments show that the ferrimagnetic cluster-like colloidal
entities exhibit a remarkable enhancement (4 to 5 times) in the transverse
relaxivity, if compared to that of the superparamagnetic contrast agent
Endorem, over an extended frequency range (1-60 MHz). The marked increase of
the transverse relaxivity r2 at a clinical magnetic field strength (1.41 T),
which is 405.1 and 508.3 mM-1 s-1 for small and large assemblies respectively,
allows to relate the observed response to the raised intra-aggregate magnetic
material volume fraction. Furthermore, cell tests with murine fibroblast
culture medium confirmed the cell viability in presence of the clusters. We
discuss the NMR dispersion profiles on the basis of relaxivity models to
highlight the magneto-structural characteristics of the materials for improved
T2-weighted magnetic resonance images.",1403.5450v1
2017-04-28,Thermal Control of the Magnon-Photon Coupling in a Notch Filter coupled to a Yttrium-Iron-Garnet/Platinum System,"We report thermal control of mode hybridization between the ferromagnetic
resonance (FMR) and a planar resonator (notch filter) working at 4.74 GHz. The
chosen magnetic material is a ferrimagnetic insulator (Yttrium Iron Garnet:
YIG) covered by 6 nm of platinum (Pt). A current induced heating method has
been used in order to enhance the temperature of the YIG/Pt system. The device
permits us to control the transmission spectra and the magnon-photon coupling
strength at room temperature. These experimental findings reveal potentially
applicable tunable microwave filtering function.",1704.08896v3
2018-08-13,Gilbert damping phenomenology for two-sublattice magnets,"We present a systematic phenomenological description of Gilbert damping in
two-sublattice magnets. Our theory covers the full range of materials from
ferro- via ferri- to antiferromagnets. Following a Rayleigh dissipation
functional approach within a Lagrangian classical field formulation, the theory
captures intra- as well as cross-sublattice terms in the Gilbert damping,
parameterized by a 2$\times$2 matrix. When spin-pumping into an adjacent
conductor causes dissipation, we obtain the corresponding Gilbert damping
matrix in terms of the interfacial spin-mixing conductances. Our model
reproduces the experimentally observed enhancement of the ferromagnetic
resonance linewidth in a ferrimagnet close to its compensation temperature
without requiring an increased Gilbert parameter. It also predicts new
contributions to damping in an antiferromagnet and suggests the resonance
linewidths as a direct probe of the sublattice asymmetry, which may stem from
boundary or bulk.",1808.04385v2
2021-11-30,First and second order magnetic anisotropy and damping of europium iron garnet under high strain,"Understanding and tailoring static and dynamic properties of magnetic
insulator thin films is important for spintronic device applications. Here, we
grow atomically flat epitaxial europium iron garnet (EuIG) thin films by pulsed
laser deposition on (111)-oriented garnet substrates with a range of lattice
parameters. By controlling the lattice mismatch between EuIG and the
substrates, we tune the strain in EuIG films from compressive to tensile
regime, which is characterized by X-ray diffraction. Using ferromagnetic
resonance, we find that in addition to the first-order perpendicular magnetic
anisotropy which depends linearly on the strain, there is a significant
second-order one that has a quadratic strain dependence. Inhomogeneous
linewidth of the ferromagnetic resonance increases notably with increasing
strain, while the Gilbert damping parameter remains nearly constant (~
2x10^-2). These results provide valuable insight into the spin dynamics in
ferrimagnetic insulators and useful guidance for material synthesis and
engineering of next-generation spintronics applications.",2111.15142v1
2022-05-13,Fast scanning nitrogen-vacancy magnetometry by spectrum demodulation,"We demonstrate a spectrum demodulation technique for greatly speeding up the
data acquisition rate in scanning nitrogen-vacancy center magnetometry. Our
method relies on a periodic excitation of the electron spin resonance by fast,
wide-band frequency sweeps combined with a phase-locked detection of the
photo-luminescence signal. The method can be extended by a frequency feedback
to realize real-time tracking of the spin resonance. Fast scanning magnetometry
is especially useful for samples where the signal dynamic range is large, of
order millitesla, like for ferro- or ferrimagnets. We demonstrate our method by
mapping stray fields above the model antiferromagnet $\alpha$-Fe$_2$O$_3$
(hematite) at pixel rates of up to 100\,Hz and an image resolution exceeding
one megapixel.",2205.06579v1
2024-03-25,Detection of spin pumping free of rectification and thermal artefacts in molecular-based ferromagnetic insulator V[TCNE]x~2,"The molecular-based ferrimagnetic insulator V(TCNE)x has gained recent
interest for efficient spin-wave excitation due to its low Gilbert damping
ratio a=4E-5, and narrow ferromagnetic resonance linewidth f=1Oe. Here we
report a clean spin pumping signal detected on V(TCNE)x/metal bilayer
structures, free from spin rectification or thermal artifacts. On-chip coupling
of microwave power is achieved via a coplanar waveguide to measure the in-plane
angle-dependence of the inverse spin-Hall effect under ferromagnetic resonance
conditions with respect to a constant external magnetic field. A signature of
pure spin current from V(TCNE)x is observed in both platinum and permalloy
metal layers, demonstrating the utility of V(TCNE)x for magnon spintronics
studies in molecule/solid-state heterostructures.",2403.16429v2
2011-02-16,Collapse of Ferrimagnetism in Two-Dimensional Heisenberg Antiferromagnet due to Frustration,"We study ferrimagnetism in the ground state of the antiferromagnetic
Heisenberg model on the spatially anisotropic kagome lattice, in which
ferrimagnetism of the conventional Lieb-Mattis type appears in the region of
weak frustration whereas the ground state is nonmagnetic in the isotropic case.
Numerical diagonalizations of small finite-size clusters are carried out to
examine the spontaneous magnetization. We find that the spontaneous
magnetization changes continuously in the intermediate region between
conventional ferrimagnetism and the nonmagnetic phase. Local magnetization of
the intermediate state shows strong dependence on the site position, which
suggests non-Lieb-Mattis ferrimagnetism.",1102.3244v1
2012-11-01,Spin Seebeck effect in antiferromagnets and compensated ferrimagnets,"We theoretically investigate the spin Seebeck effect (SSE) in
antiferromagnets and ferrimagnets, and show that the SSE vanishes in
antiferromagnets but survives in ferrimagnets even at the magnetization
compensation point despite the absence of its saturation magnetization. The
non-vanishing SSE in ferrimagnets stems from two non-degenerate magnons. We
demonstrate that the magnitude of the SSE in ferrimagnets is unchanged across
the magnetization compensation point.",1211.0123v1
2015-02-04,Instability of a ferrimagnetic state of a frustrated S=1/2 Heisenberg antiferromagnet in two dimensions,"To clarify the instability of the ferrimagnetism which is the fundamental
magnetism of ferrite, numerical-diagonalization study is carried out for the
two-dimensional S=1/2 Heisenberg antiferromagnet with frustration. We find that
the ferrimagnetic ground state has the spontaneous magnetization in small
frustration; due to a frustrating interaction above a specific strength, the
spontaneous magnetization discontinuously vanishes so that the ferrimagnetic
state appears only under some magnetic fields. We also find that, when the
interaction is increased further, the ferrimagnetism disappears even under
magnetic field.",1502.01071v1
2019-10-31,Time-resolving magnetic scattering on rare-earth ferrimagnets with a bright soft-X-ray high-harmonic source,"We demonstrate the first time-resolved X-ray resonant magnetic scattering
(tr-XRMS) experiment at the N edge of Tb at 155 eV performed using a tabletop
high-brightness high-harmonic generation (HHG) source. In contrast to static
X-ray imaging applications, such optical-pump X-ray-probe studies pose a
different set of challenges for the ultrafast driver laser because a high
photon flux of X-rays resonant with the N edge must be attained at a low
repetition rate to avoid thermal damage of the sample. This laboratory-scale
X-ray magnetic diffractometer is enabled by directly driving HHG in helium with
terawatt-level 1 um laser fields, which are obtained through pulse compression
after a high-energy kHz-repetition-rate Yb:CaF2 amplifier. The high peak power
of the driving fields allows us to reach the fully phase-matching conditions in
helium, which yields the highest photon flux (>2x10^9 photons/s/1% bandwidth)
in the 100-220 eV spectral range, to the best of our knowledge. Our
proof-of-concept tr-XRMS measurements clearly resolve the spatio-temporal
evolution of magnetic domains in Co/Tb ferrimagnetic alloys with femtosecond
and nanometer resolution. In addition to the ultrafast demagnetization, we
observe magnetic domain expansion with a domain wall velocity similar to that
induced by spin transfer torque. The demonstrated method opens up new
opportunities for time-space-resolved magnetic scattering with elemental
specificity on various magnetic, orbital and electronic orderings in condensed
matter systems.",1910.14263v1
2020-09-29,Spin transfer torque in Mn$_3$Ga-based ferrimagnetic tunnel junctions from first principles,"We report on first-principles calculations of spin-transfer torque (STT) in
epitaxial magnetic tunnel junctions (MTJs) based on ferrimagnetic tetragonal
Mn$_3$Ga electrodes, both as analyzer in an Fe/MgO stack, and also in an
analogous stack with a second Mn$_3$Ga electrode (instead of Fe) as polarizer.
Solving the ballistic transport problem (NEGF + DFT) for the nonequilibrium
spin density in a scattering region extended to over 7.6 nm into the Mn$_3$Ga
electrode, we find long-range spatial oscillations of the STT decaying on a
length scale of a few tens of angstroms, both in the linear response regime and
for finite bias. The oscillatory behavior of the STT in Mn$_3$Ga is robust
against variations in the stack geometry and the applied bias voltage, which
may affect the phase and the amplitude of the spatial oscillation, but the wave
number is only responsive to variations in the longitudinal lattice constant of
Mn$_3$Ga (for fixed in-plane geometry) without being commensurate with the
lattice. Our interpretation of the long-range STT oscillations is based on the
bulk electronic structure of Mn$_3$Ga, taking also into account the
spin-filtering properties of the MgO barrier. Comparison to a fully
Mn$_3$Ga-based stack shows similar STT oscillations, but a significant
enhancement of both the TMR effect at the Fermi level and the STT at the
interface, due to resonant tunneling for the mirror-symmetric junction with
thinner barrier (three monoatomic layers). From the calculated energy
dependence of the spin-polarized transmissions at 0 V, we anticipate asymmetric
or symmetric TMR as a function of the applied bias voltage for the Fe-based and
the all-Mn$_3$Ga stacks, respectively, which also both exhibit a sign change
below 1 V. In the latter (symmetric) case we expect a TMR peak at zero, which
is larger for the thinner barriers because of a spin-polarized resonant
tunneling contribution.",2009.14095v2
2018-04-05,Stochastic ferrimagnetic Landau-Lifshitz-Bloch equation for finite magnetic structures,"Precise modeling of the magnetization dynamics of nanoparticles with finite
size effects at fast varying temperatures is a computationally challenging
task. Based on the Landau-Lifshitz-Bloch (LLB) equation we derive a coarse
grained model for disordered ferrimagnets, which is both fast and accurate.
First, we incorporate stochastic fluctuations to the existing ferrimagnetic LLB
equation. Further, we derive a thermodynamic expression for the temperature
dependent susceptibilities, which is essential to model finite size effects.
Together with the zero field equilibrium magnetization the susceptibilities are
used in the stochastic ferrimagnetic LLB to simulate a $5\times10$ nm$^2$
ferrimagnetic GdFeCo particle with 70 % FeCo and 30 % Gd under various external
applied fields and heat pulses. The obtained trajectories agree well with those
of an atomistic model, which solves the stochastic Landau-Lifshitz-Gilbert
equation for each atom. Additionally, we derive an expression for the
intergrain exchange field which couple the ferromagnetic sublattices of a
ferrimagnet. A comparison of the magnetization dynamics obtained from this
simpler model with those of the ferrimagnetic LLB equation shows a perfect
agreement.",1804.01724v1
2023-12-01,Compensated Ferrimagnets with Colossal Spin Splitting in Organic Compounds,"The study of the magnetic order has recently been invigorated by the
discovery of exotic collinear antiferromagnets with time-reversal symmetry
breaking. Examples include altermagnetism and compensated ferrimagnets, which
show spin splittings of the electronic band structures even at zero net
magnetization, leading to several unique transport phenomena, notably
spin-current generation. Altermagnets demonstrate anisotropic spin splitting,
such as $d$-wave, in momentum space, whereas compensated ferrimagnets exhibit
isotropic spin splitting. However, methods to realize compensated ferrimagnets
are limited. Here, we demonstrate a method to realize a fully compensated
ferrimagnet with isotropic spin splitting utilizing the dimer structures
inherent in organic compounds. Moreover, based on $ab$ $initio$ calculations,
we find that this ferrimagnet can be realized in the recently discovered
organic compound (EDO-TTF-I)$_2$ClO$_4$. Our findings provide an unprecedented
strategy for using the dimer degrees of freedom in organic compounds to realize
fully compensated ferrimagnets with colossal spin splitting.",2312.00367v2
2019-06-13,Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements,"Electrodynamic theory applied to the analysis of TEn0p mode resonances in
ferromagnetic spheres placed either in metallic cavities or in the free space
is compared with Walker-Fletcher's theory of so-called magnetostatic modes. The
influence of the diameter of the sample, its permittivity and the permittivity
of the surrounding media on the resonance frequencies of a few modes is
analyzed. It is shown that the dominant resonances are essentially related
either to negative values of the diagonal component of the permeability tensor
or, for clockwise circularly polarized magnetic fields, to negative effective
permeability. The electrodynamic theory is used to determine the saturation
magnetization (Ms) from measured TEn01 frequency differences. Measurements on
different samples confirmed that Ms can be determined using an electrodynamic
approach with uncertainties of the order of 2% regardless of sample sizes,
metal enclosures or static magnetic field values.",1906.05559v1
2019-01-10,Spin-wave Confinement and Coupling in Organic-Based Magnetic Nanostructures,"Vanadium tetracyanoethylene (V[TCNE]$_\text{x}$) is an organic-based
ferrimagnet that exhibits robust magnetic ordering (T$_\text{C}$ of over 600
K), high quality-factor (high-Q) microwave resonance (Q up to 3,500), and
compatibility with a wide variety of substrates and encapsulation technologies.
Here, we substantially expand the potential scope and impact of this emerging
material by demonstrating the ability to produce engineered nanostructures with
tailored magnetic anisotropy that serve as a platform for the exploration of
cavity magnonics, revealing strongly coupled quantum confined standing wave
modes that can be tuned into and out of resonance with an applied magnetic
field. Specifically, time-domain micromagnetic simulations of these
nanostructures faithfully reproduce the experimentally measured spectra,
including the quasi-uniform mode and higher-order spin-wave (magnon) modes.
Finally, when the two dominant magnon modes present in the spectra are brought
into resonance by varying the orientation of the in-plane magnetic field, we
observe anti-crossing behavior indicating strong coherent coupling between
these two magnon modes at room temperature. These results position
V[TCNE]$_\text{x}$ as a leading candidate for the development of coherent
magnonics, with potential applications ranging from microwave electronics to
quantum information.",1901.03286v2
2014-02-19,Theory of Ferrimagnetism in the Hubbard Model on Bipartite Lattices with Spectrum Symmetry,"In this paper we developed theory of the ferrimagnetism in the Hubbard model
on bipartite lattices with spectrum symmetry. We then study the defect-induced
ferrimagnetic orders in three models and explored the universal features.",1402.4634v1
2010-01-18,The missing atom as a source of carbon magnetism,"Atomic vacancies have a strong impact in the mechanical, electronic and
magnetic properties of graphene-like materials. By artificially generating
isolated vacancies on a graphite surface and measuring their local density of
states on the atomic scale, we have shown how single vacancies modify the
electronic properties of this graphene-like system. Our scanning tunneling
microscopy experiments, complemented by tight binding calculations, reveal the
presence of a sharp electronic resonance at the Fermi energy around each single
graphite vacancy, which can be associated with the formation of local magnetic
moments and implies a dramatic reduction of the charge carriers' mobility.
While vacancies in single layer graphene naturally lead to magnetic couplings
of arbitrary sign, our results show the possibility of inducing a macroscopic
ferrimagnetic state in multilayered graphene samples just by randomly removing
single C atoms.",1001.3081v2
2013-04-24,Observation of an inter-sublattice exchange magnon in CoCr$_2$O$_4$ and analysis of magnetic ordering,"We report on an investigation of optical properties of multiferroic
CoCr$_{2}$O$_{4}$ at terahertz frequencies in magnetic fields up to 30 T. Below
the ferrimagnetic transition (94 K), the terahertz response of
CoCr$_{2}$O$_{4}$ is dominated by a magnon mode, which shows a steep
magnetic-field dependence. We ascribe this mode to an exchange resonance
between two magnetic sublattices with different $g$-factors. In the framework
of a simple two-sublattice model (the sublattices are formed by Co$^{2+}$ and
Cr$^{3+}$ ions), we find the inter-sublattice coupling constant, $\lambda = -
(18 \pm 1)$ K, and trace the magnetization for each sublattice as a function of
field. We show that the Curie temperature of the Cr$^{3+}$ sublattice,
$\Theta_{2}$ = $(49 \pm 2)$ K, coincides with the temperature range, where
anomalies of the dielectric and magnetic properties of CoCr$_{2}$O$_{4}$ have
been reported in literature.",1304.6525v1
2014-11-10,Temperature evolution of the effective magnetic anisotropy in the MnCr$_2$O$_4$ spinel,"In this work we present a study of the low temperature magnetic phases of
polycrystalline MnCr$_2$O$_4$ spinel through dc magnetization and ferromagnetic
resonance spectroscopy (FMR). Through these experiments we determined the main
characteristic temperatures: T$_C$ $\sim$41 K and T$_H$ $\sim$18 K
corresponding, respectively, to the ferrimagnetic order and to the low
temperature helicoidal transitions. The temperature evolution of the system is
described by a phenomenological approach that considers the different terms
that contribute to the free energy density. Below the Curie temperature the FMR
spectra were modeled by a cubic magnetocrystalline anisotropy to the second
order, with $K_1$ and $K_2$ anisotropy constants that define the easy
magnetization axis along the <110> direction. At lower temperatures, the
formation of a helicoidal phase was considered by including uniaxial anisotropy
axis along the [1-10] propagation direction of the spiral arrange, with a $K_u$
anisotropy constant. The values obtained from the fittings at 5 K are
$K_1$=-2.3x10$^4$ erg/cm$^3$, $K^2$=6.4x10$^4$ erg/cm$^3$ and $K_u$=7.5x10$^4$
erg/cm$^3$.",1411.2461v1
2015-10-13,Optomagnonic whispering gallery microresonators,"Magnons in ferrimagnetic insulators such as yttrium iron garnet (YIG) have
recently emerged as promising candidates for coherent information processing in
microwave circuits. Here we demonstrate optical whispering gallery modes of a
YIG sphere interrogated by a silicon nitride photonic waveguide, with quality
factors approaching $10^6$ in the telecom c-band after surface treatments.
Moreover, in contrast to conventional Faraday setup, this implementation allows
input photon polarized colinearly to the magnetization to be scattered to a
sideband mode of orthogonal polarization. This Brillouin scattering process is
enhanced through triply resonant magnon, pump and signal photon modes - all of
whispering gallery nature - within an ""optomagnonic cavity"". Our results show
the potential use of magnons for mediating microwave-to-optical carrier
conversion.",1510.03545v1
2015-11-11,Cavity magnomechanics,"A dielectric body couples with electromagnetic fields through radiation
pressure and electrostrictive forces, which mediate phonon-photon coupling in
cavity optomechanics. In a magnetic medium, according to Korteweg-Helmholtz
formula, magnetostrictive forces should arise and lead to phonon-magnon
interaction. Here we report such a coupled phonon-magnon system based on
ferrimagnetic spheres, which we term as cavity magnomechanics, by analogy to
cavity optomechanics. Coherent phonon-magnon interactions, including
electromagnetically induced transparency and absorption, are demonstrated.
Excitingly, due to strong hybridization of magnon and microwave photon modes
and their high tunability, our platform exhibits new features including
parametric amplification of magnons and phonons, triply resonant
photon-magnon-phonon coupling and phonon lasing. Our work demonstrates the
fundamental principle of cavity magnomechanics and its application as a new
information transduction platform based on coherent coupling between photons,
phonons and magnons.",1511.03680v2
2016-09-15,Low-damping sub-10-nm thin films of lutetium iron garnet grown by molecular-beam epitaxy,"We analyze the structural and magnetic characteristics of (111)-oriented
lutetium iron garnet (Lu$_3$Fe$_5$O$_{12}$) films grown by molecular-beam
epitaxy, for films as thin as 2.8 nm. Thickness-dependent measurements of the
in- and out-of-plane ferromagnetic resonance allow us to quantify the effects
of two-magnon scattering, along with the surface anisotropy and the saturation
magnetization. We achieve effective damping coefficients of $11.1(9) \times
10^{-4}$ for 5.3 nm films and $32(3) \times 10^{-4}$ for 2.8 nm films, among
the lowest values reported to date for any insulating ferrimagnetic sample of
comparable thickness.",1609.04753v1
2016-09-23,Electromagnon resonance in a collinear spin state of a polar antiferromagnet Fe2Mo3O8,"Magnetic excitations are investigated for a hexagonal polar magnet Fe2Mo3O8
by terahertz spectroscopy. We observed magnon modes including an electric-field
active magnon, electromagnon, in the collinear antiferromagnetic phase with
spins parallel to the c axis. We unravel the nature of these excitations by
investigating the correlation between the evolution of the mode profile and the
magnetic transition from antiferromagnetic to ferrimagnetic order induced by
magnetic field or Zn-doping. We propose that the observed electromagnon mode
involves the collective precession of the spins with oscillating in-plane
electric polarization through the mechanism of the linear magnetoelectric
effect.",1609.07230v2
2017-02-20,Parametric pumping of spin waves by acoustic waves,"The linear and nonlinear interactions between spin waves (magnons) and
acoustic waves (phonons) in magnetostrictive materials provide an exciting
opportunity for realizing novel microwave signal processing devices and
spintronic circuits. Here we demonstrate the parametric pumping of spin waves
by acoustic waves, the possibility of which has long been theoretically
anticipated but never experimentally realized. Spin waves propagating in a thin
film of yttrium iron garnet (YIG), a magnetostrictive ferrimagnet with low spin
and acoustic wave damping, are pumped using an acoustic resonator driven at
frequencies near twice the spin wave frequency. The observation of a
counter-propagating idler wave and a distinct pump threshold that increases
quadratically with frequency non-degeneracy are evidence of a nonlinear
parametric pumping process consistent with classical theory. This demonstration
of acoustic parametric pumping lays the groundwork for developing new
spintronic and microwave signal processing devices based on amplification and
manipulation of spin waves by efficient, spatially localized acoustic
transducers.",1702.06038v1
2017-08-14,Terahertz frequency magnetoelectric effect in Ni doped CaBaCo$_4$O$_7$,"We present a study of terahertz frequency magnetoelectric effect in
ferrimagnetic pyroelectric CaBaCo$_4$O$_7$ and its Ni-doped variants. The
terahertz absorption spectrum of these materials consists of spin excitations
and low-frequency infrared-active phonons. We studied the
magnetic-field-induced changes in the terahertz refractive index and absorption
in magnetic fields up to 17 T. We find that the magnetic field modulates the
strength of infrared-active optical phonons near 1.2 and 1.6 THz. We use the
Lorentz model of the dielectric function to analyze the measured magnetic-field
dependence of the refractive index and absorption. We propose that most of the
magnetoelectric effect is contributed by the optical phonons near 1.6 THz and
higher-frequency resonances. Our experimental results can be used to construct
and validate more detailed theoretical descriptions of magnetoelectricity in
CaBaCo$_{4-x}$Ni$_x$O$_7$.",1708.04345v1
2014-06-02,Electronic and magnetic properties of (1 1 1)-oriented CoCr2O4 epitaxial thin film,"We report on the fabrication of high quality (1 1 1)-oriented ferrimagnetic
normal spinel CoCr2O4 epitaxial thin films on single crystal Al2O3 substrates.
The structural, electronic and magnetic properties were characterized by
in-situ reflection high energy electron diffraction, atomic force microscopy,
X-ray diffraction, X-ray photoemission spectroscopy, SQUID magnetometry and
element resolved resonant X-ray magnetic scattering. The comprehensive
characterization reveals that no disorder in the cation distribution or
multivalency issue is present in the samples. As a result, Kagome and
triangular layers are naturally formed via this specific growth approach. These
findings offer a pathway to fabricate two dimensional Kagome heterostructures
with novel quantum many-body phenomena by means of geometrical design.",1406.0523v1
2017-06-26,Perpendicular magnetic anisotropy in insulating ferrimagnetic gadolinium iron garnet thin films,"We present experimental control of the magnetic anisotropy in a gadolinium
iron garnet (GdIG) thin film from in-plane to perpendicular anisotropy by
simply changing the sample temperature. The magnetic hysteresis loops obtained
by SQUID magnetometry measurements unambiguously reveal a change of the
magnetically easy axis from out-of-plane to in-plane depending on the sample
temperature. Additionally, we confirm these findings by the use of temperature
dependent broadband ferromagnetic resonance spectroscopy (FMR). In order to
determine the effective magnetization, we utilize the intrinsic advantage of
FMR spectroscopy which allows to determine the magnetic anisotropy independent
of the paramagnetic substrate, while magnetometry determines the combined
magnetic moment from film and substrate. This enables us to quantitatively
evaluate the anisotropy and the smooth transition from in-plane to
perpendicular magnetic anisotropy. Furthermore, we derive the temperature
dependent $g$-factor and the Gilbert damping of the GdIG thin film.",1706.08488v1
2017-12-13,High-temperature terahertz optical diode effect without magnetic order in polar FeZnMo$_3$O$_8$,"We present a terahertz spectroscopic study of polar ferrimagnet
FeZnMo$_3$O$_8$. Our main finding is a giant high-temperature optical diode
effect, or nonreciprocal directional dichroism, where the transmitted light
intensity in one direction is over 100 times lower than intensity transmitted
in the opposite direction. The effect takes place in the paramagnetic phase
with no long-range magnetic order in the crystal, which contrasts sharply with
all existing reports of the terahertz optical diode effect in other
magnetoelectric materials, where the long-range magnetic ordering is a
necessary prerequisite. In \fzmo, the effect occurs resonantly with a strong
magnetic dipole active transition centered at 1.27 THz and assigned as electron
spin resonance between the eigenstates of the single-ion anisotropy
Hamiltonian. We propose that the optical diode effect in paramagnetic
FeZnMo$_3$O$_8$ is driven by signle-ion terms in magnetoelectric free energy.",1712.04972v2
2018-10-17,Conventional magnon BEC in YIG film,"The conventional magnon Bose-Einstein condensation (BEC of magnons with k =
0) is a coherent state of excited magnons described by a common wave function.
It was observed first in antiferromagnetic superfluid states of 3He. Here we
report on the discovery of a very similar magnon BEC in ferrimagnetic film at
room temperature. The experiments were performed in Yttrium Iron Garnet (YIG)
films at a magnetic field oriented perpendicular to the film. The high-density
quasiequilibrium state of excited magnon was formed by methods of pulse and/or
Continuous Waves (CW) magnetic resonance. We have observed a Long Lived
Induction Decay Signals (LLIDS), well known as a signature of spin
superfluidity. We demonstrate that the BEC state may maintain permanently by
continuous replenishment of magnons with a small radiofrequency (RF) field. Our
finding opens the way for development of potential supermagnonic applications
at an ambient conditions.",1810.08051v2
2020-02-23,"Generating lightwave-photon-and-magnon entanglement with a mechanical oscillator as a ""cold reservoir""","We present a scheme to implement a steady lightwave-photon-and-magnon
entanglement in a hybrid photon-magnon system by adiabatically eliminating the
auxiliary microwave cavity and effectively laser cooling a delocalized
Bogoliubov mode. The system consists of magnons, lightwave and microwave
photons, and phonons. The magnons are embodied by a collective motion of a
large number of spins in a macroscopic ferrimagnet. To achieve an entangling
interaction between magnons and lightwave photons, we drive optical cavity and
magnon at the red and blue sideband associated with the mechanical resonator.
In particular, optimizing the relative ratio of effect couplings, rather than
simply increasing their magnitudes, is essential for achieving strong
entanglement. Unlike typical dissipative entanglement schemes, our results
cannot be described by treating the effects of the entangling reservoir via a
Linblad master equation.",2002.10877v2
2020-12-29,Strongly modulated ultrafast demagnetization and magnetization precession dynamics in ferrimagnetic Gdx(CoFe)1-x alloys via 3d-4f intersublattice exchange coupling,"Manipulation of the intersublattice interaction strengh (JRE-TM) in rare
earth (RE)-transition metal (TM) alloys is a key issue to understand how
efficiently the laser-induced angular momentum transfers from 3d to 4f spins
and to have a better control of the ultrafast spin dynamics. In this work, the
relationships between laser-induced demagnetization process and the
intersublattice 3d-4f interaction for the GdCoFe alloys were systematically
studied. The ultrafast two-stage demagnetization process could change into a
one-stage mode as the angular momentum transferring channel between 3d and 4f
spins is switched off, which could be modulated by JRE-TM. Furthermore, both
the effective g-factor and damping constant deduced by the subsequently
laser-induced magnetization precession process diverge at the angular momentum
compensation point based on the ferromagnetic resonance method with the LLG
equations. The results provide an alternative way to efficiently manipulate the
ultrafast demagnetization time for practical applications.",2012.14620v1
2019-02-08,Magnetic Multipoles in a Ruthenate Ca3Ru2O7,"Compulsory Dirac multipoles in the bilayer perovskite Ca3Ru2O7 are absent in
published analyses of experimental data. In a first step at correcting
knowledge of the magnetic structure, we have analysed existing Bragg
diffraction patterns gathered on samples held well below the N\'eel temperature
at which A-type antiferromagnetic order of axial dipoles spontaneously
develops. Patterns were gathered with neutrons, and linearly polarized x-rays
tuned in energy to a ruthenium atomic resonance. Neutron diffraction data
contains solid evidence of Dirac dipoles (anapoles or toroidal moments). No
such conclusion is reached with existing x-ray diffraction data, which instead
is ambiguous on the question. To address this shortcoming by future
experiments, we calculated additional diffraction patterns. Chiral order of
Dirac multipoles is allowed by magnetic space-group PCna21, and it can be
exposed in Bragg diffraction using circularly polarized x-rays. Likewise, a
similar experiment can expose a chiral order of axial dipoles. A magnetic field
applied parallel to the b-axis creates a ferrimagnetic structure in which bulk
magnetization arises from field-induced nonequivalent Ru sites (magnetic
space-group Pm'c'21).",1902.02978v1
2019-11-18,Particle size controlled magnetic loss in magnetite nanoparticles in RF-microwave region,"Frequency dependant complex magnetic permeability is used to understand
RF-microwave behaviour of magnetic nanoparticles in the frequency range 250 MHz
to 3 GHz. The stable dispersions of Fe3O4 nanoparticles with mean size varying
between 11 to 16 nm are prepared for this purpose. The effect of mean particle
size and external static magnetic field over microwave absorption properties of
magnetic fluid is studied. It is observed that frequency of ferrimagnetic
resonance, frequency of maximum absorption, loss tangent and reflection loss
(RL) can be controlled by modifying mean particle size and strength of applied
external static magnetic field. This kind of study can be useful for
radio-microwave devices like tunable attenuator, EM sheilder, and other
applications like Hyperthermia.",1911.07467v1
2020-08-07,Cavity magnon polariton based precision magnetometry,"A photon-magnon hybrid system can be realised by coupling the electron spin
resonance of a magnetic material to a microwave cavity mode. The quasiparticles
associated with the system dynamics are the cavity magnon polaritons, which
arise from the mixing of strongly coupled magnons and photons. We illustrate
how these particles can be used to probe the magnetisation of a sample with a
remarkable sensitivity, devising suitable spin-magnetometers which ultimately
can be used to directly assess oscillating magnetic fields. Specifically, the
capability of cavity magnon polaritons of converting magnetic excitations to
electromagnetic ones, allows for translating to magnetism the quantum-limited
sensitivity reached by state-of-the-art electronics. Here we employ hybrid
systems composed of microwave cavities and ferrimagnetic spheres, to
experimentally implement two types of novel spin-magnetometers.",2008.03062v2
2020-08-15,Magnon laser based on Brillouin light scattering,"An analogous laser action of magnons would be a subject of interest and is
crucial for the study of nonlinear magnons spintronics. Here, we demonstrate
the magnon laser behavior based on Brillouin light scattering in a
ferrimagnetic insulator sphere which supports optical whispering gallery modes
and magnon resonances. We show that the excited magnon plays what has
traditionally been the role of the Stokes wave and is coherently amplified
during the Brillouin scattering process, making magnon laser possible.
Furthermore, the stimulating excited magnon number increasing exponentially
with the input light power can be manipulated by adjusting the external
magnetic field. In addition to providing insight into magneto-optical
interaction, the study of magnon laser action will help to develop novel
technologies for handling spin-wave excitations and could affect scientific
fields beyond magnonics. Potential applications range from preparing coherent
magnon sources to operating onchip functional magnetic devices.",2008.06628v2
2020-09-24,Magnetic anisotropy and exchange paths for octa- and tetrahedrally coordinated Mn$^{2+}$ ions in the honeycomb multiferroic Mn$_2$Mo$_3$O$_8$,"We investigated the static and dynamic magnetic properties of the polar
ferrimagnet Mn$_2$Mo$_3$O$_8$ in three magnetically ordered phases via
magnetization, magnetic torque, and THz absorption spectroscopy measurements.
The observed magnetic field dependence of the spin-wave resonances, including
Brillouin zone-center and zone-boundary excitations, magnetization, and torque,
are well described by an extended two-sublattice antiferromagnetic classical
mean-field model. In this orbitally quenched system, the competing weak
easy-plane and easy-axis single-ion anisotropies of the two crystallographic
sites are determined from the model and assigned to the tetra- and octahedral
sites, respectively, by ab initio calculations.",2009.11683v1
2021-03-10,Experimental Demonstration of a Rowland Spectrometer for Spin Waves,"We experimentally demonstrate the operation of a spin-wave Rowland
spectrometer. In the proposed device geometry, spin waves are coherently
excited on a diffraction grating and form an interference pattern that
spatially separates spectral components of the incoming signal. The diffraction
grating was created by focused-ion-beam irradiation, which was found to locally
eliminate the ferrimagnetic properties of YIG, without removing the material.
We found that in our experiments spin waves were created by an indirect
mechanism, by exploiting nonlinear resonance between the grating and the
coplanar waveguide. Our work paves the way for complex spin-wave optic devices
-- chips that replicate the functionality of integrated optical devices on a
chip-scale.",2103.06165v1
2021-05-22,Ferromagnetic resonance modes in the exchange dominated limit in cylinders of finite length,"We analyze the magnetic mode structure of axially-magnetized, finite-length,
nanoscopic cylinders in a regime where the exchange interaction dominates,
along with simulations of the mode frequencies of the ferrimagnet yttrium iron
garnet. For the bulk modes we find that the frequencies can be represented by
an expression given by Herring and Kittel by using wavevector components
obtained by fitting the mode patterns emerging from these simulations. In
addition to the axial, radial, and azimuthal modes that are present in an
infinite cylinder, we find localized ""cap modes"" that are ""trapped"" at the top
and bottom cylinder faces by the inhomogeneous dipole field emerging from the
ends. Semi-quantitative explanations are given for some of the modes in terms
of a one-dimensional Schrodinger equation which is valid in the exchange
dominant case. The assignment of the azimuthal mode number is carefully
discussed and the frequency splitting of a few pairs of nearly degenerate modes
is determined through the beat pattern emerging from them.",2105.10795v1
2023-03-27,Temperature dependent study of the spin dynamics of coupled Y$_3$Fe$_5$O$_{12}$/Gd$_3$Fe$_5$O$_{12}$/Pt trilayers,"In this study, we investigate the dynamic response of a Y$_3$Fe$_5$O$_{12}$
(YIG)/ Gd$_3$Fe$_5$O$_{12}$ (GdIG)/ Pt trilayer system by measurements of the
ferromagnetic resonance (FMR) and the pumped spin current detected by the
inverse spin Hall effect. This trilayer system offers the unique opportunity to
investigate the spin dynamics of the ferrimagnetic GdIG, close to its
compensation temperature. We show that our trilayer acts as a highly tunable
spin current source. Our experimental results are supported by micro-magnetic
simulations. As the detected spin current in the top Pt layer is distinctly
dominated by the GdIG layer, this gives the unique opportunity to investigate
the excitation and dynamic properties of GdIG while comparing it to the
broadband FMR absorption spectrum of the heterostructure.",2303.15085v1
2023-07-13,Magnon-magnon coupling in synthetic ferrimagnets,"Magnetic multilayers with interlayer exchange coupling have been widely
studied for both static and dynamic regimes. Their dynamical responses depend
on the exchange coupling strength and magnetic properties of individual layers.
Magnetic resonance spectra in such systems are conveniently discussed in terms
of coupling of acoustic and optical modes. At a certain value of applied
magnetic field, the two modes come close to being degenerate and the spectral
gap indicates the strength of mode hybridisation. In this work, we
theoretically and experimentally study the mode hybridisation of
interlayer-exchange-coupled moments with dissimilar magnetisation and thickness
of two ferromagnetic layers. In agreement with symmetry analysis for
eigenmodes, our low-symmetry multilayers exhibit sizable spectral gaps for all
experimental conditions. The spectra agree well with the predictions from the
Landau-Lifshitz-Gilbert equation at the macrospin limit whose parameters are
independently fixed by static measurements.",2307.06888v2
2023-09-22,Laser-induced real-space topology control of spin wave resonances,"Femtosecond laser excitation of materials that exhibit magnetic spin textures
promises advanced magnetic control via the generation of ultrafast and
non-equilibrium spin dynamics. We explore such possibilities in ferrimagnetic
[Fe(0.35 nm)/Gd(0.40 nm)]$_{160}$ multilayers, which host a rich diversity of
magnetic textures from stripe domains at low magnetic fields, a dense
bubble/skyrmion lattice at intermediate fields, and a single domain state for
high magnetic fields. Using femtosecond magneto-optics, we observe distinct
coherent spin wave dynamics in response to a weak laser excitation allowing us
to unambiguously identify the different magnetic spin textures. Moreover,
employing strong laser excitation we show that we achieve versatile control of
the coherent spin dynamics via non-equilibrium and ultrafast transformation of
magnetic spin textures by both creating and annihilating bubbles/skyrmions. We
corroborate our findings by micromagnetic simulations and by Lorentz
transmission electron microscopy before and after laser exposure.",2309.12956v1
2024-02-29,Nano-Electromagnetic Super-dephasing in Collective Atom-Atom Interactions,"Pure dephasing and spontaneous emission are two non-unitary processes of
atoms or spins interacting with fluctuating electromagnetic (EM) modes.
Collective spontaneous emission (e.g., superradiance) originates from
interactions with EM modes in resonance with atoms and has received
considerable attention. Meanwhile, the analogous collective dephasing phenomena
remain poorly understood. Here, we introduce the nano-EM super-dephasing
phenomenon arising in the photonic environment near lossy material interfaces.
We show that this effect is enhanced by over 10 orders of magnitude compared to
free space or photonic cavities due to the presence of long-range correlations
in low-frequency evanescent EM fluctuations. We unravel the universality of
nano-EM super-dephasing behaviors near ferrimagnets, metals, and
superconductors and their dependence on low-frequency material properties. We
demonstrate that the scaling of nano-EM super-dephasing is independent of EM
modes' wavelengths and differs from the conventional $N^2$ scaling of
superradiance by analyzing the decoherence of entangled states, including GHZ
states. Finally, we show how to experimentally isolate and control
super-dephasing to open interesting frontiers for scalable quantum systems.",2402.18816v1
2020-10-15,Unconventional superparamagnetic behavior in the modified cubic spinel compound LiNi$_{0.5}$Mn$_{1.5}$O$_{4}$,"Structural, electronic, and magnetic properties of modified cubic spinel
compound LiNi$_{0.5}$Mn$_{1.5}$O$_{4}$ are studied via x-ray diffraction,
resistivity, DC and AC magnetization, heat capacity, neutron diffraction,
$^7$Li nuclear magnetic resonance, magnetocaloric effect, magnetic relaxation,
and magnetic memory effect experiments. We stabilized this compound in a cubic
structure with space group $P4_{3}32$. It exhibits semiconducting character
with an electronic band gap of $\Delta/k_{\rm B} \simeq 0.4$ eV. The
interaction within each Mn$^{4+}$ and Ni$^{2+}$ sub-lattice and between
Mn$^{4+}$ and Ni$^{2+}$ sublattices is found to be ferromagnetic (FM) and
antiferromagnetic (AFM), respectively which leads to the onset of a
ferrimagnetic transition at $T_{\rm C} \simeq 125$~K. The reduced values of
frustration parameter ($f$) and ordered moments reflect magnetic frustration
due to competing FM and AFM interactions. From the $^7$Li NMR shift vs
susceptibility plot, the average hyperfine coupling between $^7$Li nuclei and
Ni$^{2+}$ and Mn$^{4+}$ spins is calculated to be $\sim 672.4$~Oe/$\mu_{\rm
B}$. A detailed critical behaviour study is done in the vicinity of $T_{\rm C}$
using modified-Arrott plot, Kouvel-Fisher plot, and universal scaling of
magnetization isotherms. The estimated critical exponents correspond to the 3D
XY universality class. A large magneto-caloric effect is observed with a
maximum isothermal change in entropy $\Delta S_m \simeq - 11.3$~J/Kg-K and a
maximum relative cooling power $RCP \simeq 604$~J/Kg for 9~T magnetic field
change. The imaginary part of the AC susceptibility depicts a strong frequency
dependent hump at $T=T_{\rm f2}$ well below the blocking temperature $T_{\rm
b}\simeq120$~K. The Arrhenius behaviour of frequency dependent $T_{\rm f2}$ and
the absence of ZFC memory confirm the existence of superparamagnetism in the
ferrimagnetically ordered state.",2010.07709v1
1998-03-12,Frustrated quantum Heisenberg ferrimagnetic chains,"We study the ground-state properties of weakly frustrated Heisenberg
ferrimagnetic chains with nearest and next-nearest neighbor antiferromagnetic
exchange interactions and two types of alternating sublattice spins S_1 > S_2,
using 1/S spin-wave expansions, density-matrix renormalization group, and
exact- diagonalization techniques. It is argued that the zero-point spin
fluctuations completely destroy the classical commensurate- incommensurate
continuous transition. Instead, the long-range ferrimagnetic state disappears
through a discontinuous transition to a singlet state at a larger value of the
frustration parameter. In the ferrimagnetic phase we find a disorder point
marking the onset of incommensurate real-space short-range spin-spin
correlations.",9803150v1
2002-06-27,Intrinsic double-peak structure of the specific heat in low-dimensional quantum ferrimagnets,"Motivated by recent magnetic measurements on A3Cu3(PO4)4 (A=Ca,Sr) and
Cu(3-Clpy)2(N3)2 (3-Clpy=3-Chloropyridine), both of which behave like
one-dimensional ferrimagnets, we extensively investigate the ferrimagnetic
specific heat with particular emphasis on its double-peak structure. Developing
a modified spin-wave theory, we reveal that ferromagnetic and antiferromagnetic
dual features of ferrimagnets may potentially induce an extra low-temperature
peak as well as a Schottky-type peak at mid temperatures in the specific heat.",0206555v1
2006-06-12,Defects in CrAs and related compounds: a route to half-metallic ferrimagnetism,"Half-metallic ferrimagnetism is crucial for spintronic applications with
respect to ferromagnets due to the lower stray fields created by these
materials. Studying the effect of defects in CrAs and related transition-metal
chalcogenides and pnictides crystallizing in the zinc-blende structure, we
reveal that the excess of the transition-metal atoms leads to half-metallic
ferrimagnetism. The surplus of these atoms are antiferromagnetically coupled to
the transition-metal atoms sitting at the perfect lattice sites. The needed
condition to achieve half-metallic ferrimagnetism is to prevent the migration
of the $sp$ atoms to other sites and the atomic swaps.",0606286v1
2007-05-25,Ferrimagnetism and antiferromagnetism in half-metallic Heusler alloys,"Half-metallic Heusler alloys are among the most promising materials for
future applications in spintronic devices. Although most Heusler alloys are
ferromagnets, ferrimagnetic or antiferromagnetic (also called fully-compensated
ferrimagnetic) alloys would be more desirable for applications due to the lower
external fields. Ferrimagnetism can be either found in perfect Heusler
compounds or achieved through the creation of defects in ferromagnetic Heusler
alloys.",0705.3731v1
2008-05-23,Frustration Induced Quantum Phases in Mixed Spin Chain with Frustrated Side Chains,"A mixed Heisenberg spin chain with frustrated side chains is investigated by
numerical and perturbational calculations. A frustration-induced quantum
partially polarized ferrimagnetic phase and a nonmagnetic spin quadrupolar
phase are found adjacent to the conventional Lieb-Mattis type ferrimagnetic
phase or the nonmagnetic singlet cluster solid phases. The partially polarized
ferrimagnetic phase has an incommensurate spin structure. Similar structures
are commonly found in other frustration-induced partially polarized
ferrimagnetic phases. Numerical results also suggest a series of almost
critical nonmagnetic ground states in a highly frustrated regime if the side
chain spins weakly couple to the main chain.",0805.3604v2
2008-11-15,Half-metallic ferrimagnet formed by substituting Fe for Mn in semiconductor MnTe,"A ternary ferrimagnetic half-metal, constructed through substituting 25% Fe
for Mn in zincblende semiconductor MnTe, is predicted in terms of accurate
first-principles calculations. It has a large half-metallic (HM) gap of 0.54eV
and its ferrimagnetic order is very stable against other magnetic fluctuations.
The HM ferrimagnetism is formed because the complete moment compensation in the
antiferromagnetic MnTe is replaced by an uncomplete one in the Fe-substituted
MnTe. This should make a novel approach to new HM materials. The half-metal
could be fabricated because Fe has good affinity with Mn, and useful for
spintronics.",0811.2455v1
2010-02-24,Evidence of Ferrimagnetism in Ferromagnetic La0_{67}Ca0_{33}MnO_3 nanoparticle,"The present report is dedicated to show that ferromagnetic La0.67Ca0.33MnO3
(LCMN) particles can be better described in the framework of ferrimagnetic
model. To confirm the ferrimagnetic signature in ferromagnetic LCMN particles,
the temperature dependence of the inverse of magnetic susceptibility in the
paramagnetic state of the samples was taken as a tool of data analysis. The
observed ferrimagnetism is understood as an effect of of the core-shell spin
structure in LCMN particles.",1002.4574v2
2013-01-21,Ferrimagnetism of dilute Ising antiferromagnets,"It is shown that nearest-neighbor antiferromagnetic interactions of identical
Ising spins on imbalanced bipartite lattice and imbalanced bipartite
hierarchical fractal result in ferrimagnetic order instead of antiferromagnetic
one. On some crystal lattices dilute Ising antiferromagnets may also become
ferrimagnets due to the imbalanced nature of the magnetic percolation cluster
when it coexists with the percolation cluster of vacancies. As evidenced by the
existing experiments on $Fe_pZn_{1-p}F_2$, such ferrimagnetism is inherent
property of bcc lattice so thermodynamics of these compounds at low $p$ can be
similar to that of antiferromagnet on imbalanced hierarchical fractal.",1301.4754v3
2014-03-06,Spontaneously magnetized Tomonaga-Luttinger liquid in frustrated quantum antiferromagnets,"We develop a theory of spontaneously magnetized Tomonaga-Luttinger liquid
(SMTLL) in geometrically frustrated quasi-one-dimensional quantum magnets by
taking an $S=1/2$ ferrimagnet on a union-jack lattice as an example. We show
that a strong frustration leads to a spontaneous magnetization because of the
ferrimagnetic nature of lattice. Due to the ferrimagnetic order, the local
magnetization has an incommensurate oscillation with the position. We show that
the spontaneously magnetized TLL is smoothly connected to the existence of a
Nambu-Goldstone boson in the canted ferrimagnetic phase of a two-dimensional
frustrated antiferromagnet.",1403.1513v2
2021-02-22,A review of modelling in ferrimagnetic spintronics,"In this review we introduce computer modelling and simulation techniques
which are used for ferrimagnetic materials. We focus on models where thermal
effects are accounted for, atomistic spin dynamics and finite temperature
macrospin approaches. We survey the literature of two of the most commonly
modelled ferrimagnets in the field of spintronics--the amorphous alloy GdFeCo
and the magnetic insulator yttrium iron garnet. We look at how generic models
and material specific models have been applied to predict and understand
spintronic experiments, focusing on the fields of ultrafast magnetisation
dynamics, spincaloritronics and magnetic textures dynamics and give an outlook
for modelling in ferrimagnetic spintronics.",2102.11004v1
2012-08-31,Magnetic symmetry of the plain domain walls in the plates of cubic ferro- and ferrimagnets,"Magnetic symmetry of possible plane domain walls in arbitrary oriented plates
of the crystal of hexoctahedral crystallographic class is considered. The
symmetry classification is applied for ferro- and ferrimagnets.",1209.0004v1
2007-07-13,Effect of antiferromagnetic exchange interactions on the Glauber dynamics of one-dimensional Ising models,"We study the effect of antiferromagnetic interactions on the single spin-flip
Glauber dynamics of two different one-dimensional (1D) Ising models with spin
$\pm 1$. The first model is an Ising chain with antiferromagnetic exchange
interaction limited to nearest neighbors and subject to an oscillating magnetic
field. The system of master equations describing the time evolution of
sublattice magnetizations can easily be solved within a linear field
approximation and a long time limit. Resonant behavior of the magnetization as
a function of temperature (stochastic resonance) is found, at low frequency,
only when spins on opposite sublattices are uncompensated owing to different
gyromagnetic factors (i.e., in the presence of a ferrimagnetic short range
order). The second model is the axial next-nearest neighbor Ising (ANNNI)
chain, where an antiferromagnetic exchange between next-nearest neighbors (nnn)
is assumed to compete with a nearest-neighbor (nn) exchange interaction of
either sign. The long time response of the model to a weak, oscillating
magnetic field is investigated in the framework of a decoupling approximation
for three-spin correlation functions, which is required to close the system of
master equations. The calculation, within such an approximate theoretical
scheme, of the dynamic critical exponent z, defined as ${1/\tau} \approx ({1/
{\xi}})^z$ (where \tau is the longest relaxation time and \xi is the
correlation length of the chain), suggests that the T=0 single spin-flip
Glauber dynamics of the ANNNI chain is in a different universality class than
that of the unfrustrated Ising chain.",0707.1953v1
2013-04-10,Magnetization and spin dynamics of the spin S=1/2 hourglass nanomagnet Cu5(OH)2(NIPA)4*10H2O,"We report a combined experimental and theoretical study of the spin S=1/2
nanomagnet Cu5(OH)2(NIPA)4*10H2O (Cu5-NIPA). Using thermodynamic, electron spin
resonance and 1H nuclear magnetic resonance measurements on one hand, and ab
initio density-functional band-structure calculations, exact diagonalizations
and a strong coupling theory on the other, we derive a microscopic magnetic
model of Cu5-NIPA and characterize the spin dynamics of this system. The
elementary five-fold Cu2+ unit features an hourglass structure of two
corner-sharing scalene triangles related by inversion symmetry. Our microscopic
Heisenberg model comprises one ferromagnetic and two antiferromagnetic exchange
couplings in each triangle, stabilizing a single spin S=1/2 doublet ground
state (GS), with an exactly vanishing zero-field splitting (by Kramer's
theorem), and a very large excitation gap of \Delta~68 K. Thus, Cu5-NIPA is a
good candidate for achieving long electronic spin relaxation (T1) and coherence
(T2) times at low temperatures, in analogy to other nanomagnets with low-spin
GS's. Of particular interest is the strongly inhomogeneous distribution of the
GS magnetic moment over the five Cu2+ spins. This is a purely
quantum-mechanical effect since, despite the non-frustrated nature of the
magnetic couplings, the GS is far from the classical collinear ferrimagnetic
configuration. Finally, Cu5-NIPA is a rare example of a S=1/2 nanomagnet
showing an enhancement in the nuclear spin-lattice relaxation rate 1/T1 at
intermediate temperatures.",1304.2826v1
2018-02-20,Magnon-photon coupling in a non-collinear magnetic insulator Cu$_2$OSeO$_3$,"Anticrossing behavior between magnons in a non-collinear chiral magnet
Cu$_2$OSeO$_3$ and a two-mode X-band microwave resonator was studied in the
temperature range 5-100K. In the field-induced ferrimagnetic phase, we observed
a strong coupling regime between magnons and two microwave cavity modes with a
cooperativity reaching 3600. In the conical phase, cavity modes are
dispersively coupled to a fundamental helimagnon mode, and we demonstrate that
the magnetic phase diagram of Cu$_2$OSeO$_3$ can be reconstructed from the
measurements of the cavity resonance frequency. In the helical phase, a
hybridized state of a higher-order helimagnon mode and a cavity mode - a
helimagnon polariton - was found. Our results reveal a new class of magnetic
systems where strong coupling of microwave photons to non-trivial spin textures
can be observed.",1802.07113v3
2021-09-09,Chiral Cavity Quantum Electrodynamics,"Cavity quantum electrodynamics, which explores the granularity of light by
coupling a resonator to a nonlinear emitter, has played a foundational role in
the development of modern quantum information science and technology. In
parallel, the field of condensed matter physics has been revolutionized by the
discovery of underlying topological robustness in the face of disorder, often
arising from the breaking of time-reversal symmetry, as in the case of the
quantum Hall effect. In this work, we explore for the first time cavity quantum
electrodynamics of a transmon qubit in the topological vacuum of a
Harper-Hofstadter topological lattice. To achieve this, we assemble a square
lattice of niobium superconducting resonators and break time-reversal symmetry
by introducing ferrimagnets before coupling the system to a single transmon
qubit. We spectroscopically resolve the individual bulk and edge modes of this
lattice, detect vacuum-stimulated Rabi oscillations between the excited
transmon and each mode, and thereby measure the synthetic-vacuum-induced Lamb
shift of the transmon. Finally, we demonstrate the ability to employ the
transmon to count individual photons within each mode of the topological band
structure. This work opens the field of chiral quantum optics experiment,
suggesting new routes to topological many-body physics and offering unique
approaches to backscatter-resilient quantum communication.",2109.06033v1
2024-02-01,"Element-specific and high-bandwidth ferromagnetic resonance spectroscopy with a coherent, extreme ultraviolet (EUV) source","We developed and applied a tabletop, ultrafast, high-harmonic generation
(HHG) source to measure the element-specific ferromagnetic resonance (FMR) in
ultra-thin magnetic alloys and multilayers on an opaque Si substrate. We
demonstrate a continuous wave bandwidth of 62 GHz, with promise to extend to
100 GHz or higher. This laboratory-scale instrument detects the FMR using
ultrafast, extreme ultraviolet (EUV) light, with photon energies spanning the
M-edges of most relevant magnetic elements. An RF frequency comb generator is
used to produce a microwave excitation that is intrinsically synchronized to
the EUV pulses with a timing jitter of 1.4 ps or better. We apply this system
to measure the dynamics in a multilayer system as well as Ni-Fe and Co-Fe
alloys. Since this instrument operates in reflection-mode, it is a milestone
toward measuring and imaging the dynamics of the magnetic state and spin
transport of active devices on arbitrary and opaque substrates. The higher
bandwidth also enables measurements of materials with high magnetic anisotropy,
as well as ferrimagnets, antiferromagnets, and short-wavelength (high
wavevector) spinwaves in nanostructures or nanodevices. Furthermore, the
coherence and short wavelength of the EUV will enable extending these studies
using dynamic nanoscale lensless imaging techniques such as coherent
diffractive imaging, ptychography, and holography.",2402.00783v1
2011-02-22,Frustration-Induced Ferrimagnetism in S=1/2 Heisenberg Spin Chain,"The ground-state properties of the S=1/2 frustrated Heisenberg spin chain
with interactions up to fourth nearest neighbors are investigated by the
exact-diagonalization method and density matrix renormalization group method.
Our numerical calculations clarify that the ferrimagnetic state is realized in
the ground state in spite of the fact that a multi-sublattice structure in the
shape of the system is absent. We find that there are two types of
ferrimagnetic phases: one is the well-known ferrimagnetic phase of the
Lieb-Mattis type and the other is the nontrivial ferrimagnetic phase that is
different from that of the Lieb-Mattis type. Our results suggest that a
multi-sublattice structure of the shape is not necessarily required for the
occurrence of ferrimagnetism.",1102.4414v1
2011-12-07,Magnetization and spin gap in two-dimensional organic ferrimagnet BIPNNBNO,"A magnetization process in two-dimensional ferrimagnet BIPNNBNO is analyzed.
The compound consists of ferrimagnetic (1,1/2) chains coupled by two sorts of
antiferromagnetic interactions. Whereas a behavior of the magnetization curve
in higher magnetic fields can be understood within a process for the separate
ferrimagnetic chain, an appearance of the singlet plateau at lower fields is an
example of non-Lieb-Mattis type ferrimagnetism. By using the exact
diagonalization technique for a finite clusters of sizes 4x8 and 4x10 we show
that the interchain frustration coupling plays an essential role in
stabilization of the singlet phase. These results are complemented by an
analysis of four cylindrically coupled ferrimagnetic (1,1/2) chains via an
abelian bosonization technique and an effective theory based on the XXZ
spin-1/2 Heisenberg model when the interchain interactions are sufficiently
weak/strong, respectively.",1112.1646v1
2015-03-02,Frustrated mixed spin-1/2 and spin-1 Ising ferrimagnets on a triangular lattice,"Mixed spin-1/2 and spin-1 Ising ferrimagnets on a triangular lattice with
sublattices A, B and C are studied for two spin value distributions $(S_{\rm
A},S_{\rm B},S_{\rm C})=(1/2,1/2,1)$ and $(1/2,1,1)$ by Monte Carlo
simulations. The non-bipartite character of the lattice induces geometrical
frustration in both systems, which leads to the critical behavior rather
different from their ferromagnetic counterparts. We confirm second-order phase
transitions belonging to the standard Ising universality class occurring at
higher temperatures, however, in both models these change at tricritical points
(TCP) to first-order transitions at lower temperatures. In the model
$(1/2,1/2,1)$, TCP occurs on the boundary between paramagnetic and
ferrimagnetic $(\pm 1/2,\pm 1/2,\mp 1)$ phases. The boundary between two
ferrimagnetic phases $(\pm 1/2,\pm 1/2,\mp 1)$ and $(\pm 1/2,\mp 1/2,0)$ at
lower temperatures is always first order and it is joined by a line of
second-order phase transitions between the paramagnetic and the ferrimagnetic
$(\pm 1/2,\mp 1/2,0)$ phases at a critical endpoint. The tricritical behavior
is also confirmed in the model $(1/2,1,1)$ on the boundary between the
paramagnetic and ferrimagnetic $(0,\pm 1,\mp 1)$ phases.",1503.00589v2
2015-05-04,Spiral ferrimagnetic phases in the two-dimensional Hubbard model,"We address the possibility of spiral ferrimagnetic phases in the mean-field
phase diagram of the two-dimensional (2D) Hubbard model. For intermediate
values of the interaction $U$ ($6 \lesssim U/t \lesssim 11$) and doping $n$, a
spiral ferrimagnetic phase is the most stable phase in the $(n,U)$ phase
diagram. Higher values of $U$ lead to a non-spiral ferrimagnetic phase. If
phase separation is allowed and the chemical potential $\mu$ replaces the
doping $n$ as the independent variable, the $(\mu,U)$ phase diagram displays,
in a considerable region, a spiral (for $6 \lesssim U/t \lesssim 11$) and
non-spiral (for higher values of $U$) ferrimagnetic phase with fixed particle
density, $n=0.5$, reflecting the opening of an energy gap in the mean-field
quasi-particle bands.",1505.00583v1
2019-05-06,Ground State Phases of Distorted $S=1$ Diamond Chains,"The ground states of distorted $S=1$ diamond chains are investigated for two
types of distortion called type A and B [J. Phys. Soc. Jpn. 79 (2010) 114703].
For the type A distortion, Haldane phases with and without spontaneous
translational symmetry breakdown are present for large values of parameter
$\lambda$ that parametrize the strength of frustration. For small $\lambda$,
the Haldane phase and two quantized ferrimagnetic phases in the undistorted
chain remain stable even for strong distortion. In contrast, for the type B
distortion, the quantized ferrimagnetic phases with and without spontaneous
translational symmetry breakdown are present for large $\lambda$. The partial
ferrimagnetic phases emerge between them. For small $\lambda$, two quantized
ferrimagnetic phases remain and the partial ferrimagnetic phases also emerge
between them. The Haldane phase between the two kinds of ferrimagnetic phases
turns into a topologically trivial double Haldane phase for strong distortion.",1905.02117v2
2019-11-01,Tuning interfacial Dzyaloshinskii-Moriya interactions in thin amorphous ferrimagnetic alloys,"Skyrmions can be stabilized in magnetic systems with broken inversion
symmetry and chiral interactions, such as Dzyaloshinskii-Moriya interactions
(DMI). Further, compensation of magnetic moments in ferrimagnetic materials can
significantly reduce magnetic dipolar interactions, which tend to favor large
skyrmions. Tuning DMI is essential to control skyrmion properties, with
symmetry breaking at interfaces offering the greatest flexibility. However, in
contrast to the ferromagnet case, few studies have investigated interfacial DMI
in ferrimagnets. Here we present a systematic study of DMI in ferrimagnetic
CoGd films by Brillouin light scattering. We demonstrate the ability to control
DMI by the CoGd cap layer composition, the stack symmetry and the ferrimagnetic
layer thickness. The DMI thickness dependence confirms its interfacial nature.
In addition, magnetic force microscopy reveals the ability to tune DMI in a
range that stabilizes sub-100 nm skyrmions at room temperature in zero field.
Our work opens new paths for controlling interfacial DMI in ferrimagnets to
nucleate and manipulate skyrmions.",1911.00607v1
2021-04-30,Current-Induced Magnetization Control in Insulating Ferrimagnetic Garnets,"The research into insulating ferrimagnetic garnets has gained enormous
momentum in the past decade. This is partly due to the improvement in the
techniques to grow high-quality ultrathin films with desirable properties and
the advances in understanding the spin transport within the ferrimagnetic
garnets and through their interfaces with conducting materials. In recent
years, we have seen remarkable progress in controlling the magnetization state
of ferrimagnetic garnets by electrical means in suitable heterostructures and
device architectures. These advances have readily placed ferrimagnetic garnets
in a favorable position for the future development of insulating spintronic
concepts. The purpose of this article is to review recent experimental results
of the current-induced magnetization control and associated phenomena in
ferrimagnetic garnets, as well as to discuss future directions in this rapidly
evolving area of spintronics.",2104.14819v1
2021-09-01,Epitaxial Integration of a Perpendicularly Magnetized Ferrimagnetic Metal on a Ferroelectric oxide for Electric-Field Control,"Ferrimagnets, which contain the advantages of both ferromagnets (detectable
moments) and antiferromagnets (ultrafast spin dynamics), have recently
attracted great attention. Here we report the optimization of epitaxial growth
of a tetragonal perpendicularly magnetized ferrimagnet Mn2Ga on MgO. Electrical
transport, magnetic properties and the anomalous Hall effect (AHE) were
systematically studied. Furthermore, we successfully integrated high-quality
epitaxial ferrimagnetic Mn2Ga thin films onto ferroelectric PMN-PT single
crystals with a MgO buffer layer. It was found that the AHE of such a
ferrimagnet can be effectively modulated by a small electric field over a large
temperature range in a nonvolatile manner. This work thus demonstrates the
great potential of ferrimagnets for developing high-density and low-power
spintronic devices.",2109.00169v1
2021-11-23,Dynamics of ferrimagnetic skyrmionium driven by spin-orbit torque,"Magnetic skyrmionium is a skyrmion-like spin texture with nanoscale size and
high mobility. It is a topologically trivial but dynamically stable structure,
which can be used as a non-volatile information carrier for next-generation
spintronic storage and computing devices. Here, we study the dynamics of a
skyrmionium driven by the spin torque in a ferrimagnetic nanotrack. It is found
that the direction of motion is jointly determined by the internal
configuration of a skyrmionium and the spin polarization vector. Besides, the
deformation of a skyrmionium induced by the intrinsic skyrmion Hall effect
depends on both the magnitude of the driving force and the net angular
momentum. The ferrimagnetic skyrmionium is most robust at the angular momentum
compensation point, whose dynamics is quite similar to the skyrmionium in
antiferromagnet. The skyrmion Hall effect is perfectly prohibited, where it is
possible to observe the position of the skyrmionium by measuring the
magnetization. Furthermore, the current-induced dynamics of a ferrimagnetic
skyrmionium is compared with that of a ferromagnetic and antiferromagnetic
skyrmionium. We also make a comparison between the motion of a ferrimagnetic
skyrmionium and a skyrmion. Our results will open a new field of ferrimagnetic
skyrmioniums for future development of ferrimagnetic spintronics devices.",2111.11603v1
2002-05-09,Evidence of strong antiferromagnetic coupling between localized and itinerant electrons in ferromagnetic Sr2FeMoO6,"Magnetic dc susceptibility ($\chi$) and electron spin resonance (ESR)
measurements in the paramagnetic regime, are presented. We found a Curie-Weiss
(CW) behavior for $\chi$(T) with a ferromagnetic $\Theta = 446(5)$ K and
$\mu_{eff} = 4.72(9) \mu_{B}/f.u.$, this being lower than that expected for
either $Fe^{3+}(5.9\mu_{B})$ or $Fe^{2+}(4.9\mu_{B})$ ions. The ESR g-factor $g
= 2.01(2)$, is associated with $Fe^{3+}$. We obtained an excellent description
of the experiments in terms of two interacting sublattices: the localized
$Fe^{3+}$ ($3d^{5}$) cores and the delocalized electrons. The coupled equations
were solved in a mean-field approximation, assuming for the itinerant electrons
a bare susceptibility independent on $T$. We obtained $\chi_{e}^{0} = 3.7$
$10^{-4}$ emu/mol. We show that the reduction of $\mu_{eff}$ for $Fe^{3+}$
arises from the strong antiferromagnetic (AFM) interaction between the two
sublattices. At variance with classical ferrimagnets, we found that $\Theta$ is
ferromagnetic. Within the same model, we show that the ESR spectrum can be
described by Bloch-Hasegawa type equations. Bottleneck is evidenced by the
absence of a $g$-shift. Surprisingly, as observed in CMR manganites, no
narrowing effects of the ESR linewidth is detected in spite of the presence of
the strong magnetic coupling. These results provide evidence that the magnetic
order in $Sr_{2}FeMoO_{6}$ does not originates in superexchange interactions,
but from a novel mechanism recently proposed for double perovskites.",0205187v1
2013-05-14,Long-range FMR driven spin pumping through a nonmagnetic insulator,"Ferromagnetic resonance (FMR) driven spin pumping is an emerging technique
for injection of a pure spin current from a ferromagnet (FM) into a
non-magnetic (NM) material without an accompanying charge current. It is widely
believed that this pumping proceeds exclusively via a short-range exchange
interaction at the FM/NM interface. Here we report robust, long-range spin
pumping from the ferrimagnetic double perovskite Sr2FeMoO6 (SFMO) into Pt
across an insulating barrier up to 200 nm thick, and systematically rule out
all known spurious effects. This result demonstrates dynamic spin injection
over a distance far beyond the coupling range of the exchange interaction,
exposing the need to consider other coupling mechanisms. The characteristic
length scale for magnetic textures in Sr2FeMoO6 is approximately 150 nm,
resulting from structural antiphase boundaries, thus raising the possibility
that magnetic dipole coupling underlies the observed long range spin transfer.
This discovery reveals a route to dynamic angular momentum transfer between a
FM and a NM in the absence of mediation by itinerant electrons and promises new
spin-functional devices employing long-range spin pumping.",1305.3016v2
2014-09-03,Nanoscale confinement of all-optical switching in TbFeCo using plasmonic antennas,"All-optical switching (AOS) of magnetic domains by femtosecond laser pulses
was first observed in the transition metal-rare earth (TM-RE) alloy GdFeCo1-5;
this phenomenon demonstrated the potential for optical control of magnetism for
the development of ever faster future magnetic recording technologies. The
technological potential of AOS has recently increased due to the discovery of
the same effect in other materials, including RE-free magnetic multilayers6,7.
However, to be technologically meaningful, AOS must compete with the bit
densities of conventional storage devices, restricting optically-switched
magnetic areas to sizes well below the diffraction limit. Here, we demonstrate
reproducible and robust all-optical switching of magnetic domains of 53 nm size
in a ferrimagnetic TbFeCo alloy using gold plasmonic antenna structures. The
confined nanoscale magnetic reversal is imaged around and beneath plasmonic
antennas using x-ray resonant holographic imaging. Our results demonstrate the
potential of future AOS-based magnetic recording technologies.",1409.1280v1
2020-07-24,"Determination of the spin Hall angle, spin mixing conductance and spin diffusion length in Ir/CoFeB for spin-orbitronic devices","Iridium is a very promising material for spintronic applications due to its
interesting magnetic properties such as large RKKY exchange coupling as well as
its large spin-orbit coupling value. Ir is for instance used as a spacer layer
for perpendicular synthetic antiferromagnetic or ferrimagnet systems. However,
only a few studies of the spintronic parameters of this material have been
reported. In this paper, we present inverse spin Hall effect - spin pumping
ferromagnetic resonance measurements on CoFeB/Ir based bilayers to estimate the
values of the effective spin Hall angle, the spin diffusion length within
iridium, and the spin mixing conductance in the CoFeB/Ir bilayer. In order to
have reliable results, we performed the same experiments on CoFeB/Pt bilayers,
which behavior is well known due to numerous reported studies. Our experimental
results show that the spin diffusion length within iridium is 1.3 nm for
resistivity of 250 n$\Omega$.m, the spin mixing conductance $g_{eff}^{\uparrow
\downarrow}$ of the CoFeB/Ir interface is 30 nm$^{-2}$, and the spin Hall angle
of iridium has the same sign than the one of platinum and is evaluated at 26%
of the one of platinum. The value of the spin Hall angle found is 7.7% for Pt
and 2% for Ir. These relevant parameters shall be useful to consider Ir in new
concepts and devices combining spin-orbit torque and spin-transfer torque.",2007.12413v1
2017-12-21,Exchange-torque-induced excitation of perpendicular standing spin waves in nanometer-thick YIG films,"Spin waves in ferrimagnetic yttrium iron garnet (YIG) films with ultralow
magnetic damping are relevant for magnon-based spintronics and low-power
wave-like computing. The excitation frequency of spin waves in YIG is rather
low in weak external magnetic fields because of its small saturation
magnetization, which limits the potential of YIG films for high-frequency
applications. Here, we demonstrate how exchange-coupling to a CoFeB film
enables efficient excitation of high-frequency perpendicular standing spin
waves (PSSWs) in nanometer-thick (80 nm and 295 nm) YIG films using uniform
microwave magnetic fields. In the 295-nm-thick YIG film, we measure intense
PSSW modes up to 10th order. Strong hybridization between the PSSW modes and
the ferromagnetic resonance mode of CoFeB leads to characteristic anti-crossing
behavior in broadband spin-wave spectra. A dynamic exchange torque at the
YIG/CoFeB interface explains the excitation of PSSWs. The localized torque
originates from exchange coupling between two dissimilar magnetization
precessions in the YIG and CoFeB layers. As a consequence, spin waves are
emitted from the YIG/CoFeB interface and PSSWs form when their wave vector
matches the perpendicular confinement condition. PSSWs are not excited when the
exchange coupling between YIG and CoFeB is suppressed by a Ta spacer layer.
Micromagnetic simulations confirm the exchange-torque mechanism.",1712.08204v1
2020-04-06,Magnetic and vibronic THz excitations in Zn doped Fe$_{2}$Mo$_3$O$_8$,"We report on optical excitations in the magnetically ordered phases of
multiferroic Fe$_{1.86}$Zn$_{0.14}$Mo$_3$O$_8$ in the frequency range from
10-130 cm$^{-1}$ (0.3-3.9 THz). In the collinear easy-axis antiferromagnetic
phase below $T_N=50$~K eleven optically active modes have been observed in
finite magnetic fields, assuming that the lowest-lying mode is doubly
degenerate. The large number of modes reflects either a more complex magnetic
structure than in pure Fe$_{2}$Mo$_3$O$_8$ or that spin stretching modes become
active in addition to the usual spin precessional modes. Their magnetic field
dependence, for fields applied along the easy axis, reflects the irreversible
magnetic-field driven phase transition from the antiferromagnetic ground state
to a ferrimagnetic state, while the number of modes remains unchanged in the
covered frequency region. We determined selection rules for some of the AFM
modes by investigating all polarization configurations and identified magnetic-
and electric-dipole active modes as well. In addition to these sharp
resonances, a broad electric-dipole active excitation band, which is not
influenced by the external magnetic field, occurs below $T_N$ with an onset at
12 cm$^{-1}$. We are able to model this absorption band as a vibronic
excitation related to the lowest-lying Fe$^{2+}$ electronic states in
tetrahedral environment.",2004.02443v2
2018-07-23,Tilted and type-III Dirac cones emerging from flat bands in photonic orbital graphene,"The extraordinary electronic properties of Dirac materials, the
two-dimensional partners of Weyl semimetals, arise from the linear crossings in
their band structure. When the dispersion around the Dirac points is tilted,
the emergence of intricate transport phenomena has been predicted, such as
modified Klein tunnelling, intrinsic anomalous Hall effects and ferrimagnetism.
However, Dirac materials are rare, particularly with tilted Dirac cones.
Recently, artificial materials whose building blocks present orbital degrees of
freedom have appeared as promising candidates for the engineering of exotic
Dirac dispersions. Here we take advantage of the orbital structure of photonic
resonators arranged in a honeycomb lattice to implement photonic lattices with
semi-Dirac, tilted and, most interestingly, type-III Dirac cones that combine
flat and linear dispersions. The tilted cones emerge from the touching of a
flat and a parabolic band with a non-trivial topological charge. These results
open the way to the synthesis of orbital Dirac matter with unconventional
transport properties and, in combination with polariton nonlinearities, to the
study of topological and Dirac superfluids in photonic lattices.",1807.08650v1
2018-12-02,Direct detection of induced magnetic moment and efficient spin-to-charge conversion in graphene/ferromagnetic structures,"This article shows that the spin-to-charge current conversion in single-layer
graphene (SLG) by means of the inverse Rashba-Edelstein effect (IREE) is made
possible with the integration of this remarkable 2D-material with the unique
ferrimagnetic insulator yttrium iron garnet (YIG = $Y_{3}Fe_{5}O_{12}$) as well
as with the ferromagnetic metal permalloy (Py = $Ni_{81}Sb_{19}$). By means of
X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD)
techniques, we show that the carbon atoms of the SLG acquires an induced
magnetic moment due to the proximity effect with the magnetic layer. The spin
currents are generated in the magnetic layer by spin pumping from microwave
driven ferromagnetic resonance and are detected by a dc voltage along the
graphene layer, at room temperature. The spin-to-charge current conversion,
occurring at the graphene layer, is explained by the extrinsic spin-orbit
interaction (SOI) induced by the proximity effect with the ferromagnetic layer.
The results obtained for the SLG/YIG and SLG/Py systems confirm very similar
values for the IREE parameter, which are larger than the values reported in
previous studies for SLG. We also report systematic investigations of the
electronic and magnetic properties of the SLG/YIG by means of scanning
tunneling microscopy (STM).",1812.00455v1
2020-06-01,Enhancement in Thermally Generated Spin Voltage at Pd/NiFe$_2$O$_4$ Interfaces by the Growth on Lattice-Matched Substrates,"Efficient spin injection from epitaxial ferrimagnetic NiFe$_2$O$_4$ thin
films into a Pd layer is demonstrated via spin Seebeck effect measurements in
the longitudinal geometry. The NiFe$_2$O$_4$ films (60 nm to 1 $\mu$m) are
grown by pulsed laser deposition on isostructural spinel MgAl$_2$O$_4$,
MgGa$_2$O$_4$, and CoGa$_2$O$_4$ substrates with lattice mismatch varying
between 3.2% and 0.2%. For the thinner films ($\leq$ 330 nm), an increase in
the spin Seebeck voltage is observed with decreasing lattice mismatch, which
correlates well with a decrease in the Gilbert damping parameter as determined
from ferromagnetic resonance measurements. High resolution transmission
electron microscopy studies indicate substantial decrease of antiphase boundary
and interface defects that cause strain-relaxation, i.e., misfit dislocations,
in the films with decreasing lattice mismatch. This highlights the importance
of reducing structural defects in spinel ferrites for efficient spin injection.
It is further shown that angle-dependent spin Seebeck effect measurements
provide a qualitative method to probe for in-plane magnetic anisotropies
present in the films.",2006.00777v1
2021-08-25,Quantum network with magnonic and mechanical nodes,"A quantum network consisting of magnonic and mechanical nodes connected by
light is proposed. Recent years have witnessed a significant development in
cavity magnonics based on collective spin excitations in ferrimagnetic
crystals, such as yttrium iron garnet (YIG). Magnonic systems are considered to
be a promising building block for a future quantum network. However, a major
limitation of the system is that the coherence time of the magnon excitations
is limited by their intrinsic loss (typically in the order of 1 $\mu$s for
YIG). Here, we show that by coupling the magnonic system to a mechanical system
using optical pulses, an arbitrary magnonic state (either classical or quantum)
can be transferred to and stored in a distant long-lived mechanical resonator.
The fidelity depends on the pulse parameters and the transmission loss. We
further show that the magnonic and mechanical nodes can be prepared in a
macroscopic entangled state. These demonstrate the quantum state transfer and
entanglement distribution in such a novel quantum network of magnonic and
mechanical nodes. Our work shows the possibility to connect two separate fields
of optomagnonics and optomechanics, and to build a long-distance quantum
network based on magnonic and mechanical systems.",2108.11156v3
2021-12-13,Fluctuating magnetic droplets immersed in a sea of quantum spin liquid,"The search of quantum spin liquid (QSL), an exotic magnetic state with
strongly-fluctuating and highly-entangled spins down to zero temperature, is a
main theme in current condensed matter physics. However, there is no
smoking-gun evidence for deconfined spinons in any QSL candidate so far. The
disorders and competing exchange interactions may prevent the formation of an
ideal QSL state on frustrated spin lattices. Here we report comprehensive and
systematic measurements of the magnetic susceptibility, ultra-low temperature
specific heat, muon spin relaxation (muSR), nuclear magnetic resonance (NMR),
and thermal conductivity for NaYbSe2 single crystals, in which Yb3+ ions with
effective spin-1/2 form a perfect triangular lattice. All these complementary
techniques find no evidence of long-range magnetic order down to their
respective base temperatures. Instead, specific heat, muSR and NMR measurements
suggest the coexistence of quasi-static and dynamic spins in NaYbSe2. The
scattering from these quasi-static spins may cause the absence of magnetic
thermal conductivity. Thus, we propose a scenario of fluctuating ferrimagnetic
droplets immersed in a sea of QSL. This may be quite common on the way pursuing
an ideal QSL, and provides a brand-new platform to study how a QSL state
survives impurities and coexists with other magnetically ordered states.",2112.06523v1
2022-12-22,Spin wave dispersion of ultra-low damping hematite ($α\text{-Fe}_2\text{O}_3$) at GHz frequencies,"Low magnetic damping and high group velocity of spin waves (SWs) or magnons
are two crucial parameters for functional magnonic devices. Magnonics research
on signal processing and wave-based computation at GHz frequencies focussed on
the artificial ferrimagnetic garnet Y$_3$Fe$_5$O$_{12}$ (YIG) so far. We report
on spin-wave spectroscopy studies performed on the natural mineral hematite
($\alpha\text{-Fe}_2\text{O}_3$) which is a canted antiferromagnet. By means of
broadband GHz spectroscopy and inelastic light scattering, we determine a
damping coefficient of $1.1\times10^{-5}$ and magnon group velocities of a few
10 km/s, respectively, at room temperature. Covering a large regime of wave
vectors up to $k\approx 24~{\rm rad}/\mu$m, we find the exchange stiffness
length to be relatively short and only about 1 \r{A}. In a small magnetic field
of 30 mT, the decay length of SWs is estimated to be 1.1 cm similar to the best
YIG. Still, inelastic light scattering provides surprisingly broad and partly
asymmetric resonance peaks. Their characteristic shape is induced by the large
group velocities, low damping and distribution of incident angles inside the
laser beam. Our results promote hematite as an alternative and sustainable
basis for magnonic devices with fast speeds and low losses based on a stable
natural mineral.",2212.11887v2
2023-03-18,Tunneling magnetoresistance in Mn$_2$Au-based pure antiferromagnetic tunnel junction,"Antiferromagnetic (AF) spintronics is merit on ultra-high operator speed and
stability in the presence of magnetic field. To fully use the merit, the device
should be pure rather than hybrid with ferromagnet or ferrimagnet. For the
magnetism in the antiferromagnet is canceled by that of different sublattices,
breaking the symmetry in the material can revive the native magnetism, which
can be detected by the magnetoresistance (MR) effect. Achieving noticeable MR
effect in the pure AF device is diffcult but essential for the AF spintronic
applications. Here, we study the tunnel magnetoresistance(TMR) effect in the
Nb/Mn$_2$Au/CdO/Mn$_2$Au/Nb pure AF magnetic tunnel junctions (AF-MTJs) based
on a first-principle scattering theory. Giant TMRs with order of 1000% are
predicted in some symmetric junctions, which is originated from the interfacial
resonance tunneling effect related with the k dependent complex band structures
of CdO and Mn$_2$Au in companion with the enhanced spin polarization of the
interfacial magnetic atoms. The effect of voltage bias and interfacial disorder
such as Oxygen vacancy, Manganese vacancy, and Manganese-Cadmium exchanges at
Mn2Au/CdO interfaces are studied also. Our studies suggest
Nb/Mn$_2$Au/CdO/Mn$_2$Au/Nb AFMTJs promising material for AF spintronic
application, and rocksalt CdO a potential symmetry filtering material for
spintronic applications.",2303.10448v1
2023-04-29,Weyl metallic state induced by helical magnetic order,"In the rapidly expanding field of topological materials there is growing
interest in systems whose topological electronic band features can be induced
or controlled by magnetism. Magnetic Weyl semimetals, which contain linear band
crossings near the Fermi level, are of particular interest owing to their
exotic charge and spin transport properties. Up to now, the majority of
magnetic Weyl semimetals have been realized in ferro- or ferrimagnetically
ordered compounds, but a disadvantage of these materials for practical use is
their stray magnetic field which limits the minimum size of devices. Here we
show that Weyl nodes can be induced by a helical spin configuration, in which
the magnetization is fully compensated. Using a combination of neutron
diffraction and resonant elastic x-ray scattering, we find that EuCuAs develops
a planar helical structure below $T_\textrm{N}$ = 14.5 K which induces Weyl
nodes along the $\Gamma$--A high symmetry line in the Brillouin zone.",2305.00295v1
2024-01-10,Laser induced ultrafast Gd 4f spin dynamics at the surface of amorphous CoxGd100-x ferrimagnetic alloys,"We have investigated the laser induced ultrafast dynamics of Gd 4f spins at
the surface of CoxGd100-x alloys by means of surface-sensitive and
time-resolved dichroic resonant Auger spectroscopy. We have observed that the
laser induced quenching of Gd 4f magnetic order at the surface of the
CoxGd100-x alloys occur on a much longer time scale than that previously
reported in bulk sensitive time-resolved experiments. In parallel, we have
characterized the static structural and magnetic properties at the surface and
in the bulk of these alloys by combining Physical Property Measurement System
(PPMS) magnetometry with X-ray Magnetic Circular Dichroism in absorption
spectroscopy (XMCD) and X-Ray Photoelectron spectroscopy (XPS). The PPMS and
XMCD measurements give information regarding the composition in the bulk of the
alloys. The XPS measurements show non-homogeneous composition at the surface of
the alloys with a strongly increased Gd content within the first layers
compared to the nominal bulk values. Such larger Gd concentration results in a
reduced indirect Gd 4f spin-lattice coupling. It explains the slower Gd 4f
demagnetization we have observed in our surface-sensitive and time-resolved
measurements compared to that previously reported by bulk-sensitive
measurements.",2401.05130v3
2000-08-10,Thermal properties of ferrimagnetic systems,"The heat capacity of some ferrimagnets has additional structures like a
shoulder in the Schottky-like peak, or emergence of a second peak when an
external magnetic field is applied. It is shown here that as long as spin
wave-spin wave interactions are ignored in a ferrimagnet, the ferromagnetic and
antiferromagnetic elementary excitation spectra give rise to two independent
heat capacity peaks, one enveloped by the other, which add up to give the peak
for the total system. Taking this into account helps understand the additional
structures in the peaks. Moreover, the classification of ferrimagnets into
predominantly antiferromagnetic, ferromagnetic, or a mixture of the two is
shown to be validated by studying them under additional influences like
dimerization and frustration. Because these two are shown to influence the
ferromagnetic and antiferromagnetic dispersion relations - and hence the
quantities like heat capacity and magnetic susceptibility - by different
amounts, the characterisation of ferrimagnetic systems ($1,1/2$), ($3/2,1$) and
($3/2,1/2$) is brought out more clearly. Both these influences enhance
antiferromagnetic character.",0008167v1
2000-11-22,Collective excitations in ferrimagnetic Heisenberg ladders,"We study ground-state properties and the low-lying excitations of Heisenberg
spin ladders composed of two ferrimagnetic chains with alternating site spins
$(S_1>S_2)$ by using the bosonic Dyson-Maleev formalism and Lanczos numerical
techniques. The emphasis is on properties of the ferrimagnetic phase which is
stable for antiferromagnetic interchain couplings $J_{\perp}\geq 0$. There are
two basic implications of the underlying lattice structure: (i) the spin-wave
excitations form folded acoustic and optical branches in the extended Brillouin
zone and (ii) the ground state parameters (such as the on-site magnetizations
and spin-stiffness constant) show a crossover behavior in the weak-coupling
region $0<J_{\perp}<1$. The above peculiarities of the ladder ferrimagnetic
state are studied up to second order in the quasiparticle interaction and by a
numerical diagonalization of ladders containing up to N=12 rungs. The presented
results for the ground-state parameters and the excitation spectrum can be used
in studies on the low-temperature thermodynamics of ferrimagnetic ladders.",0011388v1
2004-09-11,"Cumulant expansion for ferrimagnetic spin (S_1, s_2) systems","We have generalized the application of cumulant expansion to ferrimagnetic
systems of large spins. We have derived the effective Hamiltonian in terms of
classical variables for a quantum ferrimagnet of large spins. A noninteracting
gas of ferrimagnetic molecules is studied systematically by cumulant expansion
to second order of ($Js/T$) where $J$ is the exchange coupling in each
molecule, $s$ is the smaller spin ($S_1, s_2$) and $T$ is temperature. We have
observed fairly good results in the convergent regime of the expansion, i.e $T
> Js$. We then extend our approach to a system of interacting ferrimagnetic
molecules. For one dimensional nearest neighbor interaction we have observed
that the correlation of more than two neighboring sites is negligible at
moderate and high temperature behavior. Thus the results of a single molecule
can be applied to the chain of interacting molecules for temperatures greater
than classical energy scale, i.e $T>JS_1s_2$. Finally we will discuss the
effect of spin inhomogeneity on the accuracy of this method.",0409293v1
2006-10-24,Ferrimagnetic and Long Period Antiferromagnetic Phases in High Spin Heisenberg Chains with D-Modulation,"The ground state properties of the high spin Heisenberg chains with
alternating single site anisotropy are investigated by means of the numerical
exact daigonaization and DMRG method. It is found that the ferrimagnetic state
appears between the Haldane phase and period doubled N\'eel phase for the
integer spin chains. On the other hand, the transition from the
Tomonaga-Luttinger liquid state into the ferrimagnetic state takes place for
the half-odd-integer spin chains. In the ferrimagnetic phase, the spontaneous
magnetization varies continuously with the modulation amplitude of the single
site anisotropy. Eventually, the magnetization is locked to fractional values
of the saturated magnetization. These fractional values satisfy the
Oshikawa-Yamanaka-Affleck condition. The local spin profile is calculated to
reveal the physical nature of each state. In contrast to the case of
frustration induced ferrimagnetism, no incommensurate magnetic superstructure
is found.",0610660v1
2010-02-24,Magnetic Structure of CaBaCo4O7: Lifting of Geometrical Frustration towards Ferrimagnetism,"CaBaCo4O7 represents a new class of ferrimagnets whose structure is built up
of CoO4 tetrahedra only, similarly to other members LnBaCo4O7 of the 114
series, forming an alternate stacking of kagome and triangular layers. Neutron
powder diffraction reveals, that this compound exhibits the largest distortion
within the 114 series, characterized by a strong buckling of the kagome layers.
Differently from all other members it shows charge ordering, with Co2+ sitting
on two sites (Co2, Co3) and mixed valent cobalt Co3+/Co2+L sitting on two other
sites (Co1, Co4). The unique ferrimagnetic structure of this cobaltite at 4 K
can be described as the assemblage of ferrimagnetic triple chains (Co1 Co2 Co3)
running perpendicular to the kagome layers, ferromagnetically coupled within
the layers, and antiferromagnetically coupled with a fourth cobalt species Co4.
The lifting of the geometrical frustration towards ferrimagnetism, which
appears in spite of the triangular topology of the cobalt lattice, is explained
by the very large structural distortion, charge ordering phenomena and large
cobalt valence compared to other LnBaCo4O7 oxides.",1002.4544v1
2016-07-13,"Breakdown of a Magnetization Plateau in Ferrimagnetic Mixed Spin-(1/2,S) Heisenberg Chains Due to a Quantum Phase Transition Towards the Luttinger Spin Liquid","Magnetization curves of the ferrimagnetic mixed spin-(1/2,S) Heisenberg
chains are calculated with the help of density-matrix renormalization group
method for several quantum spin numbers S=1, 3/2, 2 and 5/2. It is shown that
the ferrimagnetic mixed spin-(1/2,S) Heisenberg chains exhibit irrespective of
the spin value S exactly one intermediate magnetization plateau, which can be
identified with the gapped Lieb-Mattis ferrimagnetic ground state. The
magnetization plateau due to the Lieb-Mattis ferrimagnetism breaks down at a
quantum phase transition towards the Luttinger spin liquid, which is
characterized by a continuous change of the magnetization with the magnetic
field until another quantum critical point is reached at the saturation field.",1607.03617v1
2017-03-24,Anomalous current-induced spin torques in ferrimagnets near compensation,"While current-induced spin-orbit torques (SOTs) have been extensively studied
in ferromagnets and antiferromagnets, ferrimagnets have been less studied. Here
we report the presence of enhanced spin-orbit torques resulting from negative
exchange interaction in ferrimagnets. The effective field and switching
efficiency increase substantially as CoGd approaches its compensation point,
giving rise to 9 times larger spin-orbit torques compared to that of
non-compensated one. The macrospin modelling results also support efficient
spin-orbit torques in a ferrimagnet. Our results suggest that ferrimagnets near
compensation can be a new route for spin-orbit torque applications due to their
high thermal stability and easy current-induced switching assisted by negative
exchange interaction.",1703.08263v1
2016-12-19,Completely compensated ferrimagnetism and sublattice spin crossing in the half-metallic Heusler compound Mn1.5FeV0.5Al,"The Slater-Pauling rule states that L21 Heusler compounds with 24 valence
electrons do never exhibit a total spin magnetic moment. In case of strongly
localized magnetic moments at one of the atoms (here Mn) they will exhibit a
fully compensated half-metallic ferrimagnetic state instead, in particular,
when symmetry does not allow for antiferromagnetic order. With aid of magnetic
and anomalous Hall effect measurements it is experimentally demonstrated that
Mn1.5V0.5FeAl follows such a scenario. The ferrimagnetic state is tuned by the
composition. A small residual magnetization, that arises due to a slight
mismatch of the magnetic moments in the different sublattices results in a
pronounced change of the temperature dependence of the ferrimagnet. A
compensation point is confirmed by observation of magnetic reversal and sign
change of the anomalous Hall effect. Theoretical models are presented that
correlate the electronic structure and the compensation mechanisms of the
different half-metallic ferrimagnetic states in the Mn-V-Fe-Al Heusler system.",1612.06300v1
2018-10-01,Stabilizing Mechanism for Bose-Einstein Condensation of Interacting Magnons in Ferrimagnets and Ferromagnets,"We propose a stabilizing mechanism for the Bose-Einstein condensation (BEC)
of interacting magnons in ferrimagnets and ferromagnets. By studying the
effects of the magnon-magnon interaction on the stability of the magnon BEC in
a ferrimagnet and two ferromagnets, we show that the magnon BEC remains stable
even in the presence of the magnon-magnon interaction in the ferrimagnet and
ferromagnet with a sublattice structure, whereas it becomes unstable in the
ferromagnet without a sublattice structure. This indicates that the existence
of a sublattice structure is the key to stabilizing the BEC of interacting
magnons, and the difference between the spin alignments of a ferrimagnet and a
ferromagnet is irrelevant. Our result can resolve a contradiction between
experiment and theory in the magnon BEC of yttrium iron garnet. Our theoretical
framework may provide a starting point for understanding the physics of the
magnon BEC including the interaction effects.",1810.00584v2
2018-12-03,"Mn2V0.5Co0.5Z (Z= Ga, Al) Heusler alloys: Fully compensated ferrimagnets with high Tc and compensation temperature","High TC fully compensated ferrimagnets are potential candidates for spin
transfer torque based spintronic devices. We report the structural and magnetic
properties of high TC fully compensated ferrimagnets Mn2V0.5Co0.5Z where Z is
Ga, Al, in the melt spun ribbon and arc melted bulk form. While the parent
alloys Mn2YZ where Y is V, Co and Z is Ga, Al exhibits a magnetic moment value
around 2 muB per f.u, the Mn2V0.5Co0.5Ga alloy exhibits room temperature nearly
fully compensated moment value of 0.09 and 0.13 muB per f.u. in the bulk and
ribbon form respectively. For Mn2V0.5Co0.5Al this turned out to be 0.04 and
0.08 muB per f.u. In Contrast to the bulk sample's Neel P type ferrimagnetic
behaviour, ribbon samples exhibit Neel N type ferrimagnetic characteristic with
a high compensation temperature of 420 K for Ga alloy and 275 K for Al alloy.
The observed TC values are more than 640 K for all samples. The differences in
the magnetic properties of arc melted and melt spun alloys indicates that even
a slight variation in stoichiometry and sample preparation method can influence
the physical properties of a compensated system.",1812.00714v1
2023-07-02,"Giant coercivity, resistivity upturn, and anomalous Hall effect in ferrimagnetic FeTb","Despite the blooming interest, the transition-metal rare-earth ferrimagnets
have not been comprehensively understood in terms of their coercivity and
transport properties. Here, we report a systematic study of the magnetic and
transport properties of ferrimagnetic FeTb alloy by varying the layer thickness
and temperature. The FeTb is tuned from the Tb-dominated regime to the
Fe-dominated regime via the layer thickness, without varying the composition.
The coercivity closely follows the $1/\cos\theta_H$ scaling (where $\theta_H$
is the polar angle of the external magnetic field) and increases
quasi-exponentially upon cooling (exceeding 90 kOe at low temperatures),
revealing that the nature of the coercivity is the thermally-assisted domain
wall depinning field. The resistivity exhibits a quasi-linear upturn upon
cooling possibly due to thermal vibrations of the structure factor of the
amorphous alloy. The existing scaling laws of the anomalous Hall effect in the
literature break down for the amorphous FeTb that are either Fe- or
Tb-dominated. These findings should advance the understanding of the
transition-metal-rare-earth ferrimagnets and the associated ferrimagnetic
phenomena in spintronics.",2307.00475v1
2024-02-07,Quantum Theory of Spin-Transfer and Spin-Pumping in Collinear Antiferromagnets and Ferrimagnets,"Antiferromagnets are promising candidates as active components in spintronic
applications. They share features with ferrimagnets in that opposing spin
orientations exist in two or more sublattices. Spin transfer torque and spin
pumping are essential ingredients in antiferromagnetic and ferrimagnet
spintronics. This paper develops an out-of-equilibrium quantum theory of the
spin dynamics of collinear magnets containing many spins coupled to normal
metal reservoirs. At equilibrium, the spins are parallel or antiparallel to the
easy axis. The theory, therefore, covers collinear antiferromagnets and
ferrimagnets. We focus on the resulting semi-classical spin dynamics. The
dissipation in the spin dynamics is enhanced due to spin-pumping. Spin
accumulations in the normal metals induce deterministic spin-transfer torques
on the magnet. Additionally, each electron's discrete spin angular momentum
causes stochastic fluctuating torques on the antiferromagnet or ferrimagnet. We
derive these fluctuating torques. The fluctuation-dissipation theorem holds at
high temperatures, including the effects of spin-pumping. At low temperatures,
we derive shot noise contributions to the fluctuations.",2402.04719v1
1995-09-13,Numerical Study of a Mixed Ising Ferrimagnetic System,"We present a study of a classical ferrimagnetic model on a square lattice in
which the two interpenetrating square sublattices have spins one-half and one.
This model is relevant for understanding bimetallic molecular ferrimagnets that
are currently being synthesized by several experimental groups. We perform
exact ground-state calculations for the model and employ Monte Carlo and
numerical transfer-matrix techniques to obtain the finite-temperature phase
diagram for both the transition and compensation temperatures. When only
nearest-neighbor interactions are included, our nonperturbative results
indicate no compensation point or tricritical point at finite temperature,
which contradicts earlier results obtained with mean-field analysis.",9509076v1
1997-12-01,Spin-wave series for quantum one-dimensional ferrimagnets,"Second-order spin-wave expansions are used to compute the ground-state energy
and sublattice magnetizations of the quantum one-dimensional Heisenberg
ferrimagnet with nearest-neighbor antiferromagnetic interactions and two types
of alternating sublattice spins $S_1>S_2$. It is found that in the extreme
quantum cases $(S_1,S_2)=(1,1/2)$, $(3/2,1)$, and $(3/2,1/2)$, the estimates
for the ground-state energy and sublattice magnetizations differ less than
0.03% for the energy and 0.2% for the sublattice magnetizations from the
recently published density matrix renormalization group numerical calculations.
  The reported results strongly suggest that the quantum Heisenberg
ferrimagnetic chains give another example of a low-dimensional quantum spin
system where the spin-wave approach demonstrates a surprising efficiency.",9712014v1
1999-10-07,Phase diagram of ferrimagnetic ladders with bond-alternation,"We study the phase diagram of a 2-leg bond-alternation spin-(1/2, 1) ladder
for two different configurations using a quantum renormalization group
approach. Although d-dimensional ferrimagnets show gapless behavior, we will
explicitly show that the effect of the spin mixing and the bond-alternation can
open the possibility for observing an energy gap. We show that the gapless
phases of such systems can be equivalent to the 1-dimensional half-integer
antiferroamgnets, besides the gapless ferrimagnetic phases. We therefore
propose a phase transition between these two gapless phases that can be seen in
the parameter space.",9910103v1
2000-01-31,Magnon dispersions in quantum Heisenberg ferrimagnetic chains at zero temperature,"Within the Dyson-Maleev boson formalism, we study the zero-temperature magnon
dispersions in a family of one-dimensional quantum Heisenberg ferrimagnets
composed of two different spins $(S_1,S_2)$ in the elementary cell. It is shown
that the spin-wave theory can produce precise quantitative results for the
low-energy excitations. The spin-stiffness constant $\rho_s$ and the optical
magnon gap $\Delta$ of different $(S_1,S_2)$ ferrimagnetic systems are
calculated, respectively, to second and third order in the quasiparticle
interaction. The spin-wave results are compared with available numerical
estimates.",0001441v1
2000-07-26,First- and second-order transitions of the escape rate in ferrimagnetic or antiferromagnetic particles,"Quantum-classical escape-rate transition has been studied for two general
forms of magnetic anisotropy in ferrimagnetic or antiferromagnetic particles.
It is found that the range of the first-order transition is greatly reduced as
the system becomes ferrimagnetic and there is no first-order transition in
almost compensated antiferromagnetic particles. These features can be tested
experimentally in nanomagnets like molecular magnets.",0007406v1
2005-12-24,Modified spin-wave theory of nuclear magnetic relaxation in one-dimensional quantum ferrimagnets: Three-magnon versus Raman processes,"Nuclear spin-lattice relaxation in one-dimensional Heisenberg ferrimagnets is
studied by means of a modified spin-wave theory. Calculating beyond the
first-order mechanism, where a nuclear spin directly interacts with spin waves
through the hyperfine coupling, we demonstrate that the
exchange-scattering-enhanced three-magnon nuclear relaxation may generally
predominate over the Raman one with increasing temperature and decreasing
field. Recent proton spin-lattice relaxation-time (T_1_) measurements on the
ferrimagnetic chain compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O suggest
that the major contribution to 1/T_1_ be made by the three-magnon scattering.",0512629v1
2006-07-25,Quantum Hall Ferrimagnetism in lateral quantum dot molecules,"We demonstrate the existance of ferrimagnetic and ferromagnetic phases in a
spin phase diagram of coupled lateral quantum dot molecules in the quantum Hall
regime. The spin phase diagram is determined from Hartree-Fock Configuration
Interaction method as a function of electron numbers N, magnetic field B,
Zeeman energy, and tunneling barrier height. The quantum Hall ferrimagnetic
phase corresponds to spatially imbalanced spin droplets resulting from strong
inter-dot coupling of identical dots. The quantum Hall ferromagnetic phases
correspond to ferromagnetic coupling of spin polarization at filling factors
between $\nu=2$ and $\nu=1$.",0607638v1
1995-07-19,On behaviour of critical lines near ferrimagnetic phase in Higgs-Yukawa systems,"We calculate within a mean-field approximation the slopes of the critical
lines near the point of appearing the ferrimagnetic phase for the U(1) systems
in the weak coupling regime. It is demonstrated that the slope of one of the
critical line is continuous, while change of the slope of the other depends
strongly on the number of the fermion flavours. We also find that in the
ferrimagnetic phase near such a point the magnetization and the staggered
magnetization align orthogonally to each other.",9507019v1
2006-04-13,Thermal Entanglement in Ferrimagnetic Chains,"A formula to evaluate the entanglement in an one-dimensional ferrimagnetic
system is derived. Based on the formula, we find that the thermal entanglement
in a small size spin-1/2 and spin-s ferrimagnetic chain is rather robust
against temperature, and the threshold temperature may be arbitrarily high when
s is sufficiently large. This intriguing result answers unambiguously a
fundamental question: ``can entanglement and quantum behavior in physical
systems survive at arbitrary high temperatures?""",0604099v1
2008-08-28,Magnetoelectric coupling in the cubic ferrimagnet Cu2OSeO3,"We have investigated the magnetoelectric coupling in the lone pair containing
piezoelectric ferrimagnet Cu2OSeO3. Significant magnetocapacitance develops in
the magnetically ordered state (TC = 60 K). We find critical behavior near TC
and a divergence near the metamagnetic transition at 500 Oe. High-resolution
X-ray and neutron powder diffraction measurements show that Cu2OSeO3 is
metrically cubic down to 10 K but that the ferrimagnetic ordering reduces the
symmetry to rhombohedral R3. The metric cubic lattice dimensions exclude a
magnetoelectric coupling mechanism involving spontaneous lattice strain, and
this is unique among magnetoelectric and multiferroic materials.",0808.3955v1
2008-10-22,"Study of the mixed Ising spins (1/2,3/2) in a random crystal field","We study the magnetic properties of a mixed Ising ferrimagnetic system, in
which the two interacting sublattices have spins $\sigma$, $(\pm 1/2)$ and
spins $S$, $(\pm 3/2,\pm 1/2)$ in the presence of a random crystal field, with
the mean field approach. The obtained results show the existence of some
interesting phenomena, such as the appearance of a new ferrimagnetic phase
namely the partly ferrimagnetic phase $(m_{\sigma}=\frac{-1}{2},m_S=+1)$ and
consequently the existence of three topologically different types of phase
diagrams. The effect of increasing the exchange interaction parameter $J$, at
very low temperature is investigated. The transitions shown in these phase
diagrams are in good agreement with those obtained in the ground state case.",0810.4128v1
2010-04-26,Andreev reflection in ferrimagnetic CoFe2O4/SrRuO3 spin filters,"We have performed point contact spectroscopy measurements on a sample
constituted by a metallic ferromagnetic oxide (SrRuO_3) bottom electrode and a
tunnel ferrimagnetic (CoFe_2O_4) barrier. Andreev reflection is observed across
the tunnel barrier. From the comparison of Andreev reflection in SrRuO3 and
across the CoFe_2O_4 barrier we infer that the ferrimagnetic barrier has a spin
filter efficiency not larger than +13%. The observation of a moderate and
positive spin filtering is discussed in the context of the microstructure of
the barriers and symmetry-related spin filtering effects.",1004.4631v1
2011-04-20,Magnetic properties of the ferrimagnetic cobaltite CaBaCo4O7,"The magnetic properties of the ferrimagnetic cobaltite CaBaCo$_4$O$_7$ are
systematically investigated. We find that the susceptibility exhibits a
downward deviation below $\sim$ 360 K, suggesting the occurrence of short range
magnetic correlations at temperature well above $T_C$. The effective moment is
determined to be 4.5 $\mu_B$/f.u, which is consistent with that expected for
the Co$^{2+}$/Co$^{3+}$ high spin species. Using a criterion given by Banerjee
[Phys. Lett. \textbf{12}, 16 (1964)], we demonstrate that the paramagnetic to
ferrimagnetic transition in CaBaCo$_4$O$_7$ has a first order character.",1104.4032v1
2012-07-17,Ultrafast dynamical path for the switching of a ferrimagnet after femtosecond heating,"Ultrafast laser-induced magnetic switching in rare earth, transition metal
ferrimagnetic alloys has recently been reported to occur by ultrafast heating
alone. Using atomistic simulations and a ferrimagnetic Landau-Lifshitz-Bloch
formalism, we demonstrate that for switching to occur it is necessary that
angular momentum is transferred from the longitudinal to transverse
magnetization components. This dynamical path leads to magnetization switching
and subsequent ultrafast precession caused by the inter-sublattice exchange
field on the nanoscale.",1207.4092v2
2012-10-24,Dirac half-metal in a triangular ferrimagnet,"An idea is proposed for realizing a fully spin-polarized Dirac semimetal in
frustrated itinerant magnets. We show that itinerant electrons on a triangular
lattice exhibit the Dirac cone dispersion with half-metallic behavior in the
presence of a three-sublattice ferrimagnetic order. The Dirac nodes have the
same structure as those of graphene. By variational calculation and Monte Carlo
simulation, we demonstrate that the ferrimagnetic order with the Dirac node
spontaneously emerges in a simple Kondo lattice model with Ising anisotropy.
The realization will be beneficial for spintronics as a candidate for
spin-current generator.",1210.6700v1
2012-12-25,Magnetization process in the exactly solved spin-1/2 Ising-Heisenberg model on decorated Bethe lattices,"The spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices
is exactly solved in the presence of the longitudinal magnetic field by
combining the decoration-iteration mapping transformation with the method of
exact recursion relations. In particular, the ground state and low-temperature
magnetization process of the ferrimagnetic version of the considered model is
investigated in detail. Three different magnetization scenarios with up to two
consecutive fractional magnetization plateaus were found, whereas the
intermediate magnetization plateau may either correspond to the classical
ferrimagnetic spin arrangement and/or the field-induced quantum ferrimagnetic
spin ordering without any classical counterpart.",1212.6032v1
2016-02-06,Lieb-Mattis ferrimagnetism in diluted magnetic semiconductors,"We show the possibility of long-range ferrimagnetic ordering with a
saturation magnetisation of the order of 1 Bohr magneton per spin for
arbitrarily low concentration of magnetic impurities in semiconductors,
provided that the impurities form a superstructure satisfying the conditions of
the Lieb-Mattis theorem. Explicit examples of such superstructures are given
for the wurtzite lattice, and the temperature of ferrimagnetic transition is
estimated from a high-temperature expansion. Exact diagonalization studies show
that small fragments of the structure exhibit enhanced magnetic response and
isotropic superparamagnetism at low temperatures. A quantum transition in a
high magnetic field is considered and similar superstructures in cubic
semiconductors are discussed as well.",1602.02239v1
2019-05-29,Spin wave propagation in ferrimagnetic $Gd_{x}Co_{1-x}$,"Recent advances in antiferromagnetic spin dynamics using rare-earth (RE) and
transition-metal (TM) ferrimagnets have attracted much interest for spintronic
devices with a high speed and density. In this study, the spin wave properties
in the magnetostatic backward volume mode and surface mode in RE-TM
ferrimagnetic $Gd_{x}Co_{1-x}$ films with various composition x are
investigated using spin wave spectroscopy. The obtained group velocity and
attenuation length are well explained by the ferromagnet-based spin wave theory
when the composition of $Gd_{x}Co_{1-x}$ is far from the compensation point.",1905.12771v1
2011-11-15,Frustration-Induced Ferrimagnetism in Heisenberg Spin Chains,"We study ground-state properties of the Heisenberg frustrated spin chain with
interactions up to fourth nearest neighbors by the exact-diagonalization method
and the density matrix renormalization group method. We find that
ferrimagnetism is realized not only in the case of S=1/2 but also S=1 despite
that there is only a single spin site in each unit cell determined from the
shape of the Hamiltonian. Our numerical results suggest that a
""multi-sublattice structure"" is not required for the occurrence of
ferrimagnetism in quantum spin systems with isotropic interactions.",1111.3430v1
2021-01-18,Quantum fluctuation effects on the ordered Moments in a two dimensional frustrated ferrimagnet,"We propose a novel two-dimensional (2D)frustrated quantum spin-1/2
anisotropic Heisenberg model with alternating ferromagnetic and
antiferromagnetic magnetic chains along one direction and antiferromagnetic
interactions along the other. The (mean-field) ground state is ferrimagnetic in
certain range of the interaction space. Spin-wave theory analysis of the
reduction of ordered moments at inequivalent spin sites and the instability of
the spin waves suggest a quantum phase transition which has the characteristics
of both the frustrated two-dimensional antiferromagnetic S=1/2 ($J_1, J_2$)
model and 1D S$_1$=1, S$_2$=1/2 quantum ferrimagnetic model.",2101.07300v1
2019-08-19,Amorphous Ferrimagnets: an Ideal Host for Ultra-Small Skyrmions at Room Temperature,"Recently, magnetic skyrmion has emerged as an active topic of fundamental
study and applications in magnetic materials research. Magnetic skyrmions are
vortex-like spin excitations with topological protection and therefore are more
robust to pinning compared with magnetic domain walls. We employ atomistic
simulations to create room-temperature ultra-small Neel skyrmions in amorphous
ferrimagnet. The fast propagation and low-dissipation dynamics of ultra-small
ferrimagnetic skyrmions make them attractive for utilization as an alternative
to domain walls in spin-based memory and logic devices.",1908.07003v2
2022-07-30,On field-driven domain wall motion in compensated ferrimagnetic nanowires,"The fascinating high-speed field-driven domain wall (DW) motion along
ferrimagnetic nanowires near the angular momentum compensation point (AMCP) is
solved based on the generic ferrimagnetic dynamics. The physics of the absences
of precessional torque and infinite high Walker breakdown field at the AMCP is
proved under general conditions. Based on the energy conservation principle, an
almost exact DW velocity formula, valid beyond the Walker breakdown field, is
obtained. Our results agree with all existing experiments and simulations. This
theory provides useful guidances to DW manipulation.",2208.00179v1
2023-07-28,Analysis of magneto-optical Kerr spectra of ferrimagnetic Mn$_4$N,"Simulations of magneto-optical Kerr effect in biaxially strained Mn$_4$N are
performed using density functional theory and linear response theory. We
consider three ferrimagnetic phases, two collinear and one noncollinear, which
have been corroborated separately by earlier studies. The simulated spectra are
compared to magneto-optical data available in recent literature. A collinear
ferrimagnetic phase with a small saturation magentization, a large
perpendicular anisotropy, and Curie temperature above 700~K is found to be
consistent with the measured spectra. We hypothesise that an admixture of the
noncollinear phase, which could explain the lower than predicted net moment and
magnetic anisotropy observed experimentally, is also present.",2307.15246v1
2001-05-05,"Spin, charge and orbital ordering in ferrimagnetic insulator YBaMn$_2$O$_5$","The oxygen-deficient (double) perovskite YBaMn$_2$O$_5$, containing
corner-linked MnO$_5$ square pyramids, is found to exhibit ferrimagnetic
ordering in its ground state. In the present work we report
generalized-gradient-corrected, relativistic first-principles full-potential
density-functional calculations performed on YBaMn$_2$O$_5$ in the nonmagnetic,
ferromagnetic and ferrimagnetic states. The charge, orbital and spin orderings
are explained with site-, angular momentum- and orbital-projected density of
states, charge-density plots, electronic structure and total energy studies.
YBaMn$_2$O$_5$ is found to stabilize in a G-type ferrimagnetic state in
accordance with experimental results. The experimentally observed insulating
behavior appears only when we include ferrimagnetic ordering in our
calculation. We observed significant optical anisotropy in this material
originating from the combined effect of ferrimagnetic ordering and crystal
field splitting. In order to gain knowledge about the presence of different
valence states for Mn in YBaMn$_2$O$_5$ we have calculated $K$-edge x-ray
absorption near-edge spectra for the Mn and O atoms. The presence of the
different valence states for Mn is clearly established from the x-ray
absorption near-edge spectra, hyperfine field parameters and the magnetic
properties study. Among the experimentally proposed structures, the recently
reported description based on $P$4/$nmm$ is found to represent the stable
structure.",0105117v1
2020-01-22,The dynamics of a domain wall in ferrimagnets driven by spin-transfer torque,"The spin-transfer-torque-driven (STT-driven) dynamics of a domain wall in an
easy-axis rare-earth transition-metal ferrimagnet is investigated theoretically
and numerically in the vicinity of the angular momentum compensation point
$T_A$, where the net spin density vanishes. The particular focus is given on
the unusual interaction of the antiferromagnetic dynamics of a ferrimagnetic
domain wall and the adiabatic component of STT, which is absent in
antiferromagnets but exists in the ferrimagnets due to the dominant coupling of
conduction electrons to transition-metal spins. Specifically, we first show
that the STT-induced domain-wall velocity changes its sign across $T_A$ due to
the sign change of the net spin density, giving rise to a phenomenon unique to
ferrimagnets that can be used to characterize $T_A$ electrically. It is also
shown that the frequency of the STT-induced domain-wall precession exhibits its
maximum at $T_A$ and it can approach the spin-wave gap at sufficiently high
currents. Lastly, we report a numerical observation that, as the current
density increases, the domain-wall velocity starts to deviate from the
linear-response result, calling for a more comprehensive theory for the
domain-wall dynamics in ferrimagnets driven by a strong current.",2001.08037v1
2020-04-23,Temperature-dependent Magnetic Transitions in CoCrPt-Ru-CoCrPt Synthetic Ferrimagnets,"The magnetic orientations and switching fields of a CoCrPt-Ru-CoCrPt
synthetic ferrimagnet with perpendicular magnetic anisotropy have been studied
in the temperature range from 2 K to 300 K. It was found that two sets of
magnetic transitions occur in the CoCrPt-Ru-CoCrPt ferrimagnet across this
temperature range. The first set exhibits three magnetic transitions in the 50
K - 370 K range, whereas the second involves only two transitions in the 2 K
and 50 K range. The observed magnetic hysteresis curves of the synthetic
ferrimagnet are explained using the energy diagram technique framework
pioneered by Koplak et al. [1] which accurately describes the competition
between interlayer exchange coupling energy, Zeeman energy, and anisotropy
energy in the system. In this work we expand the framework to include synthetic
ferrimagnets (SFMs) comprising higher perpendicular magnetic anisotropy
materials and large (4X) interlayer exchange coupling energies which are
promising for the development of ultrafast (ps) magnetic switching free layers
in MTJ structures. Furthermore, we apply the analysis to predict SFM magnetic
hysteresis curves in a temperature regime that includes temperature extrema
that a synthetic ferrimagnet would be expected to reliably operate at, were it
to be utilized as a free layer in a memory or sensor spintronic device.",2004.11406v2
2003-01-30,"The Mixed Spin S=(1/2,1) XXZ Ferrimagnet at Zero Temperature","Linked cluster series expansions about the Ising limit are used to study
ground state preperties, viz. ground state energy, magnetization and excitation
spectra, for mixed spin S=(1/2,1) quantum ferrimagnets on simple bipartite
lattices in 1, 2, and 3-dimensions. Results are compared to second-order spin
wave theory and, in general, excellent agreement is obtained.",0301580v1
2003-09-30,Recent Progress of the Low-Dimensional Spin-Wave Theory,"A modified spin-wave theory is developed and applied to low-dimensional
quantum magnets. Double-peaked specific heat for one-dimensional ferrimagnets,
nuclear spin-lattice relaxation in ferrimagnetic chains and clusters, and
thermal behavior of Haldane-gap antiferromagnets are described within the
scheme. Mentioning other bosonic and fermionic representations as well, we
demonstrate that spin waves are still effective in low dimensions.",0310004v1
2004-12-15,Nuclear Magnetic Relaxation in the Ferrimagnetic Chain Compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O: Three-Magnon Scattering?,"Recent proton spin-lattice relaxation-time (T_1_) measurements on the
ferrimagnetic chain compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O are
explained by an elaborately modified spin-wave theory. We give a strong
evidence of the major contribution to 1/T_1_ being made by the three-magnon
scattering rather than the Raman one.",0412389v1
2005-03-02,Quasi-One-Dimensional Quantum Ferrimagnets,"We present an exact diagonalization study of the half-filled Hubbard model on
bipartite quasi-one-dimensional lattices. In particular, we emphasize the
dependence of the ferrimagnetic ground state properties, and its associated
magnetic excitations, on the Coulomb repulsion U.",0503058v1
2010-06-29,Magnetostatics of synthetic ferrimagnet elements,"We calculate the magnetostatic energy of synthetic ferrimagnet (SyF)
elements, consisting of two thin ferromagnetic layers coupled
antiferromagnetically through RKKY coupling. We calculate exact formulas as
well as approximate yet accurate ones, which can be used to easily derive
energy barriers and anisotropy fields of SyF. These can be used to evaluate
coercivity, thermal stability and other useful quantities.",1006.5531v2
2012-08-31,Magnetic symmetry of the plain domain walls in ferro- and ferrimagnets,"Magnetic symmetry of all possible plane domain walls in ferro- and
ferrimagnets is considered. Magnetic symmetry classes of non 180 degree
(including 0 degree) domain walls are obtained. The domain walls degeneracy is
investigated. The symmetry classification is applied for research of all
possible plane domain walls in crystals of the hexoctahedral crystallographic
class.",1209.0003v1
2018-04-16,Unidirectional Loop Metamaterials (ULM) as Magnetless Artificial Ferrimagnetic Materials: Principles and Applications,"This paper presents an overview of Unidirectional Loop Metamaterial (ULM)
structures and applications. Mimicking electron spin precession in ferrites
using loops with unidirectional loads (typically transistors), the ULM exhibits
all the fundamental properties of ferrite materials, and represents the only
existing magnetless ferrimagnetic medium. We present here an extended
explanation of ULM physics and unified description of its component and system
applications.",1804.08719v1
1998-07-27,Magnetic Properties of a Quantum Ferrimagnet: NiCu(pba)(D_2O)_3 . 2D_2O,"We report the results of magnetic measurements on a powder sample of
NiCu(pba)(D_2O)_3 \cdot 2D_2O$ (pba=1,3-propylenebis(oxamato)) which is one of
the prototypical examples of an $S$=1/2 and 1 ferrimagnetic chain.
Susceptibility($\chi$) shows a monotonous increase with decreasing temperature
(T) and reaches a maximum at about 7 K. In the plot of $\chi T$ versus $T$, the
experimental data exhibit a broad minimum and are fit to the $\chi T$ curve
calculated for the ferrimagnetic Heisenberg chain composed of S=1/2 and 1. From
this fit, we have evaluated the nearest-neighbor exchange constant $J/k_B=121
K$, the g-values of Ni$^{2+}$ and Cu$^{2+}$, $g_{Ni}$=2.22 and $g_{Cu}$=2.09,
respectively. Applied external field dependence of $\chi T$ at low temperatures
is reproduced fairly well by the calculation for the same ferrimagnetic model.",9807348v1
2000-01-01,Characterization of ferrimagnetic Heisenberg chains according to the constituent spins,"The low-energy structure and the thermodynamic properties of ferrimagnetic
Heisenberg chains of alternating spins $S$ and $s$ are investigated by the use
of numerical tools as well as the spin-wave theory. The elementary excitations
are calculated through an efficient quantum Monte Carlo technique featuring
imaginary-time correlation functions and are characterized in terms of
interacting spin waves. The thermal behavior is analyzed with particular
emphasis on its ferromagnetic and antiferromagnetic dual aspect. The extensive
numerical and analytic calculations lead to the classification of the
one-dimensional ferrimagnetic behavior according to the constituent spins: the
ferromagnetic ($S>2s$), antiferromagnetic ($S<2s$), and balanced ($S=2s$)
ferrimagnetism.",0001004v1
2001-02-22,Low-Temperature Properties of Quasi-One-Dimensional Molecule-Based Ferromagnets,"Quantum and thermal behaviors of low-dimensional mixed-spin systems are
investigated with particular emphasis on the design of molecule-based
ferromagnets. One can obtain a molecular ferromagnet by assembling molecular
bricks so as to construct a low-dimensional system with a magnetic ground state
and then coupling the chains or the layers again in a ferromagnetic fashion.
Two of thus-constructed quasi-one-dimensional bimetallic compounds are
qualitatively viewed within the spin-wave treatment, one of which successfully
grows into a bulk magnet, while the other of which ends in a singlet ground
state. Then, concentrating on the ferrimagnetic arrangement on a two-leg ladder
which is well indicative of general coupled-chain ferrimagnets, we develop the
spin-wave theory and fully reveal its low-energy structure. We inquire further
into the ferromagnetic aspect of the ferrimagnetic ladder numerically
calculating the sublattice magnetization and the magnetic susceptibility. There
exists a moderate coupling strength between the chains in order to obtain the
most ferromagnetic ferrimagnet.",0102417v2
2004-01-24,Bosonic representation of one-dimensional Heisenberg ferrimagnets,"The energy structure and the thermodynamics of ferrimagnetic Heisenberg
chains of alternating spins S and s are described in terms of the Schwinger
bosons and modified spin waves. In the Schwinger representation, we average the
local constraints on the bosons and diagonalize the Hamiltonian at the
Hartree-Fock level. In the Holstein-Primakoff representation, we optimize the
free energy in two different ways introducing an additional constraint on the
staggered magnetization. A new modified spin-wave scheme, which employs a
Lagrange multiplier keeping the native energy structure free from temperature
and thus differs from the original Takahashi Scheme, is particularly stressed
as an excellent language to interpret one-dimensional quantum ferrimagnetism.
Other types of one-dimensional ferrimagnets and the antiferromagnetic limit S=s
are also mentioned.",0401476v1
2006-08-26,Ferrimagnetic States in S=1/2 Frustrated Heisenberg Chains with Period 3 Exchange Modulation,"Ground state properties of the S=1/2 frustrated Heisenberg chain with period
3 exchange modulation are investigated using the numerical diagonalization and
DMRG method. It is known that this model has a magnetization plateau at 1/3 of
the saturation magnetization M_s. On the other hand, the ground state is
ferrimagnetic even in the absence of frustration if one of the nearest
neighbour bond is ferromagnetic and others are antiferromagnetic. In the
present work, we show that this ferrimagnetic state continues to the region in
which all bonds are antiferromagnetic if frustration is strong. This state
further continues to the above mentioned 1/3-plateau state. In between, we also
find the noncollinear ferrimagnetic phase in which the spontaneous
magnetization is finite but less than M_s/3. The intuitive interpretation for
the phase diagram is given and the physical properties of these phases are
discussed.",0608582v1
2011-01-19,Mott transition and ferrimagnetism in the Hubbard model on the anisotropic kagomé lattice,"Mott transition and ferrimagnetism are studied in the Hubbard model on the
anisotropic kagom\'e lattice using the variational cluster approximation and
the phase diagram at zero temperature and half-filling is analyzed. The
ferrimagnetic phase rapidly grows as the geometric frustration is relaxed, and
the Mott insulator phase disappears in moderately frustrated region, showing
that the ferrimagnetic fluctuations stemming from the relaxation of the
geometric frustration is enhanced by the electron correlations. In metallic
phase, heavy fermion behavior is observed and mass enhancement factor is
computed. Enhancement of effective spatial anisotropy by the electron
correlations is also confirmed in moderately frustrated region, and its effect
on heavy fermion behavior is examined.",1101.3645v3
2013-10-18,Ultrafast thermally induced magnetic switching in synthetic ferrimagnets,"Synthetic ferrimagnets are composite magnetic structures formed from two or
more anti- ferromagnetically coupled magnetic sublattices with different
magnetic moments. Here we report on atomistic spin simulations of the
laser-induced magnetization dynamics on such synthetic ferrimag- nets, and
demonstrate that the application of ultrashort laser pulses leads to
sub-picoscond magnetization dynamics and all-optical switching in a similar
manner as in ferrimagnetic alloys. Moreover, we present the essential material
properties for successful laser-induced switching, demonstrating the
feasibility of using a synthetic ferrimagnet as a high density magnetic storage
element without the need of a write field.",1310.5170v2
2014-09-30,Predicting a Ferrimagnetic Phase of Zn2FeOsO6 with Strong Magnetoelectric Coupling,"Multiferroic materials, in which ferroelectric and magnetic ordering coexist,
are of fundamental interest for the development of novel memory devices that
allow for electrical writing and non-destructive magnetic readout operation.
The great challenge is to create room temperature multiferroic materials with
strongly coupled ferroelectric and ferromagnetic (or ferrimagnetic) orderings.
BiFeO3 has been the most heavily investigated single-phase multiferroic to date
due to the coexistence of its magnetic order and ferroelectric order at room
temperature. However, there is no net magnetic moment in the cycloidal
(antiferromagnetic-like) magnetic state of bulk BiFeO3, which severely limits
its realistic applications in electric field controlled spintronic devices.
Here, we predict that double perovskite Zn2FeOsO6 is a new multiferroic with
properties superior to BiFeO3. First, there are strong ferroelectricity and
strong ferrimagnetism at room temperature in Zn2FeOsO6. Second, the easy-plane
of the spontaneous magnetization can be switched by an external electric field,
evidencing the strong magnetoelectric coupling existing in this system. Our
results suggest that ferrimagnetic 3d-5d double perovskite may therefore be
used to achieve voltage control of magnetism in future spintronic devices.",1409.8430v2
2017-02-08,Self-Focusing Skyrmion Racetracks in Ferrimagnets,"We theoretically study the dynamics of ferrimagnetic skyrmions in
inhomogeneous metallic films close to the angular momentum compensation point.
In particular, it is shown that the line of the vanishing angular momentum can
be utilized as a self-focusing racetrack for skyrmions. To that end, we begin
by deriving the equations of motion for the dynamics of collinear ferrimagnets
in the presence of a charge current. The obtained equations of motion reduce to
those of ferromagnets and antiferromagnets at two special limits. In the
collective coordinate approach, a skyrmion behaves as a massive charged
particle moving in a viscous medium subjected to a magnetic field. Analogous to
the snake orbits of electrons in a nonuniform magnetic field, we show that a
ferrimagnet with the nonuniform angular momentum density can exhibit snake
trajectories of skyrmions, which can be utilized as racetracks for skyrmions.",1702.02554v1
2018-11-13,X-ray magnetic linear dichroism as a probe for non-collinear magnetic state in ferrimagnetic single layer exchange bias systems,"Ferrimagnetic alloys are extensively studied for their unique magnetic
properties leading to possible applications in perpendicular magnetic
recording, due to their deterministic ultrafast switching and heat assisted
magnetic recording capabilities. On a prototype ferrimagnetic alloy we
demonstrate fascinating properties that occur close to a critical temperature
where the magnetization is vanishing, just as in an antiferromagnet. From the
X-ray magnetic circular dichroism measurements, an anomalous 'wing shape'
hysteresis loop is observed slightly above the compensation temperature. This
bears the characteristics of an intrinsic exchange bias effect, referred to as
atomic exchange bias. We further exploit the X-ray magnetic linear dichroism
(XMLD) contrast for probing non-collinear states which allows us to
discriminate between two main reversal mechanisms, namely perpendicular domain
wall formation versus spin-flop transition. Ultimately, we analyze the
elemental magnetic moments for the surface and the bulk parts, separately,
which allows to identify in the phase diagram the temperature window where this
effect takes place. Moreover, we suggests that this effect is a general
phenomenon in ferrimagnetic thin films which may also contribue to the
understanding of the mechanism behind the all optical switching effect.",1811.05362v1
2020-07-22,Nuclear Magnetic Relaxation Time near Compensation Temperature in Ferrimagnetic Insulator,"The nuclear magnetic relaxation time $T_1$ in ferrimagnetic insulators is
calculated by a Raman process of hyperfine interaction with a meanfield
approximation. It is found that the 1/$T_1$ on one site rapidly increases near
the compensation temperature $T_0$, whereas that on another site does not
increase up to Curie temperature $T_c$. This is due to that the band width of
soft magnon becomes comparable to $T_0$. The increasing behavior of 1/$T_1$
below $T_c$ is found also in another type ferrimagnet, which shows hump
structure in the temperature dependence of magnetization instead of
compensation. Also in this case, we find the rapid increase of 1/$T_1$ below
$T_c$, even though the magnetization does not show the compensation. Such a
coexistence of soft and hard magnons will lead to remarkable properties of
ferrimagnet.",2007.11214v3
2010-05-04,Competition between Ferrimagnetism and Magnetic Frustration in Zinc Substituted YBaFe4O7,"The substitution of zinc for iron in YBaFe4O7 has allowed the oxide series
YBaFe4-xZnxO7, with 0.40 < x < 1.50, belonging to the ""114"" structural family
to be synthesized. These oxides crystallize in the hexagonal symmetry (P63mc),
as opposed to the cubic symmetry (F-43m) of YBaFe4O7. Importantly, the d.c.
magnetization shows that the zinc substitution induces ferrimagnetism, in
contrast to the spin glass behaviour of YBaFe4O7. Moreover, a.c. susceptibility
measurements demonstrate that concomitantly these oxides exhibit a spin glass
or a cluster glass behaviour, which increases at the expense of ferrimagnetism,
as the zinc content is increased. This competition between ferrimagnetism and
magnetic frustration is interpreted in terms of lifting of the geometric
frustration, inducing the magnetic ordering, and of cationic disordering, which
favours the glassy state.",1005.0480v1
2017-06-02,Coherent Terahertz Spin-Wave Emission Associated with Ferrimagnetic Domain Wall Dynamics,"We theoretically study the dynamics of ferrimagnetic domain walls in the
presence of Dzyaloshinskii-Moriya interaction. We find that an application of a
DC magnetic field can induce terahertz spin-wave emission by driving
ferrimagnetic domain walls, which is not possible for ferromagnetic or
antiferromagnetic domain walls. Dzyaloshinskii-Moriya interaction is shown to
facilitate the teraherz spin-wave emission in wide ranges of net angular
momentum by increasing the Walkerbreakdown field. Moreover, we show that
spin-orbit torque combined with Dzyaloshinskii-Moriya interaction also drives a
fast ferrimagnetic domain wall motion with emitting terahertz spin-waves in
wide ranges of net angular momentum.",1706.00549v1
2019-07-18,Electric bias-controlled switching of magnetization of ferrimagnetically coupled Mn delta-layers in a GaAs-AlGaAs quantum well,"We suggest a model of synthetic ferrimagnetic semiconductor structure based
on GaAs-AlGaAs quantum well doped by two Mn delta-layers. The coupling between
the delta-layers is mediated by extra holes, and can be switched between ferro-
and antiferromagnetic one by gating the structure. A proper choice of Mn
concentrations in the delta-layers and of local degree of disorder enables
fabrication of a ferrimagnetic structure supporting ultrafast switching of
magnetization by short pulses of electric bias without an external magnetic
field. The switching mechanism in the structure relies on kinetic spin exchange
between the two delta-layers which is mediated by exchange scattering of
electric-pulse heated holes by magnetic ions within the layers. Owing to
specific interplay between characteristics of the exchange scattering, spin
decay times, and the heat withdraw in the suggested synthetic ferrimagnetic
semiconductor, the necessary parameters of electric-bias pulse are within the
technologically accessible range, and do not contradict typical thermal
kinetics of semiconductor structures.",1907.07997v2
2019-09-25,Stability and Absence of a Tower of States in Ferrimagnets,"Antiferromagnets and ferromagnets are archetypes of the two distinct (type-A
and type-B) ways of spontaneously breaking a continuous symmetry. Although
type-B Nambu--Goldstone modes arise in various systems, the ferromagnet was
considered pathological due to the stability and symmetry-breaking nature of
its exact ground state. However, here we show that symmetry-breaking in
ferrimagnets closely resembles the ferromagnet. In particular, there is an
extensive ground state degeneracy, there is no Anderson tower of states, and
the maximally polarized ground state is thermodynamically stable. Our results
are derived analytically for the Lieb--Mattis ferrimagnet and numerically for
the Heisenberg ferrimagnet. We argue that these properties are generic for
type-B symmetry-broken systems, where the order parameter operator is a
symmetry generator.",1909.11381v1
2019-10-03,Current driven domain wall dynamics in ferrimagnetic strips explained by means of a two interacting sublattices model,"The current-driven domain wall dynamics along ferrimagnetic systems are here
theoretically analyzed as a function of the temperature by means of
micromagnetic simulations and a one dimensional model. Contrarily to
conventional effective approaches, our model takes into account the two coupled
ferromagnetic sublattices forming the ferrimagnetic system. Although the model
is suitable for systems with asymmetric exchange interaction and spin-orbit
coupling effects due to adjacent heavy metal layers, we here focus our
attention on the case of single-layer ferrimagnetic strips where domain walls
adopt achiral Bloch configurations at rest. Such domain walls can be driven by
either out-of-plane fields or spin transfer torques upon bulk current
injection. Our results indicate that the domain wall velocity is optimized at
the angular compensation temperature for both field-driven and current-driven
cases. Our advanced models allow us to infer that the precession of the
internal domain wall moments is suppressed at such compensation temperature,
and they will be useful to interpret state-of-the art experiments on these
systems.",1910.01405v2
2020-01-19,Dephasing of Transverse Spin Current in Ferrimagnetic Alloys,"It has been predicted that transverse spin current can propagate coherently
(without dephasing) over a long distance in antiferromagnetically ordered
metals. Here, we estimate the dephasing length of transverse spin current in
ferrimagnetic CoGd alloys by spin pumping measurements across the compensation
point. A modified drift-diffusion model, which accounts for spin-current
transmission through the ferrimagnet, reveals that the dephasing length is
about 4-5 times longer in nearly compensated CoGd than in ferromagnetic metals.
This finding suggests that antiferromagnetic order can mitigate spin dephasing
-- in a manner analogous to spin echo rephasing for nuclear and qubit spin
systems -- even in structurally disordered alloys at room temperature. We also
find evidence that transverse spin current interacts more strongly with the Co
sublattice than the Gd sublattice. Our results provide fundamental insights
into the interplay between spin current and antiferromagnetic order, which are
crucial for engineering spin torque effects in ferrimagnetic and
antiferromagnetic metals.",2001.06918v5
2017-05-03,Synthetic ferrimagnet spin transfer torque oscillator: model and non-linear properties,"The non-linear parameters of spin-torque oscillators based on a synthetic
ferrimagnet free layer (two coupled layers) are computed. The analytical
expressions are compared to macrospin simulations in the case of a synthetic
ferrimagnet excited by a current spin-polarized by an external fixed layer. It
is shown that, of the two linear modes, acoustic and optical, only one is
excited at a time, and therefore the self-sustained oscillations are similar to
the dynamics of a single layer. However, the non-linear parameters values can
be controlled by the parameters of the synthetic ferrimagnet. With a strong
coupling between the two layers and asymmetric layers (different thicknesses),
it is demonstrated that the non-linear frequency shift can be reduced, which
results in the reduction of the linewidth of the power spectral density. For a
particular applied field, the non-linear parameter can even vanish; this
corresponds to a transition between a red-shift and a blue-shift frequency
dependence on the current and a linewidth reduction to the linear linewidth
value.",1705.01335v1
2017-05-13,"Partial Ferrimagnetism in S=1/2 Heisenberg Ladders with a Ferromagnetic Leg, an Antiferromagnetic Leg, and Antiferromagnetic Rungs","Ground-state and finite-temperature properties of $S=1/2$ Heisenberg ladders
with a ferromagnetic leg, an antiferromagnetic leg, and antiferromagnetic rungs
are studied. It is shown that a partial ferrimagnetic phase extends over a wide
parameter range in the ground state. The numerical results are supported by an
analytical calculation based on a mapping onto the nonlinear $\sigma$ model and
a perturbation calculation from the strong-rung limit. It is shown that the
partial ferrimagnetic state is a spontaneously magnetized Tomonaga--Luttinger
liquid with incommensurate magnetic correlation, which is confirmed by a DMRG
calculation. The finite-temperature magnetic susceptibility is calculated using
the thermal pure quantum state method. It is suggested that the susceptibility
diverges as $T^{-2}$ in the ferrimagnetic phases as in the case of
ferromagnetic Heisenberg chains.",1705.04836v2
2017-05-29,Distinct domain-wall motion between creep and flow regimes near the angular momentum compensation temperature of ferrimagnet,"We investigate a magnetic domain-wall (DW) motion in two dynamic regimes,
creep and flow regimes, near the angular momentum compensation temperature
(T_A) of ferrimagnet. In the flow regime, the DW speed shows sharp increase at
T_A due to the emergence of antiferromagnetic DW dynamics. In the creep regime,
however, the DW speed exhibits a monotonic increase with increasing the
temperature. This result suggests that, in the creep regime, the thermal
activation process governs the DW dynamics even near T_A. Our result
unambiguously shows the distinct behavior of ferrimagnetic DW motion depending
on the dynamic regime, which is important for emerging ferrimagnet-based
spintronic applications.",1705.10062v1
2018-06-04,Current-induced domain wall motion in compensated ferrimagnet,"Due to the difficulty in detecting and manipulating magnetic states of
antiferromagnetic materials, studying their switching dynamics using electrical
methods remains a challenging task. In this work, by employing heavy metal/rare
earth-transition metal alloy bilayers, we experimentally studied
current-induced domain wall dynamics in an antiferromagnetically coupled
system. We show that the current-induced domain wall mobility reaches a maximum
close to the angular momentum compensation. With experiment and modelling, we
further reveal the internal structures of domain walls and the underlying
mechanisms for their fast motion. We show that the chirality of the
ferrimagnetic domain walls remains the same across the compensation points,
suggesting that spin orientations of specific sublattices rather than net
magnetization determine Dzyaloshinskii-Moriya interaction in heavy
metal/ferrimagnet bilayers. The high current-induced domain wall mobility and
the robust domain wall chirality in compensated ferrimagnetic material opens
new opportunities for high-speed spintronic devices.",1806.01167v1
2018-07-06,Spin-torque-induced magnetization dynamics in ferrimagnets based on Landau-Lifshitz-Bloch Equation,"A theoretical model based on the Landau-Lifshitz-Bloch equation is developed
to study the spin-torque effect in ferrimagnets. Experimental findings, such as
the temperature dependence, the peak in spin torque, and the angular-momentum
compensation, can be well captured. In contrast to the ferromagnet system, the
switching trajectory in ferrimagnets is found to be precession free. The two
sublattices are not always collinear, which produces large exchange field
affecting the magnetization dynamics. The study of material composition shows
the existence of an oscillation region at intermediate current density, induced
by the nondeterministic switching. Compared to the Landau-Lifshitz-Gilbert
model, our developed model based on the Landau-Lifshitz-Bloch equation enables
the systematic study of spin-torque effect and the evaluation of
ferrimagnet-based devices.",1807.02445v1
2018-08-20,Tunable Magnonic Thermal Hall Effect in Skyrmion Crystal Phases of Ferrimagnets,"We theoretically study the thermal Hall effect by magnons in skyrmion crystal
phases of ferrimagnets in the vicinity of the angular momentum compensation
point (CP). To this end, we start by deriving the equation of motion for
magnons in the background of an arbitrary equilibrium spin texture, which gives
rise to the fictitious electromagnetic field for magnons. As the net spin
density varies, the resultant equation of motion interpolates between the
relativistic Klein-Gordon equation at CP and the nonrelativistic
Schr{\""o}dinger-like equation away from it. In skyrmion crystal phases, the
right- and the left-circularly polarized magnons with respect to the order
parameter are shown to form the Landau levels separately within the uniform
skyrmion-density approximation. For an experimental proposal, we predict that
the magnonic thermal Hall conductivity changes its sign when the ferrimagnet is
tuned across CP, providing a way to control heat flux in spin-caloritronic
devices on the one hand and a feasible way to detect CP of ferrimagnets on the
other hand.",1808.06690v1
2019-03-11,High Field Anomalies of Equilibrium and Ultrafast Magnetism in Rare-Earth-Transition Metal Ferrimagnets,"Magneto-optical spectroscopy in fields up to 30 Tesla reveals anomalies in
the equilibrium and ultrafast magnetic properties of the ferrimagnetic
rare-earth-transition metal alloy TbFeCo. In particular, in the vicinity of the
magnetization compensation temperature, each of the magnetizations of the
antiferromagnetically coupled Tb and FeCo sublattices show triple hysteresis
loops. Contrary to state-of-the-art theory, which explains such loops by sample
inhomogeneities, here we show that they are an intrinsic property of the
rare-earth ferrimagnets. Assuming that the rare-earth ions are paramagnetic and
have a non-zero orbital momentum in the ground state and, therefore, a large
magnetic anisotropy, we are able to reproduce the experimentally observed
behavior in equilibrium. The same theory is also able to describe the
experimentally observed critical slowdown of the spin dynamics in the vicinity
of the magnetization compensation temperature, emphasizing the role played by
the orbital momentum in static and ultrafast magnetism of ferrimagnets.",1903.04293v1
2019-08-18,Anomalous magnetic behavior and complex magnetic structure of proximate LaCrO3 LaFeO3 system,"We investigated complex magnetic properties of multifunctional LaCrO3-LaFeO3
system. The magnetic measurements substantiate the presence of competing
complex magnetic ordering against temperature, showing paramagnetic to
ferrimagnetic transition at 300 K, followed by antiferromagnetic (AFM)
transition near 250 K superimposed on ferrimagnetic phase. The onset of weak
ferrimagnetic ordering is attributed to the competing complex interaction
between two AFM LaCrO3-LaFeO3 sublattices. The low-temperature AFM ordering is
also substantiated by temperature-dependent Raman measurements, where the
intensity ratio of 700 cm-1 Raman active mode showed the clear enhancement with
lowering the temperature. The non-saturating nature of magnetic moments in
LaCrO3-LaFeO6 suggests the predominating AFM ordering in conjunction with
ferrimagnetic ordering between 250 K to 300 K up to 5 T magnetic field. A
complex magnetic structure of LaCrO3-LaFeO3 is constructed, emphasizing the
metastable magnetic phase near room temperature and low temperature
antiferromagnetic state.",1908.06450v1
2019-11-25,Identification of ferrimagnetic orbitals preventing spinel degradation by charge ordering in Li$_x$Mn$_2$O$_4$,"Spinel Li$_x$Mn$_2$O$_4$ is a key cathode material that is used extensively
in commercial Li-ion batteries. A challenge with this material has been that
the capacity of the battery fades with cycling, an effect that can be traced to
the presence of an anti-ferromagnetic insulator phase in the fully lithiated
LiMn$_2$O$_4$ (LMO) and the associated charge disproportionation that drives
distortions of the MnO$_6$ octahedra. Here, by combining x-ray magnetic Compton
scattering experiments with parallel first-principles computations, we show
that the anti-ferromagnetic phase of LMO is surrounded by a robust
ferrimagnetic metallic phase, which becomes stable when even a small amount of
Li is removed from or added to the charge-ordered LMO. In this surprising
ferrimagnetic state, charge-ordering and octahedral distortions are found to be
strongly suppressed. We identify the nature of the ferrimagnetic orbitals
involved through theoretical and experimental analyses of the magnetic Compton
scattering spectra.",1911.11183v1
2020-05-02,Optically driven ultrafast magnetic order transitions in two-dimensional ferrimagnets,"Laser-induced switching and manipulation of the spins in magnetic materials
are of great interest to revolutionize future magnetic storage technology and
spintronics with fastest speed and least power dissipative. Inspired by the
recent discovery of intrinsic two-dimensional (2D) magnets, which provide
unique platform to explore the new phenomenon for light-control magnetism in
the 2D limit, we propose to realize light can efficiently tune magnetic
properties of 2D ferrimagnets in early time. Here, using the 2D ferrimagnetic
MXenes as prototype systems, our real-time density functional theory (TDDFT)
simulation show that laser pulses can directly induce ultrafast spin-selective
charge transfer between two magnetic sublattices on a few femtoseconds, and
further generate dramatic changes in the magnetic structure of these MXenes,
including a magnetic order transition from ferrimagnetic (FiM) to transient
ferromagnetic (FM). The microscopic mechanism underpinning this ultrafast
switching of magnetic order in MXenes is governed by optically induced
inter-site spin transfer (OISTR) effect, which theoretically enables the
ultrafast direct optical manipulation of the magnetic state in MXenes-based
materials. Our results open new opportunities to optically manipulate the spin
in 2D magnets.",2005.00871v1
2020-05-18,Noncollinear Magnetic Modulation of Weyl Nodes in Ferrimagnetic Mn$_3$Ga,"The tetragonal ferrimagnetic Mn$_3$Ga exhibits a wide range of intriguing
magnetic properties. Here, we report the emergence of topologically nontrivial
nodal lines in the absence of spin orbit coupling (SOC) which are protected by
both mirror and $C_{4z}$ rotational symmetries. In the presence of SOC we
demonstrate that the doubly degenerate nontrivial crossing points evolve into
$C_{4z}$-protected Weyl nodes with chiral charge of $\pm$2. Furthermore, we
have considered the experimentally reported noncollinear ferrimagnetic
structure, where the magnetic moment of the Mn$_I$ atom (on the Mn-Ga plane) is
tilted by an angle $\theta$ with respect to the crystallographic $c$ axis. The
evolution of the Weyl nodes with $\theta$ reveals that the double Weyl nodes
split into a pair of charge-1 Weyl nodes whose separation can be tuned by the
magnetic orientation in the noncollinear ferrimagnetic structure.",2005.08914v3
2021-03-06,Anomalies in the dynamics of ferrimagnets near the angular momentum compensation point,"In this paper, we elaborate analytical theory of domain wall dynamics close
to the angular momentum compensation point based on non-linear dynamic
equations derived from the effective Lagrangian of a ferrimagnet. Analysis of
the precession angle and domain wall velocity oscillations in post Walker
regime in a ferrimagnet is performed. In the framework of the proposed model,
we explore dynamic processes in the Walker and post Walker regimes. We show
that although spin oscillations quench the dynamics of domain walls near the
Walker breakdown field, a further increase of the driving magnetic field
increases domain wall speed and mobility. An anomalous behavior of domain wall
dynamic properties near the angular momentum compensation point in ferrimagnets
is discussed.",2103.04105v1
2021-04-06,Landau-Lifshitz-Bloch equation for ferrimagnets with higher-order interaction,"We present a micromagnetic formulation for modeling the magnetization
dynamics and thermal equilibrium in ferrimagnetic materials at low and elevated
temperatures. The formulation is based on a mean field approximation (MFA). In
this formulation, the ferrimagnet is described micromagnetically by two coupled
sublattices with corresponding interactions, including inter- and
intra-sublattice micromagnetic exchange as well as four-spin interactions
described as an inter-sublattice molecular field with a cubic dependence of the
magnetization. The MFA is used to derive a Landau Lifshitz Bloch type equation
for ferrimagnetic material, including cases with a ferromagnetic -
antiferromagnetic phase transitions. For validation, the results obtained via
the presented model are compared with recent experimental data for phase
transitions in FeRh.",2104.02198v3
2021-09-25,Phase transitions in rare-earth ferrimagnets with surface anisotropy near the magnetization compensation point,"We report of a theoretical model for calculating the H-T phase diagrams of a
rare-earth ferrimagnet, taking into account anisotropies originated by both
magnetization sublattices' and by the surface. The possibility of an exchange
spring formation due to surface anisotropy is considered. This situation is
realized in heterostructures containing a ferrimagnet and a heavy metal. We
derive the stability lose lines of the collinear phase from the free energy of
the two sublattice ferrimagnet. We numerical calculate the magnetic phase
diagrams for the cases when the magnetic field applied along and perpendecular
to the easy axis. We demonstrate that tricritical point down at the low field
range due to surface anisotropy effect. Moreover, the line of the first order
phase transition between angular and collinear phases reduces due to surface
anisotropy. In the case when magnetic field is applied perpendicular to the
easy axis we show the possibility of the first order phase transition between
two collinear phases in contrast to the phase diagram without surface
anisotropy.",2109.12377v2
2021-11-11,Kondo effect in Lieb's ferrimagnetic system on the T-shaped bipartite lattice,"The minimal ferrimagnetism by Lieb's theorem emerges on the T-shaped
bipartite lattice composed of four sites, which can be realized experimentally,
just as Nagaoka ferromagnetism has been demonstrated experimentally using a
quartet quantum-dot(J.P.Dehollain et al., Nature 579, 528 (2020).). In this
paper, the Kondo effect on this ferrimagnetism is theoretically studied. The
magnetic moment $S=1$ is screened in two steps by the Kondo effect and the
series conductance $g_{s}$ is strongly suppressed to $g_{s}\simeq 0$, while the
parallel conductance $g_{p}$ has the maximum value $g_{p}\simeq 4e^{2}/h$. The
robustness of these properties against a parameter change toward reducing the
Lieb's ferrimagnetism is also discussed, showing the scenarios for entanglement
of the degrees of freedom toward the ground state.",2111.06045v3
2021-12-14,"Ground State, Magnetization Process and Bipartite Quantum Entanglement of a Spin-1/2 Ising-Heisenberg Model on Planar Lattices of Interconnected Trigonal Bipyramids","The ground state, magnetization scenario and the local bipartite quantum
entanglement of a mixed spin-$1/2$ Ising--Heisenberg model in a magnetic field
on planar lattices formed by identical corner-sharing bipyramidal plaquettes is
examined by combining the exact analytical concept of generalized
decoration-iteration mapping transformations with Monte Carlo simulations
utilizing the Metropolis algorithm. The ground-state phase diagram of the model
involves six different phases, namely, the standard ferrimagnetic phase, fully
saturated phase, two unique quantum ferrimagnetic phases, and two
macroscopically degenerate quantum ferrimagnetic phases with two chiral degrees
of freedom of the Heisenberg triangular clusters. The diversity of ground-state
spin arrangement is manifested themselves in seven different magnetization
scenarios with one, two or three fractional plateaus whose values are
determined by the number of corner-sharing plaquettes. The low-temperature
values of the concurrence demonstrate that the bipartite quantum entanglement
of the Heisenberg spins in quantum ferrimagnetic phases is field independent,
but twice as strong if the Heisenberg spin arrangement is unique as it is
two-fold degenerate.",2112.07233v1
2022-01-22,Universal criteria for single femtosecond pulse ultrafast magnetization switching in ferrimagnets,"Single-pulse switching has been experimentally demonstrated in ferrimagnetic
GdFeCo and Mn$_2$Ru$_x$Ga alloys. Complete understanding of single-pulse
switching is missing due to the lack of an established theory accurately
describing the transition to the non-equilibrium reversal path induced by
femtosecond laser photo-excitation. In this work we present general macroscopic
theory for the magnetization dynamics of ferrimagnetic materials upon
femtosecond laser excitation. Our theory reproduces quantitatively all stages
of the switching process observed in experiments. We directly compare our
theory to computer simulations using atomistic spin dynamics methods for both
GdFeCo and Mn$_2$Ru$_x$Ga alloys. We provide explicit expressions for the
magnetization relaxation rates in terms of microscopic parameters which allows
us to propose universal criteria for switching in ferrimagnets.",2201.09067v1
2022-04-25,Ultrafast racetrack based on compensated Co/Gd-based synthetic ferrimagnet with all-optical switching,"Spin-orbitronics and single pulse all-optical switching (AOS) of
magnetization are two major successes of the rapidly advancing field of
nanomagnetism in recent years, with high potential for enabling novel, fast and
energy-efficient memory and logic platforms. Fast current-induced domain wall
motion (CIDWM) and single shot AOS have been individually demonstrated in
different ferrimagnetic alloys. However, the stringent requirement for their
composition control makes these alloys challenging materials for wafer-scale
production. Here, we simultaneously demonstrate fast CIDWM and energy efficient
AOS in a synthetic ferrimagnetic system based on multilayered [Co/Gd/Co/Gd]. We
firstly show that AOS is present in its full composition range. We find that
current-driven domain wall velocities over 2000 m/s at room temperature,
achieved by compensating the total angular momentum through layer thickness
tuning. Furthermore, analytical modeling of the CIDWM reveals that Joule
heating needs to be treated transiently to properly describe the CIDWM for our
sub-ns current pulses. Our studies establish [Co/Gd]-based synthetic
ferrimagnets to be a unique materials platform for domain wall devices with
access to ultrafast single pulse AOS.",2204.11595v1
2022-10-25,Ultrafast Switching in Synthetic Antiferromagnet with Bilayer Rare-Earth Transition-Metal Ferrimagnets,"In spintronics, it is important to be able to manipulate magnetization
rapidly and reliably. Several methods can control magnetization, such as by
applying current pulses or magnetic fields. An applied current can reverse
magnetization with nanosecond speed through the spin torque effect. For faster
switching, subpicosecond switching with femtoseconds laser pulse has been
achieved in amorphous rare-earth transition-metal ferrimagnets. In this study,
we employed atomistic simulations to investigate ultrafast switching in a
synthetic antiferromagnet with bilayer amorphous FeGd ferrimagnets. Using a
two-temperature model, we demonstrated ultrafast switching in this synthetic
antiferromagnet without external magnetic fields. Furthermore, we showed that
if we initially stabilize a skyrmion in this heterostructure, the ultrafast
laser can switch the skyrmion state using the same mechanism. Furthermore, this
bilayer design allows the control of each ferrimagnetic layer individually and
opens the possibility for a magnetic tunnel junction.",2210.14119v1
2022-11-28,Anomalous Nernst effect in compensated ferrimagnetic CoxGd1-x films,"The anomalous Nernst effect (ANE) is one of the most intriguing
thermoelectric phenomena which has attracted growing interest both for its
underlying physics and potential applications. Typically, a large ANE response
is observed in magnets with pronounced magnetizations or nontrivial Berry
curvature. Here, we report a significant ANE signal in compensated
ferrimagnetic CoxGd1-x alloy films, which exhibit vanishingly small
magnetization. In particular, we found that the polarity of ANE signal is
dominated by the magnetization orientation of the transition metal Co
sublattices, rather than the net magnetization of CoxGd1-x films. This
observation is not expected from the conventional understanding of ANE but is
analogous to the anomalous Hall effect in compensated ferrimagnets. We
attribute the origin of ANE and its Co-dominant property to the Co-dominant
Berry curvature. Our work could trigger a more comprehensive understanding of
ANE and may be useful for building energy-harvesting devices by employing ANE
in compensated ferrimagnets.",2211.15074v1
2023-03-28,Analysis of ultrafast magnetization switching dynamics in exchange-coupled ferromagnet-ferrimagnet heterostructures,"Magnetization switching in ferromagnets has so far been limited to the
current-induced spin-orbit-torque effects. Recent observation of
helicity-independent all-optical magnetization switching in exchange-coupled
ferromagnet ferrimagnet heterostructures expanded the range and applicability
of such ultrafast heat-driven magnetization switching. Here we report the
element-resolved switching dynamics of such an exchange-coupled system, using a
modified microscopic three-temperature model. We have studied the effect of i)
the Curie temperature of the ferromagnet, ii) ferrimagnet composition, iii) the
long-range RKKY exchange-coupling strength, and iv) the absorbed optical energy
on the element-specific time-resolved magnetization dynamics. The phase-space
of magnetization illustrates how the RKKY coupling strength and the absorbed
optical energy influence the switching time. Our analysis demonstrates that the
threshold switching energy depends on the composition of the ferrimagnet and
the switching time depends on the Curie temperature of the ferromagnet as well
as RKKY coupling strength. This simulation anticipates new insights into
developing faster and more energy-efficient spintronics devices.",2303.16294v1
2023-04-27,"Room Temperature Ferrimagnetism, Magnetodielectric and Exchange Bias Effect in CoFeRhO$_4$","Geometrically frustrated structures combined with competing exchange
interactions that have different magnitudes are known ingredients for achieving
exotic properties. Herein, we studied detailed structural, magnetic, thermal
(specific heat), magneto-dielectric, and magnetic exchange bias properties of a
mixed 3d - 4d spinel oxide with composition CoFeRhO$_4$. Detailed
magnetization, heat capacity, and neutron powder diffraction studies (NPD)
highlight long-range ferrimagnetic ordering with an onset at 355 K. The
magnetic structure is established using a ferrimagnetic model (collinear-type)
that has a propagation vector k = 0, 0, 0. The magneto-dielectric effect
appears below the magnetic ordering temperature, and the exchange bias (EB)
effect is observed in field cooled (FC) conditions below 355 K. The
magneto-dielectric coupling in CoFeRhO$_4$ originates due to the frustration in
the structure, collinear ferrimagnetic ordering, and uncompensated magnetic
moments. The unidirectional anisotropy resulting from the uncompensated
magnetic moments causes the room-temperature exchange bias effect. Remarkably,
the appearance of technologically important properties (ferromagnetism,
magnetodielectric effect, and EB) at room temperature in CoFeRhO$_4$ indicates
its potential use in sensors or spintronics.",2304.13983v1
2023-07-25,Lattice structure dependence of laser-induced ultrafast magnetization switching in ferrimagnets,"The experimental discovery of single-pulse ultrafast magnetization switching
in ferrimagnetic alloys, such as GdFeCo and MnRuGa, opened the door to a
promising route toward faster and more energy efficient data storage. A recent
semi-phenomenological theory has proposed that a fast, laser-induced
demagnetization below a threshold value puts the system into a dynamical regime
where angular momentum transfer between sublattices dominates. Notably, this
threshold scales inversely proportional to the number of exchange-coupled
nearest neighbours considered in the model, which in the simplest case is
directly linked to the underlying lattice structure. In this work, we study the
role of the lattice structure on the laser-induced ultrafast magnetization
switching in ferrimagnets by complementing the phenomenological theory with
atomistic spin dynamics computer simulations. We consider a spin model of the
ferrimagnetic GdFeCo alloy with increasing number of exchange-coupled
neighbours. Within this model, we demonstrate that the laser-induced
magnetization dynamics and switching depends on the lattice structure. Further,
we determine that the critical laser energy for switching reduces for
decreasing number of exchange-coupled neighbours.",2307.13522v1
2023-09-16,Antiferromagnetic to Ferrimagnetic Phase Transition and Possible Phase Coexistence in Polar Magnets (Fe$_{1-x}$Mn$_x$)$_2$Mo$_3$O$_8$,"In the present work, magnetic properties of single crystal
(Fe$_{1-x}$Mn$_x$)$_2$Mo$_3$O$_8$ ($0<x<1$) have been studied by performing
extensive measurements. A detailed magnetic phase diagram is built up, in which
antiferromagnetic state dominates for $x<0.25$ and ferrimagnetic phase arises
for $x>0.3$. Meanwhile, sizeable electric polarization of spin origin is
commonly observed in all samples, no matter what the magnetic state is. For the
samples hosting a ferrimagnetic state, square-like magnetic hysteresis loops
are revealed, while the remnant magnetization and coercive field can be tuned
drastically by simply varying the Mn-content or temperature. Possible
coexistence of the antiferromagnetic and ferrimagnetic phases is proposed to be
responsible for the remarkable modulation of magnetic properties in the
samples.",2309.08990v1
2024-03-12,Ferrimagnetic Heusler tunnel junctions with fast spin-transfer torque switching enabled by low magnetization,"Magnetic random access memory that uses magnetic tunnel junction memory cells
is a high performance, non-volatile memory technology that goes beyond
traditional charge-based memories. Today its speed is limited by the high
magnetization of the memory storage layer. Here we show that fast and highly
reliable switching is possible using a very low magnetization ferrimagnetic
Heusler alloy, Mn3Ge. Moreover, the tunneling magnetoresistance is the highest
yet achieved for a ferrimagnetic material at ambient temperature. Furthermore,
the devices were prepared on technologically relevant amorphous substrates
using a novel combination of a nitride seed layer and a chemical templating
layer. These results show a clear path to the lowering of switching currents
using ferrimagnetic Heusler materials and, therefore, to the scaling of high
performance magnetic random access memories beyond those nodes possible with
ferromagnetic devices.",2403.08112v1
2017-07-16,Competing magnetic and spin gap-less semiconducting behaviour in fully compensated ferrimagnet CrVTiAl: Theory and Experiment,"We report the structural, magnetic and transport properties of
polycrystalline CrVTiAl alloy along with first principles calculations. It
crystallizes in the LiMgPdSn type structure with lattice parameter 6.14 \AA\ at
room temperature. Absence of (111) peak along with the presence of a weak (200)
peak indicates the antisite disorder of Al with Cr and V atoms. The
magnetization measurements reveal a ferrimagnetic transition near 710 K and a
coercive field of 100 Oe at 3 K. Very low moment and coercive field indicate
fully compensated ferrimagnetism in the alloy. Temperature coefficient of
resistivity is found to be negative, indicating a characteristic of
semiconducting nature. Absence of exponential dependence of resistivity on
temperature indicates a gapless/spin-gapless semiconducting behaviour.
Electronic and magnetic properties of CrVTiAl for three possible
crystallograpic configurations are studied theoretically. All the three
configurations are found to be different forms of semiconductors. Ground state
configuration is a fully compensated ferrimagnet with band gaps 0.58 eV and
0.30 eV for up and down spin bands respectively. The next higher energy
configuration is also ferrimagnetic, but has spin-gapless semiconducting
nature. The highest energy configuration corresponds to a non-magnetic gapless
semiconductor. The energy differences among these configurations are quite
small ($<$ 1 $\mathrm{mRy/atom}$) which hints that at finite temperatures, the
alloy exists in a disordered phase, which is a mixture of the three
configurations. By taking into account the theoretical and the experimental
findings, we conclude that CrVTiAl is a fully compensated ferrimagnet with
predominantly spin gap-less semiconductor nature.",1707.04854v1
2016-07-29,"A rock-salt type Li-based oxide, Li3Ni2RuO6, exhibiting a chaotic ferrimagnetism with cluster spin-glass dynamics and thermally frozen charge carriers","The area of research to discover new Li containing materials and to
understand their physical properties has been of constant interest due to
applications potential for rechargeable batteries. Here, we present the results
of magnetic investigations on a Li compound, Li3Ni2RuO6, which was believed to
be a ferrimagnet below 80K. While our neutron diffraction (ND) and isothermal
magnetization (M) data support ferrimagnetism, more detailed magnetic studies
establish that this ferrimagnetic phase exhibits some features similar to
spin-glasses. In addition, we find another broad magnetic anomaly around 40-55
K in magnetic susceptibility, attributable to cluster spin-glass phenomenon.
Gradual dominance of cluster spin-glass dynamics with a decrease of temperature
(T) and the apparent spread in freezing temperature suggest that the
ferrimagnetism of this compound is a chaotic one. The absence of a unique
freezing temperature for a crystalline material is interesting. In addition,
pyroelectric current data reveals a feature in the range 40-50 K, attributable
to thermally stimulated depolarization current. We hope this finding motivates
future work to explore whether there is any intriguing correlation of such a
feature with spin-glass dynamics. We attribute these magnetic and electric
dipole anomalies to the crystallographic disorder intrinsic to this compound.",1607.08689v1
2019-09-30,Disorder-induced ferrimagnetism in sputtered Mn$_{x}$CoGe thin films,"Investigations into the magnetic properties of sputtered Mn$_{x}$CoGe films
in the range $0.8 \leq x \leq 2.5$ uncovered ferrimagnetic order, unlike the
ferromagnetic order reported in bulk samples. These films formed hexagonal
Ni$_{2}$In-type structures when annealed at temperatures below 600$^{\circ}$C.
While the Curie temperatures of the films are comparable to those of hexagonal
bulk MnCoGe, there is a reduction in the magnetization of the Mn$_{x}$CoGe
films relative to bulk MnCoGe, and a magnetization compensation point is
observed in the $x<1$ samples. To understand the behavior, we calculated the
magnetic moments of Mn-antisite defects in MnCoGe with density-function theory
(DFT) calculations. Models constructed from the calculation suggest that films
become ferrimagnetic due to the presence of Mn on the Co and Ge sites. In the
$x<1$ samples, these defects arose from the disorder in the films, whereas for
$x>1$, the excess Mn was driven onto the antisites. Mean field modeling of the
temperature dependence of the magnetization provides additional evidence for
ferrimagnetism. Our mean field and DFT models provide a description of how the
variation in film defects with composition will transition the magnetic
behavior from a compensated (V-type) to an uncompensated (Q-type) ferrimagnet.",1910.00124v3
2020-12-18,Rare-earth-free ferrimagnetic Mn4N sub-20 nm thin films as high-temperature spintronic material,"Ferrimagnetic alloy thin films that exhibit perpendicular (out-of-plane)
magnetic anisotropy (PMA) with low saturation magnetization, such as GdCo and
Mn4N, were predicted to be favorable for hosting small Neel skyrmions for room
temperature applications. Due to the exponential decay of interfacial
Dzyaloshinskii-Moriya interaction (DMI) and the limited range of
spin-orbit-torques, which can be used to drive skyrmion motion, the thickness
of the ferrimagnetic layer has to be small, preferably under 20 nm. While there
are examples of sub-20 nm, rare earth-transition metal (RE-TM), ferrimagnetic
thin films fabricated by sputter deposition, to date rare-earth-free sub-20 nm
Mn4N films with PMA have only been reported to be achieved by molecular beam
epitaxy, which is not suitable for massive production. Here we report the
successful thermal growth of sub-20 nm Mn4N films with PMA at 400-450 {\deg}C
substrate temperatures on MgO substrates by reactive sputtering. The Mn4N films
were achieved by reducing the surface roughness of MgO substrate through a
high-temperature vacuum annealing process. The optimal films showed low
saturation magnetization (Ms = 43 emu/cc), low magnetic anisotropy energy (0.7
Merg/cc), and a remanent magnetization to saturation magnetization ratio
(Mr/Ms) near 1 at room temperature. Preliminary ab-initio density functional
theory (DFT) calculations have confirmed the ferrimagnetic ground state of Mn4N
grown on MgO. The magnetic properties, along with the high thermal stability of
Mn4N thin films in comparison with RE-TM thin films, provide the platform for
future studies of practical skyrmion-based spintronic materials.",2012.10493v1
2017-05-25,Fast Vortex Oscillations in a Ferrimagnetic Disk near the Angular Momentum Compensation Point,"We theoretically study the oscillatory dynamics of a vortex core in a
ferrimagnetic disk near its angular momentum compensation point, where the spin
density vanishes but the magnetization is finite. Due to the finite
magnetostatic energy, a ferrimagnetic disk of suitable geometry can support a
vortex as a ground state similar to a ferromagnetic disk. In the vicinity of
the angular momentum compensation point, the dynamics of the vortex resemble
those of an antiferromagnetic vortex, which is described by equations of motion
analogous to Newton's second law for the motion of particles. Owing to the
antiferromagnetic nature of the dynamics, the vortex oscillation frequency can
be an order of magnitude larger than the frequency of a ferromagnetic vortex,
amounting to tens of GHz in common transition-metal based alloys. We show that
the frequency can be controlled either by applying an external field or by
changing the temperature. In particular, the latter property allows us to
detect the angular momentum compensation temperature, at which the lowest
eigenfrequency attains its maximum, by performing FMR measurements on the
vortex disk. Our work proposes a ferrimagnetic vortex disk as a tunable source
of fast magnetic oscillations and a useful platform to study the properties of
ferrimagnets.",1705.09049v2
2020-09-25,Temperature dependence of the damping parameter in the ferrimagnet Gd$_3$Fe$_5$O$_{12}$,"The damping parameter ${\alpha}_{\text{FM}}$ in ferrimagnets defined
according to the conventional practice for ferromagnets is known to be strongly
temperature dependent and diverge at the angular momentum compensation
temperature, where the net angular momentum vanishes. However, recent
theoretical and experimental developments on ferrimagnetic metals suggest that
the damping parameter can be defined in such a way, which we denote by
${\alpha}_{\text{FiM}}$, that it is free of the diverging anomaly at the
angular momentum compensation point and is little dependent on temperature. To
further understand the temperature dependence of the damping parameter in
ferrimagnets, we analyze several data sets from literature for a ferrimagnetic
insulator, gadolinium iron garnet, by using the two different definitions of
the damping parameter. Using two methods to estimate the individual sublattice
magnetizations, which yield results consistent with each other, we found that
in all the used data sets, the damping parameter ${\alpha}_{\text{FiM}}$ does
not increase at the angular compensation temperature and shows no anomaly
whereas the conventionally defined ${\alpha}_{\text{FM}}$ is strongly dependent
on the temperature.",2009.12073v2
2022-01-11,Effect of a Gaussian random external magnetic field with spatio temporal variation on compensation in Ising spin-1/2 trilayered square ferrimagnets,"In this work, an extensive Metropolis Monte Carlo simulation is performed to
investigate the steady-state magnetic and thermodynamic behaviour of a
trilayered spin-1/2 Ising ferrimagnet with square monolayers, driven by
external Gaussian random magnetic field with certain spatio-temporal
variations. Such thin ferrimagnetic systems exhibit compensation phenomenon and
thus are potentially interesting candidates for several technological
applications. Here, two distinct theoretical atoms, A and B, make up the ABA
and AAB types of configurations in which the like atoms (A-A and B-B)
ferromagnetically interact and the unlike atoms (A-B) interact
antiferromagnetically. Depending upon the strength of the spatio-temporally
varying Gaussian random field, the compensation and critical points shift and
steady-state magnetic behaviours change between the different distinct types of
ferrimagnetic behaviours. The compensation phenomenon even vanishes after
crossing a finite threshold of the standard deviation of the magnetic field for
particular choices of the other controlling parameters. Consequently, in the
Hamiltonian parameter space of both configurations, islands of ferrimagnetic
phase without compensation appear within the phase area with compensation of
field-free case. The areas of such islands grow with an increasing standard
deviation of the external field, $\sigma$, obeying the scaling relation:
$f(\sigma, A(\sigma))=\sigma^{-b}A(\sigma)$ with $b_{ABA}=1.913\pm 0.137$ and
$b_{AAB}=1.625\pm 0.066$ . These values of exponents match within the
statistical interval with those obtained with the uniform random magnetic
field.",2201.03883v4
2022-03-29,Realistic micromagnetic description of all-optical ultrafast switching processes in ferrimagnetic alloys,"Both helicity-independent and helicity-dependent all-optical switching
processes driven by single ultrashort laser pulse have been experimentally
demonstrated in ferrimagnetic alloys as GdFeCo. Although the switching has been
previously reproduced by atomistic simulations, the lack of a robust
micromagnetic framework for ferrimagnets limits the predictions to small
nano-systems, whereas the experiments are usually performed with lasers and
samples of tens of micrometers. Here we develop a micromagnetic model based on
the extended Landau-Lifshitz-Bloch equation, which is firstly validated by
directly reproducing atomistic results for small samples and uniform laser
heating. After that, the model is used to study ultrafast single shot
all-optical switching in ferrimagnetic alloys under realistic conditions. We
find that the helicity-independent switching under a linearly polarized laser
pulse is a pure thermal phenomenon, in which the size of inverted area directly
correlates with the maximum electron temperature in the sample. On the other
hand, the analysis of the helicity-dependent processes under circular polarized
pulses in ferrimagnetic alloys with different composition indicates qualitative
differences between the results predicted by the magnetic circular dichroism
and the ones from inverse Faraday effect. Based on these predictions, we
propose experiments that would allow to resolve the controversy over the
physical phenomenon that underlies these helicity-dependent all optical
processes.",2203.15460v1
2022-05-28,Helicity-independent all-optical switching of magnetization in ferrimagnetic alloys,"We review and discuss the process of single-shot helicity-independent
all-optical switching of magnetization by which a single suitably-ultrafast
excitation, under the right conditions, toggles magnetization from one stable
state to another. For almost a decade, this phenomenon was only consistently
observed in specific rare-earth-transition-metal ferrimagnetic alloys of
GdFeCo, but breakthrough experiments in recent years have revealed that the
same behavior can be achieved in a wide range of multi-sublattice magnets
including TbCo alloys doped with minute amounts of Gd, Gd/Co and Tb/Co
synthetic ferrimagnets, and the rare-earth-free Heusler alloy Mn$_2$Ru$_x$Ga.
Aiming to resolve the conditions that allow switching, a series of experiments
have shown that the process in the ferrimagnetic alloys GdFeCo and
Mn$_2$Ru$_x$Ga is highly sensitive to the pulse duration, starting temperature
and the alloy composition. We argue here that the switching displayed by these
two very different ferrimagnetic alloys can be generally understood within a
single phenomenological framework describing the flow of angular momentum
between the constituent sublattices and from the sublattices to the
environment. The conditions that facilitate switching stem from the properties
of these channels of angular momentum flow in combination with the size of the
angular momentum reservoirs. We conclude with providing an outlook in this
vibrant research field, with emphasis on the outstanding open questions
pertaining to the underlying physics along with noting the advances in
exploiting this switching process in technological applications.",2205.14342v1
2022-11-22,Spatially Nonuniform Oscillations in Ferrimagnets Based on an Atomistic Model,"The ferrimagnets, such as GdxFeCo(1-x), can produce ultrafast magnetic
switching and oscillation due to the strong exchange field. The two-sublattices
macrospin model has been widely used to explain the experimental results.
However, it fails in describing the spatial nonuniform magnetic dynamics which
gives rises to many important phenomenons such as the domain walls and
skyrmions. Here we develop the two-dimensional atomistic model and provide a
torque analysis method to study the ferrimagnetic oscillation. Under the
spin-transfer torque, the magnetization oscillates in the exchange mode or the
flipped exchange mode. When the Gd composition is increased, the exchange mode
firstly disappears, and then appears again as the magnetization compensation
point is reached. We show that these results can only be explained by analyzing
the spatial distribution of magnetization and effective fields. In particular,
when the sample is small, a spatial nonuniform oscillation is also observed in
the square film. Our work reveals the importance of spatial magnetic
distributions in understanding the ferrimagnetic dynamics. The method developed
in this paper provides an important tool to gain a deeper understanding of
ferrimagnets and antiferromagnets. The observed ultrafast dynamics can also
stimulate the development of THz oscillators.",2211.12247v1
2022-11-30,Unconventional spin dynamics in the non-collinear phase of a ferrimagnet,"Ferrimagnets containing several partially compensated magnetic sublattices
are considered the most promising materials for all-optical data storage and
for ultrafast communications based on spin waves. There are two magnetic phases
of the ferrimagnets: collinear and non-collinear ones. Up to now spin dynamics
in ferrimagnets has been studied mostly in the collinear state without paying
much attention to the kind of the magnetic phase. Here we investigate laser
induced ultrafast spin dynamics in a rare-earth iron garnet film in the
noncollinear phase as well. We identify a crucial influence of the magnetic
phase on the excited spin modes which allowed us to discover several prominent
effects previously overlooked. In particular, the non-collinearity makes the
quasi-antiferromagnetic mode sensitive to the external magnetic field and
brings its frequency close to the frequency of the quasiferromagnetic mode. The
latter maximizes near the magnetization compensation point and vanishes towards
the collinear phase. Spectacularly, at the phase transition the
quasiferromagnetic mode becomes soft and its amplitude significantly increases
reaching 7{\deg}. This opens new opportunities for the ultrafast control of
spins in ferrimagnets for nonthermal data storage and data processing.",2212.00085v2
2023-03-27,Strain effects on magnetic compensation and spin reorientation transition of Co/Gd synthetic ferrimagnets,"Synthetic ferrimagnets are an attractive materials class for spintronics as
they provide access to all-optical switching of magnetization and, at the same
time, allow for ultrafast domain wall motion at angular momentum compensation.
In this work, we systematically study the effects of strain on the
perpendicular magnetic anisotropy and magnetization compensation of Co/Gd and
Co/Gd/Co/Gd synthetic ferrimagnets. Firstly, the spin reorientation transition
of a bilayer system is investigated in wedge type samples, where we report an
increase in the perpendicular magnetic anisotropy in the presence of in-plane
strain. Using a model for magnetostatics and spin reorientation transition in
this type of system, we confirm that the observed changes in anisotropy field
are mainly due to the Co magnetoelastic anisotropy. Secondly, the magnetization
compensation of a quadlayer is studied. We find that magnetization compensation
of this synthetic ferrimagnetic system is not altered by external strain. This
confirms the resilience of this material system against strain that may be
induced during the integration process, making Co/Gd ferrimagnets suitable
candidates for spintronics applications.",2303.15191v4
2023-12-12,Dzyaloshinskii-Moriya interaction inducing weak ferromagnetism in centrosymmetric altermagnets and weak ferrimagnetism in noncentrosymmetric altermagnets,"The Dzyaloshinskii-Moriya interaction (DMI) has explained successfully the
weak ferromagnetism in some centrosymmetric antiferromagnets. However, in the
last years, it was generally claimed that the DMI is not effective in
centrosymmetric systems. We reconciled these views by separating the
conventional antiferromagnets and altermagnets. Altermagnets represent
collinear antiferromagnetic compounds with spin-up and spin-down sublattices
connected only by mirror and roto-translational symmetries. Consequently, the
system shows even-parity wave spin order in the k-space lifting the Kramer's
degeneracy in the non-relativistic band structure. We emphasize that the DMI
can create weak ferromagnetism in centrosymmetric altermagnets while it is not
effective in centrosymmetric conventional antiferromagnets. Additionally, DMI
can create weak ferromagnetism or weak ferrimagnetism in noncentrosymmetric
altermagnets. Once the spin-orbit coupling is included in an altermagnetic
system without time-reversal symmetry, the components of spin moments of the
two sublattices along the Neel vector are antiparallel but the other two spin
components orthogonal to the N\'eel vector can be either parallel or
antiparallel for centrosymetric systems. For noncentrosymmetric systems, we can
have different bands showing parallel or antiparallel spin components resulting
in weak ferrimagnetism. We can divide the altermagnetic compounds into classes
based on the weak ferromagnetism or weak ferrimagnetism properties. The weak
ferromagnetism and weak ferrimagnetism induced by DMI is a property exclusively
of the altermagnets, not present in either ferromagnets or conventional
antiferromagnets so we propose that altermagnets should be classified based on
this property.",2312.07678v2
2006-07-26,59Co-NMR Probe for Stepwise Magnetization and Magnetotransport in SrCo6O11 with Metallic Kagome Layer and Triangular Lattice with Local Moments,"We report on novel magnetic and electronic properties of SrCo6O11 that
exhibits a unique stepwise magnetization and its relevant magnetotransport
phenomena investigated by the site-selective 59Co nuclear magnetic resonance
(NMR) at zero and applied magnetic fields. This compound is composed of three
Co sites in the unit cell, i.e., Co(1) in the metallic Kagome layer, a Co(2)
dimerized pillar between the layers and Co(3) in the triangular lattice.
Zero-field NMR spectra have revealed that large local moments at the Co(3)
sites are magnetically ordered without any trace of bulk magnetization M at
zero field. The field-swept NMR spectra show that the internal hyperfine field
at the Co(1) site is derived from fully polarized moments Ms at the Co(3) sites
in the ""1""-plateau state at fields higher than 2.5 T, whereas it is partially
cancelled out in the ""1/3""-plateau state in which one-third of Ms is induced at
intermediate fields once a small field is applied. It has been clarified from a
microscopic point of view that the local moments at Co(3) site undergo a
field-induced ferrimagnetic (up-up-down)-to-ferromagnetic (up-up-up)
transition, which is consistent with the evidence obtained from the recent
neutron diffraction experiment. The Co(1) Kagome layer and the dimerized pillar
Co(2) site between the layers are of nonmagnetic origin, suggesting that the
nearly quasi-2D metallic conductivity is dominated by nonmagnetic Co(1) and
Co(2) sites. Consequently, unique magneto-transport phenomena observed in
SrCo6O11 are demonstrated owing to the interaction between the conduction
electrons at the Co(1) and Co(2) sites and the local moments at Co(3) sites.",0607677v1
2019-10-11,"Low-Damping Ferromagnetic Resonance in Electron-Beam Patterned, High-$Q$ Vanadium Tetracyanoethylene Magnon Cavities","Integrating patterned, low-loss magnetic materials into microwave devices and
circuits presents many challenges due to the specific conditions that are
required to grow ferrite materials, driving the need for flip-chip and other
indirect fabrication techniques. The low-loss ($\alpha = 3.98 \pm 0.22 \times
10^{-5}$), room-temperature ferrimagnetic coordination compound vanadium
tetracyanoethylene ($\mathrm{V[TCNE]}_x$) is a promising new material for these
applications that is potentially compatible with semiconductor processing. Here
we present the deposition, patterning, and characterization of
$\mathrm{V[TCNE]}_x$ thin films with lateral dimensions ranging from 1 micron
to several millimeters. We employ electron-beam lithography and liftoff using
an aluminum encapsulated poly(methyl methacrylate), poly(methyl
methacrylate-methacrylic acid) copolymer bilayer (PMMA/P(MMA-MAA)) on sapphire
and silicon. This process can be trivially extended to other common
semiconductor substrates. Films patterned via this method maintain low-loss
characteristics down to 25 microns with only a factor of 2 increase down to 5
microns. A rich structure of thickness and radially confined spin-wave modes
reveals the quality of the patterned films. Further fitting, simulation, and
analytic analysis provides an exchange stiffness, $A_{ex} = 2.2 \pm 0.5 \times
10^{-10}$ erg/cm, as well as insights into the mode character and surface spin
pinning. Below a micron, the deposition is non-conformal, which leads to
interesting and potentially useful changes in morphology. This work establishes
the versatility of $\mathrm{V[TCNE]}_x$ for applications requiring highly
coherent magnetic excitations ranging from microwave communication to quantum
information.",1910.05325v1
2020-08-29,Exploring a quantum-information-relevant magnonic material: Ultralow damping at low temperature in the organic ferrimagnet V[TCNE]x,"Quantum information science and engineering requires novel low-loss magnetic
materials for magnon-based quantum-coherent operations. The search for low-loss
magnetic materials, traditionally driven by applications in microwave
electronics near room-temperature, has gained additional constraints from the
need to operate at cryogenic temperatures for many applications in quantum
information science and technology. Whereas yttrium iron garnet (YIG) has been
the material of choice for decades, the emergence of molecule-based materials
with robust magnetism and ultra-low damping has opened new avenues for
exploration. Specifically, thin-films of vanadium tetracyanoethylene (V[TCNE]x)
can be patterned into the multiple, connected structures needed for hybrid
quantum elements and have shown room-temperature Gilbert damping ({\alpha} = 4
\times 10^-5) that rivals the intrinsic (bulk) damping otherwise seen only in
highly-polished YIG spheres (far more challenging to integrate into arrays).
Here, we present a comprehensive and systematic study of the low-temperature
magnetization dynamics for V[TCNE]x thin films, with implications for their
application in quantum systems. These studies reveal a temperature-driven,
strain-dependent magnetic anisotropy that compensates the thin-film shape
anisotropy, and the recovery of a magnetic resonance linewidth at 5 K that is
comparable to room-temperature values (roughly 2 G at 9.4 GHz). We can account
for these variations of the V[TCNE]x linewidth within the context of scattering
from very dilute paramagnetic impurities, and anticipate additional linewidth
narrowing as the temperature is further reduced.",2008.13061v3
2020-10-04,Magnetic field dependent cycloidal rotation in pristine and Ge doped CoCr$_2$O$_4$,"We report a soft x-ray resonant magnetic scattering study of the spin
configuration in multiferroic thin films of Co$_{0.975}$Ge$_{0.025}$Cr$_2$O$_4$
(Ge-CCO) and CoCr$_2$O$_4$ (CCO), under low- and high-magnetic fields, from 0.2
T up to 6.5 T. A characterization of Ge-CCO at a low magnetic field is
performed and the results are compared to those of pure CCO. The ferrimagnetic
phase transition temperature $T_C \approx 95$ K and the multiferroic transition
temperature $T_S \approx 27$ K in Ge-CCO are comparable to those observed in
CCO. In Ge-CCO, the ordering wave vector $\textit{(qq0)}$ observed below $T_S$
is slightly larger compared to that of CCO, and, unlike CCO, the diffraction
intensity consists of two contributions that show a dissimilar x-ray
polarization dependence. In Ge-CCO, the coercive field observed at low
temperatures was larger than the one reported for CCO. In both compounds, an
unexpected reversal of the spiral helicity and therefore the electric
polarization was observed on simply magnetic field cooling. In addition, we
find a change in the helicity as a function of momentum transfer in the
magnetic diffraction peak of Ge-CCO, indicative of the presence of multiple
magnetic spirals.",2010.01518v2
2020-10-08,Static magnetic proximity effects and spin Hall magnetoresistance in Pt/Y$_{3}$Fe$_{5}$O$_{12}$ and inverted Y$_{3}$Fe$_{5}$O$_{12}$/Pt bilayers,"The magnetic state of heavy metal Pt thin films in proximity to the
ferrimagnetic insulator Y$_{3}$Fe$_{5}$O$_{12}$ has been investigated
systematically by means of x-ray magnetic circular dichroism and x-ray resonant
magnetic reflectivity measurements combined with angle-dependent
magnetotransport studies. To reveal intermixing effects as the possible cause
for induced magnetic moments in Pt, we compare thin film heterostructures with
different order of the layer stacking and different interface properties. For
standard Pt layers on Y$_{3}$Fe$_{5}$O$_{12}$ thin films, we do not detect any
static magnetic polarization in Pt. These samples show an angle-dependent
magnetoresistance behavior, which is consistent with the established spin Hall
magnetoresistance. In contrast, for the inverted layer sequence,
Y$_{3}$Fe$_{5}$O$_{12}$ thin films grown on Pt layers, Pt displays a finite
induced magnetic moment comparable to that of all-metallic Pt/Fe bilayers. This
magnetic moment is found to originate from finite intermixing at the
Y$_{3}$Fe$_{5}$O$_{12}$/Pt interface. As a consequence, we found a complex
angle-dependent magnetoresistance indicating a superposition of the spin Hall
and the anisotropic magnetoresistance in these type of samples. Both effects
can be disentangled from each other due to their different angle dependence and
their characteristic temperature evolution.",2010.03979v1
2021-02-05,Inter-valence charge transfer and charge transport in the spinel ferrite ferromagnetic semiconductor Ru-doped CoFe$_2$O$_4$,"Inter-valence charge transfer (IVCT) is electron transfer between two metal
$M$ sites differing in oxidation states through a bridging ligand: $M^{n+1} +
M'^{m} \rightarrow M^{n} + M'^{m+1}$. It is considered that IVCT is related to
the hopping probability of electron (or the electron mobility) in solids. Since
controlling the conductivity of ferromagnetic semiconductors (FMSs) is a key
subject for the development of spintronic device applications, the manipulation
of the conductivity through IVCT may become a new approach of band engineering
in FMSs. In Ru-doped cobalt ferrite CoFe$_2$O$_4$ (CFO) that shows
ferrimagnetism and semiconducting transport properties, the reduction of the
electric resistivity is attributed to both the carrier doping caused by the Ru
substitution for Co and the increase of the carrier mobility due to
hybridization between the wide Ru $4d$ and the Fe $3d$ orbitals. The latter is
the so-called IVCT mechanism that is charge transfer between the mixed valence
Fe$^{2+}$/Fe$^{3+}$ states facilitated by bridging Ru $4d$ orbital: Fe$^{2+}$ +
Ru$^{4+}$ $\leftrightarrow$ Fe$^{3+}$ + Ru$^{3+}$. To elucidate the emergence
of the IVCT state, we have conducted x-ray absorption spectroscopy (XAS) and
resonant photoemission spectroscopy (RPES) measurements on non-doped CFO and
Co$_{0.5}$Ru$_{0.5}$Fe$_2$O$_4$ (CRFO) thin films. The observations of the XAS
and RPES spectra indicate that the presence of the mixed valence
Fe$^{2+}$/Fe$^{3+}$ state and the hybridization between the Fe $3d$ and Ru $4d$
states in the valence band. These results provide experimental evidence for the
IVCT state in CRFO, demonstrating a novel mechanism that controls the electron
mobility through hybridization between the $3d$ transition-metal cations with
intervening $4d$ states.",2102.03020v1
2021-03-24,Magnetism and Spin Dynamics in Room-Temperature van der Waals Magnet Fe$_5$GeTe$_2$,"Two-dimensional (2D) van der Waals (vdWs) materials have gathered a lot of
attention recently. However, the majority of these materials have Curie
temperatures that are well below room temperature, making it challenging to
incorporate them into device applications. In this work, we synthesized a
room-temperature vdW magnetic crystal Fe$_5$GeTe$_2$ with a Curie temperature
T$_c = 332$ K, and studied its magnetic properties by vibrating sample
magnetometry (VSM) and broadband ferromagnetic resonance (FMR) spectroscopy.
The experiments were performed with external magnetic fields applied along the
c-axis (H$\parallel$c) and the ab-plane (H$\parallel$ab), with temperatures
ranging from 300 K to 10 K. We have found a sizable Land\'e g-factor difference
between the H$\parallel$c and H$\parallel$ab cases. In both cases, the Land\'e
g-factor values deviated from g = 2. This indicates contribution of orbital
angular momentum to the magnetic moment. The FMR measurements reveal that
Fe$_5$GeTe$_2$ has a damping constant comparable to Permalloy. With reducing
temperature, the linewidth was broadened. Together with the VSM data, our
measurements indicate that Fe$_5$GeTe$_2$ transitions from ferromagnetic to
ferrimagnetic at lower temperatures. Our experiments highlight key information
regarding the magnetic state and spin scattering processes in Fe$_5$GeTe$_2$,
which promote the understanding of magnetism in Fe$_5$GeTe$_2$, leading to
implementations of Fe$_5$GeTe$_2$ based room-temperature spintronic devices.",2103.13433v2
2021-11-10,Influence of the Magnetic Sub-Lattices in the Double Perovskite Compound LaCaNiReO$_6$,"The magnetism of double perovskites is a complex phenomenon, determined from
intra- or interatomic magnetic moment interactions, and strongly influenced by
geometry. We take advantage of the complementary length and time scales of the
muon spin rotation, relaxation and resonance ($\mu^+$SR) microscopic technique
and bulk AC/DC magnetic susceptibility measurements to study the magnetic
phases of the LaCaNiReO$_6$ double perovskite. As a result we are able to
discern and report a newly found dynamic phase transition and the formation of
magnetic domains below and above the known magnetic transition of this compound
at T$_N$ = 103 K. $\mu^+$SR, serving as a local probe at crystallographic
interstitial sites, reveals a transition from a metastable ferrimagnetic
ordering below T = 103 K to a stable one below T = 30 K. The fast and slow
collective dynamic state of this system are investigated. Between 103 K < T <
230 K, the following two magnetic environments appear, a dense spin region and
a static-dilute spin region. The paramagnetic state is obtained only above T >
270 K. An evolution of the interaction between Ni and Re magnetic sublattices
in this geometrically frustrated fcc perovskite structure, is revealed as a
function of temperature and magnetic field, through the critical behaviour and
thermal evolution of microscopic and macroscopic physical quantities.",2111.05920v2
2023-08-14,Temperature Evolution of Magnon Propagation Length in Tm$_3$Fe$_5$O$_{12}$ Thin Films: Roles of Magnetic Anisotropy and Gilbert Damping,"The magnon propagation length ($\langle\xi\rangle$) of a ferro/ferrimagnet
(FM) is one of the key factors that controls the generation and propagation of
thermally-driven spin current in FM/heavy metal (HM) bilayer based
spincaloritronic devices. Theory predicts that for the FM layer,
$\langle\xi\rangle$ is inversely proportional to the Gilbert damping ($\alpha$)
and the square root of the effective magnetic anisotropy constant ($K_{\rm
eff}$). However, direct experimental evidence of this relationship is lacking.
To experimentally confirm this prediction, we employ a combination of
longitudinal spin Seebeck effect (LSSE), transverse susceptibility, and
ferromagnetic resonance experiments to investigate the temperature evolution of
$\langle\xi\rangle$ and establish its correlation with the effective magnetic
anisotropy field, $H_K^{\rm eff}$ ($\propto K_{\rm eff}$) and $\alpha$ in
Tm$_3$Fe$_5$O$_{12}$ (TmIG)/Pt bilayers. We observe concurrent drops in the
LSSE voltage and $\langle\xi\rangle$ below 200$^\circ$K in TmIG/Pt bilayers
regardless of TmIG film thickness and substrate choice and attribute it to the
noticeable increases in $H_K^{\rm eff}$ and $\alpha$ that occur within the same
temperature range. From the TmIG thickness dependence of the LSSE voltage, we
determined the temperature dependence of $\langle\xi\rangle$ and highlighted
its correlation with the temperature-dependent $H_K^{\rm eff}$ and $\alpha$ in
TmIG/Pt bilayers, which will be beneficial for the development of rare-earth
iron garnet-based efficient spincaloritronic nanodevices.",2308.07236v3
2024-02-19,Magnetic anisotropy and GGG substrate stray field in YIG films down to millikelvin temperatures,"Quantum magnonics investigates the quantum-mechanical properties of magnons
such as quantum coherence or entanglement for solid-state quantum information
technologies at the nanoscale. The most promising material for quantum
magnonics is the ferrimagnetic yttrium iron garnet (YIG), which hosts magnons
with the longest lifetimes. YIG films of the highest quality are grown on a
paramagnetic gadolinium gallium garnet (GGG) substrate. The literature has
reported that ferromagnetic resonance (FMR) frequencies of YIG/GGG decrease at
temperatures below 50 K despite the increase in YIG magnetization. We
investigated a 97 nm-thick YIG film grown on 500 $\mathrm{\mu}$m-thick GGG
substrate through a series of experiments conducted at temperatures as low as
30 mK, and using both analytical and numerical methods. Our findings suggest
that the primary factor contributing to the FMR frequency shift is the stray
magnetic field created by the partially magnetized GGG substrate. This stray
field is antiparallel to the applied external field and is highly
inhomogeneous, reaching up to 40 mT in the center of the sample. At
temperatures below 500 mK, the GGG field exhibits a saturation that cannot be
described by the standard Brillouin function for a paramagnet. Including the
calculated GGG field in the analysis of the FMR frequency versus temperature
dependence allowed the determination of the cubic and uniaxial anisotropies. We
find that the total anisotropy increases more than three times with the
decrease in temperature down to 2 K. Our findings enable accurate predictions
of the YIG/GGG magnetic systems behavior at low and ultra-low millikelvin
temperatures, crucial for developing quantum magnonic devices.",2402.12112v1
2019-11-13,Unveiling domain wall dynamics of ferrimagnets in thermal magnon currents: competition of angular momentum transfer and entropic torque,"Control of magnetic domain wall motion holds promise for efficient
manipulation and transfer of magnetically stored information. Thermal magnon
currents, generated by temperature gradients, can be used to move magnetic
textures, from domain walls, to magnetic vortices and skyrmions. In the last
years, theoretical studies have centered in ferro- and antiferromagnetic spin
structures, where domain walls always move towards the hotter end of the
thermal gradient. Here we perform numerical studies using atomistic spin
dynamics simulations and complementary analytical calculations to derive an
equation of motion for the domain wall velocity. We demonstrate that in
ferrimagnets, domain wall motion under thermal magnon currents shows a much
richer dynamics. Below the Walker breakdown, we find that the temperature
gradient always pulls the domain wall towards the hot end by minimizating its
free energy, in agreement with the observations for ferro- and antiferromagnets
in the same regime. Above Walker breakdown, the ferrimagnetic domain wall can
show the opposite, counterintuitive behavior of moving towards the cold end. We
show that in this case, the motion to the hotter or the colder ends is driven
by angular momentum transfer and therefore strongly related to the angular
momentum compensation temperature, a unique property of ferrimagnets where the
intrinsic angular momentum of the ferrimagnet is zero while the sublattice
angular momentum remains finite. In particular, we find that below the
compensation temperature the wall moves towards the cold end, whereas above it,
towards the hot end. Moreover, we find that for ferrimagnets, there is a torque
compensation temperature at which the domain wall dynamics shows similar
characteristics to antiferromagnets, that is, quasi-inertia-free motion and the
absence of Walker breakdown.",1911.05393v1
1997-01-10,Macroscopic Quantum Coherence in Ferrimagnets,"We study macroscopic quantum coherence (MQC) in small ferrimagnets. Through
semi-classical calculations we show that even a small uncompensated moment has
a drastic effect on MQC. In particular, there is a rapid crossover to a regime
where the MQC tunnel splitting is equal to that obtained for a ferromagnet,
even though the system is still an antiferromagnet for all other aspects. We
calculate this tunnel splitting via instanton methods and compare it with
numerical evaluations. As an application we re-examine the experimental
evidence for MQC in ferritin and show that even though the uncompensated moment
of ferritin is small it greatly modifies the MQC behavior. We also discuss the
implications of our results for MQC in molecular magnets.",9701070v1
1997-10-27,Thermodynamic Properties of Heisenberg Ferrimagnetic Spin Chains: Ferromagnetic-Antiferromagnetic Crossover,"We study thermodynamic properties of the one-dimensional Heisenberg
ferrimagnet with antiferromagnetically exchange-coupled two kinds of spins 1
and 1/2. The specific heat and the magnetic susceptibility are calculated
employing a modified spin-wave theory as well as a quantum Monte Carlo method.
The specific heat is in proportion to $T^{1/2}$ at low enough temperatures but
shows a Schottky-like peak at mid temperatures. The susceptibility diverges as
$T^{-2}$. We reveal that at low temperatures the model is regarded as a
ferromagnet, while at mid temperatures it behaves like a gapped
antiferromagnet.",9710291v2
1997-12-26,Quantum Tunneling in Ferrimagnetic Nanoparticles Coupled to a Spin Bath: An Effective Hamiltonian,"An effective Hamiltonian, describing quantum tunneling in ferrimagnetic
nanoparticles which includes interactions between the electronic spins of
nanoparticle and microscopic environmental spins (like nuclear spins or
paramagnetic impurities), is obtained. Two limiting cases, describing tunneling
in antiferromagnetic and ferromagnetic regimes are considered, and criterion
for the transition between the two regimes is found. The validity of analytic
results is verified by the exact diagonalization method.",9712302v1
1998-05-28,"Thermodynamics of the (1,1/2) Ferrimagnet in Finite Magnetic Fields","We investigate the specific heat and magnetisation of a ferrimagnet with gS=1
and S=1/2 spins in a finite magnetic field using the transfer matrix DMRG down
to T=0.025J. Ferromagnetic gapless and antiferromagnetic gapped excitations for
H=0 lead to rich thermodynamics for H > 0. While the specific heat is
characterized by a generic double peak structure, magnetisation reveals two
critical fields, Hc1=1.76(1) and Hc2=3.00(1) with square-root behaviour in the
T=0 magnetisation. Simple analytical arguments allow to understand these
experimentally accessible findings.",9805376v1
1998-06-28,Combination of Ferromagnetic and Antiferromagnetic Features in Heisenberg Ferrimagnets,"We investigate the thermodynamic properties of Heisenberg ferrimagnetic
mixed-spin chains both numerically and analytically with particular emphasis on
the combination of ferromagnetic and antiferromagnetic features. Employing a
new density-matrix renormalization-group technique as well as a quantum Monte
Carlo method, we reveal the overall thermal behavior: At very low temperatures,
the specific heat and the magnetic susceptibility times temperature behave like
$T^{1/2}$ and $T^{-1}$, respectively, whereas at intermediate temperatures,
they exhibit a Schottky-like peak and a minimum, respectively. Developing the
modified spin-wave theory, we complement the numerical findings and give a
precise estimate of the low-temperature behavior.",9806344v1
1998-10-09,Low-Energy Structure of Heisenberg Ferrimagnetic Spin Chains,"Static and dynamic structure factors of Heisenberg ferrimagnetic spin chains
are numerically investigated. There exist two distinct branches of elementary
excitations, which exhibit ferromagnetic and antiferromagnetic aspects. The
ferromagnetic feature is smeared out with the increase of temperature, whereas
the antiferromagnetic one persists up to higher temperatures. The scattering
intensity is remarkably large at lower boundaries of the ferromagnetic and
antiferromagnetic spectra. All these observations are consistent with the
ferromagnetic-to-antiferromagnetic crossover in the thermal behavior which has
recently been reported.",9810113v1
1999-01-24,Half-Metallic Ferrimagnetism in Mn_2VAl,"We show that Mn_2VAl is a compound for which the generalized gradient
approximation (GGA) to the exchange-correlation functional in density
functional theory makes a qualitative change in predicted behavior compared to
the usual local density approximation (LDA). Application of GGA leads to
prediction of Mn_2VAl being a half-metallic ferrimagnet, with the minority
channel being the conducting one. The electronic and magnetic structure is
analyzed and contrasted with the isostructural enhanced semimetal Fe_2VAl.",9901253v2
1999-12-18,Nuclear spin relaxation in ordered bimetallic chain compounds,"A theoretical interpretation is given to recent proton spin relaxation-time
(T_1) measurements on NiCu(C_7H_6N_2O_6)(H_2O)_3$\cdot$2H_2O, which is an ideal
one-dimensional ferrimagnetic Heisenberg model system of alternating spins 1
and 1/2. The relaxation rate T_1^{-1} is formulated in temrs of the spin-wave
theory and is evaluated by the use of a quantum Monte Carlo method.
Calculations of the temperature and applied-field (H) dependences of T_1^{-1}
are in total agreement with the experimental findings. T_1 behaves as
$T_1^{-1}\propto H^{-1/2}$, which turns out an indirect observation of the
quadratic dispersion relations dominating the low-energy physics of quantum
ferrimagnets.",9912340v1
2000-05-15,Multi-plateau magnetization curves of one-dimensional Heisenberg ferrimagnets,"Ground-state magnetization curves of ferrimagnetic Heisenberg chains of
alternating spins $S$ and $s$ are numerically investigated. Calculating several
cases of $(S,s)$, we conclude that the spin-$(S,s)$ chain generally exhibits
$2s$ magnetization plateaux even at the most symmetric point. In the double- or
more-plateau structure, the initial plateau is generated on a classical basis,
whereas the higher ones are based on a quantum mechanism.",0005248v1
2002-10-14,Phase diagram and influence of defects in the double perovskites,"The phase diagram of the double perovskites of the type Sr_{2-x} La_x Fe Mo
O_6 is analyzed, with and without disorder due to antisites. In addition to an
homogeneous half metallic ferrimagnetic phase in the absence of doping and
disorder, we find antiferromagnetic phases at large dopings, and other
ferrimagnetic phases with lower saturation magnetization, in the presence of
disorder.",0210303v2
2002-10-29,Dynamical Mean Field Theory of Double Perovskite Ferrimagnets,"The dynamical mean field method is used to analyze the magnetic transition
temperature and optical conductivity of a model for the ferrimagnetic double
perovskites such as $Sr_2FeMoO_6$. The calculated transition temperatures and
optical conductivities are found to depend sensitively on the band structure.
For parameters consistent with local spin density approximation band
calculations, the computed transition temperatures are lower than observed, and
in particular decrease dramatically as band filling is increased, in
contradiction to experiment. Band parameters which would increase the
transition temperature are identified.",0210627v1
2003-04-15,Shape and surface anisotropy effects on the hysteresis of ferrimagnetic nanoparticles,"We present the results of Monte Carlo simulations of a model of a single
maghemite ferrimagnetic nanoparticle with the aim to clarify the role played by
the increased anisotropy at the surface and by the shape (spherical or
elliptical) of the particle on the magnetization processes at low temperatures.
The formation of hedgehog-like structures for high enough surface anisotropy is
responsible for a change in the reversal mechanism of the particles.",0304330v1
2004-04-10,Nuclear Spin-Lattice Relaxation in One-Dimensional Heisenberg Ferrimagnets: Three-Magnon versus Raman Processes,"Nuclear spin-lattice relaxation in one-dimensional Heisenberg ferrimagnets is
studied by means of a modified spin-wave theory. We consider the second-order
process, where a nuclear spin flip induces virtual spin waves which are then
scattered thermally via the four-magnon exchange interaction, as well as the
first-order process, where a nuclear spin directly interacts with spin waves
via the hyperfine interaction. We point out a possibility of the three-magnon
relaxation process predominating over the Raman one and suggest model
experiments.",0404243v2
2005-06-27,Spin-lattice coupling in the ferrimagnetic semiconductor FeCr2S4 probed by surface acoustic waves,"Using surface acoustic waves, the elastomagnetic coupling could be studied in
thin single crystalline plates of the ferrimagnetic semiconductor FeCr2S4 by
measuring the attenuation and the frequency tracking in the temperature range
4.2 K to 200 K. The data clearly display the anomalies found in low-field
magnetization measurements.",0506702v1
2005-07-20,Persistent spin current in mesoscopic ferrimagnetic spin ring,"Using a semiclassical approach, we study the persistent magnetization current
of a mesoscopic ferrimagnetic ring in a nonuniform magnetic field. At zero
temperature, there exists persistent spin current because of the quantum
fluctuation of magnons, similar to the case of an antiferromagnetic spin ring.
At low temperature, the current shows activation behavior because of the
field-induced gap. At higher temperature, the magnitude of the spin current is
proportional to temperature T, similar to the reported result of a
ferromagnetic spin ring.",0507467v2
2006-03-13,Phase transitions in random magnetic bilayer,"The influence of random interlayer exchange on the phase states of the
simplest magnetic heterostructure consisting of two ferromagnetic Ising layers
with large interaction radius is studied. It is shown that such system can
exist in three magnetic phases: ferromagnetic, antiferromagnetic and
ferrimagnetic. The possible phase diagrams and temperature dependencies of
thermodynamic parameters are described. The regions of existence of the
magnetic phases in external magnetic field are determined at zero temperature.",0603347v3
2006-05-06,Evidence for multimagnon-mediated nuclear spin relaxation in the intertwining double-cain ferrimagnet $Ca_3 Cu_3 (PO_4)_4$,"The nuclear spin-lattice relaxation time $T_1$ of $^{31}P$ nuclei in the
title compound is measured for the first time and interpreted in terms of a
modified spin-wave theory. We establish a novel scenario for one-dimensional
ferrimagnetic spin dynamics -- it is three-magnon processes enhanced by
exchange scattering, rather than Raman processes, that make the major
contribution to $1/T_1$.",0605157v2
2006-09-12,Phase diagram of frustrated mixed-spin ladders in the strong-coupling limit,"We study the ground-state properties of frustrated Heisenberg ferrimagnetic
ladders with antiferromagnetic exchange interactions and two types of
alternating sublattice spins. In the limit of strong rung couplings, we show
that the mixed spin-1/2 and spin-1 ladders can be systematically mapped onto a
spin-1/2 Heisenberg model with additional next-nearest-neighbor exchanges. The
system is either in a ferrimagnetic state or in a critical spin-liquid state
depending on the competition between the spin exchanges along the legs and the
diagonal exchanges.",0609269v2
1995-03-07,On ferrimagnetic phases in chiral Yukawa models,"We discuss the phase structure of chiral Yukawa models in the mean-field
approximation. In particular, we examine under which conditions a ferrimagnetic
phase appears, by calculating the slopes of possible second order phase
transition lines near a critical point. Our results contrast with some
statements which appeared in the literature recently.",9503006v1
2007-06-06,Peculiar Ferrimagnetism Associated with Charge Order in Layered Perovskite GdBaMn2O5,"The magnetic properties of GdBaMn_{2}O_{5.0}, which exhibits charge ordering,
are studied from 2 to 400 K using single crystals. In a small magnetic field
applied along the easy axis, the magnetization M shows a temperature-induced
reversal which is sometimes found in ferrimagnets. In a large magnetic field,
on the other hand, a sharp change in the slope of M(T) coming from an unusual
turnabout of the magnetization of the Mn sublattices is observed. Those
observations are essentially explained by a molecular field theory which
highlights the role of delicate magnetic interactions between Gd^{3+} ions and
the antiferromagnetically coupled Mn^{2+}/Mn^{3+} sublattices.",0706.0749v1
2007-07-14,"Martensitic transition, ferrimagnetism and Fermi surface nesting in Mn_2NiGa","The electronic structure of Mn_2NiGa has been studied using density
functional theory and photoemission spectroscopy. The lower temperature
tetragonal martensitic phase with c/a= 1.25 is more stable compared to the
higher temperature austenitic phase. Mn_2NiGa is ferrimagnetic in both phases.
The calculated valence band spectrum, the optimized lattice constants and the
magnetic moments are in good agreement with experiment. The majority-spin Fermi
surface (FS) expands in the martensitic phase, while the minority-spin FS
shrinks. FS nesting indicates occurrence of phonon softening and modulation in
the martensitic phase.",0707.2133v2
2008-08-28,Inhomogeneous ferrimagnetic-like behavior in Gd2/3Ca1/3MnO3 single crystals,"We present a study of the magnetic properties of Gd2/3Ca1/3MnO3 single
crystals at low temperatures. We show that this material behave as an
inhomogeneous ferrimagnet. In addition to small saturation magnetization at 5
K, we have found history dependent effects in the magnetization and the
presence of exchange bias. These features are compatible with microscopic phase
separation in the clean Gd2/3Ca1/3MnO3 system studied.",0808.3922v1
2008-12-19,Origin of the Ising Ferrimagnetism and Spin-Charge Coupling in LuFe2O4,"The spin ordering and spin-charge coupling in LuFe2O4 were investigated on
the basis of density functional calculations and Monte Carlo simulations. The
2:1 ferrimagnetism arises from the strong antiferromagnetic intra-sheet
Fe3+-Fe3+ and Fe3+ -Fe2+ as well as some substantial antiferromagnetic
Fe2+-Fe3+ inter-sheet spin exchange interactions. The giant magnetocapacitance
at room temperature and the enhanced electric polarization at 240 K of LuFe2O4
are explained by the strong spin-charge coupling.",0812.3897v1
2009-02-18,Majority-spin non-quasiparticle states in half-metallic ferrimagnet Mn$_2$VAl,"The density of non-quasiparticle states in the ferrimagnetic full-Heuslers
Mn$_2$VAl alloy is calculated from first principles upon appropriate inclusion
of correlations. In contrast to most half-metallic compounds, this material
displays an energy gap in the majority-spin spectrum. For this situation,
non-quasiparticle states are located below the Fermi level, and should be
detectable by spin-polarized photoemission. This opens a new way to study
many-body effects in spintronic-related materials.",0902.3109v1
2009-07-08,Magnetic hysteresis in a molecular Ising ferrimagnet: Glauber dynamics approach,"Motivated by recent experimental results reporting giant coercive fields in
Co(II)-based molecular magnets we present a theory of hysteresis phenomena
based on the Glauber stochastic dynamics. Unusual form of hysteresis loops is
similar to those of found in Co-based quasi-one-dimensional ferrimagnet CoPhOMe
at low temperatures. Temperature dependence of the coercive field has a
characteristic form with an inflection that may serve as an indicator of the
Glauber dynamics in real compounds. A relevance of the model for other Co-based
molecular magnets is discussed.",0907.1348v1
2009-09-11,Spin models of quasi-1D quantum ferrimagnets with competing interactions,"We present a brief survey of the recent theoretical work related to generic
Heisenberg spin models describing quasi-one-dimensional quantum ferrimagnets.
The emphasis is on quantum chains and ladders with strong competing
interactions, such as the frustrated $J_1-J_2$ chain with alternating (1,1/2)
spins, the spin-1/2 diamond chain with four-spin cyclic couplings, and some
generic types of mixed-spin ladders with geometric frustration. As a rule,
discussed models exhibit rich quantum phase diagrams and provide some
interesting examples of one-dimensional magnetic-paramagnetic quantum phase
transitions. A number of open problems in the reviewed research area are
discussed.",0909.2182v1
2009-10-13,"Monte Carlo Study of Mixed-Spin S=(1/2,1) Ising Ferrimagnets","We investigate Ising ferrimagnets on square and simple-cubic lattices with
exchange couplings between spins of values S=1/2 and S=1 on neighbouring sites
and an additional single-site anisotropy term on the S=1 sites. Based mainly on
a careful and comprehensive Monte Carlo study, we conclude that there is no
tricritical point in the two--dimensional case, in contradiction to mean-field
predictions and recent series results. However, evidence for a tricritical
point is found in the three-dimensional case. In addition, a line of
compensation points is found for the simple-cubic, but not for the square
lattice.",0910.2377v1
2010-10-23,High spin polarization in epitaxial films of ferrimagnetic Mn3Ga,"Ferrimagnetic Mn3Ga exhibits a unique combination of low saturation
magnetization (Ms = 0.11 MA m-1) and high perpendicular anisotropy with a
uniaxial anisotropy constant of Ku = 0.89 MJ m-3. Epitaxial c-axis films
exhibit spin polarization as high as 58%, measured using point contact Andreev
reflection. These epitaxial films will be able to support thermally stable
sub-10 nm bits for spin transfer torque memories.",1010.4872v1
2010-12-23,On the derivation of the magnetocaloric properties in ferrimagnetic spinel Mn3O4,"Large magnetocaloric effect has been observed in Mn3O4 around its
ferrimagnetic transition at TN = 42.75 K. Field-induced isothermal entropy
changes (\DeltaS) were derived from both magnetic and calorimetric techniques.
The maximum |\DeltaS| and adiabatic temperature change ({\Delta}Tad) at TN are
11 J kg-1 K-1 and 1.9 K, respectively, for a magnetic field change of 20 kOe.
Moreover, it is found that the complex magnetic phase transitions taking place
below TN produce additional -but smaller- features on \DeltaS(T).",1012.5161v1
2011-09-08,Mixed Ising ferrimagnets with next-nearest neighbour couplings on square lattices,"We study Ising ferrimagnets on square lattices with antiferromagnetic
exchange couplings between spins of values S=1/2 and S=1 on neighbouring sites,
couplings between S=1 spins at next--nearest neighbour sites of the lattice,
and a single--site anisotropy term for the S=1 spins. Using mainly ground state
considerations and extensive Monte Carlo simulations, we investigate various
aspects of the phase diagram, including compensation points, critical
properties, and temperature dependent anomalies. In contrast to previous
belief, the next--nearest neighbour couplings, when being of antiferromagnetic
type, may lead to compensation points.",1109.1709v1
2013-10-30,Geometrical origin of ferrimagnetism and superparamagnetism in Fe-based double perovskite multiferroics,"We show that a superstructure of antiferromagnetically interacting Fe$^{3+}$
($S=5/2$) ions in double perovskites AFe$_{1/2}$M$_{1/2}$O$_{3}$ exhibits a
ferrimagnetic ordering below $T_{fe} \approx 5.6J_1$ ($J_1/k_B \sim 50$~K),
which is close to room temperature. Small clusters of the same structure
exhibit a superparamagnetic behavior at $T \lesssim T_{fe}$. The possibility of
formation of such clusters explains the room-temperature (superpara)magnetism
in 3$d$-metal based oxides.",1310.8079v2
2014-01-13,Room-Temperature Ferrimagnet with Frustrated Antiferroelectricity: Promising Candidate Toward Multiple State Memory,"On the basis of first-principles calculations we show that the M-type
hexaferrite BaFe12O19 exhibits frustrated antiferroelectricity associated with
its trigonal bipyramidal Fe3+ sites. The ferroelectric (FE) state of BaFe12O19,
reachable by applying an external electric field to the antiferroelectric (AFE)
state, can be made stable at room temperature by appropriate element
substitution or strain engineering. Thus M-type hexaferrite, as a new type of
multiferoic with coexistence of antiferroelectricity and ferrimagnetism,
provide a basis for studying the phenomenon of frustrated antiferroelectricity
and realizing multiple state memory devices.",1401.2747v1
2014-10-21,Magnetic switching dynamics in a ferrimagnetic two sub-lattice model including ultrafast exchange scattering,"We study the heat-induced magnetization dynamics in a toy model of a
ferrimagnetic alloy, which includes localized spins antiferromagnetically
coupled to an itinerant carrier system with a Stoner gap. We determine the
one-particle spin-density matrix including exchange scattering between
localized and itinerant bands as well as scattering with phonons. While a
transient ferromagnetic-like state can always be achieved by a sufficiently
strong excitation, this transient ferromagnetic-like state only leads to
magnetization switching for model parameters that also yield a compensation
point in the equilibrium M(T) curve.",1410.5745v2
2016-09-07,Magnetodielectric and spin-lattice coupling in quasi 1D Ising spin chain CoNb$_{2}$O$_{6}$,"We have studied magnetodielectric and spin-lattice coupling in
CoNb$_{2}$O$_{6}$ single crystals. Magnetostriction and magnetodielectric
experiments are performed at temperatures in and above antifferomagnetic phase
of quasi 1D Ising spin chain CoNb$_{2}$O$_{6}$. Field induced magnetic
transitions are clearly reflected in magnetodielectric measurement as well as
magnetostriction measurement also. Two sharp anomalies are found around the
critical fields of antiferromagnetic to ferrimagnetic transition and
ferrimagnetic to saturated paramagnetic transition in both magnetodielectric
and magnetostriction experiments. High field anomaly is more pronounced for
magnetodielectric response and magnetostriction also. So, in CoNb$_{2}$O$_{6}$,
spins are strongly coupled with lattice as well as charges also.",1609.02048v1
2017-03-15,Modeling ultrafast all-optical switching in synthetic ferrimagnets,"Based on numerical simulations, we demonstrate thermally induced magnetic
switching in synthetic ferrimagnets composed of multilayers of rare-earth and
transition metals. Our findings show that deterministic magnetization reversal
occurs above a certain threshold temperature if the ratio of transition metal
atoms to rare-earth atoms is sufficiently large. Surprisingly, the total
thickness of the multilayer system has little effect on the occurence of
switching. We further provide a simple argument to explain the temperature
dependence of the reversal process.",1703.05220v1
2018-11-16,Ferrimagnetic organelles in multicellular organisms,"In this paper, it was revealed by means of methods of atomic force microscopy
and magnetic force microscopy that the biogenic magnetic nanoparticles are
localized in the form of chains in the walls of the capillaries of animals and
the walls of the conducting tissue of plants and fungi. The biogenic magnetic
nanoparticles are part of the transport system in multicellular organisms. In
this connection, a new idea of function of biogenic magnetic nanoparticles is
discussed in the paper that the chains of biogenic magnetic nanoparticles
represent a ferrimagnetic organelles of a specific purpose.",1811.06717v1
2013-08-01,Exchange relaxation as the mechanism of ultrafast spin reorientation in two-sublattice ferrimagnets,"In the exchange approximation, an exact solution is obtained for the
sublattice magnetizations evolution in a two-sublattice ferrimagnet. Nonlinear
regimes of spin dynamics are found that include both the longitudinal and
precessional evolution of the sublattice magnetizations, with the account taken
of the exchange relaxation. In particular, those regimes describe the spin
switching observed in the GdFeCo alloy under the influence of a femtosecond
laser pulse.",1308.0203v1
2014-03-03,CaBaCo$_4$O$_7$ : A ferrimagnetic pyroelectric,"Magneto-electric coupling in pyroelectric CaBaCo$_4$O$_7$ is investigated
using ab-intio calculations and Landau theory. The former shows that
exchange-striction is strong enough to produce a giant change in electric
polarization upon ferrimagnetic ordering, comparable to the experimentally
determined value of ~17 mC/m$^2$ . Furthermore, Landau theory demonstrates that
magneto-elastic coupling in CaBaCo$_4$O$_7$ is responsible for the strong
magneto-electric coupling appearing close to the magnetic phase transition.",1403.0614v1
2017-04-17,Strain-magneto-optics of a magnetostrictive ferrimagnet CoFe2O4,"We experimentally demonstrate that in magnetostrictive ferrimagnetic single
crystal of CoFe2O4 there is clear correlation between magnetostriction and
magnetoreflection of unpolarized light in the infrared range. The influence of
magnetic field on specular reflection is likely to be indirect: application of
a magnetic field results in strong strain and deformation of the crystal
lattice, which leads to the change in electron energy structure and hence
reflection spectrum.",1704.04890v1
2012-01-10,Direct observation of magnetic phase coexistence and magnetization reversal in a Gd$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thin film,"We have investigated the ferrimagnetic domain structure in a
Gd$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thin film using magnetic force microscopy. We
observe clear signs of phase separation, with magnetic islands embedded in a
non-magnetic matrix. We also directly visualize the reversal of magnetization
of ferrimagnetic domains as a function of temperature and attribute it to a
change in the balance of magnetization of anti-aligned Mn and Gd sublattices.",1201.2144v1
2014-06-07,Interface-dependent magnetotransport properties for thin Pt films on ferrimagnetic Y3Fe5O12,"We have studied magnetoresistance and Hall effects for 1.8-nm-thick Pt films
grown on a ferrimagnetic insulator Y3Fe5O12 in a wide temperature (0.46-300 K)
and magnetic-field (-15-15 T) region. In the low-temperature regime where
quantum corrections to conductivity are observed, weak antilocalization
behavior observed in Pt films is critically suppressed when the film is
attached to Y3Fe5O12. Hall resistance in the Pt film is also affected by
Y3Fe5O12, and it exhibits logarithmic temperature dependence in a broad
temperature range. The magnetotransport properties in the high-field range are
significantly influenced by the interface between Pt and Y3Fe5O12.",1406.1859v1
2017-12-13,Theoretical Proposal for Determining Angular Momentum Compensation in Ferrimagnets,"This work demonstrates that the magnetization and angular momentum
compensation temperature (TMC and TAMC) in ferrimagnets (FiM) can be
unambiguously determined by performing two sets of temperature dependent
current switching, with the symmetry reverses at TMC and TAMC, respectively. A
theoretical model based on the modified Landau-Lifshitz-Bloch equation is
developed to systematically study the spin torque effect under different
temperatures, and numerical simulations are performed to corroborate our
proposal. Furthermore, we demonstrate that the recently reported linear
relation between TAMC and TMC can be explained using the Curie-Weiss theory.",1712.04624v1
2017-12-15,Effect of the Canting of Local Anisotropy Axes on Ground-State Properties of a Ferrimagnetic Chain with Regularly Alternating Ising and Heisenberg Spins,"The effect of the canting of local anisotropy axes on the ground-state phase
diagram and magnetization of a ferrimagnetic chain with regularly alternating
Ising and Heisenberg spins is exactly examined in an arbitrarily oriented
magnetic field. It is shown that individual contributions of Ising and
Heisenberg spins to the total magnetization basically depend on the spatial
orientation of the magnetic field and the canting angle between two different
local anisotropy axes of the Ising spins.",1712.05622v1
2018-10-01,Trimers of MnO6 octahedra and ferrimagnetism of Ba4NbMn3O12,"Ba4NbMn3O12 is reported, synthesized by a solid state method in air. The
crystal structure, determined by performing refinements on room temperature
powder X-ray diffraction data by the Rietveld method, consists of Mn3O12
trimers in the configuration of three face-sharing MnO6 octahedra, with the
trimers arranged in triangular planes. An effective moment of 4.82 {\mu}B/f.u
is observed and competing antiferromagnetic and ferromagnetic interactions
between Mn ions are inferred from the Weiss temperature of -4 K and the
ferrimagnetic ordering transition of approximately 42 K. Ba4NbMn3O12 is a
semiconductor with a transport activation energy of 0.37 eV.",1810.00763v1
2019-07-03,Dynamic magnetic features of a mixed ferro-ferrimagnetic ternary alloy in the form of AB$_p$C$_{1-p}$,"Dynamic magnetic features of a mixed ferro-ferrimagnetic ternary alloy in the
form of AB$_p$C$_{1-p}$, especially. The effect of Hamiltonian parameters on
the dynamic magnetic features of the system are investigated. For this aim, an
AB$_p$C$_{1-p}$ ternary alloy system was simulated within the mean-field
approximation based on a Glauber type stochastic dynamic and for simplicity, A,
B and C ions as SA = 1/2, SB = 1 and SC = 3/2, were chosen respectively. It was
found that in our dynamic system the critical temperature was always dependent
on the concentration ratio of the ternary alloy.",1907.01850v1
2021-01-14,Anomalous Hall effect in weak-itinerant ferrimagnet FeCr$_2$Te$_4$,"We carried out a comprehensive study of electronic transport, thermal and
thermodynamic properties in FeCr$_2$Te$_4$ single crystals. It exhibits
bad-metallic behavior and anomalous Hall effect (AHE) below a weak-itinerant
paramagentic-to-ferrimagnetic transition $T_c$ $\sim$ 123 K. The linear scaling
between the anomalous Hall resistivity $\rho_{xy}$ and the longitudinal
resistivity $\rho_{xx}$ implies that the AHE in FeCr$_2$Te$_4$ is most likely
dominated by extrinsic skew-scattering mechanism rather than intrinsic KL or
extrinsic side-jump mechanism, which is supported by our Berry phase
calculations.",2101.05831v1
2023-04-27,Effective Tight-Binding Model of Compensated Ferrimagnetic Weyl Semimetal with Spontaneous Orbital Magnetization,"The effective tight-binding model with compensated ferrimagnetic
inverse-Heusler lattice Ti$_{2}$MnAl, candidate material of magnetic Weyl
semimetal, is proposed. The energy spectrum near the Fermi level, the
configurations of the Weyl points, and the anomalous Hall conductivity are
calculated. We found that the orbital magnetization is finite, while the total
spin magnetization vanishes, at the energy of the Weyl points. The magnetic
moments at each site are correlated with the orbital magnetization, and can be
controlled by the external magnetic field.",2304.14009v1
2023-12-19,Evidence for coexistence of spin-glass and ferrimagnetic phases in BaFe12O19 due to basal plane freezing,"We present here the results of low-temperature magnetization and X-ray
magnetic circular dichroism studies on single crystals of BaFe12O19 which
reveal for the first time the emergence of a spin glass phase, in coexistence
with the long-range ordered ferrimagnetic phase, due to the freezing of the
basal plane spin component.",2312.11990v1
2005-10-30,Lattice expansion and non-collinear to collinear ferrimagnetic order in MnCr$_2$O$_4$ nanoparticle,"We report magnetic behaviour of MnCr$_2$O$_4$, which belongs to a special
class of spinel, known as chromite. Bulk MnCr$_2$O$_4$ shows a sequence of
magnetic states, which follows paramagnetic (PM) to collinear ferrimagnetic
(FM) state below T$_C$ $\sim$ 45 K and collinear FM state to non-collinear FM
state below T$_S$ $\sim$ 18 K. The non-collinear spin structure has been
modified on decreasing the particle size, and magnetic transition at T$_S$
decreases in nanoparticle samples. However, ferrimagnetic order is still
dominating in nanoparticles, except the observation of superparamagnetic like
blocking and decrease of spontaneous magnetization for nanoparticle. This may,
according to the core-shell model of ferrimagnetic nanoparticle, be the surface
disorder effect of nanoparticle. The system also show the increase of T$_C$ in
nanoparticle samples, which is not consistent with the core-shell model. The
analysis of the M(T) data, applying spin wave theory, has shown an unusual
Bloch exponent value 3.35 for bulk MnCr$_2$O$_4$, which decreases and
approaches to 1.5, a typical value for any standard ferromagnet, with
decreasing the particle size. MnCr$_2$O$_4$ has shown a few more unusual
behaviour. For example, lattice expansion in nanoparticle samples. The present
work demonstrates the correlation between a systematic increase of lattice
parameter and the gradual decrease of B site non-collinear spin structure in
the light of magnetism of MnCr$_2$O$_4$ nanoparticles.",0510814v1
2011-07-26,Magnetic Behaviour of Disordered Ising Ferrimagnet in High Magnetic Field,"The magnetic behaviour of a disordered ferrimagnetic system Ap B1-p where
both A and B represent the magnetic atoms with respective spin SA = 1/2 and SB
= 1 in presence of high magnetic field is treated theoretically.Assuming the
magnetic interaction can be described through Ising Hamiltonian the approximate
free energy is obtained using the cluster-variational method. The field
dependence of the magnetization is then obtained for different concentration p
and exchange parameters (JAA, JBB and JAB). For p = 0.5,the magnetization M in
ferrimagnetic state and in absence of compensation temperature Tcm vanishes at
TC.Field induced reversal of M is found at switching temperature TS (<TC) which
is decreasing function of field H.A maximum in M is found above TS and the
maximum value of M increases with field.In ferrimagnetic state M increases
almost linearly at high H region. For system with large ferromagnetic JAA,the
compensation temperature Tcm is increasing function of JBB and JAB .The
decrease in compensation temperature is linear at small field and tends to
saturate at higher field.The sharpness of the magnetization reversal is
increased with H.For fully compensated state of the system with p = 2/3,the
magnetization in presence of H also exhibits switching behaviour at TS .For p =
0.2 the field induced reversal of magnetization occurs more sharply.The
orientational switching of the sublattice magnetization MA and MB with field
increases the Zeeman energy and is the origin of magnetization reversal at Ts",1107.5225v1
2012-03-28,"Geometric and disorder -- type magnetic frustration in ferrimagnetic ""114"" Ferrites: Role of diamagnetic Li+ and Zn2+ cation substitution","The comparative study of the substitution of zinc and lithium for iron in the
""114"" ferrites, YBaFe4O7 and CaBaFe4O7, shows that these diamagnetic cations
play a major role in tuning the competition between ferrimagnetism and magnetic
frustration in these oxides. The substitution of Li or Zn for Fe in the cubic
phase YBaFe4O7 leads to a structural transition to a hexagonal phase
YBaFe4-xMxO7, for M = Li (0.30 < x < 0.75) and for M = Zn (0.40 < x < 1.50). It
is seen that for low doping values i.e. x = 0.30 (for Li) and x = 0.40 (for
Zn), these diamagnetic cations induce a strong ferrimagnetic component in the
samples, in contrast to the spin glass behaviour of the cubic phase. In all the
hexagonal phases, YBaFe4-xMxO7 and CaBaFe4-xMxO7 with M = Li and Zn, it is seen
that in the low doping regime (x ~ 0.3 to 0.5), the competition between
ferrimagnetism and 2 D magnetic frustration is dominated by the average valency
of iron. In contrast, in the high doping regime (x ~ 1.5), the emergence of a
spin glass is controlled by the high degree of cationic disorder, irrespective
of the iron valency.",1203.6220v1
2013-03-22,Linear perturbation renormalization group method for Ising-like spin systems,"The linear perturbation group transformation (LPRG) is used to study the
thermodynamics of the axial next-nearest-neighbor Ising model with four spin
interactions (extended ANNNI) in a field. The LPRG for weakly interacting Ising
chains is presented. The method is used to study finite field
para-ferrimagnetic phase transitions observed in layered uranium compounds,
UAs_{1-x}Se_x, UPd_2Si_2 or UNi_2Si_2. The above-mentioned systems are made of
ferromagnetic layers and the spins from the nearest-neighbor and
next-nearest-neighbor layers are coupled by the antiferromagnetic interactions
J_1<0 and J_2<0, respectively. Each of these systems exhibits a triple point in
which two ordered phases (ferrimagnetic and incommensurate) meet the
paramagnetic one, and all undergo the high field phase transition from para- to
ferrimagnetic (++-) phase. However, if in UAs_{1-x}Se_x the para-ferri phase
transition is of the first order as expected from the symmetry reason, in
UT_2Si_2 (T=Pd,Ni) this transition seems to be a continuous one, at least in
the vicinity of the multicritical point. Within the MFA, the critical character
of the finite field para-ferrimagnetic transition at least at one isolated
point can be described by the ANNNI model supplemented by an additional, e.g.,
four-spin interaction. However, in LPRG approximation for the ratio
\kappa=J_2/J_1 around 0.5 there is a critical value of the field for which an
isolated critical point also exists in the original ANNNI model. The positive
four-spin interaction shifts the critical point towards higher fields and
changes the shape of the specific heat curve. In the latter case for the fields
small enough, the specific heat exhibits two-peak structure in the paramagnetic
phase.",1303.5585v1
2016-04-26,Weak localization effect in topological insulator micro flakes grown on insulating ferrimagnet BaFe12O19,"Many exotic physics anticipated in topological insulators require a gap to be
opened for their topologica surface states by breaking time reversal symmetry.
The gap opening has been achieved by doping magnetic impurities, which however
inevitably create extra carriers and disorder that undermine the electronic
transport. In contrast, the proximity to a ferromagnetic/ferrimagnetic
insulator may improve the device quality, thus promises a better way to open
the gap while minimizing the side-effects. Here, we grow thin single-crystal
Sb1.9Bi0.1Te3 micro flakes on insulating ferrimagnet BaFe12O19 by using the van
der Waals epitaxy technique. The micro flakes show a negative magnetoresistance
in weak perpendicular fields below 50 K, which can be quenched by increasing
temperature. The signature implies the weak localization effect as its origin,
which is absent in intrinsic topological insulators, unless a surface state gap
is opened. The surface state gap is estimated to be 10 meV by using the theory
of the gap-induced weak localization effect. These results indicate that the
magnetic proximity effect may open the gap for the topological surface attached
to BaM insulating ferrimagnet. This heterostructure may pave the way for the
realization of new physical effects as well as the potential applications of
spintronics devices.",1604.07534v1
2017-03-09,Magnon mode selective spin transport in compensated ferrimagnets,"We investigate the generation of magnonic thermal spin currents and their
mode selective spin transport across interfaces in insulating, compensated
ferrimagnet/normal metal bilayer systems. The spin Seebeck effect signal
exhibits a non-monotonic temperature dependence with two sign changes of the
detected voltage signals. Using different ferrimagnetic garnets, we demonstrate
the universality of the observed complex temperature dependence of the spin
Seebeck effect. To understand its origin, we systematically vary the interface
between the ferrimagnetic garnet and the metallic layer, and by using different
metal layers we establish that interface effects play a dominating role. They
do not only modify the magnitude of the spin Seebeck effect signal but in
particular also alter its temperature dependence. By varying the temperature,
we can select the dominating magnon mode and we analyze our results to reveal
the mode selective interface transmission probabilities for different magnon
modes and interfaces. The comparison of selected systems reveals
semi-quantitative details of the interfacial coupling depending on the
materials involved, supported by the obtained field dependence of the signal.",1703.03218v2
2017-03-30,Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo films,"Magnetic skyrmions are swirling magnetic textures with novel characteristics
suitable for future spintronic and topological applications. Recent studies
confirmed the room-temperature stabilization of skyrmions in ultrathin
ferromagnets. However, such ferromagnetic skyrmions show undesirable
topological effect, the skyrmion Hall effect, which leads to their
current-driven motion towards device edges, where skyrmions could easily be
annihilated by topographic defects. Recent theoretical studies have predicted
enhanced current-driven behaviour for antiferromagnetically exchange-coupled
skyrmions. Here we present the stabilization of these skyrmions and their
current-driven dynamics in ferrimagnetic GdFeCo films. By utilizing
element-specific X-ray imaging, we find that the skyrmions in the Gd and FeCo
sublayers are antiferromagnetically exchange-coupled. We further confirm that
ferrimagnetic skyrmions can move at a velocity of ~50 m s-1 with reduced
skyrmion Hall angle, {\theta}SkHE ~20{\deg}. Our findings open the door to
ferrimagnetic and antiferromagnetic skyrmionics while providing key
experimental evidences of recent theoretical studies.",1703.10310v2
2019-05-02,Strong magnetoelectric coupling in mixed ferrimagnetic-multiferroic phases of a double perovskite,"Exploring new magnetic materials is essential for finding advantageous
functional properties such as magnetoresistance, magnetocaloric effect,
spintronic functionality, and multiferroicity. Versatile classes of double
perovskite compounds have been recently investigated because of intriguing
physical properties arising from the proper combination of several magnetic
ions. In this study, it is observed that the dominant ferrimagnetic phase is
coexisted with a minor multiferroic phase in single-crystalline
double-perovskite Er2CoMnO6. The majority portion of the ferrimagnetic order is
activated by the long-range order of Er3+ moments below TEr = 10 K in addition
to the ferromagnetic order of Co2+ and Mn4+ moments arising at TC = 67 K,
characterized by compensated magnetization at TComp = 3.15 K. The inverted
magnetic hysteresis loop observed below TComp can be described by an extended
Stoner-Wohlfarth model. The additional multiferroic phase is identified by the
ferroelectric polarization of 0.9 uC/m2 at 2 K. The coexisting ferrimagnetic
and multiferroic phases appear to be strongly correlated in that metamagnetic
and ferroelectric transitions occur simultaneously. The results based on
intricate magnetic correlations and phases in Er2CoMnO6 enrich fundamental and
applied research on magnetic materials through the scope of distinct magnetic
characteristics in double perovskites.",1905.00595v1
2017-06-06,Magnetic order and interactions in ferrimagnetic Mn3Si2Te6,"The magnetism in Mn$_3$Si$_2$Te$_6$ has been investigated using thermodynamic
measurements, first principles calculations, neutron diffraction and diffuse
neutron scattering on single crystals. These data confirm that
Mn$_3$Si$_2$Te$_6$ is a ferrimagnet below a Curie temperature of $T_C$
approximately 78K. The magnetism is anisotropic, with magnetization and neutron
diffraction demonstrating that the moments lie within the basal plane of the
trigonal structure. The saturation magnetization of approximately 1.6$\mu_B$/Mn
at 5K originates from the different multiplicities of the two
antiferromagnetically-aligned Mn sites. First principles calculations reveal
antiferromagnetic exchange for the three nearest Mn-Mn pairs, which leads to a
competition between the ferrimagnetic ground state and three other magnetic
configurations. The ferrimagnetic state results from the energy associated with
the third-nearest neighbor interaction, and thus long-range interactions are
essential for the observed behavior. Diffuse magnetic scattering is observed
around the 002 Bragg reflection at 120K, which indicates the presence of strong
spin correlations well above $T_C$. These are promoted by the competing ground
states that result in a relative suppression of $T_C$, and may be associated
with a small ferromagnetic component that produces anisotropic magnetism below
$\approx$330K.",1706.01925v1
2019-06-28,Spin transport in an insulating ferrimagnetic-antiferromagnetic-ferrimagnetic trilayer as a function of temperature,"We present a study of the transport properties of thermally generated spin
currents in an insulating ferrimagnetic-antiferromagnetic-ferrimagnetic
trilayer over a wide range of temperature. Spin currents generated by the spin
Seebeck effect (SSE) in a yttrium iron garnet (YIG) YIG/NiO/YIG trilayer on a
gadolinium gallium garnet (GGG) substrate were detected using the inverse spin
Hall effect in Pt. By studying samples with different NiO thicknesses, the NiO
spin diffusion length was determined to be 4.2 nm at room temperature.
Interestingly, below 30 K, the inverse spin Hall signals are associated with
the GGG substrate. The field dependence of the signal follows a Brillouin
function for a S=7/2 spin ($\mathrm{Gd^{3+}}$) at low temperature. Sharp
changes in the SSE signal at low fields are due to switching of the YIG
magnetization. A broad peak in the SSE response was observed around 100 K,
which we associate with an increase in the spin-diffusion length in YIG. These
observations are important in understanding the generation and transport
properties of spin currents through magnetic insulators and the role of a
paramagnetic substrate in spin current generation.",1906.12288v1
2019-10-14,Ultrafast domain wall motion in ferrimagnets induced by magnetic anisotropy gradient,"The ultrafast magnetic dynamics in compensated ferrimagnets not only provides
information similar to antiferromagnetic dynamics, but more importantly opens
new opportunities for future spintronic devices [Kim et al., Nat. Mater. 16,
1187 (2017)]. One of the most essential issues for device design is searching
for low-power-consuming and high-efficient methods of controlling domain wall.
In this work, we propose to use the voltage-controlled magnetic anisotropy
gradient as an excitation source to drive the domain wall motion in
ferrimagnets. The ultrafast wall motion under the anisotropy gradient is
predicted theoretically based on the collective coordinate theory, which is
confirmed by the atomistic micromagnetic simulations. The antiferromagnetic
spin dynamics is realized at the angular momentum compensation point, and the
wall shifting has a constant speed under small gradient and can be slightly
accelerated under large gradient due to the broadened wall width during the
motion. For nonzero net angular momentum, the Walker breakdown occurs at a
critical anisotropy gradient significantly depending on the second anisotropy
and interfacial Dzyaloshinkii-Moriya interaction, which is highly appreciated
for further experiments including the materials selection and device geometry
design. More importantly, this work unveils a low-power-consuming method of
controlling the domain wall in ferrimagnets, benefiting to future spintronic
applications.",1910.05918v1
2017-11-02,A Comparative Study on Spin-Orbit Torque Efficiencies from W/ferromagnetic and W/ferrimagnetic Heterostructures,"It has been shown that W in its resistive form possesses the largest
spin-Hall ratio among all heavy transition metals, which makes it a good
candidate for generating efficient dampinglike spin-orbit torque (DL-SOT)
acting upon adjacent ferromagnetic or ferrimagnetic (FM) layer. Here we provide
a systematic study on the spin transport properties of W/FM magnetic
heterostructures with the FM layer being ferromagnetic
Co$_{20}$Fe$_{60}$B$_{20}$ or ferrimagnetic Co$_{63}$Tb$_{37}$ with
perpendicular magnetic anisotropy. The DL-SOT efficiency $|\xi_{DL}|$, which is
characterized by a current-induced hysteresis loop shift method, is found to be
correlated to the microstructure of W buffer layer in both
W/Co$_{20}$Fe$_{60}$B$_{20}$ and W/Co$_{63}$Tb$_{37}$ systems. Maximum values
of $|\xi_{DL}|\approx 0.144$ and $|\xi_{DL}|\approx 0.116$ are achieved when
the W layer is partially amorphous in the W/Co$_{20}$Fe$_{60}$B$_{20}$ and
W/Co$_{63}$Tb$_{37}$ heterostructures, respectively. Our results suggest that
the spin Hall effect from resistive phase of W can be utilized to effectively
control both ferromagnetic and ferrimagnetic layers through a DL-SOT mechanism.",1711.00630v2
2019-11-27,Spin-lattice coupling in a ferrimagnetic spinel: The exotic $H$-$T$ phase diagram of MnCr$_2$S$_4$ up to 110 T,"In antiferromagnets, the interplay of spin frustration and spin-lattice
coupling has been extensively studied as the source of complex spin patterns
and exotic magnetism. Here, we demonstrate that, although neglected in the
past, the spin-lattice coupling is essential to ferrimagnetic spinels as well.
We performed ultrahigh-field magnetization measurements up to 110 T on a
Yafet-Kittel ferrimagnetic spinel, MnCr$_2$S$_4$, which was complemented by
measurements of magnetostriction and sound velocities up to 60 T. Classical
Monte Carlo calculations were performed to identify the complex high-field spin
structures. Our minimal model incorporating spin-lattice coupling accounts for
the experimental results and corroborates the complete phase diagram, including
two new high-field phase transitions at 75 and 85 T. Magnetoelastic coupling
induces striking effects: An extremely robust magnetization plateau is embedded
between two unconventional spin-asymmetric phases. Ferrimagnetic spinels
provide a new platform to study asymmetric and multiferroic phases stabilized
by spin-lattice coupling.",1911.12103v1
2020-05-08,Sublattice magnetizations of ultrathin ferrimagnetic lamellar nanostructures between cobalt leads,"In this work we model the salient magnetic properties of the alloy lamellar
ferrimagnetic nanostructures
$[Co_{1-c}Gd_c]_{\ell^{\prime}}[Co]_\ell[Co_{1-c}Gd_c]_{\ell^{\prime}}$ between
$Co$ semi-infinite leads. We have employed the Ising spin effective field
theory (EFT) to compute the reliable magnetic exchange constants for the pure
cobalt $J_{Co-Co}$ and gadolinium $J_{Gd-Gd}$ materials, in complete agreement
with their experimental data. The sublattice magnetizations of the $Co$ and
$Gd$ sites on the individual hcp atomic (0001) planes of the $Co-Gd$ layered
nanostructures are computed for each plane and corresponding sites, by using
the combined EFT and mean field theory (MFT) spin methods. The sublattice
magnetizations, effective site magnetic moments, and ferrimagnetic compensation
characteristics for the individual hcp atomic planes of the embedded
nanostructures, are computed as a function of temperature, and for various
stable eutectic concentrations in the range $c\leq$ 0.5. The theoretical
results for the sublattice magnetizations and the local magnetic variables of
these ultrathin ferrimagnetic lamellar nanostructured systems, between cobalt
leads, are necessary for the study of their magnonic transport properties, and
eventually their spintronic dynamic computations. The method developed in this
work is general and can be applied to comparable magnetic systems
nanostructured with other materials.",2005.03965v3
2021-05-17,Fluctuation-induced ferrimagnetism in sublattice-imbalanced antiferromagnets with application to SrCu$_2$(BO$_3$)$_2$ under pressure,"We show that a collinear Heisenberg antiferromagnet, whose sublattice
symmetry is broken at the Hamiltonian level, becomes a fluctuation-induced
ferrimagnet at any finite temperature $T$ below the N\'eel temperature $T_{\rm
N}$. We demonstrate this using a layered variant of a square-lattice
$J_1$-$J_2$ model. Linear spin-wave theory is used to determine the
low-temperature behavior of the uniform magnetization, and non-linear
corrections are argued to yield a temperature-induced qualitative change of the
magnon spectrum. We then consider a layered Shastry-Sutherland model,
describing a frustrated arrangement of orthogonal dimers. This model displays
an antiferromagnetic phase for large intra-dimer couplings. A lattice
distortion which breaks the glide symmetry between the two types of dimers
corresponds to broken sublattice symmetry and hence gives rise to
ferrimagnetism. Given indications that such a distortion is present in the
material SrCu$_2$(BO$_3$)$_2$ under hydrostatic pressure, we suggest the
existence of a fluctuation-induced ferrimagnetic phase in pressurized
SrCu$_2$(BO$_3$)$_2$. We predict a non-monotonic behavior of the uniform
magnetization as function of temperature.",2105.08088v2
2021-08-24,The domain-wall motion driven by a rotating field in a ferrimagnet,"We theoretically study a ferrimagnetic domain-wall motion driven by a
rotating magnetic field. We find that, depending on the magnitude and the
frequency of the rotating field, the dynamics of a ferrimagnetic domain wall
can be classified into two regimes. First, when the frequency is lower than a
certain critical frequency set by the field magnitude, there is a stationary
solution for the domain-wall dynamics, where a domain-wall in-plane
magnetization rotates in-phase with the external field. The field-induced
precession of the domain wall gives rise to the translational motion of the
domain wall via the gyrotropic coupling between the domain-wall angle and
position. In this so-called phase-locking regime, a domain-wall velocity
increases as the frequency increases. Second, when the frequency exceeds the
critical frequency, a domain-wall angle precession is not synchronous with the
applied field. In this phase-unlocking regime, a domain wall velocity decreases
as the frequency increases. Moreover, the direction of the domain-wall motion
is found to be reversed across the angular compensation point where the net
spin density of the ferrimagnet changes its sign. Our work suggests that the
dynamics of magnetic solitons under time-varying biases may serve as platform
to study critical phenomena.",2108.10881v1
2022-02-09,Coexistence of antiferromagnetism and ferrimagnetism in adjacent honeycomb layers,"Antiferromagnetic and ferro/ferrimagnetic orders are typically exclusive in
nature, thus, their co-existence in atomic-scale proximity is expected only in
heterostructures. Breaking this paradigm and broadening the range of
unconventional magnetic states, we report here on an atomic-scale hybrid spin
state, which is stabilized in three-dimensional crystals of the polar
antiferromagnet Co$_2$Mo$_3$O$_8$ by magnetic fields applied perpendicular to
the \emph{Co} honeycomb layers and possesses a spontaneous in-plane
ferromagnetic moment. Our microscopic spin model, capturing the observed field
dependence of the longitudinal and transverse magnetization as well as the
magnetoelectric/elastic properties, reveals that this novel spin state is
composed of an alternating stacking of antiferromagnetic and ferrimagnetic
honeycomb layers. The strong intra-layer and the weak inter-layer exchange
couplings together with competing anisotropies at octahedral and tetrahedral
\emph{Co} sites are identified as the key ingredients to stabilize
antiferromagnetic and ferrimagnetic layers in such a close proximity. We show
that the proper balance of magnetic interactions can extend the stability range
of this hybrid phase down to zero magnetic field. The possibility to realize a
layer-by-layer stacking of such distinct spin orders via suitable combinations
of microscopic interactions opens a new dimension towards the nanoscale
engineering of magnetic states.",2202.04700v1
2022-02-16,Unusual ferrimagnetic ground state in rhenium ferrite,"Through comprehensive density functional calculations, we predict the
stability of a rhenium-based ferrite",2202.08115v1
2022-03-02,Emergence of insulating ferrimagnetism and perpendicular magnetic anisotropy in 3d-5d perovskite oxide composite films for insulator spintronic,"Magnetic insulators with strong perpendicular magnetic anisotropy (PMA) play
a key role in exploring pure spin current phenomena and developing
ultralow-dissipation spintronic devices, thereby it is highly desirable to
develop new material platforms. Here we report epitaxial growth of
La2/3Sr1/3MnO3 (LSMO)-SrIrO3 (SIO) composite oxide films (LSMIO) with different
crystalline orientations fabricated by sequential two-target ablation process
using pulsed laser deposition. The LSMIO films exhibit high crystalline quality
with homogeneous mixture of LSMO and SIO at atomic level. Ferrimagnetic and
insulating transport characteristics are observed, with the
temperature-dependent electric resistivity well fitted by Mott
variable-range-hopping model. Moreover, the LSMIO films show strong PMA.
Through further constructing all perovskite oxide heterostructures of the
ferrimagnetic insulator LSMIO and a strong spin-orbital coupled SIO layer,
pronounced spin Hall magnetoresistance (SMR) and spin Hall-like anomalous Hall
effect (SH-AHE) were observed. These results illustrate the potential
application of the ferrimagnetic insulator LSMIO in developing all-oxide
ultralow-dissipation spintronic devices.",2203.00818v1
2022-03-27,Giant bulk spin-orbit torque and efficient electrical switching in single ferrimagnetic FeTb layers with strong perpendicular magnetic anisotropy,"Efficient manipulation of antiferromagnetically coupled materials that are
integration-friendly and have strong perpendicular magnetic anisotropy (PMA) is
of great interest for low-power, fast, dense magnetic storage and computing.
Here, we report a distinct, giant bulk damping-like spin-orbit torque in
strong-PMA ferrimagnetic Fe100-xTbx single layers that are integration-friendly
(composition-uniform, amorphous, sputter-deposited). For sufficiently-thick
layers, this bulk torque is constant in the efficiency per unit layer
thickness, {\xi}_DL^j/t, with a record-high value of 0.036nm-1, and the
dampinglike torque efficiency {\xi}_DL^j achieves very large values for thick
layers, up to 300% for 90 nm layers. This giant bulk torque by itself switches
tens of nm thick Fe100-xTbx layers that have very strong PMA and high
coercivity at current densities as low as a few MA/cm2. Surprisingly, for a
given layer thickness, {\xi}_DL^j shows strong composition dependence and
becomes negative for composition where the total angular momentum is oriented
parallel to the magnetization rather than antiparallel. Our findings of giant
bulk spin torque efficiency and intriguing torque-compensation correlation will
stimulate study of such unique spin-orbit phenomena in a variety of
ferrimagnetic hosts. This work paves a promising avenue for developing
ultralow-power, fast, dense ferrimagnetic storage and computing devices.",2203.14193v1
2022-04-29,Entangling mechanical vibrations of two massive ferrimagnets by fully exploiting the nonlinearity of magnetostriction,"Quantum entanglement in the motion of macroscopic objects is of significance
to both fundamental studies and quantum technologies. Here we show how to
entangle the mechanical vibration modes of two massive ferrimagnets that are
placed in the same microwave cavity. Each ferrimagnet supports a magnon mode
and a low-frequency vibration mode coupled by the magnetostrictive force. The
two magnon modes are, respectively, coupled to the microwave cavity by the
magnetic dipole interaction. We first generate a stationary nonlocal entangled
state between the vibration mode of the ferrimagnet-1 and the magnon mode of
the ferrimagnet-2. This is realized by continuously driving the ferrimagnet-1
with a strong red-detuned microwave field and the entanglement is achieved by
exploiting the magnomechanical parametric down-conversion and the cavity-magnon
state-swap interaction. We then switch off the pump on the ferrimagnet-1 and,
simultaneously, turn on a red-detuned pulsed drive on the ferrimagnet-2. The
latter drive is used to activate the magnomechanical beamsplitter interaction,
which swaps the magnonic and mechanical states of the ferrimagnet-2.
Consequently, the previously generated phonon-magnon entanglement is
transferred to the mechanical modes of two ferrimagnets. The work provides a
scheme to prepare entangled states of mechanical motion of two massive objects,
which may find applications in various studies exploiting macroscopic entangled
states.",2204.14010v4
2022-06-03,Engineering the spin-orbit torque efficiency and magnetic properties of Tb/Co ferrimagnetic multilayers by stacking order,"We measured the spin-orbit torques (SOTs), current-induced switching, and
domain wall (DW) motion in synthetic ferrimagnets consisting of Co/Tb layers
with differing stacking order grown on a Pt underlayer. We find that the SOTs,
magnetic anisotropy, compensation temperature and SOT-induced switching are
highly sensitive to the stacking order of Co and Tb and to the element in
contact with Pt. Our study further shows that Tb is an efficient SOT generator
when in contact with Co, such that its position in the stack can be adjusted to
generate torques additive to those generated by Pt. With optimal stacking and
layer thickness, the dampinglike SOT efficiency reaches up to 0.3, which is
more than twice that expected from the Pt/Co bilayer. Moreover, the
magnetization can be easily switched by the injection of pulses with current
density of about 0.5-2*107A/cm2 despite the extremely high perpendicular
magnetic anisotropy barrier (up to 7.8 T). Efficient switching is due to the
combination of large SOTs and low saturation magnetization owing to the
ferrimagnetic character of the multilayers. We observed current-driven DW
motion in the absence of any external field, which is indicative of homochiral
N\'eel-type DWs stabilized by the interfacial Dzyaloshinkii-Moriya interaction.
These results show that the stacking order in transition metal/rare-earth
synthetic ferrimagnets plays a major role in determining the magnetotransport
properties relevant for spintronic applications.",2206.01586v1
2022-08-09,Hybrid spin Hall nano-oscillators based on ferromagnetic metal/ferrimagnetic insulator heterostructures,"Spin-Hall nano-oscillators (SHNOs) are promising spintronic devices to
realize current controlled GHz frequency signals in nanoscale devices for
neuromorphic computing and creating Ising systems. However, traditional SHNOs
-- devices based on transition metals -- have high auto-oscillation threshold
currents as well as low quality factors and output powers. Here we demonstrate
a new type of hybrid SHNO based on a permalloy (Py) ferromagnetic-metal
nanowire and low-damping ferrimagnetic insulator, in the form of epitaxial
lithium aluminum ferrite (LAFO) thin films. The superior characteristics of
such SHNOs are associated with the excitation of larger spin-precession angles
and volumes. We further find that the presence of the ferrimagnetic insulator
enhances the auto-oscillation amplitude of spin-wave edge modes, consistent
with our micromagnetic modeling. This hybrid SHNO expands spintronic
applications, including providing new means of coupling multiple SHNOs for
neuromorphic computing and advancing magnonics.",2208.04539v2
2023-01-19,Ab initio comparison of spin-transport properties in MgO-spaced ferrimagnetic tunnel junctions based on Mn$_3$Ga and Mn$_3$Al,"We report on first-principles spin-polarised quantum transport calculations
(from NEGF+DFT) in MgO-spaced magnetic tunnel junctions (MTJs) based on two
different Mn-based Heusler ferrimagnetic metals, namely Mn$_3$Al and Mn$_3$Ga
in their tetragonal DO$_{22}$ phase. The former is a fully compensated
half-metallic ferrimagnet, while the latter is a low-moment
high-spin-polarisation ferrimagnet, both with a small lattice mismatch from
MgO. In identical symmetric and asymmetric interface reconstructions across a
3-monolayer thick MgO barrier for both ferrimagets, the linear response
(low-voltage) spin-transfer torque (STT) and tunneling magneto-resistance (TMR)
effects are evaluated. A larger staggered in-plane STT is found in the Mn$_3$Ga
case, while the STT in Mn$_3$Al vanishes quickly away from the interface
(similarly to STT in ferromagnetic MTJs). The roles are reversed for the TMR,
which is practically 100\% in the half-metallic Mn$_3$Al-based MTJs (using the
conservative definition) as opposed to 60\% in the Mn$_3$Ga case. The weak
dependence on the exact interface reconstruction would suggest
Mn$_3$Ga-Mn$_3$Al solid solutions as a possible route towards optimal trade-off
of STT and TMR in the low-bias, low-temperature transport regime.",2301.08300v1
2023-03-30,Ferrimagnetic Regulation of Weyl Fermions in a Noncentrosymmetric Magnetic Weyl Semimetal,"The study of interaction between electromagnetism and elementary particles is
a long-standing topic in physics. Likewise, the connection between particle
physics and emergent phenomena in condensed matter physics is a recurring theme
and condensed matter physics has often provided a platform for investigating
the interplay between particles and fields in cases that have not been observed
in high-energy physics, so far. Here, using angle-resolved photoemission
spectroscopy, we provide a new example of this by visualizing the electronic
structure of a noncentrosymmetric magnetic Weyl semimetal candidate NdAlSi in
both the paramagnetic and ferrimagnetic states. We observe surface Fermi arcs
and bulk Weyl fermion dispersion as well as the regulation of Weyl fermions by
ferrimagnetism. Our results establish NdAlSi as a magnetic Weyl semimetal and
provide the first experimental observation of ferrimagnetic regulation of Weyl
fermions in condensed matter.",2303.17302v1
2023-12-04,"Ground-State Phase Diagram of (1/2,1/2,1) Mixed Diamond Chains","The ground-state phases of mixed diamond chains with ($S, \tau^{(1)},
\tau^{(2)})=(1/2,1/2,1)$, where $S$ is the magnitude of vertex spins, and
$\tau^{(1)}$ and $\tau^{(2)}$ are those of apical spins, are investigated. The
two apical spins in each unit cell are coupled by an exchange coupling
$\lambda$. The vertex spins are coupled with the top and bottom apical spins by
exchange couplings $1+\delta$ and $1-\delta$, respectively. Although this model
has an infinite number of local conservation laws for $\delta=0$, they are lost
for finite $\delta$. The ground-state phase diagram is determined using the
numerical exact diagonalization and DMRG method in addition to the analytical
approximations in various limiting cases. The phase diagram consists of a
nonmagnetic phase and several kinds of ferrimagnetic phases. We find two
different ferrimagnetic phases without spontaneous translational symmetry
breakdown. It is also found that the quantized ferrimagnetic phases with large
spatial periodicities present for $\delta=0$ are easily destroyed by small
$\delta$ and replaced by a partial ferrimagnetic phase. The nonmagnetic phase
is considered to be a gapless Tomonaga-Luttinger liquid phase based on the
recently extended Lieb-Schultz-Mattis theorem to the site-reflection invariant
spin chains and numerical diagonalization results.",2312.01630v2
1996-10-11,Matrix product states approach to the Heisenberg ferrimagnetic spin chains,"We propose a new version of the matrix product (MP) states approach to the
description of quantum spin chains, which allows one to construct MP states
with certain total spin and its z-projection. We show that previously known MP
wavefunctions for integer-spin antiferromagnetic chains and ladders correspond
to some particular cases of our general ansatz. Our method allows to describe
systems with spontaneously broken rotational symmetry, like quantum
ferrimagnetic chains whose ground state has nonzero total spin. We apply this
approach to describe the ground state properties of the isotropic ferrimagnetic
Heisenberg chain with alternating spins 1 and 1/2 and compare our variational
results with the high-precision numerical data obtained by means of the quantum
Monte Carlo (QMC) method. For both the ground state energy and the correlation
functions we obtain very good agreement between the variational results and the
QMC data.",9610097v1
1998-06-04,Compensation Temperature of a Mixed Ising Ferrimagnetic Model in the Presence of External Magnetic Fields,"The behavior of the compensation temperature of a mixed Ising ferrimagnetic
system on a square lattice in which the two interpenetrating square sublattices
have spins $\sigma$ ($\pm 1/2$) and spins $S$ ($\pm 1,0$) has been studied with
Monte Carlo methods. Our model includes nearest and next-nearest neighbor
interactions, a crystal field and an external magnetic field. This model is
relevant for understanding bimetallic molecular ferrimagnetic materials. We
found that there is a narrow range of parameters of the Hamiltonian for which
the model has compensation temperatures and that the compensation point exists
only for small values of the external field.",9806063v1
1999-04-21,Schwinger boson mean field theory of the Heisenberg Ferrimagnetic Spin Chain,"The Schwinger boson mean field theory is applied to the quantum ferrimagnetic
Heisenberg chain. There is a ferrimagnetic long range order in the ground
state. We observe two branches of the low lying excitation and calculate the
spin reduction, the gap of the antiferromagnetic branch, and the spin
fluctuation at $T=0K$. These results agree with the established numerical
results quite well. At finite temperatures, the long range order is destroyed
because of the disappearance of the Bose condensation. The thermodynamic
observables, such as the free energy, magnetic susceptibility, specific heat,
and the spin correlation at $T>0K$, are calculated. The $T\chi_{uni}$ has a
minimum at intermediate temperatures and the spin correlation length behaves as
$T^{-1}$ at low temperatures. These qualitatively agree with the numerical
results and the difference is small at low temperatures.",9904291v2
1999-12-13,Simulated nuclear spin-lattice relaxation in Heisenberg ferrimagnets: Indirect observation of quadratic dispersion relations,"In response to recent proton spin relaxation-time measurements on
NiCu(pba)(H$_2$O)$_3$$\cdot$2H$_2$O with ${pba}=1,3{-propylenebis(oxamato)}$,
which is an excellent one-dimensional ferrimagnetic Heisenberg model system of
spin-$(1,{1/2})$, we study the Raman relaxation process in spin-$(S,s)$ quantum
ferrimagnets on the assumption of predominantly dipolar hyperfine interactions
between protons and magnetic ions. The relaxation time $T_1$ is formulated
within the spin-wave theory and is estimated as a function of temperature and
an applied field $H$ by a quantum Monte Carlo method. The low-temperature
behavior of the relaxation rate $T_1^{-1}$ qualitatively varies with $(S,s)$,
while $T_1^{-1}$ is almost proportional to $H^{-1/2}$ due to the characteristic
dispersion relations.",9912211v1
2000-03-24,Magnetic Behavior of a Mixed Ising Ferrimagnetic Model in an Oscillating Magnetic Field,"The magnetic behavior of a mixed Ising ferrimagnetic system on a square
lattice, in which the two interpenetrating square sublattices have spins +- 1/2
and spins +-1,0, in the presence of an oscillating magnetic field has been
studied with Monte Carlo techniques. The model includes nearest and
next-nearest neighbor interactions, a crystal field and the oscillating
external field. By studying the hysteretic response of this model to an
oscillating field we found that it qualitatively reproduces the increasing of
the coercive field at the compensation temperature observed in real
ferrimagnets, a crucial feature for magneto-optical applications. This behavior
is basically independent of the frequency of the field and the size of the
system. The magnetic response of the system is related to a dynamical
transition from a paramagnetic to a ferromagnetic phase and to the different
temperature dependence of the relaxation times of both sublattices.",0003403v1
2000-08-10,Combined effect of frustration and dimerization in ferrimagnetic chains and square lattice,"Within the zero-temperature linear spin-wave theory we have investigated the
effect of frustration and dimerization of a Heisenberg system with alternating
spins $s_{1}$ and $s_{2}$ on one- and two-dimensional lattices. The combined
effect most visibly appears in the elementary excitation spectra. In contrast
to the ground state energy that decreases with dimerization and increases with
frustration, the excitation energies are shown to be suppressed in energy by
both dimerization and frustration. The threshold value of frustration that
signals a transition from a classical ferrimagnetic state to a spiral state,
decreases with dimerization, showing that dimerization further helps in the
phase transition. The correlation length and sublattice magnetization decrease
with both dimerization and frustration indicating the destruction of the
long-range classical ferrimagnetic. The linear spin wave theory shows that in
the case of a square lattice, dimerization initially opposes the
frustration-led transition to a spiral magnetic state, but then higher
magnitudes of lattice deformation facilitate the transition. It also shows that
the transition to spiral state is inhibited in a square lattice beyond a
certain value of dimerization.",0008165v1
2000-11-15,A Mechanism for Ferrimagnetism and Incommensurability in One-Dimensional Systems,"A mechanism for ferrimagnetism in
  (1+1)-dimensions is discussed. The ferrimagnetism is cased by interactions
described by operators with non-zero conformal spin. Such interactions appear
in such problems as the problem of tunneling between Luttinger liquids and the
problem of frustrated spin ladder. I present exact solutions for a
representative class of models containing such interactions together with a
simple mean field analysis. It is shown that the interactions (i) dynamically
generate static oscillations with a wave vector dependent on the coupling
constant, (ii) give rise to a finite magnetic moment at $T = 0$ accompanied by
the soft mode with a non-relativistic ({\it ferromagnetic}) dispersion $E \sim
k^2$, (iii) generate massive (roton) modes.",0011268v4
2001-01-12,Superfluid-spiral state of quantum ferrimagnets in magnetic field,"We study the phase diagram of one-dimensional quantum ferrimagnets by using a
numerical exact diagonalization of a finite size system along with a
field-theoretical non-linear $\sigma$ model of the quantum ferrimagnets at zero
temperature and its effective description in the presence of the external
magnetic field in terms of the quantum XY-model. The low- and the high-field
phases correspond respectively to the classical N\'eel and the fully polarized
ferromagnetic states where in the intermediate magnetic field ($h_{c1} < h <
h_{c2}$), it is an XXZ+h model with easy plane anisotropy, which possess the
spiral (superfluid) states that carry the dissipationless spin-supercurrent. We
derive the critical exponents, and then will study the stability of the XY
spiral state against these spin-supercurrents and the hard axis fluctuations.
We will show a first order phase transition from the easy plane spiral state to
a saturated ferromagnetic state occurs at $h=h_{c2}$ if the spin-supercurrent
reaches to its critical value.",0101194v1
2001-09-03,Tunnel splitting and quantum phase interference in biaxial ferrimagnetic particles at excited states,"The tunneling splitting in biaxial ferrimagnetic particles at excited states
with an explicit calculation of the prefactor of exponent is obtained in terms
of periodic instantons which are responsible for tunneling at excited states
and is shown as a function of magnetic field applied along an arbitrary
direction in the plane of hard and medium axes. Using complex time
path-integral we demonstrate the oscillation of tunnel splitting with respect
to the magnitude and the direction of the magnetic field due to the quantum
phase interference of two tunneling paths of opposite windings . The
oscillation is gradually smeared and in the end the tunnel splitting
monotonously increases with the magnitude of the magnetic field when the
direction of the magnetic field tends to the medium axis. The oscillation
behavior is similar to the recent experimental observation with Fe$_8$
molecular clusters. A candidate of possible experiments to observe the effect
of quantum phase interference in the ferrimagnetic particles is proposed.",0109016v1
2002-08-29,"Microscopic model, spin wave theory and competing orders in the double perovskites","We present a microscopic theory of carrier-induced ferrimagnetism in metallic
double perovskite compounds such as ${\rm Sr}_{2}{\rm FeMoO}_{6}$ and ${\rm
Sr}_{2}{\rm FeReO}_{6}$ which have recently attracted intense interest for
their possible applications to magnetotransport devices. The theory is based on
an effective ""Kondo-like"" Hamiltonian treated here within the large-$S$
expansion. We find that depending on the value of the carrier density the
ground state is either a ferrimagnet or a layered antiferromagnet. The
ferrimagnetic state has a robust half-metallic electronic structure. The
transition to antiferromagnetic phase is first order accompanied with the
regime of phase separation. We study spin wave spectrum including quantum
corrections and find strongly enhanced quantum effects in the vicinity of
zero-temperature phase transition.",0208586v3
2003-09-29,Novel Electronic States in Graphene Ribbons -Competing Spin and Charge Orders-,"In a nanographene ring with zigzag edges, the spin-polarized state and the
charge-polarized state are stabilized by the on-site and the nearest neighbor
Coulomb repulsions, U and V, respectively, within the extended Hubbard model
under the mean field approximation. In a Moebius strip of the nanographene with
a zigzag edge, U stabilizes two magnetic states, the domain wall state and the
helical state. Both states have ferrimagnetic spins localized along the zigzag
edge while the former connects the opposite ferrimagnetic orders resulting in a
magnetic frustration forced by the topology and the latter rotates the
ferrimagnetic spins uniformly to circumvent the frustration. The helical state
is lower in energy than the domain wall state. On the other hand, V stabilizes
another domain wall state connecting the opposite charge orders.",0309636v1
2004-04-06,Dilute ferrimagnetic semiconductors in Fe-substituted spinel ZnGa$_2$O$_4$,"Solid solutions of nominal composition
[ZnGa$_2$O$_4$]$_{1-x}$[Fe$_3$O$_4$]$_x$, of the semiconducting spinel
ZnGa$_2$O$_4$ with the ferrimagnetic spinel Fe$_3$O$_4$ have been prepared with
$x$ = 0.05, 0.10, and 0.15. All samples show evidence for long-range magnetic
ordering with ferromagnetic hysteresis at low temperatures. Magnetization as a
function of field for the $x$ = 0.15 sample is S-shaped at temperatures as high
as 200 K. M\""ossbauer spectroscopy on the $x$ = 0.15 sample confirms the
presence of Fe$^{3+}$, and spontaneous magnetization at 4.2 K. The magnetic
behavior is obtained without greatly affecting the semiconducting properties of
the host; diffuse reflectance optical spectroscopy indicates that Fe
substitution up to $x$ = 0.15 does not affect the position of the band edge
absorption. These promising results motivate the possibility of dilute
ferrimagnetic semiconductors which do not require carrier mediation of the
magnetic moment.",0404147v2
2005-12-15,"Search for half-metallic ferrimagnetism in V-based Heusler alloys Mn$_2$VZ (Z$=$Al, Ga, In, Si, Ge, Sn)","Using a state-of-the-art full-potential electronic structure method within
the local spin density approximation, we study the electronic and magnetic
structure of Mn$_2$V-based full Heusler alloys: Mn$_2$VZ (Z=Al, Ga, In, Si, Ge,
and Sn). We show that small expansion of the calculated theoretical equilibrium
lattice constants restores the half-metallic ferrimagnetism in these compounds.
Moreover a small degree of disorder between the V and Z atoms, although iduces
some states within the gap, it preserves the Slater-Pauling behaviour of the
spin magnetic moments and the alloys keep a high degree of spin-polarisation at
the Fermi level opening the way for a half-metallic compensated ferrimagnet.",0512361v1
2006-01-22,Thermodynamic properties of the ferrimagnetic spin chains in the presence of a magnetic field,"We have implemented three approaches to describe the thermodynamic properties
of ferrimagnetic ($S=5/2, s=2$) spin chains. The application of cumulant
expansion has been generalized to the ferrimagnetic chain in the presence of an
external magnetic field. Using cumulants, we have obtained the field dependent
effective Hamiltonian in terms of the classical variables up to the second
order of quantum corrections. Thermodynamic functions, the internal energy, the
specific heat and the magnetic susceptibility are obtained from the effective
Hamiltonian. We have also examined the modified spin wave theory to derive the
same physical properties. Finally, we have studied our model using quantum
Monte Carlo simulation to obtain accurate results. The comparison of the above
results and also the high temperature series expansion shows that cumulant
expansion gives good results for moderate and high temperature regions while
the modified spin wave theory is good for low temperatures. Moreover, the
convergence regions of the cumulant expansion and the modified spin wave theory
overlap each other which propose these two as a set of complement methods to
get the thermodynamic properties of spin models.",0601494v1
2006-03-10,Dielectric anomalies and spiral magnetic order in CoCr2O4,"We have investigated the structural, magnetic, thermodynamic, and dielectric
properties of polycrystalline CoCr$_2$O$_4$, an insulating spinel exhibiting
both ferrimagnetic and spiral magnetic structures. Below $T_c$ = 94 K the
sample develops long-range ferrimagnetic order, and we attribute a sharp phase
transition at $T_N$ $\approx$ 25 K with the onset of long-range spiral magnetic
order. Neutron measurements confirm that while the structure remains cubic at
80 K and at 11 K; there is complex magnetic ordering by 11 K. Density
functional theory supports the view of a ferrimagnetic semiconductor with
magnetic interactions consistent with non-collinear ordering. Capacitance
measurements on CoCr$_2$O$_4$, show a sharp decrease in the dielectric constant
at $T_N$, but also an anomaly showing thermal hysteresis falling between
approximately $T$ = 50 K and $T$ = 57 K. We tentatively attribute the
appearance of this higher temperature dielectric anomaly to the development of
\textit{short-range} spiral magnetic order, and discuss these results in the
context of utilizing dielectric spectroscopy to investigate non-collinear
short-range magnetic structures.",0603307v1
2007-02-19,Defects-driven appearance of half-metallic ferrimagnetism in Co-Mn--based Heusler alloys,"Half-metallic ferromagnetic full-Heusler alloys containing Co and Mn, having
the formula Co$_2$MnZ where Z a sp element, are among the most studied Heusler
alloys due to their stable ferromagnetism and the high Curie temperatures which
they present. Using state-of-the-art electronic structure calculations we show
that when Mn atoms migrate to sites occupied in the perfect alloys by Co, these
Mn atoms have spin moments antiparallel to the other transition metal atoms.
The ferrimagnetic compounds, which result from this procedure, keep the
half-metallic character of the parent compounds and the large
exchange-splitting of the Mn impurities atoms only marginally affects the width
of the gap in the minority-spin band. The case of [Co$_{1-x}$Mn$_x$]$_2$MnSi is
of particular interest since Mn$_3$Si is known to crystallize in the Heusler
$L2_1$ lattice structure of Co$_2$MnZ compounds. Robust half-metallic
ferrimagnets are highly desirable for realistic applications since they lead to
smaller energy losses due to the lower external magnetic fields created with
respect to their ferromagnetic counterparts.",0702437v1
2007-03-02,"Ab-initio design of half-metallic fully-compensated ferrimagnets: the case of Cr$_2$MnZ (Z= P, As, Sb, Bi) compounds","Electronic structure calculations from first-principles are employed to
design some new half-metallic fully-compensated ferrimagnets (or as they are
widely known half-metallic antiferromagnets) susceptible of finding
applications in spintronics. Cr$_2$MnZ (Z= P, As, Sb, Bi) compounds have 24
valence electrons per unit cell and calculations show that their total spin
moment is approximately zero for a wide range of lattice constants in agreement
with the Slater-Pauling behavior for ideal half-metals. Simultaneously, the
spin magnetic moments of Cr and Mn atoms are antiparallel and the compounds are
ferrimagnets. Mean-field approximation is employed to estimate their Curie
temperature, which exceeds room temperature for the alloy with Sb. Our findings
suggest that Cr$_2$MnSb is the compound of choice for further experimental
investigations. Contrary to the alloys mentioned above half-metallic
antiferromagnetism is unstable in the case of the Cr$_2$FeZ (Z= Si, Ge, Sn)
alloys.",0703078v1
2007-11-07,"Low-energy structure of the intertwining double-chain ferrimagnets A_3_Cu_3_(PO_4_)_4_ (A=Ca,Sr,Pb)","Motivated by the homometallic intertwining double-chain ferrimagnets
A_3_Cu_3_(PO_4_)_4_ (A=Ca,Sr,Pb), we investigate the low-energy structure of
their model Hamiltonian H=\sum_n_[J_1_(S_{n :1}_+S_{n :3}_)
+J_2_(S_{n+1:1}+S_{n-1:3}_)]\cdotS_{n:2}_, where S_{n:l}_ stands for the
Cu^{2+}^ ion spin labeled l in the nth trimer unit, with particular emphasis on
the range of bond alternation 0<J_2/J_1<1. Although the spin-wave theory,
whether up to O(S^1^) or up to O(S^0^), claims that there exists a flat band in
the excitation spectrum regardless of bond alternation, a perturbational
treatment as well as the exact diagonalization of the Hamiltonian reveals its
weak but nonvanishing momentum dispersion unless J_2_=J_1_ or J_2_=0. Quantum
Monte Carlo calculations of the static structure factor further convince us of
the low-lying excitation mechanism, elucidating similarities and differences
between the present system and alternating-spin linear-chain ferrimagnets.",0711.1051v1
2009-05-07,Towards the theory of ferrimagnetism II,"The present paper is a sequel to the paper by Karchev (2008
J.Phys.:Condens.Matter {\bf 20} 325219). A two-sublattice ferrimagnet, with
spin-$s_1$ operators $\bf{S_{1i}}$ at the sublattice $A$ site and spin-$s_2$
operators $\bf{S_{2i}}$ at the sublattice $B$ site, is considered. Renormalized
spin-wave theory, which accounts for the magnon-magnon interaction, and its
extension are developed to describe the two ferrimagnetic phases $(0,T^*)$ and
$(T^*,T_N)$ in the system, and to calculate the magnetization as a function of
temperature.
  The influence of the parameters in the theory on the characteristic
temperatures $T_N$ and $T^*$ is studied. It is shown that, increasing the
inter-sublattice exchange interaction, the ratio $T_N/T^*>1$ decreases
approaching one, and above some critical value of the exchange constant there
is only one phase $T_N = T^*$, and the magnetization-temperature curve has the
typical Curie-Weiss profile. When the intra-exchange constant of sublattice
with stronger intra-exchange interaction increases the $Ne\grave{e}l$
temperature increases while $T^*$ remains unchanged. Finally, when the magnetic
order of the sublattice with smaller magnetic order decreases, $T^*$ decreases.
The theoretical predictions are utilize to interpret the experimentally
measured magnetization-temperature curves.",0905.1036v1
2009-09-01,Magnetism in Re-based ferrimagnetic double perovskites,"We have investigated spin and orbital magnetic moments of the Re 5d ion in
the double perovskites A2FeReO6 (A = Ba, Sr, Ca) by X-ray magnetic circular
dichroism (XMCD) at the Re L(2,3) edges. In these ferrimagnetic compounds an
unusually large negative spin and positive orbital magnetic moment at the Re
atoms was detected. The presence of a finite spin magnetic moment in a
'non-magnetic' double perovskite as observed in the double perovskite Sr2ScReO6
proves that Re has also a small, but finite intrinsic magnetic moment. We
further show for the examples of Ba and Ca that the usually neglected alkaline
earth ions undoubtedly also contribute to the magnetism in the ferrimagnetic
double perovskites.",0909.0209v1
2010-11-10,"Ab initio prediction of ferrimagnetism, exchange interactions and Curie temperatures in Mn2TiZ Heusler compounds","The Heusler compounds Mn$_2$TiZ (Z = Al, Ga, In, Si, Ge, Sn, P, As, Sb) are
of large interest due to their potential ferrimagnetic properties and high spin
polarization. Here, we present calculations of the structural and magnetic
properties of these materials. Their magnetic moment follows the Slater-Pauling
rule $m = N_V - 24$. None of them is actually a perfect half-metallic
ferrimagnet, but some exhibit more than 90% spin polarization and Curie
temperatures well above room temperature. The exchange interactions are
complex, direct and indirect exchange contributions are identified. The Curie
temperature scales with the total magnetic moment, and it has a positive
pressure dependence. The role of the Z element is investigated: it influences
the properties of the compounds mainly via its valence electron number and its
atomic radius, which determines the lattice parameter. Based on these results,
Mn$_2$TiSi, Mn$_2$TiGe, and Mn$_2$TiSn are proposed as candidates for
spintronic applications.",1011.2486v1
2011-01-31,Ferrimagnetism and disorder in epitaxial Mn(2-x)Co(x)VAl thin films,"The quaternary full Heusler compound Mn(2-x)Co(x)VAl with x = 1 is predicted
to be a half-metallic antiferromagnet. Thin films of the quaternary compounds
with x = 0...2 were prepared by DC and RF magnetron co-sputtering on heated MgO
(001) substrates. The magnetic structure was examined by x-ray magnetic
circular dichroism and the chemical disorder was characterized by x-ray
diffraction. Ferrimagnetic coupling of V to Mn was observed for Mn2VAl (x = 0).
For x = 0.5, we also found ferrimagnetic order with V and Co antiparallel to
Mn. The observed reduced magnetic moments are interpreted with the help of band
structure calculations in the coherent potential approximation. Mn2VAl is very
sensitive to disorder involving Mn, because nearest-neighbor Mn atoms couple
anti-ferromagnetically. Co2VAl has B2 order and has reduced magnetization. In
the cases with x >= 0.9 conventional ferromagnetism was observed, closely
related to the atomic disorder in these compounds.",1101.5994v1
2011-03-15,Oxygen hyperstoichiometric hexagonal ferrite CaBaFe4O7+δ(δ \approx 0.14) : coexistence of ferrimagnetism and spin glass behavior,"An oxygen hyperstoichiometric ferrite CaBaFe4O7+\delta (\delta \approx 0.14)
has been synthesized using ""soft"" reduction of CaBaFe4O8. Like the oxygen
stoichiometric ferrimagnet CaBaFe4O7, this oxide also keeps the hexagonal
symmetry (space group: P63mc), and exhibits the same high Curie temperature of
270 K. However, the introduction of extra oxygen into the system weakens the
ferrimagnetic interaction significantly at the cost of increased magnetic
frustration at low temperature. Moreover, this canonical spin glass (Tg ~ 166
K) exhibits an intriguing cross-over from de Almeida-Thouless type to
Gabay-Toulouse type critical line in the field temperature plane above a
certain field strength, which can be identified as the anisotropy field. Domain
wall pinning is also observed below 110 K. These results are interpreted on the
basis of cationic disordering on the iron sites.",1103.2939v1
2011-09-13,Interplay between non equilibrium and equilibrium spin torque using synthetic ferrimagnets,"We discuss the current induced magnetization dynamics of spin valves F0|N|SyF
where the free layer is a synthetic ferrimagnet SyF made of two ferromagnetic
layers F1 and F2 coupled by RKKY exchange coupling. In the interesting
situation where the magnetic moment of the outer layer F2 dominates the
magnetization of the ferrimagnet, we find that the sign of the effective spin
torque exerted on the free middle layer F1 is controlled by the strength of the
RKKY coupling: for weak coupling one recovers the usual situation where spin
torque tends to, say, anti-align the magnetization of F1 with respect to the
pinned layer F0. However for large coupling the situation is reversed and the
spin torque tends to align F1 with respect to F0. Careful numerical simulations
in the intermediate coupling regime reveal that the competition between these
two incompatible limits leads generically to spin torque oscillator (STO)
behavior. The STO is found in the absence of magnetic field, with very
significant amplitude of oscillations and frequencies up to 50 GHz or higher.",1109.2705v2
2012-02-28,"Gallium Substituted ""114"" YBaFe4O7: From a ferrimagnetic cluster glass to a cationic disordered spin glass","The study of the ferrites YBaFe4-xGaxO7 shows that the substitution of Ga for
Fe in YBaFe4O7 stabilizes the hexagonal symmetry for 0.40 < x < 0.70, at the
expense of the cubic one. Using combined measurements of a. c. and d. c.
magnetization, we establish that Ga substitution for Fe in YBaFe4O7 leads to an
evolution from a geometrically frustrated spin glass (for x = 0) to a cationic
disorder induced spin glass (x = 0.70). We also find an intermediate narrow
range of doping where the samples are clearly phase separated having small
ferrimagnetic clusters embedded in a spin glass matrix. The origin of the
ferrimagnetic clusters lies in the change in symmetry of the samples from cubic
to hexagonal (and a consequent lifting of the geometrical frustration) as a
result of Ga doping. We also show the presence of exchange bias and domain wall
pinning in these samples. The cause of both these effects can be traced back to
the inherent phase separation present in the samples.",1202.6166v1
2012-06-28,The Landau-Lifshitz-Bloch equation for ferrimagnetic materials,"We derive the Landau-Lifshitz-Bloch (LLB) equation for a two-component
magnetic system valid up to the Curie temperature. As an example, we consider
disordered GdFeCo ferrimagnet where the ultrafast optically induced
magnetization switching under the action of heat alone has been recently
reported. The two-component LLB equation contains the longitudinal relaxation
terms responding to the exchange fields from the proper and the neighboring
sublattices. We show that the sign of the longitudinal relaxation rate at high
temperatures can change depending on the dynamical magnetization value and a
dynamical polarisation of one material by another can occur. We discuss the
differences between the LLB and the Baryakhtar equation, recently used to
explain the ultrafast switching in ferrimagnets. The two-component LLB equation
forms basis for the largescale micromagnetic modeling of nanostructures at high
temperatures and ultrashort timescales.",1206.6672v1
2012-09-18,Nontrivial ferrimagnetism of the Heisenberg model on the Union Jack strip lattice,"We study the ground-state properties of the S=1/2 antiferromagnetic
Heisenberg model on the Union Jack strip lattice by using the
exact-diagonalization and density matrix renormalization group methods. We
confirm a region of the intermediate-magnetization state between the Neel-like
spin liquid state and the conventional ferrimagnetic state of Lieb-Mattis type.
In the intermediate-state, we find that the spontaneous magnetization changes
gradually with respect to the strength of the inner interaction. In addition,
the local magnetization clearly shows an incommensurate modulation with
long-distance periodicity in the intermediate-magnetization state. These
characteristic behaviors lead to the conclusion that the
intermediate-magnetization state is the non-Lieb-Mattis ferrimagnetic one. We
also discuss the relationship between the ground-state properties of the S=1/2
antiferromagnetic Heisenberg model on the original Union Jack lattice and those
on our strip lattice.",1209.3965v1
2013-02-22,Gigantic magnetic field polarization and magnetoelectric coupling in a ferrimagnetic oxide CaBaCo4O7,"The single crystal study of CaBaCo4O7, a non collinear ferrimagnet (TC=64K),
with a polar orthorhombic space group (Pbn21) between 4 K and 293 K, shows the
appearance below TC of a large electric polarization along its c axis, reaching
17mC.m-2 at 10K. At 62.5K, a magnetic field driven giant variation of
polarization, P(9T)-P(0T)=8mC.m-2, is observed. Moreover, the present
magnetoelectric measurements, are fully consistent with the m'm2' magnetic
point group, strongly supporting that this oxide is also ferrotoroidic. This
ferrimagnetic oxide, which belongs to the '114' structural family, opens an
avenue for the search of new magnetoelectrics.",1302.5541v2
2013-03-06,Change in the Magnetic Domain Alignment Process at the Onset of a Frustrated Magnetic State in Ferrimagnetic La2Ni(Ni1/3Sb2/3)O6 Double Perovskite,"We have performed a combined study of magnetization hysteresis loops and time
dependence of the magnetization in a broad temperature range for the
ferrimagnetic La2Ni(Ni1/3Sb2/3)O6 double perovskite. This material has a
ferrimagnetic order transition at ~100 K and at lower temperatures (~ 20 K)
shows the signature of a frustrated state due to the presence of two competing
magnetic exchange interactions. The temperature dependence of the coercive
field shows an important upturn below the point where the frustrated state sets
in. The use of the magnetization vs. applied magnetic field hysteresis data,
together with the magnetization vs. time data provides a unique opportunity to
distinguish between different scenarios for the low temperature regime. From
our analysis, a strong domain wall pinning results the best scenario for the
low temperature regime. For temperatures larger than 20K the adequate scenario
seems to correspond to a weak domain wall pinning.",1303.1372v1
2013-05-14,Electromagnon in ferrimagnetic eps-Fe2O3 nanograin ceramics,"Electromagnons are known from multiferroics as spin waves excited by the
electric component of electromagnetic radiation. We report the discovery of an
excitation in the far-infrared spectra of eps-Fe2O3 which we attribute to an
electromagnon appearing below 110 K, where the ferrimagnetic structure becomes
incommensurately modulated. Inelastic neutron scattering shows that the
electromagnon energy corresponds to that of a magnon from the Brillouin zone
boundary. Dielectric measurements did not reveal any sign of ferroelectricity
in eps-Fe2O3 down to 10 K, despite its acentric crystal structure. This shows
that the activation of an electromagnon requires, in addition to the polar
ferrimagnetic structure, a modulation of the magnetic structure. We demonstrate
that a combination of inelastic neutron scattering with infrared and / or
terahertz spectroscopies allows detecting electromagnons in ceramics, where no
crystal-orientation analysis of THz and infrared spectra is possible.",1305.3064v3
2013-10-07,Ferrimagnetic Slater Insulator Phase of the Sn/Ge(111) Surface,"We have performed the semilocal and hybrid density-functional theory (DFT)
studies of the Sn/Ge(111) surface to identify the origin of the observed
insulating ${\sqrt{3}}{\times}{\sqrt{3}}$ phase below ${\sim}$30 K. Contrasting
with the semilocal DFT calculation predicting a metallic 3${\times}$3 ground
state, the hybrid DFT calculation including van der Waals interactions shows
that the insulating ferrimagnetic structure with ${\sqrt{3}}{\times}{\sqrt{3}}$
structural symmetry is energetically favored over the metallic 3${\times}$3
structure. It is revealed that the correction of self-interaction error with a
hybrid exchange-correlation functional gives rise to a band-gap opening induced
by a ferrimagnetic order. The results manifest that the observed insulating
phase is attributed to the Slater mechanism via itinerant magnetic order rather
than the hitherto accepted Mott-Hubbard mechanism via electron correlations.",1310.1782v1
2013-12-20,Effects of the spin-orbital coupling on the vacancy-induced magnetism on the honeycomb lattice,"The local magnetism induced by vacancies in the presence of the spin-orbital
interaction is investigated based on the half-filled Kane-Mele-Hubbard model on
the honeycomb lattice. Using the self-consistent mean-field theory, we find
that the spin-orbital coupling will enhance the localization of the spin
moments near a single vacancy. We further study the magnetic structures along
the zigzag edges formed by a chain of vacancies. We find that the spin-orbital
coupling tends to suppress the counter-polarized ferrimagnetic order on the
upper and lower edges, because of the open of the spin-orbital gap. As a
result, in the case of the balance number of sublattices, it will suppress
completely this kind of ferrimagnetic order. But, for the imbalance case, a
ferrimagnetic order along both edges exists because additional zero modes will
not be affected by the spin-orbital coupling.",1312.5809v1
2015-04-17,Model for the FC and ZFC Ferrimagnetic Spinel,"There are two methods of preparation of ferrimagnetic spinel. If, during the
preparation, an external magnetic field as high as 300 O\""{e} is applied upon
cooling the material is named field-cooled (FC). If the applied field is about
1O\""{e} the material is zero-field cooled (ZFC). To explore the magnetic and
thermodynamic properties of these materials we consider two-sublattice spin
system, defined on the bcc lattice, with spin-$s^A$ operators $\bf{S_{i}^A}$ at
the sublattice $A$ site and spin-$s^B$ operators $\bf{S_{i}^B}$ at the
sublattice $B$ site, where $s^A>s^B$. The subtle point is the exchange between
sublattice A and B spins, which is antiferromanetic. Applying magnetic field
along the sublattice A magnetization, during preparation of the material, one
compensates the Zeeman splitting, due to the exchange, of sublattice B
electrons. This effectively leads to a decrease of the $s^B$ spin. We consider
a model with $s^B$ varying parameter which accounts for the applied, during the
preparation, magnetic field.
  It is shown that the model agrees well with the observed
magnetization-temperature curves of zero field cooled (ZFC) and non-zero field
cooled (FC) spinel ferrimagnetic spinel and explains the anomalous temperature
dependence of the specific heat.",1504.04547v1
2015-11-06,Coupled Cluster Treatment of the Alternating Bond Diamond Chain,"By the analytical coupled cluster method (CCM), we study both the ground
state and lowest-lying excited-state properties of the alternating bond diamond
chain. The numerical exact diagonalization (ED) method is also applied to the
chain to verify the accuracy of CCM results. The ED results show that the
ground-state phase diagram contains two exact spin cluster solid ground states,
namely, the tetramer-dimer (TD) state and dimer state, and the ferrimagnetic
long-range-ordered state. We prove that the two exact spin cluster solid ground
states can both be formed by CCM. Moreover, the exact spin gap in the TD state
can be obtained by CCM. In the ferrimagnetic region, we find that the CCM
results for some physical quantities, such as the ground-state energy, the
sublattice magnetizations, and the antiferromagnetic gap, are comparable to the
results obtained by numerical methods. The critical line dividing the TD state
from the ferrimagnetic state is also given by CCM and is in perfect agreement
with that determined by the ED method.",1511.01985v1
2016-07-14,Room temperature polarization in the ferrimagnetic Ga2-xFexO3 ceramics,"The effect of the Fe-Ga ratio on the magnetic and electric properties of the
multiferroic Ga2-xFexO3 compound has been studied in order to determine the
composition range exhibiting magnetic and electric orders coexistence and their
critical temperatures. A magnetoelectric phase diagram, showing the evolution
of both the Neel magnetic ordering temperature and the electric ordering
temperature, versus the iron content has been established for x values between
0.9 and 1.4. While the ferrimagnetic Neel temperature increases with the iron
content, the electric ordering temperature shows an opposite trend. The
electric polarization has been found to exist far above room temperature for
the x value of 1.1 composition which shows the highest observed electric
ordering temperature of approx. 580K. The compounds with x values of 1.3 and
1.4 are ferrimagnetic-electric relaxors with both properties coexisting at room
temperature.",1607.04312v1
2016-07-21,Ferrimagnetism in delta chain with anisotropic ferromagnetic and antiferromagnetic interactions,"We consider analytically and numerically an anisotropic spin-$\frac{1}{2}$
delta-chain (sawtooth chain) in which exchange interactions between apical and
basal spins are ferromagnetic and those between basal spins are
antiferromagnetic. In the limit of strong anisotropy of exchange interactions
this model can be considered as the Ising delta chain with macroscopic
degenerate ground state perturbed by transverse quantum fluctuations. These
perturbations lift the ground state degeneracy and the model reduces to the
basal XXZ spin chain in the magnetic field induced by static apical spins. We
show that the ground state of such model is ferrimagnetic. The excitations of
the model are formed by ferrimagnetic domains separated by domain walls with a
finite energy. At low temperatures the system is effectively divided into two
independent subsystems, the apical subsystem described by the Ising
spin-$\frac{1}{2}$ chain and the basal subsystem described by the XXZ chain
with infinite $zz$ interactions.",1607.06200v1
2016-09-19,Switching ferromagnetic spins by an ultrafast laser pulse: Emergence of giant optical spin-orbit torque,"Faster magnetic recording technology is indispensable to massive data storage
and big data sciences. {All-optical spin switching offers a possible solution},
but at present it is limited to a handful of expensive and complex rare-earth
ferrimagnets. The spin switching in more abundant ferromagnets may
significantly expand the scope of all-optical spin switching. Here by studying
40,000 ferromagnetic spins, we show that it is the optical spin-orbit torque
that determines the course of spin switching in both ferromagnets and
ferrimagnets. Spin switching occurs only if the effective spin angular momentum
of each constituent in an alloy exceeds a critical value. Because of the strong
exchange coupling, the spin switches much faster in ferromagnets than
weakly-coupled ferrimagnets. This establishes a paradigm for all-optical spin
switching. The resultant magnetic field (65 T) is so big that it will
significantly reduce high current in spintronics, thus representing the
beginning of photospintronics.",1609.05855v1
2016-10-28,Spin-Orbit Torque Efficiency in Compensated Ferrimagnetic Cobalt-Terbium Alloys,"Despite the potential advantages of information storage in
antiferromagnetically coupled materials, it remains unclear whether one can
control the magnetic moment orientation efficiently because of the cancelled
magnetic moment. Here, we report spin-orbit torque induced magnetization
switching of ferrimagnetic Co1-xTbx films with perpendicular magnetic
anisotropy. Current induced switching is demonstrated in all of the studied
film compositions, including those near the magnetization compensation point.
The spin-orbit torque induced effective field is further quantified in the
domain wall motion regime. A divergent behavior that scales with the inverse of
magnetic moment is confirmed close to the compensation point, which is
consistent with angular momentum conservation. Moreover, we also quantify the
Dzyaloshinskii-Moriya interaction energy in the Ta/Co1-xTbx system and we find
that the energy density increases as a function of the Tb concentration. The
demonstrated spin-orbit torque switching, in combination with the fast magnetic
dynamics and minimal net magnetization of ferrimagnetic alloys, promises
spintronic devices that are faster and with higher density than traditional
ferromagnetic systems.",1610.09200v1
2019-05-09,Bidirectional spin-wave-driven domain wall motion in antiferromagnetically coupled ferrimagnets,"We investigate ferrimagnetic domain wall dynamics induced by circularly
polarized spin waves theoretically and numerically. We find that the direction
of domain wall motion depends on both the circular polarization of spin waves
and the sign of net spin density of ferrimagnet. Below the angular momentum
compensation point, left- (right-) circularly polarized spin waves push a
domain wall towards (away from) the spin-wave source. Above the angular
momentum compensation point, on the other hand, the direction of domain wall
motion is reversed. This bidirectional motion originates from the fact that the
sign of spin-wave-induced magnonic torque depends on the circular polarization
and the subsequent response of the domain wall to the magnonic torque is
governed by the net spin density. Our finding provides a way to utilize a spin
wave as a versatile driving force for bidirectional domain wall motion.",1905.03521v1
2020-07-14,Three-dimensional Ising Ferrimagnetism of Cr-Fe-Cr trimers in FeCr2Te4,"We carried out a comprehensive study of magnetic critical behavior in single
crystals of ternary chalcogenide FeCr$_2$Te$_4$ that undergoes a ferrimagnetic
transition below $T_c$ $\sim$ 123 K. Detailed critical behavior analysis and
scaled magnetic entropy change indicate a second-order ferrimagentic
transition. Critical exponents $\beta = 0.30(1)$ with $T_c = 122.4(5)$ K,
$\gamma = 1.22(1)$ with $T_c = 122.8(1)$ K, and $\delta = 4.24(2)$ at $T_c$
$\sim$ 123 K suggest that the spins approach three-dimensional Ising ($\beta$ =
0.325, $\gamma$ = 1.24, and $\delta$ = 4.82) model coupled with the attractive
long-range interactions between spins that decay as $J(r)\approx r^{-4.88}$.
Our results suggest that the ferrimagnetism in FeCr$_2$Te$_4$ is due to
itinerant ferromagnetism among the antiferromagnetically coupled Cr-Fe-Cr
trimers.",2007.06805v2
2010-05-28,Haldane Phases and Ferrimagnetic Phases with Spontaneous Translational Symmetry Breakdown in Distorted Mixed Diamond Chains with Spins 1 and 1/2,"The ground states of two types of distorted mixed diamond chains with spins 1
and 1/2 are investigated using exact diagonalization, DMRG, and mapping onto
low-energy effective models. In the undistorted case, the ground state consists
of an array of independent spin-1 clusters separated by singlet dimers. The
lattice distortion induces an effective interaction between cluster spins. When
this effective interaction is antiferromagnetic, several Haldane phases appear
with or without spontaneous translational symmetry breakdown (STSB). The
transition between the Haldane phase without STSB and that with $(n+1)$-fold
STSB ($n$ = 1, 2, and 3) belongs to the same universality class as the
$(n+1)$-clock model. In contrast, when the effective interaction is
ferromagnetic, the quantized and partial ferrimagnetic phases appear with or
without STSB. An effective low-energy theory for the partial ferrimagnetic
phase is presented.",1005.5297v2
2018-05-08,Spin-Hall and Anisotropic Magnetoresistance in Ferrimagnetic Co-Gd / Pt layers,"We present the Co-Gd composition dependence of the spin-Hall
magnetoresistance (SMR) and anisotropic magnetoresistance (AMR) for
ferrimagnetic Co100-xGdx / Pt bilayers. With Gd concentration x, its magnetic
moment increasingly competes with the Co moment in the net magnetization. We
find a nearly compensated ferrimagnetic state at x = 24. The AMR changes sign
from positive to negative with increasing x, vanishing near the magnetization
compensation. On the other hand, the SMR does not vary significantly even where
the AMR vanishes. These experimental results indicate that very different
scattering mechanisms are responsible for AMR and SMR. We discuss a possible
origin for the alloy composition dependence.",1805.02827v2
2018-05-27,Prediction of new multiferroic and magnetoelectric material Fe3Se4,"Nowdays, multiferroic materials with magnetoelectric coupling have many
real-world applications in the fields of novel memory devices. It is
challenging is to create multiferroic materials with strongly coupled
ferroelectric and ferrimagnetic orderings at room temperature. The single
crystal of ferric selenide (Fe3Se4) shows type-II multiferroic due to the
coexistence of ferroelectric as well as magnetic ordering at room temperature.
We have investigated the lattice instability, electronic structure,
ferroelectric, ferrimagnetic ordering and transport properties of ferroelectric
metal Fe3Se4. The density of states shows considerable hybridization of Fe-3d
and Se-4p states near the Fermi level confirming its metallic behavior. The
magnetic moments of Fe cations follow a type-II ferrimagnetic and ferroelectric
ordering with a calculated total magnetic moment of 4.25 per unit cell
(Fe6Se8). The strong covalent bonding nature of Fe-Se leads to its
ferroelectric properties. In addition, the symmetry analysis suggests that
tilting of Fe sub-lattice with 3d-t2g orbital ordering is due to the
Jahn-Teller (JT) distortion. This study provides further insight in the
development of spintronics related technology using multiferroic materials.",1805.10607v1
2008-07-25,Frustration-induced quantum phase transitions in a quasi-one-dimensional ferrimagnet: Hard-core boson map and the Ton ks-Girardeau limit,"We provide evidence of a superfluid-insulator transition (SIT) of magnons in
a quasi-one-dimensional quantum ferrimagnet with {\it isotropic} competing
antiferromagnetic spin interactions. This SIT occurs between two distinct
ferrimagnetic phases due to the frustration-induced closing of the gap to a
magnon excitation. It thus causes a coherent superposition of singlet and
triplet states at lattice unit cells and a power-law decay on the staggered
spin correlation function along the transverse direction to the spontaneous
magnetization. A hard-core boson map suggests that asymptotically close to the
SIT the magnons attain the Tonks-Girardeau limit. The quantized nature of the
condensed singlets is observed before a first-order transition to a singlet
magnetic spiral phase accompanied by critical antiferromagnetic ordering. In
the limit of strong frustration, the system undergoes a decoupling transition
to an isolated gapped two-leg ladder and a critical single linear chain.",0807.4153v1
2017-06-20,"Magnetic signatures of quantum critical points of the ferrimagnetic mixed spin-(1/2, S) Heisenberg chains at finite temperatures","Magnetic properties of the ferrimagnetic mixed spin-(1/2,S) Heisenberg chains
are examined using quantum Monte Carlo simulations for two different quantum
spin numbers S = 1 and 3/2. The calculated magnetization curves at finite
temperatures are confronted with zero-temperature magnetization data obtained
within density-matrix renormalization group method, which imply an existence of
two quantum critical points determining a breakdown of the gapped Lieb-Mattis
ferrimagnetic phase and Tomonaga-Luttinger spin-liquid phase, respectively.
While a square-root behavior of the magnetization accompanying each quantum
critical point is gradually smoothed upon rising temperature, the
susceptibility and isothermal entropy change data provide a stronger evidence
of the quantum critical points at finite temperatures through marked local
maxima and minima, respectively.",1706.06379v1
2017-06-21,Spin pumping and shot noise in ferrimagnets: bridging ferro- and antiferromagnets,"A combination of novel technological and fundamental physics prospects has
sparked a huge interest in pure spin transport in magnets, starting with
ferromagnets and spreading to antiferro- and ferrimagnets. We present a
theoretical study of spin transport across a ferrimagnet$|$non-magnetic
conductor interface, when a magnetic eigenmode is driven into a coherent state.
The obtained spin current expression includes intra- as well as
cross-sublattice terms, both of which are essential for a quantitative
understanding of spin-pumping. The dc current is found to be sensitive to the
asymmetry in interfacial coupling between the two sublattice magnetizations and
the mobile electrons, especially for antiferromagnets. We further find that the
concomitant shot noise provides a useful tool for probing the quasiparticle
spin and interfacial coupling.",1706.07118v2
2017-07-06,Switching from pyroelectric to ferroelectric order in Ni doped CaBaCo4O7,"We report ferroelectric ordering in Ni substituted CaBaCo4O7. Magnetization
showed ferrimagnetic transition at 60 K and an additional transition is found ~
82 K, further, enhanced antiferromagnetic interactions and decrease in
saturation magnetization are noticed with Ni substitution. The dielectric and
pyroelectric measurements illustrate a strong coupling between spin and charge
degrees of freedom; ferroelectric behavior is confirmed with enhanced ordering
temperature (~82 K) and saturation polarization (250 muC/m2. Neutron
diffraction has revealed an increase in c-lattice parameter in Ni sample and
all the Co/Ni moments are reoriented in a- direction; evidently a non-collinear
ferrimagnetic to collinear ferrimagnetic spin order is observed. The coupling
between the triangular and Kagome layers weakens and leads to up-up-down-down
AFM ordering in the Kagoma layer. This can be viewed as a 2D-collinear layer
with unequal bond distances and most likely responsible for the switching of
electric polarization.",1707.01712v1
2019-06-21,Magnetic domains without domain walls: a unique effect of He+ ion bombardment in ferrimagnetic Co/Tb multilayers,"We show that it is possible to engineer magnetic multi-domain configurations
without domain walls in a prototypical rare earth/transition metal ferrimagnet
using keV He+ ion bombardment. We additionally shown that these patterns
display a particularly stable magnetic configuration due to a deep minimum in
the free energy of the system which is caused by flux closure and the
corresponding reduction of the magnetostatic part of the total free energy.
This is possible because light-ion bombardment differently affects an elements
relative contribution to the effective properties of the ferrimagnet. The
impact of bombardment is stronger for rare earth elements. Therefore, it is
possible to influence the relative contributions of the two magnetic subsystems
in a controlled manner. The selection of material system and the use of
light-ion bombardment open a route to engineer domain patterns in continuous
magnetic films much smaller than what is currently considered possible.",1906.09318v1
2019-09-12,Single pulse all-optical toggle switching of magnetization without Gd: The example of Mn2RuxGa,"Energy-efficient control of magnetization without the help of a magnetic
field is a key goal of spintronics. Purely heat-induced single-pulse
all-optical toggle switching has been demonstrated, but so far only in Gd based
amorphous ferrimagnet films. In this work, we demonstrate toggle switching in
the half-metallic compensated ferrimagnetic Heusler alloys Mn2RuxGa, which have
two crystallographically-inequivalent Mn sublattices. Moreover, we observe the
switching at room temperature in samples that are immune to external magnetic
fields in excess of 1 T, provided they exhibit compensation above room
temperature. Observations of the effect in compensated ferrimagnets without Gd
challenges our understanding of all-optical switching. The dynamic behavior
indicates that Mn2RuxGa switches in 2 ps or less. Our findings widen the basis
for fast optical switching of magnetization and break new ground for engineered
materials that can be used for nonvolatile ultrafast switches using ultrashort
pulses of light.",1909.05809v2
2020-01-03,Neutron diffraction and ab initio studies on the fully compensated ferrimagnetic characteristics of Mn2V1-xCoxGa Heusler alloys,"Neutron diffraction and ab initio studies were carried out on Mn2V1-xCoxGa
(x=0, 0.25, 0.5, 0.75, 1) Heusler alloys which exhibits high TC fully
compensated ferrimagnetic characteristic for x=0.5. A combined analysis of
neutron diffraction and ab initio calculations revealed the crystal structure
and magnetic configuration which could not be determined from the X-ray
diffraction and magnetic measurements. As reported earlier, Rietveld refinement
of neutron diffraction data confirmed L21 structure for Mn2VGa and Xa structure
for Mn2CoGa. The alloys with x=0.25 and 0.5 possess L21 structure with Mn(C)-Co
disorder. As the Co concentration reaches 0.75, a structural transition has
been observed from disordered L21 to disordered Xa. Detailed ab initio studies
also confirmed this structural transition. The reason for the magnetic moment
compensation in Mn2(V1-xCox)Ga was identified to be different from that of the
earlier reported fully compensated ferrimagnet (MnCo)VGa. With the help of
neutron diffraction and ab initio studies, it is identified that the disordered
L21 structure with antiparallel coupling between the ferromagnetically aligned
magnetic moments of (Mn(A)-Mn(C)) and (V-Co) atom pairs enables the
compensation in Mn2V1-xCoxGa.",2001.00707v1
2020-01-23,Magnetization plateaus and bipartite entanglement of an exactly solved spin-1/2 Ising-Heisenberg orthogonal-dimer chain,"Spin-1/2 orthogonal-dimer chain composed of regularly alternating Ising and
Heisenberg dimers is exactly solved in a presence of the magnetic field by the
transfer-matrix method. It is shown that the ground-state phase diagram
involves in total six different phases. Besides the ferromagnetic phase with
fully polarized spins one encounters the singlet antiferromagnetic and
modulated antiferromagnetic phases manifested in zero-temperature magnetization
curves as zero magnetization plateau, the frustrated ferrimagnetic and singlet
ferrimagnetic phases causing existence of an intermediate one-half
magnetization plateau, and finally, the intriguing modulated ferrimagnetic
phase with a translationally broken symmetry leading to an unconventional
one-quarter magnetization plateau. The quantum character of individual ground
states is quantified via the concurrence, which measures a strength of the
bipartite entanglement within the pure and mixed states of the Heisenberg
dimers at zero as well as nonzero temperatures. The parameter region, where the
bipartite entanglement may be in contrast to general expectations reinforced
upon increasing of temperature and/or magnetic field, is elucidated.",2001.08701v2
2020-12-01,Magnon hybridization in ferrimagnetic heterostructures,"We study magnon hybridization in a ferrimagnetic heterostructure consisting
of ultrathin gadolinium iron garnet and yttrium iron garnet layers and show the
localized and extended spatial profiles of the magnon modes with different
polarizations. These modes are expected to have distinct thermal excitation
properties in the presence of a temperature gradient across the
heterostructure. From a quantitative analysis of their consequences on
longitudinal spin Seebeck effect, we predict an observable shift of the
sign-changing temperature with respect to the one previously observed in
gadolinium iron garnet. Moreover, the sign-changing point of spin Seebeck
signal is found to be tunable by YIG thickness. Our results suggest the
necessity of taking into account the temperature difference between the magnon
modes in ferrimagnetic heterostructures.",2012.00576v1
2020-12-12,Ultra-fast Double Pulse All-Optical Re-switching of a Ferrimagnet,"All-optical re-switching has been investigated in the half-metallic Heusler
ferrimagnet Mn2Ru0.9Ga, where Mn atoms occupy two inequivalent sites in the
XA-type structure. The effect of a second 200 fs 800 nm pump pulse that follows
a first pulse, when both are above the threshold for switching, is studied as a
function of t12, the time between them. The aims are to identify the physical
mechanisms involved and to determine the minimum time needed for re-switching.
The time trajectory of the switching process on a plot of sublattice angular
momentum, S4a vs S4c, is in three stages; When t < 0.1 ps, the sublattice
moments are rapidly disordered, but not destroyed, while conserving net angular
momentum via optical spin-wave excitations. This leads to transient parallel
alignment of the residual Mn spins in the first quadrant. The net angular
momentum associated with the majority sublattice then flips in about 2 ps, and
a fully-reversed ferrimagnetic state is then established via the spin-lattice
interaction, which allows re-switching provided t12 > 10 ps.",2012.06823v1
2021-01-10,Tuning Dzyaloshinskii-Moriya Interaction in Ferrimagnetic GdCo: A First Principles Approach,"We present a systematic analysis of our ability to tune chiral
Dzyaloshinskii-Moriya Interactions (DMI) in compensated ferrimagnetic
Pt/GdCo/Pt1-xWx trilayers by cap layer composition. Using first principles
calculations, we show that the DMI increases rapidly for only ~ 10% W and
saturates thereafter, in agreement with experiments. The calculated DMI shows a
spread in values around the experimental mean, depending on the atomic
configuration of the cap layer interface. The saturation is attributed to the
vanishing of spin orbit coupling energy at the cap layer and the simultaneous
constancy at the bottom interface. Additionally, we predict the DMI in
Pt/GdCo/X (X=Ta, W, Ir) and find that W in the cap layer favors a higher DMI
than Ta and Ir that can be attributed to the difference in d-band alignment
around the Fermi level. Our results open up exciting combinatorial
possibilities for controlling the DMI in ferrimagnets towards nucleating and
manipulating ultrasmall high-speed skyrmions.",2101.03449v1
2017-05-08,Non-local magnon transport in the compensated ferrimagnet GdIG,"We study the diffusive transport of magnons through the compensated
ferrimagnetic insulator Gd3Fe5O12 (GdIG). The magnons are injected and detected
electrically in a non-local measurement configuration via two parallel Pt
strips deposited on top of the ferrimagnet. GdIG exhibits a rich magnon
spectrum, with several thermally populated magnon bands at room temperature. We
observe a strong temperature and field dependence of the non-local voltage in
the detector strip. Just below the magnetization compensation temperature we
find that the increasing magnetic field causes an unexpected enhancement of the
non-local signal. A comparison with GdIG spin wave spectra obtained from
atomistic modeling indicates that the thermal magnon population is important
for understanding the non-local voltage signal.",1705.02871v1
2017-11-15,Octahedral tilt independent magnetism in confined GdTiO$_3$ films,"Polarized neutron reflectometry measurements are presented exploring the
evolution of ferrimagnetism in GdTiO$_3$ films as they are confined between
SrTiO$_3$ layers of variable thicknesses. As GdTiO$_3$ films approach the thin
layer limit and are confined within a substantially thicker SrTiO$_3$ matrix,
the TiO$_6$ octahedral tilts endemic to GdTiO$_3$ coherently relax toward the
undistorted, cubic phase of SrTiO$_3$. Our measurements reveal that the
ferrimagnetic state within the GdTiO$_3$ layers survives as the TiO$_6$
octahedral tilts in the GdTiO$_3$ layers are suppressed. Furthermore, our data
suggest that a magnetic dead layer develops within the GdTiO$_3$ layer at each
GdTiO$_3$/ SrTiO$_3$ interface. The ferrimagnetic moment inherent to the core
GdTiO$_3$ layers is negligibly (in models with dead layers) or only weakly (in
models without dead layers) impacted as the octahedral tilt angles are
suppressed by more than 50$\%$ and the $t_{2g}$ bandwidth is dramatically
renormalized.",1711.05808v1
2018-03-01,Calculating the Magnetic Anisotropy of Rare-Earth-Transition-Metal Ferrimagnets,"Magnetocrystalline anisotropy, the microscopic origin of permanent magnetism,
is often explained in terms of ferromagnets. However, the best performing
permanent magnets based on rare earths and transition metals (RE-TM) are in
fact ferrimagnets, consisting of a number of magnetic sublattices. Here we show
how a naive calculation of the magnetocrystalline anisotropy of the classic
RE-TM ferrimagnet GdCo$_5$ gives numbers which are too large at 0 K and exhibit
the wrong temperature dependence. We solve this problem by introducing a
first-principles approach to calculate temperature-dependent magnetization vs.
field (FPMVB) curves, mirroring the experiments actually used to determine the
anisotropy. We pair our calculations with measurements on a recently-grown
single crystal of GdCo$_5$, and find excellent agreement. The FPMVB approach
demonstrates a new level of sophistication in the use of first-principles
calculations to understand RE-TM magnets.",1803.00235v1
2018-06-13,Low magnetic damping of ferrimagnetic GdFeCo alloys,"We investigate the Gilbert damping parameter for rare earth (RE)-transition
metal (TM) ferrimagnets over a wide temperature range. Extracted from the
field-driven magnetic domain-wall mobility, the Gilbert damping parameter was
as low as 0.0072 and was almost constant across the angular momentum
compensation temperature, starkly contrasting previous predictions that the
Gilbert damping parameter should diverge at the angular momentum compensation
temperature due to vanishing total angular momentum. Thus, magnetic damping of
RE-TM ferrimagnets is not related to the total angular momentum but is
dominated by electron scattering at the Fermi level where the TM has a dominant
damping role.",1806.04881v1
2018-06-17,Skyrmion Formation Induced by Antiferromagnetic-enhanced Interfacial Dzyaloshinskii Moriya Interaction,"Ne\'el skyrmions originate from interfacial Dzyaloshinskii Moriya interaction
(DMI). Recent studies have explored using ferromagnet to host Ne\'el skyrmions
for device applications. However, challenges remain to reduce the size of
skyrmion to near 10 nm. Amorphous rare-earth-transitional-metal ferrimagnets
are attractive alternative materials to obtain ultrasmall skyrmions at room
temperature. Their intrinsic perpendicular magnetic anisotropy and tunable
magnetization provides a favorable environment for skyrmion stability. In this
work, we employ atomistic stochastic Landau-Liftshitz-Gilbert (LLG) algorithm
to investigate skyrmions in GdFe within the interfacial DMI model. Despite the
rapid decay of DMI away from the interface, small skyrmions of near 10 nm are
found in thick ~ 5 nm amorphous GdFe film at 300K. We have also considered
three scenarios for the sign of DMI between Gd-Fe pair. It is revealed that
antiferromagnetic coupling in the ferrimagnet plays an important role in
enhancing the effect of interfacial DMI and to stabilize skyrmion. These
results show that ferrimagnets and antiferromagnets with intrinsic
antiferromagnetic couplings are appealing materials to host small skyrmions at
room temperature, which is crucial to improve density and energy efficiency in
skyrmion based devices.",1806.06334v1
2018-06-20,Magneto-optic Kerr effect in a spin-polarized zero-moment ferrimagnet,"The magneto-optical Kerr effect (MOKE) is often assumed to be proportional to
the magnetisation of a magnetically ordered metallic sample; in metallic
ferrimagnets with chemically distinct sublattices, such as rare-earth
transition-metal alloys, it depends on the difference between the sublattice
contributions. Here we show that in a highly spin polarized, fully compensated
ferrimagnet, where the sublattices are chemically similar, MOKE is observed
even when the net moment is strictly zero. We analyse the spectral ellipsometry
and MOKE of Mn 2 Ru x Ga, and show that this behaviour is due to a highly
spin-polarized conduction band dominated by one of the two manganese
sublattices which creates helicity-dependent reflectivity determined by a broad
Drude tail. Our findings open new prospects for studying spin dynamics in the
infra-red.",1806.07719v2
2018-07-18,Controlled anisotropic dynamics of tightly bound skyrmions in a synthetic ferrimagnet due to skyrmion-deformation mediated by induced uniaxial in-plane anisotropy,"We study speed and skew deflection-angle dependence on skyrmion deformations
of a tightly bound two-skyrmion state in a synthetic ferrimagnet. We condsider
here, an in-plane uniaxial magnetocrystalline anisotropy-term in order to
induce lateral shape distortions and an overall size modulation of the
skyrmions due to a reduction of the effective out-of-plane anisotropy, thus
affecting the skyrmion speed, skew-deflection and inducing anisotropy in these
quantities with respect to the driving current-angle. Because of frustrated
dipolar interactions in a synthetic ferrimagnet, sizeable skyrmion deformations
can be induced with relatively small induced anisotropy constants and thus a
wide range of tuneability can be achieved. We also show analytically, that a
consequence of the skyrmion deformation can, under certain conditions cause a
skyrmion deflection with respect to driving-current angles, unrelated to the
topological charge. Results are analyzed by a combination of micromagnetic
simulations and a compound particle description within the Thiele-formalism
from which an over-all mobility tensor is constructed. This work offers an
additional path towards in-situ tuning of skyrmion dynamics.",1807.06884v2
2018-08-13,Application of two-sublattice bilinearly coupled Heisenberg model to the description of certain ferrimagnetic materials,"We study phenomenologically on the basis of two bilinearly coupled Heisen-
berg models the phase diagram of some ferrimagnetic substances. Calculations
are performed with the help of Landau energy obtained through applying the
Hubbard-Stratonovich transformation to the initial microscopic Heisenberg
Hamiltonian. The phase transitions within the model are of second order with
the emergence of a compensation point at lower temperatures for some values of
parameters of the system. The main phase is a two-sublattice collinear
ferrimagnet but also a metastable non-collinear phase is present within the
exchange approximation presented here. The numerical results give a detailed
description of temperature dependence of magnetization on the strength of in-
tersublattice interaction and the difference between the effective exchanges of
two ferromagnetically ordered sublattices.",1808.04326v1
2019-01-10,Ultrafast magnetization dynamics in uniaxial ferrimagnets with compensation point. GdFeCo,"We derive an effective Lagrangian in the quasi-antiferromagnetic
approximation that allows to describe the magnetization dynamics for uniaxial
f-d (rare-earth - transition metal) ferrimagnet near the magnetization
compensation point in the presence of external magnetic field. We perform
calculations for the parameters of GdFeCo, a metallic ferrimagnet with
compensation point that is one of the most promising materials in ultrafast
magnetism. Using the developed approach, we find the torque that acts on the
magnetization due to ultrafast demagnetization pulse that can be caused either
by ultrashort laser or electrical current pulse. We show that the torque is
non-zero only in the non-collinear magnetic phase that can be acquired by
applying external magnetic field to the material. The coherent response of
magnetization dynamics amplitude and its timescale exhibits critical behavior
near certain values of the magnetic field corresponding to a spin-flop like
phase transition. Understanding the underlying mechanisms for these effects
opens the way to efficient control of the amplitude and the timescales of the
spin dynamics, which is one of the central problems in the field of ultrafast
magnetism.",1901.03072v2
2019-01-28,"Structural, magnetic, and electrical properties of collinear antiferromagnetic heteroepitaxy cubic Mn$_3$Ga thin films","Although a cubic phase of Mn$_3$Ga with an antiferromagnetic order has been
theoretically predicted, it has not been experimentally verified in a bulk or
film form. Here, we report the structural, magnetic, and electrical properties
of antiferromagnetic cubic Mn$_3$Ga (C-Mn$_3$Ga) thin films, in comparison with
ferrimagnetic tetragonal Mn$_3$Ga (T-Mn3Ga). The structural analyses reveal
that C-Mn$_3$Ga is hetero-epitaxially grown on MgO substrate with the
Cu$_3$Au-type cubic structure, which transforms to T-Mn$_3$Ga as the RF
sputtering power increases. The magnetic and magnetotransport data show the
antiferromagnetic transition at T$_N$ = 400 K for C-Mn$_3$Ga and the
ferrimagnetic transition at T$_C$ = 820 K for T-Mn$_3$Ga. Furthermore, we find
that the antiferromagnetic C-Mn$_3$Ga exhibits a higher electrical resistivity
than the ferrimagnetic T-Mn$_3$Ga, which can be understood by spin-dependent
scattering mechanism.",1901.09524v1
2019-03-01,Entangling two magnon modes via magnetostrictive interaction,"We present a scheme to entangle two magnon modes in a cavity magnomechanical
system. The two magnon modes are embodied by collective motions of a large
number of spins in two macroscopic ferrimagnets, and couple to a single
microwave cavity mode via magnetic dipole interaction. We show that by
activating the nonlinear magnetostrictive interaction in one ferrimagnet,
realized by driving the magnon mode with a strong red-detuned microwave field,
the two magnon modes can be prepared in an entangled state. The entanglement is
achieved by exploiting the nonlinear magnon-phonon coupling and the linear
magnon-cavity coupling, and is in the steady state and robust against
temperature. The entangled magnon modes in two massive ferrimagnets represent
genuinely macroscopic quantum states, and may find applications in the study of
macroscopic quantum mechanics and quantum information processing based on
magnonics.",1903.00221v2
2019-04-26,Blueprint for deterministic all-optical switching of magnetization,"We resolve a significant controversy about how to understand and engineer
single-shot all-optical switching of magnetization in ferrimagnets using femto-
or picosecond-long heat pulses. By realistically modelling a generic
ferrimagnet as two coupled macrospins, we comprehensively show that the net
magnetization can be reversed via different pathways, using a heat pulse with
duration spanning all relevant timescales within the non-adiabatic limit. This
conceptual understanding is fully validated by experiments studying the
material and optical limits at which the switching process in GdFeCo alloys
loses its reliability. Our interpretation and results constitute a blueprint
for understanding how deterministic all-optical switching can be achieved in
alternative ferrimagnets using short thermal pulses.",1904.11977v1
2019-11-06,Enhancement of domain-wall mobility detected by NMR at the angular momentum compensation temperature,"The angular momentum compensation temperature $T_{\rm A}$ of ferrimagnets has
attracted much attention because of high-speed magnetic dynamics near $T_{\rm
A}$. We show that NMR can be used to investigate domain wall dynamics near
$T_{\rm A}$ in ferrimagnets. We performed $^{57}$Fe-NMR measurements on the
ferrimagnet Ho$_3$Fe$_5$O$_{12}$ with $T_{\rm A} = 245$ K. In a multi-domain
state, the NMR signal is enhanced by domain wall motion. We found that the NMR
signal enhancement shows a maximum at $T_{\rm A}$ in the multi-domain state.
The NMR signal enhancement occurs due to increasing domain-wall mobility toward
$T_{\rm A}$. We develop the NMR signal enhancement model involves domain-wall
mobility. Our study shows that NMR in multi-domain state is a powerful tool to
determine $T_{\rm A}$, even from a powder sample and it expands the possibility
of searching for angular momentum-compensated materials.",1911.02207v3
2020-08-03,Observation of compact ferrimagnetic skyrmions in DyCo$_3$ film,"Owing to the experimental discovery of magnetic skyrmions stabilized by the
Dzyaloshinskii-Moriya and/or dipolar interactions in thin films, there is a
recent upsurge of interest in magnetic skyrmions with antiferromagnetic spins
in order to overcome the fundamental limitations inherent with skyrmions in
ferromagnetic materials. Here, we report on the observation of compact
ferrimagnetic skyrmions for the class of amorphous alloys consisting of 4f
rare-earth and 3d transition-metal elements with perpendicular magnetic
anisotropy, using a DyCo$_3$ film, that are identified by combining x-ray
magnetic scattering, scanning transmission x-ray microscopy, and Hall transport
technique. These skyrmions, with antiparallel aligned Dy and Co magnetic
moments and a characteristic core radius of about 40~nm, are formed during the
nucleation and annihilation of the magnetic maze-like domain pattern exhibiting
a topological Hall effect contribution. Our findings provide a promising route
for fundamental research in the field of ferrimagnetic/antiferromagnetic
spintronics towards practical applications.",2008.00725v1
2020-10-13,Effects of spin-orbit torque on the ferromagnetic and exchange spin wave modes in ferrimagnetic CoGd alloy,"We use micro-focus Brillouin light scattering spectroscopy to study the
effects of spin-orbit torque on thermal spin waves in almost angular-momentum
compensated ferrimagnetic CoGd alloy films. The spin-orbit torque is produced
by the electric current flowing in the Pt layer adjacent to CoGd. Both the
ferromagnetic and the exchange modes are detected in our measurements. The
intensity and the linewidth of the ferromagnetic mode are modified by the
spin-orbit torque. In contrast, the properties of the exchange mode are
unaffected by the spin-orbit torque. We also find that the frequencies and the
linewidths of both modes are significantly modified by Joule heating, due to
the strong temperature dependence of the magnetic properties of CoGd in the
vicinity of angular momentum compensation point. Our results provide insight
into the mechanisms that can enable the implementation of sub-THz magnetic
nano-oscillators based on ferrimagnetic materials, as well as related effects
in antiferromagnets.",2010.06615v1
2020-11-03,An attempt to simulate laser-induced all-optical spin switching in a crystalline ferrimagnet,"Interest in all-optical spin switching (AOS) is growing rapidly. The recent
discovery of AOS in Mn$_2$RuGa provides a much needed clean case of crystalline
ferrimagnets for theoretical simulations. Here, we attempt to simulate it using
the state-of-the-art first-principles method combined with the Heisenberg
exchange model. We first compute the spin moments at two inequivalent manganese
sites and then feed them into our model Hamiltonian. We employ an ultrafast
laser pulse to switch the spins. We find that there is a similar optimal laser
field amplitude to switch spins. However, we find that the exchange interaction
has a significant effect on the system switchability. Weakening the exchange
interaction could make the system unswitchable. This provides a crucial insight
into the switching mechanism in ferrimagnets.",2011.02001v1
2021-02-01,Real-time Hall-effect detection of current-induced magnetization dynamics in ferrimagnets,"Measurements of the transverse Hall resistance are widely used to investigate
electron transport, magnetization phenomena, and topological quantum states.
Owing to the difficulty of probing transient changes of the transverse
resistance, the vast majority of Hall effect experiments are carried out in
stationary conditions using either dc or ac currents. Here we present an
approach to perform time-resolved measurements of the transient Hall resistance
during current-pulse injection with sub-nanosecond temporal resolution. We
apply this technique to investigate in real-time the magnetization reversal
caused by spin-orbit torques in ferrimagnetic GdFeCo dots. Single-shot Hall
effect measurements show that the current-induced switching of GdFeCo is widely
distributed in time and characterized by significant activation delays, which
limit the total switching speed despite the high domain-wall velocity typical
of ferrimagnets. Our method applies to a broad range of current-induced
phenomena and can be combined with non-electrical excitations to perform
pump-probe Hall effect measurements.",2102.00716v1
2021-02-03,Infinite Series of Ferrimagnetic Phases Emergent from the Gapless Spin Liquid Phase of Mixed Diamond Chains,"The ground-state phases of mixed diamond chains with ($S, \tau^{(1)},
\tau^{(2)})=(1/2,1/2,1)$, where $S$ is the magnitude of vertex spins, and
$\tau^{(1)}$ and $\tau^{(2)}$ are those of apical spins, are investigated. The
apical spins $\tau^{(1)}$ and $\tau^{(2)}$ are connected with each other by an
exchange coupling $\lambda$. Other exchange couplings are set equal to unity.
This model has an infinite number of local conservation laws. For large
$\lambda$, the ground state is equivalent to that of the uniform spin $1/2$
chain. Hence, the ground state is a gapless spin liquid. For $\lambda \leq 0$,
the ground state is a Lieb-Mattis ferrimagnetic phase with spontaneous
magnetization $m_{\rm sp}=1$ per unit cell. For intermediate $\lambda$, we find
a series of ferrimagnetic phases with $m_{\rm sp}=1/p$ where $p$ takes positive
integer values. The phases with $p \geq 2$ are accompanied by the spontaneous
breakdown of the $p$-fold translational symmetry. It is suggested that the
phase with arbitrarily large $p$, namely infinitesimal spontaneous
magnetization, is allowed as $\lambda$ approaches the transition point to the
gapless spin liquid phase.",2102.02116v2
2021-02-22,"The role of density-dependent magnon hopping and magnon-magnon repulsion in ferrimagnetic spin-(1/2, $S$) chains in a magnetic field","We compare the ground-state features of alternating ferrimagnetic chains
$(1/2, S)$ with $S=1,3/2,2,5/2$ in a magnetic field and the corresponding
Holstein-Primakoff bosonic models up to order $\sqrt{s/S}$, with $s=1/2$,
considering the fully polarized magnetization as the boson vacuum. {The
single-particle Hamiltonian is a Rice-Mele model with uniform hopping and
modified boundaries, while the interactions have a correlated
(density-dependent) hopping term and magnon-magnon repulsion.} The
magnon-magnon repulsion increases the many-magnon energy and the
density-dependent hopping decreases the kinetic energy. We use density matrix
renormalization group calculations to investigate the effects of these two
interaction terms in the bosonic model{, and display the quantitative agreement
between the results from the spin model and the full bosonic approximation. In
particular, we verify the good accordance in the behavior of the edge states,
associated with the ferrimagnetic plateau, from the spin and from the bosonic
models. Furthermore, we show that the boundary magnon density strongly depends
on the interactions and particle statistics.",2102.11143v1
2021-03-03,THz Field-induced Spin Dynamics in Ferrimagnetic Iron Garnets,"THz magnetization dynamics is excited in ferrimagnetic thulium iron garnet
with a picosecond, single-cycle magnetic field pulse and seen as a
high-frequency modulation of the magneto-optical Faraday effect. Data analysis
combined with numerical modelling and evaluation of the effective Lagrangian
allow us to conclude that the dynamics corresponds to the exchange mode excited
by Zeeman interaction of the THz field with the antiferromagnetically coupled
spins. We argue that THz-pump IR-probe experiments on ferrimagnets offer a
unique tool for quantitative studies of dynamics and mechanisms to control
antiferromagnetically coupled spins.",2103.02449v1
2021-03-19,Domain wall dynamics of ferrimagnets induced by spin-current near the angular momentum compensation temperature,"We report on a theoretical study of the spin-current excited dynamics of
domain walls (DWs) in ferrimagnets in the vicinity of the angular momentum
compensation point. Effective Lagrangian and nonlinear dynamic equations are
derived for a two-sublattice ferrimagnet taking into account both spin-torques
and external magnetic field. The dynamics of the DW before and after the Walker
breakdown is calculated for any direction of the spin current polarization. It
is shown that for the in-plane polarization of the spin current, the DW
mobility reaches a maximum near the temperature of the angular momentum
compensation. For the out-of-plane spin polarization, in contrast, a spin
current with the densities below the Walker breakdown does not excite the
dynamics of the DW. After overcoming the Walker breakdown, the domain wall
velocity increases linearly with increasing the current density. In this
spin-current polarization configuration the possibility of a gigahertz
oscillation dynamics of the quasi-antiferromagnetic vector under the action of
a damping-like torque in the angular momentum compensation point is
demonstrated. Possible structures for experimental demonstration of the
considered effects are discussed.",2103.10711v1
2021-06-18,Atomistic spin model of single pulse toggle switching in Mn$_2$Ru$_x$Ga Heusler alloys,"Single femtosecond pulse toggle switching of ferrimagnetic alloys is an
essential building block for ultrafast spintronics. Very different
element-specific demagnetization dynamics is believed to be a hard limit for
switching in ferrimagnets. This suggests that ferrimagnets composed of two ions
of different nature, such as rare earth transition metal alloys, are necessary
for switching. However, experimental observation of toggle switching in
Mn$_2$Ru$_x$Ga Heusler alloys, has contested this limit since Mn ions are of
the same nature. To shed some light into this question, we present an atomistic
spin model for the simulation of single pulse toggle switching of
Mn$_2$Ru$_x$Ga. The magnetic parameters entering in our model are extracted
from previous experimental observations. We show that our model is able to
quantitatively reproduce measured magnetization dynamics of single pulse toggle
switching. We demonstrate that differently to previous understanding toggle
switching in Mn$_2$Ru$_x$Ga is possible even when both Mn sublattices
demagnetization at very similar rate.",2106.10111v2
2021-10-27,Low temperature competing magnetic energy scales in the topological ferrimagnet TbMn6Sn6,"TbMn6Sn6 is a metallic ferrimagnet displaying signatures of both topological
electrons and topological magnons arising from ferromagnetism and spin-orbit
coupling within its Mn kagome layers. Inelastic neutron scattering measurements
find strong ferromagnetic (FM) interactions within the Mn kagome layer and
reveal a magnetic bandwidth of ~230 meV. The low-energy magnetic excitations
are characterized by strong FM Mn-Mn and antiferromagnetic (AFM) Mn-Tb
interlayer magnetic couplings. We observe weaker, competing long-range FM and
AFM Mn-Mn interlayer interactions similar to those driving helical magnetism in
the YMn6Sn6 system. Combined with density-functional theory calculations, we
find that competing Mn-Mn interlayer magnetic interactions occur in all RMn6Sn6
compounds with R= Y, Gd-Lu, resulting in magnetic instabilities and tunability
when Mn-R interactions are weak. In the case of TbMn6Sn6, strong AFM Mn-Tb
coupling ensures a highly stable three-dimensional ferrimagnetic network.",2110.14713v2
2022-01-11,Nonreciprocal dynamics of ferrimagnetic bimerons,"Magnetic bimerons are topologically nontrivial spin textures in in-plane
easy-axis magnets, which can be used as particle-like information carriers.
Here, we report a theoretical study on the nonreciprocal dynamics of
asymmetrical ferrimagnetic (FiM) bimerons induced by spin currents. The FiM
bimerons have the ability to move at a speed of kilometers per second and do
not show the skyrmion Hall effect at the angular momentum compensation point.
Our micromagnetic simulations and analytical results demonstrate that spin
currents are able to induce the nonreciprocal transport and a drift motion of
the FiM bimeron even if the system is at the angular momentum compensation
point. By analyzing the current-induced effective fields, we find that the
nonreciprocal transport is attributed to the asymmetry of the bimeron
structure. Our results are useful for understanding the physics of bimerons in
ferrimagnets and may provide guidelines for building bimeron-based spintronic
devices.",2201.03781v1
2022-03-17,Rare-earth-free noncollinear metallic ferrimagnets Mn4-xZxN with compensation at room temperature,"Compensated ferrimagnets, like antiferromagnets, show no net magnetization
but their transport and magneto-optic properties resemble those of
ferromagnets, thereby creating opportunities for applications in high-frequency
spintronics and low-energy loss communications. Here we study the modification
the noncollinear ferrimagnetic spin structure of Mn4N by a variety of metallic
substitutions Z (Z = Cu - Ge and Ag - Sn) to achieve compensation at room
temperature. The noncollinear frustrated 2.35 Bohr magneton moments of Mn on 3c
sites of the (111) kagome planes tilt about 20 degree out-of-plane in Mn4N and
are easily influenced by the substitutions on 1a sites, leading to different
efficiency of compensation in Mn4-xZxN that increases gradually from group 11
(Cu, Ag) to group 14 (Ge, Sn) with increasing number of valance electrons.
Elements from the 5th period are more efficient for compensation than those
from the 4th period due to lattice expansion. The manganese site moments are
determined by Z, orbital hybridization, charge transfer and the tilt angle,
analyzed by constrained density functional theory. The Ga compound with
compensation at room temperature for x = 0.26 is recommended for high-frequency
spintronic applications.",2203.09641v1
2022-04-04,Towards high all-optical data writing rates in synthetic ferrimagnets,"Although all-optical magnetization switching with fs laser pulses has
garnered much technological interest, the ultimate data rates achievable have
scarcely been investigated. Recently it has been shown that after a switching
event in a GdCo alloy, a second laser pulse arriving 7 ps later can
consistently switch the magnetization. However, it is as of yet unknown whether
the same holds in layered ferrimagnetic systems, which hold much promise for
applications. In this work we investigate the minimum time delay required
between two subsequent switching events in synthetic ferrimagnetic Co/Gd
bilayers using two fs laser pulses. We experimentally demonstrate that the
minimum time delay needed for consistent switching can be as low as 10 ps.
Moreover, we demonstrate the importance of engineering heat diffusion away from
the magnetic material, as well as control over the laser pulse power. This
behavior is reproduced using modelling, where we find that the second switch
can occur even when the magnetization is not fully recovered. We further
confirm that heat diffusion is a critical factor in reducing the time delay for
the second switch, while also confirming a critical dependence on laser power.",2204.01459v1
2022-05-06,Interband magnon drag in ferrimagnetic insulators,"We propose a new drag phenomenon, an interband magnon drag, and report on
interaction effects and multiband effects in magnon transport of ferrimagnetic
insulators. We study a spin-Seebeck coefficient $S_{\textrm{m}}$, a magnon
conductivity $\sigma_{\textrm{m}}$, and a magnon thermal conductivity
$\kappa_{\textrm{m}}$ of interacting magnons for a minimal model of
ferrimagnetic insulators using a $1/S$ expansion of the Holstein-Primakoff
method, the linear-response theory, and a method of Green's functions. We show
that the interband magnon drag enhances $\sigma_{\textrm{m}}$ and reduces
$\kappa_{\textrm{m}}$, whereas its total effects on $S_{\textrm{m}}$ are small.
This drag results from the interband momentum transfer induced by the
magnon-magnon interactions. We also show that the higher-energy band magnons
contribute to $S_{\textrm{m}}$, $\sigma_{\textrm{m}}$, and
$\kappa_{\textrm{m}}$ even for temperatures smaller than the energy difference
between the two bands.",2205.03058v1
2022-06-27,Bridging atomistic spin dynamics methods and phenomenological models of single pulse ultrafast switching in ferrimagnets,"We bridge an essential knowledge gap on the understanding of all-optical
ultrafast switching in ferrimagnets; namely, the connection between atomistic
spin dynamics methods and macroscopic phenomenological models. All-optical
switching of the magnetization occurs after the application of a single
femtosecond laser pulse to specific ferrimagnetic compounds. This strong
excitation puts the involved degrees of freedom, electrons, lattice and spins
out-of-equilibrium between each other. Atomistic spin models have
quantitatively described all-optical switching in a wide range of experimental
conditions, while having failed to provide a simple picture of the switching
process. Phenomenological models are able to qualitatively describe the
dynamics of the switching process. However, a unified theoretical framework is
missing that describes the element-specific spin dynamics as atomistic spin
models with the simplicity of phenomenology. Here, we bridge this gap and
present an element-specific macrospin dynamical model which fully agrees with
atomistic spin dynamics simulations and symmetry considerations of the
phenomenological models.",2206.13593v1
2022-09-21,Effect of Co Substitution on Ferrimagnetic Heusler compound Mn3Ga,"Effect of Co substitution on Mn$_3$Ga is investigated using first-principles
study for structural and magnetic properties. Without Co, ferrimagnetic Heusler
compound Mn3Ga is in tetragonal phase. With Co substitution, depending on Co
concentration (x) Mn$_3$Ga prefers tetragonal (cubic) phase when x \leq 0.5 (x
\geq 0.5). Ferrimagnetism is robust regardless of x in both phases. While
magnetic moments of two Mn do not vary significantly with x, Co magnetic moment
in two phases exhibit different behaviors, leading to distinct features in
total magnetic moment (M_{tot}). When x \leq 0.5, in tetragonal phase, Co
magnetic moment is vanishingly small, resulting in a decrease of M_{tot} with
x. In contrast, when x \geq 0.5, in cubic phase, Co magnetic moment is roughly
1$\mu_B$, which is responsible for an increase of Mtot. Electronic structure is
analyzed with partial density of states for various x. To elucidate the
counterintuitively small Co moment, the magnetic exchange interaction is
investigated where exchange coefficient between Co and Mn is much smaller in x
\leq 0.5 case than x \geq 0.5 one.",2209.10216v1
2022-09-23,Magnetostatics of Room Temperature Compensated Co/Gd/Co/Gd-based Synthetic Ferrimagnets,"Flexibility for interface engineering, and access to all-optical switching of
the magnetization, make synthetic ferrimagnets an interesting candidate for
advanced opto-spintronic devices. Moreover, due to their layered structure and
disordered interfaces they also bear promise for the emerging field of graded
magnetic materials. The fastest and most efficient spin-orbit torque driven
manipulation of the magnetic order in this material system generally takes
place at compensation. Here, we present a systematic experimental and modeling
study of the conditions for magnetization compensation and perpendicular
magnetic anisotropy in the synthetic ferrimagnetic Co/Gd/Co/Gd system. A model
based on partial intermixing at the Co/Gd interfaces of this system has been
developed which explains the experiments well, and provides a new tool to
understand its magnetic characteristics. More specifically, this work provides
new insight in the decay of the Co proximity-induced magnetization in the Gd,
and the role the capping layer plays in the Gd magnetization.",2209.11562v1
2022-10-04,Local density of states as a probe for tunneling magnetoresistance effect: application to ferrimagnetic tunnel junctions,"We investigate the tunneling magnetoresistance (TMR) effect using the lattice
models which describe the magnetic tunnel junctions (MTJ). First, taking a
conventional ferromagnetic MTJ as an example, we show that the product of the
local density of states (LDOS) at the center of the barrier traces the TMR
effect qualitatively. The LDOS inside the barrier has the information on the
electrodes and the electron tunneling through the barrier, which enables us to
easily evaluate the tunneling conductance more precisely than the conventional
Julliere's picture. We then apply this method to the MTJs with collinear
ferrimagnets and antiferromagnets. We find that the TMR effect in the
ferrimagnetic and antiferromagnetic MTJs changes depending on the interfacial
magnetic structures originating from the sublattice structure, which can also
be captured by the LDOS. Our findings will reduce the computational cost for
the qualitative evaluation of the TMR effect, and be useful for a broader
search for the materials which work as the TMR devices showing high
performance.",2210.01441v1
2022-10-20,Strong variation of spin-orbit torques with relative spin relaxation rates in ferrimagnets,"Spin-orbit torques (SOTs) have been widely understood as an interfacial
transfer of spin that is independent of the bulk properties of the magnetic
layer. Here, we report that SOTs acting on ferrimagnetic FexTb1-x layers
decrease and vanish upon approaching the magnetic compensation point because
the rate of spin transfer to the magnetization becomes slower than the rate of
spin relaxation into the crystal lattice due to spin-orbit scattering. These
results indicate that the relative rates of competing spin relaxation processes
within magnetic layers play a critical role in determining the strength of
SOTs, which provides a unified understanding for the diverse and even seemingly
puzzling SOT phenomena in ferromagnetic and compensated systems. Our work
indicates that spin-orbit scattering within the magnet should be minimized for
efficient SOT devices. We also find that the interfacial spin-mixing
conductance of interfaces of ferrimagnetic alloys (such as FexTb1-x) is as
large as that of 3d ferromagnets and insensitive to the degree of magnetic
compensation.",2210.11042v1
2022-12-06,Dynamics of hybrid magnetic skyrmion driven by spin-orbit torque in ferrimagnets,"Magnetic skyrmions are magnetic textures with topological protection, which
are expected to be information carriers in future spintronic devices. In this
work, we propose a scheme to implement hybrid magnetic skyrmions (HMS) in
ferrimagnets, and we study theoretically and numerically the dynamics of the
HMS driven by spin-orbit torque. It is revealed that the skyrmion Hall effect
depends on the skyrmion helicity and the net angular momentum ({\delta}s),
allowing the effective modulation of the HMS motion through tuning
Dzyaloshinskii-Moriya interaction and {\delta}s. Thus, the Hall effect can be
suppressed through selecting suitable materials to better control the HMS
motion. Moreover, Magnus force for finite {\delta}s suppresses the transverse
motion and enhances the longitudinal propagation, resulting in the HMS dynamics
in ferrimagnets faster than that in antiferromagnets.",2212.02807v1
2023-03-21,Unveiling the magnetic structure and phase transition of Cr$_2$CoAl using neutron diffraction,"We report the detailed analysis of temperature dependent neutron diffraction
pattern of the Cr$_2$CoAl inverse Heusler alloy and unveil the magnetic
structure up to the phase transition as well as its fully compensated
ferrimagnetic nature. The Rietveld refinement of the diffraction pattern using
the space group I$\bar4${\it m}2 confirm the inverse tetragonal structure over
the large temperature range from 100~K to 900~K. The refinement of the magnetic
phase considering the wave vector $k=$ (0, 0, 0) reveals the ferrimagnetic
nature of the sample below 730$\pm$5~K. This transition temperature is obtained
from empirical power law fitting of the variation in the ordered net magnetic
moment and intensity of (110) peak as a function of temperature. The spin
configuration of the microscopic magnetic structure suggests the nearly fully
compensated ferrimagnetic behavior where the magnetic moments of Cr2 are
antiparallel with respect to the Cr1, and Co moments. Moreover, the observed
anomaly in the thermal expansion and lattice parameters at 730$\pm$5~K suggest
that the distortion in crystal structure may play an important role in the
magnetic phase transition.",2303.11869v1
2023-03-26,Strong lateral exchange coupling and current-induced switching in single-layer ferrimagnetic films with patterned compensation temperature,"Strong, adjustable magnetic couplings are of great importance to all devices
based on magnetic materials. Controlling the coupling between adjacent regions
of a single magnetic layer, however, is challenging. In this work, we
demonstrate strong exchange-based coupling between arbitrarily shaped regions
of a single ferrimagnetic layer. This is achieved by spatially patterning the
compensation temperature of the ferrimagnet by either oxidation or He+
irradiation. The coupling originates at the lateral interface between regions
with different compensation temperature and scales inversely with their width.
We show that this coupling generates large lateral exchange coupling fields and
we demonstrate its application to control the switching of magnetically
compensated dots with an electric current.",2303.14809v1
2023-07-10,Reversal of the skyrmion topological deflection across ferrimagnetic angular momentum compensation,"Due to their non-trivial topology, skyrmions describe deflected trajectories,
which hinders their straight propagation in nanotracks and can lead to their
annihilation at the track edges. This deflection is caused by a gyrotropic
force proportional to the topological charge and the angular momentum density
of the host film. In this article we present clear evidence of the reversal of
the topological deflection angle of skyrmions with the sign of angular momentum
density. We measured the skyrmion trajectories across the angular momentum
compensation temperature (TAC) in GdCo thin films, a rare earth/transition
metal ferrimagnetic alloy. The sample composition was used to engineer the
skyrmion stability below and above the TAC. A refined comparison of their
dynamical properties evidenced a reversal of the skyrmions deflection angle
with the total angular momentum density. This reversal is a clear demonstration
of the possibility of tuning the skyrmion deflection angle in ferrimagnetic
materials and paves the way for deflection-free skyrmion devices.",2307.04669v2
2023-08-23,Magnetic analogue of liquid-gas phase transition of water: case study of a spin-1/2 Ising-Heisenberg model on a diamond-decorated square lattice,"The spin-1/2 Ising-Heisenberg model on a diamond-decorated square lattice
exhibits an intriguing temperature-driven phase transition in a magnetic field
between a classical ferrimagnetic phase and a quantum monomer-dimer phase. A
generalized decoration-iteration transformation accurately maps the considered
model to an effective spin-1/2 Ising model on a square lattice with
temperature-dependent effective interactions and field, whereby the effective
field vanishes at the phase boundary separating the classical ferrimagnetic
phase from the quantum monomer-dimer phase. Typical features of the
magnetization, magnetic susceptibility and specific heat in the vicinity of
discontinuous and continuous thermal phase transitions between the classical
ferrimagnetic phase and the quantum monomer-dimer phase are elucidated.",2308.12410v1
2023-08-31,Tunable magnetic domains in ferrimagnetic MnSb$_2$Te$_4$,"Highly tunable properties make Mn(Bi,Sb)$_2$Te$_4$ a rich playground for
exploring the interplay between band topology and magnetism: On one end,
MnBi$_2$Te$_4$ is an antiferromagnetic topological insulator, while the
magnetic structure of MnSb$_2$Te$_4$ (MST) can be tuned between
antiferromagnetic and ferrimagnetic. Motivated to control electronic properties
through real-space magnetic textures, we use magnetic force microscopy (MFM) to
image the domains of ferrimagnetic MST. We find that magnetic field tunes
between stripe and bubble domain morphologies, raising the possibility of
topological spin textures. Moreover, we combine in situ transport with domain
manipulation and imaging to both write MST device properties and directly
measure the scaling of the Hall response with domain area. This work
demonstrates measurement of the local anomalous Hall response using MFM, and
opens the door to reconfigurable domain-based devices in the M(B,S)T family.",2308.16806v1
2023-09-05,Strong and nearly 100$\%$ spin-polarized second-harmonic generation from ferrimagnet Mn$_{2}$RuGa,"Second-harmonic generation (SHG) has emerged as a promising tool for
detecting electronic and magnetic structures in noncentrosymmetric materials,
but 100$\%$ spin-polarized SHG has not been reported. In this work, we
demonstrate nearly 100$\%$ spin-polarized SHG from half-metallic ferrimagnet
Mn$_{2}$RuGa. A band gap in the spin-down channel suppresses SHG, so the
spin-up channel contributes nearly all the signal, as large as 3614 pm/V about
10 times larger than that of GaAs. In the spin-up channel, $\chi_{xyz}^{(2)}$
is dominated by the large intraband current in three highly dispersed bands
near the Fermi level. With the spin-orbit coupling (SOC), the reduced magnetic
point group allows additional SHG components, where the interband contribution
is enhanced. Our finding is important as it predicts a large and complete
spin-polarized SHG in a all-optical spin switching ferrimagnet. This opens the
door for future applications.",2309.01965v1
2023-09-28,Magnetism and magnetocaloric properties of Co$_{1-x}$Mn$_x$Cr$_2$O$_4$,"Co$_{1-x}$Mn$_x$Cr$_2$O$_4$ crystallizes as a normal spinel in the cubic $Fd
\overline{3}m$ space group, and the end members have been reported to display a
region of collinear ferrimagnetism as well as a low-temperature spin-spiral
state with variable coherence lengths from 3 nm to 10 nm in polycrystalline
samples. Here, we present the synthesis of the entire solid solution, and data
showing that the ferrimagnetic ordering temperature as well as the spin-spiral
lock-in temperature are tunable with the Co/Mn ratio. The peak magnetocaloric
entropy change was determined to be $\Delta S_M$ = -5.63 J kg$^{-1}$ K$^{-1}$
in an applied magnetic field change of $\Delta H$ = 0 T to 5 T for the Mn
end-member at the ferrimagnetic ordering temperature. Using density functional
theory (DFT), we explore the shortcomings of the magnetic deformation proxy to
identify trends in $\Delta S_M$ across composition in this spinel system, and
explore future extensions of theory to address these discrepancies.",2309.16168v1
2023-11-13,Magnetoresistive detection of perpendicular switching in a magnetic insulator,"Spintronics offers promising routes for efficient memory, logic, and
computing technologies. The central challenge in spintronics is electrically
manipulating and detecting magnetic states in devices. The electrical control
of magnetization via spin-orbit torques is effective in both conducting and
insulating magnetic layers. However, the electrical readout of magnetization in
the latter is inherently difficult, limiting its use in practical applications.
Here, we demonstrate magnetoresistive detection of perpendicular magnetization
reversal in an electrically insulating ferrimagnet, terbium iron garnet (TbIG).
To do so, we use TbIG|Cu|TbCo, where TbCo is a conducting ferrimagnet and
serves as the reference layer, and Cu is a nonmagnetic spacer. Current
injection through Cu|TbCo allows us to detect the magnetization reversal of
TbIG with a simple resistance readout during an external magnetic field sweep.
By examining the effect of measurement temperature, TbCo composition, and Cu
thickness on the sign and amplitude of the magnetoresistance, we conclude that
the spin-dependent electron scattering at the TbIG|Cu interface is the
underlying cause. Technologically-feasible magnetoresistive detection of
perpendicular switching in a ferrimagnetic garnet is a breakthrough, as it
opens broad avenues for novel insulating spintronic devices and concepts.",2311.07350v1
2023-12-08,Convergent finite element methods for antiferromagnetic and ferrimagnetic materials,"We consider the numerical approximation of a continuum model of
antiferromagnetic and ferrimagnetic materials. The state of the material is
described in terms of two unit-length vector fields, which can be interpreted
as the magnetizations averaging the spins of two sublattices. For the static
setting, which requires the solution of a constrained energy minimization
problem, we introduce a discretization based on first-order finite elements and
prove its $\Gamma$-convergence. Then, we propose and analyze two iterative
algorithms for the computation of low-energy stationary points. The algorithms
are obtained from (semi-)implicit time discretizations of gradient flows of the
energy. Finally, we extend the algorithms to the dynamic setting, which
consists of a nonlinear system of two Landau-Lifshitz-Gilbert equations solved
by the two fields, and we prove unconditional stability and convergence of the
finite element approximations toward a weak solution of the problem. Numerical
experiments assess the performance of the algorithms and demonstrate their
applicability for the simulation of physical processes involving
antiferromagnetic and ferrimagnetic materials.",2312.04939v1
2023-12-21,Altermagnetic ferroelectric LiFe2F6 and spin-triplet excitonic insulator phase,"Altermagnetism is a new magnetic phase with k-dependent spin polarization and
may exist in an insulating state with a high N\'eel temperature. This provides
a new opportunity to obtain both spin and electric polarization in one
material. Here, based on symmetry analysis and the first-principles electronic
structures calculations, we predict that LiFe2F6 is a d-wave altermagnetic and
charge-ordering-mediated ferroelectric material. Moreover, the LiFe2F6
transforms into a ferrimagnetic and ferroelectric phase with strong
magnetoelectric coupling under biaxial compressive strain. Interestingly, the
spins of the valence band and the conduction band are opposite in ferrimagnetic
LiFe2F6, which facilitates a simultaneous spin-triplet excitonic insulator
phase. More importantly, the spin-triplet excitons with spin 1 and -1 can be
switched by electric fields in ferrimagnetic LiFe2F6 due to strong
magnetoelectric coupling. Due to the abundance of novel physical properties,
LiFe2F6 will certainly attract a wide range of theoretical and experimental
interest.",2312.13911v1
2024-01-16,Spin Waves in Ferrimagnets near the Angular Magnetization Compensation Temperature: A Micromagnetic Study,"Spin wave propagation along a ferrimagnetic strip with out-of-plane
magnetization is studied by means of micromagnetic simulations. The
ferrimagnetic material is considered as formed by two antiferromagnetically
coupled sublattices. Two critical temperatures can be defined for such systems:
that of magnetization compensation and that of angular momentum compensation,
both different due to distinct Land\'e factors for each sub-lattice. Spin waves
in the strip are excited by a spin current injected at one of its edges. The
obtained dispersion diagrams show exchange-dominated forward volume spin waves.
For a given excitation frequency, N\'eel vector describes highly eccentric
orbits, the eccentricity depending on temperature, whose semi-major axis are
oriented differently at distinct locations on the FiM strip.",2401.08235v1
2024-01-24,Current-Driven Domain Wall Motion in Curved Ferrimagnetic Strips Above and Below the Angular Momentum Compensation,"Current driven domain wall motion in curved Heavy Metal/Ferrimagnetic/Oxide
multilayer strips is investigated using systematic micromagnetic simulations
which account for spin-orbit coupling phenomena. Domain wall velocity and
characteristic relaxation times are studied as functions of the geometry,
curvature and width of the strip, at and out of the angular momentum
compensation. Results show that domain walls can propagate faster and without a
significant distortion in such strips in contrast to their ferromagnetic
counterparts. Using an artificial system based on a straight strip with an
equivalent current density distribution, we can discern its influence on the
wall terminal velocity, as part of a more general geometrical influence due to
the curved shape. Curved and narrow ferrimagnetic strips are promising
candidates for designing high speed and fast response spintronic circuitry
based on current-driven domain wall motion.",2401.13617v1
2024-03-11,Magnon bands and transverse transport in a proposed two-dimensional $Cu_2F_5$ ferrimagnet,"The copper fluoride $Cu_2F_5$ is a proposed stable compound that can be seen
as a layered magnetic lattice of $S=1$ and $S=1/2$ sites, corresponding to
copper ions. Intending to cast light on the transport properties of
ferrimagnetic magnons, we use the linear spin wave approach to study the magnon
band structure of the 2D lattice in a ferrimagnetic off-plane order, as well as
the transverse transport of magnons in the crystal bulk. That transverse
(Hall-like) transport can be induced by a magnetic field or temperature
gradient, and within the linear response theory is generated by the Berry
curvature of the eigenstates. As in most of the cases for magnons, the Berry
curvature here is related to Dzyaloshinskii-Moriya interactions between
next-near-neighbors. The band structure of the system is non-degenerate and the
transport coefficients are non-null. We also determine the condition for two
transport coefficients to change sign in response to temperature.",2403.07169v1
2018-10-24,Long spin coherence length and bulk-like spin-orbit torque in ferrimagnetic multilayers,"Ferromagnetic spintronics has been a main focus as it offers non-volatile
memory and logic applications through current-induced spin-transfer torques.
Enabling wider applications of such magnetic devices requires a lower switching
current for a smaller cell while keeping the thermal stability of magnetic
cells for non-volatility. As the cell size reduces, however, it becomes
extremely difficult to meet this requirement with ferromagnets because
spin-transfer torque for ferromagnets is a surface torque due to rapid spin
dephasing, leading to the 1/ferromagnet-thickness dependence of the spin-torque
efficiency. Requirement of a larger switching current for a thicker and thus
more thermally stable ferromagnetic cell is the fundamental obstacle for
high-density non-volatile applications with ferromagnets. Theories predicted
that antiferromagnets have a long spin coherence length due to the staggered
spin order on an atomic scale, thereby resolving the above fundamental
limitation. Despite several spin-torque experiments on antiferromagnets and
ferrimagnetic alloys, this prediction has remained unexplored. Here we report a
long spin coherence length and associated bulk-like-torque characteristic in an
antiferromagnetically coupled ferrimagnetic multilayer. We find that a
transverse spin current can pass through > 10 nm-thick ferrimagnetic Co/Tb
multilayers whereas it is entirely absorbed by 1 nm-thick ferromagnetic Co/Ni
multilayer. We also find that the switching efficiency of Co/Tb multilayers
partially reflects a bulk-like-torque characteristic as it increases with the
ferrimagnet-thickness up to 8 nm and then decreases, in clear contrast to
1/thickness-dependence of Co/Ni multilayers. Our results on
antiferromagnetically coupled systems will invigorate researches towards
energy-efficient spintronic technologies.",1810.10404v1
2020-09-12,Ferrimagnetic States of Na-K Alloy Clusters in Zeolite Low-Silica X,"In zeolite low-silica X (LSX), beta-cages with the inside diameter of approx
7 AA{} are arrayed in a diamond structure. Among them, supercages with the
inside diameter of approx 13 AA{} are formed and arrayed in a diamond structure
by the sharing of windows with the inside diameter of approx 8 AA{}. The
chemical formula of zeolite LSX used in the present study is given by
Na$_{x}$K$_{12-x}$Al$_{12}$Si$_{12}$O$_{48}$ per supercage (or beta-cage),
where Na$_{x}$K$_{12-x}$ and Al$_{12}$Si$_{12}$O$_{48}$ are the exchangeable
cations of zeolite LSX and the aluminosilicate framework, respectively. Na-K
alloy clusters are incorporated in these cages by the loading of guest K metal
at $n$K atoms per supercage (or beta-cage). A N'eel's N-type ferrimagnetism has
been observed at $n = 7.8$ for $x = 4$. In the present paper, optical, magnetic
and electrical properties are studied in detail mainly for $x = 4$.
Ferrimagnetic properties are observed at $6.5 < n < 8.5$. At the same time, the
Curie constant suddenly increases. An optical reflection band of beta-cage
clusters at 2.8 eV is observed at $n > 6.5$ in accordance with the sudden
increase in the Curie constant. An electrical resistivity indicates metallic
values at $n$ gtrapprox 6, because a metallic state is realized in the energy
band of supercage clusters. The ferrimagnetism is explained by the
antiferromagnetic interaction between the magnetic sublattice of itinerant
electron ferromagnetism at supercage clusters and that of localized moments at
beta-cage clusters. The electrical resistivity in ferrimagnetic samples at $n =
8.2$ for $x = 4$ increases extraordinarily at very low temperatures, such as
approx $10^6$ times larger than the value at higher temperatures. Observed
anomalies in the electrical resistivity resembles the Kondo insulator, but
itinerant electrons of narrow energy band of supercage clusters are
ferromagnetic.",2009.05742v1
2022-05-16,Ferrimagnetism in stable non-metal covalent organic framework,"We synthesized a pure organic non-metal crystalline covalent organic
framework TAPA-BTD-COF by bottom-up Schiff base chemical reaction. And this
imine-based COF is stable in aerobic condition and room-temperature. We
discovered that this TAPA-BTD-COF exhibited strong magneticity in 300 K
generating magnetic hysteresis loop in M-H characterization and giant chimol up
to 0.028. And we further conducted zero-field cooling and field-cooling
measurement of M-T curves. The as-synthesized materials showed a large chi/mol
up to 0.028 in 300 K and increasing to 0.037 in 4.0 K with 200 Oe measurement
field. The TAPA-BTD-COF 1/chimol~T curve supported its ferrimagnetism, with an
intrinsic delta temperature as -33.03 K by extrapolating the 1/chimol~T curve.
From the continuously increasing slope of 1/chimol~T, we consider that this
TAPA-BTD-COF belongs to ferrimagnetic other than antiferromagnetic materials.
And the large chimol value 0.028 at 300 K and 0.037 at 4.0 K also supported
this, since common antiferromagnetic materials possess chimol in the range of
10-5 to 10-3 as weak magnetics other than strong magnetic materials such as
ferrimagnetics and ferromagnetics. Since this material is purely non-metal
organic polymer, the possibility of d-block and f-block metal with
unpaired-electron induced magnetism can be excluded. Besides, since the COF
does not involve free-radical monomer in the processes of synthesis, we can
also exclude the origin of free-radical induced magnetism. According to recent
emerging flat-band strong correlated exotic electron property, this
unconventional phenomenon may relate to n-type doping on the flat-band locating
in the CBM, thus generating highly-localized electron with infinite effective
mass and exhibiting strong correlation, which accounts for this non-trivial
strong and stable ferrimagneticity at room-temperature and aerobic atmospheric
conditions.",2205.07541v1
1999-08-10,Existence of Saturated Ferromagnetic and Spiral States in 1D Lieb-Ferrimagnetic Models away from Half-Filling,"In order to study conditions for the appearance of ferromagnetism in a wide
filling region, we investigate numerically three types of one-dimensional
Lieb-ferrimagnetic Hubbard models: a periodic diamond (PD) chain, a periodic
alternately-attached leg (PAAL) chain and an open diamond (OD) chain. All of
these models have a flat band (or equivalently, degenerate single-electron
eigenvalues). The PD and OD chains commonly have a local-loop structure.
Nagaoka's theorem holds only in the PD chain. At half-filling, it have been
rigorously proven that all of these models are ferrimagnet. Away from
half-filling, however, quite different magnetic properties are found. In the
fillings 1/3< rho_e <1/2, the ground state of the PD chain for a
infinitely-large U is the extended ferromagnetic state, that is, the saturated
ferromagnetic state or the spiral state for odd or even number of electrons,
respectively. In the PAAL chain, on the other hand, there is no magnetic order.
Thus, the flat band is found to be not a sufficient condition of the extended
ferromagnetic state. We find, moreover, that the saturated ferromagnetism
appears in the OD chain, although the Nagaoka theorem does not hold on this
chain. This indicates that the local-loop structure plays an important role on
the appearance of the extended ferromagnetic state.",9908144v1
2005-05-04,From Finite-Size and Surface Effects to Glassy Behaviour in Ferrimagnetic Nanoparticles,"This chapter is aimed at studying the anomalous magnetic properties (glassy
behaviour) observed at low temperatures in nanoparticles of ferrimagnetic
oxides. This topic is discussed both from numerical results and experimental
data. Ferrimagnetic fine particles show most of the features of glassy systems
due to the random distribution of anisotropy axis, interparticle interactions
and surface effects. Experiments have shown that the hysteresis loops display
high closure fields with high values of the differential susceptibility. Low
magnetisation as compared to bulk, shifted loops after field-cooling, highfield
irreversibilities between zero-field and field cooling processes and ageing
phenomena in the time-dependence of the magnetisation, are also observed. This
phenomenology indicates the existence of some kind of freezing phenomenon
arising from a complex hierarchy of the energy levels, whose origin is
currently under discussion. Two models have been proposed to account for it: i)
the existence of a spin-glass state at the surface of the particle which is
coupled to the particle core through an exchange field; and ii) the collective
behaviour induced by interparticle interactions. In real systems, both
contributions simultaneously occur, being difficult to distinguish their
effects. In contrast, numerical simulations allow us to build a model just
containing the essential ingredients to study solely one of two phenomena.",0505112v1
2007-11-19,Probing phase coexistence and stabilization of the spin-ordered ferrimagnetic state by Calcium addition in the YBa_{1-x}Ca_{x}Co_{2}O_{5.5} layered cobaltites using neutron diffraction,"In this article we study the effects of a partial substitution of Ba with the
smaller cation Ca in the layered cobaltites YBaCo_2O_{5+\delta} for \delta
\approx 0.5. Neutron thermodiffractograms are reported for the compounds
YBa_{0.95}Ca_{0.05}Co_2O_{5.5} (x_{Ca}=0.05) and YBa_{0.90}Ca_{0.10}Co_2O_{5.5}
(x_{Ca}=0.10) in the temperature range 20 K \leq T \leq 300 K, as well as high
resolution neutron diffraction experiments at selected temperatures for the
samples x_{Ca}=0.05, x_{Ca}=0.10 and the parent compound x_{Ca}=0. We have
found the magnetic properties to be strongly affected by the cationic
substitution. Although the ""122"" perovskite structure seems unaffected by Ca
addition, the magnetic arrangements of Co ions are drastically modified: the
antiferromagnetic (AFM) long-range order is destroyed, and a ferrimagnetic
phase with spin state order is stabilized below T \sim 290 K. For the sample
with x_{Ca}=0.05 a fraction of AFM phase coexists with the ferrimagnetic one
below T \sim 190 K, whereas for x_{Ca}=0.10 the AFM order is completely lost.
The systematic refinement of the whole series has allowed for a better
understanding of the observed low-temperature diffraction patterns of the
parent compound, YBaCo_2O_{5.5}, which had not yet been clarified. A two-phase
scenario is proposed for the x_{Ca}=0 compound which is compatible with the
phase coexistence observed in the x_{Ca}=0.05 sample.",0711.3002v1
2008-09-15,Kinetics of a mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model,"We present a study, within a mean-field approach, of the kinetics of a mixed
ferrimagnetic model on a square lattice in which two interpenetrating square
sublattices have spins that can take two values, $\sigma=\pm1/2$, alternated
with spins that can take the four values, $S=\pm3/2, \pm1/2$. We use the
Glauber-type stochastic dynamics to describe the time evolution of the system
with a crystal-field interaction in the presence of a time-dependent
oscillating external magnetic field. The nature (continuous and discontinuous)
of transition is characterized by studying the thermal behaviors of average
order parameters in a period. The dynamic phase transition points are obtained
and the phase diagrams are presented in the reduced magnetic field amplitude
$(h)$ and reduced temperature $(T)$ plane, and in the reduced temperature and
interaction parameter planes, namely in the $(h, T)$ and $(d, T)$ planes, $d$
is the reduced crystal-field interaction. The phase diagrams always exhibit a
tricritical point in $(h, T)$ plane, but do not exhibit in the $(d, T)$ plane
for low values of $h$. The dynamic multicritical point or dynamic critical end
point exist in the $(d, T)$ plane for low values of $h$. Moreover, phase
diagrams contain paramagnetic $(p)$, ferromagnetic $(f)$, ferrimagnetic $(i)$
phases, two coexistence or mixed phase regions, $(f+p)$ and $(i+p)$, that
strongly depend on interaction parameters.",0809.2450v1
2011-03-10,"Phase diagram of the XXZ ferrimagnetic spin-(1/2, 1) chain in the presence of transverse magnetic field","We investigate the phase diagram of an anisotropic ferrimagnet spin-(1/2, 1)
in the presence of a non-commuting (transverse) magnetic field. We find a
magnetization plateau for the isotropic case while there is no plateau for the
anisotropic ferrimagnet. The magnetization plateau can appear only when the
Hamiltonian has the U(1) symmetry in the presence of the magnetic field. The
anisotropic model is driven by the magnetic field from the N\'{e}el phase for
low fields to the spin-flop phase for intermediate fields and then to the
paramagnetic phase for high fields. We find the quantum critical points and
their dependence on the anisotropy of the aforementioned field-induced quantum
phase transitions. The spin-flop phase corresponds to the spontaneous breaking
of Z2 symmetry. We use the numerical density matrix renormalization group and
analytic spin wave theory to find the phase diagram of the model. The energy
gap, sublattice magnetization, and total magnetization parallel and
perpendicular to the magnetic field are also calculated. The elementary
excitation spectrums of the model are obtained via the spin wave theory in the
three different regimes depending on the strength of the magnetic field.",1103.1967v2
2011-04-13,Optimized Effective Potential Model for the Double Perovskites Sr2-xYxVMoO6 and Sr2-xYxVTcO6,"In attempt to explore half-metallic properties of the double perovskites
Sr2-xYxVMoO6 and Sr2-xYxVTcO6, we construct an effective low-energy model,
which describes the behavior of the t2g-states of these compounds. All
parameters of such model are derived rigorously on the basis of
first-principles electronic structure calculations. In order to solve this
model we employ the optimized effective potential method and treat the
correlation interactions in the random phase approximation. Although
correlation interactions considerably reduce the intraatomic exchange splitting
in comparison with the Hartree-Fock method, this splitting still substantially
exceeds the typical values obtained in the local-spin-density approximation
(LSDA), which alters many predictions based on the LSDA. Our main results are
summarized as follows: (i) all ferromagnetic states are expected to be
half-metallic. However, their energies are generally higher than those of the
ferrimagnetic ordering between V- and Mo/Tc-sites (except Sr2VMoO6); (ii) all
ferrimagnetic states are metallic (except fully insulating Y2VTcO6) and no
half-metallic antiferromagnetism has been found; (iii) moreover, many of the
ferrimagnetic structures appear to be unstable with respect to the spin-spiral
alignment. Thus, the true magnetic ground state of the most of these systems is
expected to be more complex. In addition, we discuss several methodological
issues related to the nonuniqueness of the effective potential for the magnetic
half-metallic and insulating states.",1104.2399v1
2011-10-21,Exchange-spring behavior in bimagnetic CoFe2O4/CoFe2 nanocomposite,"In this work we report a study of the magnetic behavior of ferrimagnetic
oxide CoFe2O4 and ferrimagnetic oxide/ferromagnetic metal CoFe2O4/CoFe2
nanocomposites. The latter compound is a good system to study hard
ferrimagnet/soft ferromagnet exchange coupling. Two steps were used to
synthesize the bimagnetic CoFe2O4/CoFe2 nanocomposites: (i) first preparation
of CoFe2O4 nanoparticles using the a simple hydrothermal method and (ii) second
reduction reaction of cobalt ferrite nanoparticles using activated charcoal in
inert atmosphere and high temperature. The phase structures, particle sizes,
morphology, and magnetic properties of CoFe2O4 nanoparticles have been
investigated by X-Ray diffraction (XRD), Mossbauer spectroscopy (MS),
transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM)
with applied field up to 3.0 kOe at room temperature and 50K. The mean diameter
of CoFe2O4 particles is about 16 nm. Mossbauer spectra reveal two sites for
Fe3+. One site is related to Fe in an octahedral coordination and the other one
to the Fe3+ in a tetrahedral coordination, as expected for a spinel crystal
structure of CoFe2O4. TEM measurements of nanocomposite show the formation of a
thin shell of CoFe2 on the cobalt ferrite and indicate that the nanoparticles
increase to about 100 nm. The magnetization of nanocomposite showed hysteresis
loop that is characteristic of the exchange spring systems. A maximum energy
product (BH)max of 1.22 MGOe was achieved at room temperature for CoFe2O4/CoFe2
nanocomposites, which is about 115% higher than the value obtained for CoFe2O4
precursor. The exchange-spring interaction and the enhancement of product
(BH)max in nanocomposite CoFe2O4/CoFe2 have been discussed.",1110.4905v1
2012-06-28,Ferrimagnetic spin-1/2 chain of alternating Ising and Heisenberg spins in arbitrarily oriented magnetic field,"The ferrimagnetic spin-1/2 chain composed of alternating Ising and Heisenberg
spins in an arbitrarily oriented magnetic field is exactly solved using the
spin-rotation transformation and the transfer-matrix method. It is shown that
the low-temperature magnetization process depends basically on a spatial
orientation of the magnetic field. A sharp stepwise magnetization curve with a
marked intermediate plateau, which emerges for the magnetic field applied along
the easy-axis direction of the Ising spins, becomes smoother and the
intermediate plateau shrinks if the external field is tilted from the easy-axis
direction. The magnetization curve of a polycrystalline system is also
calculated by performing powder averaging of the derived magnetization formula.
The proposed spin-chain model brings an insight into high-field magnetization
data of 3d-4f bimetallic polymeric compound Dy(NO_3)(DMSO)_2Cu(opba)(DMSO)_2,
which provides an interesting experimental realization of the ferrimagnetic
chain composed of two different but regularly alternating spin-1/2 magnetic
ions Dy^{3+} and Cu^{2+} that are reasonably approximated by the notion of
Ising and Heisenberg spins, respectively.",1206.6656v2
2013-11-25,A study of crossover from 3D ferrimagnetic Bulk $NiCr_{2}O_{4}$ compound into 2D spin-glass like nanophase,"In this report, the magnetic behaviour of $NiCr_{2}O_{4}$ bulk and
nanoparticle samples under different applied magnetic field has been
investigated extensively. Nanoparticles of $NiCr_{2}O_{4}$ were obtained by
mechanical milling of polycrystalline powder prepared by polyol method. FC-ZFC
measurement of bulk at different applied magnetic field has revealed the
existence of a ferrimagnetic transition around 66K followed by an
antiferromagnetic transition close to 30K. However, its nano counterpart has
shown remarkable change in magnetic properties - a suppression of ferrimagnetic
transition accompanied by strengthening low temperature magnetic phase and
observation of a new transition at 90K ($T_P$), which is weakly magnetic in
nature. The frequency dependent ac susceptibility data of nanoparticle have
been fitted to the well known de Almedia-Thouless equation and a $H^{2/3}$
dependence of the low temperature peak is observed with a resulting zero field
freezing temperature ($T_f^0$) equal to 10.1K. Further, the dynamical behaviour
near freezing temperature has been analysed in terms of critical behaviour and
the obtained fitted parameters values being as $\tau_0$(relaxation time
constant) = $3.6 X 10^{-6}s$, $T_f^0=8.7$K and $z\nu = 11.1$. Moreover,
Vogel-Fulcher law has been used to understand the nature of freezing transition
and the parameter after fitting are obtained as $E_a/k_B = 58.9$K, $\tau_0 =
5.22 \times 10^{-8}$ and $T_0 = 8.03$K. Finally, the spin-glass phase is
concluded. Moreover, in contrast to bulk, the $H^{2/3}$ dependence of freezing
temperature of nanoparticle sample (75h) does support the 2D surface like spin
glass nature.",1311.6269v1
2014-01-07,Complex magnetic behavior of the sawtooth Fe chains in Rb$_{2}$Fe$_{2}$O(AsO$_{4}$)$_{2}$,"Results of magnetic field and temperature dependent neutron diffraction and
magnetization measurements on oxy-arsenate Rb$_{2}$Fe$_{2}$O(AsO$_{4}$)$_{2}$
are reported. The crystal structure of this compound contains
pseudo-one-dimensional [Fe$_{2}$O$_{6}$]$^\infty$ sawtooth-like chains, formed
by corner sharing isosceles triangles of $Fe^{3+}$ ions occupying two
nonequivalent crystallographic sites. The chains extend infinitely along the
crystallographic $b$-axis and are structurally confined from one another via
diamagnetic (AsO$_{4}$)$^{3-}$ units along the $a$-axis, and Rb$^+$ cations
along the $c$-axis direction. Neutron diffraction measurements indicate the
onset of a long range antiferromagnetic order below approximately 25 K. The
magnetic structure consists of ferrimagnetic chains which are
antiferromagnetically coupled with each other. Within each chain, one of the
two Fe sites carries a moment which lies along the \emph{b}-axis, while the
second site bears a canted moment in the opposite direction. Externally applied
magnetic field induces a transition to a ferrimagnetic state, in which the
coupling between the sawtooth chains becomes ferromagnetic. Magnetization
measurements performed on optically-aligned single crystals reveal evidence for
an uncompensated magnetization at low magnetic fields that could emerge from to
a phase-segregated state with ferrimagnetic inclusions or from
antiferromagnetic domain walls. The observed magnetic states and the
competition between them is expected to arise from strongly frustrated
interactions within the sawtooth chains and relatively weak coupling between
them.",1401.1539v1
2014-12-01,Coexistence of superconductivity and magnetism in spin-fermion model of ferrimagnetic spinel in an external magnetic field,"A two-sublattice spin-fermion model of ferrimagnetic spinel, with spin-$1/2$
itinerant electrons at the sublattice $A$ site and spin-$s$ localized electrons
at the sublattice $B$ site is considered. The exchange between itinerant and
localized electrons is antiferromanetic. As a result the external magnetic
field, applied along the magnetization of the localized electrons, compensates
the Zeeman splitting due to the spin-fermion exchange and magnon-fermion
interaction induces spin anti-parallel p-wave superconductivity which coexists
with magnetism. We have obtained five characteristic values of the applied
field (in units of energy) $H_{cr1}<H_3<H_0<H_4<H_{cr2}$. At $H_0$ the external
magnetic field compensates the Zeeman splitting. When $H_{cr1}<H<H_{cr2}$ the
spin antiparallel p-wave superconductivity with $T_{1u}$ configuration coexists
with magnetism. The superconductor to normal magnet transition at finite
temperature is second order when $H$ runs the interval $(H_3,H_4)$. It is an
abrupt transition when $H_{cr1}<H<H_3$ or $H_4<H<H_{cr2}$. This is proved
calculating the temperature dependence of the gap for three different values of
the external magnetic field $H_{cr1}<H<H_3$, $H_4<H<H_{cr2}$ and $H=H_0$. In
the first two cases the abrupt fall to zero of the gap at superconducting
critical temperature shows that the superconductor to normal magnet transition
is first order. The Hubbard term (Coulomb repulsion), in a weak coupling
regime, does not affect significantly the magnon induced superconductivity.
Relying on the above results one can formulate a recipe for preparing a
superconductor from ferrimagnetic spinel: i) hydrostatic pressure above the
critical value of insulator-metal transition. ii) external magnetic field along
the sublattice magnetization with higher amplitude.",1412.0450v1
2014-12-22,Frustration effects and role of selective exchange coupling for magnetic ordering in the Cairo pentagonal lattice,"The Cairo pentagonal lattice, consisting of an irregular pentagonal tiling of
magnetic ions on two inequivalent sites (3- and 4-co-ordinated ones),
represents a fascinating example for studying geometric frustration effects in
two-dimensions. In this work, we investigate the spin $S$ = $1/2$ Cairo
pentagonal lattice with respect to selective exchange coupling (which
effectively corresponds to a virtual doping of $x$ = $0, 1/6, 1/3$), in a
nearest-neighbour antiferromagnetic Ising model. We also develop a simple
method to quantify geometric frustration in terms of a frustration index
$\phi(\beta,T)$, where $\beta$ = $J/\tilde{J}$, the ratio of the two exchange
couplings required by the symmetry of the Cairo lattice. At $T = 0$, the
undoped Cairo pentagonal lattice shows antiferromagnetic ordering for $\beta
\le \beta_{crit} = 2$, but undergoes a first-order transition to a
ferrimagnetic phase for $\beta >$ $\beta_{crit}$. The results show that
$\phi(\beta,T = 0)$ tracks the transition in the form of a cusp maximum at
$\beta_{crit}$.
  While both phases show frustration, the obtained magnetic structures reveal
that the frustration originates in different bonds for the two phases. The
frustration and ferrimagnetic order get quenched by selective exchange
coupling, and lead to robust antiferromagnetic ordering for $x$ = 1/6 and 1/3.
From mean-field calculations, we determine the temperature-dependent
sub-lattice magnetizations for $x$ = $0, 1/6$ and $1/3$. The calculated results
are discussed in relation to known experimental results for trivalent
Bi$_2$Fe$_4$O$_9$ and mixed valent BiFe$_2$O$_{4.63}$. The study identifies the
role of frustration effects, the ratio $\beta$ and selective exchange coupling
for stabilizing ferrimagnetic versus anti-ferromagnetic order in the Cairo
pentagonal lattice.",1412.6944v1
2015-06-08,"Geometric, electronic and magnetic structure of Fe$_{x}$O$_{y}^{+}$ clusters","Correlation between geometry, electronic structure and magnetism of solids is
both intriguing and elusive. This is particularly strongly manifested in small
clusters, where a vast number of unusual structures appear. Here, we employ
density functional theory in combination with a genetic search algorithm,
GGA$+U$ and a hybrid functional to determine the structure of gas phase
Fe$_{x}$O$_{y}^{+/0}$ clusters. For Fe$_{x}$O$_{y}$ cation clusters we also
calculate the corresponding vibration spectra and compare them with
experiments. We successfully identify Fe$_{3}$O$_{4}^{+}$, Fe$_{4}$O$_{5}^{+}$,
Fe$_{4}$O$_{6}^{+}$, Fe$_{5}$O$_{7}^{+}$ and propose structures for
Fe$_{6}$O$_{8}^{+}$. Within the triangular geometric structure of
Fe$_{3}$O$_{4}^{+}$ a non-collinear, ferrimagnetic and ferromagnetic state are
comparable in energy. Fe$_{4}$O$_{5}^{+}$ and Fe$_{4}$O$_{6}^{+}$ are
ferrimagnetic with a residual magnetic moment of 1~\muB{} due to ionization.
Fe$_{5}$O$_{7}^{+}$ is ferrimagnetic due to the odd number of Fe atoms. We
compare the electronic structure with bulk magnetite and find
Fe$_{4}$O$_{5}^{+}$, Fe$_{4}$O$_{6}^{+}$, Fe$_{6}$O$_{8}^{+}$ to be mixed
valence clusters. In contrast, in Fe$_{3}$O$_{4}^{+}$ and Fe$_{5}$O$_{7}^{+}$
all Fe are found to be trivalent.",1506.02532v2
2015-06-22,Exchange scattering as the driving force for ultrafast all-optical and bias-controlled reversal in ferrimagnetic metallic structures,"Experimentally observed ultrafast all-optical magnetization reversal in
ferrimagnetic metals and heterostructures based on antiferromagnetically
coupled ferromagnetic $d-$ and $f-$metallic layers relies on intricate energy
and angular momentum flow between electrons, phonons and spins. Here we treat
the problem of angular momentum transfer in the course of ultrafast
laser-induced dynamics in a ferrimagnetic metallic system using microscopical
approach based on the system of rate equations. We show that the magnetization
reversal is supported by a coupling of $d-$ and $f-$ subsystems to delocalized
$s-$ or $p-$ electrons. The latter can transfer spin between the two subsystems
in an incoherent way owing to the $(s;p)-(d;f)$ exchange scattering. Since the
effect of the external excitation in this process is reduced to the transient
heating of the mobile electron subsystem, we also discuss possibility to
trigger the magnetization reversal by applying a voltage bias pulse to
antiferromagnetically coupled metallic ferromagnetic layers embedded in point
contact or tunneling structures. We argue that such devices allow controlling
reversal with high accuracy. We also suggest to use the anomalous Hall effect
to register the reversal, thus playing a role of reading probes.",1506.06585v3
2015-06-23,Design of compensated ferrimagnetic Heusler alloys for giant tunable exchange bias,"The discovery of materials with improved functionality can be accelerated by
rational material design. Heusler compounds with tunable magnetic sublattices
allow to implement this concept to achieve novel magnetic properties. Here, we
have designed a family of Heusler alloys with a compensated ferrimagnetic
state. In the vicinity of the compensation composition in Mn-Pt-Ga, a giant
exchange bias (EB) of more than 3 T and a similarly large coercivity are
established. The large exchange anisotropy originates from the exchange
interaction between the compensated host and ferrimagnetic clusters that arise
from intrinsic anti-site disorder. We demonstrate the applicability of our
design concept on a second material, Mn-Fe-Ga, with a magnetic transition above
room temperature, exemplifying the universality of the concept and the
feasibility of room-temperature applications. Our study points to a new
direction for novel magneto-electronic devices. At the same time it suggests a
new route for realizing rare-earth free exchange-biased hard magnets, where the
second quadrant magnetization can be stabilized by the exchange bias.",1506.07028v1
2015-10-17,Ferrimagnetic nanostructures for magnetic memory bits,"Increasing the magnetic data recording density requires reducing the size of
the individual memory elements of a recording layer as well as employing
magnetic materials with temperature-dependent functionalities. Therefore, it is
predicted that the near future of magnetic data storage technology involves a
combination of energy-assisted recording on nanometer-scale magnetic media. We
present the potential of heat-assisted magnetic recording on a patterned
sample; a ferrimagnetic alloy composed of a rare earth and a transition metal,
DyCo$_5$, which is grown on a hexagonal-ordered nanohole array membrane. The
magnetization of the antidot array sample is out-of-plane oriented at room
temperature and rotates towards in-plane upon heating above its
spin-reorientation temperature (T$_R$) of ~350 K, just above room temperature.
Upon cooling back to room temperature (below T$_R$), we observe a well-defined
and unexpected in-plane magnetic domain configuration modulating with ~45 nm.
We discuss the underlying mechanisms giving rise to this behavior by comparing
the magnetic properties of the patterned sample with the ones of its extended
thin film counterpart. Our results pave the way for novel applications of
ferrimagnetic antidot arrays of superior functionality in magnetic nano-devices
near room temperature.",1510.05087v1
2017-03-24,Electronic structure and direct observation of ferrimagnetism in multiferroic hexagonal YbFeO3,"The magnetic interaction between rare-earth and Fe ions in hexagonal
rare-earth ferrites (h-REFeO3), may amplify the weak ferromagnetic moment on
Fe, making these materials more appealing as multiferroics. To elucidate the
interaction strength between the rare-earth and Fe ions as well as the magnetic
moment of the rare-earth ions, element specific magnetic characterization is
needed. Using X-ray magnetic circular dichroism, we have studied the
ferrimagnetism in h-YbFeO3 by measuring the magnetization of Fe and Yb
separately. The results directly show anti-alignment of magnetization of Yb and
Fe ions in h-YbFeO3 at low temperature, with an exchange field on Yb of about
17 kOe. The magnetic moment of Yb is about 1.6 \muB at low-temperature,
significantly reduced compared with the 4.5 \muB moment of a free Yb3+. In
addition, the saturation magnetization of Fe in h-YbFeO3 has a sizable
enhancement compared with that in h-LuFeO3. These findings directly demonstrate
that ferrimagnetic order exists in h-YbFeO3; they also account for the
enhancement of magnetization and the reduction of coercivity in h-YbFeO3
compared with those in h-LuFeO3 at low temperature, suggesting an important
role for the rare-earth ions in tuning the multiferroic properties of h-REFeO3.",1703.08482v2
2018-02-12,Canted ferrimagnetism and giant coercivity in the non-stoichiometric double perovskite La2Ni1.19Os0.81O6,"The non-stoichiometric double perovskite oxide La2Ni1.19Os0.81O6 was
synthesized by solid state reaction and its crystal and magnetic structures
were investigated by powder x-ray and neutron diffraction. La2Ni1.19Os0.81O6
crystallizes in the monoclinic double perovskite structure (general formula
A2BB'O6) with space group P21/n, where the B site is fully occupied by Ni and
the B' site by 19 % Ni and 81 % Os atoms. Using x-ray absorption spectroscopy
an Os4.5+ oxidation state was established, suggesting presence of about 50 %
paramagnetic Os5+ (5d3, S = 3/2) and 50 % non-magnetic Os4+ (5d4, Jeff = 0)
ions at the B' sites. Magnetization and neutron diffraction measurements on
La2Ni1.19Os0.81O6 provide evidence for a ferrimagnetic transition at 125 K. The
analysis of the neutron data suggests a canted ferrimagnetic spin structure
with collinear Ni2+ spin chains extending along the c axis but a non-collinear
spin alignment within the ab plane. The magnetization curve of
La2Ni1.19Os0.81O6 features a hysteresis with a very high coercive field, HC =
41 kOe, at T = 5 K, which is explained in terms of large magnetocrystalline
anisotropy due to the presence of Os ions together with atomic disorder. Our
results are encouraging to search for rare earth free hard magnets in the class
of double perovskite oxides.",1802.03874v1
2013-08-16,Theory of metallic double perovskites with spin orbit coupling and strong correlations; application to ferrimagnetic Ba2FeReO6,"We consider a model of the double perovskite Ba2FeReO6, a room temperature
ferrimagnet with correlated and spin-orbit coupled Re t2g electrons moving in
the background of Fe moments stabilized by Hund's coupling. We show that for
such 3d/5d double perovskites, strong correlations on the 5d-element (Re) are
essential in driving a half-metallic ground state. Incorporating both strong
spin-orbit coupling and the Hubbard repulsion on Re leads to a band structure
consistent with ab initio calculations. Using our model, we find a large spin
polarization at the Fermi level, and obtain a semi-quantitative understanding
of the saturation magnetization of Ba2FeReO6, as well as X-ray magnetic
circular dichroism data indicating a significant orbital magnetization. Based
on the orbital populations obtained in our theory, we predict a specific doping
dependence to the tetragonal distortion accompanying ferrimagnetic order.
Finally, the combination of a net magnetization and spin-orbit interactions is
shown to induce Weyl nodes in the band structure, and we predict a significant
intrinsic anomalous Hall effect in hole-doped Ba2FeReO6. The uncovered
interplay of strong correlations and spin-orbit coupling lends partial support
to our previous work, which used a local moment description to capture the spin
wave dispersion found in neutron scattering measurements. Our work is of broad
interest for understanding metallic 4d-based and 5d-based double perovskites
which are of fundamental interest and of possible relevance to spintronic
applications.",1308.3701v2
2017-04-25,A variety of elastic anomalies in orbital-active nearly-itinerant cobalt vanadate spinel,"We perform ultrasound velocity measurements on a single crystal of
nearly-metallic spinel Co$_{1.21}$V$_{1.79}$O$_4$ which exhibits a
ferrimagnetic phase transition at $T_C \sim$ 165 K. The experiments reveal a
variety of elastic anomalies in not only the paramagnetic phase above $T_C$ but
also the ferrimagnetic phase below $T_C$, which should be driven by the
nearly-itinerant character of the orbitally-degenerate V 3$d$ electrons. In the
paramagnetic phase above $T_C$, the elastic moduli exhibit
elastic-mode-dependent unusual temperature variations, suggesting the existence
of a dynamic spin-cluster state. Furthermore, above $T_C$, the sensitive
magnetic-field response of the elastic moduli suggests that, with the negative
magnetoresistance, the magnetic-field-enhanced nearly-itinerant character of
the V 3$d$ electrons emerges from the spin-cluster state. This should be
triggered by the inter-V-site interactions acting on the orbitally-degenerate
3$d$ electrons. In the ferrimagnetic phase below $T_C$, the elastic moduli
exhibit distinct anomalies at $T_1\sim$ 95 K and $T_2\sim$ 50 K, with a sign
change of the magnetoresistance at $T_1$ (positive below $T_1$) and an
enhancement of the positive magnetoresistance below $T_2$, respectively. These
observations below $T_C$ suggest the successive occurrence of an orbital glassy
order at $T_1$ and a structural phase transition at $T_2$, where the rather
localized character of the V 3$d$ electrons evolves below $T_1$ and is further
enhanced below $T_2$.",1704.07537v2
2012-01-17,Weak ferrimagnetism and multiple magnetization reversal in α-Cr3(PO4)2,"The chromium(II) orthophosphate {\alpha}-Cr3(PO4)2 is a weak ferrimagnet with
the Curie temperature TC = 29 K confirmed by a \lambda-type peak in specific
heat. Dominant antiferromagnetic interactions in this system are characterized
by the Weiss temperature {\Theta} = - 96 K, indicating an intermediate
frustration ratio |{\Theta}|/TC ~ 3. In its magnetically ordered states
{\alpha}-Cr3(PO4)2 exhibits a remarkable sequence of temperature-induced
magnetization reversals sensitive to the protocol of measurements, i.e. either
field-cooled or zero-field-cooled regimes. The reduction of the effective
magnetic moment 4.5 {\mu}B/Cr2+, as compared to the spin-only moment 4.9
{\mu}B/Cr2+, cannot be ascribed to the occurence of the low-spin state in any
crystallographic site of the Jahn-Teller active 3d4 Cr2+ ions. X-ray absorption
spectra at the K-edge indicate divalent chromium and unravel the high-spin
state of these ions at the L2,3-edges. Weak ferrimagnetism and multiple
magnetization reversal phenomena seen in this compound could be ascribed to
incomplete cancellation and distortion of partial spontaneous magnetization
functions of Cr2+ in its six crystallographically inequivalent positions.",1201.3465v1
2019-07-01,Robust Formation of Ultrasmall Room-Temperature Neél Skyrmions in Amorphous Ferrimagnets from Atomistic Simulations,"Ne\'el skyrmions originate from interfacial Dzyaloshinskii Moriya interaction
(DMI). Recent studies have explored using thin-film ferromagnets and
ferrimagnets to host Ne\'el skyrmions for spintronic applications. However, it
is unclear if ultrasmall (10 nm or less) skyrmions can ever be stabilized at
room temperature for practical use in high density parallel racetrack memories.
While thicker films can improve stability, DMI decays rapidly away from the
interface. As such, spins far away from the interface would experience
near-zero DMI, raising question on whether or not unrealistically large DMI is
needed to stabilize skyrmions, and whether skyrmions will also collapse away
from the interface. To address these questions, we have employed atomistic
stochastic Landau-Lifshitz-Gilbert simulations to investigate skyrmions in
amorphous ferrimagnetic GdCo. It is revealed that a significant reduction in
DMI below that of Pt is sufficient to stabilize ultrasmall skyrmions even in
films as thick as 15 nm. Moreover, skyrmions are found to retain a uniform
columnar shape across the film thickness despite the decaying DMI. Our results
show that increasing thickness and reducing DMI in GdCo can further reduce the
size of skyrmions at room temperature, which is crucial to improve the density
and energy efficiency in skyrmion based devices.",1907.00647v1
2020-01-08,Non-equilibrium spin dynamics in the temperature and magnetic field dependence of magnetization curves of ferrimagnetic Co$_{1.75}$Fe$_{1.25}$O$_4$ and its composite with BaTiO$_3$,"A comparative study of the non-equilibrium magnetic phenomena (magnetic
blocking, memory, exchange bias and aging effect) has been presented for
ferrimagnetic Co$_{1.75}$Fe$_{1.25}$O$_4$ (CFO) and its composite with
non-magnetic BaTiO$_3$ (BTO). Synchrotron X-Ray diffraction patterns have
confirmed coexistence of CFO and BTO structures in composite, but magnetic spin
dynamics have been remarkably modified. The blocking phenomenon of
ferrimagnetic domains below the room temperature has been studied by different
modes of (zero field cooled and field cooled) magnetic measurements in
collaboration with magnetic fields ON and OFF modes and time dependent
magnetization. The applications of unconventional protocols during time
dependent magnetization measurement at different stages of the temperature and
field dependence of the magnetization curves have been useful to reveal the
non-equilibrium dynamics of magnetic spin order. The applying of off-field
relaxation experiments has made possible to tune the magnetic state and
coercivity of the systems. The role of interfacial coupling between magnetic
and non-magnetic particles has been understood on different magnetic phenomena
(meta-stable magnetic state, exchange bias and memory effect) by comparing the
experimental results of Co$_{1.75}$Fe$_{1.25}$O$_4$ spinel oxide and its
composite with BaTiO$_3$ particles.",2001.02602v2
2020-04-22,Magnetic correlations in polycrystalline $\mathrm{Tb_{0.15}Co_{0.85}}$,"We investigated a polycrystalline sample of the ferrimagnetic compound
$\mathrm{Tb_{0.15}Co_{0.85}}$ by magnetometry and small-angle neutron
scattering (SANS). The magnetization curve at 300 K is characteristic for soft
ferrimagnets but at 5 K the hysteresis indicates the existence of magnetic
domains. The magnetic SANS signal suggests that at 300 K the Tb and Co moments
are correlated over large volumes within the micrometer-sized grains with
correlation lengths > 100 nm. At 5 K, however, the magnetic SANS analysis
reveals a reduced correlation length of around 4.5 nm, which indicates the
formation of narrow magnetic domains within the ferrimagnet with one dimension
being in the nm range. We attribute the observed changes of the domain
structure to the temperature-dependence of the magnetic properties of the Tb
sublattice.",2004.10475v2
2020-12-29,Spin-polarized imaging of strongly interacting fermions in the ferrimagnetic state of Weyl candidate CeBi,"CeBi has an intricate magnetic phase diagram whose fully-polarized state has
recently been suggested as a Weyl semimetal, though the role of $f$ states in
promoting strong interactions has remained elusive. Here we focus on the
less-studied, but also time-reversal symmetry-breaking ferrimagnetic phase of
CeBi, where our density functional theory (DFT) calculations predict additional
Weyl nodes near the Fermi level $E_\mathrm{F}$. We use spin-polarized scanning
tunneling microscopy and spectroscopy to image the surface ferrimagnetic order
on the itinerant Bi $p$ states, indicating their orbital hybridization with
localized Ce $f$ states. We observe suppression of this spin-polarized
signature at $E_\mathrm{F}$, coincident with a Fano line shape in the
conductance spectra, suggesting the Bi $p$ states partially Kondo screen the
$f$ magnetic moments, and this $p-f$ hybridization causes strong Fermi-level
band renormalization. The $p$ band flattening is supported by our quasiparticle
interference (QPI) measurements, which also show band splitting in agreement
with DFT, painting a consistent picture of a strongly interacting magnetic Weyl
semimetal.",2012.14911v2
2021-01-15,Tunable spin-flop transition in artificial ferrimagnets,"Spin-flop transition (SFT) consists in a jump-like reversal of
antiferromagnetic magnetic moments into a non-collinear state when the magnetic
field increases above the critical value. Potentially the SFT can be utilized
in many applications of a rapidly developing antiferromagnetic spintronics.
However, the difficulty of using them in conventional antiferromagnets lies in
(a) too large switching magnetic fields (b) the need for presence of a magnetic
anisotropy, and (c) requirement to apply magnetic field along the correspondent
anisotropy axis. In this work we propose to use artificial ferrimagnets in
which the spin-flop transition occurs without anisotropy and the transition
field can be lowered by adjusting exchange coupling in the structure. This is
proved by experiment on artificial Fe-Gd ferrimagnets where usage of Pd spacers
allowed us to suppress the transition field by two orders of magnitude.",2101.06155v2
2017-05-18,Magnetic vortex nucleation/annihilation in artificial-ferrimagnet microdisks,"The topological nature of magnetic-vortex state gives rise to peculiar
magnetization reversal observed in magnetic microdisks. Interestingly,
magnetostatic and exchange energies which drive this reversal can be
effectively controlled in artificial ferrimagnet heterostructures composed of
rare-earth and transition metals. 25x[Py(t)/Gd(t)] (t=1 or 2 nm) superlattices
demonstrate a pronounced change of the magnetization and exchange stiffness in
a 10-300 K temperature range as well as very small magnetic anisotropy. Due to
these properties, the magnetization of cylindrical microdisks composed of these
artificial ferrimagnets can be transformed from the vortex to
uniformly-magnetized states in a permanent magnetic field by changing the
temperature. We explored the behavior of magnetization in 1.5-micrometer
25x[Py(t)/Gd(t)] (t=1 or 2 nm) disks at different temperatures and magnetic
fields and observed that due to the energy barrier separating vortex and
uniformly-magnetized states, the vortex nucleation and annihilation occur at
different temperatures. This causes the temperature dependences of the Py/Gd
disks magnetization to demonstrate unique hysteretic behavior in a narrow
temperature range. It was discovered that for the 25x[Py(2 nm)/Gd(2 nm)]
microdisks the vortex can be metastable at a certain temperature range.",1705.06398v1
2017-11-29,Thermal contribution to the spin-orbit torque in metallic/ferrimagnetic systems,"We report a systematic study of current-induced perpendicular magnetization
switching in W/Co$_{x}$Tb$_{1-x}$/Al thin films with strong perpendicular
magnetic anisotropy. Various Co$_{x}$Tb$_{1-x}$ ferrimagnetic alloys with
different magnetic compensation temperatures are presented. The systems are
characterized using MOKE, SQUID and anomalous Hall resistance at different
cryostat temperature ranging from 10 K to 350 K. The current-switching
experiments are performed in the spin-orbit torque geometry where the current
pulses are injected in plane and the magnetization reversal is detected by
measuring the Hall resistance. The full reversal magnetization has been
observed in all samples. Some experimental results could only be explained by
the strong sample heating effect during the current pulses injection. We have
found that, for a given composition $x$ and switching polarity, the devices
always reach the same temperature $\textit{T}_{switch}(x)$ before switching
independently of the cryostat temperature. $\textit{T}_{switch}$ seems to scale
with the Curie temperature of the Co$_{x}$Tb$_{1-x}$ ferrimagnetic alloys. This
explains the evolution of the critical current (and critical current density)
as a function of the alloy concentration. Future application could take
advantages of this heating effect which allows reducing the in-plane external
field. Unexpected double magnetization switching has been observed when the
heat generated by the current allows crosses the compensation temperature.",1711.10790v1
2018-08-28,Magnetic field - temperature phase diagram of ferrimagnetic alternating chains: spin-wave theory from a fully polarized vacuum,"Quantum critical (QC) phenomena can be accessed by studying quantum magnets
under an applied magnetic field ($B$). The QC points are located at the
endpoints of magnetization plateaus and separate gapped and gapless phases. In
one dimension, the low-energy excitations of the gapless phase form a Luttinger
liquid (LL), and crossover lines bound insulating (plateau) and LL regimes, as
well as the QC regime. Alternating ferrimagnetic chains have a spontaneous
magnetization at $T=0$ and gapped excitations at zero field. Besides the
plateau at the fully polarized (FP) magnetization; due to the gap, there is
another magnetization plateau at the ferrimagnetic (FRI) magnetization. We
develop spin-wave theories to study the thermal properties of these chains
under an applied magnetic field: one from the FRI classical state, and other
from the FP state, comparing their results with quantum Monte Carlo data. We
deepen the theory from the FP state, obtaining the crossover lines in the $T$
vs. $B$ low-$T$ phase diagram. In particular, from local extreme points in the
susceptibility and magnetization curves, we identify the crossover between an
LL regime formed by excitations from the FRI state to another built from
excitations of the FP state. These two LL regimes are bounded by an asymmetric
dome-like crossover line, as observed in the phase diagram of other quantum
magnets under an applied magnetic field.",1808.09240v1
2019-03-25,Octahedral tilting and emergence of ferrimagnetism in cobalt-ruthenium based double perovskites,"Rare earth based cobalt-ruthenium double perovskites A$_2$CoRuO$_6$ (A = La,
Pr, Nd and Sm) were synthesized and investigated for their structural and
magnetic properties. All the compounds crystallize in the monoclinic $P2_1/n$
structure with the indication of antisite disorder between Co and Ru sites.
While, La compound is already reported to have an antiferromagnetic state below
27 K, the Pr, Nd and Sm systems are found to be ferrimagnetic below $T_c$ = 46,
55 and 78 K respectively. Field dependent magnetization data indicate prominent
hysteresis loop below $T_c$ in the samples containing magnetic rare-earth ions,
however magnetization does not saturate even at the highest applied fields. Our
structural analysis indicates strong distortion in the Co-O-Ru bond angle, as
La$^{3+}$ is replaced by smaller rare-earth ions such as Pr$^{3+}$, Nd$^{3+}$
and Sm$^{3+}$. The observed ferrimagnetism is possibly associated with the
enhanced antiferromagnetic superexchange interaction in the Co-O-Ru pathway due
to bond bending. The Pr, Nd and Sm samples also show small magnetocaloric
effect with Nd sample showing highest value of magnitude $\sim$ 3
Jkg$^{-1}$K$^{-1}$ at 50 kOe. The change in entropy below 20 K is found to be
positive in the Sm sample as compared to the negative value in the Nd
counterpart.",1903.10271v1
2019-03-27,Investigation of Room Temperature Ferroelectricity and Ferrimagnetism in Multiferroic AlxFe2-xO3 Epitaxial Thin Films,"Multiferroic materials open up the possibility to design novel functionality
in electronic devices, with low energy consumption. However, there are very few
materials that show multiferroicity at room temperature, which is essential to
be practically useful. AlxFe2-xO3 (x-AFO) thin films, belonging to the k-Al2O3
family are interesting because they show room temperature ferrimagnetism and
have a polar crystal structure. However, it is difficult to realise its
ferroelectric properties at room temperature, due to low resistivity of the
films. In this work, we have deposited x-AFO (0.5 <= x <= 1) epitaxial thin
films with low leakage, on SrTiO3<111> substrates by Pulsed Laser Deposition.
Magnetic measurements confirmed room temperature ferrimagnetism of the films,
however the Curie temperature was found to be influenced by deposition
conditions. First principle calculations suggested that ferroelectric domain
switching occurs through shearing of in-plane oxygen layers, and predicted a
high polarization value of 24 uC/cm2. However, actual ferroelectric
measurements showed the polarization to be two order less. Presence of multiple
in-plane domains which oppose polarization switching of adjacent domains, was
found to be the cause for the small observed polarization. Comparing dielectric
relaxation studies and ferroelectric characterization showed that
oxygen-vacancy defects assist domain wall motion, which in turn facilitates
polarization switching.",1903.11422v1
2019-08-20,"Peculiarities in pseudo-transitions of a mixed spin-$(1/2,1)$ Ising-Heisenberg double-tetrahedral chain in an external magnetic field","Recently, it has been rigorously verified that several one-dimensional (1D)
spin models may exhibit a peculiar pseudo-transition accompanied with anomalous
response of thermodynamic quantities in a close vicinity of pseudo-critical
temperature. In the present work we will introduce and exactly solve a mixed
spin-(1/2,1) Ising-Heisenberg double-tetrahedral chain in an external magnetic
field as another particular example of 1D lattice-statistical model with
short-range interactions that displays a pseudo-transition of this type. The
investigated model exhibits at zero temperature three ferrimagnetic phases,
three frustrated phases, and one saturated paramagnetic phase. The ground-state
phase diagram involves five unusual interfaces (phase boundaries), at which the
residual entropy per site equals to a larger entropy of one of two coexisting
phases. Four such interfaces are between a non-degenerate ferrimagnetic phase
and a macroscopically degenerate frustrated phase, while one interface is
between two non-degenerate ferrimagnetic phases. Though thermal excitations
typically destroy all fingerprints of zero-temperature phase transitions of 1D
lattice-statistical models with short-range forces, the mixed spin-(1/2,1)
Ising-Heisenberg double-tetrahedral chain is quite robust with respect to
thermal excitations and it displays peculiar pseudo-transitions close to all
five aforementioned interfaces.",1908.07286v2
2019-11-13,Variety of order-by-disorder phases in the asymmetric $J_1-J_2$ zigzag ladder: From the delta chain to the $J_1-J_2$ chain,"We study an asymmetric $J_1$-$J_2$ zigzag ladder consisting of two different
spin-$\frac{1}{2}$ antiferromagnetic (AFM; $J_2$, $\gamma J_2>0$) Heisenberg
legs coupled by zigzag-shaped ferromagnetic (FM; $J_1<0$) inter-leg
interaction. On the basis of density-matrix renormalization group based
calculations the ground-state phase diagram is obtained as functions of
$\gamma$ and $J_2/|J_1|$. It contains four kinds of frustration-induced ordered
phases except a trivial FM phase. Two of the ordered phases are valence bond
solid (VBS) with spin-singlet dimerization, which is a rather conventional
order by disorder. Still, it is interesting to note that the VBS states possess
an Affleck-Kennedy-Lieb-Tasaki-type topological hidden order. The remaining two
phases are ferrimagnetic orders, each of which is distinguished by commensurate
or incommensurate spin-spin correlation. It is striking that the ferrimagnetic
orders are not associated with geometrical symmetry breaking; instead, the
global spin-rotation symmetry is broken. In other words, the system lowers its
energy via the FM inter-leg interaction by polarizing both of the AFM
Heisenberg legs. This is a rare type of order by disorder. Besides, the
incommensurate ferrimagnetic state appears as a consequence of the competition
between a polarization and a critical Tomonaga-Luttinger-liquid behavior in the
AFM Heisenberg legs.",1911.05270v3
2020-03-10,Room-temperature ferrimagnetism of anti-site-disordered Ca2MnOsO6,"Room-temperature ferrimagnetism was discovered for the anti-site-disordered
perovskite Ca2MnOsO6 with Tc = 305 K. Ca2MnOsO6 crystallizes into an
orthorhombic structure with a space group of Pnma, in which Mn and Os share the
oxygen-coordinated-octahedral site at an equal ratio without a noticeable
ordered arrangement. The material is electrically semiconducting with
variable-range-hopping behavior. X-ray absorption spectroscopy confirmed the
trivalent state of the Mn and the pentavalent state of the Os. X-ray magnetic
circular dichroism spectroscopy reveals that the Mn and Os magnetic moments are
aligned antiferromagnetically, thereby classifying the material as a
ferrimagnet which is in accordance with band structure calculations. It is
intriguing that the magnetic signal of the Os is very weak, and that the
observed total magnetic moment is primarily due to the Mn. The Tc = 305 K is
the second highest in the material category of so-called disordered
ferromagnets such as CaRu1-xMnxO3, SrRu1-xCrxO3, and CaIr1-xMnxO3, and hence,
may support the development of spintronic oxides with relaxed requirements
concerning the anti-site disorder of the magnetic ions.",2003.04608v1
2020-03-17,Electrical generation and detection of terahertz signal based on spin-wave emission from ferrimagnets,"Terahertz (THz) signals, mainly generated by photonic or electronic
approaches, are being sought for various applications, whereas the development
of magnetic source might be a necessary step to harness the magnetic nature of
electromagnetic radiation. We show that the relativistic effect on the
current-driven domain-wall motion induces THz spin-wave emission in
ferrimagnets. The required current density increases dramatically in materials
with strong exchange interaction and rapidly exceeds 1012 A m-2, leading to the
device breakdown and thus the lack of experimental evidence. By translating the
collective magnetization oscillations into voltage signals, we propose a
three-terminal device for the electrical detection of THz spin wave. Through
material engineering, wide frequency range from 264 GHz to 1.1 THz and uniform
continuous signals with improved output power can be obtained. As a reverse
effect, the spin wave generated in this system is able to move ferrimagnetic
domain wall. Our work provides guidelines for the experimental verification of
THz spin wave, and could stimulate the design of THz spintronic oscillators for
wideband applications as well as the all-magnon spintronic devices.",2003.07750v1
2020-06-22,Insights into nature of a magnetization plateau of 3$d$-4$f$ coordination polymer [Dy$_2$Cu$_2$]$_n$ from a spin-1/2 Ising-Heisenberg orthogonal-dimer chain,"The ground state and magnetization process of an exactly solved spin-$1/2$
Ising-Heisenberg orthogonal-dimer chain with two different gyromagnetic factors
of the Ising and Heisenberg spins are investigated in detail. It is shown that
the investigated quantum spin chain exhibits up to seven possible ground states
depending on a mutual interplay of the magnetic field, intra- and inter-dimer
coupling constants. More specifically, the frustrated and modulated quantum
antiferromagnetic phases are responsible in zero-temperature magnetization
curves for a zero magnetization plateau. The intermediate 1/11- and
5/11-plateaus emerge due to the frustrated and modulated quantum ferrimagnetic
phases, while the intermediate 9/11- and 10/11-plateaus can be attributed to
the quantum and classical ferrimagnetic phases. It is conjectured that the
magnetization plateau experimentally observed in a high-field magnetization
curve of 3$d$-4$f$ heterobimetallic coordination polymer
[\{Dy(hfac)$_2$(CH$_3$OH)\}$_2$\{Cu(dmg)(Hdmg)\}$_2$]$_n$ (H$_2$dmg $=$
dimethylglyoxime; Hhfac $=$ 1,1,1,5,5,5-hexafluoropentane-2,4-dione) could be
attributed to the classical and quantum ferrimagnetic phases.",2006.12553v3
2020-09-21,Unusual effects of magnetic dilution in the ferrimagnetic columnar ordered $\mathrm{Sm_2MnMnMn_{4-x}Ti_xO_{12}}$ perovskites,"Powder neutron diffraction experiments have been employed to establish the
effects of site-selective magnetic dilution in the Sm2MnMnMn4-x Tix O12 A-site
columnar ordered quadruple perovskite manganites (x = 1, x = 2 and x = 3). We
show that in all three compositions the Mn ions adopt a collinear ferrimagnetic
structure below 27 K, 62 K and 34 K, respectively. An unexpected increase in
the ordering temperature was observed between the x = 1 and x = 2 samples,
which indicates a considerable departure from mean field behaviour. This result
is corroborated by large reductions in the theoretical ground state magnetic
moments observed across the series, which indicate the presence of spin
fluctuations and or disorder. We show that long range magnetic order in the x =
3 sample, which occurs below the percolation threshold for B-B exchange, can
only be understood to arise if magnetic order in Sm2MnMnMn4-xTixO12 is mediated
via both A-B and B-B exchange, hence confirming the importance of A-B exchange
interactions in these materials. Finally we show that site-selective magnetic
dilution enables the tuning of a ferrimagnetic compensation point and the
introduction of temperature-induced magnetization reversal.",2009.10005v1
2020-09-21,Magneto-Elastic Coupling to Coherent Acoustic Phonon Modes in Ferrimagnetic Insulator GdTiO$_3$,"In this work we investigate single crystal GdTiO$_{3}$, a promising candidate
material for Floquet engineering and magnetic control, using ultrafast optical
pump-probe reflectivity and magneto-optical Kerr spectroscopy. GdTiO${}_{3}$ is
a Mott-Hubbard insulator with a ferrimagnetic and orbitally ordered ground
state (\textit{T${}_{C}$} = 32 K). We observe multiple signatures of the
magnetic phase transition in the photoinduced reflectivity signal, in response
to above band-gap 660 nm excitation. Magnetic dynamics measured via Kerr
spectroscopy reveal optical perturbation of the ferrimagnetic order on
spin-lattice coupling timescales, highlighting the competition between the
Gd${}^{3+}$ and Ti${}^{3+}$ magnetic sub-lattices. Furthermore, a strong
coherent oscillation is present in the reflection and Kerr dynamics,
attributable to an acoustic strain wave launched by the pump pulse. The
amplitude of this acoustic mode is highly dependent on the magnetic order of
the system, growing sharply in magnitude at \textit{T${}_{C}$}, indicative of
strong magneto-elastic coupling. The driving mechanism, involving
strain-induced modification of the magnetic exchange interaction, implies an
indirect method of coupling light to the magnetic degrees of freedom and
emphasizes the potential of GdTiO${}_{3}$ as a tunable quantum material.",2009.10222v1
2021-02-26,Direct imaging of chiral domain walls and Néel-type skyrmionium in ferrimagnetic alloys,"The evolution of chiral spin structures is studied in ferrimagnet
Ta/Ir/Fe/GdFeCo/Pt multilayers as a function of temperature using scanning
electron microscopy with polarization analysis (SEMPA). The GdFeCo ferrimagnet
exhibits pure right-hand N\'eel-type domain wall (DW) spin textures over a
large temperature range. This indicates the presence of a negative
Dzyaloshinskii-Moriya interaction (DMI) that can originate from both the top
Fe/Pt and the Co/Pt interfaces. From measurements of the DW width, as well as
complementary magnetic characterization, the exchange stiffness as a function
of temperature is ascertained. The exchange stiffness is surprisingly mostly
constant, which is explained by theoretical predictions. Beyond single
skyrmions, we find by direct imaging a pure N\'eel-type skyrmionium, which due
to the absence of a skyrmion Hall angle is a promising topological spin
structure to enable high impact potential applications in the next generation
of spintronic devices.",2102.13502v2
2021-12-19,Pressure-induced charge orders and their coupling to magnetism in hexagonal multiferroic LuFe2O4,"Hexagonal LuFe2O4 is a promising charge-order (CO) driven multiferroic
material with high charge and spin ordering temperatures. The coexisting charge
and spin orders on Fe3+/Fe2+ sites result in novel magnetoelectric behaviors,
but the coupling mechanism between the charge and spin orders remains elusive.
Here, by tuning external pressure, we reveal three correlated spin-charge
ordered phases in LuFe2O4: i) a centrosymmetric incommensurate
three-dimensional CO with ferrimagnetism, ii) a non-centrosymmetric
incommensurate quasi-two-dimensional CO with ferrimagnetism, and iii) a
centrosymmetric commensurate CO with antiferromagnetism. Experimental in-situ
single-crystal X-ray diffraction and X-ray magnetic circular dichroism
measurements combined with density functional theory calculations suggest that
the charge density redistribution caused by pressure-induced compression in the
frustrated double-layer [Fe2O4] cluster is responsible for the correlated
spin-charge phase transitions. The pressure-enhanced effective Coulomb
interactions among Fe-Fe bonds drive the frustrated (1/3, 1/3) CO to a less
frustrated (1/4, 1/4) CO, which induces the ferrimagnetic to antiferromagnetic
transition. Our results not only elucidate the coupling mechanism among charge,
spin and lattice degrees of freedom in LuFe2O4 but also provide a new way to
tune the spin-charge orders in a highly controlled manner.",2112.10036v1
2022-02-06,Enhancing Perpendicular Magnetic Anisotropy in Garnet Ferrimagnet by Interfacing with Few-Layer WTe2,"Engineering magnetic anisotropy in a ferro- or ferrimagnetic (FM) thin film
is crucial in spintronic device. One way to modify the magnetic anisotropy is
through the surface of the FM thin film. Here, we report the emergence of a
perpendicular magnetic anisotropy (PMA) induced by interfacial interactions in
a heterostructure comprised of a garnet ferrimagnet, Y3Fe5O12 (YIG), and the
low-symmetry, high spin orbit coupling (SOC) transition metal dichalcogenide,
WTe2. At the same time, we also observed an enhancement in Gilbert damping in
the WTe2 covered YIG area. Both the magnitude of interface-induced PMA and the
Gilbert damping enhancement have no observable WTe2 thickness dependence down
to single quadruple-layer, indicating that the interfacial interaction plays a
critical role. The ability of WTe2 to enhance the PMA in FM thin film, combined
with its previously reported capability to generate out-of-plane damping like
spin torque, makes it desirable for magnetic memory applications.",2202.02834v1
2022-05-27,Magnonic Casimir Effect in Ferrimagnets,"Quantum fluctuations are the key concepts of quantum mechanics. Quantum
fluctuations of quantum fields induce a zero-point energy shift under spatial
boundary conditions. This quantum phenomenon, called the Casimir effect, has
been attracting much attention beyond the hierarchy of energy scales, ranging
from elementary particle physics to condensed matter physics together with
photonics. However, the application of the Casimir effect to spintronics has
not yet been investigated enough, particularly to ferrimagnetic thin films,
although yttrium iron garnet (YIG) is one of the best platforms for
spintronics. Here we fill this gap. Using the lattice field theory, we
investigate the Casimir effect induced by quantum fields for magnons in
insulating magnets and find that the magnonic Casimir effect can arise not only
in antiferromagnets but also in ferrimagnets including YIG thin films. Our
result suggests that YIG, the key ingredient of magnon-based spintronics, can
serve also as a promising platform for manipulating and utilizing Casimir
effects, called Casimir engineering. Microfabrication technology can control
the thickness of thin films and realize the manipulation of the magnonic
Casimir effect. Thus, we pave the way for magnonic Casimir engineering.",2205.13802v3
2022-05-28,Magnetic collapse in Fe$_3$Se$_4$ under high pressure,"Electronic structure and magnetic properties of Fe$_3$Se$_4$ are calculated
using the density functional approach. Due to the metallic properties, magnetic
moments of the iron atoms in two nonequivalent positions in the unit cell are
different from ionic values for Fe$^{3+}$ and Fe$^{2+}$ and are equal to
$M_1=2.071 \mu_B$ and $M_2=-2.042 \mu_B$, making the system ferrimagnetic. The
total magnetic moment for the unit cell is $2.135 \mu_B$. Under isotropic
compression, the total magnetic moment decreases non-monotonically and
correlates with the non-monotonic dependence of the density of states at the
Fermi level $N(E_F)$. For 7% compression, the magnetic order changes from the
ferrimagnetic to the ferromagnetic. At 14% compression, the magnetic order
disappears and the total magnetic moment becomes zero, leaving the system in a
paramagnetic state. This compression corresponds to the pressure of 114 GPa.
The magnetic ordering changes faster upon application of an isotropic external
pressure due to the sizeable anisotropy of the chemical bondings in
Fe$_3$Se$_4$. The ferrimagnetic and paramagnetic states occur under pressures
of 5.0 and 8.0 GPa, respectively. The system remains in the metallic state for
all values of compression.",2205.14346v2
2022-07-21,First-principles insights into all-optical spin switching in the half-metallic Heusler ferrimagnet Mn$_2$RuGa,"All-optical spin switching (AOS) represents a new frontier in magnetic
storage technology -- spin manipulation without a magnetic field, -- but its
underlying working principle is not well understood. Many AOS ferrimagnets such
as GdFeCo are amorphous and renders the high-level first-principles study
unfeasible. The crystalline half-metallic Heusler Mn$_2$RuGa presents an
opportunity. Here we carry out hitherto the comprehensive density functional
investigation into the material properties of Mn$_2$RuGa, and introduce two
concepts - the spin anchor site and the optical active site - as two pillars
for AOS in ferrimagnets. In Mn$_2$RuGa, Mn$(4a)$ serves as the spin anchor
site, whose band structure is below the Fermi level and has a strong spin
moment, while Mn$(4c)$ is the optical active site whose band crosses the Fermi
level. Our magneto-optical Kerr spectrum and band structure calculation jointly
reveal that the delicate competition between the Ru-$4d$ and Ga-$4p$ states is
responsible for the creation of these two sites. These two sites found here not
only present a unified picture for both Mn$_2$RuGa and GdFeCo, but also open
the door for the future applications. Specifically, we propose a
Mn$_2$Ru$_x$Ga-based magnetic tunnel junction where a single laser pulse can
control magnetoresistance.",2207.10443v1
2022-08-01,Effect of magnetism and phonons on localized carriers in the ferrimagnetic kagome metals GdMn$_6$Sn$_6$ and TbMn$_6$Sn$_6$,"Kagome metals possess peculiar optical spectra consisting of contributions
from free charge carriers in a Drude-type response, localized carriers seen as
a strongly temperature-dependent localization peak, and, in some cases, phonons
displaying strong anomalies. The rare-earth kagome metal series,
$R$Mn$_6$Sn$_6$, provides a marvelous playground to study the electronic
properties of kagome metals in the presence of variable magnetic order. Here,
we report temperature-dependent reflectivity studies on two members of the
$R$Mn$_6$Sn$_6$ family, GdMn$_6$Sn$_6$ (in-plane ferrimagnet) and
TbMn$_6$Sn$_6$ (out-of-plane ferrimagnet), in a broad energy range (50 - 18000
cm$^{-1}$, equivalent to 6.2 meV - 2.23 eV) down to 10 K. At high temperatures,
a phonon mode at approximately 160 cm$^{-1}$ is observed, which becomes
screened out in TbMn$_6$Sn$_6$ below $\sim$ 150 K as the localization peak
linearly passes through the mode. In GdMn$_6$Sn$_6$, the disappearance of the
phonon is accompanied by the onset of saturation of the peak position,
suggesting an unusual interplay between the two features.",2208.00756v2
2022-08-15,"Two-Dimensional Semiconducting Metal Organic Frameworks with Auxetic Effect, Room Temperature Ferrimagnetism, Chiral Ferroelectricity, Bipolar Spin Polarization and Topological Nodal Lines/Points","Two-dimensional (2D) semiconductors integrated with two or more functions are
the cornerstone for constructing multifunctional nanodevices, but remain
largely limited. Here, by tuning the spin state of organic linkers and the
symmetry/topology of crystal lattice, we predict a class of unprecedented
multifunctional semiconductors in 2D Cr(II) five-membered heterocyclic metal
organic frameworks that simultaneously possess auxetic effect, room temperature
ferrimagnetism, chiral ferroe-lectricity, electrically reversible spin
polarization and topological nodal lines/points. Taking 2D Cr(TDZ)$_2$
(TDZ=1.2.5-thiadiazole) as an exemplification, the auxetic effect is produced
by the anti-tetra-chiral lattice structure. The high temperature ferrimagnetism
originates from the strong d-p direct magnetic exchange interaction between Cr
cations and TDZ doublet radical anions. Meanwhile, the
clockwise-counterclockwise alignment of TDZ' dipoles results in unique 2D
chiral ferroelectricity with atomic-scale vortex-antivortex states. 2D
Cr(TDZ)$_2$ is an intrinsic bipolar magnetic semiconductor where half-metallic
conduction with switchable spin-polarization direction can be induced by
applying a gate voltage. Besides, the symmetry of the little group C$_4$ of
lattice structure endows 2D Cr(TDZ)$_2$ with topological nodal lines and a
quadratic nodal point in the Brillouin zone near the Fermi level.",2208.07024v1
2022-09-07,Effects of site dilution on Compensation in Ising Spin-1/2 trilayered triangular Ferrimagnets with non-equivalent planes,"Using Monte Carlo simulations with the Metropolis algorithm, the magnetic and
thermodynamic behaviours of a spin-1/2, trilayered ferrimagnetic system on
triangular monolayers with quenched nonmagnetic impurities are studied. Two
different theoretical atoms, A and B, make up the ABA and AAB types of distinct
configurations. Like atoms (A-A and B-B) interact ferromagnetically, while
unlike atoms (A-B) interact antiferromagnetically. Only the A-layers are
randomly site-diluted with dilution percentages ranging from 5% to 45%. Such
diluted magnetic thin systems exhibit magnetic compensation which depends
sensitively on the concentration of impurities. The phase diagram in the
Hamiltonian parameter space related to the occurrence of magnetic compensation
phenomenon and the effect of site dilution is discussed in detail. Special
attention is given to the mathematical dependencies of compensation temperature
on the concentration of nonmagnetic impurities. Depending upon the
concentration of nonmagnetic impurities, the compensation and critical points
shift with the equilibrium magnetic behaviours changing between distinct
ferrimagnetic behaviours. For each combination of the coupling strengths, with
values of the impurity concentration above a threshold, compensation appears
where previously was absent. Suggested mathematical formulae show how threshold
impurity concentration relies on Hamiltonian parameters.",2209.03189v2
2022-11-09,Magnetization reversal through an antiferromagnetic state,"Magnetization reversal in ferro- and ferrimagnets is a well-known archetype
of non-equilibrium processes, where the volume fractions of the oppositely
magnetized domains vary and perfectly compensate each other at the coercive
magnetic field. Here, we report on a fundamentally new pathway for
magnetization reversal that is mediated by an antiferromagnetic state.
Consequently, an atomic-scale compensation of the magnetization is realized at
the coercive field, instead of the mesoscopic or macroscopic domain
cancellation in canonical reversal processes. We demonstrate this unusual
magnetization reversal on the Zn-doped polar magnet Fe$_2$Mo$_3$O$_8$. Hidden
behind the conventional ferrimagnetic hysteresis loop, the surprising emergence
of the antiferromagnetic phase at the coercive fields is disclosed by a sharp
peak in the field-dependence of the electric polarization. In addition, at the
magnetization reversal our THz spectroscopy studies reveal the reappearance of
the magnon mode that is only present in the pristine antiferromagnetic state.
According to our microscopic calculations, this unusual process is governed by
the dominant intralayer coupling, strong easy-axis anisotropy and spin
fluctuations, which result in a complex interplay between the ferrimagnetic and
antiferromagnetic phases. Such antiferro-state-mediated reversal processes
offer novel concepts for magnetization control, and may also emerge for other
ferroic orders.",2211.05028v1
2023-01-19,Current-driven dynamics and ratchet effect of skyrmion bubbles in a ferrimagnetic insulator,"Magnetic skyrmions are compact chiral spin textures that exhibit a rich
variety of topological phenomena and hold potential for developing high-density
memory devices and novel computing schemes driven by spin currents. Here, we
demonstrate room temperature interfacial stabilization and current-driven
control of skyrmion bubbles in the ferrimagnetic insulator Tm3Fe5O12 (TmIG)
coupled to Pt. We track the current-induced motion of individual skyrmion
bubbles. The ferrimagnetic order of the crystal together with the interplay of
spin-orbit torques and pinning determine the skyrmion dynamics in TmIG and
result in a strong skyrmion Hall effect characterized by a negative deflection
angle and hopping motion. Further, we show that the velocity and depinning
threshold of the skyrmion bubbles can be modified by exchange coupling TmIG to
an in-plane magnetized Y3Fe5O12 layer, which distorts the spin texture of the
skyrmions and leads to a directional-dependent rectification of their dynamics.
This effect, which is equivalent to a magnetic ratchet, is exploited to control
the skyrmion flow in a racetrack-like device.",2301.08183v1
2023-03-08,Spin-valve nature and giant coercivity of a ferrimagnetic spin semimetal Mn$_2$IrGa,"Spin semimetals are amongst the most recently discovered new class of
spintronic materials, which exhibit a band gap in one spin channel and
semimetallic feature in the other, thus facilitating tunable spin transport.
Here, we report Mn$_2$IrGa to be a candidate material for spin semimetal along
with giant coercivity and spin-valve characteristics using a combined
experimental and theoretical study. The alloy crystallizes in an inverse
Heusler structure (without any martensitic transition) with a para- to
ferri-magnetic transition at $T_\mathrm{C} \sim$ 243 K. It shows a giant
coercive field of about 8.5 kOe (at 2 K). The negative temperature coefficient,
relatively low magnitude and weak temperture dependance of electrical
resistivity suggest the semimetallic character of the alloy. This is further
supported by our specific heat measurement. Magnetoresistance (MR) confirms an
irreversible nature (with its magnitude $\sim$1\%) along with a change of sign
across the magnetic transition indicating the potentiality of Mn$_2$IrGa in
magnetic switching applications. In addition, asymmetric nature of MR in the
positive and negative field cycles is indicative of spin-valve characteristics.
Our ab-initio calculations confirm the inverse Heusler structure with
ferrimagnetic ordering to be the lowest energy state, with a saturation
magnetization of 2 $\mu_\mathrm{B}$. $<100>$ is found to be the easy magnetic
axis with considerable magneto-crystalline anisotropy energy. A large positive
Berry flux at/around $\Gamma$ point gives rise to an appreciable anomalous Hall
conductivity ($\sim$-180 S/cm).",2303.04649v2
2023-05-29,"Structural, Optical and Single-domain Magnetic Features of the Noncollinear Ferrimagnetic Nano-spinel Chromites ACr$_2$O$_4$ (A = Ni, Co, and Mn)","Spinel chromites ACr$_2$O$_4$ with inherent magnetic geometrical frustration
usually exhibit a noncollinear ferrimagnetic ground state when A are magnetic
ions, with possibly crystallite-size dependent intriguing magnetic features.
Here, we report single-domain magnetic properties of ACr$_2$O$_4$ (A = Ni, Co,
and Mn) nanocrystals, with an average crystallite size of 18, 15 and 10 nm,
exhibiting an optical energy gap of 2.87, 3.05 and 2.9 eV, respectively. The
temperature dependence of magnetization indicates the main bulk magnetic
transitions with a commonly coexisting spin-glass-like state and finite-size
effects on the noncolinear ferrimagnetic transitions. An anomaly observed at Ts
= 15, 24 and 10 K is attributed to the bulk magnetic transition to a canted
antiferromagnetic state in NiCr$_2$O$_4$ and incommensurate spiral orders in
CoCr$_2$O$_4$ and MnCr$_2$O$_4$ NCs, respectively. A further bulk magnetic
transition to a commensurate spiral order is observed for CoCr$_2$O$_4$ NCs at
a lock-in temperature Tl = 5 K much lower than that reported using bulk
samples, while it is completely suppressed in the MnCr$_2$O$_4$ NCs.
Finite-size effects and single-domain magnetic behaviors indicated by anomalous
temperature-dependences of the coercive field and the hysteresis-loop
squareness, mainly driven by a magnetocrystalline anisotropy, are discussed in
comparison to results reported using bulk counterparts.",2305.17856v1
2023-05-31,Ferrimagnetic Oscillator Magnetometer,"Quantum sensors offer unparalleled precision, accuracy, and sensitivity for a
variety of measurement applications. We report a compact magnetometer based on
a ferrimagnetic sensing element in an oscillator architecture that circumvents
challenges common to other quantum sensing approaches such as limited dynamic
range, limited bandwidth, and dependence on vacuum, cryogenic, or laser
components. The device exhibits a fixed, calibration-free response governed by
the electron gyromagnetic ratio. Exchange narrowing in the ferrimagnetic
material produces sub-MHz transition linewidths despite the high unpaired spin
density ($\sim 10^{22}$ cm$^{-3}$). The magnetometer achieves a minimum
sensitivity of 100 fT/$\sqrt{\text{Hz}}$ to AC magnetic fields of unknown phase
and a sensitivity below 200 fT/$\sqrt{\text{Hz}}$ over a bandwidth $\gtrsim \!
1$ MHz. By encoding magnetic field in frequency rather than amplitude, the
device provides a dynamic range in excess of 1 mT. The passive, thermal
initialization of the sensor's quantum state requires only a magnetic bias
field, greatly reducing power requirements compared to laser-initialized
quantum sensors. With additional development, this device promises to be a
leading candidate for high-performance magnetometry outside the laboratory, and
the oscillator architecture is expected to provide advantages across a wide
range of sensing platforms.",2305.19938v1
2023-08-08,Ionically-Driven Synthesis and Exchange Bias in Mn$_{4}$N/MnN$_{x}$ Heterostructures,"Ferrimagnets have received renewed attention as a promising platform for
spintronic applications. Of particular interest is the Mn4N from the
${\epsilon}$-phase of the manganese nitride as an emergent rare-earth-free
spintronic material due to its perpendicular magnetic anisotropy, small
saturation magnetization, high thermal stability, and large domain wall
velocity. We have achieved high-quality (001)-ordered Mn$_{4}$N thin film by
sputtering Mn onto ${\eta}$-phase Mn$_{3}$N$_{2}$ seed layers on Si substrates.
As the deposited Mn thickness varies, nitrogen ion migration across the
Mn$_{3}$N$_{2}$/Mn layers leads to a continuous evolution of the layers to
Mn$_{3}$N$_{2}$/Mn$_{2}$N/Mn$_{4}$N, Mn$_{2}$N/Mn$_{4}$N, and eventually
Mn$_{4}$N alone. The ferrimagnetic Mn$_{4}$N indeed exhibits perpendicular
magnetic anisotropy, and forms via a nucleation-and-growth mechanism. The
nitrogen ion migration is also manifested in a significant exchange bias, up to
0.3 T at 5 K, due to the interactions between ferrimagnetic Mn$_{4}$N and
antiferromagnetic Mn$_{3}$N$_{2}$ and Mn$_{2}$N. These results demonstrate a
promising all-nitride magneto-ionic platform with remarkable tunability for
device applications.",2308.04274v2
2023-09-25,"Magnetic States and Electronic Properties of Manganese-Based Intermetallic Compounds Mn$_2$YAl and Mn$_3$Z (Y = V, Cr, Fe, Co, Ni; Z = Al, Ge, Sn, Si, Pt)","We present a brief review of experimental and theoretical papers on studies
of electron transport and magnetic properties in manganese-based compounds
Mn$_2$YZ and Mn$_3$Z (Y = V, Cr, Fe, Co, Ni, etc.; Z = Al, Ge, Sn, Si, Pt,
etc.). It has been shown that in the electronic subsystem of Mn$_2$YZ
compounds, the states of a half-metallic ferromagnet and a spin gapless
semiconductor can arise with the realization of various magnetic states, such
as a ferromagnet, a compensated ferrimagnet, and a frustrated antiferromagnet.
Binary compounds Mn$_3$Z have the properties of a half-metallic ferromagnet and
a topological semimetal with a large anomalous Hall effect, spin Hall effect,
spin Nernst effect, and thermal Hall effect. Their magnetic states are also
very diverse: from a ferrimagnet and an antiferromagnet to a compensated
ferrimagnet and a frustrated antiferromagnet, as well as an antiferromagnet
with a kagome-type lattice. It has been demonstrated that the electronic and
magnetic properties of such materials are very sensitive to external influences
(temperature, magnetic field, external pressure), as well as the processing
method (cast, rapidly quenched, nanostructured, etc.). Knowledge of the
regularities in the behavior of the electronic and magnetic characteristics of
Mn$_2$YAl and Mn$_3$Z compounds can be used for applications in micro- and
nanoelectronics and spintronics.",2309.14140v1
2023-12-25,Controllable magnon frequency comb in synthetic ferrimagnets,"Magnon frequency comb provides opportunities for exploring magnon nonlinear
effects and measuring the transmission magnon frequency in magnets, whose
controllability becomes vital for modulating the operating frequency and
improving the measurement accuracy. Nevertheless, such controllable frequency
comb remains to be explored. In this work, we investigate theoretically and
numerically the skyrmion-induced magnon frequency comb effect generated by
interaction between the magnon excitation mode and skyrmion breathing mode in
synthetic ferrimagnets. It is revealed that both the skyrmion breathing mode
and the magnon frequency gap closely depend on the net angular momentum
{\delta}s, emphasizing the pivotal role of {\delta}s as an effective control
parameter in governing the comb teeth. With the increase of {\delta}s, the
skyrmion size decreases, which results in the enlargement of the breathing
frequency and the distance between the comb teeth. Moreover, the dependences of
the magnon frequency gap on {\delta}s and the inter-layer coupling allow one to
modulate the comb lowest coherent frequency via structural control.
Consequently, the coherent modes generated by the comb may range from gigahertz
to terahertz frequencies, serving as a bridge between microwave and terahertz
waves. Thus, this work represents a substantial advance in understanding the
magnon frequency comb effect in ferrimagnets.",2312.15584v2
2003-09-05,Induced Magnetic Ordering by Proton Irradiation in Graphite,"We provide evidence that proton irradiation of energy 2.25 MeV on
highly-oriented pyrolytic graphite samples triggers ferro- or ferrimagnetism.
Measurements performed with a superconducting quantum interferometer device
(SQUID) and magnetic force microscopy (MFM) reveal that the magnetic ordering
is stable at room temperature.",0309128v1
2004-02-11,Unusual giant magnetostriction in the ferrimagnet Gd$_{2/3}$Ca$_{1/3}$MnO$_3$,This paper has been withdrawn by authors.,0402297v4
2004-11-05,Universality Classes of Diagonal Quantum Spin Ladders,"We find the classification of diagonal spin ladders depending on a
characteristic integer $N_p$ in terms of ferrimagnetic, gapped and critical
phases. We use the finite algorithm DMRG, non-linear sigma model and
bosonization techniques to prove our results. We find stoichiometric contents
in cuprate $CuO_2$ planes that allow for the existence of weakly interacting
diagonal ladders.",0411132v1
2006-03-31,Half-metallic diluted antiferromagnetic semiconductors,"The possibility of half-metallic antiferromagnetism, a special case of
ferrimagnetism with a compensated magnetization, in the diluted magnetic
semiconductors is highlighted on the basis of the first principles electronic
structure calculation. As typical examples, the electrical and magnetic
properties of II-VI compound semiconductors doped with 3d transition metal ion
pairs--(V, Co) and (Fe, Cr)--are discussed.",0603846v1
2007-03-22,Nonmagnetic-Defect-Induced Magnetism in Graphene,"It is shown that a strong impurity potential induces short-range
antiferromagnetic (ferrimagnetic) order around itself in a Hubbard model on a
half-filled honeycomb lattice. This implies that short-range magnetic order is
induced in monolayer graphene by a nonmagnetic defect such as a vacancy with
full hydrogen termination or a chemisorption defect.",0703570v2
2009-06-17,Magnetostructural Effect in the Multiferroic BiFeO3-BiMnO3 Checkerboard from First Principles,"Using first principles calculations, we present a magnetostructural effect in
the BiFeO3-BiMnO3 nanocheckerboard that is not found in either bulk parent
compound or in BiFeO3-BiMnO3 superlattices. We also demonstrate that the
atomic-scale checkerboard has a multiferroic ground state with the desired
properties of each constitutent material: polar and ferrimagnetic due to BiFeO3
and BiMnO3 respectively.",0906.3201v1
2012-08-22,Gap Generation in Topological Insulator Surface States by non-Ferromagnetic Magnets,"It is shown that, contrary to the naive expectation, single particle spectral
gaps can be opened on the surface states of three dimensional topological
insulators by using commensurate out- and in-plane antiferromagnetic or
ferrimagnetic insulating thin films.",1208.4615v1
2016-02-28,"Effective field theory and the scattering process for magnons in the ferromagnet, antiferromagnet, and ferrimagnet","We discuss that a low-energy effective Lagrangian relying on SO(3)
$\rightarrow$ SO(2) is applicable for a ferrimagnet as well as a ferromagnet
and an antiferromagnet. The analysis of the particle states shows that there
exist not only massless modes with the dispersion relations $\omega \propto
|\bm{k}|,\, |\bm{k}|^2$, i.e., the so-called type-I and type-II Nambu-Goldstone
modes, respectively, but also gapped modes with $\omega \propto
m^2+|\bm{k}|^2$. We clarify how the coefficients of the terms with one time
derivative and those with two time derivatives in the effective Lagrangian
determine the order parameters specifying whether the system is in a
ferromagnetic, antiferromagnetic or ferrimagnetic state; we stress that the
gapped mode related to the spontaneous symmetry breaking appears only in the
ferrimagnetic system and not in the ferromagnetic and antiferromagnetic
systems. We also establish the power counting scheme and calculate the
scattering amplitudes and thereby the scattering lengths between the two
Nambu-Goldstone bosons. We show that the scattering length of the gapped mode
is finite and proportional to the gap. This characteristic property of the
gapped NG mode can be used to discriminate it from gapped excitations which
originate in other mechanisms. Finally, we study the effects of the explicit
symmetry breaking that are given by an external magnetic field and a single-ion
anisotropy, and show that the external magnetic fields do not have any effects
on the scattering amplitudes in all the spin systems as was known for the
ferromagnet system. In contrast, the anisotropy does affect the scattering
amplitudes, the phase shift, and the scattering length except for spin 1/2
systems. This result supports the possibility of the Efimov effect in spin
systems discussed in previous studies.",1602.08692v2
2019-02-01,Quantum thermodynamics of complex ferrimagnets,"High-quality magnets such as yttrium iron garnet (YIG) are electrically
insulating and very complex. By implementing a quantum thermostat into
atomistic spin dynamics we compute YIG's key thermodynamic properties, viz. the
magnon power spectrum and specific heat, for a large temperature range. The
results differ (sometimes spectacularly) from simple models and classical
statistics, but agree with available experimental data.",1902.00449v1
2020-10-26,Effect of the Uniform Random External Magnetic Field with Spatio-temporal Variation on Compensation in Ising Spin-1/2 Trilayered Square Ferrimagnet,"Trilayered spin-1/2 Ising ferrimagnets are interesting thin systems for
compensation phenomenon. In this work, a Metropolis Monte Carlo study is
performed on the magnetic and thermodynamic response of such a system on square
Bravais lattice, driven by uniform random external magnetic field with
spatio-temporal variations. In two distinct configurations, the surface layers
are made up of A and the mid-layer is made up of B atoms in a ABA type stacking
while in AAB type stacking, the top-layer and the mid-layer is made up of
A-atoms while the bottom layer is made up of B-atoms. The magnetic coupling
between the like atoms (A-A and B-B) is ferromagnetic while between the unlike
atoms (A-B), it is antiferromagnetic. For the time-dependent external uniform
random field, the mean is always set to zero and the standard deviation is
varied until spin-field energy is comparable to the dominant cooperative energy
of the system. The findings show that the observed compensation and critical
points shift and steady-state magnetic behaviours shift between N-, L-, P- and
Q- etc. type of ferrimagnetic behaviours, depending upon the strength of
external uniform random field. The compensation phenomenon even vanishes after
crossing a finite threshold of standard deviation of the magnetic field for
particular choices of the other controlling parameters. Thus islands of
ferrimagnetic phase without compensation appear within the phase area with
compensation of field-free case, in the 2D Hamiltonian parameter space. For
both the configurations, the areas of such islands even grow with increasing
standard deviation of the external field, {\sigma}, obeying a scaling relation
of the form: $f ({\sigma}, A({\sigma})) = {\sigma}^{-b} A({\sigma})$ with
$b_{ABA} = 1.958 \pm 0.122$ and $b_{AAB} = 1.783 \pm 0.118$ .",2010.13643v4
2023-03-01,"Covalency, correlations, and inter-layer interactions governing the magnetic and electronic structure of Mn$_3$Si$_2$Te$_6$","Mn$_3$Si$_2$Te$_6$ is a rare example of a layered ferrimagnet. It has
recently been shown to host a colossal angular magnetoresistance as the spin
orientation is rotated from the in- to out-of-plane direction, proposed to be
underpinned by a topological nodal-line degeneracy in its electronic structure.
Nonetheless, the origins of its ferrimagnetic structure remain controversial,
while its experimental electronic structure, and the role of correlations in
shaping this, are little explored to date. Here, we combine x-ray and
photoemission-based spectroscopies with first-principles calculations, to probe
the elemental-selective electronic structure and magnetic order in
Mn$_3$Si$_2$Te$_6$. Through these, we identify a marked Mn-Te hybridisation,
which weakens the electronic correlations and enhances the magnetic anisotropy.
We demonstrate how this strengthens the magnetic frustration in
Mn$_3$Si$_2$Te$_6$, which is key to stabilising its ferrimagnetic order, and
find a crucial role of both exchange interactions extending beyond
nearest-neighbours and anti-symmetric exchange in dictating its ordering
temperature. Together, our results demonstrate a powerful methodology of using
experimental electronic structure probes to constrain the parameter space for
first-principles calculations of magnetic materials, and through this approach,
reveal a pivotal role played by covalency in stabilising the ferrimagnetic
order in Mn$_3$Si$_2$Te$_6$.",2303.00294v1
1993-12-15,1/z-renormalization of the mean-field behavior of the dipole-coupled singlet-singlet system HoF_3,"The two main characteristics of the holmium ions in HoF_3 are that their
local electronic properties are dominated by two singlet states lying well
below the remaining 4f-levels, and that the classical dipole-coupling is an
order of magnitude larger than any other two-ion interactions between the
Ho-moments. This combination makes the system particularly suitable for testing
refinements of the mean-field theory. There are four Ho-ions per unit cell and
the hyperfine coupled electronic and nuclear moments on the Ho-ions order in a
ferrimagnetic structure at T_C=0.53 K. The corrections to the mean-field
behavior of holmium triflouride, both in the paramagnetic and ferrimagnetic
phase, have been calculated to first order in the high-density 1/z-expansion.
The effective medium theory, which includes the effects of the single-site
fluctuations, leads to a substantially improved description of the magnetic
properties of HoF_3, in comparison with that based on the mean-field
approximation.",9312060v1
1995-12-13,First-principles studies of modulated Co/Cu superlattices with strongly and weakly exchange-biased Co-monolayers leading to a ferrimagnetic ground state,"First-principles calculations have been performed in order to determine
effective exchange integrals between strongly and weakly exchange-biased Co
monolayers in the modulated CoCu$_2$/CoCu$_n$ superlattices. For $3\le n\le 6$
it has been found that the respective exchange integrals have opposite signs
and differ for $n\ne 4$ from each other by one order of magnitude and for $n=4$
still by a factor of $\sim 1.7$. The obtained phase diagram, with all the
relevant magnetic phases, shows that for the $n$-values considered, the ground
state configuration is ferrimagnetic.",9512103v1
1996-11-27,Critical Behaviour of Mixed Heisenberg Chains,"The critical behaviour of anisotropic Heisenberg models with two kinds of
antiferromagnetically exchange-coupled centers are studied numerically by using
finite-size calculations and conformal invariance. These models exhibit the
interesting property of ferrimagnetism instead of antiferromagnetism. Most of
our results are centered in the mixed Heisenberg chain where we have at even
(odd) sites a spin-S (S') SU(2) operator interacting with a XXZ like
interaction (anisotropy $\Delta$). Our results indicate universal properties
for all these chains. The whole phase, $1>\Delta>-1$, where the models change
from ferromagnetic $( \Delta=1 )$ to ferrimagnetic $(\Delta=-1)$ behaviour is
critical. Along this phase the critical fluctuations are ruled by a c=1
conformal field theory of Gaussian type. The conformal dimensions and critical
exponents, along this phase, are calculated by studying these models with
several boundary conditions.",9611227v1
1998-06-02,Kinetics of a mixed Ising ferrimagnetic system,"We present a study, within a mean-field approach, of the kinetics of a
classical mixed Ising ferrimagnetic model on a square lattice, in which the two
interpenetrating square sublattices have spins $\sigma = \pm1/2$ and $S = \pm
1,0$. The kinetics is described by a Glauber-type stochastic dynamics in the
presence of a time-dependent oscillating external field and a crystal field
interaction. We can identify two types of solutions: a symmetric one, where the
total magnetization, $M$, oscillates around zero, and an antisymmetric one
where $M$ oscillates around a finite value different from zero. There are
regions of the phase space where both solutions coexist. The dynamical
transition from one regime to the other can be of first or second order
depending on the region in the phase diagram. Depending on the value of the
crystal field we found up to two dynamical tricritical points where the
transition changes from continuous to discontinuous. Also, we perform a similar
study on the Blume-Capel ($S=\pm 1,0$) model and found strong differences
between its behavior and the one of the mixed model.",9806036v1
1998-12-18,"Spinon signatures in the critical phase of the (1,1/2) ferrimagnet in a magnetic field","We propose an effective theory for the critical phase of a quantum
ferrimagnetic chain with alternating spins 1 and 1/2 in an external magnetic
field. With the help of the matrix product variational approach, the system is
mapped to a spin-1/2 XXZ chain in an (effective) magnetic field; as a
byproduct, we obtain an excellent description of the optical magnon branch in
the gapped phase. Recent finite-temperature DMRG results for the
low-temperature part of the specific heat are well described by the present
approach, and the ``pop-up'' peaks, developing near the critical field values
and in the middle of the critical phase, are identified with the contributions
from two different spinon bands of the effective spin-1/2 chain. The effect
should be as well observable in other spin-gap systems in an external field,
particularly in spin ladders.",9812326v1
1999-04-08,Properties of the ferrimagnetic double-perovskite A_{2}FeReO_{6} (A=Ba and Ca),"Ceramics of A_{2}FeReO_{6} double-perovskite have been prepared and studied
for A=Ba and Ca. Ba_{2}FeReO_{6} has a cubic structure (Fm3m) with $a\approx
$8.0854(1) \AA whereas Ca_{2}FeReO_{6} has a distorted monoclinic symmetry with
$a\approx 5.396(1) \AA, b\approx 5.522(1) \AA, c\approx 7.688(2) \AA$ and
$\beta =90.4^{\circ} (P21/n)$. The barium compound is metallic from 5 K to 385
K, i.e. no metal-insulator transition has been seen up to 385 K, and the
calcium compound is semiconducting from 5 K to 385 K. Magnetization
measurements show a ferrimagnetic behavior for both materials, with T_{c}=315 K
for Ba_{2}FeReO_{6} and above 385 K for Ca_{2}FeReO_{6}. A specific heat
measurement on the barium compound gave an electron density of states at the
Fermi level, N(E_{F}) equal to 6.1$\times 10^{24} eV^{-1}mole^{-1}$. At 5 K, we
observed a negative magnetoresistance of 10 % in a magnetic field of 5 T, but
only for Ba_{2}FeReO_{6}. Electrical, thermal and magnetic properties are
discussed and compared to the analogous compounds Sr_{2}Fe(Mo,Re)O_{6}.",9904119v1
1999-05-19,Ground State Property of an Alternating Spin Ladder Involving Two Kinds of Inter-Chain Interactions,"The ground state property of the alternating spin ladder is studied in the
case that the system involves an antiferromagnetic intra-chain interaction as
well as two kinds of inter-chain interactions; one is between spins of the same
magnitude and the other is between spins with different magnitudes. The
calculation has been carried out by the exact diagonalization method. As a
consequence of the competition among interactions, the system is revealed to
show an interesting variety of phases in the ground state property. Its phase
diagram is exhibited in the parameter space of the system. We find that,
however small the total amount of the inter-chain interactions is, the
ferrimagnetic ground state becomes unstable in a certain region. In this case,
which of the ferrimagnetic and the singlet ground state to appear is determined
only by the ratio between the inter-chain interactions regardless of their
total amount. The nature of two phases appearing in the singlet region of the
phase diagram and the type of the phase transition between them are also
discussed. The results are ensured by comparing with those of obtained in other
models which are contained in our model as special limiting cases.",9905269v1
2000-04-14,Superconductivity and Antiferromagnetism: Hybridization Impurities in a Two-Band Spin-Gapped Electron System,"We present the exact solution of a one-dimensional model of a spin-gapped
correlated electron system with hybridization impurities exhibiting both
magnetic and mixed-valence properties. The host supports superconducting
fluctuations, with a spin gap. The localized electrons create a band of
antiferromagnetic spin excitations inside the gap for concentrations x of the
impurities below some critical value x_c. When x = x_c the spin gap closes and
a ferrimagnetic phase appears. This is the first example of an exactly solvable
model with coexisting superconducting and antiferromagnetic fluctuations which
in addition supports a quantum phase transition to a (compensated)
ferrimagnetic phase. We discuss the possible relevance of our results for
experimental systems, in particular the U-based heavy-fermion materials.",0004248v1
2000-11-18,Magneto-electronic Properties of a Ferrimagnetic Semiconductor: The Hybrid Cupromanganite CaCu3Mn4O12,"The mixed manganite-cuprate CaCu3Mn4O12 is found, using density functional
methods, to be a narrow gap (90 meV calculated) ferrimagnetic semiconductor. Cu
(formally S=1/2) antialigns with Mn (formally S=3/2), and the net spin moment
is 9 \mu_B consistent with the formal spins. Holes have Cu d_{xy}-O p_{\sigma}
(i.e. antibonding dp\sigma) character with spins aligned antiparallel to the
net magnetization; electrons have the opposite spin and have mixed Cu d_{xy} -
Mn e_g character. Thermally excited electrons and holes will each be fully spin
polarized, but in opposite directions. The properties of this material are
strongly tied to the distorted quadruple perovskite structure, which is closely
related to the skutterudite structure. The observed resistivity,
magnetoresistance, and magnetization are discussed in terms of our results.",0011316v1
2001-08-31,Inversion Phenomena of the Anisotropies of the Hamiltonian and the Wave-Function in the Distorted Diamond Type Spin Chain,"We investigate the ground-sate phase diagram of the XXZ version of the S=1/2
distorted diamond chain by use of the degenerate perturbation theory near the
truncation point. In case of the XY-like interaction anisotropy, the phase
diagram consists of the Neel phase and the spin-fluid phase. For the Ising-like
interaction anisotropy case, it consists of three phases: the ferrimagnetic
phase, the Neel phase and the spin-fluid phase. The magnetization in the
ferrimagnetic phase is 1/3 of the saturation magnetization. The remarkable
nature of the phase diagram is the existence of the Neel phase, although the
interaction anisotropy is XY-like. And also, the spin-fluid phase appears in
spite of the Ising-like interaction anisotropy. We call these regions
""inversion regions"".",0108528v1
2002-04-17,Quantum magnetization plateaux of an anisotropic ferrimagnetic spin chain,"The magnetization curve of the $(S,s)=(1,1/2)$ ferrimagnetic alternating spin
chain with the single-ion anisotropy $D$ is investigated with the numerical
exact diagonalization of finite clusters and size-scaling analyses. The system
has a plateau at 1/3 of the saturation moment, which corresponds to the
spontaneous magnetization for D=0. Varying $D$ in the 1/3-magnetized ground
state under the external field along the axis of $D$, a quantum phase
transition is revealed to occur at the critical value $D/J=1.114 \pm 0.001$
where the plateau vanishes. Except for the critical point, the plateau is
always opening, but the mechanism is different between $D<D_c$ and $D>D_c$. The
change of mechanisms is an evidence to clarify that the plateau originates from
the quantization of magnetization.",0204375v2
2003-06-26,Nuclear spin-lattice relaxation in ferrimagnetic clusters and chains: A contrast between zero and one dimensions,"Motivated by ferrimagnetic oligonuclear and chain compounds synthesized by
Caneschi et al., both of which consist of alternating manganese(II) ions and
nitronyl-nitroxide radicals, we calculate the nuclear spin-lattice relaxation
rate 1/T_1 employing a recently developed modified spin-wave theory. 1/T_1 as a
function of temperature drastically varies with the location of probe nuclei in
both clusters and chains, though the relaxation time scale is much larger in
zero dimension than in one dimension. 1/T_1 as a function of an applied field
in long chains forms a striking contrast to that in finite clusters, diverging
with decreasing field like inverse square root at low temperatures and
logarithmically at high temperatures.",0306685v1
2005-04-26,"First-principles study of exchange interactions and Curie temperatures of half-metallic ferrimagnetic full Heusler alloys Mn2VZ (Z=Al, Ge)","We report the parameter-free, density functional theory calculations of
interatomic exchange interactions and Curie temperatures of half-metallic
ferrimagnetic full Heusler alloys Mn2VZ (Z=Al, Ge). To calculate the
interatomic exchange interactions we employ the frozen-magnon approach. The
Curie temperatures are calculated within the mean-field approximation to the
classical Heisenberg Hamiltonian by solving a matrix equation for a
multi-sublattice system. Our calculations show that, although a large magnetic
moment is carried by Mn atoms, competing ferromagnetic (inter sublattice) and
antiferromagnetic (intra sublattice) Mn-Mn interactions in Mn2VAl almost cancel
each other in the mean-field experienced by the Mn atoms. In Mn2VGe the leading
Mn-Mn exchange interaction is antiferromagnetic. In both compounds the
ferromagnetism of the Mn subsystem is favored by strong antiferromagnetic Mn-V
interactions. The obtained value of the Curie temperature of Mn2VAl is in good
agrement with experiment. For Mn2VGe there is no experimental information
available and our calculation is a prediction.",0504679v1
2005-09-05,Magnetoelectric Coupling in epsilon-Fe2O3,"Nanoparticles of the ferrimagnetic epsilon-Fe2O3 oxide have been synthesized
by sol-gel method. Here, we report on the measurements of the dielectric
permittivity as a function of temperature, frequency and magnetic field. It is
found that, coinciding with the transition from collinear ferrimagnetic
ordering to an incommensurate magnetic state occurring at about 100 K, there is
an abrupt change (about 30 %) of permittivity suggesting the existence of a
magnetoelectric coupling in this material. Indeed, magnetic field dependent
measurements at 100 K have revealed an increase of the permittivity by about
0.3 % in 6 T. Prospective advantages of epsilon-Fe2O3 as multiferroic material
are discussed.",0509104v1
2005-12-15,Phase Diagram of Lattice-Spin System RbCoBr$_3$,"We study the lattice-spin model of RbCoBr$_3$ which is proposed by Shirahata
and Nakamura, by mean field approximation. This model is an Ising spin system
on a distorted triangular lattice. There are two kinds of frustrated variables,
that is, the lattice and spin. We obtain a phase diagram of which phase
boundary is drawn continuously in a whole region. Intermediate phases that
include a partial disordered state appear. The model has the first-order phase
transitions in addition to the second-order phase transitions. We find a
three-sublattice ferrimagnetic state in the phase diagram. The three-sublattice
ferrimagnetic state does not appear when the lattice is not distorted.",0512332v1
2005-12-24,Fermionic versus bosonic descriptions of one-dimensional spin-gapped antiferromagnets,"In terms of spinless fermions and spin waves, we describe magnetic properties
of a spin-1/2 ferromagnetic-antiferromagnetic bond-alternating chain which
behaves as a Haldane-gap antiferromagnet. On one hand, we employ the
Jordan-Wigner transformation and treat the fermionic Hamiltonian within the
Hartree-Fock approximation. On the other hand, we employ the Holstein-Primakoff
transformation and modify the conventional spin-wave theory so as to restore
the sublattice symmetry. We calculate the excitation gap, the specific heat,
the magnetic susceptibility, magnetization curves, and the nuclear spin-lattice
relaxation rate with varying bond alternation. These schemes are further
applied to a bond-alternating tetramerized chain which behaves as a
ferrimagnet. The fermionic language is particularly stressed as a useful tool
to investigate one-dimensional spin-gapped antiferromagnets, while the bosonic
one works better for ferrimagnets.",0512631v1
2006-03-08,Anomalous impurity effect on magnetization in frustrated one-dimensional ferro- and ferrimagnets,"Significant decrease of spontaneous magnetization in frustrated
one-dimensional ferro- and ferrimagnets due to non-magnetic impurities is
predicted. Using the density-matrix renormalization group method and the exact
diagonalization method, we confirm that the total spin can vanish due to a
single impurity in finite chains. Introducing the picture of magnetic domain
inversion, we numerically investigate the impurity-density dependence of
magnetization. In particular, we show that even with an infinitesimal density
of impurities the magnetization in the ground state is reduced by about 40%
from that of the corresponding pure system. Conditions for the materials which
may show this anomalous impurity effect are formulated.",0603193v1
2006-09-13,Current-induced magnetization switching in MgO barrier based magnetic tunnel junctions with CoFeB/Ru/CoFeB synthetic ferrimagnetic free layer,"We report the intrinsic critical current density (Jc0) in current-induced
magnetization switching and the thermal stability factor (E/kBT, where E, kB,
and T are the energy potential, the Boltzmann constant, and temperature,
respectively) in MgO based magnetic tunnel junctions with a
Co40Fe40B20(2nm)/Ru(0.7-2.4nm)/Co40Fe40B20(2nm) synthetic ferrimagnetic (SyF)
free layer. We show that Jc0 and E/kBT can be determined by analyzing the
average critical current density as a function of coercivity using the
Slonczewski's model taking into account thermal fluctuation. We find that high
antiferromagnetic coupling between the two CoFeB layers in a SyF free layer
results in reduced Jc0 without reducing high E/kBT.",0609306v2
2006-11-24,Magnetic and transport properties of a one dimensional frustrated t-J model for vanadate nanotubes,"We propose a one-dimensional model consisting of a chain with a t-J
Hamiltonian coupled to a Heisenberg chain in a frustrated geometry to describe
the appearance of the ferromagnetic phase which has been experimentally
observed in vanadate nanotubes. This model contains a mechanism of frustration
suppressed by doping suggested by L. Krusin-Elbaum, et al. [Nature 431, 672
(2004)]. We study, using numerical techniques in small clusters, the relation
between magnetic order and transport properties in the proposed model, and we
perform a detailed comparison of the physical properties of this model with
those of the ferromagnetic Kondo lattice model. For this comparison, a number
of results for the latter model, obtained using the same numerical techniques,
will be provided to complement those results already available in the
literature. We conclude that it does not appear to be a true ferromagnetic
order in the proposed model, but rather an incommensurate ferrimagnetic one,
and contrary to what happens in the ferromagnetic Kondo lattice model,
electronic transport is somewhat suppressed by this ferrimagnetic order.",0611603v2
2006-11-30,"Role of the presence of transition-metal atoms at the antisites in CrAs, CrSe and VAs zinc-blende compounds","In a recent publication [Galanakis I et al 2006 \PR B \textbf{74} 140408(R)]
we have shown that in the case of CrAs and related transition-metal
chalcogenides and pnictides, crystallizing in the zinc-blende structure, the
excess of the transition-metal atoms leads to half-metallic ferrimagnetism. The
latter property is crucial for spintronic applications with respect to
ferromagnets due to the lower stray fields created by these materials. We
extend this study to cover the case where the transition-metal atoms sitting at
antisites are not identical to the ones in the perfect sites. In Cr-based
compounds, the creation of Mn antisites keeps the half-metallic ferrimagnetic
character produced also by the Cr antisites. In the case of VAs, Cr and Mn
antisites keep the half-metallic character of VAs (contrary to V antisites) due
to the larger exchange-splitting exhibited by these atoms.",0611777v1
2006-06-04,"Structure, electronic properties and magnetic transition in manganese clusters","We systematically investigate the structural, electronic and magnetic
properties of Mn$_n$ clusters ($n =$ 2$-$20) within the {\it ab-initio}
pseudopotential plane wave method using generalized gradient approximation for
the exchange-correlation energy. A new kind of icosahedral structural growth
has been predicted in the intermediate size range. Calculated magnetic moments
show an excellent agreement with the Stern-Gerlach experiment. A transition
from ferromagnetic to ferrimagnetic Mn$-$Mn coupling takes place at $n=$ 5 and
the ferrimagnetic states continue to be the ground states for the entire size
range. Possible presence of multiple isomers in the experimental beam has been
argued. No signature of non-metal to metal transition is observed in this size
range and the coordination dependence of $d-$electron localization is
discussed.",0606032v1
2007-05-02,Sr2CrOsO6: Endpoint of a spin polarized metal-insulator transition by 5d band filling,"In the search for new spintronic materials with high spin-polarization at
room-temperature, we have synthesized an osmium based double perovskite with a
Curie-temperature of 725 K. Our combined experimental results confirm the
existence of a sizable induced magnetic moment at the Os site, supported by
band-structure calculations in agreement with a proposed kinetic energy driven
mechanism of ferrimagnetism in these compounds. The intriguing property of
Sr2CrOsO6 is that it is at the endpoint of a metal-insulator transition due to
5d band filling, and at the same time ferrimagnetism and high-spin polarization
is preserved.",0705.0336v1
2007-06-19,Probing the Role of the Barrier Layer in Magnetic Tunnel Junction Transport,"Magnetic tunnel junctions with a ferrimagnetic barrier layer have been
studied to understand the role of the barrier layer in the tunneling process -
a factor that has been largely overlooked until recently. Epitaxial oxide
junctions of highly spin polarized La0.7Sr0.3MnO3 and Fe3O4 electrodes with
magnetic NiMn2O4 (NMO) insulating barrier layers provide a magnetic tunnel
junction system in which we can probe the effect of the barrier by comparing
junction behavior above and below the Curie temperature of the barrier layer.
When the barrier is paramagnetic, the spin polarized transport is dominated by
interface scattering and surface spin waves; however, when the barrier is
ferrimagnetic, spin flip scattering due to spin waves within the NMO barrier
dominates the transport.",0706.2726v2
2007-09-21,Magnetism of NiMn2O4-Fe3O4 Spinel Interfaces,"We investigate the magnetic properties of the isostructural spinel-spinel
interface of NiMn2O4(NMO)-Fe3O4. Although the magnetic transition temperature
of the NMO film is preserved, both bulk and interface sensitive measurements
demonstrate that the interface exhibits strong interfacial magnetic coupling up
to room temperature. While NMO thin films have a ferrimagnetic transition
temperature of 60K, both NiFe2O4 and MnFe2O4 are ferrimagnetic at room
temperature. Our experimental results suggest that these magnetic properties
arise from a thin interdiffused region of (Fe,Mn,Ni)3O4 at the interface
leading to Mn and Ni magnetic properties similar to MnFe2O4 and NiFe2O4.",0709.3518v2
2007-10-18,Numerical Study of a Three-Dimensional Mixed Ising Ferrimagnet in the Presence of an External Field,"We present a numerical study based on Monte Carlo algorithm of the magnetic
properties of a mixed Ising ferrimagnetic model on a cubic lattice where spins
$\sigma =\pm 1/2$ and spins $S=0,\pm 1$ are in alternating sites on the
lattice. We carried out exact ground state calculations and employ a Monte
Carlo simulation to obtain the finite-temperature phase diagram of the model. A
compensation point appears when the next-nearest-neighbor interaction between
the spins $\sigma =\pm 1/2$ exceeds a minimum value. We found a strong
dependence of the compensation temperature with the interactions in the
Hamiltonian, particulary the crystal field and the external field. An applied
field can change the range of values of the compensation temperature from zero
up to a maximum value that depends on the field.",0710.3592v1
2007-12-14,Ordered Phases of the Anisotropic Kagome Lattice Antiferromagnet in a Field,"The antiferromagnetic Heisenberg model on an anisotropic kagome lattice may
be a good minimal model for real magnetic systems as well as a limit from which
the isotropic case can be better understood. We therefore study the
nearest-neighbor Heisenberg antiferromagnet on an anisotropic kagome lattice in
a magnetic field. Such a system should be well described by weakly interacting
spin chains, and we motivate a general form for the interaction by symmetry
considerations and by perturbatively projecting out the inter-chain spins. In
the spin 1/2 case, we find that the system exhibits a quantum phase transition
from a ferrimagnetic ordered state to an XY ordered state as the field is
increased. Finally, we discuss the appearance of magnetization plateaux in the
ferrimagnetic phase.",0712.2269v1
2008-01-15,Fundamentals of half-metallic Full-Heusler alloys,"Intermetallic Heusler alloys are amongst the most attractive half-metallic
systems due to the high Curie temperatures and the structural similarity to the
binary semiconductors. In this review we present an overview of the basic
electronic and magnetic properties of the half-metallic full-Heusler alloys
like Co$_2$MnGe. Ab-initio results suggest that the electronic and magnetic
properties in these compounds are intrinsically related to the appearance of
the minority-spin gap. The total spin magnetic moment in the unit cell, $M_t$,
scales linearly with the number of the valence electrons, $Z_t$, such that
$M_t=Z_t-24$ for the full-Heusler alloys opening the way to engineer new
half-metallic alloys with the desired magnetic properties. Moreover we present
analytical results on the disorder in Co$_2$Cr(Mn)Al(Si) alloys, which is
susceptible to destroy the perfect half-metallicity of the bulk compounds and
thus degrade the performance of devices. Finally we discuss the appearance of
the half-metallic ferrimagnetism due to the creation of Cr(Mn) antisites in
these compounds and the Co-doping in Mn$_2$VAl(Si) alloys which leads to the
fully-compensated half-metallic ferrimagnetism.",0801.2252v1
2008-06-10,Ferrimagnetism of MnV_2O_4 spinel,"The spinel MnV_2O_4 is a two-sublattice ferrimagnet, with site A occupied by
the Mn^{2+} ion and site B by the V^{3+} ion. The magnon of the system, the
transversal fluctuation of the total magnetization, is a complicated mixture of
the sublattice A and B transversal magnetic fluctuations. As a result, the
magnons' fluctuations suppress in a different way the manganese and vanadium
magnetic orders and one obtains two phases. At low temperature (0,T^*) the
magnetic orders of the Mn and V ions contribute to the magnetization of the
system, while at the high temperature (T^*,T_N), the vanadium magnetic order is
suppressed by magnon fluctuations, and only the manganese ions have non-zero
spontaneous magnetization. A modified spin-wave theory is developed to describe
the two phases and to calculate the magnetization as a function of temperature.
The anomalous $M(T)$ curve reproduces the experimentally obtained ZFC
magnetization.",0806.1641v1
2008-08-10,Formation of guided spin-wave bullets in ferrimagnetic film stripes,"The formation of quasi-2D nonlinear spin-wave eigenmodes in longitudinally
magnetized stripes of a ferrimagnetic film, so-called guided spin-wave bullets,
was experimentally observed by using time- and space-resolved Brillouin light
scattering spectroscopy and confirmed by numerical simulation. They represent
stable spin-wave packets propagating along a waveguide structure, for which
both transversal instability and interaction with the side edges of the
waveguide are important. The experiments and the numerical simulation of the
evolution of the spin-wave excitations show that the shape of the formed
packets and their behavior are strongly influenced by the confinement
conditions. The discovery of these modes demonstrates the existence of
quasi-stable nonlinear solutions in the transition regime between
one-dimensional and two-dimensional wave packet propagation.",0808.1399v1
2008-08-14,High-output CPP-GMR sensor with synthetic-ferrimagnet free layer and enhanced spin-torque critical currents,"It is shown that the maximum stable output of a CPP-GMR sensor is increased
significantly by using a synthetic ferrimagnet free layer, provided the
electron current flows from free layer to reference layer. This free layer
allows a larger magnetoresistance ratio for a given free layer magnetic moment,
and in addition results in a greater than three-fold increase in the critical
current above which spin-torque instability of the free layer occurs. In read
heads with net free layer moments equivalent to only 4.5nm of Ni80Fe20, this
effect is shown to result in sustainable sense current densities above 2e8
A/cm2.",0808.2001v1
2008-10-02,Structural phase stability and Magnetism in Co2FeO4 spinel oxide,"We report a correlation between structural phase stability and magnetic
properties of Co2FeO4 spinel oxide. We employed mechanical alloying and
subsequent annealing to obtain the desired samples. The particle size of the
samples changes from 25 nm to 45 nm. The structural phase separation of
samples, except sample annealed at 9000C, into Co rich and Fe rich spinel phase
has been examined from XRD spectrum, SEM picture, along with EDAX spectrum, and
magnetic measurements. The present study indicated the ferrimagnetic character
of Co2FeO4, irrespective of structural phase stability. The observation of
mixed ferrimagnetic phases, associated with two Curie temperatures at TC1 and
TC2 (>TC1), respectively, provides the additional support of the splitting of
single cubic spinel phase in Co2FeO4 spinel oxide.",0810.0449v1
2008-10-22,Exchange bias effect in the phase separated Nd_{1-x}Sr_{x}CoO_3 at the spontaneous ferromagnetic/ferrimagnetic interface,"We report the new results of exchange bias effect in Nd_{1-x}Sr_{x}CoO_3 for
x = 0.20 and 0.40, where the exchange bias phenomenon is involved with the
ferrimagnetic (FI) state in a spontaneously phase separated system. The
zero-field cooled magnetization exhibits the FI (T_{FI}) and ferromagnetic
(T_C) transitions at ~ 23 and \sim 70 K, respectively for x = 0.20. The
negative horizontal and positive vertical shifts of the magnetic hysteresis
loops are observed when the system is cooled through T_{FI} in presence of a
positive static magnetic field. Training effect is observed for x = 0.20, which
could be interpreted by a spin configurational relaxation model. The
unidirectional shifts of the hysteresis loops as a function of temperature
exhibit the absence of exchange bias above T_{FI} for x = 0.20. The analysis of
the cooling field dependence of exchange bias field and magnetization indicates
that the ferromagnetic (FM) clusters consist of single magnetic domain with
average size around \sim 20 and ~ 40 \AA ~ for x = 0.20 and 0.40, respectively.
The sizes of the FM clusters are close to the percolation threshold for x =
0.20, which grow and coalesce to form the bigger size for x = 0.40 resulting in
a weak exchange bias effect.",0810.4013v1
2009-01-07,Real Space Visualization of Thermomagnetic Irreversibility within Supercooling and Superheating Spinodals in $Mn_{1.85}Co_{0.15}Sb$ using Scanning Hall Probe Microscopy,"Phase coexistence across disorder-broadened and magnetic-field-induced first
order antiferromagnetic to ferrimagnetic transition in polycrystalline
$Mn_{1.85}Co_{0.15}Sb$ has been studied mesoscopically by Scanning Hall Probe
Microscope at 120K and up to 5 Tesla magnetic fields. We have observed
hysteresis with varying magnetic field and the evolution of coexisting
antiferromagnetic and ferrimagnetic state on mesoscopic length scale. These
studies show that the magnetic state of the system at low field depends on the
path followed to reach 120 K. The low field magnetic states are mesoscopically
different for virgin and second field increasing cycle when 120 K is reached by
warming from 5K, but are the same within measurement accuracy when the
measuring temperature of 120K is reached from 300K by cooling.",0901.0758v1
2009-03-13,Half-metallic ferrimagnetism in the [Sc$_{1-x}$V$_x$]C and [Sc$_{1-x} $V$_x$]Si alloys adopting the zinc-blende and wurtzite structures from first-principles,"Employing first-principles calculations we study the structural, electronic
and magnetic properties of the [Sc$_{1-x}$V$_x$]C and [Sc$_{1-x}$V$_x$]Si
alloys. In their equilibrium rocksalt structure all alloys are non-magnetic.
The zincblende and wurtzite structures are degenerated with respect to the
total energy. For all concentrations the alloys in these lattice structures are
half-metallic with the gap located in the spin-down band. The total spin moment
follows the Slater-Pauling behavior varying linearly between the -1 $\mu_B$ of
the perfect ScC and ScSi alloys and the +1 $\mu_B$ of the perfect VC and VSi
alloys. For the intermediate concentrations V and Sc atoms have antiparallel
spin magnetic moments and the compounds are half-metallic ferrimagnets. At the
critical concentration, both [Sc$_{0.5}$V$_{0.5}$]C and [Sc$_{0.5}$V$_{0.5}$]Si
alloys present zero total spin-magnetic moment but the C-based alloy shows a
semiconducting behavior contrary to the Si-based alloys which is a
half-metallic antiferromagnet.",0903.2331v1
2009-04-24,Factorized ground state for a general class of ferrimagnets,"We have found the exact (factorized) ground state of a general class of
ferrimagnets in the presence of a magnetic field which covers the frustrated,
anisotropic and long range interactions for arbitrary dimensional space. In
particular cases, our model represents the bond-alternating,
ferromagnet-antiferromagnet and also homogeneous spin $s$ model. The factorized
ground state is a product of single particle kets on a bipartite lattice
composed of two different spins ($\rho, \sigma$). The spin waves analysis
around the exact ground state show two branch of excitations which is the
origin of two dynamics of the model. The signature of these dynamics is
addressed as a peak and a broaden bump in the specific heat.",0904.3843v3
2009-06-18,Intrinsic exchange bias in Zn$_x$Mn$_{3-x}$O$_4$ ($x \leq 1$) solid solutions,"Bulk specimens of the hetaerolite solid solution Zn$_x$Mn$_{3-x}$O$_4$, with
$x$ = 0, 0.25, 0.5, 0.75, and 1 have been prepared as homogeneous, phase-pure
polycrystalline samples as ascertained by neutron diffraction measurements.
Samples with $x$ = 0.25, 0.5, and 0.75 exhibit shifted magnetic hysteresis
loops at low temperature, characteristic of exchange bias typically seen in
magnetic composites. We propose that the unusual magnetic behavior arises as a
result of a nanoscale mixture of ferrimagnetic and antiferromagnetic regions
that are distinct but lack long-range order. While some glassy behavior is seen
in AC magnetic measurements, its magnitude is not sufficient to account for the
observed dramatic exchange bias. Furthermore, isothermal and thermoremanent
magnetization measurements distinguish this material from a pure spin glass.
The title system offers insights into the alloying of a ferrimagnet Mn$_3$O$_4$
with an antiferromagnet ZnMn$_2$O$_4$ wherein distinct magnetic clusters grow
and percolate to produce a smooth transition between competing orders.",0906.3534v2
2009-06-26,Magnetic behavior of nanocrystalline ErCo2,"We have investigated the magnetic behavior of the nanocrystalline form of a
well-known Laves phase compound, ErCo2 - the bulk form of which has been known
to undergo an interesting first-order ferrimagnetic ordering near 32 K -
synthesized by high-energy ball-milling. It is found that, in these
nanocrystallites, Co exhibits ferromagnetic order at room temperature as
inferred from the magnetization data. However, the magnetic transition
temperature for Er sublattice remains essentially unaffected as though the
(Er)4f-Co(3d) coupling is weak on Er magnetism. The net magnetic moment as
measured at high fields, sat at 120 kOe, is significantly reduced with respect
to that for the bulk in the ferrimagnetically ordered state and possible
reasons are outlined. We have also compared the magnetocaloric behavior for the
bulk and the nano particles.",0906.4889v1
2009-09-01,Directional Dichroism of X-Ray Absorption in a Polar Ferrimagnet GaFeO_3,"We study the directional dichroic absorption spectra in the x-ray region in a
polar ferrimagnet GaFeO_3. The directional dichroism on the absorption spectra
at the Fe pre-K-edge arises from the E1-E2 interference process through the
hybridization between the 4p and 3d states in the noncentrosymmetric
environment of Fe atoms. We perform a microscopic calculation of the spectra on
a model of FeO_6 with reasonable parameter values for Coulomb interaction and
hybridizations. We obtain the difference in the absorption coefficients when
the magnetic field is applied parallel and antiparallel to the c axis. The
spectra shus obtained have similar shapes to the experimental curves as a
function of photon energy in the Fe pre-K-edge region, although they have
opposite signs.",0909.0079v1
2009-10-02,Effect of strain on the stability and electronic properties of ferrimagnetic Fe$_{2-x}$Ti$_x$O$_3$ heterostructures from correlated band theory,"Based on density functional theory (DFT) calculations including an on-site
Hubbard $U$ term we investigate the effect of substrate-induced strain on the
properties of ferrimagnetic Fe$_2$O$_3$-FeTiO$_3$ solid solutions and
heterostructures. While the charge compensation mechanism through formation of
a mixed \fetw, \feth-contact layer is unaffected, strain can be used to tune
the electronic properties of the system, e.g. by changing the position of
impurity levels in the band gap. Straining hematite/ilmenite films at the
lateral parameters of Al$_{2}$O$_{3}$(0001), commonly used as a substrate, is
found to be energetically unfavorable as compared to films on
Fe$_{2}$O$_{3}$(0001) or FeTiO$_{3}$(0001)-substrates.",0910.0422v1
2009-10-31,Compensation temperature of 3d mixed ferro-ferrimagnetic ternary alloy,"In this study, we have considered the three dimensional mixed
ferro-ferrimagnetic ternary alloy model of the type AB$_{p}$C$_{1-p}$ where the
A and X (X=B or C) ions are alternately connected and have different Ising
spins S$^{A}$=3/2, S$^{B}$=1 and S$^{C}$=5/2, respectively. We have
investigated the dependence of the critical and compensation temperatures of
the model on concentration and interaction parameters by using MC simulation
method. We have shown that the behavior of the critical temperature and the
existence of compensation points strongly depend on interaction and
concentration parameters. In particular, we have found that the critical
temperature of the model is independent on concentration of different types of
spins at a special interaction value and the model has one or two compensation
temperature points in a certain range of values of the concentration of the
different spins.",0911.0078v1
2009-11-06,Frustrated spin ladder with alternating spin-1 and spin-1/2 rungs,"We study the impact of the diagonal frustrating couplings on the quantum
phase diagram of a two-leg ladder composed of alternating spin-1 and spin-1/2
rungs. As the coupling strength is increased the system successively exhibits
two gapped paramagnetic phases (a rung-singlet and a Haldane-like
non-degenerate states) and two ferrimagnetic phases with different
ferromagnetic moments per rung. The first two states are similar to the phases
studied in the frustrated spin-1/2 ladder, whereas the magnetic phases appear
as a result of the mixed-spin structure of the model. A detailed
characterization of these phases is presented using density-matrix
renormalization-group calculations, exact diagonalizations of periodic
clusters, and an effective Hamiltonian approach inspired by the analysis of
numerical data. The present theoretical study was motivated by the recent
synthesis of the quasi-one-dimensional ferrimagnetic material
Fe$^{II}$Fe$^{III}$ (trans-1,4-cyclohexanedicarboxylate) exhibiting a similar
ladder structure.",0911.1216v2
2010-02-01,Crystal and electronic structure of the room temperature organometallic ferrimagnet V(TCNE)$_2$. Analysis of numerical DoS and magnetic properties as related to orbital and spin-Hamiltonian models,"We present a detailed analysis of the results of our numerical study of the
crystal and electronic structure of the room temperature organometallic
ferrimagnet of general composition V(TCNE)$_{x}$ with $% x\approx 2$. The
results of the LSDA+$U$ study show that the experimentally determined structure
complies with the magnetic measurements and thus can serve as a prototype
structure for the entire family of the M(TCNE)$_{2}$ organometallic magnets.
The results of the numerical study and of the magnetic experiments are
interpreted using model Hamiltonians proposed here. This allowed us to obtain
estimates of the critical temperature in three- and two-dimensional regimes and
to give an explanation of the differences in behavior of probably isostructural
V(TCNE)$_{2}$ and Fe(TCNE)$_{2}$ species.",1002.0236v1
2010-07-12,Second harmonic generation in a polar ferrimagnet GaFeO3,"We have studied second harmonic generation (SHG) in a polar ferrimagnet
GaFeO_3, employing a FeO_6 cluster model in which the Fe atom is slightly
shifted from the center of the octahedron. The electric-dipole transition could
take place between the 3d states through the effective hybridization of the 4p
states with the 3d states, due to the breaking of the space-inversion symmetry.
In the third-order perturbation with H_{int} = -(j.A)/c, we calculate the
probability per unit time, I_{\eta aa}, for the process that two photons are
absorbed with polarization parallel to the $a$ axis and one photon is emitted
with polarization parallel to the \eta (=a,b,c) axis. The calculated SHG
intensities consist of several peaks as a function of two-photon energy in
agreement with the experiments. It is found that the corresponding amplitude
S_{aaa} at each Fe site changes its sign while S_{baa} remains the same with
the reversal of the direction of the local magnetic moment. This implies that
I_{aaa} would disappear while I_{baa} would survive in the paramagnetic phase
in accordance with the experiment.",1007.1856v1
2010-08-03,Electrical spin injection from an organic-based ferrimagnet in a hybrid organic/inorganic heterostructure,"We report the successful extraction of spin polarized current from the
organic-based room temperature ferrimagnetic semiconductor V[TCNE]x (x~2, TCNE:
tetracyanoethylene; TC ~ 400 K, EG ~ 0.5 eV, s ~ 10-2 S/cm) and its subsequent
injection into a GaAs/AlGaAs light-emitting diode (LED). The spin current
tracks the magnetization of V[TCNE]x~2, is weakly temperature dependent, and
exhibits heavy hole / light hole asymmetry. This result has implications for
room temperature spintronics and the use of inorganic materials to probe spin
physics in organic and molecular systems.",1008.0675v2
2010-08-11,Ferrimagnetism of the magnetoelectric compound Cu$_2$OSeO$_3$ probed by $^{77}$Se NMR,"We present a thorough $^{77}$Se NMR study of a single crystal of the
magnetoelectric compound Cu$_2$OSeO$_3$. The temperature dependence of the
local electronic moments extracted from the NMR data is fully consistent with a
magnetic phase transition from the high-T paramagnetic phase to a low-T
ferrimagnetic state with 3/4 of the Cu$^{2+}$ ions aligned parallel and 1/4
aligned antiparallel to the applied field of 14.09 T. The transition to this
3up-1down magnetic state is not accompanied by any splitting of the NMR lines
or any abrupt modification in their broadening, hence there is no observable
reduction of the crystalline symmetry from its high-T cubic \textit{P}2$_1$3
space group. These results are in agreement with high resolution x-ray
diffraction and magnetization data on powder samples reported previously by Bos
{\it et al.} [Phys. Rev. B, {\bf 78}, 094416 (2008)]. We also develop a mean
field theory description of the problem based on a microscopic spin Hamiltonian
with one antiferromagnetic ($J_\text{afm}\simeq 68$ K) and one ferromagnetic
($J_\text{fm}\simeq -50$ K) nearest-neighbor exchange interaction.",1008.2010v1
2011-01-31,Complex room temperature ferrimagnetism induced by zigzag oxygen-vacancy stripes in Sr3YCo4O10.72,"The high temperature ferromagnetism in Sr3YCo4O10+delta perovskite, whose
origin has been the subject of a considerable debate, has been studied by
neutron powder diffraction and synchrotron X-ray diffraction measurements.
Oxygen vacancy ordering creates a complex pattern of zigzag stripes in the
oxygen-deficient CoO4+delta layers, where the Co ions are found in three
distinct coordinations. The symmetry of this unprecedented structural
modulation, in conjunction with the existence of different Co spin states,
provide a straightforward explanation for the appearance of ferrimagnetism. A
model for the magnetic structure compatible with these structural features is
proposed, based on the refinement of powder neutron data. The macroscopic
moment as a function of temperature that can be calculated from the values of
the ordered spins extracted from refinements, is in excellent agreement with
bulk magnetization. Unlike previous models, a collinear G-type magnetic
structure with uncompensated moments due to distinct spin-states of Co imposed
by different coordination is found.",1101.5943v1
2011-06-20,Magnetic Order of the Hexagonal Rare Earth Manganite Dy(0.5)Y(0.5)MnO3,"Hexagonal Dy(0.5)Y(0.5)MnO3, a multiferroic rare-earth manganite with
geometrically frustrated antiferromagnetism, has been investigated with
single-crystal neutron diffraction measurements. Below 3.4 K magnetic order is
observed on both the Mn (antiferromagnetic) and Dy (ferrimagnetic) sublattices
that is identical to that of undiluted hexagonal DyMnO3 at low temperature. The
Mn moments undergo a spin reorientation transition between 3.4 K and 10 K, with
antiferromagnetic order of the Mn sublattice persisting up to 70 K; the
antiferromagnetic order in this phase is distinct from that observed in
undiluted (h)DyMnO3, yielding a qualitatively new phase diagram not seen in
other hexagonal rare-earth manganites. A magnetic field applied parallel to the
crystallographic c axis will drive a transition from the antiferromagnetic
phase into the low-temperature ferrimagnetic phase with little hysteresis.",1106.3966v2
2011-07-05,Theory of Half-metallic Ferrimagnetism in Double Perovskites,"We present a comprehensive theory of the temperature- and disorder-dependence
of half-metallic ferrimagnetism in the double perovskite Sr$_2$FeMoO$_6$ (SFMO)
with $T_c$ above room temperature. We show that the magnetization $M(T)$ and
conduction electron polarization $P(T)$ are both proportional to the
magnetization $M_S(T)$ of localized Fe spins. We derive and validate an
effective spin Hamiltonian, amenable to large-scale three-dimensional
simulations. We show how $M(T)$ and $T_c$ are affected by disorder, ubiquitous
in these materials. We suggest a way to enhance $T_c$ in SFMO without
sacrificing polarization.",1107.0983v2
2011-07-29,Ferrimagnetism and spontaneous ordering of transition-metals in La2CrFeO6 double-perovskite films,"We report on atomic ordering of B-site transition-metals and magnetic
properties of epitaxial La2CrFeO6 double-perovskite films grown by pulsed-laser
deposition under various conditions. The highest ordered sample exhibited a
fraction of antisite-disorder of only 0.05 and a saturation magnetization of
~2\mu_{B} per formula unit at 5 K. The result is consistent with the
antiferromagnetic ordering of local spin moment
(3d^{3}_{\downarrow}3d^{5}_{\uparrow}; S = -3/2+5/2 = 1). Therefore, the
magnetic ground state of La2CrFeO6 double-perovskite that has been long debate
is unambiguously revealed to be ferrimagnetic. Our results present a wide
opportunity to explore novel magnetic properties of binary transition-metal
perovskites upon epitaxial stabilization of the ordered phase.",1107.5891v1
2011-09-01,Unusual giant magnetostriction in the ferrimagnet Gd$_{2/3}$Ca$_{1/3}$MnO$_3$,"We report an unusual giant linear magnetostrictive effect in the ferrimagnet
Gd$_{2/3}$Ca$_{1/3}$MnO$_3$ ($T_{c} \approx$80 K). Remarkably, the
magnetostriction, negative at high temperature ($T \approx T_{c}$), becomes
positive below 15 K when the magnetization of the Gd sublattice overcomes the
magnetization of the Mn sublattice. A rather simple model where the magnetic
energy competes against the elastic energy gives a good account of the observed
results and confirms that Gd plays a crucial role in this unusual observation.
Unlike previous works in manganites where only striction associated with 3$d$
Mn orbitals is considered, our results show that the lanthanide 4$f$ orbitals
related striction can be very important too and it cannot be disregarded.",1109.0259v2
2011-10-20,Magnetism in nanometer-thick magnetite,"The oldest known magnetic material, magnetite, is of current interest for use
in spintronics as a thin film. An open question is how thin can magnetite films
be and still retain the robust ferrimagnetism required for many applications.
We have grown one-nanometer-thick magnetite crystals and characterized them in
situ by electron and photoelectron microscopies including selected-area x-ray
circular dichroism. Well-defined magnetic patterns are observed in individual
nano-crystals up to at least 520 K, establishing the retention of
ferrimagnetism in magnetite two-unit-cells thick.",1110.4568v1
2012-03-13,Magnetic ground state and 2D behavior in pseudo-Kagome layered system Cu3Bi(SeO3)2O2Br,"Anisotropic magnetic properties of a layered kagome-like system
Cu3Bi(SeO3)2O2Br have been studied by bulk magnetization and magnetic
susceptibility measurements as well as powder and single-crystal neutron
diffraction. At T_N = 27.4 K the system develops an alternating
antiferromagnetic order of (ab) layers, which individually exhibit canted
ferrimagnetic moment arrangement, resulting from the competing ferro- and
antiferro-magnetic intralayer exchange interactions. A magnetic field B_C ~ 0.8
T applied along the c axis (perpendicular to the layers) triggers a
metamagnetic transition, when every second layer flips, i.e., resulting in a
ferrimagnetic structure. Significantly higher fields are required to rotate the
ferromagnetic component towards the b axis (~7 T) or towards the a axis (~15
T). The estimates of the exchange coupling constants and features indicative of
an XY character of this quasi-2D system are presented.",1203.2782v2
2012-03-16,Universal low-temperature tricritical point in metallic ferromagnets and ferrimagnets,"An earlier theory of the quantum phase transition in metallic ferromagnets is
revisited and generalized in three ways. It is shown that the mechanism that
leads to a fluctuation-induced first-order transition in metallic ferromagnets
with a low Curie temperature is valid, (1) irrespective of whether the magnetic
moments are supplied by the conduction electrons or by electrons in another
band, (2) for ferromagnets in the XY and Ising universality classes as well as
for Heisenberg ferromagnets, and (3) for ferrimagnets as well as for
ferromagnets. This vastly expands the class of materials for which a
first-order transition at low temperatures is expected, and it explains why
strongly anisotropic ferromagnets, such as UGe2, display a first-order
transition as well as Heisenberg magnets.",1203.3826v1
2012-03-20,Is the Yb2Ti2O7 pyrochlore a quantum spin ice?,"We use numerical linked cluster (NLC) expansions to compute the specific
heat, C(T), and entropy, S(T), of a quantum spin ice model of Yb2Ti2O7 using
anisotropic exchange interactions recently determined from inelastic neutron
scattering measurements and find good agreement with experimental calorimetric
data. In the perturbative weak quantum regime, this model has a ferrimagnetic
ordered ground state, with two peaks in C(T): a Schottky anomaly signalling the
paramagnetic to spin ice crossover followed at lower temperature by a sharp
peak accompanying a first order phase transition to the ferrimagnetic state. We
suggest that the two C(T) features observed in Yb2Ti2O7 are associated with the
same physics. Spin excitations in this regime consist of weakly confined
spinon-antispinon pairs. We suggest that conventional ground state with exotic
quantum dynamics will prove a prevalent characteristic of many real quantum
spin ice materials.",1203.4569v1
2012-06-28,Frequency and power dependence of spin-current emission by spin pumping in a thin film YIG/Pt system,"This paper presents the frequency dependence of the spin current emission in
a hybrid ferrimagnetic insulator/normal metal system. The system is based on a
ferrimagnetic insulating thin film of Yttrium Iron Garnet (YIG, 200 nm) grown
by liquid-phase-epitaxy (LPE) coupled with a normal metal with a strong
spin-orbit coupling (Pt, 15 nm). The YIG layer presents an isotropic behaviour
of the magnetization in the plane, a small linewidth, and a roughness lower
than 0.4 nm. Here we discuss how the voltage signal from the spin current
detector depends on the frequency [0.6 - 7 GHz], the microwave power, Pin, [1 -
70 mW], and the in-plane static magnetic field. A strong enhancement of the
spin current emission is observed at low frequencies, showing the appearance of
non-linear phenomena.",1206.6671v2
2012-06-28,Reentrant phase transitions and multicompensation points in the mixed-spin Ising ferrimagnet on a decorated Bethe lattice,"Mixed-spin Ising model on a decorated Bethe lattice is rigorously solved by
combining the decoration-iteration transformation with the method of exact
recursion relations. Exact results for critical lines, compensation
temperatures, total and sublattice magnetizations are obtained from a precise
mapping relationship with the corresponding spin-1/2 Ising model on a simple
(undecorated) Bethe lattice. The effect of next-nearest-neighbour interaction
and single-ion anisotropy on magnetic properties of the ferrimagnetic model is
investigated in particular. It is shown that the total magnetization may
exhibit multicompensation phenomenon and the critical temperature vs. the
single-ion anisotropy dependence basically changes with the coordination number
of the underlying Bethe lattice. The possibility of observing reentrant phase
transitions is related to a high enough coordination number of the underlying
Bethe lattice.",1206.6684v1
2012-07-21,"Quantum phase transitions in alternating spin-(1/2, 5/2) Heisenberg chains","The ground state spin-wave excitations and thermodynamic properties of two
types of ferrimagnetic chains are investigated: the alternating spin-1/2
spin-5/2 chain and a similar chain with a spin-1/2 pendant attached to the
spin-5/2 site. Results for magnetic susceptibility, magnetization and specific
heat are obtained through the finite-temperature Lanczos method with the aim in
describing available experimental data, as well as comparison with theoretical
results from the semiclassical approximation and the low-temperature
susceptibility expansion derived from Takahashi's modified spin-wave theory. In
particular, we study in detail the temperature vs. magnetic field phase diagram
of the spin-1/2 spin-5/2 chain, in which several low-temperature quantum phases
are identified: the Luttinger Liquid phase, the ferrimagnetic plateau and the
fully polarized one, and the respective quantum critical points and crossover
lines.",1207.5084v1
2012-10-13,Promising ferrimagnetic double perovskite oxides towards high spin polarization at high temperature,"We predict through our first-principles calculations that four double
perovskite oxides of Bi2ABO6 (AB = FeMo, MnMo, MnOs, CrOs) are half-metallic
ferrimagnets. Our calculated results shows that the four optimized structures
have negative formation energy, from -0.42 to -0.26 eV per formula unit, which
implies that they could probably be realized. In the case of Bi2FeMoO6, the
half-metallic gap and Curie temperature are predicted to reach to 0.71 eV and
650 K, respectively, which indicates that high spin polarization could be kept
at high temperatures far beyond room temperature. It is believed that some of
them could be synthesized soon and would prove useful for spintronic
applications.",1210.3706v2
2012-10-16,Mn$_2$FeSbO$_6$: a ferrimagnetic ilmenite and an antiferromagnetic perovskite,"Due of its polymorphism, Mn$_2$FeSbO$_6$ can be synthesized at high pressures
and temperatures as a ferrimagnetic ilmenite or an antiferromagnetic
perovskite. The structural phase transformation is discussed in detail, and
magnetic structures are proposed for both phases. The high-pressure
Mn$_2$FeSbO$_6$ polymorph is a rare example of $A_2 B'B""$O$_6$ perovskite with
solely Mn cations on the $A$-site. Fe and Sb cations are ordered on the
$B$-sites. Theoretical calculations for the perovskite phase suggest a complex
magnetic structure, holding an electronic polarization.",1210.4368v2
2012-12-21,Phase diagram of a mixed spin-1 and spin-3/2 Ising ferrimagnet,"Critical and compensation properties of a mixed spin-1 and spin-3/2 Ising
ferrimagnet on a square lattice are investigated by standard and histogram
Monte Carlo simulations. The critical temperature is studied as a function of a
single-ion anisotropy strength. The second order of the phase transition is
established by finite-size scaling for the entire boundary. Some previously
obtained results, such as a tricritical point, predicted by the mean field
theory (MFT) and effective field theory (EFT), or a first-order transition line
separating two different ordered phases, obtained by the cluster variational
theory (CVT), are deemed artifacts of the respective approximations. So is a
reentrant phenomenon produced by CVT. Nevertheless, the multicompensation
behavior predicted by MFT and EFT was confirmed.",1212.5471v1
2012-12-25,"Magnetic properties, Lyapunov exponent and superstability of the spin-1/2 Ising-Heisenberg model on diamond chain","The exactly solvable spin-1/2 Ising-Heisenberg model on diamond chain has
been considered. We have found the exact results for the magnetization by using
recursion relation method. The existence of the magnetization plateau has been
observed at one third of the saturation magnetization in the antiferromagnetic
case. Some ground-state properties of the model are examined. At low
temperatures, the system has two ferrimagnetic (FRI1 and FRI2) phases and one
paramagnetic (PRM) phase. Lyapunov exponents for the various values of the
exchange parameters and temperatures have been analyzed. It have also been
shown that the maximal Lyapunov exponent exhibits plateau. Lyapunov exponents
exhibit different behavior for two ferrimagnetic phases. We have found the
existence of the supercritical point for the multi-dimensional rational mapping
of the spin-1/2 Ising-Heisenberg model on diamond chain for the first time at
absence of the external magnetic field and $T \rightarrow 0$ in the
antiferromagnetic case.",1212.6008v1
2013-01-11,Spin-filtering efficiency of ferrimagnetic spinels CoFe2O4 and NiFe2O4,"We assess the potential of the ferrimagnetic spinel ferrites CoFe2O4 and
NiFe2O4 to act as spin filtering barriers in magnetic tunnel junctions. Our
study is based on the electronic structure calculated by means of
first-principles density functional theory within different approximations for
the exchange correlation energy. We show that, in agreement with previous
calculations, the densities of states suggest a lower tunneling barrier for
minority spin electrons, and thus a negative spin-filter effect. However, a
more detailed analysis based on the complex band-structure reveals that both
signs for the spin-filtering efficiency are possible, depending on the band
alignment between the electrode and the barrier materials and depending on the
specific wave-function symmetry of the relevant bands within the electrode.",1301.2541v1
2013-01-30,Thermally driven spin and charge currents in thin NiFe2O4/Pt films,"We present results on the longitudinal spin Seebeck effect (LSSE) shown by
semiconducting ferrimagnetic NiFe2O4/Pt films from room temperature down to 50K
base temperature. To the best of our knowledge, this is the first observation
of spin caloric effect in NiFe2O4 thin films. The temperature dependence of the
conductivity has been studied in parallel to obtain information about the
origin of the electric potentials detected at the Pt coverage of the
ferrimagnet in order to distinguish the LSSE from the anomalous Nernst effect.
Furthermore, the dependence of the LSSE on temperature gradients as well as the
influence of an external magnetic field direction is investigated.",1301.7313v1
2013-02-11,Phase stability of chromium based compensated ferrimagnets with inverse Heusler structure,"Chromium based inverse Heusler compounds of the type Cr2YZ (Y=Co, Fe; Z=Al,
Ga, In, Si, Ge, Sn) have been proposed as fully compensated half-metallic
ferrimagnets. Such materials are of large interest for spintronics because they
combine small magnetic moment with high spin polarization over a wide
temperature range. We assess their thermodynamic stability by their formation
enthalpies obtained from density functional theory calculations. All compounds
under investigation are unstable. Cr2FeSi and Cr2CoAl are stable with respect
to the elemental constituents, but decompose into binary phases. Cr2FeGe,
Cr2CoGa, Cr2FeSn and Cr2CoIn are found to be unstable with respect to their
elemental constituents. We identify possible binary decompositions.",1302.2487v2
2013-02-21,Large zero-field cooled exchange-bias in bulk Mn2PtGa,"We report a large exchange-bias (EB) effect after zero-field cooling the new
tetragonal Heusler compound Mn2PtGa from the paramagnetic state. The
first-principle calculation and the magnetic measurements reveal that Mn2PtGa
orders ferrimagnetically with some ferromagnetic (FM) inclusions. We show that
ferrimagnetic (FI) ordering is essential to isothermally induce the exchange
anisotropy needed for the zero-field cooled (ZFC) EB during the virgin
magnetization process. The complex magnetic behavior at low temperatures is
characterized by the coexistence of a field induced irreversible magnetic
behavior and a spin-glass-like phase. The field induced irreversibility
originates from an unusual first-order FI to antiferromagnetic transition,
whereas, the spin-glass like state forms due to the existence of anti-site
disorder intrinsic to the material.",1302.5229v1
2013-04-16,Kinetic arrest related to a first-order ferrimagnetic to antiferromagnetic transition in the Heusler compound Mn2PtGa,"We report a magnetization study of the Heusler compound Mn2PtGa that shows
the existence of a magnetic-glass state. Mn2PtGa shows a first-order
ferromagnetic (FM)/ferrimagnetic (FI) to antiferromagnetic (AFM) transition in
contrast to the martensitic structural transition observed in several Heusler
alloys. The kinetic arrest of this first-order FM (FI) to AFM transition leads
to the observed magnetic-glass behavior. We show that the strength of the
applied magnetic field, which is the primary parameter to induce the
magnetic-glass state, is also responsible for the stability of the supercooled
FM (FI) phase in time.",1304.4459v1
2013-04-29,The Mixed Spin 3 - Spin 3/2 Ferrimagnetic Ising Model on Cellular Automaton,"The mixed spin 3- spin 3/2 Ising model has been simulated using cooling
algorithm on cellular automaton (CA). The simulations have been made in the
interval -6<=D<=6 for J=1 for the square lattices with periodic boundary
conditions. The ground state phase diagram of the model has different type
ferrimagnetic orderings. Through D/J=2 line, compensation points occurs at
kT/J=0. The values of the critical exponents ( {\nu}, {\alpha}, {\beta} and
{\gamma}) are estimated within the framework of the finite-size scaling theory
and power law relations for selected D/J values (-2, 0, 1, 2 and 4). The
estimated critical exponent values are in a good agreement with their universal
values of the two dimensional Ising model.",1304.7740v3
2013-06-17,Tailoring the ground state of the ferrimagnet La2Ni(Ni1/3Sb2/3)O6,"We report on the magnetic and structural properties of La2Ni(Ni1/3Sb2/3)O6 in
polycrystal, single crystal and thin film samples. We found that this material
is a ferrimagnet (Tc ~ 100 K) which possesses a very distinctive and uncommon
feature in its virgin curve of the hysteresis loops. We observe that bellow 20
K it lies outside the hysteresis cycle, and this feature was found to be an
indication of a microscopically irreversible process possibly involving the
interplay of competing antiferromagnetic interactions that hinder the initial
movement of domain walls. This initial magnetic state is overcome by applying a
temperature dependent characteristic field. Above this field, an isothermal
magnetic demagnetization of the samples yield a ground state different from the
initial thermally demagnetized one.",1306.3894v1
2013-10-31,Ground-State Phase Diagram of S=2 Heisenberg Chains with Alternating Single-Site Anisotropy,"The ground-state phase diagram of $S=2$ antiferromagnetic Heisenberg chains
with coexisting uniform and alternating single-site anisotropies is
investigated by the numerical exact diagonalization and density matrix
renormalization group methods. We find the Haldane, large-$D$, N\'eel,
period-doubled N\'eel, gapless spin fluid, quantized and partial ferrimagnetic
phases. The Haldane phase is limited to the close neighborhood of the isotropic
point. Within numerical accuracy, the transition from the gapless spin-fluid
phase to the period-doubled N\'eel phase is a direct transition. Nevertheless,
the presence of a narrow spin-gap phase between these two phases is suggested
on the basis of the low-energy effective theory. The ferrimagnetic ground state
is present in a wide parameter range. This suggests the realization of
magnetized single-chain magnets with a uniform spin magnitude by controlling
the environment of each magnetic ion without introducing ferromagnetic
interactions.",1310.8586v2
2013-11-13,Exchange bias up to room temperature in the antiferromagnetic bulk hexagonal Mn3Ge,"This work reports an exchange bias (EB) effect up to room temperature in the
binary intermetallic bulk compound Mn3.04Ge0.96. The sample annealed at 700 K
crystallizes in a tetragonal structure with ferromagnetic ordering, whereas,
the sample annealed at 1073 K crystallizes in a hexagonal structure with
antiferromagnetic ordering. The hexagonal Mn3.04Ge0.96 sample exhibits an EB of
around 70 mT at 2 K that continues with a non-zero value up to room
temperature. The exchange anisotropy is proposed to be originating from the
exchange interaction between the triangular antiferromagnetic host and the
embedded ferrimagnetic like clusters. The ferrimagnetic clusters develop when
excess Mn atoms occupy empty Ge sites in the original triangular
antiferromagnet structure of Mn3Ge.",1311.3067v1
2013-11-14,Nonequilibrium dynamics of a mixed spin-1/2 and spin-3/2 Ising ferrimagnetic system with a time dependent oscillating magnetic field source,"Nonequilibrium phase transition properties of a mixed Ising ferrimagnetic
model consisting of spin-1/2 and spin-3/2 on a square lattice under the
existence of a time dependent oscillating magnetic field have been investigated
by making use of Monte Carlo simulations with single-spin flip Metropolis
algorithm. A complete picture of dynamic phase boundary and magnetization
profiles have been illustrated and the conditions of a dynamic compensation
behavior have been discussed in detail. According to our simulation results,
the considered system does not point out a dynamic compensation behavior, when
it only includes the nearest-neighbor interaction, single-ion anisotropy and an
oscillating magnetic field source. As the next-nearest-neighbor interaction
between the spins-1/2 takes into account and exceeds a characteristic value
which sensitively depends upon values of single-ion anisotropy and only of
amplitude of external magnetic field, a dynamic compensation behavior occurs in
the system. Finally, it is reported that it has not been found any evidence of
dynamically first-order phase transition between dynamically ordered and
disordered phases, which conflicts with the recently published molecular field
investigation, for a wide range of selected system parameters.",1311.3537v2
2013-12-12,Exact results for a generalized spin-1/2 Ising-Heisenberg diamond chain with the second-neighbor interaction between nodal spins,"The ground state and thermodynamics of a generalized spin-1/2
Ising-Heisenberg diamond chain with the second-neighbor interaction between
nodal spins are calculated exactly using the mapping method based on the
decoration-iteration transformation. Rigorous results for the magnetization,
susceptibility, and heat capacity are investigated in dependence on temperature
and magnetic field for the frustrated diamond spin chain with the
antiferromagnetic Ising and Heisenberg interactions. It is demonstrated that
the second-neighbor interaction between nodal spins gives rise to a greater
diversity of low-temperature magnetization curves, which may include an
intermediate plateau at two-third of the saturation magnetization related to
the classical ferrimagnetic (up-up-up-down-up-up-...) ground state with
translationally broken symmetry besides an intermediate one-third magnetization
plateau reflecting the translationally invariant quantum ferrimagnetic
(monomer-dimer) spin arrangement.",1312.3439v1
2014-04-28,High-Curie-temperature ferrimagnetism and ferroelectricity in Bi2FeMoO6,"BiFeO3 is the most famous multiferroic material, but its G-type
antiferromagnetism is highly desirable to be replaced by strong macroscopic
magnetism beyond room temperature. Here we obtain double perovskite Bi2FeMoO6
with R3 (#146) space group by substituting Mo for 50% Fe in BiFeO3. Our
first-principles calculated results show that it is a semiconductor with gap
reaching to 0.725 eV, its net magnetic moment is 2\mu_B per formula unit, and
its ferroelectric polarization is 85\mu C/cm^2. This ferroelctricity is
comparable with that of BiFeO3, but here the magnetism is a strong
ferrimagnetism with Curie temperature of 650 K. Our first-principles phonon
spectra establishes that this R3 phase is stable. Electric polarization and
magnetic easy axis are shown to be in pseudo-cubic [111] axis. Our further
analysis shows that the multiferroic mechanism is similar to that in BiFeO3.
Therefore, this Bi2FeMoO6 can be used to achieve strong macroscopic magnetism
and ferroelectricity well above room temperature, being useful for designing
new multifunctional materials and devices.",1404.7058v2
2014-08-08,Half Metal Transition Driven by Doping Effects in Osmium Double Perovskite,"Using the first-principles density functional approach, we investigate
Ca$_2$FeOsO$_6$, a material of double perovskite structure synthesized
recently. According to the calculations, Ca$_2$FeOsO$_6$ is a ferrimagnetic
Mott-insulator influenced by the cooperative effect of spin-orbit coupling
(SOC) and Coulomb interactions of Fe-3$d$ and Os-5$d$ electrons, as well as the
crystal field. When Fe is replaced with Ni, the system exhibits half metallic
(HM) states desirable for spintronic applications. In
[Ca$_2$Fe$_{1-x}$Ni$_x$OsO$_6$]$_2$, HM ferrimagnetism is observed with
$\mu_{\rm tot}=2\mu_{\rm B}$ per unit cell for doping rate $x=0.5$, whereas HM
antiferromagnetism (HMAFM) with nearly zero spin magnetization in the unit cell
for $x=1$, respectively. It is emphasized that half metallicity is retained
even with SOC effect due to the large exchange-splitting between spin-up and
spin-down bands close to the Fermi level.",1408.1771v1
2014-10-16,"Understanding the Magnetic Puzzles of Double Perovskites A2FeOsO6 (A=Ca, Sr)","Double perovskites Sr2FeOsO6 and Ca2FeOsO6 show puzzling magnetic properties,
the former a low-temperature antiferromagnet while the later a high-temperature
insulating ferrimagnet. Here, in order to understand the underlying mechanism,
we have investigated the frustrated magnetism of A2FeOsO6 by employing density
functional theory and maximally-localized Wannier functions. We find that
lattice distortion enhances the antiferromagnetic nearest-neighboring Fe-O-Os
interaction but weakens the antiferromagnetic interactions through the
Os-O-O-Os and Fe-O-Os-O-Fe paths, which is responsible for the magnetic
transition from the low-temperature antiferromagnetism to the high-temperature
ferrimagnetism with the decrease of the radius of the A2+ ions. We also discuss
the 5d3-3d5 superexchange and propose such superexchange is intrinsically
antiferromagnetic instead of the expected ferromagnetic. Our work illustrate
that the magnetic frustration can be effectively relieved by lattice
distortion, which provides another dimension to tune the complex magnetism in
other 3d-5d (4d) double perovskites.",1410.4280v1
2014-10-16,Vigorous thermal excitations in a double-tetrahedral chain of localized Ising spins and mobile electrons mimic a temperature-driven first-order phase transition,"A hybrid spin-electron system defined on one-dimensional double-tetrahedral
chain, in which the localized Ising spin regularly alternates with two mobile
electrons delocalized over a triangular plaquette, is exactly solved with the
help of generalized decoration-iteration transformation. It is shown that a
macroscopic degeneracy of ferromagnetic and ferrimagnetic ground states arising
from chiral degrees of freedom of the mobile electrons cannot be lifted by a
magnetic field in contrast to a macroscopic degeneracy of the frustrated ground
state, which appears owing to a kinetically-driven frustration of the localized
Ising spins. An anomalous behavior of all basic thermodynamic quantities can be
observed on account of massive thermal excitations, which mimic a
temperature-driven first-order phase transition from the non-degenerate
frustrated state to the highly degenerate ferrimagnetic state at non-zero
magnetic fields. A substantial difference in the respective degeneracies is
responsible for an immense low-temperature peak of the specific heat and very
abrupt (almost discontinuous) thermal variations of the entropy and sublattice
magnetizations.",1410.4313v2
2014-10-31,Enhanced ferrimagnetism in auxetic NiFe2O4 in the crossover to the ultrathin film limit,"We investigate the sensitive interplay between magnetic, electronic and
structural properties in the ferrimagnetic oxide NiFe2O4. Emphasis is placed on
the impact of reduced dimensionality in the crossover from bulk-like to
ultrathin films. We observed an enhanced saturation magnetization $M_S$ for
ultrathin NiFe2O4 films on Nb-SrTiO3 (001) substrates that co-occurs with a
reduced out-of-plane lattice constant under compressive in-plane epitaxial
strain. We found a bulk-like cationic coordination of the inverse spinel
lattice independent of the NiFe2O4 film thickness -- thus ruling out a cationic
inversion that nominally could account for an enhanced $M_S$. Our study instead
uncovers a reduction of the unit cell volume, i.e. an auxetic behavior in
ultrathin NiFe2O4 films, which may result in an enhanced magnetic exchange
caused by an increased interatomic electronic localization.",1410.8782v1
2014-12-01,All-optical magnetization switching in ferrimagnetic alloys: deterministic vs thermally activated dynamics,"Using photo-emission electron microscopy with X-ray magnetic circular
dichroism as a contrast mechanism, new insights into the all-optical
magnetization switching (AOS) phenomenon in GdFe based rare-earth transition
metal ferrimagnetic alloys are provided. From a sequence of static images taken
after single linearly polarized laser pulse excitation, the repeatability of
AOS can be measured with a correlation coefficient. It is found that low
coercivity enables thermally activated domain wall motion, limiting in turn the
repeatability of the switching. Time-resolved measurement of the magnetization
dynamics reveal that while AOS occurs below and above the magnetization
compensation temperature $T_\text{M}$, it is not observed in GdFe samples where
$T_\text{M}$ is absent. Finally, AOS is experimentally demonstrated against an
applied magnetic field of up to 180 mT.",1412.0396v1
2015-01-01,A hybrid-exchange density-functional theory study of the electronic structure of $\mathrm{MnV}_2\mathrm{O}_4$: Exotic orbital ordering in the cubic structure,"The electronic structures of the cubic and tetragonal
$\mathrm{MnV}_2\mathrm{O}_4$ have been studied by using hybrid-exchange density
functional theory. The computed electronic structure of the tetragonal phase
shows an anti-ferro orbital ordering on V sites and a ferrimagnetic ground
state (the spins on V and Mn are anti-aligned). These results are in a good
agreement with the previous theoretical result obtained from the local-density
approximation+$U$ methods [S. Sarkar, et. al., Phys. Rev. Lett. 102, 216405
(2009)]. Moreover, the electronic structure, especially the projected density
of states of the cubic phase has been predicted with a good agreement with the
recent soft x-ray spectroscopy experiment. Similar to the tetragonal phase, the
spins on V and Mn in the cubic structure favour a ferrimagnetic configuration.
Most interesting is that the computed charge densities of the spin-carrying
orbitals on V in the cubic phase show an exotic orbital ordering, i.e., a
ferro-orbital ordering along [110] but an anti-ferro-orbital ordering along
[$\overline{1}$10].",1501.00322v4
2015-02-19,"Ferrimagnetism in 2D networks of porphyrin-X and -XO (X=Sc,...,Zn) with acetylene bridges","Magnetism in 2D networks of the acetylene-bridged transition metal porphyrins
M(P)-2(C-C)-2 (denoted P-TM), and oxo-TM-porphyrins OM(P)-2(C-C)-2 (denoted
P-TMO), is studied with the density functional theory (DFT) and the
self-interaction corrected pseudopotential scheme (pSIC). Addition of oxygen
lowers magnetism of P-TMO with respect to the corresponding P-TM for most of
the first-half $3d$-row TMs. In contrast, binding O with the second-half
$3d$-row TMs or Sc increases the magnetic moments. Ferrimagnetism is found for
the porphyrin networks with the TMs from V to Co and also for these cases with
oxygen. This is a long-range effect of the delocalized spin-polarization,
extended even to the acetylene bridges.",1502.05738v3
2015-02-20,Classical dipoles on the kagome lattice,"Motivated by recent developments in magnetic materials, frustrated nanoarrays
and cold atomic systems, we investigate the behaviour of dipolar spins on the
frustrated two-dimensional kagome lattice. By combining the Luttinger-Tisza
approach, numerical energy minimization, spin-wave analysis and parallel
tempering Monte-Carlo, we study long-range ordering and finite-temperature
phase transitions for a Hamiltonian containing both dipolar and
nearest-neighbor interactions. For both weak and moderate dipolar interactions,
the system enters a three-sublattice long-range ordered state, with each
triangle having vanishing dipole and quadrupole moments; while for dominating
dipolar interactions we uncover ferrimagnetic three-sublattice order. These are
also the ground states for XY spins. We discuss excitations of, as well as
phase transitions into, these states. We find behaviour consistent with Ising
criticality for the 120-degree state, while the ferrimagnetic state appears to
be associated with drifting exponents. The celebrated flat band of zero-energy
excitations of the kagome nearest-neighbour Heisenberg model is lifted to
finite energies but acquires only minimal dispersion as dipolar interactions
are added.",1502.05960v1
2015-03-26,Enhancing Magnetic Ordering in Cr-doped Bi2Se3 using High-TC Ferrimagnetic Insulator,"We report a study of enhancing the magnetic ordering in a model magnetically
doped topological insulator (TI), Bi2-xCrxSe3, via the proximity effect using a
high-TC ferrimagnetic insulator Y3Fe5O12. The FMI provides the TI with a source
of exchange interaction yet without removing the nontrivial surface state. By
performing the elemental specific X-ray magnetic circular dichroism (XMCD)
measurements, we have unequivocally observed an enhanced TC of 50 K in this
magnetically doped TI/FMI heterostructure. We have also found a larger (6.6 nm
at 30 K) but faster decreasing (by 80% from 30 K to 50 K) penetration depth
compared to that of diluted ferromagnetic semiconductors (DMSs), which could
indicate a novel mechanism for the interaction between FMIs and the nontrivial
TIs surface.",1503.07893v1
2015-05-04,Magnetic phase diagram of the Hubbard model in the Lieb lattice,"We study the mean-field phase diagram of the repulsive Hubbard model in the
Lieb lattice. Far from half-filling, the most stable phases are paramagnetism
for low on-site interaction $U/t$ and ferromagnetism for high $U/t$, as in the
case of the mean-field phase diagram of the square lattice Hubbard model
obtained by Dzierzawa [\onlinecite{Dzierzawa1992}]. At half-filling, the ground
state was found to be ferrimagnetic [a $(\pi,\pi)$ spiral phase], in agreement
with a theorem by Lieb [\onlinecite{Lieb1989}]. The total magnetization
approaches Lieb's prediction as $U/t$ becomes large. As we move away from
half-filling, this ferrimagnetic phase becomes a $(q_1,q_1)$ spiral phase with
$q_1 \approx \pi$ and then undergoes a series of first-order phase transitions,
$(q_1,q_1) \rightarrow (q_1,q_2) \rightarrow (q_1,0)$, with $q_2 \approx
\pi/2$, before becoming ferromagnetic at large $U/t$ or paramagnetic at low
$U/t$.",1505.00578v1
2015-06-04,Low-moment ferrimagnetic phase of the Heusler compound Cr2CoAl,"Synthesizing half-metallic fully-compensated ferrimagnets that form in the
inverse Heusler phase could lead to superior spintronic devices. These
materials would have high spin polarization at room temperature with very
little fringing magnetic fields. Previous theoretical studies indicated that
Cr2CoAl should form in a stable inverse Heusler lattice due to its low
activation energy. Here, stoichiometric Cr2CoAl samples were arc-melted and
annealed at varying temperatures, followed by studies of their structural and
magnetic properties. High-resolution synchrotron X-ray diffraction revealed a
chemically ordered Heusler phase in addition to CoAl and Cr phases. Soft X-ray
magnetic circular dichroism revealed that the Cr and Co magnetic moments are
antiferromagnetically oriented leading to the observed low magnetic moment in
Cr2CoAl.",1506.01738v1
2015-07-24,Unveiling hidden ferrimagnetism and giant magnetoelectricity in polar magnet Fe2Mo3O8,"Magnetoelectric (ME) effect is recognized for its utility for low-power
electronic devices.Largest ME coefficients are often associated with phase
transitions in which ferroelectricity is induced by magnetic order.
Unfortunately, in these systems, large ME response is revealed only upon
elaborate poling procedures. These procedures may become unnecessary in
single-polar-domain crystals of polar magnets. Here we report giant ME effects
in a polar magnet Fe2Mo3O8 at temperatures as high as 60 K.Polarization jumps
of 0.3 {\mu}C/cm2, and repeated mutual control of ferroelectric and magnetic
moments with differential ME coefficients on the order of 10$^4$ ps/m are
achieved.Importantly, no electric or magnetic poling is needed, as necessary
for applications.The sign of the ME coefficients can be switched by changing
the applied ""bias"" magnetic field. The observed effects are associated with a
hidden ferrimagnetic order unveiled by application of a magnetic field.",1507.06847v1
2015-09-02,Effect of Chemical Pressure on High Temperature Ferrimagnetic Double Perovskites Sr2CrOsO6 and Ca2CrOsO6,"The ordered double perovskites Sr2CrOsO6 and Ca2CrOsO6 have been synthesized
and characterized with neutron powder diffraction, electrical transport
measurements, and high field magnetization experiments. Sr2CrOsO6 and Ca2CrOsO6
crystallize with R-3 and P21/n space group symmetry, respectively. Both
materials are found to be ferrimagnetic insulators with saturation
magnetizations near 0.2 {\mu}B. Sr2CrOsO6 orders at 660 K, showing
non-monotonic magnetization temperature dependence, while Ca2CrOsO6 orders at
490 K and does not show non-monotonic behavior. Evidence for a theoretically
predicted canted magnetic structure in Sr2CrOsO6 is sought and not found.",1509.00901v1
2015-09-14,Ground-state phases of rung-alternated spin-1/2 Heisenberg ladder,"The ground-state phase diagram of Heisenberg spin-1/2 system on a two-leg
ladder with rung alternation is studied by combining analytical approaches with
numerical simulations. For the case of ferromagnetic leg exchanges a unique
ferrimagnetic ground state emerges, whereas for the case of antiferromagnetic
leg exchanges several different ground states are stabilized depending on the
ratio between exchanges along legs and rungs. For the more general case of a
honeycomb-ladder model for the case of ferromagnetic leg exchanges besides
usual rung-singlet and saturated ferromagnetic states we obtain a ferrimagnetic
Luttinger liquid phase with both linear and quadratic low energy dispersions
and ground state magnetization continuously changing with system parameters.
For the case of antiferromagnetic exchanges along legs, different dimerized
states including states with additional topological order are suggested to be
realized.",1509.04062v1
2015-10-19,Critical behavior of a triangular lattice Ising AF/FM bilayer,"We study a bilayer Ising spin system consisting of antiferromagnetic (AF) and
ferromagnetic (FM) triangular planes, coupled by ferromagnetic exchange
interaction, by standard Monte Carlo and parallel tempering methods. The AF/FM
bilayer is found to display the critical behavior completely different from
both the single FM and AF constituents as well as the FM/FM and AF/AF bilayers.
Namely, by finite-size scaling (FSS) analysis we identify at the same
temperature a standard Ising transition from the paramagnetic to FM state in
the FM plane that induces a ferrimagnetic state with a finite net magnetic
moment in the AF plane. At lower temperatures there is another phase
transition, that takes place only in the AF plane, to different ferrimagnetic
state with spins on two sublattices pointing parallel and on one sublattice
antiparallel to the spins on the FM plane. FSS indicates that the corresponding
critical exponents are close to the two-dimensional three-state ferromagnetic
Potts model values.",1510.05383v1
2015-11-25,Designing a fully-compensated half-metallic ferrimagnet,"Recent experimental work on Mn2RuxGa demonstrates its potential as a
compensated ferrimagnetic half-metal (CFHM).Here we present a set of
high-throughput ab initio density functional theory calculations and detailed
experimental characterisation, that enable us to correctly describe the nominal
Mn2RuxGa thin films, in particular with regard to site-disorder and defects. We
then construct models that accurately capture all the key features of the
Mn-Ru-Ga system, including magnetic compensation and the spin gap at the Fermi
level. We find that electronic doping is neccessary, which is achieved with a
Mn/Ga ratio smaller than two. Our study shows how composition and
substrate-induced biaxial strain can be combined to design the first
room-temperature CFHM.",1511.07923v2
2016-03-18,First-principles study of ferroelectricity induced by p-d hybridization in ferrimagnetic NiFe2O4,"We investigate the ferrimagnetism and ferroelectricity of bulk NiFe$_2$O$_4$
with tetragonal $P4_122$ ~symmetry by means of density functional calculations
using generalized gradient approximation + Hubbard $U$ approach. Special
attention is paid to finding the most energetically favorable configuration on
magnetic ordering and further calculating the reliable spontaneous electric
polarization. With the fully optimized crystalline structure of the most stable
configuration, the spontaneous polarization is obtained to be 23 $\mu$C/cm$^2$
along the z direction, which originates from the hybridization between the 3d
states of the Fe$^{3+}$ cation and the 2p states of oxygen induced by
Jahn-Teller effect.",1603.05974v2
2016-03-21,Ferrimagnetic ordering and spin entropy of field-dependent intermediate spins in Na0.82CoO2,"The peculiar field-dependent magnetism of Na0.82CoO2 has been investigated
through an analysis of its DC and AC spin susceptibilities. To account for the
easily activated narrow b2g-a1g gap of the crystal field for Co in the cobalt
oxide layer, the spin-state transition of Co3+ (3d6) between the low spin (LS)
state b2g^2-a1g^0 of S=0 and the intermediate spin (IS) state b2g^1-a1g^1 of
S=1 is thus seen as thermally activated and exhibits a Boltzmann distribution.
The IS state of Co3+ within each sqrt(13a) hexagonal superlattice formed by the
S=1/2 state of the Co4+ ions appears randomly within each supercell and shows
significant temperature and field dependence. The magnetic field is found to
assist in pinning down the thermally activated state of Co3+ and swings the
Boltzmann distribution weight toward a higher fraction of the IS state. The
field dependence of the in-plane magnetic moment from the added number of S=1
spins is used to explain the origin of A-type antiferromagnetic (AF) ordering,
particularly that the ferromagnetic (FM)-like behavior below TN at low field is
actually a ferrimagnetic IS spin ordering of Co3+.",1603.06451v1
2016-04-05,Micromagnetic simulation of exchange coupled ferri-/ferromagnetic composite in bit patterned media,"Ferri-/ferromagnetic exchange coupled composites are promising candidates for
bit patterned media because of the ability to control the magnetic properties
of the ferrimagnet by its composition. A micromagnetic model for the bilayer
system is presented where we also incorporate the microstructural features of
both layers. Micromagnetic finite element simulations are performed to
investigate the magnetization reversal behaviour of such media. By adding the
exchange coupled ferrimagnet to the ferromagnet, the switching field could be
reduced by up to $40\,\%$ and also the switching field distribution is
narrowed. To reach these significant improvements, an interface exchange
coupling strength of $2\,\mathrm{mJ/m^2}$ is required.",1604.01180v1
2016-04-17,Interface electronic structure at the topological insulator - ferrimagnetic insulator junction,"An interface electron state at the junction between a three-dimensional
topological insulator (TI) film of Bi2Se3 and a ferrimagnetic insulator film of
Y3Fe5O12 (YIG) was investigated by measurements of angle-resolved photoelectron
spectroscopy and X-ray absorption magnetic circular dichroism (XMCD). The
surface state of the Bi2Se3 film was directly observed and localized 3d spin
states of the Fe3+ state in the YIG film were confirmed. The proximity effect
is likely described in terms of the exchange interaction between the localized
Fe 3d electrons in the YIG film and delocalized electrons of the surface and
bulk states in the Bi2Se3 film. The Curie temperature (TC) may be increased by
reducing the amount of the interface Fe2+ ions with opposite spin direction
observable as a pre-edge in the XMCD spectra.",1604.04869v1
2016-06-10,Effect of Gd/Nd doping on the magnetic properties of PrMnO3,"A study on temperature dependent magnetic properties of single phase
orthorhombic perovskites system associated with space group Pbnm compounds
Pr1-x(Gd/Nd)xMnO3 (x=0.3, 0.5, 0.7) was carried out. A magnetization reversal
is observed below the Neel temperature (TN), in DC magnetization measurements
(at 50 Oe) in the doped compounds. This may be due to the antiparallel coupling
between the two magnetic sublattices (|Pr+Gd/Nd | and Mn). With lowering of
temperature, the |Pr+ Gd/Nd|) ions begin to polarize under the negative
internal field due to canted moment of Mn moments. The hysteresis plot taken at
50K shows a ferrimagnetic characteristic and the presence of spin canting of
ions in the magnetic sublattices. Arrott plot indicates field induced second
order paramagnetic to ferrimagnetic (PM-FiM) phase transition in this system.",1606.03274v1
2016-09-20,A coupled spin-electron diamond chain with different Landé g-factors of localized Ising spins and mobile electrons,"A coupled spin-electron diamond chain with localized Ising spins placed on
its nodal sites and mobile electrons delocalized over interstitial sites is
explored in a magnetic field taking into account the difference between Land\'e
g-factors of the localized spins and mobile electrons. The ground-state phase
diagram is constituted by two classical ferrimagnetic phases, the quantum
unsaturated paramagnetic phase and the saturated paramagnetic phase. Both
classical ferrimagnetic phases as well as the unsaturated paramagnetic phase
are reflected in a low-temperature magnetization curve as intermediate
magnetization plateaus. The unsaturated paramagnetic phase is quantum in its
character as evidenced by the fermionic concurrence calculated for a pair of
the mobile electrons hopping in between the interstitial sites. It is shown
that the magnetic field can under certain conditions induce a quantum
entanglement above the disentangled ground state.",1609.06072v2
2016-10-11,Semiclassical analysis of a magnetization plateau in a 2D frustrated ferrimagnet,"We use a semiclassical large-$S$ expansion to study a plateau at $1/3$
saturation in the magnetization curve of a frustrated ferrimagnet on a
spatially anisotropic kagom\'{e} lattice. The spins have both ferromagnetic and
antiferromagnetic nearest-neighbor Heisenberg couplings, and a frustrating
next-nearest-neighbor coupling in one lattice direction. The magnetization
plateau appears at the classical level for a certain range of couplings, and
quantum fluctuations significantly broaden it at both ends. Near the region of
the phase diagram where the classical plateau destabilizes, we find an exotic
""chiral liquid"" phase that preserves translational and $U(1)$ spin symmetry, in
which bound pairs of magnons with opposite spins are condensed. We show how
this state is obtained naturally from a relativistic field theory formulation.
We comment on the relevance of the model to the material
$\text{Cu}_3\text{V}_2\text{O}_7\text{(OH)}_2 \cdot 2\text{H}_2\text{O}$
(volborthite).",1610.03135v3
2018-02-01,Stability of Room Temperature Compensated Half-Metallicity in Cr-based Inverse-Heusler Compounds,"Using three correlated band approaches, namely the conventional band approach
plus on-site Coulomb repulsion $U$, the modified Becke-Johnson functional, and
hybrid functional, we have investigated inverse-Heusler ferrimagnets
Cr$_2$Co${\cal Z}$ (${\cal Z}$=Al, Ga, In). These approaches commonly indicate
that the Cr$_2$CoAl synthesized recently is a precise compensated half-metal
(CHM), whereas Cr$_2$CoGa and Cr$_2$CoIn are ferrimagnets with a small moment.
This is also confirmed by the fixed spin moment approach. Analysis of the Bader
charge decomposition and the radial charge densities indicates that this
contrast is due to chemical differences among the ${\cal Z}$ ions.
Additionally, in Cr$_2$CoAl, changing the volume by $\pm$ 5% or the ratio of
$c/a$ by $\pm$ 2% does not alter the CHM state, suggesting that this state is
robust even under application of moderate pressure or strain. Considering the
observed high Curie temperature of 750 K, our results suggest that Cr$_2$CoAl
is a promising candidate for robust high $T_C$ CHMs. Furthermore, the
electronic structure of the CHM Cr$_2$CoAl is discussed.",1802.00125v2
2018-02-14,Moderate Magnetic Field Induced Large Exchange Bias Effect in Ferrimagnetic 314-Sr3YCo4O10.5 Material,"Herein, we report the appearance of a large exchange bias (EB) effect in a
moderate cooling field (cooling field, H$_{FC}$ = 1 kOe) for the
314-Sr3YCo4O10.5 material. The exchange bias has started to appear near room
temperature and reaches a maximum value of 5.5 kOe at 4 K. The existence of
ferrimagnetic clusters in the compensated host in this layered structure
originates the large exchange anisotropy. Remarkably, the observed value of
moderate magnetic field induced exchange bias field is extremely large in
comparison with material systems which are recognized to exhibit giant exchange
bias effect. In combination with the feasibility of room temperature
application, the appearance of large exchange bias in a moderate cooling field
exemplifying the present material system as a promising class of compounds for
designing coherent magnetic materials with huge exchange bias in low/moderate
magnetic field.",1802.05194v1
2018-04-03,Phase diagram of the Hubbard-Kondo lattice model from variational cluster approximation,"The interplay between the Kondo effect and magnetic ordering driven by the
Ruderman-Kittel-Kasuya-Yosida interaction is studied within the two-dimensional
Hubbard-Kondo lattice model. In addition to the antiferromagnetic exchange
interaction, $J_\perp$, between the localized and the conduction electrons,
this model also contains the local repulsion, $U$, between the conduction
electrons. We use variational cluster approximation to investigate the
competition between the antiferromagnetic phase, the Kondo singlet phase, and a
ferrimagnetic phase on square lattice. At half-filling, the N\'eel
antiferromagnetic phase dominates from small to moderate $J_\perp$ and
$UJ_\perp$, and the Kondo singlet elsewhere. Sufficiently away from
half-filling, the antiferromagnetic phase first gives way to a ferrimagnetic
phase (in which the localized spins order ferromagnetically, and the conduction
electrons do likewise, but the two mutually align antiferromagnetically), and
then to the Kondo singlet phase.",1804.00917v1
2018-11-21,Squeezed states of magnons and phonons in cavity magnomechanics,"We show how to create quantum squeezed states of magnons and phonons in a
cavity magnomechanical system. The magnons are embodied by a collective motion
of a large number of spins in a macroscopic ferrimagnet, and couple to cavity
microwave photons and phonons (vibrational modes of the ferrimagnet) via the
magnetic dipole interaction and magnetostrictive interaction, respectively. The
cavity is driven by a weak squeezed vacuum field generated by a flux-driven
Josephson parametric amplifier, which is essential to get squeezed states of
the magnons and phonons. We show that the magnons can be prepared in a squeezed
state via the cavity-magnon beamsplitter interaction, and by further driving
the magnon mode with a strong red-detuned microwave field, the phonons are
squeezed. We show optimal parameter regimes for obtaining large squeezing of
the magnons and phonons, which are robust against temperature and could be
realized with experimentally reachable parameters.",1811.09668v4
2019-05-16,Transition between canted antiferromagnetic and spin-polarized ferromagnetic quantum Hall states in graphene on a ferrimagnetic insulator,"In the quantum Hall regime of graphene, antiferromagnetic and spin-polarized
ferromagnetic states at the zeroth Landau level compete, leading to a canted
antiferromagnetic state depending on the direction and magnitude of an applied
magnetic field. Here, we investigate this transition at 2.7 K in graphene Hall
bars that are proximity coupled to the ferrimagnetic insulator
Y$_{3}$Fe$_{5}$O$_{12}$. From nonlocal transport measurements, we demonstrate
an induced magnetic exchange field in graphene, which lowers the magnetic field
required to modulate the magnetic state in graphene. These results show that a
magnetic proximity effect in graphene is an important ingredient for the
development of two-dimensional materials in which it is desirable for ordered
states of matter to be tunable with relatively small applied magnetic fields (>
6 T).",1905.06866v2
2020-07-01,Microscopic origin of magnetization reversal in exchange-coupled ferro-/ferrimagnetic bilayers,"In this study, the magnetic reversal process of exchange-coupled bilayer
systems, consisting of a ferrimagnetic TbFeCo alloy layer and a ferromagnetic
[Co/Ni/Pt]N multilayer, was investigated. In particular, minor loop studies,
probing solely the reversal characteristics of the softer ferromagnetic layer,
reveal two distinct reversal mechanisms, which depend strongly on the thickness
of the ferromagnetic layer. For thick layers, irreversible switching of the
macroscopic minor loop is observed. The underlying microscopic origin of this
reversal process was studied in detail by high-resolution magnetic force
microscopy, showing that the reversal is triggered by in-plane domain walls
propagating through the ferromagnetic layer. In contrast, thin ferromagnetic
layers show a hysteresis-free reversal, which is nucleation-dominated due to
grain-to-grain variations in magnetic anisotropy of the Co/Ni/Pt multilayer and
an inhomogeneous exchange coupling with the magnetically hard TbFeCo layer, as
confirmed by micromagnetic simulations.",2007.00333v1
2020-07-07,Anisotropy induced spin re-orientation in chemically-modulated amorphous ferrimagnetic films,"The ability to tune the competition between the in-plane and out-of-plane
orientation of magnetization provides a means to construct thermal sensors with
a sharp spin re-orientation transition at specific temperatures. We have
observed such a tuneable, temperature driven spin re-orientation in
structurally amorphous, ferrimagnetic rare earth-transition metal (RE-TM) alloy
thin films using scanning transmission X-ray microscopy (STXM) and magnetic
measurements. The nature of the spin re-orientation transition in FeGd can be
fully explained by a non-equilibrium, nanoscale modulation of the chemical
composition of the films. This modulation leads to a magnetic domain pattern of
nanoscale speckles superimposed on a background of in-plane domains that form
Laudau configurations in micron-scale patterned elements. It is this speckle
magnetic structure that gives rise to a sharp two step-reversal mechanism that
is temperature dependent. The possibility to balance competing anisotropies
through the temperature opens opportunities to create and manipulate
topological spin textures.",2007.03657v1
2020-07-09,Fe3Se4: A Possible Ferrimagnetic Half-Metal?,"Half-metallic ferromagnets show 100% spin-polarization at the Fermi level and
are ideal candidates for spintronic applications. Despite the extensive
research in the field, very few materials have been discovered so far. Here we
present results of electronic band structure calculations based on density
functional theory and extensive physical-property measurements for Fe3Se4
revealing signatures of half-metallicity. The spin-polarized electronic band
structure calculations predict half-metallic ferrimagnetism for Fe3Se4. The
electrical resistivity follows exponentially suppressed electron-magnon
scattering mechanism in the low-temperature regime and show a magnetoresistance
effect that changes the sign from negative to positive with decreasing
temperature around 100 K. Other intriguing observations include the anomalous
behavior of Hall resistance below 100 K and an anomalous Hall coefficient that
roughly follows the \r{ho}2 behavior.",2007.04736v1
2020-07-15,Spin-orbit coupling in single layer ferrimagnets: direct observation of spin-orbit torques and chiral spin textures,"We demonstrate that effects of spin-orbit coupling and inversion asymmetry
exist in a single GdFeCo ferrimagnetic layer, even without a heavy metal
interface. We use electric transport measurements to quantify the spin-orbit
torques. We measure the Dzyaloshinskii-Moriya interaction using Brillouin light
scattering measurement technique, and we observe the resulting chiral magnetic
textures using x-ray PEEM microscopy. We attribute these effects to a
composition variation along the thickness, that we observed by scanning
transmission electron microscopy. We show that these effects can be optimized
by varying the GdFeCo thickness or by combining them with interfacial effects.",2007.07569v2
2020-07-28,Anomalous Hall Effect in Kagome Ferrimagnet GdMn$_6$Sn$_6$,"We present magnetotransport data on the ferrimagnet GdMn$_6$Sn$_6$. From the
temperature dependent data we are able to extract a large instrinsic
contribution to the anomalous Hall effect $\sigma_{xz}^{int} \sim$ 32
$\Omega^{-1}cm^{-1}$ and $\sigma_{xy}^{int} \sim$ 223 $\Omega^{-1}cm^{-1}$,
which is comparable to values found in other systems also containing kagome
nets of transition metals. From our transport anisotropy, as well as our
density functional theory calculations, we argue that the system is
electronically best described as a three dimensional system. Thus, we show that
reduced dimensionality is not a strong requirement for obtaining large Berry
phase contributions to transport properties. In addition, the coexistence of
rare-earth and transition metal magnetism makes the hexagonal MgFe$_6$Ge$_6$
structure type a promising system to tune the electronic and magnetic
properties in future studies.",2007.14436v1
2013-08-05,Controlling the Polarity of the Transient Ferromagnetic-Like State in Ferrimagnets,"After the application of an ultrashort laser pulse, the antiferromagnetic
alignment in rare earth-transition metal alloys can temporarily become
ferromagnetic with the rare-earth polarity.
  Proposed models merely describe this effect, without showing the route for
its manipulation. Here we use extensive atomistic spin model simulations and
micromagnetic theory for ferrimagnets at elevated temperatures to predict that
the polarity of this transient ferromagnetic-like state can be controlled by
initial temperature. We show that this arises because the magnetic response of
each lattice has a different temperature dependence, at low temperatures the
transition metal responds faster than the rare earth, while at high
temperatures this role is interchanged. Our findings contribute to the physical
understanding and control of this state and thus open new perspectives for its
use in ultrafast magnetic devices.",1308.0993v2
2016-11-08,Thermal and Magnetic Properties of Nanostructured Ferrimagnetic Composites with Graphene - Graphite Fillers,"We report the results of an experimental study of thermal and magnetic
properties of nanostructured ferrimagnetic iron oxide composites with graphene
and graphite fillers synthesized via the current activated pressure assisted
densification. The thermal conductivity was measured using the laser-flash and
transient plane source techniques. It was demonstrated that addition of 5 wt. %
of equal mixture of graphene and graphite flakes to the composite results in a
factor of x2.6 enhancement of the thermal conductivity without significant
degradation of the saturation magnetization. The microscopy and spectroscopic
characterization reveal that sp2 carbon fillers preserve their crystal
structure and morphology during the composite processing. The strong increase
in the thermal conductivity was attributed to the excellent phonon heat
conduction properties of graphene and graphite. The results are important for
energy and electronic applications of the nanostructured permanent magnets.",1611.02359v1
2016-11-29,Diagonal magnetoelectric susceptibility and effect of Fe-doping in a polar ferrimagnet Mn2Mo3O8,"We investigate a large variation in a diagonal component of the linear
magnetoelectric (ME) susceptibility in a polar ferrimagnet Mn2Mo3O8 while
changing the magnetic-ion site from orbital-quenched Mn2+ to Fe2+ with strong
uniaxial anisotropy. In Mn2Mo3O8, the linear ME susceptibility is dominated by
the non-relativistic exchange striction mechanism, showing a positive value at
low temperature and a critical behavior toward negative divergence around the
transition temperature. This negative peak value becomes four times larger when
50% of Mn2+ ions are replaced with Fe2+ ion, highlighting the beneficial
perspective of the compositionally-tunable ME effect. As the doped Fe increases
in fraction, gradual negative shift of the ME coefficient is observed around
the lowest temperature, which manifests relativistic single-site origin of the
ME susceptibility. Further doping with x >= 75% in (Mn1-xFex)2Mo3O8, the ME
coefficient becomes negative in the entire temperature region. Such a
composition dependence can be explained in terms of the chemical preference for
the two types of magnetic sites of Mn/Fe ions. The present study demonstrates
the large tunability of ME effect by substituting the magnetic ion with the
primary structural/magnetic characters kept intact.",1611.09458v2
2017-01-31,Tunable magnon-photon coupling in a compensating ferrimagnet - from weak to strong coupling,"We experimentally study the magnon-photon coupling in a system consitsing of
the compensating ferrimagnet gadolinium iron garnet (GdIG) and a
three-dimensional microwave cavity. The temperature is varied in order to tune
the GdIG magnetization and to observe the transition from the weak coupling
regime to the strong coupling regime. By measuring and modelling the complex
reflection parameter of the system the effective coupling rate g eff and the
magnetization M eff of the sample are extracted. Comparing g eff with the
magnon and the cavity decay rate we conclude that the strong coupling regime is
easily accessible using GdIG. We show that the effective coupling strength
follows the predicted square root dependence on the magnetization.",1701.08969v3
2017-01-31,Ferrimagnetic and antiferromagnetic phase in bilayer graphene nanoflake controlled with external electric fields,"The paper presents a computational study of the ground-state magnetic phases
of a selected bilayer graphene nanoflake in external electric field and
magnetic field. The electric field has parallel and perpendicular component
while the magnetic field is oriented in plane. The system consists of two
rectangular layers having armchair edges and zigzag terminations with Bernal
stacking. The theoretical model is based on a tight binding Hamiltonian with
Hubbard term. The magnetic phase diagram involving the total spin is
constructed, showing the stability areas of phases with total spin values equal
to 0 and 1. A significant stability range of antiferromagnetic, layer-like
arrangements is found and extensively discussed. The possibility of switching
between nonmagnetic, antiferromagnetic and ferrimagnetic phases with both
components of external electric field is demonstrated, being a manifestation of
a magnetoelectric effect. The influence of magnetic field on the phase diagrams
is analysed.",1701.09128v2
2014-05-09,Magnetic excitations and anomalous spin wave broadening in multiferroic FeV2O4,"We report on the different roles of two orbital-active Fe$^{2+}$ at the A
site and V$^{3+}$ at the B site in the magnetic excitations and on the
anomalous spin wave broadening in FeV$_{2}$O$_{4}$. FeV$_{2}$O$_{4}$ exhibits
three structural transitions and successive paramagnetic (PM)-collinear
ferrimagnetic (CFI)-noncollinear ferrimagnetic (NCFI) transitions. The
high-temperature tetragonal/PM -orthorhombic/CFI transition is accompanied by
the appearance of an energy gap with a high magnitude in the magnetic
excitations due to strong spin-orbit coupling induced anisotropy at the
Fe$^{2+}$ site. While there is no measurable increase in the energy gap from
the orbital ordering of V$^{3+}$ at the orthorhombic/CFI-tetragonal/NCFI
transition, anomalous spin wave broadening is observed in the orthorhombic/CFI
state due to V$^{3+}$ spin fluctuations at the B site. The spin wave broadening
is also observed at the zone boundary without softening, which is discussed in
terms of magnon-phonon coupling.",1405.2272v2
2014-06-12,Ferrimagnetism in the double perovskite Ca2FeOsO6: a density functional study,"Using density functional calculations, we find that the newly synthesized
Ca$_2$FeOsO$_6$ has the high-spin Fe$^{3+}$ ($3d^5$)-Os$^{5+}$ ($5d^3$) state.
The octahedral Os$^{5+}$ ion has a large intrinsic exchange splitting, and its
$t_{2g\uparrow}^3$ configuration makes the spin-orbit coupling ineffective.
Moreover, there is a strong antiferromagnetic (AF) coupling between the
neighboring Fe$^{3+}$ ($S$ = 5/2) and Os$^{5+}$ ($S$ = -3/2), but the AF
couplings within both the fcc Fe$^{3+}$ and Os$^{5+}$ sublattices are one order
of magnitude weaker. Therefore, a magnetic frustration is suppressed and a
stable ferrimagnetic (FiM) ground state appears. This FiM order is due to the
virtual hopping of the $t_{2g}$ electrons from Os$^{5+}$ ($t_{2g\downarrow}^3$)
to Fe$^{3+}$ ($t_{2g\uparrow}^3e_{g\uparrow}^2$). However, if the experimental
bended Fe$^{3+}$-O$^{2-}$-Os$^{5+}$ exchange path gets straight, the $e_g$
hopping from Fe$^{3+}$ ($t_{2g\uparrow}^3e_{g\uparrow}^2$) to Os$^{5+}$
($t_{2g\uparrow}^3$) would be facilitated and then a ferromagnetic (FM)
coupling would occur.",1406.3101v1
2014-06-27,Spin-phonon coupling in BaFe12O19 M-type hexaferrite,"The spin-phonon coupling in magnetic materials is due to the modulation of
the exchange integral by lattice vibrations. BaFe12O19 M-type hexaferrite,
which is the most used magnetic material as permanent magnet, transforms into
ferromagnet at high temperatures, but no spin-phonon coupling was previously
observed at this transition. In this letter, we investigated the
temperature-dependent Raman spectra of polycrystalline BaFe12O19 M-type
hexaferrite from room temperature up to 780 K to probe spin-phonon coupling at
the ferrimagnetic transition. An anomaly was observed in the position of the
phonon attributed to the Fe(4)O6 octahedra, evidencing the presence of a
spin-phonon coupling in BaM in the ferrimagnetic transition at 720 K. The
results also confirmed the spin-phonon coupling is different for each phonon
even when they couple with the same spin configuration.",1406.7334v2
2015-12-18,Exchange Bias and Bistable Magneto-Resistance States in Amorphous TbFeCo thin Films,"Amorphous TbFeCo thin films sputter deposited at room temperature on
thermally oxidized Si substrate are found to exhibit strong perpendicular
magnetic anisotropy (PMA). Atom probe tomography (APT), scanning transmission
electron microscopy (STEM), and energy dispersive spectroscopy (EDS) mapping
have revealed two nanoscale amorphous phases with different Tb atomic
percentages distributed within the amorphous film. Exchange bias accompanied by
bistable magneto-resistance states has been uncovered near room temperature by
magnetization and magneto-transport measurements. The exchange anisotropy
originates from the exchange interaction between the ferrimagnetic and
ferromagnetic components corresponding to the two amorphous phases. This study
provides a platform for exchange bias and magneto-resistance switching using
single-layer amorphous ferrimagnetic thin films that require no epitaxial
growth.",1512.06103v1
2016-04-30,Micromagnetic Simulation of Amorphous Ferrimagnetic TbFeCo Films with Exchange Coupled Nanophases,"Amorphous ferrimagnetic TbFeCo thin films are found to exhibit exchange bias
effect near the compensation temperature by magnetic hysteresis loop
measurement. The observed exchange anisotropy is believed to originate from the
exchange interaction between the two nanoscale amorphous phases distributed
within the films. Here, we present a computational model of phase-separated
TbFeCo using micromagnetic simulation. Two types of cells with different Tb
concentration are distributed within the simulated space to obtain a
heterogeneous structure consisting of two nanoscale amorphous phases. Each cell
contains separated Tb and FeCo components, forming two antiferromagnetically
coupled sublattices. Using this model, we are able to show the existence of
exchange bias effect, and the shift in hysteresis loops is in agreement with
experiment. The micromagnetic model developed herein for a heterogeneous
magnetic material may also account for some recent measurements of exchange
bias effect in crystalline films.",1605.00099v1
2016-05-24,Spin Hall Magnetoresistance in a Canted Ferrimagnet,"We study the spin Hall magnetoresistance effect in ferrimagnet/normal metal
bilayers, comparing the response in collinear and canted magnetic phases. In
the collinear magnetic phase, in which the sublattice magnetic moments are all
aligned along the same axis, we observe the conventional spin Hall
magnetoresistance. In contrast, in the canted phase, the magnetoresistance
changes sign. Using atomistic spin model calculations of the magnetic
configuration, we show that the electric transport for the different magnetic
phases can be rationalized considering the individual sublattice moment
orientations. This enables a magneto-transport based investigation of
non-collinear magnetic textures.",1605.07441v1
2016-05-31,Spin-Orbit Torques in ferrimagnetic GdFeCo Alloys,"The spin-orbit torque switching of ferrimagnetic
Gd$_x$(Fe$_{90}$Co$_{10}$)$_{100-x}$ films was studied for both transition
metal (TM)-rich and rare earth (RE)-rich configurations. The spin-orbit torque
driven magnetization switching follows the same handedness in TM-rich and
RE-rich samples with respect to the total magnetization, but the handedness of
the switching is reversed with respect to the TM magnetization. This indicates
that the sign of the spin-orbit-torque-driven magnetic switching follows the
total magnetization, although transport based techniques such as anomalous Hall
effect are only sensitive to the transition metal magnetization. These results
provide important insight into the physics of spin angular momentum transfer in
materials with antiferromagnetically coupled sublattices.",1605.09498v1
2017-06-20,"Room Temperature Magnetoresistance and Exchange Bias in ""314 - type"" Oxygen-Vacancy Ordered SrCo$_{0.85}$Fe$_{0.15}$O$_{2.62}$","Herein, we report the magneto-transport and exchange bias effect in a ""314 -
type"" oxygen - vacancy ordered material with composition
SrCo$_{0.85}$Fe$_{0.15}$O$_{2.62}$. This material exhibits a ferrimagnetic
transition above room temperature, at 315 K. The negative magnetoresistance
starts to appear from room temperature (-1.3 $\%$ at 295 K in 70 kOe) and
reaches a sizable value of 58 $\%$ at 4 K in 70 kOe. Large exchange bias effect
is observed below 315 K when the sample is cooled in the presence of a magnetic
field. The coexistence of nearly compensated and ferrimagnetic regions in the
layered structure originate magnetoresistance and exchange bias in this sample.
The appearance of a sizable magnetoresistance and giant exchange bias effect,
especially near room temperature indicates that ""314-type"" cobaltates are a
promising class of material systems for the exploration of materials with
potential applications as magnetic sensors or in the area of spintronics.",1706.06264v2
2017-10-12,Temperature-dependent charge transport in the compensated ferrimagnet Mn$_{1.5}$V$_{0.5}$FeAl from first principles,"We present an ab-initio study of the temperature-dependent longitudinal and
anomalous Hall resistivities in the compensated collinear ferrimagnet
Mn$_{1.5}$V$_{0.5}$FeAl. Its transport properties are calculated using the
general fully relativistic Kubo--Bastin formalism and their temperature
dependency is accounted for magnetic and structural disorder. Both scattering
sources, together with the residual chemical disorder, were treated equally
provided by the CPA (Coherent Potential Approximation) SPR-KKR (Spin-Polarized
Relativistic Korringa-Kohn-Rostoker) method. All calculated properties showed
good agreement with a recent experimental results, providing useful specific
information on the chemical and magnetic arrangement as well as on the
influence of disorder. Finally, we demonstrated that the anomalous Hall effect
in such compensated systems occurs regardless of the vanishing net spin moment.",1710.04453v1
2018-01-23,Correlation between Magnetic Properties and Depinning Field in Field-Driven Domain Wall Dynamics in GdFeCo Ferrimagnets,"The influence of temperature on the magnetic-field-driven domain wall (DW)
motion is investigated in GdFeCo ferrimagnets with perpendicular magnetic
anisotropy (PMA). We find that the depinning field strongly depends on
temperature. Moreover, it is also found that the saturation magnetization
exhibits a similar dependence on temperature to that of depinning field. From
the creep-scaling criticality, a simple relation between the depinning field
and the properties of PMA is clearly identified theoretically as well as
experimentally. Our findings open a way for a better understanding how the
magnetic properties influence on the depinning field in magnetic system and
would be valuably extended to depinning studies in other system.",1801.07436v1
2018-10-15,Realizing Magnetoelectric Coupling with Hydroxide as a Knob,"Materials with a coexistence of magnetic and ferroelectric order (i.e.,
multiferroics) provide an efficient route for the control of magnetism by
electric fields. Unfortunately, a long-sought room temperature multiferroic
with strongly coupled ferroelectric and ferromagnetic (or ferrimagnetic)
orderings is still lacking. Here, we propose that hydrogen intercalation in
antiferromagnetic transition metal oxides is a promising way to realize
multiferroics with strong magnetoelectric coupling. Taking brownmillerite
SrCoO2.5 as an example, we show that hydrogen intercalated SrCoO2.5 displays
strong ferrimagnetism and large electric polarization in which the hydroxide
acts as a new knob to simultaneously control the magnetization and polarization
at room temperature. We expect that ion intercalation will become a general way
to design magnetoelectric and spintronic functional materials.",1810.06357v1
2018-10-25,Revisiting Goodenough-Kanamori rules in a new series of double perovskites LaSr$_{1-x}$Ca$_x$NiReO$_6$,"The magnetic ground state in highly ordered double perovskites
LaSr$_{1-x}$Ca$_x$NiReO$_6$ ($x$ = 0.0, 0.5, 1.0) were studied in view of the
Goodenough-Kanamori rules of superexchange interactions. In LaSrNiReO$_6$, Ni
and Re sublattices are found to exhibit curious magnetic states, but do not
show any long range magnetic ordering. The magnetic transition at $\sim$ 255 K
is identified with the Re sublattic magnetic ordering. The sublattice
interactions are tuned by modifying the Ni-O-Re bond angles via changing the
lattice structure through Ca doping. Upon Ca doping, the Ni and Re sublattices
start to display a ferrimagnetically ordered state at low temperature. The
neutron powder diffraction reveals a canted alignment between the Ni and the Re
sublattices, while the individual sublattice is ferromagnetic. The transition
temperature of the ferrimagnetic phase increases monotonically with increasing
Ca concentration.",1810.10995v1
2019-06-28,"Exploring the structural , electronic and magnetic properties of cation ordered 3d-5d double perovskite Bi$_2$FeReO$_6$ and Bi$_2$FeIrO$_6$ thin-films from first-principles","We report a first-principles study of Bi-based 3$d$-5$d$ ordered double
perovskite oxides (A$_2$BB$^\prime$O$_6$) with a 3$d$ atom (Fe) at the B-site
and 5$d$ atoms (Re,Ir) at the B$^\prime$-site while keeping highly polarizable
ions (Bi$^{3+}$) at the A-site. We find that, under coherent heteroepitaxy,
Bi$_2$FeReO$_6$} exhibits a strain-driven anti-ferromagnetic insulator to
ferrimagnetic semi-metal transition, while Bi$_2$FeIrO$_6$ shows correlation
driven ferromagnetic insulator to ferrimagnetic half-metal transition with
calculated magnetic moments of 5 $\mu_B$/f.u. and 3 $\mu_B$/f.u., respectively.
These properties along with the low band gaps in the insulating phases make the
compounds appealing for spintronics applications. Furthermore, in
Bi$_2$FeIrO$_6$, the conduction and valence states are localized on different
transition metal sublattices implying more efficient electron-hole separation
upon photoexcitation, a desirable feature for photovoltaic applications.",1907.00041v1
2019-06-30,Large spatial Schrodinger cat using a levitated ferrimagnetic nanoparticle,"The superposition principle is one of the main tenets of quantum mechanics.
Despite its counter-intuitiveness, it has been experimentally verified using
electrons, photons, atoms, and molecules. However, a similar experimental
demonstration using a nano or a micro particle is non-existent. Here in this
Letter, exploiting macroscopic quantum coherence and quantum tunneling, we
propose an experiment using levitated magnetic nanoparticle to demonstrate such
an effect. It is shown that the spatial separation between the delocalized
wavepackets of a $20~$nm ferrimagnetic yttrium iron garnet (YIG) nanoparticle
can be as large as $5~$$\mu$m. We argue that this large spatial separation can
be used to test different modifications such as collapse models to the standard
quantum mechanics. Furthermore, we show that the spatial superposition of a
core-shell structure, a YIG core and a non-magnetic silica shell, can be used
to probe quantum gravity.",1907.00415v4
2019-07-05,Theory for shift current of bosons: Photogalvanic spin current in ferrimagnetic and antiferromagnetic insulators,"We theoretically study the optical generation of dc spin current (i.e., a
spin-current solar cell) in ordered antiferromagnetic and ferrimagnetic
insulators, motivated by a recent study on the laser-driven spinon spin current
in noncentrosymmetric quantum spin chains [H. Ishizuka and M. Sato, Phys. Rev.
Lett. 122, 197702 (2019)]. Using a non-linear response theory for magnons, we
analyze the dc spin current generated by a linearly-polarized electromagnetic
wave (typically, terahertz or gigahertz waves). Considering noncentrosymmetric
two-sublattice magnets as an example, we find a finite dc spin current
conductivity at $T=0$, where no thermally-excited magnons exist; this is in
contrast to the case of the spinon spin current, in which the optical
transition of the Fermi degenerate spinons plays an essential role. We find
that the dc spin-current conductivity is insensitive to the Gilbert damping,
i.e., it may be viewed as a shift current carried by bosonic particles
(magnons). Our estimate shows that an electric-field intensity of
$E\sim10^4-10^6$ V/cm is sufficient for an observable spin current. Our theory
indicates that the linearly-polarized electromagnetic wave generally produces a
dc spin current in noncentrosymmetric magnetic insulators.",1907.02734v1
2019-09-24,Ground-State Phases of Alternating-Bond S = 1 Diamond Chains,"The ground-state phases of alternating-bond spin-1 diamond chains are
investigated. Each ground state consists of an array of spin clusters separated
by singlet dimers owing to an infinite number of local conservation laws. If no
singlet dimers are present, the ground state is equivalent to that of a spin
chain with infinite length.For strong frustration, we find a series of quantum
phase transitions as in the case of alternating-bond mixed diamond chains with
spins 1 and 1/2. For intermediate frustration, we find the nonmagnetic Haldane
or dimer phases according to whether the bond alternation is weak or strong.
For weak frustration and weak bond alternation, we find the ferrimagnetic
states with spontaneous magnetizations $m=1/6$ and 1/3 per site. The
ferrimagnetic state with $m=1/6$ is accompanied by a spontaneous translational
symmetry breakdown. This phase vanishes for strong bond alternation.",1909.11026v2
2019-10-16,Magnetic Nanoparticle Chains in Gelatin Ferrogels: Bioinspiration from Magnetotactic Bacteria,"Inspired by chains of ferrimagnetic nanocrystals (NCs) in magnetotactic
bacteria (MTB), the synthesis and detailed characterization of ferrimagnetic
magnetite NC chain-like assemblies is reported. An easy green synthesis route
in a thermoreversible gelatin hydrogel matrix is used. The structure of these
magnetite chains prepared with and without gelatin is characterized by means of
transmission electron microscopy, including electron tomography (ET). These
structures indeed bear resemblance to the magnetite assemblies found in MTB,
known for their mechanical flexibility and outstanding magnetic properties and
known to crystallographically align their magnetite NCs along the strongest
<111> magnetization easy axis. Using electron holography (EH) and angular
dependent magnetic measurements, the magnetic interaction between the NCs and
the generation of a magnetically anisotropic material can be shown. The
electro- and magnetostatic modeling demonstrates that in order to precisely
determine the magnetization (by means of EH) inside chain-like NCs assemblies,
their exact shape, arrangement and stray-fields have to be considered (ideally
obtained using ET).",1910.07293v1
2019-10-29,Laser induced ultrafast 3d and 4f spin dynamics in CoDy ferrimagnetic alloys as a function of temperature,"We report on an element- and time-resolved investigation of femtosecond laser
induced ultrafast dynamics of 3d and 4f spins in a ferrimagnetic Co80Dy20 alloy
as a function of temperature. We observe an increase of the Co3d characteristic
demagnetization time and a decrease of the Dy4f demagnetization time when the
temperature is approaching the Curie temperature. It suggests that the critical
slowing down regime, which affects the laser induced ultrafast dynamics in pure
3d transition metals and 4f rare-earth ferromagnetic layers, vanishes for the
Dy sublattice in the CoDy alloy, in line with the theoretical predictions of
the Landau-Lifshitz-Bloch model.",1910.13143v2
2020-02-14,Low energy magnons in the chiral ferrimagnet $\text{Cu}_2\text{OSeO}_3$: a coarse-grained approach,"We report a comprehensive neutron scattering study of low energy magnetic
excitations in the breathing pyrochlore helimagnetic
$\text{Cu}_2\text{OSeO}_3$. Fully documenting the four lowest energy magnetic
modes that leave the ferrimagnetic configuration of the ""strong tetrahedra""
intact ($|\hbar\omega|<13$ meV), we find gapless quadratic dispersion at the
$\Gamma$ point for energies above 0.2 meV, two doublets separated by 1.6(2) meV
at the $R$ point, and a bounded continuum at the $X$ point. Our constrained
rigid spin cluster model relates these features to Dzyaloshinskii-Moriya (DM)
interactions and the incommensurate helical ground state. Combining
conventional spin wave theory with a spin cluster form-factor accurately
reproduces the measured equal time structure factor through multiple Brillouin
zones. An effective spin Hamiltonian describing the complex anisotropic
inter-cluster interactions is obtained.",2002.06283v2
2020-02-10,"Phase diagram of the mixed-spin (1,3/2) Ising ferrimagnetic system with two different anisotropies","In this work, we have performed Monte Carlo simulations to study phase
transitions in a mixed spin-1 and spin-3/2 Ising ferrimagnetic system on the
square and cubic lattices and with two different single-ion anisotropies. This
lattice is divided in two interpenetrating sublattices with spins $S^A = 1$
(states $\pm1$ and 0) on the sublattice $A$ and $S^B = 3/2$ (states $\pm 3/2$,
$\pm 1/2$) on the sublattice $B$. We have used single-ion anisotropies $D_{A}$
and $D_{B}$ acting on the sites of the sublattice $A$ and $B$, receptively. We
have determined the phase diagrams of the model in the temperature $T$ versus
the single-ion anisotropies strength $D_A$ and $D_B$ plane and shown that the
system exhibits both second- and first-order phase transitions. We also have
shown that this system displays compensation points for some values of the
anisotropies.",2002.08421v1
2020-04-09,Hysteresis-free magnetization reversal of exchange-coupled bilayers with finite magnetic anisotropy,"Exchange-coupled structures consisting of ferromagnetic and ferrimagnetic
layers become technologically more and more important. We show experimentally
the occurrence of completely reversible, hysteresis-free minor loops of [Co(0.2
nm)/Ni(0.4 nm)/Pt(0.6 nm)]$_N$ multilayers exchange-coupled to a 20 nm thick
ferrimagnetic Tb$_{28}$Co$_{14}$Fe$_{58}$ layer, acting as hard magnetic
pinning layer. Furthermore, we present detailed theoretical investigations by
means of micromagnetic simulations and most important a purely analytical
derivation for the condition of the occurrence of full reversibility in
magnetization reversal. Hysteresis-free loops always occur if a domain wall is
formed during the reversal of the ferromagnetic layer and generates an
intrinsic hard-axis bias field that overcomes the magnetic anisotropy field of
the ferromagnetic layer. The derived condition further reveals that the
magnetic anisotropy and the bulk exchange of both layers, as well as the
exchange coupling strength and the thickness of the ferromagnetic layer play an
important role for its reversibility.",2004.04419v1
2020-04-11,Anomalous Hall Effect in Layered Ferrimagnet MnSb2Te4,"We report on low-temperature electron transport properties of MnSb2Te4, a
candidate of ferrimagnetic Weyl semimetal. Long -range magnetic order is
manifested as a nearly square-shaped hysteresis loop in the anomalous Hall
resistance, as well as sharp jumps in the magnetoresistance. At temperatures
below 4 K, a lnT-type upturn appears in the temperature dependence of
longitudinal resistance, which can be attributed to the electron-electron
interaction (EEI), since the weak localization can be excluded by the
temperature dependence of magnetoresistance. Although the anomalous Hall
resistance exhibits a similar lnT-type upturn in the same temperature range,
such correction is absent in the anomalous Hall conductivity. Our work
demonstrates that MnSb2Te4 microflakes provide an ideal system to test the
theory of EEI correction to the anomalous Hall effect.",2004.05397v1
2021-01-20,Magnetic properties of alternating Hubbard ladders,"We investigate the Hubbard Hamiltonian on ladders where the number of sites
per rung alternates between two and three. These geometries are bipartite, with
a non-equal number of sites on the two sublattices. Thus they share a key
feature of the Hubbard model in a class of lattices which Lieb has shown
analytically to exhibit long-range ferrimagnetic order, while being amenable to
powerful numeric approaches developed for quasi-one-dimensional geometries. The
Density Matrix Renormalization Group (DMRG) method is used to obtain the ground
state properties, e.g. excitation gaps, charge and spin densities as well as
their correlation functions at half-filling. We show the existence of
long-range ferrimagnetic order in the one-dimensional ladder geometries. Our
work provides detailed quantitative results which complement the general
theorem of Lieb for generalized bipartite lattices. It also addresses the issue
of how the alternation between quasi-long range order and spin liquid behavior
for uniform ladders with odd and even numbers of legs might be affected by a
regular alternation pattern.",2101.08229v2
2012-05-23,Two-step transition in a magnetoelectric ferrimagnet Cu2OSeO3,"We report a detailed single crystal investigation of a magnetoelectric
ferrimagnet Cu2OSeO3 using dc magnetization and ac susceptibility along the
three principal directions [100], [110] and [111]. We have observed that in
small magnetic fields two magnetic transitions occur, one at Tc = 57 K and the
second one at TN = 58 K. At Tc the non-linear susceptibility reveals the
emergence of the ferromagnetic component and below Tc the magnetization
measurements show the splitting between field-cooled and zero-field-cooled
regimes. Above 1000 Oe the magnetization saturates and the system is in a
single domain state. The temperature dependence of the saturation below Tc can
be well described by m(T) = m(0)[1 - (T/Tc)^2]^{\beta}, with m(0) = 0.56
(mu)B/Cu, corresponding to the 3-up-1-down configuration. The dielectric
constant measured on a thin single crystal shows a systematic deviation below
the transition, indicating an intrinsic magnetoelectric effect.",1205.5100v1
2017-05-08,Exchange coupling of a perpendicular ferromagnet to a half-metallic compensated ferrimagnet via a thin hafnium interlayer,"A thin Hafnium film is shown to act both as an effective diffusion barrier
for manganese at a thickness of 0.7 nm, and as an effective exchange coupling
layer in a sandwich structure with perpendicular magnetic anisotropy. The
magnetic layers are Co$_{20}$Fe$_{60}$B$_{20}$ and the low moment ferrimagnet
Mn$_2$Ru$_x$Ga (MRG). The coupling changes sign at the compensation temperature
of MRG and the exchange energy reaches 0.11 mJm$^{-2}$ for the thinnest Hf
interlayers. Ruthenium, the usual metal of choice for coupling ferromagnetic
layers in thin film heterostructures, cannot be used with the zero-moment half
metal MRG because of Ru interdiffusion. Due to its large coercivity near
compensation, the MRG can act as an effective source of exchange pinning.",1705.02804v1
2017-11-03,Compressible Ferrimagnetism in the depleted Periodic Anderson Model,"Tight-binding Hamiltonians with single and multiple orbitals exhibit an
intriguing array of magnetic phase transitions. In most cases the spin ordered
phases are insulating, while the disordered phases may be either metallic or
insulating. In this paper we report a Determinant Quantum Monte Carlo study of
interacting electrons in a geometry which can be regarded as a two-dimensional
Periodic Anderson Model with depleted interacting ($f$) orbitals. For a single
depletion, we observe an enhancement of antiferromagnetic correlations and
formation of localized states. For half of the $f$-orbitals regularly depleted,
the system exhibits a ferrimagnetic ground state. We obtain a quantitative
determination of the nature of magnetic order, which we discuss in the context
of Tsunetsugu's theorem, and show that, although the dc conductivity indicates
insulating behavior at half-filling, the compressibility remains finite.",1711.00983v1
2017-11-19,Ferroelectric Ferrimagnetic LiFe$_2$F$_6$: Charge Ordering Mediated Magnetoelectricity,"Trirutile-type LiFe$_2$F$_6$ is a charge-ordered material with
Fe$^{2+}$/Fe$^{3+}$ configuration. Here its physical properties, including
magnetism, electronic structure, phase transition, and charge ordering, are
studied theoretically. On one hand, the charge ordering leads to improper
ferroelectricity with a large polarization. On the other hand, its magnetic
ground state can be tuned from the antiferromagnetic to ferrimagnetic by
moderate compressive strain. Thus, LiFe$_2$F$_6$ can be a rare multiferroic
with both large magnetization and polarization. Most importantly, since the
charge ordering is the common ingredient for both ferroelectricity and
magnetization, the net magnetization may be fully switched by flipping the
polarization, rendering intrinsically strong magnetoelectric effect and
desirable function.",1711.06981v2
2017-11-23,Magnetic and Electronic Properties of Spin-Orbit Coupled Dirac Electrons on a $(001)$ Thin Film of Double Perovskite Sr$_2$FeMoO$_6$,"We present an interacting model for the electronic and magnetic behavior of a
strained $(001)$ atomic layer of Sr$_2$FeMoO$_6,$ which shows room-temperature
ferrimagnetism and magnetoresistance with potential spintronics application in
the bulk. We find that the strong spin-orbit coupling in the molybdenum 4$d$
shell gives rise to a robust ferrimagnetic state with an emergent
spin-polarized electronic structure consisting of flat bands and four massive
or massless Dirac dispersions. Based on the spin-wave theory, we demonstrate
that the magnetic order remains intact for a wide range of doping, leading to
the possibility of exploring flat band physics, such as Wigner crystallization
in electron-doped Sr$_{2-x}$La$_{x}$FeMoO$_6.$",1711.08674v3
2018-06-04,Monte Carlo simulation of equilibrium and dynamic phase transition properties of an Ising bilayer,"Magnetic properties of an Ising bilayer system defined on a honeycomb lattice
with non-magnetic interlayers which interact via an indirect exchange coupling
have been investigated by Monte Carlo simulation technique. Equilibrium
properties of the system exhibit ferrimagnetism with $P$-, $N$- and $Q$- type
behaviors. Compensation phenomenon suddenly disappears with decreasing strength
of indirect ferrimagnetic interlayer exchange coupling. Qualitative properties
are in a good agreement with those obtained by effective field theory. In order
to investigate the stochastic dynamics of kinetic Ising bilayer, we have
introduced two different types of dynamic magnetic fields, namely a square
wave, and a sinusoidally oscillating magnetic field form. For both field types,
compensation point and critical temperature decrease with increasing amplitude
and field period. Dynamic ferromagnetic region in the presence of square wave
magnetic field is narrower than that obtained for sinusoidally oscillating
magnetic field when the amplitude and the field period are the same for each
type of dynamic magnetic fields.",1806.01002v2
2018-06-28,Spin relaxation in multilayers with synthetic ferrimagnets,"We demonstrate a strong tunability of the spin-pumping contribution to
magnetic damping in a thin-film ferromagnetic free layer interfaced with a
synthetic ferrimagnet (SFM), acting as a spin-sink, via a thin Cu-spacer. The
effect strongly depends on the magnetic state of the SFM, a trilayer structure
composed of two Fe layers coupled via indirect exchange mediated by a Cr
spacer. With increasing Cr thickness, the SFM state undergoes a transition from
an antiparallel via a non-collinear to a parallel configuration. We can explain
the corresponding non-monotonous dependence of spin relaxation in the free
layer in terms of a modulation of the longitudinal spin transport as well as
relaxation of the transverse angular momentum in the SFM. The results should be
useful for designing high-speed spintronic devices where tunability of spin
relaxation is advantageous.",1806.10911v2
2018-07-07,Topological multiferroic phases in the extended Kane-Mele-Hubbard Model in the Hofstadter regime,"We investigate the new quantum phases on the extended Kane-Mele-Hubbard model
of honeycomb lattice in the Hofstadter regime. In this regime, orbital motion
of the electrons can induce various topological phases with spontaneously
broken symmetries when the spin orbit coupling and electron correlations
coexist. Here, we consider the interaction effects in the Kane-Mele model and
discuss possible phases in the presence of magnetic field at integer fillings
of electrons. In particular, focusing on 2{\pi}/3 magnetic flux per plaquette,
the realization of numerous quantum phases are discussed within the mean field
framework; insulator with coplanar magnetic ordering, ferrimagnetic Chern
insulator with nematic charge order, ferrimagnetic-ferrielectric Chern
insulators etc. Many of these phase transitions are also accompanied with the
change in the topological invariants of the system. Based on our theoretical
study, we propose topological multiferroic phases with a scope of realization
in 2D van-der Waals materials and optical lattice system where the significant
interplay of magnetic field, spin orbit coupling and interactions can be
engineered.",1807.02686v1
2018-12-13,Imaging Domains in a Zero-Moment Half Metal,"We have a choice of methods for examining domains at the surface of a
ferromagnet that depend on probing the stray field distribution, but these
methods do not work in antiferromagnets or compensated ferrimagnets, which
produce no stray field. The discovery of compensated ferrimagnetic half-metals
allows for the local magnetization state to be observed directly with polarized
light. The example considered here, Mn$_{2}$Ru$_{x}$Ga, has two inequivalent
but oppositely-aligned Mn sublattices with equal and opposite moments, but only
one of them contributes spin polarized conduction electrons at the Fermi
energy. The material looks like an antiferromagnet from the outside, but from
the point of view of electronic structure it resembles a spin-polarized
ferromagnetic metal. The anisotropy axis is perpendicular to the film plane,
which allows domains to be imaged directly by polar magneto-optic Kerr effect.
The domain structure in a film with a composition of Mn$_{2}$Ru$_{0.4}$Ga has
been imaged in a Kerr microscope and hysteresis loops traced. Domains have
dimensions of order 20 {\mu}m with meandering domain walls and a fractal
dimension D$_{f}$ = 1.85. Our results open new direct imaging possibilities for
magnetically-ordered materials with no net moment.",1812.05371v1
2019-01-02,Giant negative magnetoresistance and kinetic arrest of first-order ferrimagnetic-antiferomagnetic transition in Ge doped Mn$_2$Sb,"Effect of Ge substitution on first order ferrimagnetic (FRI) -
antiferromagnetic (AFM) transition in Mn$_2$Sb has been studied. It shows that
transition temperature (T$_t$) can be tuned between 119~K - 271~K by
substituting 2.5-10\% Ge at Sb site in Mn$_2$Sb. The variation of density of
state at Fermi level N(E$_f$) with Ge substitution shows that dN(E)/dE is
positive at E$_f$ in the AFM state. With the application of magnetic field
T$_t$ shifts to low temperature, which results in a giant negative
magnetoresistance (MR) reaching a value of 70\% for 2.5\% substitution. Our
results show that FRI to AFM transformation during cooling stops around 35 K,
even though it remains incomplete. It along with non-monotonic variation of
lower critical field, open loop in isothermal MR and increasing difference in
zero field cooled warming (ZFCW) and field cooled warming (FCW) resistivity
with increasing magnetic field shows that FRI to AFM transition is kinetically
arrested in the case of 2.5\% Ge substitution.",1901.00442v1
2019-01-21,Mn4N ferrimagnetic thin films for sustainable spintronics,"Spintronics, which is the basis of a low-power, beyond-CMOS technology for
computational and memory devices, remains up to now entirely based on critical
materials such as Co, heavy metals and rare-earths. Here, we show that Mn4N, a
rare-earth free ferrimagnet made of abundant elements, is an exciting candidate
for the development of sustainable spintronics devices. Mn4N thin films grown
epitaxially on SrTiO3 substrates possess remarkable properties, such as a
perpendicular magnetisation, a very high extraordinary Hall angle (2%) and
smooth domain walls, at the millimeter scale. Moreover, domain walls can be
moved at record speeds by spin polarised currents, in absence of spin-orbit
torques. This can be explained by the large efficiency of the adiabatic spin
transfer torque, due to the conjunction of a reduced magnetisation and a large
spin polarisation. Finally, we show that the application of gate voltages
through the SrTiO3 substrates allows modulating the Mn4N coercive field with a
large efficiency.",1901.06868v2
2019-01-27,Correlation effects on ground-state properties of ternary Heusler alloys: first-principles study,"The strongly constrained and appropriately normed (SCAN) semi-local
functional for exchange-correlation is deployed to study the ground-state
properties of ternary Heusler alloys transforming martensitically. The
calculations are performed for ferromagnetic, ferrimagnetic, and
antiferromagnetic phases. Comparisons between SCAN and generalized gradient
approximation (GGA) are discussed. We find that SCAN yields smaller lattice
parameters and higher magnetic moments compared to the GGA corresponding values
for both austenite and martensite phases. Furthermore, in the case of
ferromagnetic and non-magnetic Heusler compounds, GGA and SCAN display similar
trends in the total energy as a function of lattice constant and tetragonal
ratio. However, for some ferrimagnetic Mn-rich Heusler compounds, different
magnetic ground states are found within GGA and SCAN.",1901.09460v1
2019-02-04,Magnetic phase separation in a frustrated ferrimagnetic chain under a magnetic field,"We use density matrix renormalization group to study the first-order quantum
phase transition induced by a magnetic field $h$ in a frustrated ferrimagnetic
chain. The magnetization ($m$) curve as a function of $h$ presents a
macroscopic jump and the energy curve as a function of $m$ has two global
minima. We characterize the two competing phases and study the phase-separated
states in the coexistence region. Also, we observe that the transition is
accompanied by an increase in the number of itinerant singlet pairs between
sites in the unit cells of the chain. Finally, we identify the critical point
at the end of the first-order transition line and a crossover line.",1902.01292v1
2019-03-19,H-T Phase Diagram of Rare-Earth -- Transition Metal Alloy in the Vicinity of the Compensation Point,"Anomalous hysteresis loops of ferrimagnetic amorphous alloys in high magnetic
field and in the vicinity of the compensation temperature have so far been
explained by sample inhomogeneities. We obtain H-T magnetic phase diagram for
ferrimagnetic GdFeCo alloy using a two-sublattice model in the paramagnetic
rare-earth ion approximation and taking into account rare-earth (Gd) magnetic
anisotropy. It is shown that if the magnetic anisotropy of the $f$-sublattice
is larger than that of the $d$-sublattice, the tricritical point can be at
higher temperature than the compensation point. The obtained phase diagram
explains the observed anomalous hysteresis loops as a result of high-field
magnetic phase transition, the order of which changes with temperature. It also
implies that in the vicinity of the magnetic compensation point the shape of
magnetic hysteresis loop is strongly temperature dependent.",1903.07941v1
2019-04-03,"Tetramer Orbital-Ordering induced Lattice-Chirality in Ferrimagnetic, Polar MnTi2O4","Using density-functional theory calculations and experimental investigations
on structural, magnetic and dielectric properties, we have elucidated a unique
tetragonal ground state for MnTi2O4, a Ti^{3+} (3d^1)-ion containing
spinel-oxide. With lowering of temperature around 164 K, cubic MnTi2O4
undergoes a structural transition into a polar P4_1 tetragonal structure and at
further lower temperatures, around 45 K, the system undergoes a paramagnetic to
ferrimagnetic transition. Magnetic superexchange interactions involving Mn and
Ti spins and minimization of strain energy associated with co-operative
Jahn-Teller distortions plays a critical role in stabilization of the unique
tetramer-orbital ordered ground state which further gives rise to lattice
chirality through subtle Ti-Ti bond-length modulations.",1904.01792v1
2019-04-03,Observation of Topological Hall Effect and Signature of Room Temperature Antiskyrmions in Mn-Ni-Ga D2d Heusler magnets,"Topologically stable nontrivial spin structures, such as skyrmions and
antiskyrmions, display a large topological Hall effect owing to their quantized
topological charge. Here, we present the finding of a large topological Hall
effect beyond room temperature in the tetragonal phase of a Mn-Ni-Ga based
ferrimagnetic Heusler shape memory alloy system. The origin of the field
induced topological phase, which is also evidenced by the appearance of dips in
the ac-susceptibility measurements, is attributed to the presence of magnetic
antiskyrmions driven by D2d symmetry of the inverse Heusler tetragonal phase.
Detailed micromagnetic simulations asserts that the antiskyrmionic phase is
stabilized as a result of interplay among inhomogeneous Dzyaloshinskii-Moriya
interaction, the Heisenberg exchange, and the magnetic anisotropy energy. The
robustness of the present result is demonstrated by stabilizing the
antiskyrmion hosting tetragonal phase up to a temperature as high as 550 K by
marginally varying the chemical composition, thereby driving us a step closer
to the realization of ferrimagnetic antiskyrmion based racetrack memory.",1904.01894v1
2019-04-14,Evolution of magnetic ordering in FeCr$_2$Se$_{4-x}$Te$_x$; $x$ = 0 -- 4.0,"We have systematically studied the magnetic properties of chromium chalcogene
compounds FeCr$_2$Se$_{4-x}$Te$_x$. The FeCr2Se4 undergoes antiferromagnetic
ordering below 222 K. Substitution of tellurium lowers the antiferromagnetic
ordering temperature and leads to short range ferromagnetic cluster behavior
towards the tellurium end. Change over from antiferromagnetic to ferrimagnetic
like behavior is also reflected in the corresponding transformation from
semiconducting to metallic transport behavior. There is a large variation in
the Curie-Weiss temperature, effective magnetic moment and ordering temperature
(TN / TC) with Te substitution. The electronic band structure calculations
suggest antiferromagnetic and ferrimagnetic ground state for the FeCr2Se4 and
FeCr2Te4 respectively.",1904.06661v1
2019-04-19,Sub-terahertz ferrimagnetic spin-transfer torque oscillator,"A theory of magnetization dynamics in ferrimagnetic materials with
antiparallel aligned spin sub-lattices under action of spin-transfer torques
(STT) is developed. We consider magnetization dynamics in GdFeCo layers in two
cases of magnetic anisotropy: easy plane and easy axis. We demonstrate that,
(i) for the easy plane anisotropy the precession of the N\'{e}el vector is
conical and the cone angle depends on the STT strength and the value of spin
non-compensation, while the frequency of precession can reach sub-THz
frequencies; (ii) for the easy axis anisotropy two regimes are possible:
deterministic switching of the net magnetization and a conical sub-THz
precession depending on the STT strength.",1904.09341v1
2019-04-24,Anomalous thermodynamic response in the vicinity of pseudo-transition of a spin-1/2 Ising diamond chain,"The spin-1/2 Ising diamond chain in a magnetic field displays a remarkable
pseudo-transition whenever it is driven sufficiently close to a ground-state
phase boundary between a classical ferrimagnetic phase and a highly degenerate
frustrated phase. The pseudo-transition of the spin-1/2 Ising diamond chain
relates to intense thermal excitations from a nondegenerate ferrimagnetic
ground state to a highly degenerate manifold of excited states with a
frustrated character, which are responsible for an anomalous behavior of
thermodynamic quantities. Temperature dependences of entropy and specific heat
are indeed reminiscent of a temperature-driven phase transition of a
discontinuous (entropy) or continuous (specific heat) nature though there are
no true singularities of these thermodynamic quantities at a pseudo-critical
temperature.",1904.10704v3
2019-08-20,Comparing all-optical switching in synthetic-ferrimagnetic multilayers and alloys,"We present an experimental and theoretical investigation of all-optical
switching by single femtosecond laser pulses. Our experimental results
demonstrate that, unlike rare earth-transition metal ferrimagnetic alloys,
Pt/Co/[Ni/Co]$_N$/Gd can be switched in the absence of a magnetization
compensation temperature, indicative for strikingly different switching
conditions. In order to understand the underlying mechanism, we model the
laser-induced magnetization dynamics in Co/Gd bilayers and GdCo alloys on an
equal footing, using an extension of the microscopic three-temperature model to
multiple magnetic sublattices and including exchange scattering. In agreement
with our experimental observations, the model shows that Co/Gd bilayers can be
switched for an arbitrary thickness of the Co layer, i.e, even far away from
compensating the total Co and Gd magnetic moment. We identify the switching
mechanism in Co/Gd bilayers as a front of reversed Co magnetization that
nucleates at the Co/Gd interface and propagates through the Co layer driven by
exchange scattering.",1908.07292v2
2019-08-23,Precession-free domain wall dynamics in compensated ferrimagnets,"One fundamental obstacle to efficient ferromagnetic spintronics is magnetic
precession, which intrinsically limits the dynamics of magnetic textures, We
demonstrate that the domain wall precession fully vanishes with a record
mobility when the net angular momentum is compensated (TAC) in DWs driven by
spin-orbit torque in a ferrimagnetic GdFeCo/Pt track. We use transverse
in-plane fields to reveal the internal structure of DWs and provide a robust
and parameter-free measurement of TAC. Our results highlight the mechanism of
faster and more efficient dynamics in materials with multiple spin lattices and
reduced net angular momentum, promising for high-speed, low-power spintronics
applications.",1908.08867v2
2019-08-26,Ferrimagnetism and anisotropic phase tunability by magnetic fields in Na$_2$Co$_2$TeO$_6$,"Na$_2$Co$_2$TeO$_6$ has recently been proposed to be a Kitaev-like honeycomb
magnet. To assess how close it is to realizing Kitaev quantum spin liquids, we
have measured magnetization and specific heat on high-quality single crystals
in magnetic fields applied along high-symmetry directions. Small training
fields reveal a weak but canonical ferrimagnetic behavior below 27 K, which
cannot be explained by the zigzag antiferromagnetic order alone and suggests
coexisting N\'{e}el-type order of moments canted away from the zigzag chains.
Moderate fields in the honeycomb plane suppress the thermal transition at 27 K,
and seem to partly reverse the moment-canting when applied perpendicular to the
zigzag chains. In contrast, out-of-plane fields leave the transition largely
unaffected, but promotes another transition below 10 K, possibly also related
to canting reversal. The magnetism in Na$_2$Co$_2$TeO$_6$ is highly anisotropic
and close to tipping points between competing phases.",1908.09427v1
2019-11-05,Numerical methods for antiferromagnetics,"Compared with ferromagnetic counterparts, antiferromagnetic materials are
considered as the future of spintronic applications since these materials are
robust against the magnetic perturbation, produce no stray field, and display
ultrafast dynamics. There are (at least) two sets of magnetic moments in
antiferromagnets (with magnetization of the same magnitude but antiparallel
directions) and ferrimagnets (with magnetization of the different magnitude).
The coupled dynamics for the bipartite collinear antiferromagnets is modeled by
a coupled system of Landau-Lifshitz-Gilbert equations with an additional term
originated from the antiferromagnetic exchange, which leads to femtosecond
magnetization dynamics. In this paper, we develop three Gauss-Seidel projection
methods for micromagnetics simulation in antiferromagnets and ferrimagnets.
They are first-order accurate in time and second-order in space, and only solve
linear systems of equations with constant coefficients at each step.
Femtosecond dynamics, N\'{e}el wall structure, and phase transition in presence
of an external magnetic field for antiferromagnets are provided with the
femtosecond stepsize.",1911.01717v1
2020-03-03,Sub-picosecond exchange-relaxation in the compensated ferrimagnet Mn$_2$Ru$_x$Ga,"We study the demagnetization dynamics of the fully compensated half-metallic
ferrimagnet Mn$_2$Ru$_x$Ga. While the two antiferromagnetically coupled
sublattices are both composed of manganese, they exhibit different temperature
dependencies due to their differing local environments. The sublattice
magnetization dynamics triggered by femtosecond laser pulses are studied to
reveal the roles played by the spin and intersublattice exchange. We find a
two-step demagnetization process, similar to the well-established case of
Gd(FeCo)$_3$, where the two Mn-sublattices have different demagnetization
rates. The behaviour is analysed using a four-temperature model, assigning
different temperatures to the two manganese spin baths. Even in this strongly
exchange-coupled system, the two spin reservoirs have considerably different
behaviour. The half-metallic nature and strong exchange coupling of
Mn$_2$Ru$_x$Ga lead to spin angular momentum conservation at much shorter time
scales than found for Gd(FeCo)$_3$ which suggests that low-power,
sub-picosecond switching of the net moment of Mn$_2$Ru$_x$Ga is possible.",2003.01420v1
2020-03-05,Giant Thermal Enhancement of the Electric Polarization in Ferrimagnetic BiFe$_{1-x}$Co$_{x}$O$_{3}$ Solid Solutions Near Room Temperature,"Thermal excitations typically reduce the electric polarization in
ferroelectric materials. Here, we show by means of first-principles
calculations that multiferroic BiFe$_{1-x}$Co$_{x}$O$_{3}$ solid solutions with
$0.25 \le x \le 0.50$ (BFCO) represent a noteworthy exception to this
behaviour. In particular, we find that at room temperature and for moderate
pressures of $0.1$-$1.0$ GPa, depending on the composition, the electric
polarization of bulk BFCO increases by $\sim 200$%. The origin of such an
exceptional behavior is a phase transformation involving a low-$T$ rhombohedral
(${\cal R}$) phase and a high-$T$ super-tetragonal (${\cal T}$) phase. Both
${\cal R}$ and ${\cal T}$ phases are ferrimagnetic near room temperature with
an approximate net magnetization of $0.13$$\mu_{B}$ per formula unit.
Contrarily to what occurs in either bulk BiFeO$_{3}$ or BiCoO$_{3}$, the ${\cal
T}$ phase is stabilized over the ${\cal R}$ by increasing temperature due to
its higher vibrational entropy. This extraordinary $T$-induced ${\cal R} \to
{\cal T}$ phase transition is originated by polar phonon modes involving
concerted displacements of transition-metal and oxygen ions.",2003.02949v1
2020-05-13,Waveguide cavity optomagnonics for broadband multimode microwave-to-optics conversion,"Cavity optomagnonics has emerged as a promising platform for studying
coherent photon-spin interactions as well as tunable microwave-to-optical
conversion. However, current implementation of cavity optomagnonics in
ferrimagnetic crystals remains orders of magnitude larger in volume than
state-of-the-art cavity optomechanical devices, resulting in very limited
magneto-optical interaction strength. Here, we demonstrate a cavity
optomagnonic device based on integrated waveguides and its application for
microwave-to-optical conversion. By designing a ferrimagnetic rib waveguide to
support multiple magnon modes with maximal mode overlap to the optical field,
we realize a high magneto-optical cooperativity which is three orders of
magnitude higher compared to previous records obtained on polished YIG spheres.
Furthermore, we achieve tunable conversion of microwave photons at around 8.45
GHz to 1550 nm light with a broad conversion bandwidth as large as 16.1 MHz.
The unique features of the system point to novel applications at the crossroad
between quantum optics and magnonics.",2005.06429v1
2020-06-14,Hypersonic heat-induced flows of magnons induced by femtosecond laser pulses,"In this work, we present evidence for the existence of a magnonic current on
the sub-picosecond time-scale in a ferrimagnetic bilayer and its effect on
ultrafast spin dynamics. The ferrimagnet, GdFeCo, is a material known to
undergo ultrafast switching within 1-2ps after excitation with femtosecond
laser pulses. Here, we show that the strong thermal gradients induced by
applying femtosecond laser pulses and the presence of chemical inhomogeneities
lead to local imbalances in the effective temperatures of the spins that
produces a rapid transfer of spin angular momentum, which we interpret as an
ultrafast spin Seebeck effect. We have quantified the typical magnon
propagation in such a system. The results show ballistic magnon propagation
with 30nm/ps velocities. The characteristic time scale of such magnon
propagation indicates that this magnon transport can play an important role in
switching, a crucial piece of understanding towards realising next generation
data processing devices that operate at much higher frequencies.",2006.07935v1
2020-08-04,Two-step magnetic ordering into a canted state in ferrimagnetic monoclinic Mn$_3$As$_2$,"We report the magnetic structure of room-temperature-stable, monoclinic
Mn$_3$As$_2$ at 3 K and 250 K using neutron powder diffraction measurements.
From magnetometry data, the Curie temperature of Mn$_3$As$_2$ was confirmed to
be around 270 K. Calorimetry analysis showed the presence of another transition
at 225 K. At 270 K, Mn$_3$As$_2$ undergoes a $k = 0$ ferrimagnetic ordering in
the magnetic space group $C2/m$ (#12.58) with Mn moments pointing along $b$.
Below 225 K, there is a canting of Mn moments in the $ac$ plane which produces
a multi-$k$ non-collinear magnetic structure in space group $C2/c$ (#15.85).
The components of Mn moments along $b$ follow $k=0$ ordering and the components
along $a$ and $c$ have $k = [0 0 \frac{1}{2}]$ propagation vector. The change
in the magnetic ground state with temperature provides a deeper insight into
the factors that govern magnetic ordering in Mn-As compounds.",2008.01776v2
2020-10-23,Magnetic and structural properties of Ni-substituted magnetoelectric Co$_4$Nb$_2$O$_9$,"The magnetic and structural properties of polycrystalline Co$_{4-x}$ Ni$_x$
Nb$_2$ O$_9$ (x=1,2) have been investigated by neutron powder diffraction,
magnetization and heat capacity measurements, and density functional theory
(DFT) calculations. For x=1, the compound crystallizes in the trigonal
P$\bar{3}$c1 space group. Below T$_N$ = 31 K it develops a weakly non-collinear
antiferromagnetig structure with magnetic moments in the ab-plane. The compound
with x=2 has crystal structure of the orthorhombic Pbcn space group and shows a
hard ferrimagnetic behavior below T$_C$ =47 K. For this compound a weakly
non-collinear ferrimagnetic structure with two possible configurations in ab
plane was derived from ND study. By calculating magnetic anisotropy energy via
DFT, the ground-state magnetic configuration was determined for this compound.
The heat capacity study in magnetic fields up to 140 kOe provide further
information on the magnetic structure of the compounds.",2010.12285v1
2020-10-29,Collective spin dynamics under dissipative spin Hall torque,"Current-induced spin torques in layered magnetic heterostructures have many
commonalities across broad classes of magnetic materials. These include not
only collinear ferromagnets, ferrimagnets, and antiferromagnets, but also more
complex noncollinear spin systems. We develop a general Lagrangian-Rayleigh
approach for studying the role of dissipative torques, which can pump energy
into long-wavelength magnetic dynamics, causing dynamic instabilities. While
the Rayleigh structure of such torques is similar for different magnetic
materials, their consequences depend sensitively on the nature of the order
and, in particular, on whether there is a net magnetic moment. The latter
endows the system with a unipolar switching capability, while magnetically
compensated materials tend to evolve towards limit cycles, at large torques,
with chirality dependent on the torque sign. Apart from the ferromagnetic and
antiferromagnetic cases, we discuss ferrimagnets, which display an intricate
competition between switching and limit cycles. As a simple case for
compensated noncollinear order, we consider isotropic spin glasses, as well as
a scenario of their coexistence with a collinear magnetic order.",2010.15994v1
2020-10-19,Learning phase transitions in ferrimagnetic GdFeCo alloys,"We present results on the identification of phase transitions in
ferrimagnetic GdFeCo alloys using machine learning. The approach for finding
phase transitions in the system is based on the `learning by confusion' scheme,
which allows one to characterize phase transitions using a universal $W$-shape.
By applying the `learning by confusion' scheme, we obtain 2D $W$-a shaped
surface that characterizes a triple phase transition point of the GdFeCo alloy.
We demonstrate that our results are in the perfect agreement with the procedure
of the numerical minimization of the thermodynamical potential, yet our
machine-learning-based scheme has the potential to provide a speedup in the
task of the phase transition identification.",2010.16237v2
2020-10-31,Facet-dependent magnon-polarons in epitaxial ferrimagnetic Fe3O4 thin films,"Magnon-polarons are coherently mixed quasiparticles that originate from the
strong magnetoelastic coupling of lattice vibrations and spin waves in
magnetic-ordered materials. Recently, magnon-polarons have attracted a lot of
attention since they provide a powerful tool to manipulate magnons, which is
essential for magnon-based spintronic devices. In this work, we report the
experimental observation of facet-dependent magnon-polarons in epitaxial
ferrimagnetic Fe3O4 thin films via spin Seebeck effect measurement. The
critical magnetic fields for the magnon-polarons in the (110)- and
(100)-oriented Fe3O4 films are 1.5 T and 1.8 T, respectively, which arises from
the different phonon velocities along the [110] and [100] directions. As the
temperature decreases, the magnon-polarons-enhanced spin Seebeck voltage
decreases in both (110)- and (100)-oriented Fe3O4 films, which could be
attributed to the enhanced magnon-polarons scattering at elevated temperatures.
This work demonstrates the crystal structure engineering in epitaxial magnetic
films as a promising route to manipulate the magnon-polarons for future magnon
spintronic applications.",2011.00195v1
2020-11-19,Novel interpretation of recent experiments on the dynamics of domain walls along ferrimagnetic strips,"Domain wall motion along ferrimagnets is evaluated using micromagnetic
simulations and a collective-coordinates model, both considering two
sublattices with independent parameters. Analytical expressions are derived for
strips on top of either a heavy metal or a substrate with negligible
interfacial Dzyaloshinskii-Moriya Interaction. The work focuses its findings in
this latter case, with a field-driven domain wall motion depicting precessional
dynamics which become rigid at the angular momentum compensation temperature,
and a current-driven dynamics presenting more complex behavior, depending on
the polarization factors for each sublattice. Importantly, our analyses provide
also novel interpretation of recent evidence on current-driven domain wall
motion, where walls move either along or against the current depending on
temperature. Besides, our approach is able to substantiate the large
non-adiabatic effective parameters found for these systems.",2011.09736v1
2021-02-11,Defect-driven ferrimagnetism and hidden magnetization in MnBi$_2$Te$_4$,"MnBi$_2$Te$_4$ (MBT) materials are promising antiferromagnetic topological
insulators where field driven ferromagnetism is predicted to cause a transition
between axion insulator and Weyl semimetallic states. However, the presence of
antiferromagnetic coupling between Mn/Bi antisite defects and the main Mn layer
can reduce the low-field magnetization, and it has been shown that such defects
are more prevalent in the structurally identical trivial magnetic insulator
MnSb$_2$Te$_4$ (MST). We use high-field magnetization measurements to show that
the magnetization of MBT and MST occur in stages and full saturation requires
fields of~$\sim$~60 Tesla. As a consequence, the low-field magnetization
plateau state in MBT, where many determinations of quantum anomalous Hall state
are studied, actually consists of ferrimagnetic septuple blocks containing both
a uniform and staggered magnetization component.",2102.05797v2
2021-03-04,Strange electrical transport: Colossal magnetoresistance via avoiding fully polarized magnetization in ferrimagnetic insulator Mn3Si2Te6,"Colossal magnetoresistance is of great fundamental and technological
significance and exists mostly in the manganites and a few other materials.
Here we report colossal magnetoresistance that is starkly different from that
in all other materials. The stoichiometric Mn3Si2Te6 is an insulator featuring
a ferrimagnetic transition at 78 K. The resistivity drops by 7 orders of
magnitude with an applied magnetic field above 9 Tesla, leading to an
insulator-metal transition at up to 130 K. However, the colossal
magnetoresistance occurs only when the magnetic field is applied along the
magnetic hard axis and is surprisingly absent when the magnetic field is
applied along the magnetic easy axis where magnetization is fully saturated.
The anisotropy field separating the easy and hard axes is 13 Tesla, unexpected
for the Mn ions with nominally negligible orbital momentum and spin-orbit
interactions. Double exchange and Jahn-Teller distortions that drive the
hole-doped manganites do not exist in Mn3Si2Te6. The phenomena fit no existing
models, suggesting a unique, intriguing type of electrical transport.",2103.02764v1
2021-06-02,Ultrafast demagnetization in NiCo2O4 thin films probed by time-resolved microscopy,"Using a time-resolved magneto-optical Kerr effect (TR-MOKE) microscope, we
observed ultrafast demagnetization of inverse-spinel-type NiCo2O4 (NCO)
epitaxial thin films of the inverse spinel type ferrimagnet NCO with
perpendicular magnetic anisotropy. This microscope uses a pump-probe method,
where the sample is pumped at 1030 nm, and magnetic domain images are acquired
via MOKE microscopy at 515 nm (the second harmonic). We successfully observed
the dynamics of the magnetic domain of the NCO thin film via laser irradiation,
and obtained a demagnetization time constant of approximately 0.4 ps. This time
constant was significantly smaller than the large time constants reported for
other half-metallic oxides. These results, combined with the results of our
x-ray photoemission spectroscopy study, indicate that this NCO thin film is a
ferrimagnetic metal whose electronic structure deviates from the theoretically
predicted half-metallic one.",2106.01026v2
2021-06-15,Magnetic properties and phase diagrams of the ferrimagnetic triangular nanotube with core-shell structure: A Monte Carlo study,"Monte Carlo simulation has been employed to investigate the magnetic
properties and phase diagrams of ferrimagnetic mixed-spin (1/2, 1) triangular
Ising nanotube with core-shell structure. In particular, the effect of the
exchange couplings and the temperature on the magnetic and thermodynamic
properties, hysteresis loops as well as the compensation temperature have been
discussed in detail. Moreover, the effects of the single-ion anisotropy, as
well as external magnetic field, have been examined. The threshold values of
the exchange couplings and single-ion anisotropy have been found, determining
whether the system exhibits a compensation temperature. We have found that the
appearance of the compensation temperature is strongly linked with the system
parameters. Moreover, we have obtained the double and triple hysteresis loops
for certain physical parameters in the considered magnetic system.",2106.08397v1
2021-06-17,Epitaxial growth and magnetic characterization of EuSe thin films with various crystalline orientations,"We report different growth modes and corresponding magnetic properties of
thin EuSe films grown by molecular beam epitaxy on BaF2, Pb1-xEuxSe, GaAs, and
Bi2Se3 substrates. We show that EuSe growth predominantly in (001) orientation
on GaAs(111) and Bi2Se3, but along (111) crystallographic direction on BaF2
(111) and Pb1-xEuxSe (111). High-resolution transmission electron microscopy
measurements reveal an abrupt and highly crystalline interface for both (001)
and (111) EuSe films. In agreement with previous studies, ordered magnetic
phases include antiferromagnetic, ferrimagnetic, and ferromagnetic phases. In
contrast to previous studies, we found strong hysteresis for the
antiferromagnetic-ferrimagnetic transition. An ability to grow epitaxial films
of EuSe on Bi2Se3 and of Bi2Se3 on EuSe enables further investigation of
interfacial exchange interactions between various phases of an insulating
metamagnetic material and a topological insulator.",2106.09771v1
2021-07-01,New type of half-metallic fully compensated ferrimagnet,"Half-metallic fully compensated ferrimagnets (HM-FCFMs), a special class of
half-metals exhibiting zero magnetization at absolute zero, are promising
candidates for next-generation spintronics applications. For over 25 years,
theoretical studies have been conducted to realize HM-FCFM materials for
practical applications. Herein, we experimentally demonstrate a NiAs-type
hexagonal-structured (CrFe)S compound that could serve as an HM-FCFM material.
It has a half-metallic nature, with 100% spin-polarized Fermi surfaces and zero
magnetization. Further, the magnetization shows a linear behavior as a function
of the magnetic field below the compensation temperature of around 200 K, with
high magnetic coercivity of 38 kOe at 300 K. These magnetic features are
expected to contribute to a quantum leap in the application of HM-FCFM layers
in spintronics devices.",2107.00258v1
2021-07-12,Large anomalous Nernst effect in non-crystalline Gd-Fe ferrimagnetic alloy films for flexible thermoelectric applications,"The anomalous Nernst effect (ANE), a heat-charge conversion mechanism based
on a magnetic metal, has been extensively studied for application in thin
thermoelectric devices. The low magnetization and fabrication at room
temperature are important for flexible ANE thermoelectric devices on plastic
substrates. Therefore, we investigated the ANE in ferrimagnetic GdxFe100-x
films with low magnetization in this study by systematically varying the Gd
composition x. Although the Gd33Fe67 film with a Gd composition close to
magnetic compensation composition exhibited very low magnetization, an ANE
coefficient |S_ANE| of 2.13 uV/K was obtained, which is close to the highest
value reported thus far. Finally, we demonstrated the ANE in a Gd33Fe67 film
deposited on a flexible sheet. A sufficient ANE voltage was obtained while
maintaining the flexibility of the sample, indicating the potential application
of this material in thermoelectric devices exploiting the ANE of Gd-Fe films.",2107.05215v2
2021-08-09,Phase diagram of CeSb$_2$ from magnetostriction and magnetization measurements: Evidence for ferrimagnetic and antiferromagnetic states,"Cerium diantimonide (CeSb$_2$) is one of a family of rare earth based
magnetic materials that exhibit metamagnetism, enabling control of the magnetic
ground state through an applied magnetic field. At low temperatures, CeSb$_2$
hosts a rich phase diagram with multiple magnetically ordered phases for many
of which the order parameter is only poorly understood. In this paper, we
report a study of its metamagnetic properties by Scanning Tunneling Microscopy
(STM) and magnetization measurements. We use STM measurements to characterize
the sample magnetostriction with sub-picometer resolution from magnetic field
and temperature sweeps. This allows us to directly assess the bulk phase
diagram as a function of field and temperature and relate spectroscopic
features from tunneling spectroscopy to bulk phases. Our magnetostriction and
magnetisation measurements indicate that the low temperature ground state at
zero field is ferrimagnetic. Quasiparticle interference mapping shows evidence
for a reconstruction of the electronic structure close to the Fermi energy upon
entering the magnetically ordered phase.",2108.04245v1
2021-09-04,"Anomalous Hall effect in ferrimagnetic metal RMn6Sn6 (R = Tb, Dy, Ho) with clean Mn kagome lattice","Kagome lattice, made of corner-sharing triangles, provides an excellent
platform for hosting exotic topological quantum states. Here we systematically
studied the magnetic and transport properties of RMn6Sn6 (R = Tb, Dy, Ho) with
clean Mn kagome lattice. All the compounds have a collinear ferrimagnetic
structure with different easy axis at low temperature. The low-temperature
magnetoresistance (MR) is positive and has no tendency to saturate below 7 T,
while the MR gradually declines and becomes negative with the increasing
temperature. A large intrinsic anomalous Hall conductivity about 250
{\Omega}-1cm-1, 40 {\Omega}-1cm-1, 95 {\Omega}-1cm-1 is observed for TbMn6Sn6,
DyMn6Sn6, HoMn6Sn6, respectively. Our results imply that RMn6Sn6 system is an
excellent platform to discover other intimately related topological or quantum
phenomena and also tune the electronic and magnetic properties in future
studies.",2109.01866v1
2021-09-09,Adjustable 3D magnetic configuration in ferrimagnetic multilayers with competing interactions visualized by soft X-ray vector tomography,"Soft X-ray magnetic vector tomography has been used to visualize with
unprecedented detail and solely from experimental data the 3D magnetic
configuration of a ferrimagnetic Gd12Co88/Nd17Co83/Gd24Co76 multilayer with
competing anisotropy, exchange and magnetostatic interactions at different
depths. The trilayer displays magnetic stripe domains, arranged in a chevron
pattern, which are imprinted from the central Nd17Co83 into the bottom Gd12Co88
layer with a distorted closure domain structure across the thickness. Near the
top Gd24Co76 layer, local exchange springs with out-of-plane magnetization
reversal, modulated ripple patterns and magnetic vortices and antivortices
across the thickness are observed. The detailed analysis of the magnetic
tomogram shows that the effective strength of the exchange spring at the
NdCo/GdCo interface can be finely tuned by GdxCo1-x composition and anisotropy
(determined by sample fabrication) and in-plane stripe orientation
(adjustable), demonstrating the capability of 3D magnetic visualization
techniques in magnetic engineering research.",2109.04064v1
2021-09-21,Influence of a spatial anisotropy on presence of the intermediate one-half magnetization plateau of a spin-1/2 Ising-Heisenberg branched chain,"A spin-1/2 Ising-Heisenberg branched chain constituted by regularly
alternating Ising spins and Heisenberg dimers involving an additional side
branching is exactly solved in a magnetic field by the transfer-matrix method.
The spin-1/2 Ising-Heisenberg branched chain involves two different Ising and
one Heisenberg coupling constants. The overall ground-state phase diagram is
formed by three different ground states emergent depending on a mutual
interplay between the magnetic field and three considered coupling constants:
the modulated quantum antiferromagnetic phase, the quantum ferrimagnetic phase,
and the classical ferromagnetic phase. It is shown that the interaction
anisotropy connected to two different Ising coupling constants substantially
influences a breakdown of the intermediate one-half magnetization plateau,
which represents a macroscopic manifestation of the quantum ferrimagnetic
phase.",2109.10026v1
2021-10-07,Multitude of Topological Phase Transitions in Bipartite Dice and Lieb Lattices with Interacting Electrons and Rashba Coupling,"We report the results of a Hartree-Fock study applied to interacting
electrons moving in two different bipartite lattices: the dice and the Lieb
lattices, at half-filling. Both lattices develop ferrimagnetic order in the
phase diagram $U$-$\lambda$, where $U$ is the Hubbard onsite repulsion and
$\lambda$ the Rashba spin-orbit coupling strength. Our main result is the
observation of an unexpected multitude of topological phases for both lattices.
All these phases are ferrimagnetic, but they differ among themselves in their
set of six Chern numbers (six numbers because the unit cells have three atoms).
The Chern numbers $|C|$ observed in our study range from 0 to 3, showing that
large Chern numbers can be obtained by the effect of electronic correlations,
adding to the recently discussed methodologies to increase $|C|$ based on
extending the hopping range in tight-binding models, using sudden quenches, or
photonic crystals, all without including electronic interactions.",2110.03813v2
2021-10-12,Manipulating Ferrimagnets by Fields and Currents,"Ferrimagnets (FIMs) can function as high-frequency antiferromagnets while
being easy to detect as ferromagnets, offering unique opportunities for
ultrafast device applications. While the physical behavior of FIMs near the
compensation point has been widely studied, there lacks a generic understanding
of FIMs where the ratio of sublattice spins can vary freely between the
ferromagnetic and antiferromagnetic limits. Here we investigate the physical
properties of a model two-sublattice FIM manipulated by static magnetic fields
and current-induced torques. By continuously varying the ratio of sublattice
spins, we clarify how the dynamical chiral modes in an FIM are intrinsically
connected to their ferro- and antiferromagnetic counterparts, which reveals
unique features not visible near the compensation point. In particular, we find
that current-induced torques can trigger spontaneous oscillation of the
terahertz exchange mode. Compared with its realization in antiferromagnets, a
spin-torque oscillator using FIMs not only has a reduced threshold current
density but also can be self-stabilized, obviating the need for dynamic
feedback.",2110.06204v3
2021-10-22,Ultra-low energy threshold engineering for all-optical switching of magnetization in dielectric-coated Co/Gd based synthetic-ferrimagnet,"A femtosecond laser pulse is able to switch the magnetic state of a 3d-4f
ferrimagnetic material on a pico-second time scale. Devices based on this
all-optical switching (AOS) mechanism are competitive candidates for ultrafast
memory applications. However, a large portion of the light energy is lost by
reflection from the metal thin film as well as transmission to the substrate.
In this paper, we explore the use of dielectric coatings to increase the light
absorption by the magnetic metal layer based on the principle of constructive
interference. We experimentally show that the switching energy oscillates with
the dielectric layer thickness following the light interference profile as
obtained from theoretical calculations. Furthermore, the switching threshold
fluence can be reduced by at least $80\%$ to 0.6 mJ/cm$^2$ using two dielectric
SiO$_2$ layers sandwiching the metal stack, which scales to 15 fJ of incident
energy for a cell size of $50^2$ nm$^2$.",2110.12063v1
2021-12-13,Origins of transverse voltages generated by applied thermal gradients and applied electric fields in ferrimagnetic-insulator/heavy-metal bilayers,"We compare thermal-gradient-driven transverse voltages in
ferrimagnetic-insulator/heavy-metal bilayers (Tm3Fe5O12/W and Tm3Fe5O12/Pt) to
corresponding electrically-driven transverse resistances at and above room
temperature. We find for Tm3Fe5O12/W that the thermal and electrical effects
can be explained by a common spin-current detection mechanism, the physics
underlying spin Hall magnetoresistance (SMR). However, for Tm3Fe5O12/Pt the
ratio of the electrically-driven transverse voltages (planar Hall
signal/anomalous Hall signal) is much larger than the ratio of corresponding
thermal-gradient signals, a result which is very different from expectations
for a SMR-based mechanism alone. We ascribe this difference to a
proximity-induced magnetic layer at the Tm3Fe5O12/Pt interface.",2112.06591v2
2021-12-24,Three-dimensional ferrimagnetic ground state of triangular-lattice system Ca3Co2O6,"High temperature one-dimensional (1D) ferromagnetic (FM) chains in Ca3Co2O6
spin system are subjected to a magnetic field and temperature induced first
order phase transition (FOPT) to 3D ferrimagnetic (FIM) ground state with
decrease in temperature (T). Weak-FM interaction of third nearest-neighbor(nn)
interchain removes the frustration effect arising from antiferromagnetic (AFM)
interactions of first-nn and second-nn interchains in the underlying
triangular-lattice resulting a 3D FIM ordering of 1D FM chains at low T.
However, hindered kinetics of FOPT partially masks this tranformation giving
rise to coexistence of non-interacting 1D FM chains with 3D-FIM state at low-T.
The existence of all these couplings is further confirmed here by random
substitution of S = 5/2 magnetic-impurity into the spin chain of original
system. It reveals weakening of FM interactions of both intrachain and third-nn
surrounding chains respectively without significant modulation in the AFM
coupling of first-nn and second-nn interchains. Thus, influence of AFM
interactions is enhanced as compared to effective FM coupling with increase of
S = 5/2 impurity content resulting instability of 3D long-range FIM state at
low-T.",2112.13080v1
2022-01-06,Large Magnetic-Field-Induced Strain at the Spin-Reorientation Transition in the A-Site Ordered Spinel Oxide LiFeCr4O8,"Sintered samples of a spinel oxide LiFeCr4O8, where Cr3+ and Fe3+ ions have
localized moments, were found to show a large magnetic-field-induced volume
increase approaching 500 ppm by applying a magnetic field of 9 T. This large
volume increase appeared only at around 30 K. At 30 K, a spin-reorientation
transition from ferrimagnetic to conical order occurs, giving rise to this
large volume increase. The coexistence of ferrimagnetic and conical phases at
this transition was found to be important, suggesting that such a large
magnetic-field-induced volume change can be realized at various magnetic
transitions in localized magnets with strong spin-lattice coupling.",2201.01897v1
2022-01-15,Physical Nature of Magnon Spin Seebeck Effect in Ferrimagnetic Insulators,"The spin Seebeck effect (SSE) in ferrimagnetic insulators (FMI) provides a
simple method of using heat to manipulate magnons, which could be used as
carriers of information and energy conversion. However, a theory that can
quantitively interpret experimental results is still lacking. In this paper, we
develop a transport theory of magnons in FMI at low temperatures by combining
the macroscopic Boltzmann equation with microscopic quantum scattering theory.
It is found that the scattering of magnons is dominated by phonons rather than
magnons, and the relaxation time of magnon is inversely proportional to the
cube of temperature. At extremely low temperature region, the magnon enters the
ballistic transport process. In addition, we also derive the linear spatial
distribution of the transverse SSE signal with sample position. All the
theoretical results are in excellent agreement with the experimental data.",2201.05806v1
2022-02-01,Ferrimagnetically ordered states in the Hubbard model on the hexagonal golden-mean tiling,"We study magnetic properties of the half-filled Hubbard model on the
two-dimensional hexagonal golden-mean tiling. We find that the vertex model of
the tiling is bipartite, with a sublattice imbalance of $\sqrt{5}/(6\tau^3)$
(where $\tau$ is the golden mean), and that the non-interacting tight-binding
model gives macroscopically degenerate states at $E=0$. We clarify that each
sublattice has specific types of confined states, which in turn leads to an
interesting spatial pattern in the local magnetizations in the weak coupling
regime. Furthermore, this allows us to analytically obtain the lower bound on
the fraction of the confined states as $(\tau+9)/(6\tau^6)\sim 0.0986$, which
is conjectured to be the exact fraction. These results imply that a
ferrimagnetically ordered state is realized even in the weak coupling limit.
The introduction of the Coulomb interaction lifts the macroscopic degeneracy at
the Fermi level, and induces finite staggered magnetization as well as uniform
magnetization. Likewise, the spatial distribution of the magnetizations
continuously changes with increasing interaction strength. The crossover
behavior in the magnetically ordered states is also addressed in terms of the
perpendicular space analysis.",2202.00205v1
2022-02-09,Exchange-biased topological transverse thermoelectric effects in a Kagome ferrimagnet,"Kagome metal TbMn6Sn6 was recently discovered to be a ferrimagnetic
topological Dirac material by scanning tunneling microscopy/spectroscopy
measurements. Here, we report the observation of large anomalous Nernst effect
and anomalous thermal Hall effect in this compound. The anomalous transverse
transport is consistent with the Berry curvature contribution from the massive
Dirac gaps in the 3D momentum space as demonstrated by our first-principles
calculations. Furthermore, the transverse thermoelectric transport exhibits
asymmetry with respect to the applied magnetic field, i.e., an exchange-bias
behavior. Together, these features place TbMn6Sn6 as a promising system for the
outstanding thermoelectric performance based on anomalous Nernst effect.",2202.04484v1
2022-03-08,Coupling between improper ferroelectricity and ferrimagnetism in hexagonal ferrites,"Antisymmetric Dzyaloshinskii-Moriya (DM) interactions generating from the
spin-orbit coupling induce various fascinating properties, like magnetoelectric
(ME) effect, weak ferromagnetism and non-trivial topological spin textures like
skyrmions, in real materials. Compared to their symmetric isotropic exchange
counterpart, these interactions are generally of a weaker order of strength,
creating modest twisting in the spin structure which results in weak
ferromagntism or weak linear ME effect. Our proposed two-sublattice model, in
contrast, predicts a hitherto unobserved, charge ordered non-collinear
ferrimagnetic behavior with a considerably high magnetization $\textbf{M}$
coexisting with a ferroelectric (FE) order with an electric polarization
$\textbf{P}$ and a strong cross coupling between them which is primarily driven
by the inter-sublattice DM interactions. The key to realize these effects is
the coupling between these microscopic interactions and the FE primary order
parameter. We predict microscopic mechanisms to achieve electric field
$\textbf{E}$ induced spin-reorientation transitions and 180$^{\circ}$ switching
of the direction of $\textbf{M}$. This model was realized in the hexagonal
phase of LuFeO$_3$ doped with electrons. This system shows $P \sim$ 15
$\mu$C/cm$^2$, $M \sim$ 1.3 $\mu_B$/Fe and magnetic transition near room
temperature ($\sim$ 290 K). Our theoretical results are expected to stimulate
further quest for energy-efficient routes to control magnetism for spintronics
applications.",2203.03841v1
2022-04-10,Unveiling a Pump-Induced Magnon Mode via its Strong Interaction with Walker Modes,"We observe a power-dependent anticrossing of Walker spin-wave modes under
microwave pumping when a ferrimagnet is placed in a microwave waveguide that
does not support any discrete photon mode. We interpret this unexpected
anticrossing as the generation of a pump-induced magnon mode that couples
strongly to the Walker modes of the ferrimagnet. This anticrossing inherits an
excellent tunability from the pump, which allows us to control the anticrossing
via the pump power, frequency, and waveform. Further, we realize a remarkable
functionality of this anticrossing, namely, a microwave frequency comb, in
terms of the nonlinear interaction that mixes the pump and probe frequencies.
Such a frequency comb originates from the magnetic dynamics and thereby does
not suffer from the charge noise. The unveiled hybrid magnonics driven away
from its equilibrium enriches the utilization of anticrossing for coherent
information processing.",2204.04590v2
2022-05-24,Steady entangled-state generation via cross-Kerr effect in a ferrimagnetic crystal,"For solid-state spin systems, the collective spin motion in a single crystal
embodies multiple magnetostatic modes. Recently, it was found that the
cross-Kerr interaction between the higher-order magnetostatic mode and the
Kittel mode introduces a new operable degree of freedom. In this work, we
propose a scheme to entangle two magnon modes via the cross-Kerr nonlinearity
when the bias field is inhomogeneous and the system is driven. Quantum
entanglement persists at the steady state, as demonstrated by numerical results
using experimentally feasible parameters. Furthermore, we also demonstrate that
entangled states can survive better in the system where self-Kerr and
cross-Kerr nonlinearities coexist. Our work provides insights and guidance for
designing experiments to observe entanglement between different degrees of
freedom within a single ferrimagnetic crystal. Additionally, it may stimulate
potential applications in quantum information processing using spintronic
devices.",2205.11865v1
2022-06-17,Theory of ultrafast magnetization of non-magnetic semiconductors with localized conduction bands,"The magnetization of a non-magnetic semiconductor by femtosecond light pulses
is crucial to achieve an all-optical control of the spin dynamics in materials
and to develop faster memory devices. However, the conditions for its detection
are largely unknown. In this work we identify the criteria for the observation
of ultrafast magnetization and critically discuss the difficulties hindering
its experimental detection. We show that ultrafast magnetization of a non
magnetic semiconductor can be observed in compounds with very localized
conduction band states and more delocalized valence bands, such as in the case
of a p-d charge transfer gap. By using constrained and time dependent density
functional theory simulations, we demonstrate that a transient ferrimagnetic
state can be induced in diamagnetic semiconductor V2O5 via ultrafast pulses at
realistic fluences. The ferrimagnetic state has opposite magnetic moments on
vanadium (conduction) and oxygen (valence) states. Our methodology outruns the
case of V2O5 as it identifies the key requirements for a computational
screening of ultrafast magnetism in non-magnetic semiconductors.",2206.08624v1
2022-08-02,Finite-frequency spin conductance of a ferro-/ferrimagnetic-insulator|normal-metal interface,"The interface between a ferro-/ferrimagnetic insulator and a normal metal can
support spin currents polarized collinear with and perpendicular to the
magnetization direction. The flow of angular momentum perpendicular to the
magnetization direction (""transverse"" spin current) takes place via spin torque
and spin pumping. The flow of angular momentum collinear with the magnetization
(""longitudinal"" spin current) requires the excitation of magnons. In this
article we extend the existing theory of longitudinal spin transport [Bender
and Tserkovnyak, Phys. Rev. B 91, 140402(R) (2015)] in the zero-frequency
weak-coupling limit in two directions: We calculate the longitudinal spin
conductance non-perturbatively (but in the low-frequency limit) and at finite
frequency (but in the limit of low interface transparency). For the
paradigmatic spintronic material system YIG|Pt, we find that non-perturbative
effects lead to a longitudinal spin conductance that is ca. 40% smaller than
the perturbative limit, whereas finite-frequency corrections are relevant at
low temperatures < 100 K only, when only few magnon modes are thermally
occupied.",2208.01420v1
2022-08-08,Size-dependent mobility of skyrmions beyond pinning in ferrimagnetic GdCo thin films,"Magnetic skyrmions are swirling magnetic textures that can be efficiently
driven with spin-orbit torques with a deflected trajectory. However, pinning
slows skyrmions down and alters their trajectory, which prevents a quantitative
comparison to analytical models. Here, we study skyrmions driven by spin-orbit
torques at room temperature in ferrimagnetic GdCo thin films, an amorphous
material with low pinning. Above a sharp current depinning threshold, we
observe a clearly linear velocity increase with current that extrapolates to
zero and a constant deflection angle, reaching high velocities up to 200 m/s.
The mobility increases and the depinning threshold current decreases with the
skyrmion diameter, which we vary using an external magnetic field. An
analytical model based on the Thiele equation quantitatively reproduces these
findings with a single fitting parameter. This validates the linear flow regime
description and shows, in particular, the important role of skyrmion size in
its dynamics.",2208.04384v2
2022-10-11,Self organized criticality of magnetic avalanches in disordered ferrimagnetic material,"We observe multiple step-like jumps in a Dy-Fe-Ga-based ferrimagnetic alloy
in its magnetic hysteresis curve at 2 K. The observed jumps have a stochastic
character with respect to their magnitude and the critical field of occurrence,
and the jumps do not show any temporal effect. The jump size distribution
follows a power law variation indicating the scale invariance nature of the
jumps. We have invoked a simple two-dimensional random bond Ising-type spin
system to model the dynamics. Our computational work can qualitatively
reproduce the jumps and their scale invariant character. It also elucidates
that the flipping of antiferromagnetically coupled Dy and Fe clusters is
responsible for the observed discrete avalanche-like features in the hysteresis
loop. These characteristics indicate that the present phenomenon can be well
described within the realm of self-organized criticality",2210.05183v1
2023-01-24,Ru$_{2-x}$Mn$_{1+x}$Al thin films,"The cubic Heusler alloy Ru$_{2-x}$Mn$_{1+x}$Al is grown in thin film form on
MgO and MgAl$_2$O$_4$ substrates. It is a highly spin-polarised ferrimagnetic
metal, with weak magnetocrystalline anisotropy. Although structurally and
chemically similar to $\text{Mn}_2\text{Ru}_x\text{Ga}$, it does not exhibit
ferrimagnetic compensation, or large magneto galvanic effects. The differences
are attributed to a combination of atomic order and the hybridisation with the
group 13 element Al or Ga. The spin polarisation is around 50 to 60 %. There is
a gap in the density of states just above the Fermi level in fully ordered
compounds.",2301.10148v2
2023-02-17,Entangling ferrimagnetic magnons with an atomic ensemble via opto-magnomechanics,"We show how to prepare macroscopic entanglement between an atomic ensemble
and a large number of magnons in a ferrimagnetic YIG crystal. Specifically, we
adopt an opto-magnomechanical configuration where the magnetostriction-induced
magnomechanical displacement couples to an optical cavity via radiation
pressure, and the latter further couples to an ensemble of two-level atoms that
are placed inside the cavity. We show that by properly driving the cavity and
magnon modes, optomechanical entanglement is created which is further
distributed to the atomic and magnonic systems, yielding stationary
entanglement between atoms and magnons. The atom-magnon entanglement is a
result of the combined effect of opto- and magnomechanical cooling and
optomechanical parametric down-conversion interactions. A competition mechanism
between two mechanical cooling channels is revealed. We further show that
genuine tripartite entanglement of three massive subsystems, i.e., atoms,
magnons and phonons, can also be achieved in the same system. Our results
indicate that the hybrid opto-magnomechanical system may become a promising
system for preparing macroscopic quantum states involving magnons, photons,
phonons and atoms.",2302.08684v2
2023-02-27,Anomalous Nernst effect in a ferrimagnetic nodal-line semiconductor Mn$_3$Si$_2$Te$_6$,"In the ferrimagnetic nodal-line semiconductor Mn$_3$Si$_2$Te$_6$, colossal
magnetoresistance (CMR) arises below $T_\mathrm{c}=78$ K due to the interplay
of magnetism and topological nodal-line fermiology. The Berry curvature
associated with the topological nodal-line is expected to produce an anomalous
Nernst effect. Here, we present sizable anomalous Nernst signal in
Mn$_3$Si$_2$Te$_6$ below $T_\mathrm{c}$. In the low-magnetic-field region where
CMR is most apparent, the scaling ratio between the Nernst signal and
magnetization is significantly enhanced compared to that in conventional
magnetic materials. The enhanced Nernst effect and CMR likely share the same
mechanisms, which are closely linked to the nodal-line topology.",2302.13735v1
2023-04-05,Intrinsic Origin and Enhancement of Topological Responses in Ferrimagnetic Antiperovskite Mn4N,"Using first-principles calculations we investigate the intrinsic origins of
the anomalous Hall effect (AHE) and the anomalous Nernst effect (ANE) in
antiperovskite ferrimagnet Mn4N. We predict that the AHE is significantly
enhanced under both compressive and tensile strain, however, the ANE generally
decreases under epitaxial strain, except for 1% compressive strain. We connect
this behavior to the evolution of the Berry curvature with strain, suggesting
similar strategies for achieving large AHE and ANE changes with modest amounts
of strain. Finally, we find that the non-monotonic characteristics of the AHE
and ANE stem from the formation and movement of new Weyl points at the
periphery of the Brillouin Zone under compressive and tensile strains.",2304.02750v1
2023-04-13,Finite Temperature Dynamics of Spin Solitons with Applications in Thermocouples and Refrigerators,"The exploitation of spin Berry phases to generate emergent fields for
producing miniaturized and high-quality inductors has enjoyed considerable
popularity among proponents of quantum technologies [Nature 586, 202 (2020)}].
Inspired by this breakthrough, we extend its mechanism to spin thermoelectrics
by probing responses of ferrimagnetic domain walls (DWs) to thermal gradients.
Similarly, voltages here stem from DW-spin collective motion, in contrast to
normal electron transport phenomena. We further develop finite-temperature
dynamics to investigate thermoelectric figures of merit and attribute
corresponding quantum superiority to ultrafast spin evolution of ferrimagnetism
with tunable non-Abelian phases. We propose a more likely cause of DW motion
towards hot or cold regions (contrary to conclusions of previous reports) and
verify existence of efficient magnon-momentum transfers. These findings deepen
our understanding of heat-driven DW kinetics and suggest profitable new
directions in an emerging realm of spincaloritronics.",2304.06608v1
2023-04-18,Efficient characteristics of exchange coupling and spin-flop transition in Py/Gd bilayer using anisotropic magnetoresistance,"The interlayer antiferromagnetic coupling rare-earth/transition-metal bilayer
ferrimagnet systems have attracted much attention because they present
variously unusual temperature-and field-dependent nontrivial magnetic states
and dynamics. These properties and the implementation of their applications in
spintronics highly depend on the significant temperature dependence of the
magnetic exchange stiffness constant A. Here, we quantitatively determine the
temperature dependence of magnetic exchange stiffness A_{Py-Gd} and A_{Gd} in
the artificially layered ferrimagnet consisting of a Py/Gd bilayer, using a
measurement of anisotropic magnetoresistance (AMR) of the bilayer thin film at
different temperatures and magnetic fields. The obtained temperature dependence
of A_{Py-Gd} and A_{Gd} exhibit a scaling power law with the magnetization of
Gd. The critical field of spin-flop transition and its temperature dependence
can also be directly obtained by this method. Additionally, the experimental
results are well reproduced by micromagnetic simulations with the obtained
parameters A_{Py-Gd} and A_{Gd}, which further confirms the reliability of this
easily accessible technique.",2304.08858v1
2023-05-02,Magnetic inhomogeneities in the quadruple perovskite manganite [Y$_{2-x}$Mn$_x$]MnMnMn$_4$O$_{12}$,"A combination of competing exchange interactions and substitutional disorder
gives rise to magnetic inhomogeneities in the
[Y$_{2-x}$Mn$_x$]MnMnMn$_4$O$_{12}$ $x = 0.23$ and $x = 0.16$ quadruple
perovskite manganites. Our neutron powder scattering measurements show that
both the $x = 0.23$ and $x = 0.16$ samples separate into two distinct magnetic
phases; below T$_{1}$ = 120 $\pm$ 10 K the system undergoes a transition from a
paramagnetic phase to a phase characterised by short range antiferromagnetic
clusters contained in a paramagnetic matrix, and below T$_{2}$ $\sim$ 65 K, the
system is composed of well correlated long range collinear ferrimagnetic order,
punctuated by short range antiferromagnetic clusters. A sharp increase in the
antiferromagnetic phase fraction is observed below $\sim$ 33 K, concomitant
with a decrease in the ferrimagnetic phase fraction. Our results demonstrate
that the theoretically proposed AFM phase is stabilised in the
[Y$_{2-x}$Mn$_x$]MnMnMn$_4$O$_{12}$ manganites in the presence of dominant B-B
exchange interactions, as predicted.",2305.01804v1
2023-05-25,Random-anisotropy mixed-spin Ising on a triangular lattice,"We have studied the mixed spin-1/2 and 1 Ising ferrimagnetic system with a
random anisotropy on a triangular lattice with three interpenetrating
sublattices $A$, $B$, and $C$. The spins on the sublattices are represented by
$\sigma_{A}$ (states $\pm1/2$), $\sigma_{B}$ (states $\pm1/2$), and $S_{C}$
(states $\pm1$, $0$). We have performed Monte Carlo simulations to obtain the
phase diagram temperature $k_{\text{B}}T/\left|J\right|$ versus the strength of
the random anisotropy $D/\left|J\right|$. The phase boundary between two
ferrimagnetic $FR_{1}$ and $FR_{2}$ phases at lower temperatures are always
first-order for $p<0.25$ and second-order phase transition between the
$FR_{1}$, $FR_{2}$ and the paramagnetic $P$ phases. On the other hand, for
values of $p\gtrapprox0.5$, the phase diagram presents only second-order phase
transition lines.",2305.15866v1
2023-06-02,Ultrafast single-pulse all-optical switching in synthetic ferrimagnetic Tb/Co/Gd multilayers,"In this work, we investigate single-shot all-optical switching (AOS) in
Tb/Co/Gd/Co/Tb multilayers in an attempt to establish AOS in synthetic
ferrimagnets with high perpendicular magnetic anisotropy. In particular, we
study the effect of varying Tb thicknesses to disentangle the role of the two
rare earth elements. Even though the role of magnetic compensation has been
considered to be crucial, we find that the threshold fluence for switching is
largely independent of the Tb content. Moreover, we identify the timescale for
the magnetization to cross zero to be within the first ps after laser
excitation using time-resolved MOKE. We conclude that the switching is governed
mostly by interactions between Co and Gd.",2306.01419v3
2023-08-16,Even-Odd-Layer-Dependent Symmetry Breaking in Synthetic Antiferromagnets,"In this work we examine synthetic antiferromagnetic structures consisting of
two, three, and four antiferromagnetic coupled layers, i.e., bilayers,
trilayers, and tetralayers. We vary the thickness of the ferromagnetic layers
across all structures and, using a macrospin formalism, find that the nearest
neighbor exchange interaction between layers is consistent across all
structures for a given thickness. Our model and experimental results
demonstrate significant differences in how the magnetostatic equilibrium states
of even and odd-layered structures evolve as a function of the external field.
Even layered structures continuously evolve from a collinear antiferromagnetic
state to a spin canted non-collinear magnetic configuration that is
mirror-symmetric about the external field. In contrast, odd-layered structures
begin with a ferrimagnetic ground state; at a critical field, the ferrimagnetic
ground state evolves into a non-collinear state with broken symmetry.
Specifically, the magnetic moments found in the odd-layered samples possess
stable static equilibrium states that are no longer mirror-symmetric about the
external field after a critical field is reached. Our results reveal the rich
behavior of synthetic antiferromagnets.",2308.08684v1
2023-08-28,Coherent Spin-Phonon Coupling in the Layered Ferrimagnet Mn3Si2Te6,"We utilize ultrafast photoexcitation to drive coherent lattice oscillations
in the layered ferrimagnetic crystal Mn3Si2Te6, which significantly stiffen
below the magnetic ordering temperature. We suggest that this is due to an
exchange-mediated contraction of the lattice, stemming from strong
magneto-structural coupling in this material. Additionally, simulations of the
transient incoherent dynamics reveal the importance of spin relaxation channels
mediated by optical and acoustic phonon scattering. Our findings highlight the
importance of spin-lattice coupling in van der Waals magnets and a promising
route for their dynamic optical control through their intertwined electronic,
lattice, and spin degrees of freedom.",2308.14931v1
2023-09-25,Low-temperature giant coercivity in Co$_{6.2}$Ga$_{3.8-x}$Ge$_{x}$ ($x$=2.4 to 3.2),"The observation of giant coercivity exceeding 20 kOe at low temperatures in
several transition-metal-based compounds has attracted significant attention
from a fundamental perspective. This research is also relevant to developing
rare-earth-free permanent magnets, wherein cobalt is one of the primary
elements used. To facilitate easy fabrication, rare-earth-free and Co-based
inorganic bulk magnets that exhibit giant coercivity are highly demanded but
rarely reported. Herein, we report the observation of low-temperature giant
coercivity in polycrystalline metallic Co$_{6.2}$Ga$_{3.8-x}$Ge$_{x}$ ($x$=2.4
to 3.2) with the hexagonal Fe$_{13}$Ge$_{8}$-type structure composed of Kagome
and triangular lattices. As the Ge content $x$ decreases from 3.2, the magnetic
ground state changes from ferrimagnetism to ferromagnetism at $x$=2.6. In the
ferrimagnetic state, we observed a signature of spin frustration arising from
the Kagome and/or triangular lattices of Co atoms. The ferromagnetic ordering
temperatures for the $x$=2.6 and 2.4 samples are 46 K and 60 K, respectively.
The coercive fields rapidly increase upon cooling and reach values of 26 kOe
and 44 kOe in the $x$=2.6 and 2.4 samples, respectively, at 2 K.",2309.14565v1
2023-10-20,Surface-symmetry-driven Dzyaloshinskii--Moriya interaction and canted ferrimagnetism in collinear magnetoelectric antiferromagnet Cr$_2$O$_3$,"Antiferromagnets are normally thought of as materials with compensated
magnetic sublattices. This adds to their technological advantages but
complicates readout of the antiferromagnetic state. We demonstrate
theoretically the existence of a Dzyaloshinskii-Moriya interaction (DMI) which
is determined by the magnetic symmetry classes of Cr$_2$O$_3$ surfaces with an
in-plane magnetic easy axis. The DMI explains a previously predicted
out-of-plane magnetization at the nominally compensated surfaces of chromia,
leading to a surface-localized canted ferrimagnetism. This is in agreement with
magnetotransport measurements and with density functional theory predictions
which further allow us to quantify the strength of DMI. The temperature
dependence of the transversal resistance for these planes shows distinct
behavior in comparison with that of the Cr$_2$O$_3$ $c$ plane, which we
attribute to the influence of DMI. Our work provides a framework to analyze
surface-driven phenomena in antiferromagnets, and motivates the use of
nominally compensated chromia surfaces for antiferomagnetic spintronics and
magnonics.",2310.13438v1
2023-12-15,Hyperbolic Bloch points in ferrimagnetic exchange spring,"Bloch points in magnetic materials are attractive entities in view of
magnetic information transport. Here, Bloch point configuration has been
investigated and experimentally determined in a magnetic trilayer
($Gd_{12}Co_{88}/Nd_{17}Co_{83}/Gd_{24}Co_{76}$) with carefully adjusted
composition within the ferrimagnetic $Gd_{x}Co_{1-x}$ alloys in order to
engineer saturation magnetization, exchange length, and interlayer couplings
(ferromagnetic vs antiferromagnetic). X-ray vector magnetic tomography has
allowed us to determine experimentally Bloch point polarity (related to
topological charge) and Bloch point helicity ${\gamma}$ (determined by
magnetostatic energy). At the bottom layer (close to the ferromagnetic
interface), Bloch points adopt a standard circulating configuration with
helicity ${\gamma}$ close to ${\pi}/2$. Within the top layer (with much lower
saturation magnetization), Bloch points nucleate within a Neel-like exchange
spring domain wall created by the antiferromagnetic coupling and adopt an
uncommon hyperbolic configuration, characterized by much larger helicity
angles. Our results indicate a path for Bloch point engineering in future
applications adjusting material parameters and domain wall characteristics.",2312.09836v1
2023-12-16,Spin-torque nano-oscillator based on two in-plane magnetized synthetic ferrimagnets,"We report the dynamic characterization of the spin-torque-driven in-plane
precession modes of a spin-torque nano-oscillator based on two different
synthetic ferrimagnets: a pinned one characterized by a strong RKKY interaction
which is exchange coupled to an antiferromagnetic layer; and a second one,
non-pinned characterized by weak RKKY coupling. The microwave properties
associated with the steady-state precession of both SyFs are characterized by
high spectral purity and power spectral density. However, frequency dispersion
diagrams of the damped and spin transfer torque modes reveal drastically
different dynamical behavior and microwave emission properties in both SyFs. In
particular, the weak coupling between the magnetic layers of the non-pinned SyF
raises discontinuous dispersion diagrams suggesting a strong influence of mode
crossing. An interpretation of the different dynamical features observed in the
damped and spin torque modes of both SyF systems was obtained by solving
simultaneously, in a macrospin approach, a linearized version of the
Landau-Lifshitz-Gilbert equation including the spin transfer torque term.",2312.10451v2
2024-01-19,Diversity of Ultrafast Spin Dynamics Near the Tricritical Point in a Ferrimagnetic Gd/FeCo Multilayer,"It is found that subtle changes in the external magnetic field and
temperature result in dramatic changes in the ultrafast response of spins to a
femtosecond laser excitation in a ferrimagnetic Gd/FeCo multilayer. A total of
six distinct types of spin dynamics were observed and explained by considering
the spin-flop transition to the noncollinear phase and the concept of a
tricritical point in the $H$-$T$ phase diagram. A particularly interesting type
of dynamics is the exchange-driven reversal. These exchange-driven dynamics
provide new insights into the tricritical point, which is shown to separate two
thermodynamically distinct noncollinear phases with the transition-metal
magnetization pointing on adjacent sides of the anisotropy plane.",2401.10671v1
2024-04-08,Multiple Floquet Chern insulator phases in the spin-charge coupled triangular-lattice ferrimagnet: Crucial roles of higher-order terms in the high-frequency expansion,"We study the effects of photoirradiation with circularly polarized light on
the Dirac half-metal state induced by the ferrimagnetic order in a triangular
Kondo-lattice model. Our analysis based on the Floquet theory reveals that two
types of Floquet Chern insulator phases appear as photoinduced nonequilibrium
steady states and that these two phases can be experimentally detected and
distinguished by measurements of the Hall conductivity. It is elucidated that
these rich nonequilibrium topological phases come from higher-order terms in
the high-frequency expansion called Brillouin-Wigner expansion, which is in
striking contrast to usually discussed Floquet Chern insulator phases
originating from the lowest-order terms of the expansion. So far, the lattice
electron models on simple non-multipartite lattices such as triangular lattices
and square lattices have not been regarded as targets of the Floquet
engineering because the lowest-order terms of the high-frequency expansion for
Floquet effective Hamiltonians cancel each other to vanish in these systems.
Our findings of the Floquet Chern insulator phases in a triangular
Kondo-lattice model are expected to expand the range of potential models and
even materials targeted by the Floquet engineering.",2404.05385v1
2014-04-21,"Re-t2g-splitting-driven semiconductor gaps in ferrimagnetic double perovskite Ca2MReO6 (M=Cr,Fe) from first principles","Motivated by the observation of nonmetallic nature in double perovskite
Ca2CrReO6 and Ca2FeReO6 with high magnetic Curie temperatures of 360 and 522 K,
we systematically investigate the structural, electronic, and magnetic
properties of Ca2MReO6 (M=Cr,Fe) using the full-potential linear augmented
plane wave (FP-LAPW) method within the density functional theory. Our full
optimization confirms the stable ground-state structure with $P2_1/n$ symmetry.
The modified Becke-Johnson (mBJ) exchange potential is used for investigating
electronic structures. Our mBJ calculation shows that they are both
ferrimagnetic semiconductors with semiconductor gaps of 0.38 eV and 0.05 eV,
respectively, in contrast with wrong metallic phases from the generalized
gradient approximation (GGA). The origin of semiconductor gap is due to the
further distortion of ReO$_6$ octahedra caused by John-Teller effect, which
drives the three partially-occupied Re $t_{2g}$ bands split into two
fully-filled bands and one empty band in the minority-spin channel. With the
spin-orbit coupling (SOC) taken into account, the Ca2MReO6 (M=Cr,Fe) shows high
magneto-crystalline anisotropy (MCA) with the magnetic easy axis along
pseudocubic [010] direction, and the total magnetic moments increase by
0.209$\mu_B$ and 0.258$\mu_B$ per formula unit, respectively, due to the strong
SOC effect on Re ion. Although reducing to 0.31 and 0.03 eV, the semiconductor
gaps remain open in spite of the SOC broadening of the Re $t_{2g}$-related
bands. Therefore, our DFT investigation with mBJ has established the correct
ferrimagnetic semiconductor ground state for the double perovskites Ca2MReO6
(M=Cr,Fe). This mechanism, different from that in double perovskite Sr2CrOsO6,
can help understand physical properties of other similar compounds.",1404.5091v2
2020-02-04,Magnetic behavior of a ferro-ferrimagnetic ternary alloy AB$_ρ$C$_{1-ρ}$ with a selective site disorder: the case study of a mixed-spin Ising model on a honeycomb lattice,"Phase transitions, compensation phenomenon and magnetization of a
ferro-ferrimagnetic ternary alloy AB$_{\rho}$C$_{1-\rho}$ composed of three
different kinds of magnetic ions A, B and C with the spin magnitude 1/2, 1 and
3/2 are examined within the framework of a mixed-spin Ising model on a
honeycomb lattice with a selective annealed site disorder on one of its two
sublattices. It is supposed that the first sublattice of a bipartite honeycomb
lattice is formed by the spin-1/2 magnetic ions, while the sites of the second
sublattice are randomly occupied either by the spin-1 magnetic ions with a
probability $\rho$ or the spin-3/2 magnetic ions with a probability $1-\rho$,
both being subject to a uniaxial single-ion anisotropy. The model under
investigation can be exactly mapped into an effective spin-1/2 Ising model on a
triangular lattice through the generalized star-triangle transformation. For a
specific concentration of the spin-1 (spin-3/2) magnetic ions, it is shown that
the ferro-ferrimagnetic version of the studied model may display a compensation
temperature at which the total magnetization vanishes below a critical
temperature. The critical temperature strikingly may also become independent of
the concentration of the randomly mixed spin-1 and spin-3/2 magnetic ions for a
specific value of a uniaxial single-ion anisotropy. The spontaneous magnetic
order may be notably restored at finite temperatures through the
order-by-disorder mechanism above a disordered ground state, which results in
an anomalous temperature dependence of the total magnetization with double
reentrant phase transitions.",2002.01572v1
2020-12-10,Magnetic order and magneto-transport in half-metallic ferrimagnetic Mn$_y$Ru$_x$Ga thin films,"The ruthenium content of half-metallic Mn$_2$Ru$_x$Ga thin films, with a
biaxially-strained inverse Heusler structure, controls the ferrimagnetism that
determines their magnetic and electronic properties. An extensive study of
Mn$_y$Ru$_x$Ga films on MgO (100) substrates with $1.8 \leq y \leq 2.6$ and $x
= 0.5$, 0.7 or 0.9, including crystallographic, magnetic order,
magneto-transport and spin polarisation is undertaken to map specific
composition-dependent properties in this versatile ternary system. A comparison
of experimental densities obtained from X-ray reflectivity with calculated
densities indicates full site occupancy for all compositions, which implies
chemical disorder. All moments lie on the Slater-Pauling plot with slope 1 and
all except $x = 0.5$, $y = 2.2$ exhibit magnetic compensation at \tcmp~below
500~K. The coercivity near \tcmp~exceeds 10~T. Increasing the Mn or Ru content
raises \tcmp, but increasing Ru also decreases the spin polarisation determined
by point contact Andreev reflection. Molecular field theory is used to model
the temperature dependence of the net ferrimagnetic moment and three principal
exchange coefficients are deduced. Marked differences in the shape of anomalous
Hall and net magnetisation hysteresis loops are explained by substantial
canting of the small net moment by up to \SI{40}{\degree} relative to the
$c$-axis in zero field, which is a result of slight non-collinearity of the
Mn$^{4c}$ sublattice moments due to competing intra-sublattice exchange
interactions arising from antisite disorder and excess Mn in the unit cell.
Consequences are reduced spin polarisation and an enhanced intrinsic
contribution to the anomalous Hall effect. The systematic investigation of the
physical properties as a function of $x$ and $y$ will guide the selection of
compositions to meet the requirements for magnonic and spintronic MRG-based
devices.",2012.05736v5
2021-01-14,Intriguing magnetism of the topological kagome magnet TbMn_6Sn_6,"Magnetic topological phases of quantum matter are an emerging frontier in
physics and material science. Along these lines, several kagome magnets have
appeared as the most promising platforms. Here, we explore magnetic
correlations in the transition-metal-based kagome magnet TbMn$_{6}$Sn$_{6}$
using muon spin rotation, combined with local field analysis and neutron
diffraction. Our results show that the system exhibits an out-of-plane
ferrimagnetic structure $P6/mm'm'$ (comprised by Tb and Mn moments) with slow
magnetic fluctuations below $T_{\rm C2}$~=~320~K. These fluctuations exhibit a
slowing down below $T_{\rm C1}^{*}$~${\simeq}$~120~K, and we see the formation
of static patches with ideal out-of-plane order below $T_{\rm
C1}$~${\simeq}$~20~K which grow in a volume with decreasing temperature. The
appearance of the static patches has a similar onset to the interesting
phenomenon such as spin-polarized Dirac dispersion with a large Chern gap and
topological edge states. We further show that the temperature evolution of the
anomalous Hall conductivity (AHC) is strongly influenced by the low temperature
magnetic crossover. Our presented experimental results show that the onset of
the topological electronic properties tied to the Dirac band is promoted only
by true static out-of-plane ferrimagnetic order in TbMn$_{6}$Sn$_{6}$ and is
washed out by the slow magnetic fluctuations above $T_{\rm
C1}$~${\simeq}$~20~K. Remarkably, hydrostatic pressure of 2.1 GPa stabilises
static out-of-plane topological ferrimagnetic ground state in the whole volume
of the sample. Therefore the exciting perspective arises of a magnetic system
in which the topological response can be controlled, and thus explored, over a
wide range of parameters.",2101.05763v2
2020-03-20,"Neutron Diffraction Evidence for Local Spin Canting, Weak Jahn-Teller Distortion, and Magnetic Compensation in Ti$_{1-x}$Mn$_{x}$Co$_2$O$_4$ Spinel","A systematic study using neutron diffraction and magnetic susceptibility are
reported on Mn substituted ferrimagnetic inverse spinel
Ti$_{1-x}$Mn$_{x}$Co$_2$O$_4$ in the temperature interval 1.6 K $\leq$ $T$
$\leq$ 300 K. Our neutron diffraction study reveals cooperative distortions of
the $T$O$_6$ octahedral for all the Jahn-Teller active ions $T$ = Mn$^{3+}$,
Ti$^{3+}$ and Co$^{3+}$, which are confirmed by the X-ray photoelectron
spectroscopy. Two specific compositions ($x$ = 0.2 and 0.4) have been chosen
because of their unique features: noncollinear Yafet-Kittel type ordering, and
weak tetragonal distortion with ${c/a}$ $<$ 1, in which the apical bond length
$d_c$($T_B$-O) is longer than the equatorial $d_{ab}$($T_B$-O) due to the
splitting of the $e_g$ level of Mn$^{3+}$ ions into $d_{x^2-y^2}$ and
$d_{z^2}$. For $x$ = 0.4, the distortion in the $T_B$O$_6$ octahedra is
stronger as compared to $x$ = 0.2 because of the higher content of trivalent
Mn. Ferrimagnetic ordering in $x$ = 0.4 and $x$ = 0.2 sets in at 110.3 and 78.2
K, respectively due to the unequal magnetic moments of cations, where
Ti$^{3+}$, Mn$^{3+}$, and Co$^{3+}$ occupying the octahedral, whereas,
Co$^{2+}$ sits in the tetrahedral site. In addition, weak antiferromagnetic
component could be observed lying perpendicular to the ferrimagnetic component.
The analysis of static and dynamic magnetic susceptibilities combined with the
heat-capacity data reveals a magnetic compensation phenomenon at $T_{COMP}$ =
25.4 K in $x$ = 0.2 and a reentrant spin-glass behaviour in $x$ = 0.4 with a
freezing temperature $\sim$110.1 K. The compensation phenomenon is
characterized by sign reversal of magnetization and bipolar exchange bias
effect below $T_{COMP}$ with its magnitude depending on the direction of
external magnetic field and the cooling protocol.",2003.09308v1
2021-07-16,Intra-unitcell cluster-cluster magnetic compensation and large exchange bias in cubic alloys,"Composite quantum materials are the ideal examples of multifunctional systems
which simultaneously host more than one novel quantum phenomenon in physics.
Here, we present a combined theoretical and experimental study to demonstrate
the presence of an extremely large exchange bias in the range 0.8 T - 2.7 T and
a fully compensated magnetic state (FCF) in a special type of Pt and Ni doped
Mn$_3$In cubic alloy. Here, oppositely aligned uncompensated moments in two
different atomic clusters sum up to zero which are responsible for the FCF
state. Our Density functional theory (DFT) calculations show the existence of
several possible ferrimagnetic configurations with the FCF as the energetically
most stable one. The microscopic origin of the large exchange bias can be
interpreted in terms of the exchange interaction between the FCF background and
the uncompensated ferrimagnetic clusters stabilized due to its negligible
energy difference with respect to the FCF phase. We utilize pulsed magnetic
field up to 60 T and 30 T static field magnetization measurements to confirm
the intrinsic nature of exchange bias in our system. Finally, our Hall effect
measurements demonstrate the importance of uncompensated noncoplanar
interfacial moments for the realization of large EB. The present finding of
gigantic exchange bias in a unique compensated ferrimagnetic system opens up a
direction for the design of novel quantum phenomena for the technological
applications.",2107.07742v1
2022-05-05,Origins of multi-sublattice magnetism and superexchange interactions in double-double perovskite CaMnCrSbO6,"We have deployed density functional theory, Wannier function analysis and
mean-field calculations to investigate the double-double perovskite compound
CaMnCrSbO_{6}. The crystallographically non-equivalent Mn atoms in the unit
cell have tetrahedral and planar oxygen coordinations (labelled as Mn(1) and
Mn(2)), while the Cr atom is in the centre of distorted oxygen octahedron.
While the bulk magnetization and neutron diffraction suggest a simpler
ferrimagnetic order (T_C=49 K) between Mn2+ and Cr3+ spins, the exchange
interactions are more complex than that expected from a two sublattice magnetic
system. The electronic structure calculations yield a ferrimagnetic insulating
ground state even in absence of Hubbard U which persists for a wide range of U.
The Mn(1)-O-Mn(2) (out of plane and in-plane), Mn(1)-O-Cr and Mn(2)-O-Cr
superexchange interactions are found to be anti-ferromagnetic, while the
Cr-O-O-Cr super-superexchange is found to be ferromagnetic. The Mn(2)-O-Cr
superexchange is weaker than the Mn(1)-O-Cr superexchange, thus effectively
resulting in ferrimagnetism. From a simple 3-site Hubbard model, we derived
expressions for the antiferromagnetic superexchange strength J_AFM and the
weaker ferromagnetic J_FM. The relative strengths of JAFM for the various
superexchange interactions are in agreement with those obtained from DFT. The
expression for Cr-O-O-Cr super-superexchange strength (J_SS), which is derived
considering a 4-site Hubbard model, predicts a ferromagnetic exchange in
agreement with DFT. Finally, our mean field calculations reveal that assuming a
set of four magnetic sub-lattice for Mn2+ spins and a single magnetic
sublattice for Cr3+ spins yields a much improved T_C, while a simple two
magnetic sublattice model yields a much higher T_C.",2205.02452v2
2022-05-06,Tuning the dynamics of chiral domain walls of ferrimagnetic films with the magneto-ionic effect,"The manipulation of magnetism with a gate voltage is expected to lead the way
towards the realization of energy-efficient spintronics devices and
high-performance magnetic memories. Exploiting magneto-ionic effects under
micro-patterned electrodes in solid-state devices adds the possibility to
modify magnetic properties locally, in a non-volatile and reversible way.
Tuning magnetic anisotropy, magnetization and Dzyaloshinskii-Moriya interaction
allows modifying at will the dynamics of non trivial magnetic textures such as
skyrmions and chiral domain walls in magnetic race tracks. In this work, we
illustrate efficient magneto-ionic effects in a ferrimagnetic Pt/Co/Tb stack
using a ZrO2 thin layer as a solid state ionic conductor. When a thin layer of
terbium is deposited on top of cobalt, it acquires a magnetic moment that
aligns antiparallel to that of cobalt, reducing the effective magnetization.
Below the micro-patterned electrodes, the voltage-driven migration of oxygen
ions in a ZrO2 towards the ferrimagnetic stack partially oxidizes the Tb layer,
leading to the local variation not only of the spontaneous magnetization, but
also of the effective magnetic anisotropy and of the Dzyaloshinskii-Moriya
interaction. This leads to a huge increase of the domain wall velocity, which
varies from 10 m/s in the pristine state to 250 m/s after gating. This
non-volatile and reversible tuning of the domain wall dynamics may lead to
applications to reprogrammable magnetic memories or other spintronic devices.",2205.03158v1
2024-03-18,Tuning of the ultrafast demagnetization by ultrashort spin polarized currents in multi-sublattice ferrimagnets,"Femtosecond laser pulses can be used to induce ultrafast changes of the
magnetization in magnetic materials. Several microscopic mechanisms have been
proposed to explain the observations, including the transport of ultrashort
spin-polarized hot-electrons (SPHE). Such ultrafast spin currents find growing
interest because of the recent challenges in ultrafast spintronics however they
are only poorly characterized. One of the key challenges is to characterize the
spin-polarized ultrafast currents and the microscopic mechanisms behind SPHE
induced manipulation of the magnetization, especially in the case of
technologically relevant ferrimagnetic alloys. Here, we have used a combined
approach using time- and element-resolved X-ray magnetic circular dichroism and
theoretical calculations based on atomistic spin-dynamics simulations to
address the ultrafast transfer of the angular momentum from spin-polarized
currents into ferrimagnetic Fe74Gd26 films and the concomitant reduction of
sub-lattice magnetization. Our study shows that using a Co/Pt multilayer as a
polarizer in a spin-valve structure, the SPHE drives the demagnetization of the
two sub-lattices of the Fe74Gd26 film. This behaviour is explained based on two
physical mechanisms, i.e., spin transfer torque and thermal fluctuations
induced by the SPHE. We provide a quantitative description of the heat transfer
of the ultrashort SPHE pulse to the Fe74Gd26 films, as well as the degree of
spin-polarization of the SPHE current density responsible for the observed
magnetization dynamics. Our work finally characterizes the spin-polarization of
the SPHEs revealing unexpected opposite spin polarization to the Co
magnetization, explaining our experimental results.",2403.11739v2
1995-09-26,Global Bethe lattice consideration of the spin-1 Ising model,"The spin-1 Ising model with bilinear and biquadratic exchange interactions
and single-ion crystal field is solved on the Bethe lattice using exact
recursion equations. The general procedure of critical properties investigation
is discussed and full set of phase diagrams are constructed for both positive
and negative biquadratic couplings. In latter case we observe all remarkable
features of the model, uncluding doubly-reentrant behavior and ferrimagnetic
phase. A comparison with the results of other approximation schemes is done.",9509158v2
1996-10-14,Low Temperature Properties of Quantum Antiferromagnetic Chains with Alternating Spins S=1 and 1/2,"We study the low-temperature properties of S=1 and 1/2 alternating spin
chains with antiferromagnetic nearest-neighbor exchange couplings using
analytical techniques as well as a quantum Monte Carlo method. The spin-wave
approach predicts two different low-lying excitations, which are gapped and
gapless, respectively. The structure of low-lying levels is also discussed by
perturbation theory in the strength of the Ising anisotropy. These analytical
findings are compared with the results of quantum Monte Carlo calculations and
it turns out that spin-wave theory well describes the present system. We
conclude that the quantum ferrimagnetic chain exhibits both ferromagnetic and
antiferromagnetic aspects.",9610109v1
1997-03-14,The ground state of the Kondo model with large spin,"In this paper, we prove that the ground state of the Kondo model with large
spin is nondegenerate, apart from a SU(2) spin degeneracy in the case of half
filling. The ground state spin is found for the system, and the energy level
orderings are discussed. Finally, the existence of ferrimagnetism in some cases
is proved.",9703145v1
1999-05-15,Critical Behavior of Anisotropic Heisenberg Mixed-Spin Chains in a Field,"We numerically investigate the critical behavior of the spin-(1,1/2)
Heisenberg ferrimagnet with anisotropic exchange coupling in a magnetic field.
A quantized magnetization plateau as a function of the field, appearing at a
third of the saturated magnetization, is stable over whole the
antiferromagnetic coupling region. The plateau vanishes in the ferromagnetic
coupling region via the Kosterlitz-Thouless transition. Comparing the quantum
and classical magnetization curves, we elucidate what are essential quantum
effects.",9905224v1
1999-05-21,Breakdown of a Magnetization Plateau due to Anisotropy in Heisenberg Mixed-Spin Chains,"We discuss the critical behavior of the spin-(1,1/2) Heisenberg ferrimagnetic
chain in a magnetic field, whose magnetization curve exhibits a plateau at a
third of the full magnetization. A bond alternation stabilizes the massive
state, whereas an exchange anisotropy causes the breakdown of the plateau and
the onset of a gapless spin-fluid state, where the transition, lying in the XY
but ferromagnetic region, is of Kosterlitz-Thouless type. In order to elucidate
significant quantum effects, we investigate the model of classical version as
well.",9905311v1
2000-03-15,"Magnetic Double Structure for S=1, 1/2 Mixed-Spin Systems","We investigate the zero-temperature and the finite-temperature properties of
the two-dimensional antiferromagnetic quantum spin system composed of the s=1/2
and s=1 spins. The spin excitation spectrum as well as the thermodynamic
quantities are computed by means of the Schwinger-boson mean-field theory. We
discuss how the magnetic double structure with the gapful and the gapless
excitations is generated, and apply the results systematically to the Haldane
gap system in a staggered magnetic field and also to the weakly coupled
ferrimagnetic mixed-spin chains. It is confirmed that the results obtained are
consistent with the experiments for the quasi-one-dimensional Haldane compounds
$R_2 \rm BaNiO_5$.",0003252v1
2000-04-18,Modified spin-wave description of the nuclear spin relaxation in ferrimagnetic Heisenberg chains,"We make a modified spin-wave description of the nuclear spin relaxation in
Heisenberg alternating-spin chains with antiferromagnetic exchange coupling. In
contrast with the conventional one-dimensional antiferromagnetic spin-wave
theory, which is plagued with the divergence of the sublattice magnetization
even in the ground state, the present spin-wave description is highly
successful over a wide temperature range. The temperature dependence of the
relaxation rate $T_1^{-1}$ significantly varies with the crystalline structure,
exhibiting both ferromagnetic and antiferromagnetic aspects. $T_1^{-1}$ further
shows a unique dependence on the applied field, which turns out an indirect
observation of the quadratic dispersion relations.",0004297v1
2001-05-25,Half-metallic antiferromagnets in thiospinels,"We have theoretically designed the half-metallic (HM) antiferromagnets (AFMs)
in thiospinel systems, $\rm Mn(CrV)S_{4}$ and $\rm
Fe_{0.5}Cu_{0.5}(V_{0.5}Ti_{1.5})S_{4}$, based on the electronic structure
studies in the local-spin-density approximation (LSDA). We have also explored
electronic and magnetic properties of parent spinel compounds of the above
systems; $\rm CuV_{2}S_{4}$ and $\rm CuTi_{2}S_{4}$ are found to be HM
ferromagnets in their cubic spinel structures, while $\rm MnCr_{2}S_{4}$ is a
ferrimagnetic insulator. We have discussed the feasibility of material
synthesis of HM-AFM thiospinel systems.",0105492v1
2001-06-05,Modulated replica symmetry breaking schemes for antiferromagnetic spin glasses,"We define modulated replica symmetry breaking (RSB)-schemes which combine
tree- and wave-like structures. A modulated scheme and unmodulated RSB are
applied at 1-step level to a semiconductor model with antiferromagnetic
Korenblit-Shender interaction. By comparison of the free energies we find
evidence that a T=0 phase transition in the ferrimagnetic phase leads to a
transition between the different RSB-schemes. An embedding factor of Parisi
block matrices with sublattice-asymmetrical size is employed as a new
variational parameter in the modulated scheme.",0106066v3
2001-06-25,Magnetization Process of the S=1 and 1/2 Uniform and Distorted Kagome Heisenberg Antiferromagnets,"The magnetization process of the S=1 and 1/2 kagome Heisenberg
antiferromagnet is studied by means of the numerical exact diagonalization
method. It is found that the magnetization curve at zero temperature has a
plateau at 1/3 of the full magnetization. In the presence of $\sqrt{3} \times
\sqrt{3}$ lattice distortion, this plateau is enhanced and eventually the
ferrimagnetic state is realized. There also appear the minor plateaux above the
main plateau. The physical origin of these phenomena is discussed.",0106498v2
2001-11-21,Extraordinary magnetization behavior of single crystalline TbFe_4.4Al_7.6,"We report the observation of a field-induced transformation from the
easy-plane antiferromagnetic structure to the easy-axis ferrimagnetic structure
in a single crystal of TbFe_4.4Al_7.6 (tetragonal ThMn_12 structure) at 5 K.
Such a field-induced, irreversible transition has been identified for the first
time. This transition is accompanied by a giant orthorhombic distortion:
epsilon_aa = - epsilon_bb ~ 3.5x10^-4 that is associated with a magnetic
hardness (mu_0H_C ~ 3 T) that is unprecedented in this category of materials.",0111408v1
2002-06-10,Realization of La2MnVO6: Search for half-metallic antiferromagnetism?,"Single-phase polycrystalline La2MnVO6 samples were synthesized by arc melting
and characterized by X-ray diffraction, magnetization and resistivity
measurements. We find that the compound has cubic (space group), partly ordered
double perovskite structure. The sample exhibits ferrimagnetic behavior and
variable-range hopping conductivity. We conclude based on the magnetic
properties that both Mn and V ions are trivalent; moreover, the Mn3+ ions are
in a high-spin state, which is the reason that the compound is not a
half-metallic antiferromagnet.",0206146v1
2002-07-22,Thermodynamic properties of the exactly solvable transverse Ising model on decorated planar lattices,"The generalized mapping transformation technique is used to obtain the exact
solution for the transverse Ising model on decorated planar lattices. Within
this scheme, the basic thermodynamic quantities are calculated for different
planar lattices with arbitrary spins of decorating atoms. The particular
attention has been paid to the investigation of the transverse-field effects on
magnetic properties of the system under investigation. The most interesting
numerical results for the phase diagrams, compensation temperatures and several
thermodynamic quantities are discussed in detail for the ferrimagnetic version
of the model.",0207522v1
2002-12-24,XY ring-exchange model on the triangular lattice,"We study ring-exchange models for bosons or XY-spins on the triangular
lattice. A four-spin exchange leads to a manifold of ground states with gapless
excitations and critical power-law correlations. With a nearest-neighbour
exchange, fluctuations select a four-fold ferrimagnetically ordered ground
state with a small spin/superfluid stiffness which breaks the global U(1) and
translational symmetry. We explore consequences for phase transitions at finite
temperature and in an in-plane magnetic field.",0212589v2
2003-05-06,Ferrimagnetism and compensation points in a decorated 3D Ising models,"We give a precise numerical solution for decorated Ising models on the simple
cubic lattice which show ferromagnetism, compensation points, and reentrant
behaviour. The models, consisting of $S={1\over 2}$ spins on a simple cubic
lattice, and decorating S=1 or $S=3/2$ spins on the bonds, can be mapped
exactly onto the normal spin-1/2 Ising model, whose properties are well known.",0305095v1
2003-12-03,Effective collective barrier for magnetic relaxation in frozen ferrofluids,"Magnetic relaxation and frequency response were measured in frozen
ferrimagnetic colloids of different concentrations. A crossover from reversible
to irreversible behavior is observed for concentrated colloids. In irreversible
state, magnetic relaxation is time-logarithmic over seven orders of magnitude
of experimental time windows. A master curve construction within mean field
phenomenological model is applied to extract effective collective barrier as a
function of the irreversible magnetization. The barrier logarithmically
diverges, providing evidence for self-organized critical behavior during
magnetic relaxation in frozen ferrofluids.",0312087v1
2004-04-20,Cooperative ordering of gapped and gapless spin networks in Cu$_2$Fe$_2$Ge$_4$O$_{13}$,"The unusual magnetic properties of a novel low-dimensional quantum
ferrimagnet Cu$_2$Fe$_2$Ge$_4$O$_{13}$ are studied using bulk methods, neutron
diffraction and inelastic neutron scattering. It is shown that this material
can be described in terms of two low-dimensional quantum spin subsystems, one
gapped and the other gapless, characterized by two distinct energy scales.
Long-range magnetic ordering observed at low temperatures is a cooperative
phenomenon caused by weak coupling of these two spin networks.",0404468v1
2004-04-29,Phase diagram of a frustrated mixed-spin ladder with diagonal exchange bonds,"Using exact numerical diagonalization and the conformal field theory
approach, we study the effect of magnetic frustrations due to diagonal exchange
bonds in a system of two coupled mixed-spin $(1,{1/2})$ Heisenberg chains. It
is established that relatively moderate frustrations are able to destroy the
ferrimagnetic state and to stabilize the critical spin-liquid phase typical for
half-integer-spin antiferromagnetic Heisenberg chains. Both phases are
separated by a narrow but finite region occupied by a critical
partially-polarized ferromagnetic phase.",0404703v1
2005-04-01,Exact ground states of quantum spin-2 models on the hexagonal lattice,"We construct exact non-trivial ground states of spin-2 quantum
antiferromagnets on the hexagonal lattice. Using the optimum ground state
approach we determine the ground state in different subspaces of a general
spin-2 Hamiltonian consistent with some realistic symmetries. These states,
which are not of simple product form, depend on two free parameters and can be
shown to be only weakly degenerate. We find ground states with different types
of magnetic order, i.e. a weak antiferromagnet with finite sublattice
magnetization and a weak ferromagnet with ferrimagnetic order. For the latter
it is argued that a quantum phase transition occurs within the solvable
subspace.",0504023v1
2005-04-26,The electronic structure of the antiferromagnetic semiconductor MnSb_2S_4,"The electronic band structures of orthorhombic (oP28) and monoclinic (mC28)
MnSb_2S_4 were investigated with ab initio calculations in the local spin
density approximation (LSDA) to the density functional theory (DFT). An
analysis of the electronic properties and of the chemical bonding is provided
using the augmented spherical wave (ASW) method considering nonmagnetic,
ferromagnetic, ferrimagnetic and antiferromagnetic model orderings. In
agreement with experimental results both modifications of MnSb_2S_4 are
predicted to be antiferromagnetic. While the experimental band gap is missed
for the monoclinic polymorph, the calculated band gap for orthorhombic
MnSb_2S_4 is close to the experimental one.",0504669v1
2005-09-28,Magnetic properties of antiferromagnetically coupled CoFeB/Ru/CoFeB,"This work reports on the thermal stability of two amorphous CoFeB layers
coupled antiferromagnetically via a thin Ru interlayer. The saturation field of
the artificial ferrimagnet which is determined by the coupling, J, is almost
independent on the annealing temperature up to more than 300 degree C. An
annealing at more than 325 degree C significantly increases the coercivity, Hc,
indicating the onset of crystallization.",0509753v1
2005-12-24,Low-temperature thermodynamics of one-dimensional alternating-spin Heisenberg ferromagnets,"Motivated by a novel bimetallic chain compound in which alternating magnetic
centers are ferromagnetically coupled, we investigate thermodynamic properties
of one-dimensional spin-$(S,s)$ Heisenberg ferromagnets both numerically and
analytically. On the one hand, quantum Monte Carlo calculations illuminate the
overall thermal behavior. The specific heat may exhibit a double-peaked
structure at intermediate temperatures for $S\agt 3s$ in general. On the other
hand, a modified spin-wave theory precisely describes the low-temperature
properties. Expanding the specific heat and the magnetic susceptibility, we
reveal an analogy and a contrast between mixed-spin ferromagnets and
ferrimagnets.",0512630v1
2006-02-03,X-ray magnetic circular dichroism study of Re 5d magnetism in Sr2CrReO6,"We have measured Re 5d spin and orbital magnetic moments in the ferrimagnetic
double perovskite Sr2CrReO6 by X-ray magnetic circular dichroism at the L_{2,3}
edges. In fair agreement with recent band-structure calculations [Vaitheeswaran
et. al., Ref 1], at the Re site a large 5d spin magnetic moment of -0.68 mu_B
and a considerable orbital moment of +0.25 mu_B have been detected. We found
that the Curie temperature of the double perovskites A2BB'O6 scales with the
spin magnetic moment of the 'non-magnetic' B' ion.",0602071v1
2006-02-24,Magnetocaloric effect in hexacyanochromate Prussian blue analogs,"We report on the magnetocaloric properties of two molecule-based
hexacyanochromate Prussian blue analogs, nominally CsNi[Cr(CN)_6](H_2O) and
Cr_3[Cr(CN)_6]_2x12(H_2O). The former orders ferromagnetically below Tc=90 K,
whereas the latter is a ferrimagnet below Tc=230 K. For both, we find
significantly large magnetic entropy changes DSm associated to the magnetic
phase transitions. Notably, our studies represent the first attempt to look at
molecule-based materials in terms of the magnetocaloric effect for temperatures
well above the liquid helium range.",0602589v1
2006-04-20,Magnetic phase diagram of a frustrated ferrimagnetic ladder: Relation to the one-dimensional boson Hubbard model,"We study the magnetic phase diagram of two coupled mixed-spin $(1,{1/2})$
Heisenberg chains as a function of the frustration parameter related to
diagonal exchange couplings. The analysis is performed by using spin-wave
series and exact numerical diagonalization techniques. The obtained phase
diagram--containing the Luttinger liquid phase, the plateau phase with a
magnetization per rung $M=1/2$, and the fully polarized phase--is closely
related to the generic $(J/U,\mu/U)$ phase diagram of the one-dimensional boson
Hubbard model.",0604495v1
2006-07-13,The SU(3) bosons and the spin nematic state on the spin-1 bilinear-biquadratic triangular lattice,"A bond-operator mean-field theory in the SU(3) bosons representation is
developed to describe the antiferro-nematic phase of the spin-1
bilinear-biquadratic model. The calculated static structure factors reveal
delicately that the antiferro-nematic state may exhibit both the ferro- and
antiferro-quadruple long-range orders, which is reminiscent of the ferrimagnets
or the canted antiferromagnets. This result may influence the spin wave theory
concerned with this phase. Possible relevance of this unconventional state to
the quasi-two-dimensional triangular material NiGa2S4 is addressed.",0607330v1
2007-03-29,Thermo-reversible permanent magnets in the quasi-binary GdCo5-xCux system,"Ferrimagnetic GdCo5-xCux alloys exhibiting the effect of Gd- and
3d-sublattice magnetization compensation at defined temperatures were studied
with respect to their use as thermo-reversible permanent magnets (PM). Coercive
fields &#61549;0Hc in the range 0.3 to 1.6 T were measured for annealed single
crystals with x = 1 - 2.2 having compensation points in the vicinity of room
temperature. Two applications of such a thermo-reversible PM, namely a
thermally controlled actuator and a contactless temperature sensor, are
demonstrated.",0703775v1
1994-11-29,Which Higgs-Yukawa systems can possess non-trivial fixed points,"We argue that non-trivial fixed points bordering on the paramagnetic and
ferromagnetic phases are most likely to exist in the Higgs-Yukawa systems that
have a connected domain with the paramagnetic phase and no ferrimagnetic phase.
We find three examples of such systems; among them is the U(1) system with
naive fermions.",9411069v1
1992-06-01,q--Magnetism at roots of unity,"We study the thermodynamic properties of a family of integrable 1D spin chain
hamiltonians associated with quantum groups at roots of unity. These
hamiltonians depend for each primitive root of unit on a parameter $s$ which
plays the role of a continuous spin. The model exhibits ferrimagnetism even
though the interaction involved is between nearest neighbors. The latter
phenomenon is interpreted as a genuine quantum group effect with no
``classical"" analog. The discussion of conformal properties is given.",9206001v1
2004-08-11,A Ferromagnetic Lieb-Mattis Theorem,"We prove ferromagnetic ordering of energy levels for XXX Heisenberg chains of
any spin and XXZ spin chains with all spins equal to 1/2. Ferromagnetic
ordering means that the minimum energies in the invariant subspaces of fixed
total spin are monotone decreasing as a function of the total spin. This result
provides a ferromagnetic analogue of the well-known theorem by Lieb and Mattis
about ordering of energy levels in antiferromagnetic and ferrimagnetic systems
on bipartite graphs.",0408020v3
2007-04-19,Classical Heisenberg Hamiltonian Solution of Oriented Spinel Ferrimagnetic Thin Films,"The classical Heisenberg Hamiltonian was solved for oriented spinel thin and
thick cubic ferrites. The dipole matrix of complicated cubic cell could be
simplified into the form of dipole Matrix of simple cubic cells. This study was
confined only to the highly oriented thin films of ferrite. The variation of
total energy of Nickel ferrite thin films with angle and number of layers was
investigated. Also the change of energy with stress induced anisotropy for
Nickel ferrite films with N=5 and 1000 has been studied. Films with the
magnetic moments ratio 1.86 can be easily oriented in 90 direction when N is
greater than 400.",0704.2456v1
2007-07-06,Field induced magnetic transition and metastability in Co substituted $Mn_{2}Sb$,"A detailed investigation of first order ferrimagnetic (FRI) to
antiferromagnetic (AFM) transition in Co (15%) doped $Mn_2Sb$ is carried out.
These measurements demonstrate anomalous thermomagnetic irreversibility and
glass-like frozen FRI phase at low temperatures. The irreversibility arising
between the supercooling and superheating spinodals is distinguised in an
ingenious way from the irreversibility arising due to kinetic arrest. Field
annealing measurements shows reentrant FRI-AFM-FRI transition with increasing
temperature. These measurements also show that kinetic arrest band and
supercooling band are anitcorrelated i.e regions which are kinetically arrested
at higher temperature have lower supercooling temperature and vice versa.",0707.0950v1
2007-11-26,Ab initio prediction on ferrotoroidic olivine Li4MnFeCoNiP4O16,"First-principles calculation predict that olivine Li4MnFeCoNiP4O16 has
ferrotoroidic characteristic and ferrimagnetic configuration with magnetic
moment of 1.56 \muB per formula unit. The ferrotoroidicity of this material
makes it a potential candidate for magnetoelectric materials . Based on the
orbital-resolved density of states for the transtion-metal ions in
Li4MnFeCoNiP4O16, the spin configuration for Mn2+,Fe3+,Co2+, and Ni2+ is
t2g3eg2, t2g3eg2,t2g1t2g3eg1eg2, and t2g2t2g3eg1eg2, respectively. Density
functional theory plus U (DFT+U) shows a indirect band gap of 1.25 eV in this
predicted material, which is not simply related to the electronic conductivity
in terms of being used as cathode material in rechargeable Li-ion batteries.",0711.3904v1
2008-03-12,Spin-lattice model of Magneto-electric Transitions in RbCoBr$_3$,"Extensive Monte Carlo simulations are performed to analyze a recent neutron
diffraction experiment on a distorted triangular lattice compound RbCoBr$_3$.
We consider a spin-lattice model, where both spin and lattice are Ising
variables. This model explains well successive magnetic and dielectric
transitions observed in the experiment. The exchange interaction parameters and
the spin-lattice coupling are estimated. It is found that the spin-lattice
coupling is important to explain the slow growth of a ferrimagnetic order. The
present simulations were made possible by developing a new Monte Carlo
algorithm, which accelerates slow Monte Carlo dynamics of quasi-one-dimensional
frustrated systems.",0803.1710v2
2009-08-21,Nonzero macroscopic magnetization in half-metallic antiferromagnets at finite temperatures,"Combining density-functional theory calculations with many-body
Green's-function technique, we reveal that the macroscopic magnetization in
half-metallic antiferromagnets does not vanish at finite temperature as for the
T=0 limit. This anomalous behavior stems from the inequivalent magnetic
sublattices which lead to different intrasublattice exchange interactions. As a
consequence, the spin fluctuations suppress the magnetic order of the
sublattices in a different way leading to a ferrimagnetic state at finite
temperatures. Computational results are presented for the half-metallic
antiferromagnetic CrMnZ (Z=P,As,Sb) semi-Heusler compounds.",0908.3044v1
2009-10-30,Interplay of Quantum Criticality and Geometric Frustration in Columbite,"Motivated by CoNb2O6 (belonging to the columbite family of minerals), we
theoretically study the physics of quantum ferromagnetic Ising chains coupled
anti-ferromagnetically on a triangular lattice in the plane perpendicular to
the chain direction. We combine exact solutions of the chain physics with
perturbative approximations for the transverse couplings. When the triangular
lattice has an isosceles distortion (which occurs in the real material), the
T=0 phase diagram is rich with five different states of matter: ferrimagnetic,
N\'eel, anti-ferromagnetic, paramagnetic and incommensurate phases, separated
by quantum phase transitions. Implications of our results to experiments on
CoNb2O6 are discussed.",0911.0038v1
2009-11-20,Superparamagnetic nanoparticle ensembles,"Magnetic single-domain nanoparticles constitute an important model system in
magnetism. In particular ensembles of superparamagnetic nanoparticles can
exhibit a rich variety of different behaviors depending on the inter-particle
interactions. Starting from isolated single-domain ferro- or ferrimagnetic
nanoparticles the magnetization behavior of both non-interacting and
interacting particle-ensembles is reviewed. A particular focus is drawn onto
the relaxation time of the system. In case of interacting nanoparticles the
usual Neel-Brown relaxation law becomes modified. With increasing interactions
modified superparamagnetism, spin glass behavior and superferromagnetism is
encountered.",0911.4031v2
2010-04-26,Ferromagnetism of cold fermions loaded into a decorated square lattice,"We investigate two-component ultracold fermions loaded into a decorated
square lattice, which are described by the Hubbard model with repulsive
interactions and nearest neighbor hoppings. By combining the real-space
dynamical mean-field theory with the numerical renormalization group method, we
discuss how a ferromagnetically ordered ground state in the weak coupling
regime, which originates from the existence of a dispersionless band, is
adiabatically connected to a Heisenberg ferrimagnetic state in the strong
coupling limit. The effects of level splitting and hopping imbalance are also
addressed.",1004.4650v1
2010-06-23,Multiferroic BiFeO3-BiMnO3 Nanocheckerboard From First Principles,"We present a first principles study of an unusual heterostructure, an
atomic-scale checkerboard of BiFeO3-BiMnO3, and compare its properties to the
two bulk constituent materials, BiFeO3 and BiMnO3. The ""nanocheckerboard"" is
found to have a multiferroic ground state with the desired properties of each
constituent: polar and ferrimagnetic due to BiFeO3 and BiMnO3, respectively.
The effect of B-site cation ordering on magnetic ordering in the BiFeO3-BiMnO3
system is studied. The checkerboard geometry is seen to give rise to a a novel
magnetostructural effect that is neither present in the bulk constituent
materials, nor in the layered BiFeO3-BiMnO3 superlattice.",1006.4648v1
2010-08-06,Ferromagnetic phases in spin-Fermion systems,"Spin-Fermion systems which obtain their magnetic properties from a system of
localized magnetic moments being coupled to conducting electrons are
considered. The dynamical degrees of freedom are spin-$s$ operators of
localized spins and spin-1/2 Fermi operators of itinerant electrons.
Renormalized spin-wave theory, which accounts for the magnon-magnon
interaction, and its extension are developed to describe the two ferrimagnetic
phases in the system: low temperature phase $0<T<T^{*}$, where all electrons
contribute the ordered ferromagnetic moment, and high temperature phase
$T^{*}<T<T_C$, where only localized spins form magnetic moment. The
magnetization as a function of temperature is calculated. The theoretical
predictions are utilize to interpret the experimentally measured
magnetization-temperature curves of $UGe_2$..",1008.1148v1
2011-02-04,Current-induced dynamics of composite free layer with antiferromagnetic interlayer exchange coupling,"Current-induced dynamics in spin valves including composite free layer with
antiferromagnetic interlayer exchange coupling is studied theoretically within
the diffusive transport regime. We show that current-induced dynamics of a
synthetic antiferromagnet is significantly different from dynamics of a
synthetic ferrimagnet. From macrospin simulations we obtain conditions for
switching the composite free layer, as well as for appearance of various
self-sustained dynamical modes. Numerical simulations are compared with simple
analytical models of critical current based on linearized
Landau-Lifshitz-Gilbert equation.",1102.1028v2
2011-03-19,Spin transfer torque on magnetic insulators,"Recent experimental and theoretical studies focus on spin-mediated heat
currents at interfaces between normal metals and magnetic insulators. We
resolve conflicting estimates for the order of magnitude of the spin transfer
torque by first-principles calculations. The spin mixing conductance
G^\uparrow\downarrow of the interface between silver and the insulating
ferrimagnet Yttrium Iron Garnet (YIG) is dominated by its real part and of the
order of 10^14 \Omega^-1m^-2, i.e. close to the value for intermetallic
interface, which can be explained by a local spin model.",1103.3764v2
2011-05-19,Magnetic order near 270 K in mineral and synthetic Mn$_2$FeSbO$_6$ ilmenite,"The structural and magnetic properties of Mn$_2$FeSbO$_6$ single-crystalline
mineral and ceramic samples synthesized under thermobaric treatment have been
investigated, and compared to theoretical predictions based on first-principles
electronic structure calculations. This ilmenite system displays a sharp
magnetic transition just below the room temperature related to a ferrimagnetic
ordering of the Mn$^{2+}$ and Fe$^{3+}$ cations, which makes Mn$_2$FeSbO$_6$ a
promising candidate for designing functional magnetic materials.",1105.3973v1
2011-05-27,Phase diagram of the Cairo pentagonal XXZ spin-1/2 magnet under a magnetic field,"The phase diagram of the XXZ spin-1/2 magnet, equivalent to hard-core bosons,
under a staggered magnetic field and on the Cairo pentagonal lattice is
computed at zero and finite temperature by using a cluster mean field theory
and a stochastic series expansion quantum Monte Carlo.The complex connectivity
and the frustration lead to unconventional phases such as a 1/3-ferrimagnetic
plateau stabilized by quantum fluctuations as well as a 5/12-topological phase
induced by a local ice-rule constraint. We also report the presence of a
ferrimagnetic superfluid and its thermal melting. Finally, we discuss the
ferro- and antiferro- magnetic (hopping sign) cases.",1105.5671v2
2011-07-11,Exchange bias effect in alloys and compounds,"The phenomenology of exchange bias effects observed in structurally
single-phase alloys and compounds but composed of a variety of coexisting
magnetic phases such as ferromagnetic, antiferromagnetic, ferrimagnetic,
spin-glass, cluster-glass and disordered magnetic states are reviewed. The
investigations on exchange bias effects are discussed in diverse types of
alloys and compounds where qualitative and quantitative aspects of magnetism
are focused based on macroscopic experimental tools such as magnetization and
magnetoresistance measurements. Here, we focus on improvement of fundamental
issues of the exchange bias effects rather than on their technological
importance.",1107.1978v1
2011-12-13,Phase Diagram of the mixed spin-2 and spin-5/2 Ising system with two different single-ion anisotropies,"In this paper we present a study of the effects of two different single-ion
anisotropies in the phase diagram and in the compensation temperature of the
mixed spin-2 and spin-5/2 Ising ferrimagnetic system. We employed the
mean-field theory based on the Bogoliubov inequality for the Gibbs free energy.
Also we found the Landau expansion of the free energy in the order parameter to
describe the phase diagrams. In the plane critical temperature versus
single-ion anisotropie the phase diagram displays tricritical behavior. The
critical and compensation temperatures increase when the single-ion
anisotropies increase.",1112.2989v1
2012-06-20,Magnetoelectric nature of skyrmions in a chiral magnetic insulator Cu2OSeO3,"Dielectric properties were investigated under various magnitudes and
directions of magnetic field (H) for a chiral magnetic insulator Cu2OSeO3. We
found that the skyrmion crystal induces electric polarization (P) along either
in-plane or out-of-plane direction of the spin vortices depending on the
applied H-direction. The observed H-dependence of P in ferrimagnetic,
helimagnetic, and skyrmion crystal state can be consistently described by the
d-p hybridization model, highlighting an important role of relativistic
spin-orbit interaction in the magnetoelectric coupling in Cu2OSeO3. Our
analysis suggests that each skyrmion particle can locally carry electric dipole
or quadrupole, which implies that the dynamics of skyrmions are controllable by
the external electric field.",1206.4404v1
2012-12-21,Low-temperature metastable states in a stacked triangular Ising antiferromagnet,"We study low-temperature magnetization processes in a stacked triangular
Ising antiferromagnet by Monte Carlo simulations. In increasing and decreasing
magnetic fields we observe multiple steps and hysteresis corresponding to
formation of different metastable states. Besides the equidistant threefold
splitting of the 1/3 ferrimagnetic plateau, we additionally confirm a fourth
plateau in the field-increasing branch and a sizable remanence when the field
is decreased to zero. The newly observed plateau only appears at sufficiently
low temperature and sufficiently large exchange interaction in the stacking
direction. These observations reasonably reproduce low-temperatures
measurements on the spin-chain compound $\rm{Ca}_3\rm{Co}_2\rm{O}_6$.",1212.5455v1
2013-03-05,Phase diagram of the isotropic spin-3/2 model on the z=3 Bethe lattice,"We study an SU(2) symmetric spin-3/2 model on the z=3 Bethe lattice using the
infinite Time Evolving Block Decimation (iTEBD) method. This model is shown to
exhibit a rich phase diagram. We compute the expectation values of several
order parameters which allow us to identify a ferromagnetic, a ferrimagnetic, a
anti-ferromagnetic as well as a dimerized phase. We calculate the entanglement
spectra from which we conclude the existence of a symmetry protected
topological phase that is characterized by S=1/2 edge spins. Details of the
iTEBD algorithm used for the simulations are included.",1303.1110v1
2013-07-11,Tuning the giant inverse magnetocaloric effect in Mn2-xCrxSb compounds,"Structural, magnetic and magnetocaloric properties of Mn2-xCrxSb compounds
have been studied. In these compounds a first order magnetic phase transition
from the ferrimagnetic to the antiferromagnetic state occurs with decreasing
temperature, giving rise to giant inverse magnetocaloric effects that can be
tuned over a wide temperature interval through changes in substitution
concentration. Entropy changes as high as 7.5 J/kgK have been observed, and a
composition independent entropy change is obtained for several different
concentrations/working temperatures, making these compounds suitable candidates
for a composite working material.",1307.3194v1
2013-10-08,Charge Order with a Noncoplanar Triple-Q Magnetic Order on a Cubic Lattice,"Ground state of the periodic Anderson model on a cubic lattice is
investigated by mean-field calculations, with focusing on the possibility of
charge ordering. We show that three different charge-ordered phases appear at
3/2 filling, which are accompanied by ferromagnetic, noncoplanar triple-Q, and
ferrimagnetic order, respectively. The triple-Q magnetic order is likely
stabilized by emergent geometrical frustration in the charge-ordered phase with
the ordering wave vector (pi,pi,pi). We show that the nearest-neighbor hopping
between localized electrons stabilizes the triple-Q phase relative to the other
two phases. We also discuss the electronic structure in the triple-Q
charge-ordered phase.",1310.1982v1
2013-11-03,Dependencia de la Temperatura de Compensación en Modelos de Multicapas Ferrimagnéticas de tipo $3(S_{1-x} σ_x)/σ$,"We investigate numerically the behavior of the compensation temperature,
$T_{comp}$, in ferrimagnetic multilayer in the type $3(S_{1-x}
\sigma_x)/\sigma$ with respect to the increase of the spin concentration
$\sigma_x$, which are randomly distributive in a mix of spins $S = 0, \pm 1$
and $\sigma = \pm 1/2$, with ferromagnetic interaction between spins of the
same type, and antiferromagnetic interaction for spins of different type. We
have found that $T_{comp}$ decrease slowly with the increase of $x$, until
$\sigma_x$ represent a little more than 40\% of the spin mixture. For higher
concentration values $T_{comp}$ drops abruptly and disappears, as predicted by
experimental result.",1311.0465v1
2014-04-29,Spin Hall Magnetoimpedance,"The recently discovered spin Hall magnetoresistance effect electrically
probes pure spin current flow across a ferrimagnetic insulator/normal metal
bilayer interface. While usually the DC electrical resistance of the bilayer is
measured as a function of the magnetization orientation in the magnetic
insulator, we here present magnetoimpedance measurements using bias currents
with frequencies up to several GHz. We find that the spin Hall
magnetoresistance effect persists up to frequencies of at least 4 GHz, enabling
a fast readout of the magnetization direction in magnetic insulator/normal
metal bilayers. Our data furthermore show that all interaction time constants
relevant for the spin Hall magnetoresistance effect are shorter than 40 ps.",1404.7432v1
2014-07-04,Hexagonal type Ising nanowire with spin-1 core and spin-2 shell structure,"}Thermodynamic properties and phase diagrams of a mixed spin-(1, 2) Ising
ferrimagnetic system with single ion anisotropy on hexagonal nanowire are
studied by using effective-field theory with correlations. The susceptibility,
internal energy and specific heat of the system are numerically examined and
some interesting phenomena in these quantities are found. The effect of the
Hamiltonian parameters on phase diagrams are examined in detail. Besides
second-order phase transition, lines of first-order transition and tricritical
points are found. In particular, we found that for some negative values of
single-ion anisotropies, there exist first-order phase transitions.",1407.1147v1
2014-09-23,Guidelines for understanding cubic manganese-rich Heusler compounds,"Manganese-rich Heusler compounds are attracting much interest in the context
of spin transfer torque and rare-earth free hard magnets. Here we give a
comprehensive overview of the magnetic properties of non-centrosymmetric cubic
Mn$_2$-based Heusler materials, which are characterized by an antiparallel
coupling of magnetic moments on Mn atoms. Such a ferrimagnetic order leads to
the emergence of new properties that are absent in ferromagnetic
centrosymmetric Heusler structures. In terms of the band structure
calculations, we explain the formation of this magnetic order and the Curie
temperatures. This overview is intended to establish guidelines for a basic
understanding of magnetism in Mn2 -based Heusler compounds.",1409.6532v1
2015-06-09,Identification of spin wave modes strongly coupled to a co-axial cavity,"We demonstrate, at room temperature, the strong coupling of the fundamental
and non-uniform magnetostatic modes of an yttrium iron garnet (YIG)
ferrimagnetic sphere to the electromagnetic modes of a co-axial cavity. The
well-defined field profile within the cavity yields a specific coupling
strength for each magnetostatic mode. We experimentally measure the coupling
strength for the different magnetostatic modes and, by calculating the expected
coupling strengths, are able to identify the modes themselves.",1506.02902v1
2015-06-18,An alloy calculation of pure antiferromagnetic NiO,"We use the many techniques of alloy theory to study antiferromagnetic NiO,
considered as an alloy of spin-up and spin-down Ni atoms. The questions are:
the true antiferromagnetic ground state and the possibility of obtaining
ferrimagnetic configurations. Further we use the GGA/LDA- 1/2 technique to
investigate the electronic excitation spectrum. We found two valence bands and
band gaps, of 4.0eV consistent with bremsstrahlung-isochromat-spectroscopy
(BIS) result, and 1.2eV consistent with the known 10Dq value for the Ni++ ion.
The features of a Mott insulator are presented without recurring to an
electron-pair correlation.",1506.05778v2
2015-11-23,Polarized neutron channeling as a tool for the investigations of weakly magnetic thin films,"We present and apply a new method to measure directly weak magnetization in
thin films. The polarization of a neutron beam channeling through a thin film
structure is measured after exiting the structure edge as a microbeam. We have
applied the method to a tri-layer thin film structure acting as a planar
waveguide for polarized neutrons. The middle guiding layer is a rare earth
based ferrimagnetic material TbCo5 with a low magnetization of about 20 mT. We
demonstrate that the channeling method is more sensitive than the specular
neutron reflection method.",1511.07286v2
2016-09-07,Thermally induced magnon accumulation in two-sublattice magnets,"We present a temperature dependent study of the thermal excitation of
magnonic spin currents in two-sublattice magnetic materials. Using atomistic
spin model simulations, we study the local magnetization profiles in the
vicinity of a temperature step in antiferromagnets, as well as in ferrimagnets.
It is shown that the strength of the excitation of the spin currents in these
systems scales with the derivative of the magnetization with respect to the
temperature.",1609.02161v1
2016-10-27,Ground state properties of the Holstein-Hubbard model,"We study the ground state properties of the Holstein-Hubbard model on some
bipartite lattices at half-filling; The ground state is proved to exhibit
ferrimagnetism whenever the electron-phonon interaction is not so strong. In
addition, the antiferromagnetic long range order is shown to exist in the
ground state. In contrast to this, we prove the absence of the long range
charge order.",1610.09039v3
2017-03-03,Spin-orbit effective fields in Pt/GdFeCo bilayers,"In the increasing interests on spin-orbit torque (SOT) with various magnetic
materials, we investigated SOT in rare earth-transition metal ferrimagnetic
alloys. The harmonic Hall measurements were performed in Pt/GdFeCo bilayers to
quantify the effective fields resulting from the SOT. It is found that the
damping-like torque rapidly increases near the magnetization compensation
temperature TM of the GdFeCo, which is attributed to the reduction of the net
magnetic moment.",1703.00995v1
2020-07-22,Nanomagnonic cavities for strong spin-magnon coupling,"We present a theoretical approach to use ferro- or ferrimagnetic
nanoparticles as microwave nanomagnonic cavities to concentrate microwave
magnetic fields into deeply subwavelength volumes $\sim 10^{-13}$ mm$^3$. We
show that the field in such nanocavities can efficiently couple to isolated
spin emitters (spin qubits) positioned close to the nanoparticle surface
reaching the single magnon-spin strong-coupling regime and mediate efficient
long-range quantum state transfer between isolated spin emitters. Nanomagnonic
cavities thus pave the way towards magnon-based quantum networks and
magnon-mediated quantum gates.",2007.11595v1
2010-05-18,Effect of interfacial Cr on magnetoelectricity of Fe2/CrO2/BaTiO3(001),"On the basis of first-principles calculations we study the effect of
interfacial Cr on the magnetoelectric properties of a composite multiferroic
Fe_L/BaTiO_3(001), with the Fe thickness L=1,2 monolayers. The use of the
CrO_2-terminated interface instead of TiO_2 may significantly enhance
magnetoelectricity in the system, showing an unexpected change in magnetization
induced by the electric polarization reversal. In the case of L=2, for
instance, the magnetic order of the Fe bilayer can be switched from nearly zero
ferrimagnetic to ferromagnetic upon polarization reversal.",1005.3122v1
2013-08-14,Ising models on the Regularized Apollonian Network,"We investigate the critical properties of Ising models on a Regularized
Apollonian Network (RAN), here defined as a kind of Apollonian Network (AN) in
which the connectivity asymmetry associated to its corners is removed.
Different choices for the coupling constants between nearest neighbors are
considered, and two different order parameters are used to detect the critical
behaviour. While ordinary ferromagnetic and anti-ferromagnetic models on RAN do
not undergo a phase transition, some anti-ferrimagnetic models show an
interesting infinite order transition. All results are obtained by an exact
analytical approach based on iterative partial tracing of the Boltzmann factor
as intermediate steps for the calculation of the partition function and the
order parameters.",1308.3259v1
2012-01-23,Micromagnetic Simulations for Spin Transfer Torque in Magnetic Multilayers,"We investigate the spin transfer torque (STT) in the magnetic multilayer
structures with micromagnetic simulations. We implement the STT contribution
for the magnetic multilayer structures in addition to the
Landau-Lifshitz-Gilbert (LLG) micromagnetic simulators. Not only the Sloncewski
STT term, the zero, first, and second order field- like terms are also
considered, and the effects of the Oersted field by the current are addressed.
We determine the switching current densities of the free layer with the
exchange biased synthetic ferrimagnetic reference layers for various cases.",1201.4707v1
2013-09-11,Nanomechanical AC Susceptometry of an Individual Mesoscopic Ferrimagnet,"A novel method for simultaneous detection of both DC and time-dependent
magnetic signatures in individual mesoscopic structures has emerged from early
studies in spin mechanics. Multifrequency nanomechanical detection of AC
susceptibility and its harmonics highlights reversible nonlinearities in the
magnetization response of a single yttrium iron garnet (YIG) element,
separating them from hysteretic jumps in the DC magnetization.",1309.2965v1
2013-09-25,Magnetic and transport properties of Mn2CoAl oriented thin films,"The structure, magnetic and transport properties of thin films of the Heusler
ferrimagnet Mn_{2}CoAl have been investigated for properties related to spin
gapless semiconductors. Oriented films were grown by molecular beam epitaxy on
GaAs substrates and the structure was found to transform from tetragonal to
cubic for increasing annealing temperature. The anomalous Hall resistivity is
found to be proportional to the square of the longitudinal resistivity and
magnetization expected for a topological Berry curvature origin. A delicate
balance of the spin-polarized carrier type when coupled with voltage
gate-tuning could significantly impact advanced electronic devices.",1309.6660v1
2014-05-27,Strongly coupled magnons and cavity microwave photons,"We realize a cavity magnon-microwave photon system in which magnetic dipole
interaction mediates strong coupling between collective motion of large number
of spins in a ferrimagnet and the microwave field in a three-dimensional
cavity. By scaling down the cavity size and increasing number of spins, an
ultrastrong coupling regime is achieved with a cooperativity reaching 12600.
Interesting dynamic features including classical Rabi oscillation, magnetically
induced transparency, and Purcell effect are demonstrated in this highly
versatile platform, highlighting its great potential for coherent information
processing.",1405.7062v1
2015-12-03,Quantum cluster algorithm for frustrated Ising models in a transverse field,"Working within the stochastic series expansion framework, we introduce and
characterize a new quantum cluster algorithm for quantum Monte Carlo
simulations of transverse field Ising models with frustrated Ising exchange
interactions. As a demonstration of the capabilities of this new algorithm, we
show that a relatively small, ferromagnetic next-nearest neighbour coupling
drives the transverse field Ising antiferromagnet on the triangular lattice
from an antiferromagnetic three-sublattice ordered state at low temperature to
a ferrimagnetic three-sublattice ordered state.",1512.00931v1
2017-10-27,Ferrimagnetism and compensation temperature in spin-$1/2$ Ising trilayers,"The mean-field and effective-field approximations are applied in the study of
magnetic and thermodynamic properties of a spin-$1/2$ Ising system containing
three layers, each of which is composed exclusively of one out of two possible
types of atoms, \textbf{A} or \textbf{B}. The \textbf{A-A} and \textbf{B-B}
bonds are ferromagnetic while the \textbf{A-B} bonds are antiferromagnetic. The
occurrence of a compensation phenomenon is verified and the compensation and
critical temperatures are obtained as functions of the Hamiltonian parameters.
We present phase diagrams dividing the parameter space in regions where the
compensation phenomenon is present or absent and a detailed discussion about
the influence of each parameter on the overall behavior of the system is made.",1710.10298v1
2018-01-24,Spin-current coherence peak in superconductor/magnet junctions,"Coherence peak effects in a superconductor induced by a thermal spin current
are reported. We measured inverse spin Hall effects induced by spin injection
from a ferrimagnetic insulator Y$_3$Fe$_5$O$_{12}$ into a superconductor NbN
using longitudinal spin Seebeck effects. In the vicinity of the superconducting
transition temperature of the NbN, a large enhancement of the spin Seebeck
voltage is observed, whose sign is opposite to that for the vortex Nernst
effect, but is consistent with a calculation for a coherence peak effect in the
superconductor NbN.",1801.07943v1
2018-09-24,Phonon Magnetochiral Effect,"Magnetochiral effect (MChE) of phonons, a nonreciprocal acoustic property
arising due to the symmetry principles, is demonstrated in a chiral-lattice
ferrimagnet Cu$_2$OSeO$_3$. Our high-resolution ultrasound experiments reveal
that the sound velocity differs for parallel and antiparallel propagation with
respect to the external magnetic field.The sign of the nonreciprocity depends
on the chirality of the crystal in accordance with the selection rule of the
MChE. The nonreciprocity is enhanced below the magnetic ordering temperature
and at higher ultrasound frequencies, which is quantitatively explained by a
proposed magnon-phonon hybridization mechanism.",1809.08775v1
2018-09-28,Magneto-dielectric and Magneto-resistive in the Mixed Spinel MgFe2O4,"The mixed spinel, MgFe2O4 has been synthesized by ball-milling assisted
sintering method. X-ray diffraction study confirms formation of cubic MgFe2O4
and the lattice parameter values calculated are a = b = c = 8.369(3) {\AA}.
Vibrating sample magnetometer measurements at room temperature shows a soft
ferrimagnetic nature. Magneto-Dielectric and Magneto-Restive plots confirm
coupling at room temperature in the prepared MgFe2O4. The peak at 500 Oe in the
MD plot is due to the canting of Fe3+ ions distributed in octahedral and
tetrahedral sites.",1809.10968v1
2019-09-25,Magnetic Quantum Phase Transitions in a Clean Dirac Metal,"We consider clean Dirac metals where the linear band crossing is caused by a
strong spin-orbit interaction, and study the quantum phase transitions from the
paramagnetic phase to various magnetic phases, including homogeneous
ferromagnets, ferrimagnets, canted ferromagnets, and magnetic nematics. We show
that in all of these cases the coupling of fermionic soft modes to the order
parameter generically renders the quantum phase transition first order, with
certain gapless Dirac systems providing a possible exception. These results are
surprising since a strong spin-orbit scattering suppresses the mechanism that
causes the first order transition in ordinary metals. The important role of
chirality in generating a new mechanism for a first-order transition is
stressed.",1909.11642v1
2019-09-26,Metal-insulator transition in CaCu$_3$Fe$_4$O$_{12}$,"We study structurally-triggered metal-insulator transition in
CaCu$_3$Fe$_4$O$_{12}$ by means of local density approximation (LDA) +$U$ and
LDA+dynamical mean-field theory (DMFT). The ferrimagnetic insulating phase is
essentially the same within both approaches. While LDA+$U$ describes the
metal-insulator transition as a Peierls-like instability driven by Fermi
surface nesting in the magnetically ordered phase, LDA+DMFT allows also the
site-selective Mott transition without magnetic ordering as well as smooth
crossover between the two pictures. We point out similarities and differences
to rare-earth nickelates.",1909.12126v1
2019-10-09,Electric-field control of magnetism in iron oxide nanoparticle / BaTiO3 film composites,"We study composites of monodisperse ferrimagnetic nanoparticles (NPs)
embedded into ferroelectric barium titanate (BTO) films. The BTO films were
prepared by pulsed laser deposition. The composite consists of a stack of two
BTO films sandwiching one monolayer of iron oxide NPs. We observe a
magnetoelectric coupling due to strain and interface charge co-mediation
between the BTO and the NPs. This is demonstrated by measurements of the
magnetization as function of DC and AC electric fields.",1910.04127v1
2020-04-08,Role of anisotropy to the compensation in the Blume-Capel trilayered ferrimagnet,"The trilayered Blume-Capel ($S=1$) magnet with nearest neighbour intralayer
ferromagnetic and nearest neighbour interlayer antiferromagnetic interaction is
studied by Monte Carlo simulation. Depending on the relative interaction
strength and the value of anisotropy the critical temperature (where all the
sublattice magnetisations and consequently the total magnetisation vanishes)
and the compensation temperature (where the total magnetisation vanishes for a
special combination of nonzero sublattice magnetisations) are estimated. The
comprehensive phase diagrams with lines of critical temperatures and
compensation temperatures for different parameter values are drawn.",2004.03930v3
2018-03-17,Emergence of spin-orbit order in the spinel CuCr$_2$O$_4$,"We determined the magnetic structure of CuCr$_2$O$_4$ using neutron
diffraction and irreducible representation analysis. The measurements
identified a new phase between 155 K and 125 K as nearly collinear magnetic
ordering in the Cr pyrochlore lattice. Below 125 K, a Cu-Cr ferrimagnetic
component develops the noncollinear order. Along with the simultaneously
obtained O positions and the quantum effect of spin-orbit coupling, the
magnetic structure is understood to involve spin-orbit ordering, accompanied by
an appreciably deformed orbital of presumably spin-only Cu and Cr.",1803.06447v1
2018-06-18,Heisenberg-Ising delta-chain with bond alternation,"The spin-$\frac{1}{2}$ delta-chain (sawtooth chain) with antiferromagnetic
Heisenberg basal chain and Ising apical-basal interactions is studied. The
basal-apical interactions involve the bond alternation. The limiting cases of
the model include the symmetrical delta-chain and the antiferromagnetic chain
in the staggered magnetic field. We study ground state properties of the model
by the exact diagonalization and density matrix renormalization group methods.
The ground state phase diagram as a function of the bond alternation consists
of magnetic and various non-magnetic phases. All phases excluding the
ferrimagnetic phase are gapped and an origin of the gaps is cleared.",1806.06907v1
2019-11-15,Quantum Phase Transitions of the Distorted Diamond Spin Chain,"The frustrated quantum spin system on the distorted diamond chain lattice
suitable for the alumoklyuchevskite is investigated using the numerical
diagonalization of finite-size clusters and the level spectroscopy analysis. It
is found that this model exhibits three quantum phases; the ferrimagnetic
phase, the spin gap one, and the gapless Tomonaga-Luttinger liquid depending on
the exchange coupling parameters. The ground state phase diagram is presented.",1911.06539v1
2021-03-02,Thermal entanglement in $2\otimes3$ Heisenberg chains via distance between states,"Most of the work involving entanglement measurement focuses on systems that
can be modeled by two interacting qubits. This is due to the fact that there
are few studies presenting entanglement analytical calculations in systems with
spins $s > 1/2$. In this paper we present for the first time an analytical way
of calculating thermal entanglement in a dimension $2\otimes3$ Heisenberg chain
through the distance between states. We use the Hilbert-Schmidt norm to obtain
entanglement. The result obtained can be used to calculate entanglement in
chains with spin-$1/2$ coupling with spin-$1$, such as ferrimagnetic compounds
as well as compounds with dimer-trimer coupling.",2103.02019v1
2021-10-07,Mössbauer measurements of GaFeO$_3$ single crystal multiferroic,"M\""ossbauer measurements on single crystal absorbers at room and at low
temperatures were performed. The results are fully consistent with previously
published reports by other groups. Spectra of single crystals were
simultaneously analyzed including magnetic dipole and electric quadrupole
interactions. The analysis shows that there is a small component of magnetic
moments perpendicular to the magnetic easy axis. M\""ossbauer data seem not
agree with commonly accepted ferrimagnetic structure of GaFeO$_3$.",2110.03285v1
2023-07-02,Unveiling Stable One-dimensional Magnetic Solitons in Magnetic Bilayers,"We propose a novel model which efficiently describes the magnetization
dynamics in a magnetic bilayer system. By applying a particular gauge
transformation to the Landau-Lifshitz-Gilbert (LLG) equation, we successfully
convert the model into an exactly integrable framework. Thus the obtained
analytical solutions allows us to predict a 1D magnetic soliton pair existed by
tunning the thickness of the spacing layer between the two ferrimagnetic
layers. The decoupling-unlocking-locking transition of soliton motion is
determined at various interaction intensitiy. Our results have implications for
the manipulation of magnetic solitons and the design of magnetic soliton-based
logic devices.",2307.00471v1
2003-09-04,Coupled Cluster Method Calculations Of Quantum Magnets With Spins Of General Spin Quantum Number,"We present a new high-order coupled cluster method (CCM) formalism for the
ground states of lattice quantum spin systems for general spin quantum number,
$s$. This new ``general-$s$'' formalism is found to be highly suitable for a
computational implementation, and the technical details of this implementation
are given. To illustrate our new formalism we perform high-order CCM
calculations for the one-dimensional spin-half and spin-one antiferromagnetic
{\it XXZ} models and for the one-dimensional spin-half/spin-one ferrimagnetic
{\it XXZ} model. The results for the ground-state properties of the isotropic
points of these systems are seen to be in excellent quantitative agreement with
exact results for the special case of the spin-half antiferromagnet and results
of density matrix renormalisation group (DMRG) calculations for the other
systems. Extrapolated CCM results for the sublattice magnetisation of the
spin-half antiferromagnet closely follow the exact Bethe Ansatz solution, which
contains an infinite-order phase transition at $\Delta=1$. By contrast,
extrapolated CCM results for the sublattice magnetisation of the spin-one
antiferromagnet using this same scheme are seen to go to zero at $\Delta
\approx 1.2$, which is in excellent agreement with the value for the onset of
the Haldane phase for this model. Results for sublattice magnetisations of the
ferrimagnet for both the spin-half and spin-one spins are non-zero and finite
across a wide range of $\Delta$, up to and including the Heisenberg point at
$\Delta=1$.",0309099v1
2006-11-27,Subtle competition between ferromagnetic and antiferromagnetic order in a Mn(II) - free radical ferrimagnetic chain,"The macroscopic magnetic characterization of the Mn(II) - nitronyl nitroxide
free radical chain (Mn(hfac)2(R)-3MLNN) evidenced its transition from a
1-dimensional behavior of ferrimagnetic chains to a 3-dimensional ferromagnetic
long range order below 3 K. Neutron diffraction experiments, performed on a
single crystal around the transition temperature, led to a different conclusion
: the magnetic Bragg reflections detected below 3 K correspond to a canted
antiferromagnet where the magnetic moments are mainly oriented along the chain
axis. Surprisingly in the context of other compounds in this family of magnets,
the interchain coupling is antiferromagnetic. This state is shown to be very
fragile since a ferromagnetic interchain arrangement is recovered in a weak
magnetic field. This peculiar behavior might be explained by the competition
between dipolar interaction, shown to be responsible for the antiferromagnetic
long range order below 3 K, and exchange interaction, the balance between these
interactions being driven by the strong intrachain spin correlations. More
generally, this study underlines the need, in this kind of molecular compounds,
to go beyond macroscopic magnetization measurements.",0611684v2
2007-01-04,Exact solution of the mixed-spin Ising model on a decorated square lattice with two different kinds of decorating spins on horizontal and vertical bonds,"The mixed spin-(1/2, S_B, S_C) Ising model on a decorated square lattice with
two different kinds of decorating spins S_B and S_C placed on its horizontal
and vertical bonds, respectively, is exactly solved by establishing a precise
mapping relationship with the corresponding spin-1/2 Ising model on an
anisotropic square (rectangular) lattice. The effect of uniaxial single-ion
anisotropy acting on both types of decorating spins S_B and S_C is examined in
particular. If decorating spins S_B and S_C are integer and half-odd-integer,
respectively, or if the reverse is the case, the model under investigation
displays a very peculiar critical behavior beared on the spontaneously ordered
'quasi-1D' spin system, which appears as a result of the single-ion anisotropy
strengthening. We have found convincing evidence that this remarkable
spontaneous ordering virtually arises even though all integer-valued decorating
spins tend towards their 'non-magnetic' spin state S=0 and the system becomes
disordered only upon further increase of the single-ion anisotropy. The
single-ion anisotropy parameter is also at an origin of various temperature
dependences of the total magnetization when imposing the pure ferrimagnetic or
the mixed ferro-ferrimagnetic character of the spin arrangement.",0701071v2
2007-04-11,Heisenberg antiferromagnet with anisotropic exchange on the Kagome lattice: Description of the magnetic properties of volborthite,"We study the properties of the Heisenberg antiferromagnet with spatially
anisotropic nearest-neighbour exchange couplings on the kagome net, i.e. with
coupling J in one lattice direction and couplings J' along the other two
directions. For J/J' > 1, this model is believed to describe the magnetic
properties of the mineral volborthite. In the classical limit, it exhibits two
kinds of ground states: a ferrimagnetic state for J/J' < 1/2 and a large
manifold of canted spin states for J/J' > 1/2. To include quantum effects
self-consistently, we investigate the Sp(N) symmetric generalisation of the
original SU(2) symmetric model in the large-N limit. In addition to the
dependence on the anisotropy, the Sp(N) symmetric model depends on a parameter
kappa that measures the importance of quantum effects. Our numerical
calculations reveal that in the kappa-J/J' plane, the system shows a rich phase
diagram containing a ferrimagnetic phase, an incommensurate phase, and a
decoupled chain phase, the latter two with short- and long-range order. We
corroborate these results by showing that the boundaries between the various
phases and several other features of the Sp(N) phase diagram can be determined
by analytical calculations. Finally, the application of a block-spin
perturbation expansion to the trimerised version of the original spin-1/2 model
leads us to suggest that in the limit of strong anisotropy, J/J' >> 1, the
ground state of the original model is a collinearly ordered antiferromagnet,
which is separated from the incommensurate state by a quantum phase transition.",0704.1441v3
2008-01-09,Current-induced magnetization switching in MgO barrier magnetic tunnel junctions with CoFeB based synthetic ferrimagnetic free layers,"We investigated the effect of using a synthetic ferrimagnetic (SyF) free
layer in MgO-based magnetic tunnel junctions (MTJs) on current-induced
magnetization switching (CIMS), particularly for application to spin-transfer
torque random access memory (SPRAM). The employed SyF free layer had a
Co40Fe40B20/ Ru/ Co40Fe40B20 and Co20Fe60B20/Ru/Co20Fe60B20 structures, and the
MTJs(100x(150-300) nm^2) were annealed at 300oC. The use of SyF free layer
resulted in low intrinsic critical current density (Jc0) without degrading the
thermal-stability factor (E/kBT, where E, kB, and T are the energy potential,
the Boltzmann constant, and temperature,respectively). When the two CoFeB
layers of a strongly antiferromagnetically coupled SyF free layer had the same
thickness, Jc0 was reduced to 2-4x10^6 A/cm^2. This low Jc0 may be due to the
decreased effective volume under the large spin accumulation at the CoFeB/Ru.
The E/kBT was over 60, resulting in a retention time of over ten years and
suppression of the write current dispersion for SPRAM. The use of the SyF free
layer also resulted in a bistable (parallel/antiparallel) magnetization
configuration at zero field, enabling the realization of CIMS without the need
to apply external fields to compensate for the offset field.",0801.1355v1
2008-01-17,Towards the theory of ferrimagnetism,"Two-sublattice ferrimagnet, with spin-$s_1$ operators $\bf{S_{1i}}$ at the
sublattice $A$ site and spin-$s_2$ operators $\bf{S_{2i}}$ at the sublattice
$B$ site, is considered. The magnon of the system, the transversal fluctuation
of the total magnetization, is a complicate mixture of the transversal
fluctuations of the sublattice $A$ and $B$ spins. As a result, the magnons'
fluctuations suppress in a different way the magnetic orders of the $A$ and $B$
sublattices and one obtains two phases. At low temperature $(0,T^*)$ the
magnetic orders of the $A$ and $B$ spins contribute to the magnetization of the
system, while at the high temperature $(T^*,T_N)$, the magnetic order of the
spins with a weaker intra-sublattice exchange is suppressed by magnon
fluctuations, and only the spins with stronger intra-sublattice exchange has
non-zero spontaneous magnetization. The $T^*$ transition is a transition
between two spin-ordered phases in contrast to the transition from spin-ordered
state to disordered state ($T_N$-transition). There is no additional symmetry
breaking, and the Goldstone boson has a ferromagnetic dispersion in both
phases. A modified spin-wave theory is developed to describe the two phases.
All known Neel's anomalous $M(T)$ curves are reproduced, in particular that
with ""compensation point"". The theoretical curves are compared with
experimental ones for sulpho-spinel $MnCr2S_{4-x}Se_{x}$ and rare earth iron
garnets.",0801.2651v1
2008-02-13,Magnetoresistance behavior of a ferromagnetic shape memory alloy: Ni_1.75Mn_1.25Ga,"A negative-positive-negative switching behavior of magnetoresistance (MR)
with temperature is observed in a ferromagnetic shape memory alloy
Ni_1.75Mn_1.25Ga. In the austenitic phase between 300 and 120 K, MR is negative
due to s-d scattering. Curiously, below 120K MR is positive, while at still
lower temperatures in the martensitic phase, MR is negative again. The positive
MR cannot be explained by Lorentz contribution and is related to a magnetic
transition. Evidence for this is obtained from ab initio density functional
theory, a decrease in magnetization and resistivity upturn at 120 K. Theory
shows that a ferrimagnetic state with anti-ferromagnetic alignment between the
local magnetic moments of the Mn atoms is the energetically favoured ground
state. In the martensitic phase, there are two competing factors that govern
the MR behavior: a dominant negative trend up to the saturation field due to
the decrease of electron scattering at twin and domain boundaries; and a weaker
positive trend due to the ferrimagnetic nature of the magnetic state. MR
exhibits a hysteresis between heating and cooling that is related to the first
order nature of the martensitic phase transition.",0802.1801v2
2008-08-27,Magnetic phase evolution in the spinel compounds Zn$_{1-x}$Co$_x$Cr$_2$O$_4$,"We present the magnetic properties of complete solid solutions of
ZnCr$_2$O$_4$ and CoCr$_2$O$_4$: two well-studied oxide spinels with very
different magnetic ground states. ZnCr$_2$O$_4$, with non-magnetic $d^{10}$
cations occupying the A site and magnetic $d^3$ cations on the B site, is a
highly frustrated antiferromagnet. CoCr$_2$O$_4$, with magnetic $d^7$ cations
(three unpaired electrons) on the A site as well, exhibits both N\'eel
ferrimagnetism as well as commensurate and incommensurate non-collinear
magnetic order. More recently, CoCr$_2$O$_4$ has been studied extensively for
its polar behavior which arises from conical magnetic ordering. Gradually
introducing magnetism on the A site of ZnCr$_2$O$_4$ results in a transition
from frustrated antiferromagnetism to glassy magnetism at low concentrations of
Co, and eventually to ferrimagnetic and conical ground states at higher
concentrations. Real-space Monte-Carlo simulations of the magnetic
susceptibility suggest that the first magnetic ordering transition and features
of the susceptibility across $x$ are captured by near-neighbor self- and
cross-couplings between the magnetic A and B atoms. We present as a part of
this study, a method for displaying the temperature dependence of magnetic
susceptibility in a manner which helps distinguish between compounds possessing
purely antiferromagnetic interactions from compounds where other kinds of
ordering are present.",0808.3789v3
2010-04-28,"Synthesis, Structure and Properties of Tetragonal Sr2M3As2O2 (M3 = Mn3, Mn2Cu and MnZn2) Compounds Containing Alternating CuO2-Type and FeAs-Type Layers","Polycrystalline samples of Sr2Mn2CuAs2O2, Sr2Mn3As2O2, and Sr2Zn2MnAs2O2 were
synthesized. Their temperature- and applied magnetic field-dependent
structural, transport, thermal, and magnetic properties were characterized by
means of x-ray and neutron diffraction, electrical resistivity rho, heat
capacity, magnetization and magnetic susceptibility measurements. These
compounds have a body-centered-tetragonal crystal structure (space group
I4/mmm) that consists of MO2 (M = Zn and/or Mn) oxide layers similar to the
CuO2 layers in high superconducting transition temperature Tc cuprate
superconductors, and intermetallic MAs (M = Cu and/or Mn) layers similar to the
FeAs layers in high-Tc pnictides. These two types of layers alternate along the
crystallographic c-axis and are separated by Sr atoms. The site occupancies of
Mn, Cu and Zn were studied using Rietveld refinements of x-ray and neutron
powder diffraction data. The temperature dependences of rho suggest metallic
character for Sr2Mn2CuAs2O2 and semiconducting character for Sr2Mn3As2O2 and
Sr2Zn2MnAs2O2. Sr2Mn2CuAs2O2 is inferred to be a ferrimagnet with a Curie
temperature TC = 95(1) K. Remarkably, we find that the magnetic ground state
structure changes from a G-type antiferromagnetic structure in Sr2Mn3As2O2 to
an A-type ferrimagnetic structure in Sr2Mn2CuAs2O2 in which the Mn ions in each
layer are ferromagnetically aligned, but are antiferromagnetically aligned
between layers.",1004.5038v1
2010-07-01,Exactly solvable mixed-spin Ising-Heisenberg diamond chain with the biquadratic interactions and single-ion anisotropy,"An exactly solvable variant of mixed spin-(1/2,1) Ising-Heisenberg diamond
chain is considered. Vertical spin-1 dimers are taken as quantum ones with
Heisenberg bilinear and biquadratic interactions and with single-ion
anisotropy, while all interactions between spin-1 and spin-1/2 residing on the
intermediate sites are taken in the Ising form. The detailed analysis of the
$T=0$ ground state phase diagram is presented. The phase diagrams have shown to
be rather rich, demonstrating large variety of ground states: saturated one,
three ferrimagnetic with magnetization equal to 3/5 and another four
ferrimagnetic ground states with magnetization equal to 1/5. There are also two
frustrated macroscopically degenerated ground states which could exist at zero
magnetic filed.
  Solving the model exactly within classical transfer-matrix formalism we
obtain an exact expressions for all thermodynamic function of the system. The
thermodynamic properties of the model have been described exactly by exact
calculation of partition function within the direct classical transfer-matrix
formalism, the entries of transfer matrix, in their turn, contain the
information about quantum states of vertical spin-1 XXZ dimer (eigenvalues of
local hamiltonian for vertical link).",1007.0098v2
2011-02-24,"Unusual field-induced transitions in exactly solved mixed spin-(1/2,1) Ising chain with axial and rhombic zero-field splitting parameters","The mixed spin-(1/2,1) Ising chain with axial and rhombic zero-field
splitting parameters in a presence of the longitudinal magnetic field is
exactly solved within the framework of decoration-iteration transformation and
transfer-matrix method. Our particular emphasis is laid on an investigation of
the influence of the rhombic term, which is responsible for an onset of quantum
entanglement between two magnetic states S_k^z = 1 and -1 of the spin-1 atoms.
It is shown that the rhombic term gradually destroys a classical ferrimagnetic
order in the ground state and simultaneously causes diversity in magnetization
curves including intermediate plateau regions, regions with a continuous change
in the magnetization as well as several unusual field-induced transitions
accompanied with magnetization jumps. Another interesting findings concern with
an appearance of the round minimum in the temperature dependence of
susceptibility times temperature data, the double-peak zero-field specific heat
curves and the enhanced magnetocaloric effect. The temperature dependence of
the specific heat with three separate maxima may also be detected when driving
the system through the axial and rhombic zero-field splitting parameters close
enough to a phase boundary between the ferrimagnetic and disordered states and
applying sufficiently small longitudinal magnetic field.",1102.4928v1
2011-05-06,"Investigation of element-specific and bulk magnetism, electronic and crystal structures of La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3}","The magnetic interactions in La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3} (x = 0.15, 0.50
and 0.70) are investigated by x-ray absorption spectroscopy (XAS), x-ray
magnetic circular dichroism (XMCD), high-resolution x-ray powder diffraction,
and bulk magnetization measurements. XAS in the Mn and Cr L{2,3} edges support
stable single valent Cr{3+} ions and a varying Mn valence state with x, while
the O K edge XAS spectrum reveals local maxima in the O 2p density of states
close to the Fermi level due to mixing with Mn and Cr 3d states. A robust
antiferromagnetic state is found for x=0.70 below TN = 258 K. For x=0.15,
combined XMCD and bulk magnetization measurements indicate a fully polarized
ferrimagnetic state for the Mn and Cr spins below Tc=224 K. For x=0.50, a
reduced ferrimagnetic component dominated by Mn spins is present below Tc=154
K. No evidence of lattice anomalies due to cooperative charge and orbital
orderings is found by x-ray diffraction for all samples. The magnetic
properties of this system are rationalized in terms of a competition of
ferromagnetic Mn-Mn double exchange and antiferromagnetic Cr-Cr and Cr-Mn
superexchange interactions.",1105.1392v2
2011-07-05,Magnetocaloric effect and critical behavior near the paramagnetic to ferrimagnetic phase transition temperature in TbCo2-xFex,"Magnetocaloric effect (MCE) in TbCo2-xFex has been studied by dc
magnetization measurements.On substituting Fe in TbCo2, not only the magnetic
transition temperature is tuned to room temperature, but also the operating
temperature range for MCE is increased from 50 K for TbCo2 to 95 K for
TbCo1.9Fe0.1. The maximum magnetic entropy change (-{\Delta}SM) for
TbCo1.9Fe0.1 is found to be 3.7 J kg-1 K-1 for a 5 T field change, making it a
promising candidate for magnetic refrigeration near room temperature. The
temperature dependent neutron diffraction study shows a structural phase
transition (from cubic to rhombohedral phase with lowering of temperature)
which is associated with the magnetic phase transition and these transitions
broaden on Fe substitution. To investigate the nature of the paramagnetic to
ferrimagnetic phase transition, we performed a critical exponent study. From
the derived values of critical exponents, we conclude that TbCo2 belongs to the
3D Heisenberg class with short-range interaction, while on Fe substitution it
tends towards mean-field with long-range interaction. The derived values of
critical exponents represent the phenomenological universal curve for the field
dependence of {\Delta}SM, indicating that TbCo2 and TbCo1.9Fe0.1 belong to two
different universality classes.",1107.0866v1
2012-07-09,Dynamic phase transition properties and hysteretic behavior of a ferrimagnetic core-shell nanoparticle in the presence of a time dependent magnetic field,"We have presented dynamic phase transition features and stationary-state
behavior of a ferrimagnetic small nanoparticle system with a core-shell
structure. By means of detailed Monte Carlo simulations, a complete picture of
the phase diagrams and magnetization profiles have been presented and the
conditions for the occurrence of a compensation point $T_{comp}$ in the system
have been investigated. According to N\'{e}el nomenclature, the magnetization
curves of the particle have been found to obey P-type, N-type and Q-type
classification schemes under certain conditions. Much effort has been devoted
to investigation of hysteretic response of the particle and we observed the
existence of triple hysteresis loop behavior which originates from the
existence of a weak ferromagnetic core coupling $J_{c}/J_{sh}$, as well as a
strong antiferromagnetic interface exchange interaction $J_{int}/J_{sh}$. Most
of the calculations have been performed for a particle in the presence of
oscillating fields of very high frequencies and high amplitudes in comparison
with exchange interactions which resembles a magnetic system under the
influence of ultrafast switching fields. Particular attention has also been
paid on the influence of the particle size on the thermal and magnetic
properties, as well as magnetic features such as coercivity, remanence and
compensation temperature of the particle. We have found that in the presence of
ultrafast switching fields, the particle may exhibit a dynamic phase transition
from paramagnetic to a dynamically ordered phase with increasing ferromagnetic
shell thickness.",1207.2023v2
2012-08-20,Spin-1/2 Heisenberg antiferromagnet on an anisotropic kagome lattice,"We use the coupled cluster method to study the zero-temperature properties of
an extended two-dimensional Heisenberg antiferromagnet formed from spin-1/2
moments on an infinite spatially anisotropic kagome lattice of corner-sharing
isosceles triangles, with nearest-neighbor bonds only. The bonds have exchange
constants $J_{1}>0$ along two of the three lattice directions and $J_{2} \equiv
\kappa J_{1} > 0$ along the third. In the classical limit the ground-state (GS)
phase for $\kappa < 1/2$ has collinear ferrimagnetic (N\'{e}el$'$) order where
the $J_2$-coupled chain spins are ferromagnetically ordered in one direction
with the remaining spins aligned in the opposite direction, while for $\kappa >
1/2$ there exists an infinite GS family of canted ferrimagnetic spin states,
which are energetically degenerate. For the spin-1/2 case we find that quantum
analogs of both these classical states continue to exist as stable GS phases in
some regions of the anisotropy parameter $\kappa$, namely for
$0<\kappa<\kappa_{c_1}$ for the N\'{e}el$'$ state and for (at least part of)
the region $\kappa>\kappa_{c_2}$ for the canted phase. However, they are now
separated by a paramagnetic phase without either sort of magnetic order in the
region $\kappa_{c_1} < \kappa < \kappa_{c_2}$, which includes the isotropic
kagome point $\kappa = 1$ where the stable GS phase is now believed to be a
topological ($\mathbb{Z}_2$) spin liquid. Our best numerical estimates are
$\kappa_{c_1} = 0.515 \pm 0.015$ and $\kappa_{c_2} = 1.82 \pm 0.03$.",1208.3989v2
2012-12-02,Moderate interaction between 3d- and 4f-electrons and ferrimagnetism in Co-doped GdFeAsO,"We synthesized a series of GdFe$_{1-x}$Co$_x$AsO polycrystalline samples ($0
\leq x \leq 1$) by using a solid state reaction method and present a systematic
study on the physical properties by means of electrical resistivity $\rho(T)$,
magnetic susceptibility $\chi(T)$ and specific heat $C(T)$. The parent compound
GdFeAsO undergoes a spin-density-wave (SDW) transition associated with Fe
3d-electrons around 130 K, followed by an antiferromagnetic (AFM) transition of
Gd at $T^\textup{Gd}_\textup{N} \approx$ 4 K. The SDW transition is quickly
suppressed by Fe/Co substitution and superconductivity appears in a narrow
doping range of $0.05 < x < 0.25$, showing a maximum $T_\textup{sc}$ $\approx$
20 K around $x = 0.1$. On the other hand, the 4f-electrons of Gd are
antiferromagnetically ordered over the entire doping concentration ($0 \leq x
\leq 1$), while the Co 3d-electrons exhibit a ferromagnetic (FM) transition
above $x \approx 0.8$, with the Curie temperature ($T^\textup{Co}_\textup{C}$)
reaching 75 K in GdCoAsO. These two magnetic species (Gd and Co) are coupled
antiferromagnetically to give rise to ferrimagnetic behavior in magnetic
susceptibility on the Co-rich side. For $0.7 \leq x < 1.0$, the system
undergoes a possible magnetic reorientation below $T^\textup{Gd}_\textup{N}$.",1212.0222v1
2012-12-12,Ferrimagnetism and spin canting of ZnFe2O4 nanoparticles embedded in ZnO matrix,"The structural and magnetic properties of ZnFe2O4 nanoparticles embedded in a
non-magnetic ZnO matrix are presented. X-ray diffractograms and Transmission
Electron Microscopy (TEM) images showed that the resulting samples are composed
of crystalline ferrite nanoparticles with average crystallite size <D> =
23.4(0.9) nm, uniformly dispersed within the ZnO matrix. Magnetization data
indicated a superparamagnetic-like behavior from room temperature down to T_{M}
~ 20 K, where a transition to a frozen state is observed. The M(H) curves
displayed nearly zero coercive field down to TM, where a sharp increase in the
H_C value is observed. The measured saturation magnetization M_S values at 200
and 2 K were M_S = 0.028(3) and 0.134(7) muB/f.u. ZnFe2O4 respectively, showing
the existence of small amounts of non compensated atomic moments. M\""ossbauer
measurements at low temperatures confirmed the transition to a magnetically
ordered state for T < 25 K, where two magnetically split sextets develop.
Whereas these two sextets show strong overlap due to the similar hyperfine
fields, in-field M\""ossbauer spectra clearly showed two different Fe3+ sites,
demonstrating that the sample is ferrimagnetically ordered. The two spinel
sites are found to behave differently under an external field of 12 T: whereas
the moments located at A sites show a perfect alignment with the external
field, spins at B sites are canted by an angle alpha_B = 49(2){\deg}. We
discuss the significance of this particle structure for the observed magnetic
behavior.",1212.2798v1
2015-02-27,Effects of chemical pressure on the magnetic ground states of the osmate double perovskites SrCaCoOsO6 and Ca2CoOsO6,"The magnetic ground state in the double perovskite system Sr2-xCaxCoOsO6
changes from an antiferromagnet (x = 0), to a spin glass (x = 1), to a
ferrimagnet (x = 2) as the Ca content increases. This crossover is driven by
chemical pressure effects that control the relative strength of magnetic
exchange interactions. The synthesis, crystal structure, and magnetism of
SrCaCoOsO6 and Ca2CoOsO6 are investigated and compared with Sr2CoOsO6. Both
compounds adopt a monoclinic crystal structure with rock salt ordering of Co2+
and Os6+ and a-a-b+ octahedral tilting, but the average Co-O-Os bond angle
evolves from 158.0(3) degrees in SrCaCoOsO6 to 150.54(9) degrees in Ca2CoOsO6
as the smaller Ca2+ ion replaces Sr2+. While this change may seem minor it has
a profound effect on the magnetism, changing the magnetic ground state from
antiferromagnetic in Sr2CoOsO6 (TN1 = 108 K, TN2 = 70 K), to a spin glass in
SrCaCoOsO6 (Tf1 = 32 K, Tf2 = 13 K), to ferrimagnetic in Ca2CoOsO6 (TC = 145
K). In the first two compounds the observation of two transitions is consistent
with weak coupling between the Co and Os sublattices.",1503.00029v3
2015-05-14,"First-principles calculations of exchange interactions, spin waves, and temperature dependence of magnetization in inverse-Heusler-based spin gapless semiconductors","Employing first principles electronic structure calculations in conjunction
with the frozen-magnon method we calculate exchange interactions, spin-wave
dispersion, and spin-wave stiffness constants in inverse-Heusler-based spin
gapless semiconductor (SGS) compounds Mn$_2$CoAl, Ti$_2$MnAl, Cr$_2$ZnSi,
Ti$_2$CoSi and Ti$_2$VAs. We find that their magnetic behavior is similar to
the half-metallic ferromagnetic full-Heusler alloys, i.e., the intersublattice
exchange interactions play an essential role in the formation of the magnetic
ground state and in determining the Curie temperature, $T_\mathrm{c}$. All
compounds, except Ti$_2$CoSi possess a ferrimagnetic ground state. Due to the
finite energy gap in one spin channel, the exchange interactions decay sharply
with the distance, and hence magnetism of these SGSs can be described
considering only nearest and next-nearest neighbor exchange interactions. The
calculated spin-wave dispersion curves are typical for ferrimagnets and
ferromagnets. The spin-wave stiffness constants turn out to be larger than
those of the elementary 3$d$-ferromagnets. Calculated exchange parameters are
used as input to determine the temperature dependence of the magnetization and
$T_\mathrm{c}$ of the SGSs. We find that the $T_\mathrm{c}$ of all compounds is
much above the room temperature. The calculated magnetization curve for
Mn$_2$CoAl as well as the Curie temperature are in very good agreement with
available experimental data. The present study is expected to pave the way for
a deeper understanding of the magnetic properties of the inverse-Heusler-based
SGSs and enhance the interest in these materials for application in spintronic
and magnetoelectronic devices.",1505.03632v1
2016-02-26,Magnetic evolution of Spinel Mn1-xZnxCr2O4 single crystals,"Mn1-xZnxCr2O4 (0<x<1) single crystals have been grown by the chemical vapor
transport (CVT) method. The crystallographic, magnetic, and thermal transport
properties of the single crystals were investigated by the room-temperature
X-ray diffraction, magnetization M(T) and specific heat CP(T) measurements.
Mn1-xZnxCr2O4 crystals show a cubic structure, the lattice constant a decreases
with the increasing content x of the doped Zn2+ ions and follows the Vegard
law. Based on the magnetization and heat capacity measurements, the magnetic
evolution of Mn1-xZnxCr2O4 crystals has been discussed. For 0<x<0.3, the
magnetic ground state is the coexistence of the collinear ferrimagnetic order
(CFIM) and spiral ferrimagnetic one (SFIM), which is similar to that of the
parent MnCr2O4. When x changes from 0.3 to 0.8, the SFIM is progressively
suppressed and spin glass-like behavior is observed. When x is above 0.8, an
antiferromagnetic (AFM) order presents. At the same time, the magnetic specific
heat (Cmag.) was also investigated and the results are coincident with the
magnetic measurements. The possible reasons based on the disorder effect and
the reduced molecular field effect induced by the substitution of Mn2+ ions by
nonmagnetic Zn2+ ones in Mn1-xZnxCr2O4 crystals have been discussed.",1602.08178v1
2016-02-26,Two types of all-optical magnetization switching mechanisms using femtosecond laser pulses,"Magnetization manipulation in the absence of an external magnetic field is a
topic of great interest, since many novel physical phenomena need to be
understood and promising new applications can be imagined. Cutting-edge
experiments have shown the capability to switch the magnetization of magnetic
thin films using ultrashort polarized laser pulses. In 2007, it was first
observed that the magnetization switching for GdFeCo alloy thin films was
helicity-dependent and later helicity-independent switching was also
demonstrated on the same material. Recently, all-optical switching has also
been discovered for a much larger variety of magnetic materials (ferrimagnetic,
ferromagnetic films and granular nanostructures), where the theoretical models
explaining the switching in GdFeCo films do not appear to apply, thus
questioning the uniqueness of the microscopic origin of all-optical switching.
Here, we show that two different all-optical switching mechanisms can be
distinguished; a ""single pulse"" switching and a ""cumulative"" switching process
whose rich microscopic origin is discussed. We demonstrate that the latter is a
two-step mechanism; a heat-driven demagnetization followed by a
helicity-dependent remagnetization. This is achieved by an all-electrical and
time-dependent investigation of the all-optical switching in ferrimagnetic and
ferromagnetic Hall crosses via the anomalous Hall effect, enabling to probe the
all-optical switching on different timescales.",1602.08525v2
2016-03-01,Ordering phenomena in a heterostructure of frustrated and unfrustrated triangular-lattice Ising layers,"We study critical and magnetic properties of a bilayer Ising system
consisting of two triangular planes A and B, with the antiferromagnetic (AF)
coupling $J_{\rm A}$ and the ferromagnetic (FM) one $J_{\rm B}$ for the
respective layers, which are coupled by the interlayer interaction $J_{\rm AB}$
by using Monte Carlo simulations. When $J_{\rm A}$ and $J_{\rm B}$ are of the
same order, the unfrustrated FM plane orders first at a high temperature
$T_{c1} \sim J_{\rm B}$. The spontaneous FM order then exerts influence on the
other frustrated AF plane as an effective magnetic field, which subsequently
induces a ferrimagnetic order in this plane at low temperatures below $T_{c2}$.
When short-range order is developed in the AF plane while the influence of the
FM plane is still small, there appears a preemptive
Berezinskii-Kosterlitz-Thouless-like pseudocritical crossover regime just above
the ferrimagnetic phase transition point, where the short-distance behavior up
to a rather large length scale exponentially diverging in $\propto \JA / T$ is
controlled by a line of Gaussian fixed points at $T = 0$. In the crossover
region, a continuous variation in the effective critical exponent $4/9 \lesssim
\eta^{\rm eff} \lesssim 1/2$ is observed. The phase diagram by changing the
ratio $J_{\rm A}/J_{\rm B}$ is also investigated.",1603.00256v2
2016-04-27,Very low critical current density for motion of coupled domain walls in synthetic ferrimagnet nanowires,"Domain walls in ferromagnetic nanowires are potential building-blocks of
future technologies such as racetrack memories, in which data encoded in the
domain walls are transported using spin-polarised currents. However, the
development of energy-efficient devices has been hampered by the high current
densities needed to initiate domain wall motion. We show here that a remarkable
reduction in the critical current density can be achieved for in-plane
magnetised coupled domain walls in CoFe/Ru/CoFe synthetic ferrimagnet tracks.
The antiferromagnetic exchange coupling between the layers leads to simple
N\'{e}el wall structures, imaged using photoemission electron and Lorentz
transmission electron microscopy, with a width of only $\sim 100$~nm. The
measured critical current density to set these walls in motion, detected using
magnetotransport measurements, is $1.0 \times 10^{11}$~Am$^{-2}$, almost an
order of magnitude lower than in a ferromagnetically coupled control sample.
Theoretical modelling indicates that this is due to nonadiabatic driving of
anisotropically coupled walls, a mechanism that can be used to design efficient
domain-wall devices.",1604.07992v4
2016-06-14,Ultrafast Spin-Transfer-Torque Switching of Synthetic Ferrimagnets,"The switching speed and the write current required for spin-transfer-torque
reversal of spintronic devices such as magnetic tunnel junctions (MTJ)
currently hinder their wide implementation into memory and logic devices. This
problem is further exacerbated as the dimensions of MTJ nanostructures are
scaled down to tens of nanometers in diameter, as higher magnetic anisotropy
materials are required to meet thermal stability requirements that demand
higher switching current densities. Here, we propose a simple solution to these
issues based on synthetic ferrimagnet (SFM) structures. It is commonly assumed
that to achieve a given switching delay, the current has to exceed the critical
current by a certain factor and so a higher critical current implies a higher
switching current. We show that this is not the case for SFM structures which
can provide significantly reduced switching delay for a given current density,
even though the critical current is increased. This non-intuitive result can be
understood from the requirements of angular momentum conservation. We conclude
that a 20 nm diameter MTJ incorporating the proposed SFM free layer structure
can be switched in tens of picosecond time scales. This remarkable switching
speed can be attained by employing current perpendicular magnetic anisotropy
materials with experimentally demonstrated exchange coupling strengths.",1606.04428v2
2016-09-24,Graphene-based synthetic antiferromagnets and ferrimagnets,"Hybrid Graphene/magnetic structures offer a unique playground for fundamental
research, and opportunities for emerging technologies. Graphene-spaced
ultrathin structures with antiferromagnetic exchange-coupling (AFC) seem a
relevant scenario, analogous to that of conventional metallic multilayer
devices. Unfortunately, the AFC found so far between bulk magnetic single
crystals and Graphene-spaced adatoms, clusters or molecules either requires low
temperatures, is too weak, or of complex nature, for realistic exploitation.
Here we show theoretically and experimentally that a strong perpendicular AFC
can be established in ultrahin-film structures such as Fe/Gr/Co on Ir(111),
first-time enabling Graphene-based synthetic antiferromagnet and ferrimagnet
materials with unprecedented magnetic properties and appearing suitable for
applications. Remarkably, the established AFC is robust on structure
thicknesses, thermally stable up to room temperature, very strong but
field-controllable, and occurs in perpendicular orientation with opposite high
remanent layer magnetizations. Our atomistic first-principle simulations
provide further ground for the feasibility of Graphene-mediated AFC ultra-thin
film structures, revealing that Graphene acts not only as mere spacer but has a
direct role in sustaining antiferromagnetic superexchange-coupling between the
magnetic layers. These results provide a path for the design of unique and
ultimately-thin synthetic antiferromagnetic structures, which seem exciting for
fundamental nanoscience studies or for potential use in Graphene-spintronics
applications.",1609.07634v1
2018-02-06,Spin transport in multilayer systems with fully epitaxial NiO thin films,"We report on the generation and transport of thermal spin currents in fully
epitaxial {\gamma}-Fe$_2$O$_3$/NiO(001)/Pt and Fe$_3$O$_4$/NiO(001)/Pt
trilayers. A thermal gradient, perpendicular to the plane of the sample,
generates a magnonic spin current in the ferrimagnetic maghemite
({\gamma}-Fe$_2$O$_3$) and magnetite (Fe$_3$O$_4$) thin films by means of the
spin Seebeck effect. The spin current propagates across the epitaxial,
antiferromagnetic insulating NiO layer, before being detected in the Pt layer
by the inverse spin Hall effect. The transport of the spin signal is studied as
a function of the NiO thickness, temperature and ferrimagnetic material where
the spin current is generated. In epitaxial NiO grown on maghemite, the spin
Seebeck signal decays exponentially as a function of the NiO thickness, with a
spin-diffusion length for thermally-generated magnons of {\lambda}$_{MSDL}$ =
$1.6 \pm 0.2$ nm, largely independent on temperature. We see no enhancement of
the spin current signal as previously reported for certain temperatures and
thicknesses of the NiO. In epitaxial NiO grown on magnetite, the
temperature-averaged spin diffusion length is {\lambda}$_{MSDL}$ = $3.8 \pm
0.3$ nm, and we observe an enhancement of the spin signal when the NiO
thickness is 0.8 nm, demonstrating that the growth conditions dramatically
affect the spin transport properties of the NiO even for full epitaxial growth.
In contrast to theoretical predictions for coherent spin transport, we do not
see vastly different spin diffusion lengths between epitaxial and
polycrystalline NiO layers.",1802.01844v1
2018-04-06,Spin Seebeck effect in $\varepsilon$-Fe$_2$O$_3$ thin layer with high coercive field,"Spin Seebeck effect has been investigated in Pt/$\varepsilon$-Fe$_2$O$_3$
bilayers. The $\varepsilon$-Fe$_2$O$_3$ thin layer with $40-70$~nm thickness
were deposited by a spin-coating method on Y:ZrO$_2$(100) substrates. The
prepared layers are highly oriented with the easy magnetic $a$-axis parallel to
the film surface. The magnetic hysteresis loops measured at room temperature
with magnetic field parallel to the layer exhibit coercive fields up to
11.6~kOe, which is so far the highest value measured for
$\varepsilon$-Fe$_2$O$_3$ thin layer samples. The shape of the spin Seebeck
hysteresis loops is similar to the shape of magnetization for single phase
layers with coercive field around 10~kOe. In some prepared layers a small
amount of secondary soft ferrimagnetic phase is revealed by a constricted shape
of magnetization loops, in contrast to spin Seebeck loops, where no
constriction is observed. A difference in encountered in the case of layers
with a small amount ($1-2$~volume\%) of secondary soft ferrimagnetic phase,
which is revealed by a constricted shape of magnetization loops, in contrast to
spin Seebeck loops, where no constriction is observed.",1804.02159v1
2018-04-13,Tuning spin one channel to exotic orbital two-channel Kondo effect in ferrimagnetic composites of LaNiO3 and CoFe2O4,"We report the tuning from spin one channel (1CK) to orbital two-channel Kondo
(2CK) effect by varying CoFe2O4 (CFO) content in the composites with LaNiO3
(LNO) along with the presence of ferrimagnetism. Although there is no signature
of resistivity upturn in case of pure LNO, all the composites exhibit a
distinct upturn in the temperature range 30-80 K. For composite with lower
percentage of CFO (10 %), the electron spin plays the key role in the emergence
of resistivity upturn which is affected by external magnetic field. On the
other hand, when the CFO content is increased (15%), the upturn shows strong
robustness against high magnetic field (14 T) and a crossover in temperature
variation from lnT to T^1/2 at the Kondo temperature, indicating the appearance
of orbital 2CK effect. The orbital 2CK effect is originated due to the
scattering of conduction electrons from the structural two-level systems which
is created at the interfaces between the two phases (LNO and CFO) of different
crystal structures as well as inside the crystal planes. A negative
magnetoresistance (MR) is observed at low temperature (< 30 K) for composites
containing both lower (10 %) and higher percentage (15 %) of CFO. We have
analyzed the negative MR using Khosla and Fisher semi-empirical model based on
spin dependent scattering of conduction electrons from localized spins.",1804.04796v1
2018-11-21,"Exploring interfacial exchange coupling and sublattice effect in heavy metal/ferrimagnetic insulator heterostructures using Hall measurements, x-ray magnetic circular dichroism, and neutron reflectometry","We use temperature-dependent Hall measurements to identify contributions of
spin Hall, magnetic proximity, and sublattice effects to the anomalous Hall
signal in heavy metal/ferrimagnetic insulator heterostructures with
perpendicular magnetic anisotropy. This approach enables detection of both the
magnetic proximity effect onset temperature and the magnetization compensation
temperature and provides essential information regarding the interfacial
exchange coupling. Onset of a magnetic proximity effect yields a local extremum
in the temperature-dependent anomalous Hall signal, which occurs at higher
temperature as magnetic insulator thickness increases. This magnetic proximity
effect onset occurs at much higher temperature in Pt than W. The magnetization
compensation point is identified by a sharp anomalous Hall sign change and
divergent coercive field. We directly probe the magnetic proximity effect using
x-ray magnetic circular dichroism and polarized neutron reflectometry, which
reveal an antiferromagnetic coupling between W and the magnetic insulator.
Finally, we summarize the exchange-coupling configurations and the anomalous
Hall-effect sign of the magnetized heavy metal in various heavy metal/magnetic
insulator heterostructures.",1811.08574v2
2020-07-30,Coexistence of topological Weyl and nodal-ring states in ferromagnetic and ferrimagnetic double perovskites,"Magnetic topological quantum materials have attracted great attention due to
their exotic topological quantum physics induced by the interplay among
crystalology, magnetism, and topology, which is of profound importance to
fundamental research and technology applications. However, limited materials
are experimentally available, most of whom are realized by magnetic impurity
doping or heterostructural constructions. In this work, based on the
first-principles calculations, we predict that double perovskite Ba2CdReO6 is
an intrinsic ferromagnetic topological semi-half-metal, while the ferrimagnetic
double perovskite with space group symmetry Fm-3m, such as Ba2FeMoO6, belongs
to a topological half-metal. One pair of Weyl points and fully spin-polarized
nodal-ring states are found in the vicinity of the Fermi level in Ba2CdReO6.
Its two-dimensional nearly flat drumhead surface states are fully
spin-polarized. In Ba2FeMoO6, however, there exist four pairs of Weyl points
and two fully spin-polarized nodal-rings near the Fermi level. These
topological properties are stable in the presence of spin-orbit coupling. This
makes these materials be an appropriate platform for studying the emerging
intriguing properties, especially for the applications in spintronics,
information technology, and topological superconductivity.",2007.15699v3
2016-11-21,Purely Antiferromagnetic Magnetoelectric Random Access Memory,"Magnetic random access memory schemes employing magnetoelectric coupling to
write binary information promise outstanding energy efficiency. We propose and
demonstrate a purely antiferromagnetic magnetoelectric random access memory
(AF-MERAM) that offers a remarkable 50 fold reduction of the writing threshold
compared to ferromagnet-based counterparts, is robust against magnetic
disturbances and exhibits no ferromagnetic hysteresis losses. Using the
magnetoelectric antiferromagnet Cr2O3, we demonstrate reliable isothermal
switching via gate voltage pulses and all-electric readout at room temperature.
As no ferromagnetic component is present in the system, the writing magnetic
field does not need to be pulsed for readout, allowing permanent magnets to be
used. Based on our prototypes of these novel systems, we construct a
comprehensive model of the magnetoelectric selection mechanism in thin films of
magnetoelectric antiferromagnets. We identify that growth induced effects lead
to emergent ferrimagnetism, which is detrimental to the robustness of the
storage. After pinpointing lattice misfit as the likely origin, we provide
routes to enhance or mitigate this emergent ferrimagnetism as desired. Beyond
memory applications, the AF-MERAM concept introduces a general all-electric
interface for antiferromagnets and should find wide applicability in purely
antiferromagnetic spintronics devices.",1611.07027v1
2011-11-12,Half-metallic Ferrimagnetism Driven by Coulomb Enhanced Spin-Orbit Coupling in PdCrO3,"Recently, in the seemingly narrow gap insulating NiCrO$_3$ with the
trigonally distorted (R-3c) perovskite-like structure, a compensated half-metal
(CHM) is predicted, as applying a modest pressure. Using ab initio calculations
including both Coulomb correlations and spin-orbit coupling (SOC), we
investigate the as-yet-unsynthesized PdCrO$_3$, isostructural and isovalent to
NiCrO$_3$. Upon applying the on-site Coulomb repulsion $U$ to both Pd and Cr
ions, the Cr spin moment is precisely compensated with the antialigned spin
moments of Pd and oxygens. Coincidentally only one spin channel remains
metallic due to the twice larger width of the Pd 4d bands than the Ni 3d bands
in NiCrO$_3$, indicating CHM in ambient pressure. Inclusion of SOC as well as
correlation effects (LDA+U+SOC) produces a SOC constant enhanced twice over the
value of LDA+SOC, leading to unusually large orbital moment of --0.25 $\mu_B$
on Pd. However, the half-metallicity still survives, so that a transition of
CHM to a half-metallic ferrimagnet occurs due to Coulomb enhanced SOC. On the
other hand, an isovalent, but presumed cubic double perovskite La$_2$PdCrO$_6$
is expected to be a half-metal ferromagnet with tiny orbital moments.",1111.2911v1
2016-08-09,Compensated ferrimagnetic tetragonal Heusler thin films for antiferromagnetic spintronics,"In recent years, antiferromagnetic spintronics has received much attention
since ideal antiferromagnets do not produce stray fields and are much more
stable to external magnetic fields compared to materials with net
magnetization. Akin to antiferromagnets, compensated ferrimagnets have zero net
magnetization but have the potential for large spin-polarization and strong out
of plane magnetic anisotropy, and, hence, are ideal candidates for high density
memory applications. Here, we demonstrate that a fully compensated magnetic
state with a tunable magnetic anisotropy is realized in Mn-Pt-Ga based
tetragonal Heusler thin films. Furthermore, we show that a bilayer formed from
a fully compensated and a partially compensated Mn-Pt-Ga layer, exhibits a
large interfacial exchange bias up to room temperature. The present work
establishes a novel design principle for spintronic devices that are formed
from materials with similar elemental compositions and nearly identical crystal
and electronic structures. Such devices are of significant practical value due
to their improved properties such as thermal stability. The flexible nature of
Heusler materials to achieve tunable magnetizations, and anisotropies within
closely matched materials provides a new direction to the growing field of
antiferromagnetic spintronics.",1608.02887v1
2017-10-27,"Near total magnetic moment compensation without reduction in T_C of Mn_2 V_0.5 Co_0.5 Z (Z=Ga,Al) Heusler compounds","Mn_2V_1-xCo_xZ (Z=Ga,Al and x=0, 0.25, 0.5, 0.75, 1) Heusler compounds have
been synthesized to investigate the effect of Co substitution at the V site on
the magnetic moment and Curie temperatures of half-metallic ferrimagnets
Mn_2VGa and Mn_2VAl. The Co substituted compounds show a non linear decrease in
lattice parameter without altering the crystal structure of the parent
compounds. The end members Mn_2VGa and Mn_2CoGa have the saturation
magnetization of 1.80 {\mu}_B/f.u and 2.05 {\mu}_B/f.u respectively whereas for
the Mn_2V_0.5Co_0.5Ga compound, a near total magnetic moment compensation (0.10
{\mu}_B/f.u) was observed due to the ferrimagnetic coupling of Mn with
parallelly aligned V and Co. The Co substituted Mn_2VAl has also shown the
similar trend with compensated magnetic moment value of 0.06 {\mu}_B/f.u for
x=0.5. The Curie temperatures of the compounds including the x=0.5 composition
are well above the room temperature (more than 700 K) which is in sharp
contrast to the earlier reported values of 171 K for the (MnCo)VGa and 105 K
for the (MnCo)VAl compounds (substitution at the Mn site). The magnetic moment
compensation without significant reduction in T_C indicates that the V site
substitution of Co does not weaken the magnetic interaction in Mn_2VZ (Z=Ga,
Al) compounds which is in contrary to the earlier experimental reports on Mn
site substitution.",1710.09971v1
2018-09-03,Vanishing skyrmion Hall effect at the angular momentum compensation temperature of a ferrimagnet,"Charged particles exhibit the Hall effect in the presence of magnetic fields.
Analogously, ferromagnetic skyrmions with non-zero topological charges and
finite fictitious magnetic fields exhibit the skyrmion Hall effect, which is
detrimental for applications. The skyrmion Hall effect has been theoretically
predicted to vanish for antiferromagnetic skyrmions because the fictitious
magnetic field, proportional to net spin density, is zero. We experimentally
confirm this prediction by observing current-driven transverse elongation of
pinned ferrimagnetic bubbles. Remarkably, the skyrmion Hall effect, estimated
with the angle between the current and bubble elongation directions, vanishes
at the angular momentum compensation temperature where the net spin density
vanishes. This study establishes a direct connection between the fictitious
magnetic field and spin density, offering a pathway towards the realization of
skyrmionic devices.",1809.00415v1
2018-09-20,"Electronic and Magnetic Properties of the Candidate Magnetocaloric-Material Double Perovskites La$_2$MnCoO$_6$, La$_2$MnNiO$_6$ and La$_2$MnFeO$_6$","The search for room-temperature magnetocaloric materials for refrigeration
has led to investigations of double perovskites. In particular, a puzzle has
appeared in the La$_2$MnNiO$_6$, La$_2$MnCoO$_6$ and La$_2$MnFeO$_6$ family of
compounds. They share the same crystal structure, but while La$_2$MnNiO$_6$ and
La$_2$MnCoO$_6$ are ferromagnets below room temperature, La$_2$MnFeO$_6$,
contrary to simple expectations, is a ferrimagnet. To solve this puzzle, we use
density-functional theory calculations to investigate the electronic structure
and magnetic exchange interactions of the ordered double perovskites. Our study
reveals the critical role played by local electron-electron interaction in the
Fe-$d$ orbital to promote the Fe$^{3+}$ valence state with half-filled
$d$-shell over Fe$^{2+}$ and to establish a ferrimagnetic ground state for
La$_2$MnFeO$_6$. The importance of Hund's coupling and Jahn-Teller distortion
on the Mn$^{4+}$ ion is also pointed out. Exchange constants are extracted by
comparing different magnetically ordered states. Mean-field and classical
Monte-Carlo calculations on the resulting model give trends in $T_C$ that are
in agreement with experiments on this family of materials.",1809.07812v1
2018-09-20,Electronic and Magnetic Properties of double-perovskites La$_2$MnRuO$_6$ and Hole-Doped La$_2$MnFeO$_6$ and their Potential for Magnetic Refrigeration,"Magnetic refrigeration at room-temperature is a technology that could
potentially be more environmentally-friendly, efficient and affordable than
traditional refrigeration. The search for suitable materials for magnetocaloric
refrigeration led to the study of double-perovskites La$_2$MnNiO$_6$,
La$_2$MnCoO$_6$ and La$_2$MnFeO$_6$. While La$_2$MnNiO$_6$ and La$_2$MnCoO$_6$
are ferromagnets with near room-temperature $T_C$s, previous theoretical study
of double-perovskite La$_2$MnFeO$_6$ revealed that this material is a
ferrimagnet due to strong electronic interactions in Fe-$d$ orbitals. Here, we
investigate the double-perovskites La$_2$MnRuO$_6$ and LaA''MnFeO$_6$ (A'' =
Ba, Ca and Sr) with density functional theory (DFT) as materials that can
counteract the effects the strong repulsion present in the in Fe-$d$ shells of
La$_2$MnFeO$_6$ and lead to a ferromagnetic state. Our study reaveals that
while La$_2$MnRuO$_6$ is also a ferrimagnet, but with a higher net magnetic
moment per formula than La$_2$MnFeO$_6$, doubly-ordered LaA''MnFeO$_6$ are
ferromagnets. By mapping the total energy of the LaA''MnFeO$_6$ compounds
obtained from DFT calculations to the Ising model, we also calculate their
magnetic exchange couplings. This allows us to estimate the trend in $T_C$ of
the three doped La$_2$MnFeO$_6$ materials with classical Monte-Carlo
calculations and predict that doubly-ordered LaBaMnFeO$_6$ and LaSrMnFeO$_6$
could be suitable materials for room-temperature magnetic refrigeration.",1809.07813v2
2018-09-28,Hydrogen adsorption-induced nanomagnetism at the Si(111)-(7$\times$7) surface,"The creation of magnetism on non-magnetic semiconductor surfaces is of
importance for the realization of spintronics devices. Especially, the coupling
of electron spins within quantum nanostructures can be utilized for
nanomagnetism applications. Here, we demonstrate, based on first-principles
density-functional theory calculations, that the adsorption of H atoms on the
Si(111)-(7$\times$7) surface induces the spin polarization of surrounding Si
dangling bonds (DBs) and their spin orderings. It is revealed that the H
adsorption on a rest-atom site exhibits a Jahn-Teller-like distortion that
accompanies a charge transfer from the rest atom to the nearest neighboring
adatoms. This charge transfer increases the local density of states of such
three adatoms at the Fermi level, thereby inducing a Stoner-type instability to
produce a ferrimagnetic order of adatom DBs around the adsorbed H atom.
Meanwhile, the H adsorption on an adatom site cannot induce spin polarization,
but, as adsorbed H atoms increase, the ferrimagnetic order of rest-atom DBs
emerges through the charge transfer from rest atoms to adatoms. Our findings
provide a microscopic mechanism of the H-induced spin orderings of Si DBs at
the atomic scale, which paves a novel way to the design of nanoscale magnetism
in the representative semiconductor surface.",1809.10880v1
2018-10-11,Geometrically frustrated Ising-Heisenberg spin model on expanded Kagomé lattice,"Here we consider the Ising-Heisenberg model in the expanded Kagom\'e lattice,
also known as triangle-dodecagon (3-12) or star lattice. This model can still
be understood as a decorated honeycomb lattice. Assuming that the Heisenberg
spins are at the vertices of the triangle while other spins are of the Ising
type. Thus, this model is equivalent to an effective Kagom\'e Ising lattice,
through the decoration transformation technique. Thus this means that the model
is exactly solvable so we can study the most relevant properties of this model.
Like the phase diagram at zero temperature, exhibiting a frustrated phase, a
ferromagnetic phase, a classical ferrimagnetic phase and a quantum
ferrimagnetic phase. We observed that Heisenberg spin exchange interaction
influences the frustrated phase, but we rigorously verify that the magnitude
and origin of the frustration emerge in a similar way to antiferromagnetic
Ising Kagom\'e lattice. Likewise, the thermodynamic properties of the model can
also be obtained, such as the critical temperature as a dependence of the
Hamiltonian parameters and the spontaneous magnetization of the model. Besides,
we investigated the entropy of the model, identifying its residual entropy in
the frustrated region. Even we analyze the specific heat behavior as a
temperature dependence, to deal with the phase transition.",1810.05235v2
2019-06-04,Field driven phase transition from semiconductor to half-metallic ferrimagnet of TcO2 uni-cell layer on rutile TiO2(001) surface,"For spintronics applications, it is highly desirable to realize
highly-spin-polarized two-dimensional (2D) electron systems in
electrically-controllable epitaxial ultrathin films on semiconductor
substrates. Through systematic first-principles investigation, we propose the
TcO$_2$ uni-cell layer (one-unit-cell thickness) on rutile TiO$_2$ (001)
substrate as a semiconductor heterostructure and use electric field to
manipulate its electronic and magnetic properties. Our study shows that the
heterostructure is a narrow-gap semiconductor with an antiferromagnet-like
ordering when the applied electric field is less than 0.026 V/\AA{}, and then
it transits to a half-metallic ferrimagnet with 100\% spin polarization. Our
further analysis indicates that the magnetization density and the electronic
states near the Fermi level originate mainly from the TcO$_2$ uni-cell layer,
with the remaining minor part from the interfacial Ti-O$_2$ monolayers, and the
bonds and bond angles quickly converge to the corresponding values of bulk
TiO$_2$ when crossing the interface and entering the TiO$_2$ layer. Therefore,
the heterostructure is actually a 2D electron system determined by the TcO$_2$
uni-cell layer and the TiO$_2$ substrate. Because the half-metallic phase with
100\% spin polarization can be achieved at 0.026 V/\AA{}, this epitaxial 2D
electron system should be usable in spintronics applications.",1906.01425v2
2019-07-15,Current-driven domain wall dynamics in ferrimagnets: micromagnetic approach and collective coordinates model,"Theoretical studies dealing with current-driven domain wall dynamics in
ferrimagnetic alloys and, by extension, other antiferromagnetically coupled
systems as some multilayers, are here presented. The analysis has been made by
means of micromagnetic simulations that consider these systems as constituted
by two subsystems coupled in terms of an additional exchange interlacing them.
Both subsystems differ in their respective gyromagnetic ratios and temperature
dependence. Other interactions, as for example anisotropic exchange or
spin-orbit torques, can be accounted for differently within each subsystem
according to the physical structure. Micromagnetic simulations are also
endorsed by means of a collective coordinates model which, in contrast with
some previous approaches to these antiferromagnetically coupled systems, based
on effective parameters, also considers them as formed by two coupled
subsystems with experimentally definite parameters. Both simulations and the
collective model reinforce the angular moment compensation argument as
accountable for the linear increase with current of domain wall velocities in
these alloys at a certain temperature or composition. Importantly, the proposed
approach by means of two coupled subsystems permits to infer relevant results
in the development of future experimental setups that are unattainable by means
of effective models.",1907.06431v1
2019-10-16,"Thermal Hall effect, spin Nernst effect, and spin density induced by thermal gradient in collinear ferrimagnets from magnon-phonon interaction","We theoretically study the intrinsic thermal Hall and spin Nernst effect in
collinear ferrimagnets on a honeycomb lattice with broken inversion symmetry.
The broken inversion symmetry allows in-plane Dzyaloshinskii-Moriya interaction
between the nearest neighbors, which does not affect the magnon spectrum in the
linear spin wave theory. However, the Dzyaloshinskii-Moriya interaction can
induce large Berry curvature in the magnetoelastic excitation spectrum through
the magnon-phonon interaction to produce thermal Hall current. Furthermore, we
find that the magnetoelastic excitations transport spin, which is inherited
from the magnon bands. Therefore, the thermal Hall current is accompanied by
spin Nernst current. Because the magnon-phonon interaction does not conserve
the spin, we also study the spin density induced by thermal gradient in the
presence of magnon-phonon interaction. We find that the intrinsic part of the
spin density shows no asymmetric spin accumulation near the boundary of the
system having a stripe geometry. However, because of the magnon-phonon
interaction, we find nonzero total spin density in the system having armchair
edges. The extrinsic part of the spin density, on the other hand, shows
asymmetric spin accumulation near the boundary for both armchair and zigzag
edges because of the magnon-phonon interaction. In addition, we find nonzero
total spin density in the system having zigzag edge.",1910.07206v2
2020-01-02,Polarizing an antiferromagnet by optical engineering of the crystal field,"Strain engineering is widely used to manipulate the electronic and magnetic
properties of complex materials. An attractive route to control magnetism with
strain is provided by the piezomagnetic effect, whereby the staggered spin
structure of an antiferromagnet is decompensated by breaking the crystal field
symmetry, which induces a ferrimagnetic polarization. Piezomagnetism is
especially attractive because unlike magnetostriction it couples strain and
magnetization at linear order, and allows for bi-directional control suitable
for memory and spintronics applications. However, its use in functional devices
has so far been hindered by the slow speed and large uniaxial strains required.
Here, we show that the essential features of piezomagnetism can be reproduced
with optical phonons alone, which can be driven by light to large amplitudes
without changing the volume and hence beyond the elastic limits of the
material. We exploit nonlinear, three-phonon mixing to induce the desired
crystal field distortions in the antiferromagnet CoF$_2$. Through this effect,
we generate a ferrimagnetic moment of 0.2 $\mu_B$ per unit cell, nearly three
orders of magnitude larger than achieved with mechanical strain.",2001.00540v1
2020-04-24,Observation of magnetic domain and bubble structures in magnetoelectric Sr$_3$Co$_2$Fe$_{24}$O$_{41}$,"The magnetic domain and bubble structures in the Z-type hexaferrite
Sr$_3$Co$_2$Fe$_{24}$O$_{41}$ were investigated using Lorentz microscopy. This
hexaferrite exhibits a room-temperature magnetoelectric effect that is
attributed to its transverse conical spin structure (TC phase). Upon heating,
the TC phase transforms into a ferrimagnetic phase with magnetic moments in the
hexagonal $ab$ plane between 410 and 480 K (FM2 phase) and into another
ferrimagnetic phase with moments parallel to the $c$ axis between 490 and 680 K
(FM1 phase). Accordingly, in this study, the magnetic domain structures in
Sr$_3$Co$_2$Fe$_{24}$O$_{41}$ were observed to change dramatically with
temperature. In the TC phase, irregular fine magnetic domains were observed
after cooling the specimen from the FM2 to TC phase. In the FM1 phase, striped
magnetic domain walls with pairs of bright and dark contrast were formed
parallel to the $c$ axis. Upon applying an external magnetic field, the striped
magnetic domain walls transformed into magnetic bubbles. The topology of the
magnetic bubbles was dependent on the angle between the external magnetic field
($H$) direction and the easy $c$ axis. Namely, magnetic bubbles with the
topological number $N$ = 1 (type I) were created for $H//c$, whereas magnetic
bubbles with $N$ = 0 (type II) were created when the magnetic field was tilted
from the c axis by 5{\deg}. We attribute the high magnetocrystalline anisotropy
of Sr$_3$Co$_2$Fe$_{24}$O$_{41}$ to the emergence of magnetic bubbles in the
FM1 phase.",2004.11591v1
2020-12-04,Anomalous Hall and Nernst effects in ferrimagnetic Mn$_4$N films: possible interpretation and prospect for enhancement,"Ferrimagnetic Mn$_4$N is a promising material for heat flux sensors based on
the anomalous Nernst effect (ANE) because of its sizable uniaxial magnetic
anisotropy ($K_{\rm u}$) and low saturation magnetization ($M_{\rm s}$). We
experimentally and theoretically investigated the ANE and anomalous Hall effect
in sputter-deposited Mn$_4$N films. It was revealed that the observed negative
anomalous Hall conductivity ($\sigma_{xy}$) could be explained by two different
coexisting magnetic structures, that is, a dominant magnetic structure with
high $K_{\rm u}$ contaminated by another structure with negligible $K_{\rm u}$
owing to an imperfect degree of order of nitrogen. The observed transverse
thermoelectric power ($S_{\rm ANE}$) of $+0.5\, \mu{\rm V/K}$ at $300\, {\rm
K}$ gave a transverse thermoelectric coefficient ($\alpha_{xy}$) of $+0.34\,
{\rm A/(m \cdot K)}$, which was smaller than the value predicted from
first-principles calculation. The interpretation for $\alpha_{xy}$ based on the
first-principles calculations led us to conclude that the realization of single
magnetic structure with high $K_{\rm u}$ and optimal adjustment of the Fermi
level are promising approaches to enhance $S_{\rm ANE}$ in Mn$_4$N through the
sign reversal of $\sigma_{xy}$ and the enlargement of $\alpha_{xy}$ up to a
theoretical value of $1.77\, {\rm A/(m \cdot K)}$.",2012.02510v2
2020-12-08,"Effect of O-doping or N-vacancy on the structural, electronic and magnetic properties of MoSi2N4 monolayer","In this letter, the effect of four types of defects (ONout, ONin, VNout and
VNin) on the structural, electronic and magnetic properties of MoSi2N4
monolayer were investigated using first-principles calculations. The calculated
results reveal that all the four types of defects lead to structural
distortions around the O-dopant or N-vacancy, and thereby change the lattice
parameter and monolayer height h. Specifically, ONout or ONin increases the
lattice parameter, but VNout or VNin is on the contrary. ONout or VNout
increases the monolayer height, whereas the height decreases for ONin or VNin.
Each of the four types of defects has a fundamental effect on the electronic
properties of MoSi2N4 monolayer, which can induce a transition from
semiconductor to metal. ONin or VNin plays a vital role in the occurrence of a
transition from non-magnetism to ferrimagnetism in MoSi2N4 monolayer. The
effect of biaxial strain on the magnetic properties of the two systems with
ONin and VNin was subsequently investigated. It is found that the total
magnetic moments are less sensitive to biaxial strain whereas the local
magnetic moments residing on the Mo atoms are increased for the two systems
with ONin and VNin, as strain increases from -3% to 10% and from -9% to 10%,
respectively. Furthermore, the magnetic phase transitions between ferrimagnetic
and paramagnetic states were found to occur around -4% strain and within the
range from -10% to -9% for the two systems with ONin and VNin, respectively.
This study may provide a guidance for the application of MoSi2N4 monolayer in
the spintronic and magnetic materials.",2012.04162v1
2020-12-14,Quantum phases of a frustrated spin-1 system: The 5/7 skewed ladder,"The quantum phases in a spin-1 skewed ladder system formed by alternately
fusing five- and seven-membered rings are studied numerically using the exact
diagonalization technique up to 16 spins and using the density matrix
renormalization group method for larger system sizes. The ladder has a fixed
isotropic antiferromagnetic (AF) exchange interaction ($J_2 = 1$) between the
nearest-neighbor spins along the legs and a varying isotropic AF exchange
interaction ($J_1$) along the rungs. As a function of $J_1$, the system shows
many interesting ground states (gs) which vary from different types of
nonmagnetic and ferrimagnetic gs. The study of diverse gs properties such as
spin gap, spin-spin correlations, spin density and bond order reveal that the
system has four distinct phases, namely, the AF phase at small $J_1$; the
ferrimagnetic phase with gs spin $S_G = n$ for $1.44 < J_1 < 4.74$ and with
$S_G = 2n$ for $J_1 > 5.63$, where $n$ is the number of unit cells; and a
reentrant nonmagnetic phase at $4.74 < J_1 < 5.44$. The system also shows the
presence of spin current at specific $J_1$ values due to simultaneous breaking
of both reflection and spin parity symmetries.",2012.07486v3
2021-01-11,Current-driven domain wall dynamics in ferrimagnetic Ni-doped Mn4N films : very large domain wall velocities and reversal of motion direction across the magnetic compensation point,"Spin-transfer torque (STT) and spin-orbit torque (SOT) are spintronic
phenomena allowing magnetization manipulation using electrical currents. Beyond
their fundamental interest, they allow developing new classes of magnetic
memories and logic devices, in particular based on domain wall (DW) motion. In
this work, we report the study of STT driven DW motion in ferrimagnetic
manganese nickel nitride (Mn4-xNixN) films, in which a fine adjustment of the
Ni content allows setting the magnetic compensation at room temperature. The
reduced magnetization, combined with the large spin polarization of conduction
electrons, strongly enhances the STT so that domain wall velocities approaching
3000 m/s can be obtained for Ni compositions close to the compensation point.
In addition, a reversal of the domain wall motion direction is observed when
the magnetic compensation composition is crossed. This striking feature,
related to the change of direction of the spin polarization with respect to
that of the net magnetization, is clarified by ab initio band structure
calculations.",2101.04220v2
2021-01-21,Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with vertical composition gradient,"Current-induced spin-orbit torques (SOTs) are of interest for fast and
energy-efficient manipulation of magnetic order in spintronic devices. To be
deterministic, however, switching of perpendicularly magnetized materials by
SOT requires a mechanism for in-plane symmetry breaking. Existing methods to do
so involve the application of an in-plane bias magnetic field, or incorporation
of in-plane structural asymmetry in the device, both of which can be difficult
to implement in practical applications. Here, we reported bias-field-free SOT
switching in a single perpendicular CoTb layer with an engineered vertical
composition gradient. The vertical structural inversion asymmetry induces
strong intrinsic SOTs and a gradient-driven Dzyaloshinskii-Moriya interaction
(g-DMI), which breaks the in-plane symmetry during the switching process.
Micromagnetic simulations are in agreement with experimental results, and
elucidate the role of g-DMI in the deterministic switching. This
bias-field-free switching scheme for perpendicular ferrimagnets with g-DMI
provides a strategy for efficient and compact SOT device design.",2101.08518v1
2017-05-03,Linearly polarized GHz magnetization dynamics of spin helix modes in the ferrimagnetic insulator Cu$_{2}$OSeO$_{3}$,"Linear dichroism -- the polarization dependent absorption of electromagnetic
waves -- is routinely exploited in applications as diverse as structure
determination of DNA or polarization filters in optical technologies. Here
filamentary absorbers with a large length-to-width ratio are a prerequisite.
For magnetization dynamics in the few GHz frequency regime strictly linear
dichroism was not observed for more than eight decades. Here, we show that the
bulk chiral magnet Cu$_{2}$OSeO$_{3}$ exhibits linearly polarized magnetization
dynamics at an unexpectedly small frequency of about 2 GHz. Unlike optical
filters that are assembled from filamentary absorbers, the magnet provides
linear polarization as a bulk material for an extremely wide range of
length-to-width ratios. In addition, the polarization plane of a given mode can
be switched by 90$^\circ$ via a tiny variation in width. Our findings shed a
new light on magnetization dynamics in that ferrimagnetic ordering combined
with anisotropic exchange interaction offers strictly linear polarization and
cross-polarized modes for a broad spectrum of sample shapes. The discovery
allows for novel design rules and optimization of microwave-to-magnon
transduction in emerging microwave technologies.",1705.01582v1
2017-09-03,Femtosecond formation dynamics of the spin Seebeck effect revealed by terahertz spectroscopy,"Understanding the transfer of spin angular momentum is essential in modern
magnetism research. A model case is the generation of magnons in magnetic
insulators by heating an adjacent metal film. Here, we reveal the initial steps
of this spin Seebeck effect with <27fs time resolution using terahertz
spectroscopy on bilayers of ferrimagnetic yttrium-iron garnet and platinum.
Upon exciting the metal with an infrared laser pulse, a spin Seebeck current
$j_\textrm{s}$ arises on the same ~100fs time scale on which the metal
electrons thermalize. This observation highlights that efficient spin transfer
critically relies on carrier multiplication and is driven by conduction
electrons scattering off the metal-insulator interface. Analytical modeling
shows that the electrons' dynamics are almost instantaneously imprinted onto
$j_\textrm{s}$ because their spins have a correlation time of only ~4fs and
deflect the ferrimagnetic moments without inertia. Applications in material
characterization, interface probing, spin-noise spectroscopy and terahertz spin
pumping emerge.",1709.00768v5
2019-01-16,"Magnetic properties of double perovskite $Ln_2$CoIrO$_6$ ($Ln$ = Eu, Tb, Ho): hetero-tri-spin $3d$-$5d$-$4f$ systems","The field of double perovskites is now advancing to three magnetic elements
on the A, B and B$'$ sites. A series of iridium-based double perovskite
compounds, $Ln_2$CoIrO$_6$ ($Ln$ = Eu, Tb, Ho) with three magnetic elements
were synthesized as polycrystalline samples. The compounds crystalize in
monoclinic structures with the space group $P2_1/n$. Magnetic properties of
these hetero-tri-spin $3d$-$5d$-$4f$ systems were studied by magnetic
susceptibility and field dependent magnetization in both DC and pulsed magnetic
fields. All these compounds show ferrimagnetic transitions at temperatures
$T_C$ above 100 K, which are attributable to antiferromagnetic coupling between
Co$^{2+}$ and Ir$^{4+}$ spins. For Eu$_2$CoIrO$_6$, the magnetic properties are
similar to those of La$_2$CoIrO$_6$. The Eu$^{3+}$ spins show Van Vleck
paramagnetism that don't significantly interact with transition-metal cations.
By contrast, Tb$_2$CoIrO$_6$ and Ho$_2$CoIrO$_6$ reveal a second transition to
antiferromagnetic order below a lower temperature $T_N$. The
temperature-induced ferrimagnetic-to-antiferromagnetic phase transition might
be explained by a spin-reorientation transition. Moreover, a
magnetic-field-induced spin-flop transition with a small hysteresis was
observed below $T_N$ in these two compounds. The magnetic moment of all three
compounds do not saturate up to 60 T at low temperatures. Moderate
magnetocaloric effect was also observed in all three compounds. Our results
should motivate further investigation of the spin configuration on single
crystals of these iridium-based double perovskites.",1901.05412v1
2019-01-28,Spin Hall magnetoresistance in heterostructures consisting of noncrystalline paramagnetic YIG and Pt,"The spin Hall magnetoresistance (SMR) effect arises from spin-transfer
processes across the interface between a spin Hall active metal and an
insulating magnet. While the SMR response of ferrimagnetic and
antiferromagnetic insulators has been studied extensively, the SMR of a
paramagnetic spin ensemble is not well established. Thus, we investigate herein
the magnetoresistive response of as-deposited yttrium iron garnet/platinum thin
film bilayers as a function of the orientation and the amplitude of an
externally applied magnetic field. Structural and magnetic characterization
show no evidence for crystalline order or spontaneous magnetization in the
yttrium iron garnet layer. Nevertheless, we observe a clear magnetoresistance
response with a dependence on the magnetic field orientation characteristic for
the SMR. We propose two models for the origin of the SMR response in
paramagnetic insulator/Pt heterostructures. The first model describes the SMR
of an ensemble of non-interacting paramagnetic moments, while the second model
describes the magnetoresistance arising by considering the total net moment.
Interestingly, our experimental data are consistently described by the net
moment picture, in contrast to the situation in compensated ferrimagnets or
antiferromagnets.",1901.09986v1
2019-02-27,"Charge and Orbital Orderings, and Frustration in Quasi-one-dimensional Ferrimagnetic Insulator $β$-V$_2$O(PO$_4$)","Using ab initio calculations based on the correlated band theory, we have
investigated the quasi-one-dimensional chain system $\beta$-V$_2$O(PO$_4$),
showing both charge and spin orderings. Even in the uncorrelated region, the
pure transition from the tetragonal to the monoclinic structure leads to a
sizable charge difference between the two types of V ions, regardless of
magnetic orders. In the ferrimagnetic phase, inclusion of the on-site Coulomb
repulsion $U$ leads to a full orbital-polarization of V1 ($t_{2g}^{3\uparrow}$,
$S=\frac{3}{2}$) and V2 ($a_{1g}^{1\downarrow}e_g^{\prime{1\downarrow}}$,
$S=1$) above $U^c_{eff}\approx3.5$ eV, leading to local spin moments of 2.30
and --1.54 $\mu_B$, respectively, with small orbital moments of several
hundredth $\mu_B$. So, the net moment is nearly 1 $\mu_B$ per formula unit,
which is about 2--3 times larger than the experimental value. Our results show
significant variations, strongly depending on the strength of $U_{eff}$, in
energy differences between various magnetic states as well as a small magnetic
anisotropy. These results suggest that the substantial difference between the
calculated and experimental moments is attributed to quantum fluctuation of the
pyrochlore-like weakly linked V$_4$ tetrahedral structure. Our findings are
expected to provide a good platform to investigate the interplay among the
charge-, spin-, and lattice-degrees of freedom, and geometrical frustration.",1902.10359v1
2019-03-08,Spin-transfer torques for domain walls in antiferromagnetically coupled ferrimagnets,"Antiferromagnetic materials are outstanding candidates for next generation
spintronic applications, because their ultrafast spin dynamics makes it
possible to realize several orders of magnitude higher-speed devices than
conventional ferromagnetic materials1. Though spin-transfer torque (STT) is a
key for electrical control of spins as successfully demonstrated in
ferromagnetic spintronics, experimental understanding of STT in
antiferromagnets has been still lacking despite a number of pertinent
theoretical studies2-5. Here, we report experimental results on the effects of
STT on domain-wall (DW) motion in antiferromagnetically-coupled ferrimagnets.
We find that non-adiabatic STT acts like a staggered magnetic field and thus
can drive DWs effectively. Moreover, the non-adiabaticity parameter {\beta} of
STT is found to be significantly larger than the Gilbert damping parameter
{\alpha}, challenging our conventional understanding of the non-adiabatic STT
based on ferromagnets as well as leading to fast current-induced
antiferromagnetic DW motion. Our study will lead to further vigorous
exploration of STT for antiferromagnetic spin textures for fundamental physics
on spin-charge interaction as wells for efficient electrical control of
antiferromagnetic devices.",1903.03251v1
2019-11-25,Flat Bands and Ferrimagnetic Order in Electronically Correlated Dice-Lattice Ribbons,"We study ribbons of the dice two-dimensional lattice (that we call ``dice
ladders'') known to have nontrivial topological properties, such as Chern
numbers 2 [Wang and Y. Ran, Phys. Rev. B {\bf 84}, 241103 (2011)]. Our main
results are two folded: (1) Analyzing the tight-binding model in the presence
of Rashba spin-orbit coupling and an external magnetic field, we observed that
dice ladders qualitatively display properties similar to their two-dimensional
counterpart all the way to the limit of only two legs in the short direction.
This includes flat bands near the Fermi level, edge currents and edge charge
localization near zero energy when open boundary conditions are used, two
chiral edge modes, and a nonzero Hall conductance. (2) We studied the effect of
Hubbard correlation $U$ in the two-leg dice ladder using Lanczos and density
matrix renormalization group techniques. We show that increasing $U$ the flat
bands split without the need of introducing external fields. Moreover, robust
ferrimagnetic order develops. Overall, our work establishes dice ladders as a
promising playground to study the combined effect of topology and correlation
effects, one of the frontiers in Quantum Materials.",1911.11267v2
2020-05-08,Enhanced all-optical switching and domain wall velocity in annealed synthetic-ferrimagnetic multilayers,"All optical switching (AOS) of the magnetization in synthetic ferrimagnetic
Pt/Co/Gd stacks has received considerable interest due to its high potential
towards integration with spintronic devices, such as magnetic tunnel junctions
(MTJs), to enable ultrafast memory applications. Post-annealing is an essential
process in the MTJ fabrication to obtain optimized tunnel magnetoresistance
(TMR) ratio. However, with integrating AOS with an MTJ in prospect, the
annealing effects on single-pulse AOS and domain wall (DW) dynamics in the
Pt/Co/Gd stacks haven't been systematically investigated yet. In this study, we
experimentally explore the annealing effect on AOS and field-induced DW motion
in Pt/Co/Gd stacks. The results show that the threshold fluence (F_0) for AOS
is reduced significantly as a function of annealing temperature (T_a) ranging
from 100C to 300C. Specifically, a 28% reduction of F_0 can be observed upon
annealing at 300C, which is a critical T_a for MTJ fabrication. Lastly, we also
demonstrate a significant increase of the DW velocity in the creep regime upon
annealing, which is attributed to annealing-induced Co/Gd interface
intermixing. Our findings show that annealed Pt/Co/Gd system facilitates
ultrafast and energy-efficient AOS, as well as enhanced DW velocity, which is
highly suitable towards opto-spintronic memory applications.",2005.03971v1
2020-06-18,Current-induced in-plane magnetization switching in biaxial ferrimagnetic insulator,"Ferrimagnetic insulators (FiMI) have been intensively used in microwave and
magneto-optical devices as well as spin caloritronics, where their
magnetization direction plays a fundamental role on the device performance. The
magnetization is generally switched by applying external magnetic fields. Here
we investigate current-induced spin-orbit torque (SOT) switching of the
magnetization in Y3Fe5O12 (YIG)/Pt bilayers with in-plane magnetic anisotropy,
where the switching is detected by spin Hall magnetoresistance. Reversible
switching is found at room temperature for a threshold current density of 10^7
A cm^-2. The YIG sublattices with antiparallel and unequal magnetic moments are
aligned parallel or antiparallel to the direction of current pulses, which is
consistent to the Neel order switching in antiferromagnetic system. It is
proposed that such a switching behavior may be triggered by the
antidamping-torque acting on the two antiparallel sublattices of FiMI. Our
finding not only broadens the magnetization switching by electrical means and
promotes the understanding of magnetization switching, but also paves the way
for all-electrically modulated microwave devices and spin caloritronics with
low power consumption.",2006.10313v1
2020-08-18,Compensation and its systematics in spin-1/2 Ising trilayered triangular ferrimagnet,"Trilayered, Ising, spin-1/2, ferrimagnets are an interesting subject for
simulational studies for they show compensation effect. A Monte Carlo study on
such a system with sublayers on triangular lattice is performed in the current
work. Three layers, making up the bulk, is formed completely by either A or B
type of atoms. The interactions between like atoms (A-A; B-B) are ferromagnetic
and between unlike ones (A-B) are anti-ferromagnetic. Thus the system has three
coupling constants and manifests into two distinct trilayer compositions: AAB
and ABA. Metropolis single spin flip algorithm is employed for the simulation
and the location of the critical points (sublattice magnetisations vanish,
leading to zero bulk magnetisation) and the compensation points (bulk
magnetisation vanishes but nonzero sublattice magnetisations exist) are
estimated. Close range simulations with variable lattice sizes for compensation
point and Binder's cumulant crossing technique for critical points are employed
for analysis and conditions for the existence of compensation points are
determined. Comprehensive phase diagrams are obtained in the Hamiltonian
parameter space and morphological studies at critical and compensation
temperatures for both the configurations are also reported. The alternative
description in terms of Inverse absolute of reduced residual magnetisation and
Temperature interval between Critical and Compensation temperatures is also
proposed and compared with traditional simulational results. Such simulational
studies and the proposed systematics of compensation effect are useful in
designing materials for specific technological applications.",2008.07808v5
2020-08-28,"Unconventional strengthening of a bipartite entanglement of a mixed spin-(1/2,1) Heisenberg dimer achieved through Zeeman splitting","The bipartite quantum and thermal entanglement is quantified within pure and
mixed states of a mixed spin-(1/2,1) Heisenberg dimer with the help of
negativity. It is shown that the negativity, which may serve as a measure of
the bipartite entanglement at zero as well as nonzero temperatures, strongly
depends on intrinsic parameters as for instance exchange and uniaxial
single-ion anisotropy in addition to extrinsic parameters such as temperature
and magnetic field. It turns out that a rising magnetic field unexpectedly
reinforces the bipartite entanglement due to the Zeeman splitting of energy
levels, which lifts a two-fold degeneracy of the quantum ferrimagnetic ground
state. The maximal bipartite entanglement is thus reached within a quantum
ferrimagnetic phase at sufficiently low but nonzero magnetic fields on
assumption that the gyromagnetic g-factors of the spin-1/2 and spin-1 magnetic
ions are equal and the uniaxial single-ion anisotropy is a half of the exchange
constant. It is suggested that the heterodinuclear complex
[Ni(dpt)(H$_2$O)Cu(pba)]$\cdot$2H$_2$O (pba=1,3-propylenebis(oxamato) and
dpt=bis-(3-aminopropyl)amine), which affords an experimental realization of the
mixed spin-(1/2,1) Heisenberg dimer, remains strongly entangled up to
relatively high temperatures (about 140~K) and magnetic fields (about 140~T)
being comparable with the relevant exchange constant.",2008.12555v1
2020-09-06,Ferrimagnetism Induced by Off-Site Coulomb Interaction in an Itinerant Electron System,"Motivated by weak ferromagnetism (FM) in a $\tau$-type molecular conductor
($\tau$-MC), we examine its mechanism using a two-band extended Hubbard model.
Applying the random phase approximation, we elucidate the uniform spin and
charge fluctuations between unit cells in the presence of on-site and off-site
interactions. Applying the mean-field approximation, we find the ordered state
mixing with antiferromagnetism (AFM), weak FM, and charge ordering (CO)
components in each unit cell: we classify this state as ferrimagnetism (FIM).
We reveal the phase diagrams in the interaction and interaction-temperature
spaces. The former shows that the off-site interaction induces FIM from pure
AFM and the latter shows that lowering the temperature stabilizes FIM. To
clarify the stabilization mechanism of the phases, we focus on the microscopic
nature of the ordered states, including the band structure, Fermi surface, and
density of states. We find that the FIM state is obtained from mixing features
of AFM, CO, and FM; therefore, the emergence of FIM requires both the on-site
and off-site interactions. Then, we discuss the effect of lowering the
temperature and predict that the AFM gap assists the emergence of FIM based on
AFM. This FIM state is possibly related to the observation of the weak FM in
$\tau$-MC.",2009.02675v1
2020-10-08,Ferrimagnetic 120$^\circ$ magnetic structure in Cu2OSO4,"We report magnetic properties of a 3d$^9$ (Cu$^{2+}$) magnetic insulator
Cu2OSO4 measured on both powder and single crystal. The magnetic atoms of this
compound form layers, whose geometry can be described either as a system of
chains coupled through dimers or as a Kagom\'e lattice where every 3rd spin is
replaced by a dimer. Specific heat and DC-susceptibility show a magnetic
transition at 20 K, which is also confirmed by neutron scattering. Magnetic
entropy extracted from the specific heat data is consistent with a $S=1/2$
degree of freedom per Cu$^{2+}$, and so is the effective moment extracted from
DC-susceptibility. The ground state has been identified by means of neutron
diffraction on both powder and single crystal and corresponds to a $\sim120$
degree spin structure in which ferromagnetic intra-dimer alignment results in a
net ferrimagnetic moment. No evidence is found for a change in lattice symmetry
down to 2 K. Our results suggest that \sample \ represents a new type of model
lattice with frustrated interactions where interplay between magnetic order,
thermal and quantum fluctuations can be explored.",2010.03838v1
2020-10-13,"Loss of classicality in alternating spin-$\frac{1}{2}$/spin-$1$ chain, in the presence of next-neighbor couplings and Dzyaloshinskii-Moriya interactions","We have considered and alternating Heisenberg spin chain with
nearest-neighbor ($J_1$), next-nearest neighbor ($J_2$) antiferromagnetic
couplings along with z-component of the Dzyaloshinskii-Moriya(DM) ($D_z$)
interactions. The Hamiltonian has been studied using (a) Linear Spin-Wave
Theory(LSWT) and (b) Density Matrix Renormalization Group (DMRG). The system
had been reported earlier as a classical ferrimagnet only when nearest neighbor
exchange interactions are present. Both the antiferromagnetic next-nearest
neighbor interactions and DM interactions introduce strong quantum fluctuations
and due to which all the signatures of ferrimagnetism vanishes. We find that
the nonzero $J_2$ introduces strong quantum fluctuations in each of the spin
sites due to which the z-components of both spin-1 and spin-1/2 sites average
out to be zero. The ground state becomes a singlet. The presence of $J_1$ along
with $D_z$ introduces a short range order but develops long range order along
the XY plane. $J_1$ along with $J_2$ induces competing phases with structure
factor showing sharp and wide peaks, at two different angles reflecting the
spin spiral structure locally as well as in the underlying lattice.
Interestingly, we find that the $D_z$ term removes the local spin spiral
structure in z-direction, while developing a spiral order in the XY plane.",2010.06258v2
2020-10-29,Domain wall dynamics in antiferromagnetically-coupled double-lattice systems,"In ferromagnetic materials, the rich dynamics of magnetic domain walls (DWs)
under magnetic field or current have been successfully described using the
well-known q-{\phi} analytical model. We demonstrate here that this simple
unidimensional model holds for multiple-sublattice materials such as
ferrimagnetic alloys or synthetic antiferromagnets (SAF) by using effective
parameters, and is in excellent agreement with double-lattice micromagnetic
simulations. We obtain analytical laws for the DW velocity and internal
precession angle as a function of net magnetisation for different driving
forces (magnetic field, spin transfer and spin-orbit torques) and different
propagation regimes in ferrimagnetic alloys and SAFs. The model predicts that
several distinctive dynamical features occur near or at the magnetic and the
angular compensation points when the net magnetization or the net angular
momentum of the system vanishes, and we discuss the experimental observations
that have been reported for some of them. Using a higher degree-of-freedom
analytical model that accounts for inter-sublattice distortions, we give
analytical expressions for these distortions that agree with the micromagnetic
simulations. This model shows that the DW velocity and precession rate are
independent of the strength of the inter-sublattice exchange coupling, and
justifies the use of the simpler effective parameters model.",2010.15443v1
2020-11-03,Fully-Compensated Ferrimagnetic Spin Filter Materials within the Cr$\textit{M}\textit{N}$Al Equiatomic Quaternary Heusler Alloys,"XX'YZ equiatomic quaternary Heusler alloys (EQHA's) containing Cr, Al, and
select Group IVB elements ($\textit{M}$ = Ti, Zr, Hf) and Group VB elements
($\textit{N}$ = V, Nb, Ta) were studied using state-of-the-art density
functional theory to determine their effectiveness in spintronic applications.
Each alloy is classified based on their spin-dependent electronic structure as
a half-metal, a spin gapless semiconductor, or a spin filter material. We
predict several new fully-compensated ferrimagnetic spin filter materials with
small electronic gaps and large exchange splitting allowing for robust spin
polarization with small resistance. CrVZrAl, CrVHfAl, CrTiNbAl, and CrTiTaAl
are identified as particularly robust spin filter candidates with an exchange
splitting of $\sim 0.20$ eV. In particular, CrTiNbAl and CrTiTaAl have
exceptionally small band gaps of $\sim 0.10$ eV. Moreover, in these compounds,
a spin asymmetric electronic band gap is maintained in 2 of 3 possible atomic
arrangements they can take, making the electronic properties less susceptible
to random site disorder. In addition, hydrostatic stress is applied to a subset
of the studied compounds in order to determine the stability and tunability of
the various electronic phases. Specifically, we find the CrAlV$\textit{M}$
subfamily of compounds to be exceptionally sensitive to hydrostatic stress,
yielding transitions between all spin-dependent electronic phases.",2011.01389v1
2020-11-18,Domain Wall Motion in Magnetic Nanostrips,"Domain walls are the transition regions between two magnetic domains. These
objects have been very relevant during the last decade, not only due to their
intrinsic interest in the development of novel spintronics devices but also
because of their fundamental interest. The study of domain wall has been linked
to the research on novel spin-orbit coupling phenomena such as the
Dzyaloshinskii-Moriya interaction and the spin Hall effect amount others.
Domain walls can be nucleated in ferromagnetic nanostrips and can be driven by
conventional magnetic fields and spin currents due to the injection of
electrical pulses, which make them very promising for technological
applications of recording and logic devices. In this review, based on full
micromagnetic simulations supported by extended one-dimensional models, we
describe the static and dynamic properties of domain walls in thin
ferromagnetic and ferrimagnetic wires with perpendicular magnetic anisotropy.
The present chapter aims to provide a fundamental theoretical description of
the fundaments of domain walls, and the numerical tools and models which allow
describing the DW dynamics in previous and future experimental setups.",2011.09423v2
2021-02-17,Axion search with quantum nondemolition detection of magnons,"The axion provides a solution for the strong CP problem and is one of the
leading candidates for dark matter. This paper proposes an axion detection
scheme based on quantum nondemolition detection of magnon, i.e., quanta of
collective spin excitations in solid, which is expected to be excited by the
axion-electron interaction predicted by the Dine-Fischer-Srednicki-Zhitnitsky
(DFSZ) model. The prototype detector is composed of a ferrimagnetic sphere as
an electronic spin target and a superconducting qubit. Both of these are
embedded inside a microwave cavity, which leads to a coherent effective
interaction between the uniform magnetostatic mode in the ferrimagnetic crystal
and the qubit. An upper limit for the coupling constant between an axion and an
electron is obtained as $g_{aee}<2.6\times10^{-6}$ at the 95% confidence level
for the axion mass of $33.117$$\mu$eV $<m_{a}<33.130$$\mu$eV.",2102.08764v4
2021-07-06,Influence of magnetic domain walls on all-optical magnetic toggle switching in a ferrimagnetic GdFe film,"We present a microscopic magnetic domain imaging study of single-shot
all-optical magnetic toggle switching of a ferrimagnetic Gd$_{26}$Fe$_{74}$
film with out-of-plane easy axis of magnetization by x-ray magnetic circular
dichroism photoelectron emission microscopy. Individual linearly polarized
laser pulses of 800 nm wavelength and 100 fs duration above a certain threshold
fluence reverse the sample magnetization, independent of the magnetization
direction, the so-called toggle switching. Local deviations from this
deterministic behavior close to magnetic domain walls are studied in detail.
Reasons for nondeterministic toggle switching are related to extrinsic effects,
caused by pulse-to-pulse variations of the exciting laser system, and to
intrinsic effects related to the magnetic domain structure of the sample. The
latter are, on the one hand, caused by magnetic domain wall elasticity, which
leads to a reduction of the domain-wall length at sharp tipped features. These
features appear after the optical switching at positions where the line of
constant threshold fluence in the Gaussian footprint of the laser pulse comes
close to an already-existing domain wall. On the other hand, we identify the
presence of laser-induced domain-wall motion in the toggle-switching event as a
further cause for local deviations from purely deterministic toggle switching.",2107.02484v2
2021-08-24,Search for enhanced magnetism at the interface between Bi$_2$Se$_3$ and EuSe,"Enhanced magnetism has recently been reported for the
topological-insulator/ferromagnet interface Bi$_2$Se$_3$/EuS with Curie
temperatures claimed to be raised above room temperature from the bulk EuS
value of 16 K. Here we investigate the analogous interface Bi$_2$Se$_3$/EuSe.
EuSe is a low-temperature layered ferrimagnet that is particularly sensitive to
external perturbations. We find that superconducting quantum interference
device (SQUID) magnetometry of Bi$_2$Se$_3$/EuSe heterostructures reveals
precisely the magnetic phase diagram known from EuSe, including the
ferrimagnetic phase below 5 K, without any apparent changes from the bulk
behavior. Choosing a temperature of 10 K to search for magnetic enhancement, we
determine an upper limit for a possible magnetic coercive field of 3 mT. Using
interface sensitive x-ray absorption spectroscopy we verify the magnetic
divalent configuration of the Eu at the interface without contamination by
Eu3+, and by x-ray magnetic circular dichroism (XMCD) we confirm at the
interface the magnetic hysteresis obtained by SQUID. XMCD data obtained at 10 K
in a magnetic field of 6 T indicate a magnetic spin moment of mz,spin = 7
$\mu$B/Eu$^{2+}$, in good agreement with the SQUID data and the expected
theoretical moment of Eu2+. Subsequent XMCD measurements in zero field show,
however, that sizable remanent magnetization is absent at the interface for
temperatures down to about 10 K.",2108.10732v1
2021-10-21,Polaronic transport and thermoelectricity in Mn$_3$Si$_2$Te$_6$ single crystals,"We carried out a comprehensive study of the structural, electrical transport,
thermal and thermodynamic properties in ferrimagnetic Mn$_3$Si$_2$Te$_6$ single
crystals. Mn and Te $K$-edge X-ray absorption spectroscopy and synchrotron
powder X-ray diffraction were measured to provide information on the local
atomic environment and the average crystal structure. The dc and ac magnetic
susceptibility measurements indicate a second-order paramagnetic to
ferrimagnetic transition at $T_c$ $\sim$ 74 K, which is further confirmed by
the specific heat measurement. Mn$_3$Si$_2$Te$_6$ exhibits semiconducting
behavior along with a large negative magnetoresistance of -87\% at $T_c$ and
relatively high value of thermopower up to $\sim$ 10 mV/K at 5 K. Besides the
rapidly increasing resistivity $\rho(T)$ and thermopower $S(T)$ below 20 K, the
large discrepancy between activation energy for resistivity $E_\rho$ and
thermopower $E_S$ above 20 K indicates the polaronic transport mechanism.
Furthermore, the thermal conductivity $\kappa(T)$ of Mn$_3$Si$_2$Te$_6$ is
notably rather low, comparable to Cr$_2$Si$_2$Te$_6$, and is strongly
suppressed in magnetic field across $T_c$, indicating the presence of strong
spin-lattice coupling, also similar with Cr$_2$Si$_2$Te$_6$.",2110.10911v1
2021-10-30,Tunable Magnetic Skyrmions in Ferrimagnetic Mn$_4$N,"Thin films of ferrimagnetic Mn$_4$N are candidate materials to host magnetic
skyrmions that have demonstrated thermal stability up to 450$^\circ$C. However,
there are no experimental reports observing skyrmions in this system. Here, we
discuss the results of sputter grown 15-17~nm Mn$_4$N thin films on MgO
substrate capped with Pt$_{1-x}$Cu$_{x}$ layers. Vibrating sample magnetometry
measurement of out-of-plane hysteresis loops confirmed that magnetic properties
are insensitive to the cap layer composition. Imaging based on magnetic force
microscopy measurements observed 300 to 50~nm sized skyrmions, as the Cu
concentration was increased from $x$ = 0 to 0.9. We performed density
functional theory calculations and found that the interfacial
Dzyaloshinskii-Moriya interactions (iDMI) follow a trend: Mn$_4$N/MgO(001) $<$
Cu/Mn$_4$N(001) $<$ Pt/Mn$_4$N(001). We infer from these calculations that $x$
in Pt$_{1-x}$Cu$_{x}$ capping layer can serve as a robust tuning knob to tailor
the iDMI and control the skyrmion size. This work provides guidance to achieve
smaller N\'{e}el-type skyrmions in Mn$_4$N thin films, which is an important
step forward for building thermally stable skyrmionic devices.",2111.00258v1
2021-11-02,Scaling of the thermally induced sign inversion of longitudinal spin Seebeck effect in a compensated ferrimagnet: Role of magnetic anisotropy,"We report on a systematic investigation of the longitudinal spin Seebeck
effect (LSSE) in a GGG(Gd3Ga5O12)/GdIG(Gd3Fe5O12)/Pt film series exhibiting an
in-plane magnetic easy axis with a compensation temperature (T_Comp) that
decreases from 270 to 220 K when decreasing GdIG film thickness from 272 to 31
nm, respectively. For all the films, the LSSE signal flips its sign below
T_Comp. We demonstrate a universal scaling behavior of the temperature
dependence of LSSE signal for our GdIG films around their respective T_Comp.
Additionally, we demonstrate LSSE in a 31 nm GdIG film grown on a
lattice-mismatched GSGG (Gd3Sc2Ga3O12) substrate that exhibits an out-of-plane
magnetic easy axis at room temperature. However, this sample reveals a spin
reorientation transition where the magnetic easy axis changes its orientation
to in-plane at low temperatures. We observed a clear distinction in the LSSE
signal for the GSGG/GdIG(31 nm)/Pt heterostructure, relative to
GGG/GdIG(31nm)/Pt showing an in-plane magnetic easy axis. Our findings
underscore a strong correlation between the LSSE signal and the orientation of
magnetic easy axis in compensated ferrimagnets and opens the possibility to
tune LSSE through effective anisotropy.",2111.01379v1
2021-11-13,"First Order Transitions Between the Gapped Spin-Liquid and Ferrimagnetic Phases in (1/2,1/2,1) Mixed Diamond Chains with Bond Alternation","The ground-state phases of mixed diamond chains with bond alternation
$\delta$, and ($S, \tau^{(1)}, \tau^{(2)})=(1/2,1/2,1)$, where $S$ is the
magnitude of vertex spins, and $\tau^{(1)}$ and $\tau^{(2)}$ are those of
apical spins, are investigated. The two apical spins in each unit cell are
connected by an exchange coupling $\lambda$. The exchange couplings between the
apical spins and the vertex spins take the values $1+\delta$ and $1-\delta$
alternatingly. This model has an infinite number of local conservation laws.
For large $\lambda$ and $\delta \neq 0$, the ground state is equivalent to that
of the spin $1/2$ chain with bond alternation. Hence, the ground state is a
gapped spin liquid. This energy gap vanishes for $\delta=0$. With the decrease
of $\lambda$, the ground state undergoes a transition at $\lambda=\lambda_{\rm
c0}(\delta)$ to a series of ferrimagnetic phases with a spontaneous
magnetization $m_{\rm sp}=1/p$ per unit cell where $p$ is a positive integer.
It is found that this transition is a first order transition for $\delta\neq 0$
with a discontinuous change in $m_{\rm sp}$, while no discontinuity is found
for $\delta=0$. The critical behaviors of $m_{\rm sp}$ and $\lambda_{\rm
c0}(\delta)$ around the critical point $(\delta,\lambda) =(0, \lambda_{\rm
c0}(\delta))$ are also discussed analytically.",2111.07054v2
2021-11-20,Skyrmionics in correlated oxides,"While chiral magnets, metal-based magnetic multilayers, or Heusler compounds
have been considered as the material workhorses in the field of skyrmionics,
oxides are now emerging as promising alternatives, as they host special
correlations between the spin-orbital-charge-lattice degrees of freedom and/or
coupled ferroic order parameters. These interactions open new possibilities for
practically exploiting skyrmionics. In this article, we review the recent
advances in the observation and control of topological spin textures in various
oxide systems. We start with the discovery of skyrmions and related
quasiparticles in bulk and heterostructure ferromagnetic oxides. Next, we
emphasize the shortcomings of implementing ferromagnetic textures, which have
led to the recent explorations of ferrimagnetic and antiferromagnetic oxide
counterparts, with higher Curie temperatures, stray-field immunity, low Gilbert
damping, ultrafast magnetic dynamics, and/or absence of skyrmion deflection.
Then, we highlight the development of novel pathways to control the stability,
motion, and detection of topological textures using electric fields and
currents. Finally, we present the outstanding challenges that need to be
overcome to achieve all-electrical, nonvolatile, low-power oxide skyrmionic
devices.",2111.10562v2
2021-12-05,Variation between Antiferromagnetism and Ferrimagnetism in NiPS3 by Electron Doping,"How to electrically control magnetic properties of a magnetic material is
promising towards spintronic applications, where the investigation of carrier
doping effects on antiferromagnetic (AFM) materials remains challenging due to
their zero net magnetization. In this work, we found electron doping dependent
variation of magnetic orders of a two-dimensional (2D) AFM insulator NiPS3,
where doping concentration is tuned by intercalating various organic cations
into the van der Waals gaps of NiPS3 without introduction of defects and
impurity phases. The doped NiPS3 shows an AFM-ferrimagnetic (FIM) transition at
doping level of 0.2-0.5 electrons/cell and a FIM-AFM transition at doping level
of >= 0.6 electrons/cell. We propose that the found phenomenon is due to
competition between Stoner exchange dominated inter-chain ferromagnetic order
and super-exchange dominated inter-chain AFM order at different doping level.
Our studies provide a viable way to exploit correlation between electronic
structures and magnetic properties of 2D magnetic materials for realization of
magnetoelectric effect.",2112.02544v2
2021-12-25,Spin-wave-driven skyrmion dynamics in ferrimagnets: Effect of net angular momentum,"Searching for low-power-consuming and high-efficient methods for well
controllable driving of skyrmion motion is one of the most concerned issues for
future spintronic applications, raising high concern with an appreciated choice
of magnetic media and driving scenario. In this work, we propose a novel
scenario of spin wave driven skyrmion motion in a ferrimagnetic (FiM) lattice
with the net angular momentum {\delta}s. We investigate theoretically the
effect of both {\delta}s and the circular polarization of spin wave on the
skyrmion dynamics. It is revealed that the momentum onto the skyrmion imposed
by the excited spin wave can be partitioned into a ferromagnetic term plus an
antiferromagnetic term. The ratio of these two terms and consequently the Hall
angle of skyrmion motion can be formulated as the functions of {\delta}s,
demonstrating the key role of {\delta}s as an effective control-parameter for
the skyrmion motion. Moreover, the spin wave frequency dependent skyrmion
motion is discussed, predicting the frequency enhanced skyrmion Hall motion.
This work thus represents an essential contribution to understand the skyrmion
dynamics in a FiM lattice.",2112.13232v2
2022-01-03,Handedness-filter and Doppler shift of spin waves in ferrimagnetic domain walls,"Excitation and propagation of spin waves inside magnetic domain walls has
received attention because of their potentials in spintronic and communication
applications. Besides wave amplitude and frequency, spin-wave has its third
character: handedness, whose manipulation is certainly of interest. We propose
in this Letter that the handedness of low energy spin-wave excitations can be
controlled by tuning the net angular momentum {\delta}s in a ferrimagnetic
(FiM) domain wall, attributing to the inequivalent magnetic sublattices. The
results indicate that the spin-wave dispersion depends on both {\delta}s and
wave handedness. For a positive (negative) {\delta}s, a gapless dispersion is
observed for the left-handed (righ-handed) spin waves, while a frequency gap
appears for the right-handed (left-handed) spin waves. Thus a FiM wall could
serve as a multifold filter of low energy spin-wave in which only spin waves
with particular handedness can propagate. Furthermore, the energy consumption
loss for spin-wave excitation in the wall is much lower than that inside the
domain, while the group velocity is much faster too, demonstrating the
advantages of domain walls serving as spin waveguides. Moreover, the
current-induced spin-wave Doppler shift in the FiM wall is also revealed, and
can be controlled by {\delta}s. This work unveils for the first time the
interesting spin-wave dynamics in FiM domain walls, benefiting future spin-wave
applications.",2201.00623v2
2022-01-07,First-principles study on phase stability and physical properties of B-site ordered Nd$_{2}$FeCrO$_{6}$ double perovskite,"Here, the first-principles predictions on the structural stability, magnetic
behavior and electronic structure of B-site ordered double perovskite
Nd$_{2}$FeCrO$_{6}$ have been reported. Initially, the ground state of the
parent single perovskites NdCrO$_{3}$ and NdFeO$_{3}$ have been studied to
determine the relevant Hubbard U parameter to investigate the properties of
Nd2CrFeO6. The thermodynamic, mechanical, and dynamic stability analyses
suggest the possibility of the synthesis of Nd$_{2}$FeCrO$_{6}$ double
perovskite at ambient pressure. The compound shows ferrimagnetic (FiM) nature
with 2 $\mu$B net magnetic moments and the magnetic ordering temperature has
been estimated to be $\sim$265 K. Electronic structure indicates higher
probability of direct photon transition over the indirect transition with a
bandgap of $\sim$1.85 eV. Additional effect of Nd (4f) spin and spin-orbit
coupling (SOC) on the band edges have been found to be negligible for this
4f-3d-3d spin system. This first-principles investigation predicts that due to
the ferrimagnetic nature and significantly lower bandgap compared to its
antiferromagnetic parent single perovskites, B-site ordered Nd$_{2}$FeCrO$_{6}$
double perovskite could be a promising material for spintronic and
visible-light-driven energy applications.",2201.02341v1
2022-03-31,Anomalous Hall Effect and Perpendicular Magnetic Anisotropy in Ultrathin Ferrimagnetic NiCo$_2$O$_4$ Films,"The inverse spinel ferrimagnetic NiCo$_2$O$_4$ possesses high magnetic Curie
temperature $T_C$, high spin polarization, and strain-tunable magnetic
anisotropy. Understanding the thickness scaling limit of these intriguing
magnetic properties in NiCo$_2$O$_4$ thin films is critical for their
implementation in nanoscale spintronic applications. In this work, we report
the unconventional magnetotransport properties of epitaxial (001) NiCo$_2$O$_4$
films on MgAl$_2$O$_4$ substrates in the ultrathin limit. Anomalous Hall effect
measurements reveal strong perpendicular magnetic anisotropy for films down to
1.5 unit cell (1.2 nm), while $T_C$ for 3 unit cell and thicker films remains
above 300 K. The sign change in the anomalous Hall conductivity ($\sigma_{xy}$)
and its scaling relation with the longitudinal conductivity ($\sigma_{xx}$) can
be attributed to the competing effects between impurity scattering and band
intrinsic Berry curvature, with the latter vanishing upon the thickness driven
metal-insulator transition. Our study reveals the critical role of film
thickness in tuning the relative strength of charge correlation, Berry phase
effect, spin orbit interaction, and impurity scattering, providing important
material information for designing scalable epitaxial magnetic tunnel junctions
and sensing devices using NiCo$_2$O$_4$.",2204.00133v2
2022-04-26,A puzzling insensitivity of magnon spin diffusion to the presence of 180$^\circ$ domain walls in a ferrimagnetic insulator,"We present room-temperature measurements of magnon spin diffusion in
epitaxial ferrimagnetic insulator MgAl$_{0.5}$Fe$_{1.5}$O$_{4}$ (MAFO) thin
films near zero applied magnetic field where the sample forms a multi-domain
state. Due to a weak uniaxial magnetic anisotropy, the domains are separated
primarily by 180$^\circ$ domain walls. We find, surprisingly, that the presence
of the domain walls has very little effect on the spin diffusion -- nonlocal
spin transport signals in the multi-domain state retain at least 95% of the
maximum signal strength measured for the spatially-uniform magnetic state, over
distances at least five times the typical domain size. This result is in
conflict with simple models of interactions between magnons and static domain
walls, which predict that the spin polarization carried by the magnons reverses
upon passage through a 180$^\circ$ domain wall.",2204.12377v1
2022-06-21,Laser induced ultrafast Gd 4f spin dynamics in Co100-xGdx alloys by means of time-resolved XMCD,"We have studied the laser induced ultrafast quenching of Gd 4f magnetic order
in ferrimagnetic Co100-xGdx alloys to highlight the role of the inter-atomic
exchange coupling. We have taken advantage of the ultrashort soft X-ray pulses
deliver by the femtoslicing beamline at the BESSY II synchrotron radiation
source at the Helmholtz-Zentrum Berlin to perform element- and time-resolved
X-ray Magnetic Circular Dichroism spectroscopy.Our results show that the laser
induced quenching of Gd 4f magnetic order occurs on very different time-scales
for the Co72Gd28, the Co77Gd23 and the Co79Gd21 alloys. Most of the magnetic
moment losses occur within the first picosecond (ps) while the electron
distribution is strongly out of equilibrium. After the equilibration of the
electrons and lattice temperatures (t > 1 ps), the magnetic losses occur on
slower rates that depend on the alloy composition: increasing the Co
composition speeds up the demagnetization of Gd 4f sublattice. The strength of
the inter-atomic exchange coupling which depends on composition, determines the
efficiency of the angular momentum flow from the Gd 4f spin towards the
lattice. Our results are in qualitative agreements with the predictions of the
microscopic three temperatures model for ferrimagnetic alloys.",2206.10422v1
2022-06-22,Probing Laser-Induced Spin-Current Generation in Synthetic Ferrimagnets Using Spin Waves,"Several rare-earth transition-metal ferrimagnetic systems exhibit all-optical
magnetization switching upon excitation with a femtosecond laser pulse.
Although this phenomenon is very promising for future opto-magnetic data
storage applications, the role of non-local spin transport in these systems is
scarcely understood. Using Co/Gd and Co/Tb bilayers we isolate the contribution
of the rare-earth materials to the generated spin currents by using the
precessional dynamics they excite in an adjacent ferromagnetic layer as a
probe. By measuring THz standing spin-waves as well as GHz homogeneous
precessional modes, we probe both the high- and low-frequency components of
these spin currents. The low-frequency homogeneous mode indicates a significant
contribution of Gd to the spin current, but not from Tb, consistent with the
difficulty in achieving all-optical switching in Tb-containing systems.
Measurements on the THz frequency spin waves reveal the inability of the
rare-earth generated spin currents to excite dynamics at the sub-ps timescale.
We present modelling efforts using the $s$-$d$ model, which effectively
reproduce our results and allow us to explain the behavior in terms of the
temporal profile of the spin current.",2206.10934v1
2022-06-27,Thermal spin current generation in the multifunctional ferrimagnet Ga$_{0.6}$Fe$_{1.4}$O$_{3}$,"In recent years, multifunctional materials have attracted increasing interest
for magnetic memories and energy harvesting applications. Magnetic insulating
materials are of special interest for this purpose, since they allow the design
of more efficient devices due to the lower Joule heat losses. In this context,
Ga$_{0.6}$Fe$_{1.4}$O$_3$ (GFO) is a good candidate for spintronics
applications, since it can exhibit multiferroicity and presents a spin Hall
magnetoresistance similar to the one observed in a yttrium iron garnet (YIG)/Pt
bilayer. Here, we explore GFO utilizing thermo-spin measurements in an on-chip
approach. By carefully considering the geometry of our thermo-spin devices we
are able to quantify the spin Seebeck effect and the spin current generation in
a GFO/Pt bilayer, obtaining a value comparable to that of YIG/Pt. This further
confirms the promises of an efficient spin current generation with the
possibility of an electric-field manipulation of the magnetic properties of the
system in an insulating ferrimagnetic material.",2206.13426v2
2022-07-15,Enhancing All-Optical Switching of Magnetization by He Ion Irradiation,"All-optical switching (AOS) of magnetization by a single femtosecond laser
pulse in Co/Gd based synthetic ferrimagnets is the fastest magnetization
switching process. On the other hand, He ion irradiation has become a promising
tool for interface engineering of spintronic material platforms, giving rise to
significant modification of magnetic properties. In this paper, we explore the
use of He ion irradiation to enhance single pulse AOS of Co/Gd bilayer-based
synthetic ferrimagnets. The intermixing of the constituent magnetic layers by
He ion irradiation was both numerically simulated and experimentally verified.
We theoretically modelled the effects of intermixing on AOS using the layered
microscopic 3-temperature model and found that AOS is enhanced significantly by
breaking the pristine Co/Gd interface through intermixing. Following this
notion, we studied the threshold fluence of AOS as a function of He ion
irradiation fluence. We found that the AOS threshold fluence can be reduced by
almost 30%. Our study reveals the control of AOS by He ion irradiation, which
opens up an industrially compatible approach for local AOS engineering.",2207.07766v1
2022-07-17,Quantum spin spiral ground state of the ferrimagnetic sawtooth chain,"The ferrimagnetic phase of the sawtooth chain with mixed ferromagnetic
nearest-neighbour interactions $J$ and antiferromagnetic next-nearest-neighbour
interactions $J'$ (within the isotropic Heisenberg model) was previously
characterized as a phase with commensurate order. In this paper, we demonstrate
that the system in fact exhibits an incommensurate quantum spin spiral. Even
though the ground state is translationally invariant in terms of the local spin
expectations $\avg{\vec{S}_i}$, the spiral can be detected via the connected
spin-spin correlations
$\avg{\vec{S}_i\cdot\vec{S}_j}-\avg{\vec{S}_i}\cdot\avg{\vec{S}_j}$ between the
apical spins. It has a long wavelength that grows with $J'$ and that soon
exceeds finite-system sizes typically employed in numerical simulations. A
faithful treatment thus requires the use of state-of-the-art simulations for
large, periodic systems.
  In this work, we are able to accurately treat up to $L=400$ sites (200 unit
cells) with periodic boundary conditions using the density-matrix
renormaliztion group (DMRG). Exploiting the SU(2) symmetry allows us to
directly compute the lowest-energy state for a given total spin. Our results
are corroborated by variational uniform matrix product state (VUMPS)
calculations, which work directly in the thermodynamic limit at the cost of a
lower accuracy.",2207.08273v2
2022-07-25,Insight into ground-state spin arrangement and bipartite entanglement of the polymeric coordination compound [Dy$_2$Cu$_2$]$_n$ through the symmetric spin-1/2 Ising-Heisenberg orthogonal-dimer chain,"The ground-state spin arrangement and the bipartite entanglement within
Cu$^{2+}$-Cu$^{2+}$ dimers across the magnetization process of the 4f-3d
heterometallic coordination polymer
[{Dy(hfac)$_2$(CH$_3$OH)}$_2${Cu(dmg)(Hdmg)}$_2$]$_n$ (H$_2$dmg =
dimethylglyoxime, Hhfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) are
theoretically examined using the symmetric isotropic spin-$1/2$
Ising-Heisenberg orthogonal-dimer chain. The numerical results point to five
possible ground states of the compound with three different degrees of the
quantum entanglement within Cu$^{2+}$-Cu$^{2+}$. Besides the standard
ferrimagnetic and saturated phases without quantum entanglement of Cu$^{2+}$
ions, which are manifested in low-temperature magnetization curve as wide
plateaus at the non-saturated magnetization $16.26\mu_{\rm B}$ and at the
saturation value $20.82\mu_{\rm B}$, respectively, one also finds an intriguing
singlet-like phase with just partial entanglement within Cu$^{2+}$-Cu$^{2+}$
and two singlet phases with fully entangled Cu$^{2+}$-Cu$^{2+}$ dimers. The
former quantum phase can be identified in the low-temperature magnetization
process as very narrow intermediate plateau at the magnetization $9.27\mu_{\rm
B}$ per unit cell, while the latter ones as zero magnetization plateau and
intermediate plateau at the magnetization $18.54\mu_{\rm B}$. Non-monotonous
temperature variations of the concurrence, through which the entanglement
within cooper dimers is quantified, point to the possible temporary thermal
activation of the entangled states of Cu$^{2+}$-Cu$^{2+}$ also above
non-entangled ferrimagnetic and saturated phases.",2207.11943v1
2022-08-04,Interfacial Mixing Effect in a Promising Skyrmionic Material: Ferrimagnetic Mn$_4$N,"Interfacial mixing of elements is a well-known phenomenon found in thin film
deposition. For thin-film magnetic heterostructures, interfacial compositional
inhomogeneities can have drastic effects on the resulting functionalities. As
such, care must be taken to characterize the compositional and magnetic
properties of thin films intended for device use. Recently, ferrimagnetic
Mn$_4$N thin films have drawn considerable interest due to exhibiting
perpendicular magnetic anisotropy, high domain-wall mobility, and good thermal
stability. In this study, we employed X-ray photoelectron spectroscopy (XPS)
and polarized neutron reflectometry (PNR) measurements to investigate the
interfaces of an epitaxially-grown MgO/Mn$_4$N/Pt trilayer deposited at 450
$^{\circ}$C. XPS revealed the thickness of elemental mixing regions of near 5
nm at both interfaces. Using PNR, we found that these interfaces exhibit
essentially zero net magnetization at room temperature. Despite the
high-temperature deposition at 450 $^{\circ}$C, the thickness of mixing regions
is comparable to those observed in magnetic films deposited at room
temperature. Micromagnetic simulations show that this interfacial mixing should
not deter the robust formation of small skyrmions, consistent with a recent
experiment. The results obtained are encouraging in terms of the potential of
integrating thermally stable Mn$_4$N into future spintronic devices.",2208.02681v1
2022-08-19,Tuning the Magnetic Properties of the CrMnFeCoNi Cantor Alloy,"Magnetic properties of more than twenty Cantor alloy samples of varying
composition were investigated over a temperature range of 5 K to 300 K and in
fields of up to 70 kOe using magnetometry and muon spin relaxation. Two
transitions are identified: a spin-glass-like transition that appears between
55 K and 190 K depending on composition, and a ferrimagnetic transition that
occurs at approximately 43 K in multiple samples with widely varying
compositions. The magnetic signatures at 43 K are remarkably insensitive to
chemical composition. A modified Curie-Weiss model was used to fit the
susceptibility data and to extract the net effective magnetic moment for each
sample. The resulting values for the net effective moment were either
diminished with increasing Cr or Mn concentrations or enhanced with decreasing
Fe, Co, or Ni concentrations. Beyond a sufficiently large effective moment, the
magnetic ground state transitions from ferrimagnetism to ferromagnetism. The
effective magnetic moments, together with the corresponding compositions, are
used in a global linear regression analysis to extract element-specific
effective magnetic moments, which are compared to the values obtained by
ab-initio based density functional theory (DFT) calculations. These moments
provide the information necessary to controllably tune the magnetic properties
of Cantor alloy variants.",2208.09537v1
2022-09-18,Control of chiral orbital currents in a colossal magnetoresistance material,"Colossal magnetoresistance (CMR) is an extraordinary enhancement of the
electric conductivity in the presence of a magnetic field. It is conventionally
associated with a field-induced spin polarization, which drastically reduces
spin scattering and thus electric resistance. However, ferrimagnetic Mn3Si2Te6
is an intriguing exception to this rule: it exhibits a 7-order-of-magnitude
reduction in ab-plane resistivity with a 13-Tesla anisotropy field which occur
only when a magnetic polarization is avoided [1]. Here we report an exotic
quantum state that is driven by ab-plane chiral orbital currents (COC) flowing
along edges of MnTe6 octahedra. The c-axis orbital moments of ab-plane COC
couple to the ferrimagnetic Mn spins to drastically increase the ab-plane
conductivity (CMR) when an external magnetic field is aligned along the
magnetic hard c-axis. Both the COC state and its CMR are extraordinarily
susceptible to small DC currents exceeding a critical threshold, and a hallmark
of this COC state is an exotic time-dependent, bistable switching mimicking a
first-order melting transition. The control of the COC-enabled CMR and bistable
switching offers a fundamentally new paradigm for quantum technologies.",2209.08672v1
2022-09-27,Magnetic Structure and Spin Fluctuations in Colossal Magnetoresistance Ferrimagnet Mn3Si2Te6,"The ferrimagnetic insulator Mn3Si2Te6, which features a Curie temperature Tc
at 78 K and a delicate yet consequential magnetic frustration, exhibits
colossal magnetoresistance (CMR) when the magnetic field is applied along the
magnetic hard axis, surprisingly inconsistent with existing precedents [Y. Ni,
H. Zhao, Y. Zhang et al. Phys. Rev. B 103, L161105 (2021)]. This discovery
motivates a thorough single-crystal neutron diffraction study in order to gain
insights into the magnetic structure and its hidden correlation with the new
type of CMR. Here we report a noncollinear magnetic structure below the Tc
where the moments lie predominantly within the basal plane but tilt toward the
c axis by ~10o at ambient conditions. A substantial magnetic diffuse scattering
decays slowly and persists well above the Tc. The evolution of the spin
correlation lengths agrees well with the electrical resistivity, underscoring
the role of spin fluctuation contributing to the magnetoresistivity near the
transition. Application of magnetic field along the c axis, renders a swift
occurrence of CMR but only a slow tilting of the magnetic moments toward the c
axis. The unparalleled changes indicate a non-consequential role of magnetic
polarization.",2209.13664v2
2022-09-30,Design of an integrated hybrid plasmonic-photonic device for all-optical switching and reading of spintronic memory,"We introduce a novel integrated hybrid plasmonic-photonic device for
all-optical switching and reading of nanoscale ferrimagnet bits. The racetrack
memory made of synthetic ferrimagnetic material with a perpendicular magnetic
anisotropy is coupled on to a photonic waveguide onto the indium phosphide
membrane on silicon platform. The device which is composed of a double V-shaped
gold plasmonic nanoantenna coupled with a photonic crystal cavity can enable
switching and reading of the magnetization state in nanoscale magnetic bits by
enhancing the absorbed energy density and polar magneto-optical Kerr effect
(PMOKE) locally beyond the diffraction limit. Using a three-dimensional
finite-difference time-domain method, we numerically show that our device can
switch and read the magnetization state in targeted bits down to ~100 nm in the
presence of oppositely magnetized background regions in the racetrack with
widths of 30 to 120 nm, clearly outperforming a bare photonic waveguide. Our
hybrid device tackles the challenges of nonlinear absorption in the waveguide,
weak PMOKE, and size mismatch between spintronics and integrated photonics.
Thus, it provides missing link between the integrated photonics and nanoscale
spintronics, expediting the development of ultrafast and energy efficient
advanced on-chip applications.",2209.15556v1
2022-10-27,Phases of the spin-1/2 Heisenberg antiferromagnet on the diamond-decorated square lattice in a magnetic field,"The spin-1/2 Heisenberg antiferromagnet on the frustrated diamond-decorated
square lattice is known to feature various zero-field ground-state phases,
consisting of extended monomer-dimer and dimer-tetramer ground states as well
as a ferrimagnetic regime. Using a combination of analytical arguments, density
matrix renormalization group (DMRG), exact diagonalization, as well as
sign-problem-free quantum Monte Carlo (QMC) calculations, we investigate the
properties of this system and the related Lieb lattice in the presence of a
finite magnetic field, addressing both the ground-state phase diagram as well
as several thermodynamic properties. In addition to the zero-field ground
states, we find at high magnetic field a spin-canted phase with a continuously
rising magnetization for increasing magnetic field strength, as well as the
fully polarized paramagnetic phase. At intermediate field strength, we identify
a first-order quantum phase transition line between the ferrimagnetic and the
monomer-dimer regime. This first-order line extends to finite temperatures,
terminating in a line of critical points that belong to the universality class
of the two-dimensional Ising model.",2210.15330v2
2022-12-02,FeRhCrSi: A new spin semimetal with room temperature spin-valve behavior,"Spin semimetals are a recently discovered new class of spintronic materials,
which exhibit a band gap in one spin channel while a semimetallic feature in
the other and thus allows for tunable spin transport. Here, we present
experimental verification of spin semimetallic behavior in FeRhCrSi, a
quaternary Heusler alloy with saturation moment 2 $\mu_B$ and Curie temperature
$>$ 400 K. It crystallises in the L2$_1$ structure with 50$\%$ antisite
disorder between Fe and Rh. Below 300 K, it shows a weakly temperature
dependent electrical resistivity with negative temperature coefficient,
indicating the normal semimetal or spin semimetal behavior. Anomalous
magnetoresistance data reveals dominant contribution from asymmetric part, a
clear signature of spin-valve nature, which is retained even at room
temperature. \textcolor{black}{The asymmetric part of magneto-resistance shows
an unusual increase with increasing temperature.} Hall measurements confirm the
anomalous nature of conductivity originating from the intrinsic Berry
curvature, with holes being the majority carriers. Ab-initio simulation
confirms a unique long-range ferrimagnetic ordering to be the ground state,
explaining the origin behind the unexpected low saturation moment. The
ferrimagnetic disordered structure confirms the spin semimetallic feature of
FeRhCrSi, as observed experimentally.",2212.00924v2
2023-02-05,Origin of magnetically dead layers in spinel ferrites $M\text{Fe}_2\text{O}_4$ grown on $\text{Al}_2\text{O}_3$: Effects of post-deposition annealing studied by XMCD,"We study the electronic and magnetic states of as-grown and annealed
$M\text{Fe}_2\text{O}_4$(111)/$\text{Al}_2\text{O}_3$(111) ($M=\text{Co, Ni}$)
thin films with various thicknesses grown on Si(111) substrates with the
$\gamma$-$\text{Al}_2\text{O}_3$(111) buffer layers by using x-ray absorption
spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD), to investigate
magnetically dead layers in these films. Although the magnetically dead layers
in the as-grown samples are formed near the interface with the
$\text{Al}_2\text{O}_3$ buffer layer, we reveal that ferrimagnetic order is
partially recovered by post-deposition annealing at 973 K for 48 hours in air.
By analyzing the line shapes of the XAS and XMCD spectra, we conclude that, in
the dead layers, there are a significant number of vacancies at the $T_d$ sites
of the spinel structure, which may be the microscopic origin of the degraded
ferrimagnetic order in the $M\text{Fe}_2\text{O}_4$(111) thin films.",2302.02322v1
2023-04-18,Anomalous impact of thermal fluctuations on spintransfer torque induced ferrimagnetic switching,"The dynamics of a spin torque driven ferrimagnetic (FiM) system is
investigated using the two-sublattice macrospin model. We demonstrate an
ultrafast switching in the picosecond range. However, we find that the
excessive current leads to the magnetic oscillation. Therefore, faster
switching cannot be achieved by unlimitedly increasing the current. By
systematically studying the impact of thermal fluctuations, we find the
dynamics of FiMs can also be distinguished into the precessional region, the
thermally activated region, and the cross-over region. However, in the
precessional region, there is a significant deviation between FiM and
ferromagnet (FM), i.e., the FM is insensitive to thermal fluctuations since its
switching is only determined by the amount of net charge. In contrast, we find
that the thermal effect is pronounced even a very short current pulse is
applied to the FiM. We attribute this anomalous effect to the complex relation
between the anisotropy and overdrive current. By controlling the magnetic
anisotropy, we demonstrate that the FiM can also be configured to be
insensitive to thermal fluctuations. This controllable thermal property makes
the FiM promising in many emerging applications such as the implementation of
tunable activation functions in the neuromorphic computing.",2304.08765v1
2023-04-24,Magnetism and metal-insulator transitions in the anisotropic kagome lattice,"The interest in the physical properties of kagome lattices has risen
considerably. In addition to the synthesis of new materials, the possibility of
realizing ultracold atoms on an optical kagome lattice (KL) raises interesting
issues. For instance, by considering the Hubbard model on an anisotropic KL,
with a hopping $t^\prime$ along one of the directions, one is able to
interpolate between the Lieb lattice ($t^\prime=0$) and the isotropic KL
($t^\prime=t$). The ground state of the former is a ferrimagnetic insulator for
any on-site repulsion, $U$, while the latter displays a transition between a
paramagnetic metal and a Mott insulator. One may thus consider $t^\prime$ as a
parameter controlling the degree of magnetic frustration in the system. By
means of extensive quantum Monte Carlo simulations, we have examined magnetic
and transport properties as $t^\prime$ varies between these limits in order to
set up a phase diagram in the $(U/t, t^\prime/t)$ parameter space. As an
auxiliary response, analysis of the average sign of the fermionic determinant
provides consistent predictions for critical points in the phase diagram. We
observe a metal-insulator transition occurring at some critical point
$U_c^\text{M}(t^\prime)$, which increases monotonically with $ t^\prime $, from
the unfrustrated lattice limit. In addition, we have found that the boundary
between the ferrimagnetic insulator and the Mott insulator rises sharply with
$t^\prime$.",2304.12476v1
2023-05-30,Aging and passivation of magnetic properties in Co/Gd bilayers,"Synthetic ferrimagnets based on Co and Gd bear promise for directly bridging
the gap between volatile information in the photonic domain and non-volatile
information in the magnetic domain, without the need for any intermediary
electronic conversion. Specifically, these systems exhibit strong spin-orbit
torque effects, fast domain wall motion and single-pulse all-optical switching
of the magnetization. An important open challenge to bring these materials to
the brink of applications is to achieve long-term stability of their magnetic
properties. In this work, we address the time-evolution of the magnetic moment
and compensation temperature of magnetron sputter grown Pt/Co/Gd trilayers with
various capping layers. Over the course of three months, the net magnetic
moment and compensation temperature change significantly, which we attribute to
quenching of the Gd magnetization. We identify that intermixing of the capping
layer and Gd is primarily responsible for this effect, which can be alleviated
by choosing nitrides for capping as long as reduction of nitride to oxide is
properly addressed. In short, this work provides an overview of the relevant
aging effects that should be taken into account when designing synthetic
ferrimagnets based on Co and Gd for spintronic applications.",2305.18984v1
2023-05-30,Driving skyrmions in flow regime in synthetic ferrimagnets,"Despite significant advances in the last decade regarding the room
temperature stabilization of skyrmions or their current induced dynamics, the
impact of local material inhomogeneities still remains an important issue that
impedes to reach the regime of steady state motion of these spin textures.
Here, we study the spin-torque driven motion of skyrmions in synthetic
ferrimagnetic multilayers with the aim of achieving high mobility and reduced
skyrmion Hall effect. We consider Pt|Co|Tb multilayers of various thicknesses
with antiferromagnetic coupling between the Co and Tb magnetization. The
increase of Tb thickness in the multilayers allows to reduce the total magnetic
moment and increases the spin-orbit torques allowing to reach velocities up to
400 m.s-1 for skyrmions with diameters of about 160 nm. We demonstrate that due
to reduced skyrmion Hall effect, combined with the edge repulsion of the
magnetic track making the skyrmions moving along the track without any
transverse deflection. Further, by comparing the field-induced domain wall
motion and current-induced skyrmion motion, we demonstrate that the skyrmions
at the largest current densities present all the characteristics of a dynamical
flow regime.",2305.19208v2
2023-06-30,3D oxygen vacancy order and defect-property relations in multiferroic (LuFeO$_3$)$_9$/(LuFe$_2$O$_4$)$_1$ superlattices,"Oxide heterostructures exhibit a vast variety of unique physical properties.
Examples are unconventional superconductivity in layered nickelates and
topological polar order in (PbTiO$_3$)$_n$/(SrTiO$_3$)$_n$ superlattices.
Although it is clear that variations in oxygen content are crucial for the
electronic correlation phenomena in oxides, it remains a major challenge to
quantify their impact. Here, we measure the chemical composition in
multiferroic (LuFeO$_3$)$_9$/(LuFe$_2$O$_4$)$_1$ superlattices, revealing a
one-to-one correlation between the distribution of oxygen vacancies and the
electric and magnetic properties. Using atom probe tomography, we observe
oxygen vacancies arranging in a layered three-dimensional structure with a
local density on the order of 10$^{14}$ cm$^{-2}$, congruent with the
formula-unit-thick ferrimagnetic LuFe$_2$O$_4$ layers. The vacancy order is
promoted by the locally reduced formation energy and plays a key role in
stabilizing the ferroelectric domains and ferrimagnetism in the LuFeO$_3$ and
LuFe$_2$O$_4$ layers, respectively. The results demonstrate the importance of
oxygen vacancies for the room-temperature multiferroicity in this system and
establish an approach for quantifying the oxygen defects with atomic-scale
precision in 3D, giving new opportunities for deterministic defect-enabled
property control in oxide heterostructures.",2307.00139v1
2023-07-12,Quasi-static magnetization dynamics in a compensated ferrimagnetic half-metal -- Mn$_2$Ru$_x$Ga,"Exploring anisotropy and diverse magnetization dynamics in specimens with
vanishing magnetic moments presents a significant challenge using traditional
magnetometry, as the low resolution of existing techniques hinders the ability
to obtain accurate results. In this study, we delve deeper into the examination
of magnetic anisotropy and quasi-static magnetization dynamics in \mrg\,(MRG)
thin films, as an example of a compensated ferrimagnetic half-metal, by
employing anomalous Hall effect measurements within a tetragonal crystal
lattice system. Our research proposes an innovative approach to accurately
determine the complete set of anisotropy constants of these MRG thin films. To
achieve this, we perform anomalous Hall voltage curve fitting, using torque
models under the macrospin approximation, which allow us to obtain out-of-plane
anisotropy constants $K_1=4.0\times10^4$ J m$^{-3}$ ($K_1/M=0.655$\,T) and
$K_2=2.54\times10^4$ J m$^{-3}$ ($K_2/M=0.416$\,T), along with a weaker
in-plane anisotropy constant $K_3=3.48\times10^3$ J m$^{-3}$
($K_3/M=0.057$\,T). By additionally employing first-order reversal curves
(FORC) and classical Preisach hysteresis (hysterons) models, we are able to
validate the efficacy of the macrospin model in capturing the magnetic behavior
of MRG thin films. Furthermore, our investigation substantiates that the
complex quasi-static magnetization dynamics of MRG thin films can be
effectively modelled using a combination of hysteronic and torque models. This
approach facilitates the exploration of both linear and non-linear quasi-static
magnetization dynamics, in the presence of external magnetic field and/or
current-induced effective fields, generated by the spin-orbit torque and spin
transfer torque mechanisms.",2307.06403v1
2023-07-31,Ballistic spin-transport properties of magnetic tunnel junctions with MnCr-based ferrimagnetic quaternary Heusler alloys,"We investigate the suitability of nearly half-metallic ferrimagnetic
quaternary Heusler alloys, CoCrMnZ (Z=Al, Ga, Si, Ge) to assess the feasibility
as electrode materials of MgO-based magnetic tunnel junctions (MTJ). Low
magnetic moments of these alloys originated from the anti-ferromagnetic
coupling between Mn and Cr spins ensure a negligible stray field in spintronics
devices as well as a lower switching current required to flip their spin
direction. We confirmed mechanical stability of these materials from the
evaluated values of elastic constants, and the absence of any imaginary
frequency in their phonon dispersion curves. The influence of swapping
disorders on the electronic structures and their relative stability are also
discussed. A high spin polarization of the conduction electrons are observed in
case of CoCrMnZ/MgO hetrojunctions, independent of terminations at the
interface. Based on our ballistic transport calculations, a large coherent
tunnelling of the majority-spin $s$-like $\Delta_1$ states can be expected
through MgO-barrier. The calculated tunnelling magnetoresistance (TMR) ratios
are in the order of 1000\%. A very high Curie temperatures specifically for
CoCrMnAl and CoCrMnGa, which are comparable to $bcc$ Co, could also yield a
weaker temperature dependece of TMR ratios for CoCrMnAl/MgO/CoCrMnAl (001) and
CoCrMnGa/MgO/CoCrMnGa (001) MTJ.",2307.16442v1
2023-11-09,Optically Induced Ferromagnetic Order in a Ferrimagnet,"The parallel or antiparallel arrangement of electron spins plays a pivotal
role in determining the properties of a physical system. To meet the demands
for innovative technological solutions, extensive efforts have been dedicated
to exploring effective methods for controlling and manipulating this
arrangement [1]. Among various techniques, ultrashort laser pulses have emerged
as an exceptionally efficient tool to influence magnetic order. Ultrafast
suppression of the magnetic order [2,3], all-optical magnetization switching
[4, 5, 6, 7], and light-induced magnetic phase transitions [8] are just a few
notable examples. However, the transient nature of light-induced changes in the
magnetic state has been a significant limitation, hindering their practical
implementation. In this study, we demonstrate that infrared ultrashort laser
pulses can induce a ferromagnetic arrangement of magnetic moments in an
amorphous TbCo alloy, a material that exhibits ferrimagnetism under equilibrium
conditions. Strikingly, the observed changes in the magnetic properties persist
for significantly longer durations than any previously reported findings. Our
results reveal that ultrashort optical pulses can generate materials with
identical chemical composition and structural state but entirely distinct
magnetic arrangements, leading to unique magnetic properties. This breakthrough
discovery marks a new era in light-driven control of matter, offering the
exciting potential to create materials with properties that were once
considered unattainable.",2311.05507v2
2023-11-26,Electric Field Switching of Magnon Spin Current in a Compensated Ferrimagnet,"Manipulation of directional magnon propagation, known as magnon spin current,
is essential for developing magnonic memory and logic devices featuring
nonvolatile functionalities and ultralow power consumption. Magnon spin current
can usually be modulated by magnetic field or current-induced spin torques.
However, these approaches may lead to energy dissipation caused by Joule
heating. Electric-field switching of magnon spin current without charge current
is highly desired but very challenging to realize. By integrating magnonic and
piezoelectric materials, we demonstrate manipulation of the magnon spin current
generated by the spin Seebeck effect in the ferrimagnetic insulator Gd3Fe5O12
(GdIG) film on a piezoelectric substrate. We observe reversible electric-field
switching of magnon polarization without applied charge current. Through
strain-mediated magnetoelectric coupling, the electric field induces the
magnetic compensation transition between two magnetic states of the GdIG,
resulting in its magnetization reversal and the simultaneous switching of
magnon spin current. Our work establishes a prototype material platform that
pave the way for developing magnon logic devices characterized by all electric
field reading and writing and reveals the underlying physics principles of
their functions.",2311.15183v1
2023-11-30,Criteria to observe single-shot all-optical switching in Gd-based ferrimagnetic alloys,"Single-shot all-optical helicity-independent switching (AO-HIS) induced by a
femto-second laser pulse has been mainly reported in Gadolinium based rare
earth-transition metal (RE-TM) alloys such as GdFeCo or GdCo, but the mechanism
leading to magnetization switching is a hotly debated topic. Here, we elaborate
on a large number of GdyRE1-x-yCox (RE = Dy, Tb, Ho) alloys to tune various
magnetic parameters in order to define what the criteria are for observing
AO-HIS in such systems. The state diagrams show that two laser fluences
thresholds must be considered:the fluence which induces the single laser pulse
switching (FSwitch) and the fluence at which the material breaks into a
multi-domain state (FMulti). Those two fluences are shown to behave very
differently as a function of the material properties and the laser pulse
duration. Taking into account the parameters defining the conditions for which
multi-domain states are created and considering only the angular momentum
transfer from the Gd sublattice to the rest of the system explains in large our
experimental results. The importance of the compensation in the ferrimagnetic
alloys is also discussed. We believe the defined criteria will be an important
tool for designing new ultra-fast spintronic devices based on all optical
switching.",2311.18359v1
2023-12-07,Features of magnetization and spin reorientation in weak ferrimagnets of the YFe$_{1-x}$Cr$_x$O$_3$ type,"A brief critical review is given of the 50-year history of experimental and
theoretical studies of the magnetic properties of a new promising class of weak
ferrimagnets such as RFe$_{1-x}$Cr$_x$O$_3$ with a non-magnetic R-ion (R = La ,
Y, Lu), i.e. systems with competing signs of the Dzyaloshinsky vectors Fe-Fe,
Cr-Cr and Fe-Cr. The spin Hamiltonian of the system is considered taking into
account isotropic exchange, antisymmetric Dzyaloshinsky-Moriya exchange, and
second- and fourth-order single-ion anisotropy. Within the framework of the
molecular field approximation, calculations were made of the Neel temperatures,
the average magnetic moments of $3d$ ions, total and partial magnetizations,
and effective anisotropy constants. The existence in the model system
YFe$_{1-x}$Cr$_x$O$_3$ of two regions of negative magnetization $0.25 \leq
x\leq 0.5$ and $x\approx 0.8$ with the corresponding magnetization reversal
points reaching room temperature at $x\approx 0.45$. The phenomenon of spin
reorientation observed for single-crystal samples in a wide range of
concentrations is explained by a sharp decrease in the contribution of
antisymmetric exchange to magnetic anisotropy with increasing deviation from
the parent compositions and competition between the contributions of single-ion
anisotropy of Fe and Cr ions. It has been suggested that the spatial
orientation of the Neel ${\bf G}$ vector and the $G_{xyz}$ configuration are
the reason for the small value of saturation magnetization observed
experimentally for compositions inside or near the region of negative
magnetization.",2312.04381v2
2024-01-03,Spin-Transfer-Torque Induced Spatially Nonuniform Switching in Ferrimagnets,"Ferrimagnet (FiM), (FeCo)1-xGdx, attracts research attention due to its
ultrafast magnetic dynamics and finite net magnetization. Incorporating FiM
into the magnetic tunnel junction will be beneficial to further improve the
writing speed of magnetic random access memory (MRAM). It is commonly assumed
that the FeCo and Gd atoms are switched together due to the strong exchange
coupling, which remains valid even if one performs the two-sublattice macrospin
simulation. Interestingly, using the atomistic model developed by our group, it
is clearly seen that different atoms are not switched together. In addition,
our study reveals that the nature of switching is spatially nonuniform even in
the small sample with the dimension of 20 nm-20 nm. Furthermore, the
characteristics of nonuniformity are completely different for samples with
different Gd composition (x). When x is close to the magnetization compensation
point, successful switching cannot be obtained, but is accompanied by the
stable oscillation. The atom type that dominates the oscillation is different
from that predicted by the two-sublattice macrospin model. In addition, the
size of singular region is a non-monotonic function of current density. All
these results can only be understood by considering the spatial nonuniform
magnetization dynamics.",2401.01741v1
2024-01-09,Coexistence of large anomalous Nernst effect and large coercive force in amorphous ferrimagnetic TbCo alloy films,"The Anomalous Nernst Effect (ANE) has garnered significant interest for
practical applications, particularly in energy harvesting and heat flux
sensing. For these applications, it is crucial for the module to operate
without an external magnetic field, necessitating a combination of a large ANE
and a substantial coercive force. However, most materials exhibiting a large
ANE typically have a relatively small coercive force. In our research, we have
explored the ANE in amorphous ferrimagnetic TbCo alloy films, noting that the
coercive force peaks at the magnetization compensation point (MCP). We observed
that transverse Seebeck coefficients are amplified with Tb doping, reaching
more than 1.0 uV/K over a wide composition range near the MCP, which is three
times greater than that of pure Co. Our findings indicate that this enhancement
is primarily due to direct conversion, a product of the transverse
thermoelectric component and electrical resistivity. TbCo films present several
significant advantages for practical use: a large ANE, the capability to
exhibit both positive and negative ANE, the flexibility to be deposited on any
substrate due to their amorphous nature, a low thermal conductivity, and a
large coercive force. These attributes make TbCo films a promising material for
advancing ANE-based technologies.",2401.04445v1
2024-03-19,Interlayer Dzyaloshinskii-Moriya interaction in synthetic ferrimagnets,"The antisymmetric interlayer exchange interaction, i.e., interlayer
Dzyaloshinskii-Moriya interaction (IL-DMI) has attracted significant interest
since this long-range chiral spin interaction provides a new dimension for
controlling spin textures and dynamics. However, the role of IL-DMI in the
field induced and spin-orbit torque (SOT) induced switching of synthetic
ferrimagnets (SFi) has not been uncovered. Here, we exploit interlayer chiral
exchange bias fields in SFi to address both the sign and magnitude of the
IL-DMI. Depending on the degree of imbalance between the two magnetic moments
of the SFi, the amount of asymmetry, addressed via loop shifts of the
hysteresis loops under an in-plane field reveals a unidirectional and chiral
nature of the IL-DMI. The devices are then tested with SOT switching
experiments and the process is examined via both transient state and steady
state detection. In addition to field-free SOT switching, we find that the
combination of IL-DMI and SOT give rise to multi-resistance states, which
provides a possible direction for the future design of neuromorphic computing
devices based on SOT. This work is a step towards characterizing and
understanding the IL-DMI for spintronic applications.",2403.12642v1
2024-04-06,Insights on induced magnetic moments and spin textures in synthetic ferrimagnetic Pt/Co/Gd heterolayers,"To develop new devices based on synthetic ferrimagnetic (S-FiM)
heterostructures, understanding the material's physical properties is pivotal.
Here, the induced magnetic moment (IMM), magnetic exchange-coupling, and spin
textures were investigated at room-temperature in Pt/Co/Gd multilayers using a
multiscale approach. The magnitude and direction of the IMM were interpreted
experimentally and theoretically in the framework of both X-ray magnetic
circular dichroism (XMCD) and density functional theory (DFT). The results
demonstrate that the IMM transferred by Co across the Gd paramagnetic (PM)
thickness leads to a flipped spin state (FSS) within the Gd layers, in which
their magnetic moments couple antiparallel/parallel with the ferromagnetic (FM)
Co near/far from the Co/Gd interface, respectively. For the Pt, in both Pt/Co
and Gd/Pt interfaces the IMM follows the same direction as the Co magnetic
moment, with negligible IMM in the Gd/Pt interface. Additionally, zero-field
spin spirals were imaged using scanning transmission X-ray microscopy (STXM),
while micromagnetic simulations employed to unfold the interactions stabilizing
the FiM configurations, where the existence of a sizable Dzyaloshinskii-Moriya
interaction is demonstrated to be crucial for the formation of those spin
textures. Our outcomes may add fundamental physical and technological aspects
for using FiM films in antiferromagnetic spintronic devices.",2404.04655v1
2012-11-12,Cyclotron resonant interactions in cosmic particle accelerators,"A review is given for cyclotron resonant interactions in space plasmas. After
giving a simple formulation for the test particle approach, illustrative
examples for resonant interactions are given. It is shown that for obliquely
propagating whistler waves, not only fundamental cyclotron resonance, but also
other resonances, such as transit-time resonance, anomalous cyclotron
resonance, higher-harmonic cyclotron resonance, and even subharmonic resonance
can come into play. A few recent topics of cyclotron resonant interactions,
such as electron injection in shocks, cyclotron resonant heating of solar wind
heavy ions, and relativistic modifications, are also reviewed.",1211.2852v1
2008-04-21,Coupled-Resonator Optical Near-Field Lithography,"The problem of pattern formation in resonantly-enhanced near-field
lithography by the use of dielectric or plasmonic planar resonators is
investigated. Sub-diffraction-limited bright or dark spots can be produced by
taking advantage of the rotational invariance of planar resonators. To increase
the spatial bandwidth of the resonant enhancement, an array of coupled planar
resonators can open up a band of Bloch resonances, analogous to
coupled-resonator optical waveguides.",0804.3374v1
2004-07-20,Mapping of Euclidean resonance on static resonant tunneling,"Quantum tunneling through an almost classical potential barrier can be
strongly enhanced by a nonstationary field so that the penetration through the
barrier becomes not exponentially small. This constitutes an extremely unusual
phenomenon of quantum physics called Euclidean resonance. A certain
nonstationary barrier is proposed with a very low WKB tunneling rate. The
quantum dynamics of this barrier is mapped on resonant tunneling across a
static double barrier with a resonant level inside. The real penetration
through the dynamical barrier is not exponentially small providing an example
of Euclidean resonance. Therefore, the Schoedinger equation allows solutions of
the type of Euclidean resonance. The counterintuitive phenomenon of Euclidean
resonance is a dynamical analogue of static resonant tunneling.",0407163v1
2011-07-30,Enhancement of second harmonic generation in a doubly resonant metamaterial,"We investigate second harmonic (SH) generation in a doubly resonant
metamaterial. We show that SH generation can be enhanced when the resonant
condition is satisfied for the SH frequency as well as for the fundamental
frequency. A unit cell of the doubly resonant metamaterial consists of two
coupled resonators, one of which resonates at the fundamental frequency,
whereas the other resonates around the SH frequency. We observe that the SH
generation in the doubly resonant metamaterial is 4.6 times as large as that in
a singly resonant metamaterial.",1108.0044v1
2013-03-03,Optomechanical Transductions in Single and Coupled Wheel Resonators,"In this report, the optomechanical transductions in both single and two
side-coupled wheel resonators are investigated. In the single resonator, the
optomechanical transduction sensitivity is determined by the optical and
mechanical quality factors of the resonator. In the coupled resonators, the
optomechanical transduction is related to the energy distribution in the two
resonators, which is strongly dependent on the input detuning. Compared to a
single resonator, the coupled resonators can still provide very sensitive
optomechanical transduction even if the optical and mechanical quality factors
of one resonator are degraded.",1303.0440v1
2015-03-20,Frequency stabilization of the non resonant wave of a continuous-wave singly resonant optical parametric oscillator,"We present an experimental technique allowing to stabilize the frequency of
the non resonant wave in a singly resonant optical parametric oscillator (SRO)
down to the kHz level, much below the pump frequency noise level. By comparing
the frequency of the non resonant wave with a reference cavity, the pump
frequency noise is imposed to the frequency of the resonant wave, and is thus
subtracted from the frequency of the non resonant wave. This permits the non
resonant wave obtained from such a SRO to be simultaneously powerful and
frequency stable, which is usually impossible to obtain when the resonant wave
frequency is stabilized.",1503.06138v1
2009-12-05,Delta-Interference of Two Friedel Resonances,"When a single resonator is coupled to a continuous spectrum one obtains a
resonance of finite half-width. Such a resonance is known in many fields of
physics. The Friedel resonance is an example where a d-impurity is dissolved in
a simple metal. If two resonators are coupled to the continuous spectrum the
resonances interfere. For identical coupling and frequencies one obtains two
effective resonances. The effective coupling of one of them to the continuum
can be tuned to zero yielding a delta-like resonance.",0912.1049v1
2012-01-25,Efficient second harmonic generation in a metamaterial with two resonant modes coupled through two varactor diodes,"We present an effective method to generate second harmonic (SH) waves using
nonlinear metamaterial composed of coupled split ring resonators (CSRRs) with
varactor (variable capacitance) diodes. The CSRR structure has two resonant
modes: a symmetric mode that resonates at the fundamental frequency and an
anti-symmetric mode that resonates at the SH frequency. Resonant fundamental
waves in the symmetric mode generate resonant SH waves in the anti-symmetric
mode. The double resonance contributes to effective SH radiation. In the
experiment, we observe 19.6 dB enhancement in the SH radiation in comparison
with the nonlinear metamaterial that resonates only for the fundamental waves.",1201.5196v1
2023-09-25,New narrow resonance in the $e^+ e^- \to φη$ data by Belle collaboration,"Fitting the recent $e^+e^-\ra\phi\,\eta$ data by the Belle collaboration with
a theoretical formula reveals, besides the dominant $\phi(1680)$ resonance, two
narrow resonances: expected $\phi(2170)$ resonance and an unexpected resonance
with the mass of about 1851 MeV. Close proximity to the $X(1835)$ resonance
suggests that the new resonance may be interpreted as the $p \bar p$ baryonium
in an excited state. Follow-up analysis found the same resonance also in
$e^+e^-\ra\omega\,\eta$ data by CMD-3 experiment.",2309.14520v2
2023-10-10,Mean-Motion Resonances in the Quadrantid Meteoroid Stream and Dynamic Evolution of Dust Trail of (196256) 2003 EH1,"The paper presents numerical models of mean-motion resonances detected in the
Quadrantid meteoroid stream consisting of particles of mass 0.003 to 0.03 g,
which helps to prove the presence of the following mean-motion resonances: the
1:9 resonance with Venus, 1:5 resonance with Earth, 1:3 and 3:8 resonances with
Mars, and 2:1,7:3, 9:4 resonances with Jupiter. Resonance particles create dust
trails far from the Earth orbit. Indeed, there is no observational support for
resonant effects in the observed Quadrantid meteoroid stream.",2310.07037v1
2023-07-12,exoMMR: a New Python Package to Confirm and Characterize Mean Motion Resonances,"The study of orbital resonances allows for the constraint of planetary
properties of compact systems. We can predict a system's resonances by
observing the orbital periods of the planets, as planets in or near mean motion
resonance have period ratios that reduce to a ratio of small numbers. However,
a period ratio near commensurability does not guarantee a resonance; we must
study the system's dynamics and resonant angles to confirm resonance. Because
resonances require in-depth study to confirm, and because two-body resonances
require a measurement of the eccentricity vector which is quite challenging,
very few resonant pairs or chains have been confirmed. We thus remain in the
era of small number statistics, not yet able to perform large population
synthesis or informatics studies. To address this problem, we build a python
package to find, confirm, and analyze mean motion resonances, primarily through
N-body simulations. We then analyze all near-resonant planets in the Kepler/K2
and TESS catalogues, confirming over 60 new resonant pairs and various new
resonant chains. We additionally demonstrate the package's functionality and
potential by characterizing the mass-eccentricity degeneracy of Kepler-80g,
exploring the likelihood of an exterior giant planet in Kepler-80, and
constraining the masses of planets in Kepler-305. We find that our methods
overestimate the libration amplitudes of the resonant angles and struggle to
confirm resonances in systems with more than three planets. We identify various
systems that are likely resonant chains but that we are unable to confirm, and
highlight next steps for exoplanetary resonances.",2307.06171v1
2005-06-09,Transversal plasma resonance in a nonmagnetized plasma and possibilities of practical employment of it,"It is shown that in a nonmagnetized plasma, beside the longitudinal Langmuir
resonance, there may also exist the transversal resonance. Both these resonance
kinds are degenerated. Employment of the transversal resonance makes it
possible to design resonators and filters, as well as powerful single-frequency
lasers operating on the basis of collective oscillations of plasma.",0506081v1
2007-10-30,On the ambiguity of the interfering resonances parameters determination,"In this paper the interfering resonances parameters determination ambiguity
is considered. It is shown that there are two solutions for two fixed width
resonances. Analytical relation between different solutions is derived. Numeric
experiments for fixed width three and four resonances, and for model
energy-dependent width two resonances confirm ambiguity of the resonances
parameters determination.",0710.5627v1
2011-06-06,Optimal lower bound of the resonance widths for a Helmhotz tube-shaped resonator,"The study of the resonances of the Helmholtz resonator has been broadly
described in previous works. Here, for a simple tube-shaped two dimensional
resonator, we can perform a careful analysis of the transition zone where
oscillations start to appear. In that way, we obtain an optimal lower bound of
the width of the resonances.",1106.0990v1
2012-08-17,All-Resonant Control of Superconducting Resonators,"An all-resonant method is proposed to control the quantum state of
superconducting resonators. This approach uses a tunable artificial atom
linearly coupled to resonators, and allows for efficient routes to Fock state
synthesis, qudit logic operations, and synthesis of NOON states. This resonant
approach is theoretically analyzed, and found to perform signficantly better
than existing proposals using the same technology.",1208.3657v1
2018-02-15,Effects of Symmetry Breaking in Resonance Phenomena,"We show that resonance phenomena can be treated as nonequilibrium phase
transitions. Resonance phenomena, similar to equilibrium phase transitions, are
accompanied by some kind of symmetry breaking and can be characterized by order
parameters. This is demonstrated for spin-wave resonance, helicon resonance,
and spin-reversal resonance.",1802.05589v1
2017-09-04,Excited resonance widths for Helmholtz resonators with straight neck,"We consider resonances associated with excited eigenvalues of the cavity of a
general Helmholtz resonator with straight neck. Under the assumption that the
neck stays away from the nodal set of the corresponding eigenstate, we
generalise the optimal exponential lower bound on the width of the resonance,
that we have obtained in a previous paper for the ground resonance only.",1709.00894v1
2008-08-27,Epitaxial Zn(x)Fe(3-x)O(4) Thin Films: A Spintronic Material with Tunable Electrical and Magnetic Properties,"The ferrimagnetic spinel oxide Zn(x)Fe(3-x)O(4) combines high Curie
temperature and spin polarization with tunable electrical and magnetic
properties, making it a promising functional material for spintronic devices.
We have grown epitaxial thin films with 0<=x<=0.9 on MgO(001) substrates with
excellent structural properties both in pure Ar atmosphere and an Ar/O2 mixture
by laser molecular beam epitaxy. We find that the electrical conductivity and
the saturation magnetization can be tuned over a wide range during growth. Our
extensive characterization of the films provides a clear picture of the
underlying physics of this spinel ferrimagnet with antiparallel Fe moments on
the A and B sublattice: (i) Zn substitution removes both Fe3+ moments from the
A sublattice and itinerant charge carriers from the B sublattice, (ii) growth
in finite oxygen partial pressure generates Fe vacancies on the B sublattice
also removing itinerant charge carriers, and (iii) application of both Zn
substitution and excess oxygen results in a compensation effect as Zn
substitution partially removes the Fe vacancies. A decrease (increase) of
charge carrier density results in a weakening (strengthening) of double
exchange and thereby a decrease (increase) of conductivity and the saturation
magnetization. This scenario is confirmed by the observation that the
saturation magnetization scales with the longitudinal conductivity. The
combination of tailored films with semiconductor materials such as ZnO in
multi-functional heterostructures seems to be particularly appealing.",0808.3642v3
2010-04-14,Magnetic order on a frustrated spin-1/2 Heisenberg antiferromagnet on the Union Jack lattice,"We use the coupled cluster method (CCM) to study the zero-temperature phase
diagram of a 2D frustrated spin-half antiferromagnet, the so-called Union Jack
model. It is defined on a square lattice such that all nearest-neighbor bonds
are present with a strength $J_{1} > 0$, but only half the
next-nearest-neighbor bonds are present with a strength $J_{2} \equiv \kappa
J_{1} > 0$. The bonds are arranged such that on the $2 \times 2$ unit cell they
form the pattern of the Union Jack flag. We find strong evidence for a first
phase transition between a N\'{e}el phase and a canted ferrimagnetic phase at a
critical coupling $\kappa_{c_{1}} = 0.66 \pm 0.02$. At the transition the
energy and its first derivative seem continuous, thus providing a typical
scenario of a second-order transition, although a weakly first-order transition
cannot be excluded. By contrast, the average on-site magnetization $M$
approaches a nonzero value $M_{c_{1}}=0.195 \pm 0.005$ on both sides of the
transition, which is more typical of a first-order transition. The slope
$dM/d\kappa$ also appears to be continuous, or very nearly so, at the critical
point $\kappa_{c_{1}}$. We find strong evidence that the canted phase becomes
unstable at large values of $\kappa$, and hence we have also used the CCM with
a model collinear semi-stripe-ordered ferrimagnetic state in which alternating
rows (and columns) are ferromagnetically and antiferromagnetically ordered. We
find tentative evidence, based on the relative energies of the two states, for
a second (first-order) phase transition between the canted and
semi-stripe-ordered states at a large value of the coupling parameter around
$\kappa_{c_{2}} \approx 125 \pm 5$. This prediction, however, is based on an
extrapolation of the CCM results for the canted state into regimes where the
CCM equations at any level of approximation beyond the lowest have no
solutions.",1004.2339v2
2010-10-25,A frustrated quantum spin-${\boldmath s}$ model on the Union Jack lattice with spins ${\boldmath s>1/2}$,"The zero-temperature phase diagrams of a two-dimensional frustrated quantum
antiferromagnetic system, namely the Union Jack model, are studied using the
coupled cluster method (CCM) for the two cases when the lattice spins have spin
quantum number $s=1$ and $s=3/2$. The system is defined on a square lattice and
the spins interact via isotropic Heisenberg interactions such that all
nearest-neighbour (NN) exchange bonds are present with identical strength
$J_{1}>0$, and only half of the next-nearest-neighbour (NNN) exchange bonds are
present with identical strength $J_{2} \equiv \kappa J_{1} > 0$. The bonds are
arranged such that on the $2 \times 2$ unit cell they form the pattern of the
Union Jack flag. Clearly, the NN bonds by themselves (viz., with $J_{2}=0$)
produce an antiferromagnetic N\'{e}el-ordered phase, but as the relative
strength $\kappa$ of the frustrating NNN bonds is increased a phase transition
occurs in the classical case ($s \rightarrow \infty$) at $\kappa^{\rm
cl}_{c}=0.5$ to a canted ferrimagnetic phase. In the quantum cases considered
here we also find strong evidence for a corresponding phase transition between
a N\'{e}el-ordered phase and a quantum canted ferrimagnetic phase at a critical
coupling $\kappa_{c_{1}}=0.580 \pm 0.015$ for $s=1$ and $\kappa_{c_{1}}=0.545
\pm 0.015$ for $s=3/2$. In both cases the ground-state energy $E$ and its first
derivative $dE/d\kappa$ seem continuous, thus providing a typical scenario of a
second-order phase transition at $\kappa=\kappa_{c_{1}}$, although the order
parameter for the transition (viz., the average ground-state on-site
magnetization) does not go to zero there on either side of the transition.",1010.5161v1
2011-08-01,"Ferrimagnetism, Antiferromagnetism and Magnetic Frustration in La$_{2-x}$Sr$_{x}$CuRuO$_{6}$ (0 <= x <= 1)","We studied structural and magnetic properties of a series of insulating
double perovskite compounds, La$_{2-x}$Sr$_{x}$CuRuO$_{6}$ (0 $\le$ x $\le$ 1),
representing doping via \textit{A}-site substitution. The end members
La$_{2}$CuRuO$_{6}$ and LaSrCuRuO$_{6}$ form in monoclinic structure while the
intermediate Sr doped compounds stabilise in triclinic structure. The Cu and Ru
ions sit on alternate B-sites of the perovskite lattice with $\sim$15%
anti-site defects in the undoped sample while the Sr doped samples show a
tendency to higher ordering at B-sites. The undoped (x = 0) compound shows a
ferrimagnetic-like behaviour at low temperatures. In surprising contrast to the
usual expectation of an enhancement of ferromagnetic interaction on doping, an
antiferromagnetic-like ground state is realized for all doped samples (x $>$
0). Heat capacity measurements indicate the absence of any long range magnetic
order in any of these compounds. The magnetic relaxation and memory effects
observed in all compounds suggest glassy dynamical properties associated with
magnetic disorder and frustration. We show that the observed magnetic
properties are dominated by the competition between the nearest neighbour Ru --
O -- Cu 180$^\circ$ superexchange interaction and the next nearest neighbour Ru
-- O -- O -- Ru 90$^\circ$ superexchange interaction as well as by the
formation of anti-site defects with interchanged Cu and Ru positions. Our
calculated exchange interaction parameters from first principles calculations
for $x$ = 0 and $x$ = 1 support this interpretation.",1108.0334v3
2020-07-22,"Origin of the metamagnetic transitions in Y1-xErxFe2(H,D)4.2 compounds","The structural and magnetic properties of Y1-xErxFe2 intermetallic compounds
and their hydrides and deuterides Y1-xErxFe2H(D)4.2 have been investigated
using X-ray diffraction and magnetic measurements under static and pulsed
magnetic field up to 60 T. The intermetallics crystallize in the C15 cubic
structure , whereas corresponding hydrides and deuterides crystallize in a
monoclinic structure. All compounds display a linear decrease of the unit cell
volume versus Er concentration; the hydrides have a 0.8% larger cell volume
compared to the deuterides with same Er content. They are ferrimagnetic at low
field and temperature with a compensation point at x = 0.33 for the
intermetallics and x = 0.57 for the hydrides and deuterides. A sharp first
order ferromagnetic-antiferromagnetic (FM-AFM) transition is observed upon
heating at TFM-AFM for both hydrides and deuterides. These compounds show two
different types of field induced transitions, which have different physical
origin. At low temperature (T < 50 K), a forced ferri-ferromagnetic
metamagnetic transition with Btrans1 = 8 T, related to the change of the Er
moments orientation from antiparallel to parallel Fe moment, is observed.
Btrans1 is not sensitive to Er concentration, temperature and isotope effect. A
second metamagnetic transition resulting from antiferromagnetic to
ferrimagnetic state is also observed. The transition field Btrans2 increases
linearly versus temperature and relates to the itinerant electron metamagnetic
behavior of the Fe sublattice. An onset temperature TM0 is obtained by
extrapolating TFM-AFM (B) at zero field. TM0 decreases linearly versus the Er
content and is 45(5) K higher for the hydrides compared to the corresponding
deuteride. The evolution of TM0 versus cell volume shows that it cannot be
attributed exclusively to a pure volume effect and that electronic effects
should also be considered.",2007.11672v1
2017-04-05,"Structure, site-specific magnetism and magneto-transport properties of epitaxial D0$_{22}$ Mn$_2$Fe$_x$Ga thin films","Ferrimagnetic Mn$_2$Fe$_x$Ga $(0.26 \leq x \leq 1.12)$ thin films have been
characterised by X-ray diffraction, SQUID magnetometry, X-ray absorption
spectroscopy, X-ray magnetic circular dichroism and M\""{o}ssbauer spectroscopy
with the aim of determining the structure and site-specific magnetism of this
tetragonal, D0$_{22}$-structure Heusler compound. High-quality epitaxial films
with low RMS surface roughness ($\sim 0.6$ nm) are grown by magnetron
co-sputtering. The tetragonal distortion induces strong perpendicular magnetic
anisotropy along the $c$-axis with a typical coercive field $\mu_0 H\sim 0.8$ T
and an anisotropy field ranging from $6$ to $8$ T. Upon increasing the Fe
content $x$, substantial uniaxial anisotropy, $K_\mathrm{u} \geq 1.0$ MJ/m$^3$
can be maintained over the full $x$ range, while the magnetisation of the
compound is reduced from $400$ to $280$ kA/m. The total magnetisation is almost
entirely given by the sum of the spin moments originating from the
ferrimagnetic Mn and Fe sublattices, with the latter being coupled
ferromagnetically to one of the former. The orbital magnetic moments are
practically quenched, and have negligible contributions to the magnetisation.
The films with $x=0.73$ exhibit a high anomalous Hall angle of $2.5$ % and a
high Fermi-level spin polarisation, above $51$ %, as measured by point contact
Andreev reflection. The Fe-substituted Mn$_2$Ga films are highly tunable with a
unique combination of high anisotropy, low magnetisation, appreciable spin
polarisation and low surface roughness, making them very strong candidates for
thermally-stable spin-transfer-torque switching nanomagnets with lateral
dimensions down to $10$ nm.",1704.01326v1
2012-04-17,Magnetoelectric effects in single crystals of the cubic ferrimagnetic helimagnet Cu2OSeO3,"We present magnetodielectric measurements in single crystals of the cubic
spin-1/2 compound Cu$_2$OSeO$_3$. A magnetic field-induced electric
polarization ($\vec{P}$) and a finite magnetocapacitance (MC) is observed at
the onset of the magnetically ordered state ($T_c = 59$ K). Both $\vec{P}$ and
MC are explored in considerable detail as a function of temperature (T),
applied field $\vec{H}_a$, and relative field orientations with respect to the
crystallographic axes. The magnetodielectric data show a number of anomalies
which signal magnetic phase transitions, and allow to map out the phase diagram
of the system in the $H_a$-T plane. Below the 3up-1down collinear ferrimagnetic
phase, we find two additional magnetic phases. We demonstrate that these are
related to the field-driven evolution of a long-period helical phase, which is
stabilized by the chiral Dzyalozinskii-Moriya term $D \vec{M}
\cdot(\bs{\nabla}\times\vec{M})$ that is present in this non-centrosymmetric
compound. We also present a phenomenological Landau-Ginzburg theory for the
ME$_H$ effect, which is in excellent agreement with experimental data, and
shows three novel features: (i) the polarization $\vec{P}$ has a uniform as
well as a long-wavelength spatial component that is given by the pitch of the
magnetic helices, (ii) the uniform component of $\vec{P}$ points along the
vector $(H^yH^z, H^zH^x, H^xH^y)$, and (iii) its strength is proportional to
$\eta_\parallel^2-\eta_\perp^2/2$, where $\eta_\parallel$ is the longitudinal
and $\eta_\perp$ is the transverse (and spiraling) component of the magnetic
ordering. Hence, the field dependence of P provides a clear signature of the
evolution of a conical helix under a magnetic field. A similar phenomenological
theory is discussed for the MC.",1204.3783v1
2018-01-10,Prediction of a magnetic Weyl semimetal without spin-orbit coupling and strong anomalous Hall effect in the Heusler compensated ferrimagnet Ti2MnAl,"We predict a magnetic Weyl semimetal in the inverse Heusler Ti2MnAl, a
compensated ferrimagnet with a vanishing net magnetic moment and a Curie
temperature of over 650 K. Despite the vanishing net magnetic moment, we
calculate a large intrinsic anomalous Hall effect (AHE) of about 300 S/cm. It
derives from the Berry curvature distribution of the Weyl points, which are
only 14 meV away from the Fermi level and isolated from trivial bands.
Different from antiferromagnets Mn3X (X= Ge, Sn, Ga, Ir, Rh, and Pt), where the
AHE originates from the non-collinear magnetic structure, the AHE in Ti2MnAl
stems directly from the Weyl points and is topologically protected. The large
anomalous Hall conductivity (AHC) together with a low charge carrier
concentration should give rise to a large anomalous Hall angle. In contrast to
the Co-based ferromagnetic Heusler compounds, the Weyl nodes in Ti2MnAl do not
derive from nodal lines due to the lack of mirror symmetries in the inverse
Heusler structure. Since the magnetic structure breaks spin-rotation symmetry,
the Weyl nodes are stable without SOC. Moreover, because of the large
separation between Weyl points of opposite topological charge, the Fermi arcs
extent up to 75% of the reciprocal lattice vectors in length. This makes
Ti2MnAl an excellent candidate for the comprehensive study of magnetic Weyl
semimetals. It is the first example of a material with Weyl points, large
anomalous Hall effect and angle despite a vanishing net magnetic moment.",1801.03273v3
2020-01-03,"Effect of N, C and B interstitials on the structural and magnetic properties of alloys with Cu$_3$Au-structure","High-throughput density functional calculations are used to investigate the
effect of interstitial B, C and N atoms on 21 alloys reported to crystallize in
the cubic Cu$_3$Au structure. It is shown that the interstitials can have a
significant impact on the magneto-crystalline anisotropy energy (MAE), the
thermodynamic stability and the magnetic ground state structure, making these
alloys interesting for hard magnetic, magnetocaloric and other applications.
For 29 alloy/interstitial combinations the formation of stable alloys with
interstitial concentrations above 5\% is expected. In Ni$_3$Mn interstitial N
induces a tetragonal distortion with substantial uniaxial MAE for realistic N
concentrations. Mn$_3X$N$_x$ ($X$=Rh, Ir, Pt and Sb) are identified as alloys
with strong magneto-crystalline anisotropy. For Mn$_3$Ir we find a strong
enhancement of the MAE upon N alloying in the most stable collinear
ferrimagnetic state as well as in the non-collinear magnetic ground state.
Mn$_3$Ir and Mn$_3$IrN show also interesting topological transport properties.
The effect of N concentration and strain on the magnetic properties are
discussed. Further, the huge impact of N on the MAE of Mn$_3$Ir and a possible
impact of interstitial N on amorphous Mn$_3$Ir, a material that is
indispensable in today's data storage devices, are discussed at hand of the
electronic structure. For Mn$_3$Sb, non-collinear, ferrimagnetic and
ferromagnetic states are very close in energy, making this material potentially
interesting for magnetocaloric applications. For the investigated Mn alloys and
competing phases, the determination of the magnetic ground state is essential
for a reliable prediction of the phase stability.",2001.00959v1
2019-11-13,"Electronic structure investigation of GdNi using X-ray absorption, magnetic circular dichroism and hard x-ray photoemission spectroscopy","GdNi is a ferrimagnetic material with a Curie temperature Tc = 69 K which
exhibits a large magnetocaloric effect, making it useful for magnetic
refrigerator applications. We investigate the electronic structure of GdNi by
carrying out x-ray absorption spectroscopy (XAS) and x-ray magnetic circular
dichroism (XMCD) at T = 25 K in the ferrimagnetic phase. We analyze the Gd
M$_{4,5}$-edge ($3d$ - $4f$) and Ni L$_{2,3}$-edge ($2p$ - $3d$) spectra using
atomic multiplet and cluster model calculations, respectively. The atomic
multiplet calculation for Gd M$_{4,5}$-edge XAS indicates that Gd is trivalent
in GdNi, consistent with localized $4f$ states. On the other hand, a model
cluster calculation for Ni L$_{2,3}$-edge XAS shows that Ni is effectively
divalent in GdNi and strongly hybridized with nearest neighbour Gd states,
resulting in a $d$-electron count of 8.57. The Gd M$_{4,5}$-edge XMCD spectrum
is consistent with a ground state configuration of S = 7/2 and L=0. The Ni
L$_{2,3}$-edge XMCD results indicate that the antiferromagnetically aligned Ni
moments exhibit a small but finite magnetic moment ( $m_{tot}$ $\sim$ 0.12
$\mu_B$ ) with the ratio $m_{o}/m_{s}$ $\sim$ 0.11. Valence band hard x-ray
photoemission spectroscopy shows Ni $3d$ features at the Fermi level,
confirming a partially filled $3d$ band, while the Gd $4f$ states are at high
binding energies away from the Fermi level. The results indicate that the Ni
$3d$ band is not fully occupied and contradicts the charge-transfer model for
rare-earth based alloys. The obtained electronic parameters indicate that GdNi
is a strongly correlated charge transfer metal with the Ni on-site Coulomb
energy being much larger than the effective charge-transfer energy between the
Ni $3d$ and Gd $4f$ states.",1911.05306v2
2019-11-22,"Role of Element-Specific Damping on the Ultrafast, Helicity-Independent All-Optical Switching Dynamics in Amorphous (Gd,Tb)Co Thin Films","Ultrafast control of the magnetization in ps timescales by fs laser pulses
offers an attractive avenue for applications such as fast magnetic devices for
logic and memory. However, ultrafast helicity-independent all-optical switching
(HI-AOS) of the magnetization has thus far only been observed in Gd-based,
ferrimagnetic amorphous (\textit{a}-) rare earth-transition metal
(\textit{a}-RE-TM) systems, and a comprehensive understanding of the reversal
mechanism remains elusive. Here, we report HI-AOS in ferrimagnetic
\textit{a}-Gd$_{22-x}$Tb$_x$Co$_{78}$ thin films, from x = 0 to x = 18, and
elucidate the role of Gd in HI-AOS in \textit{a}-RE-TM alloys and multilayers.
Increasing Tb content results in increasing perpendicular magnetic anisotropy
and coercivity, without modifying magnetization density, and slower
remagnetization rates and higher critical fluences for switching but still
shows picosecond HI-AOS. Simulations of the atomistic spin dynamics based on
the two-temperature model reproduce these results qualitatively and predict
that the lower damping on the RE sublattice arising from the small spin-orbit
coupling of Gd (with $L = 0$) is instrumental for the faster dynamics and lower
critical fluences of the Gd-rich alloys. Annealing
\textit{a}-Gd$_{10}$Tb$_{12}$Co$_{78}$ leads to slower dynamics which we argue
is due to an increase in damping. These simulations strongly indicate that
acounting for element-specific damping is crucial in understanding HI-AOS
phenomena. The results suggest that engineering the element specific damping of
materials can open up new classes of materials that exhibit low-energy,
ultrafast HI-AOS.",1911.09803v3
2020-08-31,"Structural, magnetic and electronic properties of CaBaCo4-xMxO7 (M= Fe, Zn)","The effect of substituting iron and zinc for cobalt in CaBaCo$_4$O$_7$ has
been investigated using neutron diffraction and x-ray absorption spectroscopy.
The orthorhombic distortion present in the parent compound CaBaCo$_4$O$_7$
decreases with increasing the content of either Fe or Zn. The samples
CaBaCo$_3$ZnO$_7$ and CaBaCo$_{4-x}$Fe$_x$O$_7$ with $x \leq 1.5$ are
metrically hexagonal but much better refinements in the neutron diffraction
patterns are obtained using an orthorhombic unit cell. The two types of
substitution have opposite effects on the structural and magnetic properties.
Fe atoms preferentially occupy the sites at the triangular layer. Thus, the
replacement of Co by Fe supresses the ferrimagnetic ordering and
CaBaCo$_{4-x}$Fe$_x$O$_7$ samples are antiferromagnetically ordered with a new
propagation vector k=(1/3,0,0). However, the Zn atoms prefer occupying the
Kagome layer, which is very detrimental for the long range magnetic
interactions giving rise to a magnetic glass. The oxidation state of iron and
zinc is found to be 3+ and 2+, respectively, independently of the content.
Therefore, the average Co oxidation state changes accordingly with the
Fe$^{3+}$ or Zn$^{2+}$ doping. Also, x-ray absorption spectroscopy data
confirms the different preferential occupation for both Fe and Zn cations. The
combined information obtained by neutron diffraction and x-ray absorption
spectroscopy indicates that cobalt atoms can be either in a fluctuating
Co$^{2+}$/Co$^{3+}$ valence state or, alternatively, Co$^{2+}$ and Co$^{3+}$
ions being randomly distributed in the lattice. These results explain the
occurrence of local disorder in the CoO$_4$ tetrahedra obtained by EXAFS. An
anomaly in the lattice parameters and an increase in the local disorder is
observed only at the ferrimagnetic transition for CaBaCo$_4$O$_7$ revealing the
occurrence of local magneto-elastic coupling.",2008.13649v1
2021-04-14,Critical phenomena of the layered ferrimagnet Mn3Si2Te6 following proton irradiation,"We examine the magnetic properties of the quasi 2D ferrimagnetic single
crystal Mn3Si2Te6 (MST) through critical phenomena and magnetic entropy
analysis in the easy axis (H || ab) as a function of proton irradiance.
Employing a modified asymptotic analysis method, we find that upon proton
irradiation the critical exponents do not fall into any particular universality
class but lie close to mean field critical exponents ({\gamma} = 1, \b{eta} =
0.5). The presence of long-range interactions can be safely assumed for the
pristine and irradiated cases of MST examined in this work. Further analysis on
the effective spatial dimensionality reveal that MST remains at d = 3 under
proton irradiation transitioning from an n = 1 spin dimensionality to n = 2 and
n=3 for 1 x 10^15 and 5 x 10^15 H+/cm^2, indicating an XY interaction and a
Heisenberg interaction, respectively. The pair (spin-spin) correlation function
reveals an increase in magnetic correlations at the proton irradiance of 5 x
10^15 H+/cm^2. In conjunction, the maximum change in magnetic entropy obtained
from isothermal magnetization at 3 T is the largest for 5 x 10^15 H+/cm^2 with
a value of 2.45 J/kgK at T = 73.66 K, in comparison to 1.60 J/kgK for pristine
MST at T = 73 K. Magnetic entropy derived from zero-field heat capacity does
not show large deviations across the proton irradiated samples. This suggests
that the antiferromagnetic coupling between the Mn sites is stable even after
proton irradiation. Such result implies that magnetization is enhanced through
a strengthening of the super-exchange interaction between Mn atoms mediated
through Te rather than a weakening of the AFM component. Overall, our study
finds that the magnetic interactions are manipulated the greatest when MST is
irradiated at 5 x 10^15 H+/cm^2.",2104.06564v1
2021-05-28,Monte Carlo calculations of Curie temperatures of Y$_{1-x}$Gd$_x$(Fe$_{1-y}$Co$_y$)$_2$ pseudobinary system,"The close-packed AB$_2$ structures called Laves phases constitute the largest
group of intermetallic compounds. In this paper we computationally investigated
the pseudo-binary Laves phase system Y$_{1-x}$Gd$_x$(Fe$_{1-y}$Co$_y$)$_2$
spanning between the YFe$_2$, YCo$_2$, GdFe$_2$, and GdCo$_2$ vertices. While
the vast majority of the Y$_{1-x}$Gd$_x$(Fe$_{1-y}$Co$_y$)$_2$ phase diagram is
the ferrimagnetic phase, YCo$_2$ along with a narrow range of concentrations
around it is the paramagnetic phase. We presented results obtained by Monte
Carlo simulations of the Heisenberg model with parameters derived from
first-principles calculations. For calculations, we used the Uppsala atomistic
spin dynamics (UppASD) code together with the spin-polarized relativistic
Korringa-Kohn-Rostoker (SPR-KKR) code. From first principles we calculated the
magnetic moments and exchange integrals for the considered pseudo-binary
system, together with spin-polarized densities of states for boundary
compositions. Furthermore, we showed how the compensation point with the
effective zero total moment depends on the concentration in the considered
ferrimagnetic phases. However, the main result of our study was the
determination of the Curie temperature dependence for the system
Y$_{1-x}$Gd$_x$(Fe$_{1-y}$Co$_y$)$_2$. Except for the paramagnetic region
around YCo$_2$, the predicted temperatures were in good qualitative and
quantitative agreement with experimental results, which confirmed the ability
of the method to predict magnetic transition temperatures for systems
containing up to three different magnetic elements (Fe, Co, and Gd)
simultaneously. For the Y(Fe$_{1-y}$Co$_y$)$_2$ and Gd(Fe$_{1-y}$Co$_y$)$_2$
systems our calculations matched the experimentally-confirmed
Slater-Pauling-like behavior of T$_C$ dependence on the Co concentration.",2105.13844v1
2021-10-11,Transition of laser-induced terahertz spin currents from torque- to conduction-electron-mediated transport,"Spin transport is crucial for future spintronic devices operating at
bandwidths up to the terahertz (THz) range. In F|N thin-film stacks made of a
ferro/ferrimagnetic layer F and a normal-metal layer N, spin transport is
mediated by (1) spin-polarized conduction electrons and/or (2) torque between
electron spins. To identify a cross-over from (1) to (2), we study laser-driven
spin currents in F|Pt stacks where F consists of model materials with different
degrees of electrical conductivity. For the magnetic insulators YIG, GIG and
maghemite, identical dynamics is observed. It arises from the THz interfacial
spin Seebeck effect (SSE), is fully determined by the relaxation of the
electrons in the metal layer and provides an estimate of the spin-mixing
conductance of the GIG/Pt interface. Remarkably, in the half-metallic
ferrimagnet Fe3O4 (magnetite), our measurements reveal two spin-current
components with opposite direction. The slower, positive component exhibits SSE
dynamics and is assigned to torque-type magnon excitation of the A- and B-spin
sublattices of Fe3O4. The faster, negative component arises from the
pyro-spintronic effect and can consistently be assigned to ultrafast
demagnetization of e-sublattice minority-spin hopping electrons. This
observation supports the magneto-electronic model of Fe3O4. In general, our
results provide a new route to the contact-free separation of torque- and
conduction-electron-mediated spin currents.",2110.05462v2
2021-11-01,Localized-delocalized crossover of spin-carriers and magnetization reversal in Co$_{2}$VO$_{4}$,"Neutron diffraction, magnetization and muon spin relaxation measurements,
supplemented by density functional theory (DFT) calculations are employed to
unravel temperature-driven magnetization reversal (MR) in inverse spinel
Co$_2$VO$_4$. All measurements show a second-order magnetic phase transition at
$T_{\rm C} = 168$\,K to a collinear ferrimagnetic phase. The DFT results
suggest the moments in the ferrimagnetic phase are delocalized and undergo
gradual localization as the temperature is lowered below $T_{\rm C}$. The
delocalized-localized crossover gives rise to a maximum magnetization at
$T_{\rm NC} = 138$\,K and the continuous decrease in magnetization produces
sign-change at $T_{\rm MR} \sim 65$\,K. Muon spectroscopy results support the
DFT, as a strong $T_1$-relaxation is observed around $T_{\rm NC}$, indicating
highly delocalized spin-carriers gradually tend to localization upon cooling.
The magnetization reversal determined at zero field is found to be highly
sensitive to the applied magnetic field, such that above $B\sim 0.25$\,T
instead of a reversal a broad minimum in the magnetization is apparent at
$T_{\rm MR}$. Analysis of the neutron diffraction measurements shows two
antiparallel magnetic sub-lattice-structure, each belonging to magnetic ions on
two distinct crystal lattice sites. The relative balance of these two
structural components in essence determines the magnetization. Indeed, the
order parameter of the magnetic phase on one site develops moderately more than
that on the other site. Unusual tipping of the magnetic balance, caused by such
site-specific magnetic fluctuation, gives rise to a spontaneous flipping of the
magnetization as the temperature is lowered.",2111.00694v1
2021-11-26,"Room temperature weak collinear ferrimagnet with symmetry driven, large intrinsic magneto-optic signatures","Here we present a magnetic thin film with a weak ferrimagnetic (FIM) phase
above the N\'eel temperature ($T_{N}$ = 240 K) and a non-collinear
antiferromagnetic (AFM) phase below, exhibiting a small net magnetisation due
to strain-associated canting of the magnetic moments. A long-range ordered FIM
phase has been predicted in related materials, but without symmetry analysis.
We now perform this analysis and use it to calculate the MOKE spectra in AFM
and FIM phases. From the good agreement between the form of the measured and
predicted MOKE spectra, we propose the AFM and FIM phases share the magnetic
space group C2'/m' and that the symmetry driven magneto-optic and
magneto-transport properties are maximised at room temperature in the FIM phase
due to the non-zero intrinsic Berry phase contribution present in these
materials. A room temperature FIM phase with large optical and transport
signatures, as well as sensitivity to lattice strain and magnetic field, has
useful prospects for high-speed spintronic applications.",2111.13498v4
2022-04-24,Ground-state phase diagram and thermodynamics of coupled trimer chains,"The density matrix renormalization group and quantum Monte Carlo method are
used to describe coupled trimer chains in a magnetic field h. The Hamiltonian
contains exchange terms involving the intra-trimer coupling J1 (taken as the
unit of energy) and the inter-trimer coupling J2, plus the Zeeman interaction
for a magnetic field h along the z direction. Results for the magnetization per
trimer m are calculated in regimes of positive and negative values of the ratio
J = J2 / J1, from which the rich field-induced ground state phase diagram h vs.
J is derived, with the presence of Luttinger liquid, the 1/3-plateau (m = 1/2),
and the one of fully polarized magnetization (m = 3/2). Also, the zero-field
Lanczos calculation of spin-wave dispersion from the 1/3-plateau for $S^z = 1$
is shown at the previous regimes of J values. In addition, we also report on
the decay of correlation functions of trimers along open chains, as well as the
average two-magnon distribution. The ground state is ferrimagnetic for $0<J\leq
1$, and is a singlet for $-1\leq J<0$. In the singlet phase, the spin
correlation functions along the legs present an antiferromagnetic power-law
decay, similar to the spin-1/2 linear chain, thus suggesting that the ground
state is made of three coupled antiferromagnetically oriented chains. In the
singlet phase, the dimensionless thermal magnetic susceptibility per site
normalized by 1/|J| gets closer to $1/\pi^2$ as the temperature $T\rightarrow
0$. For the ferrimagnetic phase, we fit the susceptibility to the experimental
data for the compound Pb$_3$Cu$_3$(PO$_4$)$_4$ and estimate the model exchange
couplings: J1=74.8 K and J=0.4. These values imply a range of energies for the
magnon excitations that are in accord with the data from neutron scattering
experiments on Pb$_3$Cu$_3$(PO$_4$)$_4$ for two excitation modes. The
1/3-plateau closes only at 1/|J|=0 with J<0.",2204.11186v1
2022-10-27,Polyhedral distortions and unusual magnetic order in spinel FeMn$_{2}$O$_{4}$,"Spinel compounds AB$_{2}$X$_{4}$ consist of both tetrahedral (AX$_{4}$) and
octahedral (BX$_{6}$) environments with the former forming a diamond lattice
and the latter a geometrically frustrated pyrochlore lattice. Exploring the
fascinating properties and their correlations with structural features is
critical in understanding these materials. FeMn$_{2}$O$_{4}$ has been reported
to exhibit one structural transition and two successive magnetic transitions.
Here, we report the polyhedral distortions and their correlations to the
structural and two magnetic transitions in FeMn$_{2}$O$_{4}$ by employing the
high-resolution neutron powder diffraction. While a large trigonal distortion
is found even in the high-temperature cubic phase, the first-order
cubic-tetragonal structural transition associated with the elongation of both
tetrahedra and octahedra along the $c$ axis occurs at $T_{S} \approx$ 750 K,
driven by the Jahn-Teller effect of the orbital active B-site Mn$^{3+}$ cation.
A strong magnetoelastic coupling is unveiled at $T_{N1}\approx 400$ K as
manifested by the appearance of N\`{e}el-type collinear ferrimagnetic order, an
anomaly in both tetrahedral and octahedral distortions, as well as an anomalous
decrease of the lattice constant $c$ and a weak anomaly of $a$. Upon cooling
below $T_{N2}\approx65$ K, it evolves to a noncollinear ferrimagnetic order
with a canting of half B-site $Mn^{3+}$/$Fe^{3+}$ spins in the pyrochlore
lattice, which is a unique magnetic order among spinels. Such a noncollinear
order induces modifications of the O-B-O bond angles in the octahedra without
affecting much the bond lengths of the tetrahedra/octahedra. Our study
indicates that FeMn$_{2}$O$_{4}$ is a wonderful platform to unveil interesting
magnetic order and to investigate their correlations to polyhedral distortions
and lattice.",2210.15089v2
2022-11-28,Entropy engineering and tunable magnetic order in the spinel high entropy oxide,"Spinel oxides are an ideal setting to explore the interplay between
configurational entropy, site selectivity, and magnetism in high entropy
oxides. In this work we characterize the magnetic properties of the spinel
(Cr,Mn,Fe,Co,Ni)$_3$O$_4$ and study the evolution of its magnetism as a
function of non-magnetic gallium substitution. Across the range of compositions
studied here, from 0% to 40% Ga, magnetic susceptibility and powder neutron
diffraction measurements show that ferrimagnetic order is robust in the spinel
HEO. However, we also find that the ferrimagnetic order is highly tunable, with
the ordering temperature, saturated and sublattice moments, and magnetic
hardness all varying significantly as a function of Ga concentration. Through
x-ray absorption and magnetic circular dichroism, we are able to correlate this
magnetic tunability with strong site selectivity between the various cations
and the tetrahedral and octahedral sites in the spinel structure. In
particular, we find that while Ni and Cr are largely unaffected by the
substitution with Ga, the occupancies of Mn, Co, and Fe are each significantly
redistributed. Ga substitution also requires an overall reduction in the
transition metal valence, and this is entirely accommodated by Mn. Finally, we
show that while site selectivity has an overall suppressing effect on the
configurational entropy, over a certain range of compositions, Ga substitution
yields a striking increase in the configurational entropy and may confer
additional stabilization. Spinel oxides can be tuned seamlessly from the
low-entropy to the high-entropy regime, making this an ideal platform for
entropy engineering.",2211.15798v1
2022-12-26,In plane reorientation induced single laser pulse magnetization reversal in rare-earth based multilayer,"Single Pulse All Optical Helicity Independent Switching (AO-HIS) represents
the ability to reverse the magnetic moment of a nanostructure using a
femtosecond single laser pulse. It is an ultrafast method to manipulate
magnetization without the use of any applied field. Since the first switching
experiments carried on GdFeCo ferrimagnetic systems, single pulse AO-HIS has
been restricted for a while to Gd-based alloys or Gd/FM bilayers where FM is a
ferromagnetic layer. Only recently has AO-HIS been extended to a few other
materials: MnRuGa ferrimagnetic Heusler alloys and Tb/Co multilayers with a
very specific range of thickness and composition. Here, we demonstrate that
single pulse AO-HIS observed in Tb/Co results from a different mechanism than
the one for Gd based samples and that it can be obtained for a large range of
rare earth-transition metal (RE-TM) multilayers, making this phenomenon much
more general. Surprisingly, in this large family of (RE-TM) multilayer systems,
the threshold fluence for switching is observed to be independent of the pulse
duration, up to at least 12 ps. Moreover, at high laser intensities, concentric
ring domain structures are induced, unveiling multiple fluence thresholds.
These striking switching features, which are in contrast to those of AO-HIS in
GdFeCo alloys, concomitant with the demonstration of an in-plane reorientation
of the magnetization, point towards an intrinsic precessional reversal
mechanism. Our results allow expanding the variety of materials with tunable
magnetic properties that can be integrated in complex heterostructures and
provide a pathway to engineer materials for future applications based on
all-optical control of magnetic order.",2212.13279v1
2022-12-31,"Electrically Sign-Reversible Topological Hall Effect in a Top-Gated Topological Insulator (Bi,Sb)2Te3 on a Ferrimagnetic Insulator Europium Iron Garnet","Topological Hall effect (THE), an electrical transport signature of systems
with chiral spin textures like skyrmions, has been observed recently in
topological insulator (TI)-based magnetic heterostructures. However, the
intriguing interplay between the topological surface state and THE is yet to be
fully understood. In this work, we report a large THE of ~10 ohm (~4
micro-ohm*cm) at 2 K with an electrically reversible sign in a top-gated 4 nm
TI (Bi0.3Sb0.7)2Te3 (BST) grown on a ferrimagnetic insulator (FI) europium iron
garnet (EuIG). Temperature, external magnetic field angle, and top gate bias
dependences of magnetotransport properties were investigated and consistent
with a skyrmion-driven THE. Most importantly, a sign change in THE was
discovered as the Fermi level was tuned from the upper to the lower parts of
the gapped Dirac cone and vice versa. This discovery is anticipated to impact
technological applications in ultralow power skyrmion-based spintronics.",2301.00213v2
2023-01-12,Stripe Helical Magnetism and Two Regimes of Anomalous Hall Effect in NdAlGe,"We report the magnetic and electronic transport properties of the inversion
and time-reversal symmetry breaking Weyl semimetal NdAlGe. This material is
analogous to NdAlSi, whose helical magnetism presents a rare example of a
Weyl-mediated collective phenomenon, but with a larger spin-orbit coupling. Our
neutron diffraction experiments revealed that NdAlGe, similar to NdAlSi,
supports an incommensurate Ising spin density wave ($T_{\text{inc}}=6.8$ K)
with a small helical spin canting of 3$^\circ$ and a long-wavelength of $\sim$
35 nm, which transitions to a commensurate ferrimagnetic state below
$T_{\text{com}}=5.1$ K. Using small-angle neutron scattering, we showed that
the zero-field cooled ferrimagnetic domains form stripes in real space with
characteristic length scales of 18 nm and 72 nm parallel and perpendicular to
the [110] direction, respectively. Interestingly, for the transport properties,
NdAlSi does not exhibit an anomalous Hall effect (AHE) that is commonly
observed in magnetic Weyl semimetals. In contrast to NdAlSi, we identify two
different AHE regimes in NdAlGe that are respectively governed by intrinsic
Berry curvature and extrinsic disorders/spin fluctuations. Our study suggests
that Weyl-mediated magnetism prevails in this group of noncentrosymmetric
magnetic Weyl semimetals NdAl$X$, but transport properties including AHE are
affected by material-specific extrinsic effects such as disorders, despite the
presence of prominent Berry curvature.",2301.04893v2
2023-03-23,Harnessing van der Waals CrPS4 and Surface Oxides for non-monotonic pre-set field induced Exchange Bias in Fe3GeTe2,"Two-dimensional van der Waals (vdW) heterostructures are an attractive
platform for studying exchange bias due to their defect free and atomically
flat interfaces. Chromium thiophosphate (CrPS4), an antiferromagnetic material,
possesses uncompensated magnetic spins in a single layer, rendering it a
promising candidate for exploring exchange bias phenomena. Recent findings have
highlighted that naturally oxidized vdW ferromagnetic Fe3GeTe2 exhibits
exchange bias, attributed to the antiferromagnetic coupling of its ultrathin
surface oxide layer (O-FGT) with the underlying unoxidized Fe3GeTe2. Anomalous
Hall measurements are employed to scrutinize the exchange bias within the
CrPS4/(O-FGT)/Fe3GeTe2 heterostructure. This analysis takes into account the
contributions from both the perfectly uncompensated interfacial CrPS4 layer and
the interfacial oxide layer. Intriguingly, a distinct and non-monotonic
exchange bias trend is observed as a function of temperature below 140 K. The
occurrence of exchange bias induced by a 'pre-set field' implies that the
prevailing phase in the polycrystalline surface oxide is ferrimagnetic Fe3O4.
Moreover, the exchange bias induced by the ferrimagnetic Fe3O4 is significantly
modulated by the presence of the van der Waals antiferromagnetic CrPS4 layer,
forming a heterostructure, along with additional iron oxide phases within the
oxide layer. These findings underscore the intricate and complex nature of
exchange bias in van der Waals heterostructures, highlighting their potential
for tailored manipulation and control.",2303.13167v3
2023-06-21,Superconductivity and magnetism in the surface states of ABC-stacked multilayer graphene,"ABC-stacked multilayer graphene (ABC-MLG) exhibits topological surface flat
bands with a divergent density of states, leading to many-body instabilities at
charge neutrality. Here, we explore electronic ordering within a mean-field
approach with full generic treatment of all spin-isotropic, two-site charge
density and spin interactions up to next-nearest neighbor (NNN) sites. We find
that surface superconductivity and magnetism are significantly enhanced over
bulk values. We find spin-singlet $s$ wave and unconventional NNN bond
spin-triplet $f$ wave to be the dominant superconducting pairing symmetries,
both with a full energy gap. By establishing the existence of ferromagnetic
intra-sublattice interaction, $(J_2<0)$ we conclude that the $f$-wave state is
favored in ABC-MLG, in sharp contrast to bulk ABC-graphite where chiral $d$- or
$p$-wave states, together with s-wave states, display stronger ordering
tendencies albeit not achievable at charge neutrality. We trace this
distinctive surface behavior to the strong sublattice polarization of the
surface flat bands. We also find competing ferrimagnetic order, fully
consistent with density functional theory (DFT) calculations. The magnetic
order interpolates between sublattice ferromagnetism and antiferromagnetism,
but only with the ratio of the sublattice magnetic moments ($R$) being
insensitive to the DFT exchange correlation functional. We finally establish
the full phase diagram by constraining the interactions to the $R$-value
identified by DFT. We find $f$-wave superconductivity being favored for all
weak to moderately strong couplings $J_2$ and as long as $J_2$ is a
sufficiently large part of the full interaction mix. Gating ABC-MLG away from
charge neutrality further enhances the $f$-wave state over the ferrimagnetic
state, establishing ABC-MLG as a strong candidate for $f$-wave
superconductivity.",2306.12220v2
2023-09-12,Gap and magnetic engineering via doping and pressure in tuning the colossal magnetoresistance in (Mn$_{1-x}$Mg$_x$)$_3$Si$_2$Te$_6$,"Ferrimagnetic nodal-line semiconductor Mn$_3$Si$_2$Te$_6$ keeps the records
of colossal magnetoresistance (CMR) and angular magnetoresistance (AMR). Here
we report tuning the electronic transport properties via doping and pressure in
(Mn$_{1-x}$Mg$_x$)$_3$Si$_2$Te$_6$. As the substitution of nonmagnetic
Mg$^{2+}$ for magnetic Mn$^{2+}$, ferrimagnetic transition temperature $T_C$
gradually decreases, while the resistivity increases significantly. At the same
time, the CMR and AMR are both enhanced for the low-doping compositions (e.g.,
$x = 0.1$ and 0.2), which can be attributed to doping-induced broadening of the
band gap and a larger variation range of the resistivity when undergoing a
metal-insulator transition by applying a magnetic field along the $c$ axis. On
the contrary, $T_C$ rises with increasing pressure due to the enhancement of
the magnetic exchange interactions until a structural transition occurs at
$\sim$13 GPa. Meanwhile, the activation gap is lowered under pressure and the
magnetoresistance is decreased dramatically above 6 GPa where the gap is
closed. At 20 and 26 GPa, evidences for a superconducting transition at $\sim$5
K are observed. The results reveal that doping and pressure are effective
methods to tune the activation gap, and correspondingly, the CMR and AMR in
nodal-line semiconductors, providing an approach to investigate the
magnetoresistance materials for novel spintronic devices.",2309.05945v2
2023-10-13,High temperature ferrimagnetic semiconductors by spin-dependent doping in high temperature antiferromagnets,"To realize room temperature ferromagnetic (FM) semiconductors is still a
challenge in spintronics. Many antiferromagnetic (AFM) insulators and
semiconductors with high Neel temperature $T_N$ are obtained in experiments,
such as LaFeO$_3$, BiFeO$_3$, etc. High concentrations of magnetic impurities
can be doped into these AFM materials, but AFM state with very tiny net
magnetic moments was obtained in experiments, because the magnetic impurities
were equally doped into the spin up and down sublattices of the AFM materials.
Here, we propose that the effective magnetic field provided by a FM substrate
could guarantee the spin-dependent doping in AFM materials, where the doped
magnetic impurities prefer one sublattice of spins, and the ferrimagnetic (FIM)
materials are obtained. To demonstrate this proposal, we study the Mn-doped AFM
insulator LaFeO$_3$ with FM substrate of Fe metal by the density functional
theory (DFT) calculations. It is shown that the doped magnetic Mn impurities
prefer to occupy one sublattice of AFM insulator, and introduce large magnetic
moments in La(Fe,Mn)O$_3$. For the AFM insulator LaFeO$_3$ with high $T_N$ =
740 K, several FIM semiconductors with high Curie temperature $T_C >$ 300 K and
the band gap less than 2 eV are obtained by DFT calculations, when 1/8 or 1/4
Fe atoms in LaFeO$_3$ are replaced by the other 3d, 4d transition metal
elements. The large magneto-optical Kerr effect (MOKE) is obtained in these
LaFeO$_3$-based FIM semiconductors. In addition, the FIM semiconductors with
high $T_C$ are also obtained by spin-dependent doping in some other AFM
materials with high $T_N$, including BiFeO$_3$, SrTcO$_3$, CaTcO$_3$, etc. Our
theoretical results propose a way to obtain high $T_C$ FIM semiconductors by
spin-dependent doping in high $T_N$ AFM insulators and semiconductors.",2310.09061v1
2011-12-06,The periodic and chaotic regimes of motion in the exoplanet 2/1 mean-motion resonance,"We present the dynamical structure of the phase space of the planar planetary
2/1 mean-motion resonance (MMR). Inside the resonant domain, there exist two
families of periodic orbits, one associated to the librational motion of the
critical angle ($\sigma$-family) and the other related to the circulatory
motion of the angle between the pericentres ($\Delta\varpi$-family). The
well-known apsidal corotation resonances (ACR) appear at the intersections of
these families. A complex web of secondary resonances exists also for low
eccentricities, whose strengths and positions are dependent on the individual
masses and spatial scale of the system.
  Depending on initial conditions, a resonant system is found in one of the two
topologically different states, referred to as \textit{internal} and
\textit{external} resonances. The internal resonance is characterized by
symmetric ACR and its resonant angle is $2\,\lambda_2-\lambda_1-\varpi_1$,
where $\lambda_i$ and $\varpi_i$ stand for the planetary mean longitudes and
longitudes of pericentre, respectively. In contrast, the external resonance is
characterized by asymmetric ACR and the resonant angle is
$2\,\lambda_2-\lambda_1-\varpi_2$. We show that systems with more massive outer
planets always envolve inside internal resonances. The limit case is the
well-known asteroidal resonances with Jupiter. At variance, systems with more
massive inner planets may evolve in either internal or external resonances; the
internal resonances are typical for low-to-moderate eccentricity
configurations, whereas the external ones for high eccentricity configurations
of the systems. In the limit case, analogous to Kuiper belt objects in
resonances with Neptune, the systems are always in the external resonances
characterized by asymmetric equilibria.",1112.1208v1
2019-09-11,An Integrable Model for the Dynamics of Planetary Mean Motion Resonances,"I consider the dynamics of mean motion resonances between pairs of co-planar
planets and derive a new integrable Hamiltonian model for planets' resonant
motion. The new model generalizes previously-derived integrable Hamiltonians
for first-order resonances to treat higher-order resonances by exploiting a
surprising near-symmetry of the full, non-integrable Hamiltonians of
higher-order resonances. Whereas past works have frequently relied on truncated
disturbing function expansions to derive integrable approximations to resonant
motion, I show that no such expansion is necessary, thus enabling the new model
to accurately capture the dynamics of both first- and higher-order resonances
for eccentricities up to orbit-crossing. I demonstrate that predictions of the
new integrable model agree well with numerical integrations of resonant planet
pairs. Finally, I explore the secular evolution of resonant planets'
eccentricities. I show that the secular dynamics are governed by conservation
of an AMD-like quantity.
  I also demonstrate that secular frequencies depend on planets' resonant
libration amplitude and this generally gives rise to a secular resonance inside
the mean motion resonance at large libration amplitudes. Outside of the secular
resonance the long-term dynamics are characterized small adiabatic modulations
of the resonant motion while inside the secular resonance planets can
experience large variations of the resonant trajectory over secular timescales.
The integrable model derived in this work can serve as a framework for
analyzing the dynamics of planetary MMRs in a wide variety of contexts.",1909.05264v1
2022-02-23,Resonators with tailored optical path by cascaded-mode conversions,"Optical resonators enable the generation, manipulation, and storage of
electromagnetic waves. They are widely used in technology and fundamental
research, in telecommunications, lasers and nonlinear optics, ultra-sensitive
measurements in cavity optomechanics, and the study of light-matter
interactions in the context of cavity QED. The physics underlying their
operation is determined by the constructive interference of electromagnetic
waves at specific frequencies, giving rise to the resonance spectrum. This
mechanism causes the limitations and trade-offs of resonator design, such as
the difficulty of confining waves larger than the resonator and the fixed
relationship between free spectral range, modal linewidth, and the resonator's
refractive index and size. Here, we introduce a new class of optical
resonators, generating resonances by designing the optical path through
transverse mode coupling in a cascaded process created by mode-converting
mirrors. The generalized round-trip phase condition leads to resonator
characteristics that are markedly different from Fabry-Perot resonators and can
be tailored over a wide range, such as the largest resonant wavelength, the
free spectral range, the linewidth, and the quality factor. We confirm the
existence of these modes experimentally in an integrated waveguide cavity with
mode converters coupling two transverse modes into one supermode. The resonance
signature of the cascaded-mode resonator is a spectrum resulting from the
coherent superposition of the coupled transverse modes. We also demonstrate a
transverse mode-independent transmission through the resonator and show that
its engineered spectral properties agree with theoretical predictions.
Cascaded-mode resonators introduce properties not found in traditional
resonators and provide a mechanism to overcome the existing trade-offs in the
design of resonators in various application areas.",2202.11775v1
2023-11-27,Selective active resonance tuning for multi-mode nonlinear photonic cavities,"Resonant enhancement of nonlinear photonic processes is critical for the
scalability of applications such as long-distance entanglement generation. To
implement nonlinear resonant enhancement, multiple resonator modes must be
individually tuned onto a precise set of process wavelengths, which requires
multiple linearly-independent tuning methods. Using coupled auxiliary
resonators to indirectly tune modes in a multi-resonant nonlinear cavity is
particularly attractive because it allows the extension of a single physical
tuning mechanism, such as thermal tuning, to provide the required independent
controls. Here we model and simulate the performance and tradeoffs of a
coupled-resonator tuning scheme which uses auxiliary resonators to tune
specific modes of a multi-resonant nonlinear process. Our analysis determines
the tuning bandwidth for steady-state mode field intensity can significantly
exceed the inter-cavity coupling rate if the total quality factor of the
auxiliary resonator is higher than the multi-mode main resonator. Consequently,
over-coupling a nonlinear resonator mode to improve the maximum efficiency of a
frequency conversion process will simultaneously expand the auxiliary resonator
tuning bandwidth for that mode, indicating a natural compatibility with this
tuning scheme. We apply the model to an existing small-diameter triply-resonant
ring resonator design and find that a tuning bandwidth of 136 GHz ~ 1.1 nm can
be attained for a mode in the telecom band while limiting excess scattering
losses to a quality factor of 10^6. Such range would span the distribution of
inhomogeneously broadened quantum emitter ensembles as well as resonator
fabrication variations, indicating the potential for the auxiliary resonators
to enable not only low-loss telecom conversion but also the generation of
indistinguishable photons in a quantum network.",2311.15606v1
2023-11-25,Ultrasensitive vibrational resonance induced by small disturbances,"We have found two kinds of ultra-sensitive vibrational resonance in coupled
nonlinear systems. It is particularly worth pointing out that this
ultra-sensitive vibrational resonance is a transient behavior caused by
transient chaos. Considering long-term response, the system will transform from
transient chaos to periodic response. The pattern of vibrational resonance will
also transform from ultra-sensitive vibrational resonance to conventional
vibrational resonance. This article focuses on the transient ultra-sensitive
vibrational resonance phenomenon. It is induced by a small disturbance of the
high-frequency excitation and the initial simulation conditions, respectively.
The damping coefficient and the coupling strength are the key factors to induce
the ultra-sensitive vibrational resonance. By increasing these two parameters,
the vibrational resonance pattern can be transformed from an ultra-sensitive
vibrational resonance to a conventional vibrational resonance. The reason for
different vibrational resonance patterns to occur lies in the state of the
system response. The response usually presents transient chaotic behavior when
the ultra-sensitive vibrational resonance appears and the plot of the response
amplitude versus the controlled parameters shows a highly fractalized pattern.
When the response is periodic or doubly-periodic, it usually corresponds to the
conventional vibrational resonance. The ultra-sensitive vibrational resonance
not only occurs at the excitation frequency, but it also occurs at some more
nonlinear frequency components. The ultra-sensitive vibrational resonance as a
transient behavior and the transformation of vibrational resonance patterns are
new phenomena in coupled nonlinear systems.",2312.11474v1
2018-04-18,"Electromagnetic-Power-based Modal Classification, Modal Expansion, and Modal Decomposition for Perfect Electric Conductors","Traditionally, all working modes of a perfect electric conductor are
classified into capacitive modes, resonant modes, and inductive modes, and the
resonant modes are further classified into internal resonant modes and external
resonant modes. In this paper, the capacitive modes are further classified into
intrinsically capacitive modes and non-intrinsically capacitive modes; the
resonant modes are alternatively classified into intrinsically resonant modes
and non-intrinsically resonant modes, and the intrinsically resonant modes are
further classified into non-radiative intrinsically resonant modes and
radiative intrinsically resonant modes; the inductive modes are further
classified into intrinsically inductive modes and non-intrinsically inductive
modes. Based on the modal expansion corresponding to these new modal
classifications, an alternative modal decomposition method is proposed. In
addition, it is also proved that: all intrinsically resonant modes and all
non-radiative intrinsically resonant modes constitute linear spaces
respectively, but other kinds of resonant modes cannot constitute linear
spaces; by including the mode 0 into the intrinsically capacitive mode set and
the intrinsically inductive mode set, these two modal sets become linear spaces
respectively, but other kinds of capacitive modes and inductive modes cannot
constitute linear spaces.",1804.09246v1
2019-10-01,Weak signal enhancement by non-linear resonance control in a forced nano-electromechanical resonator,"Driven non-linear resonators can display sharp resonances or even multistable
behaviours amenable to induce strong enhancements of weak signals. Such
enhancements can make use of the phenomenon of vibrational resonance whereby a
weak low-frequency signal applied to a bistable resonator can be amplified by
driving the non-linear oscillator with another appropriately-adjusted
non-resonant high-frequency field. Here we demonstrate the resonant enhancement
of a weak signal by use of a vibrational force yet in a monostable system
consisting of a driven nano-electromechanical nonlinear resonator. The
oscillator is subjected to a strong quasi-resonant drive and to two additional
tones: a weak signal at lower frequency and a non-resonant driving at an
intermediate frequency. We show experimentally and theoretically a significant
enhancement of the weak signal thanks to the occurence of vibrational resonance
enabled by the presence of the intermediate frequency driving. We analyse this
phenomenon in terms of coherent nonlinear resonance manipulation. Our results
illustrate a general mechanism which may have applications in the fields of
radio-frequency signal processing or sensing for instance.",1910.04686v1
2019-10-13,Tunable High-Quality Fano Resonance in Coupled Terahertz Whispering-Gallery-Mode Resonators,"Fano resonance is widely discussed in designing novel terahertz components,
such as sensors, filters, modulators, and group delay modules. Usually, high
quality (Q) factor and flexible tunability of Fano resonance are key
requirements for these applications. Here, we present tunable terahertz Fano
resonance with a Q factor of 2095 at 0.439 THz in coupled terahertz
whispering-gallery-mode resonators (WGMRs). Coupling between a relatively low Q
(578) quartz ring and a high Q (2095) silicon ring is employed to generate the
Fano resonance. The resonant frequency of the Fano resonance can be actively
manipulated by tuning the resonant frequency of the high Q WGMR, which is
achieved through utilizing an electrical thermo-optic tuning method, meanwhile,
the resonance intensity of the Fano resonance can be engineered by adjusting
the coupling strength between two WGMRs. This coupled-WGMR scheme delivers high
Q tunable Fano resonance and may contribute to the design of high-performance
configurable terahertz devices.",1910.05716v1
2023-02-15,Non-perturbative investigation of low eccentricity exterior mean motion resonances,"Mean motion resonances are important in the analysis and understanding of the
dynamics of planetary systems. While perturbative approaches have been dominant
in many previous studies, recent non-perturbative approaches have revealed
novel properties in the low eccentricity regime for interior mean motion
resonances of Jupiter in the fundamental model of the circular planar
restricted three body model. Here we extend the non-perturbative investigation
to exterior mean motion resonances in the low eccentricity regime (up to about
0.1) and for perturber mass in the range 5e-5 to 1e-3 (in units of the central
mass). Our results demonstrate that first order exterior resonances have two
branches at low eccentricity as well as low-eccentricity bridges connecting
neighboring first order resonances. With increasing perturber mass, higher
order resonances dissolve into chaos whereas low order resonances persist with
larger widths in their radial extent but smaller azimuthal widths. For low
order resonances, we also detect secondary resonances arising from small
integer commensurabilities between resonant librations and the synodic
frequency. These secondary resonances contribute significantly to generating
the chaotic sea that typically occurs near mean motion resonances of
higher-mass perturbers.",2302.07900v1
2005-06-20,New broad 8Be nuclear resonances,"Energies, total and partial widths, and reduced width amplitudes of 8Be
resonances up to an excitation energy of 26 MeV are extracted from a coupled
channel analysis of experimental data. The presence of an extremely broad J^pi
= 2^+ ``intruder'' resonance is confirmed, while a new 1^+ and very broad 4^+
resonance are discovered. A previously known 22 MeV 2^+ resonance is likely
resolved into two resonances. The experimental J^pi T = 3^(+)? resonance at 22
MeV is determined to be 3^-0, and the experimental 1^-? (at 19 MeV) and 4^-?
resonances to be isospin 0.",0506063v2
2012-02-14,Simultaneous radiation pressure induced heating and cooling of an opto-mechanical resonator,"Cavity opto-mechanics enabled radiation-pressure coupling between optical and
mechanical modes of a micro-mechanical resonator gives rise to dynamical
backaction, enabling amplification and cooling of mechanical motion. Due to a
combination of large mechanical oscillations and necessary saturation of
amplification, the noise floor of the opto-mechanical resonator increases,
rendering it ineffective at transducing small signals, and thereby cooling
another mechanical resonance of the system. Here we show amplification of one
mechanical resonance in a micro-mechanical ring resonator while simultaneously
cooling another mechanical resonance by exploiting two closely spaced optical
whispering gallery mode cavity resonances.",1202.3154v1
2012-02-25,Anisotropy-induced Fano resonance,"An optical Fano resonance, which is caused by birefringence control rather
than frequency selection, is discovered. Such birefringence-induced Fano
resonance comes with fast-switching radiation. The resonance condition
$\varepsilon_t< 1/\varepsilon_r$ is revealed and a tiny perturbation in
birefringence is found to result in a giant switch in the principal light pole
induced near surface plasmon resonance. The loss and size effects upon the Fano
resonance have been studied Fano resonance is still pronounced, even if the
loss and size of the object increase. The evolutions of the radiation patterns
and energy singularities illustrate clearly the sensitive dependence of Fano
resonance upon the birefringence.",1202.5613v1
2013-10-14,Localized and complete resonance in plasmonic structures,"This paper studies a possible connection between the way the time averaged
electromagnetic power dissipated into heat blows up and the anomalous localized
resonance in plasmonic structures. We show that there is a setting in which the
localized resonance takes place whenever the resonance does and moreover, the
power is always bounded and might go to $0$. We also provide another setting in
which the resonance is complete and the power goes to infinity whenever
resonance occurs; as a consequence of this fact there is no localized
resonance. This work is motivated from recent works on cloaking via anomalous
localized resonance.",1310.3633v2
2016-10-06,Analytic Solution of the Electromagnetic Eigenvalues Problem in a Cylindrical Resonator,"Resonant accelerating cavities are key components in modern particles
accelerating facilities. These take advantage of electromagnetic fields
resonating at microwave frequencies to accelerate charged particles. Particles
gain finite energy at each passage through a cavity if in phase with the
resonating field, reaching energies even of the order of $TeV$ when a cascade
of accelerating resonators are present. In order to understand how a resonant
accelerating cavity transfers energy to charged particles, it is important to
determine how the electromagnetic modes are exited into such resonators. In
this paper we present a complete analytical calculation of the resonating
fields for a simple cylindrical-shaped cavity.",1610.02083v1
2020-01-14,Close-to-touching acoustic subwavelength resonators: eigenfrequency separation and gradient blow-up,"In this paper, we study the behaviour of the coupled subwavelength resonant
modes when two high-contrast acoustic resonators are brought close together. We
consider the case of spherical resonators and use bispherical coordinates to
derive explicit representations for the capacitance coefficients which, we
show, capture the system's resonant behaviour at leading order. We prove that
the pair of resonators has two subwavelength resonant modes whose frequencies
have different leading-order asymptotic behaviour. We, also, derive estimates
for the rate at which the gradient of the scattered pressure wave blows up as
the resonators are brought together.",2001.04888v2
2021-08-03,"Resonances in finitely perturbed quantum walks, resonance expansion and generic simplicity","We define resonances for finitely perturbed quantum walks as poles of the
scattering matrix in the lower half plane. We show a resonance expansion which
describes the time evolution in terms of resonances and corresponding Jordan
chains. In particular, the decay rate of the survival probability is given by
the imaginary part of resonances and the multiplicity. We prove generic
simplicity of the resonances, although there are quantum walks with multiple
resonances.",2108.01345v1
2007-07-29,Resonance sticking in the scattered disk,"We investigate the dynamical evolution of trans-Neptunian objects (TNOs) in
typical scattered disk orbits (scattered TNOs) by performing simulations using
several thousand particles lying initially on Neptune-encountering orbits. We
explore the role of resonance sticking in the scattered disk, a phenomenon
characterized by multiple temporary resonance captures ('resonances' refers to
external mean motion resonances with Neptune, which can be described in the
form r:s, where the arguments r and s are integers). First, all scattered TNOs
evolve through intermittent temporary resonance capture events and
gravitational scattering by Neptune. Each scattered TNO experiences tens to
hundreds of resonance captures over a period of 4 Gyr, which represents about
38% of the object's lifetime (mean value). Second, resonance sticking plays an
important role at semimajor axes a < 250 AU, where the great majority of such
captures occurred. It is noteworthy that the stickiest (i.e., dominant)
resonances in the scattered disk are located within this distance range and are
those possessing the lowest argument s. This was evinced by r:1, r:2 and r:3
resonances, which played the greatest role during resonance sticking evolution,
often leading to captures in several of their neighboring resonances. Finally,
the timescales and likelihood of temporary resonance captures are roughly
proportional to resonance strength. The dominance of low s resonances is also
related to the latter. In sum, resonance sticking has an important impact on
the evolution of scattered TNOs, contributing significantly to the longevity of
these objects.",0707.4301v2
2020-07-03,Method to Determine the Closed-Loop Precision of Resonant Sensors from Open-Loop Measurements,"Resonant sensors determine a sensed parameter by measuring the resonance
frequency of a resonator. For fast continuous sensing, it is desirable to
operate resonant sensors in a closed-loop configuration, where a feedback loop
ensures that the resonator is always actuated near its resonance frequency, so
that the precision is maximized even in the presence of drifts or fluctuations
of the resonance frequency. However, in a closed-loop configuration, the
precision is not only determined by the resonator itself, but also by the
feedback loop, even if the feedback circuit is noiseless. Therefore, to
characterize the intrinsic precision of resonant sensors, the open-loop
configuration is often employed. To link these measurements to the actual
closed-loop performance of the resonator, it is desirable to have a relation
that determines the closed-loop precision of the resonator from open-loop
characterisation data. In this work, we present a methodology to estimate the
closed-loop resonant sensor precision by relying only on an open-loop
characterization of the resonator. The procedure is beneficial for fast
performance estimation and benchmarking of resonant sensors, because it does
not require actual closed-loop sensor operation, thus being independent on the
particular implementation of the feedback loop. We validate the methodology
experimentally by determining the closed-loop precision of a mechanical
resonator from an open-loop measurement and comparing this to an actual
closed-loop measurement.",2007.01706v3
2020-04-01,Development of planar microstrip resonators for electron spin resonance spectroscopy,"This work focuses on the development of planar microwave resonators which are
to be used in electron spin resonance spectroscopic studies. Two half
wavelength microstrip resonators of different geometrical shapes, namely
straight ribbon and omega, are fabricated on commercially available copper clad
microwave laminates. Both resonators have a characteristic impedance of 50
{\Omega}. We have performed electromagnetic field simulations for the two
microstrip resonators and have extracted practical design parameters which were
used for fabrication. The effect of the geometry of the resonators on the
quasi-transverse electromagnetic (quasi-TEM) modes of the resonators is noted
from simulation results. The fabrication is done using optical lithography
technique in which laser printed photomasks are used. This rapid prototyping
technique allows us to fabricate resonators in a few hours with accuracy up to
6 mils. The resonators are characterized using a Vector Network Analyzer. The
fabricated resonators are used to standardize a home built low-temperature
continuous wave electron spin resonance (CW-ESR) spectrometer which operates in
S-band, by capturing the absorption spectrum of the free radical DPPH, at both
room temperature and 77 K. The measured value of g-factor using our resonators
is consistent with the values reported in literature. The designed half
wavelength planar resonators will be eventually used in setting up a pulsed
electron spin resonance spectrometer by suitably modifying the CW-ESR
spectrometer.",2004.00457v1
2017-05-23,Asymptotics of resonances for 1d Stark operators,"We consider the Stark operator perturbed by a compactly supported potentials
on the real line. We determine forbidden domain for resonances, asymptotics of
resonances at high energy and asymptotics of the resonance counting function
for large radius.",1705.08072v1
2018-12-21,Structure of resonances in a simple quantum-mechanical model,"We study the structure of resonances derived from the solution of an exactly
solvable Lippmann-Schwinger equation. Within this framework, we discuss the
concept of ""resonance form factors"", and the description of the resonant
amplitudes in terms of effective energy-dependent potentials.",1812.09003v1
2021-11-17,New results on orbital resonances,"Perturbative analyses of planetary resonances commonly predict singularities
and/or divergences of resonance widths at very low and very high
eccentricities. We have recently re-examined the nature of these divergences
using non-perturbative numerical analyses, making use of Poincar\'e sections
but from a different perspective relative to previous implementations of this
method. This perspective reveals fine structure of resonances which otherwise
remains hidden in conventional approaches, including analytical,
semi-analytical and numerical-averaging approaches based on the critical
resonant angle. At low eccentricity, first order resonances do not have
diverging widths but have two asymmetric branches leading away from the nominal
resonance location. A sequence of structures called ``low-eccentricity resonant
bridges"" connecting neighboring resonances is revealed. At planet-grazing
eccentricity, the true resonance width is non-divergent. At higher
eccentricities, the new results reveal hitherto unknown resonant structures and
show that these parameter regions have a loss of some -- though not necessarily
entire -- resonance libration zones to chaos. The chaos at high eccentricities
was previously attributed to the overlap of neighboring resonances. The new
results reveal the additional role of bifurcations and co-existence of
phase-shifted resonance zones at higher eccentricities. By employing a
geometric point of view, we relate the high eccentricity phase space structures
and their transitions to the shapes of resonant orbits in the rotating frame.
We outline some directions for future research to advance understanding of the
dynamics of mean motion resonances.",2111.09289v1
2013-12-17,Virial expansion of a harmonically trapped Fermi gas across a narrow Feshbach resonance,"We theoretically investigate the high-temperature thermodynamics of a
harmonically trapped Fermi gas across a narrow Feshbach resonance, by using the
second-order quantum virial expansion, and point out some new features compared
to the broad resonance. The interatomic interaction is modeled by the
pseudopotential with an additional parameter, i.e., the effective range, to
characterize the narrow resonance width. Deeply inside the width of a narrow
Feshbach resonance, we find the second virial coefficient evolves with the
effective range from the well-known universal value 1/4 in the broad-resonance
limit to one another value 1/2 in the narrow-resonance limit. This means the
Fermi gas is more strongly interacted at the narrow resonance. In addition, far
beyond the resonance width, we find the harmonically trapped Fermi gas still
manifests appreciable interaction effect across a narrow Feshbach resonance,
which is contrary to our knowledge of the broad Feshbach resonance. All our
results can be directly tested in current narrow Feshbach resonance
experiments, which are generally carried out in a harmonic trap.",1312.4662v1
2015-11-18,Fano resonance scattering in waveguide with an impedance boundary condition,"Sound propagation in a waveguide lined with one section of locally reactive
material is studied by resonance scattering approach. The objective is to
understand the effects of mode coupling in the lined section on the
transmission. It is shown that a transmission zero is present in the vicinity
of a resonance peak when a numerically real resonance frequency of the open
lined section (opened to infinities through the rigid parts of the waveguide)
is crossed. The transmission zero and immediate resonance peak form a Fano
resonance, it has been explained as an interaction between a resonance and the
non-resonant background. The real resonance frequency and its corresponding
trapped mode are formed by the interferences (couplings) between two neighbor
modes with complex resonance frequencies. It is also linked to the avoided
crossing of eigenvalues and the exceptional point. The scattering matrix is
expressed in terms of a matrix $\mathsf{H_{eff}}$ which describes approximately
the complex resonances in the open lined section. With the aid of the
eigenvalues and eigenfunctions of matrix $\mathsf{H_{eff}}$, the traditional
acoustic resonance scattering formula can be extended to describe the coupling
effects between the open lined section and the rigid parts of the waveguide.",1511.05588v1
2018-11-07,Quantitative modeling of superconducting planar resonators with improved field homogeneity for electron spin resonance,"We present three designs for planar superconducting microwave resonators for
electron spin resonance (ESR) experiments. We implement finite element
simulations to calculate the resonance frequency and quality factors as well as
the three-dimensional microwave magnetic field distribution of the resonators.
One particular resonator design offers an increased homogeneity of the
microwave magnetic field while the other two show a better confinement of the
mode volume. We extend our model simulations to calculate the collective
coupling rate between a spin ensemble and a microwave resonator in the presence
of an inhomogeneous magnetic resonator field. Continuous-wave ESR experiments
of phosphorus donors in $^\mathrm{nat}$Si demonstrate the feasibility of our
resonators for magnetic resonance experiments. We extract the collective
coupling rate and find a good agreement with our simulation results,
corroborating our model approach. Finally, we discuss specific application
cases for the different resonator designs.",1811.02971v2
2019-09-11,Tunable group delay in a doubly resonant metasurface composed of two dissimilar split-ring resonators,"We develop a method to control the group delay of electromagnetic waves
continuously using a doubly resonant metasurface. The method is based on the
dependences of i) the group velocity in a medium featuring two resonance lines
on the resonance linewidths and ii) the resonance linewidth of a metasurface
composed of split-ring resonators on an incidence angle of electromagnetic
wave. To verify this method for group-delay control, we design a terahertz
metasurface composed of two split-ring resonators with different resonance
frequencies and numerically analyze the transmission characteristic of the
metasurface. Double resonance lines are observed for oblique incidence and the
resonance transmission dips become deeper and broader with increasing the
incidence angle. The group delay at around the center frequency of the double
resonance lines is found to vary in the range about from 0s to 20 times the
period of the incident wave with the incidence angle. In contrast with a
previously reported method for variable control of group delay using
electromagnetically-induced-transparency-like metamaterials, a high
transmittance is achieved for a small group delay condition.",1909.04833v1
2019-12-10,Three dimensional structure of mean motion resonances beyond Neptune,"We propose a semianalytical method for the calculation of widths, libration
centers and small amplitude libration periods of the mean motion resonances
k_p:k in the framework of the circular restricted three body problem valid for
arbitrary eccentricities and inclinations. Applying the model to the trans
Neptunian region (TNR) we obtain several atlas of resonances between 30 and 100
au showing their domain in the plane (a,e) for different orbital inclinations.
The resonance width may change substantially when varying the argument of the
perihelion of the resonant object and in order to take into account these
variations we introduce the concept of resonance fragility. Resonances 1:k and
2:k are the widest, strongest, most isolated ones and with lower fragility for
all interval of inclinations and eccentricities. We discuss about the existence
of high k_p:k resonances. We analyze the distribution of the resonant
populations inside resonances 1:1, 2:3, 3:5, 4:7, 1:2 and 2:5. We found that
the populations are in general located near the regions of the space (e,i)
where the resonances are wider and less fragile with the notable exception of
the population inside the resonance 4:7 and in a lesser extent the population
inside 3:5 which are shifted to lower eccentricities.",1912.04676v1
2021-10-25,Resonance order-dependent plasmon-induced transparency in orthogonally-arranged nanoscale cavities,"In this study, we investigate plasmon-induced transparency (PIT) in a
resonator structure consisting of two orthogonally-arranged
metal-insulator-metal (MIM) nanocavities with the aim of spectral modulation of
a specific resonant order of the resonator. Our FDTD simulations demonstrate
that when both cavities in this structure resonate at the same frequency, the
PIT effect can be used to induce spectral modulation. This spectral modulation
depends on the resonance order of the cavity coupled directly to the external
field, occurring when first-order resonance is exhibited, but not with
second-order resonance. We confirmed that this behavior is caused by the
discrepancies between odd-order and even-order resonances using classical
mechanical models analogous to the nanocavities. By tuning the resonance
frequency and resonance order of the cavities, one can modulate the spectrum of
the resonator structure in an order-selective manner.",2110.12619v1
1998-11-03,"Microwave Emission by Dust: Mechanisms, Properties and Prospects for ISM Studies","I review my work with Bruce Draine on dust emissivity at microwave
frequencies (3 cm - 3 mm). This emissivity explains the recently detected
""anomalous"" component of the galactic foreground emission. Both small (a<0.001
micron) and large grains contribute to this emission. Small grains have
electric dipole moments and emit while they rotate; the microwave emission of
large grains is mostly due to magneto-dipole radiation. Most efficient
magneto-dipole emitters are strongly magnetic, e.g. ferrimagnetic or
ferromagnetic, materials. The relative role of the two mechanisms can be
established through observations of microwave emissivity from dark clouds. New
microwave window is a window of opportunity for interstellar studies. Magnetic
fields inside dark clouds may be successfully studied via microwave
polarization. Microwave emissivity constrains the abundance of strongly
magnetic materials. For instance, the available data at 90 GHz indicate that
not more than 5% of interstellar Fe is in the form of metallic iron grains or
inclusions (e.g., in ``GEMS''). Future missions, e.g. MAP and PLANCK, will
bring a wealth of microwave data that can be successfully used to study ISM.
Such a study would be appreciated by cosmologists who franticly try to remove
all foregrounds from their data.",9811043v1
1996-11-21,Blume-Emery-Griffiths model on the square lattice with repulsive biquadratic coupling,"Using a real-space renormalization group procedure with no adjustable
parameters, we investigate the Blume-Emery-Griffiths model on the square
lattice. The formalism respects sublattice symmetry, allowing the study of both
signs of K, the biquadratic exchange coupling. Our results for K>0 are compared
with other renormalization group calculations and with exact results, in order
to assess the magnitude of the errors introduced by our approximate
calculation. The quantitative agreement is excellent; values for critical
parameters differ, in some cases, by less than 1% from exact ones. For K<0, our
results lead to a rich phase diagram, with antiquadrupolar and ferromagnetic
ordered phases. Contrarily to Monte Carlo simulations, these two phases meet
only at zero temperature. Both antiquadrupolar-disordered and
ferromagnetic-disordered transitions are found to be continuous and no
ferrimagnetic phase is found.",9611159v1
1997-02-05,Phase diagrams of the S=1/2 quantum antiferromagnetic XY model on the triangular lattice in magnetic fields,"We study the S=1/2 quantum antiferromagnetic XY model on finite triangular
lattices with N sites in both longitudinal and transverse magnetic fields. We
calculate physical quantities in the ground state using a diagonalization for
spins $N \leq 27$, and those at finite temperatures using a quantum transfer
Monte Carlo method for $N \leq 24$. In the longitudinal magnetic field, the
long-range chiral order parameter seems to have a finite, nonzero value at low
temperatures suggesting the occurrence of a classical umbrella-type phase. In
the transverse magnetic field, the 1/3-plateau of the magnetization curve
appears even at low temperatures, in contrast with the classical model. The
magnetic field dependences of the order parameters suggest that the
chiral-ordered, the ferrimagnetic, and the spin flop phases appear successively
as the magnetic field is increased. The transition temperatures are estimated
from the peak position of the specific heat, and the phase diagrams are
predicted in both longitudinal and transverse magnetic fields.",9702046v1
1997-10-30,Elementary Excitations of Heisenberg Ferrimagnetic Spin Chains,"We numerically investigate elementary excitations of the Heisenberg
alternating-spin chains with two kinds of spins 1 and 1/2 antiferromagnetically
coupled to each other. Employing a recently developed efficient Monte Carlo
technique as well as an exact diagonalization method, we verify the spin-wave
argument that the model exhibits two distinct excitations from the ground state
which are gapless and gapped. The gapless branch shows a quadratic dispersion
in the small-momentum region, which is of ferromagnetic type. With the
intention of elucidating the physical mechanism of both excitations, we make a
perturbation approach from the decoupled-dimer limit. The gapless branch is
directly related to spin 1's, while the gapped branch originates from
cooperation of the two kinds of spins.",9710332v1
1998-09-02,One-dimensional Ising model with long-range and random short-range interactions,"The one-dimensional Ising model in an external magnetic field with uniform
long-range interactions and random short-range interactions satisfying bimodal
annealed distributions is studied. This generalizes the random model discussed
by Paladin et al. (J. Phys. I France 4, 1994, p. 1597). Exact results are
obtained for the thermodynamic functions at arbitrary temperatures, and special
attention is given to the induced and spontaneous magnetization. At low
temperatures the system can exist in a ``ferrimagnetic'' phase with
magnetization 0<m<1, in addition to the usual paramagnetic, ferromagnetic and
antiferromagnetic phases. For a fixed distribution of the random variables the
system presents up to three tricritical points for different intensities of the
long-range interactions. Field-temperature diagrams can present up to four
critical points.",9809050v1
1999-04-14,Magnetic clusters formation in Li_{1-x}Ni_{1+x}O_2 compounds : experiments and numerical simulations,"The magnetic properties of Li_{1-x}Ni_{1+x}O_2 compounds with x ranging
between 0.02 and 0.2 are investigated. Magnetization and ac susceptibility
measured at temperatures between 2 K and 300 K reveal a high sensitivity to x,
the excess Nickel concentration. We introduce a percolation model describing
the formation of Ni clusters and use an Ising model to simulate their magnetic
properties. Numerical results, obtained by a Monte-Carlo technique, are
compared to the experimental data. We show the existence of a critical
concentration, x_c = 0.136, locating the Ni percolation threshold. The system
is superparamagnetic for x<x_c, while it is ferrimagnetic for x>x_c. The 180
Ni-O-Ni inter-plane super-exchange coupling J_\perp \simeq -110K is confirmed
to be the predominant magnetic interaction. From the low temperature behavior,
we find a clear indication of a 90 Ni-O-Ni intra-plane antiferromagnetic
interaction $J_\parallel \simeq -1.5K$ which implies magnetic frustration.",9904194v1
1999-12-09,Ab initio study of magnetic structure and chemical reactivity of Cr2O3 and its (0001) surface,"We present the first ab initio density functional theory study of the
oxygen-terminated Cr2O3 (0001) surface within the local spin-density
approximation (LSDA). We find that spin plays a critical role for even the most
basic properties of Cr2O3 such as the structure and mechanical response of the
bulk material. The surface exhibits strong relaxations and changes in
electronic and magnetic structure with important implications for the chemical
reactivity and unusual spin-dependent catalytic activity of the surface. Unlike
the bulk, the outermost chromium bilayer is ferromagnetically ordered, and the
surface oxygen layer exhibits appreciable net spin polarization in the opposite
sense. Surprisingly, despite this ferrimagnetic order, the chemically important
states near the Fermi level exhibit ferromagnetic order and thus favor
electronic spin alignment of species interacting with the surface. Finally, we
also find a high density of unoccupied electronic surface states available to
participate in the chemical reactivity of the surface.",9912154v1
2000-01-27,Epitaxy and magnetotransport of Sr_2FeMoO_6 thin films,"By pulsed-laser deposition epitaxial thin films of Sr_2FeMoO_6 have been pre-
pared on (100) SrTiO_3 substrates. Already for a deposition temperature of 320
C epitaxial growth is achieved. Depending on deposition parameters the films
show metallic or semiconducting behavior. At high (low) deposition temperature
the Fe,Mo sublattice has a rock-salt (random) structure. The metallic samples
have a large negative magnetoresistance which peaks at the Curie temperature.
The magnetic moment was determined to 4 mu_B per formula unit (f.u.), in
agreement with the expected value for an ideal ferrimagnetic arrangement. We
found an ordinary Hall coefficient of -6.01x10^{-10} m^3/As at 300 K,
corresponding to an electronlike charge-carrier density of 1.3 per Fe,Mo-pair.
In the semiconducting films the magnetic moment is reduced to 1 mu_B/f.u. due
to disorder in the Fe,Mo sublattice. In low fields an anomalous holelike
contribution dominates the Hall voltage, which vanishes at low temperatures for
the metallic films only.",0001398v1
2000-04-18,"Metallic and nonmetallic double perovskites: A case study of A$_2$FeReO$_6$ (A= Ca, Sr, Ba)","We have investigated the structure and electronic properties of ferrimagnetic
double perovskites, A2FeReO6 (A= Ca, Sr, Ba). The A=Ba phase is cubic (Fm3m)
and metallic, while the A=Ca phase is monoclinic (P21/n) and nonmetallic.
  57Fe Mossbauer spectroscopy shows that iron is present mainly in the
high-spin (S=5/2) Fe3+ state in the Ca compound, while it occurs in an
intermediate state between high-spin Fe2+ and Fe3+ in the Ba compound. It is
argued that a direct Re t2g - Re t2g interaction is the main cause for the
metallic character of the Ba compound; the high covalency of Ca-O bonds and the
monoclinic distortion (which lifts the degeneracy of t2g states) seem to
disrupt the Re-Re interaction in the case of the Ca compound, making it
non-metallic for the same electron count.",0004315v1
2000-07-07,Dimerization of Ferrimagnets on Chains and Square Lattices,"A linear spin wave analysis of dimerization of alternating Heisenberg system
with spins $s_{1}$ and $s_{2}$ on linear chain as well as square lattice is
presented. Among the several possible dimerized configurations considered in
two dimensions the plaquette configuration is found to be energetically the
most favored one. Inclusion of a variable nearest neighbor exchange coupling
$J(a)=\frac{J}{a}$ leads to a uniform power law behavior: that is to say, the
same $\delta $-dependence is found (i) in chains as well as in square lattices;
(ii) in systems consisting of different pairs of spins $s_{1}$ and $s_{2}$;
(iii) for the magnetic energy gain, the energy gap, the energy of the gapped
magnetic excitation mode as well as for the sublattice magnetization; (iv) for
all the configurations of the square lattice; and (v) in the entire range of
$\delta :$ $(0\leq \delta <1)$. The variable exchange coupling also allows \
the energy of the gapped excitation spectrum to be $\delta $-dependent even in
the linear spin wave theory.",0007133v1
2000-10-27,Coexistent quantum and classical aspects of magnetization plateaux in alternating-spin chains,"Magnetization process of ferrimagnetic Heisenberg chains of alternating spins
are theoretically studied. The size scaling analysis with the exact
diagonalization of finite systems for ($S$,$s$)=(3/2,1) and (2,1) indicates a
multi-plateau structure in the ground-state magnetization curve for $S$ and $s$
$>1/2$. The first plateau at the spontaneous magnetization can be explained by
a classical origin, that is the Ising gap. In contrast, the second or higher
one must be originated to the quantization of the magnetization. It is also
found that all the $2s$ plateaux, including the classical and quantum ones,
appear even in the isotropic case with no bond alternation.",0010446v1
2000-10-29,Theory of Ferromagnetism in Diluted Magnetic Semiconductors,"Carrier-induced ferromagnetism has been observed in several (III,Mn)V
semiconductors. We review the theoretical picture of these ferromagnetic
semiconductors that emerges from a model with kinetic-exchange coupling between
localized Mn spins and valence-band carriers. We discuss the applicability of
this model, the validity of a mean-field approximation for its interaction term
widely used in the literature, and validity limits for the simpler RKKY model
in which only Mn spins appear explicitly. Our conclusions are based in part on
our analysis of the dependence of the system's elementary spin excitations on
carrier density and exchange-coupling strength. The analogy between this system
and spin-model ferrimagnets is explored. Finally, we list several extensions of
this model that can be important in realistic modeling of specific materials.",0010471v1
2000-12-12,Low Energy Properties of Ferrimagnetic 2-leg Ladders: a Lanczos study,"We apply the Lanczos method to a 2-leg ladder with mixed spins of magnitudes
$(S_1,S_2)=(1,1/2)$ located at alternating positions along the ladder. The
effect of dimerization $\gamma$ is also considered according to two different
patterns. A Spin Wave Theory (SWT) is applied to this model predicting one
gapless branch with ferromagnetic properties and another gapful branch with
antiferromagnetic nature as low energy excitations of the model. We compute the
ground state energies, Ferro- and AF-excitation gaps, magnetizations and
correlation functions as a function of $J'$ and $\gamma$ which results into a
fine estimate of the phase diagram. The Lanczos results are compared with the
SWT analysis and a qualitative agreement is found but with numerical
discrepancies. We also study numerically the Spin-Peierls instability and find
that it is conditional for any value of $ J' \in (0, 2)$ and both dimerization
patterns.",0012209v1
2000-12-15,Alternating-Spin Ladders in a Magnetic Field: New Magnetization Plateaux,"We study numerically the formation of magnetization plateaux with the Lanczos
method in 2-leg ladders with mixed spins of magnitudes $(S_1,S_2)=(1,1/2)$
located at alternating positions along the ladder and with dimerization
$\gamma$. For interchain coupling $J'>0$ and $\gamma=0$, we find normalized
plateaux at $m=1/3$ starting at zero field and $m=1$ (saturation), while when
$\gamma \ne 0$ is columnar, another extra plateau at $m=2/3$ shows up. For
$J'<0$, when $\gamma<\gamma_c(J')$ we find no plateau while for
$\gamma>\gamma_c(J')$ we find four plateaux at $m=0,1/3,2/3,1$. We also apply
several approximate analytical methods (Spin Wave Theory, Low-Energy Effective
Hamiltonians and Bosonization) to understand these findings and to conjeture
the behaviour of ferrimagnetic ladders with a bigger number of legs.",0012278v1
2001-06-12,Glauber slow dynamics of the magnetization in a molecular Ising chain,"The slow dynamics (10^-6 s - 10^4 s) of the magnetization in the paramagnetic
phase, predicted by Glauber for 1d Ising ferromagnets, has been observed with
ac susceptibility and SQUID magnetometry measurements in a molecular chain
comprising alternating Co{2+} spins and organic radical spins strongly
antiferromagnetically coupled. An Arrhenius behavior with activation energy
Delta=152 K has been observed for ten decades of relaxation time and found to
be consistent with the Glauber model. We have extended this model to take into
account the ferrimagnetic nature of the chain as well as its helicoidal
structure.",0106224v2
2001-10-23,Effect of local Coulomb interactions on the electronic structure and exchange interactions in Mn12 magnetic molecules,"We have studied the effect of local Coulomb interactions on the electronic
structure of the molecular magnet Mn12-acetate within the LDA+U approach. The
account of the on-site repulsion results in a finite energy gap and an integer
value of the molecule's magnetic moment, both quantities being in a good
agreement with the experimental results. The resulting magnetic moments and
charge states of non-equivalent manganese ions agree very well with
experiments. The calculated values of the intramolecular exchange parameters
depend on the molecule's spin configuration, differing by 25-30% between the
ferrimagnetic ground state and the completely ferromagnetic configurations. The
values of the ground-state exchange coupling parameters are in reasonable
agreement with the recent data on the magnetization jumps in megagauss magnetic
fields. Simple estimates show that the obtained exchange parameters can be
applied, at least qualitatively, to the description of the spin excitations in
Mn12-acetate.",0110488v1
2001-11-12,On the ground states of an array of magnetic dots in the vortex state and subject to a normal magnetic field,"Dipole-dipole interactions in a square planar array of sub-micron magnetic
disks (magnetic dots) have been studied theoretically. Under a normal magnetic
field the ground-state of the array undergoes many structural transitions
between the limiting chessboard antiferromagnetic state at zero field and the
ferromagnet at a threshold field. At intermediate fields, numerous
ferrimagnetic states having mean magnetic moments between zero and that of the
ferromagnetic state are favorable energetically. The structures and energies of
a selection of states are calculated and plotted, as are the fields required to
optimally reverse the magnetic moment of a single dot within them. Approximate
formulae for the dipolar energy and anhysteretic magnetization curve are
presented.",0111225v1
2001-12-16,Magnetic phases of the mixed-spin $J_1-J_2$ Heisenberg model on a square lattice,"We study the zero-temperature phase diagram and the low-energy excitations of
a mixed-spin ($S_1>S_2$) $J_1-J_2$ Heisenberg model defined on a square lattice
by using a spin-wave analysis, the coupled cluster method, and the Lanczos
exact-diagonalization technique. As a function of the frustration parameter
$J_2/J_1$ ($ >0$), the phase diagram exhibits a quantized ferrimagnetic phase,
a canted spin phase, and a mixed-spin collinear phase. The presented results
point towards a strong disordering effect of the frustration and quantum spin
fluctuations in the vicinity of the classical spin-flop transition. In the
extreme quantum system $(S_1,S_2)=(1,{1/2})$, we find indications of a new
quantum spin state in the region $0.46< J_2/J_1<0.5$",0112295v2
2002-04-22,"Magnetic ordering, electronic structure and magnetic anisotropy energy in the high-spin Mn$_{10}$ single molecule magnet","We report the electronic structure and magnetic ordering of the single
molecule magnet [Mn$_{10}$O$_{4}$(2,2'-biphenoxide)$_{4}$Br$_{12}$]$^{4-}$
based on first-principles all-electron density-functional calculations. We find
that two of the ten core Mn atoms are coupled antiferromagnetically to the
remaining eight, resulting in a ferrimagnetic ground state with total spin
S=13. The calculated magnetic anisotropy barrier is found to be 9 K in good
agreement with experiment. The presence of the Br anions impact the electronic
structure and therefore the magnetic properties of the 10 Mn atoms. However,
the electric field due to the negative charges has no significant effect on the
magnetic anisotropy.",0204479v1
2002-09-30,Investigation of a ring single molecular magnet Mn$_6$R$_6$ in megagauss fields,"The dependence of the magnetic susceptibility on the magnetic field is
investigated for the single molecular magnet [Mn(hfac)$_2$NITPh]$_6$. The
spikes of the susceptibility detected in a magnetic field ranging from 90 T to
285 T are interpreted as a manifestation of magnetic quantum jumps under spins
reorientation from ferrimagnetic to ferromagnetic structure. The characteristic
feature of the single molecular magnet Mn$_6$ R$_6$ is a deficiency of pair
Heisenberg exchange interactions for the description of its magnetic properties
in high magnetic fields. The comparison of the experimental data with the
results of theoretical calculations allows us to prove the existence of strong
three-spin interaction in this molecular cluster and to determine the values of
exchange constants. For the calculation of the ground state spin structure the
modified Lanczos method is used.",0209670v1
2002-10-31,Magnetic Structure of Nano-Graphite Moebius Ribbon,"We consider the electronic and magnetic properties of nanographite ribbon
with zigzag edges under the periodic or Moebius boundary conditions. The zigzag
nano-graphite ribbons possess edge localized states at the Fermi level which
cause a ferrimagnetic spin polarization localized at the edge sites even in the
very weak Coulomb interaction. The imposition of the Moebius boundary condition
makes the system non-AB-bipartite lattice, and depress the spin polarization,
resulting in the formation of a magnetic domain wall. The width of the magnetic
domain depends on the Coulomb interaction and narrows with increasing U/t.",0210685v2
2002-11-25,The Kagome-staircase lattice: Magnetic ordering in Ni3V2O8 and Co3V2O8,"Ni3V2O8 and Co3V2O8 have spin-1 and spin-3/2 magnetic lattices that are a new
anisotropic variant of the Kagome net, wherein edge-sharing MO6 octahedra form
the rises and rungs of a ""Kagome staircase"". The anisotropy largely relieves
the geometric frustration, but results in rich magnetic behavior.
Characterization of the magnetization of polycrystalline samples reveals that
the compounds are ferrimagnetic in character. Heat capacity measurements show
the presence of four magnetic phase transitions below 9 K for Ni3V2O8 and two
below 11 K for Co3V2O8. Comparison to the low temperature heat capacity of
isostructural nonmagnetic Zn3V2O8 provides an estimate of the magnetic entropy
involved with the phase transitions. The results suggest that Co3V2O8 may
display magnetic transitions below 2 K.",0211572v1
2003-01-08,Ground-state phases in a system of two competing square-lattice Heisenberg antiferromagnets,"We study a two-dimensional (2D) spin-half Heisenberg model related to the
quasi 2D antiferromagnets (Ba,Sr)2Cu3O4Cl2 by means of exact diagonalization
and spin-wave theory. The model consists of two inequivalent interpenetrating
square-lattice Heisenberg antiferromagnets A and B. While the antiferromagnetic
interaction JAA within the A subsystem is strong the coupling JBB within the B
subsystem is much weaker. The coupling JAB between A and B subsystems is
competing giving rise for interesting frustration effects. In dependence of the
strength of JAB we find a collinear Neel phase, non-collinear states with zero
magnetizations as well as canted and collinear ferrimagnetic phases with
non-zero magnetizations. For not too large values of frustration JAB, which
correpond to the situation in (Ba,Sr)2Cu3O4Cl2, we have Neel ordering in both
subsystems A and B. In the classical limit these two Neel states are decoupled.
Quantum fluctuations lead to a fluctuational coupling between both subsystems
('order from disorder') and select the collinear structure. For stronger JAB we
find evidence for a novel spin state with coexisting Neel ordering in the A
subsystem and disorder in the B subsystem.",0301095v1
2003-01-10,Phase diagram of a coupled tetrahedral Heisenberg model,"The phase diagram of a coupled tetrahedral Heisenberg model is obtained. The
quantum chain has a local gauge symmetry and its eigenspectrum is obtained by
the composition of the eigenspectra of spin-1/2 XXZ chains with arbitrary
distribution of spin-3/2 impurities. The phase diagram is quite rich with an
infinite number of phases with ferromagnetic, antiferromagnetic or
ferrimagnetic order. In some cases the ground state and the low lying
eigenlevels of the model can be exactly calculated since they coincide with the
eigenlevels of the exactly integrable XXZ chain. The thermodynamical properties
of the model at low temperatures is also studied through finite-size analysis.",0301162v2
2003-02-26,Anomalous magnetotransport in (Y$_{1-x}$Gd$_{x}$)Co$_{2}$ alloys: interplay of disorder and itinerant metamagnetism,"New mechanism of magnetoresistivity in itinerant metamagnets with a
structural disorder is introduced basing on analysis of experimental results on
magnetoresistivity, susceptibility, and magnetization of structurally
disordered alloys (Y$_{1-x}$Gd$_{x}$)Co$_{2}$. In this series, YCo$_{2}$ is an
enhanced Pauli paramagnet, whereas GdCo$_{2}$ is a ferrimagnet (T$_{\rm c}$=400
K) with Gd sublattice coupled antiferromagnetically to the itinerant Co-3d
electrons. The alloys are paramagnetic for $x < 0.12$. Large positive
magnetoresistivity has been observed in the alloys with magnetic ground state
at temperatures T$<$T$_{\rm c}$. We show that this unusual feature is linked to
a combination of structural disorder and metamagnetic instability of itinerant
Co-3d electrons. This new mechanism of the magnetoresistivity is common for a
broad class of materials featuring a static magnetic disorder and itinerant
metamagnetism.",0302539v2
2003-07-21,Study of an Antiferromagnetic Sawtooth Chain with Spin-1/2 and Spin-1 sites,"We study the low-energy properties of a sawtooth chain with spin-1's at the
bases of the triangles and spin-1/2's at the vertices of the triangles. The
spins have Heisenberg antiferromagnetic interactions between nearest neighbors,
with a coupling J_2 between a spin-1 and a spin-1/2, and a coupling J_1 = 1
between two spin-1's. Analysis of the exact diagonalization data for periodic
chains containing up to N=12 unit cells shows that the ground state is a
singlet for exchange couplings up to approximately J_2 = 3.8, whereas for
larger J_2, the system exhibits a ferrimagnetic ground state characterized by a
net ferromagnetic moment per unit cell of 1/2. In the region of small
interactions J_2, the mixed spin sawtooth chain maps on to an effective
isotropic spin model representing two weakly interacting and frustrated
spin-1/2 Heisenberg chains composed of spin-1/2 sites at odd and even vertices
respectively. Finally, we study the phenomenon of a macroscopic magnetization
jump which occurs if a magnetic field is applied with a value close to the
saturation field for J_2 = 2.",0307492v1
2003-07-21,Does a surface spin-flop occur in antiferromagnetically coupled multilayers? Magnetic states and reorientation transitions in antiferromagnetic superlattices,"Equilibrium spin configurations and their stability limits have been
calculated for models of magnetic superlattices with a finite number of thin
ferromagnetic layers coupled antiferromagnetically through (non-magnetic)
spacers as Fe/Cr and Co/Ru multilayers. Depending on values of applied magnetic
field and unaxial anisotropy, the system assumes collinear(antiferromagnetic,
ferromagnetic, various ""ferrimagnetic"") phases, or spatially inhomogeneous
(symmetric spin-flop phase and asymmetric, canted and twisted, phases)via
series of field induced continuous and discontinuous transitions. Contrary to
semi-infinite systems a surface phase transition, so-called ""surface
spin-flop"", does not occur in the models with a finite number of layers. It is
shown that ""discrete jumps"" observed in some Fe/Cr superlattices and
interpreted as ""surface spin-flop"" transition are first-order ""volume""
transitions between different canted phases. Depending on the system several of
these collinear and canted phases can exist as metastable states in broad
ranges of the magnetic fields, which may cause severe hysteresis effects. The
results explain magnetization processes in recent experiments on
antiferromagnetic Fe/Cr superlattices.",0307494v1
2003-07-23,Role of surface disorder on the magnetic properties and hysteresis of nanoparticles,"We present the results of Monte Carlo simulations of a model of a single
maghemite ferrimagnetic nanoparticle including radial surface anisotropy
distinct from that in the core with the aim to clarify what is its role on the
magnetization processes at low temperatures. The low temperature equilibrium
states are analized and compared to those of a ferromagnetic particle with the
same lattice structure. We have found that the formation of hedgehog-like
structures due to increased surface anisotropy is responsible for a change in
the reversal mechanism of the particles.",0307584v1
2003-12-19,Field-Induced Disorder Point in Non-Collinear Ising Spin Chains,"We perform a theoretical study of a non-collinear Ising ferrimagnetic spin
chain inspired by the compound Co(hfac)2NITPhOMe. The basic building block of
its structure contains one Cobalt ion and one organic radical each with a spin
1/2. The exchange interaction is strongly anisotropic and the corresponding
axes of anisotropy have a period three helical structure. We introduce and
solve a model Hamiltonian for this spin chain. We show that the present
compound is very close to a so-called disorder point at which there is a
massive ground state degeneracy. We predict the equilibrium magnetization
process and discuss the impact of the degeneracy on the dynamical properties by
using arguments based on the Glauber dynamics.",0312528v1
2004-01-15,Ferrimagnetic mixed-spin ladders in weak and strong coupling limits,"We study two similar spin ladder systems with the ferromagnetic leg coupling.
First model includes two sorts of spins, s= 1/2 and s= 1, and the second model
comprises only s=1/2 legs coupled by a ""triangular"" rung exchange. The
antiferromagnetic (AF) rung coupling destroys the long-range order and
eventually makes the systems equivalent to the AF s=1/2 Heisenberg chain. We
investigate the situation by different methods in weak and strong rung coupling
limits. Particularly we compare the spin-wave theory and the bosonization
method in the weak coupling regime of the second model. We analyze the spectra
and correlations, and discuss the order parameter of these ladder systems.",0401264v2
2004-03-30,"Finite-Size effects in ""Single Chain Magnets"": an experimental and theoretical study","The problem of finite size effects in s=1/2 Ising systems showing slow
dynamics of the magnetization is investigated introducing diamagnetic
impurities in a Co$^{2+}$-radical chain. The static magnetic properties have
been measured and analyzed considering the peculiarities induced by the
ferrimagnetic character of the compound. The dynamic susceptibility shows that
an Arrhenius law is observed with the same energy barrier for the pure and the
doped compounds while the prefactor decreases, as theoretically predicted.
Multiple spins reversal has also been investigated.",0403731v1
2004-05-31,Orbital order and ferrimagnetic properties of the new compound $Sr_8 Ca Re_3 Cu_4 O_{24}$,"By means of the LSDA+U method and the Green function method, we investigate
the electronic and magnetic properties of the new material of
Sr$_8$CaRe$_3$Cu$_4$O$_{24}$. Our LSDA+U calculation shows that this system is
an insulator with a net magnetic moment of 1.01 $\mu_{\rm B}$/f.u., which is in
good agreement with the experiment. Magnetic moments are mainly located at Cu
atoms, and the magnetic moments of neighboring Cu sites align anti-parallel. It
is the non-magnetic Re atoms that induce an orbital order of $d$ electrons of
Cu atoms, which is responsible for the strong exchange interaction and the high
magnetic transition temperature. Based on the LSDA+U results, we introduce an
effective model for the spin degrees of freedom, and investigate the
finite-temperature properties by the Green function method. The obtained
results are consistent with the experimental results, indicating that the
spin-alternating Heisenberg model is suitable for this compound.",0405684v1
2004-06-11,"Electronic structures of Cr$_{1-δ}$X (X=S, Te) studied by Cr 2p soft x-ray magnetic circular dichroism","Cr 2p core excited XAS and XMCD spectra of ferromagnetic Cr$_{1-\delta}$Te
with several concentrations of $\delta$=0.11-0.33 and ferrimagnetic
Cr$_{5}$S$_{6}$ have been measured. The observed XMCD lineshapes are found to
very weakly depend on $\delta$ for Cr$_{1-\delta}$Te. The experimental results
are analyzed by means of a configuration-interaction cluster model calculation
with consideration of hybridization and electron correlation effects. The
obtained values of the spin magnetic moment by the cluster model analyses are
in agreement with the results of the band structure calculation.The calculated
result shows that the doped holes created by the Cr deficiency exist mainly in
the Te 5porbital of Cr$_{1-\delta}$Te, whereas the holes are likely to be in Cr
3d state for Cr$_{5}$S$_{6}$.",0406283v1
2004-07-01,Orbital Glass in FeCr2S4,"Low-temperature heat-capacity investigations on the spinel FeCr2S4 with
ferrimagnetic spin order and orbitally degenerated Jahn-Teller active Fe2+ ions
in a tetrahedral crystal field, provide experimental evidence of an orbital
liquid state above 10 K. We demonstrate that the low-temperature transition at
10 K arises from orbital order and is very sensitive to fine tuning of the
stoichiometry in polycrystals. In single crystals the orbital order is fully
suppressed resulting in an orbital glass state with the heat capacity following
a strict T^2 dependence as temperature approaches zero.",0407026v1
2004-12-10,Thermodynamic properties of tetrameric bond-alternating spin chains,"Thermodynamic properties of a tetrameric bond-alternating Heisenberg spin
chain with ferromagnetic-ferromagnetic-antiferromagnetic-antiferromagnetic
exchange interactions are studied using the transfer-matrix renormalization
group and compared to experimental measurements. The temperature dependence of
the uniform susceptibility exhibits typical ferrimagnetic features. Both the
uniform and staggered magnetic susceptibilities diverge in the limit $T\to 0$,
indicating that the ground state has both ferromagnetic and antiferromagnetic
long-range orders. A double-peak structure appears in the temperature
dependence of the specific heat. Our numerical calculation gives a good account
for the temperature and field dependence of the susceptibility, the
magnetization, and the specific heat for Cu(3-Clpy)$_{2}$(N$_{3}$)$_{2}$
(3-Clpy=3-Chloroyridine).",0412275v2
2004-12-29,Spin wave analysis of Heisenberg magnets in restricted geometries,"In the last decade it has been proven that the standard spin wave theory was
able to provide accurate zero-temperature results for a number of
low-dimensional Heisenberg spin systems. In this chapter we introduce the main
ingredients of the spin-wave technique using as a working model the two-leg
mixed-spin ferrimagnetic ladder and the Dyson--Maleev boson formalism up to
second order in the spin-wave interaction. In the remainder, we survey typical
applications in low-space dimensionality as well as some recent modifications
of the theory admitting a quantitative analysis in magnetically disordered
phases. The presented spin-wave results are compared with available numerical
estimates.",0412742v1
2005-02-23,Charge order in Fe2OBO3: An LSDA+U study,"Charge ordering in the low-temperature monoclinic structure of iron oxoborate
(Fe2OBO3) is investigated using the local spin density approximation (LSDA)+U
method. While the difference between t_{2g} minority occupancies of Fe^{2+} and
Fe^{3+} cations is large and gives direct evidence for charge ordering, the
static ""screening"" is so effective that the total 3d charge separation is
rather small. The occupied Fe^{2+} and Fe^{3+} cations are ordered alternately
within the chain which is infinite along the a-direction. The charge order
obtained by LSDA+U is consistent with observed enlargement of the \beta angle.
An analysis of the exchange interaction parameters demonstrates the
predominance of the interribbon exchange interactions which determine the whole
L-type ferrimagnetic spin structure.",0502555v1
2005-02-23,Enhanced magnetic moment and conductive behavior in NiFe2O4 spinel ultrathin films,"Bulk NiFe2O4 is an insulating ferrimagnet. Here, we report on the epitaxial
growth of spinel NiFe2O4 ultrathin films onto SrTiO3 single-crystals. We will
show that - under appropriate growth conditions - epitaxial stabilization leads
to the formation of a spinel phase with magnetic and electrical properties that
radically differ from those of the bulk material : an enhanced magnetic moment
(Ms) - about 250% larger - and a metallic character. A systematic study of the
thickness dependence of Ms allows to conclude that its enhanced value is due to
an anomalous distribution of the Fe and Ni cations among the A and B sites of
the spinel structure resulting from the off-equilibrium growth conditions and
to interface effects. The relevance of these findings for spinel- and, more
generally, oxide-based heterostructures is discussed. We will argue that this
novel material could be an alternative ferromagetic-metallic electrode in
magnetic tunnel junctions.",0502558v1
2005-03-26,On effects of regular S=1 dilution of S=1/2 antiferromagnetic Heisenberg chains by a quantum Monte Carlo simulation,"The effects of regular S=1 dilution of S=1/2 isotropic antiferromagnetic
chain are investigated by the quantum Monte Carlo loop/cluster algorithm. Our
numerical results show that there are two kinds of ground-state phases which
alternate with the variation of $S^1=1$ concentration. When the effective spin
of a unit cell is half-integer, the ground state is ferrimagnetic with gapless
energy spectrum and the magnetism becomes weaker with decreasing of the $S^1$
concentration $\rho = 1/M$. While it is integer, a non-magnetic ground state
with gaped spectrum emerges and the gap gradually becomes narrowed as fitted by
a relation of $\Delta \approx 1.25\sqrt{\rho}$.",0503624v3
2005-05-17,Robust Half-Metallic Character and Large Oxygen Magnetism in a Perovskite Cuprate,"The new perovskite cuprate material Sr$_{8}$CaRe$_{3}$Cu$_{4}$O$_{24}$, which
behaves ferrimagnetically and shows an unusually high Curie temperature ($T_c
\sim$ 440 K), is found from density-functional theory calculation to display
several surprising properties after hole doping or chemical substitution: (1)
Half metal (HM) is realized by replacing Re with W or Mo while $T_c$ remains
high; (2) hole-doped Sr$_{8}$CaRe$_{3}$Cu$_{4}$O$_{24}$ is also HM with high
$T_c$. Moreover, we find that the O atoms will carry a large magnetic moment
after hole doping, which is in sharp contrast with the generally accepted
concept that magnetism in solid requires partially filled shells of $d$ or $f$
electrons in cations. The material Sr$_8$CaRe$_3$Cu$_4$O$_{24}$ is therefore
expected to provide a very useful platform for material design and development.",0505408v1
2005-05-30,Spin Disorder and Magnetic Anisotropy in Fe3O4 Nanoparticles,"We have studied the magnetic behavior of dextran-coated magnetite
(Fe$_3$O$_4$) nanoparticles with median particle size $\left<d\right>=8$ $nm$.
Magnetization curves and in-field M\""ossbauer spectroscopy measurements showed
that the magnetic moment $M_S$ of the particles was much smaller than the bulk
material. However, we found no evidence of magnetic irreversibility or
non-saturating behavior at high fields, usually associated to spin canting. The
values of magnetic anisotropy $K_{eff}$ from different techniques indicate that
surface or shape contributions are negligible. It is proposed that these
particles have bulk-like ferrimagnetic structure with ordered A and B
sublattices, but nearly compensated magnetic moments. The dependence of the
blocking temperature with frequency and applied fields, $T_B(H,\omega)$,
suggests that the observed non-monotonic behavior is governed by the strength
of interparticle interactions.",0505682v5
2005-06-02,Magnetic moments of W 5d in Ca2CrWO6 and Sr2CrWO6 double perovskites,"We have investigated the magnetic moment of the W ion in the ferrimagnetic
double perovskites Sr2CrWO6 and Ca2CrWO6 by X-ray magnetic circular dichroism
(XMCD) at the W L(2,3) edges. In both compounds a finite negative spin and
positive orbital magnetic moment was detected. The experimental results are in
good agreement with band-structure calculations for (Sr/Ca)2CrWO6 using the
full-potential linear muffin-tin orbital method. It is remarkable, that the
magnetic ordering temperature, TC, is correlated with the magnetic moment at
the 'non-magnetic' W atom.",0506048v2
2005-06-16,Phase diagrams in the Blume-Emery-Griffiths Ising films,"We study the spin-1 Ising model with bilinear and biquadratic exchange
interactions and single-ion crystal field. In addition to the four usual
phases: disordered DIS, ferromagnetic FER, antiquadrupolar AQU and
ferrimagnetic FRI, we found three new phases in the case of a thin magnetic
film, namely: the sublattice A non magnetic phase NMA, the sublattice B non
magnetic phase NMB and the global non magnetic phase NMG. These phases are
studied, for each layer of the film, either in the temperature-crystal field
plane $(T,\Delta)$ or in the biquadratic coupling-crystal field plane
$(d,\Delta)$, for diferent film thicknesses. On the other hand, the thermal
behaviour of the layer quadrupolar moments $q_{A}, q_{B}$ and layer
magnetisations $m_{A}, m_{B}$ are investigated for negative values of the
biquadratic coupling and crystal field. It is also found that for fixed values
of the biquadratic coupling, the temperature and the crystal field, each layer
of the film can belong to a differnt phase. To illustrate this situation, an
example is given for $d=-3.0$, $\Delta =-3.0$ and $T=1.3$.",0506413v2
2005-07-14,Ground states of the generalized Falicov-Kimball model in one and two dimensions,"A combination of small-cluster exact-diagonalization calculations and a
well-controlled approximative method is used to study the ground-state phase
diagram of the spin-one-half Falicov-Kimball model extended by the
spin-dependent on-site interaction between localized ($f$) and itinerant ($d$)
electrons. Both the magnetic and charge ordering are analysed as functions of
the spin-dependent on-site interaction ($J$) and the total number of itinerant
($N_d$) and localized ($N_f$) electrons at selected $U$ (the spin-independent
interaction between the $f$ and $d$ electrons). It is shown that the
spin-dependent interaction (for $N_f=L$, where $L$ is the number of lattice
sites) stabilizes the ferromagnetic (F) and ferrimagnetic (FI) state, while the
stability region of the antiferromagnetic (AF) phase is gradually reduced. The
precisely opposite effect on the stability of F, FI and AF phases has a
reduction of $N_f$. Moreover, the strong coupling between the $f$ and
$d$-electron subsystems is found for both $N_f=L$ as well as $N_f < L$.",0507342v1
2005-07-15,Reentrant transitions of a mixed-spin Ising model on the diced lattice,"Magnetic behaviour of a mixed spin-1/2 and spin-1 Ising model on the diced
lattice is studied by the use of an exact star-triangle mapping transformation.
It is found that the uniaxial as well as biaxial single-ion anisotropy acting
on the spin-1 sites may potentially cause a reentrant transition with two
consecutive critical points. Contrary to this, the effect of
next-nearest-neighbour interaction between the spin-1/2 sites possibly leads to
a reentrant transition with three critical temperatures in addition to the one
with two critical points only. The shape of the total magnetization versus
temperature dependence is particularly investigated for the case of
ferrimagnetically ordered system.",0507367v2
2005-09-28,"Switching of sub-micrometer sized, antiferromagnetically coupled CoFeB/Ru/CoFeB trilayers","This work reports on the magnetic reversal of sub-micrometer sized elements
consisting of an CoFeB/Ru/CoFeB artificial ferrimagnet (AFi). The elements were
patterned into ellipses having a width of approximately 250 to 270nm and a
varying aspect ratio between 1.3 and 8. The coercivity was found to decrease
with an increasing imbalance of the magnetic moment of the two
antiferromagnetically coupled layers and is therefore strongly affected by an
increase of effective anisotropy due to the antiferromagnetic coupling of the
two layers. With respect to a single layer of amorphous CoFeB, patterned in
comparable elements, the AFi has an increased coercivity. Switching asteroids
comparable to single layers were only observed for samples with a high net
moment.",0509750v3
2006-01-17,Electron Correlations and the Minority-Spin Band Gap in Half-Metallic Heusler Alloys,"Electron-electron correlations affect the band gap of half-metallic
ferromagnets by introducing non-quasiparticle states just above the Fermi
level. In contrast to the spin-orbit coupling, a large asymmetric
non-quasiparticle spectral weight is present in the minority-spin channel,
leading to a peculiar finite-temperature spin depolarization effects. Using
recently developed first-principle dynamical mean field theory, we investigate
these effects for the half-metallic ferrimagnetic Heusler compound FeMnSb. We
discuss depolarization effects in terms of strength of local Coulomb
interaction $U$ and temperature in FeMnSb. We propose Ni$_{1-x}$Fe$_{x}$MnSb
alloys as a perspective materials to be used in spin-valve structures and for
experimental search of non-quasiparticle states in half-metallic materials.",0601376v1
2006-02-26,Strong temperature dependence of antiferromagnetic coupling in CoFeB/Ru/CoFeB,"The temperature dependence of saturation and spin-flop fields for artificial
ferrimagnets (AFi) based on antiparallel coupled CoFeB/Ru/CoFeB trilayers has
been investigated in a temperature range between 80K and 600K. The results
presented in this paper are relevant for magnetic devices using this system,
e.g. magnetic-random access memory based on spin-flop switching. In good
accordance to the theory, the saturation field Hsat behaves like Hsat ~ H_0
(T/T_0)/sinh(T/T_0) with a characteristic temperature of T_0 = 150K. Within
this model, the Fermi velocity for the Ru layer is of the order of 10^5m/s,
therefore, explaining the strong variation of the coupling strength with the
temperature in Ru based AFi. Furthermore, a strong uniaxial anisotropy of K_u =
2x10^3 J/m^3 with a small angular distribution of the anisotropy axes is
observed for the AFi trilayers based on amorphous CoFeB alloys.",0602609v2
2006-03-08,Magnetic and Electronic Properties of the New Ferrimagnet Sr8CaRe3Cu4O24,"Magnetic and electronic properties of the recently-discovered material
Sr8CaRe3Cu4O24 were investigated by means of a quantum Monte Carlo simulation,
the Green function method and the LSDA+U (local spin-density approximation plus
the Hubbard-U term) method. The LSDA+U calculation shows that the ground state
is an insulator with magnetic moment M=1.01\muB/f.u., which is consistent with
experimental results. The magnetic sites were specified and an effective model
for the magnetic properties of this compound derived. The resultant effective
model is a three-dimensional Heisenberg model with spin-alternation.
Finite-temperature properties of this effective model are investigated by the
quantum Monte Carlo method (continuous-time loop algorithm) and the Green
function method. The numerical results are consistent with experimental
results, indicating that the model is suitable for this material. Using the
analysis of the effective model, some predictions for the material are made.",0603194v1
2006-04-28,High and low-temperature crystal and magnetic structures of epsilon-Fe2O3 and their correlation to its magnetic properties,"The crystal and magnetic structures of the orthorhombic e-Fe2O3 have been
studied by simultaneous Rietveld refinement of X-ray and neutron powder
diffraction data in combination with Mossbauer spectroscopy, as well as
magnetisation and heat capacity measurements. It has been found that above 150
K the e-Fe2O3 polymorph is a collinear ferrimagnet with the magnetic moments
directed along the a axis, while the magnetic ordering below 80 K is
characterised by a square-wave incommensurate structure. The transformation
between these two states is a second order phase transition and involves subtle
structural changes mostly affecting the coordination of the tetrahedral and one
of the octahedral Fe sites. The temperature dependence of the e-Fe2O3 magnetic
properties is discussed in the light of these results.",0604677v1
2006-06-16,Unravelling the origin of the controversial magnetic properties of BiFeO3 thin films,"Single phase (001)-oriented BiFeO3 (BFO) thin films grown by pulsed laser
deposition can only be obtained in a narrow window of deposition pressure and
temperature and have a low magnetic moment. Out of the stability window Fe- or
Bi-rich impurity phases form, which has a strong impact on the physical and
structural properties of the films, even for impurity concentrations hardly
detectable by standard X-ray diffraction measurements. By using more sensitive
tools such as X-Ray absorption spectroscopy and X-ray magnetic circular
dichroism and performing advanced X-ray diffraction characterization, we show
that in non-optimal conditions Fe forms ferrimagnetic gamma-Fe2O3 precipitates
that are responsible for virtually all the ferromagnetic signal measured on
such BFO films by standard magnetometry. This confirms that the BFO phase has a
very low intrinsic moment that does not depend on strain. We also study the
influence of film thickness on the nucleation of parasitic phases and find that
epitaxial strain can stabilize the pure BFO phase in slightly over-oxidizing
growth conditions.",0606441v1
2006-06-20,Giant tunnel magnetoresistance and high annealing stability in CoFeB/MgO/CoFeB magnetic tunnel junctions with synthetic pinned layer,"We investigated the relationship between tunnel magnetoresistance (TMR) ratio
and the crystallization of CoFeB layers through annealing in magnetic tunnel
junctions (MTJs) with MgO barriers that had CoFe/Ru/CoFeB synthetic ferrimagnet
pinned layers with varying Ru spacer thickness (tRu). The TMR ratio increased
with increasing annealing temperature (Ta) and tRu, reaching 361% at Ta = 425C,
whereas the TMR ratio of the MTJs with pinned layers without Ru spacers
decreased at Ta over 325C. Ruthenium spacers play an important role in forming
an (001)-oriented bcc CoFeB pinned layer, resulting in a high TMR ratio through
annealing at high temperatures.",0606503v1
2006-07-03,A surprising relation between double exchange and Heisenberg model spectra: Application to half-doped manganites,"The Zener polarons recently found in half-doped manganites are usually seen
as mixed valence entities ruled by a double exchange Hamiltonian involving only
correlated electrons of the metals. They can however be considered as
ferrimagnetic local units if the holes are localized on the bridging oxygen
atoms as implicitely suggested by recent mean-field it ab initio calculations.
In the latter case, the physics is ruled by a Heisenberg Hamiltonian involving
magnetic oxygen bridges. This paper shows that the spectra resulting from the
resolution of both models are analytically identical. This single resulting
model spectrum accurately reproduces the spectrum of Zener polarons in
Pr0.6Ca0.4MnO3 manganite studied by means of explicitely correlated ab initio
calculations. Since the physics supported by each model are different, the
analysis of the exact Hamiltonian ground state wave function should a priori
enables one to determine the most appropriate model. It will be shown that
neither the spectrum nor the wavefunction analysis bring any decisive arguments
to settle the question. Such undecidability would probably be encountered in
experimental information.",0607048v1
2006-07-18,Magnetic properties of Fe/Dy multilayers: a Monte Carlo investigation,"We investigate the magnetic properties of a Heisenberg ferrimagnetic
multilayer by using Monte Carlo simulations. The aim of this work is to study
the local structural anisotropy model which is a possible origin of the
perpendicular magnetic anisotropy in transition metal/rare earth amorphous
multilayers. We have considered a face centered cubic lattice where each site
is occupied by a classical Heisenberg spin. We have introduced in our model of
amorphous multilayers a small fraction of crystallized Fe-Dy nanoclusters with
a mean anisotropy axis along the deposition direction. We show that a
competition in the energy terms takes place between the mean uniaxial
anisotropy of the Dy atoms in the nanoclusters and the random anisotropy of the
Dy atoms in the matrix.",0607437v1
2006-07-27,Magnetic anisotropy and geometrical frustration in the Ising spin-chain system Sr5Rh4O12,"A structural and thermodynamic study of the newly synthesized single crystal
Sr5Rh4O12 is reported. Sr5Rh4O12 consists of a triangular lattice of spin
chains running along the c-axis. It is antiferromagnetically ordered below 23 K
with the intrachain and interchain coupling being ferromagnetic (FM) and
antiferromagnetic (AFM), respectively. There is strong evidence for an Ising
character in the interaction and geometrical frustration that causes incomplete
long-range AFM order. The isothermal magnetization exhibits two step-like
transitions leading to a ferrimagnetic state at 2.4 T and a FM state at 4.8 T,
respectively. Sr5Rh4O12 is a unique frustrated spin-chain system ever found in
4d and 5d based materials without a presence of an incomplete 3d-electron
shell.",0607732v1
2006-08-17,Spatially anisotropic Heisenberg Kagome antiferromagnet,"In the search for spin-1/2 kagome antiferromagnets, the mineral volborthite
has recently been the subject of experimental studies [Hiroi et al.,2001]. It
has been suggested that the magnetic properties of this material are described
by a spin-1/2 Heisenberg model on the kagome lattice with spatially anisotropic
exchange couplings. We report on investigations of the Sp(N) symmetric
generalisation of this model in the large N limit. We obtain a detailed
description of the dependence of possible ground states on the anisotropy and
on the spin length S. A fairly rich phase diagram with a ferrimagnetic phase,
incommensurate phases with and without long range order and a decoupled chain
phase emerges.",0608393v1
2006-10-30,Spin-polarization and electronic properties of half-metallic Heusler alloys calculated from first-principles,"Half-metallic Heusler alloys are amongst the most promising materials for
future magnetoelectronic applications. We review some recent results on the
electronic properties of these compounds. The origin of the gap in these
half-metallic alloys and its connection to the magnetic properties are well
understood. Changing the lattice parameter shifts slightly the Fermi level.
Spin-orbit coupling induces states within the gap but the alloys keep a very
high degree of spin-polarization at the Fermi level. Small degrees of doping
and disorder as well as defects with low formation energy have little effect on
the properties of the gap, while temperature effects can lead to a quick loss
of half-metallicity. Finally we discuss two special issues; the case of
quaternary Heusler alloys and the half-metallic ferrimagnets.",0610827v1
2006-11-23,Quantum dissipation theory of slow magnetic relaxation mediated by domain-wall motion in one-dimensional chain compound [Mn(hfac)_{2}BNO_{H}}],"Based on a quantum dissipation theory of open systems, we present a
theoretical study of slow dynamics of magnetization for the ordered state of
the new molecule-based magnetic complex [Mn(hfac)_{2}BNO_{H}] composed from
antiferromagnetically coupled ferrimagnetic (5/2,1) spin chains. Experimental
investigations of the magnetization process in pulsed fields have shown that
this compound exhibits a metamagnetic AF-FI transition at a critical field in
the order of the interchain coupling. A strong frequency dependence for the
ac-susceptibility has been revealed in the vicinity of the AF-FI transition and
was associated with an AF-FI interface kink motion. We model these processes by
a field-driven domain-wall motion along the field-unfavorable chains correlated
with a dissipation effect due to a magnetic system-bath coupling. The
calculated longitudinal magnetization has a two-step relaxation after the field
is switched off and are found in good agreement with the experiment. The
relaxation time determined from the imaginary part of the model
ac-susceptibility agrees qualitatively with that found from the remanent
magnetization data.",0611610v1
2006-12-01,Antiferromagnetic Ising Model on Inverse Perovskite Lattice,"We study thermodynamic properties of an antiferromagnetic Ising model on the
inverse perovskite lattice by using Monte Carlo simulations. The lattice
structure is composed of corner-sharing octahedra and contains
three-dimensional geometrical frustration in terms of magnetic interactions.
The system with the nearest-neighbor interactions alone does not exhibit any
phase transition, leading to a degenerate ground state with large residual
entropy. The degeneracy is lifted by an external magnetic field or by an
anisotropy in the interactions. Depending on the anisotropy, they stabilize
either a 3D ferrimagnetic state or a partially-disordered antiferromagnetic
(PDAF) state with a dimensionality reduction to 2D. By the degeneracy-lifting
perturbations, all the transition temperatures of these different ordered
states continuously grow from zero, leaving an unusual zero-temperature
critical point at the unperturbed point. Such a zero-temperature
multicriticality is not observed in other frustrated structures such as
face-centered cubic and pyrochlore. The transition to the PDAF state is
represented by either the first- or second-order boundaries separated by
tricritical lines, whereas the PDAF phase shows 1/3 magnetization plateaus.",0612016v1
2006-12-20,Spin transitions induced by a magnetic field in quantum dot molecules,"We present a theoretical study of magnetic field driven spin transitions of
electrons in coupled lateral quantum dot molecules. A detailed numerical study
of spin phases of artificial molecules composed of two laterally coupled
quantum dots with N=8 electrons is presented as a function of magnetic field,
Zeeman energy, and the detuning using real space Hartree-Fock Configuration
Interaction (HF-CI) technique. A microscopic picture of quantum Hall
ferromagnetic phases corresponding to zero and full spin polarization at
filling factors $\nu=2$ and $\nu=1$, and ferrimagnetic phases resulting from
coupling of the two dots, is presented.",0612529v2
2006-12-27,"Partial antiferromagnetism in spin-chain Sr5Rh4O12, Ca5Ir3O12 and Ca4IrO6 single crystals","We report a structural, thermodynamic and transport study of the newly
synthesized Sr5Rh4O12, Ca5Ir3O12 and Ca4IrO6 single crystals. These
quasi-one-dimensional insulators consist of a triangular lattice of spin chains
running along the c-axis, and are commonly characterized by a partial
antiferromagnetic (AFM) order, a small entropy removal associated with the
phase transitions and a sizable low-temperature specific heat linearly
proportional to temperature. Sr5Rh4O12 is defined by an AFM order below 23 K
with strong evidence for an Ising character and two step-like transitions in
isothermal magnetization leading to a ferrimagnetic state at 2.4 T and a
ferromagnetic state at 4.8 T, respectively. Ca5Ir3O12 and Ca4IrO6 are also
antiferromagnetically ordered below 7.8 K and 12 K, respectively, and show an
unusually large ratio of the Curie-Weiss temperature to the Neel temperature.
In particular, Ca5Ir3O12, which includes both Ir4+ and Ir5+ ions, reveals that
only S=1/2 spins of the Ir4+ ions are involved in the magnetic ordering whereas
S=3/2 spins of the Ir5+ ions remain disordered. All results suggest the
presence of the geometrical frustration that causes incomplete long-range AFM
order in these quasi-one-dimensional compounds.",0612642v1
2007-01-01,Size dependence of the photoinduced magnetism and long-range ordering in Prussian blue analog nanoparticles of rubidium cobalt hexacyanoferrate,"Nanoparticles of rubidium cobalt hexacyanoferrate
(Rb$_j$Co$_k$[Fe(CN)$_6$]$_l \cdot n$H$_2$O) were synthesized using different
concentrations of the polyvinylpyrrolidone (PVP) to produce four different
batches of particles with characteristic diameters ranging from 3 to 13 nm.
Upon illumination with white light at 5 K, the magnetization of these particles
increases. The long-range ferrimagnetic ordering temperatures and the coercive
fields evolve with nanoparticle size. At 2 K, particles with diameters less
than approximately 10 nm provide a Curie-like magnetic signal.",0701027v2
2007-01-25,Doping of Mn$_2$VAl and Mn$_2$VSi Heusler alloys as a route to half-metallic antiferromagnetism,"Half-metallic antiferromagnets are the ideal materials for spintronic
applications since their zero magnetization leads to lower stray fields and
thus tiny energy losses. Starting from the Mn$_2$VAl and Mn$_2$VSi alloys we
substitute Co or Fe for Mn and we show by means of first-principle electronic
structure calculations that the resulting compounds are ferrimagnets. When the
total number of valence electrons reaches the magic number of 24 the Fe-doped
compounds are semi-metals and thus non-magnetic while the Co-doped ones show
the desirable half-metallic antiferromagnetic character. The compounds are very
likely to be synthesized experimentally since the parent compounds, Mn$_2$VAl
and Co$_2$VAl, have been already grown in the Heusler $L2_1$ lattice structure.",0701611v1
2007-03-26,Magnetodielectric coupling in Mn3O4,"We have investigated the dielectric anomalies associated with spin ordering
transitions in the tetragonal spinel Mn$_3$O$_4$, using thermodynamic,
magnetic, and dielectric measurements. We find that two of the three magnetic
ordering transitions in Mn$_3$O$_4$ lead to decreases in the temperature
dependent dielectric constant at zero applied field. Applying a magnetic field
to the polycrystalline sample leaves these two dielectric anomalies practically
unchanged, but leads to an increase in the dielectric constant at the
intermediate spin-ordering transition. We discuss possible origins for this
magnetodielectric behavior in terms of spin-phonon coupling. Band structure
calculations suggest that in its ferrimagnetic state, Mn$_3$O$_4$ corresponds
to a semiconductor with no orbital degeneracy due to strong Jahn-Teller
distortion.",0703685v1
1993-09-02,On a mean field approximation for Higgs-Yukawa systems,"We discuss the phase structure of a lattice Higgs-Yukawa system in the
variational mean field approximation with contributions of fermionic
determinant being calculated in a ladder approximation. In particular, we
demonstrate that in this approximation the ferrimagnetic phase in the $Z_2$
model with naive fermions can appear as an artifact of a finite lattice and
that the phase diagram for this model on infinite lattice changes qualitatively
at space-time dimension $D = 4$ compared with those at $D > 4$.",9309001v2
1994-02-03,Phase Diagram of An SU(2)xSU(2) Scalar-Fermion Model with Massless Decoupled Doublers,"We present the phase structure of the chiral SU(2)xSU(2) scalar-fermion model
on the lattice using the Zaragoza proposal for chiral fermions. The numerical
result agrees with an analytic study based on the use of weak and strong Yukawa
coupling expansions combined with the mean field approach. The phase diagram
consits of four phases: paramagnetic(PM), ferromagnetic(FM),
antiferromagnetic(AFM) and ferrimagnetic (FI). The transition lines separating
these four phases intersect at one quadruple point.",9402001v2
2006-04-13,Exchange Bias and Vertical Shift in CoFe2O4 nanoparticles,"Magnetic properties of core-shell cobalt ferrite nanoparticles 15 to 48nm
prepared by a sol-gel route have been studied. It is shown that the coercivity
follows non-monotonic size dependence varying as 1/d above the maximum (d is
the particle size). Field cooled magnetization exhibited both horizontal
(exchange bias) and vertical shifts. The exchange bias is understood as
originating at the interface between a surface region with structural and spin
disorder and a core ferrimagnetic region. The dependence of the exchange bias
and vertical shifts on the particle sizes and cooling fields are found to have
significant differences and the differences are explained in the light of
recent results which suggest that both weakly and strongly pinned spins are
present at the interface. It is suggested that the exchange bias is dominated
by the weakly pinned spins while the vertical shift is affected by the strongly
pinned ones.",0604027v1
2000-09-04,Test of Cosmic Spatial Isotropy for Polarized Electrons Using a Rotatable Torsion Balance,"To test the cosmic spatial isotropy, we use a rotatable torsion balance
carrying a transversely spin-polarized ferrimagnetic Dy_{6}Fe_{23} mass. With a
rotation period of one hour, the period of anisotropy signal is reduced from
one sidereal day by about 24 times, and hence the 1/f noise is greatly reduced.
Our present experimental results constrain the cosmic anisotropy Hamiltonian H
= C_{1} sigma_{1} + C_{2} sigma_{2} + C_{3} sigma_{3} (sigma_{3} is in the axis
of earth rotation) to (C_{1}^{2} +C_{2}^{2})^{1/2} = (1.8 +- 5.3) X 10^{-21} eV
and | C_{3} | = (1.2 +- 3.5) X 10^{-19} eV. This improves the previous limits
on (C_{1},C_{2}) by 120 times and C_{3} by a factor of 800.",0009012v1
2005-03-01,Large Magnetic Moments of Arsenic-Doped Mn Clusters and their Relevance to Mn-Doped III-V Semiconductor Ferromagnetism,"We report electronic and magnetic structure of arsenic-doped manganese
clusters from density-functional theory using generalized gradient
approximation for the exchange-correlation energy. We find that arsenic
stabilizes manganese clusters, though the ferromagnetic coupling between Mn
atoms are found only in Mn$_2$As and Mn$_4$As clusters with magnetic moments 9
$\mu_B$ and 17 $\mu_B$, respectively. For all other sizes, $x=$ 3, 5-10,
Mn$_x$As clusters show ferrimagnetic coupling. It is suggested that, if grown
during the low temperature MBE, the giant magnetic moments due to ferromagnetic
coupling in Mn$_2$As and Mn$_4$As clusters could play a role on the
ferromagnetism and on the variation observed in the Curie temperature of
Mn-doped III-V semiconductors.",0503009v1
2007-03-31,Formation of quasi-solitons in transverse confined ferromagnetic film media,"The formation of quasi-2D spin-wave waveforms in longitudinally magnetized
stripes of ferrimagnetic film was observed by using time- and space-resolved
Brillouin light scattering technique. In the linear regime it was found that
the confinement decreases the amplitude of dynamic magnetization near the
lateral stripe edges. Thus, the so-called effective dipolar pinning of dynamic
magnetization takes place at the edges.
  In the nonlinear regime a new stable spin wave packet propagating along a
waveguide structure, for which both transversal instability and interaction
with the side walls of the waveguide are important was observed. The
experiments and a numerical simulation of the pulse evolution show that the
shape of the formed waveforms and their behavior are strongly influenced by the
confinement.",0704.0024v1
2007-06-29,AC susceptibility and $^{51}$V NMR study of MnV$_2$O$_4$,"We report $^{51}$V zero-field NMR of manganese vanadate spinel of
MnV$_2$O$_4$, together with both ac and dc magnetization measurements. The
field and temperature dependence of ac susceptibilities show a
reentrant-spin-glass-like behavior below the ferrimagnetic(FEM) ordering
temperature. The zero-field NMR spectrum consists of multiple lines ranging
from 240 MHz to 320 MHz. Its temperature dependence reveals that the ground
state is given by the simultaneous formation of a long-range FEM order and a
short-range order component. We attribute the spin-glass-like anomalies to
freezing and fluctuations of the short-range ordered state caused by the
competition between spin and orbital ordering of the V site.",0707.0018v1
2007-07-05,"Supersolidity, entropy and frustration","We study the properties of t-t'-V model of hard-core bosons on the triangular
lattice that can be realized in optical lattices. By mapping to the spin-1/2
XXZ model in a field, we determine the phase diagram of the t-V model where the
supersolid characterized by the ordering pattern (x,x,-2x') (""ferrimagnetic"" or
SS A) is a ground state for chemical potential \mu >3V. By turning on either
temperature or t' at half-filling \mu =3V, we find a first order transition
from SS A to the elusive supersolid characterized by the (x,-x,0) ordering
pattern (""antiferromagnetic"" or SS C). In addition, we find a large region
where a superfluid phase becomes a solid upon raising temperature at fixed
chemical potential. This is an analog of the Pomeranchuk effect driven by the
large entropic effects associated with geometric frustration on the triangular
lattice.",0707.0866v1
2007-07-26,The phase structure of a chirally invariant lattice Higgs-Yukawa model - numerical simulations,"The phase diagram of a chirally invariant lattice Higgs-Yukawa model is
explored by means of numerical simulations. The results revealing a rich phase
structure are compared to analytical large Nf calculations which we performed
earlier. The analytical and numerical results are in excellent agreement at
large values of Nf. In the opposite case the large Nf computation still gives a
good qualitative description of the phase diagram. In particular we find
numerical evidence for the predicted ferrimagnetic phase at intermediate values
of the Yukawa coupling constant and for the symmetric phase at strong Yukawa
couplings. Emphasis is put on the finite size effects which can hide the
existence of the latter symmetric phase.",0707.3849v1
2007-09-26,Role of defects and disorder in the half-metallic full-Heusler compounds,"Half-metallic ferromagnets and especially the full-Heusler alloys containing
Co are at the center of scientific research due to their potential applications
in spintronics. For realistic devices it is important to control accurately the
creation of defects in these alloys. We review some of our late results on the
role of defects and impurities in these compounds. More precisely we present
results for the following cases (i) doping and disorder in Co$_2$Cr(Mn)Al(Si)
alloys, (ii) half-metallic ferrimagnetism appeared due to the creation of
Cr(Mn) antisites in these alloys, (iii) Co-doping in Mn$_2$VAl(Si) alloys
leading to half-metallic antiferromagnetism, and finally (iv) the occurrence of
vacancies in the full-Heusler alloys containing Co and Mn. These results are
susceptible of encouraging further theoretical and experimental research in the
properties of these compounds.",0709.4183v2
2007-10-19,Intrinsic avalanches and collective phenomena in a Mn(II)-free radical ferrimagnetic chain,"Magnetic hysteresis loops below 300 mK on single crystals of the Mn(II) -
nitronyl nitroxide free radical chain (Mn(hfac)_2({\it R})-3MLNN) present
abrupt reversals of the magnetization, or avalanches. We show that, below 200
mK, the avalanches occur at a constant field, independent of the sample and so
propose that this avalanche field is an intrinsic property. We compare this
field to the energy barrier existing in the sample and conclude that the
avalanches are provoked by multiple nucleation of domain-walls along the
chains. The different avalanche field observed in the zero field cooled
magnetization curves suggests that the avalanche mechanisms are related to the
competition between ferromagnetic and antiferromagnetic order in this compound.",0710.3707v2
2007-11-02,Origin of ferromagnetic response in diluted magnetic semiconductors and oxides,"This paper reviews the present understanding of the origin of ferromagnetic
response of diluted magnetic semiconductors and diluted magnetic oxides as well
as in some nominally magnetically undoped materials. It is argued that these
systems can be grouped into four classes. To the first belong composite
materials in which precipitations of a known ferromagnetic, ferrimagnetic or
antiferromagnetic compound account for magnetic characteristics at high
temperatures. The second class forms alloys showing chemical nano-scale phase
separation into the regions with small and large concentrations of the magnetic
constituent. To the third class belong (Ga,Mn)As, heavily doped p-(Zn,Mn)Te,
and related semiconductors. In these solid solutions the theory built on p-d
Zener's model of hole-mediated ferromagnetism and on either the Kohn-Luttinger
kp theory or the multi-orbital tight-binding approach describes qualitatively,
and often quantitatively many relevant properties. Finally, in a number of
carrier-doped DMS and DMO a competition between long-range ferromagnetic and
short-range antiferromagnetic interactions and/or the proximity of the
localisation boundary lead to an electronic nano-scale phase separation.",0711.0340v1
2007-11-12,Magnetic and orbital ordering in the spinel MnV2O4,"Neutron inelastic scattering and diffraction techniques have been used to
study the MnV2O4 spinel system. Our measurements show the existence of two
transitions to long-range ordered ferrimagnetic states; the first collinear and
the second noncollinear. The lower temperature transition, characterized by
development of antiferromagnetic components in the basal plane, is accompanied
by a tetragonal distortion and the appearance of a gap in the magnetic
excitation spectrum. The low-temperature noncollinear magnetic structure has
been definitively resolved. Taken together, the crystal and magnetic structures
indicate a staggered ordering of the V d orbitals. The anisotropy gap is a
consequence of unquenched V orbital angular momentum.",0711.1844v1
2007-11-22,Three Dimensional Magnetic Correlations in Multiferroic LuFe2O4,"We present single-crystal neutron diffraction measurements on multiferroic
LuFe2O4 showing phase transitions at 240 and 175 K. Magnetic reflections are
observed below each transition indicating that the magnetic interactions in
LuFe2O4 are 3-dimensional (3D) in character. The magnetic structure is refined
as a ferrimagnetic spin configuration below the 240 K transition. While 3D
magnetic correlations persists below 175 K, a significant broadening of the
magnetic peaks is observed along with the build up of a diffuse component to
the magnetic scattering.",0711.3560v4
2007-12-10,Fractional magnetization plateaus and magnetic order in the Shastry Sutherland magnet TmB4,"We investigate the phase diagram of TmB4, an Ising magnet on a frustrated
Shastry-Sutherland lattice by neutron diffraction and magnetization
experiments. At low temperature we find Neel order at low field, ferrimagnetic
order at high field and an intermediate phase with magnetization plateaus at
fractional values M/Msat = 1/7, 1/8, 1/9 ... and spatial stripe structures.
Using an effective S = 1/2 model and its equivalent two-dimensional (2D)
fermion gas we suggest that the magnetic properties of TmB4 are related to the
fractional quantum Hall effect of a 2D electron gas.",0712.1537v2
2007-12-12,Reentrant spin glass transition in LuFe2O4,"We have carried out a comprehensive investigation of magnetic properties of
LuFe$_2$O$_4$, using AC susceptibility, DC magnetization and specific heat. A
magnetic phase transition around $\sim$236 K was observed with DC magnetization
and specific heat measurements, which is identified as a paramagnetic to
ferrimagnetic transition based on the nonlinear susceptibility data. Upon
further cooling below this temperature, we also observed highly relaxational
magnetic behavior: the DC magnetization exhibits history and time dependence,
and the real and imaginary part of the AC susceptibility shows large frequency
dependence. Dynamic scaling of the AC susceptibility data suggests that this
low temperature phase can be described as a reentrant spin glass phase. We also
discuss magnetic field dependence of the spin glass transition and aging,
memory and rejuvenation effect below the glass transition temperature around
228 K.",0712.1975v1
2008-01-09,Magnetic coupling in highly-ordered NiO/Fe3O4(110): Ultrasharp magnetic interfaces vs. long-range magnetoelastic interactions,"We present a laterally resolved X-ray magnetic dichroism study of the
magnetic proximity effect in a highly ordered oxide system, i.e. NiO films on
Fe3O4(110). We found that the magnetic interface shows an ultrasharp
electronic, magnetic and structural transition from the ferrimagnet to the
antiferromagnet. The monolayer which forms the interface reconstructs to
NiFe2O4 and exhibits an enhanced Fe and Ni orbital moment, possibly caused by
bonding anisotropy or electronic interaction between Fe and Ni cations. The
absence of spin-flop coupling for this crystallographic orientation can be
explained by a structurally uncompensated interface and additional
magnetoelastic effects.",0801.1468v1
2008-01-28,Magnetism as a mass term of the edge states in graphene,"The magnetism by the edge states in graphene is investigated theoretically.
An instability of the pseudo-spin order of the edge states induces
ferrimagnetic order in the presence of the Coulomb interaction. Although the
next nearest-neighbor hopping can stabilize the pseudo-spin order, a strong
Coulomb interaction makes the pseudo-spin unpolarized and real spin polarized.
The magnetism of the edge states makes two peaks of the density of states in
the conduction and valence energy bands near the Fermi point. Using a
continuous model of the Weyl equation, we show that the edge-induced gauge
field and the spin dependent mass terms are keys to make the magnetism of the
edge states. A relationship between the magnetism of the edge states and the
parity anomaly is discussed.",0801.4170v1
2008-02-19,Jahn-Teller Distortion in Bimetallic Oxalates,"A C$_3$-symmetric crystal-field potential in the Fe(II)Fe(III) bimetallic
oxalates splits the L=2 Fe(II) multiplet into two doublets and a singlet. In
compounds that exhibit magnetic compensation, one of the doublets was predicted
to lie lowest in energy and carry a non-quenched orbital angular momentum $\pm
\ld $, where $\ld $ exceeds a threshold value. In a range of $\ld $, a
Jahn-Teller (JT) distortion increases the energy splitting of the low-lying
doublet and breaks the C$_3$ symmetry of the bimetallic planes around the
ferrimagnetic transition temperature. At low temperatures, the JT distortion
disappears in compounds that display magnetic compensation due to the
competition with the spin-orbit coupling. A comparison with recent measurements
provides strong evidence for this re-entrant, low-temperature JT transition and
a prediction for the normal, high-temperature JT transition. The size of the JT
distortion is estimated using first-principles calculations, which suggest that
the long-range ordering of smaller, non-C$_3$-symmetric organic cations can
eliminate magnetic compensation.",0802.2678v1
2008-03-29,Misfit Strain Induced Giant Magnetoelectric Coupling in Thin Ferroic Films,"We show that misfit strain originated from the film-substrate lattice
mismatch strongly increases the value of the quadratic magnetoelectric
coupling. The giant magnetoelectric coupling, size effects and misfit strain
cause strong changes of ferroic films phase diagrams at zero external magnetic
and electric fields, in particular, the transformation of antiferromagnetic
phase into ferromagnetic or ferrimagnetic ones for compressive or tensile
misfit strains correspondingly as well as thickness induced paramagnetic or/and
paraelectric phases appearance. Ferromagnetism appearance and magnetoelectric
coupling increase in thin ferroelectric-antiferromagnetic films is in agreement
with available experimental data and opens the way for tailoring of ferroic
films magnetic and electric properties.",0803.4246v2
2008-05-29,"Microscopic Evidence of Spin State Order and Spin State Phase Separation in Layered Cobaltites RBaCo2O5.5 with R=Y, Tb, Dy, and Ho","We report muon spin relaxation measurements on the magnetic structures of
RBaCo_2O_5.5 with R=Y, Tb, Dy, and Ho. Three different phases, one
ferrimagnetic and two antiferromagnetic, are identified below 300 K. They
consist of different ordered spin state arrangements of high-, intermediate-,
and low-spin Co^3+ of CoO_6 octahedra. Phase separation into well separated
regions with different spin state order is observed in the antiferromagnetic
phases. The unusual strongly anisotropic magnetoresistance and its onset at the
FM-AFM phase boundary is explained.",0805.4509v1
2008-08-11,Monitoring of band gap and magnetic state of graphene nanoribbons through vacancies,"Using first-principles plane wave calculations we predict that electronic and
magnetic properties of graphene nanoribbons can be affected by defect-induced
itinerant states. The band gaps of armchair nanoribbons can be modified by
hydrogen saturated holes. Defects due to periodically repeating vacancy or
divacancies induce metallization, as well as magnetization in non-magnetic
semiconducting nanoribbons due to the spin-polarization of local defect states.
Antiferromagnetic ground state of semiconducting zigzag ribbons can change to
ferrimagnetic state upon creation of vacancy defects, which reconstruct and
interact with edge states. Even more remarkable is that all these effects of
vacancy defects are found to depend on their geometry and position relative to
edges. It is shown that these effects can, in fact, be realized without really
creating defects.",0808.1468v1
2008-08-12,Magnetism Driven by Anion Vacancies in Superconducting $α$--FeSe$_{1-x}$,"To study the microscopic electronic and magnetic interactions in the
substoichiometric iron chalcogenide FeSe$_{1-x}$ which is observed to
superconduct at x~1/8 up to $T_c$=27 K, we use first principles methods to
study the Se vacancy in this nearly magnetic FeSe system. The vacancy forms a
ferrimagnetic cluster of eight Fe atoms, which for the ordered x=1/8 alloy
leads to half metallic conduction. Similar magnetic clusters are obtained for
FeTe$_{1-x}$ and for BaFe$_2$As$_2$ with an As vacancy, although neither of
these are half metallic. Based on fixed spin density results, we suggest the
low energy excitations in FeSe$_{1-x}$ are antiparamagnon-like with short
correlation length.",0808.1733v2
2008-09-11,Two dimensional XXZ-Ising model on square-hexagon lattice,"We study a two dimensional XXZ-Ising on square-hexagon (4-6) lattice with
spin-1/2. The phase diagram of the ground state energy is discussed, shown two
different ferrimagnetic states and two type of antiferromagnetic states, beside
of a ferromagnetic state. To solve this model, it could be mapped into the
eight-vertex model with union jack interaction term. Imposing exact solution
condition we find the region where the XXZ-Ising model on 4-6 lattice have
exact solutions with one free parameter, for symmetric eight-vertex model
condition. In this sense we explore the properties of the system and analyze
the competition of the interaction parameters providing the region where it has
an exact solution. However the present model does not satisfy the \textit{free
fermion} condition, unless for a trivial situation. Even so we are able to
discuss their critical points region, when the exactly solvable condition is
ignored.",0809.2015v2
2008-09-25,Magnetic Behavior of Single Crystalline Pr_{5}Ge_{3} and Tb_{5}Ge_{3}Compounds,"The results of the magnetization studies on Pr_{5}Ge_{3}and Tb_{5}Ge_{3}
single crystals are reported. Single Crystals of Pr_{5}Ge_{3} and Tb_{5}Ge_{3}
compounds were successfully grown by Czochralski method. These compounds
crystallize in a Mn_{5}Si_{3} type hexagonal structure with space group
P6_{3}/mcm. Ferromagnetic correlations set in at around 36 K in Pr_{5}Ge_{3} in
the ab plane followed by an antiferromagnetic transition at 13 K. Along the
c-axis the magnetization shows a ferromagnetic transition around 13 K with an
overall ferrimagnetic behavior. At 2K, the magnetic isotherm of the compound
along [0001] direction is typical for a ferromagnet, while a field induced
ferromagnetic type response is observed along the [10\overline{\mathit{1}}0]
direction. Hexagonal ab plane or [10\overline{\mathit{1}}0] direction was found
to be the easy axis of magnetization. Tb_{5}Ge_{3} orders antiferromagneticaly
at 85 K with the hexagonal ab plane as easy axis of magnetization. The compound
shows a field induced ferromagnetic behavior in its magnetic isotherm at 2 K.",0809.4467v2
2008-10-15,Vacancy-induced magnetism in SnO$_{2}$: A density functional study,"We study the magnetic and electronic properties of defects in SnO$_{2}$ using
pseudopotential and all electron methods. Our calculations show that bulk
SnO$_{2}$ is non-magnetic, but it shows magnetism with a magnetic moment around
4.00 $\mu_{B}$ due to Sn vacancy (V$_\mathrm{Sn}$). The magnetic moment comes
mainly from O atoms surrounding V$_\mathrm{Sn}$ and Sn atoms, which couple
antiferromagnetically with the O atoms in the presence of V$_\mathrm{Sn}$. The
coupling between different Sn vacancies is also studied and we find that these
defects not only couple ferromagnetically but also antiferromagnetically and
ferrimagnetically. Our calculations demonstrate that the experimentally
observed giant magnetic moment of transition metal doped SnO$_{2}$ can be
attributed to V$_\mathrm{Sn}$.",0810.2720v1
2008-11-11,Even-odd effects in finite Heisenberg spin chains,"Magnetic superlattices and nanowires may be described as Heisenberg spin
chains of finite length N, where N is the number of magnetic units (films or
atoms, respectively). We study antiferromagnetically coupled spins which are
also coupled to an external field H (superlattices) or to a ferromagnetic
substrate (nanowires). The model is analyzed through a two-dimensional map
which allows fast and reliable numerical calculations. Both open and closed
chains have different properties for even and odd N (parity effect). Open
chains with odd N are known [S.Lounis et al., Phys. Rev. Lett. 101, 107204
(2008)] to have a ferrimagnetic state for small N and a noncollinear state for
large N. In the present paper, the transition length N_c is found analytically.
Finally, we show that closed chains arrange themselves in the uniform bulk
spin-flop state for even N and in nonuniform states for odd N.",0811.1687v2
2008-11-12,Disorder Effects in La substituted ferrimagnetic Ca2FeMoO6 double perovskite,"Ca2-xLaxFeMoO6 double perovskite with La concentration x = 0 to 0.6 was
synthesized using solid state sintering route. The standard techniques of XRD,
SEM and EDX were applied to characterize the material. Crystal structure of the
samples was stabilized in monoclinic phase with space group P2I/n and lattice
expansion was indicated with the increase of x. The increase of La
concentration gradually suppressed the coexisting minor secondary phase in the
material and simultaneously, EDX results indicated the accommodation of more Mo
atoms in the crystal structure. A significant modification in the surface
morphology of the material was noted from adhesive type surface for x = 0 to
brittle type surface with more grain boundary contributions for La doped
samples. We understand a significant change in magnetic properties (appearance
of cluster glass component, reduction of magnetic moment and indication of
higher TC) and in electrical properties (reduction of metallic character) in
terms of enhanced internal disorder in the material, introduced due to La
doping in double perovskite structure.",0811.1876v2
2008-11-21,Magnetic Domains and Surface Effects in Hollow Maghemite Nanoparticles,"In the present work, we investigate the magnetic properties of ferrimagnetic
and noninteracting maghemite (g-Fe2O3) hollow nanoparticles obtained by the
Kirkendall effect. From the experimental characterization of their magnetic
behavior, we find that polycrystalline hollow maghemite nanoparticles are
characterized by low superparamagnetic-to-ferromagnetic transition
temperatures, small magnetic moments, significant coercivities and
irreversibility fields, and no magnetic saturation on external magnetic fields
up to 5 T. These results are interpreted in terms of the microstructural
parameters characterizing the maghemite shells by means of an atomistic Monte
Carlo simulation of an individual spherical shell model. The model comprises
strongly interacting crystallographic domains arranged in a spherical shell
with random orientations and anisotropy axis. The Monte Carlo simulation allows
discernment between the influence of the structure polycrystalline and its
hollow geometry, while revealing the magnetic domain arrangement in the
different temperature regimes.",0811.3592v2
2009-01-28,Epitaxial growth and magnetic properties of Sr2CrReO6 thin films,"The double perovskite Sr2CrReO6 is an interesting material for spintronics,
showing ferrimagnetism up to 635 K with a predicted high spin polarization of
about 86%. We fabricated Sr2CrReO6 epitaxial films by pulsed laser deposition
on (001)-oriented SrTiO3 substrates. Phase-pure films with optimum
crystallographic and magnetic properties were obtained by growing at a
substrate temperature of 700 degree C in pure O2 of 6.6x10-4 mbar. The films
are c-axis oriented, coherently strained, and show less than 20% anti-site
defects. The magnetization curves reveal high saturation magnetization of 0.8
muB per formula unit and high coercivity of 1.1 T, as well as a strong magnetic
anisotropy.",0901.4499v1
2009-03-11,Structure and Properties of Epitaxial Thin Films of Bi2fecro6: A Multiferroic Material Postulated by Ab-Initio Computation,"Experimental results on Bi2FeCrO6 (BFCO) epitaxial films deposited by laser
ablation on SrTiO3 substrates are presented. It has been theoretically
predicted using first-principles density functional theory that BFCO is
ferrimagnetic (with a magnetic moment of 2muB per formula unit) and
ferroelectric (with a polarization of ~80 microC/cm2 at 0K). The crystal
structure investigated using X-ray diffraction shows that the films are
epitaxial with a high degree of crystallinity. Chemical analysis carried out by
X-ray Microanalysis and X-ray Photoelectron Spectroscopy indicates the correct
cationic stoichiometry in the BFCO layer, namely (Bi:Fe:Cr = 2:1:1).
Cross-section high-resolution transmission electron microscopy images together
with selected area electron diffraction confirm the crystalline quality of the
epitaxial BFCO films with no identifiable foreign phase or inclusion. The
multiferroic character of BFCO is proven by piezoresponse force microscopy
(PFM) and magnetic measurements showing that the films exhibit ferroelectric
and magnetic hysteresis at room temperature. The local piezoelectric
measurements show the presence of ferroelectric domains and their switching at
the sub-micron scale.",0903.1995v1
2009-03-17,Observation of a Griffiths-like phase in the paramagnetic regime of ErCo_2,"A systematic x-ray magnetic circular dichroism study of the paramagnetic
phase of ErCo2 has recently allowed to identify the inversion of the net
magnetization of the Co net moment with respect to the applied field well above
the ferrimagnetic ordering temperature, Tc. The study of small angle neutron
scattering measurements has also shown the presence of short range order
correlations in the same temperature region. This phenomenon, which we have
denoted parimagnetism, may be related with the onset of a Griffiths-like phase
in paramagnetic ErCo2. We have measured ac susceptibility on ErCo2 as a
function of temperature, applied field, and excitation frequency. Several
characteristics shared by systems showing a Griffiths phase are present in
ErCo2, namely the formation of ferromagnetic clusters in the disordered phase,
the loss of analyticity of the magnetic susceptibility and its extreme
sensitivity to an applied magnetic field. The paramagnetic susceptibility
allows to establish that the magnetic clusters are only formed by Co moments as
well as the intrinsic nature of those Co moments.",0903.2931v1
2009-04-15,Order--disorder induced magnetic structures of FeMnP$_{0.75}$Si$_{0.25}$,"We report on the synthesis and structural characterization of the
magnetocaloric FeMnP$_{0.75}$Si$_{0.25}$ compound. Two types of samples (as
quenched and annealed) were synthesized and characterized structurally and
magnetically. We have found that minute changes in the degree of
crystallographic order causes a large change in the magnetic properties. The
annealed sample, with higher degree of order is antiferromagnetic with a zero
net moment. The as-quenched sample has a net moment of 1.26 $\mu_B$/f.u. and
ferrimagnetic-like behavior. Theoretical calculations give rather large values
for the Fe and Mn magnetic moments, both when occupied on the tetrahedral and
pyramidal lattice site. The largest being the Mn moment for the pyramidal site
reaches values as high as 2.8 $\mu_B$/atom.",0904.2256v1
2009-04-23,Magnetic order induced crystal symmetry lowering in ACr$_2$O$_4$ ferrimagnetic spinels,"We demonstrate that the onset of complex spin orders in ACr$_2$O$_4$ spinels
with magnetic A$=$Co, Fe and Cu ions lowers the lattice symmetry. This is
clearly indicated by the emergence of anisotropic lattice dynamics -- as
evidenced by the pronounced phonon splittings -- even when experiments probing
static distortions fail. We show that the crystal symmetry in the magnetic
phase is reduced from tetragonal to orthorhombic for FeCr$_2$O$_4$ and
CuCr$_2$O$_4$ with Jahn-Teller active A-site ions. The conical spin structure
in FeCr$_2$O$_4$ is also manifested in the phonon frequencies. In contrast, the
multiferroic CoCr$_2$O$_4$ with no orbital degrees of freedom remains nearly
cubic in its ground state.",0904.3712v1
2009-05-12,Large magnetic entropy change near room temperature in antipervoskite SnCMn3,"We report the observation of large magnetocaloric effect near room
temperature in antipervoskite SnCMn3. The maximal magnetic entropy change at
the first-order ferrimagnetic-paramagnetic transition temperature (TC 279 K) is
about 80.69mJ/cm3 K and 133mJ/cm3 K under the magnetic field of 20 kOe and 48
kOe, respectively. These values are close to those of typical magnetocaloric
materials. The large magnetocaloric effect is associated with the sharp change
of lattice, resistivity and magnetization in the vicinity of TC. Through the
measurements of Seebeck coefficient and normal Hall effect, the title system is
found to undergo a reconstruction of electronic structure at TC. Considering
its low-cost and innocuous raw materials, Mn-based antiperovskite compounds are
suggested to be appropriate for pursuing new materials with larger
magnetocaloric effect.",0905.1773v1
2009-06-08,"The observation of a positive magnetoresistance and close correlation among lattice, spin and charge around TC in antipervoskite SnCMn3","The temperature dependences of magnetization, electrical transport, and
thermal transport properties of antiperovskite compound SnCMn3 have been
investigated systematically. A positive magnetoresistance (~11%) is observed
around the ferrimagnetic-paramagnetic transition (TC ~ 280 K) in the field of
50 kOe, which can be attributed to the field-induced magnetic phase transition.
The abnormalities of resistivity, Seebeck coefficient, normal Hall effect and
thermal conductivity near TC are suggested to be associated with an abrupt
reconstruction of electronic structure. Further, our results indicate an
essential interaction among lattice, spin and charge degrees of freedom around
TC. Such an interaction among various degrees of freedom associated with sudden
phase transition is suggested to be characteristic of Mn-based antiperovskite
compounds.",0906.1511v1
2009-07-29,Analysis of optical magnetoelectric effect in GaFeO_3,"We study the optical absorption spectra in a polar ferrimagnet GaFeO_3. We
consider the E1, E2 and M1 processes on Fe atoms. It is shown that the
magnetoelectric effect on the absorption spectra arises from the E1-M1
interference process through the hybridization between the 4p and 3d states in
the noncentrosymmetry environment of Fe atoms. We perform a microscopic
calculation of the spectra on a cluster model of FeO_6 consisting of an
octahedron of O atoms and an Fe atom displaced from the center with reasonable
values for Coulomb interaction and hybridization. We obtain the magnetoelectric
spectra, which depend on the direction of magnetization, as a function of
photon energy in the optical region 1.0-2.5 eV, in agreement with the
experiment.",0907.5070v1
2009-08-20,Phase transitions in exactly solvable decorated model of localized Ising spins and itinerant electrons,"A hybrid lattice-statistical model of doubly decorated two-dimensional
lattices, which have localized Ising spins at its nodal sites and itinerant
electrons delocalized over decorating sites, is exactly solved with the help of
a generalized decoration-iteration transformation. Under the assumption of a
quarter filling of each couple of the decorating sites, the ground state
constitutes either spontaneously long-range ordered ferromagnetic or
ferrimagnetic phase in dependence on whether the ferromagnetic or
antiferromagnetic interaction between the localized Ising spins and itinerant
electrons is considered. The critical temperature of the spontaneously
long-range ordered phases monotonically increases upon strengthening the ratio
between the kinetic term and the Ising-type exchange interaction.",0908.2880v1
2009-08-24,"Spinel ferrite nanocrystals embedded inside ZnO: magnetic, electronic and magneto-transport properties","In this paper we show that spinel ferrite nanocrystals (NiFe2O4, and CoFe2O4)
can be texturally embedded inside a ZnO matrix by ion implantation and
post-annealing. The two kinds of ferrites show different magnetic properties,
e.g. coercivity and magnetization. Anomalous Hall effect and positive
magnetoresistance have been observed. Our study suggests a
ferrimagnet/semiconductor hybrid system for potential applications in
magneto-electronics. This hybrid system can be tuned by selecting different
transition metal ions (from Mn to Zn) to obtain various magnetic and electronic
properties.",0908.3488v1
2009-09-19,Cooperative order and excitation spectra in the bicomponent spin networks,"A ferrimagnetic spin model composed of $S=1/2$ spin-dimers and $S=5/2$
spin-chains is studied by combining the bond-operator representation (for
$S=1/2$ spin-dimers) and Holstein-Primakoff transformation (for $S=5/2$ spins).
A finite interaction $J_{\rm DF}$ between the spin-dimer and the spin chain
makes the spin chains ordered antiferromagnetically and the spin dimers
polarized. The effective interaction between the spin chains, mediated by the
spin dimers, is calculated up to the third order. The staggered magnetization
in the spin dimer is shown proportional to $J_{\rm DF}$. It presents an
effective staggered field reacting on the spin chains. The degeneracy of the
triplons is lifted due to the chain magnetization and a mode with longitudinal
polarization is identified. Due to the triplon-magnon interaction, the
hybridized triplon-like excitations show different behaviors near the vanishing
$J_{\rm DF}$. On the other hand, the hybridized magnon-like excitations open a
gap $\Delta_A\sim J_{\rm DF}$. These results consist well with the experiments
on Cu$_{2}$Fe$_{2}$Ge$_{4}$O$_{13}$.",0909.3576v2
2010-04-07,Magnetization plateau and incommensurate spin modulation in Ca3Co2O6,"The magnetic properties of a trigonal prism unit of the spin-2 frustrated
compound Ca3Co2O6 are studied by means of the density-matrix renormalization
group method. A magnetization plateau at $ms/3$ ($ms$ is the saturation
magnetization) with ferrimagnetic structure is observed. By fitting the
experimental data of magnetic curve, an estimation of the couplings gives
J1=-26.84K, J_{2}=0.39K, and J_{3}=0.52K. The local magnetic moments are
unveiled to exhibit an incommensurate sinusoidally modulation along the three
chains of the trigonal prism, which gives a strong theoretical support to the
experimentally observed incommensurate partially disordered antiferromagnetic
state for Ca3Co2O6. The present result suggests that the modulation indeed
originates from the competition of antiferromagnetic and ferromagnetic
couplings.",1004.1031v1
2010-04-08,Divergent effects of static disorder and hole doping in geometrically frustrated b-CaCr2O4,"The gallium substituted and calcium deficient variants of geometrically
frustrated b-CaCr2O4, b-CaCr2-2xGa2xO4 (0.02<= x<= 0.25) and b-Ca1-yCr2O4
(0.075<= y<= 0.15), have been investigated by x-ray powder diffraction,
magnetization and specific heat measurements. This allows for a direct
comparison of the effects, in a geometrically frustrated magnet, of the static
disorder that arises from non-magnetic substitution and the dynamic disorder
that arises from hole doping. In both cases, disturbing the Cr3+ lattice
results in a reduction in the degree of magnetic frustration. On substitution
of Ga, which introduces disorder without creating holes, a gradual release of
spins from ordered antiferromagnetic states is observed. In contrast, in the
calcium deficient compounds the introduction of holes induces static
ferrimagnetic ordering and much stronger perturbations of the b-CaCr2O4 host.",1004.1390v1
2010-06-24,Magnetodielectric coupling of infrared phonons in single crystal Cu$_{2}$OSeO$_{3}$,"Reflection and transmission as a function of temperature have been measured
on a single crystal of the magnetoelectric ferrimagnetic compound
Cu$_{2}$OSeO$_{3}$ utilizing light spanning the far infrared to the visible
portions of the electromagnetic spectrum. The complex dielectric function and
optical properties were obtained via Kramers-Kronig analysis and by fits to a
Drude-Lortentz model. The fits of the infrared phonons show a magnetodielectric
effect near the transition temperature ($T_{c}\sim 60$~K). Assignments to
strong far infrared phonon modes have been made, especially those exhibiting
anomalous behavior around the transition temperature.",1006.4676v1
2010-08-23,Self-magnetic compensation and Exchange Bias in ferromagnetic Samarium systems,"For Sm(3+) ions in a vast majority of metallic systems, the following
interesting scenario has been conjured up for long, namely, a magnetic lattice
of tiny self (spin-orbital) compensated 4f-moments exchange coupled (and phase
reversed) to the polarization in the conduction band. We report here the
identification of a self-compensation behavior in a variety of ferromagnetic Sm
intermetallics via the fingerprint of a shift in the magnetic hysteresis (M-H)
loop from the origin. Such an attribute, designated as exchange bias in the
context of ferromagnetic/antiferromagnetic multilayers, accords these compounds
a potential for niche applications in spintronics. We also present results on
magnetic compensation behavior on small Gd doping (2.5 atomic percent) in one
of the Sm ferromagnets (viz. SmCu(4)Pd). The doped system responds like a
pseudo-ferrimagnet and it displays a characteristic left-shifted linear M-H
plot for an antiferromagnet.",1008.3779v1
2010-10-09,Superparamagnetism in Nanocrystalline Copper Ferrite Thin Films,"The rf sputtered copper ferrite films contain nanocrystalline grains. In
these films, the magnetization does not saturate even in high magnetic fields.
This phenomenon of high field susceptibility is attributed to the defects
and/or superparamagnetic grains in the films. A simple model is developed to
describe the observed high field magnetization behavior of these films. The
model is found to fit well to the high field part for all the studied films. An
attempt is also made to explain the temperature variation of the ferrimagnetic
contribution on the basis of reported exchange constants.",1010.1877v1
2010-10-26,Phase transitions and thermodynamics of the two-dimensional Ising model on a distorted Kagomé lattice,"The two-dimensional Ising model on a distorted Kagom\'{e} lattice is studied
by means of exact solutions and the tensor renormalisation group (TRG) method.
The zero-field phase diagrams are obtained, where three phases such as
ferromagnetic, ferrimagnetic and paramagnetic phases, along with the
second-order phase transitions, have been identified. The TRG results are quite
accurate and reliable in comparison to the exact solutions. In a magnetic
field, the magnetization ($m$), susceptibility and specific heat are studied by
the TRG algorithm, where the $m=1/3$ plateaux are observed in the magnetization
curves for some couplings. The experimental data of susceptibility for the
complex Co(N$_3$)$_2$(bpg)$\cdot$ DMF$_{4/3}$ are fitted with the TRG results,
giving the couplings of the complex $J=22K$ and $J'=33K$.",1010.5297v1
2010-10-27,Electronic structure of fully epitaxial Co2TiSn thin films,"In this article we report on the properties of thin films of the full Heusler
compound Co2TiSn prepared by DC magnetron co-sputtering. Fully epitaxial,
stoichiometric films were obtained by deposition on MgO (001) substrates at
substrate temperatures above 600{\deg}C. The films are well ordered in the L21
structure, and the Curie temperature exceeds slightly the bulk value. They show
a significant, isotropic magnetoresistance and the resistivity becomes strongly
anomalous in the paramagnetic state. The films are weakly ferrimagnetic, with
nearly 1 \mu_B on the Co atoms, and a small antiparallel Ti moment, in
agreement with theoretical expectations. From comparison of x-ray absorption
spectra on the Co L3/L2 edges, including circular and linear magnetic
dichroism, with ab initio calculations of the x-ray absorption and circular
dichroism spectra we infer that the electronic structure of Co2TiSn has
essentially non-localized character. Spectral features that have not been
explained in detail before, are explained here in terms of the final state band
structure.",1010.5754v1
2010-12-15,Exchange interactions and Curie temperatures in Mn2CoZ compounds,"The generalized Heusler compounds Mn2CoZ (Z = Al, Ga, In, Si, Ge, Sn, Sb)
with the Hg2CuTi structure are of large interest due to their half-metallic
ferrimagnetism. The complex magnetic interactions between the constituents are
studied by first principles calculations of the Heisenberg exchange coupling
parameters, and Curie temperatures are calculated from those. Due to the direct
Mn-Mn exchange interaction in Mn2CoZ, the Curie temperature decreases, while
the total moment increases when changing Z from one group to another. The
exchange interactions are dominated by a strong direct exchange between Co and
its nearest neighbor Mn on the B site, which is nearly constant. The coupling
between the nearest-neighbor Mn atoms scales with the magnetic moment of the Mn
atom on the C site. Calculations with different lattice parameters suggest a
negative pressure dependence of the Curie temperature, which follows from
decreasing magnetic moments. Curie temperatures of more than 800 K are
predicted for Mn2CoAl (890 K), Mn2CoGa (886 K), and Mn2CoIn (845 K).",1012.3261v1
2011-01-10,Radiation of caustic beams from a collapsing bullet,"Collapse of an intense (2+1)-dimensional wave packet in a medium with cubic
nonlinearity and a two-dimensional dispersion of an order higher than parabolic
is studied both theoretically and experimentally. The carrier waves are
microwave backward volume spin waves which propagate in a stripe made from a
thin ferrimagnetic film and the packet is a spin-wave bullet. We show that
before being self-destroyed the bullet irradiates untrapped dispersive waves,
which is in agreement with a previous theoretical prediction. Since, in
addition, the ferromagnetic medium is characterized by an induced uniaxial
anisotropy, this radiation takes the form of narrow beams of continuous waves
at very specific angles to its propagation direction. Based on our theoretical
calculations we find that these beams are caustic beams and the angles are the
characteristic spin-wave caustic angles modified by the motion of the source.",1101.1696v2
2011-02-25,Origin and tailoring of the antiferromagnetic domain structure in $α$-Fe$_2$O$_3$ thin films unraveled by statistical analysis of dichroic spectro-microscopy (X-PEEM) images,"The magnetic microstructure and domain wall distribution of antiferromagnetic
$\alpha$-Fe$_2$O$_3$ epitaxial layers is determined by statistical image
analyses. Using dichroic spectro-microscopy images, we demonstrate that the
domain structure is statistically invariant with thickness and that the
antiferromagnetic domain structure of the thin films is inherited from the
ferrimagnetic precursor layer one, even after complete transformation into
antiferromagnetic $\alpha$-Fe$_2$O$_3$. We show that modifying the magnetic
domain structure of the precursor layer is a genuine way to tune the magnetic
domain structure and domain walls of the antiferromagnetic layers.",1102.5177v1
2011-03-11,Spin pumping by parametrically excited exchange magnons,"We experimentally show that exchange magnons can be detected using a
combination of spin pumping and inverse spin-Hall effect (iSHE) proving its
wavelength integrating capability down to the sub-micrometer scale. The magnons
were injected in a ferrimagnetic yttrium iron garnet film by parametric pumping
and the iSHE-induced voltage was detected in an attached Pt layer. The role of
the density, wavelength, and spatial localization of the magnons for the spin
pumping efficiency is revealed. This study opens the field of the magnon-based
information processing to magnons with nano-scale wavelengths.",1103.2229v2
2011-03-15,"Structural, Superconducting and Magnetic Properties of La(3-x)R(x)Ni2B2N3 (R = Ce, Pr, Nd)","We report on structural and superconducting properties of La(3-x)R(x)Ni2B2N3
where La is substituted by the magnetic rare-earth elements Ce, Pr, Nd. The
compounds Pr3Ni2B2N3 and Nd3Ni2B2N3 are characterized for the first time.
Powder X-ray diffraction confirmed all samples R3Ni2B2N3 with R = La, Ce, Pr,
Nd and their solid solutions to crystallize in the body centered tetragonal
La3Ni2B2N3 structure type. Superconducting and magnetic properties of
La(3-x)R(x)Ni2B2N3 were studied by resistivity, specific heat and
susceptibility measurements. While La3Ni2B2N3 has a superconducting transition
temperature Tc ~ 14 K, substitution of La by Ce, Pr, and Nd leads to magnetic
pair breaking and, thus, to a gradual suppression of superconductivity.
Pr3Ni2B2N3 exibits no long range magnetic order down to 2 K, Nd3Ni2B2N3 shows
ferrimagnetic ordering below T_C = 17 K and a spin reorientation transition to
a nearly antiferromagnetic state at 10 K.",1103.2947v1
2011-03-15,FFLO oscillations and magnetic domains in the Hubbard model with off-diagonal Coulomb repulsion,"We observe the effect of non-zero magnetization m onto the superconducting
ground state of the one dimensional repulsive Hubbard model with correlated
hopping X. For t/2 < X < 2t/3, the system first manifests
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) oscillations in the pair-pair
correlations. For m = m1 a kinetic energy driven macroscopic phase separation
into low-density superconducting domains and high-density polarized walls takes
place. For m > m2 the domains fully localize, and the system eventually becomes
a ferrimagnetic insulator.",1103.2962v3
2011-05-05,muSR investigation of magnetism and magnetoelectric coupling in Cu2OSeO3,"A detailed zero and transverse field (ZF&TF) muon spin rotation (muSR)
investigation of magnetism and the magneto-electric coupling in Cu2OSeO3 is
reported. An internal magnetic field B_int(T=0) = 85.37(25) mT was found, in
agreement with a ferrimagnetic state below Tc = 57.0(1) K. The temperature
dependence of the magnetic order parameter is well described by the relation
B_int = B(0)(1-(T/Tc)^2)^b with an effective exponent b = 0.39(1) which is
close to the critical exponent B ~ 1/3 for a three dimensional (3D) magnetic
system. Just above Tc the muon relaxation rate follows the power low \lambda
(T)\propto (T/Tc - 1)^\omega with \omega = 1.06(9), which is characteristic for
3D ferromagnets. Measurements of B_int(T) with and without an applied
electrostatic field E = 1.66 x 10^5 V/m suggest a possible electric field
effect of magnitude \Delta Bv = Bv(0 V)-Bv(500 V) = - 0.4(4) mT.",1105.1083v1
2011-05-25,Frustrated Ising model on the Cairo pentagonal lattice,"Through the direct decoration transformation approach, we obtain a general
solution for the pentagonal Ising model, showing its equivalence to the
isotropic free-fermion eight-vertex model. We study the ground-state phase
diagram, in which one ferromagnetic (FM) state, one ferrimagnetic (FIM) state,
and one frustrated state are found. Using the exact solution of the pentagonal
Ising model, we discuss the finite-temperature phase diagrams and find a phase
transition between the FIM state and the disordered state as well as a phase
transition between the disordered state and the FM state. We also discuss some
additional remarkable properties of the model, such as the magnetization,
entropy, and specific heat, at finite temperature and at its low-temperature
asymptotic limit. Because of the influence of the second-order phase transition
between the frustrated and ferromagnetic phases, we obtain surprisingly low
values of the entropy and the specific heat until the critical temperature is
reached.",1105.5130v3
2011-06-27,Crystal Structure and Magnetic Properties of the New Zn1.5Co1.5B7O13Br Boracite,"New Zn1.5Co1.5B7O13Br boracite crystals were grown by chemical transport
reactions in quartz ampoules, at a temperature of 1173 K. The crystal structure
was characterized by X-ray diffraction. The crystals present an orthorhombic
structure with space group Pca21, (No. 29). The determined cell parameters
were: a = 8.5705(3){\AA}, b = 8.5629(3) {\AA}, and c = 12.1198(4){\AA}, and
cell volume, V = 889.45(5) {\AA}3 with Z = 4. Magnetic properties in single
crystals of the new boracite, were determined. The Susceptibility-Temperature
(X -T) behavior at different magnetic intensities was studied. The inverse of
the magnetic susceptibility X-1(T) shows a Curie-Weiss characteristic with spin
s = 3/2 and a small orbital contribution, l. At low temperatures, below 10 K,
X(T) shows irreversibility that is strongly dependent on the applied magnetic
field. This boracite is ferrimagnetic up to a maximum temperature of about 16
K, as shows the coercive field. The reduction of the irreversibility by the
influence of the magnetic field, may be related to a metamagnetic phase
transition.",1106.5446v1
2011-07-05,Itinerant and local magnetic moments in ferrimagnetic Mn2CoGa thin films probed by x-ray magnetic linear dichroism: experiment and ab initio theory,"Epitaxial thin films of the half-metallic Xa-compound Mn2CoGa (Hg2CuTi
prototype) were prepared by dc magnetron co-sputtering with different heat
treatments on MgO (001) substrates. High-quality films with a bulk
magnetization of 1.95(5)\mu_B per unit cell were obtained. The L3,2 x-ray
magnetic circular dichroism spectra agree with calculations based on density
functional theory (DFT) and reveal the antiparallel alignment of the two
inequivalent Mn moments. X-ray magnetic linear dichroism, in good agreement
with theory as well, allows to distinguish between itinerant and local Mn
moments. Based on non-collinear spin DFT it is shown that one of the two Mn
moments has local character, whereas the other Mn moment and the Co moment are
itinerant.",1107.0887v2
2011-07-07,Correlations in the Ising antiferromagnet on the anisotropic kagome lattice,"We study the correlation function of middle spins, i. e. of spins on
intermediate sites between two adjacent parallel lattice axes, of the spatially
anisotropic Ising antiferromagnet on the kagome lattice. It is given rigorously
by a Toeplitz determinant. The large-distance behaviour of this correlation
function is obtained by analytic methods. For shorter distances we evaluate the
Toeplitz determinant numerically. The correlation function is found to vanish
exactly on a line J_d(T) in the T-J (temperature vs. coupling constant) phase
diagram. This disorder line divides the phase diagram into two regions. For J
less than J_d(T) the correlations display the features of an unfrustrated
two-dimensional Ising magnet, whereas for J greater than J_d(T) the
correlations between the middle spins are seen to be strongly influenced by the
short-range antiferromagnetic order that prevails among the spins of the
adjacent lattice axes. While for J less than J_d(T) there is a region with
ferrimagnetic long-range order, the model remains disordered for J greater than
J_d(T) down to T=0.",1107.1368v2
2011-07-12,Pressure- and Field-Tuning the Magnetostructural Phases of Mn3O4: Raman Scattering and X-Ray Diffraction Studies,"We present temperature-, magnetic-field-, and pressure-dependent Raman
scattering studies of single crystal Mn3O4, combined with temperature- and
field-dependent x-ray diffraction studies, revealing the novel
magnetostructural phases in Mn3O4. Our temperature-dependent studies showed
that the commensurate magnetic transition at T2=33K in the binary spinel Mn3O4
is associated with a structural transition from tetragonal to orthorhombic
structures. Field-dependent studies showed that the onset and nature of this
structural transition can be controlled with an applied magnetic field, and
revealed evidence for a field-tuned quantum phase transition to a tetragonal
spin-disordered phase for H||[1-10]. Pressure-dependent Raman measurements
showed that the magnetic easy axis direction in Mn3O4 can be controlled---and
the ferrimagnetic transition temperature increased---with applied pressure.
Finally, combined pressure- and magnetic-field-tuned Raman measurements
revealed a rich magnetostructural phase diagram---including a pressure- and
field-induced magnetically frustrated tetragonal phase in the PH phase
diagram---that can be generated in Mn3O4 with applied pressure and magnetic
field.",1107.2329v2
2011-08-13,First Principle Study of Magnetism and Magneto-structural Coupling in Gallium Ferrite,"We report a first-principles study of the magnetic properties, site disorder
and magneto-structural coupling in multiferroic gallium ferrite (GFO) using
local spin density approximation (LSDA+U) of density functional theory. The
calculations of the ground state A-type antiferromagnetic structure predict
magnetic moments consistent with the experiments whilst consideration of
spin-orbit coupling yields a net orbital moment of ~ 0.025 Bohr magneton/Fe
site also in good accordance with the experiments. We find that though site
disorder is not spontaneous in the ground state, interchange between Fe2 and
Ga2 sites is most favored in the disordered state. The results show that
ferrimagnetism in GFO is due to Ga-Fe site disordering such that Fe spins at
Ga1 and Ga2 sites are antiferromagnetically aligned while maintaining
ferromagnetic coupling between Fe spins at Ga1 and Fe1 sites as well as between
Fe spins at Ga2 and Fe2 sites. The effect of spin configuration on the
structural distortion clearly indicates presence of magneto-structural coupling
in GFO.",1108.2773v1
2011-08-31,Interplay between charge and magnetic orderings in the zero-bandwidth limit of the extended Hubbard model for strong on-site repulsion,"A simple effective model of charge ordered and (or) magnetically ordered
insulators is studied. The tight binding Hamiltonian analyzed consists of (i)
the effective on-site interaction U, (ii) the intersite density-density
interaction W and (iii) intersite magnetic exchange interaction Jz (or Jxy)
between nearest-neighbors. The intersite interaction are treated within the
mean-field approximation. One shows that the systems considered can exhibit
very interesting multicritical behaviors, including among others bicritical,
tricritical, tetracritical and critical end points. The analysis of the model
has been performed for an arbitrary electron concentration as well as an
arbitrary chemical potential in the limit of strong on-site repulsion. The
phase diagrams obtained in such a case are shown to consist of at least 9
different states, including four homogenous phases: nonordered (NO),
ferromagnetic (F), charge ordered (CO), ferrimagnetic (intermediate, I) and
five types of phase separation: NO-NO, F-NO, F-F, CO-F, CO-I.",1108.6181v1
2011-09-02,Symmetry Theory of the Flexomagnetoelectric Effect in the Bloch Lines,"It was shown, that there are 48 magnetic point groups of the Bloch lines
including 22 (11 time-invariant and 11 time-noninvariant) enantimorphic and 26
non-enantiomorphic groups. The Bloch lines with the time-noninvariant
enantiomorphism have identical types (parities) of the magnetization and
polarization dependences. The soliton like Bloch lines are derived from the
symmetry classification. The tip electrode method of the creation of these
Bloch lines is suggested for the potential applications in the magnetoelectric
memory devices. The method of the experimental determination of the
flexomagnetoelectric properties of the Bloch lines carried by the Bloch domain
walls has been suggested. New type of the flexomagnetoelectric coupling,
determined by the spatial derivatives of the electric polarization can be found
in the vicinity of the Curie temperature or compensation point of the
ferrimagnets. The multiple states Bloch line based magnetoelectric/multiferroic
memory is proposed. It can be considered as a concept of the magnetoelectric
enhancement of existing Bloch line memory invention.",1109.0531v1
2011-10-04,Zero and finite temperature mean field study of magnetic field induced electric polarization in Ba2CoGe2O7,"We investigate the spin-induced polarization in the multiferroic compound
Ba2CuGe2O7 using variarional and finite temperature mean field approaches. The
compound is described by a spin-3/2 Heisenberg model extended with easy plane
anisotropy and Dzyaloshinskii-Moriya (DM) interaction. Applying magnetic field
parallel to the [110] axis, three phases can be distinguished: (i) At high
magnetic field we find a partially magnetized phase with spins parallel to the
fields and uniform polarization; (ii) Below a critical field the ground state
is a twofold degenerate canted antiferromagnet, where the degeneracy can be
lifted by a finite DM interaction; (iii) At zero field a U(1) symmetry breaking
phase takes place, exhibiting a Goldstone-mode. To reproduce the magnetization
and polarization measurements reported in Murakawa et al. [Phys. Rev. Lett.
105, 137202 (2010)], we introduce an additional term in the Hamiltonian that
couples the polarizations on neighboring tetrahedra. This results in the
appearance of a canted ferrimagnetic phase for h < 1 T, characterized by a
finite staggered polarization, as well as by a finite magnetization along the
[-1,1,0] axis that leads to torque anomalies.",1110.0788v1
2011-10-05,Skyrmion quantum numbers and quantized pumping in two dimensional topological chiral magnets,"We investigate the general conditions to achieve the adiabatic charge and
spin polarizations and quantized pumping in 2D magnetic insulators possessing
inhomogeneous spin structures. In particular, we focus on the chiral
ferrimagnetic insulators which are generated via spontaneous symmetry breaking
from correlated two dimensional topological insulators. Adiabatic deformation
of the inhomogeneous spin structure generates the spin gauge flux, which
induces adiabatic charge and spin polarization currents. The unit pumped
charge/spin are determined by the product of two topological invariants which
are defined in momentum and real spaces, respectively. The same topological
invariants determine the charge and spin quantum numbers of skyrmion textures.
It is found that in noncentrosymmetric systems, a new topological phase, dubbed
the topological chiral magnetic insulator, exists in which a skyrmion defect is
a spin-1/2 fermion with electric charge $e$. Considering the adiabatic current
responses of generic inhomogeneous systems, it is shown that the quantized
topological response of chiral magnetic insulators is endowed with the second
Chern number.",1110.0946v2
2011-10-10,Magnetic order and frustrated dynamics in Li(Ni0.8Co0.1Mn0.1)O2: a study by μ+SR and SQUID magnetometry,"Recently, the mixed transition metal oxides of the form Li(Ni1-y-zCoyMnz)O2,
have become the center of attention as promising candidates for novel battery
material. These materials have also revealed very interesting magnetic
properties due to the alternate stacking of planes of metal oxides on a 2D
triangular lattice and the Li-layers. The title compound,
Li(Ni0.8Co0.1Mn0.1)O2, has been investigated by both magnetometry and
measurements and {\mu}+SR. We find the evolution of localized magnetic moments
with decreasing temperature below 70 K. The magnetic ground state (T = 2 K) is,
however, shown to be a frustrated system in 3D, followed by a transition into a
possible 2D spinglass above 22 K. With further increasing temperature the
compound show the presence of remaining correlations with increasing effective
dimensionality all the way up to the ferrimagnetic transition at TC = 70 K.",1110.2071v1
2011-10-17,Investigation of the magnetic phase transition and magnetocaloric properties of the Mn$_2$FeSbO$_6$ ilmenite,"The magnetic phase transition and magnetocaloric properties of mineral and
synthetic melanostibite Mn$_2$FeSbO$_6$ with ilmenite-type structure have been
studied. Mn$_2$FeSbO$_6$ orders ferrimagnetically below 270 K and is found to
undergo a second-order magnetic phase transition. The associated magnetic
entropy change amounts to 1.7 J/kgK for the mineral and 1.8 J/kgK synthetic
melanostibite for 5 T field change. For the synthetic Mn$_2$FeSbO$_6$ the
adiabatic temperature change was estimated from magnetic- and specific heat
measurements and amounts to 0.2 K in 1 T field change. Perspectives of the
promising functional properties of Mn$_2$FeSbO$_6$-based materials are
discussed.",1110.3624v2
2011-12-26,Surface properties of the clean and Au/Pd covered Fe$_3$O$_4$(111): a DFT and DFT+$U$ study,"The spin-density functional theory (DFT) and DFT+$U$ with Hubbard $U$ term
accounting for on-site Coulomb interactions were applied to investigate
structure, stability, and electronic properties of different terminations of
the Fe$_3$O$_4$(111) surface. All terminations of the ferrimagnetic
Fe$_3$O$_4$(111) surface exhibit very large (up to 90%) relaxations of the
first four interlayer distances, decreasing with the oxide layer depth. Our
calculations predict the iron terminated surface to be most stable in a wide
range of the accessible values of the oxygen chemical potential. The adsorption
of Au and Pd on two stable Fe- and O-terminated surfaces is studied. Our
results show that Pd binds stronger than Au both to the Fe- and O-terminated
surface. DFT+$U$ gives stronger bonding than DFT. The bonding of both
adsorbates to the O-terminated magnetite surface is by 1.5-2.5 eV stronger than
to the Fe-terminated surface.",1112.5827v1
2011-12-26,"Multiferroic and magnetoelectric nature of GaFeO3, AlFeO3 and related oxides","GaFeO3, AlFeO3 and related oxides are ferrimagnetic exhibiting
magnetodielectric effect. There has been no evidence to date for
ferroelectricity and hence multiferroicity in these oxides. We have
investigated these oxides as well as oxides of the composition
Al1-x-yGaxFe1+yO3 (x = 0.2, y = 0.2) for possible ferroelectricity by carrying
out pyroelectric measurements. These measurements establish the occurrence of
ferroelectricity at low temperatures below the N\`eel temperature in these
oxides. They also exhibit significant magnetoelectric effect. We have tried to
understand the origin of ferroelectricity based on non-centrosymmetric magnetic
ordering and disorder by carrying out first-principles calculations.",1112.5848v2
2011-12-27,Effective Soft-Mode Theory of Strongly Interacting Fermions,"An effective field theory for clean electron systems is developed in analogy
to the generalized nonlinear sigma-model for disordered interacting electrons.
The physical goal is to separate the soft or massless electronic degrees of
freedom from the massive ones and integrate out the latter to obtain a field
theory in terms of the soft degrees of freedom only. The resulting theory is
not perturbative with respect to the electron-electron interaction. It is
controlled by means of a systematic loop expansion and allows for a
renormalization-group analysis in a natural way. It is applicable to universal
phenomena within phases, and to transitions between phases, with order
parameters in arbitrary angular-momentum channels, and in the spin-singlet,
spin-triplet, particle-hole, and particle-particle channels. Applications
include ferromagnetic and ferrimagnetic ordering, non-s-wave ferromagnetic
order (magnetic nematics), Fermi-liquid to non-Fermi-liquid transitions, and
universal phenomena within a Fermi-liquid phase.",1112.5916v3
2012-02-26,Quantum Anomalous Hall Effect in Flat Band Ferromagnet,"We proposed a theory of quantum anomalous Hall effect in a flat-band
ferromagnet on a two-dimensional (2D) decorated lattice with spin-orbit
coupling. Free electrons on the lattice have dispersionless flat bands, and the
ground state is highly degenerate when each lattice site is occupied averagely
by one electron, i.e., the system is at half filling. The on-site Coulomb
interaction can remove the degeneracy and give rise to the ferrimagnetism,
which is the coexistence of the ferromagnetic and antiferromagnetic long-range
orders. On the other hand the spin-orbit coupling makes the band structure
topologically non-trivial, and produces the quantum spin Hall effect with a
pair of helical edge states around the system boundary. Based on the rigorous
results for the Hubbard model, we found that the Coulomb interaction can
provide an effective staggered potential and turn the quantum spin Hall phase
into a quantum anomalous Hall phase.",1202.5747v1
2012-06-07,Observation of different spin behavior with temperature variation and Cr substitution in a multiferroic compound YMn$_2$O$_5$,"In this article, the collective response of the spins is explored through low
field bulk magnetic measurement for the series YMn$_{2-x}$Cr$_x$O$_5$ (x= 0.0,
0.05). Low field ac susceptibility and dc magnetization of YMn$_2$O$_5$ shows
multiple transition in analogy to those observed in electrical measurement of
the compound. Using various time dependent magnetization protocols it has been
observed that the behavior of spins in commensurate and incommensurate phase
are drastically different. YMn$_{1.95}$Cr$_{0.05}$O$_5$ undergoes a
ferrimagnetic ordering with an enhanced magnetic ordering temperature as
compared to the parent, which undergoes an antiferromagnetic ordering.
Appearance of spontaneous magnetization without any major change in the atomic
structure is rather significant since the parent compound is an important
multiferroic material. In addition, magnetic memory effect is observed in the
Cr substituted compound whereas it is absent in the parent compound.",1206.1446v1
2012-06-21,Strong Dzyaloshinskii-Moriya Interaction and Origin of Ferroelectricity in Cu2OSeO3,"By performing density functional calculations, we investigate the origin of
the skyrmion state and ferroelectricity in Cu2OSeO3. We find that the
Dzyaloshinskii-Moriya interactions between the two different kinds of Cu ions
are extremely strong and induce the helical ground state and the skyrmion state
in the absence and presence of magnetic field, respectively. On the basis of
the general model for the spin-order induced polarization, we propose that the
ferroelectric polarization of Cu2OSeO3 in the collinear ferrimagnetic state
arises from an unusual mechanism, i.e., the single-spin-site contribution due
to the spin-orbit coupling.",1206.4792v2
2012-06-22,Investigation of bond dilution effects on the magnetic properties of a cylindrical Ising nanowire,"A cylindrical magnetic nanowire system composed of ferromagnetic core and
shell layers has been investigated by using effective field theory with
correlations. Both ferromagnetic and antiferromagnetic exchange couplings at
the core-shell interface have been considered. Main attention has been focused
on the effects of the quenched disordered shell bonds, as well as interface
bonds on the magnetic properties of the system. A complete picture of the phase
diagrams and magnetization profiles has been represented. It has been shown
that for the antiferromagnetic nanowire system, the magnetization curves can be
classified according to N\'{e}el theory of ferrimagnetism and it has been found
that under certain conditions, the magnetization profiles may exhibit Q-type,
P-type, N-type and L-type behaviors. The observed L-type behavior has not been
reported in the literature before for the equilibrium properties of nanoscaled
magnets. As another interesting feature of the system, it has been found that a
compensation point can be induced by a bond dilution process in the surface.
Furthermore, we have not found any evidence of neither the first order phase
transition characteristics, nor the reentrance phenomena.",1206.5326v1
2012-06-29,Light-induced magnetization reversal of high-anisotropy TbCo alloy films,"Magnetization reversal using circularly polarized light provides a new way to
control magnetization without any external magnetic field and has the potential
to revolutionize magnetic data storage. However, in order to reach ultra-high
density data storage, high anisotropy media providing thermal stability are
needed. Here, we evidence all-optical magnetization switching for different
TbxCo1-x ferrimagnetic alloy composition and demonstrate all-optical switching
for films with anisotropy fields reaching 6 T corresponding to anisotropy
constants of 3x106 ergs/cm3. Optical magnetization switching is observed only
for alloys which compensation temperature can be reached through sample
heating.",1206.6978v1
2012-07-11,Photoinduced Perturbations of the Magnetic Superexchange in Core-Shell Prussian Blue Analogues,"Cubic heterostructured (BA) particles of Prussian blue analogues, composed of
a shell of ferromagnetic K_{0.3}Ni[Cr(CN)_6]_{0.8} \cdot 1.3H_2O (A), Tc ~ 70
K, surrounding a bulk core of photoactive ferrimagnetic
Rb_{0.4}Co[Fe(CN)_6]_{0.8} \cdot 1.2H_2O (B), Tc ~20 K, have been studied.
Below Tc ~ 70 K, these samples exhibit a persistent photoinduced decrease in
low-field magnetization, and these results resemble data from other core-shell
particles and analogous ABA heterostructured films. This net decrease suggests
that the photoinduced lattice expansion in the B layer generates a
strain-induced decrease in the magnetization of the A layer, similar to a
pressure-induced decrease observed by others in a pure A-like material and by
us in our BA cubes. Upon further examination, the data also reveal a
significant portion of the A material whose superexchange, J, is perturbed by
the photoinduced strain from the B constituent.",1207.2623v1
2012-09-12,Modeling of the magnetic properties of nanomaterials with different crystalline structure,"We propose a method for modeling the magnetic properties of nanomaterials
with different structures. The method is based on the Ising model and the
approximation of the random field interaction. It is shown that in this
approximation, the magnetization of the nanocrystal depends only on the number
of nearest neighbors of the lattice atoms and the values of exchange integrals
between them. This gives a good algorithmic problem of calculating the
magnetization of any nano-object, whether it is ultrathin film or nanoparticle
of any shape and structure, managing only a rule of selection of nearest
neighbors. By setting different values of exchange integrals, it is easy to
describe ferromagnets, antiferromagnets, and ferrimagnets in a unified
formalism. Having obtained the magnetization curve of the sample it is possible
to find the Curie temperature as a function of, for example, the thickness of
ultrathin film. Afterwards one can obtain the numerical values for critical
exponents of the phase transition ""ferromagnet -- paramagnet"". Good agreement
between the results of calculations and the experimental data proves the
correctness of the method.",1209.3256v2
2012-09-17,Magnetism in MoS2 induced by MeV proton irradiation,"Molybdenum disulphide, a diamagnetic layered dichalcogenide solid, is found
to show magnetic ordering at room temperature when exposed to a 2 MeV proton
beam. The temperature dependence of magnetization displays ferrimagnetic
behavior with a Curie temperature of 895 K. A disorder mode corresponding to a
zone-edge phonon and a Mo valence higher than +4, have been detected in the
irradiated samples using Raman and X-ray photoelectron spectroscopy,
respectively. The possible origins of long-range magnetic ordering in
irradiated MoS2 samples are discussed.",1209.3569v1
2012-09-29,Realization of spin gapless semiconductors: the Heusler compound Mn2CoAl,"Recent studies have reported an interesting class of semiconductor materials
that bridge the gap between semiconductors and halfmetallic ferromagnets. These
materials, called spin gapless semiconductors, exhibit a bandgap in one of the
spin channels and a zero bandgap in the other and thus allow for tunable spin
transport. Here, a theoretical and experimental study of the spin gapless
Heusler compound Mn2CoAl is presented. It turns out that Mn2CoAl is a very
peculiar ferrimagnetic semiconductor with a magnetic moment of 2 {\mu}B and a
high Curie temperature of 720 K. Below 300 K, the compound exhibits nearly
temperature-independent conductivity, very low, temperature-independent carrier
concentration, and a vanishing Seebeck coefficient. The magnetoresistance
changes sign with temperature. In high fields, it is positive and
non-saturating at low temperatures, but negative and saturating at high
temperatures. The anomalous Hall effect is comparatively low, which is
explained by the close antisymmetry of the Berry curvature for kz of opposite
sign.",1210.0148v1
2012-10-05,Thermodynamics of Ising Spins on the Star Lattice,"There is a new class of two-dimensional magnetic materials polymeric iron
(III) acetate fabricated recently in which Fe ions form a star lattice. We
study the thermodynamics of Ising spins on the star lattice with exact analytic
method and Monte Carlo simulations. Mapping the star lattice to the honeycomb
lattice, we obtain the partition function for the system with asymmetric
interactions. The free energy, internal energy, specific heat, entropy and
susceptibility are presented, which can be used to determine the sign of the
interactions in the real materials. Moreover, we find the rich phase diagrams
of the system as a function of interactions, temperature and external magnetic
field. For frustrated interactions without external field, the ground state is
disordered (spin liquid) with residual entropy 1.522 per unit cell. When a weak
field is applied, the system enters a ferrimagnetic phase with residual entropy
ln4 per unit cell.",1210.1675v1
2012-10-10,Negative spin polarization of Mn2VGa probed by tunnel magnetoresistance,"The ferrimagnetic Heusler compound Mn2VGa is predicted to have a pseudogap in
the majority spin channel, which should lead to a negative tunnel
magnetoresistance. We synthesized epitaxial Mn2VGa thin films on MgO(001)
substrates by dc and rf magnetron co-sputtering, resulting in nearly
stoichiometric films. XRD analysis revealed a mostly B2-ordered structure for
the films deposited at substrate temperatures of 350{\deg}C, 450{\deg}C, and
550{\deg}C. Magnetic tunnel junctions with MgO barrier and CoFe
counter-electrodes were fabricated. After post-annealing at up to
T_a=425{\deg}C negative TMR was obtained around zero bias, providing evidence
for the inverted spin-polarization. Band structures of both electrodes were
computed within the coherent potential approximation and used to calculate the
TMR(V) characteristics, which are in good agreement with our experimental
findings.",1210.2966v1
2012-10-18,Parity effect in ground state localization of antiferromagnetic chains coupled to a ferromagnet,"We investigate the ground states of antiferromagnetic Mn nanochains on
Ni(110) by spin-polarized scanning tunneling microscopy in combination with
theory. While the ferrimagnetic linear trimer experimentally shows the
predicted collinear classical ground state, no magnetic contrast was observed
for dimers and tetramers where non-collinear structures were expected based on
ab-initio theory. This striking observation can be explained by zero-point
energy motion for even numbered chains derived within a classical equation of
motion leading to non classical ground states. Thus, depending on the parity of
the chain length, the system shows a classical or a quantum behavior.",1210.5220v1
2012-10-24,Theory of Half-Metallic Double Perovskites II: Effective Spin Hamiltonian and Disorder Effects,"Double perovskites like Sr$_2$FeMoO$_6$ are materials with half-metallic
ground states and ferrimagnetic T$_{\rm{c}}$'s well above room temperature.
This paper is the second of our comprehensive theory for half metallic double
perovskites. Here we derive an effective Hamiltonian for the Fe core spins by
""integrating out"" the itinerant Mo electrons and obtain an unusual double
square-root form of the spin-spin interaction. We validate the classical spin
Hamiltonian by comparing its results with those of the full quantum treatment
presented in the companion paper ""Theory of Half-Metallic Double Perovskites I:
Double Exchange Mechanism"". We then use the effective Hamiltonian to compute
magnetic properties as a function of temperature and disorder and discuss the
effect of excess Mo, excess Fe, and anti-site disorder on the magnetization and
T$_{\rm{c}}$. We conclude with a proposal to increase T$_{\rm{c}}$ without
sacrificing carrier polarization.",1210.6689v2
2012-11-05,Investigation of induced Pt magnetic polarization in Pt/Y3Fe5O12 bilayers,"Using X-ray magnetic circular dichroism (XMCD) measurements, we explore the
possible existence of induced magnetic moments in thin Pt films deposited onto
the ferrimagnetic insulator yttrium iron garnet (Y3Fe5O12). Such a magnetic
proximity effect is well established for Pt/ferromagnetic metal
heterostructures. Indeed, we observe a clear XMCD signal at the Pt L3 edge in
Pt/Fe bilayers, while no such signal can be discerned in XMCD traces of
Pt/Y3Fe5O12 bilayers. Integrating the XMCD signals allows to estimate an upper
limit for the induced Pt magnetic polarization in Pt/Y3Fe5O12 bilayers.",1211.0916v1
2012-12-19,Spontaneous atomic ordering and magnetism in epitaxially stabilized double perovskites,"We have studied the atomic ordering of B-site transition metals and magnetic
properties in the pulsed-laser deposited films of La2CrFeO6 (LCFO) and La2VMnO6
(LVMO), whose bulk materials are known to be single perovskites with random
distribution of the B-site cations. Despite similar ionic characters of
constituent transition metals in each compound, the maximum B-site order
attained was surprisingly high, ~90% for LCFO and ~80% for LVMO, suggesting a
significant role of epitaxial stabilization in the spontaneous ordering
process. Magnetization and valence state characterizations revealed that the
magnetic ground state of both compounds was coincidently ferrimagnetic with
saturation magnetization of ~2myuB per formula unit, unlike those predicted
theoretically. In addition, they were found to be insulating with optical band
gaps of 1.6 eV and 0.9 eV for LCFO and LVMO, respectively. Our results present
a wide opportunity to explore novel magnetic properties of binary
transition-metal perovskites upon epitaxial stabilization of the ordered phase.",1212.4622v1
2013-01-02,Spin-orbital locked magnetic excitations in a half-metallic double perovskite Ba2FeReO6,"We present a powder inelastic neutron scattering study of magnetic
excitations in Ba$_2$FeReO$_6$, a member of the double perovskite family of
materials which exhibit half-metallic behavior and high Curie temperatures. We
find clear evidence of two well-defined dispersing magnetic modes in its low
temperature ferrimagnetic state. We develop a local moment model, which
incorporates the interaction of Fe spins with spin-orbit locked magnetic
moments on Re, and show that this captures our experimental observations. Our
study further opens up double perovskites as model systems to explore the
interplay of strong correlations and spin-orbit coupling in 5d transition metal
oxides.",1301.0327v1
2013-01-08,Magnetic phases of mass- and population-imbalanced ultracold fermionic mixtures in optical lattices,"We study magnetic phases of two-component mixtures of ultracold fermions with
repulsive interactions in optical lattices in the presence of both hopping and
population imbalance by means of dynamical mean-field theory (DMFT). It is
shown that these mixtures can have easy-axis antiferromagnetic, ferrimagnetic,
charge-density wave, and canted-antiferromagnetic order or be unordered
depending on parameters of the system. We study the resulting phase diagram in
detail and investigate the stability of the different phases with respect to
thermal fluctuations. We also perform a quantitative analysis for a gas
confined in a harmonic trap, both within the local density approximation and
using a full real-space generalization of DMFT.",1301.1691v2
2013-01-09,High coercivity induced by mechanical milling in cobalt ferrite powders,"In this work we report a study of the magnetic behavior of ferrimagnetic
oxide CoFe2O4 treated by mechanical milling with different grinding balls. The
cobalt ferrite nanoparticles were prepared using a simple hydrothermal method
and annealed at 500oC. The non-milled sample presented coercivity of about 1.9
kOe, saturation magnetization of 69.5 emu/g, and a remanence ratio of 0.42.
After milling, two samples attained coercivity of 4.2 and 4.1 kOe, and
saturation magnetization of 67.0 and 71.4 emu/g respectively. The remanence
ratio MR/MS for these samples increase to 0.49 and 0.51, respectively. To
investigate the influence of the microstructure on the magnetic behavior of
these samples, we used X-ray powder diffraction (XPD), transmission electron
microscopy (TEM), and vibrating sample magnetometry (VSM). The XPD analysis by
the Williamson-Hall plot was used to estimate the average crystallite size and
strain induced by mechanical milling in the samples.",1301.1945v1
2013-01-21,Role of critical spin fluctuations in ultrafast demagnetization of transition-metal rare-earth alloys,"Ultrafast magnetization dynamics induced by femtosecond laser pulses have
been measured in ferrimagnetic Co0.8Gd0.2, Co.74Tb.26 and Co.86Tb.14 alloys.
Using element sensitivity of X-ray magnetic circular dichroism at the Co L3, Tb
M5 and Gd M5 edges we evidence that the demagnetization dynamics is element
dependent. We show that a thermalization time as fast as 280 fs is observed for
the rare-earth in the alloy, when the laser excited state temperature is below
the compensation temperature. It is limited to 500 fs when the laser excited
state temperature is below the Curie temperature (Tc). We propose critical spin
fluctuations in the vicinity of TC as the mechanism which reduces the
demagnetization rates of the 4f electrons in transition-metal rare-earth alloys
whereas at any different temperature the limited demagnetization rates could be
avoided.",1301.4885v3
2013-02-04,"Parimagnetism in RCo$_2$ series (R=Dy, Ho, and Tm)","X-ray circular magnetic dichroism (XMCD), longitudinal ($\chi_{ac}$) and
transverse (TS) ac magnetic susceptibility have been measured in several
members of the $R$Co$_2$ series ($R$ = Dy, Ho, and Tm) as a function of
temperature and applied magnetic field. We show that parimagnetism is a general
behavior along the $R$Co$_2$ ferrimagnetic series ($R$ being a heavy rare earth
ion). XMCD results evidence the presence of two compensation temperatures,
defining two different parimagnetic configurations, which is a fully unexpected
result. The inverse $\chi_{ac}$ curve exhibits a deviation from Curie-Weiss
behavior which is recovered under applied magnetic field. The large excess of
polarizability above the critical temperature proves the existence of an
enhanced effective moment due to the presence of short range magnetic
correlations, which are also observed in TS measurements. The combination of TS
and XMCD measurements allows to depict new magnetic phase diagrams for the
$R$Co$_2$ series. A new scenario allowing to understand the observed
phenomenology as a Griffiths phase-like behavior is proposed, where the
amorphous $R$Co$_2$ represents the undiluted system case.",1302.0775v1
2013-02-16,Room Temperature Nanoscale Ferroelectricity in Magnetoelectric GaFeO3 Epitaxial Thin Films,"We demonstrate room temperature ferroelectricity in the epitaxial thin films
of magnetoelectric GaFeO3. Piezo-force measurements show a 180o phase shift of
piezoresponse upon switching the electric field indicating nanoscale
ferroelectricity in epitaxial thin films of gallium ferrite. Further,
temperature dependent impedance analysis with and without the presence of an
external magnetic field clearly reveals a pronounced magneto-dielectric effect
across the magnetic transition temperature. In addition, our first principles
calculations show that Fe ions are not only responsible for ferrimagnetism as
observed earlier, but also give rise to the observed ferroelectricity, making
GFO an unique single phase multiferroic.",1302.3983v2
2013-02-27,Specific heat and thermal conductivity of ferromagnetic magnons in Yttrium Iron Garnet,"The specific heat and thermal conductivity of the insulating ferrimagnet
Y$_3$Fe$_5$O$_{12}$ (Yttrium Iron Garnet, YIG) single crystal were measured
down to 50 mK. The ferromagnetic magnon specific heat $C$$_m$ shows a
characteristic $T^{1.5}$ dependence down to 0.77 K. Below 0.77 K, a downward
deviation is observed, which is attributed to the magnetic dipole-dipole
interaction with typical magnitude of 10$^{-4}$ eV. The ferromagnetic magnon
thermal conductivity $\kappa_m$ does not show the characteristic $T^2$
dependence below 0.8 K. To fit the $\kappa_m$ data, both magnetic defect
scattering effect and dipole-dipole interaction are taken into account. These
results complete our understanding of the thermodynamic and thermal transport
properties of the low-lying ferromagnetic magnons.",1302.6739v1
2013-03-07,"Magnetic properties of the double perovskites LaPbMSbO6 (M = Mn, Co and Ni)","New double perovskites LaPbMSbO6, where M2+ = Mn2+, Co2+, and Ni2+, were
synthesized as polycrystals by an aqueous synthetic route at temperatures below
1000 oC. All samples are monoclinic, space group P21/n, as obtained from
Rietveld analysis of X-ray powder diffraction patterns. The distribution of M2+
and Sb5+ among the two octahedral sites have 3% of disorder for M2+ = Ni2+,
whereas for M2+ = Mn2+ and Co2+ less disorder is found. The three samples have
an antiferromagnetic transition, due to the antiferromagnetic coupling between
M2+ through super-superexchange paths M2+ - O2- - Sb5+ - O2- - M2+. Transition
temperatures are low: 8, 10 and 17 K for Mn2+, Co2+, and Ni2+ respectively, as
a consequence of the relatively long distances between the magnetic ions M2+.
Besides, for LaPbMnSbO6 a small transition at 45 K was found, with
ferrimagnetic characteristics, possibly as a consequence of a small disorder
between Mn2+ and Sb5+. This disorder would give additional and shorter
interaction paths: superexchange Mn2+ - O2- - Mn2+.",1303.1834v1
2013-04-04,The effect of Al doping on the structure and magnetism in cobaltite CaBaCo4O7,"We report the effects of Al-doping on the structure and magnetic properties
in CaBa(Co$_{1-x}$Al$_{x}$)$_4$O$_7$ (0$\leq$x$\leq$0.25). The system exhibits
a structural transition from an orthorhombic symmetry to a hexagonal symmetry
when the Al content exceeds $x =$ 0.1. The Curie temperature and the value of
the magnetization decrease with increasing Al doping level, indicating that the
ferrimagnetic ground state is gradually suppressed. The ground state eventually
transits into a spin-glass state for $x >$ 0.1. Moreover, the short-range
magnetic correlations, which occur at high temperatures in CaBaCo$_4$O$_7$, are
found to be gradually suppressed with increasing Al content and eventually
disappear for $x =$ 0.25. By comparing our results with other Co-site doping
cases, we suggest that the lattice and the spin degrees of freedom are
relatively decoupled in CaBaCo$_4$O$_7$.",1304.1387v1
2013-04-05,Laser-Induced Magnetic Nanostructures with Tunable Topological Properties,"We report the creation and real-space observation of magnetic structures with
well-defined topological properties and a lateral size as low as about 150 nm.
They are generated in a thin ferrimagnetic film by ultrashort single optical
laser pulses. Thanks to their topological properties, such structures can be
classified as Skyrmions of a particular type that does not require an
externally applied magnetic field for stabilization. Besides Skyrmions, we are
able to generate magnetic features with topological characteristics that can be
tuned by changing the laser fluence. The stability of such features is
accounted for by an analytical model based on the interplay between the
exchange and the magnetic dipole-dipole interactions",1304.1754v1
2013-04-08,YIG thickness and frequency dependence of the spin-charge current conversion in YIG/Pt systems,"We report the frequency dependence of the spin current emission in a hybrid
ferrimagnetic insulator/normal metal system as function of the insulating layer
thickness. The system is based on a yttrium iron garnet (YIG) film [0.2, 1, and
3 \mu m] grown by liquid-phase-epitaxy coupled with a spin current detector of
platinum [6 nm]. A strong YIG thickness dependence of the efficiency of the
spin pumping has been observed. The highest conversion factor \Delta V/P_{abs}
has been demonstrated for the thinner YIG (1.79 and 0.55 mV/mW^{-1} at 2.5 and
10 GHz, respectively) which presents an interest for the realisation of
YIG-based devices. A strong YIG thickness dependence of the efficiency of the
spin pumping has been also observed and we demonstrate the threshold frequency
dependence of the three-magnon splitting process.",1304.2190v1
2013-04-23,Converse Magnetoelectric Effects in Fe3O4/BaTiO3 Multiferroic Hybrids,"The quantitative understanding of converse magnetoelectric effects, i.e., the
variation of the magnetization as a function of an applied electric field, in
extrinsic multiferroic hybrids is a key prerequisite for the development of
future spintronic devices. We present a detailed study of the strain-mediated
converse magnetoelectric effect in ferrimagnetic Fe3O4 thin films on
ferroelectric BaTiO3 substrates at room temperature. The experimental results
are in excellent agreement with numerical simulation based on a two-region
model. This demonstrates that the electric field induced changes of the
magnetic state in the Fe3O4 thin film can be well described by the presence of
two different ferroelastic domains in the BaTiO3 substrate, resulting in two
differently strained regions in the Fe3O4 film with different magnetic
properties. The two-region model allows to predict the converse magnetoelectric
effects in multiferroic hybrid structures consisting of ferromagnetic thin
films on ferroelastic substrates.",1304.6315v1
2013-05-03,Design of Magnetic Textures of Ad-Nanocorrals with an Extra Adatom,"It is shown that in antiferromagnetic open or closed corrals of magnetic
adatoms grown on surfaces, the attachment of a single extra adatom anywhere in
the corral impacts on the geometrical topology of the nanosystem and generates
complex magnetic structures when a magnetic field is applied or a magnetic
coupling to a ferromagnetic substrate exists. The spin configuration of the
corral can be tuned to a non-planar state or a planar non-collinear or
ferrimagnetic state by adjusting its number of sites, the location of the extra
adatom or the strength of the coupling to the ferromagnetic substrate. This
shows the possibility to generate non-trivial magnetic textures with atom by
atom engineering anywhere in the corral and not only at the edges.",1305.0706v1
2013-05-22,Field-induced spin-structural transition and giant magnetostriction in Ising chain $α$-CoV$_2$O$_6$,"We have investigated the temperature and magnetic field dependence of
magnetization, specific heat ($C_p$), and relative sample length change
($\Delta L/L_0$) for understanding the field-induced spin-structural change in
quasi-one-dimensional spin chain $\alpha$-CoV$_2$O$_6$ which undergoes
antiferromagnetic (AFM) transition below $T_N$$=$15 K. Analysis of $C_p$($T$)
shows that an effective $S$$=$1/2 Ising state is realized below 20 K, though
the magnetic fluctuations persist well above $T_N$. $C_p$ and the coefficient
of linear thermal expansion ($\alpha$) exhibit strong $H$ dependence in the AFM
state. We also observe a huge positive magnetostriction [$\Delta L$($H$)/$L_0$]
below 20 K which does not show any tendency of saturation up to 9 T. With
increasing field, a sharp and symmetric peak emerges below $T_N$ in both
$C_p$($T$) and $\alpha$($T$) due to field-induced first order
ferrimagnetic/ferromagnetic-paramagnetic transitions. The large value of
magnetostriction below $T_N$ suggests strong spin-lattice coupling in
$\alpha$-CoV$_2$O$_6$.",1305.5027v2
2013-06-29,Strain-induced enhancement of coercivity in amorphous TbFeCo films,"We report a strong size dependence of coercivity in amorphous ferrimagnetic
TbFeCo films. The as-deposited film exhibited a low saturation magnetization
(Ms=100 emu/cc) and a high perpendicular anisotropy (Ku=10^6 erg/cc). Hall-bar
devices were fabricated for characterizing the magneto-transport behaviors. A
significant increase in coercivity (up to 300 %) was observed at room
temperature as the width of Hall bar was reduced. The large coercivity
enhancement was attributed to the relaxation of film stress. The effect of
strain and dimensionality on the coercivity in TbFeCo makes it attractive for
tunable coercivity and the magnetization reversal in future nanoscale devices.",1307.0057v1
2013-07-04,Spin Hall magnetoresistance at Pt/CoFe2O4 interfaces and texture effects,"We report magnetoresistance measurements on thin Pt bars grown on epitaxial
(001) and (111) CoFe2O4 (CFO) ferrimagnetic insulating films. The results can
be described in terms of the recently discovered spin Hall magnetoresistance
(SMR). The magnitude of the SMR depends on the interface preparation
conditions, being optimal when Pt/CFO samples are prepared in situ, in a single
process. The spin-mixing interface conductance, the key parameter governing SMR
and other relevant spin-dependent phenomena such as spin pumping or spin
Seebeck effect, is found to be different depending on the crystallographic
orientation of CFO, highlighting the role of the composition and density of
magnetic ions at the interface on spin mixing.",1307.1267v3
2013-07-09,Lattice Instability and Competing Spin Structures in the Double Perovskite Insulator Sr2FeOsO6,"The semiconductor Sr2FeOsO6, depending on temperature, adopts two types of
spin structures that differ in the spin sequence of ferrimagnetic iron - osmium
layers along the tetragonal c-axis. Neutron powder diffraction experiments,
57Fe M\""ossbauer spectra, and density-functional theory calculations suggest
that this behavior arises because a lattice instability resulting in
alternating iron-osmium distances fine-tunes the balance of competing exchange
interactions. Thus, Sr2FeOsO6 is an example for a double perovskite, in which
the electronic phases are controlled by the interplay of spin, orbital, and
lattice degrees of freedom.",1307.2587v2
2013-07-10,Doping a correlated band insulator: A new route to half metallic behaviour,"We demonstrate in a simple model the surprising result that turning on an
on-site Coulomb interaction U in a doped band insulator leads to the formation
of a half-metallic state. In the undoped system, we show that increasing U
leads to a first order transition between a paramagnetic, band insulator and an
antiferomagnetic Mott insulator at a finite value U_{AF}. Upon doping, the
system exhibits half metallic ferrimagnetism over a wide range of doping and
interaction strengths on either side of U_{AF}. Our results, based on dynamical
mean field theory, suggest a novel route to half-metallic behavior and provide
motivation for experiments on new materials for spintronics.",1307.2693v1
2013-10-02,Full Control of Magnetism in Manganite Bilayer by Ferroelectric Polarization,"An oxide heterostructure made of manganite bilayers and ferroelectric
perovskites is predicted to lead to the full control of magnetism when
switching the ferroelectric polarizations. By using asymmetric polar interfaces
in the superlattices, more electrons occupy the Mn layer at the $n$-type
interface side than at the $p$-type side. This charge disproportionation can be
enhanced or suppressed by the ferroelectric polarization. Quantum model and
density functional theory calculations reach the same conclusion: a
ferromagnetic-ferrimagnetic phase transition with maximal change $>90%$ of the
total magnetization can be achieved by switching the polarization's direction.
This function is robust and provides full control of the magnetization's
magnitude, not only its direction, via electrical methods.",1310.0811v1
2013-10-05,Ferrimagnetism in the Heisenberg-Ising Bilayer with Magnetically Non-equivalent Planes,"The Pair Approximation method is applied to the antiferromagnetic
Heisenberg-Ising spin-1/2 bilayer with a simple cubic crystalline structure.
The method allows for self-consistent calculations of thermodynamic quantities,
based on the determination of Gibbs free-energy. In the paper the phase
diagrams and planar magnetizations are calculated for the system in question.
Special attention is paid to the case of magnetically non-equivalent planes,
one of which is additionally randomly diluted. The occurrence of a compensation
phenomenon is found and the compensation temperature is discussed for such a
system. The characteristic concentration of magnetic atoms $p^{\star}$, below
which the compensation phenomenon vanishes, is examined as a function of the
Hamiltonian parameters.",1310.1457v2
2013-10-11,Phase boundaries of a spin-3/2 Blume-Emery-Griffiths model on a honeycomb lattice,"The spin-3/2 Blume-Emery-Griffiths model on a honeycomb lattice is studied by
Monte Carlo simulations with the goal to determine phase diagrams for a range
of the model parameters and to investigate the nature of the phase transitions
between the respective phases. For positive values of the biquadratic to
bilinear interaction ratio $\alpha$, we find two ferromagnetically ordered
phases, F1 and F2, with the sublattice magnetizations (1/2,1/2) and (3/2,3/2),
respectively, and our results confirm the discontinuous character of the
order-disorder critical line as a function of the single-ion anisotropy
strength, predicted by the effective-field theory (EFT). For negative values of
$\alpha$, there is another ferrimagnetic (FRM) phase of the type (1/2,3/2),
located between F1 and F2. However, the step-like variation of the
order-disorder critical frontier obtained from EFT for large negative $\alpha$
is not reproduced and thus deemed artifact of the EFT approximation.
Finite-size scaling analysis performed at various points between the respective
identified phases gave the ratio of critical exponents $\gamma/\nu$ consistent
with the 2D Ising universality class, except in the vicinity of the boundary
intersection, where the results deviated from the standard values beyond the
measurement errors.",1310.3296v1
2013-10-13,Jahn-Teller distortion induced magnetic phase transition in cubic BaFeO$_{3}$,"Using density functional theory (DFT) with local density approximation (LDA)
and generalized gradient approximation (GGA) correlation functionals, the
electronic and magnetic structures of cubic BaFeO$_{3}$ in the ferromagnetic
(FM) and antiferromagnetic (AFM) states are studied. Our LDA/GGA and
LDA$+U$/GGA$+U$ results show that cubic BFO has a FM ground state, in agreement
with recent experimental works. Two types of Jahn-Teller (JT) distortions,
denoted as JT1 and JT2, are considered. We find FM to ferrimagnetic (FIM) and
FM to AFM magnetic phase transitionn in the JT1 and JT2 type of distortions,
respectively. Larger strains are required for the FM-AFM transition as compared
to the FM-FIM. DFT$+U$ calculations also show that the magnetic moments
dramatically decrease at large strains due to strong overlapping between the Fe
and O atoms. The origins of these transitions is discussed in terms of a
competition between double exchange and superexchange interactions. Oxygen and
Fe displacements are therefore responsible for the magnetic phase transitions
and the reduction of the magnetic moments.",1310.3502v1
2013-11-02,Interface-induced magnetism in perovskite quantum wells,"We investigate the angular dependence of the magnetoresistance of thin (< 1
nm), metallic SrTiO3 quantum wells epitaxially embedded in insulating,
ferrimagnetic GdTiO3 and insulating, antiferromagnetic SmTiO3, respectively.
The SrTiO3 quantum wells contain a high density of mobile electrons (~7x10^14
cm^-2). We show that the longitudinal and transverse magnetoresistance in the
structures with GdTiO3 are consistent with anisotropic magnetoresistance, and
thus indicative of induced ferromagnetism in the SrTiO3, rather than a
nonequilibrium proximity effect. Comparison with the structures with
antiferromagnetic SmTiO3 shows that the properties of thin SrTiO3 quantum wells
can be tuned to obtain magnetic states that do not exist in the bulk material.",1311.0337v1
2013-11-19,Observation of the spin Peltier effect,"We report the observation of the spin Peltier effect (SPE) in the
ferrimagnetic insulator Yttrium Iron Garnet (YIG), i.e. a heat current
generated by a spin current flowing through a Platinum (Pt)|YIG interface. The
effect can be explained by the spin torque that transforms the spin current in
the Pt into a magnon current in the YIG. Via magnon-phonon interactions the
magnetic fluctuations modulate the phonon temperature that is detected by a
thermopile close to the interface. By finite-element modelling we verify the
reciprocity between the spin Peltier and spin Seebeck effect. The observed
strong coupling between thermal magnons and phonons in YIG is attractive for
nanoscale cooling techniques.",1311.4772v1
2013-12-04,Physical characteristics and cation distribution of NiFe2O4 thin films with high resistivity prepared by reactive co-sputtering,"We fabricated NiFe2O thin films on MgAl2O4 (001) substrates by reactive dc
magnetron co-sputtering in a pure oxygen atmosphere at different substrate
temperatures. The film properties were investigated by various techniques with
a focus on their structure, surface topography, magnetic characteristics, and
transport properties. Structural analysis revealed a good crystallization with
epitaxial growth and low roughness and a similar quality as in films grown by
pulsed laser deposition. Electrical conductivity measurements showed high room
temperature resistivity (12 Ohmm), but low activation energy, indicating an
extrinsic transport mechanism. A band gap of about 1.55 eV was found by optical
spectroscopy. Detailed x-ray spectroscopy studies confirmed the samples to be
ferrimagnetic with fully compensated Fe moments. By comparison with multiplet
calculations of the spectra we found that the cation valencies are to a large
extent Ni2+ and Fe3+.",1312.1086v1
2013-12-27,Ground-state magnetic phase diagram of bow-tie graphene nanoflakes in external magnetic field,"The magnetic phase diagram of a ground state is studied theoretically for
graphene nanoflakes of bow-tie shape and various size in external in-plane
magnetic field. The tight-binding Hamiltonian supplemented with Hubbard term is
used to model the electronic structure of the systems in question. The
existence of the antiferromagnetic phase with magnetic moments localized at the
sides of the bow-tie is found for low field and a field-induced spin-flip
transition to ferromagnetic state is predicted to occur in charge-undoped
structures. For small nanoflake doped with a single charge carrier the
low-field phase is ferrimagnetic and a metamagnetic transition to ferromagnetic
ordering can be forced by the field. The critical field is found to decrease
with increasing size of the nanoflake. The influence of diagonal and
off-diagonal disorder on the mentioned magnetic properties is studied. The
effect of off-diagonal disorder is found to be more important than this of
diagonal disorder, leading to significantly widened distribution of critical
fields for disordered population of nanoflakes.",1312.7298v1
2014-01-18,"Magnetic Moment and Band Structure Analysis of Fe, Co, Ni-modified Graphene-nano- ribbon","Magnetic properties and band characteristics of graphene-nano-ribbon (GNR)
modified by Fe, Co, and Ni were analyzed by the first principles DFT
calculation. Typical unit cell is [C32H2Fe1], [C32H2Co1] and [C32H2Ni1]
respectively. The most stable spin state was Sz=4/2 for Fe-modified GNR,
whereas Sz=3/2 for Co-case and Sz=2/2 for Ni-case. Atomic magnetic moment of
Fe, Co and Ni were 3.63, 2.49 and 1.26 {\mu}B, which were reduced values than
that of atomic Hund-rule due to magnetic coupling with graphene network. There
is a possibility for a ferromagnetic Fe, Co and Ni spin array through an
interaction with carbon pi-conjugated spin system. By expanding a unit cell of
Co-modified case as [C96H6Co3], ferromagnetic like spin state and ferrimagnetic
like one were compared. It was concluded that ferromagnetic state was more
stable magnetic state. Band calculations of Co-modified case show half-metal
like structure with relatively large band gap (0.55eV) for up-spin, whereas
small gap (0.05eV) for down-spin. This suggested a capability of spintronics
application like a spin fiter.",1401.4504v1
2014-01-27,Prospects for electron spin-dependent short-range force experiments with rare earth iron garnet test masses,"A study of the possible interactions between fermions assuming only
rotational invariance has revealed 15 forms for the potential involving the
fermion spins. We review the experimental constraints on unobserved
macroscopic, spin-dependent interactions between electrons in the range below 1
cm. An existing experiment, using 1 kHz mechanical oscillators as test masses,
has been used to constrain mass-coupled forces in this range. With suitable
modifications, including spin-polarized test masses, this experiment can be
used to explore all 15 possible spin-dependent interactions between electrons
in this range with unprecedented sensitivity. Samples of ferrimagnetic
dysprosium iron garnet have been fabricated in the suitable test mass geometry
and shown to have high spin density with very low intrinsic magnetism.",1401.6730v2
2014-01-30,Temperature dependent spin transport properties of Platinum inferred from spin Hall magnetoresistance measurements,"We study the temperature dependence of the spin Hall magnetoresistance (SMR)
in yttrium iron garnet/platinum hybrid structures via magnetization orientation
dependent magnetoresistance measurements. Our experiments show a decrease of
the SMR magnitude with decreasing temperature. Using the sensitivity of the SMR
to the spin transport properties of the normal metal, we interpret our data in
terms of a decrease of the spin Hall angle in platinum from 0.11 at room
temperature to 0.075 at 10K, while the spin diffusion length and the spin
mixing conductance of the ferrimagnetic insulator/normal metal interface remain
almost constant.",1401.7787v4
2014-02-07,Effects of Structural Distortion Induced by Sc Substitution in LuFe$_2$O$_4$,"We have studied the correlation between the structural distortion and the
electronic/magnetic properties in single-crystalline (Lu,Sc)Fe$_2$O$_4$
(Sc=0.05 and 0.3) by using X-ray diffraction (XRD), magnetic susceptibility,
and X-ray absorption spectroscopy (XAS)/x-ray magnetic circular dichroism
(XMCD)measurements. The Rietveld structure analysis of the XRD patterns
revealed that the Sc substitution induced an elongation of the FeO$_5$
bipyramidal cages in LuFe$_2$O$_4$ and increased the Fe$_2$O$_4$ bilayer
thickness. A non-negligible decrease in the ferrimagnetic transition
temperature T$_C$ is observed in the magnetic susceptibility curve of the
Sc=0.3 sample, but the XAS/XMCD spectra do not show any difference except for a
small reduction of dichroism signals at the Fe$^{3+}$ absorption edge. We
interpret this suppression of T$_C$ to be the result of a decreased spin-orbit
coupling effect in the Fe$^{2+}$ $e_{1g}$ doublet under $D_{3h}$ symmetry,
which is induced by the weakened structural asymmetry of the FeO$_5$
bipyramids.",1402.1685v3
2014-04-07,Co-existence of ferromagnetic and antiferromagnetic interactions in Mn$_3$Ga$ _{(1-x)} $Sn$_x$C,"The magnetic properties of the Mn$_3$Ga$_{(1-x)}$Sn$_x$C, 0 $\le$ x $\le$ 1
antiperovskite compounds have been investigated in detail. Though all compounds
of this series crystallize in a cubic structure, the Ga rich (x $\le$ 0.2)
compounds transform, via a first order transformation, to an antiferromagnetic
ground state and the Sn rich (x $\ge$ 0.8) compounds exhibit dominant
ferromagnetic interactions at low temperature. In the intermediate range (0.4
$\le$ x $\le$ 0.7) co-existence of ferromagnetic and antiferromagnetic
interactions can be seen. The results have been explained to be due to growth
of ferromagnetic sub-lattice at the expense of antiferromagnetic sub-lattice
with increasing Sn concentration in Mn$_3$Ga$_{(1-x)}$Sn$_x$C. This growth
occurs to a point where the first-order transition is altered from a
ferromagnetic - antiferromagnetic type in Ga rich compounds to a paramagnetic -
ferrimagnetic type in Mn$_3$SnC.",1404.1753v1
2014-04-07,Fingerprints of Galactic Loop I on the Cosmic Microwave Background,"We investigate possible imprints of galactic foreground structures such as
the ""radio loops"" in the derived maps of the cosmic microwave background.
Surprisingly there is evidence for these not only at radio frequencies through
their synchrotron radiation, but also at microwave frequencies where emission
by dust dominates. This suggests the mechanism is magnetic dipole radiation
from dust grains enriched by metallic iron or ferrimagnetic materials. This new
foreground we have identified is present at high galactic latitudes, and
potentially dominates over the expected $B$-mode polarization signal due to
primordial gravitational waves from inflation.",1404.1899v3
2014-04-28,Electronic structure and magnetic properties of L1_0 binary alloys,"We present a systematic study of the magnetic properties of L1$_0$ binary
alloys FeNi, CoNi, MnAl and MnGa via two different density functional theory
approaches. Our calculations show large magnetocrystalline anisotropies in the
order $1~\text{MJ/m}^3$ or higher for CoNi, MnAl and MnGa while FeNi shows a
somewhat lower value in the range $0.48 - 0.77 ~\text{MJ/m}^3$. Saturation
magnetization values of $1.3~\text{MA/m}$, $1.0~\text{MA/m}$, $0.8~\text{MA/m}$
and $0.9~\text{MA/m}$ are obtained for FeNi, CoNi, MnAl and MnGa respectively.
Curie temperatures are evaluated via Monte Carlo simulations and show
$T_\text{C}=916~\text{K}$ and $T_\text{C}=1130~\text{K}$ for FeNi and CoNi
respectively. For Mn-based compounds Mn-rich off-stoichiometric compositions
are found to be important for the stability of a ferro or ferrimagnetic ground
state with $T_\text{C}$ greater than $600~\text{K}$. The effect of
substitutional disorder is studied and found to decrease both
magnetocrystalline anisotropies and Curie temperatures in FeNi and CoNi.",1404.7097v2
2014-07-12,Possible Half Metallic Antiferromagnetism in a Double Perovskite Material with Strong Spin-Orbit Couplings,"Using the first-principles density functional approach, we investigate a
material Pr$_2$MgIrO$_6$ (PMIO) of double perovskite structure synthesized
recently. According to the calculations, PMIO is a magnetic Mott-Hubbard
insulator influenced by the cooperative effect of spin-orbit coupling (SOC) and
Coulomb interactions of Ir-5$d$ and Pr-4$f$ electrons, as well as the crystal
field. When Pr is replaced with Sr gradually, the system exhibits half metallic
(HM) states desirable for spintronics applications. In
[Pr$_{2-x}$Sr$_x$MgIrO$_6$]$_2$, HM antiferromagnetism (HMAFM) with zero spin
magnetization in the unit cell is obtained for $x=1$, whereas for $x=0.5$ and
1.5 HM ferrimagnetism (HMFiM) is observed with $\mu_{\rm tot}=3\mu_{\rm B}$ and
$\mu_{\rm tot}=-3\mu_{\rm B}$ per unit cell respectively. It is emphasized that
the large exchange splitting between spin-up and spin-down bands at the Fermi
level makes the half metallicity possible even with strong SOC.",1407.3408v1
2014-07-17,Ferroelectric and Magnetic Domains in LuFe2O4 Observed by Scanning Probe Microscopy,"LuFe2O4 is a multiferroic system which exhibits ferroelectricity, charge
order, and ferrimagnetic order simultaneously below ~230 K. The ferroelectric
domains of LuFe2O4 are imaged with both piezoresponse force microscopy (PFM)
and electrostatic force microscopy (EFM), while the magnetic domains are
characterized by magnetic force microscopy (MFM). Comparison of PFM and EFM
results lead to a conclusion that the ferroelectricity is of electronic origin
as opposed to the usual displacive one. Simultaneous characterization of
ferroelectric and magnetic domains by EFM and MFM, respectively, on the same
surface of LuFe2O4 reveals that both domains have irregular patterns of similar
shape, but the length scales are quite different. The domain size is
approximately 100 nm for the ferroelectric domains while the magnetic domain
size is much larger and gets as large as 1{\mu}m. We also demonstrate that the
origin of the formation of irregular domains in LuFe2O4 is not extrinsic but
intrinsic.",1407.4536v1
2014-08-10,Thermodynamic curvature for a two-parameter spin model with frustration,"Microscopic models of realistic thermodynamic systems usually involve a
number of parameters, not all of equal macroscopic relevance. We examine a
decorated $(1+3)$ Ising spin chain containing two microscopic parameters: a
""stiff"" $K$ mediating the long-range interactions, and a ""sloppy"" $J$ operating
within local spin groups. $K$ dominates the macroscopic behavior, and varying
$J$ has weak effect except in regions where $J$ brings about transitions
between phases through its conditioning of the local spin groups with which $K$
interacts. We calculate the heat capacity $C_H$, the magnetic susceptibility
$\chi_T$, and the thermodynamic curvature $R$. For large $|J/K|$, we identify
four magnetic phases: ferromagnetic, antiferromagnetic, and two ferrimagnetic
ones, according to the signs of $K$ and $J$. We argue that for characterizing
these phases, the strongest picture is offered by the thermodynamic geometric
invariant $R$, proportional to the correlation length $\xi$. This picture has
correspondences to other cases, such as fluids.",1408.2236v1
2014-08-26,Exotic magnetic phases in an Ising-spin Kondo lattice model on a kagome lattice,"Magnetic and electronic states of an Ising-spin Kondo lattice model on a
kagome lattice are investigated by a Monte Carlo simulation. In addition to the
conventional ferromagnetic and ferrimagnetic orders, we show that this model
exhibits several thermally-induced phases, such as partially disordered,
Kosteritz-Thouless-like, and loop-liquid states. In the partially disordered
state, we show that the magnetic transition is associated with the charge-gap
formation. We find that the density of state shows characteristic peaks
reflecting the underlying spin texture. In the loop-liquid state, we also find
a peak in a different manner in the density of states as well as in the optical
conductivity. This is a consequence of the formation of closed loops of the
same spin sites in the loop-liquid state. Our results elucidates the peculiar
cooperation between thermal fluctuations and the spin-charge interplay in this
frustrated itinerant electron system.",1408.5998v2
2014-09-15,Frustration and Dzyaloshinsky-Moriya anisotropy in the kagome francisites Cu$_3$Bi(SeO$_3)_2$O$_2$X,"We investigate the antiferromagnetic canting instability of the spin-1/2
kagome ferromagnet, as realized in the layered cuprates
Cu$_3$Bi(SeO$_3)_2$O$_2$X (X=Br, Cl, and I). While the local canting can be
explained in terms of competing exchange interactions, the direction of the
ferrimagnetic order parameter fluctuates strongly even at short distances on
account of frustration which gives rise to an infinite ground state degeneracy
at the classical level. In analogy with the kagome antiferromagnet, the
accidental degeneracy is fully lifted only by non-linear 1/S corrections,
rendering the selected uniform canted phase very fragile even for spins-1/2, as
shown explicitly by coupled-cluster calculations. To account for the observed
ordering, we show that the minimal description of these systems must include
the microscopic Dzyaloshinsky-Moriya interactions, which we obtain from
density-functional band-structure calculations. The model explains all
qualitative properties of the kagome francisites, including the detailed nature
of the ground state and the anisotropic response under a magnetic field. The
predicted magnon excitation spectrum and quantitative features of the
magnetization process call for further experimental investigations of these
compounds.",1409.4335v1
2015-01-06,Microstructural Effects of Chemical Island Templating in Patterned Matrix-Pillar Oxide Nanocomposites,"The ability to pattern the location of pillars in epitaxial matrix-pillar
nanocomposites is a key challenge to develop future technologies using these
intriguing materials. One such model system employs a ferrimagnetic
CoFe$_{2}$O$_{4}$ (CFO) pillar embedded in a ferroelectric BiFeO$_{3}$ (BFO)
matrix, which has been proposed as a possible memory or logic system. These
composites self-assemble spontaneously with pillars forming through nucleation
at a random location when grown via physical vapor deposition. Recent results
have shown that if an island of the pillar material is pre-patterned on the
substrate, it is possible to control the nucleation process and determine the
locations where pillars form. In this work, we employ electron microscopy and
x-ray diffraction to examine the chemical composition and microstructure of
patterned CFO-BFO nanocomposites. Cross-sectional transmission electron
microscopy is used to examine the nucleation effects at the interface between
the template island and resulting pillar.Evidence of grain boundaries and
lattice tilting in the templated pillars is also presented and attributed to
the microstructure of the seed island.",1501.01061v2
2015-01-12,Anomalous Hall effect in YIG$|$Pt bilayers,"We measure the ordinary and the anomalous Hall effect in a set of yttrium
iron garnet$|$platinum (YIG$|$Pt) bilayers via magnetization orientation
dependent magnetoresistance experiments. Our data show that the presence of the
ferrimagnetic insulator YIG leads to an anomalous Hall like signature in Pt,
sensitive to both Pt thickness and temperature. Interpretation of the
experimental findings in terms of the spin Hall anomalous Hall effect indicates
that the imaginary part of the spin mixing interface conductance
$G_{\mathrm{i}}$ plays a crucial role in YIG$|$Pt bilayers. In particular, our
data suggest a sign change in $G_{\mathrm{i}}$ between $10\,\mathrm{K}$ and
$300\,\mathrm{K}$. Additionally, we report a higher order Hall effect, which
appears in thin Pt films on YIG at low temperatures.",1501.02574v3
2015-01-28,Spin Seebeck devices using local on-chip heating,"A micro-patterned spin Seebeck device is fabricated using an on-chip heater.
Current is driven through a Au heater layer electrically isolated from a
bilayer consisting of Fe$_3$O$_4$ (insulating ferrimagnet) and a spin detector
layer. It is shown that through this method it is possible to measure the
longitudinal spin Seebeck effect (SSE) for small area magnetic devices,
equivalent to traditional macroscopic SSE experiments. Using a lock-in
detection technique it is possible to more sensitively characterize both the
SSE and the anomalous Nernst effect (ANE), as well as the inverse spin Hall
effect in various spin detector materials. By using the spin detector layer as
a thermometer, we can obtain a value for the temperature gradient across the
device. These results are well matched to values obtained through
electromagnetic/thermal modeling of the device structure and with large area
spin Seebeck measurements.",1501.07599v1
2015-01-30,Fragility of ferromagnetic double exchange interactions and pressure tuning of magnetism in 3d-5d double perovskite Sr2FeOsO6,"The ability to tune exchange (magnetic) interactions between 3d transition
metals in perovskite structures has proven to be a powerful route to discovery
of novel properties. Here we demonstrate that the introduction of 3d-5d
exchange pathways in double perovskites enables additional tunability, a result
of the large spatial extent of 5d wave functions. Using x-ray probes of
magnetism and structure at high pressure, we show that compression of Sr2FeOsO6
drives an unexpected continuous change in the sign of Fe-Os exchange
interactions and a transition from antiferromagnetic to ferrimagnetic order. We
analyze the relevant electron-electron interactions, shedding light into
fundamental differences with the more thoroughly studied 3d-3d systems.",1501.07889v2
2015-02-22,Excitation and detection of propagating spin waves at the single magnon level,"Ferro- and ferrimagnets play host to small-signal, microwave-frequency
magnetic excitations called spin waves, the quanta of which are known as
magnons. Over the last decade, the field of spin-wave dynamics has contributed
much to our understanding of fundamental magnetism. To date, experiments have
focussed overwhelmingly on the study of room-temperature systems within
classical limits. Here we demonstrate, for the first time, the excitation and
detection of propagating spin waves at the single magnon level. Our results
allow us to project that coupling of propagating spin-wave excitations to
quantum circuits is achievable, enabling fundamental quantum-level studies of
magnon systems and potentially opening doors to novel hybrid quantum
measurement and information processing devices.",1502.06263v1
2015-03-01,"A combined first-principles and thermodynamic approach to M-Nitronyl Nitroxide (M=Co, Mn) spin helices","The properties of two molecular-based magnetic helices, composed of 3$d$
metal Co and Mn ions bridged by Nitronyl Nitroxide radicals, are investigated
by density functional calculations. Their peculiar and distinctive magnetic
behavior is here elucidated by a thorough description of their magnetic,
electronic, and anisotropy properties. Metal ions are antiferromagnetically
coupled with the radicals, leading to a ferrimagnetically ordered ground state.
A strong metal-radical exchange coupling is found, about 44 meV and 48 meV for
Co- and Mn-helices, respectively. The latter have also relevant
next-nearest-neighbor Mn-Mn antiferromagnetic interactions (of $\sim$ 6 meV).
Co-sites are characterized by non-collinear uniaxial anisotropies, whereas
Mn-sites are rather isotropic. A key result pertains to the Co-helix: the
microscopic picture resulting from density-functional calculations allows us to
propose a spin Hamiltonian of increased complexity with respect to the commonly
employed Ising Hamiltonian, suitable for the study of finite-temperature
behavior, and that seems to clarify the puzzling scenario of multiple
characteristic energy scales observed in experiments.",1503.00292v1
2015-04-16,Experimental Observation of Large Chern numbers in Photonic Crystals,"Despite great interest in the quantum anomalous Hall phase and its analogs,
all experimental studies in electronic and bosonic systems have been limited to
a Chern number of one. Here, we perform microwave transmission measurements in
the bulk and at the edge of ferrimagnetic photonic crystals. Bandgaps with
large Chern numbers of 2, 3, and 4 are present in the experimental results
which show excellent agreement with theory. We measure the mode profiles and
Fourier transform them to produce dispersion relations of the edge modes, whose
number and direction match our Chern number calculations.",1504.04399v2
2015-05-01,"Half-metallic state and magnetic properties versus the lattice constant in Zr2RhZ (Z = Al, Ga, In) Heusler alloys","The half metallic and magnetic properties of Zr2RhZ (Z = Al, Ga, In) alloys
with an Hg2CuTi-type structure were systematically investigated using the
first-principle calculations. Zr2RhZ (Z = Al, Ga, In) alloys are predicted to
be half-metallic ferrimagnets at their equilibrium lattice constants. The
Zr2Rh-based alloys have Mt (the total magnetic moment per unit cell) and Zt
(the valence concentration) values that in agreement with Slater-Pauling rule
Mt = Zt -18. The half-metallic properties and the magnetic properties at
different lattice constants are discussed in detail. We expect that our results
may trigger Zr2RhZ (Z = Al, Ga, In) applying in the future spintronics field.",1505.00203v1
2015-05-08,Nonreciprocal magnon propagation in a noncentrosymmetric ferromagnet,"Relativistic spin-orbit interaction drastically modifies electronic band and
endows emergent functionalities. One of the example is the Rashba effect. In
noncentrosymmetric systems such as interface and polar materials, the
electronic band is spin-splitted depending on the momentum direction owing to
the spin-orbit interaction, which is useful for the electric manipulation of
spin current. Similar relativistic band-modification is also emergent for spin
wave (magnon) in magnetic materials. The asymmetric magnon band dispersion
induced by the Dzyaloshinskii-Moriya interaction, which is antisymmetric
exchange interaction originating from the spin-orbit interaction, is
theoretically expected, and experimentally observed recently in
noncentrosymmetric ferromagnets. Here, we demonstrate that the nonreciprocal
microwave response can be induced by the asymmetric magnon band in a
noncentrosymmetric ferrimagnet LiFe$_5$O$_8$. This result may pave a new path
to designing magnonic device based on the relativistic band engineering.",1505.01942v1
2015-05-19,"An orbital glass state of a nearly metallic spinel, CoV$_2$O$_4$","Strain, magnetization, and unpolarized and polarized neutron diffraction
measurements were performed to study the magnetic and structural properties of
spinel CoV$_{2}$O$_{4}$. Magnetostriction measurements indicate that a subtle
distortion of the crystal along the direction of magnetization, $\Delta L/L
\sim 10^{-4}$, exists and varies from elongation to contraction in a second
order fashion upon cooling. Unpolarized and polarized single-crystal neutron
experiments indicate that upon cooling the ferrimagnetic structure changes from
collinear to noncollinear at $T \sim 90$ K, where the elongation of the crystal
is maximized. These results imply the existence of an orbital glassy state in
the nearly metallic frustrated magnet CoV$_{2}$O$_{4}$.",1505.04864v1
2015-07-01,Three-dimensional topological photonic crystal with a single surface Dirac cone,"A single Dirac cone on the surface is the hallmark of three-dimensional (3D)
topological insulators, where the double degeneracy at the Dirac point is
protected by time-reversal symmetry and the spin-splitting away from the point
is provided by the spin-orbital coupling. Here we predict a single Dirac-cone
surface state in a 3D photonic crystal, where the degeneracy at the Dirac point
is protected by a nonsymmorphic glide reflection and the linear splitting away
from it is enabled by breaking time-reversal symmetry. Such a gapless surface
state is fully robust against random disorder of any type. This bosonic
topological band structure is achieved by applying alternating magnetization to
gap out the 3D ""generalized Dirac points"" discovered in the bulk of our
crystal. The $Z_2$ bulk invariant is characterized through the evolution of
Wannier centers. Our proposal--readily realizable using ferrimagnetic materials
at microwave frequencies--can also be regarded as the photonic analog of
topological crystalline insulators, providing the first 3D bosonic
symmetry-protected topological system.",1507.00337v1
2015-07-06,Spin-Hall magnetoresistance and spin Seebeck effect in spin-spiral and paramagnetic phases of multiferroic CoCr2O4 films,"We report on the spin-Hall magnetoresistance (SMR) and spin Seebeck effect
(SSE) in multiferroic CoCr2O4 (CCO) spinel thin films with Pt contacts. We
observe a large enhancement of both signals below the spin-spiral (Ts = 28 K)
and the spin lock-in transitions (T_{lock_in} = 14 K). The SMR and SSE response
in the spin lock-in phase are one order of magnitude larger than those observed
at the ferrimagnetic transition temperature (Tc = 94 K), which indicates that
the interaction between spins at the Pt|CCO interface is more efficient in the
non-collinear magnetic state below Ts and T_{lock-in}. At T > Tc, magnetic
field-induced SMR and SSE signals are observed, which can be explained by a
high interface susceptibility. Our results show that the spin transport at the
Pt|CCO interface is sensitive to the magnetic phases but cannot be explained
solely by the bulk magnetization.",1507.01352v1
2015-07-09,Structural transition and orbital glass physics in near itinerant CoV2O4,"The ferrimagnetic spinel $\mathrm{CoV_2O_4}$ has been a topic of intense
recent interest, both as a frustrated insulator with unquenched orbital
degeneracy and as a near-itinerant magnet which can be driven metallic with
moderate applied pressure. Here, we report on our recent neutron diffraction
and inelastic scattering measurements on powders with minimal cation site
disorder. Our main new result is the identification of a weak ($\frac{\Delta
a}{a} \sim 10^{-4}$), first order structural phase transition at $T^*$ = 90 K,
the same temperature where spin canting was seen in recent single crystal
measurements. This transition is characterized by a short-range distortion of
oxygen octahedral positions, and inelastic data further establish a weak
$\Delta\sim 1.25 meV$ spin gap at low temperature. Together, these findings
provide strong support for the local orbital picture and the existence of an
orbital glass state at temperatures below $T^*$.",1507.02572v2
2015-07-12,On a mechanism of high-temperature superconductivity: Spin-electron acoustic wave as a mechanism for the Cooper pair formation,"We have found the mechanism of the electron Cooper pair formation via the
electron interaction by means of the spin-electron acoustic waves. This
mechanism takes place in metals with rather high spin polarization, like
ferromagnetic, ferrimagnetic and antiferromagnetic materials. The spin-electron
acoustic wave mechanism leads to transition temperatures 100 times higher than
the transition temperature allowed by the electron-phonon interaction.
Therefore, spin-electron acoustic waves give the explanation for the
high-temperature superconductivity. We find that the transition temperature has
strong dependence on the electron concentration and the spin polarization of
the electrons.",1507.03295v2
2015-07-30,"First principle investigations of the structural, electronic and magnetic properties of the new zirconium based full-Heusler compounds, Zr2MnZ (Z = Al, Ga and In)","The crystal structure, electronic and magnetic properties of the new
full-Heusler compounds Zr2MnZ (Z=Al, Ga, In), were studied within the Density
Functional Theory (DFT) framework. The materials exhibit unique properties that
connect the spin gapless semiconducting character with the completely
compensated ferrimagnetism. In magnetic configurations, Zr2MnZ (Z=Al, Ga, In)
crystallize in inverse Heusler structure, are stable against decomposition and
have zero magnetic moment per formula unit properties, in agreement with
Slater-Pauling rule. The Zr2MnAl compound presents spin gapless semiconducting
properties with a energy band gap of 0.41 eV in the majority spin channel and a
zero band gap in the minority spin channel. By substituting Ga or In elements,
for Al in Zr2MnAl, semiconducting pseudo band gaps are formed in the majority
spin channels due to the different neighborhood around the manganese atoms,
which decreases the energy of Mn's triple degenerated anti-bonding states.",1507.08605v2
2015-08-10,Field induced metamagnetic transitions in quasi-one-dimensional Ising spin chain CoV$_{2}$O$_{6}$,"We have investigated the temperature and magnetic field dependence of
magnetization ($M$), specific heat ($C_p$), and relative sample length change
($\Delta L/L_0$) for understanding the field-induced metamagnetic transitions
in quasi-one-dimensional monoclinic ($\alpha$ phase) and triclinic ($\gamma$
phase) CoV$_2$O$_6$ spin chains. With the application of external magnetic
field, a sharp peak emerges in $C_p$($T$) below $T_N$$=$15 K in $\alpha$ phase
and a hump-like feature appears above $T_N$$=$6.5 K in $\gamma$ phase due to
the field-induced ferrimagnetic and ferromagnetic transitions, respectively.
Strong field dependence of linear thermal expansion and large positive
magnetostriction have been observed in $\alpha$ phase. Though magnetization
data indicate strong spin-orbit coupling for both phases, other measurements
show that this effect is very weak for the $\gamma$ phase.",1508.02269v1
2015-08-12,Kinetic Arrest of Field-Temperature Induced First Order Phase Transition in Quasi- One Dimensional Spin System Ca3Co2O6,"We have found that the geometrically frustrated spin chain compound Ca3Co2O6
belonging to Ising like universality class with uniaxial anisotropy shows
kinetic arrest of first order intermediate phase (IP) to ferrimagnetic (FIM)
transition. In this system, dc magnetization measurements followed by different
protocols suggest the coexistence of high temperature IP with equilibrium FIM
phase in low temperature. Formation of metastable state due to hindered first
order transition has also been probed through cooling and heating in unequal
field (CHUF) protocol. Kinetically arrested high temperature IP appears to
persist down to almost the spin freezing temperature in this system.",1508.02894v1
2015-09-04,Origin of lowered magnetic moments in epitaxially strained thin films of multiferroic Bi$_2$FeCrO$_6$,"We have investigated the effect of epitaxial strain on the magnetic
properties and $B$-site cation ordering in multiferroic Bi$_2$FeCrO$_6$ (001)
thin films using a density-functional theory approach. We find that in thin
films with rock-salt ordering of Fe and Cr the ground state is characterised by
C-type anti-ferromagnetic (AFM) order. This is in contrast to the bulk form of
the material which was predicted to be a ferrimagnet with G-type AFM order.
Furthermore, the cation ordered thin-films undergo a transition with epitaxial
strain from C to A-type AFM order. Other magnetic orders appear as thermally
accessible excited states. We also find that $B$-site cation disordered
structures are more stable in coherent epitaxial strains thereby explaining the
lowered magnetic moments observed in these samples at room temperature. Strain
varies both the sign as well as strength of the Fe-Cr superexchange coupling
resulting in a very interesting phase diagram for Bi$_2$FeCrO$_6$ thin films.",1509.01563v2
2015-09-04,Spin frustration and fermionic entanglement in an exactly solved hybrid diamond chain with the localized Ising spins and mobile electrons,"The strongly correlated spin-electron system on a diamond chain containing
localized Ising spins on its nodal lattice sites and mobile electrons on its
interstitial sites is exactly solved in a magnetic field using the
transfer-matrix method. We have investigated in detail all available ground
states, the magnetization processes, the spin-spin correlation functions around
an elementary plaquette, fermionic quantum concurrence and spin frustration. It
is shown that the fermionic entanglement between mobile electrons hopping on
interstitial sites and the kinetically-induced spin frustration are closely
related yet independent phenomena. In the ground state, quantum entanglement
only appears within a frustrated unsaturated paramagnetic phase, while thermal
fluctuations can promote some degree of quantum entanglement above the
non-frustrated ground states with saturated paramagnetic or classical
ferrimagnetic spin arrangements.",1509.01639v1
2015-09-05,Magnetic and magnetocaloric properties of quasi-one-dimensional Ising spin chain CoV$_{2}$O$_{6}$,"We have investigated the magnetic and magnetocaloric properties of
antiferromagnetic Ising spin chain CoV$_{2}$O$_{6}$ by magnetization and heat
capacity measurements. Both monoclinic $\alpha$-CoV$_{2}$O$_{6}$ and triclinic
$\gamma$-CoV$_{2}$O$_{6}$ exhibit field-induced metamagnetic transition from
antiferromagnetic to ferromagnetic state via an intermediate ferrimagnetic
state with 1/3 magnetization plateau. Due to this field-induced metamagnetic
transition, these systems show large conventional as well as inverse
magnetocaloric effects. In $\alpha$-CoV$_{2}$O$_{6}$, we observe field-induced
complex magnetic phases and multiple magnetization plateaux at low temperature
when the field is applied along $c$ axis. Several critical temperatures and
fields have been identified from the temperature and field dependence of
magnetization, magnetic entropy change and heat capacity to construct the
$H$-$T$ phase diagram. As compared to $\alpha$-CoV$_{2}$O$_{6}$,
$\gamma$-CoV$_{2}$O$_{6}$ displays a relatively simple magnetic phase diagram.
Due to the large magnetic entropy change and adiabatic temperature change at
low or moderate applied magnetic field, $\gamma$-CoV$_{2}$O$_{6}$ may be
considered as a magnetic refrigerant in the low-temperature region.",1509.01690v2
2015-09-09,"Large magneto-optical Kerr effect in noncollinear antiferromagnets Mn$_{3}X$ ($X$ = Rh, Ir, or Pt)","Magneto-optical Kerr effect, normally found in magnetic materials with
nonzero magnetization such as ferromagnets and ferrimagnets, has been known for
more than a century. Here, using first-principles density functional theory, we
demonstrate large magneto-optical Kerr effect in high temperature noncollinear
antiferromagnets Mn$_{3}X$ ($X$ = Rh, Ir, or Pt), in contrast to usual wisdom.
The calculated Kerr rotation angles are large, being comparable to that of
transition metal magnets such as bcc Fe. The large Kerr rotation angles and
ellipticities are found to originate from the lifting of the band
double-degeneracy due to the absence of spatial symmetry in the Mn$_{3}X$
noncollinear antiferromagnets which together with the time-reversal symmetry
would preserve the Kramers theorem. Our results indicate that Mn$_{3}X$ would
provide a rare material platform for exploration of subtle magneto-optical
phenomena in noncollinear magnetic materials without net magnetization.",1509.02865v1
2015-09-14,Competing Magnetic Orderings and Tunable Topological States in Two-Dimensional Hexagonal Organometallic Lattices,"The exploration of topological states is of significant fundamental and
practical importance in contemporary condensed matter physics, for which the
extension to two-dimensional (2D) organometallic systems is particularly
attractive. Using first-principles calculations, we show that a 2D hexagonal
triphenyl-lead lattice composed of only main group elements is susceptible to a
magnetic instability, characterized by a considerably more stable
antiferromagnetic (AFM) insulating state rather than the topologically
nontrivial quantum spin Hall state proposed recently. Even though this AFM
phase is topologically trivial, it possesses an intricate emergent degree of
freedom, defined by the product of spin and valley indices, leading to Berry
curvature-induced spin and valley currents under electron or hole doping.
Furthermore, such a trivial band insulator can be tuned into a topologically
nontrivial matter by the application of an out-of-plane electric field, which
destroys the AFM order, favoring instead ferrimagnetic spin ordering and a
quantum anomalous Hall state with a non-zero topological invariant. These
findings further enrich our understanding of 2D hexagonal organometallic
lattices for potential applications in spintronics and valleytronics.",1509.03921v1
2015-10-19,Ferroelectric polarization switching with a remarkably high activation-energy in orthorhombic GaFeO3 thin films,"Orthorhombic GaFeO3 (o-GFO) with the polar Pna21 space group is a prominent
ferrite by virtue of its piezoelectricity and ferrimagnetism, coupled with
magneto-electric effects. Herein, we unequivocally demonstrate a large
ferroelectric remanent polarization in undoped o-GFO thin films by adopting
either a hexagonal strontium titanate (STO) or a cubic yttrium-stabilized
zirconia (YSZ) substrate. The polarization-electric-field hysteresis curves of
the polar c-axis-grown o-GFO film on a SrTiO3/STO substrate show the net
switching polarization of ~35 {\mu}C/cm2 with an unusually high coercive field
of +-1400 kV/cm at room temperature. The PUND measurement also demonstrates the
switching polarization of ~26 {\mu}C/cm2. The activation energy for the
polarization switching, as obtained by density-functional theory calculations,
is remarkably high, 1.05 eV per formula unit. This high value accounts for the
observed stability of the polar Pna21 phase over a wide range of temperature up
to 1368 K.",1510.05359v1
2016-01-03,Detection of DC currents and resistance measurements in longitudinal spin Seebeck effect experiments on Pt/YIG and Pt/NFO,"In this work we investigated thin films of the ferrimagnetic insulators YIG
and NFO capped with thin Pt layers in terms of the longitudinal spin Seebeck
effect (LSSE). The electric response detected in the Pt layer under an
out-of-plane temperature gradient can be interpreted as a pure spin current
converted into a charge current via the inverse spin Hall effect. Typically,
the transverse voltage is the quantity investigated in LSSE measurements (in
the range of \mu V). Here, we present the directly detected DC current (in the
range of nA) as an alternative quantity. Furthermore, we investigate the
resistance of the Pt layer in the LSSE configuration. We found an influence of
the test current on the resistance. The typical shape of the LSSE curve varies
for increasing test currents.",1601.00304v1
2016-01-20,Alternating-spin S=3/2 and sigma=1/2 Heisenberg chain with three-body exchange interactions,"The promotion of collinear classical spin configurations as well as the
enhanced tendency towards nearest-neighbor clustering of the quantum spins are
typical features of the frustrating isotropic three-body exchange interactions
in Heisenberg spin systems. Based on numerical density-matrix renormalization
group calculations, we demonstrate that these extra interactions in the
Heisenberg chain constructed from alternating S=3/2 and sigma=1/2 site spins
can generate numerous specific quantum spin states, including some
partially-polarized ferrimagnetic states as well as a doubly-degenerate
non-magnetic gapped phase. In the non-magnetic region of the phase diagram, the
model describes a crossover between the spin-1 and spin-2 Haldane-type states.",1601.05319v1
2016-02-12,Transport and spin conversion of multi-carriers in semimetal bismuth,"In this paper, we report on the investigation of (1) the transport properties
of multi-carriers in semi-metal Bi and (2) the spin conversion physics in this
semimetal system in a ferrimagnetic insulator, yttrium-iron-garnet. Hall
measurements reveal that electrons and holes co-exist in the Bi, with electrons
being the dominant carrier. The results of a spin conversion experiment
corroborate the results of the Hall measurement; in addition, the inverse spin
Hall effect governs the spin conversion in the semimetal/insulator system. This
study provides further insights into spin conversion physics in semimetal
systems.",1602.03953v1
2016-02-12,Thermal generation of spin current in a helimagnetic multiferroic hexaferrite,"We report the experimental observation of longitudinal spin Seebeck effect in
a multiferroic helimagnet Ba0.5Sr1.5Zn2Fe12O22. Temperature gradient applied
normal to Ba0.5Sr1.5Zn2Fe12O22/Pt interface generates inverse spin Hall voltage
of spin current origin in Pt, whose magnitude was found to be proportional to
bulk magnetization of Ba0.5Sr1.5Zn2Fe12O22 even through the successive magnetic
transitions among various helimagnetic and ferrimagnetic phases. This finding
demonstrates that the helimagnetic spin wave can be an effective carrier of
spin current. By controlling the population ratio of spin-helicity domains
characterized by clockwise/counter-clockwise manner of spin rotation with use
of poling electric field in the ferroelectric helimagnetic phase, we found that
spin-helicity domain distribution does not affect the magnitude of spin current
injected into Pt. The results suggest that the spin-wave spin current is rather
robust against the spin-helicity domain wall, unlike the case with the
conventional ferromagnetic domain wall.",1602.04011v1
2016-02-17,Quantum Rotors on the AB$_2$ Chain with Competing Interactions,"We present the ground state phase diagram of $q = 1/2$ quantum-rotor chains
with competing interactions (frustration) calculated through cluster
variational mean field approaches. We consider two interaction patterns, named
F$_1$ and F$_2$ models, between the quantum-rotor momentum and position
operators, which follow exchange patterns of known one-dimensional spin-1/2
systems with a ferrimagnetic state in their phase diagrams. The spin-1/2 F$_1$
model is known as the diamond chain and is related to the azurite compound,
while the spin-1/2 F$_2$ model was recently shown to present a
frustration-induced condensation of magnons. We provide a detailed comparison
between the quantum-rotor phase diagrams, in single- and multi-site mean-field
approaches, and known results for the spin-1/2 models, including exact
diagonalization and density matrix renormalization group data for these
systems, as well as phase diagrams of the associated classical models.",1602.05383v1
2016-02-25,Study of the ultrafast dynamics of ferromagnetic materials with a Quantum Monte Carlo atomistic model,"We study of the ultrafast dynamics of the atomic angular momentum in
ferrimagnets irradiated by laser pulses. My apply a quantum atomistic spin
approach based on the Monte Carlo technique. Our model describes the coherent
transfer of angular momentum between the spin and the orbital momentum as well
as the quenching of the orbital momentum induced by the lattice field. The
Elliott-Yafet collision mechanism is also included. We focus on elementary
mechanisms that lead to the dissipation of the total angular momentum in a rare
earth-transition metal (RE-TM) alloy in which the two sublattices have opposite
spin orientation. Our model shows that the observed ultrafast quenching of the
magnetization can be explained microscopically by the transfer of spin between
the sublattices and by the quenching of the localized orbital angular momentum.",1602.07950v1
2016-03-10,Engineering charge ordering into multiferroicity,"Multiferroic materials have attracted great interests but are rare in nature.
In many transitional metal oxides, charge ordering and magnetic ordering
coexist, so that a method of engineering charge-ordered materials into
ferroelectric materials would lead to a large class of multiferroic materials.
We propose a strategy for designing new ferroelectric or even multiferroic
materials by inserting a spacing layer into each two layers of charge-ordered
materials and artificially making a superlattice. One example of the model
demonstrated here is the perovskite (LaFeO$_3$)$_2$/LaTiO$_3$ (111)
superlattice, in which the LaTiO$_3$ layer acts as the donor and the spacing
layer, and the LaFeO$_3$ layer is half doped and performs charge ordering. The
collaboration of the charge ordering and the spacing layer breaks the space
inversion symmetry, resulting in a large ferroelectric polarization. As the
charge ordering also leads to a ferrimagnetic structure, the
(LaFeO$_3$)$_2$/LaTiO$_3$ is multiferroic. It is expected that this work can
encourage the designing and experimentally implementation of a large class of
multiferroic structures with novel properties.",1603.03253v1
2016-03-22,Contributions to the Monte Carlo study of the magnetic properties of nanomaterials such as graphyne and graphone,"Attracted by the importance of new materials in nanotechnology area, this
thesis develops this research field while deepening results. We started by
introducing the more sophisticated simulation and calculation methods, such as
the Monte Carlo method, the mean field theory, the effectif field theory and
the transfer matrix. Subsequently, we studied the magnetic and hysteretic
properties of the materials. Then we have detailed some of our contributions
related to the materials based on graphene and ferrimagnetic nanomaterials with
different morphologies. We discussed the effect of defects on the thermodynamic
properties of these novel materials. Particular attention was paid to the
physical parameters that influence the compensation behavior that is of crucial
importance for technological applications such as thermo-optical recording.
With all these elements, we are opened ourselves up to the latest developments
in physics of new materials. Finally, we finished with the conclusion and
perspectives.",1603.06766v1
2016-03-28,"Ab initio Studies on Electronic and Magnetic Properties of X$_{2}$PtGa (X = Cr, Mn, Fe, Co) Heusler Alloys","Using first-principles calculations based on density functional theory, we
probe the electronic and magnetic properties of X$_{2}$PtGa (X being Cr, Mn,
Fe, Co) Heusler alloys. Our calculations predict that all these systems possess
inverse Heusler alloy structure in their respective ground states. Application
of tetragonal distortion leads to lowering of energy with respect to the cubic
phase for all the materials. The equilibrium volumes of both the phases are
nearly the same. These results of our calculations indicate that all these
materials are prone to undergo martensite transition, as has been recently
shown theoretically for Mn$_{2}$PtGa in the literature. Ground state with a
tetragonal symmetry of these materials is supported by the observation of soft
tetragonal shear constants in their cubic phase. By comparing the energies of
various types of magnetic configurations of these alloys we predict that
Cr$_{2}$PtGa and Mn$_{2}$PtGa possess ferrimagnetic configuration whereas
Fe$_{2}$PtGa and Co$_{2}$PtGa possess ferromagneic configuration in their
respective ground states.",1603.08350v2
2016-03-31,Enhanced spin Seebeck effect signal due to spin-momentum locked topological surface states,"Spin-momentum locking in protected surface states enables efficient
electrical detection of magnon decay at a
magnetic-insulator/topological-insulator heterojunction. Here we demonstrate
this property using the spin Seebeck effect, i.e. measuring the transverse
thermoelectric response to a temperature gradient across a thin film of yttrium
iron garnet, an insulating ferrimagnet, and forming a heterojunction with
(BixSb1-x)2Te3, a topological insulator. The non-equilibrium magnon population
established at the interface can decay in part by interactions of magnons with
electrons near the Fermi energy of the topological insulator. When this decay
channel is made active by tuning (BixSb1-x)2Te3 to a bulk insulator, a large
electromotive force emerges in the direction perpendicular to the in-plane
magnetization of yttrium iron garnet. The enhanced, tunable spin Seebeck effect
which occurs when the Fermi level lies in the bulk gap offers unique advantages
over the usual spin Seebeck effect in metals and therefore opens up exciting
possibilities in spintronics.",1603.09427v1
2016-04-08,Gate-tunable spin-charge conversion and a role of spin-orbit interaction in graphene,"The small spin-orbit interaction of carbon atoms in graphene promises a long
spin diffusion length and potential to create a spin field-effect transistor.
However, for this reason, graphene was largely overlooked as a possible
spin-charge conversion material. We report electric gate tuning of the
spin-charge conversion voltage signal in a single-layer graphene. Using spin
pumping from yttrium iron garnet ferrimagnetic insulator and ionic liquid top
gate we determined that the inverse spin Hall effect is the dominant
spin-charge conversion mechanism in a single-layer graphene. From the gate
dependence of the electromotive force we showed dominance of the intrinsic over
Rashba spin-orbit interaction: a long-standing question in graphene research.",1604.02222v1
2016-04-25,Magnon based logic in a multi-terminal YIG/Pt nanostructure,"Boolean logic is the foundation of modern digital information processing.
Recently, there has been a growing interest in phenomena based on pure spin
currents, which allow to move from charge to spin based logic gates. We study a
proof-of-principle logic device based on the ferrimagnetic insulator Yttrium
Iron Garnet (YIG), with Pt strips acting as injectors and detectors for
nonequilibrium magnons. We experimentally observe incoherent superposition of
magnons generated by different injectors. This allows to implement a fully
functional majority gate, enabling multiple logic operations (AND and OR) in
one and the same device. Clocking frequencies of the order of several GHz and
straightforward down-scaling make our device promising for applications.",1604.07262v1
2016-05-21,Magnetic shielding and exotic spin-dependent interactions,"Experiments searching for exotic spin-dependent interactions typically employ
magnetic shielding between the source of the exotic field and the interrogated
spins. We explore the question of what effect magnetic shielding has on
detectable signals induced by exotic fields. Our general conclusion is that for
common experimental geometries and conditions, magnetic shields should not
significantly reduce sensitivity to exotic spin-dependent interactions,
especially when the technique of comagnetometry is used. However, exotic fields
that couple to electron spin can induce magnetic fields in the interior of
shields made of a soft ferro- or ferrimagnetic material. This induced magnetic
field must be taken into account in the interpretation of experiments searching
for new spin-dependent interactions and raises the possibility of using a flux
concentrator inside magnetic shields to amplify exotic spin-dependent signals.",1606.00696v1
2016-06-06,Switching field distribution of exchange coupled ferri-/ferromagnetic composite bit patterned media,"We investigate the switching field distribution and the resulting bit error
rate of exchange coupled ferri-/ferromagnetic bilayer island arrays by
micromagnetic simulations. Using islands with varying microstructure and
anisotropic properties, the intrinsic switching field distribution is computed.
The dipolar contribution to the switching field distribution is obtained
separately by using a model of a triangular patterned island array resembling
$1.4\,\mathrm{Tb/in}^2$ bit patterned media. Both contributions are computed
for different thickness of the soft exchange coupled ferrimagnet and also for
ferromagnetic single phase FePt islands. A bit patterned media with a bilayer
structure of FeGd($5\,\mathrm{nm}$)/FePt($5\,\mathrm{nm}$) shows a bit error
rate of $10^{-4}$ with a write field of $1.16\,\mathrm{T}$.",1606.01874v2
2016-06-23,Inversion of ferrimagnetic magnetization by ferroelectric switching via a novel magnetoelectric coupling,"Although several multiferroic materials/heterostructures have been
extensively studied, finding strong magnetoelectric couplings for the electric
field control of the magnetization remains challenging. Here, a novel
interfacial magnetoelectric coupling based on three components (ferroelectric
dipole, magnetic moment, and antiferromagnetic order) is analytically
formulated. As an extension of carrier-mediated magnetoelectricity, the new
coupling is shown to induce an electric-magnetic hysteresis loop. Realizations
employing BiFeO$_3$ bilayers grown along the [$111$] axis are proposed. Without
involving magnetic phase transitions, the magnetization orientation can be
switched by the carrier modulation driven by the field effect, as confirmed
using first-principles calculations.",1606.07203v1
2016-07-18,Monte Carlo simulations of an Ising bilayer with non-equivalent planes,"We study the thermodynamic and magnetic properties of an Ising bilayer
ferrimagnet. The system is composed of two interacting non-equivalent planes in
which the intralayer couplings are ferromagnetic while the interlayer
interactions are antiferromagnetic. Moreover, one of the planes is randomly
diluted. The study is carried out within a Monte Carlo approach employing the
multiple histogram reweighting method and finite-size scaling tools. The
occurrence of a compensation phenomenon is verified and the compensation
temperature, as well as the critical temperature for the model, are obtained as
functions of the Hamiltonian parameters. We present a detailed discussion of
the regions of the parameter space where the compensation effect is present or
absent. Our results are then compared to a mean-field-like approximation
applied to the same model by Balcerzak and Sza{\l}owski (2014). Although the
Monte Carlo and mean-field results agree qualitatively, our quantitative
results are significantly different.",1607.05221v2
2016-08-07,Ultrafast photo-magnetic recording in transparent medium,"Finding a conceptually new way to control the magnetic state of media with
the lowest possible production of heat and simultaneously at the fastest
possible time-scale is a new challenge in fundamental magnetism [1-4] as well
as an increasingly important issue in modern information technology [5]. Recent
results demonstrate that exclusively in metals it is possible to switch
magnetization between metastable states by femtosecond circularly polarized
laser pulses [6-8]. However, despite the record breaking speed of the
switching, the mechanisms in these materials are directly related to strong
optical absorption and laser-induced heating close to the Curie temperature
[9-12]. Here we report about ultrafast all-optical photo-magnetic recording in
transparent dielectrics. In ferrimagnetic garnet film a single linearly
polarized femtosecond laser pulse breaks the degeneracy between metastable
magnetic states and promotes switching of spins between them. Changing the
polarization of the laser pulse we deterministically steer the net
magnetization in the garnet, write ""0"" and ""1"" magnetic bits at will. This
mechanism operates at room temperature and allows ever fastest write-read
magnetic recording event (< 20 ps) accompanied by unprecedentedly low heat load
(< 6 J/cm3).",1609.05223v1
2016-09-20,Anomalous Hall hysteresis in Tm3Fe5O12/Pt with strain-induced perpendicular magnetic anisotropy,"We demonstrate robust interface strain-induced perpendicular magnetic
anisotropy in atomically flat ferrimagnetic insulator Tm3Fe5O12 films grown
with pulsed laser deposition on substituted-Gd3Ga5O12 substrate which maximizes
the tensile strain at the interface. In bilayers consisting of Pt and TIG, we
observe large squared Hall hysteresis loops over a wide range of thicknesses of
Pt at room temperature. When a thin Cu layer is inserted between Pt and TIG,
the Hall hysteresis magnitude decays but stays finite as the thickness of Cu
increases up to 5 nm. However, if the Cu layer is placed atop Pt instead, the
Hall hysteresis magnitude is consistently larger than when the Cu layer with
the same thickness is inserted in between for all Cu thicknesses. These results
suggest that both the proximity-induced ferromagnetism and spin current
contribute to the anomalous Hall effect.",1609.06367v1
2016-09-25,Quantum Spin Hall Effect in Twisted Bilayer Graphene,"Motivated by a recent experiment (Sanchez-Yamagishi et.al, arXiv:1602.06815)
reporting evidence of helical spin-polarized edge states in layer-biased
twisted bilayer graphene under a magnetic flux, we study the possibility of
stabilising a Quantum Spin Hall (QSH) phase in such a system, without Zeeman or
spin-orbit couplings, and with a QSH gap induced instead by electronic
interactions. We analyse how magnetic flux, electric field, interlayer rotation
angle, and interactions (treated at a mean field level) combine to produce a
pseudo-QSH with broken time-reversal symmetry, and spin-polarized helical edge
states. The effect is a consequence of a robust interaction-induced
ferrimagnetic ordering of the Quantum Hall ground state under an interlayer
bias, provided the two rotated layers are effectively decoupled at low
energies. We discuss in detail the electronic structure, and the constraints on
system parameters, such as the angle, interactions and magnetic flux, required
to reach the pseudo-QSH phase. We find, in particular, that purely local
electronic interactions are not sufficient to account for the experimental
observations, which demand at least nearest-neighbour interactions to be
included.",1609.07734v1
2016-09-27,Steady State and Dynamics of Joule Heating in Magnetic Tunnel Junctions Observed via the Temperature Dependence of RKKY Coupling,"Understanding quantitatively the heating dynamics in magnetic tunnel
junctions (MTJ) submitted to current pulses is very important in the context of
spin-transfer-torque magnetic random access memory development. Here we provide
a method to probe the heating of MTJ using the RKKY coupling of a synthetic
ferrimagnetic storage layer as a thermal sensor. The temperature increase
versus applied bias voltage is measured thanks to the decrease of the spin-flop
field with temperature. This method allows distinguishing spin transfer torque
(STT) effects from the influence of temperature on the switching field. The
heating dynamics is then studied in real-time by probing the conductance
variation due to spin-flop rotation during heating. This approach provides a
new method for measuring fast heating in spintronic devices, particularly
magnetic random access memory (MRAM) using thermally assisted or spin transfer
torque writing.",1609.08385v1
2016-09-29,"On the rich magnetic phase diagram of (Ni, Co)-Mn-Sn Heusler alloys","We put a spotlight on the exceptional magnetic properties of the metamagnetic
Heusler alloy (Ni,Co)-Mn-Sn by means of first principles simulations.
  In the energy landscape we find a multitude of local minima, which belong to
different ferrimagnetic states and are close in total magnetization and energy.
All these magnetic states correspond to the local high spin state of the Mn
atoms with different spin alignments and are related to the magnetic properties
of Mn. Compared to pure Mn, the magneto-volume coupling is reduced by Ni, Co,
and Sn atoms in the lattice and no local low-spin Mn states appear. For the
cubic phase we find a ferromagnetic ground state whereas the global energy
minimum is a tetragonal state with complicated spin structure and vanishing
magnetization which so far has been overlooked in simulations.",1609.09399v1
2016-09-30,The Tricritical Point of the f-electron Antiferromagnet USb2 Driven by High Magnetic Fields,"In pulsed magnetic fields up to 65T and at temperatures below the N\'eel
transition, our magnetization and magnetostriction measurements reveal a
field-induced metamagnetic-like transition that is suggestive of an
antiferromagnetic to polarized paramagnetic or ferrimagnetic ordering. Our data
also suggests a change in the nature of this metamagnetic-like transition from
second- to first-order-like near a tricritical point at T_{tc} ~145K and
H_{c}~52T. At high fields for H>H_{c} we found a decreased magnetic moment
roughly half of the moment reported in low field measurements. We propose that
\mathit{f-p} hybridization effects and magnetoelastic interactions drive the
decreased moment, lack of saturation at high fields, and the decreased phase
boundary.",1609.09845v1
2016-10-11,Magnetic gap opening in rhombohedral-stacked multilayer graphene from first principles,"We investigate the occurrence of magnetic and charge density wave
instabilities in rhombohedral-stacked multilayer (three to eight layers)
graphene by first principles calculations including exact exchange. Neglecting
spin-polarization, an extremely flat surface band centered at the special point
${\bf K}$ of the Brillouin zone occurs at the Fermi level. Spin polarization
opens a gap in the surface state by stabilizing an antiferromagnetic state. The
top and the bottom surface layers are weakly ferrimagnetic in-plane (net
magnetization smaller than $10^{-3}\mu_B$), and are antiferromagnetic coupled
to each other. This coupling is propagated by the out-of-plane
antiferromagnetic coupling between the nearest neighbors. The gap is very small
in a spin-polarized generalized gradient approximation, while it is
proportional to the amount of exact exchange in hybrid functionals. For
trilayer rhombohedral graphene it is $38.6$ meV in PBE0, in agreement with the
$42$ meV gap found in experiments. We study the temperature and doping
dependence of the magnetic gap. At electron doping of $n \sim 7 \times 10^{11}$
cm$^{-2}$ the gap closes. Charge density wave instabilities with
$\sqrt{3}\times\sqrt{3}$ periodicity do not occur.",1610.03445v2
2016-10-18,Magnetic properties of low-moment ferrimagnetic Heusler Cr2CoGa thin films grown by molecular beam epitaxy,"Recently, theorists have predicted many materials with a low magnetic moment
and large spin-polarization for spintronic applications. These compounds are
predicted to form in the inverse Heusler structure, however, many of these
compounds have been found to phase segregate. In this study, ordered Cr2CoGa
thin films were synthesized without phase segregation using molecular beam
epitaxy. The present as-grown films exhibit a low magnetic moment from
antiferromagnetically coupled Cr and Co atoms as measured with SQUID
magnetometry and soft X-ray magnetic circular dichroism. Electrical
measurements demonstrated a thermally-activated semiconductor-like resistivity
with an activation energy of 87 meV. These results confirm spin gapless
semiconducting behavior, which makes these thin films well positioned for
future devices.",1610.05808v1
2016-10-29,Tailoring magnetic insulator proximity effects in graphene: First-principles calculations,"We report a systematic first-principles investigation of the influence of
different magnetic insulators on the magnetic proximity effect induced in
graphene. Four different magnetic insulators are considered: two ferromagnetic
europium chalcogenides namely EuO and EuS and two ferrimagnetic insulators
yttrium iron garnet (YIG) and cobalt ferrite (CFO). The obtained
exchange-splitting varies from tens to hundreds of meV. We also find an
electron doping induced by YIG and europium chalcogenides substrates, that
shift the Fermi level up to 0.78 eV and 1.3 eV respectively, whereas hole
doping up to 0.5 eV is generated by CFO. Furthermore, we study the variation of
the extracted exchange and tight binding parameters as a function of the EuO
and EuS thicknesses. We show that those parameters are robust to thickness
variation such that a single monolayer of magnetic insulator can induce a large
magnetic proximity effect on graphene. Those findings pave the way towards
possible engineering of graphene spin-gating by proximity effect especially in
view of recent experiments advancement.",1610.09554v1
2017-02-03,Quantitative investigation of the inverse Rashba-Edelstein effect in Bi/Ag and Ag/Bi on YIG,"The inverse Rashba-Edelstein effect (IREE) is a spin conversion mechanism
that recently attracts attention in spintronics and condensed matter physics.
In this letter, we report an investigation of the IREE in Bi/Ag by using
ferrimagnetic insulator yttrium iron garnet (YIG). We prepared two types of
samples with opposite directions of the Rashba field by changing a stacking
order of Bi and Ag. An electric current generated by the IREE was observed from
both stacks, and an efficiency of spin conversion -characterized by the IREE
length- was estimated by taking into account a number of contributions left out
in previous studies. This study provides a further insight into the IREE spin
conversion mechanism: important step towards achieving efficient spin-charge
conversion devices.",1702.00890v1
2017-02-13,Magnetic properties and spin structure of MnO single crystal and powder,"Zero field cooled (ZFC)/Field Cooled (FC) magnetization curves of a bulk MnO
single crystal show a peculiar peak at low temperatures (~40K) similar to the
low temperature peak observed in MnO nanoparticles. In order to investigate the
origin of this peak, the spin structure of a MnO single crystal has been
studied and compared with a single phase powder sample using magnetometry and
polarized neutron scattering. Both magnetometry and polarized neutron
diffraction results confirm the antiferromagnetic (AF) phase transition at the
N\'eel temperature T_N of 118K, in both powder and single crystal form.
However, the low temperature peak in the ZFC/FC magnetization curves is not
observed in single phase MnO powder. To better understand the observed
behavior, ac susceptibility measurements have been employed. We conclude that
the clear peak in the magnetic signal from the single crystal originates from a
small amount of ferrimagnetic (FiM) Mn2O3 or Mn3O4 impurities, which is grown
at the interfaces between MnO crystal twins.",1702.03879v1
2017-02-13,Kagome-like chains with anisotropic ferromagnetic and antiferromagnetic interactions,"We consider a spin-$\frac{1}{2}$ kagome-like chain with competing ferro- and
antiferromagnetic anisotropic exchange interactions. The ground state phase
diagram of this model consists of the ferromagnetic and ferrimagnetic phases.
We study the ground state and the low-temperature properties on the phase
boundary between these phases. The ground state on this phase boundary is
macroscopically degenerate and consists of localized magnon states. We
calculate the ground state degeneracy and corresponding residual entropy. The
spontaneous magnetization has a jump on the phase boundary confirming the
first-order type of the phase transition. In the limit of a strong anisotropy
the spectrum of the low-energy excitations has multi-scale structure governing
the peculiar features of the specific heat behavior.",1702.03915v1
2017-02-20,Effect of annealing on the magnetic properties of zinc ferrite thin films,"We report on the magnetic properties of zinc ferrite thin film deposited on
SrTiO$_3$ single crystal using pulsed laser deposition. X-ray diffraction
result indicates the highly oriented single phase growth of the film along with
the presence of the strain. In comparison to the bulk antiferromagnetic order,
the as-deposited film has been found to exhibit ferrimagnetic ordering with a
coercive field of 1140~Oe at 5~K. A broad maximum, at $\approx$105~K, observed
in zero-field cooled magnetization curve indicates the wide grain size
distribution for the as-deposited film. Reduction in magnetization and blocking
temperature has been observed after annealing in both argon as well as oxygen
atmospheres, where the variation was found to be dependent on the annealing
temperature.",1702.06033v1
2017-02-21,Topological staggered field-electric effect with bipartite magnets,"We study the interface physics of bipartite magnetic materials deposited on a
topological insulator. This comprises antiferromagnets as well as ferrimagnets
and ferromagnets with multiple magnetic moments per unit cell. If an energy gap
is induced in the Dirac states on the topological surface, a topological
magnetoelectric effect has been predicted. Here, we show that this effect can
act in opposite directions on the two components of the magnet in certain
parameter regions. Consequently, an electric field will mainly generate a
staggered field rather than a net magnetization in the plane. This is relevant
for the current attempts to detect the magnetoelectric effect experimentally,
as well as for possible applications. We take a field-theoretic approach that
includes the quantum fluctuations of both the Dirac fermions on the topological
surface as well as the fermions in the surface layer of the magnet in an
analytically solvable model. The effective Lagrangian and the Landau-Lifshitz
equation describing the interfacial magnetization dynamics are derived.",1702.06483v2
2017-02-26,Magnon-photon coupling in antiferromagnets,"Magnon-photon coupling in antiferromagnets has many attractive features that
do not exist in ferro- or ferrimagnets. We show quantum-mechanically that, in
the absence of an external field, one of the two degenerated spin wave bands
couples with photons while the other does not. The photon mode anticrosses with
the coupled spin waves when their frequencies are close to each other. Similar
to its ferromagnetic counterpart, the magnon-photon coupling strength is
proportional to the square root of number of spins $\sqrt{N}$ in
antiferromagnets. An external field removes the spin wave degeneracy and both
spin wave bands couple to the photons, resulting in two anticrossings between
the magnons and photons. Two transmission peaks were observed near the
anticrossing frequency. The maximum damping that allows clear discrimination of
the two transmission peaks is proportional to $\sqrt{N}$ and it's well below
the damping of antiferromagnetic insulators. Therefore the strong magnon-photon
coupling can be realized in antiferromagnets and the coherent information
transfer between the photons and magnons is possible.",1702.07977v1
2017-03-01,Thickness Dependence of Spin-Orbit Torques in Ferrimagnetic GdFeCo Alloys,"So far, studies of spin-orbit torques (SOT) in ferromagnets with
perpendicular magnetic anisotropy (PMA) have been restricted to ultra thin
samples, while a systematic study of its thickness dependence is still lacking
in literature. In this article we discuss the thickness dependence of SOT in
GdFeCo samples with bulk PMA. We show that the effective SOT fields are
decreasing inversely as a function of thickness while the spin-Hall angle stays
constant, as expected from angular momentum conservation. Further we show that
even 30nm thick GdFeCo samples can be switched with SOT. This has important
technological implications as the switching efficiency does not depend on the
thickness. Finally, we investigate the composition dependence of SOT in 30nm
thick GdFeCo samples and find that the spin torque effective field diverges at
the magnetization compensation point.",1703.00146v1
2017-03-08,Spin dynamics of antiferromagnets in the presence of a homogeneous magnetization,"We use general hydrodynamic equations to determine the long-wavelength spin
excitations in isotropic antiferromagnets in the presence of a homogeneous
magnetization. The latter may be induced, such as in antiferromagnets in an
external magnetic field, or spontaneous, such as in ferrimagnetic or canted
phases that are characterized by the coexistence of antiferromagnetic and
ferromagnetic order. Depending on the physical situation, we find propagating
spin waves that are gapped in some cases and gapless in others, diffusive
modes, or relaxational modes. The excitation spectra turn out to be
qualitatively different depending on whether or not the homogeneous
magnetization is a conserved quantity. The results lay the foundation for a
description of a variety of quantum phase transitions, including the transition
from a ferromagnetic metal to an antiferromagnetic one, and the spin-flop
transitions that are observed in some antiferromagnets. They also are crucial
for incorporating weak-localization and Altshuler-Aronov effects into the
descriptions of quantum phases in both clean and disordered magnetic metals.",1703.03009v1
2017-03-11,Generalized Boundary Conditions for Spin Transfer,"We develop a comprehensive description of static and dynamic spin-transfer
torque at interfaces between a normal metal and a magnetic material. Specific
examples of the latter include ferromagnets, collinear and noncollinear
antiferromagnets, general ferrimagnets, and spin glasses. We study the limit of
the exchange-dominated interactions, so that the full system is isotropic in
spin space, apart from a possible symmetry-breaking order. A general such
interface yields three coefficients (corresponding to three independent
generators of rotations) generalizing the well-established notion of the
spin-mixing conductance, which pertains to the collinear case. We develop a
nonequilibrium thermodynamic description of the emerging interfacial spin
transfer and its effect on the collective spin dynamics, while circumventing
the usual discussion of spin currents and net spin dynamics. Instead, our focus
is on the dissipation and work effectuated by the interface. Microscopic
scattering-matrix based expressions are derived for the generalized
spin-transfer coefficients.",1703.04020v2
2017-03-31,(LaTiO$_3$)$_n$/(LaVO$_3$)$_n$ as a model system for unconventional charge transfer and polar metallicity,"At interfaces between oxide materials, lattice and electronic reconstructions
always play important roles in exotic phenomena. In this study, the density
functional theory and maximally localized Wannier functions are employed to
investigate the (LaTiO$_3$)$_n$/(LaVO$_3$)$_n$ magnetic superlattices. The
electron transfer from Ti$^{3+}$ to V$^{3+}$ is predicted, which violates the
intuitive band alignment based on the electronic structures of LaTiO$_3$ and
LaVO$_3$. Such unconventional charge transfer quenches the magnetism of
LaTiO$_3$ layer mostly and leads to metal-insulator transition in the $n=1$
superlattice when the stacking orientation is altered. In addition, the
compatibility among the polar structure, ferrimagnetism, and metallicity is
predicted in the $n=2$ superlattice.",1703.10748v1
2017-03-31,Spin Seebeck effect in Y-type hexagonal ferrite thin films,"Spin Seebeck effect (SSE) has been investigated in thin films of two
Y-hexagonal ferrites Ba$_2$Zn$_{2}$Fe$_{12}$O$_{22}$ (Zn2Y) and
Ba$_2$Co$_{2}$Fe$_{12}$O$_{22}$ (Co2Y) deposited by a spin-coating method on
SrTiO$_3$(111) substrate. The selected hexagonal ferrites are both
ferrimagnetic with similar magnetic moments at room temperature and both
exhibit easy magnetization plane normal to $c$-axis. Despite that, SSE signal
was only observed for Zn2Y, whereas no significant SSE signal was detected for
Co2Y. We tentatively explain this different behavior by a presence of two
different magnetic ions in Co2Y, whose random distribution over octahedral
sites interferes the long range ordering and enhances the Gilbert damping
constant. The temperature dependence of SSE for Zn2Y was measured and analyzed
with regard to the heat flux and temperature gradient relevant to the SSE
signal.",1703.10903v1
2017-08-02,Realistic finite temperature simulations of magnetic systems using quantum statistics,"We have performed realistic atomistic simulations at finite temperatures
using Monte Carlo and atomistic spin dynamics simulations incorporating quantum
(Bose-Einstein) statistics. The description is much improved at low
temperatures compared to classical (Boltzmann) statistics normally used in
these kind of simulations, while at higher temperatures the classical
statistics are recovered. This corrected low-temperature description is
reflected in both magnetization and the magnetic specific heat, the latter
allowing for improved modeling of the magnetic contribution to free energies. A
central property in the method is the magnon density of states at finite
temperatures and we have compared several different implementations for
obtaining it. The method has no restrictions regarding chemical and magnetic
order of the considered materials. This is demonstrated by applying the method
to elemental ferromagnetic systems, including Fe and Ni, as well as Fe-Co
random alloys and the ferrimagnetic system GdFe$_3$ .",1708.00709v1
2017-08-08,Observation of Giant Exchange Bias and Topological Hall Effect in Manganese Nitride Films,"Magnetic and magneto-transport properties of manganese nitride films grown by
molecular beam epitaxy have been investigated. Due to the mixed ferrimagnetic
(FI) phase (${\epsilon}$-phase with TFI ~ 738 K) and the antiferromagnetic
phase (${\zeta}$-phase with TN ~ 273 K), we observe magnetization hysteresis
loops with non-zero exchange bias below TN, reaching ~ 0.22 T at 5 K. This
indicates that noncollinear spins exist at the interfaces between two phases,
creating a competition between interfacial Dzyaloshinskii-Moriya (DM) and
exchange interactions. Strikingly, in addition to the normal Hall effect by
Lorentz force and anomalous Hall effect by magnetization, we observe new
contribution namely topological Hall effect below 75 K. This verifies the
existence of topological spin texture, which is the consequence of competing
interactions controlled by both applied field and temperature. Our work
demonstrates that spintronic devices may be fabricated exploiting rich magnetic
properties of different phases.",1708.02540v1
2017-08-29,"Structural, magnetic, and electronic properties of GdTiO3 Mott insulator thin films grown by pulsed laser deposition","We report on the optimization process to synthesize epitaxial thin films of
GdTiO3 on SrLaGaO4 substrates by pulsed laser deposition. Optimized films are
free of impurity phases and are fully strained. They possess a magnetic Curie
temperature TC = 31.8 K with a saturation magnetization of 4.2 muB per formula
unit at 10 K. Transport measurements reveal an insulating response, as
expected. Optical spectroscopy indicates a band gap of 0.7 eV, comparable to
the bulk value. Our work adds ferrimagnetic orthotitanates to the palette of
perovskite materials for the design of emergent strongly correlated states at
oxide interfaces using a versatile growth technique such as pulsed laser
deposition.",1708.08785v1
2017-08-29,Element-resolved ultrafast demagnetization rates in ferrimagnetic CoDy,"Femtosecond laser induced ultrafast magnetization dynamics have been studied
in multisublattice CoxDy1-x alloys. By performing element and time-resolved
X-ray spectroscopy, we distinguish the ultrafast quenching of Co3d and Dy4f
magnetic order when the initial temperatures are below (T=150K) or above
(T=270K) the temperature of magnetic compensation (Tcomp). In accordance with
former element-resolved investigations and theoretical calculations, we observe
different dynamics for Co3d and Dy4f spins. In addition we observe that, for a
given laser fluence, the demagnetization amplitudes and demagnetization times
are not affected by the existence of a temperature of magnetic compensation.
However, our experiment reveals a twofold increase of the ultrafast
demagnetization rates for the Dy sublattice at low temperature. In parallel, we
measure a constant demagnetization rate of the Co3d sublattice above and below
Tcomp. This intriguing difference between the Dy4f and Co3d sublattices calls
for further theoretical and experimental investigations.",1708.08918v2
2018-11-12,Current direction anisotropy of the spin Hall magnetoresistance in nickel ferrite thin films with bulk-like magnetic properties,"We utilize spin Hall magnetoresistance (SMR) measurements to experimentally
investigate the pure spin current transport and magnetic properties of nickel
ferrite (NiFe2O4,NFO)/normal metal (NM) thin film heterostructures. We use
(001)-oriented NFO thin films grown on lattice-matched magnesium gallate
substrates by pulsed laser deposition, which significantly improves the
magnetic and structural properties of the ferrimagnetic insulator. The NM in
our experiments is either Pt or Ta. A comparison of the obtained SMR magnitude
for charge currents applied in the [100]- and [110]-direction of NFO yields a
change of 50% for Pt at room temperature. We also investigated the temperature
dependence of this current direction anisotropy and find that it is
qualitatively different for the conductivity and the SMR magnitude. From our
results we conclude that the observed current direction anisotropy may
originate from an anisotropy of the spin mixing conductance or of the spin Hall
effect in these Pt and Ta layers, and/or additional spin-galvanic contributions
from the NFO/NM interface.",1811.04696v1
2018-11-14,Anomalous Hall-like transverse magnetoresistance in Au thin films on Y$_3$Fe$_5$O$_{12}$,"Anomalous Hall-like signals in platinum in contact with magnetic insulators
are common observations that could be explained by either proximity
magnetization or spin Hall magnetoresistance. In this work, longitudinal and
transverse magnetoresistances are measured in a pure gold thin film on the
ferrimagnetic insulator Y$_3$Fe$_5$O$_{12}$ (Yttrium Iron Garnet, YIG). We show
that both the longitudinal and transverse magnetoresistances have
quantitatively consistent scaling in YIG/Au and in a YIG/Pt reference system
when applying the Spin Hall magnetoresistance framework. No contribution of an
anomalous Hall effect due to the magnetic proximity effect is evident.",1811.05848v1
2018-11-30,Magnetic and mechanical effects of Mn substitutions in AlFe2B2,"The mechanical and magnetic properties of the newly discovered MAB-phase
class of materials based upon AlFe2B2 were investigated. The samples were
synthesised from stoichiometric amounts of all constituent elements. X-ray
diffraction shows that the main phase is orthorhombic with an elongated b-axis,
similar to AlFe2B2. The low hardness and visual inspection of the samples after
deformation indicate that these compounds are deformed via a delamination
process. When substituting iron in AlFe2B2 with manganese, the magnetism in the
system goes from being ferro- to antiferromagnetic via a disordered
ferrimagnetic phase exhibited by AlFeMnB2. Density functional theory
calculations indicate a weakening of the magnetic interactions among the
transitions metal ions as iron is substituted by manganese in AlFe2B2. The
Mn-Mn exchange interactions in AlMn2 B2 are found to be very small.",1811.12720v1
2019-05-09,A Novel ground state in a new dimer iridate Ba13Ir6O30 with Ir6+(5d3) Ions,"We have synthesized and studied a new iridate, Ba13Ir6O30, with unusual Ir
oxidation states: 2/3 Ir6+(5d3) ions and 1/3 Ir5+(5d4) ions. Its crystal
structure features dimers of face-sharing IrO6 octahedra, and IrO6 monomers,
that are linked via long, zigzag Ir-O-Ba-O-Ir pathways. Nevertheless,
Ba13Ir6O30 exhibits two transitions at TN1 = 4.7 K and TN2 = 1.6 K. This
magnetic order is accompanied by a huge Sommerfeld coefficient 200 mJ/mole K
below TN2, signaling a coexisting frustrated/disordered state persisting down
to at least 0.05 K. This iridate hosts unusually large Jeff=3/2 degrees of
freedom, which is enabled by strong spin-orbit interactions (SOI) in the
monomers with Ir6+ ions and a joint effect of molecular orbitals and SOI in the
dimers occupied by Ir5+ and Ir6+ ions. Features displayed by the magnetization
and heat capacity suggest that the combination of covalency, SOI and large
effective spins leads to highly frustrated ferrimagnetic ordering, possibly
into a skyrmion crystal, a novelty of this new high-spin iridate.",1905.03891v1
2019-05-18,"The New Nitrides: Layered, Ferroelectric, Magnetic, Metallic and Superconducting Nitrides to Boost the GaN Photonics and Electronics Eco-System","The nitride semiconductor materials GaN, AlN, and InN, and their alloys and
heterostructures have been investigated extensively in the last 3 decades,
leading to several technologically successful photonic and electronic devices.
Just over the past few years, a number of new nitride materials have emerged
with exciting photonic, electronic, and magnetic properties. Some examples are
2D and layered hBN and the III-V diamond analog cBN, the transition metal
nitrides ScN, YN, and their alloys (e.g. ferroelectric ScAlN), piezomagnetic
GaMnN, ferrimagnetic Mn4N, and epitaxial superconductor/semiconductor NbN/GaN
heterojunctions. This article reviews the fascinating and emerging physics and
science of these new nitride materials. It also discusses their potential
applications in future generations of devices that take advantage of the
photonic and electronic devices eco-system based on transistors, light-emitting
diodes, and lasers that have already been created by the nitride
semiconductors.",1905.07627v1
2019-05-23,"Thermodynamic and Thermoelectric Properties of CoFeYGe (Y= Ti, Cr) Quaternary Heusler Alloys: First Principle Calculations","Utilizing a material in thermoelectric applications requires a mechanical,
thermal, and lattice stability as well a high figure of merit (ZT). In this
work, we present the structural, electronic, magnetic, mechanical,
thermodynamic, dynamic, and thermoelectric properties of CoFeYGe (Y = Ti, Cr)
quaternary Heusler compounds using the density functional theory (DFT). The
calculated mechanical properties and phonon dispersions reveal that the
structures of these compounds are stable. Both CoFeCrGe and CoFeTiGe compounds
show a ferromagnetic and ferrimagnetic half-metallic behavior with band gaps of
0.41 and 0.38 eV, respectively. The lattice thermal conductivity (\k{appa}L)
exhibits low values that reach 3.01 W/(m.K) (3.47 W/(m.K)) for CoFeCrGe
(CoFeTiGe) at 1100 K. The optical phonon modes have a large contribution of
60.2% (70.9 %) to \k{appa}L value for CoFeCrGe (CoFeTiGe). High ZT values of
0.71 and 0.65 were obtained for CoFeCrGe and CoFeTiGe, respectively. Based on
our calculations, CoFeCrGe and CoFeTiGe combine both good spintronic and
thermoelectric behaviors that may be used in spin injection applications.",1905.09854v1
2020-07-07,Unconventional superconductivity in a strongly correlated band-insulator without doping,"We present a novel route for attaining unconventional superconductivity (SC)
in a strongly correlated system without doping. In a simple model of a
correlated band insulator (BI) at half-filling we demonstrate, based on a
generalization of the projected wavefunctions method, that SC emerges when e-e
interactions and the bare band-gap are both much larger than the kinetic
energy, provided the system has sufficient frustration against the magnetic
order. As the interactions are tuned, SC appears sandwiched between the
correlated BI followed by a paramagnetic metal on one side, and a ferrimagnetic
metal, antiferromagnetic (AF) half-metal, and AF Mott insulator phases on the
other side.",2007.03739v2
2020-07-13,Intra-chain collinear magnetism and inter-chain magnetic phases in Cr3As3-K-based materials,"We perform a comparative study of the KCr3As3 and the K2Cr3As3 quasi 1D
compounds, and show that the strong interplay between the lattice and the spin
degrees of freedom promotes a new collinear ferrimagnetic ground state within
the chains in presence of intrachain antiferromagnetic couplings. We propose
that the interchain antiferromagnetic coupling in KCr3As3 plays a crucial role
for the experimentally observed spin-glass phase with low critical temperature.
In the same region of the parameter space, we predict K2Cr3As3 to be
non-magnetic but on the verge of the magnetism, sustaining interchain
ferromagnetic spin fluctuations while the intrachain spin fluctuations are
antiferromagnetic.",2007.06337v4
2013-08-06,Two magnon bound state causes ultrafast thermally induced magnetisation switching,"There has been much interest recently in the discovery of thermally induced
magnetisation switching, where a ferrimagnetic system can be switched
deterministically without and applied magnetic field. Experimental results
suggest that the reversal occurs due to intrinsic material properties, but so
far the microscopic mechanism responsible for reversal has not been identified.
Using computational and analytic methods we show that the switching is caused
by the excitation of two magnon bound states, the properties of which are
dependent on material factors. This discovery allows us to accurately predict
the switching behaviour and the identification of this mechanism will allow new
classes of materials to be identified or designed to use this switching in
memory devices in the THz regime.",1308.1314v1
2013-08-13,Interface states in CoFe2O4 spin-filter tunnel junctions,"Spin-filter tunneling is a promising way to generate highly spin-polarized
current, a key component for spintronics applications. In this work we explore
the tunneling conductance across the spin-filter material CoFe2O4 interfaced
with Au electrodes, a geometry which provides nearly perfect lattice matching
at the CoFe2O4/Au(001) interface. Using density functional theory calculations
we demonstrate that interface states play a decisive role in controlling the
transport spin polarization in this tunnel junction. For a realistic CoFe2O4
barrier thickness, we predict a tunneling spin polarization of about -60%. We
show that this value is lower than what is expected based solely on
considerations of the spin-polarized band structure of CoFe2O4, and therefore
that these interface states can play a detrimental role. We argue this is a
rather general feature of ferrimagnetic ferrites and could make an important
impact on spin-filter tunneling applications.",1308.3461v1
2014-03-04,All-optical control of ferromagnetic thin films and nanostructures,"The interplay of light and magnetism has been a topic of interest since the
original observations of Faraday and Kerr where magnetic materials affect the
light polarization. While these effects have historically been exploited to use
light as a probe of magnetic materials there is increasing research on using
polarized light to alter or manipulate magnetism. For instance deterministic
magnetic switching without any applied magnetic fields using laser pulses of
the circular polarized light has been observed for specific ferrimagnetic
materials. Here we demonstrate, for the first time, optical control of
ferromagnetic materials ranging from magnetic thin films to multilayers and
even granular films being explored for ultra-high-density magnetic recording.
Our finding shows that optical control of magnetic materials is a much more
general phenomenon than previously assumed. These results challenge the current
theoretical understanding and will have a major impact on data memory and
storage industries via the integration of optical control of ferromagnetic
bits.",1403.0784v1
2017-01-10,Temperature dependence of the non-local spin Seebeck effect in YIG/Pt nanostructures,"We study the transport of thermally excited non-equilibrium magnons through
the ferrimagnetic insulator YIG using two electrically isolated Pt strips as
injector and detector. The diffusing magnons induce a non- local inverse spin
Hall voltage in the detector corresponding to the so-called non-local spin
Seebeck effect (SSE). We measure the non-local SSE as a function of temperature
and strip separation. In experiments at room temperature we observe a sign
change of the non-local SSE voltage at a characteristic strip separation d0, in
agreement with previous investigations. At lower temperatures however, we find
a strong temperature dependence of d0. This suggests that both the angular
momentum transfer across the YIG/Pt interface as well as the transport
mechanism of the magnons in YIG as a function of temperature must be taken into
account to describe the non-local spin Seebeck effect.",1701.02635v1
2017-04-20,Ferrimagnetism in the Spin-1/2 Heisenberg Antiferromagnet on a Distorted Triangular Lattice,"The ground state of the spin-$1/2$ Heisenberg antiferromagnet on a distorted
triangular lattice is studied using a numerical-diagonalization method. The
network of interactions is the $\sqrt{3}\times\sqrt{3}$ type; the interactions
are continuously controlled between the undistorted triangular lattice and the
dice lattice. We find new states between the nonmagnetic 120-degree-structured
state of the undistorted triangular case and the up-up-down state of the dice
case. The intermediate states show spontaneous magnetizations that are smaller
than one third of the saturated magntization corresponding to the up-up-down
state.",1704.06013v2
2017-04-25,Probing length-scale separation of thermal and spin currents by nanostructuring YIG,"We have fabricated bulk nanostructured ferrimagnetic materials with different
grain sizes by sintering ball-milled Y3Fe5O12 (YIG) nanoparticles and measured
the grain-size dependence of the thermal conductivity and spin Seebeck
thermopower. The nanostructuring reduces both thermal conductivity and
thermopower, but the reduction of the latter was found to be considerably
stronger despite the moderate difference in magnetization, which suggests that
the length scales of transport of magnons and phonons contributing to the spin
Seebeck effect are significantly larger than that of phonons carrying thermal
current. This is consistent with the measurements of high-magnetic-field
response of the spin Seebeck thermopower and low-temperature thermal
conductivity, where the quenching of magnons seen in single-crystalline YIG was
not observed in nanostructured YIG due to scattering of long-range low
frequency magnons.",1704.07568v1
2018-05-07,Single-shot multi-level all-optical magnetization switching mediated by spin-polarized hot electron transport,"All-optical ultrafast magnetization switching in magnetic material thin film
without the assistance of an applied external magnetic field is being explored
for future ultrafast and energy-efficient magnetic storage and memories. It has
been shown that femto-second light pulses induce magnetization reversal in a
large variety of magnetic materials. However, so far, only GdFeCo-based
ferrimagnetic thin films exhibit magnetization switching via a single optical
pulse. Here we demonstrate the single-pulse switching of Co/Pt multilayers
within a magnetic spin-valve structure ([Co/Pt] / Cu / GdFeCo) and further show
that the four possible magnetic configurations of the spin valve can be
accessed using a sequence of single femto-second light pulses. Our experimental
study reveals that the magnetization final state of the ferromagnetic [Co/Pt]
layer is determined by spin-polarized hot electrons generated by the light
pulse interactions with the GdFeCo layer. This work provides a new approach to
deterministically switch ferromagnetic layers and a pathway to engineering
materials for opto-magnetic multi-bit recording.",1805.02432v1
2018-05-09,Nature of the Magnetic Interactions in Sr$_3$NiIrO$_6$,"Iridates abound with interesting magnetic behaviours because of their strong
spin-orbit coupling. Sr$_3$NiIrO$_6$ brings together the spin-orbital
entanglement of the Ir$^{4+}$ ion with a 3$d$ Ni cation and a one-dimensional
crystal structure. It has a ferrimagnetic ground state with a 55 T coercive
field. We perform a theoretical study of the magnetic interactions in this
compound, and elucidate the role of anisotropic symmetric exchange as the
source of its strong magnetic anisotropy. Our first-principles calculations
reproduce the magnon spectra of this compound and predict a signature in the
cross sections that can differentiate the anisotropic exchange from single-ion
anisotopy.",1805.03733v2
2018-05-26,Observation of gyromagnetic reversal,"We report direct observation of gyromagnetic reversal, which is the sign
change of gyromagnetic ratio in a ferrimagnet Ho$_3$Fe$_5$O$_{12}$, by using
the Barnett effect measurement technique at low temperatures. The Barnett
effect is a phenomenon in which magnetization is induced by mechanical rotation
through the coupling between rotation and total angular momentum $J$ of
electrons. The magnetization of Ho$_3$Fe$_5$O$_{12}$ induced by mechanical
rotation disappears at 135~K and 240~K. The temperatures correspond to the
magnetization compensation temperature $T_{\rm M}$ and the angular momentum
compensation temperature $T_{\rm A}$, respectively. Between $T_{\rm M}$ and
$T_{\rm A}$, the magnetization flips over to be parallel against the angular
momentum due to the sign change of gyromagnetic ratio. This study provides an
unprecedented technique to explore the gyromagnetic properties.",1805.10426v3
2009-12-05,Electrical and magnetic transport properties of Fe3O4 thin films on GaAs (100) substrate,"Thin films of magnetite (Fe3O4) are grown on single crystal GaAs (100)
substrate by pulsed laser deposition. X ray diffraction (XRD) result shows the
(111) preferred orientation of the Fe3O4 film and x-ray photoelectron
spectroscopy confirm the presence of single phase Fe3O4 in the film. The
electrical transport property of the film shows the characteristic Verwey
transition at 122 K and below 110 K, the transport follows variable range
hopping type conduction mechanism. The film shows room temperature
magnetization hysteresis loop suggesting the ferrimagnetic behavior of the film
with saturation magnetization value close to 470 emu/cc.",0912.0979v1
2011-11-03,Competing Ferri- and Antiferromagnetic Phases in Geometrically Frustrated LuFe2O4,"We present a detailed study of magnetism in LuFe2O4, combining magnetization
measurements with neutron and soft x-ray diffraction. The magnetic phase
diagram in the vicinity of T_N involves a metamagnetic transition separating an
antiferro- and a ferrimagnetic phase. For both phases the spin structure is
refined by neutron diffraction. Observed diffuse magnetic scattering far above
T_N is explained in terms of near degeneracy of the magnetic phases.",1111.0746v1
2011-11-18,Exchange Bias Induced by the Fe3O4 Verwey transition,"We present a study of the exchange bias in different configurations of V2O3
thin films with ferromagnetic layers. The exchange bias is accompanied by a
large vertical shift in the magnetization. These effects are only observed when
V2O3 is grown on top of Ni80Fe20 permalloy. The magnitude of the vertical shift
is as large as 60% of the total magnetization which has never been reported in
any system. X-Ray diffraction studies show that the growth conditions promote
the formation of a ferrimagnetic Fe3O4 interlayer. The change in the easy
magnetization axis of Fe3O4 across the Verwey transition at 120 K is correlated
with the appearance of exchange bias and vertical shift in magnetization. Both
phenomena disappear above 120 K, indicating for the first time a direct
relationship between the magnetic signature of the Verwey transition and
exchange bias.",1111.4255v2
2012-04-12,Magnetic order and ice rules in the multiferroic spinel FeV2O4,"We present a neutron diffraction study of FeV2O4, which is rare in exhibiting
spin and orbital degrees of freedom on both cation sublattices of the spinel
structure. Our data confirm the existence of three structural phase transitions
previously identified with x-ray powder diffraction, and reveal that the lower
two transitions are associated with sequential collinear and canted
ferrimagnetic transitions involving both cation sites. Through consideration of
local crystal and spin symmetry, we further conclude that Fe2+ cations are
ferro-orbitally ordered below 135K and V3+ orbitals order at 60K in accordance
with predictions for vanadium spinels with large trigonal distortions and
strong spin-orbit coupling. Intriguingly, the direction of ordered vanadium
spins at low temperatures obey `ice rules' more commonly associated with the
frustrated rare-earth pyrochlore systems.",1204.2812v3
2012-04-14,"Evaluation of Half-metallic Antiferromagnetism in ${\cal A}_2$CrFeO$_6$ ({$\cal A$}=La, Sr","The nearly well-ordered double perovskite La$_2$CrFeO$_6$ has been
synthesized recently. Contrary to previous theoretical predictions, but in
agreement with experimental observations, our first principle calculations
indicate an insulating ferrimagnet La$_2$CrFeO$_6$ with antialigned S=3/2
Cr$^{3+}$ and S=5/2 Fe$^{3+}$ ions,using the local spin density approximation
(LSDA), a correlated band theory LDA+U, and a semilocal functional modified
Becke-Johnson method. Additionally, we investigated the double perovskite
Sr$_2$CrFeO$_6$, which is as yet unsynthesized. In LSDA calculations, this
system shows formally tetravalent Cr and Fe ions both having antialigned $S$=1
moments, but is a simple metal. Once applying on-site Coulomb repulsion U on
both Cr and Fe ions, this system becomes half-metallic and the moment of Fe is
substantially reduced, resulting in zero net moment. These results are
consistent with our fixed spin moment studies. Our results suggest a precisely
compensated half-metallic Sr$_2$CrFeO$_6$.",1204.3150v2
2012-04-16,Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3,"We report a long-wavelength helimagnetic superstructure in bulk samples of
the ferrimagnetic insulator Cu2OSeO3. The magnetic phase diagram associated
with the helimagnetic modulation inferred from small angle neutron scattering
and magnetisation measurements includes a skyrmion lattice phase and is
strongly reminiscent of MnSi, FeGe and Fe1-xCoxSi, i.e., binary isostructural
siblings of Cu2OSeO3 that order helimagnetically. The temperature dependence of
the specific heat of Cu2OSeO3 is characteristic of nearly critical spin
fluctuations at the helimagnetic transition. This provides putative evidence
for effective spin currents as the origin of enhancements of the
magneto-dielectric response instead of atomic displacements considered so far.",1204.3597v1
2013-08-30,Magnetocapacitance as a sensitive probe of magnetostructural changes in NiCr$_2$O$_4$,"The spinel NiCr$_2$O$_4$ is characterized using dielectric and high magnetic
field measurements. The trends in the magnetodielectric response fall into
three clear temperature regimes corresponding to known magnetic and structural
transitions. Above 65\,K, weak magnetic field dependence of the dielectric
constant is observed with no hysteresis. When 30\,K\,$\leq\,T\,\leq$\,65\,K, a
strong dependence of the dielectric constant on the magnetic field is observed
and hysteresis develops resulting in so called butterfly loops. Below 30\,K,
magnetodielectric hysteresis is enhanced. Magnetodielectric hysteresis mirrors
magnetic hysteresis suggesting that spin-spin interactions are the mechanism
for the magnetoelectric effect in NiCr$_2$O$_4$. At high fields however, the
magnetization continues to increase while the dielectric constant saturates.
Magnetodielectric measurements of NiCr$_2$O$_4$ suggest an additional,
previously unobserved transition at 20\,K. Subtle changes in magnetism and
structure suggest that this 20\,K anomaly corresponds to the completion of
ferrimagnetic ordering and the spin driven structural distortion. We
demonstrate that magnetocapacitance is a sensitive probe of magnetostructural
distortion.",1309.0016v1
2013-09-06,"Magnetism and local structure in low-dimensional, Mott insulating GdTiO3","Cation displacements, oxygen octahedral tilts, and magnetism of epitaxial,
ferrimagnetic, insulating GdTiO3 films sandwiched between cubic SrTiO3 layers
are studied using scanning transmission electron microscopy and magnetization
measurements. With decreasing GdTiO3 film thickness, structural (GdFeO3-type)
distortions are reduced, concomitant with a reduction in the Curie temperature.
Ferromagnetism persists to smaller deviations from the cubic perovskite
structure than is the case for the bulk rare earth titanates. The results
indicate that the FM ground state is controlled by the narrow bandwidth,
exchange and orbital ordering, and only to second order depends on amount of
the GdFeO3-type distortion.",1309.1531v1
2013-09-13,Thermodynamic properties of a diluted triangular Ising antiferromagnet in a field,"Within the framework of the effective-field theory with correlations we
investigate effects of an external magnetic field and random site dilution on
basic thermodynamic quantities, such as the magnetization and the magnetic
susceptibility, of the geometrically frustrated triangular lattice Ising
antiferromagnet. Behavior of these quantities is presented in the
temperaturefield parameter space for selected mild degrees of dilution. It is
found that, besides the anomalies associated with phase transitions from the
ferrimagnetic to the paramagnetic state, in some regions of the parameter space
these functions display some more anomalies and peculiarities, as a result of
joint effects of the geometrical frustration, magnetic dilution, thermal
fluctuations and the applied magnetic field.",1309.3592v3
2013-09-25,Ab-initio calculation of the effective on-site Coulomb interaction parameters for half-metallic magnets,"Correlation effects play an important role in the electronic structure of
half-metallic (HM) magnets. In particular, they give rise to non-quasiparticle
states above (or below) the Fermi energy at finite temperatures that reduce the
spin polarization and, as a consequence, the efficiency of spintronics devices.
Employing the constrained random-phase approximation (cRPA) within the
full-potential linearized augmented-plane-wave (FLAPW) method using maximally
localized Wannier functions, we calculate the strength of the effective on-site
Coulomb interaction (Hubbard $U$ and Hund exchange $J$) between localized
electrons in different classes of HM magnets considering: (i)
\emph{sp}-electron ferromagnets in rock-salt structure, (ii) zincblende
3\emph{d} binary ferromagnets, as well as (iii) ferromagnetic and ferrimagnetic
semi- and full-Heusler compounds.",1309.6657v1
2014-05-02,Spin-Polarized-Current State of Electrons in Bilayer Graphene,"We propose a model of spin-polarized-current state for electrons in bilayer
graphene. The model resolves the puzzles as revealed by experiments that (a)
the energy gap $E_{\rm gap}$ of the insulating ground state at the charge
neutrality point (CNP) can be closed by a perpendicular electric field of
either polarity, (b) $E_{\rm gap}$ increases significantly with increasing the
magnetic field $B$, (c) the particle-hole spectrum is asymmetric in the
presence of $B$, (d) there is a peak structure in the electric conductivity at
small $B$ at the CNP, and (e) there are quantum Hall states stemming from
lifting of degeneracy in the lowest Landau level. The model predicts that the
ground state of the system close to the CNP is a ferrimagnet at finite $B$ and
the Hall current is spin polarized.",1405.0335v1
2014-05-09,Magnetization dynamics and damping due to electron-phonon scattering in a ferrimagnetic exchange model,"We present a microscopic calculation of magnetization damping for a magnetic
""toy model."" The magnetic system consists of itinerant carriers coupled
antiferromagnetically to a dispersionless band of localized spins, and the
magnetization damping is due to coupling of the itinerant carriers to a phonon
bath in the presence of spin-orbit coupling. Using a mean-field approximation
for the kinetic exchange model and assuming the spin-orbit coupling to be of
the Rashba form, we derive Boltzmann scattering integrals for the distributions
and spin coherences in the case of an antiferromagnetic exchange splitting,
including a careful analysis of the connection between lifetime broadening and
the magnetic gap. For the Elliott-Yafet type itinerant spin dynamics we extract
dephasing and magnetization times T_1 and T_2 from initial conditions
corresponding to a tilt of the magnetization vector, and draw a comparison to
phenomenological equations such as the Landau-Lifshitz or the Gilbert damping.
We also analyze magnetization precession and damping for this system including
an anisotropy field and find a carrier mediated dephasing of the localized spin
via the mean-field coupling.",1405.2347v1
2014-05-19,Multiferroic Iron Oxide Thin Films at Room-Temperature,"In spite of being highly relevant for the development of a new generation of
information storage devices, not many single-phase materials displaying
magnetic and ferroelectric orders above room temperature are known. Moreover,
these uncommon materials typically display insignificant values of the remanent
moment in one of the ferroic orders or are complex multicomponent oxides which
will be very challenging to integrate in devices. Here we report on the
strategy to stabilize the metastable epsilon-Fe2O3 in thin film form, and we
show that besides its already known ferrimagnetic nature, the films are also
ferroelectric at 300 K with a remanent polarization of 1 microC/cm2. The film
polarization shows long retention times and can be switched under small applied
voltages. These characteristics make of epsilon-Fe2O3 the first single-ion
transition-metal oxide which is ferro(ferri)magnetic and ferroelectric at room
temperature. The simple composition of this new multiferroic oxide and the
discovery of a robust path for its thin film growth may boost the exploitation
of epsilon-Fe2O3 in novel devices.",1405.4909v1
2014-05-27,"Non-d$^0$ Electric Dipole in FeO$_5$ bipyramid: a New Resource for Quantum Paraelectrics, Ferroelectrics and Multiferroics","Electric polarization in conventional ferroelectric oxides usually involves
nonmagnetic transition-metal ions with an empty d shell (the d$^0$ rule). Here
we unravel a new mechanism for local electric dipoles based on magnetic
Fe$^{3+}$ (3d$^5$) ion violating the d$^0$ rule. The competition between the
long-range Coulomb interaction and short-range Pauli repulsion in a FeO$_5$
bipyramid with proper lattice parameters would favor an off-center displacement
of Fe$^{3+}$ that induces a local electric dipole. The manipulation of this
kind of non-d$^0$ electric dipoles opens up a new route for generating
unconventional dielectrics, ferroelectrics, and multiferroics. As a prototype
example, we show that the non-d$^0$ electric dipoles in ferrimagnetic
hexaferrites (Ba,Sr)Fe$_{12}$O$_{19}$ lead to a new family of magnetic quantum
paraelectrics.",1405.6806v1
2014-06-05,Magnetic properties of epitaxial Fe$_3$O$_4$ films with various crystal orientations and TMR effect in room temperature,"Fe$_3$O$_4$ is a ferrimagnetic spinel ferrite that exhibits electric
conductivity at room temperature (RT). Although the material has been predicted
to be a half metal according to ab-initio calculations, magnetic tunnel
junctions (MTJs) with Fe$_3$O$_4$ electrodes have demonstrated a small tunnel
magnetoresistance effect. Not even the sign of the TMR ratio has been
experimentally established. Here, we report on the magnetic properties of
epitaxial Fe$_3$O$_4$ films with various crystal orientations. The films
exhibited apparent crystal orientation dependence on hysteresis curves. In
particular, Fe$_3$O$_4$(110) films exhibited in-plane uniaxial magnetic
anisotropy. With respect to the squareness of hysteresis, Fe$_3$O$_4$ (111)
demonstrated the largest squareness. Furthermore, we fabricated MTJs with
Fe$_3$O$_4$(110) electrodes, and obtained an TMR effect of -12\% at RT. The
negative TMR ratio corresponded to the negative spin polarization of
Fe$_3$O$_4$ predicted from band calculations.",1406.1296v1
2014-06-05,Designing Asymmetric Multiferroics with Strong Magnetoelectric Coupling,"Multiferroics offer exciting opportunities for electric-field control of
magnetism. Unfortunately, single-phase multiferroics suitable for such
applications at room temperature has not been discovered. Here, we propose the
concept of a new type of multiferroics, namely, ""asymmetric multiferroic"". In
asymmetric multiferroics, two locally stable ferroelectric states are not
symmetrically equivalent, leading to different magnetic properties between
these two states. Furthermore, we predict from first-principles that a Fe-Cr-Mo
superlattice with the LiNbO3-type structure is such an asymmetric multiferroic.
The strong ferrimagnetism, high ferroelectric polarization, and significant
dependence of the magnetic transition temperature on polarization make this
asymmetric multiferroic an ideal candidate for realizing electric-field control
of magnetism at room temperature. Our study suggests that asymmetric
multiferroic may provide a new playground for voltage control of magnetism and
find its applications in spintronics and quantum computing.",1406.1318v1
2014-06-12,First-principles modelling of magnetic excitations in Mn12,"We have developed a fully microscopic theory of magnetic properties of the
prototype molecular magnet Mn12. First, the intra-molecular magnetic properties
have been studied by means of first-principles density functional-based
methods, with local correlation effects being taken into account within the
local density approximation plus U (LDA+U) approach. Using the magnetic force
theorem, we have calculated the interatomic isotropic and anisotropic exchange
interactions and full tensors of single-ion anisotropy for each Mn ion.
Dzyaloshinskii-Moriya (DM) interaction parameters turned out to be unusually
large, reflecting a low symmetry of magnetic pairs in molecules, in comparison
with bulk crystals. Based on these results we predict a distortion of
ferrimagnetic ordering due to DM interactions. Further, we use an exact
diagonalization approach allowing to work with as large Hilbert space dimension
as 10^8 without any particular symmetry (the case of the constructed magnetic
model). Based on the computational results for the excitation spectrum, we
propose a distinct interpretation of the experimental inelastic neutron
scattering spectra.",1406.3116v1
2014-06-28,Effects of Strain and Buffer Layer on Interfacial Magnetization in Sr$_2$CrReO$_6$ Films Determined by Polarized Neutron Reflectometry,"We have determined the depth-resolved magnetization structures of a series of
highly ordered Sr$_{2}$CrReO$_{6}$ (SCRO) ferrimagnetic epitaxial films via
combined studies of x-ray reflectometry, polarized neutron reflectometry and
SQUID magnetometry. The SCRO films deposited directly on
(LaAlO$_3$)$_{0.3}$(Sr$_2$AlTaO$_6$)$_{0.7}$ or SrTiO$_{3}$ substrates show
reduced magnetization of similar width near the interfaces with the substrates,
despite having different degrees of strain. When the SCRO film is deposited on
a Sr$_{2}$CrNbO$_{6}$ (SCNO) double perovskite buffer layer, the width the
interfacial region with reduced magnetization is reduced, agreeing with an
improved Cr/Re ordering. However, the relative reduction of the magnetization
averaged over the interfacial regions are comparable among the three samples.
Interestingly, we found that the magnetization suppression region is wider than
the Cr/Re antisite disorder region at the interface between SCRO and SCNO.",1406.7351v2
2015-12-02,Bose-Einstein Condensation of Magnons Pumped by the Bulk Spin Seebeck Effect,"We propose inducing Bose-Einstein condensation of magnons in a magnetic
insulator by a heat flow oriented toward its boundary. At a critical heat flux,
the oversaturated thermal gas of magnons accumulated at the boundary
precipitates the condensate, which then grows gradually as the thermal bias is
dialed up further. The thermal magnons thus pumped by the magnonic bulk (spin)
Seebeck effect must generally overcome both the local Gilbert damping
associated with the coherent magnetic dynamics as well as the radiative
spin-wave losses toward the magnetic bulk, in order to achieve the threshold of
condensation. We quantitatively estimate the requisite bias in the case of the
ferrimagnetic yttrium iron garnet, discuss different physical regimes of
condensation, and contrast it with the competing (so-called Doppler-shift) bulk
instability.",1512.00557v1
2015-12-11,Possible ferrimagnetism and ferroelectricity of half-substituted rare-earth titanate: a first-principles study on Y$_{0.5}$La$_{0.5}$TiO$_3$,"Titanates with the perovskite structure, including ferroelectrics (e.g.,
BaTiO$_3$) and ferromagnetic ones (e.g., YTiO$_3$), are important functional
materials. Recent theoretical studies predicted multiferroic states in strained
EuTiO$_3$ and titanate superlattices, the former of which has already been
experimental confirmed. Here, a first-principles calculation is performed to
investigate the structural, magnetic, and electronic properties of Y
half-substituted LaTiO3. Our results reveal that the magnetism of
Y$_{0.5}$La$_{0.5}$TiO$_3$ sensitively depends on its structural details
because of the inherent phase competition. The lowest energy state is the
ferromagnetic state, resulting in 0.25 $\mu_{\rm B}$/Ti. Furthermore, some
configurations of Y$_{0.5}$La$_{0.5}$TiO$_3$ exhibit hybrid improper
polarizations, which can be significantly affected by magnetism, resulting in
the multiferroic properties. Because of the quenching disorder of substitution,
the real Y$_{0.5}$La$_{0.5}$TiO3 material with random A-site ions may exhibit
interesting relaxor behaviors.",1512.03616v1
2016-05-24,Roles of heating and helicity in ultrafast all-optical magnetization switching in TbFeCo,"Using time-resolved magneto-optical Kerr effect (TR-MOKE) method,
helicity-dependent all-optical magnetization switching (HD-AOS) is observed in
ferrimagnetic TbFeCo films. The thermal effect and opto-magneto effects are
separately justified after single circularly polarized laser pulse. The
integral evolution of this ultrafast switching is characterized on different
time scales and the defined magnetization reversal time of 460 fs is the
fastest ever observed. Combining the heat effect and inverse Faraday effect
(IFE), micromagnetic simulations based on a single macro-spin model are
performed that reproduce HD-AOS following a linear reversal mechanism.",1605.07448v3
2016-05-30,"An integrated approach to doped thin films with strain tunable magnetic anisotropy: Powder synthesis, target preparation and pulsed laser deposition of Bi:YIG","We present a synthesis/processing method for fabricating ferrimagnetic
insulator (Bi-doped yttrium iron garnet) thin films with tunable magnetic
anisotropy. Since the desired magnetic properties rely on controllable
thickness and successful doping, we pay attention to the entire
synthesis/processing procedure (nanopowder synthesis, nanocrystalline target
preparation and pulsed laser deposition (PLD)). Atomically flat films were
deposited by PLD on (111)-orientated yttrium aluminum garnet. We show a
significant enhancement of perpendicular anisotropy in the films, caused by
strain-induced anisotropy. In addition, the perpendicular anisotropy is tunable
by decreasing the film thickness and overwhelms the shape anisotropy at a
critical thickness of 3.5 nm.",1605.09084v2
2016-05-31,The role of electron and phonon temperatures in the helicity-independent all-optical switching of GdFeCo,"Ultrafast optical heating of the electrons in ferrimagnetic metals can result
in all-optical switching (AOS) of the magnetization. Here we report
quantitative measurements of the temperature rise of GdFeCo thin films during
helicity-independent AOS. Critical switching fluences are obtained as a
function of the initial temperature of the sample and for laser pulse durations
from 55 fs to 15 ps. We conclude that non-equilibrium phenomena are necessary
for helicity-independent AOS, although the peak electron temperature does not
play a critical role. Pump-probe time-resolved experiments show that the
switching time increases as the pulse duration increases, with 10 ps pulses
resulting in switching times of ~sim 13 ps. These results raise new questions
about the fundamental mechanism of helicity-independent AOS.",1605.09764v3
2016-08-05,On supercurrents in Bose-Einstein magnon condensates in YIG ferrimagnet,"Recently E. Sonin commented [1] on our preprint ""Supercurrent in a room
temperature Bose-Einstein magnon condensate"" [2,3], arguing that our ""claim of
detection of spin supercurrent is premature and has not been sufficiently
supported by presented experimental results and their theoretical
interpretation."" We consider the appearance of this Comment as a sign of
significant interest into the problem of supercurrents in Bose-Einstein magnon
condensates. Here, we explicitly address E. Sonin's comments and show that our
interpretation of our experimental results as a detection of a magnon
supercurrent is fully supported not only by the experimental results
themselves, but also by independent theoretical analysis [4].",1608.01813v2
2016-08-25,Ferroelectricity-induced asymmetrical two-dimensional electron gas in superlattices consisteing of insulating GdTiO3 and ferroelectric BaTiO3,"Two-dimensional electron gas due to semiconductor interfaces can have high
mobility and exhibits superconductivity, magnetism, and other exotic properties
that are unexpected in constituent bulk materials. We study crystal structures,
electronic states, and magnetism of short-period (BTO)$_m$/(GTO)$_2$ ($m$=2 and
4) superlattices consisting of ferroelectric BaTiO$_3$ (BTO) and ferrimagnetic
insulating polar GdTiO$_3$ (GTO) by first principles calculations. Our
investigation shows that the middle Ti-O monolayer in the GTO layer becomes
metallic because the ferroelectricity in the insulating BTO layer induces an
inhomogeneous electric field against the polarity-produced electric field in
the GTO layer and thus differentially changes the d energy levels of the three
Ti-O monolayers related with the GTO layer. Through avoiding electron
reconstruction, the ferroelectric polarization also makes the electronic states
and magnetism of two interfacial Ti-O monolayers become substantially different
from those in the GTO/SrTiO$_3$ superlattices without ferroelectricity. Such
superlattices are interesting for potential spintronics applications because of
their unique asymmetrical two-dimensional electron-gas properties and possible
useful spin-orbit effects.",1608.07140v2
2016-12-20,Discovery of room temperature multiferroicity and magneto-electric coupling in Fe3Se4 nanorods,"We report for the first time, that Fe3Se4 is a room temperature, type-II
multiferroic with magnetoelectric coupling. We observed the coexistence of
coupled ferrimagnetic and ferroelectric ordering in Fe3Se4nanorods well above
room temperature, which is a hard magnet with large magnetocrystalline
anisotropy. For the first time, we observed spontaneous, reversible
ferroelectric polarization in Fe3Se4 nanorods below the magnetic Curie
temperature. The coupling is manifested by an anomaly in the dielectric
constant and Raman shift at Tc. We do not completely understand the origin of
the ferroelectric ordering at this point however the simultaneous presence of
magnetic and ferroelectric ordering at room temperature in Fe3Se4 along with
hard magnetic properties will open new research areas for devices.",1612.06512v2
2016-12-21,Giant ferroelectric polarization and electric reversal of strong spontaneous magnetization in multiferroic Bi2FeMoO6,"BiFeO$_3$ is the most famous multiferroic material, but it has no strong
spontaneous magnetization due to its antiferromagnetism. Here we show that
giant ferroelectric polarization and strong spontaneous magnetization can be
both realized in double perovskite Bi$_2$FeMoO$_6$ with R3 (\#146) space group
based on BiFeO$_3$. Our first-principles phonon spectra establishes that this
multiferroic R3 phase is stable. Our systematic calculations show that it is a
spin-polarized semiconductor with gap reaching to 0.54 eV and has a strong
ferroelectric polarization of 85$\mu$C/cm$^2$. This ferroelctricity is
comparable with that of BiFeO$_3$, but here obtained is a strong ferrimagnetism
with net magnetic moment of 2$\mu_B$ per formula unit and Curie temperature of
650 K. Both ferroelectric polarization and magnetic easy axis are shown to be
in pseudocubic [111] orientation. Our further analysis shows that the
macroscopic spontaneous magnetization can be deterministically reversed through
a three-step path by external electric field. Therefore, we believe that this
Bi$_2$FeMoO$_6$ material can be used to design new multifunctional materials
and achieve high-performance devices.",1612.07124v1
2016-12-28,"Magnetic structure of Cu2MnBO5 ludwigite: thermodynamic, magnetic properties and neutron diffraction study","We report on the thermodynamic, magnetic properties and the magnetic
structure of ludwigite-type Cu2MnBO5. The specific heat, the low-field
magnetization and the paramagnetic susceptibility were studied on a single
crystal and combined with powder neutron diffraction data. The temperature
dependence of the specific heat and the neutron diffraction pattern reveal a
single magnetic phase transition at T=92 K, which corresponds to the magnetic
ordering into a ferromagnetic phase. The cation distribution and the values and
directions of magnetic moments of ions in different crystallographic sites are
established. The magnetic moments of Cu2+ and Mn3+ ions occupying different
magnetic sites in the ferrimagnetic phase are pairwise antiparallel and their
directions do not coincide with the directions of the principal
crystallographic axes.The small value of the magnetic moment of copper ions
occupying site 2a is indicative of partial disordering of the magnetic moments
on this site. The magnetization measurements show a strong temperature
hysteresis of magnetization, which evidences for field-dependent transitions
below the phase transition temperature.",1612.08805v1
2016-12-29,Manipulating exchange bias using all-optical helicity-dependent switching,"Deterministic all-optical control of magnetization without an applied
magnetic field has been reported for different materials such as ferrimagnetic
and ferromagnetic thin films and granular recording media. These findings have
challenged the understanding of all-optical helicity-dependent switching of
magnetization and opened many potential applications for future magnetic
information, memory and storage technologies. Here we demonstrate optical
control of an antiferromagnetic layer through the exchange bias interaction
using the helicity of a femtosecond pulsed laser on IrMn/[Co/Pt]xN
antiferromagnetic/ ferromagnetic heterostructures. We show controlled switching
of the sign of the exchange bias field without any applied field, only by
changing the helicity of the light, and quantify the influence of the laser
fluence and the number of light pulses on the exchange bias control. We also
present the combined effect of laser pulses and applied magnetic field. This
study opens applications in spintronic devices where the exchange bias
phenomenon is routinely used to fix the magnetization orientation of a magnetic
layer in one direction.",1612.09338v1
2017-06-19,Spin Hall effect from hybridized 3$d$-4$p$ orbitals,"Electrical manipulation of magnetization by spin-orbit torque (SOT) has shown
promise for realizing reliable magnetic memories and oscillators. To date, the
generation of transverse spin current and SOT, whether it is of spin Hall
effect (SHE), Rashba-Edelstein effect or spin-momentum locking origin, relies
primarily on materials or heterostructures containing 5$d$ or 6$p$ heavy
elements with strong spin-orbit coupling. Here we show that a paramagnetic CoGa
compound possesses large enough spin Hall angle to allow robust SOT switching
of perpendicularly-magnetized ferrimagnetic MnGa films in CoGa/MnGa/Oxide
heterostructures. The spin Hall efficiency estimated via spin Hall
magnetoresistance and harmonic Hall measurements is +0.05$\pm$0.01, which is
surprisingly large for a system that does not contain any heavy metal element.
First-principles calculations corroborate our experimental observations and
suggest that the hybridized Co 3$d$ - Ga 4$p$ orbitals along R-X in the
Brillouin zone is responsible for the intrinsic SHE. Our results suggest that
efficient spin current generation can be realized in intermetallic by alloying
a transition metal with a $p$-orbital element and by Fermi level tuning.",1706.05846v1
2017-06-23,Detection of induced paramagnetic moments in Pt on Y$_3$Fe$_5$O$_{12}$ via x-ray magnetic circular dichroism,"Magnetic moments in an ultra-thin Pt film on a ferrimagnetic insulator
Y$_3$Fe$_5$O$_{12}$ (YIG) have been investigated at high magnetic fields and
low temperatures by means of X-ray magnetic circular dichroism (XMCD). We
observed an XMCD signal due to the magnetic moments in a Pt film at the Pt
$L_{3}$- and $L_{2}$-edges. By means of the element-specific magnetometry, we
found that the XMCD signal at the Pt $L_{3}$-edge gradually increases with
increasing the magnetic field even when the field is much greater than the
saturation field of YIG. Importantly, the observed XMCD intensity was found to
be much greater than the intensity expected from the Pauli paramagnetism of Pt
when the Pt film is attached to YIG. These results imply the emergence of
induced paramagnetic moments in Pt on YIG and explain the characteristics of
the unconventional Hall effect in Pt/YIG systems.",1706.07559v1
2017-07-07,Magnetoelectric antiferromagnets as platforms for the manipulation of solitons,"We study the magnetic dynamics of magnetoelectric antiferromagnetic thin
films, where an unconventional boundary ferromagnetism coexists with the bulk
N\'{e}el phase below the N\'{e}el temperature. The spin exchange between the
two order parameters yields an effective low-energy theory that is formally
equivalent to that of a ferrimagnet. Dynamics of domain walls and skyrmions are
analyzed within the collective variable approach, from which we conclude that
they behave as massive particles moving in a viscous medium subjected to a
gyrotropic force. We find that the film thickness can be used as a control
parameter for the motion of these solitons. In this regard, it is shown that an
external magnetic field can drive the dynamics of domain walls, whose terminal
velocity is tunable with the sample thickness. Furthermore, the classification
of the skyrmion dynamics is sensitive to the spatial modulation of the sample
thickness, which can be easily engineered with the present (thin-film)
deposition techniques. Current-driven spin transfer can trigger drifting orbits
of skyrmions, which can be utilized as racetracks for these magnetic textures.",1707.02374v1
2017-07-12,Broad line-width of antiferromagnetic spinwave due to electrons correlation,"We study magnetic excitations in a bilayer of an antiferromagnetic (AF)
insulator and a correlated metal, in which double occupancy is forbidden. The
effective action of the AF spin wave in the AF insulator is derived by using
the path integral formula within the second order of interplane coupling. The
electron correlation in the correlated metal is treated by the Gutzwiller
approximation, which renormalizes the hopping integrals by g_t as proportional
to the hole density. The linewidth of the AF spin wave excitations originates
from particle-hole excitations in the correlated metal. By increasing the
correlation effect, i.e., by decreasing g_t, it is found that the linewidth at
low energies increases inversely proportional to g_t. The present results will
also be useful for bilayers of a metal and ferrimagnet.",1707.03523v2
2017-07-21,Mn$_2$VAl Heusler alloy thin films: Appearance of antiferromagnetism and an exchange bias in a layered structure with Fe,"Mn$_2$VAl Heusler alloy films were epitaxially grown on MgO(100) single
crystal substrates by means of ultra-high-vacuum magnetron sputtering. A2 and
L2$_1$ type Mn$_2$VAl order was controlled by the deposition temperatures.
A2-type Mn$_2$VAl films showed no spontaneous magnetization and L2$_1$-type
Mn$_2$VAl films showed ferrimagnetic behavior with a maximum saturation
magnetization of 220 emu/cm$^3$ at room temperature. An antiferromagnetic
reflection was observed with neutron diffraction at room temperature for an
A2-type Mn$_2$VAl film deposited at 400$^\circ$C. A bilayer sample of the
antiferromagnetic A2 Mn$_2$VAl and Fe showed an exchange bias of 120 Oe at 10
K.",1707.06731v1
2017-07-23,A core-shell-surface layer model to explain the size dependence of effective magnetic anisotropy in magnetic nanoparticles,"The particle size (D) dependence of the effective magnetic anisotropy Keff of
magnetic nanoparticles (NPs) usually shows Keff increasing with decreasing D.
This dependence is often interpreted using the Eq.: Keff = Kb + (6Ks/D) where
Kb and Ks are the anisotropy constants of the spins in the bulk-like core and
surface layer, respectively. Here, we show that this model is inadequate to
explain the observed size-dependency of Keff for smaller nanoparticles with D <
5 nm. Instead the results in NPs of maghemite ({\gamma}-Fe2O3), NiO and Ni are
best described by an extension of the above model leading to the variation
given by Keff = Kb + (6Ks/D) +Ksh{[1-(2d/D)]^(-3) -1}, where the last term is
due to the spins in a shell of thickness d with anisotropy Ksh. The validation
of this core-shell-surface layer (CSSL) model for three different magnetic NPs
systems viz. ferrimagnetic {\gamma}-Fe2O3, ferromagnetic Ni and
antiferromagnetic NiO suggests its possible applicability for all magnetic
nanoparticles.",1707.07241v1
2017-10-05,First-principles and model simulation of all-optical spin reversal,"All-optical spin switching is a potential trailblazer for information storage
and communication at an unprecedented fast rate and free of magnetic fields.
However, the current wisdom is largely based on semiempirical models of
effective magnetic fields and heat pulses, so it is difficult to provide
high-speed design protocols for actual devices. Here, we carry out a massively
parallel first-principles and model calculation for thirteen spin systems and
magnetic layers, free of any effective field, to establish a simpler and
alternative paradigm of laser-induced ultrafast spin reversal and to point out
a path to a full-integrated photospintronic device. It is the interplay of the
optical selection rule and sublattice spin orderings that underlines seemingly
irreconcilable helicity-dependent/independent switchings. Using realistic
experimental parameters, we predict that strong ferrimagnets, in particular,
Laves phase C15 rare-earth alloys, meet the telecommunication energy
requirement of 10 fJ, thus allowing a cost-effective subpicosecond laser to
switch spin in the GHz region.",1710.01834v1
2017-10-11,Approaching quantum anomalous Hall effect in proximity-coupled YIG/graphene/h-BN sandwich structure,"Quantum anomalous Hall state is expected to emerge in Dirac electron systems
such as graphene under both sufficiently strong exchange and spin-orbit
interactions. In pristine graphene, neither interaction exists; however, both
interactions can be acquired by coupling graphene to a magnetic insulator (MI)
as revealed by the anomalous Hall effect. Here, we show enhanced magnetic
proximity coupling by sandwiching graphene between a ferrimagnetic insulator
yttrium iron garnet (YIG) and hexagonal-boron nitride (h-BN) which also serves
as a top gate dielectric. By sweeping the top-gate voltage, we observe Fermi
level-dependent anomalous Hall conductance. As the Dirac point is approached
from both electron and hole sides, the anomalous Hall conductance reaches 1/4
of the quantum anomalous Hall conductance 2e2/h. The exchange coupling strength
is determined to be as high as 27 meV from the transition temperature of the
induced magnetic phase. YIG/graphene/h-BN is an excellent heterostructure for
demonstrating proximity-induced interactions in two-dimensional electron
systems.",1710.04179v1
2017-12-12,Substitution- and Strain-induced Magnetic Phase Transition in Iron Carbide,"Cementite-type carbides are of interest for magnetocaloric applications owing
to their temperature- or pressure-induced magnetic phase transition. Here,
using first-principles calculations, we investigate the magnetism and the
magnetic phase transition in iron carbide (Fe3C) with the substitution of Cr
atoms at Fe sites with the strain effect. The presence of Cr atoms is found to
give rise to a second-order magnetic phase transition from a ferromagnetic
phase for Fe3C to a nonmagnetic phase in chromium carbide (Cr3C).While the
ternary Fe2CrC and Cr2FeC compounds prefer the ferrimagnetic ground state, the
magnitudes of both the Fe and Cr spin moments, which are antiparallel in
orientation, decrease as x increases in Fe3-xCrxC (x = 0, 1, 2, and 3).
Furthermore, the fixed spin-moment calculations indicate that the magnetization
of Fe3-xCrxC compounds can be delicately altered via the strain effect and that
the magnetic-nonmagnetic phase transition occurs at an early stage of Cr
substitution, x = 2.",1712.04128v1
2017-12-14,Theoretical prediction of a two-dimensional intrinsic double-metal ferromagnetic semiconductor MnCoO4,"A two-dimensional double-metal oxide MnCoO4 was predicted to be an intrinsic
ferromagnetic semiconductor by using density functional theory. The low
cleavage energy 0.36 Jm-2, which is similar to that of graphene, indicates that
it can be easily exfoliated. The bulk structure has an antiferromagnetic ground
state while the ferromagnetic configuration is the ground state against two
antiferromagnetic and three ferrimagnetic configurations in the two-dimensional
structure. The spin flip gaps for valence and conduction bands are 0.41 and
0.10 eV calculated with the HSE06 density functional, which are much larger
than the thermal energy at room temperature. The Curie temperature obtained
from the Monte Carlo simulation is 40 K. Under 9% tensile strain, the spin flip
gaps increase largely so that the spin flip can be suppressed. The direct
antiferromagnetic coupling between the Mn and Co atoms reduces largely while
the indirect ferromagnetic couplings between two Mn or two Co atoms mediated by
the O atoms do not decrease much in the stretched structure. The Curie
temperature increases to 230 K, higher than the dry ice temperature. Moreover,
phonon dispersion indicates that the MnCoO4 is also stable under the tensile
stain. Therefore, two-dimensional MnCoO4 could be a good candidate for
low-dimensional spintronics.",1712.05071v1
2017-12-31,Proper dissipative torques in antiferromagnetic dynamics,"There is little doubt that the magnetization dynamics of ferromagnetic
systems is governed by the Landau-Lifshitz-Gilbert equation or its
generalization with various spin torques. In contrast, there are several sets
of dynamic equations for two-sublattice antiferromagnets (AFMs) in literature
that have different forms of dissipative torques and no proper dynamic
equations for multi-sublattice AFMs and ferrimagnets in general. Here we
introduce the general Rayleigh dissipation functional into the Lagrange
equation and derive the proper form of the dissipative torques in the
phenomenological equations for the AFMs with multiple sublattices. A new type
of dissipative torque arising from inter-sublattice drag effect is discovered
that has important influences on magnon lifetime and domain wall motion. In
particular, our theory unifies different dynamic equations of AFMs in
literature.",1801.00217v1
2018-01-24,Quantization of magnetoelectric fields,"The effect of quantum coherence involving macroscopic degree of freedom, and
occurring in systems far larger than individual atoms are one of the topical
fields in modern physics. Because of material dispersion, a phenomenological
approach to macroscopic quantum electrodynamics, where no canonical formulation
is attempted, is used. The problem becomes more complicated when geometrical
forms of a material structure have to be taken into consideration. Magnetic
dipolar mode (MDM) oscillations in a magnetically saturated quasi 2D ferrite
disk are macroscopically quantized states. In this ferrimagnetic structure,
long range dipole dipole correlation in positions of electron spins can be
treated in terms of collective excitations of a system as a whole. The near
fields in the proximity of a MDM ferrite disk have space and time symmetry
breakings. Such MDM-originated fields, called magnetoelectric (ME) fields,carry
both spin and orbital angular momentums. By virtue of unique topology, ME
fields are different from free space electromagnetic (EM) fields. The ME fields
are quantum fluctuations in vacuum. We call these quantized states ME photons.
There are not virtual EM photons. We show that energy, spin and orbital angular
momenta of MDM oscillations constitute the key physical quantities that
characterize the ME field configurations. We show that vacuum can induce a
Casimir torque between a MDM ferrite disk, metal walls, and dielectric samples.",1801.08042v1
2018-01-30,Engineering Surface Critical Behavior of (2+1)-Dimensional O(3) Quantum Critical Points,"Surface critical behavior (SCB) refers to the singularities of physical
quantities on the surface at the bulk phase transition. It is closely related
to and even richer than the bulk critical behavior. In this work, we show that
three types of SCB universality are realized in the dimerized Heisenberg models
at the (2+1)-dimensional O(3) quantum critical points by engineering the
surface configurations. The ordinary transition happens if the surface is
gapped in the bulk disordered phase, while the gapless surface state generally
leads to the multicritical special transition, even though the latter is
precluded in classical phase transitions because the surface is in the lower
critical dimension. An extraordinary transition is induced by the ferrimagnetic
order on the surface of the staggered Heisenberg model, in which the surface
critical exponents violate the results of the scaling theory and thus seriously
challenge our current understanding of extraordinary transitions.",1801.10035v2
2018-09-07,Integrating all-optical switching with spintronics,"All-optical switching (AOS) of magnetic materials describes the reversal of
the magnetization using short (femtosecond) laser pulses, and has been observed
in a variety of materials. In the past decade it received extensive attention
due to its high potential for fast and energy-efficient data writing in future
spintronic memory applications. Unfortunately, the AOS mechanism in the
ferromagnetic multilayers commonly used in spintronics needs multiple pulses
for the magnetization reversal, losing its speed and energy efficiency. Here,
we experimentally demonstrate `on-the-fly' single-pulse AOS in combination with
spin Hall effect (SHE) driven motion of magnetic domains in Pt/Co/Gd
synthetic-ferrimagnetic racetracks. Moreover, using field-driven-SHE-assisted
domain wall (DW) motion measurements, both the SHE efficiency in the racetrack
is determined and the chirality of the optically written DW's is verified. Our
experiments demonstrate that Pt/Co/Gd racetracks facilitate both single-pulse
AOS as well as efficient SHE induced domain wall motion, which might ultimately
pave the way towards integrated photonic memory devices.",1809.02347v1
2018-10-02,Spin-dependent (inverse) spin Hall effect in Co$_{60}$Fe$_{20}$B$_{20}$,"In ferromagnetic metals, the interconversion of spin and charge currents via
the spin Hall effect and its inverse can depend on the angle between the
ferromagnets magnetization and the spin current polarization direction. Here,
such a spin-dependent (inverse) spin Hall effect is found in the ferromagnetic
alloy Co$_{60}$Fe$_{20}$B$_{20}$. In a nonlocal magnon transport experiment,
Co$_{60}$Fe$_{20}$B$_{20}$ is used to both excite and detect magnonic spin
currents flowing in the ferrimagnetic insulator Y$_{3}$Fe$_{5}$O$_{12}$. We
find that the signal amplitude is significantly modulated by tuning the
direction of the Co$_{60}$Fe$_{20}$B$_{20}$ magnetization. We design a sample
structure that completely prevents direct magnonic coupling between the
ferromagnets. Thus, we can identify unambiguously an intrinsic electronic
origin of the observed effect.",1810.01227v3
2018-10-31,Millimeter-sized magnetic domains in perpendicularly magnetized ferrimagnetic Mn4N thin films grown on SrTiO3,"The use of epitaxial layers for domain wall-based spintronic applications is
often hampered by the presence of pinning sites. Here, we show that when
depositing Mn4N(10 nm) epitaxial films, the replacement of MgO(001) by
SrTiO3(001) substrates allows minimizing the misfit, and to obtain an improved
crystalline quality, a sharper switching, a full remanence, a high anisotropy
and remarkable millimeter-sized magnetic domains, with straight and smooth
domain walls. In a context of rising interest for current-induced domain wall
motion in rare",1810.13184v1
2019-06-03,Oxygen-vacancy induced magnetic phase transitions in multiferroic thin films,"Multiferroics in which giant ferroelectric polarization and magnetism coexist
are of tremendous potential for engineering disruptive applications in
information storage and energy conversion. Yet the functional properties of
multiferroics are thought to be affected detrimentally by the presence of point
defects, which may be abundant due to the volatile nature of some constituent
atoms and high temperatures involved in materials preparation. Here, we
demonstrate with theoretical methods that oxygen vacancies may enhance the
functionality of multiferroics by radically changing their magnetic
interactions in thin films. Specifically, oxygen vacancies may restore missing
magnetic super-exchange interactions in large axial ratio phases, leading to
full antiferromagnetic spin ordering, and induce the stabilization of
ferrimagnetic states with a significant net magnetization of 0.5 uB per formula
unit. Our theoretical study should help to clarify the origins of long-standing
controversies in bismuth ferrite and improve the design of technological
applications based on multiferroics.",1906.01117v1
2019-06-04,Thickness dependence of spin Peltier effect visualized by thermal imaging technique,"Magnon propagation length in a ferrimagnetic insulator yttrium iron garnet
(YIG) has been investigated by measuring and analyzing the YIG-thickness t_YIG
dependence of the spin Peltier effect (SPE) in a Pt/YIG junction system. By
means of the lock-in thermography technique, we measured the spatial
distribution of the SPE-induced temperature modulation in the Pt/YIG system
with the t_YIG gradation, allowing us to obtain the accurate t_YIG dependence
of SPE with high t_YIG resolution. Based on the t_YIG dependence of SPE, we
verified the applicability of several phenomenological models to estimate the
magnon diffusion length in YIG.",1906.01560v3
2019-06-20,Purely magnetic logic based on polarized spin waves,"Spin wave, the precession of magnetic order in magnetic materials, is a
collective excitation that carries spin angular momentum. Similar to the
acoustic or optical waves, the spin wave also possesses the polarization degree
of freedom. Although such polarization degrees of freedom are frozen in
ferromagnets, they are fully unlocked in antiferromagnets or ferrimagnets. Here
we introduce the concept of magnetic gating and demonstrate a spin wave analog
of the Datta-Das spin transistor in antiferromagnet. Utilizing the interplay
between polarized spin wave and the antiferromagnetic domain walls, we propose
a universal logic gate of pure magnetic nature, which realizes all Boolean
operations in one single magnetic structure. We further construct a full
functional 4-bit Arithmetic Logic Unit using only sixteen spin wave universal
logic gates, operating in a weaving fashion as a Jacquard loom machine. The
spin wave-based architecture proposed here also sets a model for the future
energy efficient non-volatile computing, the distributed processing-in-memory
computing, and the evolvable neuromorphic computing.",1906.08702v1
2019-06-24,Electrical and magnetic properties of thin films of the spin-filter material CrVTiAl,"The spin-filter material CrVTiAl is a promising candidate for producing
highly spin-polarized currents at room temperature in a nonmagnetic
architecture. Thin films of compensated-ferrimagnetic CrVTiAl have been grown
and their electrical and magnetic properties have been studied. The resistivity
shows two-channel semiconducting behavior with one disordered gapless channel
and a gapped channel with activation energy $\Delta E$=~0.1~-~0.2~eV.
Magnetoresistance measurements to B~=~35~T provide values for the mobilities of
the gapless channel, leading to an order of magnitude difference in the carrier
effective masses, which are in reasonable accord with our
density-functional-theory based results. The density of states and electronic
band structure is computed for permutations of the four sublattices arranged
differently along the (111) body diagonal, yielding metallic (Cr-V-Al-Ti),
spin-gapless (Cr-V-Ti-Al) and spin-filtering (Cr-Ti-V-Al) phases. Robustness of
the spin-gapless phase to substitutional disorder is also considered.",1906.10222v1
2019-06-26,Fermi Level Dependent Spin Pumping from a Magnetic Insulator into a Topological Insulator,"Topological spintronics aims to exploit the spin-momentum locking in the
helical surface states of topological insulators for spin-orbit torque devices.
We address a fundamental question that still remains unresolved in this
context: does the topological surface state alone produce the largest values of
spin-charge conversion efficiency or can the strongly spin-orbit coupled bulk
states also contribute significantly? By studying the Fermi level dependence of
spin pumping in topological insulator/ferrimagnetic insulator bilayers, we show
that the spin Hall conductivity is constant when the Fermi level is tuned
across the bulk band gap, consistent with a full bulk band calculation. The
results suggest a new perspective, wherein ""bulk-surface correspondence"" allows
spin-charge conversion to be simultaneously viewed either as coming from the
full bulk band, or from spin-momentum locking of the surface state.",1906.11116v1
2019-07-02,Entanglement entropy in low-energy field theories at finite chemical potential,"We investigate the leading area-law contribution to entanglement entropy in a
system described by a general Lagrangian with O(2) symmetry containing first-
and second-order time derivatives, namely breaking the Lorentz-invariance. We
establish a connection between the Higgs gap present in a symmetry-broken phase
and the area-law term for the entanglement entropy in the general,
non-relativistic case. Our predictions for the entanglement entropy and
correlation length are successfully compared to numerical results in two
paradigmatic systems: the Mott insulator to superfluid transition for ultracold
lattice bosons, and the ground state of ferrimagnetic systems.",1907.01204v2
2019-07-05,Supraferromagnetic correlations in clusters of magnetic nanoflowers,"Magnetic nanoflowers are densely packed aggregates of superferromagnetically
coupled iron oxide nanocrystallites, which excel during magnetic hyperthermia
experiments. Here, we investigate the nature of the moment coupling within a
powder of such nanoflowers using spin-resolved small-angle neutron scattering.
Within the powder the nanoparticles are agglomerated to clusters, and we can
show that the moments of neighboring nanoflowers tend to align parallel to each
other. Thus, the whole system resembles a hierarchical magnetic nanostructure
consisting of three distinct levels, i.e. (i) the ferrimagnetic
nanocrystallites as building blocks, (ii) the superferromagnetic nanoflowers,
and (iii) the \textit{supra}ferromagnetic clusters of nanoflowers. We surmise
that such a supraferromagnetic coupling explains the enhanced magnetic
hyperthermia performance in case of interacting nanoflowers.",1907.02752v2
2019-07-10,Mechanism for a Chemical Potential of Nonequilibrium Magnons in Parametric Parallel Pumping,"We demonstrate how a magnon chemical potential is generated in parametric
parallel pumping. We study how a time-periodic magnetic field of this pumping
affects magnon properties of a ferrimagnet in a nonequilibrium steady state. We
show that the magnon distribution function of our nonequilibrium steady state
becomes the Bose distribution function with $\mu=\omega_{\textrm{p}}/2$, where
$\mu$ is the magnon chemical potential and $\omega_{\textrm{p}}$ is the pumping
frequency. This result is distinct from the absence of the magnon chemical
potential in the standard theory and can qualitatively explain its generation
in experiments. We believe our result is a first theoretical demonstration of
the generation of the magnon chemical potential in the parametric parallel
pumping, providing an important step towards a thorough understanding of
properties of nonequilibrium magnons.",1907.04552v1
2019-07-12,Electrical current switching of the noncollinear antiferromagnet Mn$_3$GaN,"We report electrical current switching of noncollinear antiferromagnetic
(AFM) Mn$_3$GaN/Pt bilayers at room temperature. The Hall resistance of these
bilayers can be manipulated by applying a pulse current of
$1.5\times10^6$~A/cm$^2$, whereas no significant change is observed up to
$\sim10^8$~A/cm$^2$ in Mn$_3$GaN single films, indicating that the Pt layer
plays an important role. In comparison with ferrimagnetic Mn$_3$GaN/Pt
bilayers, a lower electrical current switching of noncollinear AFM Mn$_3$GaN is
demonstrated, with a critical current density two orders of magnitude smaller.
Our results highlight that a combination of a noncollinear AFM antiperovskite
nitride and a spin-torque technique is a good platform of AFM spintronics.",1907.05544v1
2019-07-18,Compensation in the spin-1/2 site diluted Ising ferrimagnet: A Monte Carlo study,"A two-dimensional spin-1/2 trilayer magnetic system with quenched
non-magnetic impurity is studied. The lattice is formed by alternate layers of
two different theoretical atoms A and B arranged in a particular fashion A-B-A.
The compensation point appears below the critical temperature, for which total
magnetization of the system becomes zero even though the sublattice
magnetization has a nonzero value. For a range of values of the relative
interaction strength in the Hamiltonian, a compensation point is observed. We
considered the Ising mechanics and employed the Monte Carlo method to determine
the compensation point and critical temperature of the system. However, the
effects of impurity in such systems are still not well studied. With that in
mind, we address the effects of random non-magnetic impurity in the trilayer
system. We also investigate the lattice morphologies in the presence of
compensation and dilution and finally obtain the three-dimensional phase
diagram for selected Hamiltonian parameters and impurity concentration.",1907.07879v5
2019-07-24,Electron doping induced magnetic glassy state in phase separated YBaCo$_2$O$_{5.5-δ}$,"The structural, magnetic and transport properties of the layered
RBaCo$_2$O$_{5.5}$ cobaltites are sensitive to the oxygen stoichiometry. In
this present study, we report the presence of a low-temperature magnetic glassy
state in electron-doped polycrystalline YBaCo$_2$O$_{5.5}$ cobaltite. The ac
magnetization studies show the absence of conventional spin glass features,
while the various dc magnetization studies demonstrate the presence of
non-equilibrium magnetic glassy state at low temperature. The magnetic glassy
state of this sample results from the kinetic arrest of the first order ferro
(or ferri) to antiferromagnetic transition. The role of electron doping in the
occurrence of magnetic glassy phenomena is discussed in terms of magnetic phase
separation involving the Co3+/Co2+ clusters of the ferrimagnetic phase in the
Co3+/Co3+ antiferromagnetic matrix.",1907.10248v1
2019-07-31,Large spin Hall magnetoresistance in antiferromagnetic α-Fe2O3/Pt heterostructures,"We investigate the spin Hall magnetoresistance (SMR) at room temperature in
thin film heterostructures of antiferromagnetic, insulating, (0001)-oriented
alpha-Fe2O3 (hematite) and Pt. We measure their longitudinal and transverse
resistivities while rotating an applied magnetic field of up to 17T in three
orthogonal planes. For out-of-plane magnetotransport measurements, we find
indications for a multidomain antiferromagnetic configuration whenever the
field is aligned along the film normal. For in-plane field rotations, we
clearly observe a sinusoidal resistivity oscillation characteristic for the SMR
due to a coherent rotation of the Neel vector. The maximum SMR amplitude of
0.25% is, surprisingly, twice as high as for prototypical ferrimagnetic
Y3Fe5O12/Pt heterostructures. The SMR effect saturates at much smaller magnetic
fields than in comparable antiferromagnets, making the alpha-Fe2O3/Pt system
particularly interesting for room-temperature antiferromagnetic spintronic
applications.",1907.13393v4
2019-10-01,Weyl nodes and magnetostructural instability in antiperovskite Mn$_3$ZnC,"The ferromagnetic phase of the cubic antiperovskite Mn$_3$ZnC is suggested
from first-principles calculation to be a nodal line Weyl semimetal. Features
in the electronic structure that are the hallmark of a nodal line Weyl state, a
large density of linear band crossings near the Fermi level, can also be
interpreted as signatures of a structural and/or magnetic instability. Indeed,
it is known that Mn$_3$ZnC undergoes transitions upon cooling from a
paramagnetic to a cubic ferromagnetic state under ambient conditions and then
further into a non-collinear ferrimagnetic tetragonal phase at a temperature
between 250$\,$K and 200$\,$K. The existence of Weyl nodes and their
destruction via structural and magnetic ordering is likely to be relevant to a
range of magnetostructurally coupled materials.",1910.00184v2
2019-10-02,Phase diagrams and critical behaviours of the mixed spin-5/2 and spin-7/2 Ising system,"We used mean-field theory based on the Bogoliubov inequality for the Gibbs
free energy to examine the magnetic properties of a mixed spin-5/2 and spin-7/2
Blume-Capel ferrimagnetic system. The thermal behaviours of the system
magnetization are classified according to the extended N\'eel nomenclature. The
system exhibits compensation phenomena where a complete cancellation of
sublattice magnetizations is observed below the critical temperature.
Temperature-dependent phase diagrams are constructed for the case of unequal
sublattice crystal field interactions. Under appropriate conditions, our
calculations reveal first-order transitions in addition to second-order ones
previously observed in Monte Carlo simulations.",1910.00908v1
2019-10-24,Zero Field Cooled Exchange Bias Effect in Nano-Crystalline Mg-Ferrite Thin Film,"I report, Zero Field Cooled (ZFC) Exchange Bias (EB) effect in a single phase
nanocrystalline Mg-ferrite thin film, deposited on an amorphous quartz
substrate using pulsed laser ablation technique. The film showed a high ZFC EB
shift (HE~ 190 Oe) at 5 K. The ZFC EB shift decreased with increasing
temperature and disappeared at higher temperatures (T > 70 K). This Mg-ferrite
thin film also showed Conventional Exchange Bias (CEB) effect, but unlike many
CEB systems, the film showed decrease in the coercivity (HC) under the Field
Cooled (FC) measurements. The film also showed training effect in ZFC
measurements which followed the frozen spin relaxation behaviour. The observed
exchange bias could be attributed to the pinning effect of the surface spins of
frozen glassy states at the interface of large ferrimagnetic grains.",1910.10948v1
2019-10-25,Local magnetic anisotropy by polarized neutron powder diffraction: application of magnetically induced preferred crystallite orientation,"Polarized neutron diffraction allows to determine the local susceptibility
tensor on the magnetic site both in single crystals and powders. It is widely
used in the studies of single crystals, but it is still hardly applicable to a
number of highly interesting powder materials, like molecular magnets or
nanoscale systems because of the low luminosity of existing instruments and the
absence of an appropriate data analysis software. We show that these
difficulties can be overcome by using a large area detector in combination with
the two-dimensional Rietveld method and powder samples with magnetically
induced preferred crystallite orientation. This is demonstrated by revisiting
two test powder compounds, namely, low anisotropy (soft) ferrimagnetic compound
Fe3O4 and spin-ice compound Ho2Ti2O7 with high local anisotropy. The values of
magnetic moments in Fe3O4 and the susceptibility tensors of Ho2Ti2O7 at various
temperatures and fields were found in perfect agreement with these found
earlier in single crystal experiments. The magnetically induced preferred
crystallite orientation was used to study the local susceptibility of a
single-molecule magnet Co([(CH3)2N]2CS)2Cl2. Hence, the studies of local
magnetic anisotropy in powder systems might now become accessible.",1910.11822v1
2020-01-09,"High temperature thermal cycling effect on the irreversible responses of lattice structure, magnetic properties and electrical conductivity in Co$_{2.75}$Fe$_{0.25}$O$_{4+δ}$ spinel oxide","We report high temperature synchrotron X-ray diffraction (SXRD), dc
magnetization and current-voltage (I-V) characteristics for the samples of
Co$_{2.75}$Fe$_{0.25}$O$_4$ ferrite. The material was prepared by chemical
reaction of the Fe and Co nitrate solutions at pH = 11 and subsequent annealing
at temperatures 200 0C, 500 0C and 900 0C. The measurements were performed by
cycling the temperature from 300 K to high temperature (warming mode) and
return back to 300 K (cooling mode). The SXRD patterns indicated a fine
bi-phased cubic spinel structure in the highly Co rich spinel oxide.
Magnetization curves showed intrinsic ferrimagnetic features and defect induced
additional ferromagnetic phase at higher temperatures. Electrical conductivity
showed thermal hysteresis loop between warming and cooling modes of temperature
variation. The samples exhibited new information on the irreversibility
phenomena of lattice structure, magnetization and electrical conductivity on
cycling the measurement temperatures.",2001.02829v2
2020-04-04,Lattice distortion in TmCo$_2$: a poly- and single- crystal study,"Within the RCo$_2$ family of compounds, a structural distortion linked with
the onset of magnetic ordering around the critical temperature can be observed.
One of the less explored RCo$_2$ compounds is TmCo$_2$ probably due to its low
Curie temperature. Exceptionally this compound, given its position at the end
of the ferrimagnetic series, shows discrepancies in the ordering of the Co
sub-lattice because of a weak Weiss molecular field. In this paper we focus on
the structural distortion in TmCo$_2$, which appears together with the magnetic
ordering around the critical temperature of $T_{C}\sim3.6$~K. Poly-crystals as
well as single-crystals of TmCo$_2$ were used in our experiments. For both
kinds of samples we observed the same type of the rhombohedral distortion along
the [111] direction from the cubic Fd$\bar{3}$m to R$\bar{3}$m space group. The
relation between observed magnetic and structural properties in this compound
is discussed.",2004.01938v1
2020-04-07,Optomagnonic Barnett effect,"Combining the technologies of quantum optics and magnonics, we find that the
circularly polarized laser can dynamically realize the quasiequilibrium magnon
Bose-Einstein condensates (BEC). The Zeeman coupling between the laser and
spins generates the optical Barnett field, and its direction is controllable by
switching the laser chirality. We show that the optical Barnett field develops
the total magnetization in insulating ferrimagnets with reversing the local
magnetization, which leads to the quasiequilibrium magnon BEC. This
laser-induced magnon BEC transition through optical Barnett effect, dubbed the
optomagnonic Barnett effect, provides an access to coherent magnons in the high
frequency regime of the order of terahertz. We also propose a realistic
experimental setup to observe the optomagnonic Barnett effect using current
device and measurement technologies as well as the laser chirping. The
optomagnonic Barnett effect is a key ingredient for the application to
ultrafast spin transport.",2004.03353v2
2020-04-11,Brillouin Light Scattering of Spin Waves Inaccessible with Free-Space Light,"Micro-focus Brillouin light scattering is a powerful technique for the
spectroscopic and spatial characterization of elementary excitations in
materials. However, the small momentum of light limits the accessible
excitations to the center of the Brillouin zone. Here, we utilize a metallic
nanoantenna fabricated on the archetypal ferrimagnet yttrium iron garnet to
demonstrate the possibility of Brillouin light scattering from
large-wavevector, high-frequency spin wave excitations that are inaccessible
with free-space light. The antenna facilitates sub-diffraction confinement of
electromagnetic field, which enhances the local field intensity and generates
momentum components significantly larger than those of free-space light. Our
approach provides access to high frequency spin waves important for fast
nanomagnetic devices, and can be generalized to other types of excitations and
light scattering techniques.",2004.05314v1
2020-12-01,Design of an optomagnonic crystal: towards optimal magnon-photon mode matching at the microscale,"We put forward the concept of an optomagnonic crystal: a periodically
patterned structure at the microscale based on a magnetic dielectric, which can
co-localize magnon and photon modes. The co-localization in small volumes can
result in large values of the photon-magnon coupling at the single quanta
level, which opens perspectives for quantum information processing and quantum
conversion schemes with these systems. We study theoretically a simple geometry
consisting of a one-dimensional array of holes with an abrupt defect,
considering the ferrimagnet Yttrium Iron Garnet (YIG) as the basis material. We
show that both magnon and photon modes can be localized at the defect, and use
symmetry arguments to select an optimal pair of modes in order to maximize the
coupling. We show that an optomagnonic coupling in the kHz range is achievable
in this geometry, and discuss possible optimization routes in order to improve
both coupling strengths and optical losses.",2012.00760v2
2020-12-08,Mean field theory and Monte Carlo simulation of Phase transitions and Magnetic Properties of a tridimensional Fe7S8 Compound,"The structural, electronic and magnetic properties of Fe7S8 material have
been studied within the framework of the ab-initio calculations, the mean field
approximation (MFA) and Monte Carlo simulation (MCS). Our study shows that two
forms of the iron atoms, Fe2+ with spin S=2, and Fe3+ with spin {\sigma}=5/2
are the most probable configurations. A mixed Ising model with ferromagnetic
spin coupling between Fe2+ and Fe3+ ions and between Fe3+ and Fe3+ ions, and
with antiferromagnetic spin coupling between Fe2+ ions of adjacent layers has
been used to study the magnetic properties of this compound. We demonstrated
that the magnetic phase transition can be either of the first or of the second
order, depending on the value of the exchange interaction and crystal field.
The presence of vacancies in every second iron layer leads to incomplete
cancellation of magnetic moments, hence to the emergence of the ferrimagnetism.
Anomalies in the magnetization behavior have been found and compared with the
experimental results.",2012.04306v1
2020-12-21,Inverse Faraday Effect in an Optomagnonic Waveguide,"Single-mode high-index-contrast waveguides have been ubiquitously exploited
in optical, microwave, and phononic structures for achieving enhanced
wave-matter interactions. Although micro-scale optomechanical and
electro-optical devices have been widely studied, optomagnonic devices remain a
grand challenge at the microscale. Here, we introduce a planar optomagnonic
waveguide platform based on a ferrimagnetic insulator that simultaneously
supports single transverse mode of spin waves (magnons) and highly confined
optical modes. The co-localization of spin and light waves gives rise to
enhanced inverse Faraday effect, and as a result, magnons are excited by an
effective magnetic field generated by interacting optical photons. Moreover,
the strongly enhanced optomagnonic interaction allows us to observe such effect
using low-power (milliwatt level) light signals in the continuous-wave form, as
opposed to high-intensity (megawatt peak power) light pulses that are typically
required in magnetic bulk materials or thin films. The optically-driven magnons
are detected electrically with preserved phase coherence, showing the
feasibility for launching spin waves with low-power continuous optical fields.",2012.11119v2
2021-01-04,"Electronic, magnetic and optical properties of penta-BN$_2$ nanoribbons: a first principles study","The search for new materials is a very intense task in many technological
areas. In 2015, a new variant of graphene was proposed, the pentagraphene,
which was followed by the propose of a pentagonal boron nitride structure
called penta-BN$_2$. Based on these structures, we investigated the electronic,
magnetic, and optical properties of penta-BN$_2$ nanoribbons (p-BNNRs)
considering four different kinds of edges, carefully closing the valence shells
with H atoms to prevent dangling bonds. To achieve this goal, we used
first-principles calculations in a density functional theory framework. Our
findings showed that the p-BNNRs have a rich magneto-electronic behavior,
varying from semiconductor to half-metal. We obtained that they are
ferrimagnetic, having an intrinsic magnetism, which allow potential
applications in spintronic or spinwaves. From an optical absorption point of
view, they mainly absorb at ultraviolet region of the spectrum, especially at
UV-B region, which could indicate a potential application as a UV filter.",2101.00879v1
2021-01-07,Quantum annealing simulation of out-of-equilibrium magnetization in a spin-chain compound,"Geometrically frustrated spin-chain compounds such as Ca3Co2O6 exhibit
extremely slow relaxation under a changing magnetic field. Consequently, both
low-temperature laboratory experiments and Monte Carlo simulations have shown
peculiar out-of-equilibrium magnetization curves, which arise from trapping in
metastable configurations. In this work we simulate this phenomenon in a
superconducting quantum annealing processor, allowing us to probe the impact of
quantum fluctuations on both equilibrium and dynamics of the system. Increasing
the quantum fluctuations with a transverse field reduces the impact of
metastable traps in out-of-equilibrium samples, and aids the development of
three-sublattice ferrimagnetic (up-up-down) long-range order. At equilibrium we
identify a finite-temperature shoulder in the 1/3-to-saturated phase
transition, promoted by quantum fluctuations but with entropic origin. This
work demonstrates the viability of dynamical as well as equilibrium studies of
frustrated magnetism using large-scale programmable quantum systems, and is
therefore an important step toward programmable simulation of dynamics in
materials using quantum hardware.",2101.02769v1
2021-01-07,Squeezing Microwaves by Magnetostriction,"Squeezed light finds many important applications in quantum information
science and quantum metrology, and has been produced in a variety of physical
systems involving optical nonlinear processes. Here, we show how a nonlinear
magnetostrictive interaction in a ferrimagnet in cavity magnomechanics can be
used to reduce quantum noise of the electromagnetic field. We show optimal
parameter regimes where a substantial and stationary squeezing of the microwave
output field can be achieved. The scheme can be realized within the reach of
current technology in cavity electromagnonics and magnomechanics. Our work
provides a new and practicable approach for producing squeezed vacuum states of
electromagnetic fields, and may find promising applications in quantum
information processing and quantum metrology.",2101.02796v3
2021-01-16,Universal Critical Exponents of the Magnetic Domain Wall Depinning Transition,"Magnetic field driven domain wall dynamics in a ferrimagnetic GdFeCo thin
film with perpendicular magnetic anisotropy is studied using low temperature
magneto-optical Kerr microscopy. Measurements performed in a practically
athermal condition allow for the direct experimental determination of the
velocity ($ \beta = 0.30 \pm 0.03 $) and correlation length ($ \nu = 1.3 \pm
0.3 $) exponents of the depinning transition. The whole family of exponents
characterizing the transition is deduced, providing evidence that the depinning
of magnetic domain walls is better described by the quenched Edwards-Wilkinson
universality class.",2101.06555v3
2012-05-08,Theory of High T$_c$ Ferrimagnetism in a Multi-orbital Mott Insulator,"We propose a model for the multi-orbital material Sr$_2$CrOsO$_6$ (SCOO), an
insulator with remarkable magnetic properties and the highest $T_c \simeq 725$
K among {\em all} perovskites with a net moment. We derive a new criterion for
the Mott transition $(\widetilde{U}_{1} \widetilde{U}_{2})^{1/2}>2.5W$ using
slave rotor mean field theory, where $W$ is the bandwidth and
$\widetilde{U}_{1(2)}$ are the effective Coulomb interactions on Cr(Os)
including Hund's coupling. We show that SCOO is a Mott insulator, where the
large Cr $\widetilde{U}_{1}$ compensates for the small Os $\widetilde{U}_{2}$.
The spin sector is described by a frustrated antiferromagnetic Heisenberg model
that naturally explains the net moment arising from canting and also the
observed non-monotonic magnetization $M(T)$. We predict characteristic magnetic
structure factor peaks that can be probed by neutron experiments.",1205.1811v2
2012-05-22,Partial disorder in an Ising-spin Kondo lattice model on a triangular lattice,"Phase diagram of an Ising-spin Kondo lattice model on a triangular lattice
near 1/3-filling is investigated by Monte Carlo simulation. We identify a
partially disordered phase with coexistence of magnetic order and paramagnetic
moments, which was unstable in two-dimensional Ising models with localized
spins only. The partial disorder emerges in the competing regime between a
twosublattice stripe phase and three-sublattice ferrimagnetic phase, at finite
temperatures above an electronic phase separation. The peculiar magnetic
structure accompanies a charge order and develops a gap in the electronic
structure. The results manifest a crucial role of the nonperturbative interplay
between spin and charge degrees of freedom in stabilizing the partial disorder.",1205.4826v1
2012-05-31,Magnetic Nanoparticles in the Interstellar Medium: Emission Spectrum and Polarization,"The presence of ferromagnetic or ferrimagnetic nanoparticles in the
interstellar medium would give rise to magnetic dipole radiation at microwave
and submm frequencies. Such grains may account for the strong mm-wavelength
emission observed from a number of low-metallicity galaxies, including the
Small Magellanic Cloud. We show how to calculate the absorption and scattering
cross sections for such grains, with particular attention to metallic Fe,
magnetite Fe3O4, and maghemite gamma-Fe2O3, all potentially present in the
interstellar medium. The rate of Davis-Greenstein alignment by magnetic
dissipation is also estimated. We determine the temperature of free-flying
magnetic grains heated by starlight and we calculate the polarization of the
magnetic dipole emission from both free-fliers and inclusions. For inclusions,
the magnetic dipole emission is expected to be polarized orthogonally relative
to the normal electric dipole radiation. Finally, we present self-consistent
dielectric functions for metallic Fe, magnetite Fe3O4, and maghemite
gamma-Fe2O3, enabling calculation of absorption and scattering cross sections
from microwave to X-ray wavelengths.",1205.7021v2
2017-04-29,Theory of magnetism in La$_2$NiMnO$_6$,"The magnetism of ordered and disordered La$_2$NiMnO$_6$ is explained using a
model involving double exchange and superexchange. The concept of majority spin
hybridization in the large coupling limit is used to explain the ferromagnetism
of La$_2$NiMnO$_6$ as compared to the ferrimagnetism of Sr$_{2}$FeMoO$_{6}$.
The ferromagnetic insulating ground state in the ordered phase is explained.
The essential role played by the Ni-Mn superexchange between the Ni $e_{g}$
electron spins and the Mn $t_{2g}$ core electron spins in realizing this ground
state, is outlined. In presence of antisite disorder, the model system is found
to exhibit a tendency of becoming a spin-glass at low temperatures, while it
continues to retain a ferromagnetic transition at higher temperatures, similar
to recent experimental observations [D. Choudhury .et.al., Phys. Rev. Lett.
108, 127201 (2012)]. This reentrant spin-glass or reentrant ferromagnetic
behaviour is explained in terms of the competition of the ferromagnetic double
exchange between the Ni $e_{g}$ and the Mn $e_{g}$ electrons, and the
ferromagnetic Ni-Mn superexchange, with the antiferromagnetic antisite Mn-Mn
superexchange.",1705.00177v2
2017-05-08,"Re-entrant spin-glass freezing and magneto-dielectric behavior of Li3NiRuO6, a layered rock-salt related oxide","We report the results of neutron diffraction, ac and dc magnetization,
heat-capacity, complex permittivity, and pyrocurrent measurements on an oxide,
Li3NiRuO5, hitherto not paid much attention in the literature, except for a
previous report on its promising electrochemical performance. We emphasize on
the following findings: (i) Observation of re-entrant spin-glass behavior; that
is, this oxide undergoes ferrilmagnetic ordering below 8- K, entering
spin-glass regime around 12 K. (ii) There is no prominent feature in the
complex dielectric permittivity (in particular, at the magnetic transitions) in
the absence of external magnetic field, indicative of the absence of
ferroelectricity. However, there is a distinct evidence for magneto-dielectric
(MDE) coupling. The sign of MDE coupling also changes as the sample is cooled
from ferrimagnetic state to spin-glass regime. (iii) There are pyroelectric
anomalies in the vicinity of 30-70 K, presumably from thermally stimulated
depolarization current.",1705.02868v1
2017-05-18,The Final Chapter In The Saga Of YIG,"The magnetic insulator Yttrium Iron Garnet can be grown with exceptional
quality, has a ferrimagnetic transition temperature of nearly 600 K, and is
used in microwave and spintronic devices that can operate at room temperature.
The most accurate prior measurements of the magnon spectrum date back nearly 40
years, but cover only 3 of the lowest energy modes out of 20 distinct magnon
branches. Here we have used time-of-flight inelastic neutron scattering to
measure the full magnon spectrum throughout the Brillouin zone. We find that
the existing model of the excitation spectrum, well known from an earlier work
titled ""The Saga of YIG"", fails to describe the optical magnon modes. Using a
very general spin Hamiltonian, we show that the magnetic interactions are both
longer-ranged and more complex than was previously understood. The results
provide the basis for accurate microscopic models of the finite temperature
magnetic properties of Yttrium Iron Garnet, necessary for next-generation
electronic devices.",1705.06594v1
2017-05-25,Monte Carlo study of an anisotropic Ising multilayer with antiferromagnetic interlayer couplings,"We present a Monte Carlo study of the magnetic properties of an Ising
multilayer ferrimagnet. The system consists of two kinds of non-equivalent
planes, one of which is site-diluted. All intralayer couplings are
ferromagnetic. The different kinds of planes are stacked alternately and the
interlayer couplings are antiferromagnetic. We perform the simulations using
the Wolff algorithm and employ multiple histogram reweighting and finite-size
scaling methods to analyze the data with special emphasis on the study of
compensation phenomena. Compensation and critical temperatures of the system
are obtained as functions of the Hamiltonian parameters and we present a
detailed discussion about the contribution of each parameter to the presence or
absence of the compensation effect. A comparison is presented between our
results and those reported in the literature for the same model using the pair
approximation. We also compare our results with those obtained through both the
pair approximation and Monte Carlo simulations for the bilayer system.",1705.10192v2
2017-05-30,Focused issue on antiferromagnetic spintronics: An overview (Part of a collection of reviews on antiferromagnetic spintronics),"This focused issue attempts to provide a comprehensive introduction into the
field of antiferromagnetic spintronics. Apart from the brief overview below, it
features five review articles. The intention is to cover in a coherent and
complementary way key physical aspects of the antiferromagnetic spintronics
research. These range from microelectronic memory devices and optical
manipulation and detection of antiferromagnetic spins, to the fundamentals of
antiferromagnetic dynamics in uniform or spin-textured systems, and to the
interplay of antiferromagnetic spintronics with topological phenomena. The
antiferromagnetic ordering can take a number of forms including fully
compensated collinear, non-collinear, and non-coplanar magnetic lattices,
compensated and uncompensated ferrimagnets, or metamagnetic materials hosting
an antiferromagnetic to ferromagnetic phase transition. Apart from the variety
of distinct magnetic crystal structures, the focused issue also encompasses
spintronic phenomena and devices studied in antiferromagnet/ferromagnet
heterostructures and in synthetic antiferromagnets.",1705.10489v1
2017-09-12,Direct observation of magnon-phonon coupling in yttrium iron garnet,"The magnetic insulator yttrium iron garnet (YIG) with a ferrimagnetic
transition temperature of $\sim$560 K has been widely used in microwave and
spintronic devices. Anomalous features in the spin Seeback effect (SSE)
voltages have been observed in Pt/YIG and attributed to the magnon-phonon
coupling. Here we use inelastic neutron scattering to map out low-energy spin
waves and acoustic phonons of YIG at 100 K as a function of increasing magnetic
field. By comparing the zero and 9.1 T data, we find that instead of splitting
and opening up gaps at the spin wave and acoustic phonon dispersion
intersecting points, magnon-phonon coupling in YIG enhances the hybridized
scattering intensity. These results are different from expectations of
conventional spin-lattice coupling, calling for new paradigms to understand the
scattering process of magnon-phonon interactions and the resulting
magnon-polarons.",1709.03940v1
2017-09-21,Current-induced magnetization switching using electrically-insulating spin-torque generator,"Current-induced magnetization switching through spin-orbit torques (SOTs) is
the fundamental building block of spin-orbitronics. The SOTs generally arise
from the spin-orbit coupling of heavy metals. However, even in a
heterostructure where a metallic magnet is sandwiched by two different
insulators, a nonzero current-induced SOT is expected because of the broken
inversion symmetry; an electrical insulator can be a spin-torque generator.
Here, we demonstrate current-induced magnetization switching using an
insulator. We show that oxygen incorporation into the most widely used
spintronic material, Pt, turns the heavy metal into an electrically-insulating
generator of the SOTs, enabling the electrical switching of perpendicular
magnetization in a ferrimagnet sandwiched by electrically-insulating oxides. We
further found that the SOTs generated from the Pt oxide can be controlled
electrically through voltage-driven oxygen migration. These findings open a
route towards energy-efficient, voltage-programmable spin-orbit devices based
on solid-state switching of heavy metal oxidation.",1709.07127v1
2017-09-26,Magnetic-field-induced suppression of spin Peltier effect in Pt/${\rm Y_{3}Fe_{5}O_{12}}$ system at room temperature,"We report the observation of magnetic-field-induced suppression of the spin
Peltier effect (SPE) in a junction of a paramagnetic metal Pt and a
ferrimagnetic insulator ${\rm Y_{3}Fe_{5}O_{12}}$ (YIG) at room temperature.
For driving the SPE, spin currents are generated via the spin Hall effect from
applied charge currents in the Pt layer, and injected into the adjacent thick
YIG film. The resultant temperature modulation is detected by a commonly-used
thermocouple attached to the Pt/YIG junction. The output of the thermocouple
shows sign reversal when the magnetization is reversed and linearly increases
with the applied current, demonstrating the detection of the SPE signal. We
found that the SPE signal decreases with the magnetic field. The observed
suppression rate was found to be comparable to that of the spin Seebeck effect
(SSE), suggesting the dominant and similar contribution of the low-energy
magnons in the SPE as in the SSE.",1709.08997v1
2018-03-07,Ultra-Fast Ferrimagnetic All Spin Logic Device,"All spin logic device (ASLD) blazes an alternative path for realizing
ultra-low power computing in the Post-Moore era. However, initial device
structure relying on ferromagnetic input/output and spin transfer torque (STT)
driven magnetization switching degrades its performance and even hinders its
realization. In this paper, we propose an ASLD based on rare-earth
(RE)-transition-metal (TM) ferromagnetic alloy that can achieve an ultra-high
frequency up to terahertz. The spin orbit torque (SOT) induced fast precession
near the spin angular momentum compensated point is investigated through the
macrospin model. Combining the non-local spin current diffusing from the input
to the output, a deterministic picosecond switching can be realized without any
external magnetic field. Our results show that ASLD has the potential to exceed
the performance of mainstream computing.",1803.02552v1
2018-03-09,Strong anomalous Nernst effect in collinear magnetic Weyl semimetals without net magnetic moments,"We predict a large anomalous Nernst effect in the inverse Heusler compensated
ferrimagnets Ti$_2$Mn$X$ ($X$=Al,Ga,In) with vanishing net magnetic moments.
Though the net magnetic moment is zero, the Weyl points in these systems lead
to a large anomalous Nernst conductivity (ANC) due to the lack of a magnetic
sublattice that inverses the sign of the Berry curvature. In comparison to the
noncollinear antiferromagnets Mn$_3$Sn and Mn$_3$Ge, the high ANC stems almost
entirely from the Weyl points in this class of compounds, and thus, it is
topologically protected. This work shows for the first time a large ANC with
zero net magnetic moments in collinear systems, which is helpful for
comprehensive understanding of the thermoelectric effect in zero-moment
magnetic materials and its further applications.",1803.03439v3
2018-03-13,Spin wave localization and guiding by magnon band structure engineering in yttrium iron garnet,"In spintronics the propagation of spin-wave excitations in magnetically
ordered materials can also be used to transport and process information. One of
the most popular materials in this regard is the ferrimagnetic insulator
yttrium-iron-garnet due its exceptionally small spin-wave damping parameter.
While the small relaxation rate allows for large propagation length of magnetic
excitations, it also leads to non-locality of the magnetic properties. By
imaging spin waves their band structure is mapped. In doing so wave vector
selection is shown to suppress dispersion effects to a large extent allowing
for local measurements of spin relaxation. Moreover we demonstrate even higher
control of magnon propagation by employing the wave vector selectivity near an
avoided crossing of different spin-wave modes where the group velocity
approaches zero. Here local engineering of the dispersion allows constructing
magnonic waveguides and at the same time reveals the local relaxation
properties.",1803.04943v3
2018-06-01,Dirac-Surface-State Modulated Spin Dynamics in a Ferrimagnetic Insulator at Room Temperature,"This work demonstrates dramatically modified spin dynamics of magnetic
insulator (MI) by the spin-momentum locked Dirac surface states of the adjacent
topological insulator (TI) which can be harnessed for spintronic applications.
As the Bi-concentration x is systematically tuned in 5 nm thick (BixSb1-x)2Te3
TI film, the weight of the surface relative to bulk states peaks at x = 0.32
when the chemical potential approaches the Dirac point. At this concentration,
the Gilbert damping constant of the precessing magnetization in 10 nm thick
Y3Fe5O12 MI film in the MI/TI heterostructures is enhanced by an order of
magnitude, the largest among all concentrations. In addition, the MI acquires
additional strong magnetic anisotropy that favors the in-plane orientation with
similar Bi-concentration dependence. These extraordinary effects of the Dirac
surface states distinguish TI from other materials such as heavy metals in
modulating spin dynamics of the neighboring magnetic layer.",1806.00151v1
2018-06-07,Terahertz Emission from Compensated Magnetic Heterostructures,"Terahertz emission spectroscopy (TES) has recently played an important role
in unveiling the spin dynamics at a terahertz (THz) frequency range. So far,
ferromagnetic (FM)/nonmagnetic (NM) heterostructures have been intensively
studied as THz sources. Compensated magnets such as a ferrimagnet (FIM) and
antiferromagnet (AFM) are other types of magnetic materials with interesting
spin dynamics. In this work, we study TES from compensated magnetic
heterostructures including CoGd FIM alloy or IrMn AFM layers. Systematic
measurements on composition and temperature dependences of THz emission from
CoGd/Pt bilayer structures are conducted. It is found that the emitted THz
field is determined by the net spin polarization of the laser induced spin
current rather than the net magnetization. The temperature robustness of the
FIM based THz emitter is also demonstrated. On the other hand, an AFM plays a
different role in THz emission. The IrMn/Pt bilayer shows negligible THz
signals, whereas Co/IrMn induces sizable THz outputs, indicating that IrMn is
not a good spin current generator, but a good detector. Our results not only
suggest that a compensated magnet can be utilized for robust THz emission, but
also provide a new approach to study the magnetization dynamics especially near
the magnetization compensation point.",1806.02517v1
2018-07-18,Magnon-photon-phonon entanglement in cavity magnomechanics,"We show how to generate tripartite entanglement in a cavity magnomechanical
system which consists of magnons, cavity microwave photons, and phonons. The
magnons are embodied by a collective motion of a large number of spins in a
macroscopic ferrimagnet, and are driven directly by an electromagnetic field.
The cavity photons and magnons are coupled via magnetic dipole interaction, and
the magnons and phonons are coupled via magnetostrictive (radiation
pressure-like) interaction. We show optimal parameter regimes for achieving the
tripartite entanglement where magnons, cavity photons, and phonons are
entangled with each other, and we further prove that the steady state of the
system is a genuinely tripartite entangled state. The entanglement is robust
against temperature. Our results indicate that cavity magnomechanical systems
could provide a promising platform for the study of macroscopic quantum
phenomena.",1807.07158v3
2018-07-23,Bias dependent spin injection into graphene on YIG through bilayer hBN tunnel barriers,"We study the spin injection efficiency into single and bilayer graphene on
the ferrimagnetic insulator Yttrium-Iron-Garnet (YIG) through an exfoliated
tunnel barrier of bilayer hexagonal boron nitride (hBN). The contacts of two
samples yield a resistance-area product between 5 and 30 k$\Omega\mu$m$^2$.
Depending on an applied DC bias current, the magnitude of the non-local spin
signal can be increased or suppressed below the noise level. The spin injection
efficiency reaches values from -60% to +25%. The results are confirmed with
both spin valve and spin precession measurements. The proximity induced
exchange field is found in sample A to be (85 $\pm$ 30) mT and in sample B
close to the detection limit. Our results show that the exceptional spin
injection properties of bilayer hBN tunnel barriers reported by Gurram et al.
are not limited to fully encapsulated graphene systems but are also valid in
graphene/YIG devices. This further emphasizes the versatility of bilayer hBN as
an efficient and reliable tunnel barrier for graphene spintronics.",1807.08481v1
2018-07-25,Role of interfaces in the biased composition of TbFe(Co) thin films,"Ferrimagnetic TbFe or TbFeCo amorphous alloy thin films have been grown by
co-evaporation in ultra-high vacuum. They exhibit an out-of-plane magnetic
anisotropy up to their Curie temperature with a nucleation and propagation
reversal mechanism suitable for current induced domain wall motion. Rutherford
back scattering experiments confirmed a fine control of the Tb depth-integrated
composition within the evaporation process. However, a large set of
experimental techniques were used to evidence an interface related contribution
in such thin films as compared to much thicker samples. In particular, scanning
transmission electron microscopy experiments evidence a depth dependent
composition and perturbed top and bottom interfaces with preferential oxidation
and diffusion of terbium. Despite of that, amorphous and homogeneous alloy film
remains in a bulk-like part. The composition of that bulk-like part of the
magnetic layer, labeled as effective composition, is biased when compared with
the depth-integrated composition. The magnetic properties of the film are
mostly dictated by this effective composition, which we show changes with
different top and bottom interfaces.",1807.09570v1
2018-07-27,Optimization of Multi-Frequency Magnonic Waveguides with Enhanced Group Velocities by Exchange Coupled Ferrimagnet/Ferromagnet Bilayers,"We report broadband spectroscopy and numerical analysis by which we explore
propagating spin waves in a magnetic bilayer consisting of a 23 nm thick
permalloy film deposited on 130 nm thick $Y_{3}Fe_{5}O_{12}$. In the bilayer,
we observe a characteristic mode that exhibits a considerably larger group
velocity at small in-plane magnetic field than both the magnetostatic and
perpendicular standing spin waves. Using the finite element method, we confirm
the observations by simulating the mode profiles and dispersion relations. They
illustrate the hybridization of spin wave modes due to exchange coupling at the
interface. The high-speed propagating mode found in the bilayer can be utilized
to configure multi-frequency spin wave channels enhancing the performance of
spin wave based logic devices.",1807.10508v2
2018-07-30,Investigating the magnetic ground state of the skyrmion host material Cu$_{2}$OSeO$_{3}$ using long-wavelength neutron diffraction,"We present long-wavelength neutron diffraction data measured on both single
crystal and polycrystalline samples of the skyrmion host material
Cu$_{2}$OSeO$_{3}$. We observe magnetic satellites around the $(0\bar{1}1)$
diffraction peak not accessible to other techniques, and distinguish helical
from conical spin textures in reciprocal space. We confirm successive
transitions from helical to conical to field polarised ordered spin textures as
the external magnetic field is increased. The formation of a skyrmion lattice
with propagation vectors perpendicular to the field direction is observed in a
region of the field-temperature phase diagram that is consistent with previous
reports. Our measurements show that not only the field-polarised phase but also
the helical ground state are made up of ferrimagnetic clusters instead of
individual spins. These clusters are distorted Cu tetrahedra, where the spin on
one Cu ion is anti-aligned with the spin on the three other Cu ions.",1807.11333v1
2018-08-03,"Structural, Ferroelectric, Magnetic and Magnetoelectric Response in Multiferroic (1-x)Bi(Ni1/2Ti1/2)O3-PbTiO3/xNi0.6Zn0.4Fe2O4 Particulate Composites","Multiferroic particulate composites have been fabricated by taking the
morphotropic phase boundary composition of ferroelectric phase
Bi(Ni1/2Ti1/2)O3-PbTiO3 and magnetic phase (Ni,Zn)Fe2O4. The ferroelectric
phase has coexisting monoclinic and tetragonal perovskite structures with space
group Pm and P4mm, respectively whereas the magnetic phase has spinel cubic
structure with space group Fd3m. Rietveld structural analysis for the each
components of composite reveals that the tetragonality (c/a) of the
ferroelectric phase continuously increases with increasing the concentration of
magnetic phase suggesting partial ionic diffusion between ferroelectric and
magnetic phases, after composite formation. Composition dependent M\""ossbauer
spectra of (1-x)Bi(Ni1/2Ti1/2)O3-PbTiO3/x(Ni,Zn)Fe2O4 reveals the
superparamagnetic like behavior for the ferroelectric rich composition with
x=0.2. The magnetic ordering increases for the composition with x=0.4 and 0.6
which completely transform into ferrimagnetic for the composition with x=0.9
for the magnetic phase rich compositions. Unlike the ferroelectric or magnetic
components which do not exhibit the magnetoelectric response separately, large
value of magnetoelectric coefficient (30 mV/Oe-cm) in
(1-x)Bi(Ni1/2Ti1/2)O3-PbTiO3/xNi0.6Zn0.4Fe2O4 composite makes it promise for
multifunctional applications.",1808.01148v1
2018-08-15,Ground state with nonzero spontaneous magnetization of the two-dimensional spin-1/2 Heisenberg antiferromagnet with frustration,"The S = 1/2 Heisenberg antiferromagnet on the two-dimensional pyramid lattice
is studied by the numerical-diagonalization method. This lattice is obtained by
the combination of the Lieb lattice and the square lattice. It is known that
when interaction on the square lattice is increased from the ferrimagnetic
limit of strong interaction on the Lieb lattice, this system shows gradual
decrease and disappearance of spontaneous magnetization in the ground state.
The present study treats the region near the case of the square-lattice
antiferromagnet accompanied by isolated spins by numerical-diagonalization
calculations of finite-size clusters with the maximum size of 39 sites. Our
numerical results suggest the existence of a new phase with small but nonzero
spontaneous magnetization between two zero-spontaneous-magnetization phases.",1808.04997v1
2018-08-20,On the order of the phase transition in the spin-1 Baxter-Wu model,"In this work we investigate the order of the phase transition of the spin-1
Baxter-Wu model. We used extensive entropic simulations to describe the
behavior of quantities which reveal the order of the phase transition. We
applyied finite-sizing scaling laws for continuous and discontinuous phase
transitions. Our results show that this system exhibits an indeterminacy
regarding the order of the phase transition, i.e., the results are conclusive
for both transitions, whether continuous or discontinuous. In such a scenario
we carried out a study of the configurations in the region of the phase
transition, which confirmed that the model seems to undergo a tetracritical
transition, with the coexistence of a ferromagnetic and three ferrimagnetic
configurations, suggesting that it may be a multicritical point belonging to a
critical line of an external or a crystalline fields, where the continuous and
the discontinuous phase transitions may coexist reflecting different features
of the system",1808.06701v1
2018-08-23,First harmonic measurements of the spin Seebeck effect,"We present measurements of the spin Seebeck effect (SSE) by a technique that
combines alternating currents (AC) and direct currents (DC). The method is
applied to a ferrimagnetic insulator/heavy metal bilayer,
Y$_3$Fe$_5$O$_{12}$(YIG)/Pt. Typically, SSE measurements use an AC current to
produce an alternating temperature gradient and measure the voltage generated
by the inverse spin-Hall effect in the heavy metal at twice the AC frequency.
Here we show that when Joule heating is associated with AC and DC bias
currents, the SSE response occurs at the frequency of the AC current drive and
can be larger than the second harmonic SSE response. We compare the first and
second harmonic responses and show that they are consistent with the SSE. The
field dependence of the voltage response is used to characterize the
damping-like and field-like torques. This method can be used to explore
nonlinear thermoelectric effects and spin dynamics induced by temperature
gradients.",1808.07813v1
2018-08-29,Critical behavior and magnetocaloric effect in Mn$_3$Si$_2$Te$_6$,"The critical properties and magnetocaloric effect of semiconducting
ferrimagnet Mn$_3$Si$_2$Te$_6$ single crystals have been investigated by bulk
magnetization and heat capacity around $T_c$. Critical exponents $\beta =
0.41\pm0.01$ with a critical temperature $T_c = 74.18\pm0.08$ K and $\gamma =
1.21\pm0.02$ with $T_c = 74.35\pm0.05$ K are deduced by the Kouvel-Fisher plot,
whereas $\delta = 4.29\pm0.05(3.40\pm0.02)$ is obtained by a critical isotherm
analysis at $T = 74(75)$ K. The magnetic exchange distance is found to decay as
$J(r)\approx r^{-4.79}$, which lies between the mean-field and 3D Heisenberg
models. Moreover, the magnetic entropy change $-\Delta S_M$ features a maximum
at $T_c$, i.e., $-\Delta S_M^{max} \sim$ 2.53(1.67) J kg$^{-1}$ K$^{-1}$ with
in-plane(out-of-plane) field change of 5 T, confirming large magnetic
anisotropy. The heat capacity measurement further gives $-\Delta S_M^{max}$
$\sim$ 2.94 J kg$^{-1}$ K$^{-1}$ and the corresponding adiabatic temperature
change $\Delta T_{ad}$ $\sim$ 1.14 K with out-of-plane field change of 9 T.",1808.09949v1
2018-12-05,Spin-imbalance-induced transverse magnetization in the Hofstadter-Hubbard model,"The fermionic, time-reversal invariant Hofstadter-Hubbard model with a
population difference between the two spin states is investigated. In the
strongly interacting regime, where the system can be described by an effective
spin model, we find an exotic spin structure by means of classical Monte-Carlo
calculations. Remarkably, this spin structure exhibits a transverse net
magnetization perpendicular to the magnetization induced by the population
imbalance. It is thus inherently different from canted antiferromagnetism. We
further investigate effects of quantum fluctuations within the dynamical
mean-field approximation and obtain a rich phase diagram including
ferromagnetic, anti-ferromagnetic, ferrimagnetic, and transverse magnetization
phases.",1812.02001v2
2018-12-24,Interfacial Spin Seebeck effect in noncollinear magnetic systems,"The interplay between spin and heat currents at magnetic
insulator|nonmagnetic metal interfaces has been a subject of much scrutiny
because of both fundamental physics and the promise for technological
applications. While ferrimagnetic and, more recently, antiferromagnetic systems
have been extensively investigated, a theory generalizing the heat-to-spin
interconversion in noncollinear magnets is still lacking. Here, we establish a
general framework for thermally-driven spin transport at the interface between
a noncollinear magnet and a normal metal. Modeling the interfacial coupling
between localized and itinerant magnetic moments via an exchange Hamiltonian,
we derive an expression for the spin current, driven by a temperature
difference, for an arbitrary noncollinear magnetic order. Our theory reproduces
previously obtained results for ferromagnetic and antiferromagnet systems.",1812.09890v2
2019-01-15,"Group theoretical analysis of structural instability, vacancy ordering and magnetic transitions in the system troilite (FeS) - pyrrhotite (Fe$_{1-x}$S)","A group-theoretical framework to describe vacancy ordering and magnetism in
the Fe$_{1-x}$S system is developed. This framework is used to determine the
sequence of crystal structures consistent with the observed magnetic structures
of troilite (FeS), and to determine the crystallographic nature of the
low-temperature Besnus transition in Fe$_{0.875}$S. We conclude that the Besnus
transition is a magnetically driven transition characterised by the rotation of
the moments out of the ac-plane, accompanied by small atomic displacements that
lower the symmetry to triclinic at low temperatures. Based on our phase
diagram, we predict related magnetically driven phase transitions at low
temperatures in all the commensurate superstructures of pyrrhotite. The exact
nature of the transition is determined by the symmetry of the vacancy ordered
state Based on this we predict spin-flop transitions in 3C and 5C pyrrhotite
and a transition akin to the Besnus transition in 6C pyrrhotite. Furthermore,
we clarify that 3C and 4C pyrrhotite carry a ferrimagnetic moment whereas 5C
and 6C are antiferromagnetic.",1901.04756v1
2019-01-18,Magnonic Weyl states in Cu2OSeO3,"The multiferroic ferrimagnet Cu$_2$OSeO$_3$ with a chiral crystal structure
attracted a lot of recent attention due to the emergence of magnetic skyrmion
order in this material. Here, the topological properties of its magnon
excitations are systematically investigated by linear spin-wave theory and
inelastic neutron scattering. When considering Heisenberg exchange interactions
only, two degenerate Weyl magnon nodes with topological charges $\pm$2 are
observed at high-symmetry points. Each Weyl point splits into two as the
symmetry of the system is further reduced by including into consideration the
nearest-neighbor Dzyaloshinsky-Moriya interaction, crucial for obtaining an
accurate fit to the experimental spin-wave spectrum. The predicted topological
properties are verified by surface state and Chern number analysis.
Additionally, we predict that a measurable thermal Hall conductivity can be
associated with the emergence of the Weyl points, the position of which can be
tuned by changing the crystal symmetry of the material.",1901.06192v1
2019-01-21,The magnetic structure and spin-flop transition in the A-site columnar-ordered quadruple perovskite $\mathrm{TmMn_3O_6}$,"We present the magnetic structure of $\mathrm{TmMn_3O_6}$, solved via neutron
powder diffraction - the first such study of any $R\mathrm{Mn_3O_6}$ A-site
columnar-ordered quadruple perovskite to be reported. We demonstrate that long
range magnetic order develops below 74 K, and at 28 K a spin-flop transition
occurs driven by $f$-$d$ exchange and rare earth single ion anisotropy. In both
magnetic phases the magnetic structure may be described as a collinear
ferrimagnet, contrary to conventional theories of magnetic order in the
manganite perovskites. Instead, we show that these magnetic structures can be
understood to arise due to ferro-orbital order, the A, A$'$ and A$''$ site
point symmetry, $mm2$, and the dominance of A-B exchange over both A-A and B-B
exchange, which together are unique to the $R\mathrm{Mn_3O_6}$ perovskites.",1901.06874v1
2019-01-25,Focused ion beam modification of non-local magnon-based transport in yttrium iron garnet/platinum heterostructures,"We study the impact of Ga ion exposure on the local and non-local
magnetotransport response in heterostructures of the ferrimagnetic insulator
yttrium iron garnet and platinum. In particular, we cut the yttrium iron garnet
layer in between two electrically separated wires of platinum using a Ga ion
beam, and study the ensuing changes in the magnetoresistive response. We find
that the non-local magnetoresistance signal vanishes when the yttrium iron
garnet film between the Pt wires is fully cut, although the local spin Hall
magnetoresistance signal remains finite. This observation corroborates the
notion that pure spin currents carried by magnons are crucial for the non-local
magnetotransport effects observed in magnetic insulator/metal nanostructures.",1901.08894v1
2019-01-27,Computational search for ultrasmall and fast skyrmions in the Inverse Heusler family,"Skyrmions are magnetic excitations that are potentially ultrasmall and
topologically protected, making them interesting for high-density
all-electronic ultrafast storage applications. While recent experiments have
confirmed the existence of various types of skyrmions, their typical sizes are
much larger than traditional domain walls, except at very low temperature. In
this work, we explore the optimal material parameters for hosting ultra-small,
fast, and room temperature stable skyrmions. As concrete examples, we explore
potential candidates from the inverse Heusler family. Using first-principles
calculations of structural and magnetic properties, we identify several
promising ferrimagnetic inverse Heusler half-metal/near half-metals and analyze
their phase space for size and metastability.",1901.09446v1
2019-03-06,Microwave magnon damping in YIG films at millikelvin temperatures,"Magnon systems used in quantum devices require low damping if coherence is to
be maintained. The ferrimagnetic electrical insulator yttrium iron garnet (YIG)
has low magnon damping at room temperature and is a strong candidate to host
microwave magnon excitations in future quantum devices. Monocrystalline YIG
films are typically grown on gadolinium gallium garnet (GGG) substrates. In
this work, comparative experiments made on YIG waveguides with and without GGG
substrates indicate that the material plays a significant role in increasing
the damping at low temperatures. Measurements reveal that damping due to
temperature-peak processes is dominant above 1 K. Damping behaviour that we
show can be attributed to coupling to two-level fluctuators (TLFs) is observed
below 1 K. Upon saturating the TLFs in the substrate-free YIG at 20 mK,
linewidths of 1.4 MHz are achievable: lower than those measured at room
temperature.",1903.02527v3
2019-04-09,Angular momentum compensation manipulation to room temperature of the ferrimagnet Ho$_{3-x}$Dy$_x$Fe$_5$O$_{12}$ detected by the Barnett effect,"We demonstrate that the angular momentum compensation temperature $T_A$, at
which the net angular momentum in the sample disappears, can be controlled in
Ho$_3$Fe$_5$O$_{12}$ by partially substituting Dy for Ho. The $T_A$ can be
detected using the Barnett effect, by which mechanical rotation magnetizes an
object due to spin-rotation coupling. We found that $T_A$ increases with the Dy
content and clarified that the $T_A$ of Ho$_{1.5}$Dy$_{1.5}$Fe$_5$O$_{12}$
coincides with room temperature. The Barnett effect enables us to explore
materials applicable to magnetic devices utilizing the angular momentum
compensation only by rotating the powder sample at room temperature.",1904.04567v1
2019-04-10,Magnetization-polarization cross-control near room temperature in hexaferrite single crystals,"Mutual control of the electricity and magnetism in terms of magnetic (H) and
electric (E) fields, the magnetoelectric (ME) effect, offers versatile low
power-consumption alternatives to current data storage, logic gate, and
spintronic devices. Despite its importance, E-field control over magnetization
(M) with significant magnitude was observed only at low temperatures. Here we
have successfully stabilized a simultaneously ferrimagnetic and ferroelectric
phase in a Y-type hexaferrite single crystal up to T=450K and demonstrated the
reversal of large non-volatile M by E field close to room temperature.
Manipulation of the magnetic domains by E field is directly visualized at room
temperature by using magnetic force microscopy. The present achievement
provides an important step towards the application of bulk ME multiferroics.",1904.05017v1
2019-08-13,Converting Faraday rotation into magnetization in europium chalcogenides,"We present a simple semiclassical model to sustain that in europium
chalcogenides (EuX), Faraday rotation (FR) in the transparency gap is
proportional to the magnetization of the sample, irrespective of the material's
magnetic phase, temperature, or applied magnetic field. The model is validated
by FR and magnetization measurements in EuSe in the temperature interval
1.7-300K, covering all EuSe magnetic phases (paramagnetic, antiferromagnetic
type I or type II, ferrimagnetic and ferromagnetic). Furthermore, by combining
the semiclassical model with the explicit electronic energy structure of EuX,
the proportionality coefficient between magnetization and FR is shown to be
dependent only on the wavelength and the band gap. Due to its simplicity, the
model has didactic value, moreover, it provides a working tool for converting
FR into magnetization in EuX. Possible extension of the model to other
intrinsic magnetic semiconductors is discussed.",1908.04444v1
2019-08-28,Critical size limits for collinear and spin spiral magnetism in CoCr$_2$O$_4$,"The multiferroic behavior of CoCr$_2$O$_4$ results from the appearance of
conical spin-spiral magnetic ordering, which induces electric polarization. The
magnetic ground state has a complex size dependent behavior, which collapses
when reaching a critical particle size. Here, the magnetic phase stability of
CoCr$_2$O$_4$ in the size range of 3.6 - 14.0 nm is presented in detail using
the combination of neutron diffraction with XYZ polarization analysis and
macroscopic magnetization measurements. We establish critical coherent domain
sizes for the formation of the spin spiral and ferrimagnetic structure and
reveal the evolution of the incommensurate spin spiral vector with particle
size. We further confirm the presence of ferroelectric polarization in the spin
spiral phase for nanocrystalline CoCr$_2$O$_4$.",1908.10582v1
2019-11-08,The delta-chain with ferro- and antiferromagnetic interactions in applied magnetic field,"We study the thermodynamics of the delta-chain with competing ferro- and
antiferromagnetic interactions in an external magnetic field which generalizes
the field-free case studied previously. This model plays an important role for
the recently synthesized compound Fe$_{10}$Gd$_{10}$ which is nearly quantum
critical. The classical version of the model is solved exactly and explicit
analytical results for the low-temperature thermodynamics are obtained. The
spin-$s$ quantum model is studied using exact diagonalization and
finite-temperature Lanzos techniques. Particular attention is focused on the
magnetization and the susceptibility. The magnetization of the classical model
in the ferromagnetic part of the phase diagram defines the universal scaling
function which is valid for the quantum model. The dependence of the
susceptibility on the spin quantum number $s$ at the critical point between the
ferro- and ferrimagnetic phases is studied and the relation to
Fe$_{10}$Gd$_{10}$ is discussed.",1911.03081v1
2019-11-13,Perpendicular Magnetic Anisotropy in Conducting NiCo2O4 Films from Spin-Lattice Coupling,"High perpendicular magnetic anisotropy (PMA), a property needed for nanoscale
spintronic applications, is rare in oxide conductors. We report the observation
of a PMA up to 0.23 MJ/m3 in modestly strained epitaxial NiCo2O4 (NCO) films
which are room-temperature ferrimagnetic conductors. Spin-lattice coupling
manifested as magnetoelastic effect was found as the origin of the PMA. The
in-plane xx-yy states of Co on tetrahedral sites play crucial role in the
magnetic anisotropy and spin-lattice coupling with an energy scale of 1
meV/f.u. The elucidation of the microscopic origin paves a way for engineering
oxide conductors for PMA using metal/oxygen hybridizations.",1911.05322v1
2019-11-27,Observation of the Magnon Polarization,"We measure the mode-resolved direction of the precessional motion of the
magnetic order, i.e., magnon polarization, via the chiral term of inelastic
polarized neutron scattering spectra. The magnon polarisation is important in
spintronics, affecting thermodynamic properties such as the magnitude and sign
of the spin Seebeck effect. The observation of both signs of magnon
polarization in Y3Fe5O12 also gives direct proof of its ferrimagnetic nature.
The experiments agree very well with atomistic simulations of the scattering
cross section.",1911.11968v1
2019-11-30,"A magnetocaloric study on the series of 3d-metal chromites ACr$_{2}$O$_{4}$ where A = Mn, Fe, Co, Ni, Cu and Zn","The 3d-metal chromites ACr$_2$O$_4$ where A is a magnetic ion, show the
paramagnetic to ferrimagnetic phase transition at T$_C$ while for non-magnetic
A-site ion, ACr$_2$O$_4$ show paramagnetic to antiferromagnetic phase
transition at T$_N$. In this report, we present the detailed study of magnetic
and the magnetocaloric effect (MCE) of the 3d-metal chromites ACr$_{2}$O$_{4}$
(where A = Mn, Fe, Co, Ni, Cu, and Zn) near T$_C$ and T$_N$. We find the
magnitude of MCE (-$\Delta$S$_M$) decreases on decreasing the magnetic moment
of A-site ion with an exception for CuCr$_{2}$O$_{4} $. Additionally, to know
more about the order and nature of phase transition, we have made a scaling
analysis of (-$\Delta$S$_{M}$) for all the chromites across the phase
transition temperatures T$_C$ and T$_N$.",1912.00116v1
2019-12-14,"Electron doping and correlation effects on crystal, electronic and magnetic structures of A$_2$NRuO$_6$ (A2 = Ba$_2$, BaLa; N = V, Cr, Fe)","Density functional methods have been used to study the crystal, electronic
and magnetic structures of new ordered double perovskites A2NRuO6 (A2 = Ba2,
BaLa; N = V, Cr, Fe). In the doped compounds, the A-site was replaced by 1:1 of
Ba and La cations, BaLaNRuO6. All compounds of A2NRuO6 crystallize in cubic
symmetry with space group Fm-3m and tilt system a0a0a0. The electronic and
magnetic calculations were performed by the full-potential linear muffin-tin
orbital method using both the generalized gradient approximation and GGA plus
on-site electron correlation effect GGA+U. In GGA, Ba2NRuO6 shows
half-metallic, semiconducting and metallic behavior for N = V, Cr, Fe,
respectively, completely change to half-metallic when A2 = BaLa. While, GGA+U
method yields clearly half-metallic in all compounds, except for Ba2FeRuO6,
shows an insulating behavior. Also, the results of magnetic structures
calculations reveal that the A2NRuO6 compounds have ferrimagnetic nature if N =
V and Cr, switch to ferromagnetic when N = Fe. The V3+, Cr3+, Fe3+ and Ru5+
ions are in high spin magnetic moments states due to the antiferromagnetic
coupling.",1912.06843v1
2019-12-23,Peculiarities of electronic transport and magnetic state in half-metallic ferromagnetic and spin gapless semiconducting Heusler alloys,"A brief survey of experimental and theoretical studies of half-metallic
ferromagnets (HMFs) and spin gapless semiconductors is given, the possible
candidates being the X$_2$YZ (X = Mn, Fe, Co; Y = Ti, V, Cr, Mn, Fe, Co, Ni; Z
= Al, Si, Ga, Ge, In, Sn, Sb) Heusler alloys. The data on the electrical
resistivity, normal and anomalous Hall Effect, and magnetic properties are
presented. It is shown that the Co$_2$FeZ alloys demonstrate properties of
conventional ferromagnets, the HMF properties being also manifested at the
variation of the Z-component. The Fe$_2$YAl and Mn$_2$YAl alloys show at the
variation of the Y-component both metallic and semiconducting electronic
characteristics, the magnetic properties, changing from the ferromagnetic to
compensated ferrimagnetic state. The HMF and spin gapless semiconductor states
are supposed to exist in these Heusler alloys systems.",1912.10771v1
2020-03-09,Ab initio description of the Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ electronic structure,"Bi-based cuprate superconductors are important materials for both fundamental
research and applications. As in other cuprates, the superconducting phase in
the Bi compounds lies close to an antiferromagnetic phase. Our density
functional theory calculations based on the
strongly-constrained-and-appropriately-normed (SCAN) exchange correlation
functional in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ reveal the persistence of
magnetic moments on the copper ions for oxygen concentrations ranging from the
pristine phase to the optimally hole-doped compound. We also find the existence
of ferrimagnetic solutions in the heavily doped compounds, which are expected
to suppress superconductivity.",2003.04034v3
2020-03-11,Excitation and relaxation dynamics of spin-waves triggered by ultrafast photo-induced demagnetization in a ferrimagnetic insulator,"Excitation and propagation dynamics of spin waves in an iron-based garnet
film under out-of-plane magnetic field were investigated by time-resolved
magneto-optical imaging. The experimental results and the following data
analysis by phase-resolved spin-wave tomography reveal the excitation of spin
waves triggered by photo-induced demagnetization (PID) along the sample depth
direction. Moreover, the fast relaxation of PID accompanied by the spin
transfer due to spin-wave emission was observed. Possible scenarios of PID in
the garnet film are discussed. Finally, we develop a model for the spin-wave
excitation triggered by PID and explain the magnetic-field dependence in the
amplitude of the observed spin waves.",2003.05159v1
2020-03-18,Pressure-induced inverse order-disorder transition in double perovskites,"Given the consensus that pressure improves cation order in most of known
materials, a discovery of pressure-induced disorder could require
reconsideration of order-disorder transition in solid state physics/chemistry
and geophysics. Double perovskites Y2CoIrO6 and Y2CoRuO6 synthesized at ambient
pressure show B-site order, while the polymorphs synthesized at 6 and 15 GPa
are partially-ordered and disordered respectively. With the decrease of
ordering degrees, the lattices are shrunken and the crystal structures alter
from monoclinic to orthorhombic symmetry. Correspondingly, long-range
ferrimagnetic order in the B-site ordered phases are gradually overwhelmed by
B-site disorder. Theoretical calculations suggest that unusual unit cell
compressions under external pressures unexpectedly stabilize the disordered
phases of Y2CoIrO6 and Y2CoRuO6.",2003.08025v3
2020-03-20,A ternary map of Ni-Mn-Ga Heusler alloys from ab initio calculations,"In the present work, the aspects of magnetic and structural properties of
Ni-Mn-Ga alloys are described in the framework of fist-principles approach and
mapped into ternary composition diagrams. The stable atomic arrangement and
magnetic alignment for compositions with cubic austenite and tetragonal
martensite structures across phase diagrams are predicted. It is shown that Ni-
and Ga-rich compositions possess the regular Heusler structure in contrast to
Mn-rich compositions with inverse Heusler structure as favorable one.
Compositions with unstable austenite structure are concentrated in the left and
right sides of diagram whereas compositions with unstable martensite structure
are located in the low-middle part of diagram. The magnetic phase diagrams
showing regions with the ferromagnetic order and the complex ferrimagnetic
order for austenitic and martensitic compositions are obtained. The results of
calculations are in a good agreement with available experimental data.",2003.09128v1
2020-03-30,Spontaneous Rotation of Ferrimagnetism Driven by Antiferromagnetic Spin Canting,"Spin-reorientation phase transitions that involve the rotation of a
crystal$'$s magnetization have been well characterized in distorted-perovskite
oxides such as the orthoferrites. In these systems spin reorientation occurs
due to competing rare-earth and transition metal anisotropies coupled via
$f$-$d$ exchange. Here, we demonstrate an alternative paradigm for spin
reorientation in distorted perovskites. We show that the
$R_2\mathrm{CuMnMn_4O_{12}}$ (R = Y or Dy) triple A-site columnar-ordered
quadruple perovskites have three ordered magnetic phases and up to two
spin-reorientation phase transitions. Unlike the spin-reorientation phenomena
in other distorted perovskites, these transitions are independent of rare-earth
magnetism, but are instead driven by an instability towards antiferromagnetic
spin canting likely originating in frustrated Heisenberg exchange interactions,
and the competition between Dzyaloshinskii-Moriya and single-ion anisotropies.",2003.13774v1
2020-05-07,Detecting quadrupole: a hidden source of magnetic anisotropy for Manganese alloys,"Mn-based alloys exhibit unique properties in the spintronics materials
possessing perpendicular magnetic anisotropy (PMA) beyond the Fe and Co-based
alloys. It is desired to figure out the quantum physics of PMA inherent to
Mn-based alloys, which have never been reported. Here, the origin of PMA in
ferrimagnetic Mn$_{3-{\delta}}$Ga ordered alloys is investigated to resolve
antiparallel-coupled Mn sites using x-ray magnetic circular and linear
dichroism (XMCD/XMLD) and a first-principles calculation. We found that the
contribution of orbital magnetic moments in PMA is small from XMCD and that the
finite quadrupole-like orbital distortion through spin-flipped electron hopping
is dominant from XMLD and theoretical calculations. These findings suggest that
the spin-flipped orbital quadrupole formations originate from the PMA in
Mn$_{3-{\delta}}$Ga and bring the paradigm shift in the researches of PMA
materials using x-ray magnetic spectroscopies.",2005.03249v1
2020-05-07,Structural and magnetic behavior of Cr$_2$Co$_{(1-x)}$Cr$_x$Al inverse Heusler alloys,"We report the structural and magnetic behavior of single phase inverse
Heusler alloys Cr$_2$Co$_{(1-x)}$Cr$_x$Al ($x = $ 0, 0.2, 0.4) using x-ray
diffraction (XRD), Raman spectroscopy, isothermal magnetization, and magnetic
susceptibility measurements. Interestingly, the Rietveld refinement of XRD data
with the space group I$\bar{4}m2$ reveal a tetragonal distortion with c/a ratio
around 1.38 in these inverse Heusler structures. The bulk compositions have
been confirmed by energy dispersive x-ray spectroscopy measurements. The active
Raman mode F$_{2g}$ is observed at 320~cm$^{-1}$, which confirms the X-type
Heusler structure as the A2 and B2 type structures are known to be not Raman
active. The area of F$_{2g}$ mode decreases with Cr concentration, which
indicate the origin of this mode due to Co vibrations. The isothermal
magnetization data confirm the magnetic moment close to zero ($\le$0.02
$\mu_B/f.u.$) at $\approx$70~kOe and negligible coercive field suggest the
fully compensated ferrimagnetic nature of these samples. The susceptibility
behavior indicates irreversibility between zero-field and field-cooled curves
and complex magnetic interactions at low temperatures.",2005.03528v1
2020-05-13,Interplay between magnetism and charge instabilities in layered NbSe$_{2}$,"Using ab initio methods based on density functional theory, the electronic
and magnetic structure of layered hexagonal NbSe$_{2}$ is studied. In the case
of single-layer NbSe$_{2}$ it is found that, for all the functionals
considered, the magnetic solution is lower in energy than the non-magnetic
solution. The magnetic ground-state is ferrimagnetic with a magnetic moment of
1.09 $\mu_{B}$ at the Nb atoms and a magnetic moment of 0.05 $\mu_{B}$, in the
opposite direction, at the Se atoms. Our calculations show that single-layer
NbSe$_{2}$ does not display a charge density wave instability unless a graphene
layer is considered as a substrate. Then, two kinds of 3$\times$3 charge
density waves are found, which are observed in our STM experiments. This
suggest that the driving force of charge instabilities in NbSe$_{2}$ differ in
bulk and in the single-layer limit. Our work sets magnetism into play in this
highly-correlated 2D material, which is crucial to understand the formation
mechanisms of 2D superconductivity and charge density wave order.",2005.06210v1
2020-05-16,All-optical switching of magnetic domains in Co/Gd heterostructures with Dzyaloshinskii-Moriya Interaction,"Given the development of hybrid spintronic-photonic devices and chiral
magnetic structures, a combined interest in all-optical switching (AOS) of
magnetization and current-induced domain wall motion in synthetic ferrimagnetic
structures with strong Dzyaloshinskii-Moriya Interaction (DMI) is emerging. In
this study, we report a study on single-pulse all-optical toggle switching and
asymmetric bubble expansion in specially engineered Co/Gd-based multilayer
structures. In the absence of any external magnetic fields, we look into the
AOS properties and the potential role of the DMI on the AOS process as well as
the stability of optically written micro-magnetic domains. Particularly,
interesting dynamics are observed in moon-shaped structures written by two
successive laser pulses. The stability of domains resulting from an interplay
of the dipolar interaction and domain-wall energy are compared to simple
analytical models and micromagnetic simulations.",2005.07969v2
2020-05-19,Dissipation-based Quantum Sensing of Magnons with a Superconducting Qubit,"Hybrid quantum devices expand the tools and techniques available for quantum
sensing in various fields. Here, we experimentally demonstrate quantum sensing
of the steady-state magnon population in a magnetostatic mode of a
ferrimagnetic crystal. Dispersively coupling the magnetostatic mode to a
superconducting qubit allows the detection of magnons using Ramsey
interferometry with a sensitivity on the order of $10^{-3}$
$\text{magnons}/\sqrt{\text{Hz}}$. The protocol is based on dissipation as
dephasing via fluctuations in the magnetostatic mode reduces the qubit
coherence proportionally to the number of magnons.",2005.09250v1
2020-06-26,Interfacing topological insulators and ferrimagnets: Bi$_2$Te$_3$ and Fe$_3$O$_4$ heterostructures grown by molecular beam epitaxy,"Relying on the magnetism induced by the proximity effect in heterostructures
of topological insulators and magnetic insulators is one of the promising
routes to achieve the quantum anomalous Hall effect. Here we investigate
heterostructures of Bi$_2$Te$_3$ and Fe$_3$O$_4$. By growing two different
types of heterostructures by molecular beam epitaxy, Fe$_3$O$_4$ on
Bi$_2$Te$_3$ and Bi$_2$Te$_3$ on Fe$_3$O$_4$, we explore differences in
chemical stability, crystalline quality, electronic structure, and transport
properties. We find the heterostructure Bi$_2$Te$_3$ on Fe$_3$O$_4$ to be a
more viable approach, with transport signatures in agreement with a gap opening
in the topological surface states.",2006.14914v1
2020-08-06,Boris Computational Spintronics -- High Performance Multi-Mesh Magnetic and Spin Transport Modelling Software,"This work discusses the design and testing of a new computational spintronics
research software. Boris is a comprehensive multi-physics open-source software,
combining micromagnetics modelling capabilities with drift-diffusion spin
transport modelling and heat flow solver in multi-material structures. A
multi-mesh paradigm is employed, allowing modelling of complex multi-layered
structures with independent discretization and arbitrary relative positioning
between different computational meshes. Implemented micromagnetics models
include not only ferromagnetic materials modelling, but also two-sublattice
models, allowing simulations of antiferromagnetic and ferrimagnetic materials,
fully integrated in the multi-mesh and multi-material design approach. High
computational performance is an important design consideration in Boris, and
all computational routines can be executed on GPUs, in addition to CPUs. In
particular a modified 3D convolution algorithm is used to compute the
demagnetizing field on the GPU, termed pipelined convolution, and benchmark
comparisons with existing GPU-accelerated software Mumax3 have shown
performance improvements up to twice faster.",2008.02478v1
2020-08-12,Determination of Niobium Cavity Magnetic Field Screening via a Dispersively Hybridized Magnonic Sensor,"A method for determining the internal DC magnetic field inside a
superconducting cavity is presented. The method relies on the relationship
between magnetic field and frequency of the Kittel mode of a ferrimagnetic
sphere, hybridised in the dispersive regime of the superconducting cavity.
Results were used to experimentally determine the level of screening a
superconducting Nb cavity provides as it changes from perfect diamagnetism to
no screening. Two cavity geometries were tested, a cylinder and single post
re-entrant cavity. Both demonstrated a consistent value of field that enters
the cavity, expected to be the superheating critical field. Hysteresis in the
screened field during ramp up and ramp down of the external magnetic field due
to trapped vortices was also observed. Some abnormal behaviour was observed in
the cylindrical cavity in the form of plateaus in the internal field above the
first critical field, and we discuss the potential origin of this behaviour.
The measurement approach would be a useful diagnostic for axion dark matter
searches, which plan on using superconducting materials but need to know
precisely the internal magnetic field.",2008.05073v2
2020-08-30,Element-specific field-induced spin reorientation and an unusual tetracritical point in MnCr2S4,"The ferrimagnetic spinel MnCr2S4 shows a variety of magnetic-field-induced
phase transitions owing to bond frustration and strong spin-lattice coupling.
However, the site-resolved magnetic properties at the respective field-induced
phases in high magnetic fields remain elusive. Our soft x-ray magnetic circular
dichroism studies up to 40 T directly evidence element-selective
magnetic-moment reorientations in the field-induced phases. The complex
magnetic structures are further supported by entropy changes extracted from
magnetocaloric-effect measurements. Moreover, thermodynamic experiments reveal
an unusual tetracritical point in the H-T phase diagram of MnCr2S4 due to
strong spin-lattice coupling.",2008.13285v3
2020-08-31,Modulation of spin conversion in a 1.5 nm-thick Pd film by ionic gating,"Gate-induced modulation of the spin-orbit interaction (SOI) in a 1.5 nm-thick
Pd thin film grown on a ferrimagnetic insulator was investigated. Efficient
charge accumulation by ionic gating enables a substantial upshift in the Fermi
level of the Pd film, which was corroborated by suppression of the resistivity
in the Pd. Electromotive forces arising from the inverse spin Hall effect in Pd
under spin pumping were substantially modulated by the gating, in consequence
of the modulation of the spin Hall conductivity of Pd as in an ultrathin Pt
film. The same experiment using a thin Cu film, for which the band structure is
largely different from Pd and Pt and its SOI is quite small, provides further
results supporting our claim. The results obtained help in developing a
holistic understanding of the gate-tunable SOI in solids and confirm a previous
explanation of the significant modulation of the spin Hall conductivity in an
ultrathin Pt film by gating.",2008.13438v1
2020-09-11,Electron-Phonon Interactions in Flat Band Systems,"Existing Quantum Monte Carlo studies have investigated the properties of
fermions on a Lieb (CuO$_2$) lattice interacting with an on-site, or
near-neighbor electron-electron coupling. Attention has focused on the
interplay of such interactions with the macroscopic degeneracy of local zero
energy modes, from which Bloch states can be formed to produce a flat band in
which energy is independent of momentum. The resulting high density of states,
in combination with the Stoner criterion, suggests that there should be
pronounced instabilities to ordered phases. Indeed, a theorem by Lieb
rigorously establishes the existence of ferrimagnetic order. Here we study the
charge density wave phases induced by electron-phonon coupling on the Lieb
lattice, as opposed to previous work on electron-electron interactions. Our key
result is the demonstration of charge density wave (CDW) phases at one-third
and two-thirds fillings, characterized by long-range density density
correlations between doubly occupied sites on the minority or majority
sublattice, and an accompanying gap. We also compute the transition temperature
to the ordered phase as a function of the electron-phonon coupling.",2009.05595v3
2020-09-24,Pressure-Temperature Phase Diagram of $α$-Mn,"Electrical resistivity and ac-susceptibility measurements under high pressure
were carried out in high-quality single crystals of $\alpha$-Mn. The
pressure-temperature phase diagram consists of an antiferromagnetic ordered
phase (0<$P$<1.4 GPa, $T<T_{\rm N}$), a pressure-induced ordered phase
(1.4<$P$<4.2-4.4 GPa, $T<T_{\rm A}$), and a paramagnetic phase. A significant
increase was observed in the temperature dependence of ac-susceptibility at
$T_{\rm A}$, indicating that the pressure-induced ordered phase has a
spontaneous magnetic moment. Ferrimagnetic order and parasitic ferromagnetism
are proposed as candidates for a possible magnetic structure. At the critical
pressure, where the pressure-induced ordered phase disappears, the temperature
dependence of the resistivity below 10 K is proportional to $T^{5/3}$. This
non-Fermi liquid behavior suggests the presence of pronounced magnetic
fluctuation.",2009.11488v1
2020-09-25,Experimental search for an exotic spin-spin-velocity-dependent interaction using an optically polarized vapor and a rare-earth iron garnet,"We report an experimental search for an exotic spin-spin-velocity-dependent
interaction between polarized electrons of Rb atoms and polarized electrons of
a solid-state mass, violating both the time-reversal and parity symmetries.
This search targets a minute effective magnetic field induced by the
interaction. A spin-exchange relaxation-free (SERF) magnetometer based on an
optically polarized Rb vapor is the key element for both a source of polarized
electrons and a high-sensitivity detector. A dysprosium iron garnet (DyIG)
serves as the polarized mass, with an extremely small magnetization at the
critical temperature around 240 K and a high spin density. To reduce the
magnetization, one of major systematic effects, a home-built cooling system
controls the mass temperature. To our knowledge, this is the first search for
an exotic spin-dependent interaction using the compensated ferrimagnet DyIG as
a polarized mass. The experiment set the most stringent limit on the
electron-electron coupling strength in the centimeter interaction range, in
particular $g_V^e g_V^e <10^{4}$ at $\lambda=2$ cm.",2009.12292v2
2020-09-30,Electronic structure and finite temperature magnetism of yttrium iron garnet,"Yttrium iron garnet is a complex ferrimagnetic insulator with 20 magnon modes
which is used extensively in fundamental experimental studies of magnetisation
dynamics. As a transition metal oxide with moderate gap (2.8 eV), yttrium iron
garnet requires a careful treatment of electronic correlation. We have applied
quasiparticle self-consistent GW to provide a fully ab initio description of
the electronic structure and resulting magnetic properties, including the
parameterisation of a Heisenberg model for magnetic exchange interactions.
Subsequent spin dynamical modelling with quantum statistics extends our
description to the magnon spectrum and thermodynamic properties such as the
Curie temperature, finding favourable agreement with experimental measurements.
This work provides a snapshot of the state-of-the art in modelling of complex
magnetic insulators.",2009.14601v1
2020-10-14,"Ab-initio study of electronic and magnetic properties of Mn$_2$RuZ/MgO (001) heterojunctions (Z= Al, Ga, Si, Ge)","Using first-principles calculations, we studied Mn$_2$RuZ (Z=Al, Ga, Si, Ge)
and their heterojunctions with MgO along (001) direction. All these alloys
possess Hg$_2$CuTi-type inverse Heusler alloy structure and ferrimagnetic
ground state. Our study reveals the half-metallic electronic structure with
highly spin-polarized $\Delta_1$ band, which is robust against atomic disorder.
Next we studied the electronic structure of Mn$_2$RuAl/MgO and Mn$_2$RuGe/MgO
heterojunctions. We found that the MnAl- or MnGe-terminated interface is
energetically more favorable compared to the MnRu-terminated interface.
Interfacial states appear at the Fermi level in the minority-spin gap for the
Mn$_2$RuGe/MgO junction. We discuss the origin of these interfacial states in
terms of local environment around each constituent atom. On the other hand, in
the Mn$_2$RuAl/MgO junction, high spin polarization of bulk Mn$_2$RuAl is
preserved independent of its termination.",2010.06761v1
2020-10-20,Topological correspondence between magnetic space group representations,"The past years have seen rapid progress in the classification of topological
materials. These diagnostical methods are increasingly getting explored in the
pertinent context of magnetic structures. We report on a general class of
electronic configurations within a set of anti-ferromagnetic-compatible space
groups that are necessarily topological. Interestingly, we find a systematic
correspondence between these anti-ferromagnetic phases to necessarily
nontrivial topological ferro/ferrimagnetic counterparts that are readily
obtained through physically motivated perturbations. Addressing the exhaustive
list of magnetic space groups in which this mechanism occurs, we also verify
its presence on planes in 3D systems that were deemed trivial in existing
classification schemes. This leads to the formulation of the concept of
subdimensional topologies, featuring non-triviality within part of the system
that coexists with stable Weyl points away from these planes, thereby
uncovering novel topological materials in the full 3D sense that have readily
observable features in their bulk and surface spectrum.",2010.10536v3
2020-10-28,Recent progress in antiferromagnetic dynamics,"Spintronics, since its inception, has mainly focused on ferromagnetic
materials for manipulating the spin degree of freedom in addition to the charge
degree of freedom, whereas much less attention has been paid to
antiferromagnetic materials. Thanks to the advances of micro-nano-fabrication
techniques and the electrical control of the N\'eel order parameter,
antiferromagnetic spintronics is booming as a result of abundant room
temperature materials, robustness against external fields and dipolar coupling,
and rapid dynamics in the terahertz regime. For the purpose of applications of
antiferromagnets, it is essential to have a comprehensive understanding of the
antiferromagnetic dynamics at the microscopic level. Here, we first review the
general form of equations that govern both antiferromagnetic and ferrimagnetic
dynamics. This general form unifies the previous theories in the literature. We
also provide a survey for the recent progress related to antiferromagnetic
dynamics, including the motion of antiferromagnetic domain walls and skyrmions,
the spin pumping and quantum antiferromagnetic spintronics. In particular, open
problems in several topics are outlined. Furthermore, we discuss the
development of antiferromagnetic quantum magnonics and its potential
integration with modern information science and technology.",2010.14940v1
2020-11-25,Magnetism and Piezoelectricity in Stable Transition Metal Silicate Monolayers,"Two-dimensional van der Waals (2D vdW) materials that display ferromagnetism
and piezoelectricity have received increased attention. Despite numerous 2D
materials have so far been reported as ferromagnetic, developing an air stable
and transferable vdW material that is multiferroic has been challenging. To
address this problem, we report our work on layered transition metal silicates
that are derivatives of kaolinites and lizardites with transition metal
substituting on Al$^{3+}$ and Mg$^{2+}$ sites using ab-initio calculations.
Using Density Functional Theory (DFT), we show that these compounds are stable
under varying O$_2$ partial pressure and can be synthesized using a surface
assisted method. We show that these materials have finite out-of-plane
piezoelectric response thanks to the lack of inversion symmetry and also they
can be tailored to be ferrimagnetic with a non-zero net moment.",2011.12938v4
2020-11-30,Domain wall patterning and giant response functions in ferrimagnetic spinels,"The manipulation of mesoscale domain wall phenomena has emerged as a powerful
strategy for designing ferroelectric responses in functional devices, but its
full potential has not yet been realized in the field of magnetism. We show
that mechanically strained samples of Mn$_3$O$_4$ and MnV$_2$O$_4$ exhibit a
stripe-like patterning of the bulk magnetization below known magnetostructural
transitions, similar to the structural domains reported in ferroelectric
materials. Building off our previous magnetic force microscopy data, we use
small angle neutron scattering to show that these patterns extend to the bulk,
and demonstrate an ability to manipulate the domain walls via applied magnetic
field and mechanical stress. We then connect these domains back to the
anomalously large magnetoelastic and magnetodielectric response functions
reported in these materials, directly correlating local and macroscopic
measurements on the same crystals.",2011.14970v1
2021-02-12,Manipulation of magnetic domain wall by ferroelectric switching: Dynamic magnetoelectricity at the nanoscale,"Controlling magnetism using voltage is highly desired for applications, but
remains challenging due to fundamental contradiction between polarity and
magnetism. Here we propose a mechanism to manipulate magnetic domain walls in
ferrimagnetic or ferromagnetic multiferroics using electric field. Different
from those studies based on static domain-level couplings, here the
magnetoelectric coupling relies on the collaborative spin dynamics around
domain walls. Accompanying the reversal of spin chirality driven by
polarization switching, a ""rolling-downhill""-like motion of domain wall is
achieved at the nanoscale, which tunes the magnetization locally. Our mechanism
opens an alternative route to pursuit practical and fast converse
magnetoelectric functions via spin dynamics.",2102.06471v2
2021-03-12,Double accumulation and anisotropic transport of magneto-elastic bosons in yttrium iron garnet films,"Interaction between quasiparticles of a different nature, such as magnons and
phonons in a magnetic medium, leads to the mixing of their properties and the
formation of hybrid states in the areas of intersection of individual spectral
branches. We recently reported the discovery of a new phenomenon mediated by
the magnon-phonon interaction: the spontaneous bottleneck accumulation of
magneto-elastic bosons under electromagnetic pumping of pure magnons into a
ferrimagnetic yttrium iron garnet film. Here, by studying the transport
properties of the accumulated magneto-elastic bosons, we reveal that such
accumulation occurs in two frequency-distant groups of quasiparticles:
quasi-phonons and quasi-magnons. They propagate with different speeds in
different directions relative to the magnetization field. The theoretical model
we propose qualitatively describes the double accumulation effect, and the
analysis of the two-dimensional spectrum of quasiparticles in the hybridization
region allows us to determine the wavevectors and frequencies of each of the
groups.",2103.07338v1
2021-03-13,Microscopic Calculation of Spin Torques in Textured Antiferromagnets,"A microscopic calculation is presented for the spin-transfer torques (STT)
and damping torques in metallic antiferromagnets (AF). It is found that the
sign of the STT is opposite to that in ferromagnets because of the AF transport
character, and the current-to-STT conversion factor is enhanced near the AF gap
edge. The dissipative torque parameter $\beta_n$ and the damping parameter
$\alpha_n$ for the N\'eel vector arise from spin relaxation of electrons.
Physical consequences are demonstrated for the AF domain wall motion using
collective coordinates, and some similarities to the ferromagnetic case are
pointed out such as intrinsic pinning and the specialty of $\alpha_n =
\beta_n$. A recent experiment on a ferrimagnetic GdFeCo near its
angular-momentum compensation temperature is discussed.",2103.07634v1
2021-03-19,Remote magnon entanglement between two massive ferrimagnetic spheres via cavity optomagnonics,"Recent studies show that hybrid quantum systems based on magnonics provide a
new and promising platform for generating macroscopic quantum states involving
a large number of spins. Here we show how to entangle two magnon modes in two
massive yttrium-iron-garnet (YIG) spheres using cavity optomagnonics, where
magnons couple to high-quality optical whispering gallery modes supported by
the YIG sphere. The spheres can be as large as 1 mm in diameter and each sphere
contains more than $10^{18}$ spins. The proposal is based on the asymmetry of
the Stokes and anti-Stokes sidebands generated by the magnon-induced Brillouin
light scattering in cavity optomagnonics. This allows one to utilize the Stokes
and anti-Stokes scattering process, respectively, for generating and verifying
the entanglement. Our work indicates that cavity optomagnonics could be a
promising system for preparing macroscopic quantum states.",2103.10595v2
2021-03-30,"Anomalous Hall effect in distorted kagome magnets (Nd, Sm)Mn$_6$Sn$_6$","We report magnetic and electrical properties for single crystals of
NdMn$_6$Sn$_6$ and SmMn$_6$Sn$_6$. They crystallize into a structure which has
distorted, Mn-based kagome lattices, compared to the pristine kagome lattices
in heavy-rare-earth-bearing RMn$_6$Sn$_6$ compounds. They are hightemperature
ferromagnets of which the R moment is parallel with the Mn moment. We observed
a large intrinsic anomalous Hall effect (AHE) that is comparable to the
ferrimagnetic, heavy-R siblings in a wide range of temperature. We conclude
that their intrinsic AHE is stemming from the Mn-based kagome lattice, just as
in the heavy RMn$_6$Sn$_6$.",2103.16473v2
2021-04-14,Persisting correlation between electrical transport and magnetic dynamics in M-type hexaferrites,"In this work we present frequency-dependent magnetic susceptibility and dc
electric transport properties of three different compositions of hexaferrite
Ba$_{1-x}$Pb$_{x}$Fe$_{12-y}$Al$_{y}$O$_{19}$. We find a correlation between
activation energies of dc electric transport and ac magnetic susceptibility
which persists in the whole researched range of aluminium substitution $x=0$ to
$3.3$. This result is discussed in the context of charged magnetic domain
walls, the pinning of which is determined by charge carriers activated over the
transport gap. Our work points toward a general relaxational mechanism in
ferrimagnetic semiconductors which directly affects dynamic magnetic properties
via electric transport.",2104.06964v2
2021-04-26,Cavity magnomechanical storage and retrieval of quantum states,"We show how a quantum state in a microwave cavity mode can be transferred to
and stored in a phononic mode via an intermediate magnon mode in a
magnomechanical system. For this we consider a ferrimagnetic yttrium iron
garnet (YIG) sphere inserted in a microwave cavity, where the microwave and
magnon modes are coupled via a magnetic-dipole interaction and the magnon and
phonon modes in the YIG sphere are coupled via magnetostrictive forces. By
modulating the cavity and magnon detunings and the driving of the magnon mode
in time, a Stimulated Raman Adiabatic Passage (STIRAP)-like coherent transfer
becomes possible between the cavity mode and the phonon mode. The phononic mode
can be used to store the photonic quantum state for long periods as it
possesses lower damping than the photonic and magnon modes. Thus our proposed
scheme offers a possibility of using magnomechanical systems as quantum memory
for photonic quantum information.",2104.12323v1
2021-04-27,Stability of Mn2RuxGa-based Multilayer Stacks,"Perpendicular heterostructures based on a ferrimagnetic Mn2RuxGa (MRG) layer
and a ferromagnetic Co/Pt multilayer were examined to understand the effects of
different spacer layers (V, Mo, Hf, HfOx and TiN) on the interfaces with the
magnetic electrodes, after annealing at 350 C. Loss of perpendicular anisotropy
in MRG is strongly correlated with a reduction in the substrate-induced
tetragonality due to relaxation of the crystal structure. In the absence of
diffusion, strain and chemical ordering within MRG are correlated. The limited
solubility of both Hf and Mo in MRG is a source of additional valence
electrons, which results in an increase in compensation temperature Tcomp. This
also stabilises perpendicular anisotropy, compensating for changes in strain
and defect density. The reduction in squareness of the MRG hysteresis loop
measured by anomalous Hall effect is <10 %, making it useful in active devices.
Furthermore, a CoPt3 phase with (2 2 0) texture in the perpendicular Co/Pt free
layer promoted by a Mo spacer layer is the only one that retains its
perpendicular anisotropy on annealing.",2104.13319v2
2021-04-28,Polarisation-dependent single-pulse ultrafast optical switching of an elementary ferromagnet,"The ultimate control of magnetic states of matter at femtosecond (or even
faster) timescales defines one of the most pursued paradigm shifts for future
information technology. In this context, ultrafast laser pulses developed into
extremely valuable stimuli for the all-optical magnetisation reversal in
ferrimagnetic and ferromagnetic alloys and multilayers, while this remains
elusive in elementary ferromagnets. Here we demonstrate that a single laser
pulse with sub-picosecond duration can lead to the reversal of the
magnetisation of bulk nickel, in tandem with the expected demagnetisation. As
revealed by realistic time-dependent electronic structure simulations, the
central mechanism is ultrafast light-induced torques acting on the
magnetisation, which are only effective if the laser pulse is circularly
polarised on a plane that contains the initial orientation of the
magnetisation. We map the laser pulse parameter space enabling the
magnetisation switching and unveil rich intra-atomic orbital-dependent
magnetisation dynamics featuring transient inter-orbital non-collinear states.
Our findings open further perspectives for the efficient implementation of
optically-based spintronic devices.",2104.13850v1
2021-05-02,Unconventional anomalous Hall effect from magnetization parallel to the electric field,"In the anomalous Hall effect (AHE), the magnetization, electric field and the
Hall current are presumed to be mutually vertical to each other. In this work,
we propose an unconventional AHE where the magnetization, the electric field
and Hall current stay inside the same plane. Such an AHE is odd under
time-reversal and exists even when the magnetization is parallel to the
electric field or Hall current, different from the planar Hall effect which is
even under time-reversal. Here, we term it parallel anomalous Hall effect
(PAHE). We reveal that the PAHE exists when all the point group rotational and
reflection symmetries are broken where the Berry curvature field is not
necessarily parallel to the magnetization axis. We further demonstrate the PAHE
in a ferrimagnetic Weyl semimetal FeCr$_2$Te$_4$.",2105.00476v2
2021-05-18,Parity-symmetry-breaking quantum phase transition via parametric drive in a cavity magnonic system,"We study the parity-symmetry-breaking quantum phase transition (QPT) in a
cavity magnonic system driven by a parametric field, where the magnons in a
ferrimagnetic yttrium-iron-garnet sphere strongly couple to a microwave cavity.
With appropriate parameters, this cavity magnonic system can exhibit a rich
phase diagram, including the parity-symmetric phase, parity-symmetry-broken
phase, and bistable phase. When increasing the drive strength beyond a critical
threshold, the cavity magnonic system undergoes either a first- or second-order
nonequilibrium QPT from the parity-symmetric phase with microscopic excitations
to the parity-symmetry-broken phase with macroscopic excitations, depending on
the parameters of the system. Our work provides an alternate way to engineer
the QPT in a hybrid quantum system containing the spin ensemble in a ferri- or
ferromagnetic material with strong exchange interactions.",2105.08371v3
2021-06-03,Two-Dimensional Bipolar Magnetic Semiconductor with High Curie Temperature and Electrically Controllable Spin Polarization Realized in Exfoliated Cr(pyrazine)$_2$ Monolayer,"Exploring two-dimensional (2D) magnetic semiconductors with room temperature
magnetic ordering and electrically controllable spin polarization is a highly
desirable but challenging task for nanospintronics. Here, through first
principles calculations, we propose to realize such a material by exfoliating
the recently synthesized organometallic layered crystal
Li$_{0.7}$[Cr(pyz)$_2$]Cl$_{0.7}$0.25$\cdot$(THF) (pyz = pyrazine, THF =
tetrahydrofuran) [Science 370, 587 (2020)]. The feasibility of exfoliation is
confirmed by the rather low exfoliation energy of 0.27 J/m$^2$, even smaller
than that of graphite. In exfoliated Cr(pyz)$_2$ monolayer, each pyrazine ring
grabs one electron from the Cr atom to become a radical anion, then a strong
$d$-$p$ direct exchange magnetic interaction emerges between Cr cations and
pyrazine radicals, resulting in room temperature ferrimagnetism with a Curie
temperature of 342 K. Moreover, Cr(pyz)$_2$ monolayer is revealed to be an
intrinsic bipolar magnetic semiconductor where electrical doping can induce
half-metallic conduction with controllable spin-polarization direction.",2106.01582v1
2021-06-07,Voltage-control of damping constant in magnetic-insulator/topological-insulator bilayers,"The magnetic damping constant is a critical parameter for magnetization
dynamics and the efficiency of memory devices and magnon transport. Therefore,
its manipulation by electric fields is crucial in spintronics. Here, we
theoretically demonstrate the voltage-control of magnetic damping in ferro- and
ferrimagnetic-insulator (FI)/topological-insulator (TI) bilayers. Assuming a
capacitor-like setup, we formulate an effective dissipation torque induced by
spin-charge pumping at the FI/TI interface as a function of an applied voltage.
By using realistic material parameters, we find that the effective damping for
a FI with 10nm thickness can be tuned by one order of magnitude under the
voltage with 0.25V. Also, we provide perspectives on the voltage-induced
modulation of the magnon spin transport on proximity-coupled FIs.",2106.03332v1
2021-07-01,Design Rules for DMI-Stabilised Skyrmions,"Magnetic skyrmions are topological objects, which have recently been observed
in thin films at room temperature. Sub 100-nm sizes and spin polarised current
manipulation make them candidates for high density information storage and
processing. Besides material thickness, skyrmion stability involves many
contributions: ferromagnetic exchange, magnetic anisotropy,
Dzyaloshinskii-Moryia exchange interaction (DMI) and demagnetising energy.
Multidimensional phase diagrams have been reported in the litterature. In this
work we propose a simple two-parameter model, exact for thin films in the
negligible magnetisation limit, e.g. ferrimagnets close to compensation and
synthetic artificial antiferromagnets. It allows to define design rules to
stabilize small diameter skyrmions at room temperature with explicit estimates
of their nucleation and collapse energies. Comparisons to micromagnetic
calculations allow to assess the model quality for non-zero magnetisation and
show good agreement.",2107.00767v1
2021-07-06,Static and dynamic magnetic properties of K3CrO4,"We report on the magnetic properties of geometrically frustrated K3CrO4, in
which Cr5+ cations are arranged on a distorted pyrochlore lattice. The crystal
structure, static and dynamic magnetic properties of the compound are
investigated in detail. A combination of DC and AC magnetic susceptibility
measurements together with thermoremanent magnetization decay measurements
reveal several magnetic transitions: the onset of glassy canted
antiferromagnetic order occurs at 36 K, followed by the appearance of
ferromagnetic/ferrimagnetic cluster glass behavior below the freezing
temperature of 20 K. Further field-induced, temperature-dependent transitions
are observed in the range 3-10 K. The frequency dependence of the freezing
temperature for the cluster glass state is analyzed on the basis of dynamic
scaling laws including the critical slowing down formula and the Vogel-Fulcher
law.",2107.02878v1
2021-07-11,Magnetic instabilities in quasi-one-dimensional Cr-based material,"The magnetic response of a K2Cr3As3 sample has been studied by means of dc
magnetization measurements as a function of magnetic field (H) at different
temperatures ranging from 5 K up to 300 K. Looking at the magnetic hysteresis
loops m(H), a diamagnetic behavior of the sample has been inferred at
temperatures higher than 60 K, whereas at lower temperatures the sample shows a
hysteresis loop compatible with the presence of ferrimagnetism. Moreover,
several spike-like magnetization jumps, both positive and negative, have been
observed at certain fields in the range -1000 Oe < H < 1000 Oe, regardless of
the temperature considered. The field position of the magnetization jumps has
been studied at different temperatures, and their distribution can be described
by a Lorentzian curve.",2107.05032v1
2021-07-14,Tunable quantum anomalous Hall octet driven by orbital magnetism in bilayer graphene,"The quantum anomalous Hall (QAH) effect - a macroscopic manifestation of
chiral band topology at zero magnetic field - has only been experimentally
realized by magnetic doping of topological insulators (1 - 3) and delicate
design of Moire heterostructures (4 - 8). However, the seemingly simple bilayer
graphene without magnetic doping or Moire engineering has long been predicted
to host competing ordered states with QAH effects (9 - 11). Here, we explore
states in bilayer graphene with conductance of 2 e2/h that not only survive
down to anomalously small magnetic fields and up to temperatures of 5 K, but
also exhibit magnetic hysteresis. Together, the experimental signatures provide
compelling evidence for orbital magnetism driven QAH behavior with a Chern
number tunable via electric and magnetic fields as well as carrier sign. The
observed octet of QAH phases is distinct from previous observations due to its
peculiar ferrimagnetic and ferrielectric order that is characterized by
quantized anomalous charge, spin, valley, and spin-valley Hall behavior.",2107.06915v1
2021-07-20,Emerging mechanisms of magnetocaloric effect in phase-separated metals,"We present a study of the magnetocaloric effect in metallic systems
exhibiting first-order magnetic transitions and focus on consequences of
magnetic phase separation. We account for ferrimagnetic, ferromagnetic, and
Neel antiferromagnetic order. Based on the archetypal Hubbard model being
treated within the mean-field approximation, we provide and explore its
implications on the field-induced entropy change in metallic system with phase
separation. Chosen framework allows us to properly analyze phase volumes'
dependence on parameters of phase-separated (PS) system. Moreover, an account
for phase separation boundaries as functions of magnetic field provides a
natural splitting of the PS region, where each subregion corresponds to a
different temperature dependence of entropy change: moving from one subregion
to the other produces a kink, followed by a strong linear growth of entropy
change. We encounter a second-order magnetic transition from paramagnetic to
antiferromagnetic phase in PS region that occurs for particular parameter
values. Despite the fact that both phases have zero total magnetization, the
transition has a strong impact on entropy change.",2107.09709v1
2021-07-23,Reduced magnetocrystalline anisotropy of CoFe$_2$O$_4$ thin films studied by angle-dependent x-ray magnetic circular dichroism,"Spinel-type CoFe$_2$O$_4$ is a ferrimagnetic insulator with the N\'eel
temperature exceeding 790 K, and shows a strong cubic magnetocrystalline
anisotropy (MCA) in bulk materials. However, when a CoFe$_2$O$_4$ film is grown
on other materials, its magnetic properties are degraded so that so-called
magnetically dead layers are expected to be formed in the interfacial region.
We investigate how the magnetic anisotropy of CoFe$_2$O$_4$ is modified at the
interface of CoFe$_2$O$_4$/Al$_2$O$_3$ bilayers grown on Si(111) using x-ray
magnetic circular dichroism (XMCD). We find that the thinner CoFe$_2$O$_4$
films have significantly smaller MCA values than bulk materials. The reduction
of MCA is explained by the reduced number of Co$^{2+}$ ions at the $O_h$ site
reported by a previous study [Y. K. Wakabayashi $\textit{et al.}$, Phys. Rev. B
$\textbf{96}$, 104410 (2017)].",2107.11204v1
2021-08-03,Anomalous thermodynamics in a mixed spin-1/2 and spin-1 hexagonal nanowire system,"The mixed spin-1/2 Ising model and spin-1 Blume-Capel model in an hexagonal
nanowire structure under the presence of crystal field is considered. The free
energy is obtained through the transfer matrix technique, which is solved
numerically. Our main result lies in the presence of pseudo-transition in low
temperature region near the ferrimagnetic/ferromagnetic boundary, due to the
influence of a crystal field. The evidence of a pseudo-transition is observed
in several quantities. Free energy first derivative quantities like entropy and
internal energy show an abrupt but continuous jump, whereas quantities
associated with second derivatives of the free energy like the specific heat
exhibit a strong sharp peak, quite similar to a second order phase transition.
We also investigate magnetization patterns and do not find evidence of
spontaneous magnetization. Nevertheless, assuming a small magnetic field, we
can induce a magnetization which resembles a spontaneous magnetization at a
pseudo-critical temperature.",2108.01729v1
2021-08-26,Crystalline Field Effects on Magnetic and Thermodynamic properties of a Ferrimagnetic Centered Rectangular Structure,"The magnetic properties and phase diagrams of the mixed spin Ising model,
with spins S=1 and {\sigma}=1/2 on a centered rectangular structure, have been
investigated using Monte Carlo simulations based on the Metropolis algorithm.
Every spin at one lattice site has four nearest-neighbor spins of the same type
and four of the other type. We have assumed ferromagnetic interaction between
the same spins type, antiferromagnetic for different spin types. An additional
single-site crystal field term on the S=1 site was considered. We have shown
that the crystal field enhances the existence of the compensation behavior of
the system. In addition, the effects of the crystal field and exchange coupling
on the magnetic properties and phase diagrams of the system have been studied.
Finally, the magnetic hysteresis cycles of the system for several values of the
crystal field have been found.",2108.11706v1
2021-09-03,Magnetization Plateaus of a Double Fullerene Core/Shell Like-Nanostructure in an External Magnetic Field: Monte Carlo Study,"This paper concerns the investigation of the critical (HC) and the saturation
(HS) magnetic fields behavior of the studied system as a function of different
physical parameters. The Monte Carlo method has been used to study the magnetic
properties of a ferrimagnetic behavior of a double fullerene X60 core/shell
like-nanostructure, where the symbol X can be assigned to any magnetic atom.
Based on the Ising model, we focus our study on a system formed by a double
sphere core/shell. The two spheres are containing the spins: $\sigma=\pm 1/2$
in the core are surrounded by the spin $S=\pm 1, 0$ in the shell. Many types of
magnetization curves have been found, depending on the competitions among the
exchange couplings, the crystal fields and the temperature.",2109.01453v1
2021-09-03,"Magnetic Properties of the Heusler Ru$_2$Mn$_X$ ($X$ = Nb, Ta or V) Compounds: Monte Carlo Simulations","In this paper, we have focused on a comparison of the different magnetic
properties of the three nano-Heusler Ru$_2$Mn$_X$ (X = Nb, Ta or V) compounds
using the Blume-Capel Ising model. The Heusler structures are composed by
different mixed spins. In fact, the Ru and Mn atoms are modeled by spin-5/2 and
spin-1/2, respectively. While, the X atoms ($X$ = Nb, Ta and V) are represented
by the spin-7/2, spin-3/2 and spin-5/2, respectively. This study is carried out
by using the Monte Carlo simulations under the Metropolis algorithm. The
magnetic behaviors of the three nano-Heusler compounds have been studied and
discussed. It is found that Ferrimagnetic to superparamagnetic transitions were
observed corresponding to different blocking temperatures. Besides, the effect
of the crystal field, the exchange coupling interactions and the external
magnetic field have been inspected on the magnetization of each nano-Heusler
compound Ru$_2$Mn$_X$ ($X$ = Nb, Ta or V).",2109.01708v1
2021-09-07,"Melting of three-sublattice order in triangular lattice Ising antiferromagnets: Power-law order, $Z_6$ parafermionic multicriticality, and weakly first order transitions","The nature of the thermal melting process by which triangular-lattice Ising
antiferromagnets lose their low-temperature ferrimagnetic three-sublattice
order depends on the range of the interactions: It changes character when
second and third neighbour ferromagnetic interactions become comparable to the
nearest-neighbour antiferromagnetic coupling. We present a detailed numerical
characterization of the corresponding threshold at which two-step melting of
three-sublattice order gives way to a direct first-order transition at which
this order is lost. The multicritical behaviour at this threshold is argued to
be in the universality class of the $Z_6$ parafermion conformal field theory
with central charge $c=5/4$. The presence of this multicritical threshold
influences the melting behaviour and long-wavelength properties over a fairly
large range of parameters, and at temperatures that are of the same order as
the exchange interactions. It is therefore of potential experimental relevance
in the context of easy-axis triangular lattice antiferromagnets that display
such low temperature ordering.",2109.03178v1
2021-09-15,Magnetic Compton profile in non-magnetic ferroelectrics,"Magnetic Compton scattering is an established tool for probing magnetism in
ferromagnetic or ferrimagnetic materials with a net spin polarization. Here we
show that, counterintuitively, {\it non-magnetic} systems can also have a
non-zero magnetic Compton profile, provided that space-inversion symmetry is
broken. The magnetic Compton profile is antisymmetric in momentum and, if the
inversion symmetry is broken by an electric-field switchable ferroelectric
distortion, can be reversed using an electric field. We show that the
underlying physics of the magnetic Compton profile and its electrical control
are conveniently described in terms of $k$-space magnetoelectric multipoles,
which are reciprocal to the real-space charge dipoles associated with the
broken inversion symmetry. Using the prototypical ferroelectric lead titanate,
PbTiO$_3$, as an example, we show that the ferroelectric polarization
introduces a spin asymmetry in momentum space that corresponds to a pure
$k$-space magnetoelectric toroidal moment. This in turn manifests in an
antisymmetric magnetic Compton profile which can be reversed using an electric
field. Our work suggests an experimental route to directly measuring and tuning
hidden $k$-space magnetoelectric multipoles via their magnetic Compton profile.",2109.07315v1
2021-09-23,Giant magnetostriction and nonsaturating electric polarization up to 60 T in the polar magnet CaBaCo4O7,"Giant magnetostriction in insulating magnetic materials is highly required
for applications but is rarely observed. Here we show that giant
magnetostriction (> 1500 ppm) can be achieved in an insulating transition metal
oxide CaBaCo4O7 where the ferrimagnetic ordering at TC ~ 62 K is associated
with a huge change in the lattice. Moreover, because this material is
pyroelectric with a non-switchable electric polarization (P), the giant
magnetostriction results in a record-breaking magnetoelectric effect - a
gigantic change of electric polarization (deltaP ~ 1.6 {\mu}C/cm2) in response
to the applied magnetic field up to 60 T. Geometric frustration as well as the
orbital instability of Co2+/Co3+ ions is believed to play a crucial role in the
giant magnetostriction. Our study provides new insights on how to achieve both
giant magnetostriction and pronounced magnetoelectric effect in insulating
transition metal oxides.",2109.11149v1
2021-09-23,Percolation on Lieb lattices,"We study site- and bond-percolation on a class of lattices referred to as
Lieb lattices. In two dimensions the Lieb lattice (LL) is also known as the
decorated square lattice, or as the CuO$_2$ lattice; in three dimensions it can
be generalized to a layered Lieb lattice (LLL) or to a perovskite lattice (PL).
Emergent electronic phenomena, such as topological states and ferrimagnetism,
have been predicted to occur in these systems, which may be realized in optical
lattices as well as in solid state. Since the study of the interplay between
quantum fluctuations and disorder in these systems requires the availability of
accurate estimates of geometrical critical parameters, such as percolation
thresholds and correlation length exponents, here we use Monte Carlo
simulations to obtain these data for Lieb lattices when a site (or bond) is
present with probability $p$. We have found that the thresholds satisfy a
mean-field (Bethe lattice) trend, namely that the critical concentration,
$p_c$, increases as the average coordination number decreases; our estimates
for the correlation length exponent are in line with the expectation that there
is no change in the universality class.",2109.11384v1
2021-10-07,Ultrafast element- and depth-resolved magnetization dynamics probed by transverse magneto-optical Kerr effect spectroscopy in the soft x-ray range,"We report on time- and angle-resolved transverse magneto-optical Kerr effect
spectroscopy in the soft x-ray range that, by analysis via
polarization-dependent magnetic scattering simulations, allows us to determine
the spatio-temporal and element-specific evolution of femtosecond laser-induced
spin dynamics in nanostructured magnetic materials. In a ferrimagnetic GdFe
thin film system, we correlate a reshaping spectrum of the magneto-optical Kerr
signal to depth-dependent magnetization dynamics and disentangle contributions
due to non-equilibrium electron transport and nanoscale heat diffusion on their
intrinsic time scales. Our work provides a quantitative insight into
light-driven spin dynamics occurring at buried interfaces of complex magnetic
heterostructures, which can be tailored and functionalized for future
opto-spintronic devices.",2110.03599v2
2021-11-12,Classical analog of qubit logic based on a magnon Bose-Einstein condensate,"We present a classical version of several quantum bit (qubit) functionalities
using a two-component magnon Bose-Einstein condensate formed at opposite
wavevectors in a room-temperature yttrium-iron-garnet ferrimagnetic film. The
macroscopic wavefunctions of these two condensates serve as orthonormal basis
states that form a system being a classical counterpart of a single qubit.
Solving the Gross-Pitaevskii equation and employing micromagnetic numerical
simulations, we first show how to initialize the system in one of the basis
states: the application of wavevector-selective parallel parametric pumping
allows us to form only a single condensate in one of the two lowest energy
states of the magnon gas. Next, by translating the concept of Rabi-oscillations
into the wavevector domain, we demonstrate how to manipulate the magnon-BEC
system along the polar axis in the Bloch sphere representation. We also discuss
the manipulation regarding the azimuthal angle.",2111.06798v2
2021-11-14,Single-sideband microwave-to-optical conversion in high-Q ferrimagnetic microspheres,"Coherent conversion of microwave and optical photons can significantly expand
the ability to control the information processing and communication systems.
Here, we experimentally demonstrate the microwave-to-optical frequency
conversion in a magneto-optical whispering gallery mode microcavity. By
applying a magnetic field parallel to the microsphere equator, the intra-cavity
optical field will be modulated when the magnon is excited by the microwave
drive, leading to microwave-to-optical conversion via the magnetic Stokes and
anti-Stokes scattering processes. The observed single sideband conversion
phenomenon indicates a non-trivial optical photon-magnon interaction mechanism,
which is derived from the magnon induced both the frequency shift and modulated
coupling rate of optical modes. In addition, we demonstrate the single-sideband
frequency conversion with an ultrawide tuning range up to 2.5GHz, showing its
great potential in microwave-to-optical conversion.",2111.07325v1
2021-11-16,Optical sensing of magnons via the magnetoelastic displacement,"We show how to measure a steady-state magnon population in a magnetostatic
mode of a ferromagnet or ferrimagnet, such as yttrium iron garnet. We adopt an
optomechanical approach and utilize the magnetoelasticity of the ferromagnet.
The magnetostrictive force dispersively couples magnons to the deformation
displacement of the ferromagnet, which is proportional to the magnon
population. By further coupling the mechanical displacement to an optical
cavity that is resonantly driven by a weak laser, the magnetostrictively
induced displacement can be sensed by measuring the phase quadrature of the
optical field. The phase shows an excellent linear dependence on the magnon
population for a not very large population, and can thus be used as a
`magnometer' to measure the magnon population. We further study the effect of
thermal noises, and find a high signal-to-noise ratio even at room temperature.
At cryogenic temperatures, the resolution of magnon excitation numbers is
essentially limited by the vacuum fluctuations of the phase, which can be
significantly improved by using a squeezed light.",2111.08376v2
2021-12-02,"Phases of rotating baryonic matter: non-Abelian chiral soliton lattices, antiferro-isospin chains, and ferri/ferromagnetic magnetization","A chiral soliton lattice (CSL), proposed as the ground state of rotating
baryonic matter at a finite density, is shown to be unstable in a large
parameter region for two flavors owing to pion condensations, leading to two
types of non-Abelian (NA) CSL phases (dimer and deconfining phases). We
determine the phase diagram where the dimer phase meets the other phases and
QCD vacuum at three tricritical points. The critical angular velocity for
NA-CSLs is lower than the $\eta$-CSL. Each NA soliton carries an isospin, and
an antiferro-isospin chain is formed leading to gapless isospinons. The
anomalous coupling to the magnetic field provides the NA-CSL ($\eta$-CSL) with
a ferrimagnetic (ferromagnetic) magnetization.",2112.01381v1
2021-12-27,Observation of magnon cross-Kerr effect in cavity magnonics,"When there is a certain amount of field inhomogeneity, the biased
ferrimagnetic crystal will exhibit the higher-order magnetostatic (HMS) mode in
addition to the uniform-precession Kittel mode. In cavity magnonics, we show
both experimentally and theoretically the cross-Kerr-type interaction between
the Kittel mode and HMS mode. When the Kittel mode is driven to generate a
certain number of excitations, the HMS mode displays a corresponding frequency
shift and vice versa. The cross-Kerr effect is caused by an exchange
interaction between these two spin-wave modes. Utilizing the cross-Kerr effect,
we realize and integrate a multi-mode cavity magnonic system with only one
yttrium iron garnet (YIG) sphere. Our results will bring new methods to
magnetization dynamics studies and pave a way for novel cavity magnonic devices
by including the magnetostatic mode-mode interaction as an operational degree
of freedom.",2112.13807v1
2021-12-27,An Effective Field Theory of Magneto-Elasticity,"We utilize the coset construction to derive the effective field theory of
magnon-phonon interactions in (anti)-ferromagnetic and ferrimagnetic insulating
materials. The action is used to calculate the equations of motion which
generalize the Landau-Lifshitz and stress equations to allow for
magneto-acoustic couplings to all orders in the fields at lowest order in the
derivative expansion. We also include the symmetry breaking effects due to
Zeeman, and Dzyaloshinsky-Moriya interactions. This effective theory is a
toolbox for the study of magneto-elastic phenomena from first principles. As an
example we use this theory to calculate the leading order contribution to the
magnon decay width due to its the decay into phonons.",2112.13873v3
2022-01-10,A theory for anisotropic magnetoresistance in materials with two vector order parameters,"Anisotropic magnetoresistance (AMR) and related planar Hall resistance (PHR)
are ubiquitous phenomena of magnetic materials. Although the universal angular
dependences of AMR and PHR in magnetic polycrystalline materials with one order
parameter are well known, no similar universal relation for other class of
magnetic materials are known to date. Here I present a general theory of
galvanomagnetic effects in magnetic materials with two vector order parameters,
such as magnetic single crystals with a dominated crystalline axis or
polycrystalline non-collinear ferrimagnetic materials. It is shown that AMR and
PHR have a universal angular dependence. In general, both longitudinal and
transverse resistivity are non-reciprocal in the absence of inversion symmetry:
Resistivity takes different value when the current is reversed. Different from
simple magnetic polycrystalline materials where AMR and PHR have the same
magnitude, and $\pi/4$ out of phase, the magnitude of AMR and PHR of materials
with two vector order parameters are not the same in general, and the phase
difference is not $\pi/4$. Instead of $\pi$ periodicity of the usual AMR and
PHR, the periodicities of materials with two order parameters are $2\pi$.",2201.03316v1
2022-01-31,Disorder-mediated quenching of magnetization in NbVTiAl: Theory and Experiment,"In this paper, we present the structural, electronic, magnetic and transport
properties of a equiatomic quaternary alloy NbVTiAl. The absence of (111) and
(200) peaks in X-ray diffraction (XRD) data confirms the A2-type structure.
Magnetization measurements indicate a high Curie temperature and a negligibly
small magnetic moment ($\sim 10^{-3} \mu_B/f.u.$) These observations are
indicative of fully compensated ferrimagnetism in the alloy.
Temperature-dependent resistivity indicates metallic nature. Ab-initio
calculation of fully ordered NbVTiAl structure confirms a nearly half metallic
behavior with a high spin polarization ($\sim$ 90 \%) and a net magnetic moment
of 0.8 $\mu_B/f.u.$ (in complete contrast to the experimental observation). One
of the main objective of the present paper is to resolve and explain the
long-standing discrepancy between theoretical prediction and experimental
observation of magnetization for V-based quaternary Heusler alloys, in general.
To gain an in-depth understanding, we modelled various disordered states and
its subsequent effect on the magnetic and electronic properties. The
discrepancy is attributed to the A2 disorder present in the system, as
confirmed by our XRD data. The presence of disorder also causes the emergence
of finite states at the Fermi level, which impacts the spin polarization of the
system.",2201.13037v1
2022-02-15,Optically-induced magnetization switching in NiCo2O4 thin films using ultrafast lasers,"Recently, all-optical magnetization control has been garnering considerable
attention in realizing next-generation ultrafast magnetic information devices.
Here, employing a magneto-optical Kerr effect (MOKE) microscope, we observed
the laser-induced magnetization switching of ferrimagnetic oxide NiCo2O4 (NCO)
epitaxial thin films with perpendicular magnetic anisotropy, where the sample
was pumped at 1030-nm laser pulses, and magnetic domain images were acquired
via the MOKE microscope with a white light emitting diode. Laser pulses
irradiated an NCO thin film at various temperatures from 300 K to 400 K while
altering the parameters of pulse interval, fluence, and the number of pulses
with the absence of the external magnetic field. We observed accumulative
all-optical switching at 380 K and above. Our observation of oxide NCO thin
films facilitates the realization of chemically stable magnetization switching
using ultrafast lasers, and without applying a magnetic field.",2202.07257v1
2022-02-22,Magnetic properties of equiatomic CrMnFeCoNi,"Magnetic, specific heat, and structural properties of the equiatomic Cantor
alloy system are reported for temperatures between 5 kelvin and 300 kelvin, and
up to fields of 70 kilo-oersted. Magnetization measurements performed on
as-cast, annealed, and cold-worked samples reveal a strong processing history
dependence and that high-temperature annealing after cold-working does not
restore the alloy to a pristine state. Measurements on known precipitates show
that the two transitions, detected at 43 kelvin and 85 kelvin, are intrinsic to
the Cantor alloy and not the result of an impurity phase. Experimental and ab
initio density functional theory (DFT) computational results suggest that these
transitions are a weak ferrimagnetic transition and a spin-glass-like
transition, respectively, and magnetic and specific heat measurements provide
evidence of significant Stoner enhancement and electron-electron interactions
within the material.",2202.11073v1
2022-03-08,Enhancement of thermal spin pumping by orbital angular momentum of rare earth iron garnet,"In a bilayer of ferromagnetic and non-magnetic metal, spin pumping can be
generated by a thermal gradient. The spin current generation depends on the
spin mixing conductance of the interface and the magnetic properties of the
ferromagnetic layer. Due to its low intrinsic damping, rare earth iron garnet
is often used for the ferromagnetic layer in the spin Seebeck experiment.
However, it is actually a ferrimagnetic with antiferromagnetically coupled
magnetic lattices and the contribution of rare earth magnetic lattice of rare
earth iron garnet on thermal spin pumping is not well understand. Here we focus
on the effect of magnetic properties of lanthanide and show that the orbital
angular momentum of rare earth iron garnet enhances thermal spin current
generation of lanthanide substituted yttrium iron garnet.",2203.03915v2
2022-03-18,Plasmonic dichroism and all-optical magnetization switching in nanophotonic structures with GdFeCo,"We report on a phenomenon of plasmonic dichroism observed in magnetic
materials with the transverse magnetization under the excitation of the surface
plasmon polariton waves. The effect originates from the interplay of the two
magnetization-dependent contributions to the material absorption, both of which
are enhanced under plasmon excitation. Similar to the recently discovered
effect of a all-optical helicity-dependent magnetization switching, this effect
provides a possibility to perform a deterministic magnetization switching to
the desired state. We show by electromagnetic modeling that laser pulses
exciting counter-propagating plasmons can be used to write +M or -M state in a
deterministic way independent on the initial magnetization state. The presented
approach applies to various ferrimagnetic materials exhibiting the phenomenon
of all-optical switching of thermal nature and broadens the horizons of their
applications in data storage devices.",2203.09956v1
2022-03-22,A strategic high throughput search for identifying stable Li based half Heusler alloys for spintronics applications,"In this work, high throughput DFT calculations are performed on the alkali
metal-based half Heusler alloys; LiY$_p$Y$^\prime_{1-p}$S (Y, Y$^\prime$ = V,
Cr, Mn, Fe, Co, Ni and $\mathit{p}$ = 0, 0.25, 0.5, 0.75, 1). Starting with 243
structural replica, systematic filters are designed to select the energetically
and vibrationally favorable compositions by considering the contributions
stemming from the magnetic alignments of the ions. Thereby, 26 dynamically
stable magnetic compositions are identified, of which 10 are found to be
ferromagnetic (FM), 4 antiferromagnetic (AFM) and 12 ferrimagnetic (FiM). 4 FM
and 8 FiM ones are found to show 100 $\%$ spin polarization. Further,
tetragonal distortion is found to be present in 4 FM, 3 FiM and 4 AFM
compositions, which indicates the possibility of easy-axis magnetocrystalline
anisotropy. The ferromagnetic LiFe$_{0.5}$Mn$_{0.5}$S and antiferromagnetic
LiFeS are found to have the most prominent easy-axis magnetocrystalline
anisotropy.",2203.11794v1
2022-03-30,Ferromagnetism and doublon localization in a Wannier-Hubbard chain,"We derive a ""Wannier-Hubbard"" model consisting of an array of overlapping
atomic orbitals interacting via a local Coulomb interaction. Transforming to an
orthogonal Wannier basis set, the resulting Hamiltonian displays long range
hopping and interactions, with new terms such as correlated hopping and
ferromagnetic direct exchange, among others. We numerically study the
one-dimensional version of the model at half-filling using the density matrix
renormalization group (DMRG) method, unveiling a rich phase diagram as a
function of the interaction $U$ and the overlap $s$ with metallic, and
ferromagnetic phases, separated by a ferrimagnetic region. Our results indicate
a path toward understanding new emergent phases under pressure and beyond
standard model Hamiltonians.",2203.16483v2
2022-04-01,Effect of interfacial spin mixing conductance on gyromagnetic ratio of Gd substituted Y$_{3}$Fe$_{5}$O$_{12}$,"Due to its low intrinsic damping, Y$_3$Fe$_5$O$_{12}$ and its substituted
variations are often used for ferromagnetic layer at spin pumping experiment.
Spin pumping is an interfacial spin current generation in the interface of
ferromagnet and non-magnetic metal, governed by spin mixing conductance
parameter $G^{\uparrow\downarrow}$. $G^{\uparrow\downarrow}$ has been shown to
enhance the damping of the ferromagnetic layer. The theory suggested that the
effect of $G^{\uparrow\downarrow}$ on gyromagnetic ratio only come from its
negligible imaginary part. In this article, we show that the different damping
of ferrimagnetic lattices induced by $G^{\uparrow\downarrow}$ can affect the
gyromagnetic ratio of Gd-substituted Y$_3$Fe$_5$O$_{12}$.",2204.00310v1
2022-04-07,Topological multiferroic order in twisted transition metal dichalcogenide bilayers,"Layered van der Waals materials have risen as powerful platforms to
artificially engineer correlated states of matter. Here we show the emergence
of a multiferroic order in a twisted dichalcogenide bilayer superlattice at
quarter-filling. We show that the competition between Coulomb interactions
leads to the simultaneous emergence of ferrimagnetic and ferroelectric orders.
We derive the magnetoelectric coupling for this system, which leads to a direct
strong coupling between the charge and spin orders. We show that, due to
intrinsic spin-orbit coupling effects, the electronic structure shows a
non-zero Chern number, thus displaying a topological multiferroic order. We
show that this topological state gives rise to interface modes at the different
magnetic and ferroelectric domains of the multiferroic. We demonstrate that
these topological modes can be tuned with external electric fields as well as
triggered by supermoire effects generated by a substrate. Our results put
forward twisted van der Waals materials as a potential platform to explore
multiferroic symmetry breaking orders and, ultimately, controllable topological
excitations in magnetoelectric domains.",2204.03360v2
2022-04-14,Tuning the coexistence regime of incomplete and tubular skyrmions in ferro/ferri/ferromagnetic trilayers,"The development of skyrmionic devices requires a suitable tuning of material
parameters in order to stabilize skyrmions and control their density. It has
been demonstrated recently that different skyrmion types can be simultaneously
stabilized at room temperature in heterostructures involving ferromagnets,
ferrimagnets and heavy metals, offering a new platform of coding binary
information in the type of skyrmion instead of the presence/absence of
skyrmions. Here, we tune the energy landscape of the two skyrmion types in such
heterostructures by engineering the geometrical and material parameters of the
individual layers. We find that a fine adjustment of the ferromagnetic layer
thickness and thus its magnetic anisotropy, allows the trilayer system to
support either one of the skyrmion types or the coexistence of both and with
varying densities.",2204.06808v2
2022-05-06,Vacuum material properties and Cherenkov radiation in Logarithmic Electrodynamics,"We study some observational signatures of nonlinearities of the
electromagnetic field. First to all we show the vital role played by
nonlinearities in triggering a material behavior of the vacuum with
$(\varepsilon > 0, \mu <0)$, which corresponds to a ferrimagnetic material.
Secondly, the permittivity and susceptibility induced by nonlinearities are
considered in order to obtain the refractive index via the dispersion relation
for logarithmic electrodynamics. Finally, we consider the electromagnetic
radiation produced by a moving charged particle interacting with a medium
characterized by nonlinearities of the electromagnetic field. To this end we
consider logarithmic electrodynamics. The result shows that the radiation is
driven by the medium through which the particle travels like the one that
happens in the Cherenkov effect.",2205.03252v1
2022-05-10,"Structural, electronic and magnetic properties of La$_{1.5}$Ca$_{0.5}$(Co$_{0.5}$Fe$_{0.5}$)IrO$_6$ double perovskite","In this work, we report the synthesis and investigation of structural,
electronic, and magnetic properties of
La$_{1.5}$Ca$_{0.5}$(Co$_{0.5}$Fe$_{0.5}$)IrO$_6$. Our polycrystalline sample
forms as a single-phase double perovskite in monoclinic $P2_{1}/n$ space group.
Co and Ir are most likely in bivalent and tetravalent oxidation states,
respectively, while Mossbauer spectroscopy indicates that Fe is in a trivalent
state. The ac and dc magnetization data suggest a ferrimagnetic behavior
resulting from the presence of two antiferromagnetic sublattices at Co/Fe and
Ir sites. The large coercive field H_C $\simeq$ 32 kOe observed at 10 K,
comparable to that of other double perovskites of interest for hard magnets, is
discussed in terms of the structural distortion and the spin and orbital
magnetic moments of the transition metal ions.",2205.04778v1
2022-06-08,Metal-insulator transition in the disordered Hubbard model of the Lieb lattice,"Using the determinant quantum Monte Carlo method, we investigate the
metal-insulator transition in the interacting disordered Hubbard model of a
Lieb lattice, in which the system characterizes the flat band centered at the
Fermi level. By choosing suitable electron densities, we ensure the weak
interaction sign problem to improve the reliability of our results. It is found
that disorder and on-site Coulomb repulsive interaction produce interesting
effects that induce the metal-insulator transition which is impossible in the
half-filled case. The density of states at the Fermi energy is still finite in
the thermodynamic limit, suggesting that the system is an Anderson insulator
rather than a Mott insulator. Moreover, this doping system is paramagnetic,
unlike the half-filled system, which is ferrimagnetic.",2206.03890v1
2022-06-12,Stationary optomagnonic entanglement and magnon-to-optics quantum state transfer via opto-magnomechanics,"We show how to prepare a steady-state entangled state between magnons and
optical photons in an opto-magnomechanical configuration, where a mechanical
vibration mode couples to a magnon mode in a ferrimagnet by the dispersive
magnetostrictive interaction, and to an optical cavity by the radiation
pressure. We find that, by appropriately driving the magnon mode and the cavity
to simultaneously activate the magnomechanical Stokes and the optomechanical
anti-Stokes scattering, a stationary optomagnonic entangled state can be
created. We further show that, by activating the magnomechanical state-swap
interaction and subsequently sending a weak red-detuned optical pulse to drive
the cavity, the magnonic state can be read out in the cavity output field of
the pulse via the mechanical transduction. The demonstrated entanglement and
state-readout protocols in such a novel opto-magnomechanical configuration
allow us to optically control, prepare, and read out quantum states of
collective spin excitations in solids, and provide promising opportunities for
the study of quantum magnonics, macroscopic quantum states, and magnonic
quantum information processing.",2206.05688v3
2022-06-29,Mechanical Bistability in Kerr-modified Cavity Magnomechanics,"Bistable mechanical vibration is observed in a cavity magnomechanical system,
which consists of a microwave cavity mode, a magnon mode, and a mechanical
vibration mode of a ferrimagnetic yttrium-iron-garnet (YIG) sphere. The
bistability manifests itself in both the mechanical frequency and linewidth
under a strong microwave drive field, which simultaneously activates three
different kinds of nonlinearities, namely, magnetostriction, magnon self-Kerr,
and magnon-phonon cross-Kerr nonlinearities. The magnon-phonon cross-Kerr
nonlinearity is first predicted and measured in magnomechanics. The system
enters a regime where Kerr-type nonlinearities strongly modify the conventional
cavity magnomechanics that possesses only a radiation-pressure-like
magnomechanical coupling. Three different kinds of nonlinearities are
identified and distinguished in the experiment. Our work demonstrates a new
mechanism for achieving mechanical bistability by combining magnetostriction
and Kerr-type nonlinearities, and indicates that such Kerr-modified cavity
magnomechanics provides a unique platform for studying many distinct
nonlinearities in a single experiment.",2206.14588v2
2022-07-06,Topological magnons on the triangular kagome lattice,"We present the topology of magnons on the triangular kagome lattice (TKL) by
calculating its Berry curvature, Chern number and edge states. In addition to
the ferromagnetic state, the TKL hosts ferrimagnetic ground state as its two
sublattices can couple with each other either ferromagnetically or
antiferromagnetically. Using Holstein-Primakoff (HP) boson theory and Green's
function approach, we find that the TKL has a rich topological band structure
with added high Chern numbers compared with the kagome and honeycomb lattices.
The magnon edge current allows a convenient calculation of thermal Hall
coefficients and the orbital angular momentum gives correlation to the
Einstein-de Haas effect. We apply the calculations to the TKL and derive the
topological gyromagnetic ratio showing a nonzero Einstein-de Haas effect in the
zero temperature limit. Our results render the TKL as a potential platform for
quantum magnonics applications including high-precision mechanical sensors and
information transmission.",2207.02886v2
2022-08-05,Interfacial phase frustration stabilizes unconventional skyrmion crystals,"Chiral magnetic phases with an unconventional topological twist in the
magnetization are of huge interest due to their potential in spintronics
applications. Here, we present a general method to induce such exotic magnetic
phases using interfacial phase frustration within artificially grown
superlattices. To demonstrate our method, we consider a multilayer with two
different chiral magnetic phases as the competing orders at the top and bottom
and show, using Monte Carlo calculations, that the interfacial phase
frustration is realized at the central layer. In particular, we obtain three
unconventional phases: a checkerboard skyrmion crystal, an incommensurate
skyrmion stripe, and a ferrimagnetic skyrmion crystal. In these
frustration-induced phases, the spin chirality driven topological Hall
conductivity can be largely enhanced. This method provides a playground to
realize unconventional magnetic phases in any family of materials that can be
grown in superlattices.",2208.03255v1
2022-08-23,Microwave-optics Entanglement via Cavity Optomagnomechanics,"Microwave-optics entanglement is a vital component for building hybrid
quantum networks. Here, a new mechanism for preparing stationary entanglement
between microwave and optical cavity fields in a cavity optomagnomechanical
system is proposed. It consists of a magnon mode in a ferrimagnetic crystal
that couples directly to a microwave cavity mode via the magnetic dipole
interaction, and indirectly to an optical cavity through the deformation
displacement of the crystal. The mechanical displacement is induced by the
magnetostrictive force and coupled to the optical cavity via radiation
pressure. Both the opto- and magnomechanical couplings are dispersive.
Magnon-phonon entanglement is created via magnomechanical parametric
down-conversion, which is further distributed to optical and microwave photons
via simultaneous optomechanical beamsplitter interaction and electromagnonic
state-swap interaction, yielding stationary microwave-optics entanglement. The
microwave-optics entanglement is robust against thermal noise, which will find
broad potential applications in quantum networks and quantum information
processing with hybrid quantum systems.",2208.10703v2
2022-08-23,Reversal of nanomagnets by propagating magnons in ferrimagnetic yttrium iron garnet enabling nonvolatile magnon memory,"Despite the unprecedented downscaling of CMOS integrated circuits,
memory-intensive machine learning and artificial intelligence applications are
limited by data conversion between memory and processor. There is a challenging
quest for novel approaches to overcome this so-called von Neumann bottleneck.
Magnons are the quanta of spin waves and transport angular momenta through
magnets. They enable power-efficient computation without charge flow and would
solve the conversion problem if spin wave amplitudes could be stored directly
in a magnetic memory cell. Here, we report the reversal of ferromagnetic
nanostripes by spin waves which propagate through an underlying spin-wave bus
made from yttrium iron garnet. Thereby, the charge-free angular momentum flow
is stored after transmission over a macroscopic distance. We show that spin
waves can reverse large arrays of ferromagnetic stripes at a strikingly small
power level of nW. Combined with the already existing wave logic, our discovery
is path-breaking for the new era of magnonics-based in-memory computation and
beyond von Neumann computer architectures.",2208.10923v1
2022-08-31,Unusual kinetic properties of usual Heusler alloys,"The review considers various groups of Heusler compounds, which can have the
properties of a semiconductor, a half-metallic ferromagnet, a spin gapless
semiconductor, a topological semimetal, and a noncollinear antiferromagnet. In
these Heusler compounds, ""conventional"" from the point of view of the crystal
structure, unusual kinetic and magnetic properties can be observed, which are
caused by the features of their electronic structure (e.g., presence of an
energy gap for one spin projection) and magnetic state (e.g., strong
ferromagnetism, compensated ferrimagnetism, etc.). Their magnetic and kinetic
characteristics are very sensitive to external influences. Depending on the
alloy composition and external parameters, transitions between the considered
states can be realized. All this opens up further prospects for controlling the
electronic and magnetic characteristics of such compounds and their practical
application.",2208.14868v1
2022-09-06,Spin-phonon interaction and short range order in $\mathrm{Mn_3Si_{2}Te_6}$,"The vibrational properties of ferrimagnetic $\mathrm{Mn_3Si_{2}Te_6}$ single
crystals are investigated using Raman spectroscopy and density functional
theory calculations. Eighteen Raman-active modes are identified, fourteen of
which are assigned according to with the trigonal symmetry. Four additional
peaks, obeying the $A_{1g}$ selection rules, are attributed to the overtones.
The unconventional temperature evolution of the $A_{1g}^5$ mode self-energy
suggests a competition between different short-range magnetic correlations that
significantly impact the spin-phonon interaction in $\mathrm{Mn_3Si_{2}Te_6}$.
The research provides a comprehensive insight to the lattice properties,
studies their temperature dependence and shows the arguments for existence of
competing short-range magnetic phases in $\mathrm{Mn_3Si_{2}Te_6}$.",2209.02664v1
2022-10-03,Chirality-induced one-way quantum steering between two waveguide-mediated ferrimagnetic microspheres,"One-way quantum steering is of importance for quantum technologies, such as
secure quantum teleportation. In this paper, we study the generation of one-way
quantum steering between two distant yttrium iron garnet (YIG) microspheres in
chiral waveguide electromagonics. We consider that the magnon mode with the
Kerr nonlinearity in each YIG sphere is chirally coupled to left- and
right-propagating guided photons in the waveguide. We find that quantum
steering between the magnon modes is absent with non-chirality but is present
merely in the form of one way (i.e., one-way steering) when the chirality
occurs. The maximal achievable steering is obviously improved as the chirality
degree increases. We further find that when the waveguide's outputs are
subjected to continuous homodyne detection, the steering can be considerably
enhanced and asymmetric steering with strong entanglement can also be achieved
by tuning the chirality. Our study shows that chirality can be explored to
effectively realize one-way quantum steering. Compared to other studies on
achieving asymmetric steering via controlling intrinsic dissipation, e.g.
cavity loss rates, our scheme merely depends on the chirality enabled via
positioning the micromagnets in the waveguide and is continuously adjustable
and experimentally more feasible.",2210.00710v1
2022-10-10,Three-state Potts nematic order in stacked frustrated spin models with SO(3) symmetry,"We propose stacked two-dimensional lattice designs of frustrated and SO(3)
symmetric spin models consisting of antiferromagnetic (AFM) triangular and
ferromagnetic (FM) sixfold symmetric sublattices that realize emergent Z3 Potts
nematic order. Considering bilinear-biquadratic spin interactions, our models
describe an SO(3)-symmetric triangular lattice AFM subject to a fluctuating
magnetization arising from the FM coupled sublattice. We focus on the classical
AFM-FM windmill model and map out the zero- and finite-temperature phase
diagram using Monte Carlo simulations and analytical calculations. We discover
a state with composite Potts nematic order above the ferrimagnetic
three-sublattice up-up-down ground state and relate it to Potts phases in
SO(3)-broken Heisenberg and Ising AFMs in external magnetic fields. Finally, we
show that the biquadratic exchange in our model is automatically induced by
thermal and quantum fluctuations in the purely bilinear Heisenberg model,
easing the requirements for realizing these lattice designs experimentally.",2210.04900v2
2022-11-02,Pump--probe x-ray microscopy of photo-induced magnetization dynamics at MHz repetition rates,"We present time-resolved scanning x-ray microscopy measurements with
picosecond photo-excitation via a tailored infrared pump laser at a scanning
transmission x-ray microscope. Specifically, we image the laser-induced
demagnetization and remagnetization of thin ferrimagnetic GdFe films proceeding
on a few nanoseconds time scale. Controlling the heat load on the sample via
additional reflector and heat-sink layers allows us to conduct destruction-free
measurements at a repetition rate of \SI{50}{\mega\hertz}. Near-field
enhancement of the photo-excitation and controlled annealing effects lead to
laterally heterogeneous magnetization dynamics which we trace with
\SI{30}{\nano\meter} spatial resolution. Our work opens new opportunities to
study photo-induced dynamics on the nanometer scale, with access to picosecond
to nanosecond timescales, which is of technological relevance, especially in
the field of magnetism.",2211.01230v2
2022-12-01,Nonreciprocal Phonon Propagation in a Metallic Chiral Magnet,"The phonon magnetochiral effect (MChE) is the nonreciprocal acoustic and
thermal transports of phonons caused by the simultaneous breaking of the mirror
and time-reversal symmetries. So far, the phonon MChE has been observed only in
a ferrimagnetic insulator Cu2OSeO3, where the nonreciprocal response disappears
above the Curie temperature of 58 K. Here, we study the nonreciprocal acoustic
properties of a room-temperature ferromagnet Co9Zn9Mn2 for unveiling the phonon
MChE close to the room temperature. Surprisingly, the nonreciprocity in this
metallic compound is enhanced at higher temperatures and observed up to 250 K.
This clear contrast between insulating Cu2OSeO3 and metallic Co9Zn9Mn2 suggests
that metallic magnets have a mechanism to enhance the nonreciprocity at higher
temperatures. From the ultrasound and microwave-spectroscopy experiments, we
conclude that the magnitude of the phonon MChE of Co9Zn9Mn2 mostly depends on
the magnon bandwidth, which increases at low temperatures and hinders the
magnon-phonon hybridization. Our results suggest that the phonon nonreciprocity
could be further enhanced by engineering the magnon band of materials.",2212.00225v2
2022-12-14,Ordered creation and motion of skyrmions with surface acoustic wave,"Magnetic skyrmions with a well-defined spin texture have shown unprecedented
potential for various spintronic applications owning to their topologically
non-trivial and quasiparticle properties. To put skyrmions into practical
technology, efficient manipulation, especially the inhibition of skyrmion Hall
effect (SkHE) has been intensively pursued. In spite of the recent progress
made on reducing SkHE in several substituted systems, such as ferrimagnets and
synthetic antiferromagnets, the organized creation and current driven motion of
skyrmions with negligible SkHE in ferromagnets remain challenging. Here, by
embeding the [Co/Pd] multilayer into a surface acoustic wave (SAW) delay line,
we experimentally realized the ordered generation of magnetic skyrmions. The
resultant current-induced skyrmions movement with negligible SkHE was observed,
which can be attributed to the energy redistribution of the system during the
excitation of SAW. Our findings open up an unprecedentedly new perspective for
manipulating topological solitons, and would advance the development of
skyrmionics and spin acousto-electronics.",2212.06997v1
2022-12-15,Electric field tuning of magnetic states in single magnetic molecules,"Single magnetic molecules may be the smallest functional magnets. An
electric-field controllable spin state of magnetic molecules is of fundamental
importance for applications while its realization remains challenging. To date
the observed spin-electric interaction based on spin-orbit coupling or spin
dipole coupling is useful to tune fine spin structures but too weak to flip the
spin state. In this work, we propose a new mechanism to realize enhanced
spin-electric coupling and flip the spin states by tuning the spin
superexchange between local spins. Using first-principles calculations and
Heisenberg Hamiltonian, we demonstrate this effect in a family of magnetic
molecules, transition metallic Porphyrins. We show that their d-{\pi} and
{\pi}-{\pi} spin superexchange couplings are determined by the relative
energies of d and {\pi} electronic states, which are sensitive to the applied
electric field. Therefore, applying electric field can tune a wide range of
magnetic ground states, including ferromagnetic, ferrimagnetic, and
antiferromagnetic configurations. This spin-electric coupling may provide a new
approach for designing and controlling molecular spintronics.",2212.08010v1
2023-02-07,Sputtered terbium iron garnet films with perpendicular magnetic anisotropy for spintronic applications,"We report the structural, magnetic, and interfacial spin transport properties
of epitaxial terbium iron garnet (TbIG) ultrathin films deposited by magnetron
sputtering. High crystallinity was achieved by growing the films on gadolinium
gallium garnet (GGG) substrates either at high temperature, or at room
temperature followed by thermal annealing, above 750 {\deg}C in both cases. The
films display large perpendicular magnetic anisotropy (PMA) induced by
compressive strain, and tunable structural and magnetic properties through
growth conditions or the substrate lattice parameter choice. The ferrimagnetic
compensation temperature (TM) of selected TbIG films was measured through
temperature-dependent anomalous Hall effect (AHE) in Pt/TbIG heterostructures.
In the studied films, TM was found to be between 190-225 K, i.e., approximately
25-60 K lower than the bulk value, which is attributed to the combined action
of Tb deficiency and oxygen vacancies in the garnet lattice evidenced by x-ray
photoelectron spectroscopy measurements. Sputtered TbIG ultrathin films with
large PMA and highly tunable properties reported here can provide a suitable
material platform for a wide range of spintronic experiments and device
applications.",2302.03758v1
2023-02-09,Single-shot laser-induced switching of an exchange biased antiferromagnet,"Ultrafast manipulation of magnetic order has challenged our understanding the
fundamental and dynamic properties of magnetic materials. So far single shot
magnetic switching has been limited to ferrimagnetic alloys and multilayers. In
ferromagnetic (FM)/antiferromagnetic (AFM) bilayers, exchange bias (He) arises
from the interfacial exchange coupling between the two layers and reflects the
microscopic orientation of the antiferromagnet. Here we demonstrate the
possibility of single shot switching of the antiferromagnet (change of the sign
and amplitude of He) with a single femtosecond laser pulse in IrMn/CoGd
bilayers. We demonstrate the switching for a wide range of fluences for
different layer thicknesses and compositions. Atomistic simulations predict
ultrafast switching and recovery of the AFM magnetization on a timescale of 2
ps. These results provide the fastest and the most energy-efficient method to
set the exchange bias and pave the way to potential applications for ultrafast
spintronic devices.",2302.04510v1
2023-02-06,Chiral and flat-band magnetic cluster excitations in a ferromagnetic kagome metal,"TbMn6Sn6 is a metallic ferrimagnet that displays signatures of band topology
arising from a combination of uniaxial ferromagnetism and spin-orbit coupling
within its Mn kagome layers. Whereas the low energy magnetic excitations can be
described as collective spin waves using a local moment Heisenberg model,
sharply defined optical and flat-band collective magnon modes are not observed.
In their place, we find overdamped chiral and flat-band spin correlations that
are localized to hexagonal plaquettes within the kagome layer.",2302.04846v1
2023-02-17,Control of the magnon-polariton hybridization with a microwave pump,"Pump-induced magnon modes (PIMs) are recently discovered elementary
excitations in ferrimagnets that offer significant tunability to spin dynamics.
Here, we investigate the coupling between a PIM and cavity magnon polaritons
(CMPs) by driving a cavity magnonic system away from equilibrium with a
microwave pump. In our experiment, the Walker mode simultaneously couples with
the PIM and cavity photons and thus combines two strongly coherent coupling
processes in a single cavity structure. Such a PIM-CMP hybridization system
acquires complementary properties from both the PIM and CMPs, allowing it to be
freely manipulated by the magnetic field, the pump power and the pump
frequency. These coherent manipulations exhibit unique behaviors beyond the
intrinsic properties limited by the material nature and electromagnetic
boundary conditions, thereby creating opportunities for extending the control
of hybrid devices.",2302.08665v2
2023-02-26,Highly Tunable Intrinsic Exchange Bias from Interfacial Reconstruction in Epitaxial NixCoyFe3-x-yO4(111)/α-Al2O3(0001) Thin Films,"Intrinsic exchange bias up to 12.6 kOe is observed in
NixCoyFe3-x-yO4(111)/{\alpha}-Al2O3(0001) (0<=x+y<=3) epitaxial thin films
where 0.15<=y<=2. An interfacial layer of rock-salt structure emerges between
NixCoyFe3-x-yO4 thin films and {\alpha}-Al2O3 substrates and is proposed as the
antiferromagnetic layer unidirectionally coupled with ferrimagnetic
NixCoyFe3-x-yO4. In NiCo2O4(111)/{\alpha}-Al2O3(0001) films, results of
reflection high energy electron diffraction, X-ray photoelectron spectroscopy,
X-ray reflectometry, and polarized neutron reflectometry support that the
interfacial layer is antiferromagnetic NixCo1-xO (0.32<=x<=0.49) of rock-salt
structure; the interfacial layer and exchange bias can be controlled by growth
oxygen pressure revealing the key role of oxygen in the mechanism of the
interfacial reconstruction. This work establishes a family of intrinsic
exchange bias materials with great tunability by stoichiometry and growth
parameters and emphasizes the strategy of interface engineering in controlling
material functionalities.",2302.13227v3
2023-03-01,Thermodynamic determination of the equilibrium first-order phase-transition line hidden by hysteresis in a phase diagram,"Phase diagrams form the basis for the study of material science, and the
profiles of phase-transition lines separating different thermodynamic phases
include comprehensive information about thermodynamic quantities, such as
latent heat. However, in some materials exhibiting field-induced first-order
transitions (FOTs), the equilibrium phase-transition line is hidden by the
hysteresis region associated with the FOT; thus, it cannot be directly
determined from measurements of resistivity, magnetization, etc. Here, we
demonstrate a thermodynamics-based method for determining the hidden
equilibrium FOT line. This method is verified for the FOT between
antiferromagnetic and ferrimagnetic states in magneto-electric compounds
(Fe$_{0.95}$Zn$_{0.05}$)$_{2}$Mo$_{3}$O$_{8}$. The equilibrium FOT line
determined based on the Clausius-Clapeyron equation exhibits a reasonable
profile in terms of the third law of thermodynamics, and it shows marked
differences from the midpoints of the hysteresis region. Our findings highlight
that care should be taken for referring to the hysteresis midpoint line when
discussing field-induced latent heat or magnetocaloric effects.",2303.00327v1
2023-04-04,Full quantum theory for magnon transport in two-sublattice magnetic insulators and magnon junctions,"Magnon, as elementary excitation in magnetic systems, can carry and transfer
angular momentum. Due to the absence of Joule heat during magnon transport,
researches on magnon transport have gained considerable interests over the past
decade. Recently, a full quantum theory has been employed to investigate magnon
transport in ferromagnetic insulators (FMIs). However, the most commonly used
magnetic insulating material in experiments, yttrium iron garnet (YIG), is a
ferrimagnetic insulator (FIMI). Therefore, a full quantum theory for magnon
transport in FIMI needs to be established. Here, we propose a Green's function
formalism to compute the magnon bulk and interface current in both FIMIs and
antiferromagnetic insulators (AFMIs). We investigate the spatial distribution
and temperature dependence of magnon current in FIMIs and AFMIs generated by
temperature or spin chemical potential step. In AFMIs, magnon currents
generated by temperature step in the two sublattices cancel each other out.
Subsequently, we numerically simulate the magnon junction effect using the
Green's function formalism, and result shows near 100\% magnon junction ratio.
This study demonstrates the potential for investigating magnon transport in
specific magnonic devices using a full quantum theory.",2304.01930v1
2023-04-21,Magnetic Structures and Spin-wave Excitations in Rare-Earth Iron Garnets near the Compensation Temperature,"We introduce a simple model for the ferrimagnetic non-collinear ``magnetic
umbrella"" states of rare-earth iron garnets (REIG), common when the rare-earth
moments have non-zero orbital angular momentum. The spin-wave excitations are
calculated within linear spin wave theory and temperature effects via
mean-field theory. This could be used to determine the magnetic polarization of
each mode and thereby the spin currents generated by thermal excitations
including the effects of mixed chirality. The spectra reproduce essential
features seen in more complete models, with hybridization between the rare
earth crystal field excitations and the propagating mode on the iron moments.
By the symmetry of the model, only one rare earth mode hybridizes, inducing a
gap at zero wave number and level repulsion at finite frequency. At the
compensation point, the hybridization gap closes and finally, as we approach
the N\'eel temperature, the hybridization gap appears to reopen. The chirality
of the lowest mode changes its sign around the frequency at which the level
repulsion occurs. This is important to estimate the spin current generation in
REIGs.",2304.10695v1
2023-04-26,Rapid-prototyping of microscopic thermal landscapes in Brillouin light scattering spectroscopy,"Since temperature and its spatial and temporal variations affect a wide range
of physical properties of material systems, they can be used to create
reconfigurable spatial structures of various types in physical and biological
objects. This paper presents an experimental optical setup for creating tunable
two-dimensional temperature patterns on a micrometer scale. As an example of
its practical application, we have produced temperature-induced magnetization
landscapes in ferrimagnetic yttrium iron garnet films and investigated them
using micro-focused Brillouin light scattering spectroscopy. It is shown that,
due to the temperature dependence of the magnon spectrum, temperature changes
can be visualized even for microscale thermal patterns.",2304.13658v2
2023-05-15,Magnetic order and electronic transport properties in the Mn$_3$Al compound: the role of the structural state,"Electronic transport and magnetic properties of bulk and rapid melt quenched
samples of the Mn$_3$Al Heusler alloy were studied. A correlation between the
magnetic and structural states was established. For a cast sample, there is no
ferromagnetic moment, and the behavior of the magnetic susceptibility (break at
low temperatures and the Curie-Weiss law with high values of the paramagnetic
Curie temperature) indicates a frustrated antiferromagnetic state. At the same
time, for a rapid melt quenched sample, a ferrimagnetic state is observed with
a moment close to compensation. The results of measurements of the electrical
resistivity and the Hall effect evidence as well in favor of the implementation
of these magnetic states.",2305.08646v1
2023-05-24,Dirac half-semimetallicity and antiferromagnetism in graphene nanoribbon/hexagonal boron nitride heterojunctions,"Half-metals have been envisioned as active components in spintronic devices
by virtue of their completely spin-polarized electrical currents. Actual
materials hosting half-metallic phases, however, remain scarce. Here, we
predict that recently fabricated heterojunctions of zigzag nanoribbons embedded
in two-dimensional hexagonal boron nitride are half-semimetallic, featuring
fully spin-polarized Dirac points at the Fermi level. The half-semimetallicity
originates from the transfer of charges from hexagonal boron nitride to the
embedded graphene nanoribbon. These charges give rise to opposite energy shifts
of the states residing at the two edges while preserving their intrinsic
antiferromagnetic exchange coupling. Upon doping, an
antiferromagnetic-to-ferrimagnetic phase transition occurs in these
heterojunctions, with the sign of the excess charge controlling the spatial
localization of the net magnetic moments. Our findings demonstrate that such
heterojunctions realize tunable one-dimensional conducting channels of
spin-polarized Dirac fermions that are seamlessly integrated into a
two-dimensional insulator, thus holding promise for the development of
carbon-based spintronics.",2305.15214v1
2023-05-29,Magnetic properties of delta- and kagome-like chains with competing interactions,"We study the delta-chain with spin-$1$ on basal sites and spin-$\frac{1}{2}$
on apical sites. The Heisenberg interaction between neighbor basal spins is
antiferromagnetic (AF) and the interaction between basal and apical spins is
ferromagnetic (F). We show that the magnetization curve of this model is the
same as that of the spin-$\frac{1}{2}$ kagome-like chain with competing
Heisenberg interactions. The ground state phase diagram of the latter as a
function of the ratio between the AF and F interaction, $\alpha $, consists of
the ferromagnetic, ferrimagnetic and singlet phases. We study the magnetic
properties in each ground state phase and analyze the magnetization curves. We
show that there are magnetization plateaus and jumps in definite regions of
value $\alpha$. We compare the magnetic properties of considered models with
those of the spin-$\frac{1}{2}$ delta chain.",2305.18124v1
2023-06-01,Inelastic neutron scattering investigation of the crystal field excitations of NdCo$_5$,"We present an inelastic neutron scattering study of the crystal electric
field levels in the intermetallic ferrimagnets RECo$_{5}$ (RE = Nd and Y). In
NdCo$_{5}$, measurements at $5~$K reveal two levels at approximately 28.9 and
52.9 meV. Crystal field calculations including the exchange field
$B_{\textrm{exc}}$ from the Co sites account for both of these, as well as the
spectrum at temperatures above the spin-reorientation transition at $\sim
280$~K. In particular, it is found that both a large hexagonal crystal field
parameter $A_{6}^6\langle r^6 \rangle$ and $B_{\textrm{exc}}$ are required to
reproduce the data, with the latter having a much larger value than that
deduced from previous computational and experimental studies. Our study sheds
light on the delicate interplay of terms in the rare-earth Hamiltonian of
RECo$_5$ systems, and is therefore expected to stimulate further experimental
and computational work on the broader family of rare-earth permanent magnets.",2306.00821v1
2023-06-05,Spin Hall magnetoresistance in Pt/Y$_{3}$Fe$_{5}$O$_{12}$ bilayers grown on Si and Gd$_{3}$Ga$_{5}$O$_{12}$ substrates,"We study spin Hall magnetoresistance (SMR) in Pt/ferrimagnetic insulator
Y$_{3}$Fe$_{5}$O$_{12}$ (YIG) bilayers by focusing on crystallinity,
magnetization, and interface roughness by controlling post-annealing
temperatures. The SMR in the Pt/YIG grown on Si substrate is comparable to that
grown on widely used Gd$_{3}$Ga$_{5}$O$_{12}$ substrate, indicating that the
large SMR can be achieved irrespective to the crystallinity. We deduced the
spin mixing conductance from the Pt thickness dependence of the SMR to find the
high interface quality of the optimized Pt/YIG grown on Si in terms of spin
current. We also clarified that the SMR correlates well with the magnetization,
the interface roughness, and carrier density. These findings highlight that
optimizing YIG properties is a key to control of magnetization by spin current,
leading to the development of low power consumption spintronic device based on
the magnetic insulator.",2306.02575v1
2023-06-12,Insight into the structural and magnetotransport properties of epitaxial heterostructures $α$-Fe$_2$O$_3$-Pt(111): Role of the reversed layer sequence,"We report on the chemical structure and spin Hall magnetoresistance (SMR) in
epitaxial $\alpha$-Fe$_2$O$_3$(hematite)(0001)/Pt(111) bilayers with hematite
thicknesses of 6 nm and 15 nm grown by molecular beam epitaxy on a MgO(111)
substrate. Unlike previous studies that involved Pt overlayers on hematite, the
present hematite films were grown on a stable Pt buffer layer and displayed
structural changes as a function of thickness. These structural differences
(the presence of a ferrimagnetic phase in the thinner film) significantly
affected the magnetotransport properties of the bilayers. We observed a sign
change of the SMR from positive to negative when the thickness of hematite
increased from 6 nm to 15 nm. For $\alpha$-Fe$_2$O$_3$(15 nm)/Pt, we
demonstrated room-temperature switching of the N\'eel order with rectangular,
nondecaying switching characteristics. Such structures open the way to
extending magnetotransport studies to more complex systems with double
asymmetric metal/hematite/Pt interfaces.",2306.07149v1
2023-06-25,Electric-power efficiency of anomalous Hall current,"The electric-power dissipation of the anomalous-Hall current injected into a
lateral load circuit is studied. The anomalous-Hall current is generated by a
$\mathrm{Co_{75}Gd_{25}}$ ferrimagnetic Hall bar and injected into lateral
contacts lithographied at the two edges. The current, the voltage and the power
injected in the lateral circuit are studied as a function of the magnetization
state, the load resistance $R_l$, and the temperature. The power efficiency
shows a sharp maximum as a function $R_l$, which corresponds to the condition
of the resistance matching of the two sub-circuits. The maximum power
efficiency is of the order of the square of anomalous-Hall angle. The
observations are in agreement with recent predictions based on a
non-equilibrium variational approach.",2306.14226v2
2023-06-26,Origin of magnetic ordering in half-Heusler RuMnGa,"The half-Heusler alloy RuMnGa having valence electron count (VEC) 18 has
recently been theoretically proposed to exhibit compensated ferrimagnetic
(CFiM) character instead of the expected nonmagnetic ground state. On the other
hand, a preliminary experimental study proposed ferromagnetic (FM) ordering. As
no half-Heusler system with VEC 18 is known to exhibit magnetic ordering, we
have investigated the details of crystal structure and magnetic properties of
RuMnGa using a combination of experimental tools, viz., x-ray and neutron
diffraction techniques, dc and ac susceptibility, isothermal magnetisation,
heat capacity, resistivity and neutron depolarisation measurements. Rietveld
refinements of x-ray and neutron diffraction data suggest single phase nature
of the compound with elemental composition RuMn$_{0.86}$Ga$_{1.14}$. We have
shown that the system exhibits FM-type ordering owing to the inherent presence
of this minor off-stoichiometry, showing very low magnetic moment. The system
also exhibits reentrant canonical spin-glass behaviour, which is rarely
observed in half-Heusler alloys. The temperature coefficient of resistivity
changes its sign from negative to positive and further to negative as the
temperature decreases.",2306.14836v1
2023-06-29,Broken-symmetry magnetic phases in two-dimensional triangulene crystals,"We provide a comprehensive theory of magnetic phases in two-dimensional
triangulene crystals, using both Hubbard model and density functional theory
(DFT) calculations. We consider centrosymmetric and non-centrosymmetric
triangulene crystals. In all cases, DFT and mean-field Hubbard model predict
the emergence of broken-symmetry antiferromagnetic (ferrimagnetic) phases for
the centrosymmetric (non-centrosymmetric) crystals. This includes the special
case of the [4,4]triangulene crystal, whose non-interacting energy bands
feature a gap with flat valence and conduction bands. We show how the lack of
contrast between the local density of states of these bands, recently measured
via scanning tunneling spectroscopy, is a natural consequence of a
broken-symmetry N\'eel state that blocks intermolecular hybridization. Using
random phase approximation, we also compute the spin wave spectrum of these
crystals, including the recently synthesized [4,4]triangulene crystal. The
results are in excellent agreement with the predictions of a Heisenberg spin
model derived from multi-configuration calculations for the unit cell. We
conclude that experimental results are compatible with an antiferromagnetically
ordered phase where each triangulene retains the spin predicted for the
isolated species.",2306.17153v1
2023-07-14,Signature of geometry modulation on interface magnetism emerged in isomeric IrO2-CoFe2O4 heterostructures,"The interface composed of magnets and strong spin-orbit coupling (SOC)
materials forms an important platform for spintronic devices and intriguing
magnetic phenomena, such as the chiral spin textures and magnetic proximity
effect (MPE). The interface exchange interaction and Dzyaloshinskii-Moriya
interaction (DMI) have been discussed in a wide range of heterostructures,
while the crystal stacking geometry modulation on these interface interactions
has rarely been considered. Here, we show a pronounced geometry modulation on
the interface magnetism through comparing a rutile and an anatase IrO2 capping
on a ferrimagnetic CoFe2O4. The rutile heterostructure with a high-symmetry
interface shows a conventional anomalous Hall effect (AHE) profile due to the
MPE. In contrast, the anatase one with a low-symmetry interface exhibits a
topological-like AHE even at zero-field, suggesting the emergence of
non-coplanar magnetic order at the interface. Our results suggest that the
influence of DMI at the interface can be more accentuated by forming a
low-symmetry interface and raises a new means of designing interface magnetism
via the geometry modulation.",2307.07169v2
2023-07-21,Magnetism and topological property in icosahedral quasicrystal,"Quasicrystal (QC) has no periodicity but has a unique rotational symmetry
forbidden in periodic crystals. Lack of microscopic theory of the crystalline
electric field (CEF) in the QC and approximant crystal (AC) has prevented us
from understanding the electric property, especially the magnetism. By
developing the general formulation of the CEF in the rare-earth based QC and
AC, we have analyzed the CEF in the QC Au-SM-Tb and AC (SM=Si, Ge, and Ga). The
magnetic anisotropy arising from the CEF plays an important role in realizing
unique magnetic states on the icosahedron (IC). By constructing the minimal
model with the magnetic anisotropy, we have analyzed the ground-state
properties of the IC, 1/1 AC, and QC. The hedgehog state is characterized by
the topological charge of one and the whirling-moment state is characterized by
the topological charge of three. The uniform arrangement of the ferrimagnetic
state is stabilized in the QC with the ferromagnetic (FM) interaction, which is
a candidate for the magnetic structure recently observed FM long-range order in
the QC Au-Ga-Tb. The uniform arrangement of the hedgehog state is stabilized in
the QC with the antiferromagnetic interaction, which suggests the possibility
of the topological magnetic long-range order.",2307.11898v1
2023-08-07,Frustration relief and reorientation transition in the kagome-like dolerophanite Cu$_2$OSO$_4$,"We present a theoretical study of dolerophanite Cu$_2$OSO$_4$, a layered
kagome-like spin-$\frac{1}{2}$ magnetic insulator that can be described either
as a system of chains coupled through dimers or as a kagome lattice where every
third spin is replaced by a ferromagnetic spin dimer. Building on insights from
ab initio calculations, classical numerical minimizations, and semiclassical
expansions, we arrive at a minimal microscopic description that accounts for
the experimental data reported so far, including the nature of the magnetic
order, the reported spin length, and the observed anisotropy. The latter arises
by a peculiar competition between the antisymmetric (Dzyaloshinskii-Moriya) and
the symmetric part of the exchange anisotropy, which gives rise to a two-step
re-orientation process involving two successive continuous phase transitions.
Our work uncovers mechanisms stabilizing canted ferrimagnetic order in kagome
systems, and highlights strong magnetic anisotropy in the presence if
dissimilar magnetic orbitals on crystallographically nonequivalent Cu sites. We
also show how these anisotropy terms affect the spin-wave spectrum and how they
can be tracked experimentally.",2308.03599v2
2023-08-16,Growth of millimeter-sized high-quality CuFeSe$_2$ single crystals by the molten salt method and study of their semiconducting behavior,"An eutectic AlCl$_3$/KCl molten salt method in a horizontal configuration was
employed to grow millimeter-sized and composition homogeneous CuFeSe$_2$ single
crystals due to the continuous growth process in a temperature gradient induced
solution convection. The typical as-grown CuFeSe$_2$ single crystals in cubic
forms are nearly 1.6$\times$1.2$\times$1.0 mm3 in size. The chemical
composition and homogeneity of the crystals was examined by both inductively
coupled plasma atomic emission spectroscopy and energy dispersive spectrometer
with Cu:Fe:Se = 0.96:1.00:1.99 consistent with the stoichiometric composition
of CuFeSe$_2$. The magnetic measurements suggest a ferrimagnetic or weak
ferromagnetic transition below T$_C$ = 146 K and the resistivity reveals a
semiconducting behavior and an abrupt increase below T$_C$.",2308.08223v1
2023-08-17,Magnetic Order in A Quenched-High-Temperature-Phase of Cu-Doped MnBi,"Permanent magnets are of great importance due to their vast applications.
MnBi has been proposed to be a potential permanent magnet that can be widely
used while past efforts have been focused on optimizing the ferromagnetic
low-temperature phase of MnBi. Herein, we report a series of new materials,
CuxMn1-xBi, crystallizing in a quenched high-temperature-phase (QHTP)
MnBi-related structure. We synthesized single crystals of CuxMn1-xBi and found
that they crystallize in an unreported trigonal structure (P -31c). Magnetic
properties measurements imply high-temperature antiferromagnetic (AFM) ordering
and low-temperature ferromagnetic or ferrimagnetic (FM/FiM) ordering. By
analyzing the doping effect on crystal structure and magnetic properties, we
established a magnetic phase diagram for Cu-doped MnBi and attributed the AFM
and FM/FiM to two different atomic sites of Mn.",2308.08952v2
2023-08-17,Characterization of the Magnetocaloric Effect in RMn6Sn6 including High Entropy Alloys,"We present a comprehensive study of the magnetocaloric effect (MCE) in a
family of kagome magnets with formula RMn6Sn6 (R=Tb, Ho, Er, and Lu). These
materials have a small rare-earth content and tunable magnetic ordering, hence
they provide a venue to study the fundamentals of the MCE. We examine the
effect of different types of order (ferrimagnetic and antiferromagnetic) and
the presence of a metamagnetic transition on the MCE. We extend the study to
high-entropy rare-earth alloys of the family. Our results suggest several
guidelines for enhancing the MCE in tunable magnetic materials with a small
rare-earth content.",2308.09161v2
2023-09-19,Chiral Skyrmions Interacting with Chiral Flowers,"The chiral nature of active matter plays an important role in the dynamics of
active matter interacting with chiral structures. Skyrmions are chiral objects,
and their interactions with chiral nanostructures can lead to intriguing
phenomena. Here, we explore the random-walk dynamics of a thermally activated
chiral skyrmion interacting with a chiral flower-like obstacle in a
ferromagnetic layer, which could create topology-dependent outcomes. It is a
spontaneous mesoscopic order-from-disorder phenomenon driven by the thermal
fluctuations and topological nature of skyrmions that exists only in
ferromagnetic and ferrimagnetic systems. The interactions between the skyrmions
and chiral flowers at finite temperatures can be utilized to control the
skyrmion position and distribution without applying any external driving force
or temperature gradient. The phenomenon that thermally activated skyrmions are
dynamically coupled to chiral flowers may provide a new way to design
topological sorting devices.",2309.10338v2
2023-10-11,The Fractal-Lattice Hubbard Model,"Here, we investigate the fractal-lattice Hubbard model using various
numerical methods: exact diagonalization, the self-consistent diagonalization
of a (mean-field) Hartree-Fock Hamiltonian and state-of-the-art Auxiliary-Field
Quantum Monte Carlo. We focus on the Sierpinski triangle with Hausdorff
dimension $1.58$ and consider several generations. In the tight-binding limit,
we find compact localised states, which are also explained in terms of symmetry
and linked to the formation of a ferrimagnetic phase at weak interaction.
Simulations at half-filling revealed the persistence of this type of magnetic
order for every value of interaction strength and a Mott transition for U/t
$\sim$ 4.5. In addition, we found a remarkable dependence on the Hausdorff
dimension regarding $i)$ the number of compact localised states in different
generations, $ii)$ the scaling of the total many-body ground-state energy in
the tight-binding limit, and $iii)$ the density of the states at the corners of
the lattice for specific values of electronic filling. Moreover, in the
presence of an intrinsic spin-orbit coupling, the zero-energy compact localized
states become entangled and give rise to inner and outer corner modes.",2310.07813v1
2023-10-24,Characterisation of ferroelectric domains in magnetite (Fe3O4),"Magnetite has long been investigated across many disciplines due to the
interplay between its ferroic order parameters, namely its ferrimagnetism,
ferroelasticity and ferroelectricty. Despite this, the experimental difficulty
in measuring low temperature real space images of the ferroelectric domains has
meant that the local behaviour of ferroelectric domains emergent below the 38 K
phase transition have yet to be realised. This work presents real space images
of the ferroelectric domains, and uses piezo force microscopy to, as a function
of temperature, probe the onset of piezoelectricty and ferroelectricity across
the 38 K transition",2310.15891v1
2023-10-30,Plasma treatment as an unconventional molecular magnet engineering method,"Molecular magnetism aims to design materials with unique properties at the
molecular level, focusing on the systematic synthesis of new chemical
compounds. In this paper, we propose an alternative route to engineer molecular
magnetic materials through plasma irradiation. Our research indicates that the
long-range magnetic order temperature in the three-dimensional
$\mathrm{\{[Mn^{II}(H_2O)_2]_2[Nb^{IV}(CN)_8]\cdot 4H_2O\}_n}$ molecular
ferrimagnet increases by 20 K after plasma treatment. The core structure of the
compound does not reveal significant changes after plasma processing, as
confirmed by the X-ray powder diffraction analysis. The observed results are
attributed to the release of crystallized water molecules. The described
procedure can serve as a viable approach to altering the magnetic properties of
the molecular systems.",2310.19467v1
2023-11-01,Giant anomalous Hall effect in epitaxial Mn$_{3.2}$Ge films with a cubic kagome structure,"We report on the first example of epitaxial Mn$_{3 + \delta}$Ge thin films
with a cubic $L1_2$ structure. The films are found to exhibit frustrated
ferromagnetism with an average magnetization corresponding to
0.98$~\pm~$0.06$~\mu_B$/Mn, far larger than the parasitic ferromagnetism in
hexagonal Mn$_3$Ge and the partially compensated ferrimagnetism in tetragonal
Mn$_3$Ge. The Hall conductivity is the largest reported for the kagome magnets
with a low temperature value of $\sigma_{xy} = 1587~$S/cm. Density functional
calculations predict that a chiral antiferromagnetic structure is lower in
energy than a ferromagnetic configuration in an ordered stoichiometric crystal.
However, chemical disorder driven by the excess Mn in our films explains why a
frustrated 120$^\circ$ spin structure is not observed. Comparisons between the
magnetization and the Hall resistivity indicate that a non-coplanar spin
structure contributes the Hall signal. Anisotropic magnetoresistance and planar
Hall effect with hysteresis up to 14 T provides further insights into this
material.",2311.00683v1
2023-12-09,Magnetic properties of ferro-antiferromagnetic spin triangle chain,"We study the frustrated spin-$\frac{1}{2}$ model consisting of a linear chain
of triangles with ferro (F)- and antiferromagnetic (AF) interactions connected
by ferromagnetic interactions (triangles chain). The ground state phase diagram
as a function of the frustration parameter (a ratio of F and AF interactions)
and the interaction between triangles consists of the ferromagnetic, two
ferrimagnetic and the singlet phases. We study the magnetic properties in these
phases and analyze the magnetization curves. We show that there are the
magnetization plateau in the singlet phase and the magnetization jumps in some
region of this phase. We study the low-thermodynamics and its relation to the
specific structure of the excitation spectrum of the triangle chain.",2312.05544v1
2023-12-19,Macroscopic entanglement between ferrimagnetic magnons and atoms via crossed optical cavity,"We consider a two-dimensional opto-magnomechanical (OMM) system including two
optical cavity modes, a magnon mode, a phonon mode, and a collection of
two-level atoms. In this study, we demonstrate the methodology for generating
stationary entanglement between two-level atoms and magnons, which are
implemented using two optical cavities inside the setup. Additionally, we
investigate the efficiency of transforming entanglement from atom-phonon
entanglement to atom-magnon entanglement. The magnons are stimulated by both a
bias magnetic field and a microwave magnetic field, and they interact with
phonons through the mechanism of magnetostrictive interaction. This interaction
generates magnomechanical displacement, which couples to an optical cavity via
radiation pressure. We demonstrate that by carefully selecting the frequency
detuning of an optical cavity, it is possible to achieve an increase in
bipartite entanglements. Furthermore, this improvement is found to be resistant
to changes in temperature. The entanglement between atoms and magnons plays a
crucial role in the construction of hybrid quantum networks. Our modeling
approach exhibits potential applications in the field of magneto-optical trap
systems as well.",2312.11864v1
2023-12-20,Spin wave confinement in hybrid superconductor-ferrimagnet nanostructure,"Eddy currents in a superconductor shield the magnetic field in its interior
and are responsible for the formation of a magnetic stray field outside of the
superconducting structure. The stray field can be controlled by the external
magnetic field and affect the magnetization dynamics in the magnetic system
placed in its range. In the case of a hybrid system consisting of a
superconducting strip placed over a magnetic layer, we predict theoretically
the confinement of spin waves in the well of the static stray field. The number
of bound states and their frequencies can be controlled by an external magnetic
field. We have presented the results of semi-analytical calculations
complemented by numerical modeling.",2312.13029v1
2023-12-29,Spin-orbit torques and magnetization switching in Gd/Fe multilayers generated by current injection in NiCu alloys,"Light transition metals have recently emerged as a sustainable material class
for efficient spin-charge interconversion. We report measurements of
current-induced spin-orbit torques generated by Ni$_{1-x}$Cu$_{x}$ alloys in
perpendicularly magnetized ferrimagnetic Gd/Fe multilayers. We show that the
spin-orbit torque efficiency of Ni$_{1-x}$Cu$_{x}$ increases with the Ni/Cu
atomic ratio, reaching values comparable to those of Pt for Ni$_{55}$Cu$_{45}$.
Furthermore, we demonstrate magnetization switching of a 20-nm-thick Gd/Fe
multilayer with a threshold current that decreases with increasing Ni
concentration, similar to the spin-orbit torque efficiency. Our findings show
that Ni$_{1-x}$Cu$_{x}$$-$based magnetic heterostructures allow for efficient
control of the magnetization by electric currents.",2312.17652v1
2024-01-06,Cavity magnonics with domain walls in insulating ferromagnetic wires,"Magnetic domain walls (DWs) are topological defects that exhibit robust
low-energy modes that can be harnessed for classical and neuromorphic
computing. However, the quantum nature of these modes has been elusive thus
far. Using the language of cavity optomechanics, we show how to exploit a
geometric Berry-phase interaction between the localized DWs and the extended
magnons in short ferromagnetic insulating wires to efficiently cool the DW to
its quantum ground state or to prepare nonclassical states exhibiting a
negative Wigner function that can be extracted from the power spectrum of the
emitted magnons. Moreover, we demonstrate that magnons can mediate long-range
entangling interactions between qubits stored in distant DWs, which could
facilitate the implementation of a universal set of quantum gates. Our proposal
relies only on the intrinsic degrees of freedom of the ferromagnet, and can be
naturally extended to explore the quantum dynamics of DWs in ferrimagnets and
antiferromagnets, as well as quantum vortices or skyrmions confined in
insulating magnetic nanodisks.",2401.03164v1
2024-01-10,Field-free ultrafast magnetization reversal of a nanodevice by a chirped current pulse via spin-orbit torque,"We investigated the magnetization reversal of a perpendicularly magnetized
nanodevice using a chirped current pulse (CCP) via spin-orbit torques (SOT).
Our findings demonstrate that both the field-like (FL) and damping-like (DL)
components of SOT in CCP can efficiently induce ultrafast magnetization
reversal without any symmetry-breaking means. For a wide frequency range of the
CCP, the minimal current density obtained is significantly smaller compared to
the current density of conventional SOT-reversal. This ultrafast reversal is
due to the CCP triggering enhanced energy absorption (emission) of the
magnetization from (to) the FL- and DL-components of SOT before (after)
crossing over the energy barrier. We also verified the robustness of the
CCP-driven magnetization reversal at room temperature. Moreover, this strategy
can be extended to switch the magnetic states of perpendicular synthetic
antiferromagnetic (SAF) and ferrimagnetic (SFi) nanodevices. Therefore, these
studies enrich the basic understanding of field-free SOT-reversal and provide a
novel way to realize ultrafast SOT-MRAM devices with various free layer
designs: ferromagnetic, SAF, and SFi.",2401.04882v2
2024-01-15,Calculating Magnetic Properties of Two-Dimensional Materials for Memory Applications,"Calculating magnetic properties of two-dimensional materials is crucial for
implementing memory devices (like USB drive, RAM, hard disk drive of computers)
having reduced size. Two dimensional materials can be implemented as a thin
film which can reduce the size of memory devices. These materials as well as
devices made with magnetic two-dimensional materials are of current research
interest in industry and academia. From the materials project database, crystal
structure file of 30 two dimensional materials have been downloaded to
calculate their magnetic properties. BURAI Quantum espresso software has been
used to extract magnetic properties of 30 two dimensional (2D) materials. These
30 materials have magnetic Fe, Ni, Co, Mn, and Cr atoms in their molecular
structure. Magnetic materials play a key and vital role in today's modern-day
technology. There are five different types of magnetic materials. The
classification magnetic materials are diamagnetism, paramagnetic,
ferromagnetism, ferrimagnetism, and anti-ferromagnetism. Total energy of
different magnetic configurations has been calculated to find the most stable
magnetic configurations of these materials.",2401.07980v1
2024-01-22,Generating magnon Bell states via parity measurement,"We propose a scheme to entangle two magnon modes based on parity measurement.
In particular, we consider a system that two yttrium-iron-garnet spheres are
coupled to a $V$-type superconducting qutrit through the indirect interactions
mediated by cavity modes. An effective parity-measurement operator that can
project the two macroscopic spin systems to the desired subspace emerges when
the ancillary qutrit is projected to the ground state. Consequently,
conventional and multi-excitation magnon Bell states can be generated from any
separable states with a nonvanishing population in the desired subspace. The
target state can be distilled with a near-to-unit fidelity only by several
rounds of measurements and can be stabilized in the presence of decoherence. In
addition, a single-shot version of our scheme is obtained by shaping the
detuning in the time domain. Our scheme that does not rely on any nonlinear
effect brings insight to the entangled-state generation in massive
ferrimagnetic materials via quantum measurement.",2401.11684v1
2024-01-29,Competing magnetic states on the surface of multilayer ABC-stacked graphene,"We study interaction-mediated magnetism on the surface of ABC-multilayer
graphene driven by its zero-energy topological flat bands. Using the
random-phase approximation we treat onsite Hubbard repulsion and find multiple
competing magnetic states, due to both intra- and inter-valley scattering, with
the latter causing an enlarged magnetic unit cell. At half-filling and when the
Hubbard repulsion is weak, we observe two different ferromagnetic orders. Once
the Hubbard repulsion becomes more realistic, new ferrimagnetic orders arise
with distinct incommensurate intra- or inter-valley scattering vectors
depending on interaction strength and doping, leading to a multitude of
competing magnetic states.",2401.16345v1
2024-01-20,Maximizing bipolar sensitivity for anomalous Nernst thermopiles in heat flux sensing in amorphous GdCo alloys,"A Heat Flux Sensor (HFS) facilitates the visualization of heat flow, unlike a
temperature sensor, and is anticipated to be a key technology in managing waste
heat. Commercialized HFS devices, which are based on the Seebeck effect, are
notably expensive due to fabrication challenges and the need for sensitive
calibration. Recently, an HFS utilizing the Anomalous Nernst Effect (ANE) has
been proposed as a solution to these issues, garnering significant interest in
enhancing the transverse Seebeck coefficient. However, ideal materials for HFS
not only require a large transverse Seebeck coefficient but also meet several
criteria including low thermal conductivity and a bipolar nature of the
transverse Seebeck coefficient. In this study, we have investigated ANE in
amorphous ferrimagnetic GdCo alloys, revealing their numerous advantages as HFS
materials. These include unparalleled sensitivity comparable to Co2MnGa, the
ability to exhibit both positive and negative ANE, versatility for deposition
on various substrates, and a small longitudinal Seebeck coefficient. These
qualities position GdCo films as promising candidates for the advancement of
ANE-based HFS technology.",2402.04259v1
2024-02-08,Modulation of magnetization in BiFeO$_3$ using circularly polarized light,"BiFeO$_3$ is a multiferroic material featuring ferroelectricity and
noncollinear antiferromagnetism, the latter manifested as a cycloid of spin
density. Definitive and efficient control of the characteristic spin texture of
BiFeO$_3$ is attractive for emerging quantum devices. In this regard,
crystal-field $d\rightarrow d$ excitations localized on Fe atomic sites in
BiFeO$_3$ provide an avenue for manipulation of the spin texture as they induce
a complex interplay among the spin, charge, and lattice degrees of freedom. In
this work, the ab initio GW-BSE method is used to characterize these
excitations within an excitonic picture. We find that the $d-d$ transitions
appear as strongly bound, chiral, spin-flip excitons deep within the electronic
band gap as a result of the intricate competition between the lattice
potential, the antiferromagnetic ordering, the spin-orbit coupling, and the
electron-hole interaction. Most crucially, these excitons are composed of
electron-hole pairs with opposite spins that constitute almost all of their
$\pm \hbar$ total angular momentum. These excitons of specific angular momentum
can be selectively excited using circularly polarized light, consequently
modulating the local magnetic moment giving rise to transient ferrimagnetism.",2402.05430v2
2024-02-15,Explaining all-optical switching in ferrimagnets with heavy rare-earth elements by varying the spin-flip scattering probability of Gd in Co$_x$Gd$_{100-x}$ alloys and Co/Gd bilayers,"Using the microscopic three temperature model, we simulate single-pulse
all-optical switching (AOS) in alloys and bilayers consisting of Co and Gd. In
particular, we investigate its dependence on the spin-flip probability of Gd
$a_\mathrm{sf,Gd}$, a material parameter describing the strength of spin-phonon
coupling. We do so to elucidate the mechanisms behind all-optical switching in
systems where Co is coupled to heavy rare-earth elements with higher damping
such as Tb. In alloys, our observations are twofold. First, an increase of
$a_\mathrm{sf,Gd}$ leads to a broadening of the range of compositions for which
AOS is observed. Second, the ideal Co content is decreased as
$a_\mathrm{sf,Gd}$ is varied. For bilayers, our analysis indicates that
switching is most efficient when $a_\mathrm{sf,Gd}$ takes on small values.
Conversely, increasing the value of $a_\mathrm{sf,Gd}$ leads to a general
suppression of AOS. Comparing alloys to bilayers, we find that AOS in alloys
exhibits greater resilience to variations in $a_\mathrm{sf,Gd}$ than it does in
bilayers.",2402.09878v1
2024-02-20,Magnetic transitions of biphenylene network layers induced by external perturbations,"We present a comprehensive investigation of the magnetic ordering in
biphenylene network (BPN) layers, employing density functional theory (DFT)
calculations under external perturbations, including uniaxial strains and hole
doping. We compute fully relaxed structures, energy bands, and magnetic states
by performing DFT calculations augmented with extended Hubbard interactions,
encompassing both on-site and inter-site interactions, to accurately capture
electron correlations. We emphasize the importance of the extended Hubbard
forces by contrasting BPN layers with and without the forces. Our results
reveal that in their fully relaxed structures, both BPN monolayer and bilayer
are non-magnetic. We exploit external perturbations to induce magnetic
ordering. The application of uniaxial strains induces magnetic phase
transitions, leading to ferrimagnetic and antiferromagnetic states in BPN
monolayer and bilayer, respectively. Additionally, we investigate hole doping
as an alternative mechanism for inducing magnetic transitions. Our findings
shed light on the tunability of magnetic properties in BPN layers through
external perturbations, demonstrating the promise of low-dimensional materials
in future spintronics and nanoelectronic applications.",2402.13129v1
2024-02-27,"Novel Ternary AgIICoIIIF5 Fluoride: Synthesis, Structure and Magnetic Characteristics","We present a new compound in the silver cobalt fluoride system, featuring
paramagnetic silver (d9) and high-spin cobalt (d6), synthesized by solid state
method in an autoclave under F2 overpressure. Based on powder X ray
diffraction, we determined that AgIICoIIIF5 crystallizes in a monoclinic system
with space group C2/c. The calculated fundamental band gap falls in the visible
range of the electromagnetic spectrum, and the compound has the character of
charge-transfer insulator. AgCoF5 is a ferrimagnet with one predominant
superexchange magnetic interaction constant between mixed spin cations (Ag ...
Co) of minus 62 meV (SCAN result). Magnetometric measurements conducted on a
powdered sample allowed the identification of a transition at 128 K, which
could indicate magnetic ordering.",2402.17399v1
2024-02-28,Plasma-induced magnetic phase in 3D $\mathrm{Mn^{II}-Nb^{IV}}$ octacyanidometalate with magnetic sponge behavior,"A new magnetic phase with $T_C = 72 \ \mathrm K$ was obtained by exposing the
three-dimensional $\mathrm{\{ [Mn^{II}(H_2O)_2]_2[Nb^{IV}(CN)_8] \cdot 4H_2O \}
_n}$ coordination ferrimagnet ($T_C = 49 \ \mathrm K$) to air, oxygen,
nitrogen, and argon-based plasma. The X-ray powder diffraction pattern revealed
that the unit cell shrank after plasma treatment, leading to a 20% enhancement
of the superexchange couplings, as estimated from the mean-field approximation
(MFA) model. Although no stable dehydrated form was found in the
thermogravimetric analysis, the observed changes are attributed to the removal
of crystallization water molecules. The plasma-induced magnetic phase could not
be obtained by exposing the studied material to 0% relative humidity during
dynamic vapor sorption. Instead, the material underwent a major structural
reorganization after dehydration, necessitating an extended MFA model to
reproduce the magnetic susceptibility. These findings demonstrate that
plasma-induced changes can create unique magnetic phases in molecule-based
systems that are otherwise unobtainable.",2402.18195v1
2024-03-12,Magnetic Phase Diagram and Skyrmions of the Hubbard Model on the Beta-Mn Type Lattice,"Magnetic phase diagram for the Hubbard model on the Beta-Mn type lattice has
been calculated as a function of the Coulomb interaction energy parameter U and
the electron number per atom n by using the generalized Hartree-Fock
approximation combined with the recursion method for electronic-structure
calculations. The ferromagnetic state, the ferrimagnetic state, and the
helimagnetic state as well as the 3Q multiple spin density waves (3QMSDW)
states have been obtained on the U-n plane. Their detailed structures are
examined with use of the Fourier analysis. It is shown that the calculated
phase diagram and the Dzyaloshinskii-Moriya interaction elucidate the magnetic
interactions for the itinerant-electron skyrmions in transition metal alloys
and compounds on the Beta-Mn type lattice.",2403.07443v1
2024-04-02,Understanding spin currents from magnon dispersion and polarization: Spin-Seebeck effect and neutron scattering study on Tb3Fe5O12,"Magnon spin currents in the ferrimagnetic garnet Tb3Fe5O12 with 4f electrons
were examined through the spin-Seebeck effect and neutron scattering
measurements. The compound shows a magnetic compensation, where the
spin-Seebeck signal reverses above and below Tcomp = 249.5(4) K. Unpolarized
neutron scattering unveils two major magnon branches with finite energy gaps,
which are well-explained in the framework of spin-wave theory. Their
temperature dependencies and the direction of the precession motion of magnetic
moments, i.e. magnon polarization, defined using polarized neutrons, explain
the reversal at Tcomp and decay of the spin-Seebeck signals at low
temperatures. We illustrate an example that momentum- and energy-resolved
microscopic information is a prerequisite to understanding the magnon spin
current.",2404.01603v1
2024-04-02,Field-induced spin polarization in lightly Cr-substituted layered antiferromagnet NiPS3,"Tuning magnetic properties in layered magnets is an important route to
realize novel phenomenon related to two-dimensional (2D) magnetism. Recently,
tuning antiferromagnetic (AFM) properties through substitution and
intercalation techniques have been widely studied in MPX3 compounds.
Interesting phenomena, such as diverse AFM structures and even the signatures
of ferrimagnetism, have been reported. However, long-range ferromagnetic (FM)
ordering has remained elusive. In this work, we explored the magnetic
properties of the previously unreported Cr-substituted NiPS3. We found that Cr
substitution is extremely efficient in controlling spin orientation in NiPS3.
Our study reveals a field-induced spin polarization in lightly (9%)
Cr-substituted NiPS3, which is likely attributed to the attenuation of AFM
interactions and magnetic anisotropy due to Cr doping. Our work provides a
possible strategy to achieve FM phase in AFM MPX3, which could be useful for
investigating 2D magnetism as well as potential device applications.",2404.02091v1
2002-02-25,Eccentricity Evolution for Planets in Gaseous Disks,"We investigate the hypothesis that interactions between a giant planet and
the disk from which it forms promote eccentricity growth. These interactions
are concentrated at discrete Lindblad and corotation resonances. Interactions
at principal Lindblad resonances cause the planet's orbit to migrate and open a
gap in the disk if the planet is sufficiently massive. Those at first order
Lindblad and corotation resonances change the planet's orbital eccentricity.
Eccentricity is excited by interactions at external Lindblad resonances which
are located on the opposite side of corotation from the planet, and damped by
co-orbital Lindblad resonances which overlap the planet's orbit. If the planet
clears a gap in the disk, the rate of eccentricity damping by co-orbital
Lindblad resonances is reduced. Density gradients associated with the gap
activate eccentricity damping by corotation resonances at a rate which
initially marginally exceeds that of eccentricity excitation by external
Lindblad resonances. But the corotation torque drives a mass flux which reduces
the density gradient near the resonance. Sufficient partial saturation of
corotation resonances can tip the balance in favor of eccentricity excitation.
A minimal initial eccentricity of a few percent is required to overcome viscous
diffusion which acts to unsaturate corotation resonances by reestablishing the
large scale density gradient. Thus eccentricity growth is a finite amplitude
instability. Formally, interactions at the apsidal resonance, which is a
special kind of co-orbital Lindblad resonance, appears to damp eccentricity
faster than external Lindblad resonances can excite it. However, apsidal waves
have such long wavelengths that they do not propagate in protoplanetary disks.
This reduces eccentricity damping by the apsidal resonance to a modest level.",0202462v1
2020-12-16,Non-Invasive Near-field Spectroscopy of Single Sub-Wavelength Complementary Resonators,"Subwavelength metallic resonators provide a route to achieving strong
light-matter coupling by means of tight confinement of resonant electromagnetic
fields. Investigation of such resonators however often presents experimental
difficulties, particularly at terahertz (THz) frequencies. A single
subwavelength resonator weakly interacts with THz beams, making it difficult to
probe it using far-field methods; whereas arrays of resonators exhibit
inter-resonator coupling, which affects the resonator spectral signature and
field confinement. Here, traditional far-field THz spectroscopy is
systematically compared with aperture-type THz near-field microscopy for
investigating complementary THz resonators. Whilst the far-field method proves
impractical for measuring single resonators, the near-field technique gives
high signal-to-noise spectral information, only achievable in the far-field
with resonator arrays. At the same time, the near-field technique allows us to
analyze single resonators - free from inter-resonator coupling present in
arrays - without significant interaction with the near-filed probe.
Furthermore, the near-field technique allows highly confined fields and surface
waves to be mapped in space and time. This information gives invaluable insight
into resonator spectral response in arrays. This near-field microscopy and
spectroscopy method enables investigations of strong light-matter coupling at
THz frequencies in the single-resonator regime.",2012.09137v1
2012-05-04,Study of Resonances for the Restricted 3-Body Problem,"Our aim is to identify and classify mean-motion resonances (MMRs) for the
coplanar circular restricted three-body problem (CR3BP) for mass ratios between
0.10 and 0.50. Our methods include the maximum Lyapunov exponent, which is used
as an indicator for the location of the resonances, the Fast Fourier Transform
(FFT) used for determining what kind of resonances are present, and the
inspection of the orbital elements to classify the periodicity. We show that
the 2:1 resonance occurs the most frequently. Among other resonances, the 3:1
resonance is the second most common, and furthermore both 3:2 and 5:3
resonances occur more often than the 4:1 resonance. Moreover, the resonances in
the coplanar CR3BP are classified based on the behaviour of the orbits. We show
that orbital stability is ensured for high values of resonance (i.e., high
ratios) where only a single resonance is present. The resonances attained are
consistent with the previously established resonances for the Solar System,
i.e., specifically, in regards to the asteroid belt. Previous work employed
digital filtering and Lyapunov characteristic exponents to determine
stochasticity of the eccentricity, which is found to be consistent with our
usage of Lyapunov exponents as an alternate approach based on varying the mass
ratio instead of the eccentricity. Our results are expected to be of principal
interest to future studies, including augmentations to observed or proposed
resonances, of extra-solar planets in binary stellar systems.",1205.0950v1
2024-02-12,Uranus's influence on Neptune's exterior mean motion resonances,"Neptune's external mean motion resonances play an important role in sculpting
the observed population of transneptunian objects (TNOs). The population of
scattering TNOs are known to 'stick' to Neptune's resonances while evolving in
semimajor axis ($a$), though simulations show that resonance sticking is less
prevalent at $a\gtrsim200-250$ au. Here we present an extensive numerical
exploration of the strengths of Neptune's resonances for scattering TNOs with
perihelion distances $q=33$ au. We show that the drop-off in resonance sticking
for the large $a$ scattering TNOs is not a generic feature of scattering
dynamics, but can instead be attributed to the specific configuration of
Neptune and Uranus in our solar system. In simulations with just Uranus removed
from the giant planet system, Neptune's resonances are strong in the scattering
population out to at least $\sim300$ au. Uranus and Neptune are near a 2:1
period ratio, and the variations in Neptune's orbit resulting from this near
resonance are responsible for destabilizing Neptune's resonances for high-$e$
TNO orbits beyond the $\sim20$:1 resonance at $a\approx220$ au. Direct
interactions between Uranus and the scattering population are responsible for
slightly weakening Neptune's closer-in resonances. In simulations where Neptune
and Uranus are placed in their mutual 2:1 resonance, we see almost no stable
libration of scattering particles in Neptune's external resonances. Our results
have important implications for how the strengths of Neptune's distant
resonances varied during the epoch of planet migration when the Neptune-Uranus
period ratio was evolving. These strength variations likely affected the
distant resonant and detached TNO populations.",2402.07824v1
2006-01-10,Fast Resonance Frequency Modulation in Superconducting Stripline Resonator,"Fast resonance frequency modulation of a superconducting stripline resonator
is investigated. The experiments are performed using a novel device which
integrates a hot electron detector (HED) into a superconducting stripline ring
resonator. Frequency modulation is demonstrated by both applying dc current or
voltage to the HED, and by applying optical illumination, with modulation
frequencies of up to 4.2GHz. Potential applications for such a device are in
telecommunication, quantum cryptography and biofluorescence.",0601190v1
2003-02-11,A classical scaling theory of quantum resonances,"The quantum resonances occurring with delta-kicked particles are studied with
the help of a fictitious classical limit, establishing a direct correspondence
between the nearly resonant quantum motion and the classical resonances of a
related system. A scaling law which characterizes the structure of the resonant
peaks is derived and numerically demonstrated.",0302018v2
2001-08-29,Resonant mesomolecule formation,"The dtm and ddm resonant fusion rates are calculated taking into account
finite resonance width and subthreshold resonances. Calculations do not use
multipole expansion of the potential. The obtained ddm resonant fusion rates
are compared with recent data at 30-360 K.",0108068v1
2005-05-10,Resonance Absorption and Regeneration in Relativistic Heavy Ion Collisions,"The regeneration of hadronic resonances is discussed for heavy ion collisions
at SPS and SIS-300 energies. The time evolutions of Delta, rho and phi
resonances are investigated. Special emphasize is put on resonance regeneration
after chemical freeze-out. The emission time spectra of experimentally
detectable resonances are explored.",0505027v1
2000-08-07,Resonance Offset Tailored Pulses for NMR Quantum Computation,"We describe novel composite pulse sequences which act as general rotors and
thus are suitable for nuclear magnetic resonance (NMR) quantum computation. The
Resonance Offset Tailoring To Enhance Nutations (ROTTEN) approach permits
perfect compensation of off-resonance errors at two selected frequencies placed
symmetrically around the frequency of the RF source.",0008034v1
2013-01-22,Stability for the inverse resonance problem for the CMV operator,"For the class of unitary CMV operators with super-exponentially decaying
Verblunsky coefficients we give a new proof of the inverse resonance problem of
reconstructing the operator from its resonances - the zeros of the Jost
function. We establish a stability result for the inverse resonance problem
that shows continuous dependence of the operator coefficients on the location
of the resonances.",1301.5078v1
2013-02-19,Resonances for 1D massless Dirac operators,"We consider the 1D massless Dirac operator on the real line with compactly
supported potentials. We study resonances as the poles of scattering matrix or
equivalently as the zeros of modified Fredholm determinant. We obtain the
following properties of the resonances: 1) asymptotics of counting function, 2)
estimates on the resonances and the forbidden domain, 3) the trace formula in
terms of resonances.",1302.4632v1
2013-06-11,An optical equilibrium in lateral waveguide-resonator optical force,"We consider the lateral optical force between resonator and waveguide, and
study the possibility of an equilibrium that occurs solely from the optical
force. We prove analytically that a single- resonance system cannot give such
an equilibrium in resonator-waveguide force. We then show that two-resonance
systems can provide such an equilibrium. We provide an intuitive way to predict
the existence of an equilibrium, and give numerical examples.",1306.2417v1
2016-04-12,PT-symmetry breaking in resonant tunneling heterostructures,"We present fermionic model based on symmetric resonant tunneling
heterostructure, which demonstrates spontaneous symmetry breaking in respect to
combined operations of space inversion (P) and time reversal (T). PT-symmetry
breaking manifests itself in resonance coalescence (collapse of resonances). We
show that resonant energies are determined by eigenvalues of auxiliary
pseudo-Hermitian PT-invariant Hamiltonian.",1604.03385v1
2016-05-06,Resonances of third order differential operators,"We consider resonances for third order ordinary differential operator with
compactly supported coefficients on the real line. Resonance are defined as
zeros of a Fredholm determinant on a non-physical sheet of three sheeted
Riemann surface. We determine upper bounds of the number of resonances in
complex discs at large radius. We express the trace formula in terms of
resonances only.",1605.01842v1
2005-07-27,Dynamics of a nanomechanical resonator coupled to a superconducting single-electron transistor,"We present an analysis of the dynamics of a nanomechanical resonator coupled
to a superconducting single electron transistor (SSET) in the vicinity of the
Josephson quasiparticle (JQP) and double Josephson quasiparticle (DJQP)
resonances. For weak coupling and wide separation of dynamical timescales, we
find that for either superconducting resonance the dynamics of the resonator is
given by a Fokker-Planck equation, i.e., the SSET behaves effectively as an
equilibrium heat bath, characterised by an effective temperature, which also
damps the resonator and renormalizes its frequency. Depending on the gate and
drain-source voltage bias points with respect to the superconducting resonance,
the SSET can also give rise to an instability in the mechanical resonator
marked by negative damping and temperature within the appropriate Fokker-Planck
equation. Furthermore, sufficiently close to a resonance, we find that the
Fokker-Planck description breaks down. We also point out that there is a close
analogy between coupling a nanomechanical resonator to a SSET in the vicinity
of the JQP resonance and Doppler cooling of atoms by means of lasers.",0507645v1
2013-04-02,Coupled Magnetic Resonator Optical Waveguides - mimicking spin waves in coupled metamaterials,"Optical resonators are important devices that control the properties of light
and manipulate light-matter interaction. Various optical resonators are
designed and fabricated using different techniques. For example, in coupled
resonator optical waveguides, light energy is transported to other resonators
through near-field coupling. In recent years, magnetic optical resonators based
on LC resonance have been realized in several metallic microstructures. Such
devices possess stronger local resonance and lower radiation loss compared with
electric optical resonators. This study provides an overall introduction on the
latest progress in coupled magnetic resonator optical waveguide (CMROW).
Various waveguides composed of different magnetic resonators are presented and
Lagrangian formalism is used to describe the CMROW. Moreover, several
interesting properties of CMROW, such as abnormal dispersions and slow light
effects, are discussed and CMROW applications in nonlinear and quantum optics
are shown. Future novel nanophotonic devices can be developed using CMROW.",1304.0573v1
2015-09-03,Quasi-Normal Mode Theory for Thermal Radiation from Lossy and Dispersive Optical Resonators,"Although optical resonators are widely used for controlling and engineering
thermal radiation, what has been lacking is a general theoretical framework to
elucidate the thermal emission of optical resonators, and guide the design and
application of thermally driven optical resonators. We developed a general and
self-consistent formalism to describe the thermal radiation from arbitrary
optical resonators made by lossy and dispersive materials like metals, with the
only assumption that the resonators have a single predominant resonance mode.
Our formalism demonstrates that the thermal emission of an optical resonator is
maximized when the mode losses to the emitter and the absorber (or far-field
background) are matched, and meanwhile the predominant resonant modes are
electrically quasi-static. By efficiently calculating the resonant modes using
the finite element methods, our formalism serves as a general principle of
designing the arbitrary optical resonator thermal emitters with perfect or
maximized emission.",1509.00939v2
2015-10-06,Multiple resonance and anti-resonance in coupled Duffing oscillators,"We investigate the resonance behaviour in a system composed by n-coupled
Duffing oscillators where only the first oscillator is driven by a periodic
force, assuming a nearest neighbour coupling. We have derived the
frequency-response equations for a system composed of two-coupled oscillators
by using a theoretical approach. Interestingly, the frequency-response curve
displays two resonance peaks and one anti-resonance. A theoretical prediction
of the response amplitudes of two oscillators closely match with the
numerically computed amplitudes. We analyse the effect of the coupling strength
on the resonance and anti-resonance frequencies and the response amplitudes at
these frequencies. For the n-coupled oscillators system, in general, there are
n-resonant peaks and (n-1) anti-resonant peaks. For large values of n, except
for the first resonance, other resonant peaks are weak due to linear damping.
The resonance behaviours observed in the n-coupled Duffing oscillators are also
realized in an electronic analog circuit simulation of the equations.
Understanding the role of coupling and system size has the potential
applications in music, structural engineering, power systems, biological
networks, electrical and electronic systems.",1510.01564v1
2018-02-25,Resonant and off-resonant microwave signal manipulation in coupled superconducting resonators,"We present an experimental demonstration as well as a theoretical model of an
integrated circuit designed for the manipulation of a microwave field down to
the single-photon level. The device is made of a superconducting resonator
coupled to a transmission line via a second frequency-tunable resonator. The
tunable resonator can be used as a tunable coupler between the fixed resonator
and the transmission line. Moreover, the manipulation of the microwave field
between the two resonators is possible. In particular, we demonstrate the
swapping of the field from one resonator to the other by pulsing the frequency
detuning between the two resonators. The behavior of the system, which
determines how the device can be operated, is analyzed as a function of one key
parameter of the system, the damping ratio of the coupled resonators. We show a
good agreement between experiments and simulations, realized by solving a set
of coupled differential equations.",1802.09034v2
2013-08-01,Asteroids in retrograde resonance with Jupiter and Saturn,"We identify a set of asteroids among Centaurs and Damocloids, that orbit
contrary to the common direction of motion in the Solar System and that enter
into resonance with Jupiter and Saturn. Their orbits have inclinations I >= 140
deg and semi-major axes a < 15 AU. Two objects are currently in retrograde
resonance with Jupiter: 2006 BZ8 in the 2/-5 resonance and 2008 SO218 in the
1/-2 resonance. One object, 2009 QY6, is currently in the 2/-3 retrograde
resonance with Saturn. These are the first examples of Solar System objects in
retrograde resonance. The present resonant configurations last for several
thousand years. Brief captures in retrograde resonance with Saturn are also
possible during the 20,000 years integration timespan, particularly in the 1/-1
resonance (2006 BZ8) and the 9/-7 resonance (1999 LE31).",1308.0216v1
2009-12-26,Theory of Combined Photoassociation and Feshbach Resonances in a Bose-Einstein Condensate,"We model combined photoassociation and Feshbach resonances in a Bose-Einstein
condensate, where the shared dissociation continuum allows for quantum
interference in losses from the condensate, as well as a dispersive-like shift
of resonance. A simple analytical model, based on the limit of weakly bound
molecules, agrees well with numerical experiments that explicitly include
dissociation to noncondensate modes. For a resonant laser and an off-resonant
magnetic field, constructive interference enables saturation of the
photoassociation rate at user-friendly intensities, at a value set by the
interparticle distance. This rate limit is larger for smaller condensate
densities and, near the Feshbach resonance, approaches the rate limit for
magnetoassociation alone. Also, we find agreement with the unitary limit--set
by the condensate size--only for a limited range of near-resonant magnetic
fields. Finally, for a resonant magnetic field and an off-resonant laser,
magnetoassociation displays similar quantum interference and a dispersive-like
shift. Unlike photoassociation, interference and the fieldshift in resonant
magnetoassociation is tunable with both laser intensity and detuning. Also, the
dispersive-like shift of the Feshbach resonance depends on the size of the
Feshbach molecule, and is a signature of non-universal physics in a strongly
interacting system.",0912.5035v1
2013-09-20,Constraining the mass and width of the $N^*(1685)$ resonance,"We have examined the existence of the $N^*(1685)$ resonance, which is
recently listed by the Particle Data Group as a one-star nucleon resonance, by
using a covariant isobar model for kaon photoproduction and assuming that the
resonance has $J^p=1/2^+$, in accordance with our previous finding. After the
inclusion of this resonance the changes in the total $\chi^2$ show two clear
minima at $M_{N^*}=1650$ and 1696 MeV, which correspond to two different
resonance states. The former corresponds to the narrow nucleon resonance found
in our previous investigation, whereas the latter corresponds to a new
resonance found as we increase the resonance width. From the latter we derive
the mass and width relation of the $N^*(1685)$ resonance. We observe that the
properties of both the $N^*(1685)$ and $N^*(1710)P_{11}$ resonances are
strongly correlated. Although the best fit of the present work yields
$M_{N^*}=1696$ MeV and $\Gamma_{N^*}=76$ MeV, the apparently small
$N^*(1710)P_{11}$ coupling constant to the $K^+\Lambda$ channel found in
previous investigations suggests that $\Gamma_{N^*}\lesssim 35$ MeV, which,
according to the mass and width relation, corresponds to $M_{N^*}\lesssim 1680$
MeV.",1309.5191v1
2014-06-26,Vibrational and Ghost-Vibrational Resonances in A Modified Chua's Circuit Model Equation,"The role of the number of breakpoints $N$ in the sawtooth form of the
characteristic function in the modified Chua's circuit model equation on
vibrational and ghost-vibrational resonances is investigated in this paper. To
observe vibrational resonance the system should be driven by two periodic
forces of frequencies $\omega$ and $\Omega$, with $\Omega\gg\omega$. Resonance
occurs at the frequency $\omega$ when the amplitude of the high-frequency force
is varied. When the system is subjected to an input signal containing
multi-frequencies which are higher-order of a certain (missing) fundamental
frequency, then a resonance at the missing fundamental frequency is induced by
the high-frequency input signal and is called ghost-vibrational resonance. In
both types of resonances, the number of resonances is $N$ and hysteresis occurs
in each resonance region. There are some similarities and differences in these
two resonance phenomena. We report in detail the influence of the role of
number of breakpoints $N$ on the features of vibrational and ghost-vibrational
resonances.",1406.6836v1
2019-09-19,Resonant Laplace-Lagrange theory for extrasolar systems in mean-motion resonance,"Extrasolar systems with planets on eccentric orbits close to or in
mean-motion resonances are common. The classical low-order resonant Hamiltonian
expansion is unfit to describe the long-term evolution of these systems. We
extend the Laplace-Lagrange secular approximation for coplanar systems with two
planets by including (near-)resonant harmonics, and realize an expansion at
high order in the eccentricities of the resonant Hamiltonian both at orders one
and two in the masses. We show that the expansion at first order in the masses
gives a qualitative good approximation of the dynamics of resonant extrasolar
systems with moderate eccentricities, while the second order is needed to
reproduce more accurately their orbital evolutions. The resonant approach is
also required to correct the secular frequencies of the motion given by the
Laplace-Lagrange secular theory in the vicinity of a mean-motion resonance. The
dynamical evolutions of four (near-)resonant extrasolar systems are discussed,
namely GJ 876 (2:1 resonance), HD 60532 (3:1), HD 108874 and GJ 3293 (close to
4:1).",1909.09462v1
2020-02-05,Resonance libration and width at arbitrary inclination,"We apply the analytical disturbing function for arbitrary inclination derived
in our previous work to characterize resonant width and libration of mean
motion resonances at arbitrary inclination obtained from direct numerical
simulations of the three-body problem. We examine the 2:1 and 3:1 inner Jupiter
and 1:2 and 1:3 outer Neptune resonances and their possible asymmetric
librations using a new analytical pendulum model of resonance that includes the
simultaneous libration of multiple arguments and their second harmonics. The
numerically-derived resonance separatrices are obtained using the Mean
Exponential Growth factor of Nearby Orbits (MEGNO chaos indicator). We find
that the analytical and numerical estimates are in agreement and that resonance
width is determined by the first few fundamental resonance modes that librate
simultaneously on the resonant timescale. Our results demonstrate that the new
pendulum model may be used to ascertain resonance width analytically, and more
generally, that the disturbing function for arbitrary inclination is a powerful
analytical tool that describes resonance dynamics of low as well as high
inclination asteroids in the solar system.",2002.01832v2
2018-03-16,Resonances in the asteroid and trans-Neptunian belts: a brief review,"Mean motion resonances play a fundamental role in the dynamics of the small
bodies of the Solar System. The last decades of the 20th century gave us a
detailed description of the dynamics as well as the process of capture of small
bodies in coplanar or small inclination resonant orbits. More recently,
semianalytical or numerical methods allowed us to explore the behavior of
resonant motions for arbitrary inclination orbits. The emerging dynamics is
very rich, including large orbital changes due to secular effects inside mean
motion resonances. The process of capture in highly inclined or retrograde
resonant orbits was addressed showing that the capture in retrograde resonances
is more efficient than in direct ones. A new terminology appeared in order to
characterize the properties of the resonances. Numerical explorations in the
transneptunian region showed the relevance and the particular dynamics of the
exterior resonances with Neptune which can account for some of the known high
perihelion orbits in the scattered disk. Moreover, several asteroids evolving
in resonance with planets other than Jupiter or Neptune were found and a large
number of asteroids in three-body resonances were identified.",1803.06245v1
2019-11-04,Fano resonance in metallic grating via strongly coupled subwavelength resonators,"We investigate the Fano resonance in grating structures by using coupled
resonators. The grating consists of a perfectly conducting slab with
periodically arranged subwavelength slit holes, where inside each period, a
pair of slits sit very close to each other. The slit holes act as resonators
and are strongly coupled. It is shown rigorously that there exist two groups of
resonances corresponding to poles of the scattering problem. One sequence of
resonances have imaginary part on the order of $\varepsilon$, where
$\varepsilon$ is the size of the slit aperture, while the other sequence have
imaginary part on the order of $\varepsilon^2$. When coupled with the incident
wave at resonant frequencies, the narrow-band resonant scattering induced by
the latter will interfere with the broader background resonant radiation
induced by the former. The interference of these two resonances generates the
Fano type transmission anomaly, which persists in the whole radiation continuum
of the grating structure as long as the slit aperture size is small compared to
the incident wavelength.",1911.01025v2
2020-06-16,On the Divergence of First Order Resonance Widths at Low Eccentricities,"Orbital resonances play an important role in the dynamics of planetary
systems. Classical theoretical analyses found in textbooks report that
libration widths of first order mean motion resonances diverge for nearly
circular orbits. Here we examine the nature of this divergence with a
non-perturbative analysis of a few first order resonances interior to a
Jupiter-mass planet. We show that a first order resonance has two branches, the
pericentric and the apocentric resonance zone. As the eccentricity approaches
zero, the centers of these zones diverge away from the nominal resonance
location but their widths shrink. We also report a novel finding of ""bridges""
between adjacent first order resonances: at low eccentricities, the apocentric
libration zone of a first order resonance smoothly connects with the
pericentric libration zone of the neighboring first order resonance. These
bridges may facilitate resonant migration across large radial distances in
planetary systems, entirely in the low eccentricity regime.",2006.09452v1
2023-03-28,Characterization of harmonic modes and parasitic resonances in multi-mode superconducting coplanar resonators,"Planar superconducting microwave transmission line resonators can be operated
at multiple harmonic resonance frequencies. This allows covering wide spectral
regimes with high sensitivity, as it is desired e.g. for cryogenic microwave
spectroscopy. A common complication of such experiments is the presence of
undesired 'spurious' additional resonances, which are due to standing waves
within the resonator substrate or housing box. Identifying the nature of
individual resonances ('designed' vs. 'spurious') can become challenging for
higher frequencies or if elements with unknown material properties are
included, as is common for microwave spectroscopy. Here we discuss various
experimental strategies to distinguish designed and spurious modes in coplanar
superconducting resonators that are operated in a broad frequency range up to
20 GHz. These strategies include tracking resonance evolution as a function of
temperature, magnetic field, and microwave power. We also demonstrate that
local modification of the resonator, by applying minute amounts of dielectric
or ESR-active materials, lead to characteristic signatures in the various
resonance modes, depending on the local strength of the electric or magnetic
microwave fields.",2303.15914v1
2023-04-06,Laboratory electron screening in nuclear resonant reactions,"Both nonresonant and resonance reaction data are subject to laboratory
electron screening effects. For nonresonant reactions, such effects are well
documented and the measured cross sections can be corrected to find the
unscreened ones. Frequently, the procedure and expression to calculate
laboratory electron screening factors for nonresonant reactions are also
applied to isolated narrow resonances, without much theoretical support or
experimental evidence. A simple model is applied to estimate electron screening
factors, lengths, and potentials for narrow resonances. The corrections to the
measured data result in an enhancement of the unscreened resonance strengths by
less than 0.2%, contrary to published narrow-resonance screening correction
factors, which predict a reduction of the unscreened strengths by up to 25%.
Unless it can be proven otherwise, it is recommended that measured strengths of
isolated narrow resonances not be corrected for laboratory electron screening.
The prospects of investigating laboratory electron screening effects by
measuring almost negligible differences in resonance strengths are not
promising. Instead, the difference of the resonance energy for the unscreened
and screened situation may be measurable. As an example, the case of the E_cm =
956-keV resonance in the 27Al(p,gamma)28Si reaction is discussed. It is also
demonstrated that the claim of a previously reported detection of a resonance
near 800 keV in the 176Lu(p,n)176}Hf reaction is incorrect.",2304.03383v1
2000-02-15,Features of first passage time density function for coherent stochastic resonance in the case of two absorbing boundaries,"Coherent stochastic resonance is explained in terms of first passage time
density functions. Scaling relation between first passage time density
functions at resonance for different lengths of the medium is obtained. A
formula for first passage time density function at resonance is derived in
terms of two universal functions, which demonstrates the universal feature of
coherent stochastic resonance. A simple approximate expression for first
passage time density function at resonance is proposed which is shown to
explain the behavior at resonance fairly accurately.",0002223v1
2004-11-10,First evidence of a strong Magneto-capacitance coupling at room temperature in integrated piezoelectric resonators,"In the vicinity of their resonance frequency, piezoelectric resonators are
highly sensitive to small perturbations. The present report is focussed on the
magnetic field as a perturbation source. First, magneto-dielectric modulation
of more than 10% is achieved at room temperature on both ferroelectric single
crystals and quartz discs. Since such piezoelectric resonators are now
available as membranes directly integrated on Silicon wafer, we have checked
the magneto-dielectric modulation in such resonators. We show here for the
first time that a moderate magnetic field of 2.104 Oersteds is able to
efficiently tune the impedance of these resonators in their resonance window.",0411265v1
2005-01-06,Observation of Bifurcations and Hysteresis in Nonlinear NbN Superconducting Microwave Resonators,"In this paper we report some extraordinary nonlinear dynamics measured in the
resonance curve of NbN superconducting stripline microwave resonators. Among
the nonlinearities observed: aburpt bifurcations in the resonance response at
relatively low input powers, asymmetric resonances, multiple jumps within the
resonance band, resonance frequency drift, frequency hysteresis, hysteresis
loops changing direction and critical coupling phenomenon. Weak links in the
NbN grain structure are hypothesized as the source of the nonlinearities.",0501114v2
2005-08-31,Dispersion management using betatron resonances in an ultracold-atom storage ring,"Specific velocities of particles circulating in a storage ring can lead to
betatron resonances at which static perturbations of the particles' orbit yield
large transverse (betatron) oscillations. We have observed betatron resonances
in an ultracold-atom storage ring by direct observation of betatron motion.
These resonances caused a near-elimination of the longitudinal dispersion of
atomic beams propagating at resonant velocities, an effect which can improve
the performance of atom interferometric devices. Both the resonant velocities
and the strength of the resonances were varied by deliberate modifications to
the storage ring.",0508765v1
2006-12-11,On geometrical scaling of split-ring and double-bar resonators at optical frequencies,"In this paper we consider the resonant frequency of split-ring resonators and
double-bar resonators used to create artificial magnetic response at terahertz
and optical frequencies. It is known that geometrical scaling of the resonant
frequency of split rings breaks down at high frequencies (in the visible) due
to electromagnetic properties of metals at those frequencies. Here we will
discuss this phenomenon in terms of equivalent inductance and capacitance of
the ring, derive an approximate formula for the resonant frequency of split
rings in the visible and show how the limiting value of the resonant frequency
of extremely small split rings and double bars depends on particle shape.",0612247v1
1997-12-11,Double giant resonances in deformed nuclei,"We report on the first microscopic study of the properties of two-phonon
giant resonances in deformed nuclei. The cross sections of the excitation of
the giant dipole and the double giant dipole resonances in relativistic heavy
ion collisions are calculated. We predict that the double giant dipole
resonance has a one-bump structure with a centroid 0.8 MeV higher than twice
energy for the single giant dipole resonance in the reaction under
consideration. The width of the double resonance equals to 1.33 of that for the
single resonance.",9712041v1
2000-08-30,Direct-decay properties of charge-exchange spin giant resonances,"An extended continuum-RPA approach is applied to describe direct-decay
properties of spin giant resonances in $^{208}$Bi and $^{90}$Nb. Partial
branching ratios for direct proton decay from these resonances are evaluated.
The branching ratio for $\gamma$-decay from the spin-dipole resonance to the
Gamow-Teller resonance (main peak) is estimated. The saturation-like behaviour
of the mean doorway-state spreading width in $^{208}$Pb is discussed in
connection with the branching ratio for direct proton decay from the
spin-monopole resonance and the Gamow-Teller strength distribution.",0008062v1
2007-04-17,Theoretical study of the accuracy limits for the optical resonance frequency measurements,"The principal limits for the accuracy of the resonance frequency measurements
set by the asymmetry of the natural resonance line shape are studied and
applied to the recent accurate frequency measurements in the two-photon 1s-2s
resonance and in the one-photon 1s-2p resonance in hydrogen atom. This limit
for 1s-2s resonance is found to be $\sim 10^{-5}$ Hz compared to the accuracy
achieved in experiment $\pm 46$ Hz. In case of deuterium atom the limit is
essentially larger: $10^{-2}$ Hz. For 1s-2p resonance the accuracy limit is
0.17 MHz while the uncertainty of the recent frequency measurement is about 6
MHz.",0704.2190v1
2008-10-14,Numerical and experimental studies of resonators with reduced resonant frequencies and small electrical sizes,"Methods on reducing resonant frequencies and electrical sizes of resonators
are reported in this paper. Theoreti-cal and numerical analysis has been used
and the results for the broadside-coupled resonators from both studies exhibit
good agreement. Initial fabrication techniques are proposed and measurement
results are compared with simulations. Further high resolution techniques have
been envisaged to enhance the performance of the resona-tors. This class of
small resonators with low resonant frequencies indicates a variety of
applications in the design of microwave devices.",0810.2490v1
2011-03-29,Ultra-Efficient Cooling of Resonators: Beating Sideband Cooling with Quantum Control,"The present state-of-the-art in cooling mechanical resonators is a version of
""sideband"" cooling. Here we present a method that uses the same configuration
as sideband cooling --- coupling the resonator to be cooled to a second
microwave (or optical) auxiliary resonator --- but will cool significantly
colder. This is achieved by varying the strength of the coupling between the
two resonators over a time on the order of the period of the mechanical
resonator. As part of our analysis, we also obtain a method for fast,
high-fidelity quantum information-transfer between resonators.",1103.5750v1
2012-07-05,Investigation of Surface Plasmon Resonance in Super-Period Gold Nanoslit Arrays,"Surface plasmon resonance in super-period metal nanoslits can be observed in
the first order diffraction as well in the zeroth order transmission. In this
paper, surface plasmon resonance modes in various super-period gold nanoslit
arrays are investigated. It is found that the surface plasmon resonance
frequencies are determined by the small period of the nanoslits in super-period
nanoslits. The number of nanoslits in the unit cell super-period and the
nanoslit width do not control the surface plasmon resonance frequencies. It is
also found that the resonance wavelength observed in the first order
diffraction reveals more accurate the real surface plasmon resonance wavelength
in the metal super-period nanoslit array device.",1207.1143v1
2012-09-25,Discontinuous design of negative index metamaterials based on mode hybridization,"An electric inductor-capacitor (ELC) resonator provides a series of
electrical resonances and a pair of ELC resonators leads to the split of each
resonance into two modes, i.e., magnetic and electric modes, corresponding to
antisymmetric and symmetric current distributions. With the meticulous design
of the ELC resonator, we can achieve a negative index metamaterial through mode
hybridization by overlapping the first electric resonance mode and the second
magnetic resonance mode. Such non-connected designs may offer opportunities to
achieve three-dimensional negative index metamaterials.",1209.5761v1
2013-04-07,Nucleon resonance production in $K^+N$ interactions,"In this work, we discuss the possibility of studying nucleon resonances in
the $K^+N$ interactions. Based on our model calculations, it is found that the
hyperon exchange plays an important role for the excitation of nucleon
resonances in the $K^+N$ interactions. Therefore, the studies on nucleon
resonance production in the $K^+N$ interactions can offer us valuable
information about the couplings of nucleon resonances with strange particles.
By selecting suitable decay channels of nucleon resonances, some reactions are
also suitable to look for missing resonances.",1304.1958v1
2015-03-31,Local resonance and Bragg bandgaps in sandwich beams containing periodically inserted resonators,"We study the low frequency wave propagation behavior of sandwich beams
containing periodically embedded internal resonators. A closed form expression
for the propagation constant is obtained using a phased array approach and
verified using finite element simulations. We show that local resonance and
Bragg bandgaps coexist in such a system and that the width of both bandgaps is
a function of resonator parameters as well as their periodicity. The
interaction between the two bandgaps is studied by varying the local resonance
frequency. We find that a single combined bandgap does not exist for this
system and that the Bragg bandgaps transition into sub-wavelength bandgaps when
the local resonance frequency is above their associated classical Bragg
frequency.",1503.09048v1
2015-08-10,Resonant transmission of light in arrays of high-index dielectric nanoparticles,"We study numerically, analytically and experimentally the resonant
transmission of light in a waveguide formed by a periodic array of high-index
dielectric nanoparticles with a side-coupled resonator. We demonstrate that a
resonator with high enough Q-factor provides the conditions for the Fano-type
interference allowing to control the resonant transmission of light. We suggest
a practical realization of this resonant effect based on the quadrupole
resonance of a dielectric particle and demonstrate it experimentally for
ceramic spheres at microwaves.",1508.02208v1
2015-11-10,Waveguide-loaded silica fibers for coupling to high-index micro-resonators,"Tapered silica fibers are often used to rapidly probe the optical properties
of micro-resonators. However, their low refractive index precludes
phase-matching when coupling to high-index micro-resonators, reducing
efficiency. Here we demonstrate efficient optical coupling from tapered fibers
to high-index micro-resonators by loading the fibers with an ancillary
adiabatic waveguide-coupler fabricated via angled-etching. We demonstrate
greatly enhanced coupling to a silicon multimode micro-resonator when compared
to coupling via the bare fiber only. Signatures of resonator optical
bistability are observed at high powers. This scheme can be applied to
resonators of any size and material, increasing the functional scope of fiber
coupling.",1511.03332v1
2010-05-04,A double scale fast algorithm for the transient evolution of a resonant tunneling diode,"The simulation of the time-dependent evolution of the resonant tunneling
diode is done by a multiscale algorithm exploiting the existence of resonant
states. After revisiting and improving the algorithm developed in [N. Ben
Abdallah, O. Pinaud, J. Comp. Phys. 213 (2006) 288-310] for the stationary
case, the time-dependent problem is dealt with. The wave function is decomposed
into a non resonant part and a resonant one. The projection method to compute
the resonant part leads to an accurate algorithm thanks to a suitable
interpolation of the non resonant one. The simulation times are largely
reduced.",1005.0444v2
2014-03-20,Equivalent Circuit Model for Thick Split Ring Resonators and Thick Spiral Resonators,"A simple theoretical model which provides circuit parameters and resonance
frequency of metallic thick resonators is presented. Two different topologies
were studied: the original Pendry's SRR and spiral resonators of two and three
turns. Theoretical computations of resonant frequencies are in good agreement
with values obtained with a commercial electromagnetic solver. The model could
be helpful for designing thick frequency selective surfaces (FSS) based on this
types of resonators, so called metasurfaces.",1403.5144v1
2017-01-30,Extracting losses from asymmetric resonances in micro-ring resonators,"Propagation losses in micro-ring resonator waveguides can be determined from
the shape of individual resonances in their transmission spectrum. The losses
are typically extracted by fitting these resonances to an idealized model that
is derived using scattering theory. Reflections caused by waveguide boundaries
or stitching errors, however, cause the resonances to become asymmetric,
resulting in poor fits and unreliable propagation loss coefficients. We derive
a model that takes reflections into account and, by performing full-wave
simulations, we show that this model accurately describes the asymmetric
resonances that result from purely linear effects, yielding accurate
propagation loss coefficients.",1701.08464v2
2017-04-10,Generation of the superposition of mesoscopic states of nano-mechanical resonator by a single two-level system,"We propose measurement based conditional generation of superposition of
motional states of nanomechanical resonator. We consider a two level quantum
mechanical system coupled with nanomechanical resonator through phonon
exchange. An interaction, which produces shifts in the state of nanomechanical
resonator depending on the state of the qubit, is realized by driving qubit
through two resonant lasers. The measurement of the state of quantum mechanical
system produces superposition states of nanomechanical resonator. We show that
the quantum interference between states in superposition may lead to arbitrary
large displacement in resonator. We also discuss decoherence of generated
states using Wigner function.",1704.02735v1
2017-04-10,Fano Resonance in a Subwavelength Mie-based Metamolecule with Split Ring Resonator,"In this letter, we report a method of symmetry-breaking in an artificial
Mie-based metamolecule. A Fano resonance with a Q factor of 96 is observed at
microwave frequencies in a structure combining a split ring resonator (SRR) and
a high-permittivity dielectric cube. Calculations indicate resonant frequency
tunability will result from altering the cube's permittivity. The asymmetric
spectrum is attributed to both constructive and destructive near-field
interactions between the two distinct resonators. Experimental data and
simulation results are in good agreement. The underlying physics is seen in
field distribution and dipole analysis. This work substantiates an approach for
the manipulation of Mie resonances which can potentially be utilized in light
modulating and sensing.",1704.02758v1
2012-01-22,Mid-range adiabatic wireless energy transfer via a mediator coil,"A technique for efficient mid-range wireless energy transfer between two
coils via a mediator coil is proposed. By varying the coil frequencies three
resonances are created: emitter-mediator (EM), mediator-receiver (MR) and
emitter-receiver (ER). If the frequency sweeps are adiabatic and such that the
ER resonance precedes the MR resonance, the energy flows sequentially along the
chain emitter-mediator-receiver. If the MR resonance precedes the ER resonance,
then the energy flows directly from the emitter to the receiver via the ER
resonance; then the losses from the mediator are suppressed. This technique is
robust to noise, resonant constraints and external interferences.",1201.4592v1
2014-06-30,Resonant activation in 2D and 3D systems driven by multi-variate Lévy noises,"Resonant activation is one of classical effects demonstrating constructive
role of noise. In resonant activation cooperative action of barrier modulation
process and noise lead to the optimal escape kinetics as measured by the mean
first passage time. Resonant activation has been observed in versatilities of
systems for various types of barrier modulation processes and noise types.
Here, we show that resonant activation is also observed in 2D and 3D systems
driven by bi-variate and tri-variate $\alpha$-stable noises. Strength of
resonant activation is sensitive to the exact value of the noise parameters. In
particular, the decrease in the stability index $\alpha$ results in the
disappearance of the resonant activation.",1406.7810v1
2015-12-08,Effects of pairing correlation on low-lying quasi-particle resonance in neutron drip-line nuclei,"We discuss effects of pairing correlation on quasi-particle resonance. We
analyze in detail how the width of low-lying quasi-particle resonance is
governed by the pairing correlation in the neutron drip-line nuclei. We
consider the 46Si + n system to discuss low-lying p wave quasi-particle
resonance. Solving the Hartree-Fock-Bogoliubov equation in the coordinate space
with scattering boundary condition, we calculate the phase shift, the elastic
cross section, the resonance width and the resonance energy. We found that the
pairing correlation has an effect to reduce the width of quasi-particle
resonance which originates from a particle-like orbit in weakly bound nuclei.",1512.02675v1
2017-06-12,Tunable coupling-induced resonance splitting in self-coupled Silicon ring cavity with robust spectral characteristics,"We propose and demonstrate a self-coupled microring resonator for resonance
splitting by mutual mode coupling of cavity mode and counter-propagating mode
in Silicon-on-Insulator platform The resonator is constructed with a
self-coupling region that can excite counter-propagating mode. We
experimentally study the effect of self-coupling on the resonance splitting,
resonance extinction, and quality-factor evolution and stability. Based on the
coupling, we achieve 72% of FSR splitting for a cavity with FSR 2.1 nm with <
5% variation in the cavity quality factor. The self-coupled resonance splitting
shows highly robust spectral characteristic that can be exploited for sensing
and optical signal processing.",1706.03810v1
2017-07-29,EIT-Enhanced Coupled-Resonance Spectroscopy,"Coupled-resonance spectroscopy has been recently reported and applied for
spectroscopic measurements and laser stabilizations. With coupled-resonance
spectroscopy, one may indirectly measure some transitions between the excited
states that are hard to be measured directly because of the lack of populations
in the excited states. An improvement of the coupled-resonance spectroscopy by
combining the technology of electromagnetically induced transparency (EIT) is
proposed. The coupled-resonance spectroscopy signal can be significantly
enhanced by EIT. Several experimental schemes have been discussed. The line
shape of the EIT-enhanced coupled-resonance spectroscopy has been
calculated.The EIT-enhanced coupled-resonance spectroscopy can be used for
simultaneously stabilizing two lasers to the same atomic source.",1707.09559v1
2019-11-29,Omni-resonant space-time wave packets,"We describe theoretically and verify experimentally a novel class of
diffraction-free pulsed optical beams that are `Omni-resonant': they have the
remarkable property of transmission through planar Fabry-Perot resonators
without spectral filtering even if their bandwidth far exceeds the cavity
resonant linewidth. Ultrashort wave packets endowed with a specific
Spatio-temporal structure couple to a \textit{single} resonant mode
independently of its linewidth. We confirm that such `space-time' Omni-resonant
wave packets retain their bandwidth (1.6~nm), Spatio-temporal profile (1.3-ps
pulse width, 4-$\mu$m beam width), and diffraction-free behavior upon
transmission through cavities with resonant linewidths of 0.3-nm and 0.15-nm.",1912.00092v1
2019-12-16,Continuously Tunable Acoustic Metasurface with Rotatable Anisotropic Three-component Resonators,"We propose a tunable acoustic metasurface consisting of identical units. And
units are rotatable anisotropic three-component resonators, which can induce
the non-degenerate dipolar resonance, causing an evident phase change in low
frequencies. Compared with the monopole resonance widely used in Helmholtz
resonators, the polarization direction of the dipole resonance is a new degree
of freedom for phase manipulation. The proposed metasurface is constructed by
identical units that made with real (not rigid) materials. And the phase
profile can continuously change by rotating the anisotropic resonators. We
present a wide-angle and broad-band acoustic focusing by the metasurface under
a water background.",1912.07149v1
2020-03-27,Inverse resonance scattering for Dirac operators on the half-line,"We consider massless Dirac operators on the half-line with compactly
supported potentials. We solve the inverse problems in terms of Jost function
and scattering matrix (including characterization). We study resonances as
zeros of Jost function and prove that a potential is uniquely determined by its
resonances. Moreover, we prove the following:
  1) resonances are free parameters and a potential continuously depends on a
resonance,
  2) the forbidden domain for resonances is estimated,
  3) asymptotics of resonance counting function is determined,
  4) these results are applied to canonical systems.",2003.12502v2
2020-10-24,A Short Review of Plasmonic Graphene-Based Resonators: Recent Advances and Prospects,"This article aims to study graphene-based resonators published in the
literature. Graphene resonators are designed based on graphene conductivity, a
variable parameter that can be changed by either electrostatic or magnetostatic
gating. A historical review of plasmonic graphene resonators is presented in
this paper, which can give physical insight to the researchers to be
familiarized with four types of graphene-based resonators: 1-Ring resonators,
2- planar, 3- Fabry-Perot, and 4-other resonators which are not categorized in
any of the other three groups.",2011.14767v1
2022-02-15,Resonant phase lags of a Duffing oscillator,"This paper revisits the resonant behavior of a harmonically-forced Duffing
oscillator with a specific attention to phase resonance and to its relation
with amplitude resonance. To this end, the different families of resonances,
namely primary (1:1), superharmonic (k:1), subharmonic (1:{\nu}) and
ultra-subharmonic (k:{\nu}) resonances are carefully studied using first and
higher-order averaging. When the phase lag is calculated between the k-th
harmonic of the displacement and the harmonic forcing, this study evidences
that phase resonance occurs when the phase lag is equal to either {\pi}/2
(phase quadrature) or 3{\pi}/4{\nu}.",2202.07556v2
2022-03-31,Effect of Diffraction on Wigner Distributions of Optical Fields and how to Use It in Optical Resonator Theory. III -- Ray Tracing in Resonators,"The third part of the paper is devoted to ray tracing in optical resonators.
The employed method for dealing with the issue uses the elliptical or
hyperbolic rotations that Wigner distributions associated with optical fields
undergo during propagation from one spherical mirror of a resonator to the
other. It is illustrated by various examples concerning meridional or skew
rays, reentrant in stable resonators or propagating in unstable resonators.
  A classification of optical resonators is eventually deduced.",2203.16905v1
2024-03-06,High-Impedance Microwave Resonators with Two-Photon Nonlinear Effects,"In this article, we present an experimental study of a Josephson junction
-based high-impedance resonator. By taking the resonator to the limit of
consisting effectively only of one junction, results in strong non-linear
effects already for the second photon while maintaining a high impedance of the
resonance mode. Our experiment yields thus resonators with the strong
interactions both between individual resonator photons and from the resonator
photons to other electric quantum systems. We also present an energy diagram
technique which enables to measure, identify and analyse different multi-photon
optics processes along their energy conservation lines.",2403.03779v1
2004-07-19,On the saturation of corotation resonances: a numerical study,"[Abridged] The torque exerted by an external potential on a two-dimensional
gaseous disk at non-co-orbital corotation resonances is studied by means of
numerical simulations. The degree of saturation of these resonances is
important in determining whether an eccentric giant planet embedded in a
protoplanetary disk experiences an eccentricity excitation or damping. We
perform calculations restricted to one or two resonances to investigate the
properties of two neighboring corotation resonances, as well as the properties
of a corotation resonance that overlaps a Lindblad resonance. We find that
these properties hardly differ from the case of an isolated corotation
resonance. In particular, although the torque of two neighboring corotation
resonances may differ from the sum of the torques of the corresponding
resonances considered as isolated, it never exceeds the sum of the fully
unsaturated isolated corotation resonances, and it saturates in a fashion
similar to an isolated resonance. Similarly, the presence of an underlying
Lindblad resonance hardly affects the corotation torque, even if that resonance
implies a torque strong enough to significantly redistribute the azimuthally
averaged surface density profile, in which case the corotation torque scales
with the resulting vortensity gradient. This set of numerical experiments thus
essentially validates previous analytic studies. As a side result, we show that
corotation libration islands misrepresented by a mesh of too low resolution can
lead to a strongly overestimated corotation torque. This may be an explanation
why the eccentricity of embedded Jupiter-sized planets was never observed to
undergo an excitation in the numerical simulations performed so far.",0407403v1
2013-12-20,Atlas of three body mean motion resonances in the Solar System,"We present a numerical method to estimate the strengths of arbitrary three
body mean motion resonances between two planets in circular coplanar orbits and
a massless particle in an arbitrary orbit. This method allows us to obtain an
atlas of the three body resonances in the Solar System showing where are
located and how strong are thousands of resonances involving all the planets
from 0 to 1000 au. This atlas confirms the dynamical relevance of the three
body resonances involving Jupiter and Saturn in the asteroid belt but also
shows the existence of a family of relatively strong three body resonances
involving Uranus and Neptune in the far Trans-Neptunian region and relatively
strong resonances involving terrestrial and jovian planets in the inner
planetary system. We calculate the density of relevant resonances along the
Solar System resulting that the main asteroid belt is located in a region of
the planetary system with the lowest density of three body resonances. The
method also allows the location of the equilibrium points showing the existence
of asymmetric librations (sigma different from 0 or 180 degrees). We obtain the
functional dependence of the resonance's strength with the order of the
resonance and the eccentricity and inclination of the particle's orbit. We
identify some objects evolving in or very close to three body resonances with
Earth-Jupiter, Saturn-Neptune and Uranus-Neptune apart from Jupiter-Saturn, in
particular the NEA 2009 SJ18 is evolving in the resonance 1-1E-1J and the
centaur 10199 Chariklo is evolving under the influence of the resonance
5-2S-2N.",1312.6068v1
2018-05-10,Apparent spectral shift of thermally generated surface phonon-polariton resonance mediated by a non-resonant film,"The physical origin of spectral shift of thermally generated surface
phonon-polariton (SPhP) resonance of a silicon carbide (SiC) bulk mediated by a
non-resonant film is elucidated. The local density of electromagnetic states
(LDOS) in a non-resonant intrinsic silicon (Si) film due to thermal emission by
SiC, derived using fluctuational electrodynamics, exhibits a local maximum near
SPhP resonant frequency in addition to a lower frequency resonance generated by
gap modes emerging in the vacuum gap separating the SiC and Si layers. Multiple
reflections within the vacuum gap also induce a LDOS drop around SPhP resonant
frequency. As a result, depending on the film thickness to vacuum gap ratio and
the location where the LDOS is calculated in the film, the low-frequency
resonance can dominate the LDOS, such that SPhP resonance appears to be
redshifted. A similar spectral behavior is observed on the monochromatic
radiative heat flux absorbed by the Si film. It is shown that apparent spectral
(red and blue) shift of SPhP resonance mediated by a non-resonant film is
bounded by the transverse and longitudinal optical phonon frequencies of SiC.
This work is of importance in applications involving dissimilar materials, such
as thermophotovoltaics and thermal rectification, where gap modes may
significantly disrupt flux resonance. Gap modes may also be at the origin of
the resonance redshift systematically observed in near-field thermal
spectroscopy.",1805.03768v2
2016-05-20,Three-body resonance in meteoroid streams,"Mean-motion resonances play an important role in the evolution of various
meteoroid streams. Previous works have studied the effects of two-body
resonances in different comets and streams. These already established two-body
resonances were mainly induced either by Jovian or Saturnian effects but not
both at the same time. Some of these resonances have led to spectacular meteor
outbursts and storms in the past. In this work, we find a new resonance
mechanism involving three bodies -- i.e. meteoroid particle, Jupiter and
Saturn, in the Perseid meteoroid stream. Long-term three-body resonances are
not very common in real small bodies in our solar system although they can
mathematically exist at many resonant sweet spots in an abstract sense in any
dynamical system. This particular resonance combination in the Perseid stream
is such that it is close to the ratio of 1:4:10 if the orbital periods of
Perseid particle, Saturn and Jupiter are considered respectively. These
resonant Perseid meteoroids stay resonant for typically about 2 kyr. Highly
compact dust trails due to this unique resonance phenomenon are present in our
simulations. Some past and future years are presented where three-body resonant
meteoroids of different sizes (or subject to different radiation pressures) are
computed to come near the Earth. This is the first theoretical example of an
active and stable three-body resonance mechanism in the realm of meteoroid
streams.",1605.06340v1
2018-07-03,Structure resonance crossing in space charge dominated beams,"As an extension of previous theoretical study on the coherent structure
resonance due to space charge effects [Chao Li and R. A. Jameson, Phys. Rev.
Accel. Beams 21, 024204, 2018], this paper aims to demonstrate how the beam, as
a whole, is spontaneously affected when the predicted mixed coherent 2nd/4th
order structure resonance stop band around $90^{\circ}$ phase advance is
crossed. The beam characteristics during the structure resonance crossing, such
as the rms emittance growth and the appearance of 2-fold/4-fold structure in
phase space, are well explained by the mixture characteristic of different
orders of structure resonance. The related `attracting' and `repulsive' effects
in the structure resonance stop band from below and above crossing are
considered as a natural beam reaction to the coherent structure resonance that
the beam spontaneously moves to a structure resonance free region then the
space charge takes a weaker importance. In the PIC simulation, it is found that
the emittance growth is positively related to the time that the beam spends
inside the structure resonance stop band. As a potential candidate mechanism,
the incoherent particle-core resonance also has been checked. It is found that
this incoherent resonance has basic difficulties in explaining the results
obtained from the self-consistent PIC simulation. The incoherent particle-core
resonance might lead to phase space distortion, emittance growth, or beam halo
formation only on a long-time scale. This clarity of the discrepancies between
coherent and incoherent resonance mechanisms will lead to a better
understanding of the numerical study and experimental researches obtained
recently. In addition, similar understanding can be extended to the study of
higher order structure resonance.",1807.01204v1
2020-06-19,Robust interface-state laser in non-Hermitian micro-resonator arrays,"We propose a scheme to achieve the analogous interface-state laser by dint of
the interface between the two intermediate-resonator-coupled non-Hermitian
resonator chains. We find that, after introducing the couplings between the two
resonator chains and the intermediate resonator at the interface, the photons
of the system mainly gather into the three resonators near the intermediate
resonator. The phenomenon of the photon gathering towards the certain
resonators is expected to construct the photon storage and even the laser
generator. We reveal that the phenomenon is induced via the joint effect
between the isolated intermediate resonator and two kinds of non-Hermitian skin
effects. Specially, we investigate the interface-state laser in topologically
trivial non-Hermitian resonator array in detail. We find that the pulsed
interface-state laser can be achieved accompanying with the intermittent
proliferation of the photons at the intermediate resonator when an arbitrary
resonator is excited. Also, we reveal that the pulsed interface-state laser in
the topologically trivial non-Hermitian resonator array is immune to the
on-site defects in some cases, whose mechanism is mainly induced by the
nonreciprocal couplings instead of the protection of topology. Our scheme
provides a promising and excellent platform to investigate interface-state
laser in the micro-resonator array.",2006.10943v1
2023-06-30,Confirming Resonance in Three Transiting Systems,"Although resonant planets have orbital periods near commensurability,
resonance is also dictated by other factors, such as the planets'
eccentricities and masses, and therefore must be confirmed through a study of
the system's dynamics. Here, we perform such a study for five multi-planet
systems: Kepler-226, Kepler-254, Kepler-363, Kepler-1542, and K2-32. For each
system, we run a suite of N-body simulations that span the full parameter-space
that is consistent with the constrained orbital and planetary properties. We
study the stability of each system and look for resonances based on the
libration of the critical resonant angles. We find strong evidence for a
two-body resonance in each system; we confirm a 3:2 resonance between
Kepler-226c and Kepler-226d, confirm a 3:2 resonance between Kepler-254c and
Kepler-254d, and confirm a three-body 1:2:3 resonant chain between the three
planets of Kepler-363. We explore the dynamical history of two of these systems
and find that these resonances most likely formed without migration. Migration
leads to the libration of the three-body resonant angle, but these angles
circulate in both Kepler-254 and Kepler-363. Applying our methods to additional
near-resonant systems could help us identify which systems are truly resonant
or non-resonant and which systems require additional follow-up analysis.",2306.17751v1
2007-03-21,Resonances in Barred Galaxies,"The inner parts of many spiral galaxies are dominated by bars. These are
strong non-axisymmetric features which significantly affect orbits of stars and
dark matter particles. One of the main effects is the dynamical resonances
between galactic material and the bar. We detect and characterize these
resonances in N-body models of barred galaxies by measuring angular and radial
frequencies of individual orbits. We found narrow peaks in the distribution of
orbital frequencies with each peak corresponding to a specific resonance. We
found five different resonances in the stellar disk and two in the dark matter.
The corotation resonance and the inner and outer Lindblad resonances are the
most populated. The spatial distributions of particles near resonances are
wide. For example, the inner Lindblad resonance is not localized at a given
radius. Particles near this resonance are mainly distributed along the bar and
span a wide range of radii. On the other hand, particles near the corotation
resonance are distributed in two broad areas around the two stable Lagrange
points. The distribution resembles a wide ring at the corotation radius.
Resonances capture disk and halo material in near-resonant orbits. Our analysis
of orbits in both N-body simulations and in simple analytical models indicates
that resonances tend to prevent the dynamical evolution of this trapped
material. Only if the bar evolves as a whole, resonances drift through the
phase space. In this case particles anchored near resonant orbits track the
resonance shift and evolve. The criteria to ensure a correct resonant behavior
discussed in Weinberg & Katz (2007a) can be achieved with few millions
particles because the regions of trapped orbits near resonances are large and
evolving.",0703544v2
2012-06-07,Massive identification of asteroids in three-body resonances,"An essential role in the asteroidal dynamics is played by the mean motion
resonances. Two-body planet-asteroid resonances are widely known, due to the
Kirkwood gaps. Besides, so-called three-body mean motion resonances exist, in
which an asteroid and two planets participate. Identification of asteroids in
three-body (namely, Jupiter-Saturn-asteroid) resonances was initially
accomplished by D.Nesvorny and A.Morbidelli (1998), who, by means of visual
analysis of the time behaviour of resonant arguments, found 255 asteroids to
reside in such resonances. We develop specialized algorithms and software for
massive automatic identification of asteroids in the three-body, as well as
two-body, resonances of arbitrary order, by means of automatic analysis of the
time behaviour of resonant arguments. In the computation of orbits, all
essential perturbations are taken into account. We integrate the asteroidal
orbits on the time interval of 100000 yr and identify main-belt asteroids in
the three-body Jupiter-Saturn-asteroid resonances up to the 6th order
inclusive, and in the two-body Jupiter-asteroid resonances up to the 9th order
inclusive, in the set of ~250000 objects from the ""Asteroids - Dynamic Site""
(AstDyS) database. The percentages of resonant objects, including
extrapolations for higher-order resonances, are determined. In particular, the
observed fraction of pure-resonant asteroids (those exhibiting resonant
libration on the whole interval of integration) in the three-body resonances up
to the 6th order inclusive is approximately 0.9% of the whole set; and, using a
higher-order extrapolation, the actual total fraction of pure-resonant
asteroids in the three-body resonances of all orders is estimated as
approximately 1.1% of the whole set.",1206.1451v2
2014-10-08,Statistical distributions of mean motion resonances and near-resonances in multiplanetary systems,"The orbits of the confirmed exoplanets from all multiple systems known to
date are investigated. Observational data from 1890 objects, of which 1176 are
found in multiplanetary systems, are compiled and analyzed. Mean motion
resonances and near-resonances up to the outer/inner orbital period ratio's
value of 5 and the denominator 4 are tested for all adjacent exoplanet orbits.
Each host star's snow line is calculated using a simple algorithm. The planets
are reclassified into categories as a function of the semimajor axis size
relative to the snow line location and the semimajor axis vs mass distribution.
The fraction of planets in/near resonance is then plotted as a function of both
resonance number and resonance order for all the exoplanet population and,
separately, for each planet type. In the resonance number plot it appears that
the 2/1 and 3/2 resonances and near-resonances are dominant overall and for the
giant planets, but the observed distribution profile changes significantly with
each planet category, with terrestrial planets, neptunes and mini-neptunes
showing the largest variation. Resonances/near resonances around the value 5/3
were dominant for mini neptunes and terrestrial planets. In the order-based
resonance/near-resonance plot, the observed distribution appears to follow an
exponential decay for the general population and its profile appears to be
influenced by the planet type. Approximate methods to estimate resonance/near
resonance distributions are also attempted for the systems with unknown planet
mass or with unknown star and/or planet mass and compared with the distribution
of the planets with all the parameters known. A separate study of the
resonance/near resonance fraction distribution as a function of mass is also
attempted, but the low statistical data at very high planetary masses prevent
the finding of an accurate equation to describe such a dependency.",1410.2478v3
2015-04-29,The 5:1 Neptune Resonance as Probed by CFEPS: Dynamics and Population,"The Canada-France Ecliptic Plane Survey discovered four trans-Neptunian
objects with semi-major axes near the 5:1 resonance, revealing a large and
previously undetected intrinsic population. Three of these objects are
currently resonant with Neptune, and the fourth is consistent with being an
object that escaped the resonance at some point in the past. The non-resonant
object may be representative of a detached population that is stable at
slightly lower semi-major axes than the 5:1 resonance. We generated clones of
these objects by resampling the astrometric uncertainty and examined their
behavior over a 4.5 Gyr numerical simulation. The majority of the clones of the
three resonant objects (>90%) spend a total of 10^7 years in resonance during
their 4.5 Gyr integrations; most clones experience multiple periods of
resonance capture. Our dynamical integrations reveal an exchange between the
5:1 resonance, the scattering objects, and other large semi-major axis
resonances, especially the 4:1, 6:1, and 7:1. The multiple capture events and
relatively short resonance lifetimes after capture suggest that these objects
are captured scattering objects that stick in the 5:1 resonance. These 5:1
resonators may be representative of a temporary population, requiring regular
contributions from a source population. We examined the dynamical
characteristics (inclination, eccentricity, resonant island, libration
amplitude) of the detected objects and their clones in order to provide an
empirical model of the orbit structure of the 5:1 resonance. This resonance is
dynamically hot and includes primarily symmetric librators. Given our orbit
model, the intrinsic population necessary for the detection of these three
objects in the 5:1 resonance is 1900(+3300 -1400, 95% confidence) with H_g< 8
and e > 0.5.",1504.08041v1
1998-02-25,Extensive spiral structure and corotation resonance,"Spiral density wave theories demand that grand design spiral structure be
bounded, at most, between the inner and outer Lindblad resonances of the spiral
pattern. The corotation resonance lies between the outer and inner Lindblad
resonances. The locations of the resonances are at radii whose ratios to each
other are rather independent of the shape of the rotation curve. The measured
ratio of outer to inner extent of spiral structure for a given spiral galaxy
can be compared to the standard ratio of corotation to inner Lindblad resonance
radius. In the case that the measured ratio far exceeds the standard ratio, it
is likely that the corotation resonance is within the bright optical disk.
Studying such galaxies can teach us how the action of resonances sculpts the
appearance of spiral disks. This paper reports observations of 140 disk
galaxies, leading to resonance ratio tests for 109 qualified spirals. It lists
candidates that have a good chance of having the corotation resonance radius
within the bright optical disk.",9802325v1
2006-06-29,Parametric coupling between macroscopic quantum resonators,"Time-dependent linear coupling between macroscopic quantum resonator modes
generates both a parametric amplification also known as a {}""squeezing
operation"" and a beam splitter operation, analogous to quantum optical systems.
These operations, when applied properly, can robustly generate entanglement and
squeezing for the quantum resonator modes. Here, we present such coupling
schemes between a nanomechanical resonator and a superconducting electrical
resonator using applied microwave voltages as well as between two
superconducting lumped-element electrical resonators using a r.f.
SQUID-mediated tunable coupler. By calculating the logarithmic negativity of
the partially transposed density matrix, we quantitatively study the
entanglement generated at finite temperatures. We also show that
characterization of the nanomechanical resonator state after the quantum
operations can be achieved by detecting the electrical resonator only. Thus,
one of the electrical resonator modes can act as a probe to measure the
entanglement of the coupled systems and the degree of squeezing for the other
resonator mode.",0606787v2
2007-03-06,Dynamical instabilities of a resonator driven by a superconducting single-electron transistor,"We investigate the dynamical instabilities of a resonator coupled to a
superconducting single-electron transistor (SSET) tuned to the Josephson
quasiparticle (JQP) resonance. Starting from the quantum master equation of the
system, we use a standard semiclassical approximation to derive a closed set of
mean field equations which describe the average dynamics of the resonator and
SSET charge. Using amplitude and phase coordinates for the resonator and
assuming that the amplitude changes much more slowly than the phase, we explore
the instabilities which arise in the resonator dynamics as a function of
coupling to the SSET, detuning from the JQP resonance and the resonator
frequency. We find that the locations (in parameter space) and sizes of the
limit cycle states predicted by the mean field equations agree well with
numerical solutions of the full master equation for sufficiently weak
SSET-resonator coupling. The mean field equations also give a good qualitative
description of the set of dynamical transitions in the resonator state that
occur as the coupling is progressively increased.",0703150v1
1999-04-08,Analysis of Narrow s-channel Resonances at Lepton Colliders,"The procedures for studying a single narrow s-channel resonance or nearly
degenerate resonances at a lepton collider, especially a muon collider, are
discussed. In particular, we examine four methods for determining the
parameters of a narrow s-channel resonance: scanning the resonance, measuring
the convoluted cross section, measuring the Breit-Wigner area, and sitting on
the resonance while varying the beam energy resolution. This latter procedure
is new and appears to be potentially very powerful. Our focus is on computing
the errors in resonance parameters resulting from uncertainty in the beam
energy spread. Means for minimizing these errors are discussed. The discussion
is applied to the examples of a light SM-Higgs, of the lightest pseudogoldstone
boson of strong electroweak breaking, and of the two spin-1 resonances of the
Degenerate BESS model (assuming that the beam energy spread is less than their
mass splitting). We also examine the most effective procedures for nearly
degenerate resonances, and apply these to the case of Degenerate BESS
resonances with mass splitting of order the beam energy spread.",9904268v1
2004-10-05,"Above-well, Stark, and potential-barrier resonances of an open square well in a static external electric field","Besides the well known Stark resonances, which are localized in the potential
well and tunnel through the potential barrier created by the dc-field,
""strange"" long and short-lived resonances are analytically obtained. These
resonances are not localized inside the potential well. We show that the narrow
ones are localized above the potential well. These narrow resonances give rise
to a {\it peak structure} in a 1D scattering experiment. We also show that the
broad overlapping resonances are associated with the static electric field
potential barrier. These ""strange"" overlapping resonances do not give rise to a
{\it peak structure} in a 1D scattering experiment. We propose a 2D
experimental set-up where in principle these short-lived states should be
observed as {\it peaks}. Broad overlapping resonances, associated only with the
static electric field potential barrier, could also have observable effects in
a $N>1$ array of quantum wells in the presence of a truncated static electric
field. This last problem is associated with the resonance tunnelling phenomena
which are used in the construction of resonance-tunnelling diodes and
transistors.",0410026v1
2007-06-26,Dynamical Response of Nanomechanical Resonators to Biomolecular Interactions,"We studied the dynamical response of a nanomechanical resonator to
biomolecular (e.g. DNA) adsorptions on a resonator's surface by using a
theoretical model, which considers the Hamiltonian H such that the potential
energy consists of elastic bending energy of a resonator and the potential
energy for biomolecular interactions. It was shown that the resonant frequency
shift of a resonator due to biomolecular adsorption depends on not only the
mass of adsorbed biomolecules but also the biomolecular interactions.
Specifically, for dsDNA adsorption on a resonator's surface, the resonant
frequency shift is also dependent on the ionic strength of a solvent, implying
the role of molecular interactions on the dynamic behavior of a resonator. This
indicates that nanomechanical resonators may enable one to quantify the
biomolecular mass, implying the enumeration of biomolecules, as well as gain
insight into intermolecular interactions between adsorbed biomolecules on the
surface.",0706.3743v3
2007-08-06,Noise Suppression for Micromechanical Resonator via Intrinsic Dynamic Feedback,"We study a dynamic mechanism to passively suppress the thermal noise of a
micromechanical resonator through an intrinsic self-feedback that is genuinely
non-Markovian. We use two coupled resonators, one as the target resonator and
the other as an ancillary resonator, to illustrate the mechanism and its noise
reduction effect. The intrinsic feedback is realized through the dynamics of
coupling between the two resonators: the motions of the target resonator and
the ancillary resonator mutually influence each other in a cyclic fashion.
Specifically, the states that the target resonator has attained earlier will
affect the state it attains later due to the presence of the ancillary
resonator. We show that the feedback mechanism will bring forth the effect of
noise suppression in the spectrum of displacement, but not in the spectrum of
momentum.",0708.0706v2
2007-12-19,Formation and transformation of the 3:1 mean-motion resonance in 55 Cancri System,"We report in this paper the numerical simulations of the capture into the 3:1
mean-motion resonance between the planet b and c in the 55 Cancri system. The
results show that this resonance can be obtained by a differential planetary
migration. The moderate initial eccentricities, relatively slower migration and
suitable eccentricity damping rate increase significantly the probability of
being trapped in this resonance. Otherwise, the system crosses the 3:1
commensurability avoiding resonance capture, to be eventually captured into a
2:1 resonance or some other higher-order resonances. After the resonance
capture, the system could jump from one orbital configuration to another one if
the migration continues, making a large region of the configuration space
accessible for a resonance system. These investigations help us understand the
diversity of resonance configurations and put some constrains on the early
dynamical evolution of orbits in the extra-solar planetary systems.",0712.3138v1
2008-08-08,Fano-like Anti-resonances in Nanomechanical and Optomechanical Systems,"We study a resonator coupled to a generic detector and calculate the noise
spectra of the two sub-systems. We describe the coupled system by a closed,
linear, set of Langevin equations and derive a general form for the finite
frequency noise of both the resonator and the detector. The resonator spectrum
is the well-known thermal form with an effective damping, frequency shift and
diffusion term. In contrast, the detector noise shows a rather striking
Fano-like resonance, i.e. there is a resonance at the renormalized frequency,
and an anti-resonance at the bare resonator frequency. As examples of this
effect, we calculate the spectrum of a normal state single electron transistor
coupled capacitively to a resonator and of a cavity coupled parametrically to a
resonator.",0808.1169v2
2011-07-14,Decoherence Suppression by Cavity Optomechanical Cooling,"We consider a cavity optomechanical cooling configuration consisting of a
mechanical resonator (denoted as resonator b) and an electromagnetic resonator
(denoted as resonator a), which are coupled in such a way that the effective
resonance frequency of resonator a depends linearly on the displacement of
resonator b. We study whether back-reaction effects in such a configuration can
be efficiently employed for suppression of decoherence. To that end, we
consider the case where the mechanical resonator is prepared in a superposition
of two coherent states and evaluate the rate of decoherence. We find that no
significant suppression of decoherence is achievable when resonator a is
assumed to have a linear response. On the other hand, when resonator a exhibits
Kerr nonlinearity and/or nonlinear damping the decoherence rate can be made
much smaller than the equilibrium value provided that the parameters that
characterize these nonlinearities can be tuned close to some specified optimum
values.",1107.2746v1
2011-09-05,Nucleon resonances in the fourth resonance region,"Nucleon and $\Delta$ resonances in the fourth resonance region are studied in
a multichannel partial-wave analysis which includes nearly all available data
on pion- and photo-induced reactions off protons. In the high-mass range, above
1850\,MeV, several alternative solutions yield a good description of the data.
For these solutions, masses, widths, pole residues and photo-couplings are
given. In particular, we find evidence for nucleon resonances with
spin-parities $J^P=1/2^+...7/2^+$. For one set of solutions, there are four
resonances forming naturally a spin-quartet of resonances with orbital angular
momentum L=2 and spin S=3/2 coupling to $J=1/2,...,7/2$. Just below 1.9\,GeV we
find a spin doublet of resonances with $J^P=1/2^-$ and $3/2^-$. Since a spin
partner with $J^P=5/2^-$ is missing at this mass, the two resonances form a
spin doublet which must have a symmetric orbital-angular-momentum wave function
with L=1. For another set of solutions, the four positive-parity resonances are
accompanied by mass-degenerate negative-parity partners -- as suggested by the
conjecture of chiral symmetry restoration. The possibility of a $J^P=1/2^+,
3/2^+$ spin doublet at 1900\,MeV belonging to a 20-plet is discussed.",1109.0970v1
2014-02-06,Higher order transmission resonances in above-barrier reflection of ultra-cold atoms,"The reflectionless transmission resonances in above-barrier reflection of
Bose-Einstein condensates by the Rosen-Morse potential are considered using the
mean field Gross-Pitaevskii approach. Applying an exact third order nonlinear
differential equation obeyed by the condensate's density, the exact solution of
the problem for the first resonance is derived. It is shown that in the
nonlinear case the total transmission is possible for positive potential
heights, i.e., for potential barriers. Further, it is shown that an appropriate
approximation for higher-order resonances can be constructed using a limit
solution of the equation for the density written as a root of a polynomial
equation of the third degree. Using this limit function and the solution for
the first resonance, a simple approximation for the shift of the nonlinear
resonance potential's depth from the corresponding linear resonance's position
is constructed for higher order resonances. The result is written as a linear
function of the resonance order. This behavior notably differs from the case of
the rectangular barrier for which the nonlinear shift is approximately constant
for all the resonance orders.",1402.1311v1
2014-11-24,A Broadband Dipolar Resonance in THz Metamaterials,"We demonstrate a THz metamaterial with broadband dipole resonance originating
due to the hybridization of LC resonances. The structure optimized by finite
element method simulations is fabricated by electron beam lithography and
characterized by terahertz time-domain spectroscopy. Numerically, we found that
when two LC metamaterial resonators are brought together, an electric dipole
resonance arises in addition to the LC resonances. We observed a strong
dependence of the width of these resonances on the separation between the
resonators. This dependence can be explained based on series and parallel RLC
circuit analogies. The broadband dipole resonance appears when both the
resonators are fused together. The metamaterial has a stopband with FWHM of
0.47 THz centered at 1.12 THz. The experimentally measured band features are in
reasonable agreement with the simulated ones. The experimental power extinction
ratio of THz in the stopbands is found to be 15 dB.",1411.6464v1
2015-04-14,Theory of the nanoparticle-induced frequency shifts of whispering-gallery-mode resonances in spheroidal optical resonators,"Nanoparticle-induced modifications of the spectrum of
whispering-gallery-modes (WGM) of optical spheroidal resonators are studied
theoretically. Combining an ab initio solution of a single resonator problem
with a dipole approximation for the particle, we derive simple analytical
expressions for frequencies and widths of the particle-modified resonances,
which are valid for resonators with moderate deviations from the spherical
shape. The derived expressions are used to analyze spectral properties of the
resonator-particle system as functions of the particle's position, the size of
the resonators and the characteristics of WGMs. The obtained results are shown
to agree well with available experimental data. It is also demonstrated that
the particle-induced spectral effects can be significantly enhanced by careful
selection of resonator's size, refractive index and other experimental
parameters. The results presented in the paper can be useful for applications
of WGM resonators in biosensing, cavity QED, optomechanics and others.",1504.03399v2
2016-01-05,Collective resonances of atomic xenon from the linear to the nonlinear regime,"XUV nonlinear spectroscopy has recently discovered that there is more than
one collective dipole resonance state in the energy range of the giant dipole
resonance (GDR) of atomic Xe. This resonance-state substructure, hidden in the
linear regime, raises imminent questions regarding our understanding of the
collective electronic behavior of Xe, which has been largely founded on linear
spectroscopic studies. Here, we approach the collective response of Xe from a
new perspective: we study directly the resonance eigenstates, and then analyze
their spectroscopic manifestations. We find that linear spectroscopy captures
only partial information on the resonance substructure as a result of quantum
interferences. Moreover, we show that the resonance state dominating the GDR in
linear spectroscopy has no adiabatic connection to the resonance state
governing the corresponding cross section when multielectron interactions are
neglected. Going beyond the dipole-allowed correlated electronic structure, we
predict the existence of collective multipole resonances of Xe. Unlike any
known collective feature in atoms, these resonances live exceptionally long
(more than 100 attoseconds), thus providing a new playground for studying the
collective nonlinear response of Xe using advanced light sources.",1601.00869v2
2016-03-31,Resonant terms on gyrocenter coordinates introduced by resonant electromagnetic perturbations,"It's pointed out that the treatment of the resonant electromagnetic
perturbation with the Lie transform method adopted in the gyrokinetic theory
generates some nonphysical terms in the trajectory equations. By utilizing a
modified application of this transform method, the resonant terms in the
trajectory equations satisfying each resonant condition are found out up to the
second harmonic resonance. Through separating the fast-dynamic terms from the
slow-dynamic ones, the slow-dynamic trajectory equations including the resonant
terms are derived for various resonant conditions. The slow-dynamic evolution
equation of gyroangle reveals that the real gyrating frequency of the charged
particle around the magnetic field line under driving by the resonant wave has
a shift from the cyclotron frequency without the wave driving. To study the
effect caused by the frequency shift, a simple example for the
fundamental-frequency cyclotron resonance is presented.",1603.09632v5
2017-06-28,Towards N-mode parametric electromechanical resonances,"The ubiquity of parametric resonance is continually evident in the repeated
experimental observations of this phenomenon in multiple physical systems. The
elementary case of 2 mode parametric resonance of order 1 involves the
excitation of a spectral tone of a parametrically driven mode at a sub-harmonic
frequency of the higher directly driven mode. Historically, such examples of
parametric resonance have been predominantly researched in a system of micro-
and nanoelectromechanical resonators. Here, in this paper, we break this
convention by showcasing a collection of experimental signatures in support of
the concept of ""N-mode parametric resonance"" using a number of elementary
microelectromechanical devices. Specifically, we present observations of 2, 3,
(2+3) and (3+3) mode parametric resonances demonstrating co-existence of
different regimes within the same device. In addition, we also present
observations of intrinsic ""Four-Wave Mixing"" of parametric excitations. This
paper presents contributions towards the existence proof for such multimode
parametric resonances which can also be exploited for engineering benefit
within the field of ""micro and nanoelectromechanical resonators"". The
experimental results further point towards the possibility of the ultimate
observation of N-mode parametric resonance in such physical system.",1708.01660v1
2016-07-30,Spoof surface plasmon Fabry-Perot open resonators in a surface-wave photonic crystal,"We report on the proposal and experimental realization of a spoof surface
plasmon Fabry-Perot (FP) open resonator in a surface-wave photonic crystal.
This surface-wave FP open resonator is formed by introducing a finite line
defect in a surface-wave photonic crystal. The resonance frequencies of the
surface-wave FP open resonator lie exactly within the forbidden band gap of the
surface-wave photonic crystal and the FP open resonator uses this complete
forbidden band gap to concentrate surface waves within a subwavelength cavity.
Due to the complete forbidden band gap of the surface-wave photonic crystal, a
new FP plasmonic resonance mode that exhibits monopolar features which is
missing in traditional FP resonators and plasmonic resonators is demonstrated.
Near-field response spectra and mode profiles are presented in the microwave
regime to characterize properties of the proposed FP open resonator for spoof
surface plasmons.",1608.00080v1
2017-06-22,Multipole resonances and directional scattering by hyperbolic-media antennas,"We propose to use optical antennas made out of natural hyperbolic material
hexagonal boron nitride (hBN), and we demonstrate that this medium is a
promising alternative to plasmonic and all-dielectric materials for realizing
efficient subwavelength scatterers and metasurfaces based on them. We
theoretically show that particles out of hyperbolic medium possess different
resonances enabled by the support of high-k waves and their reflection from the
particle boundaries. Among those resonances, there are electric quadrupole
excitations, which cause magnetic resonance of the particle similar to what
occurs in high-refractive-index particles. Excitations of the particle
resonances are accompanied by the drop in the reflection from nanoparticle
array to near-zero value, which can be ascribed to resonant Kerker effect. If
particles are arranged in the spacer array with period d, narrow lattice
resonances are possible at wavelength d, d/2, d/3 etc. This provides an
additional degree of control and possibility to excite resonances at the
wavelength defined by the array spacing. For the hBN particle with hyperbolic
dispersion, we show that the full range of the resonances, including magnetic
resonance and a decrease of reflection, is possible.",1706.07259v1
2019-06-06,Evolution of the resonances of two parallel dielectric cylinders with distance between them,"We study behavior of resonant modes under change of the distance between two
parallel dielectric cylinders. The processes of mutual scattering of Mie
resonant modes by cylinders result in an interaction between the cylinders
which lifts a degeneracy of resonances of the isolated cylinders. There are two
basic scenarios of evolution of resonances with the distance. For strong
interaction of cylinders resonances are unbound with avoided crossings from the
of the Mie resonances with increasing of the distance. That scenario is typical
for low exciting resonances (monopole and dipole). For weak interaction of
cylinders the resonances are bound around highly excited Mie resonances. Both
scenarios demonstrate a significant enhancement of the $Q$ factor compared to
the case of isolated cylinder.",1906.02409v1
2020-04-17,S-band electron spin resonance spectroscopy using a short-circuited coplanar waveguide resonator,"In this work, we study the development of a coplanar waveguide (CPW)
resonator and its use in an electron spin resonance (ESR) spectrometer. The CPW
resonator is designed to operate in S-band. It has a short circuit
configuration which leads to miniaturization. It is so constructed such that it
has a characteristic impedance of 50 ohms. Detailed electromagnetic simulation
with a particular emphasis on the excitation of the structure has been
performed for this resonator owing to its uniplanar nature. The design
parameters and the electromagnetic field distribution are obtained from the
simulation. The resonator is fabricated using optical lithography with a rapid
prototyping technique. The characteristic response of the resonator is measured
by coupling it to a Vector Network Analyzer (VNA). The ESR absorption spectrum
of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) is captured by using this
resonator in reflection geometry. The microwave magnetic field distribution at
the sample position is investigated.The measured g-factor value is found to be
consistent with that reported in the literature. The quality factor of this
resonator is found to be low and this makes it suitable for use in a Pulsed ESR
spectrometer.",2004.08061v1
2019-01-10,From Fano resonances to bound states in the continuum in dipole arrays at THz frequencies,"Fano resonances and bound states in the continuum (BICs) exhibit a rich
phenomenology stemming from, respectively, their asymmetric line shapes and
infinite quality factors. Here, we show experimentally and theoretically that
rod dimer metasurfaces exhibit narrow (high-Q) Fano resonances at THz
frequencies. These resonances evolve continuously into a BIC as the rods in
each dimer become identical. We demonstrate analytically that this is a
universal behavior occurring in arrays of dimers consisting of detuned resonant
dipoles. Fano resonances arise as a result of the interference between broad
and narrow lattice dipole resonances, with high-Q factors tending to infinity
in the detuning parameter space as the narrow lattice resonance becomes a BIC
for identical resonant dipoles. Similar configurations can be straightforwardly
envisioned throughout the electromagnetic spectrum leading to ultrahigh-Q Fano
resonances and BICs of interest in photonics applications such as sensing and
lasing.",1901.03122v1
2019-03-22,On the geometry optimization of X-band resonator for electron paramagnetic resonance application,"The microwave resonator is one of the key components in the modern Electron
Paramagnetic Resonance (EPR) spectroscopy setup, as it largely determines the
performance characteristics and limitations of the entire spectrometer. In this
research note the possible way of resonator optimization is described. A
detailed computer model describing the distribution of the electromagnetic
field for Bruker 4118X-MD-5W1 design resonator has been developed. All details
including a dielectric insert, conductive screen, coupling antenna and PTFE
supports were included in the model. All dissipation processes were considered
in the calculation. The influence of the resonator geometry on the Q-factor,
filling factor and operating frequency of the resonant mode has been
investigated. The resonator geometric parameters are optimized to achieve
maximum sensitivity. According to the calculations, the optimized resonator
structure has in 10 times greater sensitivity than the original MD-5 design.",1904.01657v1
2020-10-28,Phase resonance nonlinear modes of mechanical systems,"The resonances of forced dynamical systems occur when either the amplitude of
the frequency response undergoes a local maximum (amplitude resonance) or phase
lag quadrature takes places (phase resonance). This study focuses on the phase
resonance of nonlinear mechanical systems subjected to single-point,
single-harmonic excitation. In this context, the main contribution of this
paper is to develop a computational framework which can predict the mode shapes
and oscillation frequencies at phase resonance. The resulting nonlinear modes
are termed phase resonance nonlinear modes (PRNMs). A key property of PRNMs is
that, besides primary resonances, they can accurately characterize
superharmonic, subharmonic and ultra-subharmonic resonances for which, as shall
be shown in this paper, phase lags at resonance may be different from pi/2. The
proposed developments are demonstrated using one- and two-degree-of-freedom
systems featuring a cubic nonlinearity.",2010.14892v4
2022-01-28,Three-Body Resonances in the Saturnian System,"Saturn has a dynamically rich satellite system, which includes at least three
orbital resonances between three pairs of moons: Mimas-Tethys 4:2,
Enceladus-Dione 2:1, and Titan-Hyperion 4:3 mean-motion resonances. Studies of
the orbital history of Saturn's moons usually assume that their past dynamics
was also dominated solely by two-body resonances. Using direct numerical
integrations, we find that three-body resonances among Saturnian satellites
were quite common in the past, and could result in a relatively long-term, but
finite capture time (10 Myr or longer). We find that these three-body
resonances are invariably of the eccentricity type, and do not appear to affect
the moons' inclinations. While some three-body resonances are located close to
two-body resonances (but involve the orbital precession of the third body),
others are isolated, with no two-body arguments being near resonance. We
conclude that future studies of the system's past must take full account of
three-body resonances, which have been overlooked in the past work.",2201.12313v1
2022-02-21,Efimov resonance position near a narrow Feshbach resonance in $^6$Li-$^{133}$Cs mixture,"In the vicinity of a narrow Feshbach resonances Efimov features are expected
to be characterized by the resonance's properties rather than the van der Waals
length of the interatomic potential. Although this theoretical prediction is
well-established by now, it still lacks experimental confirmation. Here, we
apply our recently developed three-channel model [Yudkin and Khaykovich, Phys.
Rev. A 103, 063303 (2021)] to the experimental result obtained in a
mass-imbalanced $^6$Li-$^{133}$Cs mixture in the vicinity of the narrowest
resonance explored to date [Johansen at. al. Nat. Phys. 13, 731 (2017)]. We
confirm that the observed position of the Efimov resonance is dictated mainly
by the resonance physics while the influence of the van der Waals tail of the
interatomic potential is minor. We show that the resonance position is strongly
influenced by the presence of another Feshbach resonance which significantly
alters the effective background scattering length at the narrow resonance
position.",2202.10358v1
2023-05-23,The interaction between two close-to-touching convex acoustic subwavelength resonators,"The Minneart resonance is a low frequency resonance in which the wavelength
is much larger than the size of the resonators. It is interesting to study the
interaction between two adjacent bubbles when they are brought close together.
Because the bubbles are usually compressible, in this paper we mainly
investigate resonant modes of two general convex resonators with arbitrary
shapes to extend the results of Ammari, Davies, Yu in [4], where a pair of
spherical resonators are considered by using bispherical coordinates. We
combine the layer potential method for Helmholtz equation in [4,5] and the
elliptic theory for gradient estimates in [26,30] to calculate the capacitance
coefficients for the coupled $C^{2,\alpha}$ resonators, then show the
leading-order asymptotic behaviors of two different resonant modes and reveal
the dependance of the resonant frequencies on their geometric properties, such
as convexity, volumes and curvatures. By the way, the blow-up rates of gradient
of the scattered pressure are also presented.",2305.13789v1
2000-12-21,The Capture of Particles by Chaotic Resonances During Orbital Migration,"Because a chaotic zone can reduce the long timescale capture probabilities
and cause catastrophic events such as close encounters with a planet or star
during temporary capture, the dynamics of migrating planets is likely to be
strongly dependent on the widths of the resonance chaotic zones. Previous
theoretical work on the resonant capture of particles into mean-motion
resonances by orbital migration has been restricted to the study of integrable
models. By exploring toy drifting Hamiltonian models we illustrate how the
structure in phase space of a resonance can be used to generalize this
integrable capture theory to include the richer phenomenology of chaotic
resonances. We show that particles are temporarily captured into the chaotic
zone of a resonance with fixed shape for a time that is given by the width of
the chaotic zone divided by the resonance drift rate. Particles can be
permanently captured into a drifting chaotic resonance only if they are
captured into a growing integrable region. Therefore resonances containing wide
chaotic zones have lower permanent capture probabilities than those lacking
chaotic zones. We expect large deviations from the predictions of integrable
capture theories when the chaotic zone is large and the migration rate is
sufficiently long that many Lyapunov times pass while particles are temporarily
captured in the resonance. The 2:1 mean-motion resonance with Neptune in the
Kuiper Belt contains a chaotic zone, even when integrated on short timescales
such as a million years. Capture probabilities are lower than estimated
previously from drifting integrable models. This may offer an explanation for
low eccentricity Kuiper Belt objects between 45-47 AU which should have been
previously captured in the 2:1 resonance by Neptune's migration.",0012466v2
2005-07-20,Reducing the Probability of Capture into Resonance,"A migrating planet can capture planetesimals into mean motion resonances.
However, resonant trapping can be prevented when the drift or migration rate is
sufficiently high. Using a simple Hamiltonian system for first and second order
resonances, we explore how the capture probability depends on the order of the
resonance, drift rate and initial particle eccentricity. We present scaling
factors as a function of the planet mass and resonance strength to estimate the
planetary migration rate above which the capture probability drops to less than
1/2. Applying our framework to multiple extra solar planetary systems that have
two planets locked in resonance, we estimate lower limits for the outer
planet's migration rate allowing resonance capture of the inner planet. Mean
motion resonances are comprised of multiple resonant subterms. We find that the
corotation subterm can reduce the probability of capture when the planet
eccentricity is above a critical value. We present factors that can be used to
estimate this critical planet eccentricity. Applying our framework to the
migration of Neptune, we find that Neptune's eccentricity is near the critical
value that would make its 2:1 resonance fail to capture twotinos. The capture
probability is affected by the separation between resonant subterms and so is
also a function of the precession rates of the longitudes of periapse of both
planet and particle near resonance.",0507477v2
2008-06-09,Current noise of a superconducting single electron transistor coupled to a resonator,"We analyze the current and zero-frequency current noise properties of a
superconducting single electron resonator (SSET) coupled to a resonator,
focusing on the regime where the SSET is operated in the vicinity of the
Josephson quasiparticle resonance. We consider a range of coupling strengths
and resonator frequencies to reflect the fact that in practice the system can
be tuned to quite a high degree with the resonator formed either by a
nanomechanical oscillator or a superconducting stripline fabricated in close
proximity to the SSET. For very weak couplings the SSET acts on the resonator
like an effective thermal bath. In this regime the current characteristics of
the SSET are only weakly modified by the resonator. Using a mean field
approach, we show that the current noise is nevertheless very sensitive to the
correlations between the resonator and the SSET charge. For stronger couplings,
the SSET can drive the resonator into limit cycle states where self-sustained
oscillation occurs and we find that regions of well-defined bistability exist.
Dynamical transitions into and out of the limit cycle state are marked by
strong fluctuations in the resonator energy, but these fluctuations are
suppressed within the limit cycle state. We find that the current noise of the
SSET is strongly influenced by the fluctuations in the resonator energy and
hence should provide a useful indicator of the resonator's dynamics.",0806.1441v2
2012-11-11,Resonances for activity waves in spherical mean field dynamos,"We study activity waves of the kind that determine cyclic magnetic activity
of various stars, including the Sun, as a more general physical rather than a
purely astronomical problem. We try to identify resonances which are expected
to occur when a mean-field dynamo excites waves of quasi-stationary magnetic
field in two distinct spherical layers. We isolate some features that can be
associated with resonances in the profiles of energy or frequency plotted
versus a dynamo governing parameter. Rather unexpectedly however the resonances
in spherical dynamos take a much less spectacular form than resonances in many
more familiar branches of physics. In particular, we find that the magnitudes
of resonant phenomena are much smaller than seem detectable by astronomical
observations, and plausibly any related effects in laboratory dynamo
experiments (which of course are not in gravitating spheres!) are also small.
We discuss specific features relevant to resonant phenomena in spherical
dynamos, and find parametric resonance to be the most pronounced type of
resonance phenomena. Resonance conditions for these dynamo wave resonances are
rather different from those for more conventional branches of physics. We
suggest that the relative insignificance of the phenomenon in this case is
because the phenomena of excitation and propagation of the activity waves are
not well-separated from each other and this, together with the nonlinear nature
of more-or-less realistic dynamos, suppress the resonances and makes them much
less pronounced than resonant effects, for example in optics.",1211.2414v1
2013-07-31,Discrete exact and quasi-resonances of Rossby/drift waves on $\b$-plane with periodic boundary conditions,"Analysis of resonance clustering in weakly nonlinear dispersive wave systems,
also called discrete wave turbulent systems, is a new methodology successfully
used in the last years for characterizing energy transport due to exact and
quasi-resonances. Quite recently this methodology has been used in the paper by
M. D. Bustamante, U. Hayat ""Complete classification of discrete resonant
Rossby/drift wave triads on periodic domains"", \cite{BH13}, in order to show
that resonance clustering is very sparse and quasi-resonances (that is,
resonances with small enough detuning) play major role in the energy transport
in this specific wave system. On the other hand, in the paper by M. Yamada, T.
Yoneda ""Resonant interaction of Rossby waves in two-dimensional flow on
$\beta$-plane"", \cite{YaYo13}, the same physical system is studied and a
mathematically rigorous theorem is proven: at high $\b$, the flow dynamics is
governed exclusively by resonant interactions. In our present paper we
demonstrate that this seeming contradiction between numerical results
\cite{BH13} and analytical results \cite{YaYo13} are due to some pitfalls in
numerical studies of exact and quasi-resonances presented in \cite{BH13}. We
also demonstrate that resonance clustering of drift waves on periodic
$\b$-plane differs substantially from characteristic resonance clustering in
other 3-wave systems: instead of a usual set of isolated triads and a few
bigger clusters, there exists \emph{no isolated triads} in this case. Resonant
triads are interconnected in a complicated way and the smallest cluster
consists of 6 connected triads.",1307.8272v1
2014-10-20,Resonance capture at arbitrary inclination,"Resonance capture is studied numerically in the three-body problem for
arbitrary inclinations. Massless particles are set to drift from outside the
1:5 resonance with a Jupiter-mass planet thereby encountering the web of the
planet's diverse mean motion resonances. Randomly constructed samples explore
parameter space for inclinations from 0 to 180 deg with 5deg increments
totalling nearly 6x10^5 numerical simulations. Thirty resonances internal and
external to the planet's location are monitored. We find that retrograde
resonances are unexpectedly more efficient at capture than prograde resonances
and that resonance order is not necessarily a good indicator of capture
efficiency at arbitrary inclination. Capture probability drops significantly at
moderate sample eccentricity for initial inclinations in the range
[10deg,110deg]. Orbit inversion is possible for initially circular orbits with
inclinations in the range [60deg,130deg]. Capture in the 1:1 coorbital
resonance occurs with great likelihood at large retrograde inclinations. The
planet's orbital eccentricity, if larger than 0.1, reduces the capture
probabilities through the action of the eccentric Kozai-Lidov mechanism. A
capture asymmetry appears between inner and outer resonances as prograde orbits
are preferentially trapped in inner resonances. The relative capture efficiency
of retrograde resonance suggests that the dynamical lifetimes of Damocloids and
Centaurs on retrograde orbits must be significantly larger than those on
prograde orbits implying that the recently identified asteroids in retrograde
resonance, 2006 BZ8, 2008 SO218, 2009 QY6 and 1999 LE31(Morais and Namouni,
2013, MNRAS 436, L30) may be among the oldest small bodies that wander between
the outer giant planets.",1410.5383v1
2015-07-07,Thermal Resonance Fusion,"We first show a possible mechanism to create a new type of nuclear fusion,
thermal resonance fusion, i.e. low energy nuclear fusion with thermal resonance
of light nuclei or atoms, such as deuterium or tritium. The fusion of two light
nuclei has to overcome the Coulomb barrier between these two nuclei to reach up
to the interacting region of nuclear force. We found nuclear fusion could be
realized with thermal vibrations of crystal lattice atoms coupling with light
atoms at low energy by resonance to overcome this Coulomb barrier. Thermal
resonances combining with tunnel effects can greatly enhance the probability of
the deuterium fusion to the detectable level. Our low energy nuclear fusion
mechanism research - thermal resonance fusion mechanism results demonstrate how
these light nuclei or atoms, such as deuterium, can be fused in the crystal of
metal, such as Ni or alloy, with synthetic thermal vibrations and resonances at
different modes and energies experimentally. The probability of tunnel effect
at different resonance energy given by the WKB method is shown that indicates
the thermal resonance fusion mode, especially combined with the tunnel effect,
is possible and feasible. But the penetrating probability decreases very
sharply when the input resonance energy decreases less than 3 keV, so for
thermal resonance fusion, the key point is to increase the resonance peak or
make the resonance sharp enough to the acceptable energy level by the suitable
compound catalysts, and it is better to reach up more than 3 keV to make the
penetrating probability larger than 10^{-10}.",1507.01650v1
2012-04-26,Higher Order Spin Resonances in a 2.1 GeV/c Polarized Proton Beam,"Spin resonances can depolarize or spin-flip a polarized beam. We studied 1st
and higher order spin resonances with stored 2.1 GeV/c vertically polarized
protons. The 1st order vertical ({\nu}y) resonance caused almost full
spin-flip, while some higher order {\nu}y resonances caused partial
depolarization. The 1st order horizontal ({\nu}x) resonance caused almost full
depolarization, while some higher order {\nu}x resonances again caused partial
depolarization. Moreover, a 2nd order {\nu}x resonance is about as strong as
some 3rd order {\nu}x resonances, while some 3rd order {\nu}y resonances are
much stronger than a 2nd order {\nu}y resonance. One thought that {\nu}y spin
resonances are far stronger than {\nu}x, and that lower order resonances are
stronger than higher order; the data do not support this.",1204.6002v1
2020-04-16,The onset of instability in resonant chains,"There is evidence that most chains of mean motion resonances of type
$k$:$k-1$ among exoplanets become unstable once the dissipative action from the
gas is removed from the system, particularly for large $N$ (the number of
planets) and $k$ (indicating how compact the chain is). We present a novel
dynamical mechanism that can explain the origin of these instabilities and thus
the dearth of resonant systems in the exoplanet sample. It relies on the
emergence of secondary resonances between a fraction of the synodic frequency
$2 \pi (1/P_1-1/P_2)$ and the libration frequencies in the mean motion
resonance. These secondary resonances excite the amplitudes of libration of the
mean motion resonances thus leading to an instability. We detail the emergence
of these secondary resonances by carrying out an explicit perturbative scheme
to second order in the planetary masses and isolating the harmonic terms that
are associated with them. Focusing on the case of three planets in the 3:2 --
3:2 mean motion resonance as an example, a simple but general analytical model
of one of these resonances is obtained which describes the initial phase of the
activation of one such secondary resonance. The dynamics of the excited system
is also briefly described. This scheme shows how one can obtain analytical
insight into the emergence of these resonances, and into the dynamics that they
trigger. Finally, a generalisation of this dynamical mechanism is obtained for
arbitrary $N$ and $k$. This leads to an explanation of previous numerical
experiments on the stability of resonant chains, showing why the critical
planetary mass allowed for stability decreases with increasing $N$ and $k$.",2004.07789v1
2018-03-14,Resonance Capture and Dynamics of 3-Planet Systems,"We present a series of dynamical maps for fictitious 3-planets systems in
initially circular coplanar orbits. These maps have unveiled a rich resonant
structure involving two or three planets, as well as indicating possible
migration routes from secular to double resonances or pure 3-planet
commensurabilities. These structures are then compared to the present-day
orbital architecture of observed resonant chains. In a second part of the paper
we describe N-body simulations of type-I migration. Depending on the orbital
decay timescale, we show that 3-planet systems may be trapped in different
combinations of independent commensurabilities: (i) double resonances, (ii)
intersection between a 2-planet and a first-order 3-planet resonance, and (iii)
simultaneous libration in two first-order 3-planet resonances. These latter
outcomes are found for slow migrations, while double resonances are almost
always the final outcome in high-density disks. Finally, we discuss an
application to the TRAPPIST-1 system. We find that, for low migration rates and
planetary masses of the order of the estimated values, most 3-planet
sub-systems are able to reach the observed double resonances after following
evolutionary routes defined by pure 3-planet resonances. The final orbital
configuration shows resonance offsets comparable with present-day values
without the need of tidal dissipation. For the 8/5 resonance proposed to
dominate the dynamics of the two inner planets, we find little evidence of its
dynamical significance; instead, we propose that this relation between mean
motions could be a consequence of the interaction between a pure 3-planet
resonance and a 2-planet commensurability between planets c and d.",1803.05305v1
2019-03-08,Perfect Absorption Metasurfaces with Multiple Meta-Resonances,"We show that the hybrid resonances of a DMR backed by a cavity are
meta-resonances, in that they can be made as perfect as possible by fine tuning
the structural parameters but without the requirements of extreme materials
properties, such as zero dissipation. Instead, dissipation in the DMR is
essential for the realization of perfect meta-resonances. We experimentally
demonstrate such perfection by tuning the structure of a HMR till its
reflection is as low as 0.426 % . Besides the primary meta-resonances that are
originated from the strong resonances of the DMR, weak hitchhiker resonances
can also produce meta-resonances as perfect as the primary ones. The depth of
the reflection dips is insensitive to the strength of the resonances involved,
but critically depends on the degree of impedance match to air brought mostly
by fine tuning the structure parameters, such as the cavity volume, the mass of
the platelet, or the pre-tension in the membrane. Using the eccentricity of the
platelet position in the DMR, a number of resonances and anti-resonances are
generated, resulting in up to five meta-resonances within the range of 200 Hz
to 1000 Hz, with the highest reflection being 7 % and the lowest being 1.2 % .
Other means of introducing hitchhiker meta-resonances are also reported.",1903.03493v2
2019-08-15,Connections between resonance and nonlinearity in swimming performance of a flexible heaving plate,"We investigate the role of resonance in finite-amplitude swimming of a
flexible flat plate in a viscous fluid. The role of resonance in performance
remains unclear for two reasons: i) a lack of definition of resonance for the
fully-coupled fluid-structure interaction system in a viscous flow, and ii) the
presence of nonlinear effects, which makes it difficult to disentangle resonant
and non-resonant mechanisms in finite-amplitude swimming. We address point i)
and provide an unambiguous definition for system resonance by computing global
linear stability modes of the fully-coupled fluid-structure interaction system
that account for the viscous fluid, the plate, and the coupling between them.
We then resolve point ii) by considering high-fidelity nonlinear simulations of
systematically increased amplitude. By comparing the results for different
amplitudes with one another and with the linear stability modes, we separate
linear and/or resonant effects from nonlinear and/or non-resonant effects.
Resonant behavior is observed over a wide range of plate stiffnesses, with
peaks in trailing-edge motion and thrust occurring near the resonant frequency
defined by the global linear analysis. The peaks broaden and weaken with
increasing heave amplitude, consistent with an increased damping effect from
the fluid. At the same time, non-resonant mechanisms are present at large heave
amplitudes. The input power exhibits qualitatively different dynamics at large
heave amplitudes compared to smaller heave amplitudes, where resonance
dominates. Moreover, leading-edge separation is present for stiff plates at
large heave amplitudes, which can drastically alter the performance
characteristics from what one would expect through linear predictions.",1908.05704v1
2020-10-06,Multi-harmonic Hamiltonian models with applications to first-order resonances,"In this work, two multi-harmonic Hamiltonian models for mean motion
resonances are formulated and their applications to first-order resonances are
discussed. For the $k_p$:$k$ resonance, the usual critical argument $\varphi =
k \lambda - k_p \lambda_p + (k_p - k) \varpi$ is taken as the resonant angle in
the first model, while the second model is characterized by a new critical
argument $\sigma = \varphi / k_p$. Based on canonical transformations, the
resonant Hamiltonians associated with these two models are formulated. It is
found that the second Hamiltonian model holds two advantages in comparison to
the first model: (a) providing a direct correspondence between phase portraits
and Poincar\'e sections, and (b) presenting new phase-phase structures where
the zero-eccentricity point is a visible saddle point. Then, the second
Hamiltonian model is applied to the first-order inner and outer resonances,
including the 2:1, 3:2, 4:3, 2:3 and 3:4 resonances. The phase-space structures
of these first-order resonances are discussed in detail and then the libration
centers and associated resonant widths are identified analytically. Simulation
results show that there are pericentric and apocentric libration zones where
the libration centers diverge away from the nominal resonance location as the
eccentricity approaches zero and, in particular, the resonance separatrices do
not vanish at arbitrary eccentricities for both the inner and outer
(first-order) resonances.",2010.02431v1
2022-04-12,Band-type resonance: non-discrete energetically-optimal resonant states,"Structural resonance involves the absorption of inertial loads by a tuned
structural elasticity: a process playing a key role in a wide range of
biological and technological systems, including many biological and
bio-inspired locomotion systems. Conventional linear and nonlinear resonant
states typically exist at specific discrete frequencies, and specific symmetric
waveforms. This discreteness can be an obstacle to resonant control modulation:
deviating from these states, by breaking waveform symmetry or modulating drive
frequency, generally leads to losses in system efficiency. Here, we demonstrate
a new strategy for achieving these modulations at no loss of energetic
efficiency. Leveraging fundamental advances in nonlinear dynamics, we
characterise a new form of structural resonance: band-type resonance,
describing a continuous band of energetically-optimal resonant states existing
around conventional discrete resonant states. These states are a counterexample
to the common supposition that deviation from a linear (or nonlinear) resonant
frequency necessarily involves a loss of efficiency. We demonstrate how
band-type resonant states can be generated via a spectral shaping approach:
with small modifications to the system kinematic and load waveforms, we
construct sets of frequency-modulated and symmetry-broken resonant states that
show equal energetic optimality to their conventional discrete analogues. The
existence of these non-discrete resonant states in a huge range of oscillators
- linear and nonlinear, in many different physical contexts - is a new
dynamical-systems phenomenon. It has implications not only for biological and
bio-inspired locomotion systems but for a constellation of forced oscillator
systems across physics, engineering, and biology.",2204.10409v1
2022-07-28,Chaotic diffusion of asteroids in the exterior 1:2 mean motion resonance with Mars,"The inner asteroid belt between 2.1 and 2.5 au is of particular dynamical
significance because it is the dominant source of both chondritic meteorites
and near-Earth asteroids. This inner belt is bounded by an eccentricity-type
secular resonance and by the 1:3 mean motion resonance with Jupiter. Unless
asteroid perihelia are low enough to allow scattering by Mars, escape requires
transport to one of the bounding resonances. In addition Yarkovsky forces are
generally ineffective in changing either the eccentricity and/or inclination
for asteroids with diameter $\gtrsim$30 km. Thus, large asteroids with
pericentres far from Mars may only escape from the inner belt through large
changes in their eccentricities. In this paper we study chaotic diffusion of
orbits near the 1:2 mean motion resonance with Mars in a systematic way. We
show that, while chaotic orbital evolution in both resonant and non-resonant
orbits increase the dispersion of the inclinations and eccentricities, it does
not significantly change their mean values. We show further that, while the
dispersive growth is greatest for resonant orbits, at high $e$ the resonance
acts to mitigate asteroid scattering by Mars - making the asteroid lifetime in
the belt longer than it would have been for a non-resonant orbit. For asteroids
of all sizes in both resonant and non-resonant orbits, the changes in
eccentricity needed to account for the observations cannot be achieved by
gravitational forces alone. The role of resonant trapping in protecting
asteroids from encounters with Mars is also analysed.",2207.14047v2
2024-03-03,Vibrational resonance: A review,"Over the past two decades, vibrational resonance has garnered significant
interest and evolved into a prominent research field. Classical vibrational
resonance examines the response of a nonlinear system excited by two signals: a
weak, slowly varying characteristic signal, and a fast-varying auxiliary
signal. The characteristic signal operates on a much longer time scale than the
auxiliary signal. Through the cooperation of the nonlinear system and these two
excitations, the faint input can be substantially amplified, showcasing the
constructive role of the fast-varying signal. Since its inception, vibrational
resonance has been extensively studied across various disciplines, including
physics, mathematics, biology, neuroscience, laser science, chemistry, and
engineering. Here, we delve into a detailed discussion of vibrational resonance
and the most recent advances, beginning with an introduction to characteristic
signals commonly used in its study. Furthermore, we compile numerous nonlinear
models where vibrational resonance has been observed to enhance readers'
understanding and provide a basis for comparison. Subsequently, we present the
metrics used to quantify vibrational resonance, as well as offer a theoretical
formulation. This encompasses the method of direct separation of motions,
linear and nonlinear vibrational resonance, re-scaled vibrational resonance,
ultrasensitive vibrational resonance, and the role of noise in vibrational
resonance. Later, we showcase two practical applications of vibrational
resonance: one in image processing and the other in fault diagnosis. This
presentation offers a comprehensive and versatile overview of vibrational
resonance, exploring various facets and highlighting promising avenues for
future research in both theory and engineering applications.",2403.06997v1
2013-07-31,A Vertical Resonance Heating Model for X- or Peanut-Shaped Galactic Bulges,"We explore a second order Hamiltonian vertical resonance model for X-shaped
or peanut-shaped galactic bulges. The X-shape is caused by the 2:1 vertical
Lindblad resonance with the bar, with two vertical oscillation periods per
orbital period in the bar frame. We examine N-body simulations and find that
due to the bar slowing down and disk thickening during bar buckling, the
resonance and associated peanut-shape moves outward. The peanut-shape is
consistent with the location of the vertical resonance, independent of whether
the bar buckled or not. We estimate the resonance width from the potential m=4
Fourier component and find that the resonance is narrow, affecting orbits over
a narrow range in the angular momentum distribution, dL/L ~ 0.05. As the
resonance moves outward, stars originally in the mid plane are forced out of
the mid plane into orbits just within the resonance separatrix. The height of
the separatrix orbits, estimated from the Hamiltonian model, is approximately
consistent with the peanut-shape height. The X-shape is comprised of stars in
the vicinity of the resonance separatrix. The velocity distributions from the
simulations illustrate that low inclination orbits are depleted within
resonance. Within resonance, the vertical velocity distribution is broad,
consistent with resonant heating caused by the passage of the resonance through
the disk. In the Milky Way bulge we relate the azimuthally averaged mid-plane
mass density near the vertical resonance to the rotation curve and bar pattern
speed. At an estimated vertical resonance galactocentric radius of ~1.3 kpc, we
confirm a mid-plane density of ~5x10^8 Msol/kpc^3, consistent with recently
estimated mass distributions. We find that the rotation curve, bar pattern
speed, 2:1 vertical resonance location, X-shape tips, and mid-plane mass
density, are all self-consistent in the Milky Way galaxy bulge.",1307.8441v2
2020-01-04,Long-term evolution of the Galilean satellites: the capture of Callisto into resonance,"Context. The strong tidal dissipation in the couple Jupiter-Io is spread to
all the moons involved in the Laplace resonance (Io, Europa, and Ganymede),
leading to a migration of their orbits.
  Aims. We aim to characterize the future behavior of the Galilean satellites
over the Solar System lifetime and to quantify the stability of the Laplace
resonance. Since tidal dissipation makes possible the exit from the current
resonances or capture into new ones, we investigate the capture of Callisto
into resonance.
  Methods. We perform hundreds of propagations using an improved version of a
recent semi-analytical model. As Ganymede moves outwards, it approaches the 2:1
resonance with Callisto, inducing a temporary chaotic motion in the system. For
this reason, we draw a statistical picture of the outcome of the resonant
encounter.
  Results. The system can settle into two distinct outcomes: A) a chain of
three 2:1 two-body resonances (Io-Europa, Europa-Ganymede and
Ganymede-Callisto), or B) a resonant chain involving the 2:1 two-body resonance
Io-Europa plus at least one pure 4:2:1 three-body resonance, most frequently
between Europa, Ganymede and Callisto. In case A (56\% of the simulations), the
Laplace resonance is always preserved and the eccentricities remain confined to
small values below 0.01. In case B (44\% of the simulations), the Laplace
resonance is generally disrupted and the eccentricities of Ganymede and
Callisto can increase up to about 0.1, making this configuration unstable and
driving the system into new resonances.
  Conclusion. From our results, the capture of Callisto into resonance appears
to be extremely likely (100\% of our simulations). Assuming the most recent
estimate of the dissipation between Io and Jupiter, the resonant encounter
happens at about 1.5 Gyrs from now. Therefore, the stability of the Laplace
resonance is guaranteed at least up to about 1.5 Gyrs.",2001.01106v2
2005-10-20,The autoparametric 3:2 resonance in conservative systems,"In the resonance model, high-frequency quasi-periodic oscillations (QPOs) are
supposed to be a consequence of nonlinear resonance between modes of
oscillations occurring within the innermost parts of an accretion disk. Several
models with a prescribed mode--mode interaction were proposed in order to
explain the characteristic properties of the resonance in QPO sources. In this
paper, we examine nonlinear oscillations of a system having two degrees of
freedom and we show that this case could be particularly relevant for QPOs. We
present a very convenient way how to study autoparametric resonances of a fully
general system using the method of multiple scales. We concentrate to
conservative systems and discuss their behavior near the 3:2 parametric
resonance.",0510605v1
1993-12-07,Resonance Lineshapes in Quasi-One-Dimensional Scattering,"An S matrix approach is developed to describe elastic scattering resonances
of systems where the scattered particle is asymptotically confined and the
scattering potential lacks continuous symmetry. Examples are conductance
resonances in microstructures or transmission resonances in waveguide
junctions. The generic resonance is shown to have the asymmetric Fano
lineshape. The asymmetry parameter q is independent of coupling to the
quasi-bound level implying a scaling property of the resonances which can be
tested in transport experiments.",9312033v1
2000-03-23,Resonant tunneling in GaAs/AlGaAs triple-barrier structures under uniform transverse magnetic field,"The effect of an in-plane magnetic field on resonant tunneling in a symmetric
GaAs/AlYGa1-YAs triple-barrier resonant tunneling TBRT structure is presented.
The splitting of the resonant lines (and hence the coupling energy vs. magnetic
induction) for the ground and the first excited resonant doublet shifts up in
energy by increasing the magnetic induction. Each of branches in the resonant
dispersion relations shows a parabolic behavior with the location of the
cyclotron orbit center. It is expected that, at very high fields, the
interaction with confined phonons be enhanced, due to phonon coupling between
electron states in the ground quasibound doublet.",0003373v1
2002-10-01,Tunable Molecular Resonances of Double Quantum Dots Embedded in an Aharonov-Bohm Interferometer,"We investigate resonant tunneling through molecular states of coupled double
quantum dots embedded in an Aharonov-Bohm (AB) interferometer. The conductance
through the system consists of two resonances associated with the bonding and
the antibonding quantum states. We predict that the two resonances are composed
of a Breit-Wigner resonance and a Fano resonance, those widths and Fano factor
depending on the AB phase very sensitively.
  Further, we point out that the bonding properties, such as the covalent and
the ionic bonding, can be identified by the AB oscillations.",0210009v1
2003-01-15,Quantum Measurement of a Coupled Nanomechanical Resonator -- Cooper-Pair Box System,"We show two effects as a result of considering the second-order correction to
the spectrum of a nanomechanical resonator electrostatically coupled to a
Cooper-pair box. The spectrum of the Cooper-pair box is modified in a way which
depends on the Fock state of the resonator. Similarly, the frequency of the
resonator becomes dependent on the state of the Cooper-pair box. We consider
whether these frequency shifts could be utilized to prepare the nanomechanical
resonator in a Fock state, to perform a quantum non-demolition measurement of
the resonator Fock state, and to distinguish the phase states of the
Cooper-pair box.",0301252v2
2003-08-29,Lifetime of molecule-atom mixtures near a Feshbach resonance in 40K,"We report a dramatic magnetic field dependence in the lifetime of trapped,
ultracold diatomic molecules created through an s-wave Feshbach resonance in
40K. The molecule lifetime increases from less than 1 ms away from the Feshbach
resonance to greater than 100 ms near resonance. We also have measured the
trapped atom lifetime as a function of magnetic field near the Feshbach
resonance; we find that the atom loss is more pronounced on the side of the
resonance containing the molecular bound state.",0308606v1
2004-04-02,Three-boson problem near a narrow Feshbach resonance,"We consider a three-boson system with resonant binary interactions and show
that three-body observables depend only on the resonance width and the
scattering length. The effect of narrow resonances is qualitatively different
from that of wide resonances revealing novel physics of three-body collisions.
We calculate the rate of three-body recombination to a weakly bound level and
the atom-dimer scattering length and discuss implications for experiments on
Bose-Einstein condensates and atom-molecule mixtures near Feshbach resonances.",0404036v2
2004-06-04,Observation of Feshbach resonances between two different atomic species,"We have observed three Feshbach resonances in collisions between lithium-6
and sodium-23 atoms. The resonances were identified as narrow loss features
when the magnetic field was varied. The molecular states causing these
resonances have been identified, and additional lithium-sodium resonances are
predicted. These resonances will allow the study of degenerate Bose-Fermi
mixtures with adjustable interactions, and could be used to generate ultracold
heteronuclear molecules.",0406129v1
2004-07-14,Feshbach Resonances in Fermionic Lithium-6,"Feshbach resonances in lithium-6 were experimentally studied and
theoretically analyzed. In addition to two previously known s-wave resonances,
we found three p-wave resonances. Four of these resonances are narrow and yield
a precise value of the singlet scattering length, but do not allow us to
accurately predict the location of the broad resonance near 83 mT. Its position
was previously measured in a molecule-dissociation experiment for which we,
here, discuss systematic shifts.",0407373v1
2004-12-28,Resonant plasmon scattering by discrete breathers in Josephson junction ladders,"We study the resonant scattering of plasmons (linear waves) by discrete
breather excitations in Josephson junction ladders. We predict the existence of
Fano resonances, and find them by computing the resonant vanishing of the
transmission coefficient. We propose an experimental setup of detecting these
resonances, and conduct numerical simulations which demonstrate the possibility
to observe Fano resonances in the plasmon scattering by discrete breathers in
Josephson junction ladders.",0412727v1
2006-08-03,High frequency study of the orbital ordering resonance in the strongly correlated heavy fermion metal CeB6,"We report results of the study of the recently discovered magnetic resonance
in the orbitally ordered phase of CeB6 (the orbital ordering resonance) in a
wide frequency range 44-360 GHz. It is found that the g-factor for this
resonance increases with frequency from g(44 GHz)~1.55 to g(>250 GHz)~1.7. In
addition to the orbital ordering resonance for the frequencies exceeding 200
GHz a new magnetic resonance with the g-factor 1.2-1.3 is detected.",0608079v1
1998-03-14,The Balmer-Like Formula for Mass Distribution of Elementary Particle Resonances,"Elementary particle resonances have been systematically analysed using all
available experimental data. We have come to the conclusion that the resonance
decay prodact momenta and masses of resonances are to be quantized. The Balmer-
like formula for masses of elementary particle resonances was obtained. These
observations allow us to formulate a strategy of experimental searches for new
resonances and systematize the known one.",9803352v2
2001-04-25,How parametric resonance mechanism follows quench mechanism in disoriented chiral condensate,"We show how parametric resonance mechanism follows quench mechanism in the
classical linear sigma model. The parametric resonance amplifies long
wavelength modes of the pion for more than $10 fm/c$. The shifting from the
quench mechanism to the parametric resonance mechanism is described by a time
dependent quantity. After the quench mechanism is over, that quantity has an
oscillating part, which causes the parametric resonance. Since its frequency is
$2 m_\pi ~(m_\pi$ : pion mass), very long wavelength modes such as k = 40 MeV
of the pion are amplified by the parametric resonance.",0104255v1
2001-10-05,Two-photon mediated resonance production in e+e- collisions: cross sections and density matrices,"Earlier described model amplitudes are used in this paper to evaluate both
cross sections and density matrices for two-photon mediated resonance
production in e^+e^- collisions. All 25 q\bar{q} low-lying ^1S_0, ^3P_J and
^1D_2 resonances can thus be treated. Two independent methods are described to
obtain the resonance production density matrices and cross sections. These
density matrices combined with a resonance decay density matrix give the
detailed angular distributions of the resonance decay products. For two
particular decays, \chi_{c2},\chi_{c1}\to\gamma J/\psi the details are given.
Several numerical results are presented as well.",0110086v1
2006-07-21,Resonance Production in Heavy Ion Collisions - what can we learn from RHIC?,"In these proceedings we concentrate on the refeeding and rescattering
probability of hadronic resonances. We discuss the probability to form
resonances in binary baryon-meson or meson-meson collisions as a function of
time for various resonances using a transport model approach (UrQMD). We give
an estimate of the re-feeding probability using a simplified thermal approach
and discuss the relevance for the resonance/non-resonance ratio measured by
STAR.",0607242v3
2007-02-05,Stochastic Resonance: from climate to biology,"In this paper I will review some basic aspects of the mechanism of stochastic
resonance. Stochastic resonance was first introduced as a possible mechanism to
explain long term climatic variation. Since then, there have been many
applications of stochastic resonance in physical and biological systems. I will
show that in complex system, stochastic resonance can substantially change as a
function of the ``system complexity''. Also, I will briefly mention how to
apply stochastic resonance for the case of Brownian motors.",0702008v1
1995-11-30,Do we have three $S_{11}$ resonances in the second resonance region?,"We review the status of the $S_{11}$ N$^*$ resonances in light of some recent
theoretical and phenomenological results. Whereas the quark model predicts two
such resonances around 1.6 GeV, there is considerable evidence for a third
$S_{11}$ resonance in this energy range. This suggests that a $K\Sigma$ or
$K\Lambda$ quasi-bound state may indeed exist below the kaon production
threshold. We show that kaon production experiments, in particular $K^0$
photoproduction off nucleons, would be very sensitive to the existence of the
third $S_{11}$ resonance.",9511041v1
2000-10-31,Few-body resonances in light nuclei,"We have localized several few-body resonances in light nuclei, using methods
which can properly handle two- or three-body resonant states. Among other
results, we predict the existence of a three-neutron resonance, small
spin-orbit splittings between the low-lying states in He-5 and Li-5, the
nonexistence of the soft dipole resonance in He-6, new 1+ states in Li-8 and
B-8, and the presence of a nonlinear amplification phenomenon in the 0+_2 state
of C-12.",0010105v1
2004-11-18,Nuclear giant resonances,"This talk presents the recent status of theoretical and experimental studies
of giant resonances in nuclei with the emphasis on: (1) charge-exchange
Gamow-Teller resonance, (2) multiple-phonon resoanances, (3) giant dipole
resonances in highly excited nuclei, and (4) pygmy dipole resonances in neutron
rich nuclei. In particular, the description of these resonances within the
framework of the phonon damping model is discussed in detail.",0411073v1
2006-10-24,Negative Energy Resonances of Bosons in a Magnetic Quadrupole Trap,"We investigate resonances of spin 1 bosons in a three-dimensional magnetic
quadrupole field. Complementary to the well-known positive energy resonances it
is shown that there exist short-lived, i.e. broad, negative energy resonances.
The latter are characterized by an atomic spin that is aligned antiparallel to
the local magnetic field direction. In contrast to the positive energy
resonances the lifetimes of the negative energy resonances decreases with
increasing total magnetic quantum number. We derive a mapping of the two
branches of the spectrum.",0610207v1
2007-06-05,Resonance Production in RHIC Collisions,"Results of resonance particle production measured at RHIC in $\sqrt{s_{\rm
NN}} = $ 200 GeV Au+Au collisions are compared to measurements in p+p and d+Au
collisions in order to verify the existence of an extended hardronically
interacting medium. Yield and momentum distributions of resonances maybe
modified during the fireball lifetime due to resonance decay and the subsequent
rescattering of their decay daughters as well as the regeneration of resonances
from their decay products. Modified momentum spectra in heavy ion collisions
may change the nuclear modification factor R$_{\rm AA}$. The influence on the
elliptic flow v$_{2}$ due to late regeneration of resonances is discussed.",0706.0729v1
2007-09-05,Electron spin manipulation and resonator readout in a double quantum dot nano-electromechanical system,"Magnetically coupling a nano-mechanical resonator to a double quantum dot
confining two electrons can enable the manipulation of a single electron spin
and the readout of the resonator's natural frequency. When the Larmor frequency
matches the resonator frequency, the electron spin in one of the dots can be
selectively flipped by the magnetised resonator. By simultaneously measuring
the charge state of the two-electron double quantum dots, this transition can
be detected thus enabling the natural frequency of the mechanical resonator to
be determined.",0709.0593v2
2007-09-09,Strongly Resonant Transmission of Electromagnetic Radiation in Periodic Anisotropic Layered Media,"The electromagnetic dispersion in periodic layered media can be tailored and
their resonant properties can be considerably improved by utilizing anisotropic
materials. Periodic structures with a photonic band edge split into two parts,
or so-called split band edge, exhibit superior resonant properties including
exceptionally high Q-values of transmission resonances and nearly perfect
impedance matching at the boundaries, even when the number of unit cells N is
not large. A microwave transmission resonance with Q~220 is demonstrated in a
periodic stack of form-birefringent layers with N=12 realized in a waveguide
geometry.",0709.1250v2
2008-02-07,How Resonances can synchronise with Thresholds,"The mechanism by which a threshold may capture a resonance is examined. It
involves a threshold cusp interfering constructively with either or both (i) a
resonance produced via confinement, (ii) attractive t- and u-channel exchanges.
The fo(980), X(3872) and Z(4430) are studied in detail. The fo(980) provides a
valuable model of the locking mechanism. The X(3872) is too narrow to be fitted
by a cusp, and requires either a resonance or virtual state. The Z(4430) can be
fitted as a resonance but also can be fitted successfully by a cusp with no
nearby resonant pole.",0802.0934v2
2008-04-07,Nuclear-resonant electron scattering,"We investigate nuclear-resonant electron scattering as occurring in the
two-step process of nuclear excitation by electron capture (NEEC) followed by
internal conversion. The nuclear excitation and decay are treated by a
phenomenological collective model in which nuclear states and transition
probabilities are described by experimental parameters. We present capture
rates and resonant strengths for a number of heavy ion collision systems
considering various scenarios for the resonant electron scattering process. The
results show that for certain cases resonant electron scattering can have
significantly larger resonance strengths than NEEC followed by the radiative
decay of the nucleus. We discuss the impact of our findings on the possible
experimental observation of NEEC.",0804.0950v1
2008-04-22,Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators,"We study NbTiN resonators by measurements of the temperature dependent
resonance frequency and frequency noise. Additionally, resonators are studied
covered with SiOx dielectric layers of various thicknesses. The resonance
frequency develops a non-monotonic temperature dependence with increasing SiOx
layer thickness. The increase in the noise is independent of the SiOx
thickness, demonstrating that the noise is not dominantly related to the low
temperature resonance frequency deviations.",0804.3499v2
2009-03-23,Three Resonant Ultra-Cold Bosons: Off-Resonance Effects,"We solve a finite range two-channel model for three resonant identical
bosons. The model provides a minimal description of the various magnetic
Feshbach resonances in single species ultra-cold bosonic systems, including
off-resonant scattering. We obtain important insights into the interpretation
of seminal experiments: the three-body recombination rate measured in Sodium
and the Efimov resonances observed in Caesium. This approach quantifies non
universal effects appearing for a finite magnetic field detuning.",0903.3808v3
2009-06-06,Efficient readout of micromechanical resonator arrays in ambient conditions,"We present a method for efficient spectral readout of mechanical resonator
arrays in dissipative environments. Magnetomotive drive and detection is used
to drive double clamped resonators in the nonlinear regime. Resonators with
almost identical resonance frequencies can be tracked individually by sweeping
the drive power. Measurements are performed at room temperature and atmospheric
pressure. These conditions enable application in high throughput resonant
sensor arrays.",0906.1304v1
2009-07-16,Anharmonicity Induced Resonances for Ultracold Atoms and their Detection,"When two atoms interact in the presence of an anharmonic potential, such as
an optical lattice, the center of mass motion cannot be separated from the
relative motion. In addition to generating a confinement-induced resonance (or
shifting the position of an existing Feshbach resonance), the external
potential changes the resonance picture qualitatively by introducing new
resonances where molecular excited center of mass states cross the scattering
threshold. We demonstrate the existence of these resonances, give their
quantitative characterization in an optical superlattice, and propose an
experimental scheme to detect them through controlled sweeping of the magnetic
field.",0907.2906v2
2009-07-17,Resonance production from jet fragmentation,"Short lived resonances are sensitive to the medium properties in heavy-ion
collisions. Heavy hadrons have larger probability to be produced within the
quark gluon plasma phase due to their short formation times. Therefore heavy
mass resonances are more likely to be affected by the medium, and the
identification of early produced resonances from jet fragmentation might be a
viable option to study chirality. The high momentum resonances on the away-side
of a triggered di-jet are likely to be the most modified by the partonic or
early hadronic medium. We will discuss first results of triggered
hadron-resonance correlations in Cu+Cu heavy ion collisions.",0907.3161v1
2009-09-14,Distribution of Resonant Eigenvalues of Quantum Potential Scattering,"We formulate the Born approximation for finding resonance poles in the
complex plane for potential scattering problems. Using the method, we study the
distribution of resonance poles for several scattering potentials. In
particular, we find for an exponential potential with a cutoff that the cutoff
generates an infinite series of extra resonance poles below and along the real
axis, which would not exist without the cutoff. We also find for a Gaussian
potential that the series of resonance poles approach the imaginary axis of the
complex energy plane from left. In other words, the real parts of the resonant
eigenenergis are all negative.",0909.2463v1
2009-09-18,Random terahertz metamaterials,"Using terahertz time domain spectroscopy we investigate the normal incidence
transmission through periodically and randomly arranged planar split ring
resonators (SRRs). Introduction of positional disorder in metamaterials has no
effect on the quality factor of the fundamental Inductive-Capacitive (LC)
resonance. The dipole resonances undergo broadening and shift in their
resonance frequencies. The experiment reveals that the randomly distributed SRR
structures interact incoherently at LC resonance but couple coherently at the
higher frequency dipole resonance.",0909.3539v1
2009-11-16,Reducing microwave loss in superconducting resonators due to trapped vortices,"Microwave resonators with high quality factors have enabled many recent
breakthroughs with superconducting qubits and photon detectors, typically
operated in shielded environments to reduce the ambient magnetic field.
Insufficient shielding or pulsed control fields can introduce vortices, leading
to reduced quality factors, although increased pinning can mitigate this
effect. A narrow slot etched into the resonator surface provides a
straightforward method for pinning enhancement without otherwise affecting the
resonator. Resonators patterned with such a slot exhibited over an order of
magnitude reduction in the excess loss due to vortices compared with identical
resonators from the same film with no slot.",0911.3131v1
2010-01-22,Ultracompact plasmonic racetrack resonators in metal-insulator-metal waveguides,"Among various plasmonic waveguides, the metal-insulator-metal (MIM) type is
the most promising for true subwavelength photonic integration. To date, many
photonic devices based on MIM waveguides have been investigated, including
resonators. However, most of the reported MIM ring resonators suffer from low
extinction ratios. In this paper, we present a comprehensive analysis of the
intrinsic reasons for the low performance of MIM ring resonators, and give the
analytical transmission relation for a universal all-pass ring resonator which
has coupling loss. Based on the analysis we propose the plasmonic racetrack
resonators in MIM waveguides and show that the performance can be greatly
improved.",1001.4052v2
2010-01-28,Study of nucleon resonances at EBAC@JLab,"We present the dynamical origin of the P11 nucleon resonances resulting from
a dynamical coupled-channels (DCC) analysis of meson production reactions off a
nucleon target, which is conducted at Excited Baryon Analysis Center (EBAC) of
Jefferson Lab. Two resonance poles are found in the energy region where the
Roper resonance P11(1440) was identified. Furthermore, the two resonance poles
and the next higher resonance pole corresponding to P11(1710) are found to
originate from a single bare state.",1001.5080v1
2010-07-06,Detecting molecules with plasmonic resonators - Analytic expressions and bounds for the sensitivity and figure of merit,"We derive analytic expressions for the sensitivity and figure of merit for
refractive index sensing with plasmonic resonators in the quasistatic limit.
Based on these expressions the limits of detection and their origins are
investigated. The critical role of limited energy concentration within the
resonators surrounding is shown. The classical figure of merit is found to be
solely dependent on the ratio of real to imaginary part of the resonators
permittivity . Based on these findings we discuss the optimum resonance
wavelength and resonator size and shape for single molecule detection.",1007.0837v1
2010-07-21,Dynamics of Morphology-Dependent Resonances by Openness in Dielectric Disk for TE polarization,"We have studied the dynamics of morphology-dependent resonances by openness
in a dielectric microdisk for TE polarization. For the first time, we report
that the dynamics exhibits avoided resonance crossings between inner and outer
resonances even though the corresponding billiard is integrable. Due to the
avoidance, inner and outer resonances can be exchanged and $Q$-factor of inner
resonances is strongly affected. We analyze the diverse phenomena aroused from
the dynamics including the avoided crossings.",1007.3590v2
2010-07-22,Chiral dynamics and baryon resonances,"The structure of baryon resonance in coupled-channel meson-baryon scattering
is studied from the viewpoint of chiral dynamics. The meson-baryon scattering
amplitude can be successfully described together with the properties of the
resonance in the scattering, by implementing the unitarity condition for the
amplitude whose low energy structure is constrained by chiral theorem.
Recently, there have been a major progress in the study of the structure of the
resonance in chiral dynamics. We review the methods to clarify the structure of
the resonance by focusing on the Lambda(1405) resonance.",1007.3912v1
2010-10-28,Capacitive Spring Softening in Single-Walled Carbon Nanotube Nanoelectromechanical Resonators,"We report the capacitive spring softening effect observed in single-walled
carbon nanotube (SWNT) nanoelectromechanical (NEM) resonators. The nanotube
resonators adopt dual-gate configuration with both bottom-gate and side-gate
capable of tuning the resonance frequency through capacitive coupling.
Interestingly, downward resonance frequency shifting is observed with
increasing side-gate voltage, which can be attributed to the capacitive
softening of spring constant. Furthermore, in-plane vibrational modes exhibit
much stronger spring softening effect than out-of-plan modes. Our dual-gate
design should enable the differentiation between these two types of vibrational
modes, and open up new possibility for nonlinear operation of nanotube
resonators.",1010.6099v1
2011-01-10,Resonances On-Demand for Plasmonic Nano-Particles,"A method for designing plasmonic particles with desired resonance spectra is
presented. The method is based on repetitive perturbations of an initial
particle shape while calculating the eigenvalues of the various quasistatic
resonances. The method is rigorously proved, assuring a solution exists for any
required spectral resonance location. Resonances spanning the visible and the
near-infrared regimes, as designed by our method, are verified using
finite-difference time-domain simulations. A novel family of particles with
collocated dipole-quadrupole resonances is designed, demonstrating the unique
power of the method. Such on-demand engineering enables strict realization of
nano-antennas and metamaterials for various applications requiring specific
spectral functions.",1101.1769v1
2011-02-28,Resonant d-wave scattering in harmonic waveguides,"We observe and analyze d-wave resonant scattering of bosons in tightly
confining harmonic waveguides. It is shown that the d-wave resonance emerges in
the quasi-1D regime as an imprint of a 3D d-wave shape resonance. A scaling
relation for the position of the d-wave resonance is provided. By changing the
trap frequency, ultracold scattering can be continuously tuned from s-wave to
d-wave resonant behavior. The effect can be utilized for the realization of
ultracold atomic gases interacting via higher partial waves and opens a novel
possibility for studying strongly correlated atomic systems beyond s-wave
physics.",1102.5686v2
2011-04-22,Semiclassical Szego limit of resonance clusters for the hydrogen atom Stark Hamiltonian,"We study the weighted averages of resonance clusters for the hydrogen atom
with a Stark electric field in the weak field limit. We prove a semiclassical
Szego-type theorem for resonance clusters showing that the limiting
distribution of the resonance shifts concentrates on the classical energy
surface corresponding to a rescaled eigenvalue of the hydrogen atom
Hamiltonian. This result extends Szego-type results on eigenvalue clusters to
resonance clusters. There are two new features in this work: first, the study
of resonance clusters requires the use of non self-adjoint operators, and
second, the Stark perturbation is unbounded so control of the perturbation is
achieved using localization properties of coherent states corresponding to
hydrogen atom eigenvalues.",1104.4466v1
2011-05-12,Ab initio theory of Fano resonances in plasmonic nanostructures and metamaterials,"An ab initio theory for Fano resonances in plasmonic nanostructures and
metamaterials is developed using Feshbach formalism. It reveals the role played
by the electromagnetic modes and material losses in the system, and enables the
engineering of Fano resonances in arbitrary geometries. A general formula for
the asymmetric resonance in a non-conservative system is derived. The influence
of the electromagnetic interactions on the resonance line shape is discussed
and it is shown that intrinsic losses drive the resonance contrast, while its
width is mostly determined by the coupling strength between the non-radiative
mode and the continuum. The analytical model is in perfect agreement with
numerical simulations.",1105.2503v1
2011-05-30,Analytic description of atomic interaction at ultracold temperatures II: Scattering around a magnetic Feshbach resonance,"Starting from a multichannel quantum-defect theory, we derive analytic
descriptions of a magnetic Feshbach resonance in an arbitrary partial wave $l$,
and the atomic interactions around it. An analytic formula, applicable to both
broad and narrow resonances of arbitrary $l$, is presented for ultracold atomic
scattering around a Feshbach resonance. Other related issues addressed include
(a) the parametrization of a magnetic Feshbach resonance of arbitrary $l$, (b)
rigorous definitions of ""broad"" and ""narrow"" resonances of arbitrary $l$ and
their different scattering characteristics, and (c) the tuning of the effective
range and the generalized effective range by a magnetic field.",1105.5846v1
2011-07-01,Quasi-particle continuum and resonances in the Hartree-Fock-Bogoliubov theory,"The quasi-particle energy spectrum of the Hartree-Fock-Bogoliubov (HFB)
equations contains discrete bound states, resonances, and non-resonant
continuum states. We study the structure of the unbound quasi-particle spectrum
of weakly bound nuclei within several methods that do not rely on imposing
scattering or outgoing boundary conditions. Various approximations are examined
to estimate resonance widths. It is shown that the stabilization method works
well for all HFB resonances except for very narrow ones.
  The Thomas-Fermi approximation to the non-resonant continuum has been shown
to be very effective, especially for coordinate-space HFB calculations in large
boxes that involve huge amounts of discretized quasi-particle continuum states.",1107.0274v1
2011-09-01,Effects of mutual coupling in dual-resonance metamaterials,"This Letter presents an investigation on the effects of mutual coupling in a
metamaterial comprising two sets of electric-LC (ELC) resonators with different
resonance frequencies. Through simulation and experiment, it is found that the
two resonances experience significant shifting and weakening as they become
spectrally close. An equivalent circuit model suggests that inductive coupling
among the two resonator sets is a primary cause of the change in the resonance
properties. This study is fundamental to designing metamaterials with an
extended bandwidth or spatially variable response.",1109.0055v1
2011-09-20,Optically-gated resonant emission in single quantum dots,"We report on the resonant emission in coherently-driven single semiconductor
quantum dots. We demonstrate that an ultra-weak non-resonant laser acts as an
optical gate for the quantum dot resonant response. We show that the gate laser
suppresses Coulomb blockade at the origin of a resonant emission quenching, and
that the optically-gated quantum dots systematically behave as ideal two-level
systems in both regimes of coherent and incoherent resonant emission.",1109.4304v1
2011-12-03,Microwave-induced DC Signal in a Permalloy Thin Strip at Low Applied Magnetic Field,"We investigated the ferromagnetic resonance signals in a polycrystalline
permalloy thin strip under in-plane low static magnetic field. A series of DC
voltages, which contain ferromagnetic resonance or spin wave resonance signals,
were measured by inducing microwave frequencies greater than 10 gigahertz. The
resonant signals measured in low magnetic field show different properties from
those detected in high field condition. Based on the theory of DC effects in
ferromagnetic resonance and the experimental data of anisotropic
magnetoresistance, a quantitative model was proposed. We found that the shape
anisotropy significantly affects magnetization, and distorts the resonant
signals in low field condition.",1112.0610v1
2012-09-12,Simulating many-body lattice systems on a single nano-mechanical resonator,"We show that lattice systems, such as the Bose-Hubbard model, can be
simulated on a single nano- or micro-mechanical resonator, by exploiting its
many modes. The on-site Hamiltonians are engineered by coupling the mechanical
modes to the modes of a pair of optical or stripline resonators, and the
connections between the lattice sites are engineered in a similar way. The
lattice network structure is encoded in the frequency components of the fields
driving the resonators. This three-resonator configuration also allows
universal quantum computing on the nano-resonator.",1209.2499v1
2012-09-25,Analysis of light scattering off photonic crystal slabs in terms of Feshbach resonances,"Techniques to deal with Feshbach resonances are applied to describe resonant
light scattering off one dimensional photonic crystal slabs. Accurate
expressions for scattering amplitudes, free of any fitting parameter, are
obtained for isolated as well as overlapping resonances. They relate the
resonance properties to the properties of the optical structure and of the
incident light. For the most common case of a piecewise constant dielectric
function, the calculations can be carried out essentially analytically. After
establishing the accuracy of this approach we demonstrate its potential in the
analysis of the reflection coefficients for the diverse shapes of overlapping,
interacting resonances.",1209.5648v1
2013-01-27,"Cavity piezooptomechanics: piezoelectrically excited, optically transduced optomechanical resonators","We present a monolithic integrated aluminum nitride (AlN) optomechanical
resonator in which the mechanical motion is actuated by piezoelectric force and
the displacement is transduced by a high-Q optical cavity. The AlN
optomechanical resonator is excited from a radio-frequency electrode via a
small air gap to eliminate resonator-to-electrode loss. We observe the
electrically excited mechanical motion at 47.3 MHz, 1.04 GHz, and 3.12 GHz,
corresponding to the 1st, 2nd, and 4th radial-contour mode of the wheel
resonator respectively. An equivalent circuit model is developed to describe
the observed Fano-like resonance spectrum.",1301.6333v1
2013-03-26,Resonance asymptotics for Schrodinger operators on hyperbolic space,"We study the asymptotic distribution of resonances for scattering by
compactly supported potentials in hyperbolic space. We first establish an upper
bound for the resonance counting function that depends only on the dimension
and the support of the potential. We then establish the sharpness of this
estimate by proving the a Weyl law for the resonance counting function holds in
the case of radial potentials vanishing to some finite order at the edge of the
support. As an application of the existence of potentials that saturate the
upper bound, we derive additional resonance asymptotics that hold in a suitable
generic sense. These generic results include asymptotics for the resonance
count in sectors.",1303.6660v1
2013-07-29,Counter operation in nonlinear micro-electro-mechanical resonators,"This paper discusses a logical operation of multi-memories that consist of
coupled nonlinear micro-electro-mechanical systems (MEMS) resonators. A MEMS
resonator shows two coexisting stable states when nonlinear responses appear.
Previous studies addressed that a micro- or nano-electrical-mechanical
resonator can be utilized as a mechanical 1-bit memory or mechanical logic
gates. The next phase is the development of logic system with coupled
multi-resonators. From the viewpoint of application of nonlinear dynamics in
coupled MEMS resonators, we show the first experimental success of the
controlling nonlinear behavior as a 2-bit binary counter.",1307.7575v1
2013-12-14,Plasmon resonance and heat generation model in nanostructures,"In this paper, we investigate the photothermal effects of the plasmon
resonance. Metal nanoparticles efficiently generate heat in the presence of
electromagnetic radiation. The process is strongly enhanced when a fixed
frequency of the incident wave illuminate on nanoprticles such that plasmon
resonance happen. We shall introduce the electromagnetic radiation model and
show exactly how and when the plasmon resonance happen. We then construct the
heat generation and transfer model and derive the heat effect induced by
plasmon resonance. Finally, we consider the heat generation under plasmon
resonance in a concentric nanoshell structure.",1312.3994v1
2014-04-02,Crystalline Whispering Gallery Mode Resonators: In Search of The Optimal Material,"Different applications of crystalline whispering gallery mode resonators call
for different properties of the resonator host material. We report on our
recent study of resonators made out of sapphire, diamond, and quartz crystals
and discuss possible applications of these resonators. In particular, we
demonstrate Kerr frequency comb generation in sapphire microresonators.",1404.0426v1
2015-03-28,Hyperbolic Resonances of Metasurface Cavities,"We propose a new class of optical resonator structures featuring one or two
metasurface reflectors or metacavities and predict that such resonators support
novel hyperbolic resonances. As an example of such resonances we introduce
hyperbolic Tamm plasmons (HTPs) and hyperbolic Fabry-Perot resonances (HFPs).
The hyperbolic optical modes feature low-loss incident power re-distribution
over TM and TE polarization output channels, clover-leaf anisotropic
dispersion, and other unique properties which are tunable and are useful for
multiple applications.",1503.08260v1
2015-04-27,Overcoming limitations of nanomechanical resonators with simultaneous resonances,"Dynamic stabilization by simultaneous primary and superharmonic resonances
for high order nonlinearity cancellation is demonstrated with an
electrostatically-actuated, piezoresistively-transduced nanomechanical
resonator. We prove experimentally how the combination of both the third-order
nonlinearity cancellation and simultaneous resonances can be used to linearly
drive a nanocantilever up to very large amplitudes compared to fundamental
limits like pull-in occurrence, opening the way towards resonators with high
frequency stability for high-performance sensing or time reference.",1504.07533v1
2015-05-18,Improving LHC searches for strong EW symmetry breaking resonances,"Composite Higgs models generically predict the existence of heavy spin-1
resonances with the same quantum numbers as electroweak gauge bosons. The
effective lagrangian description of these resonances is presented, pointing out
the origin of their interactions with SM matter fields and the resulting LHC
phenomenology. Search strategies for spin-1 resonances are discussed,
mentioning possible advantages offered by boosted decay products. The impact of
interactions between spin-1 resonances and fermion resonances, crucial for the
proper interpretation of LHC searches, is pointed out.",1505.04645v2
2015-07-03,Symmetric and Standard Matter-Neutrino Resonances Above Merging Compact Objects,"Matter-neutrino resonances (MNR) can occur in environments where the flux of
electron antineutrinos is greater than the flux of electron neutrinos. These
resonances may result in dramatic neutrino flavor transformation. Compact
object merger disks are an example of an environment where electron
antineutrinos outnumber neutrinos. We study MNR resonances in several such disk
configurations and find two qualitatively different types of matter-neutrino
resonances: a standard MNR and a symmetric MNR. We examine the transformation
that occurs in each type of resonance and explore the consequences for
nucleosynthesis.",1507.00946v1
2015-07-14,Graphene fish-scale array as controllable reflecting photonic structure,"We report resonant features of novel controllable reflectarray which consists
of meander-like graphene strips placed on a metal-backed dielectric substrate.
The structure manifests two kinds of resonances appeared as sharp deeps of
reflectivity. The first one exists because the strips of periodic cells of the
structure have resonant sizes for induced surface plasmon-polaritons. The
second kind of resonances is defined by excitation of TM eigenwaves of the
whole structure as a plane photonic crystal. The latter resonances do not
depend on whether the strips of the unit cells have resonant sizes or not.",1507.03950v1
2015-11-02,Engineering Photonic Floquet Hamiltonians through Fabry Pérot Resonators,"In this letter we analyze an optical Fabry-P\'erot resonator as a
time-periodic driving of the (2D) optical field repeatedly traversing the
resonator, uncovering that resonator twist produces a synthetic magnetic field
applied to the light within the resonator, while mirror aberrations produce
relativistic dynamics, anharmonic trapping, and spacetime curvature. We develop
a Floquet formalism to compute the effective Hamiltonian for the 2D field,
generalizing the idea that the intra-cavity optical field corresponds to an
ensemble of non-interacting, massive, harmonically trapped particles. This work
illuminates the extraordinary potential of optical resonators for exploring the
physics of quantum fluids in gauge fields and exotic space-times.",1511.00595v1
2015-11-11,Can we trust the relationship between resonance poles and lifetimes?,"We show that the shape resonances induced by a one dimensional well of delta
functions disappear as soon as a small constant electric field is applied. In
particular, in any compact subset below the positive real axis there are no
resonances if the non-zero field is small enough. In contrast to the lack of
convergence of the lifetimes computed from the widths of the resonances we show
that the ""experimental lifetimes"" are continuous at zero field. The shape
resonances are replaced by an infinite set of other resonances whose location
and number we analyze.",1511.03724v1
2016-01-25,Cryogenic resonator design for trapped ion experiments in Paul traps,"Trapping ions in Paul traps requires high radio-frequency voltages, which are
generated using resonators. When operating traps in a cryogenic environment, an
in-vacuum resonator showing low loss is crucial to limit the thermal load to
the cryostat. In this study, we present a guide for the design and production
of compact, shielded cryogenic resonators. We produced and characterized three
different types of resonators and furthermore demonstrate efficient impedance
matching of these resonators at cryogenic temperatures.",1601.06699v1
2016-07-08,Resonant electron-phonon-electron interaction,"The effect of the resonance of electron scattering energy difference and
phonon energy on the electron-phonon-electron interaction (EPEI) is studied.
Results show that the resonance of electron transition energy and phonon energy
can enhance EPEI by a magnitude of 1 to 2. Moreover, the anisotropic S-wave
electron or dx2-y2 electron can enhance resonance EPEI, and the self-energy
correction of the electron will weaken resonance EPEI. Particularly, the
asymmetrical spin-flip scattering process in k space can reduce the effect of
electronic self-energy to enhance resonance EPEI",1607.02338v1
2016-09-19,Linear spreading speeds from nonlinear resonant interaction,"We identify a new mechanism for propagation into unstable states in spatially
extended systems, that is based on resonant interaction in the leading edge of
invasion fronts. Such resonant invasion speeds can be determined solely based
on the complex linear dispersion relation at the unstable equilibrium, but rely
on the presence of a nonlinear term that facilitates the resonant coupling. We
prove that these resonant speeds give the correct invasion speed in a simple
example, we show that fronts with speeds slower than the resonant speed are
unstable, and corroborate our speed criterion numerically in a variety of model
equations, including a nonlocal scalar neural field model.",1609.05757v1
2017-02-02,Physical properties of resonances as the building blocks of multichannel scattering amplitudes,"We propose a simple formula for multichannel resonant scattering with
parameters related to physical resonant properties. It can be used to predict
residue phase from other resonant parameters and describe the shape of
scattering amplitudes close to the resonance without any background
contributions or fitting. It works well even for overlapping resonances.
Imposing unitarity to the proposed formula enabled us to explain some puzzling
features of much more advanced models.",1702.00659v1
2018-02-02,Nonlinear resonances in the $ABC$-flow,"In this paper we study resonances of the $ABC$-flow in the near integrable
case ($C\ll 1$). This is an interesting example of a Hamiltonian system with
3/2 degrees of freedom in which simultaneous existence of two resonances of the
same order is possible. Analytical conditions of the resonance existence are
received. It is shown numerically that the largest $n:1$ ($n=1,2,3$) resonances
exist, and their energies are equal to theoretical energies in the near
integrable case. We provide analytical and numerical evidences for existence of
two branches of the two largest $n:1$ ($n=1,2$) resonances in the region of
finite motion.",1802.00557v1
2017-04-03,Resonances for Euler-Bernoulli operator on the half-line,"We consider resonances for fourth order differential operators on the
half-line with compactly supported coefficients. We determine asymptotics of a
counting function of resonances in complex discs at large radius, describe the
forbidden domain for resonances and obtain trace formulas in terms of
resonances. We apply these results to the Euler-Bernoulli operator on the
half-line. The coefficients of this operator are positive and constants outside
a finite interval. We show that this operator does not have any eigenvalues and
resonances iff its coefficients are constants on the whole half-line.",1704.00499v1
2017-10-02,Qubit-assisted transduction for a detection of surface acoustic waves near the quantum limit,"We demonstrate ultra-sensitive measurement of fluctuations in a
surface-acoustic-wave~(SAW) resonator using a hybrid quantum system consisting
of the SAW resonator, a microwave (MW) resonator and a superconducting qubit.
The nonlinearity of the driven qubit induces parametric coupling, which
up-converts the excitation in the SAW resonator to that in the MW resonator.
Thermal fluctuations of the SAW resonator near the quantum limit are observed
in the noise spectroscopy in the MW domain.",1710.00467v1
2019-09-11,Precise Feshbach resonance spectroscopy using tight anharmonic traps,"Feshbach resonances are among the essential control tools used in ultracold
atom experiments. However, for complex atomic species the theoretical
characterization of resonances becomes challenging. For closely spaced
resonances, the measurement of three-body losses does not provide sufficient
resolution to discriminate them. For this reason, resonance spectroscopy of
trapped isolated atoms is becoming the state of the art. Here we show that
trapping the atoms in a double well potential such as an optical lattice or a
pair of optical tweezers enables precise characterization of not only the
resonance position and width, but also its pole strength, giving valuable
information about the atomic structure relevant for subsequent many-body
studies.",1909.04932v1
2021-01-27,Detection of electron spin resonance down to 10 K using localized spoof surface plasmon,"In this study, novel use of the electromagnetic field profile of a localized
spoof surface plasmonic mode to detect electron spin resonance is being
reported. The mode is supported on a resonator with a complementary metallic
spiral structure, etched on the ground plane of a microstrip line having a
characteristic impedance of 50 $\Omega$. The change in characteristics of the
mode of interest with lowering of temperature has been observed and analyzed.
Electron spin resonance spectra of a standard paramagnetic sample,
2,2-diphenyl-1-picrylhydrazyl, are recorded using this resonator down to 10 K.
Potential application of the mode in the detection of microwave Rashba
field-driven electron spin resonance has been discussed.",2101.11528v1
2018-03-18,High frequency limits for invariant Ruelle densities,"We establish an equidistribution result for Ruelle resonant states on compact
locally symmetric spaces of rank one. More precisely, we prove that among the
first band Ruelle resonances there is a density one subsequence such that the
respective products of resonant and co-resonant states converge weakly to the
Liouville measure. We prove this result by establishing an explicit
quantum-classical correspondence between eigenspaces of the scalar Laplacian
and the resonant states of the first band of Ruelle resonances which also leads
to a new description of Patterson-Sullivan distributions.",1803.06717v2
2018-03-20,A fast method to identify mean motion resonances,"The identification of mean motion resonances in exoplanetary systems or in
the Solar System might be cumbersome when several planets and large number of
smaller bodies are to be considered. Based on the geometrical meaning of the
resonance variable, an efficient method is introduced and described here, by
which mean motion resonances can be easily find without any a priori knowledge
on them. The efficiency of this method is clearly demonstrated by using known
exoplanets engaged in mean motion resonances, and also some members of
different families of asteroids and Kuiper-belt objects being in mean motion
resonances with Jupiter and Neptune respectively.",1803.07458v1
2018-03-30,Resonance in the $Y_{c}N$ potential model,"We calculate two-body $J^{\pi}=0^{+}, 1^{+}$, and $J^{\pi}=2^{+}$ resonance
states of $Y_{c}$ ($= \Lambda_{c}$, $\Sigma_{c}$, or $\Sigma_{c}^{*}$) and $N$
using the complex scaling method. We employ the $Y_{c}N$-CTNN potentials, which
were proposed in our previous study, and obtain four resonances near
$\Sigma_{c}N$ and $\Sigma_{c}^{*}N$ thresholds. From the analysis by the
binding energies of partial channel systems, we conclude that these resonance
states are Feshbach resonances. We compare the results with the $Y_{c}N$
resonance states in the heavy quark limit, where the $\Sigma_{c}N$ and
$\Sigma_{c}^{*}N$ thresholds are degenerate, and find that they form two pairs
of the heavy-quark doublets in agreement with the heavy quark spin symmetry.",1803.11349v1
2019-01-24,Semiclassical study of shape resonances in the Stark effect,"Semiclassical behavior of Stark resonances is studied. The complex distortion
outside a cone is introduced to study resonances in any energy region for the
Stark Hamiltonians with non-globally analytic potentials. The non-trapping
resolvent estimate is proved by the escape function method. The Weyl law and
the resonance expansion of the propagator are proved in the shape resonance
model. To prove the resonance expansion theorem, the functional
pseudodifferential calculus in the Stark effect is established, which is also
useful in the study of the spectral shift function.",1901.08315v2
2019-04-25,Double Quantum Dot scenario for spin resonance in current noise,"We show that interference between parallel currents through two quantum dots,
in presence of spin orbit interactions and strong on-site Coulomb repulsion,
leads to resonances in current noise at the corresponding Larmor frequencies.
An additional resonance at the difference of Larmor frequencies is present even
without spin-orbit interaction. The resonance lines have strength comparable to
the background shot noise and therefore can account for the numerous
observations of spin resonance in STM noise with non-polarized leads. We solve
also several other models that show similar resonances.",1904.11221v2
2021-03-30,Ultrahigh Q SOI Ring Resonator With Strip Waveguide,"The design and experimental demonstration of a large-area,
ultra-high-Q-factor and single-mode operation silicon ring resonator based on a
strip silicon photonic waveguide are presented, which is suitable for photon
gyroscopic application. Based on these designs, simulation results show that
the resonance depth is 0.9979 while the resonator is in an undercoupled state
with the coupling length L=2um and coupling gap d=0.2um. For the fabricated
resonator, the ultrahigh Q factor of 1.54*106 is experimentally demonstrated,
with the free spectrum range (FSR) of 0.036nm and the resonance depth is
0.9810.",2103.16016v1
2021-04-06,Bound States in the Continuum in Compact Acoustic Resonators,"We reveal that finite-size solid acoustic resonators can support genuine
bound states in the continuum (BICs) completely localized inside the resonator.
The developed theory provides the multipole classification of such BICs in the
resonators of various shapes. It is shown how breaking of the resonator's
symmetry turns BICs into quasi-BICs manifesting themselves in the scattering
spectra as high-Q Fano resonances. We believe that the revealed novel states
will push the performance limits of acoustic devices and will serve as high-Q
building blocks for acoustic sensors, antennas, and topological acoustic
structures.",2104.05539v1
2021-05-08,Strain effects on optical properties of linearly polarized resonant modes in the presence of monolayer graphene,"Recently, huge attention has been drawn to improve optical sensing devices
based on photonic resonators in the presence of graphene. In this paper, based
on the transfer matrix approach and TE polarization for the incident
electromagnetic waves, we numerically evaluate the transmission and reflection
spectra for one-dimensional photonic resonators and surface plasmon resonances
with strained graphene, respectively. We proved that a relatively small strain
field in graphene can modulate linearly polarized resonant modes within the
photonic bandgap of the defective crystal. Moreover, we study the strain
effects on the surface plasmon resonances created by the evanescent wave
technique at the interference between a monolayer graphene and prism.",2105.03633v1
2021-11-05,Enhanced Purcell factor for nanoantennas supporting interfering resonances,"We study the effect of coupled resonances and quasi-bound states in the
continuum (quasi-BICs) on the Purcell factor in dielectric resonant
nanoantennas. We analyze numerically interfering resonances in a nanodisk with
and without a substrate when the modes are coupled to an emitter localized
inside the nanodisk, and we quantify the modal contributions to the Purcell
factor also reconstructing the radiation patterns of the resonant system. It is
revealed that the Purcell effect can be boosted substantially for a strong
coupling of resonances in the quasi-BIC regime.",2111.03339v3
2022-05-06,Resonance nucleon scattering amplitude in the photonuclear reaction,"The cross section of the photonuclear reaction in the nucleon-resonance
region is calculated to search the resonance-nucleon scattering amplitude in
the nucleus. It is assumed that the resonance $R$ is produced and decayed in
the elementary photon-nucleon $(\gamma N)$ reaction in the nucleus as $\gamma N
\to R \to \gamma N$. The resonance interacts with the nucleons while
propagating through the nucleus. Therefore, the calculated photonuclear
reaction cross section is compared with the data to extract the
resonance-nucleon scattering parameters in the nucleus.",2205.03025v3
2022-07-27,Degenerate bound states in the continuum in square and triangular open acoustic resonators,"We consider square and equilateral triangular open acoustic resonators with
the $C_{4v}$ and $C_{3v}$ symmetries, respectively. There is an unique property
of square and triangular resonators of accidental number four-fold degeneracy
of eigenstates that gives rise to two-fold degenerate Friedrich-Wintgen (FW)
BICs. Compared to usual FW BICs the degenerate FW BICs maintain high $Q$-factor
in wide range of the size of resonators. That removes the fabrication
difficulties of proper choice of resonator. The presence of degenerate BICs in
triangular resonators is extremely sensitive to switch output flows by small
perturbations with $100\%$ efficiency.",2207.14162v1
2022-11-10,Resonances for rational Anosov maps on the torus,"A complete description of resonances for rational toral Anosov
diffeomorphisms preserving certain Reinhardt domains is presented. As a
consequence it is shown that every homotopy class of two-dimensional Anosov
diffeomorphisms contains maps with the sequence of resonances decaying
stretched-exponentially. This is achieved by introducing a certain group of
rational toral diffeomorphisms and computing the resonances of the respective
composition operator considered on suitable anisotropic spaces of
hyperfunctions. The class of examples is sufficiently rich to also include
non-linear Anosov maps with trivial resonances, or resonances decaying
exponentially, as well as with or without area-preservation or reversing
symmetries.",2211.05925v1
2023-05-30,Photonic Flatband Resonances in Multiple Light Scattering,"We introduce the concept of photonic flatband resonances for the example of
an array of high index dielectric particles. We employ the multiple Mie
scattering theory and reveal that both short range and long range interactions
between the resonators are crucial for the emerging collective resonances and
their associated photonic flatbands. By examining both nearfield and far field
characteristics, we uncover how the flatbands emerge due to fine tuning of
resonators radiation fields, and predict that hybridization of a flatband
resonance with an electric hotspot can lead to giant values of the Purcell
factor for the electric dipolar emitters.",2305.19456v1
2023-07-03,Generation of narrow beams of ultrarelativistic positrons (electrons) in the resonant strong electromagnetic field-assisted Breit-Wheeler process,"The resonant external field-assisted Breit-Wheeler process (Oleinik
resonances) for strong electromagnetic fields with intensities less than the
critical Schwinger field has been theoretically studied. The resonant
kinematics has been studied in detail. The case of high-energy initial gamma
quanta and emerging ultrarelativistic electron-positron pairs is studied. The
resonant differential cross section is obtained. The generation of narrow beams
of ultrarelativistic positrons (for Channel A) and electrons (for Channel B) is
predicted with a probability significantly exceeding corresponding to the
non-resonant process.",2307.00913v1
2023-09-01,Optical LC-like resonances in high-index particles,"Electric LC resonances, occurring in metallic circuits, govern the motion of
free electrons or electric signals. In this paper, optical LC-like resonances
in high-index particles (HIPs) or dielectric LC resonances have been studied,
which involve bounded electrons and optical fields instead. The resonance
effect is dominated by optical analogues of inductance and capacitance, which
can be determined according to the electromagnetic energy bounded near the
particle. The viewpoint of dielectric optical circuit with equivalent
parameters facilitates the understanding of dielectric resonance effect. The
result also provides a method for studying the optical properties of the HIPs.",2309.00179v2
2023-11-01,Singularities and asymptotic distribution of resonances for Schrödinger operators in one dimension,"We obtain new results about the high-energy distribution of resonances for
the one-dimensional Schr\""odinger operator. Our primary result is an upper
bound on the density of resonances above any logarithmic curve in terms of the
singular support of the potential. We also prove results about the distribution
of resonances in sectors away from the real axis, and construct a class of
potentials producing multiple sequences of resonances along distinct
logarithmic curves, explicitly calculating the asymptotic location of these
resonances. The results are unified by the use of an integral representation of
the reflection coefficients.",2311.00804v1
2023-11-22,The Potsdam astroComb (POCO) Part I: Mode crossing effect in feedback resonators,"We investigate theoretically and experimentally the mode interaction in an
integrated Silicon Nitride (Si3N4) microring resonator with interferometric
coupling realized by a feedback loop as an adjustable optical path path length
connecting the ring to the bus waveguide at two coupling sections. From the
transmission spectra recorded at different optical path lengths, two
resonances, 1596.5~nm and 1570.5~nm, were selected for detailed investigation.
Both resonances show the possibility of adjusting the resonance width and
depth. However, the transmission spectra around the first resonance also show
the effect of mode interaction. This is also well captured in the theoretical
model, from which we can derive a coupling rate for the mode interaction of
$3.4~\textrm{rad}~\textrm{ns}^{-1}$.",2311.13505v1
2024-03-19,Compositeness of near-threshold $s$-wave resonances,"The near-threshold clustering phenomenon is well understood by the low-energy
universality, for shallow bound states below the threshold. Nevertheless, the
characteristics of resonances slightly above the threshold still lack thorough
elucidation. We introduce a novel probabilistic interpretation scheme for
complex compositeness of resonances, in which the resonances with unphysically
large decay widths are inherently excluded. Employing this scheme to analyze
resonances via the effective range expansion, we demonstrate that
near-threshold resonances have small composite fraction, in sharp contrast to
shallow bound states below the threshold.",2403.12635v1
2021-03-30,"Enormous Berry-Curvature-Driven Anomalous Hall Effect in Topological Insulator (Bi,Sb)2Te3 on Ferrimagnetic Europium Iron Garnet beyond 400 K","To realize the quantum anomalous Hall effect (QAHE) at elevated temperatures,
the approach of magnetic proximity effect (MPE) was adopted to break the
time-reversal symmetry in the topological insulator (Bi0.3Sb0.7)2Te3 (BST)
based heterostructures with a ferrimagnetic insulator europium iron garnet
(EuIG) of perpendicular magnetic anisotropy. Here we demonstrate phenomenally
large anomalous Hall resistance (RAHE) exceeding 8 {\Omega} (\r{ho}AHE of 3.2
{\mu}{\Omega}*cm) at 300 K and sustaining to 400 K in 35 BST/EuIG samples,
surpassing the past record of 0.28 {\Omega} (\r{ho}AHE of 0.14
{\mu}{\Omega}*cm) at 300 K. The remarkably large RAHE as attributed to an
atomically abrupt, Fe-rich interface between BST and EuIG. Importantly, the
gate dependence of the AHE loops shows no sign change with varying chemical
potential. This observation is supported by our first-principles calculations
via applying a gradient Zeeman field plus a contact potential on BST. Our
calculations further demonstrate that the AHE in this heterostructure is
attributed to the intrinsic Berry curvature. Furthermore, for gate-biased 4 nm
BST on EuIG, a pronounced topological Hall effect (THE) coexisting with AHE is
observed at the negative top-gate voltage up to 15 K. Interface tuning with
theoretical calculations has opened up new opportunities to realize
topologically distinct phenomena in tailored magnetic TI-based
heterostructures.",2103.16487v4
1999-02-03,Partial Averaging Near a Resonance in Planetary Dynamics,"Following the general numerical analysis of Melita and Woolfson (1996), I
showed in a recent paper that a restricted, planar, circular planetary system
consisting of Sun, Jupiter and Saturn would be captured in a near (2:1)
resonance when one would allow for frictional dissipation due to interplanetary
medium (Haghighipour, 1998). In order to analytically explain this resonance
phenomenon, the method of partial averaging near a resonance was utilized and
the dynamics of the first-order partially averaged system at resonance was
studied. Although in this manner, the finding that resonance lock occurs for
all initial relative positions of Jupiter and Saturn was confirmed, the
first-order partially averaged system at resonance did not provide a complete
picture of the evolutionary dynamics of the system and the similarity between
the dynamical behavior of the averaged system and the main planetary system
held only for short time intervals. To overcome these limitations, the method
of partial averaging near a resonance is extended to the second order of
perturbation in this paper and a complete picture of dynamical behavior of the
system at resonance is presented. I show in this study that the dynamics of the
second-order partially averaged system at resonance resembles the dynamical
evolution of the main system during the resonance lock in general, and I
present analytical explanations for the evolution of the orbital elements of
the main system while captured in resonance.",9902049v1
1999-04-02,Geometric Solutions for the Neutrino Oscillation Length Resonance,"We give a geometric interpretation of the neutrino 'oscillation length
resonance' recently discovered by Petcov. We use this picture to identify two
new solutions for oscillation length resonances in a 3-layer earth model.",9904023v1
2000-01-21,Q-Factor Measurement of Nonlinear Superconducting Resonators,"A novel method, which combined a multi-bandwidth measurement and an
extrapolation procedure, is proposed for extracting the loaded Q-factor (Q_{L})
with improved accuracy from non-Lorentzian resonances of nonlinear
superconducting resonators.",0001310v1
2004-02-10,Feshbach resonances with large background scattering length: interplay with open-channel resonances,"Feshbach resonances are commonly described by a single-resonance Feshbach
model, and open-channel resonances are not taken into account explicitly.
However, an open-channel resonance near threshold limits the range of validity
of this model. Such a situation exists when the background scattering length is
much larger than the range of the interatomic potential. The open-channel
resonance introduces strong threshold effects not included in the
single-resonance description. We derive an easy-to-use analytical model that
takes into account both the Feshbach resonance and the open-channel resonance.
We apply our model to $^{85}$Rb, which has a large background scattering
length, and show that the agreement with coupled-channels calculations is
excellent. The model can be readily applied to other atomic systems with a
large background scattering length, such as $^6$Li and $^{133}$Cs. Our approach
provides full insight into the underlying physics of the interplay between
open-channel (or potential) resonances and Feshbach resonances.",0402278v2
2004-11-12,Resonance spin filter,"A design of the resonance spin finter is suggested in form of a quantum well
with three quantum wires attached. Explicit formula is suggested for
transmission coefficients accross the well in terms of the resonance
eigenfunction of the Schredinger operator on the well with Rashba spin-orbital
interaction.",0411354v1
2003-09-11,BABAR Resonance and Four-quark Mesons,"The new narrow resonance which has been observed at the B factories is
assigned to the I_z=0 component of iso-triplet charmed four-quark mesons, and
as its consequence, existence of additional narrow resonances in different
channels is predicted.",0309119v1
2003-11-06,On the charmed scalar resonances,"It is discussed that a newly observed broad bump around 2.3 GeV in the D\pi
mass distribution can include two scalar resonances, and is predicted that a
broad scalar resonance can be observed around 2.45 GeV in the DK channels.",0311069v1
2005-11-09,Enhancing switching in bistable nanomechanical oscillators by geometrical resonance,"It is shown how the cooperative effect of the geometrical resonance and
stochastic resonance mechanisms explains recent results on bistable
nanomechanical silicon oscillators (R. L. Badzey and P. Mohanty, Nature, vol.
437, 995-998 (2005)).",0511077v1
2001-03-27,Resonance absolute quantum reflection at selected energies,"The possibility of the resonance reflection (100 % at maximum) is revealed.
The corresponding exactly solvable models with the controllable numbers of
resonances, their positions and widths are presented.",0103148v1
2007-03-01,Entangling a nanomechanical resonator with a microwave field,"We show how the coherent oscillations of a nanomechanical resonator can be
entangled with a microwave cavity in the form of a superconducting coplanar
resonator. Dissipation is included and realistic values for experimental
parameters are estimated.",0703003v1
2012-11-04,Global estimates of resonances for 1D Dirac operators,"We discuss resonances for 1D massless Dirac operators with compactly
supported potentials on the line. We estimate the sum of the negative power of
all resonances in terms of the norm of the potential and the diameter of its
support.",1211.0714v1
2013-07-30,Electrodynamics of a ring-shaped spiral resonator,"We present analytical, numerical and experimental investigations of
electromagnetic resonant modes of a compact monofilar Archimedean spiral
resonator shaped in a ring, with no central part. Planar spiral resonators are
interesting as components of metamaterials for their compact deep-subwavelength
size. Such resonators couple primarily to the magnetic field component of the
incident electromagnetic wave, offering properties suitable for magnetic
meta-atoms. Surprisingly, the relative frequencies of the resonant modes follow
the sequence of the odd numbers, despite the nearly identical boundary
conditions for electromagnetic fields at the extremities of the resonator. In
order to explain the observed spectrum of resonant modes, we show that the
current distribution inside the spiral satisfies a particular Carleman type
singular integral equation. By solving this equation, we obtain a set of
resonant frequencies. The analytically calculated resonance frequencies and the
current distributions are in good agreement with experimental data and the
results of numerical simulations. By using low-temperature laser scanning
microscopy of a superconducting spiral resonator, we compare the experimentally
visualized ac current distributions over the spiral with the calculated ones.
Theory and experiment agree well with each other. Our analytical model allows
for calculation of a detailed three-dimensional magnetic field structure of the
resonators.",1307.7959v1
2014-10-08,Tailoring dielectric resonator geometries for directional scattering and Huygens' metasurfaces,"In this paper we describe a methodology for tailoring the design of
metamaterial dielectric resonators, which represent a promising path toward
low-loss metamaterials at optical frequencies. We first describe a procedure to
decompose the far field scattered by subwavelength resonators in terms of
multipolar field components, providing explicit expressions for the multipolar
far fields. We apply this formulation to confirm that an isolated
high-permittivity cube resonator possesses frequency separated electric and
magnetic dipole resonances, as well as a magnetic quadrupole resonance in close
proximity to the electric dipole resonance. We then introduce multiple
dielectric gaps to the resonator geometry in a manner suggested by perturbation
theory, and demonstrate the ability to overlap the electric and magnetic dipole
resonances, thereby enabling directional scattering by satisfying the first
Kerker condition. We further demonstrate the ability to push the quadrupole
resonance away from the degenerate dipole resonances to achieve local behavior.
These properties are confirmed through the multipolar expansion and show that
the use of geometries suggested by perturbation theory is a viable route to
achieve purely dipole resonances for metamaterial applications such as
wave-front manipulation with Huygens' metasurfaces. Our results are fully
scalable across any frequency bands where high-permittivity dielectric
materials are available, including microwave, THz, and infrared frequencies.",1410.2315v2
2015-01-28,Resonant normal form and asymptotic normal form behavior in magnetic bottle Hamiltonians,"We consider normal forms in `magnetic bottle' type Hamiltonians of the form
$H=\frac{1}{2}(\rho^2_\rho+\omega^2_1\rho^2) +\frac{1}{2}p^2_z+hot$ (second
frequency $\omega_2$ equal to zero in the lowest order). Our main results are:
i) a novel method to construct the normal form in cases of resonance, and ii) a
study of the asymptotic behavior of both the non-resonant and the resonant
series. We find that, if we truncate the normal form series at order $r$, the
series remainder in both constructions decreases with increasing $r$ down to a
minimum, and then it increases with $r$. The computed minimum remainder turns
to be exponentially small in $\frac{1}{\Delta E}$, where $\Delta E$ is the
mirror oscillation energy, while the optimal order scales as an inverse power
of $\Delta E$. We estimate numerically the exponents associated with the
optimal order and the remainder's exponential asymptotic behavior. In the
resonant case, our novel method allows to compute a `quasi-integral' (i.e.
truncated formal integral) valid both for each particular resonance as well as
away from all resonances. We applied these results to a specific magnetic
bottle Hamiltonian. The non resonant normal form yields theorerical invariant
curves on a surface of section which fit well the empirical curves away from
resonances. On the other hand the resonant normal form fits very well both the
invariant curves inside the islands of a particular resonance as well as the
non-resonant invariant curves. Finally, we discuss how normal forms allow to
compute a critical threshold for the onset of global chaos in the magnetic
bottle.",1501.07018v1
2016-03-19,Crosstalk-insensitive method for simultaneously coupling multiple pairs of resonators,"In a circuit consisting of two or more resonators, the inter-cavity crosstalk
is inevitable, which could create some problems, such as degrading the
performance of quantum operations and the fidelity of various quantum states.
The focus of this work is to propose a crosstalk-insensitive method for
simultaneously coupling multiple pairs of resonators, which is important in
large-scale quantum information processing and communication in a network
consisting of resonators or cavities. In this work, we consider 2N resonators
of different frequencies, which are coupled to a three-level quantum system
(qutrit). By applying a strong pulse to the coupler qutrit, we show that an
effective Hamiltonian can be constructed for simultaneously coupling multiple
pairs of resonators.~The main advantage of this proposal is that the effect of
inter-resonator crosstalks is greatly suppressed by using resonators of
different frequencies. In addition, by employing the qutrit-resonator
dispersive interaction, the intermediate higher-energy level of the qutrit is
virtually excited and thus decoherence from this level is suppressed. This
effective Hamiltonian can be applied to implement quantum operations with
photonic qubits distributed in different resonators. As one application of this
Hamiltonian, we show how to simultaneously generate multiple EPR pairs of
photonic qubits distributed in 2N resonators. Numerical simulations show that
it is feasible to prepare two high-fidelity EPR photonic pairs using a setup of
four one-dimensional transmission line resonators coupled to a superconducting
flux qutrit with current circuit QED technology.",1603.06108v1
2016-10-05,The arrow of time in open quantum systems and dynamical breaking of the resonance-antiresonance symmetry,"Open quantum systems are often represented by non-Hermitian effective
Hamiltonians that have complex eigenvalues associated with resonances. In
previous work we showed that the evolution of tight-binding open systems can be
represented by an explicitly time-reversal symmetric expansion involving all
the discrete eigenstates of the effective Hamiltonian. These eigenstates
include complex-conjugate pairs of resonant and anti-resonant states. An
initially time-reversal-symmetric state contains equal contributions from the
resonant and anti-resonant states. Here we show that as the state evolves in
time, the symmetry between the resonant and anti-resonant states is
automatically broken, with resonant states becoming dominant for $t>0$ and
anti-resonant states becoming dominant for $t<0$. Further, we show that there
is a time-scale for this symmetry-breaking, which we associate with the ""Zeno
time."" We also compare the time-reversal symmetric expansion with an asymmetric
expansion used previously by several researchers. We show how the present
time-reversal symmetric expansion bypasses the non-Hilbert nature of the
resonant and anti-resonant states, which previously introduced exponential
divergences into the asymmetric expansion.",1610.01548v3
2010-05-19,Evidence for the psi(5S) and psi(4D) c-cbar vector resonances,"We present evidence for the psi(5S) and psi(4D) c-cbar vector resonances in
experimental data published by the Belle and BaBar Collaborations. Central
masses and resonance widths are estimated.",1005.3490v1
2017-01-06,Frequency-Temperature sensitivity reduction with optimized microwave Bragg resonators,"Dielectric resonators are employed to build state-of-the-art low-noise and
high- stability oscillators operating at room and cryogenic temperatures. A
resonator temperature coefficient of frequency is one criterion of performance.
This paper reports on predictions and measurements of this temperature
coefficient of frequency for three types of cylindrically-symmetric Bragg
resonators operated at microwave frequencies. At room temperature, microwave
Bragg resonators have the best potential to reach extremely high Q-factors.
Research has been conducted over the last decade on modeling, optimizing and
realizing such high Q-factor devices for applications such as filtering,
sensing, and frequency metrology. We present an optimized design, which has a
temperature sensitivity 2 to 4 times less than current whispering gallery mode
resonators without using temperature compensating techniques and about 30% less
than other existing Bragg resonators. Also, the performance of a new generation
single-layered Bragg resonators, based on a hybrid-Bragg-mode, is reported with
a sensitivity of about -12ppm/K at 295K. For a single reflector resonator, it
achieves a similar level of performance as a double-Bragg-reflector resonator
but with a more compact structure and performs six times better than
whispering-gallery-mode resonators. The hybrid resonator promises to deliver a
new generation of high-sensitivity sensors and high-stability room-temperature
oscillators.",1701.01600v1
2018-05-29,A highly accurate measurement of resonator $Q$-factor and resonance frequency,"The microwave cavity perturbation method is often used to determine material
parameters (electric permittivity and magnetic permeability) at high
frequencies and it relies on measurement of the resonator parameters. We
present a method to determine the $Q$-factor and resonance frequency of
microwave resonators which is conceptually simple but provides a sensitivity
for these parameters which overcomes those of existing methods by an order of
magnitude. The microwave resonator is placed in a feedback resonator setup,
where the output of an amplifier is connected to its own input with the
resonator as a band pass filter. After reaching steady-state oscillation, the
feedback circuit is disrupted by a fast microwave switch and the transient
signal, which emanates from the resonator, is detected using down-conversion.
The Fourier transform of the resulting time-dependent signal yields directly
the resonance profile of the resonator. Albeit the method is highly accurate,
this comes with a conceptual simplicity, ease of implementation and lower
circuit cost. We compare existing methods for this type of measurement to
explain the sensitivity of the present technique and we also make a prediction
for the ultimate sensitivity for the resonator $Q$ and $f_0$ determination.",1805.11347v3
2017-12-11,Two-photon driven Kerr resonator for quantum annealing with three-dimensional circuit QED,"We propose a realizable circuit QED architecture for engineering states of a
superconducting resonator off-resonantly coupled to an ancillary
superconducting qubit. The qubit-resonator dispersive interaction together with
a microwave drive applied to the qubit gives rise to a Kerr resonator with
two-photon driving that enables us to efficiently engineer the quantum state of
the resonator such as generation of the Schrodinger cat states for
resonator-based universal quantum computation. Moreover, the presented
architecture is easily scalable for solving optimization problem mapped into
the Ising spin glass model, and thus served as a platform for quantum
annealing. Although various scalable architecture with superconducting qubits
have been proposed for realizing quantum annealer, the existing annealers are
currently limited to the coherent time of the qubits. Here, based on the
protocol for realizing two-photon driven Kerr resonator in three-dimensional
circuit QED (3D cQED), we propose a flexible and scalable hardware for
implementing quantum annealer that combines the advantage of the long coherence
times attainable in 3D cQED and the recently proposed resonator based
Lechner-Hauke-Zoller (LHZ) scheme. In the proposed resonator based LHZ
annealer, each spin is encoded in the subspace formed by two coherent state of
3D microwave superconducting resonator with opposite phase, and thus the
fully-connected Ising model is mapped onto the network of the resonator with
local tunable three-resonator interaction. This hardware architecture provides
a promising physical platform for realizing quantum annealer with improved
coherence.",1712.03613v2
2020-01-17,Resonances in non-axisymmetric gravitational potentials,"We study sectoral resonances of the form $j\kappa= m(n-\Omega)$ around a
non-axisymmetric body with spin rate $\Omega$, where $\kappa$ and $n$ are the
epicyclic frequency and mean motion of a particle, respectively, where $j>0$
and $m$ ($<0$ or $>0$) are integers, $j$ being the resonance order. This
describes $n/\Omega \sim m/(m-j)$ resonances inside and outside the corotation
radius,as well as prograde and retrograde resonances. Results are: (1) the
kinematics of a periodic orbit depends only on $(m',j')$, the irreducible
(relatively prime) version of $(m,j)$. In a rotating frame, the periodic orbit
has $j'$ braids, $|m'|$ identical sectors and $|m'|(j'-1)$ self-crossing
points; (2) thus, Lindblad resonances (with $j=1$) are free of self-crossing
points; (3) resonances with same $j'$ and opposite $m'$ have the same
kinematics, and are called $twins$; (4) the order of a resonance at a given
$n/\Omega$ depends on the symmetry of the potential. A potential that is
invariant under a $2\pi/k$-rotation creates only resonances with $m$ multiple
of $k$; (5) resonances with same $j$ and opposite $m$ have the same kinematics
and same dynamics, and are called $true~twins$; (6) A retrograde resonance
($n/\Omega < 0$) is always of higher order than its prograde counterpart
($n/\Omega > 0$); (7) the resonance strengths can be calculated in a compact
form with the classical operators used in the case of a perturbing satellite.
Applications to Chariklo and Haumea are made.",2001.06382v1
2020-02-22,Is the K-matrix approach adequate for describing overlapping resonances?,"The K-matrix method is widely used unitary parametrization for several
resonances with the same quantum numbers. But in fact resonances in this
approach are separated and do not overlap.",2002.10949v1
2017-05-22,Horocyclic invariance of Ruelle resonant states for contact Anosov flows in dimension 3,"We show that for smooth contact Anosov flows in dimension 3, the resonant
states associated to the first band of Ruelle resonances are distributions that
are killed by the unstable derivative.",1705.07965v1
2017-09-25,HTS YBCO Resonator Configuration with Coplanar Optimized Flux Concentrator Strongly Coupled to rf SQUID,"We developed a novel magnetic coupling module formed of a monolayer
superconducting flux concentrator, which is integrated with a coplanar
resonator strongly coupled to HTS rf-SQUID. Three types of resonators,
including a long stripline resonator between input loop and pick-up loop of the
flux concentrator, a complementary split ring resonator (CSRR), and also a
spiral shape inside the input loop are explored. The resonance quality factors
as well as the coupling to the SQUID of different patterns of these three types
of the resonators is evaluated using Finite Element Method (FEM) simulations.
Several readout methods to couple the electronic system to the resonators are
tested, including inductive (coil) and capacitive (transmission line)
couplings, and the optimum readout is reported for each of the resonators.
Among the evaluated resonator types, a spiral shape resonator with optimal
design showing the highest quality factor (5900) together with the strongest
coupling to the SQUID (-0.5 dB) at resonance frequency of 836 MHz, is
fabricated using 200 nm thick superconducting YBCO on a 1 mm thick crystalline
LaAlO3 substrate. The flux concentrator of the module is optimized by the
variation of its linewidths and also its input loop radius to obtain maximum
flux transformation efficiency.",1709.09960v1
2020-10-28,Chains of Planets in Mean Motion Resonances Arising from Oligarchic Growth,"Exoplanet systems with multiple planets in mean motion resonances have often
been hailed as a signpost of disk driven migration. Resonant chains like
Kepler-223 and Kepler-80 consist of a trio of planets with the three-body
resonant angle librating and/or with a two-body resonant angle librating for
each pair. Here we investigate whether close-in super-Earths and mini-Neptunes
forming in situ can lock into resonant chains due to dissipation from a
depleted gas disk. We simulate the giant impact phase of planet formation,
including eccentricity damping from a gaseous disk, followed by subsequent
dynamical evolution over tens of millions of years. In a fraction of simulated
systems, we find that planets naturally lock into resonant chains. These
planets achieve a chain of near-integer period ratios during the gas disk
stage, experience eccentricity damping that captures them into resonance, stay
in resonance as the gas disk dissipates, and avoid subsequent giant impacts,
eccentricity excitation, and chaotic diffusion that would dislodge the planets
from resonance. Disk conditions that enable planets to complete their formation
during the gas disk stage enable those planets to achieve tight period ratios
<= 2 and, if they happen to be near integer period ratios, lock into resonance.
Using the weighting of different disk conditions deduced by MacDonald et al.
(2020) and forward modeling Kepler selection effects, we find that our
simulations of in situ formation via oligarchic growth lead to a rate of
observable trios with integer period ratios and librating resonant angles
comparable to observed Kepler systems.",2010.14743v1
2021-03-18,Resonant and non-resonant relaxation of globular clusters,"Globular clusters contain a finite number of stars. As a result, they
inevitably undergo secular evolution (`relaxation') causing their mean
distribution function (DF) to evolve on long timescales. On one hand, this
long-term evolution may be interpreted as driven by the accumulation of local
deflections along each star's mean field trajectory -- so-called `non-resonant
relaxation'. On the other hand, it can be thought of as driven by non-local,
collectively dressed and resonant couplings between stellar orbits, a process
termed `resonant relaxation'. In this paper we consider a model globular
cluster represented by a spherical, isotropic isochrone DF, and compare in
detail the predictions of both resonant and non-resonant relaxation theories
against tailored direct $N$-body simulations. In the space of orbital actions
(namely the radial action and total angular momentum), we find that both
resonant and non-resonant theories predict the correct morphology for the
secular evolution of the cluster's DF, although non-resonant theory
over-estimates the amplitude of the relaxation rate by a factor ${\sim 2}$. We
conclude that the secular relaxation of hot isotropic spherical clusters is not
dominated by collectively amplified large-scale potential fluctuations, despite
the existence of a strong ${\ell = 1}$ damped mode. Instead, collective
amplification affects relaxation only marginally even on the largest scales.
The predicted contributions to relaxation from smaller scale fluctuations are
essentially the same from resonant and non-resonant theories.",2103.10165v1
2021-09-21,Surviving Lower Dimensional Invariant Tori of a Resonant Torus with any Number of Resonances,"We provide sufficient conditions on integrable analytic Hamiltonians that
guarantee the existence, under arbitrary sufficiently small analytic
perturbations, of invariant lower dimensional tori associated to an invariant
resonant torus of the unperturbed Hamiltonian.",2109.10064v1
2021-10-07,TRAPPIST-1: Dynamical analysis of the transit-timing variations and origin of the resonant chain,"We analyze solutions drawn from the recently published posterior distribution
of the TRAPPIST-1 system, which consists of seven Earth-size planets appearing
to be in a resonant chain around a red dwarf. We show that all the planets are
simultaneously in two-planet and three-planet resonances, apart from the
innermost pair for which the two-planet resonant angles circulate. By means of
a frequency analysis, we highlight that the transit-timing variation (TTV)
signals possess a series of common periods varying from days to decades, which
are also present in the variations of the dynamical variables of the system.
Shorter periods (e.g., the TTVs characteristic timescale of 1.3 yr) are
associated with two-planet mean-motion resonances, while longer periods arise
from three-planet resonances. By use of $N$-body simulations with migration
forces, we explore the origin of the resonant chain of TRAPPIST-1 and find that
for particular disc conditions, a chain of resonances - similar to the observed
one - can be formed which accurately reproduces the observed TTVs. Our analysis
suggests that while the 4-yr collected data of observations hold key
information on the two-planet resonant dynamics, further monitoring of
TRAPPIST-1 will soon provide signatures of three-body resonances, in particular
the 3.3 and 5.1 yr periodicities expected for the current best-fit solution.
dditional observations would help to assess whether the innermost pair of
planets is indeed resonant (its proximity to the 8:5 resonance being
challenging to explain), and therefore give additional constraints on formation
scenarios.",2110.03340v2
2023-08-14,Dynamical characterization of the 6/1 mean motion resonance between Quaoar's ring and Weywot,"Recently, it has been reported the discovery of a dense ring around the
trans-Neptunian object 50000 Quaoar. The ring particles seem to be very close
to the 6/1 mean motion resonance with Weywot, the only known satellite in the
system. In this work we investigate the dynamical environment in the close
vicinity of the 6/1 orbital resonance in the context of the restricted three
body problem. We aim to analyze whether, in view of observational constraints,
the ring could be effectively evolving in resonant motion with the satellite.
Through the technique of dynamical maps we identify and characterize the 6/1
mean motion resonance, finding that the main location of the resonance deviates
by only $29$ km from the central part of the ring. This difference lies within
the 3$\sigma$ confidence level, considering the uncertainties in the
observational parameters. We also show that the Weywot's eccentricity plays a
significant role in the dynamical structure of the 6/1 resonance. The results
show that the resonance width is smaller than the estimated ring's width. Under
assumption of a ring with eccentricity smaller than 0.05, clumping of test
particles appears at the position of the different resonant multiplets,
considering the nominal value of Weywot's eccentricity. This is in agreement
with observations, which indicate that the estimated resonance width ($\leq$ 10
km) is comparable with the narrow and dense arc of material within Quaoar's
ring. Our results may be an indicative that the 6/1 resonance resonance plays a
key role in confining the arc ring.",2308.07189v1
2023-12-08,Boosting Resonant Sensing in Fluids: A Surprising Discovery,"Micro-mechanical resonators are widely used in modern sensing technology due
to their high quality-factor (Q), enabling sensitive detection of various
stimuli. However, the performance of these resonators in fluid environments is
limited by significant viscous and acoustic radiation losses that reduce their
Q. Here, we present a paradigm-shifting discovery that challenges the
conventional wisdom of resonant sensing in fluids. We report an optimal volume
of fluid over a 2D micro-resonator that increases the Q by up to 1000% compared
to that in air. We have conducted precise experiments on piezoelectric,
circular, membrane-type micro-resonators of 4 mm diameter fabricated using MEMS
technology on silicon-on-insulator (SOI) wafers. The top side of the resonator
was filled with different volumes of fluid and its Q was measured through
resonance tracking by actuating the resonator with an appropriate voltage. We
found the existence of an optimal volume of fluid that maximized the Q. We
argue that this phenomenon is a result of a balance between the enhancement of
kinetic energy of the resonator due to mass loading of the fluid and the energy
dissipation through viscous and acoustic radiation losses in the fluid medium.
This remarkable enhancement in Q substantially improves the sensitivity of the
resonator, with important implications for diverse applications such as
biosensing, chemical detection, and environmental monitoring. Our findings
challenge the prevailing understanding of resonant sensing in fluids and open
up new avenues for the development of highly sensitive and accurate sensors.",2312.05214v1
1995-12-26,The Hubbard Model: Introduction and Selected Rigorous Results,"The Hubbard model is a ""highly oversimplified model"" for electrons in a solid
which interact with each other through extremely short ranged repulsive
(Coulomb) interaction. The Hamiltonian of the Hubbard model consists of two
pieces; H_hop which describes quantum mechanical hopping of electrons, and Hint
which describes nonlinear repulsive interaction. Either H_hop or H_int alone is
easy to analyze, and does not favor any specific order. But their sum
H=H_hop+H_int is believed to exhibit various nontrivial phenomena including
metal-insulator transition, antiferromagnetism, ferrimagnetism, ferromagnetism,
Tomonaga-Luttinger liquid, and superconductivity. It is believed that we can
find various interesting ""universality classes"" of strongly interacting
electron systems by studying the idealized Hubbard model.
  In the present article we review some mathematically rigorous results on the
Hubbard model which shed light on ""physics"" of this fascinating model. We
mainly concentrate on magnetic properties of the model at its ground states. We
discuss Lieb-Mattis theorem on the absence of ferromagnetism in one dimension,
Koma-Tasaki bounds on decay of correlations at finite temperatures in
two-dimensions, Yamanaka-Oshikawa-Affleck theorem on low-lying excitations in
one-dimension, Lieb's important theorem for half-filled model on a bipartite
lattice, Kubo-Kishi bounds on the charge and superconducting susceptibilities
of half-filled models at finite temperatures, and three rigorous examples of
saturated ferromagnetism due to Nagaoka, Mielke, and Tasaki. We have tried to
make the article accessible to nonexperts by describing basic definitions and
elementary materials in detail.",9512169v4
1996-10-08,Low-Lying Excited States and Low-Temperature Properties of an Alternating Spin-1 / Spin-1/2 Chain : A DMRG study,"We report spin wave and DMRG studies of the ground and low-lying excited
states of uniform and dimerized alternating spin chains. The DMRG procedure is
also employed to obtain low-temperature thermodynamic properties of the system.
The ground state of a 2N spin system with spin-1 and spin-1/2 alternating from
site to site and interacting via an antiferromagnetic exchange is found to be
ferrimagnetic with total spin $s_G=N/2$ from both DMRG and spin wave analysis.
Both the studies also show that there is a gapless excitation to a state with
spin $s_G-1$ and a gapped excitation to a state with spin $s_G+1$.
Surprisingly, the correlation length in the ground state is found to be very
small from both the studies for this gapless system. For this very reason, we
show that the ground state can be described by a variational ``ansatz'' of the
product type. DMRG analysis shows that the chain is susceptible to a
conditional spin-Peierls' instability. The DMRG studies of magnetization,
magnetic susceptibility ($\chi$) and specific heat show strong magnetic-field
dependence. The product $\chi T$ shows a minimum as a function of
temperature($T$) at low-magnetic fields and the minimum vanishes at
high-magnetic fields. This low-field behaviour is in agreement with earlier
experimental observations. The specific heat shows a maximum as a function of
temperature and the height of the maximum increases sharply at high magnetic
fields. It is hoped that these studies will motivate experimental studies at
high-magnetic fields.",9610080v1
1997-04-07,A DMRG Study of Low-Energy Excitations and Low-Temperature Properties of Alternating Spin Systems,"We use the density matrix renormalization group (DMRG) method to study the
ground and low-lying excited states of three kinds of uniform and dimerized
alternating spin chains. The DMRG procedure is also employed to obtain
low-temperature thermodynamic properties of these systems. We consider a 2N
site system with spins $s_1$ and $s_2$ alternating from site to site and
interacting via a Heisenberg antiferromagnetic exchange. The three systems
studied correspond to $(s_1 ,s_2 )$ being equal to $(1,1/2),(3/2,1/2)$ and
$(3/2,1)$; all of them have very similar properties. The ground state is found
to be ferrimagnetic with total spin $s_G =N(s_1 - s_2)$. We find that there is
a gapless excitation to a state with spin $s_G -1$, and a gapped excitation to
a state with spin $s_G +1$. Surprisingly, the correlation length in the ground
state is found to be very small for this gapless system. The DMRG analysis
shows that the chain is susceptible to a conditional spin-Peierls instability.
Furthermore, our studies of the magnetization, magnetic susceptibility $\chi$
and specific heat show strong magnetic-field dependences. The product $\chi T$
shows a minimum as a function of temperature T at low magnetic fields; the
minimum vanishes at high magnetic fields. This low-field behavior is in
agreement with earlier experimental observations. The specific heat shows a
maximum as a function of temperature, and the height of the maximum increases
sharply at high magnetic fields. Although all the three systems show
qualitatively similar behavior, there are some notable quantitative differences
between the systems in which the site spin difference, $|s_1 - s_2|$, is large
and small respectively.",9704057v1
1997-11-13,The singlet-triplet magnetism and induced spin fluctuations in the high-$T_c$ copper oxides,"High-$T_c$ cuprates like $La_{2-x}Sr_{x}CuO_{4}$ and $YBa_{2-x}Cu_{3}O_{6+x}$
are considered as a system of the electron and hole polar pseudo-Jahn-Teller
$CuO_{4}$ centers $[{CuO}_{4}^{7-}]_{JT}$ and $[CuO_{4}^{5-}]_{JT}$,
respectively, or a system of the local bosons moving in a lattice of the hole
centers. Ground manifold of the polar centers includes three terms $^{1}A_{1g}$
(Zhang-Rice singlet), $^{1}E_{u}$, $^{3}E_{u}$ with different spin
multiplicity, orbital degeneracy and parity that provides an unconventional
multi-mode behaviour of the cuprates. The spin subsystem of the copper oxides
within the polar Jahn-Teller $CuO_{4}$ centers model is a two-component spin
liquid and corresponds to a singlet-triplet magnet with possible noncollinear
spin configurations. In the framework of a modified mean field approximation
some kinds of spin ordering are discussed including as a trivial singlet or
triplet states as a pure quantum singlet-triplet mixed state. A local boson
movement is accompanied by a modulation of the spin density on the site
resulting in the so called induced spin fluctuations. Some unconventional
features of the induced spin fluctuations are considered including an
appearance of the induced longitudinal ferrimagnetism with an appropriate
contribution to the spin susceptibility, a possibility to observe and examine
the charge fluctuations with the help of the traditional magnetic methods such
as the magnetic inelastic neutron scattering and the spin lattice relaxation
experiments. The suggested model, in comparison with the nearly
antiferromagnetic Fermi-liquid model, represents new approach to the
description of the spin system of the high-$T_c$ cuprates.",9711116v1
1998-06-21,Diagonal Ladders: A New Class of Models for Strongly Coupled Electron Systems,"We introduce a class of models defined on ladders with a diagonal structure
generated by $n_p$ plaquettes. The case $n_p=1$ corresponds to the necklace
ladder and has remarkable properties which are studied using DMRG and recurrent
variational ansatzes. The AF Heisenberg model on this ladder is equivalent to
the alternating spin-1/spin-1/2 AFH chain which is known to have a
ferrimagnetic ground state (GS). For doping 1/3 the GS is a fully doped (1,1)
stripe with the holes located mostly along the principal diagonal while the
minor diagonals are occupied by spin singlets. This state can be seen as a Mott
insulator of localized Cooper pairs on the plaquettes. A physical picture of
our results is provided by a $t_p-J_p$ model of plaquettes coupled diagonally
with a hopping parameter $t_d$. In the limit $t_d \to \infty$ we recover the
original $t-J$ model on the necklace ladder while for weak hopping parameter
the model is easily solvable. The GS in the strong hopping regime is
essentially an ""on link"" Gutzwiller projection of the weak hopping GS. We
generalize the $t_p-J_p-t_d$ model to diagonal ladders with $n_p >1$ and the 2D
square lattice. We use in our construction concepts familiar in Statistical
Mechanics as medial graphs and Bratelli diagrams.",9806251v1
1999-07-28,Ground state of an $S=1/2$ distorted diamond chain - model of $\rm Cu_3 Cl_6 (H_2 O)_2 \cdot 2H_8 C_4 SO_2$,"We study the ground state of the model Hamiltonian of the trimerized $S=1/2$
quantum Heisenberg chain $\rm Cu_3 Cl_6 (H_2 O)_2 \cdot 2H_8 C_4 SO_2$ in which
the non-magnetic ground state is observed recently. This model consists of
stacked trimers and has three kinds of coupling constants between spins; the
intra-trimer coupling constant $J_1$ and the inter-trimer coupling constants
$J_2$ and $J_3$. All of these constants are assumed to be antiferromagnetic. By
use of the analytical method and physical considerations, we show that there
are three phases on the $\tilde J_2 - \tilde J_3$ plane ($\tilde J_2 \equiv
J_2/J_1$, $\tilde J_3 \equiv J_3/J_1$), the dimer phase, the spin fluid phase
and the ferrimagnetic phase. The dimer phase is caused by the frustration
effect. In the dimer phase, there exists the excitation gap between the
two-fold degenerate ground state and the first excited state, which explains
the non-magnetic ground state observed in $\rm Cu_3 Cl_6 (H_2 O)_2 \cdot 2H_8
C_4 SO_2$. We also obtain the phase diagram on the $ \tilde J_2 - \tilde J_3$
plane from the numerical diagonalization data for finite systems by use of the
Lanczos algorithm.",9907440v3
1999-12-30,Ground State Properties of an S=1/2 Distorted Diamond Chain,"We investigate the ground state properties of an S=1/2 distorted diamond
chain described by the Hamiltonian ${\cal
H}=J_1\sum_\ell\bigl\{\bigl(\vecS_{3\ell-1}\cdot\vecS_{3\ell}
+\vecS_{3\ell}\cdot\vecS_{3\ell+1}\bigr)+J_2\vecS_{3\ell-2}\cdot\vecS_{3\ell-1}
+J_3\bigl(\vecS_{3\ell-2}\cdot\vecS_{3\ell}+\vecS_{3\ell}\cdot\vecS_{3\
ell+2}\bigr)-H S_{\ell}^z\bigr\}$ ($J_1,~J_2,~J_3\geq0$), which models well a
trimerized S=1/2 spin chain system
Cu$_3$Cl$_6$(H$_2$O)$_2$$\cdot$2H$_8$C$_4$SO$_2$. Using an exact
diagonalization method by means of the Lancz\""os technique, we determine the
ground state phase diagram in the H=0 case, composed of the dimerized, spin
fluid, and ferrimagnetic phases. Performing a degenerate perturbation
calculation, we analyze the phase boundary line between the latter two phases
in the $J_2,~J_3\llJ_1$ limit, the result of which is in good agreement with
the numerical result. We calculate, by the use of the density matrix
renormalization group method, the ground state magnetization curve for the case
(a) where $J_1=1.0$, $J_2=0.8$, and $J_3=0.5$, and the case (b) where
$J_1=1.0$, $J_2=0.8$, and $J_3=0.3$. We find that in the case (b) the
2/3-plateau appears in addition to the 1/3-plateau which also appears in the
case (a). The translational symmetry of the Hamiltonian $\cal H$ is
spontaneously broken in the 2/3-plateau state as well as in the dimerized
state.",9912482v1
2001-01-23,Finite-Size and surface effects in maghemite nanoparticles: Monte Carlo simulations,"Finite-size and surface effects in fine particle systems are investigated by
Monte Carlo simulation of a model of a $\gamma$-Fe$_2$O$_3$ (maghemite) single
particle. Periodic boundary conditions have been used to simulate the bulk
properties and the results compared with those for a spherical shaped particle
with free boundaries to evidence the role played by the surface on the
anomalous magnetic properties displayed by these systems at low temperatures.
Several outcomes of the model are in qualitative agreement with the
experimental findings. A reduction of the magnetic ordering temperature,
spontaneous magnetization, and coercive field is observed as the particle size
is decreased. Moreover, the hysteresis loops become elongated with high values
of the differential susceptibility, resembling those from frustrated or
disordered systems. These facts are consequence of the formation of a surface
layer with higher degree of magnetic disorder than the core, which, for small
sizes, dominates the magnetization processes of the particle. However, in
contradiction with the assumptions of some authors, our model does not predict
the freezing of the surface layer into a spin-glass-like state. The results
indicate that magnetic disorder at the surface simply facilitates the thermal
demagnetization of the particle at zero field, while the magnetization is
increased at moderate fields, since surface disorder diminishes ferrimagnetic
correlations within the particle. The change in shape of the hysteresis loops
with the particle size demonstrates that the reversal mode is strongly
influenced by the reduced atomic coordination and disorder at the surface.",0101348v1
2001-11-28,On the origin of neutron magnetic scattering in anti-site disordered Sr2FeMoO6 double perovskites,"Anti-site disordering in Sr2FeMoO6 double perovskites (containing Mo atoms at
Fe positions, and viceversa) has recently been shown to have a dramatic
influence in their magnetic and magnetotransport properties. In the present
study, two polycrystalline Sr2FeMoO6 samples showing different degrees of
anti-site disorder (a nominally 'ordered' sample with 70% of cationic ordering
and a nominally 'disordered' sample with 18% of cationic ordering) have been
examined by magnetic measurements and neutron powder diffraction (NPD)
techniques in the 15-500K temperature range. Our main finding is that the
'disordered' sample exhibits a strong magnetic scattering (noticeable even at
500K), comparable to that displayed by the 'ordered' one below TC= 415 K. For
the 'disordered' sample, the magnetic scattering exhibited on low angle Bragg
positions, is not to be ascribed to a (non-existent) ferrimagnetic ordering:
our results suggest that it originates upon naturally-occurring groups of Fe
cations in which strong antiferromagnetic (AFM) Fe-O-Fe superexchange
interactions are promoted, similar to those existing in the LaFeO3 perovskite.
These Fe groups are not magnetically isolated, but coupled by virtue of Fe-O-Mo
AFM interactions, which maintain the long-range coherence of this AFM
structure. Susceptibility measurements confirm the presence of AFM interactions
below 770 K.",0111524v1
2002-07-03,Magnetic enhancement of Co$_{0.2}$Zn$_{0.8}$Fe$_2$O$_4$ spinel oxide by mechanical milling,"We report the magnetic properties of mechanically milled
Co$_{0.2}$Zn$_{0.8}$Fe$_2$O$_4$ spinel oxide. After 24 hours milling of the
bulk sample, the XRD spectra show nanostructure with average particle size
$\approx$ 20 nm. The as milled sample shows an enhancement in magnetization and
ordering temperature compared to the bulk sample. If the as milled sample is
annealed at different temperatures for the same duration, recrystallization
process occurs and approaches to the bulk structure on increasing the annealing
temperatures. The magnetization of the annealed samples first increases and
then decreases. At higher annealing temperature ($\sim$ 1000$^{0}$C) the system
shows two coexisting magnetic phases {\it i.e.}, spin glass state and
ferrimagnetic state, similar to the as prepared bulk sample. The room
temperature M\""{o}ssbauer spectra of the as milled sample, annealed at
300$^{0}$C for different durations (upto 575 hours), suggest that the observed
change in magnetic behaviour is strongly related with cations redistribution
between tetrahedral (A) and octahedral (O) sites in the spinel structure. Apart
from the cation redistribution, we suggest that the enhancement of
magnetization and ordering temperature is related with the reduction of B site
spin canting and increase of strain induced anisotropic energy during
mechanical milling.",0207095v1
2002-11-12,High temperature susceptibility in electron doped Ca1-xYxMnO3: Double Exchange vs Superexchange,"We present a study of the magnetic properties of the electron doped
manganites Ca1-xYxMnO3 (for 0<=x<=0.25) in the paramagnetic regime. For the
less doped samples (x<=0.1) the magnetic susceptibility, c(T), follows a
Curie-Weiss (CW) law only for T > 450 K and, below this temperature, c^-1(T)
shows a ferrimagnetic-like curvature. We approached the discussion of these
results in terms of a simple mean-field model where double exchange,
approximated by a ferromagnetic Heisenberg-like interaction between Mn3+ and
Mn4+ ions, competes with classical superexchange. For higher levels of doping
(x>=0.15), the CW behaviour is observed down to the magnetic ordering
temperature (Tmo) and a better description of c(T) was obtained by assuming
full delocalization of the eg electrons. In order to explore the degree of
delocalization as a function of T and x, we analyzed the problem through
Montecarlo simulations. Within this picture we found that at high T the
electrons doped are completely delocalized but, when Tmo is approached, they
form magnetic polarons of large spin that cause the observed curvature in
c^-1(T) for x<=0.1.",0211242v1
2004-11-29,Strong correlation effects of the Re 5$d$ electrons on the metal-insulator transition in Ca$_2$FeReO$_6$,"We have investigated the electronic structure of polycrystalline
Ca$_2$FeReO$_6$ using photoemission spectroscopy and band-structure
calculations within the local-density approximation+$U$ (LDA+$U$) scheme. In
valence-band photoemission spectra, a double-peak structure which is
characteristic of the metallic double perovskite series has been observed near
the Fermi level ($E_{\rm F}$), although it is less distinct compared to the
Sr$_2$FeMoO$_6$ case. The leading near-$E_{\rm F}$ structure has a very weak
spectral weight at $E_{\rm F}$ above the metal-insulator transition (MIT)
temperature $T_{\rm MI}$ of $\sim$140 K, and it loses the $E_{\rm F}$ weight
below $T_{\rm MI}$, forming a small energy gap.
  To reproduce this small energy gap in the calculation, we require a very
large effective $U$ ($U_{\rm eff}$) for Re (4 eV) in addition to a relatively
large $U_{\rm eff}$ for Fe (4 eV). Although the most of the experimental
features can be interpreted with the help of the band theory, the overall
agreement between the theory and the experiment was not satisfactory. We
demonstrate that the effective transfer integral between Fe and Re is actually
smaller than that between Fe and Mo in Ca$_2$FeMoO$_6$, which can explain both
MIT and very high ferrimagnetic transition temperature.",0411714v1
2005-07-05,Valence instability of cerium under pressure in the Kondo-like perovskite La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$,"Effect of hydrostatic pressure and magnetic field on electrical resistance of
the Kondo-like perovskite manganese oxide,
La$_{0.1}$Ce$_{0.4}$Sr$_{0.5}$MnO$_3$ with a ferrimagnetic ground state, have
been investigated up to 2.1 GPa and 9 T. In this compound, the Mn-moments
undergo double exchange mediated ferromagnetic ordering at $T_{\rm C}$ $\sim$
280 K and there is a resistance maximum, $T_{\rm max}$ at about 130 K which is
correlated with an antiferromagnetic ordering of {\it cerium} with respect to
the Mn-sublattice moments. Under pressure, the $T_{\rm max}$ shifts to lower
temperature at a rate of d$T_{max}$/d$P$ = -162 K/GPa and disappears at a
critical pressure $P_{\rm c}$ $\sim$ 0.9 GPa. Further, the coefficient, $m$ of
$-logT$ term due to Kondo scattering decreases linearly with increase of
pressure showing an inflection point in the vicinity of $P_{\rm c}$. These
results suggest that {\it cerium} undergoes a transition from Ce$^{3+}$ state
to Ce$^{4+}$/Ce$^{3+}$ mixed valence state under pressure. In contrast to
pressure effect, the applied magnetic field shifts $T_{\rm max}$ to higher
temperature presumably due to enhanced ferromagnetic Mn moments.",0507094v1
2005-08-29,"Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field","By means of the density matrix renormalization group (DMRG) method, the
magnetic properties of the J-J-J$^{\prime}$ quantum Heisenberg chains with spin
$S=1/2$, 1, 3/2 and 2 in the ground states are investigated in the presence of
a magnetic field. Two different cases are considered: (a) when $J$ is
antiferromagnetic and $J^{\prime}$ is ferromagnetic (i.e. the AF-AF-F chain),
the system is a ferrimagnet. The plateaus of the magnetization are observed. It
is found that the width of the plateaus decreases with increasing the
ferromagnetic coupling, and disappears when $% J^{\prime}/J$ passes over a
critical value. The saturated field is observed to be independent of the
ferromagnetic coupling; (b) when $J$ is ferromagnetic and $J^{\prime}$ is
antiferromagnetic (i.e. the F-F-AF chain), the system becomes an
antiferromagnet. The plateaus of the magnetization are also seen. The width of
the plateaus decreases with decreasing the antiferromagnetic coupling, and
disappears when $J^{\prime}/J $ passes over a critical value. Though the ground
state properties are quite different, the magnetization plateaus in both cases
tend to disappear when the ferromagnetic coupling becomes more dominant.
Besides, no fundamental difference between the systems with spin half-integer
and integer has been found.",0508685v1
2006-05-19,Spin-flop transition in antiferromagnetic multilayers,"A comprehensive theoretical investigation on the field-driven reorientation
transitions in uniaxial multilayers with antiferromagnetic coupling is
presented. It is based on a complete survey of the one-dimensional solutions
for the basic phenomenological (micromagnetic) model that describes the
magnetic properties of finite stacks made from ferromagnetic layers coupled
antiferromagnetically through spacer layers. The general structure of the phase
diagrams is analysed. At a high ratio of uniaxial anisotropy to
antiferromagnetic interlayer exchange, only a succession of collinear magnetic
states is possible. With increasing field first-order (metamagnetic)
transitions occur from the antiferromagnetic ground-state to a set of
degenerate ferrimagnetic states and to the saturated ferromagnetic state. At
low anisotropies, a first-order transition from the antiferromagnetic
ground-state to an inhomogeneous spin-flop state occurs. Between these two
regions, transitional magnetic phases occupy the range of intermediate
anisotropies. Detailed and quantitative phase diagrams are given for the basic
model of antiferromagnetic multilayer systems with N = 2 to 16 layers. The
connection of the phase diagrams with the spin-reorientation transitions in
bulk antiferromagnets is discussed. The limits of low anisotropy and large
numbers of layers are analysed by two different representations of the magnetic
energy, namely, in terms of finite chains of staggered vectors and in a general
continuum form. It is shown that the phenomena widely described as ``surface
spin-flop'' are driven only by the cut exchange interactions and the
non-compensated magnetic moment at the surface layers of a stacked
antiferromagnetic system.",0605493v1
2006-06-02,The Coupled Cluster Method Applied to the {\it XXZ} Model on the Square Lattice,"A review of the coupled cluster method (CCM) applied to lattice quantum spin
systems is presented here. The CCM formalism is explained and an application to
the spin-half {\it XXZ} model on the square lattice is presented. Low orders of
approximation are carried out analytically and a high-order CCM formulation is
presented. Results for the SUB2 approximation are carried out numerically for
SUB2-$m$ and analytically for SUB2. It is found that SUB2-$m$ results converge
rapidly to the full SUB2 solution, including new results for the SUB2-$m$
limiting points compared to the SUB2 critical point. Results for the
ground-state energy and the sublattice magnetisation are presented. A study of
the excitation spectrum of this model at the SUB2 critical point is given.
Indeed, the shape of the excitation spectrum at the SUB2 critical point is
identical to that predicted by spin-wave theory for the isotropic model, albeit
with a multiplicative factor of 1.1672. This result compares very well to
results of cumulant series expansions and Monte Carlo simulation that again
predict a similar shape for the excitation spectrum, but with multiplicative
factors of 1.18 and 1.21$\pm$0.03, respectively. Results for the isotropic
Heisenberg model on the square lattice for the spin-one antiferromagnet and the
spin-one/spin-half ferrimagnet are also given.",0606060v1
2006-07-12,Title Cluster-Variational Treatment of Disordered Mixed Spin Ising Model,"A disordered alloy Ap B1-p where both A and B represent the magnetic atoms
with respective spin SA =1/2 and SB =1 and whose magnetic interaction can be
described through Ising Hamiltonian is treated using the cluster-variational
method. In this method it is assumed that the system is built out of building
block which is embedded in an effective field. Taking building block as 4-atom
cluster the approximate free energy of the alloy is then obtained by treating
the interactions between spins within the cluster of all possible
configurations in exact manner and the rest of the interaction by an effective
variational field . The magnetization M and transition temperature Tc are then
calculated for different concentration and exchange parameters (JAA, JBB and
JAB). The magnetization M exhibits different kinds of ferrimagnetic behaviour
depending on concentration and relative strength of intra- and inter-
sub-network exchange interactions. For antiferromagnetic JAB, the sub-network
magnetization saturates and aligned antiferromagnetically at low temperature.
The existence of compensation temperature Tcm, where total magnetization
reverses its direction, depends sensitively on relative values of JAA/ JAB and
JBB/ JAB and p. For B (A)-rich alloy with small JAB, the direction of net
magnetization remains same upto Tc and a maximum of M appears at intermediate T
< Tc when JBB>> JAA (JBB<< JAA).When magnitude of JAB > JAA, JBB, Tc exhibits a
maximum with p. The transition temperature is much less than the mean-field
value for all cases. The magnetic susceptibility for diverges and is
Curie-Wiess like at T >>Tc. The meta-magnetic behaviour at high magnetic field
has been found. Some of these results are in tune with experimental observation
in amorphous rare-earth-transition metal alloys.",0607299v1
2006-10-18,Magnetic Properties and Metastable States in Spin-Crossover Transition of Co-Fe Prussian Blue Analogues,"The combination of spin transitions and magnetic ordering provides an
interesting structure of phase transitions in Prussian blue analogues (PBAs).
To understand the structure of stable and metastable states of Co-Fe PBA, it is
necessary to clarify free energy as a function of magnetization and the
fraction of the high-temperature component. Including the magnetic interaction
between high-temperature states, we study the magnetic phase transition of
Co-Fe PBA in addition to spin transitions. Here, we take into account the
degeneracy changes due to charge transfer between Co and Fe atoms accompanying
the spin transition. In this study, the charge transfer between Co and Fe atoms
is explicitly taken into account and also the ferrimagnetic structure of Co-Fe
PBAs is expressed in the proper way. First, we found systematic changes in the
structures of stable and metastable states as functions of system parameters
using mean field theory. In particular, the existence of a metastable
magnetic-ordered high-temperature state is confirmed at temperatures lower than
that of the hysteresis region of spin transitions. Second, we found that the
magnetic interaction causes complex ordering processes of a spin transition and
a magnetic phase transition. The effect of a magnetic field on the phase
structure is also investigated and we found metamagnetic magnetization
processes. Finally, the dynamical properties of this metastable state are
studied by Monte Carlo method.",0610500v2
2006-12-06,Epitaxial Bi2FeCrO6 Multiferroic Thin Films,"We present here experimental results obtained on Bi2FeCrO6 (BFCO) epitaxial
films deposited by laser ablation directly on SrTiO3 substrates. It has been
theoretically predicted, by Baettig and Spaldin, using first-principles density
functional theory that BFCO is ferrimagnetic (with a magnetic moment of 2 Bohr
magneton per formula unit) and ferroelectric (with a polarization of ~80
microC/cm2 at 0K). The crystal structure has been investigated using X-ray
diffraction which shows that the films are epitaxial with a high crystallinity
and have a degree of orientation depending of the deposition conditions and
that is determined by the substrate crystal structure. Chemical analysis
carried out by X-ray Microanalysis and X-ray Photoelectron Spectroscopy (XPS)
indicates the correct cationic stoichiometry in the BFCO layer, namely
(Bi:Fe:Cr = 2:1:1). XPS depth profiling revealed that the oxidation state of Fe
and Cr ions in the film remains 3+ throughout the film thickness and that both
Fe and Cr ions are homogeneously distributed throughout the depth.
Cross-section high-resolution transmission electron microscopy images together
with selected area electron diffraction confirm the crystalline quality of the
epitaxial BFCO films with no identifiable foreign phase or inclusion. The
multiferroic character of BFCO is proven by ferroelectric and magnetic
measurements showing that the films exhibit ferroelectric and magnetic
hysteresis at room temperature. In addition, local piezoelectric measurements
carried out using piezoresponse force microscopy (PFM) show the presence of
ferroelectric domains and their switching at the sub-micron scale.",0612168v1
2007-11-04,Torque magnetometry study of metamagnetic transitions in single-crystal HoNi2B2C at T\approx 1.9 K,"Metamagnetic transitions in single-crystal rare-earth nickel borocarbide
HoNi$_2$B$_2$C have been studied at T\approx 1.9 K with a Quantum Design torque
magnetometer. This compound is highly anisotropic with a variety of
metamagnetic states at low temperature which includes antiferromagnetic,
ferrimagnetic, non-collinear and ferromagnetic-like (saturated paramagnet)
states. The critical fields of the transitions depend crucially on the angle
$\theta$ between applied field and the easy axis [110]. Measurements of torque
along the c-axis have been made while changing the angular direction of the
magnetic field (parallel to basal tetragonal $ab$-planes) and with changing
field at fixed angle over a wide angular range. Two new phase boundaries in the
region of the non-collinear phase have been observed, and the direction of the
magnetization in this phase has been precisely determined. At low field the
antiferromagnetic phase is observed to be multidomain. In the angular range
very close to the hard axis [100] ($-6^{\circ} \lesssim\phi \lesssim
6^{\circ}$, where $\phi$ is the angle between field and the hard axis) the
magnetic behavior is found to be ``frustrated'' with a mixture of phases with
different directions of the magnetization.",0711.0533v1
2007-12-28,"Half Semimetallic Antiferromagnetism in the Sr$_2$CrTO$_6$ System, T=Os, Ru","Double perovskite Sr$_2$CrOsO$_6$ is (or is very close to) a realization of a
spin-asymmetric semimetallic compensated ferrimagnet, according to first
principles calculations. This type of near-half metallic antiferromagnet is an
unusual occurrence, and more so in this compound because the zero gap is
accidental rather than being symmetry determined. The large spin-orbit coupling
(SOC) of osmium upsets the spin balance (no net spin moment without SOC): it
reduces the Os spin moment by 0.27 $\mu_B$ and induces an Os orbital moment of
0.17 $\mu_B$ in the opposite direction. The effects combine (with small oxygen
contributions) to give a net total moment of 0.54 $\mu_B$ per cell in \scoo,
reflecting a large impact of SOC in this compound. This value is in moderately
good agreement with the measured saturation moment of 0.75 $\mu_B$. The value
of the net moment on the Os ion obtained from neutron diffraction (0.73 $\mu_B$
at low temperature) differs from the calculated value (1.14 $\mu_B$). Rather
surprisingly, in isovalent Sr$_2$CrRuO$_6$ the smaller SOC-induced spin changes
and orbital moments (mostly on Ru) almost exactly cancel. This makes
Sr$_2$CrRuO$_6$ a ""half (semi)metallic antiferromagnet"" (practically vanishing
net total moment) even when SOC is included, with the metallic channel being a
small-band-overlap semimetal. Fixed spin moment (FSM) calculations are
presented for each compound, illustrating how they provide different
information than in the case of a nonmagnetic material. These FSM results
indicate that the Cr moment is an order of magnitude stiffer against
longitudinal fluctuations than is the Os moment.",0712.4308v1
2008-03-06,Dimers on the Triangular Kagome Lattice,"We derive exact results for close-packed dimers on the triangular kagome
lattice (TKL), formed by inserting triangles into the triangles of the kagome
lattice. Because the TKL is a non-bipartite lattice, dimer-dimer correlations
are short-ranged, so that the ground state at the Rokhsar-Kivelson (RK) point
of the corresponding quantum dimer model on the same lattice is a short-ranged
spin liquid. Using the Pfaffian method, we derive an exact form for the free
energy, and we find that the entropy is 1/3 ln2 per site, regardless of the
weights of the bonds. The occupation probability of every bond is 1/4 in the
case of equal weights on every bond. Similar to the case of lattices formed by
corner-sharing triangles (such as the kagome and squagome lattices), we find
that the dimer-dimer correlation function is identically zero beyond a certain
(short) distance. We find in addition that monomers are deconfined on the TKL,
indicating that there is a short-ranged spin liquid phase at the RK point. We
also find exact results for the ground state energy of the classical Heisenberg
model. The ground state can be ferromagnetic, ferrimagnetic, locally coplanar,
or locally canted, depending on the couplings. From the dimer model and the
classical spin model, we derive upper bounds on the ground state energy of the
quantum Heisenberg model on the TKL.",0803.0742v2
2008-11-28,Metastable states influence on the magnetic behavior of the triangular lattice: Application to the spin-chain compound Ca3Co2O6,"It is known that the spin-chain compound Ca3Co2O6 exhibits very interesting
plateaus in the magnetization as a function of the magnetic field at low
temperatures. The origin of them is still controversial. In this paper we study
the thermal behavior of this compound with a single-flip Monte Carlo simulation
on a triangular lattice and demonstrate the decisive influence of metastable
states in the splitting of the ferrimagnetic 1/3 plateau below 10 K. We
consider the [Co2O6]n chains as giant magnetic moments described by large Ising
spins on planar clusters with open boundary conditions. With this simple
frozen-moment model we obtain stepped magnetization curves which agree quite
well with the experimental results for different sweeping rates. We describe
particularly the out-of-equilibrium states that split the low-temperature 1/3
plateau into three steps. They relax thermally to the 1/3 plateau, which has
long-range order at the equilibrium. Such states are further analyzed with
snapshots unveiling a domain-wall structure that is responsible for the
observed behavior of the 1/3 plateau. A comparison is also given of the exact
results in small triangular clusters with our Monte Carlo results, providing
further support for our thermal description of this compound.",0811.4772v1
2008-12-04,Sign reversal in the exchange bias and the collapse of hysteresis width across the magnetic compensation temperature in a single crystal of Nd0.75Ho0.25Al2,"In the admixed Nd0.75Ho0.25Al2 system, magnetic moments of Nd and Ho
occupying the same crystallographic site are antiferromagnetically coupled and
the chosen stoichiometry displays a magnetic compensation behavior (Tcomp of
about 24 K) in all orientations. In the vicinity of Tcomp, the conduction
electron polarization (CEP) assumes the role of a soft ferromagnet exchange
coupled to a pseudo-antiferromagnet comprising Nd/Ho moments, resulting in an
asymmetry in the hysteretic (M-H) loop, i.e., the notion of an exchange bias
field (Hexch). Across Tcomp, the CEP contribution reverses sign, and in
consonance, the asymmetry in the M-H loop also undergoes a phase reversal.
Interestingly, the width of the M-H loop shows a divergence, followed by a
collapse on approaching Tcomp from either end. The observed behavior confirms a
long standing prediction based on a phenomenological model for ferrimagnetic
systems. The field induced changes across Tcomp leave an imprint of a
quasi-phase transition in the heat capacity data. Magneto-resistance (\Delta R
/ R vs T) has an oscillatory response, in which the changes across Tc and Tcomp
can be recognized.",0812.0931v1
2009-01-30,Ferromagnetism in Co7(TeO3)4Br6: A byproduct of complex antiferromagnetic order and single-ion anisotropy,"Pronounced anisotropy of magnetic properties and complex magnetic order of a
new oxi-halide compound Co7(TeO3)4Br6 has been investigated by powder and
single crystal neutron diffraction, magnetization and ac susceptibility
techniques. Anisotropy of susceptibility extends far into the paramagnetic
temperature range. A principal source of anisotropy are anisotropic properties
of the involved octahedrally coordinated single Co(2+) ions, as confirmed by
angular-overlap-model calculations presented in this work. Incommensurate
antiferromagnetic order sets in at TN=34 K. Propagation vector is strongly
temperature dependent reaching k1=(0.9458(6), 0, 0.6026(5)) at 30 K. A
transition to a ferrimagnetic structure with k2=0 takes place at TC=27 K.
Magnetically ordered phase is characterized by very unusual anisotropy as well:
while M-H scans along b-axis reveals spectacularly rectangular but otherwise
standard ferromagnetic hysteresis loops, M-H studies along other two principal
axes are perfectly reversible, revealing very sharp spin flop (or spin flip)
transitions, like in a standard antiferromagnet (or metamagnet). Altogether,
the observed magnetic phenomenology is interpreted as an evidence of competing
magnetic interactions permeating the system, first of all of the single ion
anisotropy energy and the exchange interactions. Different coordinations of the
Co(2+)-ions involved in the low-symmetry C2/c structure of Co7(TeO3)4Br6 render
the exchange-interaction network very complex by itself. Temperature dependent
changes in the magnetic structure, together with an abrupt emergence of a
ferromagnetic component, are ascribed to continual spin reorientations
described by a multi-component, but yet unknown, spin Hamiltonian.",0901.4878v1
2010-01-20,Theory of Room Temperature Ferromagnet V(TCNE)_x (1.5 < x < 2): Role of Hidden Flat Bands,"Theoretical studies on the possible origin of room temperature ferromagnetism
(ferromagnetic once crystallized) in the molecular transition metal complex,
V(TCNE)_x (1.5<x<2) have been carried out. For this family, there have been no
definite understanding of crystal structure so far because of sample quality,
though the effective valence of V is known to be close to +2. Proposing a new
crystal structure for the stoichiometric case of x=2, where the valence of each
TCNE molecule is -1 and resistivity shows insulating behavior, exchange
interaction among d-electrons on adjacent V atoms has been estimated based on
the cluster with 3 vanadium atoms and one TCNE molecule. It turns out that
Hund's coupling among d orbitals within the same V atoms and antiferromagnetic
coupling between d oribitals and LUMO of TCNE (bridging V atoms) due to
hybridization result in overall ferromagnetism (to be precise, ferrimagnetism).
This view based on localized electrons is supplemented by the band picture,
which indicates the existence of a flat band expected to lead to ferromagnetism
as well consistent with the localized view. The off-stoichiometric cases (x<2),
which still show ferromagnetism but semiconducting transport properties, have
been analyzed as due to Anderson localization.",1001.3512v2
2010-01-25,Magnetism of small V clusters embedded in a Cu fcc matrix: an ab initio study,"We present extensive first principles density functional theory (DFT)
calculations dedicated to analyze the magnetic and electronic properties of
small V$_{n}$ clusters (n=1,2,3,4,5,6) embedded in a Cu fcc matrix. We consider
different cluster structures such as: i) a single V impurity, ii) several
V$_{2}$ dimers having different interatomic distance and varying local atomic
environment, iii) V$_{3}$ and iv) V$_{4}$ clusters for which we assume compact
as well as 2- and 1-dimensional atomic configurations and finally, in the case
of the v) V$_{5}$ and vi) V$_{6}$ structures we consider a square pyramid and a
square bipyramid together with linear arrays, respectively. In all cases, the V
atoms are embedded as substitutional impurities in the Cu network. In general,
and as in the free standing case, we have found that the V clusters tend to
form compact atomic arrays within the cooper matrix. Our calculated non
spin-polarized density of states at the V sites shows a complex peaked
structure around the Fermi level that strongly changes as a function of both
the interatomic distance and local atomic environment, a result that
anticipates a non trivial magnetic behavior. In fact, our DFT calculations
reveal, in each one of our clusters systems, the existence of different
magnetic solutions (ferromagnetic, ferrimagnetic, and antiferromagnetic) with
very small energy differences among them, a result that could lead to the
existence of complex finite-temperature magnetic properties. Finally, we
compare our results with recent experimental measurements.",1001.4515v1
2010-06-04,"Magnetism and thermodynamics of spin-(1/2,1) decorated Heisenberg chain with spin-1 pendants","The magnetic and thermodynamic properties of a new ferrimagnetic decorated
spin-(1/2,1) Heisenberg chain with spin-1 pendant spins are investigated for
three cases: (A) J1,J2>0; (B) J1>0, J2<0; and (C) J1<0, J2>0, where J1 and J2
are the exchange couplings between spins in the chain and along the rung,
respectively. The low-lying and magnetic properties are explored jointly by the
real-space renormalization group, spin wave, and density-matrix renormalization
group methods, while the transfer-matrix renormalization group method is
invoked to study the thermodynamics. It is found that the magnon spectra
consist of a gapless and two gapped branches. Two branches in case (C) have
intersections. The coupling dependence of low-energy gaps are analyzed. In a
magnetic field, an m=3/2 (m is the magnetization per unit cell) plateau is
observed for case (A), while two plateaux at m=1/2 and 3/2 are observed for
cases (B) and (C). Between the two plateaux in cases (B) and (C), the
sublattice magnetizations for the spins coupled by ferromagnetic interactions
have novel decreasing regions with increasing the magnetic field. At finite
temperature, the zero-field susceptibility temperature product chi*T and
specific heat exhibit distinct exotic features with varying the couplings and
temperature for different cases. chi*T is found to converge as T approaches
zero, which is different from the divergent behavior in the spin-(1/2,1)
mixed-spin chain without pendants. The observed thermodynamic behaviors are
also discussed with the help of their low-lying excitations.",1006.0794v1
2010-09-28,Absence of Ferromagnetism in Mn-doped Tetragonal Zirconia,"In a recent letter, it has been predicted within first principle studies that
Mn-doped ZrO2 compounds could be good candidate for spintronics application
because expected to exhibit ferromagnetism far beyond room temperature. Our
purpose is to address this issue experimentally for Mn-doped tetragonal
zirconia. We have prepared polycrystalline samples of Y0.15(Zr0.85-yMny)O2
(y=0, 0.05, 0.10, 0.15 & 0.20) by using standard solid state method at
equilibrium. The obtained samples were carefully characterized by using x-ray
diffraction, scanning electron microscopy, elemental color mapping, X-ray
photoemission spectroscopy and magnetization measurements. From the detailed
structural analyses, we have observed that the 5% Mn doped compound
crystallized into two symmetries (dominating tetragonal & monoclinic), whereas
higher Mn doped compounds are found to be in the tetragonal symmetry only. The
spectral splitting of the Mn 3s core-level x-ray photoelectron spectra confirms
that Mn ions are in the Mn3+ oxidation state and indicate a local magnetic
moment of about 4.5 {\mu}B/Mn. Magnetic measurements showed that compounds up
to 10% of Mn doping are paramagnetic with antiferromagnetic interactions.
However, higher Mn doped compound exhibits local ferrimagnetic ordering. Thus,
no ferromagnetism has been observed for all Mn-doped tetragonal ZrO2 samples.",1009.5583v2
2011-05-03,Simulation of Quantum Magnetism in Mixed Spin Systems with Impurity Doped Ion Crystal,"We propose the realization of linear crystals of cold ions which contain
different atomic species for investigating quantum phase transitions and
frustration effects in spin system beyond the commonly discussed case of
$s=1/2$. Mutual spin-spin interactions between ions can be tailored via the
Zeeman effect by applying oscillating magnetic fields with strong gradients.
Further, collective vibrational modes in the mixed ion crystal can be used to
enhance and to vary the strength of spin-spin interactions and even to switch
those forces from a ferro- to an antiferromagnetic character. We consider the
behavior of the effective spin-spin couplings in an ion crystal of spin-1/2
ions doped with high magnetic moment ions with spin S=3. We analyze the ground
state phase diagram and find regions with different spin orders including
ferrimagnetic states. In the most simple non-trivial example we deal with a
linear $\{$Ca$^+$, Mn$^+$, Ca$^+\}$ crystal with spins of $\{1/2,3,1/2}$. To
show the feasibility with current state-of-the-art experiments, we discuss how
quantum phases might be detected using a collective Stern-Gerlach effect of the
ion crystal and high resolution spectroscopy. Here, the state-dependent
laser-induced fluorescence of the indicator spin-1/2 ion, of species
$^{40}$Ca$^+$, reveals also the spin state of the simulator spin-3 ions,
$^{50}$Mn$^+$ as this does not possess suitable levels for optical excitation
and detection.",1105.0598v1
2011-12-18,Ground state factorization of heterogeneous spin models in magnetic fields,"The exact factorized ground state of a heterogeneous (ferrimagnetic) spin
model which is composed of two spins ($\rho, \sigma$) has been presented in
detail. The Hamiltonian is not necessarily translational invariant and the
exchange couplings can be competing antiferromagnetic and ferromagnetic
arbitrarily between different sub-lattices to build many practical models such
as dimerized and tetramerized materials and ladder compounds. The condition to
get a factorized ground state is investigated for non-frustrated spin models in
the presence of a uniform and a staggered magnetic field. According to the
lattice model structure we have categorized the spin models in two different
classes and obtained their factorization conditions. The first class contains
models in which their lattice structures do not provide a single uniform
magnetic field to suppress the quantum correlations. Some of these models may
have a factorized ground state in the presence of a uniform and a staggered
magnetic field. However, in the second class there are several spin models in
which their ground state could be factorized whether a staggered field is
applied to the system or not. For the latter case, in the absence of a
staggered field the factorizing uniform field is unique. However, the degrees
of freedom for obtaining the factorization conditions are increased by adding a
staggered magnetic field.",1112.4127v1
2012-10-19,"Ferromagnetic structures in Mn2CoGa and Mn2CoAl doped by Co, Cu, V, and Ti","The structure and magnetic properties in doped Heusler alloys of Mn2CoGa and
Mn2CoAl have been investigated by experiments and calculations. The main group
elements of Ga and Al are substituted by the magnetic or non-magnetic
transition metals, Co, Cu, V, and Ti in the alloy systems. Three kinds of local
ferromagnetic structures, Co-Mn-Co, Mn-Co-Mn and Mn-Co-V, have been found. They
embed in the native ferrimagnetic matrix and increase the magnetization with
different increments. The Co-Mn-Co ferromagnetic structure shows the largest
increment of 6.18{\mu}B /atom. In addition, interesting results for
non-magnetic Cu increasing the magnetization and the V atom having a large
ferromagnetic moment of about 1.0{\mu}B have been obtained. The exchange
interaction energy can be increased by the newly added Co and depleted by
supporting a ferromagnetic coupling in other substitution cases, and showing
the variation of the TC. Our calculation of electronic structure verifies the
strong d-d hybridization when the three ferromagnetic structures are achieved.
It has also been found that the covalent effect from the Ga and Al determines
the generation of the local ferromagnetic structure and the tolerance for
dopant content.",1210.5357v1
2012-10-20,Tunable spin reorientation transition and magnetocaloric effect in Sm0.7-xLaxSr0.3MnO3 series,"We report electrical resistivity, magnetic and magnetocaloric properties in
Sm0.7-xLaxSr0.3MnO3 series for x= 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.65, and
0.7. All the compounds show second order paramagnetic to ferromagnetic
transition at T = Tc which is tunable anywhere between 83 K and 373 K with a
proper choice of the doping level (x). The insulating ferromagnet x= 0
transforms to ferromagnetic metal below Tc for x= 0.1 and the insulator-metal
transition temperature shifts up with increasing x. The magnetization (M)
exhibits an interesting behavior as a function of temperature and doping level.
The field-cooled M(T) of all but x= 0.7 compound show a cusp at a temperature
T* much below Tc. While the Tc increases monotonically with increasing x, T*
increases gradually, attains a maximum value (T*= 137 K) for x= 0.6 and
decreases rapidly thereafter. It is suggested that the decrease of M(T) below
T* is due to ferrimagnetic interaction between Sm(4f) and Mn(3d) sublattices
that promotes spin-reorientation transition of the Mn-sublattice. The observed
anomalous feature in M(T) does not have impact on the dc resistivity. Magnetic
entropy change (delta Sm) was estimated from magnetization isotherms. The sign
of delta Sm is found to change from negative above T* to positive below T*
indicating the coexistence of normal and inverse magnetocaloric effects. delta
Sm is nearly composition independent (-delta Sm is about 1.5 J/Kg K for delta H
= 1 Tesla) and refrigeration capacity lies between 50 and 80 J/kg K for x =
0.1-0.6. The tunability of Curie temperature with a nearly constant delta Sm
value along with high refrigeration capacity makes this series of compounds
interesting for magnetic refrigeration over a wide temperature range.",1210.5595v1
2012-10-22,"Structure, magnetism and magnetic compensation behavior of Co50-xMn25Ga25+x and Co50-xMn25+xGa25 Heusler alloys","The structure, magnetism, magnetic compensation behavior, exchange
interaction and electronic structures of Co50-xMn25Ga25+x and Co50-xMn25+xGa25
(x=0-25) alloys have been systematically investigated by both experiments and
first-principles calculations. We found that all the samples exhibited body
centered cubic structures with a high degree of atomic ordering. With
increasing Ga content, the composition dependence of lattice parameters shows a
kink point at the middle composition in Co50-xMn25Ga25+x alloys, which can be
attributed to the enhanced covalent effect between the Ga and the transition
metals. Furthermore, a complicated magnetic competition has been revealed in
Co50-xMn25Ga25+x alloys, which causes the Curie temperature dramatically
decrease and results in a magnetic moment compensation behavior. In
Co50-xMn25+xGa25 alloys, however, with increasing Mn content, an additional
ferrimagnetic configuration was established in the native ferromagnetic matrix,
which causes the molecular moment monotonously decreases and the exchange
interaction enhances gradually. The electronic structure calculations indicate
that the Co50-xMn25+xGa25 alloys are likely to be in a coexistence state of the
itinerant and localized magnetism. Our study will be helpful to understand the
nature of magnetic ordering as well as to tune magnetic compensation and
electronic properties of Heusler alloys.",1210.5810v1
2012-10-22,Electronic structure and magnetic and optical properties of double perovskite Bi2FeCrO6 from first-principles investigation,"Double perovskite Bi$_2$FeCrO$_6$, related with BiFeO$_3$, is very
interesting because strong ferroelectricity and high magnetic Curie temperature
beyond room temperature are observed in it. However, existing
density-functional-theory (DFT) studies, using pseudo-potentials, produce
metallic ground state under the local density approximation (LDA) and need
LDA+U method to yield needed nonmetallic ground state, resulting in low
magnetic Curie temperature (below 130 K). Here, we optimize its crystal
structure and then investigate its electronic structure and magnetic and
optical properties by combining the full-potential augmented plane wave method
with Monte Carlo simulation. Our optimized structure is a robust ferrimagnetic
semiconductor. This nonmetallic phase is formed due to crystal field splitting
and spin exchange splitting, in contrast to Mott-Hubbard states in previous DFT
studies. Spin exchange constants and optical properties are calculated. Our ab
initio magnetic Curie temperature is 450 K, much higher than previous DFT-based
value and consistent with experimental results. Our study and analysis reveals
that the main magnetic mechanism is an antiferromagnetic superexchange between
Fe and Cr over the intermediate O atom. These results are useful to
understanding such perovskite materials and exploring their potential
applications.",1210.5981v2
2012-10-24,Theory of Half-Metallic Double Perovskites I: Double Exchange Mechanism,"The double perovskite material \SFMO has the rare and desirable combination
of a half-metallic ground state with 100% spin polarization and ferrimagnetic
\Tc$\simeq 420$K, well above room temperature. In this two-part paper, we
present a comprehensive theoretical study of the magnetic and electronic
properties of half metallic double perovskites. In this paper we present exact
diagonalization calculations of the ""fast"" Mo electronic degrees coupled to
""slow"" Fe core spin fluctuations treated by classical Monte Carlo techniques.
From the temperature dependence of the spin-resolved density of states, we show
that the electronic polarization at the chemical potential is proportional to
magnetization as a function of temperature. We also consider the effects of
disorder and show that excess Fe leaves the ground state half-metallic while
anti-site disorder greatly reduces the polarization. In a companion paper
titled ""Theory of Half-Metallic Double Perovskites II: Effective Spin
Hamiltonian and Disorder Effects"", we derive an effective classical spin
Hamiltonian that provides a new framework for understanding the magnetic
properties of half-metallic double perovskites including the effects of
disorder. Our results on the dependence of the spin polarization on temperature
and disorder has important implications for spintronics.",1210.6687v2
2012-10-29,Continuous magnetic phase transition in half-frustrated Ca2Os2O7,"We present the specific heat, magnetization, optical spectroscopy
measurements and the firstprinciple calculations on the Weberite structure
Ca2Os2O7 single crystal/polycrystalline sample. The Ca2Os2O7 shows a
Curie-Weiss nature at high temperature and goes into a ferrimagnetic insulating
state at 327 K on cooling. A \lambda-like peak is observed at 327 K in the
specific heat implying a second-order phase transition. The vanishing
electronic specific heat at low temperature suggests a full energy gap. At high
temperature above the transition, small amount of itinerant carriers with short
life time \tau are observed, which is gapped at 20 K with a direct gap of 0:24
eV . Our first principle calculations indicate that the anti-ferromagnetic
(AFM) correlation with intermediate Coulomb repulsion U could effectively split
Os(4b) t2g bands and push them away from Fermi level(EF). On the other hand, a
non-collinear magnetic interaction is needed to push the Os(4c) bands away from
EF, which could be induced by Os(4c)-Os(4c) frustration. Therefore, AFM
correlation, Coulomb repulsion U and non-collinear interaction all play
important roles for the insulating ground state in Ca2Os2O7.",1210.7571v1
2013-02-25,Monte Carlo investigation of a spherical ferrimagnetic core-shell nanoparticle under a time dependent magnetic field,"Monte Carlo simulation based on Metropolis algorithm has been used with a
great success to analyze the dynamic phase transition properties of a single
spherical core-shell nanoparticle system with a spin-3/2 core surrounded by a
spin-1 shell layer with antiferromagnetic interface coupling under the
influence of a time dependent oscillating magnetic filed. It has been found
that the dynamic phase boundaries strongly depend on the Hamiltonian parameters
such as for the high amplitude and period values of the external field, the
phase transition temperature sharply changes whereas it tends to slowly alter
as the reduced magnitude of interlayer parameter $\mathrm{J_{int}/J_{sh}}$
increases. Moreover, it is observed that the magnetization curves of the
particle have been found to obey P-type, N-type and Q-type classification
schemes under certain conditions. Much effort has also been paid to the
influence of the particle size on the thermal and magnetic properties of the
particle. Finally, a comparison of our observations with those of recently
published study including dynamic treatments of a nanocubic core-shell system
is represented and the findings indicate that there exists a qualitatively good
agreement with some relatively distinct differences.",1302.6227v2
2013-04-18,"Magnetostructural transition, metamagnetism, and magnetic phase coexistence in Co10Ge3O16","Co10Ge3O16 crystallizes in an intergrowth structure featuring alternating
layers of spinel and rock salt. Variable-temperature powder synchrotron X-ray
and neutron diffraction, magnetometry, and heat capacity experiments reveal a
magnetostructural transition at T_N = 203 K. This rhombohedral-to-monoclinic
transition involves a slight elongation of the CoO6 octahedra along the apical
axis. Below T_N, the application of a large magnetic field causes a
reorientation of the Co^2+ Ising spins. This metamagnetic transition is
first-order as evidenced by a latent heat observed in temperature-dependent
measurements. This transition is initially seen at T = 180 K as a broad upturn
in the M-H near H_C = 3.9 T. The upturn sharpens into a kink at T = 120 K and a
""butterfly"" shape emerges, with the transition causing hysteresis at high
fields while linear and reversible behavior persists at low fields. H_C
decreases as temperature is lowered and the loops at positive and negative
fields merge beneath T = 20 K. The antiferromagnetism is described by k_M = (00
1/2) and below T = 20 K a small uncompensated component with k_M = (000)
spontaneously emerges. Despite the Curie-Weiss analysis and ionic radius
indicating the Co2+ is in its high-spin state, the low-temperature M-H trends
toward saturation at M_S = 1.0 uB/Co. We conclude that the field-induced state
is a ferrimagnet, rather than a S = 1/2 ferromagnet. The unusual H-T phase
diagram is discussed with reference to other metamagnets and Co(II) systems.",1304.5000v3
2013-07-18,"Comment on ""Pt magnetic polarization on Y3Fe5O12 and magnetotransport characteristics""","In a recent Letter [Y.M. Lu et al., Phys. Rev. Lett. 110, 147207 (2013)], Lu
et al. reported on ""ferromagneticlike transport properties"" of thin films of
Pt, deposited ex situ via sputtering on the ferrimagnetic insulator Y3Fe5O12.
The authors found a magnetoresistance in Pt displaying a hysteresis
corresponding to the coercive field of Y3Fe5O12, consistent with the findings
of other groups. While the latter interpreted their data in terms of the
recently proposed spin-Hall magnetoresistance, Lu et al. attributed their
observation to a magnetic proximity effect. To support this interpretation,
they measured the X-ray magnetic circular dichroism (XMCD) at the Pt L2,3 edges
from a Pt/Y3Fe5O12 sample with a Pt thickness of 1.5 nm and derived an average
induced magnetic moment of 0.054 Bohr magnetons per Pt atom. This is
contradictory to the results of our previous comprehensive XMCD study of three
different Pt/Y3Fe5O12 samples with Pt thicknesses of 3, 7, and 10 nm from which
we identified an upper limit of (0.003 +/- 0.001) Bohr magnetons per Pt
[Gepr\""ags et al., Appl. Phys. Lett. 101, 262407 (2012), arXiv:1211.0916].",1307.4869v1
2013-10-23,Magnetic properties and electronic structure of Mn-Ni-Ga magnetic shape memory alloys,"Influence of disorder, antisite defects, martensite transition and
compositional variation on the magnetic properties and electronic structure of
Mn$_2$NiGa and Mn$_{1+x}$Ni$_{2-x}$Ga magnetic shape memory alloys have been
studied by using full potential spin-polarized scalar relativistic
Korringa-Kohn-Rostocker (FP-SPRKKR) method. Mn$_2$NiGa is ferrimagnetic and its
total spin moment increases when disorder in the occupancy of Mn$_{\rm Ni}$ (Mn
atom in Ni position) is considered. The moment further increases when Mn-Ga
antisite defect[1] is included in the calculation. A reasonable estimate of
$T_C$ for Mn$_2$NiGa is obtained from the exchange parameters for the
disordered structure. Disorder influences the electronic structure of
Mn$_2$NiGa through overall broadening of the density of states and a decrease
in the exchange splitting. Inclusion of antisite defects marginally broaden the
minority spin partial DOS (PDOS), while the majority spin PDOS is hardly
affected. For Mn$_{1+x}$Ni$_{2-x}$Ga where 1$\geq$$x$$\geq$0, as $x$ decreases,
Mn$_{\rm Mn}$ moment increases while Mn$_{\rm Ni}$ moment decreases in both
austenite and martensite phases. For $x$$\geq$ 0.25, the total moment of the
martensite phase is smaller compared to the austenite phase, which indicates
possible occurrence of inverse magnetocaloric effect. We find that the
redistribution of Ni 3$d$- Mn$_{\rm Ni}$ 3$d$ minority spin electron states
close to the Fermi level is primarily responsible for the stability of the
martensite phase in Mn-Ni-Ga.",1310.6130v2
2013-11-06,Phase diagram and exotic spin-spin correlations of anisotropic Ising model on the Sierpiński gasket,"The anisotropic antiferromagnetic Ising model on the fractal Sierpi\'{n}ski
gasket is intensively studied, and a number of exotic properties are disclosed.
The ground state phase diagram in the plane of magnetic field-interaction of
the system is obtained. The thermodynamic properties of the three plateau
phases are probed by exploring the temperature-dependence of magnetization,
specific heat, susceptibility and spin-spin correlations. No phase transitions
are observed in this model. In the absence of a magnetic field, the unusual
temperature dependence of the spin correlation length is obtained with $0
\leq$J$_b/$J$_a<1$, and an interesting crossover behavior between different
phases at J$_b/$J$_a=1$ is unveiled, whose dynamics can be described by the
J$_b/$J$_a$-dependence of the specific heat, susceptibility and spin
correlation functions. The exotic spin-spin correlation patterns that share the
same special rotational symmetry as that of the Sierpi\'{n}ski gasket are
obtained in both the $1/3$ plateau disordered phase and the $5/9$ plateau
partially ordered ferrimagnetic phase. Moreover, a quantum scheme is formulated
to study the thermodynamics of the fractal Sierpi\'{n}ski gasket with
Heisenberg interactions. We find that the unusual temperature dependence of the
correlation length remains intact in a small quantum fluctuation.",1311.1502v2
2013-11-18,Assembly-mediated Interplay of Dipolar Interactions and Surface Spin Disorder in Colloidal Maghemite Nanoclusters,"Controlled assembly of single-crystal, colloidal maghemite nanoparticles is
facilitated via a high-temperature polyol-based pathway. Structural
characterization shows that size-tunable nanoclusters of 50 and 86 nm diameters
(D), with high dispersibility in aqueous media, are composed of $\sim$ 13 nm
(d) crystallographically oriented nanoparticles. The interaction effects are
examined against the increasing volume fraction, $\phi$, of the inorganic
magnetic phase that goes from individual colloidal nanoparticles ($\phi$= 0.47)
to clusters ($\phi$= 0.72). The frozen-liquid dispersions of the latter exhibit
weak ferrimagnetic behavior at 300 K. Comparative Mossbauer spectroscopic
studies imply that intra-cluster interactions come into play. A new insight
emerges from the clusters temperature-dependent ac susceptibility that displays
two maxima in $\chi$''(T), with strong frequency dispersion. Scaling-law
analysis, together with the observed memory effects suggest that a superspin
glass state settles-in at T$_{B}$ $\sim$ 160-200 K, while at
lower-temperatures, surface spin-glass freezing is established at T$_{f}$
$\sim$40- 70 K. In such nanoparticle-assembled systems, with increased $\phi$,
Monte Carlo simulations corroborate the role of the inter-particle dipolar
interactions and that of the constituent nanoparticles surface spin disorder in
the emerging spin-glass dynamics.",1311.4302v2
2014-04-29,Magnetic nano-fluctuations in a frustrated magnet,"Frustrated systems exhibit remarkable properties due to the high degeneracy
of their ground states. Stabilised by competing interactions, a rich diversity
of typically nanometre-sized phase structures appear in polymer and colloidal
systems, while the surface of ice pre-melts due to geometrically frustrated
interactions. Atomic spin systems where magnetic interactions are frustrated by
lattice geometry provide a fruitful source of emergent phenomena, such as
fractionalised excitations analogous to magnetic monopoles. The degeneracy
inherent in frustrated systems may prevail all the way down to absolute zero
temperature, or it may be lifted by small perturbations or entropic effects. In
the geometrically frustrated Ising--like magnet Ca3Co2O6, we follow the
temporal and spatial evolution of nanoscale magnetic fluctuations firmly
embedded inside the spin--density--wave magnetic structure. These fluctuations
are a signature of a competing ferrimagnetic phase with an incommensurability
that is different from, but determined by the host. As the temperature is
lowered, the fluctuations slow down into a super-paramagnetic regime of stable
spatiotemporal nano-structures.",1404.7398v1
2014-09-01,Magnetic structures in the rich magnetic phase diagram of Ho$_2$RhIn$_8$,"The magnetic phase diagram of the tetragonal Ho$_2$RhIn$_8$ compound has
similar features to many related systems, revealing a zero magnetic field AF1
and a field-induced AF2 phases. Details of the magnetic order in the AF2 phase
were not reported yet for any of the related compounds. In addition, only the
Ho$_2$RhIn$_8$ phase diagram contains a small region of the incommensurate
zero-field AF3 phase. We have performed a number of neutron diffraction
experiments on single crystals of Ho$_2$RhIn$_8$ using several diffractometers
including experiments in both horizontal and vertical magnetic fields up to 4
T. We present details of the magnetic structures in all magnetic phases of the
rich phase diagram of Ho$_2$RhIn$_8$. The Ho magnetic moments point along the
tetragonal $c$ axis in every phase. The ground-state AF1 phase is characterized
by propagation vector $\textbf{k}$ = (1/2, 0, 0). The more complex
ferrimagnetic AF2 phase is described by four propagation vectors
$\textbf{k}_{0}$ = (0, 0, 0), $\textbf{k}_{1}$ = (1/2, 0, 0), $\textbf{k}_{2}$
= (0, 1/2, 1/2), $\textbf{k}_{3}$ = (1/2, 1/2, 1/2). The magnetic structure in
the AF3 phase is incommensurate with $\textbf{k}_{AF3}$ = (0.5, $\delta$, 0).
Our results are consistent with theoretical calculations based on crystal field
theory.",1409.0433v2
2014-12-11,Spontaneous formation of kagome network and Dirac half-semimetal on a triangular lattice,"In spin-charge coupled systems, geometrical frustration of underlying lattice
structures can give rise to nontrivial magnetic orders and electronic states.
Here we explore such a possibility in the Kondo lattice model with classical
localized spins on a triangular lattice by using a variational calculation and
simulated annealing. We find that the system exhibits a four-sublattice
collinear ferrimagnetic phase at 5/8 filling for a large Hund's-rule coupling.
In this state, the system spontaneously differentiates into the up-spin kagome
network and the isolated down-spin sites, which we call the kagome network
formation. In the kagome network state, the system becomes Dirac
half-semimetallic: The electronic structure shows a massless Dirac node at the
Fermi level, and the Dirac electrons are almost fully spin polarized due to the
large Hund's-rule coupling. We also study the effect of off-site Coulomb
repulsion in the kagome network phase where the system is effectively regarded
as a 1/3-filling spinless fermion system on the kagome lattice. We find that,
at the level of the mean-field approximation, a $\sqrt{3} \times \sqrt{3}$-type
charge order occurs in the kagome network state, implying the possibility of
fractional charge excitations in this triangular lattice system. Moreover, we
demonstrate that the kagome network formation with fully-polarized Dirac
electrons are controllable by an external magnetic field.",1412.3643v2
2015-01-27,"Magnon spectra and strong spin-lattice coupling in magnetically frustrated MnB2O4 (B = Mn,V): Inelastic light scattering studies","The ferrimagnetic spinels MnB2O4 (B = Mn,V) exhibit a similar series of
closely spaced magnetic and structural phase transitions at low temperatures,
reflecting both magnetic frustration and a strong coupling between the spin and
lattice degrees of freedom. Careful studies of excitations in MnB2O4 (B =
Mn,V), and the evolution of these excitations with temperature, are important
for obtaining a microscopic description of the role that magnetic excitations
and spin-lattice coupling play in the low temperature phase transitions of
these materials. We report an inelastic light (Raman) scattering study of the
temperature and magnetic field dependences of one- and two-magnon excitations
in MnV2O4 and Mn3O4. We observe a pair of q=0 one-magnon modes at 74 cm^{-1}
and 81 cm^{-1} in MnV2O4, which is in contrast with the single 80 cm^{-1} q=0
magnon that has been reported for MnV2O4 based on previous neutron scattering
measurements and spin wave calculations. Additionally, we find that the
two-magnon energy of MnV2O4 decreases (""softens"") with decreasing temperature
below T_{N}, which we attribute to strong coupling between magnetic and
vibrational excitations near the zone boundary.",1501.06897v1
2015-02-18,"Magnetocrystalline anisotropic effect in GdCo$_{1-x}$Fe$_x$AsO ($x = 0, 0.05$)","From a systematic study of the electrical resistivity $\rho(T,H)$, magnetic
susceptibility $\chi(T,H)$, isothermal magnetization $M(H)$ and the specific
heat $C(T,H)$, a temperature-magnetic field ($T$-$H$) phase diagram has been
established for GdCo$_{1-x}$Fe$_x$AsO ($x = 0$ and $0.05$) polycrystalline
compounds. GdCoAsO undergoes two long-range magnetic transitions: ferromagnetic
(FM) transition of Co $3d$ electrons ($T_\textup{C}^\textup{Co}$) and
antiferromagnetic (AFM) transition of Gd $4f$ electrons
($T_\textup{N}^\textup{Gd}$). For the Fe-doped sample ($x=0.05$), an extra
magnetic reorientation transition takes place below $T_\textup{N}^\textup{Gd}$,
which is likely associated with Co moments. The two magnetic species of Gd and
Co are coupled antiferromagnetically to give rise to ferrimagnetic (FIM)
behavior in the magnetic susceptibility. Upon decreasing the temperature ($T <
T_\textup{C}^\textup{Co}$), the magnetocrystalline anisotropy breaks up the FM
order of Co by aligning the moments with the local easy axes of the various
grains, leading to a spin reorientation transition at
$T_\textup{R}^\textup{Co}$. By applying a magnetic field,
$T_\textup{R}^\textup{Co}$ monotonically decreases to lower temperatures, while
the $T_\textup{N}^\textup{Gd}$ is relatively robust against the external field.
On the other hand, the applied magnetic field pulls the magnetization of grains
from the local easy direction to the field direction via a first-order
reorientation transition, with the transition field ($H_\textup{M}$) increasing
upon cooling the temperature.",1502.05139v1
2015-03-09,High pressure floating zone growth and structural properties of ferrimagnetic quantum paraelectric BaFe$_{12}$O$_{19}$,"High quality single crystals of BaFe$_{12}$O$_{19}$ were grown using the
floating zone technique in flowing oxygen pressurized to 100 atm. Single
crystal neutron diffraction was used to determine the nuclear and magnetic
structure of BaFe$_{12}$O$_{19}$ at 4 K and 295 K. At both temperatures, there
exist local electric dipoles formed by the off-mirror-plane displacements of
magnetic Fe$^{3+}$ ions at the bipyramidal sites. The displacement at 4 K is
about half of that at room temperature. The temperature dependence of the
specific heat shows no anomaly associated with long range polar ordering in the
temperature range from 1.90-300 K. The inverse dielectric permittivity,
$1/\varepsilon$, along the c-axis shows a $T^2$ temperature dependence between
10 K and 20 K, with a significantly reduced temperature dependence displayed
below 10 K. Moreover, as the sample is cooled below 1.4 K there is an anomalous
sharp upturn in $1/\varepsilon$. These features resemble those of classic
quantum paraelectrics such as SrTiO$_3$. The presence of the upturn in
$1/\varepsilon$ indicates that BaFe$_{12}$O$_{19}$ is a critical quantum
paraelectric system with Fe$^{3+}$ ions involved in both magnetic and electric
dipole formation.",1503.02568v1
2015-07-27,Ultrafast laser-induced changes of the magnetic anisotropy in a low-symmetry iron garnet film,"We explore a thermal mechanism of changing the anisotropy by femtosecond
laser pulses in dielectric ferrimagnetic garnets by taking a low symmetry
(YBiPrLu)3(FeGa)5O12 film grown on the (210)-oriented Gd3Ga5O12 substrate as a
model media. We demonstrate by means of spectral magneto-optical pump-probe
technique and phenomenological analysis, that the magnetization precession in
such a film is triggered by laser-induced changes of the growth-induced
magnetic anisotropy along with the well-known ultrafast inverse Faraday effect.
The change of magnetic anisotropy is mediated by the lattice heating induced by
laser pulses of arbitrary polarization on a picosecond time scale. We show that
the orientation of the external magnetic field with respect to the
magnetization easy plane noticeably affects the precession excited via the
anisotropy change. Importantly, the relative contributions from the ultrafast
inverse Faraday effect and the change of different growth-induced anisotropy
parameters can be controlled by varying the applied magnetic field strength and
direction. As a result, the amplitude and the initial phase of the excited
magnetization precession can be gradually tuned.",1507.07437v2
2015-10-05,Absence of magnetic proximity effects in magnetoresistive Pt/CoFe2O4 hybrid interfaces,"Ultra-thin Pt films grown on insulating ferrimagnetic CoFe2O4 (111) epitaxial
films display a magnetoresistance upon rotating the magnetization of the
magnetic layer. We report here X-ray magnetic circular dichroism (XMCD)
recorded at Pt-L2,3 and Pt-M3 edges. The results indicate that the Pt magnetic
moment, if any, is below the detection limit (< 0.001 {\mu}$_B$/Pt), thus
strongly favoring the view that the presence of CoFe2O4 does not induce the
formation of magnetic moments in Pt. Therefore, the observed magnetoresistance
cannot be attributed to some sort of proximity-induced magnetic moments at Pt
ions and subsequent magnetic-field dependent scattering. It thus follows that
either bulk (spin Hall and Inverse spin Hall Effects) or interface (Rashba)
spin-orbit related effects dominate the observed magnetoresistance.
Furthermore, comparison of bulk magnetization and XMCD data at (Fe,Co)-L2,3
edges suggests the presence of some spin disorder in the CoFe2O4 layer which
may be relevant for the observed anomalous non-saturating field-dependence of
spin Hall magnetoresistance.",1510.01080v4
2015-10-06,Spin Hall magnetoresistance as a probe for surface magnetization in Pt/CoFe$_2$O$_4$ bilayers,"We study the spin Hall magnetoresistance (SMR) in Pt grown $\textit{in situ}$
on CoFe$_2$O$_4$ (CFO) ferrimagnetic insulating (FMI) films. A careful analysis
of the angle-dependent and field-dependent longitudinal magnetoresistance
indicates that the SMR contains a contribution that does not follow the bulk
magnetization of CFO but it is a fingerprint of the complex magnetism at the
surface of the CFO layer, thus signaling SMR as a tool for mapping surface
magnetization. A systematic study of the SMR for different temperatures and CFO
thicknesses gives us information impossible to obtain with any standard
magnetometry technique. On one hand, surface magnetization behaves
independently of the CFO thickness and does not saturate up to high fields,
evidencing that the surface has its own anisotropy. On the other hand,
characteristic zero-field magnetization steps are not present at the surface
while they are relevant in the bulk, strongly suggesting that antiphase
boundaries are the responsible of such intriguing features. In addition, a
contribution from ordinary magnetoresistance of Pt is identified, which is only
distinguishable due to the low resistivity of the $\textit{in-situ}$ grown Pt.",1510.01449v2
2015-10-07,Metallic nanolines ruled by grain boundaries in graphene: an ab initio study,"We have performed an ab initio investigation of the energetic stability, and
the electronic properties of transition metals (TMs = Mn, Fe, Co, and Ru)
adsorbed on graphene upon the presence of grain boundaries (GBs). Our results
reveal an energetic preference for the TMs lying along the GB sites (TM/GB).
Such an energetic preference has been strengthened by increasing the
concentration of the TM adatoms; giving rise to TM nanolines on graphene ruled
by GBs. Further diffusion barrier calculations for Fe adatoms support the
formation of those TM nanolines. We find that the energy barriers parallel to
the GBs are sligthly lower in comparision with those obtained for the defect
free graphene; whereas, perpendicularly to the GBs the Fe adatoms face higher
energy barriers. Fe and Co (Mn) nanolines are ferromagnetic (ferrimagnetic), in
contrast the magnetic state of Ru nanolines is sensitive to the Ru/GB
adsorption geometry. The electronic properties of those TM nanolines were
characterized through extensive electronic band structure calculations. The
formation of metallic nanolines is mediated by a strong hybridization between
the TM and the graphene ($\pi$) orbitals along the GB sites. Due to the net
magnetization of the TM nanolines, our band structure results indicate an
anisotropic (spin-polarized) electronic current for some TM/GB systems.",1510.02066v1
2016-02-26,Multiferroic clusters: a new perspective for relaxor-type room-temperature multiferroics,"Multiferroics are promising for sensor and memory applications, but despite
all efforts invested in their research no single-phase material displaying both
ferroelectricity and large magnetization at room-temperature has hitherto been
reported. This situation has substantially been improved in the novel relaxor
ferroelectric single-phase , where polar nanoregions (PNR) transform into
static-PNR (SPNR) as evidenced by piezoresponse force microscopy (PFM) and
simultaneously enable congruent multiferroic clusters (MFC) to emerge from
inherent ferrimagnetic Bi(Fe,Co)O3 regions as verified by magnetic force
microscopy (MFM) and secondary ion mass spectrometry (SIMS). On these MFC,
exceptionally large direct and converse magnetoelectric coupling coefficients,
at room-temperature, were measured by PFM and MFM respectively. We expect the
non-ergodic relaxor properties which are governed by the Bi0.5K0.5TiO3
component to play a vital role in the strong ME coupling, by providing an
electrically and mechanically flexible environment to MFC. This new class of
non-ergodic relaxor multiferroics bears great potential for applications.
Especially the prospect of a ME nanodot storage device seems appealing.",1602.08348v1
2016-03-02,Effects of magnetic field and twin domains on magnetostructural phase mixture in Mn3O4: Raman scattering studies of untwinned crystals,"The ferrimagnetic spinel Mn3O4 exhibits large and anisotropic changes in
electronic and structural properties in response to an applied magnetic field.
These changes are thought to result from the field-dependent tuning---via
strong spin-lattice coupling---between two nearly degenerate magnetostructural
phases. Recent variable-magnetic-field studies of Mn3O4 have been performed on
melt-grown crystals, which can exhibit twin domains due to a Jahn-Teller
structural transition below the melting temperature. Because of the near
degeneracy of the magnetostructural phases, however, strain associated with the
twin domains likely affects the magnetic responses of Mn3O4. In this report, we
present a variable-magnetic-field Raman scattering study of untwinned Mn3O4
crystals grown out of a flux below the Jahn-Teller structural transition. We
measure distinct q = 0 magnetic and vibrational excitation spectra for each
isolated magnetostructural phase of untwinned Mn3O4 crystals and determine the
symmetries of the observed excitations. We determine how the magnetostructural
phase mixture changes in response to magnetic fields applied in the magnetic
easy plane. Lastly, by comparing results on flux- and melt-grown Mn3O4
crystals, we show that the intrinsic mixture of the two magnetostructural
phases is indeed strongly influenced by the presence of twin domains.",1603.00843v1
2016-04-26,First principles studies of the Gilbert damping and exchange interactions for half-metallic Heuslers alloys,"Heusler alloys have been intensively studied due to the wide variety of
properties that they exhibit. One of these properties is of particular interest
for technological applications, i.e. the fact that some Heusler alloys are
half-metallic. In the following, a systematic study of the magnetic properties
of three different Heusler families $\textrm{Co}_2\textrm{Mn}\textrm{Z}$,
$\text{Co}_2\text{Fe}\text{Z}$ and $\textrm{Mn}_2\textrm{V}\textrm{Z}$ with
$\text{Z}=\left(\text{Al, Si, Ga, Ge}\right)$ is performed. A key aspect is the
determination of the Gilbert damping from first principles calculations, with
special focus on the role played by different approximations, the effect that
substitutional disorder and temperature effects. Heisenberg exchange
interactions and critical temperature for the alloys are also calculated as
well as magnon dispersion relations for representative systems, the
ferromagnetic $\textrm{Co}_2\textrm{Fe}\textrm{Si}$ and the ferrimagnetic
$\textrm{Mn}_2\textrm{V}\textrm{Al}$. Correlations effects beyond standard
density-functional theory are treated using both the local spin density
approximation including the Hubbard $U$ and the local spin density
approximation plus dynamical mean field theory approximation, which allows to
determine if dynamical self-energy corrections can remedy some of the
inconsistencies which were previously reported for these alloys.",1604.07552v1
2016-04-29,Spin Seebeck effect through antiferromagnetic NiO,"We report temperature-dependent spin-Seebeck measurements on Pt/YIG bilayers
and Pt/NiO/YIG trilayers, where YIG (Yttrium iron garnet, Y$_3$Fe$_5$O$_{12}$)
is an insulating ferrimagnet and NiO is an antiferromagnet at low temperatures.
The thickness of the NiO layer is varied from 0 to 10 nm. In the Pt/YIG
bilayers, the temperature gradient applied to the YIG stimulates dynamic spin
injection into the Pt, which generates an inverse spin Hall voltage in the Pt.
The presence of a NiO layer dampens the spin injection exponentially with a
decay length of $2 \pm 0.6$ nm at 180 K. The decay length increases with
temperature and shows a maximum of $5.5 \pm 0.8$ nm at 360 K. The temperature
dependence of the amplitude of the spin-Seebeck signal without NiO shows a
broad maximum of $6.5 \pm 0.5$ $\mu$V/K at 20 K. In the presence of NiO, the
maximum shifts sharply to higher temperatures, likely correlated to the
increase in decay length. This implies that NiO is most transparent to magnon
propagation near the paramagnet-antiferromagnet transition. We do not see the
enhancement in spin current driven into Pt reported in other papers when 1-2 nm
NiO layers are sandwiched between Pt and YIG.",1604.08659v2
2016-06-21,"Theoretical and Experimental Investigation on Structural, Electronic and Magnetic Properties of layered Mn5O8","We have investigated the crystal, electronic, and magnetic structure of Mn5O8
by means of state of-the-art density functional theory calculations and neutron
powder diffraction (NPD) measurements. This compound stabilizes in the
monoclinic structure with space group C2/m where the Mn ions are in the
distorted octahedral and trigonal prismatic coordination with oxygen atoms. The
calculated structural parameters based on total energy calculations are found
to be in excellent agreement with low temperature NPD measurements when we
accounted correct magnetic structure and Coulomb correlation effect into the
computation. Bond strength analysis based on crystal orbital Hamiltonian
population between constituents indicating strong anisotropy in the bonding
behavior which results in layered nature of its crystal structure. Using fully
relativistic generalized-gradient approximation with Hubbard U (GGA+U) we found
that the magnetic ordering in Mn5O8 is A-type antiferromagnetic and the
direction of easy axis is [1 0 0] in agreement with susceptibility and NPD
measurements. However, the calculation without the inclusion of HubbardU leads
to ferrimagnetic half metal as ground state contradictory to experimental
findings, indicating the presence of strong Coulomb correlation effect in this
material. The GGA calculations without Coulomb correction effect itself is
sufficient to reproduce our experimentally observed magnetic moments in various
Mn sites.",1606.06603v1
2016-07-15,Picosecond all-optical switching of magnetic tunnel junctions,"Control of magnetism without using magnetic fields enables large-scale
integration of spintronic devices for memory, computation and communication in
the beyond-CMOS era. Mechanisms including spin torque transfer, spin Hall
effect, and electric field or strain assisted switching have been implemented
to switch magnetization in various spintronic devices. Their operation speed,
however, is fundamentally limited by the spin precession time to be longer than
10-100 picoseconds. Overcoming such a speed constraint is critical for the
prospective development of spintronics. Here we report the demonstration of
picosecond all-optical switching of a magnetic tunnel junction (MTJ)- the
building block of spintronic logic and memory -only using single telecom-band,
infrared laser pulses. This first optically switchable MTJ uses ferrimagnetic
GdFeCo as the free layer, and its switching is directly readout by measuring
its tunneling magnetoresistance with a DR/R ratio of 0.6%. An instrument
limited switching repetition rate at MHz has been demonstrated, but the
fundamental limit should be higher than tens of GHz. This result represents an
important step toward integrated opto-spintronic devices that combines
spintronics and photonics technologies to enable ultrafast conversion between
fundamental information carriers of electron spins and photons.",1607.04615v1
2016-10-08,Enhancement of Impedance by Chromium Substitution and Correlation with DC Resistivity in Cobalt Ferrite,"Chromium substituted cobalt ferrite with grain size less than the single
domain (approx. 70 nm) has been prepared by the sol-gel method. XRD analysis
reveals that the samples crystallize to cubic symmetry with spacegroup number
227. Two transition temperatures (TD (approx. 450 K) and TM (approx. 600 K)
have been observed from the impedance verses temperature measurement. TD
increases with the increase in frequency due to dipole response to the
frequency. TM is comparable with the para-ferrimagnetic transition temperature
of cobalt ferrite, which is independent of frequency. This result is well
supported by the temperature dependent DC conductivity measurement. The
modified Debye relaxation could be explained the impedance spectra of
CoFe2-xCrxO4. The grain and grain boundary effect on impedance spectroscopy has
been observed from Cole-Cole analysis. The ac conductivity follows Arrhenius
behavior at different frequencies. All the samples exhibit the negative
temperature coefficient of resistance behavior which reveals the semiconducting
behavior of the material. The Mott VRH model could explain the DC electrical
conductivity. Both ac impedance and DC resistivity are well co-related each
other to explain the electron transport properties in Cr substituted cobalt
ferrite. The electrical transport properties could be explained by the electron
hopping between different metal ions via oxygen in the material.",1610.02489v1
2016-10-26,Doping of Ga in antiferromagnetic semiconductor alpha-Cr2O3oxide and its effects on modified magnetic and electronic properties,"The samples of Ga doped Cr2O3 oxide have been prepared using chemical
co-precipitation route. X-ray diffraction pattern and Raman spectra have
confirmed rhombohedral crystal structure with space group R3-C. Magnetic
measurement has indicated the dilution of antiferromagnetic (AFM) spin order in
Ga doped alpha-Cr2O3 system oxide, where the AFM transition temperature of bulk
alpha-Cr2O3 oxide at about 320 K has been suppressed and ferrimagnetic behavior
is observed from the analysis of the temperature dependence of magnetization
data below 350 K. Apart from Ga doping effect, the spin freezing (50 K-70 K)
and superparamagnetic behavior of the surface spins at lower temperatures,
typically below 50 K, have been exhibited due to nano-sized grains of the
samples. All the samples showed non-linear current-voltage (I-V)
characteristics. However, I-V characteristics of the Ga doped samples are
remarkably different from alpha-Cr2O3 sample. The I-V curves of Ga doped
samples have exhibited many unique electronic properties, e.g., bi-stable (low
resistance- LR and high resistance-HR) electronic states and negative
differential resistance (NDR). Optical absorption spectra revealed three
electronic transitions in the samples associated with band gap energy at about
2.67-2.81 eV, 1.91-2.11 eV, 1.28-1.35 eV, respectively.",1610.08426v1
2017-02-14,Magnetism of monomer MnO and heterodimer FePt@MnO nanoparticles,"We report about the magnetic properties of antiferromagnetic (AF) MnO
nanoparticles (NPs) with different sizes (6-19nm). Using a combination of
polarized neutron scattering and magnetometry we were able to resolve
previously observed peculiarities. Magnetometry, on the one hand, reveals a
peak in the zero field cooled (ZFC) magnetization curves at low temperatures
(~25K) but no feature around the N\'eel temperature at 118K. On the other hand,
polarized neutron scattering shows the expected behavior of the AF order
parameter vanishing around 118K. Moreover, hysteresis curves measured at
various temperatures reveal an exchange bias effect indicating a coupling of an
AF core to a ferromagnetic (FM)-like shell. ZFC data measured at various fields
exclude a purely superparamagnetic (SPM) scenario. We conclude that the
magnetic behavior of MnO particles can be explained by a superposition of
SPM-like thermal fluctuations of the AF-N\'eel vector inside the AF core and a
strong magnetic coupling to a ferrimagnetic Mn$_2$O$_3$ or Mn$_3$O$_4$ shell.
In addition, we have studied heterodimer ('Janus') particles, where a FM FePt
particle is attached to the AF MnO particle. Via the exchange bias effect, the
magnetic moment of the FePt subunit is stabilized by the MnO.",1702.04312v1
2017-02-17,Origin of magnetic frustration in Bi$_3$Mn$_4$O$_{12}$(NO$_3$),"Bi$_3$Mn$_4$O$_{12}$(NO$_3$) (BMNO) is a honeycomb bilayers anti-ferromagnet,
not showing any ordering down to very low temperatures despite having a
relatively large Curie-Weiss temperature. Using ab initio density functional
theory, we extract an effective spin Hamiltonian for this compound. The
proposed spin Hamiltonian consists of anti-ferrimagnetic Heisenberg terms with
coupling constants ranging up to third intra-layer and fourth inter-layer
neighbors. Performing Monte Carlo simulation, we obtain the temperature
dependence of magnetic susceptibility and so the Curie-Weiss temperature and
find the coupling constants which best matches with the experimental value. We
discover that depending on the strength of the interlayer exchange couplings,
two collinear spin configurations compete with each other in this system. Both
states have in plane N{\'e}el character, however, at small interlayer coupling
spin directions in the two layers are antiparallel (N$_1$ state) and
discontinuously transform to parallel (N$_2$ state) by enlarging the interlayer
couplings at a first order transition point. Classical Monte Carlo simulation
and density matrix renormalization group calculations confirm that exchange
couplings obtained for BMNO are in such a way that put this material {at the
phase boundary of a first order phase transition}, where the trading between
these two collinear spin states prevents it from setting in a magnetically
ordered state.",1702.05255v2
2017-03-02,Diversity of quantum ground states and quantum phase transitions of a spin-1/2 Heisenberg octahedral chain,"The spin-1/2 Heisenberg octahedral chain with regularly alternating monomeric
and square-plaquette sites is investigated using various analytical and
numerical methods: variational technique, localized-magnon approach, exact
diagonalization (ED) and density-matrix renormalization group (DMRG) method.
The model belongs to the class of flat-band systems and it has a rich
ground-state phase diagram including phases with spontaneously broken
translational symmetry. Moreover, it exhibits an anomalous low-temperature
thermodynamics close to continuous or discontinuous field-driven quantum phase
transitions between three quantum ferrimagnetic phases, tetramer-hexamer phase,
monomer-tetramer phase, localized-magnon phase and two different spin-liquid
phases. If the intra-plaquette coupling is at least twice as strong as the
monomer-plaquette coupling, the variational method furnishes a rigorous proof
of the monomer-tetramer ground state in a low-field region and the
localized-magnon approach provides an exact evidence of a single magnon trapped
at each square plaquette in a high-field region. In the rest of parameter space
we have numerically studied the ground-state phase diagram and magnetization
process using DMRG and ED methods. It is shown that the zero-temperature
magnetization curve may involve up to four intermediate plateaus at zero,
one-fifth, two-fifth and three-fifth of the saturation magnetization, while the
specific heat exhibits a striking low-temperature peak in a vicinity of
discontinuous quantum phase transitions.",1703.00715v2
2017-03-31,Giant Ferrimagnetism and Polarization in a Mixed Metal Perovskite Metal-Organic Framework,"Perovskite metal-organic frameworks (MOFs) have recently emerged as potential
candidates for multiferroicity. However, the compounds synthesized so far
possess only weak ferromagnetism and low polarization. Additionally, the very
low magnetic transition temperatures ($T_c$) also pose a challenge to the
application of the materials. We have computationally designed a mixed metal
perovskite MOF -[C(NH2)3][(Cu0.5Mn0.5)(HCOO)3]- that is predicted to have
magnetization two orders of magnitude larger than its parent
([C(NH2)3][Cu(HCOO)3]), a significantly larger polarization (9.9 {\mu}C/cm2),
and an enhanced $T_c$ of up to 56 K, unprecedented in perovskite MOFs. A
detailed study of the magnetic interactions revealed a novel mechanism leading
to the large moments as well as the increase in the $T_c$. Mixing a
non-Jahn-Teller ion (Mn$^{2+}$) into a Jahn-Teller host (Cu$^{2+}$) leads to
competing lattice distortions which are possibly responsible for the enhanced
polarization. The MOF is thermodynamically stable as evidenced by the computed
enthalpy of formation, and can likely be synthesized. Our work represents a
first step towards rational design of multiferroic perovskite MOFs through the
largely unexlpored mixed metal approach.",1703.10853v3
2017-08-13,Quantum percolation phase transition and magneto-electric dipole glass in hexagonal ferrites,"Hexagonal ferrites do not only have enormous commercial impact ({\pounds}2
billion/year in sales) due to applications that include ultra-high density
memories, credit card stripes, magnetic bar codes, small motors and low-loss
microwave devices, they also have fascinating magnetic and ferroelectric
quantum properties at low temperatures. Here we report the results of tuning
the magnetic ordering temperature in PbFe$_{12-x}$Ga$_x$O$_{19}$ to zero by
chemical substitution $x$. The phase transition boundary is found to vary as
$T_N \sim (1-x/x_c)^{2/3}$ with $x_c$ very close to the calculated spin
percolation threshold which we determine by Monte Carlo simulations, indicating
that the zero-temperature phase transition is geometrically driven. We find
that this produces a form of compositionally-tuned, insulating, ferrimagnetic
quantum criticality. Close to the zero temperature phase transition we observe
the emergence of an electric-dipole glass induced by magneto-electric coupling.
The strong frequency behaviour of the glass freezing temperature $T_m$ has a
Vogel-Fulcher dependence with $T_m$ finite, or suppressed below zero in the
zero frequency limit, depending on composition $x$. These quantum-mechanical
properties, along with the multiplicity of low-lying modes near to the
zero-temperature phase transition, are likely to greatly extend applications of
hexaferrites into the realm of quantum and cryogenic technologies.",1708.03945v1
2018-02-13,Quadratic magnetooptic spectroscopy setup based on photoelastic light modulation,"In most of the cases the magnetooptic Kerr effect (MOKE) techniques rely
solely on the effects linear in magnetization ($\bm{M}$). Nevertheless, a
higher-order term being proportional to $\bm{M}$$^2$ and called quadratic MOKE
(QMOKE) can additionally contribute to experimental data. Handling and
understanding the underlying origin of QMOKE could be the key to utilize this
effect for investigation of antiferromagnetic materials in the future due to
their vanishing first order MOKE contribution. Also, better understanding of
QMOKE and hence better understanding of magnetooptic (MO) effects in general is
very valuable, as the MO effect is very much employed in research of ferro- and
ferrimagnetic materials. Therefore, we present our QMOKE and longitudinal MOKE
spectroscopy setup with a spectral range of 0.8--5.5\,eV. The setup is based on
light modulation through a photoelastic modulator and detection of
second-harmonic intensity by a lock-in amplifier. To measure the Kerr
ellipticity an achromatic compensator is used within the setup, whereas without
it Kerr rotation is measured. The separation of QMOKE spectra directly from the
measured data is based on measurements with multiple magnetization directions.
So far the QMOKE separation algorithm is developed and tested for but not
limited to cubic (001) oriented samples. The QMOKE spectra yielded by our setup
arise from two quadratic MO parameters $G_s$ and $2G_{44}$, being elements of
quadratic MO tensor $\bm{G}$, which describe perturbation of the permittivity
tensor in the second order in $\bm{M}$.",1802.04717v1
2018-02-20,Ultrafast magnetization dynamics in pure and doped Heusler and inverse Heusler alloys,"By using a multiscale approach based on first-principles density functional
theory combined with atomistic spin dynamics, we investigate the electronic
structure and magnetization dynamics of an inverse Heusler and a Heusler
compound and their alloys, i. e. Mn$_{2-x}Z_x$CoAl and Mn$_{2-x}Z_x$VAl, where
$Z$ = Mo, W, Os and Ru, respectively. A signature of the ferrimagnetic ordering
of Mn$_{2}$CoAl and Mn$_{2}$VAl Heusler alloys is reflected in the calculated
Heisenberg exchange constants. They decay very rapidly with the interatomic
distance and have short range, which is a consequence of the existence of the
finite gap in the minority spin band. The calculated Gilbert damping parameter
of both Mn$_2$CoAl and Mn$_2$VAl is high compared to other half-metals, but
interestingly in the particular case of the inverse Mn$_{2}$CoAl alloys and due
to the spin-gapless semiconducting property, the damping parameters decrease
with the doping concentration in clear contradiction to the general trend.
Atomistic spin dynamics simulations predict ultrafast magnetisation switching
in Mn$_{2}$CoAl and Mn$_{2}$VAl under the influence of an external magnetic
field, starting from a threshold field of $2\text{T}$. Our overall finding
extends with Heusler and inverse Heusler alloys, the class of materials that
exhibits laser induced magnetic switching.",1802.07195v1
2018-04-04,Heterobimetallic Dy-Cu coordination compound as a classical-quantum ferrimagnetic chain of regularly alternating Ising and Heisenberg spins,"A classical-quantum chain composed of regularly alternating Ising and
Heisenberg spins is rigorously solved by considering two distinct local
anisotropy axes of the Ising spins. The ground-state phase diagram and
magnetization curves are examined depending on a spatial orientation of the
applied magnetic field. The phase diagram totally consists of four distinct
phases and a few macroscopically degenerate points, where an outstanding
coexistence of perfect order and complete disorder occurs within the so-called
'half-fire, half-ice' state. The zero-temperature magnetization curves
generally exhibit a smooth dependence on a magnetic field owing to a canting
angle between two coplanar anisotropy axes of the Ising spins, which enforces a
misalignment of the magnetization vector from a direction of the applied
magnetic field. It is evidenced that the investigated spin-chain model
reproduces magnetic features of the heterobimetallic coordination compound
Dy(NO)$_{3}$(DMSO)$_{2}$Cu(opba)(DMSO)$_{2}$ (DMSO=dimethylsulfoxide,
opba=orthophenylenebisoxamato). The high-field magnetization data reported for
the powder sample of this polymeric coordination compound generally display a
substantial smoothing on account of a powder averaging.",1804.01551v2
2018-04-06,Effect of Substrate Temperature on Structural and Magnetic Properties of c-axis Ori-ented Spinel Ferrite Ni0.65Zn0.35Fe2O4 (NZFO) Thin Films,"Varying the substrate temperature changes structural and magnetic properties
of spinel ferrite NZFO thin films. XRD of films grown at different temperature
display only 004 reflections, without any secondary peaks, showing growth
orientation along the c axis. We find an increase in crystalline quality of
these thin films with the rise of substrate temperature. The surface topography
of the thin films grown on various growth temperatures conditions reveal that
these films are smooth with low roughness, however the thin films grown at 800
C exhibit lowest average and rms roughness among all thin films. We find iron
and nickel to be more oxidized i,e greater Fe and Ni content in films grown and
annealed at 700 C and 800 C, compared to those grown at lower temperatures. The
magnetic moment is observed to increase with an increase of substrate
temperature and all thin films possess high saturation magnetization and low
coercive field at room temperature. Films grown at 800 C exhibit a
ferrimagnetic paramagnetic phase transition well above room temperature. The
observed large magnetizations with soft magnetic behavior in NZFO thin films
above room temperature suggest potential application in memory, spintronics,
and multifunctional devices.",1804.02458v2
2018-11-10,Magnetic Order and Lattice Instabilities in Ni$_{2}$Mn$_{1+x}$Sn$_{1-x}$ Heusler based Magnetic Shape-Memory Alloys,"The magnetic correlations in the austenite phase and the consequent
martensitic transition in inverse magnetocaloric alloys,
Ni$_{2}$Mn$_{1+x}$Sn$_{1-x}$, have been a matter of debate for decades. We
conclusively establish using {\it ab initio} phonon calculations that the spin
alignment of excess Mn at the Sn site (Mn$_{Sn}$) with the existing Mn in the
unit cell in the high temperature cubic phase of Ni-Mn-Sn alloy is
ferromagnetic (FM), and not ferrimagnetic (FI), resolving a long lasting
controversy. Using first principles density functional perturbation theory
(DFPT), we observe an instability of the TA$_{2}$ mode along the $\Gamma$-M
direction in the FM phase, very similar to that observed in the prototypical
ferromagnetic shape memory alloy (FSMA) Ni$_{2}$MnGa. This specific instability
is not observed in the FI phase. Further finite temperature first principles
lattice dynamics calculations reveal that at 300 K the FM phase becomes
mechanically stable, while the FI phase continue to remain unstable providing
credence to the fact that the high-temperature phase has FM order. These
results will be primordial to understand the magneto-structural properties of
this class of compounds.",1811.04221v1
2018-11-19,A magnetocaloric study of the magnetostructural transitions in NiCr$_2$O$_4$,"The spinel NiCr$_2$O$_4$ is known to show a ferrimagnetic transition at $T_c
= 70$~K, and magneto-structural transitions at $T_s = 30$~K and $T_o = 20$~K\@.
We present a detailed magnetic and magnetocaloric effect (MCE $= -\Delta
S_{M}(T)$) study across these transitions. The $-\Delta S_{M}(T)$ shows a
positive anomaly at $T_c$, $T_s$, and $T_o$. In addition to these anomalies, we
report a new unreported feature at $T \approx 8.5$~K where $-\Delta S_{M}(T)$
shows a negative anomaly or the inverse MCE. An Arrot plot of the isothermal
magnetization data reveals important information about the nature of the
possible phases revealed in $-\Delta S_{M}(T)$. We have also made a scaling
analysis of the $-\Delta S_{M}(T)$ data around these transitions. This analysis
suggests that the transition at $T_c$ is a second-order Mean field like
transition, the transition at $T_s$ is not second order and is non-mean field
like, while the new transition at $T = 8.5$~K is non-mean field like but is
second order in nature. Our study demonstrates that magnetocaloric effect is
sensitive to magneto-structural changes in materials and can be used for the
identification of new phases and transitions.",1811.07836v1
2019-05-09,Spin-Hall Topological Hall Effect in Highly Tunable Pt/Ferrimagnetic-Insulator Bilayers,"Electrical detection of topological magnetic textures such as skyrmions is
currently limited to conducting materials. While magnetic insulators offer key
advantages for skyrmion technologies with high speed and low loss, they have
not yet been explored electrically. Here, we report a prominent topological
Hall effect in Pt/Tm$_3$Fe$_5$O$_{12}$ bilayers, where the pristine
Tm$_3$Fe$_5$O$_{12}$ epitaxial films down to 1.25 unit cell thickness allow for
tuning of topological Hall stability over a broad range from 200 to 465 K
through atomic-scale thickness control. Although Tm$_3$Fe$_5$O$_{12}$ is
insulating, we demonstrate the detection of topological magnetic textures
through a novel phenomenon: 'spin-Hall topological Hall effect' (SH-THE), where
the interfacial spin-orbit torques allow spin-Hall-effect generated spins in Pt
to experience the unique topology of the underlying skyrmions in
Tm$_3$Fe$_5$O$_{12}$. This novel electrical detection phenomenon paves a new
path for utilizing a large family of magnetic insulators in future skyrmion
technologies.",1905.03650v1
2019-05-10,Magnetic tunnel junctions with a B2-ordered CoFeCrAl equiatomic Heusler alloy,"The equiatomic quaternary Heusler alloy CoFeCrAl is a candidate material for
spin-gapless semiconductors (SGSs). However, to date, there have been no
experimental attempts at fabricating a junction device. This paper reports a
fully epitaxial (001)-oriented MgO barrier magnetic tunnel junction (MTJ) with
CoFeCrAl electrodes grown on a Cr buffer. X-ray and electron diffraction
measurements show that the (001) CoFeCrAl electrode films with atomically flat
surfaces have a $B2$-ordered phase. The saturation magnetization is 380
emu/cm$^3$, almost the same as the value given by the Slater--Pauling--like
rule, and the maximum tunnel magnetoresistance ratios at 300 K and 10 K are 87%
and 165%, respectively. Cross-sectional electron diffraction analysis shows
that the MTJs have MgO interfaces with fewer dislocations. The temperature- and
bias-voltage-dependence of the transport measurements indicates magnon-induced
inelastic electron tunneling overlapping with the coherent electron tunneling.
X-ray magnetic circular dichroism (XMCD) measurements show a ferromagnetic
arrangement of the Co and Fe magnetic moments of $B2$-ordered CoFeCrAl, in
contrast to the ferrimagnetic arrangement predicted for the $Y$-ordered state
possessing SGS characteristics. Ab-initio calculations taking account of the
Cr-Fe swap disorder qualitatively explain the XMCD results. Finally, the effect
of the Cr-Fe swap disorder on the ability for electronic states to allow
coherent electron tunneling is discussed.",1905.04070v1
2020-07-08,"Probing low temperature non-equilibrium magnetic state in Co$_{2.75}$Fe$_{0.25}$O$_{4+δ}$ spinel oxide using dc magnetization, ac susceptibility and neutron diffraction experiments","The low temperature lattice structure and magnetic properties of
Co$_{2.75}$Fe$_{0.25}$O$_4$ ferrite have been investigated using experimental
results from synchrotron x-ray diffraction (SXRD), dc magnetization, ac
susceptibility, neutron diffraction and neutron depolarization techniques. The
samples have been prepared by chemical co-precipitation of the Fe and Co
nitrates solution in high alkaline medium and subsequent thermal annealing of
the precipitates in the temperature range of 200- 900 $^\circ$C. Rietveld
refinement of the SXRD patterns at room temperature indicated two-phased cubic
spinel structure for the samples annealed at temperatures 200-600 $^\circ$C.
The samples annealed at temperatures 700 $^\circ$C and 900 $^\circ$C (CF90)
have been best fitted with single phased lattice structure. Refinement of the
neutron diffraction patterns in the temperature range of 5-300 K confirmed
antiferromagnetic (AFM) Co$_3$O$_4$ and ferrimagnetic (FIM)
Co$_{2.75}$Fe$_{0.25}$O$_4$ phases for the sample annealed at 600 $^\circ$C and
single FIM phase of Co$_{2.75}$Fe$_{0.25}$O$_4$ for the CF90 sample. Magnetic
measurements have shown a non-equilibrium magnetic structure, consisting of the
high temperature FIM phase and low temperature AFM phase. The magnetic phases
are sensitive to magnetic fields, where high temperature phase is suppressed at
higher magnetic fields by enhancing the low temperature AFM phase, irrespective
of annealing temperature of the samples.",2007.03906v1
2020-07-25,Direct Visualization of Irreducible Ferrielectricity in Crystals,"In solids, charge polarity can one-to-one correspond to spin polarity
phenomenologically, e.g. ferroelectricity/ferromagnetism,
antiferroelectricity/antiferromagnetism, and even
dipole-vortex/magnetic-vortex, but ferrielectricity/ferrimagnetism kept telling
a disparate story in microscopic level. Since the definition of a charge dipole
involves more than one ion, there may be multiple choices for a dipole unit,
which makes most ferrielectric orders equivalent to ferroelectric ones, i.e.
this ferrielectricity is not necessary to be a real independent branch of
polarity. In this work, by using the spherical aberration-corrected scanning
transmission electron microscope, we visualize a nontrivial ferrielectric
structural evolution in BaFe2Se3, in which the development of two polar
sub-lattices is out-of-sync, for which we term it as irreducible
ferrielectricity. Such irreducible ferrielectricity leads to a non-monotonic
behavior for the temperature-dependent polarization, and even a compensation
point in the ordered state. Our finding unambiguously distinguishes
ferrielectrics from ferroelectrics in solids.",2007.12828v1
2020-07-30,Coexistence of distinct skyrmion phases observed in hybrid ferromagnetic/ferrimagnetic multilayers,"Materials hosting magnetic skyrmions at room temperature could enable new
computing architectures as well as compact and energetically efficient magnetic
storage such as racetrack memories. In a racetrack device, information is coded
by the presence/absence of magnetic skyrmions forming a chain that is moved
through the device. The skyrmion Hall effect that would eventually lead to an
annihilation of the skyrmions at the edges of the racetrack can be suppressed
for example by anti-ferromagnetically-coupled skyrmions. However, avoiding
modifications of the inter-skyrmion distances in the racetrack remains
challenging. As a solution to this issue, a chain of bits could also be encoded
by two different solitons such as a skyrmion and a chiral bobber. The major
limitation of this approach is that it has solely been realized in B20-type
single crystalline material systems that support skyrmions only at low
temperatures, thus hindering the efficacy for future applications. Here we
demonstrate that a hybrid ferro/ferri/ferromagnetic multilayer system can host
two distinct skyrmion phases at room temperature. By matching quantitative
magnetic force microscopy data with micromagnetic simulations, we reveal that
the two phases represent tubular skyrmions and partial skyrmions (similar to
skyrmion bobbers). Furthermore, the tubular skyrmion can be converted into a
partial skyrmion. Such multilayer systems may thus serve as a platform for
designing skyrmion memory applications using distinct types of skyrmions and
potentially for storing information using the vertical dimension in a thin film
device.",2007.15427v1
2013-08-17,Thickness and power dependence of the spin-pumping effect in Y3Fe5O12/Pt heterostructures measured by the inverse spin Hall effect,"The dependence of the spin-pumping effect on the yttrium iron garnet
(Y3Fe5O12, YIG) thickness detected by the inverse spin Hall effect (ISHE) has
been investigated quantitatively. Due to the spin-pumping effect driven by the
magnetization precession in the ferrimagnetic insulator YIG film a
spin-polarized electron current is injected into the Pt layer. This spin
current is transformed into electrical charge current by means of the ISHE. An
increase of the ISHE-voltage with increasing film thickness is observed and
compared to the theoretically expected behavior. The effective damping
parameter of the YIG/Pt samples is found to be enhanced with decreasing YIG
film thickness. The investigated samples exhibit a spin mixing conductance of
g=(7.43 \pm 0.36) \times 10^{18} m^{-2} and a spin Hall angle of theta_{ISHE} =
0.009 \pm 0.0008. Furthermore, the influence of nonlinear effects on the
generated voltage and on the Gilbert damping parameter at high excitation
powers are revealed. It is shown that for small YIG film thicknesses a
broadening of the linewidth due to nonlinear effects at high excitation powers
is suppressed because of a lack of nonlinear multi-magnon scattering channels.
We have found that the variation of the spin-pumping efficiency for thick YIG
samples exhibiting pronounced nonlinear effects is much smaller than the
nonlinear enhancement of the damping.",1308.3787v1
2013-08-25,Enhanced ferromagnetic moment in Co-doped BiFeO3 thin films studied by soft X-ray circular dichroism,"BiFeO$_3$ (BFO) shows both ferroelectricity and magnetic ordering at room
temperature but its ferromagnetic component, which is due to spin canting, is
negligible. Substitution of transition-metal atoms such as Co for Fe is known
to enhance the ferromagnetic component in BFO. In order to reveal the origin of
such magnetization enhancement, we performed soft x-ray absorption spectroscopy
(XAS) and soft x-ray magnetic circular dichroism (XMCD) studies of
BiFe$_{1-x}$Co$_x$O$_3$ ({\it x} = 0 to 0.30) (BFCO) thin films grown on
LaAlO$_3$(001) substrates. The XAS results indicated that the Fe and Co ions
are in the Fe$^{3+}$ and Co$^{3+}$ states. The XMCD results showed that the Fe
ions show ferromagnetism while the Co ions are antiferromagnetic at room
temperature. The XAS and XMCD measurements also revealed that part of the
Fe$^{3+}$ ions are tetrahedrally co-ordinated by oxygen ions but that the XMCD
signals of the octahedrally coordinated Fe$^{3+}$ ions increase with Co
content. The results suggest that an impurity phase such as the ferrimagnetic
$\gamma$-Fe$_2$O$_3$ which exists at low Co concentration decreases with
increasing Co concentration and that the ferromagnetic component of the
Fe$^{3+}$ ion in the octrahedral crystal fields increases with Co
concentration, probably reflecting the increased canting of the Fe$^{3+}$ ions.",1308.5672v1
2014-03-12,The quantum origins of skyrmions and half-skyrmions in Cu2OSeO3,"The Skyrme-particle, the $skyrmion$, was introduced over half a century ago
and used to construct field theories for dense nuclear matter. But with
skyrmions being mathematical objects - special types of topological solitons -
they can emerge in much broader contexts. Recently skyrmions were observed in
helimagnets, forming nanoscale spin-textures that hold promise as information
carriers. Extending over length-scales much larger than the inter-atomic
spacing, these skyrmions behave as large, classical objects, yet deep inside
they are of quantum origin. Penetrating into their microscopic roots requires a
multi-scale approach, spanning the full quantum to classical domain. By
exploiting a natural separation of exchange energy scales, we achieve this for
the first time in the skyrmionic Mott insulator Cu$_2$OSeO$_3$. Atomistic ab
initio calculations reveal that its magnetic building blocks are strongly
fluctuating Cu$_4$ tetrahedra. These spawn a continuum theory with a skyrmionic
texture that agrees well with reported experiments. It also brings to light a
decay of skyrmions into half-skyrmions in a specific temperature and magnetic
field range. The theoretical multiscale approach explains the strong
renormalization of the local moments and predicts further fingerprints of the
quantum origin of magnetic skyrmions that can be observed in Cu$_2$OSeO$_3$,
like weakly dispersive high-energy excitations associated with the Cu$_4$
tetrahedra, a weak antiferromagnetic modulation of the primary ferrimagnetic
order, and a fractionalized skyrmion phase.",1403.2921v1
2016-11-28,Synthesis of low-moment CrVTiAl: a potential room temperature spin filter,"The efficient production of spin-polarized currents at room temperature is
fundamental to the advancement of spintronics. Spin-filter materials ---
semiconductors with unequal band gaps for each spin channel --- can generate
spin-polarized current without the need for spin-polarized contacts. In
addition, a spin-filter material with zero magnetic moment would have the
advantage of not producing strong fringing fields that would interfere with
neighboring electronic components and limit the volume density of devices. The
quaternary Heusler compound CrVTiAl has been predicted to be a zero-moment
spin-filter material with a Curie temperature in excess of 1000 K. In this
work, CrVTiAl has been synthesized with a lattice constant of $a = 6.15 \AA$.
Magnetization measurements reveal an exceptionally low moment of $\mu = 2.3
\times 10^{-3} \mu_B/f.u.$ at a field of $\mu_0 H = 2 T$, that is independent
of temperature between T = 10 K and 400 K, consistent with the predicted
zero-moment ferrimagnetism. Transport measurements reveal a combination of
metallic and semiconducting components to the resistivity. Combining a
zero-moment spin-filter material with nonmagnetic electrodes would lead to an
essentially nonmagnetic spin injector. These results suggest that CrVTiAl is a
promising candidate for further research in the field of spintronics.",1611.09307v3
2017-04-20,Orbital and spin ordering physics of the Mn$_3$O$_4$ spinel,"Motivated by recent experiments, we present a comprehensive theoretical study
of the geometrically frustrated strongly correlated magnetic insulator
Mn$_3$O$_4$ spinel oxide based on a microscopic Hamiltonian involving lattice,
spin and orbital degrees of freedom. Possessing the physics of degenerate e$_g$
orbitals, this system shows a strong Jahn-Teller effect at high temperatures.
Further, careful attention is paid to the special nature of the superexchange
physics arising from the 90$^o$ Mn-O-Mn bonding angle. The Jahn-Teller and
superexchange-based orbital-spin Hamiltonians are then analysed in order to
track the dynamics of orbital and spin ordering. We find that a
high-temperature structural transition results in orbital ordering whose nature
is mixed with respect to the two originally degenerate $e_{g}$ orbitals. This
ordering of orbitals is shown to relieve the intrinsic geometric frustration of
the spins on the spinel lattice, leading to ferrimagnetic Yafet-Kittel ordering
at low-temperatures. Finally, we develop a model for a magnetoelastic coupling
in Mn$_3$O$_4$, enabling a systematic understanding of the experimentally
observed complexity in the low-temperature structural and magnetic
phenomenology of this spinel. Our analysis predicts that a quantum
fluctuation-driven orbital-spin liquid phase may be stabilised at low
temperatures upon the application of pressure.",1704.06026v1
2018-05-03,Spin Canting and Orbital Order in Spinel Vanadate Thin Films,"We report on the epitaxial film growth and characterization of CoV$_2$O$_4$,
a near-itinerant spinel vanadate, grown on (001) SrTiO$_3$. The symmetry
lowering of the unit cell from cubic in the bulk to orthorhombic in the films
results in dramatic differences in the magnetic anisotropy compared to bulk, as
determined from structural and magnetic characterization. Bulk cubic
CoV$_2$O$_4$ has been found to defy predictions by showing orbital degeneracy
seemingly lasting to very low temperatures, with only small anomalies in
magnetization and neutron experiments signaling a possible spin/orbital glass
transition at T = 90 K. In epitaxial thin films presented in this paper,
structurally tuning the CoV$_2$O$_4$ away from cubic symmetry leads to a
completely different low temperature non-collinear ground state. Via
magnetization and neutron scattering measurements we show that the 90 K
transition is associated with a major spin reorientation away from the
ferrimagnetic easy axis [001] to the [110] direction. Furthermore, the V-spins
cant away from this direction with extracted perpendicular moments providing
evidence of a larger canting angle compared to bulk. This result indicates that
compressive strain pushes the system deeper into the insulating state, i.e.,
away from the localized - itinerant crossover regime.",1805.01520v1
2018-05-24,Antiferromagnetically assisted electron-phonon coupling and spin-lattice interaction in Fe-based superconductors,"We present a theoretical ab-initio approach that allows us to explicitly
calculate the superconducting transition temperatures (Tc) of the iron-based
superconductors of LaFeAsO1-xFx, SmFeAsO1-xFx, NdFeAsO1-xFx, Ba1-xKxFe2As2,
FeSe and LiFeAs that fit perfectly with the experiments. We consider recent
evidence that electron-phonon coupling may have been underestimated previously,
and a prediction that antiferromagnetism can greatly enhance electron-phonon
coupling through localized iron d orbitals. We then include the contribution of
these localized orbitals in a McMillan formalism. In addition, we take into
account the spin-lattice interaction between the spin-polarized electrons at
the Fermi surface and the iron orbitals in combination with a modified exchange
Hamiltonian involving a ferrimagnetic coupling between Fe and As. With this
approach we can accurately calculate the Tc of FeSe (11 family), LiFeAs (111
family), LaFeAsO0.9F0.1 (1111 family) and BaFe2As2 (122 family) as a function
of pressure. In addition, we also obtain the correct doping dependence of Tc of
LaFeAsO0.9F0.1 (1111 family) and BaFe2As2 (122 family).",1805.09754v5
2013-09-09,FeCr$_2$S$_4$ in magnetic fields: possible evidence for a multiferroic ground state,"We report on neutron diffraction, thermal expansion, magnetostriction,
dielectric, and specific heat measurements on polycrystalline FeCr2S4 in
external magnetic fields. The ferrimagnetic ordering temperatures
$T_{\mathrm{C}}\approx 170$ K and the transition at $T_{\mathrm{OO}}\approx 10$
K, which has been associated with orbital ordering, are only weakly shifted in
magnetic fields up to 9 T. The cubic lattice parameter is found to decrease
when entering the state below $T_{\mathrm{OO}}$. The magnetic moments of the
Cr- and Fe-ions are reduced from the spin-only values throughout the
magnetically ordered regime, but approach the spin-only values for fields
$>$5.5 T. Thermal expansion in magnetic fields and magnetostriction experiments
indicate a contraction of the sample below about 60 K. Below $T_{\mathrm{OO}}$
this contraction is followed by a moderate expansion of the sample for fields
larger than $\sim$4.5 T. The transition at $T_{\mathrm{OO}}$ is accompanied by
an anomaly in the dielectric constant. The dielectric constant depends on both
the strength and orientation of the external magnetic field with respect to the
applied electric field for $T<T_{\mathrm{OO}}$. A linear correlation of the
magnetic-field-induced change of the dielectric constant and the magnetic-field
dependent magnetization is observed. This behaviour is consistent with the
existence of a ferroelectric polarization and a multiferroic ground state below
10 K.",1309.2140v2
2015-12-11,Ultra-low magnetic damping of a metallic ferromagnet,"The phenomenology of magnetic damping is of critical importance for devices
that seek to exploit the electronic spin degree of freedom since damping
strongly affects the energy required and speed at which a device can operate.
However, theory has struggled to quantitatively predict the damping, even in
common ferromagnetic materials. This presents a challenge for a broad range of
applications in spintronics and spin-orbitronics that depend on materials and
structures with ultra-low damping. Such systems enable many experimental
investigations that further our theoretical understanding of numerous magnetic
phenomena such as damping and spin-transport mediated by chirality and the
Rashba effect. Despite this requirement, it is believed that achieving
ultra-low damping in metallic ferromagnets is limited due to the scattering of
magnons by the conduction electrons. However, we report on a binary alloy of Co
and Fe that overcomes this obstacle and exhibits a damping parameter
approaching 0.0001, which is comparable to values reported only for
ferrimagnetic insulators. We explain this phenomenon by a unique feature of the
bandstructure in this system: The density of states exhibits a sharp minimum at
the Fermi level at the same alloy concentration at which the minimum in the
magnetic damping is found. This discovery provides both a significant
fundamental understanding of damping mechanisms as well as a test of
theoretical predictions.",1512.03610v1
2016-05-06,Optically probing symmetry breaking in the chiral magnet Cu2OSeO3,"We report on the linear optical properties of the chiral magnet Cu2OSeO3,
specifically associated with the absence of inversion symmetry, the chiral
crystallographic structure, and magnetic order. Through spectroscopic
ellipsometry, we observe local crystal-field excitations below the
charge-transfer gap. These crystal-field excitations are optically allowed due
to the lack of inversion symmetry at the Cu sites. Optical polarization
rotation measurements were used to study the structural chirality and magnetic
order. The temperature dependence of the natural optical rotation, originating
in the chiral crystal structure, provides evidence for a finite
magneto-electric effect in the helimagnetic phase. We find a large
magneto-optical susceptibility on the order of V(540nm)~10^4 rad/(T*m) in the
helimagnetic phase and a maximum Faraday rotation of ~165deg/mm in the
ferrimagnetic phase. The large value of V can be explained by considering spin
cluster formation and the relative ease of domain reorientation in this
metamagnetic material. The magneto-optical activity allows us to map the
magnetic phase diagram, including the skyrmion lattice phase. In addition to
this, we probe and discuss the nature of the various magnetic phase transitions
in Cu2OSeO3.",1605.01900v1
2016-05-16,A new and simple model for magneto-optics uncovers an unexpected spin switching,"In magneto-optics the spin angular momentum $S_z$ of a sample is indirectly
probed by the rotation angle and ellipticity, which are mainly determined by
the off-diagonal susceptibility $\chi^{(1)}_{xy}$. A direct and analytic
relation between $S_z$ and $\chi^{(1)}_{xy}$ is necessary and of paramount
importance to the success of magneto-optics, but is often difficult to acquire
since quantum mechanically the relation is hidden in the sum-over-states. Here
we propose a new and simple model to establish such a much needed relation. Our
model is based on the Hookean model, but includes spin-orbit coupling. Under cw
excitation, we show that $\chi^{(1)}_{xy}(\omega)$ is indeed directly
proportional to $S_z$ for a fixed photon frequency $\omega$. Such an elegant
relation is encouraging, and we wonder whether our model can describe spin
dynamics as well. By allowing the spin to change dynamically, to our surprise,
our model predicts that an ultrafast laser pulse can induce a spin precession;
with appropriate parameters, the laser can even reverse spin from one direction
to another. This works for both the circularly and linearly polarized light.
The spin reversal window is narrow. These unexpected results closely resemble
all-optical helicity-dependent magnetic switching found in much more
complicated ferrimagnetic rare earth compounds. Therefore, we believe that our
spin-orbit coupled model may find some important applications in spin switching
processes, a hot topic in femtomagnetism.",1605.04847v1
2016-08-06,Frustrated S=1/2 Two-Leg Ladder with Different Leg Interactions,"We explore the ground-state phase diagram of the $S\!=\!1/2$ two-leg ladder
with different isotropic leg interactions and uniform anisotropic rung ones,
which is described by the Hamiltonian ${\cal H}=J_{{\rm l},a}
\sum\nolimits_{j=1}^{L}{\vec S}_{j,a}\cdot {\vec S}_{j+1,a}+J_{{\rm l},b}
\sum\nolimits_{j=1}^{L} {\vec S}_{j,b}\cdot {\vec S}_{j+1,b}+J_{\rm r}
\sum\nolimits_{j=1}^{L} \bigl\{S_{j,a}^x S_{j,b}^x + S_{j,a}^y S_{j,b}^y +
\Delta S_{j,a}^z S_{j,b}^z \bigr\}$. This system has a frustration when
$J_{{\rm l},a} J_{{\rm l},b}\!<\!0$ irrespective of the sign of $J_{\rm r}$.
The phase diagrams on the $\Delta$ ($0\!\leq\!\Delta\!<\!1$) versus $J_{{\rm
l},b}$ plane in the cases of {$J_{{\rm l},a}\!=\!-0.2$ and $J_{{\rm
l},a}\!=\!0.2$ with $J_{{\rm r}}\!=\!-1$ are determined numerically. We employ
the physical consideration, the level spectroscopy analysis of the results
obtained by the exact diagonalization method and also the density-matrix
renormalization-group method. It is found that the non-collinear ferrimagnetic
(NCFR) state appears as the ground state in the frustrated region of the
parameters. Furthermore, the direct-product triplet-dimer (TD) state in which
all rungs form the TD pair is the exact ground state, when $J_{{\rm
l},a}\!+\!J_{{\rm l},b}\!=\!0$ and $0 \leq \Delta \leq 0.83$. The obtained
phase diagrams consist of the TD, $XY$ and Haldane phases as well as the NCFR
phase.",1608.02064v2
2016-08-09,Ground States of Spin-1/2 Heisenberg Antiferromagnets with Frustration on a Diamond-Like Decorated Square Lattice,"We study the ground-state phase diagram of a Heisenberg model with spin
$S=\frac{1}{2}$ on a diamond-like decorated square lattice. A diamond unit has
two types of antiferromagnetic exchange interactions, and the ratio $\lambda$
between the length of the diagonal bond and that of the other four edges
determines the strength of frustration. It has been pointed out [J. Phys. Soc.
Jpn {\bf85}, 033705 (2016)] that the so-called tetramer-dimer states, which are
expected to be stabilized in an intermediate region of $\lambda_{\rm
c}<\lambda<2$, are identical to the square-lattice dimer covering states, which
ignited renewed interest in high-dimensional diamond-like decorated lattices.
In order to determine the phase boundary $\lambda_{\rm c}$, we employ the
modified spin wave method to estimate the energy of the ferrimagnetic state and
obtain $\lambda_{\rm c}=0.974$. Our obtained magnetizations for
spin-$\frac{1}{2}$ sites and for spin-1 sites are $m=0.398$ and
$\tilde{m}=0.949$, and spin reductions are 20 \% and 5\%, respectively. This
indicates that spin fluctuation is much smaller than that of the
$S=\frac{1}{2}$ square-lattice antiferromagnet: thus, we can consider that our
obtained ground-state energy is highly accurate. Further, our numerical
diagonalization study suggests that other cluster states do not appear in the
ground-state phase diagram.",1608.02735v1
2016-08-16,Probing current-induced magnetic fields in Au|YIG heterostructure with low-energy muon spectroscopy,"We investigated the depth dependence of current-induced magnetic fields in a
bilayer of a normal metal (Au) and a ferrimagnetic insulator (Yttrium Iron
Garnet - YIG) by using low energy muon spectroscopy (LE-muSR). This allows us
to explore how these fields vary from the Au surface down to the buried Au|YIG
interface, which is relevant to study physics like the spin-Hall effect. We
observed a maximum shift of 0.4 G in the internal field of muons at the surface
of Au film which is in close agreement to the value expected for Oersted
fields. As muons are implanted closer to the Au|YIG interface the shift is
strongly suppressed, which we attribute to the dipolar fields present at the
Au|YIG interface. Combining our measurements with modelling, we show that
dipolar fields caused by the finite roughness of the Au|YIG interface
consistently explains our observations. Our results, therefore, gauge the
limits on the spatial resolution and the sensitivity of LE-muSR to the
roughness of the buried magnetic interfaces, a prerequisite for future studies
addressing current induced fields caused by the spin-Hall effect.",1608.04584v1
2016-12-15,Ba2NiOsO6: A Dirac-Mott insulator with ferromagnetism near 100 K,"The ferromagnetic semiconductor Ba2NiOsO6 (Tmag ~100 K) was synthesized at 6
GPa and 1500 {\deg}C. It crystallizes into a double perovskite structure
[Fm-3m; a = 8.0428(1) {\AA}], where the Ni2+ and Os6+ ions are perfectly
ordered at the perovskite B-site. We show that the spin-orbit coupling of Os6+
plays an essential role in opening the charge gap. The magnetic state was
investigated by density functional theory calculations and powder neutron
diffraction. The latter revealed a collinear ferromagnetic order in a >21 kOe
magnetic field at 5 K. The ferromagnetic gapped state is fundamentally
different from that of known dilute magnetic semiconductors such as (Ga,Mn)As
and (Cd,Mn)Te (Tmag < 180 K), the spin-gapless semiconductor Mn2CoAl (Tmag ~720
K), and the ferromagnetic insulators EuO (Tmag ~70 K) and Bi3Cr3O11 (Tmag ~220
K). It is also qualitatively different from known ferrimagnetic
insulator/semiconductors, which are characterized by an antiparallel spin
arrangement. Our finding of the ferromagnetic semiconductivity of Ba2NiOsO6
should increase interest in the platinum group oxides, because this new class
of materials should be useful in the development of spintronic, quantum
magnetic, and related devices.",1612.05041v1
2016-12-20,Magnetocrystalline anisotropy of Laves phase Fe$_2$Ta$_{1-x}$W$_x$ from first principles - the effect of 3d-5d hybridisation,"The magnetic properties of Fe$_2$Ta and Fe$_2$W in the hexagonal Laves phase
are computed using density functional theory in the generalised gradient
approximation, with the full potential linearised augmented plane wave method.
The alloy Fe$_2$Ta$_{1-x}$W$_x$ is studied using the virtual crystal
approximation to treat disorder. Fe$_2$Ta is found to be ferromagnetic with a
saturation magnetization of $\mu_0 M_\text{s} = 0.66~\mathrm{T}$ while, in
contrast to earlier computational work, Fe$_2$W is found to be ferrimagnetic
with $\mu_0 M_\text{s} = 0.35~\mathrm{T}$. The transition from the ferri- to
the ferromagnetic state occurs for $x \leq 0.1$. The magnetocrystalline
anisotropy energy (MAE) is calculated to $1.25~\mathrm{MJ/m^3}$ for Fe$_2$Ta
and $0.87~\mathrm{MJ/m^3}$ for Fe$_2$W. The MAE is found to be smaller for all
values $x$ in Fe$_2$Ta$_{1-x}$W$_x$ than for the end compounds and it is
negative (in-plane anisotropy) for $0.1 \leq x \leq 0.9$. The MAE is carefully
analysed in terms of the electronic structure. Even though there are weak 5d
contributions to the density of states at the Fermi energy in both end
compounds, a reciprocal space analysis, using the magnetic force theorem,
reveals that the MAE originates mainly from regions of the Brillouin zone with
strong 3d-5d hybridisation near the Fermi energy. Perturbation theory and its
applicability in relation to the MAE is discussed.",1612.06802v1
2016-12-28,Robust Ferromagnetism in Silicene Nanoflakes through Patterned Hydrogenation,"Considerably different properties emerge in nanomaterials as a result of
quantum confinement and edge effects. In this study, the electronic and
magnetic properties of quasi zero dimensional silicene nanoflakes (SiNFs) are
investigated using first principles calculations. Whilst the zigzag edged
hexagonal SiNFs exhibit nonmagnetic semiconducting character, the zigzag edged
triangular SiNFs are magnetic semiconductors. One effective method of
harnessing the properties of silicene is hydrogenation owing to its
reversibility and controllability. From bare SiNFs to half hydrogenated and
then to fully hydrogenated, a triangular SiNF experiences a change from
ferrimagnetic to very strong ferromagnetic, and then to non-magnetic.
Nonetheless, a hexagonal SiNF undergoes a transfer from nonmagnetic to very
strong ferromagnetic, then to nonmagnetic. The half hydrogenated SiNFs produce
a large spin moment that is directly proportional to the square of the flakes
size. It has been revealed that the strong induced spin magnetizations align
parallel and demonstrates a collective character by large range ferromagnetic
exchange coupling, giving rise to its potential use in spintronic circuit
devices. Spin switch models are offered as an example of one of the potential
applications of SiNFs in tuning the transport properties by controlling the
hydrogen coverage.",1612.09005v4
2017-06-09,Negative spin Hall magnetoresistance of Pt on the bulk easy-plane antiferromagnet NiO,"We report on spin Hall magnetoresistance (SMR) measurements of Pt Hall bars
on the antiferromagnetic NiO(111) single crystal. An SMR with a sign opposite
of conventional SMR is observed over a wide range of temperatures as well as
magnetic fields stronger than 0.25T. The negative sign of the SMR can be
explained by the alignment of magnetic moments being almost perpendicular to
the external magnetic field within the easy plane (111) of the antiferromagnet.
This correlation of magnetic moment alignment and external magnetic field
direction is realized just by the easy-plane nature of the material without the
need of any exchange coupling to an additional ferromagnet. The SMR signal
strength decreases with increasing temperature, primarily due to the decrease
in N\'eel order by including fluctuations. An increasing magnetic field
increases the SMR signal strength as there are less domains and the magnetic
moments are more strongly manipulated at high magnetic fields. The SMR is
saturated at an applied magnetic field of $6$~T resulting in a spin-mixing
conductance of $\sim10^{18}~ \Omega^{-1}$m$^{-2}$, which is comparable to that
of Pt on insulating ferrimagnets such as yttrium iron garnet. An argon plasma
treatment doubles the spin-mixing conductance.",1706.03004v1
2017-06-15,Biaxial-stress driven tetragonal symmetry breaking in and high-temperature ferromagnetic semiconductor from half-metallic CrO2,"It is highly desirable to combine the full spin polarization of carriers with
modern semiconductor technology for spintronic applications. For this purpose,
one needs good crystalline ferromagnetic (or ferrimagnetic) semiconductors with
high Curie temperatures. Rutile CrO$_2$ is a half-metallic spintronic material
with Curie temperature 394 K and can have nearly-full spin polarization at room
temperature. Here, we find through first-principles investigation that when a
biaxial compressive stress is applied on rutile CrO$_2$, the density of states
at the Fermi level decreases with the in-plane compressive strain, there is a
structural phase transition to an orthorhombic phase at the strain of -5.6\%,
and then appears an electronic phase transition to a semiconductor phase at
-6.1\%. Further analysis shows that this structural transition, accompanying
the tetragonal symmetry breaking, is induced by the stress-driven distortion
and rotation of the oxygen octahedron of Cr, and the half-metal-semiconductor
transition originates from the enhancement of the crystal field splitting due
to the structural change. Importantly, our systematic total-energy comparison
indicates the ferromagnetic Curie temperature remains almost independent of the
strain, near 400 K. This biaxial stress can be realized by applying biaxial
pressure or growing the CrO$_2$ epitaxially on appropriate substrates. These
results should be useful for realizing full (100\%) spin polarization of
controllable carriers as one uses in modern semiconductor technology.",1706.04842v3
2017-06-21,Deterministic creation and deletion of a single magnetic skyrmion observed by direct time-resolved X-ray microscopy,"Spintronic devices based on magnetic skyrmions are a promising candidate for
next-generation memory applications due to their nanometre-size,
topologically-protected stability and efficient current-driven dynamics. Since
the recent discovery of room-temperature magnetic skyrmions, there have been
reports of current-driven skyrmion displacement on magnetic tracks and
demonstrations of current pulse-driven skyrmion generation. However, the
controlled annihilation of a single skyrmion at room temperature has remained
elusive. Here we demonstrate the deterministic writing and deleting of single
isolated skyrmions at room temperature in ferrimagnetic GdFeCo films with a
device-compatible stripline geometry. The process is driven by the application
of current pulses, which induce spin-orbit torques, and is directly observed
using a time resolved nanoscale X-ray imaging technique. We provide a
current-pulse profile for the efficient and deterministic writing and deleting
process. Using micromagnetic simulations, we also reveal the microscopic
mechanism of the topological fluctuations that occur during this process.",1706.06726v2
2018-10-12,Electronic structure and magnetic ordering of NiN and Ni$_2$N from first principles,"The results of first-principles electronic structure calculations for the
nitrogen-rich nickel nitrides $ {\rm NiN} $ and $ {\rm Ni_2N} $ are presented.
The calculations are based on density functional theory and used the
generalized gradient approximation (GGA) as well as the GGA$ +U $ approach. The
latter turned out to be crucial for a correct description of the crystal phase
stability and magnetic instabilities of both compounds. While for $ {\rm NiN} $
GGA calculations predict a non-magnetic ground state with the zincblende
structure, GGA$ +U $ calculations result in a half-metallic ferromagnet with
the rocksalt structure in line with indications from the neighboring
transition-metal nitrides making $ {\rm NiN} $ a possible candidate for
spin-filter devices. For $ {\rm Ni_2N} $ GGA calculations likewise lead to a
non-magnetic behavior, which is contrasted with a ferrimagnetic ordering
obtained from the GGA$ +U $ approach. This ground state results from complex
three-dimensional exchange interaction via $ \sigma $-type and $ \pi $-type
overlap of the Ni $ 3d $ orbitals with the N $ 2p $ orbitals and may explain
the reported sensitivity of the magnetic ordering to details of the crystal
structure. For both nitrides, experimental data are called for to confirm our
predictions.",1810.05463v2
2019-06-13,Impact of electromagnetic fields and heat on spin transport signals in Y$_{3}$Fe$_{5}$O$_{12}$,"Exploring new strategies to perform magnon logic is a key requirement for the
further development of magnon-based spintronics. In this work, we realize a
three-terminal magnon transport device to study the possibility of manipulating
magnonic spin information transfer in a magnetic insulator via localized
magnetic fields and heat generation. The device comprises two parallel Pt wires
as well as a Cu center wire that are deposited on the ferrimagnetic insulator
Y$_{3}$Fe$_{5}$O$_{12}$. While the Pt wires act as spin current injector and
detector, the Cu wire is used to create local magnetostatic fields and
additional heat, which impact both the magnetic configuration and the magnons
within the Y$_{3}$Fe$_{5}$O$_{12}$ below. We show that these factors can create
a non-local signal that shows similar features as compared to an electrically
induced magnon flow. Furthermore, a modulation of the spin transport signal
between the Pt wires is observed, which can be partly explained by thermally
excited spin currents of different polarization. Our results indicate a
potential way towards the manipulation of non-local magnon signals, which could
be useful for magnon logic.",1906.05631v2
2019-06-17,Interfacial Dzyaloshinskii-Moriya interaction and chiral magnetic textures in a ferrimagnetic insulator,"The interfacial Dzyaloshinskii-Moriya interaction (DMI) in multilayers of
heavy metal and ferromagnetic metals enables the stabilization of novel chiral
spin structures such as skyrmions. Magnetic insulators, on the other hand can
exhibit enhanced dynamics and properties such as lower magnetic damping and
therefore it is of interest to combine the properties enabled by interfacial
DMI with insulating systems. Here, we demonstrate the presence of interfacial
DMI in heterostructures that include insulating magnetic layers. We use a
bilayer of perpendicularly magnetized insulating thulium iron garnet (TmIG) and
the heavy metal platinum, and find a surprisingly strong interfacial DMI that,
combined with spin-orbit torque results, in efficient switching. The
interfacial origin is confirmed through thickness dependence measurements of
the DMI, revealing the characteristic 1/thickness dependence with one order of
magnitude longer decay length compared to metallic layers. We combine chiral
spin structures and spin-orbit torques for efficient switching and identify
skyrmions that allow us to establish the GGG/TmIG interface as the origin of
the DMI.",1906.07142v3
2019-07-01,Magnetic skyrmion artificial synapse for neuromorphic computing,"Since the experimental discovery of magnetic skyrmions achieved one decade
ago, there have been significant efforts to bring the virtual particles into
all-electrical fully functional devices, inspired by their fascinating physical
and topological properties suitable for future low-power electronics. Here, we
experimentally demonstrate such a device: electrically-operating skyrmion-based
artificial synaptic device designed for neuromorphic computing. We present that
controlled current-induced creation, motion, detection and deletion of
skyrmions in ferrimagnetic multilayers can be harnessed in a single device at
room temperature to imitate the behaviors of biological synapses. Using
simulations, we demonstrate that such skyrmion-based synapses could be used to
perform neuromorphic pattern-recognition computing using handwritten
recognition data set, reaching to the accuracy of ~89 percents, comparable to
the software-based training accuracy of ~94 percents. Chip-level simulation
then highlights the potential of skyrmion synapse compared to existing
technologies. Our findings experimentally illustrate the basic concepts of
skyrmion-based fully functional electronic devices while providing a new
building block in the emerging field of spintronics-based bio-inspired
computing.",1907.00957v2
2019-07-16,"Pressure-Induced Large Volume Collapse, Plane-to-Chain, Insulator to Metal Transition in CaMn$_2$Bi$_2$","In-situ high pressure single crystal X-ray diffraction study reveals that the
quantum material CaMn$_2$Bi$_2$ undergoes a unique plane to chain structural
transition between 2 and 3 GPa, accompanied by a large volume collapse.
CaMn2Bi2 displays a new structure type above 2.3 GPa, with the puckered Mn
honeycomb lattice of the trigonal ambient-pressure structure converting to
one-dimensional (1D) zigzag chains in the high-pressure monoclinic structure.
Single crystal measurements reveal that the pressure-induced structural
transformation is accompanied by a dramatic two order of magnitude drop of
resistivity; although the ambient pressure phase displays semiconducting
behavior at low temperatures, metallic temperature dependent resistivity is
observed for the high pressure phase, as, surprisingly, are two resistivity
anomalies with opposite pressure dependences. Based on the electronic structure
calculations, we hypothesized that the newly emerged electronic state under
high pressure is associated with a Fermi surface instability of the quasi-1D Mn
chains, while we infer that the other is a magnetic transition. Assessment of
the total energies for hypothetical magnetic structures for high pressure
CaMn$_2$Bi$_2$ indicates that ferrimagnetism is thermodynamically favored.",1907.07203v1
2019-09-13,"Structural, magnetic and electric polarization properties of geometrically frustrated YBaCo4O7 and DyBaCo4O7 cobaltites","In RBaCo4O7 (R = Ca, Y and Rare earth) cobaltite family, only CaBaCo4O7 shows
3D long range ferrimagnetic and spin driven electric polarization properties.
In the present study, we have investigated the structural, magnetic and
electric polarization properties in YBaCo4O7 and DyBaCo4O7 members of this
family and the obtained results are compared with the CaBaCo4O7. The compound
YBaCo4O7 showed a series of magnetic transitions in agreement with reported
literature, additionally, a cluster glass behavior below 5 K is observed.
Powder neutron diffraction studies on DyBaCo4O7 cobaltite showed an
orthorhombic Pbn21 symmetry and signature of short-range 120 degree magnetic
correlations of kagome layer and a spin glass behavior below 65 K. Dielectric
measurements on both the samples showed strong frequency dispersion at high
temperature and frequency independent behavior at low temperature without
dielectric anomaly. Pyroelectric current measurement has showed a broad peak
around 50 K in both the samples; however, a careful analysis relates the peak
to thermally stimulated depolarization current. This study signifies that the
giant structural distortions and cobalt charge ordering at kagome layer are the
key factors to drive both long range magnetic ordering and spin driven electric
polarization in this cobaltite family.",1909.06408v2
2019-09-18,Dzyaloshinskii-Moriya coupling in 3d insulators,"We present an overview of the microscopic theory of the Dzyaloshinskii-Moriya
(DM) coupling in strongly correlated 3d compounds. Most attention in the paper
centers around the derivation of the Dzyaloshinskii vector, its value,
orientation, and sense (sign) under different types of the (super)exchange
interaction and crystal field. We consider both the Moriya mechanism of the
antisymmetric interaction and novel contributions, in particular, that of
spin-orbital coupling on the intermediate ligand ions. We have predicted a
novel magnetic phenomenon, {\it weak ferrimagnetism} in mixed weak ferromagnets
with competing signs of the Dzyaloshinskii vectors.
  We revisit a problem of the DM coupling for a single bond in cuprates
specifying the local spin-orbital contributions to Dzyaloshinskii vector
focusing on the oxygen term. We predict a novel puzzling effect of the on-site
staggered spin polarization to be a result of the on-site spin-orbital coupling
and the the cation-ligand spin density transfer. The intermediate ligand NMR
measurements are shown to be an effective tool to inspect the effects of the DM
coupling in an external magnetic field. We predict the effect of a $strong$
oxygen weak antiferromagnetism in edge-shared CuO$_2$ chains due to
uncompensated oxygen Dzyaloshinskii vectors. We revisit the effects of
symmetric spin anisotropy directly induced by the DM coupling. A critical
analysis will be given of different approaches to exchange-relativistic
coupling based on the cluster and the DFT based calculations. Theoretical
results are applied to different classes of 3d compounds from conventional weak
ferromagnets ($\alpha$-Fe$_2$O$_3$, FeBO$_3$, FeF$_3$, RFeO$_3$, RCrO$_3$,.. )
to unconventional systems such as weak ferrimagnets (e.g.,
RFe$_{1-x}$Cr$_x$O$_3$), helimagnets (e.g., CsCuCl$_3$), and parent cuprates
(La$_2$CuO$_4$,...).",1909.08342v1
2019-09-30,Colossal magnetoresistance in the insulating ferromagnetic double perovskites Tl$_2$NiMnO$_6$: A neutron diffraction study,"In the family of double perovskites, colossal magnetoresistance (CMR) has
been so far observed only in half-metallic ferrimagnets such as the known case
Sr$_2$FeMoO$_6$ where it has been assigned to the tunneling MR at grain
boundaries due to the half-metallic nature. Here we report a new
material-Tl$_2$NiMnO$_6$, a relatively ordered double perovskite stablized by
the high pressure and high temperature synthesis-showing CMR in the vicinity of
its Curie temperature. We explain the origin of such effect with neutron
diffraction experiment and electronic structure calculations that reveal the
material is a ferromagnetic insulator. Hence the ordered Tl$_2$NiMnO$_6$ (~70%
of Ni$^{2+}$/Mn$^{4+}$ cation ordering) represents the first realization of a
ferromagnetic insulating double perovskite, showing CMR. The study of the
relationship between structure and magnetic properties allows us to clarify the
nature of spin glass behaviour in the disordered Tl$_2$NiMnO$_6$ (~31% of
cation ordering), which is related to the clustering of antisite defects and
associated with the short-range spin correlations. Our results highlight the
key role of the cation ordering in establishing the long range magnetic ground
state and lay out new avenues to exploit advanced magnetic materials in double
perovskites.",1910.00042v1
2020-02-15,"Understanding high ordering temperature in Gd$_6$FeBi$_2$ magnet: critical behavior, electronic structure and crystal-field analysis","Gd6FeBi2 is reported as the only one room-temperature magnet with a Curie
temperature (Tc) of ca. 350 K among more than hundreds of compounds with its
structural type, which makes it more attractive in potential applications. To
reveal the origin of such high ordering temperature, critical behaviors,
electronic structure and crystal-field effects of Gd6FeBi2 are investigated in
this work. The short-range Gd-Fe ferrimagnetic interaction is supported by the
non-Curie-Weiss paramagnetic behavior, crystal and electronic structure
analyses, in agreement with previous DFT calculations. Unlike the strong TM-TM
exchange interactions, the Gd-Fe exchange interaction shows limited influence
on the critical exponents determined by long-range exchange interactions, which
seems a common feature in RE-TM based alloys without TM-TM exchange
interactions. However, the strong Gd-Fe hybridization reduces the influence of
vibronic couplings on the short-range exchange interaction and thus allows a
high Tc. The broadening or splitting mechanism of Gd 4f-electron bands is
addressed based on crystal-field analysis and likely another factor for
elevated Tc in Gd6FeBi2 and Gd-based compounds with non-magnetic elements.
Different magnetic behaviors among isostructural compounds, and the
relationship between the band splitting and crystal-field effects is also
discussed.",2002.06402v1
2020-02-25,Strain-Tuned Magnetic Anisotropy in Sputtered Thulium Iron Garnet Ultrathin Films and TIG/Au/TIG Valve Structures,"Defining the magnetic anisotropy for in-plane or out-of-plane easy axis in
ferrimagnetic insulators films by controlling the strain, while maintaining
high-quality surfaces, is desirable for spintronic and magnonic applications.
We investigate ways to tune the anisotropy of amorphous sputtered ultrathin
thulium iron garnet (TIG) films, and thus tailor their magnetic properties by
the thickness (7.5 to 60 nm), substrate choice (GGG and SGGG), and
crystallization process. We correlate morphological and structural properties
with the magnetic anisotropy of post-growth annealed films. 30 nm thick films
annealed at 600 {\deg}C show compressive strain favoring an in-plane magnetic
anisotropy (IPMA), whereas films annealed above 800 {\deg}C are under a tensile
strain leading to a perpendicular magnetic anisotropy (PMA). Air-annealed films
present a high degree of crystallinity and magnetization saturation close to
the bulk value. These results lead to successful fabrication of trilayers
TIG/Au/TIG, with coupling between the TIG layers depending on Au thickness.
These results will facilitate the use of TIG to create various in situ clean
hybrid structures for fundamental interface exchange studies, and towards the
development of complex devices. Moreover, the sputtering technique is
advantageous as it can be easily scaled up for industrial applications.",2002.10608v2
2020-02-27,High-temperature Anomalous Hall Effect in Transition Metal Dichalcogenide-Ferromagnetic Insulator Heterostructure,"Integration of transition metal dichalcogenides (TMDs) on ferromagnetic
materials (FM) may yield fascinating physics and promise for electronics and
spintronic applications. In this work, high-temperature anomalous Hall effect
(AHE) in the TMD ZrTe2 thin film using heterostructure approach by depositing
it on ferrimagnetic insulator YIG (Y3Fe5O12, yttrium iron garnet) is
demonstrated. In this heterostructure, significant anomalous Hall effect can be
observed at temperatures up to at least 400 K, which is a record high
temperature for the observation of AHE in TMDs, and the large RAHE is more than
one order of magnitude larger than those previously reported value in
topological insulators or TMDs based heterostructures. The magnetization of
interfacial reaction-induced ZrO2 between YIG and ZrTe2 is believed to play a
crucial role for the induced high-temperature anomalous Hall effect in the
ZrTe2. These results reveal a promising system for the room-temperature
spintronic device applications, and it may also open a new avenue toward
introducing magnetism to TMDs and exploring the quantum AHE at higher
temperatures considering the prediction of nontrivial topology in ZrTe2.",2002.12068v1
2020-04-06,Spin Hall magnetoresistance in antiferromagnetic insulators,"Antiferromagnetic materials promise improved performance for spintronic
applications, as they are robust against external magnetic field perturbations
and allow for faster magnetization dynamics compared to ferromagnets. The
direct observation of the antiferromagnetic state, however, is challenging due
to the absence of a macroscopic magnetization. Here, we show that the spin Hall
magnetoresistance (SMR) is a versatile tool to probe the antiferromagnetic spin
structure via simple electrical transport experiments by investigating the
easy-plane antiferromagnetic insulators $\alpha$-Fe2O3 (hematite) and NiO in
bilayer heterostructures with a Pt heavy metal top electrode. While rotating an
external magnetic field in three orthogonal planes, we record the longitudinal
and the transverse resistivities of Pt and observe characteristic resistivity
modulations consistent with the SMR effect. We analyze both their amplitude and
phase and compare the data to the results from a prototypical collinear
ferrimagnetic Y3Fe5O12/Pt bilayer. The observed magnetic field dependence is
explained in a comprehensive model, based on two magnetic sublattices and
taking into account magnetic field-induced modifications of the domain
structure. Our results show that the SMR allows us to understand the spin
configuration and to investigate magnetoelastic effects in antiferromagnetic
multi-domain materials. Furthermore, in $\alpha$-Fe2O3/Pt bilayers, we find an
unexpectedly large SMR amplitude of $2.5 \times 10^{-3}$, twice as high as for
prototype Y3Fe5O12/Pt bilayers, making the system particularly interesting for
room-temperature antiferromagnetic spintronic applications.",2004.02639v2
2020-04-20,Giant transition-state enhancement of quasiparticle spin-Hall effect in an exchange-spin-split superconductor detected by non-local magnon spin-transport,"Although recent experiments and theories have shown a variety of exotic
transport properties of non-equilibrium quasiparticles (QPs) in superconductor
(SC)-based devices with either Zeeman or exchange spin-splitting, how QP
interplays with magnon spin currents remains elusive. Here, using non-local
magnon spin-transport devices where a singlet SC (Nb) on top of a ferrimagnetic
insulator (Y3Fe5O12) serves as a magnon spin detector, we demonstrate that the
conversion efficiency of magnon spin to QP charge via inverse spin-Hall effect
(iSHE) in such an exchange-spin-split SC can be greatly enhanced by up to 3
orders of magnitude compared with that in the normal state, particularly when
its interface superconducting gap matches the magnon spin accumulation. Through
systematic measurements with varying the current density and SC thickness, we
identify that superconducting coherence peaks and exchange spin-splitting of
the QP density-of-states, yielding a larger spin excitation while retaining a
modest QP charge-imbalance relaxation, are responsible for the giant QP iSHE.
The latter exchange-field-modified QP relaxation is experimentally proved by
spatially resolved measurements with varying the separation of electrical
contacts on the spin-split Nb.",2004.09467v2
2020-04-30,Unifying femtosecond and picosecond single-pulse magnetic switching in GdFeCo,"Many questions are still open regarding the physical mechanisms behind the
magnetic switching in GdFeCo alloys by single optical pulses. Phenomenological
models suggest a femtosecond scale exchange relaxation between sublattice
magnetization as the driving mechanism for switching. The recent observation of
thermally induced switching in GdFeCo by using both several picosecond optical
laser pulse as well as electric current pulses has questioned this previous
understanding. This has raised the question of whether or not the same
switching mechanics are acting at the femo- and picosecond scales. In this
work, we aim at filling this gap in the understanding of the switching
mechanisms behind thermal single-pulse switching. To that end, we have studied
experimentally thermal single-pulse switching in GdFeCo alloys, for a wide
range of system parameters, such as composition, laser power and pulse
duration. We provide a quantitative description of the switching dynamics using
atomistic spin dynamics methods with excellent agreement between the model and
our experiments across a wide range of parameters and timescales, ranging from
femtoseconds to picoseconds. Furthermore, we find distinct element-specific
damping parameters as a key ingredient for switching with long picosecond
pulses and argue, that switching with pulse durations as long as 15 picoseconds
is possible due to a low damping constant of Gd. Our findings can be easily
extended to speed up dynamics in other contexts where ferrimagnetic GdFeCo
alloys have been already demonstrated to show fast and energy-efficient
processes, e.g. domain-wall motion in a track and spin-orbit torque switching
in spintronics devices.",2004.14844v1
2020-12-17,Magnetic reversal and pinning in a perpendicular zero moment half-metal,"Compensated ferrimagnets are promising materials for fast spintronic
applications based on domain wall motion as they combine the favourable
properties of ferromagnets and antiferromagnets. They inherit from
antiferromagnets immunity to external fields, fast spin dynamics and rapid
domain wall motion. From ferromagnets they inherit straightforward ways to read
out the magnetic state, especially in compensated half metals, where electrons
flow in only one spin channel. Here, we investigate domain structure in
compensated half-metallic Mn2Ru0.5Ga films and assess their potential in domain
wall motion-based spin-electronic devices. Our focus is on understanding and
reducing domain wall pinning in unpatterned epitaxial thin films. Two modes of
magnetic reversal, driven by nucleation or domain wall motion, are identified
for different thin film deposition temperatures $(T_{dep})$. The magnetic
aftereffect is analysed to extract activation volumes $(V^*)$, activation
energies $(E_A)$, and their variation $({\Delta}E_A)$. The latter is decisive
for the magnetic reversal regime, where domain wall motion dominated reversal
(weak pinning) is found for ${\Delta}E_A<0.2$ eV and nucleation dominated
reversal (strong pinning) for ${\Delta}E_A>0.5$ eV. A minimum ${\Delta}E_A=28$
meV is found for $T_{dep}=290{\deg}$C. Prominent pinning sites are visualized
by analysing virgin domain patterns after thermal demagnetization. In the
sample investigated they have spacings of order 300 nm, which gives an upper
limit of the track-width of spin-torque domain-wall motion-based devices.",2012.09515v1
2020-12-20,Magnetic properties and phase diagrams of mixed spin-1 and spin-1/2 Ising model on a checkerboard square structure: A Monte Carlo study,"The magnetic properties and phase diagrams of the mixed spin-1 and spin-1/2
Ising model on a checkerboard square structure have been studied using the
Monte Carlo simulations based on the Metropolis update protocol. The system
consists of four quartets of alternative spin configuration. The effect of the
exchange interactions J and crystal field D on the magnetic properties,
critical and compensation temperatures, susceptibility, and specific heat of
the system have been investigated. The phase diagrams, T-J and T-D, for
different values of the exchange interactions and crystal field have been
examined. We found that the compensation temperature starts to evolve for J1 <
0.6 of the spin-1 assembly and for J2 > 1.6 for spin-1/2. On the other hand,
the effect of ferrimagnetic coupling does not show any threshold value; in this
case, the compensation temperature is constant. Regarding the crystal field
strength, the threshold value of D > -0.8 has been observed. We obtain the N-,
Q- and P-type compensation behaviors in the system. We have observed that the
phase diagrams exhibit only a second-order phase transition to a paramagnetic
phase; hence, the system does not show the tricritical point. The magnetic
hysteresis cycles of the mixed spin-1 and spin-1/2 on a checkerboard square
structure for different values of the exchange interactions, temperatures, and
crystal fields have been found. Finally, the system exhibits the
superparamagnetism behavior for a fixed value of the temperature and crystal
field.",2012.10920v2
2021-01-12,Carrier Density and Thickness Dependent Proximity Effect in Doped Topological Insulator -- Metallic Ferromagnet Bilayers,"We use magneto-conductivity to study the magnetic proximity effect on surface
states of doped topological insulators. Our bilayers consist of a layer of
Fe$_7$Se$_8$, which is a metallic ferrimagnet and a layer of
Bi$_{0.8}$Sb$_{1.2}$Te$_{3}$ which is a highly hole-doped topological
insulator. Using transport measurements and a modified Hikami-Larkin-Nagaoka
model, we show that the ferromagnet shortens significantly the effective
coherence length of the surface states, suggesting that a gap is opened at the
Dirac point. We show that the magnetically induced gap persists on surface
states which are separated from the magnet by a topological insulator layer as
thick as 170 [nm]. Furthermore, the size of the gap is found to be proportional
to the magnetization that we extract from the anomalous Hall effect.
  Our results give information on the ties between carrier density, induced
magnetization and magnetically induced gap in topological insulator/ferromagnet
bilayers. This information is important both for a theoretical understanding of
magnetic interactions in topological insulators and for the practical
fabrication of such bilayers, which are the basis of various suggested
technologies, such as spintronic devices, far infra-red detectors etc.",2101.04536v3
2017-05-05,Thermographic measurements of the spin Peltier effect in metal/yttrium-iron-garnet junction systems,"The spin Peltier effect (SPE), heat-current generation due to spin-current
injection, in various metal (Pt, W, and Au single layers and Pt/Cu
bilayer)/ferrimagnetic insulator (yttrium iron garnet: YIG) junction systems
has been investigated by means of a lock-in thermography (LIT) method. The SPE
is excited by a spin current across the metal/YIG interface, which is generated
by applying a charge current to the metallic layer via the spin Hall effect.
The LIT method enables the thermal imaging of the SPE free from the
Joule-heating contribution. Importantly, we observed spin-current-induced
temperature modulation not only in the Pt/YIG and W/YIG systems but also in the
Au/YIG and Pt/Cu/YIG systems, excluding the possible contamination by anomalous
Ettingshausen effects due to proximity-induced ferromagnetism near the
metal/YIG interface. As demonstrated in our previous study, the SPE signals are
confined only in the vicinity of the metal/YIG interface; we buttress this
conclusion by reducing a spatial blur due to thermal diffusion in an infrared
emission layer on the sample surface used for the LIT measurements. We also
found that the YIG-thickness dependence of the SPE is similar to that of the
spin Seebeck effect measured in the same Pt/YIG sample, implying the reciprocal
relation between them.",1705.02094v1
2017-05-22,Time-of-flight elastic and inelastic neutron scattering studies on the localized $4d$ electron layered perovskite La$_5$Mo$_4$O$_{16}$,"The magnetic structure and spin-wave excitations in the quasi-square-lattice
layered perovskite compound La$_5$Mo$_4$O$_{16}$ were studied by a combination
of neutron diffraction and inelastic neutron scattering techniques using
polycrystalline sample. Neutron powder diffraction refinement revealed that the
magnetic structure is ferrimagnetic in the $ab$ plane with antiferromagnetic
stacking along the $c$ axis where the magnetic propagation vector is
$\mathbf{k}=\left(0,0,\frac{1}{2}\right)$. The ordered magnetic moments are
estimated to be $0.54(2)\mu_\text{B}$ for Mo$^{5+}$ ($4d^1$) ions and
$1.07(3)\mu_\text{B}$ for Mo$^{4+}$ ($4d^2$) ions at 4 K, which are about half
of the expected values. The inelastic neutron scattering results display strong
easy-axis magnetic anisotropy along the $c$ axis due to the spin-orbit
interaction in Mo ions evidenced by the spin gap at the magnetic zone center.
The model Hamiltonian consisting of in-plane anisotropic exchange interactions,
the interlayer exchange interaction, and easy-axis single-ion anisotropy can
explain our inelastic neutron scattering data well. Strong Ising-like
anisotropy and weak interlayer coupling compared with the intralayer exchange
interaction can explain both the high-temperature magnetoresistance and
long-time magnetization decay recently observed in La$_5$Mo$_4$O$_{16}$.",1705.07916v1
2017-05-24,Deficiency of the Bulk Spin Hall Effect Model for Spin-Orbit Torques in Magnetic Insulator/Heavy Metal Heterostructures,"Electrical currents in a magnetic insulator/heavy metal heterostructure can
induce two simultaneous effects, namely, spin Hall magnetoresistance (SMR) on
the heavy metal side and spin-orbit torques (SOTs) on the magnetic insulator
side. Within the framework of the pure spin current model based on the bulk
spin Hall effect (SHE), the ratio of the spin Hall-induced anomalous Hall
effect (SH-AHE) to SMR should be equal to the ratio of the field-like torque
(FLT) to damping-like torque (DLT). We perform a quantitative study of SMR,
SH-AHE, and SOTs in a series of thulium iron garnet/platinum or Tm3Fe5O12/Pt
heterostructures with different Tm3Fe5O12 thicknesses, where Tm3Fe5O12 is a
ferrimagnetic insulator with perpendicular magnetic anisotropy. We find the
ratio between measured effective fields of FLT and DLT is at least 2 times
larger than the ratio of the SH-AHE to SMR. In addition, the bulk SHE model
grossly underestimates the spin torque efficiency of FLT. Our results reveal
deficiencies of the bulk SHE model and also address the importance of
interfacial effects such as the Rashba and magnetic proximity effects in
magnetic insulator/heavy metal heterostructures.",1705.08919v1
2017-09-13,Spin Hall magnetoresistance in antiferromagnet/heavy-metal heterostructures,"We investigate the spin Hall magnetoresistance in thin film bilayer
heterostructures of the heavy metal Pt and the antiferromagnetic insulator NiO.
While rotating an external magnetic field in the easy plane of NiO, we record
the longitudinal and the transverse resistivity of the Pt layer and observe an
amplitude modulation consistent with the spin Hall magnetoresistance. In
comparison to Pt on collinear ferrimagnets, the modulation is phase shifted by
90{\deg} and its amplitude strongly increases with the magnitude of the
magnetic field. We explain the observed magnetic field-dependence of the spin
Hall magnetoresistance in a comprehensive model taking into account magnetic
field induced modifications of the domain structure in antiferromagnets. With
this generic model we are further able to estimate the strength of the
magnetoelastic coupling in antiferromagnets. Our detailed study shows that the
spin Hall magnetoresistance is a versatile tool to investigate the magnetic
spin structure as well as magnetoelastic effects, even in antiferromagnetic
multidomain materials.",1709.04158v2
2017-09-18,Magnetic field driven enhanced ferroelectric switching in self-grown ferroelectric-ferromagnetic composite in the BiFeO3-BaTiO3 multiferroic alloy system,"Over the years attempts have been made to compensate for the inherent
weaknesses in the bulk state of the multiferroic BiFeO3, such as high leakage
current and the absence of ferromagnetic correlation, and exploit its
magnetoelectric potential by forming solid solutions with other perovskites.
Studies in the recent few years have shown that alloying of BiFeO3 with BaTiO3,
both with and without additives, can induce both ferroelectric and
ferromagnetic switching. While the coexistence of both the ferroic orders is
encouraging from the view point of technological applications, the origin of
ferromagnetism in this system remains elusive. Here, we synthesized such
compositions and carried out a detailed structural analysis employing magnetic
separation of the powder particles. We found that the origin of ferromagnetism
lies in the spontaneous precipitation of a minor ( ~ 1 wt %) barium hexaferrite
(BaFe9O19) phase, often undetected in routine x-ray diffraction studies of
powders sampled from the entire specimen. We also demonstrate that inspite of
the insignificant fraction the ferrimagnetic phase, this self-grown composite
exhibit noticeably enhanced ferroelectric switching in the presence of external
magnetic field. We obtained a dc magnetoelectric coupling of ~ 9 x 10-8 s/m, a
value which is comparable to what has been reported for layered
ferroelectric/ferromagnetic laminates and bilayer thin film
ferroelectric-ferromagnetic hetrostructures. Our study suggests that reasonably
large magnetoelectric coupling is realizable in simple 0-3
ferroelectric-ferromagnetic bulk composites provided synthesis strategies are
developed which induces spontaneous precipitation of the ferromagnetic phase in
small volume fraction to ensure good insulating behaviour of the composite thus
developed.",1709.05898v1
2018-03-21,Probing Landau levels of strongly interacting massive Dirac electrons in layer-polarized MoS$_2$,"Monolayer transition metal dichalcogenides are recently emerged 2D electronic
systems with various novel properties, such as spin-valley locking, circular
dichroism, valley Hall effects, Ising superconductivity. The reduced
dimensionality and large effective masses further produce unconventional
many-body interaction effects. Although recent hole transport measurements in
WSe$_2$ indicate strong interactions in the valence bands, many-body
interaction effects, particularly in the conduction bands, remain elusive to
date. Here, for the first time, we perform transport measurements up to a
magnetic field of $29$T to study the massive Dirac electron Landau levels (LL)
in layer-polarized MoS$_2$ samples with mobilities of $22000$cm$^2$/(V$\cdot$s)
at $1.5$K and densities of $\sim10^{12}$cm$^{-2}$. With decreasing the density,
we observe LL crossing induced valley ferrimagnet-to-ferromagnet transitions,
as a result of the interaction enhancement of the g-factor from $5.64$ to
$21.82$. Near integer ratios of Zeeman-to-cyclotron energies, we discover LL
anticrossings due to the formation of quantum Hall Ising ferromagnets, the
valley polarizations of which appear to be reversible by tuning the density or
an in-plane magnetic field. Our results provide compelling evidence for
many-body interaction effects in the conduction bands of monolayer MoS$_2$ and
establish a fertile ground for exploring strongly correlated phenomena of
massive Dirac electrons.",1803.08007v1
2018-07-18,"Magnetic Properties of the low dimensional BaM$_2$Si$_2$O$_7$(M= Cu, Co, Mn) system","We performed susceptibility, magnetization, specific heat, and single crystal
neutron diffraction measurements on single crystalline BaMn$_2$Si$_2$O$_7$.
Based on the results, we revisited its spin structure with a more accurate
solution and constructed a magnetic phase diagram with applied field along the
$b$-axis, which contains a spin flop transition around 6 T. We also used
susceptibility, magnetization, and specific heat results confirmed the
ferrimagnetic-like magnetism in polycrystalline BaCo$_2$Si$_2$O$_7$.
Furthermore, we performed LSDA + U calculations for the BaM$_2$Si$_2$O$_7$ (M =
Cu, Co, and Mn) system. Our discussions based on the comparison among the
obtained magnetic exchange interactions suggest the different structures and
electronic configurations are the reasons for the different magnetic properties
among the system members.",1807.06883v1
2018-12-07,"Ab-initio approach to the stability and the structural, electronic and magnetic properties of the (001) Znfe2O4 surface terminations","We present a Density Functional Theory (DFT) based study of the structural
and magnetic properties of the (001) surface of the semiconducting oxide
ZnFe2O4 (spinel structure). The calculations were performed using the DFT based
ab initio plane wave and pseudopotential method as implemented in the Quantum
Espresso code. The all electron Full-potential linearized-augmented-plane-wave
method (FP-LAPW) was also employed to check the accuracy of plane wave method.
In both calculations the DFT+U methodology was employed and different (001)
surface terminations of ZnFe2O4 were studied: We find that the surface
terminated in Zn is the stable one. For all the (001) surface terminations our
calculations predict that the Zn-Fe cationic inversion (antisites), which are
defects in bulk ZnFe2O4, becomes stable and an integral part of the surface.
Also, a ferrimagnetic behavior is predicted for the case of antisites in the
superficial layer. Our results for different properties of the surface of
ZnFe2O4 are compared with those obtained in bulk samples and those reported in
the literature.",1812.03129v2
2018-12-31,Systematic Control of Strain-Induced Perpendicular Magnetic Anisotropy in Epitaxial Europium and Terbium Iron Garnets Thin Films,"We show tunable strain-induced perpendicular magnetic anisotropy (PMA) over a
wide range of thicknesses in epitaxial ferrimagnetic insulator Eu3Fe5O12 (EuIG)
and Tb3Fe5O12 (TbIG) thin films grown by pulsed-laser deposition on Gd3Ga5O12
with (001) and (111) orientations, respectively. The PMA field is determined by
measuring the induced anomalous Hall loops in Pt deposited on the garnet films.
Due to positive magnetostriction constants, compressive in-plane strain induces
a PMA field as large as 32.9 kOe for 4 nm thick EuIG and 66.7 kOe for 5 nm
thick TbIG at 300 K, and relaxes extremely slowly as the garnet film thickness
increases. In bilayers consisting of Pt and EuIG or Pt and TbIG, robust PMA is
revealed by squared anomalous Hall hysteresis loops in Pt, the magnitude of
which appears to be only related to the net magnetic moment of iron
sublattices. Furthermore, the magnetostriction constant is found to be
2.7x10^(-5) for EuIG and 1.35x10^(-5) for TbIG, comparable with the values for
bulk crystals. Our results demonstrate a general approach of tailoring magnetic
anisotropy of rare earth iron garnets by utilizing modulated strain via
epitaxial growth.",1812.11688v1
2019-01-15,Anomalous Hall Conductivity of a Non-Collinear Magnetic Antiperovskite,"The anomalous Hall effect (AHE) is a well-known fundamental property of
ferromagnetic metals, commonly associated with the presence of a net
magnetization. Recently, an AHE has been discovered in non-collinear
antiferromagnetic (AFM) metals. Driven by non-vanishing Berry curvature of AFM
materials with certain magnetic space group symmetry, anomalous Hall
conductivity (AHC) is very sensitive to the specific type of magnetic ordering.
Here, we investigate the appearance of AHC in antiperovskite GaNMn$_{3}$ as a
representative of broader materials family ANMn$_{3}$ (A is a main group
element), where different types of non-collinear magnetic ordering can emerge.
Using symmetry analyses and first-principles density-functional theory
calculations, we show that with almost identical band structure, the nearly
degenerate non-collinear AFM $\Gamma_{5g}$ and $\Gamma_{4g}$ phases of
GaNMn$_{3}$ have zero and finite AHC, respectively. In a non-collinear
ferrimagnetic $M$-1 phase, GaNMn$_{3}$ exhibits a large AHC due to the presence
of a sizable net magnetic moment. In the non-collinear antiperovskite magnets,
transitions between different magnetic phases, exhibiting different AHC states,
can be produced by doping, strain, or spin transfer torque, which makes these
materials promising for novel spintronic applications.",1901.05040v1
2019-02-14,High-speed domain wall racetracks in a magnetic insulator,"Recent reports of current-induced switching of ferrimagnetic oxides coupled
to a heavy metal layer have opened realistic prospects for implementing
magnetic insulators into electrically addressable spintronic devices. However,
key aspects such as the configuration and dynamics of magnetic domain walls
driven by electrical currents in insulating oxides remain unexplored. Here, we
investigate the internal structure of the domain walls in Tm3Fe5O12 (TmIG) and
TmIG/Pt bilayers and demonstrate their efficient manipulation by spin-orbit
torques with velocities of up to 400 m s$^{-1}$ and minimal current threshold
for domain wall flow of 5 x 10$^{6}$ A cm$^{-2}$. Domain wall racetracks
embedded in TmIG are defined by the deposition of Pt current lines, which allow
us to control the domain propagation and magnetization switching in selected
regions of an extended magnetic layer. Scanning nitrogen-vacancy magnetometry
reveals that the domain walls of thin TmIG films are N\'eel walls with
left-handed chirality, with the domain wall magnetization rotating towards an
intermediate N\'eel-Bloch configuration upon deposition of Pt. These results
indicate the presence of a sizable interfacial Dzyaloshinskii-Moriya
interaction in TmIG, which leads to novel possibilities to control the
formation of chiral spin textures in magnetic insulators. Ultimately, domain
wall racetracks provide an efficient scheme to pattern the magnetic landscape
of TmIG in a fast and reversible way",1902.05639v1
2019-03-01,Highly efficient spin-orbit torque and switching of layered ferromagnet Fe3GeTe2,"Among van der Waals (vdW) layered ferromagnets, Fe3GeTe2 (FGT) is an
excellent candidate material to form FGT/heavy metal heterostructures for
studying the effect of spin-orbit torques (SOT). Its metallicity, strong
perpendicular magnetic anisotropy built in the single atomic layers, relatively
high Curie temperature (Tc about 225 K) and electrostatic gate tunability offer
a tantalizing possibility of achieving the ultimate high SOT limit in monolayer
all-vdW nanodevices. The spin current generated in Pt exerts a damping-like SOT
on FGT magnetization. At about 2.5x1011 A/m2 current density,SOT causes the FGT
magnetization to switch, which is detected by the anomalous Hall effect of FGT.
To quantify the SOT effect, we measure the second harmonic Hall responses as
the applied magnetic field rotates the FGT magnetization in the plane. Our
analysis shows that the SOT efficiency is comparable with that of the best
heterostructures containing three-dimensional (3D) ferromagnetic metals and
much larger than that of heterostructures containing 3D ferrimagnetic
insulators. Such large efficiency is attributed to the atomically flat FGT/Pt
interface, which demonstrates the great potential of exploiting vdW
heterostructures for highly efficient spintronic nanodevices.",1903.00571v1
2019-03-03,RKKY Interactions in Graphene Landau Levels,"We study RKKY interactions for magnetic impurities on graphene in situations
where the electronic spectrum is in the form of Landau levels. Two such
situations are considered: non-uniformly strained graphene, and graphene in a
real magnetic field. RKKY interactions are enhanced by the lowest Landau level,
which is shown to form electron states binding with the spin impurities and add
a strong non-perturbative contribution to pairwise impurity spin interactions
when their separation $R$ no more than the magnetic length. Beyond this
interactions are found to fall off as $1/R^3$ due to perturbative effects of
the negative energy Landau levels. Based on these results, we develop simple
mean-field theories for both systems, taking into account the fact that
typically the density of states in the lowest Landau level is much smaller than
the density of spin impurities. For the strain field case, we find that the
system is formally ferrimagnetic, but with very small net moment due to the
relatively low density of impurities binding electrons. The transition
temperature is nevertheless enhanced by them. For real fields, the system forms
a canted antiferromagnet if the field is not so strong as to pin the impurity
spins along the field. The possibility that the system in this latter case
supports a Kosterlitz-Thouless transition is discussed.",1903.00980v1
2019-03-21,Competition between exchange-driven dimerization and magnetism in diamond(111),"Strong electron-electron interaction in ultraflat edge states can be
responsible for correlated phases of matter, such as magnetism, charge density
wave or superconductivity. Here we consider the diamond(111) surface that,
after Pandey reconstruction, presents zig-zag carbon chains, generating a flat
surface band. By performing full structural optimization with hybrid
functionals and neglecting spin polarization, we find that a substantial
dimerization ($0.090$ {\AA} / $0.076$ {\AA} bond disproportionation in the
PBE0/HSE06) occurs on the chains; a structural effect absent in calculations
based on the LDA/GGA functionals. This dimerization is the primary mechanism
for the opening of an insulating gap in the absence of spin polarization. The
single-particle direct gap is $1.7$ eV ($1.0$ eV) in the PBE0 (HSE06),
comparable with the experimental optical gap of $1.47$ eV, and on the
larger(smaller) side of the estimated experimental single particle gap window
of 1.57-1.87 eV, after inclusion of excitonic effects. However, by including
spin polarization in the calculation, we find that the exchange interaction
stabilizes a different ground state, undimerized, with no net magnetization and
ferrimagnetic along the Pandey $\pi$-chains with magnetic moments as large as
$0.2-0.3~\mu_B$ in the PBE0. The direct single-particle band gap in the equal
spin-channel is approximately $2.2$ eV ($1.5$ eV) with the PBE0 (HSE06)
functional. Our work is relevant for systems with flat bands in general and
wherever the interplay between structural, electronic and magnetic degrees of
freedom is crucial, as in twisted bilayer graphene, IVB atoms on IVB(111)
surfaces such as Pb/Si(111) or molecular crystals.",1903.09226v1
2019-03-27,Structural and magnetic properties of GdCo$_{5-x}$Ni$_x$,"GdCo$_5$ may be considered as two sublattices - one of Gd and one of Co -
whose magnetizations are in antiparallel alignment, forming a ferrimagnet.
Substitution of nickel in the cobalt sublattice of GdCo$_5$ has been
investigated to gain insight into how the magnetic properties of this prototype
rare-earth/transition-metal magnet are affected by changes in the transition
metal sublattice. Polycrystalline samples of GdCo$_{5-x}$Ni$_x$ for 0 $ \leq x
\leq $ 5 were synthesized by arc melting. Structural characterization was
carried out by powder x-ray diffraction and optical and scanning electron
microscope imaging of metallographic slides, the latter revealing a low
concentration of Gd$_2$(Co, Ni)$_7$ lamellae for $x \leq 2.5$. Compensation -
i.e. the cancellation of the opposing Gd and transition metal moments is
observed for $1 \leq x \leq 3$ at a temperature which increases with Ni
content; for larger $x$, no compensation is observed below 360 K. A peak in the
coercivity is seen at $x \approx 1$ at 10K coinciding with a minimum in the
saturation magnetization. Density-functional theory calculations within the
disordered local moment picture reproduce the dependence of the magnetization
on Ni content and temperature. The calculations also show a peak in the
magnetocrystalline anisotropy at similar Ni concentrations to the
experimentally observed coercivity maximum.",1903.11442v1
2019-04-03,Study of the Effect of Annealing on the Properties of Mn2RuxGa Thin Films,"The effect of vacuum annealing thin films of the compensated ferrimagnetic
half-metal Mn2RuxGa at temperatures from 250 to 400 degree Celsius is
investigated. The 39.3 nm films deposited on (100) MgO substrates exhibit
perpendicular magnetic anisotropy due to a small 1% tetragonal elongation
induced by substrate strain. The main change on annealing is a modification in
the compensation temperature, which first increases from 50 K for the
as-deposited film to 185 K after annealing at 250 degree Celsius, and then
falls to 140 K after annealing at 400 degree Celsius. There are minor changes
in the atomic order, coercivity, resistivity and anomalous Hall effect (AHE),
but the net magnetization measured by SQUID magnetometry with the field applied
in-plane or perpendicular-to-the-plane changes more significantly. It saturates
at 20 to 30 kA/m at room temperature, and a small soft component is seen in the
perpendicular SQUID loops which is absent in the square AHE hysteresis loops.
This is explained by the half-metallic nature of the compound; the AHE probes
only the 4c Mn sublattice that provides the spin-polarized electrons at the
Fermi level, whereas the SQUID measures the sum of the oppositely-aligned 4c
and 4a sublattice magnetisations.",1904.01993v1
2019-04-05,"Cluster-based Haldane phases, bound magnon crystals and quantum spin liquids of a mixed spin-1 and spin-1/2 Heisenberg octahedral chain","The mixed spin-1 and spin-1/2 Heisenberg octahedral chain with regularly
alternating monomeric spin-1 sites and square-plaquette spin-1/2 sites is
investigated using variational technique, localized-magnon approach, exact
diagonalization (ED) and density-matrix renormalization group (DMRG) method.
The investigated model has in a magnetic field an extraordinarily rich
ground-state phase diagram, which includes the uniform and cluster-based
Haldane phases, two ferrimagnetic phases of Lieb-Mattis type, two quantum spin
liquids and two bound magnon crystals in addition to the fully polarized
ferromagnetic phase. The lowest-energy eigenstates in a highly-frustrated
parameter region belong to flat bands and hence, low-temperature thermodynamics
above the bound magnon-crystal ground states can be satisfactorily described
within the localized-magnon approach. The variational method provides an exact
evidence for the magnon-crystal phase with a character of the monomer-tetramer
ground state at zero field, while another magnon-crystal phase with a single
bound magnon at each square plaquette is found in a high-field region. A
diversity of quantum ground states gives rise to manifold zero-temperature
magnetization curves, which may involve up to four wide intermediate plateaus
at zero, one-sixth, one-third and two-thirds of the saturation magnetization,
two quantum spin-liquid regions and two tiny plateaus at one-ninth and
one-twelfth of the saturation magnetization corresponding to the fragmentized
cluster-based Haldane phases.",1904.02889v2
2019-08-13,Self-Assembled Room Temperature Multiferroic BiFeO3-LiFe5O8 Nanocomposites,"Multiferroic materials have driven significant research interest due to their
promising technological potential. Developing new room-temperature
multiferroics and understanding their fundamental properties are important to
reveal unanticipated physical phenomena and potential applications. Here, a new
room temperature multiferroic nanocomposite comprised of an ordered
ferrimagnetic spinel LiFe5O8 (LFO) and a ferroelectric perovskite BiFeO3 (BFO)
is presented. We observed that lithium (Li)-doping in BFO favors the formation
of LFO spinel as a secondary phase during the synthesis of LixBi1-xFeO3
nanoceramics. Multimodal functional and chemical imaging methods are used to
map the relationship between doping-induced phase separation and local ferroic
properties in both the BFO-LFO composite ceramics and self-assembled
nanocomposite thin films. The energetics of phase separation in Li doped BFO
and the formation of BFO-LFO composites is supported by first principles
calculations. These findings shed light on Li-ion role in the formation of a
functionally important room temperature multiferroic and open a new approach in
the synthesis of light element doped nanocomposites.",1908.04825v1
2019-08-15,Breakdown of intermediate one-half magnetization plateau of spin-1/2 Ising-Heisenberg and Heisenberg branched chains at triple and Kosterlitz-Thouless critical points,"The spin-1/2 Ising-Heisenberg branched chain composed of regularly
alternating Ising spins and Heisenberg dimers involving an additional side
branching is rigorously solved in a magnetic field by the transfer-matrix
approach. The ground-state phase diagram, the magnetization process and the
concurrence measuring a degree of bipartite entanglement within the Heisenberg
dimers are examined in detail. Three different ground states were found
depending on a mutual interplay between the magnetic field and two different
coupling constants: the modulated quantum antiferromagnetic phase, the quantum
ferrimagnetic phase and the classical ferromagnetic phase. Two former quantum
ground states are manifested in zero-temperature magnetization curves as
intermediate plateaus at zero and one-half of the saturation magnetization,
whereas the one-half plateau disappears at a triple point induced by a strong
enough ferromagnetic Ising coupling. The ground-state phase diagram and
zero-temperature magnetization curves of the analogous spin-1/2 Heisenberg
branched chain were investigated using DMRG calculations. The latter fully
quantum Heisenberg model involves, besides two gapful phases manifested as zero
and one-half magnetization plateaus, gapless quantum spin-liquid phase. The
intermediate one-half plateau of the spin-1/2 Heisenberg branched chain
vanishes at Kosterlitz-Thouless quantum critical point between gapful and
gapless quantum ground states unlike the triple point of the spin-1/2
Ising-Heisenberg branched chain.",1908.05639v1
2019-08-26,Unconventional Ferroelectric Switching via Local Domain Wall Motion in Multiferroic $ε$-Fe2O3 Films,"Deterministic polarization reversal in ferroelectric and multiferroic films
is critical for their exploitation in nanoelectronic devices. While
ferroelectricity has been studied for nearly a century, major discrepancies in
the reported values of coercive fields and saturation polarization persist in
literature for many materials. This raises questions about the atomic-scale
mechanisms behind polarization reversal. Unconventional ferroelectric switching
in $\epsilon$-Fe2O3 films, a material that combines ferrimagnetism and
ferroelectricity at room temperature, is reported here. High-resolution in-situ
scanning transmission electron microscopy (STEM) experiments and
first-principles calculations demonstrate that polarization reversal in
$\epsilon$-Fe2O3 occurs around pre-existing domain walls only, triggering local
domain wall motion in moderate electric fields of 250 - 500 kV/cm. Calculations
indicate that the activation barrier for switching at domain walls is nearly a
quarter of that corresponding to the most likely transition paths inside
$\epsilon$-Fe2O3 domains. Moreover, domain walls provide symmetry lowering,
which is shown to be necessary for ferroelectric switching. Local polarization
reversal in $\epsilon$-Fe2O3 limits the macroscopic ferroelectric response and
offers important hints on how to tailor ferroelectric properties by domain
structure design in other relevant ferroelectric materials.",1908.09691v1
2019-11-01,Role of spin mixing conductance in determining thermal spin pumping near the ferromagnetic phase transition in EuO_{1-x} and La2NiMnO6,"We present a comprehensive study of the temperature (T) dependence of the
longitudinal spin Seebeck effect (LSSE) in Pt/EuO_{1-x} and Pt/La2NiMnO6 (LNMO)
hybrid structures across their Curie temperatures (Tc). Both systems host
ferromagnetic interaction below Tc, hence present optimal conditions for
testing magnon spin current based theories against ferrimagnetic YIG. Notably,
we observe an anomalous Nernst effect (ANE) generated voltage in bare
EuO_{1-x}, however, we find LSSE predominates the thermal signals in the
bilayers with Pt. The T-dependence of the LSSE in small T-range near Tc could
be fitted to a power law of the form (Tc-T)^P. The derived critical exponent,
P, was verified for different methods of LSSE representation and sample
crystallinity. The results are explained based on the magnon-driven thermal
spin pumping mechanism that relate the T-dependence of LSSE to the spin mixing
conductance (Gmix) at the heavy metal/ferromagnet (HM/FM) interface, which in
turn is known to vary in accordance with the square of the spontaneous
magnetization (Ms). Additionally, the T-dependence of the real part of Gmix
derived from spin Hall magnetoresistance measurements at different temperatures
for the Pt/LNMO structure, further establish the interdependence.",1911.00211v1
2019-11-18,Experimental observation of Josephson oscillations in a room-temperature Bose-Einstein magnon condensate,"The alternating current (ac) Josephson effect in a time-independent
spatially-inhomogeneous setting is manifested by the occurrence of Josephson
oscillations - periodic macroscopic phase-induced collective motions of the
quantum condensate. So far, this phenomenon was observed at cryogenic
temperatures in superconductors, in superfluid helium, and in Bose-Einstein
condensates (BECs) of trapped atoms. Here, we report on the discovery of the ac
Josephson effect in a magnon BEC carried by a room-temperature ferrimagnetic
film. The BEC is formed in a parametrically populated magnon gas in the spatial
vicinity of a magnetic trench created by a dc electric current. The appearance
of the Josephson effect is manifested by oscillations of the magnon BEC density
in the trench, caused by a coherent phase shift between this BEC and the BEC in
the nearby regions. Our findings advance the physics of room-temperature
macroscopic quantum phenomena and will allow for their application for data
processing in magnon spintronics devices.",1911.07802v3
2019-12-04,Compensated magnetic insulators for extremely fast spin-orbitronics,"The fast spin dynamics provide many opportunities for the future
communication and memory technologies. One of the most promising examples is
the domain wall (DW) racetrack memory. To achieve fast device performances, the
high-speed motion of DWs is naturally demanded that leaves antiferromagnets
(AFMs) and compensated ferrimagnets (FIMs) as the promising materials. While
controlling and probing the dynamics of DWs in AFMs remains challenging, the
fast motion of DWs with velocities around 1500 m/s has been demonstrated in
metallic FIMs. The velocity of DWs in metallic FIMs is, however, suppressed by
the magnetic damping of conduction electrons, which motivates us to explore how
fast DWs can move in insulating FIMs where the conduction electron is absent.
In this work, through synthesizing compensated FIM insulator Gd3Fe5O12 thin
films with a perpendicular magnetic anisotropy, we demonstrate that the
spin-orbit torque (SOT) induced motion of DWs along the Gd3Fe5O12/Pt racetrack
can approach 6000 m/s. Our results show that the exceptionally fast motion of
DWs can be achieved in compensated FIM insulators owing to small damping
inherent to magnetic insulators, which could potentially facilitate the
emerging ultrahigh-speed spintronic logics and racetrack memories by
introducing insulating compensated FIMs as a new material platform.",1912.01775v1
2019-12-31,Noncoplanar ferrimagnetism and local crystalline-electric-field anisotropy in the quasicrystal approximant Au$_{70}$Si$_{17}$Tb$_{13}$,"Neutron scattering experiments have been performed to elucidate magnetic
properties of the quasicrystal approximant Au$_{70}$Si$_{17}$Tb$_{13}$,
consisting of icosahedral spin clusters in a body-centered-cubic lattice. Bulk
magnetic measurements performed on the single crystalline sample unambiguously
confirm long-range ordering at $T_{\rm C} = 11.6 \pm 1$ K. In contrast to the
simple ferromagnetic response in the bulk measurements, single crystal neutron
diffraction confirms a formation of intriguing non-collinear and non-coplanar
magnetic order. The magnetic moment direction was found to be nearly tangential
to the icosahedral cluster surface in the local mirror plane, which is quite
similar to that recently found in the antiferromagnetic quasicrystal
approximant Au$_{72}$Al$_{14}$Tb$_{14}$. Inelastic neutron scattering on the
powdered sample exhibits a very broad peak centered at $\hbar \omega \simeq 4$
meV. The observed inelastic spectrum was explained by the
crystalline-electric-field model taking account of the chemical disorder at the
fractional Au/Si sites. The resulting averaged anisotropy axis for the
crystalline-electric-field ground state is consistent with the ordered moment
direction determined in the magnetic structure analysis, confirming that the
non-coplanar magnetic order is stabilized by the local uniaxial anisotropy.",1912.13180v1
2020-03-09,Predicted strong coupling of solid-state spins via a single magnon mode,"We propose an approach to realize a hybrid quantum system composed of a
diamond nitrogen-vacancy (NV) center spin coupled to a magnon mode of the
low-damping, low-moment organic ferrimagnet vanadium tetracyanoethylene. We
derive an analytical expression for the spin-magnon cooperativity as a function
of NV position under a micron-scale perpendicularly magnetized disk, and show
that, surprisingly, the cooperativity will be higher using this magnetic
material than in more conventional materials with larger magnetic moments, due
to in part to the reduced demagnetization field. For reasonable experimental
parameters, we predict that the spin-magnon-mode coupling strength is $g\sim
10$ kHz. For isotopically pure $^{12}$C diamond we predict strong coupling of
an NV spin to the unoccupied magnon mode, with cooperativity $\mathcal C=6$ for
a wide range of NV spin locations within the diamond, well within the spatial
precision of NV center implantation. Thus our proposal describes a practical
pathway for single-spin-state-to-single-magnon-occupancy transduction and for
entangling NV centers over micron length scales.",2003.04341v2
2020-03-11,Correlations in the elastic Landau level of spontaneously buckled graphene,"Electronic correlations stemming from nearly flat bands in van der Waals
materials have demonstrated to be a powerful playground to engineer artificial
quantum matter, including superconductors, correlated insulators and
topological matter. This phenomenology has been experimentally observed in a
variety of twisted van der Waals materials, such as graphene and dichalcogenide
multilayers. Here we show that spontaneously buckled graphene can yield a
correlated state, emerging from an elastic pseudo Landau level. Our results
build on top of recent experimental findings reporting that, when placed on top
of hBN or NbSe$_2$ substrates, wrinkled graphene sheets relax forming a
periodic, long-range buckling pattern. The low-energy physics can be accurately
described by electrons in the presence of a pseudo-axial gauge field, leading
to the formation of sublattice-polarized Landau levels. Moreover, we verify
that the high density of states at the zeroth Landau level leads to the
formation of a periodically modulated ferrimagnetic groundstate, which can be
controlled by the application of external electric fields. Our results indicate
that periodically strained graphene is a versatile platform to explore emergent
electronic states arising from correlated elastic Landau levels.",2003.05163v4
2020-05-18,"Effects of filling, strain, and electric field on the Néel vector in antiferromagnetic CrSb","CrSb is a layered antiferromagnet (AFM) with perpendicular magnetic
anisotropy, a high N\'{e}el temperature, and large spin-orbit coupling (SOC),
which makes it interesting for AFM spintronic applications. To elucidate the
various mechanisms of N\'{e}el vector control, the effects of strain, band
filling, and electric field on the magnetic anisotropy energy (MAE) of bulk and
thin-film CrSb are determined and analysed using density functional theory. The
MAE of the bulk crystal is large (1.2 meV per unit cell). Due to the
significant ionic nature of the Cr-Sb bond, finite slabs are strongly affected
by end termination. Truncation of the bulk crystal to a thin film with one
surface terminated with Cr and the other surface terminated with Sb breaks
inversion symmetry, creates a large charge dipole and average electric field
across the film, and breaks spin degeneracy, such that the thin film becomes a
ferrimagnet. The MAE is reduced such that its sign can be switched with
realistic strain, and the large SOC gives rise to an intrinsic voltage
controlled magnetic anisotropy (VCMA). A slab terminated on both faces with Cr
remains a compensated AFM, but with the compensation occurring nonlocally
between mirror symmetric Cr pairs. In-plane alignment of the moments is
preferred, the magnitude of the MAE remains large, similar to that of the bulk,
and it is relatively insensitive to filling.",2005.08412v5
2020-05-23,Enhanced entanglement and asymmetric EPR steering between magnons,"The generation and manipulation of strong entanglement and
Einstein-Podolsky-Rosen (EPR) steering in macroscopic systems are outstanding
challenges in modern physics. Especially, the observation of asymmetric EPR
steering is important for both its fundamental role in interpreting the nature
of quantum mechanics and its application as resource for the tasks where the
levels of trust at different parties are highly asymmetric. Here, we study the
entanglement and EPR steering between two macroscopic magnons in a hybrid
ferrimagnet-light system. In the absence of light, the two types of magnons on
the two sublattices can be entangled, but no quantum steering occurs when they
are damped with the same rates. In the presence of the cavity field, the
entanglement can be significantly enhanced, and strong two-way asymmetric
quantum steering appears between two magnons with equal dispassion. This is
very different from the conventional protocols to produce asymmetric steering
by imposing additional unbalanced losses or noises on the two parties at the
cost of reducing steerability. The essential physics is well understood by the
unbalanced population of acoustic and optical magnons under the cooling effect
of cavity photons. Our finding may provide a novel platform to manipulate the
quantum steering and the detection of bi-party steering provides a knob to
probe the magnetic damping on each sublattice of a magnet.",2005.11471v1
2020-05-27,Thermodynamic behaviour of magnetocaloric quantities in spin-1/2 Ising square trilayer,"A spin-1/2, Ising trilayered ferrimagnetic system on square Bravais lattice
is studied, employing Monte-Carlo simulation with the single spin-flip
Metropolis algorithm. The bulk of such a system is formed by three layers, each
of which is composed entirely either by A or B type of atoms, resulting in two
distinct compositions: ABA and AAB and two different types of magnetic
interactions: ferromagnetic between like atoms and antiferromagnetic between
unlike atoms. For such systems, Inverse Absolute of Reduced Residual
Magnetisation is the absolute value of the ratio of the extremum of the
magnetisation in between compensation and critical points and the saturation
magnetisation. Variation of relative interaction strengths in the Hamiltonian,
for a range of values, leads to the shift of compensation point and critical
point and changes in the magnitude of Inverse absolute of Reduced Residual
magnetisation. Probable mathematical forms of dependences of the Inverse
absolute of Reduced Residual magnetisation and temperature interval between the
compensation and critical points on controlling parameters were proposed in the
absence of applied magnetic field and have obtained phase diagrams for both
types of configurations from these relations. This alternative description of
the simulated systems may help technologists design magnetocaloric materials
according to desired characteristics.",2005.13509v6
2020-08-08,Tuning interchain ferromagnetic instability in A2Cr3As3 ternary arsenides by chemical pressure and uniaxial strain,"We analyze the effects of chemical pressure induced by alkali metal
substitution and uniaxial strain on magnetism in the A2Cr3As3 (A = Na, K, Rb,
Cs) family of ternary arsenides with quasi-one dimensional structure. Within
the framework of the density functional theory, we predict that the
non-magnetic phase is very close to a 3D collinear ferrimagnetic state, which
realizes in the regime of moderate correlations, such tendency being common to
all the members of the family with very small variations due to the different
interchain ferromagnetic coupling. We uncover that the stability of such
interchain ferromagnetic coupling has a non-monotonic behavior with increasing
the cation size, being critically related to the degree of structural
distortions which is parametrized by the Cr-As-Cr bonding angles along the
chain direction. In particular, we demonstrate that it is boosted in the case
of the Rb, in agreement with recent experiments. We also show that uniaxial
strain is a viable tool to tune the non-magnetic phase towards an interchain
ferromagnetic instability. The modifcation of the shape of the Cr triangles
within the unit cell favors the formation of a net magnetization within the
chain and of a ferromagnetic coupling among the chains. This study can provide
relevant insights about the interplay between superconductivity and magnetism
in this class of materials.",2008.03552v4
2020-08-20,Tuning the magnetism and band topology through antisite defects in Sb doped MnBi4Te7,"The fine control of magnetism and electronic structure is crucial since the
interplay between magnetism and band topology can lead to various novel
magnetic topological states including axion insulators, magnetic Weyl
semimetals and Chern insulators etc. Through crystal growth, transport,
thermodynamic, neutron diffraction measurements, we show that with Sb-doping,
the newly-discovered intrinsic antiferromagnetic topological insulator MnBi4Te7
evolves from antiferro-magnetic to ferromagnetic and then ferrimagnetic. We
attribute this to the formation of Mn(Bi,Sb) antisites upon doping, which
result in additional Mn sublattices that modify the delicate interlayer
magnetic interactions and cause the dominant Mn sublattice to go from
antiferromagnetic to ferro-magnetic. We further investigate the effect of
antisites on the band topology using the first-principles calculations. Without
considering antisites, the series evolves from antiferromagnetic topological
insulator (x = 0) to ferromagnetic axion insulators. In the exaggerated case of
16.7% of periodic antisites, the band topology is modified and type-I magnetic
Weyl semimetal phase can be realized at intermediate dopings. Therefore, this
doping series provides a fruitful platform with continuously tunable magnetism
and topology for investigating emergent phenomena, including quantum anomalous
Hall effect, Fermi arc states, etc.",2008.09097v4
2020-09-14,Effective field theory of magnon: Dynamics in chiral magnets and Schwinger mechanism,"We develop the effective field theoretical descriptions of spin systems in
the presence of symmetry-breaking effects: the magnetic field, single-ion
anisotropy, and Dzyaloshinskii-Moriya interaction. Starting from the lattice
description of spin systems, we show that the symmetry-breaking terms
corresponding to the above effects can be incorporated into the effective field
theory as a combination of a background (or spurious) $\SO(3)$ gauge field and
a scalar field in the symmetric tensor representation, which are eventually
fixed at their physical values. We use the effective field theory to
investigate mode spectra of inhomogeneous ground states, with focusing on
one-dimensionally inhomogeneous states, such as helical and spiral states.
Although the helical and spiral ground states share a common feature of
supporting the gapless Nambu-Goldstone modes associated with the translational
symmetry breaking, they have qualitatively different dispersion relations:
isotropic in the helical phase while anisotropic in the spiral phase. We also
discuss the magnon production induced by an inhomogeneous magnetic field, and
find a formula akin to the Schwinger formula. Our formula for the magnon
production gives a finite rate for antiferromagnets, and a vanishing rate for
ferromagnets, whereas that for ferrimagnets interpolates between the two cases.",2009.06694v1
2020-09-22,Tuning the structure of Skyrmion lattice system Cu2OSeO3 under pressure,"The insulating ferrimagnet Cu2OSeO3 shows a rich variety of phases such as
skyrmion lattice and helical magnetism controlled by interplay of different
exchange interactions which can be tuned by external pressure. In this work we
have investigated pressure-induced phase transitions at room temperature using
synchrotron based x- ray diffraction and Raman scattering measurements. With
first-principles theoretical analysis, we show that spin-spin exchange
couplings in the ambient cubic phase are affected notably by hydrostatic
pressure. The ambient cubic phase transforms to a monoclinic phase above 7 GPa
and then to the triclinic phase above 11 GPa. Emergence of new phonon modes in
the Raman spectra confirms these structural phase transitions. Notably, upon
decompression, the crystal undergoes transition to a new monoclinic structure.
Atomic coordinates have been refined in the low pressure cubic phase to capture
the Cu-tetrahedra evolution responsible for the earlier reported magnetic
behavior under pressure. Our experiments will motivate further studies of its
emergent magnetic behavior under pressure.",2009.10469v2
2020-10-09,Structural and magnetic properties of epitaxial films of CoIrMnAl equiatomic quaternary Heusler alloy designed from first-principles calculation,"MgO-barrier magnetic tunnel junctions with half-metallic Heusler alloy
electrodes attracted much attentions for spintronics applications. However, a
couples of issues related to materials still remain to be resolved for
practical uses. Recently, quarterly equiatomic Heusler alloys attracted
attentions as advanced Heusler alloys. CoIrMnZ (Z = Al, Si, Ga, and Ge)
half-metallic Heusler alloys were designed and predicted to have moderate Curie
temperatures and to be a lattice-matched with the MgO barrier, being
advantageous to traditional Co2 Heusler alloys [T. Roy et al., J. Magn. Magn.
Mater. 498, 166092 (2020)]. Here we experimentally investigated structure and
magnetic properties for thin films of one of those alloys, CoIrMnAl with a
sputtering deposition. We successfully obtained the films with the B2 chemical
ordering even with no post-annealing process. The lattice constant for the
films annealed at 500-600$^\circ$C approximates the predicted values. The
magnetization at 10 K was near 500 kA/m and the Curie temperature was
approximately 400 K were observed, which were about 70% of the values predicted
for the fully ordered structure. The magnetic properties observed in those B2
ordered films were well explained by ferrimagnetism appeared in B2 ordered
CoIrMnAl with full-swap disorders of Co-Ir and Mn-Al and almost full-swap
disorder of Co-Mn, predicted from the first-principles calculations.",2010.04369v1
2020-10-13,Dipolar-stabilized first and second-order antiskyrmions in ferrimagnetic multilayers,"Skyrmions and antiskyrmions are topologically protected spin structures with
opposite topological charge. Particularly in coexisting phases, these two types
of magnetic quasi-particles may show fascinating physics and potential for
spintronic devices. While skyrmions are observed in a wide range of materials,
until now antiskyrmions were exclusive to materials with D2d symmetry. In this
work, we show first and second-order antiskyrmions stabilized by magnetic
dipole-dipole interaction in Fe/Gd-based multilayers. We modify the magnetic
properties of the multilayers by Ir insertion layers. Using Lorentz
transmission electron microscopy imaging, we observe coexisting antiskyrmions,
Bloch skyrmions, and type-2 bubbles and determine the range of material
properties and magnetic fields where the different spin objects form and
dissipate. We perform micromagnetic simulations to obtain more insight into the
studied system and conclude that the reduction of saturation magnetization and
uniaxial anisotropy leads to the existence of this zoo of different spin
objects and that they are primarily stabilized by dipolar interaction.",2010.06555v3
2020-10-19,Interplay of mass imbalance and frustration in correlated band insulators,"We report the emergence or broadening of exotic magnetic metallic phases upon
explicit breaking of $SU(2)$ symmetry by introduction of mass imbalance in a
variant of Hubbard model, known as the ionic Hubbard model in the presence of
frustration at half-filling on a square lattice. The ionic Hubbard model has in
addition to hopping($\sim t$) and onsite coulomb repulsion ($\sim U$), a
staggered ionic potential ($\sim \Delta$) which breaks translational symmetry
of the underlying lattice. In the low to intermediate ranges of $U$ and
$\Delta$, we use unrestricted Hartree-Fock theory to construct the phase
diagram in the $U-\Delta$ plane for a fixed mass imbalance($\sim\eta$). Where
as in the limit where both $U,\Delta$ are comparable and much larger than the
first $(\sim t_{\sigma})$ and second $(\sim t_{\sigma}')$ neighbor hopping
amplitudes , we employ the technique of generalized Gutzwiller approximation
and subsequently use renormalized mean field theory to construct the phase
diagram for varying values of hopping asymmetry. In both cases, starting from a
correlated band insulator with weak antiferromagnetic spin density wave order,
if we tune $U/\Delta$, we observe the opening of novel magnetically ordered
metallic phases such as spin imbalanced ferromagnetic metal, ferrimagnetic
metal and antiferromagnetic half metal. We also study singlet superconductivity
in the d-wave and extended s-wave channels in the strong coupling limit of this
model in the presence of mass imbalance.",2010.09407v1
2020-11-01,Bipolar Magnetic Semiconducting Behavior in VNbRuAl: A New Spintronic Material for Spin Filters,"We report the theoretical prediction of a new class of spintronic materials,
namely bipolar magnetic semiconductor (BMS), which is also supported by our
experimental data. BMS acquires a unique band structure with unequal band gaps
for spin up and down channels, and thus are useful for tunable spin transport
based applications such as spin filters. The valence band (VB) and conduction
band (CB) in BMS approach the Fermi level through opposite spin channels, and
hence facilitate to achieve reversible spin polarization which are controllable
via applied gate voltage. We report the quaternary Heusler alloy VNbRuAl to
exactly possess the band structure of BMS. The alloy is found to crystallize in
LiMgPdSn prototype structure (space group $F\bar{4}3m$) with B$2$ disorder and
lattice parameter 6.15 \AA . The resistivity and Hall measurements show a two
channel semiconducting behavior and a quasi linear dependence of negative
magneto resistance (MR) indicating the possible semiconducting nature.
Interestingly, VNbRuAl also shows a fully compensated ferrimagnetic (FCF)
behavior with vanishing net magnetization (m$_s$$\sim$ $10^{-3}$ $\mu_B/f.u.$)
and significantly high ordering temperature ($> 900$ K). Unlike conventional
FCF, vanishing moment in this case appears to be the result of a combination of
long range antiferromagnetic (AFM) ordering and the inherent B2 disorder of the
crystal. This study opens up the possibility of finding a class of materials
for AFM spintronics, with great significance both from fundamental and applied
fronts.",2011.00533v1
2020-11-17,Non-local magnon-based transport in yttrium iron garnet/platinum heterostructures at high temperatures,"The spin Hall effect in a heavy metal thin film allows to probe the magnetic
properties of an adjacent magnetic insulator via magnetotransport measurements.
Here, we investigate the magnetoresistive response of yttrium iron
garnet/platinum heterostructures from room temperature to beyond the Curie
temperature $T_\mathrm{C, YIG} \approx 560\,\mathrm{K}$ of the ferrimagnetic
insulator. We find that the amplitude of the (local) spin Hall
magnetoresistance decreases monotonically from $300\,\mathrm{K}$ towards
$T_\mathrm{C}$, mimicking the evolution of the saturation magnetization of
yttrium iron garnet. Interestingly, the spin Hall magnetoresistance vanishes
around $500\,\mathrm{K}$, well below $T_\mathrm{C}$, which we attribute to the
formation of a parasitic interface layer by interdiffusion. Around room
temperature the non-local magnon-mediated magnetoresistance exhibits a power
law scaling $T^{\alpha}$ with $\alpha = 3/2$, as already reported. The exponent
decreases gradually to $\alpha \sim 1/2$ at around $420\,\mathrm{K}$, before
the non-local magnetoresistance vanishes rapidly at a similar temperature as
the spin Hall magnetoresistance. We attribute the reduced $\alpha$ at high
temperatures to the increasing thermal magnon population which leads to
enhanced scattering of the non-equilibrium magnon population and a reduced
magnon diffusion length. Finally, we find a magnetic field independent offset
voltage in the non-local signal for $T > 470\,\mathrm{K}$ which we associate
with electronic leakage currents through the normally insulating yttrium iron
garnet film. Indeed, this non-local offset voltage is thermally activated with
an energy close to the band gap.",2011.08589v1
2021-02-07,Crystal structure and properties of iron-based spin-chain compound Ba9Fe3Se15,"We report the synthesis of a new quasi one-dimensional (1D) iron selenide.
Ba9Fe3Se15 was synthesized at high temperature and high pressure of 5.5 GPa and
systematically studied via structural, magnetic and transport measurements at
ambient and at high-pressures. Ba9Fe3Se15 crystallizes in a monoclinic
structure and consists of face-sharing FeSe6 octahedral chains along the c
axis. At ambient pressure it exhibits an insulating behavior with a band gap
~460 meV and undergoes a ferrimagnet-like phase transition at 14 K. Under high
pressure, a complete metallization occurs at ~29 GPa, which is accompanied by a
spin state crossover from high spin (HS) state to low spin (LS) state. The LS
appears for pressures P >36 GPa.",2102.03708v1
2021-02-22,Robust skyrmion mediated reversal of ferromagnetic nanodots of 20 nm lateral dimension with high Ms and moderate DMI,"Implementation of skyrmion based energy efficient and high-density data
storage devices requires aggressive scaling of skyrmion size. Ferrimagnetic
materials are considered to be a suitable platform for this purpose due to
their low saturation magnetization (i.e. smaller stray field). However, we show
by performing rigorous micromagnetic simulation that such scaling of skyrmion
size by lowering saturation magnetization while applicable in infinite films or
where the skyrmion size is very small compared to the film's lateral dimension,
does not hold in confined geometries. We also found in confined geometries,
where skyrmion occupies the whole volume of a nanodot, high saturation
magnetization helps form stable skyrmions. Specifically, such skyrmions can be
formed in 20 nm lateral dimension nanodots with high saturation magnetization
(1.6-1.71 MA/m) and moderate DMI (3 mJ/m2). This result could stimulate
experiments on implementation of highly dense skyrmion devices. In particular,
we show that Voltage Controlled Magnetic Anisotropy (VCMA) based switching
mediated by an intermediate skyrmion state can be achieved in the soft layer of
a ferromagnetic p-MTJ of lateral dimensions 20 nm with sub 1fJ/bit energy in
the presence of room temperature thermal noise with reasonable DMI ~3 mJ/m2.",2102.10721v1
2021-02-24,Unusual direction-dependent magnetic orbital moment obtained from X-ray magnetic circular dichroism in a multiferroic oxide system,"The electric-field control of $d$-electron magnetism in multiferroic
transition metal oxides is attracting widespread interest for the underlying
fundamental physics and for next generation spintronic devices. Here, we report
an extensive study of the $3d$ magnetism in magnetoelectric
Ga$_{0.6}$Fe$_{1.4}$O$_3$ (GFO) epitaxial films by polarization dependent x-ray
absorption spectroscopy. We found a non-zero integral of the x-ray magnetic
circular dichroism, with a sign depending upon the relative orientation between
the external magnetic field and the crystallographic axes. %By reliably
enlarging the limit of the spin and orbital sum rules, which usually holds for
materials where the magnetic ions exhibit a unique crystal field symmetry This
finding translates in a sign-reversal between the average Fe magnetic orbital
and spin moments. Large Fe-displacements, among some of the octahedral sites,
lower the symmetry of the system producing anisotropic paths for the Fe-O
bondings giving rise to a large orbital-lattice interaction akin to a
preferential crystallographic direction for the magnetic orbital moment. The
latter may lead to a partial re-orientation of the magnetic orbital moment
under an external magnetic field that, combined to the ferrimagnetic nature of
the GFO, can qualitatively explain the observed sign-reversal of the XMCD
integral. The results suggest that a control over the local symmetry of the
oxygen octahedra in transition metal oxides can offer a suitable leverage over
the manipulation of the effective orbital and spin moments in magnetoelectric
systems.",2102.12118v2
2021-03-18,An antisite defect mechanism for room temperature ferroelectricity in orthoferrites,"Single-phase multiferroic materials that allow the coexistence of
ferroelectric and magnetic ordering above room temperature are highly
desirable, motivating an ongoing search for mechanisms for unconventional
ferroelectricity in magnetic oxides. Here, we report an antisite defect
mechanism for room temperature ferroelectricity in epitaxial thin films of
yttrium orthoferrite, YFeO3, a perovskite-structured canted antiferromagnet. A
combination of piezoresponse force microscopy, atomically resolved elemental
mapping with aberration corrected scanning transmission electron microscopy and
density functional theory calculations reveals that the presence of YFe
antisite defects facilitates a non-centrosymmetric distortion promoting
ferroelectricity. This mechanism is predicted to work analogously for other
rare earth orthoferrites, with a dependence of the polarization on the radius
of the rare earth cation. Furthermore, a vertically aligned nanocomposite
consisting of pillars of a magnetoelastic oxide CoFe2O4 embedded epitaxially in
the YFeO3 matrix exhibits both robust ferroelectricity and ferrimagnetism at
room temperature, as well as a noticeable strain-mediated magnetoelectric
coupling effect. Our work uncovers the distinctive role of antisite defects in
providing a novel mechanism for ferroelectricity in a range of magnetic
orthoferrites and further augments the functionality of this family of complex
oxides for multiferroic applications.",2103.10338v1
2021-04-12,Spin-flop led peculiar behavior of temperature-dependent anomalous Hall effect in Hf/Gd-Fe-Co,"Here we investigate the temperature dependence of anomalous Hall effect in
Hf/GdFeCo/MgO sheet film and Hall bar device. The magnetic compensation
temperature ($T_{comp}$) for the sheet film and device is found to be ~240 K
and ~118 K, respectively. In sheet film, spin-flopping is witnessed at a
considerably lower field, 0.6 T, close to $T_{comp}$. The AHE hysteresis loops
in the sheet film have a single loop whereas in the Hall bar device, hystereses
consist of triple loops are observed just above the Tcomp. Moreover, the
temperature-dependent anomalous Hall resistance ($R_\mathrm{AHE}$) responds
unusually when a perpendicular magnetic field is applied while recording the
$R_\mathrm{AHE}$. The zero-field $R_\mathrm{AHE}$ scan suggests the Hall signal
generates solely from the FeCo moment. However, the behavior of 3 T-field
$R_\mathrm{AHE}$ scan in which the $R_\mathrm{AHE}$ drops close to zero near
the $T_{comp}$ seems to be following the net magnetization response of the
device, is explained by considering the low field spin-flopping around the
compensation temperature. The results presented here give important insight to
understand the complex AHE behavior of ferrimagnets for their spintronic
applications.",2104.05193v2
2021-04-14,"On the complexity of spinels: Magnetic, electronic, and polar ground states","This review summarizes more than 100 years of research on spinel compounds,
mainly focusing on the progress in understanding their magnetic, electronic,
and polar properties during the last two decades. Many spinel compounds are
magnetic insulators or semiconductors; however, a number of spinel-type metals
exists including superconductors and some rare examples of d-derived
heavy-fermion compounds. In the early days, they gained importance as
ferrimagnetic or even ferromagnetic insulators with relatively high saturation
magnetization and high ordering temperatures, with magnetite being the first
magnetic mineral known to mankind. However, spinels played an outstanding role
in the development of concepts of magnetism, in testing and verifying the
fundamentals of magnetic exchange, in understanding orbital-ordering and
charge-ordering phenomena. In addition, the A- site as well as the B-site
cations in the spinel structure form lattices prone to strong frustration
effects resulting in exotic ground-state properties. In case the A-site cation
is Jahn-Teller active, additional entanglements of spin and orbital degrees of
freedom appear, which can give rise to a spin-orbital liquid or an orbital
glass state. The B-site cations form a pyrochlore lattice, one of the strongest
contenders of frustration in three dimensions. In addition, in spinels with
both cation lattices carrying magnetic moments, competing magnetic exchange
interactions become important, yielding ground states like the time-honoured
triangular Yafet-Kittel structure. Finally, yet importantly, there exists a
long-standing dispute about the possibility of a polar ground state in spinels,
despite their reported overall cubic symmetry. Indeed, over the years number of
multiferroic spinels were identified.",2104.06889v1
2021-04-19,Magnetic coupling in Y$_3$Fe$_5$O$_{12}$/Gd$_3$Fe$_5$O$_{12}$ heterostructures,"Ferrimagnetic Y$_3$Fe$_5$O$_{12}$ (YIG) is the prototypical material for
studying magnonic properties due to its exceptionally low damping. By
substituting the yttrium with other rare earth elements that have a net
magnetic moment, we can introduce an additional spin degree of freedom. Here,
we study the magnetic coupling in epitaxial
Y$_3$Fe$_5$O$_{12}$/Gd$_3$Fe$_5$O$_{12}$ (YIG/GIG) heterostructures grown by
pulsed laser deposition. From bulk sensitive magnetometry and surface sensitive
spin Seebeck effect (SSE) and spin Hall magnetoresistance (SMR) measurements,
we determine the alignment of the heterostructure magnetization through
temperature and external magnetic field. The ferromagnetic coupling between the
Fe sublattices of YIG and GIG dominates the overall behavior of the
heterostructures. Due to the temperature dependent gadolinium moment, a
magnetic compensation point of the total bilayer system can be identified. This
compensation point shifts to lower temperatures with increasing thickness of
YIG due the parallel alignment of the iron moments. We show that we can control
the magnetic properties of the heterostructures by tuning the thickness of the
individual layers, opening up a large playground for magnonic devices based on
coupled magnetic insulators. These devices could potentially control the magnon
transport analogously to electron transport in giant magnetoresistive devices.",2104.09592v1
2021-04-30,A numerical exploration of signal detector arrangement in a spin-wave reservoir computing device,"This paper studies numerically how the signal detector arrangement influences
the performance of reservoir computing using spin waves excited in a
ferrimagnetic garnet film. This investigation is essentially important since
the input information is not only conveyed but also transformed by the spin
waves into high-dimensional information space when the waves propagate in the
film in a spatially distributed manner. This spatiotemporal dynamics realizes a
rich reservoir-computational functionality. First, we simulate spin waves in a
rectangular garnet film with two input electrodes to obtain spatial
distributions of the reservoir states in response to input signals, which are
represented as spin vectors and used for a machine-learning waveform
classification task. The detected reservoir states are combined through readout
connection weights to generate a final output. We visualize the spatial
distribution of the weights after training to discuss the number and positions
of the output electrodes by arranging them at grid points, equiangularly
circular points or at random. We evaluate the classification accuracy by
changing the number of the output electrodes, and find that a high accuracy
($>$ 90\%) is achieved with only several tens of output electrodes regardless
of grid, circular or random arrangement. These results suggest that the spin
waves possess sufficiently complex and rich dynamics for this type of tasks.
Then we investigate in which area useful information is distributed more by
arranging the electrodes locally on the chip. Finally, we show that this device
has generalization ability for input wave-signal frequency in a certain
frequency range. These results will lead to practical design of spin-wave
reservoir devices for low-power intelligent computing in the near future.",2104.14915v1
2021-05-10,Valley polarization of trions in monolayer MoSe$_2$ interfaced with bismuth iron garnet,"Interfacing atomically thin van der Waals semiconductors with magnetic
substrates enables additional control on their intrinsic valley degree of
freedom and provides a promising platform for the development of novel
valleytronic devices for information processing and storage. Here we study
circularly polarized photoluminescence in heterostructures of monolayer
MoSe$_2$ and thin films of ferrimagnetic bismuth iron garnet. We observe strong
emission from charged excitons with negative valley polarization, which
switches sign with increasing temperature, and demonstrate contrasting response
to left and right circularly polarized excitation, associated with finite
out-of-plane magnetization in the substrate. We propose a theoretical model
accounting for magnetization-induced imbalance of charge carriers in the two
valleys of MoSe$_2$, as well as for valley-switching scattering from B to A
excitons and fast formation of trions with extended valley relaxation times,
which shows excellent agreement with the experimental data. Our results provide
new insights into valley physics in 2D semiconductors interfaced with magnetic
substrates.",2105.04327v2
2021-05-24,Role of two-dimensional Ising superconductivity in the non-equilibrium quasiparticle spin-to-charge conversion efficiency,"Non-equilibrium studies of two-dimensional (2D) superconductors (SCs) with
Ising spin-orbit coupling are prerequisite for their successful application to
equilibrium spin-triplet Cooper pairs and, potentially, Majorana fermions. By
taking advantage of the recent discoveries of 2D SCs and their compatibility
with any other materials, we fabricate here non-local magnon devices to examine
how such 2D Ising superconductivity affects the conversion efficiency of magnon
spin to quasiparticle charge in superconducting flakes of 2H-NbSe2 transferred
onto ferrimagnetic insulating Y3Fe5O12. Comparison with a reference device
based on a conventionally paired superconductor shows that the Y3Fe5O12-induced
in-plane (IP) exchange spin-splitting in the NbSe2 flake is hindered by its
inherent out-of-plane (OOP) spin-orbit-field, which, in turn, limits the
transition-state enhancement of the spin-to-charge conversion efficiency. Our
out-of-equilibrium study highlights the significance of symmetry matching
between underlying Cooper pairs and exchange-induced spin-splitting for the
giant transition-state spin-to-charge conversion and may have implications
towards proximity-engineered spin-polarized triplet pairing via tuning the
relative strength of IP exchange and OOP spin-orbit fields in ferromagnetic
insulator/2D Ising SC bilayers.",2105.11159v4
2021-05-26,"Flat bands, electron interactions and magnetic order in magic-angle mono-trilayer graphene","Starting with twisted bilayer graphene, graphene-based moir\'e materials have
recently been established as a new platform for studying strong electron
correlations. In this paper, we study twisted graphene monolayers on trilayer
graphene and demonstrate that this system can host flat bands when the twist
angle is close to the magic-angle of 1.16$^\circ$. When monolayer graphene is
twisted on ABA trilayer graphene, the flat bands are not isolated, but are
intersected by a Dirac cone with a large Fermi velocity. In contrast, graphene
twisted on ABC trilayer graphene (denoted AtABC) exhibits a gap between flat
and remote bands. Since ABC trilayer graphene and twisted bilayer graphene are
known to host broken-symmetry phases, we further investigate the ostensibly
similar magic angle AtABC system. We study the effect of electron-electron
interactions in AtABC using both Hartree theory and an atomic Hubbard theory to
calculate the magnetic phase diagram as a function of doping, twist angle, and
perpendicular electric field. Our analysis reveals a rich variety of magnetic
orderings, including ferromagnetism and ferrimagnetism, and demonstrates that a
perpendicular electric field makes AtABC more susceptible to magnetic ordering.",2105.12641v2
2021-06-29,Neutron Scattering Study on Yttrium Iron Garnet for Spintronics,"Spin current -- a flow of the spin degree of freedom in matter -- has vital
importance in spintronics. Propagation of the spin current ranges over a whole
momentum space; however, generated spin currents are mainly detected in the
long-wavelength limit. To facilitate practical uses of spintronics and
magnonics, microscopic understanding of the spin current is necessary. We here
address yttrium iron garnet, which is a well-employed ferrimagnet for
spintronics, and review {\it in re} the momentum- and energy-resolved
characteristics of its magnetism. Using {\it unpolarized} neutrons, we refined
its detailed crystal and magnetic structure, and examined magnetic excitations
through four decades (10~$\mu$eV-100~meV) using chopper spectrometers in
J-PARC, Japan. We also measured mode-resolved directions of the precessional
motion of the magnetic moment, i.e., magnon polarization, which carries the
spin current in insulators through {\it polarized} neutron scattering, using a
triple-axis spectrometer in ILL, France. The magnon polarization is a hitherto
untested fundamental property of magnets, affecting the thermodynamic
properties of the spin current. Our momentum- and energy-resolved experimental
findings provide an intuitive understanding of the spin current and demonstrate
the importance of neutron scattering techniques for spintronics and magnonics.",2106.15752v1
2021-08-05,Metamagnetic Transitions in Few-Layer CrOCl Controlled by Magnetic Anisotropy Flipping,"The pivotal role of magnetic anisotropy in stabilising two-dimensional (2D)
magnetism has been widely accepted, however, direct correlation between
magnetic anisotropy and long-range magnetic ordering in the 2D limit is yet to
be explored. Here, using angle- and temperature-dependent tunnelling
magnetoresistance, we report unprecedented metamagnetic phase transitions in
atomically-thin CrOCl, triggered by magnetic easy-axis flipping instead of the
conventional spin flop mechanism. Few-layer CrOCl tunnelling devices of various
thicknesses consistently show an in-plane antiferromagnetic (AFM) ground state
with the easy axis aligned along the Cr-O-Cr direction (b-axis). Strikingly,
with the presence of a magnetic field perpendicular to the easy-axis (H||c),
magnetization of CrOCl does not follow the prevalent spin rotation and
saturation pattern, but rather exhibits an easy-axis flipping from the in-plane
to out-of-plane directions. Such magnetic anisotropy controlled metamagnetic
phase transitions are manifested by a drastic upturn in tun- nelling current,
which shows anomalous shifts towards higher H when temperature increases. By 2D
mapping of tunnelling currents as a function of both temperature and H, we
determine a unique ferrimagnetic state with a superstructure periodicity of
five unit cells after the field-induced metam- agnetic transitions. The
feasibility to control 2D magnetism by manipulating magnetic anisotropy may
open enormous opportunities in spin-based device applications.",2108.02825v1
2021-08-19,Quantized edge magnetizations and their symmetry protection in one-dimensional quantum spin systems,"The bulk electric polarization works as a nonlocal order parameter that
characterizes topological quantum matters. Motivated by a recent paper [H.
Watanabe \textit{et al.}, Phys. Rev. B {\bf 103}, 134430 (2021)], we discuss
magnetic analogs of the bulk polarization in one-dimensional quantum spin
systems, that is, quantized magnetizations on the edges of one-dimensional
quantum spin systems.The edge magnetization shares the topological origin with
the fractional edge state of the topological odd-spin Haldane phases. Despite
this topological origin, the edge magnetization can also appear in
topologically trivial quantum phases. We develop straightforward field
theoretical arguments that explain the characteristic properties of the edge
magnetization. The field theory shows that a U(1) spin-rotation symmetry and a
site-centered or bond-centered inversion symmetry protect the quantization of
the edge magnetization. We proceed to discussions that quantum phases on
nonzero magnetization plateaus can also have the quantized edge magnetization
that deviates from the magnetization density in bulk. We demonstrate that the
quantized edge magnetization distinguishes two quantum phases on a
magnetization plateau separated by a quantum critical point. The edge
magnetization exhibits an abrupt stepwise change from zero to $1/2$ at the
quantum critical point because the quantum phase transition occurs in the
presence of the symmetries protecting the quantization of the edge
magnetization. We also show that the quantized edge magnetization can result
from the spontaneous ferrimagnetic order.",2108.08458v2
2021-09-08,Picosecond creation of switchable optomagnets with giant photoinduced Kerr rotations in polar antiferromagnetic (Fe$_{1-x}$Zn$_{x}$)$_{2}$Mo$_{3}$O$_{8}$,"On-demand spin orientation with long polarized lifetime and easily detectable
signal is an ultimate goal for spintronics. However, there still exists a
trade-off between controllability and stability of spin polarization, awaiting
a significant breakthrough. Here, we demonstrate switchable optomagnet effects
in (Fe$_{1-x}$Zn$_{x}$)$_{2}$Mo$_{3}$O$_{8}$, from which we can obtain tunable
magnetization, spanning from -40$\%$ to 40$\%$ of a saturated magnetization
that is created from zero magnetization in the antiferromagnetic state without
magnetic fields. It is accomplishable via utilizing circularly-polarized laser
pulses to excite spin-flip transitions in polar antiferromagnets that have no
spin canting, traditionally hard to control without very strong magnetic
fields. The spin controllability in (Fe$_{1-x}$Zn$_{x}$)$_{2}$Mo$_{3}$O$_{8}$
originates from its polar structure that breaks the crystal inversion symmetry,
allowing distinct on-site $d$-$d$ transitions for selective spin flip. By
chemical doping, we exploit the phase competition between antiferromagnetic and
ferrimagnetic states to enhance and stabilize the optomagnet effects, which
result in long-lived photoinduced Kerr rotations. The present study, creating
switchable giant optomagnet effects in polar antiferromagnets, sketches a new
blueprint for the function of antiferromagnetic spintronics.",2109.03498v1
2021-09-11,Dzyaloshinskii interaction and exchange-relativistic effects in orthoferrites,"We present an overview of the microscopic theory of the Dzyaloshinskii-Moriya
(DM) coupling and related exchange-relativistic effects such as exchange
anisotropy, electron-nuclear antisymmetric supertransferred hyperfine
interactions, antisymmetric magnetogyrotropic effects, and antisymmetric
magnetoelectric coupling in strongly correlated 3$d$ compounds focusing on
orthoferrites RFeO$_3$ (R is a rare-earth ion or yttrium Y). % Particular
emphasis will be placed on the role of crystal field effects, the sense and
direction of the Dzyaloshinskii vector, its dependence on the superexchange
bonding geometry, and other subtle features of exchange-relativistic effects.
Most attention in the paper centers around the derivation of the Dzyaloshinskii
vector, its value, orientation, and sense (sign) under different types of the
(super)exchange interaction and crystal field. Microscopically derived
expression for the dependence of the Dzyaloshinskii vector on the superexchange
geometry allows one to find all the overt and hidden canting angles in
orthoferrites RFeO$_3$ as well as corresponding contribution to magnetic
anisotropy. Being based on the theoretical predictions regarding the sign of
the Dzyaloshinskii vector we have predicted and study in detail a novel
magnetic phenomenon, {\it weak ferrimagnetism} in mixed weak ferromagnets with
competing signs of the Dzyaloshinskii vectors. The ligand NMR measurements in
weak ferromagnets are shown to be an effective tool to inspect the effects of
DM coupling in an external magnetic field. Along with orthoferrites RFeO$_3$
and weak ferrimagnets RFe$_{1-x}$Cr$_x$O$_3$, although to a lesser extent, we
address such typical weak ferromagnets as $\alpha$-Fe$_2$O$_3$, FeBO$_3$, and
FeF$_3$.",2109.05326v1
2021-10-12,Anisotropically large anomalous and topological Hall effect in a kagome magnet,"Recently, kagome materials have become an engrossing platform to study the
interplay among symmetry, magnetism, topology, and electron correlation. The
latest works on RMn6Sn6 (R = rare earth metal) compounds have illustrated that
this family could be intriguing to investigate various physical phenomena due
to large spin-orbit coupling and strong magnetic ordering. However, combined
transport and spectroscopic studies in RMn6Sn6 materials are still limited.
Here, we report magnetic, magneto-transport, and angle-resolved photoemission
spectroscopy measurements of a kagome magnet ErMn6Sn6 that undergoes
antiferromagnetic (TN = 345 K) to ferrimagnetic (TC = 68 K) phase transitions
in the presence of field. We observe large anomalous and topological Hall
effects serving as transport signatures of the nontrivial Berry curvature. The
isothermal magnetization exhibits strong anisotropic nature and the topological
Hall effect of the compound depends on the critical field of metamagnetic
transition. Our spectroscopic results complemented by theoretical calculations
show the multi-orbital kagome fermiology. This work provides new insight into
the tunability and interplay of topology and magnetism in a kagome magnet.",2110.06012v1
2021-10-27,Unusual magnetic and transport properties in HoMn$_6$Sn$_6$ kagome magnet,"With intricate lattice structures, kagome materials are an excellent platform
to study various fascinating topological quantum states. In particular, kagome
materials, revealing large responses to external stimuli such as pressure or
magnetic field, are subject to special investigation. Here, we study the
kagome-net HoMn$_6$Sn$_6$ magnet that undergoes paramagnetic to ferrimagnetic
transition (below 376 K) and reveals spin-reorientation transition below 200 K.
In this compound, we observe the topological Hall effect and substantial
contribution of anomalous Hall effect above 100 K. We unveil the pressure
effects on magnetic ordering at a low magnetic field from the pressure tunable
magnetization measurement. By utilizing high-resolution angle-resolved
photoemission spectroscopy, Dirac-like dispersion at the high-symmetry point K
is revealed in the vicinity of the Fermi level, which is well supported by the
first-principles calculations, suggesting a possible Chern-gapped Dirac cone in
this compound. Our investigation will pave the way to understand the
magneto-transport and electronic properties of various rare-earth-based kagome
magnets.",2110.14155v1
2021-11-09,Tunable intrinsic ferromagnetic topological phases in bulk van der Waals crystal MnSb6Te10,"Intrinsic ferromagnetism is a crucial ingredient to realize quantum anomalous
Hall effect in quasi two dimensional materials, thus the search of intrinsic
ferromagnetic topological materials is one of the most concerned issues in the
field of topological phases of matter. In this work, combining magnetotransport
measurements, first principles calculations, and angle-resolved photoemission
spectroscopy studies, we find that in MnSb6Te10, the n = 2 member of the
MnSb2Te4/(Sb2Te3)n family, the strong magnetic competition realizes a fragile
ferromagnetic ground state, which whereas easily enters into ferrimagnetic and
the Z_2 antiferromagnetic topological insulator phase with warming to higher
temperature. Interestingly, the system stays in an inversion-symmetry-protected
axion insulator phase in the ferromagnetic ground state as well as in the
external magnetic field driven spin-polarized FM phase and can be converted
into a Weyl semimetal with multiple Weyl nodes in the valence bands with hole
doping, which are manifested by the measured notable intrinsic anomalous Hall
effect. Our work thus provides an intrinsic magnetic topological material which
is highly tunable into versatile topological phases by temperature, magnetic
field, as well as carrier doping.",2111.04973v1
2021-11-24,Braiding higher-order Majorana corner states through their spin degree of freedom,"In this work, we study the spin texture of a class of higher-order
topological superconductors (HOTSC) and show how it can be used to detect and
braid Majorana corner modes (MCMs). This class of HOTSC is composed of
two-dimensional topological insulators with s-wave superconductivity and
in-plane magnetic fields, which offers advantages in experimental
implementation. The spin polarization of the MCMs in this class is
perpendicular with the applied magnetic field direction and is opposite on
intrinsic orbitals, resulting in an overall ferrimagnetic spin texture. As a
result, we find that the spin-selective Andreev reflection can be observed in a
transverse instead of parallel direction to the applied magnetic field.
Meanwhile, this spin texture leads to the gate-tunable $4\pi$ periodic $\phi_0$
Josephson current that performs qualitatively different behavior from the
topologically trivial $\phi_0$-junction under rotating the in-plane magnetic
field. Meanwhile, the existence of the MCMs in this class does not depend on
the in-plane magnetic field direction. This gives rise to great advantage in
constructing all electronically controlled Majorana network for braiding, which
is confirmed through our numerical simulation. We thus provide a comprehensive
scheme for probing non-Abelian statistics in this class of HOTSCs.",2111.12359v1
2021-11-29,Single-pulse all-optical switching in amorphous Dy$_x$Co$_{1-x}\text{ }$ and Tb$_x$Co$_{1-x}$,"Repeated uniform switching of the magnetization of thin films of
ferrimagnetic amorphous Gd$_{x}$(FeCo)$_{1-x}$ in response to single fast laser
pulses is well established. Here we report unusual toggle switching in thin
films of sperimagnetic amorphous Dy$_x$Co$_{1-x}$ and Tb$_x$Co$_{1-x}$ with
$\it{x} \simeq$ 0.25 irradiated with single 200 fs pulses of 800 nm laser
light. The samples have strong local random anisotropy due to the non-S state
rare earth. The compensation temperature of the films is $\le$ 180 K and their
Curie temperature is $\simeq$ 500 K. They are mostly switched by the first
pulse, and subsequent pulses lead to partial re-switching of a decreasing
amount of the irradiated area, with a granular structure of submicron regions
of switched and unswitched material. Individual switched domains about 700 nm
in size are observed around the edge of the irradiated spots where the fluence
is at the threshold for switching. Results are discussed in terms of a random
anisotropy model where the ratio of local anisotropy to exchange is temperature
dependent and close to the threshold for strong pinning.",2111.14587v1
2021-11-30,Evidence for Emergent Kagome Spin Configuration with Concomitant Transverse and Longitudinal Spin-Glass Freezing in the Chemically Ordered M-type Hexaferrite BaFe12O19,"Frustration effects in magnetic systems have traditionally been investigated
considering pre-existing site-disorder or lattice geometry of the
high-temperature paramagnetic phase. We present here evidence for emergence of
geometrical frustration as a function of temperature due to spin canting in the
long-range ordered (LRO) ferrimagnetic (FMI) phase of BaFe12O19 (BFO), an
M-type hexaferrite of enormous technological applications. Results of neutron
scattering and magnetic susceptibility studies on BFO are presented to show for
the first time the emergence of highly degenerate kagome spin configuration for
the basal plane spin component of BFO with concomitant freezing of transverse
and longitudinal components of the spins leading to two spin-glass transitions
in coexistence with the LRO FMI phase. Our results mimic the theoretical
predictions for concentrated Heisenberg systems even though the source of
frustration in BFO is the geometry of the lattice and not site-disorder. We
believe that our findings will stimulate theoretical studies to unravel the
physics of spin-glass transitions in LRO systems due to emergent geometrical
frustration, an aspect that has remained unexplored so far. We also believe
that this work will encourage further experimental studies in search of low
temperature spin-glass transition(s) in LRO phases of various hexaferrites and
even other LRO magnetic compounds with spins arranged on triangular, pyrochlore
and spinel lattices without any substitutional disorder.",2111.15610v1
2022-01-01,Giant widening of interface magnetic layer in almost compensated iron garnet,"A two-sublattice ferrimagnet undergoes a transition from a collinear to
canted magnetic phase at magnetic field oriented along an easy magnetization
direction. In this work, we study the transition by means of the
magneto-optical Faraday effect in a thin film of compensated iron garnet
(Lu$_{3-{\rm{x}}}$Bi$_{\rm{x}}$)(Fe$_{5-{\rm{y}}-{\rm{z}}}$Ga$_{\rm{y}}$Al$_{\rm{z}}$)O$_{12}$
grown on Gd$_3$Ga$_5$O$_{12}$ substrate. In the immediate vicinity of the
compensation temperature a precursor of the transition with a complex shape was
observed. Using a special sample with variable thickness we demonstrate an
interfacial origin of the precursor. Diffusion of gadolinium from the substrate
into the film forms a thin intermixed layer with enhanced magnetization. It
induces an extended inhomogeneous magnetic structure in the film. A two-step
shape of the precursor appears due to an easy-plane anisotropy of the
intermixed magnetic layer. We emphasize that an effective width of the
inhomogeneous magnetization distribution in the film grows enormously while
approaching the compensation temperature.",2201.00134v1
2022-01-19,NdAlSi: a magnetic Weyl semimetal candidate with rich magnetic phases and atypical transport properties,"Magnetic Weyl semimetals (MWSM) have attracted significant attention due to
their intriguing physical properties and potential applications in
spin-electronic devices. Here we report the characterization of NdAlSi
including transport, magnetization, and heat capacity on single crystals, as
well as band structure calculation. It is a newly proposed MWSM candidate which
breaks both time-reversal and spacial inversion symmetries. A
temperature-magnetic field phase diagram is experimentally established.
Remarkably, on the angular magnetoresistance (AMR), a two-fold symmetric sharp
peak instead of a smooth variation is observed in the field-induced
ferrimagnetic phase. We argue that the tunability of both the topological and
magnetic properties in NdAlSi is crucial for realizing such a behavior. Our
results indicate that 4f-electron-based MWSM can provide a unique platform to
explore new and intriguing quantum phenomena arising from the interaction
between magnetism and topology.",2201.07430v2
2022-03-21,Magnon squeezing enhanced ground-state cooling in cavity magnomechanics,"Cavity magnomechanics has recently become a new platform for studying
macroscopic quantum phenomena. The magnetostriction induced vibration mode of a
large-size ferromagnet or ferrimagnet reaching its ground state represents a
genuine macroscopic quantum state. Here we study the ground-state cooling of
the mechanical vibration mode in a cavity magnomechanical system, and focus on
the role of magnon squeezing in improving the cooling efficiency. The magnon
squeezing is obtained by exploiting the magnon self-Kerr nonlinearity. We find
that the magnon squeezing can significantly and even completely suppress the
magnomechanical Stokes scattering. It thus becomes particularly useful in
realizing ground-state cooling in the unresolved-sideband regime, where the
conventional sideband cooling protocols become inefficient. We also find that
the coupling to the microwave cavity plays only an adverse effect in mechanical
cooling. This makes essentially the two-mode magnomechanical system (without
involving the microwave cavity) a preferred system for cooling the mechanical
motion, in which the magnon mode is established by a uniform bias magnetic
field and a microwave drive field.",2203.10767v4
2022-03-31,Origin of spin reorientation and intrinsic anomalous Hall effect in the kagome ferrimagnet TbMn6Sn6,"TbMn$_6$Sn$_6$ has attracted a lot of recent interest for a variety of
reasons, most importantly, because of the hypothesis that it may support
quantum-limit Chern topological magnetism, derived from the kagome geometry.
Besides, TbMn$_6$Sn$_6$ features a highly unusual magnetic reorientation
transition about 100 K below the Curie point, whereby all spins in the system,
remaining collinear, rotate by 90$^\circ$. In this work, we address both issues
combining experiment, mean-field theory and first-principle calculations. Both
magnetic reorientation and the unusual temperature dependence of the anomalous
Hall conductivity (AHC) find quantitative explanation in the fact that Mn and
Tb, by virtue of the Mermin-Wagner theorem, have very different spin dynamics,
with Tb spins experiencing much more rapid fluctuation. We were able to cleanly
extract the intrinsic AHC from our experiment, and calculated the same
microscopically, with good semiquantitative agreement. We have identified the
points in the band structure responsible for the AHC and showed that they are
not the kagome-derived Dirac points at the K-corner of the Brillouin zone, as
conjectured previously.",2203.17246v1
2022-05-23,Direct Determination of Spin-Splitting Energy in Magnetic Graphene by Landau Fan Shifts,"Spin-polarized two-dimensional materials with large and tunable
spin-splitting energy promise the field of 2D spintronics. While graphene has
been a canonical 2D material, its spin properties and tunability are limited.
Here, we demonstrate the emergence of robust spin-polarization in graphene with
large and tunable spin-splitting energy of up to 132 meV at zero applied
magnetic fields. The spin polarization is induced through a magnetic exchange
interaction between graphene and the underlying ferrimagnetic oxide insulating
layer, Tm3Fe5O12, as confirmed by its X-ray magnetic circular dichroism. The
spin-splitting energies are directly measured and visualized by the shift in
their landau fan diagram mapped by analyzing the measured subnikov-de-Haas
oscillations as a function of applied electric fields, showing consistent fit
with our first-principles and machine learning calculations. Further, the
observed spin-splitting energies can be tuned over a broad range between 98 and
166 meV by cooling fields. Our methods and results are applicable to other
two-dimensional (magnetic) materials and heterostructures, and offer great
potential for developing next-generation spin logic and memory devices.",2205.11042v2
2022-06-04,Perspective on Epitaxial NiCo2O4 Film as an Emergent Spintronic Material: Magnetism and Transport Properties,"The ferrimagnetic inverse spinel NiCo2O4 has attracted extensive research
interests for its versatile electrochemical properties, robust magnetic order,
high conductivity, and fast spin dynamics, as well as its highly tunable nature
due to the closely coupled charge, spin, orbital, lattice, and defect effects.
Single-crystalline epitaxial thin films of NiCo2O4 present a model system for
elucidating the intrinsic physical properties and strong tunability, which are
not viable in bulk single crystals. In this perspective, we discuss the recent
advances in epitaxial NiCo2O4 thin films, focusing on understanding its unusual
magnetic and transport properties in light of crystal structure and electronic
structure. The perpendicular magnetic anisotropy in compressively strained
NiCo2O4 films is explained by considering the strong spin-lattice coupling,
particularly on Co ions. The prominent effect of growth conditions reveals the
complex interplay between the crystal structure, cation stoichiometry, valence
state, and site occupancy. NiCo2O4 thin films also exhibit various
magnetotransport anomalies, including linear magnetoresistance and sign change
in anomalous Hall effect, which illustrate the competing effects of band
intrinsic Berry phase and impurity scattering. The fundamental understanding of
these phenomena will facilitate the functional design of NiCo2O4 thin films for
nanoscale spintronic applications.",2206.02021v1
2022-07-25,"Creating and controlling Dirac fermions, Weyl fermions, and nodal lines in the magnetic antiperovskite Eu$_3$PbO","The band topology of magnetic semimetals is of interest both from the
fundamental science point of view and with respect to potential spintronics and
memory applications. Unfortunately, only a handful of suitable topological
semimetals with magnetic order have been discovered so far. One such family
that hosts these characteristics is the antiperovskites, A$_3$BO, a family of
3D Dirac semimetals. The A=Eu$^{2+}$ compounds magnetically order with multiple
phases as a function of applied magnetic field. Here, by combining band
structure calculations with neutron diffraction and magnetic measurements, we
establish the antiperovskite Eu$_3$PbO as a new topological magnetic semimetal.
This topological material exhibits a multitude of different topological phases
with ordered Eu moments which can be easily controlled by an external magnetic
field. The topological phase diagram of Eu$_3$PbO includes an antiferromagnetic
Dirac phase, as well as ferro- and ferrimagnetic phases with both Weyl points
and nodal lines. For each of these phases, we determine the bulk band
dispersions, the surface states, and the topological invariants by means of
$\textit{ab-initio}$ and tight-binding calculations. Our discovery of these
topological phases introduces Eu$_3$PbO as a new platform to study and
manipulate the interplay of band topology, magnetism, and transport.",2207.12434v1
2022-08-09,Valence state and lattice incorporation of Ni in Zn/Co-based magnetic oxides,"Ni incorporation has been studied in a comprehensive range of Zn/Co-based
magnetic oxides to elucidate it valence state and lattice incorporation. The
resulting structural and magnetic properties are studied in detail. To the one
end Ni in incorporated by in-diffusion as well as reactive magnetron
co-sputtering in wurtzite ZnO where only the Ni-diffused ZnO exhibits
significant conductivity. This is complemented by Ni and Co codoping of ZnO
leading. To the other end, the ZnCo$_2$O$_4$ spinel is co-doped with varying
amounts of Ni. In the wurtzite oxides Ni is exclusively found on tetrahedral
lattice sites in its formal 2+ oxidation state as deep donor. It behaves as an
anisotropic paramagnet and a limited solubility of Ni about 10\% is found. Due
to its smaller magnetic moment it can induce partial uncompensation of the Co
magnetic moments due to antiferromagnetic coupling. In the spinel Ni is found
to be incorporated in its formal 3+ oxidation state on octahedral sites and
couples antiferromagnetically to the Co moments leading again to magnetic
uncompensation of the otherwise antiferromagnetic ZnCo$_2$O$_4$ spinel and to
ferrimagnetism at higher Ni concentrations. Increasing Ni even further leads to
phase separation of cubic NiO resulting in an exchange-biased composite
magnetic oxide.",2208.11086v1
2022-08-25,"Incommensurate magnetic modulation in K-rich cryptomelane, K$_x$Mn$_8$O$_{16}$ ($x\approx1.46$)","Cryptomelane is a hollandite-like material consisting of K$^+$ cations in an
$\alpha$-MnO$_2$ tunnel-like crystallographic motif. A sample with
stoichiometry K$_{1.461(4)}$Mn$_8$O$_{16}$ has been synthesised and its
magnetic properties investigated using variable-temperature magnetic
susceptibility, heat capacity, and neutron powder diffraction. Three distinct
magnetic transitions at $184$\,K, $54.5$\,K, and $24$\,K are assigned to
K$_{1.461(4)}$Mn$_8$O$_{16}$. Magnetic Bragg peaks emerge below $54.5$\,K, and
from their positions they indicate a modulated magnetic structure which is
incommensurate with the crystallographic nuclear structure. The model
consistent with the data is a dual-$\vec{k}_\mathrm{mag}$ structure with a
canted ferrimagnetic $\vec{k}_\mathrm{mag}=0$ component and an incommensurate
$\vec{k}_\mathrm{mag}=(0,0,k_z)$ [$k_z=0.36902(15)$] component, with the latter
most likely to be of the helical type formerly proposed for this material.
Below 24\,K, there is a magnetic transition, which gives rise to a different
set of magnetic Bragg peaks indicative of a highly complex magnetic structure.",2208.12197v1
2022-09-20,Tuning the hysteresis loop for the anomalous Hall effect in Pt ultrathin films on $\rm{CoFe_2O_4}$ by electrolyte gating,"Pt ultrathin films on ferromagnetic insulators have been widely studied for
spintronics applications, and magnetic moments of interface Pt atoms were
considered to be ferromagnetically ordered due to a magnetic proximity effect
(MPE). An anomalous Hall effect (AHE) is usually used to examine an
out-of-plane magnetic moments of the Pt layer. To tune ferromagnetic properties
of an Pt ultrathin film, we fabricated electric double layer transistors on Pt
thin films with thicknesses of 5.9 nm and 7.0 nm on a $\rm{CoFe_2O_4}$ (CFO)
ferrimagnetic insulator. For the Pt (7.0 nm)/CFO sample, a hysteresis loop was
observed in the anomalous Hall resistivity without the gate bias, and the
coercive field was tuned by applying the gate bias. For the Pt (5.9 nm)/CFO
sample, a hysteresis loop was not observed without a gate bias, but was opened
by applying a gate bias ($V\rm{_G} =$ $\pm$3 V). This indicated that the
long-range ferromagnetic ordering of magnetic moments in the Pt film was
switched on and off by the electric field effect. The hysteresis loop was
observed up to 19.5 K for a $V\rm{_G}$ of +3 V, while the AHE was observed up
to approximately room temperature.",2209.09797v2
2022-09-28,First Principles Study of the Electronic Structure of the Ni$_2$MnIn/InAs and Ti$_2$MnIn/InSb interfaces,"We present a first-principles study of the electronic and magnetic properties
of epitaxial interfaces between the Heusler compounds Ti$_2$MnIn and Ni$_2$MnIn
and the III-V semiconductors, InSb and InAs, respectively. We use density
functional theory (DFT) with a machine-learned Hubbard $U$ correction
determined by Bayesian optimization. We evaluate these interfaces for
prospective applications in Majorana-based quantum computing and spintronics.
In both interfaces, states from the Heusler penetrate into the gap of the
semiconductor, decaying within a few atomic layers. The magnetic interactions
at the interface are weak and local in space and energy. Magnetic moments of
less than 0.1 $\mu_B$ are induced in the two atomic layers closest to the
interface. The induced spin polarization around the Fermi level of the
semiconductor also decays within a few atomic layers. The decisive factor for
the induced spin polarization around the Fermi level of the semiconductor is
the spin polarization around the Fermi level in the Heusler, rather than the
overall magnetic moment. As a result, the ferrimagnetic narrow-gap
semiconductor Ti$_2$MnIn induces a more significant spin polarization in the
InSb than the ferromagnetic metal Ni$_2$MnIn induces in the InAs. This is
explained by the position of the transition metal $d$ states in the Heusler
with respect to the Fermi level. Based on our results, these interfaces are
unlikely to be useful for Majorana devices but could be of interest for
spintronics.",2209.14101v3
2022-09-29,The importance of electronic correlations in exploring the exotic phase diagram of layered Li$_x$MnO$_2$,"Using ab initio dynamical mean-field theory we explore the electronic and
magnetic states of layered Li$_x$MnO$_2$ as a function of $x$, the state of
charge. Constructing real-space Wannier projections of Kohn-Sham orbitals based
on the low-energy subspace of Mn $3d$ states and solving a multi-impurity
problem, our approach focuses on local correlations at Mn sites. The
antiferromagnetic insulating state in LiMnO$_2$ has a moderate N\'{e}el
temperature of $T_N=296\,K$ in agreement with experimental studies. Upon
delithiation the system proceeds through a number of states: ferrimagnetic
correlated metals at $x$=0.92, 0.83; multiple charge disproportionated
ferromagnetic correlated metals with large quasiparticle weights at $x$=0.67,
0.50, 0.33; ferromagnetic metals with small quasiparticle weights at $x$=0.17,
0.08 and an antiferromagnetic insulator for the fully delithiated state,
$x=0.0$. At moderate states of charge, $x=0.67-0.33$, a mix of +3/+4 formal
oxidation states of Mn is observed, while the overall nominal oxidation of Mn
state changes from +3 in LiMnO$_2$ to +4 in MnO$_2$. In all these cases the
high-spin state emerges as the most likely state in our calculations
considering the full $d$~manifold of Mn based on the proximity of $e_g$ levels
in energy to $t_{2g}$. The quasiparticle peaks in the correlated metallic
states were attributed to polaronic states based on previous literature for
similar isoelectronic JT driven materials, arising due to non-Fermi liquid type
behaviour of the strongly correlated system.",2209.14682v3
2022-10-05,"Magnetic, structural and magnetocaloric properties of Y$_{0.9}$Gd$_{0.1}$Fe$_{2}$H$_{x}$ hydrides","At 300 K, Y$_{0.9}$Gd$_{0.1}$Fe$_{2}$H$_{x}$ hydrides crystallize
sequentially with increasing H concentration in various structures related to a
lowering of the cubic MgCu$_{2}$ type structure of the parent alloy: cubic C1,
monoclinic M1, cubic C2, monoclinic M2, cubic C3, orthorhombic O. Above 300 K,
they undergo a first-order transition at a T$_{O-D}$ temperature driven by
order-disorder of hydrogen atoms into interstitial sites. Their magnetic,
structural and magnetocaloric properties have been investigated through
magnetic measurements, and high-resolution synchrotron diffraction experiments.
The magnetization at 5 K decreases slightly from 4 to 3.8 ${\mu}_{B}$ for x = 3
to 3.9 H f.u., then with a larger slope for higher H content. A discontinuous
decrease of the magnetic transition temperature is observed: M1 and C2 hydrides
are ferrimagnetic with T$_{C}$ near 300 K, M2 hydride displays a sharp
ferromagnetic-antiferromagnetic transition at T$_{FM-AFM}$ =144 K, whereas C3
and O hydrides present only a sharp increase of the magnetization below 15 K
and a weak magnetization up to RT. Negative magnetic entropy variations
(${\Delta}$S$_{M}$) are measured near T$_{C}$ for the M1 and C2 phases, near
T$_{FM-AFM}$ for the M2 phase, whereas positive ${\Delta}$S$_{M}$ peaks due to
inverse MCE effect are found near T$_{O-D}$. A structural and magnetic phase
diagram is proposed.",2210.02262v1
2022-10-27,"Tuning of the carrier localization, magnetic and thermoelectric properties in ultrathin (LaNiO$_{3-δ}$)$_1$/(LaAlO$_{3}$)$_1$(001) superlattices by oxygen vacancies","Using a combination of density functional theory calculations with an on-site
Coulomb repulsion term (DFT+$U$) and Boltzmann transport theory within the
constant relaxation time approximation, we explore the effect of oxygen
vacancies on the electronic, magnetic, and thermoelectric properties in
ultrathin (LaNiO$_{3-\delta}$)$_1$/(LaAlO$_{3}$)$_1$(001) superlattices (SLs).
For the pristine SL, an antiferromagnetic charge-disproportionated (AFM-CD)
($d^{8}${$\underline L$}$^{2}$)$_{S=0}$($d^{8}$)$_{S=1}$ phase is stabilized,
irrespective of strain. At $\delta$ = 0.125 and 0.25, the localization of
electrons released from the oxygen defects in the NiO$_{2}$ plane triggers a
charge-disproportionation, leading to a ferrimagnetic insulator both at
$a_{\mathrm{STO}}$ (tensile strain) and $a_{\mathrm{LSAO}}$ (compressive
strain). At $\delta$ = 0.5, an insulating phase emerges with alternating
stripes of Ni$^{2+}$ (high-spin) and Ni$^{2+}$ (low-spin) and oxygen vacancies
ordered along the [110] direction (S-AFM), irrespective of strain. This results
in a robust $n$-type in-plane power factor of 24~$\mu$W/K$^2$ cm at
$a_{\mathrm{STO}}$ and 14~$\mu$W/K$^2$ cm at $a_{\mathrm{LSAO}}$ at 300~K
(assuming relaxation time $\tau = 4$~fs). Additionally, the pristine and
$\delta$ = 0.5 SLs are shown to be dynamically stable. This demonstrates the
fine tunability of electronic, magnetic, and thermoelectric properties of
ultrathin nickelate superlattices by oxygen vacancies.",2210.15501v2
2022-11-01,Laser-driven first-order spin reorientation and Verwey phase transitions in the magnetite Fe$_3$O$_4$ beyond the range of thermodynamic equilibrium,"Ultrafast photo-induced phase transitions occurring under the impact of
femtosecond laser pulses provide versatile opport unities for switching solids
between distinctly-different crystalline, electronic, and magnetic states and
thus modify their functional properties in a significant way. In this paper, we
report on the laser-induced spin reorientation and Verwey phase transitions in
a single crystalline ferrimagnetic magnetite Fe$_3$O$_4$. Using femtosecond
optical and magneto-optical pump-probe techniques, we define the range of the
initial sample temperatures and laser fluences when partialor complete
photo-induced phase transitions occur from a monoclinic insulating to a cubic
metallic state with concomitant switching of magnetic anisotropy from the
uniaxial to the cubic one. We thus reveal a connection between these phase
transitions when driven by femtosecond laser pulses.Using transient linear and
quadratic magneto-optical effects, we examine magnetization dynamics launched
the switching of the magnetic anisotropy axis. We unveil the presence of the
domains under going the laser-induced phase transitions even below the
established threshold fluence for the transitions, as well as when the material
is initially in the cubic phase. This is the manifestation of the first-order
of these both laser-induced phase transitions beyond the range of thermodynamic
equilibrium.",2211.00669v2
2022-11-04,Spin and spin current -- From fundamentals to recent progress,"Along with the progress of spin science and spintronics research, the flow of
electron spins, (i.e. spin current), has attracted interest. New phenomena and
electronic states were explained in succession using the concept of spin
current. Moreover, as many of the conventionally known spintronics phenomena
became well organized based on spin current, it has rapidly been recognized as
an essential concept in a wide range of condensed matter physics. In this
article, we focus on recent developments in the physics of spin, spin current,
and their related phenomena, where the conversion between spin angular momentum
and different forms of angular momentum plays an essential role. Starting with
an introduction to spin current, we first discuss the recent progress in
spintronic phenomena driven by spin-exchange coupling: spin pumping,
topological Hall torque, and emergent inductor. We, then, extend our discussion
to the interaction/interconversion of spins with heat, lattice vibrations, and
charge current and address recent progress and perspectives on the spin Seebeck
and Peltier effects. Next, we review the interaction between mechanical motion
and electron/nuclear spins and argue the difference between the Barnett field
and rotational Doppler effect. We show that the Barnett effect reveals the
angular momentum compensation temperature, at which the net angular momentum is
quenched in ferrimagnets.",2211.02241v4
2022-11-04,Dynamic complex opto-magnetic holography,"Computer-generated holograms with their animated, three-dimensional
appearance have long appealed to our imagination as the path towards truly
immersive displays with bi-directional natural parallax. Impressive progress in
updateable 3-D imagery has been achieved with liquid crystal modulators and
high-resolution, but quasi-static holograms are being recorded in
photosensitive materials. However, the memory requirements and computational
loads of real-time, large-area holography will be hard to tackle for several
decades to come with the current paradigm based on a matrix calculations and
bit-plane writing. Here, we experimentally demonstrate a conceptually novel,
holistic approach to serial computation and repeatable writing of
computer-generated dynamic holograms without Fourier transform, using minimal
amounts of computer memory. We use the ultrafast opto-magnetic recording of
holographic patterns in a ferrimagnetic film with femtosecond laser pulses,
driven by on-the-fly hardware computation of a single holographic point. The
intensity-threshold nature of the magnetic medium allows
sub-diffraction-limited, point-by-point toggling of arbitrarily localized
magnetic spots on the sample, according to the proposed circular detour-phase
encoding, providing complex modulation and symmetrical suppression of upper
diffractive orders and conjugated terms in holographically reconstructed 3-D
images.",2211.02741v1
2022-11-19,Mean-field ground-state phase diagram of the ${t-t^\prime}$ ionic-Hubbard chain,"Ground state (GS) phase diagram of the one dimensional repulsive Hubbard
model with both nearest neighbor ($t$) and next-nearest-neighbor ($t^{\prime}$)
hopping and a staggered potential ($\Delta$) is determined in the case of
half-filled band and zero net magnetization within the mean-field theory. The
model may be realized by cold atoms in engineered optical lattices. Connection
between the peculiarities of the GS phase diagram of the interacting system and
the topological Lifshitz transition in GS of free particle chain is discussed.
The mean-field Hamiltonian is given by six order parameters, which are
determined self-consistently. It is shown that the GS phase diagram {\em
predominantly} consists of insulating phases characterized by coexistence of
the long-range ordered modulations of the charge- (I) and antiferromagnetic
(AF) spin-density with wavelengths equal to two and/or four lattice units.
Below the Lifshitz transition, the GS phase diagram is qualitatively similar to
that of the standard (${t^{\prime}=0}$) ionic Hubbard model. After the Lifshitz
transition, charge- and spin-density modulations emerge within the sublattices
and have wavelengths equal to four lattice units. For moderate values of the
on-site repulsion the insulating phases are characterized by the presence of I
and AF modulations coexisting with ferrimagnetic spin- and charge-density
modulations within the one sublattice, or by the coexistence of I order and
additional AF spin density modulation only within the sublattice with high
ionic potential. At large repulsion the insulating phase with AF order inside
both sublattices and remaining small ionicity left between the sublattices is
realized.",2211.10543v1
2022-11-20,Sublattice-enriched tunability of bound states in second-order topological insulators and superconductors,"Bound states at sharp corners have been widely viewed as the hallmark of
two-dimensional second-order topological insulators and superconductors. In
this work, we show that the existence of sublattice degrees of freedom can
enrich the tunability of bound states on the boundary and hence lift the
constraint on their locations. We take the Kane-Mele model with
honeycomb-lattice structure to illustrate the underlying physics. With the
introduction of an in-plane exchange field to the model, we find that the
boundary Dirac mass induced by the exchange field has a sensitive dependence on
the boundary sublattice termination. We find that the sensitive sublattice
dependence can lead bound states to emerge at a specific type of boundary
defects named as sublattice domain walls if the exchange field is of
ferromagnetic nature, even in the absence of any sharp corner on the boundary.
Remarkably, this sensitive dependence of the boundary Dirac mass on the
boundary sublattice termination allows the positions of bound states to be
manipulated to any place on the boundary for an appropriately-designed sample.
With a further introduction of conventional s-wave superconductivity to the
model, we find that, no matter whether the exchange field is ferromagnetic,
antiferromagnetic, or ferrimagnetic, highly controllable Majorana zero modes
can be achieved at the sublattice domain walls. Our work reshapes the
understanding of boundary physics in second-order topological phases, and
meanwhile opens potential avenues to realize highly controllable bound states
for potential applications.",2211.10905v2
2022-11-21,General time-reversal equivariant neural network potential for magnetic materials,"This study introduces time-reversal E(3)-equivariant neural network and
SpinGNN++ framework for constructing a comprehensive interatomic potential for
magnetic systems, encompassing spin-orbit coupling and noncollinear magnetic
moments. SpinGNN++ integrates multitask spin equivariant neural network with
explicit spin-lattice terms, including Heisenberg, Dzyaloshinskii-Moriya,
Kitaev, single-ion anisotropy, and biquadratic interactions, and employs
time-reversal equivariant neural network to learn high-order spin-lattice
interactions using time-reversal E(3)-equivariant convolutions. To validate
SpinGNN++, a complex magnetic model dataset is introduced as a benchmark and
employed to demonstrate its capabilities. SpinGNN++ provides accurate
descriptions of the complex spin-lattice coupling in monolayer CrI$_3$ and
CrTe$_2$, achieving sub-meV errors. Importantly, it facilitates large-scale
parallel spin-lattice dynamics, thereby enabling the exploration of associated
properties, including the magnetic ground state and phase transition.
Remarkably, SpinGNN++ identifies a new ferrimagnetic state as the ground
magnetic state for monolayer CrTe2, thereby enriching its phase diagram and
providing deeper insights into the distinct magnetic signals observed in
various experiments.",2211.11403v3
2022-12-02,"Thermal first-order phase transitions, Ising critical points, and reentrance in the Ising-Heisenberg model on the diamond-decorated square lattice in a magnetic field","The thermal phase transitions of a spin-1/2 Ising-Heisenberg model on the
diamond-decorated square lattice in a magnetic field are investigated using a
decoration-iteration transformation and classical Monte Carlo simulations. A
generalized decoration-iteration transformation maps this model exactly onto an
effective classical Ising model on the square lattice with
temperature-dependent effective nearest-neighbor interactions and magnetic
field strength. The effective field vanishes along a ground-state phase
boundary of the original model, separating a ferrimagnetic and a quantum
monomer-dimer phase. At finite temperatures this phase boundary gives rise to
an exactly solvable surface of discontinuous (first-order) phase transitions,
which terminates in a line of Ising critical points. The existence of
discontinuous reentrant phase transitions within a narrow parameter regime is
reported and explained in terms of the low-energy excitations from both phases.
These exact results, obtained from the mapping to the zero-field effective
Ising model are corroborated by classical Monte Carlo simulations of the
effective model.",2212.01278v3
2023-01-23,Partially disordered Heisenberg antiferromagnet with short-range stripe correlations,"Zero-point quantum fluctuations of a N\'eel order can produce effective
interactions between quasi-orphan spins weakly coupled to the lattice. On the
$\sqrt{3}\times\sqrt{3}-$distorted triangular lattice, this phenomenon leads to
a correlated partially disordered phase. In this article, we use matrix product
state methods to study a similar model: the $S=1/2$ stuffed square lattice.
Tunning the exchange amplitudes we go from a square lattice plus orphan central
spins at $J'/J =0$, to the union jack lattice at $J'/J=1$, and a square lattice
including all spins at $J/J'=0$. We calculate the complete antiferromagnetic
phase diagram, dominated by ferrimagnetic and N\'eel orders, and compare with
existing results. Most importantly, we find a partially disordered phase in the
weakly frustrated regime. In this phase, the N\'eel order from the square
lattice is unaffected, while the central spins form a collective state with
exponentially decaying double striped correlations. We also study the role of
quantum fluctuations by introducing an ordering staggered magnetic field on the
square sublattice, and find that the central spins order ferromagnetically when
fluctuations from the N\'eel order are suppressed.",2301.09446v3
2023-01-24,"Ab initio Prediction of Mechanical, Electronic, Magnetic and Transport Properties of Bulk and Heterostructure of a Novel Fe-Cr based Full Heusler Chalcogenide","Using electronic structure calculations based on density functional theory,
we predict and study the structural, mechanical, electronic, magnetic and
transport properties of a new full Heusler chalcogenide, namely, Fe$_2$CrTe,
both in bulk and heterostructure form. The system shows a ferromagnetic and
half-metallic(HM) like behavior, with a very high (about 95%) spin polarization
at the Fermi level, in its cubic phase. Interestingly, under tetragonal
distortion, a clear minimum (with almost the same energy as the cubic phase)
has also been found, at a c/a value of 1.26, which, however, shows a
ferrimagnetic and fully metallic nature. The compound has been found to be
dynamically stable in both the phases against the lattice vibration. The
elastic properties indicate that the compound is mechanically stable in both
the phases, following the stability criteria of the cubic and tetragonal
phases. The elastic parameters unveil the mechanically anisotropic and ductile
nature of the alloy system. Due to the HM-like behavior of the cubic phase and
keeping in mind the practical aspects, we probe the effect of strain as well as
substrate on various physical properties of this alloy. Transmission profile of
the Fe$_2$CrTe/MgO/Fe$_2$CrTe heterojunction has been calculated to probe it as
a magnetic tunneling junction (MTJ) material in both the cubic and tetragonal
phases. Considerably large tunneling magnetoresistance ratio (TMR) of 1000% is
observed for the tetragonal phase, which is found to be one order of magnitude
larger than that of the cubic phase.",2301.09843v1
2023-02-02,Leveraging symmetry for an accurate spin-orbit torques characterization in ferrimagnetic insulators,"Spin-orbit torques (SOTs) have emerged as an efficient means to electrically
control the magnetization in ferromagnetic heterostructures. Lately, an
increasing attention has been devoted to SOTs in heavy metal (HM)/magnetic
insulator (MI) bilayers owing to their tunable magnetic properties and
insulating nature. Quantitative characterization of SOTs in HM/MI
heterostructures are, thus, vital for fundamental understanding of charge-spin
interrelations and designing novel devices. However, the accurate determination
of SOTs in MIs have been limited so far due to small electrical signal outputs
and dominant spurious thermoelectric effects caused by Joule heating. Here, we
report a simple methodology based on harmonic Hall voltage detection and
macrospin simulations to accurately quantify the damping-like and field-like
SOTs, and thermoelectric contributions separately in MI-based systems.
Experiments on the archetypical Bi-doped YIG/Pt heterostructure using the
developed method yield precise values for the field-like and damping-like SOTs,
reaching -0.14 and -0.15 mT per 1.7x$10^{ 11}$ A/$m^2$, respectively. We
further reveal that current-induced Joule heating changes the spin transparency
at the interface, reducing the spin Hall magnetoresistance and damping-like
SOT, simultaneously. These results and the devised method can be beneficial for
fundamental understanding of SOTs in MI-based heterostructures and designing
new devices where accurate knowledge of SOTs is necessary.",2302.01141v2
2023-02-07,Pressure-induced magnetic properties of quasi-2D Cr2Si2Te6 and Mn3Si2Te6,"Recently, the pressure has been used as external stimuli to induce structural
and magnetic phase transitions in many layered quantum materials whose layers
are linked by van der Waals forces. Such materials with weakly held layers
allow relatively easy manipulation of the superexchange mechanism and lead to
novel magnetic behavior. Using the hydrostatic pressure as a disorderless means
to manipulate the interlayer coupling, we applied pressure on two quasi-2D
sister compounds, namely, Cr2Si2Te6 (CST) and Mn3Si2Te6 (MST), up to ~1 GPa.
Magnetic property measurements with the application of pressure revealed that
the ferromagnetic transition temperature decreases in CST while the opposite
trend occurs for the ferrimagnet MST. In MST, the magnetization decreases with
the increase in the pressure, and such trend is not clearly noticed in CST,
within the pressure range studied. Theoretical calculations showed the overall
pressure effect on layer separation, bond angle, and exchange coupling,
strongly influencing the change in subsequent magnetic characteristics.
Exchange coupling in Mn3Si2Te6 is strongly frustrated and the first nearest
neighbor interaction is the most dominant of the components with the strongest
pressure dependence. Whereas, in Cr2Si2Te6, the exchange coupling parameters
exhibit very little dependence on the pressure. This combined experimental and
theoretical work has the potential to expand to other relevant quantum
materials.",2302.03170v1
2023-02-11,Multi-k magnetic structure and large anomalous Hall effect in candidate magnetic Weyl semimetal NdAlGe,"The magnetic structure, magnetoresistance, and Hall effect of
non-centrosymmetric magnetic semimetal NdAlGe are investigated revealing an
unusual magnetic state and anomalous transport properties that are associated
with the electronic structure of this non-centrosymmetric compound. The
magnetization and magnetoresistance measurements are both highly anisotropic
and indicate an Ising-like magnetic system. The magnetic structure is complex
in that it involves three magnetic ordering vectors including an incommensurate
spin density wave and commensurate ferrimagnetic state in zero field. We have
discovered a large anomalous Hall conductivity that reaches = 430
{\Omega}-1cm-1 implying that it originates from an intrinsic Berry curvature
effect stemming from Weyl nodes found in the electronic structure. These
electronic structure calculations indicate the presence of nested Fermi surface
pockets with nesting wave vectors similar to the measured magnetic ordering
wavevector and the presence of Weyl nodes in proximity to the Fermi surface. We
associate the incommensurate magnetic structure with the large anomalous Hall
response to be the result of the combination of Fermi surface nesting and the
Berry curvature associated with Weyl nodes.",2302.05596v2
2023-03-01,"Interplay between magnetism and short-range order in medium- and high-entropy alloys: CrCoNi, CrFeCoNi, and CrMnFeCoNi","The impact of magnetism on predicted atomic short-range order in three
medium- and high-entropy alloys is studied using a first-principles,
all-electron, Landau-type linear response theory, coupled with lattice-based
atomistic modelling. We perform two sets of linear-response calculations: one
in which the paramagnetic state is modelled within the disordered local moment
picture, and one in which systems are modelled in a magnetically ordered state,
which is ferrimagnetic for the alloys considered in this work. We show that the
treatment of magnetism can have significant impact both on the predicted
temperature of atomic ordering and also the nature of atomic order itself. In
CrCoNi, we find that the nature of atomic order changes from being
$\mathrm{L}1_2$-like when modelled in the paramagnetic state to MoPt$_2$-like
when modelled assuming the system has magnetically ordered. In CrFeCoNi, atomic
correlations between Fe and the other elements present are dramatically
strengthened when we switch from treating the system as magnetically disordered
to magnetically ordered. Our results show it is necessary to consider the
magnetic state when modelling multicomponent alloys containing mid- to
late-$3d$ elements. Further, we suggest that there may be high-entropy alloy
compositions containing $3d$ transition metals that will exhibit specific
atomic short-range order when thermally treated in an applied magnetic field.
This has the potential to provide a route for tuning physical and mechanical
properties in this class of materials.",2303.00641v2
2023-03-12,Competing Magnetic Interactions and Field-Induced Metamagnetic Transition in Highly Crystalline Phase-Tunable Iron Oxide Nanorods,"The inherent existence of multi phases in iron oxide nanostructures
highlights the significance of them being investigated deliberately to
understand and possibly control the phases. Here, the effects of annealing at
250 0C with a variable duration on the bulk magnetic and structural properties
of high aspect ratio bi-phase iron oxide nanorods with ferrimagnetic Fe3O4 and
antiferromagnetic alpha-Fe2O3 is explored. Increasing annealing time under a
free flow of oxygen enhanced the alpha-Fe2O3 volume fraction, and improved the
crystallinity of the Fe3O4 phase, identified in changes in the magnetization as
a function of annealing time. A critical annealing time of approximately 3
hours maximized the presence of both phases, as observed via an enhancement in
the magnetization and an interfacial pinning effect. This is attributed to
disordered spins separating the magnetically distinct phases which tend to
align with the application of a magnetic field at high temperatures. The
increased antiferromagnetic phase can be distinguished due to the field-induced
metamagnetic transitions observed in structures annealed for more than 3 hours
and was especially prominent in the 9-hour annealed sample. Our controlled
study in determining the changes in volume fractions with annealing time will
enable precise control over phase tunability in iron oxide nanorods, allowing
custom-made phase volume fractions in different applications ranging from
spintronics to biomedical applications.",2303.06684v1
2023-03-15,Ultrafast Opto-magnetic Effects in the Extreme Ultraviolet Spectral Range,"Coherent light-matter interactions mediated by opto-magnetic phenomena like
the inverse Faraday effect (IFE) are expected to provide a non-thermal pathway
for ultrafast manipulation of magnetism on timescales as short as the
excitation pulse itself. As the IFE scales with the spin-orbit coupling
strength of the involved electronic states, photo-exciting the strongly
spin-orbit coupled core-level electrons in magnetic materials appears as an
appealing method to transiently generate large opto-magnetic moments. Here, we
investigate this scenario in a ferrimagnetic GdFeCo alloy by using intense and
circularly polarized pulses of extreme ultraviolet radiation. Our results
reveal ultrafast and strong helicity-dependent magnetic effects which are in
line with the characteristic fingerprints of an IFE, corroborated by ab initio
opto-magnetic IFE theory and atomistic spin dynamics simulations.",2303.08564v1
2023-03-20,The Classical Heisenberg Model on the Centred Pyrochlore Lattice,"The centred pyrochlore lattice is a novel geometrically frustrated lattice,
realized in the metal-organic framework Mn(ta)$_2$ (arXiv:2203.08780) where the
basic unit of spins is a five site centred tetrahedron. Here, we present an
in-depth theoretical study of the $J_1-J_2$ classical Heisenberg model on this
lattice, using a combination of mean-field analytical methods and Monte Carlo
simulations. We find a rich phase diagram with low temperature states
exhibiting ferrimagnetic order, partial ordering, and a highly degenerate spin
liquid with distinct regimes of low temperature correlations. We discuss in
detail how the regime displaying broadened pinch points in its spin structure
factor is consistent with an effective description in terms of a fluid of
interacting charges. We also show how this picture holds in two dimensions on
the analogous centred kagome lattice and elucidate the connection to the
physics of thin films in ($d+1$) dimensions. Furthermore, we show that a
Coulomb phase can be stabilized on the centred pyrochlore lattice by the
addition of further neighbour couplings. This demonstrates the centred
pyrochlore lattice is an experimentally relevant geometry which naturally hosts
emergent gauge fields in the presence of charges at low energies.",2303.11010v3
2023-03-23,Multiple magnetic transitions and complex magnetic structures in Fe$_2$SiSe$_4$ with the sawtooth lattice,"The sawtooth lattice shares some structural similarities with the kagome
lattice and may attract renewed research interest. Here, we report a
comprehensive study on the physical properties of Fe$_2$SiSe$_4$, an unexplored
member in the olivine chalcogenides with the sawtooth lattice of Fe. Our
results show that Fe$_2$SiSe$_4$ is a magnetic semiconductor with band gap of
0.66~eV. It first undergoes an antiferromagnetic transition at T$_{m1}$=110~K,
then an ferrimagnetic-like one at T$_{m2}$=50~K and finally a magnetic
transition at T$_{m3}$=25~K which is likely driven by the thermal populations
of spin-orbit manifold on the Fe site. Neutron diffraction analysis reveals a
non-collinear antiferromagnetic structure with propagation vector
$\mathbf{q_1}$=(0,0,0) at T$_{m2}$<T<T$_{m1}$. Interestingly, below T$_{m2}$,
an additional antiferromagnetic structure with $\mathbf{q_2}$=(0,0.5,0) appears
and Fe$_2$SiSe$_4$ exhibits a complex double-$\mathbf{q}$ magnetic structure
which has never been observed in sawtooth olivines. Density functional theory
calculations suggest this complex noncollinear magnetic structure may originate
from the competing antiferromagnetic interactions for both intra- and
inter-chain in the sawtooth lattice. Furthermore, band structural calculations
show that Fe$_2$SiSe$_4$ has quasi-flat band features near the valence and
conduction bands. Based on the above results, we propose Fe$_2$SiSe$_4$ as a
new material platform to condensed matter researches.",2303.13224v1
2023-04-18,Universal phenomenology at critical exceptional points of nonequilibrium $O(N)$ models,"In thermal equilibrium the dynamics of phase transitions is largely
controlled by fluctuation-dissipation relations: On the one hand, friction
suppresses fluctuations, while on the other hand the thermal noise is
proportional to friction constants. Out of equilibrium, this balance dissolves
and one can have situations where friction vanishes due to antidamping in the
presence of a finite noise level. We study a wide class of $O(N)$ field
theories where this situation is realized at a phase transition, which we
identify as a critical exceptional point. In the ordered phase, antidamping
induces a continuous limit cycle rotation of the order parameter with an
enhanced number of $2N-3$ Goldstone modes. Close to the critical exceptional
point, however, fluctuations diverge so strongly due to the suppression of
friction that in dimensions $d<4$ they universally either destroy a preexisting
static order, or give rise to a fluctuation-induced first order transition.
This is demonstrated within a non-perturbative approach based on
Dyson-Schwinger equations for $N=2$, and a generalization for arbitrary $N$,
which can be solved exactly in the long wavelength limit. We show that in order
to realize this physics it is not necessary to drive a system far out of
equilibrium: Using the peculiar protection of Goldstone modes, the transition
from an $xy$ magnet to a ferrimagnet is governed by an exceptional critical
point once weakly perturbed away from thermal equilibrium.",2304.09207v1
2023-04-26,Tunable Magnetic Properties in Sr$_2$FeReO$_6$ Double-Perovskite,"Double-perovskite oxides have attracted recent attention due to their
attractive functionalities and application potential. In this paper, we
demonstrate the effect of dual controls, i.e., the deposition pressure of
oxygen (P$_O2$) and lattice mismatch ($\epsilon$), on tuning magnetic
properties in epitaxial double-perovskite Sr$_2$FeReO$_6$ films. In a
nearly-lattice-matched Sr$_2$FeReO$_6$/SrTiO$_3$ film, the
ferrimagnetic-to-paramagnetic phase transition occurs when P$_O2$ is reduced to
30 mTorr, probably due to the formation of Re$^{4+}$ ions that replace the
stoichiometric Re$^{5+}$ to cause disorders of $B$-site ions. On the other
hand, a large compressive strain or tensile strain shifts this critical P$_O2$
to below 1 mTorr or above 40 mTorr, respectively. The observations could be
attributed to the modulation of $B$-site ordering by epitaxial strain through
affecting elemental valence. Our results provide a feasible way to expand the
functional tunability of magnetic double-perovskite oxides that hold great
promise for spintronic devices.",2304.13288v1
2023-05-08,Gravitational anomaly in the ferrimagnetic topological Weyl semimetal NdAlSi,"Quantum anomalies are the breakdowns of classical conservation laws that
occur in quantum-field theory description of a physical system. They appear in
relativistic field theories of chiral fermions and are expected to lead to
anomalous transport properties in Weyl semimetals. This includes a chiral
anomaly, which is a violation of the chiral current conservation that takes
place when a Weyl semimetal is subjected to parallel electric and magnetic
fields. A charge pumping between Weyl points of opposite chirality causes the
chiral magnetic effect that has been extensively studied with electrical
transport. On the other hand, if the thermal gradient, instead of the
electrical field, is applied along the magnetic field, then as a consequence of
the gravitational (also called the thermal chiral) anomaly an energy pumping
occurs within a pair of Weyl cones. As a result, this is expected to generate
anomalous heat current contributing to the thermal conductivity. We report an
increase of both the magneto-electric and magneto-thermal conductivities in
quasi-classical regime of the magnetic Weyl semimetal NdAlSi. Our work also
shows that the anomalous electric and heat currents, which occur due to the
chiral magnetic effect and gravitational anomalies respectively, are still
linked by a 170 years old relation called the Wiedemann-Franz law.",2305.04650v2
2023-05-16,Measurement of the Dzyaloshinskii-Moriya Interaction in Mn4N Films that Host Skyrmions,"Mn4N thin film is one of the potential magnetic mediums for spintronic
devices due to its ferrimagnetism with low magnetization, large perpendicular
magnetic anisotropy (PMA), thermal stability, and large domain wall velocity. A
recent experiment confirmed the existence of tunable magnetic skyrmions in
MgO/Mn4N/CuxPt1-x(x=0,0.5,0.9,0.95), and density functional theory (DFT)
calculation provided a large theoretical value of the interfacial
Dzyaloshinskii-Moriya Interaction (iDMI) of Mn4N/Pt, which is consistent with
the predicted chemical trend of DMI in transition metal/Pt films. So far,
measured DMI has not been reported in Mn4N which is needed in order to support
the predicted large DMI value. This paper reports the average DMI of
MgO/Mn4N(17nm)/CuxPt1-x(3nm), extracted from the anomalous Hall effect with
various tilted angles, based on magnetic droplet theory with DMI effects. The
DMI decreases from 0.267 mJ/m2 to 0.011 mJ/m2 with non-linear tendencies as Cu
concentration in the CuxPt1-x capping layer increases from 0 to 1,
demonstrating the control of DMI through CuxPt1-x capping layer. Furthermore, a
solid solution model is developed, based on X-ray photoelectron spectroscopy
(XPS) compositional depth profile, to analyze the possible effects on DMI from
the mixing layers at the surface of Mn4N. After taking into account the mixing
layers, the large DMI in Mn4N film with Pt capping is consistent with the
predicted DMI.",2305.09087v1
2023-05-23,Spin and Charge Fluctuation Induced Pairing in ABCB Tetralayer Graphene,"Motivated by the recent experimental realization of ABCB stacked tetralayer
graphene [Wirth et al., ACS Nano 16, 16617 (2022)], we study correlated
phenomena in moir\'e-less graphene tetralayers for realistic interaction
profiles using an orbital resolved random phase approximation approach. We
demonstrate that magnetic fluctuations originating from local interactions are
crucial close to the van Hove singularities on the electron- and hole-doped
side promoting layer selective ferrimagnetic states. Spin fluctuations around
these magnetic states enhance unconventional spin-triplet, valley-singlet
superconductivity with $f$-wave symmetry due to intervalley scattering. Charge
fluctuations arising from long range Coulomb interactions promote doubly
degenerate p-wave superconductivity close to the van Hove singularities. At the
conduction band edge of ABCB graphene, we find that both spin and charge
fluctuations drive $f$-wave superconductivity. Our analysis suggests a strong
competition between superconducting states emerging from long- and short-ranged
Coulomb interactions and thus stresses the importance of microscopically
derived interaction profiles to make reliable predictions for the origin of
superconductivity in graphene based heterostructures.",2305.14438v2
2023-06-19,The 3d and 5d electronic structures and orbital hybridization in Ba- and Ca-doped La2CoIrO6 double perovskite,"Here we present a detailed investigation of the Co and Ir local electronic
structures in La1.5A0.5CoIrO6 (A = Ba, Ca) compounds in order to unravel the
orbital hybridization mechanism in these CoIr-based double perovskites. Our
results of x-ray powder diffraction, ac and dc magnetization, Co and Ir
L2,3-edges and Co K-edge x-ray absorption spectroscopy and x-ray magnetic
circular dichroism suggest a competition between magnetic interactions. A
dominant antiferromagnetic coupling is found to be responsible for the
ferrimagnetic behavior observed for A = Ca below approximately 96 K, the
competing magnetic phases and the cationic disorder in this compound giving
rise to a spin-glass state at low temperatures. For the A = Ba, on the other
hand, there is no evidence of long range order down to its spin-glass
transition temperature. The remarkably different magnetic properties observed
between these two compounds is discussed in terms of the structural distortion
that alters the strength of the Co - Ir couplings, with a relevant role played
by the Co 3d eg - Ir 5d j = 1/2 hybridization.",2306.10883v1
2023-06-22,New insight into tuning magnetic phases of RMn6Sn6 kagome metals,"Kagome metals with magnetic order offer the possibility of tuning topological
electronic states via external control parameters such as temperature or
magnetic field. ErMn$_6$Sn$_6$ (Er$166$) is a member of a group of $R166$,
$R=$~rare earth, compounds hosting ferromagnetic Mn kagome nets whose magnetic
moment direction and layer-to-layer magnetic correlations are strongly
influenced by coupling to $R$ magnetic moments in neighboring triangular
layers. Here, we use neutron diffraction and magnetization data to examine the
temperature-driven transition in Er$166$ from a planar-ferrimagnetic to
distorted-triple-spiral magnetic order. These data inform mean-field
calculations which highlight the fragile, tunable nature of the magnetism
caused by competing Mn-Mn and Mn-Er interlayer magnetic exchange couplings and
Mn and Er magnetic anisotropies. This competition results in the near
degeneracy of a variety of collinear, non-collinear, and non-coplanar magnetic
phases which we show are readily selected and adjusted via changing temperature
or magnetic field. Thermal fluctuations of the Er moment direction provide the
key to this tunability.",2306.13206v2
2023-06-26,"Spin-flop quasi metamagnetic, anisotropic magnetic, and electrical transport behavior of Ho substituted kagome magnet ErMn$_6$Sn$_6$","We report on the magnetic and electrical properties of a (Mn$_3$Sn)$_2$
triangular network kagome structured high quality Ho substituted ErMn$_6$Sn$_6$
single-crystal sample by magneto-transport measurements.
Er$_{0.5}$Ho$_{0.5}$Mn$_6$Sn$_6$ orders antiferromagnetically at N\'{e}el
temperature $T_\mathrm{N} \sim$ 350 K followed by a ferrimagnetic (FiM)
transition at $T_\mathrm{C} \sim$ 114 K and spin-orientation transition at
$T_\mathrm{t} \sim$ 20 K. The field-manifestations of these magnetic phases in
the \textit{ab}-basal plane and along the \textit{c}-axis are illustrated
through temperature-field \textit{T-H} phase diagrams. In
\textit{H}$\parallel$\textit{c}, narrow hysteresis between spin reorientation
and field-induced FiM phases below $T_\mathrm{t}$, enhanced/strengthened FiM
phase below $T_\mathrm{C}$ and stemming of FiM phase out of strongly coexisting
AFM and FiM phases below $T_\mathrm{N}$ through a non-meta-magnetic transition
are confirmed to arise from strong R-Mn sublattices interaction. In contrast,
\textit{H}$\parallel$\textit{ab}-plane, between $T_\mathrm{N}$ and
$T_\mathrm{C}$, individually contributing R-Mn sublattices with weak
antiferromagnetic interactions undergo a field-induced spin-flop
quasi-metamagnetic transition to FiM state. The temperature dependent
electrical resistivity suggests metallic nature with Fermi liquid behavior at
low temperatures. Essentially, the current study stimulates interest to
investigate the magnetic and electrical properties of mixed rare-earth layered
kagome magnetic metals for possible novel and exotic behavior.",2306.14417v1
2023-08-22,Magnon-mediated qubit coupling determined via dissipation measurements,"Controlled interaction between localized and delocalized solid-state spin
systems offers a compelling platform for on-chip quantum information processing
with quantum spintronics. Hybrid quantum systems (HQSs) of localized
nitrogen-vacancy (NV) centers in diamond and delocalized magnon modes in
ferrimagnets-systems with naturally commensurate energies-have recently
attracted significant attention, especially for interconnecting isolated spin
qubits at length-scales far beyond those set by the dipolar coupling. However,
despite extensive theoretical efforts, there is a lack of experimental
characterization of the magnon-mediated interaction between NV centers, which
is necessary to develop such hybrid quantum architectures. Here, we
experimentally determine the magnon-mediated NV-NV coupling from the
magnon-induced self-energy of NV centers. Our results are quantitatively
consistent with a model in which the NV center is coupled to magnons by dipolar
interactions. This work provides a versatile tool to characterize HQSs in the
absence of strong coupling, informing future efforts to engineer entangled
solid-state systems.",2308.11710v1
2023-09-12,Current-sensitive Hall effect in a chiral-orbital-current state,"Chiral orbital currents (COC) underpin a novel colossal magnetoresistance
(CMR) in ferrimagnetic Mn3Si2Te6 [1]. Here we report the Hall effect in the COC
state which exhibits the following unprecedented features: (1) A sharp,
current-sensitive peak in the magnetic field dependence of the Hall
resistivity; (2) An unusually large Hall angle reaching up to 0.15 (comparable
to the highest values yet reported); and (3) A current-sensitive scaling
relation between the Hall conductivity sigma_xy and the longitudinal
conductivity sigma_xx, namely, sigma_xy ~ sigma_xx^alpha with alpha ranging
between 3 and 5, which is both sensitive to external current and exceptionally
large compared to alpha < 2 typical of most solids. These anomalies point to a
giant, current-sensitive Hall effect that is unique to the COC state. We argue
that a magnetic field induced by the fully developed COC combines with the
applied magnetic field to exert the greatly enhanced transverse force on charge
carriers, which dictates the novel Hall responses. The COC Hall effect is
unique, as it is generated and controlled via the interaction between intrinsic
COC and applied external currents, which leads to novel transport phenomena of
fundamental and technological significance and requires new physics for
explanation.",2309.06610v1
2023-09-18,Low-temperature hysteresis broadening emerging from domain-wall creep dynamics in a two-phase competing system,"Hysteretic behaviour accompanies any first-order phase transition, forming a
basis for many applications. However, its quantitative understanding remains
challenging, and even a qualitative understanding of pronounced hysteresis
broadening at low temperature, which is often observed in
magnetic-field-induced first-order phase transition materials, is unclear.
Here, we show that such pronounced hysteresis broadening emerges if the
phase-front velocity during the first-order phase transition exhibits an
activated behaviour as a function of both temperature and magnetic field. This
is demonstrated by using real-space magnetic imaging techniques, for the
magnetic-field-induced first-order phase transition between antiferromagnetic
and ferrimagnetic phases in (Fe$_{0.95}$Zn$_{0.05}$)$_{2}$Mo$_{3}$O$_{8}$. When
combined with the Kolmogorov-Avrami-Ishibashi model, the observed activated
temperature- and field-dependences of the growth velocity of the emerging
antiferromagnetic domain quantitatively reproduce the pronounced hysteresis
broadening. Furthermore, the same approach also reproduces the field-sweep-rate
dependence of the transition field observed in the experiment. Our findings
thus provide a quantitative and comprehensive understanding of pronounced
hysteresis broadening from the microscopic perspective of domain growth.",2309.10213v1
2023-09-20,Effects of disorder on the magnetic properties of the Heusler alloy V$_{2}$FeAl,"Magnetic properties of multicomponent alloys depend sensitively on the degree
of atomic order on the different crystallographic sites. In this work we
demonstrate the magnetic contrast between bulk and thin-film samples of the
Heusler alloy V$_{2}$FeAl. Arc-melted bulk ingots show practically no site
preference of the elements (A2 structure), whereas magnetron-sputtered
thin-film samples display a higher degree of atomic ordering with a tendency
towards XA-type order. Electronic structure calculations favour ferrimagnetic
XA-type ordering, and the effect of different pairwise atomic disorder on the
element specific and net magnetic moments are evaluated to reproduce
experimental observations. XA-type thin-films with iron moment of 1.24
$\mu_{\mathrm{B}}$ determined by X-ray magnetic circular dichroism are in
agreement with calculation, but the measured net moment of 1.0
$\mu_{\mathrm{B}}$ per formula unit and average vanadium moment are smaller
than expected from calculations. The measured Curie temperature is
approximately 500 K. Films with a higher degree of disorder have a
T$_{\mathrm{C}}$ close to 300 K with a net moment of 0.1 $\mu_{\mathrm{B}}$ at
low temperature. The large calculated vanadium moments are destroyed by partial
disorder on $4d$ vanadium sites. By contrast, the arc-melted and annealed bulk
alloy with a fully-disordered A2 structure shows no spontaneous magnetization;
it is a Pauli paramagnet with dimensionless susceptibility
$\chi_{\mathrm{v}}=-2.95\times10^{-4}$.",2309.11480v1
2023-10-23,Microscopic theory of spin Seebeck effect in antiferromagnets,"We develop a microscopic theory for the spin Seebeck effect (SSE) in N\'eel
and canted phases of antiferromagnetic insulators. We calculate the DC spin
current tunneling from the antiferromagnet to an attached metal, incorporating
the spin-wave theory and the non-equilibrium Green's function approach. Our
result shows a sign change of the spin current at the spin-flop phase
transition between N\'eel and canted phases, which is in agreement with a
recent experiment for the SSE of $\rm Cr_2O_3$ in a semi-quantitative level.
The sign change can be interpreted from the argument based on the density of
states of up- and down-spin magnons, which is related to the polarized-neutron
scattering spectra. The theory also demonstrates that the spin current in the
N\'eel phase is governed by the magnon correlation, while that in the canted
phase consists of two parts: Contributions from not only the magnon dynamics
but also the static transverse magnetization. This result leads to a prediction
that at sufficiently low temperatures, the spin current non-monotonically
changes as a function of magnetic field in the canted phase. Towards a more
unified understanding of the SSE in antiferromagnets, we further discuss some
missing links of theories of SSE: Interface properties, effects of the
transverse spin moment in the canted phase, the spin-orbit coupling in the
metal, etc. Finally, we compare the SSE of antiferromagnets with those of
different magnetic phases such as ferromagnets, ferrimagnets, an
one-dimensional spin liquid, a spin-nematic liquid, and a spin-Peierls
(dimerized) phase.",2310.15292v2
2023-10-24,Nanoscale transient polarization gratings,"We present the generation of transient polarization gratings at the
nanoscale, achieved using a tailored accelerator configuration of the FERMI
free electron laser. We demonstrate the capabilities of such a transient
polarization grating by comparing its induced dynamics with the ones triggered
by a more conventional intensity grating on a thin film ferrimagnetic alloy.
While the signal of the intensity grating is dominated by the thermoelastic
response of the system, such a contribution is suppressed in the case of the
polarization grating. This exposes helicity-dependent magnetization dynamics
that have so-far remained hidden under the large thermally driven response. We
anticipate nanoscale transient polarization gratings to become useful for the
study of any physical, chemical and biological systems possessing chiral
symmetry.",2310.15734v1
2023-11-02,Transient grating spectroscopy on a DyCo$_5$ thin film with femtosecond extreme ultraviolet pulses,"Surface acoustic waves (SAWs) are excited by femtosecond extreme ultraviolet
(EUV) transient gratings (TGs) in a room-temperature ferrimagnetic DyCo$_5$
alloy. TGs are generated by crossing a pair of EUV pulses from a free electron
laser (FEL) with the wavelength of 20.8\,nm matching the Co $M$-edge, resulting
in a SAW wavelength of $\Lambda=44$\,nm. Using the pump-probe transient grating
scheme in a reflection geometry the excited SAWs could be followed in the time
range of -10 to 100\,ps in the thin film. Coherent generation of TGs by
ultrafast EUV pulses allows to excite SAW in any material and to investigate
their couplings to other dynamics such as spin waves and orbital dynamics. In
contrast, we encountered challenges in detecting electronic and magnetic
signals, potentially due to the dominance of the larger SAW signal and the
weakened reflection signal from underlying layers. A potential solution for the
latter challenge involves employing soft X-ray probes, albeit introducing
additional complexities associated with the required grazing incidence
geometry.",2311.01399v2
2023-11-16,Ultrafast all-optical toggle writing of magnetic bits without relying on heat,"While in accordance with Curie's principle, one would intuitively expect that
symmetry of the cause has to be found in the symmetry of the effect, ultrafast
excitation of matter is able to violate this principle. For instance, it is
believed that heating alone, obviously not having the symmetry of a magnetic
field, cannot result in a deterministic reversal of magnetization. However, if
the heating is induced by a femtosecond laser pulse and thus ultrafast, it does
facilitate toggle switching of magnetization between stable bit-states without
any magnetic field at all. Here we show that the regime of ultrafast toggle
switching can be also realized via a mechanism without relying on any heat. The
obvious mismatch between symmetries of the cause and the response can thus be
seen as a violation of Curie's principle. In particular, ultrafast laser
excitation of iron-garnet with linearly polarized light modifies magnetic
anisotropy and thus causes toggling magnetization between two stable bit
states. In contrast to the laser-heat-induced magnetization reversal, this new
regime of 'cold' toggle switching can be observed in ferrimagnets without the
compensation point and in an exceptionally broad temperature range. The control
of magnetic anisotropy required for the toggle switching is accompanied by
lower dissipations, than in the mechanism of laser-induced-heating, but the
dissipations and the switching-time are shown to be competing parameters.",2311.10173v2
2023-11-22,Effects of magnetic fields and orbital angular momentum on excitonic condensation in two-orbital Hubbard model,"We investigate the magnetic-field effects on a two-orbital Hubbard model that
describes multiple spin states. Cobalt oxides have been investigated as
materials possessing spin-state degrees of freedom due to the interplay between
the Hund coupling interaction and crystalline field effect. In the competing
region, quantum hybridizations between distinct spin states are expected to
emerge, corresponding to excitonic condensation. Applied magnetic fields could
also induce such a competition. To understand magnetic-field effects on
excitonic condensation in multi-orbital systems, it is crucial to account for
contributions from both spin and orbital degrees of freedom to magnetic
properties. Here, we study field-induced phenomena in the two-orbital Hubbard
model by focusing on the role of the orbital angular momentum. We
comprehensively analyze this model on a square lattice employing the
Hartree-Fock approximation. Omitting contributions from the orbital moment, we
find that an applied magnetic field gives rise to two excitonic phases, besides
the spin-state ordered phase, between the nonmagnetic low-spin and
spin-polarized high-spin phases. One of these excitonic phases manifests a
staggered-type spin-state order, interpreted as an excitonic supersolid state.
Conversely, the other phase is not accompanied by it and exhibits only a spin
polarization due to the applied magnetic field. When spin-orbit coupling is
present, this phase displays a ferrimagnetic spin alignment attributed to spin
anisotropy. Our analysis also reveals that incorporating the contribution of
the orbital magnetic moment to the Zeeman term significantly alters the overall
structure of the phase diagram. Notably, the orbital magnetization destabilizes
the excitonic phase in contrast to scenarios without this contribution. We also
discuss the relevance of our findings to real materials, such as cobalt oxides.",2311.13191v1
2023-12-01,Hydrogen-induced switching of perpendicular magnetic anisotropy in amorphous ferrimagnetic thin films,"Unraveling the mechanisms responsible for perpendicular magnetic anisotropy
(PMA) in amorphous rare earth-transition metal alloys has proven challenging,
primarily due to the intrinsic complexity of the amorphous structure. Here, we
investigated the atomic origin of PMA by applying an approach of voltage-driven
hydrogen insertion in interstitial sites, which serve as a perturbation and
probe in local atomic structure. After hydrogen charging, PMA in amorphous TbCo
thin films diminished and switched to in-plane anisotropy, accompanied by
distinct magnetic domain structures. By analyzing the mechanism behind the
anisotropy switching, we unveiled the decisive role of Tb-Co/Tb-Tb bonding in
shaping the magnetic anisotropy using both angle-dependent X-ray magnetic
dichroism and ab initio calculations. Hydrogen insertion induced a
reorientation of the local anisotropy axis, initially along the Tb-Co bonding
direction, due to the distortion of crystal field around Tb. Our approach not
only shows the atomic origin of Tb-Co bonding in inducing PMA, but also enables
the voltage-driven tailoring of magnetic anisotropy in amorphous alloys.",2312.00643v1
2023-12-02,Mössbauer spectroscopy study of the magnetostructural and spin-state transitions in the breathing pyrochlore LiFeCr$_{4}$O$_{8}$,"We report on investigations of the complex magnetostructural and spin-state
transitions in the breathing pyrochlore LiFeCr$_{4}$O$_{8}$ by means of
magnetization, M\""ossbauer spectroscopy, and density functional theory (DFT)
calculations. Three transitions corresponding to the ferrimagnetic transition
at $T_N\sim94$ K, the spin-gap transition at $T_{SG}\sim50$ K, and the
magnetostructural transition at $T_{MS}\sim19$ K were observed from the
$\chi$(T) curve, whereas only $T_N$ and $T_{MS}$ were evidenced for the Fe site
from our M\""ossbauer measurements, suggesting that the spin-gap transition is
absent at the Fe site. This indicates that the spin-gap transition is an effect
of the breathing Cr$_4$ lattice, in agreement with our DFT calculations from
which we see nearly decoupled electronic states for the FeO$_4$ and CrO$_6$
units. From the temperature dependence of the hyperfine magnetic field we also
observed a spin-state transition for the Fe spins at $T_{MS}$ consistent with
earlier neutron diffraction measurements. These local characteristics are
believed to be important for a complete understanding of the complex
magnetostructural coupling effects observed in similar systems.",2312.00996v1
2024-01-17,Grayscale control of local magnetic properties with direct-write laser annealing,"Across the fields of magnetism, microelectronics, optics, and others,
engineered local variations in physical properties can yield groundbreaking
functionalities that play a crucial role in enabling future technologies.
Beyond binary modifications, 1D lateral gradients in material properties
(achieved by gradients in thickness, stoichiometry, temperature, or strain)
give rise to a plethora of new effects in thin film magnetic systems. However,
extending such gradient-induced behaviors to 2D is challenging to realize with
existing methods, which are plagued by slow processing speeds, dose
instabilities, or limitation to variation along one dimension. Here, we show
for the first time how commonplace direct-write laser exposure techniques,
initially developed for grayscale patterning of photoresist surfaces, can be
repurposed to perform grayscale direct-write laser annealing. With this
technique, we demonstrate the ease with which two-dimensional, continuous
variations in magnetic properties can be created at the mesoscopic scale in
numerous application-relevant materials, including ferromagnetic,
ferrimagnetic, and synthetic antiferromagnetic thin-film systems. The speed,
versatility, and new possibilities to create complex magnetic energy landscapes
offered by direct-write laser annealing opens the door to the lateral
modification of the magnetic, electronic, and structural properties of a
variety of thin films with an abundance of applications.",2401.09314v1
2024-01-26,Engineering strong magnetoelectricity using a hexagonal 2D material on electron-doped hexagonal LuFeO$_3$,"Cubic perovskite-structure ABO$_3$ and A$_{1-x}$A$^{\prime}$$_x$BO$_3$-type
oxides have been investigated extensively while their hexagonal-structure
versions have received minimal attention, even though they are multiferroic and
can form heterostructures with the manifold hexagonal two-dimensional
materials. Hexagonal ferrites of the form RFeO$_3$, where R is yttrium or a
rare-earth element such as Lu, Yb, etc., feature coupled ferroelectricity (FE)
and weak-ferromagnetism (wFM), exhibiting linear magnetoelectricity. Their only
drawback is weak ferromagnetism. In this paper, we employ
density-functional-theory (DFT) calculations on hexagonal LuFeO$_3$ ($h$-LFO),
targeting its magnetic ordering by electron doping,anticipating
spin-disproportionation of the Fe sublattices. Indeed, we show that
spin-disproportionation in heavily-electron-doped versions
Lu$_{1-x}$Hf$_x$FeO$_3$ ($h$-LHFO), especially for x=1/3 and 1/2, leads to
robust out-of-plane collinear ferrimagnetism that is stable at room
temperature. Furthermore, the robust ferroelectricity of $h$-LFO persists via a
Jahn-Teller metal-to-insulator transition. Finally, we construct a
$h$-LHFO/$h$-2D heterostructure, where $h$-2D stands for the FE/FM monolayer
MnSTe, and demonstrate strong magnetoelectric coupling, namely manipulation of
magnetic skyrmions in MnSTe by an external electric field through the $h$-LHFO
polarization, opening up a new realm for magnetoelectric applications.",2401.15053v1
2024-01-30,Topological Hall effect induced by chiral fluctuations in a kagome lattice,"Topological Hall effect (THE) is a hallmark of scalar spin chirality, which
is found in static skyrmion lattices. Recent theoretical works have shown that
scalar spin chirality could also emerge dynamically from thermal spin
fluctuations. Evidence of such a mechanism was found in the kagome magnet
YMn6Sn6 where fluctuations arise from frustrated exchange interactions between
Mn kagome layers. In YMn6Sn6, the rare-earth ion Y3+ is non-magnetic. When it
is replaced by a magnetic ion (Gd3+-Ho3+), the intrinsically antiferromagnetic
Mn-Mn interlayer coupling is overwhelmed by the indirect ferromagnetic Mn-R-Mn
one, relieving frustration. This generates interesting anomalous Hall
conductivity, but not THE. Here we show that Er lies in an intermediate regime
where direct and indirect interactions closely compete, so that ErMn6Sn6 can
switch from one regime to the other by temperature, i.e., from a collinear
ferrimagnetic ground state to a spiral antiferromagnet at 78 K. The AFM phase
forms a dome in the temperature-field phase diagram. Close to the boundary of
this dome, we find a sizable fluctuations-driven THE, thus underscoring the
universality of this mechanism for generating non-zero scalar spin chirality.",2401.17449v2
2024-03-06,The role of interfacial interactions and oxygen vacancies in tuning magnetic anisotropy in LaCrO$_{3}$/LaMnO$_{3}$ heterostructures,"The interplay of lattice, electronic, and spin degrees of freedom at
epitaxial complex oxide interfaces provides a route to tune their magnetic
ground states. Unraveling the competing contributions is critical for tuning
their functional properties. We investigate the relationship between magnetic
ordering and magnetic anisotropy and the lattice symmetry, oxygen content, and
film thickness in compressively strained LaMnO$_3$/LaCrO$_3$ superlattices.
Mn-O-Cr antiferromagnetic superexchange interactions across the heterointerface
resulting in a net ferrimagnetic magnetic structure. Bulk magnetometry
measurements reveal isotropic in-plane magnetism for as-grown oxygen-deficient
thinner thin samples due to equal fractions of orthorhombic a+a-c-, and a-a+c-
twin domains. As the superlattice thickness is increased, in-plane magnetic
anisotropy emerges as the fraction of the a+a-c- domain increases. On annealing
in oxygen, the suppression of oxygen vacancies results in a contraction of the
lattice volume, and an orthorhombic to rhombohedral transition leads to
isotropic magnetism independent of the film thickness. The complex interactions
are investigated using high-resolution synchrotron diffraction and X-ray
absorption spectroscopy. These results highlight the role of the evolution of
structural domains with film thickness, interfacial spin interactions, and
oxygen-vacancy-induced structural phase transitions in tuning the magnetic
properties of complex oxide heterostructures.",2403.03764v1
2024-03-25,"Electrically tunable, rapid spin-orbit torque induced modulation of colossal magnetoresistance in Mn$_3$Si$_2$Te$_6$ nanoflakes","As a quasi-layered ferrimagnetic material, Mn$_3$Si$_2$Te$_6$ nanoflakes
exhibit magnetoresistance behaviour that is fundamentally different from their
bulk crystal counterparts. They offer three key properties crucial for
spintronics. Firstly, at least 10^6 times faster response comparing to that
exhibited by bulk crystals has been observed in current-controlled resistance
and magnetoresistance. Secondly, ultra-low current density is required for
resistance modulation (~ 5 A/cm$^2$). Thirdly, electrically gate-tunable
magnetoresistance has been realized. Theoretical calculations reveal that the
unique magnetoresistance behaviour in the Mn$_3$Si$_2$Te$_6$ nanoflakes arises
from a magnetic field induced band gap shift across the Fermi level. The rapid
current induced resistance variation is attributed to spin-orbit torque, an
intrinsically ultra-fast process (~nanoseconds). This study suggests promising
avenues for spintronic applications. In addition, it highlights
Mn$_3$Si$_2$Te$_6$ nanoflakes as a suitable platform for investigating the
intriguing physics underlying chiral orbital moments, magnetic field induced
band variation and spin torque.",2403.16684v1
2024-04-02,Isotropic to nematic transition in alcohol ferrofluids of barium hexaferrite nanoplatelets,"Alcohol ferrofluids made of ferrimagnetic barium hexaferrite (BHF)
nanoplatelets (NPLs) form a unique example of a dipolar fluid - a liquid
magnet. Its formation is induced at a high enough concentration of the NPLs.
The key interactions between the NPLs are long-ranged dipolar magnetic and
screened anisotropic electrostatic. Herein, we report the results on tuning the
isotropic-nematic phase transition (i.e., the NPLs threshold concentration) in
1-butanol ferrofluids of BHF NPLs by affecting the interactions in the
ferrofluids. The threshold concentration was determined by polarizing optical
microscopy (POM) combined with a system for magnetic field manipulation and was
in the range between 4.6 and 6.6 \% (v/v) depending on the ferrofluid. We
observed that the threshold concentration decreased for 0.6 \% (v/v) with a
larger mean diameter of the NPLs, up to 0.6 \% (v/v) with increased ionic
strength of the ferrofluid, and for $\sim$ 2 \% (v/v) with higher saturation
magnetization of the NPLs. We showed that by tuning the parameters affecting
the ferrofluid's interplatelet interactions, we can alter the threshold
concentration for the liquid magnet formation. The results elucidate the
importance of a delicate balance between the repulsive screened electrostatic
and attractive dipolar magnetic interactions for the liquid magnet formation.",2404.01956v1
2005-05-18,The Effect of Gravity Between Particles on the Shape and Resonant Structure of Planetary Rings,"The resonance perturbation of planetary ring by distant satellite is
considered. The gravity interaction between rings particles is taken into
account. The gravitation interaction between particles in rings can change
shape of non-circular rings, so it is differ from keplerian ellipse. The shift
between simple mean motion resonances and parametric resonance zones is
detected. This shift depends on ring properties.",0505364v1
1999-06-15,Dynamics near Resonance Junctions in Hamiltonian Systems,"An approximate Poincare map near equally strong multiple resonances is
reduced by means the method of averaging. Near the resonance junction of three
degrees of freedom, we find that some homoclinic orbits ``whiskers'' in single
resonance lines survive and form nearly periodic orbits, each of which looks
like a pair of homoclinic orbits.",9906025v1
1997-04-03,Search for the πResonance in Two Particle Tunneling Experiments of YBCO Superconductors,"A recent theory of the resonant neutron scattering peaks in YBCO
superconductors predicts the existence of a sharp spin triplet two particle
collective mode (the ``\pi resonance"") in the normal state. In this paper, we
propose an experiment in which the \pi resonance could be probed directly in a
two particle tunneling measurement.",9704022v1
1998-07-16,Resonant multiple Andreev reflections in mesoscopic superconducting junctions,"We investigate the properties of subharmonic gap structure (SGS) in
superconducting quantum contacts with normal-electron resonances. We find two
distinct new features of the SGS in resonant junctions which distinguish them
from non-resonant point contacts: (i) The odd-order structures on the
current-voltage characteristics of resonant junctions are strongly enhanced and
have pronounced peaks, while the even-order structures are suppressed, in the
case of a normal electron resonance being close to the Fermi level. (ii)
Tremendous current peaks develop at $eV=\pm 2E_0$ where $E_0$ indicates a
distance of the resonance to the Fermi level. These properties are determined
by the effect of narrowing of the resonance during multiple Andreev reflections
and by overlap of electron and hole resonances.",9807240v2
1999-03-24,Coherent stochastic resonance in the case of two absorbing boundaries,"The coherent stochastic resonance is observed and studied with multi-step
periodic signal in continuous medium having two absorbing boundaries. The
general features of this process are exihibited. The universal features at the
resonance point are demonstrated. The kinetic behaviors around the resonance
point are also presented.",9903358v2
2001-02-21,Theory of magnetophonon resonance in 2D electron gas in tilted magnetic field,"A theory of magnetophonon resonance in quantum wells in a magnetic field
tilted to the perpendicular to 2DEG is developed. The resonance is due to the
resonant interaction of 2D conduction electrons with the longitudinal optic
phonons. The electrons are assumed to be nondegenerate. The angular dependence
of the resonant maxima is investigated. The sharpness of the angular
dependence, as well as the existence of double resonances, i.e. two resonant
peaks for each resonance number is explained. A relation between the electron
concentration dependence of the resonance amplitude in the perpendicular
magnetic field and the angular dependence in the tilted field is analyzed.
Investigation of the angular dependence can give information concerning the
electron spectra, optic phonon and electron damping and the electron-phonon
interaction in quantum wells.",0102380v2
2003-07-22,Classical dynamics of a nano-mechanical resonator coupled to a single-electron transistor,"We analyze the dynamics of a nano-mechanical resonator coupled to a
single-electron transistor (SET) in the regime where the resonator behaves
classically. A master equation is derived describing the dynamics of the
coupled system which is then used to obtain equations of motion for the average
charge state of the SET and the average position of the resonator. We show that
the action of the SET on the resonator is very similar to that of a thermal
bath, as it leads to a steady-state probability-distribution for the resonator
which can be described by mean values of the resonator position, a renormalized
frequency, an effective temperature and an intrinsic damping constant.
Including the effects of extrinsic damping and finite temperature, we find that
there remain experimentally accessible regimes where the intrinsic damping of
the resonator still dominates its behavior. We also obtain the average current
through the SET as a function of the coupling to the resonator.",0307528v1
2003-08-19,Resonance approximation and charge loading/unloading in adiabatic quantum pumping,"Quantum pumping through mesoscopic quantum dots is known to be enhanced by
resonant transmission. The pumped charge is close to an integer number of
electrons when the pumping contour surrounds a resonance, but the transmission
remains small on the contour. For non-interacting electrons, we give a
quantitative account of the detailed exchange of electrons between the dot and
the leads (to the electron reservoirs) during a pumping cycle. Near isolated
distinct resonances, we use approximate Breit-Wigner expressions for the dot's
Green function to discuss the loading/unloading picture of the pumping: the
fractional charge exchanged between the dot and each lead through a single
resonance point is related to the relative couplings of the dot and the leads
at this resonance. If each resonance point along the pumping contour is
dominated by the coupling to a single lead (which also implies a very small
transmission), then the crossing of each such resonance results in a single
electron exchange between the dot and that lead, ending up with a net quantized
charge. When the resonance approximation is valid, the fractional charges can
also be extracted from the peaks of the transmissions between the various
leads.",0308382v1
2005-09-06,Strong Resonance of Light in a Cantor Set,"The propagation of an electromagnetic wave in a one-dimensional fractal
object, the Cantor set, is studied. The transfer matrix of the wave amplitude
is formulated and its renormalization transformation is analyzed. The focus is
on resonant states in the Cantor set. In Cantor sets of higher generations,
some of the resonant states closely approach the real axis of the wave number,
leaving between them a wide region free of resonant states. As a result, wide
regions of nearly total reflection appear with sharp peaks of the transmission
coefficient beside them. It is also revealed that the electromagnetic wave is
strongly enhanced and localized in the cavity of the Cantor set near the
resonant frequency. The enhancement factor of the wave amplitude at the
resonant frequency is approximately $6/|\eta_\mathrm{r}|$, where
$\eta_\mathrm{r}$ is the imaginary part of the corresponding resonant
eigenvalue. For example, a resonant state of the lifetime
$\tau_\mathrm{r}=4.3$ms and of the enhancement factor $M=7.8\times10^7$ is
found at the resonant frequency $\omega_\mathrm{r}=367$GHz for the Cantor set
of the fourth generation of length L=10cm made of a medium of the dielectric
constant $\epsilon=10$.",0509145v1
2006-03-14,Quantum resonance and anti-resonance for a periodically kicked Bose-Einstein Condensate in a one dimensional Box,"We investigate the quantum dynamics of a periodically kicked Bose-Einstein
Condensate confined in a one dimensional (1D) Box both numerically and
theoretically, emphasizing on the phenomena of quantum resonance and
anti-resonance. The quantum resonant behavior of BEC is different from the
single particle case but the anti-resonance condition ($T = 2\pi$ and $\alpha =
0$) is not affected by the atomic interaction. For the anti-resonance case, the
nonlinearity (atom interaction) causes the transition between oscillation and
quantum beating. For the quantum resonance case, because of the coherence of
BEC, the energy increase is oscillating and the rate is dramatically affected
by the many-body interaction. We also discuss the relation between the quantum
resonant behavior and the KAM or non-KAM property of the corresponding
classical system.",0603362v1
2007-02-26,Graphene-based resonant-tunneling strucures,"Resonant electronic transmission through graphene-based double barriers
(wells) is studied as a function of the incident wave vector, the widths and
heights (depths) of the barriers (wells), and the separation between them.
Resonant features in the transmission result from resonant electron states in
the wells or hole states in the barriers and strongly influence the ballistic
conductance of the structures.",0702596v1
1999-03-09,Remarks on parametric resonance of neutrino oscillations in the earth,"Neutrino oscillations in matter can exhibit a specific resonance enhancement
-- parametric resonance, which is different from the MSW resonance. Recently it
has been shown that the oscillations of atmospheric and solar neutrinos inside
the earth can undergo parametric enhancement when neutrino trajectories cross
the core of the earth. In this paper we continue the study of the parametric
resonance of neutrino oscillations in the earth. The following issues are
discussed: stability of the resonance with respect to the variations of the
zenith angle of the neutrino source; higher-order resonances; prospects of the
experimental observation of the parametric resonance of neutrino oscillations.
We also comment on a recent controversy regarding the physical nature of the
resonance enhancement of the oscillations of the core crossing neutrinos in the
earth.",9903302v1
2002-05-17,Time advancement in resonance regions of pi-N scattering,"We evaluate the time delay in some of the established resonance regions of
$\pi N$ elastic scattering. In addition to the positive peaks corresponding to
resonances, we identify broad regions of negative time delay or time
advancement which restrict the energy ranges within which the resonances can be
located.",0205188v1
2003-05-23,Resonances for steplike potentials: forward and inverse results,"We consider resonances associated to the operator $-\frac{d^2}{dx^2}+V(x)$,
where $V(x)=V_+$ if $x>x_M$ and $V(x)=V_-$ if $x<-x_M$, with $V_+\not = V_-$.
We obtain asymptotics of the resonance-counting function in several regions.
Moreover, we show that in several situations, the resonances, $V_+$, and $V_-$
determine $V$ uniquely up to translation.",0305335v1
2004-12-30,"Noncommutative Algebras, Nano-Structures, and Quantum Dynamics Generated by Resonances","We observe ``quantum'' properties of resonance equilibrium points and
resonance univariant submanifolds in the phase space. Resonances between
Birkhoff or Floquet--Lyapunov frequencies generate quantum algebras with
polynomial commutation relations. Irreducible representations and coherent
states of these algebras correspond to certain quantum nano-structure near the
classical resonance motion. Based on this representation theory and
nano-geometry, for equations of Schr\""odinger or wave type in various regimes
and zones (up to quantum chaos borders) we describe the resonance spectral and
long-time asymptotics, resonance localization and focusing, resonance adiabatic
and spin-like effects. We discuss how the mathematical phase space
nano-structures relate to physical nanoscale objects like dots, quantum wires,
etc. We also demonstrate that even in physically macroscale Helmholtz channels
the resonance implies a specific quantum character of classical wave
propagation.",0412542v2
1998-10-26,Resonances In a Box,"We investigate a numerical method for studying resonances in quantum
mechanics. We prove rigorously that this method yields accurate approximations
to resonance energies and widths for shape resonances in the semiclassical
limit.",9810018v1
2004-03-19,Scattering of solitons on resonance,"We investigate a propagation of solitons for nonlinear Schrodinger equation
under small driving force. The driving force passes the resonance. The process
of scattering on the resonance leads to changing of number of solitons. After
the resonance the number of solitons depends on the amplitude of the driving
force.",0403038v1
2000-05-02,A Relationship Between Parametric Resonance and Chaos,"In this paper we study two types of exponential instability -- parametric
resonance and chaos. We show that a given equation may produce chaos or
parametric resonance, depending how the problem is defined. In so doing we
establish a relationship between the Floquet indices (associated with
parametric resonance) and Lyapunov exponents (associated with chaos).",0005005v1
2003-09-27,Renormalization Analysis of Resonance Structure in 2-D Symplectic Map,"A symplecticity-preserving RG analysis is carried out to study a resonance
structure near an elliptic fixed point of a proto-type symplectic map in two
dimensions. Through analyzing fixed points of a reduced RG map, a topology of
the resonance structure such as a chain of resonant islands can be determined
analytically. An application of this analysis to the Henon map is also
presented.",0309072v1
2005-05-08,Resonance-assisted tunneling in three degrees of freedom without discrete symmetry,"We study dynamical tunneling in a near-integrable Hamiltonian with three
degrees of freedom. The model Hamiltonian does not have any discrete symmetry.
Despite this lack of symmetry we show that the mixing of near-degenerate
quantum states is due to dynamical tunneling mediated by the nonlinear
resonances in the classical phase space. Identifying the key resonances allows
us to suppress the dynamical tunneling via the addition of weak
counter-resonant terms.",0505020v1
2005-01-11,The search for missing baryon resonances,"Experiments with electromagnetic probes are promising to search for baryon
resonances that have been predicted by quark models but have not yet been
observed. Data sets from different experiments show interesting resonance
structures possibly due to so far unknow states. This might indicate that at
least some of the missing baryon resonances start to show up.",0501007v1
2000-05-13,Probing the Structure of Nucleons in the Resonance Region,"Status, open questions, and future prospects of the physics of excited
nucleons are discussed. Emphasis is on the study of the structure of nucleons
via measurements of their electromagnetic transition form factors, the search
for ""missing"" resonances, the spin structure of the nucleon in the resonance
region, and connections between the resonance and the deep-inelastic regimes.",0005033v1
2002-01-23,Relativistic Heavy Ion Excitation of Giant Resonances,"Giant resonances and giant resonances built on other giant resonances in
nuclei are observed with very large cross sections in relativistic heavy ion
collisions. A theoretical effort is underway to understand the reaction
mechanism which leads to this process, as well as a better understanding of the
microscopic properties of multiphonon states, e.g., their strength, energy
centroids, widths and anharmonicities.",0201060v1
2002-02-03,Search for new baryon resonances,"Within a chiral constituent quark formalism, allowing the inclusion of all
known resonances, a comprehensive study of the recent eta photoproduction data
on the proton up to 2 GeV is performed. This study shows evidence for a new S11
resonances and indicates the presence of an additional missing P13 resonance.",0202007v1
2004-06-17,Nucleon resonances and processes involving strange particles,"An existing single resonance model with S11, P11 and P13 Breit-Wiegner
resonances in the s-channel has been re-applied to the old pi N --> K Lambda
data. It has been shown that the standard set of resonant parameters fails to
reproduce the shape of the differential cross section. The resonance parameter
determination has been repeated retaining the most recent knowledge about the
nucleon resonances. The extracted set of parameters has confirmed the need for
the strong contribution of a P11(1710) resonance. The need for any significant
contribution of the P13 resonance has been eliminated. Assuming that the Baker.
et al data set\cite{Bak78} is a most reliable one, the P11 resonance can not
but be quite narrow. It emerges as a good candidate for the non-strange counter
partner of the established pentaquark anti-decuplet.",0406057v1
2002-10-23,170 Nanometer Nuclear Magnetic Resonance Imaging using Magnetic Resonance Force Microscopy,"We demonstrate one-dimensional nuclear magnetic resonance imaging of the
semiconductor GaAs with 170 nanometer slice separation and resolve two regions
of reduced nuclear spin polarization density separated by only 500 nanometers.
This is achieved by force detection of the magnetic resonance, Magnetic
Resonance Force Microscopy (MRFM), in combination with optical pumping to
increase the nuclear spin polarization. Optical pumping of the GaAs creates
spin polarization up to 12 times larger than the thermal nuclear spin
polarization at 5 K and 4 T. The experiment is sensitive to sample volumes
containing $\sim 4 \times 10^{11}$ $^{71}$Ga$/\sqrt{Hz}$. These results
demonstrate the ability of force-detected magnetic resonance to apply magnetic
resonance imaging to semiconductor devices and other nanostructures.",0210099v1
2004-09-21,"Electrodynamical properties of a ""grid"" volume resonator for travelling wave tube and backward wave oscillator","The electrodynamical properties of a volume resonator formed by a perodic
structure built from the metallic threads inside a rectangular waveguide
(""grid"" volume resonator) is considered for travelling wave tube and backward
wave oscillator operation. Peculiarities of passing of electromagnetic waves
with different polarizations through such volume resonator are discussed.",0409107v2
2007-05-30,"Resonant spin polarization in a two-dimensional hole gas: Effect of the Luttinger term, structural inversion asymmetry and Zeeman splitting","The electric-field-induced resonant spin polarization of a two-dimensional
hole gas described by Luttinger Hamiltonian with structural inversion asymmetry
and Zeeman splitting in a perpendicular magnetic field was studied. The spin
polarization arising from splitting between the light and the heavy hole bands
shows a resonant peak at a certain magnetic field. Especially, the competition
between the Luttinger term and the structural inversion asymmetry leads to a
rich resonant peaks structure, and the required magnetic field for the
resonance may be effectively reduced by enlarging the effective width of the
quantum well. Furthermore, the Zeeman splitting tends to move the resonant spin
polarization to a relative high magnetic field and destroy these rich resonant
spin phenomena. Finally, both the height and the weight of the resonant peak
increase as the temperature decreases. It is believed that such resonant spin
phenomena can be verified in the sample of a two-dimensional hole gas, and it
may provide an efficient way to control spin polarization by an external
electric field.",0705.4355v2
2007-10-03,Magnetic and Electric Excitations in Split Ring Resonators,"We studied the electric and magnetic resonance of U-shaped SRRs. We showed
that higher order excitation modes exist in both of the electric and magnetic
resonances. The nodes in the current distribution were found for all the
resonance modes. It turns out that the magnetic resonances are the modes with
odd-number of half-wavelength of the current wave, i.e. 1/2, 3/2 and 5/2
wavelengths modes, and the electric resonances are modes with integer number of
whole-wavelength of current wave, i.e. 1, 2 and 3 wavelengths modes. We
discussed the electric moment and magnetic moment of the electric and magnetic
resonances, and their dependence to the length of two parallel side arms. We
show that the magnetic moment of magnetic resonance vanishes as the length side
arms of the SRR reduces to zero, i.e. a rod does not give any magnetic moment
or magnetic resonance.",0710.0812v2
2007-10-19,Unified description of resonance and decay phenomena,"In the Feshbach projection operator formalism, resonance as well as decay
phenomena are described by means of the complex eigenvalues and eigenfunctions
of the non-Hermitian Hamilton operator $H_{\rm eff}$ that appears in an
intermediate stage of the formalism. The formalism can be applied for the
description of isolated resonances as well as for resonances in the overlapping
regime. Time asymmetry is related to the time operator which is a part of
$H_{\rm eff}$. An expression for the decay rates of resonance states is
derived. For isolated resonance states $\lambda$, this expression gives the
fundamental relation $\tau_\lambda = \hbar / \Gamma_\lambda$ between life time
and width of a resonance state. A similar relation holds for the average values
obtained for narrow resonances superposed by a smooth background term. In the
cross over between these two cases (regime of overlapping resonances), the
decay rate decreases monotonously as a function of increasing time.",0710.3661v1
2008-01-09,Derivation of the spatio-temporal model equations for the thermoacoustic resonator,"We derive the model equations describing the thermoacoustic resonator, that
is, an acoustical resonator containing a viscous medium inside. Previous
studies on this system have addressed this sytem in the frame of the plane-wave
approximation, we extend the previous model to by considering spatial effects
in a large aperture resonator. This model exhibits pattern formation and
localized structures scenario.",0801.1454v1
2008-05-07,Brillouin Lasing with a CaF_2 Whispering Gallery Mode Resonator,"Stimulated Brillouin scattering with both pump and Stokes beams in resonance
with whispering gallery modes of an ultra high Q CaF_2 resonator is
demonstrated for the first time. The resonator is pumped with 1064 nm light and
has a Brillouin lasing threshold of 3.5 microwatt. Potential applications
include optical generation of microwaves and sensitive gyros.",0805.0803v1
2008-05-22,Lineshape Asymmetry for joint CPT and three photon N resonances,"We show that a characteristic two photon lineshape asymmetry arises in
coherent population trapping (CPT) and three photon (N) resonances because both
resonances are simultaneously induced by modulation sidebands in the
interrogating laser light. The N resonance is a three-photon resonance in which
a two-photon Raman excitation is combined with a resonant optical pumping
field. This joint CPT and N resonance can be the dominant source of lineshape
distortion, with direct relevance for the operation of miniaturized atomic
frequency standards. We present the results of both an experimental study and
theoretical treatment of the asymmetry of the joint CPT and N resonance under
conditions typical to the operation of an N resonance clock.",0805.3384v1
2008-08-20,Inverse resonance scattering for Jacobi operators,"We consider the Jacobi operator $(Jf)_n= a_{n-1}f_{n-1}+a_nf_{n+1}+b_nf_n$ on
$\Z$ with a real compactly supported sequences $(a_n-1)_{n\in\Z}$ and
$(b_n)_{n\in\Z}$. We give the solution of two inverse problems (including
characterization): $ (a,b)\to \{$zeros of the reflection coefficient$\}$ and
$(a,b)\to \{$bound states and resonances$\}$. We describe the set of
""iso-resonance operators $J$"", i.e., all operators $J$ with the same resonances
and bound states.",0808.2805v1
2008-12-01,On the validity of nonlinear Alfven resonance in space plasmas,"In the approximation of linear dissipative magnetohydrodynamics (MHD) it can
be shown that driven MHD waves in magnetic plasmas with high Reynolds number
exhibit a near resonant behaviour if the frequency of the wave becomes equal to
the local Alfven (or slow) frequency of a magnetic surface. This near resonant
behaviour is confined to a thin region, known as the dissipative layer, which
embraces the resonant magnetic surface. Although driven MHD waves have small
dimensionless amplitude far away from the resonant surface, this near-resonant
behaviour in the dissipative layer may cause a breakdown of linear theory. Our
aim is to study the nonlinear effects in the Alfven dissipative layer. In the
present paper, the method of simplified matched asymptotic expansions developed
for nonlinear slow resonant waves is used to describe nonlinear effects inside
the Alfven dissipative layer. The nonlinear corrections to resonant waves in
the Alfven dissipative layer are derived and it is proved that at the Alfven
resonance (with isotropic/anisotropic dissipation) wave dynamics can be
described by the linear theory with great accuracy.",0812.0291v1
2009-02-17,Fano resonances in nanoscale structures,"Nowadays nanotechnology allows to scale-down various important devices
(sensors, chips, fibres, etc), and, thus, opens up new horizon for their
applications. Nevertheless, the efficiency most of them is still based on the
fundamental physical phenomena, such as resonances. Thus, the understanding of
the resonance phenomena will be beneficial. One of the well-known examples is
the resonant enhancement of the transmission known as Breit-Wigner resonances,
which can be described by a Lorentzian function. But, in many physical systems
the scattering of waves involves propagation along different paths, and, as a
consequence, results in interference phenomena, where constructive interference
corresponds to resonant enhancement and destructive interference to resonant
suppression of the transmission. Recently, a variety of experimental and
theoretical work has revealed such patterns in different branches of physics.
The purpose of this Review is to demonstrate that this kind of resonant
scattering is related to the Fano resonances, known from atomic physics. One of
the main features of the Fano resonances is the asymmetric profile. The
asymmetry comes from the close coexistence of resonant transmission and
resonant reflection. Fano successfully explained such a phenomenon in his
seminal paper in 1961 in terms of interaction of a discrete (localized) state
with a continuum of propagation modes. It allows to describe both resonant
enhancement and resonant suppression in a unified manner. All of these
properties can be demonstrated in the frame of a very simple model, which will
be used throughout the Review to show that resonant reflections observed in
different complex systems are indeed closely related to the Fano resonances.",0902.3014v4
2009-03-10,Spectrum of a fluid-loaded vibrating plate: the multiple resonance phenomenon,"It was recently observed in a numerical study on a high order perturbation
method under heavy fluid loading that a loaded vibrating plate results, not
only in the classical frequency shift of the in vacuo single resonance (in both
the real part because of the fluid added mass and the imaginary part because of
energy lost by radiation), but also in an increase in the number of the
resonance. As a result of the loading, a single in vacuo resonance of the
structure is transformed into a multiple resonance. Here we show that this
phenomenon is a refinement of the Sanchez's classical result where it was
established, using asymptotic analysis, that in the case of a light loading
conditions "" the scattering frequencies of a fluid loaded elastic structure (ie
the resonance frequencies) are nearly the real eigenfrequencies of the elastic
body alone and the complex scattering frequencies of the fluid with a rigid
solid "". A theoretical explanation of the multiple resonances is given using
classical results on theory of entire functions. It is established that every
single in vacuo resonance of a simply supported rectangular plate is
transformed into an infinite number of resonances under fluid-loading
condition.",0903.1704v1
2009-03-24,Outer Resonances and Effective Potential Analogy in Two-Dimensional Dielectric Cavities,"Outer resonances are studied as one type of quasinormal modes in
two-dimensional dielectric cavities with refractive index $n>1$. The outer
resonances can be verified as the resonances which survive only outside the
cavity in the small opening limit of the dielectric disk. We have confirmed
that the outer resonances universally exist in deformed cavities irrespective
of the geometry of cavity and they split into nearly degenerate states in
slightly deformed cavity. Also we pointed out that the effective potential
analogy is inapplicable to the description of outer resonances. Since most
outer resonances in the dielectric cavities have quite high leakages, they
would affect to the broad background in the density of states. Especially, for
TE polarization case, relatively low-leaky outer resonances exist and it
presents the possibility that they can interact with the inner resonances and
affect lasing modes.",0903.4034v3
2009-05-01,Nonlinear resonances of water waves,"In the last fifteen years, a great progress has been made in the
understanding of the nonlinear resonance dynamics of water waves. Notions of
scale- and angle-resonances have been introduced, new type of energy cascade
due to nonlinear resonances in the gravity water waves have been discovered,
conception of a resonance cluster has been much and successful employed, a
novel model of laminated wave turbulence has been developed, etc. etc. Two
milestones in this area of research have to be mentioned: a) development of the
$q$-class method which is effective for computing integer points on the
resonance manifolds, and b) construction of the marked planar graphs, instead
of classical resonance curves, representing simultaneously all resonance
clusters in a finite spectral domain, together with their dynamical systems.
Among them, new integrable dynamical systems have been found that can be used
for explaining numerical and laboratory results. The aim of this paper is to
give a brief overview of our current knowledge about nonlinear resonances among
water waves, and formulate three most important open problems at the end.",0905.0050v2
2009-07-04,On resonance parameter measurement and luminosity determination at e+e- collider,"Expounded are the parameter measurement for narrow resonance and
determination of corresponding luminosity at e+e- collider. The detailed
theoretical formulas are compiled and the crucial experimental effects on
observed cross section are taken into account. For luminosity determination,
the iteration method is put forth which is mainly used to separate the
interference effect between resonance and non-resonance decays.",0907.0734v1
2009-09-08,Giant Slow Wave Resonance for Light Amplification and Lasing,"We apply the idea of giant slow wave resonance associated with a degenerate
photonic band edge to gain enhancement of active media. This approach allows to
dramatically reduce the size of slow wave resonator while improving its
performance as gain enhancer for light amplification and lasing. It also allows
to reduce the lasing threshold of the slow wave optical resonator by at least
an order of magnitude.",0909.1393v1
2009-11-12,Spin Resonance and dc Current Generation in a Quantum Wire,"We show that in a quantum wire the spin-orbit interaction leads to a narrow
spin resonance at low temperatures, even in the absence of an external magnetic
field. Resonance absorption by linearly polarized radiation gives a dc spin
current; resonance absorption by circularly polarized radiation gives a dc
electric current or magnetization.",0911.2433v1
2009-11-22,Power-dependent internal loss in Josephson bifurcation amplifiers,"We have studied nonlinear superconducting resonators: lambda/2
coplanar-waveguide (CPW) resonators with Josephson junctions (JJs) placed in
the middle and lambda/4 CPW resonators terminated by JJs, which can be used for
the qubit readout as ""bifurcation amplifiers."" The nonlinearity of the
resonators arises from the Josephson junctions, and because of the
nonlinearity, the resonators with appropriate parameters are expected to show a
hysteretic response to the frequency sweep, or ""bifurcation,"" when they are
driven with a sufficiently large power. We designed and fabricated resonators
whose resonant frequencies were around 10 GHz. We characterized the resonators
at low temperatures, T<0.05 K, and confirmed that they indeed exhibited
hysteresis. The sizes of the hysteresis, however, are sometimes considerably
smaller than the predictions based on the loaded quality factor in the weak
drive regime. When the discrepancy appears, it is mostly explained by taking
into account the internal loss, which often increases in our resonators with
increasing drive power in the relevant power range. As a possible origin of the
power-dependent loss, the quasiparticle channel of conductance of the JJs is
discussed.",0911.4221v1
2010-08-17,Loss Dependence on Geometry and Applied Power in Superconducting Coplanar Resonators,"The loss in superconducting microwave resonators at low-photon number and low
temperatures is not well understood but has implications for achievable
coherence times in superconducting qubits. We have fabricated single-layer
resonators with a high quality factor by patterning a superconducting aluminum
film on a sapphire substrate. Four resonator geometries were studied with
resonant frequencies ranging from 5 to 7 GHz: a quasi-lumped element resonator,
a coplanar strip waveguide resonator, and two hybrid designs that contain both
a coplanar strip and a quasi-lumped element. Transmitted power measurements
were taken at 30 mK as a function of frequency and probe power. We find that
the resonator loss, expressed as the inverse of the internal quality factor,
decreases slowly over four decades of photon number in a manner not merely
explained by loss from a conventional uniform spatial distribution of two-level
systems in an oxide layer on the superconducting surfaces of the resonator.",1008.2929v2
2011-10-25,Transitional dynamics of a phase qubit-resonator system: requirements for fast readout of a phase qubit,"We examine the non-stationary evolution of a coupled qubit-transmission
line-resonator system coupled to an external drive and the resonator
environment. By solving the equation for a non-stationary resonator field, we
determined the requirements for a single-shot non-destructive dispersive
measurement of the phase qubit state. Reliable isolation of the qubit from the
""electromagnetic environment"" is necessary for a dispersive readout and can be
achieved if the whole system interacts with the external fields only through
the resonator that is weakly coupled to the qubit. A set of inequalities
involving resonator-qubit detuning and coupling parameter, the resonator
leakage and the measurement time, together with the requirement of multi-photon
outgoing flux is derived. It is shown, in particular, that a decrease of the
measurement time requires an increase of the resonator leakage. This increase
results in reducing the quality factor and decreasing the resolution of the
resonator eigenfrequencies corresponding to different qubit states. The
consistent character of the derived inequalities for two sets of experimental
parameters is discussed. The obtained results will be useful for optimal design
of experimental setups, parameters, and measurement protocols.",1110.5566v1
2012-09-01,Complex Permittivity Measurements at Variable Temperatures of Low Loss Dielectric Substrates Employing Split Post and Single Post Dielectric Resonators,"A split post dielectric resonator in a copper enclosure and a single post
dielectric resonator in a cavity with superconducting end-plates have been
constructed and used for the complex permittivity measurements of single
crystal substrates. (La,Sr)(Al,Ta)O3, LaAlO3, MgO and quartz substrates have
been measured at temperatures from 20 K to 300 K in the split post resonator
and from 15 K to 80 K in the single post resonator. The TE01delta mode resonant
frequencies and unloaded Qo-factors of the empty resonators at temperature of
20 K were: 9.952 GHz and 25,000 for the split post resonator and 10.808 GHz and
240,000 for the single post resonator respectively.",1209.0111v1
2012-10-30,Shifts and widths of Feshbach resonances in atomic waveguides,"We develop and analyze a theoretical model which yields the shifts and widths
of Feshbach resonances in an atomic waveguide. It is based on a multichannel
approach for confinement-induced resonances (CIRs) and atomic transitions in
the waveguides in the multimode regime. We replace in this scheme the
single-channel scalar interatomic interaction by the four-channel tensorial
potential modeling resonances of broad, narrow and overlapping character
according to the two-channel parametrization of A.D.Lange et al. As an input
the experimentally known parameters of Feshbach resonances in the absence of
the waveguide are used. We calculate the shifts and widths of s-, d- and g-wave
magnetic Feshbach resonances of Cs atoms emerging in harmonic waveguides as
CIRs and resonant enhancement of the transmission at zeros of the free space
scattering length. We have found the linear dependence of the width of the
resonance on the longitudinal atomic momentum and quadratic dependence on the
waiveguide width. Our model opens novel possibilities for quantitative studies
of the scattering processes in ultracold atomic gases in waveguides beyond the
framework of s-wave resonant scattering.",1210.7984v2
2012-11-29,Pumping K-Alpha Resonance Fluorescence by Monochromatic X-Ray Sources,"We demonstrate the correspondence between theoretically calculated K-shell
resonances lying below the K-edge in multiple ionization states of an element
(Pradhan et al. 2009), and recently observed K-alpha resonances in
high-intensity X-ray free-electron laser (XFEL) plasmas (Vinko et al. 2012).
Resonant absorptions in aluminum ions are computed and found to reproduce
experimentally observed features. Results are also presented for titanium for
possible observation of K-alpha resonances in the 4.5-5.0 keV energy range. A
possibly sustainable excitation mechanism for K-alpha resonance fluorescence
might be implemented using two monochromatic X-ray beams tuned to the K-edge
and the K-alpha resonant energies simultaneously. This targeted
ionization/excitation would create inner-shell vacancies via Auger decay, as
well as pump K-alpha resonances. The required X-ray fluence to achieve
resonance fluorescence would evidently be much less than in the XFEL
experiments, and might enable novel biomedical applications.",1211.7041v1
2012-12-19,Topological Resonances in Scattering on Networks (Graphs),"We report on a hitherto unnoticed type of resonances occurring in scattering
from networks (quantum graphs) which are due to the complex connectivity of the
graph - its topology. We consider generic open graphs and show that any cycle
leads to narrow resonances which do not fit in any of the prominent paradigms
for narrow resonances (classical barriers, localization due to disorder,
chaotic scattering). We call these resonances `topological' to emphasize their
origin in the non-trivial connectivity. Topological resonances have a clear and
unique signature which is apparent in the statistics of the resonance
parameters (such as e.g., the width, the delay time or the wave-function
intensity in the graph). We discuss this phenomenon by providing analytical
arguments supported by numerical simulation, and identify the features of the
above distributions which depend on genuine topological quantities such as the
length of the shortest cycle (girth). These signatures cannot be explained
using any of the other paradigms for narrow resonances. Finally, we propose an
experimental setting where the topological resonances could be demonstrated,
and study the stability of the relevant distribution functions to moderate
dissipation.",1212.4682v1
2013-03-16,Method of images applied to an opto-mechanical Fabry-Perot resonator,"The method of images, when applied to an opto-mechanical Fabry-Perot
resonator with a heavy, charged mirror, and a light, charged mirror that can be
driven into motion, reveals that the highest order images can move
relativistically when the Q of the superconducting resonator is on the order of
10^10. The implications of such relativistic motions of the charge and mass of
these images to the emission of electromagnetic and gravitational radiation
within the resonator is explored.",1303.4020v1
2013-04-08,Energy and lifetime of resonant states with real basis sets,"Using a probabilistic interpretation of resonant states, we propose a formula
useful to calculate the lifetime of a resonance using square-integrable real
basis-set expansion techniques. Our approach does not require an estimation of
the density of states. The method is illustrated with calculations of $s$ and
$p$ resonant-state energies and lifetimes.",1304.2136v2
2013-04-15,Vibrational Resonance in the Morse Oscillator,"We investigate the occurrence of vibrational resonance in both classical and
quantum mechanical Morse oscillators driven by a biharmonic force. The
biharmonic force consists of two forces of widely different frequencies \omega
and \Omega with \Omega>>\omega. In the damped and biharmonically driven
classical Morse oscillator applying a theoretical approach we obtain an
analytical expression for the response amplitude at the low-frequency \omega.
We identify the conditions on the parameters for the occurrence of the
resonance. The system shows only one resonance and moreover at resonance the
response amplitude is 1/(d\omega) where d is the coefficient of linear damping.
When the amplitude of the high-frequency force is varied after resonance the
response amplitude does not decay to zero but approaches a nonzero limiting
value. We have observed that vibrational resonance occurs when the sinusoidal
force is replaced by a square-wave force. We also report the occurrence of
resonance and anti-resonance of transition probability of quantum mechanical
Morse oscillator in the presence of the biharmonic external field.",1304.3988v1
2013-05-28,Analytical Treatment of Planetary Resonances,"An ever-growing observational aggregate of extrasolar planets has revealed
that systems of planets that reside in or near mean-motion resonances are
relatively common. While the origin of such systems is attributed to
protoplanetary disk-driven migration, a qualitative description of the
dynamical evolution of resonant planets remains largely elusive. Aided by the
pioneering works of the last century, we formulate an approximate, integrable
theory for first-order resonant motion. We utilize the developed theory to
construct an intuitive, geometrical representation of resonances within the
context of the unrestricted three-body problem. Moreover, we derive a simple
analytical criterion for the appearance of secondary resonances between
resonant and secular motion. Subsequently, we demonstrate the onset of rapid
chaotic motion as a result of overlap among neighboring first-order mean-motion
resonances, as well as the appearance of slow chaos as a result of secular
modulation of the planetary orbits. Finally, we take advantage of the
integrable theory to analytically show that, in the adiabatic regime, divergent
encounters with first-order mean-motion resonances always lead to persistent
apsidal anti-alignment.",1305.6513v1
2013-07-09,Resonances for Dirac operators on the half-line,"We consider the 1D Dirac operator on the half-line with compactly supported
potentials. We study resonances as the poles of scattering matrix or
equivalently as the zeros of modified Fredholm determinant. We obtain the
following properties of the resonances: 1) asymptotics of counting function, 2)
estimates on the resonances and the forbidden domain.",1307.2478v1
2013-11-15,Singular evanescent wave resonances,"Resonators fold the path of light by reflections leading to a phase balance
and thus constructive addition of propagating waves. However, amplitude
decrease of these waves due to incomplete reflection or material absorption
leads to a finite quality factor of all resonances. Here we report on our
discovery that evanescent waves can lead to a perfect phase and amplitude
balance causing an ideal Fabry-Perot resonance condition in spite of material
absorption and non-ideal reflectivities. This counterintuitive resonance occurs
if and only if the metallic Fabry-Perot plates are in relative motion to each
other separated by a critical distance. We show that the energy needed to
approach the resonance arises from the conversion of the mechanical energy of
motion to electromagnetic energy. The phenomenon is similar to lasing where the
losses in the cavity resonance are exactly compensated by optical gain media
instead of mechanical motion. Nonlinearities and non-localities in material
response will inevitably curtail any singularities however we show the giant
enhancement in non-equilibrium phenomena due to such resonances in moving
media.",1311.3718v3
2013-12-01,Differential Entropy Dynamics: A Possible Cause of Coherence Resonance,"Coherence resonance can be explained using differential entropy and mutual
information. This theory explores the role of external noise in stabilising
chaotic circuits such as the uni-junction transistor relaxation oscillator.The
phenomenon of coherence resonance maximizes differential entropy and mutual
information.Thus most natural chaotic oscillators show coherence resonance in
the presence of an external driving noise.",1312.0203v1
2014-02-26,Optimal lower bound of the resonance widths for the Helmholtz Resonator,"Under a geometric assumption on the region near the end of its neck, we prove
an optimal exponential lower bound on the widths of resonances for a general
two-dimensional Helmholtz resonator. An extension of the result to the
n-dimensional case, n smaller than 12, is also obtained.",1402.6493v2
2014-04-24,Resonances for the radial Dirac operators,"We consider the radial Dirac operator with compactly supported potentials. We
study resonances as the poles of scattering matrix or equivalently as the zeros
of modified Fredholm determinant. We obtain the following properties of the
resonances: 1) asymptotics of counting function, 2) in the massless case we get
the trace formula in terms of resonances.",1404.6078v2
2014-04-25,Waveguide couplers for ferroelectric optical resonators,"We report a study of using the same material to fabricate a whispering
gallery mode resonator and a coupler. Coupling to high Q whispering gallery
modes of the lithium niobate resonator is demonstrated by means of the
titanium-doped waveguide. The waveguide coupling approach opens possibilities
for simpler and wider practical usage of whispering gallery mode resonators and
their integration into optical devices.",1404.6582v1
2014-04-29,Temporal behavior of laser induced elastic plate resonances,"This paper investigates the dependence on Poisson's ratio of local plate
resonances in low attenuating materials. In our experiments, these resonances
are generated by a pulse laser source and detected with a heterodyne
interferometer measuring surface displacement normal to the plate. The laser
impact induces a set of resonances that are dominated by Zero Group Velocity
(ZGV) Lamb modes. For some Poisson's ratio, thickness-shear resonances are also
detected. These experiments confirm that the temporal decay of ZGV modes
follows a $t^{-0.5}$ law and show that the temporal decay of the thickness
resonances is much faster. Similar decays are obtained by numerical simulations
achieved with a finite difference code. A simple model is proposed to describe
the thickness resonances. It predicts that a thickness mode decays as
$t^{-1.5}$ for large times and that the resonance amplitude is proportional to
$D^{-1.5}$ where $D$ is the curvature of the dispersion curve $\omega(k)$ at
$k=0$. This curvature depends on the order of the mode and on the Poisson's
ratio, and it explains why some thickness resonances are well detected while
others are not.",1404.7464v2
2014-09-03,A number theoretical observation of a resonant interaction of Rossby waves,"Rossby waves are generally expected to dominate the $\beta$ plane dynamics in
geophysics, and here in this paper we give a number theoretical observation of
the resonant interaction with a Diophantine equation. The set of resonant
frequencies does not have any frequency on the horizontal axis. We also give
several clusters of resonant frequencies.",1409.1031v1
2015-02-23,Demonstration of whispering-gallery-mode resonant enhancement of optical forces,"We experimentally studied whispering-gallery modes(WGMs) and demonstrated
resonance enhancement of optical forces evanescently exerted on dielectric
microspheres. We showed that the resonant light pressure can be used for
optical sorting of microparticles with extraordinary uniform resonant
properties that is unachievable by conventional sorting techniques.",1502.06298v1
2015-02-26,Active and reactive power in stochastic resonance for energy harvesting,"A power allocation to active and reactive power in stochastic resonance is
discussed for energy harvesting from mechanical noise. It is confirmed that
active power can be increased at stochastic resonance, in the same way of the
relationship between energy and phase at an appropriate setting in resonance.",1503.04084v1
2015-04-21,Resonance widths for general Helmholtz Resonators with straight neck,"We prove an optimal exponential lower bound on the width of the resonance
associated to the first eigenvalue of the cavity for a general Helmholtz
resonator with straight neck, in any dimension.",1504.05425v1
2015-04-17,On the ambiguity of determination of interfering resonances parameters,"The general form of solutions for parameters of interfering Breit-Wigner
resonances is found. The number of solutions is determined by the properties of
roots of corresponding characteristic equation and does not exceed $2^{N-1}$,
where $N$ is the number of resonances. For resonances of more complicated form,
provided that their amplitudes satisfy certain conditions, for any $N\ge2$
multiple solutions also exist.",1505.01509v1
2015-05-26,A time domain based method for the accurate measurement of Q-factor and resonance frequency of microwave resonators,"We present a novel method to determine the resonant frequency and quality
factor of microwave resonators which is faster, more stable, and conceptually
simpler than the yet existing techniques. The microwave resonator is irradiated
at a frequency away from its resonance. It then emits an exponentially decaying
radiation at its eigen-frequency when the excitation is rapidly switched off.
The emission is down-converted with a microwave mixer, digitized and its
Fourier transformation (FT) directly yields the resonance curve in a single
shot. Being an FT based method, this technique possesses the Fellgett
(multiplex) and Connes (accuracy) advantages and it conceptually mimics that of
pulsed nuclear magnetic resonance. We also establish a novel benchmark to
compare accuracy of the different approaches of microwave resonator
measurements. This shows that the present method have similar accuracy to the
existing ones.",1505.06863v1
2015-05-26,Spectral Engineering with Coupled Microcavities: Active Control of Resonant Mode-Splitting,"Optical mode-splitting is an efficient tool to shape and fine-tune the
spectral response of resonant nanophotonic devices. The active control of
mode-splitting, however, is either small or accompanied by undesired resonance
shifts, often much larger than the resonance-splitting. We report a control
mechanism that enables reconfigurable and widely tunable mode-splitting while
efficiently mitigating undesired resonance shifts. This is achieved by actively
controlling the excitation of counter-traveling modes in coupled resonators.
The transition from a large splitting (80 GHz) to a single-notch resonance is
demonstrated using low power microheaters (35 mW). We show that the spurious
resonance-shift in our device is only limited by thermal crosstalk and
resonance-shift-free splitting control may be achieved.",1505.07097v1
2015-06-04,Resonant infiltration of an opal: reflection lineshape and contribution from in-depth regions,"We analyze the resonant variation of the optical reflection on an infiltrated
artificial opal made of transparent nanospheres. The resonant infiltration is
considered as a perturbation in the frame of a previously described
one-dimensional model based upon a stratified effective index. We show that for
a thin slice of resonant medium, the resonant response oscillates with the
position of this slice. We derive that for adequate conditions of incidence
angle, this spatially oscillating behavior matches the geometrical periodicity
of the opal, and hence the related density of resonant infiltration. Close to
these matching conditions, the resonant response of the global infiltration
varies sharply in amplitude and shape with the incidence angle and
polarization. The corresponding resonant reflection originates from a rather
deep infiltration, up to several wavelengths or layers of spheres. Finally, we
discuss the relationship between the present predictions and our previous
observations on an opal infiltrated with a resonant vapor.",1506.01521v1
2015-08-31,Dissipation and resonance frequency shift of a resonator magnetically coupled to a semiclassical spin,"We calculate the change of the properties of a resonator, when coupled to a
semiclassical spin by means of the magnetic field. Starting with the Lagrangian
of the complete system, we provide an analytical expression for the linear
response function for the motion of the resonator, thereby considering the
influence of the resonator on the spin and vice versa. This analysis shows that
the resonance frequency and effective dissipation factor can change
significantly due to the relaxation times of the spin. We first derive this for
a system consisting of a spin and mechanical resonator and thereafter apply the
same calculations to an electromagnetic resonator. Moreover, the applicability
of the method is generalized to a resonator coupled to general two and more
level systems, providing a key to understand some of the problems of two level
systems in quantum devices.",1508.07972v2
2015-09-06,Creating a zero-order resonator using an optical surface transformation,"A novel zero-order resonator has been designed by an optical surface
transformation (OST) method. The resonator proposed here has many novel
features. Firstly, the mode volume can be very small (e.g. in the subwavelength
scale). Secondly, the resonator is open (no reflecting walls are utilized) and
resonant effects can be found in a continuous spectrum (i.e. a continuum of
eigenmodes). Thirdly, we only need one homogenous medium to realize the
proposed resonator. The shape of the resonator can be a ring structure of
arbitrary shape. In addition to the natural applications (e.g. optical storage)
of an optical resonator, we also suggest some other applications of our novel
optical open resonator (e.g. power combination, squeezing electromagnetic
energy in the free space).",1509.02552v1
2015-09-16,Fano resonance in a normal metal/ferromagnet-quantum dot-superconductor device,"We investigate theoretically the Andreev transport through a quantum dot
strongly coupled with a normal metal/ferromagnet and a superconductor
(N/F-QD-S), in which the interplay between the Kondo resonance and the Andreev
bound states (ABSs) has not been clearly clarified yet. Here we show that the
interference between the Kondo resonance and the ABSs modifies seriously the
lineshape of the Kondo resonance, which manifests as a Fano resonance. The
ferromagnetic lead with spin-polarization induces an effective field, which
leads to splitting both of the Kondo resonance and the ABSs. The
spin-polarization together with the magnetic field applied provides an
alternative way to tune the lineshape of the Kondo resonances, which is
dependent of the relative positions of the Kondo resonance and of the ABSs.
These results indicate that the interplay between the Kondo resonance and the
ABSs can significantly affect the Andreev transport, which could be tested by
experiments.",1509.04801v1
2016-02-21,"Orbital Feshbach Resonance: A ""Wide"" Narrow Resonance for Higher Transition Temperature Fermi Superfluid","In this letter we show that the recently theoretically predicted and
experimentally observed ""orbital Feshbach resonance"" in alkali-earth-like
Yb-173 atom is a narrow resonance in energy, while it is hundreds Gauss wide in
term of magnetic field strength, taking the advantage that the magnetic moment
difference between the open and closed channels is quite small. Therefore this
is an ideal platform for the experimental realization of a strongly interacting
Fermi superfluid with narrow resonance. We show that the transition temperature
for the Fermi superfluid in this system, especially at the BCS side of the
resonance, is even higher than that in a wide resonance, which is also due to
the narrow character of this resonance. Our results will encourage experimental
efforts to realize Fermi superfluid in the alkali-earth-like Yb-173 system, the
properties of which will be complementary to extensively studied Fermi
superfluids nearby a wide resonance in alkali K-40 and Li-6 systems.",1602.06513v1
2016-03-08,Resonant enhancement of Raman scattering in metamaterials with hybrid electromagnetic and plasmonic resonances,"A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al)
films with the top aluminium layer patterned as an array of circular disk
nanoantennas, is investigated for resonantly enhancing Raman scattering from
C-60 fullerene molecules deposited on the metamaterial. The metamaterial is
designed to have resonant bands due to plasmonic and electromagnetic resonances
at the Raman pump frequency (725 nm) as well as Stokes emission bands. The
Raman scattering from C60 on the metamaterial with resonantly matched bands is
measured to be enhanced by an order of magnitude more than from C60 on
metamaterials with off-resonant absorption bands peaked at 1090 nm. The Raman
pump is significantly enhanced due to the resonance with a propagating surface
plasmon band, while the highly impedance matched electromagnetic resonance is
expected to couple out the Raman emission efficiently. The nature and
hybridization of the plasmonic and electromagnetic resonances to form compound
resonances are investigated by numerical simulations.",1603.02561v1
2016-04-12,Resonant capture of multiple planet systems under dissipation and stable orbital configurations,"Migration of planetary systems caused by the action of dissipative forces may
lead the planets to be trapped in a resonance. In this work we study the
conditions and the dynamics of such resonant trapping. Particularly, we are
interested in finding out whether resonant capture ends up in a long-term
stable planetary configuration. For two planet systems we associate the
evolution of migration with the existence of families of periodic orbits in the
phase space of the three-body problem. The family of circular periodic orbits
exhibits a gap at the 2:1 resonance and an instability and bifurcation at the
3:1 resonance. These properties explain the high probability of 2:1 and 3:1
resonant capture at low eccentricities. Furthermore, we study the resonant
capture of three-planet systems. We show that such a resonant capture is
possible and can occur under particular conditions. Then, from the migration
path of the system, stable three-planet configurations, either symmetric or
asymmetric, can be determined.",1604.03341v1
2016-06-21,On three-dimensional plasmon resonance in elastostatics,"We consider the plasmon resonance for the elastostatic system in
$\mathbb{R}^3$ associated with a very broad class of sources. The plasmonic
device takes a general core-shell-matrix form with the metamaterial located in
the shell. It is shown that the plasmonic device in the literature which
induces resonance in $\mathbb{R}^2$ does not induce resonance in
$\mathbb{R}^3$. We then construct two novel plasmonic devices with suitable
plasmon constants, varying according to the source term or the loss parameter,
which can induce resonances. If there is no core, we show that resonance always
occurs. If there is a core of an arbitrary shape, we show that the resonance
strongly depends on the location of the source. In fact, there exists a
critical radius such that resonance occurs for sources lying within the
critical radius, whereas resonance does not occur for source lying outside the
critical radius. Our argument is based on the variational technique by making
use of the primal and dual variational principles for the elastostatic system,
along with the highly technical construction of the associated perfect plasmon
elastic waves.",1606.06440v1
2016-07-19,Theoretical Investigation of Phonon Polaritons in SiC Micropillar Resonators,"Of late there has been a surge of interest in localised phonon polariton
resonators which allow for sub-diffraction confinement of light in the
mid-infrared spectral region by coupling to optical phonons at the surface of
polar dielectrics. Resonators are generally etched on deep substrates which
support propagative surface phonon polariton resonances. Recent experimental
work has shown that understanding the coupling between localised and
propagative surface phonon polaritons in these systems is vital to correctly
describe the system resonances. In this paper we comprehensively investigate
resonators composed of arrays of cylindrical SiC resonators on SiC substrates.
Our bottom-up approach, starting from the resonances of single, free standing
cylinders and isolated substrates, and exploiting both numerical and analytical
techniques, allows us to develop a consistent understanding of the parameter
space of those resonators, putting on firmer ground this blossoming technology.",1607.05741v1
2016-10-13,Quasi-perfect absorption by sub-wavelength acoustic panels in transmission using accumulation of resonances due to slow sound,"We theoretically and experimentally report sub-wavelength resonant panels for
low-frequency quasi-perfect sound absorption including transmission by using
the accumulation of cavity resonances due to the slow sound phenomenon. The
sub-wavelength panel is composed of periodic horizontal slits loaded by
identical Helmholtz resonators (HRs). Due to the presence of the HRs, the
propagation inside each slit is strongly dispersive, with near-zero phase
velocity close to the resonance of the HRs. In this slow sound regime, the
frequencies of the cavity modes inside the slit are down-shifted and the slit
behaves as a subwavelength resonator. Moreover, due to strong dispersion, the
cavity resonances accumulate at the limit of the bandgap below the resonance
frequency of the HRs. Near this accumulation frequency, simultaneously
symmetric and antisymmetric quasi-critical coupling can be achieved. In this
way, using only monopolar resonators quasi-perfect absorption can be obtained
in a material including transmission.",1610.04645v1
2017-03-31,Resonances for 1d Stark operators,"We consider the Stark operator perturbed by a compactly supported potential
(of a certain class) on the real line. We prove the following results: (a)
upper and lower bounds on the number of resonances in complex discs with large
radii,
  (b) the trace formula in terms of resonances only, (c) all resonances
determine the potential uniquely.",1703.10820v1
2017-08-01,First transneptunian object in polar resonance with Neptune,"Capture in mean motion resonance has been observed in the Solar System for
small objects with prograde as well as retrograde orbits of moderate
inclinations. However, no example of an object with a nearly polar orbit was
known to be in resonance with a planet. In this Letter, we report that the
nearly-polar transneptunian object (471325), nicknamed Niku, is in a 7:9
resonance with Neptune, with a mean lifetime in resonance of 16 +- 11 million
years. While entrance and exit in the 7:9 resonance is caused by close
encounters with Neptune the resonant configuration provides a temporary
protection mechanism against disruptive close encounters with this planet. The
other nearly polar transneptunian objects do not seem to be in resonance with
the planets with the possible exception of 2008 KV42, also known as Drac, that
has a small chance of being in the 8:13 resonance with Neptune.",1708.00346v1
2018-04-09,"Periodic oscillators, isochronous centers and resonance","An oscillator is called isochronous if all motions have a common period. When
the system is forced by a time-dependent perturbation with the same period the
dynamics may change and the phenomenon of resonance can appear. In this
context, resonance means that all solutions are unbounded. The theory of
resonance is well known for the harmonic oscillator and we extend it to
nonlinear isochronous oscillators.",1804.03127v2
2018-04-29,Dynamic portrait of the retrograde 1:1 mean motion resonance,"Asteroids in mean motion resonances with giant planets are common in the
solar system, but it was not until recently that several asteroids in
retrograde mean motion resonances with Jupiter and Saturn were discovered. A
retrograde co-orbital asteroid of Jupiter, 2015 BZ509 is confirmed to be in a
long-term stable retrograde 1:1 mean motion resonance with Jupiter, which gives
rise to our interests in its unique resonant dynamics. In this paper, we
investigate the phase-space structure of the retrograde 1:1 resonance in detail
within the framework of the circular restricted three-body problem. We
construct a simple integrable approximation for the planar retrograde resonance
using canonical contact transformation and numerically employ the averaging
procedure in closed form. The phase portrait of the retrograde 1:1 resonance is
depicted with the level curves of the averaged Hamiltonian. We thoroughly
analyze all possible librations in the co-orbital region and uncover a new
apocentric libration for the retrograde 1:1 resonance inside the planet's
orbit. We also observe the significant jumps in orbital elements for outer and
inner apocentric librations, which are caused by close encounters with the
perturber.",1804.10893v1
2018-11-01,Enhancement of Fluctuation-Induced Electromagnetic Phenomena in dynamically nonequilibrium systems at Resonant Photon Emission,"We study the resonances in Casimir friction, radiative heat transfer and heat
generation for two plates sliding relative to each other. Resonances have a
different origin in the frequency range of the \textit{normal} (NDE) and
\textit{anomalous} (ADE) Doppler effect. In the frequency range of NDE,
resonances are associated with resonant photon tunnelling between surface
phonon/plasmon polaritons of plates. For two identical plates, such resonances
exist only at a relative sliding velocity $v=0$. However, for different plates
such resonance can exist at $v\neq 0$. In the frequency range of ADE,
resonances are associated with the creation of excitations in both plates.
While in the frequency range of NDE the photon emission rate has an upper
limit, in the frequency range of ADE, the photon emission rate can diverge even
in the presence of dissipation in the system. We consider resonances for the
identical and different sliding plates. We discuss the possibility to detect
Casimir friction with its limiting case of quantum friction using an atomic
force microscope in graphene structures.",1811.00888v1
2019-05-20,Coupling Matrix Representation of Nonreciprocal Filters Based on Time Modulated Resonators,"This paper addresses the analysis and design of non-reciprocal filters based
on time modulated resonators. We analytically show that time modulating a
resonator leads to a set of harmonic resonators composed of the unmodulated
lumped elements plus a frequency invariant element that accounts for
differences in the resonant frequencies. We then demonstrate that harmonic
resonators of different order are coupled through non-reciprocal admittance
inverters whereas harmonic resonators of the same order couple with the
admittance inverter coming from the unmodulated filter network. This coupling
topology provides useful insights to understand and quickly design
non-reciprocal filters and permits their characterization using an
asynchronously tuned coupled resonators network together with the coupling
matrix formalism. Two designed filters, of orders three and four, are
experimentally demonstrated using quarter wavelength resonators implemented in
microstrip technology and terminated by a varactor on one side. The varactors
are biased using coplanar waveguides integrated in the ground plane of the
device. Measured results are found to be in good agreement with numerical
results, validating the proposed theory.",1905.08340v1
2020-07-22,Mathematical analysis of plasmon resonances for curved nanorods,"We investigate plasmon resonances for curved nanorods which present
anisotropic geometries. We analyze quantitative properties of the plasmon
resonance and its relationship to the metamaterial configurations and the
anisotropic geometries of the nanorods. Based on delicate and subtle asymptotic
and spectral analysis of the layer potential operators, particularly the
Neumann-Poincar\'e operators, associated with anisotropic geometries, we derive
sharp asymptotic formulae of the corresponding scattering field in the
quasi-static regime. By carefully analyzing the asymptotic formulae, we
establish sharp conditions that can ensure the occurrence of the plasmonic
resonance. The resonance conditions couple the metamaterial parameters, the
wave frequency and the nanorod geometry in an intricate but elegant manner. We
provide thorough resonance analysis by studying the wave fields both inside and
outside the nanorod. Furthermore, our quantitative analysis indicates that
different parts of the nanorod induce varying degrees of resonance.
Specifically, the resonant strength at the two end-parts of the curved nanorod
is more outstanding than that of the facade-part of the nanorod. This paper
presents the first theoretical study on plasmon resonances for nanostructures
within anisotropic geometries.",2007.11181v1
2014-03-30,"Resonance chains in open systems, generalized zeta functions and clustering of the length spectrum","In many non-integrable open systems in physics and mathematics resonances
have been found to be surprisingly ordered along curved lines in the complex
plane. In this article we provide a unifying approach to these resonance chains
by generalizing dynamical zeta functions. By means of a detailed numerical
study we show that these generalized zeta functions explain the mechanism that
creates the chains of quantum resonance and classical Ruelle resonances for
3-disk systems as well as geometric resonances on Schottky surfaces. We also
present a direct system-intrinsic definition of the continuous lines on which
the resonances are strung together as a projection of an analytic variety.
Additionally, this approach shows that the existence of resonance chains is
directly related to a clustering of the classical length spectrum on multiples
of a base length. Finally, this link is used to construct new examples where
several different structures of resonance chains coexist.",1403.7771v2
2017-01-17,Longitudinal near-field coupling between acoustic resonators grafted onto a waveguide,"We investigate longitudinal near-field coupling between acoustic resonators
grafted onto a waveguide. Experiments are performed in the audible range with a
simple acoustic system composed of a finite aperiodic sequence of air
resonators. Transmission typically shows a zero around a resonance frequency of
a single resonator, as is well known. When two identical resonators are brought
in close proximity, however, we observe that longitudinal near-field coupling
strongly influences the acoustic transmission. When the separation between
resonators is increased so that they can be considered in the far field of one
another, we further observe the appearance of Fano-like transmission profiles.
We explain this observation by the formation of locally resonant Fabry-Perot
interferometers from every pair of resonators. All experimental results are
compared to three-dimensional finite element analysis of the acoustic system.",1701.04654v1
2011-11-01,Feshbach resonances and their interaction in light scattering off photonic crystal slabs,"The concept of Feshbach resonances developed for quantum mechanical
scattering is applied in the analysis of classical light scattering off
photonic crystal slabs. It is shown that this concept can be realized almost
perfectly in these systems. As an application guided-mode resonances in the
grating waveguide structure (GWS) are studied in detail. Using simple resonance
dominance approximation the characteristic properties of isolated Feshbach
resonances in light scattering are exhibited. Formation and interaction of
overlapping resonances are investigated. The relevant parameters of the GWS are
identified which control the shape of the reflectivity of interacting
resonances as well as the enhancement of the electromagnetic field. The
differences in the properties of TE and TM resonances is emphasized for both
isolated and interacting resonances.",1111.0208v1
2011-11-01,Identifying Non-Resonant Kepler Planetary Systems,"The Kepler mission has discovered a plethora of multiple transiting planet
candidate exosystems, many of which feature putative pairs of planets near mean
motion resonance commensurabilities. Identifying potentially resonant systems
could help guide future observations and enhance our understanding of planetary
formation scenarios. We develop and apply an algebraic method to determine
which Kepler 2-planet systems cannot be in a 1st-4th order resonance, given the
current, publicly available data. This method identifies when any potentially
resonant angle of a system must circulate. We identify and list 70
near-resonant systems which cannot actually reside in resonance, assuming a
widely-used formulation for deriving planetary masses from their observed radii
and that these systems do not contain unseen bodies that affect the
interactions of the observed planets. This work strengthens the argument that a
high fraction of exoplanetary systems may be near resonance but not actually in
resonance.",1111.0299v1
2011-11-15,Resonances in Extreme Mass-Ratio Inspirals: Asymptotic and Hyperasymptotic Analysis,"An expected source of gravitational waves for future detectors in space are
the inspirals of small compact objects into much more massive black holes.
These sources have the potential to provide a wealth of information about
astronomy and fundamental physics. On short timescales the orbit of the small
object is approximately geodesic. Generic geodesics for a Kerr black hole
spacetime have a complete set of integrals and can be characterized by three
frequencies of the motion. Over the course of an inspiral, a typical system
will pass through resonances where two of these frequencies become
commensurate. The effect of the resonance will be to alter significantly the
rate of inspiral for the duration of the resonance. Understanding the impact of
these resonances on gravitational wave phasing is important to detect and
exploit these signals for astrophysics and fundamental physics. Two
differential equations that might describe the passage of an inspiral through
such a resonance are investigated. These differ depending on whether it is the
phase or the frequency components of a Fourier expansion of the motion that are
taken to be continuous through the resonance. Asymptotic and hyperasymptotic
analysis are used to find the late-time analytic behavior of the solution for a
system that has passed through a resonance. Linearly growing (weak resonances)
or linearly decaying (strong resonances) solutions are found depending on the
strength of the resonance. In the weak-resonance case, frequency resonances
leave an imprint (a resonant memory) on the gravitational frequency evolution.
The transition between weak and strong resonances is characterized by a
square-root singularity, and as one approaches this transition from above, the
solutions to the frequency resonance equation bunch up into families
exponentially fast.",1111.3605v1
2014-06-08,Storage and on-demand release of microwaves using superconducting resonators with tunable coupling,"We present a system which allows to tune the coupling between a
superconducting resonator and a transmission line. This storage resonator is
addressed through a second, coupling resonator, which is frequency-tunable and
controlled by a magnetic flux applied to a superconducting quantum interference
device (SQUID). We experimentally demonstrate that the lifetime of the storage
resonator can be tuned by more than three orders of magnitude. A field can be
stored for 18 {\mu}s when the coupling resonator is tuned off resonance and it
can be released in 14 ns when the coupling resonator is tuned on resonance. The
device allows capture, storage, and on-demand release of microwaves at a
tunable rate.",1406.2005v1
2016-05-02,Super-Resonant Intracavity Coherent Absorption,"The capability of optical resonators to extend the effective radiation-matter
interaction length originates from a multipass effect, hence is intrinsically
limited by the resonator quality factor. Here, we show that this constraint can
be overcome by combining the concepts of resonant interaction and coherent
perfect absorption. We demonstrate and investigate super-resonant coherent
absorption in a coupled Fabry-Perot-ring cavity structure. At the FP resonant
wavelengths, the described phenomenon gives rise to split modes with a
nearly-transparent peak and a peak whose transmission is exceptionally
sensitive to the intracavity loss. For small losses, the effective interaction
pathlength of these modes is proportional respectively to the ratio and the
product of the individual finesse coefficients of the two resonators. The
results presented extend the conventional definition of resonant absorption and
point to a way of circumventing the technological limitations of
ultrahigh-quality resonators in spectroscopy and optical sensing schemes",1605.00389v2
2016-05-02,Three types of nonlinear resonances,"We analyse different types of nonlinear resonances in a weakly damped Duffing
oscillator using bifurcation theory techniques. In addition to (i) odd
subharmonic resonances found on the primary branch of symmetric periodic
solutions with the forcing frequency and (ii) even subharmonic resonances due
to symmetry-broken periodic solutions that bifurcate off the primary branch and
also oscillate at the forcing frequency, we uncover (iii) novel resonance type
due to isolas of periodic solutions that are not connected to the primary
branch. These occur between odd and even resonances, oscillate at a fraction of
the forcing frequency, and give rise to a complicated resonance `curve' with
disconnected elements and high degree of multistability. We use bifurcation
continuation to compute resonance tongues in the plane of the forcing frequency
vs. the forcing amplitude for different but fixed values of the damping rate.
In this way, we demonstrate that identified here isolated resonances explain
the intriguing structure of ""patchy tongues"" observed for week damping and link
it to a seemingly unrelated phenomenon of ""bifurcation superstructure""
described for moderate damping.",1605.00858v2
2016-05-12,Resonance Beyond Frequency-Matching,"Resonance, defined as the oscillation of a system when the temporal frequency
of an external stimulus matches a natural frequency of the system, is important
in both fundamental physics and applied disciplines. However, the spatial
character of oscillation is not considered in the definition of resonance. In
this work, we reveal the creation of spatial resonance when the stimulus
matches the space pattern of a normal mode in an oscillating system. The
complete resonance, which we call multidimensional resonance, is a combination
of both the spatial and the conventionally defined (temporal) resonance and can
be several orders of magnitude stronger than the temporal resonance alone. We
further elucidate that the spin wave produced by multidimensional resonance
drives considerably faster reversal of the vortex core in a magnetic nanodisk.
Our findings provide insight into the nature of wave dynamics and open the door
to novel applications.",1605.03649v2
2016-08-03,Probing the resonance of Dirac particle by the application of complex momentum representation,"Resonance plays critical roles in the formation of many physical phenomena,
and several methods have been developed for the exploration of resonance. In
this work, we propose a new scheme for resonance by solving the Dirac equation
in complex momentum representation, in which the resonant states are exposed
clearly in complex momentum plane and the resonance parameters can be
determined precisely without imposing unphysical parameters. Combining with the
relativistic mean-field theory, this method is applied to probe the resonances
in $^{120}$Sn with the energies, widths, and wavefunctions being obtained.
Comparing with other methods, this method is not only very effective for narrow
resonances, but also can be reliably applied to broad resonances.",1608.01046v1
2016-08-17,Electron Spin Resonance at the Level of 10000 Spins Using Low Impedance Superconducting Resonators,"We report on electron spin resonance (ESR) measurements of phosphorus donors
localized in a 200 square micron area below the inductive wire of a lumped
element superconducting resonator. By combining quantum limited parametric
amplification with a low impedance microwave resonator design we are able to
detect around 20000 spins with a signal-to-noise ratio (SNR) of 1 in a single
shot. The 150 Hz coupling strength between the resonator field and individual
spins is significantly larger than the 1 - 10 Hz coupling rates obtained with
typical coplanar waveguide resonator designs. Due to the larger coupling rate,
we find that spin relaxation is dominated by radiative decay into the resonator
and dependent upon the spin-resonator detuning, as predicted by Purcell.",1608.05130v2
2016-08-27,"Fano resonances in dielectric, metallic and metamaterial photonic structures","We investigate numerically Fano resonances excited in periodic arrays of
dielectric, metallic and left-handed cylinders. Of particular interest are Fano
resonances excited in the linear array of cylin- ders. We analyze spatial
distribution and symmetry of electromagnetic field and discuss the relation
between observed Fano resonances and frequency spectra of two-dimensional
arrays of cylinders.",1608.07716v1
2016-12-02,Probing the resonance in the Dirac equation with quadruple-deformed potentials by complex momentum representation method,"Resonance plays critical roles in the formation of many physical phenomena,
and many techniques have been developed for the exploration of resonance. In a
recent letter [Phys. Rev. Lett. 117, 062502 (2016)], we proposed a new method
for probing single-particle resonances by solving the Dirac equation in complex
momentum representation for spherical nuclei. Here, we extend this method to
deformed nuclei with theoretical formalism presented. We elaborate numerical
details, and calculate the bound and resonant states in $^{37}$Mg. The results
are compared with those from the coordinate representation calculations with a
satisfactory agreement. In particular, the present method can expose clearly
the resonant states in complex momentum plane and determine precisely the
resonance parameters for not only narrow resonances but also broad resonances
that were difficult to obtain before.",1612.00527v1
2016-12-15,Testing universality of Efimov physics across broad and narrow Feshbach resonances,"Efimov physics is a universal phenomenon arising in quantum three-body
systems. For systems with resonant two-body interactions, Efimov predicted an
infinite series of three-body bound states with geometric scaling symmetry.
These Efimov states were first observed in cold Cs atoms and have since been
reported in a variety of atomic systems. While theories predict non-universal
behavior for narrow Feshbach resonances, experiments on Efimov resonances are
so far consistent with predictions based on universal theories. Here we
directly compare the Efimov spectra in a $^6$Li-$^{133}$Cs mixture near two
Feshbach resonances which are very different in their resonance strengths but
otherwise almost identical. Our result shows a clear dependence of the Efimov
resonance positions on Feshbach resonance strength and a clear departure from
the universal prediction for the narrow Feshbach resonance.",1612.05169v1
2017-07-25,Molecular predissociation resonances below an energy level crossing,"We study the resonances of $2\times 2$ systems of one dimensional
Schr\""odinger operators which are related to the mathematical theory of
molecular predissociation. We determine the precise positions of the resonances
with real parts below the energy where bonding and anti-bonding potentials
intersect transversally. In particular, we find that imaginary parts (widths)
of the resonances are exponentially small and that the indices are determined
by Agmon distances for the minimum of two potentials.",1707.07963v1
2017-10-24,Universal Feature in Optical Control of a p-wave Feshbach Resonance,"In this Letter we report the experimental results on optical control of a
p-wave Feshbach resonance, by utilizing a laser driven bound-to-bound
transition to shift the energy of closed channel molecule. The magnetic field
location for p-wave resonance as a function of laser detuning can be captured
by a simple formula with essentially one parameter, which describes how
sensitive the resonance depends on the laser detuning. The key result of this
work is to demonstrate, both experimentally and theoretically, that the ratio
between this parameter for $m=0$ resonance and that for $m=\pm 1$ resonance, to
large extent, is universal. We also show that this optical control can create
intriguing situations where interesting few- and many-body physics can occurs,
such as a p-wave resonance overlapping with an s-wave resonance or three p-wave
resonances being degenerate.",1710.08636v3
2018-09-13,Improving the read-out of the resonance frequency of nanotube mechanical resonators,"We report on an electrical detection method of ultrasensitive carbon nanotube
mechanical resonators. The noise floor of the detection method is reduced using
a RLC resonator and an amplifier based on a high electron mobility transistor
cooled at 4.2 K. This allows us to resolve the resonance frequency of nanotube
resonators with an unprecedented quality. We show that the noise of the
resonance frequency measured at 4.2 K is limited by the resonator itself, and
not by the imprecision of the measurement. The Allan deviation reaches ~10^-5
at 125 ms integration time. When comparing the integration time dependence of
the Allan deviation to a power law, the exponent approaches ~1/4. The Allan
deviation might be limited by the diffusion of particles over the surface of
the nanotube. Our work holds promise for mass spectrometry and surface science
experiments based on mechanical nano-resonators.",1809.04915v1
2019-06-30,Computing resonant modes of circular cylindrical resonators by vertical mode expansions,"Open subwavelength cylindrical resonators of finite height are widely used in
various photonics applications. Circular cylindrical resonators are
particularly important in nanophotonics, since they are relatively easy to
fabricate and can be designed to exhibit different resonance effects. In this
paper, an efficient and robust numerical method is developed for computing
resonant modes of circular cylinders which may have a few layers and may be
embedded in a layered background. The resonant modes are complex-frequency
outgoing solutions of the Maxwell's equations with no sources or incident
waves. The method uses field expansions in one-dimensional (1D) ``vertical''
modes to reduce the original three-dimensional eigenvalue problem to 1D
problems, and uses Chebyshev pseudospectral method to compute the 1D modes and
set up the discretized eigenvalue problem. In addition, a new iterative scheme
is developed so that the 1D nonlinear eigenvalue problems can be reliably
solved. For metallic cylinders, the resonant modes are calculated based on
analytic models for the dielectric functions of metals. The method is validated
by comparisons with existing numerical results, and it is also used to explore
subwavelength dielectric cylinders with high-$Q$ resonances and analyze gold
nanocylinders.",1907.00340v1
2019-06-30,Multi-resonant high-Q plasmonic metasurfaces,"Resonant metasurfaces are devices composed of nanostructured sub-wavelength
scatterers that generate narrow optical resonances, enabling applications in
filtering, nonlinear optics, and molecular fingerprinting. It is highly
desirable for these applications to incorporate such devices with multiple,
high-quality-factor resonances; however, it can be challenging to obtain more
than a pair of narrow resonances in a single plasmonic surface. Here, we
demonstrate a multi-resonant metasurface that operates by extending the
functionality of surface lattice resonances, which are the collective responses
of arrays of metallic nanoparticles. This device features a series of
resonances with high quality factors (Q ~ 40), an order of magnitude larger
than what is typically achievable with plasmonic nanoparticles, as well as a
narrow free spectral range. This design methodology can be used to better
tailor the transmission spectrum of resonant metasurfaces and represents an
important step towards the miniaturization of optical devices.",1907.00458v3
2019-07-17,Magneto-optical resonances in fluorescence from sodium D2 manifold,"We report on magneto-optical resonances observed in sodium fluorescence from
D2 manifold with an intensity modulated light. Fluorescence resonances are
measured in the perpendicular and backward directions to the light propagation,
in laboratory experiments using a sodium cell containing neon buffer gas.
Properties of these resonances are studied by varying the magnetic field at
fixed light modulation frequency, and vice-versa. Modulation with low-duty
cycle shows higher-harmonic resonances of the modulation frequency and
sub-harmonic resonances of the Larmor frequency. A dark resonance with maximum
amplitude for laser wavelength closer to the crossover peak is observed. The
origin of this dark resonance observed in Na D2 line is discussed using a
theoretical model. Present study is aimed towards improving the understanding
of magneto-optical resonances for remote magnetometry applications with
mesospheric sodium.",1907.07701v2
2019-07-22,Multiplanet systems in inviscid discs can avoid forming resonant chains,"Convergent migration involving multiple planets embedded in a viscous
protoplanetary disc is expected to produce a chain of planets in mean motion
resonances, but the multiplanet systems observed by the Kepler spacecraft are
generally not in resonance. We demonstrate that under equivalent conditions,
where in a viscous disc convergent migration will form a long-term stable
system of planets in a chain of mean motion resonances, migration in an
inviscid disc often produces a system which is highly dynamically unstable. In
particular, if planets are massive enough to significantly perturb the disc
surface density and drive vortex formation, the smooth capture of planets into
mean motion resonances is disrupted. As planets pile up in close orbits, not
protected by resonances, close encounters increase the probability of
planet-planet collisions, even while the gas disc is still present. While
inviscid discs often produce unstable non-resonant systems, stable, closely
packed, non-resonant systems can also be formed. Thus, when examining the
expectation for planet migration to produce planetary systems in mean motion
resonances, the effective turbulent viscosity of the protoplanetary disc is a
key parameter.",1907.09313v1
2019-09-18,Efficient Photonic Crystal Parametric Source harnessing high-Q resonances,"A new tuning mechanism is introduced in high-Q multimode photonic crystal
resonators allowing to harness the resonant enhancement of the parametric
resonance systematically. As a consequence, ultra-efficient stimulated and
spontaneous Four Wave Mixing at continuous microWatt pumping levels are
observed, and the scaling with Q is demonstrated. Experimental results are in
perfect agreement with an analytical model without fitting parameters.",1909.08717v1
2019-09-22,Some properties of threshold eigenstates and resonant states of discrete Schrödinger operators,"In this note, we study some properties of threshold resonant states or
threshold eigenfunctions for discrete Schr\""odinger operators. We mainly prove
two theorems. First, we prove that resonant states at the elliptic threshold
have the same asymptotic expansion as the continuous Schr\""odinger operator.
Second, we prove absence of resonant states at hyperbolic thresholds",1909.10014v1
2020-12-05,On Periodical Damping Ratio of a Controlled Dynamical System with Parametric Resonances,"This report provides an interpretation on the periodically varying damping
ratio of a dynamical system with direct control of oscillation or vibration
damping. The principal parametric resonance of the system and a new type of
parametric resonance, named ""zero-th order"" parametric resonance, are
investigated by using the method of multiple scales to find approximate,
analytical solutions of the system, which provide an interpretation on such
damping variations.",2012.02932v1
2012-05-22,Carbon nanotubes: Nonlinear high-Q resonators with strong coupling to single-electron tunneling,"Carbon nanotubes (CNTs) are nonlinear high-Q resonators with strong coupling
to single-electron tunneling. We begin by describing several methods to detect
the flexural motion of a CNT resonator. Next, we illustrate how single-electron
tunneling in quantum dot CNT resonators leads to sharp dips in the mechanical
resonance frequency and significant damping. We discuss four different
contributions to the nonlinear oscillation of a CNT resonator: beam-like
mechanical nonlinearity, nonlinearity due to gate-induced mechanical tension,
electrostatic nonlinearity, and nonlinearity due to single-electron tunneling,
and provide quantitative estimates of their strengths. Finally, we show how the
large response of the resonance frequency of a CNT resonator to a change in
gate voltage or tension makes CNT resonators ideally suited for parametric
excitation and for studying the coupling between different mechanical modes.",1205.4921v1
2017-05-16,Resonant lattice Kerker effect in metasurfaces with electric and magnetic optical responses,"To achieve efficient light control at subwavelength dimensions, plasmonic and
all-dielectric nanoparticles have been utilized both as a single element as
well as in the arrays. Here we study 2D periodic nanoparticle arrays
(metasurfaces) that support lattice resonances near the Rayleigh anomaly due to
the electric dipole (ED) and magnetic dipole (MD) resonant coupling between the
nanoparticles. Silicon and core-shell particles are considered. We demonstrate
for the first time that, choosing of lattice periods independently in each
mutual-perpendicular direction, it is possible to achieve a full overlap
between the ED-lattice resonance and MD resonances of nanoparticles in certain
spectral range and to realize the resonant lattice Kerker effect (resonant
suppression of the scattering or reflection). At the effect conditions, the
strong suppression of light reflectance in the structure is appeared due to
destructive interference between electromagnetic waves scattered by ED and MD
moments of every nanoparticle in the backward direction with respect to the
incident light wave. Influence of the array size on the revealed reflectance
and transmittance behavior is discussed. The resonant lattice Kerker effect
based on the overlap of both ED and MD lattice resonances is also demonstrated.",1705.05533v1
2018-07-17,Nature of isoscalar dipole resonances in heavy nuclei,"Isoscalar dipole nuclear response reveals the low- and high-energy
resonances. The nature of isoscalar dipole resonances in heavy spherical nuclei
is studied by using the translation-invariant kinetic model of small
oscillations of finite Fermi systems. Calculations of the velocity field at the
centroid energy show a pure vortex character of the low-energy isoscalar dipole
resonance in spherical nuclei and confirm the anisotropic compression character
of the high-energy one. The evolution of the velocity field in dependence on
the excitation energy of the nucleus within the resonance width is studied. It
is found that the low-energy isoscalar dipole resonance retains a vortex
character while with increasing energy this collective excitation also involves
compression. The high-energy resonance keeps the compression character with a
change in the excitation energy within the resonance width but the
compression-expansion region of the velocity field related to this resonance
shifts inside the nucleus.",1807.06407v1
2018-07-18,Coupled-Ring Resonance and Unitary Groups,"The group-theoretic content of photonic coupled microrings resonance
phenomena is shown, in particular, an interesting emergence of pseudo-unitary
group. The application to the resonance condition in a tri-microring
configuration is solved exactly. A practical application of this work will be
in the resonance frequency tuning based on the coupling coefficient, in
particular, the Mach-Zehnder interferometer approach was analyzed for the
coupling modulation.",1807.06773v1
2019-02-28,"A compact structure for realizing Lorentzian, Fano and EIT resonance lineshapes in a microring resonator","Microring resonators, as a fundamental building block of photonic integrated
circuits, have been well developed into numerous functional devices, whose
performances are strongly determined by microring's resonance lineshapes. We
propose a compact structure to reliably realize Lorentzian, Fano, and
electromagnetically induced transparency (EIT) resonance lineshapes in a
microring. By simply inserting two air-holes in the side-coupled waveguide of a
microring, a Fabry-Perot (FP) resonance is involved to couple with microring's
resonant modes, showing Lorentzian, Fano, and EIT lineshapes over one free
spectral range of the FP resonance. The quality factors, extinction ratios, and
slope rates in different lineshapes are discussed. At microring's specific
resonant wavelength, the lineshape could be tuned among these three types by
controlling the FP cavity's length. Experiment results verify the theoretical
analysis well and represent Fano lineshapes with extinction ratios of about 20
dB and slope rates over 280 dB/nm. The reliably and flexibly tunable lineshapes
in the compact structure have potentials to improve microring-based devices and
expand their application scopes.",1902.10902v1
2019-03-05,Efficient self-resonance instability from axions,"It was recently shown that a coherent oscillation of an axion can cause an
efficient parametric resonance, leading to a prominent emission of the
gravitational waves (GWs). In this paper, conducting the Floquet analysis, we
investigate the parametric resonance instability, which potentially triggers
the emission of the GWs from axions. Such a resonance instability takes place,
when the time evolution of the background field significantly deviates from the
harmonic oscillation. Therefore, the resonance instability cannot be described
by the Mathieu equation, whose stability/instability chart is well known. In
this paper, introducing an explicitly calculable parameter $\tilde{q}$, which
can be used to classify different types of the parametric resonance described
by the general Hill's equation, we investigate the stability/instability chart
for the general Hill's equation. This can also apply to the case where the
background oscillation is anharmonic. We show that the flapping resonance
instability, which takes place for $\tilde{q}=O(1)$, typically leads to the
most significant growth of the inhomogeneous modes among the self-resonance
instability. We also investigate whether the flapping resonance takes place for
the cosine potential or not.",1903.02119v2
2019-03-29,Structure of resonances in a square well potential,"We study the structure of resonances as derived from the exactly solvable
Lippmann-Schwinger equation for a one-dimensional square well potential. Within
this framework, we discuss the concept of resonance form factors, and the
relation of the corresponding spatial densities to ``resonance wave
functions''.",1904.00823v1
2019-11-16,Post- versus pre-resonance characteristics of axially excited chiral sculptured thin films,"Axially excited chiral sculptured thin films (STFs) are shown to exhibit the
circular Bragg phenomenon in the pre-resonant (long-wavelength) regime but not
in some parts of the post-resonant (short-wavelength) regime. Chiral STFs act
as very good polarization-independent reflectors in the vicinity of material
resonances in the latter regime.",1911.06984v1
2020-03-11,Mitigation of Resonances in Sinuous Antennas,"Sinuous antennas are capable of producing ultra-wideband radiation with
polarization diversity. Such a capability makes the sinuous antenna an
attractive candidate for wideband polarimetric radar applications.
Additionally, the ability of the sinuous antenna to be implemented as a planar
structure makes it a good fit for close in sensing applications such as ground
penetrating radar. However, recent literature has shown the sinuous antenna to
suffer from resonances which degrade performance. Such resonances produce late
time ringing which is particularly troubling for pulsed close in sensing
applications. The resonances occur in two forms: log-periodic resonances on the
arms, and a resonance due to the outer truncation of the sinuous antenna
geometry. A detailed investigation as to the correlation between the
log-periodic resonances and the sinuous antenna design parameters indicates the
resonances may be mitigated by selecting appropriate parameters. In addition,
the resonance due to truncation may be mitigated by moving the circular
truncation to the tip of the outermost cell which has advantages over the
clipping method proposed in the literature.",2003.05072v1
2020-06-11,Feshbach Resonances in an Erbium-Dysprosium Dipolar Mixture,"We report on the observation of heteronuclear magnetic Feshbach resonances in
several isotope mixtures of the highly magnetic elements erbium and dysprosium.
Among many narrow features, we identify two resonances with a width greater
than one Gauss. We characterize one of these resonances, in a mixture of
$^{168}$Er and $^{164}$Dy, in terms of loss rates and elastic cross section,
and observe a temperature dependence of the on-resonance loss rate suggestive
of a universal scaling associated with broad resonances. Our observations hold
promise for the use of such a resonance for tuning the interspecies scattering
properties in a dipolar mixture. We further compare the prevalence of narrow
resonances in an $^{168}$Er-$^{164}$Dy mixture to the single-species case, and
observe an increased density of resonances in the mixture.",2006.06456v1
2020-10-24,Octave-Tunable Magnetostatic Wave YIG Resonators on a Chip,"We have designed, fabricated, and characterized magnetostatic wave (MSW)
resonators on a chip. The resonators are fabricated by patterning
single-crystal yttrium iron garnet (YIG) film on a gadolinium gallium garnet
(GGG) substrate and excited by loop-inductor transducers. We achieved this
technology breakthrough by developing a YIG film etching process and
fabricating thick aluminum coplanar waveguide (CPW) inductor loop around each
resonator to individually address and excite MSWs. At 4.77 GHz, the 0.68 square
mm resonator achieves a quality factor Q > 5000 with a bias field of 987 Oe. We
also demonstrate YIG resonator tuning by more than one octave from 3.63 to 7.63
GHz by applying an in-plane external magnetic field. The measured quality
factor of the resonator is consistently over 3000 above 4 GHz. The
micromachining technology enables the fabrication of multiple single- and
two-port YIG resonators on the same chip with all resonators demonstrating
octave tunability and high Q .",2010.12732v1
2021-05-22,Fully symmetric controllable integrated three-resonator photonic molecule,"Photonic molecules can be used to realize complex optical energy states and
modes, analogous to those found in molecules, with properties useful for
applications like spectral engineering and quantum optics. It is desirable to
implement photonic molecules using high quality factor photonic integrated ring
resonators due to their narrow atom-like spectral resonance, tunability, and
the ability to scale the number of resonators on a photonic circuit. However,
to take full advantage of molecule spectral complexity and tuning degree of
freedom, resonator structures should have full symmetry in terms of
inter-resonator coupling and resonator-waveguide coupling as well as
independent resonance tuning, and low power dissipation operation, in a
scalable integration platform. To date, photonic molecule symmetry has been
limited to dual- and triple-cavity geometries coupled to single- or
dual-busses, and resonance tuning limited to dual resonator molecules. In this
paper, we demonstrate a three-resonator photonic molecule, consisting of
symmetrically coupled 8.11 million intrinsic Q silicon nitride rings, where
each ring is coupled to the other two rings. The resonance of each ring, and
that of the collective molecule, is controlled using low power dissipation,
monolithically integrated thin-film lead zirconate titanate (PZT) actuators
that are integrated with the ultra-low loss silicon nitride resonators. This
performance is achieved without undercut waveguides, yielding the highest Q to
date for a PZT controlled resonator. This advance leads to full control of
complex photonic molecule resonance spectra and splitting in a wafer-scale
integration platform. The resulting six tunable supermodes can be fully
controlled, including degeneracy, location and splitting as well as designed by
a model that can accurately predict the energy modes and transmission spectrum
and tunable resonance splitting.",2105.10815v1
2021-06-25,Resonance refraction and neutrino oscillations,"The refraction index and matter potential depend on neutrino energy and this
dependence has a resonance character associated to the production of the
mediator in the $s-$channel. For light mediators and light particles of medium
(background) the resonance can be realized at energies accessible to laboratory
experiments. We study properties of the energy dependence of the potential for
different C-asymmetries of background. Interplay of the background potential
and the vacuum term leads to (i) bump in the oscillation probability in the
resonance region, (ii) dip related to the MSW resonance in the background,
(iii) substantial deviation of the effective $\Delta m^2$ above the resonance
from the low energy value, etc. We considered generation of mixing in the
background. Interactions with background shifts the energy of usual MSW
resonance and produces new MSW resonances. Searches of the background effects
allow us to put bounds on new interactions of neutrinos and properties of the
background. We show that explanation of the MiniBooNE excess, as the bump due
to resonance refraction, is excluded.",2106.13829v1
2021-07-21,Spin-wave growth via Shapiro resonances in a spinor Bose-Einstein condensate,"We theoretically study the resonant phenomenon in a spin-1 Bose-Einstein
condensate periodically driven by a quadratic Zeeman coupling. This phenomenon
is closely related to the Shapiro steps in superconducting Josephson junctions,
and the previous experimental work [Evrard $et al.,$ Phys. Rev. A 100, 023604
(2019)] for a spin-1 bosonic system observed the resonant dynamics and then
called it Shapiro resonance. In this work, using the spin-1 Gross-Pitaevskii
equation, we study the Shapiro resonance beyond the single-mode approximation
used in the previous work, which assumes that all components of the spinor
wavefunction have the same spatial configuration. Considering resonant dynamics
starting from a polar state, we analytically calculate the Floquet-Lyapunov
exponents featuring an onset of the resonance under a linear analysis and find
that spin waves with finite wavenumbers can be excited. This kind of
non-uniform excitation cannot be described by the single-mode approximation.
Furthermore, to study the long-time resonant dynamics beyond the linear
analysis, we numerically solve the one-dimensional spin-1 Gross-Pitaevskii
equation, finding that the nonresonant hydrodynamic variables also grow at
wavelengths of even multiples of the resonant one due to the nonlinear effect.",2107.09924v1
2021-07-21,Parametric longitudinal coupling between a high-impedance superconducting resonator and a semiconductor quantum dot singlet-triplet spin qubit,"Long-distance two-qubit coupling, mediated by a superconducting resonator, is
a leading paradigm for performing entangling operations in a quantum computer
based on spins in semiconducting materials. Here, we demonstrate a novel,
controllable spin-photon coupling based on a longitudinal interaction between a
spin qubit and a resonator. We show that coupling a singlet-triplet qubit to a
high-impedance superconducting resonator can produce the desired longitudinal
coupling when the qubit is driven near the resonator's frequency. We measure
the energy splitting of the qubit as a function of the drive amplitude and
frequency of a microwave signal applied near the resonator antinode, revealing
pronounced effects close to the resonator frequency due to longitudinal
coupling. By tuning the amplitude of the drive, we reach a regime with
longitudinal coupling exceeding $1$ MHz. This demonstrates a new mechanism for
qubit-resonator coupling, and represents a stepping stone towards producing
high-fidelity two-qubit gates mediated by a superconducting resonator.",2107.10269v1
2021-09-03,Probing double hadron resonances by the complex scaling method,"Many newly discovered excited states are interpreted as bound states of
hadrons. Can these hadrons also form resonant states? In this paper, we extend
the complex scaling method (CSM) to calculate the bound state and resonant
state consistently for the $\Lambda_c D(\bar D)$ and $\Lambda_c \Lambda_c (\bar
\Lambda_c)$ systems. For these systems, the $\pi, \eta, \rho$ meson exchange
contributions are suppressed, the contributions of intermediate- and
short-range forces from $\sigma/\omega$ exchange are dominant. Our results
indicate that $\Lambda_c D$ system can not form bound state and resonant state.
There exist resonant states in a wide range of parameters for $\Lambda_c \bar
D$ and $\Lambda_c \Lambda_c (\bar \Lambda_c)$ systems. For these systems, the
larger bound state energy, the easier to form resonant states. Among all the
resonant states, the energies and widths of the P wave resonant states are
smaller and more stable, which is possible to be observed in the experiments.
The energies of D and F wave resonant states can reach dozens of MeV and the
widths can reach hundreds of MeV.",2109.01259v1
2021-12-09,Collective resonance of $D$ states in rubidium atoms probed by optical two-dimensional coherent spectroscopy,"Collective resonance of interacting particles has important implications in
many-body quantum systems and their applications. Strong interactions can lead
to a blockade that prohibits the excitation of a collective resonance of two or
more nearby atoms. However, a collective resonance can be excited with the
presence of weak interaction and has been observed for atoms in the first
excited state ($P$ states). Here, we report the observation of collective
resonance of rubidium atoms in a higher excited state ($D$ states) in addition
to the first excited state. The collective resonance is excited by a
double-quantum four-pulse excitation sequence. The resulting double-quantum
two-dimensional (2D) spectrum displays well-isolated peaks that can be
attributed to collective resonances of atoms in $P$ and $D$ states. The
experimental one-quantum and double-quantum 2D spectra can be reproduced by a
simulation based on the perturbative solutions to the optical Bloch equations,
confirming collective resonances as the origin of the measured spectra. The
experimental technique provides a new approach for preparing and probing
collective resonances of atoms in highly excited states.",2112.04642v1
2021-12-31,Microscopy of an ultranarrow Feshbach resonance using a laser-based atom collider: A quantum defect theory analysis,"We employ a quantum defect theory framework to provide a detailed analysis of
the interplay between a magnetic Feshbach resonance and a shape resonance in
cold collisions of ultracold $\rm ^{87}Rb$ atoms as captured in recent
experiments using a laser-based collider [Phys. Rev. Research 3, 033209
(2021)]. By exerting control over a parameter space spanned by both collision
energy and magnetic field, the width of a Feshbach resonance can be tuned over
several orders of magnitude. We apply a quantum defect theory specialized for
ultracold atomic collisions to fully describe of the experimental observations.
While the width of a Feshbach resonance generally increases with collision
energy, its coincidence with a shape resonance leads to a significant
additional boost. By conducting experiments at a collision energy matching the
shape resonance and using the shape resonance as a magnifying lens we
demonstrate a feature broadening to a magnetic width of 8 G compared to a
predicted Feshbach resonance width $\ll 0.1$~mG.",2112.15416v3
2022-03-16,Elastodynamical resonances and cloaking of negative material structures beyond quasistatic approximation,"Given the flexibility of choosing negative elastic parameters, we construct
material structures that can induce two resonance phenomena, referred to as the
elastodynamical resonances. They mimic the emerging plasmon/polariton resonance
and anomalous localized resonance in optics for subwavelength particles.
However, we study the peculiar resonance phenomena for linear elasticity beyond
the subwavelength regime. It is shown that the resonance behaviours possess
distinct characters, with some similar to the subwavelength resonances, but
some sharply different due to the frequency effect. It is particularly noted
that we construct a core-shell material structure that can induce anomalous
localized resonance as well as cloaking phenomena beyond the quasi-static
limit. The study is boiled down to analyzing the so-called elastic
Neumann-Poinc\'are (N-P) operator in the frequency regime. We provide an
in-depth analysis of the spectral properties of the N-P operator beyond the
quasi-static approximation,and these results are of independent interest to the
spectral theory of layer potential operators.",2203.08432v1
2022-04-18,Influence of the presence of multiple resonances on material parameter determination using broadband ferromagnetic resonance spectroscopy,"The influence of the presence of multiple resonances in ferromagnetic
resonance spectra on extracted material parameters is investigated using
numerical simulations. Our results show that the systematic error of assuming
an incorrect number of resonances for a material can lead to the extraction of
material parameters that significantly deviate from any of the true material
parameters. When noise is present in experimental ferromagnetic resonance
spectra increasing the frequency range of the broadband characterization can
significantly reduce the error-margins when the data is analyzed assuming the
correct number of resonances present in the material. For the cases
investigated in this study it was found that analyzing the data using a single
resonance results in extracted gyromagnetic ratios and effective magnetization
parameters that are consistent with the weighted average of the true material
parameters. We further provide a cautionary example regarding the extraction of
the inhomogeneous linewidth broadening and damping parameters of materials that
contain an unknown number of resonances.",2204.08500v1
2022-05-02,Off-resonance artifact correction for magnetic resonance imaging: a review,"In magnetic resonance imaging (MRI), inhomogeneity in the main magnetic field
used for imaging, referred to as off-resonance, can lead to image artifacts
ranging from mild to severe depending on the application. Off-resonance
artifacts, such as signal loss, geometric distortions, and blurring, can
compromise the clinical and scientific utility of MR images. In this review, we
describe sources of off-resonance in MRI, how off-resonance affects images, and
strategies to prevent and correct for off-resonance. Given recent advances and
the great potential of low field and/or portable MRI, we also highlight the
advantages and challenges of imaging at low field with respect to
off-resonance.",2205.01028v2
2022-07-06,Spectral correlation between surface-enhanced resonant Raman and far field scattering destructed by dipole quadrupole coupled plasmon resonance,"The spectral relationships between surface enhanced resonant Raman scattering
(SERRS) and plasmon resonance observed in far field scattering cross are
investigated using single silver nanoparticle dimers with focusing on the
lowest energy (superradiant) plasmon resonance. We find that these
relationships can be classified into two types. The first is SERRS spectral
envelopes with spectral shapes similar to those of plasmon resonance spectra.
The second is SERRS envelopes exhibiting higher energy shifts from the plasmon
resonance spectra. These results are examined as an effect of degree of
morphological asymmetry in dimers based on an electromagnetic (EM) mechanism.
The analysis of the first and second types reveals that dipole-dipole and
dipole-quadrupole coupled plasmon resonance (subradiant Fano resonance)
respectively determine the EM enhancement. This mechanism is commonly important
for the development of plasmonic nanostructures for various surface enhanced
spectroscopies.",2207.02513v2
2022-09-25,ATLAS results on exotic hadronic resonances,"Recent results from the proton-proton collision data taken by the ATLAS
experiment on exotic resonances are presented. A search for $J/\psi p$
resonances in $\Lambda_{b}\rightarrow J/\psi p K$ decays with large $p K$
invariant masses is reported. A search for exotic resonances in the four-muon
final state is shown.",2209.12173v3
2022-12-17,Characteristics of partially filled Helmholtz resonators,"In this work we have developed a technique for the measurement of the
resonance curve of Helmholtz resonators as a function of filling with beads and
sands of different sizes, and water as the reference. Our measurements allowed
us to observe very different behaviors of resonance frequencies and resonance
half-widths as a function of the size of the sand grains and the beads. By
comparing results for beads and water we were able to prove that the sound
penetrates the interstitial space between the beads. This was confirmed by
measurements of the resonance properties in resonators filled with spherical
beads whose experimentally determined filling factor is close to the random
filling factor of about 0.54. The similar behavior of the frequency and
half-width of resonance of sand-filled resonators of three different sizes
allowed us to suggest that sound penetrates the sand in the same way as it does
the beads.",2212.08858v1
2022-12-22,Resonant contributions to polarized proton structure functions,"Nucleon resonance contributions to the polarized proton $g_1$ and $g_2$
structure functions are computed from resonance electroexcitation amplitudes
extracted from CLAS exclusive meson electroproduction data. Including
resonances in the mass range up to 1.75 GeV, and taking into account the
interference between excited states, we compare the resonant contributions with
the polarized proton structure function and polarization asymmetry data from
Jefferson Lab 6 GeV measurements. All resonance-like structure observed in the
polarized structure functions and asymmetries can be attributed to the resonant
contributions, confirming their essential role in the behavior of $g_1$ and
$g_2$ in the resonant region over the entire range $Q^2 < 7.5$ GeV$^2$ covered
by the measurements. Comparing the resonance contributions with the $g_1$ and
$g_2$ structure functions computed from parton distribution functions
extrapolated from the deep-inelastic region, we also quantify the degree to
which quark-hadron duality holds for $g_1$ and $g_2$ and their moments.",2212.11952v2
2023-06-13,Outerplane bipartite graphs with isomorphic resonance graphs,"We present novel results related to isomorphic resonance graphs of
2-connected outerplane bipartite graphs. As the main result, we provide a
structure characterization for 2-connected outerplane bipartite graphs with
isomorphic resonance graphs. Moreover, two additional characterizations are
expressed in terms of resonance digraphs and via local structures of inner
duals of 2-connected outerplane bipartite graphs, respectively.",2306.07611v1
2023-07-10,On the experimental description of neutron resonances,"We present a collection of simple derivations for the neutron-induced
resonance cross-sections. These formulae are commonly used to experimentally
describe the fundamental properties of resonances for neutron-rich nuclei far
from stability and to describe unbound nuclei. The main goal of this article is
to illustrate their dependencies with basic observables in order to discuss the
pertinence of experimental approaches in the derivation of their properties,
especially for ""N-body"" resonances.",2307.04560v1
2023-07-16,Controlling periodic Fano resonances of quantum acoustic waves with a giant atom coupled to microwave waveguide,"Nanoscale Fano resonances, with applications from telecommunications to
ultra-sensitive biosensing, have prompted extensive research. We demonstrate
that a superconducting qubit, jointly coupled to microwave waveguides and an
inter-digital transducer composite device, can exhibit acoustic Fano
resonances. Our analytical framework, leveraging the Taylor series
approximation, elucidates the origins of these quantum acoustic resonances with
periodic Fano-like interference. By analyzing the analytical Fano parameter, we
demonstrate that the Fano resonances and their corresponding Fano widths near
the resonance frequency of a giant atom can be precisely controlled and
manipulated by adjusting the time delay. Moreover, not just the near-resonant
Fano profiles, but the entire periodic Fano resonance features can be precisely
modulated from Lorentz, Fano to quasi-Lorentz shapes by tuning the coupling
strength of the microwave waveguide. Our analytical framework offers insights
into the control and manipulation of periodic Fano resonances in quantum
acoustic waves, thereby presenting significant potential for applications such
as quantum information processing, sensing, and communication.",2307.07949v1
2023-07-28,Bilayer Metasurface: Induced Transparency and Fabry Perot Resonance,"A Fabry-Perot resonator utilizes two solid, non-resonating, reflecting
mirrors to form resonant patterns when the separation between the mirrors
satisfies the resonance conditions. The resonant mode concentrates at the
middle of the cavity. In this study, we constructed a Fabry-Perot cavity with
nanostructured resonant metasurfaces as meta-mirrors. The individual
metasurfaces exhibit resonant transmission dips with a minimum transmission and
a quality factor of t0 and Qs, respectively. The coherent interference between
the two metasurfaces changes the behavior of the entire resonant system,
generating an induced transparency in the original spectrum. The sharpness of
the induced transparency peak is linearly related to the group delay of the
single metasurface. Assuming a Lorentzian lineshape, we show that for small t0,
the quality factor of the induced transparency peak is Qs/t0^3. The field
confines to the meta-mirrors region rather than at the middle of the
Fabry-Perot cavity. We provide examples of practical metasurfaces made from
dielectric scatters composed of silicon thin nanodisks and demonstrate high
quality factors and phase dispersion that are unattainable by any nano or
microscale flat optics systems.",2307.15414v1
2023-10-19,Mathematical theory on dipolar resonances of hard inclusions within a soft elastic material,"The current study is motivated by the paper [Z. Liu, et al., {\it Science},
289(5485), 2000], which investigates the incorporation of hard inclusions
within a soft elastic matrix (HISE). The objective is to attain a negative mass
density, which is caused by sub-wavelength dipolar resonances. This paper
offers a comprehensive and mathematically rigorous understanding of the dipolar
resonances within the HISE structure. Firstly, the original formula for the
resonant frequencies of arbitrarily shaped hard inclusions is derived
explicitly for the first time. Additionally, we demonstrate that the resonances
arise due to the high contrast in Lam\'e parameters between various materials,
while the sub-wavelength characteristics of the resonances are attributed to
the significant disparities in material densities. Furthermore, the dipolar
characterization of the resonances is rigorously justified. To validate our
findings, we investigate resonant phenomena within a spherical geometry,
offering both an alternative method for calculating resonant frequencies and a
confirmation of the results presented in this paper.",2310.12861v2
2023-10-24,On the degeneracy of whispering gallery modes in a high-Q sapphire microwave resonator,"Cylindrical WGM resonators machined in high-quality sapphire monocrystal
cooled down to liquid helium temperature offer exceptionally-high Q-factors in
the microwave frequency domain. Such a resonator constitutes the core of an
ultra-stable oscillator featuring fractional frequency stability better than
1e-15 at short integration times. As in any cylindrical resonant structure, the
WGM resonator presents a two fold degeneracy. When a defect breaks the
cylindrical symmetry of the resonator, the WGMs split and appear as doublets.
In the high-quality sapphire resonator, the frequency separation of these twin
modes varies from one mode order to another with a maximum value of a few tens
of kHz. While the mode splitting for a given mode was considered until now
unpredictable and intrinsic to each resonator since resulting a priori from
randomly distributed defects. we show here, at the contrary, that the observed
mode splitting found on all the sapphire resonators whatever their origin
mainly comes from a perfectly determined defect resulting from the
manufacturing processes.",2310.15573v1
2024-03-06,Resonant perturbation of a family of young asteroids associated with (5026) Martes,"The orbital dynamics of a very young asteroid pair (5026) Martes and 2005
WW113 is studied. We detect strong resonant perturbations of the larger member
of the pair (5026) Martes by the 3:11 mean motion resonance with the Earth. The
second asteroid of the pair (2005 WW113) has orbited far from the resonance and
is not perturbed. We provide a new estimation of the resonance structure and
found that, under the planetary perturbations, a single resonance splits into a
multiplet. The nominal position of the resonance is 2.37783 AU. However, the
center of the corresponding chaotic zone is detected at 2.37754 AU. As a
result, we noted a small but not negligible difference between the calculated
and observed position of resonance. The multiplet structure of the 3:11 Earth
resonance cannot explain this offset (the position of the main term of the
multiplet is 2.377698 AU).",2403.03559v1
2024-03-22,Closed-channel parameters of Feshbach resonances,"In the work of Phys. Rev. A 100, 042710 (2019), it was argued that the
general description of two-body Feshbach resonances requires ""closed-channel
parameters"" related to the bare bound state causing the resonance. The present
work shows that once the resonance theory is renormalised (i.e. its parameters
are expressed in terms of physical observables) the dependence of two-body
observables on the closed-channel parameters disappears when the inter-channel
coupling is localised in a region where the wave functions are energy
independent. In such a regime, the resulting quantum defect theory is
surprisingly independent of the bare bound state energy. This result highlights
a qualitative difference between resonances in this regime, such as magnetic
resonances in ultracold atoms, and other kinds of resonances, such as hadron
resonances. Although the closed-channel parameters of magnetic resonances do
not affect two-body observables, it is suggested that they could be evidenced
experimentally from short-distance probing and three-body observables.",2403.14962v1
2024-04-05,Resonant Raman signatures of exciton polarons in a transition metal oxide: BiVO$_4$,"In this work we investigate the delocalized excitons and excitons trapped by
a polaron formation in \BVO{} by means of resonant Raman spectroscopy. We
record Raman spectra with 16 laser lines between 1.9 and \SI{2.6}{\eV} and
analyze intensity variations of the Raman peaks for different vibrational
modes. The resonant Raman cross sections of the \Ag{} modes contain two types
of resonances. The first high-energy resonance near \SI{2.45}{\eV} belongs to a
transition between delocalized states; it is close to absorption edge measured
at \SI{2.3}{\eV} and exhibits a characteristic \SI{50}{\meV} anisotropy between
polarization parallel and perpendicular to the $c$ axis. The high energy Raman
resonance occurs inside the gap at \SI{1.94}{\eV} for all crystallographic
directions.
  The in-gap resonance can involve a localized transition. We attribute it to
an exciton-polaron, formed by a small localized electron polaron of Holstein
type and delocalized holes. It manifests in the vibrations of vanadium and
oxygen atoms where polaron localization occurs and the resonance energy matches
theoretical predictions. The vibrational modes couple to the polaron with
different efficiency determined from resonant Raman profiles.",2404.04112v1
2019-07-15,Resonance line in rotating accretion disc,"We study the resonance line emission from the rotating plane optically thick
accretion disc, consisting of free electrons and resonant atoms. We use the
standard assumption that the source of continuum radiation is located near
central plane of the accretion disc, where the temperature is the highest. This
corresponds to the Milne problem consideration for continuum. We shortly
discuss the impossibility of the Milne problem for the resonance radiation. We
assume that the resonant atoms are located in a thin layer of an accretion disc
near the surface. In this case the resonance line emission arises due to
scattering of a continuum on the resonant atoms. In thin layer we can neglect
the multiple scattering of the resonance radiation on the resonant atoms. We
consider the axially symmetric problems, where the Stokes parameter U =0. We
take into account the Doppler effect for the frequencies of the resonance line.
The three types of the resonant atom sources are considered (see Figs.1-3). The
first source is the axially symmetric continuous distribution of the resonant
atoms along the circular orbit. The second spot-like source rotates in the
orbit. The third type presents two spot-like sources located in the orbit
contrary one to another. In the first and third cases the shape of the emitting
resonance line is symmetric, i.e. the right and left wings have the similar
shapes. In the second case the resonance line has asymmetric shape. The shape
of the emerging line depends significantly on the ratio of the rotation
velocity value to the velocity, characterizing the Doppler width. It also
depends on the ratio of the electron number density to the number density of
resonant atoms. The results of the calculations characterize the different
observational effects of H$\alpha$ radiation in the accretion discs and can be
used for estimations of the parameters mentioned above.",1907.06416v1
2018-08-24,Capture into first-order resonances and long-term stability of pairs of equal-mass planets,"Massive planets form within the lifetime of protoplanetary disks and undergo
orbital migration due to planet-disk interactions. When the first planet
reaches the inner edge of the disk its migration stops and the second planet is
locked in resonance. We detail the resonant trapping comparing semi-analytical
formulae and numerical simulations in the case of two equal-mass coplanar
planets trapped in first order resonances. We describe the family of resonant
stable equilibrium points (zero-amplitude libration orbits) using expanded and
non-expanded Hamiltonians. We show that during convergent migration the planets
evolve along these families of equilibria. Eccentricity damping from the disk
leads to a final equilibrium configuration that we predict analytically. The
fact that observed multi-exoplanetary systems are rarely seen in resonances
suggests that the resonant configurations achieved by migration can become
unstable after the removal of the disk. We probe the stability of the
resonances as a function of planetary mass. To do this, we fictitiously
increase the masses of the planets, adiabatically maintaining the low-amplitude
libration regime until instability. We discuss two hypotheses for instability:
low-order secondary resonance of the libration frequency with a fast synodic
frequency, and minimal approach distance between planets. We show that
secondary resonances do not seem to impact resonant systems at low-amplitude of
libration. Resonant systems are more stable than non-resonant ones for a given
minimal distance at close encounters, but we show that the latter still play
the decisive role in the destabilisation of resonant pairs. We show that, as
the planetary mass increases and the minimal distance between planets gets
smaller in terms of mutual Hill radius, the region of stability around the
resonance center shrinks, until the equilibrium point itself becomes unstable.",1808.08059v1
1998-06-16,Ray and wave chaos in asymmetric resonant optical cavities,"Optical resonators are essential components of lasers and other
wavelength-sensitive optical devices. A resonator is characterized by a set of
modes, each with a resonant frequency omega and resonance width Delta
omega=1/tau, where tau is the lifetime of a photon in the mode. In a
cylindrical or spherical dielectric resonator, extremely long-lived resonances
are due to `whispering gallery' modes in which light circulates around the
perimeter trapped by total internal reflection. These resonators emit light
isotropically. Recently, a new category of asymmetric resonant cavities (ARCs)
has been proposed in which substantial shape deformation leads to partially
chaotic ray dynamics. This has been predicted to give rise to a universal,
frequency-independent broadening of the whispering-gallery resonances, and
highly anisotropic emission. Here we present solutions of the wave equation for
ARCs which confirm many aspects of the earlier ray-optics model, but also
reveal interesting frequency-dependent effects characteristic of quantum chaos.
For small deformations the lifetime is controlled by evanescent leakage, the
optical analogue of quantum tunneling. We find that the lifetime is much
shortened by a process known as `chaos-assisted tunneling'. In contrast, for
large deformations (~10%) some resonances are found to have longer lifetimes
than predicted by the ray chaos model due to `dynamical localization'.",9806017v1
2004-05-20,Strength of Higher-Order Spin-Orbit Resonances,"When polarized particles are accelerated in a synchrotron, the spin
precession can be periodically driven by Fourier components of the
electromagnetic fields through which the particles travel. This leads to
resonant perturbations when the spin-precession frequency is close to a linear
combination of the orbital frequencies. When such resonance conditions are
crossed, partial depolarization or spin flip can occur. The amount of
polarization that survives after resonance crossing is a function of the
resonance strength and the crossing speed. This function is commonly called the
Froissart-Stora formula. It is very useful for predicting the amount of
polarization after an acceleration cycle of a synchrotron or for computing the
required speed of the acceleration cycle to maintain a required amount of
polarization. However, the resonance strength could in general only be computed
for first-order resonances and for synchrotron sidebands. When Siberian Snakes
adjust the spin tune to be 1/2, as is required for high energy accelerators,
first-order resonances do not appear and higher-order resonances become
dominant. Here we will introduce the strength of a higher-order spin-orbit
resonance, and also present an efficient method of computing it. Several
tracking examples will show that the so computed resonance strength can indeed
be used in the Froissart-Stora formula. HERA-p is used for these examples which
demonstrate that our results are very relevant for existing accelerators.",0405108v1
2007-12-19,Destruction and Resurrection of Atomic Giant resonances in Endohedral Atoms A@C60,"It is demonstrated that in photoabsorption by endohedral atoms some atomic
Giant resonances are almost completely destroyed while the others are totally
preserved due to different action on it of the fullerenes shell. As the first
example we discuss the 4d10 Giant resonance in Xe@C60 whereas as the second
serves the Giant autoionization resonance in Eu@C60. The qualitative difference
comes from the fact that photoelectrons from the 4d Giant resonance has small
energies (tens of eV) and are strongly reflected by the C60 fullerenes shell.
As to the Eu@C60, Giant autoionization leads to fast photoelectrons (about
hundred eV) that go out almost untouched by the C60 shell. As a result of the
outgoing electrons energy difference the atomic Giant resonances will be
largely destroyed in A@C60 while the Giant autoionization resonance will be
almost completely preserved. Thus, on the way from Xe@C60 Giant resonance to
Eu@C60 Giant autoionization resonance the oscillation structure should
disappear. Similar will be the decrease of oscillations on the way from pure
Giant to pure Giant autoionization resonances for the angular anisotropy
parameters. At Giant resonance frequencies the role of polarization of the
fullerenes shell by the incoming photon beam is inessential. Quite different is
the situation for the outer electrons in Eu@C60, the photoionization of which
will be also considered.",0712.3253v1
2009-11-01,Transmission resonances in above-barrier reflection of ultra-cold atoms by the Rosen-Morse potential,"Quantum above-barrier reflection of ultra-cold atoms by the Rosen-Morse
potential is analytically considered within the mean field Gross-Pitaevskii
approximation. Reformulating the problem of reflectionless transmission as a
quasi-linear eigenvalue problem for the potential depth, an approximation for
the specific height of the potential that supports reflectionless transmission
of the incoming matter wave is derived via modification of the
Rayleigh-Schroedinger time-independent perturbation theory. The approximation
provides highly accurate description of the resonance position for all the
resonance orders if the nonlinearity parameter is small compared with the
incoming particles chemical potential. Notably, the result for the first
transmission resonance turns out to be exact, i.e., the derived formula for the
resonant potential height gives the exact value of the first nonlinear
resonances position for all the allowed variation range of the involved
parameters, the nonlinearity parameter and chemical potential. This has been
shown by constructing the exact solution of the problem for the first
resonance. Furthermore, the presented approximation reveals that, in contrast
to the linear case, in the nonlinear case reflectionless transmission may occur
not only for potential wells but also for potential barriers with positive
potential height. It also shows that the nonlinear shift of the resonance
position from the position of the corresponding linear resonance is
approximately described as a linear function of the resonance order. Finally, a
compact (yet, highly accurate) analytic formula for the n-th order resonance
position is constructed via combination of analytical and numerical methods.",0911.0158v1
2011-04-20,Asteroid families in the first order resonances with Jupiter,"Asteroids residing in the first-order mean motion resonances with Jupiter
hold important information about the processes that set the final architecture
of giant planets. Here we revise current populations of objects in the J2/1
(Hecuba-gap group), J3/2 (Hilda group) and J4/3 (Thule group) resonances. The
number of multi-opposition asteroids found is 274 for J2/1, 1197 for J3/2 and 3
for J4/3. Using both hierarchical clustering technique and colour
identification we characterise a collisionally-born asteroid family around the
object (1911) Schubart in the J3/2 resonance. There is also a looser cluster
around the largest asteroid (153) Hilda. Using N-body numerical simulations we
prove that the Yarkovsky effect (infrared thermal emission from the surface of
asteroids) causes a systematic drift in eccentricity for resonant asteroids,
while their semimajor axis is almost fixed due to the strong coupling with
Jupiter. This is a different mechanism from main belt families, where the
Yarkovsky drift affects basically the semimajor axis. We use the eccentricity
evolution to determine the following ages: (1.7+-0.7) Gyr for the Schubart
family and >~4 Gyr for the Hilda family. We also find that collisionally-born
clusters in the J2/1 resonance would efficiently dynamically disperse. The
steep size distribution of the stable population inside this resonance could
thus make sense if most of these bodies are fragments from an event older than
~1 Gyr. Finally, we test stability of resonant populations during Jupiter's and
Saturn's crossing of their mutual mean motion resonances. In particular we find
primordial objects in the J3/2 resonance were efficiently removed from their
orbits when Jupiter and Saturn crossed their 1:2 mean motion resonance.",1104.4004v1
2011-05-25,Origin and Sustainability of The Population of Asteroids Captured in the Exterior Resonance 1:2 with Mars,"At present, approximately 1500 asteroids are known to evolve inside or
sticked to the exterior 1:2 resonance with Mars at a = 2.418 AU, being (142)
Polana the largest member of this group. The effect of the forced secular modes
superposed to the resonance gives rise to a complex dynamical evolution.
Chaotic diffusion, collisions, close encounters with massive asteroids and
mainly orbital migration due to the Yarkovsky effect generate continuous
captures to and losses from the resonance, with a fraction of asteroids
remaining captured over long time scales and generating a concentration in the
semimajor axis distribution that exceeds by 20% the population of background
asteroids. The Yarkovsky effect induces different dynamics according to the
asteroid size, producing an excess of small asteroids inside the resonance. The
evolution in the resonance generates a signature on the orbits, mainly in
eccentricity, that depends on the time the asteroid remains captured inside the
resonance and on the magnitude of the Yarkovsky effect. The greater the
asteroids, the larger the time they remain captured in the resonance, allowing
greater diffusion in eccentricity and inclination. The resonance generates a
discontinuity and mixing in the space of proper elements producing
misidentification of dynamical family members, mainly for Vesta and Nysa-Polana
families. The half-life of resonant asteroids large enough for not being
affected by the Yarkovsky effect is about 1 Gyr. From the point of view of
taxonomic classes, the resonant population does not differ from the background
population and the excess of small asteroids is confirmed.",1105.5108v1
2012-06-01,Theoretical formalism for collective electromagnetic response of discrete metamaterial systems,"We develop a general formalism to describe the propagation of a near-resonant
electromagnetic field in a medium composed of magnetodielectric resonators. As
the size and the spatial separation of nanofabricated resonators in a
metamaterial array is frequently less than the wavelength, we describe them as
discrete scatterers, supporting a single mode of current oscillation
represented by a single dynamic variable. We derive a Lagrangian and
Hamiltonian formalism for the coupled electromagnetic fields and oscillating
currents in the length gauge, obtained by the Power-Zienau-Woolley
transformation. The response of each resonator to electromagnetic field is then
described by polarization and magnetization densities that, to the lowest order
in a multipole expansion, generate electric and magnetic dipole excitations. We
derive a closed set of equations for the coherently scattered field and normal
mode amplitudes of current oscillations of each resonator both within the
rotating wave approximation, in which case the radiative decay rate is much
smaller than the resonance frequency, and without such an assumption. The set
of equations includes the radiative couplings between a discrete set of
resonators mediated by the electromagnetic field, fully incorporating recurrent
scattering processes to all orders. By considering an example of a
two-dimensional split ring resonator metamaterial array, we show that the
system responds cooperatively to near-resonant field, exhibiting collective
eigenmodes, resonance frequencies, and radiative linewidths that result from
strong radiative interactions between closely-spaced resonators.",1206.0204v2
2013-12-17,Dynamical resonance locking in tidally interacting binary systems,"We examine the dynamics of resonance locking in detached, tidally interacting
binary systems. In a resonance lock, a given stellar or planetary mode is
trapped in a highly resonant state for an extended period of time, during which
the spin and orbital frequencies vary in concert to maintain the resonance.
This phenomenon is qualitatively similar to resonance capture in planetary
dynamics. We show that resonance locks can accelerate the course of tidal
evolution in eccentric systems and also efficiently couple spin and orbital
evolution in circular binaries. Previous analyses of resonance locking have not
treated the mode amplitude as a fully dynamical variable, but rather assumed
the adiabatic (i.e. Lorentzian) approximation valid only in the limit of
relatively strong mode damping. We relax this approximation, analytically
derive conditions under which the fixed point associated with resonance locking
is stable, and further check these analytic results using numerical
integrations of the coupled mode, spin, and orbital evolution equations. These
show that resonance locking can sometimes take the form of complex limit cycles
or even chaotic trajectories. We provide simple analytic formulae that define
the binary and mode parameter regimes in which resonance locks of some kind
occur (stable, limit cycle, or chaotic). We briefly discuss the astrophysical
implications of our results for white dwarf and neutron star binaries as well
as eccentric stellar binaries.",1312.4966v2
2014-02-17,An Analytic Model for Buoyancy Resonances in Protoplanetary Disks,"Zhu, Stone, and Rafikov (2012) found in 3D shearing box simulations a new
form of planet-disk interaction that they attributed to a vertical buoyancy
resonance in the disk. We describe an analytic linear model for this
interaction. We adopt a simplified model involving azimuthal forcing that
produces the resonance and permits an analytic description of its structure. We
derive an analytic expression for the buoyancy torque and show that the
vertical torque distribution agrees well with results of Athena simulations and
a Fourier method for linear numerical calculations carried out with the same
forcing. The buoyancy resonance differs from the classic Lindblad and
corotation resonances in that the resonance lies along tilted planes. Its width
depends on damping effects and is independent of the gas sound speed. The
resonance does not excite propagating waves. At a given large azimuthal
wavenumber k_y > 1/h (for disk thickness h), the buoyancy resonance exerts a
torque over a region that lies radially closer to the corotation radius than
the Lindblad resonance. Because the torque is localized to the region of
excitation, it is potentially subject to the effects of nonlinear saturation.
In addition, the torque can be reduced by the effects of radiative heat
transfer between the resonant region and its surroundings. For each azimuthal
wavenumber, the resonance establishes a large scale density wave pattern in a
plane within the disk.",1402.4162v1
2014-04-29,Fano resonance control in a photonic crystal structure and its application to ultrafast switching,"Fano resonances appear in quantum mechanical as well as classical systems as
a result of the interference between two paths: one involving a discrete
resonance and the other a continuum. Compared to a conventional resonance,
characterized by a Lorentzian spectral response, the characteristic asymmetric
and sharp spectral response of a Fano resonance is suggested to enable photonic
switches and sensors with superior characteristics. While experimental
demonstrations of the appearance of Fano resonances have been made in both
plasmonic and photonic-crystal structures, the control of these resonances is
experimentally challenging, often involving the coupling of near-resonant
cavities. Here, we experimentally demonstrate two simple structures that allow
surprisingly robust control of the Fano spectrum. One structure relies on
controlling the amplitude of one of the paths and the other uses symmetry
breaking. Short-pulse dynamic measurements show that besides drastically
increasing the switching contrast, the transmission dynamics itself is strongly
affected by the nature of the resonance. The influence of slow-recovery tails
implied by a long carrier lifetime can thus be reduced using a Fano resonance
due to a hitherto unrecognized reshaping effect of the nonlinear Fano transfer
function. For the first time, we present a system application of a Fano
structure, demonstrating its advantages by the experimental realization of 10
Gbit/s all-optical modulation with bit-error-ratios on the order of 10$^{-7}$
for input powers less than 1 mW. These results represent a significant
improvement compared to the use of a conventional Lorentzian resonance.",1404.7532v1
2014-08-05,Resonant Chains and Three-body Resonances in the Closely-Packed Inner Uranian Satellite System,"Numerical integrations of the closely-packed inner Uranian satellite system
show that variations in semi-major axes can take place simultaneously between
three or four consecutive satellites. We find that the three-body Laplace angle
values are distributed unevenly and have histograms showing structure, if the
angle is associated with a resonant chain, with both pairs of bodies near
first-order two-body resonances. Estimated three-body resonance libration
frequencies can be only an order of magnitude lower than those of first-order
resonances. Their strength arises from a small divisor from the distance to the
first-order resonances and insensitivity to eccentricity, which make up for
their dependence on moon mass. Three-body resonances associated with
low-integer Laplace angles can also be comparatively strong due to the many
multiples of the angle contributed from Fourier components of the interaction
terms. We attribute small coupled variations in semi-major axis, seen
throughout the simulation, to ubiquitous and weak three-body resonant
couplings. We show that a system with two pairs of bodies in first-order
mean-motion resonance can be transformed to resemble the well-studied
periodically-forced pendulum with the frequency of a Laplace angle serving as a
perturbation frequency. We identify trios of bodies and overlapping pairs of
two-body resonances in each trio that have particularly short estimated
Lyapunov timescales.",1408.1141v1
2014-09-11,Universal non-resonant absorption in carbon nanotubes,"Photoluminescence excitation measurements in semi-conducting carbon nanotubes
show a systematic non-resonant contribution between the well known excitonic
resonances. Using a global analysis method, we were able to delineate the
contribution of each chiral species including its tiny non-resonant component.
By comparison with the recently reported excitonic absorption cross-section on
the $S_{22}$ resonance, we found a universal non-resonant absorbance which
turns out to be of the order of one half of that of an equivalent graphene
sheet. This value as well as the absorption line-shape in the non-resonant
window is in excellent agreement with microscopic calculations based on the
density matrix formalism. This non-resonant absorption of semi-conducting
nanotubes is essentially frequency independent over 0.5~eV wide windows and
reaches approximately the same value betweeen the $S_{11}$ and $S_{22}$
resonances or between the $S_{22}$ and $S_{33}$ resonances. In addition, the
non-resonant absorption cross- section turns out to be the same for all the
chiral species we measured in this study. From a practical point of view, this
study puts firm basis on the sample content analysis based on photoluminescence
studies by targeting specific excitation wavelengths that lead to almost
uniform excitation of all the chiral species of a sample within a given
diameter range.",1409.3441v1
2015-02-23,Theoretical characterization of the collective resonance states underlying the xenon giant dipole resonance,"We present a detailed theoretical characterization of the two fundamental
collective resonances underlying the xenon giant dipole resonance (GDR). This
is achieved consistently by two complementary methods implemented within the
framework of the configuration-interaction singles (CIS) theory. The first
method accesses the resonance states by diagonalizing the many-electron
Hamiltonian using the smooth exterior complex scaling technique. The second
method involves a new application of the Gabor analysis to wave-packet
dynamics. We identify one resonance at an excitation energy of 74 eV with a
lifetime of 27 as, and the second at 107 eV with a lifetime of 11 as. Our work
provides a deeper understanding of the nature of the resonances associated with
the GDR: a group of close-lying intrachannel resonances splits into two
far-separated resonances through interchannel couplings involving the 4d
electrons. The CIS approach allows a transparent interpretation of the two
resonances as new collective modes. Due to the strong entanglement between the
excited electron and the ionic core, the resonance wave functions are not
dominated by any single particle-hole state. This gives rise to plasma-like
collective oscillations of the 4d shell as a whole.",1502.06462v1
2015-03-01,Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter,"Study of interaction between high absorption matter and microwave radiated
energy is a subject of great importance. Especially, this concerns microwave
spectroscopic characterization of biological liquids. Use of effective testing
methods to obtain information about physical properties of different liquids on
the molecular level is one of the most important problems in biophysics.
However, the standard methods based on the microwave resonant techniques are
not sufficiently suitable for biological liquids because the resonance peak in
a resonator with high-loss liquids is so broad that the material parameters
cannot be measured correctly. Although molecular vibrations of biomolecules may
have microwave frequencies, it is not thought that such resonant coupling is
significant due to their low energy compared with thermal energy and the
strongly dampening aqueous environment. This paper presents an innovative
microwave sensing technique for different types of lossy materials, including
biological liquids. The technique is based on the combination of the microwave
perturbation method and the Fano-resonance effects observed recently in
microwave structures with embedded magnetic-dipolar quantum dots. When
frequency of the magnetic-dipolar-mode (MDM) resonance is not equal to the
cavity resonance frequency, one gets Fano transmission intensity. With tuning,
by a bias magnetic field, the MDM resonance frequency to the cavity resonance
frequency, one observes a Lorentz line shape. Use of an extremely narrow
Lorentzian peak allows exact probing the resonant frequency of a cavity loaded
by a high-lossy-material sample. For different kinds of samples, one has
different frequencies of Lorentzian peaks. This gives a picture for precise
spectroscopic characterization of high absorption matter in microwaves.",1503.00286v1
2016-12-22,Frequency control and coherent excitation transfer in a nanostring resonator network,"Coupling, synchronization, and non-linear dynamics of resonator modes are
omnipresent in nature and highly relevant for a multitude of applications
ranging from lasers to Josephson arrays and spin torque oscillators.
Nanomechanical resonators are ideal candidates to study these effects on a
fundamental level and to realize all-mechanical platforms for information
processing and storage. For larger resonator networks, however, this requires
the ability to tune the mode frequencies selectively and to operate the
resonators in the strong coupling regime. Here, we present a proof-of-principle
realization of a resonator network consisting of two high-quality nanostring
resonators, coupled mechanically by a shared support. First, we demonstrate
that we can control the fundamental mode frequencies of both nanostrings
independently by a strong drive tone resonant with one of the higher harmonics
of the network, rendering local control gates redundant. The tuning mechanism
relies on an effective increase of the pre-stress in a highly excited
nanostring, known as geometric nonlinearity. Using this selective frequency
control of the individual nanomechanical resonators, we investigate the
coherent dynamics of the resonator network, which is a classical model system
showing several of the characteristic features of strongly coupled quantum
systems. In particular, we demonstrate mode splitting, classical Rabi
oscillations, as well as adiabatic and diabatic transitions between the coupled
states representing the classical analog of Landau-Zener tunneling. Therefore,
this coupling and tuning concept opens the path to a selective phonon transfer
between two spatially separated mechanical resonators.",1612.07511v1
2018-09-24,Secular Resonance Between Iapetus and the Giant Planets,"Using numerical integrations, we find that the orbital eccentricity of
Saturn's moon Iapetus undergoes prominent multi-Myr oscillations. We identify
the responsible resonant argument to be
$\varpi-\varpi_{g5}+\Omega-\Omega_{eq}$, with the terms being the longitudes of
pericenter of Iapetus and planetary secular mode $g_5$, Iapetus's longitude of
the node and Saturn's equinox. We find that this argument currently (on a
$10^7$~yr timescale) appears to librate with a very large amplitude. On longer
timescales, the behavior of this resonant angle is strongly dependent on the
resonant interaction between Saturn's spin axis and the planetary mode $f_8$,
with long-term secular resonance being possible if Saturn's equinox is
librating relative to the node of the $f_8$ eigenmode. We present analytical
estimates of the dependence of the resonant argument on the orbital elements of
Iapetus. We find that this Iapetus-$g_5$ secular resonance could have been
established only after the passage of Iapetus through the 5:1 mean-motion
resonance with Titan, possibly in the last Gyr. Using numerical simulations, we
show that the capture into the secular resonance appears to be a
low-probability event. While the Iapetus-$g_5$ secular resonance can
potentially help us put new constraints on the past dynamics of the Saturnian
system, uncertainties in both the spin axis dynamics of Saturn and the tidal
evolution rate of Titan make it impossible to make any firm conclusions about
the resonance's longevity and origin.",1809.09072v1
2018-09-26,First-order mean motion resonances in two-planet systems: general analysis and observed systems,"This paper focuses on two-planet systems in a first-order $(q+1):q$ mean
motion resonance and undergoing type-I migration in a disc. We present a
detailed analysis of the resonance valid for any value of $q$. Expressions for
the equilibrium eccentricities, mean motions and departure from exact resonance
are derived in the case of smooth convergent migration. We show that this
departure, not assumed to be small, is such that period ratio normally exceeds,
but can also be less than, $ (q+1)/q.$ Departure from exact resonance as a
function of time for systems starting in resonance and undergoing divergent
migration is also calculated. We discuss observed systems in which two low mass
planets are close to a first-order resonance. We argue that the data are
consistent with only a small fraction of the systems having been captured in
resonance. Furthermore, when capture does happen, it is not in general during
smooth convergent migration through the disc but after the planets reach the
disc inner parts. We show that although resonances may be disrupted when the
inner planet enters a central cavity, this alone cannot explain the spread of
observed separations. Disruption is found to result in either the system moving
interior to the resonance by a few percent, or attaining another resonance. We
postulate two populations of low mass planets: a small one for which extensive
smooth migration has occurred, and a larger one that formed approximately
in-situ with very limited migration.",1809.10042v1
2020-04-05,Resonant high-energy bremsstrahlung of ultrarelativistic electrons in the field of a nucleus and a pulsed light wave,"The actual theoretical research investigates the resonant high-energy
spontaneous bremsstrahlung of ultrarelativistic electrons with considerable
energies in the field of a nucleus and a quasimonochromatic laser wave. Under
the resonant conditions within the laser field the intermediate virtual
electron transforms into the real particle. As a result, the accomplished
analysis defines that the polar emission angle characterizes the frequency of a
spontaneous photon. The study derives the expressions for the resonant
differential cross-sections of the represented processes that realize
simultaneous registration of the frequency and radiation angle in correlation
to the momentum of the initial electron (for the channel A) and of the final
electron (for the channel B) of the spontaneous photon with absorption of $r$
wave photons ($r = 1, 2, 3,... $ - the number of a resonance). Additionally,
the distribution of the resonant differential cross-section as a function of
the angle of the spontaneous photon emission for the higher numbers of
resonance ($r = 2, 3,... $) delineates a dependency with a sharp peak maximum
that coordinates to the particle radiation at the most probable frequency. To
summarize, the accomplished work represents that the resonant differential
cross-section acquires considerable magnitude. Thus, for the first resonance of
the channel A the resonant differential cross-section attains the $\sim
10^{12}$ order of a magnitude, and for the third resonance of the channel B
$\sim 10^5$ order of a magnitude (in the units of $\alpha Z^2 r_e^2$). Finally,
numerous scientific facilities with specialization in pulsed laser radiation
(SLAC, FAIR, XFEL, ELI, XCELS) may experimentally verify the constructed model
calculations.",2004.02247v1
2020-12-16,Perfectly-reflecting guided-mode-resonant photonic lattices possessing Mie modal memory,"Resonant periodic nanostructures provide perfect reflection across small or
large spectral bandwidths depending on the choice of materials and design
parameters. This effect has been known for decades, observed theoretically and
experimentally via one-dimensional and two-dimensional structures commonly
known as resonant gratings, metamaterials, and metasurfaces. The physical cause
of this extraordinary phenomenon is guided-mode resonance mediated by lateral
Bloch modes excited by evanescent diffraction orders in the subwavelength
regime. In recent years, hundreds of papers have declared Fabry-Perot or Mie
resonance to be basis of the perfect reflection possessed by periodic
metasurfaces. Treating a simple one-dimensional cylindrical-rod lattice, here
we show clearly and unambiguously that Mie resonance does not cause perfect
reflection. In fact, the spectral placement of the Bloch-mode-mediated
zero-order reflectance is primarily controlled by the lattice period by way of
its direct effect on the homogenized effective-medium refractive index of the
lattice. In general, perfect reflection appears away from Mie resonance.
However, when the lateral leaky-mode field profiles approach the
isolated-particle Mie field profiles, the resonance locus tends towards the Mie
resonance wavelength. The fact that the lattice fields remember the isolated
particle fields is referred here as Mie modal memory. On erasure of the Mie
memory by an index-matched sublayer, we show that perfect reflection survives
with the resonance locus approaching the homogenized effective-medium waveguide
locus. The results presented here will aid in clarifying the physical basis of
general resonant photonic lattices.",2012.09321v1
2020-12-23,Domino cooling of a coupled mechanical-resonator chain via cold-damping feedback,"We propose a domino-cooling method to realize simultaneous ground-state
cooling of a coupled mechanical-resonator chain through an optomechanical
cavity working in the unresolved-sideband regime. This domino-effect cooling is
realized by combining the cold-damping feedback on the first mechanical
resonator with nearest-neighbor couplings between other neighboring mechanical
resonators. We obtain analytical results for the effective susceptibilities,
noise spectra, final mean phonon numbers, and cooling rates of these mechanical
resonators, and find the optimal-cooling condition for these resonators.
Particularly, we analyze a two-mechanical-resonator case and find that by
appropriately engineering either the laser power or the feedback, a flexible
switch between symmetric and asymmetric ground-state cooling can be achieved.
This could be used for preparing symmetric quantum states in mechanical
systems. We also simulate the cooling performance of a coupled
$N$-mechanical-resonator chain and confirm that these resonators can be
simultaneously cooled to their quantum ground states in the unresolved-sideband
regime. Under proper parameter conditions, the cooling of the
mechanical-resonator chain shows a temperature gradient along the chain. This
study opens a route to quantum manipulation of multiple mechanical resonators
in the bad-cavity regime.",2012.12665v2
2012-05-07,Study of tunable resonances in laser beam divergence and beam deflection,"New, fundamental resonant properties of laser resonators are theoretically
predicted and experimentally demonstrated. These resonances occur either in the
time dependence of the beam width and that of beam radius of curvature of the
wavefront or in the time dependent pointing and position stability of the
output light beam of a laser resonator. The resonant frequency can be tuned
continuously from zero to the round-trip frequency in the first case; and from
zero to the half of the round-trip frequency in the second case, by for
example, moving one of the mirrors of the resonator. In both cases besides a
resonant frequency its complementary frequency to the round-trip frequency is
also resonant, and their shifted frequencies by multiples of the round-trip
frequency are also resonant. In our experimental demonstration we measured the
radiofrequency noise spectrum of the output laser beam, that was partially
blocked by a knife-edge. We observed increased noise at the theoretically
predicted frequencies. Similar resonances are predicted either in the time
dependent pulse-width and phase modulation or time jitter and the central
frequency of the ultrashort light pulses of the mode-locked lasers because of
the analogy between the space description of the light beams and the
time-description of the light pulses.",1205.1339v2
2018-08-30,Large scale changes in overtone resonances and resonant peak burning of HBAR with mass loading and its potential for applications,"This report presents the realization and characterization of a robust
composite resonator i.e. high overtone bulk acoustic wave resonator (HBAR) and
the changes happening to the resonance peaks once it undergoes mass loading
which has got the potential for application in material characterization,
communication system and sensing. Mass loading effect on a HBAR based on
BaxSr1-xTiO3 (BST) have been demonstrated by coating photoresist of various
thicknesses and characterization of resonance modes present in the frequency
spectrum of the resonator. Upon investigation, HBAR proves to be one of the
most promising and robust systems for gravimetric sensing. Burning effect in
the resonances occurs and it shifts significantly according to the amount of
mass loaded (increasing thickness of the photoresist coated) on the resonator
system. Some of the most important parameters like effective coupling
coefficient, spacing of parallel resonance frequency (SPRF) and quality factor
of the resonator and its numerous modes have been investigated meticulously.",1808.10118v2
2019-01-04,Permittivity and Conductivity Measured using a Novel Toroidal Split-Ring Resonator,"We describe and demonstrate the use of a novel toroidal split-ring resonator
to make accurate and precise measurements of the permittivity of liquids and
gases. We first analytically show how the resonance frequency and quality
factor of the resonator are related to the complex permittivity of the material
filling its gap. We then use the resonator to experimentally determine the
permittivity of a number of different materials. First, the compact and high-Q
resonator is used to measure both the real and imaginary parts of the complex
permittivity of methyl alcohol at 185 MHz. Second, the resonator was placed
inside a vacuum-tight Dewar. We measured the resonance frequency with the
resonator suspended in vacuum and then immersed in an atmosphere of air. From
these data, the dielectric constant of air was accurately determined. Next, the
resonator was submerged in liquid nitrogen and the boiling temperature of the
nitrogen bath was manipulated by regulating its vapor pressure. This system
allowed for a precise measurement of the dielectric constant of liquid nitrogen
over a temperature range of 64 to 77 K. Finally, we monitored the quality
factor of the copper resonator as its temperature drifted from 80 K to room
temperature. From these data, we extracted the linear temperature dependence of
copper's resistivity.",1901.00994v1
2019-08-30,Dynamical generation of resonances in the P33 partial wave,"We investigate the formation of resonances in the P33 partial wave with the
emphasis on possible emergence of dynamically generated quasi-bound states as a
consequence of a strong $p$-wave pion attractive interaction in this partial
wave, as well as their possible interaction with the genuine quark excited
states. By using the Laurent-Pietarinen expansion we follow the evolution of
the $S$-matrix poles in the complex energy plane as a function of the
interaction strength. Already without introducing a genuine quark resonant
state, two physically interesting resonances emerge with pole masses around
1200 MeV and 1400 MeV, with the dominant $\pi N$ and $\pi\Delta$ component,
respectively. The added genuine resonant state in the $(1s)^3$ quark
configuration mixes with the lower dynamically generated resonance forming the
physical $\Delta(1232)$ resonance, and pushes the second dynamical resonance to
around 1500 MeV, which allows it to be identified with the $\Delta(1600)$
resonance. Adding a second resonant state with one quark promoted to the $2s$
orbit generates another pole whose evolution remains well separated from the
lower two poles. We calculate the helicity amplitudes at the pole and suggest
that their $Q^2$ dependence could be a decisive test to discriminate between
different models of the $\Delta(1600)$ resonance.",1908.11750v1
2020-08-31,Dust distribution around low-mass planets on converging orbits,"Super-Earths can form at large orbital radii and migrate inward due to tidal
interactions with the circumstellar disk. In this scenario, convergent
migration may occur and lead to the formation of resonant pairs of planets. We
explore the conditions under which convergent migration and resonance capture
take place, and what dynamical consequences can be expected on the dust
distribution surrounding the resonant pair. We combine hydrodynamic
planet--disk interaction models with dust evolution calculations to investigate
the signatures produced in the dust distribution by a pair of planets in
mean-motion resonances. We find that convergent migration takes place when the
outer planet is the more massive. However, convergent migration also depends on
the local properties of the disk, and divergent migration may result as well.
For similar disk parameters, the capture in low degree resonances (e.g., 2:1 or
3:2) is preferred close to the star where the resonance strength can more
easily overcome the tidal torques exerted by the gaseous disk. Farther away
from the star, convergent migration may result in capture in high degree
resonances. The dust distribution shows potentially observable features
typically when the planets are trapped in a 2:1 resonance. In other cases, with
higher degree resonances (e.g., 5:4 or 6:5) dust features may not be
sufficiently pronounced to be easily observable. The degree of resonance
established by a pair of super-Earths may be indicative of the location in the
disk where capture occurred. There can be significant differences in the dust
distribution around a single super-Earth and a pair of super-Earths in
resonance.",2008.13464v1
2020-11-30,Resonances for Schrödinger operators on infinite cylinders and other products,"We study the resonances of Schr\""odinger operators on the infinite product
$X=\mathbb{R}^d\times \mathbb{S}^1$, where $d$ is odd, $\mathbb{S}^1$ is the
unit circle, and the potential $V\in L^\infty_c(X)$. This paper shows that at
high energy, resonances of the Schr\""odinger operator $-\Delta +V$ on
$X=\mathbb{R}^d\times \mathbb{S}^1$ which are near the continuous spectrum are
approximated by the resonances of $-\Delta +V_0$ on $X$, where the potential
$V_0$ given by averaging $V$ over the unit circle. These resonances are, in
turn, given in terms of the resonances of a Schr\""odinger operator on
$\mathbb{R}^d$ which lie in a bounded set. If the potential is smooth, we
obtain improved localization of the resonances, particularly in the case of
simple, rank one poles of the corresponding scattering resolvent on
$\mathbb{R}^d$. In that case, we obtain the leading order correction for the
location of the corresponding high energy resonances. In addition to direct
results about the location of resonances, we show that at high energies away
from the resonances, the resolvent of the model operator $-\Delta+V_0$ on $X$
approximates that of $-\Delta+V$ on $X$. If $d=1$, in certain cases this
implies the existence of an asymptotic expansion of solutions of the wave
equation. Again for the special case of $d=1$, we obtain a resonant rigidity
type result for the zero potential among all real-valued potentials.",2011.14513v2
2021-04-29,Resonant Chains of Exoplanets: Libration Centers for Three-body Angles,"Resonant planetary systems contain at least one planet pair with orbital
periods librating at a near-integer ratio (2/1, 3/2, 4/3, etc.) and are a
natural outcome of standard planetary formation theories. Systems with multiple
adjacent resonant pairs are known as resonant chains and can exhibit three-body
resonances -- characterized by a critical three-body angle. Here we study
three-body angles as a diagnostic of resonant chains through tidally-damped
N-body integrations. For each combination of the 2:1, 3:2, 4:3, and 5:4 mean
motion resonances (the most common resonances in the known resonant chains), we
characterize the three-body angle equilibria for several mass schemes,
migration timescales, and initial separations. We find that under our
formulation of the three-body angle, which does not reduce coefficients, 180
deg is the preferred libration center, and libration centers shifted away from
180 deg are associated with non-adjacent resonances. We then relate these
angles to observables, by applying our general results to two transiting
systems: Kepler-60 and Kepler-223. For these systems, we compare N-body models
of the three-body angle to the zeroth order in e approximation accessible via
transit phases, used in previous publications. In both cases, we find the
three-body angle during the Kepler observing window is not necessarily
indicative of the long-term oscillations and stress the role of dynamical
models in investigating three-body angles. We anticipate our results will
provide a useful diagnostic in the analysis of resonant chains.",2104.14665v1
2022-01-26,"Eviction-like resonances for satellite orbits. Application to Phobos, the main satellite of Mars","The motion of a satellite can experience secular resonances between the
precession frequencies of its orbit and the mean motion of the host planet
around the star. Some of these resonances can significantly modify the
eccentricity (evection resonance) and the inclination (eviction resonance) of
the satellite. In this paper, we study in detail the secular resonances that
can disturb the orbit of a satellite, in particular the eviction-like ones.
Although the inclination is always disturbed while crossing one eviction-like
resonance, capture can only occur when the semi-major axis is decreasing. This
is, for instance, the case of Phobos, the largest satellite of Mars, that will
cross some of these resonances in the future because its orbit is shrinking
owing to tidal effects. We estimate the impact of resonance crossing in the
orbit of the satellite, including the capture probabilities, as a function of
several parameters, such as the eccentricity and the inclination of the
satellite, and the obliquity of the planet. Finally, we use the method of the
frequency map analysis to study the resonant dynamics based on stability maps,
and we show that some of the secular resonances may overlap, which leads to
chaotic motion for the inclination of the satellite.",2201.10708v1
2022-04-06,Asymptotics of the meta-atom: plane wave scattering by a single Helmholtz resonator,"Using a combination of multipole methods and the method of matched
asymptotics, we present a solution procedure for acoustic plane wave scattering
by a single Helmholtz resonator in two dimensions. Closed-form representations
for the multipole scattering coefficients of the resonator are derived, valid
at low frequencies, with three fundamental configurations examined in detail:
the thin-walled, moderately thick-walled, and very thick-walled limits.
Additionally, we examine the impact of dissipation for very thick-walled
resonators, and also numerically evaluate the scattering, absorption, and
extinction cross sections (efficiencies) for representative resonators in all
three wall thickness regimes. In general, we observe strong enhancement in both
the scattered fields and cross sections at the Helmholtz resonance frequencies.
As expected, dissipation is shown to shift the resonance frequency, reduce the
amplitude of the field, and reduce the extinction efficiency at the fundamental
Helmholtz resonance. Finally, we confirm results in the literature on
Willis-like coupling effects for this resonator design, and crucially, connect
these findings to earlier works by the authors on two-dimensional arrays of
resonators, deducing that depolarisability effects (off-diagonal terms) for a
single resonator do not ensure the existence of Willis coupling effects
(bianisotropy) in bulk.",2204.02840v1
2022-05-23,Dynamical essence of the eccentric von Zeipel-Lidov-Kozai effect in restricted hierarchical planetary systems,"Aim. The eccentric von Zeipel-Lidov-Kozai (ZLK) effect is widely used to
explain dynamical phenomena in varieties of astrophysical systems. The purpose
of this work is to make clear the dynamical essence of the eccentric ZLK effect
by constructing an inherent connection between such an effect and dynamics of
secular resonance in restricted hierarchical planetary systems. Methods.
Dynamical structures of apsidal resonance are analytically studied by means of
perturbative treatments. The resonant model is formulated by averaging the
Hamiltonian (up to octupole order) over rotating ZLK cycles, producing an
additional motion integral. The phase portraits under the resonant model can be
used to analyse dynamical structures, including resonant centres, dynamical
separatrices and islands of libration. Results. By analysing phase portraits,
five branches of libration centres and eight libration zones are found in the
eccentricity--inclination space. There is an excellent agreement between
analytical results of libration zone and numerical distributions of resonant
orbit, indicating that the resonant model for apsidal resonances is valid and
applicable. Additionally, it is found that, in the test-particle limit,
distributions of flipping orbits are dominated by those apsidal resonances
centred at the inclination of i = 90 deg. Conclusions. The eccentric ZLK effect
is dynamically equivalent to the effect of apsidal resonance in restricted
hierarchical planetary systems. The dynamical response of the eccentric ZLK
effect (or effect of apsidal resonance) is to significantly excite
eccentricities and/or inclinations of test particles in the very long-term
evolution.",2205.11238v1
2022-06-02,Mechanical dissipation by substrate-mode coupling in SiN resonators,"State-of-the-art nanomechanical resonators are heralded as a central
component for next-generation clocks, filters, resonant sensors and quantum
technologies. To practically build these technologies will require monolithic
integration of microchips, resonators and readout systems. While it is widely
seen that mounting microchip substrates into a system can greatly impact the
performance of high-Q resonators, a systematic study has remained elusive,
owing to the variety of physical processes and factors that influence the
dissipation. Here, we analytically analyze a mechanism by which substrates
couple to resonators manufactured on them, and experimentally demonstrate that
this coupling can increase the mechanical dissipation of nanomechanical
resonators when the resonance frequencies of resonator and substrate coincide.
More generally, we then show a similar coupling mechanism can exist between two
adjacent resonators. Since the substrate-mode coupling mechanism strongly
depends on both the resonator position on the substrate and the mounting of the
substrate, this work provides key design guidelines for high-precision
nanomechanical technologies.",2206.00990v2
2023-05-19,Analytic evaluation of non-adiabatic couplings within the complex absorbing potential equation-of-motion coupled-cluster method,"We present the theory for the evaluation of non-adiabatic couplings (NACs)
involving resonance states within the complex absorbing potential
equation-of-motion coupled-cluster (CAP-EOM-CC) framework implemented within
the singles and doubles approximation. Resonance states are embedded in the
continuum and undergo rapid decay through autodetachment. In addition, nuclear
motions can facilitate transitions between different resonances and between
resonances and bound states. These non-adiabatic transitions affect the
chemical fate of resonances and have distinct spectroscopic signatures. The NAC
vector is a central quantity needed to model such effects.
  In the CAP-EOM-CC framework, resonance states are treated on the same footing
as bound states. Using the example of fumaronitrile, which supports a bound
radical anion and several anionic resonances, we analyze the non-adiabatic
coupling between bound states and pseudocontinuum states, between bound states
and resonances and between two resonances. We find that the NAC between a bound
state and a resonance is nearly independent of the CAP strength and thus
straightforward to evaluate whereas the NAC between two resonance states or
between a bound state and a pseudocontinuum state is more difficult to
evaluate.",2305.11724v2
2023-07-20,The loop-zag resonator: A loop-gap resonator design for improved sensitivity in electron-spin resonance experiments,"We present a novel design of loop-gap resonator, the loop-zag resonator, for
sub-X-band electron-spin resonance spectroscopy. The loop-zag design can
achieve improved coupling to small-sample spin systems through the improvement
of sample filling factor and RF $B_1$ field. By introducing ``zags'' to the
resonator's gap path, the capacitance is increased, accommodating a smaller
loop size and thereby a larger filling factor to maintain the requisite
resonant frequency. We present experimental spectra on five different
resonators, each with approximately the same resonant frequency of
$\sim2.9$~GHz, showing that an increase in the number of zags and reduction in
loop size gives rise to higher sensitivity. Finite-element simulations of these
resonators provide estimates of the improved filling factors obtained through
the addition of zags. The frequency range over which this loop-zag design is
practical enables a breadth of future applications in microwave engineering,
including ESR and ESR-like quantum information microwave techniques.",2307.11269v1
2023-08-15,Inner-scaled Helmholtz resonators with grazing turbulent boundary layer flow,"Response details are presented of small-scale Helmholtz resonators excited by
grazing turbulent boundary layer flow. A particular focus lies on scaling of
the resonance, in relation to the spatio-temporal characteristics of the
near-wall velocity and wall-pressure fluctuations. Resonators are tuned to
different portions of the inner-spectral peak of the boundary-layer
wall-pressure spectrum, at a spatial scale of $\lambda_x^+ \approx 250$ (or
temporal scale of $T^+ \approx 25$). Following this approach, small-scale
resonators can be designed with neck-orifice diameters of minimum intrusiveness
to the grazing flow. Here we inspect the TBL response by analysing velocity
data obtained with hot-wire anemometry and particle image velocimetry
measurements. This strategy follows the earlier work by Panton and Miller (J.
Acoust. Soc. Am. 526, 800, 1975) in which only the change in resonance
frequency, due to the grazing flow turbulence, was examined. Single resonators
are examined in a boundary layer flow at $Re_\tau \approx 2\,280$. Two
neck-orifice diameters of $d^+ \approx 68$ and 102 are considered, and for each
value of $d^+$ three different resonance frequencies are studied (targeting the
spatial scale of $\lambda_x^+ \approx 250$, as well as sub- and
super-wavelengths). Passive resonance only affects the streamwise velocity
fluctuations in the region $y^+ \lesssim 25$, while the vertical velocity
fluctuations are seen in a layer up to $y^+ \approx 100$. A narrow-band
increase in streamwise turbulence kinetic energy at the resonance scale
co-exists with a more than 20% attenuation of lower-frequency (larger scale)
energy. Current findings inspire further developments of passive surfaces that
utilize the concept of changing the local wall-impedance for boundary-layer
flow control, using miniature resonators as a meta-unit.",2308.07776v1
2024-01-16,Tracking Superharmonic Resonances for Nonlinear Vibration,"Many modern engineering structures exhibit nonlinear vibration.
Characterizing such vibrations efficiently is critical to optimizing designs
for reliability and performance. For linear systems, steady-state vibration
occurs only at the forcing frequencies. However, nonlinearities (e.g., contact,
friction, large deformation, etc.) can result in nonlinear vibration behavior
including superharmonics - responses at integer multiples of the forcing
frequency. When the forcing frequency is near an integer fraction of the
natural frequency, superharmonic resonance occurs, and the magnitude of the
superharmonics can exceed that of the fundamental harmonic that is externally
forced. Characterizing such superharmonic resonances is critical to improving
engineering designs. The present work extends the concept of phase resonance
nonlinear modes (PRNM) to be applicable to general nonlinearities, and is
demonstrated for eight different nonlinear forces. The considered forces
include stiffening, softening, contact, damping, and frictional nonlinearities
that have not been previously considered with PRNM. The proposed variable phase
resonance nonlinear modes (VPRNM) method can accurately track superharmonic
resonances for hysteretic nonlinearities that exhibit amplitude dependent phase
resonance conditions that cannot be captured by PRNM. The proposed method
allows for characterization of superharmonic resonances without constructing a
full frequency response curve at every force level with the harmonic balance
method. Thus, the present method allows for analysis of potential failures due
to large amplitudes near the superharmonic resonance with reduced computational
cost. The consideration of single degree of freedom systems in the present
paper provides insights into superharmonic resonances and a basis for
understanding internal resonances for multiple degree of freedom systems.",2401.08790v1
1998-05-27,Resonant relaxation in protoplanetary disks,"Resonant relaxation is a novel form of two-body relaxation that arises in
nearly Keplerian disks such as protoplanetary disks. Resonant relaxation does
not affect the semimajor axes of the particles, but enhances relaxation of
particle eccentricities and inclinations. The equilibrium state after resonant
relaxation is a Rayleigh distribution, with the mean-square eccentricity and
inclination inversely proportional to mass. The rate of resonant relaxation
depends strongly on the precession rate of the disk. If the precession due to
the disk's self-gravity is small compared to the total precession, then the
relaxation is concentrated near the secular resonance between each pair of
interacting bodies; on the other hand if the precession rate is dominated by
the disk's self-gravity then relaxation occurs through coupling to the
large-scale low-frequency m=1 normal modes of the disk. Depending on the disk
properties, resonant relaxation may be either stronger or weaker than the usual
non-resonant relaxation.",9805334v1
2001-12-19,A non-linear theory of vertical resonances in accretion discs,"An important and widely neglected aspect of the interaction between an
accretion disc and a massive companion with a coplanar orbit is the vertical
component of the tidal force. As shown by Lubow, the response of the disc to
vertical forcing is resonant at certain radii, at which a localized torque is
exerted, and from which a compressive wave (p mode) may be emitted. Although
these vertical resonances are weaker than the corresponding Lindblad
resonances, the m=2 inner vertical resonance in a binary star is typically
located within the tidal truncation radius of a circumstellar disc.
  In this paper I develop a general theory of vertical resonances, allowing for
non-linearity of the response, and dissipation by radiative damping and
turbulent viscosity. The problem is reduced to a universal, non-linear ordinary
differential equation with two real parameters. Solutions of the complex
non-linear Airy equation are presented to illustrate the non-linear saturation
of the resonance and the effects of dissipation. It is argued that the m=2
inner vertical resonance is unlikely to truncate the disc in cataclysmic
variable stars, but contributes to angular momentum transport and produces a
potentially observable non-axisymmetric structure.",0112443v1
2004-06-21,A search for cyclotron resonance features with INTEGRAL,"We present an INTEGRAL observation of the Cen-Crux region in order to search
the electron cyclotron resonance scattering features from the X-ray binary
pulsars. During the AO1 200ks observation, we clearly detected 4 bright X-ray
binaries, 1 Seyfert Galaxy, and 4 new sources in the field of view. Especially
from GX301-2, the cyclotron resonance feature is detected at about 37 keV, and
width of 3--4 keV. In addition, the depth of the resonance feature strongly
depends on the X-ray luminosity. This is the first detection of luminosity
dependence of the resonance depth. The cyclotron resonance feature is
marginally detected from 1E1145.1-6141. Cen X-3 was very dim during the
observation and poor statistics disable us to detect the resonance
features.These are first INTEGRAL results of searching for the cyclotron
resonance feature.",0406449v1
2004-10-19,The Drag Induced Resonant Capture for Kuiper Belt Objects,"It has been an interesting question that why there are one-third of Kuiper
Belt Objects (KBOs) trapped into the 3:2 resonance but, in contrast, only
several KBOs are claimed to be associated with the 2:1 resonance. In a model
proposed by Zhou et al. (2002), the stochastic outward migration of the Neptune
could reduce the number of particles in the 2:1 resonance and thus the objects
in the 3:2 resonance become more distinct. As a complementary study, we
investigate the effect of proto-stellar discs on the resonance capture. Our
results show that the gaseous drag of a proto-stellar disc can trap KBOs into
the 3:2 resonance rather easily. In addition, no objects are captured into the
2:1 resonance in our simulation.",0410426v2
2005-06-29,Neutron Catalysis of Resonance Fusion in Stellar Matter,"Within the framework of resonance fusion study in stellar matter the features
of system consisted of two alpha particles and one neutron have been
investigated at astrophysical energies. Consideration of three body scattering
has been carried out on base of well-known Faddeev's equations. It is found
that under certain conditions the series of resonance states appear in this
system at very low energies. The lifetimes of these three body resonances are
close to the lifetime of unstable nucleus 8Be. The simple forms of two body
repulsive potentials are taken into account to describe the parameters of the
alpha, alpha resonance and to satisfy n, alpha scattering data at very low
energies. The explanation of resonance phenomena in n, alpha, alpha system is
offered on base of physical model. The effect results from resonance quantum
phenomena in few body dynamics. In turn, the resonance fusion can give
influence on many astrophysical phenomena. The possibility of catalyzing this
new mode of fusion by free neutrons in alpha particle matter is considered too.",0506734v2
2006-04-27,"Resonance scattering, absorption and off-centre abundance peaks in clusters of galaxies","A possible explanation for the central abundance dips found from
spatially-resolved X-ray spectroscopy of several groups and clusters of
galaxies is resonance scattering. A number of the prominent iron emission lines
are resonance lines. We construct a unique spectral model which takes account
of resonance scattering for several thousand resonance lines, projection
effects, photoelectric absorption, and allows direct spectral fitting. We apply
our model to Chandra observations of two clusters with pronounced central
abundance dips, Centaurus and Abell 2199. The results show that the effect of
resonance scattering on emission from the centre of the cluster can be as much
as 30 per cent for the Fe-K resonance lines, and 10 per cent for several Fe-L
lines, if turbulence is low. The change to the metallicities obtained by
fitting low resolution CCD spectra is at most 10 per cent. Accounting for
resonance scattering does not remove the central dip. Allowing for internal
absorption within the Centaurus significantly improves the quality of the fits,
indicating the presence of absorbing material within the inner 40 kpc of NGC
4696.",0604575v1
2006-05-18,Resonant Relaxation near the Massive Black Hole in the Galactic Center,"The coherent torques between stars on orbits near massive black holes (MBHs)
lead to resonant angular momentum relaxation. Due to the fact that orbits are
Keplerian to good approximation, the torques efficiently change the magnitude
of the angular momenta and rotate the orbital inclinations. As a result the
stars are rapidly randomized. The galactic MBH is a good system for the
observational study of resonant relaxation. The age of the young B-stars at a
distance of $\sim0.01 pc$ from the MBH is comparable to the resonant relaxation
time, implying that resonant relaxation may have played an important role in
their dynamical structure. In contrast, the O-stars in the stellar disks at
$\sim0.1 pc$ are younger than the resonant relaxation time, as required by
their dynamical coherence. Resonant relaxation dynamics dominates the event
rate of gravitational wave (GW) emission from inspiraling stars into MBHs of
masses comparable to the Galactic MBH. Resonant relaxation leads to rates
$\lesssim 10$ times higher than those predicted by 2-body relaxation, which
would improve the prospects of detecting these events by future GW detectors,
such as LISA.",0605457v1
2001-07-26,Band structure approach to the resonant x-ray scattering,"We study the resonance behaviour of the forbidden 600 and 222 x-ray Bragg
peaks in Ge using LDA band structure methods. These Bragg peaks remain
forbidden in the resonant dipole scattering approximation even taking into
account the non local nature of the band states. However they become allowed at
resonance if the eigenstates of the unoccupied conduction band involve a
hybridization of p like and d like atomic states. We show that the energy
dependence of the resonant behaviour, including the phase of the scattering, is
a direct measure of this p-d hybridization.and obtain quantitative agreement
with experiment. A simple physical picture involving a product of dipole and
quadrupolar transition matrix elements explains this behaviour and shows that
it should be generally true for cases where the resonating atom is not at an
inversion center. This has strong implications for the description of the
resonance behavior of x-ray scattering in materials where the resonant atom is
not at an inversion center such as V2O3 and in ferro and antiferro electric and
piezo electric materials in general.",0107546v1
2002-09-18,Isolated resonances in conductance fluctuations in ballistic billiards,"We study numerically quantum transport through a billiard with a classically
mixed phase space. In particular, we calculate the conductance and Wigner delay
time by employing a recursive Green's function method. We find sharp, isolated
resonances with a broad distribution of resonance widths in both the
conductance and the Wigner time, in contrast to the well-known smooth
conductance fluctuations of completely chaotic billiards. In order to elucidate
the origin of the isolated resonances, we calculate the associated scattering
states as well as the eigenstates of the corresponding closed system. As a
result, we find a one-to-one correspondence between the resonant scattering
states and eigenstates of the closed system. The broad distribution of
resonance widths is traced to the structure of the classical phase space.
Husimi representations of the resonant scattering states show a strong overlap
either with the regular regions in phase space or with the hierarchical parts
surrounding the regular regions. We are thus lead to a classification of the
resonant states into regular and hierarchical, depending on their phase space
portrait.",0209433v1
2003-05-11,Feshbach resonances in a quasi-2D atomic gas,"Strongly confining an ultracold atomic gas in one direction to create a
quasi-2D system alters the scattering properties of this gas. We investigate
the effects of confinement on Feshbach scattering resonances and show that
strong confinement results in a shift in the position of the Feshbach resonance
as a function of the magnetic field. This shift, as well as the change of the
width of the resonance, are computed. We find that the resonance is strongly
damped in the thermal gas, but in the condensate the resonance remains sharp
due to many-body effects. We introduce a 2D model system, suited for the study
of resonant superfluidity, and having the same scattering properties as the
tightly confined real system near a Feshbach resonance. Exact relations are
derived between measurable quantities and the model parameters.",0305235v1
2003-07-15,Resonant and anti-resonant frequency dependence of the effective parameters of metamaterials,"We present a numerical study of the electromagnetic response of the
metamaterial elements that are usedto construct materials with negative
refractive index. For an array of split ring resonators (SRR) we find that the
resonant behavior of the effective magnetic permeability is accompanied by an
anti-resonant behavior of the effective permittivity. In addition, the
imaginary parts of the effective permittivity and permeability are opposite in
sign. We also observe an identical resonant versus anti-resonant frequency
dependence of the effective materials parameters for a periodic array of thin
metallic wires with cuts placed periodically along the length of the wire, with
roles of the permittivity and permeability reversed from the SRR case. We show
in a simple manner that the finite unit cell size is responsible for the
anti-resonant behavior.",0307361v1
2005-06-16,Noise properties of two single electron transistors coupled by a nanomechanical resonator,"We analyze the noise properties of two single electron transistors (SETs)
coupled via a shared voltage gate consisting of a nanomechanical resonator.
Working in the regime where the resonator can be treated as a classical system,
we find that the SETs act on the resonator like two independent heat baths. The
coupling to the resonator generates positive correlations in the currents
flowing through each of the SETs as well as between the two currents. In the
regime where the dynamics of the resonator is dominated by the back-action of
the SETs, these positive correlations can lead to parametrically large
enhancements of the low frequency current noise. These noise properties can be
understood in terms of the effects on the SET currents of fluctuations in the
state of a resonator in thermal equilibrium which persist for times of order
the resonator damping time.",0506397v2
2006-04-07,Optimal conversion of Bose condensed atoms into molecules via a Feshbach resonance,"In many experiments involving conversion of quantum degenerate atomic gases
into molecular dimers via a Feshbach resonance, an external magnetic field is
linearly swept from above the resonance to below resonance. In the adiabatic
limit, the fraction of atoms converted into molecules is independent of the
functional form of the sweep and is predicted to be 100%. However, for
non-adiabatic sweeps through resonance, Landau-Zener theory predicts that a
linear sweep will result in a negligible production of molecules. Here we
employ a genetic algorithm to determine the functional time dependence of the
magnetic field that produces the maximum number of molecules for sweep times
that are comparable to the period of resonant atom-molecule oscillations,
$2\pi\Omega_{Rabi}^{-1}$. The optimal sweep through resonance indicates that
more than 95% of the atoms can be converted into molecules for sweep times as
short as $2\pi\Omega_{Rabi}^{-1}$ while the linear sweep results in a
conversion of only a few percent. We also find that the qualitative form of the
optimal sweep is independent of the strength of the two-body interactions
between atoms and molecules and the width of the resonance.",0604216v2
2006-06-28,Dissipation in Single-Crystal 3C-SiC Ultra-High Frequency Nanomechanical Resonators,"The energy dissipation 1/Q (where Q is the quality factor) and resonance
frequency characteristics of single-crystal 3C-SiC ultrahigh frequency (UHF)
nanomechanical resonators are measured, for a family of UHF resonators with
resonance frequencies of 295MHz, 395MHz, 411MHz, 420MHz, 428MHz, and 482MHz. A
temperature dependence of dissipation, 1/Q ~ T^(0.3) has been identified in
these 3C-SiC devices. Possible mechanisms that contribute to dissipation in
typical doubly-clamped beam UHF resonators are analyzed. Device size and
dimensional effects on the dissipation are also examined. Clamping losses are
found to be particularly important in these UHF resonators. The resonance
frequency decreases as the temperature is increased, and the average frequency
temperature coefficient is about -45ppm/K.",0606711v1
2006-11-02,Signal amplification in a nanomechanical Duffing resonator via stochastic resonance,"We experimentally study stochastic resonance in a nonlinear bistable
nanomechanical resonator. The device consists of a PdAu doubly clamped beam
serving as a nanomechanical resonator excited capacitively by an adjacent gate
electrode and its vibrations are detected optically. The resonator is tuned to
its bistability region by an intense pump near a point of equal transition
rates between its two metastable states. The pump is amplitude modulated,
inducing modulation of the activation barrier between the states. When noise is
added to the excitation, the resonator's displacement exhibits noise dependent
amplification. We measure the resonator's response in the time and frequency
domains, the spectral amplification and the statistical distribution of the
jump time.",0611049v1
2001-10-11,Hadronic Regge Trajectories in the Resonance Energy Region,"Nonlinearity of hadronic Regge trajectories in the resonance energy region
has been proved.",0110160v1
2005-04-13,Sterile-active neutrino oscillations and shortcuts in the extra dimension,"We discuss a possible new resonance in active-sterile neutrino oscillations
arising in theories with large extra dimensions. Fluctuations in the brane
effectively increase the path-length of active neutrinos relative to the
path-length of sterile neutrinos through the extra-dimensional bulk. Well below
the resonance, the standard oscillation formulas apply. Well above the
resonance, active-sterile oscillations are suppressed. We show that a resonance
energy in the range of 30-400 MeV allows an explanation of all neutrino
oscillation data, including LSND data, in a consistent four-neutrino model. A
high resonance energy implies an enhanced signal in MiniBooNE. A low resonance
energy implies a distorted energy spectrum in LSND, and an enhanced v_mu
depletion from a stopped-pion source. The numerical value of the resonance
energy may be related back to the geometric aspects of the brane world. Some
astrophysical and cosmological consequences of the brane-bulk resonance are
briefly sketched.",0504096v3
2004-01-21,Resonance tongues and patterns in periodically forced reaction-diffusion systems,"Various resonant and near-resonant patterns form in a light-sensitive
Belousov-Zhabotinsky (BZ) reaction in response to a spatially-homogeneous
time-periodic perturbation with light. The regions (tongues) in the forcing
frequency and forcing amplitude parameter plane where resonant patterns form
are identified through analysis of the temporal response of the patterns.
Resonant and near-resonant responses are distinguished. The unforced BZ
reaction shows both spatially-uniform oscillations and rotating spiral waves,
while the forced system shows patterns such as standing-wave labyrinths and
rotating spiral waves. The patterns depend on the amplitude and frequency of
the perturbation, and also on whether the system responds to the forcing near
the uniform oscillation frequency or the spiral wave frequency. Numerical
simulations of a forced FitzHugh-Nagumo reaction-diffusion model show both
resonant and near-resonant patterns similar to the BZ chemical system.",0401031v1
2006-11-10,Vibrational and stochastic resonances in two coupled overdamped anharmonic oscillators,"We study the overdamped version of two coupled anharmonic oscillators under
the influence of both low- and high-frequency forces respectively and a
Gaussian noise term added to one of the two state variables of the system. The
dynamics of the system is first studied in the presence of both forces
separately without noise. In the presence of only one of the forces, no
resonance behaviour is observed, however, hysteresis happens there. Then the
influence of the high-frequency force in the presence of a low-frequency, i.e.
biharmonic forcing, is studied. Vibrational resonance is found to occur when
the amplitude of the high-frequency force is varied. The resonance curve
resembles a stochastic resonance-like curve. It is maximum at the value of $g$
at which the orbit lies in one well during one half of the drive cycle of the
low-frequency force and in the other for the remaining half cycle. Vibrational
resonance is characterized using the response amplitude and mean residence
time. We show the occurrence of stochastic resonance behaviour in the
overdamped system by replacing the high-frequency force by Gaussian noise.
Similarities and differences between both types of resonance are presented.",0611023v1
1995-12-13,Model for Resonance Enhancement of P- and T-noninvariant Effects in Neutron Reactions,"We consider a simplified model for resonant neutron-nucleus interaction with
coupled channels. An analytical solution is given for two coupled channels and
arbitrary neutron orbital momentum. A case of a week channel coupling,
corresponding to narrow Breit-Wigner resonance, is analyzed in details. As far
as the total width of a resonance coincides with the neutron width, the model
is directly appropriate only for light nuclei. We study a mixing of two narrow
s- and p-wave resonances by P- and P-,T-noninvariant potentials in the first
order of perturbation theory. As an example a close-lying pair of s- and p-wave
resonances of the $^{35}$Cl nucleus is considered. The favorable possibilities
are shown to exist on thick targets for measurements beyond the resonance
widths. In particular, an interference minimum near s-wave resonance is of
interest for P-odd neutron spin rotation on light spinless nuclei.",9512020v2
1998-01-03,Instanton tunneling and multiphonon giant resonances,"The sine-Gordon model is applied to describe the multiphonon giant
resonances.",9801002v1
1998-12-19,Photoproduction of the Lambda(1405) on the proton and nuclei,"We study the gamma p ---> K^+ Lambda(1405) reaction at energies close to
threshold using a chiral unitary model where the resonance is generated
dynamically from K^-p interaction with other channels constructed from the
octets of baryons and mesons. Predictions are made for cross sections into
several channels and it is shown that the detection of the K^+ is sufficient to
determine the shape and strength of the Lambda(1405) resonance. The
determination of the resonance properties in nuclei requires instead the
detection of the resonance decay channels. Pauli blocking effects on the
resonance, which have been shown to be very important for the resonance at rest
in the nucleus, are irrelevant here where the resonance is produced with a
large momentum. The nuclear modifications here would thus offer information on
the resonance and K^- nucleus dynamics complementary to the one offered so far
by K^- atoms.",9812055v1
2002-07-17,Exploration of Resonant Continuum and Giant Resonance in the Relativistic Approach,"Single-particle resonant-states in the continuum are determined by solving
scattering states of the Dirac equation with proper asymptotic conditions in
the relativistic mean field theory (RMF). The regular and irregular solutions
of the Dirac equation at a large radius where the nuclear potentials vanish are
relativistic Coulomb wave functions, which are calculated numerically.
Energies, widths and wave functions of single-particle resonance states in the
continuum for ^{120}Sn are studied in the RMF with the parameter set of NL3.
The isoscalar giant octupole resonance of ^{120}Sn is investigated in a fully
consistent relativistic random phase approximation. Comparing the results with
including full continuum states and only those single-particle resonances we
find that the contributions from those resonant-states dominate in the nuclear
giant resonant processes.",0207054v1
2004-06-16,The N(1710)P11 state is confirmed in the re-analysis of the pi N --> K Lambda production; it is a good candidate for a non-strange pentaquark,"Re-analyzing the old pi N --> K Lambda data, the additional proof is given
for the existence of the N(1710) P11 state, critically needed in light of
reported observations of exotic Theta(1539) and Xi(1862) pentaquarks. An
existing single-resonance model with S11, P11 and P13 Breit-Wiegner resonances
in the s-channel has been applied. It has been shown that the standard set of
resonant parameters fails to reproduce the shape of the differential cross
section. The new resonance parameter determination has been performed keeping
in mind the most recent knowledge about nucleon resonances. The extracted set
of parameters has confirmed the need for the strong contribution of a N(1710)
P11 resonance. The need for any significant contribution of the P13 resonance
has been eliminated. To reproduce the total cross section at the same time with
the linear dependence of the differential cross sections with the cos(theta) in
the energy range 1650 MeV < W < 1800 MeV the P11 resonance can not but be quite
narrow.",0406055v2
2005-05-17,Hadron production from resonance decay in relativistic collisions,"A statistical model for decay and formation of heavy hadronic resonances is
formulated. The resonance properties become increasingly uncertain with
increasing resonance mass. Drawing on analogy with the situation in low-energy
nuclear physics, we employ the Weisskopf approach to the resonance processes.
In the large-mass limit, the density of resonance states in mass is governed by
a universal Hagedorn-like temperature T_H. As resonances decay, progressively
more and more numerous lighter states get populated. For T_H \simeq 170 MeV,
the model describes data for the hadron yield ratios at the RHIC and SPS
energies under the extreme assumption of a single heavy resonance giving rise
to measured yields.",0505049v2
2004-09-06,Enzyme as a thermal resonance pump,"We found latent periodicity of 150 protein families now. We suppose that
latent periodicity can determine a spectrum of resonance oscillations in
proteins.",0409009v1
2000-10-01,Phase-space picture of resonance creation and avoided crossings,"Complex coordinate scaling (CCS) is used to calculate resonance eigenvalues
and eigenstates for a system consisting of an inverted Gaussian potential and a
monochromatic driving field. Floquet eigenvalues and Husimi distributions of
resonance eigenfunctions are calculated using two different versions of CCS.
The number of resonance states in this system increases as the strength of the
driving field is increased, indicating that this system might have increased
stability against ionization when the field strength is very high. We find that
the newly created resonance states are scarred on unstable periodic orbits of
the classical motion. The behavior of these periodic orbits as the field
strength is increased may explain why there are more resonance states at high
field strengths than at low field strengths. Close examination of an avoided
crossing between resonance states shows that this type of avoided crossing does
not delocalize the resonance states, although it may lead to interesting
effects at certain field strengths.",0010003v1
2003-09-23,Buffer-gas induced absorption resonances in Rb vapor,"We observe transformation of the electromagnetically induced transparency
(EIT) resonance into the absorption resonance in a $\Lambda$ interaction
configuration in a cell filled with $^{87}$Rb and a buffer gas. This
transformation occurs as a one-photon detuning of the coupling fields is varied
from the atomic transition. No such absorption resonance is found in the
absence of a buffer gas. The width of the absorption resonance is several times
smaller than the width of the EIT resonance, and the changes of absorption near
these resonances are about the same. Similar absorption resonances are detected
in the Hanle configuration in a buffered cell.",0309171v2
2006-11-25,Resonance phenomena in Macroscopic Quantum Tunneling: the small viscosity limit,"We present a new theoretical approach to describe the quantum behavior of a
macroscopic system interacting with an external irradiation field, close to the
resonant condition. Here we consider the extremely underdamped regime for a
system described by a double well potential. The theory includes both:
transitions from one well to the other and relaxation processes. We simulate
resonant phenomena in a rf-SQUID, whose parameters lie in the range typically
used in the experiments. The dependence of the transition probability W on the
external drive of the system $\phi_x$ shows three resonance peaks. One peak is
connected with the resonant tunneling and the two others with the resonant
pumping. The relative position of the two peaks correlated to the resonant
pumping depends on the pumping frequency $\nu$ and on the system parameters.
The preliminary measurements on our devices show a low dissipation level and
assure that they are good candidates in order to realize new experiments on the
resonant phenomena in the presence of an external microwave irradiation of
proper frequency.",0611255v1
2007-07-29,On dynamical tunneling and classical resonances,"This work establishes a firm relationship between classical nonlinear
resonances and the phenomenon of dynamical tunneling. It is shown that the
classical phase space with its hierarchy of resonance islands completely
characterizes dynamical tunneling and explicit forms of the dynamical barriers
can be obtained only by identifying the key resonances. Relationship between
the phase space viewpoint and the quantum mechanical superexchange approach is
discussed in near-integrable and mixed regular-chaotic situations. For
near-integrable systems with sufficient anharmonicity the effect of multiple
resonances {\it i.e.,} resonance-assisted tunneling can be incorporated
approximately. It is also argued that the, presumed, relation of avoided
crossings to nonlinear resonances does not have to be invoked in order to
understand dynamical tunneling. For molecules with low density of states the
resonance-assisted mechanism is expected to be dominant.",0707.4274v1
2007-07-30,Ultracold collisions in magnetic fields: reducing inelastic cross sections near Feshbach resonances,"We have carried out bound-state and low-energy quantum scattering
calculations on He + NH (triplet Sigma) in magnetic fields, with the NH
molecule in its n=1 rotationally excited states. We have explored the pattern
of levels as a function of magnetic field and identified the nearly good
quantum numbers in different regimes. We have used the bound-state calculations
to locate low-energy Feshbach resonances. When the magnetic field is used to
tune across such a resonance, the real and imaginary part of the scattering
length show asymmetric oscillations and peaks with amplitude between 1 and 3
Angstroms. The scattering length does not pass through a pole at resonance. The
resonant behavior is characterized by a complex resonant scattering length
a_res. The corresponding inelastic cross sections show troughs as well as peaks
near resonance. This may be important for efforts to achieve evaporative and
sympathetic cooling for molecules, because it offers the hope that inelastic
trap losses can be reduced by tuning close to a Feshbach resonance.",0707.4397v1
2007-11-11,Saturated absorption spectroscopy: elimination of crossover resonances by use of a nanocell,"It is demonstrated that velocity selective optical pumping/saturation
resonances of reduced absorption in a Rb vapor nanocell with thickness
\textit{L=} $\lambda $, 2$\lambda $, and 3$\lambda $ (resonant wavelength
$\lambda $ = 780 nm) allow the complete elimination of crossover (CO)
resonances. We observe well pronounced resonances corresponding to the
F$_{g}=3$ $\to $ F$_{e}=2,3,4$ hyperfine transitions of the $^{85}$Rb D$_{2}$
line with linewidths close to the natural width. A small CO resonance located
midway between F$_{g}=3$ $\to $ F$_{e}=3$ and F$_{g}=3$ $\to$ F$_{e}=4$
transitions appears only for \textit{L} = 4$\lambda $. The D$_{2}$ line
($\lambda $ = 852 nm) in a Cs nanocell exhibits a similar behavior. From the
amplitude ratio of the CO and VSOP resonances it is possible to determine the
thickness of the column of alkali vapor in the range of 1 - 1000 $\mu $m. The
absence of CO resonances for nanocells with $L \sim \lambda $ is attractive for
frequency reference application and for studying transitions between Zeeman
sublevels in external magnetic fields.",0711.1684v1
2007-12-11,Resonance production in heavy-ion collisions at STAR,"Hadronic resonances are sensitive to the properties of a hot and dense medium
created in a heavy ion collisions. During the hadronic phase, after
hadronization of quark and gluons into hadrons, resonances are useful to
determine the lifetime between chemical and thermal freeze-out, under the
assumption that the re-scattering of the decay particles and the probability of
regeneration of resonances from hadrons depends on the system properties and
the resonance lifetime. The system size and energy dependence of resonance
spectra and yields will be shown and discussed in the context of the lifetime
and size of the hadronic phase. Elliptic flow measurement will extend the
sensitivity of resonance yields to the partonic state through additional
information on constituent quark scaling. We also explore a possible new
technique to extract signals from the early, potentially chirally symmetric,
stage through the selection of resonances from jets.",0712.1838v1
2008-04-25,Coupled-resonator-induced reflection in photonic-crystal waveguide structures,"We study the resonant transmission of light in a coupled-resonator optical
waveguide interacting with two nearly identical side cavities. We reveal and
describe a novel effect of the coupled-resonator-induced reflection (CRIR)
characterized by a very high and easily tunable quality factor of the
reflection line, for the case of the inter-site coupling between the cavities
and the waveguide. This effect differs sharply from the
coupled-resonator-induced transparency (CRIT) -- an all-optical analogue of the
electromagnetically-induced transparency -- which has recently been studied
theoretically and observed experimentally for the structures based on
micro-ring resonators and photonic crystal cavities. Both CRIR and CRIT effects
have the same physical origin which can be attributed to the Fano-Feshbach
resonances in the systems exhibiting more than one resonance. We discuss the
applicability of the novel CRIR effect to the control of the slow-light
propagation and low-threshold all-optical switching.",0804.4140v1
2008-11-08,Ballistic Spin Resonance,"The phenomenon of spin resonance has had far reaching influence since its
discovery nearly 70 years ago. Electron spin resonance (ESR) driven by high
frequency magnetic fields has informed our understanding of quantum mechanics,
and finds application in fields as diverse as medicine and quantum information.
Spin resonance induced by high frequency electric fields, known as electric
dipole spin resonance (EDSR), has also been demonstrated recently. EDSR is
mediated by spin-orbit interaction (SOI), which couples the spin degree of
freedom and the momentum vector. Here, we report the observation of a novel
spin resonance due to SOI that does not require external driving fields.
Ballistic spin resonance (BSR) is driven by an internal spin-orbit field that
acts upon electrons bouncing at gigaHertz frequencies in narrow channels of
ultra-clean two-dimensional electron gas (2DEG). BSR is manifested in
electrical measurements of pure spin currents as a strong suppression of spin
relaxation length when the motion of electrons is in resonance with spin
precession. These findings point the way to gate-tunable coherent spin
rotations in ballistic nanostructures without external a.c. fields.",0811.1244v1
2009-02-15,Effects of Electric Fields on Heteronuclear Feshbach Resonances in Ultracold $^6\rm{Li}-^{87}\rm{Rb}$ Mixtures,"The effects of combined external electric and magnetic fields on elastic
collisions in ultracold Li--Rb mixtures is studied using recently obtained,
experimentally verified potentials. Our analysis provides both quantitative
predictions for and a detailed physical interpretation of the phenomena arising
from electric-field-induced interactions. It is shown that the electric field
shifts the positions of intrinsic magnetic Feshbach resonances, generates
copies of resonances previously restricted to a particular partial-wave
collision to other partial wave channels, and splits Feshbach resonances into
multiple resonances for states of non-zero angular momenta. It was recently
observed that the magnetic dipole-dipole interaction can also lift the
degeneracy of a p-wave state splitting the associated p-wave Feshbach resonance
into two distinct resonances at different magnetic fields. Our work shows that
the splitting of the resonances produced by an applied electric field is more
than an order of magnitude larger. This new phenomenon offers a complementary
way to produce and tune an anisotropic interaction and to study its effect on
the many-body physics of heteronuclear atomic gases.",0902.2505v1
2009-05-08,Exotic Grazing Resonances in Nanowires,"We investigate electromagnetic scattering from nanoscale wires and reveal for
the first time, the emergence of a family of exotic resonances, or enhanced
fields, for source waves close to grazing incidence. These grazing resonances
can have a much higher Q factor, broader bandwidth, and are much less
susceptible to material losses than the well known surface plasmon resonances
found in metal nanowires. Contrary to surface plasmon resonances however, these
grazing resonances can be excited in both dielectric and metallic nanowires and
are insensitive to the polarization state of the incident wave. This peculiar
resonance effect originates from the excitation of long range guided surface
waves through the interplay of coherently scattered continuum modes coupled
with the azimuthal first order propagating mode of the cylindrical nanowire.
The nanowire resonance phenomenon revealed here can be utilized in broad
scientific areas, including: metamaterial designs, nanophotonic integration,
nanoantennas, and nanosensors.",0905.1357v1
2009-05-31,The impact of local resonance on the enhanced transmission and dispersion of surface resonances,"We investigate the enhanced microwave transmission through the array of
metallic coaxial annular apertures (MCAAs) experimentally and theoretically.
The even-mode and the odd-mode surface resonances are clarified from the
spatial field distributions and the dispersion diagram. The impact of local
resonance is thoroughly embodied in the even-mode surface resonant states,
while the odd-mode surface resonances are scaled by periodicity, invariant to
different local geometry of the unit cell, and invisible in measurements. The
enhanced transmission is the collective selections on the interplay between the
local resonances and the evanescent Bloch wave channels on the surface.
Transmission measurements for different inner diameter of the apertures show
that the transmissivity extrema with respect to the specific angles precisely
correspond to the degenerate points in the dispersion diagram of surface
resonances.",0906.0128v1
2009-06-17,Resonances and bifurcations in axisymmetric scale-free potentials,"We investigate an analytical treatment of bifurcations of families of
resonant `thin' tubes in axisymmetric galactic potentials. We verify that the
most relevant bifurcations are due to the (1:1) resonance producing the
`inclined' orbits through two different mechanisms: from the disk orbit and
from the `thin' tube associated to the vertical oscillation. The closest
resonances occurring after these are the (4:3) resonance in the oblate case and
the (2:1) resonance in the prolate case. The (1:1) resonances are treated in a
straightforward way using a 2nd-order truncated normal form. The higher-order
resonances are instead cumbersome to investigate, because the normal form has
to be truncated to a high degree and the number of terms grows very rapidly. We
therefore adopt a further simplification giving analytic formulas for the
values of the parameters at which bifurcations ensue and compare them with
selected numerical results. Thanks to the asymptotic nature of the series
involved, the predictions are reliable well beyond the convergence radius of
the original series.",0906.3138v2
2010-09-01,Compact electric-LC resonators for metamaterials,"Alternative designs to an electric-LC (ELC) resonator, which is a type of
metamaterial inclusion, are presented in this article. Fitting the resonator
with an interdigital capacitor (IDC) helps to increase the total capacitance of
the structure. In effect, its resonance frequency is shifted downwards. This
implies a decreased overall resonator size with respect to its operating
wavelength. As a result, the metamaterial, composed of an array of IDC-loaded
ELC resonators with their collective electromagnetic response, possesses
improved homogeneity and hence is less influenced by diffraction effects of
individual cells. The impact of incorporating an IDC into ELC resonators in
terms of the electrical size at resonance and other relevant properties are
investigated through both simulation and experiment.",1009.0139v1
2010-09-08,Tuning the Resonance in High Temperature Superconducting Terahertz Metamaterials,"In this Letter we present resonance properties in terahertz metamaterials
consisting of a split-ring resonator array made from high temperature
superconducting films. By varying the temperature, we observed efficient
metamaterial resonance switching and frequency tuning with some features not
revealed before. The results were well reproduced by numerical simulations of
metamaterial resonance using the experimentally measured complex conductivity
of the superconducting film. We developed a theoretical model that explains the
tuning features, which takes into account the resistive resonance damping and
additional split-ring inductance contributed from both the real and imaginary
parts of the temperature-dependent complex conductivity. The theoretical model
further predicted more efficient resonance switching and frequency shifting in
metamaterials consisting of a thinner superconducting split-ring resonator
array, which were also verified in experiments.",1009.1640v1
2010-11-05,"Effects of Turbulence, Eccentricity Damping, and Migration Rate on the Capture of Planets into Mean Motion Resonance","Pairs of migrating extrasolar planets often lock into mean motion resonance
as they drift inward. This paper studies the convergent migration of giant
planets (driven by a circumstellar disk) and determines the probability that
they are captured into mean motion resonance. The probability that such planets
enter resonance depends on the type of resonance, the migration rate, the
eccentricity damping rate, and the amplitude of the turbulent fluctuations.
This problem is studied both through direct integrations of the full 3-body
problem, and via semi-analytic model equations. In general, the probability of
resonance decreases with increasing migration rate, and with increasing levels
of turbulence, but increases with eccentricity damping. Previous work has shown
that the distributions of orbital elements (eccentricity and semimajor axis)
for observed extrasolar planets can be reproduced by migration models with
multiple planets. However, these results depend on resonance locking, and this
study shows that entry into -- and maintenance of -- mean motion resonance
depends sensitively on migration rate, eccentricity damping, and turbulence.",1011.1486v1
2010-12-10,Quantum pumping in graphene nanoribbons at resonant transmission,"Adiabatic quantum charge pumping in graphene nanoribbon double barrier
structures with armchair and zigzag edges in the resonant transmission regime
is analyzed. Using recursive Green's function method we numerically calculate
the pumped charge for pumping contours encircling a resonance. We find that for
armchair ribbons the whole resonance line contributes to the pumping of a
single electron (ignoring double spin degeneracy) per cycle through the device.
The case of zigzag ribbons is more interesting due to zero-conductance
resonances. These resonances separate the whole resonance line into several
parts, each of which corresponds to the pumping of a single electron through
the device. Moreover, in contrast to armchair ribbons, one electron can be
pumped from the left lead to the right one or backwards. The current direction
depends on the particular part of the resonance line encircled by the pumping
contour.",1012.2221v1
2011-03-11,Observation and characterization of mode splitting in microsphere resonators in aquatic environment,"Whispering gallery mode (WGM) optical resonators utilizing resonance shift
(RS) and mode splitting (MS) techniques have emerged as highly sensitive
platforms for label-free detection of nano-scale objects. RS method has been
demonstrated in various resonators in air and liquid. MS in microsphere
resonators has not been achieved in aqueous environment up to date, despite its
demonstration in microtoroid resonators. Here, we demonstrate scatterer-induced
MS of WGMs in microsphere resonators in water. We determine the size range of
particles that induces MS in a microsphere in water as a function of resonator
mode volume and quality factor. The results are confirmed by the experimental
observations.",1103.2398v1
2011-05-05,Fano effect and nonuniversal phase lapses in mesoscopic regime of transport,"The transmission probability and phase through a few-electron quantum dot are
studied within a resonance theory for the strong coupling regime to the
conducting leads. We find that the interaction between overlapping resonances
leads to their separation in the complex energy plane and to the decoherent
dephasing of the resonant modes. The appearance of the Fano effect is
conditioned not only by the induced dephasing generally associated with a phase
lapse, but also by a favorable parity of the resonant modes. To identify the
contribution of each resonance to the transmission, we propose, in the case of
overlapping resonances, a decomposition of the scattering matrix in resonant
terms and a background. The resonant contributions are approximated by Fano
lines with complex asymmetry parameters and the background by a constant. The
conductance and the transmission phase calculated within this approach
reproduce the generic features of the experimental data.",1105.1167v1
2011-06-17,Sequential vibrational resonance in multistable systems,"The phenomenon of sequential vibrational resonance existed in a multistable
system that is excited by both high- and low-frequency signals is reported. By
the method of direct separation of motions, the theoretical investigation on
vibrational resonance is conducted in both cases of underdamped and overdamped,
and the analytical predictions are in good agreement with the numerical
simulations. In view of the theoretical results, the zero-order Bessel function
related to the high-frequency signal is included in the renormalized resonant
frequency, and which leads to the appearance of the sequential vibrational
resonance. In the case of underdamped system with small damping coefficient,
the resonance occurs in a series of discrete parameter regions. The sequential
vibrational resonance is different from the traditional multiple vibrational
resonance, because its appearance is much more regular. The results in this
work may be helpful in the field of signal processing electronics, especially
for dealing with the very-low-frequency signal.",1106.3431v1
2011-10-12,Giant red shift and enhancement of resonant light confinement in planar array of dielectric bars,"Results of research of resonant phenomena in planar periodic structures
consisted of dielectric elements are presented. A problem of plane wave
diffraction by a structure which a periodic cell is composed of two dielectric
bars with different lengths has been solved. For the first time an existence of
high Q-factor trapped mode resonances are revealed in these structures. The
main difference of studied structure in contrast to the planar structure with a
single dielectric bar in the unit cell is appearing of a great red shift of a
trapped mode resonant wavelength. The red shift is caused by strong coupling of
electromagnetic fields in neighbor dielectric bar resonators. This property is
very attractive to design resonant periodic planar structures by using moderate
refractive index materials like semiconductors within their transparency
window. In the near infrared band, the trapped mode resonances of periodic
planar structure with bars made of germanium have been studied. It is shown
that decreasing of structure asymmetry degree results in increasing of both red
shift and Q-factor of resonance.",1110.2699v2
2012-02-27,Magnetic hysteresis effects in superconducting coplanar microwave resonators,"We performed transmission spectroscopy experiments on coplanar half
wavelength niobium resonators at a temperature T=4.2 K. We observe not only a
strong dependence of the quality factor Q and the resonance frequency f_res on
an externally applied magnetic field but also on the magnetic history of our
resonators, i.e. on the spatial distribution of trapped Abrikosov vortices in
the device. We find these results to be valid for a broad range of frequencies
and angles between the resonator plane and the magnetic field direction as well
as for resonators with and without antidots near the edges of the center
conductor and the ground planes. In a detailed analysis we show, that
characteristic features of the experimental data can only be reproduced in
calculations, if a highly inhomogeneous rf-current density and a flux density
gradient with maxima at the edges of the superconductor is assumed. We
furthermore demonstrate, that the hysteretic behaviour of the resonator
properties can be used to considerably reduce the vortex induced losses and to
fine-tune the resonance frequency by the proper way of cycling to a desired
magnetic field.",1202.5963v1
2012-07-01,Observation of two new $N^*$ resonances in $ψ(3686) \rightarrow p\bar{p}π^0$,"Based on 106$\times10^6 \psi(3686)$ events collected with the BESIII detector
at the BEPCII facility, a partial wave analysis of $\psi(3686)\rightarrow
p\bar{p}\pi^0$ is performed. The branching fraction of this channel has been
determined to be $B(\psi(3686)\rightarrow p\bar{p}\pi^0) =
(1.65\pm0.03\pm0.15)\times 10^{-4}$. In this decay, 7 $N^*$ intermediate
resonances are observed. Among these $N^*$ resonances, two new resonances are
significant, one $1/2^+$ resonance with a mass of
$2300^{+40}_{-30}$$^{+109}_{-0}$ $\mathrm{MeV}/c^2$ and width of
$340^{+30}_{-30}$$^{+110}_{-58}$ $\mathrm{MeV}/c^2$, and one $5/2^-$ resonance
with a mass of $2570^{+19}_{-10}$$^{+34}_{-10}$ $\mathrm{MeV}/c^2$ and width of
$250^{+14}_{-24}$$^{+69}_{-21}$ $\mathrm{MeV}/c^2$. For the remaining 5 $N^*$
intermediate resonances, the analysis yields mass and width values which are
consistent with those from established resonances.",1207.0223v2
2012-07-04,Quantum dot admittance probed at microwave frequencies with an on-chip resonator,"We present microwave frequency measurements of the dynamic admittance of a
quantum dot tunnel coupled to a two-dimensional electron gas. The measurements
are made via a high-quality 6.75 GHz on-chip resonator capacitively coupled to
the dot. The resonator frequency is found to shift both down and up close to
conductance resonance of the dot corresponding to a change of sign of the
reactance of the system from capacitive to inductive. The observations are
consistent with a scattering matrix model. The sign of the reactance depends on
the detuning of the dot from conductance resonance and on the magnitude of the
tunnel rate to the lead with respect to the resonator frequency. Inductive
response is observed on a conductance resonance, when tunnel coupling and
temperature are sufficiently small compared to the resonator frequency.",1207.0945v2
2012-09-06,Magnetic Feshbach resonances in collisions of non-magnetic closed-shell $^1Σ$ molecules,"Magnetic Feshbach resonances play a central role in experimental research of
atomic gases at ultracold temperatures, as they allow one to control the
microscopic interactions between ultracold atoms by tuning an applied magnetic
field. These resonances arise due to strong hyperfine interactions between the
unpaired electron and the nuclear magnetic moment of the alkali metal atoms. A
major thrust of current research is to create an ultracold gas of diatomic
alkali-metal molecules in the ground rovibrational state of the ground
electronic $^1\Sigma$ state. Unlike alkali metal atoms, $^1\Sigma$ diatomic
molecules have no unpaired electrons. However, the hyperfine interactions of
molecules may give rise to magnetic Feshbach resonances. We use quantum
scattering calculations to study the possible width of these resonances. Our
results show that the widths of magnetic Feshbach resonances in ultracold
molecule-molecule collisions for $^1\Sigma$ molecules may exceed 1 milliGauss,
rendering such resonances experimentally detectable. We hope that this work
will stimulate the experimental search of these resonances.",1209.1418v2
2012-12-18,Resonance states in a cylindrical quantum dot with an external magnetic field,"Bound and resonance states of quantum dots play a significant role in
photo-absorption processes. In this work, we analyze a cylindrical quantum dot,
its spectrum and, in particular, the behaviour of the lowest resonance state
when a magnetic field is applied along the symmetry axis of the cylinder. To
obtain the energy and width of the resonance we use the complex rotation
method. As it is expected the structure of the spectrum is strongly influenced
by the Landau levels associated to the magnetic field. We show how this
structure affects the behaviour of the resonance state and that the binding of
the resonance has a clear interpretation in terms of the Landau levels and the
probability of localization of the resonance state. The localization
probability and the fidelity of the lowest energy state allows to identify two
different physical regimes, a large field-small quantum dot radius regime and a
small field-large quantum dot radius, where the binding of the resonance is
dominated by the field strength or the potential well, respectively.",1212.4323v2
2013-02-24,Electron spin resonance in a dilute magnon gas as a probe of magnon scattering resonances,"We study the electron spin resonance in a dilute magnon gas that is realized
in a ferromagnetic spin system at low temperature. A quantum cluster expansion
is developed to show that the frequency shift of the single-magnon peak changes
its sign and the linewidth reaches its maximum across a scattering resonance
between magnons. Such characteristic behaviors are universal and can be used to
experimentally locate the two-magnon resonance when an external parameter such
as pressure is varied. Future achievement of the two-magnon resonance may have
an impact comparable to the Feshbach resonance in ultracold atoms and will open
up a rich variety of strongly correlated physics such as the recently proposed
Efimov effect in quantum magnets. We also suggest how the emergence of an
Efimov state of three magnons and its binding energy may be observed with the
electron spin resonance.",1302.5908v2
2013-03-01,Unconventional Fano effect and off-resonance field enhancement in plasmonic coated spheres,"We investigate light scattering by coated spheres composed of a dispersive
plasmonic core and a dielectric shell. By writing the absorption cross-section
in terms of the internal electromagnetic fields, we demonstrate it is an
observable sensitive to interferences that ultimately lead to the Fano effect.
Specially, we show that unconventional Fano resonances, recently discovered for
homogeneous spheres with large dielectric permittivities, can also occur for
metallic spheres coated with single dielectric layers. These resonances arise
from the interference between two electromagnetic modes with the same multipole
moment inside the shell and not from interactions between various plasmon modes
of different layers of the particle. In contrast to the case of homogeneous
spheres, unconventional Fano resonances in coated spheres exist even in the
Rayleigh limit. These resonances can induce an off-resonance field enhancement,
which is approximately one order of magnitude larger than the one achieved with
conventional Fano resonances. We find that unconventional and conventional Fano
resonances can occur at the same input frequency provided the dispersive core
has a negative refraction index. This leads to an optimal field enhancement
inside the particle, a result that could be useful for potential applications
in plasmonics.",1303.0185v1
2013-04-01,Fano resonances and their control in optomechanics,"The Fano line profiles, originally discovered in the context of
photoionization, have been found to occur in a large class of systems like
resonators, metamaterials, plasmonics. We demonstrate the existence of such
resonances in cavity optomechanics by identifying the interfering contributions
to the fields generated at antiStokes and Stokes frequencies. Unlike the atomic
systems, the optomechanical systems provide great flexibility as the width of
the resonance is controlled by the coupling field. We further show how the
double cavities coupled by a single optomechanical mirror can lead to the
splitting of the Fano resonance and how the second cavity can be used to tune
the Fano resonances. The Fano resonances are quite sensitive to the decay
parameters associated with cavities and the mechanical mirror. Such resonances
can be studied by both pump probe experiments as well as via the spectrum of
the quantum fluctuations in the output fields.",1304.0389v2
2013-04-11,Experimental demonstrations of high-Q superconducting coplanar waveguide resonators,"We designed and successfully fabricated an absorption-type of superconducting
coplanar waveguide (CPW) resonators. The resonators are made from a Niobium
film (about 160 nm thick) on a high-resistance Si substrate, and each resonator
is fabricated as a meandered quarter-wavelength transmission line (one end
shorts to the ground and another end is capacitively coupled to a through
feedline). With a vector network analyzer we measured the transmissions of the
applied microwave through the resonators at ultra-low temperature (e.g., at 20
mK), and found that their loaded quality factors are significantly high, i.e.,
up to 10^6. With the temperature increases slowly from the base temperature
(i.e., 20 mK), we observed the resonance frequencies of the resonators are blue
shifted and the quality factors are lowered slightly. In principle, this type
of CPW-device can integrate a series of resonators with a common feedline,
making it a promising candidate of either the data bus for coupling the distant
solid-state qubits or the sensitive detector of single photons.",1304.3254v1
2013-04-15,Vibrational resonance in groundwater-dependent plant ecosystems,"We report the phenomenon of vibrational resonance in a single species and a
two species models of groundwater-dependent plant ecosystems with a biharmonic
oscillation (with two widely different frequencies \omega and \Omega, \Omega >>
\omega) of the water table depth. In these two systems, the response amplitude
of the species biomass shows multiple resonances with different mechanisms. The
resonance occurs at both low- and high-frequencies of the biharmonic force. In
the single species bistable system, the resonance occurs at discrete values of
the amplitude g of the high-frequency component of the water table.
Furthermore, the best synchronization of biomass and its carrying capacity with
the biharmonic force occurs at the resonance. In the two species excitable and
time-delay model, the response amplitude (Q) profile shows several plateau
regions of resonance, where the period of evolution of the species biomass
remains the same and the value of Q is inversely proportional to it. The
response amplitude is highly sensitive to the time-delay parameter \tau and
shows two distinct sequences of resonance intervals with a decreasing amplitude
with \tau.",1304.4170v1
2013-05-02,Finite element simulation of a perturbed axial-symmetric whispering-gallery mode and its use for intensity enhancement with a nanoparticle coupled to a microtoroid,"We present an optical mode solver for a whispering gallery resonator coupled
to an adjacent arbitrary shaped nano-particle that breaks the axial symmetry of
the resonator. Such a hybrid resonator-nanoparticle is similar to what was
recently used for bio-detection and for field enhancement. We demonstrate our
solver by parametrically studying a toroid-nanoplasmonic device and get the
optimal nano-plasmonic size for maximal enhancement. We investigate cases near
a plasmonic resonance as well as far from a plasmonic resonance. Unlike common
plasmons that typically benefit from working near their resonance, here working
far from plasmonic resonance provides comparable performance. This is because
the plasmonic resonance enhancement is accompanied by cavity quality
degradation through plasmonic absorption.",1305.0555v1
2013-11-05,Effect of magnetic field on resonant tunneling in 3D waveguides of variable cross-section,"We consider an infinite three-dimensional waveguide that far from the
coordinate origin coincides with a cylinder. The waveguide has two narrows of
diameter $\varepsilon$. The narrows play the role of effective potential
barriers for the longitudinal electron motion. The part of waveguide between
the narrows becomes a ""resonator""\, and there can arise conditions for electron
resonant tunneling. A magnetic field in the resonator can change the basic
characteristics of this phenomenon. In the presence of a magnetic field, the
tunneling phenomenon is feasible for producing spin-polarized electron flows
consisting of electrons with spins of the same direction.
  We assume that the whole domain occupied by a magnetic field is in the
resonator. An electron wave function satisfies the Pauli equation in the
waveguide and vanishes at its boundary. Taking $\varepsilon$ as a small
parameter, we derive asymptotics for the probability $T(E)$ of an electron with
energy $E$ to pass through the resonator, for the ""resonant energy""\,$E_{res}$,
where $T(E)$ takes its maximal value, and for some other resonant tunneling
characteristics.",1311.1126v1
2013-11-20,Formation and interaction of resonance chains in the open 3-disk system,"In ballistic open quantum systems one often observes that the resonances in
the complex-energy plane form a clear chain structure. Taking the open 3-disk
system as a paradigmatic model system, we investigate how this chain structure
is reflected in the resonance states and how it is connected to the underlying
classical dynamics. Using an efficient scattering approach we observe that
resonance states along one chain are clearly correlated while resonance states
of different chains show an anticorrelation. Studying the phase space
representations of the resonance states we find that their localization in
phase space oscillate between different regions of the classical trapped set as
one moves along the chains and that these oscillations are connected to a
modulation of the resonance spacing. A single resonance chain is thus no WKB
quantization of a single periodic orbits, but the structure of several
oscillating chains arises from the interaction of several periodic orbits. We
illuminate the physical mechanism behind these findings by combining the
semiclassical cycle expansion with a quantum graph model.",1311.5128v2
2014-04-03,Theoretical study of a $d^{*}$ resonance in $^{3}G_{3}$ partial wave of nucleon-nucleon scattering,"Inspired by the recent results of the WASA-at-COSY Collaboration, in which
they found a resonance pole in the coupled $^{3}D_{3}$ - $^{3}G_{3}$ partial
waves as expected from the $d^{*}$ resonance hypothesis, we calculated the
resonance structure in the coupled $^{3}D_{3}$ - $^{3}G_{3}$ partial wave phase
shifts of nucleon-nucleon scattering in the framework of two constituent quark
models: the quark delocalization color screening model and the chiral quark
model. Our results show that there is a resonance $^{7}S_{3}^{\Delta\Delta}$ in
the coupled $^{3}D_{3}^{NN}$ and $^{3}G_{3}^{NN}$ partial waves in both of
these two models, which is in accordance with the expectation from the $d^{*}$
resonance structure. The resonance shape in the $^{3}D_{3}^{NN}$ partial wave
is remarkable, whereas in the $^{3}G_{3}^{NN}$ phase shifts there is a small
rise around the resonance energy. This result is in agreement with the recent
experimental observations of WASA-at-COSY Collaboration.",1404.0947v2
2014-07-07,Dielectric Square Resonator Investigated with Microwave Experiments,"We present a detailed experimental study of the symmetry properties and the
momentum space representation of the field distributions of a dielectric square
resonator as well as the comparison with a semiclassical model. The experiments
have been performed with a flat ceramic microwave resonator. Both the resonance
spectra and the field distributions were measured. The momentum space
representations of the latter evidenced that the resonant states are each
related to a specific classical torus, leading to the regular structure of the
spectrum. Furthermore, they allow for a precise determination of the refractive
index. Measurements with different arrangements of the emitting and the
receiving antennas were performed and their influence on the symmetry
properties of the field distributions was investigated in detail, showing that
resonances with specific symmetries can be selected purposefully. In addition,
the length spectrum deduced from the measured resonance spectra and the trace
formula for the dielectric square resonator are discussed in the framework of
the semiclassical model.",1407.1802v2
2014-07-10,Ultrafast Switching in Terahertz Metamaterials using Ion Implanted Silicon on Sapphire,"We demonstrate ultrafast resonance switching of terahertz metamaterials
through optical excitation of radiation damaged silicon placed in the gap of
single split gap ring resonator. We observe the dynamic switching OFF of the
fundamental resonance mode on a time scale of 4 picoseconds (ps) followed by
the switching ON of the same resonance after 20 ps. Electric field
distributions in the metamaterials unit cell derived through numerical
simulations clearly support our experimental observations, showing that the
high electric field at the resonator gaps, responsible for inductive-capacitive
resonance (LC), completely disappears and switches OFF the resonance after
being optically excited. The ultrafast switching of the metamaterial resonance
is attributed to the generation of free carriers in ion-implanted silicon and
their recombination at an ultra-short time scale. Such silicon based active
control of metamaterials can lead to the ultrafast terahertz metadevices.",1407.2715v1
2014-08-06,On the dynamics of space debris: 1:1 and 2:1 resonances,"We study the dynamics of the space debris in the 1:1 and 2:1 resonances,
where geosynchronous and GPS satellites are located. By using Hamiltonian
formalism, we consider a model including the geopotential contribution for
which we compute the secular and resonant expansions of the Hamiltonian.
  Within such model we are able to detect the equilibria and to study the main
features of the resonances in a very effective way. In particular, we analyze
the regular and chaotic behavior of the 1:1 and 2:1 resonant regions by
analytical methods and by computing the Fast Lyapunov Indicators, which provide
a cartography of the resonances. This approach allows us to detect easily the
location of the equilibria, the amplitudes of the libration islands and the
main dynamical stability features of the resonances, thus providing an overview
of the 1:1 and 2:1 resonant domains under the effect of Earth's oblateness.
  The results are validated by a comparison with a model developed in Cartesian
coordinates, including the geopotential, the gravitational attraction of Sun
and Moon and the solar radiation pressure.",1408.1254v1
2014-08-07,Ferromagnetic resonance of a magnetic dimer with dipolar coupling,"We develop a general formalism for analyzing the ferromagnetic resonance
characteristics of a magnetic dimer consisting of two magnetic elements (in a
horizontal or vertical configuration) coupled by dipolar interaction, taking
account of their finite-size and aspect ratio. We study the effect on the
resonance frequency and resonance field of the applied magnetic field (in
amplitude and direction), the inter-element coupling, and the uniaxial
anisotropy in various configurations. We obtain analytical expressions for the
resonance frequency in various regimes of the interlayer coupling. We
(numerically) investigate the behavior of the resonance field in the
corresponding regimes. The critical value of the applied magnetic field at
which the resonance frequency vanishes may be an increasing or a decreasing
function of the dimer's coupling, depending on the anisotropy configuration. It
is also a function of the nanomagnets aspect ratio in the case of in-plane
anisotropy. This and several other results of this work, when compared with
experiments using the standard ferromagnetic resonance with fixed frequency, or
the network analyzer with varying frequency and applied magnetic field, provide
a useful means for characterizing the effective anisotropy and coupling within
systems of stacked or assembled nanomagnets.",1408.1594v1
2014-08-10,Fast universal quantum gates on microwave photons with all-resonance operations in circuit QED,"Stark shift on a superconducting qubit in circuit quantum electrodynamics
(QED) has been used to construct universal quantum entangling gates on
superconducting resonators in previous works. It is a second-order coupling
effect between the resonator and the qubit in the dispersive regime, which
leads to a slow state-selective rotation on the qubit. Here, we present two
proposals to construct the fast universal quantum gates on superconducting
resonators in a microwave-photon quantum processor composed of multiple
superconducting resonators coupled to a superconducting transmon qutrit, that
is, the controlled-phase (c-phase) gate on two microwave-photon resonators and
the controlled-controlled phase (cc-phase) gates on three resonators, resorting
to quantum resonance operations, without any drive field. Compared with
previous works, our universal quantum gates have the higher fidelities and
shorter operation times in theory. The numerical simulation shows that the
fidelity of our c-phase gate is 99.57% within about 38.1 ns and that of our
cc-phase gate is 99.25% within about 73.3 ns.",1408.2168v2
2014-10-24,Bound and resonance states of the dipolar anion of hydrogen cyanide: competition between threshold effects and rotation in an open quantum system,"Bound and resonance states of the dipole-bound anion of hydrogen cyanide
HCN$^-$ are studied using a non-adiabatic pseudopotential method and the
Berggren expansion technique involving bound states, decaying resonant states,
and non-resonant scattering continuum. We devise an algorithm to identify the
resonant states in the complex energy plane. To characterize spatial
distributions of electronic wave functions, we introduce the body-fixed density
and use it to assign families of resonant states into collective rotational
bands. We find that the non-adiabatic coupling of electronic motion to
molecular rotation results in a transition from the strong-coupling to
weak-coupling regime. In the strong coupling limit, the electron moving in a
subthreshold, spatially extended halo state follows the rotational motion of
the molecule. Above the ionization threshold, electron's motion in a resonance
state becomes largely decoupled from molecular rotation. Widths of
resonance-band members depend primarily on the electron orbital angular
momentum.",1410.6660v1
2014-11-06,The nucleon resonances in the $J/ψ\to p\bar{p}η'$ decay,"We are aiming to study the $J/\psi \to p\bar{p}\eta'$ decay in an isobar
model and the effective Lagrangian approach. After a careful exploration of the
contributions of the $S_{11}(1535)$, $P_{11}(1710)$, $P_{13}(1900)$,
$S_{11}(2090)$ and $P_{11}(2100)$ resonances, we conclude that either a
subthreshold resonance or a broad $P$-wave state in the near threshold range
seems to be indispensable to describe present data of the $\pi N \to \eta'N$.
Furthermore, at least one broad resonance above $\eta'N$ threshold is
preferred. With this detailed analysis, we could give the invariant mass
spectrum and Dalitz plot of the $J/\psi \to p\bar{p}\eta'$ decay for the
purpose of assisting the future detailed partial wave analysis. It is found
that the $J/\psi \to p\bar{p}\eta'$ data are useful for disentangling the above
or below threshold resonant contribution, though it still further needs the
differential cross section data of $\pi N \to \eta'N$ to realize some of the
resonant and the non-resonant contribution. Our results are enlightening for
the $\eta'N$ production mechanism and the properties of the nucleon resonances
with the mass around 2.0~GeV.",1411.1493v1
2014-12-03,On bifurcations in degenerate resonance zones,"For Hamitonian systems with 3/2 degrees of freedom close to nonlinear
integrable and for symplectic maps of the cylinder, bifurcations in degenerate
resonance zones are discussed.",1412.1252v1
2014-12-18,Superconductive Ultra-compact Magnetically Coupled Resonator with Twin-spiral Structure,"We describe a practical design of an ultra-compact on-chip superconductive
micro-resonator as a potential magnetic element of metamaterial. The achieved
resonator size with respect to the wavelength in our experiment is about
{\lambda}/ 14400. The resonator consists of two superconducting Nb spirals,
sandwiched face to face, with a small gap filled with dielectric. The spirals
are turning in opposite directions: one clockwise, another counter-clockwise.
We study the resonator spectral response and its inner modes using numerical
simulation in HFSS. In experiment with a Laser Scanning Microscope (LSM) we
confirm the predictions for the resonance frequencies of Nb superconductive
resonator and its inner modes structures. Small size and the ease of
manufacturing make the two-spiral resonator an attractive solution for
superconductive filters, coupling circuits, and as a magnetic component of a
metamaterial.",1412.5750v2
2015-01-30,Dynamically tunable Fano resonance in periodically asymmetric graphene nanodisk pair,"We present a dynamically frequency tunable Fano resonance planar device
composed of periodically asymmetric graphene nanodisk pair for the mid-infrared
region. There are two kinds of modes in this structure, that is, the symmetric
mode and the antisymmetric mode. The resonance coupling between the symmetric
and antisymmetric modes creates a classical Fano resonance. Both of the Fano
resonance amplitude and frequency of the structure can be dynamically
controlled by varying the Fermi energy of graphene. Resonance transition in the
structure is studied to reveal the physical mechanism behind the dynamically
tunable Fano resonance. The features of the Fano resonant graphene
nanostructures should have promising applications in tunable THz filters,
switches, and modulators.",1501.07744v1
2015-08-24,Broadband architecture for galvanically accessible superconducting microwave resonators,"In many hybrid quantum systems, a superconducting circuit is required that
combines DC-control with a coplanar waveguide (CPW) microwave resonator. The
strategy thus far for applying a DC voltage or current bias to microwave
resonators has been to apply the bias through a symmetry point in such a way
that it appears as an open circuit for certain frequencies. Here, we introduce
a microwave coupler for superconducting CPW cavities in the form of a large
shunt capacitance to ground. Such a coupler acts as a broadband mirror for
microwaves while providing galvanic connection to the center conductor of the
resonator. We demonstrate this approach with a two-port
$\lambda/4$-transmission resonator with linewidths in the MHz regime
($Q\sim10^3$) that shows no spurious resonances and apply a voltage bias up to
$80$ V without affecting the quality factor of the resonator. This resonator
coupling architecture, which is simple to engineer, fabricate and analyse,
could have many potential applications in experiments involving superconducting
hybrid circuits.",1508.05770v2
2015-09-18,Theory of inelastic confinement-induced resonances due to the coupling of center-of-mass and relative motion,"A detailed study of the anharmonicity-induced resonances caused by the
coupling of center-of-mass and relative motion is presented for a system of two
ultracold atoms in single-well potentials. As has been confirmed
experimentally, these inelastic confinement-induced resonances are of interest,
since they can lead to coherent molecule formation, losses, and heating in
ultracold atomic gases. A perturbative model is introduced to describe the
resonance positions and the coupling strengths. The validity of the model and
the behavior of the resonances for different confinement geometries are
analyzed in comparison with exact numerical ab initio calculations. While such
resonances have so far only been detected for large positive values of the
$s$-wave scattering length, it is found that they are present also for negative
$s$-wave scattering lengths, i. e. for attractive interactions. The possibility
to coherently tune the resonances by a variation of the external confinement
geometry might pave the way for coherent molecule association where magnetic
Feshbach resonances are inaccessible.",1509.05799v1
2015-09-29,Second harmonic generation with plasmonic metasurfaces: direct comparison of electric and magnetic resonances,"Plasmonic resonances in metallic nanostructures have been shown to
drastically enhance local electromagnetic fields, and thereby increase the
efficiency of nonlinear optical phenomena, such as second harmonic generation
(SHG). While it has been experimentally observed that enhanced fields can
significantly boost SHG, to date it proved difficult to probe electrical and
magnetic resonances in one and the same nanostructure. This however is
necessary to directly compare relative contributions of electrical and magnetic
components of SHG enhancement. In this paper we report an experimental study of
a metasurface capable of providing electrical and magnetic resonant SHG
enhancement for TM polarization. Our metasurface could be engineered such that
the peak frequencies of electrical and magnetic resonances could be adjusted
independently. We used this feature to distinguish their relative
contributions. Experimentally it was observed that the magnetic resonance
provides only 50% as much enhancement to SHG as compared to the electric
resonance. In addition aligning both resonances in frequency results in
conversion efficiency of 1.32 x 10^(-10).",1509.08871v1
2015-10-19,Quasi-forbidden 2-body Förster resonances in cold Cs Rydberg gas,"Cold Rydberg atoms are known to display dipole-dipole interaction allowed
resonances, also called F\""orster resonances, which lead to an efficient energy
transfer when the proper electric field is used. This electric field also
enables resonances which do not respect the dipole-dipole selection rules under
zero field. A few of these quasi-forbidden resonances have been observed but
they are often overlooked. Here we show that in cold $^{133}$Cs atoms there is
a large number of these resonances that display a significant transfer
efficiency due to their strong interactions, even at low electric field. We
also develop a graphical method enabling to find all possible resonances
simultaneously. The resulting dramatic increase in the total number of
addressable resonant energy transfers at different electric fields could have
implications in the search for few-body interactions or macro-molecules built
from Rydberg atoms.",1510.05350v2
2016-03-05,Controlling the Characteristics of Nanomechanical Resonators,"The dynamics of nanomechanical resonators driven by both low- and
high-frequency signals is studied. Considering, as an example, resonators made
of a doubly-clamped beam with magnetomotive driving, it is shown that
three-frequency resonances arise due to the interaction of the above
frequencies. Properties and characteristics of these resonances are determined
analytically for linear and nonlinear modes of the resonator excitation. It is
shown that in opposite to the conventional two-frequency resonance, the central
frequency of these resonances, their linear dynamic range, and the critical
value for the bistability onset are easily controlled by changing the frequency
and the amplitude of the low-frequency driving current. The obtained results
can be used when developing NMRs for sensors, filters, memory elements, and
other applications.",1603.01732v1
2016-03-23,Dynamics and Transit Variations of Resonant Exoplanets,"The Transit Timing Variations (TTVs) are deviations of the measured
mid-transit times from the exact periodicity. One of the most interesting
causes of TTVs is the gravitational interaction between planets. Here we
consider a case of two planets in a mean motion resonance (orbital periods in a
ratio of small integers). This case is important because the resonant
interaction can amplify the TTV effect and allow planets to be detected more
easily. We develop an analytic model of the resonant dynamics valid for small
orbital eccentricities and use it to derive the principal TTV terms. We find
that a resonant system should show TTV terms with two basic periods (and their
harmonics). The resonant TTV period is proportional (m/M_*)^(-2/3), where m and
M_* are the planetary and stellar masses. For m=10^(-4) M_*, for example, the
TTV period exceeds the orbital period by ~2 orders of magnitude. The amplitude
of the resonant TTV terms scales linearly with the libration amplitude. The
ratio of the TTV amplitudes of two resonant planets is inversely proportional
to the ratio of their masses. These and other relationships discussed in the
main text can be used to aid the interpretation of TTV observations.",1603.07306v1
2016-09-12,Mathematical Study of Scattering Resonances,"We provide an introduction to mathematical theory of scattering resonances
and survey some recent results.",1609.03550v3
2017-03-04,On the Pollicott-Ruelle resonances,"The purpose of this survey is to present the recent advances about the
Pollicott-Ruelle resonances.",1703.01522v1
2017-08-10,Acoustic resonance in periodically sheared glass,"Using molecular dynamics simulation, we study acoustic resonance in
low-temperature glass by applying a small periodic shear at a boundary wall.
Shear wave resonance occurs as the frequency $\omega$ approaches $\omega_\ell=
\pi c_\perp\ell/L$ ($\ell=1, 2, 3,...)$. Here, $c_\perp$ is the transverse
sound speed and $L$ is the cell length. At resonance, large-amplitude sound
waves appear after many cycles even for very small applied strains. They then
induce plastic events, which are heterogeneous in space and intermittent on
time scales longer than the oscillation period $2\pi/\omega$. From these
irreversible particle motions, there arises strong dissipation suppressing the
growth of sounds. After many resonant cycles, we observe a phenomenon of forced
aging, where the shear modulus (measured after switching off the oscillation)
is increased significantly.Sometimes, exceptionally large plastic events and
system-size sliding motions induce a transition from resonant to off-resonant
states. At resonance, translational diffusion becomes appreciable as well as
aging due to enhanced configurational changes.",1708.03166v2
2017-08-15,Comment on arXiv:1612.01502 'Is the Trineutron Resonance Lower in Energy than a Tetraneutron Resonance ?',"Comment on the article by S. Gandolfi et al. Phys.Rev.Letters 118 (2017),
232501; arXiv:1612.01502 [nucl-th]",1708.04459v1
2017-08-15,The Dielectric Wakefield Resonator Accelerator,"We report preliminary studies of a three-channel, rectangular, high gradient
dielectric wakefield accelerator element, which, unlike the collinear
cylindrical dielectric wakefield device, does not suffer from low transformer
ratio and may offer relief from the beam breakup instability. When configured
as a resonator (DWR), it can be driven by a series of modest-charge drive
bunches. This rectangular 'mode-locked' resonator consists of three channels
lined with low-loss dielectric slabs: the central wider channel is the drive
bunch channel, whereas two adjacent narrow channels are used to accelerate
electron and/or positron bunches; this provides a favorable transformer ratio.
At the moment when, after reflecting from the resonator exit, the wakefield
returns to the resonator entrance, the next bunch is injected into the
resonator entrance. The length of the resonator is also chosen to be a multiple
of half the desired wakefield wavelength. The rectangular geometry permits
superposition of harmonics of wakefields in the resonator. The short length of
the device and its planar configuration should allow management of beam
breakup, and a lengthy drive bunch train can be dynamically stabilized by using
a series of DWR units rotated about the $z$-axis in $90^{\circ}$ increments.",1708.04599v1
2018-11-05,Design and characterization of a novel toroidal split-ring resonator,"The design and characterization of a novel toroidal split-ring resonator
(SRR) is described in detail. In conventional cylindrical SRRs, there is a
large magnetic flux within the bore of the resonator. However, there also
exists a non-negligible magnetic flux in the free space surrounding the
resonator. The energy losses associated with this radiated power diminish the
resonator's quality factor. In the toroidal SRR, on the other hand, the
magnetic field lines are strongly confined within the bore of the resonator
resulting in high intrinsic quality factors and stable resonance frequencies
without requiring additional electromagnetic shielding. This paper describes
the design and construction of a toroidal SRR as well as an experimental
investigation of its cw response in the frequency-domain and its time-domain
response to an rf pulse. Additionally, the dependence of the toroidal SRR's
resonant frequency and quality factor on the strength of inductive coupling to
external circuits is investigated both theoretically and experimentally.",1811.02630v1
2019-05-19,Effects of the Coulomb interaction on parameters of resonance states in mirror three-cluster nuclei,"We investigate how the Coulomb interaction affects the energy $E$ and width
$\Gamma$ of resonance states in mirror nuclei. We employ a three-cluster
microscopic model to determine position of resonance states in two- and
three-body continua. Two parameters are introduced to quantify effects of the
Coulomb interactions. As the energy and width of the corresponding resonance
states of mirror nuclei are displayed on an $E$-$\Gamma$ plane, these
parameters determine a rotation and a dilatation. With the help of these
parameters we found resonance states with strong, small and medium effects of
the Coulomb interaction. We also found two different scenarios of the motion of
resonance states due to the Coulomb interaction. The first standard (major)
scenario represent resonance states with the larger energy and larger width
than their counterparts have. The second rear scenario includes resonance
states with the larger energy but smaller width.",1905.07711v3
2019-05-24,Interaction between high intensity beam and structure resonances,"With the help of the linearized perturbation theory, the collective beam
instability due to the space charge, modelled by the Vlasov-Poisson equation,
is well studied in the former research theoretically in a general sense [Chao
Li and R. A. Jameson PRAB, 21, 024204 (2018)], where the related instability is
depicted by the ""structure resonance"". As an extension of the theoretical
study, this paper aims to verify the validity of the structure resonance with
numerical simulations and to show the basic principles which interpret the
interaction between structure resonance and beam in a general sense. It is
found that the reaction of beam to the structure resonance ($n\sigma\approx
180^\circ$) differs for the cases with $n= 0$ and $n\ne 0$ stop bands. The
non-resonant ""plasma oscillation"" is also revisited; the ""phase space mixing"",
lying in the transient plasma oscillation, is the mechanism that ties the
resonant effects, non-resonant effects and macroscopic beam phenomena together.",1905.10008v1
2020-07-18,Quenching effect of oscillating potential on anisotropic resonant transmission through a phosphorene electrostatic barrier,"The anisotropy in resonant tunneling transport through an electrostatic
barrier in mono layer black phosphorus either in presence or in absence of an
oscillating potential is studied. Non-perturbative Floquet theory is applied to
solve the time dependent problem and the results obtained are discussed
thoroughly. The resonance spectra in field free transmission are Lorentzian in
nature although the width of the resonance for the barrier along the zigzag
direction is too thinner than that for the armchair one. Resonant transmission
is suppressed for both the cases by the application of oscillating potential
that produces small oscillations in the transmission around the resonant energy
particularly at low frequency range. Sharp asymmetric Fano resonances are noted
in the transmission spectrum along the armchair direction while a distinct line
shape resonance is noted for the zigzag direction at higher frequency of the
oscillating potential. Even after the angular average, the conductance along
the armchair direction retains the characteristic Fano features that could be
observed experimentally. The present results are supposed to suggest that the
phosphorene electrostatic barrier could be used successfully as switching
devices and nano detectors.",2007.09356v2
2020-07-21,The Rayleigh-Lorentz Invariant and Optimal Adiabatic Qubit-Information Detection for Superconducting Qubit Resonators,"Dynamical properties of a resonator can be analyzed using the
Rayleigh-Lorentz invariant which is not an exact constant but varies more or
less over time. We investigate the time behavior of this invariant for a flux
qubit resonator in order for better understanding of qubit-information
detection with the resonator. Flux qubit resonators can be utilized in
implementing diverse next generation nano-optic and nano-electronic devices
such as quantum computing systems. Through the analyses of the temporal
evolution of the invariant, we derive a condition for optimal adiabatic
qubit-information detection with the resonator. This condition is helpful for
controlling the dynamics of qubit resonators over long periods of time. It is
necessary to consider it when designing a nano-resonator used for quantum
nondemolition readouts of qubit states, crucial in quantum computation.",2007.10671v1
2014-03-01,Universal quantum gates on microwave photons assisted by circuit quantum electrodynamics,"Based on a microwave-photon quantum processor with two superconducting
resonators coupled to one transmon qutrit, we construct the controlled-phase
(c-phase) gate on microwave-photon-resonator qudits, by combination of the
photon-number-dependent frequency-shift effect on the transmon qutrit by the
first resonator and the resonant operation between the qutrit and the second
resonator. This distinct feature provides us a useful way to achieve the
c-phase gate on the two resonator qudits with a higher fidelity and a shorter
operation time, compared with the previous proposals. The fidelity of our
c-phase gate can reach 99.51% within 93 ns. Moreover, our device can be
extended easily to construct the three-qudit gates on three resonator qudits,
far different from the existing proposals. Our controlled-controlled-phase gate
on three resonator qudits is accomplished with the assistance of a transmon
qutrit and its fidelity can reach 92.92% within 124.64 ns.",1403.0031v2
2014-03-10,Radiation-induced quantum Fano-type resonances in the transport of $N$-$P$-$N$ graphene based junctions,"We present a theoretical study of quantum resonances in the ballistic
transport of graphene based $N$-$P$-$N$ junction subject to an externally
applied electromagnetic field (EF). By making use of the Floquet analysis and
the quasi-classical approach we analyze the dynamics of electrons in the
presence of time and coordinate dependent potential $U(z,t)$. In the absence of
EF the resonant tunneling results in a set of sharp resonances in the
dependence of dc conductance $\sigma$ on the gate voltage $V_g$. In irradiated
$N$-$P$-$N$ junctions we obtain the Fano-type resonances in the dependence of
$\sigma(V_g)$. This \emph{coherent quantum-mechanical phenomenon} is due to the
interplay of two effects: the resonant tunneling through quasi-bound states and
the quantum-interference effect in the region between the ""resonant points"",
where the resonant absorption (emission) of photons occurs, and junction
interfaces.",1403.2206v2
2014-03-13,All-optical NMR in semiconductors provided by resonant cooling of nuclear spins interacting with electrons in the resonant spin amplification regime,"Resonant cooling of different nuclear isotopes manifested in
optically-induced nuclear magnetic resonances (NMR) is observed in n-doped
CdTe/(Cd,Mg)Te and ZnSe/(Zn,Mg)Se quantum wells and for donor-bound electrons
in ZnSe:F and GaAs epilayers. By time-resolved Kerr rotation used in the regime
of resonant spin amplification we can expand the range of magnetic fields where
the effect can be observed up to nuclear Larmor frequencies of 170 kHz. The
mechanism of the resonant cooling of the nuclear spin system is analyzed
theoretically. The developed approach allows us to model the resonant spin
amplification signals with NMR resonances.",1403.3288v1
2017-04-24,Above threshold scattering about a Feshbach resonance for ultracold atoms in an optical collider,"Ultracold atomic gases have realised numerous paradigms of condensed matter
physics where control over interactions has crucially been afforded by tunable
Feshbach resonances. So far, the characterisation of these Feshbach resonances
has almost exclusively relied on experiments in the threshold regime near zero
energy. Here we use a laser-based collider to probe a narrow magnetic Feshbach
resonance of rubidium above threshold. By measuring the overall atomic loss
from colliding clouds as a function of magnetic field, we track the
energy-dependent resonance position. At higher energy, our collider scheme
broadens the loss feature, making the identification of the narrow resonance
challenging. However, we observe that the collisions give rise to shifts in the
centre-of-mass positions of outgoing clouds. The shifts cross zero at the
resonance and this allows us to accurately determine its location well above
threshold. Our inferred resonance positions are in excellent agreement with
theory.",1704.07109v2
2017-04-26,On novel elastic structures inducing plasmonic resonances with finite frequencies and cloaking due to anomalous localized resonances,"This paper is concerned with the theoretical study of plasmonic resonances
for linear elasticity governed by the Lam\'e system in $\mathbb{R}^3$, and
their application for cloaking due to anomalous localized resonances. We derive
a very general and novel class of elastic structures that can induce plasmonic
resonances. It is shown that if either one of the two convexity conditions on
the Lam\'e parameters is broken, then we can construct certain plasmon
structures that induce resonances. This significantly extends the relevant
existing studies in the literature where the violation of both convexity
conditions is required. Indeed, the existing plasmonic structures are a
particular case of the general structures constructed in our study.
Furthermore, we consider the plasmonic resonances within the finite frequency
regime, and rigorously verify the quasi-static approximation for diametrically
small plasmonic inclusions. Finally, as an application of the newly found
structures, we construct a plasmonic device of the core-shell-matrix form that
can induce cloaking due to anomalous localized resonance in the quasi-static
regime, which also includes the existing study as a special case.",1704.07981v1
2018-05-10,A bottle of tea as a universal Helmholtz resonator,"Resonance is an ubiquitous phenomenon present in many systems. In particular,
air resonance in cavities was studied by Hermann von Helmholtz in the 1850s.
Originally used as acoustic filters, Helmholtz resonators are rigid-wall
cavities which reverberate at given fixed frequencies. An adjustable type of
resonator is the so-called universal Helmholtz resonator, a device consisting
of two sliding cylinders capable of producing sounds over a continuous range of
frequencies. Here we propose a simple experiment using a smartphone and normal
bottle of tea, with a nearly uniform cylindrical section, which, filled with
water at different levels, mimics a universal Helmholtz resonator. Blowing over
the bottle, different sounds are produced. Taking advantage of the great
processing capacity of smartphones, sound spectra together with frequencies of
resonance are obtained in real time.",1805.04014v1
2009-12-22,Spectral properties of a resonator driven by a superconducting single-electron transistor,"We analyze the spectral properties of a resonator coupled to a
superconducting single electron transistor (SSET) close to the Josephson
quasiparticle resonance. Focussing on the regime where the resonator is driven
into a limit-cycle state by the SSET, we investigate the behavior of the
resonator linewidth and the energy relaxation rate which control the widths of
the main features in the resonator spectra. We find that the linewidth becomes
very narrow in the limit-cycle regime, where it is dominated by a slow phase
diffusion process, as in a laser. The overall phase diffusion rate is
determined by a combination of direct phase diffusion and the effect of
amplitude fluctuations which affect the phase because the resonator frequency
is amplitude dependent. For sufficiently strong couplings we find that a regime
emerges where the phase diffusion is no longer minimized when the average
resonator energy is maximized. Finally we show that the current noise of the
SSET provides a way of measuring both the linewidth and energy relaxation rate.",0912.4462v1
2012-04-20,Stability of prograde and retrograde planets in circular binary systems,"We investigate the stability of prograde versus retrograde planets in
circular binary systems using numerical simulations. We show that retrograde
planets are stable up to distances closer to the perturber than prograde
planets. We develop an analytical model to compute the prograde and retrograde
mean motion resonances' locations and separatrices. We show that instability is
due to single resonance forcing, or caused by nearby resonances' overlap. We
validate our results regarding the role of single resonances and resonances'
overlap on orbit stability, by computing surfaces of section of the CR3BP. We
conclude that the observed enhanced stability of retrograde planets with
respect to prograde planets is due to essential differences between the
phase-space topology of retrograde versus prograde resonances (at p/q mean
motion ratio, prograde resonance is of order p - q while retrograde resonance
is of order p + q).",1204.4718v2
2014-05-01,Trapping a single vortex and reducing quasiparticles in a superconducting resonator,"Vortices trapped in thin-film superconducting microwave resonators can have a
significant influence on the resonator performance. Using a variable-linewidth
geometry for a weakly coupled resonator we are able to observe the effects of a
single vortex trapped in the resonator through field cooling. For resonant
modes where the vortex is near a current antinode, the presence of even a
single vortex leads to a measurable decrease in the quality factor and a
dispersive shift of the resonant frequency. For modes with the vortex located
at a current node, the presence of the vortex results in no detectable excess
loss and, in fact, produces an increase in the quality factor. We attribute
this enhancement to a reduction in the density of nonequilibrium quasiparticles
in the resonator due to the suppressed gap from the vortex.",1405.0256v2
2014-06-20,Effective Medium Theory for Elastic Metamaterials in Thin Elastic Plates,"An effective medium theory for resonant and non-resonant metamaterials for
flexural waves in thin plates is presented. The theory provides closed-form
expressions for the effective parameters of arrangement of inclusions or
resonators in thin plates as a function of the filling fraction of the
inclusions, their physical properties and the frequency. It is shown that
positive or negative effective elastic parameters are possible depending on the
symmetry of the resonance but, unlike it happens for bulk elastic waves, the
responsible for the negative mass density behaviour is the monopolar term,
while the negative Young's modulus and Poisson's ratio is due to the
combination of monopolar and quadrupolar resonances, showing also that, at
least for the first order in the scattering coefficients, the dipolar resonance
plays no role in the description of the effective medium. Several examples are
given for both non-resonant and resonant effective parameters and the results
are verified by multiple scattering theory.",1406.5400v2
2015-12-23,Particle number scaling for diffusion-induced dissipation in graphene and carbon nanotube nanomechanical resonators,"When a contaminant diffuses on the surface of a nanomechanical resonator, the
motions of the two become correlated. Despite being a high-order effect in the
resonator-particle coupling, such correlations affect the system dynamics by
inducing dissipation of the resonator energy. Here, we consider this
diffusion-induced dissipation in the cases of multiple particles adsorbed on
carbon nanotube and graphene resonators. By solving the stochastic equations of
motion, we simulate the ringdown of the resonator, in order to determine the
resonator energy decay rate. We find two different scalings with the number of
adsorbed particles $K$ and particle mass $m$. In the regime where the
adsorbates are inertially trapped at an antinode of vibration, the dissipation
rate $\Gamma$ scales with the total adsorbed mass $\Gamma\propto Km$. In
contrast, in the regime where particles diffuse freely over the resonator, the
dissipation rate scales as the product of the total adsorbed mass and the
individual particle mass: $\Gamma\propto Km^2$.",1512.07543v2
2016-05-01,"Tailoring Rydberg interactions via Förster resonances: state combinations, hopping and angular dependence","F\""orster resonances provide a highly flexible tool to tune both the strength
and the angular shape of interactions between two Rydberg atoms. We give a
detailed explanation about how F\""orster resonances can be found by searching
through a large range of possible quantum number combinations. We apply our
search method to $SS$, $SD$ and $DD$ pair states of $^{87}$Rb with principal
quantum numbers from 30 to 100, taking into account the fine structure
splitting of the Rydberg states. We find various strong resonances between
atoms with a large difference in principal quantum numbers. We quantify the
strength of these resonances by introducing a figure of merit $\tilde C_3$
which is independent of the magnetic quantum numbers and geometry to classify
the resonances by interaction strength. We further predict to what extent
excitation exchange is possible on different resonances and point out
limitations of the coherent hopping process. Finally, we discuss the angular
dependence of the dipole-dipole interaction and its tunability near resonances.",1605.00259v3
2016-05-27,Quantifying resonant and near-resonant interactions in rotating turbulence,"Nonlinear triadic interactions are at the heart of our understanding of
turbulence. In flows where waves are present modes must not only be in a triad
to interact, but their frequencies must also satisfy an extra condition: the
interactions that dominate the energy transfer are expected to be resonant. We
derive equations that allow direct measurement of the actual degree of
resonance of each triad in a turbulent flow. We then apply the method to the
case of rotating turbulence, where eddies coexist with inertial waves. We show
that for a range of wave numbers, resonant and near-resonant triads are
dominant, the latter allowing a transfer of net energy towards two-dimensional
modes that would be inaccessible otherwise. The results are in good agreement
with approximations often done in theories of rotating turbulence, and with the
mechanism of parametric instability proposed to explain the development of
anisotropy in such flows. We also observe that, at least for the moderate
Rossby numbers studied here, marginally near-resonant and non-resonant triads
play a non-negligible role in the coupling of modes.",1605.08818v2
2016-08-04,Resonances and multistability in a Josephson junction connected to a resonator,"We study the dynamics of a Josephson junction connected to a dc current
supply via a distributed parameter capacitor, which serves as a resonator. We
reveal multistability in the current-voltage characteristic of the system; this
multistability is related to resonances between the generated frequency and the
resonator. The resonant pattern requires detailed consideration, in particular,
because its basic features may resemble those of patterns reported in
experiments with arrays of Josephson junctions demonstrating coherent
stimulated emission. From the viewpoint of nonlinear dynamics, the resonances
between a Josephson junction and a resonator are of interest because of
specificity of the former; its oscillation frequency is directly governed by
control parameters of the system and can vary in a wide range. Our analytical
results are in good agreement with the results of numerical simulations.",1608.01462v3
2016-08-15,Precession resonance in water waves,"We describe the theory and present numerical evidence for a new type of
nonlinear resonant interaction between gravity waves on the surface of deep
water. The resonance constitutes a generalisation of the usual 'exact'
resonance as we show that exchanges of energy between the waves can be enhanced
when the interaction is three-wave rather than four and the linear frequency
mismatch, or detuning, is non-zero i.e. $\omega_1\pm\omega_2\pm\omega_3 \neq0.$
This is possible because the resonance condition is now a match between the
so-called 'precession frequency' of a given $\textit{triad interaction}$ and an
existent nonlinear frequency in the system. In the limit of weak nonlinearity
this precession frequency is simply due to the linear 'drift' of the triad
phase; therefore, it tends toward the detuning. This means precession resonance
of this type can occur at finite amplitudes, with nonlinear corrections
contributing to the resonance. We report energy transfer efficiencies of up to
40%, depending on the model options. To the authors' knowledge this represents
the first new type of nonlinear resonance in surface gravity waves since the
seminal work of Benjamin & Feir (1967).",1608.04241v1
2016-08-22,Metallic coplanar resonators optimized for low-temperature measurements,"Metallic coplanar microwave resonators are widely employed at room
temperature, but their low-temperature performance has received little
attention so far. We characterize compact copper coplanar resonators with
multiple modes from 2.5 to 20 GHz at temperatures as low as 5 K. We investigate
the influence of center conductor width (20 to 100 {\mu}m) and coupling gap
size (10 to 50 {\mu}m), and we observe a strong increase of quality factor (Q)
for wider center conductors, reaching values up to 470. The magnetic-field
dependence of the resonators is weak, with a maximum change in Q of 3.5% for an
applied field of 7 T. This makes these metallic resonators well suitable for
magnetic resonance studies, as we document with electron spin resonance (ESR)
measurements at multiple resonance frequencies.",1608.06122v1
2016-12-15,Chaos in some young asteroid families,"Asteroid families are groups of minor planets that have a common origin in
breakup events. The very young compact asteroid clusters are the natural
laboratory to study resonance related chaotic and nonlinear dynamics. The
present dynamical configurations and evolution of asteroid associations
strongly depends on their ages. In present paper we allocate subclass of very
young asteroid families (younger than 1 Myr). We show that resonance-related
chaos can play a very important role in dynamics of very young asteroid
families. In case of Datura family chaos may be explained by high order mean
motion resonance 9:16 with Mars. In case Hobson family chaos is affected by
secular resonance. In other considered cases (Kapbos cluster and Lucascavin
cluster) origin of chaotic behavior is still unknown. The effect of resonance
is very selective in all cases: we see very stable orbits in the vicinity of
chaotic ones. In the high order resonance transfer from initial to final orbit
take place by temporary capture in exact resonance. The large asteroids (Ceres,
Vesta) can made significant effect on dynamic of small bodies in resonance. In
some cases (as for Datura and Lucascavin family), their perturbations can
extend area of chaotic motion.",1612.04951v1
2017-06-07,High-Q supercavity modes in subwavelength dielectric resonators,"Recent progress in nanoscale optical physics is associated with the
development of a new branch of nanophotonics exploring strong Mie resonances in
dielectric nanoparticles with high refractive index. The high-index resonant
dielectric nanostructures form building blocks for novel photonic metadevices
with low losses and advanced functionalities. However, unlike extensively
studied cavities in photonic crystals, such dielectric resonators demonstrate
low quality factors (Q-factors). Here, we uncover a novel mechanism for
achieving giant Q-factors of subwavelength nanoscale resonators by realizing
the regime of bound states in the continuum. We reveal strong mode coupling and
Fano resonances in high-index dielectric finite-length nanorods resulting in
high-Q factors at the nanoscale. Thus, high-index dielectric resonators
represent the simplest example of nanophotonic supercavities, expanding
substantially the range of applications of all-dielectric resonant
nanophotonics and meta-optics.",1706.02099v1
2017-07-11,Andreev reflection assisted lasing in an electromagnetic resonator coupled to a hybrid-quantum-dot,"A single mode electromagnetic resonator coupled to a two-level
hybrid-quantum-dot(hQD) is studied theoretically as a laser(maser), when the
hQD is driven out of equilibrium with external applied d.c. bias voltage. Using
the formalism of the non-equilibrium Green's functions for the hQD and the
semi-classical laser equations, we determine the relevant physical quantities
of the system. We find that due to the resonant Andreev reflections and the
formation of the Floquet-Andreev side-resonances in the sub-gap region, at
appropriate gate voltages and above a certain threshold bias voltage and
damping factor of the resonator, the two-level QD has non-zero gain spectrum
and lasing can happen in the system in the frequency range of superconducting
gap. Furthermore, our results show that depending on the damping factor of the
resonator and above a specific threshold bias voltages, the lasing can be
either due to single electron transitions or cascaded electron transitions
between the Andreev resonances and Floquet-Andreev side-resonances.",1707.03219v2
2017-10-09,Observation of Feshbach resonances between alkali and closed-shell atoms,"Magnetic Feshbach resonances are an invaluable tool for controlling ultracold
atoms and molecules. They can be used to tune atomic interactions and have been
used extensively to explore few- and many-body phenomena. They can also be used
for magnetoassociation, in which pairs of atoms are converted into molecules by
ramping an applied magnetic field across a resonance. Pairs of open-shell
atoms, such as the alkalis, chromium, and some lanthanides, exhibit broad
resonances because the corresponding molecule has multiple electronic states.
However, molecules formed between alkali and closed-shell atoms have only one
electronic state and no broad resonances. Narrow resonances have been predicted
in such systems, but until now have eluded observation. Here we present the
first observation of magnetic Feshbach resonances in a system containing a
closed-shell atom, Sr, interacting with an alkali atom, Rb. These resonances
pave the way to creating an ultracold gas of strongly polar, open-shell
molecules, which will open up new possibilities for designing quantum many-body
systems and for tests of fundamental symmetries.",1710.03093v1
2017-10-19,Tracking the resonant frequency of a micromechanical resonator using phononic frequency combs,"Micro and nanomechanical resonators have been extensively researched in
recent decades for applications to time and frequency references, as well as
highly sensitive sensors. Conventionally, the operation of these resonant
sensors is practically implemented using a feedback oscillator to dynamically
track variations in the resonant frequency. However, this approach places
limitations on the frequency stability of the output response, particularly
owing to near-carrier phase noise, potentially limiting measurements over long
integration times. Here, in this paper, utilizing the recent experimental
demonstration of phononic frequency combs, we demonstrate an alternative
resonant tracking approach with the potential to provide significant
improvements in near-carrier phase noise and long-term stability. In addition,
we also showcase comb dynamics mediated resonant frequency modulation which
indirectly points to the possible control of inevitable noise processes
including thermomechanical fluctuations. This resonant tracking approach may
also have general applicability to a number of other physical oscillators.",1710.07058v3
2018-01-26,Strong indirect coupling between graphene-based mechanical resonators via a phonon cavity,"Mechanical resonators are promising systems for storing and manipulating
information. To transfer information between mechanical modes, either direct
coupling or an interface between these modes is needed. In previous works,
strong coupling between different modes in a single mechanical resonator and
direct interaction between neighboring mechanical resonators have been
demonstrated. However, coupling between distant mechanical resonators, which is
a crucial request for long-distance classical and quantum information
processing using mechanical devices, remains an experimental challenge. Here,
we report the experimental observation of strong indirect coupling between
separated mechanical resonators in a graphene-based electromechanical system.
The coupling is mediated by a far-off-resonant phonon cavity through virtual
excitations via a Raman-like process. By controlling the resonant frequency of
the phonon cavity, the indirect coupling can be tuned in a wide range. Our
results may lead to the development of gate-controlled all-mechanical devices
and open up the possibility of long-distance quantum mechanical experiments.",1801.08752v1
2018-09-28,Towards the Minimal Spectrum of Excited Baryons,"In the light baryon sector resonances can be broad and overlapping and are in
most cases not directly visible in the cross section data. Automatized model
selection techniques that introduce penalties for resonances can be used to
determine the minimally needed set of resonances to describe the data. Several
possible penalization schemes are compared. As an application we perform a
blindfold identification of hyperon resonances in the $\bar{K} N \to K \Xi$
reaction based on the Least Absolute Shrinkage and Selection Operator (LASSO)
in combination with the Bayesian Information Criterion (BIC). We find ten
resonances --- out of the 21 above-threshold hyperon resonances with spin $J\le
7/2$ listed by the Particle Data Group. In traditional analyses, it is
practically impossible to test the relevance of all resonances and their
combinations that may potentially contribute to the reaction. By contrast, the
present method proves capable of determining the relevant resonances among a
large pool of candidates.",1810.00075v2
2018-10-05,Resonant spectra of multipole-bound anions,"In multipole-bound anions, the excess electron is attached by a short-range
multipole potential of a neutral molecule. Such anions are prototypical
marginally-bound open quantum systems. In particular, around the critical
multipole moment required to attach the valence electron, multipole-bound
anions exhibit critical behavior associated with a transition from bound states
dominated by low-$\ell$ partial waves to the electron continuum. In this work,
multipole-bound anions are described using a nonadiabatic electron-plus-rotor
model. The electron-molecule pseudo-potential is represented by a short-range
multipole field with a Gaussian form-factor. The resulting coupled-channel
Schr\""odinger equation is solved by means of the Berggren expansion method, in
which the electron's wave function is decomposed into bound states, narrow
resonances, and the non-resonant scattering continuum. We show that the
Gaussian model predicts the critical transition at the detachment threshold.
Resonant states, including bound states, decaying resonances, subthreshold
resonances, and antibound states are studied, and exceptional points where two
resonant states coalesce are predicted. We discuss the transition of rotational
band structures around the threshold and study the effects of channel coupling
on the decay width of resonant poles.",1810.02806v2
2018-10-25,Black resonators and geons in AdS$_5$,"We construct dynamical black hole solutions with a helical symmetry in
AdS$_5$, called black resonators, as well as their horizonless limits, called
geons. We introduce a cohomogeneity-1 metric describing a class of black
resonators and geons whose isometry group is $R\times SU(2)$. This allows us to
study them in a wide range of parameters. We obtain the phase diagram for the
black resonators, geons, and Myers-Perry-AdS$_5$, where the black resonators
emerge from the onset of a superradiant instability of the Myers-Perry-AdS$_5$
with equal angular momenta and are connected to the geons in the small horizon
limit. The angular velocities of the black resonators always satisfy $\Omega>1$
in units of the AdS radius. A black resonator is shown to have higher entropy
than a Myers-Perry-AdS$_5$ black hole with the same asymptotic charges. This
implies that the Myers-Perry-AdS$_5$ can dynamically evolve into the black
resonator under the exact $SU(2)$-symmetry although its endpoint will be
further unstable to $SU(2)$-violating perturbations.",1810.11089v2
2019-06-26,Chiral quantum optics using a topological resonator,"Topological photonic structures exhibit chiral edge states that are robust to
disorder and sharp bends. When coupled to quantum emitters, these edge states
generate directional light emission that enables unprecedented control of
interactions between light and matter in a nanophotonic device. While
directional light emission in one-dimensional topological, as well as
conventional, waveguides has been previously demonstrated, the extension of
these concepts to resonator structures that enhance light-matter coupling
remains challenging. Here we demonstrate chiral lightmatter interactions in a
topological resonator. We employ valley-Hall topological edge states to realize
a helical resonator at the interface of two topologically distinct regions.
Such a helical resonator has two counter-propagating modes with opposite
polarizations. We show chiral coupling of the resonator to a quantum emitter
resulting in a Purcell enhancement of 3.4 due to resonant coupling. Such chiral
resonators could enable designing complex nanophotonic circuits for quantum
information processing, and studying novel quantum many-body dynamics.",1906.11263v2
2019-09-24,Tuning high-Q superconducting resonators by magnetic field reorientation,"Superconducting resonators interfaced with paramagnetic spin ensembles are
used to increase the sensitivity of electron spin resonance experiments and are
key elements of microwave quantum memories. Certain spin systems that are
promising for such quantum memories possess 'sweet spots' at particular
combinations of magnetic fields and frequencies, where spin coherence times or
linewidths become particularly favorable. In order to be able to couple high-Q
superconducting resonators to such specific spin transitions, it is necessary
to be able to tune the resonator frequency under a constant magnetic field
amplitude. Here, we demonstrate a high quality, magnetic field resilient
superconducting resonator, using a 3D vector magnet to continuously tune its
resonance frequency by adjusting the orientation of the magnetic field. The
resonator maintains a quality factor of $> 10^5$ up to magnetic fields of 2.6
T, applied predominantly in the plane of the superconductor. We achieve a
continuous tuning of up to 30 MHz by rotating the magnetic field vector,
introducing a component of 5 mT perpendicular to the superconductor.",1909.11020v3
2020-02-24,Nuclear multipole responses from chiral effective field theory interaction,"We probe nuclear multipole resonances in the framework of the random-phase
approximation by using the interaction obtained from the chiral effective field
theory. The three-nucleon force is included in a form of the in-medium
two-nucleon interaction which was derived from the chiral three-nucleon force.
The isoscalar monopole, isoscalar dipole, isovector dipole and isoscalar
quadrupole resonances of the closed-shell $^{56,68,78}$Ni have been
investigated. The calculations reasonably reproduce the experimental multipole
resonances of $^{56,68}$Ni, and well describe the pygmy dipole resonance and
dipole polarizability measured in $^{68}$Ni. The multipole resonances of
$^{78}$Ni, including pygmy dipole resonance and dipole polarizability, are
predicted. The detailed effects of the tensor force and three-body force are
analyzed by dissecting the chiral interaction. We find that in general the
tensor force effect on electric giant resonances is not as significant as the
effect from the three-body force, although the tensor force provides more than
half of the binding energy. The effect from three-body force is strong in light
nuclei. Particularly, three-body force is crucial for the formation of the
pygmy resonance in calculations.",2002.10048v1
2020-02-26,Symmetry analysis and multipole classification of eigenmodes in electromagnetic resonators for engineering their optical properties,"The resonator is one of the main building blocks of a plethora of photonic
and microwave devices from nanolasers to compact biosensors and magnetic
resonance scanners. The symmetry of the resonators is tightly related to their
mode structure and multipole content which determines the linear and non-linear
response of the resonator. Here, we develop the algorithm for the
classification of eigenmodes in resonators of the simplest shapes depending on
their symmetry group. For each type of mode, we find its multipole content. As
an illustrative example, we apply the developed formalism to the analysis of
dielectric triangular prism and demonstrate the formation of high-Q resonances
originated due to suppression of the scattering through the main multipole
channel. The developed approach one to engineer, predict, and explain
scattering phenomena and optical properties of resonators and meta-atmos basing
only on their symmetry without the need for numerical simulations and it can be
used for the design of new photonic and microwave devices.",2002.11411v1
2020-04-24,Dynamics and multiqubit entanglement in distant resonators,"We consider the dynamics of the photon states in distant resonators coupled
to a common bus resonator at different positions. The frequencies of distant
resonators from a common bus resonator are equally detuned. These frequency
detunings are kept larger than the coupling strengths of each resonator to the
common bus resonator to satisfy the dispersive interaction regime. In the
dispersive regime, we show that the time dynamics of the system evolve to an
arbitrary W-type state in a single step at various interaction times. Our
results show that a one-step generation of arbitrary W-type states can be
achieved with high fidelity in a system of superconducting resonators.",2004.12008v1
2018-03-19,Sensorless Resonance Tracking of Resonant Electromagnetic Actuator through Back-EMF Estimation for Mobile Devices,"Resonant electromagnetic actuators have been broadly used as vibration motors
for mobile devices given their ability of generating relatively fast, strong,
and controllable vibration force at a given resonant frequency. Mechanism of
the actuators that is based on mechanical resonance, however, limits their use
to a situation where their resonant frequencies are known and unshifted. In
reality, there are many factors that alter the resonant frequency: for example,
manufacturing tolerances, worn mechanical components such as a spring,
nonlinearity in association with different input voltage levels. Here, we
describe a sensorless resonance tracking method that actuates the motor and
automatically detects its unknown damped natural frequency through the
estimation of back electromotive force (EMF) and inner mass movements. We
demonstrate the tracking performance of the proposed method through a series of
experiments. This approach has the potential to control residual vibrations and
then improve vibrotactile feedback, which can potentially be used for
human-computer interaction, cognitive and affective neuroscience research.",1803.07065v1
2018-03-30,Bloch-Floquet waves in optical ring resonators,"Modal coupling between frequency-degenerate resonances of an optical ring
resonator is a commonly observed phenomenon that results in adverse mode
splitting. Traditionally, this coupling is attributed to Rayleigh scattering of
a propagating electromagnetic wave into its associated degenerate
counter-propagating mode from small perturbations to the dielectric material of
the resonator. We have chosen to reframe the problem of intracavity Rayleigh
scattering by considering the optical ring resonator as an infinitely-long,
one-dimensional photonic crystal (PhC) that possesses a lattice constant equal
to the perimeter of the ring. Through application of Bloch-Floquet theory, we
show that modal coupling between degenerate resonances of a ring can
effectively be described as the formation of photonic frequency bands in the
dispersion relation of the resonator. We additionally demonstrate that the
Bragg planes of the PhC lattice coincide with the phase matching conditions for
constructive interference in the ring. Finally, we show that the magnitude of
frequency splitting of a particular resonance is proportional to its associated
coefficient in the Fourier expansion of the ring's periodic dielectric
function.",1803.11312v1
2018-06-05,A tunable quantum dissipator for active resonator reset in circuit QED,"We propose a method for fast, deterministic resonator reset based on tunable
dissipative modes. The dissipator is based on a Josephson junction with
relatively low quality factor. When the dissipator is tuned into resonance with
a high quality microwave resonator, resonator photons are absorbed by the
dissipator at a rate orders of magnitude faster than the resonator relaxation
rate. We determine the optimal parameters for realization of the tunable
dissipator, and examine application of the dissipator to removing spurious
photon population in the qubit readout resonator in circuit quantum
electrodynamics. We show that even in the nonlinear large photon occupation
regime, this enhanced resonator decay rate can be attained by appropriate
modulation of the dissipator frequency.",1806.01880v3
2018-07-20,"Strength, stability and three dimensional structure of mean motion resonances in the Solar System","In the framework of the circular restricted three body problem we show that
the numerically computed strength SR(e,i,w) is a good indicator of the strength
and width of the mean-motion resonances in the full space (e,i,w). We present a
survey of strengths in the space (e,i) for typical interior and exterior
resonances. The resonance strength is highly dependent on (e,i,w) except for
exterior resonances of the type 1:k for which the dependence with (i,w) is
softer. Such resonances are thus strong even for retrograde orbits. All other
resonances are weaker at very-high eccentricities for w ~ 90 or 270 and 60 < i
< 120. We explore the resonance structure in the space (a,i) by means of
dynamical maps and we find structures similar to those of space (a,e).",1807.07956v1
2018-08-24,Superconducting circuit quantum computing with nanomechanical resonators as storage,"We analyze the quantum information processing capability of a superconducting
transmon circuit used to mediate interactions between quantum information
stored in a collection of phononic crystal cavity resonators. Having only a
single processing element to be controlled externally makes this approach
significantly less hardware-intensive than traditional architectures with
individual control of each qubit. Moreover, when compared with the commonly
considered alternative approach using coplanar waveguide or 3d cavity microwave
resonators for storage, the nanomechanical resonators offer both very long
lifetime and small size -- two conflicting requirements for microwave
resonators. A detailed gate error analysis leads to an optimal value for the
qubit-resonator coupling rate as a function of the number of mechanical
resonators in the system. For a given set of system parameters, a specific
amount of coupling and number of resonators is found to optimize the quantum
volume, an approximate measure for the computational capacity of a system. We
see this volume is higher in the proposed hybrid nanomechanical architecture
than in the competing on-chip electromagnetic approach.",1808.08216v1
2018-12-20,Photoconductive Heaters Enable Control of Large-Scale Silicon Photonic Ring Resonator Circuits,"A multitude of large-scale silicon photonic systems based on ring resonators
have been envisioned for applications ranging from biomedical sensing to
quantum computing and machine learning. Yet, due to the lack of a scalable
solution for controlling ring resonators, practical demonstrations have been
limited to systems with only a few rings. Here, we demonstrate that large
systems can be controlled by using only doped waveguide elements inside their
ringswhile preserving their area and cost. We measure the large photoconductive
changes of the waveguides for monitoring the rings' resonance conditions across
high-dynamic ranges and leverage their thermo-optic effects for tuning. This
allows us to control ring resonators without requiring additional components,
complex tuning algorithms, or additional electrical I/Os. We demonstrate
automatic resonance alignment of 31 rings of a 16 x 16 switch and of a 14-ring
coupled resonator optical waveguide, making them the largest, yet most compact,
automatically controlled silicon ring resonator circuits to date, to the best
of our knowledge.",1812.09317v2
2018-12-22,Lattice effect on electric and magnetic resonance overlap in periodic array,"Designing the shape of silicon nanoparticles has been shown to be an
effective approach to increasing overlap between electric and magnetic dipole
resonances thereby achieving directional scattering and decrease of reflection.
Variations of disk diameter and/or height affect resonances differently and can
thus result in resonance overlap. In most of the studies, the disks are
arranged in a periodic array where the periodicity is varied together with disk
diameter, but the role of lattice effect is neglected. Here we theoretically
study a periodic array of disks and show that the contribution of the lattice
effect in shifting resonance positions is comparable to the effect of the
diameter change. We demonstrate that the lattice effect is important even when
the wavelength of diffraction remains on the blue side from electric and
magnetic dipole resonances and there are no additional lattice resonances are
excited. Period and disk dimensions are chosen so that the resonances overlap
in the proximity of the telecommunication wavelength which is of great
practical interest.",1812.09465v1
2019-03-14,Camera detection and modal fingerprinting of photonic crystal nanobeam resonances,"We demonstrate in simulation and experiment that the out-of-plane, far-field
scattering profile of resonance modes in photonic crystal nanobeam (PCN)
cavities can be used to identify resonance mode order. Through detection of
resonantly scattered light with an infrared camera, the overlap between optical
resonance modes and the leaky region of k-space can be measured experimentally.
Mode order dependent overlap with the leaky region enables usage of resonance
scattering as a ""fingerprint"" by which resonant modes in nanophotonic
structures can be identified via detection in the far-field. By selectively
observing emission near the PCN cavity region, the resonant scattering profile
of the device can be spatially isolated and the signal noise introduced by
other elements in the transmission line can be significantly reduced,
consequently improving the signal to noise ratio (SNR) of resonance detection.
This work demonstrates an increase in SNR of ~19 dB in out-of-plane scattering
measurements over in-plane transmission measurements. The capabilities
demonstrated here may be applied to improve characterization across
nanophotonic devices with mode-dependent spatial field profiles and enhance the
utility of these devices across a variety of applications.",1903.06244v1
2019-03-15,Root Cones and the Resonance Arrangement,"We study the connection between triangulations of a type $A$ root polytope
and the resonance arrangement, a hyperplane arrangement that shows up in a
surprising number of contexts. Despite an elementary definition for the
resonance arrangement, the number of resonance chambers has only been computed
up to the $n=8$ dimensional case. We focus on data structures for labeling
chambers, such as sign vectors and sets of alternating trees, with an aim at
better understanding the structure of the resonance arrangement, and, in
particular, enumerating its chambers. Along the way, we make connections with
similar (and similarly difficult) enumeration questions. With the root polytope
viewpoint, we relate resonance chambers to the chambers of polynomiality of the
Kostant partition function. With the hyperplane viewpoint, we clarify the
connections between resonance chambers and threshold functions. In particular,
we show that the base-2 logarithm of the number of resonance chambers is
asymptotically $n^2$.",1903.06595v2
2019-08-06,New islands of stability with double-trace deformations,"We assess the role of a resonant spectrum in the AdS instability, and
quantify the extent to which breaking the resonant spectrum of AdS can restore
stability. Specifically, we study non-collapsing `multi-oscillator' solutions
in AdS under various boundary conditions that allow for both resonant and
non-resonant spectra. We find non-collapsing two mode, equal amplitude
solutions in the non-resonant Robin case, and that these solutions vanish in
the fully resonant Dirichlet case. This is consistent with non-resonant
stability, and with the idea that stable solutions in the Dirichlet case are
all single-mode dominated. Surprisingly, when the boundary condition is
Neumann, we find non-collapsing solutions arbitrarily close to AdS that are not
single-mode dominated, despite the spectrum being fully resonant.",1908.02296v1
2019-08-19,Resonant excitation of whistler waves by a helical electron beam,"Chorus-like whistler-mode waves that are known to play a fundamental role in
driving radiation-belt dynamics are excited on the Large Plasma Device by the
injection of a helical electron beam into a cold plasma. The mode structure of
the excited whistler wave is identified using a phase-correlation technique
showing that the waves are excited through a combination of Landau resonance,
cyclotron resonance and anomalous cyclotron resonance. The dominant wave mode
excited through cyclotron resonance is quasi-parallel propagating, whereas wave
modes excited through Landau resonance and anomalous cyclotron resonance
propagate at oblique angles that are close to the resonance cone. An analysis
of the linear wave growth rates captures the major observations in the
experiment. The results have important implications for the generation process
of whistler waves in the Earth's inner magnetosphere.",1908.06952v1
2019-08-30,A case study about the mass exclusion limits for the BSM vector resonances with the direct couplings to the third quark generation,"The upper bounds that the LHC measurements searching for heavy resonances
beyond the Standard model set on the resonance production cross sections are
not universal. They depend on various characteristics of the resonance under
consideration, like its mass, spin, and its interaction pattern. Their validity
are also limited by the assumptions and approximations applied to their
calculations. The bounds are typically used to derive the mass exclusion limits
for the new resonances. In our work, we address some of the issues that emerge
when deriving the mass exclusion limits for the strongly coupled composite
$SU(2)_{L+R}$ vector resonance triplet which would interact directly to the
third quark generation only. We investigate the restrictions on the
applicability of the generally used limit-obtaining procedure to this
particular type of vector resonances. We demonstrate that, in this case, it is
necessary to consider the bottom quark partonic contents of the proton.
Eventually, we find the mass exclusion limits for this resonance triplet for
some representative subsets of the parameter space.",1908.11619v2
2019-11-27,"Spatial Resolution, Sensitivity and Surface Selectivity in Resonant Mode Photothermal Induced Resonance Spectroscopy","Photothermal-Induced Resonance (PTIR) is increasingly used in the measurement
of infrared absorption spectra of sub-micrometer objects. The technique
measures IR absorption spectra by relying on the photothermal effect induced by
a rapid pulse of light and the excitation of the resonance spectrum of an AFM
cantilever in contact with the sample. In this work we assess the spatial
resolution and depth response of PTIR in resonant mode while systematically
varying the pulsing frequency of the excitation laser and the cantilever
resonance. The spatial resolution shows a shallow linear dependence on the
inverse of the pulse frequency, which rules out tip size as a limiting factor
for resolution in the frequency range under investigation. Measured resolution
values are also one order of magnitude lower than in the thermal diffusion
limit, excluding thermal wave propagation as a limiting factor. We also show
that the pulsing frequency of the laser and choice of cantilever resonance
affect the intensity of the signal and the surface selectivity in PTIR images,
with higher frequencies providing increased surface selectivity. The results
confirm a difference in signal generation between resonant PTIR and other
photothermal techniques and indicate that photothermal induced heating and
expansion cannot fully account for observed intensity and resolution.",1911.12097v1
2019-12-10,Resonances in the Earth's Space Environment,"We study the presence of resonances in the region of space around the Earth.
We consider a massless body (e.g, a dust particle or a small space debris)
subject to different forces: the gravitational attraction of the geopotential,
the effects of Sun and Moon. We distinguish different types of resonances:
tesseral resonances are due to a commensurability involving the revolution of
the particle and the rotation of the Earth, semi-secular resonances include the
rates of variation of the mean anomalies of Moon and Sun, while secular
resonances just depend on the rates of variation of the arguments of perigee
and the longitudes of the ascending nodes of the perturbing bodies. We
characterize such resonances, giving precise statements on the regions where
the resonances can be found and provide examples of some specific
commensurability relations.",1912.04593v1
2020-03-04,Breaking Resonant Chains: Destabilization of Resonant Planets due to Long-term Mass Evolution,"Recent exoplanet observations reported a large number of multiple-planet
systems, in which some of the planets are in a chain of resonances. The
fraction of resonant systems to non-resonant systems provides clues about their
formation history. We investigated the orbital stability of planets in resonant
chains by considering the long-term evolution of planetary mass and stellar
mass and using orbital calculations. We found that while resonant chains were
stable, they can be destabilized by a change of $\sim$10% in planetary mass.
Such a mass evolution can occur by atmospheric escape due to photoevaporation.
We also found that resonant chains can be broken by a stellar mass loss of
$\lesssim1$%, which would be explained by stellar winds or coronal mass
ejections. The long-term mass change of planets and stars plays an important
role in the orbital evolutions of planetary systems including super-Earths.",2003.01965v1
2020-05-13,Identification and characterization of high order incoherent space charge driven structure resonances in the CERN Proton Synchrotron,"Space charge is typically one of the performance limitations for the
operation of high intensity and high brightness beams in circular accelerators.
In the Proton Synchrotron (PS) at CERN, losses are observed for vertical tunes
above $Q_y=6.25$, especially for beams with large space charge tune shift. The
work presented here shows that this behaviour is associated to structure
resonances excited by space charge due to the highly symmetric accelerator
lattice of the PS, typical for first generation alternating gradient
synchrotrons. Experimental studies demonstrate the dependency of the losses on
the beam brightness and the harmonic of the resonance, and simulation studies
reveal the incoherent nature of the resonance. Furthermore, the calculation of
the Resonance Driving Terms (RDT) generated by the space charge potential shows
that the operational working point of the PS is surrounded by multiple space
charge driven incoherent resonances. Finally, measurements and simulations on
both lattice driven and space charge driven resonances illustrate the different
behaviour of the beam loss depending on the source of the resonance excitation
and on the beam brightness.",2005.06575v1
2020-06-16,Enhancing nonlinear damping by parametric-direct internal resonance,"Mechanical sources of nonlinear damping play a central role in modern
physics, from solid-state physics to thermodynamics. The microscopic theory of
mechanical dissipation [M. I . Dykman, M. A. Krivoglaz, Physica Status Solidi
(b) 68, 111 (1975)] suggests that nonlinear damping of a resonant mode can be
strongly enhanced when it is coupled to a vibration mode that is close to twice
its resonance frequency. To date, no experimental evidence of this enhancement
has been realized. In this letter, we experimentally show that nanoresonators
driven into parametric-direct internal resonance provide supporting evidence
for the microscopic theory of nonlinear dissipation. By regulating the drive
level, we tune the parametric resonance of a graphene nanodrum over a range of
40-70 MHz to reach successive two-to-one internal resonances, leading to a
nearly two-fold increase of the nonlinear damping. Our study opens up an
exciting route towards utilizing modal interactions and parametric resonance to
realize resonators with engineered nonlinear dissipation over wide frequency
range.",2006.09364v3
2020-08-04,J/ψ-pair resonances by LHCb: a new revolution?,"A comment on the LHCb discovery of J/psi-pair resonances. To appear in
Science Bulletin as a NEWS and VIEWS Paper.",2008.01637v1
2020-09-04,Strong zero-field Förster resonances in K-Rb Rydberg systems,"We study resonant dipole-dipole coupling and the associated van der Waals
energy shifts in Rydberg excited atomic rubidium and potassium and investigate
F\""orster resonances between interspecies pair states. A comprehensive survey
over experimentally accessible pair state combinations reveals multiple
candidates with small F\""orster defects. We crucially identify the existence of
an ultrastrong, ""low"" electric field K-Rb F\""orster resonance with a extremely
large zero-field crossover distance exceeding 100 $\mu$m between the van der
Waals regime and the resonant regime. This resonance allows for a strong
interaction over a wide range of distances and by investigating its dependence
on the strength and orientation of external fields we show this to be largely
isotropic. As a result, the resonance offers a highly favorable setting for
studying long-range resonant excitation transfer and entanglement generation
between atomic ensembles in a flexible geometry. The two-species K-Rb system
establishes a unique way of realizing a Rydberg single-photon optical
transistor with a high-input photon rate and we specifically investigate an
experimental scheme with two separate ensembles.",2009.02004v1
2020-09-25,Lorentz Resonance in the Homogenization of Plasmonic Crystals,"We explain the Lorentz resonances in plasmonic crystals that consist of 2D
nano dielectric inclusions as the interaction between resonant material
properties and geometric resonances of electrostatic nature. One example of
such plasmonic crystals are graphene nanosheets that are periodically arranged
within a non-magnetic bulk dielectric. We identify local geometric resonances
on the length scale of the small scale period. From a materials perspective,
the graphene surface exhibits a dispersive surface conductance captured by the
Drude model. Together these phenomena conspire to generate Lorentz resonances
at frequencies controlled by the surface geometry and the surface conductance.
The Lorentz resonances found in the frequency response of the effective
dielectric tensor of the bulk metamaterial is shown to be given by an explicit
formula, in which material properties and geometric resonances are decoupled.
This formula is rigorous and obtained directly from corrector fields describing
local electrostatic fields inside the heterogeneous structure. Our analytical
findings can serve as an efficient computational tool to describe the general
frequency dependence of periodic optical devices. As a concrete example, we
investigate two prototypical geometries composed of nanotubes and nanoribbons.",2009.12166v2
2020-10-12,One- and two-dimensional correlation spectroscopy analyses for resonant and non-resonant coherent nonlinear optical processes,"Three-color coherent anti-Stokes Raman scattering represents non-degenerate
four wave mixing process that includes both a non-resonant and resonant
processes, the contributions of which depend on how the molecular vibrational
modes are being excited by the input laser pulses. Non-degenerate four wave
mixing processes are complex and understanding these processes requires
rigorous data analytical tools, which still lack in this research field. In
this work, we introduce one- and two-dimensional intensity-intensity
correlation functions in terms of a new variable (e.g., probe pulse delay) and
new perturbation parameter (e.g., probe pulse linewidth). In particular,
diagonal projections are defined here as a tool to reduce both synchronous and
asynchronous two-dimensional correlation spectroscopy analyses down to
one-dimensional analysis, revealing valuable analytical information. Detailed
analyses using the all Gaussian coherent Raman scattering closed-form solutions
and the representative experimental data for resonant and non-resonant
processes are presented and compared. This intensity-intensity correlation
analytical tool holds a promising potential in resolving and visualizing
resonant versus non-resonant four wave mixing processes for quantitative
label-free species-specific nonlinear spectroscopy and microscopy.",2010.06017v1
2020-10-31,Long-term dynamics driven by resonant wave-particle interactions: from Hamiltonian resonance theory to phase space mapping,"In this study we consider the Hamiltonian approach for the construction of a
map for a system with nonlinear resonant interaction, including phase trapping
and phase bunching effects. We derive basic equations for a single resonant
trajectory analysis and then generalize them into the map in the
energy/pitch-angle space. The main advances of this approach are the
possibility to consider effects of many resonances and to simulate the
evolution of the resonant particle ensemble on long time ranges. For
illustrative purposes we consider the system with resonant relativistic
electrons and field-aligned whistler-mode waves. The simulation results show
that the electron phase space density within the resonant region is flattened
with reduction of gradients. This evolution is much faster than the predictions
of quasi-linear theory. We discuss further applications of the proposed
approach and possible ways for its generalization.",2011.00208v1
2021-02-20,Effect of internal resonance on the dynamics of MoS2 resonator,"Nonlinear modal interactions and associated internal resonance phenomena have
recently been used to demonstrate improved oscillator performance and enhanced
sensing capabilities. Here, we show tunable modal interaction in a MoS2
resonator. We achieve the tunability of coupling between these initially
uncoupled modes by using electrostatic gate voltages. This tunable coupling
enables us to make the modes commensurate and observe energy exchange between
the modes. We attribute the strong energy exchange between the vibrational
modes to 2:1 internal resonance. This interaction strongly affects the dynamics
of the modal response of such resonators. We observe peak splitting, a
signature of energy exchange between the modes even when the modal response is
in the linear regime. We model our device to explain the observed effect of
excitation, detuning of modal frequencies, and intermodal coupling strength on
the resonator dynamics. MoS2 resonators explored in this work are ideal for
understanding the rich dynamics offered through the intermodal coupling.",2102.10384v1
2021-03-23,Cross sections of solar neutrino capture by 127I nuclei and Gamow Teller resonances,"Solar neutrino capture cross-section by 127I nucleus has been studied with
taking into account the influence of the resonance structure of the nuclear
strength function S(E). Three types of isobaric resonances: giant Gamow-Teller,
analog resonance and low-lying Gamow-Teller pigmy resonances has been
investigated on the framework of self-consistent theory of finite Fermi
systems. The calculations have been performed considering the resonance
structure of the charge-exchange strength function S(E). We analyze the effect
of each resonance on the energy dependence of the cross-section. It has been
shown that all high-lying resonances should be considered. Neutron emission
process for high energy nuclear excitation leads to formation 126Xe isotope. We
evaluate contribution from various sources of solar neutrinos to the
126Xe/127Xe isotopes ratio formed by energetic neutrinos. 126Xe/127Xe isotope
ratio could be an indicator of high-energy boron neutrinos in the solar
spectrum. We also discuss the uncertainties in the often used Fermi-functions
calculations.",2103.12325v1
2021-03-31,Investigation of multi-step effects for proton inelastic scattering to the $2^{+}_{1}$ state in $^6$He,"Multi-step effects between bound, resonant, and non-resonant states have been
investigated by the continuum-discretized coupled-channels method (CDCC). In
the CDCC, a resonant state is treated as multiple states fragmented in a
resonance energy region, although it is described as a single state in usual
coupled-channel calculations. For such the fragmented resonant states, one-step
and multi-step contributions to the cross sections should be carefully
discussed because the cross sections obtained by the one-step calculation
depend on the number of those states, which corresponds to the size of the
model space. To clarify the role of the multi-step effects, we propose the
one-step calculation without model-space dependence for the fragmented resonant
states. Furthermore, we also discuss the multi-step effects between the ground,
$2^{+}_{1}$ resonant, and non-resonant states in $^6$He for proton inelastic
scattering.",2103.16865v2
2021-05-12,Resonant contributions to inclusive nucleon structure functions from exclusive meson electroproduction data,"Nucleon resonance contributions to the inclusive proton $F_2$ and $F_L$
structure functions are computed from resonance electroexcitation amplitudes in
the mass range up to 1.75 GeV extracted from CLAS exclusive meson
electroproduction data. Taking into account for the first time quantum
interference effects, the resonance contributions are compared with inclusive
proton structure functions evaluated from $(e,e'X)$ cross section data and the
longitudinal to transverse cross section ratio. Contributions from isospin-1/2
and 3/2 resonances remain substantial over the entire range of photon
virtualities $Q^2 \lesssim 4$ GeV$^2$, where their electroexcitation amplitudes
have been obtained, and their $Q^2$ evolution displays pronounced differences
in the first, second and third resonance regions. We compare the structure
functions in the resonance region with those computed from parton distributions
fitted to deep-inelastic scattering data, and extrapolated to the resonance
region, providing new quantitative assessments of quark-hadron duality in
inclusive electron-proton scattering.",2105.05834v1
2021-06-21,Secular resonance of inner test particles in hierarchical planetary systems,"The present work studies the secular resonance associated with the critical
argument $\sigma = \varpi$ ($\varpi$ is the longitude of pericentre) for inner
test particles moving in low-eccentricity region with inclination $i$ smaller
than $39^{\circ}$. To formulate the dynamical model, the double-averaged
Hamiltonian is formulated up to an arbitrary order in the semimajor axis ratio,
and then those high-order periodic terms are removed from the double-averaged
Hamiltonian by means of Hori--Deprit transformation technique. The resulting
Hamiltonian determines a resonant model with a single degree of freedom. Based
on the resonant model, it becomes possible to explore the phase-space
structure, resonant centre, and resonant width in an analytical manner. In
particular, an excellent correspondence is found between the resonant width in
terms of the eccentricity variation and the maximum variation of eccentricity
($\Delta e$) for test particles initially placed on quasi-circular orbits. It
means that the secular dynamics in the low-eccentricity space with $i <
39^{\circ}$ is dominantly governed by the secular resonance associated with
$\sigma = \varpi$.",2106.10794v1
2021-08-06,Mitigating off-resonant error in the cross-resonance gate,"Off-resonant error for a driven quantum system refers to interactions due to
the input drives having non-zero spectral overlap with unwanted system
transitions. For the cross-resonance gate, this includes leakage as well as
off-diagonal computational interactions that lead to bit-flip error on the
control qubit. In this work, we quantify off-resonant error, with more focus on
the less studied off-diagonal control interactions, for a direct CNOT gate
implementation. Our results are based on numerical simulation of the dynamics,
while we demonstrate the connection to time-dependent Schrieffer-Wolff and
Magnus perturbation theories. We present two methods for suppressing such error
terms. First, pulse parameters need to be optimized so that off-resonant
transition frequencies coincide with the local minima due to the pulse spectrum
sidebands. Second, we show the advantage of a $Y$-DRAG pulse on the control
qubit in mitigating off-resonant error. Depending on qubit-qubit detuning, the
proposed methods can improve the average off-resonant error from approximately
$10^{-3}$ closer to the $10^{-4}$ level for a direct CNOT calibration.",2108.03223v1
2021-11-08,Resonance distribution in the quantum random Lorentz gas,"The multiple scattering model of a quantum particle in a random Lorentz gas
consisting of fixed point scatterers is considered in arbitrary dimension. An
efficient method is developed to numerically compute the map of the density of
scattering resonances in the complex plane of the wavenumber without finding
them one by one. The method is applied to two collision models for the
individual scatterers, namely a resonant model, and a non-resonant hard-sphere
model. The results obtained with the former are compared to the literature. In
particular, the spiral arms surrounding the single-scatterer resonance are
identified as proximity resonances. Moreover, the hard-sphere model is used to
reveal previously unknown structures in the resonance density. Finally, it is
shown how Anderson localization affects the distribution of resonance widths,
especially in the one-dimensional case.",2111.04410v3
2021-12-07,Plasmon resonances of nanorods in transverse electromagnetic scattering,"Plasmon resonance is the resonant oscillation of conduction electrons at the
interface between negative and positive permittivity material stimulated by
incident light, which forms the fundamental basis of many cutting-edge
industrial applications. We are concerned with the quantitative theoretical
understanding of this peculiar resonance phenomenon. It is known that the
occurrence of plasmon resonance as well as its quantitative behaviours
critically depend on the geometry of the material structure, the corresponding
material parameters and the operating wave frequency, which are delicately
coupled together. In this paper, we study the plasmon resonance for a 2D
nanorod structure, which presents an anisotropic geometry and arises in the
transverse electromagnetic scattering. We present delicate spectral and
asymptotic analysis to establish the accurate resonant conditions as well as
sharply characterize the quantitative behaviours of the resonant field.",2112.03697v2
2022-01-19,Observation of the P-wave Shape Resonance,"Partial wave resonances are quasi-bound states that are formed by tunneling
through the centrifugal barrier. Such states are important to collisions that
deviate from the Langevin limit where direct collision path is suppressed due
to quantum symmetry or a potential barrier. In such a case, quantum resonances
play a major role in the dynamics at low temperatures where scattering process
can be described mainly by the resonance contribution. Here we present the
first observation of the lowest-lying partial wave resonance in the Penning
ionization collisions between metastable neon and rovibrationally ground state
HD molecules. We observe the resonance at an energy of $k_B\times$22mK taking
advantage of the phase space correlation similar to atomic delta kick cooling.
We show that the $p$-wave resonance position is particularly sensitive to the
leading term of the van der Waals interaction. We also measure shape resonance
at a higher angular momentum state, $l=6$, allowing us to disentangle and probe
the short and the long parts of the intermolecular interaction.",2201.07716v2
2022-03-04,Post-Fabrication Trimming of Silicon Photonic Ring Resonators at Wafer-Scale,"Silicon ring resonator-based devices, such as modulators, detectors, filters,
and switches, play important roles in integrated photonic circuits for optical
communication, high-performance computing, and sensing applications. However,
the high sensitivity to fabrication variations has limited their volume
manufacturability and commercial adoption. Here, we report a low-cost
post-fabrication trimming method to tune the resonance wavelength of a silicon
ring resonator and correct for fabrication variations at wafer-scale. We use a
Ge implant to create an index trimmable section in the ring resonator and an
on-chip heater to apply a precise and localized thermal annealing to tune and
set its resonance to a desired wavelength. We demonstrate resonance wavelength
trimming of ring resonators fabricated across a 300 mm silicon-on-insulator
(SOI) wafer to within +/-32 pm of a target wavelength of 1310 nm, providing a
viable path to high-volume manufacturing and opening up new practical
applications for these devices.",2203.03503v1
2022-03-03,Intelligent resonance tracking of a microwave plasmonic resonator for compact wireless sensors,"Plasmonic sensing has been in the spotlight for decades, the concept and
applications of which have been generalized to spoof surface plasmons (SSPs) in
the microwave band. Here, we report a compact and wireless sensor within a
printed circuit board size of 18 mm * 12 mm, tracking the resonance frequency
shift of a microwave plasmonic resonator via a software-defined scheme. The
microwave plasmonic resonator yields a deep-subwavelength size, enhanced
sensitivity, and a good electromagnetic compatibility performance. The
software-defined resonance tracking scheme minimalizes the hardware circuit and
the consumed spectrum resources, and makes the detection intelligently adaptive
to the target resonance, with a signal-to-noise ratio of 69 dB and a data rate
of 2272 measuring points per second. The sensor has been validated via acetone
vapor concentration sensing, while its applications can be widely extended by
replacing the transducer materials. This approach provides compact, sensitive,
accurate and intelligent solutions for resonant sensors in the Internet of
things (IoT).",2203.04780v1
2022-03-18,Wire metamaterial filled metallic resonators,"In this work we study electromagnetic properties of a resonator recently
suggested for the search of axions - a hypothetical candidate to explain dark
matter. A wire medium loaded resonator (called a plasma haloscope when used to
search for dark matter) consists of a box filled with a dense array of parallel
wires electrically connected to top and bottom walls. We show that the
homogenization model of wire medium works for this resonator without mesoscopic
corrections, and that the resonator quality $Q$ at the frequency of our
interest drops versus the growth of the resonator volume $V$ until it is
dominated by resistive losses in the wires. We find that even at room
temperature metals like copper can give quality factors in the thousands, an
order of magnitude higher than originally assumed. Our theoretical results for
both loaded and unloaded resonator quality factors were confirmed by building
an experimental prototype. We discuss ways to further improve WM loaded
resonators.",2203.10083v2
2022-05-31,Spin-Acoustic Control of Silicon Vacancies in 4H Silicon Carbide,"We demonstrate direct, acoustically mediated spin control of naturally
occurring negatively charged silicon monovacancies (V$_{Si}^-$) in a high
quality factor Lateral Overtone Bulk Acoustic Resonator fabricated out of high
purity semi-insulating 4H-Silicon Carbide. We compare the frequency response of
silicon monovacancies to a radio-frequency magnetic drive via
optically-detected magnetic resonance and the resonator's own radio-frequency
acoustic drive via optically-detected spin acoustic resonance and observe a
narrowing of the spin transition to nearly the linewidth of the driving
acoustic resonance. We show that acoustic driving can be used at room
temperature to induce coherent population oscillations. Spin acoustic resonance
is then leveraged to perform stress metrology of the lateral overtone bulk
acoustic resonator, showing for the first time the stress distribution inside a
bulk acoustic wave resonator. Our work can be applied to the characterization
of high quality-factor micro-electro-mechanical systems and has the potential
to be extended to a mechanically addressable quantum memory.",2205.15488v1
2022-07-27,A Criterion for the Stability of Planets in Chains of Resonances,"Uncovering the formation process that reproduces the distinct properties of
compact super-Earth exoplanet systems is a major goal of planet formation
theory. The most successful model argues that non-resonant systems begin as
resonant chains of planets that later experience a dynamical instability.
However, both the boundary of stability in resonant chains and the mechanism of
the instability itself are poorly understood. Previous work postulated that a
secondary resonance between the fastest libration frequency and a difference in
synodic frequencies destabilizes the system. Here, we use that hypothesis to
produce a simple and general criterion for resonant chain stability that
depends only on planet orbital periods and masses. We show that the criterion
accurately predicts the maximum mass of planets in synthetic resonant chains up
to six planets. More complicated resonant chains produced in population
synthesis simulations are found to be less stable than expected, although our
criterion remains useful and superior to machine learning models.",2207.13833v1
2022-07-29,Coherent resonant transmission,"The reflectionless coherent light transport in the coupled resonator array is
investigated in the presence of intra-resonator intermodal coupling between the
clockwise and counterclockwise modes, which plays a constructive role for
modulating the light flow rather than inducing the unwanted backscattering. The
interplay between the intra-resonator intermodal coupling and the
inter-resonator couplings enables the coherent resonant transmission (CRT) of
the properly superposed injection constituted by the clockwise and
counterclockwise modes. The superposition coefficients of the initial
excitation determine the mode chirality of the resonant transmission.
Sequentially experiencing the time-reversal process of CRT and the CRT realizes
the perfect mode conversion that the mode chirality of the injection wave
switches into the opposite after resonant transmission. Our findings on the
coherent light transport provide insights for the control and manipulation of
light field in the integrated photonics, nanophotonics, chiral optics, and
beyond.",2207.14453v1
2022-09-03,Single photon controlled steady state electron transport through a resonance DQD-Cavity system in a strong coupling regime,"We perform theoretical calculations to study steady-state electron transport
in a double quantum dot, DQD, coupled to a quantized cavity photon field both
in resonance and off-resonance regimes considering weak and strong coupling. In
the resonant strong coupling regime, photon exchanges between the energy states
of the DQD and the cavity are found reflecting multiple Rabi-resonances. The
electron occupation of the states and the transport current can be smoothly
increased by tuning the cavity-environment coupling strength. Making the system
off-resonant, but still in the strong coupling regime, the photon exchange is
diminished and the electron occupation of the system and the transport current
through it are prominent for high cavity-environment coupling strength. In the
weak coupling regime between the DQD and the cavity, the system has almost the
same response in the resonant and the off-resonant regimes at high values of
the cavity-environment coupling strength.",2209.01495v1
2022-11-14,A mathematical design strategy for highly dispersive resonator systems,"Designing devices composed of many small resonators is a challenging problem
that can easily incur significant computational cost. Can asymptotic techniques
be used to overcome this often limiting factor? Integral methods and asymptotic
techniques have been used to derive concise characterisations for scattering by
resonators, but can these be generalised to systems of many dispersive
resonators whose material parameters have highly non-linear frequency
dependence? In this paper, we study halide perovskite resonators as a
demonstrative example. We extend previous work to show how a finite number of
coupled resonators can be modelled concisely in the limit of small radius. We
also show how these results can be used as the basis for an inverse design
strategy, to design resonator systems that resonate at specific frequencies.",2211.07223v1
2022-11-30,Fabrication and Characterization of Magnetic-Field-Resilient MoRe Superconducting Coplanar Waveguide Resonators,"Magnetic-field-resilient superconducting coplanar waveguide (SCPW) resonators
are essential for developing integrated quantum circuits of various qubits and
quantum memory devices. Molybdenum-Rhenium (MoRe), which is a disordered
superconducting alloy forming a highly transparent contact to the graphene and
carbon nanotubes (CNTs), would be a promising platform for realizing the
field-resilient SCPW resonators combined with graphene- and CNT-based
nano-hybrid qubits. We fabricated MoRe SCPW resonators and investigated their
microwave transmission characteristics with varying temperature and external
magnetic field. Our observations show that the thickness of MoRe film is a
critical parameter determining the lower critical field, kinetic inductance,
and characteristic impedance of the SCPW resonator, resulting in drastic
changes in the quality factor and the resonance frequency. As a result, we
obtained a maximum value of $Q_{i} > 10^{4}$ in parallel magnetic fields up to
$B_{||} = 0.15$ T for the 27-nm-thick MoRe resonator. Our experimental results
suggest that MoRe SCPW resonator would be useful for integrating nano-hybrid
spin or gatemon qubits and for developing spin-ensemble quantum memory devices.",2211.16948v1
2023-01-13,Possible interpretation of the complex expectation values associated with resonances,"We propose a possible scheme to interpret the complex expectation values
associated with resonances having the complex eigenenergies. Using the Green's
function for resonances, the expectation value is basically described by the
Breit-Wigner distribution as a function of the real excitation energy. In the
expression of the complex expectation values for resonances, the real part
brings the integral value of the distribution, while the imaginary part
produces the deviation from the Breit-Wigner distribution,which explains a
shift of the peak in the strength from the resonance energy. We apply the
present scheme to the several nuclear resonances of $^{12}$C including the
Hoyle state, and neutron/proton-rich nuclei of $^6$He, $^6$Be, $^8$He, and
$^8$C. In these nuclei, many-body resonances are obtained as the complex-energy
eigenstates under the correct boundary condition using the complex scaling
method, and their nuclear radii are uniquely evaluated. We discuss the peculiar
energy dependence of the strength function of the square radius for the
resonances in these nuclei.",2301.05355v1
2023-03-21,Correlated polarization dependences between surface-enhanced resonant Raman scattering and plasmon resonance elastic scattering showing spectral uncorrelation to each other,"We investigated the origin of the identical polarization angle dependences
between surface-enhanced resonant Raman scattering (SERRS) and plasmon
resonance for two types of single silver nanoparticle aggregates. The first
type (Type I), in which the SERRS spectral envelopes are similar to the plasmon
resonance elastic scattering spectra, shows the identical polarization
dependence between the SERRS and plasmon resonance. The second type (Type II),
in which the SERRS envelopes largely deviate from the plasmon resonance, also
exhibits identical polarization dependence. Scanning electron microscopy (SEM)
observations indicated that these aggregates were dimers. Thus, this
unintuitive result was examined by calculating the electromagnetic (EM)
enhancement by changing the morphology of the dimers. The calculation revealed
that Type I of dimer generates SERRS directly by superradiant plasmons. The
Type II of dimer generates SERRS indirectly by subradiant plasmons, which
receive light energy from the superradiant plasmons. This indirect SERRS
process clarifies that the interaction between the superradiant and subradiant
plasmons results in an identical polarization dependence between SERRS and
plasmon resonance for Type II of dimers.",2303.11608v1
2023-04-20,Control the qubit-qubit coupling in the superconducting circuit with double-resonator couplers,"We propose a scheme of using two fixed frequency resonator couplers to tune
the coupling strength between two Xmon qubits. The induced indirect qubit-qubit
interactions by two resonators could offset with each other, and the direct
coupling between two qubits are not necessarily for switching off. The small
direct qubit-quibt coupling could effectively suppress the frequency interval
between switching off and switching on, and globally suppress the second and
third-order static ZZ couplings. The frequencies differences between resonator
couplers and qubits readout resonators are very large, this might be helpful
for suppressing the qubits readout errors. The cross-kerr resonant processes
between a qubit and two resonators might induce pole and affect the crosstalks
between qubits. The double resonator couplers could unfreeze the restrictions
on capacitances and coupling strengths in the superconducting circuit, and it
can also reduce the flux noises and globally suppress the crosstalks.",2304.10047v2
2023-06-11,Resonant dynamics of extreme mass-ratio inspirals in a perturbed Kerr spacetime,"Extreme mass-ratio inspirals (EMRI) are one of the most sensitive probes of
black hole spacetimes with gravitational wave measurements. In this work, we
systematically analyze the dynamics of an EMRI system near orbital resonances,
assuming the background spacetime is weakly perturbed from Kerr. Using the
action-angle formalism, we have derived an effective resonant Hamiltonian that
describes the dynamics of the resonant degree of freedom, for the case that the
EMRI motion across the resonance regime. This effective resonant Hamiltonian
can also be used to derive the condition that the trajectory enters/exits a
resonant island and the permanent change of action variables across the
resonance with the gravitational wave radiation turned on. The orbital chaos,
on the other hand, generally leads to transitions between different branches of
rotational orbits with finite changes of the action variables. These findings
are demonstrated with numerical orbital evolutions that are mapped into
representations using action-angle variables. This study is one part of the
program of understanding EMRI dynamics in a generic perturbed Kerr spacetime,
which paves the way of using EMRIs to precisely measure the black hole
spacetime.",2306.06576v2
2023-06-16,Revised Hamiltonian near third-integer resonance and implications for transverse resonance island buckets in storage rings,"In storage rings, an accurate description of particle dynamics near
third-integer resonance is crucial for various applications. The conventional
approach is to extrapolate far-resonance dynamics to near-resonance, but
difficulty arises because the nonlinear detuning parameter diverges at this
critical point. Here we derive, via a suitable application of the canonical
perturbation theory, a revised detuning parameter that is well-behaved near
resonance. The resultant theory accurately describes the morphology of
transverse resonance island buckets (TRIBs) for a wide range of parameter
space. Our results have important implications for advanced applications of
storage rings, as well as for the underlying physics of resonant particle
dynamics.",2306.09587v1
2023-06-19,Resonance expansion for quantum walks and its applications to the long-time behavior,"In this paper, resonances are introduced to a class of quantum walks on
$\mathbb{Z}$. Resonances are defined as poles of the meromorphically extended
resolvent of the unitary time evolution operator. In particular, they appear
inside the unit circle. Some analogous properties to those of quantum
resonances for Schr\""odinger operators are shown. Especially, the resonance
expansion, an analogue of the eigenfunction expansion, indicates the long-time
behavior of quantum walks. The decaying rate, the asymptotic probability
distribution, and the weak limit of the probability density are described by
resonances and associated (generalized) resonant states. The generic simplicity
of resonances is also investigated.",2306.10719v1
2023-06-22,High Impedance Josephson Junction Resonators in the Transmission Line Geometry,"In this article we present an experimental study of microwave resonators made
out of Josephson junctions. The junctions are embedded in a transmission line
geometry so that they increase the inductance per length for the line. By
comparing two devices with different input/output coupling strengths, we show
that the coupling capacitors, however, add a significant amount to the total
capacitance of the resonator. This makes the resonators with high coupling
capacitance to act rather as lumped element resonators with inductance from the
junctions and capacitance from the end sections. Based on a circuit analysis,
we show that the input and output couplings of the resonator are limited to a
maximum value of $\omega_r Z_0 /4 Z_r$ where $\omega_r$ is the resonance
frequency and $Z_0$ and $Z_r$ are the characteristic impedances of the
input/output lines and the resonator respectively.",2306.12701v2
2023-09-08,Generative inverse design of multimodal resonant structures for locally resonant metamaterials,"In the development of locally resonant metamaterials, the physical resonator
design is often omitted and replaced by an idealized mass-spring system. This
paper presents a novel approach for designing multimodal resonant structures,
which give rise to multi-bandgap metamaterials with predefined band gaps. Our
method uses a conditional variational autoencoder to identify nontrivial
patterns between design variables of complex-shaped resonators and their modal
effective parameters. After training, the cost of generating designs satisfying
arbitrary criteria - frequency and mass of multiple modes - becomes negligible.
An example of a resonator family with six geometric variables and two targeted
modes is further elaborated. We find that the autoencoder performs well even
when trained with a limited dataset, resulting from a few hundred numerical
modal analyses. The method generates several designs that very closely
approximate the desired modal characteristics. The accuracy of the best
designs, proposed by the auto-encoder, is confirmed in tests of 3D-printed
resonator prototypes. Further experiments demonstrate the close agreement
between the measured and desired dispersion relation of a sample metamaterial
beam.",2309.04177v1
2023-09-12,4th Body-Induced Secondary Resonance Overlapping Inside Unstable Resonant Orbit Families: a Jupiter-Ganymede 4:3 + Europa Case Study,"The overlapping of mean-motion resonances is useful for low or
zero-propellant space mission design, but while most related prior work uses a
planar CRTBP model, tours of multi-moon systems require using resonances
affected by two moons. In this case study, we investigate Jupiter-Ganymede
unstable 4:3 resonant orbits in a concentric circular restricted 4-body
Jupiter-Europa-Ganymede model. We show that despite their high order, secondary
resonances between the 4:3 orbits and Europa have a large effect, including
11/34, 12/37, 23/71, and 25/77. Computing newly generated objects inside the
secondary resonances definitively confirms their overlap, which causes a
complete structural change of the higher-energy unstable 4:3 orbits whose
manifolds are most useful for low-TOF orbit transfers. We believe this
phenomenon is general, with major implications for resonant orbit use in tour
design.",2309.06073v2
2023-09-28,Quantum Resonance viewed as Weak Measurement,"Quantum resonance, i.e., amplification in transition probability available
under certain conditions, offers a powerful means for determining fundamental
quantities in physics, including the time duration of the second adopted in the
SI units and neutron's electric dipole moment which is directly linked to CP
violation. We revisit two of the typical examples, the Rabi resonance and the
Ramsey resonance, and show that both of these represent the weak value
amplification and that near the resonance points they share exactly the same
behavior of transition probabilities except for the measurement strength whose
difference leads to the known advantage of the Ramsey resonance in the
sensitivity. Conversely, as a by-product of the relationship, we may measure
the weak value through quantum resonance. In fact, we argue that previous
measurements of neutron electric dipole moment based on the Ramsey resonance
have potentially determined the weak value of neutron's spin with much higher
precision than the conventional weak value measurement.",2309.16281v2
2023-12-04,In-situ tuning of optomechanical crystals with nano-oxidation,"Optomechanical crystals are a promising device platform for quantum
transduction and sensing. Precise targeting of the optical and acoustic
resonance frequencies of these devices is crucial for future advances on these
fronts. However, fabrication disorder in these wavelength-scale nanoscale
devices typically leads to inhomogeneous resonance frequencies. Here we achieve
in-situ, selective frequency tuning of optical and acoustic resonances in
silicon optomechanical crystals via electric field-induced nano-oxidation using
an atomic-force microscope. Our method can achieve a tuning range >2 nm (0.13%)
for the optical resonance wavelength in the telecom C-band, and >60 MHz (1.2%)
for the acoustic resonance frequency at 5 GHz. The tuning resolution of 1.1 nm
for the optical wavelength, and $150$ kHz for the acoustic frequency allows us
to spectrally align multiple optomechanical crystal resonators using optimal
oxidation patterns determined via an inverse design protocol. Our results
establish a method for precise post-fabrication tuning of optomechancical
crystals. This technique can enable coupled optomechanical resonator arrays,
scalable resonant optomechanical circuits, and frequency matching of
microwave-optical quantum transducers.",2312.02123v1
2023-12-22,Dynamical structures associated with high-order and secondary resonances in the spin-orbit problem,"In our Solar system, spin-orbit resonances are common under Sun--planet,
planet--satellite and binary asteroid configurations. In this work, high-order
and secondary spin-orbit resonances are investigated by taking numerical and
analytical approaches. Poincar\'e sections as well as two types of dynamical
maps are produced, showing that there are complicated structures in the phase
space. To understand numerical structures, we adopt the theory of perturbative
treatments to formulate resonant Hamiltonian for describing spin-orbit
resonances. Results show that there is an excellent agreement between
analytical and numerical structures. It is concluded that the main V-shape
structure arising in the parameter space $(\dot\theta,\alpha)$ is sculpted by
the synchronous primary resonance, those minute structures inside the V-shape
region are dominated by secondary resonances and those structures outside the
V-shape region are governed by high-order resonances. At last, the analytical
approach is applied to binary asteroid systems (65803) Didymos and (4383)
Suruga to reveal their phase-space structures.",2312.14413v1
2012-10-01,The Color Differences of Kuiper Belt Objects in Resonance with Neptune,"(Abridged) New optical colors of 58 objects in mean motion resonances with
Neptune show the various resonant populations have significantly different
color distributions. The 5:3 and 7:4 resonances have semi-major axes near the
middle of the main Kuiper Belt and both are dominated by ultra-red material.
The 5:3 and 7:4 resonances have statistically the same color distribution as
the low inclination ""cold"" classical belt. The inner 4:3 and distant 5:2
resonances have objects with mostly moderately red colors, similar to the
scattered and detached disk populations. The 2:1 resonance, which is near the
outer edge of the main Kuiper Belt, has a large range of colors with similar
numbers of moderately red and ultra-red objects at all inclinations. The inner
3:2 resonance, like the outer 2:1, has a large range of objects from neutral to
ultra-red. The Neptune Trojans (1:1 resonance) are only slightly red, similar
to the Jupiter Trojans. The inner 5:4 resonance only has four objects with
measured colors but shows equal numbers of ultra-red and moderately red
objects. The 9:5, 12:5, 7:3, 3:1 and 11:3 resonances do not have reliable color
distribution statistics, though it appears noteworthy that all three of the
measured 3:1 objects have only moderately red colors, similar to the 4:3 and
5:2 resonances. The different color distributions are likely a result from the
disruption of the primordial Kuiper Belt from the scattering and migration of
the giant planets. The few low inclination objects known in the outer 2:1 and
5:2 resonances are mostly only moderately red. This suggests if the 2:1 and 5:2
have a cold low inclination component, the objects likely had a significantly
different origin than the ultra-red dominated cold components of the cold
classical belt and 5:3 and 7:4 resonances.",1210.0537v1
2016-04-25,Oblique internal-wave chain resonance over seabed corrugations,"We show that monochromatic long-crested corrugations on an otherwise flat
seafloor can coherently scatter the energy of an oblique incident internal wave
to multiple multi-directional higher-mode waves via a series of resonant
interactions. We demonstrate that a resonance between seabed corrugations and a
normally or slightly oblique incident internal wave results in a series of
follow-up resonant interactions, which take place between the same corrugations
and successively resonated shorter waves. A chain resonance of internal waves
that carries energy to small scales is thus obtained, and we find that the
Richardson number decreases by several orders of magnitude over the corrugated
patch. If the incidence angle is large, and the incident wave perfectly
satisfies a resonance condition with the topography, it turns out that not many
higher-mode resonance or near-resonance conditions can be satisfied, such that
energy stays confined within the first few modes. Nevertheless, if the incident
waves are sufficiently detuned from satisfying a perfect resonance condition
with the seabed corrugations, then we show that this frequency detuning may
balance off the large detuning due to oblique incidence, leading to a chain
resonance that again carries energy to small scales. The evolution of the
incident and resonated wave amplitudes is predicted from the envelope equation
for internal waves over resonant seabed topography in a three-dimensional
rotating fluid, which we derive considering the Boussinesq and $f$-plane
approximations with $f$ the Coriolis frequency, linear density stratification
and small-amplitude corrugations. Our results suggest that topographic features
on the ocean floor with a dominant wavenumber vector, through the chain
resonance mechanism elucidated here, may play a more important role than
previously thought in the enhancement of diapycnal mixing and energy
dissipation.",1604.07308v2
2018-10-25,Light-Quark Resonances at COMPASS,"The main goal of the spectroscopy program at COMPASS is to explore the
light-meson spectrum in the mass range below about $2\,\text{GeV}/c^2$ using
diffractive dissociation reactions. Our flagship channel is the production of
three charged pions in the reaction: $\pi^- + p \to \pi^-\pi^-\pi^+ +
p_\text{recoil}$, for which COMPASS has acquired the so far world's largest
dataset of roughly $50\,\text{M}$ exclusive events using an $190\,\text{GeV}/c$
$\pi^-$ beam.
  In order to extract the parameters of the $\pi_J$ and $a_J$ resonances that
appear in the $\pi^-\pi^-\pi^+$ system, we performed the so far most
comprehensive resonance-model fit, using Breit-Wigner parametrizations. This
method in combination with the high statistical precision of our data allows us
to study ground and excited states. We study the $a_4(2040)$ resonance in the
$\rho(770)\pi G$ and $f_2(1270)\pi F$ decays. In addition to the ground state
resonance $a_1(1260)$, we have found evidence for the $a_1(1640)$. We also
study the spectrum of $\pi_2$ states by simultaneously describing four
$J^{PC}=2^{-+}$ waves using three $\pi_2$ resonances, the $\pi_2(1670)$, the
$\pi_2(1880)$, and the $\pi_2(2005)$.
  Using a novel analysis approach, where the resonance-model fit is performed
simultaneously in narrow bins of the squared four-momentum transfer $t'$
between the beam pion and the target proton, allows us to study the $t'$
dependence of resonant and non-resonant components included in our model. We
observe that for most of the partial waves, the non-resonant components show a
steeper $t'$ spectrum compared to the resonances and that the $t'$ spectrum of
most of the resonances becomes shallower with increasing resonance mass. We
also study the $t'$ dependence of the relative phases between resonance
components. The pattern we observe is consistent with a common production
mechanism of these states.",1810.10805v1
1994-01-24,Theory of Spin-Split Cyclotron Resonance in the Extreme Quantum Limit,"We present an interpretation of recent cyclotron resonance experiments on the
two-dimensional electron gas in GaAs/AlGaAs heterostructures. We show that the
observed dependence of the resonance spectrum on Landau level occupancy and
temperature arises from the interplay of three factors: spin-splitting of the
cyclotron frequency; thermal population of the two spin states; and coupling of
the resonances for each spin orientation by Coulomb interactions. In addition,
we derive an $f$-sum rule which allows spin polarisation to be determined
directly from resonance spectra.",9401049v1
1996-09-03,Comment on ``New Class of Resonances at the Edge of the Two-Dimensional Electron Gas.'',"A reproducible resonance structure in the conductance through an
incompressible strip in the quantized Hall regime was recently reported by
Zhitenev {\it et al}. Although the authors disfavored the explanation of the
conductance resonances based on resonant tunneling (RT) through an impurity
state, I believe that it should not be dismissed and can explain a number of
experimental observations very well. In particular, I point out a new
characteristic signature of RT in the quantized Hall regime: the quantization
of the slopes of the resonance tracks on the magnetic field-gate voltage plot.",9609023v1
1998-03-17,Dielectric resonances of binary random networks,"We investigate the AC conductivity of binary random impedance networks, with
emphasis on its dependence on the ratio of the complex conductances of both
phases. We propose an algorithm to determine the conductance of a finite
network, in terms of its poles and of the associated residues. A numerical
implementation of the algorithm, on the example of the square lattice, allows a
detailed investigation of the resonant dielectric response of the binary model,
including the density of resonances, the spectral function, the distribution of
spacings between resonances. The distribution of local electric fields at
resonance is found to be multifractal.",9803209v1
1999-05-04,"Spectroscopy, Interactions and Level Splittings in Au Nanoparticles","We have measured the electronic energy spectra of nm-scale Au particles using
a new tunneling spectroscopy configuration. The particle diameters ranged from
5nm to 9nm, and at low energies the spectrum is discrete, as expected by the
electron-in-a-box model. The density of tunneling resonances increases rapidly
with energy, and at higher energies the resonances overlap forming broad
resonances. Near the Thouless energy, the broad resonances merge into a
continuum. The tunneling resonances display Zeeman splitting in a magnetic
field. Surprisingly, the g-factors (~0.3) of energy levels in Au nano-particles
are much smaller than the g-factor (2.1) in bulk gold.",9905043v1
1999-06-15,Internal Spatiotemporal Stochastic Resonance in a Microscopic Surface Reaction Model,"We show the existence of internal stochastic resonance in a microscopic
stochastic model for the oscillating CO oxidation on single crystal surfaces.
This stochastic resonance arises directly from the elementary reaction steps of
the system without any external input. The lattice gas model is investigated by
means of Monte Carlo simulations. It shows oscillation phenomena and mesoscopic
pattern formation. Stochastic resonance arises once homogeneous nucleation in
the individual surface phases (reconstructed and non-reconstructed) is added.
This nucleation is modelled as a noise process. As a result, synchronization of
the kinetic oscillations is obtained. Internal stochastic resonance may thus be
an internal regulation mechanism of extreme adaptability.",9906215v1
1999-07-08,Semiclassical theory of the emission properties of wave-chaotic resonant cavities,"We develop a perturbation theory for the lifetime and emission intensity for
isolated resonances in asymmetric resonant cavities. The inverse lifetime
$\Gamma$ and the emission intensity $I(\theta)$ in the open system are
expressed in terms of matrix elements of operators evaluated with eigenmodes of
the closed resonator. These matrix elements are calculated in a semiclassical
approximation which allows us to represent $\Gamma$ and $I(\theta)$ as sums
over the contributions of rays which escape the resonator by refraction.",9907109v1
1999-12-02,Nanomechanical vibrating wire resonator for phonon spectroscopy in Helium,"We demonstrate how to build a vibrating wire resonator for phonon excitation
in liquid helium. The resonator is designed as a nanoscopic mechanically
flexible beam machined out of a semiconductor/metal-hybrid. Quenching of the
mechanical resonance around 100 MHz by phonon excitation in liquid ^4He at 4.2
K is shown. First measurements operating the nano-resonator in a dilution of
^3He/^4He at 30 mK are presented.",9912039v1
1999-12-22,Fano Resonances in Electronic Transport through a Single Electron Transistor,"We have observed asymmetric Fano resonances in the conductance of a single
electron transistor resulting from interference between a resonant and a
nonresonant path through the system. The resonant component shows all the
features typical of quantum dots, but the origin of the non-resonant path is
unclear. A unique feature of this experimental system, compared to others that
show Fano line shapes, is that changing the voltages on various gates allows
one to alter the interference between the two paths.",9912419v2
2000-07-16,High frequency resonant experiments in Fe$_8$ molecular clusters,"Precise resonant experiments on Fe$_{8}$ magnetic clusters have been
conducted down to 1.2 K at various tranverse magnetic fields, using a
cylindrical resonator cavity with 40 different frequencies between 37 GHz and
110 GHz. All the observed resonances for both single crystal and oriented
powder, have been fitted by the eigenstates of the hamiltonian ${\cal
H}=-DS_z^2+ES_x^2-g\mu_B{\bf H}\cdot {\bf S}$. We have identified the
resonances corresponding to the coherent quantum oscillations for different
orientations of spin S = 10.",0007265v1
2000-08-23,Impurity induced resonant state in a pseudogap state of a high temperature superconductor,"We predict a resonance impurity state generated by the substitution of one Cu
atom with a nonmagnetic atom, such as Zn, in the pseudogap state of a high-T_c
superconductor. The precise microscopic origin of the pseudogap is not
important for this state to be formed, in particular this resonance will be
present even in the absence of superconducting fluctuations in the normal
state. In the presence of superconducting fluctuations, we predict the
existence of a counterpart impurity peak on a symmetric bias.
  The nature of impurity resonance is similar to the previously studied
resonance in the d-wave superconducting state.",0008349v1
2001-03-16,Dispersoin of the πresonance,"We study the dispersion of the $\pi$ resonance in the superconducting state
within the projected SO(5) model\cite{project}. Away from the the commensurate
momentum, the propagation of the $\pi$ resonance creates phase slips in the
superconducting order parameter. This frustration effect leads to a strong
dressing of the $\pi$ resonance and a downwards dispersion away from the
commensurate wave vector. Based on these results, we argue that the the
commensurate resonance and incommensurate magnetic fluctuations in the cuprates
are continuously connected.",0103363v1
2001-11-29,Resonant control of elastic collisions in an optically trapped Fermi gas of atoms,"We have loaded an ultracold gas of fermionic atoms into a far off resonance
optical dipole trap and precisely controlled the spin composition of the
trapped gas. We have measured a magnetic-field Feshbach resonance between atoms
in the two lowest energy spin-states, |9/2, -9/2> and |9/2, -7/2>. The
resonance peaks at a magnetic field of 201.5 plus or minus 1.4 G and has a
width of 8.0 plus or minus 1.1 G. Using this resonance we have changed the
elastic collision cross section in the gas by nearly 3 orders of magnitude.",0111571v1
2001-12-07,The neutron resonance in the cuprates and its effect on fermionic excitations,"We argue that the exciton scenario for the magnetic resonance in the cuprate
superconductors yields a small spectral weight of the resonance, in agreement
with experiment. We show that the small weight is related to its concentration
in a small region of momentum and energy. Despite this, we find that a large
fermionic self-energy can indeed be generated by a resonance with such
properties, i.e., the scattering from the resonance substantially affects the
electronic properties of the cuprates below $T_c$.",0112126v2
2002-11-14,Electron Spin Polarization in Resonant Interband Tunneling Devices,"We study spin-dependent interband resonant tunneling in double-barrier
InAs/AlSb/ GaMnSb heterostructures. We demonstrate that these structures can be
used as spin filters utilizing spin-selective tunneling of electrons through
the light-hole resonant channel. High densities of the spin polarized electrons
injected into bulk InAs make spin resonant tunneling devices a viable
alternative for injecting spins into a semiconductor. Another striking feature
of the proposed devices is the possibility of inducing additional resonant
channels corresponding to the heavy holes. This can be implemented by
saturating the in-plane magnetization in the quantum well.",0211300v1
2003-03-13,Crossing of two Coulomb-Blockade Resonances,"We investigate theoretically the transport of non--interacting electrons
through an Aharanov--Bohm (AB) interferometer with two quantum dots (QD)
embedded into its arms. In the Coulomb-blockade regime, transport through each
QD proceeds via a single resonance. The resonances are coupled through the arms
of the AB device but may also be coupled directly. In the framework of the
Landauer--Buttiker approach, we present expressions for the scattering matrix
which depend explicitly on the energies of the two resonances and on the AB
phase. We pay particular attention to the crossing of the two resonances.",0303254v1
2003-03-20,Bona fide Stochastic Resonance: A view point from stochastic energetics,"We investigate the resonance type behaviour of an overdamped Brownian
particle in a bistable potential driven by external periodic signal. It has
been shown previously that the input energy pumped into the system by the
external drive shows resonance type behaviour as function of noise strength. We
further extend this idea to study the behaviour as function of frequency of the
external driving force and show the occurrence of similar nonmonotonic
behaviour, which can be ascribed as a signature of bona fide stochastic
resonance. Both weak and strong driving limit has been explored indicating the
occurrence of marginal supra-threshold stochastic resonance in a bistable
potential system.",0303417v1
2003-05-16,Resonant formation of strongly correlated paired states in rotating Bose gases,"We propose increasing the fractional quantum Hall gap of a rapidly rotating
Bose gas by increasing the interatomic interactions via a Feshbach resonance.
The generation of molecules by the resonance causes pair correlations to grow
throughout the system effecting the ground state. By an extension of the usual
Chern-Simons theory, built of composite atoms and molecules, we are able to
account for these resonance effects. We find that the resulting ground state
evolves from a Laughlin wavefunction to a unique paired wavefunction as one
approaches the resonance.",0305399v2
2003-05-18,New Resonances Along with Cyclotron Resonance in Heterostructures,"The usual cyclotron resonance occurs at \omega_c=eB/m*c which is independent
of spin. The new resonances depend on spin. The new resonances occur at
\omega_{c\pm}=(1/2)g_{\pm}eB/m*c where (1/2)g_{\pm}= {\it l}+(1/2)\pm s/(2{\it
l}+1). The energy in the centre of two new frequencies varies as the square
root of the 2-dimensional electrons due to spin excess in the Gaussian model.
The frequencies \omega_{c\pm} are linearly proportional to the magnetic field
except near crossing point where the linear combination of wave functions must
be made.",0305415v1
2003-07-10,Quantum dots as scatterers in electronic transport : interference and correlations,"Conductance through a system consisting of a wire with side-attached quantum
dots is calculated. Such geometry of the device allows to study the coexistence
of quantum interference, electron correlations and their influence on
conductance. We underline the differences between ""classical"" Fano resonance in
which the resonant channel is of single-particle nature and ""many-body"" Fano
resonance with the resonant channel formed by Kondo effect. The influence of
electron-electron interactions on the Fano resonance shape is also analyzed.",0307230v1
2003-08-05,Coherent Resonance in Trapped Bose Condensates,"Coherent resonance is the effect of resonant excitation of nonlinear coherent
modes in trapped Bose condensates. This novel effect is shown to be feasible
for Bose-condensed trapped gases. Conditions for realizing this effect are
derived. A method of stabilizing Bose condensates with attractive interactions
is advanced. The origin of dynamic critical phenomena is elucidated.
Interference effects are studied. The existence of atomic squeezing and
multiparticle coherent entanglement is demonstrated. Coherent resonance is a
generalization of atomic resonance, involving internal states of an individual
atom, to collective states of a multiparticle system.",0308082v1
2003-11-01,Superconducting Qubit Storage and Entanglement with Nanomechanical Resonators,"We describe a quantum computational architecture based on integrating
nanomechanical resonators with Josephson junction phase qubits, with which we
implement single- and multi-qubit operations. The nanomechanical resonator is a
GHz-frequency, high-quality-factor dilatational resonator, coupled to the
Josephson phase through a piezoelectric interaction. This system is analogous
to one or more few-level atoms (the Josephson qubits) in a tunable
electromagnetic cavity (the nanomechanical resonator). Our architecture
combines the best features of solid-state and cavity-QED approaches, and may
make possible multi-qubit processing in a scalable, solid-state environment.",0311007v1
2004-02-18,Decoherence in Josephson Qubits from Junction Resonances,"Although Josephson junction qubits show great promise for quantum computing,
the origin of dominant decoherence mechanisms remains unknown. We report Rabi
oscillations for an improved phase qubit, and show that their coherence
amplitude is significantly degraded by spurious microwave resonators. These
resonators arise from changes in the junction critical current produced by
two-level states in the tunnel barrier. The discovery of these high frequency
resonators impacts the future of all Josephson qubits as well as existing
Josephson technologies. We predict that removing or reducing these resonators
through materials research will improve the coherence of all Josephson qubits.",0402470v1
2004-04-30,Nonequilibrium dynamics and thermodynamics of a degenerate Fermi gas across a Feshbach resonance,"We consider a two-species degenerate Fermi gas coupled by a diatomic Feshbach
resonance. We show that the resulting superfluid can exhibit a form of coherent
BEC-to-BCS oscillations in response to a nonadiabatic change in the system's
parameters, such as for example a sudden shift in the position of the Feshbach
resonance. In the narrow resonance limit, the resulting soliton-like
collisionless dynamics can be calculated analytically. In equilibrium the
thermodynamics can be accurately computed across the full range of BCS-BEC
crossover, with corrections controlled by the ratio of the resonance width to
the Fermi energy.",0404724v1
2004-05-26,Dissociation of ultracold molecules with Feshbach resonances,"Ultracold molecules are associated from an atomic Bose-Einstein condensate by
ramping a magnetic field across a Feshbach resonance. The reverse ramp
dissociates the molecules. The kinetic energy released in the dissociation
process is used to measure the widths of 4 Feshbach resonances in 87Rb. This
method to determine the width works remarkably well for narrow resonances even
in the presence of significant magnetic-field noise. In addition, a
quasi-mono-energetic atomic wave is created by jumping the magnetic field
across the Feshbach resonance.",0405606v2
2004-08-21,High Temperature Universal Properties of Atomic Gases Near Feshbach Resonance with Non-Zero Orbital Angular Momentum,"We show that the high temperature behavior of atomic gases near Feshbach
Resonance with non-zero orbital angular momentum $(\ell >0)$ belong to a
universality class different from that of s-wave resonances. The universal
interaction energy is $2(2\ell +1)$ times larger than that of the s-wave when
approaching the resonance from the atomic side, but is essentially zero on the
molecular side; contrary to s-wave resonances where interaction energies on
both sides are the same except for a sign change. The measurement of these
universality properties should be feasible in current experiments.",0408469v1
2005-01-06,Resonator design for surface electron lifetime studies using scanning tunneling spectroscopy,"We derive expressions for the lossy boundary-scattering contribution to the
linewidth of surface electronic states confined with atomic corrals and island
resonators. Correcting experimentally measured linewidths for these
contributions along with thermal and intrumental broadening enables intrinsic
many-body lifetimes due to electron-electron and electron-phonon scattering to
be determined. In small resonators lossy-scattering dominates linewidths whilst
different scaling of widths and separations cause levels to merge in large
resonators. Our results enable the design of resonators suitable for lifetime
studies.",0501102v1
2005-12-21,Resonant activation in a nonadiabatically driven optical lattice,"We demonstrate the phenomenon of resonant activation in a non-adiabatically
driven dissipative optical lattice with broken time-symmetry. The resonant
activation results in a resonance as function of the driving frequency in the
current of atoms through the periodic potential. We demonstrate that the
resonance is produced by the interplay between deterministic driving and
fluctuations, and we also show that by changing the frequency of the driving it
is possible to control the direction of the diffusion.",0512552v1
2006-01-09,Relaxation of the molecular state in atomic Fermi gases near a Feshbach resonance,"The relaxation processes in an ultra-cold degenerate atomic Fermi gas near a
Feshbach resonance are considered. It is shown that the relaxation rate of the
molecules being in a resonance with the atomic Fermi system is of the order of
the part of the chemical potential determined by the interaction between
resonance molecules. In this connection the lower part of the excitation
spectrum in the system of resonance molecules is not well-defined.",0601140v2
2006-06-21,Signal Amplification in NbN Superconducting Resonators via Stochastic Resonance,"We exploit nonlinearity in NbN superconducting stripline resonators, which is
originated by local thermal instability, for studying stochastic resonance. As
the resonators are driven into instability, small amplitude modulated (AM)
microwave signals are amplified with the aid of injected white noise. The
dependence of the signal amplification on the modulation amplitude and the
modulation frequency is examined and compared with theory.",0606555v1
2006-07-25,Escape rate of metastable states in a driven NbN superconducting microwave resonator,"We study thermal instability and formation of local hot spots in a driven
nonlinear NbN superconducting microwave resonator. White noise injected into
the resonator results in transitions between the metastable states via a
process consisting of two stages. In the first stage, the input noise entering
the system induces fluctuations in the resonator mode. While, in the second
one, these mode fluctuations result in phase transitions of the hot spot due to
induced temperature fluctuations. The associated noise-activated escape rate is
calculated theoretically, and also measured experimentally by means of driving
the system into stochastic resonance. A comparison between theory and
experiment yields a partial agreement.",0607628v1
2006-10-13,Figure of Merit of one-dimensional resonant transmission systems in the quantum regime,"The figure of merit, ZT, for a one-dimensional conductor displaying a
Lorentzian resonant transmission probability is calculated. The optimum working
conditions for largest ZT values are determined. It is found that, the
resonance energy has to be adjusted to be several resonance widths away from
the Fermi level. Similarly it is better for the temperature to be equal to
several resonance widths. The approximate relationships, which can be a fairly
good guide for designing devices, between different parameters under optimum
working conditions are given.",0610368v1
2007-03-08,High-Frequency Nanofluidics: An Experimental Study using Nanomechanical Resonators,"Here we apply nanomechanical resonators to the study of oscillatory fluid
dynamics. A high-resonance-frequency nanomechanical resonator generates a
rapidly oscillating flow in a surrounding gaseous environment; the nature of
the flow is studied through the flow-resonator interaction. Over the broad
frequency and pressure range explored, we observe signs of a transition from
Newtonian to non-Newtonian flow at $\omega\tau\approx 1$, where $\tau$ is a
properly defined fluid relaxation time. The obtained experimental data appears
to be in close quantitative agreement with a theory that predicts purely
elastic fluid response as $\omega\tau\to \infty$.",0703230v2
1999-05-17,Parametric resonant acceleration of particles by gravitational waves,"We study the resonant interaction of charged particles with a gravitational
wave propagating in the non-empty interstellar space in the presence of a
uniform magnetic field. It is found that this interaction can be cast in the
form of a parametric resonance problem which, besides the main resonance,
allows for the existence of many secondary ones. Each of them is associated
with a non-zero resonant width, depending on the amplitude of the wave and the
energy density of the interstellar plasma. Numerical estimates of the
particles' energisation and the ensuing damping of the wave are given.",9905054v1
1998-08-21,Electroproduction of the Delta Resonance at High Momentum Transfer,"We studied the electroproduction of the Delta(1232) resonance via the
reaction p(e,e'p)\pi0 at four-momentum transfers Qsq = 2.8 and 4.0 GeV^2. This
is the highest Qsq for which exclusive resonance electroproduction has ever
been observed. Decay angular distributions for Delta to p-pi0$ were measured
over a wide range of barycentric energies covering the resonance. The
$N-\Delta$ transition form factor G*_M and ratios of resonant multipoles
E{1+}/M{1+} and S{1+}/M{1+} were extracted from the decay angular
distributions. These ratios remain small, indicating that perturbative QCD is
not applicable for this reaction at these momentum transfers.",9808024v1
1993-01-06,Neutrinos with Mixing in Twisting Magnetic Fields,"Transitions in a system of neutrinos with vacuum mixing and magnetic moments,
propagating in matter and transverse magnetic field, are considered. It is
shown that in the realistic case of magnetic field direction varying along the
neutrino path qualitatively new phenomena become possible: permutation of
neutrino conversion resonances, appearance of resonances in the
neutrino-antineutrino ($\nu_{lL}\leftrightarrow\bar{\nu}_{lR}$) transition
channels, neutrino-antineutrino resonant conversion, large amplitude
$\nu_{lL}\leftrightarrow\bar{\nu}_{lR}$ oscillations, merging of different
resonances (triple resonances). Possible phenomenological implications of these
effects are briefly discussed.",9301211v1
1997-06-23,QCD Laplace Sum Rules and the $Π(1300)$ Resonance,"A global fit to the shape of the first QCD Laplace sum rule exhibiting
sensitivity to pion-resonance [$\Pi (1300)$] parameters is performed, leading
to predictions for the pion-resonance mass and decay constant. This fit leads
to predictions of $M_{\pi} = 1.15 \pm 0.15 GeV$ for the pion-resonance mass,
and $F_\pi^2=(4.5\pm 2.1).(f_\pi^2m_\pi^4/M_\pi^4)$ for the pion-resonance
decay constant.",9706473v1
1998-07-21,The 1.4 GeV J^PC = 1^-+ state as an interference of a non-resonant background and a resonance at 1.6 GeV,"We investigate theoretical interpretations of the 1.4 GeV J^PC exotic
resonance reported by the E852 collaboration. A K-matrix analysis shows that
the 1.4 GeV enhancement in the E852 eta pi data can be understood as an
interference of a non-resonant Deck-type background and a resonance at 1.6 GeV.",9807433v2
1999-07-20,Parametric resonance in neutrino oscillations in matter,"Neutrino oscillations in matter can exhibit a specific resonance enhancement
-- parametric resonance, which is different from the MSW resonance.
Oscillations of atmospheric and solar neutrinos inside the earth can undergo
parametric enhancement when neutrino trajectories cross the core of the earth.
In this paper we review the parametric resonance of neutrino oscillations in
matter. In particular, physical interpretation of the effect and the prospects
of its experimental observation in oscillations of solar and atmospheric
neutrinos in the earth are discussed.",9907435v1
2001-11-12,Chiral Perturbation Theory and the f2(1270) resonance,"Within Chiral Perturbation Theory, we study elastic pion scattering in the
I=0, J=2, channel, whose main features are the f2(1270) resonance and the
vanishing of the lowest order. By means of a chiral model that includes an
explicit resonance coupled to pions, we describe the data and calculate the
resonance contribution to the O(p^4) and O(p^6) chiral parameters. We also
generalize the Inverse Amplitude Method to higher orders, which allows us to
study channels with vanishing lowest order. In particular, we apply it to the
I=0,J=2 case, finding a good description of the f2(1270) resonance, as a pole
in the second Riemann sheet.",0111140v1
2001-12-19,Resonances from a Hadronic Fireball,"Production of $\phi(1020), \Lambda^*(1520)$ and $\bar{K^*}(892)$ resonances
at the final stage of a heavy-ion collision is considered. It is shown that
original momentum distributions and abundance of resonances formed during the
process of heavy ion collision may differ significantly from their measured
spectra and yields. Reconstruction probability of resonances decaying inside
the fireball can be strongly suppressed because of interactions of their
hadronic decay products in the fireball medium. We investigate dependence of
the degree of the suppression on the fireball size, dynamics, and the resonance
decay width in medium. Quantitative results are presented for lead-lead
collisions at 158 GeV SPS beam energy.",0112252v1
2002-05-13,The Behavior of Form Factors of Nucleon Resonances and Quark-Hadron Duality,"A behavior of the nucleon structure functions in the resonance region is
investigated. Expressions for resonance production form factors, dependent on
photon virtuality $Q^2$, which have correct threshold behavior and take into
account available data on resonance decays, are obtained. Contributions of
resonances to nucleon structure functions are calculated. Obtained expressions
are used to investigate the quark-hadron duality in the electron-nucleon
scattering processes with the structure function $F_2$ as an example.",0205130v1
2003-04-17,How to parameterize a light and broad resonance (the $σ$ meson),"We point out that a commonly used parameterization form to describe the
$\sigma$ resonance is problematic by introducing a spurious singularity below
two particle threshold, on the second sheet. The spurious singularity violates
chiral symmetry and leads to sizable contribution when the resonance is light
and broad -- as what happens to the $\sigma$ resonance, hence must be removed.",0304173v2
2004-11-24,The Use of the Scattering Phase Shift in Resonance Physics,"The scattering phase shift encodes a good amount of physical information
which can be used to study resonances from scattering data. Among others, it
can be used to calculate the continuum density of states and the collision time
in a resonant process. Whereas the first information can be employed to examine
the evolution of unstable states directly from scattering data, the second one
serves as a tool to detect resonances and their properties. We demonstrate both
methods concentrating in the latter case on 'exotic' resonances in pi-pi and
pi-K scattering.",0411317v2
2005-10-04,One-loop Renormalization of Resonance Chiral Theory: Scalar and Pseudoscalar Resonances,"We consider the Resonance Chiral Theory with one multiplet of scalar and
pseudoscalar resonances, up to bilinear couplings in the resonance fields, and
evaluate its beta-function at one-loop with the use of the background field
method. Thus we also provide the full set of operators that renormalize the
theory at one loop and render it finite.",0510041v1
2005-10-05,One-loop Renormalization of Resonance Chiral Theory with Scalar and Pseudoscalar Resonances,"The divergent part of the generating functional of the Resonance Chiral
Theory is evaluated up to one loop when one multiplet of scalar an pseudoscalar
resonances are included and interaction terms which couple up to two resonances
are considered. Hence we obtain the renormalization of the couplings of the
initial Lagrangian and, moreover, the complete list of operators that make this
theory finite, at this order.",0510056v1
1992-11-02,RG flows and resonance scattering amplitudes,"We review recent progresses in the study of factorized resonance scattering
S-matrices. The resonance amplitudes are introduced through a suitable
analytical continuation of the ADE Toda S-matrices. By using the thermodynamic
Bethe ansatz approach we are able to compute the ground state energy, which
describes a rich pattern of flows interpolating between the central charges of
the coset models based on the ADE Lie algebras. We also present the simplest
resonance ``$\phi^3$'' scattering model and discuss its relation with new flows
in non-unitary minimal models. Further generalizations are discussed in terms
of certain asymptotic conditions in a family of ``resonance'' functional
hierarchies.",9211010v1
2002-06-23,Review of Mathematical Techniques Applicable in Astrophysical Reaction Rate Theory,"An overview is presented on statistical techniques for the analytic
evaluation of integrals for non-resonant, non-resonant depleted, non-resonant
cut-off, non-resonant sccreened, and resonant thermonuclear reaction rates. The
techniques are based on statistical distribution theory and the theory of
Meijer's G-function and Fox's H-function. The implementation of Meijer's
G-function in Mathematica constituts an additional utility for analytic
manipulations and numerical computation of thermonuclear reaction rate
integrals. Recent results in the astrophysical literature related to the use of
analytic thermonuclear reaction rates are incorporated.",0206239v1
2003-05-09,Hamilton-Jacobi method for a simple resonance,"It is well known that a generic small perturbation of a Liouville-integrable
Hamiltonian system causes breakup of resonant and near-resonant invariant tori.
A general approach to the simple resonance case in the convex real-analytic
setting is developed, based on a new technique for solving the Hamilton-Jacobi
equation. It is shown that a generic perturbation creates in the core of a
resonance a partially hyperbolic lower-dimensional invariant torus, whose
Lagrangian stable and unstable manifolds, described as global solutions of the
Hamilton-Jacobi equation, split away from this torus at exponentially small
angles. Optimal upper bounds with best constants are obtained for exponentially
small splitting in the general case.",0305143v1
2005-11-07,Resonance Gyrons and Quantum Geometry,"We describe irreducible representations, coherent states and star-products
for algebras of integrals of motions (symmetries) of two-dimensional resonance
oscillators. We demonstrate how the quantum geometry (quantum K\""ahler form,
metric, quantum Ricci form, quantum reproducing measure) arises in this
problem. We specifically study the distinction between the isotropic resonance
$1:1$ and the general $l:m$ resonance for arbitrary coprime $l,m$. Quantum
gyron is a dynamical system in the resonance algebra. We derive its Hamiltonian
in irreducible representations and calculate the semiclassical asymptotics of
the gyron spectrum via the quantum geometrical objects.",0511161v1
2001-09-21,On the resonances of the Laplacian on waveguides,"The resonances for the Dirichlet and Neumann Laplacian are studied on
compactly perturbed waveguides. An upper bound on the number of resonances near
the physical plane is proven. In the absence of resonances, an upper bound is
proven for the localised resolvent. This is then used to prove that the
existence of a quasimode whose asymptotics is bounded away from the thresholds
implies the existence of resonances converging to the real axis.",0109022v1
2000-05-29,Coherence resonance near blowout bifurcation in nonlinear dynamical systems,"Previous studies have shown that noise can induce coherence resonance in some
nonlinear dynamical systems close to a bifurcation of a periodic motion, such
as in excitable systems. We demonstrate that coherence resonance can be
observed in systems close to a {\sl blowout bifurcation}. It is shown that for
dynamical systems with an invariant subspace in which there is a phase-coherent
chaotic attractor, the interplay among the oscillation of local transverse
stability, noise and nonlinearity can lead to coherence resonance phenomenon.
The mechanism of coherence resonance in this type of system is different from
that in previously studied systems.",0005060v1
2003-01-28,Quantization of Classical Maps with tunable Ruelle-Pollicott Resonances,"We investigate the correspondence between the decay of correlation in
classical system, governed by Ruelle--Pollicott resonances, and the properties
of the corresponding quantum system. For this purpose we construct classical
systems with controllable resonances together with their quantum counterpart.
As an application of such tailormade resonances we reveal the role of
Ruelle--Pollicott resonances for the localization properties of quantum energy
eigenstates.",0301041v2
2004-09-06,Resonance Patterns in a Stadium-shaped Microcavity,"We investigate resonance patterns in a stadium-shaped microcavity around
$n_ck R \simeq 10$, where $n_c$ is the refractive index, $k$ the vacuum
wavenumber, and $R$ the radius of the circular part of the cavity. We find that
the patterns of high $Q$ resonances can be classified, even though the
classical dynamics of the stadium system is chaotic. The patterns of the high
$Q$ resonances are consistent with the ray dynamical consideration, and appears
as the stationary lasing modes with low pumping rate in the nonlinear dynamical
model. All resonance patterns are presented in a finite range of $kR$.",0409011v1
2004-09-10,Resonant light scattering by optical solitons,"We consider the process of light scattering by optical solitons in a planar
waveguide with homogeneous and inhomogeneous refractive index core. We observe
resonant reflection (Fano resonances) as well as resonant transmission of light
by optical solitons. All resonant effects can be controlled in experiment by
changing the soliton intensity.",0409023v2
2005-10-12,Resonant light-light interaction in slab waveguides: angular filters and spectral hole burning,"We consider the process of low-power light scattering by optical solitons in
a slab waveguide with homogeneous and inhomogeneous refractive index core. We
observe resonant reflection (Fano resonance) as well as resonant transmission
of light by optical solitons at certain incident angles. The resonance position
can be controlled experimentally by changing the soliton intensity and the
relative frequency detuning between the soliton and the probe light beams.",0510023v1
1996-08-29,Coherent eta photoproduction on the deuteron in the $S_{11}$ resonance region,"Coherent eta photoproduction on the deuteron is studied in the $S_{11}$
resonance region neglecting eta rescattering and two-body processes. For the
elementary reaction on the nucleon, we have considered the dominant
$S_{11}(1535)$ resonance and as background the nucleon pole terms as well as
$\rho$ and $\omega$ meson exchange. We have studied the influence of different
choices for the neutron resonance amplitude, different prescriptions for fixing
the invariant mass of the resonance amplitude and different methods for
deriving the elementary production amplitude for an arbitrary reference frame.",9608064v1
1997-11-26,Multiphonon Giant Resonances,"A new class of giant resonances in nuclei is discussed, i.e., giant
resonances built on other giant resonances. These resonances are observed with
very large cross sections in relativistic heavy ion collisions. A great
experimental and theoretical effort is underway to understand the reaction
mechanism which leads to the excitation of these states in nuclei, as well as
the better microscopic understanding of their properties, e.g., strength,
energy centroids, widths, and anharmonicities.",9711057v1
1998-10-09,Rescattering effects in coherent eta-photoproduction on the deuteron,"Rescattering effects in coherent eta photoproduction on the deuteron are
studied in the region of the S_11(1535) resonance. For the elementary reaction
mechanism on the nucleon, an effective isobar model with inclusion of
resonances and Born terms is used. The resonance parameters are fixed by
considering pion photoproduction only. For the coherent eta production on the
deuteron we have considered the impulse approximation taking into account the
P_11(1440), D_13(1520), and S_11(1535) resonances, rescattering, and meson
exchange currents. For the rescattering mechanism a coupled channel model
including the dominant S_11(1535) resonance is used.",9810027v1
2000-05-16,Algebraic Model for scattering of three-s-cluster systems. II. Resonances in the three-cluster continuum of 6He and 6Be,"The resonance states embedded in the three-cluster continuum of 6He and 6Be
are obtained in the Algebraic Version of the Resonating Group Method. The model
accounts for a correct treatment of the Pauli principle. It also provides the
correct three-cluster continuum boundary conditions by using a Hyperspherical
Harmonics basis. The model reproduces the observed resonances well and achieves
good agreement with other models. A better understanding for the process of
formation and decay of the resonance states in six-nucleon systems is obtained.",0005047v1
2000-09-02,Quantum corrections for pion correlations involving resonance decays,"A method is presented to include quantum corrections into the calculation of
two-pion correlations for the case where particles originate from resonance
decays. The technique uses classical information regarding the space-time
points at which resonances are created. By evaluating a simple thermal model,
the method is compared to semiclassical techniques that assume exponential
decaying resonances moving along classical trajectories. Significant
improvements are noted when the resonance widths are broad as compared to the
temperature.",0009003v2
2001-07-09,Toroidal dipole resonances in the relativistic random phase approximation,"The isoscalar toroidal dipole strength distributions in spherical nuclei are
calculated in the framework of a fully consistent relativistic random phase
approximation. It is suggested that the recently observed ""low-lying component
of the isoscalar dipole mode"" might in fact correspond to the toroidal giant
dipole resonance. Although predicted by several theoretical models, the
existence of toroidal resonances has not yet been confirmed in experiment. The
strong mixing between the toroidal resonance and the dipole compression mode
might help to explain the large discrepancy between theory and experiment on
the position of isoscalar giant dipole resonances.",0107024v2
2002-02-14,Dilepton decays of baryon resonances,"Dalitz decay of baryon resonances is studied and expressions for the decay
width are derived for resonances with arbitrary spin and parity. Contributions
of the various terms in the transition matrix element are compared and
relevance of spin-parity and the resonance mass is discussed. Explicite
algebraic expressions are cited for spin$\le$5/2 resonances. The results can be
used in models of dielectron production in elementary reactions and heavy ion
collisions.",0202047v1
2002-10-02,Shell model in the complex energy plane and two-particle resonances,"An implementation of the shell-model to the complex energy plane is
presented. The representation used in the method consists of bound
single-particle states, Gamow resonances and scattering waves on the complex
energy plane. Two-particle resonances are evaluated and their structure in
terms of the single-particle degreees of freedom are analysed. It is found that
two-particle resonances are mainly built upon bound states and Gamow
resonances, but the contribution of the scattering states is also important.",0210006v1
2003-07-01,Complex scaling of the hyper-spheric coordinates and Faddeev equations,"We implement complex scaling of Faddeev equations using hyper-spheric
coordinates and adiabatic expansion. Complex scaling of coordinates allows
convenient calculations of three-body resonances. We derive the necessary
equations and investigate the adiabatic spectrum at large distances. We
illustrate the viability of the implementation by calculations of several
three-body resonances: a $0^+$ resonance in a model benchmark system of three
identical bosons; the $2^+$ resonance in the $^6$He nucleus within the
$\alpha+n+n$ model; and the two $0^+$ resonances in $^{12}$C within the
three-$\alpha$ model.",0307006v1
2003-10-24,Balance functions in a thermal model with resonances,"The pi+ pi- balance function in rapidity is computed in a thermal model with
resonances. It is found that the correlations from the neutral-resonance decays
are important, yielding about a half of the total contribution, which in
general consist of resonance and non-resonance parts. The model yields the
pionic balance function a few per cent wider that what follows from the recent
data for the Au+Au collisions at 130GeV.",0310062v2
2004-10-25,Hadron resonance probes of QGP,"We discuss the indirect and direct role of the short-lived resonances as
probes of QGP freeze-out process. The indirect effect is the distortion of
stable single particle yields and spectra by contributions of decaying
resonances, which alter significantly the parameters obtained in fits to
experimental data. We than discuss the direct observation of short-lived
resonances as a probe of post-hadronization dynamics allowing to distinguish
between different hadronization models.",0410101v1
2006-10-17,Roper + Pion decays as a test of the radial resonances wavefunction,"We calculate the decays of baryon resonances to the pion + Roper resonance
channel in the frame of the flux-tube breaking model. The baryon and meson
wavefunctions we use are obtained from a linear confinement semi-relativistic
constituent quark model. The results, in good agreement with the existing data,
provide a spectrum independant test on the radial form of the main component of
the Roper resonance. They shed light on a likely orbital nature for the second
delta resonance.",0610065v1
2006-10-27,Hadronic Decays and Baryon Structure,"Relativistic constituent quark models generally describe three-quark systems
with particular interactions. The corresponding invariant mass eigenvalue
spectra and pertinent eigenstates should exhibit the multiplet structure
anticipated for baryon resonances. Taking into account the flavour content,
spin structure, and spatial distribution of the baryon wave functions together
with mass relations of the eigenvalues and decay properties of the eigenstates,
we can link the theoretical mass eigenstates with the experimentally measured
resonances. The resulting classification of baryon resonances differs in some
respects from the one suggested by the Particle Data Group. With regard to the
hadronic decay widths of light and strange baryon resonances a consistent
picture emerges only, if the classification includes two-star resonances.",0610111v1
2002-05-08,Rotational Feshbach Resonances in Ultracold Molecular Collisions,"In collisions at ultralow temperatures, molecules will possess Feshbach
resonances, foreign to ultracold atoms, whose virtual excited states consist of
rotations of the molecules. We estimate the mean spacing and mean widths of
these resonant states, exploiting the fact the molecular collisions at low
energy display chaotic motion. As examples, we consider the experimentally
relevant molecules O_2, OH, and PbO. The density of s-wave resonant states for
these species is quite high, implying that a large number of narrow resonant
states will exist.",0205020v1
2003-10-24,Multiplet Structure of Feshbach Resonances in non-zero partial waves,"We report a unique feature of magnetic field Feshbach resonances in which
atoms collide with non-zero orbital angular momentum. P-wave ($l=1$) Feshbach
resonances are split into two components depending on the magnitude of the
resonant state's projection of orbital angular momentum onto the field axis.
This splitting is due to the magnetic dipole-dipole interaction between the
atoms and it offers a means to tune anisotropic interactions of an ultra-cold
gas of atoms. A parameterization of the resonance in terms of an effective
range expansion is given.",0310121v1
2005-02-04,Strong optical force induced by morphology dependent resonances,"We consider the resonant optical force acting on a pair of transparent
microspheres by the excitation of the Morphology Dependent Resonance (MDR). The
bonding and anti-bonding modes of the MDR correspond to strong attractions and
repulsions respectively. The dependence of the force on separation and the role
of absorption are discussed. At resonance, the force can be enhanced by orders
of magnitude so that it will dominate over other relevant forces. We find that
a stable binding configuration can be induced by the resonant optical force.",0502020v1
2005-09-30,Classification of electromagnetic resonances in finite inhomogeneous three-dimensional structures,"We present a simple and unified classification of macroscopic electromagnetic
resonances in finite arbitrarily inhomogeneous isotropic dielectric 3D
structures situated in free space. By observing the complex-plane dynamics of
the spatial spectrum of the volume integral operator as a function of angular
frequency and constitutive parameters we identify and generalize all the usual
resonances, including complex plasmons, real laser resonances in media with
gain, and real quasi-static resonances in media with negative permittivity and
gain.",0509259v1
2006-07-13,Resonant transparency of materials with negative permittivity,"It is shown that the transparency of opaque material with negative
permittivity exhibits resonant behavior. The resonance occurs as a result of
the excitation of the surface waves at slab boundaries. Dramatic field
amplification of the incident evanescent fields at the resonance improves the
resolution of the the sub-wavelength imaging system (superlens). A finite
thickness slab can be totally transparent to a \textit{p}-polarized obliquely
incident electromagnetic wave for certain values of the incidence angle and
wave frequency corresponding to the excitation of the surface modes. At the
resonance, two evanescent waves have a finite phase shift providing non-zero
energy flux through the non-transparent region.",0607130v1
2006-09-01,Simple Theoretical Models for Resonant Cold Atom Interactions,"Magnetically tunable scattering resonances have been used with great success
for precise control of s-wave scattering lengths in ultracold atomic
collisions. We describe relatively simple yet quite powerful analytic
treatments of such resonances based on the analytic properties of the van der
Waals long range potential. This theory can be used to characterize a number of
properties of specific resonances that have been used successfully in various
experiments with $^{87}$Rb, $^{85}$Rb, $^{40}$K, and $^{6}$Li. Optical Feshbach
resonances are also possible and may be practical with narrow intercombination
line photoassociative transitions in species like Sr and Yb.",0609013v1
1999-04-29,Quantum Computation as a Dynamical Process,"In this paper, we discuss the dynamical issues of quantum computation. We
demonstrate that fast wave function oscillations can affect the performance of
Shor's quantum algorithm by destroying required quantum interference. We also
show that this destructive effect can be routinely avoided by using
resonant-pulse techniques. We discuss the dynamics of resonant pulse
implementations of quantum logic gates in Ising spin systems. We also discuss
the influence of non-resonant excitations. We calculate the range of parameters
where undesirable non-resonant effects can be minimized. Finally, we describe
the ``$2\pi k$-method'' which avoids the detrimental deflection of non-resonant
qubits.",9904105v1
2000-05-19,Resonant radiative processes,"The frequency correlation properties of the radiation from an atom in a
strong field in resonance with neighboring transitions are considered. It is
shown that the difference in frequency correlation in two-photon and stepwise
processes decreases with increase of the external field. The spectral
compositions of the Doppler-broadened resonance scattering and fluorescence are
analyzed. It is shown that in these cases the Doppler line width is
anisotropic.",0005081v1
2001-02-11,Interference of resonances and the double-pole of the S-matrix in a double well system,"We discuss the interaction between two resonant states in a quantum
double-well structure. The behaviour of the resonant states depends on the
coupling between the wells, i.e. the height and width of the barrier that
separates them. We distinguish a region with resonant tunneling and a region
where the two resonances repel each other. The transition between the two
regions is marked by a double pole of the S-matrix.",0102057v1
2001-11-29,Field quantization for chaotic resonators with overlapping modes,"Feshbach's projector technique is employed to quantize the electromagnetic
field in optical resonators with an arbitray number of escape channels. We find
spectrally overlapping resonator modes coupled due to the damping and noise
inflicted by the external radiation field. For wave chaotic resonators the mode
dynamics is determined by a non--Hermitean random matrix. Upon including an
amplifying medium, our dynamics of open-resonator modes may serve as a starting
point for a quantum theory of random lasing.",0111156v2
2002-08-02,Trapping and cooling single atoms with far-off resonance intracavity doughnut modes,"We investigate cooling and trapping of single atoms inside an optical cavity
using a quasi-resonant field and a far-off resonant mode of the Laguerre-Gauss
type. The far-off resonant doughnut mode provides an efficient trapping in the
case when it shifts the atomic internal ground and excited state in the same
way, which is particularly useful for quantum information applications of
cavity quantum electrodynamics (QED) systems. Long trapping times can be
achieved, as shown by full 3-D simulations of the quasi-classical motion inside
the resonator.",0208016v2
2003-09-02,Quantum statistics of overlapping modes in open resonators,"We study the quantum dynamics of optical fields in weakly confining
resonators with overlapping modes. Employing a recently developed quantization
scheme involving a discrete set of resonator modes and continua of external
modes we derive Langevin equations and a master equation for the resonator
modes. Langevin dynamics and the master equation are proved to be equivalent in
the Markovian limit. Our open-resonator dynamics may be used as a starting
point for a quantum theory of random lasers.",0309028v2
2005-01-01,Tunable Whispering Gallery Mode Resonators for Cavity Quantum Electrodynamics,"We theoretically study the properties of highly prolate shaped dielectric
microresonators. Such resonators sustain whispering gallery modes that exhibit
two spatially well separated regions with enhanced field strength. The field
per photon on the resonator surface is significantly higher than e.g. for
equatorial whispering gallery modes in microsphere resonators with a comparable
mode volume. At the same time, the frequency spacing of these modes is much
more favorable, so that a tuning range of several free spectral ranges should
be attainable. We discuss the possible application of such resonators for
cavity quantum electrodynamics experiments with neutral atoms and reveal
distinct advantages with respect to existing concepts.",0501002v1
2006-05-01,Nonlinear coupling of nano mechanical resonators to Josephson quantum circuits,"We propose a technique to couple the position operator of a nano mechanical
resonator to a SQUID device by modulating its magnetic flux bias. By tuning the
magnetic field properly, either linear or quadratic couplings can be realized,
with a discretely adjustable coupling strength. This provides a way to realize
coherent nonlinear effects in a nano mechanical resonator by coupling it to a
Josephson quantum circuit. As an example, we show how squeezing of the nano
mechanical resonator state can be realized with this technique. We also propose
a simple method to measure the uncertainty in the position of the nano
mechanical resonator without quantum state tomography.",0605017v1
2006-06-23,Effective resonant transitions in quantum optical systems: kinematic and dynamic resonances,"We show that quantum optical systems preserving the total number of
excitations admit a simple classification of possible resonant transitions
(including effective), which can be classified by analizying the free
Hamiltonian and the corresponding integrals of motion. Quantum systems not
preserving the total number of excitations do not admit such a simple
classification, so that an explicit form of the effective Hamiltonian is needed
to specify the allowed resonances. The structure of the resonant transitions
essentially depends on the algebraic propereties of interacting subsystems.",0606200v1
2006-12-04,Approximate resonance states in the semigroup decomposition of resonance evolution,"The semigroup decomposition formalism makes use of the functional model for
$C_{.0}$ class contractive semigroups for the description of the time evolution
of resonances. For a given scattering problem the formalism allows for the
association of a definite Hilbert space state with a scattering resonance. This
state defines a decomposition of matrix elements of the evolution into a term
evolving according to a semigroup law and a background term. We discuss the
case of multiple resonances and give a bound on the size of the background
term. As an example we treat a simple problem of scattering from a square
barrier potential on the half-line.",0612027v1
2007-05-30,Strongly-resonant p-wave superfluids,"We study theoretically a dilute gas of identical fermions interacting via a
p-wave resonance. We show that, depending on the microscopic physics, there are
two distinct regimes of p-wave resonant superfluids, which we term ""weak"" and
""strong"". Although expected naively to form a BCS-BEC superfluid, a
strongly-resonant p-wave superfluid is in fact unstable towards the formation
of a gas of fermionic triplets. We examine this instability and estimate the
lifetime of the p-wave molecules due to the collisional relaxation into
triplets. We discuss consequences for the experimental achievement of p-wave
superfluids in both weakly- and strongly-resonant regimes.",0705.4460v1
2007-08-15,Evaluating the Signatures of the Mean Motion Resonances in the Solar System,"The characteristics of the resonant disturbing function for an asteroid
perturbed by a planet in circular orbit are discussed. The location of the
libration centers and their dependence with the orbital elements of the
resonant orbit are analyzed. A proposed numerical method (Gallardo 2006a) for
computing the strengths of the resonances is revised and applied to the region
of the main belt of asteroids showing the relevance of several mean motion
resonances (MMR) with several planets.",0708.2080v1
2007-12-23,Bidirectional wavelength tuning of semiconductor quantum dots as artificial atoms in an optical resonator,"We consider a pair of artificial atoms with different ground state energies.
By means of finite element calculations we predict that the ground state
energies can be tuned into resonance if the artificial atoms are placed into a
flexible ring structure, which is elastically deformed by an external force.
This concept is experimentally verified by embedding a low density of
self-assembled quantum dots into the wall of a rolled up micro tube ring
resonator. We demonstrate that quantum dots can elastically be tuned in- and
out of resonance with each other or with the ring resonator modes.",0712.3927v1
2008-02-25,Atomic hyperfine resonances in a magnetic quadrupole field,"The quantum resonances of an atom possessing a single valence electron which
shows hyperfine interaction with the nucleus is investigated in the presence of
a three dimensional magnetic quadrupole field. Particular emphasis is put on
the study of the interplay of the hyperfine and quadrupole forces. Analyzing
the underlying Hamiltonian a variety of symmetries are revealed which give rise
to a two-fold degeneracy of the resonance energies. Our numerical approach
employs the complex scaling method and a Sturmian basis set. Several regimes
and classes of short-lived and long-lived resonances are identified. The
energies and decay widths of the resonances are characterized by their
electronic and nuclear spin properties.",0802.3645v1
2008-03-08,Resonance Clustering in Globally Coupled Electrochemical Oscillators with External Forcing,"Experiments are carried out with a globally coupled, externally forced
population of limit-cycle electrochemical oscillators with an approximately
unimodal distribution of heterogeneities. Global coupling induces mutually
entrained (at frequency $\omega_{1}$) states; periodic forcing produces
forced-entrained ($\omega_{\mathrm{F}}$) states. As a result of the interaction
of mutual and forced entrainment, resonant cluster states occur with equal
spacing of frequencies that have discretized frequencies following a resonance
rule $\omega_{n}\cong n\omega_{1}-(n-1)\omega_{\mathrm{F}}$. Resonance
clustering requires an optimal, intermediate global coupling strength; at weak
coupling the clusters have smaller sizes and do not strictly follow the
resonance rule, while at strong coupling the population behaves similar to a
single, giant oscillator.",0803.1204v1
2008-04-28,Size-selective optical forces for microspheres using evanescent wave excitation of whispering gallery modes,"We show that when a microsphere is illuminated by an evanescent wave, the
optical forces on- and off- whispering gallery mode (WGM) resonance can differ
by several orders of magnitude. Such size selective force allows one to
selectively manipulate the resonating particles, while leaving those particles
at off-resonance untouched. As WGM resonances have very high-Q's, this kind of
force could be deployed for size-selective manipulation with a very high
accuracy (~1/Q), as well as simultaneous particle-sorting according to their
size or resonant frequency.",0804.4341v1
2008-06-18,The initial momentum dependence of the quantum resonance in the delta-kicked rotor,"The influence of an initial momentum on the appearance of ""quantum
resonances"" in the delta-kicked rotor system is explored experimentally. We
show that for certain initial momenta, a resonance can be negated entirely,
whereas at others a resonance can be made to appear. At a larger number of
kicks, all resonances are shown to narrow. We show that as a consequence, the
individual ""diffraction peaks"" may split. We compare our results to numerical
simulations as well as analytical theory.",0806.3107v3
2008-08-08,Resonant Excitation of Disk Oscillations in Deformed Disks III: Revision of Mathematical Treatment,"In previous studies, we have examined a resonant excitation of disk
oscillations in deformed disks. In these studies, however, mathematical
treatment around the resonant points was not rigorous. In this paper the
inadequate point is corrected, with no essential changes in the final results.
For this excitation process to work, disks must be general relativistic. That
is, the non-monotonic radial distribution of epicyclic frequency in
relativistic disks is essential for the presence of the resonance and for
trapping of oscillations. In this paper, the growth rate of resonant
oscillations is expressed in a form more suitable for numerical calculations.",0808.1218v1
2008-09-09,Unique resonant normal forms for area preserving maps at an elliptic fixed point,"We construct a resonant normal form for an area-preserving map near a generic
resonant elliptic fixed point. The normal form is obtained by a simplification
of a formal interpolating Hamiltonian. The resonant normal form is unique and
therefore provides the formal local classification for area-preserving maps
with the elliptic fixed point. The total number of formal invariants is
infinite. We consider the cases of weak (of order $n\ge5$) and strong (of order
$n=3,4$) resonances. We also construct unique normal forms for analytic
families of area-preserving maps.
  We note that our constructions involve non-linear grading functions.",0809.1614v1
2008-12-14,"Magnetic resonance in the cuprates -- exciton, plasmon, or π-mode","We re-analyzed the issue whether the resonance peak observed in neutron
scattering experiments on the cuprates is an exciton, a \pi-resonance, or a
magnetic plasmon. We considered a toy model with on-cite Hubbard U and
nearest-neighbor interactions in both charge and spin channels. We found that
the resonance is predominantly an exciton, even if magnetic interaction is
absent and d-wave pairing originates from attractive density-density
interaction. Our results indicate that one cannot distinguish between spin and
charge-mediated pairing interactions by just looking at the resonance peak in
the dynamic spin susceptibility.",0812.2697v1
2008-12-17,Baryon resonances in the mean field approach and a simple explanation of the Theta+ pentaquark,"We suggest to classify baryon resonances as single-quark states in a mean
field, and/or as its collective excitations. Identifying the Roper resonance
N(1440), the nucleon resonance N(1535), and the singlet hyperon Lambda(1405) as
single-quark excitations, we find that there must be an exotic S=+1 baryon
resonance Theta+ (the ""pentaquark"") with a mass about 1440+1535-1405=1570 MeV
and spin-parity one-half-plus. We argue that Theta+ is an analog of the
Gamov--Teller excitation long known in nuclear physics.",0812.3418v1
2008-12-18,Parametric resonances in electrostatically interacting carbon nanotube arrays,"We study, numerically and analytically, a model of a one-dimensional array of
carbon nanotube resonators in a two-terminal configuration. The system is
brought into resonance upon application of an AC-signal superimposed on a
DC-bias voltage. When the tubes in the array are close to each other,
electrostatic interactions between tubes become important for the array
dynamics. We show that both transverse and longitudinal parametric resonances
can be excited in addition to primary resonances. The intertube electrostatic
interactions couple modes in orthogonal directions and affect the mode
stability.",0812.3515v1
2009-01-06,Probing viscoelastic properties of a thin polymer film sheared between a beads layer and quartz crystal resonator,"We report measurements of viscoelastic properties of thin polymer films of
10-100 nm at the MHz range. These thin films are confined between a quartz
crystal resonator and a millimetric bead layer, producing an increase of both
resonance frequency and dissipation of the quartz resonator. The shear modulus
and dynamic viscosity of thin films extracted from these measurements are
consistent with the bulk values of the polymer. This modified quartz resonator
provides an easily realizable and effective tool for probing the rheological
properties of thin films at ambient environment.",0901.0630v1
2009-02-06,Calculating few-body resonances using an oscillator trap,"We investigate the possibility of calculating the parameters of few-body
resonances using the oscillator trap boundary conditions. We place the few-body
system in an oscillator trap and calculate the energy spectrum and the strength
function of a suitably chosen transition. Broader resonances are identified as
Lorentzian peaks in the strength function. Narrower resonances are identified
through the pattern of avoided crossings in the spectrum of the system as
function of the trap size. As an example we calculate 0+ resonances in 12C
within the 3-alpha model.",0902.1110v1
2009-02-24,A Primer on Resonances in Quantum Mechanics,"After a pedagogical introduction to the concept of resonance in classical and
quantum mechanics, some interesting applications are discussed. The subject
includes resonances occurring as one of the effects of radiative reaction, the
resonances involved in the refraction of electromagnetic waves by a medium with
a complex refractive index, and quantum decaying systems described in terms of
resonant states of the energy. Some useful mathematical approaches like the
Fourier transform, the complex scaling method and the Darboux transformation
are also reviewed.",0902.4061v1
2009-03-27,Effect of non-zero constant vorticity on the nonlinear resonances of capillary water waves,"The influence of an underlying current on 3-wave interactions of capillary
water waves is studied. The fact that in irrotational flow resonant 3-wave
interactions are not possible can be invalidated by the presence of an
underlying current of constant non-zero vorticity. We show that: 1) wave trains
in flows with constant non-zero vorticity are possible only for two-dimensional
flows; 2) only positive constant vorticities can trigger the appearance of
three-wave resonances; 3) the number of positive constant vorticities which do
trigger a resonance is countable; 4) the magnitude of a positive constant
vorticity triggering a resonance can not be too small.",0903.4813v1
2009-03-30,Radiative decay into $γ$-baryon decuplet of dynamically generated resonances,"We study the radiative decay into $\gamma$ and a baryon of the SU(3) decuplet
of ten resonances that are dynamically generated from the interaction of vector
mesons with baryons of the decuplet. We obtain quite different partial decay
widths for the various resonances, and for different charge states of the same
resonance, suggesting that the experimental investigation of these radiative
decays should bring much information on the nature of these resonances.",0903.5138v1
2009-05-20,Recursive T matrix algorithm for resonant multiple scattering: Applications to localized plasmon excitations,"A matrix balanced version of the Recursive Centered T Matrix Algorithm
(RCTMA) applicable to systems possessing resonant inter-particle couplings is
presented. Possible domains of application include systems containing
interacting localized plasmon resonances, surface resonances, and photonic jet
phenomena. This method is of particular interest when considering modifications
to complex systems. The numerical accuracy of this technique is demonstrated in
a study of particles with strongly interacting localized plasmon resonances.",0905.3307v1
2009-06-27,Ultracold three-body collisions near narrow Feshbach resonances,"We study ultracold three-body collisions of bosons and fermions when the
interatomic interaction is tuned near a narrow Feshbach resonance. We show that
the width of the resonance has a substantial impact on the collisional
properties of ultracold gases in the strongly interacting regime. We obtain
numerical and analytical results that allow us to identify universal features
related to the resonance width. For narrow resonances, we have found a
suppression of all inelastic processes in boson systems leading to deeply bound
states and an enhancement for fermion systems.",0906.5019v2
2009-07-19,Preparation and Detection of a Mechanical Resonator Near the Ground State of Motion,"We have cooled the motion of a radio-frequency nanomechanical resonator by
parametric coupling to a driven microwave frequency superconducting resonator.
Starting from a thermal occupation of 480 quanta, we have observed occupation
factors as low as 3.8$\pm$1.2 and expect the mechanical resonator to be found
with probability 0.21 in the quantum ground state of motion. Cooling is limited
by random excitation of the microwave resonator and heating of the dissipative
mechanical bath.",0907.3313v1
2009-08-26,High $p_T$ resonances as a possibility to explore hot and dense nuclear matter,"One of the fundamental objectives of experiments with ultrarelativistic heavy
ions is to explore strongly interacting matter at high density and high
temperature. In this investigation we study in particular the information which
can be obtained by analyzing baryonic and mesonic resonances. The decay
products of these resonances carry information on the resonances properties at
the space time point of their decay. We especially investigate the percentage
of reconstructable resonances as a function of density for heavy ion collisions
in the energy range between $E_{lab}$ = 30 AGeV and $\sqrt{s}$ = 200 AGeV, the
energy domain between the future FAIR facility and the present RHIC collider.",0908.3811v1
2009-09-24,Amplitude Noise Squeezing in Cavity-Driven Oscillations of a Mechanical Resonator,"We analyze the amplitude and phase noise of limit-cycle oscillations in a
mechanical resonator coupled parametrically to an optical cavity driven above
its resonant frequency. At a given temperature the limit-cycle oscillations
have lower amplitude noise than states of the same average amplitude excited by
a pure harmonic drive; for sufficiently low thermal noise a sub-Poissonian
resonator state can be produced. We also calculate the linewidth narrowing that
occurs in the limit-cycle states, and show that while the minimum is set by
direct phase diffusion, diffusion due to the optical spring effect can dominate
if the cavity is not driven exactly at a side-band resonance.",0909.4389v2
2010-01-18,Resonance induced by repulsive interactions in a model of globally-coupled bistable systems,"We show the existence of a competition-induced resonance effect for a generic
globally coupled bistable system. In particular, we demonstrate that the
response of the macroscopic variable to an external signal is optimal for a
particular proportion of repulsive links. Furthermore, we show that a resonance
also occurs for other system parameters, like the coupling strength and the
number of elements. We relate this resonance to the appearance of a multistable
region, and we predict the location of the resonance peaks, by a simple
spectral analysis of the Laplacian matrix.",1001.2993v1
2010-03-01,"Entropy, fidelity, and double orthogonality for resonance states in two-electron quantum dots","Resonance states of a two-electron quantum dot are studied using a
variational expansion with both real basis-set functions and complex scaling
methods. The two-electron entanglement (linear entropy) is calculated as a
function of the electron repulsion at both sides of the critical value, where
the ground (bound) state becomes a resonance (unbound) state. The linear
entropy and fidelity and double orthogonality functions are compared as methods
for the determination of the real part of the energy of a resonance. The
complex linear entropy of a resonance state is introduced using complex scaling
formalism.",1003.0468v1
2010-03-29,One More Tool for Understanding Resonance,"We propose the application of graphical convolution to the analysis of the
resonance phenomenon. This time-domain approach encompasses both the finally
attained periodic oscillations and the initial transient period. It also
provides interesting discussion concerning the analysis of non-sinusoidal
waves, based not on frequency analysis, but on direct consideration of
waveforms, and thus presenting an introduction to Fourier series. Further
developing the point of view of graphical convolution, we come to a new
definition of resonance in terms of time domain.",1003.5543v2
2010-04-04,Greatly enhanced absorption of non-resonant microwave fields by ultracold molecules near a Feshbach resonance,"We show that the probability of the collision-induced absorption of
non-resonant microwave photons by a gas of ultracold molecules is dramatically
enhanced near a Feshbach scattering resonance. This can be used for detecting
Feshbach resonances of ultracold molecules by measuring the microwave field
absorption and for tuning the elastic scattering cross sections of ultracold
molecules by varying the frequency and intensity of the microwave field in a
wide range of the field parameters.",1004.0481v2
2010-04-14,Super FSR tunable optical microbubble resonator,"An optical resonator is often called fully tunable if its tunable range
exceeds the spectral interval that contains the resonances at all the
characteristic modes of this resonator. For the high Q-factor spheroidal and
toroidal microresonators, this interval coincides with the azimuthal free
spectral range. In this Letter, we demonstrate the first mechanically fully
tunable spheroidal microresonator created of a silica microbubble having a 100
micron order radius and a micron order wall thickness. The tunable bandwidth of
this resonator is more than two times greater than its azimuthal free spectral
range.",1004.2405v1
2010-06-04,Resonant Metalenses for Breaking the Diffraction Barrier,"We introduce the resonant metalens, a cluster of coupled subwavelength
resonators. Dispersion allows the conversion of subwavelength wavefields into
temporal signatures while the Purcell effect permits an efficient radiation of
this information in the far-field. The study of an array of resonant wires
using microwaves provides a physical understanding of the underlying mechanism.
We experimentally demonstrate imaging and focusing from the far-field with
resolutions far below the diffraction limit. This concept is realizable at any
frequency where subwavelength resonators can be designed.",1006.0799v1
2010-06-04,Emission and Absorption quantum noise measurement with an on-chip resonant circuit,"Using a quantum detector, a superconductor-insulator-superconductor junction,
we probe separately the emission and absorption noise in the quantum regime of
a superconducting resonant circuit at equilibrium. At low temperature the
resonant circuit exhibits only absorption noise related to zero point
fluctuations whereas at higher temperature emission noise is also present. By
coupling a Josephson junction, biased above the superconducting gap, to the
same resonant circuit, we directly measure the noise power of quasiparticles
tunneling through the junction at two resonance frequencies. It exhibits a
strong frequency dependence, consistent with theoretical predictions.",1006.0892v2
2010-09-21,Momentum distributions from three-body decaying 9Be and 9B resonances,"The complex-rotated hyperspherical adiabatic method is used to study the
decay of low-lying $^9$Be and $^9$B resonances into $\alpha$, $\alpha$ and $n$
or $p$. We consider six low-lying resonances of $^9$Be ($1/2^\pm$, $3/2^\pm$
and $5/2^\pm$) and one resonance of $^9$B ($5/2^-$) to compare with. The
properties of the resonances at large distances are decisive for the momentum
distributions of the three decaying fragments. Systematic detailed energy
correlations of Dalitz plots are presented.",1009.4029v1
2010-09-22,Coupling Circuit Resonators Among Themselves and To Nitrogen-Vacancy Centers in Diamond,"We propose a scheme to couple NV centers in diamond through coplanar
waveguide resonators. The central conductor of the resonator is split into
several pieces which are coupled strongly with each other via simple capacitive
junctions or superconducting Josephson junctions. The NV centers are then put
at the junctions. The discontinuity at the junctions induces a large local
magnetic field, with which the NV centers are strongly coupled to the circuit
resonator. The coupling strength $g$ between the resonator and the NV center is
of order of $g/2\pi\sim 1$--$30\unit{MHz}$.",1009.4314v2
2010-10-06,Ferromagnetic Resonance in Spinor Dipolar Bose--Einstein Condensates,"We used the Gross--Pitaevskii equations to investigate ferromagnetic
resonance in spin-1 Bose--Einstein condensates with a magnetic dipole-dipole
interaction. By introducing the dipole interaction, we obtained equations
similar to the Kittel equations used to represent ferromagnetic resonance in
condensed matter physics. These equations indicated that the ferromagnetic
resonance originated from dipolar interaction, and that the resonance frequency
depended upon the shape of the condensate. Furthermore, spin currents driven by
spin diffusions are characteristic of this system.",1010.1075v1
2010-11-17,Effect of electron-phonon coupling on transmission through Luttinger liquid hybridized with resonant level,"We show that electron-phonon coupling strongly affects transport properties
of the Luttinger liquid hybridized with a resonant level. Namely, this coupling
significantly modifies the effective energy-dependent width of the resonant
level in two different geometries, corresponding to the resonant or
antiresonant transmission in the Fermi gas. This leads to a rich phase diagram
for a metal-insulator transition induced by the hybridization with the resonant
level.",1011.3934v1
2010-11-26,Nonlinear effects in resonant layers in solar and space plasmas,"The present paper reviews recent advances in the theory of nonlinear driven
magnetohydrodynamic (MHD) waves in slow and Alfven resonant layers. Simple
estimations show that in the vicinity of resonant positions the amplitude of
variables can grow over the threshold where linear descriptions are valid.
Using the method of matched asymptotic expansions, governing equations of
dynamics inside the dissipative layer and jump conditions across the
dissipative layers are derived. These relations are essential when studying the
efficiency of resonant absorption. Nonlinearity in dissipative layers can
generate new effects, such as mean flows, which can have serious implications
on the stability and efficiency of the resonance.",1011.5786v1
2010-11-26,Scalar-Pseudoscalar scattering and pseudoscalar resonances,"The interactions between the f_0(980) and a_0(980) scalar resonances and the
lightest pseudoscalar mesons are studied. We first obtain the interacting
kernels, without including any ad hoc free parameter, because the lightest
scalar resonances are dynamically generated. These kernels are unitarized,
giving the final amplitudes, which generate pseudoscalar resonances, associated
with the K(1460), \pi(1300), \pi(1800), \eta(1475) and X(1835). We also
consider the exotic channels with I=3/2 and I^G=1^+ quantum numbers. The former
could be also resonant in agreement with a previous prediction.",1011.5843v1
2010-12-02,Hybrid metal-dielectric ring resonators for optical magnetic metamaterials down to ultraviolet range,"In this paper, we derive a model from Maxwell equations for the magnetic
resonance of split-ring resonators. Using this model we revisit the scaling of
split-ring resonators. Inspired by our model, we propose a new type of
split-hybrid metal-dielectric ring resonator, of which the ring is made
composed of moderately high index dielectric material (e.g. SiC, TiO2, ZnS)
(for the major portion), while and metal (e.g. Ag) fills the gap. Such a new
magnetic metamaterial is able to overcome the saturation problem of split-ring
resonatorssaturation-free and therefore is able to operate at short wavelength
down to ultraviolet range.",1012.0400v2
2010-12-14,Electromagnetic production of hyperon resonances,"The study of hyperon resonances has entered a new era of precision with
advent of high-statistics photoproduction data from the CLAS detector at
Jefferson Lab. These data have multi-particle final states, allowing clean
identification of exclusive reactions associated with strange mesons and
baryons. Examples of physics results are: evidence for isospin interference in
the decay of the $\Lambda(1405)$ resonance; a strong suggestion of meson cloud
effects in the structure of the $\Sigma(1385)$ resonance; data from $K^*$
photoproduction that will test the existence of the purported $K_0(800)$ meson.
Properties of other hyperon resonances will also be studied in the near future.",1012.3129v1
2010-12-27,Quantum behaviour of a flux qubit coupled to a resonator,"We present a detailed theoretical analysis for a system of a superconducting
flux qubit coupled to a transmission line resonator. The master equation,
accounting incoherent processes for a weakly populated resonator, is
analytically solved. An electromagnetic wave transmission coefficient through
the system, which provides a tool for probing dressed states of the qubit, is
derived. We also consider a general case for the resonator with more than one
photon population and compare the results with an experiment on the
qubit-resonator system in the intermediate coupling regime, when the coupling
energy is comparable with the qubit relaxation rate.",1012.5599v1
2011-01-16,Fano resonances in magnetic metamaterials,"We study the scattering of magnetoinductive plane waves by internal
(external) capacitive (inductive) defects coupled to a one-dimensional
split-ring resonator array. We examine a number of simple defect configurations
where Fano resonances occur and study the behavior of the transmission
coefficient as a function of the controllable external parameters. We find that
for embedded capacitive defects, the addition of a small amount of coupling to
second neighbors is necessary for the occurrence of Fano resonance. For
external inductive defects, Fano resonances are commonplace, and they can be
tuned by changing the relative orientation or distance between the defect and
the SSR array.",1101.3032v2
2011-02-21,Stable double-resonance optical spring in laser gravitational-wave detectors,"We analyze the optical spring characteristics of a double pumped Fabry-Perot
cavity. A double-resonance optical spring occurs when the optical spring
frequency and the detuning frequency of the cavity coincide. We formulate a
simple criterion for the stability of an optical spring and apply it to the
double resonance regime. Double resonance configurations are very promising for
future gravitational wave detectors as they allow us to surpass the Standard
Quantum Limit. We show that stable double resonance can be demonstrated in
middle scale prototype interferometers such as the Glasgow 10m-Prototype,
Gingin High Optical Power Test Facility or the AEI 10m Prototype Interferometer
before being implemented in future gravitational wave detectors.",1102.4266v1
2011-02-22,The n:m resonance dual pair,"In this paper we build dual pairs of Poisson maps \[
\RR\stackrel{R_\pm}{\longleftarrow}(D,\om_\pm)
\stackrel{\Pi_\pm}{\longrightarrow} B \] associated to $n:m$ resonance, as well
as to $n:-m$ resonance. Except for the above mentioned cases $1:\pm1$, these
are not pairs of momentum maps. Here $D$ is an open subset of $\CC^2$ with the
above mentioned symplectic forms $\om_\pm$, and $B$ an open subset of $\RR^3$.
The Poisson structure on $B$, which depends on the natural numbers $n$ and $m$,
is not Lie-Poisson. Instead, its symplectic leaves are the Kummer shapes:
bounded surfaces for $n:m$ resonance, and unbounded surfaces for $n:-m$
resonance",1102.4377v1
2011-04-18,Characterization of a microwave frequency resonator via a nearby quantum dot,"We present measurements of a hybrid system consisting of a microwave
transmission-line resonator and a lateral quantum dot defined on a GaAs
heterostructure. The two subsystems are separately characterized and their
interaction is studied by monitoring the electrical conductance through the
quantum dot. The presence of a strong microwave field in the resonator is found
to reduce the resonant conductance through the quantum dot, and is attributed
to electron heating and modulation of the dot potential. We use this
interaction to demonstrate a measurement of the resonator transmission spectrum
using the quantum dot.",1104.3535v1
2011-04-21,Coherent spectroscopy of rare-earth-ion doped whispering-gallery mode resonators,"We perform an investigation into the properties of Pr3+:Y2SiO5 whispering
gallery mode resonators as a first step towards achieving the strong coupling
regime of cavity QED with rare-earth-ion doped crystals. Direct measurement of
cavity QED parameters are made using photon echoes, giving good agreement with
theoretical predictions. By comparing the ions at the surface of the resonator
to those in the center it is determined that the physical process of making the
resonator does not negatively affect the properties of the ions. Coupling
between the ions and resonator is analyzed through the observation of optical
bistability and normal-mode splitting.",1104.4150v1
2011-05-20,Asymmetric resonance in selective reflection: Explanation via Fano-like mechanism,"Fano mechanism is the universal explanation of asymmetric resonance appearing
in different systems. We report the evidence of Fano-like resonance in
selective reflection from a resonant two-level medium. We draw an analogy with
the asymmetric resonance previously obtained for the coupled oscillators. We
also take into account the effects of dielectric background and local-field
correction and connect our results with optical bistability.",1105.4020v1
2011-06-22,Storing light as a mechanical excitation in a silica optomechanical resonator,"We report the experimental demonstration of optomechanical light storage in a
silica resonator. We use writing and readout laser pulses tuned to one
mechanical frequency below an optical cavity resonance to control the coupling
between the mechanical displacement and the optical field at the cavity
resonance. The writing pulse maps a signal pulse at the cavity resonance to a
mechanical excitation. The readout pulse later converts the mechanical
excitation back to an optical pulse. The light storage lifetime is determined
by the relatively long damping time of the mechanical excitation.",1106.4512v1
2011-06-28,The Friedrichs Model and its use in resonance phenomena,"We present here a relation of different types of Friedrichs models and their
use in the description and comprehension of resonance phenomena. We first
discuss the basic Friedrichs model and obtain its resonance in the case that
this is simple or doubly degenerated. Next, we discuss the model with $N$
levels and show how the probability amplitude has an oscillatory behavior. Two
generalizations of the Friedrichs model are suitable to introduce resonance
behavior in quantum field theory. We also discuss a discrete version of the
Friedrichs model and also a resonant interaction between two systems both with
continuous spectrum. In an Appendix, we review the mathematics of rigged
Hilbert spaces.",1106.5782v1
2011-07-29,Coupling constants of the $S_{11}$ resonances to pseudoscalar mesons and octet baryons,"Coupling constants of $S_{11}(1535)$ and $S_{11}(1650)$ resonances to
meson-baryon ($\pi N$, $\eta N$, $\eta^\prime N$, $KY$) are investigated in a
chiral quark model, complemented by inclusion of five-quark components in those
resonances. The known strong decay partial widths of both resonances are well
reproduced, provided sizeable strangeness components in the relevant wave
functions. %to excellent description for the strong decays of the above two
resonances, which %cannot be reproduced very well in the traditional chiral
quark model with or without %$SU(6)\otimes O(3)$ breaking. Finally, we find
that $S_{11}(1535)$ and $S_{11}(1650)$ %couple strongly to the channels with
strangeness.",1107.5991v2
2011-08-04,Higher-order optical resonance node detection of integrated disk microresonator,"We have demonstrated higher-order optical resonance node detection by using
an integrated disk microresonator from through port of the coupling bus
waveguide. In addition to the fundamental mode, the disk resonator has
higher-order whispering gallery modes. The excited second-order higher-order
mode has a node at the position where the electromagnetic energy of the
fundamental mode is close to a maximum. This high resolution measurement of
optical resonance mode profile has a variety of applications for optical
sensing and detection. The self-referencing characteristics of the two optical
resonance modes have potential to achieve optical detection independent of
external perturbation, such as temperature change.",1108.1082v1
2012-02-03,Magnetic resonance in the ordered phases of the 2D frustrated quantum magnet Cs2CuCl4,"The temperature evolution of the electron spin resonance is studied at
cooling the crystal samples of Cs2CuCl4 through the Neel point 0.62 K. A
coexistence of the high-frequency spinon type resonance developed in the
spin-liquid phase and of the low-frequency antiferromagnetic resonance was
found in the ordered phase. The low-frequency magnetic resonance spectrum in
the low field range has two gapped branches and corresponds well to the
spectrum of spin excitations of a planar spiral spin structure with two axes of
the anisotropy. The field induced phase transitions result in a more
complicated low-frequency spectra.",1202.0783v1
2012-02-14,Design and Fabrication of Micromachined Resonators,"Microelectromechanical system (MEMS) based on-chip resonators offer great
potential for sensing and high frequency signal processing applications due to
their exceptional features like small size, large frequency-quality factor
product, integrability with CMOS ICs, low power consumption etc. This work is
mainly aimed at the design, modeling, simulation, and fabrication of
micromachined polysilicon disk resonators exhibiting radial-contour mode
vibrations. A few other bulk mode modified resonator geometries are also being
explored. The resonator structures have been designed and simulated in
CoventorWare finite-element platform and fabricated by the PolyMUMPs surface
micromachining process.",1202.3048v1
2012-07-20,High-frequency nanotube mechanical resonators,"We report on a simple method to fabricate high-frequency nanotube mechanical
resonators reproducibly. We measure resonance frequencies as high as 4.2 GHz
for the fundamental eigenmode and 11 GHz for higher order eigenmodes. The
high-frequency resonances are achieved using short suspended nanotubes and by
introducing tensile stress in the nanotube. These devices allow us to determine
the coefficient of the thermal expansion of an individual nanotube, which is
negative and is about -0.7E-5 1/K at room temperature. High-frequency
resonators made of nanotubes hold promise for mass sensing and experiments in
the quantum limit.",1207.4874v1
2012-08-17,"Bayesian inference of the resonance content of p(gamma,K+)Lambda","A Bayesian analysis of the world's p(gamma,K+)Lambda data is presented. We
adopt a Regge-plus-resonance framework featuring consistent couplings for
nucleon resonances up to spin J=5/2, and evaluate 2048 model variants
considering all possible combinations of 11 candidate resonances. The best
model, labeled RPR-2011, is discussed with special emphasis on nucleon
resonances in the 1900-MeV mass region.",1208.3618v1
2012-09-27,Resonance linewidth and inhomogeneous broadening in a metamaterial array,"We examine the effect of inhomogeneous broadening on the collective response
of a planar metamaterial consisting of asymmetric split ring resonators. We
show that such a response leads to a transmission resonance that can persist
when the broadening of individual meta-atom resonance frequencies is roughly
one half the frequency characterizing the split ring asymmetry. We also find
that larger degrees of inhomogeneous broadening can drastically alter the
cooperative response, destroying this resonance. The reduced effect of
cooperative response due to inhomogeneous broadening may find applications in
producing metamaterial samples that more closely mimic homogeneous
magneto-dielectric medium with well-defined susceptibility and permittivity.",1209.6154v1
2012-11-05,Enhancement of four reflection shifts by a three-layer surface plasmon resonance,"We investigate the effect of a surface plasmon resonance on Goos-Hanchen and
Imbert-Fedorov spatial and angular shifts in the reflection of a light beam by
considering a three-layer system made of glass, gold and air. We calculate
these spatial and angular shifts as a function of the incidence angle showing
that they are strongly enhanced in correspondence of the resonant angle. In
particular, we find giant spatial and angular Goos-Hanchen shits for the p-wave
light close to the plasmon resonance. We also predict a similar, but less
pronounced, resonant effect on spatial and angular Imbert-Fedorov shifts for
both s-wave and p-wave light.",1211.1050v1
2012-11-26,Review of lattice studies of resonances,"I review recent progress in extracting resonance parameters using lattice
field theory, with an emphasis on determining hadron resonances from lattice
quantum chromodynamics. Until recently, the \rho-meson channel was the only one
considered, while, during the last year, several resonant channels have been
investigated for the first time. Recent lattice results for scattering phase
shifts in resonant channels are presented.",1211.6163v1
2013-01-03,Low-loss tunable metamaterials using superconducting circuits with Josephson junctions,"We report on experiments with superconducting metamaterials containing
Josephson junctions. In these structures, split-ring resonators used in
conventional metamaterials are replaced by superconducting loops that are
interrupted by Josephson junctions, so called rf-SQUIDs. Like the split-ring
resonators, these elements can be seen as LC-resonators that couple to the
magnetic field. The advantage of superconducting thin-film metamaterials is
that, due to the tunable intrinsic inductance of the Josephson junction, the
resonance frequency of the rf-SQUID can be changed by applying an external dc
magnetic field. We present experimental results that demonstrate the tunability
of the resonance frequency of these devices.",1301.0440v1
2013-01-08,Hadronic Resonances in Heavy-Ion Collisions at ALICE,"Modifications to the masses and widths of hadronic resonances in heavy-ion
collisions could be a sign of chiral symmetry restoration. Uncorrected spectra,
masses, and widths of the phi(1020) and K*(892)0 resonances have been measured
in Pb-Pb collisions at 2.76 TeV using the ALICE detector. These measurements
are presented and compared to resonances in other collision systems.",1301.1581v1
2013-01-28,Comparison of f-Q scaling in wineglass and radial modes in ring resonators,"Low phase noise MEMS oscillators necessitate resonators with high f-Q.
Resonators achieving high f-Q (mechanical frequency-quality factor product)
close to the thermo-elastic damping (TED) limit have been demonstrated at
expense of feed-through. Here we present a study comparing frequency scaling of
quality factors of wineglass and radial modes in a ring resonator using an
opto-mechanical two port transmission measurement. Higher harmonics of the
wineglass mode show an increasing trend in the f-Q product, as compared to a
saturation of f-Q for radial modes. The measured f-Q of 5.11e13Hz at 9.82GHz in
air at room temperature for a wineglass mode is close to the highest measured
values in silicon resonators.",1301.6564v1
2013-02-05,Metamaterial atom with multijunction superconducting structure,"We present results of numerical simulations of a metamaterial element
(meta-atom) for planar negative media based on cuprate Josephson junctions. The
proposed circuit consists of two coupled resonators: ""magnetic dipole"" and
""electric dipole"". The first one is a superconducting spiral resonator with
multijunction superconducting structure - SQIF (SQIF - superconducting quantum
interference filter), and the second one is a comb-shape resonator made from
normal metal film. We show, that in comparison with passive metal resonators,
the superconducting resonator with Josephson junctions (magnetic dipole) can be
tuned by external magnetic field due to magnetic dependence of Josephson
inductance. The simulated characteristics of one-dimensional planar negative
media are discussed.",1302.0997v1
2013-04-01,Orbital resonances around Black holes,"We compute the length and timescales associated with resonant orbits in the
Kerr Metric for all orbital and spin parameters. Resonance induced effects are
potentially observable when the Event Horizon telescope resolves the inner
structure of Sgr A*, space-based gravitational wave detectors record
phase-shifts in the waveform during the resonant passage of a neutron star as
it spirals in to the black hole and in the frequencies of quasi periodic
oscillations for accreting black holes. The onset of geodesic chaos for
non-Kerr spacetimes should occur at the resonance locations quantified here.",1304.0330v1
2013-05-16,Metamaterial transparency induced by cooperative electromagnetic interactions,"We propose a cooperative asymmetry-induced transparency, CAIT, formed by
collective excitations in metamaterial arrays of discrete resonators. CAIT can
display a sharp transmission resonance even when the constituent resonators
individually exhibit broad resonances. We further show how dynamically
reconfiguring the metamaterial allows one to actively control the transparency.
While reminiscent of electromagnetically induced transparency, which can be
described by independent emitters, CAIT relies on a cooperative response
resulting from strong radiative couplings between the resonators.",1305.3808v1
2013-05-21,Distribution of resonances for hyperbolic surfaces,"We study the distribution of resonances for geometrically finite hyperbolic
surfaces of infinite area by countting resonances numerically. The resonances
are computed as zeros of the Selberg zeta function, using an algorithm for
computation of the zeta function for Schottky groups. Our particular focus is
on three aspects of the resonance distribution that have attracted attention
recently: the fractal Weyl law, the spectral gap, and the concentration of
decay rates.",1305.4850v2
2013-06-04,Hadronic Resonance Production with ALICE Experiment at LHC,"The production of resonances in heavy-ion collisions is expected to be
sensitive to the properties of strongly interacting matter created in such
collisions. We report on the measurements of $\phi$ and $K^{*0}$ resonances in
Pb-Pb collisions at $\sqrt{s_{NN}} $ = 2.76 TeV. The masses, widths and yields
in Pb-Pb collisions as a function of centrality are compared to that in pp
collisions to understand the role of re-scattering and regeneration. The
resonance to non-resonance particle ratios are shown as a function of collision
centrality and compared with the results at lower energies.",1306.0673v1
2013-06-10,Spin Transfer of Quantum Information between Majorana Modes and a Resonator,"We show that resonant coupling and entanglement between a mechanical
resonator and majorana bound states can be achieved via spin currents in a 1D
quantum wire with strong spin-orbit interactions. The bound states induced by
vibrating and stationary magnets can hybridize thus resulting in spin-current
induced $4\pi$-periodic torque, as a function of the relative field angle,
acting on the resonator. We study the feasibility of detecting and manipulating
majorana bound states with the use of magnetic resonance force microscopy
techniques.",1306.2339v1
2013-06-12,Overcoming Si3N4 film stress limitations for High Quality factor ring resonators,"Silicon nitride (Si3N4) ring resonators are critical for a variety of
photonic devices. However the intrinsically high film stress of silicon nitride
has limited both the optical confinement and quality factor (Q) of ring
resonators. We show that stress in Si3N4 films can be overcome by introducing
mechanical trenches for isolating photonic devices from propagating cracks. We
demonstrate a Si3N4 ring resonator with an intrinsic quality factor of 7
million, corresponding to a propagation loss of 4.2 dB/m. This is the highest
quality factor reported to date for high confinement Si3N4 ring resonators in
the 1550 nm wavelength range.",1306.2994v1
2013-10-12,Resonant dynamics of chromium condensates,"We numerically study the dynamics of a spinor chromium condensate in low
magnetic fields. We show that the condensate evolution has a resonant character
revealing rich structure of resonances similar to that already discussed in the
case of alkali-atoms condensates. This indicates that dipolar resonances occur
commonly in the systems of cold atoms. In fact, they have been already observed
experimentally. We further simulate two recent experiments with chromium
condensates, in which the threshold in spin relaxation and the spontaneous
demagnetization phenomena were observed. We demonstrate that both these effects
originate in resonant dynamics of chromium condensate.",1310.3384v1
2013-10-21,Resonant state expansion applied to planar waveguides,"The resonant state expansion, a recently developed method in electrodynamics,
is generalized here to planar open optical systems with non-normal incidence of
light. The method is illustrated and verified on exactly solvable examples,
such as a dielectric slab and a Bragg reflector microcavity, for which explicit
analytic formulas are developed. This comparison demonstrates the accuracy and
convergence of the method. Interestingly, the spectral analysis of a dielectric
slab in terms of resonant states reveals an influence of waveguide modes in the
transmission. These modes, which on resonance do not couple to external light,
surprisingly do couple to external light for off-resonant excitation.",1310.5600v1
2013-11-13,Purely imaginary polar resonances of rapidly-rotating Kerr black holes,"We prove the existence of a unique family of non-oscillatory
(purely-imaginary) polar quasinormal resonances of rapidly-rotating Kerr black
holes. These purely imaginary resonances can be expressed in the compact form:
w_n=-i2*pi*T_{BH}*(l+1+n), where T_{BH} is the black-hole temperature, l is the
spheroidal harmonic index of the mode, and n=0,1,2,... is the resonance
parameter. It is shown that our analytical results for the black-hole resonance
spectrum agree with new numerical data that recently appeared in the
literature.",1311.3007v1
2013-12-03,Cyclotron-resonance-assisted photon drag effect in InSb/InAlSb quantum wells excited by terahertz radiation,"We report on the observation of the cyclotron-resonance-assisted photon drag
effect. Resonant photocurrent is detected in InSb/InAlSb quantum wells
structures subjected to a static magnetic field and excited by terahertz
radiation at oblique incidence. The developed theory based on Boltzmann's
kinetic equation is in a good agreement with the experimental findings. We show
that the resonant photocurrent originates from the transfer of photon momentum
to free electrons drastically enhanced at cyclotron resonance.",1312.0726v1
2014-01-23,Can new heavy gauge bosons be observed in ultra-high energy cosmic neutrino events?,"A wide range of models beyond the Standard Model predict charged and neutral
resonances, generically called $W'$- and $Z'$-bosons, respectively. In this
paper we study the impact of such resonances on the deep inelastic scattering
of ultra-high energy neutrinos as well as on the resonant charged current
$\bar\nu_e e^-$ scattering (Glashow resonance). We find that the effects of
such resonances can not be observed with the Pierre Auger Observatory or any
foreseeable upgrade of it.",1401.6012v1
2014-07-15,Molecular-absorption-induced thermal bistablity in PECVD silicon nitride microring resonators,"The wavelength selective linear absorption in communication C-band is
investigated in CMOS-processed PECVD silicon nitride rings. In the overcoupled
region, the linear absorption loss lowers the on-resonance transmission of a
ring resonator and increases its overall quality factor. Both the linear
absorption and ring quality factor are maximized near 1520 nm. The direct
heating by phonon absorption leads to thermal optical bistable switching in
PECVD silicon nitride based microring resonators. We calibrate the linear
absorption rate in the microring resonator by measuring its transmission
lineshape at different laser power levels, consistent with coupled mode theory
calculations.",1407.4146v1
2014-07-17,Logic-Memory Device of a Mechanical Resonator,"We report multifunctional operation based on the nonlinear dynamics in a
single microelectromechanical system (MEMS) resonator. This Letter focuses on a
logic-memory device that uses a closed loop control and a nonlinear MEMS
resonator in which multiple states coexist. To obtain both logic and memory
operations in a MEMS resonator, we examine the nonlinear dynamics with and
without control input. Based on both experiments and numerical simulations, we
develop a novel device that combines an OR gate and memory functions in a
single MEMS resonator.",1407.4858v1
2014-08-25,Coherent control of non-Markovian photon-resonator dynamics,"We study the unitary time evolution of photons interacting with a dielectric
resonator using coherent control pulses. We show that non-Markovianity of
transient photon dynamics in the resonator subsystem may be controlled to
within a photon-resonator transit time. In general, appropriate use of coherent
pulses and choice of spatial subregion may be used to create and control a wide
range of non-Markovian transient dynamics in photon resonator systems.",1408.5844v1
2014-10-31,Feshbach Resonances in Kerr Frequency Combs,"We show that both the power and repetition rate of a frequency comb generated
in a nonlinear ring resonator, pumped with continuous wave (cw) coherent light,
are modulated. The modulation is brought about by the interaction of the cw
background with optical pulses excited in the resonator, and occurs in
resonators with nonzero high-order chromatic dispersion and
wavelength-dependent quality factor. The modulation frequency corresponds to
the detuning of the pump frequency from the eigenfrequency of the pumped mode
in the resonator.",1410.8604v1
2014-12-12,Contribution of resonance tunneling of molecule to physical observables,"Probabilities of resonant tunneling through a potential barrier are compared
for a rigid molecule and an excited molecule. It is shown that the resonance
spectrum is mainly governed by the transmission resonance spectrum of the rigid
molecule. Analytical expressions for the probability for the tunneling of the
rigid molecule through a barrier allow resonance-spectrum-averaged observables,
including quantum diffusion, to be estimated.",1412.3905v1
2015-01-08,Dissociative electron attachment and electron-impact resonant dissociation of vibrationally excited O2 molecules,"State-by-state cross sections for dissociative electron attachment and
electron-impact dissociation for molecular oxygen are computed using ab initio
resonance curves calculated with the R-matrix method. When O2 is in its
vibrational ground state, the main contribution for both processes comes from
the $^2\Pi_u$ resonance state of $O_2^-$ but with a significant contribution
from the $^4\Sigma$ resonant state. Vibrational excitation leads to an
increased contribution from the low-lying $^2\Pi_{g}$ resonance, greatly
increased cross sections for both processes, and the threshold moving to lower
energies. These results provide important input for models of O2-containing
plasmas in nonequilibrium conditions.",1501.01771v1
2015-01-29,Purcell factor of Mie resonators featuring electric and magnetic modes,"We present a modal approach to compute the Purcell factor in Mie resonators
exhibiting both electric and magnetic resonances. The analytic expressions of
the normal modes are used to calculate the effective volumes. We show that
important features of the effective volume can be predicted thanks to the
translation-addition coefficients of a displaced dipole. Using our formalism,
it is easy to see that, in general, the Purcell factor of Mie resonators is not
dominated by a single mode, but rather by a large superposition. Finally we
consider a silicon resonator homogeneously doped with electric dipolar
emitters, and we show that the average electric Purcell factor dominates over
the magnetic one.",1501.07452v2
2015-03-13,Non-Schlesinger Isomonodromic Deformations of Fuchsian Systems and Middle Convolution,"The paper is devoted to non-Schlesinger isomonodromic deformations for
resonant Fuchsian systems. There are very few explicit examples of such
deformations in the literature. In this paper we construct a new example of the
non-Schlesinger isomonodromic deformation for a resonant Fuchsian system of
order 5 by using middle convolution for a resonant Fuchsian system of order 2.
Moreover, it is known that middle convolution is an operation that preserves
Schlesinger's deformation equations for non-resonant Fuchsian systems. In this
paper we show that Bolibruch's non-Schlesinger deformations of resonant
Fuchsian systems are, in general, not preserved by middle convolution.",1503.03959v1
2015-05-04,Does Geometric Coupling Generates Resonances?,"Geometrical coupling in a co-dimensional one Randall-Sundrum scenario (RS) is
used to study resonances of $p-$form fields. The resonances are calculated
using the transfer matrix method. The model studied consider the standard RS
with delta-like branes, and branes generated by kinks and domain-wall as well.
The parameters are changed to control the thickness of the smooth brane. With
this a very interesting pattern is found for the resonances. The geometrical
coupling does not generate resonances for the reduced $p-$form in all cases
considered.",1505.00689v2
2015-05-05,A Resonance Problem in Relaxation of Ground States of Nonlinear Schrodinger Equations,"In this paper we consider a resonance problem, in a generic regime, in the
consideration of relaxation of ground states of semilinear Schrodinger
equations. Different from previous results, our consideration includes the
presence of resonance, resulted by overlaps of frequencies of different states.
All the known key results, proved under non-resonance conditions, have been
recovered uniformly. These are achieved by better understandings of normal form
transformation and Fermi Golden rule. Especially, we find that if certain
denominators are zeros (or small), resulted by the presence of resonances (or
close to it), then cancellations between terms make the corresponding
numerators proportionally small.",1505.01107v1
2015-05-22,Counting function of magnetic resonances for exterior problems,"We study the asymptotic distribution of the resonances near the Landau levels
$\Lambda\_q =(2q+1)b$, $q \in \mathbb{N}$, of the Dirichlet (resp. Neumann,
resp. Robin) realization in the exterior of a compact domain of $\mathbb{R}^3$
of the 3D Schr{\""o}dinger operator with constant magnetic field of scalar
intensity $b\textgreater{}0$. We investigate the corresponding resonance
counting function and obtain the main asymptotic term. In particular, we prove
the accumulation of resonances at the Landau levels and the existence of
resonance free sectors. In some cases, it provides the discreteness of the set
of embedded eigenvalues near the Landau levels.",1505.06026v1
2015-06-08,Clear Identification of Previously Unresolved Overlapping Resonances in Dissociative Electron Attachment: A Case Study on Chlorine Molecule,"An observed broad resonance peak in dissociative electron attachment (DEA)
cross sections to a molecule might be due to either closely lying or
overlapping resonances involved in the process. We developed a state-of-the-art
experimental approach that enables us to identify unambiguously both the
closely lying and the overlapping resonances based on kinetic energy and/or
angular distribution measurements of fragment negative ion(s) generated from
DEA process. Experimental observations strongly supported by theoretical
potential energy curve calculations unambiguously identify previously
unresolved overlapping resonances in DEA to chlorine molecule.",1506.02524v1
2015-07-03,Unitarity implications of diboson resonance in the TeV region for Higgs physics,"We investigate the implications of a putative new resonance in the TeV region
coupled to the weak bosons. By studying perturbative unitarity in longitudinal
WW scattering, we find that a weakly coupled spin-1 resonance, that explains
the ATLAS diboson excesses, is allowed with a SM-like Higgs. On the other hand,
larger values of the resonance couplings, preferred in models of strong
dynamics, would imply either sizeable reduction of the Higgs couplings or new
physics, beyond the diboson resonance, at a few TeV.",1507.00900v1
2015-07-24,Pseudo orbit expansion for the resonance condition on quantum graphs and the resonance asymptotics,"In this note we explain the method how to find the resonance condition on
quantum graphs, which is called pseudo orbit expansion. In three examples with
standard coupling we show in detail how to obtain the resonance condition. We
focus on non-Weyl graphs, i.e. the graphs which have fewer resonances than
expected. For these graphs we explain benefits of the method of ""deleting
edges"" for simplifying the graph.",1507.06845v2
2015-08-05,Controlling carbon nanotube photoluminescence using silicon microring resonators,"We report on coupling between semiconducting single-wall carbon nanotubes
(s-SWNT) photoluminescence and silicon microring resonators. Polyfluorene
extracted s-SWNT deposited on such resonators exhibit sharp emission peaks, due
to interaction with the cavity modes of the microring resonators. Ring
resonators with radius of 5 {\mu}m and 10 {\mu}m were used, reaching quality
factors up to 4000 in emission. These are among the highest values reported for
carbon nanotubes coupled with an integrated cavity on silicon platform, which
open up the possibility to build s-SWNT based efficient light source on
silicon.",1508.01007v1
2015-09-06,Feshbach-Resonance-Enhanced Coherent Atom-Molecule Conversion with Ultra-Narrow Photoassociation Resonance,"We reveal the existence of high-density Feshbach resonances in the collision
between the ground and metastable states of $^{171}$Yb and coherently produce
the associated Feshbach molecules by photoassociation. The extremely small
transition rate is overcome by the enhanced Franck-Condon factor of the weakly
bound Feshbach molecule, allowing us to observe Rabi oscillations with long
decay time between an atom pair and a molecule in an optical lattice. We also
perform the precision measurement of the binding energies, which characterizes
the observed resonances. The ultra-narrow photoassociation will be a basis for
practical implementation of optical Feshbach resonances.",1509.01830v1
2015-09-27,Self-Assembled Graphene Plasmon Resonators,"The ability to fabricate dense small features over a large area is important
for graphene plasmonics. We present the first self-assembled graphene plasmonic
resonators operating in the mid-IR. The resonators are 35 nm in diameter with
20 nm spacing and cover a centimeter sized area. The resonators exhibit a very
broad resonance. We fit our data using a drude model and combine it with SEM
data to investigate the contribution to broadening from our process. We find
that the self-assembly does not contribute significantly to the broadening
observed.",1509.08118v1
2015-11-21,Mathematical analysis of plasmonic resonances for nanoparticles: the full Maxwell equations,"In this paper we use the full Maxwell equations for light propagation in
order to analyze plasmonic resonances for nanoparticles. We mathematically
define the notion of plasmonic resonance and analyze its shift and broadening
with respect to changes in size, shape, and arrangement of the nanoparticles,
using the layer potential techniques associated with the full Maxwell
equations. We present an effective medium theory for resonant plasmonic systems
and derive a condition on the volume fraction under which the Maxwell-Garnett
theory is valid at plasmonic resonances.",1511.06817v1
2016-01-13,Apex-angle-dependent resonances in triangular split ring resonators,"Along with other frequency selective structures [1] (circles and squares),
triangular split-ring resonators (TSRRs) only allow frequencies near the center
resonant frequency to propagate. Further, TSRRs are attractive due to their
small surface area [2], comparatively, and large quality factors (Q) factors as
previously investigated by Gay-Balmaz, et al. [3]. In this work we examine the
effects of varying the apex angle on the resonant frequency, the Q factor, and
the phase shift imparted by the TSRR element within the GHz frequency regime.",1601.03265v1
2016-03-02,Tilted excitation implies odd periodic resonances,"Our aim is to unveil how resonances of parametric systems are affected when
symmetry is broken. We showed numerically and experimentally that odd
resonances indeed come about when the pendulum is excited along a tilted
direction. Applying the Melnikov subharmonic function, we not only determined
analytically the loci of saddle-node bifurcations delimiting resonance regions
in parameter space, but also explained these observations by demonstrating
that, under the Melnikov method point of view, odd resonances arise due to an
extra torque that appears in the asymmetric case.",1603.00819v2
2016-06-16,Resonance interaction of two dipoles in optically active surroundings,"We study the resonance interaction between two quantum electric dipoles
immersed in optically active surroundings. Quantum electrodynamics is employed
to deal with dipole-vacuum interaction. Our results show that the optical
activity of surroundings will not change the single atom behaviors while it can
change the collective behaviors of the two dipoles, as well as greatly affect
the dipole-dipole resonance interaction. Especially, if the orientations of two
dipoles are orthogonal and respectively perpendicular to the interdipole axis,
the interdipole resonance interaction can be established with the help of
optically active surroundings while there is no resonance interaction in
vacuum.",1606.05149v1
2016-09-29,Complex-Path Prediction of Resonance-Assisted Tunneling in Mixed Systems,"We present a semiclassical prediction of regular-to-chaotic tunneling in
systems with a mixed phase space, including the effect of a nonlinear resonance
chain. We identify complex paths for direct and resonance-assisted tunneling in
the phase space of an integrable approximation with one nonlinear resonance
chain. We evaluate the resonance-assisted contribution analytically and give a
prediction based on just a few properties of the classical phase space. For the
standard map excellent agreement with numerically determined tunneling rates is
observed. The results should similarly apply to ionization rates and quality
factors.",1609.09276v2
2016-10-27,Negative refractive index induced by percolation in disordered metamaterials,"An effective medium model is developed for disordered metamaterials
containing a spatially random distribution of dielectric spheres. Similar to
effective medium models for ordered metamaterials, this model predicts
resonances in the effective permeability and permittivity arising from
electric- and magnetic-dipole Mie resonances in the spheres. In addition, the
model predicts a redshift of the electric resonance with increasing particle
loading. Interestingly, when the particle loading exceeds the percolation
threshold of 33\%, the model predicts that the electric resonance overlaps with
the magnetic resonance, resulting in a negative refractive index.",1610.08704v2
2017-02-13,Quantum dot resonant-fluorescence linewidth narrowing and enhanced intensity,"We study the processes in a quantum dot and its surrounds under resonant
excitation with the addition of weak non-resonant light. We observe a decrease
in inhomogeneous emission linewidth, as well as previously observed enhancement
of resonant fluorescence (RF). Scanning excitation and detection frequencies,
we distinguish between homogeneous and inhomogeneous broadening. Monte Carlo
simulations model the enhanced RF only if we include charge-carrier loss from
the quantum dot induced by the resonant laser. The cause of the linewidth
narrowing is predominantly independent of the enhanced RF.",1702.03947v1
2018-02-19,Spin-Orbit Coupling Induced Resonance in an Ultracold Bose Gas,"We study a two-component Bose gas with artificial spin-orbit coupling (SOC)
which couples the center-of-mass momentum of atom to its internal states. We
show that in this system resonance can be induced by tuning SOC strength. With
a two-dimensional SOC, resonances in two scattering channels can be induced by
tuning the aspect ratio of SOC strengths. With a three-dimensional SOC,
resonance in all scattering channels can be induced by tuning the appropriate
SOC strength. Similarly, we also find that in a Fermi gas with two- or
three-dimensional SOC resonance can be induced by tuning SOC strength.",1802.06522v2
2018-04-04,Wideband Bandpass Filters Based on Multipole Resonances of Spoof Localized Surface Plasmons,"We propose wideband bandpass filters based on multipole resonances of spoof
localized surface plasmons (SLSPs). The resonance characteristics and geometric
tunability of SLSPs are investigated under microstrip excitations. Strong
coupling with interlayer microstrip lines is proposed to join discrete
multipole resonances into a continuous and flat passband. The SLSP filters
exhibit wide passbands in compact sizes and well-balanced shapes, while holding
satisfactory spurious rejection bands, group delays, and geometric tunability.
This work exposes the SLSPs' application potential in filters as novel
resonators.",1804.01294v1
2018-11-03,Photonic crystal-Microring resonators for tunable delay lines,"In this paper, a new design of optical delay line based on coupled ring
resonators in photonic crystals is proposed and analyzed by means of numerical
simulation in CST Microwave Studio. The performance of the proposed photonic
crystal ring resonator (PhCRR) based coupled resonant optical waveguide (CROW)
is compared to: point-defect cavity based coupled cavity waveguides (CCW) in
photonic crystal. microring resonator (MRR) based CROW. The suggested design
addresses compactness issues of the MRR CROW while offering normalized delay
values better than CCW and comparable to MRR CROW. The PhCRR CROW also enhances
design flexibility as the PhCRRs support multiple modes and thereby supporting
multi-channel transfer/delay application on a single device.",1811.07828v1
2018-11-20,Reducing parasitic resonances in particle accelerators components by broadband Higher Order Mode couplers,"In particle accelerator components, parasitic resonances must be reduced
because they heat up the equipment and cause beam instabilities. In this paper,
a method for designing and characterizing Higher Order Mode (HOM) couplers for
reducing such resonances in a broad bandwidth is proposed. A case study is
considered for a specific component, called QuattroTank, showing geometrical
discontinuities and thus causing significant electro-magnetic resonances.
Results of numerical simulation and experimental emulation prove the capability
of the proposed method to reduce the peaks and the $Q-factor of the resonances.",1811.08154v1
2020-07-23,Complex scaling : physics of unbound light nuclei and perspective,"The complex scaling method (CSM) is one of the most powerful methods of
describing the resonances with complex energy eigenstates, based on
non-Hermitian quantum mechanics. We present the basic application of CSM to the
properties of the unbound phenomena of light nuclei. In particular, we focus on
many-body resonant and non-resonant continuum states observed in unstable
nuclei. We also investigate the continuum level density (CLD) in the scattering
problem in terms of the Green's function with CSM. We discuss the explicit
effects of resonant and non-resonant contributions in CLD and transition
strength functions.",2007.12172v1
2020-07-24,Optimal Resonant Asymptotics of Wakefield Excitation in Plasma by Non-resonant Sequence of Relativistic Electron Bunches,"Resonant asymptotics of wakefield excitation in plasma by non-resonant
sequence of relativistic electron bunches has been numerically simulated. It
has been shown that in resonant asymptotics at optimal parameters the wakefield
is excited with the maximum growth rate and the amplitude of the excited
wakefield is the largest.",2007.12745v1
2010-05-14,Double resonances in Borromean heteronuclear triatomic systems,"We investigate the occurrence of Borromean three-body continuum s-wave
resonances, in an $\alpha\alpha\beta$ system for large negative two-body
scattering lengths. The energy and width are determined by a scaling function
with arguments given by energy ratios of the two-body virtual state subsystem
energies with the shallowest three-body bound state. The Borromean continuum
resonances emerging from Efimov states present a peculiar behavior for trapped
ultracold atoms near a Feshbach resonance: two resonances with equal energies
at different values of the scattering length. The corresponding three-body
recombination peaks should merge as the temperature is raised, with one moving
towards lower values of the scattering length as the other moves to larger
values.",1005.2576v1
2014-03-05,Locally Resonant Granular Chain,"We report the design and testing of a tunable and nonlinear mechanical
metamaterial, called locally resonant granular chain. It consists of a
one-dimensional array of hollow spherical particles in contact, containing
local resonators. The resonant particles are made of an aluminium outer
spherical shell and a steel inner mass connected by a polymeric plastic
structure acting as a spring. We characterize the linear spectra of the
individual particles and of one-dimensional arrays of particles using theory,
numerical analysis, and experiments. A wide band gap is observed as well as
tunability of the dispersive spectrum by changing the applied static load.
Finally, we experimentally explore the nonlinear dynamics of the resonant
particles. By using nonlinear acoustical techniques, we reveal a complex,
nonclassical nonlinear dynamics.",1403.1052v1
2014-03-26,Improving Dark Matter Axion Searches with Active Resonators,"Axions are a well motivated candidate for dark matter. The most sensitive
experiments searching for dark matter axions rely on the coupling of axions to
the electromagnetic resonances of a microwave cavity immersed in a strong
magnetic field. The sensitivity of the experiment is proportional to the Q of
the resonance that is coupled to axions. To date, the resonators used in axion
searches have all been passive, with Qs limited by power loss in the cavity
walls. I propose the use of active feedback resonators to increase the Q of
microwave cavity axion dark matter experiments by several orders of magnitude.
This should allow experiments to significantly increase the rate at which they
can test potential axion masses and couplings.",1403.6720v1
2018-05-16,Thermometry and memcapacitance with qubit-resonator system,"We study theoretically dynamics of a driven-dissipative qubit-resonator
system. Specifically, a transmon qubit is coupled to a transmission-line
resonator; this system is considered to be probed via a resonator, by means of
either continuous or pulsed measurements. Analytical results obtained in the
semiclassical approximation are compared with calculations in the semi-quantum
theory as well as with the previous experiments. We demonstrate that the
temperature dependence of the resonator frequency shift can be used for the
system thermometry and that the dynamics, displaying pinched-hysteretic curve,
can be useful for realization of memory devices, the quantum memcapacitors.",1805.06154v1
2011-11-15,Fano-like interference of plasmon resonances at a single rod-shaped nanoantenna,"Single metallic nanorods acting as half-wave antennas in the optical range
exhibit an asymmetric, multi-resonant scattering spectrum that strongly depends
on both their length and dielectric properties. Here we show that such spectral
features can be easily understood in terms of Fano-like interference between
adjacent plasmon resonances. On the basis of analytical and numerical results
for different geometries, we demonstrate that Fano resonances may appear for
such single-particle nanoantennas provided that interacting resonances overlap
in both spatial and frequency domains.",1111.3551v2
2012-01-27,Study of nuclear giant resonances using a Fermi-liquid method,"The nuclear giant resonances are studied by using a Fermi-liquid method, and
the nuclear collective excitation energies of different values of $l$ are
obtained, which are fitted with the centroid energies of the giant resonances
of spherical nuclei, respectively. In addition, the relation between the
isovector giant resonance and the corresponding isoscalar giant resonance is
discussed.",1201.5723v1
2014-05-15,"Ultra-high energy neutrinos and $W^{\prime}$, $Z^{\prime}$ gauge bosons at the Pierre Auger Observatory","A wide range of models beyond the Standard Model predict charged and neutral
resonances, generically called $W'$- and $Z'$-bosons, respectively. We present
a study of the impact of such resonances on the deep inelastic scattering of
ultra-high energy neutrinos as well as on the resonant charged current
$\bar\nu_e e^-$ scattering (Glashow resonance). We find that the effects of
such resonances can not be observed with the Pierre Auger Observatory or any
foreseeable upgrade of it.",1405.3756v1
2016-05-09,Epitaxial rhenium microwave resonators,"We have fabricated rhenium microwave resonators from epitaxial films. We have
used thin films of different structural quality depending on their growth
conditions. The resonators were coupled to a microwave transmission line which
allows the measurement of their resonance frequencies and internal quality
factors. From the resonance frequency at low temperature , the effective
penetration depth and the London penetration depth of the rhenium film are
extracted.",1605.02513v1
2016-05-26,Quantum Communication Between Remote Mechanical Resonators,"Mechanical resonators represent one of the most promising candidates to
mediate the interaction between different quantum technologies, bridging the
gap between efficient quantum computation and long-distance quantum
communication. In this letter, we introduce a novel interferometric scheme
where the interaction of a mechanical resonator with input/output quantum
pulses is controlled by an independent classical drive. We design protocols for
state teleportation and direct quantum state transfer, between distant
mechanical resonators. The proposed device, feasible with state-of-the-art
technology, can serve as building block for the implementation of long-distance
quantum networks of mechanical resonators.",1605.08327v1
2016-08-09,Multi-resonance split ring resonator structures at sub-terahertz frequencies,"This paper reports on the computational development of novel architectures of
multi-resonance Split Ring Resonators (SRRs), for efficient manipulation of
Terahertz (THz) frequency beams. The conceived resonators are based on both a
capacitive and inductive scheme. Simulation results have been obtained for a 60
GHz to 240 GHz operational bandwidth.",1608.02729v2
2016-12-12,Observation of Fano resonance using a coupled resonator metamaterial composed of meta-atoms arranged by double periodicity,"We studied the transmission characteristics of a planar metamaterial
consisting of an array of electric split-ring resonators (eSRRs) with double
periodicity. Because of coupling between different resonant modes induced by
different lattice periods in metamaterials with double periodicity, the
appearance of Fano resonance can be expected in the same manner as that in the
case of coupled classical oscillators. We fabricated complementary eSRRs and
verified that a Fano-like spectral shape appeared in the transmission spectra
of eSRRs with double periodicity in the terahertz region.",1612.03552v1
2016-12-28,Theory of adiabatic fountain resonance,"The theory of ""Adiabatic Fountain Resonance"" with superfluid $^4$He is
clarified. In this geometry a film region between two silicon wafers bonded at
their outer edge opens up to a central region with a free surface. We find that
the resonance in this system is not a Helmholtz resonance as claimed by
Gasparini and co-workers, but in fact is a fourth sound resonance. We postulate
that it occurs at relatively low frequency because the thin silicon wafers flex
appreciably from the pressure oscillations of the sound wave.",1612.08797v1
2017-06-05,Generalized magnetic mirrors,"We propose generalized magnetic mirrors that can be achieved by excitations
of sole electric resonances. Conventional approaches to obtain magnetic mirrors
rely heavily on exciting the fundamental magnetic dipoles, whereas here we
reveal that besides magnetic resonances, electric resonances of higher orders
can be also employed to obtain highly efficient magnetic mirrors. Based on the
electromagnetic duality, it is also shown that electric mirrors can be achieved
by exciting magnetic resonances. We provide direct demonstrations of the
generalized mirrors proposed in a simple system of one-dimensional periodic
array of all-dielectric wires, which may shed new light to many advanced fields
of photonics related to resonant multipolar excitations and interferences.",1706.01398v2
2017-10-12,Kinetic equation for systems with resonant captures and scatterings,"We study a Hamiltonian system of type describing a charged particle resonant
interaction with an electromagnetic wave. We consider an ensemble of particles
that repeatedly pass through the resonance with the wave, and study evolution
of the distribution function due to multiple scatterings on the resonance and
trappings (captures) into the resonance. We derive the corresponding kinetic
equation. Particular cases of this problem has been studied in our recent
papers [1, 2].",1710.04489v1
2017-10-18,Studies of Single Component Fermi Gas near a $P$-wave Resonance with Lowest Order Constrained Variational Method,"We study single component Fermi gas near a $p$-wave resonance with the lowest
order constrained variational (LOCV) method. We obtain the energy per particle
for the ground state of single component Fermi gas near a $p$-wave resonance
with LOCV method. We also calculate compressibility of the single component
Fermi gas near a $p$-wave resonance and it shows that near the $p$-wave
resonance, the system would lose its stability and collapse. The two $p$-wave
contacts are also obtained and their variation tendencies with interaction
strength are consistent with recent experimental results.",1710.06581v2
2017-12-29,"Traps in hadron spectroscopy: Thresholds, triangle singularities, etc","The knowledge of hadron spectrum is based on experimental observations of
hadronic resonances. The resonances are normally observed as peaks in certain
invariant mass distributions. However, neither is a peak necessarily due to the
presence of a resonance, nor does a resonance necessarily lead to a peak.
Kinematic singularities can also produce peaks. Here, we discuss such
possibilities and methods distinguishing genuine resonances from kinematic
effects.",1712.10126v2
2018-09-16,Nanoparticle lattices with electric and magnetic resonances [Prospective],"Lattice resonances in nanoparticle arrays recently have gained a lot of
attention because of the possibility to produce spectrally narrow resonant
features in transmission and reflection as well as significantly increase
absorption in the structures. Most of the efforts so far have been put to study
these lattice resonances in dipole approximation. However, the recent research
shows that higher multipoles not only produce resonant feature but are also
involved in cross-coupling, affect each other, and induce a magnetoelectric
response. In this Prospective, we review the recent achievements in studying of
interplay and coupling of different multipoles in periodic nanoparticle arrays
and share our vision on further progress of the field.",1809.05787v1
2018-10-08,On the optical nonreciprocity and slow light propagation in coupled spinning optomechanical resonators,"We study the optical transmission characteristics of pump-probe driven
spinning optomechanical ring resonators coupled in a series configuration.
After performing the steady-state analysis valid for an arbitrary number of
resonators, as an example, we discuss the two-resonator problem in detail.
Therein, we focus on how changing the optical Sagnac effect due to same or
opposite spinning directions of resonators can lead to enhanced, non-reciprocal
and delayed probe light transmission. This work can help in devising spin
degree of freedom based novel devices of manipulating light propagation in
quantum networks and quantum communication technologies.",1810.03709v1
2018-10-30,Subwavelength resonances of encapsulated bubbles,"The aim of this paper is to derive a formula for the subwavelength resonance
frequency of an encapsulated bubble with arbitrary shape in two dimensions.
Using Gohberg-Sigal theory, we derive an asymptotic formula for this resonance
frequency, as a perturbation away from the resonance of the uncoated bubble, in
terms of the thickness of the coating. The formula is numerically verified in
the case of circular bubbles, where the resonance can be efficiently computed
using the multipole method.",1810.12756v1
2019-06-05,The collisional resonance function in discrete-resonance quasilinear plasma systems,"A method is developed to analytically determine the resonance broadening
function in quasilinear theory, due to either Krook or Fokker-Planck scattering
collisions of marginally unstable plasma systems where discrete resonance
instabilities are excited without any mode overlap. It is demonstrated that a
quasilinear system that employs the calculated broadening functions reported
here systematically recovers the nonlinear growth rate and mode saturation
levels for near-threshold plasmas previously calculated from kinetic theory.
The distribution function is also calculated, which enables precise
determination of the characteristic collisional resonance width.",1906.01780v1
2019-06-28,Fano-like spectral features in nanodiamond solutions for biometric applications,"Fano resonance is a unique feature of interacting quantum systems, exhibiting
resonance shapes distinctively different from conventional symmetric resonance
curves. Recently, Fano resonances have been found in plasmonic nanoparticles,
photonic crystals, and electromagnetic metamaterials. Here we report Fano-like
photoluminiscence curves in nanodiamond solutions as a result of incoherent
combination of two or more scattering and fluorescence processes. We argue
that, analogously to Fano resonances, the steep asymmetric dispersion of the
photoluminiscence profile in nanodiamond solutions, in combination with
biologically-compatible spectral features characterizing nanodiamond
fluorescence, can find promising biometric applications in several areas such
as bio-sensors, bio-switches and bio-filters.",1907.00059v1
2019-10-24,Stimulated Four-Wave Mixing in Linearly Uncoupled Resonators,"We experimentally demonstrate stimulated four-wave mixing in two linearly
uncoupled integrated Si$_3$N$_4$ micro-resonators. In our structure the
resonance combs of each resonator can be tuned independently, with the energy
transfer from one resonator to the other occurring in the presence of a
nonlinear interaction. This method allows flexible and efficient on-chip
control of the nonlinear interaction, and is readily applicable to other
third-order nonlinear phenomena.",1910.11426v1
2020-01-15,Magnetic Feshbach resonances in $^{7}\text{Li}-^{133}\text{Cs}$ mixtures,"Motivated by the prospect of observing Efimov and Bose polaron physics in
ultracold mixtures of bosonic atoms with large mass imbalance, this work
investigates the magnetic Feshbach resonances between $^{7}\text{Li}$ and
$^{133}\text{Cs}$. The resonances are predicted at the 1 gauss level using the
model of Pires et al. [Phys. Rev. A, 90, 012710] obtained from experimental
observations of resonances between $^{6}\text{Li}$ and $^{133}\text{Cs}$. It is
found that a few resonances in a practical range of magnetic field intensity
could be used to tune the scattering length between $^{7}\text{Li}$ and
$^{133}\text{Cs}$ atoms. Opportunities for observing Efimov and Bose polaron
physics are discussed.",2001.05329v1
2020-02-10,Electron Spin Resonance spectroscopy with femtoliter detection volume,"We report electron spin resonance measurements of donors in silicon at
millikelvin temperatures using a superconducting $LC$ planar micro-resonator
and a Josephson Parametric Amplifier. The resonator includes a nanowire
inductor, defining a femtoliter detection volume. Due to strain in the
substrate, the donor resonance lines are heavily broadened. Single-spin to
photon coupling strengths up to $\sim 3~\text{kHz}$ are observed. The single
shot sensitivity is $120 \pm 24~$spins/Hahn echo, corresponding to $\approx 12
\pm 3$~spins$/\sqrt{\text{Hz}}$ for repeated acquisition.",2002.03669v1
2020-12-01,Excited $J^{--}$ meson resonances at the SU(3) flavor point from lattice QCD,"We present the first calculation within lattice QCD of excited light meson
resonances with $J^{PC} = 1^{--}$, $2^{--}$ and $3^{--}$. Working with an exact
SU(3) flavor symmetry, for the singlet representation of pseudoscalar-vector
scattering, we find two $1^{--}$ resonances, a lighter broad state and a
heavier narrow state, a broad $2^{--}$ resonance decaying in both $P$- and
$F$-waves, and a narrow $3^{--}$ state. We present connections to experimental
$\omega^\star_J, \phi^\star_J$ resonances decaying into $\pi \rho$,
$K\bar{K}^*$, $\eta \omega$ and other final states.",2012.00518v1
2020-12-03,Frequency span optimization for asymmetric resonance curve fitting,"The wide application of the modern resonant measurement techniques makes all
the steps of the measuring process, including data acquisition more efficient
and reliable. Here we investigate the multidimensional space of the parameters
to determine the optimum span for resonant measurements. The study concentrated
on experimental systems with standard performance and capabilities. We
determine the range of the optimum span for the resonant frequency and quality
factor by simulating and fitting resonant curves with different levels of
asymmetry.",2012.01921v2
2017-05-12,Polarizability Expressions for Predicting Resonances in Plasmonic and Mie Scatterers,"Polarizability expressions are commonly used in optics and photonics to model
the light scattering by small particles. Models based on Taylor series of the
scattering coefficients of the particles fail to predict the morphologic
resonances hosted by dielectric particles. Here, we propose to use the
factorization of the special functions appearing in the expression of the Mie
scattering coefficients to derive point-like models. These models can be
applied to reproduce both Mie resonances of dielectric particles and plasmonic
resonances of metallic particles. They provide simple but robust tools to
predict accurately the electric and magnetic Mie resonances in dielectric
particles.",1705.04488v1
2017-05-15,Resonance control of graphene drum resonator in nonlinear regime by standing wave of light,"We demonstrate the control of resonance characteristics of a drum type
graphene mechanical resonator in nonlinear oscillation regime by the
photothermal effect, which is induced by a standing wave of light between a
graphene and a substrate. Unlike the conventional Duffing type nonlinearity,
the resonance characteristics in nonlinear oscillation regime is modulated by
the standing wave of light despite a small variation amplitude. From numerical
calculations with a combination of equations of heat and motion with Duffing
type nonlinearity, this can be explained that the photothermal effect causes
delayed modulation of stress or tension of the graphene.",1705.05056v1
2017-09-04,Azbel'-Kaner-Like Cyclotron Resonance in a Two-Dimensional Electron System,"Resonant microwave absorption of a two-dimensional electron system in an
AlGaAs/GaAs heterostructure excited by a near-field technique was investigated.
Along with collective magnetoplasmon modes, we observed resonance that
precisely follows the cyclotron resonance (CR) position and revealed no signs
of collective plasma depolarization shift. We show that the discovered CR mode
is absent in the Faraday geometry, and is localized at the edge of the exciting
metal electrode. Such behavior points in favor of the single-particle
Azbel'-Kaner nature of the discovered resonance.",1709.00840v1
2018-03-05,Zero resonances for localised potentials,"This paper considers Hamiltonians with localised potentials and gives a
variational characterisation of resonant coupling parameters, which allow to
provide estimates for the first resonant parameter and in turn also to provide
bounds for resonant free regions. As application we provide a constructive
approach to calculate the first resonant parameter for Yukawa type potentials
in $\mathbb R^3$.",1803.01813v3
2018-03-12,Probing unconventional superconductivity in proximitized graphene by impurity scattering,"We demonstrate how potential impurities are a very powerful tool for
determining the pairing symmetry in graphene proximity-coupled to a
spin-singlet superconductor. All d-wave states are characterized by subgap
resonances, with spatial patterns clearly distinguishing between nodal and
chiral d-wave symmetry, while s-wave states have no subgap resonances. We also
find strong supergap impurity resonances associated with the normal state Dirac
point. Sub- and supergap resonances only interact at very low doping levels,
then causing suppression of the supergap resonances.",1803.04455v2
2018-06-06,Detection of emitter-resonator coupling strength in quantum Rabi model via an auxiliary resonator,"In this paper, we propose a theoretical scheme to detect the
emitter-resonator coupling strength in the ultra-strong coupling regime in the
quantum Rabi model via introducing an auxiliary resonator. We demonstrate the
total system as a two-mode Rabi model and obtain the ground state by the
transformed rotating wave approximation, which is shown to be superior to the
usually applied rotating wave approximation. Here, the coupling strength is
detected by monitoring the average excitation number in the auxiliary resonator
and the sensitivity of the detection scheme is discussed analytically.",1806.01971v2
2018-06-06,Nonlinear resonances generate large-scale vortices in the phase space in plasma systems,"It is well-known that the resonance phenomena can destroy the adiabatic
invariance and cause chaos and mixing. In the present paper we show that the
nonlinear wave-particle resonant interaction may cause the emergence of
large-scale coherent structures in the phase space. The combined action of the
drift due to nonlinear scattering on resonance and trapping (capture) into
resonance create a vortex-like structure, where the areas of particle
acceleration and deceleration are macroscopically separated. At the same time,
nonlinear scattering also creates a diffusion that causes mixing and
uniformization in around the vortex.",1806.02240v1
2018-08-16,Arbitrary state preparation of a mechanical resonator via controlled pulse shaping and projective measurement in a qubit-resonator interaction,"We introduce a protocol capable of generating a general measurement operator
for a mechanical resonator. The technique requires a qubit-resonator
interaction and uses a coherent pulse to drive qubit transitions. This is
followed by projective measurement of the qubit's energy, constraining the
resonator in a state that depends on the pulse shape. The freedom to choose a
pulse shape for the coherent drive enables an arbitrary position-basis
measurement operator. Using this measurement operator, we outline a two pulse
protocol that probabilistically generates a pure mechanical state with a
desired wavefunction, with near unit fidelity for realizable parameters.",1808.05666v1
2018-12-01,Time Asymptotic expansions of solution for fourth-order Schrödinger equation with zero resonance or eigenvalue,"In this paper, we first deduce the asymptotic expansions of resolvent of
$H=(-\Delta)^2+V$ with the presence of resonance or eigenvalue at the
degenerate zero threshold for $d\geq5$. In particular, we identify these
resonance spaces for full kinds of zero resonances. As a consequence, we then
establish the {\it time asymptotic expansions} and {\it Kato-Jensen estimates}
for the solution of fourth-order Schr\""odinger equation under the presence of
zero resonance or eigenvalue.",1812.00223v2
2018-12-22,Lattice resonances under oblique light incidence on nanoparticle array,"Ultra-thin optical structures, known as metasurfaces, have shown promising
light controlling capability at the nanoscale. In this paper, we study their
particular case, a periodic array of high-refractive-index nanoparticles with
electric and magnetic resonances. The main result of the work is a numerical
demonstration that the lattice effect in the periodic arrangement of
nanoparticles changes the resonance position even if the resonances are above
the diffraction wavelength (Rayleigh anomaly). We show that the disk resonance
changes can be achieved not only by varying periods of the array under normal
light incidence but also by changing the incident angle.",1812.09456v1
2019-01-09,Resonance-assisted tunneling in 4D normal-form Hamiltonians,"Nonlinear resonances in the classical phase space lead to a significant
enhancement of tunneling. We demonstrate that the double resonance gives rise
to a complicated tunneling peak structure. Such double resonances occur in
Hamiltonian systems with an at least four-dimensional phase space. To explain
the tunneling peak structure, we use the universal description of single and
double resonances by 4D normal-form Hamiltonians. By applying perturbative
methods, we reveal the underlying mechanism of enhancement and suppression of
tunneling and obtain excellent quantitative agreement. Using a minimal matrix,
we obtain model an intuitive understanding.",1901.02692v2
2019-01-16,Phase modulated pulse interferometry for simultaneous multi-channel ultrasound detection,"In optical detection of ultrasound, resonators with high Q-factors are often
used to maximize sensitivity. However, in order to perform parallel
interrogation, conventional interferometric techniques require an overlap
between the resonator spectra, which is difficult to achieve with high Q-factor
resonators. In this paper, a new method is developed for parallel interrogation
of optical resonators with non-overlapping spectra. The method is based on a
phase modulation scheme for pulse interferometry (PM-PI) and requires only a
single photodetector and sampling channel per ultrasound detector. Using PM-PI,
parallel ultrasound detection is demonstrated with four high Q-factor
resonators.",1901.05163v1
2019-02-21,First-order perturbation theory for material changes in the surrounding of open optical resonators,"The single-mode approximation of the resonant state expansion has proven to
give accurate first-order approximations of resonance shifts and linewidth
changes when modifying the material properties inside open optical resonators.
Here, we extend this first-order perturbation theory to modifications of the
material properties in the surrounding medium. As a side product of our
derivations, we retrieve the already known analytical normalization condition
for resonant states. We apply our theory to two example systems: A metallic
nanosphere and a one-dimensional photonic crystal slab.",1902.08120v1
2019-03-05,Strong nonreciprocity in modulated resonator chains through synthetic electric and magnetic fields,"We study nonreciprocity in spatiotemporally modulated 1D resonator chains
from the perspective of equivalent 2D resonator arrays with a synthetic
dimension and transverse synthetic electric and magnetic fields. The synthetic
fields are respectively related to temporal and spatial modulation of the
resonator chain, and we show that their combination can break transmission
reciprocity without additional elements. This nonreciprocal effect is analogous
to the Hall effect for charged particles. We experimentally implement chains of
2 and 3 spatiotemporally modulated resonators and measure over 58 dB of
isolation contrast.",1903.07408v1
2019-04-18,Inverse resonance scattering for on rotationally symmetric manifolds,"We discuss inverse resonance scattering for the Laplacian on a rotationally
symmetric manifold $M = (0,\infty) \times Y$ whose rotation radius is constant
outside some compact interval. The Laplacian on $M$ is unitarily equivalent to
a direct sum of one-dimensional Schr\""odinger operators with compactly
supported potentials on the half-line. We prove
  o Asymptotics of counting function of resonances at large radius
  o Inverse problem: The rotation radius is uniquely determined by its
eigenvalues and resonances. Moreover, there exists an algorithm to recover the
rotation radius from its eigenvalues and resonances.
  The proof is based on some non-linear real analytic isomorphism between two
Hilbert spaces.",1904.08908v1
2019-12-15,Angle-action variables for orbits trapped at a Lindblad resonance,"The conventional approach to orbit trapping at Lindblad resonances via a
pendulum equation fails when the parent of the trapped orbits is too circular.
The problem is explained and resolved in the context of the Torus Mapper and a
realistic Galaxy model. Tori are computed for orbits trapped at both the inner
and outer Lindblad resonances of our Galaxy. At the outer Lindblad resonance,
orbits are quasiperiodic and can be accurately fitted by torus mapping. At the
inner Lindblad resonance, orbits are significantly chaotic although far from
ergodic, and each orbit explores a small range of tori obtained by torus
mapping.",1912.07026v1
2020-03-18,New Cyclotron Resonances,"The possibilities and conditions of effective interaction, in particular
acceleration, of charged particles by the field of plane electromagnetic wave
in the presence of an external constant mag-netic field are considered. It is
shown that the well-known conditions of cyclotron resonances require
generalization. New conditions for the resonant interaction of charged
particles are for-mulated, which contain not only the strength of the external
magnetic field (as the well-known conditions of cyclotron resonances) but also
the field strength of the wave. strengths. It is shown that new resonance
conditions open up new possibilities for effective particle acceleration.",2003.08110v1
2020-05-09,Resonance enhancement of neutrino oscillations due to transition magnetic moments,"We prove that a resonance enhancement of neutrino oscillations in magnetic
field is possible due to transition magnetic moments and demonstrate that this
resonance is strictly connected to the neutrino polarization. To study the main
properties of this resonance, we obtain the probabilities of transitions
between neutrino states with definite flavor and helicity in inhomogeneous
electromagnetic field in the adiabatic approximation. Since the resonance is
present only when the adiabaticity condition is fulfilled, we also obtain and
discuss this condition.",2005.04503v2
2020-06-08,Resonance structure of $^{8}$Be with the two-cluster resonating group method,"A two-cluster microscopic model is applied to study elastic alpha-alpha
scattering and resonance structure of $^{8}$Be. The model is an algebraic
version of the Resonating Group Method, which makes use complete set of
oscillator functions to expand wave function of two-cluster system. Interaction
between clusters is determined by well-known semi-realistic nucleon-nucleon
potentials of Hasegawa-Nagata, Minnesota and Volkov. Detail analysis of
resonance wave functions is carried out in oscillator, coordinate and momentum
spaces. Effects of the Pauli principle on wave functions of the $^{8}$Be
continuous spectrum states are thoroughly studied.",2006.04525v1
2020-09-17,Exploring the di-$J/ψ$ resonances based on {\it{ab initio}} perturbative QCD,"We extend the nonrelativistic QCD framework to explore the nature of the
newly discovered di-$J/\psi$ resonances. Assuming them as either molecule-like
states or tetraquarks, we calculated their hadroproduction cross sections at
the LHC. We find that the observed resonances are most likely spin-2 particles,
and there should exist their spin-0 counterparts near these resonances. The
ratio of production cross sections of the observed resonances to the latent
spin-0 ones are also presented, which might help to distinguish molecule-like
states from tetraquarks.",2009.08376v3
2020-10-04,Resonant Processing of Instrumental Sound Controlled by Spatial Position,"We present an acoustic musical instrument played through a resonance model of
another sound. The resonance model is controlled in real time as part of the
composite instrument. Our implementation uses an electric violin, whose spatial
position modifies filter parameters of the resonance model. Simplicial
interpolation defines the mapping from spatial position to filter parameters.
With some effort, pitch tracking can also control the filter parameters. The
individual technologies -- motion tracking, pitch tracking, resonance models --
are easily adapted to other instruments.",2010.01572v1
2020-10-21,High-Q dielectric Mie-resonant nanostructures (a mini-review),"Future technologies underpinning high-performance optical communications,
ultrafast computations and compact biosensing will rely on densely packed
reconfigurable optical circuitry based on nanophotonics. For many years,
plasmonics was considered as the only available platform for nanoscale optics,
but the recently emerged novel field of Mie resonant metaphotonics provides
more practical alternatives for nanoscale optics by employing resonances in
high-index dielectric nanoparticles and structures. In this mini-review we
highlight some recent trends in the physics of dielectric Mie-resonant
nanostructures with high quality factor (Q factor) for efficient spatial and
temporal control of light by employing multipolar resonances and the bound
states in the continuum. We discuss a few applications of these concepts to
nonlinear optics, nanolasers, subwavelength waveguiding, and sensing.",2010.10854v1
2021-04-06,Husimi Functions for Coupled Optical Resonators,"Phase-space analysis has been widely used in the past for the study of
optical resonant systems. While it is usually employed to analyze the far-field
behaviour of resonant systems we focus here on its applicability to coupling
problems. By looking at the phase-space description of both the resonant mode
and the exciting source it is possible to understand the coupling mechanisms as
well as to gain insights and approximate the coupling behaviour with reduced
computational efforts. In this work we develop the framework for this idea and
apply it to a system of an asymmetric dielectric resonator coupled to a
waveguide.",2104.02368v1
2021-12-09,Precession resonances in hierarchical triple systems,"We describe a new kind of resonance occuring in relativistic three-body
hierarchical systems: the precession resonance, occuring when the relativistic
precession timescale of a binary equals the period of a distant perturber. We
find that, contrary to what most previous studies assume, it can lead to an
exponential increase of eccentricity of the binary even when relativistic
precession dominates the quadrupolar perturbation. The resonance may happen in
the observation band of LISA or change the eccentricity distribution of
triples. We discuss the physics of the resonance, showing that it mainly
depends on three parameters.",2112.05167v2
2022-02-07,Convolutional Neural Networks for Mode On-Demand High Finesse Optical Resonator Design,"We demonstrate the use of machine learning through convolutional neural
networks to solve inverse design problems of optical resonator engineering. The
neural network finds a harmonic modulation of a spherical mirror to generate a
resonator mode with a given target topology (""mode on-demand""). The procedure
allows us to optimize the shape of mirrors to achieve a significantly enhanced
coupling strength and cooperativity between a resonator photon and a quantum
emitter located at the center of the resonator. In a second example, a
double-peak mode is designed which would enhance the interaction between two
quantum emitters, e.g., for quantum information processing.",2202.03359v1
2022-02-15,Asymptotic analysis of subwavelength halide perovskite resonators,"Halide perovskites are promising materials with many significant applications
in photovoltaics and optoelectronics. In this paper, we use integral methods to
quantify the resonant properties of halide perovskite nano-particles. We prove
that, for arbitrarily small particles, the subwavelength resonant frequencies
can be expressed in terms of the eigenvalues of the Newtonian potential
associated with its shape. We also characterize the hybridized subwavelength
resonant frequencies of a dimer of two halide perovskite particles. Finally, we
examine the specific case of spherical resonators and demonstrate that our new
results are consistent with previous works.",2202.07274v1
2022-06-24,Meridional composite pulses for low-field magnetic resonance,"We discuss procedures for error-tolerant spin control in environments that
permit transient, large-angle reorientation of magnetic bias field. Short
sequences of pulsed, non-resonant magnetic field pulses in a laboratory-frame
meridional plane are derived. These are shown to have band-pass excitation
properties comparable to established amplitude-modulated, resonant pulses used
in high, static-field magnetic resonance. Using these meridional pulses, we
demonstrate robust $z$ inversion in proton ($^{1}$H) nuclear magnetic resonance
near earth's field.",2206.12025v1
2022-08-04,A home-lab experiment: resonance and sound speed using telescopic vacuum cleaner pipes,"We propose a home laboratory in which a telescopic vacuum cleaner pipe and a
smartphone are used to investigate sound speed and acoustic resonance. When the
pipe is hit or the hands clapped near one end the sound produced is registered
by a smartphone. By means of an appropriate application the resonant frequency
is obtained. Varying the pipe's length and registering the corresponding
resonant frequency allows to obtain the sound speed. This home-lab, first
proposed during covid19 pandemic, has been incorporated as a home challenge to
experiment with acoustic resonance in new normal times.",2208.02671v1
2022-11-15,A note on separation conditions of resonance sets in the instability analysis for high-frequency oscillations in geometric optics,"In this paper, we study the instability of highly-oscillating solutions to
semi-linear hyperbolic systems. A instability criterion was given in \cite{Lu}
under rather strong separation conditions of resonance sets: coupled resonance
sets are pairwise disjoint. Here we show that such separation conditions in
\cite{Lu} can be relaxed: one of the coupled non-transparent resonance sets is
allowed to intersect with at most two others. We obtain the same instability
criterion as in \cite{Lu}. Finally, we give some applications to coupled
Klein-Gordon systems with equal masses and nonlinear terms specified
particularly, where on the intersections of resonance sets, the related
interaction coefficients are non-transparent.",2211.07929v1
2022-12-19,Depletion-limited Kerr solitons in singly-resonant optical parametric oscillators,"We analyze the impact of pump depletion in the generation of cavity solitons
in a singly-resonant parametrical oscillator that includes a $\chi^{(3)}$
nonlinear section. We find an analytical expression that provides the soliton
existence region using variational methods, study the efficiency of energy
conversion, and compare it to a driven Kerr resonator modeled by the
Lugiato-Lefever equation. At high walk-off, solitons in singly-resonant optical
parametric oscillators are more efficient than those formed in a Kerr resonator
driven through a linear coupler.",2212.09493v1
2023-05-29,LLC type galvanic isolated resonant converter,"Resonant converters are often being used for high power and high voltage
applications to achieve high efficiency, high power density and low EMI. In
this paper, we will use a resonant converter for a completely different
application. We will take advantage of the Zero Voltage Switching (ZVS) and
operating in the vicinity of the series resonance to design a low power and
ultra-low noise galvanic isolated half bridge resonant DC-DC converter for
powering a medical amplifier. Under lower power we consider up to 6W (500mA @
12V). The DC-DC converter must meet the safety requirements of the standard IEC
60601.",2305.18132v1
2023-07-03,Complex translation methods and its application to resonances for quantum walks,"In this paper, some properties of resonances for multi-dimensional quantum
walks are studied. Resonances for quantum walks are defined as eigenvalues of
complex translated time evolution operators in the pseudo momentum space. For
some typical cases, we show some results of existence or nonexistence of
resonances. One is a perturbation of an elastic scattering of a quantum walk
which is an analogue of classical mechanics. Another one is a shape resonance
model which is a perturbation of a quantum walk with a non-penetrable barrier.",2307.00962v3
2023-08-11,Manipulating the Quasi-Normal Modes of Radially Symmetric Resonators,"We derive two methods for simultaneously controlling the resonance frequency,
linewidth and multipolar nature of the resonances of radially symmetric
structures. Firstly, we formulate an eigenvalue problem for a global shift in
the permittivity of the structure to place a resonance at a particular complex
frequency. Next, we employ quasi-normal mode perturbation theory to design
radially graded structures with resonances at desired frequencies.",2308.06179v1
2023-10-31,Radiating Resonances for the Helmholtz Equation and Thin 2D Waveguide Detection,"We investigate the radiating resonances for the Helmholtz equation in the two
dimensional space in the presence of an unbounded waveguide with a high
contrast index of refraction. Using a suitable asymptotic analysis of the
Green's function of the problem, we describe when these radiating resonances
appear, and we exploit these resonances to identify the thickness, location,
and index of refraction of the waveguide. We propose a suitable numerical
reconstruction algorithm that requires observations in a multifrequency range
containing the first radiating resonance.",2311.00132v1
2023-11-22,A blueprint for truncation resonance placement in elastic periodic lattices with unit cell asymmetry,"Elastic periodic lattices act as mechanical filters of incident vibrational
loads. By and large, they forbid wave propagation within bandgaps and resonate
outside them. However, they often encounter `truncation resonances' inside
bandgaps when certain conditions are met. This study provides an
all-encompassing blueprint for the design and selective placement of truncation
resonances in elastic periodic lattices, integrating all factors that play a
role in the onset of truncation resonances and shaping the finite lattice's
response, from unit cell configuration, mass and stiffness contrasts, to types
and symmetry of boundary conditions.",2311.13698v1
2023-12-16,A Pairing Formula for Resonant States on Finite Regular Graphs,"On a finite regular graph, (co)resonant states are eigendistributions of the
transfer operator associated to the shift on one-sided infinite
non-backtracking paths. We introduce two pairings of resonant and coresonant
states, the vertex pairing which involves only the dependence on the
initial/terminal vertex of the path, and the geodesic pairing which is given by
integrating over all geodesics the evaluation of the coresonant state on the
first half of the geodesic times the resonant state on the second half. The
main result is that these two pairings coincide up to a constant which depends
on the resonance, i.e. the corresponding eigenvalue of the transfer operator.",2312.10509v1
2024-02-09,"Radiative neutron capture rate of $^{11}$B$(n,γ)^{12}$B reaction from the Coulomb dissociation of $^{12}$B","We calculate the $^{11}$B$(n,\gamma)^{12}$B reaction rate, an important
constituent in nucleosynthesis networks, contributed by resonant as well as
non-resonant capture. For the resonant rate, we use the narrow resonance
approximation whereas the non-resonant contribution is calculated with the
Coulomb dissociation method for which we use finite-range distorted wave Born
approximation theory. We then compare our calculated rate of
$^{11}$B$(n,\gamma)^{12}$B reaction with those reported earlier and with other
charged particle reactions on $^{11}$B.",2402.06755v1
2001-06-14,Partial Averaging and Resonance Trapping in a Restricted Three-Body System,"Based on the value of the orbital eccentricity of a particle and also its
proximity to the exact resonant orbit in a three-body system, the Pendulum
Approximation (Dermott & Murray 1983) or the Second Fundamental Model of
Resonance (Andoyer 1903; Henrard & Lemaitre 1983) are commonly used to study
the motion of that particle near its resonance state. In this paper, we present
the method of partial averaging as an analytical approach to study the
dynamical evolution of a body near a resonance. To focus attention on the
capabilities of this technique, a restricted, circular and planar three-body
system is considered and the dynamics of its outer planet while captured in a
resonance with the inner body is studied. It is shown that the first-order
partially averaged system resembles a mathematical pendulum whose librational
motion can be viewed as a geometrical interpretation of the resonance capture
phenomenon. The driving force of this pendulum corresponds to the gravitational
attraction of the inner body and its contribution, at different resonant
states, is shown to be proportional to e^s, where s is the order of the
resonance and e is the orbital eccentricity of the outer planet. As examples of
such systems, the cases of (1:1), (1:2) and (1:3) resonances are discussed and
the results are compared with known planetary systems such as the
Sun-Jupiter-Trojan asteroids.",0106264v1
2005-03-31,The role of resonances in barred galaxies,"The dynamics of the inner disk of many galaxies is dominated by bars. As a
result, resonances between the bar and the disk become an important factor. In
order to detect resonances, we measure angular and radial frequencies of
individual orbits in N-body models of barred galaxies. In our simulations with
several million particles, stellar disks are immersed in live halos of dark
matter. A bar forms spontaneously and interacts with the disk through
resonances. We detect 9 of them. The corotation (CR) and the inner Lindblad
resonance (ILR) are the most significant. The spatial distributions of
particles trapped at these resonances show that ILR is not localized at a given
radius. Particles trapped at ILR lie along the bar spanning a wide range of
radii. On the other hand, particles at the corotation resonance form a ring
around the corotation radius. We study how orbits evolve near corotation and
how they are trapped. When an orbit is getting trapped, it evolves strongly,
but after that there is little evolution. Those trapped orbits circulate along
the corotation ring or librate around a stable lagragian point. The same
technique is applied to study resonances in the halo. The bar interacts
strongly with the halo particles that stay close to the disk. We find the
corotation resonance and the inner Lindblad resonance for halo particles.",0503710v2
1999-12-07,Quantum Resonances and Regularity Islands in Quantum Maps,"We study analytically as well as numerically the dynamics of a quantum map
near a quantum resonance of an order q. The map is embedded into a continuous
unitary transformation generated by a time-independent quasi-Hamiltonian. Such
a Hamiltonian generates at the very point of the resonance a local gauge
transformation described the unitary unimodular group SU(q). The resonant
energy growth of is attributed to the zero Liouville eigenmodes of the
generator in the adjoint representation of the group while the non-zero modes
yield saturating with time contribution. In a vicinity of a given resonance,
the quasi-Hamiltonian is then found in the form of power expansion with respect
to the detuning from the resonance. The problem is related in this way to the
motion along a circle in a (q^2-1)-component inhomogeneous ""magnetic"" field of
a quantum particle with $q$ intrinsic degrees of freedom described by the SU(q)
group. This motion is in parallel with the classical phase oscillations near a
non-linear resonance. The most important role is played by the resonances with
the orders much smaller than the typical localization length, q << l. Such
resonances master for exponentially long though finite times the motion in some
domains around them. Explicit analytical solution is possible for a few lowest
and strongest resonances.",9912009v1
2005-10-10,Quantum master equation descriptions of a nanomechanical resonator coupled to a single-electron transistor,"We analyse the quantum dynamics of a nanomechanical resonator coupled to a
normal-state single-electron transistor (SET). Starting from a microscopic
description of the system, we derive a master equation for the SET island
charge and resonator which is valid in the limit of weak electro-mechanical
coupling. Using this master equation we show that, apart from brief transients,
the resonator always behaves like a damped harmonic oscillator with a shifted
frequency and relaxes into a thermal-like steady state. Although the behaviour
remains qualitatively the same, we find that the magnitude of the resonator
damping rate and frequency shift depend very sensitively on the relative
magnitudes of the resonator period and the electron tunnelling time. Maximum
damping occurs when the electrical and mechanical time-scales are the same, but
the frequency shift is greatest when the resonator moves much more slowly than
the island charge. We then derive reduced master equations which describe just
the resonator dynamics. By making slightly different approximations, we obtain
two different reduced master equations for the resonator. Apart from minor
differences, the two reduced master equations give rise to a consistent picture
of the resonator dynamics which matches that obtained from the master equation
including the SET island charge.",0510236v1
2006-07-25,Adiabatic theorems for quantum resonances,"We study the adiabatic time evolution of quantum resonances over time scales
which are small compared to the lifetime of the resonances. We consider three
typical examples of resonances: The first one is that of shape resonances
corresponding, for example, to the state of a quantum-mechanical particle in a
potential well whose shape changes over time scales small compared to the
escape time of the particle from the well. Our approach to studying the
adiabatic evolution of shape resonances is based on a precise form of the
time-energy uncertainty relation and the usual adiabatic theorem in quantum
mechanics. The second example concerns resonances that appear as isolated
complex eigenvalues of spectrally deformed Hamiltonians, such as those
encountered in the N-body Stark effect. Our approach to study such resonances
is based on the Balslev-Combes theory of dilatation-analytic Hamiltonians and
an adiabatic theorem for nonnormal generators of time evolution. Our third
example concerns resonances arising from eigenvalues embedded in the continuous
spectrum when a perturbation is turned on, such as those encountered when a
small system is coupled to an infinitely extended, dispersive medium. Our
approach to this class of examples is based on an extension of adiabatic
theorems without a spectral gap condition. We finally comment on resonance
crossings, which can be studied using the last approach.",0607054v2
2007-08-20,Three-State Feshbach Resonances Mediated By Second-Order Couplings,"We present an analytical study of three-state Feshbach resonances induced by
second-order couplings. Such resonances arise when the scattering amplitude is
modified by the interaction with a bound state that is not directly coupled to
the scattering state containing incoming flux. Coupling occurs indirectly
through an intermediate state. We consider two problems: (i) the intermediate
state is a scattering state in a distinct open channel; (ii) the intermediate
state is an off-resonant bound state in a distinct closed channel. The first
problem is a model of electric-field-induced resonances in ultracold collisions
of alkali metal atoms [Phys. Rev. A 75, 032709 (2007)] and the second problem
is relevant for ultracold collisions of complex polyatomic molecules, chemical
reaction dynamics, photoassociation of ultracold atoms, and electron - molecule
scattering. Our analysis yields general expressions for the energy dependence
of the T-matrix elements modified by three-state resonances and the dependence
of the resonance positions and widths on coupling amplitudes for the
weak-coupling limit. We show that the second problem can be generalized to
describe resonances induced by indirect coupling through an arbitrary number of
sequentially coupled off-resonant bound states and analyze the dependence of
the resonance width on the number of the intermediate states.",0708.2638v2
2008-05-12,Turbulence in Extrasolar Planetary Systems Implies that Mean Motion Resonances are Rare,"This paper considers the effects of turbulence on mean motion resonances in
extrasolar planetary systems and predicts that systems rarely survive in a
resonant configuration. A growing number of systems are reported to be in
resonance, which is thought to arise from the planet migration process. If
planets are brought together and moved inward through torques produced by
circumstellar disks, then disk turbulence can act to prevent planets from
staying in a resonant configuration. This paper studies this process through
numerical simulations and via analytic model equations, where both approaches
include stochastic forcing terms due to turbulence. We explore how the
amplitude and forcing time intervals of the turbulence affect the maintenance
of mean motion resonances. If turbulence is common in circumstellar disks
during the epoch of planet migration, with the amplitudes indicated by current
MHD simulations, then planetary systems that remain deep in mean motion
resonance are predicted to be rare. More specifically, the fraction of resonant
systems that survive over a typical disk lifetime of 1 Myr is of order 0.01. If
mean motion resonances are found to be common, their existence would place
tight constraints on the amplitude and duty cycle of turbulent fluctuations in
circumstellar disks. These results can be combined by expressing the expected
fraction of surviving resonant systems in the approximate form P_b = C /
N_{orb}^{1/2}, where the dimensionless parameter C = 10 - 50 and where N_{orb}
is the number of orbits for which turbulence is active.",0805.1681v1
2008-06-03,Quark models of dibaryon resonances in nucleon-nucleon scattering,"We look for $\Delta\Delta$ and $N\Delta$ resonances by calculating $NN$
scattering phase shifts of two interacting baryon clusters of quarks with
explicit coupling to these dibaryon channels. Two phenomenological
nonrelativistic chiral quark models giving similar low-energy $NN$ properties
are found to give significantly different dibaryon resonance structures. In the
chiral quark model (ChQM), the dibaryon system does not resonate in the $NN$
$S$-waves, in agreement with the experimental SP07 $NN$ partial-wave scattering
amplitudes. In the quark delocalization and color screening model (QDCSM), the
$S$-wave NN resonances disappear when the nucleon size $b$ falls below 0.53 fm.
Both quark models give an $IJ^P = 03^+$ $\Delta\Delta$ resonance. At $b=0.52
$fm, the value favored by baryon spectrum, the resonance mass is 2390 (2420)
MeV for the ChQM with quadratic (linear) confinement, and 2360 MeV for the
QDCSM. Accessible from the $^3D_3^{NN}$ channel, this resonance is a promising
candidate for the known isoscalar ABC structure seen more clearly in the
$pn$$\to $$d\pi\pi$ production cross section at 2410 MeV in the recent
preliminary data reported by the CELSIUS-WASA Collaboration. In the isovector
dibaryon sector, our quark models give a bound or almost bound
$^5S_2^{\Delta\Delta}$ state that can give rise to a $^1D_2^{NN}$ resonance.
None of the quark models used has bound $N\Delta$ $P$-states that might
generate odd-parity resonances.",0806.0458v2
2010-11-22,Hamiltonian model of capture into mean motion resonance,"Mean motion resonances are a common feature of both our own Solar System and
of extrasolar planetary systems. Bodies can be trapped in resonance when their
orbital semi-major axes change, for instance when they migrate through a
protoplanetary disc. We use a Hamiltonian model to thoroughly investigate the
capture behaviour for first and second order resonances. Using this method, all
resonances of the same order can be described by one equation, with
applications to specific resonances by appropriate scaling. We focus on the
limit where one body is a massless test particle and the other a massive
planet. We quantify how the the probability of capture into a resonance depends
on the relative migration rate of the planet and particle, and the particle's
eccentricity. Resonant capture fails for high migration rates, and has
decreasing probability for higher eccentricities, although for certain
migration rates, capture probability peaks at a finite eccentricity. We also
calculate libration amplitudes and the offset of the libration centres for
captured particles, and the change in eccentricity if capture does not occur.
Libration amplitudes are higher for larger initial eccentricity. The model
allows for a complete description of a particle's behaviour as it successively
encounters several resonances. The model is applicable to many scenarios,
including (i) Planet migration through gas discs trapping other planets or
planetesimals in resonances; (ii) Planet migration through a debris disc; (iii)
Dust migration through PR drag. Full details can be found in
\cite{2010submitted}. (Abridged)",1011.4804v1
2011-01-12,Scattering by coupled resonating elements in air,"Scattering by (a) a single composite scatterer consisting of a concentric
arrangement of an outer N-slit rigid cylinder and an inner cylinder which is
either rigid or in the form of a thin elastic shell and (b) by a finite
periodic array of these scatterers in air has been investigated analytically
and through laboratory experiments. The composite scatterer forms a system of
coupled resonators and gives rise to multiple low frequency resonances. The
corresponding analytical model employs polar angle dependent boundary
conditions on the surface of the N-slit cylinder. The solution inside the slits
assumes plane waves. It is shown also that in the low-frequency range the
N-slit rigid cylinder can be replaced by an equivalent fluid layer. Further
approximations suggest a simple square root dependence of the resonant
frequencies on the number of slits and this is confirmed by data. The observed
resonant phenomena are associated with Helmholtz-like behaviour of the
resonator for which the radius and width of the openings are much smaller than
the wavelength. The problem of scattering by a finite periodic array of such
coupled resonators in air is solved using multiple scattering techniques. The
resulting model predicts band-gap effects resulting from the resonances of the
individual composite scatterers below the first Bragg frequency . Predictions
and data confirm that use of coupled resonators results in substantial
insertion loss peaks related to the resonances within the concentric
configuration. In addition, for both scattering problems experimental data,
predictions of the analytical approach and predictions of the equivalent fluid
layer approximations are compared in the low-frequency interval.",1101.2332v1
2012-09-21,Influence of external magnetic and laser radiation fields on Feshbach resonances in collision of atoms,"We study collision of two atoms with formation of Feshbach resonance at
combined interaction with the external magnetic field and laser radiation. In
cases of one- and two-photon resonances of laser radiation with two discrete
vibrational molecular levels, we show that Feshbach resonances appear at
interaction of external magnetic field with dressed states formed via
Autler-Townes effect. In addition, in case of one-photon resonance the lower
vibrational molecular state is coupled by laser radiation with the continuum of
the elastic channel and forms laser-induced Feshbach resonance via both
Autler-Townes effect and LICS mechanism. We study the combined process of
formation of Feshbach resonances; this enables the control of Feshbach
resonance by varying the magnetic field and intensity and frequency of laser
radiation. We obtain the cross-sections of elastic and inelastic scattering and
show that quenching of resonance occurs at the energy equal to that of the
systems ground state. Dependence of the cross-sections on the magnetic field
and laser intensity is examined in detail. In all considered cases, the
scattering length is obtained depending on the magnetic and laser fields are
studied. In the absence of magnetic interaction if the hyperfine substates of
the quasibound state in the closed channel and those of individual colliding
atoms in the open channel are the same, Feshbach resonances may arise via weak
interaction between nuclear and electronic motions, which leads to transitions
between electronic states. The obtained results can be employed in new studies
of collisions of cold atoms, e.g., of alkali metal atoms and for interpretation
of new experiments in BECs.",1209.4725v1
2012-12-12,Shape resonances in multi-condensate granular superconductors formed by networks of nanoscale-striped puddles,"A characteristic feature of a superconductor made of multiple condensates is
the possibility of the shape resonances in superconducting gaps. Shape
resonances belong to class of Fano resonances in configuration interaction
between open and closed scattering channels. The Shape resonances arise because
of the exchange interaction, a Josephson-like term, for transfer of pairs
between different condensates in different Fermi surface spots in the special
cases where at least one Fermi surface is near a 2.5 Lifshitz topological
transition. We show that tuning the shape resonances show first, the gap
suppression (like a Fano anti-resonance) driven by configuration interaction
between a BCS condensate and a BEC-like condensate, and second, the gap
amplification (like a Fano resonance) driven by configuration interaction
between BCS condensates in large and small Fermi surfaces. Shape resonances
usually occur in granular nanoscale complex matter (called superstripes)
because of the lattice instability near a 2.5 Lifshitz transition in presence
of interactions. Using a new imaging method, scanning nano-X-ray diffraction,
we have shown the generic formation in high temperature superconductors of a
granular superconducting networks made of striped puddles formed by ordered
oxygen interstitials or ordered local lattice distortions (like static short
range charge density waves). In the superconducting puddles the chemical
potential is tuned to a shape resonance in superconducting gaps and the maximum
Tc occurs where the puddles form scale free superconducting networks.",1212.2733v1
2012-12-21,Percolation transition in the kinematics of nonlinear resonance broadening in Charney-Hasegawa-Mima model of Rossby wave turbulence,"We study the kinematics of nonlinear resonance broadening of interacting
Rossby waves as modelled by the Charney-Hasegawa-Mima equation on a biperiodic
domain. We focus on the set of wave modes which can interact quasi-resonantly
at a particular level of resonance broadening and aim to characterise how the
structure of this set changes as the level of resonance broadening is varied.
The commonly held view that resonance broadening can be thought of as a
thickening of the resonant manifold is misleading. We show that in fact the set
of modes corresponding to a single quasi-resonant triad has a nontrivial
structure and that its area in fact diverges for a finite degree of broadening.
We also study the connectivity of the network of modes which is generated when
quasi-resonant triads share common modes. This network has been argued to form
the backbone for energy transfer in Rossby wave turbulence. We show that this
network undergoes a percolation transition when the level of resonance
broadening exceeds a critical value. Below this critical value, the largest
connected component of the quasi-resonant network contains a negligible
fraction of the total number of modes in the system whereas above this critical
value a finite fraction of the total number of modes in the system are
contained in the largest connected component. We argue that this percolation
transition should correspond to the transition to turbulence in the system.",1212.5336v1
2013-03-12,Resonant Behavior of Comet Halley and the Orionid Stream,"Comet 1P/Halley has the unique distinction of having a very comprehensive set
of observational records for almost every perihelion passage from 240 B.C. This
has helped to constrain theoretical models pertaining to its orbital evolution.
Many previous works have shown the active role of mean motion resonances in the
evolution of various meteoroid streams. Here we look at how various resonances,
especially the 1:6 and 2:13 mean motion resonances with Jupiter, affect comet
1P/Halley and thereby enhance the chances of meteoroid particles getting
trapped in resonance, leading to meteor outbursts in some particular years.
Comet Halley itself librated in the 2:13 resonance from 240 B.C. to 1700 A.D.
and in the 1:6 resonance from 1404 B.C. to 690 B.C., while stream particles can
survive for timescales of the order of 10,000 years and 1,000 years in the 1:6
and 2:13 resonances respectively. This determines the long term dynamical
evolution and stream structure, influencing the occurrence of Orionid
outbursts. Specifically we are able to correlate the occurrence of enhanced
meteor phenomena seen between 1436-1440, 1933-1938 & 2006-2010 with the 1:6
resonance and meteor outbursts in 1916 & 1993 with the 2:13 resonance. Ancient
as well as modern observational records agree with these theoretical
simulations to a very good degree.",1303.2928v2
2013-04-19,Periodicity of resonant tunneling current induced by the Stark resonances in semiconductor nanowire,"The modification of the electronic current resulting from Stark resonances
has been studied for the semiconductor nanowire with the double-barrier
structure. Based on the calculated current-voltage characteristics we have
shown that the resonant tunneling current is a periodic function of the width
of the spacer layer. We have also demonstrated that the simultaneous change of
the source-drain voltage and the voltage applied to the gate located near the
nanowire leads to almost periodic changes of the resonant tunneling current as
a function of the source-drain and gate voltages. The periodic properties of
the resonant tunneling current result from the formation of the Stark resonance
states. If we change the electric field acting in the nanowire, the Stark
states periodically acquire the energies from the transport window and enhance
the tunneling current in a periodic manner. We have found that the separations
between the resonant current peaks on the source-drain voltage scale can be
described by a slowly increasing linear function of the Stark state quantum
number. This allows us to identify the quantum states that are responsible for
the enhancement of the resonant tunneling. We have proposed a method of the
experimental observation of the Stark resonances in semiconductor
double-barrier heterostructures.",1304.5393v2
2013-05-28,Dynamical analysis of the Gliese-876 Laplace resonance,"The existence of multiple planetary systems involved in mean motion
conmensurabilities has increased significantly since the Kepler mission.
Although most correspond to 2-planet resonances, multiple resonances have also
been found. The Laplace resonance is a particular case of a three-body
resonance where the period ratio between consecutive pairs is n_1/n_2 near to
n_2/n_3 near to 2/1. It is not clear how this triple resonance can act in order
to stabilize (or not) the systems.
  The most reliable extrasolar system located in a Laplace resonance is GJ876
because it has two independent confirmations. However best-fit parameters were
obtained without previous knowledge of resonance structure and no exploration
of all the possible stable solutions for the system where done.
  In the present work we explored the different configurations allowed by the
Laplace resonance in the GJ876 system by varying the planetary parameters of
the third outer planet. We find that in this case the Laplace resonance is a
stabilization mechanism in itself, defined by a tiny island of regular motion
surrounded by (unstable) highly chaotic orbits. Low eccentric orbits and mutual
inclinations from -20 to 20 degrees are compatible with the observations. A
definite range of mass ratio must be assumed to maintain orbital stability.
Finally we give constrains for argument of pericenters and mean anomalies in
order to assure stability for this kind of systems.",1305.6768v1
2014-07-31,Effect of pairing fluctuations on the spin resonance in Fe-based superconductors,"The spin resonance observed in the inelastic neutron scattering data on
Fe-based superconductors has played a prominent role in the quest for
determining the symmetry of the order parameter in these compounds. Most
theoretical studies of the resonance employ an RPA-type approach in the
particle-hole channel and associate the resonance in the spin susceptibility
$\chi_S (\mathbf{q}, \omega)$ at momentum ${\bf Q} = (\pi,\pi)$ with the
spin-exciton of an $s^{+-}$ superconductor, pulled below $2\Delta$ by residual
attraction associated with the sign change of the gap between Fermi points
connected by ${\bf Q}$. Here we explore the effect of fluctuations in the
particle-particle channel on the spin resonance. Particle-particle and
particle-hole channels are coupled in a superconductor and to what extent the
spin resonance can be viewed as a particle-hole exciton needs to be addressed.
In the case of purely repulsive interactions we find that the particle-particle
channel at total momentum ${\bf Q}$ (the $\pi $channel) contributes little to
the resonance. However, if the interband density-density interaction is
attractive and the $\pi-$resonance is possible on its own, along with the
spin-exciton, we find a much stronger shift of the resonance frequency from the
position of the would-be spin-exciton resonance. We also show that the expected
double-peak structure in this situation does not appear because of the strong
coupling between particle-hole and particle-particle channels, and $\mathrm{Im}
\chi_S ({\bf Q}, \omega)$ displays only a single peak.",1408.0021v1
2014-11-14,Broadband resonances in ITO nanorod arrays,"In the nanophotonics community, there is an active discussion regarding the
origin of the selective absorption/scattering of light by the resonances with
nanorod arrays. Here we report a study of the resonances in ordered
indium-tin-oxide (ITO) nanorod arrays resulted from the waveguide modes. We
discover that with only 2.4% geometrical coverage, the micron-length nanorod
arrays strongly interact with light across an extra-wide band from visible to
mid-infrared resulting in less than 10% transmission. Simulations show
excellent agreement with our experimental observation. Near-field profile
obtained from simulation reveals the electric field is mainly localized on the
surfaces of the nanorods at all the resonances. Theoretical analysis is then
applied to explain the resonances and it was found that the resonances in the
visible are different from those in the infrared. When the light arrives at the
array, part of the light wave propagates through the free space in between the
nanorods and part of the wave is guided inside the nanorods and the phase
difference at the ends of the rod interactions forms the basis of the
resonances in the visible region; while the resonances in the infrared are
Fabry-Perot resonances of the surface guided waves between the two ends of the
nanorods. The simple analytical formulae developed predict the spectral
positions of these resonances well. This information can be used to design
devices like wavelength-selective photodetector, modulators, and nanorod-based
solar cells.",1411.3767v2
2015-01-14,Long-lived Chaotic Orbital Evolution of Exoplanets in Mean Motion Resonances with Mutual Inclinations,"We present N-body simulations of resonant planets with inclined orbits that
show chaotically evolving eccentricities and inclinations that can persist for
at least 10 Gyr. A wide range of behavior is possible, from fast, low amplitude
variations to systems in which eccentricities reach 0.9999 and inclinations
179.9 degrees. While the orbital elements evolve chaotically, at least one
resonant argument always librates. We show that the HD 73526, HD 45364 and HD
60532 systems may be in chaotically-evolving resonances. Chaotic evolution is
apparent in the 2:1, 3:1 and 3:2 resonances, and for planetary masses from
lunar- to Jupiter-mass. In some cases, orbital disruption occurs after several
Gyr, implying the mechanism is not rigorously stable, just long-lived relative
to the main sequence lifetimes of solar-type stars. Planet-planet scattering
appears to yield planets in inclined resonances that evolve chaotically in
about 0.5% of cases. These results suggest that 1) approximate methods for
identifying unstable orbital architectures may have limited applicability, 2)
the observed close-in exoplanets may be produced during the high eccentricity
phases induced by inclined resonances, 3) those exoplanets' orbital planes may
be misaligned with the host star's spin axis, 4) systems with resonances may be
systematically younger than those without, 5) the distribution of period ratios
of adjacent planets detected via transit may be skewed due to inclined
resonances, and 6) potentially habitable planets in resonances may have
dramatically different climatic evolution than the Earth. The GAIA spacecraft
is capable of discovering giant planets in these types of orbits.",1501.03231v1
2015-01-26,A study of the main resonances outside the geostationary ring,"We investigate the dynamics of satellites and space debris in external
resonances, namely in the region outside the geostationary ring. Precisely, we
focus on the 1:2, 1:3, 2:3 resonances, which are located at about 66 931.4 km,
87 705.0 km, 55 250.7 km, respectively. Some of these resonances have been
already exploited in space missions, like XMM-Newton and Integral.
  Our study is mainly based on a Hamiltonian approach, which allows us to get
fast and reliable information on the dynamics in the resonant regions.
Significative results are obtained even by considering just the effect of the
geopotential in the Hamiltonian formulation. For objects (typically space
debris) with high area-to-mass ratio the Hamiltonian includes also the effect
of the solar radiation pressure. In addition, we perform a comparison with the
numerical integration in Cartesian variables, including the geopotential, the
gravitational attraction of Sun and Moon, and the solar radiation pressure.
  We implement some simple mathematical tools that allows us to get information
on the terms which are dominant in the Fourier series expansion of the
Hamiltonian around a given resonance, on the amplitude of the resonant islands
and on the location of the equilibrium points. We also compute the Fast
Lyapunov Indicators, which provide a cartography of the resonant regions,
yielding the main dynamical features associated to the external resonances. We
apply these techniques to analyze the 1:2, 1:3, 2:3 resonances; we consider
also the case of objects with large area-to-mass ratio and we provide an
application to the case studies given by XMM-Newton and Integral.",1501.06273v1
2015-09-03,"Microspherical photonics: Giant resonant light forces, spectrally resolved optical manipulation, and coupled modes of microcavity arrays","In this dissertation novel resonant propulsion of dielectric microspheres is
studied with the goal of sorting spheres with identical resonances, which are
critical for developing microspherical photonics. First, evanescent field
couplers were developed by fixing tapered microfibers in mechanically robust
platforms. The tapers were obtained by chemical etching techniques. Using these
platforms, WGMs modal numbers, coupling regimes and quality factors were
determined for various spheres and compared with theory. Second, the
spectroscopic properties of photonic molecules formed by spheres with better
than 0.05% uniformity of WGM resonances were studied. It was shown that various
spatial configurations of coupled-cavities present relatively stable mode
splitting patterns in the fiber transmission spectra which can be used as
spectral signatures to distinguish such photonic molecules. The third part is
the study of giant resonant propulsion forces exerted on microspheres. This
effect was observed in suspensions of polystyrene spheres with sufficiently
large diameters. By integrating optical tweezers for individual sphere
manipulation, the wavelength detuning between a tunable laser and WGMs in each
of the spheres was precisely controlled. Resonant enhancement of optical forces
was directly demonstrated in experiments. The spectral shape, position and
magnitude of the observed propulsion force peaks were explained by efficient
transfer of light momentum to microspheres under resonant conditions. The peak
magnitude of the resonant force is shown to approach total absorption limit
imposed by the conservation of momentum. The transverse movement of the spheres
during the propulsion process was studied and the existence of a stable radial
trap was demonstrated. Giant resonant propulsion forces can be used for
large-scale sorting of microspheres with ultrahigh uniform resonant properties.",1509.01306v1
2015-09-28,Transit timing variations for planets near eccentricity-type mean motion resonances,"We derive the transit timing variations (TTVs) of two planets near a second
order mean motion resonance on nearly circular orbits. We show that the TTVs of
each planet are given by sinusoids with a frequency of $j n_2-(j-2)n_1$, where
$j \ge 3$ is an integer characterizing the resonance and $n_2$ and $n_1$ are
the mean motions of the outer and inner planets, respectively. The amplitude of
the TTV depends on the mass of the perturbing planet, relative to the mass of
the star, and on both the eccentricities and longitudes of pericenter of each
planet. The TTVs of the two planets are approximated anti-correlated, with
phases of $\phi$ and $\approx \phi+\pi$, where the phase $\phi$ also depends on
the eccentricities and longitudes of pericenter. Therefore, the TTVs caused by
proximity to a second order mean motion resonance do not in general uniquely
determine both planet masses, eccentricities, and pericenters. This is
completely analogous to the case of TTVs induced by two planets near a first
order mean motion resonance. We explore how other TTV signals, such as the
short-period synodic TTV or a first order resonant TTV, in combination with the
second order resonant TTV, can break degeneracies. Lastly, we derive
approximate formulae for the TTVs of planets near any order eccentricity-type
mean motion resonance; this shows that the same basic sinusoidal TTV structure
holds for all eccentricity-type resonances. Our general formula reduces to
previously derived results near first order mean motion resonances.",1509.08460v2
2015-10-19,On the Erigone family and the $z_2$ secular resonance,"The Erigone family is a C-type group in the inner main belt. Its age has been
estimated by several researchers to be less then 300 My, so it is a relatively
young cluster. Yarko-YORP Monte Carlo methods to study the chronology of the
Erigone family confirm results obtained by other groups. The Erigone family,
however, is also characterized by its interaction with the $z_2$ secular
resonance. While less than 15% of its members are currently in librating states
of this resonance, the number of objects, members of the dynamical group, in
resonant states is high enough to allow to use the study of dynamics inside the
$z_2$ resonance to set constraints on the family age.
  Like the ${\nu}_{6}$ and $z_1$ secular resonances, the $z_2$ resonance is
characterized by one stable equilibrium point at $\sigma = 180^{\circ}$ in the
$z_2$ resonance plane $(\sigma, \frac{d\sigma}{dt})$, where $\sigma$ is the
resonant angle of the $z_2$ resonance. Diffusion in this plane occurs on
timescales of $\simeq 12$ My, which sets a lower limit on the Erigone family
age. Finally, the minimum time needed to reach a steady-state population of
$z_2$ librators is about 90 My, which allows to impose another, independent
constraint on the group age.",1510.05551v1
2015-10-27,The influence of the Coulomb exchange term on nuclear single-proton resonances,"Nuclear single-proton resonances are sensitive to the Coulomb field, while
the exchange term of Coulomb field is usually neglected due to its nonlocality.
By combining the complex scaling method with the relativistic mean-field model,
the influence of the Coulomb exchange term on the single-proton resonances is
investigated by taking Sn isotopes and $N=82$ isotones as examples. It is found
that the Coulomb exchange term reduces the single-proton resonance energy
within the range of $0.4-0.6$ MeV, and lead to similar isotopic and isotonic
trends of the resonance energy as those without the Coulomb exchange term.
Moreover, the single-proton resonance width is also reduced by the Coulomb
exchange term, whose influence generally decreases with the increasing neutron
number and increases with the increasing proton number. However, the influence
of the Coulomb exchange term cannot change the trend of the resonance width
with respect to the neutron number and proton number. Furthermore, the
influence of the Coulomb exchange term on the resonance width is investigated
for the doubly magic nuclei $^{40}$Ca, $^{56,78}$Ni, $^{100,132}$Sn, and
$^{208}$Pb. It is found that the Coulomb exchange term reduces the proton
resonance width within $0.2$ MeV, whose magnitude depends on the specific
nucleus and the quantum numbers of resonant states.",1510.07857v1
2015-10-31,Nonlinear microwave photon-occupancy of a driven resonator strongly coupled to a transmon qubit,"We measure photon-occupancy in a thin-film superconducting lumped element
resonator coupled to a transmon qubit at 20$\,$mK and find a nonlinear
dependence on the applied microwave power. The transmon-resonator system was
operated in the strong dispersive regime, where the ac Stark shift ($2\chi$)
due to a single microwave photon present in the resonator was larger than the
linewidth ($\Gamma$) of the qubit transition. When the resonator was coherently
driven at $5.474325\,$GHz, the transition spectrum of the transmon at
$4.982\,$GHz revealed well-resolved peaks, each corresponding to an individual
photon number-state of the resonator. From the relative peak-heights we obtain
the occupancy of the photon-states and the average photon-occupancy $\bar{n}$
of the resonator. We observed a nonlinear variation of $\bar{n}$ with the
applied drive power $P_{rf}$ for $\bar{n} < 5$ and compare our results to
numerical simulations of the system-bath master equation in the steady state,
as well as to a semi-classical model for the resonator that includes the
Jaynes-Cummings interaction between the transmon and the resonator. We find
good quantitative agreement using both models and analysis reveals that the
nonlinear behavior is principally due to shifts in the resonant frequency
caused by a qubit-induced Jaynes-Cummings nonlinearity.",1511.00174v1
2015-11-04,"Compositeness of baryonic resonances: Applications to the Delta(1232), N(1535), and N(1650) resonances","We present a formulation of the compositeness for baryonic resonances in
order to discuss the meson-baryon molecular structure inside the resonances.
For this purpose, we derive a relation between the residue of the scattering
amplitude at the resonance pole position and the two-body wave function of the
resonance in a sophisticated way, and we define the compositeness as the norm
of the two-body wave functions. As applications, we investigate the
compositeness of the $\Delta (1232)$, $N (1535)$, and $N (1650)$ resonances
from precise $\pi N$ scattering amplitudes in a unitarized chiral framework
with the interaction up to the next-to-leading order in chiral perturbation
theory. The $\pi N$ compositeness for the $\Delta (1232)$ resonance is
evaluated in the $\pi N$ single-channel scattering, and we find that the $\pi
N$ component inside $\Delta (1232)$ in the present framework is nonnegligible,
which supports the previous work. On the other hand, the compositeness for the
$N (1535)$ and $N (1650)$ resonances is evaluated in a coupled-channels
approach, resulting that the $\pi N$, $\eta N$, $K \Lambda$ and $K \Sigma$
components are negligible for these resonances.",1511.01200v2
2016-01-30,Strongly-coupled nanotube electromechanical resonators,"Coupling an electromechanical resonator with carbon-nanotube quantum dots is
a significant method to control both the electronic charge and the spin quantum
states. By exploiting a novel micro-transfer technique, we fabricate two
strongly-coupled and electrically-tunable mechanical resonators on a single
carbon nanotube for the first time. The frequency of the two resonators can be
individually tuned by the bottom gates, and strong coupling is observed between
the electron charge and phonon modes of each resonator. Furthermore, the
conductance of either resonator can be nonlocally modulated by the phonon modes
in the other resonator. Strong coupling is observed between the phonon modes of
the two resonators, which provides an effective long distance electron-electron
interaction. The generation of phonon-mediated-spin entanglement is also
theoretically analyzed for the two resonators. This strongly-coupled nanotube
electromechanical resonator array provides an experimental platform for future
studies of the coherent electron-phonon interaction, the phonon mediated
long-distance electron interaction, and entanglement state generation.",1602.00082v1
2016-04-24,Spectral flow and resonance index,"It has been shown recently that spectral flow admits a natural integer-valued
extension to essential spectrum. This extension admits four different
interpretations; two of them are singular spectral shift function and total
resonance index. In this work we study resonance index outside essential
spectrum.
  Among results of this paper are the following.
  1. Total resonance index satisfies Robbin-Salamon axioms for spectral flow.
  2. Direct proof of equality ""total resonance index = intersection number"".
  3. Direct proof of equality ""total resonance index = total Fredholm index"".
  4. (a) Criteria for a perturbation~$V$ to be tangent to the~resonance set at
a point~$H,$ where the resonance set is the infinite-dimensional variety of
self-adjoint perturbations of the initial self-adjoint operator~$H_0$ which
have~$\lambda$ as an eigenvalue. (b) Criteria for the order of tangency of a
perturbation~$V$ to the resonance set.
  5. Investigation of the root space of the compact operator
$(H_0+sV-\lambda)^{-1}V$ corresponding to an eigenvalue $(s-r_\lambda)^{-1},$
where $H_0+r_\lambda V$ is a point of the resonance set.
  This analysis gives a finer information about behaviour of discrete spectrum
compared to spectral flow.
  Finally, many results of this paper are non-trivial even in finite
dimensions, in which case they can be and were tested in numerical experiments.",1604.07006v2
2016-07-21,Broken symmetry dielectric resonators for high quality-factor Fano metasurfaces,"We present a new approach to dielectric metasurface design that relies on a
single resonator per unit cell and produces robust, high quality-factor Fano
resonances. Our approach utilizes symmetry breaking of highly symmetric
resonator geoemetries, such as cubes, to induce couplings between the otherwise
orthogonal resonator modes. In particular, we design perturbations that couple
""bright"" dipole modes to ""dark"" dipole modes whose radiative decay is
suppressed by local field effects in the array. Our approach is widely scalable
from the near-infrared to radio frequencies. We first unravel the Fano
resonance behavior through numerical simulations of a germanium resonator-based
metasurface that achieved a quality-factor of ~1300 at ~10.8 um. Then, we
present two experimental demonstrations operating in the near-infrared (~1 um):
a silicon-based implementation that achieved a quality-factor of ~350; and a
gallium arsenide-based structure that achieves a quality-factor of ~600 - the
highest near-infrared quality-factor experimentally demonstrated to date with
this kind of metasurfaces. Importantly, large electromagnetic field
enhancements appear within the resonators at the Fano resonant frequencies. We
envision that combining high-quality factor, high field enhancement resonances
with nonlinear and active/gain materials such as gallium arsenide will lead to
new classes of active optical devices.",1607.06469v1
2017-02-01,Resonance capture at arbitrary inclination: II. Effect of the radial drift rate,"The effect of radial drift rate on mean motion resonance capture is studied
for prograde, polar and retrograde orbits. We employ the numerical framework of
our earlier exploration of resonance capture at arbitrary inclination. Randomly
constructed samples of massless particles are set to migrate radially from
outside the orbit of a Jupiter-mass planet at different drift rates totalling
more than $1.6\times 10^6$ numerical simulations. Slower drift rates reduce
overall capture probability especially for prograde orbits and enhance capture
at specific initial inclinations of high order resonances such as the outer
1:5, 1:4, 1:3, 2:5, 3:7 and 5:7. Global capture is reduced with increasing
eccentricity at all inclinations as high order resonances capture more
particles that are subsequently lost by disruptive close encounters with the
planet. The relative efficiency of retrograde resonances at long-lived capture
with respect to prograde resonances is explained by the reduced effect of
planet encounters as such events occur with a shorter duration and a higher
relative velocity for retrograde motion. Capture in the coorbital 1:1 resonance
is marginally affected by the radial drift rate except for nearly coplanar
retrograde eccentric orbits whose capture likelihood is increased significantly
with slower drift rates. An unexpected finding is the presence of a dynamical
corridor for capture in high order inner prograde resonances with initial
inclinations in the range [50$^\circ$,80$^\circ$] especially at the inner 5:2
resonance whose capture likelihood peaks at 80% to 90% depending on initial
eccentricity.",1702.00236v1
2019-05-15,A tunable ferroelectric based unreleased RF resonator,"This paper introduces the first tunable ferroelectric capacitor (FeCAP) based
unreleased RF MEMS resonator, integrated seamlessly in Texas Instruments' 130nm
Ferroelectric RAM (FeRAM) technology. An array of FeCAPs in this complementary
metal-oxide-semiconductor (CMOS) technology's back-end-of-line (BEOL) process
were used to define the acoustic resonance cavity as well as the
electromechanical transducers. To achieve high quality factor (Q) of the
resonator, acoustic waveguiding for vertical confinement within the CMOS stack
is studied and optimized. Additional design considerations are discussed to
obtain lateral confinement and suppression of spurious modes. An FeCAP
resonator is demonstrated with fundamental resonance at 703 MHz and Q of 1012.
This gives a frequency quality factor product fQ = 7.11$\times$10$^1$$^1$ which
is 1.6$\times$ higher than the most state-of-the-art Pb(Zr,Ti)O$_3$ (PZT)
resonators. Due to the ferroelectric characteristics of the FeCAPs,
transduction of the resonator can be switched on and off by adjusting the
electric polarization. In this case, the resonance can be turned off completely
at $\pm$0.3V corresponding to the coercive voltage of the constituent FeCAP
transducers. These novel switchable resonators may have promising applications
in on-chip timing, ad-hoc radio front ends, and chip-scale sensors.",1905.05903v1
2019-05-29,Resonant-State Expansion of the Fano Peak in Open Quantum Systems,"We describe the Fano asymmetry by expanding the transmission amplitude with
respect to states with point spectra (discrete eigenstates), including not only
bound states but also resonant states with complex eigenvalues. We first
introduce a novel complete set that spans the Hilbert space of the central part
of an open quantum-dot system. This complete set contains all states of point
spectra, but does not contain any states of continuous spectra. We thereby
analytically expand the conductance of the dot in terms of all discrete states
without any background integrals. This expansion implies that the resonant
states produce the main contributions to the electron transmission. We then
explain the Fano peak as an interference effect involving resonant states. We
find that there are three types of Fano asymmetry according to their origins:
the interference between a resonant state and an anti-resonant state, that
between a resonant state and a bound state, and that between two resonant
states. We derive microscopic expressions of the Fano parameters that describe
the three types of Fano asymmetry. We show that the last two types display the
asymmetric energy dependence given by Fano, but the first one shows a slightly
different form.",1905.12259v1
2020-07-04,Multiple Tunable Hyperbolic Resonances in Broadband Infrared Carbon-Nanotube Metamaterials,"Aligned, densely-packed carbon nanotube metamaterials prepared using vacuum
filtration are an emerging infrared nanophotonic material. We report multiple
hyperbolic plasmon resonances, together spanning the mid-infrared, in
individual resonators made from aligned and densely-packed carbon nanotubes. In
the first near-field scanning optical microscopy (NSOM) imaging study of
nanotube metamaterial resonators, we observe distinct deeply-subwavelength
field profiles at the fundamental and higher-order resonant frequencies. The
wafer-scale area of the nanotube metamaterials allows us to combine this
near-field imaging with a systematic far-field spectroscopic study of the
scaling properties of many resonator arrays. Thorough theoretical modeling
agrees with these measurements and identifies the resonances as higher-order
Fabry-P\'erot (FP) resonances of hyperbolic waveguide modes. Nanotube resonator
arrays show broadband extinction from 1.5-10 {\mu}m and reversibly switchable
extinction in the 3-5 {\mu}m atmospheric transparency window through the
coexistence of multiple modes in individual ribbons. Broadband carbon nanotube
metamaterials supporting multiple resonant modes are a promising candidate for
ultracompact absorbers, tunable thermal emitters, and broadband sensors in the
mid-infrared.",2007.01970v1
2018-05-21,Trans-Neptunian Objects Transiently Stuck in Neptune's Mean Motion Resonances: Numerical simulations of the current population,"A substantial fraction of our solar system's trans-Neptunian objects (TNOs)
are in mean motion resonance with Neptune. Many of these objects were likely
caught into resonances by planetary migration---either smooth or
stochastic---approximately 4 Gyr ago. Some, however, gravitationally scattered
off of Neptune and became transiently stuck in more recent events. Here, we use
numerical simulations to predict the number of transiently-stuck objects,
captured from the current actively scattering population, that occupy 111
resonances at semimajor axes $a=$30--100 au. Our source population is an
observationally constrained model of the currently-scattering TNOs. We predict
that, integrated across all resonances at these distances, the current
transient sticking population comprises 40\% of total
transiently-stuck+scattering TNOs, suggesting that these objects should be
treated as a single population. We compute the relative distribution of
transiently-stuck objects across all $p$:$q$ resonances with $1/6 \le q/p < 1$,
$p<40$, and $q<20$, providing predictions for the population of transient
objects with $H_r < 8.66$ in each resonance. We find that the relative
populations are approximately proportional to each resonance's libration period
and confirm that the importance of transient sticking increases with semimajor
axis in the studied range. We calculate the expected distribution of libration
amplitudes for stuck objects and demonstrate that observational constraints
indicate that both the total number and the amplitude-distribution of 5:2
resonant TNOs are inconsistent with a population dominated by transient
sticking from the current scattering disk. The 5:2 resonance hence poses a
challenge for leading theories of Kuiper belt sculpting.",1805.08228v1
2011-11-10,Resonances in sinh- and sine-Gordon models and higher equations of motion in Liouville theory,"The notion of operator resonances was introduced earlier by Al. Zamolodchikov
within the framework of the conformal perturbation theory. The resonances are
related to logarithmic divergences of integrals in the perturbation expansion,
and manifest themselves in poles of the correlation functions and form factors
of local operators considered as functions of conformal dimensions. The
residues of the poles can be computed by means of some operator identities.
Here we study the resonances in the Liouville, sinh- and sine-Gordon models,
considered as perturbations of a massless free boson. We show that the
well-known higher equations of motion discovered by Al. Zamolodchikov in the
Liouville field theory are nothing but resonance identities for some descendant
operators. The resonance expansion in the vicinity of a resonance point
provides a regularized version of the corresponding operators. We try to
construct the corresponding resonance identities and resonance expansions in
the sinh- and sine-Gordon theories. In some cases it can be done explicitly,
but in most cases we are only able to obtain a general form so far. We show
nevertheless that the resonances are perturbatively exact, which means that
each of them only appears in a single term of the perturbation theory.",1111.2547v5
2017-07-27,Electron spin resonance for the detection of long-range spin nematic order,"In this paper we propose that electron spin resonance (ESR) measurements
enable us to detect the long-range spin nematic order. We show that the
frequency of the paramagnetic resonance peak in the ESR spectrum is shifted by
the ferroquadrupolar order parameter together with other quantities. The
ferroquadrupolar order parameter is extractable from the angular dependence of
the frequency shift. In contrast, the antiferroquadrupolar order parameter is
usually invisible in the frequency shift. Instead, the long-range
antiferroquadrupolar order yields a characteristic resonance peak in the ESR
spectrum, which we call a magnon-pair resonance peak. This resonance
corresponds to the excitation of the bound magnon pair at the wave vector $\bm
k={\bm 0}$. Reflecting the condensation of bound magnon pairs, the field
dependence of the magnon-pair resonance frequency shows a singular upturn at
the saturation field. Moreover, the intensity of the magnon-pair resonance peak
shows a characteristic angular dependence and it vanishes when the magnetic
field is parallel to one of the axes that diagonalize the weak anisotropic
interactions. We confirm these general properties of the magnon-pair resonance
peak in the spin nematic phase by studying an $S=1$ bilinear-biquadratic model
on the square lattice in the linear flavor-wave approximation. In addition, we
argue applications to the $S=1/2$ frustrated ferromagnets and also the $S=1/2$
orthogonal dimer spin system SrCu$_2$(BO$_3$)$_2$, both of which are candidate
materials of spin nematics. Our theory for the antiferroquadrupolar ordered
phase is consistent with many features of the magnon-pair resonance peak
experimentally observed in the low-magnetization regime of
SrCu$_2$(BO$_3$)$_2$.",1707.08784v2
2017-12-12,Shifting of the resonance location for planets embedded in circumstellar disks,"Context: In the early evolution of a planetary system, a pair of planets may
be captured in a mean motion resonance while still embedded in their nesting
circumstellar disk. Aims: The goal is to estimate the direction and amount of
shift in the semimajor axis of the resonance location due to the disk gravity
as a function of the gas density and mass of the planets. The stability of the
resonance lock when the disk dissipates is also tested. Methods: The orbital
evolution of a large number of systems is numerically integrated within a
three-body problem in which the disk potential is computed as a series of
expansion. This is a good approximation, at least over a limited amount of
time. Results: Two different resonances are studied: the 2:1 and the 3:2. In
both cases the shift is inwards, even if by a different amount, when the
planets are massive and carve a gap in the disk. For super--Earths, the shift
is instead outwards. Different disk densities, Sigma, are considered and the
resonance shift depends almost linearly on Sigma. The gas dissipation leads to
destabilization of a significant number of resonant systems, in particular if
it is fast. Conclusions: The presence of a massive circumstellar disk may
significantly affect the resonant behavior of a pair of planets by shifting the
resonant location and by decreasing the size of the stability region. The disk
dissipation may explain some systems found close to a resonance but not locked
in it.",1712.04178v1
2020-01-21,Effects of neighbouring planets on the formation of resonant dust rings in the inner Solar System,"Context. Findings by the Helios and STEREO mission have indicated the
presence of a resonant circumsolar ring of dust associated with Venus. Attempts
to model this phenomenon as an analogue to the resonant ring of Earth - as a
result of migrating dust trapped in external mean-motion resonances (MMRs) -
have so far been unable to reproduce the observed dust feature. Other theories
of origin have recently been put forward. However, the reason for the low
trapping efficiency of Venus's external MMRs remains unclear. Aims. Here we
look into the nature of the dust trapping resonant phenomena that arise from
the multi-planet configuration of the inner Solar System, aiming to add to the
existent understanding of resonant dust rings in single planet systems.
Methods. We numerically modelled resonant dust features associated with the
inner planets and specifically looked into the dependency of these structures
and the trapping efficiency of particular resonances on the configuration of
planets. Results. Besides Mercury showing no resonant interaction with the
migrating dust cloud, we find Venus, Earth, and Mars to considerably interfere
with each other's resonances, influencing their ability to form circumsolar
rings. We find that the single most important reason for the weakness of
Venus's external MMR ring is the perturbing influence of its outer neighbour -
Earth. In addition, we find Mercury and Mars to produce crescent-shaped density
features, caused by a directed apsidal precession occurring in particles
traversing their orbital region.",2001.07611v1
2021-01-12,Excitation of resonant surface plasmons for evanescent waves refocusing by a superlens,"The amplification of evanescent waves by flat superlens requires a
near-resonance coupling which has been linked to resonant surface plasmons. A
subtle interplay has been proposed to exist between the excitation of
well-defined resonant surface plasmons and the focusing capability of a
superlens. To gain insights into these resonant modes and their contributions
to the amplification and recovery of evanescent waves, we performed simple but
robust full-wave FDTD simulations on causal negative index Lorentz models. We
found that well-defined pair of resonant surface plasmons is excited whenever a
coupling of a diverging transmitted beam and a converging refracted beam occurs
at the second interface. The resonant coupling of these modes at the interface
led to the excitation of a single interface resonance predicted by the theory.
The physical consequence of this resonance is that incident wave energy is
pumped into the negative-index material medium and beyond it. These phenomena
contribute substantially to the amplification and recovery of the near-fields
in the image plane. It is noteworthy that, for evanescent wave refocusing to be
achieved in a flat superlens, its thickness, and the source-to-superlens
distance should be optimized. This optimization is critical in that an optimal
thickness alongside optimal source-to-superlens distance will allow evanescent
wave refocusing to dominate material lost. The FDTD simulated result showed an
image of the point source inside the superlens and beyond it when its thickness
was optimized. The resolution of the image beyond the superlens was
$\sim.58\lambda$ and this superlens behaves like a near-perfect lens. Overall,
these numerically simulated results could serve as useful approximations to the
degree of resonant amplification and refocusing of near-fields that can be
achieved by flat superlens in near-fields experimental imaging setups.",2101.04625v1
2017-11-01,Efficient quantum microwave-to-optical conversion using electro-optic nanophotonic coupled-resonators,"We propose a low noise, triply-resonant, electro-optic (EO) scheme for
quantum microwave-to-optical conversion based on coupled nanophotonics
resonators integrated with a superconducting qubit. Our optical system features
a split resonance - a doublet - with a tunable frequency splitting that matches
the microwave resonance frequency of the superconducting qubit. This is in
contrast to conventional approaches where large optical resonators with
free-spectral range comparable to the qubit microwave frequency are used. In
our system, EO mixing between the optical pump coupled into the low frequency
doublet mode and a resonance microwave photon results in an up-converted
optical photon on resonance with high frequency doublet mode. Importantly, the
down-conversion process, which is the source of noise, is suppressed in our
scheme as the coupled-resonator system does not support modes at that
frequency. Our device has at least an order of magnitude smaller footprint than
the conventional devices, resulting in large overlap between optical and
microwave fields and large photon conversion rate ($g/2\pi$) in the range of
$\sim$5-15 kHz. Owing to large $g$ factor and doubly-resonant nature of our
device, microwave-to-optical frequency conversion can be achieved with optical
pump powers in the range of tens of microwatts, even with moderate values for
optical $\it{Q}$ ($\sim 10^6$) and microwave $Q$ ($ \sim10^4$). The performance
metrics of our device, with substantial improvement over the previous EO-based
approaches, promise a scalable quantum microwave-to-optical conversion and
networking of superconducting processors via optical fiber communication.",1711.00346v1
2019-01-01,Triply-resonant coupled-cavity electro-optic modulators for on-chip RF photonic systems,"We propose a triply-resonant electro-optic modulator architecture which
maximizes modulation efficiency using simultaneous resonant enhancement of the
RF drive signal, the optical pump, and the generated optical sideband. Optical
enhancement of the optical pump and the sideband is achieved using resonant
supermodes of two coupled optical resonators, and the RF enhancement is
achieved with LC circuits formed by the capacitances of the optical resonators
and inductors which can be implemented using CMOS technology. In the proposed
configuration, the photon lifetime determines the bandwidth of the RF response
but not its center frequency, which is set by the coupling strength between the
two resonators and is not subject to the photon lifetime constraint inherent to
conventional single-mode resonant modulators. This enables efficient operation
at high RF carrier frequencies without a reduction in efficiency commonly
associated with the photon lifetime limit. Two optical configurations of the
modulator are proposed: a ""basic"" configuration with equal Q-factors in both
supermodes, most suitable for narrowband RF signals, and a ""generalized""
configuration with independently tailored Q-factors of the two supermodes,
which makes it possible to broaden the RF bandwidth without sacrificing the
resonant enhancement of the optical pump and paying a penalty in modulation
efficiency associated with doing so. Additionally, a significant gain in
modulation efficiency is expected from RF signal enhancement by LC resonant
matching. This results in a modulator which is compact, efficient, and capable
of modulation at high RF carrier frequencies. The proposed modulator
architecture optimally engineers the interaction of the device with each of the
three signals and between them, can be applied to any modulator cavity design
or modulation mechanism and promises to enable complex RF-photonic systems on
chip.",1901.00071v1
2019-04-24,A mathematical theory for Fano resonance in a periodic array of narrow slits,"This work concerns resonant scattering by a perfectly conducting slab with
periodically arranged subwavelength slits, with two slits per period. There are
two classes of resonances, corresponding to poles of a scattering problem. A
sequence of resonances has an imaginary part that is nonzero and on the order
of the width $\varepsilon$ of the slits; these are associated with Fabry-Perot
resonance, with field enhancement of order $1/\varepsilon$ in the slits. The
focus of this study is another class of resonances which become real valued at
normal incidence, when the Bloch wavenumber $\kappa$ is zero. These are
embedded eigenvalues of the scattering operator restricted to a period cell,
and the associated eigenfunctions extend to surface waves of the slab that lie
within the radiation continuum. When $0<|\kappa|\ll 1$, the real embedded
eigenvalues will be perturbed as complex-valued resonances, which induce the
Fano resonance phenomenon. We derive the asymptotic expansions of embedded
eigenvalues and their perturbations as resonances when the Bloch wavenumber
becomes nonzero. Based on the quantitative analysis of the diffracted field, we
prove that the Fano-type anomalies occurs for the transmission of energy
through the slab, and show that the field enhancement is of order
$1/(\kappa\varepsilon)$, which is stronger than Fabry-Perot resonance.",1904.11019v3
2019-12-02,Locally resonant metasurfaces for shear waves in granular media,"In this article the physics of horizontally polarized shear waves travelling
across a locally resonant metasurface in an unconsolidated granular medium is
experimentally and numerically explored. The metasurface is comprised of an
arrangement of sub-wavelength horizontal mechanical resonators embedded in
silica microbeads. The metasurface supports a frequency-tailorable attenuation
zone induced by the translational mode of the resonators. The experimental and
numerical findings reveal that the metasurface not only backscatters part of
the energy, but also redirects the wavefront underneath the resonators leading
to a considerable amplitude attenuation at the surface level, when all the
resonators have similar resonant frequency. A more complex picture emerges when
using resonators arranged in a so-called graded design, e.g., with a resonant
frequency increasing/decreasing throughout the metasurface. Unlike Love waves
propagating in a bi-layer medium, shear waves localized at the surface of our
metasurface are not converted into bulk waves. Although a detachment from the
surface occurs, the depth-dependent velocity profile of the granular medium
prevents the mode-conversion, steering again the horizontally polarized shear
waves towards the surface. The outcomes of our experimental and numerical
studies allow for understanding the dynamics of wave propagation in resonant
metamaterials embedded in vertically inhomogeneous soils and, therefore, are
essential for improving the design of engineered devices for ground vibration
and seismic wave containment.",1912.00617v1
2019-12-24,A study of the high-inclination population in the Kuiper belt -- III. The 4:7 mean motion resonance,"The high-inclination population in the 4:7 mean motion resonance (MMR) with
Neptune has also substantial eccentricities ($e\gtrsim0.1$), with more inclined
objects tending to occupy more eccentric orbits. For this high-order resonance,
there are two different resonant modes. The principal one is the
eccentricity-type mode, and we find that libration is permissible for orbits
with $e\ge e_c^0$, where the critical eccentricity $e_c^0$ increases as a
function of increasing inclination $i$. Correspondingly, we introduce a
limiting curve $e_c^0(i)$, which puts constraints on the $(e, i)$ distribution
of possible 4:7 resonators. We then perform numerical simulations on the
sweep-up capture and long-term stability of the 4:7 MMR, and the results show
that the simulated resonators are well-constrained by this theoretical limiting
curve. The other 4:7 resonant mode is the mixed-$(e, i)$-type, and we show that
stable resonators should exist at $i\gtrsim20^{\circ}$. We predict that the
intrinsic number of these mixed-$(e, i)$-type resonators may provide a new clue
into the Solar system's evolution, but, so far, only one real object has been
observed resonating in this mode.",1912.11174v1
2020-06-30,Nonclassicality of open circuit QED systems in the deep-strong coupling regime,"We investigate theoretically how the ground state of a qubit-resonator system
in the deep-strong coupling (DSC) regime is affected by the coupling to an
environment. We employ as a variational ansatz for the ground state of the
qubit-resonator-environment system a superposition of coherent states displaced
in qubit-state-dependent directions. We show that the reduced density matrix of
the qubit-resonator system strongly depends on how the system is coupled to the
environment, i.e., capacitive or inductive, because of the broken rotational
symmetry of the eigenstates of the DSC system in the resonator phase space.
When the resonator couples to the qubit and the environment in different ways
(for instance, one is inductive and the other is capacitive), the system is
almost unaffected by the resonator-waveguide coupling. In contrast, when the
two couplings are of the same type (for instance, both are inductive), by
increasing the resonator-waveguide coupling strength, the average number of
virtual photons increases and the quantum superposition realized in the
qubit-resonator entangled ground state is partially degraded. Since the
superposition becomes more fragile with increasing the qubit-resonator
coupling, there exists an optimal coupling strength to maximize the
nonclassicality of the qubit-resonator system.",2006.16769v2
2020-08-07,Tidal Evolution of the Evection Resonance/Quasi-Resonance and the Angular Momentum of the Earth-Moon System,"Forming the Moon by a high-angular momentum impact may explain the Earth-Moon
isotopic similarities, however, the post-impact angular momentum needs to be
reduced by a factor of 2 or more to the current value (1 L_EM) after the Moon
forms. Capture into the evection resonance, occurring when the lunar perigee
precession period equals one year, could remove the angular momentum excess.
However the appropriate angular momentum removal appears sensitive to the tidal
model and chosen tidal parameters. In this work, we use a constant-time delay
tidal model to explore the Moon's orbital evolution through evection. We find
that exit from formal evection occurs early and that subsequently, the Moon
enters a quasi-resonance regime, in which evection still regulates the lunar
eccentricity even though the resonance angle is no longer librating. Although
not in resonance proper, during quasi-resonance angular momentum is
continuously removed from the Earth-Moon system and transferred to Earth's
heliocentric orbit. The final angular momentum, set by the timing of
quasi-resonance escape, is a function of the ratio of tidal strength in the
Moon and Earth and the absolute rate of tidal dissipation in the Earth. We
consider a physically-motivated model for tidal dissipation in the Earth as the
mantle cools from a molten to a partially molten state. We find that as the
mantle solidifies, increased terrestrial dissipation drives the Moon out of
quasi-resonance. For post-impact systems that contain >2 L_EM, final angular
momentum values after quasi-resonance escape remain significantly higher than
the current Earth-Moon value.",2008.02968v1
2021-04-01,Dynamical structures of retrograde resonances: analytical and numerical studies,"In this work, retrograde mean motion resonances (MMRs) are investigated by
means of analytical and numerical approaches. Initially, we define a new
resonant angle to describe the retrograde MMRs and then perform a series of
canonical transformations to formulate the resonant model, in which the phase
portrait, resonant centre and resonant width can be analytically determined. To
validate the analytical developments, the non-perturbative analysis is made by
taking advantage of Poincar\'e surfaces of section. Some modifications are
introduced in the production of Poincar\'e sections and, in particular, it
becomes possible to make direct comparisons between the analytical and
numerical results. It is found that there exists an excellent correspondence
between the phase portraits and the associated Poincar\'e sections, and the
analytical results agree well with the numerical results in terms of the
resonant width and the location of resonant centre. Finally, the numerical
approach is utilized to determine the resonant widths and resonant centres over
the full range of eccentricity. In particular, seven known examples of
retrograde asteroids including 2015 BZ509, 2008 SO218, 1999 LE31, 2000 DG8,
2014 AT28, 2016 LS and 2016 JK24 are found inside the libration zones of
retrograde MMRs with Jupiter. The results obtained in this work may be helpful
for understanding the dynamical evolution for asteroids inside retrograde MMRs.",2104.00497v1
2021-04-14,On the role of resonances in polluting white dwarfs by asteroids,"Pollution of white dwarf atmospheres may be caused by asteroids that
originate from the locations of secular and mean-motion resonances in planetary
systems. Asteroids in these locations experience increased eccentricity,
leading to tidal disruption by the white dwarf. We examine how the $\nu_6$
secular resonance shifts outwards into a previously stable region of the
asteroid belt, as the star evolves to a white dwarf. Analytic secular models
require a planet to be engulfed in order to shift the resonance. We show with
numerical simulations that as a planet gets engulfed by the evolving star, the
secular resonance shifts and the rate of tidal disruption events increases with
the engulfed planet's mass and its orbital separation. We also investigate the
behaviour of mean-motion resonances. The width of a mean-motion resonance
increases as the star loses mass and becomes a white dwarf. The $\nu_6$ secular
resonance is more efficient at driving tidal disruptions than mean-motion
resonances with Jupiter. By examining 230 observed exoplanetary systems whose
central star will evolve into a white dwarf, we find that along with an Earth
mass planet at $1\,\rm au$, hot Jupiters at a semi--major axis $a\gtrsim
0.05\,\rm au$ and super--Earths of mass $10\,\rm M_\oplus$ at $a\gtrsim
0.3\,\rm au$ represent planet types whose engulfment shifts resonances enough
to cause pollution of the white dwarfs to a degree in agreement with
observations.",2104.06692v1
2021-05-10,Efimov scenario for overlapping narrow Feshbach resonances,"While Efimov physics in ultracold atoms is usually modeled with an isolated
Feshbach resonance many real world resonances appear in close vicinity to each
other and are therefore overlapping. Here we derive a realistic model based on
the mutual coupling of an open channel and two closed molecular channels while
neglecting short-range physics as permitted by the narrow character of the
considered resonances. The model is applied to three distinct scenarios with
experimental relevance. We show that the effect of overlapping resonances is
manifested most strikingly at a narrow resonance in whose vicinity there is a
slightly narrower one. In this system the Efimov ground state extends not only
over the scattering length zero crossing between the two resonances but also
over the pole of the second resonance to finally meet the dissociation
threshold below it. In the opposite scenario, when a narrow resonance is
considered in the vicinity of a slightly broader one, we observe that the
Efimov features are pushed to lower binding energies and smaller scattering
lengths by a significant factor facilitating their experimental investigation.
Both scenarios are referenced to the case of two narrow resonances which are
far enough away from each other to be effectively decoupled. In this case the
two-channel model results are recovered. Finally, we analyze the rich
excitation spectrum of the system and construct and explain its nodal pattern.",2105.04394v1
2021-07-02,Isovector giant monopole and quadrupole resonances in a Skyrme energy density functional approach with axial symmetry,"[Background] Giant resonance (GR) is a typical collective mode of vibration.
The deformation splitting of the isovector (IV) giant dipole resonance is well
established. However, the splitting of GRs with other multipolarities is not
well understood. [Purpose] I explore the IV monopole and quadrupole excitations
and attempt to obtain the generic features of IV giant resonances in deformed
nuclei by investigating the neutral and charge-exchange channels
simultaneously. [Method] I employ a nuclear energy-density functional (EDF)
method: the Skyrme-Kohn-Sham-Bogoliubov and the quasiparticle random-phase
approximation are used to describe the ground state and the transition to
excited states. [Results] I find the concentration of the monopole strengths in
the energy region of the isobaric analog or Gamow-Teller resonance irrespective
of nuclear deformation, and the appearance of a high-energy giant resonance
composed of the particle-hole configurations of $2\hbar \omega_0$ excitation.
Splitting of the distribution of the strength occurs in the giant monopole and
quadrupole resonances due to deformation. The lower $K$ states of quadrupole
resonances appear lower in energy and possess the enhanced strengths in the
prolate configuration, and vice versa in the oblate configuration, while the
energy ordering depending on $K$ is not clear for the $J=1$ and $J=2$
spin-quadrupole resonances. [Conclusions] The deformation splitting occurs
generously in the giant monopole and quadrupole resonances. The $K$-dependence
of the quadrupole transition strengths is largely understood by the anisotropy
of density distribution.",2107.00867v1
2021-09-24,Anomalous Loss Reduction Below Two-Level System Saturation in Aluminum Superconducting Resonators,"Superconducting resonators are widely used in many applications such as qubit
readout for quantum computing, and kinetic inductance detectors. These
resonators are susceptible to numerous loss and noise mechanisms, especially
the dissipation due to two-level systems (TLS) which become the dominant source
of loss in the few-photon and low temperature regime. In this study,
capacitively-coupled aluminum half-wavelength coplanar waveguide resonators are
investigated. Surprisingly, the loss of the resonators was observed to decrease
with a lowering temperature at low excitation powers and temperatures below the
TLS saturation. This behavior is attributed to the reduction of the TLS
resonant response bandwidth with decreasing temperature and power to below the
detuning between the TLS and the resonant photon frequency in a discrete
ensemble of TLS. When response bandwidths of TLS are smaller than their
detunings from the resonance, the resonant response and thus the loss is
reduced. At higher excitation powers, the loss follows a logarithmic power
dependence, consistent with predictions from the generalized tunneling model
(GTM). A model combining the discrete TLS ensemble with the GTM is proposed and
matches the temperature and power dependence of the measured internal loss of
the resonator with reasonable parameters.",2109.11742v6
2022-03-22,Strategies for reducing frequency scatter in large arrays of superconducting resonators,"Superconducting resonators are now found in a broad range of applications
that require high-fidelity measurement of low-energy signals. A common feature
across almost all of these applications is the need for increased numbers of
resonators to further improve sensitivity, and the ability to read out large
numbers of resonators without the need for additional cryogenic complexity is a
primary motivation. One of the major limitations of current resonator arrays is
the observed scatter in the resonator frequencies when compared to the initial
design. Here we present recent progress toward identifying one of the dominant
underlying causes of resonator scatter, inductor line width fluctuation. We
designed and fabricated an array of lumped-element resonators with inductor
line width changing from 1.8um to 2.2um in step of 0.1um defined with
electron-beam lithography to probe and quantify the systematic variation of
resonance frequency across a 6-inch wafer. The resonators showed a linear
frequency shift of 20MHz (140FWHM) and 30MHz (214FWHM), respectively, as they
are connected to two different capacitors. This linear relationship matches our
theoretical prediction. The widely used MLA photon lithography facility for
MKID fabrication has a resolution on the order of 600nm, which could cause
frequency fluctuation on the order of 100MHz or 710FWHM.",2203.17244v1
2022-05-11,Mathematical theory for electromagnetic scattering resonances and field enhancement in a subwavelength annular gap,"This work presents a mathematical theory for electromagnetic scattering
resonances in a subwavelength annular hole embedded in a metallic slab, with
the annulus width $h\ll1$. The model is representative among many 3D
subwavelength hole structures, which are able to induce resonant scattering of
electromagnetic wave and the so-called extraordinary optical transmission. We
develop a multiscale framework for the underlying scattering problem based upon
a combination of the integral equation in the exterior domain and the waveguide
mode expansion inside the tiny hole. The matching of the electromagnetic field
over the hole aperture leads to a sequence of decoupled infinite systems, which
are used to set up the resonance conditions for the scattering problem. By
performing rigorous analysis for the infinite systems and the resonance
conditions, we characterize all the resonances in a bounded domain over the
complex plane. It is shown that the resonances are associated with the TE and
TEM waveguide modes in the annular hole, and they are close to the real axis
with the imaginary parts of order ${\cal O}(h)$. We also investigate the
resonant scattering when an incident wave is present. It is proved that the
electromagnetic field is amplified with order ${\cal O}(1/h)$ at the resonant
frequencies that are associated with the TE modes in the annular hole. On the
other hand, one particular resonance associated with the TEM mode can not be
excited by a plane wave but can be excited with a near-field electric dipole
source, leading to field enhancement of order ${\cal O}(1/h)$.",2205.05377v1
2022-05-24,Resolution Limits of Resonant Sensors with Duffing Non-Linearity,"The resolution of resonant sensors is fundamentally limited by the presence
of noise. Thermomechanical noise, intrinsic to the resonator, sets the ultimate
sensor performance when all other noise sources have been eliminated. For
linear resonators, the sensing resolution can always be further improved by
increasing the driving power. However, this trend cannot continue indefinitely,
since at sufficiently high driving powers non-linear effects emerge and
influence the noise performance. As a consequence, the resonator's non-linear
characteristics play an inextricable role in determining its ultimate
resolution limits. Recently, several works have studied the characteristic
performance of non-linear resonators as sensors, with the counter intuitive
conclusion that increasing the quality factor of a resonator does not improve
its sensing resolution at the thermomechanical limit. In this work we further
analyze the ultimate resolution limits, and describe different regimes of
performance at integration times below and above the resonator's decay time. We
provide an analytical model to elucidate the effects of Duffing non-linearity
on the resolution of closed-loop sensors, and validate it using numerical
simulations. In contrast to previous works, our model and simulations show that
under certain conditions the ultimate sensing resolution of a Duffing resonator
can be improved by maximizing its quality factor. With measurements on a
nanomechanical membrane resonator, we experimentally verify the model and
demonstrate that frequency resolutions can be achieved that surpass the
previously known limits.",2205.11903v1
2022-07-12,Quadrupole and octupole order resonances in non-restricted hierarchical planetary systems,"Nonrestricted hierarchical three-body configurations are common in various
scales of astrophysical systems. Dynamical structures of the quadrupole-order
resonance (the von Zeipel-Lidov-Kozai resonance) and the octupole-order
resonance (the apsidal resonance) under the nonrestricted hierarchical
planetary systems are investigated in this work by taking advantage of
perturbative treatments. Under the quadrupole-order Hamiltonian model, the
distribution of libration and circulation regions as well as the distribution
of flipping region are analytically explored in the parameter space spanned by
the conserved quantities. The fundamental frequencies of system are produced
and then the nominal location of octupole-order resonance is identified. From
the viewpoint of perturbative theory, the quadrupole-order Hamiltonian
determines the unperturbed dynamical model and the octupole-order Hamiltonian
plays an role of perturbation to the quadrupole-order dynamics. The resonant
Hamiltonian for octupole-order resonances is formulated by means of averaging
theory, giving rise to a new constant of motion. Phase portraits are produced
to analyse dynamical structures of octupole-order resonance, including resonant
centres, saddle points, dynamical separatrices and islands of libration. By
analysing phase portraits, it is found that there are four branches of
libration centre and eight libration zones in the considered space.
Applications to orbit flips show that there are five flipping regions.",2207.05362v1
2022-07-26,Resonant tides in binary neutron star mergers: analytical-numerical relativity study,"Resonant excitations of $f$-modes in binary neutron star coalescences
influence the gravitational waves (GWs) emission in both quasicircular and
highly eccentric mergers and can deliver information on the star interior. Most
models of resonant tides are built using approximate, perturbative approaches
and thus require to be carefully validated against numerical relativity (NR)
simulations in the high-frequency regime. We perform detailed comparisons
between a set of high-resolution NR simulations and the state of the art
effective one body (EOB) model ${\tt TEOBResumS}$ with various tidal potentials
and including a model for resonant tides. For circular mergers, we find that
$f$-mode resonances can improve the agreement between EOB and NR, but there is
no clear evidence that the tidal enhancement after contact is due to a resonant
mechanism. Tidal models with $f$-mode resonances do not consistently reproduce,
at the same time, the NR waveforms and the energetics within the errors, and
their performances is comparable to resummed tidal models without resonances.
For highly eccentric mergers, we show for the first time that our EOB model
reproduces the bursty NR waveform to a high degree of accuracy. However, the
considered resonant model does not capture the $f$-mode oscillations excited
during the encounters and present in the NR waveform. Finally, we analyze
GW170817 with both adiabatic and dynamical tides models and find that the data
shows no evidence in favor of models including dynamical tides. This is in
agreement with the fact that resonant tides are measured at very high
frequencies, which are not available for GW170817 but might be tested with next
generation detectors.",2207.13106v1
2022-09-02,Modeling frequency shifts of collective bubble resonances with the boundary element method,"Increasing the number of closely-packed air bubbles immersed in water changes
the frequency of the Minnaert resonance. The collective interactions between
bubbles in a small ensemble are primarily in the same phase, causing them to
radiate a spherically-symmetric field that peaks at a frequency lower than the
Minnaert resonance for a single bubble. In contrast, large periodic arrays
include bubbles that are further apart than half the wavelength, so that
collective resonances have bubbles oscillating in opposite phases, ultimately
creating a fundamental resonance at a frequency higher than the single-bubble
Minnaert resonance. This work investigates the transition in resonance behavior
using a modal analysis of a mass-spring system and a boundary element method.
We significantly reduce the computational complexity of the full-wave solver to
a linear dependence on the number of bubbles in a rectangular array. The
simulated acoustic fields confirm the initial downshift in resonance frequency
and the strong influence of collective resonances when the array has hundreds
of bubbles covering more than half the wavelength. These results are essential
in understanding the low-frequency resonance characteristics of bubble
ensembles, which have important applications in diverse fields such as
underwater acoustics, quantum physics, and metamaterial design.",2209.01245v2
2022-09-28,A novel Machine-Learning method for spin classification of neutron resonances,"The performance of nuclear reactors and other nuclear systems depends on a
precise understanding of the neutron interaction cross sections for materials
used in these systems. These cross sections exhibit resonant structure whose
shape is determined in part by the angular momentum quantum numbers of the
resonances. The correct assignment of the quantum numbers of neutron resonances
is, therefore, paramount. In this project, we apply machine learning to
automate the quantum number assignments using only the resonances' energies and
widths and not relying on detailed transmission or capture measurements. The
classifier used for quantum number assignment is trained using stochastically
generated resonance sequences whose distributions mimic those of real data. We
explore the use of several physics-motivated features for training our
classifier. These features amount to out-of-distribution tests of a given
resonance's widths and resonance-pair spacings. We pay special attention to
situations where either capture widths cannot be trusted for classification
purposes or where there is insufficient information to classify resonances by
the total spin $J$. We demonstrate the efficacy of our classification approach
using simulated and actual $^{52}$Cr resonance data.",2209.14403v2
2022-10-02,Dynamical history of the Galilean satellites for a fast migration of Callisto,"The dynamics of the innermost Galilean satellites (Io, Europa and Ganymede)
is characterised by a chain of mean motion resonances, called Laplace
resonance, and by a strong tidal dissipation that causes wide variations of
their semi-major axes over large timescales. The precise history of energy
dissipation in the Jovian system is not known, but several theories have been
proposed. Tidal resonance locking states that big outer moons can also migrate
fast. If this is the case for Callisto, then it should have crossed the 2:1
mean motion resonance with Ganymede in the past, affecting the motion of all
four Galilean satellites. Therefore, we aim to determine whether a fast
migration for Callisto is compatible with the current orbital configuration of
the system. Due to the chaotic nature of the resonant crossing, different
outcomes are possible. A small portion of our simulations shows that Callisto
can cross the 2:1 resonance with Ganymede without being captured and preserving
the Laplace resonance. However, in most cases, we found that Callisto is
captured into resonance, despite its divergent migration. As Callisto continues
to migrate fast outwards, the moons depart substantially from the exact 8:4:2:1
commensurability, while still maintaining the resonant chain. Callisto can
eventually escape it by crossing a high-order mean motion resonance with
Ganymede. Afterwards, the moons' system is able to relax to its current
configuration for suitable dissipation parameters of the satellites. Therefore
it is possible, although challenging, to build a self-consistent picture of the
past history of the Galilean satellites for a fast migration of Callisto.",2210.00424v1
2022-11-23,Q-factor mediated quasi-BIC resonances coupling in asymmetric dimer lattices,"Resonance coupling in the regime of bound states in the continuum (BICs)
provides an efficient method for engineering nanostructure's optical response
with various lineshape while maintaining an ultra-narrow linewidth feature,
where the quality factor of resonances plays a crucial role. Independent
manipulation of the Q factors of BIC resonances enables full control of
interaction behavior as well as both near- and far-field light engineering. In
this paper, we harness reflection symmetry (RS) and translational symmetry (TS)
protected BIC resonances supported in an asymmetric dimer lattice and
investigate Q-factor-mediated resonance coupling behavior under controlled TS
and RS perturbations. We focus on in-plane electrical dipole BIC (EDi-BIC) and
magnetic dipole BIC (MD-BIC) which are protected by RS, and out-of-plane
electrical dipole BIC (EDo-BIC) protected by TS. The coupling between EDi-BIC
and EDo-BIC exhibits a resonance crossing behavior where the transmission
spectrum at the crossing could be tuned flexibly, showing an
electromagnetically induced transparency lineshape or satisfying the lattice
Kerker condition with pure phase modulation capability depending on TS and RS
perturbed Q factors. While the coupling between MD-BIC and EDo-BIC shows an
avoided resonance crossing behavior, where the strongly coupled resonances
would lead to the formation of a Friedrich-Wintgen BICs whose spectral position
could also be shifted by tuning the Q factors. Our results suggest an
intriguing platform to explore BIC resonance interactions with independent Q
factor manipulation capability for realizing multi-functional meta-devices.",2211.12659v1
2023-02-06,"When, where, and how many planets end up in first-order resonances?","The theory of Type~I migration has been widely used in many studies.
Transiting multi-planet systems offer us the opportunity to examine the
consistency between observation and theory, especially for those systems
harbouring planets in Mean Motion Resonance (MMR). The displacement these
resonant pairs show from exact commensurability provides us with information on
their migration and eccentricity-damping histories. Here, we adopt a
probabilistic approach, characterized by two distributions -- appropriate for
either the resonant or non-resonant planets -- to fit the observed planet
period ratio distribution. With the Markov chain Monte Carlo (MCMC) method, we
find that ${\approx}15\%$ of exoplanets are in first order ($j+1{:}j$) MMRs,
the ratio of eccentricity-to-semi-major axis damping is too high to allow
overstable librations and that the results are by-and-large consistent with
Type-I migration theory. In addition, our modeling finds that a small fraction
of resonant pairs is captured into resonance during migration, implying late
planet formation (gas-poor). Most of the resonant pairs park themselves at the
migration barrier, indicating early planet formation (gas-rich). Furthermore,
after improving the criterion on two-body resonant trapping, we obtain an upper
limit of the disc surface density at the time the planets are locked in
resonance.",2302.03070v2
2023-02-11,Resonance-facilitated three-channel p-wave scattering,"Feshbach resonances of arbitrary width are typically described in terms of
two-channel models. Within these models, one usually considers a single dressed
resonance, with the option to extend the analysis by including resonant
open-channel features that can drastically change the observed threshold
effects. For the strong $^{40}\mathrm{K}$ p-wave resonance studied in Ref.
\cite{ahmed2021}, the interplay between an open-channel shape resonance and the
Feshbach resonance could explain the unexpected nonlinear variation of the
binding energy with magnetic field. However, the presented two-channel
treatment relies on the introduction of two independent fitting parameters,
whereas the typical Breit-Wigner expression would only account for one. This
results in an effective magnetic moment that acquires a nonphysical value,
which is an indication of a major shortcoming of the two-channel model
treatment. In this study, we observe how the presence of a closed-channel shape
resonance explains the physical mechanism behind the observations and
demonstrates the need of a three-channel treatment. We introduce our novel
model as \textit{resonance facilitated}, where all coupling is mediated by the
Feshbach state, while there is no direct coupling between the additional
channel and the open channel. Notably, the resonance-facilitated structure
greatly reduces the complexity of the full three-channel model. The typical
Breit-Wigner form of the two-channel Feshbach formalism is retained and the
full effect of the added channel can be captured by a single resonance dressing
factor, which describes how the free propagation in the Feshbach state is
dressed by the added channel.",2302.05642v1
2023-04-24,Resonance frequency tracking schemes for micro- and nanomechanical resonators,"Nanomechanical resonators can serve as high performance detectors and have
potential to be widely used in the industry for a variety of applications. Most
nanomechanical sensing applications rely on detecting changes of resonance
frequency. In commonly used frequency tracking schemes, the resonator is driven
at or close to its resonance frequency. Closed-loop systems can continually
check whether the resonator is at resonance and accordingly adjust the
frequency of the driving signal. In this work, we study three resonance
frequency tracking schemes, a feedback-free (FF), a self-sustaining oscillator
(SSO), and a phase-locked loop oscillator (PLLO) scheme. We improve and extend
the theoretical models for the FF and the SSO tracking schemes, and test the
models experimentally with a nanoelectromechanical system (NEMS) resonator. We
employ a SSO architecture with a pulsed positive feedback topology and compare
it to the commonly used PLLO and FF schemes. We show that all tracking schemes
are theoretically equivalent and that they all are subject to the same speed
versus accuracy trade-off characteristics. In order to verify the theoretical
models, we present experimental steady-state measurements for all tracking
schemes. Frequency stability is characterized by computing the Allan deviation.
We obtain almost perfect correspondence between the theoretical models and the
experimental measurements. These results show that the choice of the tracking
scheme is dictated by cost, robustness and usability in practice as opposed to
fundamental theoretical differences in performance.",2304.11889v2
2023-06-01,"Nonlinear characteristics of Ti, Nb, and NbN superconducting resonators for parametric amplifiers","Superconducting resonators and parametric amplifiers are important components
in scientific systems such as kinetic inductance detector arrays,
frequency-domain multiplexers for other superconducting bolometers,
spin-ensemble based memories, and circuit quantum electrodynamics
demonstrators. In this paper, we report microwave measurements of
superconducting Ti, Nb, and NbN resonators and their use as parametric
amplifiers. These half-wave resonators were fabricated under near identical
sputtering and lithographic conditions to ensure a like-for-like comparison of
material properties. We report a wide range of properties and behaviours in
terms of transition temperatures, resistivities, rate-limiting nonlinear
response times, nonlinear dissipation, signs of the nonlinear inductances and
their dependences on temperature and resonance harmonic. We have successfully
operated Nb and NbN resonators as high gain parametric amplifiers, achieving
greater than $20\,\mathrm{dB}$ of power amplification. We have shown that for a
half-wave resonator, amplification can be realised not only in the fundamental
resonance but also in the higher harmonic resonances. Further, for materials
with high transition temperatures, e.g. Nb and NbN, amplification can be
achieved at $\sim4\,\mathrm{K}$, i.e. a temperature maintained by a pulse tube
cooler. Finally, in materials systems that have very fast response times, e.g.
NbN, we have found that a cross-harmonic type of amplification can be achieved
by placing pump tone in a different resonant mode as the signal and the idler.
This wide range of observations will have important implications on the design
and application of superconducting parametric amplifiers.",2306.00685v2
2023-10-25,Pauli resonance states in light nuclei: how they appear and how they can be eliminated,"Systematic analysis of parameters and properties of the Pauli resonance
states are performed for light nuclei $^{6}$Li, $^{7}$Li, $^{8}$Be, $^{9}$Be
and $^{10}$B, which are treated as two-cluster systems. The Pauli resonance
states are redundant solutions of the resonating group method appearing when
one try use more advanced description of the internal structure of interacting
clusters. Our calculations are performed in a standard and advanced versions of
the resonating group method. The standard version employs wave functions of
many-particle shell model to describe internal motion of nucleons within each
cluster. The advanced version is based on three-cluster resonating group
method. As in the standard version, the internal wave functions of three
clusters are approximated by wave functions of many-particle shell model model.
However, in advanced version one of pair of clusters forms a bound state, and
third cluster is considered to interact with such state. It is found that the
Pauli resonance states in nuclei under consideration have energy between 11 and
46 MeV, and their widths vary from 8 keV to 6.7 MeV. Analysis of wave functions
of Pauli resonance states and matrix elements of norm kernel allowed us to
formulate an effective method for eliminating Pauli resonance states. It is
demonstrated that this method effectively eliminate all determined the Pauli
resonance states.",2310.16373v3
2023-11-09,"The Propulsion Performance of Dual Heaving Foils in Tandem, with Spanwise Flexibility","The impact of spanwise flexibility on the propulsion performance of two foils
arranged in tandem and subjected to a prescribed sinusoidal heaving motion has
been studied at a Reynolds number of 100. This comprises a wide range of
natural frequencies of the flexible foil, covering pre-resonance, resonance,
and post-resonance regimes, with respect to the heaving frequency. The
propulsion performance of the foils under different Strouhal numbers, with
either fixed reduced frequency or fixed natural frequency, has also been
investigated. We observed that the propulsion efficiency, thrust, and power
consumption drop, but the tip deformation coefficient increases to its maximum
when operating at resonance. The propulsion efficiency of the flexible dual
foils increases significantly in the pre-resonance regime at small Strouhal
numbers. Both thrust force and power consumption increase with the reduced
frequency during the pre- and post-resonance regimes. An instability phenomenon
is observed in the instantaneous tip deformation coefficient of the flexible
dual foils in the post-resonance regimes. We also find that the dual heaving
foils, with a larger resonance Strouhal number, achieve a greater thrust
increment compared with that of rigid dual heaving foils when working at the
pre-resonance regimes. Meanwhile, dual heaving foils with a smaller resonance
Strouhal number can achieve a larger propulsion efficiency increment compared
with that of rigid dual heaving foils when working at small Strouhal numbers.",2311.05255v1
2013-12-20,Stability Boundaries for Resonant Migrating Planet Pairs,"Convergent migration allows pairs of planet to become trapped into mean
motion resonances. Once in resonance, the planets' eccentricities grow to an
equilibrium value that depends on the ratio of migration time scale to the
eccentricity damping timescale, $K=\tau_a/\tau_e$, with higher values of
equilibrium eccentricity for lower values of $K$. For low equilibrium
eccentricities, $e_{eq}\propto K^{-1/2}$. The stability of a planet pair
depends on eccentricity so the system can become unstable before it reaches its
equilibrium eccentricity. Using a resonant overlap criterion that takes into
account the role of first and second order resonances and depends on
eccentricity, we find a function $K_{min}(\mu_p, j)$ that defines the lowest
value for $K$, as a function of the ratio of total planet mass to stellar mass
($\mu_p$) and the period ratio of the resonance defined as $P_1/P_2=j/(j+k)$,
that allows two convergently migrating planets to remain stable in resonance at
their equilibrium eccentricities. We scaled the functions $K_{min}$ for each
resonance of the same order into a single function $K_c$. The function $K_{c}$
for planet pairs in first order resonances is linear with increasing planet
mass and quadratic for pairs in second order resonances with a coefficient
depending on the relative migration rate and strongly on the planet to planet
mass ratio. The linear relation continues until the mass approaches a critical
mass defined by the 2/7 resonance overlap instability law and $K_c \to \infty$.
We compared our analytic boundary with an observed sample of resonant two
planet systems. All but one of the first order resonant planet pair systems
found by radial velocity measurements are well inside the stability region
estimated by this model. We calculated $K_c$ for Kepler systems without
well-constrained eccentricities and found only weak constraints on $K$.",1312.6099v1
2018-02-15,OSSOS IX: two objects in Neptune's 9:1 resonance -- implications for resonance sticking in the scattering population,"We discuss the detection in the Outer Solar System Origins Survey (OSSOS) of
two objects in Neptune's distant 9:1 mean motion resonance at semimajor axis
$a\approx~130$~au. Both objects are securely resonant on 10~Myr timescales,
with one securely in the 9:1 resonance's leading asymmetric libration island
and the other in either the symmetric or trailing asymmetric island. These
objects are the largest semimajor axis objects with secure resonant
classifications, and their detection in a carefully characterized survey allows
for the first robust resonance population estimate beyond 100~au. The detection
of these objects implies a 9:1 resonance population of $1.1\times10^4$ objects
with $H_r<8.66$ ($D~\gtrsim~100$~km) on similar orbits (95\% confidence range
of $\sim0.4-3\times10^4$). Integrations over 4~Gyr of an ensemble of clones
spanning these objects' orbit fit uncertainties reveal that they both have
median resonance occupation timescales of $\sim1$~Gyr. These timescales are
consistent with the hypothesis that these objects originate in the scattering
population but became transiently stuck to Neptune's 9:1 resonance within the
last $\sim1$~Gyr of solar system evolution. Based on simulations of a model of
the current scattering population, we estimate the expected resonance sticking
population in the 9:1 resonance to be 1000-4500 objects with $H_r<8.66$; this
is marginally consistent with the OSSOS 9:1 population estimate. We conclude
that resonance sticking is a plausible explanation for the observed 9:1
population, but we also discuss the possibility of a primordial 9:1 population,
which would have interesting implications for the Kuiper belt's dynamical
history.",1802.05805v2
2018-10-16,Exact discrete resonances in the Fermi-Pasta-Ulam-Tsingou system,"In systems of N coupled anharmonic oscillators, exact resonant interactions
play an important role in the energy exchange between normal modes. In the
weakly nonlinear regime, those interactions may facilitate energy equipartition
in Fourier space. We consider analytically resonant wave-wave interactions for
the celebrated Fermi-Pasta-Ulam-Tsingou (FPUT) system. Using a
number-theoretical approach based on cyclotomic polynomials, we show that the
problem of finding exact resonances for a system of N particles is equivalent
to a Diophantine equation whose solutions depend sensitively on the set of
divisors of N. We provide an algorithm to construct all possible resonances,
based on two methods: pairing-off and cyclotomic, which we introduce to build
up explicit solutions to the 4-, 5- and 6-wave resonant conditions. Our results
shed some light in the understanding of the long-standing FPUT paradox,
regarding the sensitivity of the resonant manifolds with respect to the number
of particles N and the corresponding time scale of the interactions leading to
thermalisation. In this light we demonstrate that 6-wave resonances always
exist for any N, while 5-wave resonances exist if N is divisible by 3 and N >
6. It is known (for finite N) that 4-wave resonances do not mix energy across
the spectrum, so we investigate whether 5-wave resonances can produce energy
mixing across a significant region of the Fourier spectrum by analysing the
interconnected network of Fourier modes that can interact nonlinearly via
resonances. The answer depends on the set of odd divisors of N that are not
divisible by 3: the size of this set determines the number of dynamically
independent components, corresponding to independent constants of motion
(energies). We show that 6-wave resonances connect all these independent
components, providing in principle a restoring mechanism for full-scale
thermalisation.",1810.06902v1
2020-09-02,Theory and numerical modeling of photonic resonances: Quasinormal Modal Expansion -- Applications in Electromagnetics,"The idea of the modal expansion in electromagnetics is derived from the
research on electromagnetic resonators, which play an essential role in
developments in nanophotonics. All of the electromagnetic resonators share a
common property: they possess a discrete set of special frequencies that show
up as peaks in scattering spectra and are called resonant modes. These resonant
modes are soon recognized to dictate the interaction between electromagnetic
resonators and light. This leads to a hypothesis that the optical response of
resonators is the synthesis of the excitation of each physical-resonance-state
in the system: Under the excitation of external pulses, these resonant modes
are initially loaded, then release their energy which contributes to the total
optical responses of the resonators. These resonant modes with complex
frequencies are known in the literature as the Quasi-Normal Mode (QNM).
Mathematically, these QNMs correspond to solutions of the eigenvalue problem of
source-free Maxwell's equations. In the case where the optical structure of
resonators is unbounded and the media are dispersive (and possibly anisotropic
and non-reciprocal) this requires solving non-linear (in frequency) and
non-Hermitian eigenvalue problems. Thus, the whole problem boils down to the
study of the spectral theory for electromagnetic Maxwell operators. As a
result, modal expansion formalisms have recently received a lot of attention in
photonics because of their capabilities to model the physical properties in the
natural resonance-state basis of the considered system, leading to a
transparent interpretation of the numerical results. This manuscript is
intended to extend the study of QNM expansion formalism, in particular, and
nonlinear spectral theory, in general. At the same time, several numerical
modelings are provided as examples for the application of modal expansion in
computations.",2009.01307v2
2023-06-08,A study of the high-inclination population in the Kuiper belt -- IV. High-order mean motion resonances in the classical region,"In our previous study of Neptune's 4:7 mean motion resonance (MMR), we
discovered that its resonant angle can only librate within a specific
eccentricity ($e$) versus inclination ($i$) region, determined by a theoretical
limiting curve curve (Li et al. 2020). This ``permissible region'' is
independent of time and encompasses the entire possible stable region. We now
generalize this theory to investigate all high-order MMRs embedded in the main
classical Kuiper belt (MCKB). We first consider the 2nd-order 3:5 MMR in the
framework of planet migration and resonance capture, and have further validated
our limiting curve theory for both captured and observed 3:5 resonators. It
suggests that only the $(e, i)$ pairs inside the individual permissible regions
should be chosen as initial conditions for studying the in-situ evolution of
high-order resonators. With such a new setting, we proceed to explore the
long-term stability (for 4 Gyr) of different resonant populations, and our
simulations predict that: (1) the 3:5 and 4:7 resonators are comparable in
number, and they could have inclinations up to $40^{\circ}$; (2) the
populations of objects in the higher order 5:9, 6:11, 7:12 and 7:13 resonances
is about 1/10 of the 3:5 (or 4:7) resonator population, and nearly all of them
are found on the less inclined orbits with $i<10^{\circ}$; (3) for these
high-order resonances, almost all resonators reside in their individual
permissible regions. In summary, our results make predictions for the number
and orbital distributions of potential resonant objects that will be discovered
in the future throughout the MCKB.",2306.05142v1
1995-09-27,The Phase Space Structure Near Neptune Resonances in the Kuiper Belt,"The Solar system beyond Neptune is believed to house a population of small
primordial bodies left over from the planet formation process. The region up to
heliocentric distance $\sim 50 AU$ (a.k.a. the Kuiper Belt) may be the source
of the observed short period comets. In this region, the phase space structure
near orbital resonances with Neptune is of special interest for the long term
stability of orbits. There is reason to believe that a significant fraction
(perhaps most) of the Kuiper Belt objects reside preferentially in these
resonance locations. This paper describes the dynamics of small objects near
the major orbital resonances with Neptune. Estimates of the widths of stable
resonance zones as well as the properties of resonant orbits are obtained from
the circular, planar restricted three-body model. Although this model does not
contain the full complexity of the long term orbital dynamics of Kuiper Belt
objects subject to the full N-body perturbations of all the planets, it does
provide a baseline for the phase space structure and properties of resonant
orbits in the trans-Neptunian Solar system.",9509141v1
1999-02-12,Aperiodicity-induced effects on the transmission resonances in multibarrier systems,"We study the resonant tunneling properties of an electron through a few types
of binary periodic and aperiodic multibarrier systems. Within the framework of
the effective-mass approximation, we calculate the transmission coefficients to
investigate the dependence of the transmission resonances on the system
parameters such as the kind of aperiodicity, the generation number, and the
widths of the wells and barriers. Similarities and differences of the
resonances between the binary periodic and aperiodic systems are discussed in
detail. Transmission resonances in aperiodic systems are found to be
characterized by complex resonance splitting and a variety of peak-to-valley
ratios which are not exhibited in the periodic system. For some energy ranges,
transmission resonances in aperiodic systems are also found to resemble those
in the periodic system, despite the existence of aperiodicity.",9902181v1
2000-08-09,Effect of resonances on the transport properties of two-dimensional disordered systems,"We study both analytically and numerically how the electronic structure and
the transport properties of a two-dimensional disordered system are modified in
the presence of resonances. The energy dependence of the density of states and
the localization length at different resonance energies and strengths of
coupling between resonances and random states are determined. The results show,
that at energy equals to the resonance energy there is an enhancement in the
density of states. In contrast, the localization length remains unaffected from
the presence of the resonances and is similar to the one of the standard
Anderson model. Finally, we calculate the diffusion constant as a function of
energy and we reveal interesting analogies with experimental results on light
scattering in the presence of Mie resonances.",0008149v1
2004-01-21,Current noise of a single-electron transistor coupled to a nano-mechanical resonator,"The current noise spectrum of a single-electron transistor (SET) coupled to a
nano-mechanical resonator is calculated in the classical regime. Correlations
between the charge on the SET island and the position of the resonator give
rise to a distinctive noise spectrum which can be very different from that of
the uncoupled SET. The current noise spectrum of the coupled system contains
peaks at both the frequency of the resonator and double the resonator
frequency, as well as a strong enhancement of the zero-frequency noise. The
heights of the peaks are controlled by the strength of the coupling between the
SET and the resonator, the damping of the resonator, and the temperature of the
system.",0401387v2
2005-01-29,Experimental Observation of Kondo-Fano Resonant Tunneling in Silicon-Doped GaAs/AlAs Multiple Quantum Wells,"We report experimental observation of Kondo-Fano resonant tunneling in
Si-doped GaAs/AlAs multiple quantum wells. The spectrum of differential
tunneling conductance at low bias shows a strong temperature dependent
resonance, whose peak is split in the presence of a magnetic field,
characteristic of a Kondo resonance. The data is well explained as a resonant
tunneling of conduction electrons at the Fermi level through the doped silicon
impurity states inside the wells by using an impurity Anderson model. The
Coulomb blockade resonance of the impurity states induces a Fano dip above the
Kondo resonance.",0501722v2
2006-01-16,Resonant tunneling and Fano resonance in quantum dots with electron-phonon interaction,"We theoretically study the resonant tunneling and Fano resonance in quantum
dots with electron-phonon (e-ph) interaction. We examine the bias-voltage ($V$)
dependence of the decoherence, using Keldysh Green function method and
perturbation with respect to the e-ph interaction. With optical phonons of
energy $\omega_0$, only the elastic process takes place when $eV<\omega_0$, in
which electrons emit and absorb phonons virtually. The process suppresses the
resonant amplitude. When $eV>\omega_0$, the inelastic process is possible which
is accompanied by real emission of phonons. It results in the dephasing and
broadens the resonant width. The bias-voltage dependence of the decoherence
cannot be obtained by the canonical transformation method to consider the e-ph
interaction if its effect on the tunnel coupling is neglected. With acoustic
phonons, the asymmetric shape of the Fano resonance grows like a symmetric one
as the bias voltage increases, in qualitative accordance with experimental
results.",0601327v2
2006-01-17,Orbital Response of Evanescent Cooper Pairs in Paramagnetically Limited Al Films,"We report a detailed study of the pairing resonance via tunneling density of
states in ultra-thin superconducting Al films in supercritical magnetic fields.
Particular emphasis is placed on effects of the perpendicular component of the
magnetic field on the resonance energy and magnitude. Though the resonance is
broadened and attenuated by $H_\bot$ as expected, its energy is shifted upward
linearly with $H_\bot$. Extension of the original theory of the resonance to
include strong perpendicular fields shows that at sufficiently large $H_\bot$
the overlap of the broadened resonance tail with the underlying degenerate
Fermi sea alters the spectral distribution of the resonance via the exclusion
principle. This leads to the shift of the the resonance feature to higher
energy.",0601375v1
2006-11-09,Spin susceptibility in bilayered cuprates: resonant magnetic excitations,"We study the momentum and frequency dependence of the dynamical spin
susceptibility in the superconducting state of bilayer cuprate superconductors.
We show that there exists a resonance mode in the odd as well as the even
channel of the spin susceptibility, with the even mode being located at higher
energies than the odd mode. We demonstrate that this energy splitting between
the two modes arises not only from a difference in the interaction, but also
from a difference in the free-fermion susceptibilities of the even and odd
channels. Moreover, we show that the even resonance mode disperses downwards at
deviations from ${\bf Q}=(\pi,\pi)$. In addition, we demonstrate that there
exists a second branch of the even resonance, similar to the recently observed
second branch (the $Q^*$-mode) of the odd resonance. Finally, we identify the
origin of the qualitatively different doping dependence of the even and odd
resonance. Our results suggest further experimental test that may finally
resolve the long-standing question regarding the origin of the resonance peak.",0611267v1
1997-11-20,Excitation of a Kaluza-Klein mode by parametric resonance,"In this paper we investigate a parametric resonance phenomenon of a
Kaluza-Klein mode in a $D$-dimensional generalized Kaluza-Klein theory. As the
origin of the parametric resonance we consider a small oscillation of a scale
of the compactification around a today's value of it. To make our arguments
definite and for simplicity we consider two classes of models of the
compactification: those by $S_{d}$ ($d=D-4$) and those by $S_{d_{1}}\times
S_{d_{2}}$ ($d_1\ge d_2$, $d_{1}+d_{2}=D-4$). For these models we show that
parametric resonance can occur for the Kaluza-Klein mode. After that, we give
formulas of a creation rate and a number of created quanta of the Kaluza-Klein
mode due to the parametric resonance, taking into account the first and the
second resonance band. By using the formulas we calculate those quantities for
each model of the compactification. Finally we give conditions for the
parametric resonance to be efficient and discuss cosmological implications.",9711058v2
2002-06-05,A mass formula for baryon resonances,"Light-baryon resonances with u,d, and s quarks only can be classified using
the non-relativistic quark model. When we assign to baryon resonances with
total angular momenta J intrinsic orbital angular momenta L and spin S we make
the following observations: plotting the squared masses of the light-baryon
resonances against these intrinsic orbital angular momenta L, Delta's with even
and odd parity can be described by the same Regge trajectory. For a given L,
nucleon resonances with spin S=3/2 are approximately degenerate in mass with
Delta resonances of same total orbital momentum L. To which total angular
momentum L and S couple has no significant impact on the baryon mass. Nucleons
with spin 1/2 are shifted in mass; the shift is - in units of squared masses -
proportional to the component in the wave function which is antisymmetric in
spin and flavor. Sequential resonances in the same partial wave are separated
in mass square by the same spacing as observed in orbital angular momentum
excitations. Based on these observations, a new baryon mass formula is proposed
which reproduces nearly all known baryon masses.",0206012v1
1998-02-10,Can Nearby Resonances Enhance D^0 - anti-D^0 Mixing?,"We consider the possibility that D^0 - anti-D^0 mixing undergoes resonant
enhancement. Various scenarios are explored, including the potential effects of
nearby pseudoscalar or scalar quark-antiquark (Q - anti-Q) resonances as well
as of hybrid quark-antiquark-gluon Q - anti-Q G states. Assuming reasonable
values for the resonance parameters we find relatively sizeable contributions
from individual resonances to both \Delta m_D and \Delta \Gamma_D. We derive a
variant of the GIM cancellation mechanism for the resonance amplitudes and show
that broken SU(3) can allow for sizeable residual effects. Additional input
from meson spectroscopy and lattice gauge simulations will be needed to improve
the accuracy of these predictions.",9802291v2
2002-07-12,The N* Program at Jefferson Lab - Status and Prospects,"I discuss recent results on the electroproduction and photoproduction of
mesons in the region of non-strange baryon resonances. Results on the
quadrupole transition from the ground state nucleon to the Delta(1232) show the
importance of pion cloud contributions to explain the observed quadrupole
transition multipoles. The excitation of the ""Roper"" resonance is being studied
in single pion production using unpolarized cross sections measurements and
beam spin asymmetries. New results on the S_{11}(1535) transition formfactor
give now a consistent picture over a large Q2 range. First results on
electroproduction of p pi^+ pi^- show intruiging resonance structure. which is
difficult to explain in an isobar model fit using known resonance properties,
and may hint at excitation of a ""missing"" resonance. Searches for resonances in
K^+Lambda also reveal resonance-like behavior. I briefly address a new avenue
of N* physics using exclusive deeply virtual Compton scattering, recently
measured for the first time at JLAB and at DESY.",0207149v2
2002-08-22,Rho Meson Properties in the Chiral Theory Framework,"We study the mass, width and couplings of the lightest resonance multiplet
with I(J^{PC})=1(1^{--}) quantum numbers. Effective field theories based on
chiral symmetry are employed in order to describe the form factor associated
with the two-pseudoscalar matrix element of the QCD vector current. The bare
poles of the intermediate resonances are regularized through a
Dyson-Schwinger-like summation. We explore the role of the resonance width in
physical observables and make a coupled-channel analysis of final-state
interactions. This provides many interesting properties, as the pole mass
M_rho{pole}= 764.1 +- 2.7 +4.0-2.5 MeV. At energies E~1 GeV, a second 1(1^{--})
resonance multiplet is considered in order to describe the data in a more
consistent way. From the phenomenologically extracted resonance couplings, we
obtain the chiral coupling L_9^r(mu0)= (7.04 +- 0.05 +0.19-0.27)* 10^{-3}, at
mu0=770$ MeV, and show how the running with the scale mu affects the resonance
parameters. A 1/N_C counting is adopted in this work and the consistency of the
large--N_C expansion is tested. Finally, we make an estimation of the
contribution from diagrams with resonances in crossed channels.",0208199v1
2006-02-02,The Instability of the Central Configuration Caused By Resonance Perturbation,"The gravitation interaction between particles is taken into account in
central configuration model. After that, the resonance perturbation of the
particle of the central configuration by distant satellite is considered in the
restricted 3-body problem approach. A shift between simple mean motion
resonances and parametric resonance zones is derived. This shift depends upon
mass satellite and central configuration properties. Unexpectedly, the
resonance structure depends only on particle density and number of particles in
the central configuration, but not depends on particles mass. Then, the system
of few non-interacted planar central configurations is considered. The
resonance structure, which follows from parametric instability, is more
abundant than for simple mean motion resonance case. The areas of parametric
instability restrict stable central configuration, placed in exact
commensurability, from both sides. The possible application to the planetary
ring structure is discussed.",0602042v2
2004-01-07,Phase shifts and resonances in the Dirac equation,"We review the analytic results for the phase shifts delta_{l}(k) in
non-relativistic scattering from a spherical well. The conditions for the
existence of resonances are established in terms of time-delays. Resonances are
shown to exist for p-waves (and higher angular momenta) but not for s-waves.
These resonances occur when the potential is not quite strong enough to support
a bound p-wave of zero energy. We then examine relativistic scattering by
spherical wells and barriers in the Dirac equation. In contrast to the
non-relativistic situation, s-waves are now seen to possess resonances in
scattering from both wells and barriers. When s-wave resonances occur for
scattering from a well, the potential is not quite strong enough to support a
zero momentum s-wave solution at E = m. Resonances resulting from scattering
from a barrier can be explained in terms of the `crossing' theorem linking
s-wave scattering from barriers to p-wave scattering from wells. A numerical
procedure to extract phase shifts for general short range potentials is
introduced and illustrated by considering relativistic scattering from a
Gaussian potential well and barrier.",0401015v1
2006-10-04,Tail resonances of FPU q-breathers and their impact on the pathway to equipartition,"Upon initial excitation of a few normal modes the energy distribution among
all modes of a nonlinear atomic chain (the Fermi-Pasta-Ulam model) exhibits
exponential localization on large time scales. At the same time resonant
anomalies (peaks) are observed in its weakly excited tail for long times
preceding equipartition. We observe a similar resonant tail structure also for
exact time-periodic Lyapunov orbits, coined q-breathers due to their
exponential localization in modal space. We give a simple explanation for this
structure in terms of superharmonic resonances. The resonance analysis agrees
very well with numerical results and has predictive power. We extend a
previously developed perturbation method, based essentially on a
Poincare-Lindstedt scheme, in order to account for these resonances, and in
order to treat more general model cases, including truncated Toda potentials.
Our results give qualitative and semiquantitative account for the superharmonic
resonances of q-breathers and natural packets.",0610006v1
1998-09-29,Identification of baryon resonances in central heavy-ion collisions at energies between 1 and 2 AGeV,"The mass distributions of baryon resonances populated in near-central
collisions of Au on Au and Ni on Ni are deduced by defolding the $p_t$ spectra
of charged pions by a method which does not depend on a specific resonance
shape. In addition the mass distributions of resonances are obtained from the
invariant masses of $(p, \pi^{\pm})$ pairs. With both methods the deduced mass
distributions are shifted by an average value of -60 MeV/c$^2$ relative to the
mass distribution of the free $\Delta(1232)$ resonance, the distributions
descent almost exponentially towards mass values of 2000 MeV/c^2. The observed
differences between $(p, \pi^-)$ and $(p, \pi^+)$ pairs indicate a contribution
of isospin $I = 1/2$ resonances. The attempt to consistently describe the
deduced mass distributions and the reconstructed kinetic energy spectra of the
resonances leads to new insights about the freeze out conditions, i.e. to
rather low temperatures and large expansion velocities.",9809005v1
2000-07-10,"Properties of Some Resonances of the 55Mn(p,g)56Fe Reaction in the Ep = 1.3 - 1.8 Mev Region","Radiative decay of 21 resonances in the 55Mn(p,g)56Fe reaction was studied in
the proton beam energy region Ep = 1.3 - 1.8 MeV. Branching of decay to many
low lying bound states up to excitation energy Ex ~ 8 MeV was measured. Exact
energy of all resonances has been established what pointed out that five of the
resonances are very close doublets. For all studied resonances were determined
their spin-parity charakteristics. Assignment of some resonances as isobaric
analogues of the states in the 56Mn nucleus was discused and short note about
energy systematics of isobaric analogue resonances was shown.",0007008v1
2005-03-18,What do we learn from Resonance Production in Heavy Ion Collisions?,"Resonances with their short life time and strong coupling to the dense and
hot medium are suggested as a signature of the early stage of the fireball
created in a heavy ion collision \cite{rap00,lut01,lut02}. The comparison of
resonances with different lifetimes and quark contents may give information
about time evolution and density and temperature of during the expanding of
fireball medium. Resonances in elementary reactions have been measured since
1960. Resonance production in elementary collisions compared with heavy ion
collisions where we expect to create a hot and dense medium may show the direct
of influence of the medium on the resonances. This paper shows a selection of
the recent resonance measurements from SPS and RHIC heavy ion colliders.",0503013v1
1996-06-07,Perturbation of Embedded Eigenvalue by a Near-Lying Resonance,"The case of quantum-mechanical system (including electronic molecules) is
considered where Hamiltonian allows a separation, in particular by the Faddeev
method, of a weakly coupled channel. Width (i.e. the imaginary part) of the
resonance generated by a discrete spectrum eigenvalue of the separated channel
is studied in the case where main part of the Hamiltonian gives itself another
resonance. It is shown that if real parts of these resonances coincide and, at
the same time, a coupling between the separated and main channels is
sufficiently small then the width of the resonance generated by the separated
(molecular) channel is inversely proportional to the width of the main
(nuclear) channel resonance. This phenomenon being a kind of universal law, may
play an important role increasing the ``cold fusion'' probability in electronic
molecules whose nuclear constituents have narrow pre-threshold resonances.",9606012v2
2001-04-28,Quark Model Study of The eta Photoproduction: Evidence for a New S11 Resonance?,"An extensive and systematic study of the recent eta photoproduction data up
to 1.2 GeV is presented within a chiral constituent quark model. A model
embodying all known nucleonic resonances shows clear need for a yet
undiscovered third S11 resonance in the second resonance region, for which we
determine the mass (1.729 GeV) and the total width (183 MeV). Furthermore, we
extract the configuration mixing angles, an important property of the
quark-quark interaction in the quark model, for the resonances S11(1535) and
S11(1650), as well as for the resonances D13(1520) and D13(1700). Our results
agree well with the quark model predictions. In addition, the partial eta N
decay widths and/or the photo-excitation helicity amplitudes for the nucleonic
resonances S11(1535), S11(1650), P11(1710), P13(1720), D13(1520), D13(1700),
D15(1675), and F15(1680) are also obtained in this approach.",0104084v1
1999-03-26,Resonance-Induced Effects in Photonic Crystals,"For the case of a simple face-centered-cubic photonic crystal of homogeneous
dielectric spheres, we examine to what extent single-sphere Mie resonance
frequencies are related to band gaps and whether the width of a gap can be
enlarged due to nearby resonances. Contrary to some suggestions, no spectacular
effects may be expected. When the dielectric constant of the spheres
$\epsilon_s$ is greater than the dielectric constant $\epsilon_b$ of the
background medium, then for any filling fraction $f$ there exists a critical
$\epsilon_c$ above which the lowest lying Mie resonance frequency falls inside
the lowest stop gap in the (111) crystal direction, close to its midgap
frequency. If $\epsilon_s <\epsilon_b$, the correspondence between Mie
resonances and both the (111) stop gap and a full gap does not follow such a
regular pattern. If the Mie resonance frequency is close to a gap edge, one can
observe a resonance-induced widening of a relative gap width by $\approx 5%$.",9903042v1
1999-07-23,Multiple resonance compensation for betatron coupling and its equivalence with matrix method,"Analyses of betatron coupling can be broadly divided into two categories: the
matrix approach that decouples the single-turn matrix to reveal the normal
modes and the hamiltonian approach that evaluates the coupling in terms of the
action of resonances in perturbation theory. The latter is often regarded as
being less exact but good for physical insight. The common opinion is that the
correction of the two closest sum and difference resonances to the working
point is sufficient to reduce the off-axis terms in the 4X4 single-turn matrix,
but this is only partially true. The reason for this is explained, and a method
is developed that sums to infinity all coupling resonances and, in this way,
obtains results equivalent to the matrix approach. The two approaches is
discussed with reference to the dynamic aperture. Finally, the extension of the
summation method to resonances of all orders is outlined and the relative
importance of a single resonance compared to all resonances of a given order is
analytically described as a function of the working point.",9907040v1
2003-06-18,Island Resonances,"Resonances driven by the error field multipoles in the magnets often show
themselves as islands in phase plots of the particle motion. In order to be
able to measure the strength of the island resonance, and then to correct it,
it is helpful to study how these resonances show themselves. In particular, one
can study how the presence of the island resonances distort the tune dependence
on the amplitude, and the emittance growth caused by the island resonance.
Islands in 4-dimensional phase space, unlike islands in 2-dimensional phase
space, are not easy to visualize. This study will show how to visualize the
islands in 4-dimensional phase space by studying the tune dependence on the
amplitude of the particle motion. These effects are to some extent measureable,
and can lead to a way to correct the resonance.",0306140v1
2005-02-11,"Experimental verification of a one-parameter scaling law for the quantum and ""classical"" resonances of the atom-optics kicked rotor","We present experimental measurements of the mean energy in the vicinity of
the first and second quantum resonances of the atom optics kicked rotor for a
number of different experimental parameters. Our data is rescaled and compared
with the one parameter epsilon--classical scaling function developed to
describe the quantum resonance peaks. Additionally, experimental data is
presented for the ``classical'' resonance which occurs in the limit as the
kicking period goes to zero. This resonance is found to be analogous to the
quantum resonances, and a similar one-parameter classical scaling function is
derived, and found to match our experimental results. The width of the quantum
and classical resonance peaks is compared, and their Sub-Fourier nature
examined.",0502061v1
2005-06-23,Gigantic transmission band edge resonance in periodic stacks of anisotropic layers,"We consider Fabry-Perot cavity resonance in periodic stacks of anisotropic
layers with misaligned in-plane anisotropy at the frequency close to a photonic
band edge. We show that in-plane dielectric anisotropy can result in a dramatic
increase in field intensity and group delay associated with the transmission
resonance. The field enhancement appears to be proportional to forth degree of
the number N of layers in the stack. By contrast, in common periodic stacks of
isotropic layers, those effects are much weaker and proportional to N^2. Thus,
the anisotropy allows to drastically reduce the size of the resonance cavity
with similar performance. The key characteristic of the periodic arrays with
the gigantic transmission resonance is that the dispersion curve omega(k)at the
photonic band edge has the degenerate form Delta(omega) ~ Delta(k)^4, rather
than the regular form Delta(omega) ~ Delta(k)^2. This can be realized in
specially arranged stacks of misaligned anisotropic layers. The degenerate band
edge cavity resonance with similar outstanding properties can also be realized
in a waveguide environment, as well as in a linear array of coupled multimode
resonators, provided that certain symmetry conditions are in place.",0506174v1
2003-05-12,Fano resonances in the overlapping regime,"The line shape of resonances in the overlapping regime is studied by using
the eigenvalues and eigenfunctions of the effective Hamiltonian of an open
quantum system. A generalized expression $\tilde q_k(E)$ for the Fano parameter
of the resonance state $k$ is derived that contains the interaction of the
state $k$ with neighboured states $l\ne k$ via the continuum. It is energy
dependent since the coupling coefficients between the state $k$ and the
continuum show a resonance-like behaviour at the energies of the neighboured
states $l\ne k$. Under certain conditions, the energy dependent $\tilde q_k(E)$
are equivalent to the generalized complex energy independent Fano parameters
that are introduced by Kobayashi et al. in analyzing experimental data.
Long-lived states appear mostly isolated from one another in the cross section,
also when they are overlapped by short-lived resonance states. The $\tilde
q_k(E)$ of narrow resonances allow therefore to study the complicated interplay
between different time scales in the regime of overlapping resonance states by
controlling them as a function of an external parameter.",0305064v1
2006-04-15,Observation of high-order quantum resonances in the kicked rotor,"Quantum resonances in the kicked rotor are characterized by a dramatically
increased energy absorption rate, in stark contrast to the momentum
localization generally observed. These resonances occur when the scaled
Planck's constant hbar=(r/s)*4pi, for any integers r and s. However only the
hbar=r*2pi resonances are easily observable. We have observed high-order
quantum resonances (s>2) utilizing a sample of low temperature, non-condensed
atoms and a pulsed optical standing wave. Resonances are observed for
hbar=(r/16)*4pi r=2-6. Quantum numerical simulations suggest that our
observation of high-order resonances indicates a larger coherence length than
expected from an initially thermal atomic sample.",0604110v1
2007-04-23,Ground-state magneto-optical resonances in Cesium vapour confined in an extremely thin cell,"Experimental and theoretical studies are presented related to the
ground-state magneto-optical resonance prepared in Cesium vapour confined in an
Extremely Thin Cell (ETC, with thickness equal to the wavelength of the
irradiating light). It is shown that the utilization of the ETC allows one to
examine the formation of a magneto-optical resonance on the individual
hyperfine transitions, thus distinguishing processes resulting in dark (reduced
absorption) or bright (enhanced absorption) resonance formation. We report on
an experimental evidence of the bright magneto-optical resonance sign reversal
in Cs atoms confined in the ETC. A theoretical model is proposed based on the
optical Bloch equations that involves the elastic interaction processes of
atoms in the ETC with its walls resulting in depolarization of the Cs excited
state which is polarized by the exciting radiation. This depolarization leads
to the sign reversal of the bright resonance. Using the proposed model, the
magneto-optical resonance amplitude and width as a function of laser power are
calculated and compared with the experimental ones. The numerical results are
in good agreement with the experiment.",0704.3010v1
2007-08-22,Shape resonances in modified effective range theory for electron-molecule collisions,"We develop a simple model of shape resonances in electron-molecule collisions
that is based on the modified effective-range expansion and analytical
solutions of the Schrodinger equation for the long-range part of the
interaction potential. We apply our model to electron scattering on N$_2$ and
CO$_2$. The parameters of the effective-range expansion (i.e. the scattering
length and the effective range) are determined from experimental, integral
elastic cross sections in the 0.1 - 1.0 eV energy range. For both molecular
targets our treatment predicts shape resonances that appear slightly higher
than experimentally known resonances in total cross sections. Agreement with
the experiment can be improved by assuming the position of the resonance in a
given partial wave. Influence of quadrupole potential on resonances is also
discussed: it can be disregarded for N$_2$ but gets significant for CO$_2$. In
conclusion, our model developed within the effective range formalism reproduces
well both the very low-energy behavior of the integral cross section as well as
the presence of resonances in the few eV range.",0708.2991v2
2007-10-01,A model for chaotic dielectric microresonators,"We develop a random-matrix model of two-dimensional dielectric resonators
which combines internal wave chaos with the deterministic Fresnel laws for
reflection and refraction at the interfaces. The model is used to investigate
the statistics of the laser threshold and line width (lifetime and Petermann
factor of the resonances) when the resonator is filled with an active medium.
The laser threshold decreases for increasing refractive index $n$ and is
smaller for TM polarization than for TE polarization, but is almost independent
of the number of out-coupling modes $N$. The Petermann factor in the line width
of the longest-living resonance also decreases for increasing $n$ and scales as
$\sqrt{N}$, but is less sensitive to polarization. For resonances of
intermediate lifetime, the Petermann factor scales linearly with $N$. These
qualitative parametric dependencies are consistent with the random-matrix
theory of resonators with small openings. However, for a small refractive index
where the resonators are very open, the details of the statistics become
non-universal. This is demonstrated by comparison with a particular dynamical
model.",0710.0227v1
2007-10-13,High quality factor gigahertz frequencies in nanomechanical diamond resonators,"We report actuation and detection of gigahertz-range resonance frequencies in
nano-crystalline diamond mechanical resonators. High order transverse vibration
modes are measured in coupled-beam resonators exhibiting frequencies up to
1.441 GHz. The cantilever-array design of the resonators translates the
gigahertz-range resonant motion of micron-long cantilever elements to the
displacement of the central supporting structure. Use of nano-crystalline
diamond further increases the frequency compared to single crystal silicon by a
factor of three. High clamping losses usually associated with micron-sized
straight beams are suppressed in the periodic geometry of our resonators,
allowing for high quality factors exceeding 20,000 above 500 MHz.",0710.2613v1
2007-10-25,Optical detection of single electron spin resonance in a quantum dot,"We demonstrate optically detected spin resonance of a single electron
confined to a self-assembled quantum dot. The dot is rendered dark by resonant
optical pumping of the spin with a coherent laser. Contrast is restored by
applying a radio frequency (rf) magnetic field at the spin resonance. The
scheme is sensitive even to rf fields of just a few micro-T. In one case, the
spin resonance behaves exactly as a driven 3-level quantum system (a
lambda-system) with weak damping. In another, the dot exhibits remarkably
strong (67% signal recovery) and narrow (0.34 MHz) spin resonances with
fluctuating resonant positions, evidence of unusual dynamic processes of
non-Markovian character.",0710.4901v1
2007-11-29,Corotation Resonance and Diskoseismology Modes of Black Hole Accretion Disks,"We demonstrate that the corotation resonance affects only some
non-axisymmetric g-mode oscillations of thin accretion disks, since it is
located within their capture zones. Using a more general (weaker radial WKB
approximation) formulation of the governing equations, such g-modes, treated as
perfect fluid perturbations, are shown to formally diverge at the position of
the corotation resonance. A small amount of viscosity adds a small imaginary
part to the eigenfrequency which has been shown to induce a secular instability
(mode growth) if it acts hydrodynamically. The g-mode corotation resonance
divergence disappears, but the mode magnitude can remain largest at the place
of the corotation resonance. For the known g-modes with moderate values of the
radial mode number and axial mode number (and any vertical mode number), the
corotation resonance lies well outside their trapping region (and inside the
innermost stable circular orbit), so the observationally relevant modes are
unaffected by the resonance. The axisymmetric g-mode has been seen by Reynolds
& Miller in a recent inviscid hydrodynamic accretion disk global numerical
simulation. We also point out that the g-mode eigenfrequencies are
approximately proportional to m for axial mode numbers |m|>0.",0711.4848v1
2008-02-07,Vibrational resonances in 1D Morse and FPU lattices,"In the present paper the resonances of vibrational modes in one-dimensional
random Morse lattice are found and analyzed. The resonance energy exchange is
observed at some values of elongation. Resonance $2 \omega_1 = \omega_2$ is
investigated in details. The interacting modes are inequivalent: the
higher-frequency mode is much more stable in the excited state, i.e. its
life-time is larger than the life-time of lower-frequency mode under the
resonance conditions. Simple model of two nonlinearly coupled harmonic
oscillators is also considered. It allows to get analytical description and to
investigate the kinetics and the energy exchange degree vs. such parameters as
the resonance detuning and specific energy. The very similar behavior is found
in the Morse and the two-oscillatory models, and an excellent agreement between
analytical and numerical results is obtained. Analogous resonance phenomena are
also found in the random Fermi-Pasta-Ulam lattice under contraction.",0802.1013v1
2008-04-14,Probing the quantum coherence of a nanomechanical resonator using a superconducting qubit: I. Echo scheme,"We propose a scheme in which the quantum coherence of a nanomechanical
resonator can be probed using a superconducting qubit. We consider a mechanical
resonator coupled capacitively to a Cooper-pair box and assume that the
superconducting qubit is tuned to the degeneracy point so that its coherence
time is maximised and the electro-mechanical coupling can be approximated by a
dispersive Hamiltonian. When the qubit is prepared in a superposition of states
this drives the mechanical resonator progressively into a superposition which
in turn leads to apparent decoherence of the qubit. Applying a suitable control
pulse to the qubit allows its population to be inverted resulting in a reversal
of the resonator dynamics. However, the resonator's interactions with its
environment mean that the dynamics is not completely reversible. We show that
this irreversibility is largely due to the decoherence of the mechanical
resonator and can be inferred from appropriate measurements on the qubit alone.
Using estimates for the parameters involved based on a specific realization of
the system we show that it should be possible to carry out this scheme with
existing device technology.",0804.2194v1
2008-04-18,Cross-Molecular Coupling in Combined Photoassociation and Feshbach Resonances,"We model combined photoassociation and Feshbach resonances in a Bose-Einstein
condensate. When the magnetic field is far-off resonance, cross coupling
between the two target molecules--enabled by the shared dissociation
continuum--leads to an anomalous dispersive shift in the position of laser
resonance, as well as unprecedented elimination and enhancement of resonant
photoassociation via quantum interference. For off-resonant lasers, a
dispersive shift and quantum interference appear similarly in resonant
three-body Feshbach losses, except that the Feshbach node is tunable with
intensity.",0804.3011v2
2008-08-10,Low frequency elastic wave propagation in 2D locally resonant phononic crystal with asymmetric resonator,"The resonance modes and the related effects to the transmission of elastic
waves in a two dimensional phononic crystal formed by periodic arrangements of
a two blocks unit cell in one direction are studied. The unit cell consists of
two asymmetric elliptic cylinders coated with silicon rubber and embedded in a
rigid matrix. The modes are obtained by the semi-analytic method in the least
square collocation scheme and confirmed by the finite element method
simulations. Two resonance modes, corresponding to the vibration of the
cylinder along the long and short axes, give rise to resonance reflections of
elastic waves. One mode in between the two modes, related to the opposite
vibration of the two cylinders in the unit cell in the direction along the
layer, results in the total transmission of elastic waves due to zero effective
mass density at the frequency. The resonance frequency of this new mode changes
continuously with the orientation angle of the elliptic resonator.",0808.1396v1
2008-09-25,Quantum resonances in an atom-optical delta-kicked harmonic oscillator,"Under certain conditions, the quantum delta-kicked harmonic oscillator
displays quantum resonances. We consider an atom-optical realization of the
delta-kicked harmonic oscillator, and present a theoretical discussion of the
quantum resonances that could be observed in such a system. Having outlined our
model of the physical system we derive the values at which quantum resonances
occur and relate these to potential experimental parameters. We discuss the
observable effects of the quantum resonances, using the results of numerical
simulations. We develop a physical explanation for the quantum resonances based
on symmetries shared between the classical phase space and the
quantum-mechanical time evolution operator. We explore the evolution of
coherent states in the system by reformulating the dynamics in terms of a
mapping over an infinite, two-dimensional set of coefficients, from which we
derive an analytic expression for the evolution of a coherent state at quantum
resonance.",0809.4373v2
2008-09-26,Top-antitop and Top-top Resonances in the Dilepton Channel at the CERN LHC,"We perform a model-independent study for top-antitop and top-top resonances
in the dilepton channel at the Large Hadtron Collider. In this channel, we can
solve the kinematic system to obtain the momenta of all particles including the
two neutrinos, and hence the resonance mass and spin. For discovering
top-antitop resonances, the dilepton channel is competitive to the semileptonic
channel because of the good resolution of lepton momentum measurement and small
standard model backgrounds. Moreover, the charges of the two leptons can be
identified, which makes the dilepton channel advantageous for discovering
top-top resonances and for distinguishing resonance spins. We discuss and
provide resolutions for difficulties associated with heavy resonances and
highly boosted top quarks.",0809.4487v2
2008-12-14,Low-Energy Constants from Resonance Chiral Theory,"I discuss the recent attempts to build an effective chiral Lagrangian
incorporating massive resonance states. A useful approximation scheme to
organize the resonance Lagrangian is provided by the large-Nc limit of QCD.
Integrating out the resonance fields, one recovers the usual chiral
perturbation theory Lagrangian with explicit values for the low-energy
constants, parameterized in terms of resonance masses and couplings. The
resonance chiral theory generates Green functions that interpolate between QCD
and chiral perturbation theory. Analyzing these Green functions, both for large
and small momenta, one gets QCD constraints on the resonance couplings and,
therefore, information on the low-energy constants governing the Goldstone
interactions.",0812.2631v1
2009-01-26,Fully quantum-mechanical analytic results for single-photon transport in a single-mode waveguide coupled to a whispering-gallery resonator interacting with a two-level atom,"We analyze the single-photon transport in a single-mode waveguide coupled to
a whispering-gallery-type resonator interacting with a two-level atom. The
single-photon transport properties such as the transmission and reflection
amplitudes, as well as the resonator and the atom responses, are solved exactly
via a real-space approach. The treatment includes the inter-mode backscattering
between the two degenerate whispering gallery modes of the resonator, and the
dissipations of the resonator and the atom. We also show that a generalized
critical coupling condition, that the single-photon transmission at the output
of the waveguide goes to zero on resonance for a matched system, holds for the
full coupled waveguide-ring resonator-atom system.",0901.3940v1
2009-03-14,Noise color and asymmetry in stochastic resonance with silicon nanomechanical resonators,"Stochastic resonance with white noise has been well established as a
potential signal amplification mechanism in nanomechanical two-state systems.
While white noise represents the archetypal stimulus for stochastic resonance,
typical operating environments for nanomechanical devices often contain
different classes of noise, particularly colored noise with a 1/f spectrum. As
a result, improved understanding of the effects of noise color will be helpful
in maximizing device performance. Here we report measurements of stochastic
resonance in a silicon nanomechanical resonator using 1/f noise and
Ornstein-Uhlenbeck noise types. Power spectral densities and residence time
distributions provide insight into asymmetry of the bistable amplitude states,
and the data sets suggest that 1/f^alpha noise spectra with increasing noise
color (i.e. alpha) may lead to increasing asymmetry in the system, reducing the
achievable amplification. Furthermore, we explore the effects of correlation
time tau on stochastic resonance with the use of exponentially correlated
noise. We find monotonic suppression of the spectral amplification as the
correlation time increases.",0903.2522v1
2009-03-14,Collisional cooling of ultra-cold atom ensembles using Feshbach resonances,"We propose a new type of cooling mechanism for ultra-cold fermionic atom
ensembles, which capitalizes on the energy dependence of inelastic collisions
in the presence of a Feshbach resonance. We first discuss the case of a single
magnetic resonance, and find that the final temperature and the cooling rate is
limited by the width of the resonance. A concrete example, based on a p-wave
resonance of $^{40}$K, is given. We then improve upon this setup by using both
a very sharp optical or radio-frequency induced resonance and a very broad
magnetic resonance and show that one can improve upon temperatures reached with
current technologies.",0903.2568v1
2009-06-14,Stabilizing Hadron Resonance Gas Models against Future Discoveries,"We examine the stability of hadron resonance gas models by extending them to
take care of undiscovered resonances through the Hagedorn formula. We find that
the influence of unknown resonances on thermodynamics is large but bounded.
Hadron resonance gases are internally consistent up to a temperature higher
than the cross over temperature in QCD; but by examining quark number
susceptibilities we find that their region of applicability seems to end even
below the QCD cross over. We model the decays of resonances and investigate the
ratios of particle yields in heavy-ion collisions. We find that observables
such as hydrodynamics and hadron yield ratios change little upon extending the
model. As a result, heavy-ion collisions at RHIC and LHC are insensitive to a
possible exponential rise in the hadronic density of states, thus increasing
the stability of the predictions of hadron resonance gas models.",0906.2523v2
2009-09-20,Multiple Resonators as a Multi-Channel Bus for Coupling Josephson Junction Qubits,"Josephson junction-based qubits have been shown to be promising components
for a future quantum computer. A network of these superconducting qubits will
require quantum information to be stored in and transferred among them.
Resonators made of superconducting metal strips are useful elements for this
purpose because they have long coherence times and can dispersively couple
qubits. We explore the use of multiple resonators with different resonant
frequencies to couple qubits. We find that an array of resonators with
different frequencies can be individually addressed to store and retrieve
information, while coupling qubits dispersively. We show that a control qubit
can be used to effectively isolate an active qubit from an array of resonators
so that it can function within the same frequency range used by the resonators.",0909.3657v1
2009-10-05,Modeling noise induced resonance in an excitable system: An alternative approach,"Recently, it is observed [Md. Nurujjaman et al, Phy. Rev. E \textbf{80},
015201 (R) (2009)] that in an excitable system, one can maintain noise induced
coherency in the coherence resonance by blocking the destructive effect of the
noise on the system at higher noise level. This phenomenon of constant
coherence resonance (CCR) cannot be explained by the existing way of simulation
of the model equations of an excitable system with added noise. In this paper,
we have proposed a general model which explains the noise induced resonance
phenomenon CCR as well as coherence resonance (CR) and stochastic resonance
(SR). The simulation has been carried out considering the basic mechanism of
noise induced resonance phenomena: noise only perturbs the system control
parameter to excite coherent oscillations, taking proper precautions so that
the destructive effect of noise does not affect the system. In this approach,
the CR has been obtained from the interference between the system output and
noise, and the SR has been obtained by adding noise and a subthreshold signal.
This also explains the observation of the frequency shift of coherent
oscillations in the CCR with noise level.",0910.0681v2
2009-11-04,On the Super-Earths locked in the 3:2 mean-motion resonance,"The first study of migration-induced resonances in a pair of Earth-like
planets has been performed by Papaloizou and Szuszkiewicz (2005). They
concluded that in the case of disparate masses embedded in a disc with the
surface density expected for a minimum mass solar nebula at 5.2 au, the most
likely resonances are ratios of large integers, such as 8:7. For equal masses,
planets tend to enter into the 2:1 or 3:2 resonance. In Papaloizou and
Szuszkiewicz (2005) the two low-mass planets have masses equal to 4 Earth
masses, chosen to mimic the very well known example of two pulsar planets which
are close to the 3:2 resonance. That study has stimulated quite a few
interesting questions. One of them is considered here, namely how the behaviour
of the plan- ets close to the mean-motion resonance depends on the actual
values of the masses of the planets. We have chosen a 3:2 commensurability and
investigated the outcome of an orbital migration in the vicinity of this
resonance in the case of a pair of equal mass super-Earths, whose mass is
either 5 or 8 Earth masses.",0911.0924v1
2009-11-06,Spherical-box approach for resonances in presence of Coulomb interaction,"The spherical-box approach is extended to calculate the resonance parameters
and the real part of the wave function for single particle resonances in a
potential containing the long-range Coulomb interaction. A model potential is
taken to demonstrate the ability and accuracy of this approach. The calculated
resonance parameters are compared with available results from other methods. It
is shown that in the presence of the Coulomb interaction, the spherical-box
approach works well for not so broad resonances. In particular, for very narrow
resonances, the present method gives resonance parameters in a very high
precision.",0911.1171v1
2009-11-24,"Bound, virtual and resonance $S$-matrix poles from the Schrödinger equation","A general method, which we call the potential $S$-matrix pole method, is
developed for obtaining the $S$-matrix pole parameters for bound, virtual and
resonant states based on numerical solutions of the Schr\""odinger equation.
This method is well-known for bound states. In this work we generalize it for
resonant and virtual states, although the corresponding solutions increase
exponentially when $r\to\infty$. Concrete calculations are performed for the
$1^+$ ground and the $0^+$ first excited states of $^{14}\rm{N}$, the resonance
$^{15}\rm{F}$ states ($1/2^+$, $5/2^+$), low-lying states of $^{11}\rm{Be}$ and
$^{11}\rm{N}$, and the subthreshold resonances in the proton-proton system. We
also demonstrate that in the case the broad resonances their energy and width
can be found from the fitting of the experimental phase shifts using the
analytical expression for the elastic scattering $S$-matrix. We compare the
$S$-matrix pole and the $R$-matrix for broad $s_{1/2}$ resonance in
${}^{15}{\rm F}$",0911.4655v1
2010-04-27,Energy dependence of barKN interactions and resonance pole of strange dibaryons,"We study the resonance energy of the strange dibaryons using two models with
the energy-independent and energy-dependent potentials for the s-wave barKN
interaction, both of which are derived by certain reductions from the leading
order term of the effective chiral Lagrangian. These potential models produce
rather different off-shell behaviors of the two-body barKN - piSigma amplitudes
in I=0 channel, i.e., the model with energy-independent (energy-dependent)
potential predicts one (two) resonance pole in the Lambda(1405) region, while
they describe the available data equally well. We find that the
energy-independent potential model predicts one resonance pole of the strange
dibaryons, whereas the energy-dependent potential model predicts two resonance
poles: one is the shallow quasi-bound state of the barKNN, and another is the
resonance of the piYN with large width. An investigation of the binding energy
of the strange dibaryons will make a significant contribution to clarify
resonance structure of s-wave barKN - piSigma around the Lambda(1405) region.",1004.4877v1
2010-06-21,Experimental test of a trace formula for two-dimensional dielectric resonators,"Resonance spectra of two-dimensional dielectric microwave resonators of
circular and square shapes have been measured. The deduced length spectra of
periodic orbits were analyzed and a trace formula for dielectric resonators
recently proposed by Bogomolny et al. [Phys. Rev. E 78, 056202 (2008)] was
tested. The observed deviations between the experimental length spectra and the
predictions of the trace formula are attributed to a large number of missing
resonances in the measured spectra. We show that by taking into account the
systematics of observed and missing resonances the experimental length spectra
are fully understood. In particular, a connection between the most long-lived
resonances and certain periodic orbits is established experimentally.",1006.4080v1
2010-06-28,Stochastic resonance with matched filtering,"Along with the development of interferometric gravitational wave detector, we
enter into an epoch of gravitational wave astronomy, which will open a brand
new window for astrophysics to observe our universe. Almost all of the data
analysis methods in gravitational wave detection are based on matched
filtering. Gravitational wave detection is a typical example of weak signal
detection, and this weak signal is buried in strong instrument noise. So it
seems attractable if we can take advantage of stochastic resonance. But
unfortunately, almost all of the stochastic resonance theory is based on
Fourier transformation and has no relation to matched filtering. In this paper
we try to relate stochastic resonance to matched filtering. Our results show
that stochastic resonance can indeed be combined with matched filtering for
both periodic and non-periodic input signal. This encouraging result will be
the first step to apply stochastic resonance to matched filtering in
gravitational wave detection. In addition, based on matched filtering, we
firstly proposed a novel measurement method for stochastic resonance which is
valid for both periodic and non-periodic driven signal.",1006.5363v1
2010-07-12,Resonant Absorption as Mode Conversion?,"Resonant absorption and mode conversion are both extensively studied
mechanisms for wave ""absorption"" in solar magnetohydrodynamics (MHD). But are
they really distinct? We re-examine a well-known simple resonant absorption
model in a cold MHD plasma that places the resonance inside an evanescent
region. The normal mode solutions display the standard singular resonant
features. However, these same normal modes may be used to construct a ray
bundle which very clearly undergoes mode conversion to an Alfv\'en wave with no
singularities. We therefore conclude that resonant absorption and mode
conversion are in fact the same thing, at least for this model problem. The
prime distinguishing characteristic that determines which of the two
descriptions is most natural in a given circumstance is whether the converted
wave can provide a net escape of energy from the conversion/absorption region
of physical space. If it cannot, it is forced to run away in wavenumber space
instead, thereby generating the arbitrarily small scales in situ that we
recognize as fundamental to resonant absorption and phase mixing. On the other
hand, if the converted wave takes net energy way, singularities do not develop,
though phase mixing may still develop with distance as the wave recedes.",1007.1808v1
2010-08-12,Rotational Doppler Effect in Magnetic Resonance,"We compute the shift in the frequency of the spin resonance in a solid that
rotates in the field of a circularly polarized electromagnetic wave. Electron
spin resonance, nuclear magnetic resonance, and ferromagnetic resonance are
considered. We show that contrary to the case of the rotating LC circuit, the
shift in the frequency of the spin resonance has strong dependence on the
symmetry of the receiver. The shift due to rotation occurs only when rotational
symmetry is broken by the anisotropy of the gyromagnetic tensor, by the shape
of the body, or by magnetocrystalline anisotropy. General expressions for the
resonance frequency and power absorption are derived and implications for
experiment are discussed.",1008.2142v1
2010-10-14,Relating localized nanoparticle resonances to an associated antenna problem,"We conceptually unify the description of resonances existing at metallic
nanoparticles and optical nanowire antennas. To this end the nanoantenna is
treated as a Fabry-Perot resonator with arbitrary semi-nanoparticles forming
the terminations. We show that the frequencies of the quasi-static dipolar
resonances of these nanoparticles coincide with the frequency where the phase
of the complex reflection coefficient of the fundamental propagating plasmon
polariton mode at the wire termination amounts to $\pi$. The lowest order
Fabry-Perot resonance of the optical wire antenna occurs therefore even for a
negligible wire length. This approach can be used either to easily calculate
resonance frequencies for arbitrarily shaped nanoparticles or for tuning the
resonance of nanoantennas by varying their termination.",1010.2972v1
2010-10-20,Quantum entanglement between a nonlinear nanomechanical resonator and a microwave field,"We consider a theoretical model for a nonlinear nanomechanical resonator
coupled to a superconducting microwave resonator. The nanomechanical resonator
is driven parametrically at twice its resonance frequency, while the
superconducting microwave resonator is driven with two tones that differ in
frequency by an amount equal to the parametric driving frequency. We show that
the semi-classical approximation of this system has an interesting fixed point
bifurcation structure. In the semi-classical dynamics a transition from stable
fixed points to limit cycles is observed as one moves from positive to negative
detuning. We show that signatures of this bifurcation structure are also
present in the full dissipative quantum system and further show that it leads
to mixed state entanglement between the nanomechanical resonator and the
microwave cavity in the dissipative quantum system that is a maximum close to
the semi-classical bifurcation. Quantum signatures of the semi-classical
limit-cycles are presented.",1010.4094v2
2010-10-29,Confinement-induced p-wave resonances from s-wave interactions,"We show that a purely s-wave interaction in three dimensions (3D) can induce
higher partial-wave resonances in mixed dimensions. We develop two-body
scattering theories in all three cases of 0D-3D, 1D-3D, and 2D-3D mixtures and
determine the positions of higher partial-wave resonances in terms of the 3D
s-wave scattering length assuming a harmonic confinement potential. We also
compute the low-energy scattering parameters in the p-wave channel (scattering
volume and effective momentum) that are necessary for the low-energy effective
theory of the p-wave resonance. We point out that some of the resonances
observed in the Florence group experiment [Phys. Rev. Lett. 104, 153202 (2010)]
can be interpreted as the p-wave resonances in the 2D-3D mixed dimensions. Our
study paves the way for a variety of physics, such as Anderson localization of
matter waves under p-wave resonant scatterers.",1011.0033v2
2010-12-17,Electrically detected magnetic resonance of neutral donors interacting with a two-dimensional electron gas,"We have measured the electrically detected magnetic resonance of
channel-implanted donors in silicon field-effect transistors in resonant X-
($9.7\:$GHz) and W-band ($94\:$GHz) microwave cavities, with corresponding
Zeeman fields of $0.35\:$T and $3.36\:$T, respectively. It is found that the
conduction electron resonance signal increases by two orders of magnitude from
X- to W-band, while the hyperfine-split donor resonance signals are enhanced by
over one order of magnitude. We rule out a bolometric origin of the resonance
signals, and find that direct spin-dependent scattering between the
two-dimensional electron gas and neutral donors is inconsistent with the
experimental observations. We propose a new polarization transfer model from
the donor to the conduction electrons as the main contributer to the spin
resonance signals observed.",1012.3811v1
2011-02-08,Influence of External Fields and Environment on the Dynamics of Phase Qubit-Resonator System,"We analyze the dynamics of a qubit-resonator system coupled with a thermal
bath and external electromagnetic fields. Using the evolution equations for the
set of Heisenberg operators, that describe the whole system, we derive an
expression for the resonator field, accounting for the resonator-drive,-bath,
and -qubit interaction. The renormalization of the resonator frequency, caused
by the qubit-resonator interaction, is accounted for. Using solutions for the
resonator field, we derive the equation describing qubit dynamics. The
influence of the qubit evolution during the measurement time on the fidelity of
a single-shot measurement is studied. The relation between the fidelity and
measurement time is shown explicitly. Also, an expression describing relaxation
of the superposition qubit state towards its stationary value is derived. The
possibility of controlling this state, by varying the amplitude and frequency
of drive, is shown.",1102.1684v1
2011-02-14,Resonant enhancement of ultracold photoassociation rate by electric field induced anisotropic interaction,"We study the effects of a static electric field on the photoassociation of a
heteronuclear atom-pair into a polar molecule. The interaction of permanent
dipole moment with a static electric field largely affects the ground state
continuum wave function of the atom-pair at short separations where
photoassociation transitions occur according to Franck-Condon principle.
Electric field induced anisotropic interaction between two heteronuclear ground
state atoms leads to scattering resonances at some specific electric fields.
Near such resonances the amplitude of scattering wave function at short
separation increases by several orders of magnitude. As a result,
photoaasociation rate is enhanced by several orders of magnitude near the
resonances. We discuss in detail electric field modified atom-atom scattering
properties and resonances. We calculate photoassociation rate that shows giant
enhancement due to electric field tunable anisotropic resonances. We present
selected results among which particularly important are the excitations of
higher rotational levels in ultracold photoassociation due to electric field
tunable resonances.",1102.2687v2
2011-03-31,Multi-resonant scatterers in Sonic Crystals: Locally Multi-resonant Acoustic Metamaterial,"An acoustic metamaterial made of a two-dimensional (2D) periodic array of
multi-resonant acoustic scatterers is analysed in this paper. The building
blocks consist of a combination of elastic beams of Low-Density Polyethylene
Foam (LDPF) with cavities of known volume. Sound inside the structure can
excite elastic resonances of the material as well as acoustic resonances in the
cavities producing several attenuation peaks in the low-frequency range. Due to
this behaviour at the subwavelength regime we can define this periodic array as
a Locally Multi-Resonant Acoustic Metamaterial (LMRAM) presenting strong
dispersive characteristics of the effective properties with subwavelength
multi-resonant structural units. The results shown in this paper could be use
to design effective Sonic Crystal Acoustic Barriers with wide tunable
attenuation bands in the low-frequency range.",1103.6283v1
2011-04-13,Evidence for the J^p=1/2^+ narrow state at 1650 MeV in the photoproduction of KLambda,"We have investigated the existence of the J^p=1/2^+ narrow resonance
predicted by the chiral soliton model by utilizing the kaon photoproduction
process gamma + p --> K^+ + Lambda. For this purpose we have constructed two
phenomenological models based on our previous effective Lagrangian model, which
are able to describe kaon photoproduction from threshold up to W = 1730 MeV. By
varying the mass (width) of an inserted P_{11} resonance from 1620 to 1730 MeV
(0.1 to 1 MeV and 1 to 10 MeV) a number of fits has been performed in order to
search for the resonance mass. Our result indicates that the most promising
candidate mass (width) of this resonance is 1650 MeV (5 MeV). Although our
calculation does not exclude the possibility of narrow resonances with masses
of 1680, 1700 and 1720 MeV, the mass of 1650 MeV is obtained for all
phenomenological models used in this investigation. Variations of the resonance
width and $K\Lambda$ branching ratio are found to have a mild effect on the
chi^2. The possibility that the obtained result originates from other resonance
states is also discussed.",1104.2389v1
2011-05-09,Finite Size Effect on Nanomechanical Mass Detection: Role of Surface Elasticity,"Nanomechanical resonators have recently been highlighted because of their
remarkable ability to perform the sensing and detection. Since the
nanomechanical resonators are characterized by large surface-to-volume ratio,
it is implied that the surface effect plays a substantial role on not only the
resonance but also the sensing performance of nanomechanical resonators. In
this work, we have studied the role of surface effect on the detection
sensitivity of a nanoresonator that undergoes either harmonic vibration or
nonlinear oscillation based on the continuum elastic model such as beam model.
It is shown that surface effect makes an impact on both harmonic resonance and
nonlinear oscillations, and that the sensing performance is dependent on the
surface effect. Moreover, we have also investigated the surface effect on the
mechanical tuning of resonance and sensing performance. It is interestingly
found that the mechanical tuning of resonance is independent of surface effect,
and that the mechanical tuning of sensing performance is determined by surface
effect. Our study sheds light on the importance of surface effect on the
sensing performance of nanoresonators.",1105.1790v1
2011-05-23,Alternative Route to Strong Interaction: Narrow Feshbach Resonance,"We show that a narrow resonance produces strong interaction effects far
beyond its width on the side of the resonance where the bound state has not
been formed. This is due to a resonance structure of its phase shift, which
shifts the phase of a large number of scattering states by $\pi$ before the
bound state emerges. As a result, the magnitude of the interaction energy when
approaching the resonance on the ""upper"" and ""lower"" branch from different side
of the resonance is highly asymmetric, unlike their counter part in wide
resonances. Measurements of these effects are experimentally feasible.",1105.4627v4
2011-06-19,Quantum phase transition of light in a 1-D photon-hopping-controllable resonator array,"We give a concrete experimental scheme for engineering the
insulator-superfluid transition of light in a one-dimensional (1-D) array of
coupled superconducting stripline resonators. In our proposed architecture, the
on-site interaction and the photon hopping rate can be tuned independently by
adjusting the transition frequencies of the charge qubits inside the resonators
and at the resonator junctions, respectively, which permits us to
systematically study the quantum phase transition of light in a complete
parameter space. By combining the techniques of photon-number-dependent qubit
transition and fast read-out of the qubit state using a separate low-Q
resonator mode, the statistical property of the excitations in each resonator
can be obtained with a high efficiency. An analysis of the various decoherence
sources and disorders shows that our scheme can serve as a guide to coming
experiments involving a small number of coupled resonators.",1106.3751v2
2011-07-14,Confinement induced resonances in anharmonic waveguides,"We develop the theory of anharmonic confinement-induced resonances (ACIR).
These are caused by anharmonic excitation of the transverse motion of the
center of mass (COM) of two bound atoms in a waveguide. As the transverse
confinement becomes anisotropic, we find that the COM resonant solutions split
for a quasi-1D system, in agreement with recent experiments. This is not found
in harmonic confinement theories. A new resonance appears for repulsive
couplings ($a_{3D}>0$) for a quasi-2D system, which is also not seen with
harmonic confinement. After inclusion of anharmonic energy corrections within
perturbation theory, we find that these ACIR resonances agree extremely well
with anomalous 1D and 2D confinement induced resonance positions observed in
recent experiments. Multiple even and odd order transverse ACIR resonances are
identified in experimental data, including up to N=4 transverse COM quantum
numbers.",1107.2725v3
2011-08-10,Kondo Resonance in PrTi2Al20: Photoemission spectroscopy and single-impurity Anderson model,"The Kondo resonance at the Fermi level is well-established for the electronic
structure of Ce (f1 electron) and Yb (f1 hole) based systems. In this work, we
report complementary experimental and theoretical studies on the Kondo
resonance in Pr-based f2 system, PrTi2Al20. Using Pr 3d-4f resonant
photoemission spectroscopy and single impurity Anderson model (SIAM)
calculations including the full multiplets of Pr ions, we show that an f2
system can also give rise to a Kondo resonance at the Fermi level. The Kondo
resonance peak is experimentally observed through a final-state-multiplet
dependent resonance and is reproduced with properly tuned hybridization
strength in SIAM calculations.",1108.2122v2
2011-10-03,Interactions between directly and parametrically driven vibration modes in a micromechanical resonator,"The interactions between parametrically and directly driven vibration modes
of a clamped-clamped beam resonator are studied. An integrated piezoelectric
transducer is used for direct and parametric excitation. First, the parametric
amplification and oscillation of a single mode are analyzed by the power and
phase dependence below and above the threshold for parametric oscillation.
Then, the motion of a parametrically driven mode is detected by the induced
change in resonance frequency in another mode of the same resonator. The
resonance frequency shift is the result of the nonlinear coupling between the
modes by the displacement-induced tension in the beam. These nonlinear modal
interactions result in the quadratic relation between the resonance frequency
of one mode and the amplitude of another mode. The amplitude of a
parametrically oscillating mode depends on the square root of the pump
frequency. Combining these dependencies yields a linear relation between the
resonance frequency of the directly driven mode and the frequency of the
parametrically oscillating mode.",1110.0370v1
2012-03-05,Non-resonant effects in the top-antitop resonance region,"The recent developments on the computation of non-resonant corrections to the
e+ e- -> W+ W- b bbar cross section in the top-antitop resonance region are
reviewed in this talk. Non-resonant production of the final state W+ W- b bbar
starts to contribute at NLO in the nonrelativistic power-counting v ~ alpha_s ~
sqrt(alpha_EW). The corrections induced by non-resonant effects reduce the
cross section in the top-antitop resonance peak region at a level which is
comparable to the expected experimental precision at the future linear
collider, and are thus relevant for a high-precision top mass and width
determination.",1203.0934v1
2012-06-07,Atom-dimer p-wave resonance for fermionic mixtures with different masses,"We show that, near a Feshbach resonance, a strong p-wave resonance is present
at low energy in atom-dimer scattering for $^6$Li-$^{40}$K fermionic mixtures.
This resonance is due to a virtual bound state, in the atom-dimer system, which
is present at this low energy. When the mass ratio between the two fermionic
elements is increased, this virtual bound state goes to a known real bound
state which appears when the mass ratio reaches 8.17. This resonance should
affect a number of physical properties. These include the equation of state of
unbalanced mixtures at very low temperature but also the equation of state of
balanced mixtures at moderate or high temperature. The frequency and the
damping of collective modes should also provide a convenient way to evidence
this resonance. Finally it should be possible to modify the effective mass of
one the fermionic species by making use of an optical lattice. This would allow
to study the strong dependence of the resonance as a function of the mass ratio
of the two fermionic elements.",1206.1569v1
2012-06-08,Search for high-mass resonances decaying into tau-lepton pairs in pp collisions at sqrt(s) = 7 TeV,"A search for high-mass resonances decaying into tau-lepton pairs is performed
using a data sample of pp collisions at sqrt(s) = 7 TeV. The data were
collected with the CMS detector at the LHC and correspond to an integrated
luminosity of 4.9 inverse femtobarns. The number of observed events is in
agreement with the standard model prediction. An upper limit on the product of
the resonance cross section and branching fraction into tau-lepton pairs is
calculated as a function of the resonance mass. Using the sequential standard
model resonance Z'(SSM) and the superstring-inspired E(6) model with resonance
Z'(psi) as benchmarks, resonances with standard model couplings with masses
below 1.4 and 1.1 TeV, respectively, are excluded at 95% confidence level.",1206.1725v2
2012-06-30,Kepler-16b: safe in a resonance cell,"The planet Kepler-16b is known to follow a circumbinary orbit around a system
of two main-sequence stars. We construct stability diagrams in the ""pericentric
distance - eccentricity"" plane, which show that Kepler-16b is in a hazardous
vicinity to the chaos domain - just between the instability ""teeth"" in the
space of orbital parameters. Kepler-16b survives, because it is close to the
stable half-integer 11/2 orbital resonance with the central binary, safe inside
a resonance cell bounded by the unstable 5/1 and 6/1 resonances. The
neighboring resonance cells are vacant, because they are ""purged"" by
Kepler-16b, due to overlap of first-order resonances with the planet. The newly
discovered planets Kepler-34b and Kepler-35b are also safe inside resonance
cells at the chaos border.",1207.0101v2
2012-07-09,Multiplet resonance lifetimes in resonant inelastic X-ray scattering involving shallow core levels,"Resonant inelastic X-ray scattering (RIXS) spectra of model copper- and
nickel-based transition metal oxides are measured over a wide range of energies
near the M-edge (h$\nu$=60-80eV) to better understand the properties of
resonant scattering involving shallow core levels. Standard multiplet RIXS
calculations are found to deviate significantly from the observed spectra.
However, by incorporating the self consistently calculated decay lifetime for
each intermediate resonance state within a given resonance edge, we obtain
dramatically improved agreement between data and theory. Our results suggest
that these textured lifetime corrections can enable a quantitative
correspondence between first principles predictions and RIXS data on model
multiplet systems. This accurate model is also used to analyze resonant elastic
scattering, which displays the elastic Fano effect and provides a rough upper
bound for the core hole shake-up response time.",1207.1948v2
2012-10-08,"Resonant, non-resonant, and anomalous states of Dirac electrons in a parabolic well in the presence of magnetic fields","We report on several new basic properties of a parabolic dot in the presence
of a magnetic field. The ratio between the potential strength and the Landau
level (LL) energy spacing serves as the coupling constant of this problem. In
the weak coupling limit the energy spectrum in each Hilbert subspace of an
angular momentum consists of discrete LLs of graphene. In the intermediate
coupling regime non-resonant states form a closely spaced energy spectrum. We
find, counter-intuitively, that resonant quasi-boundstates of both positive and
negative energies exist in the spectrum. The presence of resonant
quasi-boundstates of negative energies are a unique property of massless Dirac
fermions. As the strong coupling limit is approached resonant and non-resonant
states transform into anomalous states, whose probability densities develop a
narrow peak inside the well and another broad peak under the potential barrier.
These properties may investigated experimentally by measuring optical
transition energies that can be described by a scaling function of the coupling
constant.",1210.2341v2
2012-10-08,Slow noise processes in superconducting resonators,"Slow noise processes, with characteristic timescales ~1s, have been studied
in planar superconducting resonators. A frequency locked loop is employed to
track deviations of the resonator centre frequency with high precision and
bandwidth. Comparative measurements are made in varying microwave drive,
temperature and between bare resonators and those with an additional dielectric
layer. All resonators are found to exhibit flicker frequency noise which
increases with decreasing microwave drive. We also show that an increase in
temperature results in a saturation of flicker noise in resonators with an
additional dielectric layer, while bare resonators stop exhibiting flicker
noise instead showing a random frequency walk process.",1210.2351v5
2012-10-15,High-Temperature Superconducting Spiral Resonator for Metamaterial Applications,"This work studies high-temperature superconducting spiral resonators as a
viable candidate for realization of RF/microwave metamaterial atoms. The theory
of superconducting spiral resonators will be discussed in detail, including the
mechanism of resonance, the origin of higher order modes, the analytical
framework for their determination, the effects of coupling scheme, and the
dependence of the resonance quality factor and insertion loss on the parity of
the mode. All the aforementioned models are compared with the experimental data
from a micro-fabricated YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) spiral resonator.
Moreover, the evolution of the resonance characteristics for the fundamental
mode with variation of the operating temperature and applied RF power is
experimentally examined, and its implications for metamaterial applications are
addressed.",1210.4080v1
2012-11-29,"The $p(γ,K^+)Λ$ reaction: consistent high-spin interactions and Bayesian inference of its resonance content","A Bayesian analysis of the world's $p(\gamma,K^+)\Lambda$ data is presented.
We adopt a Regge-plus-resonance framework featuring consistent interactions for
nucleon resonances up to spin $J = 5/2$. The power of the momentum dependence
of the consistent interaction structure rises with the spin of the resonance.
This leads to unphysical structures in the energy dependence of the computed
cross sections when the short-distance physics is cut off with standard
hadronic form factors. A plausible, spin-dependent modification of the hadronic
form factor is proposed which suppresses the unphysical artifacts. Next, we
evaluate all possible combinations of 11 candidate resonances. The best model
is selected from the 2048 model variants by calculating the Bayesian evidence
values against the world's $p(\gamma,K^+)\Lambda$ data. From the proposed
selection of 11 resonances, we find that the following nucleon resonances have
the highest probability of contributing to the reaction: $S_{11}(1535)$,
$S_{11}(1650)$, $F_{15}(1680)$, $P_{13}(1720)$, $D_{13}(1900)$, $P_{13}(1900)$,
$P_{11}(1900)$, and $F_{15}(2000)$.",1211.6896v2
2012-12-03,Neutron resonances in few-body systems and the EOS of neutron star crust,"The effective interactions formed by neutron rescattering between the nuclei
fixed in nodes of the crystalline lattice of neutron star crusts have been
considered. In the case of two-body resonances in neutron-nucleus subsystems
new neutron resonances of few-body nature come into existence in the overdense
crystal under certain conditions. The energies and widths of new resonances get
additional dependence on the lattice parameters. The effective interactions
result in nonlinear correction to the equation of state determined by the
balance of gravitational, Coulomb and nuclear resonance forces. This leads to
resonant oscillations of density in the accordant layers of crusts that are
accompanied by oscillations of gamma radiation. The phenomena may clarify some
processes connected with few-body neutron resonances in neutron star crusts,
that have influence on the microstructure of pulsar impulses.",1212.0393v1
2012-12-16,Stimulated Emission of Radiation in a Single Mode for both Resonance and Non-resonance for Various Initial Photon Distributions,"This paper reexamines the results of Cummings in which the quantum mechanical
two-level-system (TLS) interacts with the electromagnetic field with various
initial distributions and extends that work for both resonant and non-resonant
to times large enough to display multiple photon echoes. The results presented
here include the initial pure coherent state, the field whose initial density
matrix is the Gaussian superposition of coherent states (blackbody radiation)
and density matrices of the field represented by various combinations of mixed
coherent and thermal states with and without squeezing This paper provides, in
addition to the matrix elements to the various states, both the algebraic and
graphical representation for the first order correlation function G=<E+E-> for
resonance and non-resonance. It is found that in all case, the application of
non-resonance leads to oscillations in the first order correlation which was
thought only to apply for the coherent state even for the case of the pure
thermal state.",1212.3752v4
2012-12-21,Detectability of the second resonance of low-scale string models at the LHC,"Low-scale string models are phenomenological models in String Theory, in
which the string scale M_s is of the order of TeV. String excited states which
are characteristic modes in low-scale string models can be observed as
resonances in dijet invariant mass distributions at the LHC. If a new heavy
resonance is discovered at the LHC, it is important to investigate whether the
resonance comes from low-scale string models. In this work, two analyses are
performed: One is observing higher spin degeneracy of string excited states by
an angular distribution analysis on the resonance, since the string resonance
consists of several degenerate states with different spins. The other is
observing second string excited states by a search for a second resonance in
dijet invariant mass distributions, since second string excited states have
characteristic masses of sqrt{2} times of masses of first string excited
states. As the result of Monte Carlo simulations assuming the 14 TeV LHC, we
give required luminosities for 5 sigma confirmation in each analysis, in case
of M_s = 4.5, 4.75 and 5 TeV.",1212.5372v3
2012-12-29,Multi-resonance orbital model of HF QPOs,"Using known frequencies of the twin peak high-frequency quasiperiodic
oscillations (HF QPOs) and known mass M of the central black hole, the
black-hole dimensionless spin a can be determined assuming a concrete version
of the resonance model. However, large range of observationally limited values
of the black hole mass implies a low precision of the spin estimates. We
discuss the possibility of higher precision of the black hole spin measurements
in the framework of multi-resonance model inspired by observations of more than
two HF QPOs in some black hole sources. We determine the spin and mass
dependence of the twin peak frequencies with a general rational ratio n:m
assuming a non-linear resonance of oscillations with the epicyclic and
Keplerian frequencies or their combinations. In the multi-resonant model, the
twin peak resonances are combined properly to give the observed frequency set.
We focus on the special case of duplex frequencies, when the top, bottom, or
mixed frequency is common at two different radii where the resonances occur
giving triple frequency sets.",1212.6668v1
2013-01-15,Resonant Bound-Free Contributions to Thomson Scattering of X-rays by Warm Dense Matter,"Recent calculations [Nilsen et al. arXiv:1212.5972] predict that
contributions to the scattered photon spectrum from 3s and 3p bound states in
chromium (Z=24) at metallic density and T=12 eV resonate below the respective
bound-state thresholds. These resonances are shown to be closely related to
continuum lowering, where 3d bound states in the free atom dissolve into a
resonant l=2 partial wave in the continuum. The resulting d-state resonance
dominates contributions to the bound-free dynamic structure function, leading
to the predicted resonances in the scattered X-ray spectrum. Similar resonant
features are shown to occur in all elements in the periodic table between Ca
and Mn (20 <= Z <= 25).",1301.3440v1
2013-02-21,Resonances on hedgehog manifolds,"We discuss resonances for a nonrelativistic and spinless quantum particle
confined to a two- or three-dimensional Riemannian manifold to which a finite
number of semiinfinite leads is attached. Resolvent and scattering resonances
are shown to coincide in this situation. Next we consider the resonances
together with embedded eigenvalues and ask about the high-energy asymptotics of
such a family. For the case when all the halflines are attached at a single
point we prove that all resonances are in the momentum plane confined to a
strip parallel to the real axis, in contrast to the analogous asymptotics in
some metric quantum graphs; we illustrate it on several simple examples. On the
other hand, the resonance behaviour can be influenced by a magnetic field. We
provide an example of such a `hedgehog' manifold at which a suitable
Aharonov-Bohm flux leads to absence of any true resonance, i.e. that
corresponding to a pole outside the real axis.",1302.5269v1
2013-02-24,Atom Loss Resonances in a Bose-Einstein Condensate,"Atom loss resonances in ultracold trapped atoms have been observed at
scattering lengths near atom-dimer resonances, at which Efimov trimers cross
the atom-dimer threshold, and near two-dimer resonances, at which universal
tetramers cross the dimer-dimer threshold. We propose a new mechanism for these
loss resonances in a Bose-Einstein condensate of atoms. As the scattering
length is ramped to the large final value at which the atom loss rate is
measured, the time-dependent scattering length generates a small condensate of
shallow dimers coherently from the atom condensate. The coexisting atom and
dimer condensates can be described by a low-energy effective field theory with
universal coefficients that are determined by matching exact results from
few-body physics. The classical field equations for the atom and dimer
condensates predict narrow enhancements in the atom loss rate near atom-dimer
resonances and near two-dimer resonances due to inelastic dimer collisions.",1302.5925v1
2013-06-19,Distinguishing Color-Octet and Color-Singlet Resonances at the Large Hadron Collider,"Di-jet resonance searches are simple, yet powerful and model-independent,
probes for discovering new particles at hadron colliders. Once such a resonance
has been discovered it is important to determine the mass, spin, couplings,
chiral behavior and color properties to determine the underlying theoretical
structure. We propose a new variable which, in the absence of decays of the
resonance into new non-standard states, distinguishes between color-octet and
color-singlet resonances. To keep our study widely applicable we study
phenomenological models of color-octet and color-singlet resonances in flavor
universal as well as flavor non-universal scenarios. We present our analysis
for a wide range of mass (2.5 - 6 TeV), couplings and flavor scenarios for the
LHC with center of mass energy of 14 TeV and varying integrated luminosities of
30, 100, 300 and 1000 ${\rm fb}^{-1}$. We find encouraging results to
distinguish color-octet and color-singlet resonances for different flavor
scenarios at the LHC.",1306.4715v1
2013-07-18,Are the Kepler Near-Resonance Planet Pairs due to Tidal Dissipation?,"The multiple-planet systems discovered by the Kepler mission show an excess
of planet pairs with period ratios just wide of exact commensurability for
first-order resonances like 2:1 and 3:2. In principle, these planet pairs could
have both resonance angles associated with the resonance librating if the
orbital eccentricities are sufficiently small, because the width of first-order
resonances diverges in the limit of vanishingly small eccentricity. We consider
a widely-held scenario in which pairs of planets were captured into first-order
resonances by migration due to planet-disk interactions, and subsequently
became detached from the resonances, due to tidal dissipation in the planets.
In the context of this scenario, we find a constraint on the ratio of the
planet's tidal dissipation function and Love number that implies that some of
the Kepler planets are likely solid. However, tides are not strong enough to
move many of the planet pairs to the observed separations, suggesting that
additional dissipative processes are at play.",1307.4874v2
2013-07-24,Rotational bands in the continuum illustrated by $^{8}$Be results,"We use the two-alpha cluster model to describe the properties of $^{8}$Be.
The rotational energy sequence of the $(0^+,2^+,4^+)$ resonances are reproduced
with the complex energy scaling technique for Ali-Bodmer and Buck-potentials.
However, both static and transition probabilities are far from the rotational
values. We trace this observation to the prominent continuum properties of the
$2^+$ and $4^+$ resonances. They resemble free continuum solutions although
still exhibiting strong collective rotational character. We compare with
cluster models and discuss concepts of rotations in the continuum in connection
with central quantities as transition probabilities, inelastic cross sections
and resonance widths. We compute the $6^+$ and $8^+$ $S$-matrix poles and
discuss properties of this possible continuation of the band beyond the known
$4^+$ state. Regularization of diverging quantities are discussed in order to
extract observable continuum properties. We formulate division of
electromagnetic transition probabilities into interfering contributions from
resonance-resonance, continuum-resonance, resonance-continuum, and
continuum-continuum transitions.",1307.6467v1
2013-10-19,Controlled assembly of graphene sheets and nanotubes: fabrication of suspended multi-element all-carbon vibrational structures,"We report on the fabrication and operation of a multi-element vibrational
structure consisting of two graphene mechanical resonators coupled by a
nanotube beam. The whole structure is suspended. Each graphene resonator is
clamped by two metal electrodes. The structure is fabricated using a
combination of electron-beam lithography and atomic-force microscopy
nano-manipulation. This layout allows us to detect the mechanical vibrations
electrically. The measured eigenmodes are localized in either one of the
graphene resonators. The coupling due to the nanotube is studied by measuring
the shift of the resonance frequency of one graphene resonator as a function of
the vibration amplitude of the other resonator. Coupled graphene resonators
hold promise for the study of nonlinear dynamics, the manipulation of
mechanical states, and quantum non-demolition measurements.",1310.5239v1
2013-11-01,Lagrangian tori near resonances of near-integrable Hamiltonian systems,"In this paper we study families of Lagrangian tori that appear in a
neighborhood of a resonance of a near-integrable Hamiltonian system. Such
families disappear in the ""integrable"" limit $\varepsilon\to 0$. Dynamics on
these tori is oscillatory in the direction of the resonance phases and rotating
with respect to the other (non-resonant) phases.
  We also show that, if multiplicity of the resonance equals one, generically
these tori occupy a set of large relative measure in the resonant domains in
the sense that the relative measure of the remaining ""chaotic"" set is of order
$\sqrt\varepsilon$. Therefore for small $\varepsilon > 0$ a random initial
condition in a $\sqrt\varepsilon$-neighborhood of a single resonance occurs
inside this set (and therefore generates a quasi-periodic motion) with a
probability much larger than in the ""chaotic"" set.
  We present results of numerical simulations and discuss the form of
projection of such tori to the action space.",1311.0132v1
2013-12-19,Lyapunov exponents in resonance multiplets,"The problem of estimating the maximum Lyapunov exponents of the motion in a
multiplet of interacting nonlinear resonances is considered for the case when
the resonances have comparable strength. The corresponding theoretical
approaches are considered for the multiplets of two, three, and infinitely many
resonances (i.e., doublets, triplets, and ""infinitets""). The analysis is based
on the theory of separatrix and standard maps. A ""multiplet separatrix map"" is
introduced, valid for description of the motion in the resonance multiplet
under certain conditions. In numerical experiments it is shown that, at any
given value of the adiabaticity parameter (which controls the degree of
interaction/overlap of resonances in the multiplet), the value of the maximum
Lyapunov exponent in the multiplet of equally-spaced equally-sized resonances
is minimal in the doublet case and maximal in the infinitet case. This is
consistent with the developed theory.",1312.5560v1
2013-12-20,A superconducting circuit probe for analog quantum simulators,"Analog quantum simulators can be used to study quantum correlation in novel
many-body systems by emulating the Hamiltonian of these systems. One essential
question in quantum simulation is to probe the properties of an emulated
many-body system. Here we present a circuit QED scheme for probing such
properties by measuring the spectrum of a superconducting resonator coupled to
a quantum simulator. We first study a general framework of this approach, and
show that the spectrum of the resonator is directly related to the correlation
function of the coupling operator between the resonator and the simulator. We
then apply this scheme to a simulator of the transverse field Ising model
implemented with superconducting qubits, where the resonance peaks in the
resonator spectrum correspond to the frequencies of the elementary excitations.
The effects of resonator damping, qubit decoherence, and resonator backaction
are also discussed. This setup can be used to probe a broad range of many-body
models.",1312.6152v2
2013-12-22,Observation of low-field Fano-Feshbach resonances in ultracold gases of dysprosium,"We report the observation of resonance-like loss in the trap population of
ultracold dysprosium as a function of magnetic field, which we attribute to
anisotropy-induced Fano-Feshbach resonances arising from Dy's large magnetic
dipole moment and nonzero electronic orbital angular momentum. We recorded
these resonances for four different isotopes, three bosonic and one fermionic,
over a field range of 0-6 G and show that the number of resonances changes
significantly as a function of temperature, even in the nK regime. Most of the
observed resonances are of very narrow width. The fermionic isotope, unlike its
bosonic counterparts, possesses nonzero nuclear spin and exhibits a much higher
density of resonances.",1312.6401v1
2014-02-12,"Nuclear magnetic resonances in (In,Ga)As/GaAs quantum dots studied by resonant optical pumping","The photoluminescence polarizations of (In,Ga)As/GaAs quantum dots annealed
at different temperatures are studied as a function of external magnetic field
(Hanle curves). In these dependencies, remarkable resonant features appear due
to all-optical nuclear magnetic resonances (NMR) for optical excitation with
modulated circular polarization. Application of an additional radio-frequency
field synchronously with the polarization modulation strongly modifies the NMR
features. The resonances can be related to transitions between different
nuclear spin states split by the strain-induced gradient of the crystal field
and by the externally applied magnetic field. A theoretical model is developed
to simulate quadrupole and Zeeman splittings of the nuclear spins in a strained
quantum dot. Comparison with the experiment allows us to uniquely identify the
observed resonances. The large broadening of the NMR resonances is attributed
to variations of the quadrupole splitting within the quantum dot volume, which
is well described by the model.",1402.2727v2
2014-02-13,Three-body model calculations of Nucleon-Delta and Delta-Delta dibaryon resonances,"Three-body hadronic models with separable pairwise interactions are
formulated and solved to calculate resonance masses and widths of L=0 N-Delta
and Delta-Delta dibaryons using relativistic kinematics. For N-Delta,
I(JP)=1(2+) and 2(1+) resonances slightly below threshold are found by solving
pi-N-N Faddeev equations. For Delta-Delta, several resonances below threshold
are found by solving pi-N-Delta Faddeev equations in which the N-Delta
interaction is dominated by the 1(2+) and 2(1+) resonating channels. The lowest
Delta-Delta dibaryon resonances found are for I(JP)=0(3+) and 3(0+), the former
agreeing well both in mass and in width with the relatively narrow D_{03}(2370)
resonance observed recently by the WASA-at-COSY Collaboration. Its spin-isospin
symmetric partner D_{30} is predicted with mass around 2.4 GeV and width about
80 MeV.",1402.3171v2
2014-04-14,Non-Abelian dynamics in the resonant decay of the Higgs after inflation,"We study the resonant decay of the Higgs condensate into weak gauge bosons
after inflation and estimate the corrections arising from the non-Abelian
self-interactions of the gauge fields. We find that non-Abelian interaction
terms induce an effective mass which tends to shut down the resonance. For the
broad resonance relevant for the Standard Model Higgs the produced gauge
particles backreact on the dynamics of the Higgs condensate before the
non-Abelian terms grow large. The non-Abelian terms can however significantly
affect the final stages of the resonance after the backreaction. In the narrow
resonance regime, which may be important for extensions of the Standard Model,
the non-Abelian terms affect already the linear stage and terminate the
resonance before the Higgs condensate is affected by the backreaction of decay
products.",1404.3631v2
2014-07-22,Phase-controlled Fano resonance by the nanoscale optomechanics,"Observation of the Fano line shapes is essential to understand properties of
the Fano resonance in different physical systems. We explore a tunable Fano
resonance by tuning the phase shift in a Mach-Zehnder interferometer (MZI)
based on a single-mode nano-optomechanical cavity. The Fano resonance is
resulted from the optomechanically induced transparency caused by a
nano-mechanical resonator and can be tuned by applying an optomechanical MZI.
By tuning the phase shift in one arm of the MZI, we can observe the
periodically varying line shapes of the Fano resonance, which represents an
elaborate manipulation of the Fano resonance in the nanoscale optomechanics.",1407.5746v2
2014-08-07,Polaritonic Feshbach Resonance,"A Feshbach resonance occurs when the energy of two interacting free particles
comes to resonance with a molecular bound state. When approaching this
resonance, dramatic changes in the interaction strength between the particles
occur. Feshbach resonances have been an essential tool to control the atom
interactions, which can even be switched from repulsive to attractive [1-4].
Thanks to Feshbach resonances many effects in ultracold atomic gases could be
explored [5, 6]. Here we demonstrate a Feshbach resonance based on polariton
spinor interactions that characterize the fundamental interaction process in
polariton quantum systems. We show the clear enhancement of attractive
interactions and the prompt change to repulsive interaction by tuning the
energy of two polaritons with anti-parallel spins across the biexciton bound
state energy. A mean field two-channel model quantitatively reproduces the
experimental results. This observation paves the way for a new tool to tune the
polariton interactions and to move forward into quantum correlated polariton
physics.",1408.1499v2
2014-10-16,Recent development of complex scaling method for many-body resonances and continua in light nuclei,"The complex scaling method (CSM) is a useful similarity transformation of the
Schr\""odinger equation, in which bound-state spectra are not changed but
continuum spectra are separated into resonant and non-resonant continuum ones.
Because the asymptotic wave functions of the separated resonant states are
regularized by the CSM, many-body resonances can be obtained by solving an
eigenvalue problem with the $L^2$ basis functions. Applying this method to a
system consisting of a core and valence nucleons, we investigate many-body
resonant states in weakly bound nuclei very far from the stability lines.
Non-resonant continuum states are also obtained with the discretized
eigenvalues on the rotated branch cuts. Using these complex eigenvalues and
eigenstates in CSM, we construct the extended completeness relations and
Green's functions to calculate strength functions and breakup cross sections.
Various kinds of theoretical calculations and comparisons with experimental
data are presented.",1410.4356v1
2014-10-21,Observation of orbiting resonances in He(3S1) + NH3 Penning ionization,"Resonances are among the clearest quantum mechanical signatures of scattering
processes. Previously, shape resonances and Feshbach resonances have been
observed in inelastic and reactive collisions involving atoms or diatomic
molecules. Structure in the integral cross section has been observed in a
handful of elastic collisions involving polyatomic molecules. The present paper
presents the observation of shape resonances in the reactive scattering of a
polyatomic molecule, NH3. A merged-beam study of the gas phase He((3)S1) + NH3
Penning ionization reaction dynamics is described in the collision energy range
3.3 $\mu$eV < E$_{coll}$ < 10 meV. In this energy range, the reaction rate is
governed by long-range attraction. Peaks in the integral cross section are
observed at collision energies of 1.8 meV and 7.3 meV and are assigned to $\ell
= 15,16$ and $\ell = 20,21$ partial wave resonances, respectively. The
experimental results are well reproduced by theoretical calculations with the
short-range reaction probability P$_{sr}$ = 0.035. No clear signature of the
orbiting resonances is visible in the branching ratio between NH3(+) and NH2(+)
formation.",1410.5651v2
2014-10-24,Multi-frequency modes in superconducting resonators: Bridging frequency gaps in off-resonant couplings,"A Superconducting Quantum Interference Device (SQUID) inserted in a
superconducting waveguide resonator imposes current and voltage boundary
conditions that makes it suitable as a tuning element for the resonator modes.
If such a SQUID element is subject to a periodically varying magnetic flux, the
resonator modes acquire frequency side bands. In this work we calculate the
multi-frequency eigenmodes of resonators coupled to periodically driven SQUIDs
and we use the Lagrange formalism to propose a theory for their quantization.
The elementary excitations of a multi-frequency mode can couple resonantly to
physical systems with different transition frequencies and this makes the
resonator an efficient quantum bus for state transfer and coherent quantum
operations in hybrid quantum systems. As an example of the application of our
multi-frequency modes, we determine their coupling to transmon qubits with
different frequencies and we present a bi-chromatic scheme for entanglement and
gate operations.",1410.6644v1
2014-11-21,Electrodynamics of a planar Archimedean spiral resonator,"We present a theoretical and experimental study of electrodynamics of a
planar spiral superconducting resonator of a finite length. The resonator is
made in the form of a monofilar Archimedean spiral. By making use of a general
model of inhomogeneous alternating current flowing along the resonator and
specific boundary conditions on the surface of the strip, we obtain
analytically the frequencies $f_n$ of resonances which can be excited in such
system. We also calculate corresponding inhomogeneous RF current distributions
$\psi_n (r)$, where $r$ is the coordinate across a spiral. We show that the
resonant frequencies and current distributions are well described by simple
relationships $f_n=f_1 n$, and $\psi_n(r)\simeq \sin[\pi n (r/R_e)^2]$, where
$n=1,2...$, and $R_e$ is the external radius of the spiral. Our analysis of
electrodynamic properties of spiral resonators' is in good accord with direct
numerical simulations and measurements made using specifically designed
magnetic probe and laser scanning microscope.",1411.5823v1
2014-12-23,Asymptotic model for shape resonance control of diatomics by intense non-resonant light: Universality in the single-channel approximation,"Non-resonant light interacting with diatomics via the polarizability
anisotropy couples different rotational states and may lead to strong
hybridization of the motion. The modification of shape resonances and
low-energy scattering states due to this interaction can be fully captured by
an asymptotic model, based on the long-range properties of the scattering
[Crubellier et al. arXiv:1412.0569]. Remarkably, the properties of the
field-dressed shape resonances in this asymptotic multi-channel description are
found to be approximately linear in the field intensity up to fairly large
intensity. This suggests a perturbative single-channel approach to be
sufficient to study the control of such resonances by the non-resonant field.
The multi-channel results furthermore indicate the dependence on field
intensity to present, at least approximately, universal characteristics. Here
we combine the nodal line technique to solve the asymptotic Schr\""odinger
equation with perturbation theory. Comparing our single channel results to
those obtained with the full interaction potential, we find nodal lines
depending only on the field-free scattering length of the diatom to yield an
approximate but universal description of the field-dressed molecule, confirming
universal behavior.",1412.7315v1
2015-01-03,Instrument for in-situ orientation of superconducting thin-film resonators used for electron-spin resonance experiments,"When used in Electron-Spin Resonance (ESR) measurements, superconducting
thin-film resonators must be precisely oriented relative to the external
magnetic field in order to prevent the trapping of magnetic flux and the
associated degradation of resonator performance. We present a compact design
solution for this problem that allows in-situ control of the orientation of the
resonator at cryogenic temperatures. Tests of the apparatus show that when
proper alignment is achieved, there is almost no hysteresis in the field
dependence of the resonant frequency.",1501.01596v2
2015-02-02,Impact load mitigation in sandwich beams using local resonators,"Dynamic response of sandwich beams with resonators embedded in the cores
subjected to impact loads is studied. Using finite element models the
effectiveness of various local resonator frequencies under a given impact load
is compared to the behavior of an equivalent mass beam. It is shown that
addition of appropriately chosen local resonators into the sandwich beam is an
effective method of improving its flexural bending behavior under impact loads.
The effect of a given local resonance frequency under different impact load
durations is also studied. It is demonstrated that the choice of appropriate
local resonance frequency depends on the impact duration. Further, by
performing transverse impact experiments, the finite element models are
verified and the advantage of using internal resonators under impact loading
conditions is demonstrated.",1502.00574v1
2015-02-12,Fano Resonance in the Nonadiabatically Pumped Shot Noise of a Time-Dependent Quantum Well in 2DEG and Graphene,"Interference between different quantum paths can generate Fano resonance. One
of the examples is transport through a quasibound state driven by
time-dependent scattering potential. Previously it is found that Fano resonance
occurs as a result of energy matching in one-dimensional systems. In this work,
we demonstrate that when transverse motion is present, Fano resonance occurs
precisely at the wavevector matching situation. Using the Floquet scattering
theory, we considered the transport properties of a nonadiabatic time-dependent
well both in the 2DEG and monolayer graphene structure. Dispersion of the
quasibound state of a static quantum well is obtained with transverse motion
present. We found that Fano resonance occurs when the wavevector in the
transport direction of one of the Floquet sidebands is exactly identical to
that of the quasibound state in the well at equilibrium and follows the
dispersion pattern of the latter. To observe the Fano resonance phenomenon in
the transmission spectrum, we also considered the pumped shot noise properties
when time and spatial symmetry secures vanishing current in the considered
configuration. Prominent Fano resonance is found in the differential pumped
shot noise to the reservoir Fermi energy.",1502.03844v1
2015-02-19,$S$-wave resonance contributions to the $B^0_{(s)}\to J/ψπ^+π^-$ and $B_s\toπ^+π^-μ^+μ^-$ decays,"We study $S$-wave resonance contributions to the $B^0_{(s)}\to
J/\psi\pi^+\pi^-$ and $B_s\to\pi^+\pi^-\ell^+\ell^-$ decays in the perturbative
QCD (PQCD) framework by introducing two-hadron distribution amplitudes for
final states. The Breit-Wigner formula for the $f_0(500)$, $f_0(1500)$ and
$f_0(1790)$ resonances and the Flatt\'e model for the $f_0(980)$ resonance are
adopted to parameterize the time-like scalar form factors in the two-pion
distribution amplitudes, which include both resonant and nonresonant
contributions. The resultant branching fraction and differential branching
fraction in the pion-pair invariant mass for each resonance channel are
consistent with experimental data. The determined $S$-wave two-pion
distribution amplitudes, containing the information of both resonant and
nonresonant rescattering phases, can be employed to predict direct CP
asymmetries of other three-body hadronic $B$ meson decays in various localized
regions of two-pion phase space.",1502.05483v3
2015-02-23,Tuning the optical forces on- and off-resonance in microspherical photonics,"Light pressure effect has been discovered long ago and has been used as an
optical method to manipulate microand nanoparticles. It is usually considered
as a nonresonant effect determined by the transfer of the momentum of light.
However, recently we have observed that large polystyrene microspheres of 15-20
{\mu}m diameters supporting high quality whispering gallery resonances can be
optically propelled in water at an extraordinary high velocity along tapered
fibers under resonant conditions. In this work we compare on- and off-resonant
optical forces in microspherical photonics by controlling the detuning between
the laser emission line and whispering gallery resonances. Our approach
involves manipulation with microspheres using conventional optical tweezers and
their advanced spectroscopic characterization in fiber-integrated setups. We
demonstrate dramatic difference in the optical forces exerted on microspheres
in the on-resonant and off-resonant cases. This method can be used to study
spectral properties of the resonantly enhanced forces in microspherical
photonics.",1502.06294v1
2015-02-23,Spectrally resolved resonant propulsion of dielectric microspheres,"Use of resonant light forces opens up a unique approach to high-volume
sorting of microspherical resonators with much higher uniformity of resonances
compared to that in coupled-cavity structures obtained by the best
semiconductor technologies. In this work, the spectral response of the
propulsion forces exerted on polystyrene microspheres near tapered microfibers
is directly observed. The measurements are based on the control of the detuning
between the tunable laser and internal resonances in each sphere with accuracy
higher than the width of the resonances. The measured spectral shape of the
propulsion forces correlates well with the whispering-gallery mode resonances
in the microspheres. The existence of a stable radial trap for the microspheres
propelled along the taper is demonstrated. The giant force peaks observed for
20-{\mu}m spheres are found to be in a good agreement with a model calculation
demonstrating an efficient use of the light momentum for propelling the
microspheres.",1502.06295v1
2015-03-31,Nanotube mechanical resonators with quality factors of up to 5 million,"Carbon nanotube mechanical resonators have attracted considerable interest
because of their small mass, the high quality of their surface, and the
pristine electronic states they host. However, their small dimensions result in
fragile vibrational states that are difficult to measure. Here we observe
quality factors $Q$ as high as $5\times10^6$ in ultra-clean nanotube resonators
at a cryostat temperature of 30 mK, where we define $Q$ as the ratio of the
resonant frequency over the linewidth. Measuring such high quality factors
requires both employing an ultra-low noise method to detect minuscule
vibrations rapidly, and carefully reducing the noise of the electrostatic
environment. We observe that the measured quality factors fluctuate because of
fluctuations of the resonant frequency. The quality factors we measure are
record high; they are comparable to the highest $Q$ reported in mechanical
resonators of much larger size, a remarkable result considering that reducing
the size of resonators is usually concomitant with decreasing quality factors.
The combination of ultra-low size and very large $Q$ offers new opportunities
for ultra-sensitive detection schemes and quantum optomechanical experiments.",1503.09155v1
2015-04-16,Vibrational Resonance in the Duffing Oscillator with Distributed Time-Delayed Feedback,"We analyze the vibrational resonance in the Duffing oscillator system in the
presence of (i) a gamma distributed time-delayed feedback and (ii) integrative
time-delayed (uniformly distributed time delays over a finite interval)
feedback. Particularly, applying a theoretical procedure we obtain an
expression for the response amplitude $Q$ at the low-frequency of the driving
biharmonic force. For both double-well potential and single-well potential
cases we are able to identify the regions in parameter space where either (i)
two resonances, (ii) a single resonance or (iii) no resonance occur.
Theoretically predicted values of $Q$ and the values of a control parameter at
which resonance occurs are in good agreement with our numerical simulation. The
analysis shows a strong influence of both types of time-delayed feedback on
vibrational resonance.",1504.04163v1
2015-05-04,Multipole plasmons and their disappearance in few-nanometer silver nanoparticles,"In electron energy-loss spectroscopy (EELS) of individual silver
nanoparticles encapsulated in silicon nitride, we observe besides the usual
dipole resonance an additional surface plasmon (SP) resonance corresponding to
higher angular momenta. We even observe both resonances for nanoparticle radii
as small as 4 nm, where previously only the dipole resonance was assumed to
play a role. Electron beams positioned outside of the particles mostly excite
the dipole mode, but the higher-order resonance can even dominate the dipole
peak when exciting at the particle surface, the usual choice for maximal EELS
signal. This allows us to study the radius dependence of both resonances
separately. For particles smaller than 4 nm, the higher-order SP mode
disappears, in agreement with generalized nonlocal optical response (GNOR)
theory, while the dipole resonance blueshift exceeds GNOR predictions. Unlike
in optical spectra, multipole surface plasmons are important in EELS spectra
even of ultra-small metallic nanoparticles.",1505.00594v1
2015-05-15,Tunable dynamic Fano resonances in coupled-resonant optical waveguide,"A route toward lineshape engineering of Fano resonances in photonic
structures is theoretically proposed, which uses dynamic modulation of the
refractive index of a microcavity. The method is exemplified by considering
coupled-resonator optical waveguide systems. An exact Floquet analysis, based
on coupled-mode theory, is presented. Two distinct kinds of resonances can be
dynamically created, depending on whether the static structure sustains a
localized mode or not. In the former case a single Fano resonance arises, which
can be tuned in both frequency and line width by varying the refractive index
modulation amplitude and frequency. In the latter case two resonances, in the
form of narrow asymmetric dips in the transmittance, are found, which can
overlap resulting in an electromagnetically-induced transparency effect.",1505.04138v1
2015-05-18,High-Q Tantalum Oxide Nanomechanical Resonators by Laser-Oxidation of TaSe2,"Controlling the strain in two-dimensional materials is an interesting avenue
to tailor the mechanical properties of nanoelectromechanical systems. Here we
demonstrate a technique to fabricate ultrathin tantalum oxide nanomechanical
resonators with large stress by laser-oxidation of nano-drumhead resonators
made out of tantalum diselenide (TaSe2), a layered 2D material belonging to the
metal dichalcogenides. Prior to the study of their mechanical properties with a
laser interferometer, we checked the oxidation and crystallinity of the
freely-suspended tantalum oxide in a high-resolution electron microscope. We
show that the stress of tantalum oxide resonators increase by 140 MPa (with
respect to pristine TaSe2 resonators) which causes an enhancement of quality
factor (14 times larger) and resonance frequency (9 times larger) of these
resonators.",1505.04727v2
2015-06-03,Migration of two massive planets into (and out of) first order mean motion resonances,"We consider the dynamical evolution of two planets orbiting in the vicinity
of a first order mean motion reso- nance while simultaneously undergoing
eccentricity damping and convergent migration. Following Goldreich &
Schlichting (2014), we include a coupling between the dissipative semimajor
axis evolution and the damping of the eccentricities. In agreement with past
studies, we find that this coupling can lead to overstability of the resonance
and that for a certain range of parameters capture into resonance is only
temporary. Using a more general model, we show that whether overstable motion
can occur depends in a characteristic way on the mass ratio between the two
planets as well as their relative eccentricity damping timescales. Moreover, we
show that even when escape from resonance does occur, the timescale for escape
is long enough such at any given time a pair of planets is more likely to be
found in a resonance rather than migrating between them. Thus, we argue that
overstability of resonances cannot singlehandedly reconcile convergent
migration with the observed lack of Kepler planet pairs found near resonances.
However, it is possible that overstable motion in combination with other
effects such as large scale orbital instability could produce the observed
period ratio distribution.",1506.01382v1
2015-06-05,Controllable coupling between a nanomechanical resonator and a coplanar-waveguide resonator via a superconducting flux qubit,"We study a tripartite quantum system consisting of a coplanar-waveguide (CPW)
resonator and a nanomechanical resonator (NAMR) connected by a flux qubit,
where the flux qubit has a large detuning from both resonators. By a unitray
transformation and a second-order approximation, we obtain a strong and
controllable (i.e., magnetic-field-dependent) effective coupling between the
NAMR and the CPW resonator. Due to the strong coupling, vacuum Rabi splitting
can be observed from the voltage-fluctuation spectrum of the CPW resonator. We
further study the properties of single photon transport as inferred from the
reflectance or equivalently the transmittance. We show that the reflectance and
the corresponding phase shift spectra both exhibit doublet of narrow spectral
features due to vacuum Rabi splitting. By tuning the external magnetic field,
the reflectance and the phase shift can be varied from 0 to 1 and $-\pi$ to
$\pi$, respectively. The results indicate that this hybrid quantum system can
act as a quantum router.",1506.01801v2
2015-06-24,"The Resonator Banjo Resonator, part 2: What makes them really crack?","A simple experiment quantifies the difference between the sound production of
a banjo with and without a resonator back. Driven by a small tweeter mounted
inside the pot, for frequencies above about 4500 Hz, the produced external
sound is 6 to 10 dB louder with the resonator than without. With the banjo
played in any normal fashion, this gives a negligible contribution to the
overall volume. However, that difference is clearly a reflection of the
universally recognized resonator sound, in close analogy to plosive consonants
in human speech. No direct correlation is observed between the head-resonator
separation and the spectrum of the enhanced response. This suggests that direct
reflection off the back is not a primary contributor to the resonator/openback
difference, leaving differences in overall absorption as the major suspect.",1506.07457v1
2015-06-27,K*0(892) and phi(1020) resonance production at RHIC,"The measurement of resonance production in ultrarelativistic heavy-ion
collisions provides a glimpse of the hadronic medium properties and its
evolution at different stages. Resonances decaying into hadrons are used to
estimate the time span and hadronic interaction cross section in the hadronic
phase between chemical and kinetic freeze-out. Specifically, the comparison of
K*0(892) and phi(1020) resonances is interesting as the lifetimes of these
particles differ by about a factor of 10. Moreover, the nuclear modification
factor and azimuthal anisotropy measurements of mesonic resonances, which
measure parton energy loss in medium and reflect partonic collectivity, can
also probe particle-species and mass ordering.
  The K*0(892) and phi(1020) resonance production at mid-rapidity (|y|<0.5),
measured in high energy (Au+Au, Cu+Cu, d+Au and p+p) collisions at RHIC with
STAR experiment, reconstructed by their hadronic decay in Kpi and KK,
respectively, are discussed. Mesons' spectra, yields, mean transverse momentum,
nuclear modification factor, and azimuthal anisotropy are discussed as a
function of centrality and collision energy.",1506.08289v1
2015-07-21,Separating Dijet Resonances Using the Color Discriminant Variable,"Color-singlet and color-octet vector bosons predicted in theories beyond the
Standard Model have the potential to be discovered as dijet resonances at the
LHC. A color-singlet resonance that has leptophobic couplings needs further
investigation to be distinguished from a color-octet one. In previous work, we
introduced a method for discriminating between the two kinds of resonances when
their couplings are flavor-universal, using measurements of the dijet resonance
mass, total decay width and production cross-section. Here, we describe two
extensions of that work. First, we broaden the method to the case where the
vector resonances have flavor non-universal couplings, by incorporating
measurements of the heavy-flavor decays of the resonance. Second, we apply the
method to separating vector bosons from color-octet scalars and excited quarks.",1507.05868v1
2015-08-05,Resonant inverse Faraday effect in nanorings,"A circularly polarized light can induce a dissipationless dc current in a
quantum nanoring which is responsible for a resonant helicity-driven
contribution to magnetic moment. This current is not suppressed by thermal
averaging despite its quantum nature. We refer to this phenomenon as the
quantum resonant inverse Faraday effect. For weak electromagnetic field, when
the characteristic coupling energy is small compared to the energy level
spacing, we predict narrow resonances in the circulating current and,
consequently, in the magnetic moment of the ring. For strong fields, the
resonances merge into a wide peak with a width determined by the spectral
curvature. We further demonstrate that weak short-range disorder splits the
resonances and induces additional particularly sharp and high resonant peaks in
dc current and magnetization. In contrast, long-range disorder leads to a
chaotic behavior of the system in the vicinity of the separatrix that divides
the phase space of the system into regions with dynamically localized and
delocalized states.",1508.01159v2
2015-08-11,Effects of molecular resonances on Rydberg blockade,"We study the effect of resonances associated with complex molecular
interaction of Rydberg atoms on Rydberg blockade. We show that densely-spaced
molecular potentials between doubly-excited atomic pairs become unavoidably
resonant with the optical excitation at short interatomic separations. Such
molecular resonances limit the coherent control of individual excitations in
Rydberg blockade. As an illustration, we compute the molecular interaction
potentials of Rb atoms near the $100s$ states asymptote to characterize such
detrimental molecular resonances, determine the resonant loss rate to molecules
and inhomogeneous light shifts. Techniques to avoid the undesired effect of
molecular resonances are discussed.",1508.02480v1
2015-08-26,Probabilistic interpretation of compositeness relation for resonances,"Bound, antibound and resonance states are associated to poles in the on-shell
partial wave amplitudes. We show here that from the residues of the pole a rank
1 projection operator associated with any of these states can be extracted, in
terms of which a sum rule related to the composition of the state can be
derived. Although typically it involves complex coefficients for the
compositeness and elementariness, except for the bound state case, we
demonstrate that one can formulate a meaningful compositeness relation with
only positive coefficients for resonances whose associated Laurent series in
the variable s converges in a region of the physical axis around Re(s_P), with
s_P the pole position of the resonance. It is also shown that this result can
be considered as an analytical extrapolation in s_P of the clear narrow
resonance case. We exemplify this formalism to study the two-body components of
several resonances of interest.",1508.06400v2
2015-09-14,Scattering resonances for highly oscillatory potentials,"We study resonances of compactly supported potentials $ V_\varepsilon = W (
x, x/\varepsilon ) $ where $ W : \mathbb{R}^d \times \mathbb{R}^d / ( 2\pi
\mathbb{Z}) ^d \to \mathbb{C} $, $ d $ odd. That means that $ V_\varepsilon $
is a sum of a slowly varying potential, $ W_0 ( x) $, and one oscillating at
frequency $1/\varepsilon$. For $ W_0 \equiv 0 $ we prove that there are no
resonances above the line $\text{Im} \lambda = -A \ln(\varepsilon^{-1})$,
except possibly a simple resonance of modulus $\sim \varepsilon^2$, when $
d=1$. We show that this result is optimal by constructing a one-dimensional
example. In the case when $ W_0 \neq 0 $ we prove that resonances in fixed
strips admit an expansion in powers of $\varepsilon$. The argument provides a
method for computing the coefficients of the expansion. In particular we
produce an effective potential converging uniformly to $W_0$ as $\varepsilon
\rightarrow 0$ and whose resonances approach resonances of $V_\varepsilon$
modulo $O(\varepsilon^4)$.",1509.04198v3
2015-09-18,Resonant and Non-Local Properties of Phononic Metasolids,"We derive a general theory of effective properties in metasolids based on
phononic crystals with low frequency resonances. We demonstrate that in general
these structures need to be described by means of a frequency-dependent and
non-local anisotropic mass density, stiffness tensor and a third- rank coupling
tensor, which shows that they behave like a non-local Willis medium. The effect
of non-locality and coupling tensor manifest themselves for some particular
resonances whereas they become negligible for other resonances. Considering the
example of a two-dimensional phononic crystal, consisting of triangular
arrangements of cylindrical shells in an elastic matrix, we show that its mass
density tensor is strongly resonant and anisotropic presenting both positive
and negative divergent values, while becoming scalar in the quasi-static limit.
Moreover, it is found that the negative value of transverse component of the
mass density is induced by a dipolar resonance, while that of the vertical
component is induced by a monopolar one. Finally, the dispersion relation
obtained by the effective parameters of the crystal is compared with the band
structure, showing a good agreement for the low-wave number region, although
the non-local effects are important given the existence of some resonant values
of the wave number.",1509.05522v1
2015-09-29,Weak charged and neutral current induced one pion production off the nucleon,"We present a study of neutrino/antineutrino induced charged and neutral
current single pion production off the nucleon. For this, we have considered
$P_{33}(1232)$ resonance, non-resonant background terms, other higher
resonances like $P_{11}(1440)$, $S_{11}(1535)$, $D_{13}(1520)$, $S_{11}(1650)$
and $P_{13}(1720)$. For the non-resonant background terms a microscopic
approach based on SU(2) non-linear sigma model has been used. The vector form
factors for the resonances are obtained by using the relationship between the
electromagnetic resonance form factors and helicity amplitudes provided by
MAID. Axial coupling $C_5^{A}(0)$ in the case of $P_{33}(1232)$ resonance is
obtained by fitting the ANL and BNL $\nu$-deuteron reanalyzed scattering data.
The results are presented with and without deuteron effect for the total
scattering cross sections for all possible channels viz.
$\nu_l(\bar\nu_l)~+~N\rightarrow l^-(l^+)~+~N^\prime~+~\pi^i$;
$\nu_l(\bar\nu_l)~+~N\rightarrow \nu_l(\bar\nu_l)~+~N^\prime~+~\pi^i$, where
$N, N^\prime=p,n$, $\pi^i=~\pi^\pm$ or $\pi^0$ and $l=e, \mu$.",1509.08622v1
2015-10-23,Geometry-Invariant Resonant Cavities,"Resonant cavities are one of the basic building blocks in various disciplines
of science and technology, with numerous applications ranging from abstract
theoretical modeling to everyday life devices. The eigenfrequencies of
conventional cavities are a function of its geometry, and, thus, the size and
shape of a resonant cavity is selected in order to operate at a specific
frequency. Here, we demonstrate theoretically the existence of
geometry-invariant resonant cavities, i.e., resonators whose eigenfrequency is
invariant with respect to geometrical deformations. This effect is obtained by
exploiting the unusual properties of zero-index metamaterials, which enable
decoupling of the time and spatial field variations. This new class of
resonators may inspire alternative design concepts, and it might lead to the
first generation of deformable resonant devices.",1510.07005v1
2015-11-30,Substrate-Independent Light Confinement in Bioinspired All-Dielectric Surface Resonators,"Traditionally, photonic crystal slabs can support resonances that are
strongly confined to the slab but also couple to external radiation. However,
when a photonic crystal slab is placed on a substrate, the resonance modes
become less confined, and as the index contrast between slab and substrate
decreases, they eventually disappear. Using the scale structure of the Dione
juno butterfly wing as an inspiration, we present a low-index zigzag surface
structure that supports resonance modes even without index contrast with the
substrate. The zigzag structure supports resonances that are contained away
from the substrate, which reduces the interaction between the resonance and the
substrate. We experimentally verify the existence of substrate-independent
resonances in the visible wavelength regime. Potential applications include
substrate-independent structural color and light guiding.",1511.09160v2
2016-02-05,Origin of the chaotic motion of the Saturnian satellite Atlas,"We revisit the dynamics of Atlas. Using Cassini ISS astrometric observations
spanning February 2004 to August 2013, Cooper et al. (2015) found evidence that
Atlas is currently perturbed by both a 54:53 corotation eccentricity resonance
(CER) and a 54:53 Lindblad eccentricity resonance (LER) with Prometheus. They
demonstrated that the orbit of Atlas is chaotic, with a Lyapunov time of order
10 years, as a direct consequence of the coupled resonant interaction (CER/LER)
with Prometheus. Here we investigate the interactions between the two
resonances using the CoraLin analytical model (El Moutamid et al. 2014),
showing that the chaotic zone fills almost all the corotation sites occupied by
the satellite's orbit. Four 70:67 apse-type mean motion resonances with Pandora
are also overlapping, but these resonances have a much weaker effect. Frequency
analysis allows us to highlight the coupling between the 54:53 resonances, and
confirms that a simplified system including the perturbations due to Prometheus
and Saturn's oblateness only captures the essential features of the dynamics.",1602.01967v1
2016-02-15,Disruption of Planetary Orbits Through Evection Resonance with an External Companion: Circumbinary Planets and Multiplanet Systems,"Planets around binary stars and those in multiplanet systems may experience
resonant eccentricity excitation and disruption due to perturbations from a
distant stellar companion. This ""evection resonance"" occurs when the apsidal
precession frequency of the planet, driven by the quadrupole associated with
the inner binary or the other planets, matches the orbital frequency of the
external companion. We develop an analytic theory to study the effects of
evection resonance on circumbinary planets and multiplanet systems. We derive
the general conditions for effective eccentricity excitation or resonance
capture of the planet as the system undergoes long-term evolution. Applying to
circumbinary planets, we show that inward planet migration may lead to
eccentricity growth due to evection resonance with an external perturber, and
planets around shrinking binaries may not survive the resonant eccentricity
growth. On the other hand, significant eccentricity excitation in multiplanet
systems occurs in limited parameter space of planet and binary semimajor axes,
and requires the planetary migration to be sufficiently slow.",1602.04751v1
2016-02-15,A numerical investigation of coorbital stability and libration in three dimensions,"Motivated by the dynamics of resonance capture, we study numerically the
coorbital resonance for inclination180 >=I>=0 in the circular restricted
three-body problem. We examine the similarities and differences between planar
and three dimensional coorbital resonance capture and seek their origin in the
stability of coorbital motion at arbitrary inclination. After we present
stability maps of the planar prograde and retrograde coorbital resonances, we
characterize the new coorbital modes in three dimensions. We see that
retrograde mode I (R1) and mode II (R2) persist as we change the relative
inclination, while retrograde mode III (R3) seems to exist only in the planar
problem. A new coorbital mode (R4) appears in 3D which is a retrograde analogue
to an horseshoe-orbit. The Kozai-Lidov resonance is active for retrograde
orbits as well as prograde orbits and plays a key role in coorbital resonance
capture. Stable coorbital modes exist at all inclinations, including retrograde
and polar obits. This result confirms the robustness the coorbital resonance at
large inclination and encourages the search for retrograde coorbital companions
of the solar system's planets.",1602.04755v1
2016-03-08,Bound and scattering states in harmonic waveguides in the vicinity of free space Feshbach resonances,"The two-body bound and scattering properties in an one-dimensional harmonic
waveguide close to free space magnetic Feshbach resonances are investigated
based on the local frame transformation approach within a single partial wave
approximation. An energy and magnetic field dependent free space phase shift is
adopted in the current theoretical framework. For both $s$- and $p$-wave
interaction, the least bound state in the waveguide dissociates into the
continuum at the resonant magnetic field where the effective one-dimensional
scattering length $a_{\rm 1D}$ diverges. Consequently, the association of atoms
into molecules in the waveguide occurs when the magnetic field is swept
adiabatically across the pole of $a_{\rm 1D}$. In the vicinity of broad
$s$-wave resonances, the resonant magnetic field is nearly independent on the
transverse confining frequency $\omega_{\perp}$ of the waveguide. Close to
$p$-wave and narrow $s$-wave resonances, the resonant magnetic field changes as
$\omega_{\perp}$ varies.",1603.02616v1
2016-03-11,Separating hyperfine from spin-orbit interactions in organic semiconductors by multi-octave magnetic resonance using coplanar waveguide microresonators,"Separating the influence of hyperfine from spin-orbit interactions in
spin-dependent carrier recombination and dissociation processes necessitates
magnetic resonance spectroscopy over a wide range of frequencies. We have
designed compact and versatile coplanar waveguide resonators for
continuous-wave electrically detected magnetic resonance, and tested these on
organic light-emitting diodes. By exploiting both the fundamental and
higher-harmonic modes of the resonators we cover almost five octaves in
resonance frequency within a single setup. The measurements with a common
pi-conjugated polymer as the active material reveal small but non-negligible
effects of spin-orbit interactions, which give rise to a broadening of the
magnetic resonance spectrum with increasing frequency.",1603.03807v1
2016-03-15,Entangling distant resonant exchange qubits via circuit quantum electrodynamics,"We investigate a hybrid quantum system consisting of spatially separated
resonant exchange qubits, defined in three-electron semiconductor triple
quantum dots, that are coupled via a superconducting transmission line
resonator. Drawing on methods from circuit quantum electrodynamics and
Hartmann-Hahn double resonance techniques, we analyze three specific approaches
for implementing resonator-mediated two-qubit entangling gates in both
dispersive and resonant regimes of interaction. We calculate entangling gate
fidelities as well as the rate of relaxation via phonons for resonant exchange
qubits in silicon triple dots and show that such an implementation is
particularly well-suited to achieving the strong coupling regime. Our approach
combines the favorable coherence properties of encoded spin qubits in silicon
with the rapid and robust long-range entanglement provided by circuit QED
systems.",1603.04829v1
2016-04-16,Active Cancellation of Acoustical Resonances with an FPGA FIR Filter,"We present a novel approach to enhancing the bandwidth of a
feedback-controlled mechanical system by digitally canceling acoustical
resonances (poles) and anti-resonances (zeros) in the open-loop response via an
FPGA FIR filter. By performing a real-time convolution of the feedback error
signal with an inverse filter, we can suppress arbitrarily many poles and zeros
below 100 kHz, each with a linewidth down to 10 Hz. We demonstrate the efficacy
of this technique by canceling the ten largest mechanical resonances and
anti-resonances of a high-finesse optical resonator, thereby enhancing the
unity gain frequency by more than an order of magnitude. This approach is
applicable to a broad array of stabilization problems including optical
resonators, external cavity diode lasers, and scanning tunneling microscopes,
and points the way to applying modern optimal control techniques to intricate
linear acoustical systems.es to intricate linear acoustical systems.",1604.04668v1
2016-06-30,On spurious solutions in finite element approximations of resonances in open systems,"In this paper, we discuss problems arising when computing resonances with a
finite element method. In the pre-asymptotic regime, we detect for the one
dimensional case, spurious solutions in finite element computations of
resonances when the computational domain is truncated with a perfectly matched
layer (PML) as well as with a Dirichlet-to-Neumann map (DtN). The new test is
based on the Lippmann-Schwinger equation and we use computations of the
pseudospectrum to show that this is a suitable choice. Numerical simulations
indicate that the presented test can distinguish between spurious eigenvalues
and true eigenvalues also in difficult cases. Keywords: scattering resonances,
Lippmann-Schwinger equation, nonlinear eigenvalue problems, acoustic resonator,
dielectric resonator, Bragg resonator",1606.09635v2
2016-07-07,Resonance decay effect on conserved number fluctuations in a hadron resonance gas model,"We study the effect of charged secondaries coming from resonance decay on the
net-baryon, net-charge and net-strangeness fluctuations in high energy
heavy-ion collisions within the hadron resonance gas (HRG) model. We emphasize
the importance of including weak decays along with other resonance decays in
the HRG, while comparing with the experimental observables. The effect of
kinematic cuts on resonances and primordial particles on the conserved number
fluctuations are also studied. The HRG model calculations with the inclusion of
resonance decays and kinematical cuts are compared with the recent experimental
data from STAR and PHENIX experiments. We find a good agreement between our
model calculations and the experimental measurements for both net-proton and
net-charge distributions.",1607.01875v1
2016-07-07,Secular resonances with Ceres and Vesta,"In this work we explore dynamical perturbations induced by the massive
asteroids Ceres and Vesta on main-belt asteroids through secular resonances.
First we determine the location of the linear secular resonances with Ceres and
Vesta in the main belt, using a purely numerical technique. Then we use a set
of numerical simulations of fictitious asteroids to investigate the importance
of these secular resonances in the orbital evolution of main-belt asteroids. We
found, evaluating the magnitude of the perturbations in the proper elements of
the test particles, that in some cases the strength of these secular resonances
is comparable to that of known non-linear secular resonances with the giant
planets. Finally we explore the asteroid families that are crossed by the
secular resonances we studied, and identified several cases where the latter
seem to play an important role in their post-impact evolution.",1607.02035v1
2016-07-15,Evaluation of toroidal torque by non-resonant magnetic perturbations in tokamaks for resonant transport regimes using a Hamiltonian approach,"Toroidal torque generated by neoclassical viscosity caused by external
non-resonant, non-axisymmetric perturbations has a significant influence on
toroidal plasma rotation in tokamaks. In this article, a derivation for the
expressions of toroidal torque and radial transport in resonant regimes is
provided within quasilinear theory in canonical action-angle variables. The
proposed approach treats all low-collisional quasilinear resonant NTV regimes
including superbanana plateau and drift-orbit resonances in a unified way and
allows for magnetic drift in all regimes. It is valid for perturbations on
toroidally symmetric flux surfaces of the unperturbed equilibrium without
specific assumptions on geometry or aspect ratio. The resulting expressions are
shown to match existing analytical results in the large aspect ratio limit.
Numerical results from the newly developed code NEO-RT are compared to
calculations by the quasilinear version of the code NEO-2 at low
collisionalities. The importance of the magnetic shear term in the magnetic
drift frequency and a significant effect of the magnetic drift on drift-orbit
resonances are demonstrated.",1607.04665v1
2016-09-22,Transformation of the frequency-modulated continuous-wave field into a train of short pulses by resonant filters,"The resonant filtering method transforming frequency modulated radiation
field into a train of short pulses is proposed to apply in optical domain.
Effective frequency modulation can be achieved by electro-optic modulator or by
resonant frequency modulation of the filter with a narrow absorption line. Due
to frequency modulation narrow-spectrum CW radiation field is seen by the
resonant filter as a comb of equidistant spectral components separated by the
modulation frequency. Tuning narrow-bandwidth filter in resonance with $n$-th
spectral component of the comb transforms the radiation field into bunches of
pulses with $n$ pulses in each bunch. The transformation is explained by the
interference of the coherently scattered resonant component of the field with
the whole comb. Constructive interference results in formation of pulses, while
destructive interference is seen as dark windows between pulses. It is found
that the optimal thickness of the resonant filter is several orders of
magnitude smaller than the necessary thickness of the dispersive filters used
before in optical domain to produce short pulses from the frequency modulated
field.",1609.06872v1
2017-02-07,Dispersive optical detection of magnetic Feshbach resonances in ultracold gases,"Magnetically tunable Feshbach resonances in ultracold atomic systems are
chiefly identified and characterized through time consuming atom loss
spectroscopy. We describe an off-resonant dispersive optical probing technique
to rapidly locate Feshbach resonances and demonstrate the method by locating
four resonances of $^{87}$Rb, between the $|\rm{F} = 1, \rm{m_F}=1 \rangle$ and
$|\rm{F} = 2, \rm{m_F}=0 \rangle$ states. Despite the loss features being
$\lesssim0.1$ G wide, we require only 21 experimental runs to explore a
magnetic field range >18 G, where $1~\rm{G}=10^{-4}$ T. The resonances consist
of two known s-wave features in the vicinity of 9 G and 18 G and two previously
unobserved p-wave features near 5 G and 10 G. We further utilize the dispersive
approach to directly characterize the two-body loss dynamics for each Feshbach
resonance.",1702.02216v4
2017-02-20,Resonant Scattering Characteristics of Homogeneous Dielectric Sphere,"In the present article the classical problem of electromagnetic scattering by
a single homogeneous sphere is revisited. Main focus is the study of the
scattering behavior as a function of the material contrast and the size
parameters for all electric and magnetic resonances of a dielectric sphere.
Specifically, the Pad\'e approximants are introduced and utilized as an
alternative system expansion of the Mie coefficients. Low order Pad\'e
approximants can give compact and physically insightful expressions for the
scattering system and the enabled dynamic mechanisms. Higher order approximants
are used for predicting accurately the resonant pole spectrum. These results
are summarized into general pole formulae, covering up to fifth order magnetic
and forth order electric resonances of a small dielectric sphere. Additionally,
the connection between the radiative damping process and the resonant linewidth
is investigated. The results obtained reveal the fundamental connection of the
radiative damping mechanism with the maximum width occurring for each
resonance. Finally, the suggested system ansatz is used for studying the
resonant absorption maximum through a circuit-inspired perspective.",1702.05883v1
2017-03-06,Inverse resonance problems for the Schroedinger operator on the real line with mixed given data,"In this work, we study inverse resonance problems for the Schr\""odinger
operator on the real line with the potential supported in $[0,1]$. In general,
all eigenvalues and resonances can not uniquely determine the potential. (i) It
is shown that if the potential is known a priori on $[0,1/2]$, then the unique
recovery of the potential on the whole interval from all eigenvalues and
resonances is valid. (ii) If the potential is known a priori on $[0,a]$, then
for the case $a>1/2$, infinitely many eigenvalues and resonances can be missing
for the unique determination of the potential, and for the case $a<1/2$, all
eigenvalues and resonances plus a part of so-called sign-set can uniquely
determine the potential. (iii) It is also shown that all eigenvalues and
resonances, together with a set of logarithmic derivative values of
eigenfunctions and wave-functions at $1/2$, can uniquely determine the
potential.",1703.01708v2
2017-03-22,The non-ordinary Regge behavior of the K*0(800) or Kappa-meson versus the ordinary K*0(1430),"The Regge trajectory of an elastic resonance can be calculated from
dispersion theory, instead of fitted phenomenologically, using only its pole
parameters as input. This also provides a correct treatment of resonance widths
in Regge trajectories, essential for very wide resonances. In this work we
first calculate the K*0(1430) Regge trajectory, finding the ordinary almost
real and linear behavior, typical of quark-antiquark resonances. In contrast,
for the K*0(800) meson, the resulting Regge trajectory is non-linear and has a
much smaller slope than ordinary resonances, being remarkably similar to that
of the f0(500) or sigma meson. The slope of these unusual Regge trajectories
seems to scale with the meson masses rather than with scales typical of quark
degrees of freedom. We also calculate the range of the interaction responsible
for the formation of these resonances. Our results strongly support a
non-ordinary, predominantly meson-meson-like, interpretation for the lightest
strange and non-strange resonances.",1703.07661v2
2018-01-26,Boundarylike behaviors of the resonance interatomic energy in a cosmic string spacetime,"By generalizing the formalism proposed by Dalibard, Dupont-Roc and Cohen
Tannoudji, we study the resonance interatomic energy of two identical atoms
coupled to quantum massless scalar fields in a symmetric /antisymmetric
entangled state in the Minkowski and cosmic string spacetimes. We find that in
both spacetimes, the resonance interatomic energy has nothing to do with the
field fluctuations but is attributed to the radiation reaction of the atoms
only. We then concretely calculate the resonance interatomic energy of two
static atoms near a perfectly reflecting boundary in the Minkowski spacetime
and near an infinite and straight cosmic string respectively. We show that the
resonance interatomic energy in both cases can be enhanced or suppressed and
even nullified as compared with that in an unbounded Minkowski spacetime,
because of the presence of the boundary in the Minkowski spacetime or the
nontrivial spacetime topological structure of the cosmic string. Besides, we
also discover that the resonance interatomic energy in the cosmic string
spacetime exhibits some peculiar properties, making it in principle possible to
sense different cosmic string spacetimes via the resonance interatomic energy.",1802.01699v2
2018-02-11,Floquet spectroscopy of a strongly driven quantum dot charge qubit with a microwave resonator,"We experimentally investigate a strongly driven GaAs double quantum dot
charge qubit weakly coupled to a superconducting microwave resonator. The
Floquet states emerging from strong driving are probed by tracing the qubit -
resonator resonance condition. This way we probe the resonance of a qubit that
is driven in an adiabatic, a non-adiabatic, or an intermediate rate showing
distinct quantum features of multi-photon processes and
Landau-Zener-St\""uckelberg interference pattern. Our resonant detection scheme
enables the investigation of novel features when the drive frequency is
comparable to the resonator frequency. Models based on adiabatic approximation,
rotating wave approximation, and Floquet theory explain our experimental
observations.",1802.03810v1
2018-02-20,Dynamo induced by time-periodic force,"To understand the dynamo driven by time-dependent flow, e.g. turbulence, we
investigate numerically the dynamo induced by time-periodic force in rotating
magnetohydrodynamic flow and focus on the effect of force frequency on the
dynamo action. It is found that the dynamo action depends on the force
frequency. When the force frequency is near resonance the force can drive
dynamo but when it is far away from resonance dynamo fails. In the frequency
range near resonance to support dynamo, the force frequency at resonance
induces a weak magnetic field and magnetic energy increases as the force
frequency deviates from the resonant frequency. This is opposite to the
intuition that a strong flow at resonance will induce a strong field. It is
because magnetic field nonlinearly couples with fluid flow in the
self-sustained dynamo and changes the resonance of driving force and inertial
wave.",1802.08284v2
2018-11-24,Resonant Trapping of the Moving Groups G18-39 and G21-22 in the Galactic Halo,"The 3D Galactic orbits of stars in the two groups G18-39 and G21-22
pertaining to the Galactic halo have been computed in a Galactic potential
including a Galactic bar. The orbits have been related with the orbital
structure of resonant orbits on the Galactic plane created by the bar
component. We find that the majority of stars in both groups are trapped mainly
by two resonant families already studied in a previous analysis. We show that
the observed U--V velocity field of the stars in both groups can be naturally
explained as a result of their trapping by these two resonant families, taking
the angular rotation speed of the bar approximately in the interval 45--60
$\mathrm{km\,s^{-1}\,kpc^{-1}}$. This analysis may help to understand the
identification of other known star groups as the possible result of the
interactions produced by resonances on stars close to resonant families. For
the two groups G18-39 and G21-22 we conclude that the majority of their stars
are members of the supergroups of stars in the Galaxy trapped by two resonant
families generated by the Galactic bar.",1811.09827v1
2019-04-30,Tidal resonance in extreme mass-ratio inspirals,"We describe a new class of resonances for extreme mass-ratio inspirals
(EMRIs): tidal resonances, induced by the tidal field of nearby stars or
stellar-mass black holes. A tidal resonance can be viewed as a general
relativistic extension of the Kozai-Lidov resonances in Newtonian systems, and
is distinct from the transient resonance already known for EMRI systems. Tidal
resonances will generically occur for EMRIs. By probing their influence on the
phase of an EMRI waveform, we can learn about the tidal environmental of the
EMRI system, albeit at the cost of a more complicated waveform model.
Observations by LISA of EMRI systems therefore have the potential to provide
information about the distribution of stellar-mass objects near their host
galactic-center black holes.",1905.00030v2
2020-07-03,Rigorous Quantum Formulation of Parity-Time Symmetric Coupled Resonators,"Rigorous quantum formulation of the Parity-Time (PT) symmetry phenomenon in
the RF/microwave regime for a coupled coil resonators with lump elements has
been presented. The coil resonator is described by the lump-element model that
consists of an inductor (L), a resistor (R) and a capacitor (C). Rigorous
quantum Hamiltonian for the coupled LRC coil resonators system has been derived
through twice basis transforms of the original basis. The first basis transform
rotates the original basis such that off-diagonal terms of the governing matrix
of the equation system of the coupled coil resonators reduces to constants.
Then a second basis transform obtains the quantum Hamiltonian, including the
diagonal effective complex frequencies and the off-diagonal coupling terms,
together with the transformed basis. With the obtain quantum Hamiltonian, the
eigenvalues and eigenvectors of the coupled coil resonators can be obtained as
usual as the quantum Hamiltonian. Finally, numerical simulation verifies the
correctness of the theory. The quantum formulation of the coupled coil
resonators can provide better guideline to design a better PT-symmetric system.",2007.01462v1
2020-07-29,Spatial Fano resonance of a dielectric microsphere impinged by a Bessel beam,"General concept of Fano resonance is considered so that to show the
possibility of this resonance in space. Using a recently found solution for a
Bessel wave beam impinging a dielectric sphere, we analyze the electromagnetic
fields near a microsphere with different optical size and permittivity values.
We theoretically reveal a spatial Fano resonance when a resonant mode of the
sphere interferes with {an amount of } non-resonant modes. This resonance
results in a giant jump of the electric field behind the sphere impinged by the
first-order Bessel beam. The local minimum of the electromagnetic field turns
out to be noticeably distanced from the rear edge of the microsphere. However,
this is a near-field effect and we prove it. We also show that this effect can
be utilized for engineering a submicron optical trap with unusual and useful
properties.",2007.14867v2
2020-07-29,Resonant bending of silicon nanowires by light,"Coupling of two dielectric wires with rectangular cross-section gives rise to
bonding and anti-bonding resonances. The latter is featured by extremal
narrowing of the resonant width for variation of the aspect ratio of the
cross-section and distance between wires when the morphology of the
anti-bonding resonant mode approaches to the morphology of the Mie resonant
mode of effective circular wire with high azimuthal index. Then plane wave
resonant to this anti-bonding resonance gives rise to unprecedent enhancement
of the optical forces up to several nano Newtons per micron length of wires.
The forces oscillate with angle of incidence of plane wave but always try to
repel the wires. If the wires are fixed at the ends the optical forces result
in elastic deflection of wires of order $100 nm$ for wires's length $50\mu m$
and the light power $1.5mW/\mu m^2$.",2007.15434v1
2010-05-06,Fermi-edge singularity in the vicinity of the resonant scattering condition,"Fermi-edge absorption theory predicting the spectrum, A(\omega)\propto
\omega^{-2\delta_0/\pi+\delta^2_0/\pi^2}, relies on the assumption that
scattering phase, \delta_0, is frequency-independent. Dependence of \delta_0 on
\omega becomes crucial near the resonant condition, where the phase changes
abruptly by \pi. In this limit, due to finite time spent by electron on a
resonant level, the scattering is dynamic. We incorporate this time delay into
the theory, solve the Dyson equation with a modified kernel and find that, near
the resonance, A(\omega) behaves as \omega^{-3/4} |\ln \omega|. Resonant
scattering off the core hole takes place in 1D and 2D in the presence of an
empty subband above the Fermi level; then attraction to hole splits off a
resonant level from the bottom of the empty subband. Fermi-edge absorption in
the regime when resonant level transforms into a Kondo peak is discussed.",1005.0873v1
2010-05-16,Resonance spectrum for one-dimensional layered media,"We consider the ""weighted"" operator $P_k=-\partial_x a(x)\partial_x$ on the
line with a step-like coefficient which appears when propagation of waves
thorough a finite slab of a periodic medium is studied. The medium is
transparent at certain resonant frequencies which are related to the complex
resonance spectrum of $P_k.$ If the coefficient is periodic on a finite
interval (locally periodic) with $k$ identical cells then the resonance
spectrum of $P_k$ has band structure. In the present paper we study a
transition to semi-infinite medium by taking the limit $k\to \infty.$
  The bands of resonances in the complex lower half plane are localized below
the band spectrum of the corresponding periodic problem ($k=\infty$) with $k-1$
or $k$ resonances in each band. We prove that as $k\to \infty$ the resonance
spectrum converges to the real axis.",1005.2743v1
2014-03-13,Fano-Feshbach resonances in two-channel scattering around exceptional points,"It is well known that in open quantum systems resonances can coalesce at an
exceptional point, where both the energies {\em and} the wave functions
coincide. In contrast to the usual behaviour of the scattering amplitude at one
resonance, the coalescence of two resonances invokes a pole of second order in
the Green's function, in addition to the usual first order pole. We show that
the interference due to the two pole terms of different order gives rise to
patterns in the scattering cross section which closely resemble Fano-Feshbach
resonances. We demonstrate this by extending previous work on the analogy of
Fano-Feshbach resonances to classical resonances in a system of two driven
coupled damped harmonic oscillators.",1403.3187v1
2014-03-17,Spin resonance without spin splitting,"We predict that a single-level quantum dot without discernible splitting of
its spin states develops a spin-precession resonance in charge transport when
embedded into a spin valve. The resonance occurs in the generic situation of
Coulomb blockaded transport with ferromagnetic leads whose polarizations
deviate from perfect antiparallel alignment. The resonance appears when
electrically tuning the interaction-induced exchange field perpendicular to one
of the polarizations -- a simple condition relying on vectors in contrast to
usual resonance conditions associated with energy splittings. The spin
resonance can be detected by stationary dI/dV spectroscopy and by oscillations
in the time-averaged current using a gate-pulsing scheme. The generic
noncollinearity of the ferromagnets and junction asymmetry allow for an
all-electric determination of the spin-injection asymmetry, the anisotropy of
spin relaxation, and the magnitude of the exchange field. We also investigate
the impact of a nearby superconductor on the resonance position. Our simplistic
model turns out to be generic for a broad class of coherent few-level quantum
systems.",1403.4002v2
2014-03-18,Optomechanical-like coupling between superconducting resonators,"We propose and analyze a circuit that implements a nonlinear coupling between
two superconducting microwave resonators. The resonators are coupled through a
superconducting quantum interference device (SQUID) that terminates one of the
resonators. This produces a nonlinear interaction on the standard
optomechanical form, where the quadrature of one resonator couples to the
photon number of the other resonator. The circuit therefore allows for
all-electrical realizations of analogs to optomechanical systems, with coupling
that can be both strong and tunable. We estimate the coupling strengths that
should be attainable with the proposed device, and we find that the device is a
promising candidate for realizing the single-photon strong-coupling regime. As
a potential application, we discuss implementations of networks of
nonlinearly-coupled microwave resonators, which could be used in
microwave-photon based quantum simulation.",1403.4341v1
2014-03-27,Observation of Efimov Resonances in a Mixture with Extreme Mass Imbalance,"We observe two consecutive heteronuclear Efimov resonances in an ultracold
Li-Cs mixture by measuring three-body loss coefficients as a function of
magnetic field near a Feshbach resonance. The first resonance is detected at a
scattering length of $a_-^{(1)}=-320(10)~a_0$ corresponding to $\sim 7 $ ($\sim
3$) times the Li-Cs (Cs-Cs) van der Waals range. The second resonance appears
at $5.8(1.0) a_-^{(1)}$ close to the unitarity-limited regime at the sample
temperature of 450 nK. Indication of a third resonance is found in the atom
loss spectra. The scaling of the resonance positions is close to the universal
scaling value of 4.9 predicted for zero temperature. Deviations from
universality might be caused by finite-range and temperature effects, as well
as magnetic field dependent Cs-Cs interactions.",1403.7246v2
2016-11-27,Real-time measurement of nanotube resonator fluctuations in an electron microscope,"Mechanical resonators based on low-dimensional materials provide a unique
platform for exploring a broad range of physical phenomena. The mechanical
vibrational states are indeed extremely sensitive to charges, spins, photons,
and adsorbed masses. However, the roadblock is often the readout of the
resonator, since the detection of the vibrational states becomes increasingly
difficult for smaller resonators. Here, we report an unprecedentedly sensitive
method to detect nanotube resonators with effective masses in the 10^-20 kg
range. We use the beam of an electron microscope to resolve the mechanical
fluctuations of a nanotube in real-time for the first time. We obtain full
access to the thermally-driven Brownian motion of the resonator, both in space
and time domains. Our results establish the viability of carbon nanotube
resonator technology at room temperature and pave the way towards the
observation of novel thermodynamics regimes and quantum effects in
nano-mechanics.",1611.08873v1
2017-01-24,The Structure of the Distant Kuiper Belt in a Nice Model Scenario,"This work explores the orbital distribution of minor bodies in the outer
Solar System emplaced as a result of a Nice model migration from the
simulations of Brasser & Morbidelli (2013). This planetary migration scatters a
planetesimal disk from between 29-34 AU and emplaces a population of objects
into the Kuiper belt region. From the 2:1 Neptune resonance and outward, the
test particles analyzed populate the outer resonances with orbital
distributions consistent with trans-Neptunian object (TNO) detections in
semi-major axis, inclination, and eccentricity, while capture into the closest
resonances is too efficient. The relative populations of the simulated
scattering objects and resonant objects in the 3:1 and 4:1 resonances are also
consistent with observed populations based on debiased TNO surveys, but the 5:1
resonance is severely underpopulated compared to population estimates from
survey results. Scattering emplacement results in the expected orbital
distribution for the majority of the TNO populations, however the origin of the
large observed population in the 5:1 resonance remains unexplained.",1701.07041v1
2018-05-05,Signatures of few-body resonances in finite volume,"We study systems of bosons and fermions in finite periodic boxes and show how
the existence and properties of few-body resonances can be extracted from
studying the volume dependence of the calculated energy spectra. Using a
plane-wave-based discrete variable representation to conveniently implement
periodic boundary conditions, we establish that avoided level crossings occur
in the spectra of up to four particles and can be linked to the existence of
multi-body resonances. To benchmark our method we use two-body calculations,
where resonance properties can be determined with other methods, as well as a
three-boson model interaction known to generate a three-boson resonance state.
Finding good agreement for these cases, we then predict three-body and
four-body resonances for models using a shifted Gaussian potential. Our results
establish few-body finite-volume calculations as a new tool to study few-body
resonances. In particular, the approach can be used to study few-neutron
systems, where such states have been conjectured to exist.",1805.02029v2
2018-05-22,Resonances in small scatterers with impedance boundary,"With analytical (generalized Mie scattering) and numerical
(integral-equation-based) considerations we show the existence of strong
resonances in the scattering response of small spheres with lossless impedance
boundary. With increasing size, these multipolar resonances are damped and
shifted with respect to the magnitude of the surface impedance. The
electric-type resonances are inductive and magnetic ones capacitive.
Interestingly, these subwavelength resonances resemble plasmonic resonances in
small negative-permittivity scatterers and dielectric resonances in small
high-permittivity scatterers. The fundamental dipolar mode is also analyzed
from the point of view of surface currents and the effect of the change of the
shape into a non-spherical geometry.",1805.09159v1
2018-05-25,Model-based resonance tracking of linear systems,"The present paper develops recursive algorithms to track shifts in the
resonance frequency of linear systems in real time. To date, automatic
resonance tracking has been limited to non-model-based approaches, which rely
solely on the phase difference between a specific input and output of the
system. Instead, we propose a transformation of the system into a
complex-valued representation, which allows us to abstract the resonance shifts
as an exogenous disturbance acting on the excitation frequency, perturbing the
excitation frequency from the natural frequency of the plant. We then discuss
the resonance tracking task in two parts: recursively identifying the frequency
disturbance and incorporating an update of the excitation frequency in the
algorithm. The complex representation of the system simplifies the design of
resonance tracking algorithms due to the applicability of well-established
techniques. We discuss the stability of the proposed scheme, even in cases that
seriously challenge current phase-based approaches, such as nonmonotonic phase
differences and multiple-input multiple-output systems. Numerical simulations
further demonstrate the performance of the proposed resonance tracking scheme.",1805.10085v3
2012-01-11,Phase Transitions in Trajectories of a Superconducting Single-Electron Transistor Coupled to a Resonator,"Recent progress in the study of dynamical phase transitions has been made
with a large-deviation approach to study trajectories of stochastic jumps using
a thermodynamic formalism. We study this method applied to an open quantum
system consisting of a superconducting single-electron transistor, near the
Josephson quasiparticle resonance, coupled to a resonator. We find that the
dynamical behavior shown in rare trajectories can be rich even when the mean
dynamical activity is small and thus the formalism gives insights into the form
of fluctuations. The structure of the dynamical phase diagram found from the
quantum-jump trajectories of the resonator is studied and we see that sharp
transitions in the dynamical activity may be related to the appearance and
disappearance of bistabilities in the state of the resonator as system
parameters are changed. We also demonstrate that for a fast resonator, the
trajectories of quasiparticles are similar to the resonator trajectories.",1201.2442v2
2012-04-11,Resonant Repulsion of Kepler Planet Pairs,"Planetary systems discovered by the Kepler space telescope exhibit an
intriguing feature. While the period ratios of adjacent low-mass planets appear
largely random, there is a significant excess of pairs that lie just wide of
resonances and a deficit on the near side. We demonstrate that this feature
naturally arises when two near-resonant planets interact in the presence of
weak dissipation that damps eccentricities. The two planets repel each other as
orbital energy is lost to heat. This moves near-resonant pairs just beyond
resonance, by a distance that reflects the integrated dissipation they
experienced over their lifetimes. We find that the observed distances may be
explained by tides if tidal dissipation is unexpectedly efficient (tidal
quality factor ~10). Once the effect of resonant repulsion is accounted for,
the initial orbits of these low mass planets show little preference for
resonances. This could constrain their origin.",1204.2555v3
2012-04-12,Dissipative Divergence of Resonant Orbits,"A considerable fraction of multi-planet systems discovered by the
observational surveys of extrasolar planets reside in mild proximity to
first-order mean motion resonances. However, the relative remoteness of such
systems from nominal resonant period ratios (e.g. 2:1, 3:2, 4:3) has been
interpreted as evidence for lack of resonant interactions. Here we show that a
slow divergence away from exact commensurability is a natural outcome of
dissipative evolution and demonstrate that libration of critical angles can be
maintained tens of percent away from nominal resonance. We construct an
analytical theory for the long-term dynamical evolution of dissipated resonant
planetary pairs and confirm our calculations numerically. Collectively, our
results suggest that a significant fraction of the near-commensurate extrasolar
planets are in fact resonant and have undergone significant dissipative
evolution.",1204.2791v2
2013-09-25,Capture into resonance and escape from it in a forced nonlinear pendulum,"We study dynamics of a nonlinear pendulum under a periodic force with small
amplitude and slowly decreasing frequency. It is well known that when the
frequency of the external force passes through the value of the frequency of
the unperturbed pendulum's oscillations, the pendulum can be captured into the
resonance. The captured pendulum oscillates in such a way that the resonance is
preserved, and the amplitude of the oscillations accordingly grows. We consider
this problem in the frames of a standard Hamiltonian approach to resonant
phenomena in slow-fast Hamiltonian systems developed earlier, and evaluate the
probability of capture into the resonance. If the system passes the resonance
at small enough initial amplitudes of the pendulum, the capture occurs with
necessity (so-called autoresonance). In general, the probability of capture
varies between one and zero, depending on the initial amplitude. We demonstrate
that a pendulum captured at small values of its amplitude escapes from the
resonance in the domain of oscillations close to the separatrix of the
pendulum, and evaluate the amplitude of the oscillations at the escape.",1309.6501v1
2014-05-11,A mathematical theory of super-resolution by using a system of sub-wavelength Helmholtz resonators,"A rigorous mathematical theory is developed to explain the super-resolution
phenomenon observed in the experiment by F.Lemoult, M.Fink and G.Lerosey
(Acoustic resonators for far-field control of sound on a subwavelength scale,
Phys. Rev. Lett., 107 (2011)). A key ingredient is the calculation of the
resonances and the Green function in the half space with the presence of a
system of Helmholtz resonators in the quasi-stationary regime. By using
boundary integral equations and generalized Rouche's theorem, the existence and
the leading asymptotic of the resonances are rigorously derived. The integral
equation formulation also yields the leading order terms in the asymptotics of
the Green function. The methodology developed in the paper provides an elegant
and systematic way for calculating resonant frequencies for Helmholtz
resonators in assorted space settings as well as in various frequency regimes.
By using the asymptotics of the Green function, the analysis of the imaging
functional of the time-reversal wave fields becomes possible, which clearly
demonstrates the super-resolution property. The result provides the first
mathematical theory of super-resolution in the context of a deterministic
medium and sheds light to the mechanism of super-resolution and super-focusing
for waves in deterministic complex media.",1405.2513v1
2014-06-27,Ultrasensitive THz sensing with high-Q Fano resonances in metasurfaces,"High quality factor resonances are extremely promising for designing
ultra-sensitive refractive index label-free sensors since it allows intense
interaction between electromagnetic waves and the analyte material.
Metamaterial and plasmonic sensing has recently attracted a lot of attention
due to subwavelength confinement of electromagnetic fields in the resonant
structures. However, the excitation of high quality factor resonances in these
systems has been a challenge. We excite an order of magnitude higher quality
factor resonances in planar terahertz metamaterials that we exploit for
ultrasensitive sensing. The low-loss quadrupole and Fano resonances with
extremely narrow linewidths enable us to measure the minute spectral shift
caused due to the smallest change in the refractive index of the surrounding
media. We achieve sensitivity levels of 7.75 x 10^3 nm/ RIU with quadrupole and
5.7 x 10^4 nm/ RIU with the Fano resonances which could be further enhanced by
using thinner substrates. These findings would facilitate the design of
ultrasensitive real time chemical and biomolecular sensors in the fingerprint
region of the terahertz regime.",1406.7194v1
2016-05-05,Linear and nonlinear responses to harmonic force in rotating flow,"For understanding the dissipation in a rotating flow when resonance occurs,
we study the rotating flow driven by the harmonic force in a periodic box. Both
the linear and nonlinear regimes are studied. The various parameters such as
the force amplitude $a$, the force frequency $\omega$, the force wavenumber
$k$, and the Ekman number $E$ are investigated. In the linear regime, the
dissipation at the resonant frequency scales as $E^{-1}k^{-2}$, and it is much
stronger than the dissipation at the non-resonant frequencies on the large
scales and at the low Ekman numbers. In the nonlinear regime, at the resonant
frequency the effective dissipation (dissipation normalised with the square of
force amplitude) is lower than in the linear regime and it decreases with the
increasing force amplitude. This nonlinear suppression effect is significant
near the resonant frequency but negligible far away from the resonant
frequency. Opposite to the linear regime, in the nonlinear regime at the
resonant frequency the lower Ekman number leads to the lower dissipation
because of the stronger nonlinear effect. This work implies that the previous
linear calculations overestimated the tidal dissipation, which is important for
understanding the tides in stars and giant planets.",1605.01462v1
2016-05-07,Importance of resonance widths in low-energy scattering of weakly-bound light-mass nuclei,"What effect do particle-emitting resonances have on the scattering cross
section? What physical considerations are necessary when modelling these
resonances? These questions are important when theoretically describing
scattering experiments with radioactive ion beams which investigate the
frontiers of the table of nuclides, far from stability. Herein, a novel method
is developed that describes resonant nuclear scattering from which centroids
and widths in the compound nucleus are obtained when one of the interacting
bodies has particle unstable resonances. The method gives cross sections
without unphysical behavior that is found if simple Lorentzian forms are used
to describe resonant target states. The resultant cross sections differ
significantly from those obtained when the states in the coupled channel
calculations are taken to have zero width, and compound-system resonances are
better matched to observed values.",1605.02183v1
2016-05-29,Enhanced light-vapor interactions and all optical switching in a chip scale micro-ring resonator coupled with atomic vapor,"The coupling of atomic and photonic resonances serves as an important tool
for enhancing light-matter interactions and enables the observation of
multitude of fascinating and fundamental phenomena. Here, by exploiting the
platform of atomic-cladding wave guides, we experimentally demonstrate the
resonant coupling of rubidium vapor and an atomic cladding micro ring
resonator. Specifically, we observed cavity-atom coupling in the form of Fano
resonances having a distinct dependency on the relative frequency detuning
between the photonic and the atomic resonances. Moreover, we were able to
significantly enhance the efficiency of all optical switching in the V-type
pump-probe scheme. The coupled system of micro-ring resonator and atomic vapor
is a promising building block for a variety of light vapor experiments, as it
offers a very small footprint, high degree of integration and extremely strong
confinement of light and vapor. As such it may be used for important
applications, such as all optical switching, dispersion engineering (e.g. slow
and fast light) and metrology, as well as for the observation of important
effects such as strong coupling, Purcell enhancement and bistability.",1605.09008v1
2016-05-30,Sign-Reversal Coupling in Coupled-Resonator Optical Waveguide,"Coupled-resonator optical waveguides (CROWs), which play a significant role
in modern photonics, achieve waveguiding through near-field coupling between
tightly localized resonators. The coupling factor, a critical parameter in CROW
theory, determines the coupling strength between two resonators and the
waveguiding dispersion of a CROW. However, the original CROW theory proposed by
Yariv et al. only demonstrated one value of coupling factor for a multipole
resonance mode. Here, by imaging the tight-binding Bloch waves on a CROW
consisting of designer-surface-plasmon resonators in the microwave regime, we
demonstrate that the coupling factor in the CROW theory can reverse its sign
for a multipole resonance mode. This determines two different waveguiding
dispersion curves in the same frequency range, experimentally confirmed by
matching Bloch wavevectors and frequencies in the CROW. Our study supplements
and extends the original CROW theory, and may find novel use in functional
photonic systems.",1605.09163v1
2016-07-29,Shape-resonant superconductivity in nanofilms: from weak to strong coupling,"Ultrathin superconductors of different materials are becoming a powerful
platform to find mechanisms for enhancement of superconductivity, exploiting
shape resonances in different superconducting properties. Here we evaluate the
superconducting gap and its spatial profile, the multiple gap components, and
the chemical potential, of generic superconducting nanofilms, considering the
pairing attraction and its energy scale as tunable parameters, from weak to
strong coupling, at fixed electron density. Superconducting properties are
evaluated at mean field level as a function of the thickness of the nanofilm,
in order to characterize the shape resonances in the superconducting gap. We
find that the most pronounced shape resonances are generated for weakly coupled
superconductors, while approaching the strong coupling regime the shape
resonances are rounded by a mixing of the subbands due to the large energy gaps
extending over large energy scales. Finally, we find that the spatial profile,
transverse to the nanofilm, of the superconducting gap acquires a flat behavior
in the shape resonance region, indicating that a robust and uniform multigap
superconducting state can arise at resonance.",1608.01272v1
2016-08-03,Ultra-Low Dissipation Superfluid Micromechanical Resonator,"Micro and nanomechanical resonators with ultra-low dissipation have great
potential as useful quantum resources. The superfluid micromechanical
resonators presented here possess several advantageous characteristics:
straightforward thermalization, dissipationless flow, and in situ tunability.
We identify and quantitatively model the various dissipation mechanisms in two
resonators, one fabricated from borosilicate glass and one from single crystal
quartz. As the resonators are cryogenically cooled into the superfluid state,
the damping from thermal effects and from the normal fluid component are
strongly suppressed. At our lowest temperatures, damping is limited solely by
internal dissipation in the substrate materials, and reach quality factors up
to 913,000 at 13 mK. By lifting this limitation through substrate material
choice and resonator design, modelling suggests that the resonators should
reach quality factors as high as 10$^8$ at 100 mK, putting this architecture in
an ideal position to harness mechanical quantum effects.",1608.01380v1
2016-12-20,Effects of volume corrections and resonance decays on cumulants of net-charge distributions in a Monte Carlo hadron resonance gas model,"The effects of volume corrections and resonance decays (the resulting
correlations between positive charges and negative charges) on cumulants of
net-proton distributions and net-charge distributions are investigated by using
a Monte Carlo hadron resonance gas ({\tt MCHRG}) model. The required volume
distributions are generated by a Monte Carlo Glauber ({\tt MC-Glb}) model.
Except the variances of net-charge distributions, the {\tt MCHRG} model with
more realistic simulations of volume corrections, resonance decays and
acceptance cuts can reasonably explain the data of cumulants of net-proton
distributions and net-charge distributions reported by the STAR collaboration.
The {\tt MCHRG} calculations indicate that both the volume corrections and
resonance decays make the cumulant products of net-charge distributions deviate
from the Skellam expectations: the deviations of $S\sigma$ and
$\kappa\sigma^{2}$ are dominated by the former effect while the deviations of
$\omega$ are dominated by the latter one.",1612.06485v1
2017-06-29,Analytical model of multi-planetary resonant chains and constraints on migration scenarios,"Resonant chains are groups of planets for which each pair is in resonance,
with an orbital period ratio locked at a rational value (2/1, 3/2, etc.). Such
chains naturally form as a result of convergent migration of the planets in the
proto-planetary disk. In this article, I present an analytical model of
resonant chains of any number of planets. Using this model, I show that a
system captured in a resonant chain can librate around several possible
equilibrium configurations. The probability of capture around each equilibrium
depends on how the chain formed, and especially on the order in which the
planets have been captured in the chain. Therefore, for an observed resonant
chain, knowing around which equilibrium the chain is librating allows for
constraints to be put on the formation and migration scenario of the system. I
apply this reasoning to the four planets orbiting Kepler-223 in a 3:4:6:8
resonant chain. I show that the system is observed around one of the six
equilibria predicted by the analytical model. Using N-body integrations, I show
that the most favorable scenario to reproduce the observed configuration is to
first capture the two intermediate planets, then the outermost, and finally the
innermost.",1706.09613v1
2017-07-05,Hybrid phase-space--Fock-space approach to evolution of a driven nonlinear resonator,"We analyze the quantum evolution of a weakly nonlinear resonator due to a
classical near-resonant drive and damping. The resonator nonlinearity leads to
squeezing and heating of the resonator state. Using a hybrid
phase-space--Fock-space representation for the resonator state within the
Gaussian approximation, we derive evolution equations for the four parameters
characterizing the Gaussian state. Numerical solution of these four ordinary
differential equations is much simpler and faster than simulation of the full
density matrix evolution, while providing good accuracy for the system analysis
during transients and in the steady state. We show that steady-state squeezing
of the resonator state is limited by 3 dB; however, this limit can be exceeded
during transients.",1707.01593v2
2017-07-18,Boosting the power factor with resonant states: a model study,"A particularly promising pathway to enhance the efficiency of thermoelectric
materials lies in the use of resonant states, as suggested by experimentalists
and theorists alike. In this paper, we go over the mechanisms used in the
literature to explain how resonant levels affect the thermoelectric properties,
and we suggest that the effects of hybridization are crucial yet
ill-understood. In order to get a good grasp of the physical picture and to
draw guidelines for thermoelectric enhancement, we use a tight-binding model
containing a conduction band hybridized with a flat band. We find that the
conductivity is suppressed in a wide energy range near the resonance, but that
the Seebeck coefficient can be boosted for strong enough hybridization, thus
allowing for a significant increase of the power factor. The Seebeck
coefficient can also display a sign change as the Fermi level crosses the
resonance. Our results suggest that in order to boost the power factor, the
hybridization strength must not be too low, the resonant level must not be too
close to the conduction (or valence) band edge, and the Fermi level must be
located around, but not inside, the resonant peak.",1707.05611v1
2017-07-28,A self-tuning optical resonator,"We demonstrate a nonlinear optical resonator that tunes itself onto resonance
with an input beam. In a monolithic Fabry-Perot cavity implemented in
rubidium-doped periodically-poled potassium titanyl phosphate, an
intensity-dependent refractive index produces line-pulling by multiple
free-spectral ranges (FSRs). In this condition, the cavity passively maintains
optical resonance in the face of FSR-scale excursions of the drive laser
frequency: when one resonant operating-point becomes unstable, the resonator
rapidly transitions to another resonant operating point. We demonstrate stable
second-harmonic generation with no active feedback to laser or cavity. The
self-tuning effect appears to be supported by a very strong, previously
unreported optical nonlinearity.",1707.09085v3
2017-10-17,Breaking mean-motion resonances during Type I planet migration,"We present two-dimensional hydrodynamical simulations of pairs of planets
migrating simultaneously in the Type I regime in a protoplanetary disc.
Convergent migration naturally leads to the trapping of these planets in
mean-motion resonances. Once in resonance the planets' eccentricity grows
rapidly, and disc-planet torques cause the planets to escape resonance on a
time-scale of a few hundred orbits. The effect is more pronounced in highly
viscous discs, but operates efficiently even in inviscid discs. We attribute
this resonance-breaking to overstable librations driven by moderate
eccentricity damping, but find that this mechanism operates differently in
hydrodynamic simulations than in previous analytic calculations. Planets
escaping resonance in this manner can potentially explain the observed paucity
of resonances in Kepler multi-transiting systems, and we suggest that
simultaneous disc-driven migration remains the most plausible means of
assembling tightly-packed planetary systems.",1710.06435v1
2017-12-07,Double-negative electromagnetic metamaterials due to chirality,"The aim of this paper is to provide a mathematical theory for understanding
the mechanism behind the double-negative refractive index phenomenon in chiral
materials. The design of double-negative metamaterials generally requires the
use of two different kinds of subwavelength resonators, which may limit the
applicability of double-negative metamaterials. Herein, we rely on media that
consist of only a single type of dielectric resonant element, and show how the
chirality of the background medium induces double-negative refractive index
metamaterial, which refracts waves negatively, hence acting as a superlens.
Using plasmonic dielectric particles, it is proved that both the effective
electric permittivity and the magnetic permeability can be negative near some
resonant frequencies. A justification of the approximation of a plasmonic
particle in a chiral medium by the sum of a resonant electric dipole and a
resonant magnetic dipole, is provided. Moreover, the set of resonant
frequencies is characterized. For an appropriate volume fraction of plasmonic
particles with certain conditions on their configuration, a double-negative
effective medium can be obtained when the frequency is near one of the resonant
frequencies.",1712.02863v1
2017-12-12,Tuning coupling between superconducting resonators with collective qubits,"By simultaneously coupling multiple two-level artificial atoms to two
superconducting resonators, we design a quantum switch that tunes the
resonator-resonator coupling strength from zero to a large value proportional
to the number of qubits. This process is implemented by engineering the qubits
into different subradiant states, where the microwave photons decay from
different qubits destructively interfere with each other such that the
resonator-resonator coupling strength keeps stable in an open environment.
Based on a three-step control scheme, we switch the coupling strength among
different values within nanoseconds without changing the transition frequency
of the qubits. We also apply the quantum switch to a network of superconducting
resonators, and demonstrate its potential applications in quantum simulation
and quantum information storage and processing.",1712.04357v2
2017-12-29,Flux-tunable heat sink for quantum electric circuits,"Superconducting microwave circuits show great potential for practical quantum
technological applications such as quantum information processing. However,
fast and on-demand initialization of the quantum degrees of freedom in these
devices remains a challenge. Here, we experimentally implement a tunable heat
sink that is potentially suitable for the initialization of superconducting
qubits. Our device consists of two coupled resonators. The first resonator has
a high quality factor and a fixed frequency whereas the second resonator is
designed to have a low quality factor and a tunable resonance frequency. We
engineer the low quality factor using an on-chip resistor and the frequency
tunability using a superconducting quantum interference device. When the two
resonators are in resonance, the photons in the high-quality resonator can be
efficiently dissipated. We show that the corresponding loaded quality factor
can be tuned from above $10^5$ down to a few thousand at 10 GHz in good
quantitative agreement with our theoretical model.",1712.10256v1
2018-01-09,Three-neutron resonance study using transition operators,"Existing bound-state type calculations of three-neutron resonances yield
contradicting results. A direct study of the three-neutron continuum using
rigorous scattering equations with realistic potentials and search for possible
resonances is aimed. Faddeev-type integral equations for three-neutron
transition operators are solved in the momentum-space partial-wave framework.
The evolution of resonances is studied by enhancing the strength of the
two-neutron interaction in partial waves with nonzero orbital momentum.
Calculated three-neutron transition operators exhibit resonant behavior for
sufficiently large enhancement factors; pole trajectories in the complex-energy
energy plane are extracted from their energy dependence. However, the resonant
behavior completely disappears for the physical interaction strength. There are
no physically observable three-neutron resonant states consistent with
presently accepted interaction models.",1801.02919v2
2018-09-05,NMR-like effect on Anisotropic Magnetic Moment of Surface Bound States in Topological Superfluid $^3$He-B,"We present experimental observation of a new phenomenon, that we interpret as
NMR-like effect on anisotropic magnetic moment of the surface Andreev bound
states in topological superfluid $^3$He-B at zero temperature limit. We show
that an anisotropic magnetic moment formed near the horizontal surface of a
mechanical resonator due to symmetry violation of the superfluid $^3$He-B order
parameter by the resonator's surface may lead to anomalous damping of the
resonator motion in magnetic field. In difference to classical NMR technique,
here NMR was excited using own harmonic motion of the mechanical resonator, and
nuclear magnetic resonance was detected as a maximum in damping when
resonator's angular frequency satisfied the Larmor resonance condition.",1809.01402v3
2018-09-19,High quality factor mechanical resonance in a silicon nanowire,"Resonance properties of nanomechanical resonators based on doubly clamped
silicon nanowires, fabricated from silicon-on-insulator and coated with a thin
layer of aluminum, were experimentally investigated. Resonance frequencies of
the fundamental mode were measured at a temperature of $20\,\mathrm{mK}$ for
nanowires of various sizes using the magnetomotive scheme. The measured values
of the resonance frequency agree with the estimates obtained from the
Euler-Bernoulli theory. The measured internal quality factor of the
$5\,\mathrm{\mu m}$-long resonator, $3.62\times10^4$, exceeds the corresponding
values of similar resonators investigated at higher temperatures. The
structures presented can be used as mass sensors with an expected sensitivity
$\sim 6 \times 10^{-20}\,\mathrm{g}\,\mathrm{Hz}^{-1/2}$.",1809.07215v1
2018-10-12,On the Calculation of Resonances in Pre-Born-Oppenheimer Molecular Structure Theory,"The main motivation for this work is the exploration of
rotational-vibrational states corresponding to electronic excitations in a
pre-Born-Oppenheimer quantum theory of molecules. These states are often
embedded in the continuum of the lower-lying dissociation channel of the same
symmetry, and thus are thought to be resonances. In order to calculate
rovibronic resonances, the pre-Born-Oppenheimer variational approach of [J.
Chem. Phys. 137, 024104 (2012)], based on the usage of explicitly correlated
Gaussian functions and the global vector representation, is extended with the
complex coordinate rotation method. The developed computer program is used to
calculate resonance energies and widths for the three-particle positronium
anion, Ps$^-$, and the four-particle positronium molecule, Ps$_2$. Furthermore,
the excited bound and resonance rovibronic states of the four-particle H$_2$
molecule are also considered. Resonance energies and widths are estimated for
the lowest-energy resonances of H$_2$ beyond the $b\ ^3\Sigma_\mathrm{u}^+$
continuum.",1810.05493v1
2018-10-25,All-dielectric resonant meta-optics goes active,"All-dielectric resonant nanophotonics is a rapidly developing research field
driven by its exceptional application potential for low-loss nanoscale
metadevices. The tight confinement of the local electromagnetic fields and
interferences in resonant photonic nanostructures can boost many optical
effects, thus offering novel opportunities for the subwavelength control of
light-matter-interactions. Active, light-emitting nanoscale structures are of
particular interest, as they offer unique opportunities for novel types of
light sources and nanolasers. Here, we review the latest advances in this
recently emerged and rapidly growing field of active dielectric resonant
nanophotonics enabled by dipolar and multipolar Mie-type resonances. More
specifically, we discuss how to employ dielectric nanostructures for the
resonant control of emission from quantum dots, two-dimensional transition
metal dichalcogenides, and halide perovskites. We also foresee various future
research directions and applications of active all-dielectric resonant
nanostructures including but not limited to lasing in topologically robust
systems, light-matter interactions beyond the electric dipole limit,
light-emitting surfaces, and tunable active metadevices.",1810.10675v1
2019-06-06,Beyond $M_{t\bar{t}}$: learning to search for a broad $t\bar t$ resonance at the LHC,"A resonance peak in the invariant mass spectrum has been the main feature of
a particle at collider experiments. However, broad resonances not exhibiting
such a sharp peak are generically predicted in new physics models beyond the
Standard Model. Without a peak, how do we discover a broad resonance at
colliders? We use machine learning technique to explore answers beyond common
knowledge. We learn that, by applying deep neural network to the case of a
$t\bar{t}$ resonance, the invariant mass $M_{t\bar{t}}$ is still useful, but
additional information from off-resonance region, angular correlations, $p_T$,
and top jet mass are also significantly important. As a result, the improved
LHC sensitivities do not depend strongly on the width. The results may also
imply that the additional information can be used to improve narrow-resonance
searches too. Further, we also detail how we assess machine-learned
information.",1906.02810v2
2019-06-28,Chirped temporal solitons in driven optical resonators,"Temporal solitons in driven microresonator, fiber-resonator, and bulk
enhancement cavities enable attractive optical sources for spectroscopy,
communications, and metrology. Here we present theoretical and experimental
observations of a new class of temporal optical soliton characterized by pulses
with large and positive chirp in normal dispersion resonators with strong
spectral filtering. Numerical simulations reveal stable waveforms over a wide
new range of parameters including highly chirped pulses at large drive powers.
Chirped temporal solitons matching predictions are observed in experiments with
normal dispersion fiber resonators strongly driven with nanosecond pulses.
Scaling laws are developed and provide simple design guidelines for generating
chirped temporal solitons in bulk- and micro-resonator, in addition to
fiber-resonator platforms. The relationship between the chirped solutions and
other stable waveforms in normal and anomalous dispersion resonators is
examined. Chirped temporal solitons represent a promising new resource for
frequency-comb and ultrashort-pulse generation.",1906.12127v1
2019-07-10,Intrinsic multipolar contents of nanoresonators for tailored scattering,"We introduce a theoretical and computational method to design resonant
objects, such as nanoantennas or meta-atoms, exhibiting tailored multipolar
responses. In contrast with common approaches that rely on a multipolar
analysis of the scattering response of an object upon specific excitations, we
propose to engineer the \textit{intrinsic} (i.e., excitation-independent)
multipolar content and spectral characteristics of the natural resonances -- or
quasinormal modes -- of the object. A rigorous numerical approach for the
multipolar decomposition of resonances at complex frequencies is presented,
along with an analytical model conveying a direct physical insight into the
multipole moments induced in the resonator. Our design strategy is illustrated
by designing a subwavelength optical resonator exhibiting a Janus resonance
that provides side-dependent coupling to waveguides over the full linewidth of
the resonance and on a wide angular range for linearly-polarized incident
planewaves. The method applies to all kinds of waves and may open new
perspectives for subwavelength-scale manipulation of scattering and emission.",1907.04598v3
2019-07-22,Resonance Effects in the Raman Optical Activity Spectrum of [Rh(en)$_3$]$^{3+}$,"Raman optical activity spectra of
$\Lambda$-tris-(ethylenediamine)-rhodium(III) ([Rh(en)$_3$]$^{3+}$) have been
calculated at 16 on-, near-, and off-resonant wavelengths between 290 nm and
800 nm. The resulting spectra are analyzed in detail with a focus on the
observed resonance effects. Since several electronically excited states are
involved, the spectra are never monosignate, as is often observed in resonance
Raman optical activity spectra. Most normal modes are enhanced through these
resonance effects, but in several cases, de-enhancement effects are found. The
molecular origins of the Raman optical activity intensity for selected normal
modes are established by means of group coupling matrices. In general, this
methodology allows one to produce an intuitive explanation for the intensity
behavior of a given normal mode. However, due to the complex electronic
structure of [Rh(en)$_3$]$^{3+}$, there are some intriguing resonance effects
the origins of which could not be fully clarified in terms of group coupling
effects. Therefore, simple and general rules that predict how the intensity of
a specific normal mode is affected by resonance effects are difficult to
devise.",1907.09243v3
2019-09-03,Frequency stabilization and noise-induced spectral narrowing in resonators with zero dispersion,"Mechanical resonators are widely used as precision clocks and sensitive
detectors that rely on the stability of their eigenfrequencies. The phase noise
is determined by different factors ranging from thermal noise and frequency
noise of the resonator to noise in the feedback circuitry. Increasing the
vibration amplitude can mitigate some of these effects but the improvements are
limited by nonlinearities that are particularly strong for miniaturized micro-
and nano-mechanical systems. Here we design a micromechanical resonator with
non-monotonic dependence of the frequency of eigenoscillations on energy. Near
the extremum, where the dispersion of the eigenfrequency is zero, the system
regains certain characteristics of a linear resonator, albeit at large
vibration amplitudes. The spectral peak undergoes counter-intuitive narrowing
when the noise intensity is increased. With the resonator serving as the
frequency determining element in a feedback loop, the phase noise at the
extremum amplitude is three times smaller than the conventional nonlinear
regime. Zero dispersion phenomena open new opportunities for improving resonant
sensors and frequency references.",1909.01090v2
2019-09-16,Dielectric loss extraction for superconducting microwave resonators,"The investigation of two-level-state (TLS) loss in dielectric materials and
interfaces remains at the forefront of materials research in superconducting
quantum circuits. We demonstrate a method of TLS loss extraction of a thin film
dielectric by measuring a lumped element resonator fabricated from a
superconductor-dielectric-superconductor trilayer. We extract the dielectric
loss by formulating a circuit model for a lumped element resonator with TLS
loss and then fitting to this model using measurements from a set of three
resonator designs: a coplanar waveguide resonator, a lumped element resonator
with an interdigitated capacitor, and a lumped element resonator with a
parallel plate capacitor that includes the dielectric thin film of interest.
Unlike other methods, this allows accurate measurement of materials with TLS
loss lower than $10^{-6}$. We demonstrate this method by extracting a TLS loss
of $1.02 \times 10^{-3}$ for sputtered $\mathrm{Al_2O_3}$ using a set of
samples fabricated from an $\mathrm{Al/Al_2O_3/Al}$ trilayer. We observe a
difference of 11$\%$ between extracted loss of the trilayer with and without
the implementation of this method.",1909.07428v2
2019-09-18,Deep water gravity wave triad resonances on uniform flow,"Triad resonances for gravity waves propagating in opposite direction with
respect to uniform current are introduced. They are produced by multivalued and
anisotropic dispersion and occur even in deep water. In contrast, existing
literature suggests non-degenerate deep water triads require inhomogeneity or
capillary effects. In this sense, the new resonances are a first of their kind.
Analytical conditions for the existence of resonance may be reduced to
universal constants. Solution of a three-wave interaction model, adapted to the
wave-current problem, shows regimes wherein the dominant direction, speed and
strength of resonant energy transfer differs between wavenumber scales. This
suggests uniform current is a fundamental source of spatial inhomogeneity. The
new resonances significantly modify the picture of nonlinear interactions in
wave-current fields. Since the resonances are quadratic, they will also
dominate well known quartet interactions.",1909.08501v1
2019-10-04,Solid-state laser refrigeration of a semiconductor optomechanical resonator,"Photothermal heating represents a major constraint that limits the
performance of many nanoscale optoelectronic and optomechanical devices
including nanolasers, quantum optomechanical resonators, and integrated
photonic circuits. Although radiation-pressure damping has been reported to
cool an individual vibrational mode of an optomechanical resonator to its
quantum ground state, to date the internal material temperature within an
optomechanical resonator has not been reported to cool via laser excitation.
Here we demonstrate the direct laser refrigeration of a semiconductor
optomechanical resonator >20K below room temperature based on the emission of
upconverted, anti-Stokes photoluminescence of trivalent ytterbium ions doped
within a yttrium-lithium-fluoride (YLF) host crystal. Optically-refrigerating
the lattice of a dielectric resonator has the potential to impact several
fields including scanning probe microscopy, the sensing of weak forces, the
measurement of atomic masses, and the development of radiation-balanced
solid-state lasers. In addition, optically refrigerated resonators may be used
in the future as a promising starting point to perform motional cooling for
exploration of quantum effects at mesoscopic length scales,temperature control
within integrated photonic devices, and solid-state laser refrigeration of
quantum materials",1910.02153v1
2019-10-25,Possible traces of resonance signaling in the genome,"Although theories regarding the role of sequence-specific DNA resonance in
biology have abounded for over 40 years, the published evidence for it is
lacking. Here, the authors reasoned that for sustained resonance signaling, the
number of oscillating DNA sequences per genome should be exceptionally high and
that, therefore, genomic repeats of various sizes are good candidates for
serving as resonators. Moreover, it was suggested that for the two DNA
sequences to resonate, they do not necessarily have to be identical. Therefore,
the existence of sequences differing in the primary sequence but having similar
resonating sub-structures was proposed. It was hypothesized that such
sequences, named HIDERs, would be enriched in the genomes of multicellular
species. Specifically, it was hypothesized that delocalized electron clouds of
purine-pyrimidine sequences could serve as the basis of HIDERs. The consequent
genomic analysis confirmed the enrichment of purine-pyrimidine HIDERs in a few
selected genomes of mammals, an insect, and a plant, compared to randomized
sequence controls. Similarly, it was suggested that hypothetical delocalized
proton clouds of the hydrogen bonds of multiple stacked bases could serve as
sequence-dependent hydrogen-bond-based HIDERs. Similarly, the enrichment of
such HIDERs was observed. It is suggested that these enrichments are the first
evidence in support of sequence-specific resonance signaling in the genome.",1910.11507v1
2020-01-25,Asymptotic modeling of Helmholtz resonators including thermoviscous effects,"We systematically employ the method of matched asymptotic expansions to model
Helmholtz resonators, with thermoviscous effects incorporated starting from
first principles and with the lumped parameters characterizing the neck and
cavity geometries precisely defined and provided explicitly for a wide range of
geometries. With an eye towards modeling acoustic metasurfaces, we consider
resonators embedded in a rigid surface, each resonator consisting of an
arbitrarily shaped cavity connected to the external half-space by a small
cylindrical neck. The bulk of the analysis is devoted to the problem where a
single resonator is subjected to a normally incident plane wave; the model is
then extended using ""Foldy's method"" to the case of multiple resonators
subjected to an arbitrary incident field. As an illustration, we derive
critical-coupling conditions for optimal and perfect absorption by a single
resonator and a model metasurface, respectively.",2001.09353v1
2020-02-06,Information Geometric Perspective on Off-Resonance Effects in Driven Two-Level Quantum Systems,"We present an information geometric analysis of off-resonance effects on
classes of exactly solvable generalized semi-classical Rabi systems.
Specifically, we consider population transfer performed by four distinct
off-resonant driving schemes specified by su(2; C) time-dependent Hamiltonian
models. For each scheme, we study the consequences of a departure from the
on-resonance condition in terms of both geodesic paths and geodesic speeds on
the corresponding manifold of transition probability vectors. In particular, we
analyze the robustness of each driving scheme against off-resonance effects.
Moreover, we report on a possible tradeoff between speed and robustness in the
driving schemes being investigated. Finally, we discuss the emergence of a
different relative ranking in terms of performance among the various driving
schemes when transitioning from on-resonant to off-resonant scenarios.",2002.02248v1
2020-04-24,Study of single-particle resonant states with Green's function method,"The relativistic mean field theory with the Green's function method is taken
to study the single-particle resonant states. Different from our previous work
[Phys.Rev.C 90,054321(2014)], the resonant states are identified by searching
for the poles of Green's function or the extremes of the density of states.
This new approach is very effective for all kinds of resonant states, no matter
it is broad or narrow. The dependence on the space size for the resonant
energies, widths, and the density distributions in the coordinate space has
been checked and it is found very stable. Taking $^{120}$Sn as an example, four
new broad resonant states $2g_{7/2}$, $2g_{9/2}$, $2h_{11/2}$ and $1j_{13/2}$
are observed, and also the accuracy for the width of the very narrow resonant
state $1h_{9/2}$ is highly improved to be $1\times 10^{-8}$ MeV. Besides, our
results are very close to those by the complex momentum representation method
and the complex scaling method.",2004.11632v1
2020-12-23,Searching optimal conditions for quantum gates application with the new 3-body Förster resonances in Rb and Cs Rydberg atoms,"Three body resonant interactions between Rydberg atoms are considered in
order to perform few-body quantum gates. So far, the resonances found in cesium
or rubidium atoms relied on an adjacent two-body resonance which ceases to
exist for principal quantum numbers above $n \simeq 40$. We have proposed
recently a new class of 3-body interaction resonances in alkali-metal Rydberg
atoms [P. Cheinet \textit{et al.}, Quant. Elect. \textbf{50}, 213 (2020)],
which circumvienes this limit. We investigate here the relative strength
between this new class of 3-body interaction resonance and quasi-forbidden
2-body interaction resonances in rubidium and cesium Rydberg atoms. We then
identify the best case scenario for detecting and using this 3-body
interaction.",2012.12845v1
2021-01-04,Quasinormal modes expansions for nanoresonators made of absorbing dielectric materials: study of the role of static modes,"The interaction of light with photonic resonators is determined by the
eigenmodes of the system. Modal theories based on quasinormal modes provide a
natural tool to calculate and understand light scattering by nanoresonators. We
show that, in the case of resonators made of absorbing dielectric materials,
eigenmodes with zero eigenfrequency (static modes) play a key role in the modal
formalism. The excitation of static modes builds a non-resonant contribution to
the modal expansion of the scattered field. This non-resonant term plays a
crucial physical role since it largely contributes to the off-resonance signal
to which resonances are added in amplitude, possibly leading to interference
phenomena and Fano resonances. By considering light scattering by a silicon
nanosphere, we quantify the impact of static modes. This study shows that the
importance of static modes is not just formal. Modal expansions without static
modes reconstruct an incorrect internal field and incorrect extinction and
absorption cross-sections. Static modes are of prime importance in an expansion
truncated to only a few modes.",2101.00968v1
2021-01-09,Semi-insulating 4H-SiC lateral bulk acoustic wave resonators,"Silicon carbide (SiC) excels in its outstanding mechanical properties, which
are widely studied in Microelectromechanical systems (MEMS). Recently, the
mechanical tuning of color centers in 4H-SiC has been demonstrated, broadening
its application in quantum spintronics. The strain generated in a mechanical
resonator can be used to manipulate the quantum state of the color center
qubit. This work reports a lateral overtone mechanical resonator fabricated
from a semi-insulating (SI) bulk 4H-SiC wafer. An aluminum nitride (AlN)
piezoelectric transducer on SiC is used to drive the resonance. The resonator
shows a series of modes with quality factors (Q) above 3000. An acoustic
reflector positioned at the anchor shows a 22% improvement in the Q at 300 MHz
resonance and suppresses the overtone modes away from it. This monolithic SiC
resonator allows optical access to the SiC color centers from both sides of the
wafer, enabling convenient setup in quantum measurements.",2101.03281v3
2017-05-03,Electrically tuned Förster resonances in collisions of NH$_3$ with Rydberg He atoms,"Effects of weak electric fields on resonant energy transfer between NH$_3$ in
the X $^1$A$_1$ ground electronic state, and Rydberg He atoms in triplet states
with principal quantum numbers $n = 36$-$41$ have been studied in a crossed
beam apparatus. For these values of $n$, electric-dipole transitions between
the Rydberg states that evolve adiabatically to the $|ns\rangle$ and
$|np\rangle$ states in zero electric field can be tuned into resonance with the
ground-state inversion transitions in NH$_3$ using electric fields, with energy
transfer occurring via F\""orster resonance. In the experiments the Rydberg He
atoms, traveling in pulsed supersonic beams, were prepared by resonant
two-photon excitation from the metastable $1s2s\,^3S_1$ level and crossed an
effusive beam of NH$_3$ before being detected by state-selective
pulsed-electric-field ionization. The resonant-energy-transfer process was
identified by monitoring changes in the ionization signal from the $|ns\rangle$
and $|np\rangle$ Rydberg states for each value of $n$. The electric field
dependence of the experimental data is in good agreement with the results of
calculations in which the resonant dipole-dipole coupling between the collision
partners was accounted for.",1705.01487v1
2017-11-21,Superconducting micro-resonator arrays with ideal frequency spacing and extremely low frequency collision rate,"We present a wafer trimming technique for producing superconducting
micro-resonator arrays with highly uniform frequency spacing. With the
light-emitting diode (LED) mapper technique demonstrated previously, we first
map the measured resonance frequencies to the physical resonators. Then, we
fine-tune each resonator's frequency by lithographically trimming a small
length, calculated from the deviation of the measured frequency from its design
value, from the interdigitated capacitor. We demonstrate this technique on a
127-resonator array made of titanium-nitride (TiN) and show that the uniformity
of frequency spacing is greatly improved. The array yield in terms of frequency
collisions improves from 84% to 97%, while the quality factors and noise
properties are unaffected. The wafer trimming technique provides an
easy-to-implement tool to improve the yield and multiplexing density of large
resonator arrays, which is important for various applications in photon
detection and quantum computing.",1711.07914v1
2018-06-30,Microresonators fabricated from high-kinetic-inductance Aluminum films,"We have studied superconducting coplanar-waveguide (CPW) resonators
fabricated from disordered (granular) films of Aluminum. Very high kinetic
inductance of these films, inherent to disordered materials, allows us to
implement ultra-short (200 $\mu$m at a 5GHz resonance frequency) and
high-impedance (up to 5 k$\Omega$) half-wavelength resonators. We have shown
that the intrinsic losses in these resonators at temperatures $\lesssim 250$ mK
are limited by resonator coupling to two-level systems in the environment. The
demonstrated internal quality factors are comparable with those for CPW
resonators made of conventional superconductors. High kinetic inductance and
well-understood losses make these disordered Aluminum resonators promising for
a wide range of microwave applications which include kinetic inductance photon
detectors and superconducting quantum circuits.",1807.00210v1
2018-07-06,Scalar resonance in a top partner model,"The phenomenology entailed by a scalar resonance in a top partner model is
analysed here in a $SO(5)$ Composite Higgs formalism. Heavy scalar resonances
production and their decays modes are explored along a benchmark resonance mass
range. The production of single-double partner final states has been scanned
along the partner mass scale. QCD drives such production, as well as the SM
gauge, Higgs, plus the intermediation of the scalar resonance. Non-zero
contributions are induced as long as extra fermion-resonance effects are
included. Finally, we have excluded regions of the parameter spaces underlying
our framework by imposing the recent LHC searches for vector-like quarks
production in $pp$-collisions at 13 TeV. Substantial reduction of the allowed
regions occurs if extra fermion-resonance effects are accounted for, leading us
to test the involved parametric dependence in the shed light of new matter
interactions.",1807.02211v2
2018-07-07,White Dwarf Pollution by Asteroids from Secular Resonances,"In the past few decades, observations have revealed signatures of metals
polluting the atmospheres of white dwarfs. The diffusion timescale for metals
to sink from the atmosphere of a white dwarf is of the order of days for a
hydrogen-dominated atmosphere. Thus, there must be a continuous supply of
metal-rich material accreting onto these white dwarfs. We investigate the role
of secular resonances that excite the eccentricity of asteroids allowing them
to reach star-grazing orbits leading them to tidal disruption and the formation
of a debris disc. Changes in the planetary system during the evolution of the
star lead to a change in the location of secular resonances. In our Solar
System, the engulfment of the Earth will cause the $\nu_6$ resonance to shift
outwards which will force previously stable asteroids to undergo secular
resonant perturbations. With analytic models and $N$--body simulations we show
that secular resonances driven by two outer companions can provide a source of
continuous pollution. Secular resonances are a viable mechanism for the
pollution of white dwarfs in a variety of exoplanetary system architectures.",1807.02610v1
2018-07-10,Multiphoton Quantum Logic Gates for Superconducting Resonators with Tunable Nonlinear Interaction,"We propose a tunable nonlinear interaction for the implementation of quantum
logic operations on pairs of superconducting resonators, where the
two-resonator interaction is mediated by a transmon quantum bit (qubit). This
interaction is characterized by a high on-to-off coupling ratio and allows for
fast qubit-type and $d$-level system (qudit)-type operations for quantum
information processing with multiphoton cavity states. We present analytical
and numerical calculations showing that these operations can be performed with
practically unit fidelity in absence of any dissipative phenomena, whereas
physical two-photon two-resonator operations can be realized with a fidelity of
99.9% in presence of qubit and resonator decoherence. The
resonator-qubit-resonator system proposed in this Letter can be implemented
using available planar or three-dimensional microwave technology.",1807.03820v1
2018-07-13,Temperature dependence of an Efimov resonance in $^{39}\mathrm{K}$,"Ultracold atomic gases are an important testing ground for understanding
few-body physics. In particular, these systems enable a detailed study of the
Efimov effect. We use ultracold $^{39}\mathrm{K}$ to investigate the
temperature dependence of an Efimov resonance. The shape and position of the
observed resonance are analyzed by employing an empirical fit, and universal
finite-temperature zero-range theory. Both procedures suggest that the
resonance position shifts towards lower absolute scattering lengths when
approaching the zero-temperature limit. We extrapolate this shift to obtain an
estimate of the three-body parameter at zero temperature. A surprising finding
of our study is that the resonance becomes less prominent at lower
temperatures, which currently lacks a theoretical description and implies
physical effects beyond available models. Finally, we present measurements
performed near the Feshbach resonance center and discuss the prospects for
observing the second Efimov resonance in $^{39}\mathrm{K}$.",1807.05001v2
2018-06-24,Tunable large free spectral range microring resonators in lithium niobate on insulator,"Microring resonators are critical photonic components used in filtering,
sensing and nonlinear applications. To date, the development of high
performance microring resonators in LNOI has been limited by the sidewall
angle, roughness and etch depth of fabricated rib waveguides. We present large
free spectral range microring resonators patterned via electron beam
lithography in high-index contrast $Z$-cut LNOI. Our microring resonators
achieve an FSR greater than 5 nm for ring radius of 30 $\mu$m and a large 3 dB
resonance bandwidth. We demonstrate 3 pm/V electro-optic tuning of a 70
$\mu$m-radius ring. This work will enable efficient on-chip filtering in LNOI
and precede future, more complex, microring resonator networks and nonlinear
field enhancement applications.",1807.06531v2
2018-08-03,Definition of the interlayer interaction type in magnetic multilayers analyzing the shape of the ferromagnetic resonance peaks,"We present theoretical study of ferromagnetic resonance in a system of two
coupled magnetic layers. We show that an interaction between the layers leads
to the occurrence of the so-called Fano resonance. The Fano resonance changes
the shape of the ferromagnetic resonance peak. It introduces a peak asymmetry.
The asymmetry type is defined by the sign of the interaction between the
magnetic layers. Therefore, studying the shape of the ferromagnetic resonance
peaks one can define the type of the interlayer coupling (ferromagnetic or
antiferromagnetic). We show that using numerical simulations one can estimate a
magnitude of the interaction by fitting the asymmetric resonance peaks.",1808.01296v1
2018-08-16,Mott-Insulator-Aided Detection of Ultra-Narrow Feshbach Resonances,"We report on the detection of extremely narrow Feshbach resonances by
employing a Mott-insulating state for cesium atoms in a three-dimensional
optical lattice. The Mott insulator protects the atomic ensemble from high
background three-body losses in a magnetic field region where a broad Efimov
resonance otherwise dominates the atom loss in bulk samples. Our technique
reveals three ultra-narrow and previously unobserved Feshbach resonances in
this region with widths below $\approx 10\,\mu$G, measured via
Landau-Zener-type molecule formation and confirmed by theoretical predictions.
For comparatively broader resonances we find a lattice-induced substructure in
the respective atom-loss feature due to the interplay of tunneling and strong
particle interactions. Our results provide a powerful tool to identify and
characterize narrow scattering resonances, particularly in systems with complex
Feshbach spectra. The observed ultra-narrow Feshbach resonances could be
interesting candidates for precision measurements.",1808.05496v1
2018-08-30,Tuning of envelope in high overtone bulk acoustic wave resonator,"This report presents a robust composite resonator known as the high overtone
bulk acoustic wave resonator (HBAR) for demonstrating experimentally the
ability of the resonator to tune the envelope of the spectrum by applying dc
bias. The reported HBAR exhibits exceptionally high-quality factor in the
frequency range of 700 MHz to 3 GHz and high effective coupling coefficient
over the broad range of microwave frequencies. The HBAR is based on thin
Ba0.5Sr0.5TiO3 film sandwiched between two electrodes forming a transducer,
supported by a thick sapphire substrate which is a low acoustic loss material.
The resonator works on the principle of induced piezoelectricity due to the
applied dc bias. The minima of the envelope changes from 1.16 GHz with S11 of
-3.51 dB at 100 kV/cm bias to 1.90 GHz with S11 of -42.23 dB at 700 kV/cm bias,
giving a relative tunability of the envelope to be around 64%. The spacing of
the parallel resonance frequency (SPRF) for different bias voltages are also
presented in this report. The quality factor of the resonator is over 22,000 at
around 2GHz.",1808.10115v1
2018-12-10,Width and shift of Fano-Feshbach resonances for van der Waals interactions,"We revisit the basic properties of Fano-Feshbach resonances in two-body
systems with van der Waals tail interactions, such as ultracold neutral atoms.
Using a two-channel model and two different methods, we investigate the
relationship between the width and shift of the resonances and their dependence
on the low-energy parameters of the system. Unlike what was previously believed
[Rev. Mod. Phys. 82, 1225 (2010)] for magnetic resonances, we find that the
ratio between the width and the shift of a resonance does not depend only on
the background scattering length, but also on a closed-channel scattering
length. We obtain different limits corresponding to different cases of optical
and magnetic resonances. Although the generalisation of the theory to the
multi-channel case remains to be done, we found that our two-channel
predictions are verified for a specific resonance of lithium-6.",1812.03903v3
2018-12-16,GHz nanomechanical resonator in an ultraclean suspended graphene p-n junction,"We demonstrate high-frequency mechanical resonators in ballistic graphene p-n
junctions. Fully suspended graphene devices with two bottom gates exhibit
ballistic bipolar behavior after current annealing. We determine the graphene
mass density and built-in tension for different current annealing steps by
comparing the measured mechanical resonant response to a simplified membrane
model. We consistently find that after the last annealing step the mass density
compares well with the expected density of pure graphene. In a graphene
membrane with high built-in tension, but still of macroscopic size with
dimensions 3 $\times$ 1 $\mu m^{2}$, a record resonance frequency of 1.17 GHz
is observed after the final current annealing step. We further compare the
resonance response measured in the unipolar with the one in the bipolar regime.
Remarkably, the resonant signals are strongly enhanced in the bipolar regime.
This enhancement is caused in part by the Fabry-Perot resonances that appear in
the bipolar regime and possibly also by the photothermoelectric effect that can
be very pronounced in graphene p-n junctions under microwave irradiation.",1812.06412v2
2019-01-05,General mathematical analysis on multiple solutions of interfering resonances combinations,"When fitting cross sections with several resonances or interfering background
and resonances, one usually obtains multiple solutions of parameters with equal
fitting quality. In the present work, we find the source of multiple solutions
for a combination of several resonances or interfering background and
resonances by analyzing the mathematical structure of the Breit-Wigner
function. We find that there are $2^n$ fitting solutions with equal quality for
$n+1$ resonances, and the multiplicity of the interfering background and
resonances depends on zeros of the amplitudes in the complex plane. We provide
a simple, general method to infer all other solutions with equal fitting
quality from a known solution.",1901.01394v2
2019-01-07,Coupled mechanical resonators with broken Lorentz reciprocity for sensor applications,"Having simultaneously a high quality factor (i.e. a narrow resonant band) and
a shorter interaction time between the resonating system and the external
sources (i.e. a wide resonant band) is a desirable characteristic for
mechanical resonators, which however has been regarded as contradictory. This
has been known as the limit of Lorentz reciprocity. We explore a configuration
to achieve this desired characteristic within the mechanical regime. The
configuration consists of a pair of mechanical resonators coupled together
through their connecting part. One of them is encapsulated in a vacuum
environment, and the other is left in the normal ambient condition. Numerical
model of this configuration shows clearly the advantages such as: (a),
sensitivity to the change of resonant frequency is greatly improved (the
product of bandwidth $\Delta \omega$ and the interaction time $\Delta t$ has
increased at least two orders of magnitude); (b), the value of $\Delta \omega
\cdot \Delta t$ can be adjusted through the coupling stiffness.",1901.01770v2
2019-02-06,Parametric Resonances and Resonant Delocalization in Quasi-Phase Matched Photon-pair Generation and Quantum Frequency Conversion,"The existing widely-accepted theory of photon-pair generation via spontaneous
down-conversion (SPDC) in nonlinear optical crystals and waveguides is
incomplete, as it fails to account for the important physical phenomenon of
parametric resonances. We demonstrate that exponential gain of classical fields
in the regime of parametric resonance corresponds to resonant delocalization in
the Glauber-Fock model of quantum SPDC. We propose a quantitative measure of
localisation of Floquet eigen-modes as an analogue of classical gain to
identify regimes of resonant delocalization. Using this method, we are able to
reconstruct the classical ""Arnold tongues"" map of domains of instabilities for
SPDC. We also predict novel regimes of resonant delocalization in the two-level
model describing quantum frequency conversion processes.",1902.02214v1
2019-02-14,Breakdown of the Hebel-Slichter effect in superconducting graphene due to the emergence of Yu-Shiba-Rusinov states at magnetic resonant scatterers,"Employing analytical methods and quantum transport simulations we investigate
the relaxation of quasiparticle spins in graphene proximitized by an $s$-wave
superconductor in the presence of resonant magnetic and spin-orbit active
impurities. Off resonance, the relaxation increases with decreasing temperature
when electrons scatter off magnetic impurities---the Hebel-Slichter
effect---and decreases when impurities have spin-orbit coupling. This distinct
temperature~dependence (not present in the normal state) uniquely discriminates
between the two scattering mechanisms. However, we show that the Hebel-Slichter
picture breaks down at resonances. The emergence of Yu-Shiba-Rusinov bound
states within the superconducting gap redistributes the spectral weight away
from magnetic resonances. The result is opposite to the Hebel-Slichter
expectation: the spin relaxation decreases with decreasing temperature. Our
findings hold for generic $s$-wave superconductors with resonant magnetic
impurities, but also, as we show, for resonant magnetic Josephson junctions.",1902.05474v2
2019-03-14,"Quartet, higher order and near resonant interactions in nonlinear wave equations","Motivated by problems arising in geophysical fluid dynamics, we investigate
resonant and near resonant wave interactions in nonlinear wave equations with
quadratic nonlinearity, We place a special focus on interactions between slow
wave modes, with zero frequency in the linear limit, and fast modes. These
regularly occur in geophysical fluid systems with conserved potential vorticity
or similar conserved quantities. A general multi-scale asymptotic expansion is
used to show how the higher order nonlinear interaction coefficients are
derived as a combination of the first order terms arising at the triad
interaction level. From the general nth-order interaction coefficient we
present a proof by induction how the limiting effect for particular
combinations of slow and fast modes pushes their interactions to a slower
timescale, and we show how this is linked to the form of the conserved
quantities. We compare near resonant expansions with exact resonant expansions,
and show how near-resonances allow higher order expansions to be reduced to
just the most dominant contributions. These contributions then occur at one
order higher in the expansion when compared to the analogous exact resonance
expansion.",1903.06265v1
2019-04-04,Exciting mutual inclination in planetary systems with a distant stellar companion: the case of Kepler-108,"We study the excitation of mutual inclination between planetary orbits by a
novel secular-orbital resonance in multiplanet systems perturbed by binary
companions which we call ""ivection"". The ivection resonance happens when the
nodal precession rate of the planet matches a multiple of the orbital frequency
of the binary, and its physical nature is similar to the previously-studied
evection resonance. Capture into an ivection resonance requires encountering
the resonance with slowly increasing nodal precession rate, and it can excite
the mutual inclination of the planets without affecting their eccentricities.
We discuss the possible outcomes of ivection resonance capture, and we use
simulations to illustrate that it is a promising mechanism for producing the
mutual inclination in systems where planets have significant mutual inclination
but modest eccentricity, such as Kepler-108. We also find an apparent deficit
of multiplanet systems which would have nodal precession period comparable to
binary orbital period, suggesting that ivection resonance may inhibit the
formation or destablize multiplanet systems with external binary companion.",1904.02290v2
2019-11-01,Effect of color reconnection and rope formation on resonance production in p$-$p collisions in Pythia 8,"The resonance production in proton$-$proton collisions at $\sqrt{s}$ = 7 TeV
and 13 TeV have been investigated using Pythia 8 event generator within the
framework of microscopic processes like color reconnection and rope
hadronization. Specifically, the observable effects of different modes of color
reconnections on the ratio of yields of mesonic and baryonic resonances with
respect to their stable counterpart have been explored as a function of event
activity. A suppression in the ratio is observed as a function of number of
multi-partonic interactions for mesonic resonances. The $\mathrm{\phi/K}$ and
$\mathrm{\phi/\pi}$ ratios show an enhancement for high multiplicity events due
to enhanced production of strange quarks via the microscopic process of rope
hadronization in the partonic phase. The mechanism of the hadronization of
color ropes together with the QCD-based color reconnection of partons predicted
an enhancement in the ratio for baryonic resonances to non-resonance baryons
having similar quark content. The yield ratios of resonances are found to be
independent of the collision energy and strongly dependent on event activity.",1911.00559v1
2019-11-12,Effect of the resonance spectra in the propagation of two decaying entangled particles,"An exact analytical solution of the decaying wave function of two identical
noninteracting particles, which are entangled by spatial symmetry, is used to
analyze the effect of the resonance spectra in the propagation of the decaying
probability density outside the interaction potential region. We find, using
exactly solvable problems, that a usual approximation that considers the two
resonance levels associated with the initial states, is affected substantially
in the case of sharp high energy resonances by disrupting the pure exponential
decaying regime exhibited by the two resonance level approximation, whereas for
broad high energy resonances, we find that the probability density profile is
well described by the two resonance approximation.",1911.05056v1
2020-05-11,Tunable coupling of two mechanical resonators by a graphene membrane,"Coupled nanomechanical resonators are interesting for both fundamental
studies and practical applications as they offer rich and tunable oscillation
dynamics. At present, the mechanical coupling in such systems is often mediated
by a fixed geometry, such as a joint clamping point of the resonators or a
displacement-dependent force. Here we show a graphene-integrated
electromechanical system consisting of two physically separated mechanical
resonators -- a comb-drive actuator and a suspended silicon beam -- that are
tunably coupled by a graphene membrane. The graphene membrane, moreover,
provides a sensitive electrical read-out for the two resonating systems silicon
structures showing 16 different modes in the frequency range from 0.4~to
24~MHz. In addition, by pulling on the graphene membrane with an electrostatic
potential applied to one of the silicon resonators, we control the mechanical
coupling, quantified by the $g$-factor, from 20 kHz to 100 kHz. Our results
pave the way for coupled nanoelectromechanical systems requiring controllable
mechanically coupled resonators.",2005.05358v2
2020-05-19,On the detuned 2:4 resonance,"We consider families of Hamiltonian systems in two degrees of freedom with an
equilibrium in 1:2 resonance. Under detuning, this ""Fermi resonance"" typically
leads to normal modes losing their stability through period-doubling
bifurcations. For cubic potentials this concerns the short axial orbits and in
galactic dynamics the resulting stable periodic orbits are called ""banana""
orbits. Galactic potentials are symmetric with respect to the co-ordinate
planes whence the potential -- and the normal form -- both have no cubic terms.
This $\mathbb{Z}_2 \times \mathbb{Z}_2$-symmetry turns the 1:2 resonance into a
higher order resonance and one therefore also speaks of the 2:4 resonance. In
this paper we study the 2:4 resonance in its own right, not restricted to
natural Hamiltonian systems where $H = T + V$ would consist of kinetic and
(positional) potential energy. The short axial orbit then turns out to be
dynamically stable everywhere except at a simultaneous bifurcation of banana
and ""anti-banana"" orbits, while it is now the long axial orbit that loses and
regains stability through two successive period-doubling bifurcations.",2005.09686v1
2020-09-28,Perturbation Theory of Optical Resonances of Deformed Dielectric Spheres,"Light injected into a spherical dielectric body may be confined very
efficiently via the mechanism of total internal reflection. The frequencies
that are most confined are called resonances. If the shape of the body deviates
from the perfect spherical form the resonances change accordingly. In this
thesis, a perturbation theory for the optical resonances of such a deformed
sphere is developed. The optical resonances of such an open system are
characterized by complex eigenvalues, where the real part relates to the
frequency of the resonant light and the imaginary part to the energy leakage
out of the system. As unperturbed and analytically solvable problem serves the
homogeneous dielectric sphere, and the corrections to its eigenvalues are
determined up to and including second order for any polarization of light. For
each order, the corrections of the optical resonances are determined by a
finite-dimensional linear eigenvalue equation, similar to degenerate
time-independent perturbation theory in quantum mechanics. Furthermore,
geometrically intuitive applicability criteria are derived. To check the
validity of the presented method, it is applied and compared to an analytically
solvable problem.",2009.14003v1
2020-11-23,Cavity-enhanced Ramsey spectroscopy at a Rydberg-atom-superconducting-circuit interface,"The coherent interaction of Rydberg helium atoms with microwave fields in a
$\lambda/4$ superconducting coplanar waveguide resonator has been exploited to
probe the spectral characteristics of an individual resonator mode. This was
achieved by preparing the atoms in the 1s55s$^3$S$_1$ Rydberg level by
resonance enhanced two-color two-photon excitation from the metastable
1s2s$^3$S$_1$ level. The atoms then travelled over the resonator in which the
third harmonic microwave field, at a frequency of
$\omega_{\mathrm{res}}=2\pi\times19.556$ GHz, drove the two-photon
1s55s$^3$S$_1\rightarrow$1s56s$^3$S$_1$ transition. By injecting a sequence of
Ramsey pulses into the resonator, and monitoring the coherent evolution of the
Rydberg state population by state-selective pulsed electric field ionization as
the frequency of the microwave field was tuned, spectra were recorded that
allowed the resonator resonance frequency and quality factor to be determined
with the atoms acting as microscopic quantum sensors.",2011.11326v1
2020-11-27,Quantum Computing for Atomic and Molecular Resonances,"The complex-scaling method can be used to calculate molecular resonances
within the Born-Oppenheimer approximation, assuming the electronic coordinates
are dilated independently of the nuclear coordinates. With this method, one
will calculate the complex energy of a non-Hermitian Hamiltonian, whose real
part is associated with the resonance position and the imaginary part is the
inverse of the lifetime. In this study, we propose techniques to simulate
resonances on a quantum computer. First, we transformed the scaled molecular
Hamiltonian to second-quantization and then used the Jordan-Wigner
transformation to transform the scaled Hamiltonian to the qubit space. To
obtain the complex eigenvalues, we introduce the Direct Measurement method,
which is applied to obtain the resonances of a simple one-dimensional model
potential that exhibits pre-dissociating resonances analogous to those found in
diatomic molecules. Finally, we applied the method to simulate the resonances
of the H$_2^-$ molecule. Numerical results from the IBM Qiskit simulators and
IBM quantum computers verify our techniques.",2011.13999v3
2021-02-09,Fabry-Perot Interferometric Calibration of 2D Nanomechanical Plate Resonators,"Displacement calibration of nanomechanical plate resonators presents a
challenging task. Large nanomechanical resonator thickness reduces the
amplitude of the resonator motion due to its increased spring constant and
mass, and its unique reflectance. Here, we show that the plate thickness,
resonator gap height, and motional amplitude of circular and elliptical drum
resonators, can be determined in-situ by exploiting the fundamental
interference phenomenon in Fabry-Perot cavities. The proposed calibration
scheme uses optical contrasts to uncover thickness and spacer height profiles,
and reuse the results to convert the photodetector signal to the displacement
of drumheads that are electromotively driven in their linear regime. Calibrated
frequency response and spatial mode maps enable extraction of the modal radius,
effective mass, effective driving force, and Young's elastic modulus of the
drumhead material. This scheme is applicable to any configuration of
Fabry-Perot cavities, including plate and membrane resonators.",2102.04705v1
2021-03-22,Sound Trapping in an Open Resonator,"The ability of extreme sound energy confinement with high-quality factor
(Q-factor) resonance is of vital importance for acoustic devices requiring high
intensity and hypersensitivity in biological ultrasonics, enhanced collimated
sound emission (i.e. sound laser) and high-resolution sensing. However,
structures reported so far demonstrated a limited quality factor (Q-factor) of
acoustic resonances, up to several tens in an open resonator. The emergence of
bound states in the continuum (BIC) makes it possible to realize high-Q factor
acoustic modes. Here, we report the theoretical design and experimental
demonstration of acoustic BICs supported by a single open resonator. We
predicted that such an open acoustic resonator could simultaneously support
three types of BICs, including symmetry protected BIC, Friedrich-Wintgen BIC
induced by mode interference, as well as a new kind of BIC: mirror-symmetry
induced BIC. We also experimentally demonstrated the existence of all three
types of BIC with Q-factor up to one order of magnitude greater than the
highest Q-factor reported in an open resonator.",2103.11581v1
2021-03-26,Resonant binding of dielectric particles to metal surface without plasmonics,"High index dielectric spherical particle supports the high-$Q$ resonant Mie
modes that results in a regular series of sharp resonances in the radiation
pressure. A presence of perfectly conducting metal surface transforms the Mie
modes into the extremely high-$Q$ magnetic bonding or electric anti-bonding
modes for close approaching of the sphere to the surface. We show that the
electromagnetic plane wave with normal incidence results in repulsive or
attractive resonant optical forces relative to metal for excitation of the
electric bonding or magnetic anti-bonding resonant modes respectively. A
magnitude of resonant optical forces reaches order of one nano Newton of
magnitude for micron size of silicon particles and power of light $1mW/\mu m^2$
that exceeds the gravitational force by four orders. However what is the most
remarkable there are steady positions for the sphere between pulling and
pushing forces that gives rise to resonant binding of the sphere by metal
surface. A frequency of mechanical oscillations of particle around the
equilibrium positions reaches a magnitude of order MHz.",2103.14219v1
2021-03-29,Acceleration-induced effects in stimulated light-matter interactions,"The interaction between light and an atom proceeds via three paradigmatic
mechanisms: spontaneous emission, stimulated emission, and absorption. All
three are resonant processes in the sense that they require that the radiation
field be resonant with the atomic transition. The non-resonant counterparts of
these effects, while necessary to maintain locality of the interaction in
principle, are usually negligible because their effects tend to average out
over multiple cycles of the radiation field. This state of affairs does not
hold if the atom is accelerated. We show that, when accelerated, the
non-resonant effects can be made to dominate over the conventional resonant
effects. In fact we show that the non-resonant effects can be vastly enhanced
by stimulation, and that suitably chosen acceleration can entirely suppress the
resonant effects. In the class of effects that we study, the Unruh effect is
the special case of vanishing stimulation.",2103.15838v1
2021-04-12,Structurally Tunable Nonlinear Terahertz Metamaterials using Broadside Coupled Split Ring Resonators,"We present an experimental and numerical study of a terahertz metamaterial
with a nonlinear response that is controllable via the relative structural
positioning of two stacked split ring resonator arrays. The first array is
fabricated on an n-doped GaAs substrate and the second array is fabricated
vertically above the first using a polyimide spacer layer. Due to GaAs carrier
dynamics, the on-resonance terahertz transmission at 0.4 THz varies in a
nonlinear manner with incident terahertz power. The second resonator layer
dampens this nonlinear response. In samples where the two layers are aligned,
the resonance disappears and total nonlinear modulation of the on-resonance
transmission decreases. The nonlinear modulation is restored in samples where
an alignment offset is imposed between the two resonator arrays. Structurally
tunable metamaterials can therefore act as a design template for tunable
nonlinear THz devices by controlling the coupling of confined electric fields
to nonlinear phenomena in a complex material substrate or inclusion.",2104.05757v1
2021-04-12,A study of the 1/2 retrograde resonance: Periodic orbits and resonant capture,"We describe the families of periodic orbits in the 2-dimensional 1/2
retrograde resonance at mass ratio 0.001, analyzing their stability and
bifurcations into 3-dimensional periodic orbits. We explain the role played by
periodic orbits in adiabatic resonance capture, in particular how the proximity
between a stable family and an unstable family with a nearly critical segment,
associated with Kozai separatrices, determines the transition between distinct
resonant modes observed in numerical simulations. Combining the identification
of stable, critical and unstable periodic orbits with analytical modeling,
resonance capture simulations and computation of stability maps helps to unveil
the complex 3-dimensional structure of resonances.",2104.05795v2
2021-05-10,"Resonant interaction in chiral, Eshelby-twisted van der Waals atomic layers","We study the electronic structures of chiral, Eshelby-twisted van der Waals
atomic layers with a particular focus on a chiral twisted graphite (CTG), a
graphene stack with a constant twist angle $\theta$ between successive layers.
We show that each CTG can host infinitely many resonant states which arise from
the interaction between the degenerate monolayer states of the constituent
layers. Each resonant state has a screw rotational symmetry, and may have a
smaller reduced Brillouin zone than other non-resonant states in the same
structure. And each CTG can have the resonant states with up to four different
screw symmetries. We derive the energies and wave functions of the resonant
states in a universal form of a one-dimensional chain regardless of $\theta$,
and show that these states exhibit a clear optical selection rule for
circularly polarized light. Finally, we discuss the uniqueness and existence of
the exact center of the lattice and the self-similarity of the wave amplitudes
of the resonant states.",2105.04139v2
2021-05-12,Dual-Resonance Enhanced Quantum Light-Matter Interactions In Deterministically Coupled Quantum-Dot-Micopillars,"Optical microcavities have widely been employed to enhance either the optical
excitation or the photon emission processes for boosting light matter
interactions at nanoscale. When both the excitation and emission processes are
simultaneously facilitated by the optical resonances provided by the
microcavities, as referred to the dual-resonance condition in this article, the
performances of many nanophotonic devices approach to the optima. In this work,
we present versatile accessing of dual-resonance conditions in
deterministically coupled quantum-dot(QD)-micopillars, which enables emission
from exciton (X) - charged exciton (CX) transition with improved single-photon
purity. In addition, the rarely observed up-converted single-photon emission
process is achieved under dual-resonance condition. We further exploit the
vectorial nature of the high-order cavity modes to significantly improve the
excitation efficiency under the dual-resonance condition. The dual-resonance
enhanced light-matter interactions in the quantum regime provides a viable path
for developing integrated quantum photonic devices based on cavity quantum
electrodynamics (QED) effect e.g., highly-efficient quantum light sources and
quantum logical gates.",2105.05480v2
2021-05-16,A Tidal Origin for a 3-body Resonance in Kepler-221,"Over the course of the last two decades, traditional models of planet
formation have been repeatedly challenged by the emerging census of extrasolar
planets. Key among them is the orbital architecture problem: while standard
models of orbital migration predict resonant orbits for short-period objects,
most planets do not appear to lie in orbital resonances. Here we show that the
four-planet system Kepler-221, not previously recognized to have active orbital
resonances, has a three-body commensurability relation unique within the Kepler
sample. Using a suite of numerical experiments as well as a perturbative
analysis, we demonstrate that this system likely began as a resonant chain and
proceeded to undergo large-scale divergence away from resonance, under the
action of tidal dissipation. Our results further indicate that obliquity tides,
driven by a secular spin-orbit resonance and mutual inclination, are an
excellent candidate for driving this orbital divergence, and that the high
tidal luminosity may also explain the anomalous size of planet b, which lies
within the Fulton radius gap.",2105.07368v1
2021-06-10,Broadband resonant calibration-free complex permittivity retrieval of liquid solutions,"Material susceptibilities govern interactions between electromagnetic waves
and matter and are of a crucial importance for basic understanding of natural
phenomena and for tailoring practical applications. Here we present a new
calibration-free method for relative complex permittivity retrieval, which
allows using accessible and cheap apparatus and simplifies the measurement
process. The method combines advantages of resonant and non-resonant
techniques, allowing to extract parameters of liquids and solids in a broad
frequency range, where material's loss tangent is less than 0.5. The essence of
the method is based on exciting magnetic dipole resonance in a spherical sample
with variable dimensions. Size-dependent resonant frequencies and quality
factors of magnetic dipolar modes are mapped on real and imaginary parts of
permittivity by employing Mie theory. Samples are comprised of liquid
solutions, enclosed in stretchable covers, which allows changing the dimensions
continuously. This approach allows tuning magnetic dipolar resonance over a
wide frequency range, effectively making resonance retrieval method broadband.
The technique can be extended to powder and solid materials, depending on their
physical parameters, such as granularity and processability.",2106.09458v2
2021-06-19,Ultrawide Frequency Tuning of Atomic Layer van der Waals Heterostructure Electromechanical Resonators,"We report on the experimental demonstration of atomically thin molybdenum
disulfide (MoS2)-graphene van der Waals (vdW) heterostructure
nanoelectromechanical resonators with ultrawide frequency tuning. With direct
electrostatic gate tuning, these vdW resonators exhibit exceptional tunability,
in general, {\Delta}f/f0 >200%, for continuously tuning the same device and the
same mode (e.g., from ~23 to ~107MHz), up to {\Delta}f/f0 = 370%, the largest
fractional tuning range in such resonators to date. This remarkable
electromechanical resonance tuning is investigated by two different analytical
models and finite element simulations. Further, we carefully perform clear
control experiments and simulations to elucidate the difference in frequency
tuning between heterostructure and single-material resonators. At a given
initial strain level, the tuning range depends on the two-dimensional (2D)
Young's moduli of the constitutive crystals; devices built on materials with
lower 2D moduli show wider tuning ranges. This study exemplifies that vdW
heterostructure resonators can retain unconventionally broad, continuous
tuning, which is promising for voltage-controlled, tunable nanosystems.",2106.10560v1
2021-07-13,An integrable model for first-order three-planet mean motion resonances,"Recent works on three-planet mean motion resonances (MMRs) have highlighted
their importance for understanding the details of the dynamics of planet
formation and evolution. While the dynamics of two-planet MMRs are well
understood and approximately described by a one degree of freedom Hamiltonian,
little is known of the exact dynamics of three-bodies resonances besides the
cases of zeroth-order MMRs or when one of the body is a test particle. In this
work, I propose the first general integrable model for first-order three-planet
mean motion resonances. I show that one can generalize the strategy proposed in
the two-planet case to obtain a one degree of freedom Hamiltonian. The dynamics
of these resonances are governed by the second fundamental model of resonance.
The model is valid for any mass ratio between the planets and for every
first-order resonance. I show the agreement of the analytical model with
numerical simulations. As examples of application I show how this model could
improve our understanding of the capture into MMRs as well as their role on the
stability of planetary systems.",2107.06299v1
2021-07-21,Influence of Shape Resonances on the Angular Dependence of Molecular Photoionization Delays,"Characterizing time delays in molecular photoionization as a function of the
ejected electron emission direction relative to the orientation of the molecule
and the light polarization axis pro-vides unprecedented insights into the
attosecond dynamics induced by extreme ultraviolet or X-ray one-photon
absorption, including the role of electronic correlation and continuum resonant
states. Here, we report completely resolved experimental and computational
angular depend-ence of single-photon ionization delays in NO molecules across a
shape resonance, relying on synchrotron radiation and time independent ab
initio calculations. The angle-dependent time delay variations of few hundreds
of attoseconds, resulting from the interference of the resonant and
non-resonant contributions to the dynamics of the ejected electron, are well
described using a multichannel Fano model where the resonance time delay is
angle-independent. Comparing these results with the same resonance computed in
e-NO+ scattering highlights the connection of photoionization delays with
Wigner scattering time delays.",2107.09915v3
2021-08-10,Resonant photoproduction of ultrarelativistic electron-positron pairs on a nucleus in strong monochromatic light field,"For complete development of quantum electrodynamics in the presence of a
strong external field, the proper understanding of resonant processes and all
their peculiarities is essential. We present our attempt to analytically
investigate the resonant case of laser-assisted electron-positron pair
photoproduction on a nucleus. Due to the presence of external field, the
intermediate virtual particle may become real, herewith the second order
process in the fine structure constant effectively reduces into the two
successive first order processes. All inherent kinematics features were
discussed in details and the resonant differential cross section was obtained.
We established that the resonant energies of produced particles ambiguously
depend on the positron (channel A) or electron (channel B) outgoing angle, and
the certain minimal amount of absorbed wave photons are required for resonance
to happen. Furthermore, the resonant cross section significantly exceeds the
corresponding one in the absence of the external field within the particular
kinematic regions and consequently, the considered process can be used qua a
marker for probing theoretical predictions of quantum electrodynamics with
strong background field.",2108.04955v1
2021-08-26,"A new expansion of planetary disturbing function and applications to interior, co-orbital and exterior resonances with planets","In this study, a new expansion of planetary disturbing function is developed
for describing the resonant dynamics of minor bodies with arbitrary
inclinations and semimajor axis ratios. In practice, the disturbing function is
expanded around circular orbits in the first step and then, in the second step,
the resulting mutual interaction between circular orbits is expanded around a
reference point. As usual, the resulting expansion is presented in the Fourier
series form, where the force amplitudes are dependent on the semimajor axis,
eccentricity and inclination and the harmonic arguments are linear combinations
of the mean longitude, longitude of pericenter and longitude of ascending node
of each mass. The resulting new expansion is valid for arbitrary inclinations
and semimajor axis ratios. In the case of mean motion resonant configuration,
the disturbing function can be easily averaged to produce the analytical
expansion of resonant disturbing function. Based on the analytical expansion,
the Hamiltonian model of mean motion resonances is formulated, and the
resulting analytical developments are applied to Jupiter's inner and co-orbital
resonances and Neptune's exterior resonances. Analytical expansion is validated
by comparing the analytical results with the associated numerical outcomes.",2108.11541v1
2021-09-05,Tuning nonequilibrium heat current and two-photon statistics via composite qubit-resonator interaction,"Quantum thermal transport and two-photon statistics serve as two
representative nonequilibrium features in circuit quantum electrodynamics
systems. Here, we investigate quantum heat flow and two-photon correlation
function at steady-state in a composite qubit-resonator model, where one qubit
shows both transverse and longitudinal couplings to a single-mode optical
resonator. With weak qubit-resonator interaction, we unravel two microscopic
transport pictures, i.e., cotunneling and cyclic heat exchange processes,
corresponding to transverse and longitudinal couplings respectively. At strong
qubit-resonator coupling, the heat current exhibits nonmonotonic behavior by
increasing qubit-resonator coupling strength, which tightly relies on the
scattering processes between the qubit and corresponding thermal bath.
Furthermore, the longitudinal coupling is preferred to enhance heat current in
strong qubit-resonator coupling regime. For two-photon correlation function, it
exhibits an antibunching-to-bunching transition, which is mainly dominated by
the modulation of energy gap between the first and second excited eigenstates.
Our results are expected to deepen the understanding of nonequilibrium thermal
transport and nonclassical photon radiation based on the circuit quantum
electrodynamics platform.",2109.02089v1
2021-09-06,Spectral flow inside essential spectrum II: resonance set and its structure,"This paper is a continuation of the study of spectral flow inside essential
spectrum initiated in \cite{AzSFIES}. Given a point $\lambda$ outside the
essential spectrum of a self-adjoint operator $H_0,$ the resonance set,
$\mathcal R(\lambda),$ is an analytic variety which consists of self-adjoint
relatively compact perturbations $H_0+V$ of $H_0,$ for which $\lambda$ is an
eigenvalue. One may ask for criteria for the vector $V$ to be tangent to the
resonance set. Such criteria were given in \cite{AzSFnRI}.
  In this paper we study similar criteria for the case of $\lambda$ inside the
essential spectrum of $H_0.$ For the case $\lambda \in \sigma_{ess}(H_0)$ the
resonance set is defined in terms of the well-known limiting absorption
principle. Among the results of this paper is that the resonance set contains
plenty of straight lines, moreover, given any regular relatively compact
perturbation $V$ there exists a finite rank self-adjoint operator, $\tilde V,$
such that the straight line $H_0 + \mathbb R(V-\tilde V)$ belongs to the
resonance set.
  Another result of this paper is that inside the essential spectrum there
exist plenty of transversal to the resonance set perturbations $V$ which have
order $\geq 2,$ in contrast to what happens outside the essential spectrum,
\cite{AzSFnRI}.",2109.02258v1
2021-10-04,"Mode coupling, bi-stability, and spectral broadening in buckled nanotube resonators","Bi-stable mechanical resonators play a significant role in various
applications, such as sensors, memory elements, and quantum computing. While
carbon nanotube (CNT) based resonators have been widely investigated as
promising nano electro-mechanical devices, a bi-stable CNT resonator has never
been demonstrated. Here, we report a new class of CNT resonators in which the
nanotube is buckled upward. We show that a small upward buckling yields record
electrical frequency tunability, whereas larger buckling can achieve
Euler-Bernoulli (EB) bi-stability, the smallest mechanical resonator with two
stable configurations to date. We believe that these recently discovered CNT
devices will open new avenues for realizing nano-sensors, mechanical memory
elements and parametric amplifiers. Furthermore, we present a three-dimensional
theoretical analysis revealing significant nonlinear coupling between the
in-plane and out-of-plane static and dynamic modes of motion, and a unique
three-dimensional EB snap-through transition. We utilize this coupling to
provide a conclusive explanation for the low quality factor in CNT resonators
at room temperature, key in understanding dissipation mechanisms at the nano
scale.",2110.01572v1
2021-10-11,Spin pumping at terahertz nutation resonances,"We investigate spin pumping current injected by the nutation resonances of a
ferromagnet or an antiferromagnet into an adjacent metal. Comparing the dc spin
pumping current between the normal precession and nutation resonances, we find
that the ratio of spin pumping current at the nutation resonance to the
precession resonance is more pronounced in antiferromagnets. We further show
that the spin pumping current injected by the nutation resonance is opposite in
sign as compared to the normal precession mode. This could offer a useful
experimental signature for identifying such nutation resonances. Analyzing the
nature of the nutational eigenmodes, we show that the sign change in spin
current is rooted in a reversal of the precession sense for the nutation
mode(s). Furthermore, the nutational modes in antiferromagnets are found to be
dominated by precession of one of the two sublattices only.",2110.05136v2
2021-10-12,Period Ratio Sculpting Near Second-Order Mean-Motion Resonances,"Second-order mean-motion resonances lead to an interesting phenomenon in the
sculpting of the period ratio distribution due to their shape and width in
period-ratio/eccentricity space. As the osculating periods librate in
resonance, the time-averaged period ratio approaches the exact
commensurability. The width of second-order resonances increases with
increasing eccentricity, and thus more eccentric systems have a stronger peak
at commensurability when averaged over sufficient time. The libration period is
short enough that this time-averaging behavior is expected to appear on the
timescale of the Kepler mission. Using N-body integrations of simulated planet
pairs near the 5:3 and 3:1 mean-motion resonances, we investigate the
eccentricity distribution consistent with the planet pairs observed by Kepler.
This analysis, an approach independent from previous studies, shows no
statistically significant peak at the 3:1 resonance and a small peak at the 5:3
resonance, placing an upper limit on the Rayleigh scale parameter, $\sigma$, of
the eccentricity of the observed Kepler planets at $\sigma=0.245$ (3:1) and
$\sigma=0.095$ (5:3) at 95% confidence, consistent with previous results from
other methods.",2110.06317v1
2021-10-21,Acoustic resonators: symmetry classification and multipolar content of the eigenmodes,"Acoustics recently became a versatile platform for discovering novel physical
effects and concepts at a relatively simple technological level. On this way,
single resonators and the structure of their resonant modes play a central role
and define the properties of complex acoustic systems such as acoustic
metamaterials, phononic crystals, and topological structures. In this paper, we
present a powerful method allowing a qualitative analysis of eigenmodes of
resonators in the linear monochromatic acoustic domain based on multipole
classification of eigenmodes. Using the apparatus of group theory, we explain
and predict the structure of the scattered field knowing only the symmetry
group of the resonator by connecting the multipolar content of incident and
scattered fields. Such an approach can be utilized for developing resonators
with predesigned properties avoiding time-consuming simulations. We have
performed full multipole symmetry classification for a number of resonators
geometries, and tightened it with scattering spectra profiles.",2110.11220v1
2021-10-29,Feshbach resonances and molecule formation in ultracold mixtures of Rb and Yb($^3$P) atoms,"We have investigated magnetically tunable Feshbach resonances in ultracold
collisions of Rb with Yb in its metastable $^3$P$_2$ and $^3$P$_0$ states,
using coupled-channel scattering and bound-state calculations. For the
$^3$P$_2$ state, we find sharp resonances when both atoms are in their lowest
Zeeman sublevels. However, these resonances are decayed by inelastic processes
that produce Yb atoms in $^3$P$_1$ and $^3$P$_0$ states. The molecules that
might be produced by magnetoassociation at the $^3$P$_2$ thresholds can decay
by similar pathways and would have lifetimes no more than a few microseconds.
For the $^3$P$_0$ state, by contrast, there are resonances that are promising
for magnetoassociation. There are resonances due to both rotating and
non-rotating molecular states that are significantly stronger than the
analogous resonances for Yb($^1$S). The ones due to rotating states are denser
in magnetic field; in contrast to Yb($^1$S), they exist even for bosonic
isotopes of Yb($^3$P$_0$).",2110.15906v2
2021-11-03,Helium surface fluctuations investigated with superconducting coplanar waveguide resonator,"Recent experiments on the coupling of the in-plane motional state of
electrons floating on the surface of liquid helium to a microwave resonator
have revealed the importance of helium surface fluctuations to the coherence of
this motion. Here we investigate these surface fluctuations by studying the
resonance properties of a superconducting coplanar waveguide (CPW) resonator
filled with superfluid helium, where a significant fraction of the resonator's
electromagnetic mode volume is coupled to the surface dynamics of the liquid.
We present preliminary results on real-time CPW resonator frequency shifts
driven by helium fluctuations, which are quantified via their power spectral
density and compared with measurements using a commercial accelerometer. We
find that a considerable contribution to the CPW resonator noise originates
from the mechanical vibrations of the helium surface generated by the pulse
tube (PT) cryocooler on the cryostat on which the experiments were performed.",2111.02350v2
2021-11-04,Active Tuning of Resonant Lattice Kerker Effect,"The Kerker effect has been generalized in nanophotonics and meta-optics, and
has recently been of great interest by relating to various fascinating
functionalities such as scattering management and perfect transmission,
reflection or absorption. One of the most interesting generalizations is the
resonant lattice Kerker effect in periodic nanostructures. However, its active
tuning has not been explored yet. Here, we report, for the first time, the
active control of the resonant lattice Kerker effect in periodic Ge2Se2Te5
nanodisks. By changing the crystalline fraction, we show that the electric
dipole lattice resonance (ED-LR), the magnetic dipole resonance (MDR), and thus
the resonant lattice Kerker effect are all red-shifted. We therefore realize
the transition from the ED-LR to the resonant lattice Kerker effect, which
enables multilevel tuning of reflection, transmission and absorption with
modulation depths above 86%. Taking advantage of the MDR redshifts, we also
observe broadband and multilevel tuning of transmission with modulation depth
of 87% over a broadband range of 588 nm. Our work establishes a new path for
designing high-performance active nanophotonic devices.",2111.02948v3
2021-11-10,Resonance contributions in $B^-\to K^+K^-π^-$ within the light-come sum rule approach,"In this work, we study the resonance contributions to the decay $B^-\to
K^+K^-\pi^-$, which is dominated by the scalar $f_0(980), K_0^*(1430)$, vector
$\rho(1450), \phi(1020), K^*(892)$ and tensor $f_2(1270)$ resonances. The
three-body decay is reduced to various quasi two-body decays, where the $B$
meson firstly decays into a resonance and a pion or a kaon, subsequently the
resonance decays into the other two final-state mesons. The quasi two-body
decays are calculated within the light-cone sum rule approach utilizing the
leading twist $B$ meson light-cone distribution amplitudes. Finally, the decay
branching fraction contribution from each resonance are calculated. Some of
them are compatible with experiment or previous theoretical works. Including
the effects of non-resonant and final-state interactions, we also evaluate the
total branching fraction.",2111.05647v1
2021-12-11,Rare decays of the $B_s-$meson into four charged leptons in the framework of the Standard Model,"In the framework of the Standard Model we present new theoretical predictions
for the branching ratios, double and single differential distributions and
forward -- backward leptonic asymmetries for the $\bar B_s \to \mu^+ \mu^- e^+
e^-$ decay. In our consideration we take into account the $\phi(1020)$ --
resonance contribution; the main contributions of four charmonium resonances :
$\psi(3770)$, $\psi(4040)$, $\psi(4160)$ and $\psi(4415)$; $u\bar{u}$ --
resonant contribution from $\rho(770)$ and $\omega(782)$; tails contributions
from $J/\psi$ and $\psi(2S)$ resonances; non -- resonant contribution of the
$b\,\bar{b}$ - pairs, bremsstrahlung and the contribution of the weak
annihilation. We provide the prediction for the branching ratio of $\bar B_s
\to \mu^+ \mu^- e^+ e^-$ decay with and without the $\phi(1020)$ -- resonance
contribution. We use the model of vector meson dominance (VMD) for calculation
of resonances contributions and take into account all substantive terms in
$\bar B_s \to \mu^+ \mu^- e^+ e^-$ amplitude that was not considered in the
previously papers.",2112.06093v1
2021-12-22,Fourier-Engineered Plasmonic Lattice Resonances,"Resonances in optical systems are useful for many applications, such as
frequency comb generation, optical filtering, and biosensing. However, many of
these applications are difficult to implement in optical metasurfaces because
traditional approaches for designing multi-resonant nanostructures require
significant computational and fabrication efforts. To address this challenge,
we introduce the concept of Fourier lattice resonances (FLRs) in which multiple
desired resonances can be chosen a priori and used to dictate the metasurface
design. Because each resonance is supported by a distinct surface lattice mode,
each can have a high quality factor. Here, we experimentally demonstrate
several metasurfaces with arbitrarily placed resonances (e.g., at 1310 and 1550
nm) and Q-factors as high as 800 in a plasmonic platform. This flexible
procedure requires only the computation of a single Fourier transform for its
design, and is based on standard lithographic fabrication methods, allowing one
to design and fabricate a metasurface to fit any specific, optical-cavity-based
application. This work represents an important milestone towards the complete
control over the transmission spectrum of a metasurface.",2112.11625v1
2022-01-30,Confirming the 3:2 Resonance Chain of K2-138,"The study of orbital resonances allows for the constraint of planetary
properties of compact systems. K2-138 is an early K-type star with six planets,
five of which have been proposed to be in the longest chain of 3:2 mean motion
resonances. To observe and potentially verify the resonant behavior of K2-138's
planets, we run N-body simulations using previously measured parameters.
Through our analysis, we find that 99.2% of our simulations result in a chain
of 3:2 resonances, although only 11% of them show a five-planet resonance
chain. We find we are able to use resonances to constrain the orbital periods
and masses of the planets. We explore the possibility of this system forming in
situ and through disk migration, and investigate the potential compositions of
each planet using a planet structure code.",2201.12687v1
2022-02-07,Symmetry-breaking induced frequency combs in graphene resonators,"Nonlinearities are inherent to the dynamics of two-dimensional materials.
Phenomena like intermodal coupling already arise at amplitudes of only a few
nanometers, and a range of unexplored effects still awaits to be harnessed.
Here, we demonstrate a route for generating mechanical frequency combs in
graphene resonators undergoing symmetry-breaking forces. We use electrostatic
force to break the membrane's out-of-plane symmetry and tune its resonance
frequency towards a two-to-one internal resonance, thus achieving strong
coupling between two of its mechanical modes. When increasing the drive level,
we observe splitting of the fundamental resonance peak, followed by the
emergence of a frequency comb regime. We attribute the observed physics to a
non-symmetric restoring potential, and show that the frequency comb regime is
mediated by a Neimark bifurcation of the periodic solution. These results
demonstrate that mechanical frequency combs and chaotic dynamics in 2D material
resonators can emerge near internal resonances due to symmetry-breaking.",2202.03318v1
2022-02-07,Broadband Resonance-Enhanced Frequency Generation by Four-Wave Mixing in a Silicon Floquet Topological Photonic Insulator,"Floquet topological photonic insulators, whose light transport properties are
dictated by the periodic drive sequence of the lattice, provide more
flexibility for controlling and trapping light than undriven topological
insulators, which can enable novel nonlinear optics applications in topological
photonics. Here, we employ a novel resonance effect called Floquet Defect Mode
Resonance in a 2D silicon Floquet microring lattice to demonstrate
resonance-enhanced frequency generation by four-wave mixing of Floquet bulk
modes in the presence of Kerr nonlinearity. The compact, cavity-less resonance
mode, induced through a periodic perturbation of the lattice drive sequence,
has the largest reported Q-factor for a topological resonator of ~10^5 with low
group velocity dispersion, which enables efficient broadband frequency
generation over several Floquet-Brillouin zones of the Floquet topological
insulator. We achieved wavelength conversion over 10.1 nm spectral range with
an average enhancement of 12.5 dB in the conversion efficiency due to the
Floquet Defect Mode Resonance. Our work could lead to robust light sources
generated directly on a topologically-protected photonic platform.",2202.03552v1
2022-02-21,Two-dimensional Helmholtz resonator arrays. Part II. Matched asymptotic expansions for specially-scaled resonators,"We present a solution method which combines the method of matched asymptotics
with the method of multipole expansions to determine the band structure of
cylindrical Helmholtz resonators arrays in two dimensions. The resonator
geometry is considered in the limit as the wall thickness becomes very large
compared with the aperture width (the specially-scaled limit). In this regime,
the existing treatment in Part I, with updated parameters, is found to return
spurious spectral behaviour. We derive a regularised system which overcomes
this issue and also derive compact asymptotic descriptions for the
low-frequency dispersion equation in this setting. In the specially-scaled
limit, our asymptotic dispersion equation not only recovers the first band
surface but also extends to high, but still subwavelength, frequencies. A
homogenisation treatment is outlined for describing the effective bulk modulus
and effective density tensor of the resonator array for all wall thicknesses.
We demonstrate that specially-scaled resonators are able to achieve
exceptionally low Helmholtz resonant frequencies, and present closed-form
expressions for determining these explicitly. We anticipate that the analytical
expressions and the formulation outlined here may prove useful in industrial
and other applications.",2202.09943v1
2022-03-01,Impact of the interference between the resonance and continuum amplitudes on vector quarkonia decay branching fraction measurements,"The measurement of the branching fraction of a heavy quarkonium decaying into
light hadronic final state at $e^+e^-$ colliders is revisited. In $e^+e^-$
annihilation experiments, background contributions from the continuum amplitude
and its interference with the resonance amplitude are irreducible. These
effects become more and more significant as the precision of experimental
measurements improves. While the former can be easily subtracted with data
taken off the resonance peak, the latter depends on the relative size and phase
between the resonance and continuum amplitudes. Two ratios are defined to
estimate the size of these effects, $r_{R}^{f}$ for the ratio of the
contribution of the interference term to the resonance term and $r_{c}^{f}$ for
that to the continuum term. We find that $r_{R}^{f}$ could be as large as a few
percent for narrow resonances, and both $r_{R}^{f}$ and $r_{c}^{f}$ could be
large for broad resonances. This indicates that the interference effect is
crucial for the measurements of the branching fractions aiming at the percent
level or better precision and needs to be measured or estimated properly.",2203.00244v2
2022-03-14,Complex Scalar Singlet Model Benchmarks for Snowmass,"In this contribution to Snowmass 2021, we present benchmark parameters for
the general complex scalar singlet model. The complex scalar singlet extension
has three massive scalar states with interesting decay chains which will depend
on the exact mass hierarchy of the system. We find maximum branching ratios for
resonant double Standard Model-like Higgs production, resonant production of a
Standard Model-like Higgs and a new scalar, and double resonant new scalar
production. These branching ratios are between 0.7 and 1. This is particularly
interesting because instead of direct production, the main production of a new
scalar resonance may be from the $s$-channel production and decay of another
scalar resonance. That is, it is still possible for discovery of new scalar
resonances to be from the cascade of one resonance to another. We choose our
benchmark points to have to have a large range of signatures: multi-$b$
production, multi-$W$ and $Z$ production, and multi-125 GeV SM-like Higgs
production. These benchmark points can provide various spectacular signatures
that are consistent with current experimental and theoretical bounds. This is a
summary of results in Ref. [1].",2203.07455v1
2022-04-01,Terahertz sensing of highly absorptive water-methanol mixtures with multiple resonances in metamaterials,"Ultrasensitive terahertz sensing of highly absorptive aqueous solutions
remains challenging due to strong absorption of water in the terahertz regime.
Here, we experimentally demonstrate a cost-effective metamaterial-based sensor
integrated with terahertz time-domain spectroscopy for highly absorptive
water-methanol mixture sensing. This metamaterial has simple asymmetric wire
structures that support multiple resonances including a fundamental Fano
resonance and higher order dipolar resonance in the terahertz regime. Both the
resonance modes have strong intensity in the transmission spectra which we
exploit for detection of the highly absorptive water-methanol mixtures. The
experimentally characterized sensitivities of the Fano and dipole resonances
for the water-methanol mixtures are found to be 160 and 305 GHz/RIU,
respectively. This method provides a route for readily available
metamaterial-assisted terahertz spectroscopy for ultrasensitive sensing of
highly absorptive chemical and biochemical materials with multiple resonances
and high accuracy.",2204.00690v1
2022-05-06,Complementary-Switchable Dual-Mode SHF Scandium-Aluminum Nitride BAW Resonator,"This article presents a bulk acoustic wave (BAW) resonator with complementary
switchable operation in the first and second thickness extensional modes (TE1
and TE2) at 7.04 and 13.4 GHz. Two ferroelectric scandium aluminum nitride
(Sc0.28Al0.72N) layers are alternatively stacked with three molybdenum
electrodes, creating a laminated BAW resonator with independent switchability
of polarization in constituent transducers. This enables intrinsic
switchability of the resonator in TE1 and TE2 modes, when the ferroelectric
Sc0.28Al0.72N layers are poled in the same or opposite directions,
respectively. A generalized analytical proof of complementary switchable
operation, extended to laminated BAW resonators consisting of arbitrary number
of ScxAl1-xN layers, is presented. For the demonstrated prototype,
electromechanical coupling coefficients ( k2t ) of 10.1% and 10.7%, and quality
factors ( Q ) of 115 and 151, are measured for TE1 and TE2 modes, respectively,
when the resonator is configured in the corresponding operation states. Besides
showing intrinsically configurable operation in super-high-frequency regime
with high k2t and Q , a laminated Sc0.28Al0.72N BAW resonator exhibits
repeatable operation under switching cycles.",2205.03446v2
2022-05-16,Web of resonances and possible path of evolution of the small Uranian satellites,"Satellite systems around giant planets are immersed in a region of complex
resonant configurations. Understanding the role of satellite resonances
contributes to comprehending the dynamical processes in planetary formation and
posterior evolution. Our main goal is to analyse the resonant structure of
small moons around Uranus and propose different scenarios able to describe the
current configuration of these satellites. We focus our study on the external
members of the regular satellites interior to Miranda, namely Rosalind, Cupid,
Belinda, Perdita, Puck, and Mab, respectively. We use N-body integrations to
perform dynamical maps to analyse their dynamics and proximity to two-body and
three-body mean-motion resonances (MMR). We found a complicated web of
low-order resonances amongst them. Employing analytical prescriptions, we
analysed the evolution by gas drag and type-I migration in a circumplanetary
disc (CPD) to explain different possible histories for these moons. We also
model the tidal evolution of these satellites using some crude approximations
and found possible paths that could lead to MMRs crossing between pairs of
moons. Finally, our simulations show that each mechanism can generate
significant satellite radial drift leading to possible resonant capture,
depending on the distances and sizes.",2205.07542v1
2022-05-18,Spatial resolution of omni-resonant imaging,"Omni-resonance refers to the broadening of the spectral transmission through
a planar cavity, not by changing the cavity structure, but by judiciously
preconditioning the incident optical field. As such, broadband imaging can be
performed through such a cavity with all the wavelengths simultaneously
resonating. We examine here the spatial resolution of omni-resonant imaging and
find that the spectral linewidth of the cavity resonance determines the spatial
resolution. Surprisingly, the spatial resolution improves at longer wavelengths
because of the negative angular dispersion intrinsic to Fabry-Perot resonances,
in contrast to conventional diffraction-limited optical imaging systems where
the spatial resolution improves at shorter wavelengths. These results are
important for applications ranging from transparent solar windows to nonlinear
resonant image processing.",2205.09158v2
2022-05-27,Mall bundles and flat connections on Hopf manifolds,"A Mall bundle on a Hopf manifold H is a holomorphic vector bundle whose
pullback to the universal cover of H is trivial. We define resonant and
non-resonant Mall bundles, generalizing the notion of the resonance in ODE, and
prove that a non-resonant Mall bundle always admits a flat holomorphic
connection. We use this observation to prove a version of Poincare-Dulac
linearization theorem, showing that any non-resonant invertible holomorphic
contraction of a complex space is linear in appropriate holomorphic
coordinates. We define the notion of resonance in Hopf manifolds, and show that
all non-resonant Hopf manifolds are linear; previously, this result was
obtained by Kodaira using the Poincare-Dulac theorem.",2205.14062v1
2022-06-13,On-chip frequency tuning of fast resonant MEMS scanner,"The development and characterisation of a piezoelectric actuated
high-frequency MEMS scanning mirror with on-chip frequency tuning capability is
reported. The resonant scanner operates at frequencies in excess of 140 kHz,
generating scan angles of 10{\deg} and 6{\deg} for two orthogonal movement
modes with 40 V actuation. On-chip frequency tuning is achieved through
electrothermal actuators fabricated adjacent to the mirror main suspension. The
electrothermal actuators produce a global and local temperature increase which
changes the suspension stiffness and therefore the resonant frequency. A
resonance frequency tuning range of up to 5.5 kHz is achieved, with tuning
dominant on only one of the two orthogonal scan movement modes. This opens the
possibility for precise tuning of a 2D Lissajous scan pattern using a single
resonant MEMS scanner with dual orthogonal resonant modes producing full frame
update rates up to 20 kHz while retaining the full angular range of both
resonant movement modes",2206.06785v1
2022-08-12,Observation of magnetic Feshbach resonances between Cs and ${}^{173}$Yb,"We report the first observation of magnetic Feshbach resonances between
${}^{173}$Yb and $^{133}$Cs. In a mixture of Cs atoms prepared in the $(f=3,
m_f=3)$ state and unpolarized fermionic ${}^{173}$Yb we observe resonant atom
loss due to two sets of magnetic Feshbach resonances around 622~G and 702~G.
Resonances for individual Yb nuclear spin components $m_{i,\mathrm{Yb}}$ are
split by its interaction with the Cs electronic spin, which also provides the
main coupling mechanism for the observed resonances. The observed splittings
and relative resonance strengths are in good agreement with theoretical
predictions from coupled-channel calculations.",2208.06291v1
2022-08-15,$S$-wave fully charmed tetraquark resonant states,"We calculate the mass spectrum of the $S$-wave fully-charmed tetraquark
resonant states $cc\bar c\bar c $ in the nonrelativistic quark model, which
successfully describes the charmonium spectrum. The four-body system is solved
with the Gaussian expansion method. The complex scaling technique is used to
identify the genuine resonances. With the nonrelativistic quark model, our
results show the existence of two $cc\bar c\bar c$ resonances in each of the
$J^{PC}=$ $0^{++}$, $1^{+-}$ and $2^{++}$ sectors, respectively. In the
$S$-wave sector, no resonance is found at the energy region of the $X(6200)$
and $X(6600)$ states. The lower $0^{++}$ and $2^{++}$ resonances are located
around $100$ MeV higher than the $X(6900)$ state observed in experiments but
have the decay widths consistent with the experiment. The higher $0^{++}$ and
$2^{++}$ resonances are found at around $7.2$ GeV with the widths of $60.6$ MeV
and $91.2$ MeV, respectively, and they may be good candidates for the $X(7200)$
state.",2208.07292v2
2022-09-01,Multiplexing-based control of stochastic resonance,"We show that multiplexing allows to control noise-induced dynamics of
multilayer networks in the regime of stochastic resonance. We illustrate this
effect on an example of two- and multi-layer networks of bistable overdamped
oscillators. In particular, we demonstrate that multiplexing suppresses the
effect of stochastic resonance, if the periodic forcing is present in only one
layer. In contrast, the multiplexing allows to enhance the stochastic
resonance, if the periodic forcing and noise are present in all the interacting
layers. In such a case the impact of multiplexing has a resonant character: the
most pronounced effect of stochastic resonance is achieved for an appropriate
intermediate value of coupling strength between the layers. Moreover,
multiplexing-induced enhancement of the stochastic resonance can become more
pronounced for increasing number of coupled layers. To visualize the revealed
phenomena, we use the evolution of the dependence of the signal-to-noise ratio
on the noise intensity for varying strength of coupling between the layers.",2209.00433v2
2022-09-03,Understanding the Quality Factor of Mass-Loaded Tensioned Resonators,"Mechanical resonators featuring large tensile stress have enabled a range of
experiments in quantum optomechanics and novel sensing. Many sensing
applications require functionalizing tensioned resonators by appending
additional mass to them. However, this may dramatically change the resonator
mode quality factor, and hence its sensitivity. In this work, we investigate
the effect of the crossover from no mass load to a large mass load on the mode
shape and quality factor of a tensioned resonator. We show through an
analytical model and finite element analysis that as the load mass increases,
surprisingly, the resonator mode shape becomes independent of the exact load
mass, and therefore, its quality factor saturates. We validate this saturation
effect experimentally by measuring the quality factor of a silicon nitride
trampoline resonator while varying the load mass in a controlled manner.",2209.01488v1
2022-09-09,Diverse coherence-resonance chimeras in coupled type-I excitable systems,"Coherence-resonance chimera was discovered in [Phys. Rev. Lett. 117, 014102
(2016)], which combines the effect of coherence resonance and classical
chimeras in the presence of noise in a network of type-II excitable systems.
However, the same in a network of type-I excitable units has not been observed
yet. In this paper, for the first time, we report the occurrence of
coherence-resonance chimera in coupled type-I excitable systems. We consider a
paradigmatic model of type-I excitability, namely the saddle-node infinite
period model and show that the coherence-resonance chimera appears over an
optimum range of noise intensity. Moreover, we discover a unique chimera
pattern that is a mixture of classical chimera and the coherence-resonance
chimera. We support our results using quantitative measures and map them in
parameter space. This study reveals that the coherence-resonance chimera is a
general chimera pattern and thus it deepens our understanding of role of noise
in coupled excitable systems.",2209.04233v2
2022-09-15,Superfluid $^4$He as a rigorous test bench for different damping models in nanoelectromechanical resonators,"We have used nanoelectromechanical resonators to probe superfluid $^4$He at
different temperature regimes, spanning over four orders of magnitude in
damping. These regimes are characterized by the mechanisms which provide the
dominant contributions to damping and the shift of the resonance frequency:
tunneling two level systems at the lowest temperatures, ballistic phonons and
rotons at few hundred mK, and laminar drag in the two-fluid regime below the
superfluid transition temperature as well as in the normal fluid. Immersing the
nanoelectromechanical resonators in fluid increases their effective mass
substantially, decreasing their resonance frequency. Dissipationless superflow
gives rise to a unique possibility to dramatically change the mechanical
resonance frequency in situ, allowing rigorous tests on different damping
models in mechanical resonators. We apply this method to characterize tunneling
two-level system losses and magnetomotive damping in the devices.",2209.07229v2
2022-10-01,Singular states of resonant nanophotonic lattices,"Fundamental effects in nanophotonic resonance systems focused on singular
states and their properties are presented. Strongly related to lattice geometry
and material composition, there appear resonant bright channels and
non-resonant dark channels in the spectra. The bright state corresponds to high
reflectivity guided-mode resonance (GMR) whereas the dark channel represents a
bound state in the continuum (BIC). Even in simple systems, singular states
with tunable bandwidth appear as isolated spectral lines that are widely
separated from other resonance features. Under moderate lattice modulation,
there ensues leaky-band metamorphosis, merging modal bands and resulting in
offset dark states and reflective BICs along with transmissive BICs within a
high-reflectance wideband. Rytov-type effective medium theory (EMT) is shown to
be a powerful means to describe, formulate, and understand the collective
GMR/BIC fundamentals in resonant photonic systems. Particularly, the discarded
Rytov analytical solution for asymmetric fields is shown here to predict the
dark BIC states essentially exactly for considerable modulation levels. The
propagation constant of an equivalent EMT homogeneous film provides a
quantitative evaluation of the eminent, oft-cited embedded BIC eigenvalue. The
work concludes with experimental verification of key effects.",2210.00375v1
2022-10-17,Transduction of single nanomechanical pillar resonators by scattering of surface acoustic waves,"One of the challenges of nanoelectromechanical systems (NEMS) is the
effective transduction of the tiny resonators. Vertical structures, such as
nanomechanical pillar resonators, which are exploited in a wide range of
fields, such as optomechanics, acoustic metamaterials, and nanomechanical
sensing, are particularly challenging to transduce. Existing electromechanical
transduction methods are ill-suited as they complicate the pillars' fabrication
process, put constraints on the pillars' material, and do not enable a
transduction of freestanding pillars. Here, we present an electromechanical
transduction method for single nanomechanical pillar resonators based on
surface acoustic waves (SAWs). We demonstrate the transduction of freestanding
nanomechanical platinum-carbon pillars in the first-order bending and
compression mode. Since the principle of the transduction method is based on
resonant scattering of a SAW by a nanomechanical resonator, our transduction
method is independent of the pillar's material and not limited to pillar-shaped
geometries. It represents a general method to transduce vertical mechanical
resonators with nanoscale lateral dimensions.",2210.09069v2
2022-10-28,Sliding nanomechanical resonators,"The motion of a vibrating object is determined by the way it is held. This
simple observation has long inspired string instrument makers to create new
sounds by devising elegant string clamping mechanisms, whereby the distance
between the clamping points is modulated as the string vibrates. At the
nanoscale, the simplest way to emulate this principle would be to controllably
make nanoresonators slide across their clamping points, which would effectively
modulate their vibrating length. Here, we report measurements of flexural
vibrations in nanomechanical resonators that reveal such a sliding motion.
Surprisingly, the resonant frequency of vibrations draws a loop as a tuning
gate voltage is cycled. This behavior indicates that sliding is accompanied by
a delayed frequency response of the resonators, making their dynamics richer
than that of resonators with fixed clamping points. Our work elucidates the
dynamics of nanomechanical resonators with unconventional boundary conditions,
and offers opportunities for studying friction at the nanoscale from resonant
frequency measurements.",2210.15862v1
2022-11-30,Dynamics and Origins of the Near-Resonant Kepler Planets,"Short-period super-Earths and mini-Neptunes encircle more than $\sim50\%$ of
Sun-like stars and are relatively amenable to direct observational
characterization. Despite this, environments in which these planets accrete are
difficult to probe directly. Nevertheless, pairs of planets that are close to
orbital resonances provide a unique window into the inner regions of
protoplanetary disks, as they preserve the conditions of their formation, as
well as the early evolution of their orbital architectures. In this work, we
present a novel approach toward quantifying transit timing variations within
multi-planetary systems and examine the near-resonant dynamics of over 100
planet pairs detected by \textit{Kepler}. Using an integrable model for
first-order resonances, we find a clear transition from libration to
circulation of the resonant angle at a period ratio of $\approx 0.6\%$ wide of
exact resonance. The orbital properties of these systems indicate that they
systematically lie far away from the resonant forced equilibrium. Cumulatively
our modeling indicates that while orbital architectures shaped by strong disk
damping or tidal dissipation are inconsistent with observations, a scenario
where stochastic stirring by turbulent eddies augments the dissipative effects
of protoplanetary disks reproduces several features of the data.",2211.16725v2
2022-12-27,Omni-resonant imaging across the visible,"Resonant field enhancement in optical cavities is provided over only narrow
linewidths and for specific spatial modes. Consequently, spectrally restrictive
planar Fabry-P{\'e}rot cavities have not contributed to date to white-light
imaging, which necessitates a highly multimoded broadband field to satisfy the
resonance condition. Here we show that introducing judicious angular-dispersion
circumvents the fundamental trade-off between cavity linewidth and finesse in a
Fabry-P{\'e}rot cavity by exciting a 130-nm-bandwidth achromatic resonance
across the visible spectrum, which far exceeds the finesse-limited linewidth
(0.5~nm), and even exceeds the free spectral range (45~nm). This omni-resonant
configuration enables broadband color-imaging over a 100-nm-bandwidth in the
visible with minimal spherical and chromatic aberrations. We demonstrate
omni-resonant imaging using coherent and incoherent light, and spatially
extended and localized fields comprising stationary and moving objects. This
work paves the way to harnessing broadband resonant enhancements for spatially
structured fields, as needed for example in solar windows.",2212.13351v2
2023-01-20,Generation of photon pairs by spontaneous four-wave mixing in linearly uncoupled resonators,"We present a detailed study of the generation of photon pairs by spontaneous
four-wave mixing in a structure composed of two linearly uncoupled resonators,
where energy can be transferred from one resonator to another only through a
nonlinear interaction. Specifically, we consider the case of two
racetrack-shaped resonators connected by a coupler designed to guarantee that
the resonance comb of each resonator can be tuned independently, and to allow
the nonlinear interaction between modes that belong to different combs. We show
that such a coupler can be realized in at least two ways: a directional coupler
or a Mach-Zehnder interferometer. For these two scenarios, we derive analytic
expressions for the pair generation rate via single-pump spontaneous four-wave
mixing, and compare these results with that achievable in a single ring
resonator.",2301.08603v1
2023-01-24,Predissociation dynamics of negative ion resonances of H$_2$ near 12 eV and 14.5 eV using velocity slice imaging technique,"Dissociative electron attachment (DEA) is an important tool for investigating
negative ion resonances. We have studied the negative ion resonances of H2 at
10 eV and 14 eV using the improved velocity slice imaging technique. We
obtained modulations in the kinetic energy spectrum of H$^-$ ions obtained at
12 eV and 14.5 eV electron energy, consistent with the earlier reported
vibrational state contributions from the higher lying bound resonances. We show
that structures obtained at 12 eV are due to predissociation of the
$C^2{\Sigma}_g^+$ resonance consistent with the current understanding. However,
based on our angular distribution measurements, we propose that the structures
obtained at 14.4 eV are due to predissociation of bound resonance of
$^2{\Sigma}_g^+$ symmetry as against ${\delta}_g$ that was proposed earlier. We
also report that the bound $^2{\Sigma}_g^+$ resonance contributes to the
observed inversion symmetry breaking near 14 eV.",2301.09927v1
2023-02-13,Broadband generation of quasi bound-state-in-continuum modes using subwavelength truncated cone resonators,"Allowing a high quality factor (Q-factor) to a sub-wavelength dielectric
resonator, quasi-bound states in the continuum (Q-BIC) has gained much
interest. However, the Q-BIC resonance condition is too sensitive to the
geometry of the resonator and its practical broadband generation on a
single-wafer platform has been limited. Here, we present that employing the
base angle as a structural degree of freedom, the truncated nano-cone resonator
supports the Q-BIC resonance with a high Q-factor of >150 over a wide
wavelength range of >100 nm. We expect our approach will boost the utilization
of the Q-BIC resonance for various applications requiring broadband spectral
tuning.",2302.06121v3
2023-02-22,Revisit of tensor-meson nonet in resonance chiral theory,"We study the properties of the lowest multiplet of light-flavor tensor meson
resonances, i.e. $f_2(1270)$, $a_2(1320)$, $K_2^*(1430)$, and $f_2'(1525)$,
within the resonance chiral theory approach. The higher-order resonance chiral
operators, including the light-quark mass and $1/N_C$ corrections, are
simultaneously incorporated in our study. The use of resonance chiral
expressions allows us to analyze not only the relevant experimental data but
also in the meantime the lattice results at unphysical quark masses, including
the masses of the lowest multiplet of tensor resonances and their decay widths
into two pseudoscalar mesons. In addition, the radiative decays of the tensor
resonances into one photon plus one pseudoscalar meson and two photons are also
studied.",2302.11316v2
2023-02-28,Tunable Feshbach resonances in collisions of ultracold molecules in $^2Σ$ states with alkali-metal atoms,"We consider the magnetically tunable Feshbach resonances that may exist in
ultracold mixtures of molecules in $^2\Sigma$ states and alkali-metal atoms. We
focus on Rb+CaF as a prototype system. There are likely to be Feshbach
resonances analogous to those between pairs of alkali-metal atoms. We
investigate the patterns of near-threshold states and the resonances that they
cause, using coupled-channel calculations of the bound states and low-energy
scattering on model interaction potentials. We explore the dependence of the
properties on as-yet-unknown potential parameters. There is a high probability
that resonances will exist at magnetic fields below 1000 G, and that these will
be broad enough to control collisions and form triatomic molecules by
magnetoassociation. We consider the effect of CaF rotation and potential
anisotropy, and conclude that they may produce additional resonances but should
not affect the existence of rotation-free resonances.",2302.14687v2
2023-03-20,Ab initio calculation of the spectrum of Feshbach resonances in NaLi + Na collisions,"We present a combined experimental and theoretical study of the spectrum of
magnetically tunable Feshbach resonances in NaLi $(a^3\Sigma^+)$ $+$ Na
collisions. In the accompanying paper, we observe experimentally 8 and 17
resonances occur between $B=0$ and $1400$~G in upper and lower spin-stretched
states, respectively. Here, we perform ab initio calculations of the NaLi $+$
Na interaction potential and describe in detail the coupled-channel scattering
calculations of the Feshbach resonance spectrum. The positions of the
resonances cannot be predicted with realistic uncertainty in the
state-of-the-art ab initio potential, but our calculations yield a typical
number of resonances that is in near-quantitative agreement with experiment. We
show that the main coupling mechanism results from spin-rotation and spin-spin
couplings in combination with the anisotropic atom-molecule interaction. The
calculations furthermore explain the qualitative difference between the numbers
of resonances in either spin state.",2303.10940v2
2023-03-15,Power-to-Frequency Conversion in Cryogenic Sapphire Resonators,"We studied how the cryogenic sapphire resonator responds to fast variations
of the dissipated microwave power. The experiments were carried out with
sapphire resonators cooled to 6 K at frequencies around 11 GHz. We found that
the power-to-frequency conversion of the resonator depends on Fourier frequency
as the transfer function of the 1st-order low-pass filter with corner frequency
close to the resonator loaded half-bandwidth. Having measured the
power-to-frequency conversion of the cryogenic sapphire resonator, we predicted
the phase noise of the microwave oscillator based on such resonator.",2303.15363v2
2023-04-03,A multichannel hyperspherical model for Efimov physics with van der Waals interactions controlled by a Feshbach resonance,"Here we present a four-channel model that incorporates a magnetically tunable
Feshbach resonance in a system of three atoms that interact via pairwise van
der Waals interactions. Our method is designed to model recent experiments
where the tunability of the scattering length has been used to study three-body
Efimov states, which appear in the limit of a diverging two-body scattering
length. Using this model, we calculate three-body adiabatic and effective
potential curves and study how the strength (or width) of the Feshbach
resonance affects the three-body potential that is connected to the Efimov
effect. We find that the position of the repulsive barrier, which has been used
to explain the so-called van der Waals universality in broad resonances, is
slightly shifted as the narrow resonance limit is approached and that this
shift is correlated to the appearance of two avoided crossings in the adiabatic
energy landscape. More importantly, the attractive well is markedly shifted
upward in energy and is extremely shallow for the narrowest resonance. We argue
that this behavior is connected to the breakdown of van der Waals universality
for weak (narrow) resonances.",2304.00878v1
2023-04-03,Invariant-mass spectroscopy in projectile fragmentation reactions,"The fragmentation of a projectile into a number of pieces can lead to the
creation of many resonances in different nuclei. We discuss application of the
invariant-mass method to the products from such reactions to find some of the
most exotic resonances located furthest beyond the proton drip line. We show
examples from fragmentation of a fast $^{13}$O beam including the production of
the newly identified $^9$N resonance. In extracting resonance parameters from
invariant-mass spectra, accurate estimates of the background from non-resonant
prompt protons are needed. This is especially important in determining the
widths of wide resonances typically found at the edge of the chart of nuclides.
An event-mixing recipe, where the mixed events have reduced weighting for the
smaller invariant-masses, is proposed to describe this background. The
weighting is based on the measured correlations of heavier hydrogen isotopes
with the resonances or the projectile residues.",2304.01124v1
2023-04-11,Lattice design and experimental studies of nonlinear resonance at the Cornell Electron Storage Ring,"The predominant source of nonlinearity in most existing accelerators are
sextupoles, which introduce nonlinear resonances. When the horizontal tune of
an accelerator is near such a resonance line ($n\nu_x$), stable fixed points
(SFPs) may appear in the horizontal phase space to form a second closed orbit
different from the ""zero"" closed orbit. The stable islands in phase space
surrounding the SFPs are also referred as transverse resonance island ""buckets""
(TRIBs). However, the TRIBs are not always present near a resonance line in a
storage ring. Necessary conditions for TRIBs formation will be discussed in
this paper. A 6-GeV lattice with the horizontal tune near a 3rd-order resonance
line at $3\nu_{x}$=50 is then designed for the Cornell Electron Storage Ring
(CESR). After loading this lattice into CESR, the TRIBs are observed while
adjusting the horizontal tune near the 3rd-order resonance, consistent with
particle tracking simulations. TRIBs rotation in the horizontal phase space are
also experimentally demonstrated with adjustment of a sextupole knob. These
results are in good agreement with the theoretical calculation.",2304.05250v2
2023-04-24,Dissociation dynamics in low energy electron attachment to nitrogen dioxide,"Complete dissociation dynamics of low energy electron attachment to nitrogen
dioxide around 8.5 eV resonance has been studied using a velocity map imaging
(VMI) spectrometer. Besides the three prominent resonant peaks at around 1.4
eV, 3.1 eV, and 8.5 eV, we have found an additional small resonance at the
higher energy tail of the 8.5 eV resonance. We have collected the momentum
distribution data of O$^-$ ions at different incident electron energies around
the 8.5 eV resonance along with the smaller additional resonant peak. A
theoretical analysis of these resonances with the momentum imaging experimental
data on dissociative electron attachment to nitrogen dioxide in the gas phase
is used to provide a detailed picture of the molecular dissociation process.",2304.11899v1
2023-04-29,Shape resonance induced electron attachment to Cytosine: The effect of aqueous media,"We have investigated the impact of microsolvation on the shape resonance
states of nucleobases, taking cytosine as a case study. To characterize the
resonance position and decay width of the metastable states, we employed the
newly developed DLPNO-based EA-EOMCCSD method in conjunction with resonance via
Pad\'e approximation. Our calculations show that the presence of water
molecules causes a red shift in the resonance position and an increase in the
lifetime for all three resonance states. Furthermore, the lowest resonance
state in isolated cytosine was converted to a bound state in the presence of an
aqueous environment. The calculated results are extremely sensitive to the
basis set used for the calculations.",2305.00012v2
2023-05-04,Quasilinear theory of Brillouin resonances in rotating magnetized plasmas,"Both spin and orbital angular momentum can be exchanged between a rotating
wave and a rotating magnetized plasma. Through resonances the spin and orbital
angular momentum of the wave can be coupled to both the cyclotron rotation and
the drift rotation of the particles. It is however shown that the Landau and
cyclotron resonance conditions which classically describe resonant
energy-momentum exchange between waves and particles are no longer valid in a
rotating magnetized plasma column. In this case a new resonance condition which
involves a resonant matching between the wave frequency, the cyclotron
frequency modified by inertial effects and the harmonics of the guiding center
rotation is identified. A new quasilinear equation describing orbital and spin
angular momentum exchanges through these new Brillouin resonances is then
derived, and used to expose the wave driven radial current responsible for
angular momentum absorption.",2305.02671v1
2023-07-08,Synthesis of resonant modes in electromagnetics,"Resonant modes determine the response of electromagnetic devices, including
dielectric and plasmonic resonators. Relying on the degrees of freedom that
metamaterials provide, this contribution shows how to design, at will, the
resonant modes of a dielectric object placed in an unbounded space.
Specifically, the proposed method returns in analytical form the spatial
distribution of the dielectric susceptibility tensor for which the object
exhibits resonances at prescribed frequencies and spatial distribution of the
polarization. Together with the synthesis of the material, two key concepts are
introduced: the controlled tunability of the resonant modes and the number of
essential modes, i.e. the number of modes that uniquely characterize the
spatial distribution of the dielectric susceptibility. Moreover, this approach
can be applied to design the resonant modes of any system where the
constitutive relationship is linear and local.",2307.04000v1
2023-07-10,Graphene Resonant Pressure Sensor with Ultrahigh Responsivity,"Graphene has good mechanical properties including large Young's modulus,
making it ideal for many resonant sensing applications. Nonetheless, the
development of graphene based sensors has been limited due to difficulties in
fabrication, encapsulation, and packaging. Here we report a graphene
nanoresonator based resonant pressure sensor. The graphene nano resonator is
fabricated on a thin silicon diaphragm that deforms due to pressure
differential across it. The deformation-induced strain change results in a
resonance frequency shift of the graphene nano resonator. The pressure sensing
experiments demonstrate a record high responsivity of 20Hz/Pa with a resolution
of 90Pa. The resolution of the sensing scheme is 0.003% of the full-scale range
of the pressure sensor. This exceptional performance is attributed to two
factors: maintaining a high-quality vacuum environment for the nanoresonator
and introducing stimuli through a thin silicon diaphragm. The proposed pressure
sensor design provides flexibility to adjust responsivity and range as needed.
The fabrication method is simple and has the potential to be integrated with
standard CMOS fabrication. The innovative substrate packaging allows the
coupling of the resonator's strain with pressure.",2307.04585v1
2023-07-30,The generation of high-energy electron-positron pairs during the Breit-Wheeler resonant process in a strong field of an X-ray electromagnetic wave,"The Breith-Wheeler resonant process has been theoretically studied in a
strong X-ray electromagnetic wave field under conditions when the energy of one
of the initial high-energy gamma quanta passes into the energy of a positron or
electron. These resonant conditions have been studied in detail. Analytical
formulas for the resonant differential cross-section of channels A and B of the
reaction are obtained. It is shown that the resonant differential cross-section
significantly depends on the value of the characteristic Breit-Wheeler energy,
which is determined by the parameters of the electromagnetic wave and the
initial gamma quanta. With a decrease in the characteristic Breit-Wheeler
energy, the resonant cross-section increases sharply and may exceed the
corresponding non-resonant cross-section by several orders of magnitude.",2308.02520v1
2023-08-17,Measurements of neutron total and capture cross sections of $^{139}$La and evaluation of resonance parameters,"Neutron total and capture cross sections of Lanthanum(La)-139 were measured
at the Accurate Ne-utron-Nucleus Reaction measurement Instrument (ANNRI) of the
Materials and Life Science Experimental Facility (MLF) in the Japan Proton
Accelerator Research Complex (J-PARC). The total cross section was largely
different from that in evaluated libraries, such as JENDL-5, in the energy
range from 80 to 900~eV. Resonance parameters for four resonances including one
negative resonance were obtained using a resonance analysis code, REFIT. The
resonance analysis revealed discrepancies in several resonance parameters with
the evaluated libraries. Furthermore, the information about the scattering
radius was also extracted from the results of the total cross section. The
obtained scattering radius was larger than that recorded in the evaluated
libraries.",2308.08802v1
2023-08-23,"The confluence of fractured resonances at points of dynamical, many--body flare","Resonant transport occurs when there is a matching of frequencies across some
spatial medium, increasing the efficiency of shuttling particles from one
reservoir to another. We demonstrate that in a periodically driven, many--body
titled lattice, there are sets of spatially fractured resonances. These
``emanate'' from two essential resonances due to scattering off internal
surfaces created when the driving frequency and many--body interaction strength
vary, a scattering reminiscent of lens flare. The confluence of these fractured
resonances dramatically enhances transport. At one confluence, the interaction
strength is finite and the essential resonance arises due to the interplay of
interaction with the counter--rotating terms of the periodic drive. We discuss
the origin and structure of the fractured resonances, as well as the scaling of
the conductance with system parameters. These results furnish a new example of
the richness of open, driven, many--body systems.",2308.12346v2
2023-08-24,Resonance states of the three-disk scattering system,"For the paradigmatic three-disk scattering system, we confirm a recent
conjecture for open chaotic systems, which claims that resonance states are
composed of two factors. In particular, we demonstrate that one factor is given
by universal exponentially distributed intensity fluctuations. The other
factor, supposed to be a classical density depending on the lifetime of the
resonance state, is found to be very well described by a classical
construction. Furthermore, ray-segment scars, recently observed in dielectric
cavities, dominate every resonance state at small wavelengths also in the
three-disk scattering system. We introduce a new numerical method for computing
resonances, which allows for going much further into the semiclassical limit.
As a consequence we are able to confirm the fractal Weyl law over a
correspondingly large range.",2308.12783v3
2023-09-18,Explicit Semiclassical Resonances from Many Delta Functions,"We study the scattering resonances arising from multiple $h$-dependent Dirac
delta functions on the real line in the semiclassical regime $h \rightarrow 0$.
We focus on resonances lying in strings along curves of the form $\text{Im } z
\sim -\gamma h\log(1/h)$ and find that resonances along such strings exist if
and only if $\gamma$ is a slope of a Newton polygon we construct from the
parameters. Furthermore, the set of these $\gamma$ corresponds to a complete
and disjoint partitioning of a line segment with delta functions at interval
endpoints. Hence, there are at most $N-1$ strings of resonances from $N$ delta
functions, improving a bound from (Datchev, Marzuola, & Wunsch 2023). Lastly,
we identify a 'dominant pair' of delta functions in the sense that they
correspond to the longest-living string of resonances, this string is the only
one of logarithmic shape with respect to $\text{Re } z$, and no delta functions
between them can contribute to strings of resonances. The simple properties of
delta functions permit elementary proofs, requiring just undergraduate analysis
and linear algebra.",2309.09951v1
2023-10-08,Resonant optical trapping of Janus nanoparticles in plasmonic nanoaperture,"Controlled trapping of light absorbing nanoparticles with low-power optical
tweezers is crucial for remote manipulation of small objects. This study takes
advantage of the synergetic effects of tightly confined local fields of
plasmonic nanoaperture, self-induced back-action of nanoparticles, and resonant
optical trapping method to demonstrate enhanced manipulation of Janus
nanoparticles in metallic nanohole aperture. We theoretically demonstrate that
displacement of Au-coated Janus nanoparticles toward plasmonic nanoaperture and
proper orientation of the metal coating give rise to enhanced near-field
intensity and pronounced optical force. We also explore the effect of resonant
optical trapping by employing dual laser system, where an on-resonant green
laser excites the metal-coated nanoparticle whereas an off-resonant
near-infrared laser plays trapping role. It is found that, at optimum
nanoparticle configuration, the resonant optical trapping technique can result
in three-fold enhancement of optical force, which is attributed to excitation
of surface plasmon resonance in Janus nanoparticles. The findings of this study
might pave the way for low power optical manipulation of light-absorbing
nanoparticles with possible applications in nanorobotics and drug delivery.",2310.05214v2
2023-10-12,Space-time symmetry and parametric resonance in dynamic mechanical systems,"Linear mechanical systems with time-modulated parameters can harbor
oscillations with amplitudes that grow or decay exponentially with time due to
the phenomenon of parametric resonance. While the resonance properties of
individual oscillators are well understood, identifying the conditions for
parametric resonance in systems of coupled oscillators remains challenging.
Here, we identify internal symmetries that arise from the real-valued and
symplectic nature of classical mechanics and determine the parametric resonance
conditions for periodically time-modulated mechanical metamaterials using these
symmetries. Upon including external symmetries, we find additional conditions
that prohibit resonances at some modulation frequencies for which parametric
resonance would be expected from the internal symmetries alone. In particular,
we analyze systems with space-time symmetry where the system remains invariant
after a combination of discrete translation in both space and time. For such
systems, we identify a combined space-time translation operator that provides
more information about the system than the Floquet operator does, and use it to
derive conditions for one-way amplification of traveling waves. Our results
establish an exact theoretical framework based on symmetries to engineer exotic
responses such as nonreciprocal transport and one-way amplification in
space-time modulated mechanical systems, and can be generalized to all physical
systems that obey space-time symmetry.",2310.08734v1
2023-10-18,"Native two-qubit gates in fixed-coupling, fixed-frequency transmons beyond cross-resonance interaction","Fixed-frequency superconducting qubits demonstrate remarkable success as
platforms for stable and scalable quantum computing. Cross-resonance gates have
been the workhorse of fixed-coupling, fixed-frequency superconducting
processors, leveraging the entanglement generated by driving one qubit
resonantly with a neighbor's frequency to achieve high-fidelity, universal
CNOTs. Here, we use on-resonant and off-resonant microwave drives to go beyond
cross-resonance, realizing natively interesting two-qubit gates that are not
equivalent to CNOTs. In particular, we implement and benchmark native ISWAP,
SWAP, $\sqrt{\text{ISWAP}}$, and BSWAP gates. Furthermore, we apply these
techniques for an efficient construction of the B-gate: a perfect entangler
from which any two-qubit gate can be reached in only two applications. We show
these native two-qubit gates are better than their counterparts compiled from
cross-resonance gates. We elucidate the resonance conditions required to drive
each two-qubit gate and provide a novel frame tracking technique to implement
them in Qiskit.",2310.12146v1
2023-11-09,Magnon-phonon coupling of synthetic antiferromagnets in a surface acoustic wave cavity resonator,"We use a surface acoustic wave (SAW) cavity resonator to study the coupling
of acoustic magnons in a synthetic antiferromagnet (SAF) and the phonons
carried by SAWs. The SAF is composed of a CoFeB/Ru/CoFeB trilayer and the
scattering matrix of the SAW resonator is studied to assess the coupling. We
find that the spectral linewidth of the SAW resonator is modulated when the
frequency of the excited magnons approaches the SAW resonance frequency.
Moreover, the linewidth modulation varies with the magnitude and orientation of
the external magnetic field. Such change in the spectral linewidth can be well
reproduced using macrospin-like model calculations. From the model analyses, we
estimate the magnon-phonon coupling strength to be $\sim$15.6 MHz at a SAW
resonance frequency of 1.8 GHz: the corresponding magnomechanical cooperativity
is $\sim$0.66. As the spectral shape hardly changes in a CoFeB single layer
reference sample under the same experimental condition, these results show that
SAF provides an ideal platform to study magnon-phonon coupling in a SAW cavity
resonator.",2311.05275v1
2023-11-15,Active elastic metamaterials with equidistant solely resonant bandgaps,"Elastic metamaterials are man-made structures with properties that transcend
naturally occurring materials. One predominant feature of elastic metamaterials
is locally resonant bandgaps, i.e., frequency ranges at which wave propagation
is blocked. Locally resonant bandgaps appear at relatively low frequency and
arise from the existence of periodically placed mechanical local resonators.
Typically, elastic metamaterials exhibit both locally resonant and
Bragg-scattering bandgaps, which can generally be different in width and
frequency ranges. This paper proposes two designs of active elastic
metamaterials that only exhibit locally resonant bandgaps, which are infinite
in number, evenly spaced in the frequency spectrum, and identical in width. The
mathematical model is established using the transfer matrix method and
synthesis of locally resonant bandgaps is achieved via an active elastic
support with carefully designed frequency-dependent stiffness. A single unit
cell of each proposed metamaterials is thoroughly studied, and its dispersion
relation is derived analytically, along with the periodically repeating bandgap
limits and widths. Following the dispersion analysis and bandgap parametric
studies, finite arrays of the proposed metamaterials are considered, and their
frequency response is calculated to verify the analytical predictions from
dispersion analyses.",2311.08959v2
2023-11-17,Resonance of Geometric Quantities and Hidden Symmetry in the Asymmetric Rabi Model,"We present the interesting resonance of two kinds of geometric quantities,
namely the Aharonov-Anandan (AA) phase and the time-energy uncertainty, and
reveal the relation between resonance and the hidden symmetry in the asymmetric
Rabi model by numerical and analytical methods. By combining the
counter-rotating hybridized rotating-wave method with time-dependent
perturbation theory, we solve systematically the time evolution operator and
then obtain the geometric phase of the Rabi model. In comparison with the
numerically exact solutions, we find that the analytical results accurately
describe the geometric quantities in a wide parameter space. We unveil the
effect of the bias on the resonance of geometric quantities, (1) the positions
of all harmonic resonances stemming from the shift of the Rabi frequency at the
presence of the bias; (2) the occurrence of even order harmonic resonance due
to the bias. When the driving frequency is equal to the subharmonics of the
bias, the odd higher-order harmonic resonances disappear. Finally, the hidden
symmetry has a resemblance to that of the quantum Rabi model with bias, which
indicates the quasienergy spectra are similar to the energy spectra of the
latter.",2311.10249v1
2023-12-07,Mass Ratio Dependence of Three-Body Resonance Lifetimes in 1D and 3D,"We present a theoretical study of resonance lifetimes in a two-component
three-body system, specifically examining the decay of three-body resonances
into a deep dimer and an unbound particle. Utilising the Gaussian expansion
method together with the complex scaling method, we obtain the widths of these
resonances from first principles. We focus on mass ratios in the typical range
for mixtures of ultracold atoms and reveal a pronounced dependence of the
resonance widths on the mass ratio: a distinct maximum near the equal-mass
scenario and a rapid decrease away from it. Moreover, we show that this
behaviour is not covered by the analytical formula of Pen'kov~[Phys. Rev. A 60,
3756 (1999)]. Notably, near the mass ratio for Caesium-Lithium mixtures, we
obtain nearly vanishing widths of the resonances which validates to treat them
in the bound state approximation. In addition, we perform our analysis on the
resonance widths in both one and three dimensions and find that their
qualitative dependence on the mass ratio agrees.",2312.04080v1
2023-12-19,Cavity Continuum,"We experimentally demonstrate and numerically analyze large arrays of
whispering gallery resonators. Using fluorescent mapping, we measure the
spatial distribution of the cavity-ensemble's resonances, revealing that light
reaches distant resonators in various ways, including while passing through
dark gaps, resonator groups, or resonator lines. Energy spatially decays
exponentially in the cavities. Our practically infinite periodic array of
resonators, with a quality factor [Q] exceeding 10^7, might impact a new type
of photonic ensembles for nonlinear optics and lasers using our cavity
continuum that is distributed, while having high-Q resonators as unit cells.",2312.12632v1
2023-12-22,Nucleon resonance parameters from Roy-Steiner equations,"A reliable determination of the pole parameters and residues of nucleon
resonances is notoriously challenging, given the required analytic continuation
into the complex plane. We provide a comprehensive analysis of such resonance
parameters accessible with Roy-Steiner equations for pion-nucleon scattering -
a set of partial-wave dispersion relations that combines the constraints from
analyticity, unitarity, and crossing symmetry - most prominently of the
$\Delta(1232)$ resonance. Further, we study the Roper, $N(1440)$, resonance,
which lies beyond the strict domain of validity, in comparison to Pad\'e
approximants, comment on the role of subthreshold singularities in the
$S$-wave, and determine the residues of the $f_0(500)$, $\rho(770)$, and
$f_0(980)$ resonances in the $t$-channel process $\pi\pi\to\bar NN$. The latter
allows us to test - for the first time fully model independently in terms of
the respective residues - universality of the $\rho(770)$ couplings and the
Goldberger-Treiman relation expected if the scalars behaved as dilatons, in
both cases revealing large deviations from the narrow-resonance limit.",2312.15015v1
2023-12-23,From all-dieletric nanoresonators to extended quasi-static plasmonic resonators,"We derive the electromagnetic medium equivalent to a cluster of
all-dielectric nanoparticles (i.e. enjoying high refractive indices),
distributed periodically in a smooth domain $\Omega$, while excited at nearly
resonating dielectric incident frequencies (i.e. subwavelength Mie-resonant
frequencies). This effective medium is an alteration of the permeability that
keeps the permittivity unchanged. We provide regimes under which the effective
permeability can be positive or negative valued. In addition, if the incident
frequency is close to any of the subwavelength all-dielectric resonances, then
the distributed cluster behaves as an extended quasi-static plasmonic
resonator. Therefore, exciting the cluster of all-dielectric nanoresonators
with nearly resonating incident frequencies, we can generate an extended
quasi-static plasmonic resonator which creates giant electromagnetic fields in
its surrounding.",2312.15149v1
2024-01-10,HYPIC: A fast hybrid EM PIC-MCC code for ion cyclotron resonance energization in cylindrical coordinate system,"Ion cyclotron resonance energization (ICRE) such as ion cyclotron resonance
heating (ICRH) is widely applied to magnetic confinement fusion and high-power
electric propulsion. Since ICRE involves cyclotron resonance processes, a
kinetic model is required. Both conventional particle-in-cell (PIC) simulations
and solving the Boltzmann equation require enormous computation and memory. The
hybrid simulation incorporating of adiabatic electrons and PIC ions allows both
a substantial reduction in computation and the inclusion of cyclotron resonance
effects. Under the adiabatic electron approximation, we have developed a
two-dimensional (r,z) hybrid electromagnetic (EM) PIC-MCC (Monte-Carlo
collision) simulation program, named HYPIC. The advantages of HYPIC are the
inclusion of ion kinetic effects, electrostatic (ES) and EM effects, and
collisional effects of ions and electrons, with a small computation. The HYPIC
program is able to fast simulate the antenna-plasma interactions and the ion
cyclotron resonance energization and/or ion cyclotron resonance heating
processes in linear devices, such as high-power electric propulsion, magnetic
mirror, and field-reversed-configuration (FRC), etc.",2401.04897v1
2024-02-22,Low-frequency Resonances in Grid-Forming Converters: Causes and Damping Control,"Grid-forming voltage-source converter (GFM-VSC) may experience low-frequency
resonances, such as synchronous resonance (SR) and sub-synchronous resonance
(SSR), in the output power. This paper offers a comprehensive study on the root
causes of low-frequency resonances with GFM-VSC systems and the damping control
methods. The typical GFM control structures are introduced first, along with a
mapping between the resonances and control loops. Then, the causes of SR and
SSR are discussed, highlighting the impacts of control interactions on the
resonances. Further, the recent advancements in stabilizing control methods for
SR and SSR are critically reviewed with experimental tests of a GFM-VSC under
different grid conditions.",2402.14543v1
2024-03-01,Production of Resonances in Partial Chemical Equilibrium,"Within the model of partial chemical equilibrium (PCE) we calculate the
multiplicity ratios of selected unstable resonances to given stable species. We
focus on those ratios that have been measured either in Pb+Pb collisions at the
LHC or in Au+Au collisions at the top RHIC energy. The model provides an
interpretation how in an expanding hadronic fireball with decreasing
temperature the final numbers of stable hadrons after decays of all resonances
remain unchanged. Each stable species acquires its own chemical potential and
the resonances are kept in equilibrium with them. Multiplicities of unstable
resonances provide a test of this scenario. We observe that the ratios of
$K^{*}/K$ and $\rho^0/\pi$ fit reasonably well into the picture of single
kinetic freeze-out of the single-particle spectra, but the $\phi$-meson and
hyperon resonances are not reproduced by this model.",2403.00427v1
2024-03-13,Dielectric microwave resonator with large optical apertures for spin-based quantum devices,"Towards a spin-based quantum microwave-optical photon transducer, we
demonstrate a low-loss dielectric microwave resonator with an internal quality
factor of $2.30\times10^4$ while accommodating optical apertures with a
diameter of $8\, \mathrm{mm}$. The two seemingly conflicting requirements, high
quality factor and large optical apertures, are satisfied thanks to the large
dielectric constant of rutile ($\mathrm{TiO_2}$). The quality factor is limited
by radiation loss, and we confirmed by numerical simulation that this
dielectric resonator can achieve a quality factor exceeding $10^6$ by extending
the height of the resonator enclosure. Using this resonator, we performed both
continuous-wave (cw) and pulse electron spin resonance (ESR) spectroscopy on
2,2-diphenyl-1-picrylhydrazyl (DPPH) crystalline powder and P1 centers in a
diamond crystal in a dilution refrigerator. The cw ESR spectroscopy
demonstrated high-cooperativity and strong spin-resonator coupling with the
DPPH and P1 centers respectively, while the pulse ESR spectroscopy successfully
measured longitudinal and transverse relaxation times.",2403.08458v1
2024-04-08,Linear and Nonlinear Coupling of Twin-Resonators with Kerr Nonlinearity,"Nonlinear effects in microresonators are efficient building blocks for
all-optical computing and telecom systems. With the latest advances in
microfabrication, coupled microresonators are used in a rapidly growing number
of applications. In this work, we investigate the coupling between
twin-resonators in the presence of Kerr-nonlinearity. We use an experimental
setup with controllable coupling between two high-Q resonators and discuss the
effects caused by the simultaneous presence of linear and non-linear coupling
between the optical fields. Linear-coupling-induced mode splitting is observed
at low input powers, with the controllable coupling leading to a tunable mode
splitting. At high input powers, the hybridized resonances show spontaneous
symmetry breaking (SSB) effects, in which the optical power is unevenly
distributed between the resonators. Our experimental results are supported by a
detailed theoretical model of nonlinear twin-resonators. With the recent
interest in coupled resonator systems for neuromorphic computing, quantum
systems, and optical frequency comb generation, our work provides important
insights into the behavior of these systems at high circulating powers.",2404.05646v1
2001-08-28,Resonant Raman Scattering by Charge Density and Single Particle Excitations in Semiconductor Nanostructures: A Generalized Interband-Resonant Random-Phase-Approximation Theory,"We develop a generic theory for the resonant inelastic light (Raman)
scattering by a conduction band quantum plasma taking into account the presence
of the filled valence band in doped semiconductor nanostructures within a
generalized resonant random phase approximation (RPA). Our generalized RPA
theory explicitly incorporates the two-step resonance process where an electron
from the filled valence band is first excited by the incident photon into the
conduction band before an electron from the conduction band falls back into the
valence band emitting the scattered photon. We show that when the incident
photon energy is close to a resonance energy, i.e. the valence-to-conduction
band gap of the semiconductor structure, the Raman scattering spectral weight
at single particle excitation energies may be substantially enhanced even for
long wavelength excitations, and may become comparable to the spectral weight
of collective charge density excitations (plasmon). Away from resonance, i.e.
when the incident photon energy is different from the band gap energy, plasmons
dominate the Raman scattering spectrum. We find no qualitative difference in
the resonance effects on the Raman scattering spectra among systems of
different dimensionalities (one, two and three) within RPA. This is explained
by the decoherence effect of the resonant interband transition on the
collective motion of conduction band electrons. Our theoretical calculations
agree well (qualitatively and semi-quantitatively) with the available
experimental results, in contrast to the standard nonresonant RPA theory which
predicts vanishing long wavelength Raman spectral weight for single particle
excitations.",0108468v1
2004-02-26,Superslow Self-Organized Motions in a Multimode Microwave Phonon Laser (Phaser) under Resonant Destabilization of Stationary Acoustic Stimulated Emission,"Two qualitatively different kinds of resonant destabilization of phonon
stimulated emission (SE) are experimentally revealed for periodically forced
multimode ruby phaser (phonon laser) operating at SE frequencies about 9 GHz,
i.e. at microwave acoustic wavelengths of 1 micron. The inversion state of
Cromium(3+) spin-system in ruby was created by electromagnetic pump at 23 GHz.
Under deep modulation of pump power at low frequencies OMEGA_m = 70-200 Hz
deterministic chaotic reconfigurations of the acoustic microwave power spectra
(AMPS) were observed. This range of SE destabilization corresponds to the
relaxational resonance that is well known for optical class-B lasers. Outside
the relaxational resonance range, namely at ultra-low (infrasonic) frequencies
OMEGA_m about 10 Hz, the other type of resonant destabilization of stationary
phonon SE was observed by us for the first time. This new nonlinear resonance
(we call it lambda-resonance) manifests itself as very slow and periodically
repeated self-reconfigurations of AMPS. Near the vertex of lambda-resonance the
period of AMPS self-reconfigurations takes giant values of several hours (at
T=1.8 K). The second type of SE resonant destabilization is explained in terms
of antiphase energy exchange between acoustic SE modes in a modulated phaser.
The role of polarized nuclear spin-reservoir (formed by Aluminium-27 nuclei of
the ruby crystalline matrix) in these superslow self-organized motions is
discussed. PACS: 05.65.+b, 42.65.Sf, 43.35.+d",0402640v1
2002-06-20,Resonance Behavior and Partial Averaging in a Three-Body System with Gravitational Radiation Damping,"In a previous investigation, a model of three-body motion was developed which
included the effects of gravitational radiation reaction. The aim was to
describe the motion of a relativistic binary pulsar that is perturbed by a
third mass and look for resonances between the binary and third mass orbits.
Numerical integration of an equation of relative motion that approximates the
binary gives evidence of such resonances. These $(m:n)$ resonances are defined
for the present purposes by the resonance condition, $m\omega=2n\Omega$, where
$m$ and $n$ are relatively prime integers and $\omega$ and $\Omega$ are the
angular frequencies of the binary orbit and third mass orbit, respectively. The
resonance condition consequently fixes a value for the semimajor axis $a$ of
the binary orbit for the duration of the resonance because of the Kepler
relationship $\omega=a^{-3/2}$. This paper outlines a method of averaging
developed by Chicone, Mashhoon, and Retzloff which renders a nonlinear system
that undergoes resonance capture into a mathematically amenable form. This
method is applied to the present system and one arrives at an analytical
solution that describes the average motion during resonance. Furthermore,
prominent features of the full nonlinear system, such as the frequency of
oscillation and antidamping, accord with their analytically derived formulae.",0206060v2
1994-01-27,Influence of Kaonic Resonances on the CP Violation in $B\to K^*γ$Like Processes,"We consider CP violating effects in decays of the type $B\rightarrow
k_i\gamma \rightarrow K\pi\gamma$, $K^*\pi\gamma$ and $K\rho\gamma$, where
$k_i$ represents a strange meson resonance. We include in our calculations five
of the low-lying resonances with quantum numbers ($J^P$) $1^-$, $1^+$ and
$2^+$. At the quark level these decays are driven by the penguin graph as well
as tree graphs. CP violation arises due to the difference in the CKM phase
between these graphs. We model the final state interaction of the hadronic
system using the low lying $k_i$ resonances. We find that radiative decays of B
mesons give rise to four of the five kaonic resonances at about $1$ to $7 \%$
of the inclusive $b \rightarrow s \gamma$ rate. We find that the probability of
formation of the other three higher resonances is roughly the same as that of
$K^*(892)$, which was recently seen at CLEO. In addition to the partial rate
asymmetry which arises due to interference between resonances of the same
quantum numbers, we show how interference between resonances of the same
parity, and also between resonances of the opposite parity, result in two
different types of energy asymmetries. CP differential asymmetries at the level
of a few percent seem possible. We thus obtain CP violating distributions which
may be observed in a sample of about $10^9$\relax $B^\pm$ mesons.",9401347v1
1999-09-06,Parametric Resonance For Complex Fields,"Recently, there have been studies of parametric resonance decay of
oscillating real homogeneous cosmological scalar fields, in both the
narrow-band and broad-band case, primarily within the context of inflaton decay
and (p)reheating. However, many realistic models of particle cosmology, such as
supersymmetric ones, inherently involve complex scalar fields. In the
oscillations of complex scalars, a relative phase between the oscillations in
the real and imaginary components may prevent the violations of adiabaticity
that have been argued to underly broad-band parametric resonance. In this
paper, we give a treatment of parametric resonance for the decay of homogeneous
complex scalar fields, analyzing properties of the resonance in the presence of
out of phase oscillations of the real and imaginary components. For
phase-invariant coupling of the driving parameter field to the decay field, and
Mathieu type resonance, we give an explicit mapping from the complex resonance
case to an equivalent real case with shifted resonance parameters. In addition,
we consider the consequences of the complex field case as they apply to
``instant preheating,'' the explosive decay of non-convex potentials, and
resonance in an expanding FRW universe. Applications of our considerations to
supersymmetric cosmological models will be presented elsewhere.",9909256v1
2000-07-26,Gaussian Sum-Rules and Prediction of Resonance Properties,"Techniques for using Gaussian QCD sum-rules to predict hadronic resonance
properties are developed for single-resonance and two-resonance
phenomenological models, and criteria are developed for determining which of
these models is required for analyzing a particular hadronic channel. The
vector current sum-rule coupled to the $\rho$ meson is shown to be consistent
with a single resonance model, and the Gaussian sum-rule analysis results in an
accurate $\rho$ mass prediction which exhibits excellent agreement between the
theoretical prediction of the Gaussian sum-rule and the phenomenological model.
A two-resonance model is shown to be necessary for the Gaussian sum-rule for
the non-strange quark scalar ($\bar n n$) currents. The two-resonance Gaussian
sum-rule analysis of the isoscalar and isovector ($I=0,1$) $\bar n n$ scalar
mesons exhibits excellent agreement between the theoretical prediction and
phenomenological model. The prediction of the resonance properties of the
$I=0,1$ $\bar n n$ scalar mesons in this two-resonance model provides valuable
information for the interpretation of the scalar mesons, including the X(1775).",0007299v2
1999-08-02,Microscopic Studies on Two-Phonon Giant Resonances,"A new class of giant resonances in nuclei, namely double giant resonances, is
discussed. They are giant resonances built on top of other giant resonances.
Investigation on their properties, together with similar studies on low-lying
two-phonon states, should give an answer on how far the harmonic picture of
boson-type excitations holds in the finite fermion systems like atomic nuclei.
  The main attention in this review is paid to double giant dipole resonances
(DGDR) which are observed in relativistic heavy ion collisions with very large
cross sections. A great experimental and theoretical effort is underway to
understand the reaction mechanism which leads to the excitation of these states
in nuclei, as well as the better microscopic understanding of their properties.
The Coulomb mechanism of the excitation of single and double giant resonances
in heavy ion collision at different projectile energies is discussed in
details. A contribution of the nuclear excitation to the total cross section of
the reaction is also considered. The Coulomb excitation of double resonances is
described within both, the second-order perturbation theory approach and in
coupled-channels calculation. The properties of single and double resonances
are considered within the phenomenologic harmonic vibrator model and
microscopic quasiparticle-RPA approach. For the last we use the
Quasiparticle-Phonon Model (QPM) the basic ideas and formalism of which are
presented. The QPM predictions of the DGDR properties (energy centroids,
widths, strength distributions, anharmonicities and excitation cross sections)
are compared to predictions of harmonic vibrator model, results of other
microscopic calculations and experimental data available.",9908003v1
2005-10-18,Forward-angle K+ Lambda photoproduction in a Regge-plus-resonance approach,"We present an effective-Lagrangian description for forward-angle K+ Lambda
photoproduction from the proton, valid for photon lab energies from threshold
up to 16 GeV. The high-energy part of the amplitude is modeled in terms of
t-channel Regge-trajectory exchange. The sensitivity of the calculated
observables to the Regge-trajectory phase is investigated in detail. The model
is extended towards the resonance region by adding a number of s-channel
resonances to the t-channel background. The proposed hybrid
``Regge-plus-resonance'' (RPR) approach allows one to exploit the
p(gamma,K+)Lambda data in their entirety, resulting in stronger constraints on
both the background and resonance couplings. The high-energy data can be used
to fix the background contributions, leaving the resonance couplings as the
sole free parameters in the resonance region. We compare various
implementations of the RPR model, and explore to what extent the description of
the data can be improved by introducing the ``new'' resonances D13(1900) and
P11(1900). Despite its limited number of free parameters, the proposed RPR
approach provides an efficient description of the p(gamma,K+)Lambda dynamics in
and beyond the resonance region.",0510056v3
2003-08-04,Modes of wave-chaotic dielectric resonators,"Dielectric optical micro-resonators and micro-lasers represent a realization
of a wave-chaotic system, where the lack of symmetry in the resonator shape
leads to non-integrable ray dynamics. Modes of such resonators display a rich
spatial structure, and cannot be classified through mode indices which would
require additional constants of motion in the ray dynamics. Understanding and
controlling the emission properties of such resonators requires the
investigation of the correspondence between classical phase space structures of
the ray motion inside the resonator and resonant solutions of the wave
equations. We first discuss the breakdown of the conventional eikonal
approximation in the short wavelength limit, and motivate the use of
phase-space ray tracing and phase space distributions. Next, we introduce an
efficient numerical method to calculate the quasi-bound modes of dielectric
resonators, which requires only two diagonalizations per N states, where N is
approximately equal to the number of half-wavelengths along the perimeter. The
relationship between classical phase space structures and modes is displayed
via the Husimi projection technique. Observables related to the emission
pattern of the resonator are calculated with high efficiency.",0308016v1
2008-05-13,Distortion and preservation of Giant resonances in Endohedral Atoms A@C60,"It is demonstrated in this Letter that the effect of the fullerene shell upon
atomic Giant resonance decisively depends upon energy of photoelectrons, by
which the resonance decay. According to the prediction in [1], the Giant
resonance in Xe is strongly modified in the endohedral Xe@C60 being transformed
from a single broad and powerful maximum in Xe into four quite narrow but with
almost the same total oscillator strength. On the contrary, the 4d Giant
resonances in ions Ce3+ (the electronic structure that Ce has, when stuffed
into fullerene), in Ce4+, and Eu are considered. In none of them the 4d Giant
resonance in endohedrals is affected essentially. This is because the decay of
the Giant resonances in these endohedrals proceeds by emission of fast
photoelectrons that are almost unaffected by the C60 shell. The results
obtained give at least qualitative explanation to the fact that recent
observation of 4d Giant resonance in Ce@C82+, where the Giant resonance was
observed as a maximum without noticeable structure.",0805.1934v2
2008-06-13,Control of scroll wave turbulence using resonant perturbations,"Turbulence of scroll waves is a sort of spatio-temporal chaos that exists in
three-dimensional excitable media. Cardiac tissue and the Belousov-Zhabotinsky
reaction are examples of such media. In cardiac tissue, chaotic behaviour is
believed to underlie fibrillation which, without intervention, precedes cardiac
death. In this study we investigate suppression of the turbulence using
stimulation of two different types, ""modulation of excitability"" and ""extra
transmembrane current"". With cardiac defibrillation in mind, we used a single
pulse as well as repetitive extra current with both constant and feedback
controlled frequency. We show that turbulence can be terminated using either a
resonant modulation of excitability or a resonant extra current. The turbulence
is terminated with much higher probability using a resonant frequency
perturbation than a non-resonant one. Suppression of the turbulence using a
resonant frequency is up to fifty times faster than using a non-resonant
frequency, in both the modulation of excitability and the extra current modes.
We also demonstrate that resonant perturbation requires strength one order of
magnitude lower than that of a single pulse, which is currently used in
clinical practice to terminate cardiac fibrillation. Our results provide a
robust method of controlling complex chaotic spatio-temporal processes.
Resonant drift of spiral waves has been studied extensively in two dimensions,
however, these results show for the first time that it also works in three
dimensions, despite the complex nature of the scroll wave turbulence.",0806.2262v2
2009-02-05,Multiple Resonances in Fluid-Loaded Vibrating Structures,"This study deals with spectral analysis of fluid-loaded vibrating structure.
It was recently observed in a numerical study on a high order perturbation
method under heavy fluid loading that a loaded vibrating plate results, not
only in the classical frequency shift of the in vacuo single resonance (in both
the real part because of the fluid added mass and the imaginary part because of
energy lost by radiation into the fluid), but also in an increase in the number
of the resonance frequencies : as a result of the loading, a single in vacuo
resonance frequency of the structure is transformed into a multiple resonance
frequency. Here we show that this phenomenon is said to be a refinement of the
Sanchez's classical result in their book (Vibration and coupling of continuous
systems, Springer-Verlag -1989-, paragraph 9.3) where it was established, using
asymptotic analysis, that in the case of a light loading conditions ""the
scattering frequencies of a fluid loaded elastic structure (ie the resonance
frequencies) are nearly the real eigenfrequencies of the elastic body alone and
the complex scattering frequencies of the fluid with a rigid solid"". A
theoretical explanation of the observed phenomenon of multiple resonance is
given using classical results of the distribution of zeros of entire functions.
It is established that every single in vacuo resonance frequency of a
rectangular plate is transformed into an infinite number of resonances when the
fluid-loading is accounted for.",0902.0925v1
2009-03-13,Resonance saturation of the chiral couplings at NLO in 1/Nc,"The precision obtainable in phenomenological applications of Chiral
Perturbation Theory is currently limited by our lack of knowledge on the
low-energy constants (LECs). The assumption that the most important
contributions to the LECs come from the dynamics of the low-lying resonances,
often referred to as the resonance saturation hypothesis, has stimulated the
use of large-Nc resonance lagrangians in order to obtain explicit values for
the LECs. We study the validity of the resonance saturation assumption at the
next-to-leading order in the 1/Nc expansion within the framework of Resonance
Chiral Theory (RChT). We find that, by imposing QCD short-distance constraints,
the chiral couplings can be written in terms of the resonance masses and
couplings and do not depend explicitly on the coefficients of the chiral
operators in the Goldstone boson sector of RChT. As we argue, this is the
counterpart formulation of the resonance saturation statement in the context of
the resonance lagrangian. Going beyond leading order in the 1/Nc counting allow
us to keep full control of the renormalization scale dependence of the LEC
estimates.",0903.2440v2
2009-04-11,Fermion Localization and Resonances on A de Sitter Thick Brane,"In arXiv:0901.3543, the simplest Yukawa coupling $\eta\bar{\Psi}\phi\chi\Psi$
was considered for a two-scalar-generated Bloch brane model. Fermionic
resonances for both chiralities were obtained, and their appearance is related
to branes with internal structure. Inspired on this result, we investigate the
localization and resonance spectrum of fermions on a one-scalar-generated $dS$
thick brane with a class of scalar-fermion couplings $\eta\bar{\Psi}\phi^k\Psi$
with positive odd integer $k$. A set of massive fermionic resonances for both
chiralities are obtained when provided large couple constant $\eta$. We find
that the masses and life-times of left and right chiral resonances are almost
the same, which demonstrates that it is possible to compose massive Dirac
fermions from the left and right chiral resonances. The resonance with lower
mass has longer life-time. For a same set of parameters, the number of
resonances increases with $k$ and the life-time of the lower level resonance
for larger $k$ is much longer than the one for smaller $k$.",0904.1785v2
2009-05-25,Resonant Spectrum Analysis of the Conductance of Open Quantum System and Three Types of Fano Parameter,"We explain the Fano peak (an asymmetric resonance peak) as an interference
effect involving resonant states. We reveal that there are three types of Fano
asymmetry according to their origins: the interference between a resonant state
and an anti-resonant state, that between a resonant state and a bound state,
and that between two resonant states. We show that the last two show the
asymmetric energy dependence given by Fano, but the first one shows a slightly
different form. In order to show the above, we analytically and microscopically
derive a formula where we express the conductance purely in terms of the
summation over all discrete eigenstates including resonant states and
anti-resonant states, without any background integrals. We thereby obtain
microscopic expressions of the Fano parameters that describe the three types of
the Fano asymmetry. One of the expressions indicate that the corresponding Fano
parameter becomes complex under an external magnetic field.",0905.3953v4
2009-06-05,Delay-induced multiple stochastic resonances on scale-free neuronal networks,"We study the effects of periodic subthreshold pacemaker activity and
time-delayed coupling on stochastic resonance over scale-free neuronal
networks. As the two extreme options, we introduce the pacemaker respectively
to the neuron with the highest degree and to one of the neurons with the lowest
degree within the network, but we also consider the case when all neurons are
exposed to the periodic forcing. In the absence of delay, we show that an
intermediate intensity of noise is able to optimally assist the pacemaker in
imposing its rhythm on the whole ensemble, irrespective to its placing, thus
providing evidences for stochastic resonance on the scale-free neuronal
networks. Interestingly thereby, if the forcing in form of a periodic pulse
train is introduced to all neurons forming the network, the stochastic
resonance decreases as compared to the case when only a single neuron is paced.
Moreover, we show that finite delays in coupling can significantly affect the
stochastic resonance on scale-free neuronal networks. In particular,
appropriately tuned delays can induce multiple stochastic resonances
independently of the placing of the pacemaker, but they can also altogether
destroy stochastic resonance. Delay-induced multiple stochastic resonances
manifest as well-expressed maxima of the correlation measure, appearing at
every multiple of the pacemaker period. We argue that fine-tuned delays and
locally active pacemakers are vital for assuring optimal conditions for
stochastic resonance on complex neuronal networks.",0906.1186v1
2009-07-15,Mean shear flows generated by nonlinear resonant Alfven waves,"In the context of resonant absorption, nonlinearity has two different
manifestations. The first is the reduction in amplitude of perturbations around
the resonant point (wave energy absorption). The second is the generation of
mean shear flows outside the dissipative layer surrounding the resonant point.
Ruderman et al. [Phys. Plasmas 4, 75 (1997)] studied both these effects at the
slow resonance in isotropic plasmas. Clack et al. [Astron. Astrophys. 494}, 317
(2009)] investigated nonlinearity at the Alfven resonance, however, they did
not include the generation of mean shear flow. In this present paper, we
investigate the mean shear flow, analytically, and study its properties. We
find that the flow generated is parallel to the magnetic surfaces and has a
characteristic velocity proportional to $\epsilon^{1/2}$, where $\epsilon$ is
the dimensionless amplitude of perturbations far away from the resonance. This
is, qualitatively, similar to the flow generated at the slow resonance. The
jumps in the derivatives of the parallel and perpendicular components of mean
shear flow across the dissipative layer are derived. We estimate the generated
mean shear flow to be of the order of $10{\rm kms}^{-1}$ in both the solar
upper chromosphere and solar corona, however, this value strongly depends on
the choice of boundary conditions. It is proposed that the generated mean shear
flow can produce a Kelvin--Helmholtz instability at the dissipative layer which
can create turbulent motions. This instability would be an additional effect,
as a Kelvin--Helmholtz instability may already exist due to the velocity field
of the resonant Alfven waves. This flow can also be superimposed onto existing
large scale motions in the solar upper atmosphere.",0907.2624v1
2009-11-13,Two-resonator circuit QED: Dissipative Theory,"We present a theoretical treatment for the dissipative two-resonator circuit
quantum electrodynamics setup referred to as quantum switch. There, switchable
coupling between two superconducting resonators is mediated by a
superconducting qubit operating in the dispersive regime, where the qubit
transition frequency is far detuned from those of the resonators. We derive an
effective Hamiltonian for the quantum switch beyond the rotating wave
approximation and study the dissipative dynamics within a Bloch-Redfield
quantum master equation approach. We derive analytically how the qubit affects
the quantum switch even if the qubit has no dynamics, and we estimate the
strength of this influence. The analytical results are corroborated by
numerical calculations, where coherent oscillations between the resonators, the
decay of coherent and Fock states, and the decay of resonator-resonator
entanglement are studied. Finally, we suggest an experimental protocol for
extracting the damping constants of qubit and resonators by measuring the
quadratures of the resonator fields.",0911.2657v4
2010-03-05,A Hybrid Mechanism Forming a 2:1 Librating-Circulating Resonant Configuration in the Planetary System,"A diversity of resonance configurations may be formed under different
migration of two giant planets. And the researchers show that the HD 128311 and
HD 73526 planetary systems are involved in a 2:1 mean motion resonance but not
in apsidal corotation, because one of the resonance argument circulates over
the dynamical evolution. In this paper, we investigate potential mechanisms to
form the 2:1 librating-circulating resonance configuration.
  In the late stage of planetary formation, scattering or colliding among
planetesimals and planetary embryos can frequently occur. Hence, in our model,
we consider a planetary configuration of two giants together with few
terrestrial planets. We find that both colliding or scattering events at very
early stage of dynamical evolution can influence the configurations trapped
into resonance. A planet-planet scattering of a moderate terrestrial planet, or
multiple scattering of smaller planets in a crowded planetary system can change
the resonant configuration. In addition, collision or merging can alter the
masses and location of the giant planets, which also play an important role in
shaping the resonant configuration during the dynamical evolution. In this
sense, the librating-circulating resonance configuration is more likely to form
by a hybrid mechanism of scattering and collision.",1003.1193v1
2010-03-18,Continuation of periodic orbits in two-planet resonant systems,"The continuation of resonant periodic orbits from the restricted to the
general three body problem is studied in a systematic way. Starting from the
Keplerian unperturbed system we obtain the resonant families of the circular
restricted problem. Then we find all the families of the resonant elliptic
restricted three body problem which bifurcate from the circular model. All
these families are continued to the general three body problem, and in this way
we can obtain a global picture of all the families of periodic orbits of a
two-planet resonant system. We consider planar motion only. We show that the
continuation follows a scheme proposed by Bozis and Hadjidemetriou (1976) for
symmetric orbits. Our study includes also asymmetric periodic orbits, which
exist in cases of external resonances. The families formed by passing from the
restricted to the general problem are continued within the framework of the
general problem by varying the planetary mass ratio $\rho$. We obtain
bifurcations which are caused either due to collisions of the families in the
space of initial conditions or due to the vanishing of bifurcation points. Our
study refers to the whole range of planetary mass ratio values ($\rho \in
(0,\infty)$) and, therefore we include the passage from external to internal
resonances. In the present work, our numerical study includes the case of the
2/1 and 1/2 resonance. The same method can be used to study all other planetary
resonances.",1003.3537v1
2010-12-15,Strong interference effects in the resonant Auger decay of atoms induced by intense X-Ray fields,"The theory of resonant Auger decay of atoms in a high intensity coherent
X-ray pulse is presented. The theory includes the coupling between the ground
state and the resonance due to an intense X-ray pulse, taking into account the
decay of the resonance and the direct photoionization of the ground state, both
populating the final ionic states coherently. The theory also considers the
impact of the direct photoionization of the resonance state itself which
typically populates highly-excited ionic states. The combined action of the
resonant decay and of the direct ionization of the ground state in the field
induces a non-hermitian time-dependent coupling between the ground and the
'dressed' resonance stats. The impact of these competing processes on the total
electron yield and on the 2s$^2$2p$^{4}(^1\mathrm{D})$3p $^2$P spectator and
2s$^1$2p$^{6}$ $^2$S participator Auger decay spectra of the Ne 1s$\to$3p
resonance is investigated. The role of the direct photoionization of the ground
state and of the resonance increases dramatically with the field intensity.
This results in strong interference effects with distinct patterns in the
electron spectra, different for the participator and spectator final states.",1012.3399v1
2011-08-16,"The Glashow resonance at IceCube: signatures, event rates and $pp$ vs. $pγ$ interactions","We revisit the signatures of the Glashow resonance process $\bar{\nu}_e e \to
W$ in the high-energy astrophysical neutrino observatory IceCube. We note that
in addition to the standard hadronic and electromagnetic showers produced by an
incoming neutrino at the resonance energy of $E_\nu \approx 6.3$ PeV, there are
two clear signals of the process: the ""pure muon"" from $\bar{\nu}_e e \to
\bar{\nu}_\mu \mu$ and the ""contained lollipop"" from $\bar{\nu}_e e \to
\bar{\nu}_\tau \tau$. The event rate and the signal-to-background ratio (the
ratio of the resonant to concurrent non-resonant processes) are calculated for
each type of interaction, based on current flux limits on the diffuse neutrino
flux. Because of the low background in the neighborhood of the resonance, the
observation of only one pure muon or contained lollipop event essentially
signals discovery of the resonance, even if the expected event numbers are
small. We also evaluate the total event rates of the Glashow resonance from the
extra-galactic diffuse neutrino flux and emphasize its utility as a discovery
tool to enable first observations of such a flux. We find that one can expect
3.6 (0.65) events per year for a pure $pp$ ($p\gamma$) source, along with an
added contribution of 0.51 (0.21) from non-resonant events. We also give
results as a function of the ratio of $pp$ vs $p\gamma$ sources.",1108.3163v2
2011-10-12,How terrestrial planets traverse spin-orbit resonances: A camel goes through a needle's eye,"The dynamical evolution of terrestrial planets resembling Mercury in the
vicinity of spin-orbit resonances is investigated using comprehensive harmonic
expansions of the tidal torque taking into account the frequency-dependent
quality factors and Love numbers. The torque equations are integrated
numerically with a small step in time, includng the oscillating triaxial torque
components but neglecting the layered structure of the planet and assuming a
zero obliquity. We find that a Mercury-like planet with its current value of
orbital eccentricity (0.2056) is always captured in the 3:2 resonance. The
probability of capture in the higher 2:1 resonance is approximately 0.23. These
results are confirmed by a semi-analytical estimation of capture probabilities
as functions of eccentricity for both prograde and retrograde evolution of spin
rate. As follows from analysis of equilibrium torques, entrapment in the 3:2
resonance is inevitable at eccentricities between 0.2 and 0.41. Considering the
phase space parameters at the times of periastron, the range of spin rates and
phase angles, for which an immediate resonance passage is triggered, is very
narrow, and yet, a planet like Mercury rarely fails to align itself into this
state of unstable equilibrium before it traverses the 2:1 resonance.",1110.2658v3
2012-07-13,Dissipation in planar resonant planetary systems,"Close-in planetary systems detected by the Kepler mission present an excess
of periods ratio that are just slightly larger than some low order resonant
values. This feature occurs naturally when resonant couples undergo dissipation
that damps the eccentricities. However, the resonant angles appear to librate
at the end of the migration process, which is often believed to be an evidence
that the systems remain in resonance.
  Here we provide an analytical model for the dissipation in resonant planetary
systems valid for low eccentricities. We confirm that dissipation accounts for
an excess of pairs that lie just aside from the nominal periods ratios, as
observed by the Kepler mission. In addition, by a global analysis of the phase
space of the problem, we demonstrate that these final pairs are non-resonant.
Indeed, the separatrices that exist in the resonant systems disappear with the
dissipation, and remains only a circulation of the orbits around a single
elliptical fixed point. Furthermore, the apparent libration of the resonant
angles can be explained using the classical secular averaging method. We show
that this artifact is only due to the severe damping of the amplitudes of the
eigenmodes in the secular motion.",1207.3171v2
2012-07-27,"Limits on orbit crossing planetesimals in the resonant multiple planet system, KOI-730","A fraction of multiple planet candidate systems discovered from transits by
the Kepler mission contain pairs of planet candidates that are in orbital
resonance or are spaced slightly too far apart to be in resonance. We focus
here on the four planet system, KOI 730, that has planet periods satisfying the
ratios 8:6:4:3. By numerically integrating four planets initially in this
resonant configuration in proximity to an initially exterior cold planetesimal
disk, we find that of the order of a Mars mass of planet-orbit-crossing
planetesimals is sufficient to pull this system out of resonance. Approximately
one Earth mass of planet-orbit-crossing planetesimals increases the
interplanetary spacings sufficiently to resemble the multiple planet candidate
Kepler systems that lie just outside of resonance. This suggests that the
closely spaced multiple planet Kepler systems, host only low mass debris disks
or their debris disks have been extremely stable. We find that the planetary
inclinations increase as a function of the mass in planetesimals that have
crossed the orbits of the planets. If systems are left at zero inclination and
in resonant chains after depletion of the gas disk then we would expect a
correlation between distance to resonance and mutual planetary inclinations.
This may make it possible to differentiate between dynamical mechanisms that
account for the fraction of multiple planet systems just outside of resonance.",1207.6601v1
2013-03-14,Frequency preference in two-dimensional neural models: a linear analysis of the interaction between resonant and amplifying currents,"Many neuron types exhibit preferred frequency responses in their voltage
amplitude (resonance) or phase shift to subthreshold oscillatory currents, but
the effect of biophysical parameters on these properties is not well
understood. We propose a general framework to analyze the role of different
ionic currents and their interactions in shaping the properties of impedance
amplitude and phase in linearized biophysical models and demonstrate this
approach in a two-dimensional linear model with two effective conductances gL
and g1. We compute the key attributes of impedance and phase (resonance
frequency and amplitude, zero-phase frequency, selectivity, etc.) in the gL-g1
parameter space. Using these attribute diagrams we identify two basic
mechanisms for the generation of resonance: an increase in the resonance
amplitude as g1 increases while the overall impedance is decreased, and an
increase in the maximal impedance, without any change in the input resistance,
as the ionic current time constant increases. We use the attribute diagrams to
analyze resonance and phase of the linearizations of two biophysical models
that include resonant (Ih or slow potassium) and amplifying currents
(persistent sodium). In the absence of amplifying currents, the two models
behave similarly as the conductances of the resonant currents is increased
whereas, with the amplifying current present, the two models have qualitatively
opposite responses. This work provides a general method for decoding the effect
of biophysical parameters on linear membrane resonance and phase by tracking
trajectories, parametrized by the relevant biophysical parameter, in
pre-constructed attribute diagrams.",1303.3483v1
2013-07-24,A census of transient orbital resonances encountered during binary inspiral,"Transient orbital resonances have recently been identified as potentially
important to the inspiral of small bodies into large black holes. These
resonances occur as the inspiral evolves through moments in which two
fundamental orbital frequencies, $\Omega_\theta$ and $\Omega_r$, are in a small
integer ratio to one another. Previous work has demonstrated that a binary's
parameters are ""kicked"" each time the inspiral passes through a resonance,
changing the orbit's characteristics relative to a model that neglects resonant
effects. In this paper, we use exact Kerr geodesics coupled to an accurate but
approximate model of inspiral to survey orbital parameter space and estimate
how commonly one encounters long-lived orbital resonances. We find that the
most important resonances last for a few hundred orbital cycles at mass ratio
$10^{-6}$, and that resonances are almost certain to occur during the time that
a large mass ratio binary would be a target of gravitational-wave observations.
Resonances appear to be ubiquitous in large mass ratio inspiral, and to last
long enough that they are likely to affect binary evolution in observationally
important ways.",1307.6483v2
2013-07-30,Condition for Capture into First-order Mean Motion Resonances and Application to Constraints on Origin of Resonant Systems,"We investigate the condition for capture into first-order mean motion
resonances using numerical simulations with a wide range of various parameters.
In particular, we focus on deriving the critical migration timescale for
capture into the 2:1 resonance; additional numerical experiments for closely
spaced resonances (e.g., 3:2) are also performed. We find that the critical
migration timescale is determined by the planet-to-stellar mass ratio, and its
dependence exhibits power-law behavior with index -4/3. This dependence is also
supported by simple analytic arguments. We also find that the critical
migration timescale for systems with equal-mass bodies is shorter than that in
the restricted problem; for instance, for the 2:1 resonance between two
equal-mass bodies, the critical timescale decreases by a factor of 10. In
addition, using the obtained formula, the origin of observed systems that
include first-order commensurabilities is constrained. Assuming that pairs of
planets originally form well separated from each other and then undergo
convergent migration and are captured in resonances, it is possible that a
number of exoplanets experienced rapid orbital migration. For systems in
closely spaced resonances, the differential migration timescale between the
resonant pair can be constrained well; it is further suggested that several
exoplanets underwent migration that can equal or even exceed the type I
migration rate predicted by the linear theory. This implies that some of them
may have formed in situ. Future observations and the use of our model will
allow us to statistically determine the typical migration speed in a
protoplanetary disk.",1307.7776v1
2013-12-29,A cavity-Cooper pair transistor scheme for investigating quantum optomechanics in the ultra-strong coupling regime,"We propose a scheme involving a Cooper pair transistor (CPT) embedded in a
superconducting microwave cavity, where the CPT serves as a charge tunable
quantum inductor to facilitate ultra-strong coupling between photons in the
cavity and a nano- to meso-scale mechanical resonator. The mechanical resonator
is capacitively coupled to the CPT, such that mechanical displacements of the
resonator cause a shift in the CPT inductance and hence the cavity's resonant
frequency. The amplification provided by the CPT is sufficient for the zero
point motion of the mechanical resonator alone to cause a significant change in
the cavity resonance. Conversely, a single photon in the cavity causes a shift
in the mechanical resonator position on the order of its zero point motion. As
a result, the cavity-Cooper pair transistor (cCPT) coupled to a mechanical
resonator will be able to access a regime in which single photons can affect
single phonons and vice versa. Realizing this ultra-strong coupling regime will
facilitate the creation of non-classical states of the mechanical resonator, as
well as the means to accurately characterize such states by measuring the
cavity photon field.",1312.7521v1
2014-11-10,Formation and evolution of the two 4/3 resonant giants planets in HD 200946,"It has been suggested that HD 200964 is the first exoplanetary system with
two Jovian planets evolving in the 4/3 mean- motion resonance. Previous
scenarios to simulate the formation of two giant planets in the stable 4/3
resonance configuration have failed. Moreover, the orbital parameters available
in the literature point out an unstable configuration of the planetary pair.
  The purpose of this paper is i) to determine the orbits of the planets from
the RV measurements and update the value of the stellar mass (1.57 M), ii) to
analyse the stability of the planetary evolution in the vicinity and inside the
4/3 MMR, and iii) to elaborate a possible scenario for the formation of systems
in the 4/3 MMR.
  The results of the formation simulations are able to very closely reproduce
the 4/3 resonant dynamics of the best-fit config- uration obtained in this
paper. Moreover, the confidence interval of the fit matches well with the very
narrow stable region of the 4/3 mean-motion resonance. The formation process of
the HD 200964 system is very sensitive to the planetary masses and
protoplanetary disk parameters. Only a thin, flat disk allows the embryo-sized
planets to reach the 4/3 resonant configuration. The stable evolution of the
resonant planets is also sensitive to the mass of the central star, because of
overlapping high-order resonances inside the 4/3 resonance. Regardless of the
very narrow domain of stable motion, the confidence interval of our fit closely
matches the stability area.",1411.2496v1
2015-03-25,Theory of Optical Leaky-Wave Antenna Integrated in a Ring Resonator for Radiation Control,"The integration of a leaky-wave antenna with a ring resonator is presented
using analytical guided wave models. The device consists of a ring resonator
fed by a directional coupler, where the ring resonator path includes a
leaky-wave antenna segment. The resonator integration provides two main
advantages: the high-quality factor ensures effective control of radiation
intensity by controlling the resonance conditions and the efficient radiation
from a leaky-wave antenna even when its length is much smaller than the
propagation length of the leaky wave. We devise an analytical model of the
guided wave propagation along a directional coupler and the ring resonator path
including the antenna and non-radiating segments. The trade-offs regarding the
quality factor of resonance and the antenna efficiency of such a design is
reported in terms of the coupler parameters, leaky-wave constant and radiation
length. Finally a CMOS-compatible OLWA design suitable for the ring resonator
integration is designed where Silicon is utilized as the waveguide material for
a possible electronic control of radiation intensity. The simulation results
together with the analytical model show that slight variations in the
leaky-wave's propagation constant, realized through excitation of excess
carriers in Si domain, is sufficient to control the far-field radiation
modulation with high extinction ratio.",1503.07515v1
2016-03-16,Secular resonances between bodies on close orbits: a case study of the Himalia prograde group of jovian irregular satellites,"The gravitational interaction between two objects on similar orbits can
effect noticeable changes in the orbital evolution even if the ratio of their
masses to that of the central body is vanishingly small. Christou (2005)
observed an occasional resonant lock in the differential node $\Delta \Omega$
between two members in the Himalia irregular satellite group of Jupiter in the
$N$-body simulations (corresponding mass ratio $\sim 10^{-9}$). Using a
semianalytical approach, we have reproduced this phenomenon. We also
demonstrate the existence of two additional types of resonance, involving angle
differences $\Delta\omega$ and $\Delta (\Omega+\varpi)$ between two group
members. These resonances cause secular oscillations in eccentricity and/or
inclination on timescales $\sim$ 1 Myr. We locate these resonances in $(a,e,i)$
space and analyse their topological structure. In subsequent $N$-body
simulations, we confirm these three resonances and find a fourth one involving
$\Delta \varpi$. In addition, we study the occurrence rates and the stability
of the four resonances from a statistical perspective by integrating 1000 test
particles for 100 Myr. We find $\sim 10-30$ librators for each of the
resonances. Particularly, the nodal resonance found by Christou is the most
stable: 2 particles are observed to stay in libration for the entire
integration.",1603.05125v1
2017-02-03,Strong interaction between graphene layer and Fano resonance in terahertz metamaterials,"Graphene has emerged as a promising building block in the modern optics and
optoelectronics due to its novel optical and electrical properties. In the
mid-infrared and terahertz (THz) regime, graphene behaves like metals and
supports surface plasmon resonances (SPRs). Moreover, the continuously tunable
conductivity of graphene enables active SPRs and gives rise to a range of
active applications. However, the interaction between graphene and metal-based
resonant metamaterials has not been fully understood. In this work, a
simulation investigation on the interaction between the graphene layer and THz
resonances supported by the two-gap split ring metamaterials is systematically
conducted. The simulation results show that the graphene layer can
substantially reduce the Fano resonance and even switch it off, while leave the
dipole resonance nearly unaffected, which phenomenon is well explained with the
high conductivity of graphene. With the manipulation of graphene conductivity
via altering its Fermi energy or layer number, the amplitude of the Fano
resonance can be modulated. The tunable Fano resonance here together with the
underlying physical mechanism can be strategically important in designing
active metal-graphene hybrid metamaterials. In addition, the ""sensitivity"" to
the graphene layer of the Fano resonance is also highly appreciated in the
field of ultrasensitive sensing, where the novel physical mechanism can be
employed in sensing other graphene-like two-dimensional (2D) materials or
biomolecules with the high conductivity.",1702.00920v2
2017-08-04,Resonance free regions and non-Hermitian spectral optimization for Schrödinger point interactions,"Resonances of Schr\""odinger Hamiltonians with point interactions are
considered. The main object under the study is the resonance free region under
the assumption that the centers, where the point interactions are located, are
known and the associated 'strength' parameters are unknown and allowed to bear
additional dissipative effects. To this end we consider the boundary of the
resonance free region as a Pareto optimal frontier and study the corresponding
optimization problem for resonances. It is shown that upper logarithmic bound
on resonances can be made uniform with respect to the strength parameters. The
necessary conditions on optimality are obtained in terms of first principal
minors of the characteristic determinant. We demonstrate the applicability of
these optimality conditions on the case of 4 equidistant centers by computing
explicitly the resonances of minimal decay for all frequencies. This example
shows that a resonance of minimal decay is not necessarily simple, and in some
cases it is generated by an infinite family of feasible resonators.",1708.01334v2
2017-08-16,Optical absorption preceding resonant double photoionization of aromatic hydrocarbons hydrocarbons,"We analyze resonances in the double photoionization of a variety of aromatic
hydrocarbons. The resonances reflect the breakup of quasi-bound electron pairs.
The basic premise of this paper is that there is a direct connection between
the quasi-bound pairs and resonant peaks in the optical absorption that are
associated with doubly occupied sites on the perimeter and inside the perimeter
of the molecule. The optical absorption leading to the high-energy resonance
(approximately 40 eV), calculated from a many-site one-dimensional Hubbard
model, has a peak at U, the electrostatic interaction energy for two electrons
with antiparallel spins on the same carbon atom. In the model, there are also
two satellites whose separation from the main resonance is approximately +/-10
eV suggesting that unresolved satellite structure may be contributing to the
linewidth of the resonant peak. The low energy resonances (approximately 10 eV)
involve carbon atoms located inside the perimeter, a configuration present only
in pyrene and coronene (among the hydrocarbons studied). In the case of pyrene,
which has two carbon atoms inside the perimeter, we employ a two-site Hubbard
model to characterize the absorption leading to the quasi-bound state. A brief
analysis of the double photoionization resonance of the heterocyclic inorganic
molecule 1,3,5-triazine presented. We also discuss recent results for the
double photoionization of the cyclic inorganic molecule tribromoborazine and
the organic molecules furan, pyrrole, selenophene, and thiophene where the 2+
ion concentration varies linearly with the difference between the photon energy
and the threshold energy. A theory for the linear behavior is outlined.",1708.05049v1
2018-11-14,Spin detection with a micromechanical trampoline: Towards magnetic resonance microscopy harnessing cavity optomechanics,"We explore the prospects and benefits of combining the techniques of cavity
optomechanics with efforts to image spins using magnetic resonance force
microscopy (MRFM). In particular, we focus on a common mechanical resonator
used in cavity optomechanics -- high-stress stoichiometric silicon nitride
(Si$_3$N$_4$) membranes. We present experimental work with a trampoline
membrane resonator that has a quality factor above $10^6$ and an order of
magnitude lower mass than a comparable standard membrane resonators. Such
high-stress resonators are on a trajectory to reach 0.1
$\rm{aN}/\sqrt{\rm{Hz}}$ force sensitivities at MHz frequencies by using
techniques such as soft clamping and phononic-crystal control of acoustic
radiation in combination with cryogenic cooling. We present a demonstration of
force-detected electron spin resonance of an ensemble at room temperature using
the trampoline resonators functionalized with a magnetic grain. We discuss
prospects for combining such a resonator with an integrated Fabry-Perot cavity
readout at cryogenic temperatures, and provide ideas for future impacts of
membrane cavity optomechanical devices on MRFM of nuclear spins.",1811.05718v2
2018-11-30,An analytical approach to the field amplification and particle production by parametric resonance during inflation and reheating,"Field amplification and particle production due to parametric resonance are
highly nontrivial predictions of quantum fields that couple to an oscillating
source during inflation and reheating. Understanding this two effects is
crucial for the connection between the resonance phenomenon and precise
observational data. In this paper, we give a general and analytic analysis of
parametric resonance of relevant field modes evolving during inflation and
reheating by using the uniform asymptotic approximation. This analysis can
provide a clear and quantitative explanation for the field amplification and
particle production during the resonance. The potential applications of our
results to several examples, including sound resonance during inflation,
particle productions during reheating, and parametric resonance due to
self-resonance potentials, have also been explored. The formalism developed in
this paper is also applicable to parametric resonance in a broad areas of
modern science.",1811.12612v3
2019-05-27,Modulation-resonance mechanism for surface waves in a two-layer fluid system,"We propose a Boussinesq-type model to study the surface/interfacial wave
manifestation of an underlying, slowly-varying, long-wavelength, baroclinic
flow in a two-layer, density-stratified system. The results of our model show
numerically that, under strong nonlinearity, surface waves, with their typical
wavenumber being the resonant $k_{\mathrm{res}}$, can be generated locally at
the leading edge of the underlying slowly-varying, long-wavelength baroclinic
flow. Here, the resonant $k_{\mathrm{res}}$ satisfies the class 3 triad
resonance condition among two short-mode waves and one long-mode wave in which
all waves propagate in the same direction. Moreover, when the slope of the
baroclinic flow is sufficiently small, only one spatially-localized
large-amplitude surface wave packet can be generated at the leading edge. This
localized surface wave packet becomes high in amplitude and large in group
velocity after the interaction with its surrounding waves. These results are
qualitatively consistent with various experimental observations including
resonant surface waves at the leading edge of an internal wave. Subsequently,
we propose a mechanism, referred to as the modulation-resonance mechanism,
underlying these surface phenomena, based on our numerical simulations. The
proposed modulation-resonance mechanism combines the linear modulation
(ray-based) theory for the spatiotemporal asymmetric behavior of surface waves
and the nonlinear class 3 triad resonance theory for the energy focusing of
surface waves around the resonant wavenumber $k_{\mathrm{res}}$ in Fourier
space.",1905.11344v1
2017-04-11,Secular resonances between bodies on close orbits II: prograde and retrograde orbits for irregular satellites,"In extending the analysis of the four secular resonances between close orbits
in Li and Christou (Celest Mech Dyn Astron 125:133-160, 2016) (Paper I), we
generalise the semianalytical model so that it applies to both prograde and
retrograde orbits with a one to one map between the resonances in the two
regimes. We propose the general form of the critical angle to be a linear
combination of apsidal and nodal differences between the two orbits $ b_1
\Delta \varpi + b_2 \Delta \Omega $, forming a collection of secular resonances
in which the ones studied in Paper I are among the strongest. Test of the model
in the orbital vicinity of massive satellites with physical and orbital
parameters similar to those of the irregular satellites Himalia at Jupiter and
Phoebe at Saturn shows that $> 20\%$ and $> 40\%$ of phase space is affected by
these resonances, respectively. The survivability of the resonances is
confirmed using numerical integration of the full Newtonian equations of
motion. We observe that the lowest order resonances with $b_1+|b_2|\le 3$
persist, while even higher order resonances, up to $b_1+|b_2|\ge 7$, survive.
Depending on the mass, between $10\%-60\%$ of the integrated test particles are
captured in these secular resonances, in agreement with the phase space
analysis in the semianalytical model.",1704.03332v1
2017-04-19,The long-term evolution of known resonant trans-Neptunian objects,"Aims. Numerous trans-Neptunian objects are known to be in mean-motion
resonance with Neptune. We aim to describe their long-term orbital evolution
(both past and future) by means of a one-degree-of-freedom secular model. In
this paper, we focus only on objects with a semi-major axis larger than 50
astronomical units (au).
  Methods. For each resonant object considered, a 500 000-year numerical
integration is performed. The output is digitally filtered to get the
parameters of the resonant secular model. Their long-term (Giga-year) orbital
evolution is then represented by the level curves of the secular Hamiltonian.
  Results. For the majority of objects considered, the mean-motion resonance
has little impact on the long-term trajectories (the secular dynamics is
similar to a non-resonant one). However, a subset of objects is strongly
affected by the resonance, producing moderately-high-amplitude oscillations of
the perihelion distance and/or libration of the argument of perihelion around a
fixed centre. Moreover, the high perihelion distance of the object 2015 FJ345
is plainly explained by long-term resonant dynamics, allowing us to also deduce
its orbital elements at the time of capture in resonance (at least 15 million
years ago). The same type of past evolution is expected for 2014 FZ71.",1704.05881v1
2017-04-25,Avoiding resonance capture in multi-planet extrasolar systems,"A commonly noted feature of the population of multi-planet extrasolar systems
is the rarity of planet pairs in low-order mean-motion resonances. We revisit
the physics of resonance capture via convergent disk-driven migration. We point
out that for planet spacings typical of stable configurations for Kepler
systems, the planets can routinely maintain a small but nonzero eccentricity
due to gravitational perturbations from their neighbors. Together with the
upper limit on the migration rate needed for capture, the finite eccentricity
can make resonance capture difficult or impossible in Sun-like systems for
planets smaller than ~Neptune-sized. This mass limit on efficient capture is
broadly consistent with observed exoplanet pairs that have mass determinations:
of pairs with the heavier planet exterior to the lighter planet -- which would
have been undergoing convergent migration in their disks -- those in or nearly
in resonance are much more likely to have total mass greater than two Neptune
masses than to have smaller masses. The agreement suggests that the observed
paucity of resonant pairs around sun-like stars may simply arise from a small
resonance capture probability for lower-mass planets. Planet pairs that thereby
avoid resonance capture are much less likely to collide in an eventual close
approach than to simply migrate past one another to become a divergently
migrating pair with the lighter planet exterior. For systems around M stars we
expect resonant pairs to be much more common, since there the minimum mass
threshhold for efficient capture is about an Earth mass.",1704.07836v2
2011-11-16,Optical tuning and ultrafast dynamics of high-temperature superconducting terahertz metamaterials,"Through the integration of semiconductors or complex oxides into metal
resonators, tunable metamaterials have been achieved by a change of environment
using an external stimulus. Metals provide high conductivity to realize a
strong resonant response in metamaterials; however, they contribute very little
to the tunability. The complex conductivity in high-temperature superconducting
films is highly sensitive to external perturbations, which provides new
opportunities in achieving tunable metamaterials resulting directly from the
resonant elements. Here we demonstrate ultrafast dynamical tuning of resonance
in the terahertz (THz) frequency range in YBa_2Cu_3O_7-\delta (YBCO) split-ring
resonator arrays excited by near-infrared femtosecond laser pulses. The
photoexcitation breaks the superconducting Cooper pairs to create the
quasiparticle state. This dramatically modifies the imaginary part of the
complex conductivity and consequently the metamaterial resonance in an
ultrafast timescale. We observed resonance switching accompanied with a wide
range frequency tuning as a function of photoexcitation fluence, which also
strongly depend on the nano-scale thickness of the superconducting films. All
of our experimental results are well reproduced through calculations using an
analytical model, which takes into account the SRR resistance and kinetic
inductance contributed from the complex conductivity of YBCO films. The
theoretical calculations reveal that the increasing SRR resistance upon
increasing photoexcitation fluence is responsible for the reduction of
resonance strength, and both the resistance and kinetic inductance contribute
to the tuning of resonance frequency.",1111.3917v1
2017-09-30,Multiple critical coupling and sensing in a microresonator-waveguide system,"We study the optical transmission of a waveguide that is side-coupled to a
high-$Q$ circular microresonator. The coupling is critical if the intrinsic
resonator losses equate the coupling losses to the waveguide. When this
happens, the transmittance of the waveguide displays resonance dips with
maximal depth as the frequency is swept through the resonators resonances. We
show that multiple configurations, parameterised by the minimal distance
between the resonator and the waveguide, can lead to critical coupling. Indeed,
for a sufficiently large resonator radius, the flow of power between the
waveguide and the resonator can change sign several times within a single pass.
This leads to an oscillatory coupling parameter as a function of the separation
distance. As a result, multiple geometrical configurations can lead to critical
coupling, even if the waveguide lies in the equatorial plane of the resonator.
These results are explained using coupled-mode theory and full wave numerical
simulations. In the vicinity of secondary or higher-order critical coupling,
the depth of the transmittance dip is very sensitive to the environment. We
discuss how this effect can be exploited for sensing purpose. Alternatively, by
actively controlling the environment in the secondary critical configuration,
the waveguide/resonator system can be driven as an optical switch.",1710.00178v1
2018-09-13,Kozai-Lidov Mechanism inside Retrograde Mean Motion Resonances,"As the discoveries of more minor bodies in retrograde resonances with giant
planets, such as 2015 BZ509 and 2006 RJ2, our curiosity about the Kozai-Lidov
dynamics inside the retrograde resonance has been sparked. In this study, we
focus on the 3D retrograde resonance problem and investigate how the resonant
dynamics of a minor body impacts on its own Kozai-Lidov cycle. Firstly we
deduce the action-angle variables and canonical transformations that deal with
the retrograde orbit specifically. After obtaining the dominant Hamiltonian of
this problem, we then carry out the numerical averaging process in closed form
to generate phase-space portraits on a $e-\omega$ space. The retrograde 1:1
resonance is particularly scrutinized in detail, and numerical results from a
CRTBP model shows a great agreement with the our semi-analytical portraits. On
this basis, we inspect two real minor bodies currently trapped in retrograde
1:1 mean motion resonance. It is shown that they have different Kozai-Lidov
states, which can be used to analyze the stability of their unique resonances.
In the end, we further inspect the Kozai-Lidov dynamics inside the 2:1 and 2:5
retrograde resonance, and find distinct dynamical bifurcations of equilibrium
points on phase-space portraits.",1809.04959v1
2018-09-17,Three Pathways for Observed Resonant Chains,"A question driving many studies is whether the thousands of exoplanets known
today typically formed where we observe them or formed further out in the disk
and migrated in. Early discoveries of giant exoplanets orbiting near their host
stars and exoplanets in or near mean motion resonances were interpreted as
evidence for migration and its crucial role in the beginnings of planetary
systems. long-scale migration has been invoked to explain systems of planets in
mean motion resonant chains consisting of three or more planets linked by
integer period ratios. However, recent studies have reproduced specific
resonant chains in systems via short-scale migration, and eccentricity damping
has been shown to capture planets into resonant chains. We investigate whether
the observed resonant chains in Kepler-80, Kepler-223, Kepler-60, and
TRAPPIST-1 can be established through long-scale migration, short-scale
migration, and/or only eccentricity damping by running suites of N-body
simulations. We find that, for each system, all three mechanisms are able to
reproduce the observed resonant chains. long-scale migration is not the only
plausible explanation for resonant chains in these systems, and resonant chains
are potentially compatible with in situ formation.",1809.06443v2
2018-09-22,Resonances of unbound quantum many-body systems of nuclei,"Resonance is a general phenomenon which can happen in classic or quantum
systems. An unbound many-body quantum system can undergo a self-resonant
process. It has long been a challenge how to describe unbound many-body quantum
systems in resonances. In this paper, we develop a novel first-principles
method that is capable of describing resonant quantum systems. We exploit, for
the first time, the advanced in-medium similarity renormalization group (IMSRG)
in the complex-energy Gamow-Berggren representation with resonance and
non-resonant continuum. The ab initio Gamow IMSRG has broad applications, such
as, to the electromagnetic-interaction systems of atoms, molecules or quantum
dots, and strong-interaction atomic nuclei. In the present work, we apply the
method to loosely bound or unbound nuclear systems. Carbon and oxygen isotopes
have been investigated with an optimized chiral effective field theory
potential. The resonant states observed in neutron-rich 22O and 24O are well
reproduced. The loose halo structure of the Borromean nucleus 22C is clearly
seen by the density calculation, in which the continuum s-waves play a crucial
role. Further, we predict low-lying resonant excited states in 22C. This method
provides rigorous and tractable theoretical calculations for weakly-bound or
unbound open quantum systems.",1809.08405v1
2018-09-25,Connection between asymptotic normalization coefficients and resonance widths of mirror states,"Asymptotic normalization coefficients (ANCs) are fundamental nuclear
constants playing important role in nuclear reactions, nuclear structure and
nuclear astrophysics. In this paper a connection between ANCs and resonance
widths of the mirror states is established. Using Pinkston-Satchler equation
the ratio for resonance widths and ANCs of mirror nuclei is obtained in terms
of the Wronskians from the radial overlap functions and regular solutions of
the two-body Schr\""odinger equation with the short-range interaction excluded.
This ratio allows one to use microscopic overlap functions for mirror nuclei in
the internal region, where they are the most accurate, to correctly predict the
ratio of the resonance widths and ANCs for mirror nuclei, which determine the
amplitudes of the tails of the overlap functions. If the microscopic overlap
functions are not available one can express the Wronskians for the resonances
and mirror bound states in terms of the corresponding mirror two-body
potential-model wave functions. A further simplification of the Wronskians
ratio leads to the equation for the ratio of the resonance widths and mirror
ANCs, which is expressed in terms of the ratio of the two-body Coulomb
scattering wave functions at the resonance energy and at the binding energy [N.
K. Timofeyuk, R. C. Johnson, and A. M. Mukhamedzhanov, Phys. Rev. Lett. {\bf
91}, 232501 (2003]. In this paper calculations of the ratios of resonance
widths and mirror ANCs for different nuclei are presented. From this ratio one
can determine the resonance width if the mirror ANC is known and vice versa.
Comparison with available experimental ratios are done.",1809.09980v1
2018-10-27,Photoacoustics Modelling using Amplitude Mode Expansion Method in a Multiscale T-cell Resonator,"The photoacoustic (PA) effect consisting of the generation of an acoustic
signal based on the absorption of light has already demonstrated its potential
for various spectroscopic applications for both gaseous and solid samples. The
signal produced during photoacoustic spectroscopy (PAS) measurement is,
however, usually weak and needs to be amplified. This is achieved by using a
photoacoustic cell resonator where acoustic resonances are utilized to
significantly boost the signal. Therefore, a PA resonator has a significant
role in PAS measurement set-ups. When designing or optimizing a new PA
resonator, numerical methods are generally used to simulate the photoacoustic
signal generation. In this paper, the amplitude mode expansion (AME) method is
presented as a quick and accurate simulation tool. The method is used to
simulate the photoacoustic signal in a multi-scale T-cell resonator over a wide
frequency range. The AME method is based on eigenmode expansion and
introduction of losses by quality factors. The AME simulation results are
compared and analyzed against the results from the viscothermal method.
Reasonably good agreement is obtained between the two methods. However, small
frequency shifts in the resonances of the AME method are noted. The shifts are
attributed to the location of the dominant mode within the T-cell. The
viscothermal method is considered the most accurate method for simulating the
photoacoustic signal in small resonators. However, it is computationally very
demanding. The AME method provides a much faster simulation alternative. This
is particularly useful in the design and optimization of photoacoustic
resonators where numerical methods are preferred over experimental measurements
due to their speed and low cost.",1810.11618v1
2019-09-15,Evaluation of surface roughness of metal films using plasmonic Fano resonance in attenuated total reflection,"Attenuated total reflection (ATR) by surface plasmon polariton (SPP) is a
method for evaluating the dispersion relation of SPP from the position of a dip
in the reflection spectrum. However, recent studies have shown that the dips
are displaced from SPP resonance because they are produced by a type of Fano
resonance, i.e., the interference between the resonant reflection process
accompanied by resonant excitation of SPP and the direct reflection process
without resonant excitation. This result suggests that the system properties
difficult to be achieved in the dispersion relation of SPP can be characterized
using the ATR method. In this study, we investigate the effect of surface
roughness due to nanosized dimples created in the initial stage of pitting
corrosion on the ATR spectrum, from the viewpoint of Fano resonance. Using the
temporal coupled-mode method, it is shown that the Fano resonance in ATR is
caused by the phase change of direct reflection because of the absorption on
the metal surface, and the spectral shape is determined by this phase, along
with the ratio of the external (radiative) decay rate to the total decay rate
of the resonant mode. Moreover, it is clarified that the internal and external
decay rates extracted from the ATR spectrum provide information on corrosion,
such as the effective thickness of the metal film and the randomness in dimple
distribution.",1909.06746v1
2019-09-25,Coherent phonon dynamics in spatially separated graphene mechanical resonators,"Vibrational modes in mechanical resonators provide a promising candidate to
interface and manipulate classical and quantum information. The observation of
coherent dynamics between distant mechanical resonators can be a key step
towards scalable phonon-based applications. Here we report tunable coherent
phonon dynamics with an architecture comprising three graphene mechanical
resonators coupled in series, where all resonators can be manipulated by
electrical signals on control gates. We demonstrate coherent Rabi oscillations
between spatially separated resonators indirectly coupled via an intermediate
resonator serving as a phonon cavity. The Rabi frequency fits well with the
microwave burst power on the control gate. We also observe Ramsey interference,
where the oscillation frequency corresponds to the indirect coupling strength
between these resonators. Such coherent processes indicate that information
encoded in vibrational modes can be transferred and stored between spatially
separated resonators, which can open the venue of on-demand phonon-based
information processing.",1909.11311v2
2019-10-17,Spontaneous superharmonic internal wave generation by modal interactions in uniform and nonuniform stratifications,"Triadic resonance is one mechanism via which internal waves dissipate their
energy, often at locations away from their generation sites. In this paper, we
perform a combined theoretical and numerical study of triadic resonance in
internal wave modes in a finite-depth ocean with background rotation and an
arbitrary stratification profile. The spatial evolution of the modal amplitudes
within a resonant triad are first derived based on the requirement that the
nonlinear solution at leading order cannot diverge. The amplitude evolution
equations are then numerically solved for two different cases: (i) modes 1 and
2 at a specific frequency ({\omega_0}) in triadic resonance with the mode-1
superharmonic wave (2{\omega_0}) in a uniform stratification, and (ii) a
self-interacting mode-3 at a specific frequency {\omega_0} in triadic resonance
with the mode-2 (2{\omega_0}) in a nonuniform stratification representative of
the ocean. Quantitative estimates of energy transfer rates within the resonant
triad show that superharmonic wave generation resulting from modal interactions
should be an important consideration alongside other triadic resonances like
parametric subharmonic instability (PSI). Remarkably, in case (ii), the
amplitude evolution equations suggest that any initial energy in mode-3 at
{\omega_0} would get permanently transferred to mode-2 at frequency
2{\omega_0}. Direct numerical simulations (DNS) are then performed to show the
spontaneous generation of superharmonic internal waves resulting from modal
interactions in the aforementioned two cases, and quantitatively validate the
initial spatial evolution of the wave field predicted by the amplitude
evolution equations. DNS at off-resonant frequencies are used to identify the
range of primary wave frequencies (around the resonant frequency) over which
spontaneous superharmonic wave generation occurs.",1910.07777v1
2020-04-03,Resonant effect at the ultrarelativistic electron-positron pairs production by gamma quanta in the field of a nucleus and a pulsed light wave,"Resonant electron-positron pair production by a high-energy gamma quantum in
the field of a nucleus and a quasi-monochromatic laser wave was theoretically
studied. Under the resonant condition an intermediate virtual electron
(positron) in the laser field becomes a real particle. Due to that fact the
initial process of the second order in the fine structure constant in a laser
field effectively reduces into two successive processes of the first order: the
laser-stimulated Breit-Wheeler process and the laser-assisted process of an
intermediate electron (positron) scattering by a nucleus. It is shown that
there is a threshold energy for the initial gamma quantum, which significantly
depends on the number of absorbed photons of a wave. In the resonant condition
the electron-positron pair energy is determined by the outgoing angle of a
positron (for the channel A) or an electron (for the channel B) relative to the
initial gamma quantum momentum. The differential cross sections for the first
few resonances with simultaneous registration of the energy and the outgoing
angle of a positron or an electron were obtained. For the initial gamma quantum
energy ${\omega_i} = 125\;{\rm{GeV}}$ the resonant energies of an
electron-positron pair for the case of first three resonances can be measured
with a very high magnitude of the differential cross section: from $ \sim
{10^{13}}$ for the first resonance to $ \sim {10^8}$ (in the units of $\alpha
{Z^2}r_e^2$) for the third resonance.",2004.01530v1
2020-04-21,Hybridization of Epsilon-Near-Zero Modes via Resonant Tunneling in Layered Metal/Insulator Double Nanocavities,"The coupling between multiple nanocavities in close vicinity leads to
hybridization of their modes. Stacked Metal/Insulator/Metal (MIM) nanocavities
constitute a highly versatile and very interesting model system to study and
engineer such mode coupling, since they can be realized by lithography-free
fabrication methods with fine control on the optical and geometrical
parameters. The resonant modes of such MIM cavities are epsilon-near-zero (ENZ)
resonances, which are appealing for non-linear photophysics and a variety of
applications. Here we study the hybridization of ENZ resonances in MIMIM
nanocavities, obtaining a very large mode splitting reaching 0.477 eV, Q
factors of the order of 40 in the visible spectral range, and fine control on
the resonance wavelength and mode linewidth by tuning the thickness of the
dielectric and metallic layers. A semi-classical approach that analyses the
MIMIM structure as a double quantum well system allows to derive the exact
analytical dispersion relation of the ENZ resonances, achieving perfect
agreement with numerical simulations and experiments. Interestingly, the
asymmetry of the mode splitting in a symmetric MIMIM cavity is not reflected in
the classical model of coupled oscillators, which can be directly related to
quantum mechanical tunneling for the coupling of the two cavities. Interpreting
the cavity resonances as resonant tunneling modes elucidates that can be
excited without momentum matching techniques. The broad tunability of
high-quality ENZ resonances together with their strong coupling efficiency
makes such MIMIM cavities an ideal platform for exploring light-matter
interaction, for example, by integration of quantum emitters in the dielectric
layers.",2004.09913v1
2020-12-02,A complex-valued resonance model for axisymmetric screech tones in supersonic jets,"We model the resonance mechanism underpinning generation of A1 and A2 screech
tones in an under-expanded supersonic jet. Starting from the resonance model
recently proposed by \cite{mancinelli2019screech}, where the
upstream-travelling wave is a neutrally-stable guided jet mode, we here present
a more complete linear-stability-based model for screech prediction. We study
temperature and shear-layer thickness effects and show that, in order to
accurately describe the experimental data, the effect of the finite thickness
of the shear layer must be incorporated in the jet-dynamics model. We then
present an improved resonance model for screech-frequency predictions in which
both downstream- and upstream-travelling waves may have complex wavenumber and
frequency. This resonance model requires knowledge of the reflection
coefficients at the upstream and downstream locations of the resonance loop. We
explore the effect of the reflection coefficients on the resonance model and
propose an approach for their identification. The complex-mode model identifies
limited regions of frequency-flow parameter space for which the resonance loop
is amplified in time, a necessary condition for the resonance to be sustained.
This model provides an improved description of the experimental measurements.",2012.01342v2
2021-01-13,Longitudinal and transversal resonant tunneling of interacting bosons in a two-dimensional Josephson junction: Mean-field and many-body dynamics,"We unravel the out-of-equilibrium quantum dynamics of a few interacting
bosonic clouds in a two-dimensional asymmetric double-well potential at the
resonant tunneling scenario. At the single-particle level of resonant
tunneling, particles tunnel under the barrier from, typically, the ground-state
in the left well to an excited state in the right well, i.e., states of
different shapes and properties are coupled when their one-particle energies
coincide. In two spatial dimensions, two types of resonant tunneling processes
are possible, to which we refer to as longitudinal and transversal resonant
tunneling. Longitudinal resonant tunneling implies that the state in the right
well is longitudinally-excited with respect to the state in the left well,
whereas transversal resonant tunneling implies that the former is
transversely-excited with respect to the latter. We show that interaction
between bosons makes resonant tunneling phenomena in two spatial dimensions
profoundly rich, and analyze these phenomena in terms of the loss of coherence
of the junction and development of fragmentation, and coupling between
transverse and longitudinal degrees-of-freedom and excitations. To this end, a
detailed analysis of the tunneling dynamics is performed by exploring the time
evolution of a few physical quantities, namely, the survival probability,
occupation numbers of the reduced one-particle density matrix, and the
many-particle position, momentum, and angular-momentum variances. In general,
we display the impact of the transversal and longitudinal degrees-of-freedom in
the many-boson tunneling dynamics at the resonant tunneling scenarios.",2101.04959v3
2017-05-17,Tunable Super-Mode Dielectric Resonators for Axion Haloscopes,"We present frequency tuning mechanisms for dielectric resonators, which
undergo ""super-mode"" interactions as they tune. The tunable schemes are based
on dielectric materials strategically placed inside traditional cylindrical
resonant cavities, necessarily operating in Transverse Magnetic modes for use
in axion haloscopes. The first technique is based on multiple dielectric disks
with radii smaller than that of the cavity. The second scheme relies on hollow
dielectric cylinders similar to a Bragg resonator, but of different location
and dimension. In particular we engineer a significant increase in form factor
for the TM030 mode utilising a variation of a Distributed Bragg Reflector
Resonator. Additionally, we demonstrate application of traditional Distributed
Bragg Reflectors in TM modes, which may be applied to a haloscope. This is the
first demonstration of Bragg resonators applied to TM modes, as well as the
first application of super-modes to tune Bragg resonators, or haloscope
resonators. Theory and experimental results are presented showing an increase
in Q-factor and tunability due to the super-mode effect. The TM030 ring
resonator mode offers between 1 and 2-orders-of-magnitude improvement in axion
sensitivity over current conventional cavity systems and will be employed in
the forthcoming ORGAN experiment.",1705.06028v3
2017-09-24,Double-negative acoustic metamaterials,"The aim of this paper is to provide a mathematical theory for understanding
the mechanism behind the double-negative refractive index phenomenon in bubbly
fluids. The design of double-negative metamaterials generally requires the use
of two different kinds of subwavelength resonators, which may limits the
applicability of double-negative metamaterials. Herein we rely on media that
consists of only a single type of resonant element, and show how to turn the
acoustic metamaterial with a single negative effective property obtained in [H.
Ammari and H. Zhang, Effective medium theory for acoustic waves in bubbly
fluids near Minnaert resonant frequency. SIAM J. Math. Anal., 49 (2017),
3252--3276.] into a negative refractive index metamaterial, which refracts
waves negatively, hence acting as a superlens. Using bubble dimers made of two
identical bubbles, it is proved that both the effective mass density and the
bulk modulus of the bubbly fluid can be negative near the anti-resonance of the
two hybridized Minnaert resonances for a single constituent bubble dimer. A
rigorous justification of the Minnaert resonance hybridization, in the case of
a bubble dimer in a homogeneous medium, is established. The acoustic properties
of a single bubble dimer are analyzed. Asymptotic formulas for the two
hybridized Minnaert resonances are derived. Moreover, it is proved that the
bubble dimer can be approximated by a point scatterer with monopole and dipole
modes. For an appropriate volume fraction of bubble dimers with certain
conditions on their configuration, a double-negative effective medium when the
frequency is near the anti-resonance of the hybridized Minnaert resonances can
be obtained.",1709.08177v2
2017-09-29,Analysis of characteristics of Al MKID resonators,"We have prepared two kinds of Al resonators using thin films made by
evaporation or sputtering and studied temperature behavior of their quality
factors and resonance frequencies with the help of the extended Mattis-Bardeen
(M-B) equations and its approximated analytical expressions. We have found that
temperature behavior of both the internal quality factor and resonance
frequency shift measured in evaporated Al thin-film resonators are well agreed
with those calculated by the analytical expressions of the complex conductivity
given by the M-B theory. In the Al thin film resonators made by sputtering, the
internal quality factor and resonance frequency shift show a peak and a bump
near 0.17 K in the respective temperature dependence. It is found that inverse
of the internal quality factor is well approximated by a-b*log(T) below 0.15 K,
where T is the temperature. This type of temperature dependence strongly
indicates the existence of the magnetic impurity scattering of residual
quasiparticles due to the Kondo effect. It is shown that temperature dependence
of the internal quality factor and resonance frequency shift observed in the
sputtered Al resonators can be well fitted by the theory taking the Kondo
effect and kinetic inductance of the residual quasiparticles into account.",1709.10421v1
2018-03-02,"A comparative study of stochastic resonance for a model with two pathways by escape times, linear response, invariant measures and the conditional Kolmogorov-Smirnov Test","We consider stochastic resonance for a diffusion with drift given by a
potential, which has two metastable states and two pathways between them.
Depending on the direction of the forcing, the height of the two barriers, one
for each path, will either oscillate alternating or in synchronisation. We
consider a simplified model given by a continuous time Markov Chains with two
states. This was done for alternating and synchronised wells. The invariant
measures are derived for both cases and shown to be constant for the
synchronised case. A PDF for the escape time from an oscillatory potential is
studied. Methods of detecting stochastic resonance are presented, which are
linear response, signal-noise ratio, energy, out-of-phase measures, relative
entropy and entropy. A new statistical test called the conditional
Kolmogorov-Smirnov test is developed, which can be used to analyse stochastic
resonance. An explicit two dimensional potential is introduced, the critical
point structure derived and the dynamics, the invariant state and escape time
studied numerically. The six measures are unable to detect the stochastic
resonance in the case of synchronised saddles. The distribution of escape times
however not only shows a clear sign of stochastic resonance, but changing the
direction of the forcing from alternating to synchronised saddles an additional
resonance at double the forcing frequency starts to appear. The conditional KS
test reliably detects the stochastic resonance. This paper is mainly based on
the thesis ""Stochastic Resonance for a Model with Two Pathways""",1803.00880v1
2018-03-03,Stochastic Resonance for a Model with Two Pathways,"In this thesis we consider stochastic resonance for a diffusion with drift
given by a potential, which has two metastable states and two pathways between
them. Depending on the direction of the forcing the height of the two barriers,
one for each path, will either oscillate alternating or in synchronisation.
  We consider a simplified model given by discrete and continuous time Markov
Chains with two states. This was done for alternating and synchronised wells.
The invariant measures are derived for both cases and shown to be constant for
the synchronised case. A PDF for the escape time from an oscillatory potential
is reviewed.
  Methods of detecting stochastic resonance are presented, which are linear
response, signal-to-noise ratio, energy, out-of-phase measures, relative
entropy and entropy. A new statistical test called the conditional
Kolmogorov-Smirnov test is developed, which can be used to analyse stochastic
resonance.
  An explicit two dimensional potential is introduced, the critical point
structure derived and the dynamics, the invariant state and escape time studied
numerically.
  The six measures are unable to detect the stochastic resonance in the case of
synchronised saddles. The distribution of escape times however not only shows a
clear sign of stochastic resonance, but changing the direction of the forcing
from alternating to synchronised saddles an additional resonance at double the
forcing frequency starts to appear. The conditional KS test reliably detects
the stochastic resonance even for forcing quick enough and for data so sparse
that the stochastic resonance is not obvious directly from the histogram of
escape times.",1803.01209v1
2018-07-20,Low-temperature tunable radio-frequency resonator for sensitive dispersive readout of nanoelectronic devices,"We present a sensitive, tunable radio-frequency resonator designed to detect
reactive changes in nanoelectronic devices down to dilution refrigerator
temperatures. The resonator incorporates GaAs varicap diodes to allow
electrical tuning of the resonant frequency and the coupling to the input line.
We find a resonant frequency tuning range of 8.4 MHz at 55 mK that increases to
29 MHz at 1.5 K. To assess the impact on performance of different tuning
conditions, we connect a quantum dot in a silicon nanowire field-effect
transistor to the resonator, and measure changes in the device capacitance
caused by cyclic electron tunneling. At 250 mK, we obtain an equivalent charge
sensitivity of $43~\mu e / \sqrt{\text{Hz}}$ when the resonator and the line
are impedance-matched and show that this sensitivity can be further improved to
$31~\mu e / \sqrt{\text{Hz}}$ by re-tuning the resonator. We understand this
improvement by using an equivalent circuit model and demonstrate that for
maximum sensitivity to capacitance changes, in addition to impedance matching,
a high-quality resonator with low parasitic capacitance is desired.",1807.07842v2
2018-08-19,On Bragg resonances and wave triad interactions in two-layered shear flows,"The standard resonance conditions for Bragg scattering as well as weakly
nonlinear wave triads have been traditionally derived in the absence of any
background velocity. In this paper, we have studied how these resonance
conditions get modified when uniform, as well as various piecewise linear
velocity profiles, are considered for two-layered shear flows. Background
velocity can influence the resonance conditions in two ways (i) by causing
Doppler shifts, and (ii) by changing the intrinsic frequencies of the waves.
For Bragg resonance, even a uniform velocity field changes the resonance
condition. Velocity shear strongly influences the resonance conditions since,
in addition to changing the intrinsic frequencies, it can cause unequal Doppler
shifts between the surface, pycnocline, and the bottom. Using multiple scale
analysis and Fredholm alternative, we analytically obtain the equations
governing both the Bragg resonance and the wave triads. We have also extended
the Higher Order Spectral method, a highly efficient computational tool usually
used to study triad and Bragg resonance problems, to incorporate the effect of
piecewise linear velocity profile. A significant aspect, both in theoretical
and numerical fronts, has been extending the potential flow approximation,
which is the basis of studying these kinds of problems, to incorporate
piecewise constant background shear.",1808.06236v3
2018-12-10,A study of coherent and incoherent resonances in high intensity beams using a linear Paul trap,"In this paper we present a quantitative measurement of the change in
frequency (tune) with intensity of four transverse resonances in a high
intensity Gaussian beam. Due to the non-linear space charge forces present in
high intensity beams, particle motion cannot be analytically described. Instead
we use the Simulator of Particle Orbit Dynamics (S-POD) and the Intense Beam
Experiment (IBEX), two linear Paul traps, to experimentally replicate the
system. In high intensity beams a coherent resonant response to both space
charge and external field driven perturbations is possible, these coherent
resonances are excited at a tune that differs by a factor $C_{m}$ from that of
the incoherent resonance. By increasing the number of ions stored in the linear
Paul trap and studying the location of four different resonances we extract
provisional values describing the change in tune of the resonance with
intensity. These values are then compared to the $C_{m}$ factors for coherent
resonances. We find that the $C_{m}$ factors do not accurately predict the
location of resonances in high intensity Gaussian beams. Further insight into
the experiment is gained through simulation using Warp, a particle-in-cell
code.",1812.03761v2
2018-12-20,Strong Strain-Induced Coupling between Nanomechanical Pillar Resonators,"Networks of coupled resonators are an ubiquitous concept in physics, forming
the basis of synchronization phenomena, metamaterial formation, nonreciprocal
behavior and topological effects. Such systems are typically explored using
optical or microwave resonators. In recent years, mechanical resonators have
entered the stage as universal building block for resonator networks, both for
their well-controlled mechanical properties and for their eigenfrequencies
conveniently located in the radio-frequency regime. Vertically oriented
nanomechanical pillar resonators are ideally suited for the dense integration
into large resonator networks. However, to realize the potential of these
promising systems, an intrinsic coupling mechanism needs to be established.
Here, we demonstrate strain-induced, strong coupling between two adjacent
nanomechanical pillar resonators. The coupling is mediated through the strain
distribution in the joint substrate caused by the flexural vibration of the
pillars, such that the coupling strength can be controlled by the geometric
properties of the nanopillars as well as their separation. Both, mode
hybridization and the formation of an avoided level crossing in the response of
the nanopillar pair are experimentally observed. The coupling mechanism is
readily scalable to large arrays of nanopillars, enabling all-mechanical
resonator networks for the investigation of a broad range of collective
dynamical phenomena.",1812.08614v1
2019-03-20,Limits of flexural wave absorption by open lossy resonators: reflection and transmission problems,"The limits of flexural wave absorption by open lossy resonators are
analytically and numerically reported in this work for both the reflection and
transmission problems. An experimental validation for the reflection problem is
presented. The reflection and transmission of flexural waves in 1D resonant
thin beams are analyzed by means of the transfer matrix method. The hypotheses,
on which the analytical model relies, are validated by experimental results.
The open lossy resonator, consisting of a finite length beam thinner than the
main beam, presents both energy leakage due to the aperture of the resonators
to the main beam and inherent losses due to the viscoelastic damping. Wave
absorption is found to be limited by the balance between the energy leakage and
the inherent losses of the open lossy resonator. The perfect compensation of
these two elements is known as the critical coupling condition and can be
easily tuned by the geometry of the resonator. On the one hand, the scattering
in the reflection problem is represented by the reflection coefficient. A
single symmetry of the resonance is used to obtain the critical coupling
condition. Therefore the perfect absorption can be obtained in this case. On
the other hand, the transmission problem is represented by two eigenvalues of
the scattering matrix, representing the symmetric and anti-symmetric parts of
the full scattering problem. In the geometry analyzed in this work, only one
kind of symmetry can be critically coupled, and therefore, the maximal
absorption in the transmission problem is limited to 0.5. The results shown in
this work pave the way to the design of resonators for efficient flexural wave
absorption.",1903.08522v1
2019-04-16,Long-term Hydrodynamic Simulations on the Planetesimals Trapped in the First-order Mean Motion Resonances,"The resonant perturbations from planets are able to halt the drag-induced
migration, and capture the inwardly drifting planetesimals into mean motion
resonances. The equilibrium eccentricity of planetesimals in resonances, and
the minimum size of planetesimal that can trigger resonance trapping, have been
analyzed and formulated. However, the analytical works based on the assumption
that the disk is axisymmetric, which is violated by the asymmetric structures
developed by planets. We perform long-term 2D hydrodynamic simulations to study
the dynamics of planetesimals in the $j:(j+1)$ first-order exterior resonances,
and reexamine the theoretical expressions. We find the expression of
equilibrium eccentricity underestimates the values for resonances with $j < 5$,
in particular the 1:2 resonance that the underestimation can be $30 - 40\%$.
Within the parameter space we explored, we find the equilibrium eccentricity
and the minimum size are reduced in an asymmetric disk. The amount of
discrepancy in eccentricity depends on the degree of asymmetric structures. For
cases of Earth-sized planets, where the disk is less disturbed, the
planetesimal's eccentricity can reach to the values predicted by our modified
expression. For gaseous planets, however, the eccentricity can be $0.01 - 0.02$
smaller in value. We find the minimum size is 10 times smaller, and the factor
seems to be independent of the planet's mass. The influences of asymmetric
profiles on the eccentricity and the minimum size could affect the outcome of
collisions between resonant and nonresonant planetesimals, and the amount of
planetesimals migrated into the planet's feeding zone.",1904.07552v3
2019-11-14,Collective resonance in helical superstructures of gold nanorods,"Chiroptical responses of helical superstructures are determined by collective
behaviors of the individual building blocks. In this paper, we present a full
theoretical description of the collective resonance in superstructures. We use
the gold nanorods as individual building blocks and arrange them helically
along an axis in an end-to-end fashion. Numerical simulations on single-unit
cells reveal that the plasmonic coupling between the nanorods produces
hybridized resonances, whose intensity is strongly dependent on the excitation
light with left- or right-handed circular polarizations (LCP or RCP). A
node-mode criterion is proposed on the basis of the microscopic mechanism,
which successfully explains the difference between LCP and RCP. We further
demonstrate, by repeating the unit cell from 1 to infinity along the helical
axis, the multiple hybridized resonances gradually evolve and merge into a
single collective resonance, whose energy is also dependent on LCP and RCP. An
analytical description is provided for the collective resonance of the helical
superstructure on the basis of the coupled dipole approximation method. Our
theory shows that n collective resonance modes are present in the helical
superstructure with the unit cell consisting of $n$ nanorods. Strikingly, only
one resonance can be excited by the incident light with certain circular
polarization. We propose a universal selection rule for such selective
excitation of the collective resonances by analyzing the symmetry of the
helical superstructures. The new insights provided in this work may shed light
on future designs and fabrications of helical superstructures using plasmonic
building blocks.",1911.06098v2
2020-05-11,On-chip microwave filters for high-impedance resonators with gate-defined quantum dots,"Circuit quantum electrodynamics (QED) employs superconducting microwave
resonators as quantum buses. In circuit QED with semiconductor
quantum-dot-based qubits, increasing the resonator impedance is desirable as it
enhances the coupling to the typically small charge dipole moment of these
qubits. However, the gate electrodes necessary to form quantum dots in the
vicinity of a resonator inadvertently lead to a parasitic port through which
microwave photons can leak, thereby reducing the quality factor of the
resonator. This is particularly the case for high-impedance resonators, as the
ratio of their total capacitance over the parasitic port capacitance is
smaller, leading to larger microwave leakage than for 50-$\Omega$ resonators.
Here, we introduce an implementation of on-chip filters to suppress the
microwave leakage. The filters comprise a high-kinetic-inductance nanowire
inductor and a thin-film capacitor. The filter has a small footprint and can be
placed close to the resonator, confining microwaves to a small area of the
chip. The inductance and capacitance of the filter elements can be varied over
a wider range of values than their typical spiral inductor and interdigitated
capacitor counterparts. We demonstrate that the total linewidth of a 6.4 GHz
and approximately 3-k$\Omega$ resonator can be improved down to 540 kHz using
these filters.",2005.05411v2
2020-06-23,Exploiting periodic orbits as dynamical clues for Kepler and K2 systems,"Many extrasolar systems possessing planets in mean-motion resonance or
resonant chain have been discovered to date. The transit method coupled with
transit timing variation analysis provides an insight into the physical and
orbital parameters of the systems, but suffers from observational limitations.
When a (near-)resonant planetary system resides in the dynamical neighbourhood
of a stable periodic orbit, its long-term stability, and thus survival, can be
guaranteed. We use the intrinsic property of the periodic orbits, namely their
linear horizontal and vertical stability, to validate or further constrain the
orbital elements of detected two-planet systems. We computed the families of
periodic orbits in the general three-body problem for several two-planet Kepler
and K2 systems. The dynamical neighbourhood of the systems is unveiled with
maps of dynamical stability. Additional validations or constraints on the
orbital elements of K2-21, K2-24, Kepler-9, and (non-coplanar) Kepler-108
near-resonant systems were achieved. While a mean-motion resonance locking
protects the long-term evolution of the systems K2-21 and K2-24, such a
resonant evolution is not possible for the Kepler-9 system, whose stability is
maintained through an apsidal anti-alignment. For the Kepler-108 system, we
find that the stability of its mutually inclined planets could be justified
either solely by a mean-motion resonance, or in tandem with an inclination-type
resonance. Going forward, dynamical analyses based on periodic orbits could
yield better constrained orbital elements of near-resonant extrasolar systems
when performed in parallel to the fitting of the observational data.",2006.12895v1
2020-06-29,Imaging and Spectroscopy of Domains of the Cellular Membrane by Photothermal-Induced Resonance,"We use photothermal induced resonance (PTIR) imaging and spectroscopy, in
resonant and non-resonant mode, to study the cytoplasmic membrane and surface
of intact cells. Non-resonant PTIR images apparently provide rich details of
the cell surface. However we show that non-resonant image contrast does not
arise from the infrared absorption of surface molecules and is instead
dominated by the mechanics of tip-sample contact. In contrast, spectra and
images of the cellular surface can be selectively obtained by tuning the
pulsing structure of the laser to restrict thermal wave penetration to the
surface layer. Resonant PTIR images reveal surface structures and domains that
range in size from about 20 nm to 1 um and are associated to the cytoplasmic
membrane and its proximity. Resonant PTIR spectra of the cell surface are
comparable to far-field IR spectra and provide the first selective measurement
of the IR absorption spectrum of the cellular membrane of an intact cell. In
resonant PTIR images, signal intensity, and therefore contrast, can be ascribed
to a variety of factors, including mechanical, thermodynamic and spectroscopic
properties of the cellular surface. While PTIR images are difficult to
interpret in terms of spectroscopic absorption, they are easy to collect and
provide unique contrast mechanisms without any exogenous labeling. As such they
provide a new paradigm in cellular imaging and membrane biology and can be used
to address a range of critical questions, from the nature of membrane lipid
domains to viral membrane fusion.",2006.16306v1
2020-08-05,Observing off-resonance motion of nanomechanical resonators as modal superposition,"Observation of resonance modes is the most straightforward way of studying
mechanical oscillations because these modes have maximum response to stimuli.
However, a deeper understanding of mechanical motion could be obtained by also
looking at modal responses at frequencies in between resonances. A common way
to do this is to force a mechanical object into oscillations and study its
off-resonance behaviour. In this paper, we present visualisation of the modal
response shapes for a mechanical drum driven off resonance. By using the
frequency modal analysis, we describe these shapes as a superposition of
resonance modes. We find that the spatial distribution of the oscillating
component of the driving force affects the modal weight or participation.
Moreover, we are able to infer the asymmetry of the drum by studying the
dependence of the resonance modes shapes on the frequency of the driving force.
Our results highlight that dynamic responses of any mechanical system are
mixtures of their resonance modes with various modal weights, further giving
credence to the universality of this phenomenon.",2008.02040v1
2020-11-27,From single-particle-like to interaction-mediated plasmonic resonances in graphene nanoantennas,"Plasmonic nanostructures attract tremendous attention as they confine
electromagnetic fields well below the diffraction limit while simultaneously
sustaining extreme local field enhancements. To fully exploit these properties,
the identification and classification of resonances in such nanostructures is
crucial. Recently, a novel figure of merit for resonance classification has
been proposed 1 and its applicability was demonstrated mostly to toy model
systems. This novel measure, the energy-based plasmonicity index (EPI),
characterizes the nature of resonances in molecular nanostructures. The EPI
distinguishes between either a single-particle-like or a plasmonic nature of
resonances based on the energy space coherence dynamics of the excitation. To
advance the further development of this newly established measure, we present
here its exemplary application to characterize the resonances of graphene
nanoantennas. In particular, we focus on resonances in a doped nanoantenna. The
structure is of interest, as a consideration of the electron dynamics in real
space might suggest a plasmonic nature of selected resonances in the low doping
limit but our analysis reveals the opposite. We find that in the undoped and
moderately doped nanoantenna, the EPI classifies all emerging resonances as
predominantly single-particle-like and only after doping the structure heavily,
the EPI observes plasmonic response.",2011.13854v1
2021-02-10,Tidal Circularization of Binaries by Resonance Locking I: The Importance of the Pre-Main-Sequence,"Although tidal dissipation in binary stars has been studied for over a
century, theoretical predictions have yet to match the observed properties of
binary populations. This work quantitatively examines the recent proposal of
tidal circularization by resonance locking, where tidal dissipation arises from
resonances between the star's natural oscillation frequencies and harmonics of
the orbital frequency, and where resonances are `locked' for an extended period
of time due to concurrent stellar evolution. We focus on tidal resonances with
axi-symmetric gravity-modes, and examine binaries with primary masses from one
to two solar masses. We find that orbital evolution via resonance locking
occurs primarily during the star's pre-main-sequence phase, with the
main-sequence phase contributing negligibly. Resonance locking, ignoring
non-linearity, can circularize binaries with peri-centre distances out to $\sim
10$ stellar radii, corresponding to circular periods of $\sim 4-6$ days.
However, we find resonantly excited gravity-modes will become nonlinear in
stellar cores, which prevents them from reaching their full, linear amplitudes.
We estimate that such a `saturated resonance lock' reduces the circularization
period by about a third, but resonance locking remains much more effective than
the cumulative actions of equilibrium tides. In a companion paper, we examine
recent binary data to compare against theory.",2102.05668v1
2021-03-09,Classification of resonances and pairing effects on $NA$-scattering within the HFB framework,"We analyze the properties of the scattering solutions obtained as the pole of
the S- and K-matrix with the help of the Jost function framework and the
Strum-Liouville theory within the Hartree-Fock-Bogoliubov(HFB) framework, and
clarify the scattering solutions which can be defined as the physical state. We
found that there are three types of the resonances; ""{\it shape resonance}"",
""{\it particle-type}"" and ""{\it hole-type quasiparticle resonances}"", and
another two types of solutions are given as the independent S-matrix and
K-matrix poles. The shape resonance is formed by the Hartree-Fock(HF) mean
field potential, is not affected by the pairing correlation so much. The
particle-type and hole-type quasiparticle resonances originate from the
particle and hole states by the configuration mixing effect by pairing. All of
resonance are represented by the S-matrix pole which has the corresponding
K-matrix pole. Two other types of solutions are given by the independent
S-matrix and K-matrix poles. These poles are formed by the HF mean field
potential. The effect of pairing for the independent S-matrix pole is small,
but the one for the independent K-matrix pole has the remarkable effect. The
independent K-matrix pole destroys the quasiparticle resonance as it approaches
to the resonance by the pairing effect. The wave function of all resonances
have the characteristic structure of the metastable property. However, the
metastable structure of the wave function of the quasiparticle resonance can be
broken by the independent standing wave solution or the Fano effect.",2103.05181v1
2021-04-07,Importance of tidal resonances in extreme-mass-ratio inspirals,"Extreme mass ratio inspirals (EMRIs) will be important sources for future
space-based gravitational-wave detectors. In recent work, tidal resonances in
binary orbital evolution induced by the tidal field of nearby stars or black
holes have been identified as being potentially significant in the context of
extreme mass-ratio inspirals. These resonances occur when the three orbital
frequencies describing the orbit are commensurate. During the resonance, the
orbital parameters of the small body experience a jump leading to a shift in
the phase of the gravitational waveform. In this paper, we treat the tidal
perturber as stationary and restricted to the equatorial plane, and present a
first study of how common and important such resonances are over the entire
orbital parameter space. We find that a large proportion of inspirals encounter
a low-order resonance in the observationally important regime. While the
instantaneous effect of a tidal resonance is small, its effect on the
accumulated phase of the gravitational waveform of an EMRI system can be
significant due to its many cycles in band; we estimate that the effect is
detectable for a significant fraction of sources. We also provide fitting
formulae for the induced change in the constants of motion of the orbit due to
the tidal resonance for several low-order resonances.",2104.03422v2
2021-05-06,A universal deep learning strategy for designing high-quality-factor photonic resonances,"Resonance is instrumental in modern optics and photonics for novel phenomena
such as cavity quantum electrodynamics and electric-field-induced transparency.
While one can use numerical simulations to sweep geometric and material
parameters of optical structures, these simulations usually require
considerably long calculation time (spanning from several hours to several
weeks) and substantial computational resources. Such requirements significantly
limit their applicability in understanding and inverse designing structures
with desired resonance performances. Recently, the introduction of artificial
intelligence allows for faster predictions of resonance with less demanding
computational requirements. However, current end-to-end deep learning
approaches generally fail to predict resonances with high quality-factors
(Q-factor). Here, we introduce a universal deep learning strategy that can
predict ultra-high Q-factor resonances by decomposing spectra with an adaptive
data acquisition (ADA) method while incorporating resonance information. We
exploit bound states in the continuum (BICs) with an infinite Q-factor to
testify this resonance-informed deep learning (RIDL) strategy. The trained RIDL
strategy achieves high-accuracy prediction of reflection spectra and photonic
band structures while using a considerably small training dataset. We further
develop an inverse design algorithm based on the RIDL strategy for a
symmetry-protected BIC on a suspended silicon nitride photonic crystal (PhC)
slab. The predicted and measured angle-resolved band structures show minimum
differences. We expect the RIDL strategy to apply to many other physical
phenomena which exhibit Gaussian, Lorentzian, and Fano resonances.",2105.03001v1
2022-01-03,Resonance-enhanced spectral funneling in Fabry-Perot resonators with a temporal boundary mirror,"A temporal boundary refers to a specific time at which the properties of an
optical medium are abruptly changed. When light interacts with the temporal
boundary, its spectral content can be redistributed due to the breaking of
continuous time-translational symmetry of the medium where light resides. In
this work, we use this principle to demonstrate, at terahertz (THz)
frequencies, the resonance-enhanced spectral funneling of light coupled to a
Fabry-Perot resonator with a temporal boundary mirror. To produce a temporal
boundary effect, we abruptly increase the reflectance of a mirror constituting
the Fabry-Perot resonator and, correspondingly, its quality factor in a
step-like manner. The abrupt increase in the mirror reflectance leads to a
trimming of the coupled THz pulse that causes the pulse to broaden in the
spectral domain. Through this dynamic resonant process, the spectral contents
of the input THz pulse are redistributed into the modal frequencies of the
high-Q Fabry-Perot resonator formed after the temporal boundary. An energy
conversion efficiency of up to 33% was recorded for funneling into the
fundamental mode with a Fabry-Perot resonator exhibiting a sudden Q-factor
change from 4.8 to 48. We anticipate that the proposed resonance-enhanced
spectral funneling technique could be further utilized in the development of
efficient mechanically tunable narrowband terahertz sources for diverse
applications.",2201.00440v1
2022-01-29,A Wireless and Battery-free Biosensor Based on Parallel Resonators for Monitoring a Wide Range of Biosignals,"This paper proposes a novel wireless, battery-free, and label-free biosensor
for minimally invasive and non-invasive permittivity sensing for applications
such as detecting glucose levels in the interstitial dermal fluid. The
miniaturized, fully passive sensor is based on two symmetric parallel 0.8
mm$^3$ LC (inductor-capacitor) resonators. Each inductor is integrated with a
conductive plate at one of its terminals. The passive sensor's main field is
dominant outside the resonators, creating an effective capacitance outside the
sensor, unlike reported in previous studies where the effective capacitance was
limited to between the resonator lines. The proposed sensor was further
analyzed under two different scenarios to change the region of effective
capacitance and test its suitability for pressure monitoring, such as wound
monitoring; first, by repositioning one of the two resonators, and second, by
replacing one of the resonators with a conductive plate. The experimental
results confirmed the proposed passive sensor's performance in detecting the
glucose concentration in an aqueous solution with a sensitivity of 500 and 46
kHz/(mg/dL) for minimal invasive and non-invasive monitoring, respectively,
within the glucose range of 0-500 mg/dL with volume sample requirements as low
as 60 $\mu$L. Further, by repositioning one of the resonators, the effective
capacitance lies inside the passive sensor, making it suitable for wound
monitoring. The results indicated that the resonance shift can be made fairly
linear with respect to the variation in the separation between the resonators
with a sensitivity of 2.5$\times 10^3$ MHz/mm within the separation range of
0.2-0.5 mm, considering separation as the main factor to sense the pressure or
healing of the wound.",2201.12566v1
2022-04-12,Multiplexable frequency retuning of MKID arrays using their non-linear kinetic inductance,"Microwave Kinetic Inductance Detector (MKID) arrays are currently being
developed and deployed for astronomical applications in the visible and near
infrared and for sub-millimetre astronomy. One of the main drawbacks of MKIDs
is that large arrays would exhibit a pixel yield, the percentage of
individually distinguishable pixels to the total number of pixels, of 75 - 80
%. Imperfections arising during the fabrication can induce an uncontrolled
shift in the resonance frequency of individual resonators which can end up
resonating at the same frequency of a different resonator. This makes a number
of resonators indistinguishable and therefore unusable for imaging. This paper
proposes an approach to individually re-tune the colliding resonators in order
to remove the degeneracy and increase the number of MKIDs with unique resonant
frequencies. The frequency re-tuning is achieved through a DC bias of the
resonator, the kinetic inductance of a superconducting thin film is current
dependent and its dependence is non linear. Even though this approach has been
already proposed, an innovative pixel design, described in this paper, may
solve two issues previously described in literature such as increased
electromagnetic losses to the DC-bias line, and the multiplexibility of
multiple resonators on a single feedline.",2204.05715v1
2022-07-12,Long-term tidal evolution of the TRAPPIST-1 system,"The ultracool M-dwarf star TRAPPIST-1 is surrounded by seven planets
configured in a resonant chain. Transit-timing variations have shown that the
planets are caught in multiple three-body resonances and that their orbits are
slightly eccentric, probably caused by resonant forcing. The current values of
the eccentricities could be a remnant from their formation. Here we run
numerical simulations using fictitious forces of trapping the fully-grown
planets in resonances as they migrated in the gas disc, followed by numerical
simulations detailing their tidal evolution. For a reduced disc scale height
$h\sim 0.03$--0.05, the eccentricities of the planets upon capture in resonance
are higher than their current values by factors of a few. We show that the
current eccentricities and spacing of planets d to h are natural outcomes of
coupled tidal evolution wherein the planets simultaneously damp their
eccentricities and separate due to their resonant interaction. We further show
that the planets evolve along a set of equilibrium curves in semimajor
axis--eccentricity phase space that are defined by the resonances, and that
conserve angular momentum. As such, the current 8:5--5:3--(3:2)$^2$--4:3--3:2
resonant configuration cannot be reproduced from a primordial
(3:2)$^4$--4:3--3:2 resonant configuration from tidal dissipation in the
planets alone. We use our simulations to constrain the long-term tidal
parameters $k_2/Q$ for planets b to e, which are in the range $10^{-3}$ to
$10^{-2}$, and show that these are mostly consistent with those obtained from
interior modelling following reasonable assumptions.",2207.05336v1
2022-07-26,Extended planetary chaotic zones,"We consider the chaotic motion of low-mass bodies in two-body high-order
mean-motion resonances with planets in model planetary systems, and
analytically estimate the Lyapunov and diffusion timescales of the motion in
multiplets of interacting subresonances corresponding to the mean-motion
resonances. We show that the densely distributed (though not overlapping)
high-order mean-motion resonances, when certain conditions on the planetary
system parameters are satisfied, may produce extended planetary chaotic zones
-- ""zones of weak chaotization,"" -- much broader than the well-known planetary
connected chaotic zone, the Wisdom gap. This extended planetary chaotic zone
covers the orbital range between the 2/1 and 1/1 resonances with the planet. On
the other hand, the orbital space inner (closer to the host star) with respect
to the 2/1 resonance location is essentially long-term stable. This difference
arises because the adiabaticity parameter of subresonance multiplets
specifically depends on the particle's orbit size. The revealed effect may
control the structure of planetesimal disks in planetary systems: the orbital
zone between the 2/1 and 1/1 resonances with a planet should be normally free
from low-mass material (only that occasionally captured in the first-order 3/2
or 4/3 resonances may survive); whereas any low-mass population inner to the
2/1 resonance location should be normally long-lived (if not perturbed by
secular resonances, which we do not consider in this study).",2207.12747v1
2022-08-01,Searching for Ultra-Light Axions with Twisted Cavity Resonators of Anyon Rotational Symmetry with Bulk Modes of Non-Zero Helicity,"M\""obius-ring resonators stem from a well-studied and fascinating geometrical
structure that features a one-sided topology; the M\""obius strip, and have been
shown to exhibit fermion rotational symmetry with respect to a ring resonator
with no twist (which exhibits boson rotational symmetry) (see
PhysRevLett.101.247701). Here, we present a new type of resonator through the
formation of twisted hollow structures using equilateral triangular
cross-sections, which leads to the realization of a cavity with anyon
rotational symmetry. Unlike all previous cavity resonators, the anyon resonator
permits the existence of bulk resonant modes that exhibit non-zero
electromagnetic helicity in vacuo, with a non-zero overlap of the electric and
magnetic mode eigenvectors, $\int \mathbf{E}_p\cdot\mathbf{B}_p~d\tau$,
integrated over the cavity volume. In the upconversion limit, we show that
these non-zero helical modes couple naturally to ultra-light dark matter axions
within the bandwidth of the resonator by adding amplitude-modulated sidebands
through the axion-photon chiral anomaly. Thus, we show a sensitive ultra-light
dark matter experiment may be realized by implementing such a resonator in an
ultra-stable oscillator configuration and searching for signals in the Fourier
spectrum of amplitude fluctuations. This removes the typical requirement for an
external magnetic field and therefore permits the use of superconducting
materials to reduce surface losses and enhance sensitivity to axions.",2208.01640v3
2022-08-10,A Feshbach resonance in collisions between ultracold ground state molecules,"Collisional resonances are an important tool which has been used to modify
interactions in ultracold gases, for realizing novel Hamiltonians in quantum
simulations, for creating molecules from atomic gases and for controlling
chemical reactions. So far, such resonances have been observed for atom-atom
collisions, atom-molecule collisions and collisions between Feshbach molecules
which are very weakly bound. Whether such resonances exist for ultracold ground
state molecules has been debated due to the possibly high density of states
and/or rapid decay of the resonant complex. Here we report a very pronounced
and narrow (25 mG) Feshbach resonance in collisions between two ground state
NaLi molecules. This molecular Feshbach resonance has two special
characteristics. First, the collisional loss rate is enhanced by more than two
orders of magnitude above the background loss rate which is saturated at the
$p$-wave universal value, due to strong chemical reactivity. Second, the
resonance is located at a magnetic field where two open channels become nearly
degenerate. This implies the intermediate complex predominantly decays to the
second open channel. We describe the resonant loss feature using a model with
coupled modes which is analogous to a Fabry-P\'erot cavity. Our observations
prove the existence of long-lived coherent intermediate complexes even in
systems without reaction barriers and open up the possibility of coherent
control of chemical reactions.",2208.05557v1
2022-08-16,"Direct measurement of the low energy resonances in $^{22}\rm{Ne}(α,γ)^{26}\rm{Mg}$ reaction","The $^{22}\rm{Ne}(\alpha,\gamma)^{26}\rm{Mg}$ is an important reaction in
stellar helium burning environments as it competes directly with one of the
main neutron sources for the s-process, the
$^{22}\rm{Ne}(\alpha,n)^{25}\rm{Mg}$ reaction. The reaction rate of the
$^{22}\rm{Ne}(\alpha,\gamma)^{26}\rm{Mg}$ is dominated by the low energy
resonances at $E_{\alpha}^{lab}$ = 650 and 830 keV respectively. The
$E_{\alpha}^{lab}$ = 830 keV resonance has been measured previously, but there
are some uncertainties in the previous measurements. We confirmed the
measurement of the $E_{\alpha}^{lab}$ = 830 keV resonance using implanted
$^{22}$Ne targets. We obtained a resonance strength of $\omega\gamma$ = 35
$\pm$ 4 $\mu eV$, and provide a weighted average of the present and previous
measurements of $\omega\gamma$ = 35 $\pm$ 2 $\mu eV$ with reduced uncertainties
compared to previous studies. We also attempted to measure the strength of the
predicted resonance at $E_{\alpha}^{lab}$ = 650 keV directly for the first time
and found an upper limit of $\omega\gamma$ $\mathrm{<0.15}$ $\mu eV$ for the
strength of this resonance. In addition, we also studied the $E_{P}^{lab}$= 851
keV resonance in $^{22}\rm{Ne}(p,\gamma)^{23}\rm{Na}$, and obtained a resonance
strength of $\omega\gamma$ = 9.2 $\pm$ 0.7 eV with significantly lower
uncertainties compared to previous measurements.",2208.07885v1
2022-08-29,Multi Spectral Switchable Infra-Red Reflectance Resonances in Highly Subwavelength Partially Oxidized Vanadium Thin Films,"Phase transition materials are promising for realization of switchable
optics. In this work, we show reflectance resonances in the near-infrared and
long-wave infrared wavelengths in highly subwavelength partially oxidized
Vanadium thin films. These partially oxidized films consist of a multilayer of
Vanadium dioxide and Vanadium as shown using Raman spectroscopy and four-probe
measurements. As Vanadium dioxide is a phase transition material that shows
insulator to metal phase transition at 68 C, the observed infra-red resonances
can be switched with temperature into a high-reflectance state. The wavelength
of these resonances are passively tunable as a function of the oxidation
duration. The obtained reflectance resonance at near-infrared wavelength red
shifts from 1.78 um to 2.68 um with increasing oxidation duration while the
long-wavelength infrared resonance blue shifts from 12.68 um to 9.96 um. To
find the origin of the reflectance resonances, we model the reflectance spectra
as a function of the oxidation duration using the transfer matrix method. The
presented model captures the dual reflectance resonances reasonably well. These
passive wavelength-tunable and switchable resonances with easy to fabricate
lithography-free multilayer structure will be useful for multispectral
applications such as camouflage, spectral selective microbolometer, and thermal
management.",2208.13458v1
2022-09-01,The current orbit of Atlas (SXV),"With the success of the Cassini-Huygens mission, the dynamic complexity
surrounding natural satellites of Saturn began to be elucidated. New ephemeris
could be calculated with a higher level of precision, which made it possible to
study in detail the resonant phenomena and, in particular, the 54:53 near
mean-motion resonance between Prometheus and Atlas. For this task, we have
mapped in details the domains of the resonance with dense sets of initial
conditions and distinct ranges of parameters. Our initial goal was to identify
possible regions in the phase space of Atlas for which some critical angles,
associated with the 54:53 mean motion have a stable libration. Our
investigations revealed that there is no possibility for the current Atlas
orbital configuration to have any regular behavior since it is in a chaotic
region located at the boundary of the 54:53 mean-motion resonance phase space.
This result is in accordance with previous works (Cooper et al. 2015, Renner et
al. 2016). In this work, we generalize such investigations by showing detailed
aspects of the Atlas-Prometheus 54:53 mean-motion resonance, like the extension
of the chaotic layers, the thin domain of the center of the 54:53 resonance,
the proximity of other neighborhood resonances, among other secondary
conclusions. In particular, we have also shown that even in the deep interior
of the resonance, it is difficult to map periodic motion of the resonant pair
for very long time spans.",2209.01213v2
2022-09-22,Search for resonant and non-resonant Higgs boson pair production in the $b\bar bτ^+τ^-$ decay channel using 13 TeV $pp$ collision data from the ATLAS detector,"A search for Higgs boson pair production in events with two $b$-jets and two
$\tau$-leptons is presented, using a proton-proton collision dataset with an
integrated luminosity of 139 fb$^{-1}$ collected at $\sqrt{s}=13$ TeV by the
ATLAS experiment at the LHC. Higgs boson pairs produced non-resonantly or in
the decay of a narrow scalar resonance in the mass range from 251 to 1600 GeV
are targeted. Events in which at least one $\tau$-lepton decays hadronically
are considered, and multivariate discriminants are used to reject the
backgrounds. No significant excess of events above the expected background is
observed in the non-resonant search. The largest excess in the resonant search
is observed at a resonance mass of 1 TeV, with a local (global) significance of
$3.1\sigma$ ($2.0\sigma$). Observed (expected) 95% confidence-level upper
limits are set on the non-resonant Higgs boson pair-production cross-section at
4.7 (3.9) times the Standard Model prediction, assuming Standard Model
kinematics, and on the resonant Higgs boson pair-production cross-section at
between 21 and 900 fb (12 and 840 fb), depending on the mass of the narrow
scalar resonance.",2209.10910v2
2022-11-08,High-resolution resonant portraits of a single-planet white dwarf system,"The dynamical excitation of asteroids due to mean motion resonant
interactions with planets is enhanced when their parent star leaves the main
sequence. However, numerical investigation of resonant outcomes within
post-main-sequence simulations is computationally expensive, limiting the
extent to which detailed resonant analyses have been performed. Here, we
combine the use of a high-performance computer cluster and the general
semianalytical libration width formulation of Gallardo et al. (2021) in order
to quantify resonant stability, strength and variation instigated by stellar
evolution for a single-planet system containing asteroids on both crossing and
non-crossing orbits. We find that resonant instability can be accurately bound
with only main-sequence values by computing a maximum libration width as a
function of asteroid longitude of pericentre. We also quantify the relative
efficiency of mean motion resonances of different orders to stabilize versus
destabilize asteroid orbits during both the giant branch and white dwarf
phases. The 4:1, 3:1 and 2:1 resonances represent efficient polluters of white
dwarfs, and even when in the orbit-crossing regime, both the 4:3 and 3:2
resonances can retain small reservoirs of asteroids in stable orbits throughout
giant branch and white dwarf evolution. This investigation represents a
preliminary step in characterising how simplified extrasolar Kirkwood gap
structures evolve beyond the main-sequence.",2211.04487v1
2022-12-12,Analytical and Numerical Estimates for Solar Radiation Pressure Semi-secular Resonances,"The aim of this work is to provide new insights on the dynamics associated to
the resonances which arise as a consequence of the coupling of the effect due
to the oblateness of the Earth and the Solar Radiation Pressure (SRP) effect
for an uncontrolled object with moderate to high area-to-mass ratio. Analytical
estimates for the location of the resulting resonant equilibrium points are
provided, together with formulas to compute the maximum amplitude of the
corresponding variation in the eccentricity, as a function of the initial
conditions of the object and of its area-to-mass ratio. The period of the
variations of the eccentricity and inclinations due to such resonances is
estimated using classical formulas. A classification based on the strength of
the SRP resonances is provided. The estimates presented in the paper are
validated using numerical tools, including the use of Fast Lyapunov Indicators
to draw phase portraits and bifurcation diagrams. Many FLI maps depicting the
location and overlapping of SRP resonances are presented. The results from this
paper suggest that SRP resonances could be modeled in the context of either the
Extended Fundamental Model by [1] or the Second Fundamental Model by [2].
  [1] S. Breiter. Extended fundamental model of resonance. Celestial Mechanics
and Dynamical Astronomy, 85:209-218, 03 (2003). doi: 10.1023/A:1022569419866
  [2] J. Henrard and A. Lemaitre. A second fundamental model for resonance.
Celestial Mechanics, 30:197-218, (1983). doi: 10.1007/BF01234306",2212.06282v1
2023-01-16,Circle fit optimization for resonator quality factor measurements: point redistribution for maximal accuracy,"The control of material loss mechanisms is playing an increasingly important
role for improving coherence times of superconducting quantum devices. Such
material losses can be characterized through the measurement of planar
superconducting resonators, which reflect losses through the resonance's
quality factor $Q_l$. The resonance quality factor consists of both internal
(material) losses as well as coupling losses when resonance photons escape back
into the measurement circuit. The combined losses are then described as
$Q_l^{-1} = \mathrm{Re}\{Q_c^{-1}\} + Q_i^{-1}$, where $Q_c$ and $Q_i$ reflect
the coupling and internal quality factors of the resonator, respectively. To
separate the relative contributions of $Q_i$ and $Q_c$ to $Q_l$,
diameter-correcting circle fits use algebraic or geometric means to fit the
resonance signal on the complex plane. However, such circle fits can produce
varied results, so to address this issue, we use a combination of simulation
and experiment to determine the reliability of a fitting algorithm across a
wide range of quality factor values from $Q_i\ll Q_c$ to $Q_c\ll Q_i$. In
addition, we develop a novel measurement protocol that can not only reduce
fitting errors by factors $\gtrsim 2$ but also mitigates the influence of the
measurement background on the fit results. This technique can be generalized
for other resonance systems beyond superconducting resonators.",2301.06364v2
2023-02-06,Enhancement of broadband entangled two-photon absorption by resonant spectral phase flips,"Broadband energy-time entanglement can be used to enhance the rate of
two-photon absorption (TPA) by combining a precise two-photon resonance with a
very short coincidence time. Because of this short coincidence time, broadband
TPA is not sensitive to the spectrum of intermediate levels, making it the
optimal choice when the intermediate transitions are entirely virtual. In the
case of distinct intermediate resonances, it is possible to enhance TPA by
introducing a phase dispersion that matches the intermediate resonances. Here,
we consider the effects of a phase flip in the single photon spectrum, where
the phases of all frequencies above a certain frequency are shifted by half a
wavelength relative to the frequencies below this frequency. The frequency at
which the phase is flipped can then be scanned to reveal the position of
intermediate resonances. We find that a resonant phase flip maximizes the
contributions of the asymmetric imaginary part of the dispersion that
characterizes a typical resonance, resulting in a considerable enhancement of
the TPA rate. Due to the bosonic symmetry of TPA, the enhancement is strongest
when the resonance occurs when the frequency difference of the two photons is
much higher than the linewidth of the resonance. Our results indicate that
broadband entangled TPA with spectral phase flips may be suitable for
phase-sensitive spectroscopy at the lower end of the spectrum where direct
photon detection is difficult.",2302.02846v3
2023-02-13,Performance of high impedance resonators in dirty dielectric environments,"High-impedance resonators are a promising contender for realizing
long-distance entangling gates between spin qubits. Often, the fabrication of
spin qubits relies on the use of gate dielectrics which are detrimental to the
quality of the resonator. Here, we investigate loss mechanisms of
high-impedance NbTiN resonators in the vicinity of thermally grown
SiO\textsubscript{2} and Al\textsubscript{2}O\textsubscript{3} fabricated by
atomic layer deposition. We benchmark the resonator performance in elevated
magnetic fields and at elevated temperatures and find that the internal quality
factors are limited by the coupling between the resonator and two-level systems
of the employed oxides. Nonetheless, the internal quality factors of
high-impedance resonators exceed $10^3$ in all investigated oxide
configurations which implies that the dielectric configuration would not limit
the performance of resonators integrated in a spin-qubit device. Because these
oxides are commonly used for spin qubit device fabrication, our results allow
for straightforward integration of high-impedance resonators into spin-based
quantum processors. Hence, these experiments pave the way for large-scale,
spin-based quantum computers.",2302.06303v2
2023-03-14,Polarized proton structure in the resonance region,"In view of the precise data available on inclusive polarized electron
scattering off polarized proton targets in the nucleon resonance excitation
region, we compare these results with the coherent sum of resonant
contributions to the polarized structure function $g_1$ and virtual photon
asymmetry $A_1$. To this goal, we employ the nucleon resonance
electroexcitation amplitudes determined for photon virtualities $Q^2$ $<$ 5.0
GeV$^2$ from analyses of the CLAS data on exclusive electroproduction off
protons in the resonance region. Most of the well established resonances of
four star PDG status in the mass range up to 1.75~GeV are included. We find
that the resonance-like structures observed in the inclusive $g_1$ data are
related to the resonant contributions in the entire range of photon virtuality
$Q^2$ where the data on $g_1$ are available. In the range of invariant mass of
the final hadron system $W$ $>$ 1.5 GeV, the data on the asymmetry $A_1$ are
well reproduced even when accounting for resonant contributions only,
especially for the larger values of $Q^2$ and energies analysed. This
observation offers an interesting hint to quark-hadron duality seen in
polarized inclusive electron scattering observables.",2303.07720v1
2023-04-25,Compact inductor-capacitor resonators at sub-gigahertz frequencies,"Compact inductor-capacitor (LC) resonators, in contrast to coplanar waveguide
(CPW) resonators, have a simple lumped-element circuit representation but
usually call for sophisticated finite-element method (FEM) simulations for an
accurate modelling. Here we present an simple analytical model for a family of
coplanar LC resonators where the electrical properties are directly obtained
from the circuit geometry with a satisfying accuracy. Our experimental results
on $10$ high-internal-quality-factor resonators ($Q_{\rm i}\gtrsim 2\times
10^{5}$), with frequency ranging roughly from $300\,{\rm MHz}$ to $1\,{\rm
GHz}$, show an excellent consistency with both the derived analytical model and
detailed FEM simulations. These results showcase the ability to design
sub-gigahertz resonators with less than $2\%$ deviation in the resonance
frequency, which has immediate applications, for example, in the implementation
of ultrasensitive cryogenic detectors. The achieved compact resonator size of
the order of a square millimeter indicates a feasible way to integrate hundreds
of microwave resonators on a single chip for realizing photonic lattices.",2304.12744v1
2023-05-09,Direct Measurement of A Spatially Varying Thermal Bath Using Brownian Motion,"Micro-mechanical resonator performance is fundamentally limited by the
coupling to a thermal environment. The magnitude of this thermodynamical effect
is typically considered in accordance with a physical temperature, assumed to
be uniform across the resonator's physical span. However, in some
circumstances, e.g. quantum optomechanics or interferometric gravitational wave
detection, the temperature of the resonator may not be uniform, resulting in
the resonator being thermally linked to a spatially varying thermal bath. In
this case, the link of a mode of interest to its thermal environment is less
straightforward to understand. Here, we engineer a distributed bath on a
germane optomechanical platform -- a phononic crystal -- and utilize both
highly localized and extended resonator modes to probe the spatially varying
bath in entirely different bath regimes. As a result, we observe striking
differences in the modes' Brownian motion magnitude. From these measurements we
are able to reconstruct the local temperature map across our resonator and
measure nanoscale effects on thermal conductivity and radiative cooling. Our
work explains some thermal phenomena encountered in optomechanical experiments,
e.g. mode-dependent heating due to light absorption. Moreover, our work
generalizes the typical figure of merit quantifying the coupling of a resonator
mode to its thermal environment from the mechanical dissipation to the overlap
between the local dissipation and the local temperature throughout the
resonator. This added understanding identifies design principles that can be
applied to performance of micro-mechanical resonators.",2305.05616v1
2023-11-21,Geometry dependence of TLS noise and loss in a-SiC:H parallel plate capacitors for superconducting microwave resonators,"Parallel plate capacitors (PPC) significantly reduce the size of
superconducting microwave resonators, reducing the pixel pitch for arrays of
single photon energy-resolving kinetic inductance detectors (KIDs). The
frequency noise of KIDs is typically limited by tunneling Two-Level Systems
(TLS), which originate from lattice defects in the dielectric materials
required for PPCs. How the frequency noise level depends on the PPC's
dimensions has not been experimentally addressed. We measure the frequency
noise of 56 resonators with a-SiC:H PPCs, which cover a factor 44 in PPC area
and a factor 4 in dielectric thickness. To support the noise analysis, we
measure the TLS-induced, power-dependent, intrinsic loss and
temperature-dependent resonance frequency shift of the resonators. From the TLS
models, we expect a geometry-independent microwave loss and resonance frequency
shift, set by the TLS properties of the dielectric. However, we observe a
thickness-dependent microwave loss and resonance frequency shift, explained by
surface layers that limit the performance of PPC-based resonators. For a
uniform dielectric, the frequency noise level should scale directly inversely
with the PPC area and thickness. We observe that an increase in PPC size
reduces the frequency noise, but the exact scaling is, in some cases, weaker
than expected. Finally, we derive an engineering guideline for the design of
KIDs based on PPC-based resonators.",2311.12681v1
2023-12-14,Towards Inductive Robustness: Distilling and Fostering Wave-induced Resonance in Transductive GCNs Against Graph Adversarial Attacks,"Graph neural networks (GNNs) have recently been shown to be vulnerable to
adversarial attacks, where slight perturbations in the graph structure can lead
to erroneous predictions. However, current robust models for defending against
such attacks inherit the transductive limitations of graph convolutional
networks (GCNs). As a result, they are constrained by fixed structures and do
not naturally generalize to unseen nodes. Here, we discover that transductive
GCNs inherently possess a distillable robustness, achieved through a
wave-induced resonance process. Based on this, we foster this resonance to
facilitate inductive and robust learning. Specifically, we first prove that the
signal formed by GCN-driven message passing (MP) is equivalent to the
edge-based Laplacian wave, where, within a wave system, resonance can naturally
emerge between the signal and its transmitting medium. This resonance provides
inherent resistance to malicious perturbations inflicted on the signal system.
We then prove that merely three MP iterations within GCNs can induce signal
resonance between nodes and edges, manifesting as a coupling between nodes and
their distillable surrounding local subgraph. Consequently, we present Graph
Resonance-fostering Network (GRN) to foster this resonance via learning node
representations from their distilled resonating subgraphs. By capturing the
edge-transmitted signals within this subgraph and integrating them with the
node signal, GRN embeds these combined signals into the central node's
representation. This node-wise embedding approach allows for generalization to
unseen nodes. We validate our theoretical findings with experiments, and
demonstrate that GRN generalizes robustness to unseen nodes, whilst maintaining
state-of-the-art classification accuracy on perturbed graphs.",2312.08651v1
2023-12-20,Flux coupled tunable superconducting resonator,"We present a design and implementation of frequency-tunable superconducting
resonator. The resonance frequency tunability is achieved by flux-coupling a
superconducting LC-loop to a current-biased feedline; the resulting screening
current leads to a change of the kinetic inductance and shift in the resonance
frequency. The thin film aluminum resonator consists of an interdigitated
capacitor and thin line inductors forming a closed superconducting loop. The
magnetic flux from the nearby current feedline induces Meissner shielding
currents in the resonator loop leading to change in the kinetic part of the
total inductance of the resonator. We demonstarte continuous frequency tuning
within 160 MHz around the resonant frequency of 2.7 GHz. We show that: (1)
frequency upconversion is achieved when kHz AC modulation signal is
superimposed onto the DC bias resulting in sidebands to the resonator tone; (2)
three-wave mixing is attained by parametrically pumping the nonlinear kinetic
inductance using a strong RF pump signal in the feedline. The simple
architecture is amenable to large array multiplexing and on-chip integration
with other circuit components. The concept could be applied in flux
magnetometers, upconverters, and parametric amplifiers operating above 4 Kelvin
cryogenic temperatures when alternative high critical temperature material with
high kinetic inductance is used.",2312.12755v1
2023-12-22,Interference of resonances in two-proton emission of $^{16}$Ne,"The $^{16}$Ne nucleus is a two-proton ($2p$) emitter, where an interference
of two resonances is expected since its core-proton subsystem,
$^{15}$F$=^{14}$O$+p$, has separate resonances in the $s_{1/2}$ and $d_{5/2}$
channels. We theoretically investigate the $2p$ emission from the unbound
$0^{+}$ state of $^{16}$Ne. To investigate the $2p$-emitting process, we
perform the time-dependent calculations based on the three-body model of
$^{14}$O$+p+p$. By evaluating the survival probability, a deviation from the
exponential decay is obtained. In correspondence, the $2p$-energy spectrum of
$^{16}$Ne is not of the single resonance, but an interference of the main
narrow and the second broad resonances is obtained. In time-dependent
calculations, the sequential $1p$-$1p$ emission from $^{16}$Ne is relatively
dominant as long as the manifest $s_{1/2}$ resonance in $^{15}$F exists. The
diproton-correlating emission becomes active only if the $s_{1/2}$ resonance is
broad. As conclusion, the $2p$ emission of $^{16}$Ne is one example of the
multi-resonance interference in open-quantum systems. The $s_{1/2}$
intermediate resonance is essential to realize this interference, and induces
the sequential emission. The $2p$-decaying state is predicted to have the
spin-singlet entanglement independently of whether the emission is sequential
or correlating.",2312.15017v2
1998-12-07,Resonant Tidal Excitations of Rotating Neutron Stars in Coalescing Binaries,"In a coalescing neutron star-neutron star (NS-NS) or neutron star-black hole
(NS-BH) binary, oscillation modes of the NS can be resonantly excited by the
companion during the final minutes of the inspiral. The resonant energy
transfer between the orbit and NS speeds up or slows down the inspiral and
induces a phase change in the emitted gravitational waves from the binary. A
tidal resonance, (jk,m), occurs when the mode frequency equals m times the
orbital frequency. For f-mode resonance to occur before coalescence, the NS
must have rapid rotation, with spin frequency nu_s>710Hz for (22,2)-resonance
and nu_s>570Hz for (33,3)-resonance (M=1.4Mo and R=10km; however, for R=15km,
these spin frequencies become 330Hz and 250Hz). Because of strong tidal
coupling, f-mode resonances induce a large change in the number of orbital
cycles, N_orb, with maximum N_orb~10-1000 for (22,2)-resonance and N_orb~1 for
(33,3)- resonance. Such resonant effects, if present, must be included in
constructing waveform templates used in searching for gravitational wave
signals. Higher order f-mode resonances can occur at slower rotation rates, but
N_orb<0.1. For the dominant g-mode (22,2)-resonance, even modest rotation
(nu_s<100Hz) can enhance the resonant effect on the orbit by shifting resonance
to a smaller orbital frequency. However, because of the weak coupling, N_orb
lies in the range 10^-3-10^-2 (depending on the NS EOS) and is probably
negligible for the purpose of detecting gravitational waves. R-mode resonances
require misaligned spin-orbit inclinations, and the dominant resonances
correspond to (22,3) and (22,1). Since tidal coupling depends strongly on
rotation rate, N_orb<10^-2(R/10km)^(10)(M/1.4Mo)^(-20/3) is negligible for
canonical NS parameters but can be appreciable if the NS radius is larger.",9812116v2
2000-10-19,Resonant Gaps in the Scattered Cometary Population of the Trans-Neptunian Region,"Our numerical simulations of the Edgeworth-Kuiper belt objects
gravitationally scattered by the four giant planets accounting for mean motion
resonances reveal numerous resonant gaps in the distribution of the scattered
population.",0010402v1
2005-10-14,Resonance conditions,"Non-linear parametric resonances occur frequently in nature. Here we
summarize how they can be studied by means of perturbative methods. We show in
particular how resonances can affect the motion of a test particle orbiting in
the vicinity of a compact object. These mathematical toy-models find
application in explaining the structure of the observed kHz Quasi-Periodic
Oscillations: we discuss which aspects of the reality naturally enter in the
theory, and which one still remain a puzzle.",0510419v1
2007-01-29,On the Dynamics of Resonant Kuiper Belt Objects,"We propose a new mechanism of drag-induced resonant capture, which can
explain the resonant Kuiper Belt Objects in a natural way. A review and
comparison with the traditional mechanism of sweeping capture by the migrating
Neptune will be given.",0701807v1
1995-05-26,Stochastic resonance in a system of ferromagnetic particles,"We show that a dispersion of monodomain ferromagnetic particles in a solid
phase exhibits stochastic resonance when a driven linearly polarized magnetic
field is applied. By using an adiabatic approach, we calculate the power
spectrum, the distribution of residence times and the mean first passage time.
The behavior of these quantities is similar to their corresponding ones in
other systems in which stochastic resonance has also been observed.",9505136v1
1995-06-08,Time-dependent resonant tunneling via two discrete states,"We theoretically investigate time-dependent resonant tunneling via two
discrete states in an experimentally relevant setup. Our results show that the
dc transport through the system can be controled by applying irradiation with a
frequency which matches the energy difference between the discrete states. We
predict resonant phenomena which should be easily observable in experiments.",9506036v1
1997-12-11,Parametric resonance in atomic force microscopy: A new method to study the tip-surface interaction,"We propose a new method to investigate interactions involved in atomic force
microscopy (AFM). It is a dynamical method relying on the growth of
oscillations via parametric resonance. With this method the second and third
derivatives of the tip-surface interaction potential can be measured
simultaneously. Because of its threshold behavior parametric resonance AFM
leads to sharp contrasts in surface imaging.",9712120v1
1998-10-27,Novel Transport Mechanism for Interacting Electrons in Disordered Systems: Variable-Range Resonant Tunneling,"To interpret recent experimental observations of the phononless hopping
conduction, we suggest a novel transport mechanism according to which the
current-carrying single electrons move via quantum resonant tunneling between
localized states brought into resonance by fast electron hops in their
environment.",9810363v1
1999-02-16,Stochastic Resonance in Washboard Potentials,"We study the mobility of an overdamped particle in a periodic potential
tilted by a constant force. The mobility exhibits a stochastic resonance in
inhomogeneous systems with space dependent friction coefficient. The result
indicates that the presence of oscillating external field is not essential for
the observability of stochastic resonance, at least in the inhomogenous medium.",9902216v1
1999-04-20,The dimer-RVB State of the Four-Leg Heisenberg Ladder: Interference among Resonances,"We study the ground state of the 4-leg spin ladder using a dimer-RVB ansatz
and the Lanczos method. Besides the well known resonance mechanism between
valence bond configurations we find novel interference effects among nearby
resonances.",9904286v1
2000-05-01,Parametric Quantum Resonances for Bose-Einstein Condensates,"We generalize recent work on parametric resonances for nonlinear
Schr{\""o}dinger (NLS) type equations to the case of three dimensional
Bose-Einstein condensates at zero temperatures. We show the possibility of such
resonances in the three-dimensional case, using a moment method and numerical
simulations.",0005024v1
2001-02-02,Gate-Controlled Electron Spin Resonance in a GaAs/AlGaAs Heterostructure,"The electron spin resonance (ESR) of two-dimensional electrons is
investigated in a gated GaAs/AlGaAs heterostructure. We found that the ESR
resonance frequency can be turned by means of a gate voltage. The front and
back gates of the heterostructure produce opposite g-factor shift, suggesting
that electron g-factor is being electrostatically controlled by shifting the
equilibrium position of the electron wave function from one epitaxial layer to
another with different g-factors.",0102044v1
2002-10-10,Polarization analysis of K-edge resonant x-ray scattering of germanium,"The polarization of K-edge resonant scattering at the space group
``forbidden'' (0 0 6) reflection of Ge was measured as function of the
azimuthal angle, psi. The experimental results are compared to model
calculations based on symmetry analysis of the resonant scattering tensors.",0210234v2
2003-03-11,Feshbach resonances and collapsing Bose-Einstein condensates,"We investigate the quantum state of burst atoms seen in the recent Rb-85
experiments at JILA. We show that the presence of a resonance scattering state
can lead to a pairing instability generating an outflow of atoms with energy
comparable to that observed. A resonance effective field theory is used to
study this dynamical process in an inhomogeneous system with spherical
symmetry.",0303211v1
2003-08-14,Exact Groundstates of Rotating Bose Gases close to a Feshbach Resonance,"We study the groundstates of rotating Bose gases when interactions are
affected by a nearby Feshbach resonance. We show that exact groundstates at
high angular momentum can be found analytically for a general and realistic
model for the resonant interactions. We identify parameter regimes where the
exact groundstates are exotic fractional quantum Hall states, the excitations
of which obey non-abelian exchange statistics.",0308283v1
2003-08-29,Array enhanced stochastic resonance and spatially correlated noises,"We discuss the role of spatial correlations of the noise in the array
enhanced stochastic resonance. We show numerically that the noises with
negative correlations between different sites lead to significantly larger
values of the signal-to-noise ratio than the uncorrelated noises or noises with
positive correlations. If the noise is global, the system displays only the
conventional stochastic resonance, without any array enhancement.",0308620v1
2006-05-30,Cyclic Lattice Feshbach Resonances,"In this Letter we illustrate the possible cyclic fermion pairing states
across Feshbach resonances in optical lattices. In cyclic fermion pairing, the
pairing amplitude exhibits an oscillatory behavior as the detuning varies. We
estimate the quasi-particle gaps in different regimes of the resonances.",0605743v2
1997-02-07,Cylindrical versus Spherical Resonant Antennas for Gravitational Wave Detection,"The principles and detection of gravitational waves by resonant antennas are
briefly discussed. But the main purpose of this short note is to compare the
two geometries of resonant antennas, the well-known cylindrical to the
spherical type. Some features of a two sphere observatory are also discussed.",9702016v1
1992-10-06,Complementarity of Resonant and Nonresonant Strong WW Scattering at SSC and LHC,"Signals and backgrounds for strong $WW$ scattering at the SSC and LHC are
considered. Complementarity of resonant signals in the $I=1$ $WZ$ channel and
nonresonant signals in the $I=2$ \wpwp channel is illustrated using a chiral
lagrangian with a $J=1$ \qrho resonance. Results are presented for purely
leptonic final states in the $W^{\pm}Z$, $W^+W^+ + W^-W^-$, and $ZZ$ channels.",9210216v1
1994-10-23,Resonant Neutrino Interactions and Mixing,"We investigate the resonant interaction of neutrinos in matter in the
presence of mixing. At energies near the W resonance, oscillations are absent;
the survival probability of electron antineutrinos is suppressed due to the
presence of open inelastic channels.",9410352v2
1995-03-13,Dilepton Emission From a Resonance Gas,"We consider the dilepton emission from a dense and hot hadron gas near a
critical point. The hadron gas is described as a resonance one. The dilepton
spectrum generated by vector resonances is shown to be equivalent to the one
generated by quarks.",9503309v1
1995-09-04,Lowest tensor-meson resonances contributions to the chiral perturbation theory low energy coupling constants,"The contributions of the lightest tensor-meson resonances to the low-energy
coupling constants of second order chiral perturbation theory with two flavours
are evaluated and compared with the available phenomenological information as
well as with similar results for other resonances.",9509217v1
1996-08-09,On the Thermodynamics of Chiral Symmetry Restoration,"The formulas for the temperature dependences of the non-strange and strange
quark condensates are derived by taking into account the contribution of the
massive resonances. Critical temperature of the chiral symmetry restoration
transition is established to be 190 MeV if only meson resonances are
considered, and 175 MeV if both meson and baryon resonances are taken into
account.",9608290v1
2001-12-04,Topological transitions at the resonance in gauge sector,"We discuss topological transitions during parametric resonance in the gauge
sector of electroweak theory. It is shown that the resonance leads to
separation of topological indices of the gauge and Higgs fields, resulting in
topological transitions of non-sphaleron nature.",0112053v1
2003-05-20,BABAR resonance as a new window of hadron physics,"Possible decays of four-quark mesons are studied by assigning the newly
observed BABAR resonance to a four-quark meson with C=S=I=1. It is expected
that some of them can be observed as narrow resonances. Implication of
existence of four-quark mesons in hadronic weak interactions is also discussed.",0305213v2
2003-09-25,The BABAR Resonance as a Four-quark Meson,"By assigning the narrow scalar resonance (which has been recently observed at
the B-factories) to one of iso-triplet four-quark mesons containing a charm
quark, two body decays of the four-quark mesons are studied. It is predicted
that some of them can be observed as narrow resonances.",0309279v1
2005-11-15,Recoilless Resonant Capture of Antineutrinos,"Resonant capture of antineutrinos can be accomplished by exploiting the
monoenergetic antineutrinos emitted in bound state beta-decay. Extending this
idea, I explore conditions for recoilless resonant capture in the system 3H -
3He. Observation of such transitions can set the stage for placing stringent
limits on the neutrino parameter theta-13 on an ultra-short baseline of ~9 m
and for observing the gravitational red shift of neutrinos",0511191v1
2006-11-25,Fermion resonance in quantum field theory,"We derive accurately the fermion resonance propagator by means of Dyson
summation of the self-energy contribution. It turns out that the relativistic
fermion resonance differs essentially from its boson analog.",0611314v2
1992-05-12,Renormalization group trajectories from resonance factorized S-matrices,"We propose and investigate a large class of models possessing resonance
factorized S-matrices. The associated Casimir energy describes a rich pattern
of renormalization group trajectories related to flows in the coset models
based on the simply laced Lie Algebras. From a simplest resonance S-matrix,
satisfying the ``$\phi^3$-property'', we predict new flows in non-unitary
minimal models.",9205024v1
1993-07-14,Applications of generalized special functions in stellar astrophysics,"This article gives an brief outline of the applications of generalized
special functions such as generalized hypergeometric functions, G-functions and
H-functions into the general area of nuclear energy generation and reaction
rate theory such as the energy generation in a simple stellar model and nuclear
reaction rates in non-resonant and resonant as well as screened non-resonant",9307222v1
2000-06-08,Analytic continuation and resonance-free regions for Sturm-Liouville pote ntials with power decay,"We are concerned with the Sturm-Liouville problem on the half line. We show
that when the potential $q$ is subject only to power decay at infinity the
$L^2$ solution may be continued into a sector of the so-called un-physical
sheet. This gives rise to resonance free regions and the numerical estimation
of resonances outside these regions.",0006064v1
2002-09-12,Resonances associated to a closed hyperbolic trajectory in dimension 2,"We consider resonances in the semi-classical limit, generated by a single
closed hyperbolic orbit, for an operator on ${\bf R}^2$. We determine all such
resonancess in a domain independent of the semi-classical parameter As an
application we determine all resonances generated by a saddle point in a fixed
disc around the critical energy.",0209147v1
2004-08-13,Several complex variables and the distribution of resonances in potential scattering,"We study resonances associated to Schr\""odinger operators with compactly
supported potentials on ${\mathbb R}^d$, $d\geq3$, odd. We consider compactly
supported potentials depending holomorphically on a complex parameter $z$. For
certain such families, for all $z$ except those in a pluripolar set, the
associated resonance-counting function has order of growth $d$. Our proofs use
some results from several complex variables.",0408183v1
2000-06-27,On the mean value of the energy for resonant states,"In this work we discuss possible definitions of the mean value of the energy
for a resonant (Gamow) state. The mathematical and physical aspects of the
formalism are reviewed. The concept of rigged Hilbert space is used as a
supportive tool in dealing with Gamow-resonances.",0006027v1
2002-06-07,Resonant states and classical damping,"Using Koopman's approach to classical dynamical systems we show that the
classical damping may be interpreted as appearance of resonant states of the
corresponding Koopman's operator. It turns out that simple classical damped
systems give rise to discrete complex spectra. Therefore, the corresponding
generalized eigenvectors may be interpreted as classical resonant states.",0206009v1
2002-09-04,Wigner function for damped systems,"Both classical and quantum damped systems give rise to complex spectra and
corresponding resonant states. We investigate how resonant states, which do not
belong to the Hilbert space, fit the phase space formulation of quantum
mechanics. It turns out that one may construct out of a pair of resonant states
an analog of the stationary Wigner function.",0209008v1
2004-10-18,Resonant pumping in nonlinear Klein-Gordon equation and solitary packets of waves,"Solution of the nonlinear Klein-Gordon equation perturbed by small external
force is investigated. The frequency of perturbation varies slowly and passes
through a resonance. The resonance generates a solitary packets of waves. Full
asymptotic description of this process is presented.",0410041v1
2005-03-09,The slowly passage through the resonances and wave packets with the different carriers,"Solution of the nonlinear Klein-Gordon equation perturbed by small external
force is investigated. The perturbation is represented by finite collections of
harmonics. The frequencies of the perturbation vary slowly and pass through the
resonant values consecutively. The resonances lead to the sequence of the wave
packets with the different fast oscillated carriers. Full asymptotic
description of this process is presented.",0503019v1
1993-11-23,Three-body resonances by complex scaling,"It is demonstrated that the complex scaling method can be used in practical
calculations to localize three-body resonances. Our model example emphasizes
the fact that in three-body systems several essentially different asymptotic
behaviors can appear. We show that the possibility of these different
asymptotic configurations can lead to an apparent, resonance like structure in
the three-body continuum.",9311022v1
1998-06-18,Consistent effective field-theoretic treatment of resonances with non zero width,"A systematic field theoretic formalism for treating Fermionic resonances with
non zero width is given. The implication of unitarity to coupling constants of
non local interactions is shown. The extension of the formalism to Bosonic
resonance field operators is straight forward.",9806060v2
1998-08-14,Decay theory of double giant resonances,"The decay theory of double giant resonances incorporating fluctuation
contributions of the Brink-Axel type is developed. The gamma and neutron
emission decay of Double Giant Dipole Resonances (DGDR) in 208Pb is discussed
in connection with a recent measurement.",9808040v1
1999-01-25,Resonances in the three-neutron system,"A study of 3-body resonances has been performed in the framework of
configuration space Faddeev equations. The importance of keeping a sufficient
number of terms in the asymptotic expansion of the resonance wave function is
pointed out. We investigated three neutrons interacting in selected force
components taken from realistic nn forces.",9901074v1
2002-09-28,Properties of the overtone of the isoscalar giant monopole resonance,"A semi-microscopic approach, based on the continuum-random-phase
Approximation (CRPA) method, is applied to describe the main properties
(strength function, transition density, direct-nucleon-decay branching ratios)
of the overtone of the isoscalar giant monopole resonance. Results of the
calculation are presented for 208Pb in comparison with those obtained for the
isoscalar monopole and dipole giant resonances within the same approach.",0209094v1
2003-05-02,Beyond the known baryon resonances,"eta photoproduction data on the proton up to E=2 GeV are interpreted within a
chiral constituent quark formalism, which embodies all known three and four
star resonances. This study confirms the need for a new S11 resonance, with
M=1.780 GeV and Gamma=280 MeV, already introduced in investigating lower energy
data.",0305004v1
2003-07-14,Antibound and Resonant States in Halo Nuclei,"An unified shell model scheme to evaluate simultaneously the contribution of
antibound states and Gamow resonances to the nuclear halos is presented. The
calculations, performed in the complex energy plane, are applied to the case of
$^{11}$Li. It is found that $^{11}$Li may develop a resonant state excitation
near the breakup threshold.",0307060v1
2004-08-23,Role of the baryon resonances in the eta and K+ photoproduction processes on the proton,"Very recent eta and K+ photoproduction data on the proton from threshold up
to E = 2.6 GeV are interpreted within a chiral constituent quark formalism,
which embodies all known nucleon and hyperon resonances. Possible contributions
from an additional S11 resonance are presented.",0408054v1
1999-04-09,A Variety of Giant Resonances in Metal Clusters,"Multipole electric and magnetic giant resonances in metal clusters are
reviewed and compared with their counterparts in atomic nuclei. The main
attention is paid to E1 resonance (dipole plasmon).",9904017v3
2000-03-16,Excitation of resonators by electron beams,"In this paper the main consequences of the vector theory of excitation of
resonators by particle beams are presented. Some features of excitation of
broadband radiation in longitudinal modes of the enclosed and open resonators
are discussed.",0003034v1
2000-11-21,Reversed Dark Resonance in Rb Atom Excited by a Diode Laser,"Origin of recently discovered reversed (opposite sign) dark resonances was
explained theoretically and verified experimentally. It is shown that the
reason for these resonances is a specific optical pumping of ground state level
in a transition when ground state angular momentum is smaller than the excited
state momentum.",0011051v1
2001-06-07,Resonant-state solution of the Faddeev-Merkuriev integral equations for three-body systems with Coulomb potentials,"A novel method for calculating resonances in three-body Coulombic systems is
proposed. The Faddeev-Merkuriev integral equations are solved by applying the
Coulomb-Sturmian separable expansion method. The $e^- e^+ e^-$ S-state
resonances up to $n=5$ threshold are calculated.",0106026v1
2001-12-14,Excitation of Resonators by Electron Beams,"Elements of a vector theory of open resonators and experiments on excitation
of a fundamental mode with transverse and longitudinal polarization in such
resonators are discussed.",0112041v1
2003-02-14,A composite open resonator for compact X-ray source,"The results of calculation of the finesse of a composite open resonator for
compact X-ray source are presented. The region of the resonator parameters has
been found where the finesse is changed unessentially.",0302047v1
2003-10-07,"Creation, doubling, and splitting, of vortices in intracavity second harmonic generation","We demonstrate generation and frequency doubling of unit charge vortices in a
linear astigmatic resonator. Topological instability of the double charge
harmonic vortices leads to well separated vortex cores that are shown to
rotate, and become anisotropic, as the resonator is tuned across resonance.",0310030v1
2004-10-06,On dynamical tunneling and classical resonances,"This letter establishes a firm relationship between classical nonlinear
resonances and the phenomenon of dynamical tunneling. It is shown that the
classical phase space with its hierarchy of resonance islands completely
characterizes dynamical tunneling. In particular, it is not important to invoke
criteria such as the size of the islands and presence or absence of avoided
crossings for a consistent description of dynamical tunneling in
near-integrable systems.",0410033v1
2005-02-23,Spin tune in the single resonance model with a pair of Siberian Snakes,"Snake ``resonances'' are classified in terms of the invariant spin field and
the amplitude dependent spin tune. Exactly at snake ``resonance'' there is no
continuous invariant spin field at most orbital amplitudes.",0502121v1
2005-12-21,Induced Absorption Resonance on the Open Fg = 1 -> Fe = 2 Transition of the D1 Line of the 87Rb Atom,"Induced absorption resonance on the open Fg=1 -> Fe = 2 transition of the D1
line of the 87Rb atom has been observed. The effect of atomic motion on the
formation of the resonance has been revealed. The numerical calculations are in
good agreement with experiment.",0512199v1
1997-05-08,Resonances from Higher Order S-Matrix Poles with Exponential Decay,"In analogy to Gamow vectors describing resonance states from first order
S-matrix poles, one can define Gamow vectors from higher order poles of the
S-matrix. With these vectors we are going to discuss a density operator that
describes exponentially decaying resonances from higher order poles.",9705012v1
1999-09-08,Non-Resonant Effects in Implementation of Quantum Shor Algorithm,"We simulate Shor's algorithm on an Ising spin quantum computer. The influence
of non-resonant effects is analyzed in detail. It is shown that our ``$2\pi
k$''-method successfully suppresses non-resonant effects even for relatively
large values of the Rabi frequency.",9909027v2
2001-10-10,Magnetic Resonance Force Microscopy Measurement of Entangled Spin States,"We simulate magnetic resonance force microscopy measurements of an entangled
spin state. One of the entangled spins drives the resonant cantilever
vibrations, while the other remote spin does not interact directly with the
quasiclassical cantilever. The Schr\""odinger cat state of the cantilever
reveals two possible outcomes of the measurement for both entangled spins.",0110070v1
2002-02-26,Hidden symmetries in deformed microwave resonators,"We explain the ``Hidden symmetries'' observed in wavefunctions of deformed
microwave resonators in recent experiments.We also predict that other such
symmetries can be seen in microwave resonators.",0202150v2
2003-09-29,Number of quantal resonances,"Employing the concept of time-delay, a relation is found which counts the
number of quantal resonances supported by a potential. Several simple and
advanced illustrations include a treatment of square-well, Dirac delta barrier,
an interesting physical situation from neutron reflectometry, and the Delta
resonance appearing in the scattering of \pi meson from proton.",0309206v1
2004-12-23,Schroedinger Cat States of a Nanomechanical Resonator,"We present a scheme of generating large-amplitude Schr\""{o}dinger cat states
and entanglement in a coupled system of nanomechanical resonator and single
Cooper pair box (SCPB), without being limited by the magnitude of the coupling.
It is shown that the entanglement between the resonator and the SCPB can be
detected by a spectroscopic method.",0412185v1
2005-01-06,On hybrid states of two and three level atoms,"We calculate atom-photon resonances in the Wigner-Weisskopf model, admitting
two photons and choosing a particular coupling function. We also present a
rough description of the set of resonances in a model for a three-level atom
coupled to the photon field. We give a general picture of matter-field
resonances these results fit into.",0501027v1
2005-12-25,Implementation of quantum algorithms with resonant interactions,"We propose a scheme for implementing quantum algorithms with resonant
interactions. Our scheme only requires resonant interactions between two atoms
and a cavity mode, which is simple and feasible. Moreover, the implementation
would be an important step towards the fabrication of quantum computers in
cavity QED system.",0512230v2
2007-05-28,Calculations of ${\cal O}(p^6)$ Resonance Coupling Constants in the Scalar Sector of the ENJL Model,"We derive the scalar resonance coupling constants of resonance chiral theory
from the Extended Nambu Jona-Lasinio model by using heat-kernel expansion.",0705.4052v1
2007-07-04,Relativistic five-quark equations and a narrow N(1688) resonance,"The relativistic five-quark equations are found in the framework of the
dispersion relation technique. The five-quark amplitude for the N(1688)
resonance including u-, d- quarks is calculated. The pole of this amplitude
determines the mass of non-strange pentaquark M=1686 MeV and the width about
7MeV. The results are in good agreement with the evidence for a narrow N(1688)
resonance.",0707.0553v1
2007-09-20,Parametric Resonance Enhancement in Neutron Interferometry and Search for Non-Newtonian Gravity,"The parametric resonance enhancement of the phase of neutrons due to
non-Newtonian anomalous gravitational is considered. The existence of such
resonances are confirmed by numerical calculations. A possible experimental
scheme for the observation of this effect is discussed based on an existing
neutron interferometer design.",0709.3266v1
2007-10-02,Nonlinear Optical Spectroscopy of Photonic Metamaterials,"We have obtained spectra of second-harmonic generation, third harmonic
generation, and four-wave mixing from a fishnet metamaterial around its
magnetic resonance. The resonant behaviors are distinctly different from those
for ordinary materials. They result from the fact that the resonance is
plasmonic, and its enhancement appears through the local field in the
nanostructure.",0710.0599v1
2008-01-04,Fermions in Deep Optical Lattice under p-wave Feshbach Resonance,"We investigate theoretically the energy levels of two identical Fermions in a
harmonic potential well under p-wave Feshbach resonance. The magnetic fields
needed to affect the energy levels differ strongly among the levels, and they
can be at values far from the free space resonant field.",0801.0636v1
2008-01-04,Spin-hybrid-phonon resonance in anisotropic quantum dots,"We have studied the absorption of electromagnetic radiation of an anisotropic
quantum dot taking into account the spin-flip processes that is associated with
the interaction of the electrons with optical phonons. It is shown that these
processes lead to the resonance absorption. Explicit formula is derived for the
absorption coefficient. The positions of the resonances peaks are found.",0801.0666v1
2008-02-17,Structure of the Nucleon and Roper Resonance with Diquark Correlations,"We investigate the electric form factors of the nucleon and Roper resonance
using a quark-diquark model. We find that the charge radii of the nucleon and
Roper resonance are almost the same in size.",0802.2366v1
2008-04-14,Direct-decay properties of Giant Resonances,"A semi-microscopic approach based on the continuum-RPA method and a
phenomenological treatment of the spreading effect is developed and applied to
describe direct-decay properties of a few isovector giant resonances.
Capabilities of the approach to describe giant-resonance gross properties are
also checked.",0804.2160v1
2008-04-21,Enhanced Production of Delta(1230) and Sigma(1385) Resonances,"Yields of Delta(1230), Sigma(1385) resonances produced in heavy ion
collisions are studied within the framework of a kinetic master equation. The
time evolution is driven by the process Delta(1230) \leftrightarrow N \pi,
Sigma(1385) \leftrightarrow \Lambda \pi . We obtain resonance yield both below
and above chemical equilibrium, depending on initial hadronization condition
and separation of kinetic and chemical freeze-out.",0804.3352v1
2008-04-22,Quantum noise in a nano mechanical Duffing resonator,"We determine the small signal gain and noise response of an amplifier based
on the nonlinear response of a quantum nanomechanical resonator. The resonator
is biased in the nonlinear regime by a strong harmonic bias force and we
determine the response to a small additional driving signal detuned with
respect to the bias force.",0804.3618v1
2008-06-20,Slow passage through parametric resonance for a weakly nonlinear dispersive wave,"A solution of the nonlinear Klein-Gordon equation perturbed by a parametric
driver is studied. The frequency of the parametric perturbation varies slowly
and passes through a resonant value. It yields a change in a solution. We
obtain a connection formula for the asymptotic solution before and after the
resonance.",0806.3338v1
2008-06-26,"Delta resonances, quark models, chiral symmetry and AdS/QCD","The mass spectrum of Delta resonances is compared to predictions based on
three quark-model variants, to predictions assuming that chiral symmetry is
restored in high-mass baryon resonances, and to predictions derived from
AdS/QCD. The latter approach yields a nearly perfect agreement when the
confinement property of QCD is modeled by a soft wall in AdS.",0806.4290v1
2008-10-01,Sequential resonant tunneling in quantum cascade lasers,"A model of sequential resonant tunneling transport between two-dimensional
subbands that takes into account explicitly elastic scattering is investigated.
It is compared to transport measurements performed on quantum cascade lasers
where resonant tunneling processes are known to be dominating. Excellent
agreement is found between experiment and theory over a large range of current,
temperature and device structures.",0810.0146v1
2008-12-17,Two pairs of interacting EBs towards the LMC in the OGLE database,"A single point source on the OGLE LMC database shows the characteristics of
two superimposed eclipsing binaries (EBs). The two EBs happen to have periods
very close to the 3:2 resonance. The telescope's small PSF and the apparent
resonance between the two EBs raises the suspicion that this is not chance
alignment but rather a compact hierarchical system of two pairs of interacting
EBs in 3:2 resonance.",0812.3386v1
2008-12-19,Entanglement of qubits via a nonlinear resonator,"Coherent coupling of two qubits mediated by a nonlinear resonator is studied.
It is shown that the amount of entanglement accessible in the evolution depends
both on the strength of nonlinearity in the Hamiltonian of the resonator and on
the initial preparation of the system. The created entanglement survives in the
presence of decoherence.",0812.3791v3
2008-12-24,Feshbach molecule production in fermionic atomic gases,"This paper examines the problem of molecule production in an atomic fermionic
gas close to an s-wave Feshbach resonance by means of a magnetic field sweep
through the resonance. The density of molecules at the end of the process is
derived for narrow resonance and slow sweep.",0812.4474v1
2009-02-20,Dynamical Models of the Excitations of Nucleon Resonances,"The development of a dynamical model for investigating the nucleon resonances
using the reactions of meson production from \pi N, \gamma N, N(e,e'), and
N(\nu,{\it l}) reactions is reviewed. The results for the \Delta (1232) state
are summarized and discussed. The progress in investigating higher mass nucleon
resonances is reported.",0902.3653v1
2009-06-02,Optomechanical coupling in photonic crystal supported nanomechanical waveguides,"We report enhanced optomechanical coupling by embedding a nano-mechanical
beam resonator within an optical race-track resonator. Precise control of the
mechanical resonator is achieved by clamping the beam between two low-loss
photonic crystal waveguide couplers. The low insertion loss and the rigid
mechanical support provided by the couplers yield both high mechanical and
optical Q-factors for improved signal quality.",0906.0407v1
2009-08-20,Zero width resonance (spectral singularity) in a complex PT-symmetric potential,"We show that the complex PT-Symmetric potential, $V(x)=-V_1 {sech}^2x + iV_2
{sech}x ~\tanh x, $, entails a single zero-width resonance (spectral
singularity) when $V_1+|V_2|=4n^2+4n+{3\over 4}(n=1,2,3.., |V_2|>|V_1|+
{{sgn}(V_1) \over 4})$ and the positive resonant energy is given as $E_*={1
\over 4}[|V_2|-(1/4+V_1)]$.",0908.2876v1
2009-09-22,New physics search at the LHC via Z' resonance,"A new Abelian gauge symmetry U(1)' is well motivated to extend the standard
model or supersymmetric standard model. Leptonic Z' resonances are clean
signals even at the hadron colliders. We discuss how 4-lepton and 6-lepton Z'
resonances can help the search for Supersymmetry and Higgs, respectively, at
the LHC.",0909.4049v1
2009-10-29,Giant enhancement of electric field between two close metallic grains due to plasmonic resonance,"We theoretically examine plasmonic resonance between two close metallic
grains separated by a gap of width much less than the length of the incident
electromagnetic wave. Resonance conditions are established and the electric
field enhancement is found. Our general arguments are confirmed by analytic
solution of the problem for simplest geometries. We discuss an extension of our
results to more complex cases.",0910.5716v1
2010-02-04,Subharmonic resonance of global climate to solar forcing,"It is shown that, the wavelet regression detrended fluctuations of the
monthly global temperature data (land and ocean combined) for the period
1880-2009yy, are completely dominated by one-third subharmonic resonance to
annual forcing (both natural and anthropogenically induced). Role of the
oceanic Rossby waves and the resonance contribution to the El Nino phenomenon
have been discussed in detail.",1002.1024v1
2010-02-08,An Adiabatic Theorem for Resonances,"We prove a robust extension of the quantum adiabatic theorem. The theorem
applies to systems that have resonances instead of bound states, and to systems
for which just an approximation to a bound state is known. To demonstrate the
theorem's usefulness in a concrete situation, we apply it to shape resonances.",1002.1741v1
2010-09-17,The resonant B1II+B1II binary BI108,"BI108 is a luminous variable star in the Large Magellanic Cloud classified
B1II. The variability consists of two resonant periods (3:2), of which only one
is orbital, however. We discuss possible mechanisms responsible for the second
period and its resonant locking.",1009.3511v1
2010-10-16,Basics of Resonance Chiral Theory,"We review the main components that have to be considered, within Resonance
Chiral Theory, in the study of processes whose dynamics is dominated by hadron
resonances. We show its application in the study of the tau -> (3 pion) nu_tau
decay.",1010.3360v1
2010-11-02,On the nature of the Roper resonance,"The lightest N* state, N(1440) P11, also known as Roper resonance, has
puzzled physicists for decades. A large variety of theoretical models aimed to
understand its properties have been proposed. Some of them are briefly reviewed
here, together with the hadronic processes where the Roper resonance is
revealed or plays an important role.",1011.0609v1
2010-12-14,A general model of resonance capture in planetary systems: First and second order resonances,"Mean motion resonances are a common feature of both our own Solar System and
of extrasolar planetary systems. Bodies can be trapped in resonance when their
orbital semi-major axes change, for instance when they migrate through a
protoplanetary disc. We use a Hamiltonian model to thoroughly investigate the
capture behaviour for first and second order resonances. Using this method, all
resonances of the same order can be described by one equation, with
applications to specific resonances by appropriate scaling. We focus on the
limit where one body is a massless test particle and the other a massive
planet. We quantify how the the probability of capture into a resonance depends
on the relative migration rate of the planet and particle, and the particle's
eccentricity. Resonant capture fails for high migration rates, and has
decreasing probability for higher eccentricities. More massive planets can
capture particles at higher eccentricities and migration rates. We also
calculate libration amplitudes and the offset of the libration centres for
captured particles, and the change in eccentricity if capture does not occur.
Libration amplitudes are higher for larger initial eccentricity. The model
allows for a complete description of a particle's behaviour as it successively
encounters several resonances. We discuss implications for several scenarios:
(i) Planet migration through gas discs trapping other planets or planetesimals
in resonances. (ii) Planet migration through a debris disc. (iii) Dust
migration through PR drag. The Hamiltonian model will allow quick
interpretation of the resonant properties of extrasolar planets and Kuiper Belt
Objects, and will allow synthetic images of debris disc structures to be
quickly generated, which will be useful for predicting and interpreting disc
images made with ALMA, Darwin/TPF or similar missions. [Abridged]",1012.3079v1
2011-05-25,Counting the Resonances in High and Even Dimensional Obstacle Scattering,"In this paper, we give a polynomial lower bound for the resonances of
$-\Delta$ perturbed by an obstacle in even-dimensional Euclidean spaces,
$n\geq4$. The proof is based on a Poisson Summation Formula which comes from
the Hadamard factorization theorem in the open upper complex plane. We take
advantage of the singularity of regularized wave trace to give the
pole/resonance counting function over the principal branch of logarithmic plane
a lower bound.",1105.4972v1
2011-08-15,Quantum logic gates for superconducting resonator qudits,"We study quantum information processing using superpositions of Fock states
in superconducting resonators, as quantum $d$-level systems (qudits). A
universal set of single and coupled logic gates is theoretically proposed for
resonators coupled by superconducting circuits of Josephson juctions. These
gates use experimentally demonstrated interactions, and provide an attractive
route to quantum information processing using harmonic oscillator modes.",1108.2984v2
2011-09-24,5s correlation confinement resonances in Xe-endo-fullerenes,"Spectacular trends in the modification of the Xe 5s photoionization via
interchannel coupling with confinement resonances emerging in the Xe 4d giant
resonance upon photoionization of the Xe@C60, Xe@C240 and Xe@C60@C240
endo-fullerenes are theoretically unraveled and interpreted.",1109.5293v1
2011-10-26,Entangled State Synthesis for Superconducting Resonators,"We present a theoretical analysis of methods to synthesize entangled states
of two superconducting resonators. These methods use experimentally
demonstrated interactions of resonators with artificial atoms, and offer
efficient routes to generate nonclassical states. We analyze physical
implementations, energy level structure, and the effects of decoherence through
detailed dynamical simulations.",1110.5801v1
2012-02-05,Searches for high mass resonances with the CMS detector,"New heavy resonances are predicted by many extensions of the standard model
of particle physics. Recent results for high mass resonance searches with the
Compact Muon Solenoid detector, in the diphoton, dilepton, dijet and ttbar
channels, are discussed. Limits for numerous benchmark models are presented.",1202.0963v1
2012-03-13,Trapping in three-planet resonances during gas-driven migration,"We study the establishment of three-planet resonances -similar to the Laplace
resonance in the Galilean satellites- and their effects on the mutual
inclinations of the orbital planes of the planets, assuming that the latter
undergo migration in a gaseous disc. In particular, we examine the resonance
relations that occur, by varying the physical and initial orbital parameters of
the planets (mass, initial semi-major axis and eccentricity) as well as the
parameters of the migration forces (migration rate and eccentricity damping
rate), which are modeled here through a simplified analytic prescription. We
find that, in general, for planetary masses below 1.5 M_J, multiple-planet
resonances of the form n3:n2:n1=1:2:4 and 1:3:6 are established, as the inner
planets, m1 and m2, get trapped in a 1:2 resonance and the outer planet m3
subsequently is captured in a 1:2 or 1:3 resonance with m2. For mild
eccentricity damping, the resonance pumps the eccentricities of all planets on
a relatively short time-scale, to the point where they enter an
inclination-type resonance (as in Libert & Tsiganis 2011); then mutual
inclinations can grow to ~35{\deg}, thus forming a ""3-D system"". On the other
hand, we find that trapping of m2 in a 2:3 resonance with m1 occurs very
rarely, for the range of masses used here, so only two cases of capture in a
respective three-planet resonance were found. Our results suggest that trapping
in a three-planet resonance can be common in exoplanetary systems, provided
that the planets are not very massive. Inclination pumping could then occur
relatively fast, provided that eccentricity damping is not very efficient so
that at least one of the inner planets acquires an orbital eccentricity higher
than e=0.3.",1203.2960v1
2012-06-04,Circuit QED using a semiconductor double quantum dot,"Vacuum Rabi splitting is observed in a coupled qubit-resonator system
consisting of a GaAs double quantum dot and a coplanar waveguide resonator.
Derived values of the qubit-resonator coupling strength and the decoherence
rate indicate strong coupling, which assures distinct vacuum Rabi oscillation
in the system. The amplitude of decoherence is reasonably interpreted in terms
of the coupling of electrons to piezoelectric acoustic phonons in GaAs.",1206.0674v1
2012-06-19,Resonances and fluctuations in the statistical model,"We describe how the study of resonances and fluctuations can help constrain
the thermal and chemical freezeout properties of the fireball created in heavy
ion collisions. This review is based on [1-5].",1206.4198v1
2012-06-20,Roton Parametric Resonance,"Parametric excitation of rotons by oscillating electric field exhibits a
narrow resonance at the roton minimum frequency. The resonance width is in good
agreement with experimental results on the microwave absorption in superfluid
helium.",1206.4592v2
2012-06-29,Multiplicity of solutions for gradient systems under strong resonance at the first eigenvalue,"In this paper we establish existence and multiplicity of solutions for an
elliptic system which has strong resonance at first eigenvalue. To describe the
resonance, we use an eigenvalue problem with indefinite weight. In all results
we use Variational Methods.",1206.7097v1
2012-09-07,Electromagnetic properties of baryon resonances,"Longitudinal and transverse transition form factors for most of the four-star
nucleon resonances have been obtained from high-quality cross section data and
polarization observables measured at MAMI, ELSA, BATES, GRAAL and CEBAF. As an
application, we further show how the transition form factors can be used to
obtain empirical transverse charge densities. Contour plots of the thus derived
densities are shown and compared for the Roper and S11 nucleon resonances.",1209.1537v1
2012-09-10,Estimates of 1D resonances in terms of potentials,"We discuss resonances for Schr\""odinger operators with compactly supported
potentials on the line and the half-line. We estimate the sum of the negative
power of all resonances and eigenvalues in terms of the norm of the potential
and the diameter of its support. The proof is based on harmonic analysis and
Carleson measures arguments.",1209.2109v2
2012-10-26,"Hadron resonances, large Nc, and the half-width rule","We suggest using the half-width rule to make an estimate of the 1/Nc errors
in hadronic models containing resonances. We show simple consequences ranging
from the analysis of meson Regge trajectories, the hadron resonance gas at
finite temperature and generalized hadronic form factors.",1210.7153v1
2012-10-29,Orientation Sensitive Terahertz Resonances Observed in Protein Crystals,"A method is presented for measuring anisotropic THz response for small
crystals, Crystal Anisotropy Terahertz Microscopy (CATM). Sucrose CATM
measurements find the expected anisotropic phonon resonances. CATM measurements
of protein crystals find the expected broadband water absorption is suppressed
and strong orientation and hydration dependent resonant features.",1210.7531v1
2012-10-29,Resonance free regions for nontrapping manifolds with cusps,"We prove resolvent estimates for nontrapping manifolds with cusps which imply
the existence of arbitrarily wide resonance free strips, local smoothing for
the Schrodinger equation, and resonant wave expansions. We obtain lossless
limiting absorption and local smoothing estimates, but the estimates on the
holomorphically continued resolvent exhibit losses. We prove that these
estimates are optimal in certain respects.",1210.7736v1
2013-01-30,Methods for Analyzing Resonances in Atomic Scattering,"Resonances, which are also described as autoionizing or quasi-bound states,
play an important role in the scattering of atoms and ions with electrons. The
current article is an overview of the main methods, including a
recently-proposed one, that are used to find and analyze resonances.",1301.7222v2
2013-10-14,"Bilinear dispersive estimates via space-time resonances, part II: dimensions 2 and 3","Consider a bilinear interaction between two linear dispersive waves with a
generic resonant structure (roughly speaking, space and time resonant sets
intersect transversally). We derive an asymptotic equivalent of the solution
for data in the Schwartz class, and bilinear dispersive estimates for data in
weighted Lebesgue spaces. An application to water waves with infinite depth,
gravity and surface tension is also presented.",1310.3659v1
2013-12-02,Coherent excitation-selective spectroscopy in planar metamaterials,"In a proof-of-principle experiment with metamaterials exhibiting electric
dipolar and magnetic dipolar resonances, we demonstrated that the electric and
magnetic resonances can be separately switches off and on by positioning the
metamaterials along a standing wave, while both resonances are present in
travelling-wave spectra.",1312.0524v1
2013-12-08,Probing semiconductor quantum dot state and manipulation with superconducting transmission line resonator,"A coupled system of a superconducting transmission line resonator with a
semiconductor double quantum dot is analyzed. We simulate the phase shift of
the microwave signal in the resonator, which is sensitive to the quantum dot
qubit state and manipulation. The measurement quality is sufficiently high and
the results demonstrate a solid-state quantum processor based on this type of
circuit can be envisioned.",1312.2271v1
2013-12-16,Collective resonant modes of a meta-surface,"A periodic layer of resonant scatterers is considered in the dipolar
approximation. An asymptotic expression for the field diffracted is given in
terms of an impedance operator. It is shown that surface Bloch modes appear as
a collective effect due to the resonances of the scatterers.",1312.4273v1
2013-12-17,Astrophysical radiative neutron capture on 10B taking into account resonance at 475 keV,"The possibility of the description of the available experimental data for
cross sections of the neutron capture reaction on 10B at thermal and
astrophysical energies, taking into account the resonance at 475 keV, was
considered within the framework of the modified potential cluster model with
forbidden states and accounting for the resonance behavior of the scattering
phase shifts.",1312.4690v1
2014-01-19,Scattering Resonances of Convex Obstacles for general boundary conditions,"We study the distribution of resonances for smooth strictly convex obstacles
under general boundary conditions. We show that under a pinched curvature
condition for the boundary of the obstacle, the resonances are separated into
cubic bands and the distribution in each bands satisfies Weyl's law.",1401.4741v1
2014-07-24,Fano collective resonance as complex mode in a two dimensional planar metasurface of plasmonic nanoparticles,"Fano resonances are features in transmissivity/reflectivity/absorption that
owe their origin to the interaction between a bright resonance and a dark
(i.e., sub-radiant) narrower resonance, and may emerge in the optical
properties of planar two-dimensional (2D) periodic arrays (metasurfaces) of
plasmonic nanoparticles. In this Letter, we provide a thorough assessment of
their nature for the general case of normal and oblique plane wave incidence,
highlighting when a Fano resonance is affected by the mutual coupling in an
array and its capability to support free modal solutions. We analyze the
representative case of a metasurface of plasmonic nanoshells at ultraviolet
frequencies and compute its absorption under TE- and TM-polarized, oblique
plane-wave incidence. In particular, we find that plasmonic metasurfaces
display two distinct types of resonances observable as absorption peaks: one is
related to the Mie, dipolar resonance of each nanoparticle; the other is due to
the forced excitation of free modes with small attenuation constant, usually
found at oblique incidence. The latter is thus an array-induced collective Fano
resonance. This realization opens up to manifold flexible designs at optical
frequencies mixing individual and collective resonances. We explain the
physical origin of such Fano resonances using the modal analysis, which allows
to calculate the free modes with complex wavenumber supported by the
metasurface. We define equivalent array dipolar polarizabilities that are
directly related to the absorption physics at oblique incidence and show a
direct dependence between array modal phase and attenuation constant and Fano
resonances. We thus provide a more complete picture of Fano resonances that may
lead to the design of filters, energy-harvesting devices, photodetectors, and
sensors at ultraviolet frequencies.",1407.6656v2
2014-12-15,Charmed baryonic resonances in medium,"We discuss the behavior of dynamically-generated charmed baryonic resonances
in matter within a unitarized coupled-channel model consistent with heavy-quark
spin symmetry. We analyze the implications for the formation of $D$-meson bound
states in nuclei and the propagation of $D$ mesons in heavy-ion collisions from
RHIC to FAIR energies.",1412.4811v1
2015-01-30,The Astrophysics of Resonant Orbits in the Kerr Metric,"This paper gives a complete characterization of resonant orbits in a Kerr
spacetime. A resonant orbit is defined as a geodesic for which the longitudinal
and radial orbital frequencies are commensurate. Our analysis is based on
expressing the resonance condition in its most symmetric form using Carlson's
integrals. We provide a number of concise formulae for the dependence of
resonances on the system parameters. Resonant effects may be observable during
the in-spiral of a compact object into a super-massive black hole. When the
slowly evolving orbital frequencies pass through a series of low-order
resonances, rapid changes in the orbital parameters could produce measurable
phase shifts in the emitted gravitational radiation (GW). Resonant orbits may
also capture dust leading to electromagnetic emission. The KAM theorem
indicates that, low order resonant orbits demarcate the regions where the onset
of chaos could occur around a perturbed black-hole. We find that the 1/2 and
2/3 resonances occur at ~4 and 5.4 Schwarzschild radii (Rs) from the event
horizon. For compact object in-spirals around super-massive black holes, this
region lies within the sensitivity band of space-based GW detectors. For Sgr
A*, length scales of ~41 and 55 microarcseconds and timescales of 50 and 79 min
respectively should be associated with resonant effects, if Sgr A* is
non-spinning. Spin decreases these values by up to ~32% and ~28%. These
length-scales are potentially resolvable with VLBI measurements. We find that
all low-order resonances are localized to the strong field region r < 50 Rs.
This fact guarantees the validity of using approximations based on averaging to
model the frequency evolution of a test object in region 50 Rs <r <1000 Rs. The
systematic determination of the multipole moments of the central object by
observing the orbit of a pulsar, free of chaotic effects, is thus possible.",1501.07728v1
2015-03-22,Synchrotron radiation of dissipative solitons in optical fiber cavities,"New resonant emission of dispersive waves by oscillating solitary structures
is considered analytically and numerically. The resonance condition for the
radiation is derived and it is demonstrated that the predicted resonances match
the spectral lines observed in numerical simulations perfectly. The complex
recoil of the radiation on the soliton dynamics is discussed.",1503.06405v1
2015-05-04,Scattering resonances as viscosity limits,"Using the method of complex scaling we show that scattering resonances of $ -
\Delta + V $, $ V \in L^\infty_{\rm{c}} ( \mathbb R^n ) $, are limits of
eigenvalues of $ - \Delta + V - i \epsilon x^2 $ as $ \epsilon \to 0+ $. That
justifies a method proposed in computational chemistry and reflects a general
principle for resonances in other settings.",1505.00721v1
2015-07-07,Long-time existence and resonant approximation for the quadratic nonlinear wave equation with an anisotropic harmonic trapping,"We establish long-time existence and uniqueness for the 2D wave equation with
a harmonic potential in one direction. This proof relies on a fine study of the
so-called space-time resonances of the equation. Then we derive a resonant
system for this equation and we prove that it is a satisfying approximation for
the original equation.",1507.01683v1
2015-07-28,Linear Elliptic equations with nonlinear boundary conditions under strong resonance conditions,"In this work we establish existence and multiplicity of solutions for
elliptic problem with nonlinear boundary conditions under strong resonance
conditions at infinity. The nonlinearity is resonance at infinity and the reso-
nance phenomena occurs precisely in the first Steklov eigenvalue problem. In
all results we use Variational Methods, Critical Groups and the Morse Theory.",1507.07989v1
2015-09-10,Uniform hyperbolicity of invariant cylinder,"For a nearly integrable Hamiltonian systems $H=h(p)+\epsilon P(p,q)$ with
$(p,q)\in\mathbb{R}^3\times\mathbb{T}^3$, large normally hyperbolic invariant
cylinders exist along the whole resonant path, except for the
$\sqrt{\epsilon}^{1+d}$-neighborhood of finitely many double resonant points.
It allows one to construct diffusion orbits to cross double resonance.",1509.03160v1
2015-11-03,Nonadiabatic holonomic single-qubit gates in off-resonant $Λ$ systems,"We generalize nonadiabatic holonomic quantum computation in a resonant
$\Lambda$ configuration proposed in [New J. Phys. 14 (2012) 103035] to the case
of off-resonant driving lasers. We show that any single-qubit holonomic gate
can be realized by separately varying the detuning, amplitude, and phase of the
lasers.",1511.00911v1
2016-03-22,Widths of highly excited shape resonances,"We study the widths of shape resonances for the semiclassical
multi-dimensional Schr\""odinger operator, in the case where the frequency
remains close to some value strictly larger than the bottom of the well. Under
a condition on the behavior of the resonant state inside the well, we obtain an
optimal lower bound for the widths.",1603.06791v1
2016-07-04,Molecular predissociation resonances near an energy-level crossing II: Vector field interaction,"We study the resonances of a two-by-two semiclassical system of one
dimensional Schr\""odinger operators, near an energy where the two potentials
intersect transversally, one of them being bonding, and the other one
anti-bonding. Assuming that the interaction is a vector-field, we obtain
optimal estimates on the location and on the widths of these resonances.",1607.00778v1
2017-08-27,Resonances on regular tree graphs,"We investigate the distribution of the resonances near spectral thresholds of
Laplace operators on regular tree graphs with $k$-fold branching, $k \geq 1$,
perturbed by nonself-adjoint exponentially decaying potentials. We establish
results on the absence of resonances which in particular involve absence of
discrete spectrum near some sectors of the essential spectrum of the operators.",1708.08032v1
2010-05-11,Can Centre Surround Model Explain the Enhancement of Visual Perception through Stochastic Resonance?,"We demonstrate the ability of centre surround model for simulating the
enhancement of contrast sensitivity through stochastic resonance observed in
psychophysical experiments. We also show that this model could be used to
simulate the contrast sensitivity function through stochastic resonance. The
quality of the fit of measured contrast sensitivity function to the simulated
data is very good.",1005.1830v1
2010-05-25,Proton Sea Quark Flavour Asymmetry and Roper Resonance,"We study the proton and the Roper resonance together with the meson cloud
model, by constructing a Hamiltonian matrix and solving the eigenvalue
equation. The proton sea quark flavour asymmetry and some properties of the
Roper resonance are thus reproduced in one scheme.",1005.4550v2
2013-08-05,Di-jet resonances at future hadron colliders: A Snowmass whitepaper,"I investigate the sensitivity of future hadron colliders to di-jet resonances
arising from Z' or coloron models. The projected discovery potential and
exclusion limits for these resonances is presented in the coupling vs. mass
plane, which highlights both the increased mass reach from higher energy
machines as well as the improved coupling sensivity from larger luminosity.",1308.1077v1
2013-08-21,Overstable Librations can account for the Paucity of Mean Motion Resonances among Exoplanet Pairs,"We assess the multi-planet systems discovered by the Kepler satellite in
terms of current ideas about orbital migration and eccentricity damping due to
planet-disk interactions. Our primary focus is on mean motion resonances. Only
a few percent of planet pairs are in close proximity to a resonance. However,
predicted migration rates (parameterized by $\tau_n=n/{|\dot n|}$) imply that
during convergent migration most planets would have been captured into first
order resonances. Eccentricity damping (parameterized by $\tau_e=e/{|\dot e|}$)
offers a plausible resolution. Estimates suggest $\tau_e/\tau_n\sim (h/a)^2\sim
10^{-2}$, where $h/a$ is the ratio of disk thickness to radius. Together,
eccentricity damping and orbital migration give rise to an equilibrium
eccentricity, $e_{eq}\sim(\tau_e/\tau_n)^{1/2}$. Capture is permanent provided
$e_{eq}\lesssim \mu^{1/3}$, where $\mu$ denotes the planet to star mass ratio.
But for $e_{eq}\gtrsim \mu^{1/3}$, capture is only temporary because librations
around equilibrium are overstable and lead to passage through resonance on
timescale $\tau_e$. Most Kepler planet pairs have $e_{eq}>\mu^{1/3}$. Since
$\tau_n>> \tau_e$ is the timescale for migration between neighboring
resonances, only a modest percentage of pairs end up trapped in resonances
after the disk disappears. Planet pairs close to a mean motion resonance
typically exhibit period ratios 1-2% larger than those for exact resonance. The
direction of this shift undoubtedly reflects the same asymmetry that requires
convergent migration for resonance capture. Permanent resonance capture at
these separations from exact resonance would demand $\mu
(\tau_n/\tau_e)^{1/2}\gtrsim 0.01$, a value that estimates of $\mu$ from
transit data and $(\tau_e/\tau_n)^{1/2}$ from theory are insufficient to match.
Plausible alternatives involve eccentricity damping during or after disk
dispersal. (Abridged)",1308.4688v2
2016-11-12,Numerical Modeling of MEMS Resonators,"Microelectromechanical systems (MEMS) resonators serve as frequency selective
components in applications ranging from biology to communications. In this
paper, the dynamic behavior of an RF MEMS disk resonator is formulated using an
analytical method.",1611.05310v2
2017-01-20,An infinite dimensional KAM theorem with application to two dimensional completely resonant beam equation,"In this paper we consider the completely resonant beam equation on \T^2 with
cubic nonlinearity on a subspace of L^2 (\T^2) which will be explained later.
We establish an abstract infinite dimensional KAM theorem and apply it to the
completely resonant beam equation. We prove the existence of a class of Whitney
smooth small amplitude quasi-periodic solutions corresponding to finite
dimensional tori.",1701.05725v1
2008-07-10,Absence of resonant decay for metastable vacua in gauge theories of scalar fields,"We prove the impossibility of resonant decay of a metastable vacuum in a
theory of a scalar field coupled to a gauge field. Our result extends to gauge
theories of scalar fields a recent no go theorem for resonant tunneling in a
pure scalar field theory.",0807.1732v1
2009-12-20,Coulomb Excitation of Multi-Phonon Levels of the Giant Dipole Resonance,"A closed expression is obtained for the cross-section for Coulomb excitation
of levels of the giant dipole resonance of given angular momentum and phonon
number. Applications are made to the Goldhaber-Teller and Steinwedel-Jensen
descriptions of the resonance, at non-relativistic and relativistic bombarding
energies.",0912.4057v1
2011-11-16,Generation of Kerr Frequency Combs in Resonators with Normal GVD,"We show via numerical simulation that Kerr frequency combs can be generated
in a nonlinear resonator characterized with normal group velocity dispersion
(GVD). We find the spectral shape of the comb and temporal envelope of the
corresponding optical pulses formed in the resonator.",1111.3907v1
2012-01-17,Piezoelectric resonance in Rochelle salt: the contribution of diagonal strains,"Within the framework of two-sublattice Mitsui model with taking into account
the shear strain $\varepsilon_4$ and the diagonal strains $\varepsilon_2$ and
$\varepsilon_3$, a dynamic dielectric response of Rochelle salt X-cuts is
considered. Experimentally observed phenomena of crystal clamping by high
frequency electric field, piezoelectric resonance and microwave dispersion are
described. It is shown that the lowest resonant frequency is always associated
with the $\varepsilon_4$ shear mode",1201.3482v1
2014-05-21,A note on the resonance counting function for surfaces with cusps,"We prove sharp upper bounds for the number of resonances in boxes of size 1
at high frequency for the Laplacian on finite volume surfaces with hyperbolic
cusps. As a corollary, we obtain a Weyl asymptotic for the number of resonances
in balls of size $T \to \infty$ with remainder $O(T^{3/2})$.",1405.5445v1
2016-12-09,A General Theory for Bandgap Estimation in Locally Resonant Metastructures,"Locally resonant metamaterials are characterized by bandgaps at wavelengths
that are much larger than the lattice size, enabling low-frequency vibration
attenuation. Typically, bandgap analyses and predictions rely on the assumption
of traveling waves in an infinite medium, and do not take advantage of modal
representations typically used for the analysis of the dynamic behavior of
finite structures. Recently, we developed a method for understanding the
locally resonant bandgap in uniform finite metamaterial beams using modal
analysis. Here we extend that framework to general locally resonant
metastructures with specified boundary conditions using a general operator
formulation. Using this approach, along with the assumption of an infinite
number of resonators tuned to the same frequency, the frequency range of the
locally resonant bandgap is easily derived in closed form. Furthermore, the
bandgap expression is shown to be the same regardless of the type of vibration
problem under consideration, depending only on the added mass ratio and target
frequency. It is shown that the number of resonators required for the bandgap
to appear increases with the target frequency range, i.e. respective modal
neighborhood. Furthermore, it is observed that there is an optimal, finite
number of resonators which gives a bandgap that is wider than the
infinite-absorber bandgap, and that the optimal number of resonators increases
with target frequency and added mass ratio. As the number of resonators becomes
sufficiently large, the bandgap converges to the derived infinite-absorber
bandgap. The derived bandgap edge frequencies are shown to agree with results
from dispersion analysis using the plane wave expansion method. Numerical and
experimental investigations are performed regarding the effects of mass ratio,
non-uniform spacing of resonators, and parameter variations among the
resonators.",1612.03130v1
2016-12-10,Resonant Raman imaging of MoS2-substrate interaction,"We report a study of long-range MoS2-substrate interaction using resonant
Raman imaging. We observed a strong thickness-dependent peak shift of a
Raman-forbidden mode that can be used as a new method of determining the
thickness of multilayered MoS2 flakes. In addition, dependence of the Raman
scattering intensity on thickness is explained by the interference enhancement
theory. Finally, the resonant Raman spectra on different substrates are
analysed.",1612.03354v1
2017-07-14,Multiple nonlinear resonances and frequency combs in bottle microresonators,"We introduce the generalized Lugiato-Lefever equation describing nonlinear
effects in the bottle microresonators. We demonstrate that the nonlinear modes
of these resonators can form multiple coexisting and overlapping nonlinear
resonances and that their instabilities lead to the generation of the low
repetition rate frequency combs.",1707.04433v1
2017-12-06,Hadronic resonance production with ALICE at the LHC,"We present recent results on short-lived hadronic resonances obtained by the
ALICE experiment in pp, p-Pb and Pb-Pb collisions at LHC energies, including
the most recent measurements of $\Lambda(1520)$ and $\Xi(1530)^{0}$ resonances.",1712.02123v1
2017-12-11,Controlled phase quantum gate on off-resonant interaction of photon with three-level atom in single-mode resonator,"The optical scheme is proposed for realization of controlled phase quantum
gate based on the off-resonant interaction of photon with three-level atom in
single mode QED-cavity. Possible physical implementation of this scheme is
discussed.",1712.03765v2
2019-07-07,Resonances in the one dimensional Stark effect in the limit of small field,"We discuss the resonances of Hamiltonians with constant electric field in one
dimension in the limit of small field. These resonances occur near the real
axis, near zeros of the analytic continuation of a reflection coefficient for
potential scattering, and near the line arg z = -2\pi/3. We calculate their
asymptotics. In conclusion we make some remarks about the higher dimensional
problem.",1907.03333v1
2019-09-11,Hybrid meson interpretation of the exotic resonance π_{1}(1600),"The exotic J^{PC}= 1^{-+} resonance {\pi}_{1}(1600)is examined in the
framework of the Quark Model with Constituent Gluon (QMCG). We report the
possibility of interpreting that resonance as quark-antiquark-gluon hybrid
meson, with a masse = 1.65+0.05-0.04 GeV and a rho-pi decay width =
0.28+0.14-0.09 GeV.",1909.05180v1
2019-10-25,"A review of anomalous resonance, its associated cloaking, and superlensing","We review a selected history of anomalous resonance, cloaking due to
anomalous resonance, cloaking due to complementary media, and superlensing.",1910.13808v3
2020-02-25,Sinai billiard maps with Ruelle resonances,"We construct families of two-dimensional Sinai billiards whose transfer
operators have Ruelle resonances arbitrarily close to 1. Our method involves
taking a large enough cover of an initial billiard table, and relating the
transfer operator of the covering table to twisted transfer operators of the
initial table. We also study the distribution of these resonances which are
close to 1.",2002.11035v1
2020-04-16,Outgoing solutions via Gevrey-2 properties,"Gajic--Warnick have recently proposed a definition of scattering resonances
based on Gevrey-2 regularity at infinity and introduced a new class of
potentials for which resonances can be defined. We show that standard methods
based on complex scaling apply to a slightly larger class of potentials and
show existence of resonances in larger angles.",2004.07868v1
2012-05-31,The Resonant Transneptunian Populations,"The transneptunian objects (TNOs) trapped in mean-motion resonances with
Neptune were likely emplaced there during planet migration late in the
giant-planet formation process. We perform detailed modelling of the resonant
objects detected in the Canada-France Ecliptic Plane Survey (CFEPS) in order to
provide population estimates and, for some resonances, constrain the complex
internal orbital element distribution. Detection biases play a critical role
because phase relationships with Neptune make object discovery more likely at
certain longitudes. This paper discusses the 3:2, 5:2, 2:1, 3:1, 5:1, 4:3, 5:3,
7:3, 5:4, and 7:4 mean-motion resonances, all of which had CFEPS detections,
along with our upper limit on 1:1 Neptune Trojans (which is consistent with
their small population estimated elsewhere). For the plutinos (TNOs in the 3:2
resonance) we refine the orbital element distribution given in Kavelaars et al.
(2009) and show that steep H-magnitude distributions (N(H) proportional to
10aH, with a=0.8-0.9) are favoured in the range Hg=8-9, and confirm that this
resonance does not share the inclination distribution of the classical Kuiper
Belt. We give the first population estimate for the 5:2 resonance and find
that, to within the uncertainties, the population is equal to that of the 3:2
(13,000 TNOs with Hg < 9.16), whereas the 2:1 population is smaller by a factor
of 3-4 compared to the other two resonances. We also measure significant
populations inhabiting the 4:3, 5:3, 7:3, 5:4, 7:4, 3:1, and 5:1 resonances,
with Hg < 9.16 (D >100 km) populations in the thousands. We compare our
intrinsic population and orbital-element distributions with several published
models of resonant-TNO production; the most striking discrepancy is that
resonances beyond the 2:1 are in reality more heavily populated than in
published models.",1205.7065v1
2018-07-03,Centaurs potentially in retrograde co-orbit resonance with Saturn,"Aims. 2015 BZ509 is the first asteroid confirmed to be in retrograde co-orbit
resonance (or 1/-1 resonance) with the giant planets in the solar system. While
Saturn is the only giant planet whose Trojans are not discovered until now, we
identify some small bodies among Centaurs and Damocloids that are potentially
in 1/-1 resonance with Saturn in the present study. Methods. We integrate
numerically the motion of the 1000 clones (include the nominal orbit) of each
Centaur whose orbit has a semi-major axis between 9.3 au and 9.8 au and an
inclination i > 90 deg. To confirm and evaluate the 1/-1 resonant
configurations mentioned above, we introduce a useful one-degree integrable
approximation for planar 1/-1 resonance. Results. We identify four candidates
potentially in 1/-1 resonance with Saturn. The capture in this particular
resonant state during the 40000 yr integration timespan is very common for 2006
RJ2 (906/1000 clones), 2006 BZ8 (878/1000 clones), and 2017 SV13 (998/1000
clones), and it is less likely for 2012 YE8 (426/1000 clones). According to our
statistical results, 2006 RJ2 is the best candidate to be currently in a 1/-1
mean motion resonance with Saturn, and 2017 SV13 is another important potential
candidate. Moreover, 2012 YE8 and 2006 BZ8 are also Centaurs of interest but
their current and long-term 1/-1 resonant state with Saturn is less likely. The
proportions of the clones captured in the relative long-term stable co-orbit
resonance (over 10000 yr) are also given. Conclusions. Small bodies in
retrograde co-orbit resonance with giant planets may be more common than
previously expected. Identification of these potential mysterious minor bodies
encourages the search for such objects on a larger scale in our solar system.
The findings of this paper are also useful for understanding the origin and
dynamical evolution of the Centaurs and Damocloids on retrograde orbits.",1807.01330v1
2018-08-13,Two-Fluid Nonlinear Theory of Response of Tokamak Plasma to Resonant Magnetic Perturbation,"A comprehensive two-fluid nonlinear theory of magnetic reconnection driven at
a single, tearing-stable, rational surface embedded in an H-mode tokamak plasma
is presented. The surface is assumed to be resonant with one of the dominant
helical harmonics of an applied resonant magnetic perturbation (RMP). The
theory described in this paper is highly relevant to the problem of
understanding the physics of RMP-induced edge localized mode (ELM) suppression
in tokamak plasmas.",1808.04482v1
2019-01-28,Exponential decay of the resonance error in numerical homogenization via parabolic and elliptic cell problems,"This paper presents two new approaches for finding the homogenized
coefficients of multiscale elliptic PDEs. Standard approaches for computing the
homogenized coefficients suffer from the so-called resonance error, originating
from a mismatch between the true and the computational boundary conditions. Our
new methods, based on solutions of parabolic and elliptic cell-problems, result
in an exponential decay of the resonance error.",1901.09758v1
2019-02-10,Expansion of the resolvent in a Feshbach model,"In this paper we extend the results proved in (Carlone, R., Correggi, M.,
Finco, D., Teta, A.: A model for Feshbach Resonances arXiv:1901.08282
[math-ph]) about Feshbach resonances in a multichannel Hamiltonian
$\mathcal{H}$, proving a low energy expansion of the resolvent
$(\mathcal{H}-k^{2})^{-1}$ as $k\to 0$ in the resonant case.",1902.03626v2
2020-03-16,Resonances and viscosity limit for the Wigner-von Neumann type Hamiltonian,"The resonances for the Wigner-von Neumann type Hamiltonian are defined by the
periodic complex distortion in the Fourier space. Also, following Zworski, we
characterize resonances as the limit points of discrete eigenvalues of the
Hamiltonian with a quadratic complex absorbing potential in the viscosity type
limit.",2003.07001v2
2020-06-03,Certain Inverse Resonance Uniqueness on the Line with Super-Exponentially Decaying Potential,"In the paper, we study the inverse problem with the resonant data of fast
decaying potential $V$. We review Froese' construction of the Born's
approximation and Neumann series to analyze the growth of scattering
determinant. Assuming all the the resonances are given, we deduce the certain
inverse uniqueness on $V$ from the Nevanlinna type of representation theorem.",2006.02468v1
2020-06-22,Dynamics of resonances for 0th order pseudodifferential operators,"We study the dynamics of resonances of analytic perturbations of 0th order
pseudodifferential operators $P(s)$. In particular, we prove a Fermi golden
rule for resonances of $P(s)$ at embedded eigenvalues of $P=P(0)$. We also
study the dynamics of eigenvalues of $P(t)=P+it\Delta$ as the eigenvalues
converge to simple eigenvalues of $P$. The 0th order pseudodifferential
operators we consider satisfy natural dynamical assumptions and are used as
microlocal models of internal waves.",2006.11951v1
2020-11-03,Deconfinement and Hadron Resonance Gas for Heavy Quarks,"I discuss the deconfinement transition in 2+1 flavor QCD in terms of Polyakov
loops as well as the hadron resonance gas for hadrons containing static quarks
and charm quarks.",2011.01466v2
2021-08-03,Synchronizing two superconducting qubits through a dissipating resonator,"A system consisting of two qubits and a resonator is considered in the
presence of different sources of noise, bringing to light the possibility for
making the two qubits evolve in a synchronized way. A direct qubit-qubit
interaction turns out to be a crucial ingredient as well as dissipation
processes involving the resonator. The detrimental role of local dephasing of
the qubits is also taken into account.",2108.01323v1
2021-09-06,Laplace-like resonances with tidal effects,"We generalize the Laplace resonance among three satellites, S1, S2 , and S3,
by considering different ratios of the mean-longitude variations. These
resonances, which we call Laplace-like, are classified as first order in the
cases of the 2:1&2:1, 3:2&3:2, and 2:1&3:2 resonances, second order in the case
of the 3:1&3:1 resonance, and mixed order in the case of the 2:1&3:1 resonance.
We consider a model that includes the gravitational interaction with the
central body together with the effect due to its oblateness, the mutual
gravitational influence of the satellites S1, S2, and S3 and the secular
gravitational effect of a fourth satellite S 4 , which plays the role of
Callisto in the Galilean system. In addition, we consider the dissipative
effect due to the tidal torque between the inner satellite and the central
body. We investigate these Laplace-like resonances by studying different
aspects: (i) we study the survival of the resonances when the dissipation is
included, taking two different expressions for the dissipative effect in the
case of a fast- or a slowly rotating central body, (ii) we investigate the
behavior of the Laplace-like resonances when some parameters are varied,
specifically, the oblateness coefficient, the semimajor axes, and the
eccentricities of the satellites, (iii) we analyze the linear stability of
first-order resonances for different values of the parameters, and (iv) we also
include the full gravitational interaction with S 4 to analyze its possible
capture into resonance. The results show a marked difference between first-,
second-, and mixed-order resonances, which might find applications when the
evolutionary history of the satellites in the Solar System are studied, and
also in possible actual configurations of extrasolar planetary systems.",2109.02694v1
2021-10-05,Spin-1 resonances,"Spin-1 resonances are naturally present in composite Higgs frameworks. We
first review a model independent approach to parametrize a single additional
heavy triplet and then we consider more realistic models arising in composite
Higgs scenarios where a larger number of spin-1 resonances is expected. In
these cases, finite width and interference effects can heavily affect the
bounds extracted from the data.",2110.01907v1
2022-05-09,Anti-resonances and sharp analysis of Maryland localization for all parameters,"We develop the technique to prove localization through the analysis of
eigenfunctions in presence of both exponential frequency resonances and
exponential phase barriers (anti-resonances) and use it to prove localization
for the Maryland model for all parameters.",2205.04021v1
2022-06-13,Inverse problems for Jacobi operators with finitely supported perturbations,"We solve the inverse problem for Jacobi operators on the half lattice with
finitely supported perturbations, in particular, in terms of resonances. Our
proof is based on the results for the inverse eigenvalue problem for specific
finite Jacobi matrices and theory of polynomials. We determine forbidden
domains for resonances and maximal possible multiplicities of real and complex
resonances.",2206.06242v1
2022-10-06,Hadronic resonance production with ALICE at the LHC,"We present recent results on short-lived hadronic resonances obtained by the
ALICE experiment at LHC energies. Results include system-size and
collision-energy evolution of transverse momentum spectra, yields and ratios of
resonance yields to those of longer lived particles, and nuclear modification
factors. The results are compared with model predictions and measurements at
lower energies.",2210.02929v1
2023-02-10,Identifying Resonant Poles by Visual Inspection of Pole-Zero Plots,"We derive the s- and z-plane pole regions for continuous-time and
discrete-time LTI systems to yield resonance. In this way, resonance can be
identified by visual inspection of the pole-zero plot, without the need for
calculations.",2302.05532v1
2023-03-16,Uniqueness of weak solutions to the limit resonant equation of 3D rotating Navier-Stokes equations,"The limit resonant equation of the 3D rotating Navier-Stokes equations is
obtained by taking large rotation limit. This equation has a nonlinear term
with restricted interactions between Fourier modes, and thus it enjoys better
regularity estimates than those of the classical 3D Navier-Stokes equations.
Such estimates enable us to prove uniqueness of weak solutions to the limit
resonant equation.",2303.09179v1
2023-05-10,"Resonances of the d'Alembertian on the Anti-de Sitter space $\mathop{\rm{SO_e}}(2,2)/\mathop{\rm{SO_e}}(2,1)$","We consider the action of the d'Alembertian on the functions on the
pseudo-Riemannian 3-dimensional Anti-de Sitter space. We determine the
resonances of this operator. With each resonance one can associate a residue
representation. We give an explicit description of these representations via
Langlands parameters.",2305.05922v1
2023-06-04,Counting Pollicott--Ruelle resonances for Axiom A flows,"In this paper, we count the number of Pollicott--Ruelle resonances for open
hyperbolic systems and Axiom A flows. In particular, we prove polynomial upper
bounds and sublinear lower bounds on the number of resonances with modulus less
than $r$ in strips for open hyperbolic systems and Axiom A flows with a
transversality condition.",2306.02297v2
2023-07-04,Photonic bound states in the continuum governed by heating,"A photonic crystal microcavity with the liquid crystal resonant layer tunable
by heating has been implemented. The multiple vanishing resonant lines
corresponding to optical bound states in the continuum are observed. The abrupt
behaviour of the resonant linewidth near the vanishing point can be used for
temperature sensing.",2307.01628v1
2023-07-18,Proton 0.01 MeV resonance width and low-energy $S$-factor of p+10B fusion,"{\bf{Purpose}:} In this paper, the proton resonance width of the
near-threshold resonance is calculated using two different approaches. The
values of the proton width are used to calculate the low-energy $S$-factor. \\
{\bf{Method:}} First, the proton resonance width is estimated using the mirror
symmetry of the resonance $ {}^{11}{\rm C}(E_{x}=8.70\, {\rm
MeV};\,\frac{5}{2}^{+})$ and the mirror bound state ${}^{11}{\rm
B}(E_{x}=9.272\, {\rm MeV};\,\frac{5}{2}^{+})$. In the second approach, this
width is estimated using the $R$-matrix definition of the observable resonance
width, which is expressed in terms of the $p-{}^{10}{\rm B}$ resonant wave
function calculated in the potential approach and the spectroscopic factor. \\
{\bf{Results}:} Depending on the method chosen, the calculated proton resonance
width varies from $\,1.03 \times 10^{-19}\,$MeV to $\,2.96 \times
10^{-19}\,$MeV. The role of the near-threshold resonance is determined using
fitting of two low-energy $S$-factors from direct measurements [C. Angulo {\it
et al.}, Z. Phys. A {\bf 345}, 333 (1993)] and from the indirect Trojan horse
method (THM) [ A. Cvetinovi\'c {\it et al.}, Phys. Rev. C {\bf 97}, 065801
(2018)]. Within the framework of the $R$-matrix method using the determined
proton resonance widths and the modified THM parameters for six low-lying
resonances, the low-energy $S$-factors were calculated and compared with the
corresponding experimental $S$-factors. The closest agreement with the data is
achieved with the proton resonance widths $1.0 \times 10^{-19}$ MeV when
fitting the $S$-factor from the THM indirect measurements, and $\,1.68 \times
10^{-19}\,$ MeV and $\,2.5 \times 10^{-19}\,$ MeV when fitting the $S$-factor
from [Angulo {\it et al}, Z. Phys. A {\bf 345}, 333 (1993)].\",2307.08963v2
2023-07-29,Resonant Ultrasound Spectroscopy: Asymptotic Behavior of Resonant Frequencies,"Resonance ultrasound spectroscopy (RUS) is a non-destructive technique used
to assess materials' elastic and anelastic properties. It involves measuring
the frequencies of free vibrations in a carefully prepared sample to extract
material properties. In this paper, we investigate the asymptotic behavior of
eigenfrequencies. Our primary focus is on analyzing the asymptotic behavior of
eigenfrequencies, aiming to understand their rate of growth and convergence. We
also make observations regarding the impact of elastic constants on
eigenfrequencies.",2307.16095v1
2023-08-29,A remark on the onset of resonance overlap,"Chirikov's celebrated criterion of resonance overlap has been widely used in
celestial mechanics and Hamiltonian dynamics to detect global instability, but
is rarely rigourous. We introduce two simple Hamiltonian systems, each
depending on two parameters measuring respectively the distance to resonance
overlap and non-integrability. Within some thin region of the parameter plane,
classical perturbation theory shows the existence of global instability and
symbolic dynamics, thus illustrating Chirikov's criterion.",2308.15222v1
2023-11-28,The structure of the wave operators in four dimensions in the presence of resonances,"We show that the wave operators for Schr\""{o}dinger scattering in
$\mathbb{R}^4$ have a particular form which depends on the existence of
resonances. As a consequence of this form, we determine the contribution of
resonances to the index of the wave operator.",2311.16438v1
2023-11-28,The Hoyle and associated excited states from the viewpoint of pocket resonances in alpha + 8Be reactions,"We examine the production of the Hoyle and associated excited states from the
viewpoint of pocket resonances in the reaction of an $\alpha$-particle on a
ground state prolate $^8$Be nucleus within the optical model coupled-channel
framework. The predicted reaction cross sections, as a function of the
center-of-mass energy $E_{\rm cm}$, show prominent resonances, including the
Hoyle resonance. The positions and widths of these resonances are sensitive to
the target deformation ($\beta_2$ parameter) and the parity of the nuclear
surface potential $-$ deeper for the even-parity $L$ partial waves relative to
those for the odd-parity $L$ partial waves at the surface region because of the
Bose-Einstein exchange of the $\alpha$-bosons. Decomposing the reaction cross
sections to different partial waves, we find that the resonance energies and
widths reasonably agree with the available experimental data and previous
hyperspherical calculations for the $0_2^+$ (Hoyle state), $0_3^+$, $1_1^-$ and
$3_1^-$ states of $^{12}$C, except for the narrow theoretical width of the
$2_2^+$ state. Analyzing the wavefunctions and the resonance widths, we
identify the narrow and sharp $0_2^+$, $3_1^-$ and $2_2^+$ resonances as pocket
resonances -- resonances which occur below the potential barrier, while the
broad $0_3^+$ and $1_1^-$ resonances as above-the-barrier resonances. For
astrophysical applications, we also evaluate the astrophysical $S(E_{\rm
cm})$-factor for $E_{\rm cm}$ $<$ 1.0 MeV, for the fusion of $\alpha$+$^8$Be
into the $^{12}$C$(2^+)$ state based on our estimated $s$-wave $\alpha$+$^8$Be
reaction cross section and the associated $\gamma$- and $\alpha$-decay widths
for the decay of $^{12}$C excited states in the potential pocket.",2311.16837v1
2023-11-30,Results of numeric integrations of orbits of (5026) Martes and 2005 WW113 asteroid pair,"The orbital dynamic of very young asteroid pair (5026) Martes and 2005 WW113
is studied by numerical integrations. We discover strong resonant perturbations
of the larger member of pair (5026) Martes by the mean motion resonance 3:11
with Earth. The unbounded secondary (2005 WW113) moved far from the resonance
and is not perturbed.",2311.18439v1
2024-01-19,Many-body Stark resonances by the complex absorbing potential method,"The resonances of many-body Stark Hamiltonians are characterized by the
complex absorbing potential method. Namely, the resonances are shown to be the
limit points of complex discrete eigenvalues of many-body Stark Hamiltonians
with quadratic complex potential when the coefficient of the complex potential
tends to zero.",2401.10562v1
2024-02-09,Tidal resonances for fuzzballs,"We study the gravitational tidal response of D1D5, Top Star and (1,0,n)
strata horizonless geometries. We find that the tidal interactions in fuzzball
geometries, unlike in the case of black holes, exhibits a sequence of resonant
peaks associated to the existence of metastable bound states. The spectrum of
resonant frequencies is computed by semi-analytical and numerical methods.",2402.06621v1
2024-03-26,Average amplitude and phase detuning near driven 3rd integer resonance,"For resonant slow extraction of accelerated particle beams from synchrotrons,
a 3rd order resonance driven by sextupole magnets is commonly used. This note
reviews the non-linear particle dynamics under these conditions as described by
the Kobayashi Hamiltonian, focussing on the amplitude and phase dependent
detuning. Using the Kobayashi Hamiltonian as the invariant, an expression for
the action and the average detuning as a function of the Hamiltonian is derived
and compared to numerically obtained results.",2403.17629v1
2001-07-23,"Electronic structure study of double perovskites $A_{2}$FeReO$_{6}$ (A=Ba,Sr,Ca) and Sr$_{2}M$MoO$_{6}$ (M=Cr,Mn,Fe,Co) by LSDA and LSDA+U","We have implemented a systematic LSDA and LSDA+U study of the double
perovskites $A_{2}$FeReO$_{6}$ (A=Ba,Sr,Ca) and Sr$_{2}$$M$MoO$_{6}$
(M=Cr,Mn,Fe,Co) for understanding of their intriguing electronic and magnetic
properties. The results suggest a ferrimagnetic (FiM) and half-metallic (HM)
state of $A_{2}$FeReO$_{6}$ (A=Ba,Sr) due to a pdd-$\pi$ coupling between the
down-spin Re$^{5+}$/Fe$^{3+}$ $t_{2g}$ orbitals via the intermediate O
$2p_{\pi}$ ones, also a very similar FiM and HM state of Sr$_{2}$FeMoO$_{6}$.
In contrast, a decreasing Fe $t_{2g}$ component at Fermi level ($E_{F}$) in the
distorted Ca$_{2}$FeReO$_{6}$ partly accounts for its nonmetallic behavior,
while a finite $pdd$-$\sigma$ coupling between the down-spin
Re$^{5+}$/Fe$^{3+}$ $e_{g}$ orbitals being present at $E_{F}$ serves to
stabilize its FiM state. For Sr$_{2}$CrMoO$_{6}$ compared with
Sr$_{2}$FeMoO$_{6}$, the coupling between the down-spin Mo$^{5+}$/Cr$^{3+}$
$t_{2g}$ orbitals decreases as a noticeable shift up of the Cr$^{3+}$ 3d
levels, which is likely responsible for the decreasing $T_{C}$ value and weak
conductivity. Moreover, the calculated level distributions indicate a
Mn$^{2+}$(Co$^{2+}$)/Mo$^{6+}$ ionic state in Sr$_{2}$MnMoO$_{6}$
(Sr$_{2}$CoMoO$_{6}$), in terms of which their antiferromagnetic insulating
ground state can be interpreted. While orbital population analyses show that
owing to strong intrinsic pd covalence effects, Sr$_{2}M$MoO$_{6}$
(M=Cr,Mn,Fe,Co) have nearly the same valence state combinations, as accounts
for the similar M-independent spectral features observed in them.",0107462v1
2002-01-17,55Mn NMR in Mn12 acetate: Hyperfine interaction and magnetic relaxation of cluster,"The 55Mn NMR in oriented powder Mn12Ac has been investigated at 1.4-2.0 K in
zero field and with external fields along the c-axis. Three kinds of 55Mn NMR
composed of five-fold quadrupole-split lines for I=5/2 nuclei have been
interpreted to arise from Mn4+ ion, and two crystallographically-inequivalent
Mn3+ ions, respectively. It is found that the isotropic hyperfine field in the
Mn4+ ion with 3d3 configuration indicates a large amount of reduction (26%) as
compared with the theoretical evaluation. In the analysis for the hyperfine
field of Mn3+ ions with 3d4 configuration, we have taken into account of the
anisotropic dipolar contribution in addition to the Fermi-contact term in order
to explain two kinds of 55Mn NMR frequencies in Mn3+ ions in inequivalent
sites. By using the hyperfine coupling constants of twelve manganese ions in
Mn12Ac, the total hyperfine interaction of the ferrimagnetic ground state of
S=10 has been determined to amount to 0.3 cm-1 in magnitude at most, the
magnitude of which corresponds to the nuclear hyperfine field he(0.32 kG seen
by Mn12 cluster spin. The relaxation of the cluster magnetization was
investigated by observing the recovery of the 55Mn spin-echo intensity in the
fields of 0.20-1.90 T along the c-axis at 2.0 K. It was found that the
magnetization of the cluster exhibits the (t-recovery in the short time regime.
The relaxation time decreases with increasing external field following
significant dips at every 0.45 T. This is interpreted to be due to the effects
of thermally-assisted quantum tunneling between the spin states at magnetic
level crossings.",0201297v1
2004-07-01,Spin structure and magnetic phase transitions in TbBaCo2O5.5,"Spin ordering in TbBaCo2O5.5 and its temperature transformation is studied.
Polymorphism due to the oxygen ordering with the average content close to 5.5
is investigated. One of ceramic samples (I), in addition to the main phase ap x
2ap x 2ap, Pmmm, (Z=2), contained about 25% of the phase ap x ap x 2ap, Pmmm,
(Z=1), with statistical distribution of oxygen over the apical sites, where ap
is parameter of perovskite cell. The other sample (II) contained only a main
phase with well defined octahedral and pyramidal sublattices. Treatment of
neutron diffraction patterns of the sample I itself gives a sophisticated spin
structure. Knowing the structure of sample II, one can chose only proper
magnetic lines, which give exactly the same results as for sample II. Above the
Neel temperature TN ~ 290K, there is a structural transition to the phase 2ap x
2ap x 2ap, Pmma. At TN, the spins order with the wave vector k19 = 0 (Phase 1).
At T1 ~ 255K, a magnetic transition takes place to the phase 2 with k22 = b3/2.
At T2 ~ 170K, the crystal structure changes to 2ap x 2ap x 4ap, Pcca (Z=4). The
wave vector of the spin structure becomes again k19 = 0 (Phase 3). The basis
functions of irreducible representations of the group Gk have been found. Using
results of this analysis, the magnetic structure in all phases is determined.
The spins are always parallel to the x axis, and the difference is in the
values and mutual orientation of the moments in the ordered non-equivalent
pyramidal or octahedral positions. Spontaneous moment at T = 260 K is due to
ferrimagnetic ordering of the moments in pyramidal sites.
(Dzyaloshinskii-Moriya canting is forbidden by symmetry.) The moment values
together with the ligand displacements are used to analyze the picture of
spin-state/orbital ordering in each phase.",0407010v3
2007-04-06,Quantum and Classical Spins on the Spatially Distorted Kagome Lattice: Applications to Volborthite,"In Volborthite, spin-1/2 moments form a distorted Kagom\'e lattice, of corner
sharing isosceles triangles with exchange constants $J$ on two bonds and $J'$
on the third bond. We study the properties of such spin systems, and show that
despite the distortion, the lattice retains a great deal of frustration.
Although sub-extensive, the classical ground state degeneracy remains very
large, growing exponentially with the system perimeter. We consider degeneracy
lifting by thermal and quantum fluctuations. To linear (spin wave) order, the
degeneracy is found to stay intact. Two complementary approaches are therefore
introduced, appropriate to low and high temperatures, which point to the same
ordered pattern. In the low temperature limit, an effective chirality
Hamiltonian is derived from non-linear spin waves which predicts a transition
on increasing $J'/J$, from $\sqrt 3\times \sqrt 3$ type order to a new
ferrimagnetic {\em striped chirality} order with a doubled unit cell. This is
confirmed by a large-N approximation on the O($n$) model on this lattice. While
the saddle point solution produces a line degeneracy, $O(1/n)$ corrections
select the non-trivial wavevector of the striped chirality state. The quantum
limit of spin 1/2 on this lattice is studied via exact small system
diagonalization and compare well with experimental results at intermediate
temperatures. We suggest that the very low temperature spin frozen state seen
in NMR experiments may be related to the disconnected nature of classical
ground states on this lattice, which leads to a prediction for NMR line shapes.",0704.0933v2
2012-12-02,Tunable interplay between 3d and 4f electrons in Co-doped iron pnictides,"We study the interplay of 3d and 4f electrons in the iron pnictides
CeFe$_{1-x}$Co$_x$AsO and GdFe$_{1-y}$Co$_y$AsO, which correspond to two very
different cases of $4f$-magnetic moment. Both CeFeAsO and GdFeAsO undergo a
spin-density-wave (SDW) transition associated with Fe 3d electrons at high
temperatures, which is rapidly suppressed by Fe/Co substitution.
Superconductivity appears in a narrow doping range: $0.05 < x < 0.2$ for
CeFe$_{1-x}$Co$_x$AsO and $0.05 < y < 0.25$ for GdFe$_{1-y}$Co$_y$AsO, showing
a maximum transition temperature $T_\textup{sc}$ of about 13.5 K for Ce and 19
K for Gd. In both compounds, the $4f$-electrons form an antiferromagnetic (AFM)
order at low temperatures over the entire doping range and Co 3d electrons are
ferromagnetically ordered on the Co-rich side; the Curie temperature reaches
$T_\textup{C}^\textup{Co} \approx$ 75 K at $x = 1$ and $y = 1$. In the
Ce-compounds, the N\'{e}el temperature $T_\textup{N}^\textup{Ce}$ increases
upon suppressing the SDW transition of Fe and then remains nearly unchanged
with further increasing Co concentration up to $x \simeq 0.8$
($T_\textup{N}^\textup{Ce}\approx$ 4 K). Furthermore, evidence of Co-induced
polarization on Ce-moments is observed on the Co-rich side. In the
Gd-compounds, the two magnetic species of Gd and Co are coupled
antiferromagnetically to give rise to ferrimagnetic behavior in the magnetic
susceptibility on the Co-rich side. For $0.7 \leq y < 1.0$, the system
undergoes a possible magnetic reorientation below the N\'{e}el temperature of
Gd ($T_\textup{N}^\textup{Gd}$). Our results suggest that the effects of both
electron hybridizations and magnetic exchange coupling between the 3d-4f
electrons give rise to a rich phase diagram in the rare-earth iron pnictides.",1212.0221v2
2013-04-18,Alloying effect on the ideal tensile strength of ferromagnetic and paramagnetic bcc iron,"Using \emph{ab initio} alloy theory formulated within the exact muffin-tin
orbitals theory in combination with the coherent potential approximation, we
investigate the ideal tensile strength (ITS) in the $[001]$ direction of bcc
ferro-/ferrimagnetic (FFM) and paramagnetic (PM) Fe$_{1-x}M_{x}$ ($M=$ Al, V,
Cr, Mn, Co, or Ni) random alloys. The ITS of ferromagnetic (FM) Fe is
calculated to be $12.6$\,GPa, in agreement with available data, while the PM
phase turns out to posses a significantly lower value of $0.7\,$GPa. Alloyed to
the FM matrix, we predict that V, Cr, and Co increase the ITS of Fe, while Al
and Ni decrease it. Manganese yields a weak non-monotonic alloying behavior. In
comparison to FM Fe, the alloying effect of Al and Co to PM Fe is reversed and
the relative magnitude of the ITS can be altered more strongly for any of the
solutes. All considered binaries are intrinsically brittle and fail by cleavage
of the $(001)$ planes under uniaxial tensile loading in both magnetic phases.
We show that the previously established ITS model based on structural energy
differences proves successful in the PM Fe-alloys but is of limited use in the
case of the FFM Fe-based alloys. The different performance is attributed to the
specific interplay between magnetism and volume change in response to uniaxial
tension. We establish a strong correlation between the compositional effect on
the ITS and the one on the shear elastic constant $C'$ for the PM alloys and
briefly discuss the relation between hardenability and the ITS.",1304.5129v2
2014-01-14,"Structural ground states of ($A,A'$)Cr$_2$O$_4$($A$=Mg, Zn; $A^{\prime}$ = Co, Cu) spinel solid solutions: Spin-Jahn-Teller and Jahn-Teller effects","We examine the effect of small amounts of magnetic substituents in the $A$
sites of the frustrated spinels MgCr$_2$O$_4$ and ZnCr$_2$O$_4$. Specifically
we look for the effects of spin and lattice disorder on structural changes
accompanying magnetic ordering in these compounds. Substitution of Co$^{2+}$ on
the non-magnetic Zn$^{2+}$ site in Zn$_{1-x}$Co$_{x}$Cr$_2$O$_4$ where
0\,$<$\,$x$\,$\leq$\,0.2 completely suppresses the spin-Jahn-Teller distortion
of ZnCr$_2$O$_4$ although these systems remain frustrated, and magnetic
ordering occurs at very low temperatures of $T$\,$<$\,20\,K. On the other hand,
the substitution of Jahn-Teller active Cu$^{2+}$ for Mg$^{2+}$ and Zn$^{2+}$ in
Mg$_{1-x}$Cu$_{x}$Cr$_2$O$_4$ and Zn$_{1-x}$Cu$_{x}$Cr$_2$O$_4$ where
0\,$<$\,$x$\,$\leq$\,0.2 induce Jahn-Teller ordering at temperatures well above
the N\'eel temperatures of these solid solutions, and yet spin interactions
remain frustrated with long-range magnetic ordering occurring below 20\,K
without any further lattice distortion. The Jahn-Teller distorted solid
solutions Mg$_{1-x}$Cu$_{x}$Cr$_2$O$_4$ and Zn$_{1-x}$Cu$_{x}$Cr$_2$O$_4$ adopt
the orthorhombic $Fddd$ structure of ferrimagnetic CuCr$_2$O$_4$. Total neutron
scattering studies of Zn$_{1-x}$Cu$_{x}$Cr$_2$O$_4$ suggest that there are
local $A$O$_4$ distortions in these Cu$^{2+}$-containing solid solutions at
room temperature and that these distortions become cooperative when average
structure distortions occur. Magnetism evolves from compensated
antiferromagnetism in MgCr$_2$O$_4$ and ZnCr$_2$O$_4$ to uncompensated
antiferromagnetism with substitution of magnetic cations on the non-magnetic
cation sites of these frustrated compounds.",1401.3081v1
2015-04-01,"First-principles study of the inversion thermodynamics and electronic structure of Fe$M_2X_4$ (thio)spinels ($M=$ Cr, Mn, Co, Ni; $X=$ O, S)","Fe$M_2X_4$ spinels, where $M$ is a transition metal and $X$ is oxygen or
sulfur, are candidate materials for spin filters, one of the key devices in
spintronics. We present here a computational study of the inversion
thermodynamics and the electronic structure of these (thio)spinels for $M=$ Cr,
Mn, Co, Ni, using calculations based on the density functional theory with
on-site Hubbard corrections (DFT+$U$). The analysis of the configurational free
energies shows that different behaviour is expected for the equilibrium cation
distributions in these structures: FeCr$_2X_4$ and FeMn$_2$S$_4$ are fully
normal, FeNi$_2X_4$ and FeCo$_2$S$_4$ are intermediate, and FeCo$_2$O$_4$ and
FeMn$_2$O$_4$ are fully inverted. We have analyzed the role played by the size
of the ions and by the crystal field stabilization effects in determining the
equilibrium inversion degree. We also discuss how the electronic and magnetic
structure of these spinels is modified by the degree of inversion, assuming
that this could be varied from the equilibrium value. We have obtained
electronic densities of states for the completely normal and completely inverse
cation distribution of each compound. FeCr$_2X_4$, FeMn$_2X_4$, FeCo$_2$O$_4$
and FeNi$_2$O$_4$ are half-metals in the ferrimagnetic state when Fe is in
tetrahedral positions. When $M$ is filling the tetrahedral positions, the
Cr-containing compounds and FeMn$_2$O$_4$ are half-metallic systems, while the
Co and Ni spinels are insulators. The Co and Ni sulfide counterparts are
metallic for any inversion degree together with the inverse FeMn$_2$S$_4$. Our
calculations suggest that the spin filtering properties of the Fe$M_2X_4$
(thio)spinels could be modified via the control of the cation distribution
through variations in the synthesis conditions.",1504.00268v2
2016-09-15,Self-consistent mapping: Effect of local environment on formation of magnetic moment in alpha-FeSi2,"We suggest here the method of the mapping of DFT calculations on the
multiorbital model in a following way: the parameters of the formulated
multiorbital model should be determined from the requirement that the
self-consistent charge and spin densities found from the ab initio and model
calculations have to be as close to each other as possible. The analysis of the
model allows for detailed understanding of the role played by different
parameters of the model in the physics of interest. As an example of the
approach we present the study of the effect of silicon atoms substitution by
the iron atoms and vice versa on the magnetic properties in the iron silicide
alpha-FeSi2. The DFT+GGA calculations are mapped to the model with intraatomic
Coulomb and exchange interactions, hoppings to nearest and next nearest atoms
and exchange of the delocalized electrons between iron atoms; the magnetic
moments on atoms and charge densities of the material are found
self-consistently within the Hartree-Fock approximation. We find that while the
stoichiometric alpha-FeSi2 is nonmagnetic, the substitutions generate different
magnetic structures. For example, the substitution of three Si atoms by the Fe
atoms results in the ferrimagnetic structure whereas the substitution of four
Si atoms by Fe atoms gives rise to either the nonmagnetic or the ferromagnetic
state depending on the type of local enviroment of the substitutional Fe atoms.
Besides, contrary to the commonly accepted statement that the destruction of
the magnetic moment is controlled only by the number of Fe-Si nearest
neighbors, we find that actually it is controlled by the Fe-Fe
next-nearest-neighbors. This finding led us to the counterintuitive conclusion:
an increase of Si concentration in Fe1-xSi2+x ordered alloys may lead to a
ferromagnetism. This conclusion is confirmed by the calculation within
GGA-to-DFT.",1609.04624v1
2017-08-06,Thermally Driven Long Range Magnon Spin Currents in Yttrium Iron Garnet due to Intrinsic Spin Seebeck Effect,"The longitudinal spin Seebeck effect refers to the generation of a spin
current when heat flows across a normal metal/magnetic insulator interface.
Until recently, most explanations of the spin Seebeck effect use the
interfacial temperature difference as the conversion mechanism between heat and
spin fluxes. However, recent theoretical and experimental works claim that a
magnon spin current is generated in the bulk of a magnetic insulator even in
the absence of an interface. This is the so-called intrinsic spin Seebeck
effect. Here, by utilizing a non-local spin Seebeck geometry, we provide
additional evidence that the total magnon spin current in the ferrimagnetic
insulator yttrium iron garnet (YIG) actually contains two distinct terms: one
proportional to the gradient in the magnon chemical potential (pure magnon spin
diffusion), and a second proportional to the gradient in magnon temperature
($\nabla T_m$). We observe two characteristic decay lengths for magnon spin
currents in YIG with distinct temperature dependences: a temperature
independent decay length of ~ 10 ${\mu}$m consistent with earlier measurements
of pure ($\nabla T_m = 0$) magnon spin diffusion, and a longer decay length
ranging from about 20 ${\mu}$m around 250 K and exceeding 80 ${\mu}$m at 10 K.
The coupled spin-heat transport processes are modeled using a finite element
method revealing that the longer range magnon spin current is attributable to
the intrinsic spin Seebeck effect ($\nabla T_m \neq 0$), whose length scale
increases at lower temperatures in agreement with our experimental data.",1708.01941v3
2018-02-12,"Superconducting transition temperatures in the electronic and magnetic phase diagrams of Sr2VFeAsO3-delta, a superconductor","We elucidate the magnetic phases and superconducting transition temperatures
(Tc) in Sr2VFeAsO3-delta (21113V), an iron-based superconductor with a
thick-blocking layer fabricated from a perovskite-related transition metal
oxide. At low temperatures (T < 37.1 K), 21113V exhibited a superconducting
phase in the range 0.031 =< delta =< 0.145 and an antiferromagnetic (AFM) iron
sublattice in the range 0.267 =< delta =< 0.664. Mixed-valent vanadium
exhibited a dominant AFM phase in 0.031 =< delta =< 0.088, and a partial
ferrimagnetic (Ferri.) phase in the range 0.124 =< delta =< 0.664. The Ferri.
phase was the most dominant at a delta value of 0.267, showing an AFM phase of
Fe at T < 20 K. Increasing the spontaneous magnetic moments reduced the
magnetic shielding volume fraction due to the superconducting phase. This
result was attributed to the magnetic phase of vanadium, which dominates the
superconductivity of Fe in 21113V. The Tc-delta curve showed two maxima. The
smaller and larger of Tc maxima occurred at delta = 0.073 and delta = 0.145,
respectively; the latter resides on the phase boundary between AFM and the
partial Ferri. phases of vanadium. 21113V is a useful platform for verifing new
mechanisms of Tc enhancement in iron-based superconductors.",1802.03907v2
2018-04-16,Phase diagram description of the CaCu$_3$Fe$_4$O$_{12}$ double perovskite,"CaCu$_3$Fe$_4$O$_{12}$ exhibits a temperature-induced transition from a
ferrimagnetic-insulating phase, in which Fe appears charge disproportionated,
as Fe$^{3+}$ and Fe$^{5+}$, to a paramagnetic-metallic phase at temperatures
above 210 K, with Fe$^{4+}$ present. To describe it, we propose a microscopic
effective model with two interpenetrating sublattices of Fe$^{(4-\delta)+}$ and
Fe$^{(4+\delta)+}$, respectively, being $\delta$ the Fe-charge
disproportionation. We include all $3d$-Fe orbitals: $t_{2g}$ localized
orbitals, with spin 3/2 and magnetically coupled, plus two degenerate itinerant
$e_g$ orbitals with local and nearest-neighbor (NN) electron correlations, and
hopping between NN $e_g$ orbitals of the same symmetry. Allub and Alascio
previously proposed a model to describe the phase transition in
LaCu$_3$Fe$_4$O$_{12}$ from a paramagnetic-metal to an
antiferromagnetic-insulator, induced by temperature or pressure, involving
charge transfer between Fe and Cu ions, in contrast to Fe-charge
disproportionation. With the model proposed for CaCu$_3$Fe$_4$O$_{12}$,
modified to account for this difference between the two compounds, the density
of states of the itinerant Fe orbitals was obtained, using Green's functions
methods. The phase diagram for CaCu$_3$Fe$_4$O$_{12}$ was calculated, including
phases exhibiting Fe-charge disproportionation, where the two eg orbitals in
each site are symmetrically occupied, as well as novel phases exhibiting local
orbital selectivity/asymmetric occupation of $e_g$ orbitals. Both kinds of
phases may exhibit paramagnetism and ferromagnetism. We determined the model
parameters which best describe the phase transition observed in
CaCu$_3$Fe$_4$O$_{12}$, and found other phases at different parameter ranges,
which might be relevant for other compounds of the ACu$_3$Fe$_4$O$_{12}$
family, which present both types of transitions.",1804.05726v1
2014-03-02,Magnons and a two-component spin gap in FeV2O4,"The spinel vanadates have become a model family for exploring orbital order
on the frustrated pyrochlore lattice, and recent debate has focused on the
symmetry of local crystal fields at the cation sites. Here, we present neutron
scattering measurements of the magnetic excitation spectrum in
$\mathrm{FeV_2O_4}$, a recent example of a ferrimagnetic spinel vanadate which
is available in single crystal form. We report the existence of two emergent
magnon modes at low temperatures, which draw strong parallels with the closely
related material, $\mathrm{MnV_2O_4}$. We were able to reproduce the essential
elements of both the magnetic ordering pattern and the dispersion of the
inelastic modes with semi- classical spin wave calculations, using a minimal
model that implies a sizeable single-ion anisotropy on the vanadium sublattice.
Taking into account the direction of ordered spins, we associate this
anisotropy with the large trigonal distortion of $\mathrm{VO_6}$ octahedra,
previously observed via neutron powder diffraction measurements. We further
report on the spin gap, which is an order-of-magnitude larger than that
observed in $\mathrm{MnV_2O_4}$. By looking at the overall temperature
dependence, we were able to show that the gap magnitude is largely associated
with the ferro-orbital order known to exist on the iron sublattice, but the
contribution to the gap from the vanadium sublattice is in fact comparable to
what is reported in the Mn compound. This reinforces the conclusion that the
spin canting transition is associated with the ordering of vanadium orbitals in
this system, and closer analysis indicates closely related physics underlying
orbital transitions in $\mathrm{FeV_2O_4}$ and $\mathrm{MnV_2O_4}$.",1403.0269v2
2017-04-06,Electronic structure and magnetic properties of magnetically dead layers in epitaxial CoFe2O4/Al2O3/Si(111) films studied by X-ray magnetic circular dichroism,"Epitaxial CoFe2O4/Al2O3 bilayers are expected to be highly efficient spin
injectors into Si owing to the spin filter effect of CoFe2O4. To exploit the
full potential of this system, understanding the microscopic origin of
magnetically dead layers at the CoFe2O4/Al2O3 interface is necessary. In this
paper, we study the crystallographic and electronic structures and the magnetic
properties of CoFe2O4(111) layers with various thicknesses (thickness d = 1.4,
2.3, 4, and 11 nm) in the epitaxial CoFe2O4(111)/Al2O3(111)/Si(111) structures
using soft X-ray absorption spectroscopy (XAS) and X-ray magnetic circular
dichroism (XMCD) combined with cluster-model calculation. The magnetization of
CoFe2O4 measured by XMCD gradually decreases with decreasing thickness d and
finally a magnetically dead layer is clearly detected at d = 1.4 nm. The
magnetically dead layer has frustration of magnetic interactions which is
revealed from comparison between the magnetizations at 300 and 6 K. From
analysis using configuration-interaction cluster-model calculation, the
decrease of d leads to a decrease in the inverse-to-normal spinel structure
ratio and also a decrease in the average valence of Fe at the octahedral sites.
These results strongly indicate that the magnetically dead layer at the
CoFe2O4/Al2O3 interface originates from various complex networks of
superexchange interactions through the change in the crystallographic and
electronic structures. Furthermore, from comparison of the magnetic properties
between d = 1.4 and 2.3 nm, it is found that ferrimagnetic order of the
magnetically dead layer at d = 1.4 nm is restored by the additional growth of
the 0.9-nm-thick CoFe2O4 layer on it.",1704.01712v1
2017-04-13,Low energy magnon dynamics and magneto-optics of the skyrmionic Mott insulator Cu$_2$OSeO$_3$,"In this work, we present a comprehensive study of the low energy optical
magnetic response of the skyrmionic Mott insulator Cu$_2$OSeO$_3$ via high
resolution time-domain THz spectroscopy. In zero field, a new magnetic
excitation not predicted by spin-wave theory with frequency $f$ = 2.03 THz is
observed and shown, with accompanying time-of-flight neutron scattering
experiments, to be a zone folded magnon from the $\mathrm{R}$ to
$\mathrm{\Gamma}$ points of the Brillouin zone. Highly sensitive polarimetry
experiments performed in weak magnetic fields, $\mu_0$H $<$ 200 mT, observe
Faraday and Kerr rotations which are proportional to the sample magnetization,
allowing for optical detection of the skyrmion phase and construction of a
magnetic phase diagram. From these measurements, we extract a critical exponent
of $\beta$ = 0.35 $\pm$ 0.04, in good agreement with the expected value for the
3D Heisenberg universality class of $\beta$ = 0.367. In large magnetic fields,
$\mu_0$H $>$ 5 T, we observe the magnetically active uniform mode of the
ferrimagnetic field polarized phase whose dynamics as a function of field and
temperature are studied. In addition to extracting a $g_\text{eff}$ = 2.08
$\pm$ 0.03, we observe the uniform mode to decay through a non-Gilbert damping
mechanism and to possesses a finite spontaneous decay rate, $\Gamma_0$
$\approx$ 25 GHz, in the zero temperature limit. Our observations are
attributed to Dzyaloshinkii-Moriya interactions, which have been proposed to be
exceptionally strong in Cu$_2$OSeO$_3$ and are expected to impact the low
energy magnetic response of such chiral magnets.",1704.04228v1
2018-05-17,Large magneto-optical Kerr effect and imaging of magnetic octupole domains in an antiferromagnetic metal,"When a polarized light beam is incident upon the surface of a magnetic
material, the reflected light undergoes a polarization rotation. This
magneto-optical Kerr effect (MOKE) has been intensively studied in a variety of
ferro- and ferrimagnetic materials because it provides a powerful probe for
electronic and magnetic properties as well as for various applications
including magneto-optical recording. Recently, there has been a surge of
interest in antiferromagnets (AFMs) as prospective spintronic materials for
high-density and ultrafast memory devices, owing to their vanishingly small
stray field and orders of magnitude faster spin dynamics compared to their
ferromagnetic counterparts. In fact, the MOKE has proven useful for the study
and application of the antiferromagnetic (AF) state. Although limited to
insulators, certain types of AFMs are known to exhibit a large MOKE, as they
are weak ferromagnets due to canting of the otherwise collinear spin structure.
Here we report the first observation of a large MOKE signal in an AF metal at
room temperature. In particular, we find that despite a vanishingly small
magnetization of $M \sim$0.002 $\mu_{\rm B}$/Mn, the non-collinear AF metal
Mn$_3$Sn exhibits a large zero-field MOKE with a polar Kerr rotation angle of
20 milli-degrees, comparable to ferromagnetic metals. Our first-principles
calculations have clarified that ferroic ordering of magnetic octupoles in the
non-collinear Neel state may cause a large MOKE even in its fully compensated
AF state without spin magnetization. This large MOKE further allows imaging of
the magnetic octupole domains and their reversal induced by magnetic field. The
observation of a large MOKE in an AF metal should open new avenues for the
study of domain dynamics as well as spintronics using AFMs.",1805.06758v1
2013-09-05,Magnetic interactions in disordered perovskite PbFe_{1/2}Nb_{1/2}O_3 and related compounds. Dominance of nearest-neighbor interaction,"We show that the magnetism of double perovskite AFe_{1/2}M_{1/2}O_3 systems
may be described by the Heisenberg model on the simple cubic lattice, where
only half of sites are occupied by localized magnetic moments. The
nearest-neighbor interaction J_1 is more than 20 times the next-nearest
neighbor interaction J_2, the third-nearest interaction along the space
diagonal of the cube being negligible. We argue that the variety of magnetic
properties observed in different systems is connected with the variety of
chemical ordering in them. We analyze six possible types of the chemical
ordering in 2x2x2 supercell, and argue that the probability to find them in a
real compound does not correspond to a random occupation of lattice sites by
magnetic ions. The exchange J_2 rather than J_1 define the magnetic energy
scale of most double perovskite compounds that means the enhanced probability
of 1:1 short range ordering. Two multiferroic compounds PbFe_{1/2}M_{1/2}O_3
(M=Nb, Ta) are exceptions. We show that the relatively high temperature of
antiferromagnetic transition is compatible with a layered short-range chemical
order, which was recently shown to be most stable for these two compounds [I.
P. Raevski, {\em et al.}, Phys.\ Rev.\ B \textbf{85}, 224412 (2012)]. We show
also that one of the types of ordering has ferrimagnetic ground state. The
clusters with short-range order of this type may be responsible for a
room-temperature superparamagnetism, and may form the cluster glass at low
temperatures.",1309.1318v3
2016-05-26,"Long-range and short-range magnetic correlations, and microscopic origin of net magnetization in the spin-1 trimer chain compound CaNi3P4O14","Spin-spin correlations and microscopic origin of net magnetization in the
spin-1 trimer chain compound CaNi3P4O14 have been investigated by powder
neutron diffraction. The present study reveals a 3D long-range magnetic
ordering below 16 K where the magnetic structure consists of ferromagnetic
trimers that are coupled ferromagnetically along the spin-chain. The moment
components along the a and c axes arrange antiferromagnetically. Our study
establishes that the uncompensated moment components along the b axis result in
a net magnetization per unit cell. The magnetic structure, determined in the
present study, is in agreement with the results of recent first principles
calculation; however, it is in contrast to a fascinating experimental
prediction of ferrimagnetic ordering based on the periodicity of the exchange
interactions in CaNi3P4O14. Our study also confirms the presence of broad
diffuse magnetic scattering, due to 1D short-range spin-spin correlations, over
a wide temperature range below ~50 K down to a temperature well below the Tc.
Total neutron scattering analysis by the RMC method reveals that the dominating
spin-spin correlation above Tc is ferromagnetic and along the b axis. The
nearest neighbour spin-spin correlations along the a and c axes are found to be
weakly antiferromagnetic. The nature of the trimer spin structure of the
short-range state is similar to that of the 3D long-range ordered state. The
present investigation of microscopic nature of the magnetic ground state also
explains the condition required for the 1/3 magnetization plateau to be
observed in the trimer spin-chains. In spite of the S=1 trimer chain system,
the present compound CaNi3P4O14 is found to be a good realization of 3D magnet
below the Tc=16 K with full ordered moment values of ~2 mu_B/Ni2+ (1.98 and
1.96 mu_B/Ni2+ for two Ni sites, respectively) at 1.5 K.",1605.08210v1
2016-12-15,Magnons and Magnetodielectric Effects in CoCr$_2$O$_4$: Raman Scattering Studies,"Magnetoelectric materials have generated wide technological and scientific
interest because of the rich phenomena these materials exhibit, including the
coexistence of magnetic and ferroelectric orders, magnetodielectric behavior,
and exotic hybrid excitations such as electromagnons. The multiferroic spinel
material, CoCr$_2$O$_4$, is a particularly interesting example of a
multiferroic material, because evidence for magnetoelectric behavior in the
ferrimagnetic phase seems to conflict with traditional noncollinear-spin-driven
mechanisms for inducing a macroscopic polarization. This paper reports an
inelastic light scattering study of the magnon and phonon spectrum of
CoCr$_2$O$_4$ as simultaneous functions of temperature, pressure, and magnetic
field. Below the Curie temperature ($T_C \sim 94$ K) of CoCr$_2$O$_4$ we
observe a $\omega \sim 16 \,\text{cm}^{-1}$ $\boldsymbol q=0$ magnon having
T$_{1g}$-symmetry, which has the transformation properties of an axial vector.
The anomalously large Raman intensity of the T$_{1g}$-symmetry magnon is
characteristic of materials with a large magneto-optical response and likely
arises from large magnetic fluctuations that strongly modulate the dielectric
response in CoCr$_2$O$_4$. The Raman susceptibility of the T$_{1g}$-symmetry
magnon exhibits a strong magnetic-field dependence that is consistent with the
magnetodielectric response observed in CoCr$_2$O$_4$, suggesting that
magnetodielectric behavior in CoCr$_2$O$_4$ primarily arises from the
field-dependent suppression of magnetic fluctuations that are strongly coupled
to long-wavelength phonons. Increasing the magnetic anisotropy in CoCr$_2$O$_4$
with applied pressure decreases the magnetic field-dependence of the
T$_{1g}$-symmetry magnon Raman susceptibility in CoCr$_2$O$_4$, suggesting that
strain can be used to control the magnetodielectric response in CoCr$_2$O$_4$.",1612.05283v1
2016-12-23,Field Induced Magnetic States in Holmium Tetraboride,"A study of the zero field and field induced magnetic states of the frustrated
rare earth tetraboride, HoB$_4$, has been carried out using single crystal
neutron diffraction complemented by magnetisation measurements. In zero field,
HoB$_4$ shows magnetic phase transitions at $T_{\mathrm{N1}}$ = 7.1 K to an
incommensurate state with a propagation vector ($\delta$, $\delta$, $\delta'$),
where $\delta$ = 0.02 and $\delta'$ = 0.43 and at $T_{\mathrm{N2}}$ = 5.7 K to
a non-collinear commensurate antiferromagnetic structure. Polarised neutron
diffraction measurements in zero field have revealed that the incommensurate
reflections, albeit much reduced in intensity, persist down to 1.5 K despite
antiferromagnetic ordering at 5.7 K. At lower temperatures, application of a
magnetic field along the $c$-axis initially re-establishes the incommensurate
phase as the dominant magnetic state in a narrow field range, just prior to
HoB$_4$ ordering with an up-up-down ferrimagnetic structure characterised by
the $(h,k,\frac{1}{3})$-type reflections between 18 and 24 kOe. This field
range is marked by the previously reported $M/M_{\mathrm{sat}}$= $\frac{1}{3}$
magnetisation plateau, which we also see in our magnetisation measurements. The
region between 21 and 33 kOe is characterised by the increase in the intensity
of the antiferromagnetic reflections, such as (100), the maximum of which
coincides with the appearance of the narrow magnetisation plateau with
$M/M_{\mathrm{sat}}\approx$ $\frac{3}{5}$. Further increase of the magnetic
field results in the stabilisation of a polarised state above 33 kOe, while the
incommensurate reflections are clearly present in all fields up to 59 kOe. We
propose the $H-T$ phase diagram of HoB$_4$ for the $H \parallel c$ containing
both stationary and transitionary magnetic phases which overlap and show
significant history dependence.",1612.08025v1
2018-01-24,$Ab-initio$ investigation of the thermodynamics of cation distribution and the electronic and magnetic structures in the LiMn$_2$O$_4$ spinel,"The spinel-structured lithium manganese oxide (LiMn$_2$O$_4$) is a material
currently used as cathode for secondary lithium-ion batteries, but whose
properties are not yet fully understood. Here, we report a computational
investigation of the inversion thermodynamics and electronic behaviour of
LiMn$_2$O$_4$ derived from spin-polarised density functional theory
calculations with a Hubbard Hamiltonian and long-range dispersion corrections
(DFT+$U-$D3). Based on the analysis of the configurational free energy, we have
elucidated a partially inverse equilibrium cation distribution for the
LiMn$_2$O$_4$ spinel. This equilibrium degree of inversion is rationalised in
terms of the crystal field stabilisation effects and the difference between the
size of the cations. We compare the atomic charges with the oxidation numbers
for each degree of inversion. We found segregation of the Mn charge once these
ions occupy the tetrahedral and octahedral sites of the spinel. We have
obtained the atomic projections of the electronic band structure and density of
states, showing that the normal LiMn$_2$O$_4$ has half-metallic properties,
while the fully inverse spinel is an insulator. This material is in the
ferrimagnetic state for the inverse and partially inverse cation arrangement.
The optimised lattice and oxygen parameters, as well as the equilibrium degree
of inversion, are in agreement with the available experimental data. The
partially inverse equilibrium degree of inversion is important in the
interpretation of the lithium ion migration and surface properties of the
LiMn$_2$O$_4$ spinel.",1801.08013v1
2018-09-06,Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys,"Sub-picosecond magnetisation manipulation via femtosecond optical pumping has
attracted wide attention ever since its original discovery in 1996. However,
the spatial evolution of the magnetisation is not yet well understood, in part
due to the difficulty in experimentally probing such rapid dynamics. Here, we
find evidence of rapid magnetic order recovery in materials with perpendicular
magnetic anisotropy via nonlinear magnon processes. We identify both
localisation and coalescence regimes, whereby localised magnetic textures
nucleate and subsequently evolve in accordance with a power law formalism.
Coalescence is observed for optical excitations both above and below the
switching threshold. Simulations indicate that the ultrafast generation of
noncollinear magnetisation via optical pumping establishes exchange-mediated
spin currents with an equivalent 100% spin polarised charge current density of
$10^8$ A/cm$^2$. Such large spin currents precipitate rapid recovery of
magnetic order after optical pumping. These processes suggest an ultrafast
optical route for the stabilization of desired meta-stable states, e.g.,
isolated skyrmions.",1809.02076v2
2018-09-11,Neutron Scattering Investigation of Rhenium Orbital Ordering in $3d-5d$ Double Perovskite Ca$_2$FeReO$_6$,"We have carried out inelastic neutron scattering experiments to study
magnetic excitations in ordered double perovskite Ca$_2$FeReO$_6$. We found a
well-defined magnon mode with a bandwidth of $\sim$50meV below the
ferri-magnetic ordering temperature ($T_c\sim$520K), similar to previously
studied Ba$_2$FeReO$_6$. The spin excitation is gapless for most temperatures
within the magnetically ordered phase. However, a spin gap of $\sim$10meV opens
up below $\sim$150K, which is well below the magnetic ordering temperature but
coincides with a previously reported metal-insulator transition and onset of
structural distortion. The observed temperature dependence of spin gap provides
strong evidence for ordering of Re orbitals at $\sim$150~K, in accordance with
earlier proposal put forward by Oikawa $\it{et.\,al}$ based on neutron
diffraction [J. Phys. Soc. Jpn., $\bf{72}$, 1411 (2003)] as well as recent
theoretical work by Lee and Marianetti [Phys. Rev. B, $\bf{97}$, 045102
(2018)]. The presence of separate orbital and magnetic ordering in
Ca$_2$FeReO$_6$ suggests weak coupling between spin and orbital degrees of
freedom and hints towards a sub-dominant role played by spin orbit coupling in
describing its magnetism. In addition, we observed only one well-defined magnon
band near magnetic zone boundary, which is incompatible with simple
ferrimagnetic spin waves arising from Fe and Re local moments, but suggests a
strong damping of Re magnon mode.",1809.03647v2
2019-06-18,Multi-analytical characterization of Fe-rich magnetic inclusions in diamonds,"Magnetic mineral inclusions, as iron oxides or sulfides, occur quite rarely
in natural diamonds. Nonetheless, they represent a key tool not only to unveil
the conditions of formation of host diamonds, but also to get hints about the
paleointensity of the geomagnetic field present at times of the Earth's history
otherwise not accessible. This possibility is related to their capability to
carry a remanent magnetization dependent on their magnetic history. However,
comprehensive experimental studies on magnetic inclusions in diamonds have been
rarely reported so far. Here we exploit X-ray diffraction, Synchrotron-based
X-ray Tomographic Microscopy and Alternating Field Magnetometry to determine
the crystallographic, morphological and magnetic properties of ferrimagnetic
Fe-oxides entrapped in diamonds coming from Akwatia (Ghana). We exploit the
methodology to estimate the natural remanence of the inclusions, associated to
the Earth's magnetic field they experienced, and to get insights on the
relative time of formation between host and inclusion systems. Furthermore,
from the hysteresis loops and First Order Reversal Curves we determine
qualitatively the anisotropy, size and domain state configuration of the
magnetic grains constituting the inclusions.",1906.07641v3
2019-09-09,Correlation driven metallic and half-metallic phases in a band insulator,"We demonstrate, using dynamical mean-field theory with the hybridization
expansion continuous time quantum montecarlo impurity solver, a rich phase
diagram with {\em correlation driven metallic and half-metallic phases} in a
simple model of a correlated band insulator, namely, the half-filled ionic
Hubbard model (IHM) with first {\em and} second neighbor hopping ($t$ and
$t'$), an on-site repulsion $U$, and a staggered potential $\Delta$. Without
$t'$ the IHM has a direct transition from a paramagnetic band insulator (BI) to
an antiferromagnetic Mott insulator (AFI) phase as $U$ increases. For weak to
intermediate correlations, $t'$ frustrates the AF order, leading to a
paramagnetic metal (PM) phase, a ferrimagnetic metal (FM) phase and an
anti-ferromagnetic half-metal (AFHM) phase in which electrons with one spin
orientation, say up-spin, have gapless excitations while the down-spin
electrons are gapped. For $t'$ less than a threshold $ t_1$, there is a direct,
first-order, BI to AFI transition as $U$ increases, as for $t'=0$; for $t_4< t'
< \Delta/2$, the BI to AFI transition occurs via an intervening PM phase. For
$t' > \Delta/2$, there is no BI phase, and the system has a PM to AFI
transition as $U$ increases. In an intermediate-range $t_2 < t' < t_3$, as $U$
increases the system undergoes four transitions, in the sequence BI
$\rightarrow$ PM $\rightarrow$ FM $\rightarrow$ AFHM $\rightarrow$ AFI; the FM
phase is absent in the ranges of $t'$ on either side, implying three
transitions. The BI-PM, FM-AFHM and AFHM-AFI transitions, and a part of the
PM-FM transition are continuous, while the rest of the transitions are first
order in nature. The PM, FM and the AFHM phases have, respectively, spin
symmetric, partially polarized and fully polarized electron [hole] pockets
around the ($\pm\pi/2$, $\pm\pi/2$) [($\pm \pi, 0$), ($0. \pm \pi$)] points in
the Brillouin zone.",1909.03893v1
2019-09-10,Contributions of magnetic structure and nitrogen to perpendicular magnetocrystalline anisotropy in antiperovskite $ε$-Mn$_4$N,"To study how nitrogen contributes to perpendicular magnetocrystalline
anisotropy (PMA) in the ferrimagnetic antiperovskite Mn$_4$N, we examined both
the fabrication of epitaxial Mn$_4$N films with various nitrogen contents and
first-principles density-functional calculations. Saturation magnetization
($M_{\rm s}$) peaks of 110 mT and uniaxial PMA energy densities ($K_{\rm u}$)
of 0.1 MJ/m$^3$ were obtained for a N$_2$ gas flow ratio ($Q$) of $\sim 10 \%$
during sputtering deposition, suggesting nearly single-phase crystalline
$\epsilon$-Mn$_4$N. Segregation of $\alpha$-Mn and nitrogen-deficient Mn$_4$N
grains was observed for $Q \approx 6\%$, which was responsible for a decrease
in the $M_{\rm s}$ and $K_{\rm u}$. The first-principles calculations revealed
that the magnetic structure of Mn$_4$N showing PMA was ""type-B"" having a
collinear structure, whose magnetic moments couple parallel within the c-plane
and alternating along the c-direction. In addition, the $K_{\rm u}$ calculated
using Mn$_{32}$N$_x$ supercells showed a strong dependence on nitrogen
deficiency, in qualitative agreement with the experimental results. The
second-order perturbation analysis of $K_{\rm u}$ with respect to the
spin-orbit interaction revealed that not only spin-conserving but also
spin-flip processes contribute significantly to the PMA in Mn$_4$N. We also
found that both contributions decreased with increasing nitrogen deficiency,
resulting in the reduction of $K_{\rm u}$. It was noted that the decrease in
the spin-flip contribution occurred at the Mn atoms in face-centered sites.
This is one of the specific PMA characteristics we found for
antiperovskite-type Mn$_4$N.",1909.04308v3
2020-01-09,Bismuth iron garnet: ab initio study of electronic properties,"Bismuth iron garnet (BIG), i.e. Bi3Fe5O12, is a strong ferrimagnet that also
possess outstanding magneto-optical properties such as the largest known
Faraday rotation. These properties are related with the distribution of
magnetic moments on octahedral and tetrahedral sites, the presence of spin gaps
in the density of state and a strong spin-orbit coupling. In this work,
first-principles ab initio calculations are performed to study the structural,
electronic and magnetic properties of BIG using Density Functional Theory with
Hubbard+U (DFT+U) correction including spin-orbit coupling and HSE06 hybrid
functional. We found that the presence of spin gaps in the electronic structure
results from the interplay between exchange and correlation effects and the
crystal field strengths for tetrahedral and octahedral iron sublattices. The
DFT+U treatment tends to close the spin-gaps for larger U due to
over-localization effects, notably in the octahedral site. On the other hand,
the hybrid functional confirms the occurrences of three spin gaps in the iron
states of the conduction band as expected from optical measurements. A strong
exchange splitting at the top of the valence bands associated with a lone-pair
type mixture of O p and Bi s,p states is also obtained. Similar exchange
splitting was not previously observed for other iron based garnets, such as for
yttrium iron garnet. It follows that hole doping, as obtained by Ca
substitution at Bi sites, results in a full spin polarized density at the Fermi
energy. This work helps to shed more light on the theoretical comprehension of
the properties of BIG and opens the route towards the use of advanced Many Body
calculations to predict the magneto-optical coupling effects in BIG in a direct
comparison with the experimental measurements.",2001.02910v1
2020-01-21,"Mechanical behavior, enhanced dc resistivity, energy band gap and high temperature magnetic properties of Y-substituted Mg-Zn ferrites","We report the synthesis of Y-substituted Mg-Zn ferrites using conventional
standard ceramic technique. XRD patterns confirm the single phase cubic spinel
structure up to x = 0.03 and appearance of a secondary phase of YFeO3for higher
Y contents. FESEM images depict the distribution of grains and EDS spectra
confirmed the absence of any unwanted element. Completion of solid state
reaction and formation of spinel structure has been revealed from FTIR spectra.
The FTIR data along with lattice constant, bulk density and porosity were
further used to calculate the stiffness constant (Cij), elastic constant and
Debye temperatures. Mechanical stability of all studied compositions is
confirmed from Cij using Born stability conditions. Brittleness and isotropic
nature are also confirmed using Poisson ratio and anisotropy constants,
respectively. The enhancement of dc electrical resistivity with Y content is
observed. The energy band gap (increased with Y contents) is found in good
agreement with dc electrical resistivity. Ferrimagnetic to paramagnetic phase
change has been observed from the field dependent high temperature
magnetization curves. The magnetic moments and saturation magnetization were
found to be decreased with increasing temperature. The Curie temperature (Tc)
has been measured from temperature dependent magnetic moment (M-T) and initial
permeability and found to be in good agreement with each other. Decrease in Tc
with Y content is due to redistribution of cations and weakening of the
exchange coupling constant. The magnetic phase transition has been analyzed by
Arrott plot and found to have second order phase transition. The dc resistivity
endorses the prepared ferrites are suitable for high frequency and high
temperature magnetic device applications as well.",2001.07313v1
2020-04-08,High-order crystal field and rare-earth magnetism in RECo5 intermetallics,"Crystal-field (CF) effects on the rare-earth (RE) ions in ferrimagnetic
intermetallics NdCo$_5$ and TbCo$_5$ are evaluated using an ab initio density
functional + dynamical mean-field theory approach in conjunction with a
quasi-atomic approximation for on-site electronic correlations on the localized
4$f$ shell. The study reveals an important role of the high-order sectoral
harmonic component of the CF in the magnetism of RECo$_5$ intermetallics. An
unexpectedly large value is computed in the both systems for the corresponding
crystal-field parameter (CFP) $A_6^6 \langle r^6 \rangle$, far beyond what one
would expect from only electrostatic contributions. It allows solving the
enigma of the non-saturation of zero-temperature Nd magnetic moments in
NdCo$_5$ along its easy axis in the Co exchange field. This unsaturated state
had been previously found out from magnetization distribution probed by
polarised neutron elastic scattering but had so far remained theoretically
unexplained. The easy plane magnetic anisotropy of Nd in NdCo$_5$ is strongly
enhanced by the large value of $A_6^6\langle r^6 \rangle$. Counter-intuitively,
the polar dependence of anisotropy energy within the easy plane remains rather
small. The easy plane magnetic anisotropy of Nd is reinforced up to high
temperatures, which is explained through $J$-mixing effects. The calculated ab
initio anisotropy constants of NdCo$_5$ and their temperature dependence are in
quantitative agreement with experiment. Unlike NdCo$_5$, the $A_6^6 \langle r^6
\rangle$ CFP has negligible effects on the Tb magnetism in TbCo$_5$ suggesting
that its impact on the RE magnetism is ion-specific across the RECo$_5$ series.
The origin of its large value is the hybridization of RE and Co states in a
hexagonally coordinated local environment of the RE ion in RECo$_5$
intermetallics.",2004.03945v1
2020-04-17,Spin and orbital magnetic moments in perpendicularly magnetized Ni$_{1-x}$Co$_{2+y}$O$_{4-z}$ epitaxial thin films: Effects of site-dependent cation valence states,"We carried out x-ray absorption spectroscopy (XAS) and x-ray magnetic
circular dichroism (XMCD) spectroscopy and investigated cation valence states
and spin and orbital magnetic moments in the inverse-spinel ferrimagnet
Ni$_{1-x}$Co$_{2+y}$O$_{4-z}$ (NCO) epitaxial films with the perpendicular
magnetic anisotropy. We show that the oxygen pressure P$_{O2}$ during the film
growth by pulsed laser deposition influences not only the cation stoichiometry
(site-occupation) but also the cation valence state. Our XAS results show that
the Ni in the O$_{h}$-site is in the intermediate valence state between +2 and
+3, Ni$^{(2+\delta)+}$ (0<$\delta$<1), whose nominal valence state (the
$\delta$ value) varies depending on P$_{O2}$. On the other hand, the Co in the
octahedral (O$_{h}$) and tetrahedral (T$_{d}$) sites respectively have the
valence state close to +3 and +2. We also find that the XMCD signals originate
mainly from the T$_{d}$-site Co$^{2+}$ (Co$_{Td}$) and O$_{h}$-site
Ni$^{(2+\delta)+}$ (Ni$_{Oh}$), indicating that these cation valence states are
the key in determining the magnetic and transport properties of NCO films.
Interestingly, the valence state of Ni$^{(2+\delta)+}$ that gives rise to the
XMCD signal remains unchanged independent of P$_{O2}$. The electronic structure
of Ni$^{(2+\delta)+}$ that is responsible for the magnetic moment and
electrical conduction differs from those of Ni$^{2+}$ and Ni$^{3+}$. In
addition, the orbital magnetic moment originating from Co$_{Td}$ is as large as
0.14 $\mu_{B}/Co_{Td}$ and parallel to the magnetization while the Ni$_{Oh}$
orbital moment is as small as 0.07 $\mu_{B}/Ni_{Oh}$ and is rather isotropic.
The Co$_{Td}$ therefore plays the key role in the perpendicular magnetic
anisotropy of the films. Our results demonstrate the significance of the
site-dependent cations valence states for the magnetic and transport properties
of NCO films.",2004.08104v1
2020-12-17,Identifying the origin of the non-monotonic thickness dependence of spin-orbit torques and interfacial Dzyaloshinskii-Moriya interaction in a ferrimagnetic insulator heterostructure,"Electrical manipulation of magnetism via spin-orbit torques (SOTs) promises
efficient spintronic devices. In systems comprising magnetic insulators and
heavy metals, SOTs have started to be investigated only recently, especially in
systems with interfacial Dzyaloshinskii-Moriya interaction (iDMI). Here, we
quantitatively study the SOT efficiency and iDMI in a series of gadolinium
gallium garnet (GGG) / thulium iron garnet (TmIG) / platinum (Pt)
heterostructures with varying TmIG and Pt thicknesses. We find that the
non-monotonic SOT efficiency as a function of the magnetic layer thickness is
not consistent with the 1/thickness dependence expected from a simple
interfacial SOT mechanism. Moreover, considering the insulating nature of TmIG,
our results cannot be explained by the SOT mechanism established for metallic
magnets where the transverse charge spin current can inject and dephase in the
magnetic layers. Rather we can explain this non-monotonic behavior by a model
based on the interfacial spin mixing conductance that is affected by the
thickness-dependent exchange splitting energy by determining the phase
difference of the reflected spin-up and spin-down electrons at the TmIG / Pt
interface. By studying the Pt thickness dependence, we find that the effective
DMI for GGG / TmIG / Pt does not depend on the Pt thickness, which indicates
that the GGG / TmIG interface is the source of the iDMI in this system. Our
work demonstrates that SOT and DMI can originate from two different interfaces,
which enables independent optimization of DMI and SOT for advanced chiral
spintronics with low damping magnetic insulators.",2012.09358v1
2021-01-25,Computing and Memory Technologies based on Magnetic Skyrmions,"Solitonic magnetic excitations such as domain walls and, specifically,
skyrmionics enable the possibility of compact, high density,
ultrafast,all-electronic, low-energy devices, which is the basis for the
emerging area of skyrmionics. The topological winding of skyrmion spins affects
their overall lifetime, energetics and dynamical behavior. In this review, we
discuss skyrmionics in the context of the present day solid state memory
landscape, and show how their size, stability and mobility can be controlled by
material engineering, as well as how they can be nucleated and detected.
Ferrimagnetsnear their compensation points are important candidates for this
application, leading to detailed exploration of amorphous CoGd as well as the
study of emergent materials such as Mn$_4$N and Inverse Heusler alloys. Along
with material properties, geometrical parameters such as film thickness, defect
density and notches can be used to tune skyrmion properties, such as their size
and stability. Topology, however, can be a double-edged sword, especially for
isolated metastable skyrmions, as it brings stability at the cost of additional
damping and deflective Magnus forces compared to domain walls. Skyrmion
deformation in response to forces also makes them intrinsically slower than
domain walls. We explore potential analog applications of skyrmions, including
temporal memory at low density, and decorrelator for stochastic computing at a
higher density that capitalizes on their interactions. We summarize the main
challenges to achieve a skyrmionics technology, including maintaining
positional stability with very high accuracy, electrical readout, especially
for small ferrimagnetic skyrmions, deterministic nucleation and annihilation,
and overall integration with digital circuits with the associated circuit
overhead.",2101.09947v4
2018-08-03,Ground-State Phase Diagram of an Anisotropic S=1/2 Ladder with Different Leg Interactions,"We explore the ground-state phase diagram of the $S=1/2$ two-leg ladder with
different leg interactions. The $xy$ and $z$ components of the leg interactions
between nearest-neighbor spins in the $a$ ($b$) leg are respectively denoted by
$J_{{\rm l},a}$ and $\Delta_{\rm l} J_{{\rm l},a}$ ($J_{{\rm l},b}$ and
$\Delta_{\rm l} J_{{\rm l},b}$). On the other hand, the $xy$ and $z$ components
of the uniform rung interactions are respectively denoted by $\Gamma_{\rm r}
J_{{\rm r}}$ and $J_{{\rm r}}$. In the above, $\Delta_{\rm l}$ and $\Gamma_{\rm
r}$ are the $XXZ$-type anisotropy parameters for the leg and rung interactions,
respectively. This system has a frustration when $J_{{\rm l},a} J_{{\rm
l},b}<0$ irrespective of the sign of $J_{\rm r}$. The phase diagram on the
$\Delta_{\rm l}$ ($|\Delta_{\rm l}| \leq 1.0$) versus $J_{{\rm l},b}$
($-2.0\leq J_{{\rm l},b}\leq 3.0$) plane in the case where $J_{{\rm l},a}=0.2$,
$J_{{\rm r}}=-1.0$, and $\Gamma_{\rm r} = 0.5$ is determined numerically. We
employ the physical consideration, and the level spectroscopy and
phenomenological renormalization-group analyses of the numerical date obtained
by the exact diagonalization method. The resultant phase diagram contains the
ferromagnetic, Haldane, N{\'e}el, nematic Tomonaga-Luttinger liquid (TLL),
partial ferrimagnetic, and $XY1$ phases. Interestingly enough, the nematic TLL
phase appears in the strong-rung unfrustrated region as well as in the
strong-rung frustrated one. We perform the first-order perturbational
calculations from the strong rung coupling limit to elucidate the
characteristic features of the phase diagram. Furthermore, we make the
density-matrix renormalization-group calculations for some physical quantities
such as the energy gaps, the local magnetization, and the spin correlation
functions to supplement the reliability of the phase diagram.",1808.01090v2
2019-10-31,Moiré-less Correlations in ABCA Graphene,"Atomically thin van der Waals materials stacked with an interlayer twist have
proven to be an excellent platform towards achieving gate-tunable correlated
phenomena linked to the formation of flat electronic bands. In this work we
demonstrate the formation of emergent correlated phases in multilayer
rhombohedral graphene - a simple material that also exhibits a flat electronic
band but without the need of having a moir\'e superlattice induced by twisted
van der Waals layers. We show that two layers of bilayer graphene that are
twisted by an arbitrary tiny angle host large (micron-scale) regions of uniform
rhombohedral four-layer (ABCA) graphene that can be independently studied.
Scanning tunneling spectroscopy reveals that ABCA graphene hosts an
unprecedentedly sharp flat band of 3-5 meV half-width. We demonstrate that when
this flat band straddles the Fermi level, a correlated many-body gap emerges
with peak-to-peak value of 9.5 meV at charge neutrality. Mean field theoretical
calculations indicate that the two primary candidates for the appearance of
this broken symmetry state are a charge transfer excitonic insulator and a
ferrimagnet. Finally, we show that ABCA graphene hosts surface topological
helical edge states at natural interfaces with ABAB graphene which can be
turned on and off with gate voltage, implying that small angle twisted double
bilayer graphene is an ideal programmable topological quantum material.",1911.00007v2
2019-11-29,"Role of Ni substitution on structural, magnetic and electronic properties of epitaxial CoCr2O4 spinel thin films","Cubic spinel CoCr2O4 has attained recent attention due to its multiferroic
properties. However, the Co site substitution effect on the structural and
magnetic properties has rarely been studied in thin film form. In this work,
the structural and magnetic properties of Co1-xNixCr2O4 (x = 0, 0.5) epitaxial
thin films deposited on MgAl2O4 (100) and MgO (100) substrates to manipulate
the nature of strain in the films using pulsed laser deposition (PLD) technique
are presented. The epitaxial nature of the films was confirmed through X-ray
diffraction (XRD) and Rutherford backscattering spectrometry (RBS)
measurements. Raman measurements revealed a disappearance of characteristic A1g
and F2g modes of the CoCr2O4 with increase in the Ni content. Atomic force
microscopy (AFM) studies show a modification of the surface morphology upon Ni
substitution. Magnetic measurements disclose that the ferrimagnetic Curie
temperature (Tc) of the CoCr2O4 in thin film grown on MgAl2O4 (100) and MgO
(100) substrates were found to be 100.6 +/- 0.5 K and 93.8 +/- 0.2 K,
respectively. With Ni substitution the transition temperatures significantly
get enhanced from that of CoCr2O4. X-ray photoelectron spectroscopy (XPS)
suggests Cr3+ oxidation states in the films, while Co ions are present in a
mixed Co2+/Co3+ oxidation state. The substitution of Ni at Co site
significantly modifies the line shape of the core level as well as the valence
band. Ni ions are also found to be in a mixed 2+/3+ oxidation state. O 1s core
level display asymmetry related to possible defects like oxygen vacancies in
the films.",1912.00051v1
2021-03-02,Anomalous fractional quantization in the kagomelike Heisenberg ladder: Emergence of the effective spin-1 chain,"We study a Kagome-like spin-$1/2$ Heisenberg ladder with competing
ferromagnetic (FM) and antiferromagnetic (AFM) exchange interactions. Using the
density-matrix renormalization group based calculations, we obtain the ground
state phase diagram as a function of the ratio between the FM and AFM exchange
interactions. Five different phases exist. Three of them are spin polarized
phases; an FM phase and two kinds of ferrimagnetic (FR) phases (referred to as
FR1 and FR2 phases). The spontaneous magnetization per site is $m=1/2$, $1/3$,
and $1/6$ in the FM, FR1, and FR2 phases, respectively. This can be understood
from the fact that an effective spin-1 Heisenberg chain formed by the upper and
lower leg spins has a three-step fractional quantization of the magnetization
per site as $m=1$, $1/2$, and $0$. In particular, an anomalous ""intermediate""
state $m=1/2$ of the effective spin-1 chain with the reduced Hilbert space of a
spin from $3$ to $2$ dimensional is highly unexpected in the context of
conventional spin-1 physics. Thus, surprisingly, the effective spin-1 chain
behaves like a spin-1/2 chain with SU(2) symmetry. The remaining two phases are
spin-singlet phases with translational symmetry breaking in the presence of
valence bond formations. One of them is octamer-siglet phase with a spontaneous
octamerization long-range order of the system, and the other is period-4 phase
characterized by the magnetic superstructure with a period of four structural
unit cells. In these spin-singlet phases, we find the coexistence of valence
bond structure and gapless chain. Although this may be emerged through the
order-by-disorder mechanism, there can be few examples of such a coexistence.",2103.01455v2
2021-03-08,All-optical spin switching probability in [Tb/Co] multilayers,"Since the first experimental observation of all-optical switching phenomena,
intensive research has been focused on finding suitable magnetic systems that
can be integrated as storage elements within spintronic devices and whose
magnetization can be controlled through ultra-short single laser pulses. We
report here atomistic spin simulations of all-optical switching in multilayered
structures alternating n monolayers of Tb and m monolayers of Co. By using a
two temperature model, we numerically calculate the thermal variation of the
magnetization of each sublattice as well as the magnetization dynamics of
[Tbn/Com] multilayers upon incidence of a single laser pulse. In particular,
the condition to observe thermally-induced magnetization switching is
investigated upon varying systematically both the composition of the sample
(n,m) and the laser fluence. The samples with one monolayer of Tb as [Tb1/Co2]
and [Tb1/Co3] are showing thermally induced magnetization switching above a
fluence threshold. The reversal mechanism is mediated by the residual
magnetization of the Tb lattice while the Co is fully demagnetized in agreement
with the models developed for ferrimagnetic alloys. The switching is however
not fully deterministic but the error rate can be tuned by the damping
parameter. Increasing the number of monolayers the switching becomes completely
stochastic. The intermixing at the Tb/Co interfaces appears to be a promising
way to reduce the stochasticity. These results predict for the first time the
possibility of TIMS in [Tb/Co] multilayers and suggest the occurrence of
sub-picosecond magnetization reversal using single laser pulses.",2103.05066v1
2021-03-18,Magnetic moment orientation and in depth distribution of dysprosium near the surface of DyCo$_{4.6}$ thin films determined by the analysis of their X ray circularly polarized absorption Dy $M_{5}$ spectra,"We have investigated the RE atomic distribution and its magnetic moment
orientation at the region near the surface of DyCo$_{4.4 \& 4.6}$ ferrimagnetic
amorphous films with perpendicular magnetic anisotropy (PMA). XMCD spectroscopy
of the films at the Dy $M_{4,5}$ and Co $L_{2,3}$ edges using total electron
yield (TEY) detection was performed at 2 K and 300 K temperatures, and at
sample orientations ranged from 0$^{\circ}$ to 70$^{\circ}$ with respect to the
magnetic easy axis. The measurements showed an apparent partial decoupling
between the cobalt and dysprosium magnetic sublattices. At RT, the magnetic
moment per atom of dysprosium was below the minimum value expected if all
dysprosium moments were AF coupled to cobalt. At 2 K, the cobalt sublattice
presented a stronger magnetic anisotropic behavior than the dysprosium
sublattice. A detailed analysis of the circularly polarized spectra of the Dy
$M_{5}$ edge, based on the deconvolution of the spectra in their related
parallel, antiparallel and transverse to $J_{z}$ spectral components,
demonstrates that the spectra are composed by dysprosium with different
magnetic moment distributions. The fit of the Dy $M_{5}$ spectra using the
$J_{z}$ spectral components evidenced a gradation of dysprosium concentration
due to segregation at the region probed by TEY. The topmost layer was
magnetically uncoupled from cobalt. At RT, 25$\%$ of the dysprosium magnetic
moments in the under layer were found averaged oriented in the same direction
as cobalt. The expected weak magnetic coupling of these dysprosium atoms to
cobalt would explain the surprisingly lower magnetic anisotropy of the
dysprosium sublattice compared to that of cobalt probed by TEY at 2 K.",2103.10124v1
2021-04-21,Atomic Layer Deposition of Yttrium Iron Garnet Thin Films for 3D Magnetic Structures,"A wide variety of new phenomena such as novel magnetization configurations
have been predicted to occur in three dimensional magnetic nanostructures.
However, the fabrication of such structures is often challenging due to the
specific shapes required, such as magnetic tubes and spirals. Furthermore, the
materials currently used to assemble these structures are predominantly
magnetic metals that do not allow to study the magnetic response of the system
separately from the electronic one. In the field of spintronics, the
prototypical material used for such experiments is the ferrimagnetic insulator
yttrium iron garnet (Y$_3$Fe$_5$O$_{12}$, YIG). YIG is one of the best
materials especially for magnonic studies due to its low Gilbert damping. Here,
we report the first successful fabrication of YIG thin films via atomic layer
deposition. To that end we utilize a supercycle approach based on the
combination of sub-nanometer thin layers of the binary systems Fe$_2$O$_3$ and
Y$_2$O$_3$ in the correct atomic ratio on Y$_3$Al$_5$O$_{12}$ substrates with a
subsequent annealing step. Our process is robust against typical growth-related
deviations, ensuring a good reproducibility. The ALD-YIG thin films exhibit a
good crystalline quality as well as magnetic properties comparable to other
deposition techniques. One of the outstanding characteristics of atomic layer
deposition is its ability to conformally coat arbitrarily-shaped substrates.
ALD hence is the ideal deposition technique to grant an extensive freedom in
choosing the shape of the magnetic system. The atomic layer deposition of YIG
enables the fabrication of novel three dimensional magnetic nanostructures,
which in turn can be utilized for experimentally investigating the phenomena
predicted in those structures.",2104.10293v2
2021-05-19,Magnetic structure and multiferroicity of Sc-substituted hexagonal YbFeO$_3$,"Hexagonal rare-earth ferrite RFeO$_3$ family represents a unique class of
multiferroics exhibiting weak ferromagnetism, and a strong coupling between
magnetism and structural trimerization is predicted. However, the hexagonal
structure for RFeO$_3$ remains metastable in conventional condition. We have
succeeded in stabilizing the hexagonal structure of polycrystalline YbFeO$_3$
by partial Sc substitution of Yb. Using bulk magnetometry and neutron
diffraction, we find that Yb$_{0.42}$Sc$_{0.58}$FeO$_3$ orders into a canted
antiferromagnetic state with the Neel temperature $T_N$ ~ 165 K, below which
the $Fe^{3+}$ moments form the triangular configuration in the $ab$-plane and
their in-plane projections are parallel to the [100] axis, consistent with
magnetic space group $P$6$_{3}$$c'm'$. It is determined that the spin-canting
is aligned along the $c$-axis, giving rise to the weak ferromagnetism.
Furthermore, the $Fe^{3+}$ moments reorient toward a new direction below
reorientation temperature $T_R$ ~ 40 K, satisfying magnetic subgroup
$P$6$_{3}$, while the $Yb^{3+}$ moments order independently and
ferrimagnetically along the $c$-axis at the characteristic temperature $T_{Yb}$
~ 15 K. Interestingly, reproducible modulation of electric polarization induced
by magnetic field at low temperature is achieved, suggesting that the delicate
structural distortion associated with two-up/one-down buckling of the
Yb/Sc-planes and tilting of the FeO$_5$ bipyramids may mediate the coupling
between ferroelectric and magnetic orders under magnetic field. The present
work represents a substantial progress to search for high-temperature
multiferroics in hexagonal ferrites and related materials.",2105.08931v1
2022-11-13,Field Tunable Magnetic Transitions of CsCo2(MoO4)2(OH): A Triangular Chain Structure with a Frustrated Geometry,"Identifying and characterizing new magnetic systems with Co2+ ions can
enhance our understanding of quantum behavior since Co2+ can host a
pseudospin-1/2 magnetic ground state. Understanding the magnetic ground state
and the phase diagrams of such systems are central to the development of new
theoretical models to described emergent quantum properties of complex magnetic
systems. The sawtooth chain compound, CsCo2MoO4_2OH, is one such complex
magnetic system and here, we present a comprehensive series of magnetic and
neutron scattering measurements to determine its magnetic phase diagram. The
magnetic properties of CsCo2MoO4_2OH exhibit a strong coupling to the crystal
lattice and its magnetic ground state can be easily manipulated by applied
magnetic fields. There are two unique Co2+ ions, base and vertex, with Jbb and
Jbv magnetic exchange. The magnetism is highly anisotropic with the b-axis
(chain) along the easy axis and the material orders antiferromagnetically at TN
= 5 K. The zero field antiferromagnetic phase contains vertex magnetic vectors
Co1 aligned parallel to the b-axis, while the base vectors Co2 are canted by 34
and aligned in an opposite direction to the vertex vectors. The spins in
parallel adjacent chains align in opposite directions, creating an overall
antiferromagnetic structure. At a 3 kOe applied magnetic field, adjacent chains
flip by 180{\deg} to generate a ferrimagnetic phase. An increase in field
gradually induces the Co(1) moment to rotate along the b-axis and align in the
same direction with Co2 generating a ferromagnetic structure. Our results
demonstrate that the CsCo2MoO4_2OH is a promising candidate to study new
physics associated with sawtooth chain magnetism.",2211.07030v1
2022-11-23,"Electronic structure, magnetic properties, spin orientation, and doping effect in Mn$_3$Si$_2$Te$_6$","The layered material Mn$_3$Si$_2$Te$_6$, with alternating stacking honeycomb
and triangular layers, is attracting considerable attention due to its rich
physical properties. Here, using density functional theory and classical Monte
Carlo (MC) methods, we systematically study this system. Near the Fermi level,
the states are mainly contributed by Te $5p$ orbitals hybridized with Mn $3d$
orbitals, resembling a charge transfer system. Furthermore, the spin
orientations of the ferrimagnetic (FiM) ground state display different
conductive behaviors when along the $ab$ plane or out-of-plane directions:
insulating vs. metallic states. The energy difference between the FiM [110]
insulating and FiM [001] metallic phases is very small($ \sim 0.71$ meV/Mn).
Changing the angle $\theta$ of spin orientation from in-plane to out-of-plane
directions, the band gaps of this system are gradually reduced, leading to an
insulator-metal transition, resulting in an enhanced electrical conductivity,
related to the colossal angular magnetoresistance (MR) effect. In addition, we
also constructed the magnetic phase diagram using the classical $XY$ spin model
studied with the MC method. Three magnetic phases were obtained including
antiferromagnetic order, noncollinear spin patterns, and FiM order. Moreover,
we also investigated the Se- and Ge- doping into the Mn$_3$Si$_2$Te$_6$ system:
the FiM state has the lowest energy among the magnetic candidates for both Se-
or Ge- doped cases. The magnetic anisotropy energy (MAE) decreases in the
Se-doped case because the Mn orbital moment is reduced as the doping $x$
increases. Due to the small spin-orbital coupling effect of Se, the
insulator-metal transition caused by the spin orientation disappears in the
Se-doped case, resulting in an insulating phase in the FiM [001] phase. This
causes a reduced colossal angular MR.",2211.13321v2
2022-12-21,Magnetism of the $s=1/2$ $J_1$-$J_2$ square-kagome lattice antiferromagnet,"The spin-$1/2$ Heisenberg antiferromagnet on the square-kagome (SK) lattice
has attracted growing attention as a model system of highly frustrated quantum
magnetism. A further motivation for theoretical studies comes from the recent
discovery of SK spin-liquid compounds. The SK antiferromagnet exhibits two
non-equivalent nearest-neighbor bonds $J_1$ and $J_2$. One may expect that in
SK compounds $J_1$ and $J_2$ are of different strength. We present a numerical
study of finite systems by means of the finite-temperature Lanczos method. We
discuss the temperature dependence of the specific heat $C(T)$, the entropy
$S(T)$, and of the susceptibility $X(T)$ of the $J_1$-$J_2$ SK Heisenberg
antiferromagnet varying $J_2/J_1$ in the range $0 \le J_2/J_1 \le 4$. We also
discuss the zero-field ground state of the model. We find indications for a
magnetically disordered singlet ground state for $0 \le J_2/J_1 \lesssim 1.65$.
Beyond $J_2/J_1 \sim 1.65$ the singlet ground state gives way for a
ferrimagnetic ground state. In the region $0.77 \lesssim J_2/J_1 \lesssim 1.65$
the low-temperature thermodynamics is dominated by a finite singlet-triplet gap
filled with low-lying singlet excitations leading to an exponentially activated
low-temperature behavior of $X(T)$. On the other hand, the low-lying singlets
yield an extra maximum or a shoulder-like profile below the main maximum in the
$C(T)$ curve. For $J_2/J_1 \lesssim 0.7$ the low-temperature thermodynamics is
characterized by a large fraction of $N/3$ weakly coupled spins leading to a
sizable amount of entropy at very low temperatures. In an applied magnetic
field the magnetization process features plateaus and jumps in a wide range of
$J_2/J_1$.",2212.10838v2
2022-12-23,Collective topological spin dynamics in a correlated spin glass,"The interplay between spin-orbit interaction (SOI) and magnetic order is
currently one of the most active research fields in condensed matter physics
and leading the search for materials with novel and tunable magnetic and spin
properties. Here we report on a variety of unexpected and unique observations
in thin multiferroic \Ge$_{1-x}$Mn$_x$Te films. The ferrimagnetic order in this
ferroelectric semiconductor is found to reverse with current pulses six orders
of magnitude lower as for typical spin-orbit torque systems. Upon a switching
event, the magnetic order spreads coherently and collectively over macroscopic
distances through a correlated spin-glass state. Lastly, we present a novel
methodology to controllably harness this stochastic magnetization dynamics,
allowing us to detect spatiotemporal nucleation of topological spin textures we
term ``skyrmiverres''.",2212.12262v1
2023-02-13,QS$G\hat{W}$: Quasiparticle Self consistent $GW$ with ladder diagrams in $W$,"We present an extension of the quasiparticle self-consistent $GW$
approximation (QS$GW$) [Phys. Rev. B, 76 165106 (2007)] to include vertex
corrections in the screened Coulomb interaction $W$. This is achieved by
solving the Bethe-Salpeter equation for the polarization matrix at all
$k$-points in the Brillouin zone. We refer to this method as QS$G\hat{W}$.
QS$GW$ yields a reasonable and consistent description of the electronic
structure and optical response, but systematic errors in several properties
appear, notably a tendency to overestimate insulating bandgaps, blue-shift
plasmon peaks in the imaginary part of the dielectric function, and
underestimate the dielectric constant $\epsilon_{\infty}$. A primary objective
of this paper is to assess to what extent including ladder diagrams in $W$
ameliorates systematic errors for insulators in the QS$GW$ approximation. For
benchmarking we consider about 40 well understood semiconductors, and also
examine a variety of less well characterized nonmagnetic systems, six
antiferromagnetic oxides, and the ferrimagnet Fe$_3$O$_4$. We find ladders
ameliorate shortcomings in QS$GW$ to a remarkable degree in both the one-body
Green's function and the dielectric function for a wide range of insulators.
New discrepancies with experiment appear, and a key aim of this paper is to
establish to what extent the errors are systematic and can be traced to
diagrams missing from the theory. One key finding of this work is to establish
a relation between the bandgap and the dielectric constant $\epsilon_{\infty}$.
Good description of both properties together provides a much more robust
benchmark than either alone. We show how this information can be used to
improve our understanding of the one-particle spectral properties in materials
systems such as SrTiO$_3$ and FeO.",2302.06325v1
2023-05-04,Influence of high pressure on the remarkable itinerant electron behaviour in Y$_{0.7}$Er$_{0.3}$Fe$_2$D$_{4.2}$ compounds,"Monoclinic Y$_{0.7}$Er$_{0.3}$Fe$_2$D$_{4.2}$ compound exhibits unusual
magnetic properties with different field induced magnetic transitions. The
deuteride is ferrimagnetic at low temperature and the Er and Fe sublattices
present magnetic transitions at different temperatures. The Er moments are
ordered below T$_{Er}$=55 K, whereas the Fe moments remain ferromagnetically
coupled up to T$_{M0}$ = 66 K. At T$_{M0}$ the Fe moments display a sharp
ferromagnetic-antiferromagnetic transition (FM-AFM) through an itinerant
electron metamagnetic (IEM) behaviour very sensitive to any volume change.
Y$_{0.7}$Er$_{0.3}$Fe$_2$D$_{4.2}$ becomes paramagnetic above T$_N$=125 K. The
pressure dependence of T$_{Er}$ and T$_{M0}$ have been extracted from magnetic
measurements under hydrostatic pressure up to 0.49 GPa. Both temperatures
decrease linearly upon applied pressure with dT$_{Er}$/dP=-126 and dTM0/dP=-140
K.GPa$^{-1}$ for a field of B=0.03 T. Both magnetic Er and ferromagnetic Fe
order disappear at P=0.44(4) GPa. However, under a larger applied field B=5 T,
dT$_{M0}$/dP=-156 K.GPa$^{-1}$ whereas dT$_{Er}$/dP=-134 K.GPa$^{-1}$ showing a
weaker sensitivity to pressure and magnetic field. At 2 K the decrease of the
saturation magnetization under pressure can be attributed to a reduction of the
mean Er moment due to canting and/or crystal field effect. Above T$_{M0}$ the
magnetization curves display a metamagnetic behaviour from AFM to FM state,
which is also very sensitive to the applied pressure. The transition field
B$_{trans}$, which increases linearly upon heating, is shifted to lower
temperature upon applied pressure with dT=-17 K between 0 and 0.11 GPa. These
results show a strong decoupling of the Er and Fe magnetic sublattices versus
temperature, applied field and pressure.",2305.02698v1
2023-06-19,Onion-like Fe3O4/MgO/CoFe2O4 magnetic nanoparticles: new ways to control magnetic coupling between soft/hard phases,"The control of the magnetization inversion dynamics is one of the main
challenges driving the design of new nanostructured magnetic materials for
magnetoelectronic applications. Nanoparticles with onion-like architecture
offer a unique opportunity to expand the possibilities allowing to combine
different phases at the nanoscale and also modulate the coupling between
magnetic phases by introducing spacers in the same structure. Here we report
the fabrication, by a three-step high temperature decomposition method, of
Fe3O4/MgO/CoFe2O4 onio-like nanoparticles and their detailed structural
analysis, elemental compositional maps and magnetic response. The
core/shell/shell nanoparticles present epitaxial growth and cubic shape with
overall size of (29+-6) nm. These nanoparticles are formed by cubic iron oxide
core of (22+-4) nm covered by two shells, the inner of magnesium oxide and the
outer of cobalt ferrite of ~1 and ~2.5 nm of thickness, respectively. The
magnetization measurements show a single reversion magnetization curve and the
enhancement of the coercivity field, from HC~608 Oe for the Fe3O4/MgO to
HC~5890 Oe to the Fe3O4/MgO/CoFe2O4 nanoparticles at T=5 K, ascribed to the
coupling between both ferrimagnetic phases with a coupling constant of =2
erg/cm2. The system also exhibits exchange bias effect, where the exchange bias
field increases up to HEB~2850 Oe at 5 K accompanied with the broadening of the
magnetization loop of HC~6650 Oe. This exchange bias effect originates from the
freezing of the surface spins below the freezing temperature TF=32 K that
pinned the magnetic moment of the cobalt ferrite shell.",2306.13108v1
2023-08-18,"Magnon Diffusion Length and Longitudinal Spin Seebeck Effect in Vanadium Tetracyanoethylene (V[TCNE]$_x$, $x \sim 2$)","Spintronic, spin caloritronic, and magnonic phenomena arise from complex
interactions between charge, spin, and structural degrees of freedom that are
challenging to model and even more difficult to predict. This situation is
compounded by the relative scarcity of magnetically-ordered materials with
relevant functionality, leaving the field strongly constrained to work with a
handful of well-studied systems that do not encompass the full phase space of
phenomenology predicted by fundamental theory. Here we present an important
advance in this coupled theory-experiment challenge, wherein we extend existing
theories of the spin Seebeck effect (SSE) to explicitly include the
temperature-dependence of magnon non-conserving processes. This expanded theory
quantitatively describes the low-temperature behavior of SSE signals previously
measured in the mainstay material yttrium iron garnet (YIG) and predicts a new
regime for magnonic and spintronic materials that have low saturation
magnetization, $M_S$, and ultra-low damping. Finally, we validate this
prediction by directly observing the spin Seebeck resistance (SSR) in the
molecule-based ferrimagnetic semiconductor vanadium tetracyanoethylene
(V[TCNE]$_x$, $x \sim 2$). These results validate the expanded theory, yielding
SSR signals comparable in magnitude to YIG and extracted magnon diffusion
length ($\lambda_m>1$ $\mu$ m) and magnon lifetime for V[TCNE]$_x$
($\tau_{th}\approx 1-10$ $\mu$ s) exceeding YIG ($\tau_{th}\sim 10$ ns).
Surprisingly, these properties persist to room temperature despite relatively
low spin wave stiffness (exchange). This identification of a new regime for
highly efficient SSE-active materials opens the door to a new class of magnetic
materials for spintronic and magnonic applications.",2308.09752v1
2023-12-19,Magnetism of noncolinear amorphous DyCo3 and TbCo3 thin films,"The magnetization of amorphous DyCo3 and TbCo3 is studied by magnetometry,
anomalous Hall effect and magneto-optic Kerr effect to understand the
temperature-dependent magnetic structure. A square magnetic hysteresis loop
with perpendicular magnetic anisotropy and coercivity that reaches 3.5 T in the
vicinity of the compensation temperature is seen in thin films. An anhysteretic
soft component, seen in the magnetization of some films but not in their Hall
or Kerr loops is an artefact due to sputter-deposition on the sides of the
substrate. The temperature-dependence of the net rare earth moment from 4-300K
is deduced, using the cobalt moment in amorphous YxCo1-x. The single-ion
anisotropy of the quadrupole moments of the 4f atoms in the randomly-oriented
local electrostatic field gradient overcomes their exchange coupling to the
cobalt subnetwork, resulting in a sperimagnetic ground state where spins of the
noncollinear rare-earth subnetwork are modelled by a distribution of rare earth
moments within a cone whose axis is antiparallel to the ferromagnetic axis z of
the cobalt subnetwork. The reduced magnetization (Jz)/J at T=0 is calculated
from an atomic Hamiltonian as a function of the ratio of anisotropy to exchange
energy per rare-earth atom for a range of angles between the local anisotropy
axis and -z and then averaged over all directions in a hemisphere. The
experimental and calculated values of (J-z)/J are close to 0.7 at low
temperature for both Dy and Tb. On increasing temperature, the magnitude of the
rare earth moment and the local random anisotropy that creates the cone are
reduced; the cone closes and the structure approaches collinear ferrimagnetism
well above ambient temperature. An asymmetric spin flop of the exchange-coupled
subnetworks appears in the vicinity of the magnetization compensation
temperatures of 175K for amorphous Dy0.25Co0.75 and 200 K for amorphous TbCo3.",2312.12602v1
2023-12-26,Observation of a 1/3 Magnetisation Plateau Phase as Evidence for the Kitaev Interaction in a Honeycomb-Lattice Antiferromagnet,"Fractional magnetisation plateaus, in which the magnetisation is pinned at a
fraction of its saturated value within a range of external magnetic field, are
spectacular macroscopic manifestations of the collective quantum behaviours.
One prominent example of the plateau phase is found in spin-1/2
triangular-lattice antiferromagnets featuring strong geometrical frustration,
and is often interpreted as quantum-fluctuation-stabilised state in magnetic
field via the ""order-by-disorder"" mechanism. Here, we observe an unprecedented
1/3 magnetisation plateau between 5.2 and 7.4 T at 2 K in a spin-1
antiferromagnet Na$_3$Ni$_2$BiO$_6$ with a honeycomb lattice, where
conventionally no geometrical frustration is anticipated. By carrying out
elastic neutron scattering measurements, we propose the spin structure of the
plateau phase to be an unusual partial spin-flop ferrimagnetic order,
transitioning from the zigzag antiferromagnetic order in zero field. Our
theoretical calculations show that the plateau phase is stabilised by the
bond-anisotropic Kitaev interaction. These results provide a new paradigm for
the exploration of rich quantum phases in frustrated magnets and exotic Kitaev
physics in high-spin systems.",2312.15932v1
2024-02-22,Laser patterning of magnonic structure via local crystallization of Yittrium Iron Garnet,"The fabrication and integration of high-quality structures of Yttrium Iron
Garnet (YIG) is critical for magnonics.Films with excellent properties are
obtained only on single crystal Gadolinium Gallium Garnet (GGG) substrates
using high-temperature processes. The subsequent realization of magnonic
structures via lithography and etching is not straightforward as it requires a
tight control of the edge roughness, to avoid magnon scattering, and
planarization in case of multilayer devices. In this work we describe a
different approach based on local laser annealing of amorphous YIG films,
avoiding the need for subjecting the entire sample to high thermal budgets and
for physical etching. Starting from amorphous and paramagnetic YIG films grown
by pulsed laser deposition at room temperature on GGG, a 405 nm laser is used
for patterning arbitrary shaped ferrimagnetic structures by local
crystallization. In thick films (160 nm) the laser induced surface corrugation
prevents the propagation of spin-wave modes in patterned conduits. For thinner
films (80 nm) coherent propagation is observed in 1.2 micron wide conduits
displaying an attenuation length of 5 micron which is compatible with a damping
coefficient of about 5e-3. Possible routes to achieve damping coefficients
compatible with state-of-the art epitaxial YIG films are discussed.",2402.14444v1
2000-03-22,Resonance Paramagnetic Relaxation and Alignment of Small Grains,"We show that the energy-level splitting arising from grain rotation ensures
that paramagnetic dissipation acts at its maximum rate, i.e., the conditions
for paramagnetic resonance are automatically fulfilled. We refer to this
process as ``resonance relaxation''. The differences between the predictions of
classical Davis-Greenstein relaxation and resonance relaxation are most
pronounced for grains rotating faster than 1 GHz, i.e., in the domain where
classical paramagnetic relaxation is suppressed. This mechanism can partially
align even very small grains, resulting in linearly polarized microwave
emission which could interfere with efforts to measure the polarization of the
cosmic microwave background.",0003312v2
2002-09-10,Extrasolar Planets and Mean-Motion Resonances,"The 2:1 orbital resonances of the GJ 876 system can be easily established by
the differential planet migration due to planet-nebula interaction. Significant
eccentricity damping is required to produce the observed orbital
eccentricities. The geometry of the GJ 876 resonance configuration differs from
that of the Io-Europa pair, and this difference is due to the magnitudes of the
eccentricities involved. We show that a large variation in the configuration of
2:1 and 3:1 resonances and, in particular, asymmetric librations can be
expected among future discoveries.",0209176v1
2005-06-24,Quasi-Periodic Oscillations Resonantly Induced on Spin-Induced Deformed-Disks of Neutron Stars,"We consider the situation where a spin-induced wavy perturbation is present
on disks of neutron-star low-mass X-ray binaries. By non-linearly coupling with
the perturbation, some modes of disk oscillations resonantly interact with the
disks. We examine the resonant conditions under the assumption that the disks
are vertically isothermal. The results show that when the spin frequency has
some particular values, resonant coupling occurs at some radii. The modes and
frequencies of these resonant oscillations are summarized. Some of these
resonant oscillations seem to explain the frequencies of the observed kHz QPOs
in objects of which the spin frequency is known.",0506595v1
2005-10-31,Behavior of Torsional Alfven Waves and Field Line Resonance on Rotating Magnetars,"Torsional Alfven waves are likely excited with bursts in rotating magnetars.
These waves are probably propagated through corotating atmospheres toward a
vacuum exterior. We have studied the physical effects of the azimuthal wave
number and the characteristic height of the plasma medium on wave transmission.
In this work, explicit calculations were carried out based on the three-layered
cylindrical model. We found that the coupling strength between the internal
shear and the external Alfven modes is drastically enhanced, when resonance
occurs in the corotating plasma cavity. The spatial structure of the
electromagnetic fields in the resonance cavity is also investigated when Alfven
waves exhibit resonance.",0510842v1
1997-03-26,Stochastic Resonance in Chaotic Spin-Wave Dynamics,"We report the first experimental observation of noise-free stochastic
resonance by utilizing the intrinsic chaotic dynamics of the system. To this
end we have investigated the effect of an external periodic modulation on
intermittent signals observed by high power ferromagnetic resonance in yttrium
iron garnet spheres. Both the signal-to-noise ratio and the residence time
distributions show the characteristic features of stochastic resonance. The
phenomena can be explained by means of a one-dimensional intermittent map. We
present analytical results as well as computer simulations.",9703018v1
1999-05-20,Universality in Three-Frequency Resonances,"We investigate the hierarchical structure of three-frequency resonances in
nonlinear dynamical systems with three interacting frequencies. We hypothesize
an ordering of these resonances based on a generalization of the Farey tree
organization from two frequencies to three. In experiments and numerical
simulations we demonstrate that our hypothesis describes the hierarchies of
three-frequency resonances in representative dynamical systems. We conjecture
that this organization may be universal across a large class of three-frequency
systems.",9905034v1
1993-07-25,Resonant Tunneling and the Pauli Principle,"A new method based on modified optical Bloch equations is proposed for
studying resonant tunneling in semiconductor heterostructures. The method
manifestly takes account of electrons' statistics, which enables to investigate
the influence of the Pauli principle on resonant tunneling in presence of
inelastic scattering. Being applied to evaluation of the resonant current in
semiconductor heterostructures, our approach predicts considerable deviations
from the one-electron picture.",9307051v1
1994-04-11,Resonant Transport in Coupled Quantum Wells: a Probe for Scattering Mechanisms,"We present a microscopical theory and experimental results concerning
resistance resonance in two tunneling coupled quantum wells with different
mobilities. The shape of the resonance appears to be sensitive to the small
angle scattering rate on remote impurities and to the electron--electron
scattering rate. This allows the extraction of scattering parameters directly
from the transport measurements. The negative resonance in a Hall coefficient
is predicted and observed for the first time.",9404024v1
1994-10-26,Nonlinear Resonant Tunnelling Through Double Barrier Structures,"We study resonant tunnelling through double-barrier structures under an
applied bias voltage, in which nonlinearities due to self-interaction of
electrons in the barrier regions are included. As an approximation, we concern
ourselves with thin barriers simulated by $\delta$-function potentials. This
approximation allows for an analytical expression of the transmission
probability through the structure. We show that the typical peaks due to
resonant tunneling decrease and broaden as nonlinearity increases. The main
conclusion is that nonlinear effects degrade the peak-to-valley ratio but
improve the maximum operation frequency of the resonant tunnelling devices.",9410092v1
1997-07-30,Resonant Light Scattering to Measure BEC-Pairing,"We present a single-scattering formalism for incoherent resonant light
scattering by dilute quantum gas systems such as the atomic-trap Bose-Einstein
condensates. We show that resonant scattering gives access to more information
than the dynamical structure factor, familiar from non-resonant scattering. In
particular, we show that the detuning dependence of the incoherent scattering
cross-section allows the direct determination of the BEC pairing density $<
\psi \psi >$, which is a broken symmetry and provides evidence that the
condensate is not in a good number state.",9707321v1
1997-08-22,Resonance in a Tomonaga-Luttinger liquid,"We study a homogeneous Tomonaga-Luttinger liquid with backscattering
potential. A perturbative computation of the conductance at and near resonance
is given. We find that the backscattering of one electron dominates that of two
electrons for an interaction parameter $K\geq 1/3$ and that the resonance point
depends on temperature. Our results may be relevant for recent experiments on
shot-noise in FQHE, where the charge 1/3 and not $2*1/3$ is measured on
resonance.",9708179v2
1998-03-10,The Effect of Resonances on Diffusive Scattering,"The presence of resonances modifies the passage of light or of electrons
through a disordered medium. We generalize random matrix theory to account for
this effect. Using supersymmetry, we calculate analytically the mean density of
states, and the effective Lagrangean of the generating functional for the
two-point function. We show that the diffusion constant scales with the
effective mean level spacing. The latter exhibits a resonance dip. These facts
allow us to interpret experimental results on light scattering for different
concentrations of resonant scatterers.",9803115v1
1999-05-12,Cyclotron Resonance in the Layered Perovskite Superconductor Sr2RuO4,"We have measured the cyclotron masses in Sr2RuO4 through the observation of
periodic-orbit-resonances - a magnetic resonance technique closely related to
cyclotron resonance. We obtain values for the alpha, beta and gamma Fermi
surfaces of (4.33+/-0.05)me, (5.81+/-0.03)me and (9.71+/-0.11)me respectively.
The appreciable differences between these results and those obtained from de
Haas- van Alphen measurements are attributable to strong electron-electron
interactions in this system. Our findings appear to be consistent with
predictions for a strongly interacting Fermi liquid; indeed, semi-quantitative
agreement is obtained for the electron pockets beta and gamma.",9905147v2
1999-06-06,Spatial stochastic resonance in 1D Ising systems,"The 1D Ising model is analytically studied in a spatially periodic and
oscillatory external magnetic field using the transfer-matrix method. For low
enough magnetic field intensities the correlation between the external magnetic
field and the response in magnetization presents a maximum for a given
temperature. The phenomenon can be interpreted as a resonance phenomenon
induced by the stochastic heatbath. This novel ""spatial stochastic resonance""
has a different origin from the classical stochastic resonance phenomenon.",9906084v1
1999-06-20,Tunneling-Assisted Acoustic Plasmon-Quasiparticle Excitation Resonances in Coupled Q1D Electron Gases,"We show that a weak non-resonant tunneling between two quantum wires leads to
splitting of the acoustic plasmon mode at finite wavevector. Two gaps open up
in the dipersion of the acoustic plasmon mode when its frequency is close to
the frequencies of the quasiparticle excitations. In contrast to the Laudau
damping of the collective excitations, these gaps are attributed to tunneling
assisted acoustic plasmon-quasiparticle excitation resonances. We predict that
such a resonance can be observed in inelastic light scattering spectrum.",9906306v1
1999-08-26,Optically Detected Magnetophonon Resonances in Polar Semiconductors,"Magnetophonon resonances are found for $\omega_{c}=\omega_{LO}/N$ with
N=1,2,3 .... in the polaron cyclotron resonance (CR) linewidth and effective
mass of bulk polar semiconductors. The CR mass and the linewidth are obtained
from the full polaron magneto-optical absorption spectrum which are calculated
using the memory function technique. The amplitude of the resonant peak in the
linewidth can be described by an exponential law at low temperature.",9908375v1
2000-05-03,Macroscopic resonant tunneling of magnetic flux,"We have developed a quantitative theory of resonant tunneling of magnetic
flux between discrete macroscopically distinct quantum states in SQUID systems.
The theory is based on the standard density-matrix approach. Its new elements
include the discussion of the two different relaxation mechanisms that exist
for the double-well potential, and description of the ``photon-assisted''
tunneling driven by external rf radiation. It is shown that in the case of
coherent flux dynamics, rf radiation should lead to splitting of the peaks of
resonant flux tunneling, indicating that the resonant tunneling is a convenient
tool for studying macroscopic quantum coherence of flux.",0005081v1
2000-05-18,Edge and bulk effects in the Terahertz-photoconductivity of an antidot superlattice,"We investigate the Terahertz(THz)-response of a square antidot superlattice
by means of photoconductivity measurements using a
Fourier-transform-spectrometer. We detect, spectrally resolved, the cyclotron
resonance and the fundamental magnetoplasmon mode of the periodic superlattice.
In the dissipative transport regime both resonances are observed in the
photoresponse. In the adiabatic transport regime, at integer filling factor
$\nu =2$, only the cyclotron resonance is observed. From this we infer that
different mechanisms contribute to converting the absorption of THz-radiation
into photoconductivity in the cyclotron and in the magnetoplasmon resonances,
respectively.",0005293v1
2000-12-06,Dispersion of the neutron resonance in cuprate superconductors,"We argue that recently measured downward dispersion of the neutron resonance
peak in cuprate superconductors is naturally explained if the resonance is
viewed as a spin-1 collective mode in a d-wave superconductor. The reduction of
the resonant frequency away from the antiferromagnetic wave vector is a direct
consequence of the momentum dependence of the d-wave superconducting gap. When
the magnetic correlation length becomes large, the dispersion should become
magnon-like, i.e., curve upwards from (pi,pi).",0012065v2
2000-12-11,Stochastic resonance in a suspension of magnetic dipoles under shear flow,"We show that a magnetic dipole in a shear flow under the action of an
oscillating magnetic field displays stochastic resonance in the linear response
regime. To this end, we compute the classical quantifiers of stochastic
resonance, i.e. the signal to noise ratio, the escape time distribution, and
the mean first passage time. We also discuss limitations and role of the linear
response theory in its applications to the theory of stochastic resonance.",0012170v1
2000-12-15,Conductance and density of states as the Kramers-Kronig dispersion relation,"By applying the Kramers-Kronig dispersion relation to the transmission
amplitude a direct connection of the conductance with the density of states is
given in quantum scattering systems connected to two one-channel leads.
  Using this method we show that in the Fano resonance the peak position of the
density of states is generally different from the position of the corresponding
conductance peak, whereas in the Breit-Wigner resonance those peak positions
coincide.
  The lineshapes of the density of states are well described by a Lorentz type
in the both resonances.
  These results are verified by another approach using a specific form of the
scattering matrix to describe scattering resonances.",0012282v1
2001-02-09,Tuning a Resonance in the Fock Space: Optimization of Phonon Emission in a Resonant Tunneling Device,"Phonon-assisted tunneling in a double barrier resonant tunneling device can
be seen as a resonance in the electron-phonon Fock space which is tuned by the
applied voltage. We show that the geometrical parameters can induce a symmetry
condition in this space that can strongly enhance the emission of longitudinal
optical phonons. For devices with thin emitter barriers this is achieved by a
wider collector's barrier.",0102173v3
2001-03-01,Stochastic resonance induced by random fields in ferroelectrics,"We propose a mechanism of stochastic resonance induced by spatial noise
(electric random fields) in ferroelectrics. The calculations demonstrate the
characteristic of the stochastic resonance: certain random field can increase
the susceptibility, the phonon occupancy, and the overcooled temperature. This
mechanics of stochastic resonance may be general in other disordered systems.",0103003v1
2001-03-09,Resonant Andreev reflections in superconductor-carbon-nanotube devices,"Resonant Andreev reflection through superconductor-carbon-nanotube devices
was investigated theoretically with a focus on the superconducting proximity
effect. Consistent with a recent experiment, we find that for high transparency
devices on-resonance, the Andreev current is characterized by a large value and
a resistance dip; low-transparency off-resonance devices give the opposite
result. We also give evidence that the observed low-temperature transport
anomaly may be a natural result of Andreev reflection process.",0103210v1
2001-04-16,Enhancement of Nuclear Spin Superradiance by Electron Resonator,"Superradiance of nuclear spins is considered, when the nuclei interact via
hyperfine forces with electrons of a ferromagnet. The consideration is based on
a microscopic model. If the sample, coupled with a resonant electric circuit,
possesses electronic magnetization, then the electron subsystem plays the role
of an additional effective resonator, by enhancing the coupling between nuclear
spins and the resonant circuit. Radiation power can be increased by three
orders, while the radiation time of a superradiance burst can become three
times shorter. In the presence of dynamic nuclear polarization, the regime of
pulsing superradiance can occur.",0104276v1
2001-05-11,"Breathers in a single plaquette of Josephson junctions: existence, stability and resonances","We present a theoretical study of inhomogeneous dynamic (resistive) states in
a single plaquette consisting of three Josephson junctions. These breather
states are found to exist in a large range of control parameters (dc bias,
anisotropy and self inductance). We perform an analytical analysis of these
states, and their stability and resonance behaviour. Numerical calculations
confirm our results and show that instabilities arise due to resonant
interactions between the breather and electromagnetic oscillations mediated by
the breather state. These instabilities manifest themselves by various
nonlinearities, resonant steps and voltage jumps in the current-voltage
characteristics.",0105237v1
2001-06-18,Resonant Raman Scattering of Interacting Two-Channel Quantum Wires,"Resonant Raman scattering of degenerate interacting two-channel quantum wire
is studied. {\it All} collective excitations of two-channel quantum wire are
shown to give rise to peaks in the polarized Raman spectra near resonance. If
there exist certain symmetries among interactions, a resonant peak can also
appear in the {\it depolarized} Raman spectra, in constrast to the
single-channel case studied by Sassetti and Kramer. We also calculate the
explicit form of the scattering cross-section away from the peaks. The above
features may be experimentally verified in armchair carbon nanotube systems.",0106336v1
2001-06-18,Dynamic instability in resonant tunneling,"We show that an instability may be present in resonant tunneling through a
quantum well in one, two and three dimensions, when the resonance lies near the
emitter Fermi level. A simple semiclassical model which simulates the resonance
and the projected density of states by a nonlinear conductor, the Coulomb
barrier by a capacitance, and the time evolution by an iterated map, is used.
The model reproduces the observed hysteresis in such devices, and exhibits a
series of bifurcations leading to fast chaotic current fluctuations.",0106358v1
2001-06-26,Resonant peak splitting for ballistic conductance in magnetic superlattices,"We investigate theoretically the resonant splitting of ballistic conductance
peaks in magnetic superlattices. It is found that, for magnetic superlattices
with periodically arranged $n$ identical magnetic-barriers, there exists a
general $(n-1)$-fold resonant peak splitting rule for ballistic conductance,
which is the analogy of the $(n-1)$-fold resonant splitting for transmission in
$n$-barrier electric superlattices (R. Tsu and L. Esaki, Appl. Phys. Lett. {\bf
22}, 562 (1973)).",0106537v1
2001-07-23,Experimental Observation of Coherence and Stochastic Resonances in an Electronic Chua Circuit,"Stochastic and coherence resonances appear in nonlinear systems subjected to
an external source of noise and are characterized by a maximum response at the
optimal value of the noise intensity. This paper shows experimentally that it
is possible to observe them in a chaotic system. To this end we have analysed
an electronic Chua circuit running in the chaotic regime and added noise to its
dynamics. In the case of coherence resonance, we observe an optimal periodicity
for the jumps between chaotic attractors, whereas in the case of stochastic
resonance we observe a maximum in the signal-to-noise ratio at the frequency of
an external sinusoidal perturbation.",0107468v1
2001-08-13,Photon Localization in Resonant Media,"We report measurements of microwave transmission over the first five Mie
resonances of alumina spheres randomly positioned in a waveguide. Though
precipitous drops in transmission and sharp peaks in the photon transit time
are found near all resonances, measurements of transmission fluctuations show
that localization occurs only in a narrow frequency window above the first
resonance. There the drop in the photon density of states is found to be more
pronounced than the fall in the photon transit time, leading to a minimum in
the Thouless number.",0108205v1
2001-09-02,Resonant excitation and anti-Stokes luminescence of GaAs single quantum dots,"We have investigated micro-photoluminescence ($\mu$-PL) and excitation
($\mu$-PLE) spectra of a single GaAs/AlGaAs quantum dot grown on a GaAs (411)A
surface. We observed sharp resonant lines in both $\mu$-PL and $\mu$-PLE
spectra, corresponding to the discrete energy levels of the dot. When the
sample was excited at one of the resonant lines, resonant luminescence lines
appear not only in Stokes side but also in anti-Stokes side. We discuss the
possible origins of the anomalus anti-Stokes luminescence.",0109012v1
2001-11-03,Random Resonators and Prelocalized Modes in Disordered Dielectric Films,"Areal density of disorder-induced resonators with a high quality factor,
$Q\gg 1$, in a film with fluctuating refraction index is calculated
theoretically. We demonstrate that for a given $kl>1$, where $k$ is the light
wave vector, and $l$ is the transport mean free path, when {\em on average} the
light propagation is diffusive, the likelihood for finding a random resonator
increases dramatically with increasing the correlation radius of the disorder.
Parameters of {\em most probable} resonators as functions of $Q$ and $kl$ are
found.",0111047v1
2001-12-18,System size resonance in coupled noisy systems and in the Ising model,"We consider an ensemble of coupled nonlinear noisy oscillators demonstrating
in the thermodynamic limit an Ising-type transition. In the ordered phase and
for finite ensembles stochastic flips of the mean field are observed with the
rate depending on the ensemble size. When a small periodic force acts on the
ensemble, the linear response of the system has a maximum at a certain system
size, similar to the stochastic resonance phenomenon. We demonstrate this
effect of system size resonance for different types of noisy oscillators and
for different ensembles -- lattices with nearest neighbors coupling and
globally coupled populations. The Ising model is also shown to demonstrate the
system size resonance.",0112338v1
2001-12-20,Entanglement and decoherence of a micromechanical resonator via coupling to a Cooper box,"We analyse the quantum dynamics of a micromechanical resonator capacitively
coupled to a Cooper box. With appropriate quantum state control of the Cooper
box, the resonator can be driven into a superposition of spatially separated
states. The Cooper box can also be used to probe the environmentally-induced
decoherence of the resonator superposition state.",0112403v1
2002-04-10,Time-resolved impulse response of the magnetoplasmon resonance in a two-dimensional electron gas,"We have used optically excited ultrashort electrical pulses to measure the
magnetoplasmon resonance of a two-dimensional electron gas formed in an
AlGaAs/GaAs heterostructure at frequencies up to 200 gigahertz. This is
accomplished by incorporating the sample into a guided wave probe operating in
a pumped (^{3}He) system. We are able to detect the resonance by launching a
stimulus pulse in the guide, and monitoring the system response in a time
resolved pump-probe arrangement. Data obtained from measurements yield resonant
frequencies that agree with the magnetoplasmon dispersion relation.",0204229v1
2002-06-05,Coherent coupling dynamics in a quantum dot microdisk laser,"Luminescence intensity autocorrelation (LIA) is employed to investigate
coupling dynamics between (In,Ga)As QDs and a high-Q (~7000) resonator with
ultrafast time resolution (150 fs), below and above the lasing threshold at T =
5 K. For QDs resonant and non-resonant with the cavity we observe both a
six-fold enhancement and a 0.77 times reduction of the spontaneous emission
rate, respectively. In addition, LIA spectroscopy reveals the onset of coherent
coupling at the lasing threshold through qualitative changes in the dynamic
behavior and a tripling of the resonant QD emission rate.",0206065v1
2002-07-19,Cyclotron Resonance of Itinerant Holes in Ferromagnetic InMnAs/GaSb Heterostructures,"We report the first observation of hole cyclotron resonance (CR) in
ferromagnetic InMnAs/GaSb heterostructures both in the high-temperature
paramagnetic phase and the low-temperature ferromagnetic phase. We clearly
resolve two resonances that exhibit strong temperature dependence in position,
linewidth, and intensity. We attribute the two resonances to the so-called
fundamental CR transitions expected for delocalized holes in the valence band
in the magnetic quantum limit, demonstrating the existence of $p$-like
itinerant holes that are describable within the Luttinger-Kohn effective mass
theory.",0207485v1
2002-10-23,Directional Emission from Microlasers with Open Chaotic Resonators,"Using topological classical considerations (Poincar\`{e} Maps) the appearance
of ``bow-tie''-shaped resonances is predicted for certain types of waveguides.
The geometry of such waveguides is chosen to yield mixed chaotic dymnamics.
Then, based on resonance effects, we propose the construction of directional
emission microlasers using {\it open} chaotic semiconductor resonators of high
refractive index.",0210532v1
2002-11-20,Ugo Fano and Shape Resonances,"Ugo Fano has been a leader in theoretical Physics in the XX century giving
key contributions to our understanding of quantum phenomena. He passed away on
13 February 2001 after 67 years of research activity. I will focus on his
prediction of the quantum interference effects to understand the high-energy
photoabsorption cross section giving the Fano lineshapes. The Fano results led
to the theoretical understanding of shape resonances (known also as Feshbach
resonances) that should be better called Fano resonances. Finally I will show
that today this Fano quantum interference effect is behind several new physical
phenomena in different fields.",0211452v2
2003-02-03,Dc-Driven Diatomic Frenkel-Kontorova Model,"We investigate the resonance steps, spatiotemporal dynamics, and dynamical
phase diagrams of the dc-driven diatomic Frenkel-Kontorova model. The complete
resonance velocity spectrum is given. The diatomic effects result in each
resonant state being characterized by two integer pairs, $(k_1,k_2)$ and
$(k_1,k_2^{\prime})$. In the high-velocity region the linear response of the
average velocity, $v$, of the chain to the driving force $F$ is often
punctuated by subharmonic resonances $(k_1>k_2)$. There are two kinds of
nonlinear response regions in the high-velocity region. A new physical
interpretation of the mean-field treatment is presented.",0302056v1
2003-02-19,Experimental study of high frequency stochastic resonance in Chua circuits,"We study the stochastic resonance phenomenon occurring in electronic Chua
circuits operating in the chaotic regime when the forcing signal is modulated
at relatively high frequency, of the order of magnitude of the main Chua
frequency in the absence of forcing ($f_o$). In all the cases, a clear maximum
in the signal-to-noise ratio for an intermediate noise level is observed. When
modulating with a frequency smaller than $f_o$ we also observe a resonance at a
harmonic of the external frequency which is closer to $f_o$ or to one of its
harmonic. If the modulating frequency is larger than $f_o$ we only observe the
resonance at the modulating frequency.",0302379v1
2003-03-05,Measurement of interaction energy near a Feshbach resonance in a 6Li Fermi gas,"We investigate the strongly interacting regime in an optically trapped $^6$Li
Fermi mixture near a Feshbach resonance. The resonance is found at $800(40) $G
in good agreement with theory. Anisotropic expansion of the gas is interpreted
by collisional hydrodynamics. We observe an unexpected and large shift ($80 $G)
between the resonance peak and both the maximum of atom loss and the change of
sign of the interaction energy.",0303079v1
2003-03-10,Energy Spectra of Magnetostatic Oscillations in Ferrite Disk Resonators,"Ferromagnetic resonators with short-wavelength, so-called magnetostatic (MS),
oscillations can be considered in microwaves as point (with respect to the
external electromagnetic fields) particles. It was shown recently [E. O.
Kamenetskii, Phys. Rev. E, 63, 066612 (2001)] that MS oscillations in a small
ferrite disk resonator can be characterized by a discrete spectrum of energy
levels. This fact allows analyzing the MS oscillations similarly to quantum
mechanical problems. In this paper we give the results of energy spectrum
calculations for MS oscillations in a ferrite disk resonator.",0303164v2
2003-03-14,Effects of impurity scattering on electron-phonon resonances in semiconductor superlattice high-field transport,"A non-equilibrium Green's function method is applied to model high-field
quantum transport and electron-phonon resonances in semiconductor
superlattices. The field-dependent density of states for elastic (impurity)
scattering is found non-perturbatively in an approach which can be applied to
both high and low electric fields. I-V curves, and specifically electron-phonon
resonances, are calculated by treating the inelastic (LO phonon) scattering
perturbatively. Calculations show how strong impurity scattering suppresses the
electron-phonon resonance peaks in I-V curves, and their detailed sensitivity
to the size, strength and concentration of impurities.",0303282v1
2003-03-17,Fano resonance in crossed carbon nanotubes,"We report the observation of the resonant transport in multiwall carbon
nanotubes in a crossed geometry. The resonant transport is manifested by an
asymmetric peak in the differential conductance curve. The observed asymmetric
conductance peak is well explained by Fano resonance originating from the
scattering at the contact region of the two nanotubes. The conductance peak
depends sensitively on the external magnetic field and exhibits
Aharonov-Bohm-type oscillation.",0303300v1
2003-05-19,Frequency resonance in Josephson-junction arrays under strong driving,"We study resonance behavior of a two-dimensional fully frustrated
Josephson-junction array driven by high alternating currents. The
signal-to-noise ratio (SNR) is examined as the frequency of the driving current
is varied; revealed is a certain frequency range where the SNR is enhanced.
Such resonance behavior is explained by considering the dynamic order parameter
at zero temperature. We also compute the work, which corresponds to the Ohmic
dissipation of the energy due to external currents, and discuss its possibility
as a measure of stochastic resonance.",0305426v1
2003-09-12,Measurement of a Mixed Spin Channel Feshbach Resonance in Rubidium 87,"We report on the observation of a mixed spin channel Feshbach resonance at
the low magnetic field value of (9.09 +/- 0.01) G for a mixture of |2,-1> and
|1,+1> states in 87Rb. This mixture is important for applications of
multi-component BECs of 87Rb, e.g. in spin mixture physics and for quantum
entanglement. Values for position, height and width of the resonance are
reported and compared to a recent theoretical calculation of this resonance.",0309318v3
2003-10-18,The Zinc Doping Induced STM Resonance as a Zero Mode,"We show that the Zinc doping induced STM resonance in high-Tc cuprates is a
zero mode - a d-wave monomer confined in the opposite sublattice of the Zinc
site. We propose that the resonance come from the superconducting peak around
$(\pi,0) $ as observed in ARPES experiments. It is predicted that the resonance
should vanish in single layer $BSCCO_{2201}$ or in the vortex core of
underdoped cuprate where the ARPES peak is absent. We argue that the STM result
imply the ARPES peak around $(\pi,0) $ is the only coherent feature in the
whole Brillouin zone.",0310439v1
2003-11-04,Resonant Enhancement of Inelastic Light Scattering in Strongly Correlated Materials,"We use dynamical mean field theory to find an exact solution for inelastic
light scattering in strongly correlated materials such as those near a
quantum-critical metal-insulator transition. We evaluate the results for
$\textbf{q}=0$ (Raman) scattering and find that resonant effects can be quite
large, and yield a triple resonance, a significant enhancement of nonresonant
scattering peaks, a joint resonance of both peaks when the incident photon
frequency is on the order of $U$, and the appearance of an isosbestic point in
all symmetry channels for an intermediate range of incident photon frequencies.",0311070v1
2003-12-24,Observation of Conduction Band Satellite of Ni Metal by 3p-3d Resonant Inverse Photoemission Study,"Resonant inverse photoemission spectra of Ni metal have been obtained across
the Ni 3$p$ absorption edge. The intensity of Ni 3$d$ band just above Fermi
edge shows asymmetric Fano-like resonance. Satellite structures are found at
about 2.5 and 4.2 eV above Fermi edge, which show resonant enhancement at the
absorption edge. The satellite structures are due to a many-body configuration
interaction and confirms the existence of 3$d^8$ configuration in the ground
state of Ni metal.",0312628v3
2004-01-14,The spin resonance and high frequency optical properties of the cuprates,"We argue that recently observed superconductivity-induced blue shift of the
plasma frequency $\delta \omega_{pl}$ in $Bi_2Sr_2CaCu_2O_{8+\delta}$ is
related to the change in the integrated dynamical structure factor associated
with the development of the spin resonance below $T_c$. We show that the
magnitude of $\delta \omega_{pl}$ is consistent with the small integrated
spectral weight of the resonance, and its temperature dependences closely
follow that of the spin resonance peak.",0401241v1
2004-01-18,Resonant thermal transport in semiconductor barrier structures,"I report that thermal single-barrier (TSB) and thermal double-barrier (TDB)
structures (formed, for example, by inserting one or two regions of a few Ge
monolayers in Si) provide both a suppression of the phonon transport as well as
a resonant-thermal-transport effect. I show that high-frequency phonons can
experience a traditional double-barrier resonant tunneling in the TDB
structures while the formation of Fabry-Perot resonances (at lower frequencies)
causes quantum oscillations in the temperature variation of both the TSB and
TDB thermal conductances $\sigma_{\text{TSB}}$ and $\sigma_{\text{TDB}}$.",0401315v1
2004-02-05,"Three kinds of compact thin subwavelength cavity resonators containing left-handed media: rectangular, cylindrical, spherical","In the present paper we investigate the restriction conditions for three
kinds of cavity resonators ({\it i.e.}, the rectangular, cylindrical, spherical
resonators). It is shown that the layer of materials with negative optical
refractive indices can act as a phase compensator/conjugator, and thus by
combining such a layer with another layer made of the regular medium one can
obtain a so-called compact thin subwavelength cavity resonator.",0402164v1
2004-03-30,Time-dependent resonant tunneling for a parallel-coupled double quantum dots,"We derive the quantum rate equations for an Aharonov-Bohm interferometer with
two vertically coupled quantum dots embedded in each of two arms by means of
the nonequilibrium Green's function in the sequential tunneling regime. Basing
on these equations, we investigate time-dependent resonant tunneling under a
small amplitude irradiation and find that the resonant photon-assisted
tunneling peaks in photocurrent demonstrate a combination behavior of Fano and
Lorentzian resonances due to the interference effect between the two pathways
in this parallel configuration, which is controllable by threading the magnetic
flux inside this device.",0403741v1
2004-04-22,Cyclotron resonance in the quasi-1D organic superconductor (TMTSF)2ClO4,"We report the observation of cyclotron resonance (CR) in a metal possessing
pure quasi-one-dimensional Fermiology - namely, the organic linear-chain
compound (TMTSF)2ClO4, whose Fermi surface consists of a pair of weakly warped
sheets. The CR phenomenon is related to weak inter-chain coupling, which allows
electrons constrained on open trajectories to acquire small transverse
velocities. Application of an appropriately oriented magnetic field induces
periodic motion transverse to the chain direction and, hence, to a resonance in
the AC conductivity. The field orientation dependence of the resonance is
related simply to the Fermi velocity and lattice periodicity.",0404545v2
2004-06-02,Observation of single defect relaxation in a freely suspended nano resonator,"Relaxation of single defects in a nanometer sized resonator is observed by
coupling surface acoustic waves to a freely suspended beam. The surface waves
act on the resonator as driving forces being able to modify the internal
friction in the beam. In analogy to classical experiments on internal friction
in macroscopic samples, we perform frequency, amplitude, and temperature
dependent experiments on the nano resonator and find a scenario which is
consistent with the observation of single defect relaxation.",0406056v1
2004-06-04,Observation of a New Fluxon Resonant Mechanism in Annular Josephson Tunnel Structures,"A novel dynamical state has been observed in the dynamics of a perdurbed
sine-Gordon system. This resonant state, has been experimentally observed as a
singularity in the dc current voltage characteristic of an annular Josephson
tunnel junction, excited in the presence of a magnetic field. With this
respect, it can be assimilated to self-resonances known as Fiske steps.
Differently from these, however, we demonstrate, on the basis of numerical
simulations, that its detailed dynamics involves rotating fluxon pairs, a
mechanism associated, so far, to self-resonances known as zero-field steps.",0406104v1
2004-06-25,Impurity effects on the resonant Andreev reflection in a finite-sized carbon nanotube system,"The influence of the impurity on the resonant Andreev reflection through a
normal-metal/carbon-nanotube/superconductor system is studied theoretically. It
is found that the resonant Andreev reflection depends on the strength of the
impurity and the length of the armchair nanotube. The impurity which breaks the
electron-hole symmetry of the nanotubes greatly reduces the resonant Andreev
reflection. The symmetry broken depends distinctly on the impurity strength.
The impurity effects on the Andreev reflection current at different bias are
also studied.",0406633v1
2004-06-29,Formation of fermionic molecules via interisotope Feshbach resonances,"We perform an analysis of recent experimental measurements and improve the
lithium interaction potentials. For $^6$Li a consistent description can be
given. We discuss theoretical uncertainties for the position of the wide $^6$Li
Feshbach resonance, and we present an analytic scattering model for this
resonance, based on the inclusion of a field-dependent virtual open-channel
state. We predict new Feshbach resonances for the $^6$Li-$^7$Li system, and
their importance for different types of crossover superfluidity models is
discussed.",0406722v2
2004-07-14,Electric coupling to the magnetic resonance of split ring resonators,"We study both theoretically and experimentally the transmission properties of
a lattice of split ring resonators (SRRs) for different electromagnetic (EM)
field polarizations and propagation directions. We find unexpectedly that the
incident electric field E couples to the magnetic resonance of the SRR when the
EM waves propagate perpendicular to the SRR plane and the incident E is
parallel to the gap-bearing sides of the SRR. This is manifested by a dip in
the transmission spectrum. A simple analytic model is introduced to explain
this interesting behavior.",0407369v1
2004-07-28,Macroscopic quantum effects in a strongly driven nanomechanical resonator,"We investigate the nonlinear response of a vibrating suspended nanomechanical
beam on external periodic driving. The amplitude of the fundamental transverse
mode behaves thereby like a weakly damped quantum particle in a driven
anharmonic potential. Upon using a Born-Markovian master equation, we calculate
the fundamental mode amplitude for varying driving frequencies. In the
nonlinear regime, we observe resonances which are absent in the corresponding
classical model. They are shown to be associated with resonant multi-phonon
excitations.
  Furthermore, we identify resonant tunneling in a dynamically induced bistable
effective potential.",0407720v2
2004-10-20,BCS-BEC crossover in a gas of Fermi atoms with a p-wave Feshbach resonance,"We investigate unconventional superfluidity in a gas of Fermi atoms with an
anisotropic p-wave Feshbach resonance. Including the p-wave Feshbach resonance
as well as the associated three kinds of quasi-molecules with finite orbital
angular momenta $L_z=\pm1,0$, we calculate the transition temperature of the
superfluid phase. As one passes through the p-wave Feshbach resonance, we find
the usual BCS-BEC crossover phenomenon. The p-wave BCS state continuously
changes into the BEC of bound molecules with L=1. Our calculation includes the
effect of fluctuations associated with Cooper-pairs and molecules which are not
Bose-condensed.",0410516v1
2004-11-10,Observation of Feshbach-like resonances in collisions between ultracold molecules,"We observe magnetically tuned collision resonances for ultracold Cs2
molecules stored in a CO2-laser trap. By magnetically levitating the molecules
against gravity, we precisely measure their magnetic moment. We find an avoided
level crossing which allows us to transfer the molecules into another state. In
the new state, two Feshbach-like collision resonances show up as strong
inelastic loss features. We interpret these resonances as being induced by Cs4
bound states near the molecular scattering continuum. The tunability of the
interactions between molecules opens up novel applications such as controlled
chemical reactions and synthesis of ultracold complex molecules.",0411258v1
2005-02-08,Suppression of inelastic bound state resonance effects by the dimensionality of atom-surface scattering event,"We develop a multidimensional coupled channel method suitable for studying
the interplay of bound state resonance and phonon assisted scattering of inert
gas atoms from solid surfaces in one, two and three dimensions. This enables us
to get insight into the features that depend on the dimensionality of inelastic
resonant processes typically encountered in low energy He atom scattering from
surfaces, in general, and to elaborate on the observability of recently
conjectured near threshold resonances in scattering from Einstein phonons, in
particular.",0502198v1
2005-02-18,Resonances in Ferromagnetic Gratings Detected by Microwave Photoconductivity,"We investigate the impact of microwave excited spin excitations on the DC
charge transport in a ferromagnetic (FM) grating. We observe both resonant and
nonresonant microwave photoresistance. Resonant features are identified as the
ferromagnetic resonance (FMR) and ferromagnetic antiresonance (FMAR). A
macroscopic model based on Maxwell and Landau-Lifschitz equations reveals the
macroscopic nature of the FMAR. The experimental approach and results provide
new insight in the interplay between photonic, spintronic, and charge effects
in FM microstructures.",0502442v1
2005-03-04,Sharp bends in photonic crystal waveguides as nonlinear Fano resonators,"We demonstrate that high transmission through sharp bends in photonic crystal
waveguides can be described by a simple model of the Fano resonance where the
waveguide bend plays a role of a specific localized defect. We derive effective
discrete equations for two types of the waveguide bends in two-dimensional
photonic crystals and obtain exact analytical solutions for the resonant
transmission and reflection. This approach allows us to get a deeper insight
into the physics of resonant transmission, and it is also useful for the study
and design of power-dependent transmission through the waveguide bends with
embedded nonlinear defects.",0503100v1
2005-03-09,Theoretical Study of Fano Resonance in Single-Walled Carbon Nanotubes,"Electrical transport through single-walled carbon nanotubes (SWNTs) is
investigated by using the nearest-neighbor tight-binding model coupled with two
electron reservoirs. When the SWNT-electrode coupling is not axially symmetric,
asymmetric resonance peaks are found in the conductance and are considered to
be due to the interference between two transport channels. These Fano
resonances are sensitive to the coupling with electrodes. When the coupling is
axially symmetric, no asymmetric resonance peaks are observed.",0503200v1
2005-03-17,Raman resonance in spin S two-leg ladder systems,"We argue that the Raman intensity in a spin S two-leg spin-ladder has a
pseudo-resonance peak, whose width is very small at large S. The
pseudo-resonance originates from the existence of a local minimum in the magnon
excitation spectrum, and is located slightly below twice the magnon energy at
the minimum. The physics behind the peak is similar to the excitonic scenario
for the neutron and Raman resonances in a d-wave superconductor.",0503453v1
2005-04-02,Importance of individual scattering matrix elements at Fano resonances,"Single particle resonances in quantum wires are generally Fano resonances. In
case of Fano resonances, the scattering phase shift in some channels show sharp
phase drops and that in the other channels do not. Phase shift in a particular
channel can be measured and can yield information about the integrated charge
localized around the scatterer. This paper tries to analyze if some channels
are more informative than the others, so that an experimentalist can measure
the phase shift in only those channels.",0504050v1
2005-05-02,Engineering Fano resonances in discrete networks,"We study transmission properties of discrete networks composed of linear
arrays coupled to systems of N side defects, and demonstrate the basic
principles of the resonant scattering management through engineering Fano
resonances. We find exact solutions for the wave transmission coefficient and
reveal the conditions for the perfect reflections and transmissions due to
either destructive or constructive interferences. We associate these
reflections and transmissions with Fano resonances, and demonstrate how they
can be tuned by introducing nonlinear defects into the network.",0505023v2
2005-05-18,Modeling interactions for resonant p-wave scattering,"In view of recent experiments on ultra-cold polarized fermions, the
zero-range potential approach is generalized to situations where two-body
scattering is resonant in the p-wave channel. We introduce a modified scalar
product which reveals a deep relation between the geometry of the Hilbert space
and the interaction. This formulation is used to obtain a simple interpretation
for the transfer rates between atomic and molecular states within a two
branches picture of the many-body system close to resonance. At resonance, the
energy of the dilute gas is found to vary linearly with density.",0505448v3
2005-05-23,Ultracold Molecule Production Via a Resonant Oscillating Magnetic Field,"A novel atom-molecule conversion technique has been investigated. Ultracold
85Rb atoms sitting in a DC magnetic field near the 155G Feshbach resonance are
associated by applying a small sinusoidal oscillation to the magnetic field.
There is resonant atom to molecule conversion when the modulation frequency
closely matches the molecular binding energy. We observe that the atom to
molecule conversion efficiency depends strongly on the frequency, amplitude,
and duration of the applied modulation and on the initial phase space density
of the sample. This technique offers high conversion efficiencies without the
necessity of crossing or closely approaching the Feshbach resonance and allows
precise spectroscopic measurements.",0505567v1
2005-06-22,Site and lattice resonances in metallic hole arrays,"A powerful analytical approach is followed to study light transmission
through subwavelength holes drilled in thick perfect-conductor films, showing
that full transmission (100%) is attainable in arrays of arbitrarily narrow
holes as compared to the film thickness. The interplay between resonances
localized in individual holes and lattice resonances originating in the array
periodicity reveals new mechanisms of transmission enhancement and suppression.
In particular, localized resonances obtained by filling the holes with
high-index-of-refraction material are examined and experimentally observed
through large enhancement in the transmission of individual holes.",0506564v1
2005-07-03,Intermodulation Gain in Nonlinear NbN Superconducting Microwave Resonators,"We report the measurement of intermodulation gain in NbN superconducting
stripline resonators. In the intermodulation measurements we inject two unequal
tones into the oscillator, the pump and signal, both lying within the resonance
band. At the onset of instability of the reflected pump we obtain a
simultaneous gain of both the idler and the reflected signal. The measured gain
in both cases can be as high as 15 dB, whereas to the best of our knowledge
intermodulation gain greater than unity in superconducting resonators has not
been reported before in the scientific literature.",0507056v1
2005-07-12,Tamm surface resonances in very low energy electron scattering from clean metal surfaces,"Very low-energy features which occur in electron reflectivities from clean
fcc metal (111) surfaces have been subject to a number of interpretations. Here
we analyse the feature near 19.8 eV on Cu(111) at normal incidence and find
that it is due to resonant scattering at the rise of the muffin-tin average
interstitial potential between atomic layers on approach to the surface from
the bulk. This new mechanism corresponds to a Tamm-type surface resonance which
is very different in formation to the usual Shockley and Rydberg resonances and
explains all features in a systematic way.",0507266v1
2005-08-26,Resonance mode in $B_{1g}$ Raman scattering -- a way to distinguish between spin-fluctuation and phonon-mediated $d-$wave superconductivity,"We argue that Raman scattering in $B_{1g}$ symmetry allows one to distinguish
between phonon-mediated and magnetically-mediated $d-$wave superconductivity.
In spin mediated superconductors, $B_{1g}$ Raman intensity develops a resonance
at a frequency $\omega_{res} < 2\Delta_{max}$, whose origin is similar to a
neutron resonance. In phonon-mediated $d-$wave superconductors, such a
resonance does not develop. Several extensions of the argument are presented.",0508643v2
2005-11-22,Spatial Imaging and Mechanical Control of Spin Coherence in Strained GaAs Epilayers,"The effect of uniaxial tensile strain on spin coherence in n-type GaAs
epilayers is probed using time-resolved Kerr rotation, photoluminescence, and
optically-detected nuclear magnetic resonance spectroscopies. The bandgap,
electron spin lifetime, electron g-factor, and nuclear quadrupole splitting are
simultaneously imaged over millimeter scale areas of the epilayers for
continuously varying values of strain. All-optical nuclear magnetic resonance
techniques allow access to the strain induced nuclear quadrupolar resonance
splitting in field regimes not easily addressable using conventional
optically-detected nuclear magnetic resonance.",0511562v1
2005-11-23,High intermodulation gain in a micromechanical Duffing resonator,"In this work we use a micromechanical resonator to experimentally study small
signal amplification near the onset of Duffing bistability. The device consists
of a PdAu beam serving as a micromechanical resonator excited by an adjacent
gate electrode. A large pump signal drives the resonator near the onset of
bistability, enabling amplification of small signals in a narrow bandwidth. To
first order, the amplification is inversely proportional to the frequency
difference between the pump and signal. We estimate the gain to be about 15dB
for our device.",0511587v1
2005-12-21,Confined optical phonon modes in polar tetrapod nanocrystals detected by resonant inelastic light scattering,"We investigated CdTe nanocrystal tetrapods of different sizes by resonant
inelastic light scattering at room temperature and under cryogenic conditions.
We observe a strongly resonant behavior of the phonon scattering with the
excitonic structure of the tetrapods. Under resonant conditions we detect a set
of phonon modes that can be understood as confined longitudinal-optical
phonons, surface-optical phonons, and transverse-optical phonons in a nanowire
picture.",0512541v1
2006-01-08,Resonant control of spin dynamics in ultracold quantum gases by microwave dressing,"We study experimentally interaction-driven spin oscillations in optical
lattices in the presence of an off-resonant microwave field. We show that the
energy shift induced by this microwave field can be used to control the spin
oscillations by tuning the system either into resonance to achieve near-unity
contrast or far away from resonance to suppress the oscillations. Finally, we
propose a scheme based on this technique to create a flat sample with either
singly- or doubly-occupied sites, starting from an inhomogeneous Mott
insulator, where singly- and doubly-occupied sites coexist.",0601151v1
2006-02-02,Design of Q-Band loop-gap resonators at frequencies 34-36 GHz for single electron spin spectroscopy in semiconductor nanostructures,"We report on the design of loop-gap resonators (LGR) operating in the
frequency range 34-36 GHz with the goal to achieve single electron spin
resonance (ESR) in quantum dot nanostructures. We present a comprehensive study
of the magnetic field strength and the spatial distribution of the electric and
magnetic fields in the resonator by means of experiments and numerical
simulations.",0602058v1
2006-03-24,Magnetic resonance in a pyrochlore antiferromagnet Gd2Ti2O7,"Electron spin resonance study of frustrated pyrochlore Gd2Ti2O7 is performed
in a wide frequency band for a temperature range 0.4-30 K, which covers
paramagnetic and magnetically ordered phases. The paramagnetic resonance
reveals the spectroscopic g-factor about 2.0 and a temperature dependent
linewidth. In ordered phases magnetic resonance spectra are distinctive for a
nonplanar cubic (or tetrahedral) antiferromagnet with an isotropic
susceptibility. In the high-field saturated phase, weakly-dispersive soft modes
are observed and their field evolution is traced.",0603653v1
2006-04-05,Current-driven resonant excitation of magnetic vortex,"A magnetic vortex core in a ferromagnetic circular nanodot has a resonance
frequency originating from the confinement of the vortex core. By the
micromagnetic simulation including the spin-transfer torque, we show that the
vortex core can be resonantly excited by an AC (spin-polarized) current through
the dot and that the resonance frequency can be tuned by the dot shape. The
resistance measurement under the AC current successfully detects the resonance
at the frequency consistent with the simulation.",0604123v1
2006-04-13,Variational computation of a vibrating lithium niobate rectangular plate,"Electrically-excited electroelastic extensional vibrations of an arbitrarily
cut three-dimensional piezocrystal resonator are analyzed variationally. A set
of trigonometric trial functions applicable to a waveguide behavior of the
resonator partly covered by metal electrodes is proposed. The dependence of the
content of the vibration modes sustained by the resonator on the electrode
configuration is found. The frequency spectra taken in 128-Y-rotated lithium
niobate rectangular plates exhibit a good correspondence with the computed
resonator eigenfrequencies.",0604337v1
2006-05-28,Generalized switchable coupling for superconducting qubits using double resonance,"We propose a method for switchable coupling between superconducting qubits
using double resonance. The inter-qubit coupling is achieved by applying
near-resonant oscillating fields to the two qubits. The deviation from
resonance relaxes the criterion of strong driving fields while still allowing
for a fully entangling two-qubit gate. This method avoids some of the
shortcomings of previous proposals for switchable coupling. We discuss the
possible application of our proposal to a pair of inductively coupled flux
qubits, and we consider the extension to phase qubits.",0605685v2
2006-06-12,Resonating bipolarons,"Electrons coupled to local lattice deformations end up in selftrapped
localized molecular states involving their binding into bipolarons when the
coupling is stronger than a certain critical value. Below that value they exist
as essentially itinerant electrons. We propose that the abrupt crossover
between the two regimes can be described by resonant pairing similar to the
Feshbach resonance in binary atomic collision processes. Given the
intrinsically local nature of the exchange of pairs of itinerant electrons and
localized bipolarons, we demonstrate the occurrence of such a resonance on a
finite-size cluster made out of metallic atoms surrounding a polaronic ligand
center.",0606280v1
2006-07-11,Novel Self-Sustained Modulation in Superconducting Stripline Resonators,"We study thermal instability in a driven superconducting NbN resonator
integrated with a microbridge. A monochromatic input drive is injected into the
resonator and the response is measured as a function of the frequency and
amplitude of the drive. Inside a certain zone in the frequency-amplitude plane
the system has no steady state, and consequently self-sustained modulation of
the reflected power off the resonator is generated. A theoretical model,
according to which the instability originates by a hot spot forming in the
microbridge, exhibits a good quantitative agreement with the experimental
results.",0607259v4
2006-07-11,Thermal Instability and Self-Sustained Modulation in Superconducting NbN Stripline Resonators,"We study theoretically and experimentally the response of a microwave
superconducting stripline resonator, integrated with a microbridge, to a
monochromatic injected signal. We find that there is a certain range of driving
parameters, in which a novel nonlinear phenomenon immerges, and self-sustained
modulation of the reflected power off the resonator is generated by the
resonator. A theoretical model which attributes the self modulation to a
thermal instability yields a good agreement with the experimental results.",0607261v2
2006-08-07,Quantum dynamics of a resonator driven by a superconducting single-electron transistor: a solid-state analogue of the micromaser,"We investigate the behavior of a quantum resonator coupled to a
superconducting single-electron transistor tuned to the Josephson quasiparticle
resonance and show that the dynamics is similar in many ways to that found in a
micromaser. Coupling to the SSET can drive the resonator into non-classical
states of self-sustained oscillation via either continuous or discontinuous
transitions. Increasing the coupling further leads to a sequence of transitions
and regions of multistability.",0608166v2
2006-09-18,Evidence of rf-driven branching of dendritic vortex avalanches in MgB2 microwave resonators,"The influence of dendritic magnetic-flux penetration on the microwave
response of superconducting MgB2 films is investigated by a coplanar resonator
technique. The peculiar feature consists of jumps in the resonance curve,
induced by vortex avalanches freezing flux inside the resonator. Due to a
shaking effect, microwave currents maintain the vortex system close to a
nonequilibrium state, resulting in dendrite branching. Avalanche-size
distributions before and after flux-pinning tailoring by heavy-ion irradiation
are fully consistent with molecular dynamics simulations reported in
literature.",0609427v1
2007-01-10,Superlattice Magnetophonon Resonances in Strongly Coupled InAs/GaSb Superlattices,"We report an experimental study of miniband magnetoconduction in
semiconducting InAs/GaSb superlattices. For samples with miniband widths below
the longitudinal optical phonon energy we identify a new superlattice
magnetophonon resonance (SLMPR) caused by resonant scattering of electrons
across the mini-Brillouin zone. This new resonant feature arises directly from
the drift velocity characteristics of the superlattice dispersion and total
magnetic quantisation of the superlattice Landau level minibands.",0701214v2
2007-02-09,Classical to Quantum Transition of a Driven Nonlinear Nanomechanical Resonator,"We seek the first indications that a nanoelectromechanical system (NEMS) is
entering the quantum domain as its mass and temperature are decreased. We find
them by studying the transition from classical to quantum behavior of a driven
nonlinear Duffing resonator. Numerical solutions of the equations of motion,
operating in the bistable regime of the resonator, demonstrate that the quantum
Wigner function gradually deviates from the corresponding classical phase-space
probability density. These clear differences that develop due to nonlinearity
can serve as experimental evidence, in the near future, that NEMS resonators
are entering the quantum domain.",0702255v1
2007-03-22,Resonant tunneling diode with spin polarized injector,"We investigate the current-voltage characteristics of a II-VI semiconductor
resonant-tunneling diode coupled to a diluted magnetic semiconductor injector.
As a result of an external magnetic field, a giant Zeeman splitting develops in
the injector, which modifies the band structure of the device, strongly
affecting the transport properties. We find a large increase in peak amplitude
accompanied by a shift of the resonance to higher voltages with increasing
fields. We discuss a model which shows that the effect arises from a
combination of three-dimensional incident distribution, giant Zeeman spin
splitting and broad resonance linewidth.",0703574v1
1996-12-16,Evolutionary Dynamics While Trapped in Resonance: A Keplerian Binary System Perturbed by Gravitational Radiation,"The method of averaging is used to investigate the phenomenon of capture into
resonance for a model that describes a Keplerian binary system influenced by
radiation damping and external normally incident periodic gravitational
radiation. The dynamical evolution of the binary orbit while trapped in
resonance is elucidated using the second order partially averaged system. This
method provides a theoretical framework that can be used to explain the main
evolutionary dynamics of a physical system that has been trapped in resonance.",9612040v1
1999-09-23,Partial Wave Analysis of $J/ψ\toγ(π^+π^-π^+π^-)$,"BES data on $J/\psi \to \gamma (\pi^{+} \pi^{-} \pi^{+} \pi^{-})$ have been
analyzed into partial waves. We fit with resonances having $J^{PC}=2^{++}$ at
1275 MeV, $0^{++}$ at 1500 MeV, $2^{++}$ at 1565 MeV, $0^{++}$ at 1740 MeV,
$2^{++}$ at 1940 MeV and $0^{++}$ at 2104 MeV, plus a broad $0^-$ component.
The $0^{++}$ resonances decay dominantly to $\sigma\sigma$, while $2^{++}$
resonances in the high mass region decay mainly to $f_2(1270)\sigma$ and
$\sigma\sigma$; $2^{++}$ resonances from the low mass region decay dominantly
to $\rho\rho$.",9909040v2
2000-04-03,Resonance structure of tau->Kpipi decays,"Using a sample of 4.7/fb integrated luminosity accumulated with the CLEO II
detector at the Cornell Electron Storage Ring (CESR), we investigate the mass
spectrum and resonant structure in tau->Kpipi decays. We measure the relative
fractions of K1(1270) and K1(1400) resonances in these decays, as well as the
K1 masses and widths. Our fitted K1 resonances are somewhat broader than
previous hadroproduction measurements, and in agreement with recent LEP results
from tau decay. The larger central value of our measured width supports models
which attribute the small tau->Kpipi branching fraction to larger K1 widths
than are presently tabulated. We also determine the Ka-Kb mixing angle theta_K.",0004002v1
2000-10-16,Light meson and baryon spectroscopy from charm decays in Fermilab E791,"We present results from Fermilab experiment E791. We extracted the fractions
of resonant components in the $\Lambda_c^+\to p K^- \pi^+$ decays, and found a
significant polarization of the $\Lambda_c^+$ using a fully 5-dimensional
resonant analysis. We also did resonant analyses of $D^+$ and $D^+_s$ decays
into $\pi^+\pi^-\pi^+$. We observed an insignificant asymmetry in the Breit
Wigner describing the $f_0(980)$ and found good evidence for a light and broad
scalar resonance in the $D^+$ decays.",0010038v1
2002-10-23,Measurement of $ep \to e^{'}pπ^{+}π^{-}$ and baryon resonance analysis,"The cross section for the reaction $ e p \to e^{\prime} p \pi^{+} \pi^{-}$
was measured in the resonance region for 1.4$<$W$<$2.1 GeV and 0.5$<Q^{2}<$1.5
GeV$^{2}$/c$^{2}$ using the CLAS detector at Jefferson Laboratory. The data
shows resonant structures not visible in previous experiments. The comparison
of our data to a phenomenological prediction using available information on
$N^{*}$ and $\Delta$ states shows an evident discrepancy. A better description
of the data is obtained either by a sizeable change of the properties of the
$P_{13}$(1720) resonance or by introducing a new baryon state, not reported in
published analyses.",0210054v1
2003-07-29,Search for Narrow t-tbar Resonances in ppbar Collisions at \root{s} = 1.8 TeV,"A search for narrow resonances that decay into t-tbar pairs has been
performed using 130 pb^{-1} of data in the lepton+jets channel collected in
p-pbar collisions at \sqrt{s} = 1.8 TeV. There is no significant deviation
observed from the standard model, and upper limits at the 95 % confidence level
on the product of the production cross section and branching fraction to t-tbar
are presented for narrow resonances as a function of the resonance mass M_X.
These limits are used to exclude the existence of a leptophobic topcolor
particle with mass M_X < 560 GeV/c^2 and width \Gamma_X = 0.012 M_X.",0307079v1
2004-05-05,A New Analysis of the R Measurements: Resonance Parameters of the Higher Vector States of Charmonium,"The existing experimental data on total cross sections for hadron production
in e+e- annihilation in the resonance region sqrt(s) = 3.8 - 4.8 GeV, usually
presented in terms of the parameter R, are critically examined. It is shown
that the Crystal Ball and BES measurements are in excellent agreement, and
their analysis leads to consistent resonance parameters f or the three vector
resonances above the DD-bar threshold. The results for the widths are found to
be considerably different from the presently adopted values, and have much
smaller err ors.",0405007v2
2005-07-24,Dalitz Plot Study of B0 --> K+K-K0S Decays,"We present a study of the dynamics in B0 --> K+ K- K0S decays with
approximately 230 million BBbar events collected by the BABAR detector at SLAC.
We find that the Dalitz plot distribution is best parameterized with the phi
K0S mode, an S-wave K+ K- resonance near 1500 MeV/c^2, and a large non-resonant
contribution. We set limits on resonances not included in our model, and study
models for the non-resonant contribution.",0507094v1
1993-09-21,Resonant and Non-Resonant Pieces of the $D\rightarrow \bar{K}π$ Semileptonic Transition Amplitude,"We compare the resonant and non-resonant contributions in various regions of
phase space for the $D\rightarrow \bar{K}\p$ semileptonic transition amplitude,
computed in a chiral model which incorporates the heavy quark symmetry. Remarks
on the significance for experiment and for chiral perturbation theory are made.
hep-ph/yymmnnn",9309301v1
1993-09-21,Bound State Soliton Description of Low Partial Wave Octet Baryon Resonances,"A version of the bound state soliton model which allows both $\eta$ and $K$
bound states is used to study low partial wave octet baryon resonances. It is
found that negative parity $S-$wave resonances are well described within this
framework. A possible interpretation of the $P-$wave resonances is also
discussed.",9309305v1
1993-10-04,Can $γγ\rightarrow Z_L Z_L$ serve as a probe of the electroweak symmetry breaking sector ?,"We investigate the feasibility of distinguishing among different models of
electroweak symmetry breaking by studying the process $\gamma \gamma
\rightarrow Z_L Z_L$ at photon colliders. For models with a low mass Higgs-like
scalar resonance, the $s$-channel contribution provides a distinct resonance
structure and large cross sections. However, the absence of a resonance
structure in the cross section for the above process does not discriminate in
principle between the existence of either a heavy Higgs boson or a vector
resonance of a non-linearly realized symmetry.",9310217v1
1994-08-18,Parton-Hadron Duality: Resonances and Higher Twists,"We explore the physics of the parton-hadron duality in the nucleon structure
functions appearing in lepton-nucleon scattering. We stress that the duality
allows one to extract the higher-twist matrix elements from data in the
resonance region, and learn about the properties of resonances if these matrix
elements are known. As an example, we construct the moments of $F_2(x, Q^2)$
for the low and medium $Q^2$ region, and from which we study the interplay
between higher twists and the resonance contributions.",9408317v1
1994-09-06,Enhancement of CP Violation in B^+- to K_i^+- D^0 By Resonant Effects,"Resonance width effects in charged $B$ decays to neutral $D$ mesons and
excited kaon states $K_i$ around 1400 MeV are shown to lead to large calculable
final state phases. $CP$ asymmetries are defined for any charged $B$ decay to
three pseudoscalar mesons involving intermediate overlapping resonance states.
Asymmetries up to about 10$\%$ are found in $B^+\to K^+_i D^0\to (K\pi)^+ D^0$.
Decay distributions can be used to determine the weak phase $\gamma$ of the
Cabibbo-Kobayashi-Maskawa (CKM) matrix. No separation of the contributions from
individual resonances is required.",9409229v1
1995-07-31,A $J^π= 0^-$ Resonance for $πNN \to πNN $ in the Skyrme Model,"The scattering of pions on a dibaryon configuration is analyzed within the
$SU(2)$ Skyrme model. It is shown that this model leads to a low-lying
$(J^P,I)= (0^-,2)$ resonance. The possibility that this resonance corresponds
to one proposed recently in the context of double charge exchange pion
scattering on nuclei is discussed. Given the setup used in those experiments we
also show that a resonance with isospin assignment $I=0$ cannot be excited
according to the description presented here.",9507459v1
1996-01-24,$WW$ resonance and chiral Lagrangian,"We discuss the sensitivity of the $e^+ e^- \rightarrow W^+ W^-$ cross section
at a future $e^+ e^-$ collider with $\sqrt{s}=500$GeV to the non-decoupling
effects of a techni-$\rho$ like vector resonance. The non-decoupling effects
are parametrized by the chiral coefficients of the electroweak chiral
perturbation theory. We define renormalization scale independent chiral
coefficients by subtracting the Standard Model loop contributions. We also
estimate the size of the decoupling effects of the techni-$\rho$ resonance by
using a phenomenological Lagrangian including the vector resonance.",9601318v1
1996-03-15,Restriction to Parametric Resonant Decay after Inflation,"We study parametric resonant decay of inflaton field with emphasis on its
physical meaning. We show that the parametric resonance is indeed an induced
process, which means that the more numbers of produced particles, the more
inflaton field decays. We also consider the dissipative effects of produced
particles and find that the dissipation reduces the resonant decay rate of
inflaton field.",9603317v3
1996-06-27,Heavy Baryon Chiral Perturbation Theory and the Spin 3/2 Delta Resonances,"Heavy baryon chiral perturbation theory is briefly reviewed, paying
particular attention to the role of the spin 3/2 delta resonances. The concept
of resonance saturation for the baryonic sector is critically discussed.
Starting from a relativistic formulation of the pion-nucleon-delta system, the
heavy baryon chiral lagrangian including spin 3/2 resonances is constructed by
means of a 1/m-expansion. The effective theory obtained admits a systematic
expansion in terms of soft momenta, the pion mass $M_\pi$ and the delta-nucleon
mass difference $\Delta$.",9606455v1
1996-09-20,Resonance Spectrum of the strongly interacting Symmetry Breaking Sector,"Within the chiral lagrangian formalism it is possible to describe the general
strongly coupled Symmetry Breaking Sector in terms of a few parameters. Based
on a dispersive approach we have studied the resonance spectrum up to 3 TeV in
the chiral parameter space. This procedure could also be useful to extract the
higher energy resonant behavior from low-energy collider data. It is also shown
how the method reproduces the correct pole structure of resonances as well as
other analytic features. The results also hint at a possible excluded region of
parameter space.",9609427v1
1997-07-04,Resonant and non-resonant amplification of massless gauge fields during an oscillating dilaton phase,"The resonant and non-resonant amplification of electromagnetic
inhomogeneities is investigated within a phase of coherent dilaton
oscillations. We show, in some explicit toy model, how the critical energy
density bound applied to the amplified fluctuations of the massless gauge
fields can constrain the dilaton mass.",9707246v1
1999-02-15,The role of resonances in non-leptonic hyperon decays,"We examine the importance of resonances for the non-leptonic hyperon decays
in the framework of chiral perturbation theory. Lower lying resonances are
included into the effective theory. Integrating out the heavy degrees of
freedom in the resonance saturation scheme generates higher order counterterms
in the effective Lagrangian, providing an estimate of the pertinent coupling
constants. A fit to the eight independent decay amplitudes that are not related
by isospin symmetry is performed and reasonable agreement for both s- and p-
waves is achieved.",9902351v1
1999-04-06,A New Technique for Determining the Properties of a Narrow $s$-channel Resonance at a Muon Collider,"We explore an alternative to the usual procedure of scanning for determining
the properties of a narrow $s$-channel resonance. By varying the beam energy
resolution while sitting on the resonance peak, the width and branching ratios
of the resonance can be determined. The statistical accuracy achieved is
superior to that of the usual scan procedure in the case of a light SM-like
Higgs boson with $\mh>130\gev$ or for the lightest pseudogoldstone boson of a
strong electroweak breaking model if $\mpzero>150\gev$.",9904253v1
1999-05-19,Resonances in weak nonleptonic Omega^- decay,"We examine the importance of J^P = 1/2^+, 1/2^- resonances for weak
nonleptonic Omega^- decays within the framework of chiral perturbation theory.
The spin-1/2 resonances are included into an effective theory and tree
contributions to the Omega^- decays are calculated. We find significant
contributions to the decay amplitudes and satisfactory agreement with
experiment. This confirms and extends previous results wherein such spin-1/2
resonances were included in nonleptonic and radiative-nonleptonic hyperon
decays.",9905398v1
2001-02-09,Photoproduction of eta and eta-prime mesons off nucleons close to threshold,"The importance of Born terms and resonance exchange for eta and eta-prime
photoproduction off both the proton and neutron within U(3) baryon chiral
perturbation theory is investigated. Low-lying resonances such as the vector
mesons and J^P= 1/2^+, 1/2^- baryon resonances are included explicitly and
their contributions together with the Born terms are calculated. The coupling
constants of the resonances are determined from strong and radiative decays. We
obtain reasonable agreement with experimental data near threshold.",0102112v1
2001-06-20,Photo-production of Nucleon Resonances and Nucleon Spin Structure Function in the Resonance Region,"The photo-production of nucleon resonances is calculated based on a chiral
constituent quark model including both relativistic corrections H{rel} and
two-body exchange currents, and it is shown that these effects play an
important role. We also calculate the first moment of the nucleon spin
structure function g1 (x,Q^2) in the resonance region, and obtain a
sign-changing point around Q^2 ~ 0.27 {GeV}^2 for the proton.",0106225v2
2001-07-06,An example of resonance saturation at one loop,"We argue that the large-Nc expansion of QCD can be used to treat a Lagrangian
of resonances in a perturbative way. As an illustration of this we compute the
L_10 coupling of the Chiral Lagrangian by integrating out resonance fields at
one loop. Given a Lagrangian and a renormalization scheme, this is how in
principle one can answer in a concrete and unambiguous manner questions such as
at what scale resonance saturation takes place.",0107062v2
2001-09-21,GaGaRes: A Monte Carlo generator for resonance production in two-photon physics,"In this paper a Monte Carlo generator, GaGaRes, is presented which can be
used to describe two-photon resonance production in e^+e^- collisions. The
program can generate the five lowest-lying C=+1 meson states of any q\bar{q}
combination together with the outgoing electron and positron. The dependence on
the photon virtualities Q_1^2 and Q_2^2 is fully taken into account. The
program also generates the density matrices of the resonance, which form an
essential tool in the description of the decay of the resonances. Furthermore,
the program is applicable for all tagging conditions.",0109195v1
2001-10-15,Identification of Randall-Sundrum Graviton Resonances at Linear Colliders,"We discuss several methods which can be used to distinguish the graviton
resonances of the Randall-Sundrum model from the graviton-like resonances which
may occur in other theories. The Breit-Wigner line shape of the RS graviton is
found to be particularly useful. In particular we show that the ""effective""
graviton resonance present in the model of Dvali et al ~can be distinguished
from those of the Randall-Sundrum scenario for a reasonably wide range of model
parameters.",0110202v1
2002-01-14,Strange Resonance Production: Probing Chemical and Thermal Freeze-out in Relativistic Heavy Ion Collisions,"The production and the observability of $\Lambda(1520)$, $K^0(892)$ $\Phi$
and $\Delta(1232)$ hadron resonances in central Pb+Pb collisions at 160 AGeV is
addressed. The rescattering probabilities of the resonance decay products in
the systems evolution are studied. Strong changes in the reconstructable
particle yields and spectra between chemical and thermal freeze-out are
estimated. Abundances and spectra of reconstructable resonances are predicted.",0201123v1
2003-11-20,The Hadronic Cross-Section in the Resonance Energy Region,"We study the hadronic vacuum polarization in the resonance energy region,
using the framework given by the Resonance Effective Theory of QCD. We consider
the incorporation of vector-pseudoscalar meson loops that give, inclusively,
three and four pseudoscalar meson cuts. After resummation we achieve a
QCD-based inclusive parameterization of the correlator, hence of the hadronic
cross-section in the energy region populated by resonances.",0311251v1
2004-08-05,Pion and Kaon Decay Constants: Lattice vs. Resonance Chiral Theory,"The Lattice results for the pion and kaon decay constants are analysed within
the Resonance Chiral Theory framework in the large NC limit. The approximately
linear behaviour of the observable at large light-quark mass is explained
through the interaction with the lightest multiplet of scalar resonances. The
analysis of the Lattice results allows to obtain the resonance mass MS=1049 +-
25 MeV and the Chiral Perturbation Theory parameters at leading order in 1/NC.",0408080v1
2004-11-01,Some Remarks on Exotic Resonances,"Using large $N_c$ counting rule, it is argued that tetra-quark resonances do
not exist. Also it is pointed out that there exists the violation of exchange
degeneracy in the exotic $KN$ scattering channel. It implies either the failure
of resonance saturation assumption or it suggests the existence of exotic
baryon resonances in such a channel.",0411025v1
2005-01-13,Resonance production by neutrinos: I. J=3/2 Resonances,"The article contains general formulas for the production of J=3/2 resonances
by neutrinos and antineutrinos. It specializes to the P_{33}(1232) resonance
whose form factors are determined by theory and experiment and then are
compared with experimental results at low and high energies. It is shown that
the minimum in the low Q^2 region is a consequence of a combined effect from
the vanishing of the vector form factors, the muon mass and Pauli blocking.
Several improvements for the future investigations are suggested.",0501109v2
2005-04-28,Resonance radiative decays as a tool for its parity determination,"Radiative decays of the spin 1/2 baryonic resonances R with the decay mode R
-> KN in case of small energy release are considered. Pentaquark is an example
of such resonance. It is shown that in case of positive resonance parity
corrections to the soft photon radiation formula are large even at low photon
energies > 20 MeV and structure terms contributions may be essential, if R size
> 1 fm. This effect is absent in case of negative parity. Particularly,
measurements of the gamma spectrum in pentaquark radiative decays may allow us
to determine its parity.",0504268v1
2005-08-28,Relic Abundance of LKP Dark Matter in UED model including Effects of Second KK Resonances,"We reevaluate the thermal relic density of the Kaluza-Klein (KK) dark matter
in universal extra dimension models. In particular, we consider the effect of
the resonance caused by second KK particles on the density. We find that the
annihilation cross sections relevant to the density are significantly enhanced
due to the resonance when the Higgs boson mass is large enough (m_h \gtrsim 200
GeV). As a result, the mass of the dark matter particle consistent with the
WMAP observation is increased compared to the result which does not include any
resonance.",0508283v1
2005-11-26,Limit Temperatures for Meson and Diquark Resonances in a Strongly Interacting Quark Matter,"We investigate mesons and diquarks as resonant states above chiral critical
temperature $T_c$ in flavor SU(2) Nambu--Jona-Lasinio model. For each kind of
resonance, we solve the pole equation for the resonant mass in the complex
energy plane, and find an ultimate temperature where the pole starts to
disappear. The phase diagram including these limit temperatures in $T-\mu$
plane is obtained. The maximum limit temperature at $\mu=0$ is approximately
two times $T_c$.",0511300v1
2006-03-20,The piN --> etaN data demand the existence of N(1710) P11 resonance reducing the 1700 MeV continuum ambiguity,"In spite of prolonged polemics, the agreement on the existence of N(1710) P11
resonance has not until now been reached, and the Particle Data Group declares
it as a 3-star resonance only. We show that the proper inclusion of inelastic
channels in the coupled-channel formalism indisputably demands the existence of
N(1710) P11 state, and that it presumably stays ""hidden"" within the continuum
ambiguity of any typical single channel partial wave analyses. Consequently,
its Particle Data Group confidence rating should be raised to a 4-star
resonance.",0603144v1
2006-11-29,Vanishing chiral couplings in the large-N_C resonance theory,"The construction of a resonance theory involving hadrons requires
implementing the information from higher scales into the couplings of the
effective Lagrangian. We consider the large-Nc chiral resonance theory
incorporating scalars and pseudoscalars, and we find that, by imposing LO
short-distance constraints on form factors of QCD currents constructed within
this theory, the chiral low-energy constants satisfy resonance saturation at
NLO in the 1/Nc expansion.",0611375v2
1992-08-03,Exact resonance A-D-E S-matrices and their renormalization group trajectories,"We introduce the A-D-E resonance factorized models as an appropriate
analytical continuation of the Toda S-matrices to the complex values of their
coupling constant. An investigation of the associated Casimir energy, via the
thermodynamic Bethe ansatz, reveals a rich pattern of renormalization group
trajectories interpolating between the central charges of the $G_1 \otimes G_k
/ G_{k+1}$ GKO coset models. We have also constructed the simplest resonance
factorized model satisfying the ``$\phi^3$''-property. From this resonance
scattering, we predict new flows in non-unitary minimal models.",9208011v1
2003-12-02,Is a quantum theory of resonances really time asymmetric?,"The title ""Time Asymmetric Quantum Theory: the Theory of Resonances"" (without
questionmark) of the CFIF workshop (23.-26.7.2003, Lisbon, Portugal) implies
that the theoretical description of resonances is uniquely described by the
formalism of A. Bohm et al. reflecting the title of the workshop. Our
presentation in this workshop tries to introduce an apparently inequivalent,
alternative feasible relativistic formalism provided by the author under the
name ""(Anti)Causal Quantum Theory"" which is compared to the former.",0312027v1
2005-12-06,Resonances in the one-dimensional Dirac equation in the presence of a point interaction and a constant electric field,"We show that the energy spectrum of the one-dimensional Dirac equation in the
presence of a spatial confining point interaction exhibits a resonant behavior
when one includes a weak electric field. After solving the Dirac equation in
terms of parabolic cylinder functions and showing explicitly how the resonant
behavior depends on the sign and strength of the electric field, we derive an
approximate expression for the value of the resonance energy in terms of the
electric field and delta interaction strength.",0512073v1
2001-05-02,Asymptotic description of nonlinear resonance,"We study a hard regime of stimulation of two-frequency oscillations in the
main resonance equation with a fast oscillating external force: $ \ve i \psi' +
|\psi|^2\psi = \exp\big(it^2/ (2\ve)\big), 0<\ve\ll1$. This phenomenon is
caused by resonance between an eigenmode and the external force. The asymptotic
solution before, inside and after the resonance layer is studied in detail and
matched.",0105011v1
2003-04-24,Quantum resonances and partial differential equations,"Resonances, or scattering poles, are complex numbers which mathematically
describe meta-stable states: the real part of a resonance gives the rest
energy, and its imaginary part, the rate of decay of a meta-stable state. This
description emphasizes the quantum mechanical aspects of this concept but
similar models appear in many branches of physics, chemistry and mathematics,
from molecular dynamics to automorphic forms. In this article we will will
describe the recent progress in the study of resonances based on the theory of
partial differential equations.",0304400v1
2005-11-30,Semiclassical resonances for a two-level Schrödinger operator with a conical intersection,"We study the resonant set of a two-level Schr\""odinger operator with a linear
conical intersection. This model operator can be decomposed into a direct sum
of first order systems on the real half-line. For these ordinary differential
systems we locally construct exact WKB solutions, which are connected to global
solutions, amongst which are resonant states. The main results are a
generalized Bohr-Sommerfeld quantization condition and an asymptotic
description of the set of resonances as a distorted lattice.",0511724v2
2002-09-30,Asymptotic approximation of hyperbolic weakly nonlinear systems,"An averaging method for getting uniformly valid asymptotic approximations of
the solution of hyperbolic systems of equations is presented. The averaged
system of equations disintegrates into independent equations for non-resonance
systems. We consider the resonance conditions for some classes of solutions.
The averaged system can be solved numerically in the resonance case. The
shallow water problem is considered as an example of the resonance system.
Results of numerical experiments are presented.",0209064v1
2007-01-31,Exact and quasi-resonances in discrete water-wave turbulence,"The structure of discrete resonances in water-wave turbulence is studied. It
is shown that the number of exact 4-wave resonances is huge (hundreds million)
even in comparatively small spectral domain when both scale and angle energy
transport is taken into account. It is also shown that angle transport can
contribute inexplicitly to scale transport. Restrictions for quasi-resonances
to start are written out. The general approach can be applied directly to
mesoscopic systems encountered in condensed matter (quantum dots), medical
physics, etc.",0701077v3
2000-01-10,Frobenius-Perron Resonances for Maps with a Mixed Phase Space,"Resonances of the time evolution (Frobenius-Perron) operator P for phase
space densities have recently been shown to play a key role for the
interrelations of classical, semiclassical and quantum dynamics. Efficient
methods to determine resonances are thus in demand, in particular for
Hamiltonian systems displaying a mix of chaotic and regular behavior. We
present a powerful method based on truncating P to a finite matrix which not
only allows to identify resonances but also the associated phase space
structures. It is demonstrated to work well for a prototypical dynamical
system.",0001013v2
2000-03-17,Scaling law in the Standard Map critical function. Interpolating hamiltonian and frequency map analysis,"We study the behaviour of the Standard map critical function in a
neighbourhood of a fixed resonance, that is the scaling law at the fixed
resonance. We prove that for the fundamental resonance the scaling law is
linear. We show numerical evidence that for the other resonances $p/q$, $q \geq
2$, $p \neq 0$ and $p$ and $q$ relatively prime, the scaling law follows a
power--law with exponent $1/q$.",0003040v1
2000-05-16,The leading Ruelle resonances of chaotic maps,"The leading Ruelle resonances of typical chaotic maps, the perturbed cat map
and the standard map, are calculated by variation. It is found that, excluding
the resonance associated with the invariant density, the next subleading
resonances are, approximately, the roots of the equation $z^4=\gamma$, where
$\gamma$ is a positive number which characterizes the amount of stochasticity
of the map. The results are verified by numerical computations, and the
implications to the form factor of the corresponding quantum maps are
discussed.",0005030v1
2001-02-12,Resonance zones in action space,"The classical and quantum mechanics of isolated, nonlinear resonances in
integrable systems with N>=2 degrees of freedom is discussed in terms of
geometry in the space of action variables. Energy surfaces and frequencies are
calculated and graphically presented for invariant tori inside and outside the
resonance zone. The quantum mechanical eigenvalues, computed in the
semiclassical WKB approximation, show a regular pattern when transformed into
the action space of the associated symmetry reduced system: eigenvalues inside
the resonance zone are arranged on N-dimensional cubic lattices, whereas those
outside are, in general, non-periodically distributed. However, N-dimensional
triclinic (skewed) lattices exist locally. Both kinds of lattices are joined
smoothly across the classical separatrix surface. The statements are
illustrated with the help of two and three coupled rotors.",0102014v1
2001-05-08,Spatial solitons in a pumped semiconductor resonator,"Bright and dark spatial solitons are observed in an optically pumped
semiconductor resonator. The pumping allows to considerably reduce the light
intensity necessary for the existence of the solitons and alleviates thermal
load problems. Experiments are found to agree with calculations based on a
simple large aperture semiconductor resonator model. The role of signs of the
absorptive and reactive nonlinearities for soliton existence are discussed in
relation with the nonlinear resonance effect, the tilted wave mechanism of
pattern formation, and the sign of the population inversion.",0105019v1
2001-05-15,Rigged Hilbert Space Approach to Spectral Analysis of the Frobenius-Perron Operator for the Tent-map,"On the basis of an unified theoretical formulation of resonances and
resonance states in the rigged Hilbert spaces the spectral analysis of the
Frobenius-Perron operators corresponding to the exactly solvable chaotic map
has been developed. Tent map as the simplest representative of exactly solvable
chaos have been studied in details in frames of the developed approach. An
extension the Frobenius-Perron operator resolvent to a suitable rigged Hilbert
space has been constructed in particular and the properties of the generalized
spectral decomposition have been studied. Resonances and resonance projections
for this map have been calculated explicitly.",0105037v1
2002-05-02,Stable Quantum Resonances in Atom Optics,"A theory for stabilization of quantum resonances by a mechanism similar to
one leading to classical resonances in nonlinear systems is presented. It
explains recent surprising experimental results, obtained for cold Cesium atoms
when driven in the presence of gravity, and leads to further predictions. The
theory makes use of invariance properties of the system, that are similar to
those of solids, allowing for separation into independent kicked rotor
problems. The analysis relies on a fictitious classical limit where the small
parameter is {\em not} Planck's constant, but rather the detuning from the
frequency that is resonant in absence of gravity.",0205006v1
2002-12-22,Monodromy in the resonant swing spring,"This paper shows that an integrable approximation of the spring pendulum,
when tuned to be in $1:1:2$ resonance, has monodromy. The stepwise precession
angle of the swing plane of the resonant spring pendulum is shown to be a
rotation number of the integrable approximation. Due to the monodromy, this
rotation number is not a globally defined function of the integrals. In fact at
lowest order it is given by $\arg(a+ib)$ where $a$ and $b$ are functions of the
integrals. The resonant swing spring is therefore a system where monodromy has
easily observed physical consequences.",0212048v1
2003-06-04,Resonant phenomena in slowly perturbed elliptic billiards,"We consider an elliptic billiard whose shape slowly changes. During slow
evolution of the billiard certain resonance conditions can be fulfilled. We
study the phenomena of capture into a resonance and scattering on resonances
which lead to the destruction of the adiabatic invariance in the system.",0306004v2
2003-07-27,Is Arnold diffusion relevant to global diffusion?,"Global diffusion of Hamiltonian dynamical systems is investigated by using a
coupled standard maps. Arnold web is visualized in the frequency space, using
local rotation numbers, while Arnold diffusion and resonance overlaps are
distinguished by the residence time distributions at resonance layers. Global
diffusion in the phase space is shown to be accelerated by diffusion across
overlapped resonances generated by the coupling term, rather than Arnold
diffusion along the lower-order resonances. The former plays roles of hubs for
transport in the phase space, and accelerate the diffusion.",0307050v1
2004-10-18,Scattering of solitons on resonance. Asymptotics and numeric simulations,"We investigate a propagation of solitons for nonlinear Schr\""odinger equation
under small driving force. The driving force passes through the resonance. The
process of scattering on the resonance leads to changing of number of solitons.
After the resonance the number of solitons depends on the amplitude of the
driving force. The analytical results were obtained by WKB and matching method.
We bring two examples of numeric simulations for verifying obtained analytical
formulas.",0410024v1
2005-06-17,"Stochastic Resonance in Underdamped, Bistable Systems","We carry out a detailed numerical investigation of stochastic resonance in
underdamped systems in the non-perturbative regime. We point out that an
important distinction between stochastic resonance in overdamped and
underdamped systems lies in the lack of dependence of the amplitude of the
noise-averaged trajectory on the noise strength, in the latter case. We provide
qualitative explanations for the observed behavior and show that signatures
such as the initial decay and long-time oscillatory behaviour of the temporal
correlation function and peaks in the noise and phase averaged power spectral
density, clearly indicate the manifestation of resonant behaviour in noisy,
underdamped bistable systems in the weak to moderate noise regime.",0506039v1
2005-10-05,Isomonodromic deformation of resonant rational connections,"We analyze isomonodromic deformations of rational connections on the Riemann
sphere with Fuchsian and irregular singularities. The Fuchsian singularities
are allowed to be of arbitrary resonant index; the irregular singularities are
also allowed to be resonant in the sense that the leading coefficient matrix at
each singularity may have arbitrary Jordan canonical form, with a genericity
condition on the Lidskii submatrix of the subleading term. We also give the
relevant notion of isomonodromic tau function extending the one of non-resonant
deformations introduced by Miwa-Jimbo-Ueno. The tau function is expressed
purely in terms of spectral invariants of the matrix of the connection.",0510011v1
2006-06-01,Stochastic resonance as a filter for signal detection from multisignal inputs,"We undertake a detailed numerical study of the phenomenon of stochastic
resonance with multisignal inputs. A bistable cubic map is used as the model
and we show that it combines the features of a bistable system and a threshold
system. A study of stochastic resonance in these two setups reveal some
fundamental differences between the two mechanisms with respect to
amplification of a composite input signal. As a practically relevant result, we
show that the phenomenon of stochastic resonance can be used as a filter for
the detection/transmission of the component frequencies in a composite signal.",0606006v1
2007-03-13,Directional emission from weakly eccentric resonators,"It is shown that when a circular resonator is deformed in a nonintegrable
way, a symmetry breaking of escaping rays occurs which can dramatically
modulate the outgoing wave even for small perturbations. The underlying
mechanism does not occur in integrable models for which the ray families can be
computed exactly and is described in this Letter on the basis of canonical
perturbation theory. Emission from deformed resonators is currently of immense
practical interest in the context of whispering-gallery optical resonances of
dielectric cavities and the approach outlined here promises simple analytical
characterisations in the important case of small deformations.",0703022v2
2000-11-23,Observation of the scissors mode in the quasicontinuum,"The experimental resonance parameters of the pygmy resonance in rare earth
nuclei are compared to global parameters of the scissors-mode states. It is
argued that the pygmy resonance in rare earth nuclei can be described in terms
of orbital M1 strength observed in (gamma,gamma') experiments. The pygmy
resonance is therefore interpreted as the scissors mode in the quasicontinuum.",0011018v1
2004-02-26,"Absolute resonance strengths in the 6,7Li(alpha,gamma)10,11B reactions","The absolute strengths of the Ea=1175keV resonance in the 6Li(a,g)10B
reaction and of the Ea=814 keV resonance in the 7Li(a,g)11B reaction have been
measured to $\omega\gamma$=366+-38 meV and $\omega\gamma$=300+-32 meV,
respectively, in good agreement with previous values.
  These resonances can be used to measure the absolute acceptance of the recoil
separator ERNA to a precision of about 10%.",0402020v1
2004-12-06,In-medium properties of nucleon resonances,"Recent experimental results for the in-medium properties of nucleon
resonances are discussed. The experiments were done with the TAPS detector at
the tagged photon beam of the MAMI accelerator in Mainz. Measured was the
photoproduction of mesons (final states $\pi^o X$, $\eta X$, $2\pi^oX$ and
$\pi^o\pi^{\pm}X$) from the nuclei $^{12}$C, $^{40}$Ca, $^{93}$Nb, and
$^{208}$Pb up to the second resonance region. The results were analyzed in view
of the in-medium properties of the P$_{33}$(1232), the D$_{13}$(1520), and the
S$_{11}$(1535) resonances.",0412006v1
1994-10-28,Time Reversal Symmetry Breaking Effects in Resonant Nuclear Reactions,"We incorporate time reversal symmetry breaking (TRSB) effects into the theory
of compound nuclear reactions. We show that the only meaningful test of TRSB in
the overlapping resonances regime is through the study of cross-section
correlations. The effect is channel-dependent. In the isolated resonance
regime, we employ $K$-matrix theory to show the impact of TRSB using the fact
that when only one eigen-channel participates in populating and depopulating
the compound resonance.",9410047v1
1997-08-14,"S-matrix studies of resonances in A=3,4,5,6, and 12 nucleon systems","Resonances of certain light nuclei are explored by studying the complex pole
structures of the scattering matrices. Among other results we predict the
existence of three-neutron and three-proton resonances, a small spin-orbit
splitting in the low-lying He-5 and Li-5 states and the nonexistence of the
soft dipole resonance in He-6.",9708024v1
1997-11-08,Cooperative damping mechanism of the resonance in the nuclear photoabsorption,"We propose a resonance damping mechanism to explain the disappearance of the
peaks around the position of the resonances higher than the $\Delta$ resonance
in the nuclear photoabsorption. This phenomenon is understood by taking into
account the cooperative effect of the collision broadening of $\Delta$ and
$N^{*}$, the pion distortion and the interference in the two-pion
photoproduction processes in the nuclear medium.",9711017v4
1997-12-11,Nucleon resonances in the constituent quark model with chiral symmetry,"The mass spectra of nucleon resonances with spin 1/2, 3/2, and 5/2 are
systematically studied in the constituent quark model with meson-quark
coupling, which is inspired by the spontaneous breaking of chiral symmetry of
QCD.
  The meson-quark coupling gives rise not only to the one-meson-exchange
potential between quarks but also to the self-energy of baryon resonances due
to the existence of meson-baryon decay channels.
  The two contributions are consistently taken into account in the calculation.
  The gross properties of the nucleon resonance spectra are reproduced fairly
well although the predicted mass of N(1440) is too high.",9712042v1
1998-01-19,Exchange Currents in Photoproduction of Baryon Resonances,"We calculate photoexcitation amplitudes for several nucleon and delta
resonances. We use a chiral quark model including two-body exchange currents.
The two-body currents give important contributions. For the delta (1232) and
the D13 (1520) we observe that the individual exchange current contributions
considerably cancel each other while in the case of the Roper resonance and the
S11 (1535) we get a reinforcement of the two-body amplitudes. In comparison
with present experimental data, we obtain both for the S11 (1535) and for the
Roper resonance an improvement with respect to the impulse approximation.",9801031v1
1998-05-01,Deduction of the quantum numbers of low-lying states of 4-nucleon systems based on symmetry,"The inherent nodal structures of the wavefunctions of 4-nucleon systems have
been investigated. The quantum numbers of the excited states (resonances) have
been deduced. It was found that all the T=0 even-parity resonances are
dominated by {2,1,1} component with L=1, all the T=0 odd-parity resonances are
dominated by {3,1} component with L=1, and all the T=1 odd-parity resonances
are also dominated by {3,1} component with L=1. The understanding of the
inherent nodal structure is found to be crucial to a systematic understanding
of the spectrum.",9805001v1
1998-07-03,Scaling Properties of the Giant Dipole Resonance Width in Hot Rotating nuclei,"We study the systematics of the giant dipole resonance width $\Gamma$ in hot
rotating nuclei as a function of temperature $T$, spin $J$ and mass $A$. We
compare available experimental results with theoretical calculations that
include thermal shape fluctuations in nuclei ranging from A=45 to A=208. Using
the appropriate scaled variables, we find a simple phenomenological function
$\Gamma(A,T,J)$ which approximates the global behavior of the giant dipole
resonance width in the liquid drop model. We reanalyze recent experimental and
theoretical results for the resonance width in Sn isotopes and $^{208}$Pb.",9807012v1
1999-05-07,Influence of damping on the excitation of the double giant resonance,"We study the effect of the spreading widths on the excitation probabilities
of the double giant dipole resonance. We solve the coupled-channels equations
for the excitation of the giant dipole resonance and the double giant dipole
resonance. Taking Pb+Pb collisions as example, we study the resulting effect on
the excitation amplitudes, and cross sections as a function of the width of the
states and of the bombarding energy.",9905018v2
1999-06-30,Evidence for a missing nucleon resonance in kaon photoproduction,"New SAPHIR p(gamma,K+)Lambda total cross section data show a resonance
structure at a total c.m. energy around 1900 MeV. We investigate this feature
with an isobar model and find that the structure can be well explained by
including a new D_{13} resonance at 1895 MeV. Such a state has been predicted
by a relativistic quark model at 1960 MeV with significant gamma-N and K-Lambda
branching ratios. We demonstrate how the measurement of the photon asymmetry
can be used to further study this resonance. In addition, verification of the
predicted large decay widths into the eta-N and eta'-N channels would allow
distinguishing between other nearby D_{13} states.",9906096v1
1999-08-10,Low-energy eta-d resonance,"Elastic eta-d scattering is considered within the Alt-Grassberger-Sandhas
(AGS) formalism for various eta-N input data. A three-body resonant state is
found close to the eta-d threshold. This resonance is sustained for different
choices of the two-body eta-N scattering length a_{\eta N}. The position of the
resonance moves towards the eta-d threshold when Re a_{\eta N} is increased,
and turns into a quasi-bound state at Re a_{\eta N}=0.733 fm.",9908035v1
1999-09-30,Integral equations for three-body Coulombic resonances,"We propose a novel method for calculating resonances in three-body Coulombic
systems. The method is based on the solution of the set of Faddeev and
Lippmann-Schwinger integral equations, which are designed for solving the
three-body Coulomb problem. The resonances of the three-body system are defined
as the complex-energy solutions of the homogeneous Faddeev integral equations.
We show how the kernels of the integral equations should be continued
analytically in order that we get resonances. As a numerical illustration a toy
model for the three-$\alpha$ system is solved.",9909083v1
2000-12-05,Nucleon resonances in polarized omega photoproduction,"The role of the nucleon resonances ($N^*$) in $\omega$ photoproduction is
investigated by using the resonance parameters predicted by Capstick and
Roberts. The contributions from the nucleon resonances are found to be
significant in various spin asymmetries. In particular, we found that a crucial
test of our predictions can be made by measuring the parity asymmetry and
beam-target double asymmetry at forward scattering angles.",0012012v1
2001-05-04,"The role of hyperon resonances in p(gamma,K+)Lambda processes","We discuss the role of hyperon resonances in the u-channel when modeling p
(gamma,K+)Lambda processes in an effective Lagrangian approach. Without the
introduction of hyperon resonances, one is forced to use soft hadronic form
factors with a cutoff mass which is at best two times the kaon mass. After
inclusion of the hyperon resonances in the u-channel, we obtain a fair
description of the data with a cutoff mass of the order of 1.8 GeV.",0105008v1
2001-05-22,In-medium broadening of nucleon resonances,"We analyze the effects of an in-medium broadening of nucleon resonances on
the exclusive photoproduction of mesons on nuclei as well as on the total
photoabsorption cross sections in a transport calculation. We show that the
resonance widths observed in semi-inclusive photoproduction on nuclei are
insensitive to an in-medium broadening of nucleon resonances. This is due to a
simple effect: the sizeable width of the nuclear surface and Fermi motion.",0105054v2
2001-08-09,Isoscalar-Isovector Interferences in $πN \to N e^+ e^-$ Reactions as a Probe of Baryon Resonance Dynamics,"The isoscalar-isovector ($\rho-\omega$) interferences in the exclusive
reactions $\pi^- p \to n e^+ e^-$ and $\pi^+ n \to p e^+ e^-$ near the $\omega$
threshold leads to a distinct difference of the dielectron invariant mass
distributions depending on beam energy. The strength of this effect is
determined by the coupling of resonances to the nucleon vector-meson channels
and other resonance properties. Therefore, a combined analysis of these
reactions can be used as a tool for determining the baryon resonance dynamics.",0108019v1
2001-11-01,Study of Nucleon Resonances with Double Polarization Observables of Pion Photoproduction,"The role of the nucleon resonances in the double polarization observables of
pion photoproduction is investigated by using the resonance parameters
predicted by Capstick and Roberts. As an example, we show that the
not-well-determined two-star resonance N$^{-}_{3/2}$(1960) can be examined by
performing experiments on beam-recoil polarization at large angles.",0111005v2
2002-01-28,Two-Particle Resonant States in a Many-Body Mean Field,"A formalism to evaluate the resonant states produced by two particles moving
outside a closed shell core is presented. The two particle states are
calculated by using a single particle representation consisting of bound
states, Gamow resonances and scattering states in the complex energy plane
(Berggren representation). Two representative cases are analysed corresponding
to whether the Fermi level is below or above the continuum threshold. It is
found that long lived two-body states (including bound states) are mostly
determined by either bound single-particle states or by narrow Gamow
resonances. However, they can be significantly affected by the continuum part
of the spectrum.",0201077v1
2002-02-08,Electromagnetic transitions between giant resonances within a continuum-RPA approach,"A general continuum-RPA approach is developed to describe electromagnetic
transitions between giant resonances. Using a diagrammatic representation for
the three-point Green's function, an expression for the transition amplitude is
derived which allows one to incorporate effects of mixing of single and double
giant resonances as well as to take the entire basis of particle-hole states
into consideration. The radiative widths for E1 transition between the
charge-exchange spin-dipole giant resonance and Gamow-Teller states are
calculated for ^{90}Nb and ^{208}Bi nuclei. The importance of the mixing is
stressed.",0202029v2
2002-03-20,Fano theory for hadronic resonances: the rho meson and the pionic continuum,"We develop a model-independent analysis of hadronic scattering data in the
resonance region, where the resonance shape follows from the matrix elements of
a Hamiltonian. We investigate the rho meson in the tau decay. We demonstrate
that the rho meson resonance in the two-pion decay of the tau lepton is
described well through the coupling of a bare rho meson to the two-pion and the
four-pion continuum. Furthermore, this four-pion continuum corresponds with the
data of the four-pion decay channel of the tau lepton at energies up to 1.1
GeV.",0203054v1
2002-04-16,"On the spin, parity and nature of the $Ξ(1620)$ resonance","Using a unitary extension of chiral perturbation theory with a lowest-order
s-wave SU(3) chiral Lagrangian we study low-energy meson-baryon scattering in
the strangeness $S=-2$ sector. A scattering-matrix pole is found around 1606
MeV which corresponds to an s-wave $\Xi$ resonance with $J^P=1/2^-$. We
identify this resonance with the $\Xi(1620)$ state, quoted in the Particle Data
Book with $I=1/2$ but with unknown spin and parity. The addition of the $S=-2$
state to the recently computed $\Lambda(1670)$, $\Sigma(1620)$ and N(1535)
states completes the octet of $J^P=1/2^-$ resonances dynamically generated in
this chiral unitary approach.",0204044v1
2002-10-11,Potential resonant screening effects on stellar C12+C12 reaction rates,"The C12+C12 fusion cross sections show resonant behavior down to the lowest
energies accessible so far in the laboratory. If this tendency continues into
the astrophysical energy range, the stellar C12+C12 reaction rates have to be
corrected for resonant screening effects, in addition to the conventional
screening corrections. We estimate the resonant screening effects in the weak
electron screening limit for hydrostatic burning and white dwarf environments.",0210036v1
2002-12-10,Coherent bubble-sum approximation for coupled-channel resonance scattering,"For coupled-channel resonance scattering we derive a model with a closed form
solution for the $T$-matrix that satisfies unitarity and analyticity. The
two-channel case is handled explicitly for an arbitrary number of resonances.
The method focuses on the expansion of the transition matrix elements,
$\Gamma(s)$, in known analytical functions. The appropriate hadronic form
factors and the related energy shifts can be determined from the scattering
data. The differences between this method and the $K$-matrix and the
Breit-Wigner approximation are illustrated in the case of the $S_{11}$
resonances $S_{11}(1535)$ and $S_{11}(1650)$.",0212043v1
2003-01-09,Effects of resonant single-particle states on pairing correlations,"Effects of resonant single-particle (s.p.) states on the pairing correlations
are investigated by an exact treatment of the pairing Hamiltonian on the Gamow
shell model basis. We introduce the s.p. states with complex energies into the
Richardson equations. The solution shows the property that the resonant s.p.
states with large widths are less occupied. The importance of many-body
correlations between bound and resonant prticle pairs is shown.",0301026v1
2003-03-04,Threshold Resonances - a Lattice Perspective,"The calculation of the masses of the lightest nucleon resonances using
lattice QCD is surveyed. Recent results for the mass of the first radial
excitation of the nucleon, the Roper resonance, are reviewed and the
interpretation in terms of models of hadronic resonances, such as the quark
model and hadronic molecules, discussed. The talk concludes with an outline of
prospects for future calculations.",0303009v1
2003-11-24,"Chiral symmetry, strangeness and nuclear matter","In this talk we review the important role played by chiral SU(3) symmetry in
hadron physics. Exciting new results on the formation of baryon resonances as
implied by chiral coupled-channel dynamics are presented and discussed. The
results are the consequence of progress made in formulating a consistent
effective field theory for the meson-baryon scattering processes in the
resonance region. Strangeness channels are found to play a decisive role in the
formation of resonances. As a further application of chiral coupled-channel
dynamics the properties of antikaons and hyperon resonances in cold nuclear
matter are reviewed.",0311085v1
2004-02-25,Chiral symmetry and resonances in QCD,"We study the formation of resonances in terms of the chiral SU(3) Lagrangian.
At leading order parameter-free predictions are obtained for the scattering of
Goldstone bosons off any hadron once we insist on approximate crossing symmetry
of the unitarized scattering amplitude. A wealth of empirically established
resonances are recovered and so far unseen resonances are predicted. Here we
review in some detail the properties of light axial-vector mesons.",0402084v1
2004-03-22,Spin-5/2 resonance contributions to the pion-induced reactions for energies $\sqrt{s}\leqslant$2.0 GeV,"The spin-$\ffh$ resonance effects are studied within the coupled channel
effective Lagrangian model for baryon resonance analysis. We extend our
previous hadronic calculations to incorporate the $D_{15}$, $F_{15}$, $D_{35}$,
$F_{35}$ states.
  While the effect of the spin-$\ffh$ resonances to the $\eta N$, $K \Lambda$,
and $K \Sigma$ reactions are small, the contribution to the $\omega N$ is found
to be important. The results for the 'conventional' and Pascalutsa-like
spin-$\ffh$ descriptions are discussed.
\PACS{{11.80.-m},{13.75.Gx},{14.20.Gk},{13.30.Gk}}",0403064v1
2004-03-22,"Chiral symmetry, strangeness and resonances","We review the important role played by the chiral SU(3) symmetry in
predicting the properties of antikaons and hyperon resonances in cold nuclear
matter. Objects of crucial importance are the meson-baryon scattering
amplitudes obtained within the chiral coupled-channel effective field theory.
The formation of baryon resonances as implied by chiral coupled-channel
dynamics is discussed. Results for antikaon and hyperon-resonance spectral
functions are presented for isospin symmetric and asymmetric matter.",0403065v1
2004-06-15,Chiral dynamics of the two Lambda(1405) states,"The Lambda(1405) resonance is studied by a chiral unitary approach, in which
the resonance is dynamically generated in coupled-channel meson-baryon
scattering. Investigating the analytic structure of the scattering amplitudes
obtained by the chiral unitary approach, we find two poles around the energies
of the Lambda(1405) coupling differently to the meson-baryon states. We reach
the conclusion that the Lambda(1405) resonance seen in experiments is not just
one single resonance, but a superposition of these two states.",0406047v1
2005-01-10,Resonances from Baryon decuplet-Meson octet interaction,"The s-wave interactions of the baryon decuplet with the octet of pseudoscalar
mesons is studied in a unitarized coupled channel approach. We obtain a fair
agreement for mass and width of several 3/2- resonances. In particular, the
Xi(1820), the Lambda(1520) and the Sigma(1670) states are well reproduced.
Other resonances are predicted and also the couplings of the observed
resonances to the various channels are evaluated.",0501022v1
2005-02-14,Three-neutron resonance trajectories for realistic interaction models,"Three-neutron resonances are investigated using realistic nucleon-nucleon
interaction models. The resonance pole trajectories are explored by first
adding an additional interaction to artificially bind the three-neutron system
and then gradually removing it. The pole positions for the three-neutron states
up to J=5/2 are localized in the third energy quadrant-Im (E)<=0, Re
(E)<=0-well before the additional interaction is removed. Our study shows that
realistic nucleon-nucleon interaction models exclude any possible experimental
signature of three-neutron resonances.",0502037v2
2005-05-03,A coupled-channel analysis of $KΛ$ production in the nucleon resonance region,"A unitary coupled-channel effective Lagrangian model is applied to the
combined analysis of the $(\pi,\gamma) N \to K\Lambda$ reactions in the energy
region up to 2 GeV. To constrain the resonance couplings to the $K\Lambda$
final state the recent photoproduction data obtained by the SAPHIR, SPring-8,
and CLAS groups are included into the calculations. The main resonance
contributions to the process stem from the $S_{11}(1650)$, $P_{13}(1720)$, and
$P_{13}(1900)$ states. The second bump at 1.9 GeV seen in the photoproduction
cross section data is described as a coherent sum of the resonance and
background contributions. The prediction for the beam polarization observable
is presented.",0505010v1
2005-05-03,Quasiparticle Resonances in the BCS Approach,"We present a simple method for calculating the energies and the widths of
quasiparticle resonant states. The method is based on BCS equations solved in
the Berggren representation. In this representation the quasiparticle
resonances are associated to the Gamow states of the mean field. The method is
illustrated for the case of neutron-rich nuclei $^{20-22}$O and $^{84}$Ni. It
is shown that the contribution of the continuum coupling to the pairing
correlations is small and largely dominated by a few resonant states close to
the continuum threshold.",0505011v1
2005-05-30,Target Normal Spin Asymmetry of the Elastic ep-Scattering at Resonance Energy,"We study the target normal spin asymmetry for the reaction $ep \to ep$ at
electron energy up to few GeV in the laboratory frame. The asymmetry is
proportional to the imaginary part of the reaction scattering amplitude. To
estimate the imaginary part of the amplitude we use the unitarity relation and
saturate the intermediate hadron states by the proton and resonances from the
first, second and third resonance regions. The resonance electromagnetic
transition amplitudes, needed to evaluate the asymmetry, are taken from
experiment.",0505079v2
2006-08-10,Time Delay and Time Advance in Resonance Theory,"We propose a theory of the resonance-antiresonance scattering process which
differs considerably from the classical one (the Breit-Wigner theory), which is
commonly used in the phenomenological analysis. Here both resonances and
antiresonances are described in terms of poles of the scattering amplitude: the
resonances by poles in the first quadrant while the antiresonances by poles in
the fourth quadrant of the complex angular momentum plane. The latter poles are
produced by non-local potentials, which derive from the Pauli exchange forces
acting among the nucleons or the quarks composing the colliding particles.",0608027v1
2006-10-19,Real-time Skyrme TDHF dynamics of giant resonances,"Nuclear dynamics of giant resonances are investigated with the real-time
Skyrme TDHF method. The TDHF equation is explicitly linearized with respect to
variation of single-particle wave functions. The time evolution of transition
densities are calculated for giant dipole resonances. The time-dependent
densities of protons and neutrons suggest that the dynamics of giant dipole
resonance in neutron-rich nuclei are significantly different from that in
stable nuclei with N=Z.",0610078v1
2001-01-08,Resonant-state solution of the Faddeev-Merkuriev integral equations for three-body systems with Coulomb-like potentials,"A novel method for calculating resonances in three-body Coulombic systems is
presented. The Faddeev-Merkuriev integral equations are solved by applying the
Coulomb-Sturmian separable expansion method. To show the power of the method we
calculate resonances of the three-$\alpha$ and the $H^-$ systems.",0101048v1
2001-06-13,Scattering of positronium from singly ionized helium and appearing resonances,"The coupled-channel model [Phys. Rev. A {\bf 59}, 363 (1999)] that yields
converged low-energy phase shifts, and exact binding and resonance features in
Ps-H [Phys. Rev. A {\bf 59}, 2058 (1999)] is applied to study Ps-He$^+$
scattering. Similar to PsH, resonances appear in the S-, P-, D-, etc partial
waves in the Ps-He$^+$ system but in both the singlet and triplet scattering
channels. The latter signifies possible Rydberg states of $e^+$ around singlet
and triplet helium. The S-wave singlet resonance at 2.79 eV agrees to that
predicted earlier in $e^+$-He entrance channel (energy difference 16.64 eV) at
19.27 eV [Chem. Phys. Lett. {\bf 262}, 460 (1996)].",0106041v1
2002-06-07,Boundary element method for resonances in dielectric microcavities,"A boundary element method based on a Green's function technique is introduced
to compute resonances with intermediate lifetimes in quasi-two-dimensional
dielectric cavities. It can be applied to single or several optical resonators
of arbitrary shape, including corners, for both TM and TE polarization. For
cavities with symmetries a symmetry reduction is described. The existence of
spurious solutions is discussed. The efficiency of the method is demonstrated
by calculating resonances in two coupled hexagonal cavities.",0206018v2
2002-07-16,Resonance structures in the multichannel quantum defect theory for the photofragmentation processes involving one closed and many open channels,"The transformation introduced by Giusti-Suzor and Fano and extended by
Lecomte and Ueda for the study of resonance structures in the multichannel
quantum defect theory (MQDT) is used to reformulate MQDT into the forms having
one-to-one correspondence with those in Fano's configuration mixing (CM) theory
of resonance for the photofragmentation processes involving one closed and many
open channels. The reformulation thus allows MQDT to have the full power of the
CM theory, still keeping its own strengths such as the fundamental description
of resonance phenomena without an assumption of the presence of a discrete
state as in CM.",0207061v1
2002-10-11,Hexagonal dielectric resonators and microcrystal lasers,"We study long-lived resonances (lowest-loss modes) in hexagonally shaped
dielectric resonators in order to gain insight into the physics of a class of
microcrystal lasers. Numerical results on resonance positions and lifetimes,
near-field intensity patterns, far-field emission patterns, and effects of
rounding of corners are presented. Most features are explained by a
semiclassical approximation based on pseudointegrable ray dynamics and boundary
waves. The semiclassical model is also relevant for other microlasers of
polygonal geometry.",0210052v2
2003-02-12,A Symbolic-Numerical Approach for the Sensitivity Analysis of Dielectric Resonator Sensors,"A theoretical model based on the transverse resonance method is proposed for
the description of cylindrical multilayer dielectric resonator sensors. From
this model, the resonant frequency and the sensitivities with respect to
geometrical and physical parameters are computed by means of a combination of
symbolic and numerical procedures. These are gathered together in a package in
view of the computer assisted design of this range of sensors. On this
occasion, a few design patterns for engineering applications are sketched.",0302040v1
2003-05-20,Tracking Simulations Near Half-Integer Resonance at PEP-II,"Beam-beam simulations predict that PEP-II luminosity can be increased by
operating the horizontal betatron tune near and above a half-integer resonance.
However, effects of the resonance and its synchrotron sidebands significantly
enhance betatron and chromatic perturbations which tend to reduce dynamic
aperture. In the study, chromatic variation of horizontal tune near the
resonance was minimized by optimizing local sextupoles in the Interaction
Region. Dynamic aperture was calculated using tracking simulations in LEGO
code. Dependence of dynamic aperture on the residual orbit, dispersion and
distortion of beta function after correction was investigated.",0305086v1
2003-07-10,One- and two-photon resonant spectroscopy of hydrogen and anti-hydrogen atoms in external electric fields,"The resonant spectra of hydrogen and anti-hydrogen atoms in the presence of
an external electric field are compared theoretically. It is shown that
nonresonant corrections to the transition frequency contain terms linear in the
electric field. The existence of these terms does not violate space and time
parity and leads to a difference in the resonant spectroscopic measurements for
hydrogen and anti-hydrogen atoms in an external electric field. The one-photon
1s-2p and the two-photon 1s-2s resonances are investigated.",0307056v1
2003-10-15,A relation between electromagnetically induced absorption resonances and nonlinear magneto-optics in Lambda-systems,"Recent work on Lambda-resonances in alkali metal vapors (E. Mikhailov, I.
Novikova, Yu. V. Rostovtsev, and G. R. Welch, quant-ph/0309171, and references
therein) investigated a type of electromagnetically induced absorption
resonance that occurs in three-level systems under specific conditions normally
associated with electromagnetically induced transparency. In this note, we show
that these resonances have a direct analog in nonlinear magneto-optics, and
support this conclusion with a calculation for a J=1->J'=0 system interacting
with a single nearly circularly polarized light field in the presence of a weak
longitudinal magnetic field.",0310066v3
2004-01-05,Capture into resonance in dynamics of a classical hydrogen atom in an oscillating electric field,"We consider a classical hydrogen atom in a linearly polarized electric field
of slow changing frequency. When the system passes through a resonance between
the driving frequency and the Kepler frequency of the electron's motion, a
capture into the resonance can occur. We study this phenomenon in the case of
2:1 resonance and show that the capture results in growth of the eccentricity
of the electron's orbit. The capture probability for various initial values of
the eccentricity is defined and calculated.",0401009v1
2005-06-10,Long range scattering resonances in strong-field seeking states of polar molecules,"We present first steps toward understanding the ultracold scattering
properties of polar molecules in strong electric field-seeking states. We have
found that the elastic cross section displays a quasi-regular set of potential
resonances as a function of the electric field, which potentially offers
intimate details about the inter-molecular interaction. We illustrate these
resonances in a ``toy'' model composed of pure dipoles, and in more physically
realistic systems. To analyze these resonances, we use a simple WKB
approximation to the eigenphase, which proves both reasonably accurate and
meaningful. A general treatment of the Stark effect and dipolar interactions is
also presented.",0506104v1
2005-12-22,"To the possibility of the ""slow light"" in the waveguides","The atoms moving within the waveguide with a critical frequency higher than
the resonant frequency of atoms are suggested for obtaining the ""slow light"".
Due to the absence of the resonant mode in the guide the atoms conserves
excitation and coherence. The speed of this mixed excitation (electromagnetic
field + moving atom) can be very low or even zero. The atoms moving within the
waveguide with a critical frequency higher than the resonant frequency of atoms
are suggested for obtaining the ""slow light"". Due to the absence of the
resonant mode in the guide the atoms conserves excitation and coherence. The
speed of this mixed excitation (electromagnetic field + moving atom) can be
very low or even zero.",0512214v1
2006-01-11,Properties of quasi-one-dimensional molecules with Feshbach resonance interaction,"Bound states and collisions of atoms with two-channel two-body interactions
in harmonic waveguides are analyzed. The closed-channel contributions to
two-atom bound states become dominant in the case of a weak resonance. At low
energies and values of the non-resonant scattering length the problem can be
approximated by a one-dimensional resonant model. Three-body problem becomes
nonintegrable and the properties of triatomic molecules become different from
those predicted by the integrable Lieb-Liniger-McGuire model.",0601073v2
2006-07-06,Low-distortion slow light using two absorption resonances,"We consider group delay and broadening using two strongly absorbing and
widely spaced resonances. We derive relations which show that very large pulse
bandwidths coupled with large group delays and small broadening can be
achieved. Unlike single resonance systems, the dispersive broadening dominates
the absorptive broadening which leads to a dramatic increase in the possible
group delay. We show that the double resonance systems are excellent candidates
for realizing all-optical delay lines. We report on an experiment which
achieved up to 50 pulse delays with 40% broadening.",0607055v1
2006-08-04,Tunable split-ring resonators for nonlinear negative-index metamaterials,"We study experimentally the dynamic tunability and self-induced nonlinearity
of split-ring resonators incorporating variable capacitance diodes. We
demonstrate that the eigenfrequencies of the resonators can be tuned over a
wide frequency range, and significantly, we show that the self-induced
nonlinear effects observed in the varactor-loaded split-ring resonator
structures can appear at relatively low power levels.",0608044v1
2006-12-20,Spin motion at and near orbital resonance in storage rings with Siberian Snakes. Part I: at orbital resonance,"Here, and in a sequel, we invoke the invariant spin field to provide an
in--depth study of spin motion at and near low order orbital resonances in a
simple model for the effects of vertical betatron motion in a storage ring with
Siberian Snakes. This leads to a clear understanding, within the model, of the
behaviour of the beam polarisation at and near so--called snake resonances in
proton storage rings.",0612194v1
2006-12-27,Calculation of three-body resonances using slow-variable discretization coupled with complex absorbing potential,"We developed a method to calculate positions and widths of three-body
resonances. The method combines the hyperspherical adiabatic approach, slow
variable discretization method (Tolstikhin et al., J. Phys. B: At. Mol. Opt.
Phys. 29, L389 (1996)), and a complex absorbing potential. The method can be
used to obtain resonances having short-range or long-range wave functions. In
particular, we applied the method to obtain very shallow three-body Efimov
resonances for a model system (Nielsen et al., Phys. Rev. A 66, 012705 (2002)).",0612242v3
1997-02-07,Resonance statistics in a microwave cavity with a thin antenna,"We propose a model for scattering in a flat resonator with a thin antenna.
The results are applied to rectangular microwave cavities. We compute the
resonance spacing distribution and show that it agrees well with experimental
data provided the antenna radius is much smaller than wavelengths of the
resonance wavefunctions.",9702022v1
1998-05-29,Interfering resonances in a quantum billiard,"We present a method for numerically obtaining the positions, widths and
wavefunctions of resonance states in a two dimensional billiard connected to a
waveguide. For a rectangular billiard, we study the dynamics of three resonance
poles lying separated from the other ones. As a function of increasing coupling
strength between the waveguide and the billiard two of the states become
trapped while the width of the third one continues to increase for all coupling
strengths. This behavior of the resonance poles is reflected in the time delay
function which can be studied experimentally.",9805087v1
1998-07-21,Single Molecule Magnetic Resonance and Quantum Computation,"It is proposed that nuclear (or electron) spins in a trapped molecule would
be well isolated from the environment and the state of each spin can be
measured by means of mechanical detection of magnetic resonance. Therefore
molecular traps make an entirely new approach possible for spin-resonance
quantum computation which can be conveniently scaled up. In the context of
magnetic resonance spectroscopy, a molecular trap promises the ultimate
sensitivity for single spin detection and an unprecedented spectral resolution
as well.",9807057v2
1999-01-01,Quantum slow motion,"We simulate the center of mass motion of cold atoms in a standing, amplitude
modulated, laser field as an example of a system that has a classical mixed
phase-space. We show a simple model to explain the momentum distribution of the
atoms taken after any distinct number of modulation cycles. The peaks
corresponding to a classical resonance move towards smaller velocities in
comparison to the velocities of the classical resonances. We explain this by
showing that, for a wave packet on the classical resonances, we can replace the
complicated dynamics in the quantum Liouville equation in phase-space by the
classical dynamics in a modified potential. Therefore we can describe the
quantum mechanical motion of a wave packet on a classical resonance by a purely
classical motion.",9901001v1
1999-03-29,Tunneling Proximity Resonances: Interplay between Symmetry and Dissipation,"We report the first observation of bound-state proximity resonances in
coupled dielectric resonators. The proximity resonances arise from the combined
action of symmetry and dissipation. We argue that the large ratio between the
widths is a distinctive signature of the multidimensional nature of the system.
Our experiments shed light on the properties of 2D tunneling in the presence of
a dissipative environment.",9903091v1
1999-05-28,Resonance flourescence in atomic coherent systems: spectral features,"We study resonance flourescence in a four level ladder system and illustrate
some novel features due to quantum interference and atomic coherence effects.
We find that under three photon resonant conditions, in some region of the
parameter space of the rabi frequencies $\Omega_1,\Omega_2,\Omega_3$, emission
is dominantly by the level 4 at the line center even though there is an almost
equal distribution of populations in all the levels. As one increases
$\Omega_3$ with $\Omega_1 and \Omega_2$ held fixed, the four level system
'dynamically collapses' to a two level system. The steady state populations and
the the resonance flourescence from all the levels provide adequate evidence to
this effect.",9905098v2
2000-01-26,Stochastic Resonance and Nonlinear Response by NMR Spectroscopy,"We revisit the phenomenon of quantum stochastic resonance in the regime of
validity of the Bloch equations. We find that a stochastic resonance behavior
in the steady-state response of the system is present whenever the
noise-induced relaxation dynamics can be characterized via a single relaxation
time scale. The picture is validated by a simple nuclear magnetic resonance
experiment in water.",0001095v1
2000-01-27,Quantum Stochastic Resonance in Electron Shelving,"Stochastic resonance shows that under some circumstances noise can enhance
the response of a system to a periodic force. While this effect has been
extensively investigated theoretically and demonstrated experimentally in
classical systems, there is complete lack of experimental evidence within the
purely quantum mechanical domain. Here we demonstrate that stochastic resonance
can be exhibited in a single ion and would be experimentally observable using
well mastered experimental techniques. We discuss the use of this scheme for
the detection of the frequency difference of two lasers to demonstrate that
stochastic resonance may have applications in precision measurements at the
quantum limit.",0001102v1
2000-03-09,Resonant cancellation of off-resonant effects in a multilevel qubit,"Off-resonant effects are a significant source of error in quantum
computation. This paper presents a group theoretic proof that off-resonant
transitions to the higher levels of a multilevel qubit can be completely
prevented in principle. This result can be generalized to prevent unwanted
transitions due to qubit-qubit interactions. A simple scheme exploiting dynamic
pulse control techniques is presented that can cancel transitions to higher
states to arbitrary accuracy.",0003034v2
2002-10-02,The role of the buildup oscillations on the speed of resonant tunneling diodes,"The fastest tunneling response in double barrier resonant structures is
investigated by considering explicit analytic solutions of the time dependent
Schr\""{o}dinger equation. For cutoff initial plane waves, we find that the
earliest tunneling events consist on the emission of a series of propagating
pulses of the probability density governed by the buildup oscillations in the
quantum well. We show that the fastest tunneling response comes from the
contribution of incident carriers at energies different from resonance, and
that its relevant time scale is given by $\tau_r=\pi \hbar /| E-\epsilon | $,
where $\epsilon $ is the resonance energy and $E$ is the incidence energy.",0210012v1
2003-01-17,Dynamics of two atoms coupled to a cavity field,"We investigate the interaction of two two-level atoms with a single mode
cavity field. One of the atoms is exactly at resonance with the field, while
the other is well far from resonance and hence is treated in the dispersive
limit. We find that the presence of the non-resonant atom produces a shift in
the Rabi frequency of the resonant atom, as if it was detuned from the field.
We focus on the discussion of the evolution of the state purity of each atom.",0301091v1
2003-04-12,Quantum State Control via Trap-induced Shape Resonance in Ultracold Atomic Collisions,"We investigate controlled collisions between trapped but separated ultracold
atoms. The interaction between atoms is treated self-consistently using an
energy-dependent delta-function pseudopotential model, whose validity we
establish. At a critical separation, a ""trap-induced shape resonance"" between a
molecular bound states and a vibrational eigenstate of the trap can occur. This
resonance leads to an avoided crossing in the eigenspectrum as a function of
separation. We investigate how this new resonance can be employed for quantum
control.",0304093v2
2003-10-13,Quantum theory of multimode fields: Applications to optical resonators,"A recently developed technique for the system--and--bath quantization of open
optical cavities is applied to three resonator geometries: A one dimensional
dielectric, a Fabry--Perot resonator, and a dielectric disk. The
system--and--bath Hamiltonian for these geometries is derived starting from
Maxwell's equations and employed to compute the electromagnetic fields, the
resonances, and the cavity gain factors. Exact agreement is found with standard
quantization methods based on a modes--of--the--universe description. Our
analysis provides a microscopic justification for the system--and--bath
quantization even in the regime of spectrally overlapping modes.",0310085v2
2003-11-11,"Time-delay, energy-continuum, and systematics of particles","Finding systematics in the mass-lifetime data for all the hadrons has been an
outstanding problem. In this work, we show that the product of mass and
lifetime for unstable particles is very well-approximated by \hbar 2^n/n where
n is an integer specific for a particle. In doing so, we have employed a
relation between time-delay and resonances. The energy-continuum has been
treated in a way to take advantage of Cantor's mathematical work on continuum.
Thus, even though the resonances are designated by complex energy variables
where ordering is not possible, in terms of stability, the index n labels these
resonances; larger the n, more stable a resonance is.",0311063v1
2003-12-30,Parametric Resonance in a Vibrating Cavity,"We present the study of parametric resonance in a one-dimensional cavity
based on the analysis of classical optical paths. The recursive formulas for
field energy are given. We separate the mechanism of particle production and
the resonance amplification of radiation. The production of photons is a purely
quantum effect described in terms of quantum anomalies in recursive formulas.
The resonance enhancement is a classical phenomenon of focusing and amplifying
beams of photons due to D\""{o}ppler effect.",0312219v1
2005-03-16,Calculation of resonances in the Coulomb three-body system with two disintegration channels in the adiabatic hyperspherical approach,"The method of calculation of the resonance characteristics is developed for
the metastable states of the Coulomb three-body (CTB) system with two
disintegration channels. The energy dependence of K-matrix in the resonance
region is calculated with the use of the stabilization method. Resonance
position and partial widths are obtained by fitting the numerically calculated
K(E)-matrix with the help of the generalized Breit-Wigner formula.",0503145v1
2005-10-11,"Weak and strong coupling regimes, vacuum Rabi splitting and nonstandard resonances","For two discrete-level quantum systems in interaction, we follow the
displacement in the complex plane of the eigen-energies of the compound system
when the spectrum of one of the two systems becomes continuous. These new
points are usually called resonances. This allows us to define and to calculate
a critical value of the coupling constant which separates two well-known
coupling regimes. We also give an example of these resonances for the hydrogen
atom coupled to the continuum of the states of the transverse electromagnetic
field in the vacuum. We justify that some resonances be neglected.",0510075v1
2005-11-03,Dephasing due to Intermode Coupling in Superconducting Stripline Resonators,"The nonlinearity exhibited by the kinetic inductance of a superconducting
stripline couples stripline resonator modes together in a manner suitable for
quantum non-demolition measurement of the number of photons in a given
resonator mode. Quantum non-demolition measurement is accomplished by
coherently driving another resonator mode, referred to as the detector mode,
and measuring its response. We show that the sensitivity of such a detection
scheme is directly related to the dephasing rate induced by such an intermode
coupling. We show that high sensitivity is expected when the detector mode is
driven into the nonlinear regime and operated close to a point where critical
slowing down occurs.",0511033v2
2006-01-23,Detuned Electromagnetically Induced Transparency in an $N$-type Atom,"The electromagnetically induced transparency (EIT) in an $N$ configuration is
studied under both resonant and off-resonant conditions. In a certain
off-resonant condition the dark state of the four level system, which is almost
the same as the resonant dark state in $\Lambda$ configuration, is rebuilt. The
actual system with damping is examined using optical Bloch equation, both
numerically and analytically. Based on this detuned dark state, some new
applications with frequency shifts can be realized.",0601153v2
2006-06-12,Prospects of employing superconducting stripline resonators for studying the dynamical Casimir effect experimentally,"We discuss the prospects of employing an NbN superconducting microwave
stripline resonator for studying the dynamical Casimir effect experimentally.
Preliminary experimental results, in which optical illumination is employed for
modulating the resonance frequencies of the resonator, show that such a system
is highly promising for this purpose. Moreover, we discuss the undesirable
effect of heating which results from the optical illumination, and show that
degradation in noise properties can be minimized by employing an appropriate
design.",0606099v3
2006-07-15,Continous Measurement of the Energy Eigenstates of a Nanomechanical Resonator without a Non-Demolition Probe,"We show that it is possible to perform a continuous measurement that
continually projects a nano-resonator into its energy eigenstates by employing
a linear coupling with a two-state system. This technique makes it possible to
perform a measurement that exposes the quantum nature of the resonator by
coupling it to a Cooper-pair Box and a superconducting transmission-line
resonator.",0607102v4
2006-07-20,Sub-ballistic behaviour of the Quantum Kicked Rotor,"We study the resonances of the quantum kicked rotor subjected to an
excitation that follows an aperiodic Fibonacci prescription. In such a case the
secondary resonances show a sub-ballistic behaviour like the quantum walk with
the same aperiodic prescription for the coin. The principal resonances maintain
the well-known ballistic behaviour. Then the parallelism previusly established
between the kicked rotor and the generalized quantum walk is retained only with
the secondary resonances.",0607146v2
2006-07-24,Description of resonances within the rigged Hilbert space,"The spectrum of a quantum system has in general bound, scattering and
resonant parts. The Hilbert space includes only the bound and scattering
spectra, and discards the resonances. One must therefore enlarge the Hilbert
space to a rigged Hilbert space, within which the physical bound, scattering
and resonance spectra are included on the same footing. In these lectures, I
will explain how this is done.",0607168v1
2006-08-26,Relaxation- and Decoherence-free subspaces in networks of weakly and strongly coupled resonators,"We consider a network of interacting resonators and analyze the physical
ingredients that enable the emergence of relaxation-free and decoherence-free
subspaces. We investigate two different situations: i) when the whole network
interacts with a common reservoir and ii) when each resonator, strongly coupled
to each other, interacts with its own reservoir. Our main result is that both
subspaces are generated when all the resonators couple with the same group of
reservoir modes, thus building up a correlation (among these modes), which has
the potential to shield particular network states against relaxation and/or
decoherence.",0608204v1
2007-05-07,"The Fermi-Pasta-Ulam problem: periodic orbits, normal forms and resonance overlap criteria","Fermi, Pasta and Ulam observed, that the excitation of a low frequency normal
mode in a nonlinear acoustic chain leads to localization in normal mode space
on large time scales. Fast equipartition (and thus complete delocalization) in
the Fermi-Pasta-Ulam chain is restored if relevant intensive control parameters
exceed certain threshold values. We compare recent results on periodic orbits
(in the localization regime) and resonant normal forms (in a weak
delocalization regime), and relate them to various resonance overlap criteria.
We show that the approaches quantitatively agree in their estimate of the
localization-delocalization threshold. A key ingredient for this transition are
resonances of overtones.",0705.0804v1
2007-06-11,Resonances of the Quantum $δ$-Kicked Accelerator,"We report the observation of high order resonances of the quantum
$\delta$-kicked accelerator using a BEC kicked by a standing wave of light. The
signature of these resonances is the existence of quantum accelerator modes.
For the first time quantum accelerator modes were seen near 1/4 and 1/3 of the
Talbot time. Using a BEC enabled us to study the detailed structure of the
modes and resonances which are related to the fractional Talbot effect. We
present a general theory for this system and apply it to predict the behavior
of the accelerator modes.",0706.1587v1
2007-06-15,A widely tunable parametric amplifier based on a SQUID array resonator,"We create a Josephson parametric amplifier from a transmission line resonator
whose inner conductor is made from a series SQUID array. By changing the
magnetic flux through the SQUID loops, we are able to adjust the circuit's
resonance frequency and, consenquently, the center of the amplified band,
between 4 and 7.8 GHz. We observe that the amplifier has gains as large as 28
dB and infer that it adds less than twice the input vacuum noise.",0706.2373v1
2007-06-28,An optical surface resonance may render photonic crystals ineffective,"In this work we identify and study the presence of extremely intense surface
resonances that frustrate the coupling of photons into a photonic crystal over
crucial energy ranges. The practical utility of photonic crystals demands the
capability to exchange photons with the external medium, therefore, it is
essential to understand the cause of these surface resonances and a route to
their elimination. We demonstrate that by modifying the surface geometry it is
possible to tune the optical response or eliminate the resonances to enable
full exploitation of the photonic crystal.",0706.4321v1
2007-07-25,Energy Measurements and Preparation of Canonical Phase States of a Nano-Mechanical Resonator,"We show that a continuous quantum non-demolition measurement of the energy of
a nanomechanical resonator can be achieved by monitoring the resonator with a
quantum point contact via a Cooper-pair box. This technique can further be used
to prepare highly non-classical states of two resonators, such as canonical
phase-reference states, and so-called ""noon"" states.",0707.3803v2
2007-08-06,Microstrip resonator for microwaves with controllable polarization,"In this work the authors implemented a resonator based upon microstrip
cavities that permits the generation of microwaves with arbitrary polarization.
Design, simulation, and implementation of the resonators were performed using
standard printed circuit boards. The electric field distribution was mapped
using a scanning probe cavity perturbation technique. Electron spin resonance
using a standard marker was carried out in order to verify the polarization
control from linear to circular.",0708.0777v2
2007-08-12,Resonance phenomena in discrete systems with bichromatic input signal,"We undertake a detailed numerical study of the twin phenomena of stochastic
and vibrational resonance in a discrete model system in the presence of
bichromatic input signal. A two parameter cubic map is used as the model that
combines the features of both bistable and threshold settings. Our analysis
brings out several interesting results, such as, the existence of a cross over
behaviour from vibrational to stochastic resonance and the possibility of using
stochastic resonance as a filter for the selective detection/transmission of
the component frequencies in a composite signal. The study also reveals a
fundamental difference between the bistable and threshold mechanisms with
respect to amplification of a multi signal input.",0708.1594v1
2007-09-25,Coexisting stochastic and coherence resonance in a mean-field dynamo model for Earth's magnetic field reversals,"Using a spherical symmetric mean field alpha^2-dynamo model for Earth's
magnetic field reversals, we show the coexistence of the noise-induced
phenomena coherence resonance and stochastic resonance. Stochastic resonance
has been recently invoked to explain the 100 kyr periodicity in the
distribution of the residence time between reversals. The comparison of the
resulting residence time distribution with the paleomagnetic one allows for
some estimate of the effective diffusion time of the Earth's core which may be
100 kyr or slightly below rather than 200 kyr as it would result from the
molecular resistivity.",0709.3932v1
2007-10-03,Nuclear Tuning and Detuning of the Electron Spin Resonance in a Quantum Dot,"We study nuclear spin dynamics in a quantum dot close to the conditions of
electron spin resonance. We show that at small frequency mismatch the nuclear
field detunes the resonance. Remarkably, at larger frequency mismatch its
effect is opposite: The nuclear system is bistable, and in one of the stable
states the field accurately tunes the electron spin splitting to resonance. In
this state the nuclear field fluctuations are strongly suppressed and nuclear
spin relaxation is accelerated.",0710.0750v2
2007-10-10,Fano Resonances in Stubbed Quantum Waveguides with Impurities,"We consider T--shaped, two--dimensional quantum waveguides containing
attractive or repulsive impurities with a smooth, realistic shape, and study
how the resonance behavior of the total conductance depends upon the strength
of the defect potential and the geometry of the device. The resonance
parameters are determined locating the relevant S-matrix poles in the Riemann
energy surface. The total scattering operator is obtained from the S-matrices
of the various constituent segments of the device through the *-product
composition rule. This allows for a numerically stable evaluation of the
scattering matrix and of the resonance parameters.",0710.1943v1
2007-10-10,Resonances in twisted quantum waveguides,"In this paper we consider embedded eigenvalues of a Schroedinger Hamiltonian
in a waveguide induced by a symmetric perturbation. It is shown that these
eigenvalues become unstable and turn into resonances after twisting of the
waveguide. The perturbative expansion of the resonance width is calculated for
weakly twisted waveguides and the influence of the twist on resonances in a
concrete model is discussed in detail.",0710.1987v1
2007-11-26,Resonances in chiral unitary approaches,"The extension of chiral theories to the description of resonances, via the
incorporation of unitarity in coupled channels, has provided us with a new
theoretical perspective on the nature of some of the observed excited hadrons.
In this contribution some of the early achievements in the field of baryonic
resonances are reviewed, the recent evidence of the two-pole nature of the
Lambda(1405) is discussed and results on charmed baryon resonances are
presented.",0711.4042v1
2007-11-29,On the theory of resonances in non-relativistic QED and related models,"We study the mathematical theory of quantum resonances in the standard model
of non-relativistic QED and in Nelson's model. In particular, we estimate the
survival probability of metastable states corresponding to quantum resonances
and relate the resonances to poles of an analytic continuation of matrix
elements of the resolvent of the quantum Hamiltonian.",0711.4708v2
2007-12-23,The Delta(1232) Resonance in Chiral Effective Field Theory,"I discuss the problem of formulating the baryon chiral perturbation theory
($\chi$PT) in the presence of a light resonance, such as the $\Delta(1232)$,
the lightest nucleon resonance. It is shown how to extend the power counting of
$\chi$PT to correctly account for the resonant contributions. Recent
applications of the resulting chiral effective-field theory to the description
of pion production reactions in $\Delta$-resonance region are briefly reviewed.",0712.3919v1
2007-12-28,Hybrid-impurity resonances in anisotropic quantum dots,"The absorption of electromagnetic radiation of an anisotropic quantum dot is
theoretically investigated taking into account the processes associated with
simultaneous scattering from ionized impurities. It is shown that the
scattering of electrons by impurities leads to the resonance absorption even if
we have only one impurity in the quantum dot. Explicit formula is derived for
the absorption coefficient. The positions of the resonances peaks are found.
The effects of external magnetic field on the resonance absorption are studied.",0712.4324v2
2008-01-04,The Possibility of Checking the Equivalence Principle in a Null Gravitational Redshift by a Two-Resonator Laser System,"A scheme of an optical detector is proposed for checking Einsteins
equivalence principle (EEP) in a null gravitational redshift experiment and for
testing methods for calculating the length of a resonator in a weak variable
gravitational field by recording the variations of the difference frequency of
resonators caused by lunisolar variations of the geopotential in a double or a
two-resonator laser system.",0801.0643v1
2008-01-05,Information on the structure of the a1 from tau decay,"The decay $\tau\to \pi\pi\pi\nu$ is analysed using different methods to
account for the resonance structure, which is usually ascribed to the a1. One
scenario is based on the recently developed techniques to generate axial-vector
resonances dynamically, whereas in a second calculation the a1 is introduced as
an explicit resonance. We investigate the influence of different assumptions on
the result. In the molecule scenario the spectral function is described
surprisingly well by adjusting only one free parameter. This result can be
systematically improved by adding higher order corrections to the iterated
Weinberg-Tomozawa interaction. Treating the a1 as an explicit resonance on the
other hand leads to peculiar properties.",0801.0814v1
2008-01-14,Miniaturization and control of split ring structures from an analytic solution of their resonance,"We derived simple polynomial equations to determine the entire resonance
spectra of split ring structures. For double stacking split rings made with
flat wires, we showed that the resonance frequency depends linearly on the
ring-ring separation. In particular, we found that the wavelength of the lowest
resonance mode can be made as large as the geometrical size of the ring for
realistic experimental conditions, whereas for current systems this ratio is of
the order of 10. Finite-difference-time-domain simulations on realistic
structures verified the analytic predictions.",0801.2135v1
2008-02-18,Resonance sum rules from large $N_C$ and partial wave dispersive analysis,"Combining large $N_C$ techniques and partial wave dispersion theory to
analyze the $\pi\pi$ scattering, without relying on any explicit resonance
lagrangian, some interesting results are derived: (a) a general KSRF relation
including the scalar meson contribution; (b) a new relation between resonance
couplings, with which we have made an intensive analysis in several specific
models; (c) low energy constants in chiral perturbation theory related with
$\pi\pi$ scattering in terms of the mass and decay width of resonances.",0802.2530v1
2008-04-01,Optical combs with a crystalline whispering gallery mode resonator,"We report on the experimental demonstration of a tunable monolithic optical
frequency comb generator. The device is based on the four-wave mixing in a
crystalline calcium fluoride whispering gallery mode resonator. The frequency
spacing of the comb is given by an integer number of the free spectral range of
the resonator. We select the desired number by tuning the pumping laser
frequency with respect to the corresponding resonator mode. We also observe
interacting optical combs and high-frequency hyperparametric oscillation,
depending on the experimental conditions. A potential application of the comb
for generating narrowband frequency microwave signals is demonstrated.",0804.0263v1
2008-04-07,Resonant Spin Polarization and Hall Effects in a Two-Dimensional Electron Gas,"We have studied transport properties in a two-dimensional electron gas with
equal Rashba and Dresselhaus spin-orbit interactions under a perpendicular
magnetic field. By employing the exact solution for this system, we found
resonant charge and spin Hall conductances at a certain magnetic field, where
all the nearest-neighboring Landau levels cross. Near this value of magnetic
field, there exists a resonant spin polarization, which can also induce
resonant charge and spin Hall effects.",0804.1138v1
2008-04-14,On the observation of the spin resonance in superconducting CeCoIn_5,"Recent observation of a resonance spin excitation at (1/2,1/2,1/2) in the
superconducting state of CeCoIn_5 [C. Stock et al., Phys. Rev. Lett. {\bf 100}
087001 (2008)] was interpreted as an evidence for d_{x^2-y^2} gap symmetry, by
analogy with the cuprates. This is true if the resonance is a spin exciton. We
argue that such description is undermined by the three-dimensionality of
CeCoIn_5. We show that in 3D systems the excitonic resonance only emerges at
strong coupling, and is weak. We argue in favor of the alternative, magnon
scenario, which does not require a d_{x^2-y^2} gap.",0804.2217v1
2008-04-30,Quantum Theory of Transmission Line Resonator-Assisted Cooling of a Micromechanical Resonator,"We propose a quantum description of the cooling of a micromechanical flexural
oscillator by a one-dimensional transmission line resonator via a force that
resembles cavity radiation pressure. The mechanical oscillator is capacitively
coupled to the central conductor of the transmission line resonator. At the
optimal point, the micromechanical oscillator can be cooled close to the ground
state, and the cooling can be measured by homodyne detection of the output
microwave signal.",0804.4766v2
2008-05-19,Magnetic field tuning of coplanar waveguide resonators,"We describe measurements on microwave coplanar resonators designed for
quantum bit experiments. Resonators have been patterned onto sapphire and
silicon substrates, and quality factors in excess of a million have been
observed. The resonant frequency shows a high sensitivity to magnetic field
applied perpendicular to the plane of the film, with a quadratic dependence for
the fundamental, second and third harmonics. Frequency shift of hundreds of
linewidths can be obtained.",0805.2818v2
2008-05-19,Vibrational coherence in electron spin resonance in nanoscale oscillators,"We study a scheme for electrical detection, using electron spin resonance, of
coherent vibrations in a molecular single electron level trapped near a
conduction channel. Both equilibrium spin-currents and non-equilibrium spin-
and charge currents are investigated. Inelastic side-band anti-resonances
corresponding to the vibrational modes appear in the electron spin resonance
spectrum.",0805.2919v2
2008-05-28,Atomic multiplet calculation of 3d_{5/2} -> 4f resonant x-ray diffraction from Ho metal,"We compare for Ho metal the x-ray absorption spectrum and the resonant soft
x-ray diffraction spectra obtained at the $3d_{5/2} \to 4f$ ($M_5$) resonance
for the magnetic 1st and 2nd order diffraction peaks $(0,0,\tau)$ and
$(0,0,2\tau)$ with the result of an atomic multiplet calculation. We find a
good agreement between experiment and simulation giving evidence that this kind
of simulation is well suited to quantitatively analyze resonant soft x-ray
diffraction data from correlated electron systems.",0805.4341v1
2008-06-17,Resonant low-energy electron scattering on short-range impurities in graphene,"Resonant scattering of electrons with low energies (as compared to the
bandwidth) on a single neutral short-range impurity in graphene is analyzed
theoretically, taking into account the valley degeneracy. Resonances
dramatically increase the scattering cross-section and introduce a strong
energy dependence. Analysis of the tight-binding model shows that resonant
scattering is typical for generic impurities as long as they are sufficiently
strong (the potential is of the order of the electron bandwidth or higher).",0806.2785v4
2008-06-19,Coherent resonant Ka-band photonic microwave receiver,"We propose theoretically and demonstrate experimentally a coherent microwave
photonic receiver operating at 35 GHz carrier frequency. The device is based on
a lithium niobate or lithium tantalate optical whispering gallery mode
resonator coupled to a microwave strip line resonator. Microwave local
oscillator is fed into the microwave resonator along with the microwave signal.
We show that the sensitivity of this receiver significantly exceeds the
sensitivity of the incoherent quadratic receiver based on the same technology.
The coherent receiver can possess a dynamic range in excess of 100 dB in 5 MHz
band if a low noise laser is utilized.",0806.3239v1
2008-06-22,Synchonisation of Resonances with Thresholds,"The mechanism by which a resonance may be attracted to a sharp threshold is
described with several examples. It involves a threshold cusp interfering
constructively with either or both (i) a resonance produced via confinement,
(ii) attractive t- and u-channel exchanges. More generally, it is suggested
that resonances are eigenstates generated by mixing between confined states and
long-range meson and baryon exchanges.",0806.3566v2
2008-06-25,Beam-Beam Resonances for Different Collision Schemes,"One of the main advantages of proposed by P. Raimondi ""Crab Waist"" collision
scheme is a strong suppression of betatron resonances excited by beam-beam
interaction. Some qualitative explanations with numerical examples, describing
beam-beam resonances for different collision schemes, were given in
arXiv:physics/0702033. This paper can be considered as an ""appendix""
(additional illustration) to that one. We performed a number of full 2D
betatron tune scans (beam-beam simulations) for different collision schemes, so
one can easily see how the beam-beam resonances appear and disappear, depending
on the colliding conditions.",0806.4070v1
2008-08-22,Detecting quantum-coherent nanomechanical oscillations using the current-noise spectrum of a double quantum dot,"We consider a nanomechanical resonator coupled to a double quantum dot. We
demonstrate how the finite-frequency current noise spectrum through the double
quantum dot can be used to distinguish classical and quantum behaviour in the
nearby nano-electromechanical resonator. We also show how the full frequency
current noise spectrum gives important information on the combined double
quantum dot-resonator energy spectrum. Finally, we point out regimes where the
quantum state of the resonator becomes squeezed, and also examine the
cross-correlated electron-phonon current noise.",0808.3034v2
2008-08-26,Chaotic Scattering in the Regime of Weakly Overlapping Resonances,"We measure the transmission and reflection amplitudes of microwaves in a
resonator coupled to two antennas at room temperature in the regime of weakly
overlapping resonances and in a frequency range of 3 to 16 GHz. Below 10.1 GHz
the resonator simulates a chaotic quantum system. The distribution of the
elements of the scattering matrix S is not Gaussian. The Fourier coefficients
of S are used for a best fit of the autocorrelation function if S to a
theoretical expression based on random--matrix theory. We find very good
agreement below but not above 10.1 GHz.",0808.3503v1
2008-09-15,Resonance phenomena in ultracold dipole-dipole scattering,"Elastic scattering resonances occurring in ultracold collisions of either
bosonic or fermionic polar molecules are investigated. The Born-Oppenheimer
adiabatic representation of the two-bodydynamics provides both a qualitative
classification scheme and a quantitative WKB quantization condition that
predicts several sequences of resonant states. It is found that the
near-threshold energy dependence of ultracold collision cross sections varies
significantly with the particle exchange symmetry, with bosonic systems showing
much smoother energy variations than their fermionic counterparts. Resonant
variations of the angular distributions in ultracold collisions are also
described.",0809.2566v1
2008-10-06,The resonance amplitude associated with the Gamow states,"The Gamow states describe the quasinormal modes of quantum systems. It is
shown that the resonance amplitude associated with the Gamow states is given by
the complex delta function. It is also shown that under the near-resonance
approximation of neglecting the lower bound of the energy, such resonance
amplitude becomes the Breit-Wigner amplitude. This result establishes the
precise connection between the Gamow states, Nakanishi's complex delta function
and the Breit-Wigner amplitude. In addition, this result provides another
theoretical basis for the phenomenological fact that the almost-Lorentzian
peaks in cross sections are produced by intermediate, unstable particles.",0810.0876v1
2008-10-20,Current correlators and form factors in the resonance region,"Within Resonance Chiral Theory and in the context of QCD current correlators
at next-to-leading order in 1/N(C), we have analyzed the two-body form factors
which include resonances as a final state . The short-distance constraints have
been studied. One of the main motivations is the estimation of the chiral
low-energy constants at subleading order, that is, keeping full control of the
renormalization scale dependence. As an application we show the resonance
estimation of some coupling, L(10)(mu_0)=(-4.4 \pm 0.9)10^{-3} and
C(87)(mu_0)=(3.1 \pm 1.1)10^{-5}.",0810.3592v1
2008-10-20,Pinning mode resonances of 2D electron stripe phases: Effect of in-plane magnetic field,"We study the anisotropic pinning-mode resonances in the rf conductivity
spectra of the stripe phase of 2D electron systems (2DES) around Landau level
filling 9/2, in the presence of an in-plane magnetic field, B_ip. The
polarization along which the resonance is observed switches as B_ip is applied,
consistent with the reorientation of the stripes. The resonance frequency, a
measure of the pinning interaction between the 2DES and disorder, increases
with B_ip. The magnitude of this increase indicates that disorder interaction
is playing an important role in determining the stripe orientation.",0810.3704v1
2008-11-11,The spectrum of charmonium in the Resonance-Spectrum Expansion,"We argue that the resonance-like structures Y(4260)
(arXiv:hep-ex/0506081,arXiv:0707.2541), Y(4360), Y(4660) (arXiv:0707.3699) and
Y(4635) (arXiv:0807.4458), which were recently reported to have been observed
in experiment, are non-resonant manifestations of the Regge zeros that appear
in the production amplitude of the Resonance-Spectrum Expansion. Charmonium
c-cbar states are visible on the slopes of these enhancements.",0811.1755v1
2008-12-12,Force-detected nuclear double resonance between statistical spin polarizations,"We demonstrate nuclear double resonance for nanometer-scale volumes of spins
where random fluctuations rather than Boltzmann polarization dominate. When the
Hartmann-Hahn condition is met in a cross-polarization experiment, flip-flops
occur between two species of spins and their fluctuations become coupled. We
use magnetic resonance force microscopy to measure this effect between 1H and
13C spins in 13C-enriched stearic acid. The development of a cross-polarization
technique for statistical ensembles adds an important tool for generating
chemical contrast in nanometer-scale magnetic resonance.",0812.2274v1
2008-12-15,Lifetime statistics in chaotic dielectric microresonators,"We discuss the statistical properties of lifetimes of electromagnetic
eigenmodes in dielectric microresonators with fully chaotic ray dynamics. Using
the example of a resonator of stadium geometry, we find that a recently
proposed random-matrix model very well describes the lifetime statistics of
long-lived resonances, provided that two effective parameters are appropriately
renormalized. This renormalization is linked to the formation of anomalously
short-lived resonances, a mechanism also known from the fractal Weyl law and
the resonance trapping phenomenon.",0812.2823v1
2009-01-08,Resonances for Schrodinger operators with compactly supported potentials,"We describe the generic behavior of the resonance counting function for a
Schr\""odinger operator with a bounded, compactly-supported real or complex
valued potential in $d \geq 1$ dimensions. This note contains a sketch of the
proof of our main results \cite{ch-hi1,ch-hi2} that generically the order of
growth of the resonance counting function is the maximal value $d$ in the odd
dimensional case, and that it is the maximal value $d$ on each nonphysical
sheet of the logarithmic Riemann surface in the even dimensional case. We
include a review of previous results concerning the resonance counting
functions for Schr\""odinger operators with compactly-supported potentials.",0901.1103v1
2009-01-30,Ultra-high-Q tunable whispering-gallery-mode microresonator,"Typical microresonators exhibit a large frequency spacing between resonances
and a limited tunability. This impedes their use in a large class of
applications which require a resonance of the microcavity to coincide with a
predetermined frequency. Here, we experimentally overcome this limitation with
highly prolate-shaped whispering-gallery-mode ""bottle microresonators""
fabricated from standard optical glass fibers. Our resonators combine an
ultra-high quality factor of 360 million, a small mode volume, and near
lossless fibre coupling, characteristic of whispering-gallery-mode resonators,
with a simple and customizable mode structure enabling full tunability.",0901.4921v2
2009-02-16,Phenomena of Time Resonances Explosions for the Compound-Clot Decays in High-Energy Nuclear Reactions,"The phenomenon of time resonances (or explosions) can explain the exponential
reduction of the energy, which is accompanied for the certain degree by slight
fluctuations under some conditions in the range of the energy strongly
overlapped compound-resonances. These resonant explosions correspond to
formation of several highly-exited non-exponentially decaying nuclear clots
(partial compound nuclei consisting of several small groups of projectile
nucleons and targets). This paper is a continuation and expansion of
theoretical authors' work, which is a more general self-consistent version of
the time-evolution approach in comparison with the traditional Izumo-Araseki
time compound-nucleus model.",0902.2665v1
2009-03-13,Di-Electrons from Resonances in Nucleon-Nucleon Collisions,"The contribution of the low-lying nucleon resonances $P_{33}(1232)$,
$P_{11}(1440)$ $D_{13}(1520)$ and $S_{11}(1535)$ to the invariant mass spectra
of di-electrons stemming from the exclusive processes $pp\to pp e^+e^-$ and
$pn\to pn e^+e^-$ is investigated within a fully covariant and gauge invariant
diagrammatical approach. We employ, within the one-boson exchange
approximation, effective nucleon-meson interactions including the exchange
mesons $\pi$, $\eta$, $\sigma$, $\omega$ and $\rho$ as well as excitations and
radiative decays of the above low-lying nucleon resonances. The total
contribution of these resonances is dominant, however, bremsstrahlung processes
in $pp$ and, in particular, $pn$ collisions at beam energies of 1 - 2 GeV are
still significant in certain phase space regions.",0903.2466v1
2009-03-27,Transmission resonance in a composite plasmonic structure,"The design, fabrication, and optical properties of a composite plasmonic
structure, a two-dimentional array of split-ring resonators inserted into
periodic square holes of a metal film, have been reported. A new type of
transmission resonance, which makes a significant difference from the
conventional peaks, has been suggested both theoretically and experimentally.
To understand this effect, a mechanism of ring- resonance induced dipole
emission is proposed.",0903.4780v1
2009-04-01,About Quartz Crystal Resonator Noise: Recent Study,"The first step, before investigating physical origins of noise in resonators,
is to investigate correlations between external measurement parameters and the
resonator noise. Tests and measurements are mainly performed on an advanced
phase noise measurement system, recently set up. The resonator noise is
examined as a function of the sensitivity to the drive level, the temperature
operating point and the tuning capacitor.",0904.0137v1
2009-05-02,On the Inverse Resonance Problem for Schrodinger Operators,"We consider Schr\""odinger operators on [0,\infty) with compactly supported,
possibly complex-valued potentials in L^1([0,\infty)). It is known (at least in
the case of a real-valued potential) that the location of eigenvalues and
resonances determines the potential uniquely. From the physical point of view
one expects that large resonances are increasingly insignificant for the
reconstruction of the potential from the data. In this paper we prove the
validity of this statement, i.e., we show conditional stability for finite
data. As a by-product we also obtain a uniqueness result for the inverse
resonance problem for complex-valued potentials.",0905.0171v2
2009-05-04,Dynamics near the p : -q Resonance,"We study the dynamics near the truncated p : +/- q resonant Hamiltonian
equilibrium for p, q coprime. The critical values of the momentum map of the
Liouville integrable system are found. The three basic objects reduced period,
rotation number, and non-trivial action for the leading order dynamics are
computed in terms of complete hyperelliptic integrals. A relation between the
three functions that can be interpreted as a decomposition of the rotation
number into geometric and dynamic phase is found. Using this relation we show
that the p : -q resonance has fractional monodromy. Finally we prove that near
the origin of the 1 : -q resonance the twist vanishes.",0905.0334v1
2009-05-04,Berry Phase Coupling and the Cuprate Neutron Scattering Resonance,"We examine the influence of coupling between particle-hole and
particle-particle spin fluctuations on the inelastic neutron scattering
resonance (INSR) in cuprate superconductors in both weak and strong interaction
limits. For weak-interactions in the particle-hole channel, we find that the
interchannel coupling can eliminate the resonance. For strong interactions
which drive the system close to a $\bm{Q}=(\pi,\pi)$ magnetic instablity, the
resonance frequency always approaches zero but its value is influenced by the
interchannel coupling. We comment on constraints imposed on cuprate physics by
the INSR phenomenology, and a comparison between the cuprates and the
newly-discovered iron pnictide superconductors is discussed.",0905.0464v1
2009-05-05,Decoherence without classicality in the resonant quantum kicked rotor,"We study the quantum kicked rotor in resonance subjected to an unitary noise
defined through Kraus operators, we show that this type of decoherence does
not, in general, lead to the classical diffusive behavior. We find exact
analytical expressions for the density matrix and the variance in the primary
resonances. The variance does not loose its ballistic behavior, however the
coherence decays as a power law. The secondary resonances are treated
numerically, obtaining a power-law decay for the variance and an exponential
law decay for the coherence.",0905.0703v2
2009-05-18,Fractional photon-assisted tunneling for Bose-Einstein condensates in a double well,"Half-integer photon-resonances in a periodically shaken double well are
investigated on the level of the N-particle quantum dynamics. Contrary to
non-linear mean-field equations, the linear N-particle Schrodinger equation
does not contain any non-linearity which could be the origin of such
resonances. Nevertheless, analytic calculations on the N-particle level explain
why such resonances can be observed even for particle numbers as low as N = 2.
These calculations also demonstrate why fractional photon resonances are not
restricted to half-integer values.",0905.2838v1
2009-05-27,System size stochastic resonance in driven finite arrays of coupled bistable elements,"The global response to weak time periodic forces of an array of noisy,
coupled nonlinear systems might show a nonmonotonic dependence on the number of
units in the array. This effect has been termed system size stochastic
resonance. In this paper, we analyze the nonmonotonic dependence on the system
size of the signal-to-noise ratio of a collective variable characterizing a
finite array of one-dimensional globally coupled bistable elements. By contrast
with the conventional nonmonotonic dependence with the strength of the noise
(stochastic resonance), system size stochastic resonance is found to be
restricted to some regions in parameter space.",0905.4470v1
2009-06-01,On the φ(1020)f_0(980) S-wave scattering and the Y(2175) resonance,"We have studied the \phi(1020)f_0(980) S-wave scattering at energies around
threshold employing chiral Lagrangians coupled to vector mesons through minimal
coupling. The interaction kernel is obtained by considering the f_0(980) as a
K\bar{K} bound state. The Y(2175) resonance is generated in this approach by
the self-interactions between the \phi(1020) and the f_0(980) resonances. We
are able to describe the e^+e^-\to \phi(1020)f_0(980) recent scattering data to
test experimentally our scattering amplitudes, concluding that the Y(2175)
resonance has a large \phi(1020)f_0(980) meson-meson component.",0906.0222v1
2009-06-17,Tunable ultranarrow linewidth of cavity induced by interacting dark resonances,"A scheme for getting a tunable ultranarrow linewidth of a cavity due to an
embedded four-level atomic medium with double-dark resonances is proposed. It
is shown that the steep dispersion induced by double-dark resonances in the
transparency window leads to the ultranarrow transmission peak. Compared with
the case of a single-dark-resonance system, the linewidth can be narrowed even
by one order under proper conditions. Furthermore, the position of the
ultranarrow peak can be engineered by varying the intensity and detuning of the
control field.",0906.3190v1
2009-06-20,Dynamically generated resonances,"In this talk I report on recent work related to the dynamical generation of
baryonic resonances, some made up from pseudoscalar meson-baryon, others from
vector meson-baryon and a third type from two meson-one baryon systems. We can
establish a correspondence with known baryonic resonances, reinforcing
conclusions previously drawn and bringing new light on the nature of some
baryonic resonances of higher mass.",0906.3801v1
2009-07-02,Damping and decoherence of a nanomechanical resonator due to a few two level systems,"We consider a quantum model of a nanomechanical flexing beam resonator
interacting with a bath comprising a few damped tunneling two level systems
(TLS's). In contrast with a resonator interacting bilinearly with an ohmic free
oscillator bath (modeling clamping loss, for example), the mechanical resonator
damping is amplitude dependent, while the decoherence of quantum superpositions
of mechanical position states depends only weakly on their spatial separation.",0907.0431v1
2009-07-15,Acoustic characterization of Hofstadter butterfly with resonant scatterers,"We are interested in the experimental characterization of the Hofstadter
butterfly by means of acoustical waves. The transmission of an acoustic pulse
through an array of 60 variable and resonant scatterers periodically distribued
along a waveguide is studied. An arbitrary scattering arrangement is realized
by using the variable length of each resonator cavity. For a periodic
modulation, the structures of forbidden bands of the transmission reproduce the
Hofstadter butterfly. We compare experimental, analytical, and computational
realizations of the Hofstadter butterfly and we show the influence of the
resonances of the scatterers on the structure of the butterfly.",0907.2517v1
2009-07-16,A multi-spectral and polarization-selective surface-plasmon resonant mid-infrared detector,"We demonstrate a multi-spectral polarization sensitive mid-infrared
dots-in-a-well (DWELL) photodetector utilizing surface-plasmonic resonant
elements, with tailorable frequency response and polarization selectivity. The
resonant responsivity of the surface-plasmon detector shows an enhancement of
up to 5 times that of an unpatterned control detector. As the plasmonic
resonator involves only surface patterning of the top metal contact, this
method is independent of light-absorbing material and can easily be integrated
with current focal plane array processing for imaging applications.",0907.2945v1
2009-07-21,Non-resonant wave front reversal of spin waves used for microwave signal processing,"It is demonstrated that non-resonant wave front reversal (WFR) of spin-wave
pulses caused by pulsed parametric pumping can be effectively used for
microwave signal processing. When the frequency band of signal amplification by
pumping is narrower than the spectral width of the signal, the non-resonant WFR
can be used for the analysis of the signal spectrum. In the opposite case the
non-resonant WFR can be used for active (with amplification) filtering of the
input signal.",0907.3652v1
2009-08-03,Imaging-based Parametric Resonance in an Optical Dipole Atom Trap,"We report sensitive detection of parametric resonances in a high-density
sample of ultracold $^{87}Rb$ atoms confined to a far-off-resonance optical
dipole trap. Fluorescence imaging of the expanded ultracold atom cloud after a
period of parametric excitation shows significant modification of the atomic
spatial distribution and has high sensitivity compared with traditional
measurements of parametrically-driven trap loss. Using this approach, a
significant shift of the parametric resonance frequency is observed, and
attributed to the anharmonic shape of the dipole trap potential.",0908.0263v2
2009-08-21,Nonlinearity-induced broadening of resonances in dynamically modulated couplers,"We report the observation of nonlinearity-induced broadening of resonances in
dynamically modulated directional couplers. When the refractive index of the
guiding channels in the coupler is harmonically modulated along the propagation
direction and out-of-phase in two channels, coupling can be completely
inhibited at resonant modulation frequencies. We observe that nonlinearity
broadens such resonances and that localization can be achieved even in detuned
systems at power levels well below those required in unmodulated couplers.",0908.3115v1
2009-08-31,Anomalous diffusion in the resonant quantum kicked rotor,"We study the resonances of the quantum kicked rotor subjected to an
excitation that follows a deterministic time-dependent prescription. For the
primary resonances we find an analytical relation between the long-time
behavior of the standard deviation and the external kick strength. For the
secondary resonances we obtain essentially the same result numerically.
Selecting the time sequence of the kick allows to obtain a variety of
asymptotic wave-function spreadings: super-ballistic, ballistic, sub-ballistic,
diffusive, sub-diffusive and localized.",0908.4596v2
2009-09-07,Anomalous magnetotransport and cyclotron resonance of high mobility magnetic 2DHGs in the quantum Hall regime,"Low temperature magnetotransport measurements and far infrared transmission
spectroscopy are reported in molecular beam epitaxial grown two-dimensional
hole systems confined in strained InAs quantum wells with magnetic impurities
in the channel. The interactions of the free holes spin with the magnetic
moment of 5/2 provided by manganese features intriguing localization phenomena
and anomalies in the Hall and the quantum Hall resistance. In magnetic field
dependent far infrared spectroscopy measurements well pronounced cyclotron
resonance and an additional resonance are found that indicates an anticrossing
with the cyclotron resonance.",0909.1124v1
2009-10-09,Extraction of Transition Form Factors for Nucleon Resonances within a Coupled-Channels Model,"We explain how an analytic continuation we have developed recently is applied
to determine the residues of the nucleon resonance poles within a dynamical
coupled-channel model of meson-baron reactions. A procedure for evaluating the
electromagnetic N-N^* transition form factors at resonance poles is developed.
Illustrative results of the obtained N^* -> pi N, gamma N transition form
factors for P_{11}, P_{33}, and D_{13} nucleon resonances are presented and
compared with previous results.",0910.1742v1
2009-10-14,Switching management in couplers with biharmonic longitudinal modulation of refractive index,"We address light propagation in couplers with longitudinal biharmonic
modulation of refractive index in neighboring channels. While simplest
single-frequency out-of-phase modulation allows suppression of coupling for
strictly defined set of resonant frequencies, the addition of modulation on
multiple frequency dramatically modifies the structure of resonances. Thus,
additional modulation on double frequency may suppress primary resonance, while
modulation on triple frequency causes fusion of primary and secondary
resonances.",0910.2670v1
2009-10-18,Discovery Potential for Di-lepton and Lepton+Etmiss Resonances at High Mass with ATLAS,"This paper describes the discovery potential for new resonances with the
ATLAS experiment. The resonances discussed in here are the Z', leptoquarks,
graviton and W' resonances in some of their leptonic final states, considering
a center-of-mass energy of 14 TeV for all of them, and an estimation of the
potential of the W' search at the early center-of-mass energy of the LHC . The
studied scenarios show that an initial run of few tens of 1/pb would be enough
to go beyond the current limits in most of these models.",0910.3378v1
2009-11-02,Resonant Tunneling through S- and U-shaped Graphene Nanoribbons,"We theoretically investigate resonant tunneling through S- and U-shaped
nanostructured graphene nanoribbons. A rich structure of resonant tunneling
peaks are found eminating from different quasi-bound states in the middle
region. The tunneling current can be turned on and off by varying the Fermi
energy. Tunability of resonant tunneling is realized by changing the width of
the left and/or right leads and without the use of any external gates.",0911.0247v2
2009-11-08,Resonant guided wave networks,"A resonant guided wave network (RGWN) is an approach to optical materials
design in which power propagation in guided wave circuits enables material
dispersion. The RGWN design, which consists of power-splitting elements
arranged at the nodes of a waveguide network, results in wave dispersion which
depends on network layout due to localized resonances at several length scales
in the network. These structures exhibit both localized resonances with Q ~ 80
at 1550 nm wavelength as well as photonic bands and band-gaps in large periodic
networks at infrared wavelengths.",0911.1567v1
2010-01-07,Intraband resonance Raman scattering in anisotropic quantum dots,"We have developed a theory of the one-phonon intraband resonance Raman
scattering (IRRS) in anisotropic quantum dots subjected to an arbitrarily
directed magnetic field. The differential Raman cross section is obtained. The
resonance structure of the Raman cross section is studied. It is shown that the
quantum dot subjected in a magnetic field can be used as the detector of phonon
modes. The interesting multiplet structure of the resonance peaks is studied.",1001.1037v1
2010-01-12,$VPγ$ radiative decay of resonances dynamically generated from the vector meson-vector meson interaction,"We evaluate the radiative decay into a vector a pseudoscalar and a photon of
several resonances dynamically generated from the vector vector interaction.
The process proceeds via the decay of one of the vector components into a
pseudoscalar and a photon, which have an invariant mass distribution very
different from phase space as a consequence of the two vector structure of the
resonances. Experimental work along these lines should provide useful
information on the nature of these resonances.",1001.1816v1
2010-01-14,Magnetomotive drive and detection of clamped-clamped mechanical resonators in water,"We demonstrate magnetomotive drive and detection of doubly clamped string
resonators in water. A compact 1.9 T permanent magnet is used to detect the
fundamental and higher flexural modes of $\mathrm{200 \mu m}$ long resonators.
Good agreement is found between the magnetomotive measurements and optical
measurements performed on the same resonator. The magnetomotive detection
scheme can be used to simultaneously drive and detect multiple sensors or
scanning probes in viscous fluids without alignment of detector beams.",1001.2497v1
2010-01-19,Isospin breaking effects in the dynamical generation of the X(3872),"We have studied isospin breaking effects in the X(3872) resonance and found a
natural explanation for the branching fraction of the X decaying to $J/\psi$
with two and three pions being close to unit. Within our framework the X(3872)
is a dynamically generated resonance in coupled channels. We also study the
relationship between the couplings of the resonance to the coupled channels
with its wave function, which further helps us to understand the isospin
structure of the resonance.",1001.3254v1
2010-02-01,Thin film dielectric microstrip kinetic inductance detectors,"Microwave Kinetic Inductance Detectors, or MKIDs, are a type of low
temperature detector that exhibit intrinsic frequency domain multiplexing at
microwave frequencies. We present the first theory and measurements on a MKID
based on a microstrip transmission line resonator. A complete characterization
of the dielectric loss and noise properties of these resonators is performed,
and agrees well with the derived theory. A competitive noise equivalent power
of 5$\times10^{-17}$ W Hz$^{-1/2}$ at 1 Hz has been demonstrated. The
resonators exhibit the highest quality factors known in a microstrip resonator
with a deposited thin film dielectric.",1002.0301v1
2010-03-22,Arbitrary Control of Entanglement between Two Superconducting Resonators,"We present a method to synthesize an arbitrary quantum state of two
superconducting resonators. This state-synthesis algorithm utilizes a coherent
interaction of each resonator with a tunable artificial atom to create
entangled quantum superpositions of photon number (Fock) states in the
resonators. We theoretically analyze this approach, showing that it can
efficiently synthesize NOON states, with large photon numbers, using existing
technology.",1003.4284v3
2010-04-09,Superconducting Qubits Coupled to Torsional Resonators,"We propose a scheme of strong and tunable coupling between a superconducting
phase qubit and nanomechanical torsional resonator. In our scheme the torsional
resonator directly modulates the largest energy scale (the Josephson coupling
energy) of the phase qubit, and the coupling strength is very large. We analyze
the quantum correlation effects in the torsional resonator as a result of the
strong coupling to the phase qubit.",1004.1497v2
2010-04-13,Deterministic Generation of Entangled Photons in Superconducting Resonator Arrays,"We present a scheme for the deterministic generation of entangled photon
pairs in a superconducting resonator array. The resonators form a
Jaynes-Cummings lattice via the coupling to superconducting qubits, and the
Kerr-like nonlinearity arises due to the coupling.We show that entangled
photons can be generated on demand by applying spectroscopic techniques and
exploiting the nonlinearity and symmetry in the resonators. The scheme is
robust against small parameter spreads due to fabrication errors. Our findings
can be used as a key element for quantum information processing in
superconducting quantum circuits.",1004.2240v2
2010-04-25,Evidence for further charmonium vector resonances,"We discuss the shape of threshold signals in production cross sections of the
reaction e+ + e- --> D* + antiD*, at the opening of the D(s)* antiD(s)* and
Lambda(c)+ Lambda(c)- channels. Furthermore, evidence for the 3D, 5S, 4D, 6S,
5D, 7S, 6D, and 8S charmonium vector resonances is presented, on the basis of
data recently published by the BaBar Collaboration. Central masses and
resonance widths are estimated. Confirmation of these resonances would be a
huge step in lifting the precision level of hadron spectroscopy towards that of
atomic spectroscopy, with far-reaching consequences for theory.",1004.4368v1
2010-04-28,The scaling of the density of states in systems with resonance states,"Resonance states of a two-electron quantum dot are studied using a
variational expansion with both real basis-set functions and complex scaling
methods. We present numerical evidence about the critical behavior of the
density of states in the region where there are resonances. The critical
behavior is signaled by a strong dependence of some features of the density of
states with the basis-set size used to calculate it. The resonance energy and
lifetime are obtained using the scaling properties of the density of states",1004.5054v1
2010-06-01,Theory of cavity-enhanced spontaneous parametric downconversion,"In this paper we study photon pairs generated in a nonlinear cavity, composed
of a nonlinear crystal surrounded by mirrors, by the process of spontaneous
parametric downconversion. We analyze two different regimes: singly-resonant
cavities where the signal and idler modes are resonant, and doubly-resonant
cavities where the pump mode is also resonant. We present analytic expressions
for the joint spectral amplitude in these two cases, and study the reduction in
emission bandwidth as the cavity coefficient finesse is increased. We also
study the enhancement of the source brightness resulting from the presence of
the cavity.",1006.0050v1
2010-06-02,Asymmetric planar terahertz metamaterials,"We report an experimental observation of three distinct resonances in split
ring resonators (SRRs) for both vertical and horizontal electric field
polarizations at normal incidence by use of terahertz time domain spectroscopy.
Breaking the symmetry in SRRs by gradually displacing the capacitive gap from
the center towards the corner of the ring allows for an 85% modulation of the
fundamental inductive-capacitive resonance. Increasing asymmetry leads to the
evolution of an otherwise inaccessible high quality factor electric quadrupole
resonance that can be exploited for bio-sensing applications in the terahertz
region.",1006.0288v1
2010-06-07,Bethe-Salpeter equations for the collective modes of the $t-U-V-J$ model with d-wave pairing,"The Bethe-Salpeter equations for the collective modes of a $t$-$U$-$V$-$J$
model are used to analyze the resonance peak observed at $\bf{Q}=(\pi,\pi)$ in
neutron scattering experiments on the cuprates. We assume that the resonance
emerges due to the mixing between the spin channel and 19 other channels. We
have calculated the energy of the lowest mode of the extended Hubbard model
($J=0$) vs the on-site repulsive interaction $U$, as well as the $UJ$ lines in
the interaction parameter space which are consistent with the ARPES data and
reproduces the resonance peak at 40 meV in Bi2212 compound. We find that the
resonance is predominantly a spin exciton.",1006.1388v1
2010-06-09,The off-resonant dielectronic recombination in a collision of an electron with a heavy hydrogen-like ion,"The recombination of an electron with an (initially) hydrogen-like ion is
investigated. The effect of the electron-electron interaction is treated
rigorously to the first order in the parameter 1/Z and within the
screening-potential approximation to higher orders in 1/Z, with Z being the
nuclear charge number. The two-electron correction contains the
dielectronic-recombination part, which contributes to the process not only
under the resonance condition for the projectile energy but also in the regions
far from resonances. The mechanism of the off-resonant dielectronic
recombination is studied in detail.",1006.1809v1
2010-06-19,Enhancement and Inhibition of Transmission from metal gratings: Engineering the Spectral Response,"We present a systematic analysis of the optical properties of slit arrays in
metal films. An exhaustive investigation of geometrical and dispersive
properties reveals the resonance features of these structures, including the
role of surface waves and their relationship with features in the transmission
spectrum. Although enhanced transmission windows are significantly dominated by
the longitudinal resonances localized inside the slits, the periodicity
introduces transverse resonances that can either enhance or inhibit light
transmission. We thus illustrate the intriguing interaction regime between
longitudinal and transverse resonances, where the two modes hybridize leading
to the formation of a photonic band gap spectrum.",1006.3841v1
2010-06-29,Dark resonances in the field of frequency shifted feedback laser radiation,"We present a theory of dark resonances in a fluorescence of a three-level
atom gas interacting with a polychromatic field of a frequency shifted feedback
(FSF) laser. We show that conditions for the resonance observation are optimal
when the phase relations between the laser spectral components provide
generation of a light pulses train. We study analytically the field broadening
and the light shift of the resonances.",1006.5595v2
2010-07-02,Spin-polarizing properties of heterostructures with magnetic nano elements,"The problem of electron resonant and non-resonant scatterings on two
magnetized barriers is studied in the one-dimension. The transfer-matrix is
built up to exactly calculate the coefficient of the electron transmittance
through the system of two magnetic barriers with non-collinear magnetizations.
The polarization of the transmitted electron wave for resonance and
non-resonance transmittances is calculated. The transmittance coefficient and
spin polarization can be drastically enhanced and controlled by the angle
between the barrier magnetizations",1007.0421v1
2010-07-16,Controlling phase separation of binary Bose-Einstein condensates via mixed-spin-channel Feshbach resonance,"We investigate controlled phase separation of a binary Bose-Einstein
condensate (BEC) in the proximity of mixed-spin-channel Feshbach resonance in
the |F = 1, mF = +1> and |F = 2,mF = -1> states of 87Rb at a magnetic field of
9.10 G. Phase separation occurs on the lower magnetic-field side of the
Feshbach resonance while the two components overlap on the higher
magnetic-field side. The Feshbach resonance curve of the scattering length is
obtained from the shape of the atomic cloud by comparison with the numerical
analysis of coupled Gross-Pitaevskii equations.",1007.2690v1
2010-07-29,Current response of ac-driven nanoelectromechanical systems in single-electron tunneling regime,"We investigate electric current in a single-electron tunnelling device weakly
coupled to an ac-driven underdamped harmonic nanomechanical oscillator. In the
linear regime, the current can respond to the external frequency in a resonant
as well as in an anti-resonant fashion. The main resonance is accompanied by an
additional resonance at a half of the external frequency.",1007.5186v2
2010-08-06,Spin Resonance and dc Current Generation in a Quantum Wire,"We show that in a quantum wire the spin-orbit interaction leads to a narrow
spin resonance at low temperatures, even in the absence of an external magnetic
field. A relatively weak dc magnetic field of a definite direction strongly
increases the resonance absorption. Linearly polarized resonance radiation
produces dynamic magnetization as well as electric and spin currents. The
effect strongly depends on the external magnetic field.",1008.1225v1
2010-08-23,Statistics of resonance states in a weakly open chaotic cavity,"In this letter, we demonstrate that a non-Hermitian Random Matrix description
can account for both spectral and spatial statistics of resonance states in a
weakly open chaotic wave system with continuously distributed losses. More
specifically, the statistics of resonance states in an open 2D chaotic
microwave cavity are investigated by solving the Maxwell equations with lossy
boundaries subject to Ohmic dissipation. We successfully compare the statistics
of its complex-valued resonance states and associated widths with analytical
predictions based on a non-Hermitian effective Hamiltonian model defined by a
finite number of fictitious open channels.",1008.3878v1
2010-09-16,Engineering two-mode squeezed states of cold atomic clouds with a superconducting stripline resonator,"A scheme is proposed for engineering two-mode squeezed states of two
separated cold atomic clouds positioned near the surface of a superconducting
stripline resonator. Based on the coherent magnetic coupling between the atomic
spins and a stripline resonator mode, the desired two-mode squeezed state can
be produced via precisely control on the dynamics of the system. This scheme
may be used to realize scalable on-chip quantum networks with cold atoms
coupling to stripline resonators.",1009.3140v1
2010-09-17,Interferometric detection of mode splitting for whispering gallery mode biosensors,"Sensors based on whispering gallery mode resonators can detect single
nanoparticles and even single molecules. Particles attaching to the resonator
induce a doublet in the transmission spectrum which provides a self-referenced
detection signal. However, in practice this spectral feature is often obscured
by the width of the resonance line which hides the doublet structure. This
happens particularly in liquid environments that reduce the effective Q factor
of the resonator. In this paper we demonstrate an interferometric set-up that
allows the direct detection of the hidden doublet and thus provides a pathway
for developing practical sensor applications.",1009.3329v1
2010-09-21,Electron Spin Resonance of the ferromagnetic Kondo lattice CeRuPO,"The spin dynamics of the ferromagnetic Kondo lattice CeRuPO is investigated
by Electron Spin Resonance (ESR) at microwave frequencies of 1, 9.4, and
34~GHz. The measured resonance can be ascribed to a rarely observed bulk Ce3+
resonance in a metallic Ce compound and can be followed below the ferromagnetic
transition temperature Tc=14 K. At T>Tc the interplay between the RKKY-exchange
interaction and the crystal electric field anisotropy determines the ESR
parameters. Near Tc the spin relaxation rate is influenced by the critical
fluctuations of the order parameter.",1009.4108v1
2010-09-21,Tunable backaction of a dc SQUID on an integrated micromechanical resonator,"We have measured the backaction of a dc superconducting quantum interference
device (SQUID) position detector on an integrated 1 MHz flexural resonator. The
frequency and quality factor of the micromechanical resonator can be tuned with
bias current and applied magnetic flux. The backaction is caused by the Lorentz
force due to the change in circulating current when the resonator displaces.
The experimental features are reproduced by numerical calculations using the
resistively and capacitively shunted junction (RCSJ) model.",1009.4115v1
2010-10-28,Gas lasers with wave-chaotic resonators,"Semiclassical multimode laser theory is extended to gas lasers with open
two-dimensional resonators of arbitrary shape. The Doppler frequency shift of
the linear-gain coefficient leads to an additional linear coupling between the
modes, which, however, is shown to be negligible. The nonlinear laser equations
simplify in the special case of wave-chaotic resonators. In the single-mode
regime, the intensity of a chaotic laser, as a function of the mode frequency,
displays a local minimum at the frequency of the atomic transition. The width
of the minimum scales with the inhomogeneous linewidth, in contrast to the Lamb
dip in uniaxial resonators whose width is given by the homogeneous linewidth.",1010.5985v1
2010-11-16,Controlling metamaterial resonances via dielectric and aspect ratio effects,"We study ways to enhance the sensitivity and dynamic tuning range of the
fundamental inductor-capacitor (LC) resonance in split ring resonators (SRRs)
by controlling the aspect ratio of the SRRs and their substrate thickness. We
conclude that both factors can significantly affect the LC resonance. We show
that metafilms consisting of low height SRRs on a thin substrate are most
sensitive to changes in their dielectric environment and thus show excellent
potential for sensing applications.",1011.3629v1
2010-12-07,Cavity cooling of a mechanical resonator in the presence of two-level-system defects,"Cavity cooling via quantum backaction force can extract thermal fluctuations
from a mechanical resonator to reach the quantum ground state. Surface or bulk
two-level-system (TLS) defects in a mechanical resonator can couple with the
mechanical mode via deformation potential and affect the cooling process
significantly. Here, we develop a theory to study the cavity cooling of a
mechanical mode in the presence of a TLS defect using the adiabatic elimination
technique. Our result shows that the cooling process depends strongly on the
resonance and the damping rate of the TLS.",1012.1380v2
2010-12-09,Second-order polaron resonances in self assembled quantum dots,"We theoretically study the optical properties of an InAs/GaAs quantum dot
(QD) near the area of the second-order resonance between an electron confined
in the QD and two longitudinal optical phonons. We present the absorption
spectra of an inhomogeneously broadened QD ensemble and show that the minimal
model needed for an accurate description of such a system needs to account for
3-phonon states. We study also the influence of the QD height to width ratio on
the optical properties of the polaron system. The dependence of the width of
the resonance and the position of the second-order resonant feature on the
height to width ratio is presented.",1012.2132v1
2010-12-14,Phonon Mediated Off-Resonant Quantum Dot-Cavity Coupling,"A theoretical model for the phonon-mediated off-resonant coupling between a
quantum dot and a cavity, under resonant excitation of the quantum dot, is
presented. We show that the coupling is caused by electron-phonon interaction
in the quantum dot and is enhanced by the cavity. We analyze recently observed
resonant quantum dot spectroscopic data by our theoretical model.",1012.3125v1
2010-12-20,Zero field spin polarization in a 2D paramagnetic resonant tunneling diode,"We study I-V characteristics of an all-II-VI semiconductor resonant tunneling
diode with dilute magnetic impurities in the quantum well layer. Bound magnetic
polaron states form in the vicinity of potential fluctuations at the well
interface while tunneling electrons traverse these interface quantum dots. The
resulting microscopic magnetic order lifts the degeneracy of the resonant
tunneling states. Although there is no macroscopic magnetization, the resulting
resonant tunneling current is highly spin polarized at zero magnetic field due
to the zero field splitting. Detailed modeling demonstrates that the local spin
polarization efficiency exceeds 90% without an external magnetic field.",1012.4261v1
2011-03-04,Dynamically generated hadron resonances,"As an example of dynamically generated resonances we mention the interaction
of vector mesons with baryons within the local hidden gauge formalism which
gives rise to a large amount of such states, many of which can be associated to
known resonances, while others represent predictions for new resonances. The
width of these states coming from decay into pseudoscalar baryon is also
addressed. We also mention recent states coming from $\Delta \rho \pi$
interaction obtained with Faddeev equations.",1103.0807v1
2011-03-04,Theory of Anisotropic Whispering Gallery Resonators,"An analytic solution for an uniaxial spherical resonator is presented using
the method of Debye potentials. This serves as a starting point for the
calculation of whispering gallery modes (WGM) in such a resonator. Suitable
approximations for the radial functions are discussed in order to best
characterize WGMs. The characteristic equation and its asymptotic expansion for
the anisotropic case is also discussed, and an analytic formula with a
precision of the order $O[\nu^{-1}]$ is also given. Our careful treatment of
both boundary conditions and asymptotic expansions makes the present work a
particularly suitable platform for a quantum theory of whispering gallery
resonators.",1103.0863v1
2011-04-08,Inelastic Confinement-Induced Resonances in Low-Dimensional Quantum Systems,"A theoretical model is presented describing the confinement-induced
resonances observed in the recent loss experiment of Haller et al. [Phys. Rev.
Lett. 104, 153203 (2010)]. These resonances originate from possible molecule
formation due to the coupling of center-of-mass and relative motion. A
corresponding model is verified by ab initio calculations and predicts the
resonance positions in 1D as well as in 2D confinement in agreement with the
experiment. This resolves the contradiction of the experimental observations to
previous theoretical predictions.",1104.1561v3
2011-04-19,Newtonian gravity and resonance on de-Sitter branes,"A dS brane on the boundary between two five-dimensional spacetimes is
determined. We consider asymmetric scenarios with AdS${}_5$ vacua at each side
of the dS brane; and as a result, a resonant mode inside of the spectrum of the
gravitational fluctuations is found. We analyze the deviations to the Newton
potential generated by the gravitational excitations, finding that, for
scenarios with large values of the cosmological constants, the contribution of
the resonant mode is exponentially suppressed. However, when one of the vacua
is null, the resonant mode belongs to the light states set of the gravitational
fluctuations and five-dimensional gravity is recovered on the dS brane.",1104.3627v1
2011-04-22,Stochastic Resonance in a simple model of magnetic reversals,"We discuss the effect of stochastic resonance in a simple model of magnetic
reversals. The model exhibits statistically stationary solutions and bimodal
distribution of the large scale magnetic field. We observe a non trivial
amplification of stochastic resonance induced by turbulent fluctuations, i.e.
the amplitude of the external periodic perturbation needed for stochastic
resonance to occur is much smaller than the one estimated by the equilibrium
probability distribution of the unperturbed system. We argue that similar
amplifications can be observed in many physical systems where turbulent
fluctuations are needed to maintain large scale equilibria.",1104.4417v1
2011-04-27,"Plasmon Resonances in Nanoparticles, Their Applications to Magnetics and Relation to the Riemann Hypothesis","The review of the mathematical treatment of plasmon resonances as an
eigenvalue problem for specific boundary integral equations is presented and
general properties of plasmon spectrum are outlined. Promising applications of
plasmon resonances to magnetics are described. Interesting relation of
eigenvalue treatment of plasmon resonances to the Riemann hypothesis is
discussed.",1104.5202v2
2011-05-18,Interaction between Metamaterial Resonators and Inter-subband transitions in Semiconductor Quantum Wells,"We report on the coupling and interaction between the fundamental resonances
of planar metamaterials (split ring resonators) and inter-subband transitions
in GaAs/AlGaAs quantum wells structures in the mid-infrared. An incident field
polarized parallel to the sample surface is converted by the metamaterial
resonators into a field with a finite component polarized normal to the
surface, and interacts strongly with the large dipole moment associated with
quantum well inter-subband transitions.",1105.3523v1
2011-05-19,Resonator/zero-Qubit architecture for superconducting qubits,"We analyze the performance of the Resonator/zero-Qubit (RezQu) architecture
in which the qubits are complemented with memory resonators and coupled via a
resonator bus. Separating the stored information from the rest of the
processing circuit by at least two coupling steps and the zero qubit state
results in a significant increase of the ON/OFF ratio and the reduction of the
idling error. Assuming no decoherence, we calculate such idling error, as well
as the errors for the MOVE operation and tunneling measurement, and show that
the RezQu architecture can provide high fidelity performance required for
medium-scale quantum information processing.",1105.3997v2
2011-05-24,Driving the resonant quantum kicked rotor via extended initial conditions,"We study the resonances of the quantum kicked rotor subjected to an extended
initial distribution. For the primary resonances we obtain the dispersion
relation for the map of this system. We find an analytical dependence of the
statistical moments on the shape of the initial distribution. For the secondary
resonances we obtain numerically a similar dependence. This allows us to devise
an extended initial condition which produces an average angular momentum
pointing in a preset direction which increases with time with a preset ratio.",1105.4895v1
2011-05-30,Multiply resonant high quality photonic crystal nanocavities,"We propose and experimentally demonstrate a photonic crystal nanocavity with
multiple resonances that can be tuned nearly independently. The design is
composed of two orthogonal intersecting nanobeam cavities. Experimentally, we
measure cavity quality factors of 6,600 and 1000 for resonances separated by
382 nm; we measure a maximum separation between resonances of 506 nm. These
structures are promising for enhancing efficiency in nonlinear optical
processes such as sum/difference frequency and stimulated Raman scattering.",1105.6134v2
2011-06-01,Rabi-vibronic resonance with large number of vibrational quanta,"We study theoretically the Rabi oscillations of a resonantly driven two-level
system linearly coupled to a harmonic oscillator (vibrational mode) with
frequency, \omega_0. We show that for weak coupling, \omega_p \ll \omega_0,
where \omega_p is the polaronic shift, Rabi oscillations are strongly modified
in the vicinity of the Rabi-vibronic resonance \Omega_R = \omega_0, where
\Omega_R is the Rabi frequency. The width of the resonance is
(\Omega_R-\omega_0) \sim \omega_p^{2/3} \omega_0^{1/3} \gg \omega_p. Within
this domain of \Omega_R the actual frequency of the Rabi oscillations exhibits
a bistable behavior as a function of \Omega_R. Importantly, within the resonant
domain, the oscillator is highly excited, which allows to treat it classically.",1106.0278v1
2011-06-08,Surface Acoustic Wave Frequency Comb,"We report on realization of an efficient triply-resonant coupling between two
long lived optical modes and a high frequency surface acoustic wave (SAW) mode
of the same monolithic crystalline whispering gallery mode resonator. The
coupling results in an opto-mechanical oscillation and generation of a
monochromatic SAW. A strong nonlinear interaction of this mechanical mode with
other equidistant SAW modes leads to mechanical hyper-parametric oscillation
and generation of a SAW pulse train and associated frequency comb in the
resonator. We visualized the comb observing the modulation of the modulated
light escaping the resonator.",1106.1477v1
2011-06-21,Resonance measurements in pp and Pb--Pb collisions with the ALICE detector,"The study of resonance production in pp collisions helps understanding
hadronization mechanisms and tuning the QCD-inspired particle production
models. In Pb--Pb collisions, resonances allow one to probe the temperature and
time evolution of the fireball.
  Transverse momentum spectra have been analyzed for $\kstar$, $\phir$ and
$\xstar$ resonances using data from pp collisions at 7 TeV collected by the
ALICE detector. A comparison with Monte Carlo event generators shows different
levels of agreement for meson spectra, while $\xstar$ is always underestimated.",1106.4230v1
2011-06-28,Cooperative resonance linewidth narrowing in a planar metamaterial,"We theoretically analyze the experimental observations of a spectral line
collapse in a metamaterial array of asymmetric split ring resonators [Fedotov
et al., Phys. Rev. Lett. 104, 223901 (2010)]. We show that the ensemble of
closely-spaced resonators exhibits cooperative response, explaining the
observed system-size dependent narrowing of the transmission resonance
linewidth. We further show that this cooperative narrowing depends sensitively
on the lattice spacing and that significantly stronger narrowing could be
achieved in media with suppressed ohmic losses.",1106.5754v2
2011-07-07,The Solar neighbourhood in angle coordinates: the Hyades moving group,"I investigate the suggestion that the Hyades moving group in the Solar
neighbourhood is the result of a recent inner Lindblad resonance. I use
dynamical ""torus"" models of the Galaxy to understand the expected distribution
of solar neighbourhood stars in angle coordinates for phase-mixed models and
models which include a resonant component. I show that attempts to find the
signatures of resonances in angle coordinates are strongly influenced by
selection effects, including rather subtle effects associated with the
relationship between action and angle for stars at a given point. These effects
mean that one can not use simple tests to determine whether substructures seen
in the Solar neighbourhood are associated with any given resonance.",1107.1384v1
2011-07-13,Multichannel Effects near Confinement-Induced Resonances in Harmonic Waveguides,"We analyze the impact of multichannel scattering in harmonic waveguides on
the positions and widths of confinement-induced resonances for both isotropic
and anisotropic transversal confinement. Multichannel scattering amplitudes and
transmission coefficients are calculated and used to characterize the resonant
behaviour of atomic collisions with varying anisotropy. A mechanism is
established which leads to a splitting of the confinement-induced resonance in
the presence of anisotropy.",1107.2501v2
2011-07-19,Resonances for symmetric two-barrier potentials,"We describe a method for the accurate calculation of bound-state and
resonance energies for one-dimensional potentials. We calculate the shape
resonances for symmetric two-barrier potentials and compare them with those
coming from the Siegert approximation, the complex scaling method and the
box-stabilization method. A comparison of the Breit-Wigner profile and the
transmission coefficient about its maximum illustrates that the agreement is
better the sharper the resonance.",1107.4092v2
2011-08-12,Electrodynamics of the Josephson-Coupled Parallel Plate Resonator,"Eigen oscillations in a superconducting parallel plate resonator with the
Josephson-coupled plates are investigated. While the insulator thickness S
changes from tens of microns down to the decay lengthscale of the
superconducting wavefunction into a dielectric, \xi~1 nm, both the resonant
frequency and Q-factor vary non-monotonically by up to three orders in
magnitude. A crossover between the Swihart waves and Josephson plasmons causes
a global minimum in the resonant frequency and a local maximum in the Q-factor
at S~10\xi.",1108.2697v1
2011-08-30,Exploration of resonance properties in chiral perturbation theory with explicit U_A(1) anomaly,"We study the resonance properties within chiral perturbation theory by
explicitly taking into account the U_A(1) anomaly effect. This assures we have
the appropriate degrees of freedom of low energy QCD in the large Nc limit. We
calculate the various resonance properties, such as mass, width and residues,
for the physical case, i.e. Nc=3. Then we extrapolate the values of Nc to study
the trajectories of resonance poles.",1108.5865v2
2011-09-02,Intrinsic noise induced resonance in presence of sub-threshold signal in Brusselator,"In a system of non-linear chemical reactions called the Brusselator, we show
that {\it intrinsic noise} can be regulated to drive it to exhibit resonance in
the presence of a sub-threshold signal. The phenomena of periodic stochastic
resonance and aperiodic stochastic resonance, hitherto studied mostly with
extrinsic noise, is demonstrated here to occur with inherent systemic noise
using exact stochastic simulation algorithm due to Gillespie. The role of
intrinsic noise in a couple of other phenomena is also discussed.",1109.0408v1
2011-09-14,Ultracold bosons in the vicinity of a narrow resonance: shallow dimer and recombination,"The different resonant regimes that can be achieved by using a magnetic
Feshbach resonance are analyzed with a separable two-channel model. Emphasis is
put on the case of narrow resonances in a region of intermediate detuning where
a shallow dimer exists and an approximate law including the background
scattering length for the three-body recombination rate is derived.",1109.3002v1
2011-09-16,Tuning the Nonlinear Response of Coupled Split-Ring Resonators,"We introduce the concept of controlling the nonlinear response of the
metamaterial by altering its internal structure. We experimentally demonstrate
tuning of the nonlinear response of two coupled split-ring resonators by
changing their mutual position. This effect is achieved through modification of
the structure of the coupled resonant modes, and their interaction with the
incident field. By offsetting the resonators we control the maximum currents
through the nonlinear driving elements, which affects the nonlinear response of
the system.",1109.3518v3
2011-09-22,GHz optomechanical resonators with high mechanical Q factor in air,"We demonstrate wheel-shaped silicon optomechanical resonators for resonant
operation in ambient air. The high finesse of optical whispering gallery modes
(loaded optical Q factor above 500,000) allows for efficient transduction of
the wheel resonator's mechanical radial contour modes of frequency up to 1.35
GHz with high mechanical Q factor around 4,000 in air.",1109.4705v1
2011-09-23,Analytic representations of standard and extended non-resonant thermonuclear functions with depleted tail through the pathway model,"The method for the evaluation of the non-resonant thermonuclear function in
the Maxwell-Boltzmann case with depleted tail is discussed. Closed forms of the
analytical results are obtained in computational format, and written in terms
of the H-function in two variables. The standard non-resonant cases are
extended to Tsallis reaction rates through the pathway model. Behavior of the
depleted non-resonant thermonuclear function is studied. A comparison of the
Maxwell-Boltzmann energy distribution with a more general energy distribution
called pathway energy distribution is also done.",1109.5610v1
2011-09-30,Electromagnetic Excitation of Nucleon Resonances,"Recent progress on the extraction of electromagnetic properties of nucleon
resonance excitation through pion photo- and electroproduction is reviewed.
Cross section data measured at MAMI, ELSA, and CEBAF are analyzed and compared
to the analysis of other groups. On this basis, we derive longitudinal and
transverse transition form factors for most of the four-star nucleon
resonances. Furthermore, we discuss how the transition form factors can be used
to obtain empirical transverse charge densities. Contour plots of the thus
derived densities are shown for the Delta, Roper, S11, and D13 nucleon
resonances.",1109.6745v1
2011-10-04,Optical control of Feshbach resonances in Fermi gases using molecular dark states,"We propose a general method for optical control of magnetic Feshbach
resonances in ultracold atomic gases with more than one molecular state in an
energetically closed channel. Using two optical frequencies to couple two
states in the closed channel, inelastic loss arising from spontaneous emission
is greatly suppressed by destructive quantum interference at the two-photon
resonance, i.e., dark-state formation, while the scattering length is widely
tunable by varying the frequencies and/or intensities of the optical fields.
This technique is of particular interest for a two-component atomic Fermi gas,
which is stable near a Feshbach resonance.",1110.0650v1
2011-10-05,Off-resonant coupling between a single quantum dot and a nanobeam photonic crystal cavity,"We demonstrate off-resonant coupling between a single quantum dot and a
nanobeam photonic crystal cavity, under resonant excitation of the quantum dot
or the cavity. These results are consistent with previous descriptions of
off-resonant coupling as an incoherent phonon-mediated process. The extension
of this phenomenon to a nanobeam photonic crystal cavity presents interesting
possibilities for coherent control of this interaction by tailoring the phonon
density of states.",1110.0878v1
2011-12-05,Strong coupling of spin qubits to a transmission line resonator,"We propose a mechanism for coupling spin qubits formed in double quantum dots
to a superconducting transmission line resonator. Coupling the resonator to the
gate controlling the interdot tunneling creates a strong spin qubit--resonator
interaction with strength of tens of MHz. This mechanism allows operating the
system at a point of degeneracy where dephasing is minimized. The transmission
line can serve as a shuttle allowing for two-qubit operations, including fast
generation of qubit-qubit entanglement and the implementation of a
controlled-phase gate.",1112.0869v2
2011-12-05,Boundary Resonances in S = 1/2 Antiferromagnetic Chains under a Staggered Field,"We develop a boundary field theory approach to electron spin resonance in
open $S=1/2$ Heisenberg antiferromagnetic chains with an effective staggered
field. In terms of the sine Gordon effective field theory with boundaries,we
point out the existence of boundary bound states of elementary excitations, and
modification of the selection rules at the boundary. We argue that several
""unknown modes"" found in electron spin resonance experiments on KCuGaF$_6$ [I.
Umegaki et al., Phys. Rev. B 79, 184401 (2009)] and Cu-PM [S. A. Zvyagin et
al., Phys. Rev. Lett. 93, 027201 (2004)] can be understood as boundary
resonances introduced by these effects.",1112.1088v2
2011-12-15,Fermi acceleration in time-dependent rectangular billiards due to multiple passages through resonances,"We consider a slowly rotating rectangular billiard with moving boundaries and
use the canonical perturbation theory to describe the dynamics of a billiard
particle. In the process of slow evolution certain resonance conditions can be
satisfied. Correspondingly, phenomena of scattering on a resonance and capture
into a resonance happen in the system. These phenomena lead to destruction of
adiabatic invariance and to unlimited acceleration of the particle.",1112.3472v2
2011-12-15,Electromagnetic cavity tests of Lorentz invariance on Earth and in space,"We present a Michelson-Morley type experiment for testing the isotropy of the
speed of light in vacuum and matter. The experiment compares the resonance
frequency of an actively rotated monolithic optical cryogenic sapphire
resonator against the resonance frequency of a stationary evacuated optical
cavity made of ultra-low-expansion glass. The results yield an upper limit for
the anisotropy of the speed of light in matter (sapphire) of Delta(c)/c < 1 x
10^-16, limited by the frequency stability of the sapphire resonator.",1112.3857v1
2011-12-20,Resonances contribution to two-photon exchange effects and possible large forward-backward asymmetry in $e^+ e^- \rightarrow p \bar{p}$,"The resonances ($\eta_c,\chi_{c0,c2}$) contribution to two-photon exchange
(TPE) effects in $e^+ e^- \leftrightarrow p \bar{p}$ is calculated in a simple
hadronic model. The calculation shows the TPE contributions by resonance
$\chi_{c2}$, which are dependent on the unknown phases $\phi_{E,M}$ of proton's
time-like form factors $G_{E,M}$, are much larger than the TPE contributions by
non-resonance and are comparable with measurement precision of coming PANDA
detector at $\sqrt{s} \sim M_{\chi_{c2}}$ for most $\phi_{E,M}$.",1112.4615v2
2012-02-09,Exponential decay and resonances in a driven system,"We study the resonance phenomena for time periodic perturbations of a
Hamiltonian $H$ on the Hilbert space $L^2(\mathbb R ^d)$. Here, resonances are
characterized in terms of time behavior of the survival probability. Our
approach uses the Floquet-Howland formalism combined with the results of L.
Cattaneo, J.M. Graf and W. Hunziker on resonances for time independent
perturbations.",1202.2027v4
2012-02-29,"Oscillators with Parametrically Excited Nonlinearity: Resonance, Anti-resonance and Switch","We discover presence of a hitherto unexplored type of resonance in a
parametrically excited Van der Pol oscillator. The oscillator also possesses a
state of anti-resonance. In the weak non-linear limit, we explain how to
practically get a complete picture of different states of limiting oscillations
present in the oscillator when the non-linear term therein is excited by an
arbitrary $2\pi$ periodic function of time. We also illustrate how two such
oscillators can be coupled to behave like a two-state switch allowing an sharp
change of value of amplitude for stable oscillations from one constant to
another.",1202.6592v1
2012-03-20,Superconducting Resonators with Parasitic Electromagnetic Environments,"Parasitic electromagnetic fields are shown to strongly suppress the quality
(Q)-factor of superconducting coplanar waveguide resonators via non-local
dissipation in the macroscopic environment. Numerical simulation and low
temperature measurements demonstrate how this parasitic loss can be reduced,
establishing a Lorentzian lineshape in the resonator frequency response and
yielding a loaded Q-factor of 2.4 x 10^5 for niobium devices on sapphire
substrates. In addition, we report the dependence of the Q and resonance
frequency shift Delta f_0 with input power and temperature in the limit where
loss from two-level systems in the dielectric dominate.",1203.4442v1
2012-06-11,Resonant plasmonic effects in periodic graphene antidot arrays,"We show that a graphene sheet perforated with micro- or nano-size antidots
have prominent absorption resonances in the microwave and terahertz regions.
These resonances correspond to surface plasmons of a continuous sheet
""perturbed"" by a lattice. They are excited in different diffraction orders, in
contrast to cavity surface plasmon modes existing in disconnected graphene
structures. The resonant absorption by the antidot array can essentially exceed
the absorption by a continuous graphene sheet, even for high antidot
diameter-to-period aspect ratios. Surface plasmon-enhanced absorption and
suppressed transmission is more efficient for higher relaxation times of the
charge carriers.",1206.2163v1
2012-06-11,Damping and decoherence of Fock states in a nanomechanical resonator due to two level systems,"We numerically investigate the decay of initial quantum Fock states and their
superpositions for a mechanical resonator mode coupled to an environment
comprising interacting, damped tunneling two level system (TLS) defects. The
cases of one, three, and six near resonant, interacting TLS's are considered in
turn and it is found that the resonator displays Ohmic bath like decay behavior
with as few as three TLS's.",1206.2200v1
2012-07-02,Spin-dependent Fano resonance induced by conducting chiral helimagnet contained in a quasi-one-dimensional electron waveguide,"Fano resonance appears for conduction through an electron waveguide
containing donor impurities. In this work, we consider the thin-film conducting
chiral helimagnet (CCH) as the donor impurity in a one-dimensional waveguide
model. Due to the spin spiral coupling, interference between the direct and
intersubband transmission channels gives rise to spin-dependent Fano resonance
effect. The spin-dependent Fano resonance is sensitively dependent on the
helicity of the spiral. By tuning the CCH potential well depth and the incident
energy, this provides a potential way to detect the spin structure in the CCH.",1207.0490v2
2012-09-05,Effects of noise on hysteresis and resonance width in graphene and nanotubes resonators,"We investigate the role that noise plays in the hysteretic dynamics of a
suspended nanotube or a graphene sheet subject to an oscillating force. We find
that not only the size but also the position of the hysteresis region in these
systems can be controlled by noise. We also find that nano-resonators act as
noise rectifiers: by increasing the noise in the setup, the resonance width of
the characteristic peak in these systems is reduced and, as a result, the
quality factor is increased.",1209.0975v1
2012-09-07,Effect of C$_{60}$ giant resonance on the photoabsorption of encaged atoms,"The absolute differential oscillator strengths (DOS's) for the
photoabsorption of the Ne, Ar, and Xe atoms encapsulated in the C$_{60}$ have
been evaluated using the time-dependent-density-functional-theory, which solves
the quantum Liouvillian equation with the Lanczos chain method. The
calculations are performed in the energy regions both inside and outside the
C$_{60}$ giant resonance. The photoabsorption spectra of the atoms encaged in
the C$_{60}$ demonstrate strong oscillations inside the energy range of the
C$_{60}$ giant resonance. This type of oscillation cannot be explained by the
confinement resonance, but is due to the energy transfer from the C$_{60}$
valence electrons to the photoelectron through the intershell coupling.",1209.1620v1
2012-10-03,"Resonances for large one-dimensional ""ergodic"" systems","The present paper is devoted to the study of resonances for one-dimensional
quantum systems with a potential that is the restriction to some large box of
an ergodic potential. For discrete models both on a half-line and on the whole
line, we study the distributions of the resonances in the limit when the size
of the box where the potential does not vanish goes to infinity. For periodic
and random potentials, we analyze how the spectral theory of the limit operator
influences the distribution of the resonances.",1210.1000v3
2012-10-08,Quasi-stationary states of electrons interacting with strong electromagnetic field in two-barrier resonance tunnel nano-structure,"An exact solution of non-stationary Schrodinger equation is obtained for a
one-dimensional movement of electrons in an electromagnetic field with
arbitrary intensity and frequency. Using it, the permeability coefficient is
calculated for a two-barrier resonance tunnel nano-structure placed into a
high-frequency electromagnetic field. It is shown that a nano-structure
contains quasi-stationary states the spectrum of which consists of the main and
satellite energies. The properties of resonance and non-resonance channels of
permeability are displayed.",1210.2193v1
2012-10-08,Transforming Fabry-Perot resonances into a Tamm mode,"We propose a novel photonic structure composed of metal nanolayer, Bragg
mirror and metal nanolayer. The structure supports resonances that are
transitional between Fabry-Perot and Tamm modes. When the dielectric contrast
of the DBR is removed these modes are a pair of conventional Fabry-Perot
resonances. They spectrally merge into a Tamm mode at high contrast. Such
behavior differs from the results for structures supporting Tamm modes reported
earlier. The optical properties of the structure in the frequency range of the
DBR stop band, including highly beneficial 50% transmittivity through thick
structures, are determined by the introduced in the paper hybrid resonances.
The results can find a wide range of photonic applications.",1210.2434v1
2012-10-23,Splitting of resonance excitations in nearly optimally doped Ba(Fe0.94Co0.06)2As2: an inelastic neutron scattering study with polarization analysis,"Magnetic excitations in Ba(Fe0.94Co0.06)2As2 are studied by polarized
inelastic neutron scattering (INS) above and below the superconducting
transition. In the superconducting state we find clear evidence for two
resonance-like excitations. At a higher energy of about 8 meV there is an
isotropic resonance mode with weak dispersion along the c-direction. In
addition we find a lower excitation at 4 meV that appears only in the
c-polarized channel and whose intensity strongly varies with the L-component of
the scattering vector. These resonance excitations behave remarkably similar to
the gap modes in the antiferromagnetic phase of the parent compound BaFe2As2.",1210.6386v1
2012-10-25,Resonance Decay Contributions to Higher-Order Anisotropic Flow Coefficients,"We show that in hydrodynamic simulations for relativistic heavy-ion
collisions, strong resonance decay calculations can be performed with fewer
species of particle resonances while preserving good accuracy in single
particle spectra and flow anisotropies. Such partial resonance calculations
boost computation efficiency by a factor of 10 which is essential for large
scale event-by-event simulations.",1210.7010v1
2012-11-18,Spectral and resonance problem for perturbations of periodic Jacobi operators,"Necessary and sufficient conditions are presented for a measure to be the
spectral measure of a finite range or exponentially decaying perturbation of a
periodic Jacobi operator.
  As a corollary we can fully solve the inverse resonance problem: given
resonances and eigenvalues we can recover the spectral measure of the Jacobi
operator; we provide necessary and sufficient conditions under which such an
operator exists and is unique; and we show that the inverse resonance problem
is stable under small perturbations.",1211.4274v3
2012-11-23,Direct Observation of Resonant Scattering Phase Shifts and their Energy Dependence,"We scan the collision energy of two clouds of cesium atoms between 12 and 50
$\mu$K in atomic fountain clock. By directly detecting the difference of s-wave
scattering phase shifts, we observe a rapid variation of a scattering phase
shift through a series of Feshbach resonances. At the energies we use,
resonances that overlap at threshold become resolved. Our statistical phase
uncertainty of 8 mrad can be improved in future precision measurements of
Feshbach resonances to accurately determine the Cs-Cs interactions, which may
provide stringent limits on the time variation of fundamental constants.",1211.5565v1
2012-12-05,Mode splitting of surface plasmon resonances in super-period metal nanohole gratings,"We experimentally observed the surface plasmon resonance mode splitting in a
super-period metal nanohole grating under the transverse magnetic polarization
excitation. The mode splitting was observed in the zeroth order transmission
and also in the first order diffracted transmission. However, the mode
splitting phenomenon is more evident in the first order transmission than in
the zeroth order transmission. It is explained that the mode splitting is due
to the coupling between the surface plasmon resonance mode in the subwavelength
period metal nanohole arrays and the resonance mode of the metal super-grating.",1212.1132v1
2012-12-12,Anisotropic rare-earth spin ensemble strongly coupled to a superconducting resonator,"Interfacing photonic and solid-state qubits within a hybrid quantum
architecture offers a promising route towards large scale distributed quantum
computing. Ideal candidates for coherent qubit interconversion are optically
active spins magnetically coupled to a superconducting resonator. We report on
a cavity QED experiment with magnetically anisotropic Er3+:Y2SiO5 crystals and
demonstrate strong coupling of rare-earth spins to a lumped element resonator.
In addition, the electron spin resonance and relaxation dynamics of the erbium
spins are detected via direct microwave absorption, without aid of a cavity.",1212.2856v1
2012-12-19,Resonance behavior of the defect-induced Raman mode of single-chirality enriched carbon nanotubes,"We present a resonance Raman study of the disorder-induced D mode in a sample
highly enriched with semiconducting (9,7) single-walled carbon nanotubes in the
excitation energy range of 1.49 - 2.05 eV. The intensity of the D mode shows a
resonance behavior near the optical transition of the (9,7) tube. The
well-known dispersion of the D-mode frequency, on the other hand, is not
observed at the resonance, but only above a certain excitation energy. We
explain our results by numerical simulations of the D-mode spectra.",1212.4727v1
2013-01-07,Enhancing photoassociation rates by non-resonant light control of shape resonances,"Photoassociation, assembling molecules from atoms using laser light, is
limited by the low density of atom pairs at sufficiently short interatomic
separations. Here, we show that non-resonant light with intensities of the
order of 10^10 W/cm^2 modifies the thermal cloud of atoms, enhancing the
Boltzmann weight of shape resonances and pushing scattering states below the
dissociation limit. This leads to an enhancement of photoassociation rates by
several orders of magnitude and opens the way to significantly larger numbers
of ground state molecules in a thermal ensemble than achieved so far.",1301.1143v1
2013-01-23,Resonance projectors and asymptotics for r-normally hyperbolic trapped sets,"We prove an asymptotic formula for the number of scattering resonances in a
strip near the real axis when the trapped set is r-normally hyperbolic with r
large and a pinching condition on the normal expansion rates holds. Our
dynamical assumptions are stable under smooth perturbations and motivated by
the setting of black holes. The key tool is a Fourier integral operator which
microlocally projects onto the resonant states in the strip. In addition to
Weyl law, this operator provides new information about microlocal concentration
of resonant states.",1301.5633v3
2013-02-22,Quarkonium Resonance Model of the 125 GeV Boson,"A quarkonium model of the recently discovered X boson at 125 GeV is
investigated. Two isosinglet $J^{PC}=0^{-+}$ resonances $\zeta$ and $\zeta'$
mix and their masses are determined by the masses of the bottomonium and
toponium eigenstates. This mixing is enhanced by the non-perturbative gluon
interaction produced by an axial $U_A(1)$ anomaly. The resonance $\zeta$ is
identified with the 125 GeV boson X, while the heavier $\zeta'$ resonance has a
mass 230 GeV. We assess the most recent data for the decay mode $X\rightarrow
ZZ^*\rightarrow$ 4 leptons with a critical discussion of the determination of
the parity of the $X$ boson.",1302.5583v1
2013-03-06,Resonance-like nuclear processes in solids: 3rd and 4th order processes,"It is recognized that in the family of heavy charged particle and electron
assisted double nuclear processes resonance-like behavior can appear. The
transition rates of the heavy particle assisted 3rd-order and electron assisted
4th-order resonance like double nuclear processes are determined. The power of
low energy nuclear reactions in $Ni-H$ systems formed in $Ni$ placed in $H_{2}$
gas environment is treated. Nuclear power produced by quasi-resonant electron
assisted double nuclear processes in these $Ni-H$ systems is calculated. The
power obtained tallies with experiments and its magnitude is considerable for
practical applications.",1303.1262v2
2013-03-09,Off-resonant Raman echo quantum memory on atoms with natural inhomogeneous broadening in optical QED cavity,"A new scheme of photon echo based quantum memory in the optimal optical QED
cavity with off-resonant Raman atomic transition is proposed. The scheme
employs the atomic ensembles characterized by an optically thin resonant
transition and natural inhomogeneous broadening of the resonant line composed
of the arbitrary narrow homogeneous spectral components. The scheme provides
robust and quite simple coherent control of the light-atoms dynamics that can
be implemented by using an existing optical technique and opens a practical way
for realization of the efficient long-lived multi-mode optical quantum memory.",1303.2235v1
2013-04-03,Polarization conversion loss in birefringent crystalline resonators,"Whispering gallery modes in birefringent crystalline resonators are
investigated. We experimentally investigate the XY--cut resonators made with
LiNbO$_3$, LiTaO$_3$ and BBO and observe strong influence of the resonator's
shape and birefringence on the quality factor of the extraordinary polarized
modes. We show that extraordinary modes can have lower Q and even be suppressed
due to polarization conversion loss. The ordinary ray modes retain the high Q
due to inhibited reflection phenomenon.",1304.1046v1
2013-04-08,Hadronic Resonances in Lattice QCD,"I discuss how masses and widths of hadron resonances are extracted from
lattice QCD. Recent lattice results on the light, strange and charm meson
resonances are reviewed. Their properties are revealed by simulating the
corresponding scattering channels pi-pi, K-pi and D-pi on the lattice and
extracting the scattering phase shifts. In particular we address the resonances
rho, D0*(2400), D1(2430), K*, kappa and K0*(1430).",1304.2143v1
2013-04-18,Negative frequency tuning of a carbon nanotube nano-electromechanical resonator,"A suspended, doubly clamped single wall carbon nanotube is characterized as
driven nano-electromechanical resonator at cryogenic temperatures.
Electronically, the carbon nanotube displays small bandgap behaviour with
Coulomb blockade oscillations in electron conduction and transparent contacts
in hole conduction. We observe the driven mechanical resonance in dc-transport,
including multiple higher harmonic responses. The data shows a distinct
negative frequency tuning at finite applied gate voltage, enabling us to
electrostatically decrease the resonance frequency to 75% of its maximum value.
This is consistently explained via electrostatic softening of the mechanical
mode.",1304.5092v1
2013-04-23,Encapsulation of a fiber taper coupled microtoroid resonator in a polymer matrix,"We encapsulated a high-quality (Q) factor optical whispering gallery mode
(WGM) microtoroid resonator together with its side coupled fiber taper inside a
low refractive index polymer, achieving a final Q higher than 10^7. Packaging
provides stable resonator-fiber taper coupling, long-term maintenance of
high-Q, a protective layer against contaminants, and portability to microtoroid
resonator based devices. We tested the robustness of the packaged device under
various conditions and demonstrated its capability for thermal sensing.",1304.6423v1
2013-04-27,Quantum Decoherence of Charge Qubit coupled to Nonlinear Nanomechanical Resonator,"When the nonlinearity of nanomechanical resonator is not negligible, the
quantum decoherence of charge qubit is studied analytically. Using nonlinear
Jaynes-Cummings model, one explores the possibility of being quantum data bus
for nonlinear nanomechanical resonator, the nonlinearity destroys the dynamical
quantum information-storage and maintains the revival of quantum coherence of
charge qubit. With the calculation of decoherence factor, we demonstrate the
influence of the nonlinearity of nanomechanical resonator on engineered
decoherence of charge qubit.",1304.7325v1
2013-05-02,Photonic molecules formed by coupled hybrid resonators,"We describe a method that enables free-standing whispering-gallery-mode
microresonators, and report spectral tuning of photonic molecules formed by
coupled free and on-chip resonators with different geometries and materials. We
study direct coupling via evanescent fields of free silica microtoroids and
microspheres with on-chip polymer coated silica microtoroids. We demonstrate
thermal tuning of resonance modes to achieve maximal spectral overlap, mode
splitting induced by direct coupling, and the effects of distance between the
resonators on the splitting spectra.",1305.0521v1
2013-05-02,A general procedure for thermomechanical calibration of nano/micro-mechanical resonators,"We provide a detailed description of a general procedure by which a
nano/micro-mechanical resonator can be calibrated using its thermal motion. A
brief introduction to the equations of motion for such a resonator is
presented, followed by a detailed derivation of the corresponding power
spectral density (PSD) function. The effective masses for a number of different
resonator geometries are determined using both finite element method (FEM)
modeling and analytical calculations.",1305.0557v1
2013-05-10,Nontrapping surfaces of revolution with long living resonances,"We study resonances of surfaces of revolution obtained by removing a disk
from a cone and attaching a hyperbolic cusp in its place. These surfaces
include ones with nontrapping geodesic flow (every maximally extended
non-reflected geodesic is unbounded) and yet infinitely many long living
resonances (resonances with uniformly bounded imaginary part, i.e. decay rate).",1305.2434v2
2013-05-13,From quasimodes to resonances: exponentially decaying perturbations,"We consider self-adjoint operators of black-box type which are exponentially
close to the free Laplacian near infinity, and prove an exponential bound for
the resolvent in a strip away from resonances. Here the resonances are defined
as poles of the meromorphic continuation of the resolvent between appropriate
exponentially weighted spaces. We then use a local version of the maximum
principle to prove that any cluster of real quasimodes generates at least as
many resonances, with multiplicity, rapidly converging to the quasimodes.",1305.2896v3
2013-05-21,Centrifugal-Barrier Effects and Determination of the Interaction Radius,"The interaction radius of a resonance is an important physical quantity to
describe the structure of a resonance. But, for a long time, physicists do not
find a reliable way to measure the magnitude of the interaction radius of a
resonance. In this paper, a method is proposed to measure the interaction
radius in physics analysis.
  It is found that the centrifugal barrier effects have great influence to
physical results obtained in the PWA fit, and the interaction radius of some
resonances can be well measured in the fit.",1305.5118v1
2013-05-23,Second harmonic double resonance cones in dispersive hyperbolic metamaterials,"We study the formation of second harmonic double-resonance cones in
hyperbolic metamaterials. An electric dipole on the surface of the structure
induces second harmonic light to propagate into two distinct volume
plasmon-polariton channels: A signal that propagates within its own peculiar
resonance cone; and a phase-locked signal that is trapped under the pump's
resonance cone. Metamaterial dispersion and birefringence induce a large
angular divergence between the two volume plasmon-polaritons, making these
structures ideal for subwavelength second and higher harmonic imaging
microscopy.",1305.5430v1
2013-05-23,Why is the Moon synchronously rotating?,"If the Moon's spin evolved from faster prograde rates, it could have been
captured into a higher spin-orbit resonance than the current 1:1 resonance. At
the current value of orbital eccentricity, the probability of capture into the
3:2 resonance is as high as 0.6, but it strongly depends on the temperature and
average viscosity of the Moon's interior. A warmer, less viscous Moon on a
higher-eccentricity orbit is even more easily captured into supersynchronous
resonances. We discuss two likely scenarios for the present spin-orbit state: a
cold Moon on a low-eccentricity orbit and a retrograde initial rotation.",1305.5441v1
2013-05-26,Observation of resonance-assisted dynamical tunneling in an asymmetric microcavity,"We report the first experimental observation of the resonance-assisted
dynamical tunneling (RADT) in the inter-mode interaction in an
asymmetric-deformed microcavity. A selection rule for strong inter-mode
coupling induced by RADT was observed on angular mode numbers as predicted by
the RADT theory. In addition, the coupling strength was measured to be
proportional to the square of the phase-space area associated with the
nonlinear resonance involved in RADT. The proportionality constant was found to
depend only on the nonlinear resonance, supporting the semiclassical nature of
RADT.",1305.6019v1
2013-05-28,Trampoline metamaterial: Local resonance enhancement by springboards,"We investigate the dispersion characteristics of locally resonant elastic
metamaterials formed by the erection of pillars on the solid regions in a plate
patterned by a periodic array of holes. We show that these solid regions
effectively act as springboards leading to an enhanced resonance behavior by
the pillars when compared to the nominal case of pillars with no holes. This
local resonance amplification phenomenon, which we define as the ""trampoline
effect"", is shown to cause subwavelength band gaps to increase in size by up to
a factor of 4. This outcome facilitates the utilization of subwavelength
metamaterial properties over exceedingly broad frequency ranges.",1305.6584v2
2013-05-28,"Delay of light in an optical bottle resonator with nanoscale radius variation: dispersionless, broadband, and low-loss","It is shown theoretically that an optical bottle resonator with a nanoscale
radius variation can perform a multi-nanosecond long dispersionless delay of
light in a nanometer-order bandwidth with minimal losses. Experimentally, a 3
mm long resonator with a 2.8 nm deep semi-parabolic radius variation is
fabricated from a 19 micron radius silica fiber with a sub-angstrom precision.
In excellent agreement with theory, the resonator exhibits the
impedance-matched 2.58 ns (3 bytes) delay of 100 ps pulses with 0.44 dB/ns
intrinsic loss. This is a miniature slow light delay line with the record large
delay time, record small transmission loss, dispersion, and effective speed of
light.",1305.6591v2
2013-06-04,Laser-Machined Ultra-High-Q Microrod Resonators for Nonlinear Optics,"Optical whispering-gallery microresonators are useful tools in
microphotonics, and nonlinear optics at very low threshold powers. Here, we
present details about the fabrication of ultra-high-Q whispering-gallery-mode
resonators made by CO2-laser lathe machining of fused-quartz rods. The
resonators can be fabricated in less than one minute and the obtained optical
quality factors exceed Q = 10^9. Demonstrated resonator diameters are in the
range between 170 {\mu}m and 8 mm (free spectral ranges between 390 GHz and 8
GHz). Using these microresonators, a variety of optical nonlinearities are
observed, including Raman scattering, Brillouin scattering and four-wave
mixing.",1306.0939v1
2013-06-06,A Compact Dual Band Dielectric Resonator Antenna For Wireless Applications,"This paper presents the design of a dual band rectangular Dielectric
Resonator Antenna (DRA) coupled to narrow slot aperture that is fed by
microstrip line. The fundamental TE111 mode and higher-order TE113 mode are
excited with their resonant frequencies respectively. These frequencies can be
controlled by changing the DRA dimensions. A dielectric resonator with high
permittivity is used to miniaturize the global structure. The proposed antenna
is designed to have dual band operation suitable for both DCS (1710 - 1880 MHz)
and WLAN (2400 - 2484 MHz) applications. The return loss, radiation pattern and
gain of the proposed antenna are evaluated. Reasonable agreement between
simulation and experimental results is obtained.",1306.1335v1
2013-06-17,Fluctuations From Edge Defects in Superconducting Resonators,"Superconducting resonators, used in astronomy and quantum computation, couple
strongly to microscopic two-level defects. We monitor the microwave response of
superconducting resonators and observe fluctuations in dissipation and
resonance frequency. We present a unified model where the observed dissipative
and dispersive effects can be explained as originating from a bath of
fluctuating two-level systems. From these measurements, we quantify the number
and distribution of the defects.",1306.3718v1
2013-06-17,"Non-Gaussian, non-dynamical stochastic resonance","The archetypal system demonstrating stochastic resonance is nothing more than
a threshold triggered device. It consists of a periodic modulated input and
noise. Every time an output crosses the threshold the signal is recorded. Such
a digitally filtered signal is sensitive to the noise intensity. There exist
the optimal value of the noise intensity resulting in the ""most"" periodic
output. Here, we explore properties of the non-dynamical stochastic resonance
in non-equilibrium situations, i.e. when the Gaussian noise is replaced by an
$\alpha$-stable noise. We demonstrate that non-equilibrium $\alpha$-stable
noises, depending on noise parameters, can either weaken or enhance the
non-dynamical stochastic resonance.",1306.3924v1
2013-07-04,Probing Majorana fermions in the tunneling spectra of a resonant level,"Unambiguous identification of Majorana physics presents an outstanding
problem whose solution could render topological quantum computing feasible. We
develop a numerical approach to treat finite-size superconducting chains
supporting Majorana fermions, which is based on iterative application of a
two-site Bogoliubov transformation. We demonstrate the applicability of the
method by studying a resonant level attached to the superconductor subject to
external perturbations. In the topological phase, we show that the spectrum of
a single resonant level allows to distinguish peak coming from Majorana physics
from the Kondo resonance.",1307.1308v1
2013-07-27,Magnetically tunable Feshbach resonances in Li + Yb($^3P_J$),"We have investigated magnetically tunable Feshbach resonances arising from
the interaction of Li($^2S$) with metastable Yb($^3P_2$) and ($^3P_0$). For
Yb($^3P_2$), all the resonance features are strongly suppressed by inelastic
collisions that produce Yb in its lower-lying $^3P_1$ and $^3P_0$ states. For
Yb($^3P_0$), sharp resonances exist but they are extremely narrow (widths less
than 1 mG).",1307.7262v1
2013-10-09,Optical Asymmetry Induced by PT-symmetric Nonlinear Fano Resonances,"We introduce a new type of Fano resonances, realized in a photonic circuit
which consists of two nonlinear PT-symmetric micro-resonators side-coupled to a
waveguide, which have line-shape and resonance position that depends on the
direction of the incident light. We utilize these features in order to induce
asymmetric transport up to 47 dBs in the optical C-window. Our set-up requires
low input power and does not compromise the power and frequency characteristics
of the output signal.",1310.2313v1
2013-10-17,Instability of pre-existing resonances under a small constant electric field,"Two simple model operators are considered which have pre-existing resonances.
A potential corresponding to a small electric field, $f$, is then introduced
and the resonances of the resulting operator are considered as $f\to0$. It is
shown that these resonances are not continuous in this limit. It is conjectured
that a similar behavior will appear in more complicated models of atoms and
molecules. Numerical results are presented.",1310.4745v3
2013-11-25,Inverted-wedge silica resonators for controlled and stable coupling,"Silica microresonators with an inverted-wedge shape were fabricated using
conventional semiconductor fabrication methods. The measured quality factors of
the resonators were greater than $10^6$ in 1550 nm band. Controllable coupling
from under coupling, through critical coupling, to over coupling was
demonstrated by horizontally moving a fiber taper while in touch with the top
surface of the resonator. Thin outer ring of the resonator provided a support
for the fiber taper leading to a robust stable coupling.",1311.6382v1
2013-12-11,Higher-order resonances and instability of high-frequency WKB solutions,"This paper focuses on the destabilizing role of resonances in high-frequency
WKB solutions. Specifically, we study higher-order resonances associated with
higher-order harmonics generated by nonlinearities. We give examples of systems
and solutions for which such resonances generate instantaneous instabilities,
even though the equations linearized around the leading WKB terms are initially
stable, meaning in particular that the key destabilizing terms are not present
in the data.",1312.3243v3
2013-12-12,Stochastic resonance in collective exciton-polariton excitations inside a GaAs microcavity,"We report the first observation of stochastic resonance in confined
exciton-polaritons. We evidence this phenomena by tracking the polaritons
behavior through two stochastic resonance quantifiers namely the spectral
magnification factor and the signal-to-noise ratio. The evolution of the
stochastic resonance in function of the modulation amplitude of the periodic
excitation signal is studied. Our experimental observations are well reproduced
by numerical simulations performed in the framework of the Gross-Pitaevskii
equation under stochastic perturbation.",1312.3633v3
2014-02-02,New narrow N*(1685) resonance: review of observations,"The recent Review of Particle Physics [1] includes a new narrow N*(1685)
resonance. Its properties, the narrow width and the strong photoexcitation on
the neutron, are unusual. The paper reviews experimental data which have led to
the evidence for this resonance. Alternative explanations of the phenomenon at
W ~ 1.685 GeV, namely the interference of well-known resonances and the
sub-threshold meson-baryon production, are discussed as well.",1402.0151v1
2014-02-06,Planar Shielded-Loop Resonators,"The design and analysis of planar shielded-loop resonators for use in
wireless non-radiative power transfer systems is presented. The difficulties
associated with coaxial shielded-loop resonators for wireless power transfer
are discussed and planar alternatives are proposed. The currents along these
planar structures are analyzed and first-order design equations are presented
in the form of a circuit model. In addition, the planar structures are
simulated and fabricated. Planar shielded-loop resonators are compact and
simple to fabricate. Moreover, they are well-suited for printed circuit board
designs or integrated circuits",1402.1219v1
2014-02-23,Adiabatic embedment of nanomechanical resonators in photonic microring cavities,"We report a circuit cavity optomechanical system in which a nanomechanical
resonator is adiabatically embedded inside an optical ring resonator with
ultralow transition loss. The nanomechanical device forms part of the top layer
of a horizontal silicon slot ring resonator, which enables dispersive coupling
to the dielectric substrate via a tapered nanogap. Our measurements show nearly
uncompromised optical quality factors (Q) after the release of the mechanical
beam.",1402.5683v1
2014-04-30,Resonant tunneling through double-barrier structures on graphene,"Quantum resonant tunneling behaviors of double-barrier structures on graphene
are investigated under the tight-binding approximation. The Klein tunneling and
resonant tunneling are demonstrated for the quasiparticles with energy close to
the Dirac points. The Klein tunneling vanishes by increasing the height of the
potential barriers to more than 300 meV. The Dirac transport properties
continuously change to the Schrodinger ones. It is found that the peaks of
resonant tunneling approximate to the eigen-levels of graphene nanoribbons
under appropriate boundary conditions. A comparison between the zigzag- and
armchair-edge barriers is given.",1404.7697v1
2014-07-13,Aharonov-Bohm photonic cages in waveguide and coupled resonator lattices by synthetic magnetic fields,"We suggest a method for trapping photons in quasi one-dimensional waveguide
or coupled-resonator lattices, which is based on an optical analogue of the
Aharonov-Bohm cages for charged particles. Light trapping results from a
destructive interference of Aharonov-Bohm type induced by a synthetic magnetic
field, which is realized by periodic modulation of the waveguide/resonator
propagation constants/resonances.",1407.3486v2
2014-08-05,Electrically driven spin resonance in a bent disordered carbon nanotube,"Resonant manipulation of carbon nanotube valley-spin qubits by an electric
field is investigated theoretically. We develop a new analysis of electrically
driven spin resonance exploiting fixed physical characteristics of the
nanotube: a bend and inhomogeneous disorder. The spectrum is simulated for an
electron valley-spin qubit coupled to a hole valley-spin qubit and an impurity
electron spin, and features that coincide with a recent measurement are
identified. We show that the same mechanism allows resonant control of the full
four-dimensional spin-valley space.",1408.0951v1
2014-08-05,Gravitational resonance spectroscopy with an oscillating magnetic field gradient in the GRANIT flow through arrangement,"Gravitational resonance spectroscopy consists in measuring the energy
spectrum of bouncing ultracold neutrons above a mirror by inducing resonant
transitions between different discrete quantum levels. We discuss how to induce
the resonances with a flow through arrangement in the GRANIT spectrometer,
excited by an oscillating magnetic field gradient. The spectroscopy could be
realized in two distinct modes (so called DC and AC) using the same device to
produce the magnetic excitation. We present calculations demonstrating the
feasibility of the newly proposed AC mode.",1408.1009v1
2014-08-09,Nonlinear transmission spectroscopy with dual frequency combs,"We show how two frequency combs $\mathcal{E}_1$, $\mathcal{E}_2$ can be used
to measure single-photon, two-photon absorption (TPA), and Raman resonances in
a molecule with three electronic bands, by detecting the radio frequency
modulation of the nonlinear transmission signal. Some peaks are independent of
the carrier frequency of the comb and others shift with that frequency and have
a width close to the comb width. TPA and Raman resonances independent of the
carrier frequency are selected by measuring the transmission signal
$\sim\mathcal{E}_1^2 \mathcal{E}_2^2$ and the single-photon resonances are
selected by measuring the transmission signal
$\sim\mathcal{E}_1^3\mathcal{E}_2$. Sinusoidal spectral phase shaping strongly
affects the TPA, but not the Raman resonances.",1408.2158v1
2014-09-17,Resonant threshold two-photon $e^-e^+$ pair production onto the lowest Landau levels in a strong magnetic field,"The process of electron-positron pair production by two photons in a strong
magnetic field has been studied. The process kinematics is considered, and the
probability amplitude for arbitrary polarizations of particles is found. The
resonance conditions are established, and the resonant cross-section is
estimated in the case where the electron and the positron occupy the lowest
levels ($l_{e} = 1$, $l_{p} = 0$) that satisfy these resonance conditions.",1409.4887v1
2014-09-26,Lower bounds for resonance counting functions for obstacle scattering in even dimensions,"In even dimensional Euclidean scattering, the resonances lie on the
logarithmic cover of the complex plane. This paper studies resonances for
obstacle scattering in ${\mathbb R}^d$ with Dirchlet or admissable Robin
boundary conditions, when $d$ is even. Set $n_m(r)$ to be the number of
resonances with norm at most $r$ and argument between $m\pi$ and $(m+1)\pi$.
Then $\lim\sup _{r\rightarrow \infty}\frac{\log n_m(r)}{\log r}=d$ if $m\in
{\mathbb Z}\setminus \{ 0\}$.",1409.7608v1
2014-12-07,Experimental Demonstration of Non-Resonant Hyperlens in the Visible Range,"A metamaterial hyperlens offers a unique solution to overcome the diffraction
limit by transforming evanescent waves responsible for imaging subwavelength
features of an object into propagating waves. However, the first realizations
of optical hyperlenses were limited by a narrow working bandwidth and
significant resonance-induced loss. Here, we report the first experimental
demonstration of a non-resonant waveguide-coupled hyperlens operating in the
visible wavelength range. A detailed investigation of various materials systems
proves that a radial fan-shaped configuration is superior to the concentric
layer-based configuration in that it relies on non-resonant negative dielectric
response, and, as a result, enables broadband and low-loss performance in the
visible range.",1412.2361v1
2014-12-08,Resonant surface plasmons of a metal nanosphere can be considered in the way of propagating surface plasmons,"Assuming that the resonant surface plasmons on a spherical nanoparticle is
formed by standing waves of two counter-propagating surface plasmon waves along
the surface, by using Mie theory simulation, we find that the dispersions of
surface plasmon resonant modes supported by silver nanospheres match that of
the surface plasmons on a semi-infinite medium-silver interface very well. This
suggests that the resonant surface plasmons of a metal nanosphere can be
treated as a propagating surface plasmon wave.",1412.2664v1
2014-12-11,Surface Plasmon Resonance of Nanoparticles and Applications in Imaging,"In this paper we provide a mathematical framework for localized plasmon
resonance of nanoparticles. Using layer potential techniques associated with
the full Maxwell equations, we derive small-volume expansions for the
electromagnetic fields, which are uniformly valid with respect to the
nanoparticle's bulk electron relaxation rate. Then, we discuss the scattering
and absorption enhancements by plasmon resonant nanoparticles. We study both
the cases of a single and multiple nanoparticles. We present numerical
simulations of the localized surface plasmonic resonances associated to
multiple particles in terms of their separation distance.",1412.3656v2
2014-12-17,Femtosecond filamentation by intensity clamping at a Freeman resonance,"We demonstrate that Freeman resonances have a strong impact on the nonlinear
optical response in femtosecond filaments. These resonances decrease the
transient refractive index within a narrow intensity window and strongly affect
the filamentation dynamics. In particular, we demonstrate that the peak
intensity of the filament can be clamped at these resonances, hinting at the
existence of new regimes of filamentation with electron densities considerably
lower than predicted by the standard model. This sheds a new light on the
phenomenon of filamentary intensity clamping and the plasmaless filaments
predicted by the controversial higher-order Kerr model.",1412.5345v1
2014-12-18,Localized guided-mode and cavity-mode double resonance in photonic crystal nanocavities,"We investigate the use of guided modes bound to defects in photonic crystals
for achieving double resonances. Photoluminescence enhancement by more than
three orders of magnitude has been observed when the excitation and emission
wavelengths are simultaneously in resonance with the localized guided mode and
cavity mode, respectively. We find that the localized guided modes are
relatively insensitive to the size of the defect for one of the polarizations,
allowing for flexible control over the wavelength combinations. This double
resonance technique is expected to enable enhancement of photoluminescence and
nonlinear wavelength conversion efficiencies in a wide variety of systems.",1412.5708v1
2014-12-12,The Resonance Scattering Phenomenon of Fast Negatively Charged Particles in a Single Crystal,"The energy spectrum of the extended attractive potential of a
crystallographic row for negatively charged particles has quasi-bound states.
It follows that a negatively charged particle with small transversal momentum
component ($p_{\bot} R <<1$) may undergo resonance scattering. Thus the
resonance scattering phenomenon can be observed in a single crystal, when fast
electrons move with a small glancing angle ($\theta_0 << 1/pR$) to a
crystallographic axis. The calculated results for the electrons and angular
widths of resonance peaks are consistent with experimental data.",1501.02244v1
2015-01-31,"An atomic resolution, single-spin magnetic resonance detection concept based on tunneling force microscopy","A comprehensive study of a force detected single-spin magnetic resonance
measurement concept with atomic spatial resolution is presented. The method is
based upon electrostatic force detection of spin-selection rule controlled
single-electron tunneling between two electrically isolated paramagnetic
states. Single spin magnetic resonance detection is possible by measuring the
force detected tunneling charge noise on and off spin resonance. Simulation
results of this charge noise, based upon physical models of the tunneling and
spin physics, are directly compared to measured AFM system noise. The results
show that the approach could provide single spin measurement of electrically
isolated qubit states with atomic spatial resolution at room temperature.",1502.00053v1
2015-02-18,Symmetry-assisted resonance transmission of identical particles,"We report novel interference effects in wave packet scattering of identical
particles incident on the same side of a resonant barrier, different from those
observed in Hong-Ou-Mandel experiments. These include significant changes in
the mean number of transmissions and full counting statistics, as well as
""bunching"" and ""anti-bunching"" effects in the all-particles transmission
channel. With several resonances involved, pseudo-resonant driving of the
two-level system in the barrier, may result in sharp enhancement of scattering
probabilities for certain values of temporal delay between the particles.",1502.05325v3
2015-04-13,Dispersive calculation of complex Regge trajectories for the lightest $f_2$ resonances,"We apply a recently developed dispersive formalism to calculate the Regge
trajectories of the $f_2(1270)$ and $f_2'(1525)$ mesons. Trajectories are
calculated, not fitted to a family of resonances. Assuming that these spin-2
resonances can be treated in the elastic approximation the only input are the
pole position and residue of the resonances. In both cases, the predicted Regge
trajectories are almost real and linear, with slopes in agreement with the
universal value of order 1 GeV$^{-2}$.",1504.03248v1
2015-04-16,Fix-lines and stability domain in the vicinity of the coupled third order resonance,"The single particle stability in a circular accelerator is of concern
especially for operational regimes involving beam storage of hours. In the
proximity to a resonance this stability domain shrinks, and the phase space
fragments into a jungle of exotic objects like for instance ""fix-lines"". The
concept of fix-points is easily understandable in a 2D phase space. It becomes
quite challenging when the effect of resonances is considered in the 4D phase
space, which leads then to the concept of fix-lines. In this paper we
investigate the fix-lines in the proximity of a coupled third order resonance
and find the relation of these objects with the stability of motion.",1504.04389v1
2015-05-05,Spinor Stochastic Resonance,"We report on noise-induced-spin-ordering in a collective quasipaticle system:
spinor stochastic resonance. Synergetic interplay of a polarization-modulated
signal and a polarization-noise allows us to switch coherently between the two
metastable states of a microcavity-polariton spin bistable system. Spinor
stochastic resonance is demonstrated in a zero-dimensional GaAs based
microcavity. The resonance behavior of both the spin amplification and the
signal-to-noise ratio are experimentally evidenced as a function of the noise
strength for different amplitude modulations. They are theoretically reproduced
using a spinor- Gross-Pitaevskii equation driven by a randomly polarized laser
field.",1505.00929v1
2015-05-11,Resonance-free regions for negatively curved manifolds with cusps,"The Laplace-Beltrami operator on cusp manifolds has continuous spectrum. The
resonances are complex numbers that replace the discrete spectrum of the
compact case. They are the poles of a meromorphic function $\varphi(s)$, $s\in
\mathbb{C}$, the \emph{scattering determinant}. We construct a semi-classical
parametrix for this function in a half plane of $\mathbb{C}$ when the curvature
of the manifold is negative. We deduce that for manifolds with one cusp, there
is a zone without resonances at high frequency. This is true more generally for
manifolds with several cusps and generic metrics.
  We also study some exceptional examples with almost explicit sequences of
resonances away from the spectrum.",1505.02600v2
2015-06-01,Stark-cyclotron Resonance in an Array of Carbon Nanotubes,"Using the kinetic approach based on the semiclassical Boltzmann transport
equation with constant relaxation time, we theoretically studied the
Stark-cyclotron resonance in an array of Carbon Nanotubes (CNs). Exact
expression for the current density was obtained. We noted that Stark-cyclotron
resonance occurs when the Larmor frequency coincides with the Stark frequency.
A coincidence of these frequencies produce resonance.",1506.00521v1
2015-06-18,Multiple magneto-phonon resonances in graphene,"Our low-temperature magneto-Raman scattering measurements performed on
graphene-like locations on the surface of bulk graphite reveal a new series of
magneto-phonon resonances involving both K-point and Gamma-point phonons. In
particular, we observe for the first time the resonant splitting of three
crossing excitation branches. We give a detailed theoretical analysis of these
new resonances. Our results highlight the role of combined excitations and the
importance of multi-phonon processes (from both K and Gamma points) for the
relaxation of hot carriers in graphene.",1506.05700v1
2015-07-14,Resolubility of Image-Potential Resonances,"A theory of image-potential states is presented for the general case where
these surface electronic states are resonant with a bulk continuum. The theory
extends the multiple scattering approach of Echenique and Pendry into the
strong coupling regime while retaining independence from specific forms of
surface and bulk potentials. The theory predicts the existence of a
well-resolved series of resonances for arbitrary coupling strengths.
Surprisingly, distinct image-potential resonances are thus expected to exist on
almost any metal surface, even in the limiting case of jellium.",1507.03812v1
2015-07-29,Resonances in two-electron atoms below the critical charge,"The critical nuclear charge Zc required for a heliumlike atom to have at
least one bound state was recently determined with high accuracy from
variational calculations. Analysis of the wave functions further suggested that
the bound state changes smoothly into a shape resonance as Z crosses the
critical value. Using variational calculations combined with the complex
coordinate rotation method, we study the energy and width of the resonance for
Z \textless{} Zc, thus providing direct evidence of the validity of this
hypothesis. The variation of the resonance width with Z is found to be in good
agreement with a model derived from analysis of the 1/Z perturbation series.",1507.08033v1
2015-08-25,Droplets Acoustics,"Contrary to their capillary resonances (Rayleigh, 1879) and their optical
resonances (Ashkin, 1977), droplets acoustical resonances were rarely
considered. Here we experimentally excite, for the first time, the acoustical
resonances of a droplet that relies on sound instead of capillary waves.
Droplets vibrations at 37 MHz rates and 100 quality factor are optically
excited and interrogated at an optical threshold of 68 microWatt. Our
vibrations span a spectral band that is 1000 times higher when compared with
drops previously-studied capillary vibration.",1508.06628v2
2015-09-17,Long-lived universal resonant Bose gases,"Quantum simulations based on near-resonance Bose gases are limited by their
short lifetimes due to severe atom losses. In addition to this, the recently
predicted thermodynamical instability adds another constraint on accessing the
resonant Bose gases. In this article, we offer a potential solution by
proposing long-lived resonant Bose gases in both two and three dimensions,
where the conventional few-body losses are strongly suppressed. We show that
the thermodynamical properties as well as the lifetimes of these strongly
interacting systems are universal, and independent of short-range physics.",1509.05130v2
2015-09-18,Fano resonances and band structure of two dimensional photonic structures,"We show that the frequency spectrum of two dimensional photonic crystals is
strongly influenced by Fano resonances which can be excited already in the
linear array of dielectric cylinders. To support this claim, we calculate the
transmission of electromagnetic wave through linear array of dielectric
cylinders and show that frequencies of observed Fano resonances coincides with
position of narrow frequency bands found in the spectra of corresponding
two-dimensional photonic crystals. Split of frequency band or overlap of two
bands, observed in the band structure of photonic structures are also
associated with Fano resonances.",1509.05513v1
2015-09-21,Resonances for 1D half-line periodic operators: II. Special case,"The present paper is devoted to the study of resonances for a $1$D
Schr\""{o}dinger operator with truncated periodic potential. Precisely, we
consider the half-line operator $H^{\mathbb N}=-\Delta +V$ and $H^{\mathbb
N}_{L}= -\Delta + V1_{[0, L]}$ acting on $\ell^{2}(\mathbb N)$ with Dirichlet
boundary condition at $0$ with $L \in \mathbb N$. We describe the resonances of
$H^{\mathbb N}_{L}$ near the boundary of the essential spectrum of $H^{\mathbb
N}$ as $L \rightarrow +\infty$ under a special assumption.\\ The present paper
is in a series of our research papers on resonances",1509.06133v1
2015-09-30,Nucleon Resonances Near 2 GeV,"The nucleon resonances near 2 GeV are investigated through the $\Sigma$(1385)
and $\Lambda(1520)$ photoproductions within a Regge-plus-resonance approach
based on the new experimental data released by the CLAS Collaboration. The
$\Delta(2000)$ and the $N(2120)$ are found essential to reproduce the
experimental data and should be assigned as second $[\Delta 5/2^+]$ and third
$[N3/2^-]$ in the constituent quark model, respectively. A calculation of the
binding energy and decay pattern supports that the $N(1875)$, which is listed
in the PDG as the third $N3/2^-$ nucleon resonance instead of the $N(2120)$, is
from the $\Sigma(1385)K$ interaction rather than a three quark state.",1509.09025v1
2015-10-22,Ratchet transport of a two-dimensional electron gas at cyclotron resonance,"The driving of charge carriers confined in a quantum well lacking the center
of space inversion by an alternating electric field leads to the formation of a
direct electric current. We develop a microscopic theory of such a quantum
ratchet effect for quantum wells subjected to a static magnetic field. We show
that the ratchet current emerges for a linearly polarized alternating electric
field as well as a rotating electric field and drastically increases at the
cyclotron resonance conditions. For the magnetic field tilted with respect to
the quantum well normal, the ratchet current contains an additional resonance
at the first subharmonic of the cyclotron resonance.",1510.06625v1
2015-10-29,Random Perturbations of a Periodically Driven Nonlinear Oscillator: Escape from a resonance zone,"The phase space for a periodically driven nonlinear oscillator consists of
many resonance zones. Let the strength of periodic excitation and the strength
of the damping be indexed by a small parameter $\varepsilon$. It is well known
that, as $\varepsilon \to 0$, the measure of the set of initial conditions
which lead to 'capture in a resonance zone' goes to zero. In this paper we
study the effect of weak noise on the escape from a resonance zone.",1510.08919v2
2015-11-04,Two-field optical methods to control magnetic Feshbach resonances,"Using an optically-trapped mixture of the two lowest hyperfine states of a
$^6$Li Fermi gas, we observe two-field optical tuning of the narrow Feshbach
resonance by up to 3 G and an increase in spontaneous lifetime near the broad
resonance from $0.5$ ms to $0.4$ s. We present a new model of light-induced
loss spectra, employing continuum-dressed basis states, that agrees in shape
and magnitude with measurements for both broad and narrow resonances.",1511.01403v1
2015-11-07,In-resonator variation of waveguide cross-sections for dispersion control of aluminum nitride micro-rings,"We propose and demonstrate a dispersion control technique by combination of
different waveguide cross sections in an aluminum nitride micro-ring resonator.
Narrow and wide waveguides with normal and anomalous dispersion, respectively,
are linked with tapering waveguides and enclosed in a ring resonator to produce
a total dispersion near zero. The mode-coupling in multimoded waveguides is
also effectively suppressed. This technique provides new degrees of freedom and
enhanced flexibility in engineering the dispersion of microcomb resonators.",1511.02397v1
2016-01-04,Pulse chirp increasing pulse compression followed by positive resonant radiation in fibers,"Pulse self-compression followed by the generation of resonant radiation is a
well known phenomenon in non-linear optics. Resonant radiation is important as
it allows for efficient and tunable wavelength conversion. We vary the chirp of
the initial pulse and find in simulations and experiments that a small positive
chirp enhances the pulse compression and strongly increases the generation of
resonant radiation. This result corroborates previously published simulation
results indicating an improved degree of pulse compression for a small positive
chirp [1]. It also demonstrates how pulse evolution can be studied without
cutting back the fiber.",1601.00476v1
2016-01-21,Fine Structure of Cyclotron Resonance in a Two-Dimensional Electron System,"It is established that cyclotron resonance (CR) in a high-quality GaAs/AlGaAs
two-dimensional electron system (2DES) originates as a \textit{pure} resonance,
that does not hybridize with dimensional magnetoplasma excitations. The
magnetoplasma resonances form a fine structure of the CR. The observed fine
structure of the CR results from the interplay between coherent radiative and
incoherent collisional mechanisms of 2D plasma relaxation. We show that the
range of 2DES filling factors from which the phenomenon arises is intimately
connected to the fundamental fine-structure constant.",1601.05544v1
2016-01-25,Dynamical Coupling of Pygmy and Giant Resonances in Relativistic Coulomb Excitation,"We study the Coulomb excitation of pygmy dipole resonances (PDR) in heavy ion
reactions at 100 MeV/nucleon and above. The reactions 68Ni+197Au and 68Ni+208Pb
are taken as a practical examples. Our goal is to address the question of the
influence of giant resonances on the PDR as the dynamics of the collision
evolves. We show that the coupling to the giant resonances affects considerably
the excitation probabilities of the PDR, a result that indicates the need of an
improved theoretical treatment of the reaction dynamics at these bombarding
energies.",1601.06469v2
2016-01-28,On Anomalous Localized Resonance for the Elastostatic System,"We consider the anomalous localized resonance due to a plasmonic structure
for the elastostatic system in R^2. The plasmonic structure takes a general
core-shell-matrix form with the metamaterial located in the shell. If there is
no core, we show that resonance occurs for a very broad class of sources. If
the core is nonempty and of an arbitrary shape, we show that there exists a
critical radius such that anomalous localized resonance (ALR) occurs. Our
argument is based on a variational technique by making use of the primal and
dual variational principles for the elastostatic system, along with the
construction of suitable test functions.",1601.07744v1
2016-02-08,Capture into resonance and phase space dynamics in optical centrifuge,"The process of capture of a molecular enesemble into rotational resonance in
the optical centrifuge is investigated. The adiabaticity and phase space
incompressibility are used to find the resonant capture probability in terms of
two dimensionless parameters P1,P2 characterising the driving strength and the
nonlinearity, and related to three characteristic time scales in the problem.
The analysis is based on the transformation to action-angle variables and the
single resonance approximation, yielding reduction of the three-dimensional
rotation problem to one degree of freedom. The analytic results for capture
probability are in a good agreement with simulations. The existing experiments
satisfy the validity conditions of the theory.",1602.02604v1
2016-03-01,Vacuum Rabi Splitting in Nanomechanical QED System with Nonlinear Resonator,"Considering the intrinsic nonlinearity in a nanomechanical resonator coupled
to a charge qubit, vacuum Rabi splitting effect is studied in a nanomechanical
QED (qubit-resonator) system. A driven nonlinear Jaynes-Cummings model
describes the dynamics of this qubit-resonator system. Using quantum regression
theorem and master equation approach, we have calculated the two-time
correlation spectrum analytically. In the weak driving limit, these analytical
results clarify the influence of the driving strength and nonlinearity
parameter on the correlation spectrum. Also, numerical calculations confirm
these analytical results.",1603.00215v1
2016-03-02,Ferromagnetic resonance in submicron permalloy stripes,"We present the results of systematic experimental investigations and
micromagnetic simulations for the ferromagnetic resonance in rectangular
permalloy microstripes. It is shown that the resonant magnetization
oscillations have a complex spatial structure including a quasi-homogeneous
precession, lateral spin-wave resonances and localized edge modes, which
strongly depend on sample orientation in an external magnetic field.",1603.00694v1
2016-03-07,Q-factor enhancement in all-dielectric anisotropic nanoresonators,"It is proposed and demonstrated that Q-factor of optical resonators can be
significantly enhanced by introducing an extra anisotropic cladding. We study
the optical resonances of all-dielectric core-shell nanoresonators and reveal
that radially anisotropic claddings can be employed to squeeze more energy into
the core area, leading to stronger light confinement and thus significant
Q-factor enhancement. We further show that the required homogenous claddings of
unusual anisotropy parameters can be realized through all-dielectric
multi-layered isotropic structures, which offers realistic extra flexibilities
of resonance manipulations for optical resonators.",1603.02111v1
2016-03-08,Level-crossing and modal structure in microdroplet resonators,"We fabricate a liquid-core liquid-clad microcavity that is coupled to a
standard tapered fiber, and then experimentally map the whispering-gallery
modes of this droplet resonator. The shape of our resonator is similar to a
thin prolate spheroid, which makes space for many high-order transverse modes,
suggesting that some of them will share the same resonance frequency. Indeed,
we experimentally observe that more than half of the droplet's modes have a
sibling having the same frequency (to within linewidth) and therefore
exhibiting a standing interference-pattern.",1603.02446v1
2016-04-01,Feshbach resonances and weakly bound molecular states of boson-boson and boson-fermion NaK pairs,"We study theoretically magnetically induced Feshbach resonances and
near-threshold bound states in isotopic NaK pairs. Our calculations accurately
reproduce Feshbach spectroscopy data on Na$^{40}$K and explain the origin of
the observed multiplets in the p-wave [Phys. Rev. A 85, 051602(R) (2012)]. We
apply the model to predict scattering and bound state threshold properties of
the boson-boson Na$^{39}$K and Na$^{41}$K systems. We find that the Na$^{39}$K
isotopic pair presents broad magnetic Feshbach resonances and favorable
ground-state features for producing non-reactive polar molecules by two-photon
association. Broad s-wave resonances are also predicted for Na$^{41}$K
collisions.",1604.00234v1
2016-04-09,Determination of the compositeness of resonances from decays: the case of the $B^0_s\to J/ψf_1(1285)$,"We develop a method to measure the amount of compositeness of a resonance,
mostly made as a bound state of two hadrons, by simultaneously measuring the
rate of production of the resonance and the mass distribution of the two
hadrons close to threshold. By using different methods of analysis we conclude
that the method allows one to extract the value of 1-Z with about $0.1$ of
uncertainty. The method is applied to the case of the $\bar B^0_s \to J/\psi
f_1(1285)$ decay, by looking at the resonance production and the mass
distribution of $K \bar K^*$.",1604.02574v1
2016-06-24,"Design and Experimental Characterization of Spiral Resonator variants-TTSR , NBSR","In this paper we have carried out numerical simulation and experimental
characterization of two variants of SR (Spiral resonator) viz. TTSR (Two-Turn
Spiral Resonator) and NBSR (Non Bianisotropic spiral resonator). The numerical
simulation of these develop magnetic inclusion structures are done with
commercially available Finite Element Method (FEM) based Ansys HFSS-13
simulation software, and transmission experiment using S-parameter retrieval
technique. The experimental characterization of those fabricated structures is
used in the parallel plate waveguide experiment (not reported earlier) and then
validate our experimental results with the Ansys HFSS-13 simulation software;
which in not available in any published literature.",1606.08737v1
2016-07-05,Waveguide photonic limiters based on topologically protected resonant modes,"We propose a concept of chiral photonic limiters utilising topologically
protected localised midgap defect states in a photonic waveguide. The chiral
symmetry alleviates the effects of structural imperfections and guaranties a
high level of resonant transmission for low intensity radiation. At high
intensity, the light-induced absorption can suppress the localised modes, along
with the resonant transmission. In this case the entire photonic structure
becomes highly reflective within a broad frequency range, thus increasing
dramatically the damage threshold of the limiter. Here we demonstrate
experimentally the principle of operation of such photonic structures using a
waveguide consisting of coupled dielectric microwave resonators.",1607.01213v1
2016-07-07,Looking for bound states and resonances in the $η^\prime K\bar K$ system,"Motivated by the continuous experimental investigations of $X(1835)$ in
three-body decay channels like $\eta^\prime \pi^+ \pi^-$, we investigate the
$\eta^\prime K \bar K$ system with the aim of searching for bound states and/or
resonances when the dynamics involved in the $K\bar K$ subsystem can form the
resonances: $f_0(980)$ in isospin 0 or $a_0(980)$ in isospin 1. For this, we
solve the Faddeev equations for the three-body system. The input two-body
$t$-matrices are obtained by solving Bethe-Salpeter equations in a coupled
channel formalism. As a result, no signal of a three-body bound state or
resonance is found.",1607.02102v1
2016-07-13,Calculation of Regge trajectories of strange resonances and identification of the K0*(800) as a non-ordinary meson,"We review how the Regge trajectory of an elastic resonance can be obtained
just from its pole position and coupling, using a dispersive formalism. This
allows us to deal correctly with the finite widths of resonances in Regge
trajectories. In this way we can calculate the Regge trajectories for the
$K^*(892)$, $K_1(1400)$ and $K^*_0(1430)$, obtaining ordinary linear Regge
trajectories, expected for $q \bar q$ resonances. In contrast, for the
$K^*_0(800)$ meson, the resulting Regge trajectory is non-linear and with much
smaller slope, strongly supporting its non-ordinary nature.",1607.03750v1
2016-07-14,Resonance production in Pomeron-Pomeron collisions at the LHC,"A model for Pomeron-Pomeron total cross section in the resonance region
$\sqrt{M^{2}} \le$ 5 GeV is presented. This model is based on Regge poles from
the Pomeron and two different $f$ trajectories, and includes the isolated
f$_{0}(500)$ resonance in the region $\sqrt{M^{2}}\lesssim 1$ GeV. A slowly
varying background is included. The presented Pomeron-Pomeron cross section is
not directly measurable, but is an essential ingredient for calculating
exclusive resonance production at the LHC.",1607.04496v1
2016-07-21,Perturbation-Free Prediction of Resonance-Assisted Tunneling in Mixed Regular--Chaotic Systems,"For generic Hamiltonian systems we derive predictions for dynamical tunneling
from regular to chaotic phase-space regions. In contrast to previous
approaches, we account for the resonance-assisted enhancement of
regular-to-chaotic tunneling in a non-perturbative way. This provides the
foundation for future semiclassical complex-path evaluations of
resonance-assisted regular-to-chaotic tunneling. Our approach is based on a new
class of integrable approximations which mimic the regular phase-space region
and its dominant nonlinear resonance chain in a mixed regular--chaotic system.
We illustrate the method for the standard map.",1607.06477v1
2016-07-22,Phonon-Josephson resonances in atomtronic circuits,"We study the resonant excitation of sound modes from Josephson oscillations
in Bose-Einstein condensates. From the simulations for various setups using the
Gross-Pitaevskii mean-field equations and Josephson equations we observe
additional tunneling currents induced by resonant phonons. The proposed
experiment may be used for spectroscopy of phonons as well as other low-energy
collective excitations in Bose-Einstein condensates. We also argue that the
observed effect may mask the observation of Shapiro resonances if not carefully
controlled.",1607.06590v2
2016-10-28,The unexplored landscape of two-body resonances,"We propose a strategy for searching for theoretically-unanticipated new
physics which avoids a large trials factor by focusing on experimental
strengths. Searches for resonances decaying into pairs of visible particles are
experimentally very powerful due to the localized mass peaks and have a rich
history of discovery. Yet, due to a focus on subsets of theoretically-motivated
models, the landscape of such resonances is far from thoroughly explored. We
survey the existing set of searches, identify untapped experimental
opportunities and discuss the theoretical constraints on models which would
generate such resonances.",1610.09392v1
2017-03-06,Resonances of 4-th Order Differential Operators,"We consider fourth order ordinary differential operator with compactly
supported coefficients on the line. We determine asymptotics of the number of
resonances in complex discs at large radius. We consider resonances of an
Euler-Bernoulli operator on the real line with the positive coefficients which
are constants outside some finite interval. We show that the Euler-Bernoulli
operator has no eigenvalues and resonances iff the positive coefficients are
constants on the whole axis.",1703.01784v2
2017-03-15,Development of optical resonant cavities for laser-Compton scattering,"We have been developing optical resonant cavities for laser-Compton
scattering experiment at the Accelerator Test Facility in KEK. The main subject
of the R&D is to increase laser pulse energy by coherently accumulating the
pulses in an optical resonant cavity. We report previous results, current
status and future prospects, including a new idea of an optical resonant
cavity.",1703.05742v1
2017-03-23,Topology of Pollicott-Ruelle resonant states,"We prove that the twisted De Rham cohomology of a flat vector bundleover some
smooth manifold is isomorphic to the cohomology of invariant
Pollicott--Ruelleresonant states associated with Anosov and Morse--Smale flows.
As a consequence, weobtain generalized Morse inequalities for such flows. In
the case of Morse--Smale flows,we relate the resonances lying on the imaginary
axis with the twisted Fuller measuresused by Fried in his work on Reidemeister
torsion. In particular, when V is a nonsingularMorse-Smale flow, we show that
the Reidemeister torsion can be recovered from the onlyknowledge of dynamical
resonances on the imaginary axis by expressing the torsion as azeta regularized
infinite product of these resonances.",1703.08037v1
2017-03-28,Resonance State Wave Functions of $^{15}$Be using Supersymmetric Quantum Mechanics,"The theoretical procedure of supersymmetric quantum mechanics is adopted to
generate the resonance state wave functions of the unbound nucleus $^{15}$Be.
In this framework, we used a density dependent M3Y microscopic potential and
arrived at the energy and width of the 1.8 MeV (5/2$^+$) resonance state. We
did not find any other nearby resonances for $^{15}$Be. It becomes apparent
that the present framework is a powerful tool to theoretically complement the
increasingly important accelerator based experiments with unbound nuclei.",1703.09448v2
2017-08-21,Hadronic resonances with exotic electric charge,"We classify the meson and baryon long lived resonances considering quarks
with electric charge 5/3 and $-4/3$ (in units of $\vert e\vert$) predicted by
some 3-3-1 models. Some of these exotic resonances have the usual electric
charges $0,\pm1$, others have $\pm(3,4,5)$, and the lightest ones decaying only
into leptons plus known resonances. We propose another heavy $SU(3)_H$ global
symmetry under which hadrons involving only exotic quarks can be constructed.",1708.06285v2
2018-02-05,Convergence and completeness for square-well Stark resonant state expansions,"In this paper we investigate the completeness of the Stark resonant
eigenstates for a particle in a square-well potential. We find that the
resonant state expansions for target functions converge inside the potential
well and that the existence of this convergence does not depend on the depth of
the potential well. By analyzing the asymptotic form of the terms in these
expansions we prove some results on the relation between smoothness of target
functions and the rate of convergence of the corresponding resonant state
expansion.",1802.01317v1
2018-02-12,Plasmonic parametric resonance,"We introduce the concept of Plasmonic Parametric Resonance (PPR) as a novel
way to amplify high angular momentum plasmonic modes of nanoparticles by means
of a simple uniform optical pump. In analogy with parametric resonance in
dynamical systems, PPR originates from the temporal modulation of one of the
parameters governing the evolution of the state of the system. As opposed to
conventional localized surface plasmon resonances, we show that in principle
any plasmonic mode of arbitrarily high order is accessible by PPR with a
spatially uniform optical pump. Moreover, in contradistinction with other
mechanisms of plasmonic amplification, the coherent nature of PPR lends itself
to a more straightforward experimental detection approach. The threshold
conditions for PPR are analytically derived. Schemes of experimental
realization and detection are also discussed.",1802.04239v1
2018-02-13,"Platonic crystal with low-frequency locally resonant snail structures. Wave trapping, transmission amplification and shielding","We propose a new type of platonic crystal. The proposed microstructured plate
includes snail resonators with low-frequency resonant vibrations. The
particular dynamic effect of the resonators are highlighted by a comparative
analysis of dispersion properties of homo- geneous and perforated plates.
Analytical and numerical estimates of classes of standing waves are given and
the analysis on a macrocell shows the possibility to obtain localization, wave
trapping and edge waves. Applications include transmission amplification within
two plates separated by a small ligament. Finally we proposed a design
procedure to suppress low frequency flexural vibration in an elongated plate
implementing a by-pass system re- routing waves within the mechanical system.",1802.08316v1
2018-02-27,Resonant states in double and triple quantum wells,"The full set of resonant states in double and triple quantum well/barrier
structures is investigated. This includes bound, anti-bound and normal resonant
states which are all eigensolutions of Schrodinger's equation with generalized
outgoing wave boundary conditions. The transformation of resonant states and
their transitions between different subgroups as well as the role of each
subgroup in observables, such as the quantum transmission, is analyzed. The
quantum well potentials are modeled by Dirac delta functions; therefore, as
part of this study, the well-known problem of bound states in delta-like
potentials is also revisited.",1802.09855v2
2018-04-16,Instability of resonances under Stark perturbations,"Let $H^{\varepsilon}=-\frac{d^2}{dx^2}+\varepsilon x +V$, $\varepsilon\geq0$,
on $L^2(\mathbf{R})$. Let $V=\sum_{k=1}^Nc_k|\psi_k\rangle\langle\psi_k|$ be a
rank $N$ operator, where the $\psi_k\in L^2(\mathbf{R})$ are real, compactly
supported, and even. Resonances are defined using analytic scattering theory.
The main result is that if $\zeta_n$, ${\rm Im}\zeta_n<0$, are resonances of
$H^{\varepsilon_n}$ for a sequence $\varepsilon_n\downarrow0$ as $n\to\infty$
and $\zeta_n\to\zeta_0$ as $n\to\infty$, ${\rm Im}\zeta_0<0$, then $\zeta_0$ is
\emph{not} a resonance of $H^0$.",1804.05620v1
2018-11-10,Investigating the hidden-charm and hidden-bottom pentaquark resonances in scattering process,"In the framework of quark delocalization color screening model, both the
hidden-charm and hidden-bottom pentaquark resonances are studied in the
hadron-hadron scattering process. A few narrow pentaquark resonances with
hidden-charm above $4.2$ GeV, and some narrow pentaquark resonances with
hidden-bottom above $11$ GeV are found from corresponding scattering processes.
Besides, the states $N\eta_{c}$, $NJ/\psi$, $N\eta_{b}$ and $N\Upsilon$ with
$IJ^{P}=\frac{1}{2}\frac{1}{2}^{-}$, as well as $NJ/\psi$ and $N\Upsilon$ with
$IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ are all possible to be bound by
channel-coupling calculation. All these heavy pentaquarks are worth searching
in the future experiments.",1811.04260v1
2018-11-14,On multi-point resonant problems on the half-line,"In this work we obtain sufficient conditions for the existence of bounded
solutions of a resonant multi-point second-order boundary value problem, with a
fully differential equation.
  The noninvertibility of the linear part is overcome by a new perturbation
technique, which allows to obtain an existence result and a localization
theorem. Our hypotheses are clearly much less restrictive than the ones
existent in the literature and, moreover, they can be applied to higher order,
resonant or non-resonant, boundary value problems defined on the half-line or
even on the real line.",1811.06117v1
2018-11-19,Controllable coupled-resonator-induced transparency in a dual-recycled Michelson interferometer,"We theoretically and experimentally study the effect of the
coupled-resonator-induced transparency in the Michelson interferometer with the
dual-recycled configuration, which is equivalent to the adjustable coupled
resonator. The coupling strength, corresponding to the splitting of the
reflection spectrum and associated with the width of the
coupled-resonator-induced transparent window,can be controlled by adjusting the
arm lengths, i.e., the relative phase of the interference arms on the 50/50
beam splitter. Thus, this tunability of the coupling strength can be very fast,
and the absorptive and dispersive properties can be effectively controlled.
This work provides a new system to coherently control and storage optical
field.",1811.07444v1
2019-05-12,Stereodynamical control of a quantum scattering resonance in cold molecular collisions,"Cold collisions of light molecules are often dominated by a single partial
wave resonance. For the rotational quenching of HD(v=1,j=2) by collisions with
ground state para-H2, the process is dominated by a single L=2 partial wave
resonance centered around 0.1 K. Here, we show that this resonance can be
switched on or off simply by appropriate alignment of the HD rotational angular
momentum relative to the initial velocity vector, thereby enabling complete
control of the collision outcome.",1905.04765v1
2010-05-03,Individual and Collective Behavior of Small Vibrating Motors Interacting Through a Resonant Plate,"We report on experiments of many small motors -- cell phone vibrators --
glued to and interacting through a resonant plate. We find that individual
motors interacting with the plate demonstrate hysteresis in their steady-state
frequency due to interactions with plate resonances. For multiple motors
running simultaneously, the degree of synchronization between motors increases
when the motors' frequencies are near a resonance of the plate, and the
frequency at which the motors synchronize shows a history dependence.",1005.0420v1
2010-05-20,Dynamical electric dipole theory for quantitatively describing coupled split-ring resonators,"Metallic split-ring resonators possess dominant electric dipoles as well as
considerable magnetic dipoles under proper excitations. Full-wave numerical
approaches are frequently employed to simulate adjacent split-ring resonators,
but simulations cannot explain the underlying physics. An analytical theory
based on a dynamic electric dipole approximation is developed here. Detailed
theory-simulation comparisons demonstrate that this theory can
\textit{quantitatively} describe the interaction strength of coupled
split-ring-resonators under certain circumstances.",1005.3819v1
2010-05-26,The absolute position of a resonance peak,"It is common practice in scattering theory to correlate between the position
of a resonance peak in the cross section and the real part of a complex energy
of a pole of the scattering amplitude. In this work we show that the resonance
peak position appears at the absolute value of the pole's complex energy rather
than its real part. We further demonstrate that a local theory of resonances
can still be used even in cases previously thought impossible.",1005.4756v1
2010-05-28,Reduced frequency noise in superconducting resonators,"We report a reduction of the frequency noise in coplanar waveguide
superconducting resonators. The reduction of 7 dB is achieved by removing the
exposed dielectric substrate surface from the region with high electric fields
and by using NbTiN. In a model-analysis the surface of NbTiN is found to be a
negligible source of noise, experimentally supported by a comparison with NbTiN
on SiOx resonators. The reduction is additive to decreasing the noise by
widening the resonators.",1005.5394v1
2013-08-14,Electrical Detection of Spin Wave Resonance in a Permalloy Thin Strip,"We investigated the microwave-induced DC response of spin wave resonance
(SWR) in a permalloy thin strip via electrical detection. Our experimental
results obtained by sweeping the external field reveal that: 1. the amplitude
of SWR signals depend on the direction of external field and, 2. unlike the DC
response of ferromagnetic resonance, SWR spectra are always anti-symmetrical.
The spin dynamics are discussed based on these unusual signals in resonant
condition.",1308.3069v1
2013-08-20,Floquet Weyl Semimetal Induced by Off-Resonant Light,"We propose that a Floquet Weyl semimetal state can be induced in
three-dimensional topological insulators, either nonmagnetic or magnetic, by
the application of off-resonant light. The virtual photon processes play a
critical role in renormalizing the Dirac mass and so resulting in a topological
semimetal with vanishing gap at Weyl points. The present mechanism via
off-resonant light is quite different from that via on-resonant light, the
latter being recently suggested to give rise to a Floquet topological state in
ordinary band insulators.",1308.4266v2
2014-03-11,Coulomb Pairing and Double Photoionization in Aromatic Hydrocarbons,"Recently reported anomalies in the double-photonionization spectra of the
aromatic molecules partially deuterated benzene, naphthalene, anthracene,
pentacene, azulene, phenanthrene, pyrene and coronene are attributed to
Coulomb-pair resonances of pi electrons. The properties of the resonance in
benzene are investigated in detail. The linear behavior in the 2+/1+ ion ratio
above the resonance is attributed to a two-electron transition associated with
excitation from the ground state to a two-electron continuum. A similar
explanation accounts for the linear behavior seen in the pentagonal rings
pyrrole, furan, selenophene and thiophene which do not display resonance peaks.",1403.2640v1
2014-03-16,The finite size effect on resonance poles,"The effect of the finite size of an array of scatterers on the position of
the resonance poles of the scattered amplitudes is studied. This effect must be
studied because in reality, an infinite array cannot be realized. In
particular, it is expected that for a finite array of scatterers, the imaginary
parts of the resonance poles (resonance widths) cannot vanish as is the case
for an infinite double array admitting bound states in the radiation continuum.",1403.3917v2
2014-03-22,Existence of Dirac resonances in the semi-classical limit,"We study the existence of quantum resonances of the three-dimensional
semiclassical Dirac operator perturbed by smooth, bounded and real-valued
scalar potentials $V$ decaying like $\langle x \rangle ^{-\d}$ at infinity for
some $\d >0$. By studying analytic singularities of a certain distribution
related to $V$ and by combining two trace formulas, we prove that the perturbed
Dirac operators possess resonances near $\sup V + 1$ and $\inf V -1$. We also
provide a lower bound for the number of resonances near these points expressed
in terms of the semiclassical parameter.",1403.5653v1
2014-03-29,Instability of pre-existing resonances in the DC Stark effect vs. stability in the AC Stark effect,"For atoms described by a 1-dimensional Friedrichs model we present the
following result: pre-existing resonances, when subjected to a small constant
electric field (DC Stark effect), are unstable in the weak field limit. In
contrast, pre-existing resonances under the influence of a small time-periodic
electric field (AC Stark effect) are stable in this limit. This article is a
review of our results in ""Instability of pre-existing resonances under a small
constant electric field"", arXiv:1310.4745.",1403.7675v1
2016-11-10,Search for a high mass diphoton resonance using the ATLAS detector,"A search for new spin-0 resonances decaying into two photons in the ATLAS
experiment at the LHC is described. The analysis is based on $pp$ collision
data at $\sqrt{s}$=13 TeV corresponding to integrated luminosities of 3.2/fb
and 12.2/fb recorded in 2015 and 2016, respectively. A deviation from the
Standard Model background-only hypothesis corresponding to 3.4 standard
deviations is observed in the 2015 data for a resonance mass hypothesis of 730
GeV. No significant excess at such mass over the background expectation is
observed in the 2016 data. Limits on the production cross section times
branching ratio to two photons of such resonances are reported.",1611.03308v1
2016-11-30,Quantum transport in coupled resonators enclosed synthetic magnetic flux,"Quantum transport properties are instrumental to understanding quantum
coherent transport processes. Potential applications of quantum transport are
widespread, in areas ranging from quantum information science to quantum
engineering, and not restricted to quantum state transfer, control and
manipulation. Here, we study light transport in a ring array of coupled
resonators enclosed synthetic magnetic flux. The ring configuration, with an
arbitrary number of resonators embedded, forms an two-arm Aharonov-Bohm
interferometer. The influence of magnetic flux on light transport is
investigated. Tuning the magnetic flux can lead to resonant transmission, while
half-integer magnetic flux quantum leads to completely destructive interference
and transmission zeros in an interferometer with two equal arms.",1611.10015v1
2017-01-19,Light-matter interactions in multi-element resonators,"We investigate structural resonances in multi-element optical resonators and
provide a roadmap for the description of the interaction of single extended
cavity modes with quantum emitters or mechanical resonators. Using a first
principle approach based on the transfer matrix formalism we analyze, both
numerically and analytically, the static and dynamical properties of three- and
four-mirror cavities. We investigate in particular conditions under which the
confinement of the field in specific subcavities allows for enhanced
light-matter interactions in the context of cavity quantum electrodynamics and
cavity optomechanics.",1701.05373v2
2017-01-20,Two-step pulse observation to improve resonance contrast for coherent population trapping atomic clock,"We study resonance contrast by a two-step pulse observation method to enhance
the frequency stability of coherent population trapping (CPT) atomic clocks.
The proposed method is a two-step Raman--Ramsey scheme with low intensity
during resonance observation and high intensity after the observation. This
method reduces the frequency variation in the light intensity and maintains a
high signal-to-noise ratio. The resonance characteristics were calculated by
density matrix analysis of a $\Lambda$-type three-level system that was modeled
on the $^{133}$Cs D1 line, and the characteristics were also measured using a
vertical-cavity surface-emitting laser and a Cs vapor cell.",1701.05696v1
2017-01-23,Is there a narrow $N(1685)$?,"The helicity-dependent observable $E$ for the reaction $\gamma d\to \eta n
(p)$ with a spectator proton was recently measured by the A2 Collaboration at
MAMI in Mainz. The data were interpreted as further evidence for a narrow
resonance with spin and parity $J^P=1/2^+$ ($P_{11}$ wave). However, a full
partial wave analysis without any narrow resonance leads to an excellent
description of the data, imposing a narrow resonance with the properties
suggested by the A2 Collaboration leads to a significant deterioration of the
fit quality: there is no need for a narrow resonance.",1701.06387v2
2017-01-27,Fano Resonances in a Photonic Crystal Covered with a Perforated Gold Film and its Application to Biosensing,"Optical properties of the photonic crystal covered with a perforated metal
film were investigated and the existence of the Fano-type resonances was shown.
The Fano resonances originate from the interaction between the optical Tamm
state and the waveguide modes of the photonic crystal. It manifests itself as a
narrow dip in a broad peak in the transmission spectrum related to the optical
Tamm state. The design of a sensor based on this Fano resonance that is
sensitive to the change of the environment refractive index is suggested.",1701.08090v1
2008-07-04,The occurrence of a triple -1 resonance in the standard singularity analysis,"Any careful singularity analysis of the Mixmaster Universe uncovers the
instance of a triple -1 resonance. The Mixmaster Universe does not exhibit a
closed-form solution and so a correct interpretation of the meaning of the
triple -1 resonance is difficult. We provide a system of differential equations
for which both a closed-form solution and a triple -1 resonance exist.",0807.0763v1
2008-07-16,Terahertz Metamaterials with Semiconductor Split-Ring Resonators for Magnetostatic Tunability,"We studied a metasurface constituted as a periodic array of semiconductor
split-ring resonators. The resonance frequencies of the metasurface excited by
normally incident light were found to be continuously tunable in the terahertz
regime through an external magnetostatic field of suitable orientation. As such
metasurfaces can be assembled into 3D metamaterials, the foregoing conclusion
also applies to metamaterials comprising semiconductor split-ring resonators.",0807.2495v2
2008-07-16,Refractive Index Enhancement with Vanishing Absorption in an Atomic Vapor,"We report a proof-of-principle experiment where the refractive index of an
atomic vapor is enhanced while maintaining vanishing absorption of the beam.
The key idea is to drive alkali atoms in a vapor with appropriate control
lasers and induce a gain resonance and an absorption resonance for a probe beam
in a two-photon Raman configuration. The strength and the position of these two
resonances can be manipulated by changing the parameters of the control lasers.
By using the interference between these two resonances, we obtain an enhanced
refractive index without an increase in the absorption.",0807.2584v1
2009-12-09,Two-phonon polaron resonances in self-assembled quantum dots,"We study the second-order polaronic resonance between 2-LO-phonon states and
p-shell electron states in a quantum dot. We show that the spectrum in the
resonance area can be quantitatively reproduced by a theoretical model using
only standard material constants, without any free parameters. We propose also
a perturbative approach to the problem based on a quasi-degenerate perturbation
theory. This method not only considerably reduces the numerical complexity
without considerable loss of accuracy but also gives some insight into the
structure and origin of the resonance spectrum.",0912.1707v2
2009-12-14,Magnetic Faraday rotation in lossy photonic structures,"Magnetic Faraday rotation is widely used in optics and MW. In uniform
magneto-optical materials, this effect is very weak. One way to enhance it is
to incorporate the magnetic material into a high-Q optical resonator. One
problem with magneto-optical resonators is that along with Faraday rotation,
the absorption and linear birefringence can also increase dramatically,
compromising the device performance. Another problem is strong ellipticity of
the output light. We discuss how the above problems can be addressed in the
cases of optical microcavities and a slow wave resonators. We show that a slow
wave resonator has a fundamental advantage when it comes to Faraday rotation
enhancement in lossy magnetic materials.",0912.2612v1
2009-12-14,Confinement resonances in photoionization of endohedral atoms: a myth or reality?,"We demonstrate that the structure of confinement resonances in the
photoionization cross section of an endohedral atom is very sensitive to the
mean displacement <a> of the atom from the cage center. The resonances are
strongly suppressed if 2<a> exceeds the photoelectron half-wavelength. We
explain the results of recent experiments which contradict the earlier
theoretical predictions on the existence of confinement resonances in
particular endohedral systems.",0912.2690v2
2009-12-23,"$πΞ$ Correlations: an Interweaving of Resonance Interaction, Channel Coupling and Coulomb Effects","A method is presented for analysis of correlation function of two
non-identical particles with strong and Coulomb interactions, resonance
formation, channel coupling and spin structure. For resonance reactions we
derive a formula giving the small distance contribution to the correlation
function. The formalism is used to analyze the preliminary RHIC data on
$\pi^{\pm} \Xi^{\mp}$ correlation measurements. The $\Xi^{*}(1530)$ resonance
is successfully described. The $\pi \Xi$ source size is obtained.",0912.4693v2
2011-11-04,Search for a Narrow ttbar Resonance in ppbar Collisions at sqrt{s}=1.96 TeV,"We report a search for a narrow ttbar resonance that decays into a
lepton+jets final state based on an integrated luminosity of 5.3/fb of
proton-antiproton collisions at sqrt{s}=1.96 TeV collected by the D0
Collaboration at the Fermilab Tevatron Collider. We set upper limits on the
production cross section of such a resonance multiplied by its branching
fraction to ttbar which we compare to predictions for a leptophobic topcolor Z'
boson. We exclude such a resonance at the 95% confidence level for masses below
835 GeV.",1111.1271v1
2011-11-05,Top quark as a resonance,"We suggest the description of the dressed fermion propagator with parity
non-conservation in the form with separated positive and negative energy poles.
We found general form of the $\gamma$-matrix off-shell projectors and
corresponding resonance factors. The parity violation leads to deviation of
resonance factors from the naive Breit--Wigner form and to appearance of
non-trivial spin corrections. However, for top quark with SM vertex the
resonance factor returns to the standard one due to $\Gamma/m\ll1$.",1111.1284v3
2012-01-23,Resonant Adiabatic Passage with Three Qubits,"We investigate the non-adiabatic implementation of an adiabatic quantum
teleportation protocol, finding that perfect fidelity can be achieved through
resonance. We clarify the physical mechanisms of teleportation, for three
qubits, by mapping their dynamics onto two parallel and mutually-coherent
adiabatic passage channels. By transforming into the adiabatic frame, we
explain the resonance by analogy with the magnetic resonance of a spin-1/2
particle. Our results establish a fast and robust method for transferring
quantum states, and suggest an alternative route toward high precision quantum
gates.",1201.4829v1
2012-04-02,Statistics of resonances in one-dimensional disordered systems,"The paper is devoted to the problem of resonances in one-dimensional
disordered systems. Some of the previous results are reviewed and a number of
new ones is presented. These results pertain to different models (continuous as
well as lattice) and various regimes of disorder and coupling strength. In
particular, a close connection between resonances and the Wigner delay time is
pointed out and used to obtain information on the resonance statistics.",1204.0441v2
2012-04-23,Compact RF resonator for cryogenic ion traps,"We report on the investigation and implementation of a lumped-component,
radio-frequency resonator used in a cryogenic vacuum environment to drive an
ion trap. The resonator was required to achieve the voltages necessary to trap
(about 100 V), while dissipating as little power as possible (< 250 mW).
Ultimately a voltage gain of 100 was measured at 5.7 K. Single calcium ions
were confined in a trap driven by this device, providing proof of successful
resonator operation at low temperature.",1204.5004v2
2012-04-26,Unexpected resonant response in [Fe(001)/Cr(001)]_(10) /MgO(001) multilayers in magnetic field,"We observed unexpected resonant response in [Fe/Cr]_(10) multilayers
epitaxially grown on MgO(100) substrates which exists only when both ac current
and dc magnetic field are simultaneously applied. The magnitude of the
resonances is determined by the multilayer magnetization proving their
intrinsic character. The reduction of interface epitaxy leads to non-linear
dependence of the magnitude of resonances on the alternating current density.
We speculate that the existence of the interface transition zone could
facilitate the subatomic vibrations in thin metallic films and multilayers
grown on bulk insulating substrates.",1204.5942v1
2013-09-07,Nanomechanical resonant structures in single-crystal diamond,"With its host of outstanding material properties, single-crystal diamond is
an attractive material for nanomechanical systems. Here, the mechanical
resonance characteristics of freestanding, single-crystal diamond nanobeams
fabricated by an angled-etching methodology are reported. Resonance frequencies
displayed evidence of significant compressive stress in doubly clamped diamond
nanobeams, while cantilever resonance modes followed the expected
inverse-length-squared trend. Q-factors on the order of 104 were recorded in
high vacuum. Results presented here represent initial groundwork for future
diamond-based nanomechanical systems which may be applied in both classical and
quantum applications.",1309.1834v1
2013-09-19,Observing dipolar confinement-induced resonances in waveguides,"We develop a theoretical framework for the quasi-low-dimensional
confinement-induced resonances (CIRs) of particles with the arbitrary
three-dimensional two-body interactions, based on the Huang-Yang
pseudopotential and the treatment of Feshbach resonances. Using this new
approach, we analytically obtain some universal properties of dipolar CIRs in
quasi-one-dimensional (1D) waveguides. We also show that the dipolar CIRs can
be induced by tuning the angle between the dipole moments and the waveguide,
which is experimentally observable in quasi-1D Cr and Dy atomic gases. We
expect that these tilting angle induced CIRs will open up a new simpler way to
control the resonant scatterings in quasi-low-dimensional systems.",1309.4954v1
2014-05-13,Influence of the ESR saturation on the power sensitivity of cryogenic sapphire resonators,"Here, we study the paramagnetic ions behavior in presence of a strong
microwave electromagnetic field sustained inside a cryogenic sapphire
whispering gallery mode resonator. The high frequency measurement resolution
that can be now achieved by comparing two CSOs permit for the first time to
observe clearly the non-linearity of the resonator power sensitivity. These
observations that in turn allow us to optimize the CSO operation, are well
explained by the Electron Spin Resonance (ESR) saturation of the paramagnetic
impurities contained in the sapphire crystal.",1405.3081v1
2014-06-02,Statistics of resonance and non-resonance tunnelling of fermionised cold atoms,"We show that a short-range strong repulsive (contact) interaction between the
particles in the barrier may change the statistics of two-particle tunnelling.
In the case of a resonance of a width $\Gamma$, the effect would be observed if
the time between the two impacts is of order of $\hbar/\Gamma$. The statistics
of non-resonance tunnelling across a broad potential barrier remain unaffected,
which suggests that there is no appreciable delay in the classically forbidden
region.",1406.0464v1
2014-06-13,Slow light microfluidics: a proposal,"The resonant slow light structures created along a thin-walled optical
capillary by nanoscale deformation of its surface can perform comprehensive
simultaneous detection and manipulation of microfluidic components. This
concept is illustrated with a model of a 0.5 millimeter long 5 nm high
triangular bottle resonator created at a 50 micron radius silica capillary
containing floating microparticles. The developed theory shows that the
microparticle positions can be determined from the bottle resonator spectrum.
In addition, the microparticles can be driven and simultaneously positioned at
predetermined locations by the localized electromagnetic field created by the
optimized superposition of eigenstates of this resonator, thus, exhibiting a
multicomponent near field optical tweezers.",1406.3570v1
2014-06-15,Signatures of classical bifurcations in the quantum scattering resonances of dissociating molecules,"A study is reported of the quantum scattering resonances of dissociating
molecules using a semiclassical approach based on periodic-orbit theory. The
dynamics takes place on a potential energy surface with an energy barrier
separating two channels of dissociation. Above the barrier, the unstable
symmetric-stretch periodic orbit may undergo a supercritical pitchfork
bifurcation, leading to a classically chaotic regime. Signatures of the
bifurcation appear in the spectrum of resonances, which have a shorter lifetime
than classically expected. A method is proposed to evaluate semiclassically the
energy and lifetime of the quantum resonances in this intermediate regime.",1406.3825v1
2014-06-24,Noise Effects on birhythmic Josephson Junction coupled to a Resonator,"We study the effect of noise on a Josephson junction that, coupled to a
linear $RLC$ resonator, can oscillate at two frequencies. To establish the
global stability of the attractors, we estimate the position of the separatrix,
an essential information to establish the stability of the attractor for this
multidimensional system, from the analysis of the mean first passage time. We
find that the frequency locked to the resonator is most stable at low bias, and
less stable at high bias, where the resonator exhibits the largest
oscillations. The change in the birhythmic region is dramatic, for the
effective barrier changes of an order of magnitude and the corresponding
lifetime of about seven decades.",1406.6236v1
2016-05-03,Mechanism of the Fano resonance in a planar metamaterials: Analysis from the coupled two-oscillator model,"Mechanism of the Fano resonances in planar metamaterials demonstrate based on
the coupled two-oscillator model. We have described the optical spectrums like
reflectance and transmittance near the resonances of bright mode (continuum
mode) and dark mode (discrete mode) and explained their optical properties by
the Fano formulism. the Fano formulism of the resonances in the planar
metamaterials can predict the asymmetric shape line and radiative properties
occurring in reflectance and transmittance from the coupling between bright and
dark modes.",1605.00783v1
2016-05-17,Shell-structure of one-particle resonances in deformed potentials,"Shell structure of low-lying neutron resonant levels in axially-symmetric
quadrupole-deformed potentials is discussed, which seems analogous to that of
weakly-bound neutrons. As numerical examples, nuclei slightly outside the
neutron-drip-line, $^{39}_{12}$Mg$_{27}$ and $^{21}_{6}$C$_{15}$, are studied.
For the lowest resonance I obtain $I^{\pi}$ = $\Omega^{\pi}$ = 5/2$^{-}$ for
$^{39}$Mg which is likely to be prolately deformed, while $I^{\pi}$ =
$\Omega^{\pi}$ = 1/2$^{+}$ may be assigned to the nucleus $^{21}$C which may be
oblately deformed. Consequently, $^{21}$C will not be observed as a
recognizable resonant state, in agreement with the experimental information.",1605.05033v1
2016-05-24,Series of broad resonances in atomic three-body systems,"We re-examine the series of resonances found earlier in atomic three-body
systems by solving the Faddeev-Merkuriev integral equations. These resonances
are rather broad and line-up at each threshold with gradually increasing gaps,
the same way for all thresholds and irrespective of the spatial symmetry. We
relate these resonances to the Gailitis mechanism, which is a consequence of
the polarization potential.",1605.07308v1
2016-05-26,Cyclotron resonance of figure-of-eight orbits in a type-II Weyl semimetal,"We study the cyclotron resonance in the electron-hole joint Fermi surface of
a type-II Weyl semimetal. In magnetic field, the electron and hole pockets
touching at the Weyl node are hybridized to form quantized Landau levels
corresponding to semiclassical 8-shaped orbits. We calculate the dynamical
conductivities for the electric fields oscillating in $x$ and $y$-directions
and find that the resonant frequencies in $x$ and $y$ differ by the factor of
two, reflecting to the figure-of-eight electron motion in the real space. The
peculiar anisotropy in the cyclotron resonance serves as a unique
characteristic of the dumbbell-like Fermi surface.",1605.08282v1
2016-05-26,Spin gravitational resonance and graviton detection,"We develop a gravitational analogue of spin magnetic resonance, called spin
gravitational resonance, whereby a gravitational wave interacts with a magnetic
field to produce a spin transition. In particular, an external magnetic field
separates the energy spin states of a spin-1/2 particle, and the presence of
the gravitational wave produces a perturbation in the components of the
magnetic field orthogonal to the gravitational wave propagation. In this
framework we test Dyson's conjecture that individual gravitons cannot be
detected. Although we find no fundamental laws preventing single gravitons
being detected with spin gravitational resonance, we show that it cannot be
used in practice, in support of Dyson's conjecture.",1605.08316v1
2016-05-30,"Comment on ""Exact Classification of Landau-Majorana-Stuckelberg-Zener Resonances by Floquet Determinants""","In a recent Letter [S. Ganeshan, E. Barnes, and S. Das Sarma, Phys. Rev.
Lett. 111, 130405 (2013)], Ganeshan et al. present a general framework to
classify the resonance structure of Landau-Majorana-Stuckelberg-Zener
interferometry into three basic categories distinguished by whether these
resonances correspond to periodic or nonperiodic quantum evolution. In this
Comment, we show that their identification of the real resonances in the regime
of small drive amplitude is incorrect.",1605.09375v1
2016-08-31,Optically Detected Magnetic Resonances of Nitrogen-Vacancy Ensembles in 13C Enriched Diamond,"We present an experimental and theoretical study of the optically detected
magnetic resonance signals for ensembles of negatively charged nitrogen-vacancy
(NV) centers in 13C isotopically enriched single-crystal diamond. We observe
four broad transition peaks with superimposed sharp features at zero magnetic
field and study their dependence on applied magnetic field. A theoretical model
that reproduces all qualitative features of these spectra is developed.
Understanding the magnetic-resonance spectra of NV centers in isotopically
enriched diamond is important for emerging applications in nuclear magnetic
resonance.",1608.08706v1
2016-12-09,Equivalence of the Generalized Zhang-Zhang Polynomial and the Generalized Cube Polynomial,"In this paper we study the resonance graphs of benzenoid systems, tubulenes,
and fullerenes. The resonance graph reflects the interactions between the Kekul
e structures of a molecule. The equivalence of the Zhang-Zhang polynomial
(which counts Clar covers) of the molecular graph and the cube polynomial
(which counts hypercubes) of its resonance graph is known for all three
families of molecular graphs.
  Instead of considering only interactions between 6-cycles (Clar covers), we
also consider 10-cycles, which contribute to the resonance energy of a molecule
as well. Therefore, we generalize the concepts of the Zhang-Zhang polynomial
and the cube polynomial and prove the equality of these two polynomials.",1612.02986v1
2016-12-19,Exclusive Diffractive Resonance Production in Proton-Proton Collisions at the LHC,"A model for exclusive diffractive resonance production in proton-proton
collisions at LHC energies is presented. This model is based on the convolution
of the Donnachie-Landshoff parameterisation of Pomeron flux in the proton with
the Pomeron cross section for resonance production. The hadronic cross section
for f$_{0}$(980) and f$_{2}$(1270) production at midrapidity is given
differentially in mass and transverse momentum of the resonance. The proton
fractional longitudinal momentum loss is presented.",1612.06379v1
2016-12-27,Resonant Wood's anomaly diffraction condition in dielectric and plasmonic grating structures,"The general features of the light scattering resulting in the so-called
resonant Wood's anomalies in the reflection and transmission spectra are
described using the effective parameters of a quasi-guided mode. The expression
determining the spectral angular dependence of Wood's anomaly in the case of
plasmonic grating structures is given and compared to the analogous expression
for dielectric grating structures. Comparison of the resonant Wood's anomalies
(RWA) with the surface plasmon-polariton resonances (SPPRs) is discussed as
well.",1612.08674v1
2017-06-06,Resonant Transmission in One-Dimensional Quantum Mechanics with Two Independent Point Interactions: Full Parameter Analysis,"We discuss the scattering of a quantum particle by two independent successive
point interactions in one dimension. The parameter space for two point
interactions is given by $U(2)\times U(2)$, which is described by eight real
parameters. We perform an analysis of perfect resonant transmission on the
whole parameter space. By investigating the effects of the two point
interactions on the scattering matrix of plane wave, we find the condition
under which perfect resonant transmission occurs. We also provide the physical
interpretation of the resonance condition.",1706.01595v2
2017-06-29,Superconducting Qubit-Resonator-Atom Hybrid System,"We propose a hybrid quantum system, where an $LC$ resonator inductively
interacts with a flux qubit and is capacitively coupled to a Rydberg atom.
Varying the external magnetic flux bias controls the flux-qubit flipping and
the flux qubit-resonator interface. The atomic spectrum is tuned via an
electrostatic field, manipulating the qubit-state transition of atom and the
atom-resonator coupling. Different types of entanglement of superconducting,
photonic, and atomic qubits can be prepared via simply tuning the flux bias and
electrostatic field, leading to the implementation of three-qubit Toffoli logic
gate.",1706.09527v1
2017-07-19,Internal polarization dynamics of vector dissipative-soliton-resonance pulses in normal dispersion fiber lasers,"Investigation of internal polarization dynamics of vector
dissipative-soliton-resonance (DSR) pulses in a mode-locked fiber laser is
presented. Stable vector DSR pulses are experimentally ob- served. Using a
waveplate-analyzer configuration, we find that polarization is not uniform
across a resonant dissipative soliton. Specifically, although the central plane
wave of the resonant dissi- pative soliton acquires nearly a fixed
polarization, the fronts feature polarization states that are different and
spatially varying. This distinct polarizaiton distribution is maintained while
the whole soliton structrue extends with varying gain conditions. Numerical
simulation further confirms the experimental observations.",1707.05939v1
2017-07-24,Resonant photonic crystals based on van der Waals heterostructures,"We propose to use 2D monolayers possessing optical gaps and high exciton
oscillator strength as an element of one-dimensional resonant photonic
crystals. We demonstrate that such systems are promising for the creation of
effective and compact delay units. In the transition-metal-dichalcogenide-based
structures where the frequencies of Bragg and exciton resonances are close, a
propagating short pulse can be slowed down by few picoseconds while the pulse
intensity decreases only 2 - 5 times. This is realized at the frequency of the
""slow"" mode situated within the stopband. The pulse retardation and attenuation
can be controlled by detuning the Bragg frequency from the exciton resonance
frequency.",1707.07604v1
2017-07-27,Chiral symmetry constraints on resonant amplitudes,"We discuss the impact of chiral symmetry constraints on the quark-mass
dependence of meson resonance pole positions, which are encoded in
non-perturbative parametrizations of meson scattering amplitudes.
Model-independent conditions on such parametrizations are derived, which are
shown to guarantee the correct functional form of the leading quark-mass
corrections to the resonance pole positions. Some model amplitudes for $\pi\pi$
scattering, widely used for the determination of $\rho$ and $\sigma$ resonance
properties from results of lattice simulations, are tested explicitly with
respect to these conditions.",1707.08983v2
2017-10-17,Dual frequency parametric excitation of a nonlinear multi degree of freedom amplifier with a digitally modified topology,"Mechanical or electromechanical amplifiers can exploit the high-Q and low
noise features of mechanical resonance, in particular when parametric
excitation is employed. Multi-frequency parametric excitation introduces
tunability and is able to project weak input signals on a selected resonance.
The present paper addresses multi degree of freedom mechanical amplifiers or
resonators whose analysis and features require treatment of the spatial as well
as temporal behavior. In some cases, virtual electronic coupling can alter the
given topology of the resonator to better amplify specific inputs. An
analytical development is followed by a numerical and experimental sensitivity
and performance verifications, illustrating the advantages and disadvantages of
such topologies.",1710.06136v1
2017-10-19,Resonant supercollisions and electron-phonon heat transfer in graphene,"We study effects of strong impurities on the heat transfer in a coupled
electron-phonon system in disordered graphene. A detailed analysis of the
electron-phonon heat exchange assisted by such an impurity through the
'resonant supercollision' mechanism is presented. We further explore the local
modification of heat transfer in a weakly disordered graphene due to a resonant
scatterer and determine spatial profiles of the phonon and electron temperature
around the scatterer under electrical driving. Our results are consistent with
recent experimental findings on imaging resonant dissipation from individual
atomic defects.",1710.07143v1
2018-01-09,An opto-electro-mechanical system based on evanescently-coupled optical microbottle and electromechanical resonator,"Evanescent coupling between a silica optical microbottle resonator and a GaAs
electromechanical resonator is demonstrated. This coupling provides high
optical sensitivity and efficient piezoelectric controllability of mechanical
motion. Opto-electro-mechanical feedback control based on optomechanical
detection and electromechanical control is performed in both heating and
cooling regimes at room temperature. This feedback scheme can be extended to
the efficient control of thermal mechanical motion in electromechanical
resonators with arbitrary structures and materials.",1801.02794v2
2018-01-30,Noise and loss of superconducting aluminium resonators at single photon energies,"The loss and noise mechanisms of superconducting resonators are useful tools
for understanding decoherence in superconducting circuits. While the loss
mechanisms have been heavily studied, noise in superconducting resonators has
only recently been investigated. In particular, there is an absence of
literature on noise in the single photon limit. Here, we measure the loss and
noise of an aluminium on silicon quarter-wavelength ($\lambda/4$) resonator in
the single photon regime.",1801.10204v1
2018-09-02,Asymmetric metasurfaces with high-$Q$ resonances governed by bound states in the continuum,"We reveal that metasurfaces created by seemingly different lattices of
(dielectric or metallic) meta-atoms with broken in-plane symmetry can support
sharp high-$Q$ resonances that originate from the physics of bound states in
the continuum. We prove rigorously a direct link between the bound states in
the continuum and the Fano resonances, and develop a general theory of such
metasurfaces, suggesting the way for smart engineering of resonances for many
applications in nanophotonics and meta-optics.",1809.00330v1
2018-09-14,Four-wave mixing in a silicon microring resonator using a self-pumping geometry,"We report on four-wave mixing in a silicon microring resonator using a
self-pumping scheme instead of an external laser. The ring resonator is
inserted in an external-loop cavity with a fibered semiconductor amplifier as a
source of gain. The silicon microring acts as a filter and we observe lasing in
one of the microring's resonances. We study correlations between signal and
idler generated beams using a Joint Spectral Density experiment.",1809.05323v1
2018-09-18,Charge-Qubit-Resonator-Interface-Based Nonlinear Circuit QED,"We explore applications of nonlinear circuit QED with a charge qubit
inductively coupled to a microwave LC resonator in the photonic engineering and
ultrastrong-coupling multiphoton quantum optics. Simply sweeping the
gate-voltage bias achieves arbitrary Fock-state pulsed maser, where the single
qubit plays the role of artificial gain medium. Resonantly pumping the
parametric qubit-resonator interface leads to the squeezing of resonator field,
which is utilizable to the quantum-limited microwave amplification. Moreover,
upwards and downwards multiphoton quantum jumps may be observed in the steady
state of the driving-free system.",1809.06542v1
2018-09-23,Ferromagnetic resonance in thin ferromagnetic film with surface anisotropy,"The ferromagnetic resonance frequencies are obtained for a thin ferromagnetic
film with surface anisotropy for the cases when the external magnetic field is
applied perpendicularly or parallel to the film surface, and for various
combinations of boundary conditions on the film surface. It is shown that in
the presence of surface anisotropy the ferromagnetic resonance frequency
essentially depends both on the film thickness and on the value of the surface
anisotropy constant. The results obtained provide a basis for the correct
interpretation of experimental data obtained by means of broadband
ferromagnetic resonance in thin film structures.",1809.08644v1
2018-09-24,Strong coupling of ionising transitions,"We demonstrate that a ionising transition can be strongly coupled to a
photonic resonance. The strong coupling manifests itself with the appearance of
a narrow optically active resonance below the ionisation threshold. Such a
resonance is due to electrons transitioning into a novel bound state created by
the collective coupling of the electron gas with the vacuum field of the
photonic resonator. Applying our theory to the case of bound-to-continuum
transitions in microcavity-embedded doped quantum wells, we show how those
strong-coupling features can be exploited as a novel knob to tune both optical
and electronic properties of semiconductor heterostructures.",1809.08876v1
2018-09-27,Identifying resonances with wave-packet dynamics,"A new method for the study of resonant behavior - using wave-packet dynamics
- is presented, based on the powerful window operator technique. The method is
illustrated and quantified by application to the astrophysically-important
example of low-energy $^{12}$C + $^{12}$C collisions. For this selected,
potential model test case, the technique is shown to provide both resonance
energies and widths in agreement with alternative methods, such as
complex-energy scattering-matrix pole searches and scattering phase-shift
analyses. The method has a more general capability to study resonance phenomena
across disciplines, that involve particles temporarily trapped by potential
pockets.",1809.10517v2
2018-10-05,Resonant enhancement of oscillating electric field in atom,"When an atom is placed into an oscillating electric field with frequency far
from atomic resonances, the atomic electrons partly shield this field at the
nucleus. It is conjectured that when the frequency of electric field reaches an
atomic resonance, the electric field at the nucleus may be significantly
enhanced. In this paper, we systematically study the mechanisms of this
enhancement and show that it may reach five orders in magnitude in particular
cases. As an application, we consider laser-assisted neutron capture in
139-Lanthanum nucleus and screening and resonance enhancement of nuclear
electromagnetic transitions by electrons.",1810.02601v1
2018-10-19,Resonant Inductive Coupling as a Potential Means for Wireless Power Transfer to Printed Spiral Coil,"This paper proposes an inductive coupled wireless power transfer system that
analyses the relationship between induced voltage and distance of resonating
inductance in a printed circuit spiral coils. The resonant frequency produced
by the circuit model of the proposed receiving and transmitting coils are
analyzed by simulation and laboratory experiment. The outcome of the two
results is compared to verify the validity of the proposed inductive coupling
system. Experimental measurements are consistent with simulations over a range
of frequencies spanning the resonance.",1810.09436v1
2018-10-25,Exploring magnetic resonance with a compass,"Magnetic resonance plays an important role in today's science, engineering,
and medical diagnostics. Learning and teaching magnetic resonance is
challenging since it requires advanced knowledge of condensed matter physics
and quantum mechanics. Driven by the need to popularize this technologically
impactful phenomenon, we develop an inexpensive table-top demonstration
experiment. It unveils the magnetic resonance of a hand-held compass in the
magnetic fields of a permanent magnet. The setup provides an immediate
visualization of the underlying physical concepts and allows for their
translation to broad student audiences.",1810.11141v1
2019-06-05,Resonance graphs of catacondensed even ring systems,"A catacondensed even ring system (shortly CERS) is a simple bipartite
2-connected outerplanar graph with all vertices of degree 2 or 3. In this
paper, we investigate the resonance graphs (also called $Z$-transformation
graphs) of CERS and firstly show that two even ring chains are resonantly
equivalent iff their resonance graphs are isomorphic. As the main result, we
characterize CERS whose resonance graphs are daisy cubes. In this way, we
greatly generalize the result known for kinky benzenoid graphs. Finally, some
open problems are also presented.",1906.02028v1
2019-06-26,Resonance of bounded isochronous oscillators,"An oscillator is called isochronous if all motions have a common period. When
the system is forced by a time-dependent perturbation with the same period the
phenomenon of resonance may appear. We give a sufficient condition on the
perturbation in order that resonance occurs when the period annulus of the
isochronous oscillator is bounded. In this context, resonance means that all
solutions escape from the period annulus.",1906.11074v2
2019-09-13,Coherent Control of the Non-instantaneous Nonlinear Power-law Response in Resonant Nanostructures,"We experimentally demonstrate coherent control of the nonlinear response of
optical second harmonic generation in resonant nanostructures beyond the
weak-field regime. Contrary to common perception, we show that maximizing the
intensity of the pulse does not yield the strongest nonlinear power-law
response. We show this effect emerges from the temporally asymmetric
photo-induced response in a resonant mediated non-instantaneous interaction. We
develop a novel theoretical approach which captures the photoinduced
nonlinearities in resonant nanostructures beyond the two photon description and
give an intuitive picture to the observed non-instantaneous phenomena.",1909.06126v1
2020-01-19,Fully-charm tetraquarks: $cc\bar{c}\bar{c}$,"In this work, we continue to study the mass spectra of fully-heavy
tetraquarks $cc\bar{c}\bar{c}$ with the quantum numbers of $J^{PC}=0^{++},
1^{+-}, 2^{++}$ in the nonrelativistic chiral quark model. With the help of the
Gaussian Expansion Method, we present dynamical computations for
$cc\bar{c}\bar{c}$ state with considering two structures, meson-meson
[$\bar{c}c$][$\bar{c}c$] and diquark-antidiquark [$cc$][$\bar{c}\bar{c}$] and
their mixing. The results manifest that the energies of the low-lying states
are all higher than the meson-meson thresholds [$\bar{c}c$][$\bar{c}c$].
However, resonances are possible because of the color structure. Several
resonances are proposed and the lowest resonance is predicted to be 6.5 GeV and
the stability of the resonance states is checked using the real scaling method.",2001.06755v1
2020-02-21,Fast in situ observation of atomic Feshbach resonances by photoassociative ionization,"We propose and experimentally investigate a scheme for observing Feshbach
resonances in atomic quantum gases in situ and with a high temporal resolution
of several ten nanoseconds. The method is based on the detection of molecular
ions, which are optically generated from atom pairs at small interatomic
distances. As test system we use a standard rubidium gas (87Rb) with well known
magnetically tunable Feshbach resonances. The fast speed and the high
sensitivity of our detection scheme allows to observe a complete Feshbach
resonance within one millisecond and without destroying the gas.",2002.09384v1
2020-04-02,Interacting Bose gas across a narrow Feshbach resonance,"We use a two-channel model to investigate an interacting Bose gas across a
narrow Feshbach resonance within a field path integral approach. The ground
state properties show strong deviation from that of a broad Feshbach resonance
or a single channel interaction. The deviation can be interpreted by the strong
energy dependence of two-body scattering length near a narrow Feshbach
resonance. As the density increases, the chemical potential and energy per
particle are found to saturate while the inverse compressibility and phonon
velocity undergo a significant reduction. We also take Gaussian fluctuations
into account and calculate the ground state energy correction as well as the
quantum depletion.",2004.00936v2
2020-04-20,Supersymmetric quantum mechanics to study the 16.8 MeV resonance state of $^{9}$B,"The study of a high-lying resonant state of $^{9}$B is carried out using
supersymmetric quantum mechanics (SQM). The resulting isospectral potentials
are very deep and narrow and the generated wave functions identify the
resonance at 16.84 MeV with a width of 69 keV. The present work shows that SQM
can be successfully applied for detection of high-lying resonances in unstable
nuclei.",2004.09105v1
2020-12-04,Universal intensity statistics of multifractal resonance states,"We conjecture that in chaotic quantum systems with escape the intensity
statistics for resonance states universally follows an exponential
distribution. This requires a scaling by the multifractal mean intensity which
depends on the system and the decay rate of the resonance state. We numerically
support the conjecture by studying the phase-space Husimi function and the
position representation of resonance states of the chaotic standard map, the
baker map, and a random matrix model, each with partial escape.",2012.02541v2
2020-12-11,"Universal quantum gates, artificial neurons and pattern recognition simulated by \textit{LC} resonators","We propose to simulate quantum gates by \textit{LC} resonators, where the
amplitude and the phase of the voltage describe the quantum state. By
controlling capacitance or inductance of resonators, it is possible to control
the phase of the voltage arbitrarily. A set of resonators acts as the
phase-shift, the Hadamard and the CNOT gates. They constitute a set of
universal quantum gates. We also discuss an application to an artificial
neuron. As an example, we study a pattern recognition of numbers and alphabets
by evaluating the similarity between an input and the reference pattern. We
also study a colored pattern recognition by using a complex neural network.",2012.06124v1
2020-12-15,Scattering resonances of large weakly open quantum graphs,"In this paper, we consider a sequence of open quantum graphs, with uniformly
bounded data, and we are interested in the asymptotic distribution of their
scattering resonances. Supposing that the number of leads in our quantum graphs
is small compared to the total number of edges, we show that most resonances
are close to the real axis. More precisely, the asymptotic distribution of
resonances of our open quantum graphs is the same as the asymptotic
distribution of the square-root of the eigenvalues of the closed quantum graphs
obtained by removing all the leads.",2012.08369v2
2020-12-23,Electroweak effective theory and beyond Standard Model resonances,"We consider a non-linear realization of the electroweak symmetry-breaking
pattern $SU(2)_L\times SU(2)_R/SU(2)_{L+R}$ to construct a low-energy effective
theory, later extended by the inclusion of heavy new-physics resonances. After
assuming appropriate high-energy constraints given by Weinberg sum-rules and
the asymptotic behaviour of form-factors, we obtain relations between resonance
masses and some low-energy effective couplings. These predictions are compared
with current experimental data and some resonance mass bounds are inferred.",2012.12639v1
2021-01-06,Role of wave-particle resonance in turbulent transport in toroidal plasmas,"Wave-particle interaction in toroidal plasmas is an essential transport
mechanism in drift wave instability-driven microturbulence. In tokamkas,
different wave-particle resonance conditions have been found important for the
energy and particle transport of multiple species in various drift wave
turbulences. To confirm the transport mechanism for electrons and ions in
tokamak drift-wave instabilities, the effect of wave-particle resonance on
turbulent transport is studied using global gyrokinetic particle simulations of
the plasma core ion temperature gradient (ITG) and collisionless trapped
electron mode (CTEM) turbulence. Simulation results show that in CTEM and ITG
turbulence, electron transport is primarily regulated by wave-particle linear
resonance, and the ion transport is regulated by nonlinear wave-particle
decorrelation.",2101.01924v1
2021-01-19,Feasibility of an experimental search for a resonance of a pion and a light nucleus,"A hypothesis is proposed herein, suggesting that a pion-nuclear resonance may
be observed in the $\alpha+d\to{}^6\mathrm{Li}(3.563)+\pi^0$ reaction. The
resonance has a $\pi NN\alpha$ structure, containing $\alpha NN$ and $\pi NN$
subsystems. The former corresponds to the $A=6$ isotriplet
($^6\mathrm{He}_\text{g.s.}$, $^6\mathrm{Li}(3.563)$,
$^6\mathrm{Be}_\text{g.s.}$), whereas the latter is a hypothetical
$NN$-decoupled dibaryon. We propose an experiment to search for this resonance
using the $^7\mathrm{Li}(p,d)$ reaction.",2101.07745v2
2021-01-27,Robust photon-mediated entangling gates between quantum dot spin qubits,"Significant experimental advances in single-electron silicon spin qubits have
opened the possibility of realizing long-range entangling gates mediated by
microwave photons. Recently proposed iSWAP gates, however, require tuning qubit
energies into resonance and have limited fidelity due to charge noise. We
present a novel photon-mediated cross-resonance gate that is consistent with
realistic experimental capabilities and requires no resonant tuning.
Furthermore, we propose gate sequences capable of suppressing errors due to
quasistatic noise for both the cross-resonance and iSWAP gates.",2101.11579v1
2012-05-13,Plasmonic mediated nucleation of resonant nano-cavities in metallic layers,"We predict plasmonic mediated nucleation of pancake shaped resonant
nano-cavities in metallic layers that are penetrable to laser fields. The
underlying physics is that the cavity provides a narrow plasmonic resonance
that maximizes its polarizability in an external field. The resonance yields a
significant energy gain making the formation of such cavities highly favorable.
Possible implications include nano-optics and generation of the dielectric bits
in conductive films that underlie the existing optical recording phase change
technology.",1205.2864v1
2012-05-24,Evolution of overlapping resonances along an isoelectronic sequence,"Near-threshold resonances have been studied for Be-like ions with a focus on
overlapping resonances among Rydberg series converging to different thresholds.
The behavior of the overlapping as a function of Z and the approach to the
limit of infinite Z are investigated. The 4s4p resonance is shown and discussed
in detail as an example.",1205.5481v1
2012-05-24,Resonant Bend Loss in Leakage Channel Fibers,"Leakage channel fibers, designed to suppress higher-order modes, demonstrate
resonant power loss at certain critical radii of curvature. Outside the
resonance, the power recovers to the levels offset by the usual mechanism of
bend-induced loss. Using C$^2$-imaging, we experimentally characterize this
anomaly and identify the corresponding physical mechanism as the radiative
decay of the fundamental mode mediated by the resonant coupling to a cladding
mode.",1205.5584v1
2012-05-31,Variation of Longitudinal Plasma Wavelength under Irradiation and Double Resonance in Coupled Josephson Junctions,"The effect of electromagnetic wave irradiation on the phase dynamics of
intrinsic Josephson junctions in high temperature superconductors is
investigated. We predict three novel effects by variation of the radiation
amplitude and frequency: changing of the longitudinal plasma wavelength at
parametric resonance; double resonance of the Josephson oscillations with
radiation and longitudinal plasma wave; charging of superconducting layers in
the current interval corresponding to the Shapiro step. The ""bump"" structure in
IVC recently observed experimentally is demonstrated. We also observe ragged
Shapiro steps at double resonance.",1205.6923v1
2017-05-03,Spin Resonance and Magnetic Order in an Unconventional Superconductor,"Unconventional superconductivity in many materials is believed to be mediated
by magnetic fluctuations. It is an open question how magnetic order can emerge
from a superconducting condensate and how it competes with the magnetic spin
resonance in unconventional superconductors. Here we study a model d-wave
superconductor that develops spin-density wave order, and find that the spin
resonance is unaffected by the onset of static magnetic order. This result
suggests a scenario, in which the resonance in Nd0.05Ce0.95CoIn5 is a
longitudinal mode with fluctuating moments along the ordered magnetic moments.",1705.01255v2
2017-05-13,Thermal bistability through coupled photonic resonances,"We present a scheme for achieving thermal bistability based on the selective
coupling of three optical resonances. This approach requires one of the
resonant frequencies to be temperature dependent, which can occur in materials
exhibiting strong thermo-optic effects. For illustration, we explore thermal
bistability in two different passive systems, involving either a periodic array
of Si ring resonators or parallel GaAs thin films separated by vacuum and
exchanging heat in the near field. Such a scheme could prove useful for thermal
memory devices operating with transition times $\lesssim$ hundreds of
milliseconds.",1705.04858v1
2017-05-20,Biosensing using Functionally Graded Piezoelectric MEMS Resonators,"Nonlinear dynamics of a two-side electro-statically actuated capacitive
micro-beam is studied. The piezoelectric actuation leads to the generation of
an axial force along the length of the micro-beam and this is used as a tuning
tool to shift the primary resonance of the micro-resonator. The governing
equation of motion is derived by minimization of the Hamiltonian and
generalized to the viscously damped systems. The periodic solutions in the
vicinity of the primary resonance are detected and their stability is
investigated. The basins of attraction conforming to three individual periodic
orbits are determined. The outcomes show that the higher the amplitude of the
periodic orbit, the smaller is the area of the attractor.",1705.08267v1
2017-11-04,Spectral asymmetries in the resonance fluorescence of two-level systems under pulsed excitation,"We present an open-system master equation study of the coherent and
incoherent resonance fluorescence spectrum from a two-level quantum system
under coherent pulsed excitation. Several pronounced features which differ from
the fluorescence under a constant drive are highlighted, including a multi-peak
structure and a pronounced off-resonant spectral asymmetry, in stark contrast
to the conventional symmetrical Mollow triplet. We also study semiconductor
quantum dot systems using a polaron master equation, and show how the key
features of dynamic resonance fluorescence change with
electron--acoustic-phonon coupling.",1711.01502v1
2017-11-27,All-optical wavelength multicasting in quadruple resonance-split coupled Silicon microring cavity,"We demonstrate an all-optical four-channel wavelength multicasting in a
coupled Silicon microring resonator system. The scheme is based on two-photon
absorption induced free carrier dispersion in Silicon. The coupled cavity
facilitates resonance splitting that is utilized as individual channels for
multicasting. Using the split resonances, we achieve an aggregate multicasted
data rate of 48 Gbps (4X12 Gbps). Moreover, we also present a detailed analysis
and performance of the multicasting architecture.",1711.09820v1
2018-03-02,Decoupling of Two Closely Located Dipole Antennas by a Split-Loop Resonator,"In this letter, we theoretically and experimentally prove the possibility of
the complete passive decoupling for two parallel resonant dipoles by a
split-loop resonator. Unlike previously achieved decoupling by a similar
resonant dipole, this decoupling technique allows us to avoid the shrink of the
operation band. Compare to previous work, simulation and measurement show 100\%
enhancemnet of relative operation band from 0.2% to 0.4%",1803.00753v1
2018-03-03,Unified evaluation of surface-enhanced resonance Raman scattering and fluorescence under strong coupling regime,"We demonstrate importance of molecular multiple excitons and higher-order
plasmons for both enhancement and quenching of resonance Raman and fluorescence
of single dye molecule located at plasmonic hotspot under strong coupling
regime. The multiple excitons induce complicated spectral changes in plasmon
resonance and higher-order plasmons yield drastic quenching for both resonant
Raman and fluorescence. A coupled oscillator model composed of plasmon and
multiple excitons reproduces the complicated spectral changes. Purcell factors
derived from higher-order plasmons reproduce the drastic quenching with
considering ultra-fast surface enhanced fluorescence.",1803.01154v1
2018-03-15,Orbital migration and Resonance Offset of the Kepler-25 and K2-24 systems,"Based on the model described in Ramos et al., 2017, we present an
analytical+numerical study of the resonance capture under Type-I migration for
the Kepler-25 (Marcy et al., 2014) and K2-24 (Petigura et al., 2016) Kepler
systems, both close to a 2/1 mean-motion resonance. We find that, depending on
the flare index and the proximity to the central star, the average value of the
period-ratio between two consecutive planets show a significant deviation with
respect to the resonant nominal value, up to values well in agreement with the
observations.",1803.05971v1
2018-03-25,From quantum to classical dipole plasmon resonances in highly-doped nano-crystals,"Dipole plasmon resonances are ubiquitous in nano-particles with delocalized
charge carriers. Doped semi-conductor colloidal nano-crystals constitute a
novel paradigm for plasmon excitations in a finite electron system and offer
the possibility to tune the carrier density and thus the dipole resonance from
visible to infra-red, which cannot be achieved with metallic clusters.
Restricting ourselves to highly n-doped ZnO nano-crystals, we explain the
observed smooth transition from small sizes dominated by quantum effects to
large sizes where the resonance reaches its classical value. A schematic two
interacting highly degenerate level quantum model, validated by a full Random
Phase Approximation calculation, yields nicely the experimentally observed
trends.",1803.09355v1
2018-06-27,Poor-man's model of hollow-core anti-resonant fibers,"We investigate various methods for extending the simple analytical capillary
model to describe the dispersion and loss of anti-resonant hollow-core fibers
without the need of detailed finite-element simulations across the desired
wavelength range. This poor-man's model can with a single fitting parameter
quite accurately mimic dispersion and loss resonances and anti-resonances from
full finite-element simulations. Due to the analytical basis of the model it is
easy to explore variations in core size and cladding wall thickness, and should
therefore provide a valuable tool for numerical simulations of the ultrafast
nonlinear dynamics of gas-filled hollow-core fibers.",1806.10416v2
2018-06-28,Electromagnetic Scattering Resonances of Quasi-1D Nanoribbons,"We analyse the resonance conditions of a long and narrow ribbon of finite
length whether it is conductive or dielectric. This is accomplished by using a
full wave approach based on the material independent modes that naturally
discriminates the role of the geometry and of the material. This method
effectively allows the design of the material in such a way to obtain the
desired resonances. Eventually, as an example, we design two quasi-one
dimensional resonators based on a graphene layer and on a silicon thin film.",1806.11088v3
2018-07-12,Nanomechanical resonators for cryogenic research,"Suspended aluminium nanoelectromechanical resonators have been fabricated,
and the manufacturing process is described in this work. Device motion is
driven and detected with a magnetomotive method. The resonance response has
been measured at 4.2 K temperature in vacuum and low pressure $^4$He gas. At
low oscillation amplitudes the resonance response is linear, producing
Lorentzian line shapes, and Q-values up to 4400 have been achieved. At higher
oscillation amplitudes the devices show nonlinear Duffing-like behavior. The
devices are found to be extremely sensitive to pressure in $^4$He gas. Such
device is a promising tool for studying properties of superfluid helium.",1807.06099v1
2018-07-27,Gaseous Plasmonic Resonators for Metamaterial Applications,"We examine the properties of a gaseous plasma resonator generated by focusing
a high-energy laser pulse through a lens and into a gas. An analytical model is
presented describing the scattering resonance of these near-ellipsoidal plasmas
and its dependence on their eccentricity and intrinsic plasma properties. This
dependence is investigated through Ku band transmission experiments of a
waveguide with an embedded single plasma element and through optical
diagnostics of the laser-induced plasma. The described resonator has the
potential to be used as the building block in a new class of metamaterials with
fully three-dimensional structural flexibility.",1807.10407v1
2018-07-29,Logical Fallacy of using the Electric Field in Non-resonant Near-field Optics,"We find that the electric field is not a suitable physical quantity to
describe the response of a non-metallic material in the study of non-resonant
near-field optics. In practice, we show the spin-less one-electron two-level
system responds differently to longitudinal and transverse electric fields
under the non-resonant condition. This difference originates from the
non-relativistic nature of the system, and should exist in actual many-electron
systems. For this type of system, it is a logical fallacy to use the
constitutive equation in terms of the total electric field and the associated
permittivity. Recognizing this fallacy, both experimental and theoretical
progress is needed in the field of non-resonant near-field optics of
non-metallic materials.",1807.10991v1
2018-08-02,Enhanced Attenuation Arising from Lattice Resonances in a Plasma Photonic Crystal,"We describe the experimental verification of lattice resonances in
two-dimensional photonic crystals constructed from an array of gaseous plasma
columns. Enhancements are seen in the extinction of normal incidence transverse
electric electromagnetic waves when the localized surface plasmon modes of the
plasma columns are shifted into the vicinity of the photonic crystal Bragg
resonances. Simulations and experiments are in reasonable agreement and confirm
the appearance of a Fano-like profile with deep and broad extinction bands. The
broadening of the spectra as surface plasmon modes come into coincidence with
Bragg gaps suggest that the Bragg fields couple strongly into the radiating Mie
dipoles to drive enhanced damping of the photonic crystal resonance.",1808.00610v1
2018-12-11,Limit cycles and bifurcations in a nonlinear MEMS oscillator with a 1:3 internal resonance. Part I: The case of a driven resonator,"This work investigates the behavior of an AlGaAs/GaAs piezoelectric nonlinear
MEMS oscillator exhibiting a 1:3 internal resonance. The device is explored in
an open-loop configuration, i.e. as a driven resonator, where depending on the
drive conditions we observe energy transfer between the first and third modes,
and the emergence of supercritical Hopf limit cycles. We examine the dependence
of these bifurcations on the oscillator's frequency and amplitude, and
reproduce the observed behavior using a system of nonlinearly coupled equations
which show interesting scaling behavior.",1812.04188v1
2019-01-24,A Quantum Model of Feshbach Resonances,"We consider a quantum model of two-channel scattering to describe the
mechanism of a Feshbach resonance. We perform a rigorous analysis in order to
count and localize the energy resonances in the perturbative regime, i.e., for
small inter-channel coupling, and in the non-perturbative one. We provide an
expansion of the effective scattering length near the resonances, via a
detailed study of an effective Lippmann-Schwinger equation with
energy-dependent potential.",1901.08282v1
2019-01-24,Resonantly Equivalent Catacondensed Even Ring Systems,"In this paper we generalize the binary coding procedure of perfect matchings
from catacondensed benzenoid graphs to catacondensed even ring systems (also
called cers). Next, we study cers with isomorphic resonance graphs. For this
purpose, we define resonantly equivalent cers. Finally, we investigate cers
whose resonance graphs are isomorphic to the resonance graphs of catacondensed
benzenoid graphs. As a consequence we show that for each phenylene there exists
a catacondensed benzenoid graph such that their resonance graphs are
isomorphic.",1901.08354v1
2019-02-27,Ab initio calculations of 5H resonant states,"By solving the 5-body Faddeev-Yakubovsky equations in configuration space
with realistic nuclear Hamiltonians we have studied the resonant states of
$^5$H isotope. Two different methods, allowing to bypass the exponentially
diverging boundary conditions, have been employed providing consistent results.
The existence of $^5$H broad J$^{\pi}$=1/2$^+$,3/2$^+$,5/2$^+$ states as
S-matrix poles has been confirmed and compared with the, also calculated,
resonant states in $^4$H isotope. We have established that the positions of
these resonances only mildly depend on the nuclear interaction model.",1902.10553v1
2019-02-28,Reflected wavefront manipulation by acoustic metasurface with anisotropic local resonant units,"In this work, we develop the gradient metasurface is constructed of a locally
anisotropic resonant structure, comprising a steel cylinder with an elliptical
rubber coating embedded in epoxy. The deflective angles of rubber ellipses in
the locally anisotropic resonant unit provide a method of controlling the
reflected phase. Phase shifts of the reflected wave can cover the 2pi range.
With an appropriate design of the phase profiles along the acoustic
metasurface, we can achieve anomalous reflection and Bessel beam. The locally
anisotropic resonant units have significant potential for engineering and
manipulating acoustic wavefronts",1902.10862v1
2019-03-17,Sensing Kondo correlations in a suspended carbon nanotube mechanical resonator with spin-orbit coupling,"We study electron mechanical coupling in a suspended carbon nanotube (CNT)
quantum dot device. Electron spin couples to the flexural vibration mode due to
spin-orbit coupling in the electron tunneling processes. In the weak coupling
limit, i.e. electron-vibration coupling is much smaller than the electron
energy scale, the damping and resonant frequency shift of the CNT resonator can
be obtained by calculating the dynamical spin susceptibility. We find that
strong spin-flip scattering processes in Kondo regime significantly affect the
mechanical motion of the carbon nanotube: Kondo effect induces strong damping
and frequency shift of the CNT resonator.",1903.07049v1
2019-08-30,$\bf ^{12}{C} + {}^{16}{O}$ molecular resonances at deep sub-barrier energy,"The existence of $^{12}{\rm C} + {}^{16}{\rm O}$ molecular resonances at
sub-barrier energy has been a significant problem in nuclear astrophysics
because they strongly affect the $^{12}{\rm C} + {}^{16}{\rm O}$ fusion
reaction rate in type Ia supernovae and heavy stars. However, experimental
surveys have been limited to 4~MeV and cannot access the deep sub-barrier
energy due to a very small fusion cross section. Here we predict a couple of
resonances with $J^\pi=0^+$, $2^+$, and $4^+$ in the deep sub-barrier energy
based on the antisymmetrized molecular dynamics calculation that reproduces the
known resonances and low-lying spectrum of $^{28}{\rm Si}$.",1908.11638v1
2019-11-22,Suppressed Charge Dispersion via Resonant Tunneling in a Single-Channel Transmon,"We demonstrate strong suppression of charge dispersion in a
semiconductor-based transmon qubit across Josephson resonances associated with
a quantum dot in the junction. On resonance, dispersion is drastically reduced
compared to conventional transmons with corresponding Josephson and charging
energies. We develop a model of qubit dispersion for a single-channel
resonance, which is in quantitative agreement with experimental data.",1911.10011v2
2019-11-29,The enigmatic $Δ(1600)$ resonance,"Our recently proposed model of the $\Delta(1600)$ resonance, in which the
dominant component is a quasi-bound state of the $\Delta(1232)$ and the pion,
is confronted with a similar model of the $N^*(1440)$ resonance as its
counterpart in the P11 partial wave. We stress an essentially different
mechanism responsible for generating the two resonances.",1911.13026v1
2019-12-04,Applications of resonance theory without analyticity assumption,"We prove that the results in scattering theory that involve resonances are
still valid for non-analytic potentials, even if the notion of resonance is not
defined in this setting. More precisely, we show that if the potential of a
semiclassical Schr\""odinger operator is supposed to be smooth and to decrease
at infinity, the usual formulas relating scattering quantities and resonances
still hold. The main ingredient for the proofs is a resolvent estimate of a new
type, relating the resolvent of an operator with the resolvent of its cut-off
counterpart.",1912.02091v1
2019-12-04,Explicit form of the effective evolution equation for the randomly forced Schrödinger equation with quadratic nonlinearity,"An effective equation describes a weakly nonlinear wave field evolution
governed by nonlinear dispersive PDEs \emph{via} the set of its resonances in
an arbitrary big but finite domain in the Fourier space. We consider the
Schr\""{o}dinger equation with quadratic nonlinearity including small external
random forcing/dissipation.
  An effective equation is deduced explicitly for each case of monomial
quadratic nonlinearities $ u^2, \, \bar{u}u, \, \bar{u}^2$ and the sets of
resonance clusters are studied. In particular, we demonstrate that the
nonlinearity $\bar{u}^2$ generates no 3-wave resonances and its effective
equation is degenerate while in two other cases the sets of resonances are not
empty. Possible implications for wave turbulence theory are briefly discussed.",1912.02289v1
2020-03-02,Resonant capture in quadruple stellar systems,"Some quadruple star systems in the hierarchical 2+2 configuration exhibit
orbit-orbit resonances between the two compact binaries. We show that the most
important resonances occur at period ratios of 1:1, 3:2 and 2:1. We describe
the conditions required for capture and show that they can be satisfied at the
3:2 and 2:1 resonances in binaries that migrate significantly in semimajor axis
after circularization, probably through magnetic braking or gravitational
radiation.",2003.01141v2
2020-03-11,"Investigation of contributions of the $2_2^+$ resonance in $^6$He via analysis of $^6$He($p$, $p'$)","We investigate the contribution of the $2^{+}_{2}$ resonance in $^6$He to
observables via analysis of the $^6$He($p,p'$) reaction by using the
continuum-discretized coupled channels method combined with the complex-scaling
method. In this study, we obtain the $2^{+}_{2}$ state with the resonant energy
2.25 MeV and the decay width 3.75 MeV and analyse contributions of resonances
and nonresonant continuum states to the cross section separately. It is found
that the $2^{+}_{2}$ state plays an important role in the energy spectrum.
Furthermore, contributions of nonresonant continuum states are also important
to clarify the properties of the $2^{+}_{2}$ state.",2003.05123v2
2020-05-30,Configurational entropy and spectroscopy of pomeron resonances in dynamical AdS/QCD,"Pomeron resonances in AdS/QCD are here studied using the configurational
entropy (CE). The concept of CE Regge trajectories, associating the CE of the
pomeron resonances with both their spin $J^{PC}$ and to their mass spectra, is
used to derive the mass spectra of higher $J^{PC}$ pomeron resonances. For it,
the linear, the exponential modified and the anomalous quadratic dilatonic
models, each one with linear and logarithmic anomalous corrections, are
employed. Several methods are implemented, hybridizing AdS/QCD and established
data of lattice QCD.",2006.00332v2
2020-10-04,A novel theoretical approach for the study of resonances in weakly bound systems,"In this paper, a novel theoretical scheme is presented to investigate
resonant levels in weakly bound nuclear systems by the use of isospectral
potentials. In this scheme, a new potential is constructed which is strictly
isospectral with the original shallow-well potential and has properties that
are desirable to calculate resonances more accurately and easier. Effectiveness
of the method has been had been demonstrated in terms of its application to the
first $0^+$ resonances in the neutron-rich isotopes $^A$C ($\equiv
^{A-2}$C+n+n) in the three-body cluster model for A=18, 20.",2010.01585v1
2020-10-05,Deterministic force-free resonant activation,"Combined action of noise and deterministic force in dynamical systems can
induce resonant effects. Here, we demonstrate a minimal,
deterministic-force-free, setup allowing for occurrence of resonant, noise
induced effects. We show that in the archetypal problem of escape from finite
intervals driven by $\alpha$-stale noise with the periodically modulated
stability index, depending on the initial direction of the modulation,
resonant-activation-like or noise-enhanced-stability-like phenomena can be
observed.",2010.02120v2
2020-11-06,Characterization of photon pairs generated by a silicon ring resonator under electrical self-pumping,"We report on the generation of nonclassical states of light in a silicon ring
resonator in a selfpumping scheme. The ring is inserted in a lasing cavity, for
which it acts as a filter, so that the lasing always occurs within a selected
ring resonance, without active stabilization of the resonance frequency. We
show the emission of coincident photon pairs and study their correlation
properties through the reconstruction of the measurements via stimulated
emission.",2011.03273v1
2020-11-11,Acoustic scattering and field enhancement through a single aperture,"We study the acoustic field enhancement through a circular hole in a hard
plate of finite thickness in this work. We derive the boundary-integral
equations corresponding to the acoustic scattering to investigate the
Fabry-Perot type resonant frequencies that induce the field enhancement. The
asymptotic expansions of Fabry-Perot type resonances with respect to the size
of the hole are derived, and the quantitative analysis of the field enhancement
caused by the configuration at the resonant frequencies is presented with both
the enhancement order and the shapes of resonant modes characterized. The
transmission in the nonresonant quasi-static regime is also investigated.",2011.05887v2
2020-11-29,Resonances of the Laplace operator on homogeneous vector bundles on symmetric spaces of real rank-one,"We study the resonances of the Laplacian acting on the compactly supported
sections of a homogeneous vector bundle over a Riemannian symmetric space of
the non-compact type. The symmetric space is assumed to have rank-one but the
irreducible representation $\tau$ of $K$ defining the vector bundle is
arbitrary. We determine the resonances. Under the additional assumption that
$\tau$ occurs in the spherical principal series, we determine the resonance
representations. They are all irreducible. We find their Langlands parameters,
their wave front sets and determine which of them are unitarizable.",2011.14355v1
2021-02-16,Possible dimensionality transition behavior in localized plasmon resonances of confinement-controlled graphene devices,"We investigated the dimensionality transition behavior of graphene localized
plasmon resonances in confinement-controlled graphene devices. We first
demonstrated a possibility of dimensionality transition, based on the devices
carrier-density dependence, from a two-dimensional plasmon resonance to a
one-dimensional plasmon one. We fabricated optical transparent devices and
electrical transport devices on the same optical transparent wafer. These
devices allow detailed control and analysis between carrier density and plasmon
resonance peak positions. The carrier density from square root n
(two-dimensional) to constant (one-dimensional) is consistent with the
theoretical predictions based on the Dirac Fermion carriers in linear-band
structure materials.",2102.08115v1
2021-03-15,Ferromagnetic Resonance in Permalloy Metasurfaces,"Permalloy films with one-dimensional (1D) profile modulation of submicron
periodicity are fabricated based on commercially available DVD-R discs and
studied using ferromagnetic resonance (FMR) method and micromagnetic numerical
simulations. The main resonance position shows in-plane angular dependence
which is strongly reminiscent of that in ferromagnetic films with uniaxial
magnetic anisotropy. The main signal and additional low field lines are
attributed to multiple standing spin wave resonances defined by the grating
period. The results may present interest in magnetic metamaterials and
magnonics applications.",2103.08704v1
2021-04-01,Dichotomous flow with thermal diffusion and stochastic resetting,"We consider properties of one-dimensional diffusive dichotomous flow and
discuss effects of resonant activation in the presence of statistically
independent random resetting mechanism. Resonant activation and stochastic
resetting are two similar effects, as both of them can optimize the noise
induced escape. Our studies show completely different origins of optimization
in adapted setups. Efficiency of stochastic resetting relies on elimination of
suboptimal trajectories while resonant activation is associated with matching
of time scales in the dynamic environment. Consequently, both effects can be
easily tracked by studying their asymptotic properties. Finally, stochastic
resetting cannot be easily used to further optimization of the resonant
activation in symmetric setups.",2104.00455v2
2021-05-05,Few-photon optical diode in a chiral waveguide,"We study the coherent transport of one or two photons in a 1D waveguide
chirally coupled to a nonlinear resonator. Analytic solutions of the one-photon
and two-photon scattering is derived. Although the resonator acts as a
non-reciprocal phase shifter, light transmission is reciprocal at one-photon
level. However, the forward and reverse transmitted probabilities for two
photons incident from either the left side or the right side of the nonlinear
resonator are nonreciprocal due to the energy redistribution of the two-photon
bound state. Hence, the nonlinear resonator acts as an optical diode at
two-photon level.",2105.02059v2
2021-06-08,$\mathbf{{}^{12}{C} + {}^{12}{C}}$ Fusion $\boldsymbol{S^*}$-factor from a Full-microscopic Nuclear Model,"The ${}^{12}\mathrm{C} + {}^{12}\mathrm{C}$ fusion reaction plays a vital
role in the explosive phenomena of the universe. The resonances in the Gamow
window rule its reaction rate and products. Hence, the determination of the
resonance parameters by nuclear models is indispensable as the direct
measurement is not feasible. Here, for the first time, we report the resonances
in the ${}^{12}\mathrm{C} + {}^{12}\mathrm{C}$ fusion reaction described by a
full-microscopic nuclear model. The model plausibly reproduces the measured
low-energy astrophysical $S$-factors and predicts the resonances in the Gamow
window. Contradictory to the hindrance model, we conclude that there is no
low-energy suppression of the $S$-factor.",2106.04321v1
2021-07-29,Exceptional points in dielectric spheroid,"Evolution of resonant frequencies and resonant modes as dependent on the
aspect ratio is considered in a dielectric high index spheroid. Because of
rotational symmetry of the spheroid the solutions are separated by the
azimuthal index $m$. By the two-fold variation of a refractive index and the
aspect ratio we achieve exceptional points (EPs) at which the resonant
frequencies and resonant modes are coalesced in the sectors $m=0$ for both TE
and TM polarizations and $m=1$.",2107.13719v1
2021-07-31,Fano resonance from a one-dimensional topological photonic crystal,"An ultra-compact one-dimensional topological photonic crystal (1D-TPC) is
designed in a single mode silicon bus-waveguide to generate Fano resonance
lineshape. The Fano resonance comes from the interference between the discrete
topological boundary state of the 1D-TPC and the continuum high-order leaky
mode of the bus-waveguide. Standalone asymmetric Fano resonance lineshapes are
obtained experimentally in the waveguide transmission spectrum with a maximum
extinction ratio of 33 dB and a slope ratio of 10 dB/nm over a broadband flat
background.",2108.00181v1
2021-08-09,Effective and efficient resonant transitions in periodically modulated quantum systems,"We analyse periodically modulated quantum systems with $SU(2)$ and $SU(1,1)$
symmetries. Transforming the Hamiltonian into the Floquet representation we
apply the Lie transformation method, which allows us to classify all effective
resonant transitions emerging in time-dependent systems. In the case of a
single periodically perturbed system, we propose an explicit iterative
procedure for the determination of the effective interaction constants
corresponding to every resonance both for weak and strong modulation. For
coupled quantum systems we determine the efficient resonant transitions
appearing as a result of time modulation and intrinsic non-linearities.",2108.04360v1
2021-08-10,Fitting ultracold resonances without a fit,"We present a numerical procedure allowing one to extract Feshbach resonance
parameters from numerical calculations without relying on approximate fitting
procedures. Our approach is based on a simple decomposition of the reactance
matrix in terms of poles and residual background contribution, and can be
applied to the general situation of inelastic overlapping resonances. A simple
lineshape for overlapping inelastic resonances, equivalent to known results in
the particular cases of isolated and overlapping elastic features, is also
rigorously derived.",2108.04712v1
2021-08-31,Effect of light intensity on resonance patterns in CDIMA reaction,"Photosensitive CDIMA reaction-diffusion equation is considered to explain the
resonance in the linearly coupled system. The conditions for Turing instability
is obtained for the coupled reaction-diffusion system. Also, determining the
critical diffusion coefficients for exiting the resonance type pattern is also
discussed with analytical conditions. The photosensitive effect on $3:1$
resonance forcing is studied in the presence of strong and weak couplings.
Numerical simulations are performed to validate the theoretical findings.",2108.13731v1
2021-09-10,Numerical Simulation of the Coupling between Split-Ring Resonators and Antiferromagnetic Magnons,"We report on the results of simulations of the terahertz response of a split
ring resonator (SRR) metamaterial coupled to a hypothetical antiferromagnetic
material characterized by a magnon resonance. The simulations were done using
finite difference time domain (FDTD) techniques. By adjusting the magnon
frequency we find a hybridization of the resonant normal modes of the SRR and
the magnon manifested as an avoided crossing. By varying the physical
separation between the metamaterial and the antiferromagnet with a dielectric
spacer, we evaluated the coupling strength between the two.",2109.05086v1
2021-09-29,$N_C$ evolution of the light meson resonances,"The variation of the resonance poles, i.e., the mass and width, originating
from changing the values of $N_C$, the number of the QCD colors, provide an
intuitive theoretical method to discriminate the interior constituents of
hadrons. Many different approaches, including unitarized chiral amplitudes,
dispersive methods, quark models, linear-sigma-model-like framework, etc., have
been widely used to determine the $N_C$ trajectories of the various resonance
pole positions. We focus on the discussions of the light-flavor meson
resonances in this work.",2109.14240v1
2021-11-10,Limit possible electric field in plasmon nanogap resonator,"We propose the theory of the plasmon excited in ultra-narrow plasmonic gap
formed by a metal cylinder on a metal surface, that generates a huge resonant
local electromagnetic field in optical frequencies. Resonance conditions are
found. The maximum possible enhancement of the electric field in the nanogap is
estimated as $\left|E_{max} \right|/ \left| E_{0} \right| \propto \left|
\varepsilon_m \right|^{3} \varepsilon_{d}^{-1} \left( \Im
\varepsilon_{m}\right) ^{-2}$ A simple ultranarrow-gaped resonator can be used
for SERS sensing and infrared spectroscopy of adsorbed molecules. We assume
that a plasmonic nanogap is simplest and most straightforward way to increase
flexibility as well as sensitivity of the plasmon-enhanced spectroscopes.",2111.05511v1
2022-03-07,Nanophotonic resonance modes with the nanobem toolbox,"Nanobem is a Matlab toolbox for the solution of Maxwell's equations for
nanophotonic systems and the computation of resonance modes, sometimes also
referred to as quasinormal modes or resonance states. It is based on a Galerkin
scheme for the boundary element method, using Raviart-Thomas shape elements for
the representation of the tangential electromagnetic fields at the particle
boundary. The toolbox is written in an object-oriented manner with the focus on
clarity rather than speed, and has been developed and tested for small to
intermediate problems with a few thousand boundary elements. The computation of
the resonance modes uses the contour integral method of Beyn.",2203.03283v1
2022-04-19,4-Dimensional Symmetry Breaking of Light in Kerr Ring Resonators,"Symmetry breaking of light states is of interest for the understanding of
nonlinear optics, photonic circuits, telecom applications and optical pulse
generation. Here we demonstrate 4-fold symmetry breaking of the resonances of
ring resonators with Kerr nonlinearity. This symmetry breaking naturally occurs
in a resonator with bidirectionally propagating light with orthogonal
polarization components. The four circulating field components are shown to
exhibit multiple and, nested and isolated, spontaneous symmetry breaking
bifurcations, and are also capable of complex oscillatory dynamics - such as
four-field self-switching, and unusual temporal cavity soliton-like dynamics on
time scales of multiple round-trip times, with extended delays between
subsequent generations.",2204.08837v1
2022-04-20,Spectral Analysis of Scattering Resonances with Application on High Contrast Nanospheres,"In this paper we provide further spectral analysis of the general asymptotic
scattering resonances formula of small high contrast 3D dielectrics of
arbitrary shape, initially derived to a first order approximation. To
investigate the components of a full expansion of such resonances, a breakdown
is presented for the case of high contrast nanospheres. We also derive, for
radially symmetric fields, an exact resonance formula for a spherical scatterer
in terms of its radius, not necessarily small, and dielectric susceptibility
coefficient, not necessarily high. Formula that is useful in imaging
applications to identify objects' properties from frequency measurements. The
latter formula is further developed and simplified in the case of high contrast
nanospheres.",2204.09733v1
2022-05-16,Power and Skew Reduction Using Resonant Energy Recycling in 14-nm FinFET Clocks,"As the demand for high-performance microprocessors increases, the circuit
complexity and the rate of data transfer increases resulting in higher power
consumption. We propose a clocking architecture that uses a series LC resonance
and inductor matching technique to address this bottleneck. By employing pulsed
resonance, the switching power dissipated is recycled back. The inductor
matching technique aids in reducing the skew, increasing the robustness of the
clock network. This new resonant architecture saves over 43% power and 91% skew
clocking a range of 1--5 GHz, compared to a conventional primary-secondary
flip-flop-based CMOS architecture.",2205.07949v1
2022-05-17,Signature of resonant modes in radiative heat current noise spectrum,"Radiative heat transfer between bodies is often dominated by a narrow
resonance in the transmission, e.~g. due to a cavity mode or a surface
excitation. However, this resonant character is not visible in the average heat
current. Here, we show that the noise spectrum of heat current can serve as a
direct probe of the heat-carrying excitations. Namely, the resonant mode
produces a sharp peak in the noise spectrum with a width related to the mode
lifetime. We demonstrate that heat transfer in realistic superconducting
circuits or between two-dimensional metals can realize our predictions.",2205.08558v1
2022-06-25,High cooperativity coupling of rare earth spins with planar superconducting resonator,"Interfacing superconducting microwave resonator with rare earth doped
crystals presents a promising hybrid quantum system for applications including
spin-assisted transducers and memories. The coupling strength between spins of
rare earth ions and the microwave photons is characterized by the
cooperativity. Here we report an ultra-high cooperativity $C \sim$ 650 between
rare earth spins and a planar superconducting microwave resonator that features
a highly uniform magnetic field for harnessing the strong anisotropic coupling
strength of erbium doped yttrium orthosilicate. This cooperativity rivals that
from a bulk dielectric resonator and paves a path for efficiently coupling of
spins with microwave photons on an integrated platform.",2206.12646v1
2022-06-26,Leray-Schauder degree for the resonant Q-curvature problem in even dimensions,"In this paper, using the theory of critical points at infinity of Bahri, we
derive an exact bubbling rate formula for the resonant prescribed Q-curvature
equation on closed even-dimensional Riemannian manifolds. Using this, we derive
new existence results for the resonant prescribed Q-curvature problem under a
positive mass type assumption. Moreover, we derive a compactness theorem for
conformal metrics with prescribed Q-curvature under a non-degeneracy
assumption. Furthermore, combining the bubbling rate formula with the
construction of some blowing-up solutions, we compute the Leray-Schauder degree
of the resonant prescribed Q-curvature equation under a non-degeneracy and
Morse type assumption.",2206.12964v1
2022-09-12,Ultra-High Q Nanomechanical Resonators for Force Sensing,"Nanomechanical resonators with ultra-high quality factors have become a
central element in fundamental research, enabling measurements below the
standard quantum limit and the preparation of long-lived quantum states. Here,
I propose that such resonators will allow the detection of electron and nuclear
spins with high spatial resolution, paving the way to future nanoscale magnetic
resonance imaging instruments. The article lists the challenges that must be
overcome before this vision can become reality, and indicates potential
solutions.",2209.05183v1
2022-09-27,Λ(1520) resonance production with respect to transverse spherocity using EPOS3+UrQMD,"Resonances are sensitive to the properties of the medium created in heavy ion
collision. They also provide insight into the properties of the hadronic phase.
Studying the dependence of the yield of resonances on transverse spherocity and
multiplicity allows us to understand the resonance production mechanism with
event topology and system size, respectively. The results reported pertains to
{\Lambda}(1520) . The data from EPOS3 is used for the present analysis.",2209.14056v2
2022-11-15,Emergence of a stochastic resonance in machine learning,"Can noise be beneficial to machine-learning prediction of chaotic systems?
Utilizing reservoir computers as a paradigm, we find that injecting noise to
the training data can induce a stochastic resonance with significant benefits
to both short-term prediction of the state variables and long-term prediction
of the attractor of the system. A key to inducing the stochastic resonance is
to include the amplitude of the noise in the set of hyperparameters for
optimization. By so doing, the prediction accuracy, stability and horizon can
be dramatically improved. The stochastic resonance phenomenon is demonstrated
using two prototypical high-dimensional chaotic systems.",2211.09955v1
2022-11-22,Time-reversibility and integrability of p:-q resonant vector fields,"We study local analytical integrability in a neighborhood of $p:-q$ resonant
singular point of a two-dimensional vector field and its connection to
time-reversibility with respect to the non-smooth involution $
\varphi(x,y)=(y^{p/q},x^{q/p}). $ Some generalizations of the theory developed
by K.~S.~Sibirsky for $1:-1$ resonant case to the $p:-q$ resonant case are
presented.",2211.12411v2
2022-12-08,Electroelastic metasurface with resonant piezoelectric shunts for tunable wavefront control,"This study presents a tunable phase-modulated metasurface composed of
periodically distributed piezoelectric patches with resonant-type shunt
circuits. The fully coupled electromechanical model is established to study the
transmission characteristics of the metasurface unit and validated through
numerical and experimental studies. Based on the analysis of the metasurface
unit, we first explore the performance of electroelastic metasurface with
single-resonant shunts and then extend its capability with multi-resonant
shunts. By only tuning the electric loads in the shunt circuits, we utilize the
proposed metasurface to accomplish wave deflection and wave focusing of A0 mode
Lamb waves at different angles and focal points, respectively.",2212.04057v1
2022-12-08,Analytic normal forms for planar resonant saddle vector fields,"We give essentially unique ``normal forms'' for germs of a holomorphic vector
field of the complex plane in the neighborhood of an isolated singularity which
is a p:q resonant-saddle. Hence each vector field of that type is conjugate, by
a germ of a biholomorphic map at the singularity, to a preferred element of an
explicit family of vector fields. These model vector fields are polynomial in
the resonant monomial.Abstract. This work is a followup of a similar result
obtained for parabolic diffeomorphisms which are tangent to the identity, and
solves the long standing problem of finding explicit local analytic models for
resonant saddle vector fields.",2212.04300v1
2022-12-14,Non-adiabatic Level Crossing in Resonant Neutrino Oscillations,"Analytic results are presented for the probability of detecting an electron
neutrino after passage through a resonant oscillation region. If the electron
neutrino is produced far above the resonance density, this probability is
simply given by $\langle \,P_{\nu_e} \, \rangle \approx \sin^2 \theta_0+
P_\text{x} \cos 2 \theta_0$, where $\theta_0$ is the vacuum mixing angle. The
probability is averaged over the production as well as the detection positions
of the neutrino and $P_\text{x} $ is the Landau-Zener transition probability
between adiabatic states. Finally, this result is applied to resonance
oscillations within the solar interior.",2212.06978v1
2022-12-21,Resonance expansion of quadratic quantities with regularized quasinormal modes,"Resonance expansions are an intuitive approach to capture the interaction of
an optical resonator with light. Here, we present a quasinormal mode expansion
approach for quadratic observables exploiting the rigorous Riesz projection
method. We demonstrate the approach by a numerical implementation of a
state-of-the-art quantum light source and emphasize the ability of the approach
to provide modal expansions outside the underlying nanophotonic resonator.",2212.11117v1
2023-05-03,Exceptional points in single open acoustic resonator due to the symmetry breaking,"Exceptional points (EPs) have been widely studied in quantum mechanics,
condensed matter physics, optics and photonics. However, their potential in
acoustics has only recently been recognized due to the rapid development of
acoustic metamaterials. This paper proposes a method for achieving EP
conditions in acoustic resonators by lowering their symmetry and enabling
resonant mode interaction. The formation of EPs is predicted through direct
numerical simulation supported by coupled mode theory and resonant state
expansion. These findings have significant implications for the design and
optimization of acoustic metamaterials for applications such as acoustic
sensing and noise reduction.",2305.02370v1
2023-05-26,"Practical Concepts for Design, Construction and Application of Halbach Magnets in Magnetic Resonance","This review is a compilation of relevant concepts in designing Halbach
multipoles for magnetic resonance applications. The main focus is on providing
practical guidelines to plan, design and build such magnets. Therefore,
analytical equations are presented for estimating the magnetic field from ideal
to realistic systems. Various strategies of homogenizing magnetic fields are
discussed together with concepts of opening such magnets without force, or
combining them for variable fields. Temperature compensation and other
practical aspects are also reviewed. For magnetic resonance two polarities (di-
and quadrupole) are of main interest, but higher polarities are also included.",2305.17227v2
2023-06-14,"Optical ""fingerprints"" of dielectric resonators","The complete picture of the optical properties of resonant structures, along
with the frequency, quality factor, and line shape in the scattering spectra,
is determined by the electromagnetic field distribution patterns, which are a
kind of ""fingerprint"" of each resonant eigenmode. In this paper, we
simultaneously analyze the changes in the spectra and the transformation of the
field pattern during the topological transitions from a thin disk to a ring
with a gradually increasing thickness and further to a split ring. In addition,
we demonstrate characteristic optical fingerprints for well-known interference
effects such as bound states in the continuum and Fano resonances.",2306.08361v1
2023-07-11,Multimode resonance transition to collapsed snaking in normal dispersion Kerr resonators: Bright versus dark solitons,"We study the dynamics of Kerr cavity solitons in the normal dispersion
regime, in the presence of an intracavity phase modulation. The associated
parabolic potential introduces multimode resonances, which promote the
formation of high-order bright solitons. By gradually reducing the potential
strength, bright solitons undergo a transition into dark solitons. We describe
this process as a shift from a multimode resonance to a collapsed snaking
bifurcation structure. This work offers a comprehensive overview of cavity
dynamics and may provide a potential pathway to access multi-stable states by
effectively varying the phase modulation.",2307.05027v1
2023-07-12,A series of avoided crossings of resonances in the system of several different dielectric resonators results in giant Q-factors,"We perform optimization of Q-factor in the system of freestanding
three/four/five/six coaxial subwavelength dielectric disks over all scales.
Each parameter contributes almost one order of magnitude of the Q-factor due to
multiple avoided crossings of resonances to give totally the unprecedented
values for the Q-factors: $6.6\cdot10^4$ for the three, $4.8\cdot10^6$ for
four, $8.5\cdot10^7$ for five and one billion for six freestanding silicon
disks. By multipole analysis of the resulting hybridized resonant mode we
observe that such extremely large values of the $Q$-factor are attributed to
strong redistribution of radiation that originates from almost exact
destructive interference of dominating complex multipole radiation amplitudes.",2307.05937v1
2023-08-17,Nonreciprocal photon transport in indirectly coupled whispering-gallery mode resonators,"We study the reflection and transmission properties of a system comprising
two whispering-gallery mode resonators, each containing a Zeeman-split quantum
dot and side-coupled to an optical fiber. Our results demonstrate that
unidirectional reflection and transmission can be achieved by tuning the
coupling strength between the resonators and the optical fiber. Furthermore, we
establish a correspondence between quantum dot energy level resonance
frequencies and the positions of low reflection (transmission) peaks at a phase
shift of {\pi}. This research provides insights for the development of quantum
optical devices like isolators, circulators, and routers.",2308.08750v1
2023-09-18,Investigations of Helmholtz Resonators with Curved Tapered Embedded Neck Extension,"In this study, the performance of Helmholtz resonators with curved tapered
neck extensions was investigated through numerical and experimental methods. A
numerical parametric analysis was carried out using the Finite Element Method
with COMSOL, while experimental validation was conducted using a two-microphone
acoustic impedance tube. The analysis evaluated the effects of neck
outlet/inlet diameter ratio, neck length, and diameter of the neck on the
absorption coefficients and resonance frequency of the resonators. Results
revealed that a tapered curved embedded neck configuration led to a lower
absorption frequency as the outlet/inlet ratio increased trend to convergent
neck geometry. Furthermore, a longer effective neck length and smaller neck
diameter enhanced low-frequency noise absorption. Experimental validation with
four 3D-printed samples confirmed these trends.",2309.09852v1
2023-09-28,Analysis of $Ξ(1620)$ resonance with chiral unitary approach,"Recently, the $\Xi(1620)$ resonance has attracted much attention, thanks to
detailed experimental data by the Belle and ALICE collaborations. This
experimental progress has prepared us to conduct theoretical analyses based on
experimental data. In this study, we analyze the $\Xi(1620)$ resonance using
the chiral unitary model and discuss the properties of the $\Xi(1620)$
resonance and the $K^-\Lambda$ scattering length.",2309.16420v1
2023-10-05,Resonant Schrödinger Cat States in Circuit Quantum Electrodynamics,"We propose a fast scheme to generate Schr\""odinger cat states in a
superconducting resonator using a continuously driven qubit without resorting
to the dispersive regime, two-photon drives, or engineered two-photon
dissipation. We provide analysis for when the qubit is on and off resonance
from the drive. We extend our analysis to account for a third level in a
weakly-anharmonic qutrit. We also discuss the case of a strongly-anharmonic
qutrit. Throughout the paper, we corroborate our analytical results with
numerical simulations in the presence of energy relaxation and dephasing of the
qubit and resonator using realistic experimental parameters.",2310.03854v2
2023-10-23,Resonance of Vector Vortex Beams in a Triangular Optical Cavity,"We experimentally demonstrate resonance of first-order vector vortex beams
(VVB) with a triangular optical cavity. We also show that, due to their
symmetry properties, the so-called radial and azimuthal VVBs do not resonate at
the same cavity length, which could be explored to use the triangular resonator
as a mode sorter. In addition, an intracavity Pancharatnam phase shifter (PPS)
is implemented in order to compensate for any birefringent phase that the
cavity mirrors may introduce.",2310.15391v1
2023-11-10,Hadronic resonance production with ALICE at the LHC,"Hadronic resonance production plays an important role both in elementary and
in nucleus-nucleus collisions. In heavy-ion collisions, since the lifetimes of
short-lived resonances are comparable with the lifetime of the late hadronic
phase, regeneration and rescattering effects become important and ratios of
yields of resonances relative to those of longer lived particles can be used to
estimate the time interval between the chemical and kinetic freeze-out. The
measurements in pp and p--Pb collisions constitute a reference for nuclear
collisions and provide information for tuning event generators inspired by
Quantum Chromodynamics.",2311.05885v1
2023-11-22,From local to nonlocal high-Q plasmonic metasurfaces,"The physics of bound states in the continuum (BICs) allows to design and
demonstrate optical resonant structures with large values of the quality factor
($Q$-factor) by employing dielectric structures with low losses. However, BIC
is a general wave phenomenon that should be observed in many systems, including
the metal-dielectric structures supporting plasmons where the resonances are
hindered by losses. Here we develop a comprehensive strategy to achieve
high-$Q$ resonances in plasmonic metasurfaces by effectively tailoring the
resonant modes from local and nonlocal regimes.",2311.13452v1
2023-12-16,The 95 GeV Excess in the Georgi-Machacek Model: Single or Twin Peak Resonance,"In this work, we address the excess observed around 95 GeV in the
$\gamma\gamma$, $\tau\tau$, and $b\bar{b}$ channels as a scalar resonance(s)
within the Georgi-Machacek (GM) model. In our analysis, we find that this
excess can be accommodated in the three channels simultaneously, where the
candidate could be either a CP-even single peak resonance (SPR) or
mass-degenerate CP-even and CP-odd scalars, i.e., twin peak resonance (TPR). We
demonstrate that the nature of the 95 GeV scalar candidate (SPR or TPR) can be
probed via the properties of its di-tau decay.",2312.10484v1
2024-01-11,Impact of the molecular resonances on the 12C+12C fusion reaction rate,"The properties of the low-energy 12C+12C molecular resonances, which
potentially enhance the fusion reaction rate at low temperatures, have been
investigated by a full-microscopic nuclear model employing various nuclear
energy density functionals. We show that some density functionals plausibly
describe the observed high-spin 12C+12C molecular resonances and predict many
0+ and 2+ resonances at low energies, which enhance the reaction rate. We also
discuss how the uncertainty in the nuclear energy density functionals
propagates to that of the reaction rate.",2401.05803v1
2024-01-17,A Distributed Magnetostatic Resonator,"This work reports the design, fabrication, and characterization of
coupling-enhanced magnetostatic forward volume wave resonators with significant
spur suppression. The fabrication is based on surface micro-machining of
yttrium iron garnet (YIG) film on a gadolinium gallium garnet (GGG) substrate
with thick gold transducers. A distributed resonator is used to excite forward
volume waves in YIG to realize a frequency dependent coupling boost. Fabricated
devices at 18 GHz and 7 GHz show coupling coefficients as high as 13$\%$ and
quality factors above 1000. Higher-order magnetostatic mode suppression is
experimentally demonstrated through a combination of transducer and YIG
geometry design. An edge-coupling filter topology is proposed and simulated
which utilizes this novel distributed magnetostatic resonator.",2401.08911v1
2024-02-03,Observability of cyclotron resonance in the hydrodynamic regime of bilayer graphene,"We offer theoretical predictions for the frequency of the resonant frequency
of transport for the hydrodynamic description of bilayer graphene, as well as
provide quantification for the relative strength of this signal throughout
phase space. Our calculations are based on classical fluid dynamics equations
derived from the Boltzmann equation for bilayer graphene in arXiv:1901.07039,
and suggest that while this resonance is accessible to current experimental
techniques, the same mechanism which causes the hydrodynamic resonance to
differ from the Fermi liquid value is responsible for a significant broadening
of the peak.",2402.02231v1
2024-02-06,Terahertz plasmonic resonances in coplanar graphene nanoribbon structures,"We analyze plasmonic oscillations in the coplanar graphene nanoribbon (GNR)
structures induced by the applied terahertz (THz) signals and calculate the GNR
impedance. The plasmonic oscillations in the CNR structures are associated with
the electron and hole inductances and the lateral inter-CNR capacitance. A
relatively low inter-GNR capacitance enables the resonant excitation of the THz
plasmonic oscillations in the CNR structures with long GNRs. The GNR structures
under consideration can be used in different THz devices as the resonant
structures incorporated in THz detectors, THz sources using resonant-tunneling
diodes, photomixers, and surface acoustic wave sensors.",2402.03912v2
2024-02-07,Critical axis of Ruelle resonances for Anosov flow with a potential,"We combine methods from microlocal analysis and dimension theory to study
resonances with largest real part for an Anosov flow with smooth real valued
potential. We show that the resonant states are closely related to special
systems of measures supported on the stable manifolds introduced by Climenhaga.
As a result, we relate the presence of the resonances on the critical axis to
mixing properties of the flow with respect to certain equilibrium measures and
show that these equilibrium measures can be reconstructed from the spectral
theory of the Anosov flow.",2402.04948v1
2023-12-12,An entertaining resonance experiment with just two spring scales,"Resonance is a topic included in most introductory physics courses. Any
mechanical system experiences resonance if it is driven by a periodic force
with a frequency that matches its natural frequency. There are plenty of simple
demonstrations of the resonance phenomena of mechanical systems which can be
set up using readily available items . This work presents a very simple
approach to demonstrate the phenomena using just two spring scales. The
experiment presented here performs a ""frequency sweep"" and is also very
entertaining to watch.",2402.07904v1
2024-02-13,Near-field optomechanical transduction enhanced by Raman gain,"Raman-gain-enhanced near-field optomechanical transduction between a movable
optical cavity and SiN-membrane resonator is demonstrated. The Raman gain
compensates for the intrinsic loss of the cavity and amplifies the
optomechanical transduction, through which the membrane vibration is sensed
using a high-Q whispering-gallery-mode optical cavity evanescently. The optical
Q of the cavity resonance is improved with respect to the optical pump power,
which results in an increase in the optomechanically transduced vibration
signals of the mechanical resonator. Our near-field optomechanical coupling
approach with optical gain realizes highly sensitive displacement measurement
in nano- and micro-mechanical resonators consisting of arbitrary materials and
structures.",2402.08179v1
2024-03-27,Trineutron resonances in the SS-HORSE-NCSM approach,"The SS-HORSE-NCSM method is generalized to the case of democratic decay into
an odd number of fragments. This method is applied to the search for resonances
in three-neutron system (trineutron) using ab initio No-Core Shell Model
calculations with realistic nucleon-nucleon potentials. The $3/2^-$ and $1/2^-$
strongly overlapping resonances are predicted when softened $NN$ interactions
are used and are preferred over the case where bare $NN$ interactions of the
chiral effective field theory are used with no resonance obtained.",2403.18232v1
2024-04-03,Design of a resonant slow extraction from low emittance electron booster rings using transverse resonance island buckets,"In this contribution we present the design of a resonant slow extraction
based on the radio frequency knock-out (RF-KO) scheme, where we make use of the
transverse resonance islands bucket (TRIB) optics. The generation of the TRIB
optics is presented in two example lattices, that are considered for the
potential upgrade of the current booster ring for the PETRA synchrotron
radiation source at DESY. Simulations show an extraction efficiency in excess
of 98% with a septum blade thickness of \SI{30}{\micro\meter}.",2404.02665v1
2007-08-31,"A resonant-term-based model including a nascent disk, precession, and oblateness: application to GJ 876","Investigations of two resonant planets orbiting a star or two resonant
satellites orbiting a planet often rely on a few resonant and secular terms in
order to obtain a representative quantitative description of the system's
dynamical evolution. We present a semianalytic model which traces the orbital
evolution of any two resonant bodies in a first- through fourth-order
eccentricity or inclination-based resonance dominated by the resonant and
secular arguments of the user's choosing. By considering the variation of
libration width with different orbital parameters, we identify regions of phase
space which give rise to different resonant ''depths,'' and propose methods to
model libration profiles. We apply the model to the GJ 876 extrasolar planetary
system, quantify the relative importance of the relevant resonant and secular
contributions, and thereby assess the goodness of the common approximation of
representing the system by just the presumably dominant terms. We highlight the
danger in using ''order'' as the metric for accuracy in the orbital solution by
revealing the unnatural libration centers produced by the second-order, but not
first-order, solution, and by demonstrating that the true orbital solution lies
somewhere ''in-between'' the third- and fourth-order solutions. We also present
formulas used to incorporate perturbations from central-body oblateness and
precession, and a protoplanetary or protosatellite thin disk with gaps, into a
resonant system. We quantify these contributions to the GJ 876 system, and
thereby highlight the conditions which must exist for multi-planet exosystems
to be significantly influenced by such factors. We find that massive enough
disks may convert resonant libration into circulation; such disk-induced
signatures may provide constraints for future studies of exoplanet systems.",0709.0005v1
2008-05-05,On-chip Integration of High-Frequency Electron Paramagnetic Resonance Spectroscopy and Hall-Effect Magnetometry,"A sensor that integrates high sensitivity micro-Hall effect magnetometry and
high-frequency electron paramagnetic resonance spectroscopy capabilities on a
single semiconductor chip is presented. The Hall-effect magnetometer was
fabricated from a two dimensional electron gas GaAs/AlGaAs heterostructure in
the form of a cross, with a 50x50 um2 sensing area. A high-frequency microstrip
resonator is coupled with two small gaps to a transmission line with a 50 Ohms
impedance. Different resonator lengths are used to obtain quasi-TEM fundamental
resonant modes in the frequency range 10-30 GHz. The resonator is positioned on
top of the active area of the Hall-effect magnetometer, where the magnetic
field of the fundamental mode is largest, thus optimizing the conversion of
microwave power into magnetic field at the sample position. The two gaps
coupling the resonator and transmission lines are engineered differently. The
gap to the microwave source is designed to optimize the loaded quality factor
of the resonator (Q = 150) while the gap for the transmitted signal is larger.
This latter gap minimizes losses and prevents distortion of the resonance while
enabling measurement of the transmitted signal. The large filling factor of the
resonator permits sensitivities comparable to that of high-quality factor
resonant cavities. The integrated sensor enables measurement of the
magnetization response of micron scale samples upon application of microwave
fields. In particular, the combined measurement of the magnetization change and
the microwave power under cw microwave irradiation of single crystal of
molecular magnets is used to determine of the energy relaxation time of the
molecular spin states. In addition, real time measurements of the magnetization
dynamics upon application of fast microwave pulses are demonstrated",0805.0565v1
2009-07-28,Planetary Migration and Eccentricity and Inclination Resonances in Extrasolar Planetary Systems,"The differential migration of two planets due to planet-disk interaction can
result in capture into the 2:1 eccentricity-type mean-motion resonances. Both
the sequence of 2:1 eccentricity resonances that the system is driven through
by continued migration and the possibility of a subsequent capture into the 4:2
inclination resonances are sensitive to the migration rate within the range
expected for type II migration. If the migration rate is fast, the resonant
pair can evolve into a family of 2:1 eccentricity resonances different from
those found by Lee (2004). This new family has outer orbital eccentricity e_2 >
0.4-0.5, asymmetric librations of both eccentricity resonance variables, and
orbits that intersect if they are exactly coplanar. Although this family exists
for an inner-to-outer planet mass ratio m_1/m_2 > 0.2, it is possible to evolve
into this family by fast migration only for m_1/m_2 > 2. Thommes and Lissauer
(2003) have found that a capture into the 4:2 inclination resonances is
possible only for m_1/m_2 < 2. We show that this capture is also possible for
m_1/m_2 > 2 if the migration rate is slightly slower than that adopted by
Thommes and Lissauer. There is significant theoretical uncertainty in both the
sign and the magnitude of the net effect of planet-disk interaction on the
orbital eccentricity of a planet. If the eccentricity is damped on a timescale
comparable to or shorter than the migration timescale, e_2 may not be able to
reach the values needed to enter either the new 2:1 eccentricity resonances or
the 4:2 inclination resonances. Thus, if future observations of extrasolar
planetary systems were to reveal certain combinations of mass ratio and
resonant configuration, they would place a constraint on the strength of
eccentricity damping during migration, as well as on the migration rate itself.",0907.4838v1
2013-04-15,Deterministic Many-Resonator W Entanglement of Nearly Arbitrary Microwave States via Attractive Bose-Hubbard Simulation,"Multipartite entanglement of large numbers of physically distinct linear
resonators is of both fundamental and applied interest, but there have been no
feasible proposals to date for achieving it. At the same time, the Bose-Hubbard
model with attractive interactions (ABH) is theoretically known to have a phase
transition from the superfluid phase to a highly entangled nonlocal
superposition, but observation of this phase transition has remained out of
experimental reach. In this theoretical work, we jointly address these two
problems by (1) proposing an experimentally accessible quantum simulation of
the ABH phase transition in an array of tunably coupled superconducting circuit
microwave resonators and (2) incorporating the simulation into a highly
scalable protocol that takes as input any microwave resonator state with
negligible occupation of number states |0> and |1> and nonlocally superposes it
across the whole array of resonators. The large-scale multipartite entanglement
produced by the protocol is of the W-type, which is well-known for its
robustness. The protocol utilizes the ABH phase transition to generate the
multipartite entanglement of all of the resonators in parallel, and is
therefore deterministic and permits an increase in resonator number without
increase in protocol complexity; the number of resonators is limited instead by
system characteristics such as resonator frequency disorder and inter-resonator
coupling strength. Only one local and two global controls are required for the
protocol. We numerically demonstrate the protocol with realistic system
parameters, and estimate that current experimental capabilities can realize the
protocol with high fidelity for greater than 40 resonators.",1304.4065v4
2013-04-16,An analysis method for transmission measurements of superconducting resonators with applications to quantum-regime dielectric-loss measurements,"Superconducting resonators provide a convenient way to measure loss tangents
of various dielectrics at low temperature. For the purpose of examining the
microscopic loss mechanisms in dielectrics, precise measurements of the
internal quality factor at different values of energy stored in the resonators
are required. Here, we present a consistent method to analyze a LC
superconducting resonator coupled to a transmission line. We first derive an
approximate expression for the transmission S-parameter $S_{21}$ based on a
complete circuit model. In the weak coupling limit, we show that the internal
quality factor is reliably determined by fitting the approximate form of
$S_{21}$. Since the voltage $V$ of the capacitor of the LC circuit is required
to determine the energy stored in the resonator, we next calculate the relation
between $V$ and the forward propagating wave voltage $V_{in}^+$. Due to the
dependence of the quality factor on voltage, $V$ is not simply proportional to
$V_{in}^+$. We find a self-consistent way to determine the relation between $V$
and $V_{in}^+$, which employs only the fitting parameters for $S_{21}$ and a
linear scaling factor. We then examine the resonator transmission in the cases
of port reflection and impedance mismatch. We find that resonator transmission
asymmetry is primarily due to the reflection from discontinuity in transmission
lines. We show that our analysis method to extract the internal quality factor
is robust in the non-ideal cases above. Finally, we show that the analysis
method on LC resonator can be generalize to arbitrary weakly coupled lumped and
distributed resonators. The generalization uses a systematic approximation on
the response function based on the pole and zero which are the closest to the
resonance frequency. This Closest Pole and Zero Method (CPZM) is a valuable
tool for analyzing physical measurements of high-Q resonators.",1304.4533v2
2013-05-15,Multi-resonance orbital model of high-frequency quasi-periodic oscillations: possible high-precision determination of black hole and neutron star spin,"Using known frequencies of the twin-peak high-frequency quasiperiodic
oscillations (HF QPOs) and known mass of the central black hole, the black-hole
dimensionless spin can be determined by assuming a concrete version of the
resonance model. However, a wide range of observationally limited values of the
black hole mass implies low precision of the spin estimates. We discuss the
possibility of higher precision of the black hole spin measurements in the
framework of a multi-resonance model inspired by observations of more than two
HF QPOs in the black hole systems, which are expected to occur at two (or more)
different radii of the accretion disc. For the black hole systems we focus on
the special case of duplex frequencies, when the top, bottom, or mixed
frequency is common at two different radii where the resonances occur giving
triple frequency sets. The sets of triple frequency ratios and the related spin
are given. The strong resonance model for ""magic"" values of the black hole spin
means that two (or more) versions of resonance could occur at the same radius,
allowing cooperative effects between the resonances. For neutron star systems
we introduce a resonant switch model that assumes switching of oscillatory
modes at resonant points. In the case of doubled twin-peak HF QPOs excited at
two different radii with common top, bottom, or mixed frequency, the black hole
spin is given by the triple frequency ratio set. The spin is determined
precisely, but not uniquely, because the same frequency set could correspond to
more than one concrete spin. The black hole mass is given by the magnitude of
the observed frequencies. The resonant switch model puts relevant limits on the
mass and spin of neutron stars, and we expect a strong increase in the fitting
procedure precision when different twin oscillatory modes are applied to data
in the vicinity of different resonant points.",1305.3552v1
2014-12-26,Theoretical investigation of the decay of the $N(2120)$ resonance to nucleon resonances near 1.7 GeV,"Background: Until now the knowledge about nucleon resonances with a mass
higher than 2 GeV has been scarce. Huge amounts of experimental data of the
multipion photoproduction have been accumulated, and more can be expected in
the future in facilities such as JLab 12 GeV. It makes it possible to
investigate the decay of a nucleon resonance into another nucleon resonance.
Purpose: The possibility to research the decay of the $N(2120)$ to nucleon
resonances near 1.7 GeV in the three-pion photoproduction will be explored to
provide useful information for future experimental study. Method: The pion and
radiative decay amplitudes of nucleon resonances are studied within the
constituent quark model, which is used to calculate the couplings constants,
especially for the decay of a nucleon resonance near 2.1 GeV to another nucleon
resonance near 1.7 GeV. The three-pion photoproduction off the neutron target,
i.e.,$\gamma n \to\pi^{-}\pi^{-}\Delta^{++}\to \pi^{-}\pi^{-}\pi^+ p$, is
investigated based on the effective Lagrangian method with the coupling
constant obtained form the decay amplitudes. Results: The resonance
contribution with a state $N(^2P_M)\frac{3}{2}^{-}$ near 2.1 GeV decaying to a
state $N(^4P_M)\frac{5}{2}^{-}$ near 1.7 GeV, i.\ e., $N(2120)\to N(1675)\pi$
is dominant in the process considered. The total cross section from the
resonance contribution is at the order of 1 $\mu$b and can be easily
distinguished from the background. Conclusions: Our results suggest it is
practicable to research the decay of the $N(2120)$ to the $N(1675)$ in
experiment.",1412.7947v2
2015-03-30,Hidden Glashow resonance in neutrino-nucleus collisions,"Today it is widely believed that $s$-channel excitation of an on-shell~$W$
boson, commonly known as the Glashow resonance, can be initiated in matter only
by the electron antineutrino in the process $\bar\nu_ee^-\rightarrow W^-$ at
the laboratory energy around~6.3~PeV. In this paper we argue that the Glashow
resonance within the Standard Model also occurs in neutrino--nucleus
collisions. The main conclusions are as follows. 1)~The Glashow resonance can
be excited by both~neutrinos and~antineutrinos of all the three flavors
scattering in the Coulomb field of a nucleus. 2)~The Glashow resonance in a
neutrino--nucleus reaction does not manifest itself as a Breit--Wigner-like
peak in the cross section but the latter exhibits instead a slow
logarithmic-law growth with the neutrino energy. The resonance turns thus out
to be hidden. 3)~More than~$98\%$ of~$W$ bosons produced in the sub-PeV region
in neutrino-initiated reactions in water/ice will be from the Glashow
resonance. 4)~The vast majority of the Glashow resonance events in a neutrino
detector is expected at energies from a few TeV to a few tens of TeV, being
mostly initiated by the conventional atmospheric neutrinos dominant in this
energy range. Calculations of the cross sections for Glashow resonance
excitation on the oxygen nucleus as well as on the proton are carried out in
detail. The results of this paper can be useful for studies of neutrino
interactions at large volume water/ice neutrino detectors. For example, in the
IceCube detector one can expect~0.3 Glashow resonance events with shower-like
topologies and the deposited energies above~$300~\text{TeV}$ per year. It is
therefore likely already to have at least one Glashow resonance event in the
IceCube data set.",1503.08817v2
2016-04-27,OSSOS III - Resonant Trans-Neptunian Populations: Constraints from the first quarter of the Outer Solar System Origins Survey,"The first two observational sky ""blocks"" of the Outer Solar System Origins
Survey (OSSOS) have significantly increased the number of well-characterized
observed trans-Neptunian objects (TNOs) in Neptune's mean motion resonances. We
describe the 31 securely resonant TNOs detected by OSSOS so far, and we use
them to independently verify the resonant population models from the
Canada-France Ecliptic Plane Survey (CFEPS; Gladman et al. 2012), with which we
find broad agreement. We confirm that the 5:2 resonance is more populated than
models of the outer Solar System's dynamical history predict; our minimum
population estimate shows that the high eccentricity (e>0.35) portion of the
resonance is at least as populous as the 2:1 and possibly as populated as the
3:2 resonance. One OSSOS block was well-suited to detecting objects trapped at
low libration amplitudes in Neptune's 3:2 resonance, a population of interest
in testing the origins of resonant TNOs. We detected three 3:2 objects with
libration amplitudes below the cutoff modeled by CFEPS; OSSOS thus offers new
constraints on this distribution. The OSSOS detections confirm that the 2:1
resonance has a dynamically colder inclination distribution than either the 3:2
or 5:2 resonances. Using the combined OSSOS and CFEPS 2:1 detections, we
constrain the fraction of 2:1 objects in the symmetric mode of libration to be
0.2-0.85; we also constrain the fraction of leading vs. trailing asymmetric
librators, which has been theoretically predicted to vary depending on
Neptune's migration history, to be 0.05-0.8. Future OSSOS blocks will improve
these constraints.",1604.08177v1
2018-04-04,Neptune's 5:2 Resonance in the Kuiper Belt,"Observations of Kuiper belt objects (KBOs) in Neptune's 5:2 resonance present
two puzzles: this third order resonance hosts a surprisingly large population,
comparable to the prominent populations of Plutinos and Twotinos in the first
order 3:2 and 2:1 resonances, respectively; secondly, their eccentricities are
concentrated near $0.4$. To shed light on these puzzles, we investigate the
phase space near this resonance with use of Poincar\'e sections of the circular
planar restricted three body model. We find several transitions in the phase
space structure with increasing eccentricity, which we explain with the
properties of the resonant orbit relative to Neptune's. The resonance width is
narrow for very small eccentricities, but widens dramatically for
$e\gtrsim0.2$, reaching a maximum near $e\approx0.4$, where it is similar to
the maximum widths of the 2:1 and 3:2 resonances. We confirm these results with
N-body numerical simulations, including the effects of all four giant planets
and a wide range of orbital inclinations of the KBOs. We find that the
boundaries of the stable resonance zone are not strongly sensitive to
inclination and remain very similar to those found with the simplified three
body model, with the caveat that orbits of eccentricity above $\sim0.53$ are
unstable; higher eccentricity orbits are phase-protected from destabilizing
encounters with Neptune but not with Uranus. These results show that the 5:2
resonant KBOs are not more puzzling than the Plutinos and Twotinos; however,
detailed understanding of the origins of eccentric, inclined resonant KBOs
remains a challenge.",1804.01209v2
2016-11-20,Migration of Planets Into and Out of Mean Motion Resonances in Protoplanetary Disks: Analytical Theory of Second-Order Resonances,"Recent observations of Kepler multi-planet systems have revealed a number of
systems with planets very close to second-order mean motion resonances (MMRs,
with period ratio $1:3$, $3:5$, etc.) We present an analytic study of resonance
capture and its stability for planets migrating in gaseous disks. Resonance
capture requires slow convergent migration of the planets, with sufficiently
large eccentricity damping timescale $T_e$ and small pre-resonance
eccentricities. We quantify these requirements and find that they can be
satisfied for super-Earths under protoplanetary disk conditions. For planets
captured into resonance, an equilibrium state can be reached, in which
eccentricity excitation due to resonant planet-planet interaction balances
eccentricity damping due to planet-disk interaction. We show that this
""captured"" equilibrium can be overstable, leading to partial or permanent
escape of the planets from the resonance. In general, the stability of the
captured state depends on the inner to outer planet mass ratio $q=m_1/m_2$ and
the ratio of the eccentricity damping times. The overstability growth time is
of order $T_e$, but can be much larger for systems close to the stability
threshold. For low-mass planets undergoing type I (non-gap opening) migration,
convergent migration requires $q \lesssim 1$, while the stability of the
capture requires $q\gtrsim 1$. These results suggest that planet pairs stably
captured into second-order MMRs have comparable masses. This is in contrast to
first-order MMRs, where a larger parameter space exists for stable resonance
capture. We confirm and extend our analytical results with $N$-body
simulations, and show that for overstable capture, the escape time from the MMR
can be comparable to the time the planets spend migrating between resonances.",1611.06463v2
2018-05-23,Bound states in the continuum and Fano resonances in the strong mode coupling regime,"The study of resonant dielectric nanostructures with high refractive index is
a new research direction in nanoscale optics and metamaterial-inspired
nanophotonics. Because of the unique optically-induced electric and magnetic
Mie resonances, high-index nanoscale structures are expected to complement or
even replace different plasmonic components in a range of potential
applications. Here we study strong coupling between modes of a single
subwavelength high-index dielectric resonator and analyse the mode
transformation and Fano resonances when resonator's aspect ratio varies. We
demonstrate that strong mode coupling results in resonances with high quality
factors, which are related to the physics of bound states in the continuum when
the radiative losses are almost suppressed due to the Friedrich-Wintgen
scenario of destructive interference. We explain the physics of these states in
terms of multipole decomposition and show that their appearance is accompanied
by drastic change of the far-field radiation pattern. We reveal a fundamental
link between the formation of the high-quality resonances and peculiarities of
the Fano parameter in the scattering cross-section spectra. Our theoretical
findings are confirmed by microwave experiments for the scattering of a
high-index cylindrical resonators with a tunable aspect ratio. The proposed
mechanism of the strong mode coupling in single subwavelength high-index
resonators accompanied by resonances with high quality factor helps to extend
substantially functionalities of all-dielectric nanophotonics that opens new
horizons for active and passive nanoscale metadevices.",1805.09265v2
2017-12-12,Single-particle Mass Spectrometry with arrays of frequency-addressed nanomechanical resonators,"One of the main challenges to overcome to perform nanomechanical Mass
Spectrometry (NEMS-MS) analysis in a practical time frame stems from the size
mismatch between the analyte beam and the extremely small nanomechanical
detector area. We report here the demonstration of NEMS-MS with arrays of 20
individually addressed nanomechanical resonators where the number of
inputs-outputs for the whole array is the same as that of a single resonator.
While all resonators within an array are interconnected via two metal levels,
each resonator is designed with a distinct resonance frequency which becomes
its individual address. In order to perform single-particle Mass Spectrometry,
the resonance frequencies of the two first modes of each NEMS within an array
are monitored simultaneously. Using such an array, mass spectra of metallic
aggregates in the MDa range are acquired with more than one order of magnitude
improvement in analysis time due to the increase in capture cross section
compared to individual resonators. A 20 NEMS array is probed in 150ms with the
same mass limit of detection as a single resonator. Spectra acquired with a
conventional Time- of-Flight (TOF) mass spectrometer in the same system show
excellent agreement. As individual information for each resonator within the
array is retained, the array becomes a particle imager, each resonator acting
as a pixel. With this technique, we demonstrate how Mass Spectrometry Imaging
(MSI) at the single particle level becomes possible by mapping a 4cm-particle
beam in the MDa range and above.",1712.06694v1
2018-10-15,Identifying structures in the continuum: Application to $^{16}$Be,"The population and decay of two-nucleon resonances offer exciting new
opportunities to explore dripline phenomena. The understanding of these systems
requires a solid description of the three-body (core+N+N) continuum. The
identification of a state with resonant character from the background of
non-resonant continuum states in the same energy range poses a theoretical
challenge. It is the purpose of this work to establish a robust theoretical
framework to identify and characterize three-body resonances in a discrete
basis. A resonance operator is proposed, which describes the sensitivity to
changes in the potential. Resonances are then identified from the lowest
eigenstates of the resonance operator. The operator is diagonalized in a basis
of Hamiltonian pseudostates, built within the hyperspherical harmonics
formalism using the analytical THO basis. The energy and width of the resonance
are determined from its time dependence. The method is applied to 16Be in a
14Be+n+n model. An effective core+n potential, fitted to the available
information on the subsystem 15Be, is employed. The 0+ ground state resonance
of 16Be presents a strong dineutron configuration, which favors the picture of
a correlated two-neutron emission. Fitting the three body interaction to the
experimental two-neutron separation energy |S2n|=1.35(10) MeV, the computed
width is Gamma(0+)=0.16 MeV. From the same Hamiltonian, a 2+ resonance is also
predicted with E_r(2+)=2.42 MeV and Gamma(2+)=0.40 MeV. The dineutron
configuration and the computed 0+ width are consistent with previous R-matrix
calculations for the true three-body continuum. The extracted values of the
resonance energy and width converge with the size of the pseudostate basis and
are robust under changes in the basis parameters. This supports the reliability
of the method in describing the properties of unbound core+N+N systems in a
discrete basis.",1810.06447v2
2021-05-25,Integrated Reference Cavity for Dual-mode Optical Thermometry and Frequency Stabilization,"Optical frequency stabilization is a critical component for precision
scientific systems including quantum sensing, precision metrology, and atomic
timekeeping. Ultra-high quality factor photonic integrated optical resonators
are a prime candidate for reducing their size, weight and cost as well as
moving these systems on chip. However, integrated resonators suffer from
temperature-dependent resonance drift due to the large thermal response as well
as sensitivity to external environmental perturbations. Suppression of the
cavity resonance drift can be achieved using precision interrogation of the
cavity temperature through the dual-mode optical thermometry. This approach
enables measurement of the cavity temperature change by detecting the resonance
difference shift between two polarization or optical frequency modes. Yet this
approach has to date only been demonstrated in bulk-optic whispering gallery
mode and fiber resonators. In this paper, we implement dual-mode optical
thermometry using dual polarization modes in a silicon nitride waveguide
resonator for the first time, to the best of our knowledge. The temperature
responsivity and sensitivity of the dual-mode TE/TM resonance difference is
180.7$\pm$2.5 MHz/K and 82.56 $\mu$K, respectively, in a silicon nitride
resonator with a 179.9E6 intrinsic TM mode Q factor and a 26.6E6 intrinsic TE
mode Q factor. Frequency stabilization is demonstrated by locking a laser to
the TM mode cavity resonance and applying the dual-mode resonance difference to
a feedforward laser frequency drift correction circuit with a drift rate
improvement to 0.31 kHz/s over the uncompensated 10.03 kHz/s drift rate. Allan
deviation measurements with dual-mode feedforward-correction engaged shows that
a fractional frequency instability of 9.6E-11 over 77 s can be achieved.",2105.12119v1
2021-07-12,Avalanches and many-body resonances in many-body localized systems,"We numerically study both the avalanche instability and many-body resonances
in strongly-disordered spin chains exhibiting many-body localization (MBL). We
distinguish between a finite-size/time MBL regime, and the asymptotic MBL
phase, and identify some ""landmarks"" within the MBL regime. Our first landmark
is an estimate of where the MBL phase becomes unstable to avalanches, obtained
by measuring the slowest relaxation rate of a finite chain coupled to an
infinite bath at one end. Our estimates indicate that the actual MBL-to-thermal
phase transition, in infinite-length systems, occurs much deeper in the MBL
regime than has been suggested by most previous studies. Our other landmarks
involve system-wide resonances. We find that the effective matrix elements
producing eigenstates with system-wide resonances are enormously broadly
distributed. This means that the onset of such resonances in typical samples
occurs quite deep in the MBL regime, and the first such resonances typically
involve rare pairs of eigenstates that are farther apart in energy than the
minimum gap. Thus we find that the resonance properties define two landmarks
that divide the MBL regime in to three subregimes: (i) at strongest disorder,
typical samples do not have any eigenstates that are involved in system-wide
many-body resonances; (ii) there is a substantial intermediate regime where
typical samples do have such resonances, but the pair of eigenstates with the
minimum spectral gap does not; and (iii) in the weaker randomness regime, the
minimum gap is involved in a many-body resonance and thus subject to level
repulsion. Nevertheless, even in this third subregime, all but a vanishing
fraction of eigenstates remain non-resonant and the system thus still appears
MBL in many respects. Based on our estimates of the location of the avalanche
instability, it might be that the MBL phase is only part of subregime (i).",2107.05642v3
2021-10-05,Role of the high-spin nucleon and delta resonances in the $KΛ$ and $KΣ$ photoproduction off the nucleon,"We have investigated the effect of nucleon and delta resonances with spins
11/2, 13/2, and 15/2 in the kaon photoproduction process $\gamma + N \to K + Y$
by using two covariant isobar models. The formalism for high-spin propagators
and interaction Lagrangians were adopted from the works of Pascalutsa and
Vrancx et al. The unknown parameters in the amplitudes, i.e., the coupling
constants and hadronic form factor cutoffs, were obtained by fitting the
calculated observables to experimental data. In the $K\Lambda$ channels the
inclusion of $N(2600)I_{1,11}$ and $N(2700)K_{1,13}$ resonances improves the
agreement between model calculations and experimental data significantly and
reduces the dominance of resonances in the model by increasing the hadronic
form factor cutoff of the Born terms. Furthermore, the inclusion of these
resonances reduces the number of resonance structures in cross sections,
including the structure in the $K^0\Lambda$ differential cross section at
$W\approx 1650$ MeV, which could become a hint of the narrow resonance. In the
$K\Sigma$ channels the inclusion of $N(2600)I_{1,11}$, $N(2700)K_{1,13}$,
$\Delta(2420)H_{3,11}$, $\Delta(2750)I_{3,13}$, and $\Delta(2950)K_{3,15}$
states also significantly improves the model and increases the hadronic form
factor cutoff of the Born terms. However, different from the $K\Lambda$
channels, the inclusion of these high-spin resonances leads to more resonance
structures in the $K^+\Sigma^0$ differential cross section. This investigation
reveals that the second and third peaks in the $K^+\Sigma^0$ differential cross
section originate from the $\Delta(2000)F_{35}$ and $N(2290)G_{19}$ resonances,
respectively. We have also evaluated the resonance properties at the pole
positions and using the Breit-Wigner method.",2110.01789v1
2021-12-01,Analysis of the nonlinear dynamics of a chirping-frequency Alfvén mode in a Tokamak equilibrium,"Chirping Alfv\'{e}n modes are considered as potentially harmful in burning
Tokamak plasmas. In this paper, the nonlinear evolution of a
single-toroidal-number chirping mode is analysed by numerical particle
simulation. This analysis can be simplified if the different resonant
phase-space structures can be investigated as isolated ones. This can be done
adopting a coordinate system that includes two constants of motion. In our
simulations, we adopt as constants of motion, the magnetic momentum and the
initial particle coordinates. For each resonant structure, a density-flattening
region is formed around the respective resonance radius, with radial width that
increases as the mode amplitude grows. It is delimited by two large negative
density gradients, drifting inward and outward. With constant mode frequency,
this density flattening would be responsible for the exhausting of the drive
when large negative density gradients leave the resonance region. The frequency
chirping, however, causes the resonance radius and the resonance region to
drift inward. This drift delays the moment in which the inner density gradient
reaches the inner boundary of the resonance region. On the other side, the
island reconstitutes around the new resonance radius; as a consequence, the
large negative density gradient further moves inward. This process continues as
long as it allows to keep the large gradient within the resonance region. When
this is no longer possible, the resonant structure ceases to be effective in
driving the mode. To further grow, the mode has to tap a different resonant
structure, possibly making use of additional frequency variations.",2112.00474v3
1997-10-24,Resonant Tidal Disruption in Galactic Nuclei,"It has recently been shown that the rate of angular momentum relaxation in
nearly-Keplerian star clusters is greatly increased by a process termed
resonant relaxation (Rauch & Tremaine 1996), who also argued that tidal
disruption of stars in galactic nuclei containing massive black holes could be
noticeably enhanced by this process. We describe here the results of numerical
simulations of resonant tidal disruption which quantitatively test the
predictions made by Rauch & Tremaine. The simulation method is based on an
N-body routine incorporating cloning of stars near the loss cone and a
semi-relativistic symplectic integration scheme. We also briefly describe the
discovery of chaos in the Wisdom-Holman symplectic integrator applied to highly
eccentric orbits and propose a modified integration scheme that remains robust
under these conditions.
  We find that resonant disruption rates exceed their non-resonant counterparts
by an amount consistent with the predictions; in particular, we estimate the
net tidal disruption rate for a fully resonant cluster to be about twice that
of its non-resonant counterpart. No significant enhancement in rates is
observed outside the critical radius. Relativistic quenching of the effect is
found to occur for hole masses M>8*10^7 solar masses. The numerical results
combined with the observed properties of galactic nuclei indicate that for most
galaxies the resonant enhancement to tidal disruption rates will be very small.",9710288v1
1997-12-03,Resonance Averaged Photoionization Cross Sections for Astrophysical Models,"We present ground state photoionization cross sections of atoms and ions
averaged over resonance structures for photoionization modeling of
astrophysical sources. The detailed cross sections calculated in the
close-coupling approximation using the R-matrix method, with resonances
delineated at thousands of energies, are taken from the Opacity Project
database TOPbase and the Iron Project, including new data for the low
ionization stages of iron Fe I--V. The resonance-averaged cross sections are
obtained by convolving the detailed cross sections with a Gaussian distribution
over the autoionizing resonances. This procedure is expected to minimize errors
in the derived ionization rates that could result from small uncertainties in
computed positions of resonances, while preserving the overall resonant
contribution to the cross sections in the important near threshold regions. The
detailed photoionization cross sections at low photon energies are complemented
by new relativistic distorted-wave calculations for Z<= 12, and from
central-field calculations for Z>12 at high energies, including inner-shell
ionization. The effective cross sections are then represented by a small number
of points that can be readily interpolated linearly for practical applications;
a Fortran subroutine and data are available. The present numerically averaged
cross sections are compared with analytic fits that do not accurately represent
the effective cross sections in regions dominated by resonances.",9712037v1
2001-04-24,Eccentric extrasolar planets from resonant Saturn mass companions,Withdrawn in current form.,0104400v3
2002-10-18,Excitation of Orbital Eccentricities by Repeated Resonance Crossings: Requirements,"Divergent migration of planets within a viscous circumstellar disk can
engender resonance crossings and dramatic excitation of orbital eccentricities.
We provide quantitative criteria for the viability of this mechanism. For the
orbits of two bodies to diverge, a ring of viscous material must be shepherded
between them. As the ring diffuses in radius by virtue of its intrinsic
viscosity, the two planets are wedged further apart. The ring mass must be
smaller than the planetary masses so that the crossing of an individual
resonance lasts longer than the resonant libration period. At the same time,
the crossing cannot be of such long duration that the disk's direct influence
on the bodies' eccentricities interferes with the resonant interaction between
the two planets. This last criterion is robustly satisfied because resonant
widths are typically tiny fractions of the orbital radius. We evaluate our
criteria not only for giant planets within gaseous protoplanetary disks, but
also for shepherd moons that bracket narrow planetary rings in the solar
system. A shepherded ring of gas orbiting at a distance of 1 AU from a
solar-type star and having a surface density of less than 500 g/cm^2, a
dimensionless alpha viscosity of 0.1, and a height-to-radius aspect ratio of
0.05 can drive two Jovian-mass planets through the 2:1 and higher-order
resonances so that their eccentricities amplify to values of several tenths.
Because of the requirement that the disk mass in the vicinity of the planets be
smaller than the planet masses, divergent resonance crossings may figure
significantly into the orbital evolution of planets during the later stages of
disk evolution, including the debris disk phase.",0210437v1
2003-01-28,Stopping inward planetary migration by a toroidal magnetic field,"We calculate the linear torque exerted by a planet on a circular orbit on a
disc containing a toroidal magnetic field. All fluid perturbations are singular
at the so--called magnetic resonances, where the Doppler shifted frequency of
the perturbation matches that of a slow MHD wave propagating along the field
line. These lie on both sides of the corotation radius. Waves propagate outside
the Lindblad resonances, and also in a restricted region around the magnetic
resonances. The magnetic resonances contribute to a significant global torque
which, like the Lindblad torque, is negative (positive) inside (outside) the
planet's orbit. Since these resonances are closer to the planet than the
Lindblad resonances, the torque they contribute dominates over the Lindblad
torque if the magnetic field is large enough. In addition, if beta=c^2/v_A^2
increases fast enough with radius, the outer magnetic resonance becomes less
important and the total torque is then negative, dominated by the inner
magnetic resonance. This leads to outward migration of the planet. Even for
beta=100 at corotation, a negative torque may be obtained. A planet migrating
inward through a nonmagnetized region of a disc would then stall when reaching
a magnetized region. It would then be able to grow to become a terrestrial
planet or the core of a giant planet. In a turbulent magnetized disc in which
the large scale field structure changes sufficiently slowly, a planet may
alternate between inward and outward migration, depending on the gradients of
the field encountered. Its migration could then become diffusive, or be limited
only to small scales.",0301556v1
2003-09-08,Resonant and Secular Families in the Kuiper Belt,"We review ongoing efforts to identify occupants of mean-motion resonances
(MMRs) and collisional families in the Edgeworth-Kuiper belt. Direct
integrations of trajectories of Kuiper belt objects (KBOs) reveal the 1:1
(Trojan), 5:4, 4:3, 3:2 (Plutino), 5:3, 7:4, 9:5, 2:1 (Twotino), and 5:2 MMRs
to be inhabited. Apart from the Trojan, resonant KBOs typically have large
orbital eccentricities and inclinations. The observed pattern of resonance
occupation is consistent with resonant capture and adiabatic excitation by a
migratory Neptune; however, the dynamically cold initial conditions prior to
resonance sweeping that are typically assumed by migration simulations are
probably inadequate. Given the dynamically hot residents of the 5:2 MMR and the
substantial inclinations observed in all exterior MMRs, a fraction of the
primordial belt was likely dynamically pre-heated prior to resonance sweeping.
A pre-heated population may have arisen as Neptune gravitationally scattered
objects into trans-Neptunian space. The spatial distribution of Twotinos offers
a unique diagnostic of Neptune's migration history. The Neptunian Trojan
population may rival the Jovian Trojan population, and the former's existence
is argued to rule out violent orbital histories for Neptune. Finally,
lowest-order secular theory is applied to several hundred non-resonant KBOs
with well-measured orbits to update proposals of collisional families. No
convincing family is detected.",0309250v1
2004-01-21,Diversity and Origin of 2:1 Orbital Resonances in Extrasolar Planetary Systems,"(Abridged) A diversity of 2:1 resonance configurations can be expected in
extrasolar planetary systems, and their geometry can provide information about
the origin of the resonances. Assembly during planet formation by the
differential migration of planets due to planet-disk interaction is one
scenario for the origin of mean-motion resonances in extrasolar planetary
systems. The stable 2:1 resonance configurations that can be reached by
differential migration of planets with constant masses and initially coplanar
and nearly circular orbits are (1) anti-symmetric configurations with the
mean-motion resonance variables theta_1 and theta_2 (in deg.) librating about 0
and 180, respectively (as in the Io-Europa pair), (2) symmetric configurations
with both theta_1 and theta_2 librating about 0 (as in the GJ 876 system), and
(3) asymmetric configurations with theta_1 and theta_2 librating about angles
far from either 0 or 180. There are, however, stable 2:1 resonance
configurations with symmetric (theta_1 = theta_2 = 0), asymmetric, and
anti-symmetric (theta_1 = 180 and theta_2 = 0) librations that cannot be
reached by differential migration of planets with constant masses and initially
coplanar and nearly circular orbits. If real systems with these configurations
are ever found, their origin would require (1) a change in the planetary mass
ratio m_1/m_2 during migration, (2) a migration scenario involving inclination
resonances, or (3) multiple-planet scattering in crowded planetary systems. We
find that the asymmetric configurations with large e_2 and the theta_1 = 180
and theta_2 = 0 configurations have intersecting orbits and that the theta_1 =
theta_2 = 0 configurations with e_1 > 0.714 have prograde periapse precessions.",0401410v2
2004-04-28,Chaos and the Effects of Planetary Migration on the Orbit of S/2000 S5 Kiviuq,"Among the many new irregular satellites that have been discovered in the last
five years, at least six are in the so-called Kozai resonance. Due to solar
perturbations, the argument of pericenter of a satellite usually precesses from
0 to 360 degrees. However, at inclinations higher than 39.3 degrees and lower
than 140.7 degrees a new kind of behavior occurs for which the argument of
pericenter oscillates around +/-90 degrees. In this work we will concentrate on
the orbital history of the saturnian satellite S/2000 S5 Kiviuq, one of the
satellites currently known to be in such resonance Kiviuq's orbit is very close
to the separatrix of the Kozai resonance. Due to perturbations from the other
jovian planets, it is expected that orbits near the Kozai separatrix may show
significant chaotic behavior. This is important because chaotic diffusion may
transfer orbits from libration to circulation, and vice versa. To identify
chaotic orbits we used two well-known methods: the Frequency Analysis Method
(Laskar 1990) and Maximum Lyapunov Exponents (Benettin et al. 1980). Our
results show that the Kozai resonance is crossed by a web of secondary
resonances, whose arguments involve combinations of the argument of pericenter,
the argument of the Great Inequality, longitude of the node, and other terms
related to the secular frequencies g5, g6, and s6. Many test orbits whose
precession period is close to the period of the Great Inequality (883 yrs), or
some of its harmonics, are trapped by these secondary resonances, and show
significant chaotic behavior. Planetary migration, by moving the locations of
these secondary resonances, may have depleted an original population of Kozai
resonators.",0404562v1
2005-11-24,Resonance Overlap is Responsible for Ejecting Planets in Binary Systems,"A planet orbiting around a star in a binary system can be ejected if it lies
too far from its host star. We find that instability boundaries first obtained
in numerical studies can be explained by overlap between sub-resonances within
mean-motion resonances (mostly of the j:1 type). Strong secular forcing from
the companion displaces the centroids of different sub-resonances, producing
large regions of resonance overlap. Planets lying within these overlapping
regions experience chaotic diffusion, which in most cases leads to their
eventual ejection. The overlap region extends to shorter-period orbits as
either the companion's mass or its eccentricity increase. Our analytical
calculations reproduce the instability boundaries observed in numerical studies
and yield the following two additional results. Firstly, the instability
boundary as a function of eccentricity is jagged; thus, the widest stable orbit
could be reduced from previously quoted values by as much as 20%. Secondly,
very high order resonances (e.g., 50:3) do not significantly modify the
instability boundary despite the fact that these weak resonances can produce
slow chaotic diffusion which may be missed by finite-duration numerical
integrations. We present some numerical evidence for the first result. More
extensive experiments are called for to confirm these conclusions. For the
special case of circular binaries, we find that the Hill criterion (based on
the critical Jacobi integral) yields an instability boundary that is very
similar to that obtained by resonance overlap arguments, making the former both
a necessary and a sufficient condition for planet instability.",0511710v1
1993-08-22,Rotation Axis Variation Due To Spin Orbit Resonance,"Rotation axis variation due to spin orbit resonance: conference report;
keywords: planetary precession, rigid body, chaos, KAM, Arnold diffusion,
averaging, celestial mechanics, classical mechanics, large deviations",9308006v1
2004-01-13,The logistic equation and a linear stochastic resonance,"We show analytically that a linear transmitter with correlated Gaussian white
noises displays a stochastic resonance. We discuss the relation of this problem
to a generalized noisy logistic equation.",0401213v1
2004-08-26,Direct numerical observation of the Euclidean resonance,"We present results of direct numerical calculations for the problem of
quantum tunneling through the time-dependent potential barrier. Computations
clearly demonstrate existence of the effect of the underbarrier resonance.",0408558v1
2005-06-13,Dependence of the superfluidity criterion on the resonance between one-particle (Bogoliubov) and two-particle series,"We study how the superfluidity depends on the resonance between one- and
two-particle series. The frequency of the spectrum of two-particle solutions in
an interval is calculated.",0506276v1
2006-01-09,Dynamical spin susceptibility and the resonance peak in the pseudogap region of the underdoped cuprate superconductors,"We present a study of the dynamical spin susceptibility in the pseudogap
region of the high-T$_c$ cuprate superconductors. We analyze and compare the
formation of the so-called resonance peak, in three different ordered states:
the $d_{x^2-y^2}$-wave superconducting (DSC) phase, the $d$-density wave (DDW)
state, and a phase with coexisting DDW and DSC order. An analysis of the
resonance's frequency and momentum dependence in all three states reveals
significant differences between them. In particular, in the DDW state, we find
that a nearly dispersionless resonance excitation exists only in a narrow
region around ${\bf Q}=(\pi,\pi)$. At the same time, in the coexisting DDW and
DSC state, the dispersion of the resonance peak near ${\bf Q}$ is significantly
changed from that in the pure DSC state. Away from $(\pi,\pi)$, however, we
find that the form and dispersion of the resonance excitation in the coexisting
DDW and DSC state and pure DSC state are quite similar. Our results demonstrate
that a detailed experimental measurement of the resonance's dispersion allows
one to distinguish between the underlying phases - a DDW state, a DSC state, or
a coexisting DDW and DSC state - in which the resonance peak emerges.",0601173v2
1999-04-07,Electroweak results from the Z resonance cross-sections and leptonic forward-backward asymmetries with the ALEPH detector,"The measurement of the Z resonance parameters and lepton forward-backward
asymmetries are presented. These are determined from a sample of 4.5 million Z
decays accumulated with the ALEPH detector at LEP1.",9904007v1
1999-07-15,Production of xi resonances in sigma induced reactions at 345 GeV/c,"We report on a measurement of the differential and total cross sections of
inclusive production of Xi resonances in Sigma - nucleus collisions at 345
GeV/c.",9907021v1
1998-05-08,Diffractive-Like (or Parametric-Resonance-Like?) Enhancement of the Earth (Day-Night) Effect for Solar Neutrinos Crossing the Earth Core,"It is shown that the strong enhancement of the Earth (day-night) effect for
solar neutrinos crossing the Earth core in the case of the small mixing angle
MSW electron neutrino to muon (tau) neutrino transition solution of the solar
neutrino problem is due to a new resonance effect in the solar neutrino
transitions in the Earth and not just to the MSW effect in the core. The effect
is in many respects similar to the electron paramagnetic resonance. The
conditions for existence of this new resonance effect are discussed. They
include specific constraints on the neutrino oscillation lengths in the Earth
mantle and in the Earth core, thus the resonance is a ``neutrino oscillation
length resonance''. The effect exhibits strong dependence on the neutrino
energy. Analytic expression for the probability accounting for the solar
neutrino transitions in the Earth, which provides a high precision description
of the transitions, including the new resonance effect, is derived. The
implications of our results for the searches of the day-night asymmetry in the
solar neutrino experiments are briefly discussed. The new resonance effect is
operative also in the muon neutrino to electron neutrino (electron neutrino to
muon neutrino) transitions of atmospheric neutrinos crossing the Earth core.",9805262v3
2003-05-06,Description of the $D^*_s(2320)$ resonance as the $Dπ$ atom,"We discuss the possibility that the recently reported resonance in the $D_s
\pi^0$ spectrum can be described in terms of residual $D\pi$ interactions.",0305060v1
2006-10-26,Meson-Baryon s-wave Resonances with Strangeness -3,"Starting from a consistent SU(6) extension of the Weinberg-Tomozawa (WT)
meson-baryon chiral Lagrangian (Phys. Rev. D74 (2006) 034025), we study the
s-wave meson-baryon resonances in the strangeness S=-3 and negative parity
sector. Those resonances are generated by solving the Bethe-Salpeter equation
with the WT interaction used as kernel. The considered mesons are those of the
35-SU(6)-plet, which includes the pseudoscalar (PS) octet of pions and the
vector (V) nonet of the rho meson. For baryons we consider the 56-SU(6)-plet,
made of the 1/2+ octet of the nucleon and the 3/2+ decuplet of the Delta.
Quantum numbers I(J^P)=0(3/2^-) are suggested for the experimental resonances
Omega*(2250)- and Omega*(2380)-. Among other, resonances with I=1 are found,
with minimal quark content sss\bar{l}l', being s the strange quark and l, l'
any of the the light up or down quarks. A clear signal for such a pentaquark
would be a baryonic resonance with strangeness -3 and electric charge of -2 or
0, in proton charge units. We suggest looking for K- Xi- resonances with masses
around 2100 and 2240 MeV in the sector 1(1/2^-), and for pi Omega- and K- Xi*-
resonances with masses around 2260 MeV in the sector 1(3/2^-).",0610353v1
2007-01-30,Quantum Corrections in the Resonance Chiral Theory,"This PhD thesis is a first step towards the control of the quantum
corrections in the Resonance Chiral Theory, the suggested framework to handle
QCD in the resonance region. After a theoretical introduction, Chapter 3 is
devoted to calculate the vector form factor of the pion at the next-to-leading
order in the 1/N(C) expansion. The ultraviolet behaviour of the calculation is
analyzed, together with the needed counterterms in the renormalization
procedure. The long-distance limit allows to determine the resonance
contribution to the low-energy constants of Chiral Perturbation Theory at the
NLO in 1/N(C). In Chapter 4 a study of the two-body hadronic form factors from
large-N(C) QCD is shown. We present a dispersive method which allows to
investigate the chiral LECs and we perform a NLO calculation of the scalar and
pseudoscalar two-point functions. Imposing the correct QCD short-distance
constraints, one determines their difference Pi(t)=Pi_S(t)-Pi_P(t) in terms of
the pion decay constant and resonance masses. Its low-momentum expansion fixes
then the ChPT coupling L(8). In Chapter 5 we evaluate the beta-function at
one-loop of the resonance lagrangian with one multiplet of scalar and
pseudoscalar resonances, up to bilinear couplings in the resonance fields, by
using the background field method.",0701248v1
2002-01-24,Some upper bounds on the number of resonances for manifolds with infinite cylindrical ends,"We prove some sharp upper bounds on the number of resonances associated with
the Laplacian, or Laplacian plus potential, on a manifold with infinite
cylidrical ends.",0201237v1
2005-06-15,Fractal upper bounds on the density of semiclassical resonances,"For semiclassical problems we establish upper bounds on the number of
resonances in boxes of size $h$ along the real axis, in terms of the dimension
of the set of trapped trajectories. The proof uses second microlocalization.",0506307v1
2005-09-17,Asymptotics of resonances for a schrodinger operator with matrix values,"we obtain the asympotics for the counting function of resonances for a matrix
valued schrodinger operator in dimension one.",0509391v3
2000-06-14,Some Comments on the RHS Formulation of Resonance Scattering,"We discuss the validity of a formula concerning a relation between
functionals in quantum resonance scattering, which is often used in the current
literature.",0006015v1
2001-03-30,Numerical computation of resonance poles in scattering theory,"We present a possible way of computing resonance poles and modes in
scattering theory. Numerical examples are given for the scattering of
electromagnetic waves by finite-size photonic crystals.",0103046v1
2001-02-27,Resonance Effects in Topological Discrete sine-Gordon System,"We consider kink-antikink collisions in the topological discrete sine-Gordon
system. We find that the TDSG kink supports extra internal modes of vibration
and this results in resonance effects of the kind seen for the continuum phi^4
theory.",0102037v1
2005-12-26,Analytical Expression for Low-dimensional Resonance Island in 4-dimensional Symplectic Map,"We study a 2- and a 4-dimensional nearly integrable symplectic maps using a
singular perturbation method. Resonance island structures in the 2- and 4-
dimensional maps are successfully obtained. Those perturbative results are
numerically confirmed.",0512073v1
2003-08-27,Resonance Production in STAR,"The recent results from resonance production in central Au+Au and p+p
collisions at $\sqrt{s_{\rm NN}} = $ 200 GeV from the STAR experiment at RHIC
are presented and discussed.",0308029v1
2004-01-06,Molecular resonance phenomena and alpha-clustering: recent progress and perspectives,"The connection between molecular resonance phenomena in light heavy-ion
collisions, alpha-clustering and extremely deformed states in light
$\alpha$-like nuclei is discussed. For example, the superdeformed bands
recently discovered in light N=Z nuclei such as $^{36}$Ar, $^{40}$Ca,
$^{48}$Cr, and $^{56}$Ni by $\gamma$-ray spectroscopy may have a special link
with resonant states in collisions with $\alpha$-like nuclei. The resonant
reactions involving identical bosons such as $^{12}$C+$^{12}$C,
$^{16}$O+$^{16}$O $^{24}$Mg+$^{24}$Mg and $^{28}$Si+$^{28}$Si are of interest.
For instance, a butterfly mode of vibration of the J$^{\pi}$ = 38$^{+}$
resonance of $^{28}$Si+$^{28}$Si has been discovered in recent particle
$\gamma$-ray angular correlations measurements. The search for signatures of
strongly deformed shapes and clustering in light N=Z nuclei is also the domain
of charged particle spectroscopy. The investigation of $\gamma$-decays in
$^{24}$Mg has been undertaken for excitation energies where previously nuclear
molecular resonances were found in $^{12}$C+$^{12}$C collisions. In this case
the $^{12}$C-$^{12}$C scattering states can be related to the breakup resonance
and, tentatively, to the resonant radiative capture $^{12}$C+$^{12}$C reaction.",0401004v1
2004-07-21,Electromagnetic Meson Production in the Nucleon Resonance Region,"Recent experimental and theoretical advances in investigating electromagnetic
meson production reactions in the nucleon resonance region are reviewed.",0407020v1
2005-06-14,Detectors for the Gamma-Ray Resonant Absorption (GRA) Method of Explosives Detection in Cargo: A Comparative Study,"Gamma-Ray Resonant Absorption (GRA) is an automatic-decision radiographic
screening technique that combines high radiation penetration with very good
sensitivity and specificity to nitrogenous explosives. The method is
particularly well-suited to inspection of large, massive objects (since the
incident gamma-ray probe is at 9.17 MeV) such as aviation and marine
containers, heavy vehicles and railroad cars. Two kinds of gamma-ray detectors
have been employed to date in GRA systems: 1) Resonant-response nitrogen-rich
liquid scintillators and 2) BGO detectors. This paper analyses and compares the
response of these detector-types to the resonant radiation, in terms of
single-pixel figures of merit. The latter are sensitive not only to detector
response, but also to accelerator-beam quality, via the properties of the
nuclear reaction that produces the resonant gamma-rays. Generally, resonant
detectors give rise to much higher nitrogen-contrast sensitivity in the
radiographic image than their non-resonant detector counterparts and
furthermore, do not require proton beams of high energy-resolution. By
comparison, the non-resonant detectors have higher gamma-detection efficiency,
but their contrast sensitivity is very sensitive to the quality of the
accelerator beam. Implications of these detector/accelerator characteristics
for eventual GRA field systems are discussed.",0506017v1
1994-12-07,A Resonance Model for pi N -> Y K and pi Delta -> Y K Reactions for Kaon Production in Heavy Ion Collisions,"In a resonance model the reactions pi N -> Y K and pi Delta -> Y K are
studied. For the reactions pi N -> Lambda K and pi Delta -> Lambda K, the
resonances N(1650)(J^P=1/2^-), N(1710)(1/2^+) and N(1720)(3/2^+) are included
as intermediate states. For the reactions pi N -> Sigma K, the resonances
N(1710)(1/2^+), N(1720)(3/2^+) and Delta(1920)(3/2^+) are considered, while for
the pi Delta -> Sigma K reactions the intermediate resonances are
N(1710)(1/2^+) and N(1720)(3/2^+). Besides these resonances in the s-channel,
the t-channel K^*(892) exchanges are also taken into account as a smooth
background. The relevant coupling constants for the meson-baryon vertices are
obtained (except for Delta(1920)) from the experimental decay branching ratios
of the relevant resonances. All isospin channels of the pi N -> Y K and pi
Delta -> Y K cross sections are calculated. By comparing the calculated results
with the available experimental data, we find that the total cross sections of
the pi N -> Y K reactions can be explained by the resonance model. The pi Delta
-> Y K cross sections, for which no experimental data are available, are
predicted theoretically. Parametrizations of the calculated total cross
sections for all different isospin channels are given for the use of kaon
productions in heavy ion collisions. The differential cross sections are also
studied.",9412011v1
1995-03-15,Heavy Resonance Production in Ultrarelativistic Nuclear Collisions,"Are heavy quarks produced thermally or only by hard parton collisions? What
is the probability that a produced heavy quark or antiquark is observed in a
given resonance?",9503015v1
1996-12-03,Meson Photoproductions of Nucleon In the Quark Model,"The meson photoproductions off nucleons in the chiral quark model are
described. The role of the S-wave resonances in the second resonance region is
discussed, and it is particularly important for the Kaon, $\eta$ and $\eta'$
photoproductions.",9612013v1
1998-07-06,On the three-body continuum spectrum of He-6,"In recent publications Cobis, Fedorov, and Jensen claim the existence of
several previously unknown low-lying narrow resonances in He-6. I show that the
distribution of the S-matrix poles corresponding to these states is unphysical.
This casts doubt on the results of those works concerning resonances.",9807016v1
1998-11-17,P- and T-violation Tests with Polarized Resonance Neutrons,"The enhancements of CP-violating effects in resonance neutron
transmissionthrough polarized targets are studied for 2 possible versions of
experiment. The importance is stressed of error analysis and of pseudomagnetic
effects' compensation.",9811059v1
2001-08-01,"The mean energy, strength and width of triple giant dipole resonances","We investigate the mean energy, strength and width of the triple giant dipole
resonance using sum rules.",0108002v1
2003-03-27,Mass Shifts through Re-scattering,"In this note we present a model that can produce a mass shift in a resonance
due to interference between a scattering amplitude and that amplitude having
rescattering through the resonance.",0303068v2
2005-08-24,Resonance states in the $^{12}$C+$^{12}$C modified Morse potential,"The resonances in $^{12}$C+$^{12}$C system described earlier using long range
Morse potential determined from resonance data itself, are reexamined in the
light of the recent development of the two new methods for identification of
resonances in the scattering theory, namely Imaginary Test Potential and
Imaginary Phase-shift methods. The high lying resonances are found to be not
genuine as pointed out by Kato and Abe, and as such are discarded. This
discomfiture is due to the (i) shallow behavior of the Morse potential at the
outer edge and (ii) inappropriate insertion of Coulomb tail used in that work.
These two deficiencies are now removed in the present study by finding a
modified Morse potential with steep rise in the outer edge, and joining
smoothly to it a term approximating the Coulomb tail. Calculation of the
resonances for this modified Morse potential using the above two methods of
identification of resonances in our study, yields more than 25 states with
angular momenta $0^{+}$ - $12^{+}$ in the relevant energy regions. This
reaffirms the diatomic-like rotational and vibrational picture of the nuclear
molecular resonances in $^{12}$C+$^{12}$C system proposed earlier, and shows
close resemblance with the physics of diatomic molecules, a phenomenon
belonging to altogether a different area. It is revealing that the similarity
extends right upto the level of potential which is Morse type in both the
cases. This study also reveals new features of heavy ion potential.",0508046v1
2006-11-10,Study of nucleon resonances with electromagnetic interactions,"Recent developments in using electromagnetic meson production reactions to
study the structure of nucleon resonances are reviewed. Possible future works
are discussed.",0611034v1
1998-09-21,Observation of proximity resonances in a parallel-plate waveguide,"We have observed proximity resonances in a two dimensional system consisting
of dielectric scatterers in a parallel plate waveguide. A numerical solution to
the scattering problem supports the analysis of the experimental data.",9809031v1
2002-11-06,The Nobel Prize in Physics 2002 for the observation of cosmic neutrinos,"A brief description of the work for which the first half of the Nobel prize
for physics for the year 2002 is presented.",0211026v1
2003-12-08,Simple external cavity diode laser,"A semiconductor diode laser having a modified Littrow external resonator is
described. An additional output coupling mirror in a V-shape configuration of
the resonator makes the system more efficient and convenient to operate.",0312047v1
2004-10-08,Identification of Local Alfven Wave Resonances with Reflectometry as a Diagnostic Tool in Tokamaks,"Local Alfven wave (LAW) resonances are excited in tokamak plasmas by an
externally driven electro-magnetic field, with the frequency below the ion
cyclotron frequency, where using of the Alfven waves is assumed. Recently, wave
driven density fluctuations at the LAW resonance m=+/-1, N=+/-2 with few kW
power deposition and 4 MHz frequency were detected in TCABR (Bt =1.1T, q0 =1.1,
n0=1.4-2.0 10^{19}/ m^3) using a fixed frequency (32.4GHz) O-mode
reflectometer. Here, we show that combination of small power deposition in LAW
resonances, swept by plasma density variation or scanned with generator
frequencies, in combination with detection of the density fluctuations in the
LAW resonances by reflectometry can serve as diagnostic tool for identification
of the effective ion mass number Aef and q-profile in tokamaks. The idea is
based on the simultaneous detection of the position of m=+/-1 local AW
resonances, which are excited by M/N=+/-1/+/-2 antenna modes, and m=0 generated
by poloidal mode coupling effect in tokamaks. According to LAW dispersion, the
m=0 resonance depends only on the effective ion mass number and does not depend
on the q-profile. Then, using these data we can define q-value at the position
of m=+/-1 L AW resonances. Using TAE coils with even toroidal modes (N=2, 4,..)
and AW generator in the frequency band 0.6-1 MHz, an application of this method
to Joint European Torus (Bt=2.3T, q0 =1-1.3, n0=5-7 10^19/m^3) is demonstrated.",0410048v1
1997-12-06,Localization of Quantum States at the Cyclotron Resonance,"A new type of localization - localization over the quantum resonance cells -
in an intrinsically degenerate system is explored by using the quasienergy
eigenstates.",9712015v1
1998-09-16,The effective Hamiltonian of the Pound-Overhauser controlled-NOT gate,"In NMR-based quantum computing, it is known that the controlled-NOT gate can
be implemented by applying a low-power, monochromatic radio-frequency field to
one peak of a doublet in a weakly-coupled two-spin system. This is known in NMR
spectroscopy as Pound-Overhauser double resonance. The ``transition''
Hamiltonian that has been associated with this procedure is however only an
approximation, which ignores off-resonance effects and does not correctly
predict the associated phase factors. In this paper, the exact effective
Hamiltonian for evolution of the spins' state in a rotating frame is derived,
both under irradiation of a single peak (on-transition) as well as between the
peaks of the doublet (on-resonance). The accuracy of these effective
Hamiltonians is validated by comparing the observable product operator
components of the density matrix obtained by simulation to those obtained by
fitting the corresponding experiments. It is further shown how both the
on-transition and on-resonance fields can be used to implement the
controlled-NOT gate exactly up to conditional phases, and analytic expressions
for these phases are derived. In Appendices, the on-resonance Hamiltonian is
analytically diagonalized, and proofs are given that, in the weak-coupling
approximation, off-resonance effects can be neglected whenever the
radio-frequency field power is small compared to the difference in resonance
frequencies of the two spins.",9809045v1
2004-10-17,Resonant and non-resonant Tunneling through a double barrier,"An explicit expression is obtained for the phase-time corresponding to
tunneling of a (non-relativistic) particle through two rectangular barriers,
both in the case of resonant and in the case of non-resonant tunneling. It is
shown that the behavior of the transmission coefficient and of the tunneling
phase-time near a resonance is given by expressions with ""Breit-Wigner type""
denominators. By contrast, it is shown that, when the tunneling probability is
low (but not negligible), the non-resonant tunneling time depends on the
barrier width and on the distance between the barriers only in a very weak
(exponentially decreasing) way: This can imply in various cases, as well-known,
the highly Superluminal tunneling associated with the so-called ""generalized
Hartman Effect""; but we are now able to improve and modify the mathematical
description of such an effect, and to compare more in detail our results with
the experimental data for non-resonant tunneling of photons. Finally, as a
second example, the tunneling phase-time is calculated, and compared with the
available experimental results, in the case of the quantum-mechanical tunneling
of neutrons through two barrier-filters at the resonance energy of the set-up.",0410128v2
2005-12-13,Stochastic resonance effects in quantum channels,"We provide some examples of quantum channels where the addition of noise is
able to enhance the information transmission rate. This may happen for both
quantum and classical uses and realizes stochastic resonance effects.",0512099v1
2007-05-10,"Model independent Breit-Wigner parameters of nucleon resonances S11(1535), S11(1650) and P11(1710)","Estimates of Breit-Wigner parameters of nucleon resonances were obtained by
phenomenological analysis of eta meson photoproduction on protons performed
completely by statistical procedures without appealing to theoretical models",0705.1501v1
2007-06-03,"Comment on ""Enhanced transmission through periodic arrays of subwavelength holes: the role of localized waveguide resonances""","Comment on ""Enhanced transmission through periodic arrays of subwavelength
holes: the role of localized waveguide resonances"" [Phys.Rev.Lett. 96, 233901
(2006)]",0706.0250v1
2007-06-25,Stability Limits in Resonant Planetary Systems,"The relationship between the boundaries for Hill and Lagrange stability in
orbital element space is modified in the case of resonantly interacting
planets. Hill stability requires the ordering of the planets to remain constant
while Lagrange stability also requires all planets to remain bound to the
central star. The Hill stability boundary is defined analytically, but no
equations exist to define the Lagrange boundary, so we perform numerical
experiments to estimate the location of this boundary. To explore the effect of
resonances, we consider orbital element space near the conditions in the HD
82943 and 55 Cnc systems. Previous studies have shown that, for non-resonant
systems, the two stability boundaries are nearly coincident. However the Hill
stability formula are not applicable to resonant systems, and our investigation
shows how the two boundaries diverge in the presence of a mean-motion
resonance, while confirming that the Hill and Lagrange boundaries are similar
otherwise. In resonance the region of stability is larger than the domain
defined by the analytic formula for Hill stability. We find that nearly all
known resonant interactions currently lie in this extra stable region, i.e.
where the orbits would be unstable according to the non-resonant Hill stability
formula. This result bears on the dynamical packing of planetary systems,
showing how quantifying planetary systems' dynamical interactions (such as
proximity to the Hill-stability boundary) provides new constraints on planet
formation models.",0706.3721v1
2007-07-06,On the nuclear reactions with participation of near-threshold baryon resonances,"The main features of nuclear reactions with participation of baryon
resonances ($\Delta$(1232), S(1535) and $\Lambda$(1405)), which are interpreted
as a manifestation of the bound states of nucleus and corresponding meson are
discussed.",0707.0943v1
2007-07-23,Collisional Velocities and Rates in Resonant Planetesimal Belts,"We consider a belt of small bodies around a star, captured in one of the
external or 1:1 mean-motion resonances with a massive perturber. The objects in
the belt collide with each other. Combining methods of celestial mechanics and
statistical physics, we calculate mean collisional velocities and collisional
rates, averaged over the belt. The results are compared to collisional
velocities and rates in a similar, but non-resonant belt, as predicted by the
particle-in-a-box method. It is found that the effect of the resonant lock on
the velocities is rather small, while on the rates more substantial. The
collisional rates between objects in an external resonance are by about a
factor of two higher than those in a similar belt of objects not locked in a
resonance. For Trojans under the same conditions, the collisional rates may be
enhanced by up to an order of magnitude. Our results imply, in particular,
shorter collisional lifetimes of resonant Kuiper belt objects in the solar
system and higher efficiency of dust production by resonant planetesimals in
debris disks around other stars.",0707.3369v1
2007-09-04,Resonances and O-curves in Hamiltonian systems,"We investigate the problem of the existence of trajectories asymptotic to
elliptic equilibria of Hamiltonian systems in the presence of resonances.",0709.0349v1
2007-11-14,Accurate calculation of resonances in multiple-well oscillators,"Quantum--mechanical multiple--well oscillators exhibit curious complex
eigenvalues that resemble resonances in models with continuum spectra. We
discuss a method for the accurate calculation of their real and imaginary
parts.",0711.2289v1
2008-02-01,Baryon Resonances Observed at BES,"The $\psi$ decays provide a novel way to explore baryon spectroscopy and
baryon structure. The baryon resonances observed from $\psi$ decays at BES are
reviewed. The implications and prospects at upgraded BESIII/BEPCII are
discussed.",0802.0087v1
2008-02-20,Scattering problem for the local parametric resonance equation,"In this paper we present the solution of local parametric resonance equation
in terms of parabolic cylinder functions and solve the scattering problem for
this equation.",0802.2849v1
2008-05-24,Bounded Sobolev Norms for Linear Schrödinger Equations Under Resonant Perturbations,"We prove that the Sobolev norm for a 1-D periodic Schroedinger equation
remain bounded under small resonant perturbations.",0805.3767v1
2008-08-11,High-Frequency Microstrip Cross Resonators for Circular Polarization EPR Spectroscopy,"In this article we discuss the design and implementation of a novel
microstrip resonator which allows for the absolute control of the microwaves
polarization degree for frequencies up to 30 GHz. The sensor is composed of two
half-wavelength microstrip line resonators, designed to match the 50 Ohms
impedance of the lines on a high dielectric constant GaAs substrate. The line
resonators cross each other perpendicularly through their centers, forming a
cross. Microstrip feed lines are coupled through small gaps to three arms of
the cross to connect the resonator to the excitation ports. The control of the
relative magnitude and phase between the two microwave stimuli at the input
ports of each line allows for tuning the degree and type of polarization of the
microwave excitation at the center of the cross resonator. The third (output)
port is used to measure the transmitted signal, which is crucial to work at low
temperatures, where reflections along lengthy coaxial lines mask the signal
reflected by the resonator. EPR spectra recorded at low temperature in an S=
5/2 molecular magnet system show that 82%-fidelity circular polarization of the
microwaves is achieved over the central area of the resonator.",0808.1524v1
2008-09-16,A Rational Approach to the Resonance Region,"Resonance Saturation in QCD can be understood in the large-Nc limit from the
mathematical theory of Pade Approximants to meromorphic functions.",0809.2704v1
2008-09-19,Mean motion resonances from planet-planet scattering,"Planet-planet scattering is the leading mechanism to explain the large
eccentricities of the observed exoplanet population. However, scattering has
not been considered important to the production of pairs of planets in mean
motion resonances (MMRs). We present results from a large number of numerical
simulations of dynamical instabilities in 3-planet systems. We show that MMRs
arise naturally in about five percent of cases. The most common resonances we
populate are the 2:1 and 3:1 MMRs, although a wide variety of MMRs can occur,
including high-order MMRs (up to eleventh order). MMRs are generated
preferentially in systems with uneven mass distributions: the smallest planet
is typically ejected after a series of close encounters, leaving the remaining,
more massive planets in resonance. The distribution of resonant planets is
consistent with the phase-space density of resonant orbits, meaning that
planets are randomly thrown into MMRs rather than being slowly pulled into
them. It may be possible to distinguish between MMRs created by scattering vs.
convergent migration in a gaseous disk by considering planetary mass ratios:
resonant pairs of planets beyond ~1 AU with more massive outer planets are
likely to have formed by scattering. In addition, scattering may be responsible
for pairs of planets in high-order MMRs (3:1 and higher) that are not easily
populated by migration. The frequency of MMRs from scattering is comparable to
the expected survival rate of MMRs in turbulent disks. Thus, planet-planet
scattering is likely to be a major contributor to the population of resonant
planets.",0809.3449v1
2008-09-24,Calculation of supercritical Dirac resonances in heavy-ion collisions,"This resonance is similar in character to other resonances in atomic physics.
It is parameterized by its energy and its lifetime. A numerical discretization
technique, the mapped Fourier grid method (MFG) is extended to the Dirac
equation and is used to solve for the resonance parameters of a quasimolecular
supercritical 1S$\sigma$ state which arises, e.g., in a uranium-uranium
collision. Direct methods using only the MFG method are shown to give
reasonable estimates for the resonance parameters. Analytic continuation
methods such as complex scaling (CS) of the coordinate or adding a complex
absorbing potential (CAP) are then applied. They allow for more accurate
determinations of the supercritical resonance parameters. The (extrapolated)
augmented analytic continuation methods are used to investigate the effects of
higher-order couplings, beyond the monopole approximation. For the nearly
charge symmetric system of U$^{92+}$-Cf$^{98+}$, it is shown that the S-D
quadrupole coupling is the next dominant interaction after the monopole
interaction. Collisions near the Coulomb barrier, in which supercritical
resonance states occur, are also calculated using the MFG. Results are
presented for the collision of U$^{92+}$-U$^{92+}$ for a zero-impact-parameter
Coulomb trajectory at a center-of-mass energy of 740MeV. The enhancement
effects to the positron spectrum due to nuclear sticking at closest approach is
examined. Results are given for sticking times of 2,5,10$\times10^{-21}$s.
Nuclear sticking is shown to offer the possibility of demonstrating
experimentally the existence of supercritical resonance states.",0809.4256v2
2008-12-09,Multiple Resonances in Fluid-Loaded Vibrating Structures,"This study deals with vibroacoustics under heavy fluid loading conditions.
Considerable attention has been and remains focused on this subject not only
because industry is very concerned but also because of mathematical
difficulties that make the numerical resolution of the problem very difficult.
It was recently observed in a numerical study on a high order perturbation
method under heavy fluid loading that a loaded vibrating plate results in a
frequency shift of the in vacuo single resonance (in both the real part because
of the fluid added mass and the imaginary part because of energy lost by
radiation into the fluid) as well as increase in the number of the resonance
frequencies : as a result of the loading, each single in vacuo resonance
frequency of the structure is transformed into a multiple resonance frequency.
Here we show that this phenomenon is said to be an extension to the heavy
loading condition of the Sanchez's classical result that have established that
in the case of a light loading conditions ""the scattering frequencies of a
fluid loaded elastic structure (ie the resonance frequencies) are nearly the
real eigenfrequencies of the elastic body alone and the complex scattering
frequencies of the fluid with a rigid solid"". Using classical results in the
framework of the theory of entire functions, it is established that a single
resonance of a simply supported fluid loaded rectangular plate is transformed
into an infinite number of resonances.",0812.1653v1
2009-01-13,Mercury's capture into the 3/2 spin-orbit resonance including the effect of core-mantle friction,"The rotation of Mercury is presently captured in a 3/2 spin-orbit resonance
with the orbital mean motion. The capture mechanism is well understood as the
result of tidal interactions with the Sun combined with planetary
perturbations. However, it is now almost certain that Mercury has a liquid
core, which should induce a contribution of viscous friction at the core-mantle
boundary to the spin evolution. This last effect greatly increases the chances
of capture in all spin-orbit resonances, being 100% for the 2/1 resonance, and
thus preventing the planet from evolving to the presently observed
configuration. Here we show that for a given resonance, as the chaotic
evolution of Mercury's orbit can drive its eccentricity to very low values
during the planet's history, any previous capture can be destabilized whenever
the eccentricity becomes lower than a critical value. In our numerical
integrations of 1000 orbits of Mercury over 4 Gyr, the spin ends 99.8% of the
time captured in a spin-orbit resonance, in particular in one of the following
three configurations: 5/2 (22%), 2/1 (32%) and 3/2 (26%). Although the present
3/2 spin-orbit resonance is not the most probable outcome, we also show that
the capture probability in this resonance can be increased up to 55% or 73%, if
the eccentricity of Mercury in the past has descended below the critical values
0.025 or 0.005, respectively.",0901.1843v1
2009-04-07,Probabilistic Interpretation of Resonant States,"We provide probabilistic interpretation of resonant states. This we do by
showing that the integral of the modulus square of resonance wave functions
(i.e., the conventional norm) over a properly expanding spatial domain is
independent of time, and therefore leads to probability conservation. This is
in contrast with the conventional employment of a bi-orthogonal basis that
precludes probabilistic interpretation, since wave functions of resonant states
diverge exponentially in space. On the other hand, resonant states decay
exponentially in time, because momentum leaks out of the central scattering
area. This momentum leakage is also the reason for the spatial exponential
divergence of resonant state. It is by combining the opposite temporal and
spatial behaviors of resonant states that we arrive at our probabilistic
interpretation of these states. The physical need to normalize resonant wave
functions over an expanding spatial domain arises because particles leak out of
the region which contains the potential range and escape to infinity, and one
has to include them in the total count of particle number.",0904.1044v2
2009-06-05,Emergence of the stochastic resonance in glow discharge plasma,"stochastic resonance, glow discharge plasma, excitable medium, absolute mean
difference",0906.1078v1
2009-06-23,Inclusive K0sK0s resonance production in ep Collisions,"Resonant structure in the inclusive K0sK0s mass spectrum is interpreted via
interference between three tensor mesons plus the production of a glueball
candidate state",0906.4200v1
2009-08-13,An Introduction to Fluorescence Resonance Energy Transfer (FRET),"Recent advances in Fluorescence Resonance Energy Transfer (FRET) provides a
way to measure and understand different biological systems and molecular
interactions in nanometer order. In this report the introduction and principle
of the FRET process have been explained.",0908.1815v1
2009-08-17,Confinement and electron correlation effects in photoionization of atoms in endohedral anions: Ne@C60^{z-},"Trends in resonances, termed confinement resonances, in photoionization of
atoms A in endohedral fullerene anions A@C60^{z-} are theoretically studied and
exemplified by the photoionization of Ne in Ne@C{60}^{z-}. Remarkably, above a
particular nl ionization threshold of Ne in neutral Ne@C60 (I_{nl}^{z=0}),
confinement resonances in corresponding partial photoionization cross sections
sigma_{nl} of Ne in any charged Ne@C60^{z-} remain almost intact by a charge z
on the carbon cage, as a general phenomenon. At lower photon energies, omega <
I_{nl}^{z=0}, the corresponding photoionization cross sections develop
additional, strong, z-dependent resonances, termed Coulomb confinement
resonances, as a general occurrence. Furthermore, near the innermost 1s
ionization threshold, the 2p photoionization cross section sigma_{2p} of the
outermost 2p subshell of thus confined Ne is found to inherit the confinement
resonance structure of the 1s photoionization spectrum, via interchannel
coupling. As a result, new confinement resonances emerge in the 2p
photoionization cross section of the confined Ne atom at photoelectron energies
which exceed the 2p threshold by about a thousand eV, i.e., far above where
conventional wisdom said they would exist. Thus, the general possibility for
confinement resonances to resurrect in photoionization spectra of encapsulated
atoms far above thresholds is revealed, as an interesting novel general
phenomenon.",0908.2465v1
2009-11-23,Brjuno conditions for linearization in presence of resonances,"We present a new proof, under a slightly different (and more natural)
arithmetic hypothesis, and using direct computations via power series
expansions, of a holomorphic linearization result in presence of resonances
originally proved by R\""ussmann.",0911.4341v1
2010-03-27,Design of Optomechanical Cavities and Waveguides on a Simultaneous Bandgap Phononic-Photonic Crystal Slab,"In this paper we study and design quasi-2D optomechanical crystals,
waveguides, and resonant cavities formed from patterned slabs. Two-dimensional
periodicity allows for in-plane pseudo-bandgaps in frequency where resonant
optical and mechanical excitations localized to the slab are forbidden. By
tailoring the unit cell geometry, we show that it is possible to have a slab
crystal with simultaneous optical and mechanical pseudo-bandgaps, and for which
optical waveguiding is not compromised. We then use these crystals to design
optomechanical cavities in which strongly interacting, co-localized
photonic-phononic resonances occur. A resonant cavity structure formed by
perturbing a ""linear defect"" waveguide of optical and acoustic waves in a
silicon optomechanical crystal slab is shown to support an optical resonance at
wavelength 1.5 micron and a mechanical resonance of frequency 9.5 GHz. These
resonances, due to the simultaneous pseudo-bandgap of the waveguide structure,
are simulated to have optical and mechanical radiation-limited Q-factors
greater than 10^7. The optomechanical coupling of the optical and acoustic
resonances in this cavity due to radiation pressure is also studied, with a
quantum conversion rate, corresponding to the scattering rate of a single
cavity photon via a single cavity phonon, calculated to be 292 kHz.",1003.5265v2
2010-07-09,A SQUID based read-out of sub-attoNewton force sensor operating at millikelvin temperatures,"An increasing number of experiments require the use of ultrasensitive
nanomechanical resonators. Relevant examples are the investigation of quantum
effects in mechanical systems [1] or the detection of exceedingly small forces
as in Magnetic Resonance Force Microscopy (MRFM) [2]. The force sensitivity of
a mechanical resonator is typically limited by thermal fluctuations, which
calls for detection methods capable of operating at ultralow temperature.
Commonly used interferometric techniques, despite their excellent sensitivity,
may not be an optimal choice at millikelvin temperatures, because of unwanted
resonator heating caused by photon absorption. Although alternative detection
techniques based on microwave cavities [3] [4] [5] have shown to perform better
at ultralow temperature, these techniques still suffer from the fact that the
detection sensitivity decreases as the power input is decreased. Here, we
present a measurement approach based on the detection, through a
Superconducting Quantum Interference Device (SQUID), of the change of magnetic
flux induced in a coil by the motion of a magnetic particle attached to a
resonator. This detection scheme avoids direct heating of the resonator, as it
does not involve reflecting optical or microwave photons to the resonator. By
cooling an ultrasoft silicon resonator to 25 mK, we achieve a force noise of
0.5 aN in a 1 Hz bandwidth. We believe this detection technique can in
principle be used even at sub-millikelvin temperatures. Furthermore, it could
be used to improve the sensitivity of MRFM experiments, which aim at three
dimensional imaging at atomic resolution.",1007.1572v1
2010-07-18,Single-energy amplitudes for pion photoproduction in the first resonance region,"We consider multipole amplitudes for low-energy pion photoproduction,
constructed with minimal model dependence, at single energies. Comparisons with
fits to the full resonance region are made. Explanations are suggested for the
discrepancies and further experiments are motivated.",1007.3041v1
2010-07-27,Oscillating magnetic induction defined by neutron reflection,"The expressions are received for neutron reflection from the wave resonator
placed in an oscillating magnetic field. The conditions are defined for optimal
values of the neutron wave resonator and magnetic field parameters. Numerical
calculations which support theory conclusions are carried out for real systems.",1007.4666v1
2010-10-28,Study of loss in superconducting coplanar waveguide resonators,"Superconducting coplanar waveguide (SCPW) resonators have a wide range of
applications due to the combination of their planar geometry and high quality
factors relative to normal metals. However, their performance is sensitive to
both the details of their geometry and the materials and processes that are
used in their fabrication. In this paper, we study the dependence of SCPW
resonator performance on materials and geometry as a function of temperature
and excitation power. We measure quality factors greater than $2\times10^6$ at
high excitation power and $6\times10^5$ at a power comparable to that generated
by a single microwave photon circulating in the resonator. We examine the
limits to the high excitation power performance of the resonators and find it
to be consistent with a model of radiation loss. We further observe that while
in all cases the quality factors are degraded as the temperature and power are
reduced due to dielectric loss, the size of this effect is dependent on
resonator materials and geometry. Finally, we demonstrate that the dielectric
loss can be controlled in principle using a separate excitation near the
resonance frequencies of the resonator.",1010.6063v2
2011-01-04,Numerical Continuation of Bound and Resonant States of the Two Channel Schrödinger Equation,"Resonant solutions of the quantum Schr\""odinger equation occur at complex
energies where the S-matrix becomes singular. Knowledge of such resonances is
important in the study of the underlying physical system. Often the
Schr\""odinger equation is dependent on some parameter and one is interested in
following the path of the resonances in the complex energy plane as the
parameter changes. This is particularly true in coupled channel systems where
the resonant behavior is highly dependent on the strength of the channel
coupling, the energy separation of the channels and other factors. In previous
work it was shown that numerical continuation, a technique familiar in the
study of dynamical systems, can be brought to bear on the problem of following
the resonance path in one dimensional problems and multi-channel problems
without energy separation between the channels. A regularization can be defined
that eliminates coalescing poles and zeros that appear in the S-matrix at the
origin due to symmetries. Following the zeros of this regularized function then
traces the resonance path. In this work we show that this approach can be
extended to channels with energy separation, albeit limited to two channels.
The issue here is that the energy separation introduces branch cuts in the
complex energy domain that need to be eliminated with a so-called
uniformization. We demonstrate that the resulting approach is suitable for
investigating resonances in two-channel systems and provide an extensive
example.",1101.0692v2
2011-02-07,Using Kuiper Belt Binaries to Constrain Neptune's Migration History,"Approximately 10-20% of all Kuiper belt objects (KBOs) occupy mean-motion
resonances with Neptune. This dynamical configuration likely resulted from
resonance capture as Neptune migrated outward during the late stages of planet
formation. The details of Neptune's planetesimal-driven migration, including
its radial extent and the concurrent eccentricity evolution of the planet, are
the subject of considerable debate. Two qualitatively different proposals for
resonance capture have been proposed--migration-induced capture driven by
smooth outward evolution of Neptune's orbit and chaotic capture driven by
damping of the planet's eccentricity near its current semi-major axis. We
demonstrate that the distribution of comparable-mass, wide-separation binaries
occupying resonant orbits can differentiate between these two scenarios. If
migration-induced capture occurred, this fraction records information about the
formation locations of different populations of KBOs. Chaotic capture, in
contrast, randomizes the orbits of bodies as they are placed in resonance. In
particular, migration-induced capture produces the following signatures. The
2:1 resonance should contain a dynamically cold component, with inclinations
less than 5-10 degrees, having a binary fraction comparable to that among cold
classical KBOs. If the 3:2 resonance also hosts a cold component, its binary
fraction should be 20-30% lower than in the cold classical belt. Among cold 2:1
(and if present 3:2) KBOs, objects with eccentricities e < 0.2 should have a
binary fraction ~20% larger than those with e > 0.2. Searches for cold
components in the binary fractions of resonant KBOs are currently practical.
The additional migration-generated trends described here may be distinguished
with objects discovered by LSST. (Abstract abridged.)",1102.1430v1
2011-04-14,Resonances from meson-meson scattering in U(3) CHPT,"In this work, the complete one loop calculation of meson-meson scattering
amplitudes within U(3)\otimes U(3) chiral perturbation theory with explicit
resonance states is carried out for the first time. Partial waves are
unitarized from the perturbative calculation employing a non-perturbative
approach based on the N/D method. Once experimental data are reproduced in a
satisfactory way we then study the resonance properties, such as the pole
positions, corresponding residues and their N_C behaviors. The resulting N_C
dependence is the first one in the literature that takes into account the fact
that the \eta_1 becomes the ninth Goldstone boson in the chiral limit for large
N_C. Within this scheme the vector resonances studied, \rho(770), K^*(892) and
\phi(1020), follow an N_C trajectory in agreement with their standard \bar{q}q
interpretation. The scalars f_0(1370), a_0(1450) and K^*(1430) also have for
large N_C a \bar{q}q pole position trajectory and all of them tend to a bare
octet of scalar resonances around 1.4 GeV. The f_0(980) tends asymptotically to
the bare pole position of a singlet scalar resonance around 1 GeV. The \sigma,
\kappa and a_0(980) scalar resonances have a very different N_C behavior. The
case of the \sigma resonance is analyzed with special detail.",1104.2849v2
2011-05-09,Nanomechanical Resonators and Their Applications in Biological/Chemical Detection: Nanomechanics Principles,"Recent advances in nanotechnology have led to the development of
nano-electro-mechanical systems (NEMS) such as nanomechanical resonators, which
have recently received significant attention from the scientific community.
This has not only been for their capability for the label-free detection of
bio/chemical-molecules at single-molecule (or atomic) resolution for future
applications such as the early diagnostics of diseases such as cancer, but also
for their unprecedented ability to detect physical quantities such as molecular
weight, elastic stiffness, surface stress, and surface elastic stiffness for
adsorbed molecules on the surface. Most experimental works on resonator-based
molecular detection have been based on the principle that molecular adsorption
onto a resonator surface increases the effective mass, and consequently
decreases the resonant frequencies of the nanomechanical resonator. However,
this principle is insufficient to provide fundamental insights into
resonator-based molecular detection at the nanoscale; this is due to recently
proposed novel nanoscale detection principles including various effects such as
surface effects, nonlinear oscillations, coupled resonance, and stiffness
effects. Therefore, our objective in this review is to overview the current
attempts to understand the underlying mechanisms in nanoresonator-based
detection using physical models coupled to computational simulations and/or
experiments. Specifically, we will focus on issues of special relevance to the
dynamic behavior of nanoresonators and their applications in
biological/chemical detection. We additionally provide extensive discussion
regarding potentially fruitful future research directions coupling experiments
and simulations in order to develop a fundamental understanding of the basic
physical principles that govern NEMS and NEMS-based sensing applications.",1105.1785v1
2011-06-08,Phase disorder on laser beam combining in a Talbot resonator,"We study the role that phase disorder plays in the mode discrimination
characteristics of a Talbot resonator. Two cases considered here correspond to
a six-core and a twelve-core photonic crystal fiber.",1106.1575v1
2011-07-01,Absence of Resonances near Critical Line for CC Manifolds,"We find a resonance free region polynomially close to the critical line on
Conformally compact manifolds with polyhomogeneous metric.",1107.0091v2
2011-09-08,The resonance method for large character sums,"We consider the size of large character sums, proving new lower bounds for
the quantity $\Delta(N,q) = \sup_{\chi\neq \chi_0 mod q} |\sum_{n < N}
\chi(n)|$ for almost all ranges of $N$. The results are proven using the
resonance method and saddle point analysis.",1109.1786v1
2011-09-09,Resonances formed by pbar-p and decaying into pizero-pizero-eta for masses 1960 to 2410 MeV,"Data on pbar-b annihilation in flight into pizero-pizero-eta are presented
for nine beam momenta 600 to 1940 MeV/c. The strongest four intermediate states
are found to be f_2(1270)-eta, a_2(1320)-pi, sigma-eta and a_0(980)-pi. Partial
wave analysis is performed mainly to look for resonances formed by pbar-p and
decaying into pizero-pizero-eta through these intermediate states. There is
evidence for the following s-channel I = 0 resonances : two 4^{++} resonances
with mass and width (M,Gamma) at (2044, 208) MeV and (2320+-30, 220+-30) MeV;
three 2^{++} resonances at (2020+-50, 200+-70) MeV, (2240+-40, 170+-50) MeV and
(2370+-50, 320+-50) MeV; two 3^{++} resonances at (2000+-40, 250+-40) MeV and
(2280+-30, 210+-30) MeV; a 1^{++} resonance at (2340+-40, 340+-40) MeV; and two
2^{-+} resonances at (2040+-40, 190+-40) MeV and (2300+-40, 270+-40) MeV.",1109.2086v1
2011-10-28,Distribution of neutron resonance widths,"Recent data on neutron resonance widths indicate disagreement with the
Porter-Thomas distribution (PTD). I discuss the theoretical arguments for the
PTD, possible theoretical modifications, and I summarize the experimantal
evidence.",1110.6295v1
2012-09-15,Extraction of Meson Resonances from Three-pions Photo-production Reactions,"We have investigated the model dependence of meson resonance properties
extracted from the Dalitz-plot analysis of the three-pions photoproduction
reactions on the nucleon. Within a unitary model developed in Phys. Rev. D 84,
114019 (2011), we generate Dalitz-plot distributions as data to perform an
isobar model fit that is similar to most of the previous analyses of three-pion
production reactions. It is found that the resonance positions from the two
models agree well when both fit the data accurately, except for the resonance
poles near branch points. The residues of the resonant amplitudes extracted
from the two models and by the usual Breit-Wigner procedure agree well only for
the isolated resonances with narrow widths. For overlapping resonances, most of
the extracted residues could be drastically different. Our results suggest that
even with high precision data, the resonance extraction should be based on
models within which the amplitude parametrization is constrained by
three-particle unitarity condition.",1209.3402v2
2012-10-27,Dynamics on resonant clusters for the quintic non linear Schrödinger equation,"We construct solutions to the quintic nonlinear Schr\""odinger equation on the
circle with initial conditions supported on arbitrarily many different resonant
clusters. This is a sequel of a work of Beno\^it Gr\'ebert and the second
author.",1210.7291v1
2012-11-13,Dynamics of two-resonant biholomorphisms,"In this paper we study the existence of basins of attraction for germs of
2-resonant biholomorphisms of $\C^n$ fixing a point, that is germs such that
the eigenvalues of the differential at the fixed point have a 2 dimensional
family of resonances.",1211.3103v1
2013-01-13,Microelectromechanical Resonators for Radio Frequency Communication Applications,"Over the past few years, microelectromechanical system (MEMS) based on-chip
resonators have shown significant potential for sensing and high frequency
signal processing applications. This is due to their excellent features like
small size, large frequency-quality factor product, low power consumption, low
cost batch fabrication, and integrability with CMOS IC technology. Radio
frequency communication circuits like reference oscillators, filters, and
mixers based on such MEMS resonators can be utilized for meeting the increasing
count of RF components likely to be demanded by the next generation
multi-band/multi-mode wireless devices. MEMS resonators can provide a feasible
alternative to the present day well established quartz crystal technology that
is riddled with major drawbacks like relatively large size, high cost, and low
compatibility with IC chips. This article presents a survey of the developments
in this field of resonant MEMS structures with detailed enumeration on the
various micromechanical resonator types, modes of vibration, equivalent
mechanical and electrical models, materials and technologies used for
fabrication, and the application of the resonators for implementing oscillators
and filters. These are followed by a discussion on the challenges for RF MEMS
technology in comparison to quartz crystal technology; like high precision,
stability, reliability, need for hermetic packaging etc. which remain to be
addressed for enabling the inclusion of micromechanical resonators into
tomorrow's highly integrated communication systems.",1301.2780v1
2013-02-16,Resonances in the heavy symmetrical top with vibrating pivot,"In this work we consider a heavy symmetrical top whose pivot is subjected to
vertical and horizontal vibrations, and derive a resonance criterion when the
top is thrown off the stable position.",1302.3981v1
2013-03-08,A dark-field microscope for background-free detection of resonance fluorescence from single semiconductor quantum dots operating in a set-and-forget mode,"Optically active quantum dots, for instance self-assembled InGaAs quantum
dots, are potentially excellent single photon sources. The fidelity of the
single photons is much improved using resonant rather than non-resonant
excitation. With resonant excitation, the challenge is to distinguish between
resonance fluorescence and scattered laser light. We have met this challenge by
creating a polarization-based dark-field microscope to measure the resonance
fluorescence from a single quantum dot at low temperature. We achieve a
suppression of the scattered laser exceeding a factor of 10^7 and
background-free detection of resonance fluorescence. The same optical setup
operates over the entire quantum dot emission range 920-980 nm and also in high
magnetic fields. The major development is the outstanding long-term stability:
once the dark-field point has been established, the microscope operates for
days without alignment. The mechanical and optical design of the microscope is
presented, as well as exemplary resonance fluorescence spectroscopy results on
individual quantum dots to underline the microscope's excellent performance.",1303.2055v1
2013-04-08,Helicity amplitudes for photoexcitation of nucleon resonances off neutrons,"The helicity amplitudes $A^{1/2}_n$ and $A^{3/2}_n$ for the photoexcitation
of nucleon resonances off neutrons are determined in a multi-channel
partial-wave analysis.",1304.2177v1
2013-10-14,Non resonant transmission modelling with Statistical modal Energy distribution Analysis,"Statistical modal Energy distribution Analysis (SmEdA) can be used as an
alternative to Statistical Energy Analysis for describing subsystems with low
modal overlap. In its original form, SmEdA predicts the power flow exchanged
between the resonant modes of different subsystems. In the case of sound
transmission through a thin structure, it is well-known that the non resonant
response of the structure plays a significant role in transmission below the
critical frequency. In this paper, we present an extension of SmEdA that takes
into account the contributions of the non resonant modes of a thin structure.
The dual modal formulation (DMF) is used to describe the behaviour of two
acoustic cavities separated by a thin structure, with prior knowledge of the
modal basis of each subsystem. Condensation in the DMF equations is achieved on
the amplitudes of the non resonant modes and a new coupling scheme between the
resonant modes of the three subsystems is obtained after several
simplifications. We show that the contribution of the non resonant panel mode
results in coupling the cavity modes of stiffness type, characterised by the
mode shapes of both the cavities and the structure. Comparisons with reference
results demonstrate that the present approach can take into account the non
resonant contributions of the structure in the evaluation of the transmission
loss.",1310.3775v2
2013-11-18,Conditions for Sustained Orbital Resonances in Extreme Mass Ratio Inspirals,"We investigate the possibility of sustained orbital resonances in extreme
mass ratio inspirals. Using a near-identity averaging transformation, we reduce
the equations of motion for a particle moving in Kerr spacetime with self-force
corrections in the neighbourhood of a resonant geodesic to a one dimensional
equation for a particle moving in an effective potential. From this effective
equation we obtain the necessary and sufficient conditions that the self-force
needs to satisfy to allow inspiralling orbits to be captured in sustained
resonance. Along the way we also obtain the full non-linear expression for the
jump in the adiabatic constants of motion incurred as an inspiral transiently
evolves through a strong resonance to first-order in the mass ratio. Finally,
we find that if the resonance is strong enough to allow capture in sustained
resonance, only a small fraction (order of the square root of mass-ratio) of
all inspirals will indeed be captured. This makes observation of sustained
resonances in EMRIs -- if they exist -- very unlikely for space based
observatories like eLisa.",1311.4457v3
2014-02-04,Resonances and lower resolvent bounds,"We show how the presence of resonances close to the real axis implies
exponential lower bounds on the norm of the cut-off resolvent on the real axis.",1402.0604v1
2014-04-18,Resonance breaking due to dissipation in planar planetary systems,"We study the evolution of two planets around a star, in mean-motion resonance
and undergoing tidal effect. We derive an integrable analytical model of
mean-motion resonances of any order which reproduce the main features of the
resonant dynamics. Using this simplified model, we obtain a criterion showing
that depending on the balance of the tidal dissipation in both planets, their
final period ratio may stay at the resonant value, increase above, or decrease
below the resonant value.
  Applying this criterion to the two inner planets orbiting GJ163, we deduce
that the current period ratio (2.97) could be the outcome of dissipation in the
3:1 MMR provided that the innermost planet is gaseous (slow dissipation) while
the second one is rocky (faster dissipation). We perform N-body simulations
with tidal dissipation to confirm the results of our analytical model.
  We also apply our criterion on GJ581b, c (5:2 MMR) and reproduce the current
period ratio (2.4) if the inner planet is gaseous and the outer is rocky (as
for GJ163).
  Finally, we apply our model to the Kepler mission's statistics. We show that
the excess of planets pairs close to first order MMR but in external
circulation, i.e., with period ratios P_out/P_in > (p+1)/p for the resonance
(p+1):p, can be reproduced by tidal dissipation in the inner planet. There is
no need for any other dissipative mechanism, provided that these systems left
the resonance with non-negligible eccentricities.",1404.4861v1
2014-10-22,Model-Independent Production of a Top-Philic Resonance at the LHC,"We investigate the collider phenomenology of a color-singlet vector
resonance, which couples to the heaviest quarks, the top quarks, but very
weakly to the rest of the fermions in the Standard Model. We find that the
dominant production of such a resonance does not appear at the tree level -- it
rather occurs at the one-loop level in association with an extra jet.
Signatures like t anti-t plus jets readily emerge as a result of the subsequent
decay of the resonance into a pair of top quarks. Without the additional jet,
the resonance can still be produced off-shell, which gives a sizeable
contribution at low masses. The lower top quark multiplicity of the loop
induced resonance production facilitates its reconstruction as compared to the
tree level production that gives rise to more exotic signatures involving three
or even four top quarks in the final state. For all these cases, we discuss the
constraints on the resonance production stemming from recent experimental
measurements in the top quark sector. We find that the top-philic vector
resonance remains largely unconstrained for the majority of the parameter
space, although this will be scrutinized closely in the Run 2 phase of the LHC.",1410.6099v1
2014-11-03,Two-band description of resonant superfluidity in atomic Fermi gases,"Fermionic superfluidity in atomic Fermi gases across a Feshbach resonance is
normally described by the atom-molecule theory, which treats the closed channel
as a noninteracting point boson. In this work we present a theoretical
description of the resonant superfluidity in analogy to the two-band
superconductors. We employ the underlying two-channel scattering model of
Feshbach resonance where the closed channel is treated as a composite boson
with binding energy $\varepsilon_0$ and the resonance is triggered by the
microscopic interchannel coupling $U_{12}$. The binding energy $\varepsilon_0$
naturally serves as an energy scale of the system, which has been sent to
infinity in the atom-molecule theory. We show that the atom-molecule theory can
be viewed as a leading-order low-energy effective theory of the underlying
fermionic theory in the limit $\varepsilon_0\rightarrow\infty$ and
$U_{12}\rightarrow0$, while keeping the phenomenological atom-molecule coupling
finite. The resulting two-band description of the superfluid state is in
analogy to the BCS theory of two-band superconductors. In the dilute limit
$\varepsilon_0\rightarrow\infty$, the two-band description recovers precisely
the atom-molecule theory. The two-band theory provides a natural approach to
study the corrections because of a finite binding energy $\varepsilon_0$ in
realistic experimental systems. For broad and moderate resonances, the
correction is not important for current experimental densities. However, for
extremely narrow resonance, we find that the correction becomes significant.
The finite binding energy correction could be important for the stability of
homogeneous polarized superfluid against phase separation in imbalanced Fermi
gases across a narrow Feshbach resonance.",1411.0592v2
2014-11-14,Spin-orbit coupling and chaotic rotation for eccentric coorbital bodies,"The presence of a co-orbital companion induces the splitting of the well
known Keplerian spin-orbit resonances. It leads to chaotic rotation when those
resonances overlap.",1411.3950v1
2015-01-05,Instability of resonant invariant tori in Hamiltonian systems,"In this article, we consider the dynamics in a neighborhood of a
quasi-periodic torus which is invariant by a Hamiltonian flow, we discuss
several notions of stability and we prove several results of instability when
the frequency of the invariant torus is resonant.",1501.00759v1
2015-01-06,A Resonance Theorem for a Family of Translation Invariant Differentiation Bases,"A resonance theorem providing existence of functions that are counterexamples
for all members of a given family of translation invariant differentiation
bases is proved. Applications of the theorem to Zygmund problem on a choice of
coordinate axes are given.",1501.01230v1
2015-01-09,Three-body nature of $N^{\bf *}$ and $Δ^*$ resonances from sequential decay chains,"The $N\pi^0\pi^0$ decays of positive-parity $N^*$ and $\Delta^*$ resonances
at about 2\,GeV are studied at ELSA by photoproduction of two neutral pions off
protons. The data reveal clear evidence for several intermediate resonances:
$\Delta(1232)$, $N(1520){3/2^-}$, and $N(1680){5/2^+}$, with spin-parities
$J^P=3/2^+$, $3/2^-$, and $5/2^+$. The partial wave analysis (within the
Bonn-Gatchina approach) identifies $N(1440)1/2^+$ and the $N(\pi\pi)_{\rm
S-wave}$ (abbreviated as $N\sigma$ here) as further isobars, and assigns the
final states to the formation of nucleon and $\Delta$ resonances and to
non-resonant contributions. We observe the known $\Delta(1232)\pi$ decays of
$\Delta(1910)1/2^+$, $\Delta(1920)3/2^+$, $\Delta(1905)5/2^+$,
$\Delta(1950)7/2^+$, and of the corresponding spin-parity series in the nucleon
sector, $N(1880)1/2^+$, $N(1900)3/2^+$, $N(2000)5/2^+$, and $N(1990)7/2^+$. For
the nucleon resonances, these decay modes are reported here for the first time.
Further new decay modes proceed via $N(1440)1/2^+\pi$, $N(1520)3/2^-\pi$,
$N(1680)5/2^+\pi$, and $N\sigma$. The latter decay modes are observed in the
decay of $N^*$ resonances and at most weakly in $\Delta^*$ decays. It is argued
that these decay modes provide evidence for a 3-quark nature of $N^*$
resonances rather than a quark-diquark structure.",1501.02094v1
2015-01-17,Search for resonances and quantum black holes using dijet mass spectra in proton-proton collisions at sqrt(s) = 8 TeV,"A search for resonances and quantum black holes is performed using the dijet
mass spectra measured in proton-proton collisions at sqrt(s) = 8 TeV with the
CMS detector at the LHC. The data set corresponds to an integrated luminosity
of 19.7 inverse femtobarns. In a search for narrow resonances that couple to
quark-quark, quark-gluon, or gluon-gluon pairs, model-independent upper limits,
at 95% confidence level, are obtained on the production cross section of
resonances, with masses above 1.2 TeV. When interpreted in the context of
specific models the limits exclude: string resonances with masses below 5.0
TeV; excited quarks below 3.5 TeV; scalar diquarks below 4.7 TeV; W' bosons
below 1.9 TeV or between 2.0 and 2.2 TeV; Z' bosons below 1.7 TeV; and
Randall-Sundrum gravitons below 1.6 TeV. A separate search is conducted for
narrow resonances that decay to final states including b quarks. The first
exclusion limit is set for excited b quarks, with a lower mass limit between
1.2 and 1.6 TeV depending on their decay properties. Searches are also carried
out for wide resonances, assuming for the first time width-to-mass ratios up to
30%, and for quantum black holes with a range of model parameters. The wide
resonance search excludes axigluons and colorons with mass below 3.6 TeV, and
color-octet scalars with mass below 2.5 TeV. Lower bounds between 5.0 and 6.3
TeV are set on the masses of quantum black holes.",1501.04198v2
2015-03-03,Evolutionary outcomes for pairs of planets undergoing orbital migration and circularization: second order resonances and observed period ratios in Kepler's planetary systems,"In order to study the origin of the architectures of low mass planetary
systems, we perform numerical surveys of the evolution of pairs of coplanar
planets in the mass range $(1-4)\ \rmn{M}_{\oplus}.$ These evolve for up to
$2\times10^7 \rmn{yr}$ under a range of orbital migration torques and
circularization rates assumed to arise through interaction with a
protoplanetary disc. Near the inner disc boundary, significant variations of
viscosity, interaction with density waves or with the stellar magnetic field
could occur and halt migration, but allow ircularization to continue. This was
modelled by modifying the migration and circularization rates. Runs terminated
without an extended period of circularization in the absence of migration
torques gave rise to either a collision, or a system close to a resonance.
These were mostly first order with a few $\%$ terminating in second order
resonances. Both planetary eccentricities were small $< 0.1$ and all resonant
angles liberated. This type of survey produced only a limited range of period
ratios and cannot reproduce Kepler observations. When circularization alone
operates in the final stages, divergent migration occurs causing period ratios
to increase. Depending on its strength the whole period ratio range between $1$
and $2$ can be obtained. A few systems close to second order commensurabilities
also occur. In contrast to when arising through convergent migration, resonant
trapping does not occur and resonant angles circulate. Thus the behaviour of
the resonant angles may indicate the form of migration that led to near
resonance.",1503.00906v3
2015-04-20,Lindblad Zones: resonant eccentric orbits to aid bar and spiral formation in galaxy discs,"The apsidal precession frequency in a fixed gravitational potential increases
with the radial range of the orbit (eccentricity). Although the frequency
increase is modest it can have important implications for wave dynamics in
galaxy discs, which have not been previously explored in detail. One of the
most interesting consequences is that for a given pattern frequency, each
Lindblad resonance does not exist in isolation, but rather is the parent of a
continuous sequence of resonant radii, a Lindblad Zone, with each radius in
this zone characterized by a specific eccentricity. In the epicyclic
approximation the precession or epicyclic frequency does not depend on epicycle
size, and this phenomenon is not captured. A better approximation for eccentric
orbits is provided by p-ellipse curves (Struck 2006), which do exhibit this
effect. Here the p-ellipse approximation and precession-eccentricity relation
are used as tools for finding the resonant radii generated from various
Lindblad parent resonances. Simple, idealized examples, in flat rotation curve
and near solid-body discs, are used to show that ensembles of eccentric
resonant orbits excited in Lindblad Zones can provide a backbone for generating
a variety of (kinematic) bars and spiral waves. In cases balancing
radius-dependent circular frequencies and eccentricity-dependent precession, a
range of resonant orbits can maintain their form in the pattern frame, and do
not wind up. Eccentric resonance orbits require a strong perturbation to excite
them, and may be produced mostly in galaxy interactions or by strong internal
disturbances.",1504.05161v1
2015-05-07,Capture of Planets Into Mean Motion Resonances and the Origins of Extrasolar Orbital Architectures,"The early stages of dynamical evolution of planetary systems are often shaped
by dissipative processes that drive orbital migration. In multi-planet systems,
convergent amassing of orbits inevitably leads to encounters with rational
period ratios, which may result in establishment of mean motion resonances. The
success or failure of resonant capture yields exceedingly different subsequent
evolutions, and thus plays a central role in determining the ensuing orbital
architecture of planetary systems. In this work, we employ an integrable
Hamiltonian formalism for first order planetary resonances that allows both
secondary bodies to have finite masses and eccentricities, and construct a
comprehensive theory for resonant capture. Particularly, we derive conditions
under which orbital evolution lies within the adiabatic regime, and provide a
generalized criterion for guaranteed resonant locking as well as a procedure
for calculating capture probabilities when capture is not certain.
Subsequently, we utilize the developed analytical model to examine the
evolution of Jupiter and Saturn within the protosolar nebula, and investigate
the origins of the dominantly non-resonant orbital distribution of sub-Jovian
extrasolar planets. Our calculations show that the commonly observed extrasolar
orbital structure can be understood if planet pairs encounter mean motion
commensurabilities on slightly eccentric (e~0.02) orbits. Accordingly, we
speculate that resonant capture among low-mass planets is typically rendered
unsuccessful due to subtle axial asymmetries inherent to the global structure
of protoplanetary disks.",1505.01778v1
2015-05-24,Neutral pion photoproduction on the nucleon in a chiral quark model,"A chiral quark-model approach is adopted to study the $\gamma p\rightarrow
\pi^0p$ and $\gamma n\rightarrow \pi^0 n$ reactions. Good descriptions of the
total and differential cross sections and single-polarization observables are
obtained from the pion production threshold up to the second resonance region.
It is found that (i) the $n=0$ shell resonance $\Delta(1232)P_{33}$, the $n=1$
shell resonances $N(1535)S_{11}$ and $N(1520)D_{13}$, and the $n=2$ shell
resonance $N(1720)P_{13}$ play crucial roles in these two processes. They are
responsible for the first, second and third bump structures in the cross
sections, respectively. (ii) Furthermore, obvious evidences of $N(1650)S_{11}$
and $\Delta(1620)S_{31}$ are also found in the reactions. They notably affect
the cross sections and the polarization observables from the second resonance
region to the third resonance region. (iii) The $u$-channel background plays a
crucial role in the reactions. It has strong interferences with the $s$-channel
resonances. (iv) The $t$-channel background seems to be needed in the
reactions. Including the $t$-channel vector-meson exchange contribution, the
descriptions in the energy region $E_\gamma= 600\sim 900$ MeV are improved
significantly. The helicity amplitudes of the main resonances,
$\Delta(1232)P_{33}$, $N(1535)S_{11}$, $N(1520)D_{13}$, $N(1720)P_{13}$,
$N(1650)S_{11}$ and $\Delta(1620)S_{31}$, are extracted and compared with the
results from other groups.",1505.06396v2
2015-07-23,The Color Discriminant Variable and Scalar Diquarks at the LHC,"The LHC is actively searching for narrow dijet resonances corresponding to
physics beyond the Standard Model. Among the many resonances that have been
postulated (e.g., colored vectors, scalars, and fermions) one that would have a
particularly large production rate at the LHC would be a scalar diquark
produced in the s-channel via fusion of two valence quarks. In previous work,
we introduced a color discriminant variable that distinguishes among various
dijet resonances, drawing on measurements of the dijet resonance mass, total
decay width and production cross-section. Here, we show that this
model-independent method applies well to color-triplet and color-sextet scalar
diquarks, distinguishing them clearly from other candidate resonances. We also
introduce a more transparent theoretical formulation of the color discriminant
variable that highlights its relationship to the branching ratios of the
resonance into incoming and outgoing partons and to the properties of those
partons. While the original description of the color discriminant variable
remains convenient for phenomenological use upon discovery of a new resonance,
the new formulation makes it easier to predict the value of the variable for a
given class of resonance.",1507.06676v2
2015-08-04,General classical and quantum-mechanical description of magnetic resonance: An application to electric-dipole-moment experiments,"A general theoretical description of a magnetic resonance is presented. This
description is necessary for a detailed analysis of spin dynamics in
electric-dipole-moment experiments in storage rings. General formulas
describing a behavior of all components of the polarization vector at the
magnetic resonance are obtained for an arbitrary initial polarization. These
formulas are exact on condition that the nonresonance rotating field is
neglected. The spin dynamics is also calculated at frequencies far from
resonance with allowance for both rotating fields. A general quantum-mechanical
analysis of the spin evolution at the magnetic resonance is fulfilled and the
full agreement between the classical and quantum-mechanical approaches is
shown. Quasimagnetic resonances for particles and nuclei moving in
noncontinuous perturbing fields of accelerators and storage rings are
considered. Distinguishing features of quasimagnetic resonances in storage ring
electric-dipole-moment experiments are investigated in detail. The exact
formulas for the effect caused by the electric dipole moment are derived. The
difference between the resonance effects conditioned by the rf electric-field
flipper and the rf Wien filter is found and is calculated for the first time.
The existence of this difference is crucial for the establishment of a consent
between analytical derivations and computer simulations and for checking spin
tracking programs. Main systematical errors are considered.",1508.00742v3
2015-09-15,Resonance vibration of impact oscillator with biharmonic excitation,"We consider a damped impact oscillator subject to the action of a biharmonic
force. The conditions for the existence and stability of almost periodic
resonance solutions are investigated.",1509.05381v1
2016-02-06,Photon-phonon parametric oscillation induced by the quadratic coupling in an optomechanical resonator,"A direct photon-phonon parametric effect of the quadratic coupling on the
mean-field dynamics of an optomechanical resonator in the large-scale-movement
regime is found and investigated. Under a weak pumping power, the mechanical
resonator damps to steady state with a nonlinear static response sensitively
modified by the quadratic coupling. When the driving powerincreases beyond the
static energy balance, the steady states lose their stabilities via Hopf
bifurcations and the resonator produces stable self-sustained
oscillation(limit-circle behavior) of discrete energies with step-like
amplitudes due to the parametric effect of the quadratic coupling, which can be
understood roughly by the power balance between gain and loss on the resonator.
A further increase of the pumping power can induce chaotic dynamic of the
resonator via a typical routine of period-doubling bifurcation but which can be
stabilized by the parametric effect through an inversion bifurcation process
back to limit-circle states. The bifurcation-to-inverse-bifurcation transitions
are numerically verified by the maximal Lyapunov exponents of the dynamics and
which indicate an efficient way to suppress the chaotic behavior of the
optomechanical resonator by the quadratic coupling. Furthermore, the parametric
effect of the quadratic coupling on the dynamic transitions of an
optomechanical resonator can be conveniently detected or traced by the output
power spectrum of the cavity field.",1602.02221v3
2016-03-09,1/n Expansion of Resonant States,"We present a general analytic expansion in powers of $1/n$ of the resonant
states of quantum-mechanical systems, where $n=1,2,3,\cdots$ is the excitation
number. Explicit formulas are obtained for some potential barrier models.",1603.02857v1
2016-03-12,Magnetic Resonance Force Detection using a Membrane Resonator,"The availability of compact, low-cost magnetic resonance imaging instruments
would further broaden the substantial impact of this technology. We report
highly sensitive detection of magnetic resonance using low-stress silicon
nitride (SiN$_x$) membranes. We use these membranes as low-loss, high-frequency
mechanical oscillators and find they are able to mechanically detect
spin-dependent forces with high sensitivity enabling ultrasensitive magnetic
resonance detection. The high force detection sensitivity stems from their high
mechanical quality factor $Q\sim10^6$ combined with the low mass of the
resonator. We use this excellent mechanical force sensitivity to detect the
electron spin magnetic resonance using a SiN$_x$ membrane as a force detector.
The demonstrated force sensitivity at 300 K is 4 fN/$\sqrt{\mathrm{Hz}}$,
indicating a potential low temperature (4 K) sensitivity of 25
aN/$\sqrt{\mathrm{Hz}}$. Given their sensitivity, robust construction, large
surface area and low cost, SiN$_x$ membranes can potentially serve as the
central component of a compact room-temperature ESR and NMR instrument that has
superior spatial resolution to conventional approaches.",1603.03953v2
2016-03-24,The theory of secondary resonances in the spin-orbit problem,"We study the resonant dynamics in a simple one degree of freedom, time
dependent Hamiltonian model describing spin-orbit interactions. The equations
of motion admit periodic solutions associated with resonant motions, the most
important being the synchronous one in which most evolved satellites of the
Solar system, including the Moon, are observed. Such primary resonances can be
surrounded by a chain of smaller islands which one refers to as secondary
resonances. Here, we propose a novel canonical normalization procedure allowing
to obtain a higher order normal form, by which we obtain analytical results on
the stability of the primary resonances as well as on the bifurcation
thresholds of the secondary resonances. The procedure makes use of the
expansion in a parameter, called the detuning, measuring the shift from the
exact secondary resonance. Also, we implement the so-called `book-keeping'
method, i.e., the introduction of a suitable separation of the terms in orders
of smallness in the normal form construction, which deals simultaneously with
all the small parameters of the problem. Our analytical computation of the
bifurcation curves is in excellent agreement with the results obtained by a
numerical integration of the equations of motion, thus providing relevant
information on the parameter regions where satellites can be found in a stable
configuration.",1603.07760v1
2016-04-27,Chaotic Diffusion in the Gliese-876 Planetary System,"Chaotic diffusion is supposed to be responsible for orbital instabilities in
planetary systems after the dissipation of the protoplanetary disk, and a
natural consequence of irregular motion. In this paper we show that resonant
multi-planetary systems, despite being highly chaotic, not necessarily exhibit
significant diffusion in phase space, and may still survive virtually unchanged
over timescales comparable to their age.Using the GJ-876 system as an example,
we analyze the chaotic diffusion of the outermost (and less massive) planet. We
construct a set of stability maps in the surrounding regions of the Laplace
resonance. We numerically integrate ensembles of close initial conditions,
compute Poincar\'e maps and estimate the chaotic diffusion present in this
system. Our results show that, the Laplace resonance contains two different
regions: an inner domain characterized by low chaoticity and slow diffusion,
and an outer one displaying larger values of dynamical indicators. In the outer
resonant domain, the stochastic borders of the Laplace resonance seem to
prevent the complete destruction of the system. We characterize the diffusion
for small ensembles along the parameters of the outermost planet. Finally, we
perform a stability analysis of the inherent chaotic, albeit stable Laplace
resonance, by linking the behavior of the resonant variables of the
configurations to the different sub-structures inside the three-body resonance.",1604.07901v1
2016-04-29,Search for narrow resonances in dijet final states at sqrt(s) = 8 TeV with the novel CMS technique of data scouting,"A search for narrow resonances decaying into dijet final states is performed
on data from proton-proton collisions at a center-of-mass energy of 8 TeV,
corresponding to an integrated luminosity of 18.8 inverse femtobarns. The data
were collected with the CMS detector using a novel technique called data
scouting, in which the information associated with these selected events is
much reduced, permitting collection of larger data samples. This technique
enables CMS to record events containing jets at a rate of 1 kHz, by collecting
the data from the high-level-trigger system. In this way, the sensitivity to
low-mass resonances is increased significantly, allowing previously
inaccessible couplings of new resonances to quarks and gluons to be probed. The
resulting dijet mass distribution yields no evidence of narrow resonances.
Upper limits are presented on the resonance cross sections as a function of
mass, and compared with a variety of models predicting narrow resonances. The
limits are translated into upper limits on the coupling of a leptophobic
resonance Z'[B] to quarks, improving on the results obtained by previous
experiments for the mass range from 500 to 800 GeV.",1604.08907v2
2016-06-16,Calculating rotating hydrodynamic and magneto-hydrodynamic waves to understand magnetic effects on dynamical tides,"For understanding magnetic effects on dynamical tides, we study the rotating
magneto-hydrodynamic (MHD) flow driven by harmonic forcing. The linear
responses are analytically derived in a periodic box under the local WKB
approximation. Both the kinetic and Ohmic dissipations at the resonant
frequencies are calculated and the various parameters are investigated.
Although magnetic pressure may be negligible compared to thermal pressure,
magnetic field can be important for the first-order perturbation, e.g.
dynamical tides. It is found that magnetic field splits the resonant frequency,
namely the rotating hydrodynamic flow has only one resonant frequency but the
rotating MHD flow has two, one positive and the other negative. In the weak
field regime the dissipations are asymmetric around the two resonant
frequencies and this asymmetry is more striking with a weaker magnetic field.
It is also found that both the kinetic and Ohmic dissipations at the resonant
frequencies are inversely proportional to the Ekman number and the square of
wavenumber. The dissipation at the resonant frequency on small scales is almost
equal to the dissipation at the non-resonant frequencies, namely the resonance
takes its effect on the dissipation at intermediate length scales. Moreover,
the waves with phase propagation perpendicular to magnetic field are much more
damped. It is also interesting to find that the frequency-averaged dissipation
is constant. This result suggests that in compact objects magnetic effects on
tidal dissipation should be considered.",1606.06232v1
2016-07-18,Dielectric tuning and coupling of whispering gallery modes using an anisotropic prism,"Optical whispering gallery mode (WGM) resonators are a powerful and versatile
tool used in many branches of science. Fine tuning of the central frequency and
line width of individual resonances is however desirable in a number of
applications including frequency conversion, optical communications and
efficient light-matter coupling. To this end we present a detailed theoretical
analysis of dielectric tuning of WGMs supported in axisymmetric resonators.
Using the Bethe-Schwinger equation and adopting an angular spectrum field
representation we study the resonance shift and mode broadening of high $Q$
WGMs when a planar dielectric substrate is brought close to the resonator.
Particular focus is given to use of a uniaxial substrate with an arbitrarily
aligned optic axis. Competing red and blue resonance shifts ($\sim 30$ MHz),
deriving from generation of a near field material polarisation and back action
from the radiation continuum respectively, are found. Anomalous resonance
shifts can hence be observed depending on the substrate material, whereas mode
broadening on the order of $\sim 50$ MHz can also be simply realised.
Furthermore, polarisation selective coupling with extinction ratios of $> 10^4$
can be achieved when the resonator and substrate are of the same composition
and their optic axes are chosen correctly. Double refraction and properties of
out-coupled beams are also discussed.",1607.05098v1
2016-09-17,How to Discover the Rogers--Ramunujan Identities,"We examine a method to conjecture two very famous identities that were
conjectured by Ramanujan, and later found to be known to Rogers.",1609.05325v1
2016-09-19,High quality-factor mechanical resonators based on WSe2 monolayers,"Suspended monolayer transition metal-dichalcogenides (TMD) are membranes that
combine ultra-low mass and exceptional optical properties, making them
intriguing materials for opto-mechanical applications. However, the low
measured quality factor of TMD resonators has been a roadblock so far. Here, we
report an ultrasensitive optical readout of monolayer TMD resonators that
allows us to reveal their mechanical properties at cryogenic temperatures. We
find that the quality factor of monolayer WSe2 resonators greatly increases
below room temperature, reaching values as high as 1.6E^4 at liquid nitrogen
temperature and 4.7E^4 at liquid helium temperature. This surpasses the quality
factor of monolayer graphene resonators with similar surface areas. Upon
cooling the resonator, the resonant frequency increases significantly due to
the thermal contraction of the WSe2 lattice. These measurements allow us to
experimentally study the thermal expansion coefficient of WSe2 monolayers for
the first time. High Q-factors are also found in resonators based on MoS2 and
MoSe2 monolayers. The high quality-factor found in this work opens new
possibilities for coupling mechanical vibrational states to two-dimensional
excitons, valley pseudospins, and single quantum emitters, and for quantum
opto-mechanical experiments based on the Casimir interaction.",1609.05620v1
2016-10-24,Magnetoplasmon Fano resonance in Bose-Fermi mixtures,"We investigate theoretically the magnetoplasmon (cyclotron) resonance in a
hybrid system consisting of spatially separated two-dimensional layers of
electron and dipolar exciton gases coupled via the Coulomb forces. We study the
dynamics of this system under the action of weak alternating external
electromagnetic field in the presence of uniform magnetic field, perpendicular
to the layers. We reveal that the electromagnetic power absorption exhibits a
double-resonance spectrum. We show that the first resonance is associated with
the conventional well-studied magnetoplasmon excitations of the electron gas
and it has a standard Lorentzian shape, whereas the second resonance is a
peculiarity attributed to the Bose-condensed exciton gas. Further, we
explicitly demonstrate that the spectrum of the system exhibits an asymmetric
Fano-type profile, where the excitonic peak is extremely narrow in comparison
with the magnetoplasmon one. We show that the shape of the resonance and the
position of the peaks depends on the magnitude of the applied magnetic field,
exciton condensate density and exciton-impurity scattering time. In particular,
the Fano profile turns into a Lorentzian shape with decreasing exciton-impurity
scattering time and the position of the plasmon-associated resonance is mainly
sensitive and determined by the magnetic field strength, whereas the
exciton-condensate peak position is determined by exciton condensate density.
It opens the experimental possibility to determine the latter quantity in
cyclotron resonance experiment.",1610.07316v3
2017-02-07,Mean motion resonances at high eccentricities: the 2:1 and the 3:2 interior resonances,"Mean motion resonances [MMRs] play an important role in the formation and
evolution of planetary systems and have significantly influenced the orbital
properties and distribution of planets and minor planets in the solar system as
well as exo-planetary systems. Most previous theoretical analyses have focused
on the low-to-moderate eccentricity regime, but with new discoveries of high
eccentricity resonant minor planets and even exoplanets, there is increasing
motivation to examine MMRs in the high eccentricity regime. Here we report on a
study of the high eccentricity regime of MMRs in the circular planar restricted
three-body problem. Non-perturbative numerical analyses of the 2:1 and the 3:2
interior resonances are carried out for a wide range of secondary-to-primary
mass ratio, and for a wide range of eccentricity of the test particle. The
surface-of-section technique is used to study the phase space structure near
resonances. We identify transitions in phase space at certain critical
eccentricities related to the geometry of resonant orbits; new stable libration
zones appear at high eccentricity at libration centers shifted from those at
low eccentricities. We present novel results on the mass and eccentricity
dependence of the resonance libration centers and their widths in semi-major
axis. Our results show that MMRs have sizable libration zones at high
eccentricities, comparable to those at lower eccentricities.",1702.02137v1
2017-02-07,Possible hundredfold enhancement in the direct magnetic coupling of a single atomic spin to a circuit resonator,"We report on the challenges and limitations of direct coupling of the
magnetic field from a circuit resonator to an electron spin bound to a donor
potential. We propose a device consisting of a trilayer lumped-element
superconducting resonator and a single donor implanted in enriched $^{28}$Si.
The resonator impedance is significantly smaller than the practically
achievable limit using prevalent coplanar resonators. Furthermore, the
resonator includes a nano-scale spiral inductor to spatially focus the magnetic
field from the photons at the location of the implanted donor. The design
promises approximately two orders of magnitude increase in the local magnetic
field, and thus the spin to photon coupling rate $g$, compared to the estimated
coupling rate to the magnetic field of coplanar transmission-line resonators.
We show that by using niobium (aluminum) as the resonator's superconductor and
a single phosphorous (bismuth) atom as the donor, a coupling rate of
$g/2\pi$=0.24 MHz (0.39 MHz) can be achieved in the single photon regime. For
this hybrid cavity quantum electrodynamic system, such enhancement in $g$ is
sufficient to enter the strong coupling regime.",1702.02210v3
2017-08-17,"Search for massive resonances decaying into WW, WZ, ZZ, qW, and qZ with dijet final states at $\sqrt{s} =$ 13 TeV","Results are presented from a search in the dijet final state for new massive
narrow resonances decaying to pairs of W and Z bosons or to a W/Z boson and a
quark. Results are based on data recorded in proton-proton collisions at
$\sqrt{s} =$ 13 TeV with the CMS detector at the CERN LHC. The data correspond
to an integrated luminosity of 35.9 fb$^{-1}$. The mass range investigated
extends upwards from 1.2 TeV. No excess is observed above the estimated
standard model background and limits are set at 95% confidence level on cross
sections, which are interpreted in terms of various models that predict
gravitons, heavy spin-1 bosons, and excited quarks. In a heavy vector triplet
model, W' and Z' resonances, with masses below 3.6 and 2.7 TeV, respectively,
and spin-1 resonances with degenerate masses below 3.8 TeV are excluded at 95%
confidence level. In the case of a singlet W' resonance masses between 3.3 and
3.6 TeV can be excluded additionally. Similarly, excited quark resonances, q*,
decaying to qW and qZ with masses less than 5.0 and 4.7 TeV, respectively, are
excluded. In a narrow-width bulk graviton model, upper limits are set on cross
sections ranging from 0.6 fb for high resonance masses of 3.6 TeV, to 36.0 fb
for low resonance masses of 1.3 TeV.",1708.05379v2
2018-02-08,Non-resonant tori in symplectic twist maps without conjugate points,"We study the dynamics of a symplectic twist map without conjugate points. We
show that in a neighborhood of a totally periodic Lagrangian manifold, there
exists a large family of invariant Lagrangian tori on which the twist map is
conjugated to a translation of non-resonant vector.",1802.02858v1
2018-02-14,Magnetic Field Dependent Microwave Losses in Superconducting Niobium Microstrip Resonators,"We describe an experimental protocol to characterize magnetic field dependent
microwave losses in superconducting niobium microstrip resonators. Our approach
provides a unified view that covers two well-known magnetic field dependent
loss mechanisms: quasiparticle generation and vortex motion. We find that
quasiparticle generation is the dominant loss mechanism for parallel magnetic
fields. For perpendicular fields, the dominant loss mechanism is vortex motion
or switches from quasiparticle generation to vortex motion, depending on
cooling procedures. In particular, we introduce a plot of the quality factor
versus the resonance frequency as a general method for identifying the dominant
loss mechanism. We calculate the expected resonance frequency and the quality
factor as a function of the magnetic field by modeling the complex resistivity.
Key parameters characterizing microwave loss are estimated from comparisons of
the observed and expected resonator properties. Based on these key parameters,
we find a niobium resonator whose thickness is similar to its penetration depth
is the best choice for X-band electron spin resonance applications. Finally, we
detect partial release of the Meissner current at the vortex penetration field,
suggesting that the interaction between vortices and the Meissner current near
the edges is essential to understand the magnetic field dependence of the
resonator properties.",1802.05183v3
2019-05-06,"Gross, intermediate and fine structure of nuclear giant resonances: Evidence for doorway states","We review the phenomenon of fine structure of nuclear giant resonances and
its relation to different resonance decay mechanisms. Wavelet analysis of the
experimental spectra provides quantitative information on the fine structure in
terms of characteristic scales. A comparable analysis of resonance strength
distributions from microscopic approaches incorporating one or several of the
resonance decay mechanisms allows conclusions on the source of the fine
structure. For the isoscalar giant quadrupole resonance (ISGQR), spreading
through the first step of the doorway mechanism, i.e.\ coupling between one
particle-one hole ($1p1h$) and two particle-two hole ($2p2h$) states is
identified as the relevant mechanism. In heavy nuclei it is dominated by
coupling to low-lying surface vibrations, while in lighter nuclei stochastic
coupling becomes increasingly important. The fine structure observed for the
isovector giant dipole resonance (IVGDR) arises mainly from the fragmentation
of the $1p1h$ strength (Landau damping), although some indications for the
relevance of the spreading width are also found.",1905.02579v1
2019-05-16,Influence of clamp-widening on the quality factor of nanomechanical silicon nitride resonators,"Nanomechanical resonators based on strained silicon nitride (Si$_3$N$_4$)
have received a large amount of attention in fields such as sensing and quantum
optomechanics due to their exceptionally high quality factors ($Q$s).
Room-temperature $Q$s approaching 1 billion are now in reach by means of
phononic crystals (soft-clamping) and strain engineering. Despite great
progress in enhancing $Q$s, difficulties in fabrication of soft-clamped samples
limits their implementation into actual devices. An alternative means of
achieving ultra-high $Q$s was shown using trampoline resonators with engineered
clamps, which serves to localize the stress to the center of the resonator,
while minimizing stress at the clamping. The effectiveness of this approach has
since come into question from recent studies employing string resonators with
clamp-tapering. Here, we investigate this idea using nanomechanical string
resonators with engineered clampings similar to those presented for
trampolines. Importantly, the effect of orienting the strings diagonally or
perpendicularly with respect to the silicon frame is investigated. It is found
that increasing the clamp width for diagonal strings slightly increases the
$Q$s of the fundamental out-of-plane mode at small radii, while perpendicular
strings only deteriorate with increasing clamp width. Measured $Q$s agree well
with finite element method simulations even for higher-order resonances. The
small increase cannot account for previously reported $Q$s of trampoline
resonators. Instead, we propose the effect to be intrinsic and related to
surface and radiation losses.",1905.06730v2
2020-07-27,Trojan horse method as surrogate indirect approach to study resonant reactions in nuclear astrophysics,"We review the Trojan horse method and its applications to resonant reactions
in nuclear astrophysics.",2007.13331v2
2013-08-13,Dirac dynamical resonance states around Schwarzschild black holes,"Recently, a novel kind of scalar wigs around Schwarzschild black
holes---scalar dynamical resonance states were introduced in [Phys. Rev. D 84,
083008 (2011)] and [Phys. Rev. Lett. 109, 081102 (2012)]. In this paper, we
investigate the existence and evolution of Dirac dynamical resonance states.
First we look for stationary resonance states of a Dirac field around a
Schwarzchild black hole by using the Schr\""{o}dinger-like equations reduced
from the Dirac equation in Schwarzschild spacetime. Then Dirac
pseudo-stationary configurations are constructed from the stationary resonance
states. We use these configurations as initial data and investigate their
numerical evolutions and energy decay. These dynamical solutions are the
so-called ""Dirac dynamical resonance states"". It is found that the energy of
the Dirac dynamical resonance states shows an exponential decay. The decay rate
of energy is affected by the resonant frequency, the mass of Dirac field, the
total angular momentum, and the spin-orbit interaction. In particular, for
ultra-light Dirac field, the corresponding particles can stay around a
Schwarzschild black hole for a very long time, even for cosmological
time-scales.",1308.2863v3
2017-01-26,An Analytic Criterion for Turbulent Disruption of Planetary Resonances,"Mean motion commensurabilities in multi-planet systems are an expected
outcome of protoplanetary disk-driven migration, and their relative dearth in
the observational data presents an important challenge to current models of
planet formation and dynamical evolution. One natural mechanism that can lead
to the dissolution of commensurabilities is stochastic orbital forcing, induced
by turbulent density fluctuations within the nebula. While this process is
qualitatively promising, the conditions under which mean motion resonances can
be broken are not well understood. In this work, we derive a simple analytic
criterion that elucidates the relationship among the physical parameters of the
system, and find the conditions necessary to drive planets out of resonance.
Subsequently, we confirm our findings with numerical integrations carried out
in the perturbative regime, as well as direct N-body simulations. Our
calculations suggest that turbulent resonance disruption depends most
sensitively on the planet-star mass ratio. Specifically, for a disk with
properties comparable to the early solar nebula with $\alpha=0.01$, only planet
pairs with cumulative mass ratios smaller than
$(m_1+m_2)/M\lesssim10^{-5}\sim3M_{\oplus}/M_{\odot}$ are susceptible to
breaking resonance at semi-major axis of order $a\sim0.1\,$AU. Although
turbulence can sometimes compromise resonant pairs, an additional mechanism
(such as suppression of resonance capture probability through disk
eccentricity) is required to adequately explain the largely non-resonant
orbital architectures of extrasolar planetary systems.",1701.07849v1
2017-04-11,Frequency Response and Resonance of Elastic Hele-Shaw Cells with Application to Mechanical Filters,"We study steady-state oscillations of an elastic Hele-Shaw cell excited by
traveling pressure waves over its upper surface. The fluid within the cell is
bounded by two asymmetric elastic sheets which are connected to a rigid surface
via distributed springs and modeled by the linearized plate theory. Modal
analysis yields the frequency response of the configuration as a function of
three parameters: the fluidic Womersley number and two ratios of elastic stress
to viscous pressure for each of the sheets. These ratios, analogous to the
Capillary number, combine the effects of fluid viscosity and the sheets
inertia, bending and tension. The resonance frequencies of the configuration
include the resonance frequency of the upper sheet, and the resonance frequency
of both sheets with a constraint of constant gap. Near the resonance frequency
of the upper sheet, the fluid pressure is identical in amplitude and phase to
the external excitation. For configurations where both sheets are near
resonance, small changes in frequency yield significant modification of the
fluidic pressure. In addition, a new resonance frequency is observed, related
to the interaction between motion of fluid parallel to the elastic sheets and
relative elastic displacements of the sheets. The ratio of the amplitude of the
fluidic pressure to the external pressure is presented vs. frequency for
several characteristic solid and fluid properties, yielding a bandpass filter
behaviour. For configurations with a rigid lower surface the pressure ratio is
unity at the passband, while for two elastic sheets pressure amplification or
reduction occurs near the resonance frequencies. The results presented here may
allow to utilize elastic Hele-Shaw configurations as protective surfaces and
mechanical filters.",1704.03175v1
2008-07-17,Chaotic Diffusion of Resonant Kuiper Belt Objects,"We carried out extensive numerical orbit integrations to probe the long-term
chaotic dynamics of the two strongest mean motion resonances of Neptune in the
Kuiper belt, the 3:2 (Plutinos) and 2:1 (Twotinos). Our primary results include
a computation of the relative volumes of phase space characterized by large-
and small-resonance libration amplitudes, and maps of resonance stability
measured by mean chaotic diffusion rate. We find that Neptune's 2:1 resonance
has weaker overall long-term stability than the 3:2 -- only ~15% of Twotinos
are projected to survive for 4 Gyr, compared to ~27% of Plutinos, based on an
extrapolation from our 1-Gyr integrations. We find that Pluto has only a modest
effect, causing a ~4% decrease in the Plutino population that survives to 4
Gyr. Given current observational estimates, and assuming an initial
distribution of particles proportional to the local phase space volume in the
resonance, we conclude that the primordial populations of Plutinos and Twotinos
formerly made up more than half the population of the classical and resonant
Kuiper Belt. We also conclude that Twotinos were originally nearly as numerous
as Plutinos; this is consistent with predictions from early models of smooth
giant planet migration and resonance sweeping of the Kuiper Belt, and provides
a useful constraint for more detailed models.",0807.2835v3
2012-01-13,Development for Hardware for Programming of Spatial Magnetic Field Distributions in Nuclear Magnetic Resonance and Magnetic Resonance Imaging,"The proposal of a project aimed on a design of hardware for programming 3D
Magnetic Field shapes over sample volume in NMR and MRI is described.",1201.2764v1
2013-09-05,Quantum Materials: Shape Resonances in Superstripes,"The significance of stripes in certain high-temperature superconductors has
been hotly debated for decades. Now a consensus is emerging that there may, in
fact, be two networks of different stripes in which shape resonances play a key
role in the superconductivity.",1309.1293v1
2014-05-21,Magnetic resonance in human brain examinations. A brief outline of the techniques,"A brief description of the magnetic resonance imaging and related advanced
techniques like diffusion, perfusion and spectroscopy in the human brain
examinations is given.",1405.5331v1
2014-06-04,A numerical study of vector resonant relaxation,"Stars bound to a supermassive black hole interact gravitationally. Persistent
torques acting between stellar orbits lead to the rapid resonant relaxation of
the orbital orientation vectors (""vector"" resonant relaxation) and slower
relaxation of the eccentricities (""scalar"" resonant relaxation), both at rates
much faster than two-body or non-resonant relaxation. We describe a new
parallel symplectic integrator, N-ring, which follows the dynamical evolution
of a cluster of N stars through vector resonant relaxation, by averaging the
pairwise interactions over the orbital period and periapsis-precession
timescale. We use N-ring to follow the evolution of clusters containing over
10^4 stars for tens of relaxation times. Among other results, we find that the
evolution is dominated by torques among stars with radially overlapping orbits,
and that resonant relaxation can be modelled as a random walk of the orbit
normals on the sphere, with angular step size ranging from 0.5-1 radian. The
relaxation rate in a cluster with a fixed number of stars is proportional to
the RMS mass of the stars. The RMS torque generated by the cluster stars is
reduced below the torque between Kepler orbits due to apsidal precession and
declines weakly with the eccentricity of the perturbed orbit. However since the
angular momentum of an orbit also decreases with eccentricity, the relaxation
rate is approximately eccentricity-independent for e<0.7 and grows rapidly with
eccentricity for e>0.8. We quantify the relaxation using the autocorrelation
function of the spherical multipole moments; this decays exponentially and the
e-folding time may be identified with the vector resonant relaxation timescale.",1406.1178v3
2014-06-08,Distinguishing Flavor Non-universal Colorons from Z' Bosons at the LHC,"Electrically-neutral massive color-singlet and color-octet vector bosons,
which are often predicted in Beyond the Standard Model theories, have the
potential to be discovered as dijet resonances at the LHC. A color-singlet
resonance that has leptophobic couplings needs further investigation to be
distinguished from a color-octet one. In previous work, we introduced a method
for discriminating between the two kinds of resonances when their couplings are
flavor-universal, using measurements of the dijet resonance mass, total decay
width and production cross-section. Here, we describe an extension of that
method to cover a more general scenario, in which the vector resonances could
have flavor non-universal couplings; essentially, we incorporate measurements
of the heavy-flavor decays of the resonance into the method. We present our
analysis in a model-independent manner for a dijet resonance with mass 2.5-6.0
TeV at the LHC with $\sqrt{s}=14$ TeV and integrated luminosities 30, 100, 300
and 1000 ${\rm fb}^{-1}$, and show that the measurements of the heavy-flavor
decays should allow conclusive identification of the vector boson. Note that
our method is generally applicable even for a Z' boson with non-Standard
invisible decays. We include an appendix of results for various resonance
couplings and masses to illustrate how well each observable must be measured to
distinguish colorons from Z' bosons.",1406.2003v2
2014-06-09,Evolution of eccentricity and orbital inclination of migrating planets in 2:1 mean motion resonance,"We determine, analytically and numerically, the conditions needed for a
system of two migrating planets trapped in a 2:1 mean motion resonance to enter
an inclination-type resonance. We provide an expression for the asymptotic
equilibrium value that the eccentricity $e_{\rm i}$ of the inner planet reaches
under the combined effects of migration and eccentricity damping. We also show
that, for a ratio $q$ of inner to outer masses below unity, $e_{\rm i}$ has to
pass through a value $e_{\rm i,res}$ of order 0.3 for the system to enter an
inclination-type resonance. Numerically, we confirm that such a resonance may
also be excited at another, larger, value $e_{\rm i, res} \simeq 0.6$, as found
by previous authors. A necessary condition for onset of an inclination-type
resonance is that the asymptotic equilibrium value of $e_{\rm i}$ is larger
than $e_{\rm i,res}$. We find that, for $q \le 1$, the system cannot enter an
inclination-type resonance if the ratio of eccentricity to semimajor axis
damping timescales $t_e/t_a$ is smaller than 0.2. This result still holds if
only the eccentricity of the outer planet is damped and $q \lesssim 1$. As the
disc/planet interaction is characterized by $t_e/t_a \sim 10^{-2}$, we conclude
that excitation of inclination through the type of resonance described here is
very unlikely to happen in a system of two planets migrating in a disc.",1406.2189v1
2016-05-20,Two-dimensional terahertz magnetic resonance spectroscopy of collective spin waves,"Nonlinear manipulation of nuclear and electron spins is the basis for all
advanced methods in magnetic resonance including multidimensional nuclear
magnetic and electron spin resonance spectroscopies, magnetic resonance
imaging, and in recent years, quantum control over individual spins. The
methodology is facilitated by the ease with which the regime of strong coupling
can be reached between radiofrequency or microwave magnetic fields and nuclear
or electron spins respectively, typified by sequences of magnetic pulses that
control the magnetic moment directions. The capabilities meet a bottleneck,
however, for far-infrared magnetic resonances characteristic of correlated
electron materials, molecular magnets, and proteins that contain high-spin
transition metal ions. Here we report the development of two-dimensional
terahertz magnetic resonance spectroscopy and its use for direct observation of
the nonlinear responses of collective spin waves (magnons). The spectra show
magnon spin echoes and 2-quantum signals that reveal pairwise correlations
between magnons at the Brillouin zone center. They also show resonance-enhanced
second-harmonic and difference-frequency signals. Our methods are readily
generalizable to multidimensional magnetic resonance spectroscopy and nonlinear
coherent control of terahertz-frequency spin systems in molecular complexes,
biomolecules, and materials.",1605.06476v3
2016-08-03,Plasmons and terahertz devices in graphene,"We introduce a novel scheme for efficient manipulation and detection of
terahertz (THz) radiation. Our work consists of two parts; with a focus on
proving the concept of our novel scheme, and the exploitation of graphene's
peculiar properties.
  For the first part, we report on the successful demonstration of two
multiresonance Split Ring Resonator (SRR) designs, for efficient modulation of
THz frequency beams. The two designs are based on SRR intracoupling, with
multiple predefined resonances covering the bandwidth 40-300 GHz. The
simulation results obtained have been experimentally verified.
  The second part of the work reports on the computational development of novel
architectures of low-impedance broadband antennas, for efficient detection of
THz frequency beams. The conceived Split Ring Resonator-Resonance Assisted
(SRR-RA) antennas are based on both a capacitive and inductive scheme,
exploiting a 200 $\Omega$ and 400 $\Omega$ impedance, respectively. Moreover,
the impedance is tunable by varying the geometry's coupling parameters,
allowing for better matching with the detector circuit for maximum power
extraction. Our results have been obtained at simulation level for a 1.5 THz
operation frequency.",1608.01215v2
2016-12-05,Is a Trineutron Resonance Lower in Energy than a Tetraneutron Resonance?,"We present quantum Monte Carlo calculations of few-neutron systems confined
in external potentials based on local chiral interactions at
next-to-next-to-leading order in chiral effective field theory. The energy and
radial densities for these systems are calculated in different external
Woods-Saxon potentials. We assume that their extrapolation to zero
external-potential depth provides a quantitative estimate of three- and
four-neutron resonances. The validity of this assumption is demonstrated by
benchmarking with an exact diagonalization in the two-body case. We find that
the extrapolated trineutron resonance, as well as the energy for shallow well
depths, is lower than the tetraneutron resonance energy. This suggests that a
three-neutron resonance exists below a four-neutron resonance in nature and is
potentially measurable. To confirm that the relative ordering of three- and
four-neutron resonances is not an artifact of the external confinement, we test
that the odd-even staggering in the helium isotopic chain is reproduced within
this approach. Finally, we discuss similarities between our results and
ultracold Fermi gases.",1612.01502v2
2016-12-04,Quantum Theory of Amplification in RS,"The equations for the amplitudes of transition probabilities are found. The
resonance frequency of the system is calculated. It is shown the dependence of
the resonance frequency on the initial transverse coordinate of an electron.
This dependence is analized.",1612.01846v1
2016-12-13,Omni-resonant optical micro-cavity,"Optical cavities are a cornerstone of photonics. They are indispensable in
lasers, optical filters, optical combs and clocks, in quantum physics, and have
enabled the detection of gravitational waves. Cavities transmit light only at
discrete resonant frequencies, which are well-separated in micro-structures.
Despite attempts at the construction of `white-light cavities', the benefits
accrued upon optically interacting with a cavity -- such as resonant field
buildup -- have remained confined to narrow linewidths. Here, we demonstrate
achromatic optical transmission through a planar Fabry-Perot micro-cavity via
angularly multiplexed phase-matching that exploits a bio-inspired grating
configuration. By correlating each wavelength with an appropriate angle of
incidence, a continuous spectrum resonates and the micro-cavity is rendered
transparent. The locus of a single-order 0.7-nm-wide resonance is de-slanted in
spectral-angular space to become a 60-nm-wide achromatic resonance spanning
multiple cavity free-spectral-ranges. This approach severs the link between the
resonance bandwidth and the cavity-photon lifetime, thereby promising resonant
enhancement of linear and nonlinear optical effects over broad bandwidths in
ultrathin devices.",1612.04328v1
2016-12-21,"A resonant chain of four transiting, sub-Neptune planets","Surveys have revealed many multi-planet systems containing super-Earths and
Neptunes in orbits of a few days to a few months. There is debate whether in
situ assembly or inward migration is the dominant mechanism of the formation of
such planetary systems. Simulations suggest that migration creates tightly
packed systems with planets whose orbital periods may be expressed as ratios of
small integers (resonances), often in a many-planet series (chain). In the
hundreds of multi-planet systems of sub-Neptunes, more planet pairs are
observed near resonances than would generally be expected, but no individual
system has hitherto been identified that must have been formed by migration.
Proximity to resonance enables the detection of planets perturbing each other.
Here we report transit timing variations of the four planets in the Kepler-223
system, model these variations as resonant-angle librations, and compute the
long-term stability of the resonant chain. The architecture of Kepler-223 is
too finely tuned to have been formed by scattering, and our numerical
simulations demonstrate that its properties are natural outcomes of the
migration hypothesis. Similar systems could be destabilized by any of several
mechanisms, contributing to the observed orbital-period distribution, where
many planets are not in resonances. Planetesimal interactions in particular are
thought to be responsible for establishing the current orbits of the four giant
planets in the Solar System by disrupting a theoretical initial resonant chain
similar to that observed in Kepler-223.",1612.07376v1
2017-07-04,Broadening the Reach of Simplified Limits on Resonances at the LHC,"Recently, we introduced an approach for more easily interpreting searches for
resonances at the LHC - and to aid in distinguishing between realistic and
unrealistic alternatives for potential signals. This `simplfied limits'
approach was derived using the narrow width approximation (NWA) - and therefore
was not obviously relevant in the case of wider resonances. Here, we broaden
the scope of the analysis. First, we explicitly generalize the formalism to
encompass resonances of finite width. We then examine how the width of the
resonance modifies bounds on new resonances that are extracted from LHC
searches. Second, we demonstrate, using a wide variety of cases, with different
incoming partons, resonance properties, and decay signatures, that the limits
derived in the NWA yield pertinant, and somewhat conservative (less stringent)
bounds on the model parameters. We conclude that the original simplified limits
approach is useful in the early stages of evaluating and interpreting new
collider data and that the generalized approach is a valuable further aid when
evidence points toward a broader resonance.",1707.01080v2
2017-07-06,Observation of the Borromean three-body Förster resonances for three interacting Rb Rydberg atoms,"Three-body F\""orster resonances at long-range interactions of Rydberg atoms
were first predicted and observed in Cs Rydberg atoms by R.Faoro et al., Nature
Comm. 6, 8173 (2015). In these resonances, one of the atoms carries away an
energy excess preventing the two-body resonance, leading thus to a Borromean
type of F\""orster energy transfer. But they were in fact observed as the
average signal for the large number of atoms $N\gg1$. In this Letter we report
on the first experimental observation of the three-body F\""orster resonances
${\rm 3}\times nP_{3/2} (|{\rm M}|)\to nS_{1/2} +(n+1)S_{1/2} +nP_{3/2} (|{\rm
M}^{*} |)$ in a few Rb Rydberg atoms with $n=36, 37$. We have found here clear
evidence that there is no signature of the three-body F\""orster resonance for
exactly two interacting Rydberg atoms, while it is present for $N=3-5$ atoms.
This demonstrates the assumption that three-body resonances can generalize to
any Rydberg atom. As such resonance represents an effective three-body
operator, it can be used to directly control the three-body interactions in
quantum simulations and quantum information processing with Rydberg atoms.",1707.01636v2
2017-07-06,Improving superconducting resonators in magnetic fields by reduced field-focussing and engineered flux screening,"We experimentally investigate superconducting coplanar waveguide resonators
in external magnetic fields and present two strategies to reduce field-induced
dissipation channels and resonance frequency shifts. One of our approaches is
to significantly reduce the superconducting ground-plane areas, which leads to
reduced magnetic field-focussing and thus to lower effective magnetic fields
inside the waveguide cavity. By this measure, the field-induced losses can be
reduced by more than one order of magnitude in mT out-of-plane magnetic fields.
When these resonators are additionally coupled inductively instead of
capacitively to the microwave feedlines, an intrinsic closed superconducting
loop is effectively shielding the heart of the resonator from magnetic fields
by means of flux conservation. In total, we achieve a reduction of the
field-induced resonance frequency shift by up to two orders of magnitude. We
combine systematic parameter variations on the experimental side with numerical
magnetic field calculations to explain the effects of our approaches and to
support our conclusions. The presented results are relevant for all areas,
where high-performance superconducting resonators need to be operated in
magnetic fields, e.g. for quantum hybrid devices with superconducting circuits
or electron spin resonance detectors based on coplanar waveguide cavities.",1707.01936v1
2017-07-08,The disturbing function for polar Centaurs and transneptunian objects,"The classical disturbing function of the three-body problem is based on an
expansion of the gravitational interaction in the vicinity of nearly coplanar
orbits. Consequently, it is not suitable for the identification and study of
resonances of the Centaurs and transneptunian objects on nearly polar orbits
with the solar system planets. Here, we provide a series expansion algorithm of
the gravitational interaction in the vicinity of polar orbits and produce
explicitly the disturbing function to fourth order in eccentricity and
inclination cosine. The properties of the polar series differ significantly
from those of the classical disturbing function: the polar series can model any
resonance as the expansion order is not related to the resonance order. The
powers of eccentricity and inclination of the force amplitude of a $p$:$q$
resonance do not depend on the value of the resonance order $|p-q|$ but only on
its parity. Thus all even resonance order eccentricity amplitudes are $\propto
e^2$ and odd ones $\propto e$ to lowest order in eccentricity $e$. With the new
findings on the structure of the polar disturbing function and the possible
resonant critical arguments, we illustrate the dynamics of the polar resonances
1:3, 3:1, 2:9 and 7:9 where transneptunian object 471325 could currently be
locked.",1707.02431v1
2017-07-11,Tilting Styx and Nix but not Uranus with a Spin-Precession-Mean-motion resonance,"A Hamiltonian model is constructed for the spin axis of a planet perturbed by
a nearby planet with both planets in orbit about star. We expand the
planet-planet gravitational potential perturbation to first order in orbital
inclinations and eccentricities, finding terms describing spin resonances
involving the spin precession rate and the two planetary mean motions.
Convergent planetary migration allows the spinning planet to be captured into
spin resonance. With initial obliquity near zero, the spin resonance can lift
the planet's obliquity to near 90 or 180 degrees depending upon whether the
spin resonance is first or zero-th order in inclination. Past capture of Uranus
into such a spin resonance could give an alternative non-collisional scenario
accounting for Uranus's high obliquity. However we find that the time spent in
spin resonance must be so long that this scenario cannot be responsible for
Uranus's high obliquity. Our model can be used to study spin resonance in
satellite systems. Our Hamiltonian model explains how Styx and Nix can be
tilted to high obliquity via outward migration of Charon, a phenomenon
previously seen in numerical simulations.",1707.03180v2
2017-10-11,The disturbing function for asteroids with arbitrary inclinations,"The classical disturbing function of the three-body problem widely used in
planetary dynamics studies is an expansion of the gravitational interaction of
the three-body problem with respect to zero eccentricity and zero inclination.
This restricts its validity to nearly coplanar orbits. Motivated by the
dynamical study of asteroids, Centaurs and transneptunian objects with
arbitrary inclinations, we derive a series expansion of the gravitational
interaction with respect to an arbitrary reference inclination that generalises
our work on the polar and retrograde disturbing functions. The new disturbing
function, like the polar one, may model any resonance as expansion order is
unrelated to resonance order. The powers of eccentricity and inclination of the
force amplitude of a $p$:$q$ resonance depend only on the parity of the
resonance order $|p-q|$. Disturbing functions with non zero reference
inclinations are thus physically different from the classical disturbing
function as the former are based on the three-dimensional three-body problem
and the latter on the two-dimensional one. We illustrate the use of the new
disturbing function by showing that what is known as pure eccentricity
resonances are intrinsically dependent on inclination contrary to the
prediction of the classical disturbing function. We determine the inclination
dependence of the resonance widths of the 2:1 and 3:1 prograde and retrograde
inner resonances with Jupiter as well as those of the asymmetric librations of
the 1:2 and 1:3 prograde outer resonances with Neptune.",1710.03902v1
2018-01-13,Chiral NNLO$_{\text{sat}}$ descriptions of nuclear multipole resonances within the random phase approximation,"We study nuclear multipole resonances in the framework of the random phase
approximation using the chiral potential NNLO$_{\text{sat}}$. This potential
includes two- and three-body terms that has been simultaneously optimized to
low-energy nucleon-nucleon scattering data and selected nuclear structure data.
Our main foci have been the isoscalar monopole, isovector dipole, and isoscalar
quadrupole resonances of the closed-shell nuclei, $^4$He, $^{16,22,24}$O, and
$^{40,48}$Ca. These resonance modes have been widely observed in experiment. In
addition, we use a renormalized chiral potential $V_{\text{low-}k}$, based on
the N$^3$LO two-body potential by Entem and Machleidt [Phys. Rev. \textbf{C68},
041001 (2011)]. This introduces a dependency on the cutoff parameter used in
the normalization procedure as reported in previous works by other groups.
While NNLO$_{\text{sat}}$ can reasonably reproduce observed multipole
resonances, it is not possible to find a single cutoff parameter for the
$V_{\text{low-}k}$ potential that simultaneously describe the different types
of resonance modes. The sensitivity to the cutoff parameter can be explained by
missing induced three-body forces in the calculations. Our results for
neutron-rich $^{22,24}$O show a mixing nature of isoscalar and isovector
resonances in the dipole channel at low energies. We predict that $^{22}$O and
$^{24}$O have low-energy isoscalar quadrupole resonances at energies lower than
5 MeV.",1801.04454v1
2018-01-15,Coupling Two Spin Qubits with a High-Impedance Resonator,"Fast, high-fidelity single and two-qubit gates are essential to building a
viable quantum information processor, but achieving both in the same system has
proved challenging for spin qubits. We propose and analyze an approach to
perform a long-distance two-qubit controlled phase (CPHASE) gate between two
singlet-triplet qubits using an electromagnetic resonator to mediate their
interaction. The qubits couple longitudinally to the resonator, and by driving
the qubits near the resonator's frequency they can be made to acquire a
state-dependent geometric phase that leads to a CPHASE gate independent of the
initial state of the resonator. Using high impedance resonators enables gate
times of order 10 ns while maintaining long coherence times. Simulations show
average gate fidelities of over 96% using currently achievable experimental
parameters and over 99% using state-of-the-art resonator technology. After
optimizing the gate fidelity in terms of parameters tuneable in-situ, we find
it takes a simple power-law form in terms of the resonator's impedance and
quality and the qubits' noise bath.",1801.04858v4
2018-01-29,Nucleon Resonance Structure from Exclusive Meson Electroproduction with CLAS,"Studies of the nucleon resonance electroexcitation amplitudes in a wide range
of photon virtualities offer unique information on many facets of strong QCD
behind the generation of all prominent excited nucleon states. Advances in the
evaluation of resonance electroexcitation amplitudes from the data measured
with the CLAS detector and the future extension of these studies with the
CLAS12 detector at Jefferson Lab are presented. For the first time, analyses of
$\pi^0p$, $\pi^+n$, $\eta p$, and $\pi^+\pi^-p$ electroproduction off proton
channels have provided electroexcitation amplitudes of most resonances in the
mass range up to 1.8 GeV and at photon virtualities $Q^2 < 5$~GeV$^2$.Studies
of the resonance electroexcitation amplitudes revealed the $N^*$ structure as a
complex interplay between the inner core of three dressed quarks and the
external meson-baryon cloud. The successful description of the
$\Delta(1232)3/2^+$ and $N(1440)1/2^+$ electrocouplings achieved within the
Dyson-Schwinger Equation approach under a traceable connection to the QCD
Lagrangian and supported by the novel light front quark model demonstrated the
relevance of dressed quarks with dynamically generated masses as an active
structural component in baryons. Future experiments with the CLAS12 detector
will offer insight into the structure of all prominent resonances at the
highest photon virtualities, $Q^2 < 12$~GeV$^2$, ever achieved in exclusive
reactions, thus addressing the most challenging problems of the Standard Model
on the nature of hadron mass, quark-gluon confinement, and the emergence of
nucleon resonance structures from QCD. A search for new states of hadronic
matter, the so-called hybrid-baryons with glue as a structural component, will
complete the long term efforts on the resonance spectrum exploration.",1801.09750v2
2018-09-20,Ultralow Thermal Conductivity in a Two-Dimensional Material due to Surface Enhanced Resonant Bonding,"Crystalline materials with ultralow thermal conductivity are highly desirable
for thermoelectric applications. Many known crystalline materials with low
thermal conductivity, including PbTe and Bi2Te3, possess a special kind of
chemical bond called ""resonant bond"". Resonant bonds consist of superposition
of degenerate bonding configurations that leads to structural instability,
anomalous long-range interatomic interaction and soft optical phonons. These
factors contribute to large lattice anharmonicity and strong phonon-phonon
scattering, which result in low thermal conductivity. In this work, we use
first-principles simulation to investigate the effect of resonant bonding in
two dimensions (2D), where resonant bonds are in proximity to the surface. We
find that the long-range interatomic interaction due to resonant bonding
becomes more prominent in 2D due to reduced screening of the
atomic-displacement-induced charge density distortion. To demonstrate this
effect, we analyze the phonon properties of quasi-2D Bi2PbTe4 with an ultralow
thermal conductivity of 0.74 W/mK at 300K. By comparing the interatomic force
constants of quasi-2D Bi2PbTe4 and its bulk counterpart, and the properties of
resonant bonds near the surface and in the bulk, we conclude that resonant
bonds are significantly enhanced in reduced dimensions and are more effective
in reducing the lattice thermal conductivity. Our results will provide new
clues to searching for thermal insulators in low-dimensional materials.",1809.07872v1
2018-10-29,"On the resonant reflection of weak, nonlinear sound waves off an entropy wave","We derive a degenerate quasilinear Schr\""odinger equation that describes the
resonant reflection of very weak, nonlinear sound waves off a weak sawtooth
entropy wave.",1810.11913v1
2019-06-19,Resonator Networks outperform optimization methods at solving high-dimensional vector factorization,"We develop theoretical foundations of Resonator Networks, a new type of
recurrent neural network introduced in Frady et al. (2020) to solve a
high-dimensional vector factorization problem arising in Vector Symbolic
Architectures. Given a composite vector formed by the Hadamard product between
a discrete set of high-dimensional vectors, a Resonator Network can efficiently
decompose the composite into these factors. We compare the performance of
Resonator Networks against optimization-based methods, including Alternating
Least Squares and several gradient-based algorithms, showing that Resonator
Networks are superior in several important ways. This advantage is achieved by
leveraging a combination of nonlinear dynamics and ""searching in
superposition,"" by which estimates of the correct solution are formed from a
weighted superposition of all possible solutions. While the alternative methods
also search in superposition, the dynamics of Resonator Networks allow them to
strike a more effective balance between exploring the solution space and
exploiting local information to drive the network toward probable solutions.
Resonator Networks are not guaranteed to converge, but within a particular
regime they almost always do. In exchange for relaxing this guarantee of global
convergence, Resonator Networks are dramatically more effective at finding
factorizations than all alternative approaches considered.",1906.11684v4
2019-06-28,Intrinsic dissipation mechanisms in metallic glass resonators,"Micro- and nano-resonators have important applications including sensing,
navigation, and biochemical detection. Their performance is quantified using
the quality factor $Q$, which gives the ratio of the energy stored to the
energy dissipated per cycle. Metallic glasses are a promising materials class
for micro- and nano-scale resonators since they are amorphous and can be
fabricated precisely into complex shapes on these lengthscales. To understand
the intrinsic dissipation mechanisms that ultimately limit large $Q$-values in
metallic glasses, we perform molecular dynamics simulations to model metallic
glass resonators subjected to bending vibrations. We calculate the vibrational
density of states, redistribution of energy from the fundamental mode of
vibration, and $Q$ versus the kinetic energy per atom $K$ of the excitation. In
the linear and nonlinear response regimes where there are no atomic
rearrangements, we find that $Q \rightarrow \infty$ (since we do not consider
coupling to the environment). We identify a characteristic $K_r$ above which
atomic rearrangements occur, and there is significant energy leakage from the
fundamental mode to higher frequencies, causing finite $Q$. Thus, $K_r$ is a
critical parameter determining resonator performance. We show that $K_r$
decreases as a power-law, $K_r\sim N^{-k},$ with increasing system size $N$,
where $k \approx 1.3$. We estimate the critical strain $\langle \gamma_r
\rangle \sim 10^{-8}$ for micron-sized resonators below which atomic
rearrangements do not occur, and thus large $Q$-values can be obtained when
they are operated below $\gamma_r$. We find that $K_r$ for amorphous resonators
is comparable to that for resonators with crystalline order.",1907.00052v1
2019-07-31,Resonant photoproduction of high-energy electron-positron pairs in the field of a nucleus and a plane electromagnetic wave,"The resonant photoproduction of ultrarelativistic electron-positron pairs
(PPP) in a nuclear field and a weak laser field is theoretically studied. Under
resonance conditions, the intermediate virtual electron (positron) in the laser
field becomes a real particle. As a result, the initial process of the second
order in the fine structure constant in the laser field effectively reduces
into two successive processes of the first order: single-photon production of
electron-positron pair in a laser field (laser-stimulated Breit-Wheeler
process) and laser-assisted process of electron (positron) scattering on a
nucleus. Resonant kinematics of PPP is studied in details. It is shown that for
the considered laser intensities resonance is possible only for the initial
photon energies greater than the characteristic threshold energy. At the same
time, the ultrarelativistic electron and positron propagate in a narrow cone
along the direction of the initial photon momentum. The resonant energy of the
positron (electron) can has two values for each radiation angle which varies
from zero to some maximum value determined by the energy of the initial photon
and the threshold energy. Resonant differential cross section of the studied
process was obtained. It is shown that the resonant differential cross section
of the PPP can significantly exceed the corresponding cross section of the PPP
without an external field. The project calculations may be experimentally
verified by the scientific facilities of pulsed laser radiation (SLAC, FAIR,
XFEL, ELI, XCELS)",1907.13560v1
2019-09-30,Ultrafast sensing of photoconductivity decay using microwave resonators,"Microwave reflectance probed photoconductivity (or $\mu$-PCD) measurement
represents a contactless and non-invasive method to characterize impurity
content in semiconductors. Major drawbacks of the method include a difficult
separation of reflectance due to dielectric and conduction effects and that the
$\mu$-PCD signal is prohibitively weak for highly conducting samples. Both of
these limitations could be tackled with the use of microwave resonators due to
the well-known sensitivity of resonator parameters to minute changes in the
material properties combined with a null measurement. A general misconception
is that time resolution of resonator measurements is limited beyond their
bandwidth by the readout electronics response time. While it is true for
conventional resonator measurements, such as those employing a frequency sweep,
we present a time-resolved resonator parameter readout method which overcomes
these limitations and allows measurement of complex material parameters and to
enhance $\mu$-PCD signals with the ultimate time resolution limit being the
resonator time constant. This is achieved by detecting the transient response
of microwave resonators on the timescale of a few 100 ns \emph{during} the
$\mu$-PCD decay signal. The method employs a high-stability oscillator working
with a fixed frequency which results in a stable and highly accurate
measurement.",1909.13598v2
2019-10-27,Tetraneutron resonance in the presence of a dineutron,"Background: Several previous studies provided contradicting results for the
four-neutron system, some claiming the existence of a 0+ near-threshold
resonance, others denying presence of any observable resonant states. Purpose:
Since most of the studies employed enhanced two-neutron interactions to follow
the evolution of an artificially bound state into a continuum one, we examine
several enhancement schemes that produce a bound dineutron as well. Methods: We
study the four-neutron system by solving exact four-particle equations. By
varying the interaction enhancement factor we calculate two-dineutron
scattering phase shifts and cross sections. Results: When the same enhancement
factor is used in all partial waves, a bound tetraneutron emerges together with
a strongly bound dineutron. Furthermore, such a 0+ tetraneutron evolves not
into a resonance but into a virtual state. Weak enhancement of S waves together
with strongly enhanced higher waves is needed for the emergence of the resonant
state. Anyhow the resonant behavior disappears well before reaching the
physical interaction strength. Conclusions: The interaction enhancement scheme
using the same factor for all waves, employed in several previous works, is
misleading for the search of 0+ resonance as only a virtual state can emerge.
Evolution of a bound tetraneutron into a resonance via an intermediate virtual
state is possible with strong enhancement of higher two-neutron waves.",1910.12333v1
2019-10-30,A note on the experiment parameters for the non-resonant streaming instability: competition between left and right circularly polarized modes,"A non-resonant streaming instability driven by cosmic-ray currents, also
called Bell's instability, is proposed as a candidate for providing the
required magnetic turbulence of efficient diffusive shock accelerations. To
demonstrate the saturation level and mechanism of the non-resonant streaming
instability in a laboratory environment, we attempt to develop an experiment at
the Photo Injector Test Facility at DESY, Zeuthen site (PITZ). As an electron
beam is used to replace the proton beam to carry the cosmic-ray current in our
experiment, the polarization of the non-resonant streaming instability will be
modified from the left-handed (LH) mode to the right-handed (RH) mode. The
theoretical instability analysis shows that the growth rate of this RH
non-resonant mode may be smaller than it of the LH resonant mode. However the
LH resonant mode can be ignored in our experiment while the expected wavelength
is longer than the used plasma cell. The results of PIC simulations will also
support this contention and the occurrence of non-resonant streaming
instability in our experiment.",1910.13756v1
2020-01-30,Normally Hyperbolic Invariant Cylinders Passing Through Multiple Resonance,"We study the continuation of periodic orbits from various compound of
homoclinics in classical system. Together with the homoclinics, the periodic
orbits make up a $C^1$-smooth, normally hyperbolic invariant cylinder with
holes. It plays a key role to cross multiple resonant point.",2001.11223v1
2020-02-20,Transit of asteroids across the 7/3 Kirkwood gap under the Yarkovsky effect,"Many asteroids in the main belt are continuously pushed by Yarkovsky effect
into regions of different mean motion resonances (MMRs) and then ejected out.
They are considered as the principal source of near-Earth objects. We
investigate in this paper the effects of the 7/3 MMR with Jupiter (J7/3 MMR) on
the transportation of asteroids from Koronis and Eos families that reside
respectively on the inner and outer side of the resonance. The fraction of
asteroids that make successful crossing through the resonance and the escaping
rate from the resonance are found to depend on the Yarkovsky drifting rate, the
initial inclination and the migrating direction. The excitation of eccentricity
and inclination due to the combined influence from both the resonance and
Yarkovsky effect is discussed. Only the eccentricity can be pumped up
considerably, and it is attributed mainly to the resonance. In the
observational data, family members are also found in the resonance and on the
opposite side of the resonance with respect to the corresponding family centre.
The existence of these family members is explained using our results of
numerical simulations. Finally, the replenishment of asteroids in the J7/3 MMR
and the transportation of asteroids by it are discussed.",2002.08794v1
2020-04-03,How to suppress exponential growth -- on the parametric resonance of photons in an axion background,"Axion--photon interactions can lead to an enhancement of the electromagnetic
field by parametric resonance in the presence of a cold axion background, for
modes with a frequency close to half the axion mass. In this paper, we study
the role of the axion momentum dispersion as well as the effects of a
background gravitational potential, which can detune the resonance due to
gravitational redshift. We show, by analytical as well as numerical
calculations, that the resonance leads to an exponential growth of the photon
field only if (a) the axion momentum spread is smaller than the inverse
resonance length, and (b) the gravitational detuning distance is longer than
the resonance length. For realistic parameter values, both effects strongly
suppress the resonance and prevent the exponential growth of the photon field.
In particular, the redshift due to the gravitational potential of our galaxy
prevents the resonance from developing for photons in the observable frequency
range, even assuming that all the dark matter consists of a perfectly cold
axion condensate. For axion clumps with masses below $\sim 10^{-13}\, M_\odot$,
the momentum spread condition is more restrictive, whereas, for more massive
clumps, the redshift condition dominates.",2004.01669v2
2020-12-15,Shifting and splitting of resonance lines due to dynamical friction in plasmas,"A quasilinear plasma transport theory that incorporates Fokker-Planck
dynamical friction (drag) and pitch angle scattering is self-consistently
derived from first principles for an isolated, marginally-unstable mode
resonating with an energetic minority species. It is found that drag
fundamentally changes the structure of the wave-particle resonance, breaking
its symmetry and leading to the shifting and splitting of resonance lines. In
contrast, scattering broadens the resonance in a symmetric fashion. Comparison
with fully nonlinear simulations shows that the proposed quasilinear system
preserves the exact instability saturation amplitude and the corresponding
particle redistribution of the fully nonlinear theory. Even in situations in
which drag leads to a relatively small resonance shift, it still underpins
major changes in the redistribution of resonant particles. This novel influence
of drag is equally important in plasmas and gravitational systems. In fusion
plasmas, the effects are especially pronounced for fast-ion-driven
instabilities in tokamaks with low aspect ratio or negative triangularity, as
evidenced by past observations. The same theory directly maps to the resonant
dynamics of the rotating galactic bar and massive bodies in its orbit,
providing new techniques for analyzing galactic dynamics.",2012.08661v2
2020-12-22,Semi-analytical model for planetary resonances: application to planets around single and binary stars,"In spite of planetary resonances being a common dynamical mechanism acting on
planetary systems, no general model exists for describing their properties,
particularly for commensurabilities of any order and arbitrary values of the
eccentricities and inclinations. The present work presents a semi-analytical
model that describes the resonance strength, width, location and stability of
fixed points, as well as periods of small-amplitude librations. The model is
valid to any two gravitationally interacting massive bodies, and thus
applicable to planets around single or binary stars. Using a theoretical
framework in Poincar\'e and Jacobi reference system we develop a
semi-analytical method that employs a numerical evaluation of the averaged
resonant disturbing function. Validations of the model are presented comparing
its predictions with dynamical maps for real and fictitious systems. The model
is shown to describe very well many dynamical features of planetary resonances.
Notwithstanding the good agreements found in all cases, a small deviation is
noted in the location of the resonance centers for circumbinary systems. As a
consequence of its application to the HD31527 system we have found that the
updated best-fit solution leads to a high-eccentricity stable libration between
the middle and outer planets inside the 16/3 mean-motion resonance. This is the
first planetary system whose long-term dynamics appears dominated by such a
high-order commensurability. In the case of circumbinary planets, the overlap
of N/1 mean-motion resonances coincides very well with the size of the global
chaotic region close to the binary, as well as its dependence with the mutual
inclination.",2012.12296v1
2020-12-30,Nonrelativistic Effective Field Theory with a Resonance Field,"We discuss shallow resonances in the nonrelativistic scattering of two
particles using an effective field theory (EFT) that includes an auxiliary
field with the quantum numbers of the resonance. We construct the manifestly
renormalized scattering amplitude up to next-to-leading order in a systematic
expansion. For a narrow resonance, the amplitude is perturbative except in the
immediate vicinity of the resonance poles. It naturally has a zero in the
low-energy region, analogous to the Ramsauer-Townsend effect. For a broad
resonance, the leading-order amplitude is nonperturbative almost everywhere in
the regime of validity of the EFT. We regain the results of an EFT without the
auxiliary field, which is equivalent to the effective-range expansion with
large scattering length and effective range. We also consider an additional
fine tuning leading to a low-energy amplitude zero even for a broad resonance.
We show that in all cases the requirement of renormalizability when the
auxiliary field is not a ghost ensures the resonance poles are in the lower
half of the complex momentum plane, as expected by other arguments. The
systematic character of the EFT expansion is exemplified with a toy model
serving as underlying theory.",2012.14995v2
2021-01-04,"Imaging vibrations of locally gated, electromechanical few layer graphene resonators with a moving vacuum enclosure","Imaging the vibrations of nanomechanical resonators means measuring their
flexural mode shapes from the dependence of their frequency response on
in-plane position. Applied to two-dimensional resonators, this technique
provides a wealth of information on the mechanical properties of
atomically-thin membranes. We present a simple and robust system to image the
vibrations of few layer graphene (FLG) resonators at room temperature and in
vacuum with an in-plane displacement precision of $\approx0.20$ $\mu$m. It
consists of a sturdy vacuum enclosure mounted on a three-axis micropositioning
stage and designed for free space optical measurements of vibrations. The
system is equipped with ultra-flexible radio frequency waveguides to
electrically actuate resonators. With it we characterize the lowest frequency
mode of a FLG resonator by measuring its frequency response as a function of
position on the membrane. The resonator is suspended over a nanofabricated
local gate electrode acting both as a mirror and as a capacitor plate to
actuate vibrations at radio frequencies. From these measurements, we estimate
the ratio of thermal expansion coefficient to thermal conductivity of the
membrane, and we measure the effective mass of the lowest frequency mode. We
complement our study with a globally gated resonator and image its first three
vibration modes. There, we find that folds in the membrane locally suppress
vibrations.",2101.00888v1
2021-01-29,Electrokinetic oscillatory flow and energy conversion of viscoelastic fluids in microchannels: a linear analysis,"We study the electrokinetic flow of viscoelastic fluids subjected to an
oscillatory pressure gradient, and particularly focus on the resonance
behaviors in the flow. The governing equations are restricted to linear regime
so that the velocity and streaming potential fields can be solved analytically.
Based on the interaction of viscoelastic shear waves, we explain the mechanism
of resonance, and derive a critical Deborah number Dec = 1/4 which dictates the
occurrence of resonance. Using the Maxwell fluid model, we show that the
resonance enhances electrokinetic effects and results in a dramatic increase of
electrokinetic energy conversion efficiency. However, by applying the Oldroyd-B
fluid model it reveals that the amplification of efficiency is suppressed even
for a very small Newtonian solvent contribution. This may be one of the reasons
that experimental verification regarding the high efficiency predicted by
Bandopadhyay & Chakraborty (Appl. Phys. Lett., vol. 101, 2012, 043905) is
unavailable in the literature. Furthermore, the damping effect of solvent
viscosity is more significant for higher-order resonances. Introducing the
factor of multiple relaxation times, we show that the occurrence of resonances
for the streaming potential field and the flow rate are still dominated by Dec.
For the efficiency in the multi-mode case, the occurrence of resonance is
dominated by the Deborah number De and the mode number N, and the resonance
disappears for small De or large N. In addition, a new type of scaling relation
between the streaming potential field and EDL thickness can be identified at
large De.",2101.12517v1
2012-05-11,Ressonant elliptic problems under Cerami condition,"We establish existence and multiplicity of solutions for a elliptic resonant
elliptic problem under Dirichlet boundary conditions.",1205.2724v1
2012-05-30,Quantum noise properties of multiphoton transitions in driven nonlinear resonators,"We investigate the quantum noise properties of a weakly nonlinear Duffing
resonator in the deep quantum regime, where only few quanta are excited. This
regime is dominated by the appearance of coherent multiphoton resonances in the
nonlinear response of the resonator to the modulation. We determine simple
expressions for the photon noise spectrum and find that the multiphoton
resonances also induces a multiple peak structure in that noise. When the
corresponding multiphoton Rabi oscillations are underdamped, zero temperature
quantum fluctuations determine comparable populations of all quasienergy states
which belong to a resonant multiphoton doublet. Most interestingly, the quantum
fluctuations probe the multiphoton transitions by inducing several peaks in the
noise spectrum of the resonator observables. In particular, the noise of the
photon number contains complete information about the multiphoton states and
their stationary populations via pairs of nearly symmetric peaks at opposite
frequencies. Their widths are determined by the damping of the Rabi
oscillations and their heights are proportional to the stationary nonequilbrium
populations. A finite detuning from a multiphoton resonance generates a
quasielastic noise peak at zero frequency. In addition, we relate the
stationary populations of the quasienergy states with an effective quantum
temperature and discuss the role of a finite temperature.",1205.6797v1
2017-05-31,The multi-resonant Lugiato-Lefever model,"We introduce a new model describing multiple resonances in Kerr optical
cavities. It perfectly agrees quantitatively with the Ikeda map and predicts
complex phenomena such as super cavity solitons and coexistence of multiple
nonlinear states.",1705.11086v2
2018-07-10,Nonreciprocal control and cooling of phonon modes in an optomechanical system,"Phononic resonators play important roles in settings that range from
gravitational wave detectors to cellular telephones. They serve as
high-performance transducers, sensors, and filters by offering low dissipation,
tunable coupling to diverse physical systems, and compatibility with a wide
range of frequencies, materials, and fabrication processes. Systems of phononic
resonators typically obey reciprocity, which ensures that the phonon
transmission coefficient between any two resonators is independent of the
direction of transmission. Reciprocity must be broken to realize devices (such
as isolators and circulators) that provide one-way propagation of acoustic
energy between resonators. Such devices are crucial for protecting active
elements, mitigating noise, and operating full-duplex transceivers. To date,
nonreciprocal phononic devices have not combined the features necessary for
robust operation: strong nonreciprocity, in situ tunability, compact
integration, and continuous operation. Furthermore, they have been applied only
to coherent signals (rather than fluctuations or noise), and have been realized
exclusively in travelling-wave systems (rather than resonators). Here we
describe a cavity optomechanical scheme that produces robust nonreciprocal
coupling between phononic resonators. This scheme provides ~ 30 dB of isolation
and can be tuned in situ simply via the phases of the drive tones applied to
the cavity. In addition, by directly monitoring the resonators' dynamics we
show that this nonreciprocity can be used to control thermal fluctuations, and
that this control represents a new resource for cooling phononic resonators.",1807.03484v1
2018-12-25,"Collisionless absorption of short laser pulses in a deuterium cluster: dependence of redshift of resonance absorption peak on laser polarization, intensity and wavelength","We study collisionless absorption of short laser pulses of various intensity,
wavelength ($\lambda$) and polarization in a deuterium cluster using molecular
dynamics (MD) simulation. For a given laser energy and a pulse duration
$\approx$ 5-fs (fwhm), it is found that maximum laser absorption does not
happen at the welknown static Mie-resonance or linear resonance (LR) wavelength
of $\lambdaM\approx 263$~nm (for deuterium cluster) irrespective of linear
polarization (LP) and circular polarization (CP) state of laser. As the laser
intensity increases, the absorption peak is gradually red-shifted to a higher
$\lambda$ in the marginally over-dense regime of $\lambda\!\! \approx
\!\!(1\!\!-\!\!1.5)\lambdaM$ from the expected static~$\lambdaM$ owing to
gradual outer ionization and cluster expansion; and above an intensity the
resonance absorption peak disappears (sometimes followed by {\em even} a growth
of absorption) when outer ionization saturates at 100\% for both LP and CP.
This disappearance of the resonance absorption peak should not be
misinterpreted as the negligible (or no) role of Mie-resonance. In fact, in
this marginally over-dense band of $\lambda\!\! \approx
\!\!(1\!\!-\!\!1.5)\lambdaM$, some electrons undergo dynamic Mie-resonance
(dynamic LR) and others anharmonic resonance when they are freed. It is also
found that before the absorption peak, laser absorption due to LP and CP lasers
are almost equally efficient (CP case being inappreciably higher than LP) for
all intensities and $\lambda$. However, after the absorption peak, at lower
intensities, absorption due to LP inappreciably dominates absorption due to CP
with increasing~$\lambda$ which gradually reverses at higher intensities. MD
results are also supported by a naive rigid sphere model of cluster.",1812.10046v1
2019-04-02,Axion resonances in binary pulsar systems,"We investigate the extent to which resonances between an oscillating
background of ultra-light axion and a binary Keplerian system can affect the
motion of the latter. These resonances lead to perturbations in the
instantaneous time-of-arrivals, and to secular variations in the period of the
binary. While the secular changes at exact resonance have recently been
explored, the instantaneous effects have been overlooked. In this paper, we
examine the latter using N-body simulations including the external oscillatory
forcing induced by the axion background. While the secular effects are
restricted to a narrow width near the resonance, the instantaneous changes,
albeit strongest close to resonances, are apparent for wide range of
configurations. We compute the signal-to-noise ratio (SNR) as a function of
semi-major axis for a detection of axion oscillations through the R\{o} mer
delay. The latter can be extracted from the time-of-arrivals of binary pulsars.
The SNR broadly increases with increasing binary eccentricity in agreement with
the secular expectation. However, we find that it differs significantly from
the scaling a^{5/2} around the lowest orders of resonance. Future observations
could probe these effects away from resonances and, therefore, constrain a much
broader range of axion masses provided that binary pulsar systems are found
near the central region of our Galaxy, and that the time-or-arrival measurement
accuracy reaches < 10 ns",1904.01958v4
2019-04-12,Charge-photon transport statistics and short-time correlations in a single quantum dot-resonator system with arbitrarily large coupling parameter,"Electrical quantum conductors coupled to microwave resonators have in the
last decade emerged as a versatile testbed for controllable light-matter
interaction on the nanometer scale. Recent experimental progress with high
impedance resonators has resulted in conductor-resonator systems with a large,
dimensionless coupling parameter $\lambda \gtrsim 0.1$, well beyond the small
coupling regime $\lambda \ll 1$. Motivated by this progress, we here analyse
theoretically the joint statistics of transported electrons and emitted photons
in a single level quantum dot coupled to a microwave resonator, for arbitrarily
large $\lambda$. Describing the electron-photon dynamics via a number-resolved
master equation, we evaluate the joint long-time probability distribution as
well as joint short-time, $g^{(2)}(t)$, correlation functions. Considering the
high-bias regime, with sequential electron tunneling and working in the damping
basis, allows us to obtain analytical results for both transport cumulants and
$g^{(2)}(t)$ functions. It is found that the photons emitted out of the
resonator are bunched and display a super-Poissonian statistics, for all system
parameters. However, the electron transport properties are found to be
unaffected by the coupling to the resonator, anti-bunched and with
sub-Poissonian statistics. From the joint distribution we identify regimes of
electron tunneling induced photon cascades and very large $g^{(2)}(t)$
functions. All $g^{(2)}(t)$-functions are found to be independent of $\lambda$.
We also identify conditions for and transport signatures of a thermal resonator
photon state.",1904.06448v1
2019-08-20,Non-volatile rewritable frequency tuning of a nanoelectromechanical resonator using photoinduced doping,"Tuning the frequency of a resonant element is of vital importance in both the
macroscopic world, such as when tuning a musical instrument, as well as at the
nanoscale. In particular, precisely controlling the resonance frequency of
isolated nanoelectromechanical resonators (NEMS) has enabled innovations such
as tunable mechanical filtering and mixing as well as commercial technologies
such as robust timing oscillators. Much like their electronic device
counterparts, the potential of NEMS grows when they are built up into
large-scale arrays. Such arrays have enabled neutral-particle mass spectroscopy
and have been proposed for ultralow-power alternatives to traditional analog
electronics as well as nanomechanical information technologies like memory,
logic, and computing. A fundamental challenge to these applications is to
precisely tune the vibrational frequency and coupling of all resonators in the
array, since traditional tuning methods, like patterned electrostatic gating or
dielectric tuning, become intractable when devices are densely packed. Here, we
demonstrate a persistent, rewritable, scalable, and high-speed frequency tuning
method for graphene-based NEMS. Our method uses a focused laser and two shared
electrical contacts to photodope individual resonators by simultaneously
applying optical and electrostatic fields. After the fields are removed, the
trapped charge created by this process persists and applies a local
electrostatic tension to the resonators, tuning their frequencies. By providing
a facile means to locally address the strain of a NEMS resonator, this approach
lays the groundwork for fully programmable large-scale NEMS lattices and
networks.",1908.07609v2
2019-08-25,Peripheral convex expansions of resonance graphs,"In this paper, we show that the resonance graph of a plane elementary
bipartite graph $G$ can be obtained from an edge by a sequence of peripheral
convex expansions with respect to a reducible face decomposition of $G$ if and
only if the infinite face of $G$ is forcing.",1908.09342v1
2019-11-20,Anti-crossing properties of strong coupling system of silver nanoparticle dimers coated with thin dye molecular films analyzed by classical electromagnetism,"The evidence of strong coupling between plasmons and molecular excitons for
plasmonic nanoparticle (NP) dimers exhibiting ultra-sensitive surface enhanced
resonant Raman scattering is the observation of anti-crossing in the coupled
resonance. However, it is not easy to experimentally tune plasmon resonance of
such dimers for the observation. In this work, we theoretically investigate the
anti-crossing properties of the dimers coated by the thin dye films with
thicknesses greater than 0.1 nm and gap distances larger than 1.2 nm according
to the principles of classical electromagnetism. The plasmon resonance spectra
of these dimers are strongly affected by their coupling with the exciton
resonance of dye molecules. A comparison of the film thickness dependences of
dimer spectral changes with those of silver ellipsoidal NPs indicates that the
dipole plasmons localized in the dimer gap are coupled with molecular excitons
of the film much stronger than the dipole plasmons of ellipsoidal NPs.
Furthermore, the anti-crossing of coupled resonances is investigated while
tuning plasmon resonance by changing the morphology and refractive index of the
surrounding medium. The spectral changes observed for ellipsoidal NPs clearly
exhibit anti-crossing properties; however, the anti-crossing behavior of dimers
is more complex due to the strong coupling of dipoles and higher order plasmons
with multiple molecular excitons. We find that the anti-crossing for dimers is
clearly confirmed by the refractive index dependence of coupled resonance.",1911.08663v1
2020-03-28,Light ellipticity and polarization angle dependence of magnetic resonances in rubidium vapor using amplitude-modulated light: Theoretical and experimental investigations,"We report on experimental and theoretical investigations of the polarization
dependence of magnetic resonance generated by synchronous optical pumping.
Magnetic resonances with narrow linewidth are generated experimentally using a
rubidium vapor cell with octade-cyltrichlorosilane (OTS) antirelaxation coating
on inner walls. We studied the effect of light ellipticity on the amplitudes
and widths of magnetic resonances by matching the light modulation frequency
with 2 {\Omega}_L (alignment) and {\Omega}_L(orientation) in a Bell-Bloom
interaction geometry, where {\Omega}_L corresponds to the Larmor frequency.
Both 2 {\Omega}_L and \OmegaL resonance amplitudes showed a strong dependence
on the light ellipticity. In addition, we showed that the duty cycle of light
modulation changes the slope of amplitude variations in 2{\Omega}_L and
{\Omega}_L resonances with light ellipticity. As a potential application, we
showed that the difference between 2{\Omega}_Land {\Omega}_Lresonance
amplitudes can be used for in situ measurement of light ellipticity. We also
studied the dependence of 2{\Omega}_L and {\Omega}_L resonance amplitudes on
the polarization angle of linearly polarized light. These amplitudes oscillate
periodically with the polarization angle. We found this oscillatory behavior to
be sensitive to the tilt in magnetic field direction from the polarization
plane. Such a property could be used to realize a vector magnetometer. A
density matrix based theoretical model is developed to simulate the magnetic
resonance spectrum for different light polarizations. Our theoretical model
accurately reproduces the above mentioned experimental observations.",2003.12897v2
2020-05-06,Modeling Radial Velocity Data of Resonant Planets to Infer Migration Histories,"A number of giant planet pairs discovered by the radial velocity method with
period ratios $\lesssim 2$ may reside in mean motion resonances. Convergent
orbital migration and resonant capture at the time of formation would naturally
explain the present-day resonant orbital configurations of these systems.
Planets that experience smooth migration and eccentricity damping forces due to
a proto-planetary disk should not only capture into mean motion resonances but
also end up in a specific dynamical configuration within the resonance,
sometimes referred to as apsidal corotation resonance (ACR). Here we develop a
method for testing the hypothesis that a planet pair resides in an ACR by
directly fitting radial velocity data. The ACR hypothesis strongly restricts
the number of free parameters describing the radial velocity signal and we
compare fits using this highly restricted model to fits using a more
conventional two-planet RV model by using nested sampling simulations. We apply
our method to HD 45364 and HD 33844, two systems hosting giant planet pairs in
3:2 and 5:3 resonances, respectively. We demonstrate that the observations of
both systems support an ACR configuration and we use the results of our ACR
model fits to constrain possible migration histories of these systems.",2005.03034v2
2020-05-12,Engineering of the extremely high Q factor in two subwavelength dielectric resonators,"The high-Q {\it subwavelength} resonances in an isolated dielectric disk
modes can be achieved by avoided crossing (anticrossing) of the nonorthogonal
TE resonances under variation of the aspect ratio as it was reported by Rybin
{\it et al} [Phys. Rev. Lett. 119, 243901 (2017)]. Traversing over two
parameters, the aspect ratio and the distance between two disks, enhances the Q
factor by several times compared to the case of the former case of
one-parametric avoided crossing in the isolated disk. Therefore successive
two-parametric avoided crossing gives multiplicative gain in the Q-factor as it
was expected. However if for the single disk its orthogonal resonant modes do
not undergo avoided crossing, a presence of the second disk gives removes this
restriction and gives rise to the avoided crossing of these modes that enhances
the $Q$ factor by two orders in magnitude compared to the case of single disk.
Respectively the multipolar decomposition of the anti-bonding resonant mode
demonstrates conversion from lower to higher orders of the multipole modes
similar to that as shown by Chen {\it et al} [Laser&PhotonicsReviews 13,
1900067 (2019)]. These results are interpreted by that the field configuration
at the maximal conversion becomes close to the Mie resonant mode with high
orbital momentum in equivalent sphere. For m=1 the resonant modes leakage into
both type continua that substantially lowers the Q-factor of the subwavelength
resonant modes.",2005.05554v1
2020-05-26,Dynamical History of the Uranian System,"We numerically simulate the past tidal evolution of the five large moons of
Uranus (Miranda, Ariel, Umbriel, Titania, and Oberon). We find that the most
recent major mean-motion resonance (MMR) between any two moons, the
Ariel-Umbriel 5:3 MMR, had a large effect on the whole system. Our results
suggest that this resonance is responsible for the current 4.3$^{\circ}$
inclination of Miranda (instead of previously proposed 3:1 Miranda-Umbriel
MMR), and that all five moons had their inclinations excited during this
resonance. Miranda experienced significant tidal heating during the
Ariel-Umbriel 5:3 MMR due to its eccentricity being excited by Ariel's secular
perturbations. This tidal heating draws energy from shrinking of Miranda's
orbit, rather than Ariel's outward evolution, and can generate heat flows in
excess of 100 mW m$^{-2}$, sufficient to produce young coronae on Miranda. We
find that this MMR was followed by a sequence of secular resonances, which
reshuffled the moons' eccentricities and inclinations. We also find that the
precession of Oberon's spin axis is close to a resonance with the precession of
Umbriel's orbital plane, and that this spin-orbit resonance was likely excited
during the Ariel-Umbriel 5:3 MMR. After the exit from the MMR, subsequent
Ariel-Umbriel secular resonance and Oberon-Umbriel spin-orbit resonance may be
able to explain the current low inclinations of Ariel and Umbriel. The age of
Miranda's surface features tentatively suggests Uranian tidal
$Q=15,000-20,000$, which can be further refined in future work.",2005.12887v1
2020-08-09,Analysis of the dynamical evolution of the Quadrantid meteoroid stream,"We investigate numerically the dynamical evolution of simulated meteoroid
stream of the Quadrantids ejected from the parent body of the asteroid (196256)
2003 EH1. The main goal of this work is to identify mean motion and secular
resonances and to study the mutual influence of resonance relations and close
encounters with the major planets. Since the dynamics of this asteroid is
predictable only on short time intervals, and not only close and/or multiple
close encounters with major planets, but also the presence of at least one
unstable resonance can lead to chaotic motion of test particles, we studied
their resonant dynamics. The dynamical evolution of the test particles expects
possible scenario for resonant motion. We conjecture that the reasons of chaos
are the overlap of stable secular resonances and unstable mean motions
resonances and close and/or multiple close encounters with the major planets.
The estimate of the stability of orbits in which the particles in simulations
moved was carried out by analyzing the behavior of the parameter MEGNO (Mean
Exponential Growth factor of Nearby Orbits). The larger part of the identified
resonances is stable. We found a peculiar behavior for this stream. Here, we
show that the orbits of some ejected particles are strongly affected by the
Lidov-Kozai mechanism that protects them from close encounters with Jupiter.
Lack of close encounters with Jupiter leads to a rather smooth growth in the
parameter MEGNO and the behavior imply the stable motion of simulation
particles of the Quadrantids meteoroid stream.",2008.03823v1
2020-09-25,Frequency fluctuations in nanomechanical silicon nitride string resonators,"High quality factor ($Q$) nanomechanical resonators have received a lot of
attention for sensor applications with unprecedented sensitivity. Despite the
large interest, few investigations into the frequency stability of high-$Q$
resonators have been reported. Such resonators are characterized by a linewidth
significantly smaller than typically employed measurement bandwidths, which is
the opposite regime to what is normally considered for sensors. Here, the
frequency stability of high-$Q$ silicon nitride string resonators is
investigated both in open-loop and closed-loop configurations. The stability is
here characterized using the Allan deviation. For open-loop tracking, it is
found that the Allan deviation gets separated into two regimes, one limited by
the thermomechanical noise of the resonator and the other by the detection
noise of the optical transduction system. The point of transition between the
two regimes is the resonator response time, which can be shown to have a linear
dependence on $Q$. Laser power fluctuations from the optical readout is found
to present a fundamental limit to the frequency stability. Finally, for
closed-loop measurements, the response time is shown to no longer be
intrinsically limited but instead given by the bandwidth of the closed-loop
tracking system. Computed Allan deviations based on theory are given as well
and found to agree well with the measurements. These results are of importance
for the understanding of fundamental limitations of high-$Q$ resonators and
their application as high performance sensors.",2009.12331v1
2020-11-03,Nesting and Degeneracy of Mie Resonances of Dielectric Cavities within Zero-Index Materials,"Resonances in optical cavities have been used to manipulate light
propagation, enhance light-matter interaction, modulate quantum states, and so
on. However, in traditional cavities, the permittivity contrast in and out the
cavity is not so high. Recently, zero-index materials (ZIMs) with unique
properties and specific applications have attracted great interest. By putting
optical cavity into ZIMs, the extreme circumstance with infinite permittivity
contrast can be obtained. Here, we theoretically study Mie resonances of
dielectric cavities embedded in ZIMs with $\varepsilon \approx 0$, or $\mu
\approx 0$, or $(\varepsilon,\mu) \approx 0$. Owing to ultrahigh contrast ratio
of $\varepsilon$ or $\mu$ in and out the cavities, with fixed wavelength, a
series of Mie resonances with the same angular mode number $l$ but with
different cavity radii are obtained; more interestingly, its $2^l$-TM (TE) and
$2^{l+1}$-TE (TM) modes have the same resonant solution for the cavity in
$\varepsilon \approx 0$ ($\mu \approx 0$) material, and the resonance
degeneracy also occurs between $2^l$-TM mode and $2^l$-TE mode for
$(\varepsilon,\mu) \approx 0$ material. We further use resonance degeneracy to
modulate the Purcell effect of quantum emitter inside the cavity. The results
of resonance nesting and degeneracy will provide an additional view or freedom
to enhance the performance of cavity behaviors.",2011.01426v1
2020-11-11,Optimal Quantum Transfer from Input Flying Qubit to Lossy Quantum Memory,"In a quantum network, a key challenge is to minimize the direct reflection of
flying qubits as they couple to stationary, resonator-based memory qubits, as
the reflected amplitude represents state transfer infidelity that cannot be
directly recovered. Optimizing the transfer fidelity can be accomplished by
dynamically varying the resonator's coupling rate to the flying qubit field.
Here, we analytically derive the optimal coupling rate profile in the presence
of intrinsic loss of the quantum memory using an open quantum systems method
that can account for intrinsic resonator losses. We show that, since the
resonator field must be initially empty, an initial amplitude in the resonator
must be generated in order to cancel reflections via destructive interference;
moreover, we show that this initial amplitude can be made sufficiently small as
to allow the net infidelity throughout the complete transfer process to be
close to unity. We then derive the time-varying resonator coupling that
maximizes the state transfer fidelity as a function of the initial population
and intrinsic loss rate, providing a complete protocol for optimal quantum
state transfer between the flying qubit and resonator qubit. We present
analytical expressions and numerical examples of the fidelities for the
complete protocol using exponential and Gaussian profiles. We show that a state
transfer fidelity of around 99.9% can be reached for practical intrinsic losses
of resonators used as quantum memories.",2011.05667v1
2020-11-19,"Black-Box Coupled-Mode Theory: An Ab Initio Framework to Model Electromagnetic Interactions of Open, Lossy, and Dispersive Resonators","Temporal coupled-mode theory (TCMT) provides a simple yet powerful platform
to model and analyze electromagnetic resonator systems. Nevertheless,
restrictive assumptions and lack of rigorous connection to Maxwell's equations
limit the TCMT formulation's generality and robustness. Herein, we present the
Black-box Coupled-Mode Theory (BBCMT), a general ab initio CMT framework
developed from Maxwell's equations and quasinormal mode (QNM) theory to model
the electromagnetic interactions of dispersive, lossy, and open resonators.
BBCMT development is enabled by employing Poynting's and conjugated reciprocity
theorems to rigorously normalize QNMs and calculate their expansion
coefficients. Our novel QNM analysis approach allows the definition of a
resonator Hamiltonian matrix to characterize the modes' electromagnetic
interactions, energy storage, and absorption. Uniquely, the BBCMT framework can
capture a resonator's non-resonant scattering and absorption by treating the
resonator scattered fields as a perturbation to those of a background
structure, which can be flexibly chosen considering the desired
accuracy-simplicity trade-off. BBCMT modeling complexity can be further
adjusted by treating user-defined subcomponents of a resonator system as
black-boxes described only by their input-output transfer characteristics.
Beyond the BBCMT formulation, we present two lemmas to reverse-engineer the
modeling parameters from calculated or measured far-field spectra. Moreover, we
introduce the signal flow graphs from control theory to illustrate, interpret,
and solve the BBCMT equations. To evince BBCMT's validity and generality, we
compare the BBCMT and TCMT predictions for two plasmonic nanoresonator systems
to finite-difference time-domain simulations and find BBCMT results to be a
much better match. BBCMT reduces to TCMT or cavity perturbation theory under
certain constraints and approximations.",2011.10035v1
2021-02-06,Notes on relaxation of the resonant model using a scattering approach,"Here we consider a non-perturbative description of the non-interacting
resonant model using a scattering approach employed in JCP 152(24) 244126
(2020). We showed that such description coincides with the standard NEGF and
Landauer-Buttiker approaches.",2102.03685v1
2021-02-07,Observational Signatures of Tightly Wound Spirals Driven by Buoyancy Resonances in Protoplanetary Disks,"Besides the spirals induced by the Lindblad resonances, planets can generate
a family of tightly wound spirals through buoyancy resonances. The excitation
of buoyancy resonances depends on the thermal relaxation timescale of the gas.
By computing timescales of various processes associated with thermal
relaxation, namely, radiation, diffusion, and gas-dust collision, we show that
the thermal relaxation in protoplanetary disks' surface layers
($Z/R\gtrsim0.1$) and outer disks ($R\gtrsim100$ au) is limited by infrequent
gas-dust collisions. The use of isothermal equation of state or rapid cooling,
common in protoplanetary disk simulations, is therefore not justified. Using
three-dimensional hydrodynamic simulations, we show that the collision-limited
slow thermal relaxation provides favorable conditions for buoyancy resonances
to develop. Buoyancy resonances produce predominantly vertical motions, whose
magnitude at the $^{12}$CO emission surface is of order of $100~{\rm m~s}^{-1}$
for Jovian-mass planets, sufficiently large to detect using molecular line
observations with ALMA. We generate synthetic observations and describe
characteristic features of buoyancy resonances in Keplerian-subtracted moment
maps and velocity channel maps. Based on the morphology and magnitude of the
perturbation, we propose that the tightly wound spirals observed in TW Hya
could be driven by a (sub-)Jovian-mass planet at 90 au. We discuss how
non-Keplerian motions driven by buoyancy resonances can be distinguished from
those driven by other origins. We argue that observations of multiple lines
tracing different heights, with sufficiently high spatial/spectral resolution
and sensitivity to separate the emission arising from the near and far sides of
the disk, will help constrain the origin of non-Keplerian motions.",2102.03899v1
2021-03-10,Assessing the impact of transient orbital resonances,"One of the primary sources for the future space-based gravitational wave
detector, the Laser Interferometer Space Antenna, are the inspirals of small
compact objects into massive black holes in the centres of galaxies. The
gravitational waveforms from such Extreme Mass Ratio Inspiral (EMRI) systems
will provide measurements of their parameters with unprecedented precision, but
only if the waveforms are accurately modeled. Here we explore the impact of
transient orbital resonances which occur when the ratio of radial and polar
frequencies is a rational number. We introduce a new Effective Resonance Model,
which is an extension of the numerical kludge EMRI waveform approximation to
include the effect of resonances, and use it to explore the impact of
resonances on EMRI parameter estimation. For one-year inspirals, we find that
the few cycle dephasings induced by 3:2 resonances can lead to systematic
errors in parameter estimates, that are up to several times the typical
measurement precision of the parameters. The bias is greatest for 3:2
resonances that occur closer to the central black hole. By regarding them as
unknown model parameters, we further show that observations will be able to
constrain the size of the changes in the orbital parameters across the
resonance to a relative precision of 10% for a typical one-year EMRI
observation with signal-to-noise ratio of 20. Such measurements can be regarded
as tests of fundamental physics, by comparing the measured changes to those
predicted in general relativity.",2103.06306v2
2021-03-26,Microwave resonances of magnetic skyrmions in thin film multilayers,"Non-collinear magnets exhibit a rich array of dynamic properties at microwave
frequencies. They can host nanometre-scale topological textures known as
skyrmions, whose spin resonances are expected to be highly sensitive to their
local magnetic environment. Here, we report a magnetic resonance study of an
[Ir/Fe/Co/Pt] multilayer hosting N\'eel skyrmions at room temperature.
Experiments reveal two distinct resonances of the skyrmion phase during
in-plane ac excitation, with frequencies between 6-12 GHz. Complementary
micromagnetic simulations indicate that the net magnetic dipole moment rotates
counterclockwise (CCW) during both resonances. The magnon probability
distribution for the lower-frequency resonance is localised within isolated
skyrmions, unlike the higher-frequency mode which principally originates from
areas between skyrmions. However, the properties of both modes depend
sensitively on the out-of-plane dipolar coupling, which is controlled via the
ferromagnetic layer spacing in our heterostructures. The gyrations of stable
isolated skyrmions reported in this room temperature study encourage the
development of new material platforms and applications based on skyrmion
resonances. Moreover, our material architecture enables the resonance spectra
to be tuned, thus extending the functionality of such applications over a
broadband frequency range.",2103.14524v1
2021-03-29,Ultra-coherent nanomechanical resonators based on inverse design,"Engineered micro- and nanomechanical resonators with ultra-low dissipation
constitute the ideal systems for applications ranging from high-precision
sensing such as magnetic resonance force microscopy, to quantum transduction
between disparate quantum systems. Traditionally, the improvement of the
resonator's performance - often quantified by its Qf product (where Q is
quality factor and f is frequency) - through nanomechanical engineering such as
dissipation dilution and strain engineering, has been driven by human intuition
and insight. Such an approach is inefficient and leaves aside a plethora of
unexplored mechanical designs that potentially achieve better performance.
Here, we use a computer-aided inverse design approach known as topology
optimization to structurally design mechanical resonators with optimal
performance of the fundamental mechanical mode. Using the outcomes of this
approach, we fabricate and characterize ultra-coherent nanomechanical
resonators with record-high Qf products, entering a quantum coherent regime
where coherent oscillations are observed at room temperature. Further
refinements to the model describing the mechanical system are likely to improve
the Qf product even more. The proposed approach - which can be also used to
improve phononic crystal and coupled-mode resonators - opens up a new paradigm
for designing ultra-coherent micro- and nanomechanical resonators for
cutting-edge technology, enabling e.g. novel experiments in fundamental physics
(e.g. search for dark matter and quantum nature of gravity) and extreme sensing
of magnetic fields, electric fields and mass with unprecedented sensitivities
at room temperature.",2103.15601v1
2021-05-10,Universal coupler for bulk whispering gallery mode resonators based on silicon subwavelength grating waveguides,"Optical microresonators are of paramount importance in photonic circuits
requiring fine spectral filtering or resonant light recirculation. Key
performance metrics improve with increasing resonance quality factor (Q) across
all applications. The performance of silicon photonic circuits is often
hampered by the low-quality factor of planar silicon microresonators, typically
of Q~10^4-10^5. On the other hand, bulk whispering gallery mode resonators
provide a wide range of materials with intriguing optical properties and
exceptionally high resonant quality factors Q>10^7. However, the efficient
coupling between bulk resonators and planar Si photonic waveguides is
considered challenging, if not impossible, due to remarkably large mismatch in
size and refractive index. Here, we show an efficient method to couple bulk
resonators and Si waveguides based on subwavelength metamaterial engineering of
silicon. Based on this approach, we experimentally demonstrate coupling between
220-nm-thick Si waveguides and bulk microresonators made of silica, lithium
niobate and calcium fluoride with diameters in the 0.3-3.5 mm range, achieving
high coupling efficiency of 75-99% and exceptional Q of 10^6-10^7. These
results open a new route for the heterogeneous integration of bulk resonators
and silicon photonic circuits, with great potential for applications in
sensing, microwave-photonics, and quantum photonics, to name a few.",2105.04626v1
2021-06-08,"Superconducting microresonators for electron spin resonance, the good, the bad, and the future","The field of electron spin resonance is in constant need to improve its
capabilities. Among other things, this means having better resonators which
would provide improved spin sensitivity, as well as enable larger microwave
magnetic field power conversion factors. Surface micro resonators, made of
small metallic patches on a dielectric substrate, provide very good absolute
spin sensitivity and high conversion factors due to their very small mode
volume. However, such resonators suffer from having a relatively low quality
factor, which offsets some of their significant potential advantages. The use
of superconducting patches to replace the metallic layer seems like a
reasonable and straightforward solution to the quality factor issue, at least
for measurements carried out at cryogenic temperatures. Nevertheless,
superconducting materials are not easily incorporated into setups requiring
high magnetic fields, due to electric current vortices generated in the
latter's surface. This makes the transition from normal conducing materials to
superconductors highly nontrivial. Here we present the design, fabrication, and
testing results of surface micro resonators made of yttrium barium copper oxide
(YBCO) superconducting material. We show that with a unique experimental setup,
these resonators can be made to operate well even at high fields of about 1.2
T. Furthermore, we analyze the effect of current vortices on the ESR signal and
the spins' coherence times. Finally, we provide a head to head comparison of
YBCO vs copper resonators of the same dimensions, which clearly shows their
pros and cons and directs us to future potential developments and improvements
in this field.",2106.04163v2
2021-06-21,The chemical effect goes resonant -- a full quantum mechanical approach on TERS,"Lately, experimental evidence of unexpectedly extremely high spatial
resolution of tip-enhanced Raman scattering (TERS) has been demonstrated.
Theoretically, two different contributions are discussed: an electromagnetic
effect, leading to a spatially confined near field due to plasmonic
excitations; and the so-called chemical effect originating from the locally
modified electronic structure of the molecule due to the close proximity of the
plasmonic system. Most of the theoretical efforts have concentrated on the
electromagnetic contribution or the chemical effect in case of non-resonant
excitation. In this work, we present a fully quantum mechanical description
including non-resonant and resonant chemical contributions as well as
charge-transfer phenomena of these molecular-plasmonic hybrid system at the
density functional and the time-dependent density functional level of theory.
We consider a surface-immobilized tin(II) phthalocyanine molecule as the
molecular system, which is minutely scanned by a plasmonic tip, modeled by a
single silver atom. These different relative positions of the Ag atom to the
molecule lead to pronounced alterations of the Raman spectra. These Raman
spectra vary substantially, both in peak positions and several orders of
magnitude in the intensity patterns under non-resonant and resonant conditions,
and also, depending on, which electronic states are addressed. Our
computational approach reveals that unique - non-resonant and resonant -
chemical interactions among the tip and the molecule significantly alter the
TERS spectra and are mainly responsible for the high, possibly sub-Angstrom
spatial resolution.",2106.11065v1
2021-07-18,"Widening, Transition and Coalescence of Local Resonance Band Gaps in Multi-resonator Acoustic Metamaterials: From Unit Cells to Finite Chains","Local resonance band gaps in acoustic metamaterials are widely known for
their strong attenuation yet narrow frequency span. The latter limits the
practical ability to implement subwavelength band gaps for broadband
attenuation and has motivated novel metamaterial designs in recent years. In
this paper, we investigate the behavior of acoustic metamaterials where unit
cells house multiple resonating elements stacked in different configurations,
aimed at instigating a wide array of wave propagation profiles that are
otherwise unattainable. The dispersion mechanics of the multi-resonator
metamaterials are developed using purely analytical expressions which depict
and explain the underlying dynamics of such systems both at the unit cell level
as well as the frequency response of their finite realizations. The framework
reveals the mechanism behind the transition of the lower and upper band gap
bounds in metamaterials with parallel resonators resulting in a significant
band gap widening. The analysis also illustrates the ability of metamaterials
with dual-periodic super cells to exhibit a range of dispersion transitions
culminating in collapsing solutions of acoustic and optic bands, enabling a
coalescence of local resonance band gaps, vanishing resonances, and a number of
intriguing scenarios in between.",2107.08431v4
2021-07-26,Local resonances and parametric level dynamics in the many-body localised phase,"By varying the disorder realisation in the many-body localised (MBL) phase,
we investigate the influence of resonances on spectral properties. The standard
theory of the MBL phase is based on the existence of local integrals of motion
(LIOM), and eigenstates of the time evolution operator can be described as LIOM
configurations. We show that smooth variations of the disorder give rise to
avoided level crossings, and we identify these with resonances between LIOM
configurations. Through this parametric approach, we develop a theory for
resonances in terms of standard properties of non-resonant LIOM. This framework
describes resonances that are locally pairwise, and is appropriate in
arbitrarily large systems deep within the MBL phase. We show that resonances
are associated with large level curvatures on paths through the ensemble of
disorder realisations, and we determine the curvature distribution. By
considering the level repulsion associated with resonances we calculate the
two-point correlator of the level density. We also find the distributions of
matrix elements of local observables and discuss implications for low-frequency
dynamics.",2107.12387v2
2022-01-14,Topological Supercavity Resonances In the Finite System,"Acoustic resonant cavities play a vital role in modern acoustical systems.
They have led to many essential applications for noise control, biomedical
ultrasonics, and underwater communications. The ultrahigh quality-factor
resonances are highly desired for some applications like high-resolution
acoustic sensors and acoustic lasers. Here, we theoretically propose and
experimentally demonstrate a new class of supercavity resonances in a coupled
acoustic resonators system, arising from the merged bound states in the
continuum (BICs) in geometry space. We demonstrate their topological origin by
explicitly calculating their topological charges before and after BIC merging,
accompanied by charges annihilation. Comparing with other types of BICs, they
are robust to the perturbation brought by fabrication imperfection. Moreover,
we found that such supercavity modes can be linked with the Friedrich-Wintgen
BICs supported by an entire rectangular (cuboid) resonator sandwiched between
two rectangular (or circular) waveguides, and thus more supercavity modes are
constructed. Then, we fabricate these coupled resonators and experimentally
confirm such a unique phenomenon: moving, merging, and vanishing of BICs by
measuring their reflection spectra, which show good agreement with the
numerical simulation and theoretical prediction of mode evolution. Finally,
given the similar wave nature of acoustic and electromagnetic waves, such
merged BICs also can be constructed in a coupled photonic resonator system. Our
results may find exciting applications in acoustic and photonics, such as
enhanced acoustic emission, filtering, and sensing.",2201.05324v1
2022-01-18,Machine learning prediction for mean motion resonance behaviour -- The planar case,"Most recently, machine learning has been used to study the dynamics of
integrable Hamiltonian systems and the chaotic 3-body problem. In this work, we
consider an intermediate case of regular motion in a non-integrable system: the
behaviour of objects in the 2:3 mean motion resonance with Neptune. We show
that, given initial data from a short 6250 yr numerical integration, the
best-trained artificial neural network (ANN) can predict the trajectories of
the 2:3 resonators over the subsequent 18750 yr evolution, covering a full
libration cycle over the combined time period. By comparing our ANN's
prediction of the resonant angle to the outcome of numerical integrations, the
former can predict the resonant angle with an accuracy as small as of a few
degrees only, while it has the advantage of considerably saving computational
time. More specifically, the trained ANN can effectively measure the resonant
amplitudes of the 2:3 resonators, and thus provides a fast approach that can
identify the resonant candidates. This may be helpful in classifying a huge
population of KBOs to be discovered in future surveys.",2201.06743v1
2022-02-23,Quarter-wave Resonator Based Tunable Coupler for Xmon Qubits,"We propose a scheme of tunable coupler based on quarter-wave resonator for
scalable quantum integrated circuits. The open end of the T-type resonator is
capacitively coupled to two Xmon qubits, while another end is an asymmetric
dc-SQUID which dominates the inductive energy of coupler resonator. The
dc-Current applied through the flux bias line could change the magnetic flux
inside the dc-SQUID, so the frequency of coupler resonator can be effectively
tuned and the qubit-qubit coupling can be totally switched off. As the increase
of junction asymmetry for the dc-SQUID, the coupling of SQUID's effective phase
difference and cavity modes become smaller at required working frequency regime
of coupler resonator, and this could reduce the descent of the resonator's
quality factor. The separation between two cross-capacitor can be larger with
help of transverses width of the T-shape resonator, and then the ZZ crosstalk
coupling can be effectively suppressed. The asymmetric dc-SQUID is about 5
millimeters away from the Xmon qubits and only needs a small current on the
flux bias line, which in principle creates less flux noises to superconducting
Xmon qubits.",2202.11594v3
2022-03-22,The current orbit of Methone (S/2004 S 1),"The Cassini spacecraft discovered many close-in small satellites in Saturnian
system, and several of them exhibit exotic orbital states due to interactions
with Mimas and the oblateness of the planet. This work is devoted to Methone,
which is currently involved in a 15:14 Mean-Motion Resonance with Mimas. We
give an in deep study the current orbit of Methone by analyzing and identifying
the short, resonant and long-term gravitational perturbations on its orbit. In
addition, we perform numerical integrations of full equations of motion of
ensembles of close-in small bodies orbiting the non-central field of Saturn.
Spectral analyses of the orbits and interpretation of them in dynamical maps
allow us to describe the orbit and the dynamics of Methone in view of resonant
and long-term dynamics.
  We show that the current geometric orbit of Methone is aligned with Mimas'
due to a forced resonant component in eccentricity, leading to simultaneous
oscillations of several critical angles of the expanded disturbing function.
Thus, we explain the simultaneous oscillations of four critical arguments
associated to the resonance.
  The mapping of the Mimas-Methone resonance shows that the domains of the
15:14 Mimas-Methone resonance are dominated by regular motions associated to
the Corotation resonance located at eccentricities lower than $\sim 0.015$ and
osculating semi-major axis in the interval 194,660-194,730 km. Methone is
currently located deeply within this site.",2203.11814v2
2022-03-24,The gravitational imprint of an interior-orbital resonance in Jupiter-Io,"At mid-mission perijove 17, NASA's Juno mission has revealed a $7\sigma$
discrepancy between Jupiter's observed high-degree tidal response and the
theoretical equilibrium tidal response, namely the Love number $k_{42}$. Here,
we propose an interpretation for this puzzling disagreement based on an
interior-orbital resonance between internal gravity waves trapped in Jupiter's
dilute core and the orbital motion of Io. We use simple Jupiter models to
calculate a fractional correction $\Delta k_{42}$ to the equilibrium tidal
response that comes from the dynamical tidal response of a $g$-mode trapped in
Jupiter's dilute core. Our results suggest that an extended dilute core
($r\gtrsim0.7R_J$) produces an interior-orbital resonance with Io that modifies
Jupiter's tidal response in $\Delta k_{42}\sim-11\%$, allowing us to fit Juno's
$k_{42}$. In our proposed self-consistent scenario, Jupiter's dilute core
evolves in resonant locking with Io's orbital migration, which allows the
interior-orbital resonance to persist over geological timescales. This scenario
requires a dilute core that becomes smoother or shrinks over time, together
with a $_4^2g_1$ mode ($\ell,m,n=4,2,1$) with resonant tidal dissipation
reaching $Q_4\sim1000$. Jupiter's dilute core evolution path and the
dissipation mechanism for the resonant $_4^2g_1$ mode are uncertain and
motivate future analysis. No other alternative exists so far to explain the
$7\sigma$ discrepancy in Juno $k_{42}$. Our proposed interior-orbital resonance
can be tested by Juno observations of $k_{42}$ tides raised on Jupiter by
Europa as obtained at the end of the extended mission (mid 2025), and by future
seismological observations of Jupiter's $_4^2g_1$ mode oscillation frequency.",2203.13175v1
2022-04-04,"Quantum dimer model on fullerenes: resonance, scarring and confinement","The earliest known examples of quantum superposition were found in organic
chemistry -- in molecules that `resonate' among multiple arrangements of
$\pi$-bonds. Small molecules such as benzene resonate among a few bond
arrangements. In contrast, a large system that stretches over a macroscopic
lattice may resonate among an extensive number of configurations. This is
analogous to a quantum spin liquid as described by Anderson's resonating
valence bond (RVB) picture. In this article, we study the intermediate case of
somewhat large molecules, the C$_{20}$ and C$_{60}$ fullerenes. We build a
minimal description in terms of quantum dimer models, allowing for local
resonance processes and repulsion between proximate $\pi$-bonds. This allows us
to characterize ground-states, e.g., with C$_{60}$ forming a superposition of
5828 dimer covers. Despite the large number of contributing dimer covers, the
ground state shows strong dimer-dimer correlations. Going beyond the ground
state, the full spectrum of C$_{60}$ shows many interesting features. Its
Hilbert space is bipartite, leading to spectral reflection symmetry. It has a
large number of protected zero-energy states. In addition, the spectrum
contains many scar-like states, corresponding to localized
dimer-rearrangement-dynamics. Resonance dynamics in QDMs can manifest in the
behaviour of defects, potentially binding defects via an effective attractive
interaction. To test this notion, we introduce pairs of vacancies at all
possible separations. Resonance energy reaches its lowest value when the
vacancies are closest to one another. This suggests confinement of monomers,
albeit within a finite cluster. We discuss qualitative pictures for
understanding bonding in fullerenes and draw connections with results from
quantum chemistry.",2204.01756v1
2022-04-17,Dynamics of co-orbital exoplanets in a first order resonance chain with tidal dissipation,"Co-orbital planets (in a $1:1$ mean motion resonance) can be formed within a
Laplace resonance chain. Here, we develop a secular model to study the dynamics
of the resonance chain $p:p:p+1$, where the co-orbital pair is in a first-order
mean motion resonance with the outermost third planet. Our model takes into
account tidal dissipation through the use of a Hamiltonian version of the
constant time-lag model, which extends the Hamiltonian formalism of the
point-mass case. We show the existence of several families of equilibria, and
how these equilibria extend to the complete system. In one family, which we
call the main branch, a secular resonance between the libration frequency of
the co-orbitals and the precession frequency of the pericentres has unexpected
dynamical consequences when tidal dissipation is added. We report the existence
of two distinct mechanisms that make co-orbital planets much more stable within
the $p:p:p+1$ resonance chain rather than outside it. The first one is due to
negative real parts of the eigenvalues of the linearised system with tides, in
the region of the secular resonance mentioned above. The second one comes from
non-linear contributions of the vector field and it is due to eccentricity
damping. These two stabilising mechanisms increase the chances of a
still-to-come detection of exoplanets in the co-orbital configuration.",2204.08074v1
2022-04-19,OSSOS XXV: Large Populations and Scattering-Sticking in the Distant Transneptunian Resonances,"There have been 77 TNOs discovered to be librating in the distant
transneptunian resonances (beyond the 2:1 resonance, at semimajor axes greater
than 47.7~AU) in four well-characterized surveys: the Outer Solar System
Origins Survey (OSSOS) and three similar prior surveys. Here we use the OSSOS
Survey Simulator to measure their intrinsic orbital distributions using an
empirical parameterized model. Because many of the resonances had only one or
very few detections, $j$:$k$ resonant objects were grouped by $k$ in order to
have a better basis for comparison between models and reality. We also use the
Survey Simulator to constrain their absolute populations, finding that they are
much larger than predicted by any published Neptune migration model to date; we
also find population ratios that are inconsistent with published models,
presenting a challenge for future Kuiper Belt emplacement models. The estimated
population ratios between these resonances are largely consistent with
scattering-sticking predictions, though further discoveries of resonant TNOs
with high-precision orbits will be needed to determine whether
scattering-sticking can explain the entire distant resonant population or not.",2204.09139v1
2022-05-02,Regarding the possibility to observe the LHCb hidden-charm strange pentaquark $P_{cs}(4459)^0$ in antikaon-induced $J/ψ$ meson production on protons and nuclei near the $J/ψ$$Λ$ production threshold,"We study the near-threshold $J/\psi$ meson production on protons and nuclei
by considering incoherent direct non-resonant $K^-p \to {J/\psi}\Lambda$ and
two-step resonant ${K^-}p \to P_{cs}(4459)^0 \to {J/\psi}\Lambda$ charmonium
production processes. We calculate the absolute excitation functions, energy
and momentum distributions for the non-resonant, resonant and for the combined
(non-resonant plus resonant) production of $J/\psi$ mesons off protons as well
as off carbon and tungsten target nuclei at near-threshold incident antikaon
energies by considering these elementary production channels as well as by
assuming the spin-parity assignment of the hidden-charm resonance
$P_{cs}(4459)^0$ with strangeness as $J^P=(3/2)^-$ within six different
scenarios for the branching ratio $Br[P_{cs}(4459)^0 \to {J/\psi}\Lambda]$ of
the decay $P_{cs}(4459)^0 \to {J/\psi}\Lambda$. We show that the combined
observables considered reveal definite sensitivity to these scenarios, which
means that they may be an important tool to provide further evidence for the
existence of the pentaquark $P_{cs}(4459)^0$ resonance and to get valuable
information on its decay rate to the ${J/\psi}\Lambda$ final state. Their
measurements could be performed in the future at the J-PARC Hadron Experimental
Facility.",2205.00728v1
2022-06-02,Proximity of exoplanets to first-order mean-motion resonances,"Planetary formation theories and, more specifically, migration models predict
that planets can be captured in mean-motion resonances (MMRs) during the disc
phase. The distribution of period ratios between adjacent planets shows an
accumulation in the vicinity of the resonance, which is not centred on the
nominal resonance but instead presents an offset slightly exterior to it. Here
we extend on previous works by thoroughly exploring the effect of different
disc and planet parameters on the resonance offset during the disc migration
phase. The dynamical study is carried out for several first-order MMRs and for
both low-mass Earth-like planets undergoing type-I migration and giant planets
evolving under type-II migration. We find that the offset varies with time
during the migration of the two-planet system along the apsidal corotation
resonance family. The departure from the nominal resonance increases for higher
planetary masses and stronger eccentricity damping. In the Earth to super-Earth
regime, we find offset values in agreement with the observations when using a
sophisticated modelling for the planet-disc interactions, where the damping
timescale depends on the eccentricity. This dependence causes a feedback which
induces an increase of the resonance offsets. Regarding giant planets, the
offsets of detected planet pairs are well reproduced with a classical
$K$-factor prescription for the planet-disc interactions when the eccentricity
damping rate remains low to moderate. In both regimes, eccentricities are in
agreement with the observations too. As a result, planet-disc interactions
provide a generic channel to generate the offsets found in the observations.",2206.00943v1
2022-06-20,Parametrically-driven temporal cavity solitons in a bichromatically-driven pure Kerr resonator,"Temporal cavity solitons (CSs) are pulses of light that can persist endlessly
in dispersive, nonlinear optical resonators. They have been extensively studied
in the context of resonators with purely cubic (Kerr-type) nonlinearity that
are externally-driven with a monochromatic continuous wave laser -- in such
systems, the solitons manifest themselves as unique attractors whose carrier
frequency coincides with that of the external driving field. Recent experiments
have, however, shown that a qualitatively different type of temporal CS can
arise via parametric down-conversion in resonators with simultaneous quadratic
and cubic nonlinearity. In contrast to conventional CSs in pure-Kerr
resonators, these \emph{parametrically-driven cavity solitons} come in two
different flavours with opposite phases, and they are spectrally centred at
half of the frequency of the driving field. Here, we theoretically and
numerically show that, under conditions of bichromatic driving, such
parametrically-driven CSs can also arise in dispersive resonators with pure
Kerr nonlinearity. In this case, the solitons arise through parametric
four-wave mixing, come with two distinct phases, and have a carrier frequency
in between the two external driving fields. We show that, when all waves are
resonant, the solitons can experience long-range interactions due to their
back-action on the intracavity fields at the pump frequencies, and we discuss
the parameter requirements for the solitons' existence. Besides underlining the
possibility of exciting a new type of cavity soliton in dispersive Kerr
cavities, our work advances the theoretical modeling of resonators that are
coherently-driven with polychromatic fields.",2206.09533v1
2022-08-10,Inferred Properties of Planets in Mean-Motion Resonances are Biased by Measurement Noise,"Planetary systems with mean-motion resonances (MMRs) hold special value in
terms of their dynamical complexity and their capacity to constrain planet
formation and migration histories. The key towards making these connections,
however, is to have a reliable characterization of the resonant dynamics,
especially the so-called ""libration amplitude"", which qualitatively measures
how deep the system is into the resonance. In this work, we identify an
important complication with the interpretation of libration amplitude estimates
from observational data of resonant systems. Specifically, we show that
measurement noise causes inferences of the libration amplitude to be
systematically biased to larger values, with noisier data yielding a larger
bias. We demonstrated this through multiple approaches, including using
dynamical fits of synthetic radial velocity data to explore how the the
libration amplitude distribution inferred from the posterior parameter
distribution varies with the degree of measurement noise. We find that even
modest levels of noise still result in a slight bias. The origin of the bias
stems from the topology of the resonant phase space and the fact that the
available phase space volume increases non-uniformly with increasing libration
amplitude. We highlight strategies for mitigating the bias through the usage of
particular priors. Our results imply that many known resonant systems are
likely deeper in resonance than previously appreciated.",2208.05423v1
2022-08-14,Distributions of resonances of supercritical quasi-periodic operators,"We discover that the distribution of (frequency and phase) resonances plays a
role in determining the spectral type of supercritical quasi-periodic
Schr\""odinger operators. In particular, we disprove the second spectral
transition line conjecture of Jitomirskaya in the early 1990s.",2208.06944v1
2022-09-20,Dispersive cavity-mediated quantum gate between driven dot-donor nuclear spins,"Nuclear spins show exceptionally long coherence times but the underlying good
isolation from their environment is a challenge when it comes to controlling
nuclear spin qubits. A particular difficulty, not only for nuclear spin qubits,
is the realization of two-qubit gates between distant qubits. Recently, strong
coupling between an electron spin and microwave resonator photons as well as a
microwave resonator mediated coupling between two electron spins both in the
resonant and the dispersive regime have been reported and, thus, a microwave
resonator mediated electron spin two qubit gate seems to be in reach. Inspired
by these findings, we theoretically investigate the interaction of a microwave
resonator with a hybrid quantum dot-donor (QDD) system consisting of a gate
defined Si QD and a laterally displaced $^{31}$P phosphorous donor atom
implanted in the Si host material. We find that driving the QDD system allows
to compensate the frequency mismatch between the donor nuclear spin splitting
in the MHz regime and typical superconducting resonator frequencies in the GHz
regime, and also enables an effective nuclear spin-photon coupling. While we
expect this coupling to be weak, we predict that coupling the nuclear spins of
two distant QDD systems dispersively to the microwave resonator allows the
implementation of a resonator mediated nuclear spin two-qubit
$\sqrt{i\mathrm{SWAP}}$ gate with a gate fidelity approaching $90\%$.",2209.10026v2
2022-10-24,Field-linked resonances of polar molecules,"Scattering resonances are an essential tool for controlling interactions of
ultracold atoms and molecules. However, conventional Feshbach scattering
resonances, which have been extensively studied in various platforms, are not
expected to exist in most ultracold polar molecules due to the fast loss that
occurs when two molecules approach at a close distance. Here, we demonstrate a
new type of scattering resonances that is universal for a wide range of polar
molecules. The so-called field-linked resonances occur in the scattering of
microwave-dressed molecules due to stable macroscopic tetramer states in the
intermolecular potential. We identify two resonances between ultracold
ground-state sodium-potassium molecules and use the microwave frequencies and
polarizations to tune the inelastic collision rate by three orders of
magnitude, from the unitary limit to well below the universal regime. The
field-linked resonance provides a tuning knob to independently control the
elastic contact interaction and the dipole-dipole interaction, which we observe
as a modification in the thermalization rate. Our result provides a general
strategy for resonant scattering between ultracold polar molecules, which paves
the way for realizing dipolar superfluids and molecular supersolids as well as
assembling ultracold polyatomic molecules.",2210.13324v1
2022-11-11,Mean motion resonance capture in the context of type-I migration,"Capture into mean motion resonance (MMR) is an important dynamical mechanism
as it shapes the final architecture of a planetary system. We simulate systems
of two or three planets undergoing migration with varied initial parameters
such as planetary mass and disk surface density and analyse the resulting
resonant chains. In contrast to previous studies, our results show that the
disk properties have the dominant impact on capture into mean motion resonance,
while the total planetary mass barely affects the final system configuration as
long as the planet does not open a gap in the disk. We confirm that the
adiabatic resonant capture is the correct framework to understand the
conditions leading to MMR formation, since its predictions are qualitatively
similar to the numerical results. However, we find that the eccentricity
damping can facilitate the capture in a given resonance. We find that under
typical disk conditions, planets tend to be captured into 2:1 or 3:2 MMRs,
which agrees well with the observed exoplanet MMRs. Our results predict two
categories of systems: those that have uniform chains of wide resonances (2:1
or 3:2 MMRs) and those that have a more compact inner pair than the outer pair
such as 4:3:2 chains. Both categories of resonant chains are present in
observed exoplanet systems. On the other hand, chains with a wider inner pair
than the outer one are very rare and emerge from stochastic capture. Our work
here can be used to link current configuration of exoplanetary systems to the
formation conditions within protoplanetary disks.",2211.06181v1
2022-11-28,Exciting the TTV Phases of Resonant Sub-Neptunes,"There are excesses of sub-Neptunes just wide of period commensurabilities
like the 3:2 and 2:1, and corresponding deficits narrow of them. Any theory
that explains this period ratio structure must also explain the strong transit
timing variations (TTVs) observed near resonance. Besides an amplitude and a
period, a sinusoidal TTV has a phase. Often overlooked, TTV phases are
effectively integration constants, encoding information about initial
conditions or the environment. Many TTVs near resonance exhibit non-zero
phases. This observation is surprising because dissipative processes that
capture planets into resonance also damp TTV phases to zero. We show how both
the period ratio structure and the non-zero TTV phases can be reproduced if
pairs of sub-Neptunes capture into resonance in a gas disc while accompanied by
a third eccentric non-resonant body. Convergent migration and eccentricity
damping by the disc drives pairs to orbital period ratios wide of
commensurability; then, after the disc clears, secular forcing by the third
body phase-shifts the TTVs. The scenario predicts that resonant planets are
apsidally aligned and possess eccentricities up to an order of magnitude larger
than previously thought.",2211.15701v2
2023-01-11,Traveling wave enantio-selective electron paramagnetic resonance,"We propose a novel method for enantio-selective electron paramagnetic
resonance spectroscopy based on magneto-chiral anisotropy. We calculate the
strength of this effect and propose a dedicated interferometer setup for its
observation.",2301.04755v1
2023-02-14,Generation of 10-m-lengthscale plasma columns by resonant and off-resonant laser pulses,"Creating extended, highly homogeneous plasma columns like that required by
plasma wakefield accelerators can be a challenge. We study the propagation of
ultra-short, TW power ionizing laser pulses in a 10-meter-long rubidium vapor
and the plasma columns they create. We perform experiments and numerical
simulations for pulses with 780 nm central wavelength, which is resonant with
the D$_2$ transition from the ground state of rubidium atoms, as well as for
pulses with 810 nm central wavelength, some distance from resonances. We
measure transmitted energy and transverse width of the pulse and use schlieren
imaging to probe the plasma column in the vapor close to the end of the vapor
source. We find, that resonant pulses are more confined in a transverse
direction by the interaction than off-resonant pulses are and that the plasma
channels they create are more sharply bounded. Off-resonant pulses leave a
wider layer of partially ionized atoms and thus lose more energy per unit
propagation distance. Using experimental data, we estimate the energy required
to generate a 20-meter-long plasma column and conclude that resonant pulses are
much more suitable for creating a long, homogeneous plasma.",2302.07038v2
2023-04-02,Resonant mechanisms that produce near-Sun asteroids,"All near-Earth asteroids (NEAs) that reach sufficiently small perihelion
distances will undergo a so-called super-catastrophic disruption. The
mechanisms causing such disruptions are currently unknown or, at least,
undetermined. To help guide theoretical and experimental work to understand the
disruption mechanism, we use numerical simulations of a synthetic NEA
population to identify the resonant mechanisms that are responsible for driving
NEAs close to the Sun, determine how these different mechanisms relate to their
dynamical lifetimes at small heliocentric distances and calculate the average
time they spend at different heliocentric distances. Typically, resonances
between NEAs and the terrestrial and giant planets are able to dramatically
reduce the perihelion distances of the former. We developed an algorithm that
scans the orbital evolution of asteroids and automatically identifies
occurrences of mean motion and secular resonances. We find that most near-Sun
asteroids are pushed to small perihelion distances by the 3:1J and 4:1J
mean-motion resonances with Jupiter, as well as the secular resonances v6,
v5,v3 and v4. The time-scale of the small-perihelion evolution is fastest for
the 4:1J, followed by the 3:1J, while v5 is the slowest.~7% of the test
asteroids were not trapped in a resonance during the latest stages of their
dynamical evolution, which suggests that the secular oscillation of the
eccentricity due to the Kozai mechanism, a planetary close encounter or a
resonance that we have not identified pushed them below the estimated average
disruption distance.",2304.00561v1
2023-04-04,The orbit of Aegaeon and the 7:6 Mimas-Aegaeon resonance,"Aegaeon (S/2008 S 1) is the last satellite discovered by the Cassini
spacecraft at the end of the 2000s. Like the satellites Methone and Anthe, it
is involved in mean motion resonance with the mid-sized Mimas. In this work, we
give a detailed analysis of the current orbit of Aegaeon identifying the
resonant, secular and long-term perturbations due to Mimas and the oblateness
of Saturn, and the effects of Tethys. For this task, we perform thousands of
numerical simulations of full equations of motion of ensembles of small bodies
representing clones of Aegaeon. We have mapped the domain of the 7:6
Mimas-Aegaeon resonance in the phase space of the semi-major axis and
eccentricity. It displays a large area dominated by regular motions associated
with the 7:6 corotation resonance surrounded by chaotic layers. Aegaeon is
currently located very close to the periodic orbit of the resonance, which
extends up to eccentricities $\sim0.025$ centered at semi-major axis
$\sim168,028$ km. We show that the current orbit of Aegaeon has an important
forced component in eccentricity due to the 7:6 resonance. The orbital
inclination of Aegaeon has a non-negligible forced value due to long-term
perturbations of Mimas. These two forced modes explain the complex perturbed
orbit of Aegaeon without requiring the co-existence of multiple resonances.",2304.01923v2
2023-04-21,Quasiparticle resonance in decay spectrum of unbound nuclei near neutron drip-line,"Background: The pairing correlation in weakly bound nuclei causes a mixing
among bound and unbound configurations. A remarkable consequence is emergence
of the quasiparticle resonance, which has been predicted with the coordinate
space Hartree-Fock-Bogoliubov (HFB) theory, but not yet observed
experimentally. Purpose: We discuss possible observation of quasiparticle
resonances in decay spectrum of unbound nuclei near the neutron drip-line. We
deal with an example of unbound nucleus ${}^{21}$C which disintegrates to
${}^{20}$C and a neutron. Method: We describe a scattering state consisting of
${}^{20}$C and a neutron in the framework of the HFB formalism. We assume that
a nucleon knockout reaction produces a doorway state of the decay, and we
evaluate the decay spectrum by taking an overlap of the doorway state and the
scattering state of ${}^{20}\mathrm{C}+n$. A numerical calculation was
performed with the Woods-Saxon potential and a density-dependent effective
pairing interaction. Results: We show that the quasiparticle resonance appears
as low-lying peaks in the decay spectrum of ${}^{21}$C. They originate from the
weakly bound single-neutron orbits $2s_{1/2}$ and $1d_{5/2}$, but emerge as
unbound resonant quasiparticle states under the influence of the neutron
pairing correlation. The resonance energy and the width of the calculated
quasiparticle resonances are consistent with an experimental observation
whereas they are sensitive to the neutron pairing correlation. Conclusion: The
results suggest that nucleon knockout reactions populating the unbound nucleus
${}^{21}\mathrm{C}$ provide realistic opportunity of experimentally observing
the quasiparticle resonance and of disclosing the pairing correlation in
neutron-rich nuclei.",2304.10787v1
2023-05-07,Photocatalytic oxidation in few-layer Tellurene for loss-invariant integrated photonic resonance trimming,"Two-dimensional materials with unique physicochemical properties promote
photocatalytic activities. As the 2D material composites research studies the
statistical average of complex catalytic behaviors, an integrated photonic
platform allows clean and single flake level photo-catalytic investigations
with precisely quantified photocatalytic activities. In this paper, we track
fluence-dependent photo-oxidation in two-dimensional Tellurene (2D Te) by the
evanescently coupled micro-resonator. Nearly 32 perent of oxidation is achieved
in 10 nm 2D Te flake, compared to only 4.5% oxidation in 30 nm sample, probed
by the resonance shift in silicon microring resonators (MRRs) substrate. The
wider bandgap in the few layers of 2D Te allows faster charge transfer to
adsorbed oxygen for a more efficient photocatalytic redox reaction. The
photo-oxidation in hybrid 2D Te results in an invariant lineshapes of optical
transmission resonance for wavelength trimming (more than 3 times resonance
bandwidth). The low threshold power, near-infrared, and in-waveguide resonance
trimming scheme is compatible with most integrated photonic setups for easy
fixing the nanofabrication-induced random resonance deviation for integrated
photonic circuit applications in wavelength-division-multiplexing systems and
spin qubits quantum computing.",2305.04342v1
2023-06-02,Validating an algebraic approach to characterizing resonator networks,"Resonator networks are ubiquitous in natural and engineered systems, such as
solid-state materials, neural tissue, and electrical circuits. To understand
and manipulate these networks, it is essential to characterize their building
blocks, which include the mechanical analogs of mass, elasticity, damping, and
coupling of each resonator element. While these mechanical parameters are
typically obtained from response spectra using least-squares fitting, this
approach requires a priori knowledge of all parameters and is susceptible to
large error due to convergence to local minima. Here we validate an alternative
algebraic means to characterize resonator networks with no or minimal a priori
knowledge. Our approach recasts the equations of motion of the network into a
linear homogeneous algebraic equation and solves the equation with a set of
discrete measured network response vectors. For validation, we employ our
approach on noisy simulated data from a single resonator and a coupled
resonator pair, and we characterize the accuracy of the recovered parameters
using high-dimension factorial simulations. Generally, we find that the error
is inversely proportional to the signal-to-noise ratio, that measurements at
two frequencies are sufficient to recover all parameters, and that sampling
near the resonant peaks is optimal. Our simple, powerful tool will enable
future efforts to ascertain network properties and control resonator networks.",2306.01556v1
2023-07-28,Spectral tuning of high-harmonic generation with resonance-gradient metasurfaces,"High-index dielectric subwavelength structures and metasurfaces are capable
of enhancing light-matter interaction by orders of magnitude via
geometry-dependent optical resonances. This enhancement, however, comes with a
fundamental limitation of a narrow spectral range of operation in the vicinity
of one or few resonant frequencies. Here we tackle this limitation and
introduce an innovative and practical approach to achieve spectrally tunable
enhancement of light-matter interaction with resonant metasurfaces. We design
and fabricate {\it resonance-gradient metasurfaces} with varying geometrical
parameters that translate into resonant frequencies dependence on one of the
coordinates of the metasurface. The metasurfaces are composed of bone-like
nanoresonators which are made of germanium, and they support high-$Q$ optical
resonances in the mid-IR spectral range. We apply this general concept to
observe the resonant enhancement of the $3^{\text{rd}}$ and $5^{\text{th}}$
harmonics generated from the gradient metasurfaces being used in conjunction
with a tunable excitation laser to provide a wide spectral coverage of
resonantly-enhanced tunable generation of multiple optical harmonics.",2307.15279v1
2023-10-16,Resonant Effects of a Bar on the Galactic Disk Kinematics Perpendicular to Its Plane,"Detailed analysis of kinematics of the Milky Way disk in the solar
neighborhood based on the GAIA DR3 catalog reveals the existence of
peculiarities in the stellar velocity distribution perpendicular to the
galactic plane. We study the influence of resonances -- the outer Lindblad
resonance and the outer vertical Lindblad resonance -- of a rotating bar with
stellar oscillations perpendicular to the plane of the disk, and their role in
shaping the spatial and the velocity distributions of stars. We find that the
$Z$ and $V_Z$ distributions of stars with respect to $L_Z$ are affected by the
outer Lindblad resonance. The existence of bar resonance with stellar
oscillations perpendicular to the plane of the disk is demonstrated for a long
(large semi-axis 5 kpc) and fast rotating bar with $\Omega_{b}= 60.0$
$km~s^{-1}~kpc^{-1}$. We show also that, in the model with the long and fast
rotating bar, some stars in the 2:1 OLR region deviate far from their original
places, entering the bar region. A combination of resonance excitation of
stellar motions at the 2:1 OLR region together with strong interaction of the
stars with the bar potential leads to the formation of the group of 'escapees',
i.e., stars that deviate in $R$ and $Z$ -- directions at large distances from
the resonance region. Simulations, however, do not demonstrate any noticeable
effect on $V_Z$-distribution of stars in the solar neighborhood",2310.10327v1
2023-11-02,Unstable capillary-gravity waves,"We make rigorous spectral stability analysis for non-resonant
capillary-gravity waves as well as resonant Wilton ripples of sufficiently
small amplitude. Our analysis is based on a periodic Evans function approach,
developed recently by the authors for Stokes waves. On top of our previous
work, we add to the approach new framework ingredients, including a two-stage
Weierstrass preparation manipulation for the Periodic Evans function associated
to the wave and the definition of a stability function as an analytic function
of the wave amplitude parameter. These new ingredients are keys for proving
stability near non-resonant frequencies and defining index functions ruling
both stability and instability near non-zero resonant frequencies. We also
prove that unstable bubble spectra near non-zero resonant frequencies form, at
the leading order, either an ellipse or a circle and provide a justification
for Creedon, Deconinck, and Trichtchenko's formal asymptotic expansion for the
Floquet exponent. For non-resonant capillary-gravity waves for the stability
near the origin of the complex plane, our stability results agree with the
prediction from formal multi-scale expansion. New are our stability results
near non-zero resonant frequencies. As the effects of surface tension vanish,
our result recovers that for gravity waves. Also new are our stability results
for Wilton ripples of small amplitude near the origin as well as near non-zero
resonant frequencies.",2311.01368v2
2023-11-29,Spin Dynamics of Planets in Resonant Chains,"About a dozen exoplanetary systems have been discovered with three or more
planets participating in a sequence of mean-motion resonances. The unique and
complex architectures of these so-called ""resonant chains"" motivate efforts to
characterize their planets holistically. In this work, we perform a
comprehensive exploration of the spin-axis dynamics of planets in resonant
chains. Planetary spin states are closely linked with atmospheric dynamics and
habitability and are thus especially relevant to resonant chains like
TRAPPIST-1, which hosts several temperate planets. Considering a set of
observed resonant chains, we calculate the equilibrium states of the planetary
axial tilts (""obliquities""). We show that high obliquity states exist for
$\sim60\%$ of planets in our sample, and many of these states can be stable in
the presence of tidal dissipation. Using case studies of two observed systems
(Kepler-223 and TOI-1136), we demonstrate how these high obliquity states could
have been attained during the initial epoch of disk-driven orbital migration
that established the resonant orbital architectures. We show that the
TRAPPIST-1 planets most likely have zero obliquities, with the possible
exception of planet d. Overall, our results highlight that both the orbital and
spin states of resonant chains are valuable relics of the early stages of
planet formation and evolution.",2311.17908v1
2002-03-26,The Effect of Vacuum Polarization and Proton Cyclotron Resonances on Photon Propagation in Strongly Magnetized Plasmas,"We consider the effects of vacuum polarization and proton cyclotron
resonances on the propagation of radiation through a strongly magnetized
plasma. We analyze the conditions under which the photons evolve adiabatically
through the resonant density and find that the adibaticity condition is
satisfied for most photon energies of interest, allowing for a normal-mode
treatment of the photon propagation. We then construct radiative equilibrium
atmosphere models of strongly magnetized neutron stars that includes these
effects, employing a new numerical method that resolves accurately the sharp
changes of the absorption and mode-coupling cross sections at the resonant
densities. We show that the resulting spectra are modified by both resonances
and are harder at all field strengths than a blackbody at the effective
temperature. We also show that the narrow absorption features introduced by the
proton cyclotron resonance have small equivalent widths. We discuss the
implications of our results for properties of thermal emission from the
surfaces of young neutron stars.",0203449v1
2002-04-04,Extrasolar Trojans: The Viability and Detectability of Planets in the 1:1 Resonance,"We explore the possibility that extrasolar planets might be found in the 1:1
mean-motion resonance. There are a variety of stable co-orbtial configurations,
and we specifically examine three different versions of the 1:1 resonance.
These include tadpole and horseshoe type orbits, as well as a more exotic
configuration which occurs when one planet has a highly eccentric orbit while
the other planet moves on a nearly circular orbit. We show that pairs of
planets in 1:1 resonance yield characteristic radial velocity signatures which
are not prone to the sin(i) degeneracy. Indeed, Keplerian fits to the radial
velocities cannot reveal the presence of two planets in the 1:1 resonance. We
discuss a dynamical fitting method for such systems, and illustrate its use
with a simulated data set. Finally, we argue that hydrodynamical simulations
and torqued three-body calculations indicate that 1:1 resonant pairs might
readily form and migrate within protostellar disks.",0204091v1
2003-02-12,X-ray absorption via K-alpha resonance complexes in oxygen ions,"The K-alpha resonance complexes in oxygen ions O I - O VI are theoretically
computed and resonance oscillator strengths and wavelengths are presented. The
highly resolved photoionization cross sections, with relativistic fine
structure, are computed in the coupled channel approximation using the
Breit-Pauli R-matrix method. A number of strong K-alpha resonances are found to
be appreciable, with resonance oscillator strengths f_r > 0.1. The K-alpha
resonance wavelengths of O I-O VI lie in a relatively narrow wavelength range
22 - 23.5 A, and the X-ray opacity in this region should therefore be
significantly affected by K --> L transitions in oxygen. The results should be
useful in the interpretation of soft X-ray spectra observed from Chandra and
XMM-Newton.",0302238v1
2004-08-04,Parametric resonance as a model for QPO sources -- I. A general approach to multiple scales,"In the resonance model, high-frequency quasi-periodic oscillations (QPOs) are
supposed to be a consequence of nonlinear resonance between modes of
oscillations occurring within the innermost parts of an accretion disk. Several
models with a prescribed mode--mode interaction were proposed in order to
explain the characteristic properties of the resonance in QPO sources. In this
paper, we examine nonlinear oscillations of a system having a quadratic
nonlinearity and we show that this case is particularly relevant for QPOs. We
present a very convenient way how to study internal resonances of a fully
general system using the method of multiple scales. Finally, we concentrate to
conservative systems and discuss their behavior near the 3:2 resonance.",0408092v1
2004-09-02,Excitation of Disk Oscillations by Warps: A Model of kHz QPOs,"The amplification of disk oscillations resulting from non-linear resonant
couplings between the oscillations and a warp is examined. The disks are
geometrically thin and general relativistic with non-rotating central objects.
By using a Lagrangian formulation, a general stability criterion is derived.
The criterion is applied to horizontal and vertical resonances of g-mode
oscillations and to horizontal resonances of p-mode oscillations. The results
of analyses show that g-mode oscillations (including p-mode oscillations of
$n=0$) are amplified by horizontal resonances with the warp. Other modes of
oscillations with other resonances are all damped by resonances. The amplified
g-mode oscillations are located around the radius $4r_{\rm g}$, the radius of
the epicyclic frequency being maximum, i.e., $\kappa_{\rm max}$. The
frequencies of amplified oscillations are harmonics of $\kappa_{\rm max}$, and
well explain the 2 : 3 pairs of observed QPOs for reasonable masses (and spins)
of the central objects.",0409051v2
2006-03-24,On the evolution of the resonant planetary system HD128311,"A significant number of the known multiple exoplanetary systems are
containing a pair of giant planets engaged in a low order mean motion
resonance. Such a resonant condition protects the dynamics of these planets
resulting in very stable orbits. According to recent studies the capture into a
resonance is the result of a planetary migration process induced by the
interaction of the planets with a protoplanetary disk. If the migration is slow
enough (adiabatic) next to a mean motion resonance, the two planets will also
be in apsidal corotation.
  The recently refined orbital parameters of the system HD 128311 suggest that
the two giant planets are in a 2:1 mean motion resonance, however without
exhibiting apsidal corotation. Thus the evolution of this system can not be
described by an adiabatic migration process alone.
  We present possible evolution scenarios of this system combining migration
processes and sudden perturbations. We model migration scenarios through
numerical integration of the gravitational N-body problem with additional
non-conservative forces. Planet-planet scattering has been investigated by
N-body simulations.
  We show that the present dynamical state of the system HD128311 may be
explained by such evolutionary processes.",0603664v2
2006-10-23,A Possible Correlation between the Gaseous Drag Strength and Resonant Planetesimals in Planetary Systems,"We study the migration and resonant capture of planetesimals in a planetary
system consisting of a gaseous disc analogous to the primordial solar nebula
and a Neptune-like planet. Using a simple treatment of the drag force we find
that planetesimals are mainly trapped in the 3:2 and 2:1 resonances and that
the resonant populations are correlated with the gaseous drag strength in a
sense that the 3:2 resonant population increases with the stronger gaseous
drag, but the 2:1 resonant population does not. Since planetesimals can lead to
the formation of larger bodies similar to asteroids and Kuiper Belt Objects,
the gaseous drag can play an important role in the configuration of a planetary
system.",0610668v1
2006-11-06,The Shadow of Dark Matter,"We carry out a model independent study of resonant photon scattering off dark
matter (DM) particles. The DM particle chi_1 can feature an electric or
magnetic transition dipole moment which couples it with photons and a heavier
neutral particle chi_2. Resonant photon scattering then takes place at a
special energy set by the masses of chi_1 and chi_2, with the width of the
resonance set by the size of the transition dipole moment. We compute the
constraints on the parameter space of the model from stellar energy losses,
data from SN 1987A, the Lyman-alpha forest, Big Bang nucleosynthesis,
electro-weak precision measurements and accelerator searches. We show that the
velocity broadening of the resonance plays an essential role for the
possibility of the detection of a spectral feature originating from resonant
photon-DM scattering. Depending upon the particle setup and the DM surface mass
density, the favored range of DM particle masses lies between tens of keV and a
few MeV, while the resonant photon absorption energy is predicted to be between
tens of keV and few GeV.",0611129v1
1997-04-17,Resonant Tunneling and Persistent Current of a Non-interacting and Weakly Interacting One-dimensional Electron Gas,"The persistent current for a one-dimensional ring with two tunnel barriers is
considered in the limit of weakly interacting electrons. In addition to a small
off-resonance current, there are two kinds of resonant behavior; (i) a current
independent of the barrier transparency (true resonance) and (ii) a current
analogous to the one for a ring with only a single barrier
(``semi''-resonance). For a given barrier transparency one or the other type of
resonant behavior is realized depending on a geometric factor (ratio of
interbarrier distance to ring circumference) and on the strength of the
electron-electron interaction. It is shown that a repulsive interaction favours
the``semi''-resonance behavior. For a small barrier transparency the
``semi''-resonance peaks are easily washed out by temperature whereas the true
resonance peaks survive.",9704151v1
1997-06-23,Resonant scattering in a strong magnetic field: exact density of states,"We study the structure of 2D electronic states in a strong magnetic field in
the presence of a large number of resonant scatterers. For an electron in the
lowest Landau level, we derive the exact density of states by mapping the
problem onto a zero-dimensional field-theoretical model. We demonstrate that
the interplay between resonant and non-resonant scattering leads to a
non-analytic energy dependence of the electron Green function. In particular,
for strong resonant scattering the density of states develops a gap in a finite
energy interval. The shape of the Landau level is shown to be very sensitive to
the distribution of resonant scatterers.",9706233v3
1998-05-27,Measurement of Resonant Frequency and Quality Factor of Microwave Resonators: Comparison of Methods,"Precise microwave measurements of sample conductivity, dielectric, and
magnetic properties are routinely performed with cavity perturbation
measurements. These methods require the accurate determination of quality
factor and resonant frequency of microwave resonators. Seven different methods
to determine the resonant frequency and quality factor from complex
transmission coefficient data are discussed and compared to find which is most
accurate and precise when tested using identical data. We find that the
nonlinear least-squares fit to the phase vs. frequency is the most accurate and
precise when the signal-to-noise ratio is greater than 65. For noisier data,
the nonlinear least squares fit to a Lorentzian curve is more accurate and
precise. The results are general and can be applied to the analysis of many
kinds of resonant phenomena.",9805365v1
1999-01-07,Strongly enhanced inelastic collisions in a Bose-Einstein condensate near Feshbach resonances,"The properties of Bose-Einstein condensed gases can be strongly altered by
tuning the external magnetic field near a Feshbach resonance. Feshbach
resonances affect elastic collisions and lead to the observed modification of
the scattering length. However, as we report here, this is accompanied by a
strong increase in the rate of inelastic collisions. The observed three-body
loss rate in a sodium Bose-Einstein condensation increased when the scattering
length was tuned to both larger or smaller values than the off-resonant value.
This observation and the maximum measured increase of the loss rate by several
orders of magnitude are not accounted for by theoretical treatments. The strong
losses impose severe limitations for using Feshbach resonances to tune the
properties of Bose-Einstein condensates. A new Feshbach resonance in sodium at
1195 G was observed.",9901056v1
2000-08-18,Entangled states in a Josephson charge qubit coupled to a superconducting resonator,"We study the dynamics of a quantum superconducting circuit which is the
analogue of an atom in a high-Q cavity. The circuit consists of a Josephson
charge qubit coupled to a superconducting resonator. The charge qubit can be
treated as a two level quantum system whose energy separation is split by the
Josephson energy $E_j$. The superconducting resonator in our proposal is the
analogue of a photon box and is described by a quantum harmonic oscillator with
characteristic frequency $\omega_r$. The coupling between the charge qubit and
the resonator is realized by a coupling capacitance $C_c$. We have studied the
eigenstates as well as the dynamics of the quantum circuit. Interesting
phenomena occur when the Josephson energy equals the oscillator frequency,
$E_j=\hbar\omega_r$. Then the quantum circuit is described by entangled states.
We have deduced the time evolution of these states in the limit of weak
coupling between the charge qubit and the resonator. We found Rabi oscillations
of the excited charge qubit eigenstate. This effect is explained by the
spontaneous emission and re-absorption of a single photon in the
superconducting resonator.",0008275v1
2000-11-16,Coherent stochastic resonance in one dimensional diffusion with one reflecting and one absorbing boundaries,"It is shown that the single-step periodic signal (periodic telegraph signal)
can not produce coherent stochastic resonance for diffusion on a segment with
one absorbing and one reflecting end points while the multi-step periodic
signal does. The general features of this process are exihibited. The resonant
frequency is found to decrease and the mean first passage time at resonant
frequency increases linearly, as we increase the length of the medium. The
cycle variable is shown to be the proper argument to express the first passage
time density function at resonance. A formula for first passage time density
function at resonance is derived in terms of two universal functions, which
clearly isolates its dependence on the length of the medium.",0011271v1
2000-12-06,Ab initio calculation of resonant X-ray scattering in Manganites,"We study the origin of the resonant x-ray signal in manganites and generalize
the resonant cross-section to the band structure framework. With {\it ab
initio} LSDA and LSDA+U calculations we determine the resonant x-ray spectrum
of LaMnO$_3$. The calculated spectrum and azimuthal angle dependence at the Mn
$K$-edge reproduce the measured data without adjustable parameters. The
intensity of this signal is directly related to the orthorhombicity of the
lattice. We also predict a resonant x-ray signal at the La $L$-edge, caused by
the tilting of the MnO$_6$ octahedra. This shows that the resonant x-ray signal
in the hard x-ray regime can be understood in terms of the band structure of a
material and is sensitive to the fine details of crystal structure.",0012084v1
2001-02-08,New selection rules for resonant Raman scattering on quantum wires,"The bosonisation technique is used to calculate the resonant Raman spectrum
of a quantum wire with two electronic sub-bands occupied. Close to resonance,
the cross section at frequencies in the region of the inter sub-band
transitions shows distinct peaks in parallel polarisation of the incident and
scattered light that are signature of collective higher order spin density
excitations. This is in striking contrast to the conventional selection rule
for non-resonant Raman scattering according to which spin modes can appear only
in perpendicular polarisation. We predict a new selection rule for the
excitations observed near resonance, namely that, apart from charge density
excitations, only spin modes with positive group velocities can appear as peaks
in the spectra in parallel configuration close to resonance. The results are
consistent with all of the presently available experimental data.",0102144v1
2001-10-19,Quantum resonances in a single plaquette of Josephson junctions: excitations of Rabi oscillations,"We present a theoretical study of a quantum regime of the resistive
(whirling) state of dc driven anisotropic single plaquette containing three
small Josephson junctions. The current-voltage characteristics of such a system
display resonant steps that are due to the resonant interaction between the
time dependent Josephson current and the excited electromagnetic oscillations
(EOs). The voltage positions of the resonances are determined by the quantum
interband transitions of EOs. We show that in the quantum regime as the system
is driven on the resonance, coherent Rabi oscillations between the quantum
levels of EOs occur. At variance with the classical regime the magnitude and
the width of resonances are determined by the frequency of Rabi oscillations
that in turn, depends in a peculiar manner on an externally applied magnetic
field and the parameters of the system.",0110414v1
2001-11-23,Incommensurate dynamics of resonant breathers in Josephson junction ladders,"We present theoretical and experimental studies of resonant localized
resistive states in a Josephson junction ladder. These complex breather states
are obtained by tuning the breather frequency into the upper band of linear
electromagnetic oscillations of the ladder. Their prominent feature is the
appearance of resonant steps in the current-voltage (I-V) characteristics. We
have found the resonant breather-like states displaying incommensurate
dynamics. Numerical simulations show that these incommensurate resonant
breathers persist for very low values of damping. Qualitatively similar
incommensurate breather states are observed in experiments performed with
Nb-based Josephson ladders. We explain the appearance of these states with the
help of resonance-induced hysteresis features in the I-V dependence.",0111460v1
2002-05-09,Microwave resonances of the bubble phases in 1/4 and 3/4 filled higher Landau levels,"We have measured the diagonal conductivity in the microwave regime of an
ultrahigh mobility two dimensional electron system. We find a sharp resonance
in Re[sigma_{xx}] versus frequency when nu > 4 and the partial filling of the
highest Landau level, nu^*, is ~ 1/4 or 3/4 and temperatures < 0.1 K. The
resonance appears for a range of nu^* from 0.20 to 0.37 and again from 0.62 to
0.82. the peak frequency, f_{pk} changes from ~ 500 to ~ 150 as nu^* = 1/2 is
approached. This range of f_{pk} shows no dependence on nu where the resonance
is observed. The quality factor, Q, of the resonance is maximum at ~ nu^* =
0.25 and 0.74. We interpret the resonance as due to a pinning mode of the
bubble phase crystal.",0205200v2
2003-05-21,Resonant Bose Condensate: Analog of Resonant Atom,"The resonant formation of nonlinear coherent modes in trapped Bose-Einstein
condensates is studied. These modes represent nonground-state Bose condensates.
The methods of describing the spectrum of the nonlinear modes are discussed.
The latter can be created by modulating the trapping potential with a frequency
tuned close to the transition frequency between the two chosen modes. The
requirement that the transition amplitudes be smaller than the transition
frequency implies a constraint on the number of particles that can be
transferred to an excited mode. The resonant Bose condensate serves as a
collective analog of a single resonant atom. Such a condensate, displaying the
coherent resonance, possesses several interesting features, among which are:
mode locking, critical dynamics, interference patterns, interference current,
atomic squeezing, and multiparticle entanglement.",0305495v1
2003-10-09,Ground state cooling of mechanical resonators,"We propose an application of a single Cooper pair box (Josephson qubit) for
active cooling of nanomechanical resonators. Latest experiments with Josephson
qubits demonstrated that long coherence time of the order of microsecond can be
achieved in special symmetry points. Here we show that this level of coherence
is sufficient to perform an analog of the well known in quantum optics
``laser'' cooling of a nanomechanical resonator capacitively coupled to the
qubit. By applying an AC driving to the qubit or the resonator, resonators with
frequency of order 100 MHz and quality factors higher than $10^3$ can be
efficiently cooled down to their ground state, while lower frequency resonators
can be cooled down to micro-Kelvin temperatures. We also consider an
alternative setup where DC-voltage-induced Josephson oscillations play the role
of the AC driving and show that cooling is possible in this case as well.",0310229v2
2003-10-29,Transverse laser modes in Bose-Einstein condensates,"We examine the Bose-Einstein-condensate (BEC) equivalent of transverse
aspects of laser resonators. We model numerically repeated focussing of a
2-dimensional BEC, which could be achieved in practice by a series of far
off-resonant light pulses. We show for a range of non-linear coefficients that
such a series of light pulses traps the BEC. We also model a combination of
repeated focussing and loss, which could be achieved with a series of light
pulses, some far off-resonant, some resonant. In analogy to light repeatedly
being focussed and locally absorbed by passing through a laser resonator, a
small proportion (in our model up to 10%) of the BEC is shaped into
Hermite-Gaussian-like modes; the remainder of the BEC is lost. This happens
irrespective of the presence of a harmonic trap. We show that astigmatic
focussing of the resulting Hermite-Gaussian-like modes, which can be achieved
by a pair of off-resonant light pulses, results in a specific number of
vortices.",0310702v1
2004-02-25,Local Geometry of the Fermi Surface and the Cyclotron Resonance in Metals in a Normal Magnetic Field,"In this paper we present a detailed theoretical analysis of the cyclotron
resonance in metals in the magnetic field directed along a normal to the
surface of a sample. We show that this resonance occurs due to local geometry
of the Fermi surface of a metal. When the Fermi surface (FS) includes segments
where its curvature turns zero or diverges, this could give rise to resonance
features in the frequency/magnetic field dependence of the surface impedance or
its derivative with respect to the field. Otherwise the resonance is scarcely
detectable unlike the well-known cyclotron resonance in a parallel magnetic
field. The proposed theory agrees with experimantal results concerning both
convenient and organic metals.",0402611v3
2004-05-20,Effect of impurity states on the NMR spectra of high-$T_c$ cuprates,"A strong nonmagnetic impurity can induce a resonance state in the d-wave
superconducting state. As far as magnetic properties are concerned, this
resonance state behaves effectively like a free moment. It leads to a
Curie-Weiss-like magnetic susceptibility in an intermediate temperature regime
below $T_{c}$. From the impurity susceptibility, the effective moment of the
resonance state is deduced and compared with experiments. The contribution of
the resonance to the magnetic susceptibility can account for the main feature
of the NMR spectra in overdoped high-$T_c$ materials. In the underdoped regime,
the contribution from the resonance to the magnetic susceptibility is also
substantial, but the effective moment of the resonance is smaller than the
total moment induced by a nonmagnetic impurity.",0405480v2
2004-09-10,Spectroscopy of Three-Particle Entanglement in a Macroscopic Superconducting Circuit,"We study the quantum mechanical behavior of a macroscopic, three-body,
superconducting circuit. Microwave spectroscopy on our system, a resonator
coupling two large Josephson junctions, produced complex energy spectra well
explained by quantum theory over a large frequency range. By tuning each
junction separately into resonance with the resonator, we first observe strong
coupling between each junction and the resonator. Bringing both junctions
together into resonance with the resonator, we find spectroscopic evidence for
entanglement between all three degrees of freedom and suggest a new method for
controllable coupling of distant qubits, a key step toward quantum computation.",0409284v2
2004-10-07,Boson-Fermion Resonance Model in One Dimension,"We discuss the BCS-BEC crossover for one-dimensional spin 1/2 fermions at
zero temperature using the Boson-Fermion resonance model in one dimension. We
show that in the limit of a broad resonance, this model is equivalent to an
exactly solvable single channel model, the so-called modified Gaudin-Yang
model. We argue that the one-dimensional crossover may be realized either via
the combination of a Feshbach resonance and a confinement induced resonance or
using direct photo-association in a two-component Fermi gas with effectively
one-dimensional dynamics. In both cases, the system may be driven from a
BCS-like state through a molecular Tonks-Girardeau gas close to resonance to a
weakly interacting Bose gas of dimers.",0410183v1
2005-02-11,Pulse Propagation in Resonant Tunneling II,"We consider the analytically solvable model of a Gaussian pulse tunneling
through a transmission resonance with a general Fano characteristic. It is
demonstrated that the transmitted pulse contains enough information to
determine uniquely all parameters defining the Fano resonance. This is in
contrast to the measurement of the static conductance. Our analytical model is
in agreement with numerical data published recently for the limit of a
Breit-Wigner resonance. We identify two opposite pulse propagation regimes: if
the resonance is broad compared to the energetic width of the incident Gaussian
pulse a weakly deformed and slightly delayed transmitted Gaussian pulse is
found. In the opposite limit of a narrow resonance the dying out of the
transmitted pulse is dominated by the slow exponential decay characteristic of
a quasi-bound state with a long life time. In this regime we find
characteristic interference oscillations.",0502286v1
2005-08-11,Effective potential for the second virial coefficient at Feshbach resonance,"In a recent paper entitled ""High temperature expansion applied to fermions
near Feshbach resonance"" (Phys. Rev. Lett. 92, 160404 (2004)), Ho and Muller
have demonstrated a remarkable similarity between its high and low temperature
properties at resonance. The quantum second virial coefficient plays a crucial
role in their analysis, and has a universal value at resonance. In this paper,
we explore the connection between the quantum and classical second virial
coefficients, and show that near a Feshbach resonance, an exact mapping from
the quantum to classical form is possible. This gives rise to a scale
independent inverse square potential for the classical second virial
coefficient. It is suggested that it may be tested by measuring the isothermal
compressibility of the gas on the repulsive side of the resonance.",0508290v1
2006-01-08,Nonlinear Dynamics in the Resonance Lineshape of NbN Superconducting Resonators,"In this work we report on unusual nonlinear dynamics measured in the
resonance response of NbN superconducting microwave resonators. The nonlinear
dynamics, occurring at relatively low input powers (2-4 orders of magnitude
lower than Nb), and which include among others, jumps in the resonance
lineshape, hysteresis loops changing direction and resonance frequency shift,
are measured herein using varying input power, applied magnetic field, white
noise and rapid frequency sweeps. Based on these measurement results, we
consider a hypothesis according to which local heating of weak links forming at
the boundaries of the NbN grains are responsible for the observed behavior, and
we show that most of the experimental results are qualitatively consistent with
such hypothesis.",0601146v1
2006-03-06,Coherent Signal Amplification in Bistable Nanomechanical Oscillators by Stochastic Resonance,"Stochastic resonance is a counter-intuitive concept[1,2], ; the addition of
noise to a noisy system induces coherent amplification of its response. First
suggested as a mechanism for the cyclic recurrence of ice ages, stochastic
resonance has been seen in a wide variety of macroscopic physical systems:
bistable ring lasers[3], SQUIDs[4,5], magnetoelastic ribbons[6], and
neurophysiological systems such as the receptors in crickets[7] and
crayfish[8]. Although it is fundamentally important as a mechanism of coherent
signal amplification, stochastic resonance is yet to be observed in nanoscale
systems. Here we report the observation of stochastic resonance in bistable
nanomechanical silicon oscillators, which can play an important role in the
realization of controllable high-speed nanomechanical memory cells. Our
nanomechanical systems were excited into a dynamic bistable state and modulated
in order to induce controllable switching; the addition of white noise showed a
marked amplification of the signal strength. Stochastic resonance in
nanomechanical systems paves the way for exploring macroscopic quantum
coherence and tunneling, and controlling nanoscale quantum systems for their
eventual use as robust quantum logic devices.",0603108v1
2006-09-10,Interaction-Induced Resonance in Conductance and Thermopower of Quantum Wires,"We study the effect of electron-electron interaction on the transport
properties of short clean quantum wires adiabatically connected to reservoirs.
Interactions lead to resonances in a multi-channel wire at particular values of
the Fermi energy. We investigate in detail the resonance in a two-channel wire.
The (negative) conductance correction peaks at the resonance, and decays
exponentially as the Fermi energy is tuned away; the resonance width being
given by the temperature. Likewise, the thermopower shows a characteristic
structure, which is surprisingly well approximated by the so-called Mott
formula. Finally, four-fold splitting of the resonance in a magnetic field
provides a unique signature of the effect.",0609228v1
2006-11-13,Doping dependance of the spin resonance peak in bilayer high-$T_c$ superconductors,"Motivated by a recent experiment on the bilayer
Y$_{1-x}$Ca$_{x}$Ba$_2$Cu$_3$O$_y$ superconductor and based on a bilayer $t-J$
model, we calculate the spin susceptibility at different doping densities in
the even and odd channels in a bilayer system. It is found that the intensity
of the resonance peak in the even channel is much weaker than that in the odd
one, with the resonance position being at a higher frequency. While this
difference decreases as the doping increases, and both the position and
amplitude of the resonance peaks in the two channels are very similar in the
deeply overdoped sample. Moreover, the resonance frequency in the odd channel
is found to be linear with the critical temperature $T_c$, while the resonance
frequency increases as doping decreases in the even channel and tends to
saturate at the underdoped sample. We elaborate the results based on the Fermi
surface topology and the d-wave superconductivity.",0611311v1
2007-02-20,Impurity resonant state in d-wave superconductors: in favor of a Kondo-like response,"We investigate the impurity resonant state induced by non-magnetic impurities
in d-wave cuprate superconductors in two different impurity models: (i) in a
pure potential scattering model within the T-matrix approach and (ii) in a
Bose-Fermi Kondo model within the large-N formalism. We modify the
superconducting host to resemble the nanoscale electronic inhomogeneities seen
in the scanning tunneling microscopy (STM) spectra (i.e., the small- and
large-gap domains) and study how this influences the impurity resonance. In the
pure potential scattering model the resonant state is found to be a rather
robust feature appearing in all host domains. On the other hand, in the
Kondo-like model the impurity resonance can appear in the small-gap regions of
the host and be completely suppressed in the large-gap regions; this is in
agreement with the STM experimental data for Zn-doped BSCCO. Our results imply
that the Kondo spin dynamics of the impurity moment is the origin of the
impurity resonant state in d-wave superconductors, rather than the pure
potential scattering.",0702457v1
2007-03-04,Frequency-Tunable Josephson Junction Resonator for Quantum Computing,"We have fabricated and measured a high-Q Josephson junction resonator with a
tunable resonance frequency. A dc magnetic flux allows the resonance frequency
to be changed by over 10 %. Weak coupling to the environment allows a quality
factor of $\thicksim$7000 when on average less than one photon is stored in the
resonator. At large photon numbers, the nonlinearity of the Josephson junction
creates two stable oscillation states. This resonator can be used as a tool for
investigating the quality of Josephson junctions in qubits below the single
photon limit, and can be used as a microwave qubit readout at high photon
numbers.",0703103v1
2000-10-10,Generalization of a 3-D resonator model for the simulation of spherical enclosures,"A rectangular enclosure has such an even distribution of resonances that it
can be accurately and efficiently modelled using a feedback delay network.
Conversely, a non rectangular shape such as a sphere has a distribution of
resonances that challenges the construction of an efficient model. This work
proposes an extension of the already known feedback delay network structure to
model the resonant properties of a sphere. A specific frequency distribution of
resonances can be approximated, up to a certain frequency, by inserting an
allpass filter of moderate order after each delay line of a feedback delay
network. The structure used for rectangular boxes is therefore augmented with a
set of allpass filters allowing parametric control over the enclosure size and
the boundary properties. This work was motivated by informal listening tests
which have shown that it is possible to identify a basic shape just from the
distribution of its audible resonances.",0010017v2
1999-12-01,Multidimensional Resonance Analysis of $Λ_c^+ \to pK^-π^+$,"We present the results of a five-dimensional resonant amplitude analysis of
the $\Lambda_c^+{\to}pK^{-}\pi^{+}$ system based on $946\pm 38$ reconstructed
decays. These data were produced in 500 GeV/$c$ $\pi^-$-N interactions by
Fermilab experiment E791. We report measurements of the amplitudes for
$\Lambda_c^+$ decay into nonresonant $pK^-\pi^+$ and to $p\bar{K}^{*0}(890)$,
$\Delta^{++}(1232)K^-$, and $\Lambda(1520)\pi^+$ and we comment on other
possible resonant enhancements. This is the first complete amplitude analysis
of the $\Lambda_c^{+}{\to}pK^{-}\pi^{+}$ system. We find that
$(54.8\pm5.5\pm3.5)$% of the decays are nonresonant, $(19.5\pm2.6\pm1.8)$% of
the decays are via the $\bar{K}^{*0}$ resonance, $(18.0\pm2.9\pm2.9)$% of the
decays are via the $\Delta^{++}$ resonance, and $(7.7\pm1.8\pm1.1)$% of the
decays are via the $\Lambda(1520)$ resonance. We find evidence for an
increasingly negative polarization of the $\Lambda_c^+$ baryons as a function
of $p_T^2$, in agreement with a recent model\cite{dha} and with a related
measurement\cite{jez}.",9912003v1
1997-05-13,Strong WW scattering and resonances at LHC,"The low energy dynamics of the general strongly interacting symmetry breaking
sector can be easily described using effective chiral Lagrangians. Indeed, the
enhancement in WW scattering at LHC, that would imply the existence of such an
strong interaction, can be described with just two chiral parameters. These
techniques have been shown to reproduce remarkably well the low-energy
pion-pion scattering data, which follows a similar formalism. In this work we
first review the LHC sensitivity to those two chiral parameters (in the hardest
case of non-resonant low-energy WW scattering). Later it is shown how we can
predict the general resonance spectrum of the strongly interacting symmetry
breaking sector. For that purpose, we use the inverse amplitude method which is
also very successful reproducing the lightest hadronic resonances from data in
the low-energy non resonant region. We thus present an study of the regions in
parameter space where one, two or no resonances may appear.",9705301v1
2000-06-12,Searching for Narrow Graviton Resonances with the ATLAS Detector at the Large Hadron Collider,"A spectrum of massive graviton states is present in several recent
theoretical models that include extra space dimensions. In some such models the
graviton states are well separated in mass, and can be detected as resonances
in collider experiments. The ability of the ATLAS detector at the Large Hadron
Collider to identify such states and measure their properties is considered, in
the case that the resonances are narrow compared to the experimental
resolution. The discovery limits for the detection of the decay mode G->e+e-
are derived. The angular distribution of the lepton pair is used to determine
the spin of the intermediate state. In one specific model, the resonance can be
detected up to a graviton resonance mass of 2080 GeV, while the angular
distribution favours a spin-2 hypothesis over a spin-1 hypothesis at 90%
confidence for resonance masses up to 1720 GeV.",0006114v2
2003-03-13,Hadron Resonance Mass Spectrum and Lattice QCD Thermodynamics,"We confront lattice QCD results on the transition from the hadronic phase to
the quark--gluon plasma with hadron resonance gas and percolation models. We
argue that for T < T_c the equation of state derived from Monte--Carlo
simulations of (2+1) quark--flavor QCD can be well described by a hadron
resonance gas. We examine the quark mass dependence of the hadron spectrum on
the lattice and discuss its description in terms of the MIT bag model. This is
used to formulate a resonance gas model for arbitrary quark masses which can be
compared to lattice calculations. We finally apply this model to analyze the
quark mass dependence of the critical temperature obtained in lattice
calculations. We show that the value of T_c for different quark masses agrees
with lines of constant energy density in a hadron resonance gas. For large
quark masses a corresponding contribution from a glueball resonance gas is
required.",0303108v1
2003-06-27,CP asymmetry in $B^- \to π^+ π^- K^-$ and $B^- \to K^+ K^- K^-$ decays,"The near equality between the measured value for $|V_{ub}|/|V_{cb}|$ and its
unitarity triangle lower bound from $\sin 2\beta$ measurements suggests that
$\alpha \approx 90^{\circ}$ and $\sin\gamma \approx \cos\beta = 0.91$ and a
large direct CP violation in B decays would be possible. In this talk, I would
like to discuss a recent analysis of the non resonant and resonant CP asymmetry
for the decays $B^- \to \pi^+ \pi^- K^-$ and $B^- \to K^+ K^- K^-$ where the CP
asymmetry at the $\chi_{c0}$ resonance comes from the interference of the non
resonant amplitude with the resonant amplitude $B^\pm \to \chi_{c0} K^\pm $ $
\to\pi^+ \pi^- K^\pm $ and $B^\pm \to \chi_{c0} K^\pm$ $ \to K^+ K^- K^\pm$.
Using the the Babar and Belle measurements of the $B^-\to \chi_{c0} K^- $
branching ratios, we predict that partial width asymmetry at the $\chi_{c0}$
resonance could reach 10% for the $B^- \to \pi^+ \pi^- K^-$ decay and 16% for
the $B^- \to K^+ K^- K^-$decay.",0306271v1
2003-07-09,Effective Description of a Gauge Field and a Tower of Massive Vector Resonances,"In this work we review an effective description of the interaction of a gauge
field with a tower of massive vector fields by introducing a non-diagonal mass
matrix in a gauge invariant way. Particular cases of the method with only one
vector resonance have been used by the author elsewhere, nevertheless in this
paper the method is developed in a general way and and we proof its main
features for an arbitrary number of vector resonances. Additionally, we show
how to couple the vector resonances with fermions. We find that the method can
be useful in order to describe the low energy phenomenology of scenarios like
Kaluza-Klein resonances of usual gauge bosons or Technicolor vector resonances
and detailed examples are provided.",0307130v2
2005-07-22,Phenomenology of the Baryon Resonance 70-plet at Large N_c,"We examine the multiplet structure and decay channels of baryon resonances in
the large N_c QCD generalization of the N_c = 3 SU(6) spin-flavor 70. We show
that this ``70'', while a construct of large N_c quark models, actually
consists of five model-independent irreducible spin-flavor multiplets in the
large N_c limit. The preferred decay modes for these resonances fundamentally
depend upon which of the five multiplets to which the resonance belongs. For
example, there exists an SU(3) ``8'' of resonances that is eta-philic and
pi-phobic, and an ``8'' that is the reverse. Moreover, resonances with a strong
SU(3) ``1'' component prefer to decay via a K-bar rather than via a pi.
Remarkably, available data appears to bear out these conclusions.",0507267v1
2006-02-22,Resonance production by neutrinos: The second resonance region,"The article contains new results for spin-3/2 and -1/2 resonances. It
specializes to the second resonance region, which includes the $P_{11}(1440)$,
$D_{13}(1520)$ and $S_{11}(1535)$ resonances. New data on electroproduction
enable us to determine the vector form factors accurately. Estimates for the
axial couplings are obtained from decay rates of the resonances with the help
of the partially conserved axial current (PCAC) hypothesis. We present cross
sections to be compared with the running and future experiments. The article is
self--contained and allows the reader to write simple programs for reproducing
the cross sections and for obtaining additional differential cross sections.",0602210v2
2005-07-14,Spectral asymptotics for periodic fourth order operators,"We consider the operator ${d^4dt^4}+V$ on the real line with a real periodic
potential $V$. The spectrum of this operator is absolutely continuous and
consists of intervals separated by gaps. We define a Lyapunov function which is
analytic on a two sheeted Riemann surface. On each sheet, the Lyapunov function
has the same properties as in the scalar case, but it has branch points, which
we call resonances. We prove the existence of real as well as non-real
resonances for specific potentials. We determine the asymptotics of the
periodic and anti-periodic spectrum and of the resonances at high energy. We
show that there exist two type of gaps: 1) stable gaps, where the endpoints are
periodic and anti-periodic eigenvalues, 2) unstable (resonance) gaps, where the
endpoints are resonances (i.e., real branch points of the Lyapunov function
above the bottom of the spectrum). We also show that the periodic and
anti-periodic spectrum together determine the spectrum of our operator.
Finally, we show that for small potentials $V\ne 0$ the spectrum in the lowest
band has multiplicity 4 and the bottom of the spectrum is a resonance, and not
a periodic (or anti-periodic) eigenvalue.",0507298v1
2002-05-24,Resonance-Assisted Tunneling,"We present evidence that tunneling processes in near-integrable systems are
enhanced due to the manifestation of nonlinear resonances and their respective
island chains in phase space. A semiclassical description of this
""resonance-assisted"" mechanism is given, which is based on a local perturbative
description of the dynamics in the vicinity of the resonances. As underlying
picture, we obtain that the quantum state is coupled, via a succession of
classically forbidden transitions across nonlinear resonances, to high
excitations within the well, from where tunneling occurs with a rather large
rate. The connection between this description and the complex classical
structure of the underlying integrable dynamics is furthermore studied, giving
ground to the general coherence of the description as well as guidelines for
the identification of the dominant tunneling paths. The validity of this
mechanism is demonstrated within the kicked Harper model, where good agreement
between quantum and semiclassical (resonance-assisted) tunneling rates is
found.",0205054v1
2002-12-13,Quantum resonances and decoherence for delta-kicked atoms,"The quantum resonances occurring with delta-kicked atoms when the kicking
period is an integer multiple of the half-Talbot time are analyzed in detail.
Exact results about the momentum distribution at exact resonance are
established, both in the case of totally coherent dynamics and in the case when
decoherence is induced by Spontaneous Emission. A description of the dynamics
when the kicking period is close to, but not exactly at resonance, is derived
by means of a quasi-classical approximation where the detuning from exact
resonance plays the role of the Planck constant. In this way scaling laws
describing the shape of the resonant peaks are obtained. Such analytical
results are supported by extensive numerical simulations, and explain some
recent surprising experimental observations.",0212033v1
2006-04-20,On passage through resonances in volume-preserving systems,"Resonance processes are common phenomena in multiscale (slow-fast) systems.
In the present paper we consider capture into resonance and scattering on
resonance in 3-D volume-preserving slow-fast systems. We propose a general
theory of those processes and apply it to a class of viscous Taylor-Couette
flows between two counter-rotating cylinders. We describe the phenomena during
a single passage through resonance and show that multiple passages lead to the
chaotic advection and mixing. We calculate the width of the mixing domain and
estimate a characteristic time of mixing. We show that the resulting mixing can
be described using a diffusion equation with a diffusion coefficient depending
on the averaged effect of the passages through resonances.",0604047v1
2003-04-02,Photoexcitation of Baryon Resonances - News from the D13(1520),"The so-called second resonance region of the nucleon comprises the states
P11(1440), D13(1520) and S11(1535). During the last few years photoproduction
experiments have largely contributed to a better understanding of these states,
but the strong suppression of the resonance structure in total photoabsorption
experiments from nuclei is still not understood. The D13-resonance dominates
the resonance structure due to its large photon coupling. In this contribution
new results for the excitation and decay modes of the D13 on the free nucleon
and first results for the in-medium behavior of the resonance are summarised.",0304007v1
2003-04-02,In-medium properties of the D13(1520) nucleon resonance,"The in-medium properties of the D13(1520) nucleon resonance were studied via
photoproduction of pi0-mesons from nuclei (C, Ca, Nb, Pb) with the
TAPS-detector at the Mainz MAMI accelerator. The inclusive (single and multiple
pion production) data disagree with model predictions which explain the
disappearance of the second resonance bump in total photoabsorption via a
medium modification of the D13 --> N rho decay. The exclusive single pi0
production data show no broadening of the resonance structure beyond Fermi
smearing. Although due to final state interaction effects pion production tests
the nucleus at densities less than the average nuclear density, both results
together cast doubt on attempts to explain the vanishing of the second
resonance bump for heavy nuclei by a broadening of the D13-resonance in nuclear
matter.",0304010v1
2005-04-25,Measurement of the Polarized Structure Function $σ_{LT^\prime}$ for Pion Electroproduction in the Roper Resonance Region,"The polarized longitudinal-transverse structure function $\sigma_{LT^\prime}$
measures the interference between real and imaginary amplitudes in pion
electroproduction and can be used to probe the coupling between resonant and
non-resonant processes. We report new measurements of $\sigma_{LT^\prime}$ in
the $N(1440){1/2}^+$ (Roper) resonance region at $Q^2=0.40$ and 0.65 GeV$^2$
for both the $\pi^0 p$ and $\pi^+ n$ channels. The experiment was performed at
Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) using
longitudinally polarized electrons at a beam energy of 1.515 GeV. Complete
angular distributions were obtained and are compared to recent phenomenological
models. The $\sigma_{LT^\prime}(\pi^+ n)$ channel shows a large sensitivity to
the Roper resonance multipoles $M_{1-}$ and $S_{1-}$ and provides new
constraints on models of resonance formation.",0504027v2
2003-12-23,"A Genetic Algorithm Analysis of N* Resonances in $p(γ,K^{+})Λ$ Reactions","The problem of extracting information on new and known $N^{*}$ resonances by
fitting isobar models to photonuclear data is addressed. A new fitting
strategy, incorporating a genetic algorithm, is outlined. As an example, the
method is applied to a typical tree-level analysis of published
$p(\gamma,K^{+})\Lambda$ data. It is shown that, within the limitations of this
tree-level analysis, a resonance in addition to the known set is required to
obtain a reasonable fit. An additional $P_{11}$ resonance, with a mass of about
1.9 GeV, gives the best agreement with the published data, but additional
$S_{11}$ or $D_{13}$ resonances cannot be ruled out. Our genetic algorithm
method predicts that photon beam asymmetry and double polarization
$p(\gamma,K^{+})\Lambda$ measurements should provide the most sensitive
information with respect to missing resonances.",0312103v3
2005-02-01,Chiral symmetry and parametrization of scalar resonances,"The linear $\s$-model is used to study the effects of chiral symmetry in
unitarized amplitudes incorporating scalar resonances. When just a single
resonance is present, we show that the iteration of a chiral tree amplitude by
means of regularized two-pion loops preserves the smallness of $\p\p$
interaction at low energies and estimate the importance of pion off-shell
contributions. The inclusion of a second resonance is performed by means of a
chiral extension of the linear $\s$-model lagrangian. The new $\p\p$ ampitude
at tree level complies with low-energy theorems, depends on a mixing angle and
has a zero for a given energy between the resonance masses. The unitarization
of this amplitude by means of two-pion loops preserves both its chiral low
energy behavior and the position of this zero confirming, in a lagrangian
framework, conclusions drawn previously by T\""ornqvist. Finally, we approximate
and generalize our results and give a friendly expression that can be used in
the parametrization of $N$ coupled scalar resonances.",0502001v1
2005-09-19,Helicity amplitudes and electromagnetic decays of hyperon resonances,"We present results for the helicity amplitudes of the lowest-lying hyperon
resonances Y*, computed within the framework of the Bonn constituent-quark
model, which is based on the Bethe-Salpeter approach. The seven parameters
entering the model were fitted to the best known baryon masses. Accordingly,
the results for the helicity amplitudes are genuine predictions. Some hyperon
resonances are seen to couple more strongly to a virtual photon with finite Q^2
than to a real photon. Other Y*'s, such as the S_{01}(1670) Lambda resonance or
the S_{11}(1620) Sigma resonance, couple very strongly to real photons. We
present a qualitative argument for predicting the behaviour of the helicity
asymmetries of baryon resonances at high Q^2.",0509047v1
2007-01-01,Contribution of spin 1/2 and 3/2 resonances to two-photon exchange effects in elastic electron-proton scattering,"We calculate contributions of hadron resonances to two-photon exchange
effects in electron-proton scattering. In addition to the nucleon and P33
resonance, the following heavier resonances are included as intermediate states
in the two-photon exchange diagrams: D13, D33, P11, S11 and S31. We show that
the corrections due to the heavier resonances are smaller that the dominant
nucleon and P33 contributions. We also find that there is a partial
cancellation between the contributions from the spin 1/2 and spin 3/2
resonances, which results in a further suppression of their aggregate
two-photon exchange effect.",0701003v2
1997-12-17,Properties of resonant activation phenomena,"The phenomenon of resonant activation of a Brownian particle over a
fluctuating barrier is revisited. We discuss the important distinctions between
barriers that can fluctuate among ""up"" and ""down"" configurations, and barriers
that are always ""up"" but that can fluctuate among different heights. A
resonance as a function of the barrier fluctuation rate is found in both cases,
but the nature and physical description of these resonances is quite distinct.
The nature of the resonances, the physical basis for the resonant behavior, and
the importance of boundary conditions are discussed in some detail. We obtain
analytic expressions for the escape time over the barrier that explicitly
capture the minima as a function of the barrier fluctuation rate, and show that
our analytic results are in excellent agreement with numerical results.",9712036v1
1999-05-13,Study of Multiple-Beam RFQ,"There are applications, which require MeV-range multiple-beams consisting of
a large number of identical highly packed beamlets. The multiple-beam RFQ
(MB-RFQ) arranged as a matrix array of longitudinal rod-electrodes is
appropriate candidate. A configuration of MB-RFQ resonator should ensure
identical quadrupole fields in every accelerating channel. The MB-RFQ
resonators based on TEM transmission lines are studied. The resonators are
designed by a periodical multiplication of a 4-rod unit cell in transverse
direction. To understand fields of resonator the normal mode technique is
applied. Novel configurations of MB-RFQ resonators based on these normal modes
are generated. The RF properties of resonators are verified with computer
simulations done with MAFIA code. Beam dynamics study for the initial 400-keV
MB-RFQ has been performed using PARMTEQ code. The MB-RFQ parameters and the
results of beam dynamics simulations are presented. The calculated beam
transmission is 33% at injection of 50-keV, 20mA deuteron beam.",9905033v1
2001-03-28,"Motion, Universality of Velocities, Masses in Wave Universe. Transitive States (Resonances) - Mass Spectrum","Wave Universe Concept (WU Concept) opens new wide possibilities for the
effective description of Elementar Objects of Matter (EOM) hierarchy, in
particular, of particles, resonances mass spectrum of subatomic (and HEP)
physics.
  The special attention to analysis and precise description of wide and
important set - Transitive states (resonances) of EOM is payed.
  Its are obtained sufficiently precise representations for mass values, cross
relations between masses of wide set objects of particle physics - metastable
resonances - (fast moving) Transitive states - in terms of representations of
Wave Universe Concept (WU Concept).
  Wide set of observed in experiments effects and connected with its resonances
(including - Darmstadt effect, ABC effect,etc.) may be effectively interpreted
in WU Concept and described with use of mass formula - as manifestation of
rapidly moving, physically distinguished transitive states (resonances)",0103089v1
2002-03-05,Study On Planar Whispering Gallery Dielectric Resonators. II. A Multiple-Band Device,"The basic theory underlying the realization of simple multiple-band
non-homogeneous dielectric resonators, whose spectral response is the overlap
of single-resonator frequency bands, is developed exploiting a general approach
discussed in the previous companion paper. The limit frequencies of the
proposed devices, given only by the dielectric properties of the involved
materials, can differ in principle by several decades. Experimental
confirmations have been obtained on a composite structure built up with teflon
and polyethylene; as predicted by the theory, the overall band includes
frequencies which range about from 20 GHz to more than 400 GHz, when high
frequency resonances are selectively excited. The localization of the higher
frequency radiation between the positive steps of the dielectric constant,
which is the basic properties of these non-homogeneous resonators, has been
experimentally verified by mapping the electromagnetic field intensity.
Possible applications of multiple-band Whispering Gallery dielectric resonators
are finally outlined.",0203010v1
2004-05-05,Unified algebraic treatment of resonance,"Energy resonance in scattering is usually investigated either directly in the
complex energy plane (E-plane) or indirectly in the complex angular momentum
plane (L-plane). Another formulation complementing these two approaches was
introduced recently. It is an indirect algebraic method that studies resonances
in a complex charge plane (Z-plane). This latter approach will be generalized
to provide a unified algebraic treatment of resonances in the complex E-, L-,
and Z-planes. The complex scaling (rotation) method will be used in the
development of this approach. The resolvent operators (Green's functions) are
formally defined in these three spaces. Bound states spectrum and resonance
energies in the E-plane are mapped onto a discrete set of poles of the
respective resolvent operator on the real line of the L- and Z-planes. These
poles move along trajectories as the energy is varied. A finite square
integrable basis is used in the numerical implementation of this approach.
Stability of poles and trajectories against variation in all computational
parameters is demonstrated. Resonance energies for a given potential are
calculated and compared with those obtained by other studies.",0405017v1
2004-06-16,Laser-induced splittings in the nuclear magnetic resonance spectra of the rare gases,"Circularly polarized laser field causes a shift in the nuclear magnetic
resonance (NMR) spectra of all substances. The shift is proportional to the
intensity of the laser beam and yields oppositely signed values for left- and
right-circularly polarized light, CPL -/+, respectively. Rapid switching -- in
the NMR time scale -- between CPL+ and CPL- gives rise to a splitting of the
NMR resonance lines. We present uncorrelated and correlated quadratic response
calculations of the splitting per unit of beam intensity in the NMR spectra of
$^{21}$Ne, $^{83}$Kr, and $^{129}$Xe. We study both the regions far away from
and near to optical resonance and predict off-resonance shifts of the order
0.01, 0.1, and $1\times 10^{-6}$ Hz for $^{21}$Ne, $^{83}$Kr, and $^{129}$Xe,
respectively, for a beam intensity of 10 W/cm$^2$. Enhancement by several
orders of magnitude is predicted as the beam frequency approaches resonance.
Only then can the effect on guest $^{129}$Xe atoms be potentially useful as a
probe of the properties of the host material.",0406073v1
2005-02-01,Axially open nonradiative structures: an example of single-mode resonator based on the sample holder,"The concept of nonradiative dielectric resonator is generalized in order to
include axially open configurations having rotational invariance. The resulting
additional nonradiative conditions are established for the different resonance
modes on the basis of their azimuthal modal index. An approximate chart of the
allowed dielectric and geometrical parameters for the TE011 mode is given. A
practical realization of the proposed device based on commercial fused quartz
tubes is demonstrated at millimeter wavelengths, together with simple
excitation and tuning mechanisms. The observed resonances are characterized in
their basic parameters, as well as in the field distribution by means of a
finite element method. The predictions of the theoretical analysis are well
confirmed, both in the general behaviour and in the expected quality factors.
The resulting device, in which the sample holder acts itself as single-mode
resonating element, combines an extreme ease of realization with
state-of-the-art performances. The general benefits of the proposed open
single-mode resonators are finally discussed.",0502004v1
2005-03-09,Fast growing double tearing modes in a tokamak plasma,"Configurations with nearby multiple resonant surfaces have broad spectra of
linearly unstable coupled tearing modes with dominant high poloidal mode
numbers m. This was recently shown for the case of multiple q = 1 resonances
[Bierwage et al., Phys. Rev. Lett. 94 (6), 65001 (2005)]. In the present work,
similar behavior is found for double tearing modes (DTM) on resonant surfaces
with q >= 1. A detailed analysis of linear instability characteristics of DTMs
with various mode numbers m is performed using numerical simulations. The mode
structures and dispersion relations for linearly unstable modes are calculated.
Comparisons between low- and higher-m modes are carried out, and the roles of
the inter-resonance distance and of the magnetic Reynolds number S_Hp are
investigated. High-m modes are found to be destabilized when the distance
between the resonant surfaces is small. They dominate over low-m modes in a
wide range of S_Hp, including regimes relevant for tokamak operation. These
results may be readily applied to configurations with more than two resonant
surfaces.",0503068v2
2005-04-22,High frequency single-mode resonators for EPR spectroscopy enabling rotations of the sample about two orthogonal axes,"A novel single-mode resonant structure which enables the rotation of the
sample about two orthogonal axes is investigated in view of electron
paramagnetic resonance applications. The proposed solution is based on
cylindrical nonradiative resonators laterally loaded by the sample holder. The
resulting structure can still operate in nonradiative regime, although no
longer rotationally invariant. These theoretical predictions, based on symmetry
considerations, are confirmed by means of a finite element numerical modelling.
Theoretical and computational results are then substantiated by experimental
investigations at millimeter wavelengths. As a result, a single-mode resonator
which enables all the relevant rotations of the sample is demonstrated at
millimeter wavelengths for the first time. In this resonator the intensity of
the microwave field on the sample and its orientation with respect to the
static magnetic field can be kept constant during the rotations. Therefore, a
complete characterization of anisotropic systems is possible at the highest
sensitivity, without the need of split-coil magnets. Possible applications at
very high frequencies are discussed.",0504159v1
2006-05-18,"All-optical switching, bistability, and slow-light transmission in photonic crystal waveguide-resonator structures","We analyze the resonant linear and nonlinear transmission through a photonic
crystal waveguide side-coupled to a Kerr-nonlinear photonic crystal resonator.
Firstly, we extend the standard coupled-mode theory analysis to photonic
crystal structures and obtain explicit analytical expressions for the
bistability thresholds and transmission coefficients which provide the basis
for a detailed understanding of the possibilities associated with these
structures. Next, we discuss limitations of standard coupled-mode theory and
present an alternative analytical approach based on the effective discrete
equations derived using a Green's function method. We find that the discrete
nature of the photonic crystal waveguides allows a novel, geometry-driven
enhancement of nonlinear effects by shifting the resonator location relative to
the waveguide, thus providing an additional control of resonant waveguide
transmission and Fano resonances. We further demonstrate that this enhancement
may result in the lowering of the bistability threshold and switching power of
nonlinear devices by several orders of magnitude. Finally, we show that
employing such enhancements is of paramount importance for the design of
all-optical devices based on slow-light photonic crystal waveguides.",0605156v1
2006-09-01,Influence of Morphology on the Optical Properties of Metal Nanoparticles,"The influence of morphology on the optical properties of silver nanoparticles
is studied. A general relationship between the surface plasmon resonances and
the morphology of each nanoparticle is established. The optical response is
investigated for cubes and decahedrons with different truncations. We found
that polyhedral nanoparticles composed with less faces show more surface
plasmon resonances than spherical-like ones. It is also observed that the
vertices of the nanoparticles play an important role in the optical response,
because the sharpener they become, the greater the number of resonances. For
all the nanoparticles, a main resonance with a dipolar character was identified
as well as other secondary resonances of less intensity. It is also found that
as the nanoparticle becomes more symmetric, the main resonance is always blue
shifted.",0609015v1
2006-10-24,Feshbach resonances in ultracold atomic and molecular collisions: threshold behaviour and suppression of poles in scattering lengths,"In the absence of inelastic scattering, Feshbach resonances produce poles in
scattering lengths and very large peaks in elastic cross sections. However,
inelastic scattering removes the poles. Whenever the resonant state is coupled
comparably to the elastic and inelastic channels, the scattering length
exhibits only a small oscillation and peaks in cross sections are dramatically
suppressed. A resonant scattering length is defined to characterize the
amplitude of the oscillation, and is shown to be small for many collisions of
ultracold molecules. The results suggest that cross sections for ultracold
molecular inelastic collisions are much less sensitive to details of the
potential than has been believed.",0610210v4
2000-11-09,Dynamical analysis of the buildup process near resonance,"The time evolution of the buildup process inside a double-barrier system for
off-resonance incidence energies is studied by considering the analytic
solution of the time dependent Schr\""{o}dinger equation with cutoff plane wave
initial conditions. We show that the buildup process exhibits invariances under
arbitrary changes on the system parameters, which can be successfully described
by a simple and easy-to-use one-level formula. We find that the buildup of the
off-resonant probability density is characterized by an oscillatory pattern
modulated by the resonant case which governs the duration of the transient
regime. This is evidence that off-resonant and resonant tunneling are two
correlated processes, whose transient regime is characterized by the same
transient time constant of two lifetimes.",0011032v1
2004-12-30,Nanomagnetic Planar Magnetic Resonance Microscopy Lens,"The achievement of three-dimensional atomic resolution magnetic resonance
microscopy remains one of the main challenges in the visualization of
biological molecules. The prospects for single spin microscopy have come
tantalizingly close due to the recent developments in sensitive
instrumentation. Despite the single spin detection capability in systems of
spatially well-isolated spins, the challenge that remains is the creation of
conditions in space where only a single spin is resonant and detected in the
presence of other spins in its natural dense spin environment. We present a
nanomagnetic planar design where a localized Angstrom-scale point in
three-dimensional space is created above the nanostructure with a non-zero
minimum of the magnetic field magnitude. The design thereby represents a
magnetic resonance microscopy lens where potentially only a single spin located
in the focus spot of the structure is resonant. Despite the presence of other
spins in the Angstrom-scale vicinity of the resonant spin, the high gradient
magnetic field of the lens renders those spins inactive in the detection
process.",0412217v1
2006-05-19,High-sensitivity optical monitoring of a micro-mechanical resonator with a quantum-limited optomechanical sensor,"We experimentally demonstrate the high-sensitivity optical monitoring of a
micro-mechanical resonator and its cooling by active control. Coating a
low-loss mirror upon the resonator, we have built an optomechanical sensor
based on a very high-finesse cavity (30000). We have measured the thermal noise
of the resonator with a quantum-limited sensitivity at the 10^-19 m/rootHz
level, and cooled the resonator down to 5K by a cold-damping technique.
Applications of our setup range from quantum optics experiments to the
experimental demonstration of the quantum ground state of a macroscopic
mechanical resonator.",0605174v1
2007-01-29,Two-Mode Squeezed States and Entangled States of Two Mechanical Resonators,"We study a device consisting of a dc-SQUID with two sections of its loop
acting as two mechanical resonators. An analog of the parametric
down-conversion process in quantum optics can be realized with this device. We
show that a two-mode squeezed state can be generated for two overdamped
mechanical resonators, where the damping constants of the two mechanical
resonators are larger than the coupling strengths between the dc-SQUID and the
two mechanical resonators. Thus we show that entangled states of these two
mechanical resonators can be generated.",0701209v3
2007-04-16,Strange dibaryon resonance in the anti-KNN--piYN system,"Three-body resonances in the \bar{K}NN system have been studied within a
framework of the \bar{K}NN-\pi YN coupled hannel Faddeev equation. By solving
the three-body equation the energy dependence of the resonant \bar{K}N
amplitude is fully taken into account. The S-matrix pole has been investigated
from the eigenvalue of the kernel with the analytic continuation of the
scattering amplitude on the unphysical Riemann sheet. The \barKN interaction is
constructed from the leading order term of the chiral Lagrangian using
relativistic kinematics. The \Lambda(1405) resonance is dynamically generated
in this model, where the \bar{K}N interaction parameters are fitted to the data
of scattering length. As a result we find a three-body resonance of the strange
dibaryon system with binding energy, B~79 MeV, and width, \Gamma~74 MeV. The
energy of the three-body resonance is found to be sensitive to the model of the
I=0 \barKN interaction.",0704.1978v2
2007-08-07,Resonance scattering in the X-ray emission line profiles of Zeta Puppis,"We present XMM-Newton Reflection Grating Spectrometer observations of pairs
of X-ray emission line profiles from the O star Zeta Pup that originate from
the same He-like ion. The two profiles in each pair have different shapes and
cannot both be consistently fit by models assuming the same wind parameters. We
show that the differences in profile shape can be accounted for in a model
including the effects of resonance scattering, which affects the resonance line
in the pair but not the intercombination line. This implies that resonance
scattering is also important in single resonance lines, where its effect is
difficult to distinguish from a low effective continuum optical depth in the
wind. Thus, resonance scattering may help reconcile X-ray line profile shapes
with literature mass-loss rates.",0708.1011v1
2007-08-09,Theoretical study of dark resonances in micro-metric thin cells,"We investigate theoretically dark resonance spectroscopy for a dilute atomic
vapor confined in a thin (micro-metric) cell. We identify the physical
parameters characterizing the spectra and study their influence. We focus on a
Hanle-type situation, with an optical irradiation under normal incidence and
resonant with the atomic transition. The dark resonance spectrum is predicted
to combine broad wings with a sharp maximum at line-center, that can be singled
out when detecting a derivative of the dark resonance spectrum. This narrow
signal derivative, shown to broaden only sub-linearly with the cell length, is
a signature of the contribution of atoms slow enough to fly between the cell
windows in a time as long as the characteristic ground state optical pumping
time. We suggest that this dark resonance spectroscopy in micro-metric thin
cells could be a suitable tool for probing the effective velocity distribution
in the thin cell arising from the atomic desorption processes, and notably to
identify the limiting factors affecting desorption under a grazing incidence.",0708.1307v1
2007-11-02,Spin-torque driven ferromagnetic resonance of Co/Ni synthetic layers in spin valves,"Spin-torque driven ferromagnetic resonance (ST-FMR) is used to study thin
Co/Ni synthetic layers with perpendicular anisotropy confined in spin-valve
based nanojunctions. Field swept ST-FMR measurements were conducted with a
magnetic field applied perpendicular to the layer surface. The resonance lines
were measured under low amplitude rf excitation, from 1 to 20 GHz. These
results are compared with those obtained using conventional rf field driven FMR
on extended films with the same Co/Ni layer structure. The layers confined in
spin valves have a lower resonance field, a narrower resonance linewidth and
approximately the same linewidth vs frequency slope, implying the same damping
parameter. The critical current for magnetic excitations is determined from
measurements of the resonance linewidth vs dc current and is in accord with the
one determined from I-V measurements.",0711.0405v2
2007-11-29,Generalized Galitskii approach for the vertex function of a Fermi gas with resonant interaction,"We present a generalized Galitskii approach for the Bethe-Salpeter equation
for the two-particle vertex function of a Fermi system with resonant
interaction by accounting for the resonant state in the scattering potential
and utilizing the universal form of the resonant scattering amplitude. The
procedure can be carried out both for the normal as well as for the condensate
state. In both cases, the vertex function in the vicinity of the resonance is
shown to formally coincide with that obtained for a weakly attractive Fermi
gas. Thus we justify the popular calculational framework in which results for
the weakly attractive Fermi gas are formally extrapolated into the domain of
strong coupling, and further to the repulsive side of the resonance, where
molecular states are formed.",0711.4758v1
2007-12-05,All-optical production of 7Li Bose-Einstein condensation using Feshbach resonances,"We show an all-optical method of making 7Li condensate using tunability of
the scattering length in the proximity of a Feshbach resonance. We report the
observation of two new Feshbach resonances on |F = 1;mF = 0> state. The narrow
(broad) resonance of 7 G (34 G) width is detected at 831 +- 4 G (884 +4 -13 G).
Position of the scattering length zero crossing between the resonances is found
at 836 +- 4 G. The broad resonance is shown to be favorable for run away
evaporation which we perform in a crossed-beam optical dipole trap. Starting
directly form the phase space density of a magneto-optical trap we observe a
Bose-Einstein condensation threshold in less than 3 s of forced evaporation.",0712.0717v1
2007-12-06,Room temperature observation of electron resonant tunneling through InAs/AlAs quantum dots,"Molecular beam epitaxy is employed to manufacture self-assembled InAs/AlAs
quantum-dot resonant tunneling diodes. Resonant tunneling current is
superimposed on the thermal current, and they make up the total electron
transport in devices. Steps in current-voltage characteristics and peaks in
capacitance-voltage characteristics are explained as electron resonant
tunneling via quantum dots at 77K or 300K, and this is the first time that
resonant tunneling is observed at room temperature in III-V quantum-dot
materials. Hysteresis loops in the curves are attributed to hot electron
injection/emission process of quantum dots, which indicates the concomitant
charging/discharging effect.",0712.0972v1
2007-12-27,Nucleon and Delta resonances in K Sigma(1385) photoproduction from nucleons,"The reaction mechanisms for $K\Sigma(1385)$ photoproduction from the reaction
$\gamma p \to K^+\Sigma^{0}(1385)$ in the resonance energy region are
investigated in a hadronic model. Both contributions from $N$ and $\Delta$
resonances of masses around 2 GeV as given in the Review of Particle Data Group
and by the quark model predictions are included. The Lagrangians for describing
the decays of these resonances into $K\Sigma(1385)$ are constructed with the
coupling constants determined from the decay amplitudes predicted by a quark
model. Comparing the resulting total cross section for the reaction $\gamma p
\to K^+\Sigma^{0}(1385)$ with the preliminary data from the Thomas Jefferson
National Accelerator Facility, we find that the most important contributions
are from the two-star rated resonances $\Delta(2000) F_{35}$, $\Delta(1940)
D_{33}$, and $N(2080) D_{13}$, as well as the missing resonance
$N\frac32^-(2095)$ predicted in the quark model. Predictions on the
differential cross section and photon asymmetry in this reaction are also
given.",0712.4285v2
2008-02-21,Liquid Density Sensing Using Resonant Flexural Plate Wave Device with Sol-Gel PZT Thin Films,"This paper presents the design, fabrication and preliminary experimental
results of a flexure plate wave (FPW) resonator using sol-gel derived lead
zirconate titanates (PZT) thin films. The resonator adopts a two-port structure
with reflecting grates on the composite membrane of PZT and SiNx. The design of
the reflecting grate is derived from a SAW resonator model using COM theory to
produce a sharp resonant peak. The comparison between the mass and the
viscosity effects from the theoretical expression illustrates the applications
and the constraints of the proposed device in liquid sensing. Multiple coatings
of sol-gel derived PZT films are adopted because of the cost advantage and the
high electromechanical coupling effect over other piezoelectric films. The
fabrication issues of the proposed material structure are addressed.
Theoretical estimations of the mass and the viscosity effects are compared with
the experimental results. The resonant frequency has a good linear correlation
with the density of low viscosity liquids, which demonstrate the feasibility of
the proposed device.",0802.3043v1
2008-02-21,A High-Q Microwave MEMS Resonator,"A High-Q microwave (K band) MEMS resonator is presented, which empolys
substrate integrated waveguide (SIW) and micromachined via-hole arrays by ICP
process. Nonradiation dielectric waveguide (NRD) is formed by metal filled
via-hole arrays and grounded planes. The three dimensional (3D) high
resistivity silicon substrate filled cavity resonator is fed by current probes
using CPW line. This monolithic resonator results in low cost, high performance
and easy integration with planar cicuits. The measured quality factor is beyond
180 and the resonance frequency is 21GHz.It shows a good agreement with the
simulation results. The chip size is only 4.7mm x 4.6mm x 0.5mm. Finally, as an
example of applications, a filter using two SIW resonators is designed.",0802.3081v1
2008-04-29,The $N^*(1710)$ as a resonance in the $ππN$ system,"We study the $\pi \pi N$ system by solving the Faddeev equations, for which
the input two-body $t$-matrices are obtained by solving the Bethe-Salpeter
equation in the coupled channel formalism. The potentials for the $\pi \pi$,
$\pi N$ sub-systems and their coupled channels are obtained from chiral
Lagrangians, which have been earlier used to study resonances in these systems
successfully. In this work, we find a resonance in the $\pi\pi N$ system with a
mass of $1704 - i 375/2$ MeV and with quantum numbers $I=1/2$, $J^\pi =1/2^+$.
We identify this state with the $N^*(1710)$. This peak is found where the
energies of the $\pi \pi$ sub-system fall in the region of the $\sigma$
resonance. We do not find evidence for the Roper resonance in our study
indicating a more complex structure for this resonance, nor for any state with
total isospin $I=3/2$ or $5/2$.",0804.4670v1
2008-05-01,Velocity-selective sublevel resonance of atoms with an array of current-carrying wires,"Resonance transitions between the Zeeman sublevels of optically-polarized Rb
atoms traveling through a spatially periodic magnetic field are investigated in
a radio-frequency (rf) range of sub-MHz. The atomic motion induces the
resonance when the Zeeman splitting is equal to the frequency at which the
moving atoms feel the magnetic field oscillating. Additional temporal
oscillation of the spatially periodic field splits a motion-induced resonance
peak into two by an amount of this oscillation frequency. At higher oscillation
frequencies, it is more suitable to consider that the resonance is mainly
driven by the temporal field oscillation, with its velocity-dependence or
Doppler shift caused by the atomic motion through the periodic field. A
theoretical description of motion-induced resonance is also given, with
emphasis on the translational energy change associated with the internal
transition.",0805.0088v2
2008-05-26,Split ring resonator-coupled enhanced transmission through a single subwavelength aperture,"We report the enhanced transmission of electromagnetic waves through a single
subwavelength aperture by making use of the resonance behavior of a split ring
resonator (SRR) at microwave frequencies. By placing a single SRR at the
near-field of the aperture, strongly localized electromagnetic fields are
effectively coupled to the aperture with a radius that is twenty times smaller
than the resonance wavelength. We obtained 740-fold transmission enhancement by
exciting the electric resonance of SRR. A different coupling mechanism, through
the magnetic resonance of SRR, is also verified to yield enhanced transmission.
Good agreement is obtained between the microwave measurements and numerical
simulations.",0805.3907v1
2008-06-17,Resonance enhancement of magnetic Faraday rotation,"Magnetic Faraday rotation is widely used in optics. In natural transparent
materials, this effect is very weak. One way to enhance it is to incorporate
the magnetic material into a periodic layered structure displaying a high-Q
resonance. One problem with such magneto-optical resonators is that a
significant enhancement of Faraday rotation is inevitably accompanied by strong
ellipticity of the transmitted light. More importantly, along with the Faraday
rotation, the resonator also enhances linear birefringence and absorption
associated with the magnetic material. The latter side effect can put severe
limitations on the device performance. From this perspective, we carry out a
comparative analysis of optical microcavity and a slow wave resonator. We show
that slow wave resonator has a fundamental advantage when it comes to Faraday
rotation enhancement in lossy magnetic materials.",0806.2884v1
2008-06-24,Fractional resonances in the atom-optical delta-kicked accelerator,"We consider resonant dynamics in a dilute atomic gas falling under gravity
through a periodically pulsed standing-wave laser field. Our numerical
calculations are based on a Monte Carlo method for an incoherent mixture of
noninteracting plane waves, and show that quantum resonances are highly
sensitive to the relative acceleration between the atomic gas and the pulsed
optical standing wave. For particular values of the atomic acceleration, we
observe fractional resonances. We investigate the effect of the initial atomic
momentum width on the fractional resonances, and quantify the sensitivity of
fractional resonances to thermal effects.",0806.3894v2
2008-08-06,Electron spin resonance in Kondo systems,"We calculate the dynamical spin response of Kondo impurity and Kondo lattice
systems within a semiphenomenological Fermi liquid description, at low
temperatures $T<T_K$, the Kondo temperature, and low magnetic fields $B \ll k_B
T_K/g\mu_B$. Fermi liquid parameters are determined by comparison (i) with
microscopic theory (numerical renormalization group) for the impurity model and
(ii) with experiment for the lattice model. We find in the impurity case that
the true impurity spin resonance has a width of the order of $T_K$ and
disappears altogether if the $g$-factors of impurity spin and conduction
electron spin are equal. However, there is an impurity-induced resonance
contribution at the conduction electron resonance. The latter is broadened by
spin lattice relaxation and is usually unobservable. In contrast, for the
Anderson lattice in the Kondo regime we find a \textit{sharp} ESR resonance
line only slightly shifted from the local resonance and broadened by spin
lattice relaxation, the latter significantly reduced by both the effects of
heavy fermion physics and ferromagnetic fluctuations. We conjecture that our
findings explain the sharp ESR-lines recently observed in several heavy fermion
compounds.",0808.0892v2
2008-08-25,Role of the N*(1440) resonance in the pp->pnpi+ reaction,"New measurement by CELSIUS-WASA Collaboration on the pp->pn pi+ reaction
reveals clear evidence for the presence of the Roper resonance N*(1440) which
has been ignored in previous theoretical calculations. In this article, based
on an effective Lagrangian approach and available knowledge on the Roper
resonance, we investigate the role of the Roper resonance for the pp->pn pi+
reaction. It is found that the contribution from the Roper resonance N*(1440)
becomes significant for kinetic energy above 1.1 GeV, consistent with the new
experimental observation. The t-channel sigma-meson exchange is dominant for
the production of the Roper resonance.",0808.3257v3
2008-09-22,The $γγ$ decay of the $f_0(1370)$ and $f_2(1270)$ resonances in the hidden gauge formalism,"Using recent results obtained within the hidden gauge formalism for vector
mesons, in which the $f_0(1370)$ and $f_2(1270)$ resonances are dynamically
generated resonances from the $\rho \rho$ interaction, we evaluate the
radiative decay of these resonances into $\gamma \gamma$. We obtain results for
the width in good agreement with the experimental data for the $f_2(1270)$
state and a width about a factor five smaller for the $f_0(1370)$ resonance,
which would agree with preliminary results from the Belle collaboration,
hinting at an order of magnitude smaller width for this resonance than for the
$f_2(1270)$.",0809.3717v3
2008-09-28,Feshbach projection-operator formalism to resonance scattering on Bargmann-type potentials,"The projection-operator formalism of Feshbach is applied to resonance
scattering in a single-channel case. The method is based on the division of the
full function space into two segments, internal (localized) and external
(infinitely extended). The spectroscopic information on the resonances is
obtained from the non-Hermitian effective Hamilton operator $H_{\rm eff}$
appearing in the internal part due to the coupling to the external part. As
well known, additional so-called cut-off poles of the $S$-matrix appear,
generally, due to the truncation of the potential. We study the question of
spurious $S$ matrix poles in the framework of the Feshbach formalism. The
numerical analysis is performed for exactly solvable potentials with a finite
number of resonance states. These potentials represent a generalization of
Bargmann-type potentials to accept resonance states. Our calculations
demonstrate that the poles of the $S$ matrix obtained by using the Feshbach
projection-operator formalism coincide with both the complex energies of the
physical resonances and the cut-off poles of the $S$-matrix.",0809.4848v3
2008-10-20,A resonance theory for open quantum systems with time-dependent dynamics,"We develop a resonance theory to describe the evolution of open systems with
time-dependent dynamics. Our approach is based on piecewise constant
Hamiltonians: we represent the evolution on each constant bit using a recently
developed dynamical resonance theory, and we piece them together to obtain the
total evolution. The initial state corresponding to one time-interval with
constant Hamiltonian is the final state of the system corresponding to the
interval before. This results in a non-markovian dynamics. We find a
representation of the dynamics in terms of resonance energies and resonance
states associated to the Hamiltonians, valid for all times $t\geq 0$ and for
small (but fixed) interaction strengths. The representation has the form of a
path integral over resonances. We present applications to a spin-fermion
system, where the energy levels of the spin may undergo rather arbitrary
crossings in the course of time. In particular, we find the probability for
transition between ground- and excited state at all times.",0810.3540v1
2008-10-27,Investigation of resonant and transient phenomena in Josephson junction flux qubits,"We present an analytical and computational study of resonances and transient
responses in a classical Josephson junction system. A theoretical basis for
resonances in a superconducting loop with three junctions is presented,
outlining both the direct relationship between the dynamics of single- and
multi-junction systems, and the direct relationships between observations of
the classical counterparts to Rabi oscillations, Ramsey fringes, and spin echo
oscillations in this class of systems. We show simulations data along with
analytical analyses of the classical model, and the results are related to
previously reported experiments conducted on three junction loops. We further
investigate the effect of off-resonant microwave perturbations to, e.g., the
Rabi-type response of the Josephson system, and we relate this response back to
the nonlinear and multi-valued resonance behavior previously reported for a
single Josephson junction. The close relationships between single and
multi-junction behavior demonstrates the underlying dynamical mechanism for a
whole class of classical counterparts to expected quantum mechanical
observations in a variety of systems; namely the resonant and transient
behavior of a particle in an anharmonic potential well with subsequent escape.",0810.4731v2
2008-11-05,Resonant charge and spin transport in a t-stub coupled to a superconductor,"We study transport through a single channel t-stub geometry strongly coupled
to a superconducting reservoir. In contrast to the standard stub geometry which
has both transmission resonances and anti-resonances in the coherent limit, we
find that due to the proximity effect, this geometry shows neither a T=1
resonance (T is the transmission probability for electrons incident on the
t-stub) nor a T=0 anti-resonance as we vary the energy of the incident
electron. Instead, we find that there is only one resonant value at T=1/4,
where charge transport vanishes while the spin transport is perfect.",0811.0660v4
2008-11-08,"The Observation of Exotic Resonances for $Λγ $,$Λπ^{\pm}$,$Λπ^+π^-$, $Λp$, $Λpp$ and $p γ$ Spectra in p + a Collision at 10 Gev/c","Strange multi-baryonic clusters are an exiting possibility to explore the
properties of cold dense baryonic matter. Recent results on searches for exotic
narrow resonances with $\Lambda$ hyperon subsystems are reviewed. The
observation of $\Sigma^0$, $\Sigma^{*+}$(1385) and $K^{*\pm}$(892) well known
resonances from PDG are a good tests of this method. The mean value of mass for
$\Sigma^{*-}(1385)$ resonance is shifted till mass of 1370 MeV/$c^2$ and width
is two times larger than same value from PDG. Such of behavior for width and
mass of $\Sigma^{*-}(1385)$ resonance interpreted as extensive contribution
from stopping $\Xi^-\to\Lambda\pi^-$ and medium effect with mass of
$\Sigma^{*-}(1385)$ resonance.In ($\Lambda\pi^+ \pi^-$) spectrum there are
observed enhancement signals from $\Lambda ^*(1600)$, $\Lambda ^*(1750)$ and
$\Lambda ^*(1850)$ resonances. A number of significant signals were found in
the effective mass spectra of: 1)$\Lambda \gamma$,$p \gamma$ $\Lambda
\pi^{\pm}$,$\Lambda \pi \pi$, $\Lambda p$ and $\Lambda p p$ subsystems.",0811.1273v2
2008-11-26,A Feshbach resonance in d-wave collisions,"We analyse a narrow Feshbach resonance with ultra-cold chromium atoms
colliding in d-wave. The resonance is made possible by dipole-dipole
interactions, which couple an incoming $l=2$ collision channel with a bound
molecular state with $l=0$. We find that three-body losses associated to this
resonance increase with temperature, and that the loss feature width as a
function of magnetic field also increases linearly with temperature. The
analysis of our experimental data shows that the Feshbach coupling is small
compared both to the temperature and to the density limited lifetime of the
resonant bound molecular state. One consequence is that the three body losse
rate is proportionnal to the square of the number of atoms, and that we can
directly relate the amplitude of the losses to the Feshbach coupling parameter.
We compare our measurement to a calculation of the coupling between the
collisionnal channel and the molecular bound state by dipole-dipole
interactions, and find a good agreement, with no adjustable parameter. An
analysis of the loss lineshape is also performed, which enables to precisely
measure the position of the resonance.",0811.4282v1
2008-12-06,Feshbach Resonances in Ultracold Gases,"Feshbach resonances are the essential tool to control the interaction between
atoms in ultracold quantum gases. They have found numerous experimental
applications, opening up the way to important breakthroughs. This Review
broadly covers the phenomenon of Feshbach resonances in ultracold gases and
their main applications. This includes the theoretical background and models
for the description of Feshbach resonances, the experimental methods to find
and characterize the resonances, a discussion of the main properties of
resonances in various atomic species and mixed atomic species systems, and an
overview of key experiments with atomic Bose-Einstein condensates, degenerate
Fermi gases, and ultracold molecules.",0812.1496v2
2009-02-03,Dynamics of planets in retrograde mean motion resonance,"In a previous paper (Gayon & Bois 2008a), we have shown the general
efficiency of retrograde resonances for stabilizing compact planetary systems.
Such retrograde resonances can be found when two-planets of a three-body
planetary system are both in mean motion resonance and revolve in opposite
directions. For a particular two-planet system, we have also obtained a new
orbital fit involving such a counter-revolving configuration and consistent
with the observational data.
  In the present paper, we analytically investigate the three-body problem in
this particular case of retrograde resonances. We therefore define a new set of
canonical variables allowing to express correctly the resonance angles and
obtain the Hamiltonian of a system harboring planets revolving in opposite
directions. The acquiring of an analytical ""rail"" may notably contribute to a
deeper understanding of our numerical investigation and provides the major
structures related to the stability properties. A comparison between our
analytical and numerical results is also carried out.",0902.0428v1
2009-02-12,Controlling a magnetic Feshbach resonance with laser light,"The capability to tune the strength of the elastic interparticle interaction
is crucial for many experiments with ultracold gases. Magnetic Feshbach
resonances are a tool widely used for this purpose, but future experiments
would benefit from additional flexibility such as spatial modulation of the
interaction strength on short length scales. Optical Feshbach resonances offer
this possibility in principle, but suffer from fast particle loss due to
light-induced inelastic collisions. Here we show that light near-resonant with
a molecular bound-to-bound transition can be used to shift the magnetic field
at which a magnetic Feshbach resonance occurs. This makes it possible to tune
the interaction strength with laser light and at the same time induce
considerably less loss than an optical Feshbach resonance would do.",0902.2151v1
2009-03-12,Stability of a BEC with Higher-order Interactions near a Feshbach Resonance,"We consider the stability of an ultracold trapped Bose-Einstein condensate
near a Feshbach resonance. Using a modified Gross-Pitaevskii equation that
includes higher-order terms and a multi-channel model of Feshbach resonances,
we find regions where stability can be enhanced or suppressed around
experimentally measured resonances. We suggest a number of ways to probe the
stability diagram. Using scattering length zero-crossings huge deviations are
founds for the critical particle number. Effects are enhanced for narrow
resonances or tighter traps. Macroscopic tunneling of the condensate is another
possible probe for higher-order interactions, however, to see this requires
very narrow resonances or very small particle numbers.",0903.2261v2
2009-03-25,Analytic properties of the scattering amplitude and resonances parameters in a meson exchange model,"The analytic properties of scattering amplitudes provide important
information. Besides the cuts, the poles and zeros on the different Riemann
sheets determine the global behavior of the amplitude on the physical axis.
Pole positions and residues allow for a parameterization of resonances in a
well-defined way, free of assumptions for the background and energy dependence
of the resonance part. This is a necessary condition to relate resonance
contributions in different reactions. In the present study, we determine the
pole structure of pion-nucleon scattering in an analytic model based on meson
exchange. For this, the sheet structure of the amplitude is determined. To show
the precision of the resonance extraction and discuss phenomena such as
resonance interference, we discuss the S11 amplitude in greater detail.",0903.4337v2
2009-04-27,Composite metamaterials with dual-band magnetic resonances in the terahertz frequency regime,"Composite metamaterials(CMMs) combining a subwavelength metallic hole array
(i.e. one-layer fishnet structure) and an array of split-ring resonators(SRRs)
on the same board are fabricated with gold films on silicon wafer. Transmission
measurements of the CMMs in the terahertz range have been performed. Dual-band
magnetic resonances, namely, a LC resonance at 4.40 THz and an additional
magnetic resonance at 8.64 THz originating from the antiparallel current in
wire pairs in the CMMs are observed when the electrical field polarization of
the incident light is parallel to the gap of the component SRR. The numerical
simulations agree well with the experimental results and further clarify the
nature of the dual-band magnetic resonances.",0904.4078v1
2009-07-16,On resonant and non-resonant origin of double-mode Cepheid pulsation,"Double-mode Cepheid behaviour may arise either from non-resonant or resonant
mode interaction. Inclusion of turbulent convection into pulsation codes by
Kollath et al. (1998) led to stable double-mode F+1O Cepheid pulsation.
However, our recent computations (Smolec & Moskalik 2008) indicate, that these
models resulted from incorrect neglect of negative buoyancy effects. Once these
effects are taken into account, only some resonant double-mode models could be
found. These models do not solve the puzzle of double-mode phenomenon, as they
are restricted to narrow parameter ranges. For majority of the observed
double-mode Cepheids non-resonant mechanism has to be operational.",0907.2802v1
2009-07-16,Carbon nanotubes as ultra-high quality factor mechanical resonators,"We have observed the transversal vibration mode of suspended carbon nanotubes
at millikelvin temperatures by measuring the single-electron tunneling current.
The suspended nanotubes are actuated contact-free by the radio frequency
electric field of a nearby antenna; the mechanical resonance is detected in the
time-averaged current through the nanotube. Sharp, gate-tuneable resonances due
to the bending mode of the nanotube are observed, combining resonance
frequencies of up to \nu_0 = 350 MHz with quality factors above Q = 10^5, much
higher than previously reported results on suspended carbon nanotube
resonators. The measured magnitude and temperature dependence of the Q-factor
shows a remarkable agreement with the intrinsic damping predicted for a
suspended carbon nanotube. By adjusting the RF power on the antenna, we find
that the nanotube resonator can easily be driven into the non-linear regime.",0907.2823v2
2009-07-21,Resonantly driven wobbling kinks,"The amplitude of oscillations of the freely wobbling kink in the $\phi^4$
theory decays due to the emission of second-harmonic radiation. We study the
compensation of these radiation losses (as well as additional dissipative
losses) by the resonant driving of the kink. We consider both direct and
parametric driving at a range of resonance frequencies. In each case, we derive
the amplitude equations which describe the evolution of the amplitude of the
wobbling and the kink's velocity. These equations predict multistability and
hysteretic transitions in the wobbling amplitude for each driving frequency --
the conclusion verified by numerical simulations of the full partial
differential equation. We show that the strongest parametric resonance occurs
when the driving frequency equals the natural wobbling frequency and not double
that value. For direct driving, the strongest resonance is at half the natural
frequency, but there is also a weaker resonance when the driving frequency
equals the natural wobbling frequency itself. We show that this resonance is
accompanied by translational motion of the kink.",0907.3615v1
2009-07-22,Mass-Matching in Higgsless,"Modern extra-dimensional Higgsless scenarios rely on a mass-matching between
fermionic and bosonic KK resonances to evade constraints from precision
electroweak measurements. After analyzing all of the Tevatron and LEP bounds on
these so-called Cured Higgsless scenarios, we study their LHC signatures and
explore how to identify the mass-matching mechanism, the key to their
viability. We find singly and pair produced fermionic resonances show up as
clean signals with 2 or 4 leptons and 2 hard jets, while neutral and charged
bosonic resonances are visible in the dilepton and leptonic WZ channels,
respectively. A measurement of the resonance masses from these channels shows
the matching necessary to achieve $S\simeq 0$. Moreover, a large single
production of KK-fermion resonances is a clear indication of compositeness of
SM quarks. Discovery reach is below 10 fb$^{-1}$ of luminosity for resonances
in the 700 GeV range.",0907.3931v1
2009-08-12,"Resonance Phenomenon Related to Spectral Singularities, Complex Barrier Potential, and Resonating Waveguides","A peculiar property of complex scattering potentials is the appearance of
spectral singularities. These are energy eigenvalues for certain scattering
states that similarly to resonance states have infinite reflection and
transmission coefficients. This property reveals an interesting resonance
effect with possible applications in waveguide physics. We study the spectral
singularities of a complex barrier potential and explore their application in
designing a waveguide that functions as a resonator. We show that for the
easily accessible sizes of the waveguide and its gain region, we can realize
the spectral singularity-related resonance phenomenon at almost every
wavelength within the visible spectrum or outside it.",0908.1713v3
2009-08-24,"Spectral projection, residue of the scattering amplitude, and Schrodinger group expansion for barrier-top resonances","We study the spectral projection associated to a barrier-top resonance for
the semiclassical Schrodinger operator. First, we prove a resolvent estimate
for complex energies close to such a resonance. Using that estimate and an
explicit representation of the resonant states, we show that the spectral
projection has a semiclassical expansion in integer powers of h, and compute
its leading term. We use this result to compute the residue of the scattering
amplitude at such a resonance. Eventually, we give an expansion for large times
of the Schrodinger group in terms of these resonances.",0908.3444v1
2009-08-25,Toolbox of resonant quantum gates in Circuit QED,"We propose the implementation of fast resonant gates in circuit quantum
electrodynamics for quantum information processing. We show how a suitable
utilization of three-level superconducting qubits inside a resonator
constitutes a key tool to perform diverse two-qubit resonant gates, improving
the operation speed when compared to slower dispersive techniques. To
illustrate the benefit of resonant two-qubit gates in circuit QED, we consider
the implementation of a two-dimensional cluster state in an array of N x N
superconducting qubits by using resonant controlled-phase (CPHASE) and
one-qubit gates, where the generation time grows linearly with N. For N=3, and
taking into account decoherence mechanisms, a fidelity over 60% for the
generation of this cluster state is obtained.",0908.3673v3
2009-09-12,Fermion Resonances on Multi-field Thick Branes,"Motivated by the recent work on the fermion resonances on scalar-constructed
thick branes (arXiv:0901.3543 and arXiv:0904.1785), we extend the idea to
multi-scalar generated thick branes and complete previous work. The fermion
localization and resonances on the three-field and two-field thick branes are
investigated. With the Numerov method, our numerical results show that the
resonance states also exist in the brane besides the single-field thick branes
and the two-field thick branes in the former cases. This interesting phenomenon
is related to the internal structure of the brane and the coupling of fermions
and scalars. We find that the Kaluza-Klein chiral decomposition of massive
fermion resonances is the parity-chiral decomposition. For the couplings
$\eta\bar{\Psi}\phi^{k}\chi\rho\Psi$ and $\eta\bar{\Psi}\phi^{k}\chi\rho\Psi$
for three-field and two-field models with odd positive $k$, respectively, the
number of the resonant states decreases with $k$. This result is opposite to
the one obtained in the single-field de Sitter thick brane (arXiv:0904.1785).",0909.2312v1
2009-09-30,Origin of resonances in chiral dynamics,"The nature of baryon resonances is studied in the dynamical chiral
coupled-channel approach for meson-baryon scattering. In general, origin of
resonances in two-body scattering can be classified into two categories:
dynamically generated states and genuine elementary particles. We demonstrate
that the genuine contribution in the loop function can be excluded by adopting
a natural renormalization scheme. The origin of resonances can be studied by
looking at the effective interaction in the natural renormalization scheme,
which is deduced from the phenomenological amplitude fitted to experimental
data. Applying this method to the baryon resonances, we find that the dominant
component for the Lambda(1405) resonance is dynamical, while a genuine
contribution plays a substantial role for the structure of the N(1535).",0909.5531v1
2009-11-06,Cavity optomechanics with ultra-high Q crystalline micro-resonators,"We present the first observation of optomechanical coupling in ultra-high Q
crystalline whispering-gallery-mode (WGM) resonators. The high purity of the
crystalline material enables optical quality factors in excess of 10^{10} and
finesse exceeding 10^{6}. Simultaneously, mechanical quality factors greater
than 10^{5} are obtained, still limited by clamping losses. Compared to
previously demonstrated cylindrical resonators, the effective mass of the
mechanical modes can be dramatically reduced by the fabrication of CaF2
microdisc resonators. Optical displacement monitoring at the 10^{-18}
m/sqrt{Hz}-level reveals mechanical radial modes at frequencies up to 20 MHz,
corresponding to unprecedented sideband factors (>100). Together with the weak
intrinsic mechanical damping in crystalline materials, such high sindeband
factors render crystalline WGM micro-resonators promising for backaction
evading measurements, resolved sideband cooling or optomechanical normal mode
splitting. Moreover, these resonators can operate in a regime where
optomechanical Brillouin lasing can become accessible.",0911.1178v2
2010-01-11,Validation of FDTD-2D for high-Q resonances description,"The objective of the study is to assess the accuracy of a standard FDTD code
in description of high-Q resonances such as whispering-gallery-mode (WGM) ones
excited in circular dielectric resonators. To achieve the goal, we consider
circular resonators excited by line currents and extract the data on FDTD
accuracy from comparisons between the FDTD-solution and the exact one obtained
by the Mie-series solutions. The near-field and far-field characteristics are
studied for resonators of various sizes, made of quartz and silicon. Both E -
and H - polarizations are considered. The computational error, i.e. a resonance
frequency shift observed for the FDTD solution, is analyzed and compared for
several WGMs having different Q-factors.",1001.1733v1
2010-01-25,Strong coupling between single-electron tunneling and nano-mechanical motion,"Nanoscale resonators that oscillate at high frequencies are useful in many
measurement applications. We studied a high-quality mechanical resonator made
from a suspended carbon nanotube driven into motion by applying a periodic
radio frequency potential using a nearby antenna. Single-electron charge
fluctuations created periodic modulations of the mechanical resonance
frequency. A quality factor exceeding 10^5 allows the detection of a shift in
resonance frequency caused by the addition of a single-electron charge on the
nanotube. Additional evidence for the strong coupling of mechanical motion and
electron tunneling is provided by an energy transfer to the electrons causing
mechanical damping and unusual nonlinear behavior. We also discovered that a
direct current through the nanotube spontaneously drives the mechanical
resonator, exerting a force that is coherent with the high-frequency resonant
mechanical motion.",1001.4372v1
2010-03-03,Double Resonance Nanolaser based on Coupled Slit-hole Resonator Structures,"This work investigates a kind of metallic magnetic cavity based on slit-hole
resonators (SHRs). Two orthogonal hybrid magnetic resonance modes of the cavity
with a large spatial overlap are predesigned at the wavelengths of 980 nm and
1550 nm. The Yb-Er co-doped material serving as a gain medium is set in the
cavity; this enables the resonator to have high optical activity. The numerical
result shows that the strong lasing at 1550 nm may be achieved when the cavity
array is pumped at 980 nm. This double resonance nanolaser array has potential
applications in future optical devices and quantum information techniques.",1003.0822v1
2010-03-12,"Frequency Conversion: Side-band cooling, state-swapping, and coherent control of mechanical resonators","Sideband cooling is a technique that potentially allows mechanical resonators
to be prepared in their ground states, important for future applications in
quantum technologies. Tian has recently shown that side-band cooling can be
implemented by modulating the coupling between a nano-resonator and a
superconducting oscillator, a process of frequency conversion [L. Tian, PRB 79,
193407 (2009)]. While side-band cooling is usually treated in the steady-state
regime, the effective resonant coupling will also generate near perfect
state-swapping from the superconductor to the mechanical resonator. We perform
numerical simulations of this system, examining the ground-state cooling
achieved by the state-swapping. Further, we show that the superconducting
oscillator can be used to control the amplitude and phase of the resonator,
while simultaneously cooling it, and thus act as a coherent ""quantum feedback
controller"".",1003.2653v3
2010-03-30,Optical Resonators in Current and Future Experiments of the ALPS Collaboration,"The ALPS collaboration runs a ""light shining through a wall"" (LSW) experiment
to search for weakly interacting sub-eV particles (WISPs). Its sensitivity is
significantly enhanced by the incorporation of a large-scale production
resonator and a small-scale high-power resonant second harmonic generator. Here
we report on important experimental details and limitations of these resonators
and derive recommendations for further experiments. A very promising
improvement for a future ALPS experiment is the incorporation of an additional
large-scale regeneration resonator. We present a rough sketch of how to combine
a regeneration resonator with a single-photon counter (SPC) as detector for
regenerated photons.",1003.5867v1
2010-04-03,Fano Regime of Transport through Open Quantum Dots,"We analyze a quantum dot strongly coupled to the conducting leads via quantum
point contacts - Fano regime of transport - and report a variety of resonant
states which demonstrate the dominance of the interacting resonances in the
scattering process in a low confining potential. There are resonant states
similar to the eigenstates of the isolated dot, whose widths increase with
increasing the coupling strength to the environment, and hybrid resonant
states. The last ones are approximatively obtained as a linear combination of
eigenstates with the same parity in the lateral direction, and the
corresponding resonances show the phenomena of resonance trapping or level
repulsion. The existence of the hybrid modes suggests that the open quantum dot
behaves in the Fano regime like an artificial molecule.",1004.0472v2
2010-04-30,Top Quarks as a Window to String Resonances,"We study the discovery potential of string resonances decaying to $t\bar{t}$
final state at the LHC. We point out that top quark pair production is a
promising and an advantageous channel for studying such resonances, due to
their low Standard Model background and unique kinematics. We study the
invariant mass distribution and angular dependence of the top pair production
cross section via exchanges of string resonances. The mass ratios of these
resonances and the unusual angular distribution may help identify their
fundamental properties and distinguish them from other new physics. We find
that string resonances for a string scale below 4 TeV can be detected via the
$t\bar{t}$ channel, either from reconstructing the $t\bar{t}$ semi-leptonic
decay or recent techniques in identifying highly boosted tops.",1004.5441v1
2010-06-11,Extraction of Electromagnetic Transition Form Factors for Nucleon Resonances within a Dynamical Coupled-Channels Model,"We explain the application of a recently developed analytic continuation
method to extract the electromagnetic transition form factors for the nucleon
resonances ($N^*$) within a dynamical coupled-channel model of meson-baryon
reactions.Illustrative results of the obtained $N^*\rightarrow \gamma N$
transition form factors, defined at the resonance pole positions on the complex
energy plane, for the well isolated $P_{33}$ and $D_{13}$, and the complicated
$P_{11}$ resonances are presented. A formula has been developed to give an
unified representation of the effects due to the first two $P_{11}$ poles,
which are near the $\pi\Delta$ threshold, but are on different Riemann sheets.
We also find that a simple formula, with its parameters determined in the
Laurent expansions of $\pi N \rightarrow \pi N$ and $\gamma N \rightarrow\pi N$
amplitudes, can reproduce to a very large extent the exact solutions of the
considered model at energies near the real parts of the extracted resonance
positions. We indicate the differences between our results and those extracted
from the approaches using the Breit-Wigner parametrization of resonant
amplitudes to fit the data.",1006.2196v1
2010-06-28,Separation of bacterial spores from flowing water in macro-scale cavities by ultrasonic standing waves,"The separation of micron-sized bacterial spores (Bacillus cereus) from a
steady flow of water through the use of ultrasonic standing waves is
demonstrated. An ultrasonic resonator with cross-section of 0.0254 m x 0.0254 m
has been designed with a flow inlet and outlet for a water stream that ensures
laminar flow conditions into and out of the resonator section of the flow tube.
A 0.01905-m diameter PZT-4, nominal 2-MHz transducer is used to generate
ultrasonic standing waves in the resonator. The acoustic resonator is 0.0356 m
from transducer face to the opposite reflector wall with the acoustic field in
a direction orthogonal to the water flow direction. At fixed frequency
excitation, spores are concentrated at the stable locations of the acoustic
radiation force and trapped in the resonator region. The effect of the
transducer voltage and frequency on the efficiency of spore capture in the
resonator has been investigated. Successful separation of B. cereus spores from
water with typical volume flow rates of 40-250 ml/min has been achieved with
15% efficiency in a single pass at 40 ml/min.",1006.5467v1
2010-07-31,Weakly-bound rare isotopes with a coupled-channel approach that includes resonant levels,"The question of how the scattering cross section changes when the spectra of
the colliding nuclei have low-excitation particle-emitting resonances is
explored using a multi-channel algebraic scattering (MCAS) method. As a test
case, the light-mass nuclear target 8Be, being particle-unstable, has been
considered. Nucleon-nucleus scattering cross sections, as well as the spectra
of the compound nuclei formed, have been determined from calculations that do,
and do not, consider particle emission widths of the target nuclear states. The
resonant character of the unstable excited states introduces a problem because
the low-energy tails of these resonances can intrude into the sub-threshold,
bound-state region. This unphysical behaviour needs to be corrected by
modifying, in an energy-dependent way, the shape of the target resonances from
the usual Lorentzian one. The resonance function must smoothly reach zero at
the elastic threshold. Ways of achieving this condition are explored in this
paper.",1008.0049v1
2010-08-18,Superposition of Inductive and Capacitive Coupling in Superconducting LC Resonators,"We present an experimental investigation of lumped-element superconducting LC
resonators designed to provide different types of coupling to a transmission
line. We have designed four resonator geometries including dipole and
quadrupole configured inductors connected in parallel with low loss SiNx
dielectric parallel-plate capacitors. The design of the resonator allows a
small change in the symmetry of the inductor or grounding of the capacitor to
allow LC resonators with: 1) inductive coupling, 2) capacitive coupling, 3)
both types of coupling, or 4) greatly reduced coupling. We measured all four
designs at a temperature of 30mK at different values of power. We compare the
extracted data from the four resonator types and find that both capacitive and
inductive coupling can be included and that when left off, only a minor change
in the circuit design is necessary. We also find a variation in the measured
loss tangent of less than a few percent, which is a test of the systematic
precision of the measurement technique.",1008.3130v1
2010-08-30,A closer look at string resonances in dijet events at the LHC,"The first string excited state can be observed as a resonance in dijet
invariant mass distributions at the LHC, if the scenario of low-scale string
with large extra dimensions is realized. A distinguished property of the dijet
resonance by string excited states from that the other ""new physics"" is that
many almost degenerate states with various spin compose a single resonance
structure. It is examined that how we can obtain evidences of low-scale string
models through the analysis of angular distributions of dijet events at the
LHC. Some string resonance states of color singlet can obtain large mass shifts
through the open string one-loop effect, or through the mixing with closed
string states, and the shape of resonance structure can be distorted. Although
the distortion is not very large (10% for the mass squared), it might be able
to observe the effect at the LHC, if gluon jets and quark jets could be
distinguished in a certain level of efficiency.",1008.4989v2
2010-09-19,Effect of spin transfer torque on the magnetic domain wall ferromagnetic resonance frequency in the nanowires,"We investigate the influence of the domain wall ferromagnetic resonance
frequency on the spin transfer torque in a ferromagnetic nanowire. By employing
micromagnetic simulations with the spin transfer torque, we find that the
domain wall resonance frequency decreases with increasing spin polarized
current density, when there is no change in the resonance frequency of the
domain itself. Surprisingly, the variation of the resonance frequency is
remarkable (> 1.6 GHz) with the spin transfer torque even though the domain
wall is pinned. Since the presented domain wall ferromagnetic resonance study
has been performed for the pinned domain wall, the contributions of extrinsic
defects are excluded. It is strong advantages of the present study, since the
effects of extrinsic pinning sites are inevitable in the imaging or transport
measurements.",1009.3618v1
2010-09-26,Optical and modal features of hemielliptic dielectric lenses,"Any dielectric lens has a finite closed boundary and therefore is, in fact,
an open dielectric resonator capable of supporting resonant modes whose
Q-factor depends of the lens parameters (size, shape, and material). The
hemielliptic lens, that is an essential building block of many mm-wave and THz
antennas, is not an exception: it supports the so-called halfbowtie (HBT)
resonances that can strongly affect performance of such antennas. In this paper
we illustrate the interplay between the optical and modal features in the
electromagnetic behaviour of hemielliptic lenses and highlight the drastic
influence of the HBT resonances on radiation characteristics of lens antennas.
We also discuss the difficulties associated with accurate description of the
resonant phenomena in compact-size hemielliptic lenses with conventional
techniques and provide recommendations on how to minimize the parasitic impact
of HBT resonances on the antenna performance.",1009.5114v2
2010-10-18,Feshbach resonances in the 6Li-40K Fermi-Fermi mixture: Elastic versus inelastic interactions,"We present a detailed theoretical and experimental study of Feshbach
resonances in the 6Li-40K mixture. Particular attention is given to the
inelastic scattering properties, which have not been considered before. As an
important example, we thoroughly investigate both elastic and inelastic
scattering properties of a resonance that occurs near 155 G. Our theoretical
predictions based on a coupled channels calculation are found in excellent
agreement with the experimental results. We also present theoretical results on
the molecular state that underlies the 155G resonance, in particular concerning
its lifetime against spontaneous dissociation. We then present a survey of
resonances in the system, fully characterizing the corresponding elastic and
inelastic scattering properties. This provides the essential information to
identify optimum resonances for applications relying on interaction control in
this Fermi-Fermi mixture.",1010.3662v2
2010-10-20,All-optical diode action in asymmetric nonlinear photonic multilayers with perfect transmission resonances,"Light propagation in asymmetric Kerr-nonlinear multilayers with perfect
transmission resonances is theoretically investigated. It is found that hybrid
Fabry-P\'erot/photonic-crystal structures of the type (BA)^k(AB)^k(AABB)^m
exhibit both pronounced unidirectionality (due to strong spatial asymmetry of
the resonant mode) and high transmission (due to the existence of a perfect
transmission resonance). This results in nonlinear optical diode action with
low reflection losses without need for a pumping beam or input pulse
modulation. By slightly perturbing the perfect transmission resonance
condition, the operating regime of the optical diode can be tuned, with a
trade-off between minimizing the reflection losses and maximizing the frequency
bandwidth where unidirectional transmission exists. Optical diode action is
demonstrated in direct numerical simulation, showing >92% transmittance in one
direction and about 22% in the other. The effect of perfect transmission
resonance restoration induced by nonlinearity was observed analytically and
numerically. The proposed geometry is shown to have advantages over previously
reported designs based on photonic quasicrystals.",1010.4274v2
2010-11-05,Hadron resonances generated from the dynamics of the lightest scalar ones,"We have studied the interactions of the scalar resonances f_0(980) and
a_0(980) with the vector resonance \phi(1020) and with the lightest
pseudoscalars \pi, K, \eta and \eta'. We first obtain the interaction kernels
without including any new free parameter. Afterwards, the interaction kernels
are unitarized and the final S-wave amplitudes result. We find that these
interactions are very rich and generate a large amount of pseudoscalar
resonances including the K(1460), \pi(1300), \pi(1800), \eta(1475) and X(1835)
resonances. The f_0(980)\phi(1020) self-interactions give rise to the
\phi(2170) resonance. For realistic choices of the parameters we also obtain an
isovector companion in the same mass region from the a_0(980) \phi(1020)
interactions.",1011.1448v1
2010-12-08,Elementary excitations in charge-tunable InGaAs quantum dots studied by resonant Raman and resonant photoluminescence spectroscopy,"We report on resonant optical spectroscopy of self-assembled InGaAs quantum
dots in which the number of electrons can accurately be tuned to N=0,1,2 by an
external gate voltage. Polarization, wave vector and magnetic field dependent
measurements enable us to clearly distinguish between resonant Raman and
resonant photoluminescence processes. The Raman spectra for N=1 and 2 electrons
considerably differ from each other. In particular, for N=2, the quantum-dot
He, the spectra exhibit both singlet and triplet transitions reflecting the
elementary many-particle interaction. Also the resonant photoluminescence
spectra are significantly changing by varying the number of electrons in the
QDs. For N=1 we observe strong polaronic effects which are suppressed for N=2.",1012.1762v1
2011-01-04,Plasmonically induced transparent magnetic resonance in a metallic metamaterial composed of asymmetric double bars,"We demonstrate that the trapped magnetic resonance mode can be induced in an
asymmetric double-bar structure for electromagnetic waves normally incident
onto the double-bar plane, which mode otherwise cannot be excited if the double
bars are equal in length. By adjusting the structural geometry, the trapped
magnetic resonance becomes transparent with little resonance absorption when it
happens in the dipolar resonance regime, a phenomenon so-called plasmonic
analogue of electromagnetically induced transparency. Accordingly, the
additional magnetic resonance by introducing asymmetry is explained as a result
of nonlinear plasmon coupling.",1101.0739v1
2011-01-13,Interaction-enhanced double resonance in cold gases,"A new type of double-resonance spectroscopy of a quantum gas based on
interaction-induced frequency modulation of a probe transition has been
considered. Interstate interaction of multilevel atoms causes a
coherence-dependent collisional shift of the transition between the atomic
states |1> and |2> due to a nonzero population of the state |3>. Thus, the
frequency of the probe transition |1>-|2> experiences oscillations associated
with the Rabi oscillations between the states |1> and |3> under continuous
excitation of the drive resonance |1>-|3>. Such a dynamic frequency shift leads
to a change in the electromagnetic absorption at the probe frequency and,
consequently, greatly enhances the sensitivity of double-resonance spectroscopy
as compared to traditional ""hole burning"", which is solely due to a decrease in
the population of the initial state |1>. In particular, it has been shown that
the resonance linewidth is determined by the magnitude of the contact shift and
the amplitude of the drive field and does not depend on the static field
gradient. The calculated line shape and width agree with the low-temperature
electron-nuclear double-resonance spectra of two-dimensional atomic hydrogen.",1101.2559v2
2011-02-09,Observation of Little-Parks oscillations at temperatures much lower than the critical temperature using a GHz resonator,"It is demonstrated that a thin-film Fabry-Perot superconducting resonator can
be used to reveal the Little-Parks (LP) effect even at temperatures much lower
than the critical temperature. A pair of parallel nanowires is incorporated
into the resonator at the point of a supercurrent antinode. As magnetic field
is ramped, the Meissner current develops, changing the kinetic inductance of
the wires and, correspondingly, the resonance frequency of the resonator, which
can be detected. The LP oscillation are revealed as a periodic set of distorted
parabolas observed in the transmission of the resonator and corresponding to
the states of the wire loop having different vorticities. We also report a
direct observation of single and double phase slip events and their statistical
analysis.",1102.1990v1
2011-02-14,Possibility of narrow resonances in nucleon-nucleon channels,"Compound states manifest themselves as bound states, resonances, or
primitives, and their character is determined by their interaction with the
continuum. If the interaction experiences a perturbation, a compound state can
change its manifestation. Phase analysis of nucleon-nucleon scattering
indicates the existence of primitives in the 3S1, 1S0, and 3P0 channels.
Electromagnetic interaction can shift primitives from the unitary cut, turning
them into narrow resonances. We evaluate this effect on the 1S0 proton-proton
scattering channel within the framework of the Simonov-Dyson model. We show
that electromagnetic interaction turns a primitve with a mass of 2000 MeV into
a dibaryon resonance of approximately the same mass and a width of 260 keV.
Narrow resonances of a similar nature may occur in other nucleon-nucleon
channels. Experimental confirmation of the existence of narrow resonances would
have important implications for the theory of nucleon-nucleon interaction.",1102.2718v2
2011-02-17,Thermal tunability in terahertz metamaterials fabricated on strontium titanate single crystal substrates,"We report an experimental demonstration of thermal tuning of resonance
frequency in a planar terahertz metamaterial consisting of a gold split-ring
resonator array fabricated on a bulk single crystal strontium titanate (SrTiO3)
substrate. Cooling the metamaterial starting from 409 K down to 150 K causes
about 50% shift in resonance frequency as compare to its room temperature
resonance, and there is very little variation in resonance strength. The
resonance shift is due to the temperature-dependent refractive index (or the
dielectric constant) of the strontium titanate. The experiment opens up avenues
for designing tunable terahertz devices by exploiting the temperature sensitive
characteristic of high dielectric constant substrates and complex metal oxide
materials.",1102.3507v1
2011-02-21,Multi-resonance of energy transport and absence of heat pump in a force-driven lattice,"Energy transport control in low dimensional nano-scale systems has attracted
much attention in recent years. In this paper, we investigate the energy
transport properties of Frenkel-Kontorova lattice subject to a periodic driving
force, in particular, the resonance behavior of the energy current by varying
the external driving frequency. It is discovered that in certain parameter
ranges, multiple resonance peaks, instead of a single resonance, emerge. By
comparing the nonlinear lattice model with a harmonic chain, we unravel the
underlying physical mechanism for such resonance phenomenon. Other parameter
dependencies of the resonance behavior are examined as well. Finally, we
demonstrate that heat pumping is actually absent in this force-driven model.",1102.4113v2
2011-03-10,Raman-assisted Rabi resonances in two-mode cavity QED,"The dynamics of a vibronic system in a lossy two-mode cavity is studied, with
the first mode being resonant to the electronic transition and the second one
being nearly resonant due to Raman transitions. We derive analytical solutions
for the dynamics of this system. For a properly chosen detuning of the second
mode from the exact Raman resonance, we obtain conditions that are closely
related to the phenomenon of Rabi resonance as it is well known in laser
physics. Such resonances can be observed in the spontaneous emission spectra,
where the spectrum of the second mode in the case of weak Raman coupling is
enhanced substantially.",1103.2032v2
2011-03-29,Two energy scales in the magnetic resonance spectrum of electron and hole doped pnictide superconductors,"We argue that a multiband superconductor with sign-changing gaps may have
multiple spin resonances. We calculate the RPA-based spin resonance spectra of
a pnictide superconductor by using the five band tight-binding model or
angle-resolved photoemission spectroscopy (ARPES) Fermi surface (FS) and
experimental values of superconducting (SC) gaps. The resonance spectra split
in both energy and momenta due to the effects of multiband and multiple gaps in
$s^{\pm}-$pairing; the higher energy peak appears around the commensurate
momenta due to scattering between $\alpha-$FS to $\gamma/\delta-$FS pockets.
The second resonance is incommensurate coming from $\beta-$FS to
$\gamma/\delta-$FS scatterings and its $q-$vector is doping-dependent and hence
on the FS topology. Energies of both resonances $\omega^{1,2}_{res}$ are
strongly doping dependent and are proportional to the gap amplitudes at the
contributing FSs. We also discuss the evolution of the spin excitation spectra
with various other possible gap symmetries, which may be relevant when either
both the electron pockets or both the hole pockets completely disappear.",1103.5787v1
2011-04-06,Signatures of Resonant Super-Partner Production with Charged-Current Decays,"Hadron collider signatures of new physics are investigated in which a primary
resonance is produced that decays to a secondary resonance by emitting a
W-boson, with the secondary resonance decaying to two jets. This topology can
arise in supersymmetric theories with R-parity violation where the lightest
supersymmetric particles are either a pair of squarks, or a slepton - sneutrino
pair. The resulting signal can have a cross section consistent with the Wjj
observation reported by the CDF collaboration, while remaining consistent with
earlier constraints. Other observables that can be used to confirm this
scenario include a significant charge asymmetry in the same channel at the LHC.
With strongly interacting resonances such as squarks, pair production
topologies additionally give rise to 4 jet and WW + 4 jet signatures, each with
two equal-mass dijet resonances within the 4 jets.",1104.1002v3
2011-04-15,Resonance saturation in the odd-intrinsic parity sector of low-energy QCD,"Using the large N_C approximation we have constructed the most general chiral
resonance Lagrangian in the odd-intrinsic parity sector that can generate low
energy chiral constants up to O(p^6). Integrating out the resonance fields
these O(p^6) constants are expressed in terms of resonance couplings and
masses. The role of eta' is discussed and its contribution is explicitly
factorized. Using the resonance basis we have also calculated two QCD Green
functions of currents: <VVP> and <VAS> and found, imposing high energy
constraints, additional relations for resonance couplings. We have studied
several phenomenological implications based on these correlators from which let
us mention here our prediction for the pi0-pole contribution to the muon g-2
factor: $a_\mu^{\pi^0} = 65.8(1.2)\times 10^{-11}$.",1104.3137v1
2011-05-09,Fano Resonances of Plasmonic Nanodisk,"The Fano resonance of a single symmetry broken Ag nanodisk under a normal
incidence was investigated by using finite-difference time-domain (FDTD)
simulations. The asymmetry line shape of the Fano resonance was controlled by
modifying the open angle of the nanodisk, and this Fano splitting was
demonstrated as the result of the overlap between the broad dipolar and narrow
quadrupolar modes, which could be strengthened by enlarging the radius of the
nanodisk. A semi-analytical method was developed to calculate the plasmon
hybridization, which was used to analyze the sub-process of the quadru Fano
resonance. With the good agreement between theoretical calculations and FDTD
simulations, the suggested method provides a way to investigate and control the
Fano resonance inside a single planar nanostructure, and can be applied to the
future high-performance Fano resonance sensors.",1105.1568v1
2011-06-13,Parametric amplification in single-walled carbon nanotube nanoelectromechanical resonators,"The low quality factor (Q) of Single-walled carbon nanotube (SWNT) resonators
has limited their sensitivity in sensing application. To this end, we employ
the technique of parametric amplification by modulating the spring constant of
SWNT resonators at twice the resonant frequency, and achieve 10 times Q
enhancement. The highest Q obtained at room temperature is around ~700, which
is 3-4 times better than previous Q record reported for doubly-clamped SWNT
resonators. Furthermore, efficient parametric amplification is found to only
occur in the catenary vibration regime. Our results open up the possibility to
employ light-weight and high-Q carbon nanotube resonators in single molecule
and atomic mass sensing.",1106.2531v2
2011-06-24,On the application of radio frequency voltages to ion traps via helical resonators,"Ions confined using a Paul trap require a stable, high voltage and low noise
radio frequency (RF) potential. We present a guide for the design and
construction of a helical coil resonator for a desired frequency that maximises
the quality factor for a set of experimental constraints. We provide an
in-depth analysis of the system formed from a shielded helical coil and an ion
trap by treating the system as a lumped element model. This allows us to
predict the resonant frequency and quality factor in terms of the physical
parameters of the resonator and the properties of the ion trap. We also compare
theoretical predictions with experimental data for different resonators, and
predict the voltage applied to the ion trap as a function of the Q-factor,
input power and the properties of the resonant circuit.",1106.5013v3
2011-08-01,On Resonant Waves in Lattices,"Mathematical modeling of resonant waves propagating in 2D periodic infinite
lattices is conducted. Rectangular-cell, triangular-cell and hexagonal-cell
lattices are considered. Eigenvalues (here eigenfrequencies) of steady-state
problems are determined, and dispersion properties of free waves are described.
We show that the frequency spectra of the models possess several resonant
points located both at the boundary of pass/stop bands and in the interior of a
pass band. Boundary value problems with a local monochromatic source are
explored, and peculiarities of resonant waves are revealed. Asymptotic
solutions are compared with the results of computer simulation. Special
attention is given to line-localized primitive waveforms at the resonance
frequencies and to the wave beaming phenomena at a resonant excitation.",1108.0357v1
2011-08-08,Coupling Bright and Dark Plasmonic Lattice Resonances,"We demonstrate the coupling of bright and dark Surface Lattice Resonances
(SLRs), which are collective Fano resonances in 2D plasmonic crystals. As a
result of this coupling, a frequency stop-gap in the dispersion relation of
SLRs is observed. The different field symmetries of the low and high frequency
SLR bands lead to pronounced differences in their coupling to free space
radiation. Standing waves of very narrow spectral width compared to localized
surface plasmon resonances are formed at the high frequency band edge, while
subradiant damping onsets at the low frequency band edge leading the resonance
into darkness. We introduce a coupled oscillator analog to the plasmonic
crystal, which serves to elucidate the physics of the coupled plasmonic
resonances and to estimate very high quality factors (Q>700) for SLRs, which
are the highest known for any 2D plasmonic crystal.",1108.1620v1
2011-08-08,A resonance interpretation for the nonmonotonic behavior of the phi-photoproduction cross section near threshold,"We study whether the nonmonotonic behavior found in the differential cross
section of the phi-meson photoproduction near threshold can be described by a
resonance. The resonant contribution is evaluated by using an effective
Lagrangian approach. We find that, with the assumption of a J^P=3/2^- resonance
with mass of 2.10 \pm 0.03 GeV and width of 0.465 \pm 0.141 GeV, LEPS data can
indeed be well described. The ratio of the helicity amplitudes A_1/2/A_3/2
calculated from the resulting coupling constants differs in sign from that of
the known D13(2080). We further find that the addition of this postulated
resonance can substantially improve the agreement between the existing
theoretical predictions and the recent omega photoproduction data if a large
value of the OZI evading parameter x_OZI = 12 is assumed for the resonance.",1108.1677v1
2011-08-09,Efimov Resonances in Ultracold Quantum Gases,"Ultracold atomic gases have developed into prime systems for experimental
studies of Efimov three-body physics and related few-body phenomena, which
occur in the universal regime of resonant interactions. In the last few years,
many important breakthroughs have been achieved, confirming basic predictions
of universal few-body theory and deepening our understanding of such systems.
We review the basic ideas along with the fast experimental developments of the
field, focussing on ultracold cesium gases as a well-investigated model system.
Triatomic Efimov resonances, atom-dimer Efimov resonances, and related
four-body resonances are discussed as central observables. We also present some
new observations of such resonances, supporting and complementing the set of
available data.",1108.1909v2
2011-08-15,An analysis method for asymmetric resonator transmission applied to superconducting devices,"We examine the transmission through nonideal microwave resonant circuits. The
general analytical resonance line shape is derived for both inductive and
capacitive coupling with mismatched input and output transmission impedances,
and it is found that for certain non-ideal conditions the line shape is
asymmetric. We describe an analysis method for extracting an accurate internal
quality factor ($Q_i$), the Diameter Correction Method (DCM), and compare it to
the conventional method used for millikelvin resonator measurements, the $\phi$
Rotation Method ($\phi$RM). We analytically find that the $\phi$RM
deterministically overestimates $Q_i$ when the asymmetry of the resonance line
shape is high, and that this error is eliminated with the DCM. A consistent
discrepancy between the two methods is observed when they are used to analyze
both simulations from a numerical linear solver and data from asymmetric
coplanar superconducting thin-film resonators.",1108.3117v3
2011-09-19,Note on resonance varieties,"We study the irreducibility of resonance varieties of graded rings over an
exterior algebra E with particular attention to Orlik-Solomon algebras. We
prove that for a stable monomial ideal in E the first resonance variety is
irreducible. If J is an Orlik- Solomon ideal of an essential central hyperplane
arrangement, then we show that its first resonance variety is irreducible if
and only if the subideal of J generated by all degree 2 elements has a 2-linear
resolution. As an application we characterize those hyperplane arrangements of
rank less than or equal to 3 where J is componentwise linear. Higher resonance
varieties are also considered. We prove results supporting a conjecture of
Schenck-Suciu relating the Betti numbers of the linear strand of J and its
first resonance variety. A counter example is constructed that this conjecture
is not true for arbitrary graded ideals.",1109.4015v1
2011-09-22,Dynamic manipulation of mechanical resonators in the high amplitude regime through optical backaction,"Cavity optomechanics enables active manipulation of mechanical resonators
through backaction cooling and amplification. This ability to control
mechanical motion with retarded optical forces has recently spurred a race
towards realizing a mechanical resonator in its quantum ground state. Here,
instead of quenching optomechanical motion, we demonstrate high amplitude
operation of nanomechanical resonators by utilizing a highly efficient phonon
generation process. In this regime, the nanomechanical resonators gain
sufficient energy from the optical field to overcome the large energy barrier
of a double well potential, leading to nanomechanical slow-down and zero
frequency singularity, as predicted by early theories . Besides fundamental
studies and interests in parametric amplification of small forces,
optomechanical backaction is also projected to open new windows for studying
discrete mechanical states, and to foster applications. Here we realize a
non-volatile mechanical memory element, in which bits are written and reset via
optomechanical backaction by controlling the mechanical damping across the
barrier. Our study casts a new perspective on the energy dynamics in coupled
mechanical resonator - cavity systems and enables novel functional devices that
utilize the principles of cavity optomechanics.",1109.4681v1
2011-09-23,Thin-film superconducting resonator tunable to the ground-state hyperfine splitting of $^{87}$Rb,"We describe a thin-film superconducting Nb microwave resonator, tunable to
within 0.3 ppm of the hyperfine splitting of $^{87}$Rb at $f_{Rb}=6.834683$
GHz. We coarsely tuned the resonator using electron-beam lithography,
decreasing the resonance frequency from 6.8637 GHz to 6.8278 GHz. For \emph{in
situ} fine tuning at 15 mK, the resonator inductance was varied using a
piezoelectric stage to move a superconducting pin above the resonator. We found
a maximum frequency shift of about 8.7 kHz per 60-nm piezoelectric step and a
tuning range of 18 MHz.",1109.5205v1
2011-09-26,Qubit state detection using the quantum Duffing oscillator,"We introduce a detection scheme for the state of a qubit, which is based on
resonant few-photon transitions in a driven nonlinear resonator. The latter is
parametrically coupled to the qubit and is used as its detector. Close to the
fundamental resonator frequency, the nonlinear resonator shows sharp resonant
few-photon transitions. Depending on the qubit state, these few-photon
resonances are shifted to different driving frequencies. We show that this
detection scheme offers the advantage of small back action, a large
discrimination power with an enhanced read-out fidelity, and a sufficiently
large measurement efficiency. A realization of this scheme in the form of a
persistent current qubit inductively coupled to a driven SQUID detector in its
nonlinear regime is discussed.",1109.5562v1
2011-12-04,Quantum liquid-crystal order in resonant atomic gases,"I review recent studies that predict quantum liquid-crystalline orders in
resonant atomic gases. As examples of such putative systems I will discuss an
s-wave resonant imbalanced Fermi gas and a p-wave resonant Bose gas. In the
former, the liquid-crystalline smectic, nematic and rich variety of other
descendant states emerge from strongly quantum- and thermally- fluctuating
Fulde-Ferrell and Larkin-Ovchinnikov states, driven by a competition between
resonant pairing and Fermi-surface mismatch. In the latter, at intermediate
detuning the p-wave resonant interaction generically drives Bose-condensation
at a finite momentum, set by a competition between atomic kinetic energy and
atom-molecule hybridization. Because of the underlying rotationally-invariant
environment of the atomic gas trapped isotropically, the putative striped
superfluid is a realization of a quantum superfluid smectic, that can melt into
a variety of interesting phases, such as a quantum nematic. I will discuss the
corresponding rich phase diagrams and transitions, as well the low-energy
properties of the phases and fractional topological defects generic to striped
superfluids and their fluctuation-driven descendants.",1112.0773v1
2011-12-11,A pre-Caloris synchronous rotation for Mercury,"The planet Mercury is locked in a spin-orbit resonance where it rotates three
times about its spin axis for every two orbits about the Sun. The current
explanation for this unique state assumes that the initial rotation of this
planet was prograde and rapid, and that tidal torques decelerated the planetary
spin to this resonance. When core-mantle boundary friction is accounted for,
capture into the 3/2 resonance occurs with a 26% probability, but the most
probable outcome is capture into one of the higher-order resonances. Here we
show that if the initial rotation of Mercury were retrograde, this planet would
be captured into synchronous rotation with a 68% probability. Strong spatial
variations of the impact cratering rate would have existed at this time, and
these are shown to be consistent with the distribution of pre-Calorian impact
basins observed by Mariner 10 and MESSENGER. Escape from this highly stable
resonance is made possible by the momentum imparted by large basin-forming
impact events, and capture into the 3/2 resonance occurs subsequently under
favourable conditions.",1112.2384v1
2011-12-12,Dynamic quantum Kerr effect in circuit quantum electrodynamics,"A superconducting qubit coupled to a microwave resonator provides a
controllable system that enables fundamental studies of light-matter
interactions. In the dispersive regime, photons in the resonator exhibit
induced frequency and phase shifts which are revealed in the resonator
transmission spectrum measured with fixed qubit-resonator detuning. In this
static detuning scheme, the phase shift is measured in the far-detuned, linear
dispersion regime to avoid measurement-induced demolition of the qubit quantum
state. Here we explore the qubit-resonator dispersive interaction over a much
broader range of detunings, by using a dynamic procedure where the qubit
transition is driven adiabatically. We use resonator Wigner tomography to
monitor the interaction, revealing exotic non-linear effects on different
photon states, e.g., Fock states, coherent states, and Schrodinger cat states,
thereby demonstrating a quantum Kerr effect in the dynamic framework.",1112.2458v1
2011-12-13,On the strong influence of inner shell resonances upon the outer shell photoionization of endohedral atoms,"It is demonstrated by the example of the Xe atom stuffed inside the C60
fullerene, that the so-called confinement resonances in 4d subshell strongly
affect the photoionization cross-section of outer 5p and subvalent 5s electrons
near 4d ionization threshold. It is a surprise that these narrow inner 4d shell
resonances are not smeared out in the outer shell photoionization
cross-section. On the contrary; the inner shell resonances affect the outer
cross-section by enhancing them enormously. Close to its own photoionization
thresholds, 5p and 5s photoionization cross-sections of Xe endohedral are
dominated by their own confinement resonances greatly affected by the
amplification of the incoming radiation intensity due to polarization by it of
the C60 electron shell. In between 4d and 5p thresholds, the effect of 4d is
becoming stronger while own resonances of 5p and 5s are becoming much less
important.",1112.2834v1
2011-12-14,Resonant Matter Wave Amplification in Mean Field Theory,"We develop a Green's function based mean-field theory for coherent mixing of
matter- and light-waves. To demonstrate the utility of this approach, we
analyse a co-propagating Raman matter-wave amplifier. We find that for a given
laser intensity, a significantly faster amplification process can be achieved
employing resonant rather than off-resonance driving. The ratio of the
matter-wave gain to atom loss-rate due to spontaneous emission is given by the
optical depth of the sample, and is the same both on- and off-resonance.
Furthermore, we show that for short-times, the single-mode approximation for
the matter-waves gives exact agreement with the full spatial dynamics. For long
times, the off-resonant case shows suppressed amplification due to a spatially
inhomogenous AC Stark shift associated with laser depletion. This suppression
is absent on-resonance, where the AC Stark shift is absent.",1112.3325v1
2012-02-03,Asymptotics of the resonances for a continuously stratified layer,"Ultrasound wave propagation in a nonhomogeneous linearly elastic layer of
constant thickness is considered. The resonances for the corresponding acoustic
propagator are studied. It is shown that the distribution of the resonances
depends on the smoothness of the coefficients. Namely, if the coefficients have
jump discontinuities at the boundaries, then the resonances are asymptotically
distributed along a straight line parallel to the real axis on the unphysical
sheet of the complex frequency plane. In the contrary, if the coefficients are
continuous, then it is shown that the resonances are asymptotically distributed
along a logarithmic curve.
  The spacing between two successive resonances turns out to be sensitive to
articular cartilage degeneration. The application of the obtained results to
ultrasound testing of articular cartilage is discussed.",1202.0665v1
2012-02-10,Charmed and strange baryon resonances with heavy-quark spin symmetry,"We study charmed and strange baryon resonances that are generated dynamically
by a unitary baryon-meson coupled-channel model which incorporates heavy-quark
spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa
chiral Lagrangian to SU(8) spin-flavor symmetry plus a suitable symmetry
breaking. The model produces resonances with negative parity from s-wave
interaction of pseudoscalar and vector mesons with $1/2^+$ and $3/2^+$ baryons.
Resonances in all the isospin, spin, and strange sectors with one, two, and
three charm units are studied. Our results are compared with experimental data
from several facilities, such as the CLEO, Belle or BaBar Collaborations, as
well as with other theoretical models. Some of our dynamically generated states
can be readily assigned to resonances found experimentally, while others do not
have a straightforward identification and require the compilation of more data
and also a refinement of the model. In particular, we identify the
$\Xi_c(2790)$ and $\Xi_c(2815)$ resonances as possible candidates for a
heavy-quark spin symmetry doublet.",1202.2239v2
2012-02-14,Quantum resonant effects in the delta-kicked rotor revisited,"We review the theoretical model and experimental realization of the atom
optics $\delta-$kicked rotor (AOKR), a paradigm of classical and quantum chaos.
We have performed a number of experiments with an all-optical Bose-Einstein
condensate (BEC) in a periodic standing wave potential in an AOKR system. We
discuss results of the investigation of the phenomena of quantum resonances in
the AOKR. An interesting feature of the momentum distribution of the atoms
obtained as a result of short pulses of light, is the variance of the momentum
distribution or the kinetic energy $<p^{2}>/2m$ in units of the recoil energy
$E_{rec} = \hbar \omega_{rec}$. The energy of the system is examined as a
function of pulse period for a range of kicks that allow the observation of
quantum resonances. In particular we study the behavior of these resonances for
a large number of kicks. Higher order quantum resonant effects corresponding to
the fractional Talbot time of (1/4)$T_{T}$ and (1/5)$T_{T}$ for five and ten
kicks have been observed. Moreover, we describe the effect of the initial
momentum of the atoms on quantum resonances in the AOKR.",1202.3166v1
2012-02-15,Networks of nonlinear superconducting transmission line resonators,"We investigate a network of coupled superconducting transmission line
resonators, each of them made nonlinear with a capacitively shunted Josephson
junction coupling to the odd flux modes of the resonator. The resulting
eigenmode spectrum shows anticrossings between the plasma mode of the shunted
junction and the odd resonator modes. Notably, we find that the combined device
can inherit the complete nonlinearity of the junction, allowing for a
description as a harmonic oscillator with a Kerr nonlinearity. Using a dc SQUID
instead of a single junction, the nonlinearity can be tuned between 10 kHz and
4 MHz while maintaining resonance frequencies of a few gigahertz for realistic
device parameters. An array of such nonlinear resonators can be considered a
scalable superconducting quantum simulator for a Bose-Hubbard Hamiltonian. The
device would be capable of accessing the strongly correlated regime and be
particularly well suited for investigating quantum many-body dynamics of
interacting particles under the influence of drive and dissipation.",1202.3240v2
2012-02-28,Superconducting coplanar waveguide resonators for low temperature pulsed electron spin resonance spectroscopy,"We discuss the design and implementation of thin film superconducting
coplanar waveguide micro- resonators for pulsed ESR experiments. The
performance of the resonators with P doped Si epilayer samples is compared to
waveguide resonators under equivalent conditions. The high achievable filling
factor even for small sized samples and the relatively high Q-factor result in
a sensitivity that is superior to that of conventional waveguide resonators, in
particular to spins close to the sample surface. The peak microwave power is on
the order of a few microwatts, which is compatible with measurements at ultra
low temperatures. We also discuss the effect of the nonuniform microwave
magnetic field on the Hahn echo power dependence.",1202.6305v1
2012-06-06,Electrical Control of Plasmon Resonance with Graphene,"Surface plasmon, with its unique capability to concentrate light into
sub-wavelength volume, has enabled great advances in photon science, ranging
from nano-antenna and single-molecule Raman scattering to plasmonic waveguide
and metamaterials. In many applications it is desirable to control the surface
plasmon resonance in situ with electric field. Graphene, with its unique
tunable optical properties, provides an ideal material to integrate with
nanometallic structures for realizing such control. Here we demonstrate
effective modulation of the plasmon resonance in a model system composed of
hybrid graphene-gold nanorod structure. Upon electrical gating the strong
optical transitions in graphene can be switched on and off, which leads to
significant modulation of both the resonance frequency and quality factor of
plasmon resonance in gold nanorods. Hybrid graphene-nanometallic structures, as
exemplified by this combination of graphene and gold nanorod, provide a general
and powerful way for electrical control of plasmon resonances. It holds promise
for novel active optical devices and plasmonic circuits at the deep
subwavelength scale.",1206.1124v1
2012-06-11,Resonant Signatures of Heavy Scalar Fields in the Cosmic Microwave Background,"We investigate the possibility that a heavy scalar field, whose mass exceeds
the Hubble scale during inflation, could leave non-negligible signatures in the
Cosmic Microwave Background (CMB) temperature anisotropy power spectrum through
the parametric resonance between its background oscillations and the inflaton
fluctuations. By assuming the heavy scalar field couples with the inflaton
derivatively, we show that the resonance can be efficient without spoiling the
slow-roll inflation. The primordial power spectrum modulated by the resonance
has a sharp peak at a specific scale and could be an origin of the anomalies
observed in the angular power spectrum of the CMB. In some values of
parameters, the modulated spectrum can fit the observed data better than the
simple power-law power spectrum, though the resultant improvement of the fit is
not large enough and hence other observations such as non-Gaussianity are
necessary to confirm that the CMB anomalies are originated from the resonant
effect of the heavy scalar field. The resonant signatures can provide an
opportunity to observe heavy degrees of freedom during inflation and improve
our understanding of physics behind inflation.",1206.2164v1
2012-06-13,Modulation of a surface plasmon-polariton resonance by sub-terahertz diffracted coherent phonons,"Coherent sub-THz phonons incident on a gold grating that is deposited on a
dielectric substrate undergo diffraction and thereby induce an alteration of
the surface plasmon-polariton resonance. This results in efficient
high-frequency modulation (up to 110 GHz) of the structure's reflectivity for
visible light in the vicinity of the plasmon-polariton resonance. High
modulation efficiency is achieved by designing a periodic nanostructure which
provides both plasmon-polariton and phonon resonances. Our theoretical analysis
shows that the dynamical alteration of the plasmon-polariton resonance is
governed by modulation of the slit widths within the grating at the frequencies
of higher-order phonon resonances.",1206.2771v2
2012-07-17,Lévy Noise-Induced Stochastic Resonance in a Bistable System,"Stochastic resonance phenomenon induced by non-Gaussian L\'evy noise in a
second-order bistable system is investigated. The signal-noise-ratio for
different parameters is computed by an efficient numerical scheme. The
influences of the noise intensity, stability index of L\'evy noise and
amplitude of external signal on the occurrence of stochastic resonance
phenomenon are characterized. This implies that a high amplitude of signal not
only enhances the output power spectrum of system but also promotes stochastic
resonance, and a proper adjustment of L\'evy noise intensity in a certain range
enlarges the peak value of output power spectrum which is significant for
stochastic resonance. Moreover, with the optimal damping parameter, lowering
the stability index leads to larger fluctuations of L\'evy noise, and further
reduces the chance of the stochastic resonance.",1207.3939v1
2012-07-25,Nonlinear eigenvalue problem for optimal resonances in optical cavities,"The paper is devoted to optimization of resonances in a 1-D open optical
cavity. The cavity's structure is represented by its dielectric permittivity
function e(s). It is assumed that e(s) takes values in the range 1 <= e_1 <=
e(s) <= e_2. The problem is to design, for a given (real) frequency, a cavity
having a resonance with the minimal possible decay rate. Restricting ourselves
to resonances of a given frequency, we define cavities and resonant modes with
locally extremal decay rate, and then study their properties. We show that such
locally extremal cavities are 1-D photonic crystals consisting of alternating
layers of two materials with extreme allowed dielectric permittivities e_1 and
e_2. To find thicknesses of these layers, a nonlinear eigenvalue problem for
locally extremal resonant modes is derived. It occurs that coordinates of
interface planes between the layers can be expressed via arg-function of
corresponding modes. As a result, the question of minimization of the decay
rate is reduced to a four-dimensional problem of finding the zeroes of a
function of two variables.",1207.6073v1
2012-09-19,The roles of nucleon resonances in $Λ$(1520) photoproduciton off proton,"In this work the roles of the nucleon resonances in the $\Lambda$(1520)
photoproduction off proton target are investigated within the effective
Lagrangian method. Besides the Born terms,including contact term, $s$-, $u$-
and $K$ exchanged $t$-channels, vector meson $K^*$ exchanged $t-$channel is
considered in our investigation, which is negligible at low energy and
important at high energy. The important nucleon resonances predicted by the
constituent quark model (CQM) are considered and the results are found well
comparable with the experimental data. Besides the dominant $D_{13}(2080)$, the
resonance $[\textstyle{5\over 2}^-]_2(2080)$ predicted by the CQM is found
important to reproduce the experimental data. Other nucleon resonances are
found to give small contributions in the channel considered in this work. With
all important nucleon resonances predicted by CQM, the prediction of the
differential cross section at the energy up to 5.5 GeV are presented also,
which can be checked by the future CLAS experimental data.",1209.4138v1
2012-10-01,Interplay between the 0+_2 resonance and the nonresonant continuum of the drip-line two-neutron halo nucleus 22C,"The breakup cross section (BUX) of 22C by 12C at 250 MeV/nucleon is evaluated
by the continuum-discretized coupled-channels method incorporating the
cluster-orbital shell model (COSM) wave functions. Contributions of the
low-lying 0+_2 and 2+_1 resonances predicted by COSM to the BUX are
investigated. The 2+_1 resonance gives a narrow peak in the BUX, as in usual
resonant reactions, whereas the 0+_2 resonant cross section has a peculiar
shape due to the coupling to the nonresonant continuum, i.e., the Fano effect.
By changing the scattering angle of 22C after the breakup, a variety of shapes
of the 0+_2 resonant cross sections is obtained. Mechanism of the appearance of
the sizable Fano effect in the breakup of 22C is discussed.",1210.0277v1
2012-10-05,Phase distortions of attosecond pulses produced by resonance-enhanced high harmonic generation,"Resonant enhancement of high harmonic generation can be obtained in plasmas
containing ions with strong radiative transitions resonant with harmonic
orders. The mechanism for this enhancement is still debated. We perform the
first temporal characterization of the attosecond emission from a tin plasma
under near-resonant conditions for two different resonance detunings. We show
that the resonance considerably changes the relative phase of neighbouring
harmonics. For very small detunings, their phase locking may even be lost,
evidencing strong phase distortions in the emission process and a modified
attosecond structure. These features are well reproduced by our simulations,
allowing their interpretation in terms of the phase of the recombination dipole
moment.",1210.1720v1
2012-10-17,Odd parity bottom-flavored baryon resonances,"The LHCb Collaboration has recently observed two narrow baryon resonances
with beauty. Their masses and decay modes look consistent with the quark model
orbitally excited states Lambda_b(5912) and Lambda*_b(5920), with quantum
numbers J^P=1/2^- and 3/2^-, respectively. We predict the existence of these
states within a unitarized meson-baryon coupled-channel dynamical model, which
implements heavy-quark spin symmetry. Masses, quantum numbers and couplings of
these resonances to the different meson-baryon channels are obtained. We find
that the resonances Lambda^0_b(5912) and Lambda^0_b(5920) are heavy-quark spin
symmetry partners, which naturally explains their approximate mass degeneracy.
Corresponding bottom-strange baryon resonances are predicted at Xi_b(6035.4)
(J^P=1/2^-) and Xi_b(6043.3) (J^P=3/2^-). The two Lambda_b and two Xi_b
resonances complete a multiplet of SU(3)-flavor times heavy-quark spin
symmetry.",1210.4755v3
2012-11-01,Resonant non-Gaussianity with equilateral properties,"We discuss the effect of superimposing multiple sources of resonant
non-Gaussianity, which arise for instance in models of axion inflation. The
resulting sum of oscillating shape contributions can be used to ""Fourier
synthesize"" different non-oscillating shapes in the bispectrum. As an example
we reproduce an approximately equilateral shape from the superposition of
${\cal O}(10)$ oscillatory contributions with resonant shape. This implies a
possible degeneracy between the equilateral-type non-Gaussianity typical of
models with non-canonical kinetic terms, such as DBI inflation, and an
equilateral-type shape arising from a superposition of resonant-type
contributions in theories with canonical kinetic terms. The absence of
oscillations in the 2-point function together with the structure of the
resonant $N$-point functions, imply that detection of equilateral
non-Gaussianity at a level greater than the PLANCK sensitivity of
$f_{NL}\sim{\cal O}(5)$ will rule out a resonant origin. We comment on the
questions arising from possible embeddings of this idea in a string theory
setting.",1211.0070v2
2012-11-01,Strange hadron and resonance production in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV with ALICE experiment at LHC,"The ALICE experiment at the LHC has measured the production of strange
hadrons and resonances in Pb-Pb and pp collisions at unprecedented high beam
energies. The study of strange hadrons and resonances helps us to understand
the properties of the medium created in the heavy-ion collisions and its
evolution. We present the yields ($dN/dy$) at mid-rapidity for strange hadrons
($\Lambda$, $\Xi^{-}$, $\Omega^{-}$, their anti-particles and $K_{S}^{0}$) and
resonances ($\phi$ and $K^{*0}$) for several collision centrality intervals.
The results from Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV are presented
and compared to corresponding results from pp collisions and lower energy
measurements. Baryon to meson ratios and resonance to non-resonance particle
ratios relative to pp collisions are shown as a function of collision
centrality and compared with the results at lower energies.",1211.0187v1
2012-11-09,Observation of interspecies Li-Cs Feshbach resonances,"We report on the observation of nineteen interspecies Feshbach resonances in
an optically trapped ultracold Bose-Fermi mixture of ^{133}Cs and ^{6}Li in the
two energetically lowest spin states. We assign the resonances to s- and p-wave
molecular channels by a coupled-channels calculation, resulting in an accurate
determination of LiCs ground state potentials. Fits of the resonance position
based on the undressed Asymptotic Bound State model do not provide the same
level of accuracy as the coupled-channels calculation. Several broad s-wave
resonances provide prospects to create fermionic LiCs molecules with a large
dipole moment via Feshbach association followed by stimulated Raman passage.
Two of the s-wave resonances overlap with a zero crossing of the Cs scattering
length which offers prospects for the investigation of polarons in an ultracold
Li-Cs mixture.",1211.2139v2
2012-11-10,Resonant polaron-assisted tunneling of strongly interacting electrons through a single-level vibrating quantum dot,"The problem of resonant transport of strongly interacting electrons through a
one-dimensional single-level vibrating quantum dot is being considered. In this
paper, we generalize the Komnik and Gogolin model [Phys. Rev. Lett., 90,
246403, (2003)] for the single-electron transistor with g=1/2 Luttinger liquid
leads to the case of a strong electron-vibron interaction in a quantum dot. The
effective transmission coefficient and differential conductance of the system
has been derived for the general case of asymmetric tunnel barriers. The main
result obtained is that, in the zero-temperature limit, the resonant
polaron-assisted tunneling with perfect transmission is possible. This resonant
tunneling is of the novel (Andreev-like) type due to a special
electron-electron interaction in the leads. As a result, a strong domination of
resonant polaron-assisted electron transport at low temperatures has been
found. Additional narrowing due to electron-electron interaction in the leads,
is roughly the same for all polaron-assisted resonances.",1211.2351v1
2012-11-15,Spin-2 Resonances in Vector-Boson-Fusion Processes at NLO QCD,"The most likely spin assignments of the recently discovered 126 GeV resonance
are spin 0 or 2. In order to distinguish the two, we construct an effective
Lagrangian model which comprises interactions of a spin-2 electroweak singlet
or triplet state with the SM gauge bosons. Within this model, cross sections
and differential distributions are calculated and implemented within the Monte
Carlo program VBFNLO, which simulates vector-boson-fusion processes at hadron
colliders at NLO QCD accuracy. We study the phenomenology of spin-2 resonances
produced in vector-boson-fusion processes at the LHC. Specifically, we consider
light Higgs-like spin-2 resonances decaying into two photons and show how
angular distributions allow us to distinguish between a Standard Model Higgs
and a spin-2 resonance. We also investigate the characteristics of heavy spin-2
resonances which decay into two weak gauge bosons, leading to a four-lepton
final state.",1211.3658v2
2012-11-22,Search for Resonant Top-antitop Production in the Semi-leptonic Decay Mode Using the Full CDF Data Set,"This Letter reports a search for a narrow resonant state decaying into two
$W$ bosons and a bottom-antibottom quark pair where one $W$ boson decays
leptonically and the other decays into a quark-antiquark pair. The search is
particularly sensitive to top-antitop resonant production. We use the full data
sample of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV
collected by the CDF II detector at the Fermilab Tevatron, corresponding to an
integrated luminosity of 9.45 fb$^{-1}$. No evidence for resonant production is
found and upper limits on the production cross section times branching ratio
for a narrow resonant state are extracted. Within a specific benchmark model,
we exclude a $Z'$ boson with mass below 915 GeV/$c^2$ decaying into a
top-antitop pair at the 95% credibility level assuming a $Z'$ boson decay width
of $\Gamma_{Z'} = 0.012 M_{Z'}$. This is the most sensitive search for a narrow
$\ensuremath{q\bar{q}}$-initiated $\ensuremath{t\bar{t}}$ resonance in the mass
region below 750 GeV/$c^2$.",1211.5363v1
2012-11-29,Resonant states of deformed nuclei in complex scaling method,"We develop a complex scaling method for describing the resonances of deformed
nuclei and present a theoretical formalism for the bound and resonant states on
the same footing. With $^{31}$Ne as an illustrated example, we have
demonstrated the utility and applicability of the extended method and have
calculated the energies and widths of low-lying neutron resonances in
$^{31}$Ne. The bound and resonant levels in the deformed potential are in full
agreement with those from the multichannel scattering approach. The width of
the two lowest-lying resonant states shows a novel evolution with deformation
and supports an explanation of the deformed halo for $^{31}$Ne.",1211.6920v1
2012-12-21,Feshbach resonances in ultracold 85Rb,"We present 17 experimentally confirmed Feshbach resonances in optically
trapped 85Rb. Seven of the resonances are in the ground-state channel (f,m_f) =
(2,+2)+(2,+2), and nine are in the excited-state channel (2,-2)+(2,-2). We find
a wide resonance at high field in each of the two channels, offering new
possibilities for the formation of larger 85Rb condensates and studies of
few-body physics. A detailed coupled-channels analysis is presented to
characterize the resonances, and also provides an understanding of the
inelastic losses observed in the excited-state channel. In addition we have
confirmed the existence of one narrow resonance in a (2,+2)+(3,+3) spin
mixture.",1212.5446v1
2013-01-14,Analyses on a Relativistic Hierarchical Resonance with the Hamiltonian Approach,"We study dynamical evolution of a resonant triple system formed by an inner
EMRI and an additional outer MBH. The relevant resonant state
(\lambda_2-\varpi_1 ~ const) is supported by the relativistic apsidal
precession of the inner EMRI, and, unlike standard mean motion resonances, the
triple system can have a hierarchical orbital configuration (but different from
the Kozai process). In order to analyze this unusual resonant system, we extend
the so-called Hamiltonian approach, and derive a mapping from the EMRI-MBH
triple system to a simple one-dimensional Hamiltonian. With the derived
mapping, we make analytical predictions for characteristic quantities of the
resonance, such as the capture probability, and find that they reasonably agree
with numerical simulations up to moderate eccentricities.",1301.3135v1
2013-02-18,A Dynamical Cross-over Regime in the Transmission and Reflection Spectra of Evanescent Waves with 2D Arrays of Josephson Junctions,"A dynamical cross-over regime is revealed when exposing a classical
two-dimensional ordered Josephson junction (JJ) array to evanescent waves and
tuning the incident microwave power. At the lowest possible temperature for
these experiments, 1.1 K, and at the lowest power setting, -55 dBm, evanescent
waves are transmitted without loss and the resonance exhibits a quality factor
of ~ 4200. A second, smaller resonance, which evolves with increasing power
from the main resonance, is also investigated. In contrast to the behavior of
the main resonance, this second peak grows as the incident power is increased
and does not maintain a fixed resonant frequency for temperatures less than the
superconducting critical temperature of niobium. The tunability of both
resonances is studied as a function of temperature and microwave power. Finally
we speculate that this dynamical crossover regime is evidence of a transition
between two states of phase coherence where at low microwave power the JJ
arrays are phase locked and at high microwave power the JJ arrays are unlocked.",1302.4364v1
2013-02-25,Squeezing of light via reflection from a silicon micromechanical resonator,"We present the measurement of squeezed light generation using an engineered
optomechanical system fabricated from a silicon microchip and composed of a
micromechanical resonator coupled to a nanophotonic cavity. Laser light is used
to measure the fluctuations in the position of the mechanical resonator at a
measurement rate comparable to the free dynamics of the mechanical resonator,
and greater than its thermal decoherence rate. By approaching the strong
continuous measurement regime we observe, through homodyne detection,
non-trivial modifications of the reflected light's vacuum fluctuation spectrum.
In spite of the mechanical resonator's highly excited thermal state ($10,000$
phonons), we observe squeezing at the level of $4.5 \pm 0.5%$ below that of
shot-noise over a few MHz bandwidth around the mechanical resonance frequency
of 28 MHz. This squeezing is interpreted as an unambiguous quantum signature of
radiation pressure shot-noise.",1302.6179v2
2013-03-15,Broadband second harmonic generation in whispering gallery mode resonators,"Optical frequency conversion processes in nonlinear materials are limited in
wavelength by the accessible phase matching and the required high pump powers.
In this letter, we report a novel broadband phase matching (PM) technique in
high quality factor (Q) whispering gallery mode (WGM) resonators made of
birefringent crystalline materials. This technique relies on two interacting
WGMs, one with constant and the other with spatially oscillating phase
velocity. Thus, phase matching occurs cyclically. The technique can be
implemented with a WGM resonator with its disk plane parallel to the optic axis
of the crystal. With a single beta barium borate (BBO) resonator in that
configuration, we experimentally demonstrated efficient second harmonic
generation (SHG) to harmonic wavelengths from 780 nm in the near infrared to
317 nm in the ultraviolet (UV). The observed SHG conversion efficiency is as
high as 4.6% (mW)-1. This broadband PM technique opens a new way for nonlinear
optics applications in WGM resonators. This work is also the first reported
continuous wave UV generation by direct SHG in a WGM resonator",1303.3814v1
2013-03-19,Universal Two-body Physics in Dark Matter near an S-wave Resonance,"The dark matter annihilation rate at small relative velocities can be
amplified by a large boost factor using various mechanisms, including
Sommerfeld enhancement, resonance enhancement, and Breit-Wigner enhancement.
These mechanisms all involve a resonance near the threshold for a pair of dark
matter particles. We point out that if the resonance is in the S-wave channel,
the mechanisms are equivalent sufficiently near the resonance and they are
constrained by universal two-body physics. The amplified annihilation rate
requires a corresponding amplification of the elastic scattering cross section.
If the resonance is a bound state below the threshold, it has an increased
lifetime that is inversely proportional to the square root of the binding
energy. Its spatial structure is that of two dark matter particles whose mean
separation is also inversely proportional to the square root of the binding
energy.",1303.4682v2
2013-04-24,Magnonlike dispersion of spin resonance in Ni-doped BaFe$_2$As$_2$,"Inelastic neutron scattering measurements on
Ba(Fe$_{0.963}$Ni$_{0.037}$)$_2$As$_2$ manifest a neutron spin resonance in the
superconducting state with anisotropic dispersion within the Fe layer. Whereas
the resonance is sharply peaked at Q$_{AFM}$ along the orthorhombic a axis, the
resonance disperses upwards away from Q$_{AFM}$ along the b axis. In contrast
to the downward dispersing resonance and hour-glass shape of the spin
excitations in superconducting cuprates, the resonance in electron-doped
BaFe$_2$As$_2$ compounds possesses a magnon-like upwards dispersion.",1304.6657v1
2013-05-08,Surface plasmon-polariton resonance at diffraction of THz radiation on semiconductor gratings,"Resonance diffraction of THz HCN laser radiation on a semiconductor (InSb)
grating is studied both experimentally and theoretically. The specular
reflectivity suppression due to the resonance excitation of the THz surface
plasmon-polariton is observed on a pure semiconductor grating and on
semiconductor gratings covered with a thin striped layer of the residual
photoresist. Presence of a thin dielectric layer on the grating surface leads
to the shift and widening of the plasmon-polariton resonance. A simple
analytical theory of the resonance diffraction on a shallow grating covered
with a dielectric layer is presented. Its results are in a good accordance with
the experimental data. Analytical expressions for the resonance shift and
broadening can be useful for sensing data interpretation.",1305.1785v1
2013-05-09,Structure of Near-Threshold s-Wave Resonances,"We study the structure of two-body s-wave bound states as well as resonances
in the threshold energy region. We focus on the single-channel scattering where
the scattering length and the effective range are given by real numbers. It is
shown that, in the energy region where the effective range expansion is valid,
the properties of resonances are constrained only by the position of the pole.
We find that the compositeness defined through the analytic continuation of the
field renormalization constant is pure imaginary and normalized for resonances.
We discuss the interpretation of this quantity by examining the structure of
the hadron resonance Lambda_c(2595) in the pi Sigma_c scattering. We show that
the Lambda_c(2595) resonance requires an unnaturally large effective range and
hence it is not likely a pi Sigma_c molecule.",1305.1999v4
2013-05-24,Fano resonance in Raman scattering of graphene,"Fano resonances and their strong doping dependence are observed in Raman
scattering of single-layer graphene (SLG). As the Fermi level is varied by a
back-gate bias, the Raman G band of SLG exhibits an asymmetric line shape near
the charge neutrality point as a manifestation of a Fano resonance, whereas the
line shape is symmetric when the graphene sample is electron or hole doped.
However, the G band of bilayer graphene (BLG) does not exhibit any Fano
resonance regardless of doping. The observed Fano resonance can be interpreted
as interferences between the phonon and excitonic many-body spectra in SLG. The
absence of a Fano resonance in the Raman G band of BLG can be explained in the
same framework since excitonic interactions are not expected in BLG.",1305.5589v1
2013-06-01,Feshbach Resonance in a Tight-Binding Model,"The physics of Feshbach resonance is analyzed using an analytic expression
for the $s$-wave scattering phase-shift and the scattering length $a$ which we
derive within a two-channel tight-binding model. Employing a unified treatment
of bound states and resonances in terms of the Jost function, it is shown that
for strong inter-channel coupling, Feshbach resonance can occur even when the
closed channel does not have a bound state. This may extend the range of
ultra-cold atomic systems that can be manipulated by Feshbach resonance. The
dependence of the sign of $a$ on the coupling strength in the unitary limit is
elucidated. As a by-product, analytic expressions are derived for the
background scattering length, the external magnetic field at which resonance
occurs, and the energy shift $\varepsilon-\varepsilon_B$, where $\varepsilon$
is the scattering energy and $\varepsilon_B$ is the bound state energy in the
closed channel (when there is one).",1306.0144v4
2013-06-03,Optical control of a magnetic Feshbach resonance in ultracold Fermi gases,"We use laser light near-resonant with a molecular bound-to-bound transition
to control a magnetic Feshbach resonance in ultracold Fermi gases of $^{40}$K
atoms. The spectrum of excited molecular states is measured by applying a laser
field that couples the ground Feshbach molecular state to electronically
excited molecular states. Nine strong bound-to-bound resonances are observed
below the $^{2}P_{1/2}+^{2}S_{1/2}$ threshold. We use radio-frequency
spectroscopy to characterize the laser-dressed bound state near a specific
bound-to-bound resonance and show clearly the shift of the magnetic Feshbach
resonance using light with negligible atomic loss. The demonstrated technology
could be used to modify interatomic interactions with high spatial and temporal
resolutions in the crossover regime from a Bose-Einstein condensate (BEC) to a
Bardeen-Cooper-Schrieffer (BCS) superfluid.",1306.0395v3
2013-06-25,Phonon Cooling and Lasing with Nitrogen-Vacancy Centers in Diamond,"We investigate the strain-induced coupling between a nitrogen-vacancy
impurity and a resonant vibrational mode of a diamond nanoresonator. We show
that under near-resonant laser excitation of the electronic states of the
impurity, this coupling can modify the state of the resonator and either cool
the resonator close to the vibrational ground state or drive it into a large
amplitude coherent state. We derive a semi-classical model to describe both
effects and evaluate the stationary state of the resonator mode under various
driving conditions. In particular, we find that by exploiting resonant single
and multi-phonon transitions between near-degenerate electronic states, the
coupling to high-frequency vibrational modes can be significantly enhanced and
dominate over the intrinsic mechanical dissipation. Our results show that a
single nitrogen-vacancy impurity can provide a versatile tool to manipulate and
probe individual phonon modes in nanoscale diamond structures.",1306.5915v3
2013-07-09,Integrated optics Bragg grating ring resonators with Q-factor on gigascale,"In this paper we propose a new optical ring resonator with a very high
Q-factor, to be used as a basic element in a wide range of physics and
engineering applications. We theoretically demonstrate that in large size
conventional ring resonators, a value of the Q-factor higher than 109 is
achievable by exploiting the band-edge resonances in a waveguiding long period
Bragg grating closed loop, excited through a bus waveguide. The dispersion
introduced by the Bragg grating is responsible for a reduction in the band edge
resonance linewidth, which is inversely proportional to the square of the
number of periods of the grating, thus allowing the overall Q-factor to be
enhanced. Numerical results show a substantial improvement in the Q-factor,
giving a number of order of magnitude higher than that of a conventional large
size ring resonator.",1307.2413v2
2013-07-19,High-order harmonic generation and Fano resonances,"We present a high harmonic generation theory which generalizes the
strong-field approximation to the resonant case, when the harmonic frequency is
close to that of the transition from the ground to an autoionizing state of the
generating system. We show that the line shape of the resonant harmonic is a
product of the Fano-like factor and the harmonic line which would be emitted in
the absence of the resonance. The theory predicts rapid variation of the
harmonic phase in the vicinity of the resonance. The calculated resonant
harmonic phase is in reasonable agreement with recent measurements. Predicting
the phase-locking of a group of resonantly-enhanced harmonics, our theory
allows to study the perspectives of producing attosecond pulse train using such
harmonics.",1307.5241v1
2013-07-23,Resonator Power to Frequency Conversion in a Cryogenic Sapphire Oscillator,"We report on the measurement and characterization of power to frequency
conversion in the resonant mode of a cryogenic sapphire loaded cavity
resonator, which is used as the frequency discriminating element of a loop
oscillator circuit. Fluctuations of power incident on the resonator leads to
changes in radiation pressure and temperature in the sapphire dielectric, both
of which contribute to a shift in the resonance frequency. We measure a
modulation and temperature independent radiation pressure induced power to
frequency sensitivity of -0.15 Hz/mW and find that this is the primary factor
limiting the stability of the resonator frequency.",1307.6078v1
2013-07-29,Symmetry Energy Constraints from Giant Resonances: A Theoretical Overview,"Giant resonances encapsulate the dynamic response of the nuclear ground state
to external perturbations. As such, they offer a unique view of the nucleus
that is often not accessible otherwise. Although interesting in their own
right, giant resonances are also enormously valuable in providing stringent
constraints on the equation of state of asymmetric matter. We this view in
mind, we focus on two modes of excitation that are essential in reaching this
goal: the isoscalar giant monopole resonance (GMR) and the isovector giant
dipole resonance (GDR). GMR energies in heavy nuclei are sensitive to the
symmetry energy because they probe the incompressibility of neutron-rich
matter. Unfortunately, access to the symmetry energy is hindered by the
relatively low neutron-proton asymmetry of stable nuclei. Thus, the measurement
of GMR energies in exotic nuclei is strongly encouraged. In the case of the
GDR, we find the electric dipole polarizability of paramount importance.
Indeed, the electric dipole polarizability appears as one of two laboratory
observables -- with the neutron-skin thickness being the other -- that are
highly sensitive to the density dependence of the symmetry energy. Finally, we
identify the softness of skin and the nature of the pygmy resonance as
important unsolved problems in nuclear structure.",1307.7746v1
2013-10-04,Aharonov-Bohm phase-driven resonant tunneling of interacting electrons in magnetopolaronic Majorana-Resonant-Level Model,"The magnetopolaronic generalization of a Majorana-resonant-level (-MRL) model
is considered for a single-level vibrating quantum dot symmetrically coupled to
two half-infinite $g=1/2$- Tomonaga-Luttinger liquid (-TLL) leads at the
Toulouse point. At the resonance by gate voltage the exact solution for the
effective transmission coefficient is obtained in the whole range of
magnetopolaronic coupling constant values. The obtained exact solution exists
due to special Majorana-like symmetry of tunnel Hamiltonian and gives rise to
nontrivial interference between different virtual vibronic channels of resonant
tunneling with different fixed Aharonov-Bohm phases. This fact leads to a novel
topologically nontrivial type of resonant Andreev-like magnetopolaronic
tunneling in the system. As the result, in the zero-temperature limit, it is
impossible to compensate the magnetopolaronic blockade in magnetopolaronic
MRL-model by means of bias voltage, if vibron energy is the smallest (but
nonzero) energy parameter in the system.",1310.1326v1
2013-10-07,Double magnetic resonance and spin anisotropy in Fe-based superconductors due to static and fluctuating antiferromagnetic orders,"Motivated by recent neutron scattering experiments in Fe-based
superconductors, we study how the magnetic resonance in the superconducting
state is affected by the simultaneous presence of either static or fluctuating
magnetic orders using the random phase approximation. We find that for the
underdoped materials with coexisting superconducting and antiferromagnetic
orders, spin rotational symmetry is explicitly broken at the ordering momentum
$Q_1 = (\pi,0)$. Only the longitudinal susceptibility exhibits the resonance
mode, whereas a spin-wave Goldstone mode develops in the transverse component.
Meanwhile, at the frustrated momentum $Q_2 = (0,\pi)$, the susceptibility
becomes isotropic in spin space and the magnetic resonance exists for both
components. Furthermore, the resonance energies at $Q_1$ and $Q_2$ have
distinct scales, which provides a natural explanation for the recently observed
double resonance peaks. In addition, we show that near optimal doping the
existence of strong magnetic fluctuations, which are modeled here via a
Gaussian mode, can still induce the spin anisotropy in the magnetic
susceptibility.",1310.1657v2
2013-10-10,Revisiting the physics of Fano resonances for nanoparticle oligomers,"We present a new and robust approach for interpreting the physics of Fano
resonances in planar oligomer structures of both metallic and dielectric
nanoparticles. We reveal a key mechanism for Fano resonances by demonstrating
that such resonances can be generated purely from the interference of
nonorthogonal collective eigenmodes, which are clearly identified based on the
coupled-dipole approximation. We prove analytically a general theorem to
identify the number of collective eigenmodes that can be excited in ring-type
nanoparticle oligomers and further demonstrate that no dark mode excitation is
necessary for existence of Fano resonances in symmetric oligomers. As a
consequence, we unify the understanding of Fano resonances for both plasmonic
and all-dielectric oligomers.",1310.2983v2
2013-10-16,Spectral_Engineering_with_CMOS_compatible_SOI_Photonic_Molecules,"Photonic systems based on microring resonators have a fundamental constrain
given by the strict relationship among free spectral range (FSR), total quality
factor (QT) and resonator size, intrinsically making filter spacing, photonic
lifetime and footprint interdependent. Here we break this paradigm employing
CMOS compatible Silicon-on-Insulator (SOI) photonic molecules based on coupled
multiple ring resonators. The resonance wavelengths and their respective
linewidths are controlled by the hybridization of the quasi-orthogonal photonic
states. We demonstrate photonic molecules with doublet and triplet resonances
with spectral spliting only achievable with single rings orders of magnitude
larger in foot print. Besides, these splitting are potentially controllable
based on the coupling (bonds) between resonators. Finally, the spatial
distribution of the hybrid states allows up to sevenfold QT enhancement.",1310.4370v1
2013-10-21,Implications of the ABC Resonance Structure on Elastic Neutron-Proton Scattering,"In recent WASA-at-COSY measurements of the basic double-pionic fusion
reactions $pn \to d\pi^0\pi^0$ and $pn \to d\pi^+\pi^-$ a narrow resonance
structure with $I(J^P) = 0(3^+)$ in the total cross section has been found. If
this constitutes a s-channel resonance in the $pn$ system, then it should cause
distinctive consequences in $pn$ scattering. The magnitude of the decay width
into the $pn$ channel is estimated and the expected resonance effects in
integral and differential $pn$ scattering observables are presented. The
inclusion of the resonance improves the description of total cross section
data. For the analyzing power a characteristic energy dependence is predicted,
which should allow a crucial experimental check of the resonance hypothesis.",1310.5532v1
2013-10-26,Resonant waves in elastic structured media: dynamic homogenisation versus Green's functions,"We address an important issue of a dynamic homogenisation in vector
elasticity for a doubly periodic mass-spring elastic lattice. The notion of
logarithmically growing resonant waves is used in a complete analysis of
star-shaped wave forms induced by an oscillating point force. We note that the
dispersion surfaces for Floquet-Bloch waves in an elastic lattice main contain
critical points of the saddle type. Based on the local quadratic approximations
of the frequency, as a function of wave vector components, we deduce properties
of a transient asymptotic solution as the contribution of the point source to
the wave form. In this way, we describe local Green's functions as localized
wave forms corresponding to the resonant frequency. The peculiarity of the
problem lies in the fact that, at the same resonant frequency, the Taylor
quadratic approximations for different groups of the resonant points are
different, and hence we deal with different local Green's functions. Thus,
there is no uniformly defined homogenisation procedure for a given resonant
frequency. Instead, the continuous approximation of the wave field can be
obtained through the asymptotic analysis of the lattice Green's functions.",1310.7089v1
2013-10-28,Polarization-rotation resonances with subnatural widths using a control laser,"We demonstrate extremely narrow resonances for polarization rotation in an
atomic vapor. The resonances are created using a strong control laser on the
same transition, which polarizes the atoms due to optical pumping among the
magnetic sublevels. As the power in the control laser is increased,
successively higher-order nested polarization rotation resonances are created,
with progressively narrower linewidths. We study these resonances in the $D_2$
line of Rb in a room-temperature vapor cell, and demonstrate a width of $0.14
\, \Gamma$ for the third-order rotation. The explanation based on a simplified
$\Lambda$V-type level structure is borne out by a density-matrix analysis of
the system. The dispersive lineshape and subnatural width of the resonance
lends itself naturally to applications such as laser locking to atomic
transitions and precision measurements.",1310.7330v2
2013-11-15,Off-resonance energy absorption in a linear Paul trap due to mass selective resonant quenching,"Linear Paul r.f. ion traps (LPT) are used in many experimental studies such
as mass spectrometry, atom-ion collisions and ion-molecule reactions. Mass
selective resonant quenching (MSRQ) is implemented in LPT either to identify a
charged particle's mass or to remove unwanted ions from a controlled
experimental environment. In the latter case, MSRQ can introduce undesired
heating to co-trapped ions of different mass, whose secular motion is off
resonance with the quenching ac field, which we call off-resonance energy
absorption (OREA). We present simulations and experimental evidence that show
that the OREA increases exponentially with the number of ions loaded into the
trap and with the amplitude of the off-resonance external ac field.",1311.3970v1
2013-11-26,Symmetry breaking in a mechanical resonator made from a carbon nanotube,"Nanotubes behave as semi-flexible polymers in that they can bend by a
sizeable amount. When integrating a nanotube in a mechanical resonator, the
bending is expected to break the symmetry of the restoring potential. Here we
report on a new detection method that allows us to demonstrate such symmetry
breaking. The method probes the motion of the nanotube resonator at nearly
zero-frequency; this motion is the low-frequency counterpart of the second
overtone of resonantly excited vibrations. We find that symmetry breaking leads
to the spectral broadening of mechanical resonances, and to an apparent quality
factor that drops below 100 at room temperature. The low quality factor at room
temperature is a striking feature of nanotube resonators whose origin has
remained elusive for many years. Our results shed light on the role played by
symmetry breaking in the mechanics of nanotube resonators.",1311.6589v1
2013-12-01,Probing evolution of binaries influenced by the spin-orbit resonances,"We evolve isolated comparable mass spinning compact binaries experiencing
Schnittman's post-Newtonian spin-orbit resonances in an inertial frame
associated with $j_0$, the initial direction of the total angular momentum. We
argue that accurate gravitational wave (GW) measurements of the initial
orientations of the two spins and orbital angular momentum from $j_0$ should
allow us to distinguish between the two possible families of spin-orbit
resonances. Therefore, these measurements have the potential to provide direct
observational evidence of possible binary formation scenarios. The above
statements should also apply for binaries that do not remain in a resonant
plane when they become detectable by GW interferometers. The resonant plane,
characterized by the vanishing scalar triple product involving the two spins
and the orbital angular momentum, naturally appears in the one parameter family
of equilibrium solutions, discovered by Schnittman. We develop a prescription
to compute the time-domain inspiral templates for binaries residing in these
resonant configurations and explore their preliminary data analysis
consequences.",1312.0217v2
2013-12-11,Non-Linear Resonance in Relativistic Preheating,"Inflation in the early Universe can be followed by a brief period of
preheating, resulting in rapid and non-equilibrium particle production through
the dynamics of parametric resonance. However, the parametric resonance effect
is very sensitive to the linearity of the reheating sector. Additional
self-interactions in the reheating sector, such as non-canonical kinetic terms
like the DBI Lagrangian, may enhance or frustrate the parametric resonance
effect of preheating. In the case of a DBI reheating sector, preheating is
described by parametric resonance of a damped relativistic harmonic oscillator.
In this paper, we illustrate how the non-linear terms in the relativistic
oscillator shut down the parametric resonance effect. This limits the
effectiveness of preheating when there are non-linear self-interactions.",1312.3006v3
2014-01-28,Coherent versus incoherent excitation dynamics in dissipative many-body Rydberg systems,"We study the impact of dephasing on the excitation dynamics of a cloud of
ultracold two-level Rydberg atoms for both resonant and off-resonant laser
excitation, using the wave function Monte Carlo (MCWF) technique. We find that
while for resonant laser driving, dephasing mainly leads to an increase of the
Rydberg population and a decrease of the Mandel Q parameter, at off-resonant
driving strong dephasing toggles between direct excitation of pairs of atoms
and subsequent excitation of single atoms, respectively. These two excitation
mechanisms can be directly quantified via the pair correlation function, which
shows strong suppression of the two-photon resonance peak for strong dephasing.
Consequently, qualitatively different dynamics arise in the excitation
statistics for weak and strong dephasing in off-resonant excitation. Our
findings show that time-resolved excitation number measurements can serve as a
powerful tool to identify the dominating process in the system's excitation
dynamics.",1401.7260v1
2014-02-13,Effective-range approximations for resonant scattering of cold atoms,"Studies of cold atom collisions and few-body interactions often require the
energy dependence of the scattering phase shift, which is usually expressed in
terms of an effective-range expansion. We use accurate coupled-channel
calculations on $^{6}$Li, $^{39}$K and $^{133}$Cs to explore the behavior of
the effective range in the vicinity of both broad and narrow Feshbach
resonances. We show that commonly used expressions for the effective range
break down dramatically for narrow resonances and near the zero-crossings of
broad resonances. We present an alternative parametrization of the effective
range that is accurate through both the pole and the zero-crossing for both
broad and narrow resonances. However, the effective range expansion can still
fail at quite low collision energies, particularly around narrow resonances. We
demonstrate that an analytical form of an energy and magnetic field-dependent
phase shift, based on multichannel quantum defect theory, gives accurate
results for the energy-dependent scattering length.",1402.3272v3
2014-02-14,Multiresonance and chaotic behavior analysis for polarization in material modeled by multifrequency excitations duffing oscillator,"This paper considers nonlinear dynamics of polarization oscillations when
some materials when they are subjected to the action of an electromagnetic wave
modeled by multifrequency forced Duffing equation. Multiresonance and chaotic
behavior are analysed. For analysis of the case of resonance, the method of
multiple scales is used and it has been found from the equation of the
amplitudes for each of the possible resonance system. Possible resonances are
inter alia the resonances or sub superharmonic, the primary resonance and other
resonances called secondary. The phenomena of amplitude jump and hysteresis for
polarization were observed and analyzed. Finally, the study of chaotic behavior
for polarization was made by numerical simulation using the Runge- Kutta fourth
order.",1402.3420v1
2014-02-19,Resonant Compton scattering associated with pair creation,"Studies of Compton scattering by relativistic electrons in a strong magnetic
field have been restricted to either incident photon angles $\theta'$ aligned
along the magnetic field $B$ or incident photon energies $\omega'$ below the
first pair creation threshold $\omega'_{PC}$. When these restrictions are
relaxed there is a resonance in Compton scattering associated with pair
creation (PC), that is analogous to but independent of known resonances
associated with gyromagnetic absorption (GA). As with the GA resonances, that
may be labeled by the Landau quantum numbers of the relevant states, there is a
sequence of PC resonances where the scattering cross section diverges. In this
paper, the lowest divergence is studied for incident photon energies satisfying
${\omega'}^2\sin^2\theta'/(2eB)\ll1$, assuming that the scattering electron is
in its ground (Landau) state. This lowest resonance affects only
parallel-polarized photons.",1402.4530v1
2014-04-26,Multichannel quantum-defect theory for magnetic Feshbach resonances in heteronuclear group I systems,"We present a multichannel quantum-defect theory for magnetic Feshbach
resonances in the interaction of two heteronuclear group I atoms. The theory
provides a unified and a uniform description of resonances in all partial
waves, and enables the characterization of large number of resonances in terms
of very few parameters. For the sample system of $^6$Li$^{40}$K, we present
descriptions of all resonances in $aa$, $ab$, and $ba$ channels, in partial
waves $s$ ($l=0$) through $h$ ($l=5$), and in a magnetic field of 0 through
1000 Gauss. All resonances, including those in nonzero partial waves, are fully
characterized using the newly developed parametrization of Gao [Phy. Rev. A
\textbf{84}, 022706 (2011)].",1404.6676v1
2014-04-30,Plasmonic amplification and suppression in nanowaveguide coupled to gain-assisted high-quality plasmon resonances,"We theoretically study transmission in nanowaveguide coupled to high-quality
plasmon resonances for which the metal loss is overcompensated by gain. The
on-resonance transmission can vary widely from lower than --20dB to higher than
20dB for a range of gain coefficient. A reversible transition between the
high-quality amplification and the suppression can be induced by a quite small
change of gain coefficient for a moderately increased distance between the
waveguide and the resonator. It is expected that in practice a small change of
gain coefficient can be made by flexibly controlling pumping rate or utilizing
nonlinear gain. Additionally, based on the frequency-dependant model for
gain-transition susceptibility, it is shown that the wide variation of the
on-resonance transmission can also be observed for defferent detuning of the
gain-transition line-center. Such a widely controllable on-resonance
transmission is promising for applications such as well-controlled lumped
amplification of surface plasmon-polariton as well as plasmonic switching.",1404.7576v1
2014-07-08,Phase Noise in the Delta Kicked Rotor: From Quantum to Classical,"We experimentally investigate the effects of phase noise on the resonant and
non-resonant dynamics of the atom-optics kicked rotor. Employing sinusoidal
phase modulation at various frequencies, resonances are found corresponding to
periodic phase shifts, resulting in the effective transformation of quantum
anti-resonances into resonances and vice-versa. The stability of the resonance
is analysed, with the aid of experiments, epsilon-classical theory and
numerical simulations, and is found to be surprisingly robust against phase
noise. Finally we look into the effects of phase noise on dynamical
localization and discuss the destruction of the localization in terms of
decoherence.",1407.1921v2
2014-07-17,Isotopic Resonance Hypothesis: Experimental Verification by Escherichia coli Growth Measurements,"Isotopic composition of reactants affects the rates of chemical and
biochemical reactions. As a rule, enrichment of heavy stable isotopes leads to
slower reactions. But the recent isotopic resonance hypothesis suggests that
the dependence of the reaction rate upon the enrichment degree is not
monotonous; instead, at some resonance isotopic compositions, the kinetics
increases, while at off resonance compositions the same reactions progress
slower. To test the predictions of this hypothesis for the elements C, H, N and
O, we designed a precise (standard error plus or minus 0.05%) experiment to
measure the bacterial growth parameters in minimal media with varying isotopic
compositions. A number of predicted resonance conditions were tested, which
kinetic enhancements as strong as plus 3% discovered at these conditions. The
combined evidence extremely strongly supports the existence of isotopic
resonances. This phenomenon has numerous implications for the origin of life
and astrobiology, and possible applications in agriculture, biotechnology,
medicine and other areas.",1407.4847v1
2014-07-21,Electroluminescence and multi-photon effects in a resonator driven by a tunnel junction,"We consider a transmission line resonator which is driven by electrons
tunneling through a voltage-biased tunnel junction. Using the Born-Markovian
quantum master equation in the polaron basis we investigate the nonequilibrium
photon state and emission spectrum of the resonator as well as properties of
the transport current across the tunnel junction and its noise spectrum. The
electroluminescence is optimized, with maximum peak height and narrow
linewidth, when the back-action of the tunnel junction on the resonator and the
decay rate of the resonator are similar in strength. For strong coupling
between the resonator and tunnel junction, multi-photon effects show up in the
noise spectrum of the transport current.",1407.5460v1
2014-08-06,Wavelength-Tunable Infrared Metamaterial by Tailoring Magnetic Resonance Condition with VO2 Phase Transition,"In this work, we report the design of a wavelength-tunable infrared
metamaterial by exciting magnetic resonance with phase transition of vanadium
dioxide (VO2). Numerical simulation shows a broad absorption peak at the
wavelength of 10.9 um when VO2 is a metal, but it shifts to 15.1 um when VO2
changes to dielectric phase below its phase transition temperature of 68degC.
The large tunability of 38.5% in the resonance wavelength stems from the
different excitation conditions of magnetic resonance assisted by plasmon in
metallic VO2 but optical phonons in dielectric VO2. The physical mechanism is
elucidated with the aid of electromagnetic field distribution at the resonance
wavelengths. A hybrid magnetic resonance mode due to plasmon-phonon coupling is
also discussed. The results here would be beneficial for active control in
novel electronic, optical and thermal devices.",1408.1356v1
2014-09-17,Nonhermitian transport effects in coupled-resonator optical waveguides,"Coupled-resonator optical waveguides (CROWs) are known to have interesting
and useful dispersion properties. Here, we study the transport in these
waveguides in the general case where each resonator is open and asymmetric,
i.e., is leaky and possesses no mirror-reflection symmetry. Each individual
resonator then exhibits asymmetric backscattering between clockwise and
counterclockwise propagating waves, which in combination with the losses
induces non-orthogonal eigenmodes. In a chain of such resonators, the coupling
between the resonators induces an additional source of non-hermiticity, and a
complex band structure arises. We show that in this situation the group
velocity of wave packets differs from the velocity associated with the
probability density flux, with the difference arising from a non-hermitian
correction to the Hellmann-Feynman theorem. Exploring these features
numerically in a realistic scenario, we find that the complex band structure
comprises almost-real branches and complex branches, which are joined by
exceptional points, i.e., nonhermitian degeneracies at which not only the
frequencies and decay rates coalesce but also the eigenmodes themselves. The
non-hermitian corrections to the group velocity are largest in the regions
around the exceptional points.",1409.5037v1
2014-09-21,Soliton Formation in Whispering-Gallery-Mode Resonators via Input Phase Modulation,"We propose a method for soliton formation in whispering-gallery-mode (WGM)
resonators through input phase modulation. Our numerical simulations of a
variant of the Lugiato-Lefever equation suggest that modulating the input phase
at a frequency equal to the resonator free-spectral-range and at modest
modulation depths provides a deterministic route towards soliton formation in
WGM resonators without undergoing a chaotic phase. We show that the generated
solitonic state is sustained when the modulation is turned off adiabatically.
Our results support parametric seeding as a powerful means of control, besides
input pump power and pump-resonance detuning, over frequency comb generation in
WGM resonators. Our findings also help pave the path towards ultra-short pulse
formation on a chip.",1409.5943v3
2014-10-09,Resonant mode conversion in the waveguides with an unbroken and broken PT-symmetry,"We study resonant mode conversion in the PT-symmetric multimode waveguides,
where symmetry breaking manifests itself in sequential destabilization
(appearance of the complex eigenvalues) of the pairs of adjacent guided modes.
We show that the efficient mode conversion is possible even in the presence of
the resonant longitudinal modulation of the complex refractive index. The
distinguishing feature of the resonant mode conversion in the PT-symmetric
structure is a drastic growth of the width of the resonance curve when the
gain/losses coefficient approaches a critical value, at which symmetry breaking
occurs. We found that in the system with broken symmetry the resonant coupling
between exponentially growing mode with stable higher-order one effectively
stabilizes dynamically coupled pair of modes and remarkably diminishes the
average rate of the total power growth.",1410.2422v1
2014-10-14,Spin precession mapping at ferromagnetic resonance via nuclear resonant scattering,"We probe the spin dynamics in a thin magnetic film at ferromagnetic resonance
by nuclear resonant scattering of synchrotron radiation at the 14.4 keV
resonance of $^{57}$Fe. The precession of the magnetization leads to an
apparent reduction of the magnetic hyperfine field acting at the $^{57}$Fe
nuclei. The spin dynamics is described in a stochastic relaxation model adapted
to the ferromagnetic resonance theory by Smit and Beljers to model the decay of
the excited nuclear state. From the fits of the measured data the shape of the
precession cone of the spins is determined. Our results open a new perspective
to determine magnetization dynamics in layered structures with very high depth
resolution by employing ultrathin isotopic probe layers.",1410.3689v1
2014-11-19,Global surface wave resonances of the earth magnetosphere and their possible manifestation,"In this paper global surface wave modes supported by plasma discontinuities
at both the magnetopause and the plasmapause are considered. The ionosphere at
the ends of the magnetic field lines of the earth outer magnetosphere is
considered as reflecting boundaries of the surface waves that propagate along
the plasma boundaries. As a result a standing wave structure along the magnetic
field fluxes of the outer magnetosphere, i.e. surface wave resonance structure
can be formed. Due to quantized wavenumbers along the magnetic field lines, the
surface wave resonance possesses quantified frequencies in a following way: f =
nfres, where fres is frequency of the corresponding fundamental surface wave
resonance and n is an integer. Global Pc5 pulsations have been observed and
interpreted mostly as cavity modes of the earth magnetosphere. The global Pc5
pulsations however could alternatively be interpreted as ultra low-frequency
surface wave resonances of the earth magnetosphere that do not necessarily
involve the cavity mode-field aligned resonance transformation concept.",1411.5218v1
2014-11-25,Optimization of Coplanar Waveguide Resonators for ESR Studies on Metals,"We present simulations and analytic calculations of the electromagnetic
microwave fields of coplanar waveguide (CPW) resonators in the vicinity of
highly conducting metallic samples. The CPW structures are designed with the
aim of investigating electron spin resonance (ESR) in metallic heavy-fermion
systems, in particular YbRh$_2$Si$_2$, close to the quantum critical point.
Utilizing CPW resonators for ESR experiments allows for studies at mK
temperatures and a wide range of freely selectable frequencies. It is therefore
of great interest to evaluate the performance of resonant CPW structures with
nearby metallic samples. Here we study the microwave fields at the sample
surface as a function of sample distance from the waveguide structure and
analyze the implications of the sample on the performance of the resonator. The
simulation results reveal an optimum sample distance for which the microwave
magnetic fields at the sample are maximized and thus best suited for ESR
studies.",1411.6858v1
2014-12-01,Asymptotic model for shape resonance control of diatomics by intense non-resonant light,"We derive a universal model for atom pairs interacting with non-resonant
light via the polarizability anisotropy, based on the long range properties of
the scattering. The corresponding dynamics can be obtained using a nodal line
technique to solve the asymptotic Schr\""odinger equation. It consists in
imposing physical boundary conditions at long range and vanishing of the
wavefunction at a position separating inner zone and asymptotic region. We show
that nodal lines which depend on the intensity of the non-resonant light can
satisfactorily account for the effect of the polarizability at short range. The
approach allows to determine the resonance structure, energy, width, channel
mixing and hybridization even for narrow resonances.",1412.0569v1
2014-12-02,Broadband Electrically Detected Magnetic Resonance Using Adiabatic Pulses,"We present a broadband microwave setup for electrically detected magnetic
resonance (EDMR) based on microwave antennae with the ability to apply
arbitrarily shaped pulses for the excitation of electron spin resonance (ESR)
and nuclear magnetic resonance (NMR) of spin ensembles. This setup uses
non-resonant stripline structures for on-chip microwave delivery and is
demonstrated to work in the frequency range from 4 MHz to 18 GHz. $\pi$ pulse
times of 50 ns and 70 $\mu$s for ESR and NMR transitions, respectively, are
achieved with as little as 100 mW of microwave or radiofrequency power. The use
of adiabatic pulses fully compensates for the microwave magnetic field
inhomogeneity of the stripline antennae, as demonstrated with the help of BIR4
unitary rotation pulses driving the ESR transition of neutral phosphorus donors
in silicon and the NMR transitions of ionized phosphorus donors as detected by
electron nuclear double resonance (ENDOR).",1412.0842v1
2014-12-10,"Multicomponent long-wave--short-wave resonance interaction system: Bright solitons, energy-sharing collisions, and resonant solitons","We consider a general multicomponent (2+1)-dimensional long-wave--short-wave
resonance interaction (LSRI) system with arbitrary nonlinearity coefficients,
which describes the nonlinear resonance interaction of multiple short waves
with a long-wave in two spatial dimensions. The general multicomponent LSRI
system is shown to be integrable by performing the Painlev\'e analysis. Then we
construct the exact bright multi-soliton solutions by applying the Hirota's
bilinearization method and study the propagation and collision dynamics of
bright solitons in detail. Particularly, we investigate the head-on and
overtaking collisions of bright solitons and explore two types of
energy-sharing collisions as well as standard elastic collision. We have also
corroborated the obtained analytical one-soliton solution by direct numerical
simulation. Also, we discuss the formation and dynamics of resonant solitons.
Interestingly, we demonstrate the formation of resonant solitons admitting
breather-like (localized periodic pulse train) structure and also large
amplitude localized structures akin to rogue waves coexisting with solitons.
For completeness, we have also obtained dark one- and two-soliton solutions and
studied their dynamics briefly.",1412.3201v1
2014-12-15,Attosecond time delay in the photoionization of Mn in the region of the $3p \rightarrow 3d$ giant resonance,"The initial insight into time delay in Mn photoionization in the region of
the $3p \to 3d$ giant autoionization resonance is gained in the framework of
the ""spin-polarized"" random phase approximation with exchange. The dramatic
effect of the giant autoionization resonance on time delay of photoemission
from the $3d$ and $4s$ valence subshells of the Mn atom is unraveled. Strong
sensitivity of the time delay of the $4s$ photoemission to the final-state term
of the ion-remainder [${\rm Mn^{+}}(4s^{1},$$^{5}S)$ vs.~${\rm
Mn^{+}}(4s^{1},$$^{7}S)$] is discovered. It is shown that photoionization time
delay in the autoionizing resonance region is explicitly associated with the
resonance lifetime, which can, thus, be directly measured in attosecond time
delay experiments. Similar features are expected to emerge in photoionization
time delays of other transition-metal and rare-earth atoms with half-filed
subshells that possess giant autoionization resonances as well.",1412.4730v2
2014-12-29,Perfect and broadband acoustic absorption by critical coupling,"We experimentally and analytically report broadband and narrowband perfect
absorption in two different acoustic waveguide-resonator geometries by the
mechanism of critical coupling. In the first geometry the resonator (a
Helmholtz resonator) is side-loaded to the waveguide and it has a moderate
quality factor. In the second geometry the resonator (a viscoelastic porous
plate) is in-line loaded and it contains two resonant modes with low quality
factor. The interplay between the energy leakage of the resonant modes into the
waveguide and the inherent losses of the system reveals a perfect and a
broadband nearly perfect absorption. The results shown in this work can
motivate relevant research for the design of broadband perfect absorbers in
other domains of wave physics.",1501.00191v1
2015-01-15,Resonances as Probes of Heavy-Ion Collisions at ALICE,"Hadronic resonances serve as unique probes in the study of the hot and dense
nuclear matter produced in heavy-ion collisions. Properties of the hadronic
phase of the collision can be extracted from measurements of the suppression of
resonance yields. A comparison of the transverse-momentum spectra of the
phi(1020) meson and the proton (which have similar masses) can be used to study
particle production mechanisms. Resonance measurements in pp collisions provide
input for tuning QCD-inspired particle production models and serve as reference
measurements for other collision systems. Measurements of resonances in p-Pb
collisions allow nuclear effects in the absence of a hot and dense final state
to be studied. The ALICE Collaboration has measured resonances in pp, p-Pb, and
Pb-Pb collisions. These measurements will be discussed and compared to results
from other experiments and to theoretical models.",1501.03797v1
2015-01-19,The twofold emergence of the $a_1$ axial vector meson in high energy hadronic production,"The high statistics COMPASS results on diffractive dissociation $\pi N
\rightarrow \pi \pi \pi N$ suggest that the isospin $I=1$ spin-parity $J^{PC}=
1^{++}$ $a_1(1260)$ resonance could be split into two states: $a_1(1260)$
decaying into an S-wave $\rho\pi$ system, and $a_1^\prime(1420)$ decaying into
a P-wave $f_0(980)\pi$ system. We analyse the reaction by incorporating our
previous treatment of resonant re-scattering corrections in the Drell-Deck
forward production process. Our results show that the COMPASS results are fully
consistent with the existence of a single axial-vector $a_1$ resonance. The
characteristic structure of the production process, which differs in the two
orbital angular momentum states, plays a crucial role in this determination.
Provided the theoretical analysis of the reaction is done in a consistent
manner, this single resonance produces two peaks at different locations in the
two channels, with a rapid increase of the phase difference between their
amplitudes arising mainly from the structure of the production process itself,
and not from a dynamical resonance effect. In addition, this analysis clarifies
questions related to the mass, width, and decay rates of the $a_1$ resonance.",1501.04643v1
2015-01-16,Coupled mode theory for acoustic resonators,"We develop the effective non-Hermitian Hamiltonian approach for open systems
with Neumann boundary conditions. The approach can be used for calculating the
scattering matrix and the scattering function in open resonator-waveguide
systems. In higher than one dimensions the method represents acoustic coupled
mode theory in which the scattering solution within an open resonator is found
in the form of expansion over the eigenmodes of the closed resonator decoupled
from the waveguides. The problem of finding the transmission spectra is reduced
to solving a set of linear equations with a non-Hermitian matrix whose
anti-Hermitian term accounts for coupling between the resonator eigenmodes and
the scattering channels of the waveguides. Numerical applications to acoustic
two-, and three-dimensional resonator-waveguide problems are considered.",1501.04653v2
2015-02-04,Hybridization and the origin of the Fano resonances in symmetric nanoparticle trimers,"We study the light scattering by plasmonic and dielectric symmetric trimers
to investigate the existence of polarization-independent Fano resonances.
Plasmonic hybridization theory is revealed to hide simple physics, and we
instead provide a simplified model for hybridization to derive a plasmonic
trimer's eigenmodes analytically. This approach is demonstrated to accurately
recreate full wave simulations of plasmonic trimers and their Fano resonances.
We are subsequently able to deduce the grounds for modal interference in
plasmonic trimers and the related formation of Fano resonances. However, by
taking advantage of the generality of our simplified hybridization approach, we
are also able to investigate the eigenmodes of all-dielectric trimers. We show
that bianisotropic coupling channels between high-index dielectric
nanoparticles are able to increase the capacity for Fano resonances, even at
normal incidence. We finally provide the first experimental measurements of
sharp, polarization-independent Fano resonances from a symmetric all-dielectric
trimer, with very good agreement to the predicted response from our simplified
hybridization theory.",1502.01308v2
2015-02-11,On the mass determination in liquid utilizing measurement of only the fundamental flexural resonances of the micro-/nanomechanical based mass sensors,"Micro-/nanomechanical mass sensors are capable to quantitatively determine
molecule mass from only first three (two) measured cantilever (bridge) resonant
frequencies. However, in liquid solutions that are relevant to most of the
biological systems, the mass determination is challenging because the Q-factor
due to fluid damping decreases and, as a result, usually just the fundamental
resonant frequencies can be correctly identified. Moreover, for higher modes
the resonance coupling, noise and internal damping have been proven to strongly
affect the measured resonant frequencies and, correspondingly, the accuracy of
the estimated masses. Here, we derive the easy accessible expressions enabling
the quantitative mass(es) determination just from the fundamental resonant
frequencies of the micro/nanomechanical mass sensor under intentionally applied
axial tension, which can be easily created and controlled by the electrostatic
or magnetostatic forces. We also show that typically achievable force
resolution has a negligible impact on the mass determination and the mass
sensitivity.",1502.03232v1
2015-02-18,Observation of a surface lattice resonance in a fractal arrangement of gold nanoparticles,"The collective response of closely spaced metal particles in non-periodic
arrangements has the potential to provide a beneficial angular and frequency
dependence in sensing applications. In this paper, we investigate the optical
response of a Sierpinski fractal arrangement of gold nanoparticles and show
that it supports a collective resonance similar to the surface lattice
resonances that exist in periodic arrangements of plasmonic resonators. Using
back focal plane microscopy, we observe the leakage of radiation out of a
surface lattice resonance that is efficiently excited when the wavenumber of
the incident light matches a strong Fourier component of the fractal structure.
The efficient coupling between localized surface plasmons leads to a collective
resonance and a Fano-like feature in the scattering spectrum. Our experimental
observations are supported by numerical simulations based on the coupled-dipole
approximation and finite-difference time-domain methods. This work presents a
first step towards the application of fractal arrangements for plasmonic
applications",1502.05181v1
2015-03-02,Strange Baryonic Resonances and Resonances Coupling to Strange Hadrons at SIS Energies,"The role played by baryonic resonances in the production of final states
containing strangeness for proton-proton reactions at 3.5 GeV measured by HADES
is discussed by means of several very different measurements. First the
associate production of $\Delta$ resonances accompanying final states with
strange hadrons is presented, then the role of interferences among N$^*$
resonances, as measured by HADES for the first time, is summarised. Last but
not least the role played by heavy resonances, with a mass larger than $2$
GeV/c$^2$ in the production of strange and non-strange hadrons is discussed.
Experimental evidence for the presence of a $\Delta(2000)^{++}$ are presented
and hypotheses are discussed employing the contribution of similar objects to
populate the excesses measured by HADES for the $\Xi$ in A+A and p+A collisions
and in the dilepton sector for A+A collisions. This extensive set of results
helps to better understand the dynamic underlaying particle production in
elementary reactions and sets a more solid basis for the understanding of heavy
ion collisions at the same energies and even higher as planned at the FAIR
facility.",1503.00616v1
2015-03-09,Shifts and widths of p-wave confinement induced resonances in atomic waveguides,"We develop and analyze a theoretical model to study p-wave Feshbach
resonances of identical fermions in atomic waveguides by extending the
two-channel model of A.D. Lange et. al. [Phys. Rev. A 79, 013622 (2009)] and S.
Saeidian et. al. [Phys. Rev. A 86, 062713 (2012)]. The experimentally known
parameters of Feshbach resonances in free space are used as input of the model.
We calculate the shifts and widths of p-wave magnetic Feshbach resonance of
$^{40}$K atoms emerging in harmonic waveguides as p-wave confinement induced
resonance (CIR). Particularly, we show a possibility to control the width and
shift of the p-wave confinement induced resonance by the trap frequency and the
applied magnetic field which could be used in corresponding experiments. Our
analysis also demonstrates the importance of the inclusion of the effective
radius in the computational schemes for the description of the p-wave CIRs
contrary to the case of s-wave CIRs where the influence of this term is
negligible.",1503.02469v1
2015-03-20,Resonant bowtie aperture nano-antenna for the control of optical nanocavities resonance,"Scanning Near-field Optical Microscopy (SNOM) has been successful in finely
tuning the optical properties of photonic crystal (PC) nanocavities. The SNOM
nanoprobes proposed so far allowed for either redshifting or blueshifting the
resonance peak of the PC structures. In this Letter, we theoretically
demonstrate the possibility of redshifting (up to +0.65nm) and blueshifting (up
to $-5$~nm) PC cavity resonance with a single SNOM probe. This probe is
obtained by opening a bowtie-aperture nano-antenna (BNA) at the apex of a
metal-coated tip. This double-way PC tunability is the result of a competition
between the effects of the BNA resonance (induced electric dipole leading to a
redshift) and the metal-coated tip (induced magnetic dipole giving rise to a
blueshift) onto the PC mode volume. The sign of the spectral shift is modified
by simply controlling the tip-to-PC distance. This study opens the way to the
full postproduction control of the resonance wavelength of high quality factor
optical cavities.",1503.06084v1
2015-03-20,The Dynamics of Centaurs in the Vicinity of the 2:1 Mean Motion Resonance of Neptune and Uranus Trojan Region,"In this work we present the results of a suite of dynamical simulations
following the orbital evolution of 8,022 hypothetical Centaur objects. These
Centaurs begin our integrations on orbits in the vicinity of the 2:1 mean
motion resonance with Neptune, and we follow their dynamical evolution for a
period of 3 Myr under the gravitational influence of a motionless Sun and the
four Jovian planets. The great majority of the test particles studied rapidly
escaped from the vicinity of the 2:1 mean motion resonance of Neptune and
diffused throughout the Solar System. The average libration time of Centaurs in
the vicinity of 2:1 mean motion resonance of Neptune was found to be just 27
kyr. Although two particles did remain near the resonance for more than 1 Myr.
Upon leaving the vicinity of the 2:1 resonance, the majority of test particles
evolved by a process of random walk in semi-major axis, due to repeated close
encounters with the giant planets.",1503.06096v1
2015-04-04,Design of Black Phosphorus 2D Nanomechanical Resonators by Exploiting the Intrinsic Mechanical Anisotropy,"Black phosphorus (P), a layered material that can be isolated down to
individual 2D crystalline sheets, exhibits highly anisotropic mechanical
properties due to its corrugated crystal structure in each atomic layer, which
are intriguing for 2D nanomechanical devices. Here we lay the framework for
describing the mechanical resonant responses in free-standing black P
structures, by using a combination of analytical modeling and numerical
simulation. We find that thicker devices (>100nm) operating in the elastic
plate regime exhibit pronounced signatures of mechanical anisotropy, and can
lead to new multimode resonant characteristics in terms of mode sequences,
shapes, and orientational preferences that are unavailable in nanomechanical
resonators made of isotropic materials. In addition, through investigating
devices with different geometries, we identify the resonant response's
dependence on crystal orientation in asymmetric devices, and evaluate the
effects from the degree of anisotropy. The results suggest a pathway towards
harnessing the mechanical anisotropy in black P for building novel 2D
nanomechanical devices and resonant transducers with engineerable multimode
functions.",1504.01060v1
2015-04-21,Finite-temperature effects on a triatomic Efimov resonance in ultracold cesium,"We report a thorough investigation of finite-temperature effects on
three-body recombination near a triatomic Efimov resonance in an ultracold gas
of cesium atoms. Our measurements cover a wide range from a near-ideal
realization of the zero-temperature limit to a strongly temperature-dominated
regime. The experimental results are analyzed within a recently introduced
theoretical model based on a universal zero-range theory. The
temperature-induced shift of the resonance reveals a contribution that points
to an energy-dependence of the three-body parameter. We interpret this
contribution in terms of the finite range of the van der Waals interaction in
real atomic systems and we quantify it in an empirical way based on length
scale arguments. A universal character of the corresponding resonance shift is
suggested by observations related to other Efimov resonances and the comparison
with a theoretical finite-temperature approach that explicitly takes the van
der Waals interaction into account. Our findings are of importance for the
precise determination of Efimov resonance positions from experiments at finite
temperatures.",1504.05360v1
2015-05-01,Dip or nothingness of a Higgs resonance from the interference with a complex phase,"We show that new resonance shapes -- a pure dip, nothingness and an enhanced
pure peak -- can be produced from the interference between resonance and
continuum with a relative phase. Production conditions of those new shapes are
derived based on a general parameterization of the interference. The narrow
width approximation is modified to work with the non-zero imaginary part of
interference, and the correction factor can characterize the resonance shape.
We demonstrate that the new resonance shapes of heavy Higgs bosons, $H^0$ and
$A^0$ in the Type II aligned two Higgs doublet model, generally show up in $gg
\to H^0/A^0 \to t\bar{t}$ as well as $b\bar{b}$ and $\gamma \gamma$ channels.
The pure $A^0$ resonance dip in the $t\bar{t}$ channel is a particularly
interesting signal as it can be probed well by the current search techniques
that do not even take into account interferences; the high-luminosity LHC 14
TeV can perhaps probe a large part of its parameter space.",1505.00291v2
2015-05-11,Creating and Probing Electron Whispering Gallery Modes in Graphene,"Designing high-finesse resonant cavities for electronic waves faces
challenges due to short electron coherence lengths in solids. Previous
approaches, e.g. the seminal nanometer-sized quantum corrals, depend on careful
positioning of adatoms at clean surfaces. Here we demonstrate an entirely
different approach, inspired by the peculiar acoustic phenomena in whispering
galleries. Taking advantage of graphene's unique properties, namely
gate-tunable light-like carriers, we create Whispering Gallery Mode (WGM)
resonators defined by circular pn-junctions, induced by a scanning tunneling
probe. We can tune the resonator size and the carrier concentration under the
probe in a back-gated graphene device over a wide range, independently and in
situ. The confined modes, revealed through characteristic resonances in the
tunneling spectrum, originate from Klein scattering at pn junction boundaries.
The WGM-type confinement and resonances are a new addition to the quantum
electron-optics toolbox, paving the way to real-world electronic lenses and
resonators.",1505.02732v1
2015-05-14,Electromagnetically induced transparency resonances inverted in magnetic field,"The electromagnetically induced transparency (EIT) phenomenon has been
investigated in a $\Lambda$-system of the $^{87}$Rb D$_1$ line in an external
transverse magnetic field. Two spectroscopic cells having strongly different
values of the relaxation rates $\gamma_{rel}$ are used: a Rb cell with
antirelaxation coating ($L\sim$1 cm) and a Rb nanometric-thin cell (nano-cell)
with thickness of the atomic vapor column $L$=795nm. For the EIT in the
nano-cell, we have the usual EIT resonances characterized by a reduction in the
absorption (i.e. dark resonance (DR)), whereas for the EIT in the Rb cell with
an antirelaxation coating, the resonances demonstrate an increase in the
absorption (i.e. bright resonances). We suppose that such unusual behavior of
the EIT resonances (i.e. the reversal of the sign from DR to BR) is caused by
the influence of alignment process. The influence of alignment strongly depends
on the configuration of the coupling and probe frequencies as well as on the
configuration of the magnetic field.",1505.03856v1
2015-05-14,Neighboring Interactions in a Periodic Plasmonic Material for Solar-Thermal Energy Conversion,"A periodic plasmonic meta-material was studied using finite-difference time
domain (FDTD) method to investigate the influence of neighboring particles on
the near unity optical absorptivity. The meta-material was constructed as a
silver nanoparticle (20-90nm) situated above an alumina (Al$_2$O$_3$)
dielectric environment. A full parametric sweep of the particle width and the
dielectric thickness was conducted. Computational results identified several
resonances between the metal-dielectric and metal-air that have potential to
broadening the response through stacked geometry. A significant coupled
resonance between the metal-dielectric resonance and a cavity resonance between
particles was capture as a function of dielectric thickness. This coupled
resonance was not evident below dielectric thicknesses of 40nm and above cavity
widths of 20nm. Additionally, a noticeable propagating surface plasmon
polariton resonance was predicted when the particle width was half the unit
cell length.",1505.03886v1
2015-05-26,"The decay widths, the decay constants, and the branching fractions of a resonant state","We introduce the differential and the total decay widths of a resonant
(Gamow) state decaying into a continuum of stable states. When the resonance
has several decay modes, we introduce the corresponding partial decay widths
and branching fractions. In the approximation that the resonance is sharp, the
expressions for the differential, partial and total decay widths of a resonant
state bear a close resemblance with the Golden Rule. In such approximation, the
branching fractions of a resonant state are the same as the standard branching
fractions obtained by way of the Golden Rule. We also introduce dimensionless
decay constants along with their associated differential decay constants, and
we express experimentally measurable quantities such as the branching fractions
and the energy distributions of decay events in terms of those dimensionless
decay constants.",1505.07139v1
2015-05-28,Interplay between Detection Strategies and Stochastic Resonance Properties,"We discuss how to exploit stochastic resonance with the methods of
statistical theory of decisions. To do so, we evaluate two detection
strategies: escape time analysis and strobing. For a standard quartic bistable
system with a periodic drive and disturbed by noise, we show that the detection
strategies and the physics of the double well are connected, inasmuch as one
(the strobing strategy) is based on synchronization, while the other (escape
time analysis) is determined by the possibility to accumulate energy in the
oscillations. The analysis of the escape times best performs at the frequency
of the geometric resonance, while strobing shows a peak of the performances at
a special noise level predicted by the stochastic resonance theory. We surmise
that the detection properties of the quartic potential are generic for
overdamped and underdamped systems, in that the physical nature of resonance
decides the competition (in terms of performances) between different detection
strategies.",1505.07646v1
2015-06-19,The interplay between resonant enhancement and quantum path dynamics in harmonic generation in helium,"We present a theoretical study of the influence of resonant enhancement on
quantum path dynamics in the generation of harmonics above and below the
ionization threshold in helium. By varying the wavelength and intensity of the
driving field from 425 nm to 500 nm and from 30 TW/cm${^2}$ to 140 TW/cm${^2}$,
respectively, we identify enhancements of harmonics 7, 9, and 11 that
correspond to multiphoton resonances between the ground state and the Stark
shifted $1s2p$, $1s3p$, and $1s4p$ excited states. A time-frequency analysis of
the emission shows that both the short and long quantum path contributions to
the harmonic yield are enhanced through these bound state resonances. We
analyze the sub-cycle time structure of the 9th harmonic yield in the vicinity
of the resonances and find that on resonance the long trajectory contribution
is phase shifted by approximately $\pi/4$. Finally, we compare the single atom
and the macroscopic response of a helium gas and find that while the sub-cycle
time profiles are slightly distorted by propagation effects, the phase shift of
the long trajectory contribution is still recognizable.",1506.06160v1
2015-07-01,Quantum state transfer and controlled-phase gate on one-dimensional superconducting resonators assisted by a quantum bus,"We propose a quantum processor for the scalable quantum computation on
microwave photons in distant one-dimensional superconducting resonators. It is
composed of a common resonator R acting as a quantum bus and some distant
resonators $r_j$ coupled to the bus in different positions assisted by
superconducting quantum interferometer devices (SQUID), different from previous
processors. R is coupled to one transmon qutrit, and the coupling strengths
between $r_j$ and R can be fully tuned by the external flux through the SQUID.
To show the processor can be used to achieve universal quantum computation
effectively, we present a scheme to complete the high-fidelity quantum state
transfer between two distant microwave-photon resonators and another one for
the high-fidelity controlled-phase gate on them. By using the technique for
catching and releasing the microwave photons from resonators, our processor may
play an important role in quantum communication as well.",1507.00069v2
2015-07-13,Coupling quantum circuits to magnetic molecular qubits,"This thesis explores the coupling of magnetic systems to quantum circuits in
the context of quantum computing applications. In particular we study the
coupling of superconducting coplanar waveguide resonators to Single Molecule
Magnets (SMMs) . The combination of approaches from the fields of Cavity
Quantum electrodynamics (QED) and Circuit QED with those from the field of
molecular magnetism con provide unique opportunities for quantum computing. We
investigate the necessary conditions for coupling single spins and spin
ensembles to resonators and what characteristics SMMs should have in order to
provide interesting alternatives as quantum bits. We present test measurements
of several magnetic samples using both broadband spectroscopy with open
waveguides and EPR spectroscopy using coplanar waveguide resonators. We also
design, fabricate, and test nanometric constrictions in superconducting
resonators with the objective of improving their coupling to single spins. We
evaluate the performance of these constricted resonators in comparison to
unmodified resonators.",1507.03579v2
2015-08-20,Origin of coda waves: earthquake source resonance,"Coda in local earthquake exhibits resonance-like wave behaviour where the
coda emerges as long-duration small-amplitude vibration with selective
frequency, slow temporal decay, and uniform spatial energy distribution around
the earthquake source. Coda is thought to be the incoherent waves scattered
from random small-scale heterogeneity in the earth's lithosphere. Here I show
that the coda is primarily attributed to the natural resonance in strong
small-scale heterogeneity around the earthquake's hypocenter through seismic
wave field modeling for 1D heterogeneity. The natural resonance is evolved from
the low frequency resonance (LFR) in transient regime and is an emergent
phenomenon that occurs in steady state regime. Its resonance frequency
decreases with increasing heterogeneous scale, impedance contrast, or random
heterogeneous scale and velocity fluctuations; its intensity diminishes with
decreasing impedance contrast or increasing random heterogeneous scale and
velocity fluctuations.",1508.04873v4
2015-09-09,Interference Effect on Resonance Studies in Searches of Heavy Particles,"The interference between resonance signal and continuum background can be
either constructive or destructive, depending on the relative sign of couplings
between the signal and background amplitudes. Different interference schemes
lead to asymmetric distortions of the resonance line shape, which could be
distinguished in experiments, when the internal resonance width is larger than
the detector resolution. Interpreting the ATLAS diboson excesses by means of a
toy $W'$ model as an illustrative example (though it is disfavored by the 13
TeV data), we find that the signs of resonance couplings can only be revealed
in the line shape measurements up to a high confidence level at a high
luminosity, which could bring us further information on the underlying theory
beyond resonance searches at future lepton and hadron colliders.",1509.02787v3
2015-09-29,Resonant electron scattering by graphene antidot,"The edge states which were observed on a linear edge of graphene may also
persist on a curved edge. We calculate the elastic transport scattering cross
section on a graphene nanohole supporting the edge states. Resonant peaks in
the gate voltage dependence of conductivity of graphene with such nanoholes are
obtained. Position and height of the resonances are determined by the
localization depth of the quasibound edge states, and width -- by their
lifetime. The scattering amplitude near the resonant energies has a strong
valley asymmetry. We evaluate the effect of moderate edge rippling,
inhomogeneity of boundary parameter along the edge, and Coulomb effects
(charged nanohole) on the edge states and show that they do not affect the
presence of the resonances, but can substantially influence their position,
height and width. The local density of states near the nanohole also
demonstrates a resonant dependence on gate voltage.",1509.08698v1
2015-10-01,Imaging resonances in low-energy NO-He inelastic collisions,"In molecular collisions, resonances occur at specific energies where the
colliding particles temporarily form quasi-bound complexes, resulting in rapid
variations in the energy dependence of scattering cross sections.
Experimentally, it has proven challenging to observe such scattering
resonances, especially in differential cross sections. We report the
observation of resonance fingerprints in the state-to-state differential cross
sections for inelastic NO-He collisions in the 13 to 19 cm$^{-1}$ energy range
with 0.3 cm$^{-1}$ resolution. The observed structures were in excellent
agreement with quantum scattering calculations. They were analyzed by
separating the resonance contributions to the differential cross sections from
the background through a partitioning of the multichannel scattering matrix.
This revealed the partial wave composition of the resonances, and their
evolution during the collision.",1510.00299v1
2015-10-01,Cavity-coupled guided resonances with high quality factors in photonic crystal heterostructures,"We study the optical characteristics of a photonic crystal (PhC)
heterostructure cavity consisting of two-dimensional monolayer PhC, sandwiched
between two identical passive multilayers. In the range of stopband of the
multilayer, guided resonance of the sandwiched PhC are excited by the
evanescent waves of the multilayer stack and the quality factor of these
cavity-coupled guided resonances is about 10e6. The calculated field
distribution facilitates the distinction between the cavity defect modes and
the coupled guided resonances of the proposed design. The line shapes of the
resonances are explained using a theoretical model. Significant decrease in the
lasing threshold is observed for these resonant modes in comparison to the
defect modes. These results will find use in designing compact PhC-based
ultra-low threshold lasers and narrow band filters.",1510.00348v1
2015-10-18,Resonant Combinatorial Frequency Generation Induced by a PT-symmetric Periodic Layered Stack,"The nonlinear interaction of waves in PT-symmetric periodic stacks with an
embedded nonlinear anisotropic dielectric layer illuminated by plane waves of
two tones is examined. The three-wave interaction technique is applied to study
the nonlinear processes. It is shown that the intensity of the three-wave
mixing process can be significantly enhanced in resonant cavities based on
PT-symmetric periodic structures, especially as the pumping wave frequency is
near the coherent perfect absorber-lasing resonances. The main mechanisms and
properties of the combinatorial frequency generation and emission from the
stacks are illustrated by the simulation results and the effect of the layer
arrangement in PT-symmetric walls of resonator on the stack nonlinear response
is discussed. The enhanced efficiency of the frequency conversion at Wolf-Bragg
resonances is demonstrated. It has been shown that Wolf-Bragg resonances of
very high orders may lead to the global maxima and nulls of the scattered
field. The analysis of the effect of losses in nonlinear dielectric layer on
the combinatorial frequency generation efficiency has shown that the rate of
losses may amplify the intensity of the frequency mixing process.",1510.05243v1
2015-10-29,Color Discriminant Variable to Separate Dijet Resonances at the LHC,"A narrow resonance decaying to dijets could be discovered at the 14 TeV run
of the LHC. To quickly identify its color structure in a model-independent
manner, we introduced a method based on a color discriminant variable,
determined from the measurements of the resonance's production cross section,
mass and width. This talk introduces a more transparent theoretical formulation
of the color discriminant variable that highlights its relationship to the
branching ratios of the resonance into incoming and outgoing partons and to the
properties of those partons. The formulation makes it easier to predict the
value of the variable for a given class of resonance. We show that this method
applies well to color-triplet and color-sextet scalar diquarks, distinguishing
them clearly from other candidate resonances.",1510.08753v1
2015-11-05,High Kinetic Inductance Superconducting Nanowire Resonators for Circuit QED in a Magnetic Field,"We present superconducting microwave-frequency resonators based on NbTiN
nanowires. The small cross section of the nanowires minimizes vortex
generation, making the resonators resilient to magnetic fields. Measured
intrinsic quality factors exceed $2\times 10^5$ in a $6$ T in-plane magnetic
field, and $3\times 10^4$ in a $350$ mT perpendicular magnetic field. Due to
their high characteristic impedance, these resonators are expected to develop
zero-point voltage fluctuations one order of magnitude larger than in standard
coplanar waveguide resonators. These properties make the nanowire resonators
well suited for circuit QED experiments needing strong coupling to quantum
systems with small electric dipole moments and requiring a magnetic field, such
as electrons in single and double quantum dots.",1511.01760v1
2015-11-28,Spectral energy analysis of locally resonant nanophononic metamaterials by molecular simulations,"A nanophononic metamaterial is a new type of nanostructured material that
features an array, or a forest, of intrinsically distributed resonating
substructures. Each substructure exhibits numerous local resonances, each of
which may hybridize with the phonon dispersion of the underlying host material
causing significant reductions in the group velocities and consequently a
reduction in the lattice thermal conductivity. In this paper, molecular
dynamics simulations are utilized to investigate both the dynamics and the
thermal transport properties of a nanophononic metamaterial configuration
consisting of a freely suspended silicon membrane with an array of silicon
nanopillars standing on the surface. The simulations yield results consistent
with earlier lattice-dynamics based predictions which showed a reduction in the
thermal conductivity due to the presence of the local resonators. Using a
spectral energy density approach, in which only simulation data is utilized and
no a priori information on the nanostructure resonant phonon modes is provided,
we show direct evidence of the existence of resonance hybridizations as an
inherent mechanism contributing to the slowing down of thermal transport in
this system.",1511.08898v1
2015-12-28,On the possible new 750 GeV heavy boson resonance at the LHC,"We argue that the possible new heavy boson resonance of 750 GeV is an ideal
candidate as a twin particle of the 125 GeV scalar boson, both emerging from
the large mixing of the scalar toponium and scalar gluonium. The twin
pseudoscalar particles are expected to have smaller masses. The discovery of
the 750 GeV resonance is possible only with a much more data than for the 125
GeV resonance since only the gluonium component is detectable above the
toponium threshold. The similar type of the QCD resonances is expected in the
bottomonium-gluonium system. If the LHC will discover all these heavy
quarkonium-gluonium resonances, the absence of the Higgs scalar should not be
considered an obstacle because the nonsingular theory with the UV cutoff fixed
by the weak boson masses is superior to the Standard Model. Namely, it solves
the basic problems for the SM such as: (1) the existence of light neutrinos,
(2) dark matter particles to be the heavy Majorana neutrinos and (3) broken
lepton and baryon numbers.",1601.00618v4
2016-01-08,Phonon Josephson Junction with Nanomechanical Resonators,"We study coherent phonon oscillations and tunneling between two coupled
nonlinear nanomechanical resonators. We show that the coupling between two
nanomechanical resonators creates an effective phonon Josephson junction which
exhibits two different dynamical behaviors: Josephson oscillation (phonon-Rabi
oscillation) and macroscopic self-trapping (phonon blockade). Self-trapping
originates from mechanical nonlinearities, meaning that when the nonlinearity
exceeds its critical value, the energy exchange between the two resonators is
suppressed, and phonon-Josephson oscillations between them are completely
blocked. An effective classical Hamiltonian for the phonon Josephson junction
is derived and its mean-field dynamics is studied in phase space. Finally, we
study the phonon-phonon coherence quantified by the mean fringe visibility, and
show that the interaction between the two resonators may lead to the loss of
coherence in the phononic junction.",1601.01818v2
2016-01-10,Resonant splitting in periodic T-shape photonic waveguides,"Resonant splitting phenomena of photons in periodic T-shape waveguide
structure are investigated by the Green's function method. It is found that,
except for the (n-1)-fold resonant splitting in the low frequency region,
(n-2)-fold resonant splitting occurs in the high frequency region of the
transmission spectra. The (n-2)-fold resonant splitting peaks are induced by
the high quasi-bound states where the photons are mainly localized in the
constrictions rather than in the stubs. To this kind of quasi-bound state, the
stub acts as a potential barrier rather than a well, which is the inverse of
the case of the low quasi-bound states corresponding to the (n-1)-fold
splitting peaks. These resonant peaks can be modulated by adjusting the
periodic number and geometry of the waveguide structures.",1601.02222v1
2016-01-12,A Test Resonator for Kagome Hollow-Core Photonic Crystal Fibers for Resonant Rotation Sensing,"We build ring resonators to assess the potentialities of Kagome Hollow-Core
Photonic Crystal Fibers for future applications to resonant rotation sensing.
The large mode diameter of Kagome fibers permits to reduce the free space
fiber-to-fiber coupling losses, leading to cavities with finesses of about 30
for a diameter equal to 15 cm. Resonance linewidths of 3.2~MHz with contrasts
as large as 89\% are obtained. Comparison with 7-cell photonic band gap (PBG)
fiber leads to better finesse and contrast with Kagome fiber. Resonators based
on such fibers are compatible with the angular random walk required for medium
to high performance rotation sensing. The small amount of light propagating in
silica should also permit to further reduce the Kerr-induced non-reciprocity by
at least three orders of magnitudes in 7-cell Kagome fiber compared with 7-cell
PBG fiber.",1601.02899v2
2016-02-17,Confinement-Induced Resonances in Ultracold Atom-Ion Systems,"We investigate confinement-induced resonances in a system composed by a
tightly trapped ion and a moving atom in a waveguide. We determine the
conditions for the appearance of such resonances in a broad region -- from the
""long-wavelength"" limit to the opposite case when the typical length scale of
the atom-ion polarisation potential essentially exceeds the transverse
waveguide width. We find considerable dependence of the resonance position on
the atomic mass which, however, disappears in the ""long-wavelength and
zero-energy"" limit, where the known result for the confined atom-atom
scattering is reproduced. We also derive an analytic and a semi-analytic
formula for the resonance position in the ""long-wavelength and zero-energy""
limit and we investigate numerically how the position of the resonance is
affected by a finite atomic colliding energy. Our results, which can be
investigated experimentally in the near future, could be used to determine the
atom-ion scattering length, the temperature of the atomic ensemble in the
presence of an ion impurity, and to control the atom-phonon coupling in a
linear ion crystal in interaction with a quasi one dimensional atomic quantum
gas.",1602.05550v2
2016-02-18,A mystery of black-hole gravitational resonances,"More than three decades ago, Detweiler provided an analytical formula for the
gravitational resonant frequencies of rapidly-rotating Kerr black holes. In the
present work we shall discuss an important discrepancy between the famous {\it
analytical} prediction of Detweiler and the recent {\it numerical} results of
Zimmerman et. al. In addition, we shall refute the claim that recently appeared
in the physics literature that the Detweiler-Teukolsky-Press resonance equation
for the characteristic gravitational eigenfrequencies of rapidly-rotating Kerr
black holes is not valid in the regime of damped quasinormal resonances with
$\Im\omega/T_{\text{BH}}\gg1$ (here $\omega$ and $T_{\text{BH}}$ are
respectively the characteristic quasinormal resonant frequency of the Kerr
black hole and its Bekenstein-Hawking temperature). The main goal of the
present paper is to highlight and expose this important {\it black-hole
quasinormal mystery} (that is, the intriguing discrepancy between the
analytical and numerical results regarding the gravitational quasinormal
resonance spectra of rapidly-rotating Kerr black holes).",1602.05730v2
2016-03-10,Low-lying Resonances and Relativistic Screening in Big Bang Nucleosynthesis,"We explore effects of the screening due to the relativistic electron-positron
plasma and presence of resonances in the secondary reactions leading to A=7
nuclei during the Big Bang Nucleosynthesis. In particular, we investigate and
examine possible low-lying resonances in the $^7$Be($^3$He, $\gamma$)$^{10}$C
reaction and examine the resultant destruction of $^7$Be for various resonance
locations and strengths. While a resonance in the $^{10}$C compound nucleus is
thought to have negligible effects we explore the possibility of an enhancement
from plasma screening that may adjust the final $^7$Be abundance. We find the
effects of relativistic screening and possible low-lying resonances to be
relatively small in the standard Early Universe models.",1603.03137v3
2016-03-12,Evidence for Some New Hyperon Resonances -- to be Checked by $K_L$ Beam Experiments,"Quenched and unquenched quark models predict very different patterns for the
spectrum of the low excited hyperon states. Evidence is accumulating for the
existence of some new hyperon resonances, such as a $\Sigma^*$ of spin-parity
$J^P=1/2^-$ around 1400 MeV instead of 1620 MeV as listed in PDG, a new
$\Sigma(1540)3/2^-$ resonance, a new narrow $\Lambda(1670)3/2^-$ resonance and
a new $\Lambda(1680)3/2^+$ resonance. All these new hyperon resonances fit in
the predicted pattern of the unquenched quark models very well. It is extremely
important to check and establish the spectrum of these low excited hyperon
states by the proposed $K_L$ beam experiments at JLAB.",1603.03927v1
2016-03-15,Beam Induced Electron Cloud Resonances in Dipole Magnetic Fields,"The buildup of low energy electrons in an accelerator, known as electron
cloud, can be severely detrimental to machine performance. Under certain beam
conditions, the beam can become resonant with the cloud dynamics, accelerating
the buildup of electrons. This paper will examine two such effects:
multipacting resonances, in which the cloud development time is resonant with
the bunch spacing, and cyclotron resonances, in which the cyclotron period of
electrons in a magnetic field is a multiple of bunch spacing. Both resonances
have been studied directly in dipole fields using retarding field analyzers
installed in the Cornell Electron Storage Ring (CESR). These measurements are
supported by both analytical models and computer simulations.",1603.04817v2
2016-03-16,Resonance effects in the Raman scattering of mono- and few layers MoSe$_2$,"Using resonant Raman scattering spectroscopy with 25 different laser lines,
we describe the Raman scattering spectra of mono- and multi-layers
2H-molybdenum diselenide (MoSe$_2$) as well as the different resonances
affecting the most pronounced features. For high-energy phonons, both A- and E-
symmetry type phonons present resonances with A and B excitons of MoSe$_2$
together with a marked increase of intensity when exciting at higher energy,
close to the C exciton energy. We observe symmetry dependent exciton-phonon
coupling affecting mainly the low-energy rigid layer phonon modes. The shear
mode for multilayer displays a pronounced resonance with the C exciton while
the breathing mode has an intensity that grows with the excitation laser
energy, indicating a resonance with electronic excitations at energies higher
than that of the C exciton.",1603.05172v1
2016-03-22,Planetary and satellite three body mean motion resonances,"We propose a semianalytical method to compute the strengths on each of the
three massive bodies participating in a three body mean motion resonance (3BR).
  Applying this method we explore the dependence of the strength on the masses,
the orbital parameters and the order of the resonance and we compare with
previous studies. We confirm that for low eccentricity low inclination orbits
zero order resonances are the strongest ones; but for excited orbits higher
order 3BRs become also dynamically relevant. By means of numerical integrations
and the construction of dynamical maps we check some of the predictions of the
method. We numerically explore the possibility of a planetary system to be
trapped in a 3BR due to a migrating scenario. Our results suggest that capture
in a chain of two body resonances is more probable than a capture in a pure
3BR. When a system is locked in a 3BR and one of the planets is forced to
migrate the other two can react migrating in different directions. We exemplify
studying the case of the Galilean satellites where we show the relevance of the
different resonances acting on the three innermost satellites.",1603.06911v1
2016-03-24,Resonances for homoclinic trapped sets,"We study semiclassical resonances generated by homoclinic trapped sets.
First, under some general assumptions, we prove that there is no resonance in a
region below the real axis. Then, we obtain a quantization rule and the
asymptotic expansion of the resonances when there is a finite number of
homoclinic trajectories. The same kind of results is proved for homoclinic sets
of maximal dimension. Next, we generalize to the case of
homoclinic/heteroclinic trajectories and we study the three bump case. In all
these settings, the resonances may either accumulate on curves or form clouds.
We also describe the corresponding resonant states.",1603.07517v1
2016-03-29,Quantum and classical control of single photon states via a mechanical resonator,"Optomechanical systems typically use light to control the quantum state of a
mechanical resonator. In this paper, we propose a scheme for controlling the
quantum state of light using the mechanical degree of freedom as a controlled
beam splitter. Preparing the mechanical resonator in non-classical states
enables an optomechanical Stern-Gerlach interferometer. When the mechanical
resonator has a small coherent amplitude it acts as a quantum control,
entangling the optical and mechanical degrees of freedom. As the coherent
amplitude of the resonator increases, we recover single photon and two-photon
interference via a classically controlled beam splitter. The visibility of the
two-photon interference is particularly sensitive to coherent excitations in
the mechanical resonator and this could form the basis of an optically
transduced weak-force sensor.",1603.08613v2
2016-04-14,Production and Decay of Di-photon Resonance at Future $e^+e^-$ Colliders,"Motivated by the ATLAS and CMS announcements of the excesses of di-photon
events, we discuss the production and decay processes of di-photon resonance at
future $e^+e^-$ colliders. We assume that the excess of the di-photon events at
the LHC is explained by a scalar resonance decaying into a pair of photons. In
such a case, the scalar interacts with standard model gauge bosons and,
consequently, the production of such a scalar is possible at the $e^+e^-$
colliders. We study the production of the scalar resonance via the associated
production with photon or $Z$, as well as via the vector-boson fusion, and
calculate the cross sections of these processes. We also study the backgrounds,
and discuss the detectability of the signals of scalar production with various
decay processes of the scalar resonance. We also consider the case where the
scalar resonance has an invisible decay mode, and study how the invisible decay
can be observed at the $e^+e^-$ colliders.",1604.04076v1
2016-04-19,Resonance fluorescence and laser spectroscopy of three-dimensionally confined excitons in monolayer WSe$_2$,"Resonant optical excitation of few-level quantum systems enables coherent
quantum control, resonance fluorescence, and direct characterization of
dephasing mechanisms. Experimental demonstrations have been achieved in a
variety of atomic and solid-state systems. An alternative but intriguing
quantum photonic platform is based on single layer transition metal
chalcogenide semiconductors, which exhibit a direct band-gap with optically
addressable exciton valley-pseudospins in a uniquely two-dimensional form. Here
we perform resonance and near-resonance excitation of three-dimensionally
confined excitons in monolayer WSe$_2$ to reveal near ideal single photon
fluorescence with count rates up to 3 MHz and uncover a weakly-fluorescent
exciton state ~ 5 meV blue-shifted from the ground-state exciton. We perform
high-resolution photoluminescence excitation spectroscopy of the localized
excitons, providing important information to unravel the precise nature of the
quantum states. Successful demonstration of resonance fluorescence paves the
way to probe the localized exciton coherence. Moreover, these results yield a
route for investigations of the spin and valley coherence of confined excitons
in two-dimensional semiconductors.",1604.05522v1
2016-06-09,Signal-background interference for a singlet spin-0 digluon resonance at the LHC,"Dijet mass distributions can be used to search for spin-0 resonances that
couple to two gluons. I show that there is a substantial impact on such
searches from the interference between the resonant signal and the continuum
QCD background amplitudes. The signal dijet mass distribution is qualitatively
modified by this interference, compared to the naive expectation from
considering only the pure resonant contribution, even if the total width of the
resonance is minimal and very small compared to the experimental dijet mass
resolution. The impact becomes more drastic as the total width of the resonance
increases. These considerations are illustrated using examples relevant to the
750 GeV diphoton excess recently observed at the LHC.",1606.03026v5
2016-06-22,Hyperbolic Metamaterial Nano-Resonators Make Poor Single Photon Sources,"We study the optical properties of quantum dipole emitters coupled to
hyperbolic metamaterial nano-resonators using a semi-analytical quasinormal
mode approach. We show that coupling to metamaterial nano-resonators can lead
to significant Purcell enhancements that are nearly an order of magnitude
larger than those of plasmonic resonators with comparable geometry. However,
the associated single photon output $\beta$-factors are extremely low (around
10$\%$), far smaller than those of comparable sized metallic resonators
(70$\%$). Using a quasinormal mode expansion of the photon Green function, we
describe how the low $\beta$-factors are due to increased Ohmic quenching
arising from redshifted resonances, larger quality factors, and stronger
confinement of light within the metal. In contrast to current wisdom, these
results suggest that hyperbolic metamaterial nano-structures make poor choices
for single photon sources.",1606.06957v2
2016-06-26,Repeatable Room Temperature Negative Differential Conductance in GaN/AlN Resonant Tunneling Diodes,"Double barrier GaN/AlN resonant tunneling heterostructures have been grown by
molecular beam epitaxy on the (0001) plane of commercially available bulk GaN
substrates. Resonant tunneling diodes were fabricated; room temperature
current-voltage measurements reveal the presence of a negative differential
conductance region under forward bias with peak current densities of ~6.4
$kA/cm^2$ and a peak to valley current ratio of ~1.3. Reverse bias operation
presents a characteristic turn-on threshold voltage intimately linked to the
polarization fields present in the heterostructure. An analytic electrostatic
model is developed to capture the unique features of
polar-heterostructure-based resonant tunneling diodes; both the resonant and
threshold voltages are derived as a function of the design parameters and
polarization fields. Subsequent measurements confirm the repeatability of the
negative conductance and demonstrate that III-nitride tunneling
heterostructures are capable of robust resonant transport at room temperature.",1606.08100v1
2016-06-28,Single Spin Magnetic Resonance,"Different approaches have improved the sensitivity of either electron or
nuclear magnetic resonance to the single spin level. For optical detection it
has essentially become routine to observe a single electron spin or nuclear
spin. Typically, the systems in use are carefully designed to allow for single
spin detection and manipulation, and of those systems, diamond spin defects
rank very high, being so robust that they can be addressed, read out and
coherently controlled even under ambient conditions and in a versatile set of
nanostructures. This renders them as a new type of sensor, which has been shown
to detect single electron and nuclear spins among other quantities like force,
pressure and temperature. Adapting pulse sequences from classic NMR and EPR,
and combined with high resolution optical microscopy, proximity to the target
sample and nanoscale size, the diamond sensors have the potential to constitute
a new class of magnetic resonance detectors with single spin sensitivity. As
diamond sensors can be operated under ambient conditions, they offer potential
application across a multitude of disciplines. Here we review the different
existing techniques for magnetic resonance, with a focus on diamond defect spin
sensors, showing their potential as versatile sensors for ultra-sensitive
magnetic resonance with nanoscale spatial resolution.",1606.08830v1
2016-07-01,Dynamical strong coupling and parametric amplification in mechanical modes of graphene drums,"Mechanical resonators are ubiquitous in modern information technology. With
the ability to couple them to electromagnetic and plasmonic modes, they hold
the promise to be the key building blocks in future quantum information
technology. Graphene based resonators are of interest for technological
applications due to their high resonant frequencies, multiple mechanical modes,
and low mass. The tension mediated non-linear coupling between various modes of
the resonator can be excited in a controllable manner. Here, we engineer a
graphene resonator to have large frequency tunability at low temperatures
resulting in large intermodal coupling strength. We observe the emergence of
new eigenmodes and amplification of the coupled modes using red and blue
parametric excitation respectively. We demonstrate that the dynamical
intermodal coupling is tunable. A cooperativity of 60 between two resonant
modes of ~100 MHz is achieved in the strong coupling regime. The ability to
dynamically control the coupling between high frequency eigenmodes of a
mechanical system opens up possibility for quantum mechanical experiments at
low temperatures.",1607.00229v1
2016-07-11,Triple-resonant Brillouin light scattering in magneto-optical cavities,"An enhancement in Brillouin light scattering of optical photons with magnons
is demonstrated in magneto-optical whispering gallery mode resonators tuned to
a triple resonance point. This occurs when both the input and output optical
modes are resonant with those of the whispering gallery resonator, with a
separation given by the ferromagnetic resonance (FMR) frequency. The
identification and excitation of specific optical modes allows us to gain a
clear understanding of the mode-matching conditions. A selection rule due to
wavevector matching leads to an intrinsic single-sideband excitation. Strong
suppression of one sideband is essential for one-to-one frequency mapping in
coherent optical-to-microwave conversion.",1607.02985v2
2016-07-27,The orbital distribution of trans-Neptunian objects beyond 50 au,"The dynamical structure of the Kuiper belt beyond 50 au is not well
understood. Here we report results of a numerical model with long-range, slow
and grainy migration of Neptune. The model implies that bodies scattered
outward by Neptune to semimajor axes a>50 au often evolve into resonances which
subsequently act to raise the perihelion distances of orbits to q>40 au. The
implication of the model is that the orbits with 50<a<100 au and q>40 au should
cluster near (but not in) the resonances with Neptune (3:1 at a=62.6 au, 4:1 at
a=75.9 au, 5:1 at a=88.0 au, etc.). The recent detection of several distant
Kuiper Belt Objects (KBOs) near resonances is consistent with this prediction,
but it is not yet clear whether the orbits are really non-resonant as our model
predicts. We estimate from the model that there should presently be ~1600-2400
bodies at the 3:1 resonance and ~1000-1400 bodies at the 4:1 resonance (for
q>40 au and diameters D>100 km). These results favorably compare with the
population census of distant KBOs inferred from existing observations.",1607.08279v1
2016-09-09,Energy localization enhanced ground-state cooling of mechanical resonator from room temperature in optomechanics using a gain cavity,"When a gain system is coupled to a loss system, the energy usually flows from
the gain system to the loss one. We here present a counterintuitive theory for
the ground-state cooling of the mechanical resonator in optomechanical system
via a gain cavity. The energy flows first from the mechanical resonator into
the loss cavity, then into the gain cavity, and finally localizes there. The
energy localization in the gain cavity dramatically enhances the cooling rate
of the mechanical resonator. Moreover, we show that unconventional optical
spring effect, e.g., giant frequency shift and optically induced damping of the
mechanical resonator, can be realized. Those feature a pre-cooling free
ground-state cooling, i.e., the mechanical resonator in thermal excitation at
room temperature can directly be cooled to its ground state. This cooling
approach has the potential application for fundamental tests of quantum physics
without complicated cryogenic setups.",1609.02722v2
2016-10-07,Double Resonance in Dalitz Plot of M(pLambda)-M(KLambda) in DISTO Data on p+p rightarrow p+Lambda+K+ at 2.85 GeV,"The X(2265) resonance was previously observed in DISTO data of p+p rightarrow
p+Lambda+K+ at 2.85 GeV on an attempt of searching for the kaonic nuclear state
K-pp rightarrow p + Lambda. In the present paper we report an additional
finding, namely, a double resonance type phenomena, not only with a peak at
M(pLambda) = 2265 MeV/c2 but also a broad bump at M(K+ Lambda) ~ 1700 MeV/c2.
This ""double-resonance"" zone is expressed as XY(2265, 1700). The latter bump
may result from nearby nucleon resonances, typically N*(1710), as well as by
attractive K - Lambda final-state interaction. We point out that this double
resonance XY(2265, 1700) as seen in DISTO at 2.85 GeV cannot be populated
kinematically in a HADES experiment at 3.5 GeV.",1610.02148v1
2016-10-11,Guidelines for designing 2D and 3D plasmonic stub resonators,"In this work, we compare the performance of plasmonic waveguide integrated
stub resonators based on 2D metal-dielectric-metal and 3D slot waveguide (SWG)
geometries. We show that scattering matrix theory can be extended to 3D
devices, and by employing scattering matrix theory, we provide the guidelines
for designing plasmonic 2D and 3D single-stub and double-stub resonators with a
desired spectral response at the design wavelength. We provide transmission
maps of 2D and 3D double-stub resonators versus stub lengths, and we specify
the different regions on these maps that result in a minimum, a maximum, or a
plasmonically induced transparency shape in the transmission spectrum.
Radiation loss from waveguide terminations leads to a degradation of the 3D
SWG-based resonators. We illustrate improved waveguide terminations that boost
resonator properties. We verify our results with 3D finite-difference
time-domain (FDTD) simulations.",1610.03280v2
2016-10-25,Isotopic shift of atom-dimer Efimov resonances in K-Rb mixtures: Critical effect of multichannel Feshbach physics,"The multichannel Efimov physics is investigated in ultracold heteronuclear
admixtures of K and Rb atoms. We observe a shift in the scattering length where
the first atom-dimer resonance appears in the $^{41}$K-$^{87}$Rb system
relative to the position of the previously observed atom-dimer resonance in the
$^{40}$K-$^{87}$Rb system. This shift is well explained by our calculations
with a three-body model including the van der Waals interactions, and, more
importantly, the multichannel spinor physics. With only minor difference in the
atomic masses of the admixtures, the shift in the atom-dimer resonance
positions can be cleanly ascribed to the isolated and overlapping Feshbach
resonances in the $^{40}$K-$^{87}$Rb and $^{41}$K-$^{87}$Rb systems,
respectively. Our study demonstrates the role of the multichannel Feshbach
physics in determining Efimov resonances in heteronuclear three-body systems.",1610.07900v2
2017-02-22,Microplasma generation by slow microwave in an electromagnetically induced transparency-like metasurface,"Microplasma generation using microwaves in an electromagnetically induced
transparency (EIT)-like metasurface composed of two types of radiatively
coupled cut-wire resonators with slightly different resonance frequencies is
investigated. Microplasma is generated in either of the gaps of the cut-wire
resonators as a result of strong enhancement of the local electric field
associated with resonance and slow microwave effect. The threshold microwave
power for plasma ignition is found to reach a minimum at the EIT-like
transmission peak frequency, where the group index is maximized. A pump-probe
measurement of the metasurface reveals that the transmission properties can be
significantly varied by varying the properties of the generated microplasma
near the EIT-like transmission peak frequency and the resonance frequency. The
electron density of the microplasma is roughly estimated to be of order
$1\times 10^{10}\,\mathrm{cm}^{-3}$ for a pump power of $15.8\,\mathrm{W}$ by
comparing the measured transmission spectrum for the probe wave with the
numerically calculated spectrum. In the calculation, we assumed that the plasma
is uniformly generated in the resonator gap, that the electron temperature is
$2\,\mathrm{eV}$, and that the elastic scattering cross section is $20 \times
10^{-16}\,\mathrm{cm}^2$.",1702.06750v1
2017-02-28,Graph-Facilitated Resonant Mode Counting in Stochastic Interaction Networks,"Oscillations in a stochastic dynamical system, whose deterministic
counterpart has a stable steady state, are a widely reported phenomenon.
Traditional methods of finding parameter regimes for stochastically-driven
resonances are, however, cumbersome for any but the smallest networks. In this
letter we show by example of the Brusselator how to use real root counting
algorithms and graph theoretic tools to efficiently determine the number of
resonant modes and parameter ranges for stochastic oscillations. We argue that
stochastic resonance is a network property by showing that resonant modes only
depend on the squared Jacobian matrix $J^2$ , unlike deterministic oscillations
which are determined by $J$. By using graph theoretic tools, analysis of
stochastic behaviour for larger networks is simplified and chemical reaction
networks with multiple resonant modes can be identified easily.",1702.08747v1
2018-02-22,Electric quadrupole and magnetic dipole coupling in plasmonic nanoparticle arrays,"Collective resonances in plasmonic nanoparticle arrays with electric dipole
moment oriented along the lattice wave propagation are theoretically
investigated. The role of electric quadrupole (EQ) and magnetic dipole (MD)
moments of gold nanoparticles in the resonant features of the arrays is
analyzed. We perform both semi-analytical calculations of coupled multipole
equations and rigorous numerical simulations varying contributions of the
electric and magnetic multipoles by changing particle size and shape (spheres
and disks). The arrays in homogeneous and non-homogeneous environments are
considered. We find that even very weak non-resonant EQ and MD moments of a
single particle are significantly enhanced in the periodic lattice at the
wavelength of collective (lattice) resonance excitation. Importantly, we show
that in the infinite arrays, the EQ and MD moments of nanoparticles are coupled
and affect each other resonant contributions. We also demonstrate that at the
lattice-resonance wavelength, the enhanced EQ and MD moments have contributions
to reflection comparable to the dipole one resulting in a significant decrease
of reflection and providing the satisfaction of the generalized Kerker
condition for reflection suppression.",1802.07960v1
2018-02-28,Tunable sub-gap radiation detection with superconducting resonators,"We have fabricated planar amorphous Indium Oxide superconducting resonators
($T_c\sim2.8$ K) that are sensitive to frequency-selective radiation in the
range of 7 to 10 GHz. Those values lay far below twice the superconducting gap
that worths about 200 GHz. The photons detection consists in a shift of the
fundamental resonance frequency. We show that the detected frequency can be
adjusted by modulating the total length of the superconducting resonator. We
attribute those observations to the excitation of higher-order resonance modes.
The coupling between the fundamental lumped and the higher order distributed
resonance is due to the kinetic inductance non-linearity with current. These
devices, that we have called Sub-gap Kinetic Inductance Detectors (SKIDs), are
to be distinguished from the standard Kinetic Inductance Detectors (KIDs) in
which quasi-particles are generated when incident light breaks down Cooper
pairs.",1802.10379v1
2018-02-28,Deterministic transfer of an unknown qutrit state assisted by the low-Q microwave resonators,"Qutrits (i.e., three-level quantum systems) can be used to achieve many
quantum information and communication tasks due to their large Hilbert spaces.
In this work, we propose a scheme to transfer an unknown quantum state between
two flux qutrits coupled to two superconducting coplanar waveguide resonators.
The quantum state transfer can be deterministically achieved without
measurements. Because resonator photons are virtually excited during the
operation time, the decoherences caused by the resonator decay and the unwanted
inter-resonator crosstalk are greatly suppressed. Moreover, our approach can be
adapted to other solid-state qutrits coupled to circuit resonators. Numerical
simulations show that the high-fidelity transfer of quantum state between the
two qutrits is feasible with current circuit QED technology.",1802.10387v1
2018-04-10,Microwave cavity tuned with liquid metal and its application to Electron Paramagnetic Resonance,"This note presents a method to tune the resonant frequency $f_{0}$ of a
rectangular microwave cavity. This is achieved using a liquid metal, GaInSn, to
decrease the volume of the cavity. It is possible to shift $f_{0}$ by filling
the cavity with this alloy, in order to reduce the relative distance between
the internal walls. The resulting modes have resonant frequencies in the range
$7\div8\,$GHz. The capability of the system of producing an Electron
Paramagnetic Resonance (EPR) measurement has been tested by placing a 1 mm
diameter Yttrium Iron Garnet (YIG) sphere inside the cavity, and producing a
strong coupling between the cavity resonance and Kittel mode. This work shows
the possibility to tune a resonant system in the GHz range, which can be useful
for several applications.",1804.03443v1
2018-04-10,Role of intra-band transitions in photo-carrier generation,"We theoretically investigate the role of intra-band transitions in
laser-induced carrier-generation for different photon energy regimes: (i)
strongly off-resonant, (ii) multi-photon resonant, and (iii) resonant
conditions. Based on the analysis for the strongly off-resonant and
multi-photon resonant cases, we find that intra-band transitions strongly
enhance photo-carrier generation in both multi-photon absorption and tunneling
excitation regimes, and thus, they are indispensable for describing the
nonlinear photo-carrier generation processes. Furthermore, we find that
intra-band transitions enhance photo-carrier generation even in the resonant
condition, opening additional multi-photon excitation channels once the laser
irradiation becomes sufficiently strong. The above findings suggest a potential
for efficient control of photo-carrier generation via multi-color laser pulses
through optimization of the contributions from intra-band transitions.",1804.03678v1
2018-04-11,Simultaneous cooling of coupled mechanical resonators in cavity optomechanics,"Quantum manipulation of coupled mechanical resonators has become an important
research topic in optomechanics because these systems can be used to study the
quantum coherence effects involving multiple mechanical modes. A prerequisite
for observing macroscopic mechanical coherence is to cool the mechanical
resonators to their ground state. Here we propose a theoretical scheme to cool
two coupled mechanical resonators by introducing an optomechanical interface.
The final mean phonon numbers in the two mechanical resonators are calculated
exactly and the results show that the ground-state cooling is achievable in the
resolved-sideband regime and under the optimal driving. By adiabatically
eliminating the cavity field in the large-decay regime, we obtain analytical
results of the cooling limits, which show the smallest achievable phonon
numbers and the parameter conditions under which the optimal cooling is
achieved. Finally, the scheme is extended to the cooling of a chain of coupled
mechanical resonators.",1804.04026v1
2018-04-22,Resonant Hamiltonian systems associated to the one-dimensional nonlinear Schrödinger equation with harmonic trapping,"We study two resonant Hamiltonian systems on the phase space $L^2(\mathbb{R}
\rightarrow \mathbb{C})$: the quintic one-dimensional continuous resonant
equation, and a cubic resonant system that has appeared in the literature as a
modified scattering limit for an NLS equation with cigar shaped trap. We prove
that these systems approximate the dynamics of the quintic and cubic
one-dimensional NLS with harmonic trapping in the small data regime on long
times scales. We then pursue a thorough study of the dynamics of the resonant
systems themselves. Our central finding is that these resonant equations fit
into a larger class of Hamiltonian systems that have many striking dynamical
features: non-trivial symmetries such as invariance under the Fourier transform
and the flow of the linear Scr\""odinger equation with harmonic trapping, a
robust wellposedness theory, including global wellposedness in $L^2$ and all
higher $L^2$ Sobolev spaces, and an infinite family of orthogonal, explicit
stationary wave solutions in the form of the Hermite functions.",1804.08190v1
2018-11-02,A resonance interaction of seismogravitational modes on tectonic plates,"This paper discusses resonance effects to advance a classical earthquake
model, namely the celebrated M8 global test algorithm. This algorithmgives high
confidence levels for prediction of Time Intervals of Increased Probability
(TIP) of an earthquake. It is based on observation that almost 80\% of
earthquakes occur due to the stress accumulated from previous earthquakes at
the location and stored in form of displacements against gravity and static
elastic deformations of the plates. Nevertheless the M8 global test algorithm
fails to predict some powerful earthquakes. In this paper we suggest the
additional possibility of considering the dynamical storage of the elastic
energy on the tectonic plates due to resonance beats of seismo-gravitational
oscillations (SGO) modes of the plates. We make sure that the tangential
compression in the middle plane of an ""active zone"" of a tectonic plate may
tune its SGO modes to the resonance condition of coincidence the frequencies of
the corresponding localized modes with the delocalized SGO modes of the
complement. We also consider the beats arising between the modes under a small
perturbations of the plates, and, assuming that the discord between the
perturbed and unperturbed resonance modes is strongly dominated by the discord
between the non-resonance modes estimate the energy transfer coefficient.",1811.00721v1
2018-11-04,Using split-ring resonators to measure the electromagnetic properties of materials: An experiment for senior physics undergraduates,"A spilt-ring resonator experiment suitable for senior physics undergraduates
is described and demonstrated in detail. The apparatus consists of a conducting
hollow cylinder with a narrow slit along its length and can be accurately
modelled as a series $LRC$ circuit. The resonance frequency and quality factor
of the split-ring resonator are measured when the apparatus is suspended in
air, submerged in water, and submerged in an aqueous solution of various
concentrations of NaCl. The experimental results are used to extract the
dielectric constant of water and to investigate the dependence of the resonator
quality factor on the conductivity of the NaCl solution. The apparatus provides
opportunities to experimentally examine radiative losses, complex permittivity,
the electromagnetic skin depth, and cutoff frequencies of rf propagation in
cylindrical waveguides, which are all concepts introduced in an undergraduate
course in electrodynamics. To connect with current research, the use of
split-ring resonators as a tool to precisely measure the electromagnetic
properties of materials is emphasized",1811.01449v1
2018-11-08,Quasistatic oscillations in subwavelength particles: Can one observe energy eigenstates?,"In increasing the capabilities of the optical and microwave techniques
further into the subwavelength regime, quasistatic resonant structures has
attracted considerable interest. Electromagnetic responses of electrostatic
(ES) plasmon resonances in optics and magnetostatic (MS) magnon resonances in
microwaves give rise to a strong enhancement of local fields near the surfaces
of subwavelength particles. In the near-field regions of subwavelength
particles one can only measure the electric or the magnetic field with
accuracy. Such uncertainty in definition of the electric or magnetic field
components raises the question of energy eigenstates of quasistatic
oscillations. The energy eigenstate problem can be properly formulated when
potential functions, used in the quasistatic-resonance problems, are introduced
as scalar wave functions. In this case, one should observe quasistatic-wave
retardation effects still staying in frames of the quasistatic description of
oscillations in a subwavelength particle. In this paper, we analyze the problem
of energy quantization of ES resonances in subwavelength optical metallic
structures with plasmon oscillations and MS resonances in subwavelength
microwave ferrite particles with magnon oscillations. We show that in a case of
MS-potential scalar wave function one can observe quasistatic retardation
effects and obtain a proper formulation of the energy eigenstate problem.",1811.03314v1
2018-11-09,Microwave cavity detected spin blockade in a few electron double quantum dot,"We investigate spin states of few electrons in a double quantum dot by
coupling them weakly to a magnetic field resilient NbTiN microwave resonator.
We observe a reduced resonator transmission if resonator photons and spin
singlet states interact. This response vanishes in a magnetic field once the
quantum dot ground state changes from a spin singlet into a spin triplet state.
Based on this observation, we map the two-electron singlet-triplet crossover by
resonant spectroscopy. By measuring the resonator only, we observe Pauli spin
blockade known from transport experiments at finite source-drain bias and
detect an unconventional spin blockade triggered by the absorption of resonator
photons.",1811.03907v1
2018-11-28,Quasinormal mode solvers for resonators with dispersive materials,"Optical resonators are widely used in modern photonics. Their spectral
response and temporal dynamics are fundamentally driven by their natural
resonances, the so-called quasinormal modes (QNMs), with complex frequencies.
For optical resonators made of dispersive materials, the QNM computation
requires solving a nonlinear eigenvalue problem. This rises a difficulty that
is only scarcely documented in the literature. We review our recent efforts for
implementing efficient and accurate QNM-solvers for computing and normalizing
the QNMs of micro- and nano-resonators made of highly-dispersive materials. We
benchmark several methods for three geometries, a two-dimensional plasmonic
crystal, a two-dimensional metal grating, and a three-dimensional nanopatch
antenna on a metal substrate, in the perspective to elaborate standards for the
computation of resonance modes.",1811.11751v1
2019-05-05,Controlling Fano resonance using the Geometrical Phase of light in spatially tailored waveguided plasmonic crystals,"Fano resonance exhibiting an asymmetric spectral line shape is a universal
phenomenon observed in diverse physical systems. Here we experimentally
establish a direct link between the spectral asymmetry parameter and a
physically realizable phase factor of interference between a continuum and a
discrete mode that leads to Fano resonance. Using a specially designed
metamaterial, namely waveguided plasmonic crystal with a spatially varying
orientation axis of plasmonic grating, we demonstrate control on the spectral
asymmetry of the Fano resonance through changes in the geometric phase of
polarized light. In this scenario, the changes in the geometric phase for input
left, and right circular polarized light arises due to varying orientation
angle of the grating axis. The systematic changes in the geometric phase and
the resulting q-parameter of Fano resonance is interpreted by an appropriate
theoretical model connecting the two physical entities. The demonstrated
control over the spectral line shape of Fano resonance achieved by tailoring
geometric phase may open up novel routes for polarization-based photonic
applications.",1905.01636v1
2019-05-07,Resonant state expansion applied to one-dimensional quantum systems,"The resonant state expansion, a rigorous perturbation theory, recently
developed in electrodynamics, is applied to non-relativistic quantum mechanical
systems in one dimension. The method is used here for finding the resonant
states in various potentials approximated by combinations of Dirac delta
functions. The resonant state expansion is first verified for a triple quantum
well system, showing convergence to the available analytic solution as the
number of resonant states in the basis increases. The method is then applied to
multiple quantum well and barrier structures, including finite periodic
systems. Results are compared with the eigenstates in triple quantum wells and
infinite periodic potentials, revealing the nature of the resonant states in
the studied systems.",1905.02643v1
2019-05-15,A plasmonic ellipse resonator possessing hybrid modes for ultracompact chipscale application,"We propose a plasmonic ellipse resonator possessing hybrid modes based on
metal-insulator-metal (MIM) waveguide system. Specially, this nanocavity has
hybrid characteristic of rectangle and disk resonator, therefore supporting
both Fabry-Perot modes (FPMs) and whispering-gallery modes (WGMs). Besides, by
changing the length of major and minor radius of the ellipse, the resonant
wavelengths of FPMs and WGMs can be independently tuned and close to each
other, thus constructing a plasmon-induced transparency (PIT) - like spectrum
profile. Benefitting from this, a dual-band slow light is achieved with one
single resonator. Furthermore, this component can also act as a multi-band
color filter and refractive index sensor. We believe such multi-mode resonator
with ultra-small footprint will play an important role in more compact on-chip
optical circuits in the future.",1905.06120v1
2019-05-27,Dissociation dynamics in the dissociative electron attachment to ammonia molecule,"Complete dissociation dynamics of low energy electron attachment to ammonia
molecule has been studied using velocity slice imaging (VSI) spectrometer. One
low energy resonant peak around 5.5 eV and a broad resonance around 10.5 eV
incident electron energy has been observed. The resonant states mainly
dissociate via H$^-$ and NH$_2^-$ fragments, though for the upper resonant
state, signature of NH$^-$ fragments are also predicted due to three body
dissociation process. Kinetic energy and angular distributions of the NH$_2^-$
fragment anions are measured simultaneously using VSI technique. Based on our
experimental observations, we find the signature of A$_1$ symmetry in the 10.5
eV resonance energy whereas, the 5.5 eV resonance is associated with the well
known A$_1$ symmetry.",1905.10993v1
2019-05-28,Magnetic Feshbach resonances in ultracold collisions between Cs and Yb atoms,"We investigate magnetically tunable Feshbach resonances in ultracold
collisions between ground-state Yb and Cs atoms, using coupled-channel
calculations based on an interaction potential recently determined from
photoassociation spectroscopy. We predict resonance positions and widths for
all stable isotopes of Yb, together with resonance decay parameters where
appropriate. The resonance patterns are richer and more complicated for
fermionic Yb than for spin-zero isotopes, because there are additional level
splittings and couplings due to scalar and tensorial Yb hyperfine interactions.
We examine collisions involving Cs atoms in a variety of hyperfine states, and
identify resonances that appear most promising for experimental observation and
for magnetoassociation to form ultracold CsYb molecules.",1905.11977v1
2019-05-29,Independent-subsystem interpretation of the double photoionization of pyrene and coronene,"It is shown that the M$^{2+}$ ion yield in the double photoionization of the
aromatic hydrocarbons, pyrene and coronene, can be expressed as a superposition
of a contribution from a resonance involving carbon atoms on the perimeter and
coherent contributions from carbon atoms inside the perimeter. In the case of
pyrene, the two interior atoms are associated with a resonance peak at 10 eV
and linear behavior above 75 eV. The resonance peak is an optically excited
state of the interior carbon pair. The linear behavior arises from the coherent
emission of two electrons with equal energy and opposite momenta, as occurs in
pyrrole. Coronene has a low energy peak along with two pairing resonances,
however, the linear region as in the case of pyrene is absent. The low energy
resonance is associated with the atoms on the perimeter and the high energy
resonance is associated with the hexagonal array of six carbon atoms at the
center of the molecule. It is proposed that the quasi-independence of the
contributions from the perimeter and interior atoms is related to H\""uckel's
Rule for the stability of aromatic hydrocarbons.",1905.12772v2
2020-07-04,Ultra-high Sensitive Surface Plasmon Resonance Based Sensor with Dual Resonance,"We show that for the optimized angle of incidence, the SPR based optical
sensors exhibit dual resonance in the near-infrared region around which the
sensor becomes exceptionally high sensitive. Both the resonances show opposite
spectral shift with an ambient refractive index, increasing the differential
shift by many folds. The physical reason behind the dual resonance and opposite
spectral shifts are also explained using the modal analysis and the
phase-matching condition. The presence of dual resonance is highly susceptible
to the angle of incidence, which facilitates the sensors to work in a wide
range from gaseous specimen to biological ones with extremely high sensitivity
of 460 um/RIU and 290 um/RIU, respectively. The considered sensor has broader
prospects for the detection of bio-chemicals and gases without changing its
geometrical parameters.",2007.02039v1
2020-07-07,Correlated Energy Uncertainties in Reaction Rate Calculations,"Context. Monte Carlo methods can be used to evaluate the uncertainty of a
reaction rate that arises from many uncertain nuclear inputs. However, until
now no attempt has been made to find the effect of correlated energy
uncertainties in input resonance parameters.
  Aims. To investigate the impact of correlated energy uncertainties on
reaction rates.
  Methods. Using a combination of numerical and Monte Carlo variation of
resonance energies, the effect of correlations are investigated. Five reactions
are considered: two fictional, illustrative cases and three reactions whose
rates are of current interest.
  Results. The effect of correlations in resonance energies depends on the
specific reaction cross section and temperatures considered. When several
resonances contribute equally to a reaction rate, and are located either side
of the Gamow peak, correlations between their energies dilute their effect on
reaction rate uncertainties. If they are both located above or below the
maximum of the Gamow peak, however, correlations between their resonance
energies can increase the reaction rate uncertainties. This effect can be hard
to predict for complex reactions with wide and narrow resonances contributing
to the reaction rate.",2007.03802v1
2020-07-09,Resonator-assisted single molecule quantum state detection,"We propose a state-sensitive scheme to optically detect a single molecule
without a closed transition, through strong coupling to a high-Q
whispering-gallery mode high-Q resonator. A background-free signal can be
obtained by detecting a molecule-induced transparency in a photon bus waveguide
that is critically coupled to the resonator, with a suppressed depumping rate
to other molecular states by the cooperativity parameter $C$. We numerically
calculate the dynamics of the molecule-resonator coupled system using Lindblad
master equations, and develop analytical solutions through the evolution of
quasi-steady states in the weak-driving regime. Using Rb$_2$ triplet ground
state molecules as an example, we show that high fidelity state readout can be
achieved using realistic resonator parameters. We further discuss the case of
multiple molecules collectively coupled to a resonator, demonstrating
near-unity detection fidelity and negligible population loss.",2007.04498v2
2020-07-17,Giant resonant enhancement of optical binding of dielectric disks,"Two-parametric variation over the aspect ratio of each disk and distance
between disks gives rise to numerous events of avoided crossing of resonances
of individual disks. For these events the hybridized anti-bonding resonant
modes can acquire a morphology close to the Mie resonant mode with high orbital
momentum of equivalent sphere. The $Q$ factor of such resonance can exceed the
$Q$ factor of isolated disk by two orders in magnitude. We show that dual
incoherent counter propagating coaxial Bessel beams with power $1mW/\mu m^2$
with frequency resonant to such a anti-bonding modes result in unprecedented
optical binding forces up to decades of nano Newtons for silicon micron size
disks. We show also that a magnitude and sign of optical forces strongly depend
on the longitudinal wave vector of the Bessel beams.",2007.08721v1
2020-07-17,A nonlinear magnonic nano-ring resonator,"The field of magnonics, which aims at using spin waves as carriers in data
processing devices, has attracted increasing interest in recent years. We
present and study micromagnetically a nonlinear nanoscale magnonic ring
resonator device for enabling implementations of magnonic logic gates and
neuromorphic magnonic circuits. In the linear regime, this device efficiently
suppresses spin-wave transmission using the phenomenon of critical resonant
coupling, thus exhibiting the behavior of a notch filter. By increasing the
spin-wave input power, the resonance frequency is shifted leading to
transmission curves, depending on the frequency, reminiscent of the activation
functions of neurons or showing the characteristics of a power limiter. An
analytical theory is developed to describe the transmission curve of magnonic
ring resonators in the linear and nonlinear regimes and validated by a
comprehensive micromagnetic study. The proposed magnonic ring resonator
provides a multi-functional nonlinear building block for unconventional
magnonic circuits.",2007.09205v2
2020-07-26,Unveiling shape resonances in H + HF collisions at cold energies,"Resonances are associated with the trapping of an intermolecular complex, and
are characterized by a series of quantum numbers such as the total angular
momentum and the parity, representative of a specific partial wave. Here we
show how at cold temperatures the rotational quenching of HF(j=1,2) with H is
strongly influenced by the presence of manifolds of resonances arising from the
combination of a single value of the orbital angular momentum with different
total angular momentum values. These resonances give rise up to a two-fold
increase in the thermal rate coefficient at the low temperatures characteristic
of the interstellar medium. Our results show that by selecting the relative
geometry of the reactants by alignment of the HF rotational angular momentum,
it is possible to decompose the resonance peak, disentangling the contribution
of different total angular momenta to the resonance.",2007.13088v1
2020-07-28,Ruelle-Taylor resonances of Anosov actions,"Combining microlocal methods and a cohomological theory developped by J.
Taylor, we define for $\mathbb{R}^\kappa$-Anosov actions a notion of joint
Ruelle resonance spectrum. We prove that these Ruelle-Taylor resonances fit
into a Fredholm theory, are intrinsic and form a discrete subset of
$\mathbb{C}^\kappa$, with $\lambda=0$ being always a leading resonance. The
joint resonant states at $0$ give rise to some new measures of SRB type and the
mixing properties of these measures are related to the existence of purely
imaginary resonances. The spectral theory developed in this article applies in
particular to the case of Weyl chamber flows and provides a new way to study
such flows.",2007.14275v5
2010-05-03,$ρN$ resonance dynamics in the proton nucleus reaction,"The strong coupling of rho meson to the nucleon produces $s$ and $p$ wave rho
meson nucleon $(\rho N)$ resonances. In a nucleus, the $\rho N$ resonance-hole
polarization generates the optical potential or self-energy for the rho meson.
The scattering of rho meson due to this potential provides valuable
informations about the $\rho N$ resonance dynamics in a nucleus. To investigate
it, we use this potential to calculate the mass distribution spectrum for the
$\rho$ meson produced coherently in the proton nucleus reaction. The cross
sections arising due to $s$ and $p$ wave $\rho N$ resonances have been
presented. The coherent and incoherent contributions to the cross sections due
to these resonances are compared. In addition, the calculated results due to
non-relativistic and relativistic $\rho$ meson self-energy are illustrated.",1005.0187v2
2010-05-31,More on volume dependence of spectral weight function,"Spectral weight functions are easily obtained from two-point correlation
functions and they might be used to distinguish single-particle from
multi-particle states in a finite-volume lattice calculation, a problem crucial
for many lattice QCD simulations. In previous studies, it is shown that the
spectral weight function for a broad resonance shares the typical volume
dependence of a two-particle scattering state i.e. proportional to $1/L^3$ in a
large cubic box of size $L$ while the narrow resonance case requires further
investigation. In this paper, a generalized formula is found for the spectral
weight function which incorporates both narrow and broad resonance cases.
Within L\""uscher's formalism, it is shown that the volume dependence of the
spectral weight function exhibits a single-particle behavior for a extremely
narrow resonance and a two-particle behavior for a broad resonance. The
corresponding formulas for both $A^+_1$ and $T^-_1$ channels are derived. The
potential application of these formulas in the extraction of resonance
parameters are also discussed.",1005.5571v1
2013-08-01,Controlling magnetic Feshbach resonances in polar open-shell molecules with non-resonant light,"Magnetically tunable Feshbach resonances for polar paramagnetic ground-state
diatomics are too narrow to allow for magnetoassociation starting from trapped,
ultracold atoms. We show that non-resonant light can be used to engineer the
Feshbach resonances in their position and width. For non-resonant field
strengths of the order of $10^9\,$W/cm$^2$, we find the width to be increased
by three orders of magnitude, reaching a few Gauss. This opens the way for
producing ultracold molecules with sizeable electric and magnetic dipole
moments and thus for many-body quantum simulations with such particles.",1308.0078v3
2013-08-03,Analytical model of overlapping Feshbach resonances,"Feshbach resonances in ultracold collisions often result from an interplay
between many collision channels. Simple two-channel models can be introduced to
capture the basic features, but cannot fully reproduce the situation when
several resonances from different closed channels contribute to the scattering
process. Using the formalism of multichannel quantum defect theory we develop
an analytical model of overlapping Feshbach resonances. We find a general
formula for the variation of the scattering length with magnetic field in the
vicinity of an arbitrary number of resonances, characterized by simple
parameters. Our formula is in excellent agreement with numerical coupled
channels calculations for several cases of overlapping resonances in the
collisions of two $^7$Li atoms or two Cs atoms.",1308.0681v1
2013-08-11,Experimental characterization of an uniaxial angle cut whispering gallery mode resonator,"The usual configuration of uniaxial whispering gallery mode resonators is a
disk shaped geometry where the optic axis points along the symmetry axis, a so
called z-cut resonator. Recently x-cut resonators, where the optic axis lies in
the equatorial plane, became of interest as they enable extremely broadband
second harmonic generation. In this paper we report on the properties of a more
generalized system, the so called angle-cut resonator, where the optic axis
exhibits an arbitrary angle against the symmetry axis. We show experimentally
that the modal structure and quality factors are similar to common resonators
but that the polarization properties differ quite significantly: due to the
asymmetry the polarization depends on the equatorial position and is, in
general, elliptical.",1308.2429v1
2014-03-11,On the disputed $π_1(1600)$ resonance and observation of a new iso-vector resonance,"The COMPASS experiment at CERN delivers new results on the search for exotic
mesons. A spin-exotic resonance, the $\pi_1(1600)$, was reported by several
experiments in the past. Those observations are, however, still to date highly
disputed in the community. Especially the $\rho\pi$ decay channel allows for
simultaneous observation of well established and less known resonances in
different decay modes. The results from amplitude analysis of diffractively
produced $(3\pi)^{-}$ final states show consistently a spin-exotic signal, that
appears in agreement with previous observations of the $\pi_1(1600)$. The
high-statistics 2008 data sample allows and demands for an extended amplitude
analysis method that further disentangles resonant and non-resonant particle
production. The present status of analysis of COMPASS data and the observation
of a new iso-vector meson $a_1(1420)$ is discussed.",1403.2667v1
2014-03-28,Resonance chains and geometric limits on Schottky surfaces,"Resonance chains have been observed in many different physical and
mathematical scattering problems. Recently numerical studies linked the
phenomenon of resonances chains to an approximate clustering of the length
spectrum on integer multiples of a base length. A canonical example of such a
scattering system is provided by 3-funneled hyperbolic surfaces where the
lengths of the three geodesics around the funnels have rational ratios. In this
article we present a mathematical rigorous study of the resonance chains for
these systems. We prove the analyticity of the generalized zeta function which
provide the central mathematical tool for understanding the resonance chains.
Furthermore we prove for a fixed ratio between the fun- nel lengths and in the
limit of large lengths that after a suitable rescaling, the resonances in a
bounded domain align equidistantly along certain lines. The position of these
lines is given by the zeros of an explicit polynomial which only depends on the
ratio of the funnel lengths.",1403.7419v1
2016-11-04,Fiber ring resonator with nanofiber section for chiral cavity quantum electrodynamics and multimode strong coupling,"We experimentally realize an optical fiber ring resonator that includes a
tapered section with subwavelength-diameter waist. In this section, the guided
light exhibits a significant evanescent field which allows for efficient
interfacing with optical emitters. A commercial tunable fiber beam splitter
provides simple and robust coupling to the resonator. Key parameters of the
resonator such as its out-coupling rate, free spectral range, and birefringence
can be adjusted. Thanks to the low taper- and coupling-losses, the resonator
exhibits an unloaded finesse of F=75+/-1, sufficient for reaching the regime of
strong coupling for emitters placed in the evanescent field. The system is
ideally suited for trapping ensembles of laser-cooled atoms along the nanofiber
section. Based on measured parameters, we estimate that the system can serve as
a platform for optical multimode strong coupling experiments. Finally, we
discuss the possibilities of using the resonator for applications based on
chiral quantum optics.",1611.01454v1
2016-11-10,An inverted crossover resonance within one Zeeman manifold,"We carry out investigations of inverted crossover resonances in $\pi$-driven
four-level systems where $\Delta F$ can be zero. Through the use of sub-Doppler
frequency modulation spectroscopy of the $(6s^{2})$ $^{1}S_{0}$ $-$ $(6s6p)$
$^{3}P_{1}$ transition in $^{171}$Yb the resonance becomes manifest. The
centre-frequency is inherently insensitive to first-order Zeeman shifts and
equates to the two-level resonance frequency in the absence of a magnetic
field. A rate equation model is used to help validate the nature of the
resonance. Optical frequency measurements of the $F'=1/2$ hyperfine line
recorded over two months demonstrate a statistical uncertainty of
$2\times10^{-11}$. The inverted crossover resonance found with the $F'=3/2$
line is used for 556 nm laser frequency stabilization, which is an alternative
means when applied to magneto-optical trapping of $^{171}$Yb.",1611.03249v3
2016-11-13,Nonlinear dynamics of a functionally graded piezoelectric micro-resonator in the vicinity of the primary resonance,"This research is on the nonlinear dynamics of a two-sided electrostatically
actuated capacitive micro-beam. The microresonator is composed of silicon and
PZT as a piezoelectric material. PZT is functionally distributed along the
height of the micro-beam according to the power law distribution. The
micro-resonator is simultaneously subjected to DC piezoelectric and two-sided
electrostatic actuations. The DC piezoelectric actuation leads to the
generation of an axial force along the length of the micro-beam and this is
used as a tuning tool to shift the primary resonance of the micro-resonator.
The governing equation of the motion is derived by the minimization of the
Hamiltonian and generalized to the viscously damped systems. The periodic
solutions in the vicinity of the primary resonance are detected by means of the
shooting method and their stability is investigated by determining the
so-called Floquet exponents of the perturbed motions. The basins of attraction
corresponding to three individual periodic orbits are determined. The results
depict that the higher the amplitude of the periodic orbit, the smaller is the
area of the attractor",1611.04105v1
2016-11-16,Superconducting Resonator-Rydberg Atom Hybrid in the Strong Coupling Regime,"We propose a promising hybrid quantum system, where a highly-excited atom
strongly interacts with a superconducting LC oscillator via the electric field
of capacitor. An external electrostatic field is applied to tune the energy
spectrum of atom. The atomic qubit is implemented by two eigenstates near an
avoided-level crossing in the DC Stark map of Rydberg atom. Varying the
electrostatic field brings the atomic-qubit transition on- or off-resonance to
the microwave resonator, leading to a strong atom-resonator coupling with an
extremely large cooperativity. Like the nonlinearity induced by Josephson
junctions in superconducting circuits, the large atom-resonator interface
disturbs the harmonic potential of resonator, resulting in an artificial
two-level particle. Different universal two-qubit logic gates can also be
performed on our hybrid system within the space where an atomic qubit couples
to a single photon with an interaction strength much larger than any relaxation
rates, opening the door to the cavity-mediated state transmission.",1611.05156v1
2016-11-16,Revising the $f_1(1420)$ resonance,"We have studied the production and decay of the $f_1(1285)$ into $\pi
a_0(980)$ and $K^* \bar K$ as a function of the mass of the resonance and find
a shoulder around 1400 MeV, tied to a triangle singularity, for the $\pi
a_0(980)$ mode, and a peak around 1420 MeV with about 60 MeV width for the $K^*
\bar K$ mode. Both these features agree with the experimental information on
which the $f_1(1420)$ resonance is based. In addition, we find that if the
$f_1(1420)$ is a genuine resonance, coupling mostly to $K^* \bar K$ as seen
experimentally, one finds unavoidably about a 20\% fraction for $\pi a_0(980)$
decay of this resonance, in drastic contradiction with all experiments.
Altogether, we conclude that the $f_1(1420)$ is not a genuine resonance, but
the manifestation of the $\pi a_0(980)$ and $K^* \bar K$ decay modes of the
$f_1(1285)$ at higher energies than the nominal one.",1611.05383v2
2017-01-09,Investigation of Feshbach Resonances in ultra-cold 40 K spin mixtures,"Magnetically-tunable Feshbach resonances are an indispensable tool for
experiments with atomic quantum gases. We report on twenty thus far unpublished
Feshbach resonances and twenty one further probable Feshbach resonances in spin
mixtures of ultracold fermionic 40 K with temperatures well below 100 nK. In
particular, we locate a broad resonance at B=389.6 G with a magnetic width of
26.4 G. Here 1 G=10^-4 T. Furthermore, by exciting low-energy spin waves, we
demonstrate a novel means to precisely determine the zero crossing of the
scattering length for this broad Feshbach resonance. Our findings allow for
further tunability in experiments with ultracold 40 K quantum gases.",1701.02085v1
2017-01-16,High-Q nested resonator in an actively stabilized optomechanical cavity,"Experiments involving micro- and nanomechanical resonators need to be
carefully designed to reduce mechanical environmental noise. A small scale
on-chip approach is to add an additional resonator to the system as a
mechanical low-pass filter. Unfortunately, the inherent low frequency of the
low-pass filter causes the system to be easily excited mechanically. Fixating
the additional resonator ensures that the resonator itself can not be excited
by the environment. This, however, negates the purpose of the low-pass filter.
We solve this apparent paradox by applying active feedback to the resonator,
thereby minimizing the motion with respect the front mirror of an
optomechanical cavity. Not only does this method actively stabilize the cavity
length, but it also retains the on-chip vibration isolation.",1701.04212v2
2017-03-31,"Numerical calculation of the decay widths, the decay constants, and the decay energy spectra of the resonances of the delta-shell potential","We express the resonant energies of the delta-shell potential in terms of the
Lambert $W$ function, and we calculate their decay widths and decay constants.
The ensuing numerical results strengthen the interpretation of such decay
widths and constants as a way to quantify the coupling between a resonance and
the continuum. We calculate explicitly the decay energy spectrum of the
resonances of the delta-shell potential, and we show numerically that the
lineshape of such spectrum is not the same as, and can be very different from,
the Breit-Wigner (Lorentzian) distribution. We argue that the standard Golden
Rule cannot describe the interference of two resonances, and we show how to
describe such interference by way of the decay energy spectrum of two resonant
states.",1704.00047v1
2017-04-07,Coherent Optomechanical State Transfer between Disparate Mechanical Resonators,"Hybrid quantum systems have been developed with various mechanical, optical
and microwave harmonic oscillators. The coupling produces a rich library of
interactions including two mode squeezing, swapping interactions, back-action
evasion and thermal control. In a multimode mechanical system, coupling
resonators of different scales (both in frequency and mass) leverages the
advantages of each resonance. For example: a high frequency, easily manipulated
resonator could be entangled with a low frequency massive object for tests of
gravitational decoherence. Here we demonstrate coherent optomechanical state
swapping between two spatially and frequency separated resonators with a mass
ratio of 4. We find that, by using two laser beams far detuned from an optical
cavity resonance, efficient state transfer is possible through a process very
similar to STIRAP (Stimulated Raman Adiabatic Passage) in atomic physics.
Although the demonstration is classical, the same technique can be used to
generate entanglement between oscillators in the quantum regime.",1704.02394v1
2017-04-11,Search for t t-bar resonances in highly boosted lepton+jets and fully hadronic final states in proton-proton collisions at sqrt(s) = 13 TeV,"A search for the production of heavy resonances decaying into top
quark-antiquark pairs is presented. The analysis is performed in the
lepton+jets and fully hadronic channels using data collected in proton-proton
collisions at sqrt(s) = 13 TeV using the CMS detector at the LHC, corresponding
to an integrated luminosity of 2.6 inverse femtobarns. The selection is
optimized for massive resonances, where the top quarks have large Lorentz
boosts. No evidence for resonant t t-bar production is found in the data, and
upper limits on the production cross section of heavy resonances are set. The
exclusion limits for resonances with masses above 2 TeV are significantly
improved compared to those of previous analyses at sqrt(s) = 8 TeV.",1704.03366v3
2017-04-19,Substrate Effect on Plasmonic Cube Dimers: Reversal of Optical Binding Force Induced by Strong Fano Resonance,"The behavior of Fano resonance and the reversal of near field optical binding
force of dimers over different substrates have not been studied so far. In this
work, we observe that if the closely located plasmonic cube homodimers over
glass or high permittivity dielectric substrate are illuminated with plane wave
polarized parallel to dimer axis, no reversal of optical binding force occurs.
But if we apply the same set-up over a plasmonic substrate, stable Fano
resonance occurs along with the reversal of near field binding force. It is
observed that during such Fano resonance stronger coupling occurs between the
dimers and plasmonic substrate along with the strong enhancement of the
substrate current. Such near field binding force reversals of plasmonic cube
dimers have been explained based on the observed unusual behavior of optical
Lorentz force during the induced stronger Fano resonance and the dipole-dipole
resonance. Although previously reported reversals of near field optical binding
forces were highly sensitive to particle size/shape (i.e. for heterodimers) and
inter-particle distance, our configuration provides much relaxation of those
parameters and hence should be verified experimentally with simpler
experimental set-ups.",1704.05633v1
2017-04-28,Two bosons in a narrowly resonant trap,"It is rare for an $S$-wave resonance to remain narrow while approaching
threshold as a result of the interaction parameters being fine tuned. Such an
interaction is, however, realized by pion-charmed baryon system $\pi \Sigma_c$,
which has a narrow resonance $\Lambda_c^+(2595)$ located a few MeVs above its
threshold. We study the consequence of narrowly resonant inter-species
interaction in a three-body system composed of two identical light bosons and
an extremely heavy particle. We concern ourselves in the present paper with
resonances of the three-body system, as opposed to bound states. The focus is
on the technical aspects of constructing the integral equation for three-body
amplitudes and of analytically continuing the integral equation to locate the
""trimer"" resonance pole in the unphysical sheet of the center-of-mass energy
plane.",1704.08935v1
2018-05-09,Interaction-induced photon blockade using an atomically thin mirror embedded in a microcavity,"Narrow dark resonances associated with electromagnetically induced
transparency play a key role in enhancing photon-photon interactions. The
schemes realized to date relied on the existence of long-lived atomic states
with strong van der Waals interactions. Here, we show that by placing an
atomically thin semiconductor with ultra-fast radiative decay rate inside a
\textcolor{black}{0D} cavity, it is possible to obtain narrow dark or bright
resonances in transmission whose width could be much smaller than that of the
cavity and bare exciton decay rates. While breaking of translational invariance
places a limit on the width of the dark resonance width, it is possible to
obtain a narrow bright resonance that is resilient against disorder by tuning
the cavity away from the excitonic transition. Resonant excitation of this
bright resonance yields strong photon antibunching even in the limit where the
interaction strength is arbitrarily smaller than the non-Markovian disorder
broadening and the radiative decay rate of the bare exciton. Our findings
suggest that atomically thin semiconductors could pave the way for realization
of strongly interacting photonic systems in the solid-state.",1805.03594v1
2018-05-09,Solvable cubic resonant systems,"Weakly nonlinear analysis of resonant PDEs in recent literature has generated
a number of resonant systems for slow evolution of the normal mode amplitudes
that possess remarkable properties. Despite being infinite-dimensional
Hamiltonian systems with cubic nonlinearities in the equations of motion, these
resonant systems admit special analytic solutions, which furthermore display
periodic perfect energy returns to the initial configurations. Here, we
construct a very large class of resonant systems that shares these properties
that have so far been seen in specific examples emerging from a few standard
equations of mathematical physics (the Gross-Pitaevskii equation, nonlinear
wave equations in Anti-de Sitter spacetime). Our analysis provides an
additional conserved quantity for all of these systems, which has been
previously known for the resonant system of the two-dimensional
Gross-Pitaevskii equation, but not for any other cases.",1805.03634v2
2018-04-24,Silicon photonic filters based on cascaded Sagnac loop resonators,"We demonstrate advanced integrated photonic filters in silicon-on-insulator
(SOI) nanowires implemented by cascaded Sagnac loop reflector (CSLR)
resonators. We investigate mode splitting in these standing-wave (SW)
resonators and demonstrate its use for engineering the spectral profile of
on-chip photonic filters. By changing the reflectivity of the Sagnac loop
reflectors (SLRs) and the phase shifts along the connecting waveguides, we
tailor mode splitting in the CSLR resonators to achieve a wide range of filter
shapes for diverse applications including enhanced light trapping, flat-top
filtering, Q factor enhancement, and signal reshaping. We present the
theoretical designs and compare the CSLR resonators with three, four, and eight
SLRs fabricated in SOI. We achieve versatile filter shapes in the measured
transmission spectra via diverse mode splitting that agree well with theory.
This work confirms the effectiveness of using CSLR resonators as integrated
multi-functional SW filters for flexible spectral engineering.",1805.05405v1
2018-05-21,Bulk and edge-state arcs in non-hermitian coupled-resonator arrays,"We describe the formation of bulk and edge arcs in the dispersion relation of
two-dimensional coupled-resonator arrays that are topologically trivial in the
hermitian limit. Each resonator provides two asymmetrically coupled internal
modes, as realized in noncircular open geometries, which enables the system to
exhibit non-hermitian physics. Neighboring resonators are coupled chirally to
induce non-hermitian symmetries. The bulk dispersion displays Fermi arcs
connecting spectral singularities known as exceptional points, and can be tuned
to display purely real and imaginary branches. At an interface between
resonators of different shape, one-dimensional edge states form that spectrally
align along complex arcs connecting different parts of the bulk bands. We also
describe conditions under which the edge-state arcs are free standing. These
features can be controlled via anisotropy in the resonator couplings.",1805.08161v1
2018-05-24,Measurement of nonlinear piezoelectric coefficients using a micromechanical resonator,"We describe and demonstrate a method by which the nonlinear piezoelectric
properties of a piezoelectric material may be measured by detecting the force
that it applies on a suspended micromechanical resonator at one of its
mechanical resonance frequencies. Resonators are used in countless
applications; this method could provide a means for better-characterizing
material behaviors within real MEMS devices. Further, special devices can be
designed to probe this nonlinear behavior at specific frequencies with enhanced
signal sizes. The resonators used for this experiment are actuated using a
1-$\mu$m-thick layer of aluminum nitride. When driven at large amplitudes, the
piezoelectric layer generates harmonics, which are measurable in the response
of the resonator. In this experiment, we measured the second-order
piezoelectric coefficient of aluminum nitride to be
$-(23.1\pm14.1)\times10^{-22}\ \mathrm{m/V^2}$.",1805.09696v1
2008-07-02,Feshbach resonances in ultracold 85Rb-87Rb and 6Li-87Rb mixtures,"We present an analysis of experimentally accessible magnetic Feshbach
resonances in ultra-cold hetero-nuclear 85Rb-87Rb and 6Li-87Rb mixtures. Using
recent experimental measurements of the triplet scattering lengths for 6Li-87Rb
and 7Li-87Rb mixtures and Feshbach resonances for one combination of atomic
states, we create model potential curves and fine tune them to reproduce the
measured resonances and to predict the location of several experimentally
relevant resonances in Li-Rb collisions. To model 85Rb-87Rb collisions, we use
accurate Rb_2 potentials obtained previously from the analysis of experiments
on 87Rb-87Rb collisions. We find resonances that occur at very low magnetic
fields, below 10 G, which may be useful for entanglement generation in optical
lattices or atom chip magnetic traps.",0807.0417v2
2008-07-29,Observation of a New Magnetic Response in 3-Dimensional Split Ring Resonators under Normal Incidence,"So far, research in the field of metamaterials has been carried out largely
with arrays of flat, 2-dimensional structures. Here, we report a newly
identified magnetic resonance in Split Cylinder Resonators (SCRs), a
3-dimensional version of the Split Ring Resonator (SRR), which were fabricated
with the Proton Beam Writing technique. Experimental and numerical results
indicate a hitherto unobserved 3-dimensional resonance mode under normal
incidence at about 26 THz, when the SCR depth is approximately half the free
space wavelength. This mode is characterized by strong currents along the
cylinder axis which are concentrated at the cylinder gaps. Due to their
orientation, these axial currents give rise to a magnetic response under normal
incidence, which is not possible in shallow SRRs. Our results reveal new
behavior in the SRR structure which arises from a change in its aspect ratio.
Such new resonances can have a significant influence on the quest for
practical, 3-dimensional metamaterials.",0807.4585v2
2008-07-29,Noise in an SSET-resonator driven by an external field,"We investigate the noise properties of a superconducting single electron
transistor (SSET) coupled to an harmonically driven resonator. Using a Langevin
equation approach, we calculate the frequency spectrum of the SSET charge and
calculate its effect on the resonator field. We find that the heights of the
peaks in the frequency spectra depend sensitively on the amplitude of the
resonator oscillation and hence suggest that the heights of these peaks could
act as a sensitive signal for detecting the small changes in the amplitude of
the drive. The previously known results for the effective amplitude-dependent
damping and temperature provided by the SSET for the case of a low frequency
resonator are generalized for all resonator frequencies.",0807.4612v1
2011-11-07,Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances,"We propose that macroscopic objects built from negative-permeability
metamaterials may experience resonantly enhanced magnetic force in
low-frequency magnetic fields. Resonant enhancement of the time-averaged force
originates from magnetostatic surface resonances (MSR) which are analogous to
the electrostatic resonances of negative-permittivity particles, well known as
surface plasmon resonances in optics. We generalize the classical problem of
MSR of a homogeneous object to include anisotropic metamaterials, and consider
the most extreme case of anisotropy where the permeability is negative in one
direction but positive in the others. It is shown that deeply subwavelength
objects made of such indefinite (hyperbolic) media exhibit a pronounced
magnetic dipole resonance that couples strongly to uniform or weakly
inhomogeneous magnetic field and provides strong enhancement of the magnetic
force, enabling applications such as enhanced magnetic levitation.",1111.1695v2
2011-11-28,"Bayesian inference of the resonance content of p(gamma,K^+)Lambda","A Bayesian analysis of the world's p(gamma,K^+)Lambda data is presented. From
the proposed selection of 11 resonances, we find that the following nucleon
resonances have the highest probability of contributing to the reaction:
S11(1535), S11(1650), F15(1680), P13(1720), D13(1900), P13(1900), P11(1900),
and F15(2000). We adopt a Regge-plus-resonance framework featuring consistent
couplings for nucleon resonances up to spin J=5/2. We evaluate all possible
combinations of 11 candidate resonances. The best model is selected from the
2048 model variants by calculating the Bayesian evidence values against the
world's p(gamma,K^+)Lambda data.",1111.6511v2
2011-11-29,A Search for ttbar Resonances in the Dilepton Channel in 1.04 fb^-1 of pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment,"A search for a high mass ttbar resonance in pp collisions at sqrt(s) = 7 TeV
at the LHC is presented. We search for such a resonance using the final state
where the $W$ bosons from the top quark decay into either an electron or a muon
(dilepton final state). The data were recorded by the ATLAS experiment during
2011 and correspond to a total integrated luminosity of L = 1.04 fb^-1. No
statistically significant excess above the Standard Model expectation is
observed. Upper limits at the 95% Confidence Level (C.L.) are set on the cross
section times branching ratio of the resonance decaying to ttbar pairs as a
function of the resonance mass. A lower mass limit of 0.84 TeV is set for the
case of a Kaluza-Klein gluon resonance in the Randall-Sundrum Model.",1111.6933v1
2011-12-30,Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons,"Resonance diffraction in the periodic array of graphene micro-ribbons is
theoretically studied following a recent experiment [L. Ju et al, Nature
Nanotech. 6, 630 (2011)]. Systematic studies over a wide range of parameters
are presented. It is shown that a much richer resonant picture would be
observable for higher relaxation times of charge carriers: more resonances
appear and transmission can be totally suppressed. The comparison with the
absorption cross-section of a single ribbon shows that the resonant features of
the periodic array are associated with leaky plasmonic modes. The
longest-wavelength resonance provides the highest visibility of the
transmission dip and has the strongest spectral shift and broadening with
respect to the single-ribbon resonance, due to collective effects.",1201.0191v1
2012-01-10,Nonequilibrium Damping of Collective Motion of Homogeneous Cold Fermi Condensates with Feshbach Resonances,"Collisionless damping of a condensate of cold Fermi atoms, whose scattering
is controlled by a Feshbach resonance, is explored throughout the BCS and BEC
regimes when small perturbations on its phase and amplitude modes are turned on
to drive the system slightly out of equilibrium. Using a one-loop effective
action, we first recreate the known result that for a broad resonance the
amplitude of the condensate decays as $t^{-1/2}$ at late times in the BCS
regime whereas it decays as $t^{-3/2}$ in the BEC regime. We then examine the
case of an idealized narrow resonance, and find that this collective mode
decays as $t^{-3/2}$ throughout both the BCS and BEC regimes. Although this
seems to contradict earlier results that damping is identical for both broad
and narrow resonances, the breakdown of the narrow resonance limit restores
this universal behaviour. More measureably, the phase perturbation may give a
shift on the saturated value to which the collective amplitude mode decays,
which vanishes only in the deep BCS regime when the phase and amplitude modes
are decoupled.",1201.2019v1
2012-01-16,Planar Superconducting Resonators with Internal Quality Factors above One Million,"We describe the fabrication and measurement of microwave coplanar waveguide
resonators with internal quality factors above 10 million at high microwave
powers and over 1 million at low powers, with the best low power results
approaching 2 million, corresponding to ~1 photon in the resonator. These
quality factors are achieved by controllably producing very smooth and clean
interfaces between the resonators' aluminum metallization and the underlying
single crystal sapphire substrate. Additionally, we describe a method for
analyzing the resonator microwave response, with which we can directly
determine the internal quality factor and frequency of a resonator embedded in
an imperfect measurement circuit.",1201.3384v1
2012-01-30,Highly resolved measurements of Stark-tuned Förster resonances between Rydberg atoms,"We report on experiments exploring Stark-tuned F\""orster resonances between
Rydberg atoms with unprecedented resolution in the F\""orster defect. The
individual resonances are expected to exhibit different angular dependencies,
opening the possibility to tune not only the interaction strength but also the
angular dependence of the pair state potentials by an external electric field.
We achieve a high resolution by optical Ramsey interferometry for Rydberg atoms
combined with electric field pulses. The resonances are detected by a loss of
visibility in the Ramsey fringes due to resonances in the interaction. We
present measurements of the density dependence as well as of the coherence time
at and close to F\""orster resonances.",1201.6210v1
2012-01-31,Parametric amplification and self-oscillation in a nanotube mechanical resonator,"A hallmark of mechanical resonators made from a single nanotube is that the
resonance frequency can be widely tuned. Here, we take advantage of this
property to realize parametric amplification and self-oscillation. The gain of
the parametric amplification can be as high as 18.2 dB and tends to saturate at
high parametric pumping due to nonlinear damping. These measurements allow us
to determine the coefficient of the linear damping force. The corresponding
damping rate is lower than the one obtained from the lineshape of the resonance
(without pumping), supporting the recently reported scenario that describes
damping in nanotube resonators by a nonlinear force. The possibility to combine
nanotube resonant mechanics and parametric amplification holds promise for
future ultra-low force sensing experiments.",1201.6557v1
2012-04-09,Frequency and phase noise of ultra-high Q silicon nitride nanomechanical resonators,"We describe the measurement and modeling of amplitude noise and phase noise
in ultra-high Q nanomechanical resonators made from stoichiometric silicon
nitride. With quality factors exceeding 2 million, the resonators' noise
performance is studied with high precision. We find that the amplitude noise
can be well described by the thermomechanical model, however, the resonators
exhibit sizable extra phase noise due to their intrinsic frequency
fluctuations. We develop a method to extract the resonator frequency
fluctuation of a driven resonator and obtain a noise spectrum with dependence,
which could be attributed to defect motion with broadly distributed relaxation
times.",1204.1942v1
2012-04-16,Nonlinear Induction Detection of Electron Spin Resonance,"We present a new approach to the induction detection of electron spin
resonance (ESR) signals exploiting the nonlinear properties of a
superconducting resonator. Our experiments employ a yttrium barium copper oxide
(YBCO) superconducting stripline microwave (MW) resonator integrated with a
microbridge. A strong nonlinear response of the resonator is thermally
activated in the microbridge when exceeding a threshold in the injected MW
power. The responsivity factor characterizing the ESR-induced change in the
system's output signal is about 100 times larger when operating the resonator
near the instability threshold, compared to the value obtained in the linear
regime of operation. Preliminary experimental results, together with a
theoretical model of this phenomenon are presented. Under appropriate
conditions nonlinear induction detection of ESR can potentially improve upon
the current capabilities of conventional linear induction detection ESR.",1204.3588v2
2012-04-20,Radiative and non-radiative effects of a substrate on localized plasmon resonance of particles,"Experiments have shown strong effects of some substrates on the localized
plasmons of metallic nano particles but they are inconclusive on the affecting
parameters. Here we have used Discrete Dipole Approximation in conjunction with
Sommerfeld integral relations to explain the effect of the substrates as a
function of the parameters of incident radiation. The radiative coupling can
both quench and enhance the resonance and its dependence on the angle and
polarization of incident radiation with respect to the surface is shown.
Non-radiative interaction with the substrate enhances the plasmon resonance of
the particles and can shift the resonances from their free-space energies
significantly. The non-radiative interaction of the substrate is sensitive to
the shape of particles and polarization of incident radiation with respect to
substrate. Our results show that plasmon resonances in coupled and single
particles can be significantly altered from their free-space resonances and are
quenched or enhanced by the choice of substrate and polarization of incident
radiation.",1204.4556v1
2013-09-18,Cooling of a Nanomechanical Resonator in the Presence of a Single Diatomic Molecule,"We propose a theoretical scheme for coupling a nanomechanical resonator to a
single diatomic molecule via microwave cavity mode of a driven LC resonator. We
describe the diatomic molecule by a Morse potential and find the corresponding
equations of motion of the hybrid system by using Fokker-Planck formalism.
Analytical expressions for the effective frequency and the effective damping of
the nanomechanical resonator are obtained. We analyze the ground state cooling
of the nanomechanical resonator in presence of the diatomic molecule. The
results confirm that presence of the molecule improves the cooling process of
the mechanical resonator. Finally, the effect of molecule's parameters on the
cooling mechanism is studied.",1309.4804v3
2013-09-20,Implementation of a Quantum Metamaterial,"Manipulating the propagation of electromagnetic waves through sub-wavelength
sized artificial structures is the core function of metamaterials. Resonant
structures, such as split ring resonators, play the role of artificial ""atoms""
and shape the magnetic response. Superconducting metamaterials moved into the
spotlight for their very low ohmic losses and the possibility to tune their
resonance frequency by exploiting the Josephson inductance. Moreover, the
nonlinear nature of the Josephson inductance enables the fabrication of truly
artificial atoms. Arrays of such superconducting quantum two-level systems
(qubits) can be used for the implementation of a quantum metamaterial. Here, we
perform an experiment in which 20 superconducting flux qubits are embedded into
a single microwave resonator. The phase of the signal transmitted through the
resonator reveals the collective resonant coupling of up to 8 qubits. Quantum
circuits of many artificial atoms based on this proof-of-principle experiment
offer a wide range of prospects, from detecting single microwave photons to
phase switching, quantum birefringence and superradiant phase transitions.",1309.5268v1
2013-09-24,Double Fano resonances in a composite metamaterial possessing tripod plasmonic resonances,"By embedding four-rod resonators inside double-split ring resonators
superlattice, a planar composite metamaterial possessing tripod plasmonic
resonances is fabricated. Double Fano resonances are observed where a common
subradiant driven oscillator is coupled with two superradiant oscillators. As a
classical analogue of four-level tripod atomic system, the transmission
spectrum of the composite metamaterial exhibits a double Fano-based coherent
effect. Transfer of absorbed power between two superradiant oscillators is
controlled by manipulating two coupling strengths conjugated through the
polarization angle of a normally incident electromagnetic wave.",1309.6219v2
2013-09-25,The vector resonance triplet with the direct coupling to the third quark generation,"The effective Lagrangian with scalar and vector resonances that might result
from new strong physics beyond the SM is formulated and studied. In particular,
the scalar resonance representing the recently discovered 125-GeV boson is
complemented with the SU(2)_{L+R} triplet of hypothetical vector resonances.
Motivated by experimental and theoretical considerations, the vector resonance
is allowed to couple directly to the third quark generation only. The coupling
is chiral-dependent and the interaction of the right top quark can differ from
that of the right bottom quark. To estimate the applicability range of the
effective Lagrangian the unitarity of the gauge boson scattering amplitudes is
analyzed. The experimental fits and limits on the free parameters of the vector
resonance triplet are investigated.",1309.6597v1
2013-09-25,Silicon-based Infrared Metamaterials with Ultra-Sharp Fano Resonances,"Metamaterials and meta-surfaces represent a remarkably versatile platform for
light manipulation, biological and chemical sensing, nonlinear optics, and even
spaser lasing. Many of these applications rely on the resonant nature of
metamaterials, which is the basis for extreme spectrally selective
concentration of optical energy in the near field. The simplicity of free-space
light coupling into sharply-resonant meta-surfaces with high resonance quality
factors Q>>1 is a significant practical advantage over the extremely
angle-sensitive diffractive structures or inherently inhomogeneous high-Q
photonic structures such as toroid or photonic crystal microcavities. Such
spectral selectivity is presently impossible for the overwhelming majority of
metamaterials that are made of metals and suffer from high plasmonic losses.
Here, we propose and demonstrate Fano-resonant all-semiconductor optical
meta-surfaces supporting optical resonances with quality factors Q>100 that are
almost an order of magnitude sharper than those supported by their plasmonic
counterparts. These silicon-based structures are shown to be planar chiral,
opening exciting possibilities for efficient ultra-thin circular polarizers and
narrow-band thermal emitters of circularly polarized radiation.",1309.6616v1
2013-09-27,Split-ball resonator,"We introduce a new concept of split-ball resonator and demonstrate a strong
magnetic dipole response for both gold and silver spherical plasmonic
nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole
resonance throughout the visible spectral range is demonstrated by changing the
depth and width of the nanoscale cut. We realize this novel concept
experimentally by employing the laser-induced transfer method to produce
near-perfect spheres and helium ion beam milling to make cuts with the
nanometer resolution. Due to high quality of the spherical particle shape
governed by strong surface tension forces during the laser transfer process and
clean, straight side walls of the cut made by helium ion milling, the magnetic
resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles.
Structuring arbitrary features on the surface of nanoscale spherical resonators
provides new ways for engineering hybrid resonant modes and ultra-high
near-field enhancement.",1309.7106v2
2014-05-07,Optical Feshbach resonances through a molecular dark state: Efficient manipulation of $p$-wave resonances in fermionic $^{171}$Yb atoms,"In a recent experiment by Yamazaki {\it et al.} [Phys.Rev. A {\bf 87} 010704
(R) (2013) ], $p$-wave optical Feshbach resonance in fermionic $^{171}$Yb atoms
using purely long-range molecular excited states has been demonstrated. We
theoretically show that, if two purely long range excited states of $^{171}$Yb
are coupled to the ground-state continuum of scattering states with two lasers,
then it is possible to significantly suppress photoassociative atom loss by a
dark resonance in the excited states. We present a general theoretical
framework for creating a dark state in electronically excited molecular
potential for the purpose of increasing the efficiency of an optical Feshbach
resonance. This can be accomplished by properly adjusting the relative
intensity, phase, polarizations and frequency detunings of two lasers. We
present selective numerical results on atom loss spectra, $p$-wave elastic and
inelastic scattering cross sections of $^{171}$Yb atoms to illustrate the
effects of the molecular dark state on optical Feshbach resonance.",1405.1674v2
2014-05-08,PT-symmetric microring lasers: Self-adapting broadband mode-selective resonators,"We demonstrate experimentally that stable single longitudinal mode operation
can be readily achieved in PT-symmetric arrangements of coupled microring
resonators. Whereas any active resonator is in principle capable of displaying
single-wavelength operation, selective breaking of PT-symmetry can be utilized
to systematically enhance the maximum achievable gain of this mode, even if a
large number of competing longitudinal or transverse resonator modes fall
within the amplification bandwidth of the inhomogeneously broadened active
medium. This concept is robust with respect to fabrication tolerances, and its
mode selectivity is established without the need for additional components or
specifically designed filters. Our results may pave the way for a new
generation of versatile cavities lasing at a desired longitudinal resonance.
Along these lines, traditionally highly multi-moded microring resonator
configurations can be fashioned to suppress all but one longitudinal mode.",1405.2103v1
2014-05-23,Radiative Emission Enhancement Using Nano-antennas Made of Hyperbolic Metamaterial Resonators,"A hyperbolic metamaterial (HM) resonator is analyzed as a nano-antenna for
enhancing the radiative emission of quantum emitters in its vicinity. It has
been shown that the spontaneous emission rate by an emitter near a hyperbolic
metamaterial substrate is enhanced dramatically due to very large density of
states. However, enhanced coupling to the free-space, which is central to
applications such as solid-state lighting, has not been investigated
significantly. Here, we numerically demonstrate approximately 100 times
enhancement of the free-space radiative emission at 660 nm wavelength by
utilizing a cylindrical HM resonator with a radius of 54 nm and a height of 80
nm on top of an opaque silver-cladded substrate. We also show how the
free-space radiation enhancement factor depends on the dipole orientation and
the location of the emitter near the subwavelength resonator. Furthermore, we
calculate that an array of HM resonators with subwavelength spacings can
maintain most of the enhancement effect of a single resonator.",1405.6165v2
2014-06-10,Heavy Z': resonant versus non-resonant searches,"Collider searches for new vector-like particles such as Z' have mostly been
pursued by looking for a peak in the invariant mass spectrum of the decay
products. However off-shell Z' exchange may leave an imprint on other kinematic
distributions, leading thus to non-resonant searches. The aim of this paper is
to assess, in the context of the LHC, the interplay between resonant
(s-channel) and non-resonant (t-channel) searches for a generic leptophobic Z'
model. We show in particular that while non-resonant searches are less
sensitive to small couplings, they tend to be more adapted at high masses and
large couplings. We discuss our findings both at the level of the current
limits and the expectations at higher luminosities.",1406.2547v1
2015-12-15,Rays of light from the LHC,"We consider models for the di-photon resonance observed at ATLAS (with 3.6
fb^{-1}) and CMS (with 2.6 fb^{-1}). We find there is no conflict between the
signal reported at 13 TeV, and the constraints from both experiments at 8 TeV
with 20.3 fb^{-1}. We make a simple argument for why adding only one new
resonance to the standard model (SM) is not sufficient to explain the
observation. We explore four viable options: (i): resonance production and
decay through loops of messenger fermions or scalars; (ii): a resonant
messenger which decays to the di-photon resonance + X; (iii): an edge
configuration where A -> B gamma -> C gamma gamma, and (iv): Hidden Valley-like
models where the resonance decays to a pair of very light (sub-GeV) states,
each of which in turn decays to a pair of collimated photons that cannot be
distinguished from a single photon. Since in each case multiple new states have
been introduced, a wealth of signatures is expected to ensue at Run-2 of LHC.",1512.04928v2
2016-05-01,750 GeV diphoton resonance and electric dipole moments,"We examine the implication of the recently observed 750 GeV diphoton excess
for the electric dipole moments of the neutron and electron. If the excess is
due to a spin zero resonance which couples to photons and gluons through the
loops of massive vector-like fermions, the resulting neutron electric dipole
moment can be comparable to the present experimental bound if the CP-violating
angle {\alpha} in the underlying new physics is of O(10^{-1}). An electron EDM
comparable to the present bound can be achieved through a mixing between the
750 GeV resonance and the Standard Model Higgs boson, if the mixing angle
itself for an approximately pseudoscalar resonance, or the mixing angle times
the CP-violating angle {\alpha} for an approximately scalar resonance, is of
O(10^{-3}). For the case that the 750 GeV resonance corresponds to a composite
pseudo-Nambu-Goldstone boson formed by a QCD-like hypercolor dynamics confining
at \Lambda_HC, the resulting neutron EDM can be estimated with \alpha ~ (750
GeV / \Lambda_HC)^2\theta_HC, where \theta_HC is the hypercolor vacuum angle.",1605.00206v1
2016-05-06,Optimized Coplanar Waveguide Resonators for a Superconductor-Atom Interface,"We describe the design and characterization of superconducting coplanar
waveguide cavities tailored to facilitate strong coupling between
superconducting quantum circuits and single trapped Rydberg atoms. For initial
superconductor-atom experiments at 4.2 K, we show that resonator quality
factors above $10^4$ can be readily achieved. Furthermore, we demonstrate that
the incorporation of thick-film copper electrodes at a voltage antinode of the
resonator provides a route to enhance the zero-point electric fields of the
resonator in a trapping region that is 40 $\mu$m above the chip surface,
thereby minimizing chip heating from scattered trap light. The combination of
high resonator quality factor and strong electric dipole coupling between the
resonator and the atom should make it possible to achieve the strong coupling
limit of cavity quantum electrodynamics with this system.",1605.01996v3
2016-05-11,Lattice Induced Transparency in Metasurfaces,"Lattice modes are intrinsic to the periodic structures and their occurrence
can be easily tuned and controlled by changing the lattice constant of the
structural array. Previous studies have revealed excitation of sharp absorption
resonances due to lattice mode coupling with the plasmonic resonances. Here, we
report the first experimental observation of a lattice induced transparency
(LIT) by coupling the first order lattice mode (FOLM) to the structural
resonance of a metamaterial resonator at terahertz frequencies. The observed
sharp transparency is a result of the destructive interference between the
bright mode and the FOLM mediated dark mode. As the FOLM is swept across the
metamaterial resonance, the transparency band undergoes large change in its
bandwidth and resonance position. Besides controlling the transparency
behaviour, LIT also shows a huge enhancement in the Q-factor and record high
group delay of 28 ps, which could be pivotal in ultrasensitive sensing and slow
light device applications.",1605.03277v1
2016-08-02,"Tilted resonators in a triangular elastic lattice: chirality, Bloch waves and negative refraction","We consider a vibrating triangular mass-truss lattice whose unit cell
contains a resonator of a triangular shape. The resonators are connected to the
triangular lattice by trusses. Each resonator is tilted, i.e. it is rotated
with respect to the triangular lattice's unit cell through an angle
$\vartheta_0$. This geometrical parameter is responsible for the emergence of a
resonant mode in the Bloch spectrum for elastic waves and strongly affects the
dispersive properties of the lattice. Additionally, the tilting angle
$\vartheta_0$ triggers the opening of a band gap at a Dirac-like point. We
provide a physical interpretation of these phenomena and discuss the dynamical
implications on elastic Bloch waves. The dispersion properties are used to
design a structured interface containing tilted resonators which exhibit
negative refraction and focussing, as in a ""flat elastic lens"".",1608.00968v1
2016-08-05,Seismic metasurfaces: Sub-wavelength resonators and Rayleigh wave interaction,"We consider the canonical problem of an array of rods, which act as
resonators, placed on an elastic substrate; the substrate being either a thin
elastic plate or an elastic half-space. In both cases the flexural plate, or
Rayleigh surface, waves in the substrate interact with the resonators to create
interesting effects such as effective band-gaps for surface waves or filters
that transform surface waves into bulk waves; these effects have parallels in
the field of optics where such sub-wavelength resonators create metamaterials,
and metasurfaces, in the bulk and at the surface respectively.
  Here we carefully analyse this canonical problem by extracting the dispersion
relations analytically thereby examining the influence of both the flexural and
compressional resonances on the propagating wave. For an array of resonators
atop an elastic half-space we augment the analysis with numerical simulations.
Amongst other effects, we demonstrate the striking effect of a dispersion curve
that transitions from Rayleigh wave-like to shear wave-like behaviour and the
resultant change in displacement from surface to bulk waves.",1608.01792v1
2016-08-04,Wireless transfer of power by a 35-GHz metamaterial split-ring resonator rectenna,"Wireless transfer of power via high frequency microwave radiation using a
miniature split ring resonator rectenna is reported. RF power is converted into
DC power by integrating a rectification circuit with the split ring resonator.
The near-field behavior of the rectenna is investigated with microwave
radiation in the frequency range between 20-40 GHz with a maximum power level
of 17 dBm. The observed resonance peaks match those predicted by simulation.
Polarization studies show the expected maximum in signal when the electric
field is polarized along the edge of the split ring resonator with the gap and
minimum for perpendicular orientation. The efficiency of the rectenna is on the
order of 1% for a frequency of 37.2 GHz. By using a cascading array of 9 split
ring resonators the output power was increased by a factor of 20.",1608.02490v1
2016-08-10,Resonant driving of a single photon emitter embedded in a mechanical oscillator,"Coupling a microscopic mechanical resonator to a nano-scale quantum system
enables control of the mechanical resonator via the quantum system, and vice
versa. The coupling is usually achieved through functionalization of the
mechanical resonator but this results in additional mass and dissipation
channels. An alternative is an intrinsic coupling based on strain. We employ
here a monolithic semiconductor system. The nano-scale quantum system is a
quantum dot; the mechanical resonator a microscopic trumpet which
simultaneously optimizes the mechanical and photonic properties. The quantum
dot transition is driven resonantly. Via the resonance fluorescence, we observe
mechanical Brownian motion even at 4K, and demonstrate a coupling to mechanical
modes of different types. We identify a mechanical mode with a cooperativity
larger than one. We show analytically that the Heisenberg limit on displacement
measurement can be reached with an embedded two-level system in the case of a
transform-limited optical emitter with perfect photon detection. We argue that
operation close to the Heisenberg limit is achievable with state-of-the-art
quantum dot devices.",1608.03082v1
2016-08-15,Heralded quantum controlled phase gates with dissipative dynamics in macroscopically-distant resonators,"Heralded near-deterministic multi-qubit controlled phase gates with
integrated error detection have recently been proposed by Borregaard et al.
[Phys. Rev. Lett. 114, 110502 (2015)]. This protocol is based on a single
four-level atom (a heralding quartit) and $N$ three-level atoms (operational
qutrits) coupled to a single-resonator mode acting as a cavity bus. Here we
generalize this method for two distant resonators without the cavity bus
between the heralding and operational atoms. Specifically, we analyze the
two-qubit controlled-Z gate and its multi-qubit-controlled generalization
(i.e., a Toffoli-like gate) acting on the two-lowest levels of $N$ qutrits
inside one resonator, with their successful actions being heralded by an
auxiliary microwave-driven quartit inside the other resonator. Moreover, we
propose a circuit-quantum-electrodynamics realization of the protocol with flux
and phase qudits in linearly-coupled transmission-line resonators with
dissipation. These methods offer a quadratic fidelity improvement compared to
cavity-assisted deterministic gates.",1608.04195v3
2016-08-23,Resonant Response in Mechanically Tunable Metasurface based on Crossed Metallic Gratings with Controllable Crossing Angle,"We report on a new class of mechanically tunable planar metamaterials
comprising resonating units formed by crossed metallic strip gratings. We
observe a resonant response in transmission spectra of a linearly polarized
wave passing through the system of crossed gratings. Each grating consists of
an array of parallel metallic strips located on the top of a dielectric
substrate. It is revealed that the resonant position appears to be dependent on
the angle of gratings crossing. It is found out both theoretically and
experimentally that the resonant shift on the frequency scale appears as a
result of increasing in the length of the resonating portion of the
parallelogram periodic cell formed by the crossed metallic strips with
decreasing crossing angle and the proposed design can be used in new types of
planar metamaterials and filters.",1608.06629v2
2016-12-13,SU-8 clamped CVD graphene drum resonators,"Graphene mechanical resonators are the ultimate two-dimensional
nanoelectromechanical systems (NEMS) with applications in sensing and signal
processing. While initial devices have shown promising results, an ideal
graphene NEMS resonator should be strain engineered, clamped at the edge
without trapping gas underneath, and electrically integratable. In this letter,
we demonstrate fabrication and direct electrical measurement of circular SU-8
polymer-clamped chemical vapor deposition (CVD) graphene drum resonators. The
clamping increases device yield and responsivity, while providing a cleaner
resonance spectrum from eliminated edge modes. Furthermore, this resonator is
highly strained, indicating its potential in strain engineering for performance
enhancement.",1612.04279v1
2016-12-21,Superconducting grid-bus surface code architecture for hole-spin qubits,"We present a scalable hybrid architecture for the 2D surface code combining
superconducting resonators and hole-spin qubits in nanowires with tunable
direct Rashba spin-orbit coupling. The back-bone of this architecture is a
square lattice of capacitively coupled coplanar waveguide resonators each of
which hosts a nanowire hole-spin qubit. Both the frequency of the qubits and
their coupling to the microwave field are tunable by a static electric field
applied via the resonator center pin. In the dispersive regime, an entangling
two-qubit gate can be realized via a third order process, whereby a virtual
photon in one resonator is created by a first qubit, coherently transferred to
a neighboring resonator, and absorbed by a second qubit in that resonator.
Numerical simulations with state-of-the-art coherence times yield gate
fidelities approaching the $99\%$ fault tolerance threshold.",1612.07292v1
2016-12-23,"Parametric oscillation, frequency mixing and injection locking of strongly coupled nanomechanical resonator modes","We study locking phenomena of two strongly coupled, high-quality factor
nanomechanical resonator modes subject to a common parametric drive at a single
drive frequency. By controlled dielectric gradient forces we tune the resonance
frequencies of the flexural in-plane and out-of-plane oscillation of the high
stress silicon nitride string through their mutual avoided crossing. For the
case of the strong common parametric drive signal-idler generation via
parametric oscillation is observed, analogously to the framework of nonlinear
optical effects in an optical parametric oscillator. Frequency tuning of the
signal and idler resonances is demonstrated. When the resonance frequencies of
signal and idler get closer to each other, partial injection locking, injection
pulling and complete injection locking to half of the drive frequency occurs
depending on the pump strength. Furthermore, satellite resonances,
symmetrically off-set from signal and idler by their beat-note, are observed
which can be attributed to degenerate four-wave-mixing in the highly nonlinear
mechanical oscillations.",1612.07955v1
2017-07-04,Tuning of bound states in the continuum by waveguide rotation,"We consider acoustic wave transmission in non axisymmetric waveguide which
consists of cylindrical resonator and two semi-infinite cylindrical waveguides
whose axes are shifted relative to the resonator axis and each other by
azimuthal angle $\Delta\phi$. We show that for rotation of one of attached
waveguides the coupling matrix elements of the eigenmodes of resonator
classified by the integer $m$ and propagating mode of the waveguide acquire
phase factor $e^{im\Delta\phi}$. That crucially effect Fano resonances and
creates an analog of faucet opening and closing wave flux under rotation of the
waveguide. We show that under the rotation of the waveguide and variation of
the length of resonator numerous bound states in the continuum occur
complimenting by the Fano resonance collapse.",1707.00864v1
2017-07-10,Coupling ultracold atoms to a superconducting coplanar waveguide resonator,"We demonstrate coupling of magnetically trapped ultracold $^87$Rb ground
state atoms to a coherently driven superconducting coplanar resonator on an
integrated atom chip. We measure the microwave field strength in the cavity
through observation of the AC shift of the hyperfine transition frequency when
the cavity is driven off-resonance from the atomic transition. The measured
shifts are used to reconstruct the field in the resonator, in close agreement
with transmission measurements of the cavity, giving proof of the coupling
between atoms and resonator. When driving the cavity in resonance with the
atoms, we observe Rabi oscillations between atomic hyperfine states,
demonstrating coherent control of the atomic states through the cavity field.
The observation of two-photon Rabi oscillations using an additional external
radio frequency enables the preparation of magnetically trapped coherent
superposition states near the superconducting cavity, which are required for
the implementation of an atomic quantum memory.",1707.02730v1
2017-07-13,Period-tripling subharmonic oscillations in a driven superconducting resonator,"We have observed period-tripling subharmonic oscillations, in a
superconducting coplanar waveguide resonator operated in the quantum regime,
$k_B T \ll \hbar\omega$. The resonator is terminated by a tunable inductance
that provides a Kerr-type nonlinearity. We detected the output field
quadratures at frequencies near the fundamental mode, $\omega/2\pi \sim
5\,$GHz, when the resonator was driven by a current at $3\omega$ with an
amplitude exceeding an instability threshold. The output radiation was
red-detuned from the fundamental mode. We observed three stable radiative
states with equal amplitudes and phase-shifted by $120^\circ$. The
downconversion from $3\omega$ to $\omega$ is strongly enhanced by resonant
excitation of the second mode of the resonator, and the cross-Kerr effect. Our
experimental results are in quantitative agreement with a model for the driven
dynamics of two coupled modes.",1707.04093v3
2017-07-18,Suppression of electron scattering resonances in graphene by quantum dots,"Transmission of low-energetic electrons through two-dimensional materials
leads to unique scattering resonances. These resonances contribute to
photoemission from occupied bands where they appear as strongly dispersive
features of suppressed photoelectron intensity. Using angle-resolved
photoemission we have systematically studied scattering resonances in epitaxial
graphene grown on the chemically differing substrates Ir(111), Bi/Ir, Ni(111)
as well as in graphene/Ir(111) nanopatterned with a superlattice of uniform Ir
quantum dots. While the strength of the chemical interaction with the substrate
has almost no effect on the dispersion of the scattering resonances, their
energy can be controlled by the magnitude of charge transfer from/to graphene.
At the same time, a superlattice of small quantum dots deposited on graphene
eliminates the resonances completely. We ascribe this effect to a
nanodot-induced buckling of graphene and its local rehybridization from
sp$^{2}$ to sp$^{3}$ towards a three-dimensional structure. Our results suggest
nanopatterning as a prospective tool for tuning optoelectronic properties of
two-dimensional materials with graphene-like structure.",1707.05577v1
2017-07-31,Giant resonance and anomalous quality factor scaling in coupled resonator optical waveguides at the degenerate band edge,"We propose a novel scheme for enhancing the quality factor of coupled
resonators optical waveguides (CROWs) when operating near a degenerate band
edge (DBE). A DBE is a four-mode exceptional point of degeneracy (EPD)
occurring when four Bloch eigenmodes coalesce providing a resonance condition
with a giant enhancement in fields. We report an unprecedented scaling law of
quality factor of CROWs when operating at the DBE, even in the presence of
losses and structural perturbations. Remarkably, the Q factor of the proposed
CROW can be engineered to exceed that of a single ring resonator having a
diameter equal to the CROW length, hence having an overall strong area
reduction. The findings reported in this letter are critical for enhancing
fields amplitudes to giant levels and the Q factor of ring resonators and are
very beneficial for various applications including four wave mixing, Q
switching, lasers, and highly sensitive sensors.",1707.09737v1
2017-10-14,Repulsive polarons in alkaline-earth(-like) atoms across an orbital Feshbach resonance,"We characterize properties of the so-called repulsive polaron across the
recently discovered orbital Feshbach resonance in alkaline-earth(-like) atoms.
Being a metastable quasiparticle excitation at the positive energy, the
repulsive polaron is induced by the interaction between an impurity atom and a
Fermi sea. By analyzing in detail the energy, the polaron residue, the
effective mass, and the decay rate of the repulsive polaron, we reveal
interesting features that are intimately related to the two-channel nature of
the orbital Feshbach resonance. In particular, we find that the life time of
the repulsive polaron is non-monotonic in the Zeeman-field detuning bewteen the
two channels, and has a maximum on the BEC-side of the resonance. Further, by
considering the stability of a mixture of the impurity and the majority atoms
against phase separation, we show that the itin- erant ferromagnetism may exist
near the orbital Feshbach resonance at appropriate densities. Our results can
be readily probed experimentally, and have interesting implications for the
observation of itinerant ferromagnetism near an orbital Feshbach resonance.",1710.05166v1
2017-10-25,Line-driven ablation of circumstellar discs: II. Analyzing the role of multiple resonances,"We extend our previous study of radiative ablation of circumstellar disks by
line-scattering of the star's radiation, accounting now for the effect of
multiple line resonances off the stellar limb. For an analytic,
three-dimensional model of the velocity structure of an equatorial Keplerian
disk bounded at higher latitudes by a radially accelerating stellar wind
outflow, we use root-finding methods to identify multiple resonances from a
near-disk circumstellar location along starward rays both on and off the
stellar core. Compared to our previous study that accounted only for the effect
of on-core resonances in reducing the radiative driving through the scattering
of radiation away from a near-disk circumstellar location, including off-limb
resonances leads to additional radiative driving from scattering toward this
location. Instead of the up-to-50% reduction in line-acceleration previously
inferred from multiple resonance effects, we now find a more modest 15-20% net
reduction.",1710.09312v2
2017-12-12,Topological interface modes in local resonant acoustic systems,"Topological phononic crystals (PCs) are periodic artificial structures which
can support nontrivial acoustic topological bands, and their topological
properties are linked to the existence of topological edge modes. Most previous
studies focused on the topological edge modes in Bragg gaps which are induced
by lattice scatterings. While local resonant gaps would be of great use in
subwavelength control of acoustic waves, whether it is possible to achieve
topological interface states in local resonant gaps is a question. In this
article, we study the topological bands near local resonant gaps in a
time-reversal symmetric acoustic systems and elaborate the evolution of band
structure using a spring-mass model. Our acoustic structure can produce three
band gaps in subwavelength region: one originates from local resonance of unit
cell and the other two stem from band folding. It is found that the topological
interface states can only exist in the band folding induced band gaps but never
appear in the local resonant band gap. The numerical simulation perfectly
agrees with theoretical results. Our study provides an approach of localizing
the subwavelength acoustic wave.",1712.04252v1
2017-12-20,The planar Multipole Resonance Probe: a functional analytic approach,"Active Plasma Resonance Spectroscopy (APRS) is a well known diagnostic
method, where a radio frequency probe is immersed into a plasma and excites
plasma oscillations. The response of the plasma is recorded as frequency
dependent spectrum, in which resonance peaks occur. By means of a mathematical
model plasma parameters like the electron density or the electron temperature
can be determined from the detected resonances. The majority of all APRS probes
have in common, that they are immersed into the plasma and perturb the plasma
due to the physical presence of the probe. To overcome this problem, the planar
Multipole Resonance Probe (pMRP) was invented, which can be integrated into the
chamber wall of a plasma reactor. Within this paper, the first analytic model
of the pMRP is presented, which is based on a cold plasma description of the
electrons. The general admittance of the probe-plasma system is derived by
means of functional analytic methods and a complete orthonormal set of basis
functions. Explicit spectra for an approximated admittance including a
convergence study are shown. The determined resonance frequencies are in good
agreement with former simulation results.",1712.07737v1
2017-12-26,High-speed quantum transducer with a single-photon emitter in a 2D resonator,"Quantum transducers can transfer quantum information between different
systems. Microwave-optical photon conversion is important for future quantum
networks to interconnect remote superconducting quantum computers with optical
fibers. Here we propose a high-speed quantum transducer based on a
single-photon emitter in an atomically thin membrane resonator that can couple
single microwave photons to single optical photons. The 2D resonator is a
freestanding van der Waals heterostructure (may consist of hexagonal boron
nitride, graphene, or other 2D materials) that hosts a quantum emitter. The
mechanical vibration (phonon) of the 2D resonator interacts with optical
photons by shifting the optical transition frequency of the single-photon
emitter with strain or the Stark effect. The mechanical vibration couples to
microwave photons by shifting the resonant frequency of a LC circuit that
includes the membrane. Thanks to the small mass of the 2D resonator, both the
single-photon optomechanical coupling strength and the electromechanical
coupling strength can reach strong coupling regimes. This provides a way for
high-speed quantum state transfer between a microwave photon, a phonon, and an
optical photon.",1712.09245v2
2018-01-23,Photo- and electroproduction of $K^{+}Λ$ with unitarity-restored isobar model,"Exploiting the isobar model, kaon photo- and electroproduction on the proton
in the resonance region comes under scrutiny. An upgrade of our previous model,
comprising higher-spin nucleon and hyperon exchanges in the consistent
formalism, was accomplished by implementing energy-dependent widths of nucleon
resonances, which leads to a different choice of hadron form factor with much
softer values of cutoff parameter for the resonant part. For a reliable
description of electroproduction, the necessity of including longitudinal
couplings of nucleon resonances to virtual photons was revealed. We present a
new model whose free parameters were adjusted to photo- and electroproduction
data and which provides a reliable overall description of experimental data in
all kinematic regions. The majority of nucleon resonances chosen in this
analysis coincide with those selected in our previous analysis and also in the
Bayesian analysis with the Regge-plus-resonance model as the states
contributing to this process with the highest probability.",1801.07466v2
2018-09-07,Dynamic Fano resonances: From toy model to resonant Mie scattering,"Based on the substantial difference in the response time for the resonant and
background partitions at stepwise variations of the exiting signal, a simple
exactly integrable model describing the dynamic Fano resonance (DFRs) is
proposed. The model does not have any fitting parameters, may include any
number of resonant partitions and exhibits high accuracy. It is shown that at
the point of the destructive interference any sharp variation of the amplitude
of the excitation (no matter an increase or a decrease) gives rise to
pronounced ""flashes"" in the intensity of the output signal. In particular, the
flash should appear behind the trailing edge of the exciting pulse, when the
excitation is already over. The model is applied to explain the DFRs at the
light scattering by a dielectric cylinder with two resonant modes excited
simultaneously and exhibits the excellent agreement with the results of the
direct numerical integration of the Maxwell equations.",1809.02474v1
2018-09-17,High quality factor graphene-based 2D heterostructure mechanical resonator,"Ultralight mechanical resonators based on low-dimensional materials are well
suited as exceptional transducers of minuscule forces or mass changes. However,
the low dimensionality also provides a challenge to minimize resistive losses
and heating. Here, we report on a novel approach that aims to combine different
2D materials to tackle this challenge. We fabricated a heterostructure
mechanical resonator consisting of few layers of niobium diselenide (NbSe$_2$)
encapsulated by two graphene sheets. The hybrid membrane shows high quality
factors up to 245'000 at low temperatures, comparable to the best few-layer
graphene mechanical resonators. In contrast to few-layer graphene resonators,
the device shows reduced electrical losses attributed to the lower resistivity
of the NbSe$_2$ layer. The peculiar low temperature dependence of the intrinsic
quality factor points to dissipation over two-level systems which in turn relax
over the electronic system. Our high sensitivity readout is enabled by coupling
the membrane to a superconducting cavity which allows for the integration of
the hybrid mechanical resonator as a sensitive and low loss transducer in
future quantum circuits.",1809.06169v1
2018-10-15,Ridge Resonance: A new Resonance Phenomenon for Silicon Photonics Harnessing Bound States in the Continuum,"We present a new resonant behavior based on bound states in the continuum in
a guided wave silicon platform. The continuum has the form of a collimated beam
of light which is confined vertically in a TE mode of a silicon slab. The bound
state is a discrete TM mode of a ridge on the silicon slab. The coupling
between the slab and ridge modes results in a single sharp resonance at the
wavelength where they phase match. We experimentally demonstrate this
phenomenon on a silicon photonic chip using foundry compatible parameters and
interface it on-chip to standard single mode silicon nanowire waveguides. The
fabricated chip exhibits a single sharp resonance near 1550 nm with a line
width of a few nanometer, an extinction ratio of 25 dB and a thermal stability
of 19.5 pm/C. We believe that this is the first demonstration of bound states
in the continuum resonance realized using guided wave components.",1810.06734v3
2018-10-23,Skyrme functional with tensor terms from \textit{ab initio} calculations of neutron-proton drops,"A new Skyrme functional devised to account well for standard nuclear
properties as well as for spin and spin-isospin properties is presented. The
main novelty of this work relies on the introduction of tensor terms guided by
\textit{ab initio} relativistic Brueckner-Hartree-Fock calculations of
neutron-proton drops. The inclusion of tensor term does not decrease the
accuracy in describing bulk properties of nuclei, experimental data of some
selected spherical nuclei such as binding energies, charge radii, and
spin-orbit splittings can be well fitted. The new functional is applied to the
investigation of various collective excitations such as the Giant Monopole
Resonance (GMR), the Isovector Giant Dipole Resonance (IVGDR), the Gamow-Teller
Resonance (GTR), and the Spin-Dipole Resonance (SDR). The overall description
with the new functional is satisfactory and the tensor terms are shown to be
important particularly for the improvement of the Spin-Dipole Resonance
results. Predictions for the neutron skin thickness based on the non-energy
weighted sum rule of the Spin-Dipole Resonance are also given.",1810.09691v2
2018-10-25,Perturbations of the scattering resonances of an open cavity by small particles. Part II: The transverse electric polarization case,"This paper is concerned with the scattering resonances of open cavities. It
is a follow-up of ""Perturbation of the scattering resonances of an open cavity
by small particles. Part I"" where the transverse magnetic polarization was
assumed. In that case, using the method of matched asymptotic expansions, the
leading-order term in the shifts of scattering resonances due to the presence
of small particles of arbitrary shapes was derived and the effect of radiation
on the perturbations of open cavity modes was characterized. The derivations
were formal.
  In this paper, we consider the transverse electric polarization and prove a
small-volume formula for the shifts in the scattering resonances of a radiating
dielectric cavity perturbed by small particles. We show a strong enhancement in
the frequency shift in the case of plasmonic particles. We also consider
exceptional scattering resonances and perform small-volume asymptotic analysis
near them. Our method in this paper relies on pole-pencil decompositions of
volume integral operators.",1810.10785v1
2018-10-30,Relaxation and hysteresis near Shapiro resonances in a driven spinor condensate,"We study the coherent and dissipative aspects of a driven spin-1
Bose-Einstein condensate (BEC) when the Zeeman energy is modulated around a
static bias value. Resonances appear when the bias energy matches an integer
number of modulation quanta. They constitute the atomic counterpart of Shapiro
resonances observed in microwave-driven superconducting Josephson junctions.
The population dynamics near each resonance corresponds to slow and non-linear
secular oscillations on top of a rapid `micromotion'. At long times and in a
narrow window of modulation frequencies around each resonance, we observe a
relaxation to asymptotic states that are unstable without drive. These
stationary states correspond to phase-locked solutions of the Josephson
equations generalized to include dissipation, and are analogous to the
stationary states of driven superconducting junctions. We find that dissipation
is essential to understand this long-time behavior, and we propose a
phenomenological model to explain quantitatively the experimental results.
Finally, we demonstrate hysteresis in the asymptotic state of the driven spinor
BEC when sweeping the modulation frequency across a Shapiro resonance.",1810.12638v1
2018-10-30,Ultrasensitive Displacement Noise Measurement of Carbon Nanotube Mechanical Resonators,"Mechanical resonators based on a single carbon nanotube are exceptional
sensors of mass and force. The force sensitivity in these ultra-light
resonators is often limited by the noise in the detection of the vibrations.
Here, we report on an ultra-sensitive scheme based on a RLC resonator and a
low-temperature amplifier to detect nanotube vibrations. We also show a new
fabrication process of electromechanical nanotube resonators to reduce the
separation between the suspended nanotube and the gate electrode down to $\sim
150$~nm. These advances in detection and fabrication allow us to reach
$0.5~\mathrm{pm}/\sqrt{\mathrm{Hz}}$ displacement sensitivity. Thermal
vibrations cooled cryogenically at 300~mK are detected with a signal-to-noise
ratio as high as 17~dB. We demonstrate $4.3~\mathrm{zN}/\sqrt{\mathrm{Hz}}$
force sensitivity, which is the best force sensitivity achieved thus far with a
mechanical resonator. Our work is an important step towards imaging individual
nuclear spins and studying the coupling between mechanical vibrations and
electrons in different quantum electron transport regimes.",1810.12797v1
2019-06-04,Probing the Glashow resonance at electron-positron colliders,"The Glashow resonance is a rapid enhancement of the cross section for
scattering of electron antineutrinos on electrons at the $W^-$ boson production
threshold due to the $s$-channel contribution. This resonance is being searched
for at large volume neutrino detectors in which the reaction
$\bar\nu_ee^-\rightarrow W^-$ to be initiated by cosmic ray antineutrinos of
energies about 6.3 PeV. The relatively small neutrino flux reaching the Earth
together with the necessity of analyzing ultra-high-energy final states make
such searches challenging. We argue here that the Glashow resonance may
contribute to the process $e^+e^-\rightarrow~W^+W^-$. By extending the method
of the effective (equivalent) particles to the neutral leptons, we relate the
distribution of the effective neutrinos in the electron to the total cross
section for $e^+e^-\rightarrow~W^+W^-$. Our approach gives a good fit to
existing experimental data measured at the collider LEP at CERN and allows one
to interpret these measurements as an observation of the Glashow resonance. We
also discuss an advantage of future electron-positron colliders for probing the
resonance.",1906.01557v2
2019-06-20,Effects of spin-orbit coupling on the neutron spin resonance in iron-based superconductors,"The so-called neutron spin resonance consists of a prominent enhancement of
the magnetic response at a particular energy and momentum transfer upon
entering the superconducting state of unconventional superconductors. In the
case of iron-based superconductors, the neutron resonance has been extensively
studied experimentally, and a peculiar spin-space anisotropy has been
identified by polarized inelastic neutron scattering experiments. Here we
perform a theoretical study of the energy- and spin-resolved magnetic
susceptibility in the superconducting state with $ s_{+-} $-wave order
parameter, relevant to iron-pnictide and iron-chalcogenide superconductors. Our
model is based on a realistic bandstructure including spin-orbit coupling with
electronic Hubbard-Hund interactions included at the RPA level. Spin-orbit
coupling is taken into account both in the generation of spin-fluctuation
mediated pairing, as well as the numerical computation of the spin
susceptibility in the superconducting state. We find that spin-orbit coupling
and superconductivity in conjunction can reproduce the salient experimentally
observed features of the magnetic anisotropy of the neutron resonance. This
includes the possibility of a double resonance, the tendency for a $c$-axis
polarized resonance, and the existence of enhanced magnetic anisotropy upon
entering the superconducting phase.",1906.08566v1
2019-06-28,Multiple scattering enabled superdirectivity from a subwavelength ensemble of resonators,"An ensemble of resonators arranged on a sub-wavelength scale is usually
considered as a bulk effective medium, known as a metamaterial, and can offer
unusual macroscopic properties. Here, we take a different approach and limit
ourselves to the study of only a few number of such elementary components and
demonstrate that it still offers uncommon opportunities. Typically, thanks to
the multiple scattering and the phase shift that the resonances offer, we
observe fields that vary at scales completely independent of the wavelength in
freespace. By smartly tuning the resonance frequencies, we can design at will
the complex current distribution in those resonators. This way, we design a
superdirective antenna, {\it ie.} an antenna that is surprisingly more
directive than its size would foreshadow. This approach is verified numerically
and experimentally in the context of microwaves, but this applies to any
wave-field where sub-wavelength resonators exist.",1906.12301v1
2019-07-05,Magnetoquasistatic Resonances of Small Dielectric Objects,"A small dielectric object with positive permittivity may resonate when the
free-space wavelength is large in comparison with the object dimensions if the
permittivity is sufficiently high. We show that these resonances are described
by the magnetoquasistatic approximation of the Maxwell's equations in which the
normal component of the displacement current density field vanishes on the
surface of the particle. They are associated to values of permittivities and
frequencies for which source-free quasistatic magnetic fields exist, which are
connected to the eigenvalues of a magnetostatic integral operator. We present
the general physical properties of magnetoquasistatic resonances in dielectrics
with arbitrary shape. They arise from the interplay between the polarization
energy stored in the dielectric and the energy stored in the magnetic field.
Our findings improve the understanding of resonances in high-permittivity
dielectric objects and provide a powerful tool that greatly simplifies the
analysis and design of high index resonators.",1907.02950v2
2019-07-09,Single-photon pump by Cooper-pair splitting,"Hybrid quantum dot-oscillator systems have become attractive platforms to
inspect quantum coherence effects at the nanoscale. Here, we investigate a
Cooper-pair splitter setup consisting of two quantum dots, each linearly
coupled to a local resonator. The latter can be realized either by a microwave
cavity or a nanomechanical resonator. Focusing on the subgap regime, we
demonstrate that cross-Andreev reflection, through which Cooper pairs are split
into both dots, can efficiently cool down simultaneously both resonators into
their ground state. Moreover, we show that a nonlocal heat transfer between the
two resonators is activated when opportune resonance conditions are matched.
The proposed scheme can act as a heat-pump device with potential applications
in heat control and cooling of mesoscopic quantum resonators.",1907.04308v3
2019-07-12,Imaging localized plasmon resonances in vacancy doped Cu3-xP semiconductor nanocrystals with STEM-EELS,"Copper binary compounds are often intrinsic p-type semiconductors due to the
presence of Cu(I) vacancies, with corresponding hole carriers in the valence
band. If the free carrier concentration is high enough, localized plasmon
resonances can be sustained in nanocrystals, with frequencies in the infra-red
(<1 eV), with respect to the typical resonances seen in the visible range in
the case of metals (Ag, Au, ...). The localization of the resonances can be
demonstrated with scanning transmission electron energy loss spectroscopy
(STEM-EELS) by combining high spatial and high energy resolutions. Here we
demonstrate that Cu(I) vacancies can be directly measured from the STEM images
in Cu(3-x)P hexagonal nanocrystals. Two localized resonances can be seen from
STEM-EELS, which are in agreement with the resonances calculated from the
vacancy concentration obtained from the STEM.",1907.05722v1
2019-10-02,Superradiantly limited linewidth in complementary THz metamaterials on Si-membranes,"We study complementary double split ring THz resonators fabricated on a 10
mum thin Si-membrane. The linewidths of the fundamental LC-mode and dipolar
mode are drastically narrowing with increased resonator spacing. The extracted
decay rate of the LC-mode as a function of the resonator density shows a linear
dependence, evidencing a collective superradiant effect of the resonator array.
Furthermore, we show that a metamaterial can be designed for a low superradiant
broadening of the resonance at high resonator densities, i.e. in the
metamaterial condition. The use of a thin membrane as a substrate is crucial,
since it shifts the THz surface plasmon polaritons modes to much higher
frequencies, preventing them to couple to the LC mode and unveiling the
superradiant broadening mechanism for a large range of lattice spacings. At
higher frequencies, not interfering with the high Q LC-mode, other additional
modes, which we ascribe to photonic crystal modes, form in the Si-membrane. We
map the angle dependent band structure and show corresponding simulated
electric field distributions.",1910.00814v1
2019-10-07,Quantum chaos in Feshbach resonances of the ErYb system,"We investigate ultracold magnetic-field-assisted collisions in the so far
unexplored ErYb system. The nonsphericity of the Er atom leads to weakly
anisotropic interactions that provide the mechanism for Feshbach resonances to
emerge. The resonances are moderately sparsely distributed with a density of
$0.1\,{\rm G}^{-1}-0.3\,{\rm G}^{-1}$ and exhibit chaotic statistics
characterized by a Brody parameter $\eta \approx 0.5-0.7$. The chaotic
behaviour of Feshbach resonances is accompanied by strong mixing of magnetic
and rotational quantum numbers in near-threshold bound states. We predict the
existence of broad resonances at fields $<300\,{\rm G}$ that may be useful for
the precise control of scattering properties and magnetoassociation of ErYb
molecules. The high number of bosonic Er-Yb isotopic combinations gives many
opportunities for mass scaling of interactions. Uniquely, two isotopic
combinations have nearly identical reduced masses (differing by less than
$10^{-5}$ relative) that we expect to have strikingly similar Feshbach
resonance spectra, which would make it possible to experimentally measure their
sensitivity to hypothetical variations of proton-to-electron mass ratio.",1910.03077v1
2019-10-16,Relativistic Mean Motion Resonance,"Mean motion resonances are commonly seen in planetary systems, e.g., in the
formation of orbital structure of Jupiter's moons and the gaps in the rings of
Saturn. In this work we study their effects in fully relativistic systems. We
consider a model problem with two stellar mass black holes orbiting around a
supermassive black hole. By adopting a two time-scale expansion technique and
averaging over the fast varying orbital variables, we derive the effective
Hamiltonian for the slowly varying dynamical variables. The formalism is
illustrated with a n'_phi : n'_r : n_phi= 2:1:-2 resonance in Schwarzschild
spacetime, which naturally becomes the 3:2 resonance widely studied in the
Newtonian limit. We also derive the multi-body Hamiltonian in the
post-Newtonian regime, where the radial and azimuthal frequencies are different
because of the post-Newtonian precession. The capture and breaking conditions
for these relativistic mean motion resonances are also discussed. In
particular, pairs of stellar mass black holes surrounding the supermassive
black hole could be locked into resonances as they enter the LISA band, and
this would affect their gravitational wave waveforms.",1910.07337v1
2020-01-16,Real-space imaging of atomic-scale spin textures at nanometer distances,"Spin-polarized scanning tunneling microscopy (SP-STM) experiments on
ultrathin films with non-collinear spin textures demonstrate that resonant
tunneling allows for atomic-scale spin-sensitive imaging in real space at
tip-sample distances of up to 8 nm. Spin-polarized resonance states evolving
between the foremost atom of a magnetic probe tip and the opposed magnetic
surface atom are found to provide a loophole from the hitherto existing dilemma
of losing spatial resolution when increasing the tip-sample distance in a
scanning probe setup. Bias-dependent series of SP-STM images recorded via
resonant tunneling reveal spin sensitivity at resonance conditions, indicating
that the spin-polarized resonance states act as mediators for the spin contrast
across the nm-spaced vacuum gap. With technically feasible distances in the nm
regime, resonant tunneling in SP-STM qualifies for a spin-sensitive read-write
technique with ultimate lateral resolution in future spintronic applications.",2001.05799v1
2019-11-20,Thermodynamic Limit for Linear Harmonic Oscillator Resonance Frequency Measurement,"Thermodynamic fluctuations in mechanical resonators cause uncertainty in
their frequency measurement, fundamentally limiting performance of
frequency-based sensors. Recently, integrating nanophotonic motion readout with
micro- and nano-mechanical resonators allowed practical chip-scale sensors to
routinely operate near this limit in high-bandwidth measurements. However, the
exact and general expressions for either thermodynamic frequency measurement
uncertainty or efficient, real-time frequency estimators are not well
established, particularly for fast and weakly-driven resonators. Here, we
derive, and numerically validate, the Cramer-Rao lower bound (CRLB) and an
efficient maximum-likelihood estimator for the frequency of a classical linear
harmonic oscillator subject to thermodynamic fluctuations. For a fluctuating
oscillator without external drive, the frequency Allan deviation calculated
from simulated resonator motion data agrees with the derived CRLB $\sigma_f =
{1 \over 2\pi}\sqrt{\Gamma \over 2\tau}$ for averaging times $\tau$ below, as
well as above, the relaxation time $1\over\Gamma$. The CRLB approach is general
and can be extended to driven resonators, non-negligible motion detection
imprecision, as well as backaction from a continuous linear quantum
measurement.",2001.10612v1
2020-02-19,Generalized Maxwell projections for multi-mode network Photonics,"The design of optical resonant systems for controlling light at the nanoscale
is an exciting field of research in nanophotonics. While describing the
dynamics of systems with few resonances is a relatively well understood
problem, controlling the behavior of systems with many overlapping states is
considerably more difficult. In this work we formulate a form of time dependent
coupled mode theory based on complete and orthogonal modes, which project
Maxwell's dynamics into a set of spatio-temporal equations that retain both the
simplicity and the exactness of traditional coupled mode theory studied for
optical waveguides. We developed a fast and effective computational method that
extracts all the characteristics of a multi-mode resonant system, including the
full density of states, the modes quality factors, the mode resonances and
linewidths from a single first principle simulation. This approach can be used
to study both analytically and numerically the complex dynamics of systems with
many overlapping resonances in ensembles of resonators of any geometrical shape
defined in materials with arbitrary responses.",2002.08121v1
2020-04-02,Imaging through Fano-resonant dielectric metasurface governed by quasi-BIC,"Fano resonance has raised great attention in nanophotonics attributing to its
unique properties.In this work, we study the imaging function of Fano-resonant
silicon metasurfece governed by quasi-bound states in the continuum (BICs).
First, by breaking the in-plane symmetry of nanodisks, a symmetry-protected
quasi-BIC is excited with the emergence of a sharp Fano resonance. The near
field distributions, multipole contributions and radiation patterns of the
metasurface are performed to uncover the mechanism and characteristics of this
resonance. In addition, we investigate the imaging function of this
Fano-resonant metasurface assisted by phase-change material Ge_2Sb_2Te_5(GST).
Through selective modification of different units from a-GST to c-GST, the
produced transmitted image well reconstructs the target letter. Our finding may
provide a route to achieve efficient metasurface-based imaging and fast spatial
modulations.",2004.00882v1
2020-04-02,Resonant Asymmetric All-Dielectric Metasurface for Boosting Third-Harmonic Generation,"Resonant metasurfaces have received extensive attention due to their sharp
spectral feature and extraordinary field enhancement. In this work, by breaking
the in-plane symmetry of silicon nanopillars, we achieve a sharp Fano
resonance. The far-field radiation and near-field distribution of metasurfaces
are calculated and analyzed to further uncover the resonant performance of
metasurfaces. Moreover, the theoretical derivation and simulation exhibit an
inverse quadratic dependence of Q-factors on asymmetry parameters, revealing
that the resonance is governed by the symmetry-protected bound states in the
continuum. Finally we experimentally demonstrate the sharp resonance, and
employ it to effciently boost the third-harmonic generation. This enhancement
can be attributed to the strong optical intensity enhancement inside the
metasurface.",2004.01088v2
2020-04-13,Signal-background interference for digluon resonances at the Large Hadron Collider,"We study the interference between the amplitudes for $gg \rightarrow X
\rightarrow gg$, where $X$ is a new heavy digluon resonance, and the QCD
background $gg \rightarrow gg$, at the Large Hadron Collider. The interference
produces a large low-mass tail and a deficit of events above the resonance
mass, compared to the naive pure resonance peak. For a variety of different
resonance quantum numbers and masses, we evaluate the signal-background
interference contribution at leading order, including showering, hadronization,
and detector effects. The resulting new physics dijet mass distribution may
have a shape that appears, after QCD background fitting and subtraction, to
resemble an enhanced peak, a shelf, a peak/dip, or even a pure dip. We argue
that the true limits on new digluon resonances are likely to differ
significantly from the limits obtained when interference is neglected,
especially if the branching ratio to $gg$ is less than 1.",2004.06181v3
2020-04-14,Complex scaling spectrum using multiple avoided crossings at stabilization graph,"This study concerns finite basis set $\{\chi_k\}$ calculations of resonances
based on real scaling, $\chi_k(x)\to \chi_k(xe^{-\eta})$. I demonstrate that
resonance width is generally influenced by several neighboring quasi-discrete
continuum states. Based on this finding I propose a new method to calculate the
complex resonance energy together with several states of complex rotated
continuum. The theory is introduced for a one-dimensional model, then it is
applied for helium doubly excited resonance $2s^2$. The new method requires the
real spectrum (""stabilization graph"") for a sufficiently large interval of the
parameter $\eta$ on which the potential curve of the sought resonance gradually
meets several different quasi-continuum states. Diabatic Hamiltonian which
comprehends the resonance and the several quasi-continuum states participating
at the avoided crossings is constructed. As $\eta$ is taken to complex plane,
$\eta\to i\theta$, the corresponding part of the complex scaled spectrum is
obtained.",2004.06372v2
2020-12-01,Universal length dependence of tensile stress in nanomechanical string resonators,"We investigate the tensile stress in freely suspended nanomechanical string
resonators, and observe a material-independent dependence on the resonator
length. We compare strongly stressed sting resonators fabricated from four
different material systems based on amorphous silicon nitride, crystalline
silicon carbide as well as crystalline indium gallium phosphide. The tensile
stress is found to increase by approximately 50% for shorter resonators. We
establish a simple elastic model to describe the observed length dependence of
the tensile stress. The model accurately describes our experimental data. This
opens a perspective for stress-engineering the mechanical quality factor of
nanomechanical string resonators.",2012.00507v2
2020-12-16,Characterizing the temperature dependence of Fano-Feshbach resonances of Ultracold Polarized Thulium,"Recent studies demonstrated anomalous temperature shifts for some
Fano-Feshbach resonances of thulium atoms. These anomalies were explained by
the variation in light intensity in the optical dipole trap, which accompanied
changes in temperature. In addition, a temperature-related transformation of
the statistics of the interresonance spacing was demonstrated [1]. Here, we
analyze the shifts of isolated s- and d-type Fano-Feshbach resonances of
ultracold thulium atoms with temperature for a fixed depth of an optical dipole
trap. The measurements are consistent with the 3-body recombination-based
theory of the temperature-related resonance shift and enable the extraction of
the resonance parameters, particularly the magnetic moments of closed channel
states. This parameter and the known polarizability of the open channel enable
us to separate the contributions of the temperature and Stark shift to the
overall shift of the resonances and show the dominant role of the Stark effect
in the overall shift.",2012.09223v2
2020-12-21,Coherent mechanical noise cancellation and cooperativity competition in optomechanical arrays,"Studying the interplay between multiple coupled mechanical resonators is a
promising new direction in the field of optomechanics. Understanding the
dynamics of the interaction can lead to rich new effects, such as enhanced
coupling and multi-body physics. In particular, multi-resonator optomechanical
systems allow for distinct dynamical effects due to the optical cavity
coherently coupling mechanical resonators. Here, we study the mechanical
response of two SiN membranes and a single optical mode, and find that the
cavity induces a time delay between the local and cavity-transduced thermal
noises experienced by the resonators. This results in an optomechanical phase
lag that causes destructive interference, cancelling the mechanical thermal
noise by up to 20 dB in a controllable fashion, matching our theoretical
expectation. Based on the effective coupling between membranes, we further
propose, derive and measure a collective effect, cooperativity competition on
mechanical dissipation, whereby the linewidth of one resonator depends on the
coupling efficiency (cooperativity) of the other resonator.",2012.11733v2
2021-01-04,Resonances in $^{12}$C and $^{24}$Mg: what do we learn from a microscopic cluster theory?,"We discuss resonance properties in three-body systems, with examples on
$^{12}{\rm C}$ and $^{24}{\rm Mg}$. We use a microscopic cluster model, where
the generator coordinate is defined in the hyperspherical formalism. The
$^{12}{\rm C}$ nucleus is described by an $\alpha+\alpha+\alpha$ structure,
whereas $^{24}{\rm Mg}$ is considered as an $^{16}{\rm O}+\alpha+\alpha$
system. We essentially pay attention to resonances. We review various
techniques which may extend variational methods to resonances. We consider
$0^+$ and $2^+$ states in $^{12}{\rm C}$ and $^{24}{\rm Mg}$. We show that the
r.m.s. radius of a resonance is strongly sensitive to the variational basis.
This has consequences for the Hoyle state ($0^+_2$ state in $^{12}{\rm C}$)
whose radius has been calculated or measured in several works. In $^{24}{\rm
Mg}$, we identify two $0^+$ resonances slightly below the three-body threshold.",2101.00955v1
2021-01-13,Can Lèvy noise induce coherence and stochastic resonances in a birhythmic van der Pol system?,"The analysis of a birhythmic modified van der Pol type oscillator driven by
periodic excitation and L\`evy noise shows the possible occurrence of coherence
resonance and stochastic resonance. The frequency of the harmonic excitation in
the neighborhood of one of the limit cycles influences the coherence of the
dynamics on the time scale of intrawell oscillations. The autocorrelation
function, the power spectral density and the signal-to-noise-ratio used in this
analysis are shown to be maximized for an appropriate choice of the noise
intensity. A proper adjustment of the L\`evy noise intensity enhances the
output power spectrum of the system, that is, promotes stochastic resonance.
Thus, the robustness of the resonance, that seems to occur also in the presence
of nonstandard noise, is examined using standard measures. The initial
selection of the attractor seems to have an influence on the coherence, while
the skewness parameter of the L\`evy noise has not a notable impact on the
resonant effect.",2101.05023v1
2021-01-21,Exploring Topology of 1D Quasiperiodic Metastructures through Modulated LEGO Resonators,"We investigate the dynamics and topology of metastructures with
quasiperiodically modulated local resonances. The concept is implemented on a
LEGO beam featuring an array of tunable pillar-cone resonators. The versatility
of the platform allows the experimental mapping of the beam's Hofstadter-like
resonant spectrum, which is the first reported observation for an elastic
medium. The non-trivial spectral gaps are classified by evaluating the
integrated density of states of the bulk bands, which is experimentally
verified through the observation of topological edge states localized at the
boundaries. Results also show that the spatial location of the edge states can
be varied through the selection of the phase of the resonator's modulation law.
The presented results open new pathways for the design of metastructures with
novel functionalities going beyond those encountered in periodic media by
exploiting aperiodic patterning of local resonances and suggest a simple,
viable platform for the observation of a variety of topological phenomena.",2101.08810v1
2021-01-23,Analytical edge power loss at the lower hybrid resonance: comparison with ANTITER IV and application to ICRH systems,"In non-inverted heating scenarios, a lower hybrid (LH) resonance can appear
in the plasma edge of tokamaks. This resonance can lead to large edge power
deposition when heating in the ion cyclotron resonance frequency (ICRF) range.
In this paper, the edge power loss associated with this LH resonance is
analytically computed for a cold plasma description using an asymptotic
approach and analytical continuation. This power loss can be directly linked to
the local radial electric field and is then compared to the corresponding power
loss computed with the semi-analytical code ANTITER IV. This method offers the
possibility to check the precision of the numerical integration made in ANTITER
IV and gives insights in the physics underlying the edge power absorption.
Finally, solutions to minimize this edge power absorption are investigated and
applied to the case of ITER's ion cyclotron resonance heating (ICRH) launcher.
This study is also of direct relevance to DEMO.",2101.09503v1
2012-05-03,Multiphoton transitions in Josephson-junction qubits (Review Article),"Two basic physical models, a two-level system and a harmonic oscillator, are
realized on the mesoscopic scale as coupled qubit and resonator. The realistic
system includes moreover the electronics for controlling the distance between
the qubit energy levels and their populations and to read out the resonator's
state, as well as the unavoidable dissipative environment. Such rich system is
interesting both for the study of fundamental quantum phenomena on the
mesoscopic scale and as a promising system for future electronic devices. We
present recent results for the driven superconducting qubit-resonator system,
where the resonator can be realized as an LC circuit or a nanomechanical
resonator. Most of the results can be described by the semiclassical theory,
where a qubit is treated as a quantum two-level system coupled to the classical
driving field and the classical resonator. Application of this theory allows to
describe many phenomena for the single and two coupled superconducting qubits,
among which are the following: the equilibrium-state and weak-driving
spectroscopy, Sisyphus damping and amplification, Landau-Zener-St\""uckelberg
interferometry, the multiphoton transitions of both direct and ladder- type
character, and creation of the inverse population for lasing.",1205.0696v1
2012-05-11,Feshbach resonances in Cesium at Ultra-low Static Magnetic Fields,"We have observed Feshbach resonances for 133Cs atoms in two different
hyperfine states at ultra-low static magnetic fields by using an atomic
fountain clock. The extreme sensitivity of our setup allows for high
signal-to-noise-ratio observations at densities of only 2*10^7 cm^{-3}. We have
reproduced these resonances using coupled-channels calculations which are in
excellent agreement with our measurements. We justify that these are s-wave
resonances involving weakly-bound states of the triplet molecular Hamiltonian,
identify the resonant closed channels, and explain the observed multi-peak
structure. We also describe a model which precisely accounts for the
collisional processes in the fountain and which explains the asymmetric shape
of the observed Feshbach resonances in the regime where the kinetic energy
dominates over the coupling strength.",1205.2553v1
2017-05-05,Multi-frequency Spin Manipulation Using Rapidly Tunable Superconducting Coplanar Waveguide Microresonators,"In this work, we demonstrate the use of frequency-tunable superconducting
NbTiN coplanar waveguide microresonators for multi-frequency pulsed electron
spin resonance (ESR) experiments. By applying a bias current to the center pin,
the resonance frequency ($\sim$7.6 GHz) can be continuously tuned by as much as
95 MHz in 270 ns without a change in the quality factor of 3000 at 2K. We
demonstrate the ESR performance of our resonators by measuring donor spin
ensembles in silicon and show that adiabatic pulses can be used to overcome
magnetic field inhomogeneities and microwave power limitations due to the
applied bias current. We take advantage of the rapid tunability of these
resonators to manipulate both phosphorus and arsenic spins in a single pulse
sequence, demonstrating pulsed double electron-electron resonance (DEER). Our
NbTiN resonator design is useful for multi-frequency pulsed ESR and should also
have applications in experiments where spin ensembles are used as quantum
memories.",1705.02413v2
2017-05-13,The LHC mass limits for the $SU(2)_{L+R}$ vector resonance triplet of a strong extension of the Standard model,"In this paper, we derive the mass exclusion limits for the hypothetical
vector resonances of a strongly interacting extension of the Standard model
using the most recent upper bounds on the cross sections for various resonance
production processes. The $SU(2)_{L+R}$ triplet of the vector resonances under
consideration is embedded into the effective Lagrangian based on the non-linear
sigma model with the $125$-GeV $SU(2)_{L+R}$ scalar singlet. No direct
interactions of the vector resonance to the SM fermions are assumed. We find
that among eleven processes considered in this paper only those where the
vector resonances decay to $WW$ and $WZ$ provide the mass exclusion limit.
Depending on the values of other parameters of the model the mass limit can be
as low as 1 TeV.",1705.04806v1
2017-05-24,Dynamics of an ultra-strongly-coupled system interacting with a driven nonlinear resonator,"In the ultra-strong coupling regime of a light-matter system, the ground
state exhibits non-trivial entanglement between the atom and photons. For the
purposes of exploring the measurement and control of this ground state, here we
analyze the dynamics of such an ultra-strongly-coupled system interacting with
a driven nonlinear resonator acting as a measurement apparatus. Interestingly,
although the coupling between the atom and the nonlinear resonator is much
smaller than the typical energy scales of the ultra-strongly-coupled system, we
show that we can generate a strong correlation between the nonlinear resonator
and the light-matter system. A subsequent coarse- grained measurement on the
nonlinear resonator significantly affects the light-matter system, and the
phase of the light changes depending on the measurement results. Also, we
investigate the conditions for when the nonlinear resonator can be entangled
with the ultra-strongly coupled system, which is the mechanism that allows us
to project the ground state of the ultra-strongly coupled system into a
non-energy eigenstate.",1705.08688v2
2017-05-31,Vacuum-induced Autler-Townes splitting in a superconducting artificial atom,"We experimentally study a vacuum-induced Autler-Townes doublet in a
superconducting three-level artificial atom strongly coupled to a coplanar
waveguide resonator and simultaneously to a transmission line. The
Autler-Townes splitting is observed in the reflection spectrum from the
three-level atom in a transition between the ground state and the second
excited state when the transition between the two excited states is resonant
with a resonator. By applying a driving field to the resonator, we observe a
change in the regime of the Autler-Townes splitting from quantum
(vacuum-induced) to classical (with many resonator photons). Furthermore, we
show that the reflection of propagating microwaves in a transmission line could
be controlled by different frequency single photons in a resonator.",1705.11118v2
2017-09-05,Feshbach Loss Spectroscopy in an Ultracold $^{23}$Na and $^{40}$K Mixture,"We perform Feshbach spectroscopy in an ultracold mixture of $^{23}$Na and
$^{40}$K with different spin-state combinations. We have observed 24 new
interspecies Feshbach resonances at magnetic field up to 350 G. A full
coupled-channel calculation is performed to assign these resonances. Among
them, 12 resonances are identified as d-wave Feshbach resonances. These d-wave
Feshbach resonances are about 5 G systematically smaller than the predications
based on previous model potential. Taking into account these new experimental
results, we improve the Born-Oppenheimer potentials between Na and K, and
achieve good agreement between the theory and experiment for all the observed
Feshbach resonances.",1709.01260v1
2017-09-11,"Coherence resonance in a network of FitzHugh-Nagumo systems: interplay of noise, time-delay and topology","We systematically investigate the phenomena of coherence resonance in
time-delay coupled networks of FitzHugh-Nagumo elements in the excitable
regime. Using numerical simulations, we examine the interplay of noise,
time-delayed coupling and network topology in the generation of coherence
resonance. In the deterministic case, we show that the delay-induced dynamics
is independent of the number of nearest neighbors and the system size. In the
presence of noise, we demonstrate the possibility of controlling coherence
resonance by varying the time-delay and the number of nearest neighbors. For a
locally coupled ring, we show that the time-delay weakens coherence resonance.
For nonlocal coupling with appropriate time-delays, both enhancement and
weakening of coherence resonance are possible.",1709.03336v1
2017-09-11,High Impedance Detector Arrays for Magnetic Resonance,"Resonant inductive coupling is commonly seen as an undesired fundamental
phenomenon emergent in densely packed resonant structures, such as nuclear
magnetic resonance phased array detectors. The need to mitigate coupling
imposes rigid constraints on the detector design, impeding performance and
limiting the scope of magnetic resonance experiments. Here we introduce a high
impedance detector design, which can cloak itself from electrodynamic
interactions with neighboring elements. We verify experimentally that the high
impedance detectors do not suffer from signal-to-noise degradation mechanisms
observed with traditional low impedance elements. Using this new-found
robustness, we demonstrate an adaptive wearable detector array for magnetic
resonance imaging of the hand. The unique properties of the detector glove
reveal new pathways to study the biomechanics of soft tissues, and exemplify
the enabling potential of high-impedance detectors for a wide range of
demanding applications that are not well suited to traditional coil designs.",1709.03416v1
2017-11-09,Quantum routing of single photons with whispering-gallery resonators,"Quantum routing of single photons in a system with two waveguides coupled to
two whispering-gallery resonators (WGRs) are investigated theoretically. With a
real-space full quantum theory, photonic scattering amplitudes along four ports
of the waveguide network are analytically obtained. It is shown that, by
adjusting the geometric and physical parameters of the two-WGR configuration,
the quantum routing properties of single photons along the present waveguide
network can be controlled effectively. For example, the routing capability from
input waveguide to another one can significantly exceed 0.5 near the resonance
point of scattering spectra, which can be achieved with only one resonator. By
properly designing the distance between two WGRs and the waveguide-WGR coupling
strengths, the transfer rate between the waveguides can also reach certain
sufficiently high values even in the non-resonance regime. Moreover, Fano-like
resonances in the scattering spectra are designable. The proposed system may
provide a potential application in controlling single-photon quantum routing as
a novel router.",1711.03279v1
2017-11-20,"Borromean Feshbach resonance in 11Li studied via 11Li(p,p')","A dipole resonance of 11Li is newly found by a 9Li + n + n three-body model
analysis with the complex-scaling method. The resonance can be interpreted as a
bound state in the 10Li + n system, that is, a Feshbach resonance in the 9Li +
n + n system. As a characteristic feature of the Feshbach resonance of 11Li,
the 10Li + n threshold is open above the 9Li + n + n one, which reflects a
distinctive property of the Borromean system. A microscopic four-body reaction
calculation for the 11Li(p,p') reaction at 6 MeV/nucleon is performed by taking
into account the resonance and nonresonant continuum states of the three-body
system. The angular distribution of the elastic and inelastic scattering as
well as the breakup energy spectrum recently observed are reproduced well.",1711.07209v2
2017-11-26,On local and global aspects of the 1:4 resonance in the conservative cubic Hénon maps,"We study the 1:4 resonance for the conservative cubic H\'enon maps
$\mathbf{C}_\pm$ with positive and negative cubic term. These maps show up
different bifurcation structures both for fixed points with eigenvalues $\pm i$
and for 4-periodic orbits. While for $\mathbf{C}_-$ the 1:4 resonance unfolding
has the so-called Arnold degeneracy (the first Birkhoff twist coefficient
equals (in absolute value) to the first resonant term coefficient), the map
$\mathbf{C}_+$ has a different type of degeneracy because the resonant term can
vanish. In the last case, non-symmetric points are created and destroyed at
pitchfork bifurcations and, as a result of global bifurcations, the 1:4
resonant chain of islands rotates by $\pi/4$. For both maps several
bifurcations are detected and illustrated.",1711.09447v1
2018-03-14,Cross Feshbach resonance,"Feshbach resonance occurs when a pair of free particles is resonantly coupled
to a molecular bound state. In the field of ultracold quantum gases, atomic
Feshbach resonances became a usual tool for tailoring atomic interactions
opening up many new applications in this field. In a semiconductor microcavity,
the Feshbach resonance appears when two lower polaritons are coupled to the
molecular biexciton state. Here, we demonstrate the existence of a cross
Feshbach resonance for which a pair of polaritons, lower together with upper,
effectively couples to the biexciton state. This demonstration is a crucial
step towards the efficient generation of entangled photon pairs in a
semiconductor microcavity. The existence of a Cross Feshbach resonance
establishes the condition to convert a pair of upper and lower polaritons via
the biexciton state into two lower polaritons, paving the way for the
generation of momentum and polarization entangled photons.",1803.05183v1
2018-07-02,Tunable Nb superconducting resonators based upon a Ne-FIB-fabricated constriction nanoSQUID,"Hybrid superconducting--spin systems offer the potential to combine highly
coherent atomic quantum systems with the scalability of superconducting
circuits. To fully exploit this potential requires a high quality-factor
microwave resonator, tunable in frequency and able to operate at magnetic
fields optimal for the spin system. Such magnetic fields typically rule out
conventional Al-based Josephson junction devices that have previously been used
for tunable high-$Q$ microwave resonators. The larger critical field of niobium
(Nb) allows microwave resonators with large field resilience to be fabricated.
Here, we demonstrate how constriction-type weak links, patterned in parallel
into the central conductor of a Nb coplanar resonator using a neon focused ion
beam (FIB), can be used to implement a frequency-tunable resonator. We study
transmission through two such devices and show how they realise high quality
factor, tunable, field resilient devices which hold promise for future
applications coupling to spin systems.",1807.00582v2
2018-07-06,Independently tunable dual-spectral electromagnetically induced transparency in a terahertz metal-graphene metamaterial,"We theoretically investigate the interaction between the conductive graphene
layer with the dual-spectral electromagnetically induced transparency (EIT)
metamaterial and achieve independent amplitude modulation of the transmission
peaks in terahertz (THz) regime. The dual-spectral EIT resonance results from
the strong near field coupling effects between the bright cut wire resonator
(CWR) in the middle and two dark double-split ring resonators (DSRRs) on the
two sides. By integrating monolayer graphene under the dark mode resonators,
the two transmission peaks of the EIT resonance can exhibit independent
amplitude modulation via shifting the Fermi level of the corresponding graphene
layer. The physical mechanism of the modulation can be attributed to the
variation of damping factors of the dark mode resonators arising from the
tunable conductivity of graphene. This work shows great prospects in designing
multiple-spectral THz functional devices with highly flexible tunability and
implies promising applications in multi-channel selective switching, modulation
and slow light.",1807.02240v1
2018-07-19,Clarifying the relationship between efficiency and resonance for flexible inertial swimmers,"We study a linear inviscid model of a passively flexible swimmer, calculating
its propulsive performance, eigenvalues, and eigenfunctions with an eye towards
clarifying the relationship between efficiency and resonance. The frequencies
of actuation and stiffness ratios we consider span a large range, while the
mass ratio is mostly fixed to a low value representative of swimmers. We
present results showing how the trailing edge deflection, thrust coefficient,
power coefficient, and efficiency vary in the stiffness-frequency plane. The
trailing edge deflection, thrust coefficient, and power coefficient show sharp
ridges of resonant behaviour for mid-to-high frequencies and stiffnesses,
whereas the efficiency does not show resonant behaviour anywhere. For low
frequencies and stiffnesses, the resonant peaks smear together and the
efficiency is high. In this region, flutter modes emerge, inducing travelling
wave kinematics which make the swimmer more efficient. We also consider the
effects of a finite Reynolds number in the form of streamwise drag. The drag
adds an offset to the net thrust produced by the swimmer, causing resonant
peaks to appear in the efficiency (as observed in experiments in the
literature).",1807.07499v1
2018-07-25,Unusual suppression of a spin resonance mode with magnetic field in underdoped NaFe$_{1-x}$Co$_x$As: Evidence for orbital-selective pairing,"We use inelastic neutron scattering to study the fate of the two spin
resonance modes in underdoped superconducting NaFe$_{1-x}$Co$_x$As ($x=0.0175$)
under applied magnetic fields. While an applied in-plane magnetic field of
$B=12$ T only modestly suppresses superconductivity and enhances static
antiferromagnetic order, the two spin resonance modes display disparate
responses. The spin resonance mode at higher energy is mildly suppressed,
consistent with the field effect in other unconventional superconductors. The
spin resonance mode at lower energy, on the other hand, is almost completely
suppressed. Such dramatically different responses to applied magnetic field
indicate distinct origins of the two spin resonance modes, resulting from the
strongly orbital-selective nature of spin excitations and Cooper-pairing in
iron-based superconductors.",1807.09669v1
2018-07-30,Observation of magnetically tunable Feshbach resonances in ultracold $^{23}$Na$^{40}$K+$^{40}$K collisions,"Resonances in ultracold collisions involving heavy molecules are difficult to
understand, and have proven challenging to detect. Here we report the
observation of magnetically tunable Feshbach resonances in ultracold collisions
between $^{23}$Na$^{40}$K molecules in the rovibrational ground state and
$^{40}$K atoms. We prepare the atoms and molecules in various hyperfine levels
of their ground states and observe the loss of molecules as a function of the
magnetic field. The atom-molecule Feshbach resonances are identified by
observing an enhancement of the loss rate coefficients. We have observed three
resonances at approximately 101 G in various atom-molecule scattering channels,
with the widths being a few hundred milliGauss. The observed atom-molecule
Feshbach resonances at ultralow temperatures probe the three-body potential
energy surface with an unprecedented resolution. Our work will help to improve
the understanding of complicated ultracold collisions, and open up the
possibility of creating ultracold triatomic molecules.",1807.11160v1
2018-08-20,"Modal Expansion of the Scattered Field: Causality, Non-Divergence and Non-Resonant Contribution","Modal analysis based on the quasi-normal modes (QNM), also called resonant
states, has emerged as a promising way for modeling the resonant interaction of
light with open optical cavities. However, the fields associated with QNM in
open photonic cavities diverge far away from the scatterer and the possibility
of expanding the scattered field with resonant contributions only has not been
established. Here, we address these two issues while restricting our study to
the case of a dispersionless spherical scatterer. First, we derive the rigorous
pole expansion of the $T$-matrix coefficients that link the scattered to the
incident fields associated with an optical resonator. This expansion evinces
the existence of a non-resonant term. Second, in the time domain, the causality
principle allows us to solve the problem of divergence and to derive a modal
expansion of the scattered field that does not diverge far from the scatterer.",1808.06443v1
2018-12-03,Topologically Enabled Ultra-high-Q Guided Resonances Robust to Out-of-plane Scattering,"Due to their ability to confine light, optical resonators are of great
importance to science and technology, yet their performances are often limited
by out-of-plane scattering losses from inevitable fabrication imperfections.
Here, we theoretically propose and experimentally demonstrate a class of guided
resonances in photonic crystal slabs, where out-of-plane scattering losses are
strongly suppressed due to their topological nature. Specifically, these
resonances arise when multiple bound states in the continuum - each carrying a
topological charge - merge in the momentum space and enhance the quality
factors of all resonances nearby. We experimentally achieve quality factors as
high as $4.9\times 10^5$ based on these resonances in the telecommunication
regime, which is 12-times higher than ordinary designs. We further show this
enhancement is robust across the samples we fabricated.Our work paves the way
for future explorations of topological photonics in systems with open boundary
condition and their applications in improving optoelectronic devices in
photonic integrated circuits.",1812.00892v1
2018-12-16,Gravitational resonances in mimetic thick branes,"In this work, we investigate gravitational resonances in both single and
double mimetic thick branes, which can provide a new way to detect the extra
dimension. For the single brane model, we apply the relative probability
proposed in [Phys. Rev. D. 80 (2009) 065019]. For the double brane model, we
investigate the resonances quasi-localized on the double brane, on the
sub-branes and between the sub-branes, respectively. To investigate the
resonances quasi-localized on the double brane, we introduce two different
definitions of the relative probability and find that the corresponding mass
spectra of gravitational resonances are almost the same. For the gravitational
resonances quasi-localized on sub-branes and between the sub-branes, the
influence of the distance between the two sub-branes and the thickness of the
sub-branes are analyzed and new features are found in both cases.",1812.06453v2
2018-12-19,Coherent interplay between surface acoustic waves and coupled mechanical resonators: transition from plasmon-like to surface mediated coupling,"Manipulation of mechanical motion at the micro-scale has been attracting
continuous attention, leading to the successful implementation of various
strategies with potential impact on classical and quantum information
processing. We here propose an approach based on the interplay between a pair
of localized mechanical resonators and travelling surface acoustic waves (SAW).
We demonstrate the existence of a two-sided interaction, allowing to use SAW to
trigger and control the resonator oscillation, and to manipulate the elastic
energy distribution on the substrate through resonator coupling. Observation of
the vectorial structure of the resonator motion reveals the existence of two
coupling regimes, a dipole-dipole-like interaction at small separation distance
versus a surface-mediated mechanical coupling at larger separation. These
results illustrate the potential of this platform for coherent control of
mechanical vibration at a resonator level, and reciprocally for manipulating
SAW propagation using sub-wavelength elements.",1812.07952v2
2018-12-20,Amplitude dependence of resonance frequency and its consequences for scanning probe microscopy,"With recent advances in scanning probe microscopy (SPM), it is now routine to
determine the atomic structure of surfaces and molecules while quantifying the
local tip-sample interaction potentials. Such quantitative experiments are
based on the accurate measurement of the resonance frequency shift due to the
tip-sample interaction. Here, we experimentally show that the resonance
frequency of oscillating probes used for SPM experiments change systematically
as a function of oscillation amplitude under typical operating conditions. This
change in resonance frequency is not due to tip-sample interactions, but rather
due to the cantilever strain or geometric effects and thus the resonance
frequency being a function of the oscillation amplitude. Our numerical
calculations demonstrate that the amplitude dependence of the resonance
frequency is an additional yet overlooked systematic error source that can
result nonnegligible errors in measured interaction potentials and forces. Our
experimental results and complementary numerical calculations reveal that the
frequency shift due to this amplitude dependence needs to be corrected even for
experiments with active oscillation amplitude control to be able to quantify
the tip-sample interaction potentials and forces with milli-electron volt and
pico-Newton resolutions.",1812.08818v1
2018-12-21,High-frequency stochastic switching of graphene resonators near room temperature,"Stochastic switching between the two bistable states of a strongly driven
mechanical resonator enables detection of weak signals based on probability
distributions, in a manner that mimics biological systems. However,
conventional silicon resonators at the microscale require a large amount of
fluctuation power to achieve a switching rate in the order of a few Hertz.
Here, we employ graphene membrane resonators of atomic thickness to achieve a
stochastic switching rate of 7.8 kHz, which is 200 times faster than current
state-of-the-art. The (effective) temperature of the fluctuations is
approximately 400 K, which is 3000 times lower than the state-of-the-art. This
shows that these membranes are potentially useful to transduce weak signals in
the audible frequency domain. Furthermore, we perform numerical simulations to
understand the transition dynamics of the resonator and derive simple
analytical expressions to investigate the relevant scaling parameters that
allow high-frequency, low-temperature stochastic switching to be achieved in
mechanical resonators.",1812.09295v1
2018-12-21,Heisenberg uncertainty relations for the non-Hermitian resonance state solutions to the Schrödinger equation,"Resonance (quasinormal) states correspond to non-Hermitian solutions to the
Schr\""odinger equation obeying outgoing boundary conditions which lead to
complex energy eigenvalues and momenta. Following the normalization rule for
resonance states obtained from the residue at a complex pole of the outgoing
Green's function to the problem, we propose a definition of expectation value
for these states and use it to investigate the extent of validity of the
Heisenberg uncertainty relations for potentials that vanish after a distance.
We derive analytical expressions for the expectation values involving the
momentum and the position for a given resonance state and find in model
calculations that the Heisenberg uncertainty relations are satisfied for a
broad range of potential parameters. A comparison of our approach with that
based on the regularization method by Zel'dovich yields very similar results
except for resonance energies very close to the energy threshold. Our work
shows that the validity of the Heisenberg uncertainty relations may be extended
to the non-Hermitian resonance state solutions to the Schr\""odinger equation.",1812.09319v2
2019-01-31,Fermion Localization and Degenerate Resonances on Brane Array,"In this work, we consider the multi-wall braneworld arisen from multi-scalar
fields, and investigate the localization and resonances of spin-1/2 fermion on
the multi-walls. We build two analytic multi-wall solutions with a polynomial
superpotential and a modified sine-Gordon superpotential respectively. The
massless fermion is the only bound state and localized between the two
outermost sub-branes. The factors affecting the number of massive resonant
fermions are analyzed. What interesting is that all the fermion resonant states
are non-degenerate for the cases of single- and two-walls, however,
doubly-degenerate fermion resonant states emerge for the cases of three- and
four-walls. This novel phenomenon could be potentially interesting in
phenomenology.",1901.11253v2
2019-02-01,Equilibrium trapping of cold atoms using dipole and radiative forces in an optical trap,"We report on highly effective trapping of cold atoms by a new method for a
stable single optical trap in the near-optical resonant regime. An optical trap
with the near-optical resonance condition consists of not only the dipole but
also the radiative forces, while a trap using a far-off resonance dominates
only the dipole force. We estimate a near-optical resonant trap for ultracold
rubidium atoms in the range between -0.373 and -2.23 THz from the resonance.
The time dependence of the trapped atoms indicates some difference of the
stable center-of-mass positions in the near-optical resonant trap, and also
indicates that the differences are caused by the change of the equilibrium
condition of the optical dipole and radiative forces. A stable position depends
only on laser detuning due to the change in the radiative force; however, the
position is ineffective against the change in the laser intensity, which
results in a change in the radiative force.",1902.00258v1
2019-02-20,Green's function method for the spin and pseudospin symmetries in the single-particle resonant states,"We investigate the spin and pseudospin symmetry in the single-particle
resonant states by solving the Dirac equation containing a Woods-Saxon
potential with Green's function method. Taking double-magic nucleus $^{208}$Pb
as an example, three spin doublets $3d$, $2h$, and $1j$ and three pseudospin
doublets $3\tilde{p}$, $1\tilde{i}$, and $1\tilde{j}$ are obtained for the
single-neutron resonant states. By analyzing the energy splittings, we find
that the threshold effect plays an important role in resonant pseudospin
doubles. Besides, there is a reversed level structure of pseudospin doublets in
the continuum. Differently, all the width splittings of either the spin
doublets or the pseudospin doublets are systematically positive and the
splittings are very small except $1\tilde{j}$ doublet. Further studies show
that the splittings of the energies and widths for the resonant (pseudo)spin
doublets are independent. Besides, the similarity properties of the wave
functions of the spin and pseudospin doublets still maintain well in resonant
states.",1902.07442v1
2019-02-26,Unconventional Cavity Optomechanics: Nonlinear Control of Phonons in the Acoustic Quantum Vacuum,"We study unconventional cavity optomechanics and the acoustic analogue of
radiation pressure to show the possibility of nonlinear coherent control of
phonons in the acoustic quantum vacuum. Specifically, we study systems where a
quantized optical field effectively modifies the frequency of an acoustic
resonator. We present a general method to enhance such a nonlinear interaction
by employing an intermediate qubit. Compared with conventional optomechanical
systems, the roles of mechanical and optical resonators are interchanged, and
the boundary condition of the phonon resonator can be modulated with an
ultrahigh optical frequency. These differences allow to test some quantum
effects with parameters which are far beyond the reach of conventional cavity
optomechanics. Based on this novel interaction form, we show that various
nonclassical quantum effects can be realized. Examples include an effective
method for modulating the resonance frequency of a phonon resonator (e.g., a
surface-acoustic-wave resonator), demonstrating mechanical parametric
amplification, and the dynamical Casimir effect of phonons originating from the
acoustic quantum vacuum. Our results demonstrate that unconventional
optomechanics offers a versatile hybrid platform for quantum engineering of
nonclassical phonon states in quantum acoustodynamics.",1902.09910v2
2019-02-27,Nuclear magnetic resonance spectroscopy as a dynamical structural probe of high pressure hydrogen,"An unambiguous crystallographic structure solution for the observed phases
II-VI of high pressure hydrogen does not exist due to the failure of standard
structural probes at extreme pressure. In this work we propose that nuclear
magnetic resonance spectroscopy provides a complementary structural probe for
high pressure hydrogen. We show that the best structural models available for
phases II, III, and IV of high pressure hydrogen exhibit markedly distinct
nuclear magnetic resonance spectra which could therefore be used to
discriminate amongst them. As an example, we demonstrate how nuclear magnetic
resonance spectroscopy could be used to establish whether phase III exhibits
polymorphism. Our calculations also reveal a strong renormalisation of the
nuclear magnetic resonance response in hydrogen arising from quantum
fluctuations, as well as a strong isotope effect. As the experimental
techniques develop, nuclear magnetic resonance spectroscopy can be expected to
become a useful complementary structural probe in high pressure experiments.",1902.10721v2
2019-03-07,Transformation of the mechanical properties of materials by the geomagnetic resonance,"The strong geomagnetic influences on mechanical properties of crystals due to
their exposure to ultralow crossed magnetic fields, the Earth's field (approx.
50 microTesla) and the AC field (approx. 3 microTesla) in the electron
paramagnetic resonance scheme, are discussed. Resonance relaxation
displacements of dislocations in NaCl crystals are found both for a harmonic
pump field and for a pulse AC field of resonance duration approx. 0.5 microsec.
Resonant changes have been also detected in the microhardness of ZnO,
triglycine sulfate, and potassium acid phthalate crystals after their exposure
in the same EPR scheme. The both effects manifest new strongly anisotropic
properties. In particular, the frequency of the resonance is very sensitive to
the mutual orientation of the sample and the Earth's field. Physical mechanisms
and practical significance of the phenomenon are discussed.",1903.03013v1
2019-03-26,Plasmon Resonances and Tachyon Ghost Modes in Highly Conducting Sheets,"Plasmon-polariton modes in two-dimensional electron gases have a dual
field-matter nature that endows them with unusual properties when electrical
conductivity exceeds a certain threshold set by the speed of light. In this
regime plasmons display an interesting relation with tachyons, the hypothetical
faster-than-light particles. While not directly observable, tachyons directly
impact properties of plasmon modes. Namely, in the ``tachyon'' regime, plasmon
resonances remain sharp even when the carrier collision rate $\gamma$ exceeds
plasmon resonance frequency. Resonances feature a recurrent behavior as
$\gamma$ increases, first broadening and then narrowing and acquiring
asymmetric non-Lorentzian lineshapes with power-law tails extending into the
tachyon continuum $\omega>ck$. This unusual behavior can be linked to the
properties of tachyon poles located beneath $\omega>ck$ branch cuts in the
complex $\omega$ plane: as $\gamma$ grows, tachyon poles approach the light
cone and hybridize with plasmons. Narrow resonances persisting for
$\gamma>\omega$, along with the unusual density and temperature dependence of
resonance frequencies, provide clear signatures of the tachyon regime.",1903.10648v2
2018-12-21,Experimental and numerical investigation of photoacoustic resonator for solid samples,"The photoacoustic signal in a closed T-cell resonator is generated and
measured using laser based photoacoustic spectroscopy. The signal is modelled
using the amplitude mode expansion method, which is based on eigenmode
expansion and introduction of losses in form of loss factors. The measurement
reproduced almost all the calculated resonances from the numerical models with
fairly good agreement. The cause of the differences between the measured and
the simulated resonances are explained. In addition, the amplitude mode
expansion simulation model is established as a quicker and computationally less
demanding photoacoustic simulation alternative to the viscothermal model. The
resonance frequencies obtained from the two models deviate by less than 1.8%.
It was noted that the relative height of the amplitudes of the two models
depended on the location of the antinodes within the resonator.",1903.11388v1
2019-03-28,Self-organized synchronization of mechanically coupled resonators based on optomechanics gain-loss balance,"We investigate collective nonlinear dynamics in a blue-detuned optomechanical
cavity that is mechanically coupled to an undriven mechanical resonator. By
controlling the strength of the driving field, we engineer a mechanical gain
that balances the losses of the undriven resonator. This gain-loss balance
corresponds to the threshold where both coupled mechanical resonators enter
simultaneously into self-sustained limit cycle oscillations regime. Rich sets
of collective dynamics such as in-phase and out-of-phase synchronizations
therefore emerge, depending on the mechanical coupling rate, the optically
induced mechanical gain and spring effect, and the frequency mismatch between
the resonators. Moreover, we introduce the quadratic coupling that induces
enhancement of the in-phase synchronization. This work shows how phonon
transport can remotely induce synchronization in coupled mechanical resonator
array and opens up new avenues for metrology, communication, phonon-processing,
and novel memories concepts.",1903.12162v3
2019-04-16,Nucleon resonance contributions to unpolarised inclusive electron scattering,"The first CLAS12 experiments will provide high-precision data on inclusive
electron scattering observables at a photon virtuality $Q^2$ ranging from 0.05
GeV$^2$ to 12 GeV$^2$ and center-of-mass energies $W$ up to 4 GeV. In view of
this endeavour, we present the modeling of the resonant contributions to the
inclusive electron scattering observables. As input, we use the existing CLAS
electrocoupling results obtained from exclusive meson electroproduction data
off protons, and evaluate for the first time the resonant contributions based
on the experimental results on the nucleon resonance electroexcitation. The
uncertainties are given by the data and duly propagated through a Monte Carlo
approach. In this way, we obtain estimates for the resonant contributions,
important for insight into the nucleon parton distributions in the resonance
region and for the studies of quark-hadron duality.",1904.08016v1
2019-04-24,Pygmy resonances and symmetry energy,"I present a brief summary of the first three decades of studies of pygmy
resonances in nuclei and their relation to the symmetry energy of nuclear
matter. I discuss the first experiments and theories dedicated to study the
electromagnetic response in halo nuclei and how a low energy peak was initially
identified as a candidate for the pygmy resonance. This is followed by the
description of a collective state in medium heavy and heavy nuclei which was
definitely identified as a pygmy resonance. The role of the slope parameter of
the symmetry energy in determining the properties of neutron stars is stressed.
The theoretical and experimental information collected on pygmy resonances,
neutron skins, and the numerous correlations found with the slope parameter is
briefly reviewed.",1904.10628v2
2019-04-30,On the convergence of the normal form transformation in discrete Rossby and drift wave turbulence,"We study numerically the region of convergence of the normal form
transformation for the case of the Charney-Hasagawa-Mima (CHM) equation to
investigate whether certain finite amplitude effects can be described in normal
coordinates. We do this by taking a Galerkin truncation of four Fourier modes
making part of two triads: one resonant and one non-resonant, joined together
by two common modes. We calculate the normal form transformation directly from
the equations of motion of our reduced model, successively applying the
algorithm to calculate the transformation up to $7^\textrm{th}$ order to
eliminate all non-resonant terms, and keeping up to $8$-wave resonances. We
find that the amplitudes at which the normal form transformation diverge very
closely match with the amplitudes at which a finite-amplitude phenomenon called
$precession$ $resonance$ (Bustamante $et$ $al.$ 2014) occurs, characterised by
strong energy transfers. This implies that the precession resonance mechanism
cannot be explained using the usual methods of normal forms in wave turbulence
theory, so a more general theory for intermediate nonlinearity is required.",1904.13272v1
2019-08-01,Universal scaling behavior of resonant absorption,"Mode conversion and resonant absorption are crucial mechanisms for wave
transport and absorption. Scaling behavior of mode conversion or resonant
absorption is well-known for electromagnetic and MHD waves in planar geometry.
Our recent study showed that such a scaling behavior of resonant absorption
could also exist for coronal loop oscillations with cylindrical geometry, but
it was only tested for one density profile. Here we generalise our previous
study on the scaling behavior of resonant absorption by considering multiple
density profiles. Applying an invariant imbedding method to the ideal MHD wave
equations, we show that the scaling behavior also exists for these density
models. We thus generalise our earlier results and show that such a universal
scaling exists in cylindrical geometry, too. Given these results and the
earlier results in planar geometry, we formulate a hypothesis that a universal
scaling behavior exists regardless of the type of mode conversion or resonant
absorption.",1908.00214v1
2019-08-07,Performance Study of Strongly Coupled Magnetic Resonance,"Strongly Coupled Magnetic Resonance (SCMR) uses electromagnetic resonance in
order to efficiently transfer power wirelessly over mid-range distances. Since
the energy exchange capability of resonant objects higher than non-resonant
objects, strongly coupled systems are able to achieve more efficient energy
transfer than other wireless power transfer systems. The paper presents
detailed experimental and simulated analysis of the performance of the SCMR
system. A prototype of the SCMR system was implemented and experiments were
conducted to analyze the performance of the system. Finally, the resonant
frequency of the system was experimentally verified and the factors influencing
the wireless power transfer were also studied",1908.02541v2
2019-11-09,Perturbation theories for symmetry-protected bound states in the continuum on two-dimensional periodic structures,"On dielectric periodic structures with a reflection symmetry in a periodic
direction, there can be antisymmetric standing waves (ASWs) that are
symmetry-protected bound states in the continuum (BICs). The BICs have found
many applications, mainly because they give rise to resonant modes of extremely
large quality-factors ($Q$-factors). The ASWs are robust to symmetric
perturbations of the structure, but they become resonant modes if the
perturbation is non-symmetric. The $Q$-factor of a resonant mode on a perturbed
structure is typically $O(1/\delta^2)$ where $\delta$ is the amplitude of the
perturbation, but special perturbations can produce resonant modes with larger
$Q$-factors. For two-dimensional (2D) periodic structures with a 1D
periodicity, we derive conditions on the perturbation profile such that the
$Q$-factors are $O(1/\delta^4)$ or $O(1/\delta^6)$. For the unperturbed
structure, an ASW is surrounded by resonant modes with a nonzero Bloch wave
vector. For 2D periodic structures, the $Q$-factors of nearby resonant modes
are typically $O(1/\beta^2)$, where $\beta$ is the Bloch wavenumber. We show
that the $Q$-factors can be $O(1/\beta^6)$ if the ASW satisfies a simple
condition.",1911.03612v1
2019-11-20,Generating NOON states in circuit QED using multi-photon resonance in the presence of counter-rotating interactions,"The NOON states are valuable quantum resources, which have a wide range of
applications in quantum communication, quantum metrology, and quantum
information processing. Here we propose a fast, concise and reliable protocol
for deterministically generating the NOON states of two resonators coupled to a
single $\triangle$-type superconducting qutrit. In particular, we derive the
effective Hamiltonians at the multi-photon resonances by virtue of the strong
counter-rotating interaction between the resonator modes and the qutrit. Based
on these crucial effective Hamiltonians, our protocol simplifies the previous
ones using the single-photon resonance and consequently reduces the number of
operations for state preparation. To test the robustness of this protocol, we
analyze the effects from both the decoherence including dissipation and
dephasing and the crosstalk of resonator modes on the state fidelity through a
Lindblad master equation in the eigenstates of the full Hamiltonian.",1911.08754v1
2019-11-21,Low-energy isoscalar dipole response of heavy nuclei within kinetic model,"The low-energy isoscalar dipole response of heavy spherical nuclei is studied
by using a semiclassical model, based on the solution of the linearized Vlasov
kinetic equation for finite Fermi systems. In this translation-invariant model
the excitations of the center of mass motion are exactly separated from the
internal ones. The low-energy dipole strength function displays three resonance
structures in the energy region up to 15 MeV. Calculations of the velocity
fields associated with the resonance structures at the centroid energies show a
vortex (toroidal) character of two overlying resonances, while the origin of
the lowest isoscalar dipole resonance structure is related to the dipole
single-particle excitations. Its centroid energy is close to the minimum energy
of the dipole single-particle spectrum. The main toroidal resonance gives a
qualitative description of the low-energy isoscalar dipole resonance observed
in heavy spherical nuclei.",1911.09759v1
2019-11-27,Two paradigmatic scenarios for inverse stochastic resonance,"Inverse stochastic resonance comprises a nonlinear response of an oscillatory
system to noise where the frequency of noise-perturbed oscillations becomes
minimal at an intermediate noise level. We demonstrate two generic scenarios
for inverse stochastic resonance by considering a paradigmatic model of two
adaptively coupled stochastic active rotators whose local dynamics is close to
a bifurcation threshold. In the first scenario, shown for the two rotators in
the excitable regime, inverse stochastic resonance emerges due to a biased
switching between the oscillatory and the quasi-stationary metastable states
derived from the attractors of the noiseless system. In the second scenario,
illustrated for the rotators in the oscillatory regime, inverse stochastic
resonance arises due to a trapping effect associated with a noise-enhanced
stability of an unstable fixed point. The details of the mechanisms behind the
resonant effect are explained in terms of slow-fast analysis of the
corresponding noiseless systems.",1911.12113v2
2019-12-01,Study of microwave resonances induced by bias lines of shunted Josephson junctions,"Bias lines routed over a ground plane naturally form microstrip lines
associated with the presence of a capacitance. This can lead to unwanted
resonances when coupled to Josephson junctions. This work presents an
electrical model of a shunted Josephson junction with its bias lines and pads,
fabricated with the 1 kA/cm$^2$ RSFQ niobium process of the FLUXONICS Foundry.
A compact LCL T-model is used to simulate the microwave behavior of the bias
line, predict resonances and design resonance-free superconducting circuits.
The I-V characteristics of three shunted Josephson junctions have been obtained
from time-domain simulations done with JSIM and show a good match with the
global behavior and experimentally observed resonance at 230 GHz, measured at
4.2 K. The influence of the position and value of a series resistor placed on
bias lines is studied to damp unwanted resonances at the junction.",1912.00503v2
2019-12-03,Multi-reflection model of subwavelength grating diffraction based on simplified modal method,"A multi-reflection model of grating diffraction based on the simplified modal
method is proposed. Simulation results for a guided mode resonance Brewster
grating using our method and rigorous coupled wave analysis are presented to
verify our model. The solution of our method is in good agreement with that of
rigorous coupled wave analysis. Benefiting from its clear physical view, this
model helps us to better understand the diffraction process inside
subwavelength gratings. On the basis of the multi-reflection model, we
developed a matrix Fabry-Perot (FP) resonance condition and a single-mode
resonance condition to evaluate the resonance wavelength. These resonance
conditions may be helpful for simplifying design of guided mode resonance (GMR)
gratings.",1912.01226v1
2020-03-02,Quantum Many-Body Theory for Exciton-Polaritons in Semiconductor Mie Resonators in the Non-Equilibrium,"We implement externally excited ZnO Mie resonators in a framework of a
generalized Hubbard Hamiltonian to investigate the lifetimes of excitons and
exciton-polaritons out of thermodynamical equilibrium. Our results are derived
by a Floquet-Keldysh-Green's formalism with Dynamical Mean Field Theory (DMFT)
and a second order iterative perturbation theory solver (IPT). We find that the
Fano resonance which originates from coupling of the continuum of electronic
density of states to the semiconductor Mie resonator yields polaritons with
lifetimes between 0.6 ps and 1.45 ps. These results are compared to ZnO
polariton lasers and to ZnO random lasers. We interpret the peaks of the
exciton-polariton lifetimes in our results as a sign of gain narrowing which
may lead to stable polariton lasing modes in the single excited ZnO Mie
resonator. This form of gain may lead to polariton random lasing in an ensemble
of ZnO Mie resonators in the non-equilibrium.",2003.00793v2
2020-03-16,Simulating Topological Robustness of Fano Resonance in Rotated Honeycomb Photonic Crystals,"The Fano resonance with a distinctive ultra-sharp, asymmetric line shape and
high quality factor Q, is a widely occurring phenomena that has a large variety
of optical, plasmonic and microwave manifestations. In this paper, we explore
the characteristic robustness of the Fano resonance mode, which is
topologically protected by manufacturing band inversion induced by breaking the
mirror symmetry of a two-dimensional honeycomb photonic crystal (HPC),
associated with C_6 point group symmetry. So the dark and bright topological
edge modes appear in the band gap made by opening of the Dirac cone.
Destructive and constructive interference of the dark and bright modes leads to
the asymmetric line shape of the Fano resonance. The Fano resonance mode which
is very sensitive to the environmental and geometrical perturbations, can be
applied to sensor design. Here we demonstrate that the topological Fano
resonance mode preserves its asymmetric, ultra-sharp line shape in the presence
of the disorder, defects and cavities, and this has useful optical device
applications such as in low threshold lasers, and extremely precise
interferometers",2003.07253v5
2020-03-23,Giant enhancement in the thermal responsivity of microelectromechanical resonators by internal mode coupling,"We report on a giant enhancement in the thermal responsivity of the
doubly-clamped GaAs microelectromechanical (MEMS) beam resonators by using the
internal mode coupling effect. This is achieved by coupling the fundamental
bending mode with the fundamental torsional mode of the MEMS beam resonators
through the cubic Duffing nonlinearity. In the mode coupling regime, we have
found that, when the input heat to the MEMS resonators is modulated at a
particular frequency, the resonance frequency shift caused by heating can be
enhanced by almost two orders of magnitude. The observed effect is promising
for realizing high-sensitivity thermal sensing by using MEMS resonators, such
as ultrasensitive terahertz detection at room temperature.",2003.10119v2
2020-06-02,Rigid body dynamics of diamagnetically levitating graphite resonators,"Diamagnetic levitation is a promising technique for realizing resonant
sensors and energy harvesters, since it offers thermal and mechanical isolation
from the environment at zero power. To advance the application of
diamagnetically levitating resonators, it is important to characterize their
dynamics in the presence of both magnetic and gravitational fields. Here we
experimentally actuate and measure rigid body modes of a diamagnetically
levitating graphite plate. We numerically calculate the magnetic field and
determine the influence of magnetic force on the resonance frequencies of the
levitating plate. By analyzing damping mechanisms, we conclude that eddy
current damping dominates dissipation in mm-sized plates. We use finite element
simulations to model eddy current damping and find close agreement with
experimental results. We also study the size-dependent Q-factors (Qs) of
diamagnetically levitating plates and show that Qs above 100 million are
theoretically attainable by reducing the size of the diamagnetic resonator down
to microscale, making these systems of interest for next generation low-noise
resonant sensors and oscillators.",2006.01733v3
2020-06-12,Fragile Many Body Ergodicity,"Weakly nonintegrable many-body systems can restore ergodicity in distinctive
ways depending on the range of the interaction network in action space. Action
resonances seed chaotic dynamics into the networks. Long range networks provide
well connected resonances with ergodization controlled by the individual
resonance chaos time scales. Short range networks instead yield a dramatic
slowing down of ergodization in action space, and lead to rare resonance
diffusion. We use Josephson junction chains as a paradigmatic study case. We
exploit finite time average distributions to characterize the thermalizing
dynamics of actions. We identify a novel action resonance diffusion regime
responsible for the slowing down. We extract the diffusion coefficient of that
slow process and measure its dependence on the proximity to the integrable
limit. Independent measures of correlation functions confirm our findings. The
observed fragile diffusion is relying on weakly chaotic dynamics in spatially
isolated action resonances. It can be suppressed, and ergodization delayed, by
adding weak action noise, as a proof of concept.",2006.07179v1
2020-06-25,Magnetometry using sodium fluorescence with synchronous modulation of two-photon resonant light fields,"We report a new technique for generating magnetic resonance with synchronous
modulation of two-photon resonant light fields. Magnetic resonances in
fluorescence from a sodium cell are measured to demonstrate suitability of this
technique for remote magnetometry. A strong magnetic resonance with its dip
corresponding to the Larmor frequency is produced in the presence of a
transverse magnetic field. An additional resonance at 3\{Omega_L} is observed,
which can be used to determine the magnetic field orientation. We have
developed a theoretical model based on the density matrix equations to verify
our experimental observations. An average magnetic field sensitivity of 41
\mathbf{pT}/\sqrt{\mathbf{Hz}} is measured using light duty cycles ranging from
35% to 10%. We have discussed possible changes that can be made to improve the
sensitivity of this scheme further.",2006.14647v2
2020-06-26,Surface acoustic wave coupling between micromechanical resonators,"The coupling of micro- or nanomechanical resonators via a shared substrate is
intensively exploited to built systems for fundamental studies and practical
applications. So far, the focus has been on devices operating in the kHz regime
with a spring-like coupling. At resonance frequencies above several 10 MHz,
wave propagation in the solid substrate becomes relevant. The resonators act as
sources for surface acoustic waves (SAWs) and it is unknown how this effects
the coupling between them. Here, we present a model for MHz frequency
resonators interacting by SAWs and derive the eigenfrequencies and quality
factors of a pair of resonators for the symmetric and antisymmetric mode. Our
results are in agreement with finite element method (FEM) simulations and show
that in contrast to the well-known strain-induced spring-like coupling, the
coupling via SAWs is not only dispersive but also dissipative. This can be
exploited to realize high quality phonon cavities, an alternative to acoustic
radiation shielding by, e.g. phononic crystals.",2006.14862v4
2020-06-30,$ΛΛN$-$ΞNN$ $S$ wave resonance,"We use an existing model of the $\Lambda\Lambda N - \Xi NN$ three-body system
based in two-body separable interactions to study the $(I,J^P)=(1/2,1/2^+)$
three-body channel. For the $\Lambda\Lambda$, $\Xi N$, and $\Lambda\Lambda -
\Xi N$ amplitudes we have constructed separable potentials based on the most
recent results of the HAL QCD Collaboration. They are characterized by the
existence of a resonance just below or above the $\Xi N$ threshold in the
so-called $H$-dibaryon channel, $(i,j^p)=(0,0^+)$. A three-body resonance
appears {2.3} MeV above the $\Xi d$ threshold. We show that if the
$\Lambda\Lambda - \Xi N$ $H$-dibaryon channel is not considered, the
$\Lambda\Lambda N - \Xi NN$ $S$ wave resonance disappears. Thus, the possible
existence of a $\Lambda\Lambda N - \Xi NN$ resonance would be sensitive to the
$\Lambda\Lambda - \Xi N$ interaction. The existence or nonexistence of this
resonance could be evidenced by measuring, for example, the $\Xi d$ cross
section.",2006.16567v1
2020-08-04,Tunable Graphene Split-Ring Resonators,"A split-ring resonator is a prototype of meta-atom in metamaterials. Though
noble metal-based split-ring resonators have been extensively studied, up to
date, there is no experimental demonstration of split-ring resonators made from
graphene, an emerging intriguing plasmonic material. Here, we experimentally
demonstrate graphene split-ring resonators with deep subwavelength (about one
hundredth of the excitation wavelength) magnetic dipole response in the
terahertz regime. Meanwhile, the quadrupole and electric dipole are
observed,depending on the incident light polarization. All modes can be tuned
via chemical doping or stacking multiple graphene layers. The strong
interaction with surface polar phonons of the SiO2 substrate also significantly
modifies the response. Finite-element frequency domain simulations nicely
reproduce experimental results. Our study moves one stride forward toward the
multi-functional graphene metamaterials, beyond simple graphene ribbon or disk
arrays with electrical dipole resonances only.",2008.01577v1
2020-08-04,Resonant spin amplification meets electron spin resonance in $n$-GaAs,"Periodic excitation of electron spin polarization by consecutive laser pulses
in phase with Larmor spin precession about a magnetic field results in resonant
spin amplification (RSA). We observe a drastic modification of RSA in $n$-doped
bulk GaAs under the influence of external oscillating magnetic field. We find a
double-peaked electron spin resonance instead of a single-peaked resonance
expected without optical pumping. The frequency splitting increases linearly
with amplitude of field oscillations, while the spin deviation increases
quadratically. Moreover, we show that the oscillating field can both
significantly suppress RSA and induce new conditions for resonance. Using
quaternions to describe spin rotations, we develop a theory that simultaneously
considers spin precession, decay, and amplification and reproduces the entire
set of the experimental data. Using the radio-frequency field allows one to
control the conditions of RSA and achieve fine tuning of average spin
polarization without modifying the parameters of optical pumping.",2008.01626v1
2020-08-08,Two-magnon frequency-pulling effect in ferromagnetic resonance,"We report the experimental observation in thin films of the hybridization of
the uniform ferromagnetic resonance mode with nonuniform magnons as a result of
the two-magnon scattering mechanism, leading to a frequency-pulling effect on
the ferromagnetic resonance. This effect, when not properly accounted for,
leads to a discrepancy in the dependence of the ferromagnetic resonance field
on frequency for different field orientations. The frequency-pulling effect is
the complement of the broadening of the ferromagnetic resonance lineshape by
two-magnon scattering and can be calculated using the same parameters. By
accounting for the two-magnon frequency shifts through these means, consistency
is achieved in fitting data from in-plane and perpendicular-to-plane resonance
conditions.",2008.03423v2
2020-08-17,Stability of superconducting resonators: motional narrowing and the role of Landau-Zener driving of two-level defects,"Frequency instability of superconducting resonators and qubits leads to
dephasing and time-varying energy-loss and hinders quantum-processor tune-up.
Its main source is dielectric noise originating in surface oxides. Thorough
noise studies are needed in order to develop a comprehensive understanding and
mitigation strategy of these fluctuations. Here we use a frequency-locked loop
to track the resonant-frequency jitter of three different resonator types---one
niobium-nitride superinductor, one aluminium coplanar waveguide, and one
aluminium cavity---and we observe strikingly similar random-telegraph-signal
fluctuations. At low microwave drive power, the resonators exhibit multiple,
unstable frequency positions, which for increasing power coalesce into one
frequency due to motional narrowing caused by sympathetic driving of individual
two-level-system defects by the resonator. In all three devices we probe a
dominant fluctuator, finding that its amplitude saturates with increasing drive
power, but its characteristic switching rate follows the power-law dependence
of quasiclassical Landau-Zener transitions.",2008.07038v1
2020-08-19,Gravitational resonances on $f(T)$-branes,"In this work, we investigate the gravitational resonances in various
$f(T)$-brane models with the warp factor
$\text{e}^{A(y)}=\tanh\big(k(y+b)\big)-\tanh\big(k(y-b)\big)$. For three kinds
of $f(T)$, we give the solutions to the system. Besides, we consider the tensor
perturbation of vielbein and obtain the effective potentials by the
Kaluza-Klein (KK) decomposition. Then, we analyze what kind of effective
potential can produce the gravitational resonances. Effects of different
parameters on the gravitational resonances are analysed. The lifetimes of the
resonances could be long enough as the age of our universe in some ranges of
the parameters. This indicates that the gravitational resonances might be
considered as one of the candidates of dark matter. Combining the current
experimental observations, we constrain the parameters for these brane models.",2008.08440v2
2020-08-24,Chromospheric resonances above sunspots and potential seismological applications,"Oscillations in sunspot umbrae exhibit remarkable differences between the
photosphere and chromosphere. We evaluate two competing scenarios proposed for
explaining those observations: a chromospheric resonant cavity and waves
traveling from the photosphere to upper atmospheric layers. We have employed
numerical simulations to analyze the oscillations in both models. They have
been compared with observations in the low (Na I D2) and high (He I 10830 \AA)
chromosphere. The nodes of the resonant cavity can be detected as phase jumps
or power dips, although the identification of the latter is not sufficient to
claim the existence of resonances. In contrast, phase differences between
velocity and temperature fluctuations reveal standing waves and unequivocally
prove the presence of an acoustic resonator above umbrae. Our findings offer a
new seismic method to probe active region chromospheres through the detection
of resonant nodes.",2008.10623v1
2020-09-09,Transfers of energy through fast diffusion channels in some resonant PDEs on the circle,"In this paper we consider two classes of resonant Hamiltonian PDEs on the
circle with non-convex (respect to actions) first order resonant Hamiltonian.
We show that, for appropriate choices of the nonlinearities we can find
time-independent linear potentials that enable the construction of solutions
that undergo a prescribed growth in the Sobolev norms. The solutions that we
provide follow closely the orbits of a nonlinear resonant model, which is a
good approximation of the full equation. The non-convexity of the resonant
Hamiltonian allows the existence of fast diffusion channels along which the
orbits of the resonant model experience a large drift in the actions in the
optimal time. This phenomenon induces a transfer of energy among the Fourier
modes of the solutions which in turn is responsible for the growth of higher
order Sobolev norms.",2009.04228v2
2020-09-09,List of the close asteroid pairs strongly perturbed by three body resonances,"The two and three body mean motion resonances with Jupiter and Mars (and
possible with Earth) may have significant effect on dynamics of very young
close asteroids pairs and families. The most known example is influence 9:16
resonance with Mars to some members of Datura family. It is evident, that
evolution of this family can be properly reconstructed only when this fact has
taken into account. Here we give the list of asteroid pairs in vicinity of mean
motion resonance. One of the results of resonance perturbation may be the
temporary compensation of the Yarkovsky drift in the semimajor axis. Evidently,
studying this relationship may very well prove to be a radically influential
factor in the age estimation of asteroid pairs and families. In this paper we
have given list of some close asteroid pairs in vicinity of mean motion
resonances.",2009.04523v1
2020-09-12,Inverse resonance scattering for massless Dirac operators on the real line,"We consider massless Dirac operators on the real line with compactly
supported potentials. We solve two inverse problems (including
characterization): in terms of zeros of reflection coefficient and in terms of
poles of reflection coefficients (i.e. resonances). We prove that a potential
is uniquely determined by zeros of reflection coefficients and there exist
distinct potentials with the same resonances. We describe the set of
""isoresonance potentials"". Moreover, we prove the following:
  1) a zero of the reflection coefficient can be arbitrarily shifted, such that
we obtain the sequence of zeros of the reflection coefficient for an other
compactly supported potential,
  2) the forbidden domain for resonances is estimated,
  3) asymptotics of resonances counting function is determined,
  4) these results are applied to canonical systems.",2009.07031v1
2020-10-02,Loss channels affecting lithium niobate phononic crystal resonators at cryogenic temperature,"We investigate the performance of microwave-frequency phononic crystal
resonators fabricated on thin-film lithium niobate for integration with
superconducting quantum circuits. For different design geometries at
millikelvin temperatures, we achieve mechanical internal quality factors $Q_i$
above $10^5 - 10^6$ at high microwave drive power, corresponding to
$5\times10^6$ phonons inside the resonator. By sweeping the defect size of
resonators with identical mirror cell designs, we are able to indirectly
observe signatures of the complete phononic bandgap via the resonators'
internal quality factors. Examination of quality factors' temperature
dependence shows how superconducting and two-level system (TLS) loss channels
impact device performance. Finally, we observe an anomalous low-temperature
frequency shift consistent with resonant TLS decay and find that material
choice can help to mitigate these losses.",2010.01025v3
2020-10-05,Resonant Energy Recycling SRAM Architecture,"Although we may be at the end of Moore's law, lowering chip power consumption
is still the primary driving force for the designers. To enable low-power
operation, we propose a resonant energy recovery static random access memory
(SRAM). We propose the first series resonance scheme to reduce the dynamic
power consumption of the SRAM operation. Besides, we identified the requirement
of supply boosting of the write buffers for proper resonant operation. We
evaluated the resonant 144KB SRAM cache through SPICE and test chip using a
commercial 28nm CMOS technology. The experimental results show that the
resonant SRAM can save up to 30% dynamic power at 1GHz operating frequency
compared to the state-of-the-art design.",2010.01767v1
2020-10-06,N-polar GaN/AlN resonant tunneling diodes,"N-polar GaN/AlN resonant tunneling diodes are realized on single-crystal
N-polar GaN bulk substrate by plasma-assisted molecular beam epitaxy growth.
The room-temperature current-voltage characteristics reveal a negative
differential conductance (NDC) region with a peak tunneling current of 6.8$\pm$
0.8 kA/cm$^2$ at a forward bias of ~8 V. Under reverse bias, the
polarization-induced threshold voltage is measured at ~$-$4 V. These resonant
and threshold voltages are well explained with the polarization field which is
opposite to that of the metal-polar counterpart, confirming the N-polarity of
the RTDs. When the device is biased in the NDC-region, electronic oscillations
are generated in the external circuit, attesting to the robustness of the
resonant tunneling phenomenon. In contrast to metal-polar RTDs, N-polar
structures have the emitter on the top of the resonant tunneling cavity. As a
consequence, this device architecture opens up the possibility of seamlessly
interfacing$-$via resonant tunneling injection$-$a wide range of exotic
materials with III-nitride semiconductors, providing a route to explore new
device physics.",2010.03079v1
2020-10-16,Constraining resonances by using the electroweak effective theory,"In the light of the mass gap between Standard Model (SM) states and possible
new particles, effective field theories are a suitable approach. We take on the
non-linear realization of the electroweak symmetry breaking: the electroweak
effective theory (EWET), also known as Higgs effective field theory (HEFT) or
electroweak chiral Lagrangian (EWChL). At higher scales we consider a resonance
electroweak Lagrangian, coupling SM fields to resonances. Integrating out these
resonances and assuming a well-behaved high-energy behavior, some of the
bosonic low-energy constants are determined or constrained in terms of
resonance masses. Present experimental bounds on these low-energy constants
allow us to push the resonance mass scale to the TeV range, $M_R \geq 2\,$TeV,
in good agreement with previous estimations.",2010.08271v1
2020-11-18,Coherence Resonance and Stochastic Resonance in an Excitable Semiconductor Superlattice,"Collective electron transport causes a weakly coupled semiconductor
superlattice under dc voltage bias to be an excitable system with $2N+2$
degrees of freedom: electron densities and fields at $N$ superlattice periods
plus the total current and the field at the injector. External noise of
sufficient amplitude induces regular current self-oscillations (coherence
resonance) in states that are stationary in the absence of noise. Numerical
simulations show that these oscillations are due to the repeated nucleation and
motion of charge dipole waves that form at the emitter when the current falls
below a critical value. At the critical current, the well-to-well tunneling
current intersects the contact load line. We have determined the
device-dependent critical current for the coherence resonance from experiments
and numerical simulations. We have also described through numerical simulations
how a coherence resonance triggers a stochastic resonance when its oscillation
mode becomes locked to a weak ac external voltage signal. Our results agree
with the experimental observations.",2011.09327v1
2020-11-29,Multichannel effects in the Efimov regime from broad to narrow Feshbach resonances,"We study Efimov physics of three identical bosons with pairwise multichannel
interactions for Feshbach resonances of adjustable width. We find that the
two-body multichannel nature of the interaction can affect the universal
three-body spectrum, especially for resonances of intermediate width. The
shifts in this universal spectrum are caused by trimer states in the closed
interaction channels that couple to the universal Efimov states. However, in
the narrow resonance limit we find that the Efimov spectrum is set by the
resonance width parameter $r^*$ only independent of the interaction potential
considered. In the broad resonance limit all excited Efimov trimer energies
approach the ones from the corresponding single-channel system for the
scenarios investigated.",2011.14332v1
2021-02-09,Polarisation control of quasi-monochromatic XUV produced via resonant high harmonic generation,"We present a numerical study of the resonant high harmonic generation by tin
ions in an elliptically-polarised laser field along with a simple analytical
model revealing the mechanism and main features of this process. We show that
the yield of the resonant harmonics behaves anomalously with the fundamental
field ellipticity, namely the drop of the resonant harmonic intensity with the
fundamental ellipticity is much slower than for high harmonics generated
through the nonresonant mechanism. Moreover, we study the polarisation
properties of high harmonics generated in elliptically-polarised field and show
that the ellipticity of harmonics near the resonance is significantly higher
than for ones far off the resonance. This introduces a prospective way to
create a source of the quasi-monochromatic coherent XUV with controllable
ellipticity potentially up to circular.",2102.05071v2
2021-02-13,The Surface response around a sharply resonant surface polariton mode is simply a Lorentzian,"At the planar interface between a material and vacuum, the complex surface
response S(omega)=[eps(omega) 1]/[eps(omega)+1], with eps(omega) the relative
complex dielectric permittivity of the material, exhibit resonances, typical of
the surface polariton modes, when eps(omega) ~ 1. We show that for a moderately
sharp resonance, S(omega) is satisfactorily described with a mere (complex)
Lorentzian, independently of the details affecting the various bulk resonances
describing ) eps(omega). Remarkably, this implies a quantitative correlation
between the resonant behaviors of Re[S(omega)] and Im[S(omega)], respectively
associated to dispersive and dissipative effects in the surface near-field. We
show that this ""strong resonance"" approximation easily applies, and discuss its
limits, based upon published data for sapphire, CaF2 and BaF2. Extension to
interfaces between two media or to a non planar interface is briefly
considered.",2102.06948v3
2021-02-26,Kinetic planar resonators from strongly disordered ultra-thin MoC superconducting films investigated by transmission line spectroscopy,"""The non-contact broadband transmission line flip-chip spectroscopy technique
is utilized to probe resonances of mm-sized square kinetic planar resonators
made from strongly disordered molybdenum carbide films, in the GHz frequency
range. The temperature dependence of the resonances was analyzed by the complex
conductivity of disordered superconductor, as proposed in Ref. arXiv:1407.2402
, which involves the Dynes superconducting density of states. The obtained
Dynes broadening parameters relate reasonably to the ones estimated from
scanning tunneling spectroscopy measurements. The eigenmodes of the kinetic
planar 2D resonator were visualized by EM model in Sonnet software. The proper
understanding of the nature of these resonances can help to eliminate them, or
utilize them e.g. as filters.""",2102.13483v1
2021-03-04,Pseudo-Jahn-Teller interaction among electronic resonant states of H3,"We study the electronic resonant states of H3 with energies above the
potential energy surface of the H3+ ground state. These resonant states are
important for the dissociative recombination of H3+ at higher collision
energies, and previous studies have indicated that these resonant states
exhibit a triple intersection. We introduce a complex generalization of the
pseudo-Jahn-Teller model to describe these resonant states. The potential
energies and the autoionization widths of the resonant states are computed with
electron scattering calculations using the complex Kohn variational method, and
the complex model parameters are extracted by a least-square fit to the
results. This treatment results in a non-Hermitian pseudo-Jahn-Teller
Hamiltonian describing the system. The non-adiabatic coupling and geometric
phase are further calculated and used to characterize the enriched topology of
the complex adiabatic potential energy surfaces.",2103.02935v1
2021-03-08,Fine structure of second-harmonic resonances in χ^{(2)} optical microresonators,"Owing to the discrete frequency spectrum of whispering gallery resonators
(WGRs), the resonance and phase-matching conditions for the interacting waves
in the case of second-harmonic generation (SHG) cannot generally be fulfilled
simultaneously. To account for this, we develop a model describing SHG in WGRs
with non-zero frequency detunings at both the pump and second-harmonic
frequencies. Our model predicts strong distortions of the line shape of pump
and second-harmonic resonances for similar linewidths at both frequencies; for
much larger linewidths at the second-harmonic frequency, this behavior is
absent. Furthermore, it describes the SHG efficiency as a function of detuning.
Experimentally, one can change the WGR eigenfrequencies, and thus the relative
detuning between pump and second-harmonic waves by a number of means, for
example electro-optically and thermally. Using a lithium niobate WGR, we show
an excellent quantitative agreement for the SHG efficiency between our
experimental results and the model. Also, we show the predicted distortions of
the pump and second-harmonic resonances to be absent in the lithium niobate
WGR, but present in a cadmium silicon phosphide WGR, as expected from the
linewidths of the resonances involved.",2103.04926v1
2021-03-15,Resonant Raman scattering of single molecules under strong cavity coupling and ultrastrong optomechanical coupling in plasmonic resonators: phonon-dressed polaritons,"Plasmonic dimer cavities can induce extreme electric-field hot spots that
allow one to access ultrastrong coupling regimes using Raman-type spectroscopy
on single vibrating molecules. Using a generalized master equation, we study
resonant Raman scattering in the strong coupling regime of cavity-QED, when
also in the vibrational ultrastrong coupling regime, leading to ""phonon-dressed
polaritons"". The master equation rigorously includes spectral baths for the
cavity and vibrational degrees of freedom, as well as a pure dephasing bath for
the resonant two-level system, which play a significant role. Employing
realistic parameters for gold dimer cavity modes, we investigate the emission
spectra in several characteristic strong-coupling regimes, leading to extremely
rich spectral resonances due to an interplay of phonon-modified polariton
states and bath-induced resonances. We also show explicitly the failure of the
standard master equation in these quantum nonlinear regimes.",2103.08670v3
2021-03-23,Bound states in the continuum and Fano resonances in subwavelength resonator arrays,"When wave scattering systems are subject to certain symmetries, resonant
states may decouple from the far-field continuum; they remain localized to the
structure and cannot be excited by incident waves from the far field. In this
work, we use layer-potential techniques to prove the existence of such states,
known as bound states in the continuum, in systems of subwavelength resonators.
When the symmetry is slightly broken, this resonant state can be excited from
the far field. Remarkably, this may create asymmetric (Fano-type) scattering
behaviour where the transmission is fundamentally different for frequencies on
either side of the resonant frequency. Using asymptotic analysis, we compute
the scattering matrix of the system explicitly, thereby characterizing this
Fano-type transmission anomaly.",2103.12470v1
2021-04-04,Light guiding and optical resonances in ZnS microstructures doped with Ga or In,"The high refractive index of ZnS (about 2.4 in the visible range) makes ZnS
microstructures good candidates for the fabrication of light guides and
resonant microcavities. Light guiding behaviour has been studied in several ZnS
structures. In particular, in this work the behavior of rods and plates has
been investigated and it is has been shown that the morphology of the studied
structures plays a determinant role on the supported resonant modes. In ZnS:Ga
and ZnS:In structures investigated in the present work Fabry-Perot as well as
Whispering Gallery resonant modes are supported. A good agreement has been
found between the experimental results and the theoretical model used to
describe both types of resonances, which have been used to estimate the
refractive index of the doped material. In ZnS:Ga wires with triangular
cross-section a lasing effect has been observed in the blue-green range. To our
knowledge, it is the first time that resonant modes in visible region have been
studied in doped ZnS.",2104.01645v1
2021-05-10,Searching for single-particle resonances with the Green's function method,"Single-particle resonances in the continuum are crucial for studies of exotic
nuclei. In this study, the Green's function approach is employed to search for
single-particle resonances based on the relativistic-mean-field model. Taking
$^{120}$Sn as an example, we identify single-particle resonances and determine
the energies and widths directly by probing the extrema of the Green's
functions. In contrast to the results found by exploring for the extremum of
the density of states proposed in our recent study [Chin. Phys. C, 44:084105
(2020)], which has proven to be very successful, the same resonances as well as
very close energies and widths are obtained. By comparing the Green's functions
plotted in different coordinate space sizes, we also found that the results
very slightly depend on the space size. These findings demonstrate that the
approach by exploring for the extremum of the Green's function is also very
reliable and effective for identifying resonant states, regardless of whether
they are wide or narrow.",2105.04071v1
2021-05-12,Fano interference in quantum resonances from angle-resolved elastic scattering,"Asymmetric spectral line shapes are a hallmark of interference of a
quasi-bound state with a continuum of states. Such line shapes are well known
for multichannel systems, for example, in photoionization or Feshbach
resonances in molecular scattering. On the other hand, in resonant single
channel scattering, the signature of such interference may disappear due to the
orthogonality of partial waves. Here, we show that probing the angular
dependence of the cross section allows us to unveil asymmetric Fano profiles
also in a single channel shape resonance. We observe a shift in the peak of the
resonance profile in the elastic collisions between metastable helium and
deuterium molecules with detection angle, in excellent agreement with
theoretical predictions from full quantum scattering calculations. Using a
model description for the partial wave interference, we can disentangle the
resonant and background contributions and extract the relative phase
responsible for the characteristic Fano-like profiles from our experimental
measurements.",2105.05959v2
2021-05-14,Strongly resonant RABBITT on lithium,"The process of reconstruction of attosecond beating by interference of
two-photon transitions (RABBITT) can become resonant with a discrete atomic
level either in the intermediate or the final continuous states. Experimental
observations of the former [Phys. Rev. Lett. 104, 103003 (2010)] or latter
[Nat. Commun. 7, 10566 (2016)] cases revealed modification of only those parts
of the photoelectron spectrum that overlapped directly with the resonance. In
the lithium atom and other members of the alkali metal family, the valence
shell $ns\to np$ transition to the intermediate RABBITT state affects the whole
photoelectron spectrum in the final state. The strong additional resonant
channel modifies entirely the ionization dynamics and opens direct access to
the resonant phase of the two-photon transitions which is common for various
single and multiple electron ionization processes. Elucidation of this phase
has wider implications for strongly resonant laser-matter interaction.",2105.06602v3
2021-05-17,Integrated molecular optomechanics with hybrid dielectric-metallic resonators,"Molecular optomechanics stems from the description of Raman scattering in the
presence of an optical resonator using a cavity optomechanics formalism. We
extend the molecular optomechanics formalism to the case of hybrid
dielectric-plasmonic resonators, with multiple optical resonances and with both
free-space and waveguide addressing. We demonstrate how the Raman enhancement
is the product of a pump enhancement and a modified LDOS, that simply depend on
the complex response functions of the hybrid system. The Fano lineshapes that
result from hybridization of a broadband and narrowband modes allows reaching
strong Raman enhancement with high-Q resonances, paving the way towards
sideband resolved molecular optomechanics. The model allows prediction of the
Raman emission ratio into different output ports and enables demonstrating a
fully integrated high-Q Raman resonator exploiting multiple cavity modes
coupled to the same waveguide.",2105.07887v2
2021-05-21,Continuous radio frequency electric-field detection through adjacent Rydberg resonance tuning,"We demonstrate the use of multiple atomic-level Rydberg-atom schemes for
continuous frequency detection of radio frequency (RF) fields. Resonant
detection of RF fields by electromagnetically-induced transparency and
Autler-Townes (AT) in Rydberg atoms is typically limited to frequencies within
the narrow bandwidth of a Rydberg transition. By applying a second field
resonant with an adjacent Rydberg transition, far-detuned fields can be
detected through a two-photon resonance AT splitting. This two-photon AT
splitting method is several orders of magnitude more sensitive than
off-resonant detection using the Stark shift. We present the results of various
experimental configurations and a theoretical analysis to illustrate the
effectiveness of this multiple level scheme. These results show that this
approach allows for the detection of frequencies in continuous band between
resonances with adjacent Rydberg states.",2105.10561v1
2021-05-18,Tunable High-Q Resonator by General Impedance Converter,"For the need of measurements focused in condensed matter physics and
especially Bernoulli effect in superconductors we have developed an active
resonator with dual operational amplifiers. A tunable high-Q resonator is
performed in the schematics of the the General Impedance Converter (GIC). In
the framework of frequency dependent open-loop gain of operational amplifiers,
a general formula of the frequency dependence of the impedance of GIC is
derived. The explicit formulas for the resonance frequency and Q-factor include
as immanent parameter the crossover frequency of the operational amplifier.
Voltage measurements of GIC with a lock-in amplifier perfectly agree with the
derived formulas. A table reveals that electrometer operational amplifiers are
the best choice to build the described resonator.",2105.11536v2
2021-06-01,Effect of symmetry defect on the edge resonance of semi-infinite FGM plates,"The effect of asymmetric functionally graded material on the edge resonance
and the Fano resonance in semi-infinite FGM plates are reported in this work.
The edge resonance is weakened by the material perturbation and the complete
mode conversion is illustrated with incident $S_0$ mode. The Fano resonance
occurs on the reflected $A_0$ mode as a result of interference between the
resonance and direct scattering with incident $A_0$ mode. A hybrid analytical
model based on the collocation discretization and the modal decomposition of
the elastic field is developed to analyze the scattering properties of the
semi-infinite plates. The Fano line-shape is discussed in detail. The results
show that the Fano line shape is sensitive to the volume fraction, which is
beneficial for the quantitative guided wave application.",2106.00642v1
2021-06-14,On Absence of Threshold Resonances for Schrodinger and Dirac Operators,"Using a unified approach employing a homogeneous Lippmann-Schwinger-type
equation satisfied by resonance functions and basic facts on Riesz potentials,
we discuss the absence of threshold resonances for Dirac and Schrodinger
operators with sufficiently short-range interactions in general space
dimensions.
  More specifically, assuming a sufficient power law decay of potentials, we
derive the absence of zero-energy resonances for massless Dirac operators in
space dimensions $n \geq 3$, the absence of resonances at $\pm m$ for massive
Dirac operators (with mass $m > 0$) in dimensions $n \geq 5$, and recall the
well-known case of absence of zero-energy resonances for Schr\""odinger
operators in dimension $n \geq 5$.",2106.07143v1
2021-06-17,Squeeze-film effect on atomically thin resonators in the high-pressure limit,"The resonance frequency of membranes depends on the gas pressure due to the
squeeze-film effect, induced by the compression of a thin gas film that is
trapped underneath the resonator by the high frequency motion. This effect is
particularly large in low-mass graphene membranes, which makes them promising
candidates for pressure sensing applications. Here, we study the squeeze-film
effect in single layer graphene resonators and find that their resonance
frequency is lower than expected from models assuming ideal compression. To
understand this deviation, we perform Boltzmann and continuum finite-element
simulations, and propose an improved model that includes the effects of gas
leakage and can account for the observed pressure dependence of the resonance
frequency. Thus, this work provides further understanding of the squeeze-film
effect and provides further directions into optimizing the design of
squeeze-film pressure sensors from 2D materials.",2106.09368v1
2021-06-23,Efficient Kerr soliton comb generation in micro-resonator with interferometric back-coupling,"Nonlinear Kerr micro-resonators have enabled fundamental breakthroughs in the
understanding of dissipative solitons, as well as in their application to
optical frequency comb generation. However, the conversion efficiency of the
pump power into a soliton frequency comb typically remains below a few percent.
We introduce a hybrid Mach-Zehnder ring resonator geometry, consisting of a
micro-ring resonator embedded in an additional cavity with twice the optical
path length of the ring. The resulting interferometric back coupling enables to
achieve an unprecedented control of the pump depletion: pump-to-frequency comb
conversion efficiencies of up to 98\% of the usable power is experimentally
demonstrated with a soliton crystal comb. We assess the robustness of the
proposed on-chip geometry by generating a large variety of dissipative Kerr
soliton combs, which require a lower amount of pump power to be accessed, when
compared with an isolated micro-ring resonator with identical parameters.
Micro-resonators with feedback enable accessing new regimes of coherent soliton
comb generation, and are well suited for comb applications in astronomy,
spectroscopy and telecommunications.",2106.12110v1
2021-06-29,What is the resonant state in open quantum systems?,"The article reviews the theory of open quantum system from a perspective of
the non-Hermiticity that emerges from the environment with an infinite number
of degrees of freedom. The non-Hermiticity produces resonant states with
complex eigenvalues, resulting in peak structures in scattering amplitudes and
transport coefficients. After introducing the definition of resonant states
with complex eigenvalues, we answer typical questions regarding the
non-Hermiticity of open quantum systems. What is the physical meaning of the
complex eigenmomenta and eigenenergies? How and why do the resonant states
break the time-reversal symmetry that the system observes? Can we make the
probabilistic interpretation of the resonant states with diverging wave
functions? What is the physical meaning of the divergence of the wave
functions? We also present an alternative way of finding resonant states,
namely the Feshbach formalism, in which we eliminate the infinite number of the
environmental degrees of freedom. In this formalism, we attribute the
non-Hermiticity to the introduction of the retarded and advanced Green's
functions.",2106.15068v1
2021-07-06,Quantum resonant tunnelling enhances hydrogen bond rotation of confined water,"Many studies have revealed that confined water chain flipping is closely
related to the spatial size and even quantum effects of the confinement
environment. Here, we show that these are not the only factors that affect the
flipping process of a confined water chain. First-principles calculations and
analyses confirm that quantum tunnelling effects from the water chain itself,
especially resonant tunnelling, enhance the hydrogen bond rotation process.
Importantly, resonant tunnelling can result in tunnelling rotation of hydrogen
bonds with a probability close to 1 with only 0.597 eV provided energy.
Compared to sequential tunnelling, resonant tunnelling dominants water chain
flipping at temperatures up to 20 K higher. Additionally, the ratio of the
resonant tunnelling probability to the thermal disturbance probability at 200 K
is at least ten times larger than that of sequential tunnelling, which further
illustrates the enhancement of hydrogen bond rotation brought about by resonant
tunnelling.",2107.02619v1
2021-07-08,Nonlinear coupling of phononic resonators induced by surface acoustic waves,"The rising need for hybrid physical platforms has triggered a renewed
interest for the development of agile radio-frequency phononic circuits with
complex functionalities. The combination of travelling waves with resonant
mechanical elements appears as an appealing means of harnessing elastic
vibration. In this work, we demonstrate that this combination can be further
enriched by the occurrence of elastic non-linearities induced travelling
surface acoustic waves (SAW) interacting with a pair of otherwise linear
micron-scale mechanical resonators. Reducing the resonator gap distance and
increasing the SAW amplitude results in a frequency softening of the resonator
pair response that lies outside the usual picture of geometrical Duffing
non-linearities. The dynamics of the SAW excitation scheme allows further
control of the resonator motion, notably leading to circular polarization
states. These results paves the way towards versatile high-frequency
phononic-MEMS/NEMS circuits fitting both classical and quantum technologies.",2107.03865v1
2021-07-21,Vibrational resonance amplification in a thermo-optic optomechanical nanocavity,"Vibrational resonance amplifies a weak low-frequency signal by use of an
additional non-resonant high-frequency modulation. The realization of weak
signal enhancement in integrated nonlinear optical nanocavities is of great
interest for nanophotonic applications where optical signals may be of low
power. Here, we report experimental observation of vibrational resonance in a
thermo-optically bistable photonic crystal optomechanical resonator with an
amplification up to +16 dB. The characterization of the bistability can
interestingly be done using a mechanical resonance of the membrane, which is
submitted to a strong thermo-elastic coupling with the cavity.",2107.10096v1
2021-08-04,Enhanced Directional Quantum Emission by Tunable Topological Doubly-Resonant Cavities,"How to utilize topological microcavities to control quantum emission is one
of the ongoing research topics in the optical community. In this work, we
investigate the emission of quantum emitters in doubly-resonant topological
Tamm microcavity, which can simultaneously achieve dual resonances at two
arbitrary wavelengths according to the needs of practical application. To
achieve the enhancement of quantum emission in such cavities, we have exploited
the tunable doubly-resonant modes, in which one of resonant modes corresponds
to the pump laser wavelength and the other one is located at the emission
wavelength of quantum emitters. Both theoretical and experimental results
demonstrate that the pump excitation and emission efficiencies of quantum
emitters are greatly enhanced. The main physical mechanism can be explained by
the doubly-resonant cavity temporal coupled-mode theory. Furthermore, we
observe the faster emission rate and the higher efficiency of unidirectional
quantum emission, which have promising applications in optical detection,
sensing, filtering, and light-emitting devices.",2108.01872v1
2021-09-14,"Aluminum Cayley trees as scalable, broadband, multi-resonant optical antennas","An optical antenna can convert a propagative optical radiation into a
localized excitation, and reciprocally. Although optical antennas can be
readily created using resonant nanoparticles (metallic or dielectric) as
elementary building blocks, the realization of antennas sustaining multiple
resonances over a broad range of frequencies remains a challenging task. Here,
we use aluminum self-similar, fractal-like structures as broadband optical
antennas. Using electron energy loss spectroscopy, we experimentally evidence
that a single aluminum Cayley tree, a simple self-similar structure, sustains
multiple plasmonic resonances. The spectral position of these resonances is
scalable over a broad spectral range spanning two decades, from ultraviolet to
mid-infrared. Such multi-resonant structures are highly desirable for
applications ranging from non-linear optics to light harvesting and
photodetection, as well as surface-enhanced infrared absorption spectroscopy.",2109.06845v3
2021-09-16,The scattering coefficients of superconducting microwave resonators: I. Transfer-matrix approach,"We describe a unified classical approach for analyzing the scattering
coefficients of superconducting microwave resonators with a variety of
geometries. To fill the gap between experiment and theory, we also consider the
influences of small circuit asymmetry and the finite length of the feedlines,
and describe a procedure to correct them in typical measurement results. We
show that, similar to the transmission coefficient of a hanger-type resonator,
the reflection coefficient of a necklace- or bridge-type resonator does also
contain a reference point which can be used to characterize the electrical
properties of a microwave resonator in a single step. Our results provide a
comprehensive understanding of superconducting microwave resonators from the
design concepts to the characterization details.",2109.07762v2
2021-09-16,The scattering coefficients of superconducting microwave resonators: II. System-bath approach,"We describe a unified quantum approach for analyzing the scattering
coefficients of superconducting microwave resonators with a variety of
geometries. We also generalize the method to a chain of resonators with time
delays, and reveal several transport properties similar to a photonic crystal.
It is shown that both the quantum and classical analyses provide consistent
results, and they together reveal different decay and decoherence mechanisms in
a general microwave resonator. These results form a solid basis for
understanding the scattering spectrums of networks of microwave resonators, and
pave the way for applying superconducting microwave resonators in complex
circuits.",2109.07766v2
2021-09-28,Asymmetric lineshapes of Efimov resonances in mass-imbalanced ultracold gases,"The resonant profile of the rate coefficient for three-body recombination
into a shallow dimer is investigated for mass-imbalanced systems. In the
low-energy limit, three atoms collide with zero-range interactions, in a regime
where the scattering lengths of the heavy-heavy and the heavy-light subsystems
are positive and negative, respectively. For this physical system, the
adiabatic hyperspherical representation is combined with a fully semi-classical
method and we show that the shallow dimer recombination spectra display an
asymmetric lineshape that originates from the coexistence of Efimov resonances
with St\""uckelberg interference minima. These asymmetric lineshapes are
quantified utilizing the Fano profile formula. In particular, a closed form
expression is derived that describes the width of the corresponding Efimov
resonances and the Fano lineshape asymmetry parameter $q$. The profile of
Efimov resonances exhibits a $q-$reversal effect as the inter- and
intra-species scattering lengths vary. In the case of a diverging asymmetry
parameter, i.e. $|q|\to \infty$, we show that the Efimov resonances possess
zero width and are fully decoupled from the three-body and atom-dimer continua,
and the corresponding Efimov metastable states behave as bound levels.",2109.13560v2
2021-10-05,Enhanced Sensitivity of Degenerate System Made of Two Unstable Resonators Coupled by Gyrator Operating at an Exceptional Point,"We demonstrate that a circuit comprising two unstable LC resonators coupled
via a gyrator supports an exceptional point of degeneracy (EPD) with purely
real eigenfrequency. Each of the two resonators includes either a capacitor or
an inductor with a negative value, showing purely imaginary resonance frequency
when not coupled to the other via the gyrator. With external perturbation
imposed on the system, we show analytically that the resonance frequency
response of the circuit follows the square-root dependence on perturbation,
leading to possible sensor applications. Furthermore, the effect of small
losses in the resonators is investigated, and we show that losses lead to
instability. In addition, the EPD occurrence and sensitivity are demonstrated
by showing that the relevant Puiseux fractional power series expansion
describes the eigenfrequency bifurcation near the EPD. The EPD has the great
potential to enhance the sensitivity of a sensing system by orders of
magnitude. Making use of the EPD in the gyrator-based circuit, our results pave
the way to realize a new generation of high-sensitive sensors to measure small
physical or chemical perturbations.",2110.01860v1
2021-10-13,The $Ω_{cc}$ resonances with negative parity in the chiral constituent quark model,"Spectrum of the low-lying $\Omega_{cc}$ resonances with negative parity,
which are assumed to be dominated by $sccq\bar{q}$ pentaquark components, is
investigated using the chiral constituent quark model. Energies of the
$\Omega_{cc}$ resonances are obtained by considering the hyperfine interaction
between quarks by exchanging Goldstone boson. Possible $sccq\bar{q}$
configurations with spin-parity $1/2^{-}$, $3/2^{-}$ and $5/2^{-}$ are taken
into account. Numerical results show that the lowest $\Omega_{cc}$ resonances
with negative parity may lie at $4050 \pm 100$ MeV. In addition, the
transitions of the $\Omega_{cc}$ resonance to a pseudoscalar meson and a ground
baryon state are also investigated within the chiral Lagrangian approach. We
expect that these $\Omega_{cc}$ resonances could be observed in the
$\bar{D}\Xi_{c}$ channel by future experiments.",2110.06408v2
2021-10-21,Five-body resonances in $^8$He and $^8$C using the complex scaling method,"We study many-body resonances in the neuron-rich $^8$He and the mirror
proton-rich $^8$C using the $^4$He+$N$+$N$+$N$+$N$ five-body model with the
isospin $T=2$ system. Resonances are described with the complex energy
eigenvalues as the Gamow states using the complex scaling method. In $^8$He, we
obtain five states, in which four states are resonances, and in $^8$C all five
states are resonances.We discuss the isospin-symmetry breaking dynamically
induced by the Coulomb interaction in the energy spectra and decay widths of
the resonances in two mirror nuclei. We predict the resonance energies and
decay widths for the future experiments. We also investigate the configurations
of valence nucleons above $^4$He in two nuclei with the $jj$ coupling scheme
and all the states dominantly have the $p$-shell configurations. From the
configuration mixing, $^8$He and $^8$C give the similar results, which
indicates the good symmetry in two nuclei.",2110.11041v1
2021-11-15,Feshbach resonances of large mass-imbalance Er-Li mixtures,"We report on the experimental observation of Feshbach resonances in large
mass-imbalance mixtures of Erbium (Er) and Lithium (Li). All combinations
between ${}^{168}$Er, ${}^{166}$Er and ${}^7$Li, ${}^6$Li are cooled to
temperatures of a few microkelvin, partially by means of sympathetic cooling
together with Ytterbium (Yb) as a third mixture component. The Er-Li inelastic
interspecies collisional properties are studied for magnetic fields up to 680
G. In all cases resonant interspecies loss features, indicative of Feshbach
resonances, have been observed. While most resonances have sub-Gauss widths, a
few of them are broad and feature widths of several Gauss. Those broad
resonances are a key to the realization of ultracold Er-Li quantum gas mixtures
with tunable interactions.",2111.08130v1
2021-12-02,The mass exclusion limits for the BSM vector resonances with the direct couplings to the third quark generation,"The upper bounds that the LHC measurements searching for heavy resonances
beyond the Standard model set on the resonance production cross sections are
not universal. They depend on various characteristics of the resonance under
consideration, and their validity is also limited by the assumptions and
approximations applied to their calculations. The bounds are typically used to
derive the mass exclusion limits for the new resonances. We address some of the
issues that emerge when deriving the mass exclusion limits for the strongly
coupled composite $SU(2)_{L+R}$ vector resonance triplet which would interact
directly to the third quark generation only. We show that the presence of such
interactions in the model can lower the mass exclusion limits.",2112.01430v1
2021-12-06,Fate of Multiparticle Resonances: From $Q$-Balls to $^3$He Droplets,"We consider a system of $N$ nonrelativistic particles which form a
near-threshold resonance. Assuming no subset of these particles can form a
bound state, the resonance can only decay through an ""explosion"" into $N$
particles. We show that the decay width of the resonance scales as
$E^{\Delta-5/2}$ in the limit when the energy $E$ of the resonance goes to
zero, where $\Delta$ is the ground state energy of a system of $N$ particles in
a spherical harmonic trap with unit frequency. The formula remains valid when
some pairs of final particles have zero-energy $s$-wave resonance, but the
Efimov effect is not present. In the limit of large $N$, we show that the final
particles follow a Maxwell-Boltzmann distribution if they are bosons, and a
semicircle-like law if they are fermions. We argue that metastable $^3$He
droplets exist with the lifetime varying over many orders of magnitudes ranging
from a fraction of a nanosecond to values greatly exceeding the age of the
Universe.",2112.03318v1
2021-12-13,Effect of interfacial damping on high-frequency surface wave resonance on a nanostrip-bonded substrate,"Since surface acoustic waves (SAW) are often generated on substrates to which
nanostrips are periodically attached, it is very important to consider the
effect of interface between the deposited strip and the substrate surface,
which is an unavoidable issue in manufacturing. In this paper, we propose a
theoretical model that takes into account the interface damping and calculate
the dispersion relationships both for frequency and attenuation of SAW
resonance. This results show that the interface damping has an insignificant
effect on resonance frequency, but, interestingly, attenuation of the SAW can
decrease significantly in the high frequency region as the interface damping
increases. Using picosecond ultrasound spectroscopy, we confirm the validity of
our theory; the experimental results show similar trends both for resonant
frequency and attenuation in the SAW resonance. Furthermore, the resonant
behavior of the SAW is simulated using the finite element method, and the
intrinsic cause of interface damping on the vibrating system is discussed.
These findings strongly indicate the necessity of considering interfacial
damping in the design of SAW devices.",2112.06367v1
2021-12-30,Amorphous Selenium Mie Resonators for Infrared Meta-Optics,"Applying direct growth and deposition of optical surfaces holds great promise
for the advancement of future nanophotonic technologies. Here, we report on a
chemical vapor deposition (CVD) technique for depositing amorphous selenium
(a-Se) spheres by desorption of selenium from Bi2Se3 and re-adsorption on the
substrate. We utilize this process to grow scalable, large area Se spheres on
several substrates and characterize their Mie-resonant response in the
mid-infrared (MIR) spectral range. We demonstrate size-tunable Mie resonances
spanning the 2-16 um spectral range, for single isolated resonators and large
area ensembles, respectively. We further demonstrate strong absorption dips of
up to 90% in ensembles of particles in a broad MIR range. Finally, we show that
ultra-high-Q resonances arise in the case where Se Mie-resonators are coupled
to low-loss epsilon-near-zero (ENZ) substrates. These findings demonstrate the
enabling potential of amorphous Selenium as a versatile and tunable
nanophotonic material that may open up avenues for on-chip MIR spectroscopy,
chemical sensing, spectral imaging and large area metasurface fabrication.",2112.14989v1
2022-01-15,Pairing effects on vorticity of incident neutron current at quasiparticle resonance energies in $n$-$A$ elastic scattering,"In this study, we analyzed how the incident neutron current is affected by
the pairing effect in the neutron-nucleus scattering described within the
framework of Hartree-Fock-Bogoliubov theory by performing numerical
calculations in terms of current, vorticity, and circulation of the incident
neutron current. We found that the pairing effect on the incident neutron flux
is completely different between particle-type and hole-type quasiparticle
resonances. In the case of h-type quasiparticle resonance, the pairing acts to
prevent the neutron flux from entering the nucleus, reducing circulation. In
the case of p-type quasiparticle resonance, pairing acts to reduce circulation
at energies lower than the resonance energy, but at energies higher than the
resonance energy, the effect of pairing on the neutron flux is reversed and,
conversely, circulation is increased.",2201.05824v1
2022-01-25,Strong decays of multi-strangeness baryon resonances in the quark model,"Decay properties of multi-strangeness $\Xi$ and $\Omega$ baryon resonances
are investigated within the constituent quark model by including relativistic
corrections. The strong decay widths of various $\Xi$ and $\Omega$ resonances
are computed and tested for internal quark configurations to pin down their
spin-parity ($J^P$) quantum numbers and internal structures. We found that the
Roper-like resonances in the multi-strangeness sector have large decay widths
bearing resemblances to their siblings in light and heavy baryon sectors. In
addition, we obtained the decay ratio for the $\Omega(2012)$ as
$\Gamma{(\Omega\to \Xi \bar{K} \pi)} / \Gamma{(\Omega\to \Xi \bar{K})}=4.5\%$,
which is consistent with the experimental data when $J^P=3/2^-$ is assigned.
This observation holds the possibility that the $\Omega(2012)$ could naturally
be explained as a three-quark state in the quark model. The decays of other
low-lying $\Xi$ and $\Omega$ resonances are systematically analyzed, which
would be useful to unveil the structure of these resonances in future
experiments.",2201.10427v1
2022-01-26,Distinct forms of resonant optimality within insect indirect flight motors,"Insect flight motors are extraordinary natural structures that operate
efficiently at high frequencies. Structural resonance is thought to play a role
in ensuring efficient motor operation, but the details of this role are
elusive. While the efficiency benefits associated with resonance may be
significant, a range of counterintuitive behaviours are observed. In
particular, the relationship between insect wingbeat frequencies and thoracic
natural frequencies are uncertain, with insects showing wingbeat frequency
modulation over both short and long timescales. Here, we offer new explanations
for this modulation. We show how, in linear and nonlinear models of an indirect
flight motor, resonance is not a unitary state at a single frequency; but a
complex cluster of distinct and mutually-exclusive states, each representing a
different form of resonant optimality. Additionally, by characterising the
relationship between resonance and the state of negative work absorption within
the motor, we demonstrate how near-perfect negative work absorption can be
maintained over significant wingbeat frequency ranges. Our analysis leads to a
new conceptual model of flight motor operation: one in which insects are
indifferent to their precise wingbeat frequency, and robust to changes in
thoracic and environmental properties - illustrating the extraordinary
robustness of these natural motors.",2201.11060v2
2022-01-27,Multi-photon Atom Interferometry via cavity-enhanced Bragg Diffraction,"We present a novel atom interferometer configuration that combines large
momentum transfer with the enhancement of an optical resonator for the purpose
of measuring gravitational strain in the horizontal directions. Using Bragg
diffraction and taking advantage of the optical gain provided by the resonator,
we achieve momentum transfer up to $8\hbar k$ with mW level optical power in a
cm-sized resonating waist. Importantly, our experiment uses an original
resonator design that allows for a large resonating beam waist and eliminates
the need to trap atoms in cavity modes. We demonstrate inertial sensitivity in
the horizontal direction by measuring the change in tilt of our resonator. This
result paves the way for future hybrid atom/optical gravitational wave
detectors. Furthermore, the versatility of our method extends to a wide range
of measurement geometries and atomic sources, opening up new avenues for the
realization of highly sensitive inertial atom sensors.",2201.11693v3
2022-02-06,Simultaneous cooling by measuring one ancillary system,"We present a simultaneous-cooling protocol for a double-resonator system via
projective measurements on an ancillary $V$-type qutrit. Through repeated
measurements on the ground state of the ancillary system, the two resonators
can be cooled down to their respective ground states from thermal states. With
respect to the measurement-based cooling, an optimized measurement-interval
$\tau_{\rm opt}$ is analytically obtained for the first time, which is
inversely proportional to the collective thermal Rabi frequency $\Omega_{\rm
th}$ as a function of the resonators' average population of the last round.
Under about only $20$ optimized measurements, the average population of the
target resonators can be reduced by $6$ orders in magnitude. Our simultaneous
or collective cooling protocol is scalable to the systems with more numbers of
resonators and robust to the fluctuation in the resonator frequency.",2202.02743v2
2022-02-09,Weak pion-production and the second resonance region,"In this work we report the calculation of the total cross section for
pion-production by the dispersion of neutrinos on nucleons. We use a consistent
formalism for the intermediate resonance states of spin $3/2$ , taking care on
the conditions imposed by the invariance on contact transformations and using
the Sachs parametrization for the form factors. In addition, we incorporate
states in the second resonance region up to 1.6 GeV and implement different
approaches for all the dressed resonance propagators. In addition to the
$\Delta$(1232), we include the N$^*$(1440),N$^*$(1535)and N$^*$(1520) resonance
contributions, and it is shown that this inclusion improve the description of
the total cross section regards a model where only the $\Delta$(1230) resonance
is considered. Also results for antineutrinos are properly described.",2202.04760v1
2022-02-13,Fast readout and reset of a superconducting qubit coupled to a resonator with an intrinsic Purcell filter,"Coupling a resonator to a superconducting qubit enables various operations on
the qubit, including dispersive readout and unconditional reset. The speed of
these operations is limited by the external decay rate of the resonator.
However, increasing the decay rate also increases the rate of qubit decay via
the resonator, limiting the qubit lifetime. Here, we demonstrate that the
resonator-mediated qubit decay can be suppressed by utilizing the
distributed-element, multi-mode nature of the resonator. We show that the
suppression exceeds two orders of magnitude over a bandwidth of 600 MHz. We use
this ""intrinsic Purcell filter"" to demonstrate a 40-ns readout with 99.1%
fidelity and a 100-ns reset with residual excitation of less than 1.7%.",2202.06202v2
2022-02-21,Two-dimensional Helmholtz resonator arrays. Part I. Matched asymptotic expansions for thick- and thin-walled resonators,"We present a novel multipole formulation for computing the band structures of
two-dimensional arrays of cylindrical Helmholtz resonators. This formulation is
derived by combining existing multipole methods for arrays of ideal cylinders
with the method of matched asymptotic expansions. We construct asymptotically
close representations for the dispersion equations of the first band surface,
correcting and extending an established lowest-order (isotropic) result in the
literature for thin-walled resonator arrays. The descriptions we obtain for the
first band are accurate over a relatively broad frequency and Bloch vector
range and not simply in the long-wavelength and low-frequency regime, as is the
case in many classical treatments. Crucially, we are able to capture features
of the first band, such as low-frequency anisotropy, over a broad range of
filling fractions, wall thicknesses, and aperture angles. In addition to
describing the first band we use our formulation to compute the first band gap
for both thick- and thin-walled resonators, and find that thicker resonator
walls correspond to both a narrowing of the first band gap and an increase in
the central band gap frequency.",2202.09941v1
2022-02-24,Resonant chiral effects in nonlinear dielectric metasurfaces,"We study the resonant enhancement of linear and nonlinear chiroptical effects
in asymmetric silicon metasurfaces supporting multipolar Mie resonances and
quasi-bound states in the continuum (quasi-BICs). We demonstrate theoretically
and observe in experiment the pronounced linear circular dichroism at the
quasi-BIC resonances. We further find that both local field enhancement and
third-harmonic signal are large for Mie resonances and some quasi-BIC modes. We
explain the selectivity of the nonlinear enhancement by employing the concept
of critical coupling being more favorable for the modes with moderately large
radiative quality factors ($Q$ factors). We demonstrate experimentally strong
nonlinear chiroptical response associated with high efficiency of the
third-harmonic generation and large nonlinear circular dichroism varying from
$+0.918\pm0.049$ to $-0.771\pm0.004$ for the samples with different
asymmetries. We believe our results suggest a general strategy for engineering
nonlinear chiroptical response in dielectric resonant metasurfaces.",2202.12041v2
2022-03-03,Design Automation of Photonic Resonator Weights,"Neuromorphic photonic processors based on resonator weight banks are an
emerging candidate technology for enabling modern artificial intelligence (AI)
in high speed, analog systems. These purpose-built analog devices implement
vector multiplications with the physics of resonator devices, offering
efficiency, latency, and throughput advantages over equivalent electronic
circuits. Along with these advantages, however, often comes the difficult
challenges of compensation for fabrication variations and environmental
disturbances. In this paper we review sources of variation and disturbances
from our experiments, as well as mathematically define quantities that model
them. Then, we introduce how the physics of resonators can be exploited to
weight and sum multiwavelength signals. Finally, we outline automated design
and control methodologies necessary to create practical, manufacturable, and
high accuracy/precision resonator weight banks that can withstand operating
conditions in the field. This represents a road map for unlocking the potential
of resonator weight banks in practical deployment scenarios.",2203.01792v1
2022-03-15,On-chip ultra-compact hexagonal boron nitride topological ring-resonator in visible region,"Ultra-compact topological ring-resonators with chirality are important
devices for quantum optics. However, there are limited demonstrations of chiral
resonators, especially in the visible region. We proposed a topological
photonic ring-resonator based on hexagonal boron nitride (hBN) valley photonic
crystal (VPC). The spin-valley locking effect in VPC allows achieving robust
unidirectional transmission of edge states in the visible region (600 nm-650
nm). As a result, a high quality factor (679.3) with a free spectral range of
15.2 nm in the visible region can be achieved in a hBN all-pass filter with a
compact size. In addition, we investigated the transmission properties of hBN
ring-resonators with different shapes and combinations, confirming the
flexibility of designing topological ring-resonators based on this principle.
This design can be readily integrated with quantum photonic chips for broad
applications.",2203.07602v1
2022-03-16,Instability from high-order resonant chains in wide-separation massive planet systems,"Diversity in the properties of exoplanetary systems arises, in part, from
dynamical evolution that occurs after planet formation. We use numerical
integrations to explore the relative role of secular and resonant dynamics in
the long-term evolution of model planetary systems, made up of three equal mass
giant planets on initially eccentric orbits. The range of separations studied
is dominated by secular processes, but intersects chains of high-order
mean-motion resonances. Over time-scales of $10^8$ orbits, the secular
evolution of the simulated systems is predominantly regular. High-order
resonant chains, however, can be a significant source of angular momentum
deficit (AMD), leading to instability. Using a time-series analysis based on a
Hilbert transform, we associate instability with broad islands of chaotic
evolution. Previous work has suggested that first-order resonances could modify
the AMD of nominally secular systems and facilitate secular chaos. We find that
higher-order resonances, when present in chains, can have similar impacts.",2203.08870v1
2022-03-21,Dynamics of Transmon Ionization,"Qubit measurement and control in circuit QED rely on microwave drives, with
higher drive amplitudes ideally leading to faster processes. However,
degradation in qubit coherence time and readout fidelity has been observed even
under moderate drive amplitudes corresponding to few photons populating the
measurement resonator. Here, we numerically explore the dynamics of a driven
transmon-resonator system under strong and nearly resonant measurement drives,
and find clear signatures of transmon ionization where the qubit escapes out of
its cosine potential. Using a semiclassical model, we interpret this ionization
as resulting from resonances occurring at specific resonator photon
populations. We find that the photon populations at which these spurious
transitions occur are strongly parameter dependent and that they can occur at
low resonator photon population, something which may explain the experimentally
observed degradation in measurement fidelity.",2203.11235v1
2022-04-04,Voltage-driven exchange resonance achieving 100\% mechanical efficiency,"Magnetic resonances driven by current-induced torques are crucial tools to
study magnetic materials but are very limited in frequency and mechanical
efficiency. We propose an alternative mechanism, voltage-induced torque, to
realize high efficiency in generating high-frequency magnetization dynamics.
When a ferromagnet-topological insulator-ferromagnet trilayer heterostructure
is operated as an adiabatic quantum motor, voltage-induced torque arises from
the adiabatic motion of gapped topological electrons on the two interfaces and
act oppositely on the two ferromagnetic layers, which can excite the exchange
mode where the two ferromagnetic layers precess with a $\pi$-phase difference.
The exchange mode resonance, bearing a much higher frequency than the
ferromagnetic resonance, is accompanied by topological charge pumping, leading
to a sharp peak in electrical admittance at the resonance point. Because the
output current is purely adiabatic while dissipative current vanishes
identically, the proposed voltage-driven exchange resonance entails a
remarkably high mechanical efficiency close to unity, which is impossible in
any current-driven systems.",2204.03534v2
2022-04-19,Resonant and non-resonant integrated third order parametric down-conversion,"Third order parametric down-conversion describes a class of nonlinear
processes in which a pump photon can be down-converted into triplets of
photons. It has been identified as a source of non-classical light, with
capabilities beyond those offered by better-established processes such as
spontaneous four-wave mixing. Here we discuss the implementation of TOPDC in
integrated photonic systems. We derive equations for the rates of TOPDC in a
non-resonant (waveguide) and resonant (microring) platform, such that the
scaling with experimental parameters can be plainly seen. We find that
generally non-resonant platforms should be pursued for spontaneous TOPDC
(SpTOPDC), whereas resonant platforms are more suitable for stimulated TOPDC
(StTOPDC). We present a sample calculation for TOPDC rates in sample systems
with conservative and accessible parameters. We find that StTOPDC should be
observable with the current fabrication technology, and that with some progress
in the design of TOPDC platforms, integrated SpTOPDC too could be demonstrated
in the near term.",2204.09159v2
2022-04-26,Is the orbital distribution of multiplanet systems influenced by pure three-planet resonances?,"We analyze the distribution of known multi-planet systems ($N \geq 3$) in the
plane of mean-motion ratios, and compare it with the resonance web generated by
two-planet mean-motion resonances (2P-MMR) and pure 3-planet commensurabilities
(pure 3P-MMR). We find intriguing evidence of a statistically significant
correlation between the observed distribution of compact low-mass systems and
the resonance structure, indicating a possible causal relation. While resonance
chains such as Kepler-60, Kepler-80 and TRAPPIST-1 are strong contributors,
most of the correlation appears to be caused by systems not identified as
resonance chains. Finally, we discuss their possible origin through planetary
migration during the last stages of the primordial disc and/or an eccentricity
damping process.",2204.12364v2
2022-05-05,Mass distributions of dijet resonances from excited quarks at proton-proton colliders,"We study the expected experimental mass distributions of dijet resonances
from excited quarks in proton-proton collisions at energies $\sqrt{s}=$ 13, 14,
27, 100, 300, and 500 TeV. We explore in detail the expected shapes at both the
generator and experimental levels, and identify within the distributions the
effects of the excited quark natural width, parton momentum distributions of
the proton, radiation, and experimental resolution. We present both
differential and cumulative probability distributions as a function of dijet
mass, and the signal acceptance of a window in dijet mass centered on each
resonance. We find that for a range of resonance masses, between 10\% and 50\%
of $\sqrt{s}$, the dijet mass distributions and window acceptance are
practically universal, approximately invariant under changes in resonance mass
and $\sqrt{s}$. This work supports our Snowmass 2021 study on the sensitivity
to dijet resonances at proton-proton colliders.",2205.02781v1
2022-05-30,Triadic resonant instability in confined and unconfined axisymmetric geometries,"We present an investigation of the resonance conditions of axisymmetric
internal wave sub-harmonics in confined and unconfined domains. In both cases,
sub-harmonics can be spontaneously generated from a primary wave field if they
satisfy at least a resonance condition on their frequencies, of the form
$\omega_0 = \pm \omega_1 \pm \omega_2$. We demonstrate that, in an unconfined
domain, the sub-harmonics follow three dimensional spatial resonance conditions
similar to the ones of Triadic Resonance Instability (TRI) for Cartesian plane
waves. In a confined domain, however, the spatial structure of the
sub-harmonics is fully determined by the boundary conditions and we observed
that these conditions prevail upon the resonance conditions. In both
configurations, these findings are supported by experimental data showing good
agreement with analytical and numerical derivations.",2205.15179v1
2022-06-07,Triaxiality induced monopole-quadrupole-hexadecupole coupling in the isoscalar giant resonances for $^{86}\textrm{Ge}$,"The isoscalar giant resonances for $^{86}\textrm{Ge}$ are studied by the
quasiparticle finite amplitude method based on the covariant density functional
theory. In addition to the well-known monopole-quadrupole coupling that splits
the isoscalar giant monopole resonance in axially deformed nuclei, a
monopole-quadrupole-hexadecupole coupling is identified in the triaxially
deformed nucleus $^{86}\textrm{Ge}$, leading to the emergence of a distinct
resonance peak at the low energy side of the isoscalar monopole strength
function. The transition density of the triaxiality induced resonance peak
shows a strong interplay among monopole, quadrupole, and hexadecupole
vibrations. The resonance peak responses to monopole, quadrupole, and
hexadecupole perturbations simultaneously, which could be regarded as a
fingerprint of the triaxiality in $^{86}\textrm{Ge}$.",2206.03030v1
2022-06-09,"On retrograde orbits, resonances and stability","We start by reviewing our previous work on retrograde orbital configurations
and on modeling and identifying retrograde resonances. Then, we present new
results regarding the enhanced stability of retrograde configurations with
respect to prograde configurations in the low mass ratio regime of the planar
circular restricted 3-body problem. Motivated by the recent discovery of small
bodies which are in retrograde resonance with the Solar System's giant planets
we then explore the case with mass ratio 0.001 and show new stability maps in a
grid of semi-major axis versus eccentricity for the 2/1 and 1/2 retrograde
resonances. Finally, we explain how the stability borders of the 2/1 and 1/2
retrograde resonances are related to the resonant orbits' geometry.",2206.04628v1
2022-06-16,High-Q Resonances Governed by the Quasi-Bound States in the Continuum in All-Dielectric Metasurfaces,"The realization of high-Q resonances in a silicon metasurface with various
broken-symmetry blocks is reported. Theoretical analysis reveals that the sharp
resonances in the metasurfaces originate from symmetry-protected bound states
in the continuum (BIC) and the magnetic dipole dominates these peculiar states.
A smaller size of the defect in the broken-symmetry block gives rise to the
resonance with a larger Q factor. Importantly, this relationship can be tuned
by changing the structural parameter, resulting from the modulation of the
topological configuration of BICs. Consequently, a Q factor of more than 3,000
can be easily achieved by optimizing dimensions of the nanostructure. At this
sharp resonance, the intensity of the third harmonic generation signal in the
patterned structure can be 368 times larger than that of the flat silicon film.
The proposed strategy and underlying theory can open up new avenues to realize
ultrasharp resonances, which may promote the development of the potential
meta-devices for nonlinearity, lasing action, and sensing.",2206.07935v1
2022-07-05,High harmonic generation from a subwavelength dielectric resonator,"Higher-order optical harmonics entered the realm of nanostructured solids
being observed recently in optical gratings and metasurfaces with a
subwavelength thickness. Structuring materials at the subwavelength scale
allows for resonant enhancing of the efficiency of nonlinear processes and
reducing the size of high-harmonic sources. Here we report the observation of
up to a seventh harmonic generated from a single subwavelength resonator made
of AlGaAs material. This process is enabled by careful engineering of the
resonator geometry for supporting optical modes associated with a quasi-bound
state in the continuum in the mid-infrared spectral range at around
{\lambda}=3.7 {\mu}m pump wavelength. The resonator volume measures ~ 0.1
{\lambda}^3. The resonant modes are excited with an azimuthally polarized
tightly focused beam. We evaluate the contributions of perturbative and
non-perturbative nonlinearities to the harmonic generation process. Our work
proves the possibility to miniaturize solid-state sources of high harmonics to
the subwavelength volumes.",2207.09407v4
2022-08-06,"Origin of the low energy resonance in the double photoionization of pyrene and coronene, and its absence in the double photoionization of corannulene","The low energy resonance in the double photoionization of the aromatic
hydrocarbons pyrene (C$_{16}$H$_{10}$) and coronene (C$_{24}$H$_{12}$) is
investigated theoretically using an approach based on the one-dimension Hubbard
model for $\pi$-conjugated systems with nearest-neighbor interactions. The
Independent Subsystem Approximation, where the perimeter and interior carbon
atoms are treated as independent entities, is employed. Since no low energy
resonances have been found in aromatic hydrocarbons where there are only
perimeter carbon atoms, we attribute the low energy resonances in pyrene and
coronene to the interior carbon atoms. However, corannulene (C$_{20}$H$_{10}$)
having five interior carbon atoms does not exhibit a low-energy resonance in
the experimental data. We attribute the absence of this resonance to the odd
number of interior carbon atoms.",2208.03596v1
2022-08-22,Diamagnetic composites for high-Q levitating resonators,"Levitation offers extreme isolation of mechanical systems from their
environment, while enabling unconstrained high-precision translation and
rotation of objects. Diamagnetic levitation is one of the most attractive
levitation schemes, because it allows stable levitation at room temperature
without the need for a continuous power supply. However, dissipation by eddy
currents in conventional diamagnetic materials significantly limits the
application potential of diamagnetically levitating systems. Here, we present a
route towards high $Q$ macroscopic levitating resonators by substantially
reducing eddy current damping using graphite particle based diamagnetic
composites. We demonstrate resonators that feature quality factors $Q$ above
450,000 and vibration lifetimes beyond one hour, while levitating above
permanent magnets in high vacuum at room temperature. The composite resonators
have a $Q$ that is more than 400 times higher than that of diamagnetic graphite
plates. By tuning the composite particle size and density, we investigate the
dissipation reduction mechanism and enhance the $Q$ of the levitating
resonators. Since their estimated acceleration noise is as low as some of the
best superconducting levitating accelerometers at cryogenic temperatures, the
high $Q$ and large mass of the presented composite resonators positions them as
one of the most promising technologies for next generation ultra-sensitive room
temperature accelerometers.",2208.10393v1
2022-08-27,The missing link between standing- and traveling-wave resonators,"Optical resonators are structures that utilize wave interference and feedback
to confine light in all three dimensions. Depending on the feedback mechanism,
resonators can support either standing- or traveling-wave modes. Over the
years, the distinction between these two different types of modes has become so
prevalent that nowadays it is one of the main characteristics for classifying
optical resonators. Here, we show that an intermediate link between these two
rather different groups exists. In particular, we introduce a new class of
photonic resonators that supports a hybrid optical mode, i.e. at one location
along the resonator the electromagnetic fields associated with the mode feature
a purely standing-wave pattern, while at a different location, the fields of
the same mode represent a pure traveling wave. The proposed concept is general
and can be implemented using chip-scale photonics as well as free-space optics.
Moreover, it can be extended to other wave phenomena such as microwaves and
acoustics.",2208.12905v1
2022-08-29,Resonant Kushi-comb-like multi-frequency radiation of oscillating two-color soliton molecules,"Nonlinear waveguides with two distinct domains of anomalous dispersion can
support the formation of molecule-like two-color pulse compounds. They consist
of two tightly bound subpulses with frequency loci separated by a vast
frequency gap. Perturbing such a two-color pulse compound triggers periodic
amplitude and width variations, reminiscent of molecular vibrations. With
increasing strength of perturbation, the dynamics of the pulse compound changes
from harmonic to nonlinear oscillations. The periodic amplitude variations
enable coupling of the pulse compound to dispersive waves, resulting in the
resonant emission of multi-frequency radiation. We demonstrate that the
location of the resonances can be precisely predicted by phase-matching
conditions. If the pulse compound consists of a pair of identical subpulses,
inherent symmetries lead to degeneracies in the resonance spectrum. Weak
perturbations lift existing degeneracies and cause a splitting of the resonance
lines into multiple lines. Strong perturbations result in more complex emission
spectra, characterized by well separated spectral bands caused by resonant
Cherenkov radiation and additional four-wave mixing processes.",2208.13829v1
2022-10-25,Microwave-optical double resonance in a erbium-doped whispering-gallery-mode resonator,"We showcase an erbium-doped whispering-gallery-mode resonator with optical
modes that display intrinsic quality factors better than $10^8$ (linewidths
less than 2 MHz), and coupling strengths to collective erbium transitions of up
to 2$\pi\times$1.2 GHz - enough to reach the ensemble strong coupling regime.
Our optical cavity sits inside a microwave resonator, allowing us to probe the
spin transition which is tuned by an external magnetic field. We show a
modified optically detected magnetic resonance measurement that measures
population transfer by a change in coupling strength rather than absorption
coefficient. This modification was enabled by the strong coupling to our modes,
and allows us to optically probe the spin transition detuned by more than the
inhomogeneous linewidth. We contrast this measurement with electron
paramagnetic resonance to experimentally show that our optical modes are
confined in a region of large microwave magnetic field and we explore how such
a geometry could be used for coherent microwave-optical transduction.",2210.13793v1
2022-10-27,Resonant modal approximation of time-domain elastic scattering from nano-bubbles in elastic materials,"This paper is devoted to establishing the resonant modal expansion of the
low-frequency part of the scattered field for acoustic bubbles embedded in
elastic materials in the time domain. Due to the nano-bubble with damping,
Minnaert resonance can be induced at certain discrete resonant frequencies,
which forms the fundamental basis of effectively constructing elastic
metamaterials via the composite material theory. There are two major
contributions in this work. First, we ansatz a special form of the density,
approximate the incident field with a finite number of modes, and then obtain
an expansion with a finite number of modes for the acoustic-elastic wave
scattering in the time-harmonic regime. Second, we show that the low-frequency
part of the scattered field in the time domain can be well approximated by
using the resonant modal expansion with sharp error estimates. Interestingly,
we find that the $0$-th mode is the main contribution to the resonant modal
expansion.",2210.15352v2
2022-10-31,Andreev Reflection and Klein Tunneling in High-Temperature Superconductor/Graphene Junctions,"Scattering processes in quantum materials emerge as resonances in electronic
transport, including confined modes, Andreev states, and Yu-Shiba-Rusinov
states. However, in most instances, these resonances are driven by a single
scattering mechanism. Here we show the appearance of resonances due to the
combination of two simultaneous scattering mechanisms, one from
superconductivity and the other from graphene p-n junctions. These resonances
stem from Andreev reflection and Klein tunneling that occur at two different
interfaces of a hole-doped region of graphene formed at the boundary with
superconducting graphene due to proximity effects from
Bi$_2$Sr$_2$Ca$_1$Cu$_2$O$_{8+\delta}$. The resonances persist with gating the
from p$^+$-p and p-n configurations. The suppression of the oscillation
amplitude above the bias energy comparable to the induced superconducting gap
indicates the contribution from Andreev reflection. Our experimental
measurements are supported by quantum transport calculations in such
interfaces, leading to analogous resonances. Our results put forward a hybrid
scattering mechanism in graphene/high-temperature superconductor
heterojunctions of potential impact for graphene-based Josephson junctions.",2210.17503v2
2022-11-11,Wavy optical grating: wideband reflector and Fabry-Perot BICs,"In this study, we theoretically and numerically investigate the resonant
modes and reflectance of an optical grating consisting of a wavy dielectric
slab by applying the spectral element method. The presence of the wavy shape
transforms the waveguide modes into leaky resonant modes. A few resonant modes
with specific longitudinal wave number have infinitely large Q factor, while
the other resonant modes have finite Q factor. For the leaky resonant mode with
zero longitudinal wave number, the Q factor is inversely proportional to the
amplitude of the wavy shape. An array of multiple low-Q wavy gratings has a
high reflectance in a large bandwidth. A double-layer wavy grating forms a
Fabry-Perot cavity, which hosts Fabry-Perot bound states in the continuum
(BICs) at the resonant frequency. The Q-factor of the Fabry-Perot cavity can be
tuned by adjusting the distance between the two wavy slabs. The wavy shape
could be generated by a vibrational wave in a flat dielectric slab so that the
BICs mode and wideband reflectance could be controlled on-demand.",2211.06201v1
2022-11-17,Excitonic beam steering in an active van der Waals metasurface,"Two-dimensional transition metal dichalcogenides (2D TMDCs) are promising
candidates for ultra-thin active nanophotonic elements due to the strong
tunable excitonic resonances that dominate their optical response. Here we
demonstrate dynamic beam steering by an active van der Waals metasurface that
leverages large complex refractive index tunability near excitonic resonances
in monolayer molybdenum diselenide (MoSe2). Through varying the radiative and
nonradiative rates of the excitons, we can dynamically control both the
reflection amplitude and phase profiles, resulting in an excitonic phased array
metasurface. Our experiments show reflected light steering to angles between
-30{\deg} to 30{\deg} at three different resonant wavelengths corresponding to
the A exciton, B exciton, and trion. This active van der Waals metasurface
relies solely on the excitonic resonances of the monolayer MoSe2 material
rather than geometric resonances of patterned nanostructures, suggesting the
potential to harness the tunability of excitonic resonances for wavefront
shaping in emerging photonic applications.",2211.09297v1
2022-12-12,Impedance responses and size-dependent resonances in topolectrical circuits via the method of images,"Resonances in an electric circuit occur when capacitive and inductive
components are present together. Such resonances appear in admittance
measurements depending on the circuit's parameters and the driving AC
frequency. In this study, we analyze the impedance characteristics of
nontrivial topolectrical circuits such as one- and two-dimensional
Su-Schrieffer-Heeger circuits and reveal that size-dependent anomalous
impedance resonances inevitably arise in finite $LC$ circuits. Through the
\textit{method of images}, we study how resonance modes in a multi-dimensional
circuit array can be nontrivially modified by the reflection and interference
of current from the structure and boundaries of the lattice. We derive analytic
expressions for the impedance across two corner nodes of various lattice
networks with homogeneous and heterogeneous circuit elements. We also derive
the irregular dependency of the impedance resonance on the lattice size, and
provide integral and dimensionally-reduced expressions for the impedance in
three dimensions and above.",2212.06165v3
2022-12-12,Glueballs in Radiative $J/ψ$ Decays,"The scalar glueball is observed in a coupled-channel analysis of the $S$-wave
amplitude from BESIII data on radiative $J/\psi$ decays and further data. Ten
scalar isoscalar resonances were required to fit the data. Five of them were
interpreted as mainly-singlet, five as mainly-octet resonances in SU(3). The
yield of resonances showed a striking peak with properties expected from a
scalar glueball. The $D$ wave amplitude in the BESIII data on radiative
$J/\psi$ decays reveales a high-mass structure which can be described by a
single Breit-Wigner or by the sum of three $\phi\phi$ resonances interpreted as
tensor glueballs a long time ago. The structure - and further tensor resonances
observed in radiative $J/\psi$ decays - are tentatively interpreted as tensor
glueball. In $J/\psi$ decays into $\gamma\pi^0\pi^0\eta'$ several resonances
are reported. The possibility is discussed that the pseudoscalar glueball might
be hidden in these data.",2212.06214v1
2022-12-22,High-Q guided-mode resonance of a crossed grating with near-flat dispersion,"Guided-mode resonances in diffraction gratings are manifested as peaks (dips)
in reflection (transmission) spectra. Smaller resonance line widths (higher
Q-factors) ensure stronger light-matter interactions and are beneficial for
field-dependent physical processes. However, strong angular and spectral
dispersion are inherent to such high-Q resonances. We demonstrate that a class
of high-Q resonant modes (Q-factor >1000) exhibiting extraordinarily weak
dispersion can be excited in crossed gratings simultaneously with the modes
with well-known nearly linear dispersion. Furthermore, we show that the
polarization of the incoming light can be adjusted to engineer the dispersion
of these modes, and strong to near-flat dispersion or vice-versa can be
achieved by switching between two mutually orthogonal linear polarization
states. We introduce a semi-analytical model to explain the underlying physics
behind these observations and perform full-wave numerical simulations and
experiments to support our theoretical conjecture. The results presented here
will benefit all applications that rely on resonances in free-space-coupled
geometries.",2212.12059v1
2023-01-16,Coherent Control of ultracold molecular collisions: The role of resonances,"We consider the coherent control of ultracold molecule-molecule scattering,
impacted by a dense set of rovibrational resonances. To characterize the
resonance spectrum, a rudimentary model based on multichannel quantum defect
theory has been used to study the control of the scattering cross section and
the reaction rate. Complete control around resonance energies is shown to be
possible, but thermal averaging over a large number of resonances significantly
reduces the extent of control of reaction rates due to the random distribution
of optimal control parameters between resonances. We show that measuring the
extent of coherent control could be used to extract meaningful information
about the relative contribution of direct scattering versus collision complex
formation, as well as about the statistical regime.",2301.06541v1
2023-01-18,Plasma broadening of autoionizing resonances,"A general formulation is developed to demonstrate that atomic autoionizing
(AI) resonances are broadened and shifted significantly due to plasma effects
across bound-free continua. The theoretical and computational method presented
accounts for broadening mechanisms: electron collisional, ion microfields
(Stark), thermal Doppler, core excitations, and free-free transitions. {\it
Extrinsic} plasma broadening redistributes and shifts AI resonance strengths
while broadly preserving naturally {\it intrinsic} asymmetries of resonance
profiles. Integrated oscillator strengths are conserved as resonance structures
dissolve into continua with increasing electron density. As exemplar, the
plasma attenuation of photoionization cross sections computed using the
R-matrix method is studied in neon-like Fe~XVII in a critical range $N_e =
10^{21-24}$cc along isotherms $T = 1-2 \times 10^6$K, and its impact on
Rosseland Mean opacities. The energy-temperature-density dependent cross
sections would elicit and introduce physical features in resonant processes in
photoionization, \eion excitation and recombination. The method should be
generally applicable to atomic species in high-energy-density (HED) sources
such as fusion plasmas and stellar interiors.",2301.07734v1
2023-01-20,Renormalization view on resonance proliferation between many-body localized phases,"Topology and many-body localization (MBL) have opened new avenues for
preserving quantum information at finite energy density. Resonant
delocalization plays a crucial role in destabilizing these phenomena. In this
work, we study the statistical properties of many-body resonances in a
disordered interacting Ising model - which can host symmetry protected
topological order - using a Clifford circuit encoding of the real space
renormalization group which allows the resonant properties of the wave
functions to be efficiently characterized. Our findings show that both the
trivial and topologically ordered MBL phases remain stable to the resonances,
but in the vicinity of the transition between them localization is destabilized
by resonance proliferation. Diverging susceptibility towards the development of
an avalanche instability suggests an intervening ergodic phase. We are also
able to access the local integrals of motion in the MBL phases and identify the
topological edge-mode operators in the ordered phase. Our results have
important implications for the stability of MBL and phase transitions between
distinct MBL phases with and without symmetries.",2301.08738v3
2023-01-29,Experimental investigation of the thermal emission cross-section of nano-resonators using hierarchical Poisson-disk distributions,"Effective cross-sections of nano-objects are fundamental properties that
determine their ability to interact with light. However, measuring them for
individual resonators directly and quantitatively remains challenging,
particularly because of the very low signals involved. Here, we experimentally
measure the thermal emission cross-section of metal-insulator-metal
nano-resonators using a stealthy hyperuniform distribution based on a
hierarchical Poisson-disk algorithm. In such distributions, there are no
long-range interactions between antennas, and we show that the light emitted by
the metasurface behaves as the sum of cross-sections of independent
nanoantennas, enabling direct retrieval of the single resonator contribution.
The emission cross-section at resonance is found to be of the order of
$\mathbf{\lambda_0^2/3}$, a value that is nearly three times larger than the
theroretical maximal absorption cross-section of a single particle but remains
smaller than the maximal extinction cross-section. This measurement technique
can be generalized to any single resonator cross-section, and we also apply it
here to the extinction cross-section.",2301.12469v1
2023-02-07,Spatial mapping and analysis of graphene nanomechanical resonator networks,"Nanoelectromechanical (NEMS) resonator networks have drawn increasing
interest due to their potential applications in emergent behavior, sensing,
phononics, and mechanical information processing. A challenge toward realizing
these large-scale networks is the ability to controllably tune and reconfigure
the collective, macroscopic properties of the network, which relies directly on
the development of methods to characterize the constituent NEMS resonator
building blocks and their coupling. In this work, we demonstrate a scalable
optical technique to spatially map graphene NEMS networks and read out the
fixed-frequency collective response as a single vector. Using the response
vectors, we introduce an efficient algebraic approach to quantify the
site-specific elasticity, mass, damping, and coupling parameters of network
clusters. We apply this technique to accurately characterize single uncoupled
resonators and coupled resonator pairs by sampling them at just two
frequencies, and without the use of curve fitting or the associated a priori
parameter estimates. Our technique may be applied to a range of classical and
quantum resonator systems and fills in a vital gap for programming NEMS
networks.",2302.03680v1
2023-02-09,Characterising Polariton States in Non-Dispersive Regime of Circuit Quantum Electrodynamics,"A superconducting qubit coupled to a read-out resonator is currently the
building block of multiple quantum computing as well as quantum optics
experiments. A typical qubit-resonator system is coupled in the dispersive
regime, where the detuning between qubit and resonator is much greater than the
coupling between them. In this work, we fabricated and measured a
superconducting transmon-resonator system in the non-dispersive regime. The
dressed states formed by the mixing of the bare qubit and resonator states can
be further mixed by applying a drive on the qubit, leading to the formation of
polariton states. We report experimental studies of transitions between
polariton states at varying driving powers and frequencies and show how the
non-dispersive coupling of the higher levels of the qubit-resonator system
modifies the polariton eigenstates and the corresponding transition
frequencies. We also report close agreement with numerical results obtained
from a driven Jaynes-Cummings Model beyond the dispersive regime.",2302.04523v2
2023-02-13,A Systematic Study on the Resonance in Collisional Neutrino Flavor Instability,"Investigations on the resonance in the collisional flavor instability (CFI)
of neutrinos, which were reported recently, are reported. We show that the
resonance occurs not only for the isotropy-preserving modes as pointed out in
the previous work but also for the isotropy-breaking modes and that it enhances
the growth rate of CFI by orders of magnitude. Employing the linear analysis
and nonlinear numerical simulations in the two-flavor scheme and under the
relaxation approximation for the collision term, we discuss the criterion for
the resonance, its effect on the nonlinear evolution as well as the influences
of homogeneity-breaking (k \ne 0) perturbations as well as of anisotropy in the
background on the resonance. We will also touch the cohabitation of the
resonance with the fast flavor conversion (FFC).",2302.06263v2
2023-02-28,Deeply-virtual Compton process $e^- N \to e^- γπN$ to study nucleon to resonance transitions,"We study the deeply-virtual Compton scattering (DVCS) process $e^- N \to e^-
\gamma \pi N$ involving the transition between a nucleon and a nucleon
resonance in the $\pi N$ system, within the framework of generalized parton
distributions (GPDs). For the four lowest-lying nucleon resonances,
$\Delta(1232)$, $P_{11}(1440)$, $D_{13}(1520)$, and $S_{11}(1535)$, we express
the DVCS amplitude in the Bjorken limit in terms of corresponding
nucleon-to-resonance GPDs. Building upon the knowledge of the well studied
electromagnetic nucleon-to-resonance transition form factors, which map the
quark charge densities in transverse position space, the corresponding GPDs
will open the prospect to also access the longitudinal momentum distributions
of quarks in the transition. We provide estimates for cross sections and
beam-spin asymmetries in the first and second $\pi N$ resonance regions in the
kinematics of forthcoming CLAS12 data from Jefferson Lab.",2303.00119v1
2023-03-05,Dissipative Capture of Planets Into First-Order Mean-Motion Resonances,"The emergence of orbital resonances among planets is a natural consequence of
the early dynamical evolution of planetary systems. While it is
well-established that convergent migration is necessary for mean-motion
commensurabilities to emerge, recent numerical experiments have shown that the
existing adiabatic theory of resonant capture provides an incomplete
description of the relevant physics, leading to an erroneous mass scaling in
the regime of strong dissipation. In this work, we develop a new model for
resonance capture that self-consistently accounts for migration and
circularization of planetary orbits, and derive an analytic criterion based
upon stability analysis that describes the conditions necessary for the
formation of mean-motion resonances. We subsequently test our results against
numerical simulations and find satisfactory agreement. Our results elucidate
the critical role played by adiabaticity and resonant stability in shaping the
orbital architectures of planetary systems during the nebular epoch, and
provide a valuable tool for understanding their primordial dynamical evolution.",2303.02766v1
2023-03-12,Towards practical mass spectrometry with nanomechanical pillar resonators by surface acoustic wave transduction,"Nanoelectromechanical systems (NEMS) have proven outstanding performance in
the detection of small masses down to single proton sensitivity. To obtain a
high enough throughput for the application in practical mass spectrometry, NEMS
resonators have to be arranged in two-dimensional (2D) arrays. However, all
state-of-the-art electromechanical transduction methods rely on electrical
lines placed close to the mechanical resonators, which drastically restricts
the density of 2D resonator arrays. An exception is the transduction by surface
acoustic waves (SAWs), which has so far only been shown for the transduction of
single nanomechanical pillar resonators. Here, we demonstrate the transduction
of pillar pairs by surface acoustic waves. The pillars have a diameter of 700
nm and show a mass responsivity of -588$\pm$98 ng$^{-1}$. The distances between
the pillar pairs are 70 nm and 14.3 $\mu$m. SAW transduction enabled us to
measure both pillars of each pair with electrical lines no closer than 300
$\mu$m, illustrating the potential of SAWs to transduce dense arrays of pillar
resonators, a crucial step towards practical mass spectrometry with NEMS.",2303.06665v1
2023-03-14,"ECMI Resonance in AKR Revisited: Hyperbolic Resonance, Harmonics, Wave-Wave Interaction","Recapitulation of the resonance condition for the fundamental and higher
electron cyclotron harmonics in the Electron Cyclotron Maser Instability (ECMI)
enables radiation below and confirms the possibility of radiation in a narrow
band above harmonics $n>1$. Near $n=1$ resonance on the confined lower X-mode
branch, amplification is supported by the decrease of phase and group speeds.
Confined slow large-amplitude quasi-electrostatic X-modes nonlinearly modulate
the plasma to form cavitons until self-trapped inside them at further
increasing wavenumber. They undergo wave-wave interaction, enabling escape to
free space in the second harmonic band below $n=2$. At sufficiently large
parallel wavenumber (oblique propagation), the fundamental resonance $n=1$ is
hyperbolic, a possibility so far missed but vital for an effective ECMI in the
upward current region. Here, the resonance hyperbola favourably fits the loss
cone boundary, the presumably important ECMI upward-current source-electron
distribution, to stimulate ECMI growth at available auroral electron energies.",2303.07950v1
2023-03-15,Fighting Broken Symmetry with Doping: Toward Polar Resonant Tunneling Diodes with Symmetric Characteristics,"The recent demonstration of resonant tunneling transport in nitride
semiconductors has led to an invigorated effort to harness this quantum
transport regime for practical applications. In polar semiconductors, however,
the interplay between fixed polarization charges and mobile free carriers leads
to asymmetric transport characteristics. Here, we investigate the possibility
of using degenerately doped contact layers to screen the built-in polarization
fields and recover symmetric resonant injection. Thanks to a high doping
density, negative differential conductance is observed under both bias
polarities of GaN/AlN resonant tunneling diodes (RTDs). Moreover, our
analytical model reveals a lower bound for the minimum resonant-tunneling
voltage achieved via uniform doping, owing to the dopant solubility limit.
Charge storage dynamics is also studied by impedance measurements, showing that
at close-to-equilibrium conditions, polar RTDs behave effectively as
parallel-plate capacitors. These mechanisms are completely reproduced by our
analytical model, providing a theoretical framework useful in the design and
analysis of polar resonant-tunneling devices.",2303.08383v1
2023-03-25,Soft dipole resonance in $^8$C and its isospin symmetry with $^8$He,"We investigate the soft dipole resonance in the proton-rich nucleus
$^8_6$C$_2$, which is a collective dipole oscillation of four valence protons
against the $\alpha$ core,and discuss the isospin symmetry with the mirror
nucleus $^8_2$He$_6$. We use the $\alpha+N+N+N+N$ five-body cluster model and
many-body resonances are obtained using the complex-scaling method. The $1^-$
resonance of $^8_6$C$_2$ is confirmed at the excitation energy of 13 MeV with a
large decay width of 24 MeV, and its structure is similar to the soft dipole
resonance in $^8_2$He$_6$, such as the configuration mixing and the spatial
properties. These results indicate a good isospin symmetry in the soft dipole
resonances of two nuclei with a common collective excitation of multiproton and
multineutron, while the ground states of two nuclei show different properties
due to the Coulomb repulsion of valence protons in $^8_6$C$_2$, leading to the
symmetry breaking. In conclusion, the appearance of the isospin symmetry
differs depending on the states of $^8_6$C$_2$ and $^8_2$He$_6$.",2303.14318v1
2023-04-04,Experimental Evidence of Amplitude-Dependent Surface Wave Dispersion via Nonlinear Contact Resonances,"In this letter, we provide an experimental demonstration of
amplitude-dependent dispersion tuning of surface acoustic waves interacting
with nonlinear resonators. Leveraging the similarity between the dispersion
properties of plate edge waves and surface waves propagating in a semi-infinite
medium, we use a setup consisting of a plate with a periodic arrangement of
bead-magnet resonators along one of its edges. Nonlinear contact between the
ferromagnetic beads and magnets is exploited to realize nonlinear local
resonance effects. First, we experimentally demonstrate the nonlinear softening
nature and amplitude-dependent dynamics of a single bead-magnet resonator on
both rigid and compliant substrates. Next, the dispersion properties of the
system in the linear regime are investigated. Finally, we demonstrate how the
interplay of nonlinear local resonances with plate edge waves gives rise to
amplitude-dependent dispersion properties. The findings will inform the design
of more versatile surface acoustic wave devices that can passively adapt to
loading conditions.",2304.01494v2
2023-04-16,Double-strangeness exchange reactions in a hybrid Regge-plus-resonance approach,"We investigate double-strangeness exchange reactions, $K^-p\to K^+\Xi^-$ and
$K^-p\to K^0\Xi^0$, using an effective Lagrangian approach based on a hybrid
Regge-plus-resonance model involving rescattering diagrams. We consider the
background processes that include $\Lambda$, $\Sigma$, and $\Sigma(1385)$ Regge
trajectories in the $u$ channel and the $s$-channel Born-term diagrams. The
$s$-channel hyperon resonances account for the bump structures in the total
cross sections. The $s$-channel $\Lambda(2100,7/2^-)$ and $\Sigma(2030,7/2^+)$
resonances contribute significantly, and the $\Sigma(2250)$ resonance favors
$J^P = 7/2^-$. The interference pattern between the $\Lambda(2100,7/2^-)$ and
$\Sigma(2030,7/2^+)$ amplitudes is essential for describing forward
differential cross sections in the resonance region $2.07 < \sqrt{s} < 2.15$
GeV. The absence of the $S=-2$ meson leads to the inclusion of the meson-baryon
rescattering diagrams to describe the $K^- p \to K\Xi$ reaction data, proving
the significant contribution of the $(\phi,\rho,\omega)$--$(\Lambda,\Sigma)$
rescattering diagrams.",2304.07725v1
2023-04-17,Identification and Mitigation of Conducting Package Losses for Quantum Superconducting Devices,"Low-loss superconducting rf devices are required when used for quantum
computation. Here, we present a series of measurements and simulations showing
that conducting losses in the packaging of our superconducting resonator
devices affect the maximum achievable internal quality factors (Qi) for a
series of thin-film Al quarter-wave resonators with fundamental resonant
frequencies varying between 4.9 and 5.8 GHz. By utilizing resonators with
different widths and gaps, different volumes of the stored electromagnetic
energy were sampled thus affecting Qi. When the backside of the sapphire
substrate of the resonator device is adhered to a Cu package with a conducting
silver glue, a monotonic decrease in the maximum achievable Qi is found as the
electromagnetic sampling volume is increased. This is a result of induced
currents in large surface resistance regions and dissipation underneath the
substrate. By placing a hole underneath the substrate and using superconducting
material for the package, we decrease the ohmic losses and increase the maximum
Qi for the larger size resonators.",2304.08629v2
2023-04-19,Characteristic modes of thick brane model: resonances and quasinormal modes,"In this work, we investigate the gravitational quasinormal modes (QNMs) and
the gravitational resonances of a thick brane model. We use the asymptotic
iteration and shooting methods to obtain the quasinormal frequencies (QNFs) of
the brane. On the other hand, we investigate the resonances and their evolution
numerically. The results show that the oscillations of the resonances equal (up
to numerical error) to the real parts of the QNFs, while the damping rates of
the resonances equal to the imaginary parts of the QNFs. The QNMs and
resonances, both of them can be regarded as the characteristic modes of the
thick brane, are closely related with each other. In addition, the lifetime of
these QNMs could be very long, perhaps they might be detected in future
accelerator or gravitational wave detector.",2304.09363v2
2023-04-26,Reliable and Repeatable Transit Through Cislunar Space Using the 2:1 Resonant Spatial Orbit Family,"This work focuses on the identification of reliable and repeatable spatial
(three-dimensional) trajectories that link the Earth and the Moon. For this
purpose, this paper aims to extend the 2:1 resonant prograde family and 2:1
resonant retrograde family to three dimensions and to introduce spatial orbits
that are not currently present in the literature. These orbits, named the 2:1
resonant spatial family, bifurcate from the two-dimensional families and
smoothly transition between them in phase space. The stability properties of
this new family of resonant orbits are discussed, and, interestingly, this
family includes marginally stable members. Furthermore, this new family of
orbits is applied to several engineering problems in the Earth-Moon system.
First, this paper selects an appropriate member of the 2:1 resonant spatial
family on the basis of its stability properties and relationships with other
multibody orbits in the regime. Next, this work combines this trajectory with
momentum exchange tethers to transit payloads throughout the system in a
reliable and repeatable fashion. Finally, this paper studies the process of
aborting a momentum exchange tether catch and related recovery opportunities.",2304.13584v2
2023-05-02,Combined effect of mutually frequency-detuned strong and weak drives on a two-level system: Envelope of the Rabi oscillations,"Near-resonant ac-drive acting on a two-level system induces the Rabi
oscillations of the level occupations. It is shown that additional weak drive
properly frequency-detuned from the primary drive causes a resonant response.
This response manifests itself in the emergence of the envelope of the
oscillations. At resonance, the inverse period of the envelope is proportional
to the amplitude of the weak drive. The resonant condition reads: difference of
frequencies between the two drives is equal to the ac-splitting of quasilevels
in the field of the strong drive. Technically, the resonance can be inferred
from the analogy between the equations for the time-evolution of the spin
amplitude and the Mathieu equation, which describes e.g. the parametric
resonance.",2305.01136v1
2023-05-05,Collateral coupling between superconducting resonators: Fast and high fidelity generation of qudit-qudit entanglement,"Superconducting circuits are highly controllable platforms to manipulate
quantum states, which make them particularly promising for quantum information
processing. We here show how the existence of a distance-independent
interaction between microwave resonators coupled capacitively through a qubit
offers a new control parameter toward this goal. This interaction is able to
induce an idling point between resonant resonators, and its state-dependent
nature allows one to control the flow of information between the resonators.
The advantage of this scheme over previous one is demonstrated through the
generation of high-fidelity NOON states between the resonators, with a lower
number of operations than previous schemes. Beyond superconducting circuits,
our proposal could also apply to atomic lattices with clock transitions in
optical cavities, for example.",2305.03564v1
2023-05-06,Excitonic Resonances in Coherent Anti-Stokes Raman Scattering from Single Wall Carbon Nanotubes,"In this work we investigate the role of exciton resonances in coherent
anti-Stokes Raman scattering (er-CARS) in single walled carbon nanotubes
(SWCNTs). We drive the nanotube system in simultaneous phonon and excitonic
resonances, where we observe a superior enhancement by orders of magnitude
exceeding non-resonant cases. We investigated the resonant effects in five
$(n,m)$ chiralities and find that the er-CARS intensity varies drastically
between different nanotube species. The experimental results are compared with
a perturbation theory model. Finally, we show that such giant resonant
non-linear signals enable rapid mapping and local heating of individualized
CNTs, suggesting easy tracking of CNTs for future nanotoxology studies and
therapeutic application in biological tissues.",2305.04029v2
2023-05-10,Detecting resonance of radio-frequency cavities using fast direct integral equation solvers and augmented Bayesian optimization,"This paper presents a computationally efficient framework for identifying
resonance modes of 3D radio-frequency (RF) cavities with damping waveguide
ports. The proposed framework relies on surface integral equation (IE)
formulations to convert the task of resonance detection to the task of finding
resonance frequencies at which the lowest few eigenvalues of the system matrix
is close to zero. For the linear eigenvalue problem \rev{with a fixed
frequency}, we propose leveraging fast direct solvers to efficiently invert the
system matrix; for the frequency search problem, we develop a hybrid
optimization algorithm that combines Bayesian optimization with down-hill
simplex optimization. The proposed IE-based resonance detection framework
(IERD) has been applied to detection of high-order resonance modes (HOMs) of
realistic accelerator RF cavities to demonstrate its efficiency and accuracy.",2305.05918v2
2023-05-28,Probing Ring Resonator Sensor Based on Vernier Effect,"The Vernier effect has seen extensive application in optical structures,
serving to augment the free spectral range (FSR). A substantial FSR is vital in
a myriad of applications including multiplexers, enabling a broad, clear band
comparable to the C-band to accommodate a maximum number of channels.
Nevertheless, a large FSR often conflicts with bending loss, as it necessitates
a smaller resonator radius, thus increase the insertion loss in the bending
portion. To facilitate FSR expansion without amplifying bending loss, we
employed cascaded and parallel racetrack resonators and ring resonators of
varying radius that demonstrate the Vernier effect. In this study, we designed,
fabricated, and tested multiple types of racetrack resonators to validate the
Vernier effect and its FSR extension capabilities. Our investigations
substantiate that the Vernier effect, based on cascaded and series-coupled
micro-ring resonator (MRR) sensors, can efficiently mitigate intra-channel
cross-talk at higher data rates. This is achieved by providing larger
input-to-through suppression, thus paving the way for future applications.",2305.17620v1
2023-06-05,Dark solitons in Fabry-Perot resonators with Kerr media and normal dispersion,"Ranges of existence and stability of dark cavity-soliton stationary states in
a Fabry-Perot resonator with a Kerr nonlinear medium and normal dispersion are
determined. The Fabry-Perot configuration introduces nonlocal coupling that
shifts the cavity detuning by the round trip average power of the intracavity
field. When compared with ring resonators described by the Lugiato-Lefever
equation, nonlocal coupling leads to strongly detuned dark cavity solitons that
exist over a wide range of detunings. This shift is a consequence of the
counterpropagation of intracavity fields inherent to Fabry-Perot resonators. At
difference with ring resonators, the existence and stability of dark soliton
solutions are dependent on the size and number of solitons in the cavity. We
investigate the effect of nonlocal coupling of Fabry-Perot resonators on
multiple dark solitons and demonstrate long range interactions and
synchronization of temporal oscillations.",2306.02946v1
2023-06-22,High-impedance surface acoustic wave resonators,"Because of their small size, low loss, and compatibility with magnetic fields
and elevated temperatures, surface acoustic wave resonators hold significant
potential as future quantum interconnects. Here, we design, fabricate, and
characterize GHz-frequency surface acoustic wave resonators with the potential
for strong capacitive coupling to nanoscale solid-state quantum systems,
including semiconductor quantum dots. Strong capacitive coupling to such
systems requires a large characteristic impedance, and the resonators we
fabricate have impedance values above 100 $\Omega$. We achieve such high
impedance values by tightly confining a Gaussian acoustic mode. At the same
time, the resonators also have low loss, with quality factors of several
thousand at millikelvin temperatures. These high-impedance resonators are
expected to exhibit large vacuum electric-field fluctuations and have the
potential for strong coupling to a variety of solid-state quantum systems.",2306.12993v2
2023-07-07,Niobate-on-Niobate Resonators with Aluminum Electrodes,"In this work, we have successfully engineered and examined suspended
laterally vibrating resonators (LVRs) on a lithium niobate thin film on lithium
niobate carrier wafer (LN-on-LN) platform, powered by aluminum interdigital
transducers (IDTs). Unlike the lithium niobate-on-silicon system, the LN-on-LN
platform delivers a stress-neutral lithium niobate thin film exhibiting the
quality of bulk single crystal. The creation of these aluminum-IDTs-driven
LN-on-LN resonators was achieved utilizing cutting-edge vapor-HF release
techniques. Our testing revealed both symmetric (S0) and sheer horizontal (SH0)
lateral vibrations in the LVR resonators. The resonators displayed a quality
factor (Q) ranging between 500 and 2600, and coupling coefficient $k_{eff}^2$
up to 13.9%. The figure of merit (FOM) $k_{eff}^2 \times Q$ can reach as high
as 294. The yield of these devices proved to be impressively reliable.
Remarkably, our LN-on-LN devices demonstrated a consistently stable temperature
coefficient of frequency (TCF) and good power handling. Given the low thermal
conductivity of lithium niobate, our LN-on-LN technology presents promising
potential for future applications such as highly sensitive uncooled sensors
using monolithic chip integrated resonator arrays.",2307.03358v1
2023-07-11,"No-resonance conditions, random matrices, and quantum chaotic models","In this article we investigate no-resonance conditions for quantum chaotic
and random matrix models. No-resonance conditions are properties on the
spectrum of a model, usually employed as a theoretical tool in the analysis of
late time dynamics. The first order no-resonance condition holds when a
spectrum is non-degenerate, while higher order no-resonance conditions imply
sums of an equal number of energies are non-degenerate outside of permutations
of the indices. The condition is usually assumed to hold for quantum chaotic
models. In this work we use several tests from random matrix theory to
demonstrate that no-resonance conditions are likely to be violated for all
equal sums containing greater than one energy. This is due to the presence of
level-attraction in the spectra after resolving appropriate symmetries. This
result is produced for both a quantum chaotic Hamiltonian and two random matrix
models. We then generalize important bounds in quantum equilibration theory to
a case where the conditions are violated, and to the case of random matrix
models.",2307.05417v2
2023-07-25,Topological dissipative Kerr soliton combs in a valley photonic crystal resonator,"Topological phases have become an enabling role in exploiting new
applications of nonlinear optics in recent years. Here we theoretically propose
a valley photonic crystal resonator emulating topologically protected
dissipative Kerr soliton combs. It is shown that topological resonator modes
can be observed in the resonator. Moreover, we also simulate the dynamic
evolution of the topological resonator with the injection of a continuous-wave
pump laser. We find that the topological optical frequency combs evolve from
Turing rolls to chaotic states, and eventually into single soliton states. More
importantly, such dissipative Kerr soliton combs generated in the resonator are
inborn topologically protected, showing robustness against sharp bends and
structural disorders. Our design supporting topologically protected dissipative
Kerr soliton combs could be implemented experimentally in on-chip
nanofabricated photonic devices.",2307.13233v1
2023-07-31,Coherent electron-vibron interactions in Surface-Enhanced Raman Scattering (SERS),"In this work we identify coherent electron-vibron interactions between
near-resonant and non-resonant electronic levels that contribute beyond
standard optomechanical models for off-resonant or resonance SERS. By
developing an open-system quantum model using first molecular interaction
principles, we show how the Raman interference of both resonant and
non-resonant contributions can provide several orders of magnitude
modifications of the SERS peaks with respect to former optomechanical models
and over the fluorescence backgrounds. This cooperative optomechanical
mechanism allows for generating an enhancement of nonclassical photon pair
correlations between Stokes and anti-Stokes photons, which can be detected by
photon-counting measurements. Our results demonstrate Raman enhancements and
suppressions of coherent nature that significantly impact the standard
estimations of the optomechanical contribution from SERS spectra and their
quantum mechanical observable effects.",2307.16859v4
2023-08-03,Tuning of resonant doublets in coupled optical cavities,"The mode profile of a coupled optical cavity often exhibits a resonant
doublet, which arises from the strong coupling between its sub-cavities.
Traditional readout methods rely on setting fields of different frequencies to
be resonant in either sub-cavity, which is challenging in the case of strong
coupling. In this regime, the coupled cavity behaves as a single resonator, and
a field must be resonant in all its parts. Consequently, specialized sensing
schemes are necessary to control strongly coupled cavities. To address this
issue, we propose a novel technique for the relative measurement of the degrees
of freedom of a strongly coupled cavity. Our approach enables simultaneous
frequency stabilization and fine-tuning of frequency splitting in the resonant
doublet. Overall, our proposed technique offers a promising solution to control
the properties of coupled cavities, facilitating advanced applications in the
fields of gravitational-wave detection, quantum cavity optomechanics, and other
related areas.",2308.02574v1
2023-08-04,Sensitivity in Nanomechanical Pedestal MEMS Cantilever,"Nanomechanical resonator-based sensing devices are used in medical
diagnostics based on their high-frequency dynamic behavior. Cantilevers fall
into the category of Nanomechanical resonators. It also resembles a resonator
whose shape is like that of a nanowire clamped at one end. As the
surface-to-volume ratio of a nanowire resonator increases due to scaling down,
surface stress plays a crucial role in the mechanical behavior of a resonator.
Piezoresistive MEMS cantilevers are used for vapor phase analysis of volatile
compounds and gas. Studies were done to address the mass sensitivity issues and
fractures associated with bioceramic and nanocomposite coatings-based
cantilever resonators. The studies show how the sensing performance can be
determined or tuned. Nanomechanical studies of thin films of SiCN on silicon
were performed. The sharpness of the tip was found to have an influence on the
tip-sample conduction mechanism useful for MEMS applications",2308.02598v1
2023-08-11,Electron resonant interaction with whistler-mode waves around the Earth's bow shock II: the mapping technique,"Electron resonant scattering by high-frequency electromagnetic whistler-mode
waves has been proposed as a mechanism for solar wind electron scattering and
pre-acceleration to energies that enable them to participate in shock drift
acceleration around the Earth's bow shock. However, observed whistler-mode
waves are often sufficiently intense to resonate with electrons nonlinearly,
which prohibits the application of quasi-linear diffusion theory. This is the
second of two accompanying papers devoted to developing a new theoretical
approach for quantifying the electron distribution evolution subject to
multiple resonant interactions with intense whistler-mode wave-packets. In the
first paper, we described a probabilistic approach, applicable to systems with
short wave-packets. For such systems, nonlinear resonant effects can be treated
by diffusion theory, but with diffusion rates different from those of
quasi-linear diffusion. In this paper we generalize this approach by merging it
with a mapping technique. This technique can be used to model the electron
distribution evolution in the presence of significantly non-diffusive resonant
scattering by intense long wave-packets. We verify our technique by comparing
its predictions with results from a numerical integration approach.",2308.05909v1
2023-08-23,Theoretical interpretation of the $Ξ(1620)$ and $Ξ(1690)$ resonances seen in $Ξ_c^+ \to Ξ^- π^+ π^+$ decay,"We study the Belle reaction $\Xi_c^+ \to \Xi^- \pi^+ \pi^+$ looking at the
mass distribution of $\pi^+ \Xi$, where clear signals for the $\Xi(1620)$ and
$\Xi(1690)$ resonances are seen. These two resonances are generated dynamically
from the interaction in coupled channels of $\pi \Xi, \bar K \Lambda, \bar K
\Sigma$ and $\eta \Xi$ within the chiral unitary approach. Yet, the weak decay
process at the quark level, together with the hadronization to produce pairs of
mesons, does not produce the $\pi \pi \Xi$ final state. In order to produce
this state one must make transitions from the $\bar K \Lambda, \bar K \Sigma$
and $\eta \Xi$ components to $\pi \Xi$, and this interaction is what produces
the resonances. So, the reaction offers a good test for the molecular picture
of these resonances. Adding the contribution of the $\Xi^*(1530)$ and some
background we are able to get a good reproduction of the mass distribution
showing the signatures of the two resonances as found in the experiment.",2308.11879v2
2023-08-26,Spurious-Free Lithium Niobate Bulk Acoustic Resonator for Piezoelectric Power Conversion,"Recently, piezoelectric power conversion has shown great benefits from
replacing the bulky and lossy magnetic inductor in a traditional power
converter with a piezoelectric resonator due to its compact size and low loss.
However, the converter performance is ultimately limited by existing resonator
designs, specifically by moderate quality factor (Q), moderate
electromechanical coupling (kt2), and spurious modes near resonance. This work
reports a spurious-free lithium niobate (LiNbO3) thickness-extensional mode
bulk acoustic resonator design, demonstrating Q of 4000 and kt2 of 30% with a
fractional suppressed region of 62%. We first propose a novel grounded ring
structure for spurious-free resonator design, then validate its performance
experimentally. Upon further work, this design could be extended to
applications requiring spurious suppression, such as filters, tunable
oscillators, transformers, etc.",2308.13902v1
2023-09-09,Optical trapping based on microring resonators with transverse slot structure,"Over the past few decades, optical manipulation has emerged as a highly
successful tool in various fields, such as biology, micro/nanorobotics, and
physics. Among the different techniques, the transverse slot optical waveguide
has shown remarkable potential in enhancing the field and significantly
improving optical trapping capabilities. Additionally, microring resonators
have demonstrated the ability to enhance the field at specific resonance
wavelengths, enabling the manipulation and capture of particles. In this study,
we investigated the impact of the structure on nanoparticle capture by
introducing a 50 nm transverse slot in a 5 {\mu}m microring resonator. Through
the integration of a transverse slot in the microring resonator, we observed a
substantial increase in the maximum bound optical power for a nanosphere with a
refractive index of 1.6 and a diameter of 50 nm, reaching 3988.8 pN/W. This
value is 2292 times higher than the maximum optical force in a straight
waveguide and 2.266 times higher than the maximum optical force in a microring
resonator. The proposed structure significantly enhances the optical trapping
capabilities for nanoscale particles, thus paving the way for the development
of advanced micro/nanomanipulation techniques.",2309.05677v1
2023-09-20,Rare decays of $B_d$ mesons into four charged leptons in the Standard Model,"We present first theoretical predictions for various observables related to
the $\bar B_d \to \mu^+ \mu^- e^+ e^-$ decay within the framework of the
Standard Model. Our study encompasses the branching ratios, differential
distributions, and forward-backward leptonic asymmetries. To obtain these
predictions, we account for several contributions: resonance contribution from
$\rho(770)$ and significant contribution $\omega(782)$; contributions from four
charmonium resonances: $\psi(3770)$, $\psi(4040)$, $\psi(4160)$, and
$\psi(4415)$; additional contributions from the ""tails"" of $J/\psi$ and
$\psi(2S)$ resonances; non-resonant contributions arising from virtual photon
emission by a $b$-quark of $B_d$ meson, bremsstrahlung, and weak annihilation.
In our calculations we employ the model of vector meson dominance (VMD) to
assess the resonance contributions accurately. We provide the predictions for
the branching ratio of the $\bar B_d \to \mu^+ \mu^- e^+ e^-$ decay both with
and without the resonant contribution from $\omega(782)$.",2309.11164v1
2023-09-21,Tunable Rectangular Resonant Cavities for Axion Haloscopes,"Axions are a compelling dark matter candidate, and one of the primary
techniques employed to search for them is the axion haloscope, in which a
resonant cavity is deployed inside a strong magnetic field so that some of the
surrounding axions may convert into photons via the inverse Primakoff effect
and become trapped inside the resonator. Resonant cavity design is critical to
the sensitivity of a haloscope, and several geometries have been utilised and
proposed. Here we consider a relatively simple concept - a rectangular resonant
cavity with a tunable wall - and compare it to the standard tuning rod-type
resonators employed in the field. We find that the rectangular cavities support
similar modes to cylindrical tuning rod cavities, and have some advantages in
terms of axion sensitivity and practicality, particularly when moving to higher
frequencies which are of great and growing interest in the international axion
dark matter community.",2309.12098v1
2023-09-25,Charmonium $χ_{c0}$ and $χ_{c2}$ resonances in coupled-channel scattering from lattice QCD,"In order to explore the spectrum of hidden-charm scalar and tensor
resonances, we study meson-meson scattering with $J^{PC}=0^{++}, 2^{++}$ in the
charmonium energy region using lattice QCD. Employing a light-quark mass
corresponding to $m_\pi \approx 391$ MeV, we determine coupled-channel
scattering amplitudes up to around 4100 MeV considering all kinematically
relevant channels consisting of a pair of open-charm mesons or a charmonium
meson with a light meson. A single isolated scalar resonance near 4000 MeV is
found with large couplings to $D\bar{D}$, $D_s \bar{D}_s$ and the kinematically
closed $D^* \bar{D}^*$ channel. A single tensor resonance at a similar mass
couples strongly to $D\bar{D}$, $D\bar{D}^*$ and $D^* \bar{D}^*$. We compare
the extracted resonances to contemporary experimental candidate states,
previous lattice results and theoretical modeling. In contrast to several other
studies, we do not find any significant feature in the scalar amplitudes
between the ground state $\chi_{c0}(1P)$ and the resonance found around 4000
MeV.",2309.14071v1
2023-10-04,Unleashing infinite momentum bandgap using resonant material systems,"The realization of photonic time crystals is a major opportunity but also
comes with significant challenges. The most pressing one, potentially, is the
requirement for a substantial modulation strength in the material properties to
create a noticeable momentum bandgap. Reaching that noticeable bandgap in
optics is highly demanding with current, and possibly also future, material
platforms since their modulation strength is small by tendency. Here we
demonstrate that by introducing temporal variations in a resonant material, the
momentum bandgap can be drastically expanded, potentially approaching infinity
with modulation strengths in reach with known low-loss materials and realistic
laser pump powers. The resonance can emerge from an intrinsic material
resonance or a suitably spatially structured material supporting a structural
resonance. Our concept is validated for resonant bulk media and optical
metasurfaces and paves the way toward the first experimental realizations of
photonic time crystals.",2310.02786v1
2023-10-14,Coupled metamaterial-phonon terahertz range polaritons in a topological insulator,"We report terahertz time-domain spectroscopy (TDTS) experiments demonstrating
strong light-matter coupling in a terahertz (THz) LC-metamaterial in which the
phonon resonance of a topological insulator (TI) thin film is coupled to the
photonic modes of an array of electronic split-ring resonators. As we tune the
metamaterial resonance frequency through the frequency of the low frequency
$\alpha$ mode of (Bi$_x$Sb$_{1-x}$)$_2$Te$_3$ (BST), we observe strong mixing
and level repulsion between phonon and metamaterial resonance. This hybrid
resonance is a phonon polariton. We observe a normalized coupling strength,
$\eta$ = $\Omega_R$/$\omega_c$ $\approx$ 0.09, using the measured vacuum Rabi
frequency and cavity resonance. Our results demonstrate that one can tune the
mechanical properties of materials by changing their electromagnetic
environment and therefore modify their magnetic and topological degrees of
freedom via coupling to the lattice in this fashion.",2310.09481v2
2023-10-16,Multiplicative noise induced bistability and stochastic resonance,"Stochastic resonance is a well established phenomenon, which proves relevant
for a wide range of applications, of broad trans-disciplinary breath. Consider
a one dimensional bistable stochastic system, characterized by a deterministic
double well potential and shaken by an additive noise source. When subject to
an external periodic drive, and for a proper choice of the noise strength, the
system swings regularly between the two existing deterministic fixed points,
with just one switch for each oscillation of the imposed forcing term. This
resonant condition can be exploited to unravel weak periodic signals, otherwise
inaccessible to conventional detectors. Here, we will set to revisit the
stochastic resonance concept by operating in a modified framework where
bistability is induced by the nonlinear nature of the multiplicative noise. A
candidate model is in particular introduced which fulfils the above
requirements while allowing for analytical progress to be made. Working with
reference to this case study, we elaborate on the conditions for the onset of
the generalized stochastic resonance mechanism. As a byproduct of the analysis,
a novel resonant regime is also identified which displays no lower bound for
the frequencies that can be resolved, at variance with the traditional setting.",2310.10435v1
2023-10-25,Kerr-Nonlinearity Assisted Exceptional Point Degeneracy in a Detuned PT-Symmetric System,"Systems operating at exceptional points (EPs) are highly responsive to small
perturbations, making them suitable for sensing applications. Although this
feature impedes the system working exactly at an EP due to imperfections
arising during the fabrication process. We propose a fast self-tuning scheme
based on Kerr nonlinearity in a coupled dielectric resonator excited through a
waveguide placed in the near-field of the resonators. We show that in a coupled
resonator with unequal Kerr-coefficients, initial distortion from EP regime can
be completely compensated. It provides an opportunity to reach very close to
the EP in a coupled resonator with detuned resonant frequencies via tuning the
intensity of the incident wave. Using time-modulation of the incident wave in
nonlinear systems to control both the gain or loss, and resonant frequencies
can be a possible approach to fully control the parameters close to an EP.",2310.16259v2
2023-11-27,Near-resonant nuclear spin detection with high-frequency mechanical resonators,"Mechanical resonators operating in the high-frequency regime have become a
versatile platform for fundamental and applied quantum research. Their
exceptional properties, such as low mass and high quality factor, make them
also very appealing for force sensing experiments. In this Letter, we propose a
method for detecting and ultimately controlling nuclear spins by directly
coupling them to high-frequency resonators via a magnetic field gradient.
Dynamical backaction between the sensor and an ensemble of nuclear spins
produces a shift in the sensor's resonance frequency, which can be measured to
probe the spin ensemble. Based on analytical as well as numerical results, we
predict that the method will allow nanoscale magnetic resonance imaging with a
range of realistic devices. At the same time, this interaction paves the way
for new manipulation techniques, similar to those employed in cavity
optomechanics, enriching both the sensor's and the spin ensemble's features.",2311.16273v1
2023-12-05,Pion axioproduction revisited,"In this work, we extend the analysis of the pion axioproduction, $aN \to
\pi{N}$, to include the impact of the Roper resonance $N^*(1440)$ together the
previously studied $\Delta(1232)$ resonance. Our theoretical framework is
chiral perturbation theory with explicit resonance fields to account for their
respective impacts. We find that the Roper resonance also leads to an
enhancement of the cross section within its energy range for various axion
models. This enhancement provided by the Roper maintains stability even when
the parameter $\sin^2{\beta}$ of the DFSZ model undergoes variations. In
contrast, the enhancement given by the $\Delta$ gradually diminishes and
finally disappears as $\sin^2{\beta}$ approaches $1$. Furthermore, the
resonance peaks given by the $\Delta$ are approximately the same in both the
KSVZ model and the DFSZ model with $\sin^2{\beta} = \tfrac{1}{2}$, while the
resonance peak given by the Roper in the former model is much more pronounced.",2312.02564v1
2023-12-06,"Exploring Charmonium-like Molecular Resonances from Deeply Bound $D \bar D_1$, $D^* \bar D_1$, and $D^* \bar D_2^*$ Molecules","Resonance phenomena are well-known in various areas of physics. Based on the
scenario of decoding the mysterious $Y(4220)$, $Y(4360)$, and $\psi(4415)$
states as the $S$-wave deeply bound $D \bar D_1$, $D^* \bar D_1$, and $D^* \bar
D_2^*$ molecules, respectively, we predict the existence of charmonium-like
molecular resonances by utilizing the one-boson-exchange model and the complex
scaling method. A conclusive finding is that the existence of deeply bound
charmonium-like molecules must indicate the existence of $S$-wave deeply bound
$C$-parity partners. While no radially excited $S$-wave resonances were found,
our results suggest the existence of $P$-wave $D \bar D_1$, $D^* \bar D_1$, and
$D^* \bar D_2^*$ molecular resonances. We expect future experiments to search
for such molecular resonances predicted here, which will not only enrich the
ongoing construction of ""Particle Zoo 2.0"" but also provide a crucial hint to
scrutinize the assignments of hadronic molecules to the $Y(4220)$, $Y(4360)$,
and $\psi(4415)$ states.",2312.03512v1
2023-12-06,The Extended Resonant Modal Theory and Its Applications,"In this paper, we extend the resonant modal theory (RMT) developed previously
for a metal object to an arbitrary source region consisting of metals,
dielectrics, or the combination of both. The influences of dielectrics on the
fields are replaced by equivalent volume sources through the use of the
compensation theorem in electromagnetic theory. The resonant frequencies can be
determined by finding the roots of the determinant of the matrix resulted from
the discretization of the real homogeneous volume-surface integral equation
derived from the requirement that the difference of stored field energies in
the source region vanishes. As applications of the extended RMT, three examples
have been investigated. The first example is a dielectric resonator antenna,
and is designed by exciting the first resonant mode of the composite structure
in which the dielectric cylinder is combined with a conformal metallic strip.
The second example is a dual-band dielectric-coated metallic wire antenna. The
third example studies the resonant modes of a rectangular patch antenna.",2312.03582v1
2023-12-07,Quasi-Babinet principle in dielectric resonators and Mie voids,"Advancing resonant nanophotonics requires novel building blocks. Recently,
cavities in high-index dielectrics have been shown to resonantly confine light
inside a lower-index region. These so-called Mie voids represent a counterpart
to solid high-index dielectric Mie resonators, offering novel functionality
such as resonant behavior in the ultraviolet spectral region. However, the
well-known and highly useful Babinet's principle, which relates the scattering
of solid and inverse structures, is not strictly applicable for this dielectric
case as it is only valid for infinitesimally thin perfect electric conductors.
Here, we show that Babinet's principle can be generalized to dielectric systems
within certain boundaries, which we refer to as the quasi-Babinet principle and
demonstrate for spherical and more generically shaped Mie resonators.
Limitations arise due to geometry-dependent terms as well as material frequency
dispersion and losses. Thus, our work not only offers deeper physical insight
into the working mechanism of these systems but also establishes simple design
rules for constructing dielectric resonators with complex functionalities from
their complementary counterparts.",2312.04082v1
2023-12-07,Simulations of Non-Integer Upconversion in Resonant Six-Wave Scattering,"Resonant upconversion through a sixth order relativistic nonlinearity
resulting in a unique resonance was recently proposed [V. M. Malkin and N. J.
Fisch, Physical Review E 108, 045208 (2023)]. The high order resonance is a
unique non-integer multiple of a driving pump frequency resulting in a
frequency upshift by a factor of $\approx 3.73$. We demonstrate the presence,
unique requirements, and growth of this mode numerically. Through tuning waves
to high amplitude, in a mildly underdense plasma, the six-photon process may
grow more than other non-resonant, but lower order processes. The growth of the
high frequency mode remains below the nonlinear growth regime. However,
extending current numerical results to more strongly coupled resonances with
longer pulse propagation distances suggests a pathway to significant
upconversion.",2312.04699v1
2023-12-14,Composite resonances at a 10 TeV muon collider,"We investigate the reach for resonances of the composite Higgs models at a 10
TeV \mu^+\mu^- collider with up to 10 ab^{-1} luminosity. The strong dynamics
sector is modeled by the minimal coset SO(5)/SO(4), where vector resonances are
in (3, 1) of SO(4) and fermions are in (2, 2). Various production and decay
channels are studied. For the spin-1 resonances, the projections are made based
on the radiative return and vector boson fusion production channels. The muon
collider can cover most of the kinematically allowed mass range and can measure
the coupling g_\rho to percent level. For the fermionic resonances (i.e. the
top partners), pair production easily covers the resonance mass below 5 TeV,
while single production extends the reach to 6 TeV for a small \xi = 0.015.",2312.09117v1
2024-01-02,Identification of Secondary Resonances of Nonlinear Systems using Phase-Locked Loop Testing,"One unique feature of nonlinear dynamical systems is the existence of
superharmonic and subharmonic resonances in addition to primary resonances. In
this study, an effective vibration testing methodology is introduced for the
experimental identification of these secondary resonances. The proposed method
relies on phase-locked loop control combined with adaptive filters for online
Fourier decomposition. To this end, the concept of a resonant phase lag is
exploited to define the target phase lag to be followed during the experimental
continuation process. The method is demonstrated using two systems featuring
cubic nonlinearities, namely a numerical Duffing oscillator and a physical
experiment comprising a clamped-clamped thin beam. The obtained results
highlight that the control scheme can accurately characterize secondary
resonances as well as track their backbone curves. A particularly salient
feature of the developed algorithm is that, starting from the rest position, it
facilitates an automatic and smooth dynamic state transfer toward one point of
a subharmonic isolated branch, hence, inducing branch switching.",2401.01151v1
2024-01-12,Near-resonant light scattering by an atom in a state-dependent trap,"The optical properties of a fixed atom are well-known and investigated. For
example, the extraordinarily large cross section of a single atom as seen by a
resonant photon is essential for quantum optical applications. Mechanical
effects associated with light scattering are also well-studied, forming the
basis of laser cooling and trapping, for example. Despite this, there is one
fundamental problem that surprisingly has not been extensively studied, yet is
relevant to a number of emerging quantum optics experiments. In these
experiments, the ground state of the atom experiences a tight optical trap
formed by far-off-resonant light, to facilitate efficient interactions with
near-resonant light. However, the excited state might experience a different
potential, or even be anti-trapped. Here, we systematically analyze the effects
of unequal trapping on near-resonant atom-light interactions. In particular, we
identify regimes where such trapping can lead to significant excess heating,
and a reduction of total and elastic scattering cross sections associated with
a decreased atom-photon interaction efficiency. Understanding these effects can
be valuable for optimizing quantum optics platforms where efficient atom-light
interactions on resonance are desired, but achieving equal trapping is not
feasible.",2401.06753v1
2024-02-12,Spin orbit resonance cascade via core shell model. Application to Mercury and Ganymede,"We discuss a model describing the spin orbit resonance cascade. We assume
that the primary has a two-layer (core-shell) structure: it is composed by a
thin solid crust and an inner and heavier solid core that are interacting due
to the presence of a fluid interface. We assume two sources of dissipation: a
viscous one, depending on the relative angular velocity between core and crust
and a tidal one, smaller than the first, due to the viscoelastic structure of
the core. We show how these two sources of dissipation are needful for the
capture in spin-orbit resonance. The crust and the core fall in resonance with
different time scales if the viscous coupling between them is big enough.
Finally, the tidal dissipation of the viscoelastic core, decreasing the
eccentricity, brings the system out of the resonance in a third very long time
scale. This mechanism of entry and exit from resonance ends in the $1:1$ stable
state.",2402.07650v1
2024-02-21,Automated Resonance Identification in Nuclear Data Evaluation,"Global and national efforts to deliver high-quality nuclear data to users
have a broad impact across applications such as national security, reactor
operation, basic science, medical fields, and more. Cross section evaluation is
a large part this effort as it combines theory and experiment to produce
suggested values and uncertainty for reaction probabilities. In most isotopes,
the cross section exhibits resonant behavior in what is called the resonance
region of incident neutron energy. Resonance region evaluation is a specialized
type of nuclear data evaluation that can require significant, manual effort and
months of time from expert scientists. In this article, non-convex, non-linear
optimization methods are combined with concepts of inferential statistics to
infer a set of optimized resonance models from experimental data in an
automated manner that is not dependent on prior evaluation(s). This methodology
aims to enhance the workflow of a resonance evaluator by minimizing time,
effort, and prior biases while improving reproducibility and document-ability,
addressing widely recognized challenges in the field.",2402.14122v1
2024-03-07,An efficient method for calculating resonant modes in biperiodic photonic structures,"Many photonic devices, such as photonic crystal slabs, cross gratings, and
periodic metasurfaces, are biperiodic structures with two independent periodic
directions, and are sandwiched between two homogeneous media. Many applications
of these devices are closely related to resonance phenomena. Therefore,
efficient computation of resonant modes is crucial in device design and
structure analysis. Since resonant modes satisfy outgoing radiation conditions,
perfectly matched layers (PMLs) are usually used to truncate the unbounded
spatial variable perpendicular to the periodic directions. In this paper, we
develop an efficient method without using PMLs to calculate resonant modes in
biperiodic structures. We reduce the original eigenvalue problem to a small
matrix nonlinear eigenvalue problem which is solved by the contour integral
method. Numerical examples show that our method is efficient with respect to
memory usage and CPU time, free of spurious solutions, and determines
degenerate resonant modes without any difficulty.",2403.04459v1
2024-03-07,Enhanced near-complete absorption of electromagnetic waves by dual resonance in a magnetized plasma,"There has been significant interest lately in the study of Electromagnetic
(EM) waves interacting with magnetized plasmas. The variety of resonances and
the existence of several pass and stop bands in the dispersion curve for
different orientations of the magnetic field offer new mechanisms of EM wave
energy absorption (PhysRevE.105.055209,
Juneja_2023,vashistha2022localized,vashistha2020new). By an appropriate choice
of inhomogeneous magnetic field, one can construct a configuration wherein the
same EM wave pulse encounters more than one resonance in the plasma. A 2-D
Particle - In - Cell (PIC) simulation using the OSIRIS4.0 platform has been
carried out for the case of dual resonance. It is observed that in the presence
of dual resonance, there is a significant enhancement in leading to almost
complete absorption of laser energy by the plasma in certain cases. A detailed
study of the influence of the relative location of the resonances, the effect
of high input EM wave intensity, etc., has also been carried out.",2403.04462v1
2024-03-11,Active Control of Bound States in the Continuum in Toroidal Metasurfaces,"The remarkable properties of toroidal metasurfaces, featuring ultrahigh-Q
bound states in the continuum (BIC) resonances and nonradiating anapole modes,
have garnered significant attention. The active manipulation of toroidal
resonance characteristics offers substantial potential for advancing tunable
metasurfaces. Our study specifically explores the application of vanadium
dioxide, a widely used phase change material in active photonics and
room-temperature bolometric detectors, to control BIC resonances in toroidal
metasurfaces. The phase change transition of vanadium dioxide occurs in a
narrow temperature range providing a large variation in material resistivity.
Through heating thin film patches of vanadium dioxide integrated into a
metasurface comprising gold split-ring resonators on a sapphire substrate, we
achieve remarkable control over the amplitude and frequency of toroidal dipole
BIC resonances due to their high sensitivity to losses present in the system.
Breaking the symmetry of meta-atoms reveals enhanced tunability. The predicted
maximum change in the amplitude of toroidal dipole BIC resonances reaches 14 dB
with a temperature variation of approximately 10oC. The proposed tunable
metasurface holds promise for various applications, including active photonic
systems and room temperature bolometers.",2403.06345v1
2024-03-22,From pole parameters to line shapes and branching ratios,"Resonances are uniquely characterized by their complex pole locations and the
corresponding residues. In practice, however, resonances are typically
identified experimentally as structures in invariant mass distributions, with
branching fractions of resonances determined as ratios of count rates. To make
contact between these quantities it is necessary to connect line shapes and
resonance parameters. In this work we propose such a connection and illustrate
the formalism with detailed studies of the $\rho(770)$ and $f_0(500)$
resonances. Based on the line shapes inferred from the resonance parameters
along these lines, expressions for partial widths and branching ratios are
derived and compared to other approaches in the literature.",2403.15539v1
2024-04-06,The inverse Faraday effect at Mie resonances,"Nowadays, dielectric nanophotonics enables almost lossless resonant
interaction between light and matter at the nanoscale. We show both
theoretically and by electromagnetic simulations, that the peculiar nature of
Mie-resonance induced effective magnetic fields contrasts sharply with the
optomagnetism of smooth bulk materials. Mie resonances produce strongly
nonuniform effective magnetic fields generated by the inverse Faraday effect.
Different orders of optical resonances are characterized by different types of
the effective magnetic field patterns. The number of point-like inverse Faraday
effect sources can be controlled by adjusting the pump wavelength, allowing for
the selective launch of spin waves with submicron wavelengths. A distinguish
feature of the Mie-resonance-induced effective magnetic fields is the vortex
structure that can be used for the magnetic skyrmion generation. The proposed
approach considerably broadens the scope of nanoscale optomagnetism.",2404.04569v1
2003-01-22,Resonance Occupation in the Kuiper Belt: Case Examples of the 5:2 and Trojan Resonances,"As part of our ongoing Deep Ecliptic Survey (DES) of the Kuiper belt, we
report on the occupation of the 1:1 (Trojan), 4:3, 3:2, 7:4, 2:1, and 5:2
Neptunian mean-motion resonances (MMRs). The occupation of the 1:1 and 5:2 MMRs
is not easily understood within the standard model of resonance sweeping by a
migratory Neptune over an initially dynamically cold belt. Our dynamically hot,
5:2 resonant objects can librate with modest amplitudes of 90 deg within the
resonance for at least 1 Gyr. Their trajectories cannot be explained by close
encounters with Neptune alone, given the latter's current orbit. The hot orbits
of such 5:2 resonant KBOs, unlike hot orbits of previously known resonant KBOs,
may imply that these objects were pre-heated to large inclination and large
eccentricity prior to resonance capture by a migratory Neptune. Our first
discovered Neptunian Trojan, 2001QR322, may not owe its existence to Neptune's
migration at all. The trajectory of 2001QR322 is remarkably stable; the object
can undergo tadpole-type libration about Neptune's leading Lagrange (L4) point
for at least 1 Gyr with a libration amplitude of 24 deg. Trojan capture
probably occurred while Neptune accreted the bulk of its mass. For an assumed
albedo of 12--4%, our Trojan is 130--230 km in diameter. Model-dependent
estimates place the total number of Neptune Trojans resembling 2001QR322 at
20--60. Their existence might rule out violent orbital histories for Neptune.",0301458v3
2008-12-28,Orbital resonances in discs around braneworld Kerr black holes,"Rotating black holes in the brany universe of the Randall-Sundrum type are
described by the Kerr geometry with a tidal charge b representing the
interaction of the brany black hole and the bulk spacetime. For b<0 rotating
black holes with dimensionless spin a>1 are allowed. We investigate the role of
the tidal charge b in the orbital resonance model of QPOs in black hole
systems. The orbital Keplerian, the radial and vertical epicyclic frequencies
of the equatorial, quasicircular geodetical motion are given and their radial
profiles are discussed. The resonant conditions are given in three
astrophysically relevant situations: for direct (parametric) resonances, for
the relativistic precession model, and for some trapped oscillations of the
warped discs, with resonant combinational frequencies. It is shown, how b could
influence matching of the observational data indicating the 3:2 frequency ratio
observed in GRS 1915+105 microquasar with prediction of the orbital resonance
model; limits on allowed range of the black hole parameters a and b are
established. The ""magic"" dimensionless black hole spin enabling presence of
strong resonant phenomena at the radius where \nu_K:\nu_{\theta}:\nu_r=3:2:1 is
determined in dependence on b. Such strong resonances could be relevant even in
sources with highly scattered resonant frequencies, as those expected in Sgr
A*. The specific values of a and b are given also for existence of specific
radius where \nu_K:\nu_{\theta}:\nu_r=s:t:u with 5>=s>t>u being small natural
numbers. It is shown that for some ratios such situation is impossible in the
field of black holes. We can conclude that analysing the microquasars
high-frequency QPOs in the framework of orbital resonance models, we can put
relevant limits on the tidal charge of brany Kerr black holes.",0812.5066v1
2010-06-12,Resonant Absorption of Fast Magnetoacoustic Waves due to Coupling into the Slow and Alfven Continua in the Solar Atmosphere,"Resonant absorption of fast magnetoacoustic (FMA) waves in an inhomogeneous,
weakly dissipative, one-dimensional planar, strongly anisotropic and dispersive
plasma is investigated. The magnetic configuration consists of an inhomogeneous
magnetic slab sandwiched between two regions of semi-infinite homogeneous
magnetic plasmas. Laterally driven FMA waves penetrate the inhomogeneous slab
interacting with the localised slow or Alfven waves present in the
inhomogeneous layer and are partly reflected, dissipated and transmitted by
this region. The presented research aims to find the coefficient of wave energy
absorption under solar chromospheric and coronal conditions. Numerical results
are analyzed to find the coefficient of wave energy absorption at both the slow
and Alfven resonance positions. The mathematical derivations are based on the
two simplifying assumptions that (i) nonlinearity is weak, and (ii) the
thickness of the inhomogeneous layer is small in comparison to the wavelength
of the wave, i.e. we employ the so-called long wavelength approximation. Slow
resonance is found to be described by the nonlinear theory, while the dynamics
at the Alfven resonance can be described within the linear framework. We
introduce a new concept of coupled resonances, which occurs when two different
resonances are in close proximity to each other, causing the incoming wave to
act as though it has been influenced by the two resonances simultaneously. Our
results show that the wave energy absorption is heavily dependent on the angle
of the incident wave in combination with the inclination angle of the
equilibrium magnetic field. In addition, it is found that FMA waves are very
efficiently absorbed at the Alfven resonance under coronal conditions. Under
chromospheric conditions the FMA waves are far less efficiently absorbed,
despite an increase in efficiency due to the coupled resonances.",1006.2427v1
2012-03-13,Formation of '3D' multiplanet systems by dynamical disruption of multiple-resonance configurations,"Assuming that giant planets are formed in thin protoplanetary discs, a '3D'
system can form, provided that the mutual inclination is excited by some
dynamical mechanism. Resonant interactions and close planetary encounters are
thought to be the primary inclination-excitation mechanisms, resulting in a
resonant and non-resonant system, respectively. Here we propose an alternative
formation scenario, starting from a system composed of three giant planets in a
nearly coplanar configuration. As was recently shown for the case of the Solar
system, planetary migration in the gas disc (Type II migration) can force the
planets to become trapped in a multiply resonant state. We simulate this
process, assuming different values for the planetary masses and mass ratios. We
show that such a triple resonance generally becomes unstable as the resonance
excites the eccentricities of all planets and planet-planet scattering sets in.
One of the three planets is typically ejected from the system, leaving behind a
dynamically 'hot' (but stable) two-planet configuration. The resulting
two-planet systems typically have large values of semimajor axial ratios (a1/a2
< 0.3), while the mutual inclination can be as high as 70{\deg}, with a median
of \sim30{\deg}. A small fraction of our two-planet systems (\sim5 per cent)
ends up in the stability zone of the Kozai resonance. In a few cases, the
triple resonance can remain stable for long times and a '3D' system can form by
resonant excitation of the orbital inclinations; such a three-planet system
could be stable if enough eccentricity damping is exerted on the planets.
Finally, in the single-planet resulting systems, which are formed when two
planets are ejected from the system, the inclination of the planet's orbital
plane with respect to the initial invariant plane -presumably the plane
perpendicular to the star's spin axis- can be as large as \sim40{\deg}.",1203.2955v1
2012-08-29,The Orbital Stability of Planets Trapped in the First-Order Mean-Motion Resonances,"Many extrasolar planetary systems containing multiple super-Earths have been
discovered. N-body simulations taking into account standard type-I planetary
migration suggest that protoplanets are captured into mean-motion resonant
orbits near the inner disk edge at which the migration is halted. Previous
N-body simulations suggested that orbital stability of the resonant systems
depends on number of the captured planets. In the unstable case, through close
scattering and merging between planets, non-resonant multiple systems are
finally formed. In this paper, we investigate the critical number of the
resonantly trapped planets beyond which orbital instability occurs after disk
gas depletion. We find that when the total number of planets ($N$) is larger
than the critical number ($N_{\rm crit}$), crossing time that is a timescale of
initiation of the orbital instability is similar to non-resonant cases, while
the orbital instability never occurs within the orbital calculation time
($10^8$ Kepler time) for $N\leq N_{\rm crit}$. Thus, the transition of crossing
time across the critical number is drastic. When all the planets are trapped in
7:6 resonance of adjacent pairs, $N_{\rm crit} = 4$. We examine the dependence
of the critical number of 4:3, 6:5 and 8:7 resonance by changing the orbital
separation in mutual Hill radii and planetary mass. The critical number
increases with increasing the orbital separation in mutual Hill radii with
fixed planetary mass and increases with increasing planetary mass with fixed
the orbital separation in mutual Hill radii. We also calculate the case of a
system which is not composed of the same resonance. The sharp transition of the
stability can be responsible for the diversity of multiple super-Earths
(non-resonant or resonant), that is being revealed by $Kepler$ mission.",1208.5937v1
2013-04-27,Two Super-Earths Orbiting the Solar Analogue HD41248 on the edge of a 7:5 Mean Motion Resonance,"The number of multi-planet systems known to be orbiting their host stars with
orbital periods that place them in mean motion resonances is growing. For the
most part, these systems are in first-order resonances and dynamical studies
have focused their efforts towards understanding the origin and evolution of
such dynamically resonant commensurabilities. We report here the discovery of
two super-Earths that are close to a second-order dynamical resonance, orbiting
the metal-poor ([Fe/H]=-0.43 dex) and inactive G2V star HD41248. We analysed 62
HARPS archival radial velocities for this star, that until now, had exhibited
no evidence for planetary companions. Using our new Bayesian Doppler signal
detection algorithm, we find two significant signals in the data, with periods
of 18.357 days and 25.648 days, indicating they could be part of a 7:5
second-order mean motion resonance. Both semi-amplitudes are below 3m/s and the
minimum masses of the pair are 12.3 and 8.6Mearth, respectively. Our
simulations found that apsidal alignment stabilizes the system, and even though
libration of the resonant angles was not seen, the system is affected by the
presence of the resonance and could yet occupy the 7:5 commensurability, which
would be the first planetary configuration in such a dynamical resonance. Given
the multitude of low-mass multiplanet systems that will be discovered in the
coming years, we expect more of these second-order resonant configurations will
emerge from the data, highlighting the need for a better understanding of the
dynamical interactions between forming planetesimals.",1304.7374v2
2013-07-12,On the stability of dust orbits in mean motion resonances with considered perturbation from an interstellar wind,"Circumstellar dust particles can be captured in a mean motion resonance with
a planet and simultaneously be affected by non-gravitational effects. It is
possible to describe the secular variations of a particle orbit in the mean
motion resonance analytically using averaged resonant equations. We derive the
averaged resonant equations from the equations of motion in near-canonical
form. The secular variations of the particle orbit depending on the orientation
of the orbit in space are taken into account. The averaged resonant equations
can be derived/confirmed also from Lagrange's planetary equations. We apply the
derived theory to the case when the non-gravitational effects are the
Poynting--Robertson effect, the radial stellar wind, and an interstellar wind.
The analytical and numerical results obtained are in excellent agreement. We
found that the types of orbits correspond to libration centers of the
conservative problem. The averaged resonant equations can lead to a system of
equations which hold for stationary points in a subset of resonant variables.
Using this system we show analytically that for the considered
non-gravitational effects, all stationary points should correspond to orbits
which are stationary in interplanetary space after an averaging over a synodic
period. In an exact resonance, the stationary orbits are stable. The stability
is achieved by a periodic repetition of the evolution during the synodic
period. Numerical solutions of this system show that there are no stationary
orbits for either the exact or non-exact resonances.",1307.3350v5
2013-12-16,Non-smooth Chemical Freeze-out and Apparent Width of Wide Resonances and Quark Gluon Bags in a Thermal Environment,"Here we develop the hadron resonance gas model with the Gaussian width of
hadron resonances. This model allows us to treat the usual hadrons and the
quark gluon bags on the same footing and to study the stability of the results
obtained within different formulations of the hadron resonance gas model. In
this work we perform a successful fit of 111 independent hadronic multiplicity
ratios measured for $\sqrt{s_{NN}} $= 2.7- 200 GeV. We demonstrate that in a
narrow range of collision energy $\sqrt{s_{NN}} =$ 4.3-4.9 GeV there exist
peculiar irregularities in various thermodynamic quantities found at chemical
freeze-out. The most remarkable irregularity is an unprecedented jump of the
number of effective degrees of freedom observed in this narrow energy range
which is seen in all realistic versions of the hadron resonance gas model.
Therefore, the developed concept is called the non-smooth chemical freeze-out.
We are arguing that these irregularities evidence for the possible formation of
quark gluon bags. In order to develop other possible signals of their formation
here we study the apparent width of wide hadronic resonances and quark gluon
bags in a thermal environment. Two new effects generated for the wide
resonances and quark gluon bags by a thermal medium are discussed here: the
near threshold thermal resonance enhancement and the near threshold thermal
resonance sharpening. On the basis of the new effects we argue that the most
optimistic chance to find experimentally the quark gluon bags may be related to
their sharpening and enhancement in a thermal medium. In this case the wide
quark gluon bags may appear directly or in decays as narrow resonances that are
absent in the tables of elementary particles and that have the apparent width
about 50-120 MeV and the mass about or above 2.5 GeV.",1312.4367v2
2014-10-06,"Trojan resonant dynamics, stability, and chaotic diffusion, for parameters relevant to exoplanetary systems","We investigate the dynamics of small trojan exoplanets in domains of
secondary resonances within the tadpole domain of motion. We consider the limit
of a massless trojan companion of a giant planet. Without other planets, this
is a case of the elliptic restricted three body problem (ERTBP). The presence
of more planets (the restricted multi-planet problem, RMPP) induces new direct
and indirect secular effects on the trojan's dynamics. In the theoretical part
of this paper, we develop a Hamiltonian formalism in action-angle variables,
which allows to treat in a unified way resonant dynamics and secular effects on
the trojan body in both the ERTBP or the RMPP. Our formalism leads to a
decomposition of the Hamiltonian in two parts, $H=H_b+H_{sec}$. $H_b$, called
the basic model, describes resonant dynamics in the short-period (epicyclic)
and synodic (libration) degrees of freedom. $H_{sec}$ contains only terms
depending on slow (secular) angles. $H_b$ is formally identical in the ERTBP
and the RMPP, apart from a re-definition of angular variables. An important
physical consequence is that the slow chaotic diffusion proceeds in both the
ERTBP and the RMPP by a qualitatively similar dynamical mechanism better
approximated by the paradigm of `modulational diffusion'. In the numerical
part, we focus on the ERTBP for making a numerical demonstration of the chaotic
diffusion process along resonances. Using color stability maps, we provide a
survey of the resonant web for characteristic mass parameters of the primary,
in which the secondary resonances from 1:5 to 1:12 (ratio of the short over the
synodic period) and their resonant multiplets appear. We give numerical
examples of diffusion of weakly chaotic orbits in the resonant web. We make a
statistics of the escaping times in the resonant domain, and find power-law
tails of the distribution of escaping times for slowly diffusing chaotic
orbits.",1410.1407v1
2015-06-05,Dynamical coupled-channels model of $K^- p$ reactions (II): Extraction of $Λ^*$ and $Σ^*$ hyperon resonances,"Resonance parameters (pole masses and residues) associated with the excited
states of hyperons, Lambda^* and Sigma^*, are extracted within a dynamical
coupled-channels model developed recently by us [Phys. Rev. C 90, 065204
(2014)] through a comprehensive partial-wave analysis of the K^- p --> barK N,
pi Sigma, pi Lambda, eta Lambda, K Xi data up to invariant mass W = 2.1 GeV. We
confirm the existence of resonances corresponding to most, if not all, of the
four-star resonances rated by the Particle Data Group. We also find several new
resonances, and in particular propose a possible existence of a new narrow
J^P=3/2^+ Lambda resonance that couples strongly to the eta Lambda channel. The
J^P=1/2^- Lambda resonances located below the barK N threshold are also
discussed. Comparing our extracted pole masses with the ones from a recent
analysis by the Kent State University group, some significant differences in
the extracted resonance parameters are found, suggesting the need of more
extensive and accurate data of K^- p reactions including polarization
observables to eliminate such an analysis dependence of the resonance
parameters. In addition, the determined large branching ratios of the decays of
high-mass resonances to the pi Sigma^* and barK^* N channels also suggest the
importance of the data of 2 --> 3 reactions such as K^- p --> pi pi Lambda and
K^- p --> pi barK N. Experiments on measuring cross sections and polarization
observables of these fundamental reactions are highly desirable at hadron beam
facilities such as J-PARC for establishing the Lambda^* and Sigma^* spectrum.",1506.01768v2
2015-07-14,"Strengths of the resonances at 436, 479, 639, 661, and 1279 keV in the $^{22}$Ne(p,$γ$)$^{23}$Na reaction","The $^{22}$Ne(p,$\gamma$)$^{23}$Na reaction is included in the neon-sodium
cycle of hydrogen burning. A number of narrow resonances in the Gamow window
dominates the thermonuclear reaction rate. Several resonance strengths are only
poorly known. As a result, the $^{22}$Ne(p,$\gamma$)$^{23}$Na thermonuclear
reaction rate is the most uncertain rate of the cycle. Here, a new experimental
study of the strengths of the resonances at 436, 479, 639, 661, and 1279 keV
proton beam energy is reported. The data have been obtained using a tantalum
target implanted with $^{22}$Ne. The strengths $\omega\gamma$ of the resonances
at 436, 639, and 661 keV have been determined with a relative approach, using
the 479 and 1279 keV resonances for normalization. Subsequently, the ratio of
resonance strengths of the 479 and 1279 keV resonances was determined,
improving the precision of these two standards. The new data are consistent
with, but more precise than, the literature with the exception of the resonance
at 661 keV, which is found to be less intense by one order of magnitude. In
addition, improved branching ratios have been determined for the gamma decay of
the resonances at 436, 479, and 639 keV.",1507.03893v3
2016-01-13,Resonant slow extraction in synchrotrons by using anti-symmetric sextupole fields,"This paper proposes a novel method for resonant slow extraction in
synchrotrons by using special anti-symmetric sextupole fields, which can be
produced by a special magnet structure. The method has the potential in
applications demanding for very stable slow extraction from synchrotrons. Our
studies show that the slow extraction at the half-integer resonance by using
anti-symmetric sextupole field has some advantages compared to the normal
sextupole field, and the latter is widely used in the slow extraction method.
One of them is that it can work at a more distant tune from the resonance, so
that it can reduce significantly the intensity variation of the extracted beam
which is mainly caused by the ripples of magnet power supplies. The studies by
both the Hamiltonian theory and numerical simulations show that the stable
region at the proximity of the half-integer resonance by anti-symmetric
sextupole field is much smaller and flatter than the one by standard sextupole
field at the third-order resonance. By gradually increasing the field strength,
the beam can be extracted with intensity more homogeneous than by the usual
third-order resonant method, in the means of both smaller intensity variation
and spike in the beginning spill. Similar to the case with a normal sextupole,
we derive an empirical formula for the area of the stable region with an
anti-symmetric sextupole. One can find that with the same field strength and
the same tune distance to the resonance, the area of stable region or the
change of the area due to the working point variation in the case of
anti-symmetric sextupole is about 1/14 of the one in the case of standard
sextupole. The detailed studies including beam dynamic behaviors at the
proximity of other resonances, influence of 2-D field error, half-integer
stop-band, and resonant slow extraction by using quadrupole field have also
been presented.",1601.03113v1
2016-01-15,Photoproduction of $KΛ$ on the proton,"Kaon photoproduction on the proton is studied in the resonance region using
an isobar model. The higher-spin nucleon (3/2 and 5/2) and hyperon (3/2)
resonances were included in the model utilizing the consistent formalism by
Pascalutsa and they were found to play an important role in data description.
The spin-1/2 and spin-3/2 hyperon resonances in combination with the Born terms
contribute significantly to the background part of the amplitude. Various forms
of the hadron form factor were considered in the construction and the dipole
and multidipole forms were selected as those most suitable for the data
description. Model parameters were fitted to new experimental data from CLAS,
LEPS, and GRAAL collaborations and two versions of the model, BS1 and BS2, were
chosen. Both models provide a good overall description of the data for the c.m.
energies from the threshold up to 2.4 GeV. Predicted cross sections of the
models at very small kaon angles being consistent with results of the
Saclay-Lyon model indicate that the models could be also successful in
predicting the hypernucleus production cross sections. Although kaon
photoproduction takes place in the third-resonance region with many resonant
states, the total number of included resonances, 15 and 16, is quite moderate
and it is comparable with numbers of resonances in other models. The set of
chosen nucleon resonances overlaps well with the set of the most probable
contributing states determined in the Bayesian analysis with the
Regge-plus-resonance model. Particularly, we confirm that the missing
resonances $P_{13}(1900)$ and $D_{13}(1875)$ do play important role in the
description of data. However, the spin-1/2 state $P_{11}(1880)$ included in the
Bayesian analysis was replaced in our analysis with the near-mass spin-5/2
state $N^*(1860)$, recently considered by the Particle Data Group.",1601.03840v2
2017-08-06,Comparative analysis of magnetic resonance in the polaron pair recombination and the triplet exciton-polaron quenching models,"We present a comparative theoretical study of magnetic resonance within the
polaron pair recombination (PPR) and the triplet exciton-polaron quenching
(TPQ) models. Both models have been invoked to interpret the photoluminescence
detected magnetic resonance (PLDMR) in $\pi$-conjugated materials. We show that
resonance lineshapes calculated within the two models differ dramatically in
several regards. First, in the PPR model, the lineshape exhibits unusual
behavior upon increasing the microwave power: it evolves from fully positive at
weak power to fully negative at strong power. In contrast, in the TPQ model,
the PLDMR is completely positive, showing a monotonic saturation. Second, the
two models predict different dependencies of the resonance signal on the
photoexcitation power, $P_L$. At low $P_L$, the resonance amplitude $\Delta
I/I$ is $\propto P_L$ in the PPR model, while it is $\propto P_L^2$ crossing
over to $P_L^3$ in the TPQ model. On the physical level, the differences stem
from different underlying spin dynamics. Most prominently, a negative resonance
within the PPR model has its origin in the microwave-induced spin-Dicke effect,
leading to the resonant quenching of photoluminescence. The spin-Dicke effect
results from the spin-selective recombination, resulting in a highly correlated
precession of the on-resonance pair-partners under the strong microwave power.
This effect is not relevant to TPQ, where the majority of triplets are
off-resonance due to the strong zero-field splitting. The analytical evaluation
of lineshapes for the two models is enabled by expressing these shapes via the
eigenvalues of a complex Hamiltonian. This bypasses the necessity of solving
the much larger complex system of stochastic Liouville equations. Our findings
pave the way towards a reliable discrimination between the two mechanisms via
cw PLDMR.",1708.01917v1
2017-12-22,"Resonant scattering due to adatoms in graphene: top, bridge, and hollow position","We present a theoretical study of resonance characteristics in graphene from
adatoms with $s$ or $p_z$ character binding in top, bridge, and hollow
positions. The adatoms are described by two tight-binding parameters: onsite
energy and hybridization strength. We explore a wide range of different
magnitudes of these parameters by employing T-matrix calculations in the single
adatom limit and by tight-binding supercell calculations for dilute adatom
coverage. We calculate the density of states and the momentum relaxation rate
and extract the resonance level and resonance width. Top position with large
hybridization strength or, equivalently, small onsite energy, induces
resonances close to zero energy. Bridge position, compared to top, is more
sensitive to variation in the orbital tight-binding parameters. Resonances
within the experimentally relevant energy window are found mainly for bridge
adatoms with negative onsite energies. The effect of resonances from top and
bridge position on the density of states and momentum relaxation rate is
comparable and both positions give rise to power-law decay of the resonant
state in graphene. Hollow position with $s$ orbital character is affected from
destructive interference which is seen from very narrow resonance peaks in the
density of states and momentum relaxation rate. The resonant state shows no
clear tendency to power-law decay around the impurity and its magnitude
decreases strongly with lowering the adatom content in the supercell
calculations. This is in contrast to top and bridge position. We conclude our
study with a comparison to models of point-like vacancies and strong midgap
scatterers. The latter model gives rise to significantly higher momentum
relaxation rates than caused by single adatoms.",1712.08377v2
2018-01-11,Analyticity of Resonances and Eigenvalues and Spectral Properties of the massless Spin-Boson Model,"We extend the method of multiscale analysis for resonances introduced in [5]
in order to infer analytic properties of resonances and eigenvalues (and their
eigenprojections) as well as estimates for the localization of the spectrum of
dilated Hamiltonians and norm-bounds for the corresponding resolvent operators,
in neighborhoods of resonances and eigenvalues. We apply our method to the
massless Spin-Boson model assuming a slight infrared regularization. We prove
that the resonance and the ground-state eigenvalue (and their eigenprojections)
are analytic with respect to the dilation parameter and the coupling constant.
Moreover, we prove that the spectrum of the dilated Spin-Boson Hamiltonian in
the neighborhood of the resonance and the ground-state eigenvalue is localized
in two cones in the complex plane with vertices at the location of the
resonance and the ground-state eigenvalue, respectively. Additionally, we
provide norm-estimates for the resolvent of the dilated Spin-Boson Hamiltonian
near the resonance and the ground-state eigenvalue. The topic of analyticity of
eigenvalues and resonances has let to several studies and advances in the past.
However, to the best of our knowledge, this is the first time that it is
addressed from the perspective of multiscale analysis. Once the multiscale
analysis is set up our method gives easy access to analyticity: Essentially, it
amounts to proving it for isolated eigenvalues only and use that uniform limits
of analytic functions are analytic. The type of spectral and resolvent
estimates that we prove are needed to control the time evolution including the
scattering regime. The latter will be demonstrated in a forthcoming
publication. The introduced multiscale method to study spectral and resolvent
estimates follows its own inductive scheme and is independent (and different)
from the method we apply to construct resonances.",1801.04021v2
2018-09-13,Modeling the evection resonance for trojan satellites: application to the Saturn system,"The stability of satellites in the solar system is affected by the so-called
evection resonance. The moons of Saturn, in particular, exhibit a complex
dynamical architecture in which co-orbital configurations occur, especially
close to the planet where this resonance is present.
  We address the dynamics of the evection resonance, with particular focus on
the Saturn system, and compare the known behavior of the resonance for a single
moon to that of a pair of moons in co-orbital trojan configuration.
  We developed an analytic expansion of the averaged Hamiltonian of a trojan
pair of bodies, including the perturbation from a distant massive body. {The
analysis of the corresponding equilibrium points was restricted to the
asymmetric apsidal corotation solution of the co-orbital dynamics.} We also
performed numerical N-body simulations to construct dynamical maps of the
stability of the evection resonance in the Saturn system, and to study the
effects of this resonance under the migration of trojan moons caused by tidal
dissipation.
  The structure of the phase space of the evection resonance for trojan
satellites is similar to that of a single satellite, differing in that the
libration centers are displaced from their standard positions by an angle that
depends on the periastron difference $\varpi_2-\varpi_1$ and on the mass ratio
$m_2/m_1$ of the trojan pair.
  The interaction with the inner evection resonance may have been relevant
during the early evolution of the Saturn moons Tethys, Dione, and Rhea. In
particular, Rhea may have had trojan companions in the past that were lost when
it crossed the evection resonance, while Tethys and Dione may either have
retained their trojans or have never crossed the evection. This may help to
constrain the dynamical processes that led to the migration of these satellites
and to the evection itself.",1809.05181v1
2018-09-28,Deep Residual Network for Off-Resonance Artifact Correction with Application to Pediatric Body Magnetic Resonance Angiography with 3D Cones,"Purpose: Off-resonance artifact correction by deep-learning, to facilitate
rapid pediatric body imaging with a scan time efficient 3D cones trajectory.
Methods: A residual convolutional neural network to correct off-resonance
artifacts (Off-ResNet) was trained with a prospective study of 30 pediatric
magnetic resonance angiography exams. Each exam acquired a short-readout scan
(1.18 ms +- 0.38) and a long-readout scan (3.35 ms +- 0.74) at 3T.
Short-readout scans, with longer scan times but negligible off-resonance
blurring, were used as reference images and augmented with additional
off-resonance for supervised training examples. Long-readout scans, with
greater off-resonance artifacts but shorter scan time, were corrected by
autofocus and Off-ResNet and compared to short-readout scans by normalized
root-mean-square error (NRMSE), structural similarity index (SSIM), and peak
signal-to-noise ratio (PSNR). Scans were also compared by scoring on eight
anatomical features by two radiologists, using analysis of variance with
post-hoc Tukey's test. Reader agreement was determined with intraclass
correlation. Results: Long-readout scans were on average 59.3% shorter than
short-readout scans. Images from Off-ResNet had superior NRMSE, SSIM, and PSNR
compared to uncorrected images across +-1kHz off-resonance (P<0.01). The
proposed method had superior NRMSE over -677Hz to +1kHz and superior SSIM and
PSNR over +-1kHz compared to autofocus (P<0.01). Radiologic scoring
demonstrated that long-readout scans corrected with Off-ResNet were
non-inferior to short-readout scans (P<0.01). Conclusion: The proposed method
can correct off-resonance artifacts from rapid long-readout 3D cones scans to a
non-inferior image quality compared to diagnostically standard short-readout
scans.",1810.00072v1
2018-06-03,Search for narrow and broad dijet resonances in proton-proton collisions at $\sqrt{s}=$ 13 TeV and constraints on dark matter mediators and other new particles,"Searches for resonances decaying into pairs of jets are performed using
proton-proton collision data collected at $\sqrt{s} =$ 13 TeV corresponding to
an integrated luminosity of up to 36 fb$^{-1}$. A low-mass search, for
resonances with masses between 0.6 and 1.6 TeV, is performed based on events
with dijets reconstructed at the trigger level from calorimeter information. A
high-mass search, for resonances with masses above 1.6 TeV, is performed using
dijets reconstructed offline with a particle-flow algorithm. The dijet mass
spectrum is well described by a smooth parameterization and no evidence for the
production of new particles is observed. Upper limits at 95% confidence level
are reported on the production cross section for narrow resonances with masses
above 0.6 TeV. In the context of specific models, the limits exclude string
resonances with masses below 7.7 TeV, scalar diquarks below 7.2 TeV, axigluons
and colorons below 6.1 TeV, excited quarks below 6.0 TeV, color-octet scalars
below 3.4 TeV, W' bosons below 3.3 TeV, Z' bosons below 2.7 TeV,
Randall-Sundrum gravitons below 1.8 TeV and in the range 1.9 to 2.5 TeV, and
dark matter mediators below 2.6 TeV. The limits on both vector and axial-vector
mediators, in a simplified model of interactions between quarks and dark matter
particles, are presented as functions of dark matter particle mass and coupling
to quarks. Searches are also presented for broad resonances, including for the
first time spin-1 resonances with intrinsic widths as large as 30% of the
resonance mass. The broad resonance search improves and extends the exclusions
of a dark matter mediator to larger values of its mass and coupling to quarks.",1806.00843v2
2018-08-13,Formation of a planetary Laplace resonance through migration in an eccentric disk - The case of GJ876,"Orbital mean motion resonances in planetary systems originate from
dissipative processes in disk-planet interactions that lead to orbital
migration. In multi-planet systems that host giant planets, the perturbation of
the protoplanetary disk strongly affects the migration of companion planets. By
studying the well-characterized resonant planetary system around GJ 876 we aim
to explore which effects shape disk-driven migration in such a multi-planet
system to form resonant chains. We modelled the orbital migration of three
planets embedded in a protoplanetary disk using two-dimensional locally
isothermal hydrodynamical simulations. We performed a parameter study by
varying the disk thickness, $\alpha$ viscosity, mass as well as the initial
position of the planets. Moreover, we have analysed and compared simulations
with various boundary conditions at the disk's inner rim. We find that due to
the high masses of the giant planets, substantial eccentricity can be excited
in the disk. This results in large variations of the torque acting on the outer
lower-mass planet, which we attribute to a shift of Lindblad and corotation
resonances due to disk eccentricity. Depending on disk parameters, the
migration of the outer planet can be stopped in a non-resonant state. In other
models, the outer planet is able to open a partial gap and to circularize the
disk again, later entering a 2:1 resonance with the most massive planet in the
system to complete the observed Laplace resonance. Disk-mediated interactions
between planets due to spiral waves and excitation of disk eccentricity cause
deviations from smooth inward migration of exterior lower mass planets.
Self-consistent modelling of the disk-driven migration of multi-planet systems
is thus mandatory. Our results are compatible with a late migration of the
outermost planet into the resonant chain, when the giant planet pair already is
in resonance.",1808.04223v1
2019-11-10,Search for high mass dijet resonances with a new background prediction method in proton-proton collisions at $\sqrt{s} =$ 13 TeV,"A search for narrow and broad resonances with masses greater than 1.8 TeV
decaying to a pair of jets is presented. The search uses proton-proton
collision data at $\sqrt{s} =$ 13 TeV collected at the LHC, corresponding to an
integrated luminosity of 137 fb$^{-1}$. The background arising from standard
model processes is predicted with the fit method used in previous publications
and with a new method. The dijet invariant mass spectrum is well described by
both data-driven methods, and no significant evidence for the production of new
particles is observed. Model independent upper limits are reported on the
production cross sections of narrow resonances, and broad resonances with
widths up to 55% of the resonance mass. Limits are presented on the masses of
narrow resonances from various models: string resonances, scalar diquarks,
axigluons, colorons, excited quarks, color-octet scalars, W' and Z' bosons,
Randall-Sundrum gravitons, and dark matter mediators. The limits on narrow
resonances are improved by 200 to 800 GeV relative to those reported in
previous CMS dijet resonance searches. The limits on dark matter mediators are
presented as a function of the resonance mass and width, and on the associated
coupling strength as a function of the mediator mass. These limits exclude at
95% confidence level a dark matter mediator with a mass of 1.8 TeV and width 1%
of its mass or higher, up to one with a mass of 4.8 TeV and a width 45% of its
mass or higher.",1911.03947v2
2022-01-06,Search for high-mass resonances decaying to a jet and a Lorentz-boosted resonance in proton-proton collisions at $\sqrt{s} =$ 13 TeV,"A search is reported for high-mass hadronic resonances that decay to a parton
and a Lorentz-boosted resonance, which in turn decays into a pair of partons.
The search is based on data collected with the CMS detector at the LHC in
proton-proton collisions at $\sqrt{s} =$ 13 TeV, corresponding to an integrated
luminosity of 138 fb$^{-1}$. The boosted resonance is reconstructed as a single
wide jet with substructure consistent with a two-body decay. The high-mass
resonance is thus considered as a dijet system. The jet substructure
information and the kinematic properties of cascade resonance decays are
exploited to disentangle the signal from the large quantum chromodynamics
multijet background. The dijet mass spectrum is analyzed for the presence of
new high-mass resonances, and is found to be consistent with the standard model
background predictions. Results are interpreted in a warped extra dimension
model where the high-mass resonance is a Kaluza-Klein gluon, the boosted
resonance is a radion, and the final state partons are all gluons. Limits on
the production cross section are set as a function of the Kaluza-Klein gluon
and radion masses. These limits exclude at 95% confidence level models with
Kaluza-Klein gluon masses in the range from 2.0 to 4.3 TeV and radion masses in
the range from 0.20 to 0.74 TeV. By exploring a novel experimental signature,
the observed limits on the Kaluza-Klein gluon mass are extended by up to about
1 TeV compared to previous searches.",2201.02140v2
2022-05-10,Modeling transient resonances in extreme-mass-ratio inspirals,"Extreme-mass-ratio inspirals are one of the most exciting and promising
target sources for space-based interferometers (such as LISA, TianQin). The
observation of their emitted gravitational waves will offer stringent tests on
general theory of relativity, and provide a wealth of information about the
dense environment in galactic centers. To unlock such potential, it is
necessary to correctly characterize EMRI signals. However, resonances are a
phenomena that occurs in EMRI systems and can impact parameter inference, and
therefore the science outcome, if not properly modeled. Here, we explore how to
model resonances and develop an efficient implementation. Our previous work has
demonstrated that tidal resonances induced by the tidal field of a nearby
astrophysical object alters the orbital evolution, leading to a significant
dephasing across observable parameter space. Here, we extensively explore a
more generic model for the tidal perturber with additional resonance
combinations, to study the dependence of resonance strength on the intrinsic
orbital and tidal parameters. To analyze the resonant signals, accurate
templates that correctly incorporate the effects of the tidal field are
required. The evolution through resonances is obtained using a step function,
whose amplitude is calculated using an analytic interpolation of the resonance
jumps. We benchmark this procedure by comparing our approximate method to a
numerical evolution. We find that there is no significant error caused by this
simplified prescription, as far as the astronomically reasonable range in the
parameter space is concerned. Further, we use Fisher matrices to study both the
measurement precision of parameters and the systematic bias due to inaccurate
modeling. Modeling of self-force resonances can also be carried out using the
implementation presented in this study, which will be crucial for EMRI waveform
modeling.",2205.04808v1
2022-07-08,Unconventional Collective Resonance as Nonlinear Mechanism of Ectopic Activity in Excitable Media,"Many physical, chemical and biological processes rely on intrinsic
oscillations to employ resonance responses to external stimuli of certain
frequency. Such resonance phenomena in biological systems are typically
explained by one of two mechanisms: either a classical linear resonance of
harmonic oscillator, or entrainment and phase locking of nonlinear limit cycle
oscillators subjected to periodic forcing. Here, we discover a nonlinear
mechanism, which does not require intrinsic oscillations. Instead, the resonant
frequency dependence arises from coupling between an excitable and a monostable
region of the medium. This composite system is endowed with emergent
bistability between a stable steady state and stable spatiotemporal
oscillations. The resonant transition from stable state to oscillatory state is
induced by waves of particular frequency travelling through the medium. This
transition to the spatiotemporal oscillatory state requires accumulation of
multiple waves, resulting in the exclusion of lower frequencies. The cutting
off of high frequencies is realized by damping of wave amplitude in the
monostable zone and then by activating amplitude sensitive dynamics in the
monostable units. We demonstrate this new resonance mechanism in a simplistic
reaction-diffusion model. Also, we reveal this collective resonance mechanism
in in-vitro experiments and detailed biophysical simulations representing a
major type of arrhythmia. We further demonstrate, both experimentally and
theoretically, that the ongoing spatiotemporal oscillations, such as ectopic
activity in cardiac tissue, can be stopped by travelling waves of high
frequency. Overall, we claim the universality of this resonance mechanism in a
broad class of nonlinear biophysical systems. Specifically, we hypothesize that
such phenomena could be found in neuronal systems as an alternative to
traditional resonant processes.",2207.03975v1
2022-11-17,Optimised graded metamaterials for mechanical energy confinement and amplification via reinforcement learning,"A reinforcement learning approach to design optimised graded metamaterials
for mechanical energy confinement and amplification is described. Through the
proximal policy optimisation algorithm, the reinforcement agent is trained to
optimally set the lengths and the spacing of an array of resonators. The design
optimisation problem is formalised in a Markov decision problem by splitting
the optimisation procedure into a discrete number of decisions. Being the
physics of graded metamaterials governed by the spatial distribution of local
resonances, the space of possible configurations is constrained by using a
continuous function for the resonators arrangement. A preliminary analytical
investigation has been performed to characterise the dispersive properties of
the analysed system by treating it as a locally resonant system. The outcomes
of the optimisation procedure confirms the results of previous investigations,
highlighting both the validity of the proposed approach and the robustness of
the systems of graded resonators when employed for mechanical energy
confinement and amplification. The role of the resonator spacing is shown to be
secondary with respect to the resonator lengths or, in other words, with
respect to the oscillation frequencies of the resonators. However, it is also
demonstrated that reducing the number of resonators can be advantageous. The
outcomes related to the joint optimisation of the resonator lengths and
spacing, thanks also to the adaptive control of the analysis duration, overcome
significantly the performance of previously known systems by working almost
uniquely on enlarging the time in which the harvester oscillations take place
without amplifying these oscillations. The proposed procedure is suitable to be
applied to a wide range of design optimisation problems in which the effect of
the design choices can be assessed through numerical simulations.",2211.09528v2
2022-12-09,Measurement-Induced State Transitions in a Superconducting Qubit: Within the Rotating Wave Approximation,"Superconducting qubits typically use a dispersive readout scheme, where a
resonator is coupled to a qubit such that its frequency is qubit-state
dependent. Measurement is performed by driving the resonator, where the
transmitted resonator field yields information about the resonator frequency
and thus the qubit state. Ideally, we could use arbitrarily strong resonator
drives to achieve a target signal-to-noise ratio in the shortest possible time.
However, experiments have shown that when the average resonator photon number
exceeds a certain threshold, the qubit is excited out of its computational
subspace in a process we refer to as a measurement-induced state transition
(MIST). These transitions degrade readout fidelity, and constitute leakage
which precludes further operation of the qubit in, for example, error
correction. Here we study these transitions experimentally with a transmon
qubit by measuring their dependence on qubit frequency, average resonator
photon number, and qubit state, in the regime where the resonator frequency is
lower than the qubit frequency. We observe signatures of resonant transitions
between levels in the coupled qubit-resonator system that exhibit noisy
behavior when measured repeatedly in time. We provide a semi-classical model of
these transitions based on the rotating wave approximation and use it to
predict the onset of state transitions in our experiments. Our results suggest
the transmon is excited to levels near the top of its cosine potential
following a state transition, where the charge dispersion of higher transmon
levels explains the observed noisy behavior of state transitions. Moreover, we
show that occupation in these higher energy levels poses a major challenge for
fast qubit reset.",2212.05097v2
2022-12-31,Four-body Semileptonic Charm Decays $D\to P_1P_2\ell^+ν_\ell $ Based on SU(3) Flavor Analysis,"Motivated by the significant experimental progress in probing semileptonic
decays $D\to P_1P_2\ell^+\nu_\ell~(\ell=\mu,e)$, we analyze the branching
ratios of the $D\to P_1P_2\ell^+\nu_\ell $ decays with the non-resonant, the
light scalar meson resonant and the vector meson resonant contributions in this
work. We obtain the hadronic amplitude relations between different decay modes
by the SU(3) flavor analysis, and then predict relevant branching ratios of the
$D\to P_1P_2\ell^+\nu_\ell$ decays by the present experimental data with $2
\sigma$ errors. Most of our predicted branching ratios are consistent with
present experimental data within $2\sigma$ error bars, and others are
consistent with the data within $3\sigma$ error bars. We find that some
branching ratios of the non-resonant decays are on the order of
$\mathcal{O}(10^{-3}-10^{-4})$, the vector meson resonant contributions are
dominant in many decays, the non-resonant, the vector meson resonant and the
scalar resonant contributions are all important in the
$D^0\to\eta\pi^-\ell^+\nu_\ell$ decays, and both the non-resonant and the
scalar resonant contributions are important in the $D^0\to
K^-K^0\ell^+\nu_\ell,\eta'\pi^-\ell^+\nu_\ell$ and $D^+\to
\overline{K}^0K^0\ell^+\nu_\ell,\pi^0\pi^0\ell^+\nu_\ell,\eta\pi^0\ell^+\nu_\ell,\eta'\pi^0\ell^+\nu_\ell$
decays. According to our predictions, many decay modes could be observed in the
experiments like BESIII, LHCb and BelleII, and some decay modes might be
measured in these experiments in near future.",2301.00090v2
2023-01-13,"Second sound resonators and tweezers as vorticity or velocity probes : fabrication, model and method","An analytical model of open-cavity second sound resonators is presented and
validated against simulations and experiments in superfluid helium using a new
resonator design that achieves unprecedented resolution. The model incorporates
diffraction, geometrical misalignments, and flow through the cavity, and is
validated using cavities with aspect ratios close to unity, operated up to
their 20th resonance in superfluid helium.An important finding of this study is
that resonators can be optimized to selectively sense either the quantum vortex
density carried by the throughflow -- as typically done in the literature -- or
the mean velocity of the throughflow. We propose two velocity probing methods:
one that takes advantage of geometrical misalignments between the tweezers
plates, and another that drives the resonator non-linearly, beyond a threshold
that results in the self-sustainment of a vortex tangle within the cavity.A new
mathematical treatment of the resonant signal is proposed to adequately filter
out parasitic signals, such as temperature and pressure drift, and accurately
separate the quantum vorticity signal. This elliptic method consists in a
geometrical projection of the resonance in the inverse complex plane. Its
effectiveness is demonstrated over a wide range of operating conditions.The
resonator model and elliptic method are being utilized to characterize a new
design of second-sound resonator with high resolution thanks to miniaturization
and design optimization. These second-sound tweezers are capable of providing
time-space resolved information similar to classical local probes in
turbulence, down to sub-millimeter and sub-millisecond scales. The principle,
design, and micro-fabrication of second sound tweezers are being presented in
detail, along with their potential for exploring quantum turbulence.",2301.05519v2
2023-03-20,Enhanced Blackhole mergers in AGN discs due to Precession induced resonances,"Recent studies have shown that AGN discs can host sources of gravitational
waves. Compact binaries can form and merge in AGN discs through their
interactions with the gas and other compact objects in the disc. It is also
possible for the binaries to shorten the merging timescale due to eccentricity
excitation caused by perturbations from the supermassive blackhole (SMBH). In
this paper we focus on effects due to precession-induced (eviction-like)
resonances, where nodal and apsidal precession rates of the binary is
commensurable with the mean motion of the binary around the SMBH. We focus on
intermediate mass black hole (IMBH)-stellar mass black hole (SBH) binaries, and
consider binary orbit inclined from the circum-IMBH disk which leads to the
orbital $J_2$ precession. We show that if a binary is captured in these
resonances and is migrating towards the companion, it can undergo large
eccentricity and inclination variations. We derive analytical expressions for
the location of fixed points, libration timescale and width for these
resonances, and identified two resonances in the near coplanar regime (the
evection and eviction resonances) as well as two resonances in the near polar
regime that can lead to mergers. We also derive analytical expressions for the
maximum eccentricity that a migrating binary can achieve for given initial
conditions. Specifically, the maximum eccentricity can reach 0.9 when captured
in these resonances before orbital decay due to gravitational wave emission
dominates, and the capture is only possible for slow migration ($\sim 10$ Myr)
2-3 order of magnitude longer than the resonance libration timescale. We also
show that capture into multiple resonances is possible, and can further excite
eccentricities.",2303.12539v2
2023-04-08,On the possibility of testing the two-peak structure of the LHCb hidden-charm strange pentaquark $P_{cs}(4459)^0$ in near-threshold antikaon-induced charmonium production on protons and nuclei,"Accounting for the LHCb observation that the reported hidden-charm strange
pentaquark $P_{cs}(4459)^0$ can split into two substructures, $P_{cs}(4455)^0$
and $P_{cs}(4468)^0$, with a mass difference of 13 MeV as well as the newly
observed hidden-charm pentaquark resonance $P_{cs}(4338)^0$ with strangeness,
we study within the double-peak scenario for the $P_{cs}(4459)^0$ state the
near-threshold $J/\psi$ meson production from protons and nuclei by considering
incoherent direct non-resonant (${K^-}p \to {J/\psi}\Lambda$) and two-step
resonant (${K^-}p \to P_{csi}^0 \to {J/\psi}\Lambda$, $i=1$, 2, 3;
$P_{cs1}^{0}=P_{cs}(4338)^0$, $P_{cs2}^{0}=P_{cs}(4455)^0$,
$P_{cs3}^{0}=P_{cs}(4468)^0$) charmonium production processes with the main
goal of clarifying the possibility to observe within this scenario both above
two substructures contributing to the $P_{cs}(4459)^0$ state and the
$P_{cs}(4338)^0$ resonance in this production. We calculate the absolute
excitation functions, energy and momentum distributions for the non-resonant,
resonant and for the combined (non-resonant plus resonant) production of
$J/\psi$ mesons on protons as well as on carbon and tungsten target nuclei at
near-threshold incident antikaon beam momenta by assuming the spin-parity
assignments of the hidden-charm resonances $P_{cs}(4338)^0$, $P_{cs}(4455)^0$
and $P_{cs}(4468)^0$ as $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within
four different realistic choices for the branching ratios of their decays to
the ${J/\psi}\Lambda$ mode (0.125, 0.25, 0.5 and 1\%) as well as for two
options for the branching fraction of their decays to the $K^-p$ channel (0.01
and 0.001\%). We show that these combined observables reveal clear sensitivity
to these scenarios. Hence, they may be an important tool to provide further
evidence for the existence of the above strange hidden-charm pentaquark
resonances.",2304.03978v2
2023-06-27,Measurement Accuracy in Silicon Photonic Ring Resonator Thermometers: Identifying and Mitigating Intrinsic Impairments,"Silicon photonic ring resonator thermometers have been shown to provide
temperature measurements with a 10 mK accuracy. In this work we identify and
quantify the intrinsic on-chip impairments that may limit further improvement
in temperature measurement accuracy. The impairments arise from optically
induced changes in the waveguide effective index, and from back-reflections and
scattering at defects and interfaces inside the ring cavity and along the path
between light source and detector. These impairments are characterized for 220
x 500 nm Si waveguide rings by experimental measurement in a calibrated
temperature bath and by phenomenological models of ring response. At different
optical power levels both positive and negative light induced resonance shifts
are observed. For a ring with L = 100 um cavity length, the self-heating
induced resonance red shift can alter the temperature reading by 200 mK at 1 mW
incident power, while a small blue shift is observed below 100 uW. The effect
of self-heating is shown to be effectively suppressed by choosing longer ring
cavities. Scattering and back-reflections often produce split and distorted
resonance line shapes. Although these distortions can vary with resonance
order, they are almost completely invariant with temperature for a given
resonance and do not lead to measurement errors in themselves. The effect of
line shape distortions can largely be mitigated by tracking only selected
resonance orders with negligible shape distortion, and by measuring the
resonance minimum wavelength directly, rather than attempting to fit the entire
resonance line shape. The results demonstrate the temperature error due to
these impairments can be limited to below the 3 mK level through appropriate
design choices and measurement procedures.",2306.15643v1
2023-08-15,Tidal interactions shape period ratios in planetary systems with three-body resonant chains,"These last years several Systems with Tightly packed Inner Planets in the
super-Earth mass regime have been discovered harboring chains of resonances. It
is generally believed that planet pairs get trapped in MMR during the migration
phase in the protoplanetary disk, while the tides raised by the host star
provide a source of dissipation on very long timescales. In this work, we aim
to study the departure from exact commensurabilities observed among the STIPs
which harbor 3-planet resonances and analyze how tides play an important role
in shaping the resonance offsets for the STIPs. We analyzed the resonance
offsets between adjacent pairs for five multi-planetary systems, namely
Kepler-80, Kepler-223, K2-138, TOI-178, and TRAPPIST-1, highlighting the
existence of different trends in the offsets. On the one hand, we derived
analytical estimates for the offsets, which confirm that the departure of the
planetary pairs from the nominal MMRs are due to the 3-planet resonant
dynamics. On the other hand, we performed N-body simulations including both
orbital migration and tidal dissipation from the host star with simple
prescriptions in order to test the effectiveness of this mechanism at shaping
the observed trend in the offsets, focusing our study on the preservation of
the resonant patterns in the different systems with the same general setup. We
found that the trends in the offsets of the five detected systems can be
produced by tidal damping effects, regardless of the considered value for the
tidal factor. It is a robust mechanism that relaxes the system towards
equilibrium while efficiently moving it along 3-planet resonances, which
induces the observed resonance offset for each planet pair. In addition, we
showed that for Kepler-80, K2-138, and TOI-178, the amplitudes of the resonant
offsets can also be reproduced with appropriate tidal factor, for the estimated
age of the systems.",2308.07839v1
2024-02-01,Can Neptune's Distant Mean-Motion Resonances Constrain Undiscovered Planets in the Solar System? Lessons from a Case Study of the 9:1,"Recent observational surveys of the outer Solar System provide evidence that
Neptune's distant $n$:1 mean-motion resonances may harbor relatively large
reservoirs of trans-Neptunian objects (TNOs). In particular, the discovery of
two securely classified 9:1 resonators, 2015 KE$_{172}$ and 2007 TC$_{434}$, by
the Outer Solar System Origins Survey is consistent with a population of order
$10^4$ such objects in the 9:1 resonance with absolute magnitude $H_r < 8.66$.
This work investigates whether the long-term stability of such populations in
Neptune's $n$:1 resonances can be used to constrain the existence of distant
$5-10M_{\oplus}$ planets orbiting at hundreds of AU. The existence of such a
planet has been proposed to explain a reported clustering in the orbits of
highly eccentric ""extreme"" trans-Neptunian objects (eTNOs), although this
hypothesis remains controversial. We engage in a focused computational
case-study of the 9:1 resonance, generating synthetic populations and
integrating them for 1 Gyr in the presence of 81 different test planets with
various masses, perihelion distances, eccentricities, and inclinations. While
none of the tested planets are incompatible with the existence of 9:1
resonators, our integrations shed light on the character of the interaction
between such planets and nearby $n$:1 resonances, and we use this knowledge to
construct a simple, heuristic method for determining whether or not a given
planet could destabilize a given resonant population. We apply this method to
the currently estimated properties of Planet 9, and find that a large
primordial population in the 15:1 resonance (or beyond), if discovered in the
future, could potentially constrain the existence of this planet.",2402.00266v1
2019-12-06,Ruelle-Pollicott Resonances of Stochastic Systems in Reduced State Space. Part I: Theory,"A theory of Ruelle-Pollicott (RP) resonances for stochastic differential
systems is presented. These resonances are defined as the eigenvalues of the
generator (Kolmogorov operator) of a given stochastic system. By relying on the
theory of Markov semigroups, decomposition formulas of correlation functions
and power spectral densities (PSDs) in terms of RP resonances are then derived.
These formulas describe, for a broad class of stochastic differential equations
(SDEs), how the RP resonances characterize the decay of correlations as well as
the signal's oscillatory components manifested by peaks in the PSD.It is then
shown that a notion reduced RP resonances can be rigorously defined, as soon as
the dynamics is partially observed within a reduced state space V . These
reduced resonances are obtained from the spectral elements of reduced Markov
operators acting on functions of the state space V , and can be estimated from
series. They inform us about the spectral elements of some coarse-grained
version of the SDE generator. When the time-lag at which the transitions are
collected from partial observations in V , is either sufficiently small or
large, it is shown that the reduced RP resonances approximate the (weak) RP
resonances of the generator of the conditional expectation in V , i.e. the
optimal reduced system in V obtained by averaging out the contribution of the
unobserved variables. The approach is illustrated on a stochastic slow-fast
system for which it is shown that the reduced RP resonances allow for a good
reconstruction of the correlation functions and PSDs, even when the time-scale
separation is weak.The companions articles, Part II and Part III, deal with
further practical aspects of the theory presented in this contribution. One
important byproduct consists of the diagnosis usefulness of stochastic dynamics
that RP resonances provide. This is illustrated in the case of a stochastic
Hopf bifurcation in Part II. There, it is shown that such a bifurcation has a
clear manifestation in terms of a geometric organization of the RP resonances
along discrete parabolas in the left half plane. Such geometric features formed
by (reduced) RP resonances are extractable from time series and allow thus for
providing an unambiguous ""signature"" of nonlinear oscillations embedded within
a stochastic background. By relying then on the theory of reduced RP resonances
presented in this contribution, Part III addresses the question of detection
and characterization of such oscillations in a high-dimensional stochastic
system, namely the Cane-Zebiak model of El Ni{\~n}o-Southern Oscillation
subject to noise modeling fast atmospheric fluctuations.",1912.03170v2
1995-04-11,THE ORIGIN OF PLUTO'S ORBIT: IMPLICATIONS FOR THE SOLAR SYSTEM BEYOND NEPTUNE,"The origin of the highly eccentric, inclined, and resonance-locked orbit of
Pluto has long been a puzzle. A possible explanation has been proposed recently
[Malhotra, R., {\it Nature} 365:819-21 (1993)] which suggests that these
extraordinary orbital properties may be a natural consequence of the formation
and early dynamical evolution of the outer Solar system. A resonance capture
mechanism is possible during the clearing of the residual planetesimal debris
and the formation of the Oort Cloud of comets by planetesimal mass loss from
the vicinity of the giant planets. If this mechanism were in operation during
the early history of the planetary system, the entire region between the orbit
of Neptune and approximately 50 AU would have been swept by first order mean
motion resonances. Thus, resonance capture could occur not only for Pluto, but
quite generally for other trans-Neptunian small bodies. Some consequences of
this evolution for the present-day dynamical structure of the trans-Neptunian
region are: (i) most of the objects in the region beyond Neptune and up to
$\sim\!50$ AU exist in very narrow zones located at orbital resonances with
Neptune (particularly the 3:2 and the 2:1 resonances), and (ii) these resonant
objects would have significantly large eccentricities. The distribution of
objects in the Kuiper Belt as predicted by this theory is presented here.
Keywords{solar system: origins, dynamics --- Pluto --- comets --- Kuiper Belt}",9504036v1
1999-09-03,Tidal evolution of eccentric orbits in massive binary systems; a study of resonance locking,"We study the tidal evolution of a binary system consisting of a 1.4 Msun
compact object in elliptic orbit about a 10 Msun uniformly rotating main
sequence star for various values of the initial orbital parameters. We apply
our previously published results of 2D non-adiabatic calculations of the
non-radial g- and r-mode oscillations of the uniformly rotating MS star, and
include the effects of resonant excitation of these modes in the tidal
evolution calculations. A high orbital eccentricity enhances the effectiveness
of the tidal interaction because of the large number of harmonic components of
the tidal potential and the reduced orbital separation near periastron. By
including the evolution of the MS star, especially of its rotation rate, many
resonance crossings occur with enhanced tidal interaction. We analyse the
phenomenon of resonance locking whereby a particular tidal harmonic is kept
resonant with a stellar oscillation mode. Resonance locking of prograde g-modes
appears an effective mechanism for orbital circularization of eccentric orbits.
We consider the orbital evolution of the binary pulsar PSR J0045-7319 and
conclude that resonance locking could explain the observed short orbital decay
time of this system if the B-star spins in the direction counter to the orbital
motion.",9909073v1
2000-09-15,Resonant capture by inward migrating planets,"We investigate resonant capture of small bodies by planets that migrate
inwards, using analytic arguments and three-body integrations. If the orbits of
the planet and the small body are initially circular and coplanar, the small
body is captured when it crosses the 2:1 resonance with the planet. As the
orbit shrinks it becomes more eccentric, until by the time its semimajor axis
has shrunk by a factor of four, its eccentricity reaches nearly unity
(1-e<<10^{-4}). In typical planetary systems, bodies in this high-eccentricity
phase are likely to be consumed by the central star. If they can avoid this
fate, as migration continues the inclination flips from 0 to i=180 degrees;
thereafter the eccentricity declines until the semimajor axis is a factor of
nine smaller than at capture, at which point the small body is released from
the 2:1 resonance on a nearly circular retrograde orbit. Small bodies captured
into resonance from initially inclined or eccentric orbits can also be ejected
from the system, or released from the resonance on highly eccentric polar
orbits (i\simeq 90 degrees) that are stabilized by a secular resonance. We
conclude that migration can drive much of the inner planetesimal disk into the
star, and that post-migration multi-planet systems may not be coplanar.",0009255v1
2001-02-06,"K-shell dielectronic resonances in photoabsorption: differential oscillator strengths for Li-like C IV, O VI, and Fe XXIV","Recently X-ray photoabsorption in KLL resonances of O VI was predicted
[Pradhan, Astrophys.J. Lett. 545, L165 (2000)], and detected by the Chandra
X-ray Observatory [Lee et al, Astrophys. J. {\it Lett.}, submitted].
  The required resonance oscillator strengths f_r, are evaluated in terms of
the differential oscillator strength df/de that relates bound and continuum
absorption. We present the f_r values from radiatively damped and undamped
photoionization cross sections for Li-like C,O, and Fe calculated using
relativistic close coupling Breit-Pauli R-matrix method. The KLL resonances of
interest here are: 1s2p (^3P^o) 2s [^4P^o_{1/2,3/2}, ^2P^o_{1/2,3/2}] and 1s2p
(^1P^o) 2s [^2P^o_{1/2,3/2}]. The KLL photoabsorption resonances in Fe XXIV are
fully resolved up to natural autoionization profiles for the first time. It is
demonstrated that the undamped f_r independently yield the resonance radiative
decay rates, and thereby provide a precise check on the resolution of
photoionization calculations in general. The predicted photoabsorption features
should be detectable by the X-ray space observatories and enable column
densities in highly ionized astrophysical plasmas to be determined from the
calculated f_r. The dielectronic satellites may appear as redward broadening of
resonances lines in emission and absorption.",0102107v2
2003-06-16,Are stellar coronae optically thin in X-rays? - A systematic investigation of opacity effects,"The relevance of resonant scattering (absorption by photo-excitation and
re-emission out of the line of sight) in the solar corona has always been
discussed controversially. Ratios of emission lines from identical ions but
different oscillator strengths are tracers for damping of resonance lines due
to possible resonant scattering. We present an analysis of a large sample of 44
stellar spectra obtained with all gratings on board Chandra and XMM-Newton and
systematically measure line ratios of FeXVII lines at 15.27A and 16.78A lines
to the resonance line at 15.03A as well as the He-like f/r ratio of OVII and
NeIX. The same ratios obtained from optically thin plasma atomic databases such
as MEKAL, Chianti, and APEC are found to be discrepant, however, we find no
convincing proof for resonance line scattering. Optical depths are basically
identical for all kinds of stellar coronae and we conclude that identical
optical depths are more probable when effects from resonant scattering are
generally negligible. The 15.27/15.03A ratio shows a regular trend suggesting
blending of the 15.27A line by a cooler Fe line, possibly FeXVI. The He-like
f/r ratios for O and Ne show no indication for significant damping of the
resonance lines. We mainly attribute deviations from the atomic databases to
still uncertain emissivities which do not agree well with laboratory
measurements and which come out with differing results when accounting for one
or the other side effect.",0306308v1
2003-06-20,Enhancement of the helium resonance lines in the solar atmosphere by suprathermal electron excitation II: non-Maxwellian electron distributions,"In solar EUV spectra the He I and He II resonance lines show unusual
behaviour and have anomalously high intensities compared with other transition
region lines. The formation of the helium resonance lines is investigated
through extensive non-LTE radiative transfer calculations. The model
atmospheres of Vernazza, Avrett & Loeser are found to provide reasonable
matches to the helium resonance line intensities but significantly
over-estimate the intensities of other transition region lines. New model
atmospheres have been developed from emission measure distributions derived by
Macpherson & Jordan, which are consistent with SOHO observations of transition
region lines other than those of helium. These models fail to reproduce the
observed helium resonance line intensities by significant factors. The
possibility that non-Maxwellian electron distributions in the transition region
might lead to increased collisional excitation rates in the helium lines is
studied. Collisional excitation and ionization rates are re-computed for
distribution functions with power law suprathermal tails which may form by the
transport of fast electrons from high temperature regions. Enhancements of the
helium resonance line intensities are found, but many of the predictions of the
models regarding line ratios are inconsistent with observations. These results
suggest that any such departures from Maxwellian electron distributions are not
responsible for the helium resonance line intensities.",0306410v1
2005-07-22,Resonant Cyclotron Scattering and Comptonization in Neutron Star Magnetospheres,"Resonant cyclotron scattering of the surface radiation in the magnetospheres
of neutron stars may considerably modify the emergent spectra and impede
efforts to constraint neutron star properties. Resonant cyclotron scattering by
a non-relativistic warm plasma in an inhomogeneous magnetic field has a number
of unusual characteristics: (i) in the limit of high resonant optical depth,
the cyclotron resonant layer is half opaque, in sharp contrast to the case of
non-resonant scattering. (ii) The transmitted flux is on average Compton
up-scattered by ~ $1+ 2 beta_T$, where $\beta_T$ is the typical thermal
velocity in units of the velocity of light; the reflected flux has on average
the initial frequency. (iii) For both the transmitted and reflected fluxes the
dispersion of intensity decreases with increasing optical depth. (iv) The
emergent spectrum is appreciably non-Plankian while narrow spectral features
produced at the surface may be erased.
  We derive semi-analytically modification of the surface Plankian emission due
to multiple scattering between the resonant layers and apply the model to
anomalous X-ray pulsar 1E 1048.1--5937. Our simple model fits just as well as
the ``canonical'' magnetar spectra model of a blackbody plus power-law.",0507557v2
2005-09-22,Forced oscillations in a hydrodynamical accretion disk and QPOs,"This is the second of a series of papers aimed to look for an explanation on
the generation of high frequency quasi-periodic oscillations (QPOs) in
accretion disks around neutron star, black hole, and white dwarf binaries. The
model is inspired by the general idea of a resonance mechanism in the accretion
disk oscillations as was already pointed out by Abramowicz & Klu{\'z}niak
(\cite{Abramowicz2001}). In a first paper (P\'etri \cite{Petri2005a}, paper I),
we showed that a rotating misaligned magnetic field of a neutron star gives
rise to some resonances close to the inner edge of the accretion disk. In this
second paper, we suggest that this process does also exist for an asymmetry in
the gravitational potential of the compact object. We prove that the same
physics applies, at least in the linear stage of the response to the
disturbance in the system. This kind of asymmetry is well suited for neutron
stars or white dwarfs possessing an inhomogeneous interior allowing for a
deviation from a perfectly spherically symmetric gravitational field. We show
by a linear analysis that the disk initially in a cylindrically symmetric
stationary state is subject to three kinds of resonances: a corotation
resonance, a Lindblad resonance due to a driven force and a parametric sonance.
The highest kHz QPOs are then interpreted as the orbital frequency of the disk
at locations where the response to the resonances are maximal. It is also found
that strong gravity is not required to excite the resonances.",0509668v1
2006-01-03,Twin-peak quasiperiodic oscillations as an internal resonance,"Two inter-related peaks occur in high-frequency power spectra of X-ray
lightcurves of several black-hole candidates. We further explore the idea that
a non-linear resonance mechanism, operating in strong-gravity regime, is
responsible for these quasi-periodic oscillations (QPOs). By extending the
multiple-scales analysis of Rebusco, we construct two-dimensional phase-space
sections, which enable us to identify different topologies governing the system
and to follow evolutionary tracks of the twin peaks. This suggests that the
original (Abramowicz and Kluzniak) parametric-resonance scheme can be viewed as
an ingenuous account of the QPOs model with an internal resonance. We show an
example of internal resonance in a system with up to two critical points, and
we describe a general technique that permits to treat other cases in a
systematical manner. A separatrix divides the phase-space sections into regions
of different topology: inside the libration region the evolutionary tracks
bring the observed twin-peak frequencies to an exact rational ratio, whereas in
the circulation region the observed frequencies remain off resonance. Our
scheme predicts the power should cyclically be exchanged between the two
oscillations. Likewise the high-frequency QPOs in neutron-star binaries, also
in black-hole sources one expects, as a general property of the non-linear
model, that slight detuning pushes the twin-peak frequencies out of sharp
resonance.",0601053v1
2006-07-10,Brownian Motion in Planetary Migration,"A residual planetesimal disk of mass 10-100 Earth masses remained in the
outer solar system following the birth of the giant planets, as implied by the
existence of the Oort cloud, coagulation requirements for Pluto, and
inefficiencies in planet formation. Upon gravitationally scattering
planetesimal debris, planets migrate. Orbital migration can lead to resonance
capture, as evidenced here in the Kuiper and asteroid belts, and abroad in
extra-solar systems. Finite sizes of planetesimals render migration stochastic
(""noisy""). At fixed disk mass, larger (fewer) planetesimals generate more
noise. Extreme noise defeats resonance capture. We employ order-of-magnitude
physics to construct an analytic theory for how a planet's orbital semi-major
axis fluctuates in response to random planetesimal scatterings. To retain a
body in resonance, the planet's semi-major axis must not random walk a distance
greater than the resonant libration width. We translate this criterion into an
analytic formula for the retention efficiency of the resonance as a function of
system parameters, including planetesimal size. We verify our results with
tailored numerical simulations. Application of our theory reveals that capture
of Resonant Kuiper belt objects by a migrating Neptune remains effective if the
bulk of the primordial disk was locked in bodies having sizes < O(100) km and
if the fraction of disk mass in objects with sizes > 1000 km was less than a
few percent. Coagulation simulations produce a size distribution of primordial
planetesimals that easily satisfies these constraints. We conclude that
stochasticity did not interfere with, nor modify in any substantive way,
Neptune's ability to capture and retain Resonant Kuiper belt objects during its
migration.",0607203v1
1996-08-20,Dielectric resonances of lattice animals and other fractal structures,"Electrical and optical properties of binary inhomogeneous media are currently
modelled by a random network of metallic bonds (conductance $\sigma_0$,
concentration $p$) and dielectric bonds (conductance $\sigma_1$, concentration
$1-p$). The macroscopic conductivity of this model is analytic in the complex
plane of the dimensionless ratio $h=\sigma_1/\sigma_0$ of the conductances of
both phases, cut along the negative real axis. This cut originates in the
accumulation of the resonances of clusters with any size and shape. We
demonstrate that the dielectric response of an isolated cluster, or a finite
set of clusters, is characterised by a finite spectrum of resonances, occurring
at well-defined negative real values of $h$, and we define the cross-section
which gives a measure of the strength of each resonance. These resonances show
up as narrow peaks with Lorentzian line shapes, e.g. in the weak-dissipation
regime of the $RL-C$ model. The resonance frequencies and the corresponding
cross-sections only depend on the underlying lattice, on the geometry of the
clusters, and on their relative positions. Our approach allows an exact
determination of these characteristics. It is applied to several examples of
clusters drawn on the square lattice. Scaling laws are derived analytically,
and checked numerically, for the resonance spectra of linear clusters, of
lattice animals, and of several examples of self-similar fractals.",9608079v1
2002-12-10,"Coherent Random Lasing and ""Almost Localized"" Photon Modes","A pulse of light, injected into a weakly disordered dielectric medium,
typically, will leave its initial location in a short time, by diffusion.
However, due to some rare configurations of disorder, there is a possibility of
formation of high quality resonators which can trap light for a long time. We
present a rather detailed, quantitative study of such random resonators and of
the ""almost localized"" states that they can support. After presenting a brief
review of the earlier work on the subject, we concentrate on a detailed
computation of the ""prefactor"": knowledge of the latter is crucial for
varifying the viability of the random rasonators and their areal density. Both
short range disorder (white noise) and correlated disorder are studied, and the
important effect of the correlation radius, $R_c$, on the probability of
formation of resonators with a given quality factor $Q$ is discussed. The
random resonators are ""self-formed"", in the sense that no sharp features (like
Mie scatterers or other ""resonant entities"") are introduced: our model is a
featureless dielectric medium with fluctuating dielectric constant. We point
out the relevance of the random resonators to the recently discovered
phenomenon of coherent ""random"" lasing and review the existing work on that
subject. We emphasize, however, that the random resonators exist already in the
{\em passive} medium: gain is only needed to ""make them visible"".",0212231v2
2003-08-08,Dynamic Stripes and Resonance in the Superconducting and Normal Phases of YBa2Cu3O6.5 Ortho-II Superconductor,"We describe the relation between spin fluctuations and superconductivity in a
highly-ordered sample of YBaCu3O6.5 using both polarized and unpolarized
neutron inelastic scattering. The spin susceptibility in the superconducting
phase exhibits one-dimensional incommensurate modulations at low-energies,
consistent with hydrodynamic stripes. With increasing energy the susceptibility
curves upward to a commensurate, intense, well-defined and asymmetric resonance
at 33 meV with a precipitous high-energy cutoff. In the normal phase, which we
show is gapless, the resonance remains surprisingly strong and persists clearly
in Q scans and energy scans. Its similar asymmetric spectral form above Tc=59 K
suggests that incoherent superconducting pairing fluctuations are present in
the normal state. On cooling, the resonance and the stripe modulations grow in
well above Tc below a temperature that is comparable to the pseudogap
temperature where suppression occurs in local and low-momentum properties. The
spectral weight that accrues to the resonance is largely acquired by transfer
from suppressed low-energy fluctuations. We find the resonance to be
isotropically polarized, consistent with a triplet carrying ~2.6% of the total
spectral weight of the Cu spins in the planes.",0308168v2
2004-02-18,Interface-Localized Mode In Bilayer Film Ferromagnetic Resonance Spectrum,"Ferromagnetic resonance (FMR) in exchange-coupled bilayer films has been the
subject of intensive studies in recent years. From the experimental viewpoint,
a characteristic feature of this FMR is that some specimens show single
resonance, whereas others show double resonance. Moreover, double resonance can
exhibit a regular pattern, in which the high-field (HF) line intensity
surpasses that of the low-field (LF) line, or it can exhibit an inverted
pattern with the HF line less intense than the LF line. There is a general
belief that the inverted FMR pattern occurs when the HF line is an ""optic
mode"", i.e. an out-of-phase composition of individual sublayer modes, and the
LF line is an ""acoustic mode"", or an in-phase mode composition. The existing
theoretical explanations of bilayer ferromagnetic resonance are, as a rule,
based on phenomenological equation of motion of the magnetization vector. In
this paper, we propose a theory of FMR in ultrathin bilayers based on an
entirely microscopic approach, using the Heisenberg model of localized spins
and assuming that the two ferromagnetic sublayers are exchange-coupled through
their interface. This rigorous microscopic FMR theory does explain the inverted
pattern of the bilayer FMR spectrum by assuming the HF line to correspond to an
in-phase mode, but of interface-localized nature; this gives a possibility to
explore the HF resonance line corresponding to the interface-localized mode as
a potential source of information concerning the bilayer interface.",0402475v1
2004-08-18,"Electronic Raman scattering in correlated materials: exact treatment of nonresonant, mixed, and resonant scattering with dynamical mean field theory","We solve for the electronic Raman scattering response functions on an
infinite-dimensional hypercubic lattice employing dynamical mean field theory.
This contribution extends previous work on the nonresonant response to include
the mixed and resonant contributions. We focus our attention on the spinless
Falicov-Kimball model, where the problem can be solved exactly, and the system
can be tuned to go through a Mott-Hubbard-like metal-insulator transition.
Resonant effects vary in different scattering geometries, corresponding to the
symmetries of the charge excitations scattered by the light. We do find that
the Raman response is large near the double resonance, where the transfered
frequency is close to the incident photon frequency. We also find a joint
resonance of both the charge-transfer peak and the low-energy peak when the
incident photon frequency is on the order of the interaction strength. In
general, the resonance effects can create order of magnitude (or more)
enhancements of features in the nonresonant response, especially when the
incident photon frequency is somewhat larger than the frequency of the
nonresonant feature. Finally, we find that the resonant effects also exhibit
isosbestic behavior, even in the A1g and B2g sectors, and it is most prominent
when the incident photon frequency is on the order of the interaction energy.",0408400v1
2004-10-07,Resonant spin Hall conductance in quantum Hall systems lacking bulk and structural inversion symmetry,"Following a previous work [Shen, Ma, Xie and Zhang, Phys. Rev. Lett. 92,
256603 (2004)] on the resonant spin Hall effect, we present detailed
calculations of the spin Hall conductance in two-dimensional quantum wells in a
strong perpendicular magnetic field. The Rashba coupling, generated by
spin-orbit interaction in wells lacking bulk inversion symmetry, introduces a
degeneracy of Zeeman-split Landau levels at certain magnetic fields. This
degeneracy, if occuring at the Fermi energy, will induce a resonance in the
spin Hall conductance below a characteristic temperature of order of the Zeeman
energy. At very low temperatures, the spin Hall current is highly non-ohmic.
The Dresselhaus coupling due to the lack of structure inversion symmetry
partially or completely suppresses the spin Hall resonance. The condition for
the resonant spin Hall conductance in the presence of both Rashba and
Dresselhaus couplings is derived using a perturbation method. In the presence
of disorder, we argue that the resonant spin Hall conductance occurs when the
two Zeeman split extended states near the Fermi level becomes degenerate due to
the Rashba coupling and that the the quantized charge Hall conductance changes
by 2e^2/h instead of e^2/h as the magnetic field changes through the resonant
field.",0410169v1
2005-03-27,Magnetic Vortex Resonance in Patterned Ferromagnetic Dots,"We report a high-resolution experimental detection of the resonant behavior
of magnetic vortices confined in small disk-shaped ferromagnetic dots. The
samples are magnetically soft Fe-Ni disks of diameter 1.1 and 2.2 um, and
thickness 20 and 40 nm patterned via electron beam lithography onto microwave
co-planar waveguides. The vortex excitation spectra were probed by a vector
network analyzer operating in reflection mode, which records the derivative of
the real and the imaginary impedance as a function of frequency. The spectra
show well-defined resonance peaks in magnetic fields smaller than the
characteristic vortex annihilation field. Resonances at 162 and 272 MHz were
detected for 2.2 and 1.1 um disks with thickness 40 nm, respectively. A
resonance peak at 83 MHz was detected for 20-nm thick, 2-um diameter disks. The
resonance frequencies exhibit weak field dependence, and scale as a function of
the dot geometrical aspect ratio. The measured frequencies are well described
by micromagnetic and analytical calculations that rely only on known properties
of the dots (such as the dot diameter, thickness, saturation magnetization, and
exchange stiffness constant) without any adjustable parameters. We find that
the observed resonance originates from the translational motion of the magnetic
vortex core.",0503632v1
2006-03-24,Resonance reactions and enhancement of weak interactions in collisions of cold molecules,"With the creation of ultracold atoms and molecules, a new type of chemistry -
""resonance"" chemistry - emerges: chemical reactions can occur when the energy
of colliding atoms and molecules matches a bound state of the combined molecule
(Feshbach resonance). This chemistry is rather similar to reactions that take
place in nuclei at low energies. In this paper we suggest some problems for
future experimental and theoretical work related to the resonance chemistry of
ultracold molecules. Molecular Bose-Einstein condensates are particularly
interesting because in this system collisions and chemical reactions are
extremely sensitive to weak fields; also, a preferred reaction channel may be
enhanced due to a finite number of final states. The sensitivity to weak fields
arises due to the high density of narrow compound resonances and the
macroscopic number of molecules with kinetic energy E=0 (in the ground state of
a mean-field potential). The high sensitivity to the magnetic field may be used
to measure the distribution of energy intervals, widths, and magnetic moments
of compound resonances and study the onset of quantum chaos. A difference in
the production rate of right-handed and left-handed chiral molecules may be
produced by external electric and magnetic fields and the finite width of the
resonance. The same effect may be produced by the parity-violating energy
difference in chiral molecules.",0603639v2
2006-06-28,Influence of Random Bulk Inhomogeneities on Quasi-Optical Cavity Resonator Spectrum,"We suggest the statistical spectral theory of oscillations in quasi-optical
cavity resonator filled with random inhomogeneities. It is shown that
inhomogeneities in the resonator result in intermode scattering leading to the
shift and broadening of spectral lines. The shift and broadening of each line
essentially depends on frequency distance to adjacent spectral lines. With
increasing the distance the influence of inhomogeneities sharply reduces. The
solitary spectral lines which have the distance to the nearest lines quite
large is slightly changed due to small inhomogeneities. Owing to such selective
influence of inhomogeneities on the spectral lines the effective spectrum
rarefaction appears. Both the shift and broadening of spectral lines as well as
spectrum rarefaction in quasi-optical cavity millimeter wave resonator were
detected experimentally. We found out that inhomogeneities result in
stochastization of the resonator spectrum in that mixed state appears, i.e. the
spectrum acquires both regular and random parts. The active self-oscillator
system based on the inhomogeneous quasi-optical cavity millimeter wave
resonator with Gunn diode was studied as well. The inhomogeneous quasi-optical
cavity millimeter wave resonator (passive and active) can serve as a model of
semiconductor quantum billiard. Based on our results we suggest using such
billiards with spectrum rarefied by random inhomogeneities as an active system
of semiconductor laser.",0606740v1
2006-07-05,Resonance in the electron-doped high-Tc superconductor Pr0.88LaCe0.12CuO(4-delta),"In conventional superconductors, the interaction that pairs the electrons to
form the superconducting state is mediated by lattice vibrations (phonons). In
high-transition temperature (high-Tc) copper oxides, it is generally believed
that magnetic excitations play a fundamental role in the superconducting
mechanism because superconductivity occurs when mobile 'electrons' or 'holes'
are doped into the antiferromagnetic parent compounds. Indeed, a sharp magnetic
excitation termed ""resonance"" has been observed by neutron scattering in a
number of hole-doped materials. The resonance is intimately related to
superconductivity, and its interaction with charged quasi-particles observed by
photoemission, optical conductivity, and tunneling suggests that it plays a
similar role as phonons in conventional superconductors. However, the relevance
of the resonance to high-Tc superconductivity has been in doubt because so far
it has been found only in hole-doped materials. Here we report the discovery of
the resonance in electron-doped superconducting Pr0.88LaCe0.12CuO(4-delta) (Tc
= 24 K). We find that the resonance energy (Er) is proportional to Tc via Er =
5.8kBTc (kB is the Boltzmann's constant) for all high-Tc superconductors
irrespective of electron- or hole-doping (Fig. 1e). Our results demonstrate
that the resonance is a fundamental property of the superconducting copper
oxides and therefore must play an essential role in the mechanism of
superconductivity.",0607134v1
2006-09-05,Observation and resonant x-ray optical interpretation of multi-atom resonant photoemission effects in O 1s emission from NiO,"We present experimental and theoretical results for the variation of the O 1s
intensity from a NiO(001) surface as the excitation energy is varied through
the Ni 2p1/2,3/2 absorption resonances, and as the incidence angle of the
radiation is varied from grazing to larger values. For grazing incidence, a
strong multi-atom resonant photoemission (MARPE) effect is seen on the O 1s
intensity as the Ni 2p resonances are crossed, but its magnitude decreases
rapidly as the incidence angle is increased. Resonant x-ray optical (RXRO)
calculations are found to predict these effects very well, although the
experimental effects are found to decrease at higher incidence angles faster
than those in theory. The potential influence of photoelectron diffraction
effects on such measurements are also considered, including experimental data
with azimuthal-angle variation and corresponding
multiple-scattering-diffraction calculations, but we conclude that they do not
vary beyond what is expected on the basis of the change in photoelectron
kinetic energy. Varying from linear polarization to circular polarization is
found to enhance these effects in NiO considerably, although the reasons are
not clear. We also discuss the relationship of these measurements to other
related interatomic resonance experiments and theoretical developments, and
make some suggestions for future studies in this area.",0609101v1
2006-11-24,Experimental Evidence for Efimov Quantum States,"Three interacting particles form a system which is well known for its complex
physical behavior. A landmark theoretical result in few-body quantum physics is
Efimov's prediction of a universal set of weakly bound trimer states appearing
for three identical bosons with a resonant two-body interaction. Surprisingly,
these states even exist in the absence of a corresponding two-body bound state
and their precise nature is largely independent of the particular type of the
two-body interaction potential. Efimov's scenario has attracted great interest
in many areas of physics; an experimental test however has not been achieved.
We report the observation of an Efimov resonance in an ultracold thermal gas of
cesium atoms. The resonance occurs in the range of large negative two-body
scattering lengths and arises from the coupling of three free atoms to an
Efimov trimer. We observe its signature as a giant three-body recombination
loss when the strength of the two-body interaction is varied near a Feshbach
resonance. This resonance develops into a continuum resonance at non-zero
collision energies, and we observe a shift of the resonance position as a
function of temperature. We also report on a minimum in the recombination loss
for positive scattering lengths, indicating destructive interference of decay
pathways. Our results confirm central theoretical predictions of Efimov physics
and represent a starting point from which to explore the universal properties
of resonantly interacting few-body systems.",0611629v1
1997-05-19,Structure of Resonance in Preheating after Inflation,"We consider preheating in the theory $1/4 \lambda \phi^4 + 1/2
g^2\phi^2\chi^2 $, where the classical oscillating inflaton field $\phi$ decays
into $\chi$-particles and $\phi$-particles. The parametric resonance which
leads to particle production in this conformally invariant theory is described
by the Lame equation. It significantly differs from the resonance in the theory
with a quadratic potential. The structure of the resonance depends in a rather
nontrivial way on the parameter $g^2/\lambda$. We construct the
stability/instability chart in this theory for arbitrary $g^2/\lambda$. We give
simple analytic solutions describing the resonance in the limiting cases
$g^2/\lambda\ll 1$ and $g^2/\lambda \gg 1$, and in the theory with
$g^2=3\lambda$, and with $g^2 =\lambda$. From the point of view of parametric
resonance for $\chi$, the theories with $g^2=3\lambda$ and with $g^2 =\lambda$
have the same structure, respectively, as the theory $1/4 \lambda \phi^4$, and
the theory $\lambda /(4 N) (\phi^2_i)^2$ of an N-component scalar field
$\phi_i$ in the limit $N \to \infty$. We show that in some of the conformally
invariant theories such as the simplest model $1/4 \lambda\phi^4$, the
resonance can be terminated by the backreaction of produced particles long
before $<\chi^2>$ or $<\phi^2 >$ become of the order $\phi^2$. We analyze the
changes in the theory of reheating in this model which appear if the inflaton
field has a small mass.",9705347v1
1997-10-04,Broad Sub-Continuum Resonances and the Case for Finite-Energy Sum-Rules,"There is a need to go beyond the narrow resonance approximation for QCD
sum-rule channels which are likely to exhibit sensitivity to broad resonance
structures. We first discuss how the first two Laplace sum rules are altered
when one goes beyond the narrow resonance approximation to include possible
subcontinuum resonances with nonzero widths. We then show that the
corresponding first two finite energy sum rules are insensitive to the widths
of such resonances, provided their peaks are symmetric and entirely below the
continuum threshold. We also discuss the reduced sensitivity of the first two
finite energy sum rules to higher dimensional condensates, and show these sum
rules to be insensitive to dimension > 6 condensates containing at least one
q-bar q pair. We extract the direct single-instanton contribution to the F_1
sum rule for the longitudinal component of the axial-vector correlation
function from the known single-instanton contribution to the lowest Laplace sum
rule for the pseudoscalar channel. Finally, we demonstrate how inclusion of
this instanton contribution to the finite-energy sum rule leads to both a
lighter quark mass and to more phenomenologically reasonable higher-mass
resonance contributions within the pseudoscalar channel.",9710240v1
1998-01-26,QCD Sum-Rule Consistency of Lowest-Lying Quark Scalar Resonances,"We investigate lowest-lying scalar meson properties predicted from QCD
Laplace sum rules based upon isovector and isoscalar non-strange $\bar{q}q$
currents. The hadronic content of these sum rules incorporates deviations from
the narrow resonance approximation anticipated from physical resonance widths.
The field theoretical content of these sum rules incorporates
purely-perturbative QCD contributions to three-loop order, the direct
single-instanton contribution in the instanton liquid model, and leading
contributions from QCD-vacuum condensates. In the isovector channel, the
results we obtain are compatible with a$_0$(1450) being the lowest-lying
$q\bar{q}$ resonance, and are indicative of a non-$q\bar{q}$ interpretation for
a$_0$(980). In the isoscalar channel, the results we obtain are compatible with
the lowest lying $q\bar{q}$ resonance being f$_0$(980) or a state somewhat
lighter than f$_0$(980) whose width is less than half of its mass. The dilaton
scenario for such a narrower $\sigma$-resonance is discussed in detail, and is
found compatible with sum rule predictions for the resonance coupling only if
the anomalous gluon-field portion of $\Theta_\mu^\mu$ dominates the matrix
element $<\sigma|\Theta_\mu^\mu|0>$. A linear sigma-model interpretation of the
lowest-lying resonance's coupling, when compared to the coupling predicted by
sum rules, is indicative of a renormalization-group invariant light-quark mass
between 4 and 6 MeV.",9801415v1
1998-08-30,Sine-Gordon Parametric Resonance,"We consider the instability of fluctuations in an oscillating scalar field
which obeys the Sine-Gordon equation. We present simple closed-form analytic
solutions describing the parametric resonance in the Sine-Gordon model. The
structure of the resonance differs from that obtained with the Mathieu equation
which is usually derived with the small angle approximation to the equation for
fluctuations. The results are applied to axion cosmology, where the
oscillations of the classical axion field, with a Sine-Gordon self-interaction
potential, constitute the cold dark matter of the universe. When the axion
misalignment angle at the QCD epoch, $\theta_0$, is small, the parametric
resonance of the axion fluctuations is not significant. However, in regions of
larger $\theta_0$ where axion miniclusters would form, the resonance may be
important. As a result, axion miniclusters may disintegrate into finer, denser
clumps. We also apply the theory of Sine-Gordon parametric resonance to
reheating in the Natural Inflation scenario. The decay of the inflaton field
due to the self-interaction alone is ineffective, but a coupling to other
bosons can lead to preheating in the broad resonance regime. Together with the
preheating of fermions, this can alter the reheating scenario for Natural
Inflation.",9808477v1
1998-09-30,New Enhancement Mechanism of the Transitions in the Earth of the Solar and Atmospheric Neutrinos Crossing the Earth Core,"It is shown that the $\nu_2 \to \nu_{e}$ and $\nu_{\mu} \to \nu_{e}$ ($\nu_e
\to \nu_{\mu (\tau)}$) transitions respectively of the solar and atmospheric
neutrinos in the Earth in the case of $\nu_e - \nu_{\mu (\tau)}$ mixing in
vacuum, are strongly enhanced by a new type of resonance when the neutrinos
cross the Earth core. The resonance is operative at small mixing angles but
differs from the MSW one. It is in many respects similar to the electron
paramagnetic resonance taking place in a specific configuration of two magnetic
fields. The conditions for existence of the new resonance include, in
particular, specific constraints on the neutrino oscillation lengths in the
Earth mantle and in the Earth core, thus the resonance is a ``neutrino
oscillation length resonance''. It leads also to enhancement of the $\nu_2 \to
\nu_e$ and $\nu_e \to \nu_s$ transitions in the case of $\nu_e - \nu_s$ mixing
and of the $\bar{\nu}_{\mu} \to \bar{\nu}_{s}$ (or $\nu_{\mu} \to \nu_{s}$)
transitions at small mixing angles. The presence of the neutrino oscillation
length resonance in the transitions of solar and atmospheric neutrinos
traversing the Earth core has important implications for current and future
solar and atmospheric neutrino experiments, and more specifically, for the
interpretation of the results of the Super-Kamiokande experiment.",9809587v1
1998-11-27,Are the production and decay of a resonance always independent?,"The widely accepted assumption that the decay of a resonance proceeds
independently of its production, quantitatively expressed as a factorizing
formula for the differential cross section in the invariant mass of unpolarized
resonance debris, is put under scrutiny. It is shown that the factorization is
always valid for scalar and pseudoscalar resonances, although the usual version
of the formula is not entirely correct. For resonances with nonzero spins the
factorization does not generally take place. We deal in more detail with the
spin-one case, where we show a condition on the decay matrix element that
ensures the validity of the same factorizing formula as in the spinless case.
This condition is satisfied for rho --> pi pi but not, e.g., for K* --> pi K or
a1 --> pi rho. The formalism is applied also to the case when the resonance is
produced not in two-body collisions but in the decay of a heavier particle or
resonance (chain decay). Application of our formulas to the e+e- production in
one-photon approximation agrees with what is known from quantum electrodynamics
and thus provides another test of their soundness.",9811493v1
2002-06-25,Strange Hadron Resonances: Freeze-Out Probes in Heavy-Ion Collisions,"Hyperon resonances are becoming an extremely useful tool allowing the study
of the properties of hadronic fireballs made in heavy ion collisions. Their
yield, compared to stable particles with the same quark composition, depends on
hadronization conditions. The resonance's short lifetime makes them ideal
probes of the fireball chemical freeze-out mechanisms. An analysis of resonance
abundance in heavy ion collisions should be capable of distinguishing between
possible hadronization scenarios, in particular between sudden and gradual
hadronization. In this paper, we review the existing SPS and RHIC experimental
data on resonance production in heavy ion collisions, and discuss in terms of
both thermal and microscopic models the yields of the two observed resonances,
K* and Lambda(1520). We show how freeze-out properties, namely chemical
freeze-out temperature and the lifetime of the interacting hadron phase which
follows, can be related to resonance yields. Finally, we apply these methods to
SPS and RHIC measurements, discuss the significance and interpretations of our
findings, and suggest further measurements which may help in clarifying
existing ambiguities.",0206260v2
2005-08-14,Stable manifolds and homoclinic points near resonances in the restricted three-body problem,"The restricted three-body problem describes the motion of a massless particle
under the influence of two primaries of masses $1-\mu$ and $\mu$ that circle
each other with period equal to $2\pi$. For small $\mu$, a resonant periodic
motion of the massless particle in the rotating frame can be described by
relatively prime integers $p$ and $q$, if its period around the heavier primary
is approximately $2\pi p/q$, and by its approximate eccentricity $e$. We give a
method for the formal development of the stable and unstable manifolds
associated with these resonant motions. We prove the validity of this formal
development and the existence of homoclinic points in the resonant region.
  In the study of the Kirkwood gaps in the asteroid belt, the separatrices of
the averaged equations of the restricted three-body problem are commonly used
to derive analytical approximations to the boundaries of the resonances. We use
the unaveraged equations to find values of asteroid eccentricity below which
these approximations will not hold for the Kirkwood gaps with $q/p$ equal to
2/1, 7/3, 5/2, 3/1, and 4/1.
  Another application is to the existence of asymmetric librations in the
exterior resonances. We give values of asteroid eccentricity below which
asymmetric librations will not exist for the 1/7, 1/6, 1/5, 1/4, 1/3, and 1/2
resonances for any $\mu$ however small. But if the eccentricity exceeds these
thresholds, asymmetric librations will exist for $\mu$ small enough in the
unaveraged restricted three-body problem.",0508246v1
1997-01-17,Resonance Production on Nuclei at High Energies: Nuclear-Medium Effects and Space-Time Picture,"The influence of nuclear matter on the properties of coherently produced
resonances is discussed. It is shown that, in general, the mass distribution of
resonance decay products has a two-component structure corresponding to decay
outside and inside the nucleus. The first (narrow) component of the amplitude
has a Breit-Wigner form determined by the vacuum values of mass and width of
the resonance. The second (broad) component corresponds to interactions of the
resonance with the nuclear medium. It can be also described by a Breit-Wigner
shape with parameters depending e.g. on the nuclear density and on the cross
section of the resonance-nucleon interaction. The resonance production is
examined both at intermediate energies, where interactions with the nucleus can
be considered as a series of successive local rescatterings, and at high
energies, $E>E_{crit}$, where a change of interaction picture occurs. This
change of mechanisms of the interactions with the nucleus is typical for the
description within the Regge theory approach and is connected with the nonlocal
nature of the reggeon interaction.",9701031v2
1997-08-05,The Spectral Function of the Rho Meson in Nuclear Matter,"We calculate the modification of a rho meson in nuclear matter through its
coupling to resonance-hole states. Starting from a recently proposed model, we
include all four star resonances up to 1.9 GeV. In contrast to previous works,
we include not only resonances that couple to the rho in a relative p-wave, but
also those that couple to an s-wave state. In addition, we solve the equation
for the rho spectral function self-consistently. We find that s-wave resonances
affect the in medium spectral function of the rho strongly. In the transverse
channel the rho meson is, especially at non zero momentum, completely washed
out and can in the presence of nuclear matter no longer be viewed as a resonant
excitation of the vacuum. Instead, our model shows a continuum of possible
excitations with the quantum numbers of a transversely polarized rho. In the
longitudinal channel, however, the rho retains its resonant character in our
calculation. As a consequence of the self-consistent treatment we also find a
strong enhancement of the widths of the included nucleon resonances in medium.",9708004v2
2003-07-03,Effect of Resonant Continuum on Pairing Correlations in the Relativistic Approach,"A proper treatment of the resonant continuum is to take account of not only
the energy of the resonant state, but also its width. The effect of the
resonant states on pairing correlations is presented based on the relativistic
mean field theory plus Bardeen-Cooper-Schrieffer(BCS) approximation with a
constant pairing strength. The study is performed in an effective Lagrangian
with the parameter set NL3 for neutron rich even-even Ni isotopes. The results
show that the contribution of the proper treatment of the resonant continuum to
pairing correlations for those nuclei close to neutron drip line is important.
The pairing gaps, Fermi energies, pairing correlation energies, and binding
energies are considerably affected with a proper consideration of the width of
resonant states. The problem of an unphysical particle gas, which may appear in
the calculation of the traditional mean field plus BCS method for nuclei in the
vicinity of drip line could be well overcome when the pairing correlation is
performed by using the resonant states instead of the discretized states in the
continuum.",0307016v4
2004-12-15,Resonant dt-mu formation in condensed hydrogens,"Resonant formation of the muonic molecule dt-mu in t-mu atom collision with
condensed H/D/T targets is considered. A specific resonance correlation
function, which is a generalization of the Van Hove single-particle correlation
function, is introduced to calculate the resonant-formation rate in such
targets. This function is derived in the case of a polycrystalline harmonic
solid. Also is found a general asymptotic form of the resonance correlation
function for high momentum transfers, valid for any solid or dense-fluid
hydrogen-isotope target.
  Numerical calculations of the rates are performed for solid molecular
hydrogens at zero pressure, using the Debye model of an isotropic solid. It is
shown that condensed-matter effects in resonant formation are strong, which
explains some unexpected experimental results. In particular, the resonance
profiles are affected by large zero-point vibrations of the hydrogen-isotope
molecules bound in the considered crystals, even for high (1 eV) collision
energies. This is important for explanation of the time-of-flight measurements
of the dt-mu-formation rate, carried out at TRIUMF. The calculated mean values
of the dt-mu-formation rate in solid D/T targets, for fixed target temperatures
and steady-state conditions, are in good agreement with the PSI and RIKEN-RAL
experiments.",0412090v2
2006-06-28,Analytical Solution for the Deformation of a Cylinder under Tidal Gravitational Forces,"Quite a few future high precision space missions for testing Special and
General Relativity will use optical resonators which are used for laser
frequency stabilization. These devices are used for carrying out tests of the
isotropy of light (Michelson-Morley experiment) and of the universality of the
gravitational redshift. As the resonator frequency not only depends on the
speed of light but also on the resonator length, the quality of these
measurements is very sensitive to elastic deformations of the optical resonator
itself. As a consequence, a detailed knowledge about the deformations of the
cavity is necessary. Therefore in this article we investigate the modeling of
optical resonators in a space environment. Usually for simulation issues the
Finite Element Method (FEM) is applied in order to investigate the influence of
disturbances on the resonator measurements. However, for a careful control of
the numerical quality of FEM simulations a comparison with an analytical
solution of a simplified resonator model is beneficial. In this article we
present an analytical solution for the problem of an elastic, isotropic,
homogeneous free-flying cylinder in space under the influence of a tidal
gravitational force. The solution is gained by solving the linear equations of
elasticity for special boundary conditions. The applicability of using FEM
codes for these simulations shall be verified through the comparison of the
analytical solution with the results gained within the FEM code.",0606250v1
2007-03-13,Q-based design equations for resonant metamaterials and experimental validation,"Practical design parameters of resonant metamaterials, such as loss tangent,
are derived in terms of the quality factor $Q$ of the resonant effective medium
permeability or permittivity. Through electromagnetic simulations of loop-based
resonant particles, it is also shown that the $Q$ of the effective medium
response is essentially equal to the $Q$ of an individual resonant particle.
Thus, by measuring the $Q$ of a single fabricated metamaterial particle, the
effective permeability or permittivity of a metamaterial can be calculated
simply and accurately without requiring complex simulations, fabrication, or
measurements. Experimental validation shows that the complex permeability
analytically estimated from the measured $Q$ of a single fabricated
self-resonant loop agrees with the complex permeability extracted from $S$
parameter measurements of a metamaterial slab to better than 20%. This $Q$
equivalence reduces the design of a metamaterial to meet a given loss
constraint to the simpler problem of the design of a resonant particle to meet
a specific $Q$ constraint. This analysis also yields simple analytical
expressions for estimating the loss tangent of a planar loop magnetic
metamaterial due to ohmic losses. It is shown that $\tan \delta \approx 0.001$
is a strong lower bound for magnetic loss tangents for frequencies not too far
from 1 GHz. The ohmic loss of the metamaterial varies inversely with the
electrical size of the metamaterial particle, indicating that there is a loss
penalty for reducing the particle size at a fixed frequency.",0703130v1
2004-09-26,Superconducting Qubits Coupled to Nanoelectromechanical Resonators: An Architecture for Solid-State Quantum Information Processing,"We describe the design for a scalable, solid-state
quantum-information-processing architecture based on the integration of
GHz-frequency nanomechanical resonators with Josephson tunnel junctions, which
has the potential for demonstrating a variety of single- and multi-qubit
operations critical to quantum computation. The computational qubits are
eigenstates of large-area, current-biased Josephson junctions, manipulated and
measured using strobed external circuitry. Two or more of these phase qubits
are capacitively coupled to a high-quality-factor piezoelectric
nanoelectromechanical disk resonator, which forms the backbone of our
architecture, and which enables coherent coupling of the qubits. The integrated
system is analogous to one or more few-level atoms (the Josephson junction
qubits) in an electromagnetic cavity (the nanomechanical resonator). However,
unlike existing approaches using atoms in electromagnetic cavities, here we can
individually tune the level spacing of the ``atoms'' and control their
``electromagnetic'' interaction strength. We show theoretically that quantum
states prepared in a Josephson junction can be passed to the nanomechanical
resonator and stored there, and then can be passed back to the original
junction or transferred to another with high fidelity. The resonator can also
be used to produce maximally entangled Bell states between a pair of Josephson
junctions. Many such junction-resonator complexes can assembled in a
hub-and-spoke layout, resulting in a large-scale quantum circuit. Our proposed
architecture combines desirable features of both solid-state and cavity quantum
electrodynamics approaches, and could make quantum information processing
possible in a scalable, solid-state environment.",0409179v1
2007-05-10,Some properties of the resonant state in quantum mechanics and its computation,"The resonant state of the open quantum system is studied from the viewpoint
of the outgoing momentum flux. We show that the number of particles is
conserved for a resonant state, if we use an expanding volume of integration in
order to take account of the outgoing momentum flux; the number of particles
would decay exponentially in a fixed volume of integration. Moreover, we
introduce new numerical methods of treating the resonant state with the use of
the effective potential. We first give a numerical method of finding a
resonance pole in the complex energy plane. The method seeks an energy
eigenvalue iteratively. We found that our method leads to a super-convergence,
the convergence exponential with respect to the iteration step. The present
method is completely independent of commonly used complex scaling. We also give
a numerical trick for computing the time evolution of the resonant state in a
limited spatial area. Since the wave function of the resonant state is
diverging away from the scattering potential, it has been previously difficult
to follow its time evolution numerically in a finite area.",0705.1388v2
2007-06-06,Radiative Transfer Effect on Ultraviolet Pumping of the 21cm Line in the High Redshift Universe,"During the epoch of reionization the 21cm signal is sensitive to the
scattering rate of the ultraviolet photons, redshifting across the Lyman_alpha
resonance. Here we calculate the photon scattering rate profile for a single
ultraviolet source. After taking into account previously neglected natural
broadening of the resonance line, we find that photons approach the resonance
frequency and experience most scatterings at a significantly smaller distance
from the source than naively expected r=(dnu/nu_0)(c/H), where dnu=nu-nu_0 is
the initial frequency offset, and the discrepancy increases as the initial
frequency offset decreases. As a consequence, the scattering rate P(r) drops
much faster with increasing distance than the previously assumed 1/r^2 profile.
Near the source (r<1Mpc comoving), the scattering rate of photons that redshift
into the Ly_alpha resonance converges to P(r) \propto r^{-7/3}. The scattering
rate of Ly_alpha photons produced by splitting of photons that redshift into a
higher resonance (Ly_gamma, Ly_delta, etc.) is only weakly affected by the
radiative transfer, while the sum of scattering rates of Ly_alpha photons
produced from all higher resonances also converges to P(r) \propto r^{-7/3}
near the source. At 15<z<35, on scales of ~0.01-20Mpc/h (comoving), the total
scattering rate of Ly_alpha photons from all Lyman resonances is found to be
higher by a factor of ~1+0.3[(1+z)/20]^{2/3} than obtained without full
radiative transfer. Consequently, during the early stage of reionization, the
differential brightness of 21cm signal against the cosmic microwave background
is also boosted by a similar factor.",0706.0895v1
2007-10-01,Intrinsic dissipation in nanomechanical resonators due to phonon tunneling,"State of the art nanomechanical resonators present quality factors Q ~ 10^3 -
10^5, which are much lower than those that can be naively extrapolated from the
behavior of micromechanical resonators. We analyze the dissipation mechanism
that arises in nanomechanical beam-structures due to the tunneling of
mesoscopic phonons between the beam and its supports (known as clamping
losses). We derive the environmental force spectral density that determines the
quantum Brownian motion of a given resonance. Our treatment is valid for low
frequencies and provides the leading contribution in the aspect ratio. This
yields fundamental limits for the Q-values which are described by simple
scaling laws and are relevant for state of the art experimental structures. In
this context, for resonant frequencies in the 0.1-1GHz range, while this
dissipation mechanism can limit flexural resonators it is found to be
negligible for torsional ones. In the case of structureless 3D supports the
corresponding environmental spectral densities are Ohmic for flexural
resonators and super-Ohmic for torsional ones, while for 2D slab supports they
yield 1/f noise. Furthermore analogous results are established for the case of
suspended semiconducting single-walled carbon nanotubes. Finally, we provide a
general expression for the spectral density that allows to extend our treatment
to other geometries and illustrate its use by applying it to a microtoroid. Our
analysis is relevant for applications in high precision measurements and for
the prospects of probing quantum effects in a macroscopic mechanical degree of
freedom.",0710.0200v2
2008-02-21,Silicon on Nothing Mems Electromechanical Resonator,"The very significant growth of the wireless communication industry has
spawned tremendous interest in the development of high performances radio
frequencies (RF) components. Micro Electro Mechanical Systems (MEMS) are good
candidates to allow reconfigurable RF functions such as filters, oscillators or
antennas. This paper will focus on the MEMS electromechanical resonators which
show interesting performances to replace SAW filters or quartz reference
oscillators, allowing smaller integrated functions with lower power
consumption. The resonant frequency depends on the material properties, such as
Young's modulus and density, and on the movable mechanical structure dimensions
(beam length defined by photolithography). Thus, it is possible to obtain multi
frequencies resonators on a wafer. The resonator performance (frequency,
quality factor) strongly depends on the environment, like moisture or pressure,
which imply the need for a vacuum package. This paper will present first
resonator mechanisms and mechanical behaviors followed by state of the art
descriptions with applications and specifications overview. Then MEMS resonator
developments at STMicroelectronics including FEM analysis, technological
developments and characterization are detailed.",0802.3051v1
2008-05-06,Negative refraction by a virtual photonic lattice,"Research on photonics and metamaterials constantly challenges our intuitive
understanding of the behaviour of light. In recent years we have seen negative
refraction, focusing of light by a flat slab, a ``perfect'' prism, and an
``invisibility cloak'' [1-6]. It is generally understood that the cause of this
unusual behaviour is the strong (anomalous) dispersion, i.e., dependence of the
material properties on the frequency of light. Dispersion can be either due to
a natural microscopic resonance of the material as with surface
plasmons-polaritons, or due to an effective resonance (band-gap) of the
periodic lattice as in photonics [7-9]. Metamaterials take the better of the
two approaches representing a periodic array of designer subwavelength
particles tuned to resonate at a specific frequency-band. At present, however,
we have only a very basic understanding of the effect which a finite size of a
sample of a periodic photonic crystal or metamaterial has on the macroscopic
properties such as refraction. Yet every finite dielectric object is a
moderate-quality resonator whose eigenmodes form a virtual photonic lattice
with its own angular band-gaps and preferred directions of propagation. Here we
show that this virtual lattice produces nontrivial real effects and that even a
homogeneous dielectric resonator may refract negatively without either negative
or periodically modulated permittivity/permeability. We also propose a simple
way to control the period of this virtual photonic lattice by varying the
transverse dimension of the resonator. Our research shows the importance of
three-dimensional resonant phenomena in optics and may result in new optical
devices with unusual properties.",0805.0769v1
2008-09-20,The resonant structure of Jupiter's trojan asteroids-II. What happens for different configurations of the planetary system,"In a previous paper, we have found that the resonance structure of the
present Jupiter Trojan swarms could be split up into four different families of
resonances. Here, in a first step, we generalize these families in order to
describe the resonances occurring in Trojan swarms embedded in a generic
planetary system. The location of these families changes under a modification
of the fundamental frequencies of the planets and we show how the resonant
structure would evolve during a planetary migration. We present a general
method, based on the knowledge of the fundamental frequencies of the planets
and on those that can be reached by the Trojans, which makes it possible to
predict and localize the main events arising in the swarms during migration. In
particular, we show how the size and stability of the Trojan swarms are
affected by the modification of the frequencies of the planets. Finally, we use
this method to study the global dynamics of the Jovian Trojan swarms when
Saturn migrates outwards. Besides the two resonances found by Morbidelli et al
(2005) which could have led to the capture of the current population just after
the crossing of the 2:1 orbital resonance, we also point out several sequences
of chaotic events that can influence the Trojan population.",0809.3526v2
2008-11-28,The dynamics of satellite disruption in cold dark matter haloes,"We investigate the physical mechanisms of tidal heating and satellite
disruption in cold dark matter host haloes using N-body simulations based on
cosmological initial conditions. We show the importance of resonant shocks and
resonant torques with the host halo to satellite heating. A resonant shock
(torque) couples the radial (tangential) motion of a satellite in its orbit to
its phase space. For a satellite on a circular orbit, an ILR-like resonance
dominates the heating and this heating results in continuous satellite mass
loss. We estimate the requirements for simulations to achieve these dynamics
using perturbation theory. Both resonant shocks and resonant torques affect
satellites on eccentric orbits. We demonstrate that satellite mass loss is an
outside-in process in energy space; a satellite's stars and gas are thus
protected by their own halo against tidal stripping. We simulate the evolution
of a halo similar to the Large Magellanic Cloud (LMC) in our Galactic dark
matter halo and conclude that the LMC stars have not yet been stripped.
Finally, we present a simple algorithm for estimating the evolution of
satellite mass that includes both shock heating and resonant torques.",0812.0009v2
2008-12-01,Stability of the directly imaged multiplanet system HR 8799: resonance and masses,"A new era of directly imaged extrasolar planets has produced a three-planet
system (Marois et al. 2008), where the masses of the planets have been
estimated by untested cooling models. We point out that the nominal circular,
face-on orbits of the planets lead to a dynamical instability in ~10^5 yr, a
factor of at least 100 shorter than the estimated age of the star. Reduced
planetary masses produce stability only for unreasonably small planets (<~2 M_
Jup). Relaxing the face-on assumption, but still requiring circular orbits
while fitting the observed positions, makes the instability time even shorter.
A promising solution is that the inner two planets have a 2:1 commensurability
between their periods, and they avoid close encounters with each other through
this resonance. That the inner resonance has lasted until now, in spite of the
perturbations of the outer planet, leads to a limit <~10 M_Jup on the masses
unless the outer two planets are also engaged in a 2:1 mean-motion resonance.
In a double resonance, which is consistent with the current data, the system
could survive until now even if the planets have masses of ~20 M_Jup. Apsidal
alignment can further enhance the stability of a mean-motion resonant system. A
completely different dynamical configuration, with large eccentricities and
large mutual inclinations among the planets, is possible but finely tuned.",0812.0011v2
2009-05-04,Detectability and Error Estimation in Orbital Fits,"We estimate the conditions for detectability of two planets in a 2/1
mean-motion resonance from radial velocity data, as a function of their masses,
number of observations and the signal-to-noise ratio. Even for a data set of
the order of 100 observations and standard deviations of the order of a few
meters per second, we find that Jovian-size resonant planets are difficult to
detect if the masses of the planets differ by a factor larger than $\sim 4$.
This is consistent with the present population of real exosystems in the 2/1
commensurability, most of which have resonant pairs with similar minimum
masses, and could indicate that many other resonant systems exist, but are
presently beyond the detectability limit.
  Furthermore, we analyze the error distribution in masses and orbital elements
of orbital fits from synthetic data sets for resonant planets in the 2/1
commensurability. For various mass ratios and number of data points we find
that the eccentricity of the outer planet is systematically over estimated,
although the inner planet's eccentricity suffers a much smaller effect. If the
initial conditions correspond to small amplitude oscillations around stable
apsidal corotation resonances (ACR), the amplitudes estimated from the orbital
fits are biased toward larger amplitudes, in accordance to results found in
real resonant extrasolar systems.",0905.0433v1
2009-05-04,Collective dynamics of interacting Ising spins: Exact results for the Bethe lattice,"We study the low temperature dynamics in films made of molecular magnets, i.
e. crystals composed of molecules having large electronic spin S in their
ground state. The electronic spin dynamics is mediated by coupling to a nuclear
spin bath; this coupling allows transitions for a small fraction of electronic
spins between their two energy minima, Sz=+- S, under resonant conditions when
the change of the Zeeman energy in magnetic dipolar field of other electronic
spins is compensated by interaction with nuclear spins. Transitions of resonant
spins can result in opening or closing resonances in their neighbors leading to
the collective dynamics at sufficiently large density P0 of resonant spins. We
formulate and solve the equivalent dynamic percolation problem for the Bethe
lattice (BL) of spins interacting with z neighbors and find that depending on
the density of resonant spins P0 and the number of neighbors z the system has
either one (2<z<6) or two (z > 5) kinetic transitions at P_{0}=Pc1 ~
exp(-1/3)/(3z) and P0=Pc2 ~ exp(-1)/z. The former transition is continuous and
associated with the formation of an infinite cluster of coupled resonant spins
similarly to the static percolation transition occurring at P0 ~ 1/z. The
latter transition, z>5, is discontinuous and associated with the instantaneous
increase in the density of resonant spins from the small value ~ 1/z to near
unity. Experimental implications of our results are discussed.",0905.0482v1
2009-05-31,Baseline-dependent neutrino oscillations with extra-dimensional shortcuts,"In extra-dimensional scenarios oscillations between active and sterile
neutrinos can be governed by a new resonance in the oscillation amplitude. This
resonance results when cancelation occurs between two phase differences, the
usual kinematic one coming from the neutrino mass-squared difference, and a
geometric one coming from the difference in travel times of the sterile
neutrino through the bulk relative to the active neutrino confined to the
brane. In this work we introduce a specific metric for the brane-bulk system,
from which we explicitly derive extra-dimensional geodesics for the sterile
neutrino, and ultimately the oscillation probability of the active-sterile
two-state system. We find that for an asymmetrically-warped metric, the
resonance condition involves both the neutrino energy E and the travel distance
L on the brane. In other words, the resonant energy may be viewed as
baseline-dependent. We show that to a good approximation, the resonance
condition is not on E or on L, but rather on the product LE. The model is rich
in implications, including the possibility of multiple solutions to the
resonance condition, with ramifications for existing data sets, e.g., LSND and
MiniBooNE. Some phenomenology with these brane-bulk resonances is discussed.",0906.0150v1
2009-07-24,Coupled magnetic plasmons in metamaterials,"Magnetic metamaterials consist of magnetic resonators smaller in size than
their excitation wavelengths. Their unique electromagnetic properties were
characterized by the effective media theory at the early stage. However, the
effective media model does not take into account the interactions between
magnetic elements; thus, the effective properties of bulk metamaterials are the
result of the ""averaged effect"" of many uncoupled resonators. In recent years,
it has been shown that the interaction between magnetic resonators could lead
to some novel phenomena and interesting applications that do not exist in
conventional uncoupled metamaterials. In this paper, we will give a review of
recent developments in magnetic plasmonics arising from the coupling effect in
metamaterials. For the system composed of several identical magnetic
resonators, the coupling between these units produces multiple discrete
resonance modes due to hybridization. In the case of a system comprising an
infinite number of magnetic elements, these multiple discrete resonances can be
extended to form a continuous frequency band by strong coupling. This kind of
broadband and tunable magnetic metamaterial may have interesting applications.
Many novel metamaterials and nanophotonic devices could be developed from
coupled resonator systems in the future.",0907.4208v2
2009-09-10,Constructing the secular architecture of the solar system II: The terrestrial planets,"We investigate the dynamical evolution of the terrestrial planets during the
planetesimal-driven migration of the giant planets. A basic assumption of this
work is that giant planet migration occurred after the completion of
terrestrial planet formation, such as in the models that link the former to the
origin of the Late Heavy Bombardment. The divergent migration of Jupiter and
Saturn causes the g5 eigenfrequency to cross resonances of the form g5=gk with
k ranging from 1 to 4. Consequently these secular resonances cause
large-amplitude responses in the eccentricities of the terrestrial planets. We
show that the resonances g5=g_4 and g5=g3 do not pose a problem if Jupiter and
Saturn have a fast approach and departure from their mutual 2:1 mean motion
resonance. On the other hand, the resonance crossings g5=g2 and g5=g1 are more
of a concern as they tend to yield a terrestrial system incompatible with the
current one. We offer two solutions to this problem. The first uses the fact
that a secular resonance crossing can also damp the amplitude of a Fourier mode
if the latter is large originally. A second scenario involves a 'jumping
Jupiter' in which encounters between an ice giant and Jupiter, without ejection
of the former, cause the latter to migrate away from Saturn much faster than if
migration is driven solely by encounters with planetesimals. In this case, the
g5=g2 and g5=g1 resonances can be jumped over, or occur very briefly.",0909.1891v1
2009-09-10,Two-level system noise reduction for Microwave Kinetic Inductance Detectors,"Noise performance is one of the most crucial aspects of any detector.
Superconducting Microwave Kinetic Inductance Detectors (MKIDs) have an ""excess""
frequency noise that shows up as a small time dependent jitter of the resonance
frequency characterized by the frequency noise power spectrum measured in units
of Hz^2/Hz. Recent studies have shown that this noise almost certainly
originates from a surface layer of two-level system (TLS) defects on the
metallization or substrate. Fluctuation of these TLSs introduces noise in the
resonator due to coupling of the TLS electric dipole moments to the resonator's
electric field. Motivated by a semi-empirical quantitative theory of this noise
mechanism, we have designed and tested new resonator geometries in which the
high-field ""capacitive"" portion of the CPW resonator is replaced by an
interdigitated capacitor (IDC) structure with 10 - 20 micron electrode spacing,
as compared to the 2 micron spacing used for our more conventional CPW
resonators. Measurements show that this new IDC design has dramatically lower
TLS noise, currently by about a factor of ~29 in terms of the frequency noise
power spectrum, corresponding to an improvement of about a factor of 29^(1/2)
in NEP. These new devices are replacing the CPW resonators in our next design
iteration in progress for MKIDCam. Opportunities and prospects for future
reduction of the TLS noise will be discussed.",0909.2060v1
2009-11-12,Mapping the $ν_\odot$ Secular Resonance for Retrograde Irregular Satellites,"Constructing dynamical maps from the filtered output of numerical
integrations, we analyze the structure of the $\nu_\odot$ secular resonance for
fictitious irregular satellites in retrograde orbits. This commensurability is
associated to the secular angle $\theta = \varpi - \varpi_\odot$, where
$\varpi$ is the longitude of pericenter of the satellite and $\varpi_\odot$
corresponds to the (fixed) planetocentric orbit of the Sun. Our study is
performed in the restricted three-body problem, where the satellites are
considered as massless particles around a massive planet and perturbed by the
Sun. Depending on the initial conditions, the resonance presents a diversity of
possible resonant modes, including librations of $\theta$ around zero (as found
for Sinope and Pasiphae) or 180 degrees, as well as asymmetric librations (e.g.
Narvi). Symmetric modes are present in all giant planets, although each regime
appears restricted to certain values of the satellite inclination. Asymmetric
solutions, on the other hand, seem absent around Neptune due to its almost
circular heliocentric orbit. Simulating the effects of a smooth orbital
migration on the satellite, we find that the resonance lock is preserved as
long as the induced change in semimajor axis is much slower compared to the
period of the resonant angle (adiabatic limit). However, the librational mode
may vary during the process, switching between symmetric and asymmetric
oscillations. Finally, we present a simple scaling transformation that allows
to estimate the resonant structure around any giant planet from the results
calculated around a single primary mass.",0911.2427v1
2010-04-30,Formation of the resonant system HD 60532,"Among multi-planet planetary systems there are a large fraction of resonant
systems. Studying the dynamics and formation of these systems can provide
valuable informations on processes taking place in protoplanetary disks where
the planets are thought have been formed. The recently discovered resonant
system HD 60532 is the only confirmed case, in which the central star hosts a
pair of giant planets in 3:1 mean motion resonance. We intend to provide a
physical scenario for the formation of HD 60532, which is consistent with the
orbital solutions derived from the radial velocity measurements. Observations
indicate that the system is in an antisymmetric configuration, while previous
theoretical investigations indicate an asymmetric equilibrium state. The paper
aims at answering this discrepancy as well. We performed two-dimensional
hydrodynamical simulations of thin disks with an embedded pair of massive
planets. Additionally, migration and resonant capture are studied by
gravitational N-body simulations that apply properly parametrized
non-conservative forces. Our simulations suggest that the capture into the 3:1
mean motion resonance takes place only for higher planetary masses, thus
favouring orbital solutions having relatively smaller inclination i=20 degrees.
The system formed by numerical simulations qualitatively show the same
behaviour as HD 60532. We also find that the presence of an inner disk (between
the inner planet and the star) plays a very important role in determining the
final configurations of resonant planetary systems. Its damping effect on the
inner planet's eccentricity is responsible for the observed antisymmetric state
of HD 60532.",1004.5488v1
2010-09-13,On the analogy between a single atom and an optical resonator,"A single atom in free space can have a strong influence on a light beam and a
single photon can have a strong effect on a single atom in free space.
Regarding this interaction, two conceptually different questions can be asked:
can a single atom fully absorb a single photon and can a single atom fully
reflect a light beam. The conditions for achieving the full effect in either
case are different. Here we discuss related questions in the context of an
optical resonator. When shaping a laser pulse properly it will be fully
absorbed by an optical resonator, i.e., no light will be reflected and all the
pulse energy will accumulate inside the resonator before it starts leaking out.
We show in detail that in this case the temporal pulse shape has to match the
time-reversed pulse obtained by the cavity's free decay. On the other hand a
resonator, made of highly reflecting mirrors which normally reflect a large
portion of any incident light, may fully transmit the light, as long as the
light is narrow band and resonant with the cavity. The analogy is the single
atom - normally letting most of the light pass - which under special conditions
may fully reflect the incident light beam. Using this analogy we are able to
study the effects of practical experimental limitations in the atom-photon
coupling, such as finite pulses, bandwidths, and solid angle coverage, and to
use the optical resonator as a test bed for the implementation of the quantum
experiment.",1009.2365v1
2010-09-21,"Positron-molecule interactions: resonant attachment, annihilation, and bound states","This article presents an overview of current understanding of the interaction
of low-energy positrons with molecules with emphasis on resonances, positron
attachment and annihilation. Annihilation rates measured as a function of
positron energy reveal the presence of vibrational Feshbach resonances (VFR)
for many polyatomic molecules. These resonances lead to strong enhancement of
the annihilation rates. They also provide evidence that positrons bind to many
molecular species. A quantitative theory of VFR-mediated attachment to small
molecules is presented. It is tested successfully for selected molecules (e.g.,
methyl halides and methanol) where all modes couple to the positron continuum.
Combination and overtone resonances are observed and their role is elucidated.
In larger molecules, annihilation rates from VFR far exceed those explicable on
the basis of single-mode resonances. These enhancements increase rapidly with
the number of vibrational degrees of freedom. While the details are as yet
unclear, intramolecular vibrational energy redistribution to states that do not
couple directly to the positron continuum appears to be responsible for these
enhanced annihilation rates. Downshifts of the VFR from the vibrational mode
energies have provided binding energies for thirty species. Their dependence
upon molecular parameters and their relationship to positron-atom and
positron-molecule binding energy calculations are discussed. Feshbach
resonances and positron binding to molecules are compared with the analogous
electron-molecule (negative ion) cases. The relationship of VFR-mediated
annihilation to other phenomena such as Doppler-broadening of the gamma-ray
annihilation spectra, annihilation of thermalized positrons in gases, and
annihilation-induced fragmentation of molecules is discussed.",1009.4069v1
2010-10-05,Lindblad resonance torques in relativistic discs: II. Computation of resonance strengths,"We present a fully relativistic computation of the torques due to Lindblad
resonances from perturbers on circular, equatorial orbits on discs around
Schwarzschild and Kerr black holes. The computation proceeds by establishing a
relation between the Lindblad torques and the gravitational waveforms emitted
by the perturber and a test particle in a slightly eccentric orbit at the
radius of the Lindblad resonance. We show that our result reduces to the usual
formula when taking the nonrelativistic limit. Discs around a black hole
possess an m=1 inner Lindblad resonance with no Newtonian Keplerian analogue;
however its strength is very weak even in the moderately relativistic regime
(r/M ~ few tens), which is in part due to the partial cancellation of the two
leading contributions to the resonant amplitude (the gravitoelectric octupole
and gravitomagnetic quadrupole). For equatorial orbits around Kerr black holes,
we find that the m=1 ILR strength is enhanced for retrograde spins and
suppressed for prograde spins. We also find that the torque associated with the
m>=2 inner Lindblad resonances is enhanced relative to the nonrelativistic
case; the enhancement is a factor of 2 for the Schwarzschild hole even when the
perturber is at a radius of 25M.",1010.0759v2
2010-11-13,Photon shell game in three-resonator circuit quantum electrodynamics,"The generation and control of quantum states of light constitute fundamental
tasks in cavity quantum electrodynamics (QED). The superconducting realization
of cavity QED, circuit QED, enables on-chip microwave photonics, where
superconducting qubits control and measure individual photon states. A
long-standing issue in cavity QED is the coherent transfer of photons between
two or more resonators. Here, we use circuit QED to implement a three-resonator
architecture on a single chip, where the resonators are interconnected by two
superconducting phase qubits. We use this circuit to shuffle one- and
two-photon Fock states between the three resonators, and demonstrate
qubit-mediated vacuum Rabi swaps between two resonators. This illustrates the
potential for using multi-resonator circuits as photon quantum registries and
for creating multipartite entanglement between delocalized bosonic modes.",1011.3080v3
2011-01-04,Hybridization effect in coupled metamaterials,"Although the invention of the metamaterials has stimulated the interest of
many researchers and possesses many important applications, the basic design
idea is very simple: composing effective media from many small structured
elements and controlling its artificial EM properties. According to the
effective-media model, the coupling interactions between the elements in
metamaterials are somewhat ignored; therefore, the effective properties of
metamaterials can be viewed as the ""averaged effect"" of the resonance property
of the individual elements. However, the coupling interaction between elements
should always exist when they are arranged into metamaterials. Sometimes,
especially when the elements are very close, this coupling effect is not
negligible and will have a substantial effect on the metamaterials' properties.
In recent years, it has been shown that the interaction between resonance
elements in metamaterials could lead to some novel phenomena and interesting
applications that do not exist in conventional uncoupled metamaterials. In this
paper, we will give a review of these recent developments in coupled
metamaterials. For the ""meta-molecule"" composed of several identical
resonators, the coupling between these units produces multiple discrete
resonance modes due to hybridization. In the case of a ""meta-crystal""
comprising an infinite number of resonators, these multiple discrete resonances
can be extended to form a continuous frequency band by strong coupling. This
kind of broadband and tunable coupled metamaterial may have interesting
applications. Many novel metamaterials and nanophotonic devices could be
developed from coupled resonator systems in the future.",1101.0732v1
2011-04-11,Resonance index and singular spectral shift function,"This paper is a continuation of my previous work on absolutely continuous and
singular spectral shift functions, where it was in particular proved that the
singular part of the spectral shift function is an a.e. integer-valued
function. It was also shown that the singular spectral shift function is a
locally constant function of the coupling constant $r,$ with possible jumps
only at resonance points. Main result of this paper asserts that the jump of
the singular spectral shift function at a resonance point is equal to the
so-called resonance index, --- a new (to the best of my knowledge) notion
introduced in this paper.
  Resonance index can be described as follows. For a fixed $\lambda$ the
resonance points $r_0$ of a path $H_r$ of self-adjoint operators are real poles
of a certain meromorphic function associated with the triple $(\lambda+i0;
H_0,V).$ When $\lambda+i0$ is shifted to $\lambda+iy$ with small $y>0,$ that
pole get off the real axis in the coupling constant complex plane and, in
general, splits into some $N_+$ poles in the upper half-plane and some $N_-$
poles in the lower half-plane (counting multiplicities). Resonance index of the
triple $(\lambda; H_{r_0},V)$ is the difference $N_+-N_-.$
  Based on the theorem just described, a non-trivial example of singular
spectral shift function is given.",1104.1903v1
2011-05-24,Asymptotic and numerical studies of resonant tunneling in 2D quantum waveguides of variable cross-section,"A waveguide coincides with a strip having two narrows of diameter $\epsilon$.
Electron motion is described by the Helmholtz equation with Dirichlet boundary
condition. The part of waveguide between the narrows plays the role of
resonator and there can occur electron resonant tunneling. This phenomenon
consists in the fact that, for an electron with energy $E$, the probability
$T(E)$ to pass from one part of the waveguide to the other part through the
resonator has a sharp peak at $E=E_{res}$, where $E_{res}$ denotes a ""resonant""
energy. In the present paper, we compare the asymptotics of
$E_{res}=E_{res}(\epsilon)$ and $T(E)=T(E, \epsilon)$ as $\epsilon \to 0$ with
the corresponding numerical results obtained by approximate computing the
waveguide scattering matrix. We show that there exists a band of $\epsilon$
where the asymptotics and numerical results are in close agreement. The
numerical calculations become inefficient as $\epsilon$ decreases; however, at
such a condition the asymptotics remains reliable. On the other hand, the
asymptotics gives way to the numerical method as $\epsilon$ increases; in fact,
for wide narrows the resonant tunneling vanishes by itself.
  Though, in the present paper, we consider only a 2D waveguide, the
applicability of the methods goes far beyond the above simplest model. In
particular, the same approach will work for asymptotic and numerical analysis
of resonant tunneling in 3D quantum waveguides.",1105.4860v1
2011-05-26,Resonant Auger decay of the core-excited C$^\ast$O molecule in intense X-ray laser fields,"The dynamics of the resonant Auger (RA) process of the core-excited
C$^\ast$O(1s$^{-1}\pi^\ast,v_r=0$) molecule in an intense X-ray laser field is
studied theoretically. The theoretical approach includes the analogue of the
conical intersections of the complex potential energy surfaces of the ground
and `dressed' resonant states due to intense X-ray pulses, taking into account
the decay of the resonance and the direct photoionization of the ground state,
both populating the same final ionic states coherently, as well as the direct
photoionization of the resonance state itself. The light-induced non-adiabatic
effect of the analogue of the conical intersections of the resulting complex
potential energy surfaces gives rise to strong coupling between the electronic,
vibrational and rotational degrees of freedom of the diatomic CO molecule. The
interplay of the direct photoionization of the ground state and of the decay of
the resonance increases dramatically with the field intensity. The coherent
population of a final ionic state via both the direct photoionization and the
resonant Auger decay channels induces strong interference effects with distinct
patterns in the RA electron spectra. The individual impact of these physical
processes on the total electron yield and on the CO$^+(A^2\Pi)$ electron
spectrum are demonstrated.",1105.5374v2
2011-07-26,Triangulating tunneling resonances in a point contact,"We observe resonant tunneling in silicon split gate point contacts implanted
with antimony and defined in a self-aligned poly-silicon double gate
enhancement mode Si-MOS device structure. We identify which resonances are
likely candidates for transport through the antimony donor as opposed to
unintentional disorder induced potentials using capacitance triangulation. We
determine the capacitances from the resonant feature to each of the conducting
gates and the source/drain two dimensional electron gas regions. In our device
geometry, these capacitances provide information about the resonance location
in three dimensions. Semi-classical electrostatic simulations of capacitance,
already used to map quantum dot size and position, identify a combination of
location and confinement potential size that satisfy our experimental
observations. The sensitivity of simulation to position and size allow us to
triangulate possible locations of the resonant level with nanometer resolution.
We discuss our results and how they may apply to resonant tunneling through a
single donor.",1107.5104v1
2011-07-28,Discovery in Drell-Yan Processes at the LHC,"We study the Drell-Yan process mediated by a new bosonic resonance at the
LHC. The bosons of spin-0, 1, and 2 with the most general leading-order
couplings to Standard Model fermions and gluons are considered, which provide a
model-independent formulation for future exploration of the resonance
properties, such as its spin, mass and couplings. In the case of neutral
resonances, we demonstrate how the shapes of the kinematical distributions
change as one varies the chiral couplings of the quarks and leptons, and show
how to analyze the couplings by making use of the forward-backward asymmetry.
In the case of charged resonances, we propose a novel technique to effectively
reconstruct the angular distribution in the center-of-mass frame, to a large
extent avoiding the two-fold ambiguity due to the missing neutrino. Similar to
the case of a neutral resonance, the spin information of the resonance can be
extracted unambiguously, and chiral couplings and the asymmetries can be
explored in a statistical manner. With the current LHC data, we present bounds
on the mass and cross section times branching fraction of the new resonance and
estimate the future reach.",1107.5830v1
2011-08-01,"Effect of nodes, ellipticity and impurities on the spin resonance in Iron-based superconductors","We analyze doping dependence of the spin resonance of an s+- superconductor
and its sensitivity to the ellipticity of electron pockets, to magnetic and
non-magnetic impurities, and to the angle dependence of the superconducting gap
along electron Fermi surfaces. We show that the maximum intensity of the
resonance shifts from commensurate to incommensurate momentum above some
critical doping which decreases with increasing ellipticity. Angle dependence
of the gap and particularly the presence of accidental nodes lowers the overall
intensity of the resonance peak and shifts its position towards the onset of
the particle-hole continuum. Still, however, the resonance remains a true
\delta-function in the clean limit. When non-magnetic or magnetic impurities
are present, the resonance broadens and its position shifts. The shift depends
on the type of impurities and on the ratio of intraband and interband
scattering components. The ratio Omega_{res}/T_c increases almost linearly with
the strength of the interband impurity scattering, in agreement with the
experimental data. We also compare spin response of s+- and s++
superconductors. We show that there is no resonance for s++ gap, even when
there is a finite mismatch between electron and hole Fermi surfaces shifted by
the antiferromagnetic momentum.",1108.0266v1
2011-10-18,Signatures of low-scale string models at the LHC,"Low-scale string models, in which the string scale M_s is of the order of TeV
with large extra dimensions, can solve the problems of scale hierarchy and
non-renormalizable quantum gravity in the standard model. String excited states
of the standard model particles are possibly observed as resonances in the
dijet invariant mass distribution at the LHC. There are two properties to
distinguish whether the resonances are due to low-scale string or some other
""new physics"". One is a characteristic angular distribution in dijet events at
the resonance due to spin degeneracy of string excited states, and the other is
an appearance of the second resonance at a characteristic mass of second string
excited states. We investigate a possibility to observe these evidences of
low-scale string models by Monte Carlo simulations with a reference value of
M_s = 4 TeV at sqrt{s} = 14 TeV. It is shown that spin degeneracy at the dijet
resonance can be observed by looking the chi-distribution with integrated
luminosity of 20 fb^-1. It is shown that the second resonance can be observed
at rather close to the first resonance in the dijet invariant mass distribution
with integrated luminosity of 50 fb^-1. These are inevitable signatures of
low-scale string models.",1110.3976v4
2012-06-25,Crosstalk Reduction for Superconducting Microwave Resonator Arrays,"Large-scale arrays of Microwave Kinetic Inductance Detectors (MKIDs) are
attractive candidates for use in imaging instruments for next generation
submillimeter-wave telescopes such as CCAT. We have designed and fabricated
tightly packed ~250-pixel MKID arrays using lumped-element resonators etched
from a thin layer of superconducting TiNx deposited on a silicon substrate. The
high pixel packing density in our initial design resulted in large microwave
crosstalk due to electromagnetic coupling between the resonators. Our second
design eliminates this problem by adding a grounding shield and using a
double-wound geometry for the meander inductor to allow conductors with
opposite polarity to be in close proximity. In addition, the resonator
frequencies are distributed in a checkerboard pattern across the array. We
present details for the two resonator and array designs and describe a circuit
model for the full array that predicts the distribution of resonator
frequencies and the crosstalk level. We also show results from a new
experimental technique that conveniently measures crosstalk without the need
for an optical setup. Our results reveal an improvement in crosstalk from 57%
in the initial design down to \leq 2% in the second design. The general
procedure and design guidelines in this work are applicable to future large
arrays employing microwave resonators.",1206.5571v1
2012-07-04,Bandwidth-Limited Control and Ringdown Suppression in High-Q Resonators,"We describe how the transient behavior of a tuned and matched resonator
circuit and a ringdown suppression pulse may be integrated into an optimal
control theory (OCT) pulse-design algorithm to derive control sequences with
limited ringdown that perform a desired quantum operation in the presence of
resonator distortions of the ideal waveform. Inclusion of ringdown suppression
in numerical pulse optimizations significantly reduces spectrometer deadtime
when using high quality factor (high-Q) resonators, leading to increased
signal-to-noise ratio (SNR) and sensitivity of inductive measurements. To
demonstrate the method, we experimentally measure the free-induction decay of
an inhomogeneously broadened solid-state free radical spin system at high Q.
The measurement is enabled by using a numerically optimized bandwidth-limited
OCT pulse, including ringdown suppression, robust to variations in static and
microwave field strengths. We also discuss the applications of pulse design in
high-Q resonators to universal control of anisotropic-hyperfine coupled
electron-nuclear spin systems via electron-only modulation even when the
bandwidth of the resonator is significantly smaller than the hyperfine coupling
strength. These results demonstrate how limitations imposed by linear response
theory may be vastly exceeded when using a sufficiently accurate system model
to optimize pulses of high complexity.",1207.1139v2
2012-07-05,Bound and resonant impurity states in a narrow gaped armchair graphene nanoribbon,"An analytical study of discrete and resonant impurity quasi-Coulomb states in
a narrow gaped armchair graphene nanoribbon (GNR) is performed. We employ the
adiabatic approximation assuming that the motions parallel (""slow"") and
perpendicular (""fast"") to the boundaries of the ribbon are separated
adiabatically. The energy spectrum comprises a sequence of series of
quasi-Rydberg levels relevant to the ""slow"" motion adjacent from the low
energies to the size-quantized levels associated with the ""fast"" motion. Only
the series attributed to the ground size-quantized sub-band is really discrete,
while others corresponding to the excited sub-bands consist of quasi-discrete
(Fano resonant) levels of non-zero energetic widths, caused by the coupling
with the states of the continuous spectrum branching from the low lying
sub-bands. In the two- and three-subband approximation the spectrum of the
complex energies of the impurity electron is derived in an explicit form.
Narrowing the GNR leads to an increase of the binding energy and the resonant
width both induced by the finite width of the ribbon. Displacing the impurity
centre from the mid-point of the GNR causes the binding energy to decrease
while the resonant width of the first excited Rydberg series increases. As for
the second excited series their widths become narrower with the shift of the
impurity. A successful comparison of our analytical results with those obtained
by other theoretical and experimental methods is presented. Estimates of the
binding energies and the resonant widths taken for the parameters of typical
GNRs show that not only the strictly discrete but also the some resonant states
are quite stable and could be studied experimentally in doped GNRs.",1207.1260v1
2012-11-23,Planets Near Mean-Motion Resonances,"The multiple-planet systems discovered by the Kepler mission exhibit the
following feature: planet pairs near first-order mean-motion resonances prefer
orbits just outside the nominal resonance, while avoiding those just inside the
resonance. We explore an extremely simple dynamical model for planet formation,
in which planets grow in mass at a prescribed rate without orbital migration or
dissipation. We develop an analytic version of this model for two-planet
systems in two limiting cases: the planet mass grows quickly or slowly relative
to the characteristic resonant libration time. In both cases the distribution
of systems in period ratio develops a characteristic asymmetric peak-trough
structure around the resonance, qualitatively similar to that observed in the
Kepler sample. We verify this result with numerical integrations of the
restricted three-body problem. We show that for the 3:2 resonance, where the
observed peak-trough structure is strongest, our simple model is consistent
with the observations for a range of mean planet masses 20-100M_{\oplus}. This
mass range is higher than expected, by at least a factor of three, from the few
Kepler planets with measured masses, but part of this discrepancy could be due
to oversimplifications in the dynamical model or uncertainties in the planetary
mass-radius relation.",1211.5603v1
2013-01-12,Time-Integrated Luminosity Recorded by the BABAR Detector at the PEP-II e+e- Collider,"We describe a measurement of the time-integrated luminosity of the data
collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider
at the Upsilon(4S), Upsilon(3S) and Upsilon(2S) resonances and in a continuum
region below each resonance. We measure the time-integrated luminosity by
counting e+e- --> e+e- and (for the Upsilon(4S) only) e+e- --> mu+mu- candidate
events, allowing additional photons in the final state. We use data-corrected
simulation to determine the cross sections and reconstruction efficiencies for
these processes, as well as the major backgrounds. Due to the large cross
sections of e+e- --> e+e- and e+e- --> mu+mu-, the statistical uncertainties of
the measurement are substantially smaller than the systematic uncertainties.
The dominant systematic uncertainties are due to observed differences between
data and simulation, as well as uncertainties on the cross sections. For data
collected on the Upsilon(3S) and Upsilon(2S) resonances, an additional
uncertainty arises due to Upsilon --> e+e-X background. For data collected off
the Upsilon resonances, we estimate an additional uncertainty due to
time-dependent efficiency variations, which can affect the short off-resonance
runs. The relative uncertainties on the luminosities of the on-resonance
(off-resonance) samples are 0.43% (0.43%) for the Upsilon(4S), 0.58% (0.72%)
for the Upsilon(3S), and 0.68% (0.88%) for the Upsilon(2S).",1301.2703v3
2013-01-14,Detection of Laplace-resonant three-planet systems from transit timing variations,"Transit timing variations (TTVs) are useful to constrain the existence of
perturbing planets, especially in resonant systems where the variations are
strongly enhanced. Here we focus on Laplace-resonant three-planet systems, and
assume the inner planet transits the star. A dynamical study is performed for
different masses of the three bodies, with a special attention to terrestrial
planets. We consider a maximal time-span of ~ 100 years and discuss the shape
of the inner planet TTVs curve. Using frequency analysis, we highlight the
three periods related to the evolution of the system: two periods associated
with the Laplace-resonant angle and the third one with the precession of the
pericenters. These three periods are clearly detected in the TTVs of an inner
giant planet perturbed by two terrestrial companions. Only two periods are
detected for a Jupiter-Jupiter-Earth configuration (the ones associated with
the giant interactions) or for three terrestrial planets (the Laplace periods).
However, the latter system can be constrained from the inner planet TTVs. We
finally remark that the TTVs of resonant three or two Jupiter systems mix up,
when the period of the Laplace resonant angle matches the pericenter precession
of the two-body configuration. This study highlights the importance of TTVs
long-term observational programs for the detection of multiple-planet resonant
systems.",1301.2891v1
2013-02-04,Decoupling Crossover in Asymmetric Broadside Coupled Split Ring Resonators at Terahertz Frequencies,"We investigate the electromagnetic response of asymmetric broadside coupled
split ring resonators (ABC-SRRs) as a function of the relative in-plane
displacement between the two component SRRs. The asymmetry is defined as the
difference in the capacitive gap widths (\Delta g) between the two resonators
comprising a coupled unit. We characterize the response of ABC-SRRs both
numerically and experimentally via terahertz time-domain spectroscopy. As with
symmetric BC-SRRs (\Delta g=0 \mu m), a large redshift in the LC resonance is
observed with increasing displacement, resulting from changes in the capacitive
and inductive coupling. However, for ABC-SRRs, in-plane shifting between the
two resonators by more than 0.375Lo (Lo=SRR sidelength) results in a transition
to a response with two resonant modes, associated with decoupling in the
ABC-SRRs. For increasing \Delta g, the decoupling transition begins at the same
relative shift (0.375Lo), though with an increase in the oscillator strength of
the new mode. This strongly contrasts with symmetric BC-SRRs which present only
one resonance for shifts up to 0.75Lo. Since all BC-SRRs are effectively
asymmetric when placed on a substrate, an understanding of ABC-SRR behavior is
essential for a complete understanding of BC-SRR based metamaterials.",1302.0782v1
2013-02-08,Raman and non Raman EIT resonances in a degenerate four level system,"We study coherence effects in an atom having three metastable levels and
single life-time broadened upper state. Two laser fields couple ground states
to an excited one and an radio-frequency (rf) field operates between ground
state levels. We consider the case when the common level for the rf-field and
one of the laser field (to which we refer as the probing field) transitions is
twice degenerate. We predict a novel type of dark states (we call them non
Raman dark states), which in contrary to Raman resonances, do not require the
fulfillment of the two-photon resonance condition. We realize the configuration
in the atomic hydrogen and show that non Raman resonances are determined by the
geometry of the rf and probing field's polarizations. For ultra-cold atoms non
Raman resonances arise when the polarization vectors of the fields are parallel
or perpendicular to each other. For an atomic gas at room temperatures
electromagnetically induced transparency (EIT) resonances associated with Raman
and non Raman dark states are studied by taking into account spin-exchange
relaxation in the ground state of the hydrogen atom. We establish properties of
non Raman dark states by investigating the relation of EIT resonances to the
polarization geometry.",1302.1976v2
2013-04-22,Origin Scenarios for the Kepler 36 Planetary System,"We explore scenarios for the origin of two different density planets in the
Kepler 36 system in adjacent orbits near the 7:6 mean motion resonance. We find
that fine tuning is required in the stochastic forcing amplitude, the migration
rate and planet eccentricities to allow two convergently migrating planets to
bypass mean motion resonances such as the 4:3, 5:4 and 6:5, and yet allow
capture into the 7:6 resonance. Stochastic forcing can eject the system from
resonance causing a collision between the planets, unless the disk inducing
migration and stochastic forcing is depleted soon after resonance capture.
  We explore a scenario with approximately Mars mass embryos originating
exterior to the two planets and migrating inwards toward two planets. We find
that gravitational interactions with embryos can nudge the system out of
resonances. Numerical integrations with about a half dozen embryos can leave
the two planets in the 7:6 resonance. Collisions between planets and embryos
have a wide distribution of impact angles and velocities ranging from
accretionary to disruptive. We find that impacts can occur at sufficiently high
impact angle and velocity that the envelope of a planet could have been
stripped, leaving behind a dense core. Some of our integrations show the two
planets exchanging locations, allowing the outer planet that had experienced
multiple collisions with embryos to become the innermost planet. A scenario
involving gravitational interactions and collisions with embryos may account
for both the proximity of the Kepler 36 planets and their large density
contrast.",1304.6124v3
2013-05-12,Interplay between out-of-plane magnetic plasmon and lattice resonance for modified resonance lineshape and near-field enhancement in double nanoparticles array,"Two-dimensional double nanoparticles (DNPs) arrays are demonstrated
theoretically supporting the interaction of out-of-plane magnetic plasmons and
in-plane lattice resonances, which can be achieved by tuning the nanoparticle
height or the array period due to the height-dependent magnetic resonance and
the periodicity-dependent lattice resonance. The interplay of the two plasmon
modes can lead to a remarkable change in resonance lineshape and an improvement
of magnetic field enhancement. Simultaneous electric field and magnetic field
enhancements can be obtained in the gap regions between neighboring particles
at two resonance frequencies as the interplay occurs, which present open
cavities as electromagnetic field hot spots for potential applications on
detection and sensing. The results not only offer an attractive way to tune the
optical responses of plasmonic nanostructure, but also provide further insight
into the plasmons interactions in periodic nanostructure or metamaterials
comprising multiple elements.",1305.2558v1
2013-05-18,Inductively coupled superconducting half wavelength resonators as persistent current traps for ultracold atoms,"A crucial point in the experimental implementation of hybrid quantum systems
consisting of superconducting circuits and atomic ensembles is bringing the two
partners close enough to each other that a strong quantum coherent coupling can
be established. Here, we propose to use the metallization structures of a half
wavelength superconducting coplanar waveguide resonator as a persistent current
trap for ultracold paramagnetic atoms. Trapping atoms with the resonator
structure itself is provided by using short-ended and inductively coupled
resonators instead of capacitively coupled ones as customary in circuit quantum
electrodynamics.We analyze the external quality factor of short-ended coplanar
waveguide resonators and show that it can be easily designed for the desired
regime of quantum circuits. The magnetic field configuration at the resonator
is calculated by means of numerical three-dimensional simulations of the London
equations. We present a way to transport an atomic ensemble into the coplanar
resonator gap where the magnetic field of the cavity mode is maximum. The
configuration allows stable trapping by persistent currents and paves the route
towards strong coupling between atomic clouds and the cavity mode which is
required for cooperative effects and gives the interface between atoms and
circuit quantum electrodynamics.",1305.4249v1
2013-06-16,Zero-Field Fiske Resonance Coupled with Spin-waves in Ferromagnetic Josephson Junctions,"AC Josephson current density in a Josephson junction with DC bias is
spatially modulated by an external magnetic field, and induces an
electromagnetic (EM) field inside the junction. The current-voltage ($I$-$V$)
curve exhibits peaks due to the resonance between the EM field and the
spatially modulated AC Josephson current density. This is called {\it Fiske
resonance}. Such a spatially modulated Josephson current density can be also
induced by a non-uniform insulating barrier and the Fiske resonance appears
without external magnetic field. This is called zero-field Fiske resonance
(ZFFR). In this paper, we theoretically study the ZFFR coupled with spin-waves
in a superconductor/ferromagnetic insulator/superconductor junction
(ferromagnetic Josephson junction) with a non-uniform ferromagnetic insulating
barrier. The resonant mode coupled with spin-waves can be induced without
external magnetic field. We find that the $I$-$V$ curve shows resonant peaks
associated with composite excitations of spin-waves and the EM field in the
junction. The voltage at the resonance is obtained as a function of the normal
modes of EM field. The ZFFRs coupled with spin-waves are found as peak
structures in the DC Josephson current density as a function of bias voltage.",1306.3652v2
2013-11-22,Elastodynamics and resonances in elliptical geometry,"The resonant modes of two-dimensional elastic elliptical objects are studied
from a modal formalism by emphasizing the role of the symmetries of the
objects. More precisely, as the symmetry is broken in the transition from the
circular disc to the elliptical one, the splitting up of resonances and level
crossings are observed. From the mathematical point of view, this observation
can be explained by the broken invariance of the continuous symmetry group O(2)
associated with the circular disc. The elliptical disc is however invariant
under the finite group C2v and the resonances are classified and associated
with a given irreducible representation of this group. The main difficulty
arises in the application of the group theory in elastodynamics where the
vectorial formalism is used to express the physical quantities (elastic
displacement and stress) involved in the boundary conditions. However, this
method significantly simplifies the numerical treatment of the problem which is
uncoupled over the four irreducible representations of C2v. This provides a
full classification of the resonances. They are tagged and tracked as the
eccentricity of the elliptical disc increases. Then, the splitting up of
resonances, which occurs in the transition from the circular disc to the
elliptic one, is emphasized. The computation of displacement normal modes also
highlights the mode splittings. A physical interpretation of resonances in
terms of geometrical paths is provided.",1311.5805v1
2013-12-07,How the presence of a gas giant affects the formation of mean-motion resonances between two low-mass planets in a locally isothermal gaseous disc,"In this paper we investigate the possibility of a migration-induced resonance
locking in systems containing three planets, namely an Earth analog, a
super-Earth and a gas giant. The planets have been listed in order of
increasing orbital periods. All three bodies are embedded in a locally
isothermal gaseous disc and orbit around a solar mass star. We are interested
in answering the following question: Will the low-mass planets form the same
resonant structures with each other in the vicinity of the gas giant as in the
case when the gas giant is absent? When there is no gas giant in the system, it
has been already shown that if the two low-mass planets undergo a convergent
differential migration, they will capture each other in a mean-motion
resonance. For the choices of disc parameters and planet masses made in this
paper, the formation of the 5:4 resonance in the absence of the Jupiter has
been observed. In this work we add a gas giant on the most external orbit of
the system in such a way that its differential migration is convergent with the
low-mass planets. We show that the result of this set-up is the speeding up of
the migration of the super-Earth and, after that, all three planets become
locked in a triple mean-motion resonance. However, this resonance is not
maintained due to the low-mass planet eccentricity excitation, a fact that
leads to close encounters between planets and eventually to the ejection from
the internal orbits of one or both low-mass planets.",1312.2147v1
2013-12-11,Algorithm for spectral response analysis of superconducting microwave transmission-line resonator,"It has always been a challenge for researchers to efficiently and accurately
post process experimental data which is distorted by the noise. Superconducting
microwave devices e.g. resonators, directional filters, beam-splitters etc.
operate at frequency of several GHz to THz and temperatures well below critical
temperature (Tc) with few exceptions like transition edge sensors where devices
are operated at temperatures close to Tc. These devices are measured usually
with vector network analyser in terms of scattering parameters. Two kinds of
errors, systematic and drift can easily be removed from the measurements taken
with VNA. However, random errors are not easy to address and remove due to
their unpredictability and randomness. In this manuscript we will present an
algorithm to post process experimental data to cope with measurements that have
been corrupted or useful spectral response is buried in spurious signal. We
have developed a robust and efficient algorithm, implemented in MATLAB, to
detect peaks in spectral response, remove baseline and finally estimate
parameters of two-port superconductor resonator using an Improved Nelder-Mead
Method for unconstrained multidimensional least square minimization. The
algorithm has been successfully tested and verified by processing spectral
response of half wavelength microwave transmission-line resonator successfully
isolating resonator response from noisy background. We were able to compute
loaded quality factor, resonance frequency from response data with high
reproducibility even from those experimental data sets where resonance spikes
were hardly visible.",1312.3145v1
2014-02-17,Harmonic inversion analysis of exceptional points in resonance spectra,"The spectra of, e.g. open quantum systems are typically given as the
superposition of resonances with a Lorentzian line shape, where each resonance
is related to a simple pole in the complex energy domain. However, at
exceptional points two or more resonances are degenerate and the resulting
non-Lorentzian line shapes are related to higher order poles in the complex
energy domain. In the Fourier-transform time domain an $n$-th order exceptional
point is characterised by a non-exponentially decaying time signal given as the
product of an exponential function and a polynomial of degree $n-1$. The
complex positions and amplitudes of the non-degenerate resonances can be
determined with high accuracy by application of the nonlinear harmonic
inversion method to the real-valued resonance spectra. We extend the harmonic
inversion method to include the analysis of exceptional points. The technique
yields, in the energy domain, the amplitudes of the higher order poles
contributing to the spectra, and, in the time domain, the coefficients of the
polynomial characterising the non-exponential decay of the time signal. The
extended harmonic inversion method is demonstrated on two examples, viz. the
analysis of exceptional points in resonance spectra of the hydrogen atom in
crossed magnetic and electric fields, and an exceptional point occurring in the
dynamics of a single particle in a time-dependent harmonic trap.",1402.4032v1
2014-07-30,Cloaking via anomalous localized resonance for doubly complementary media in the quasistatic regime,"This paper is devoted to the study of cloaking via anomalous localized
resonance (CALR) in the two and three dimensional quasistatic regimes. CALR
associated with negative index materials was discovered by Milton and
Nicorovicci in [21] and attracted a lot attention in the scientific community.
Two key figures of this phenomenon are the localized resonance, i.e., the
fields blow up in some regions and remain bounded in some others, and the
connection between the localized resonance and the blow up of the power of the
fields as the loss goes to 0. An important class of negative index materials
for which the localized resonance might appear is the class of reflecting
complementary media introduced in [24]. It was showed in [29] that
complementary property of media is not enough to ensure a connection between
the blow up of the power and the localized resonance. In this paper, we study
CALR for a subclass of complementary media called the class of doubly
complementary media. This class is rich enough to allow us to cloak an
arbitrary source concentrating on an arbitrary smooth bounded manifold of
codimension 1 placed in an arbitrary medium via anomalous localized resonance.
The following three properties are established for doubly complementary media:
1) CALR appears if and only if the power blows up; 2) The power blows up if the
source is near the plasmonic structure; 3) The power remains bounded if the
source is far away from the plasmonic structure. Property 2), the blow up of
the power, is in fact established for reflecting complementary media...",1407.7977v3
2014-08-22,Energy-dependent resonance broadening in symmetric and asymmetric molecular junctions from an ab initio non-equilibrium Green's function approach,"The electronic structure of organic-inorganic interfaces often feature
resonances originating from discrete molecular orbitals coupled to continuum
lead states. An example are molecular junctions, individual molecules bridging
electrodes, where the shape and peak energy of such resonances dictate junction
conductance, thermopower, I-V characteristics and related transport properties.
In molecular junctions where off-resonance coherent tunneling dominates
transport, resonance peaks in the transmission function are often assumed to be
Lorentzian functions with an energy-independent broadening parameter $\Gamma$.
Here we define a new energy-dependent resonance broadening function,
$\Gamma(E)$, based on diagonalization of non-Hermitian matrices, which can
describe resonances of a more complex, non-Lorentzian nature and can be
decomposed into components associated with the left and right lead,
respectively. We compute this quantity via an \emph{ab initio} non-equilibrium
Green's function approach based on density functional theory for both symmetric
and asymmetric molecular junctions, and show that our definition of
$\Gamma(E)$, when combined with Breit-Wigner formula, reproduces the
transmission calculated from DFT-NEGF. Through a series of examples, we
illustrate how this approach can shed new light on experiments and
understanding of junction transport properties in terms of molecular orbitals.",1408.5183v1
2014-08-25,Disentangling the Spin-Parity of a Resonance via the Gold-Plated Decay Mode,"Searching for new resonances and finding out their properties is an essential
part of any existing or future particle physics experiment. The nature of a new
resonance is characterized by its spin, charge conjugation, parity, and its
couplings with the existing particles of the Standard Model. If a new resonance
is found in the four lepton final state produced via two intermediate $Z$
bosons, the resonance could be a new heavy scalar or a $Z'$ boson or even a
higher spin particle. In such cases the step by step methodology as enunciated
in this paper can be followed to determine the spin, parity and the coupling to
two $Z$ bosons of the parent particles, in a fully model-independent way. In
our approach we show how three uni-angular distributions and few experimentally
measurable observables can conclusively tell us about the spin, parity as well
as the couplings of the new resonance to two $Z$ bosons. We have performed a
numerical analysis to validate our approach and showed how the uniangular
observables can be used to disentangle the spin parity as well as coupling of
the resonance.",1408.5665v2
2014-10-02,Outward migration of Jupiter and Saturn in 3:2 or 2:1 resonance in radiative disks: implications for the Grand Tack and Nice models,"Embedded in the gaseous protoplanetary disk, Jupiter and Saturn naturally
become trapped in 3:2 resonance and migrate outward. This serves as the basis
of the Grand Tack model. However, previous hydrodynamical simulations were
restricted to isothermal disks, with moderate aspect ratio and viscosity. Here
we simulate the orbital evolution of the gas giants in disks with viscous
heating and radiative cooling. We find that Jupiter and Saturn migrate outward
in 3:2 resonance in modest-mass ($M_{disk} \approx M_{MMSN}$, where MMSN is the
""minimum-mass solar nebula"") disks with viscous stress parameter $\alpha$
between $10^{-3}$ and $10^{-2} $. In disks with relatively low-mass ($M_{disk}
\lesssim M_{MMSN}$) , Jupiter and Saturn get captured in 2:1 resonance and can
even migrate outward in low-viscosity disks ($\alpha \le 10^{-4}$). Such disks
have a very small aspect ratio ($h\sim 0.02-0.03$) that favors outward
migration after capture in 2:1 resonance, as confirmed by isothermal runs which
resulted in a similar outcome for $h \sim 0.02$ and $\alpha \le 10^{-4}$. We
also performed N-body runs of the outer Solar System starting from the results
of our hydrodynamical simulations and including 2-3 ice giants. After dispersal
of the gaseous disk, a Nice model instability starting with Jupiter and Saturn
in 2:1 resonance results in good Solar Systems analogs. We conclude that in a
cold Solar Nebula, the 2:1 resonance between Jupiter and Saturn can lead to
outward migration of the system, and this may represent an alternative scenario
for the evolution of the Solar System.",1410.0543v1
2014-11-20,Optimized pulse shapes for a resonator-induced phase gate,"The resonator-induced phase gate is a multi-qubit controlled-phase gate for
fixed-frequency superconducting qubits. Through off-resonant driving of a bus
resonator, statically coupled qubits acquire a state-dependent phase. However,
photon loss leads to dephasing during the gate, and any residual entanglement
between the resonator and qubits after the gate leads to decoherence. Here we
consider how to shape the drive pulse to minimize these unwanted effects.
First, we review how the gate's entangling and dephasing rates depend on the
system parameters and validate closed-form solutions against direct numerical
solution of a master equation. Next, we propose spline pulse shapes that reduce
residual qubit-bus entanglement, are robust to imprecise knowledge of the
resonator shift, and can be shortened by using higher-degree polynomials.
Finally, we present a procedure that optimizes over the subspace of pulses that
leave the resonator unpopulated. This finds shaped drive pulses that further
reduce the gate duration. Assuming realistic parameters, we exhibit shaped
pulses that have the potential to realize ~212 ns spline pulse gates and ~120
ns optimized gates with ~6e-4 average gate infidelity. These examples do not
represent fundamental limits of the gate and in principle even shorter gates
may be achievable.",1411.5436v2
2014-12-09,Distinguishing Di-jet Resonances at the LHC,"Anticipating that a di-jet resonance could be discovered at the 14 TeV LHC,
we present two different strategies to reveal the nature of such a particle; in
particular to discern whether it is a quark-antiquark (qqbar), quark-gluon
(qg), or gluon-gluon (gg) resonance. The first method relies on the color
discriminant variable, which can be calculated at the LHC from the measurements
of the di-jet signal cross section, the resonance mass and the resonance width.
Including estimated statistical uncertainties and experimental resolution, we
show that a qg excited quark resonance can be efficiently distinguished from
either a qqbar coloron or a gg color-octet scalar using the color discriminant
variable at LHC-14. The second strategy is based on the study of the energy
profiles of the two leading jets in the di-jet channel. Including statistical
uncertainties in the signal and the QCD backgrounds, we show that one can
distinguish, in a model-independent way, between gg, qg, and qqbar resonances;
an evaluation of systematic uncertainties in the measurement of the jet energy
profile will require a detailed detector study once sufficient 14 TeV di-jet
data is in hand.",1412.3094v3
2014-12-30,Existence of Nontrivial Negative Resonances for Polynomial Ordinary Differential Equations With Painlevé Property,"The Painlev\'e classification is one of the central problems in analytics
theory of differential equations rooted in the XIX century. Although it saw
many significant advances in analyzing certain classes of equations, the
classification still remains an open problem especially for the higher-order
equations. One of the main classical methods of Painlev\'e analysis is based on
considering the resonance numbers corresponding to the possible indices of
arbitrary coefficients in the Laurent expansion of the general solution in a
neighborhood of a movable singularity. Complex and non-integer values of
resonance numbers point out to existence of the movable critical singularities
and positive integer numbers could be used to construct the said general
solution. Also the equation always possesses at least one negative resonance
number of $-1$ which corresponds to an arbitrary position of a movable pole.
However our understanding of the role of nontrivial negative resonances
different from $-1$ remains limited in spite of certain recent methodological
advances related to it. And though in the lower-order classifications built so
far such equations with nontrivial negative resonances have rather been a
special case, the result of present work demonstrates that negative resonances
are in fact common for the higher degree ordinary differential equations with
Painlev\'e property. Specifically we'll prove that their presence is the
necessary condition of the Painlev\'e property for the equations with degree of
the leading terms higher than two.",1412.8761v1
2015-01-24,"A method for accurate electron-atom resonances: The complex-scaled multiconfigurational spin-tensor electron propagator method for the $^2P\, \mbox{Be}^{-}$ shape resonance problem","We propose and develop the complex scaled multiconfigurational spin-tensor
electron propagator (CMCSTEP) technique for theoretical determination of
resonance parameters with electron-atom/molecule systems including open-shell
and highly correlated atoms and molecules. The multiconfigurational spin-tensor
electron propagator method (MCSTEP) developed and implemented by Yeager his
coworkers in real space gives very accurate and reliable ionization potentials
and attachment energies. The CMCSTEP method uses a complex scaled
multiconfigurational self-consistent field (CMCSCF) state as an initial state
along with a dilated Hamiltonian where all of the electronic coordinates are
scaled by a complex factor. CMCSCF was developed and applied successfully to
resonance problems earlier. We apply the CMCSTEP method to get $^2
P\,\mbox{Be}^{-}$ shape resonance parameters using $14s11p5d$, $14s14p2d$, and
$14s14p5d$ basis sets with a $2s2p3d$\,CAS. The obtained value of the resonance
parameters are compared to previous results. This is the first time CMCSTEP has
been developed and used for a resonance problem. It will be among the most
accurate and reliable techniques. Vertical ionization potentials and attachment
energies in real space are typically within $\pm 0.2\,eV$ or better of
excellent experiments and full configuration interaction calculations with a
good basis set. We expect the same sort of agreement in complex space.",1501.05987v2
2015-02-05,Contribution to the study of the resonant rotation in the Solar System,"This HDR-thesis is devoted to the study of the rotation of the natural
satellites of the giant planets and of Mercury. These bodies have a resonant
rotation. Most of the natural satellites rotate synchronously, showing the same
hemisphere to their parent planet (1:1 spin-orbit resonance). The case of
Mercury is unique since its spin rate is exactly 1.5 its mean motion (3:2
spin-orbit resonance). These two configurations are dynamical equilibria,
reached after damping of the initial rotation of the relevant bodies. Thus, the
rotation quantities are a signature of the interior, in particular of a
putative global ocean. This manuscript divides into 3 parts. The first part is
devoted to the synchronous resonance. It presents different models of rotation
from a fully rigid body to a one with a global subsurfacic ocean. We always
consider all the degrees of freedom simultaneously, using analytical and
numerical resolutions. These models are applied on Titan, Callisto, Janus,
Epimetheus, Mimas, Hyperion, and Io. The second part presents the resonant
rotation of Mercury, target of the two space missions MESSENGER and
BepiColombo. We reveal in particular how it got trapped into its 3:2 resonance.
The final part presents an algorithm I have elaborated to tackle the rotational
problems.",1502.01472v1
2015-03-18,Vector and scalar charmonium resonances with lattice QCD,"We perform an exploratory lattice QCD simulation of $D \bar D$ scattering,
aimed at determining the masses as well as the decay widths of charmonium
resonances above open charm threshold. Neglecting coupling to other channels,
the resulting phase shift for $D \bar D$ scattering in p-wave yields the
well-known vector resonance $\psi(3770)$. For $m_\pi = 156$ MeV, the extracted
resonance mass and the decay width agree with experiment within large
statistical uncertainty. The scalar charmonium resonances present a puzzle,
since only the ground state $\chi_{c0}(1P)$ is well understood, while there is
no commonly accepted candidate for its first excitation. We simulate $D \bar D$
scattering in s-wave in order to shed light on this puzzle. The resulting phase
shift supports the existence of a yet-unobserved narrow resonance with a mass
slightly below 4 GeV. A scenario with this narrow resonance and a pole at
$\chi_{c0}(1P)$ agrees with the energy-dependence of our phase shift. Further
lattice QCD simulations and experimental efforts are needed to resolve the
puzzle of the excited scalar charmonia.",1503.05363v2
2015-05-12,Tilting Jupiter (a bit) and Saturn (a lot) During Planetary Migration,"We study the effects of planetary late migration on the gas giants
obliquities. We consider the planetary instability models from Nesvorny &
Morbidelli (2012), in which the obliquities of Jupiter and Saturn can be
excited when the spin-orbit resonances occur. The most notable resonances occur
when the $s_7$ and $s_8$ frequencies, changing as a result of planetary
migration, become commensurate with the precession frequencies of Jupiter's and
Saturn's spin vectors. We show that Jupiter may have obtained its present
obliquity by crossing of the $s_8$ resonance. This would set strict constrains
on the character of migration during the early stage. Additional effects on
Jupiter's obliquity are expected during the last gasp of migration when the
$s_7$ resonance was approached. The magnitude of these effects depends on the
precise value of the Jupiter's precession constant. Saturn's large obliquity
was likely excited by capture into the $s_8$ resonance. This probably happened
during the late stage of planetary migration when the evolution of the $s_8$
frequency was very slow, and the conditions for capture into the spin-orbit
resonance with $s_8$ were satisfied. However, whether or not Saturn is in the
spin-orbit resonance with $s_8$ at the present time is not clear, because the
existing observations of Saturn's spin precession and internal structure models
have significant uncertainties.",1505.02938v1
2015-06-09,Search for resonant t t-bar production in proton-proton collisions at sqrt(s) = 8 TeV,"A search is performed for the production of heavy resonances decaying into
top-antitop quark pairs in proton-proton collisions at sqrt(s) = 8 TeV. Data
used for the analyses were collected with the CMS detector and correspond to an
integrated luminosity of 19.7 inverse femtobarns. The search is performed using
events with three different final states, defined by the number of leptons
(electrons and muons) from the t t-bar to W b W b decay. The analyses are
optimized for reconstruction of top quarks with high Lorentz boosts, where jet
substructure techniques are used to enhance the sensitivity. Results are
presented for all channels and a combination is performed. No significant
excess of events relative to the expected yield from standard model processes
is observed. Upper limits on the production cross section of heavy resonances
decaying to t t-bar are calculated. A narrow leptophobic topcolor Z' resonance
with a mass below 2.4 TeV is excluded at 95% confidence level. Limits are also
derived for a broad Z' resonance with a 10% width relative to the resonance
mass, and a Kaluza-Klein excitation of the gluon in the Randall-Sundrum model.
These are the most stringent limits to date on heavy resonances decaying into
top-antitop quark pairs.",1506.03062v2
2015-06-11,Stability of resonant configurations during the migration of planets and constraints on disk-planet interactions,"We study the stability of mean-motion resonances (MMR) between two planets
during their migration in a protoplanetary disk. We use an analytical model of
resonances, and describe the effect of the disk by a migration timescale
(T_{m,i}) and an eccentricity damping timescale (T_{e,i}) for each planet
(i=1,2 respectively for the inner and outer planet). We show that the resonant
configuration is stable if T_{e,1}/T_{e,2} > (e_1/e_2)^2. This general result
can be used to put constraints on specific models of disk-planet interactions.
For instance, using classical prescriptions for type I migration, we show that
when the angular momentum deficit (AMD) of the inner orbit is larger than the
outer's orbit AMD, resonant systems must have a locally inverted disk density
profile to stay locked in resonance during the migration. This inversion is
very untypical of type I migration and our criterion can thus provide an
evidence against classical type I migration. That is indeed the case for the
Jupiter-mass resonant systems HD 60532b, c (3:1 MMR), GJ 876b, c (2:1 MMR), and
HD 45364b, c (3:2 MMR). This result may be an evidence for type II migration
(gap opening planets), which is compatible with the large masses of these
planets.",1506.03750v2
2015-06-26,Spectral statistics of molecular resonances in erbium isotopes: How chaotic are they?,"We perform a comprehensive analysis of the spectral statistics of the
molecular resonances in $^{166}$Er and $^{168}$Er observed in recent ultracold
collision experiments [Frisch et al., Nature {\bf 507}, 475 (2014)] with the
aim of determining the chaoticity of this system. We calculate different
independent statistical properties to check their degree of agreement with
random matrix theory (RMT), and analyze if they are consistent with the
possibility of having missing resonances. The analysis of the short-range
fluctuations as a function of the magnetic field points to a steady increase of
chaoticity until $B \sim 30$ G. The repulsion parameter decreases for higher
magnetic fields, an effect that can be interpreted as due to missing
resonances. The analysis of long-range fluctuations allows us to be more
quantitative and estimate a $20-25\%$ fraction of missing levels. Finally, a
study of the distribution of resonance widths provides additional evidence
supporting missing resonances of small width compared with the experimental
magnetic field resolution. We conclude that further measurements with increased
resolution will be necessary to give a final answer to the problem of missing
resonances and the agreement with RMT.",1506.08086v2
2015-06-27,"CP violation: Dalitz interference, CPT and FSI","Resonances and final state interactions (FSI) play a role in the formation of
CP violation (CPV) constrained by CPT invariance. We provide a general
formulation of CPV including resonances and FSI starting from the CPT
constraint. Our discussion is elaborated within a simple $B$ decay model with
the $\rho$ and $f_0(980)$ resonances plus a non resonant background including
the $\pi\pi \to KK$ coupled amplitude. We consider few illustrative examples to
show the interference patterns appearing in the CP asymmetry, namely, that from
the $\rho$ resonance plus a non-resonant amplitude, and that from the
interference of the $\rho$ and $f_0(980)$ resonances. We perform the fit of the
CP asymmetry for the charmless three-body $B^\pm$ decay channel $B^{\pm}\to
\pi^{\pm} \pi^+\pi^-$ and obtain as outcome the $B^{\pm}\to \pi^{\pm} K^+K^-$
for $\pi\pi$ channel asymmetry in the mass region below $1.6$ GeV in fair
agreement with the new data LHCb data. Analogously, we also describe the CP
asymmetry of the $B^\pm\to K^\pm\pi^+\pi^-$ decay, with that from the $B^\pm\to
K^\pm K^+K^-$ channel obtained as output. As in the previous case, we also
found agreement with LHCb experimental data.",1506.08332v2
2015-08-03,Atomic and molecular complex resonances from real eigenvalues using standard (hermitian) electronic structure calculations,"Complex eigenvalues, resonances, play an important role in large variety of
fields in physics and chemistry. For example, in cold molecular collision
experiments and electron scattering experiments, autoionizing and
pre-dissociative metastable resonances are generated. However, the computation
of complex resonance eigenvalues is difficult, since it requires severe
modifications of standard electronic structure codes and methods. Here we show
how resonance eigenvalues, positions and widths, can be calculated using the
standard, widely used, electronic-structure packages. Our method enables the
calculations of the complex resonance eigenvalues by using analytical
continuation procedures (such as Pad\'{e}). The key point in our approach is
the existence of narrow analytical passages from the real axis to the complex
energy plane. In fact, the existence of these analytical passages relies on
using finite basis sets. These passages become narrower as the basis set
becomes more complete, whereas in the exact limit, these passages to the
complex plane are closed.
  As illustrative numerical examples we calculated the autoionization
resonances of helium, hydrogen anion and hydrogen molecule. We show that our
results are in an excellent agreement with the results obtained by other
theoretical methods and with available experimental results.",1508.00439v1
2015-08-30,Asymptotic normalization coefficients of resonant and bound states from the phase shifts for $αα$ and $α^{12}\rm C$ scattering,"Recently we have published a paper [Irgaziev, Phys. Rev. C 91, 024002 (2015)]
where the $S$-matrix pole method (SMP) which is only valid for resonances has
been developed to derive a new explicit expression for the asymptotic
normalization coefficient (ANC), and is applied to the low-energy resonant
states of nucleon$+\alpha$ and $\alpha+^{12}\rm{C}$ systems. The SMP results
are compared with the effective-range expansion method (EFE) results. In the
present paper the SMP and EFE plus the Pad\'e-approximation are applied to
study the excited 2$^+$ resonant states of $^{8}\rm{Be}$. A contradiction is
found between descriptions of the experimental phase shift data for
$\alpha\alpha$ scattering and of the $^{8}\rm{Be}$ resonant energy for 2$^+$
state. Using the EFE method, we also calculate the ANC for the $^{8}\rm{Be}$
ground 0$^+$ state with a very small width. This ANC agrees well with the value
calculated using the known analytical expression for narrow resonances. In
addition, for the $\alpha+^{12}\rm{C}$ states1$^-$ and 3$^-$ the SMP results
are compared with the Pad\'e-approximation results. We find that the
Pad\'e-approximation improves a resonance width description compared with the
EFE results. The EFE method is also used to calculate the ANCs for the bound
$^{16}\rm{O}$ ground 0$^+$ state and for the excited 1$^-$ and 2$^+$ levels
which are situated near the threshold of $\alpha+^{12}\rm{C}$ channel.",1508.07538v3
2015-09-07,Power-laws in the dynamic hysteresis of quantum nonlinear photonic resonators,"We explore theoretically the physics of dynamic hysteresis for
driven-dissipative nonlinear photonic resonators. In the regime where the
semiclassical mean-field theory predicts bistability, the exact steady-state
density matrix is known to be unique, being a statistical mixture of two
states: in particular, no static hysteresis cycle of the excited population
occurs as a function of the driving intensity. Here, we predict that in the
quantum regime a dynamic hysteresis with a rich phenomenology does appear when
sweeping the driving amplitude in a finite time. The hysteresis area as a
function of the sweep time reveals a double power-law decay, with a behavior
qualitatively different from the mean-field predictions. The dynamic hysteresis
power-law in the slow sweep limit defines a characteristic time, which depends
dramatically on the size of the nonlinearity and on the frequency detuning
between the driving and the resonator. In the strong nonlinearity regime, the
characteristic time oscillates as a function of the intrinsic system parameters
due to multiphotonic resonances. We show that the dynamic hysteresis for the
considered class of driven-dissipative systems is due to a non-adiabatic
response region with connections to the Kibble-Zurek mechanism for quenched
phase transitions. We also consider the case of two coupled driven-dissipative
nonlinear resonators, showing that dynamic hysteresis and power-law behavior
occur also in presence of correlations between resonators. Our theoretical
predictions can be explored in a broad variety of physical systems, e.g.,
circuit QED superconducting resonators and semiconductor optical microcavities.",1509.02118v2
2015-10-12,Broken selection rule in the quantum Rabi model,"Understanding the interaction between light and matter is very relevant for
fundamental studies of quantum electrodynamics and for the development of
quantum technologies. The quantum Rabi model captures the physics of a single
atom interacting with a single photon at all regimes of coupling strength. We
report the spectroscopic observation of a resonant transition that breaks a
selection rule in the quantum Rabi model, implemented using an $LC$ resonator
and an artificial atom, a superconducting qubit. The eigenstates of the system
consist of a superposition of bare qubit-resonator states with a relative sign.
When the qubit-resonator coupling strength is negligible compared to their own
frequencies, the matrix element between excited eigenstates of different sign
is very small in presence of a resonator drive, establishing a sign-preserving
selection rule. Here, our qubit-resonator system operates in the ultrastrong
coupling regime, where the coupling strength is 10\% of the resonator
frequency, allowing sign-changing transitions to be activated and, therefore,
detected. This work shows that sign-changing transitions are an unambiguous,
distinctive signature of systems operating in the ultrastrong coupling regime
of the quantum Rabi model. These results pave the way to further studies of
sign-preserving selection rules in multiqubit and multiphoton models.",1510.03379v2
2015-10-12,Interference effect on heavy Higgs resonance signal in γγand ZZ channels,"The resonance-continuum interference is usually neglected when the width of a
resonance is small compared to the resonance mass. We re-examine this standard
by studying the interference effects in high-resolution decay channels,
$\gamma\gamma$ and $ZZ$, of the heavy Higgs boson $H^0$ in nearly aligned
two-Higgs-doublet models. For the $H^0$ with a sub-percent width-to-mass ratio,
we find that, in the parameter space where the LHC 14 TeV $ZZ$ resonance search
can be sensitive, the interference effects can modify the $ZZ$ signal rate by
${\cal O}(10)\%$ and the exclusion reach by ${\cal O}(10)$ GeV. In other
parameter space where the $ZZ$ or $\gamma\gamma$ signal rate is smaller, the
LHC 14 TeV reach is absent, but a resonance shape can be much more dramatically
changed. In particular, the $\gamma\gamma$ signal rate can change by ${\cal
O}(100)\%$. Relevant to such parameter space, we suggest variables that can
characterize a general resonance shape. We also illustrate the relevance of the
width on the interference by adding non-standard decay modes of the heavy Higgs
boson.",1510.03450v2
2015-10-25,Towards nature of the X(3872) resonance,"We construct spectra of decays of the resonance X(3872) with good analytical
and unitary properties which allows to define the branching ratio of the
X(3872) \to D^{*0}\bar D^0 + c.c. decay studying only one more decay, for
example, the X(3872)\to\pi^+\pi^- J/\psi(1S) decay, and show that our spectra
are effective means of selection of models for the resonance X(3872).
  Then we discuss the scenario where the X(3872 resonance is the c\bar c =
\chi_{c1}(2P) charmonium which ""sits on"" the D^{*0}\bar D^0 threshold.
  We explain the shift of the mass of the X(3872) resonance with respect to the
prediction of a potential model for the mass of the \chi_{c1}(2P) charmonium by
the contribution of the virtual D^*\bar D+c.c. intermediate states into the
self energy of the X(3872) resonance. This allows us to estimate the coupling
constant of the X(7872) resonance with the D^{*0}\bar D^0 channel, the
branching ratio of the X(3872) \to D^{*0}\bar D^0 + c.c. decay, and the
branching ratio of the X(3872) decay into all non-D^{*0}\bar D^0 + c.c. states.
We predict a significant number of unknown decays of X(3872) via two
gluons:X(3872)\to gluons\ gluon\to hadrons.",1510.07251v1
2016-01-04,Gluon vs. Photon Production of a 750 GeV Diphoton Resonance,"The production mechanism of a 750 GeV diphoton resonance, either via gluon or
photon fusion, can be probed by studying kinematic observables in the diphoton
events. We perform a detector study of the two production modes of a
hypothetical scalar or tensor diphoton resonance in order to characterize the
features of the two scenarios. The nature of the resonance production can be
determined from the jet multiplicity, the jet and diphoton rapidities, the rate
of central pseudorapidity gaps, or the possible detection of forward protons
from elastic photoproduction for events in the signal region. Kinematic
distributions for both signals and expected irreducible diphoton background
events are provided for comparison along with a study of observables useful for
distinguishing the two scenarios at an integrated luminosity of 20 fb$^{-1}$.
We find that decay photons from a 750 GeV scalar resonance have a preference
for acceptance in the central detector barrel, while background events are more
likely to give accepted photons in the detector end caps. This disfavors the
interpretation of the large number of excess events found by the the Run-2 CMS
diphoton search with one photon detected in the end cap as a wide spin-0
resonance signal. However, one expects more end cap photons in the case of
spin-2 resonance.",1601.00638v3
2016-02-01,Calibration scheme for large Kinetic Inductance Detector Arrays based on Readout Frequency Response,"Microwave kinetic inductance detector (MKID) provides a way to build large
ground based sub-mm instruments such as NIKA and A-MKID. For such instruments,
therefore, it is important to understand and characterize the response to
ensure good linearity and calibration over wide dynamic range. We propose to
use the MKID readout frequency response to determine the MKID responsivity to
an input optical source power. A signal can be measured in a KID as a change in
the phase of the readout signal with respect to the KID resonant circle.
Fundamentally, this phase change is due to a shift in the KID resonance
frequency, in turn due to a radiation induced change in the quasiparticle
number in the superconducting resonator. We show that shift in resonant
frequency can be determined from the phase shift by using KID phase versus
frequency dependence using a previously measured resonant frequency. Working in
this calculated resonant frequency, we gain near linearity and constant
calibration to a constant optical signal applied in a wide range of operating
points on the resonance and readout powers. This calibration method has three
particular advantages: first, it is fast enough to be used to calibrate large
arrays, with pixel counts in the thousand of pixels; second, it is based on
data that are already necessary to determine KID positions; third, it can be
done without applying any optical source in front of the array.",1602.00442v1
2016-03-23,Multi-photon transitions and Rabi resonance in continuous wave EPR,"The study of microwave and radiofrequency multi-photon transitions in
continuous wave (CW) EPR spectroscopy is extended to a Rabi resonance
condition, when the radio frequency of the magnetic-field modulation matches
the Rabi frequency of a spin system in the microwave field. Using the
non-secular perturbation theory based on the Bogoliubov averaging method, the
analytical description of the response of the spin system is derived for all
modulation frequency harmonics. When the modulation frequency exceeds the EPR
linewidth, multi-photon transitions result in sidebands in absorption EPR
spectra measured with phase-sensitive detection at any harmonic. The saturation
of different-order multi-photon transitions is shown to be significantly
different and to be sensitive to the Rabi resonance. The noticeable frequency
shifts of sidebands are found to be the signatures of this resonance. The
inversion of two-photon lines in some spectral intervals of the out-of-phase
first-harmonic signal is predicted under passage through the Rabi resonance.
The inversion indicates the transition from absorption to stimulated emission
or vice versa, depending on the sideband. The manifestation of the primary and
secondary Rabi resonance is also demonstrated in time-resolved steady-state EPR
signals formed by all harmonics of the modulation frequency. Our results
provide a theoretical framework for future developments in multi-photon CW EPR
spectroscopy, which can be useful for samples with long spin relaxation times
and extremely narrow EPR lines",1603.07228v1
2016-04-04,Effects of Tsallis distribution on parametric resonance in chiral phase transitions,"The parametric resonance was studied in chiral phase transitions when the
momentum distribution is described by a Tsallis distribution. A Tsallis
distribution has two parameters, the temperature $T$ and the entropic index
$q$. The amplification was estimated in two cases: 1) expansionless case and 2)
one dimensional expansion case. In an expansionless case, the temperature $T$
is constant, and the amplified modes as a function of $T$ were calculated for
various $q$. In one dimensional expansion case, the temperature $T$ decreases
as a function of the proper time, and the amplification as a function of the
transverse momentum was calculated for various $q$. In the expansionless case,
the following facts were found: 1) the larger the value $q$ is, the softer the
amplified modes are for the first and second resonance bands, 2) the amplified
mode of the first resonance band decreases and vanishes, as the temperature $T$
increases, and 3) the amplified mode of the second resonance band decreases and
approaches to zero, as the temperature $T$ increases. In one dimensional
expansion case, the following facts were found: 1) the soft mode is amplified,
2) the amplification is extremely strong around the amplified mode of the first
resonance band at $T=0$, and 3) the magnitude of the amplification as a
function of transverse momentum oscillates around the amplified mode of the
first resonance band at $T=0$.",1604.00871v1
2016-04-06,The 750 GeV Resonance as Non-Minimally Coupled Inflaton: Unitarity Violation and Why the Resonance is a Real Singlet Scalar,"The 750 GeV resonance observed by ATLAS and CMS may be explained by a gauge
singlet scalar. This would provide an ideal candidate for a gauge singlet
scalar alternative to Higgs Inflation, S-inflation. Here we discuss the
relevant results of S-inflation in the context of the 750 GeV resonance. In
particular, we show that a singlet scalar, if it is real, has a major advantage
over the Higgs boson with regard to unitarity violation during inflation. This
is because it is possible to restrict the large non-minimal coupling required
for inflation, $\xi \sim 10^5$, to the real singlet scalar, with all other
scalars having $\xi \sim 1$. In this case the scale of unitarity violation
$\Lambda$ is much larger than the inflaton field during inflation. This
protects the inflaton effective potential from modification by the new physics
or strong coupling which is necessary to restore unitarity, which would
otherwise invalidate the perturbative effective potential based on Standard
Model physics. This is in contrast to the case of Higgs Inflation or models
based on complex singlet scalars, where the unitarity violation scale during
inflation is less than or of the order of the inflaton field. Therefore if the
750 GeV resonance is the inflaton, it must be a non-minimally coupled real
singlet scalar.",1604.01711v2
2016-04-20,Nonlinear wave damping due to multi-plasmon resonances,"For short wavelengths, it is well known that the linearized Wigner-Moyal
equation predicts wave damping due to wave-particle interaction, where the
resonant velocity shifted from the phase velocity by a velocity $v_q = \hbar
k/2m$. Here $\hbar$ is the reduced Planck constant, $k$ is the wavenumber and
$m$ is the electron mass. Going beyond linear theory, we find additional
resonances with velocity shifts $n v_q$, $n = 2, 3, \ldots$, giving rise to a
new wave-damping mechanism that we term \emph{multi-plasmon damping}, as it can
be seen as the simultaneous absorption (or emission) of multiple plasmon
quanta. Naturally this wave damping is not present in classical plasmas. For a
temperature well below the Fermi temperature, if the linear ($n = 1$) resonant
velocity is outside the Fermi sphere, the number of linearly resonant particles
is exponentially small, while the multi-plasmon resonances can be located in
the bulk of the distribution. We derive sets of evolution equations for the
case of two-plasmon and three-plasmon resonances for Langmuir waves in the
simplest case of a fully degenerate plasma. By solving these equations
numerically for a range of wave-numbers we find the corresponding damping
rates, and we compare them to results from linear theory to estimate the
applicability. Finally, we discuss the effects due to a finite temperature.",1604.05983v2
2016-04-28,Universal Symmetry-Protected Resonances in a Spinful Luttinger Liquid,"We study the problem of resonant tunneling through a quantum dot in a spinful
Luttinger liquid. For a range of repulsive interactions, we find that for
symmetric barriers there exist resonances with a universal peak conductance
$2g^* e^2/h$ that are controlled by a non-trivial intermediate fixed point.
This fixed point is also a quantum critical point separating symmetry-protected
topological phases. By tuning the system through resonance, all SPT phases can
be accessed. For a particular interaction strength with Luttinger parameters
$g_\rho=1/3$ and $g_\sigma=1$, we show that the problem is equivalent to a two
channel $SU(3)$ Kondo problem($SU(3)_2$ CFT). At the Toulouse limit, both
problems can be mapped to a quantum Brownian motion model on a Kagome lattice,
which in turn is related to the quantum Brownian motion on a honeycomb lattice
and the three-channel $SU(2)$ Kondo problem($SU(2)_3$ CFT). ""Level-rank
duality"" in the quantum Brownian motion model relating $SU(2)_k$ CFT to
$SU(k)_2$ CFT is also explored. Utilizing the boundary conformal field theory,
the on-resonance conductance of our resonant tunneling problem is calculated as
well as the scaling dimension of the leading relevant operator. This allows us
to compute the scaling behavior of the resonance line-shape as a function of
temperature.",1604.08280v2
2016-06-29,Double resonance response of a superconducting quantum metamaterial: manifestation of non-classical states of photons,"We report a theoretical study of ac response of superconducting quantum
metamaterials (SQMs), i.e. an array of qubits (two-levels system) embedded in
the low-dissipative resonator. By making use of a particular example of SQM,
namely the array of charge qubits capacitively coupled to the resonator, we
obtain a second-order phase transition between an incoherent (the
high-temperature phase) and coherent (the low-temperatures phase) states of
photons. This phase transition in many aspects resembles the
paramagnetic-ferromagnetic phase transition. The critical temperature of the
phase transition, $T^\star$, is determined by the energy splitting of two-level
systems $\delta$, number of qubits in the array $N$, and the strength of the
interaction $\eta$ between qubits and photons in the cavity. We obtain that the
photon states manifest themselves by resonant drops in the frequency dependent
transmission $D(\omega)$ of electromagnetic waves propagating through a
transmission line weakly coupled to the SQM. At high temperatures the
$D(\omega)$ displays a single resonant drop, and at low temperatures a peculiar
\emph{double resonance response} has to be observed. The physical origin of
such a resonant splitting is the quantum oscillations between two coherent
states of photons of different polarizations.",1606.09078v1
2016-06-29,"Experimental Study of Nonlinear Resonances and Anti-resonances in a Forced, Ordered Granular Chain","We experimentally study a one-dimensional uncompressed granular chain
composed of a finite number of identical spherical beads with Hertzian
interactions. The chain is harmonically excited by an amplitude- and
frequency-dependent boundary drive at its left end and has a fixed boundary at
its right end. Such ordered granular media represent an interesting new class
of nonlinear acoustic metamaterials, since they exhibit essentially nonlinear
acoustics and have been designated as 'sonic vacua' due to the fact that their
corresponding speed of sound (as defined in classical acoustics) is zero.This
paves the way for essentially nonlinear and energy-dependent acoustics with no
counterparts in linear theory. We experimentally detect time-periodic, strongly
nonlinear resonances whereby the particles (beads) of the granular chain
respond at integer multiples of the excitation period, and which correspond to
local peaks of the maximum transmitted force at the chain's right, fixed end.In
between these resonances we detect a local minimum of the maximum transmitted
forces corresponding to an anti-resonance in the stationary-state dynamics. The
experimental results of this work confirm previous theoretical predictions, and
verify the existence of strongly nonlinear resonance responses in a system with
a complete absence of any linear spectrum; as such, the experimentally detected
nonlinear resonance spectrum is passively tunable with energy and sensitive to
dissipative effects such as internal structural damping in the beads, and
friction or plasticity effects. The experimental results are verified by direct
numerical simulations and by numerical stability analysis.",1606.09305v1
2017-03-09,Resonances - lost and found,"We consider the large $L$ limit of one dimensional Schr\""odinger operators
$H_L=-d^2/dx^2 + V_1(x) + V_{2,L}(x)$ in two cases: when $V_{2,L}(x)=V_2(x-L)$
and when $V_{2,L}(x)=e^{-cL}\delta(x-L)$. This is motivated by some recent work
of Herbst and Mavi where $V_{2,L}$ is replaced by a Dirichlet boundary
condition at $L$. The Hamiltonian $H_L$ converges to $H = -d^2/dx^2 + V_1(x)$
as $L\to \infty$ in the strong resolvent sense (and even in the norm resolvent
sense for our second case). However, most of the resonances of $H_L$ do not
converge to those of $H$. Instead, they crowd together and converge onto a
horizontal line: the real axis in our first case and the line $\Im(k)=-c/2$ in
our second case. In the region below the horizontal line resonances of $H_L$
converge to the reflectionless points of $H$ and to those of $-d^2/dx^2 +
V_2(x)$. It is only in the region between the real axis and the horizontal line
(empty in our first case) that resonances of $H_L$ converge to resonances of
$H$. Although the resonances of $H$ may not be close to any resonance of $H_L$
we show that they still influence the time evolution under $H_L$ for a long
time when $L$ is large.",1703.03172v2
2018-02-06,Detecting Ultrasound Vibrations by Graphene Resonators,"Ultrasound detection is one of the most important nondestructive subsurface
characterization tools of materials, whose goal is to laterally resolve the
subsurface structure with nanometer or even atomic resolution. In recent years,
graphene resonators attracted attention as loudspeaker and ultrasound radio,
showing its potential to realize communication systems with air-carried
ultrasound. Here we show a graphene resonator that detects ultrasound
vibrations propagating through the substrate on which it was fabricated. We
achieve ultimately a resolution of $\approx7$~pm/$\mathrm{\sqrt Hz}$ in
ultrasound amplitude at frequencies up to 100~MHz. Thanks to an extremely high
nonlinearity in the mechanical restoring force, the resonance frequency itself
can also be used for ultrasound detection. We observe a shift of 120~kHz at a
resonance frequency of 65~MHz for an induced vibration amplitude of 100~pm with
a resolution of 25~pm. Remarkably, the nonlinearity also explains the generally
observed asymmetry in the resonance frequency tuning of the resonator when
pulled upon with an electrostatic gate. This work puts forward a sensor design
that fits onto an atomic force microscope cantilever and therefore promises
direct ultrasound detection at the nanoscale for nondestructive subsurface
characterization.",1802.01906v3
2018-04-09,Discrete resonant Rossby/drift wave triads: an explicit parameterisation and a fast direct numerical search algorithm,"We report results on the explicit parameterisation of discrete Rossby-wave
resonant triads of the Charney-Hasegawa-Mima equation in the small-scale limit
(i.e. large Rossby deformation radius), following up from our previous solution
in terms of elliptic curves (Bustamante and Hayat, 2013). We find an explicit
parameterisation of the discrete resonant wavevectors in terms of two rational
variables. We show that these new variables are restricted to a bounded region
and find this region explicitly. We argue that this can be used to reduce the
complexity of a direct numerical search for discrete triad resonances. Also, we
introduce a new direct numerical method to search for discrete resonances. This
numerical method has complexity ${\mathcal{O}}(N^3)$, where $N$ is the largest
wavenumber in the search. We apply this new method to find all discrete
irreducible resonant triads in the wavevector box of size $5000$, in a
calculation that took about $10.5$ days on a $16$-core machine. Finally, based
on our method of mapping to elliptic curves, we discuss some dynamical
implications regarding the spread of quadratic invariants across scales via
resonant triad interactions, in the form of sharp bounds on the size of the
interacting wavevectors.",1804.03092v1
2018-04-18,Excitation transfer from Second to First resonance line of Potassium observed in hot atomic vapor,"We present experimental investigation on the fluorescence profiles observed
by excitation of the hyperfine transitions of the second resonance line of
potassium with a wavelength of 404.4 nm in dependence on the atomic density.
This leads to both direct decay of the excited level population to the ground
state (violet fluorescence), and to cascade decay via the first resonance lines
(infrared fluorescence). It has been shown that the behavior of these two
fluorescence profiles is different: increasing the atomic density, the violet
fluorescence profile exhibits a well-pronounced self-absorption dip, while the
infrared line does not show any narrow-width reduced absorption structure.
Moreover, the profiles of the infrared line have a higher signal-to-noise ratio
than that of the violet line. Our investigations show that beside atomic
population, atomic polarization is also transferred by the cascade transitions.
This is evidenced by registration of coherent magneto-optical resonances at the
two fluorescence lines. The signal-to-noise ratio of these resonances
registered at the first resonance line is significantly higher than at those
obtained at the second resonance line. The proposed study makes it possible to
examine cascade transitions in alkali atoms, particularly the preservation of
atomic polarization, i.e. the coherence transfer by cascade transitions.",1804.06762v1
2018-04-24,Optomechanical cooling and self-stabilization of a waveguide coupled to a whispering-gallery-mode resonator,"Laser cooling of mechanical degrees of freedom is one of the most significant
achievements in the field of opto-mechanics. Here, we report, for the first
time to the best of our knowledge, efficient passive optomechanical cooling of
the motion of a freestanding waveguide coupled to a whispering-gallery-mode
(WGM) resonator. The waveguide is an 8 mm long glass-fiber nanospike, which has
a fundamental flexural resonance at {\Omega}/2{\pi} = 2.5 kHz and a Q-factor of
1.2 10**5. Upon launching 250 {\mu}W laser power at an optical frequency close
to the WGM resonant frequency, we observed cooling of the nanospike resonance
from room temperature down to 1.8 K. Simultaneous cooling of the first
higher-order mechanical mode is also observed. The strong suppression of the
overall Brownian motion of the nanospike, observed as an 11.6 dB reduction in
its mean square displacement, indicates strong optomechanical stabilization of
linear coupling between the nanospike and the cavity mode. The cooling is
caused predominantly by a combination of photothermal effects and optical
forces between nanospike and WGM resonator. The results are of direct relevance
in the many applications of WGM resonators, including atom physics,
optomechanics, and sensing.",1804.09115v2
2018-11-21,Collider phenomenology of vector resonances in WZ scattering processes,"We study the production of vector resonances at the LHC via $WZ$ scattering
processes and explore the sensitivities to these resonances for the expected
future LHC luminosities. The electroweak chiral Lagrangian and the Inverse
Amplitude Method (IAM) are used for analyzing a dynamically generated vector
resonance, whose origin would be the (hypothetically strong) self interactions
of the longitudinal gauge bosons, $W_L$ and $Z_L$. We implement the unitarized
scattering amplitudes into a single model, the IAM-MC, that has been adapted to
MadGraph~5. It is written in terms of the electroweak chiral Lagrangian and an
additional effective Proca Lagrangian for the vector resonances, so that it
reproduces the resonant behavior of the IAM and allows us to perform a
realistic study of signal versus background at the LHC. We focus on the $pp\to
WZjj$ channel, discussing first on the potential of the hadronic and
semileptonic channels of the final $WZ$, and next exploring in more detail the
clearest signals. These are provided by the leptonic decays of the gauge
bosons, leading to a final state with $l^+_1l^-_1l^+_2\nu jj$, $l=e,\mu$,
having a very distinctive signature, and showing clearly the emergence of the
resonances with masses in the range of $1.5$-$2.5\,{\rm TeV}$, which we have
explored.",1811.08720v1
2019-05-05,Dipole coupling of a tunable hole double quantum dot in germanium hut wire to a microwave resonator,"The germanium (Ge) hut wire system has strong spin-orbit coupling, a long
coherence time due to a very large heavy-light hole splitting, and the
advantage of site-controlled large-scale hut wire positioning. These properties
make the Ge hut wire a promising candidate for the realization of strong
coupling of spin to superconducting resonators and scalability for multiple
qubit coupling. We have coupled a reflection line resonator to a hole double
quantum dot (DQD) formed in Ge hut wire. The amplitude and phase responses of
the microwave resonator revealed that the charge stability diagrams of the DQD
are in good agreement with those obtained from transport measurements. The DQD
interdot tunneling rate is shown to be tunable from 6.2 GHz to 8.5 GHz, which
demonstrates the ability to adjust the frequency detuning between the qubit and
the resonator. Furthermore, we achieved a hole-resonator coupling strength of
up to 15 MHz, with a charge qubit decoherence rate of 0.28 GHz. Meanwhile the
hole spin-resonator coupling rate was estimated to be 3 MHz. These results
suggest that holes of a DQD in a Ge hut wire are dipole coupled to microwave
photons, potentially enabling tunable hole spin-photon interactions in Ge with
an inherent spin-orbit coupling.",1905.01586v2
2019-05-11,"Resonant, broadband and highly efficient optical frequency conversion in semiconductor nanowire gratings at visible and UV wavelengths","Using a hydrodynamic approach we examine bulk- and surface-induced second and
third harmonic generation from semiconductor nanowire gratings having a
resonant nonlinearity in the absorption region. We demonstrate resonant,
broadband and highly efficient optical frequency conversion: contrary to
conventional wisdom, we show that harmonic generation can take full advantage
of resonant nonlinearities in a spectral range where nonlinear optical
coefficients are boosted well beyond what is achievable in the transparent,
long-wavelength, non-resonant regime. Using femtosecond pulses with
approximately 500 MW/cm2 peak power density, we predict third harmonic
conversion efficiencies of approximately 1% in a silicon nanowire array, at
nearly any desired UV or visible wavelength, including the range of negative
dielectric constant. We also predict surface second harmonic conversion
efficiencies of order 0.01%, depending on the electronic effective mass,
bistable behavior of the signals as a result of a reshaped resonance, and the
onset fifth order nonlinear effects. These remarkable findings, arising from
the combined effects of nonlinear resonance dispersion, field localization, and
phase-locking, could significantly extend the operational spectral bandwidth of
silicon photonics, and strongly suggest that neither linear absorption nor skin
depth should be motivating factors to exclude either semiconductors or metals
from the list of useful or practical nonlinear materials in any spectral range.",1905.04516v1
2019-05-24,Search for low-mass quark-antiquark resonances produced in association with a photon at $\sqrt{s} = $ 13 TeV,"A search for narrow low-mass resonances decaying to quark-antiquark pairs is
presented. The search is based on proton-proton collisions events collected at
13 TeV by the CMS detector at the CERN LHC. The data sample corresponds to an
integrated luminosity of 35.9 fb$^{-1}$, recorded in 2016. The search considers
the case where the resonance has high transverse momentum due to initial-state
radiation of a hard photon. To study this process, the decay products of the
resonance are reconstructed as a single large-radius jet with two-pronged
substructure. The signal would be identified as a localized excess in the jet
invariant mass spectrum. No evidence for such a resonance is observed in the
mass range 10 to 125 GeV. Upper limits at the 95% confidence level are set on
the coupling strength of resonances decaying to quark pairs. The results
obtained with this photon trigger strategy provide the first direct constraints
on quark-antiquark resonance masses below 50 GeV obtained at a hadron collider.",1905.10331v2
2020-07-15,Spin resonance linewidths of bismuth donors in silicon coupled to planar microresonators,"Ensembles of bismuth donor spins in silicon are promising storage elements
for microwave quantum memories due to their long coherence times which exceed
seconds. Operating an efficient quantum memory requires achieving critical
coupling between the spin ensemble and a suitable high-quality factor resonator
-- this in turn requires a thorough understanding of the lineshapes for the
relevant spin resonance transitions, particularly considering the influence of
the resonator itself on line broadening. Here, we present pulsed electron spin
resonance measurements of ensembles of bismuth donors in natural silicon, above
which niobium superconducting resonators have been patterned. By studying spin
transitions across a range of frequencies and fields we identify distinct line
broadening mechanisms, and in particular those which can be suppressed by
operating at magnetic-field-insensitive `clock transitions'. Given the donor
concentrations and resonator used here, we measure a cooperativity $C\sim 0.2$
and based on our findings we discuss a route to achieve unit cooperativity, as
required for a quantum memory.",2007.07600v3
2010-05-12,Is the nonmonotonic behavior in the cross section of phi photoproduction near threshold a signature of a resonance?,"We study whether the nonmonotonic behavior found in the differential cross
section of the phi-meson photoproduction near threshold can be described by a
resonance. Namely, we add a resonance to a model consisting of Pomeron and
(pi,eta) exchange by fiat and see if, with a suitable assignment of spin and
parity, mass and width, as well as the coupling constants, one would be able to
obtain a good description to all the data reported by the LEPS collaboration in
the low-energy region. The resonant contribution is evaluated by using an
effective Lagrangian approach. We find that, with the assumption of a J^P=3/2^-
resonance with mass of 2.10 +- 0.03 GeV and width of 0.465 +- 0.141 GeV, LEPS
data can indeed be well described. The ratio of the helicity amplitudes
A_(1/2)/A_(3/2) calculated from the resulting coupling constants differs in
sign from that of the known D13(2080). We further find that the addition of
this postulated resonance can substantially improve the agreement between the
existing theoretical predictions and the recent omega photoproduction data if a
large value of the OZI evading parameter x_OZI = 12 is assumed for the
resonance.",1005.2105v2
2014-03-18,Dynamically-generated baryon resonances with heavy flavor,"We study baryon resonances with heavy flavor in a molecular approach, thus as
dynamically generated by meson-baryon scattering. This is accomplished by using
a unitary coupled-channel model taking, as bare interaction, the extension to
four flavors and spin symmetry of the Weinberg-Tomozawa interaction potential.
A special attention is paid to the inclusion of heavy-quark spin symmetry and
to the studies of the generated baryon resonances which complete the
heavy-quark spin multiplets. We reproduce few charmed and strange baryon
resonances found experimentally, that is, \Lambda_c(2595), \Lambda_c(2625),
\Xi_c(2790), \Xi_c(2815), and make predictions for more states. The
bottom-flavored \Lambda_b(5912) and \Lambda_b(5920) states, found by the LHCb
collaboration, are also obtained by our model, thus these resonances can be
interpreted as molecular states. We also study \Xi_b resonances, which belong
to the same SU(3) x HQSS multiplets as the observed \Lambda_b particles.
Finally we analyze hidden-charm baryon resonances. In this sector, we predict
seven N-like and five \Delta-like states with masses around 4 GeV, most of them
as bound states, and compare them with predictions from other models. The
predicted states can be searched for in future experiments that involve studies
of heavy-flavor physics, e.g. PANDA/FAIR, where charm physics will be analyzed.",1403.4515v1
2014-03-25,Time evolution of cascade decay,"We study non-perturbatively the time evolution of cascade decay for generic
fields $\pi \rightarrow \phi_1\phi_2\rightarrow \phi_2\chi_1\chi_2$ and obtain
the time dependence of amplitudes and populations for the resonant and final
states. We analyze in detail the different time scales and the manifestation of
unitary time evolution in the dynamics of production and decay of resonant
intermediate and final states. The probability of occupation (population)
""flows"" as a function of time from the initial to the final states. When the
decay width of the parent particle $\Gamma_\pi$ is much larger than that of the
intermediate resonant state $\Gamma_{\phi_1}$ there is a ""bottleneck"" in the
flow, the population of resonant states builds up to a maximum at $t^* =
\ln[\Gamma_\pi/\Gamma_{\phi_1}]/(\Gamma_\pi-\Gamma_{\phi_1})$ nearly saturating
unitarity and decays to the final state on the longer time scale
$1/\Gamma_{\phi_1}$. As a consequence of the wide separation of time scales in
this case the cascade decay can be interpreted as evolving sequentially $\pi
\rightarrow \phi_1\phi_2; ~ \phi_1\phi_2\rightarrow \phi_2\chi_1\chi_2$. In the
opposite limit the population of resonances ($\phi_1$) does not build up
substantially and the cascade decay proceeds almost directly from the initial
parent to the final state without resulting in a large amplitude of the
resonant state. An alternative but equivalent non-perturbative method useful in
cosmology is presented. Possible phenomenological implications for heavy
sterile neutrinos as resonant states and consequences of quantum entanglement
and correlations in the final state are discussed.",1403.6366v2
2017-04-12,Controlling the gain contribution of background emitters in few-quantum-dot microlasers,"We provide experimental and theoretical insight into single-emitter lasing
effects in a quantum dot (QD)-microlaser under controlled variation of
background gain provided by off-resonant discrete gain centers. For that
purpose, we apply an advanced two-color excitation concept where the background
gain contribution of off-resonant QDs can be continuously tuned by precisely
balancing the relative excitation power of two lasers emitting at different
wavelengths. In this way, by selectively exciting a single resonant QD and
off-resonant QDs, we identify distinct single-QD signatures in the lasing
characteristics and distinguish between gain contributions of a single resonant
emitter and a countable number of off-resonant background emitters to the
optical output of the microlaser. We address the important question whether
single-QD lasing is feasible in experimentally accessible systems and show
that, for the investigated microlaser, the single-QD gain needs to be supported
by the background gain contribution of off-resonant QDs to reach the transition
to lasing. Interestingly, while a single QD cannot drive the investigated
micropillar into lasing, its relative contribution to the emission can be as
high as 70% and it dominates the statistics of emitted photons in the
intermediate excitation regime below threshold.",1704.03902v1
2017-04-15,Nucleon resonances in $γp \to K^{*+} Λ$,"The high-precision cross-section data for the reaction $\gamma p \to
K^{*+}\Lambda$ reported by the CLAS Collaboration at the Thomas Jefferson
National Accelerator Facility have been analyzed based on an effective
Lagrangian approach in the tree-level approximation. Apart from the $t$-channel
$K$, $\kappa$, $K^*$ exchanges, the $s$-channel nucleon ($N$) exchange, the
$u$-channel $\Lambda$, $\Sigma$, $\Sigma^*(1385)$ exchanges, and the
generalized contact term, the contributions from the near-threshold nucleon
resonances in the $s$-channel are also taken into account in constructing the
reaction amplitude. It is found that, to achieve a satisfactory description of
the differential cross section data, at least two nucleon resonances should be
included. By including the $N(2060){5/2}^-$ resonance, which is responsible for
the shape of the angular distribution near the $K^*\Lambda$ threshold, and one
of the $N(2000){5/2}^+$, $N(2040){3/2}^+$, $N(2100){1/2}^+$, $N(2120){3/2}^-$
and $N(2190){7/2}^-$ resonances, one can describe the cross-section data quite
well, with the fitted resonance masses and widths compatible with those
advocated by the Particle Data Group. The resulted predictions of the beam,
target, and recoil asymmetries are found to be quite different from various
fits, indicating the necessity of the spin observable data for $\gamma p \to
K^{*+}\Lambda$ to further pin down the resonance contents and associated
parameters in this reaction.",1704.04562v1
2011-11-17,Resonant Alfven waves in partially ionized plasmas of the solar atmosphere,"Context. Magnetohydrodynamic (MHD) waves are ubiquitous in the solar
atmosphere. In magnetic waveguides resonant absorption due to plasma
inhomogeneity naturally transfers wave energy from large-scale motions to
small-scale motions. In the cooler parts of the solar atmosphere as, e.g., the
chromosphere, effects due to partial ionization may be relevant for wave
dynamics and heating. Aims. We study resonant Alfven waves in partially ionized
plasmas. Methods. We use the multifluid equations in the cold plasma
approximation. We investigate propagating resonant MHD waves in partially
ionized flux tubes. We use approximate analytical theory based on normal modes
in the thin tube and thin boundary approximations along with numerical
eigenvalue computations. Results. We find that the jumps of the wave
perturbations across the resonant layer are the same as in fully ionized
plasmas. The damping length due to resonant absorption is inversely
proportional to the frequency, while that due to ion-neutral collisions is
inversely proportional to the square of the frequency. For observed frequencies
in the solar atmosphere, the amplitude of MHD kink waves is more efficiently
damped by resonant absorption than by ion-neutral collisions. Conclusions. Most
of the energy carried by chromospheric kink waves is converted into localized
azimuthal Alfven waves that can deposit energy in the coronal medium. The
dissipation of wave energy in the chromosphere due to ion-neutral collisions is
only effective for high-frequency waves. The chromosphere acts as a filter for
kink waves with periods shorter than 10 s.",1111.4134v1
2012-04-04,Traditional formation scenarios fail to explain 4:3 mean motion resonances,"At least two multi-planetary systems in a 4:3 mean motion resonance have been
found by radial velocity surveys. These planets are gas giants and the systems
are only stable when protected by a resonance. Additionally the Kepler mission
has detected at least 4 strong candidate planetary systems with a period ratio
close to 4:3.
  This paper investigates traditional dynamical scenarios for the formation of
these systems. We systematically study migration scenarios with both N-body and
hydro-dynamic simulations. We investigate scenarios involving the in-situ
formation of two planets in resonance. We look at the results from finely tuned
planet-planet scattering simulations with gas disk damping. Finally, we
investigate a formation scenario involving isolation-mass embryos.
  Although the combined planet-planet scattering and damping scenario seems
promising, none of the above scenarios is successful in forming enough systems
in 4:3 resonance with planetary masses similar to the observed ones. This is a
negative result but it has important implications for planet formation.
Previous studies were successful in forming 2:1 and 3:2 resonances. This is
generally believed to be evidence of planet migration. We highlight the main
differences between those studies and our failure in forming a 4:3 resonance.
We also speculate on more exotic and complicated ideas. These results will
guide future investigators toward exploring the above scenarios and alternative
mechanisms in a more general framework.",1204.0974v2
2012-04-12,Kondo effect of an adatom in graphene and its scanning tunneling spectroscopy,"We study the Kondo effect of a single magnetic adatom on the surface of
graphene. It was shown that the unique linear dispersion relation near the
Dirac points in graphene makes it more easy to form the local magnetic moment,
which simply means that the Kondo resonance can be observed in a more wider
parameter region than in the metallic host. The result indicates that the Kondo
resonance indeed can form ranged from the Kondo regime, to the mixed valence,
even to the empty orbital regime. While the Kondo resonance displays as a sharp
peak in the first regime, it has a peak-dip structure and/or an anti-resonance
in the remaining two regimes, which result from the Fano resonance due to the
significant background leaded by dramatically broadening of the impurity level
in graphene. We also study the scanning tunneling microscopy (STM) spectra of
the adatom and they show obvious particle-hole asymmetry when the chemical
potential is tuned by the gate voltages applied to the graphene. Finally, we
explore the influence of the direct tunneling channel between the STM tip and
the graphene on the Kondo resonance and find that the lineshape of the Kondo
resonance is unaffected, which can be attributed to unusual large asymmetry
factor in graphene. Our study indicates that the graphene is an ideal platform
to study systematically the Kondo physics and these results are useful to
further stimulate the relevant experimental studies on the system.",1204.2696v1
2012-04-17,Chaos-induced enhancement of resonant multielectron recombination in highly charged ions: Statistical theory,"A statistical theory of resonant multielectron recombination based on
properties of chaotic eigenstates is developed. The level density of many-body
states increases exponentially with the number of excited electrons. When the
residual electron-electron interaction exceeds the interval between these
levels, the eigenstates (called compound states or compound resonances if these
states are in the continuum) become ""chaotic"" superpositions of large numbers
of Hartree-Fock configurational basis states. This situation takes place in
some rare-earth atoms and many open-shell multiply charged ions excited in the
process of electron recombination. Our theory describes resonant multielectron
recombination via dielectronic doorway states leading to such compound
resonances. The result is a radiative capture cross section averaged over a
small energy interval containing several compound resonances. In many cases
individual resonances are not resolved experimentally (since the interval
between them is small, e.g., $\le 1$ meV, possibly even smaller than their
radiative widths), therefore, our statistical theory should correctly describe
the experimental data. We perform numerical calculations of the recombination
cross sections for tungsten ions W$^{q+}$, $q=18$--25. The recombination rate
for W$^{20+}$ measured recently [Phys. Rev. A {\bf 83}, 012711 (2011)] is
$10^3$ greater than the direct radiative recombination rate at low energies,
and our result for W$^{20+}$ agrees with the measurements.",1204.3707v1
2012-04-20,Contribution of Acoustic Losses in the Quality Factor of a Micromechanical Resonator,"A semi-analytical study of the acoustic radiation losses associated with
various transverse vibration modes of a micromechanical (MEMS) annular
resonator is presented. The quality factor, Q, of such resonators is of
interest in many applications and depends on structural geometry, interaction
with the external environment, and the encapsulation method. Resonators with at
least one surface exposed to air can display losses through acoustic radiation
even at micro meter dimensions. Published experimental results suggest the
dominance of acoustic losses in the Q of a MEMS drum resonator. In this study,
a well established mathematical techniques to analytically model resonator
vibration modes and fluid-structure interaction are used, and a semi-analytical
procedure for computing Q due to acoustic radiation losses, Qac, in any
vibrational mode outlined. Present technique includes calculation of the exact
mode shape and its utilization in computing Qac. The dependence of Qac on the
first 15 mode shapes is computed. Results are compared for the lowest 2 modes
of a solid circular resonator using exact mode shapes to those of Lamb's
approximate mode shapes. Comparison to published experimental results validates
the predictive utility of the technique, especially for higher modes where
acoustic radiation seems to be the dominant constituent of Q.",1204.4701v2
2014-06-11,Tunable coupled-mode dispersion compensation and its application to on-chip resonant four-wave mixing,"We propose and demonstrate localized mode coupling as a viable dispersion
engineering technique for phase-matched resonant four-wave mixing (FWM). We
demonstrate a dual-cavity resonant structure that employs coupling-induced
frequency splitting at one of three resonances to compensate for cavity
dispersion, enabling phase-matching. Coupling strength is controlled by thermal
tuning of one cavity enabling active control of the resonant
frequency-matching. In a fabricated silicon microresonator, we show an 8 dB
enhancement of seeded FWM efficiency over the non-compensated state. The
measured four-wave mixing has a peak wavelength conversion efficiency of -37.9
dB across a free spectral range (FSR) of 3.334 THz ($\sim$27 nm). Enabled by
strong counteraction of dispersion, this FSR is, to our knowledge, the largest
in silicon to demonstrate FWM to date. This form of mode-coupling-based, active
dispersion compensation can be beneficial for many FWM-based devices including
wavelength converters, parametric amplifiers, and widely detuned correlated
photon-pair sources. Apart from compensating intrinsic dispersion, the proposed
mechanism can alternatively be utilized in an otherwise dispersionless
resonator to counteract the detuning effect of self- and cross-phase modulation
on the pump resonance during FWM, thereby addressing a fundamental issue in the
performance of light sources such as broadband optical frequency combs.",1406.2750v2
2015-11-08,Bifurcations of lunisolar secular resonances for space debris orbits,"Using bifurcation theory, we study the secular resonances induced by the Sun
and Moon on space debris orbits around the Earth. In particular, we concentrate
on a special class of secular resonances, which depend only on the debris'
orbital inclination. This class is typically subdivided into three distinct
types of secular resonances: those occurring at the critical inclination, those
corresponding to polar orbits, and a third type resulting from a linear
combination of the rates of variation of the argument of perigee and the
longitude of the ascending node.
  The model describing the dynamics of space debris includes the effects of the
geopotential, as well as the Sun's and Moon's attractions, and it is defined in
terms of suitable action-angle variables. We consider the system averaged over
both the mean anomaly of the debris and those of the Sun and Moon. Such
multiply-averaged Hamiltonian is used to study the lunisolar resonances which
depend just on the inclination.
  Borrowing the technique from the theory of bifurcations of Hamiltonian normal
forms, we study the birth of periodic orbits and we determine the energy
thresholds at which the bifurcations of lunisolar secular resonances take
place. This approach gives us physically relevant information on the existence
and location of the equilibria, which help us to identify stable and unstable
regions in the phase space. Besides their physical interest, the study of
inclination dependent resonances offers interesting insights from the dynamical
point of view, since it sheds light on different phenomena related to
bifurcation theory.",1512.02178v2
2016-05-23,Electron doping evolution of the neutron spin resonance in NaFe$_{1-x}$Co$_{x}$As,"Neutron spin resonance, a collective magnetic excitation coupled to
superconductivity, is one of the most prominent features shared by a broad
family of unconventional superconductors including copper oxides, iron
pnictides, and heavy fermions. In this work, we study the doping evolution of
the resonances in NaFe$_{1-x}$Co$_x$As covering the entire superconducting
dome. For the underdoped compositions, two resonance modes coexist. As doping
increases, the low-energy resonance gradually loses its spectral weight to the
high-energy one but remains at the same energy. By contrast, in the overdoped
regime we only find one single resonance, which acquires a broader width in
both energy and momentum, but retains approximately the same peak position even
when $T_c$ drops by nearly a half compared to optimal doping. These results
suggest that the energy of the resonance in electron overdoped
NaFe$_{1-x}$Co$_x$As is neither simply proportional to $T_c$ nor the
superconducting gap, but is controlled by the multi-orbital character of the
system and doped impurity scattering effect.",1605.06890v1
2016-08-09,Polarons and Molecules in a Fermi Gas with Orbital Feshbach Resonance,"We study the impurity problem in a gas of $^{173}$Yb atoms near the recently
discovered orbital Feshbach resonance. In an orbital Feshbach resonance, atoms
in the electronic ground state $^1S_0$ interact with those in the long-lived
excited $^3P_0$ state with magnetically tunable interactions. We consider an
impurity atom with a given hyperfine spin in the $^3P_0$ state interacting with
a single-component Fermi sea of atoms in the ground $^1S_0$ manifold. Close to
the orbital Feshbach resonance, the impurity can induce collective
particle-hole excitations out of the Fermi sea, which can be regarded as the
polaron state. While as tuning toward the BEC regime of the resonance, a
molecular state becomes the ground state of the system. We show that a polaron
to molecule transition exists in $^{173}$Yb atoms close to the orbital Feshbach
resonance. Furthermore, due to the spin-exchange nature of the orbital Feshbach
resonance, the formation of both the polaron and the molecule involve
spin-flipping processes with interesting density distributions among the
relevant hyperfine spin states. We show that the polaron to molecule transition
can be detected using Raman spectroscopy.",1608.02744v2
2016-08-23,Coupling ideality of integrated planar high-Q microresonators,"Chipscale microresonators with integrated planar optical waveguides are
useful building blocks for linear, nonlinear and quantum optical devices. Loss
reduction through improving fabrication processes has resulted in several
integrated micro resonator platforms attaining quality (Q) factors of several
millions. However only few studies have investigated design-dependent losses,
especially with regard to the resonator coupling section. Here we investigate
design-dependent parasitic losses, described by the coupling ideality, of the
commonly employed microresonator design consisting of a microring resonator
waveguide side-coupled to a straight bus waveguide. By systematic
characterization of multi-mode high-Q silicon nitride microresonator devices,
we show that this design can suffer from low coupling ideality. By performing
full 3D simulations to numerically investigate the resonator to bus waveguide
coupling, we identify the coupling to higher-order bus waveguide modes as the
dominant origin of parasitic losses which lead to the low coupling ideality.
Using suitably designed bus waveguides, parasitic losses are mitigated, and a
nearly unity ideality and strong overcoupling (i.e. a ratio of external
coupling to internal resonator loss rate > 9) are demonstrated. Moreover we
find that different resonator modes can exchange power through the coupler,
which therefore constitutes a mechanism that induces modal coupling, a
phenomenon known to distort resonator dispersion properties. Our results
demonstrate the potential for significant performance improvements of
integrated planar microresonators, achievable by optimized coupler designs.",1608.06607v1
2016-08-26,Strain-induced spin resonance shifts in silicon devices,"In spin-based quantum information processing devices, the presence of control
and detection circuitry can change the local environment of a spin by
introducing strain and electric fields, altering its resonant frequencies.
These resonance shifts can be large compared to intrinsic spin line-widths and
it is therefore important to study, understand and model such effects in order
to better predict device performance. Here we investigate a sample of bismuth
donor spins implanted in a silicon chip, on top of which a superconducting
aluminium micro-resonator has been fabricated. The on-chip resonator provides
two functions: first, it produces local strain in the silicon due to the larger
thermal contraction of the aluminium, and second, it enables sensitive electron
spin resonance spectroscopy of donors close to the surface that experience this
strain. Through finite-element strain simulations we are able to reconstruct
key features of our experiments, including the electron spin resonance spectra.
Our results are consistent with a recently discovered mechanism for producing
shifts of the hyperfine interaction for donors in silicon, which is linear with
the hydrostatic component of an applied strain.",1608.07346v3
2017-06-20,Scattering processes and resonances from lattice QCD,"The vast majority of hadrons observed in nature are not stable under the
strong interaction, rather they are resonances whose existence is deduced from
enhancements in the energy dependence of scattering amplitudes. The study of
hadron resonances offers a window into the workings of quantum chromodynamics
(QCD) in the low-energy non-perturbative region, and in addition, many probes
of the limits of the electroweak sector of the Standard Model consider
processes which feature hadron resonances. From a theoretical standpoint, this
is a challenging field: the same dynamics that binds quarks and gluons into
hadron resonances also controls their decay into lighter hadrons, so a complete
approach to QCD is required. Presently, lattice QCD is the only available tool
that provides the required non-perturbative evaluation of hadron observables.
In this article, we review progress in the study of few-hadron reactions in
which resonances and bound-states appear using lattice QCD techniques. We
describe the leading approach which takes advantage of the periodic finite
spatial volume used in lattice QCD calculations to extract scattering
amplitudes from the discrete spectrum of QCD eigenstates in a box. We explain
how from explicit lattice QCD calculations, one can rigorously garner
information about a variety of resonance properties, including their masses,
widths, decay couplings, and form factors. The challenges which currently limit
the field are discussed along with the steps being taken to resolve them.",1706.06223v1
2017-06-20,Transition of EMRIs through resonance: corrections to higher order in the on-resonance flux modification,"Extreme mass ratio in-spirals (EMRIs) are candidate events for gravitational
wave detection in the millihertz range (by detectors like LISA and eLISA).
These events involve a stellar-mass black hole, or a similar compact object,
descending in the gravitational field of a supermassive black hole, eventually
merging with it. Properties of the in-spiralling trajectory away from resonance
are well known and have been studied extensively, however little is known about
the behaviour of these binary systems at resonance, when the radial and lateral
frequencies of the orbit become commensurate. We describe the two existing
models, the instantaneous frequency approach used by Gair, Bender, and Yunes,
and the standard two timescales approach implemented by Flanagan and Hinderer.
In both cases, the exact treatment depends on the modelling of the
gravitational self-force, which is currently not available. We extend the
results in Gair, Bender and Yunes to higher order in the on-resonance flux
modification, and argue that the instantaneous frequency approach is also a
valid treatment of the resonance problem. The non-linear differential equations
which arise in treating resonances are interesting from a mathematical view
point. We present our algorithm for perturbative solutions and the results to
third order in the infinitesimal parameter, and discuss the scope of this
approach.",1706.06639v3
2017-06-21,Microwave photon generation in a doubly tunable superconducting resonator,"We have developed and tested a doubly tunable resonator, with the intention
to simulate fast motion of the resonator boundaries in real space. Our device
is a superconducting coplanar-waveguide half-wavelength microwave resonator,
with fundamental resonant frequency ~5 GHz. Both of its ends are terminated by
dc-SQUIDs, which serve as magnetic-flux-controlled inductances. Applying a flux
to either SQUID allows tuning of the resonant frequency by approximately 700
MHz. By using two separate on-chip magnetic-flux lines, we modulate the SQUIDs
with two tones of equal frequency, close to twice that of the resonator's
fundamental mode. We observe photon generation, at the fundamental frequency,
above a certain pump amplitude threshold. By varying the relative phase of the
two pumps we are able to control the photon generation threshold, in good
agreement with a theoretical model for the modulation of the boundary
conditions. At the same time, some of our observations deviate from the
theoretical predictions, which we attribute to parasitic couplings, resulting
in current driving of the SQUIDs.",1706.06821v1
2017-10-31,Resonant Photon-Exciton Coupling in All-Semiconductor Heterostructures Composed of Silicon Nanosphere and Monolayer WS2,"Tailoring and enhancing the interaction between light and matter is of great
importance for both fundamental researches and future photonic and
optoelectronic applications. Due to their high exciton oscillator strength and
large exciton binding energy, two-dimensional atomic semiconducting transition
metal dichalcogenides have recently emerged as an excellent platform for the
strong photon-exciton interaction by integrating with optically resonant
cavities. Here, we propose an all-semiconductor system composed of individual
silicon nanospheres and monolayer WS2 and investigate the resonance coupling
between these two constituents. By coating the silicon nanospheres with
monolayer WS2, we demonstrate the strong resonance coupling between the
magnetic dipole mode and A-exciton, evidenced by an anticrossing behavior in
the scattering energy diagram with a Rabi splitting of 77 meV. Compared with
the plasmonic analogues, the resonance coupling in all-semiconductor
heterostructure is much stronger and less sensitive to the spacing between the
silicon nanosphere core and WS2 shell. When the silicon nanospheres are placed
onto the WS2 monolayer with a point contact, resonance coupling manifested by
the quenching dips in the scattering spectra can also be observed at ambient
conditions, which involves only a few excitons. Finally, resonance coupling in
the all-semiconductor heterostructure can be active controlled by temperature
scanning. Our findings suggest that this all-semiconductor heterostructure can
be exploited for future on-chip nanophotonics associated with strong
light-matter interactions.",1710.11447v1
2017-12-01,Interplay of activation kinetics and the derivative conductance determines resonance properties of neurons,"In a neuron with hyperpolarization activated current ($I_h$), the correct
input frequency leads to an enhancement of the output response. This behavior
is known as resonance and is well described by the neuronal impedance. In a
simple neuron model we derive equations for the neuron's resonance and we link
its frequency and existence with the biophysical properties of $I_h$. For a
small voltage change, the component of the ratio of current change to voltage
change ($dI/dV$) due to the voltage-dependent conductance change ($dg/dV$) is
known as derivative conductance ($G_h^{Der}$). We show that both $G_h^{Der}$
and the current activation kinetics (characterized by the activation time
constant $\tau_h$) are mainly responsible for controlling the frequency and
existence of resonance. The increment of both factors ($G_h^{Der}$ and
$\tau_h$) greatly contributes to the appearance of resonance. We also
demonstrate that resonance is voltage dependent due to the voltage dependence
of $G_h^{Der}$. Our results have important implications and can be used to
predict and explain resonance properties of neurons with the $I_h$ current.",1712.00306v3
2017-12-26,Optimal Orientations of Quartz Crystals for Bulk Acoustic Wave Resonators with the Consideration of Thermal Properties,"Piezoelectric crystals are widely used for acoustic wave resonators of
different functioning modes and types including BAW and SAW. It is well-known
that only some special orientations of crystals will exhibit desirable
properties such as mode couplings, thermal sensitivity, acceleration
sensitivity, and others that are important in design and applications of
resonators. With extensive studies on physical properties in last decades and
increasing industrial needs of novel products, it is necessary to comb the
known knowledge of quartz crystal material for novel orientations and better
products as agendas in the industry. With known material properties like
elastic, piezoelectric, dielectric, and thermal constants, we can establish the
relationships between vibrations and bias fields such as temperature to ensure
a resonator immunizing from excessive response to changes causing significant
degradation of resonator properties and performances. Since the theoretical
framework of wave propagation in piezoelectric solids is known, we need to use
the existing data and results for the validation of current orientations in
actual products. The agreement will give us needed confidence of the theory and
analytical procedures. Through rotations, we calculated physical properties as
functions of angles and bias fields, enabling the calculation of resonator
properties for the identification of optimal cuts. Such a procedure can also be
applied to similar crystals for a careful examination of possible orientations
to maximize the potential use of materials in acoustic wave resonators.",1712.09187v1
2018-01-10,Cadmium Resonance Parameters from Neutron Capture and Transmission Measurements at the RPI LINAC,"Cadmium has been used historically as an important component of integral
experiments because of its high thermal neutron absorption cross section.
Correct interpretation of such experiments depends on accurate differential
neutron cross section measurements. The 60 MeV electron accelerator at the
Gaerttner LINAC Center was used to generate neutrons for neutron capture and
total cross section measurements of natural Cd. Measurements were performed in
the thermal and epithermal resonance range with sample thicknesses ranging from
1 x 10-4 to 4 x 10-2 atoms per barn. A full resonance region analysis was
performed in order to determine the thermal cross sections and resonance
integrals of the cadmium isotopes. The Bayesian R-Matrix code SAMMY 8.0 was
used to shape fit the data and extract the resonance parameters. Resonance
parameter and cross section uncertainties were determined from their primary
components: transmission background, capture normalization, experimental
resolution function, burst width, sample thickness, and counting statistics.
The experiments were analyzed for consistency within the measured capture and
transmission using multiple sample thicknesses. Results are compared to
previously published measurements and evaluated nuclear libraries. No major
changes to the thermal cross section or the first resonance in Cd113 were
identified from the consensus achieved from measurements and evaluations over
the past decade.",1801.03424v1
2018-09-11,Magnetic field resilient superconducting coplanar waveguide resonators for hybrid cQED experiments,"Superconducting coplanar waveguide resonators that can operate in strong
magnetic fields are important tools for a variety of high frequency
superconducting devices. Magnetic fields degrade resonator performance by
creating Abrikosov vortices that cause resistive losses and frequency
fluctuations, or suppressing superconductivity entirely. To mitigate these
effects we investigate lithographically defined artificial defects in
resonators fabricated from NbTiN superconducting films. We show that by
controlling the vortex dynamics the quality factor of resonators in
perpendicular magnetic fields can be greatly enhanced. Coupled with the
restriction of the device geometry to enhance the superconductors critical
field, we demonstrate stable resonances that retain quality factors $\simeq
10^5$ at the single photon power level in perpendicular magnetic fields up to
$B_\perp \simeq$ 20 mT and parallel magnetic fields up to $B_\parallel \simeq$
6 T. We demonstrate the effectiveness of this technique for hybrid systems by
integrating an InSb nanowire into a field resilient superconducting resonator,
and use it to perform fast charge readout of a gate defined double quantum dot
at $B_\parallel =$ 1 T.",1809.03932v1
2018-09-30,Stalling of Globular Cluster Orbits in Dwarf Galaxies,"We apply the Tremaine-Weinberg theory of dynamical friction to compute the
orbital decay of a globular cluster (GC), on an initially circular orbit inside
a cored spherical galaxy with isotropic stellar velocities. The retarding
torque on the GC, T(rp) < 0 , is a function of its orbital radius rp . The
torque is exerted by stars whose orbits are resonant with the GC's orbit, and
given as a sum over the infinitely many possible resonances by the Lynden-Bell
Kalnajs (LBK) formula. We calculate the LBK torque T(rp) and determine rp(t),
for a GC of mass Mp = 2 x 10^5 M_sun and an Isochrone galaxy of core mass Mc =
4 x 10^8 M_sun and core radius b = 1000pc. (i) When rp > 300 pc many strong
resonances are active and, as expected, T = T_C , the classical Chandrasekhar
torque. (ii) For rp < 300 pc, T comes mostly from stars nearly co-rotating with
the GC, trailing or leading it slightly; Trailing resonances exert stronger
torques. (iii) As rp decreases the number and strength of resonances drop, so
|T| also decreases, with |T| < 10^{-2} |T_C| at rp = r* = (Mp/Mc)^{1/5} b = 220
pc , a characteristic `filtering' radius. (iv) Many resonances cease to exist
inside r* ; this includes all Leading and low-order Trailing ones. (v) The
higher-order Trailing resonances inside r* are very weak, with |T| < 10^{-4}
|T_C| at rp = 150 pc. (vi) Inspiral times for rp(t) to decay from 300 pc to r*
far exceed 10 Gyr.",1810.00369v2
2019-06-17,Applying the resonant-state expansion to realistic materials with frequency dispersion,"The dispersive resonant-state expansion, developed for an accurate
calculation of the resonant states in open optical systems with frequency
dispersion, is applied here to realistic materials, such as metallic
nanoparticles and semiconductor microspheres. The material permittivity is
determined by fitting the measured indices of refraction and absorption with a
generalized Drude-Lorentz model containing a number of poles in the complex
frequency plane. Each Drude or Lorentz pole generates an infinite series of
resonant states. Furthermore, for small nanoparticles, each of these poles
produces a distinct surface plasmon polariton mode. The evolution of these
multiple surface modes with increasing radius traces the transition from the
electrostatic limit to significant retardation and radiation. Treating the
optical phonon range in a semiconductor microsphere, a reststrahlen band
separating the resonant states is found. Considering a small energy range
around the semiconductor band gap, the transition from absorption to gain is
described by inverting the Lorentz pole weight, which results in the formation
of lasing resonant states. Interestingly, the series of resonant states
converging towards the absorption pole from the lower frequency side reshapes
for a gain pole into a clockwise loop approaching the pole from the higher
frequency side, being separated from a series spanning from low to high
frequencies and containing the lasing modes.",1906.07007v1
2019-06-24,Magnetic and Electric Mie-Exciton Polaritons in Silicon Nanodisks,"Light-matter interactions at the nanoscale constitute a fundamental
ingredient for engineering applications in nanophotonics and quantum optics. To
this regard electromagnetic Mie resonances excited in high-refractive index
dielectric nanoparticles have recently attracted interest because of their
lower losses and better control over the scattering patterns compared to their
plasmonic metallic counterparts. The emergence of several resonances in those
systems results in an overall high complexity, where the electric and magnetic
dipoles have significant overlap in the case of spherical symmetry, thus
concealing the contributions of each resonance separately. Here we show,
experimentally and theoretically, the emergence of strong light-matter coupling
between the magnetic and electric-dipole resonances of individual silicon
nanodisks coupled to a J-aggregated organic semiconductor resonating at optical
frequencies, evidencing how the different properties of the two resonances
results in two different coupling strengths. The energy splittings observed are
of the same order of magnitude as in similar plasmonic systems, thus confirming
dielectric nanoparticles as promising alternatives for localized strong
coupling studies. The coupling of both the electric and magnetic dipole
resonances can offer interesting possibilities for the control of directional
light scattering in the strong-coupling regime and the dynamic tuning of
nanoscale light-matter coupled states by external fields.",1906.09898v1
2019-09-09,Ferromagnetic resonance assisted optomechanical magnetometer,"The resonant enhancement of mechanical and optical interaction in
optomechanical cavities enables their use as extremely sensitive displacement
and force detectors. In this work we demonstrate a hybrid magnetometer that
exploits the coupling between the resonant excitation of spin waves in a
ferromagnetic insulator and the resonant excitation of the breathing mechanical
modes of a glass microsphere deposited on top. The interaction is mediated by
magnetostriction in the ferromagnetic material and the consequent mechanical
driving of the microsphere. The magnetometer response thus relies on the
spectral overlap between the ferromagnetic resonance and the mechanical modes
of the sphere, leading to a peak sensitivity better than 900 pT Hz$^{-1/2}$ at
206 MHz when the overlap is maximized. By externally tuning the ferromagnetic
resonance frequency with a static magnetic field we demonstrate sensitivity
values at resonance around a few nT Hz$^{-1/2}$ up to the GHz range. Our
results show that our hybrid system can be used to build high-speed sensor of
oscillating magnetic fields.",1909.03924v4
2019-10-16,Ultra-high frequency magnetic resonance through strain-spin coupling in perpendicular magnetic multi-layers,"The interaction between strain and spin has received intensive attention in
the scientific community due to its abundant physical phenomena and huge
technological impact. Until now, there is no experimental report on ultra-high
frequency magnetic resonance through the strain-spin coupling for any
technologically relevant perpendicular magnetic material. Here we report the
experimental detection of the acoustic strain waves that have a response time
on the order of 10 picoseconds in perpendicular magnetic [Co/Pd]n multilayers
via a femtosecond laser pulse excitation. Through direct measurements of
acoustic strain waves, we observe an ultra-high frequency magnetic resonance up
to 60 GHz in [Co/Pd]n multilayers. We further report a theoretical model of the
strain-spin interaction. Our model reveals that the energy could be transferred
efficiently from the strain to the spins and well explains the existence of a
steady resonance state through exciting the spin system. The physical origins
of the resonance between strain waves and magnetic precession and the requested
conditions for obtaining magnetic resonance within thin magnetic films have
also been discussed after thorough analysis. These combined results point out a
potential pathway to enable an extremely high frequency (EHF) magnetic
resonance through the strain-spin coupling.",1910.07147v2
2020-01-21,Modulation theory and resonant regimes for dispersive shock waves in nematic liquid crystals,"A full analysis of all regimes for optical dispersive shock wave (DSW)
propagation in nematic liquid crystals is undertaken. These dispersive shock
waves are generated from step initial conditions for the optical field and are
resonant in that linear diffractive waves are in resonance with the DSW,
resulting in a resonant linear wavetrain propagating ahead of it. It is found
that there are six regimes, which are distinct and require different solution
methods. In previous studies, the same solution method was used for all
regimes, which does not yield solutions in full agreement with numerical
solutions. Indeed, the standard DSW structure disappears for sufficiently large
initial jumps. Asymptotic theory, approximate methods or Whitham modulation
theory are used to find solutions for these resonant dispersive shock waves in
a given regime. The solutions are found to be in excellent agreement with
numerical solutions of the nematic equations in all regimes. It is found that
for small initial jumps, the resonant wavetrain is unstable, but that it
stabilises above a critical jump height. It is additionally found that the DSW
is unstable, except for small jump heights for which there is no resonance and
large jump heights for which there is no standard DSW structure.",2001.07647v1
2020-01-28,Photon induced K$Λ$ production on the proton in the low energy region,"The associated photoproduction of $K\Lambda$ from the proton in the low
energy region is studied using an isobar model in which the non-resonant
contributions are obtained from the non-linear sigma model with chiral SU(3)
symmetry which predicts, in a natural way, the contact term with its coupling
strength along with the coupling strengths of the various Born terms predicted
by the non-linear sigma model. The present model is an extension of the
non-linear sigma model with chiral SU(2) symmetry, used earlier to study the
photo, electro, and neutrino productions of pions. In the resonance sector, the
contributions from the well established nucleon resonances ($R$) in the $s$
channel, the hyperon resonances ($Y^{*}$) in the $u$ channel, and the kaon
resonances ($K^{*}$ and $K_{1}$) in the $t$ channel having spin $\le
\frac{3}{2}$ and mass $<2$ GeV with a significant branching ratio in $K\Lambda$
decay mode, have been considered. The strong and electromagnetic couplings of
the $s$ channel nucleon resonances are taken from experiments while the
couplings for the resonances in the $t$ and $u$ channels are fitted to
reproduce the current data on the associated photoproduction of $K\Lambda$ in
this energy region. The numerical results are presented for the total and
differential cross sections and are compared with the available experimental
data from CLAS and SAPHIR as well as with some of the recent theoretical
models.",2001.10201v2
2020-04-28,Evidence for the $N'(1720)3/2^+$ Nucleon Resonance from Combined Studies of CLAS $π^+π^-p$ Photo- and Electroproduction Data,"The analysis of the nine 1-fold differential cross sections for the
$\gamma_{r,v} p \to \pi^+\pi^-p$ photo- and electroproduction reactions
obtained with the CLAS detector at Jefferson Laboratory was carried out with
the goal to establish the contributing resonances in the mass range from
1.6~GeV to 1.8~GeV. In order to describe the photo- and electroproduction data
with $Q^2$-independent resonance masses and hadronic decay widths in the $Q^2$
range below 1.5~GeV$^2$, it was found that an $N'(1720)3/2^+$ state is required
in addition to the already well-established nucleon resonances. This work
demonstrates that the combined studies of $\pi^+\pi^-p$ photo- and
electroproduction data are vital for the observation of this resonance. The
contributions from the $N'(1720)3/2^+$ state and the already established
$N(1720)3/2^+$ state with a mass of 1.745~GeV are well separated by their
different hadronic decays to the $\pi \Delta$ and $\rho p$ final states and the
different $Q^2$-evolution of their photo-/electroexcitation amplitudes. The
$N'(1720)3/2^+$ state is the first recently established baryon resonance for
which the results on the $Q^2$-evolution of the photo-/electrocouplings have
become available. These results are important for the exploration of the nature
of the ``missing'' baryon resonances.",2004.13531v1
2020-04-30,Tilting Uranus: Collisions versus Spin--Orbit Resonance,"In this paper, we investigate whether Uranus's 98$^{\circ}$ obliquity was a
by-product of a secular spin-orbit resonance assuming that the planet
originated closer to the Sun. In this position, Uranus's spin precession
frequency is fast enough to resonate with another planet located beyond Saturn.
Using numerical integration, we show that resonance capture is possible in a
variety of past solar system configurations, but that the timescale required to
tilt the planet to 90$^{\circ}$ is of the order $\sim\!10^{8}$ yr -- a timespan
that is uncomfortably long. A resonance kick could tilt the planet to a
significant 40$^{\circ}$ in $\sim\!10^{7}$ yr only if conditions were ideal. We
also revisit the collisional hypothesis for the origin of Uranus's large
obliquity. We consider multiple impacts with a new collisional code that builds
up a planet by summing the angular momentum imparted from impactors. Because
gas accretion imparts an unknown but likely large part of the planet's spin
angular momentum, we compare different collisional models for tilted, untilted,
spinning, and nonspinning planets. We find that a 1 $M_{\oplus}$ strike is
sufficient to explain the planet's current spin state, but that two
$0.5\,M_{\oplus}$ collisions produce better likelihoods. Finally, we
investigate hybrid models and show that resonances must produce a tilt of at
least $\sim\!40^{\circ}$ for any noticeable improvements to the collision
model. Because it is difficult for spin-orbit resonances to drive Uranus's
obliquity to 98$^{\circ}$ even under these ideal conditions, giant impacts seem
inescapable.",2004.14913v3
2020-12-07,Formation of multiple-planet systems in resonant chains around M dwarfs,"Recent observations have revealed the existence of multiple-planet systems
composed of Earth-mass planets around late M dwarfs. Most of their orbits are
close to commensurabilities, which suggests that planets were commonly trapped
in resonant chains in their formation around low-mass stars. We investigate the
formation of multiple-planet systems in resonant chains around low-mass stars.
A time-evolution model of the multiple-planet formation via pebble accretion in
the early phase of the disk evolution is constructed based on the formation
model for the TRAPPIST-1 system by Ormel et al. (2017). Our simulations show
that knowing the protoplanet appearance timescale is important for determining
the number of planets and their trapped resonances: as the protoplanet
appearance timescale increases, fewer planets are formed, which are trapped in
more widely separated resonances. We find that there is a range of the
protoplanet appearance timescale for forming the stable multiple-planet systems
in resonant chains. This range depends on the stellar mass and disk size. We
suggest that the protoplanet appearance timescale is a key parameter for
studying the formation of multiple-planet systems with planets in resonant
chains around low-mass stars. The composition of the planets in our model is
also discussed.",2012.03469v1
2020-12-30,Nonlinear effects in locally-resonant nanostrip phononic metasurface at GHz frequencies,"In this paper, we report on the observation of nonlinear effects in a
nanostrip phononic metasurface (NPM) that enable the tuning of resonance
frequencies at 1.42 GHz. The NPM resonator made of periodic nanostrip array is
fabricated on a lithium niobate substrate. Each of the nanostrip is 250-nm wide
and is made of 680-nm-thick SiO2 layer stacking on 50-nm Al metal electrodes.
Finite element analysis reveals that the device operates in a vertically
polarized (compression) mode with substantial acoustic energy confined in the
nanostrips, leading to a local resonance at low acoustic velocity. Due to the
nonlinearity, the resonance frequency of the device decreases quadratically
with the increase of stimulation power from 10 to 30 dBm. The underlying
mechanism of the nonlinearity is found to be the power-dependent coupling of
the adjacent nanostrips. This coupling induces softening of the substrate
surface region, which reduces the acoustic velocity and hence the bulk
radiation. As a result, the quality factor of the NPM resonator is found to
improve with the increase of stimulation power. The power-dependent coupling of
nanostrips in the NPM resonator demonstrates a reliable method for the
realization of nonlinearity in phononic metasurfaces, which would significantly
enrich the mechanisms for the manipulation of surface acoustic waves at high
frequencies.",2012.15314v1
2021-01-02,Acoustic radiation-free surface phononic crystal resonator for in-liquid low-noise gravimetric detection,"Acoustic wave resonators are promising for gravimetric biosensing. However,
they generally suffer from strong acoustic radiation in liquid, which limits
their quality factor and increases their frequency noise. This article presents
an acoustic-radiation-free gravimetric biosensor based on a locally-resonant
surface phononic crystal (SPC) consisting of periodic high aspect ratio
electrodes to ad-dress the above issue. The acoustic wave generated in the SPC
is slower than the sound wave in water, hence preventing acoustic propagation
in the fluid and resulting in energy confinement near the electrode surface.
This energy confinement results in a significant quality factor improvement and
thus reduces the frequency noise. The proposed SPC resonator is numerically
studied by finite element analysis and experimentally implemented by an
electroplating based fabrication process. Experimental results show that the
SPC resonator exhibits an in-liquid quality factor 15 times higher than a
conventional Rayleigh wave resonator with a similar operating frequency. The
proposed radiation suppression method using SPC can also be applied in other
types of acoustic wave resonators. It can thus serve as a general technique for
boosting the in-liquid quality factor and the sensing performance of many
acoustic biosensors.",2101.00504v2
2021-01-25,Kerr-Nonlinearity-Induced Mode-Splitting in Optical Microresonators,"The Kerr effect in optical microresonators plays an important role for
integrated photonic devices and enables third harmonic generation, four-wave
mixing, and the generation of microresonator-based frequency combs. Here we
experimentally demonstrate that the Kerr nonlinearity can split ultra-high-Q
microresonator resonances for two continuous-wave lasers. The resonance
splitting is induced by self- and cross-phase modulation and
counter-intuitively enables two lasers at different wavelengths to be
simultaneously resonant in the same microresonator mode. We develop a
pump-probe spectroscopy scheme that allows us to measure power dependent
resonance splittings of up to 35 cavity linewidths (corresponding to 52 MHz) at
10 mW of pump power. The required power to split the resonance by one cavity
linewidth is only 286${\mu}$W. In addition, we demonstrate threefold resonance
splitting when taking into account four-wave mixing and two counterpropagating
probe lasers. These Kerr splittings are of interest for applications that
require two resonances at optically controlled offsets, eg. for opto-mechanical
coupling to phonon modes, optical memories, and precisely adjustable spectral
filters.",2101.10170v1
2021-01-25,Eigenmodes and resonance vibrations of 2D nanomembranes -- Graphene and hexagonal boron-nitride,"Natural and resonant oscillations of suspended circular graphene and
hexagonal boron nitride (h-BN) membranes (single-layer sheets lying on a flat
substrate having a circular hole of radius $R$) have been simulated using
full-atomic models. Substrates formed by flat surfaces of graphite and h-BN
crystal, hexagonal ice, silicon carbide 6H-SiC and nickel surface (111) have
been used. The presence of the substrate leads to the forming of a gap at the
bottom of the frequency spectrum of transversal vibrations of the sheet. The
frequencies of natural oscillations of the membrane (oscillations localized on
the suspended section of the sheet) always lie in this gap, and the frequencies
of oscillations decrease by increasing radius of the membrane as $(R+R_i)^{-2}$
with nonezero effective increase of radius $R_i>0$. The modeling of the sheet
dynamics has shown that small periodic transversal displacements of the
substrate lead to resonant vibrations of the membranes at frequencies close to
eigenfrequencies of nodeless vibrations of membranes with a circular symmetry.
The energy distribution of resonant vibrations of the membrane has a circular
symmetry and several nodal circles, whose number $i$ coincides with the number
of the resonant frequency. The frequencies of the resonances decrease by
increasing the radius of the membrane as $(R+R_i)^{\alpha_i}$ with exponent
$\alpha_i<2$. The lower rate of resonance frequency decrease is caused by the
anharmonicity of membrane vibrations.",2101.10237v1
2021-01-28,Universal field dependence of magnetic resonance near zero frequency,"Magnetic resonance is a widely-established phenomenon that probes magnetic
properties such as magnetic damping and anisotropy. Even though the typical
resonance frequency of a magnet ranges from gigahertz to terahertz, experiments
also report the resonance near zero frequency in a large class of magnets. Here
we revisit this phenomenon by analyzing the symmetry of the system and find
that the resonance frequency ($\omega$) follows a universal power law $\omega
\varpropto |H-H_c|^p$, where $H_c$ is the critical field at which the resonance
frequency is zero. When the magnet preserves the rotational symmetry around the
external field ($H$), $p = 1$. Otherwise, $p=1/2$. The magnon excitations are
gapped above $H_c$, gapless at $H_c$ and gapped again below $H_c$. The zero
frequency is often accompanied by a reorientation transition in the
magnetization. For the case that $p=1/2$, this transition is described by a
Landau theory for second-order phase transitions. We further show that the spin
current driven by thermal gradient and spin-orbit effects can be significantly
enhanced when the resonance frequency is close to zero, which can be measured
electrically by converting the spin current into electric signals. This may
provide an experimentally accessible way to characterize the critical field.
Our findings provide a unified understanding of the magnetization dynamics near
the critical field, and may, furthermore, inspire the study of magnon transport
near magnetic transitions.",2101.12292v1
2017-05-23,Higgs-photon resonances,"We study models that produce a Higgs boson plus photon ($h^0 \gamma$)
resonance at the LHC. When the resonance is a $Z'$ boson, decays to $h^0
\gamma$ occur at one loop. If the $Z'$ boson couples at tree-level to quarks,
then the $h^0 \gamma$ branching fraction is typically of order $10^{-5}$ or
smaller. Nevertheless, there are models that would allow the observation of $Z'
\to h^0 \gamma$ at $\sqrt{s} = 13$ TeV with a cross section times branching
fraction larger than 1 fb for a $Z'$ mass in the 200--450 GeV range, and larger
than 0.1 fb for a mass up to 800 GeV. The 1-loop decay of the $Z'$ into lepton
pairs competes with $h^0 \gamma$, even if the $Z'$ couplings to leptons vanish
at tree level. We also present a model in which a $Z'$ boson decays into a
Higgs boson and a pair of collimated photons, mimicking an $h^0 \gamma$
resonance. In this model, the $h^0 \gamma$ resonance search would be the
discovery mode for a $Z'$ as heavy as 2 TeV. When the resonance is a scalar,
although decay to $h^0 \gamma$ is forbidden by angular momentum conservation,
the $h^0$ plus collimated photons channel is allowed. We comment on prospects
of observing an $h^0 \gamma$ resonance through different Higgs decays, on
constraints from related searches, and on models where $h^0$ is replaced by a
nonstandard Higgs boson.",1705.08433v1
2017-11-14,Modelling stochastic resonance in humans: the influence of lapse rate,"Adding noise to a sensory signal generally decreases human performance.
However noise can improve performance too, due to a process called stochastic
resonance (SR). This paradoxical effect may be exploited in psychophysical
experiments, to provide additional insights into how the sensory system deals
with noise. Here, I develop a model for stochastic resonance to study the
influence of noise on human perception, in which the biological parameter of
`lapse rate' was included. I show that the inclusion of lapse rate allows for
the occurrence of stochastic resonance in terms of the performance metric d'.
At the same time, I show that high levels of lapse rate cause stochastic
resonance to disappear. It is also shown that noise generated in the brain
(i.e., internal noise) may obscure any effect of stochastic resonance in
experimental settings. I further relate the model to a standard equivalent
noise model, the linear amplifier model, and show that the lapse rate can
function to scale the threshold versus noise (TvN) curve, similar to the
efficiency parameter in equivalent noise (EN) models. Therefore, lapse rate
provides a psychophysical explanation for reduced efficiency in EN paradigms.
Furthermore, I note that ignoring lapse rate may lead to an overestimation of
internal noise in equivalent noise paradigms. Overall, describing stochastic
resonance in terms of signal detection theory, with the inclusion of lapse
rate, may provide valuable new insights into how human performance depends on
internal and external noise.",1711.04950v1
2017-11-30,Frequency spectrum of an optical resonator in a curved spacetime,"The effect of gravity and proper acceleration on the frequency spectrum of an
optical resonator - both rigid or deformable - is considered in the framework
of general relativity. The optical resonator is modeled either as a rod of
matter connecting two mirrors or as a dielectric rod whose ends function as
mirrors. Explicit expressions for the frequency spectrum are derived for the
case that it is only perturbed slightly. For a deformable resonator, the
perturbation of the frequency spectrum depends on the speed of sound in the rod
supporting the mirrors. A connection is found to a relativistic concept of
rigidity when the speed of sound approaches the speed of light. In contrast,
the corresponding result for the assumption of Born rigidity is recovered when
the speed of sound becomes infinite. The results presented in this article can
be used as the basis for the description of optical and opto-mechanical systems
in a curved spacetime. We apply our results to the examples of a uniformly
accelerating resonator and an optical resonator in the gravitational field of a
small moving sphere. Our approach is not limited to weak gravitational fields,
which we exemplify by its application to the fictitious situation of an optical
resonator falling into a black hole.",1711.11320v1
2018-06-14,Modelling top partner-vector resonance phenomenology,"We have analysed the observable consequences of the interactions of spin-1
resonances coupled to the invariant fermionic currents that arise in an $SO(5)$
Composite Higgs set-up. The phenomenology entailed by such interactions is
thoroughly analysed by studying heavy vector resonances production and decay
modes in the viable resonance mass range. Additionally, the production of
double and single-composite fermion final states has been scanned along the
fermion mass scale. Such production is mediated by the SM gauge and Higgs
interactions, and also by charged and neutral vector resonances. The coupling
between the new fermions and vector resonances induces a sizeable effect in the
production rates. We use the recent 13 TeV LHC searches for vector-like quarks
to constrain our parameter space. Specifically, we explore the allowed regions
by analysing the decays of a heavy vector-like quark in the $Wb$-channel. We
conclude that generically the impact of the couplings between the spin-1 and
spin-1/2 resonances will substantially reduce the permitted regions, leading us
to test the sensitivity of the parametric dependence in the light of exotic
matter interactions.",1806.06694v3
2018-06-26,Anomalous zero-temperature magnetopolaronic blockade of resonant electron tunneling in Majorana-resonant-level single-electron transistor,"The magnetopolaronic generalization of a Majorana-resonant-level (MRL) model
is considered for a single-level vibrating quantum dot coupled to two
half-infinite $g=1/2$ Tomonaga-Luttinger liquid (TLL) leads. A qualitatively
new non-trivial formula for the effective transmission coefficient and
differential conductance for resonant magnetopolaron-assisted tunneling is
obtained under the assumption about a fermion-boson factorization of
corresponding averages. This approach is valid for the case of weak
magnetopolaronic coupling in a system. Surprisingly, it is found that despite a
supposed weakness of interaction between fermionic and bosonic subsystems in
that case, a strongly correlated electron transport in the system reveals
features of strong (and, hence, anomalous) magnetopolaronic blockade at zero
temperature if the energy of a vibrational quantum is the smallest (but
nonzero) energy parameter in the system. Such an effect should be referred to
as magnetic phase-coherent magnetopolaron-assisted resonant tunneling of
Andreev type, that originates from a special, Majorana-like, symmetry of
magnetopolaron-coupled tunnel Hamiltonian. The effect predicted in this paper
can be used as an experimental fingerprint of Majorana-resonant level situation
in single-electron transistors as well as for detection of ultra-slow
zero-point oscillations of suspended carbon nanotubes in the Majorana-resonant
level regime of electron tunneling through corresponding single-electron
transistors.",1806.10484v1
2018-07-01,Density of Resonances for Covers of Schottky Surfaces,"We investigate how bounds of resonance counting functions for Schottky
surfaces behave under transitions to covering surfaces of finite degree. We
consider the classical resonance counting function asking for the number of
resonances in large (and growing) disks centered at the origin of $\mathbb{C}$,
as well as the (fractal) resonance counting function asking for the number of
resonances in boxes near the axis of the critical exponent. For the former
counting function we provide a transfer-operator-based proof that bounding
constants can be chosen such that the transformation behavior under transition
to covers is as for the Weyl law in the case of surfaces of finite area. For
the latter counting function we deduce a bound in terms of the covering degree
and the minimal length of a periodic geodesic on the covering surface. This
yields an improved fractal Weyl upper bound. In the setting of Schottky
surfaces, these estimates refine previous results due to Guillop\'{e}--Zworski
and Guillop\'{e}--Lin--Zworski. When applied to principal congruence covers,
these results yield new estimates for the resonance counting functions in the
level aspect, which have recently been investigated by Jakobson--Naud. The
techniques used in this article are based on the thermodynamic formalism for
$L$-functions (twisted Selberg zeta functions), and twisted transfer operators.",1807.00299v2
2018-07-06,Interplay of Polarization and Time-Reversal Symmetry Breaking in Synchronously Pumped Ring Resonators,"Optically induced breaking of symmetries plays an important role in nonlinear
photonics, with applications ranging from optical switching in integrated
photonic circuits to soliton generation in ring lasers. In this work we study
for the first time the interplay of two types of spontaneous symmetry breaking
that can occur simultaneously in optical ring resonators. Specifically we
investigate a ring resonator (e.g. a fiber loop resonator or whispering gallery
microresonator) that is synchronously pumped with short pulses of light. In
this system we numerically study the interplay and transition between regimes
of temporal symmetry breaking (in which pulses in the resonator either run
ahead or behind the seed pulses) and polarization symmetry breaking (in which
the resonator spontaneously generates elliptically polarized light out of
linearly polarized seed pulses). We find ranges of pump parameters for which
each symmetry breaking can be independently observed, but also a regime in
which a dynamical interplay takes place. Besides the fundamentally interesting
physics of the interplay of different types of symmetry breaking, our work
contributes to a better understanding of the nonlinear dynamics of optical ring
cavities which are of interest for future applications including all-optical
logic gates, synchronously pumped optical frequency comb generation, and
resonator-based sensor technologies.",1807.02347v1
2018-08-09,Search for pair-produced resonances decaying to quark pairs in proton-proton collisions at $\sqrt{s} =$ 13 TeV,"A general search for the pair production of resonances, each decaying to two
quarks, is reported. The search is conducted separately for heavier resonances
(masses above 400 GeV), where each of the four final-state quarks generates a
hadronic jet resulting in a four-jet signature, and for lighter resonances
(masses between 80 and 400 GeV), where the pair of quarks from each resonance
is collimated and reconstructed as a single jet resulting in a two-jet
signature. In addition, a b-tagged selection is applied to target resonances
with a bottom quark in the final state. The analysis uses data collected with
the CMS detector at the CERN LHC, corresponding to an integrated luminosity of
35.9 fb$^{-1}$, from proton-proton collisions at a center-of-mass energy of 13
TeV. The mass spectra are analyzed for the presence of new resonances, and are
found to be consistent with standard model expectations. The results are
interpreted in the framework of $R$-parity-violating supersymmetry assuming the
pair production of scalar top quarks decaying via the hadronic coupling
$\lambda_{312}''$ or $\lambda_{323}''$, and upper limits on the cross section
as a function of the top squark mass are set. These results probe a wider range
of masses than previously explored at the LHC, and extend the top squark mass
limits in the $\widetilde{\mathrm{t}}$ $\to$ qq$'$ scenario.",1808.03124v2
2018-08-11,Increased multiplexing of superconducting microresonator arrays by post-characterization adaptation of the on-chip capacitors,"We present an interdigitated capacitor trimming technique for fine-tuning the
resonance frequency of superconducting microresonators and increasing the
multiplexing factor. We first measure the optical response of the array with a
beam mapping system to link all resonances to their physical resonators. Then a
new set of resonance frequencies with uniform spacing and higher multiplexing
factor is designed. We use simulations to deduce the lengths that we should
trim from the capacitor fingers in order to shift the resonances to the desired
frequencies. The sample is then modified using contact lithography and
re-measured using the same setup. We demonstrate this technique on a 112-pixel
aluminum lumped-element kinetic-inductance detector array. Before trimming, the
resonance frequency deviation of this array is investigated. The variation of
the inductor width plays the main role for the deviation. After trimming, the
mean fractional frequency error for identified resonators is -6.4e-4, with a
standard deviation of 1.8e-4. The final optical yield is increased from 70.5%
to 96.7% with no observable crosstalk beyond -15 dB during mapping. This
technique could be applied to other photon-sensitive superconducting
microresonator arrays for increasing the yield and multiplexing factor.",1808.03779v2
2018-08-19,A Dark Vector Resonance at CLIC,"One of the main problems in Particle Physics is to understand the origin and
nature of Dark Matter. An exciting possibility is to consider that the Dark
Matter belongs to a new complex but hidden sector. In this paper, we assume the
existence of a strongly interacting dark sector consisting on a new scalar
doublet and new vector resonances, in concordance with a model recently
proposed by our group. Since in a previous work it was found that it is very
challenging to find the new vector resonances at the LHC, here we study the
possibility of finding them at the a future Compact Linear Collider (CLIC)
running at $\sqrt{s}=3$ TeV. We consider two distinct scenarios: when the
non-standard scalars are heavy, the dark resonance is intense enough to make
its discovery possible at CLIC when the resonance mass is in the range
$[2000,3000]$ GeV. In the second scenario, when the non-standard scalars are
light, the new vector boson is too broad to be recognized as a resonance and is
not detectable except when the mass of the scalars is close to (but smaller
than) a half of the resonance mass and the scale of the dark sector is high. In
all the positive cases, less than a tenth of the maximum integrated luminosity
is needed to reach the discovery level. Finally, we also comment about the
mono-$Z$ production.",1808.06209v2
2018-08-28,Pareto optimization of resonances and minimum-time control,"The aim of the paper is to reduce one spectral optimization problem, which
involves the minimization of the decay rate $|\mathrm{Im} \, k |$ of a
resonance $k$, to a collection of optimal control problems on the Riemann
sphere $\widehat{\mathbb{C}}$. This reduction allows us to apply methods of
extremal synthesis to the structural optimization of layered optical cavities.
We start from a dual problem of minimization of the resonator length and give
several reformulations of this problem that involve Pareto optimization of the
modulus $|k|$ of a resonance, a minimum-time control problem on
$\widehat{\mathbb{C}}$, and associated Hamilton-Jacobi-Bellman equations.
Various types of controllability properties are studied in connection with the
existence of optimizers and with the relationship between the Pareto optimal
frontiers of minimal decay and minimal modulus. We give explicit examples of
optimal resonances and describe qualitatively properties of the Pareto
frontiers near them. A special representation of bang-bang controlled
trajectories is combined with the analysis of extremals to obtain various
bounds on optimal widths of layers. We propose a new method of computation of
optimal symmetric resonators based on minimum-time control and compute with
high accuracy several Pareto optimal frontiers and high-Q resonators.",1808.09186v2
2018-11-29,Electric-Dipole Spin Resonances,"Resonance phenomena in solids generally fall into two distinct classes,
electric and magnetic, driven, respectively, by the $E$ and $H$ components of
the electromagnetic wave incident on the solid. The canonical examples of the
two types of resonances are the electron cyclotron resonance (CR) and the
electron paramagnetic resonance (EPR), originating from the electron orbital
and spin degrees of freedom, respectively. The behavior becomes considerably
more interesting (and more complicated) in the presence of the spin-orbital
interaction. In this case, a more general type of resonance may occur, which is
driven by the electric excitation mechanism and involves the spin degrees of
freedom. Such electric-dipole spin resonance (EDSR) may occur at the spin
excitation frequency or at a combination of the orbital and spin frequencies,
spanning a wide bandwidth. The EDSR phenomenon, first predicted by Rashba
(1960), has been probed experimentally in 3D solids with different crystal
symmetries, as well as in low-dimensional systems (heterojunctions, inversion
layers, dislocations and impurity states). Due to its electric dipole origin,
the EDSR features a relatively high intensity, which may exceed by orders of
magnitude the EPR intensity. This review summarizes the work on EDSR prior to
1991, laying out the theoretical framework and discussing different
experimental systems in which the EDSR-related physics can be realized and
explored.",1812.01721v1
2018-12-19,Nonclassicality in off-resonant Raman process,"Raman process is used for generation of nonclassical states and subsequent
applications due to its simplicity. In view of the experimental feasibility of
the off-resonant Raman process at single photon level useful in long distance
quantum communication and quantum memory, we perform here a detailed study of
possibility of generation of nonclassical states under off-resonance
conditions. Specifically, we have studied nonclassicality in the off-resonant
Raman process with the help of a characteristic function written using more
general solution than the conventional short-time solution under complete
quantum treatment and established the significance of frequency detuning
parameter in generation of nonclassical states. The obtained characteristic
function remains Gaussian and reveals that larger values of frequency detuning
parameters are favorable to induce nonclassicality in some cases. The single-
and two-mode squeezing and antibunching as well as intermodal entanglement are
reported in terms of experimentally accessible quantum noise fluctuations
considering either phonon mode coherent or chaotic. Subsequently, the joint
photon number and integrated intensity distributions are studied to analyze the
performance of pair generation in Stokes-phonon and pump-phonon modes. The
present study discusses the role of resonance conditions in generation of
nonclassical states and establishes that experimentally controllable detuning
parameter can be used to probe and enhance the generated nonclassicality.",1812.08264v1
2019-01-10,High-cooperativity coupling of a rare-earth spin ensemble to a superconducting resonator using yttrium orthosilicate as a substrate,"Yttrium orthosilicate (Y$_2$SiO$_5$, or YSO) has proved to be a convenient
host for rare-earth ions used in demonstrations of microwave quantum memories
and optical memories with microwave interfaces, and shows promise for coherent
microwave--optical conversion owing to its favourable optical and spin
properties. The strong coupling required by such microwave applications could
be achieved using superconducting resonators patterned directly on
Y$_2$SiO$_5$, and hence we investigate here the use of Y$_2$SiO$_5$ as an
alternative to sapphire or silicon substrates for superconducting hybrid device
fabrication. A NbN resonator with frequency 6.008 GHz and low power quality
factor $Q \approx 400000$ was fabricated on a Y$_2$SiO$_5$ substrate doped with
isotopically enriched Nd$^{145}$. Measurements of dielectric loss yield a
loss-tangent $\tan\delta = 4 \times 10^{-6}$, comparable to sapphire. Electron
spin resonance (ESR) measurements performed using the resonator show the
characteristic angular dependence expected from the anisotropic Nd$^{145}$
spin, and the coupling strength between resonator and electron spins is in the
high cooperativity regime ($C = 30$). These results demonstrate Y$_2$SiO$_5$ as
an excellent substrate for low-loss, high-Q microwave resonators, especially in
applications for coupling to optically-accessible rare earth spins.",1901.03262v2
2019-01-13,"Roles of $^7$Be$(n,p)^7$Li resonances in big bang nucleosynthesis with time-dependent quark mass and Li reduction by a heavy quark mass","Big bang nucleosynthesis (BBN) has been used as a probe of beyond-standard
physics in the early Universe, which includes a time-dependent quark mass m_q.
We investigate effects of a quark mass variation delta m_q on the cross
sections of the 7Be(n, p)7Li reaction and primordial light element abundances
taking into account roles of 8Be resonances in the reaction during BBN. This
resonant reaction has not been investigated although behaviors of low-lying
resonances are not trivial. It is found that a resonance at the resonance
energy E_r=0.33 MeV enhances the reaction rate and lowers the 7Li abundance
significantly when the quark mass variation is negative. Based upon up-to-date
observational limits on primordial abundances of D, 4He and Li, the quark mass
variation in the BBN epoch are derived. In a model in which the resonance
energies of the reactions 3He(d, p)4He and 3H(d, n)4He are insensitive to the
quark mass, we find that the Li abundance can be consistent with observations
for delta m_q/m_q = (4--8) times 10^{-3}.",1901.03943v1
2019-01-13,Stochastic resonance and bifurcation of order parameter in a coupled system of underdamped Duffing oscillators,"The long-term mean-field dynamics of coupled underdamped Duffing oscillators
driven by an external periodic signal with Gaussian noise is investigated. A
Boltzmann-type H-theorem is proved for the associated nonlinear Fokker-Planck
equation to ensure that the system can always be relaxed to one of the
stationary states as time is long enough. Based on a general framework of the
linear response theory, the linear dynamical susceptibility of the system order
parameter is explicitly deduced. With the spectral amplification factor as a
quantifying index, calculation by the method of moments discloses that both
mono-peak and double-peak resonance might appear, and that noise can greatly
signify the peak of the resonance curve of the coupled underdamped system as
compared with a single-element bistable system. Then, with the input signals
taken from laboratory experiments, further observations show that the
mean-field coupled stochastic resonance system can amplify the periodic input
signal. Also, it reveals that for some driving frequencies, the optimal
stochastic resonance parameter and the critical bifurcation parameter have a
close relationship. Moreover, it is found that the damping coefficient can also
give rise to nontrivial non-monotonic behaviors of the resonance curve, and the
resultant resonant peak attains its maximal height if the noise intensity or
the coupling strength takes the critical value. The new findings reveal the
role of the order parameter in a coupled system of chaotic oscillators.",1901.03955v2
2019-02-01,On the 9:7 Mean Motion Resonance Capture in a System of Two Equal-mass Super-Earths,"We study the formation of the 9:7 mean motion resonance in a system of two
low-mass planets ($m_{1}=m_{2}=3M_{\oplus}$) embedded in a gaseous
protoplanetary disk employing a full 2D hydrodynamic treatment of the
disk-planet interactions. Our aim is to determine the disk properties that
favor a capture of two equal-mass super-Earths into this second-order
resonance. For this purpose, we have performed a series of numerical
hydrodynamic simulations of the system of two super-Earths migrating in disks
with a variety of different initial parameters and found conditions for the
permanent or temporary locking in the 9:7 resonance. We observe that capture
occurs during the convergent migration of planets if their resonance angle at
the moment of arrival at the resonance assumes values in a certain range
(inside a window of capture). The width of such a window depends on the
relative migration and circularization rates that are determined by the disk
parameters. The window is wide if the relative migration rate is slow, and it
becomes narrower as the relative migration rate increases. The window will be
closed if the migration rate is sufficiently high, and the capture will not
take place. We illustrate also how the 9:7 resonance window of capture is
affected by the initial eccentricities and the initial orbits of the planets.",1902.00437v1
2019-02-08,A critical point in the distribution of lepton energies from the decay of a spin-1 resonance,"We consider a spin-$1$ resonance produced with an arbitrary spectrum of
velocities and decaying into a pair of massless leptons, and we study the
probability density function of the energy of the leptons in the laboratory
frame. A special case is represented by the production of $W$ bosons in
proton-proton collisions, for which the energy of the charged lepton from the
decaying $W$ can be measured with sufficient accuracy for a high-precision
measurement of $M_W$. We find that half of the resonance mass is a special
value of the lepton energy, since the probability density function at this
point is in general not analytic for a narrow-width resonance. In particular,
the higher-order derivatives of the density function are likely to develop
singularities, such as cusps or poles. A finite width of the resonance restores
the regularity, for example by smearing cusps and poles into local stationary
points. The quest for such points offers a handle to estimate the resonance
mass with much reduced dependence on the underlying production and decay
dynamics of the resonance.",1902.03028v3
2019-03-15,Phase-Locked Loop based Resonant Sensors: A Rigorous Theory and General Analysis Framework for Deciphering Fundamental Sensitivity Limitations due to Noise,"Nanomechanical resonators are used in building ultra-sensitive mass and force
sensors. In a widely used resonator based sensing paradigm, each modal
resonance frequency is tracked with a phase-locked loop (PLL) based system.
There is great interest in deciphering the fundamental sensitivity limitations
due to inherent noise and fluctuations in PLL based resonant sensors to improve
their performance. In this paper, we present a precise, first-principles based
theory for the analysis of PLL based resonator tracking systems. Based on this
theory, we develop a general, rigorously-derived noise analysis framework for
PLL based sensors. We apply this framework to a setting where the sensor
performance is mainly limited by the thermomechanical noise of the
nanomechanical resonator. The results that are deduced through our analysis
framework are in complete agreement with the ones we obtain from extensive,
carefully run stochastic simulations of a PLL based sensor system. We compare
the conclusions we derive with the recent results in the literature. Our theory
and analysis framework can be used in assessing PLL based sensor performance
with other sources of noise, e.g., from the electronic components, actuation
and sensing mechanisms, and due to the signal generator, as well as for a
variety of PLL based sensor configurations such as multi-mode and nonlinear
sensing.",1903.06497v1
2019-04-06,A simple metamaterial absorber associated with Fano-like resonance,"A simple metamaterial absorber suitable for fabrication over large areas
associated with a Fano like resonance is proposed. The proposed designed of the
metamaterial absorber consists of photoresist disk arrays on a silicon
substrate followed by the deposition of a tri layer of Au, ZnS and Au on the
top of the structure. Due to the tri layer, there is a formation of a cavity
between the substrate and gold layer on the top of photoresist disk and a
waveguide in the ZnS layer in between the gold layers on the substrate and the
ZnS layer itself. The Fano like resonance arises due to the interference of the
cavity mode and the guided-mode resonance as well as the Woods anomaly. The
cavity mode resonance works as continuum mode whereas the guided mode resonance
and Woods anomaly work as discrete modes. The spectral position of the
resonance can be tuned by just controlling the thickness of the tri layer
instead of the structural size and shape modification of the micro and
nano-structures as usually done in conventional metamaterial absorbers. This
design can be easily scaled for fabrication over large areas as it separates
the structuring and deposition processes and makes them sequential thereby
avoiding expensive and complex lift off or etching processes which are usually
required for conventional metamaterial processing.",1904.03381v1
2019-04-08,Point-dipole approximation for small systems of strongly coupled radiating nanorods,"Systems of closely-spaced resonators can be strongly coupled by interactions
mediated by scattered electromagnetic fields. In large systems the resulting
response has been shown to be more sensitive to these collective interactions
than to the detailed structure of individual resonators. Attempts to describe
such systems have resulted in point-dipole approximations to resonators that
are computationally efficient for large resonator ensembles. Here we provide a
detailed study for the validity of point dipole approximations in small systems
of strongly coupled plasmonic nanorods, including the cases of both
super-radiant and subradiant excitations, where the characteristics of the
excitation depends on the spatial separation between the nanorods. We show that
over an appreciable range of rod lengths centered on $210~\text{nm}$, when the
relative separation $kl$ in terms of the resonance wave number of light $k$
satisfies $kl \gtrsim \pi/2$, the point electric dipole model becomes accurate.
However, when the resonators are closer, the finite-size and geometry of the
resonators modifies the excitation modes, in particular the cooperative mode
line shifts of the point dipole approximation begin to rapidly diverge at small
separations. We also construct simplified effective models by describing a pair
of nanorods as a single effective metamolecule.",1904.03935v1
2019-04-11,Optimal Electromagnetic Searches for Axion and Hidden-Photon Dark Matter,"Direct-detection searches for axions and hidden photons are playing an
increasingly prominent role in the search for dark matter. In this work, we
derive the properties of optimal electromagnetic searches for these candidates,
subject to the Standard Quantum Limit (SQL) on amplification. We show that a
single-pole resonant search may possess substantial sensitivity outside of the
resonator bandwidth and that optimizing this sensitivity may increase scan
rates by up to five orders of magnitude at low frequencies. Additional
enhancements can be obtained with resonator quality factors exceeding one
million, which corresponds to the linewidth of the dark matter signal. We
present the resonator optimization in the broader context of determining the
optimal receiver architecture (resonant or otherwise). We discuss prior
probabilities on the dark matter signal and their role in the search
optimization. We determine frequency-integrated sensitivity to be the figure of
merit in a wideband search and demonstrate that it is limited by the Bode-Fano
criterion. The optimized single-pole resonator is approximately 75% of the
Bode-Fano limit, establishing it as a fundamentally near-ideal, single-moded
dark matter detection scheme. Our analysis shows, in contrast to previous work,
that the scanned single-pole resonant search is superior to a reactive
broadband search. Our results motivate the broad application of quantum
measurement techniques evading the SQL in future axion and hidden-photon dark
matter searches.",1904.05806v2
2019-08-26,Individual nanoantennas empowered by bound states in the continuum for nonlinear photonics,"Bound states in the continuum (BICs) represent localized modes with energies
embedded in the continuous spectrum of radiating waves. BICs were discovered
initially as a mathematical curiosity in quantum mechanics, and more recently
were employed in photonics. Pure mathematical bound states have
infinitely-large quality factors (Q factors) and zero resonant linewidth. In
optics, BICs are physically limited by a finite size, material absorption,
structural disorder, and surface scattering, and they manifest themselves as
the resonant states with large Q factors, also known as supercavity modes or
quasi-BICs. Optical BIC resonances have been demonstrated only in extended 2D
and 1D systems and have been employed for distinct applications including
lasing and sensing. Optical quasi-BIC modes in individual nanoresonators have
been discovered recently but they were never observed in experiment. Here, we
demonstrate experimentally an isolated subwavelength nanoresonator hosting a
quasi-BIC resonance. We fabricate the resonator from AlGaAs material on an
engineered substrate, and couple to the quasi-BIC mode using structured light.
We employ the resonator as a nonlinear nanoantenna and demonstrate record-high
efficiency of second-harmonic generation. Our study brings a novel platform to
resonant subwavelength photonics.",1908.09790v1
2019-08-30,Kinetic freeze-out temperature from yields of short-lived resonances,"A method to determine the kinetic freeze-out temperature in heavy-ion
collisions from measured yields of short-lived resonances is presented. The
resonance production is treated in the framework of thermal model with an
evolution between chemical and kinetic freeze-outs. The yields of many
short-lived resonances are suppressed at $T = T_{\rm kin} < T_{\rm ch}$. We
determine the values of $T_{\rm kin}$ and $T_{\rm ch}$ for various centralities
in Pb--Pb collisions at $\sqrt{s_{_{NN}}} = 2.76$ TeV by fitting the abundances
of both the stable hadrons and the short-lived resonances such as $\rho^0$ and
$ \text{K}^{*0}$, that were measured by the ALICE collaboration. This allows to
extract the kinetic freeze-out temperature from the measured hadron and
resonance yields alone, independent of assumptions about the flow velocity
profile and the freeze-out hypersurface. The extracted $T_{\rm ch}$ values
exhibit a moderate multiplicity dependence whereas $T_{\rm kin}$ drops, from
$T_{\rm kin} \simeq T_{\rm ch} \simeq 155$ MeV in peripheral collisions to
$T_{\rm kin} \simeq 110$ MeV in 0-20% central collisions. Predictions for other
short-lived resonances are presented. A potential (non-)observation of a
suppressed $f_0(980)$ meson yield will allow to constrain the lifetime of that
meson.",1908.11730v3
2019-10-31,Extreme Sub-Wavelength Light Confinement in Plasmonic Film-Coupled Nanostar Resonators,"Confining light in extreme subwavelength scales is a tantalizing task. In
this work, we report a study of individual plasmonic film-coupled nanostar
resonators where plasmonic optical modes are trapped in ultrasmall volumes.
Individual gold nanostars, separated from a flat gold film by a thin dielectric
spacer layer, exhibit a strong light confinement within the sub-10 nm volume of
the nanostar's tips and the film. Through dark field scattering measurements of
many individual nanostars, a statistical observation of the scattered spectra
is obtained and compared with extensive simulation data to reveal the origins
of the resonant peaks. We observe that an individual nanostar on a flat gold
film can result in a resonant spectrum with single, double or multiple peaks.
Further, these resonant peaks are strongly polarized under white light
illumination. Our simulation data revealed that the resonant spectrum of an
individual film-coupled nanostar resonator is related to the symmetry of the
nanostar, as well as the orientation of the nanostar relative to its placement
on the gold substrate. Our results demonstrate a simple method to create an
ultrasmall mode volume plasmonic platform which could be useful for
applications in sensing or enhanced light-matter interactions.",1911.00123v2
2019-11-21,Doubling the near-infrared photocurrent in a solar cell via omni-resonant coherent perfect absorption,"Minimizing the material usage in thin-film solar cells can reduce
manufacturing costs and enable mechanically flexible implementations, but
concomitantly diminishes optical absorption. Coherent optical effects can help
alleviate this inevitable drawback at discrete frequencies. For example,
coherent perfect absorption guarantees that light is fully absorbed in a thin
layer regardless of material or thickness but only on resonance. Here we show
that omni resonance delivers such coherent enhancement over a broad bandwidth
by structuring the optical field to nullify the angular dispersion intrinsic to
resonant structures. After embedding an amorphous-silicon thin film
photovoltaic cell in a planar cavity, pre conditioning the incident light using
an alignment free optical arrangement severs the link between the resonant
bandwidth and the cavity photon lifetime, thereby rendering the cavity omni
resonant. Coherently enhanced near infrared absorption doubles the photocurrent
over the targeted spectral range 660 to 740 nm where every wavelength
resonates. These results may pave the way to transparent solar cells that
optimally harvest near infrared light.",1911.09276v2
2019-12-03,Asymptotics of random resonances generated by a point process of delta-interactions,"We introduce and study the following model for random resonances: we take a
collection of point interactions $\Upsilon_j$ generated by a simple finite
point process in the 3-D space and consider the resonances of associated random
Schr\""odinger Hamiltonians $H_\Upsilon = -\Delta + ``\sum \mathfrak{m}(\alpha)
\delta (x - \Upsilon_j)``$. These resonances are zeroes of a random exponential
polynomial, and so form a point process $\Sigma (H_\Upsilon)$ in the complex
plane $\mathbb{C}$. We show that the counting function for the set of random
resonances $\Sigma (H_\Upsilon)$ in $\mathbb{C}$-discs with growing radii
possesses Weyl-type asymptotics almost surely for a uniform binomial process
$\Upsilon$, and obtain an explicit formula for the limiting distribution as $m
\to \infty$ of the leading parameter of the asymptotic chain of `most narrow'
resonances generated by a sequence of uniform binomial processes $\Upsilon^m$
with $m$ points. We also pose a general question about the limiting behavior of
the point process formed by leading parameters of asymptotic sequences of
resonances. Our study leads to questions about metric characteristics for the
combinatorial geometry of $m$ samples of a random point in the 3-D space and
related statistics of extreme values.",1912.01680v1
2020-03-23,Mathematical analysis of electromagnetic scattering by dielectric nanoparticles with high refractive indices,"In this work, we are concerned with the mathematical modeling of the
electromagnetic (EM) scattering by arbitrarily shaped non-magnetic
nanoparticles with high refractive indices. When illuminated by visible light,
such particles can exhibit a very strong isotropic magnetic response, resulting
from the coupling of the incident wave with the circular displacement currents
of the EM fields. The main aim of this work is to mathematically illustrate
this phenomenon. We shall first introduce the EM scattering resolvent and the
concept of dielectric subwavelength resonances. Then we derive the a priori
estimates for the subwavelength resonances and the associated resonant modes.
We also show the existence of resonances and obtain their asymptotic expansions
in terms of the small particle size and the high contrast parameter. After
that, we investigate the enhancement of the scattering amplitude and the cross
sections when the resonances occur. In doing so, we develop a novel multipole
radiation framework that directly separates the electric and magnetic multipole
moments and allows us to clearly see their orders of magnitude and blow--up
rates. We prove that at the dielectric subwavelength resonant frequencies, the
nanoparticles with high refractive indices behave like the sum of the electric
dipole and the resonant magnetic dipole. Some explicit calculations and
numerical experiments are also provided to validate our general results and
formulas.",2003.10223v2
2020-05-01,Analytical Model for the Tidal Evolution of the Evection Resonance and the Timing of Resonance Escape,"A high-angular momentum giant impact with the Earth can produce a Moon with a
silicate isotopic composition nearly identical to that of Earth's mantle,
consistent with observations of terrestrial and lunar rocks. However, such an
event requires subsequent angular momentum removal for consistency with the
current Earth-Moon system. The early Moon may have been captured into the
evection resonance, occurring when the lunar perigee precession period equals
one year. It has been proposed that after a high-angular momentum giant impact,
evection removed the angular momentum excess from the Earth-Moon pair and
transferred it to Earth's orbit about the Sun. However, prior N-body
integrations suggest this result depends on the tidal model and chosen tidal
parameters. Here we examine the Moon's encounter with evection using a
complementary analytic description and the Mignard tidal model. While the Moon
is in resonance the lunar longitude of perigee librates, and if tidal evolution
excites the libration amplitude sufficiently, escape from resonance occurs. The
angular momentum drain produced by formal evection depends on how long the
resonance is maintained. We estimate that resonant escape occurs early, leading
to only a small reduction (~few to 10%) in the Earth-Moon system angular
momentum. Moon formation from a high-angular momentum impact would then require
other angular momentum removal mechanisms beyond standard libration in
evection, as have been suggested previously.",2005.00587v1
2020-05-18,Scalable near-infrared graphene plasmonic resonators exhibiting strong non-local and electron quantization effects,"Graphene plasmonic resonators have been broadly studied in the terahertz and
mid-infrared ranges because of their electrical tunability and large
confinement factors which can enable dramatic enhancement of light-matter
coupling. In this work, we demonstrate that the characteristic scaling laws of
graphene plasmons change for smaller (< 40 nm) plasmonic wavelengths, expanding
the operational frequencies of graphene plasmonic resonators into the
near-infrared (NIR) and modifying their optical confinement properties. We
utilize a novel bottom-up block copolymer lithography method that substantially
improves upon top-down methods to create resonators as narrow as 12 nm over
centimeter-scale areas. Measurements of these structures reveal that their
plasmonic resonances are strongly influenced by non-local and quantum effects,
which push their resonant frequency into the NIR (2.2 um), almost double the
frequency of previous experimental works. The confinement factors of these
resonators, meanwhile, reach 137 +/- 25, amongst the largest reported in
literature for an optical cavity. While our findings indicate that the
enhancement of some 'forbidden' transitions are an order of magnitude weaker
than predicted, the combined NIR response and large confinement of these
structures make them an attractive platform to explore ultra-strongly enhanced
spontaneous emission.",2005.09053v1
2020-05-29,Electron spin resonance and ferromagnetic resonance spectroscopy in the high-field phase of the van der Waals magnet CrCl$_3$,"We report a comprehensive high-field/high-frequency electron spin resonance
(ESR) study on single crystals of the van der Waals magnet CrCl$_3$. This
material, although being known for quite a while, has received recent
significant attention in a context of the use of van der Waals magnets in novel
spintronic devices. Temperature-dependent measurements of the resonance fields
were performed between 4 and 175 K and with the external magnetic field applied
parallel and perpendicular to the honeycomb planes of the crystal structure.
These investigations reveal that the resonance line shifts from the
paramagnetic resonance position already at temperatures well above the
transition into a magnetically ordered state. Thereby the existence of
ferromagnetic short-range correlations above the transition is established and
the intrinsically two-dimensional nature of the magnetism in the title compound
is proven. To study details of the magnetic anisotropies in the field-induced
effectively ferromagnetic state at low temperatures, frequency-dependent
ferromagnetic resonance (FMR) measurements were conducted at 4 K. The observed
anisotropy between the two magnetic-field orientations is analyzed by means of
numerical simulations based on a phenomenological theory of FMR. These
simulations are in excellent agreement with measured data if the shape
anisotropy of the studied crystal is taken into account, while the
magnetocrystalline anisotropy is found to be negligible in CrCl$_3$. The
absence of a significant intrinsic anisotropy thus renders this material as a
practically ideal isotropic Heisenberg magnet.",2005.14559v1
2020-05-25,Observation of supercavity modes in subwavelength dielectric resonators,"Electromagnetic response of dielectric resonators with high refractive index
is governed by optically induced electric and magnetic Mie resonances
facilitating confinement of light with the amplitude enhancement. However,
strong subwavelength trapping of light was associated traditionally only with
plasmonic or epsilon-near-zero structures which however suffer from losses.
Recently, an alternative localization mechanism was proposed to trap light in
individual subwavelength optical resonators with a high quality factor in the
regime of a supercavity mode. Here, we present the experimental observation of
the supercavity modes in subwavelength ceramic resonators in the radiofrequency
range. We demonstrate experimentally that the regime of supercavity mode can be
achieved via precise tuning of the resonator's dimensions resulting in a huge
growth of the quality factor reaching the experimental values up to 1.25x10^4,
being limited only by material losses in dielectrics. We reveal that the
supercavity modes can be excited efficiently by both near- and far-fields by
means of dipole sources and plane waves, respectively. In both the cases, the
supercavity mode manifests itself clearly via characteristic peculiarities of
the Fano resonance and radiation patterns. Our work paves the way for future
compact practical devices in photonics and radiophysics.",2006.02262v2
2020-06-08,Applicability of the Rytov full effective-medium formalism to the physical description and design of resonant metasurfaces,"Periodic photonic lattices constitute a fundamental pillar of physics
supporting a plethora of scientific concepts and applications. The advent of
metamaterials and metastructures is grounded in deep understanding of their
properties. Based on the original 1956 formulation by Rytov, it is well known
that a photonic lattice with deep subwavelength periodicity can be approximated
with a homogeneous space having an effective refractive index. Whereas the
attendant effective-medium theory (EMT) commonly used in the literature is
based on the zeroth root, the closed-form transcendental equations possess an
infinite number of roots. Thus far, these higher-order solutions have been
totally ignored; even Rytov himself discarded them and proceeded to approximate
solutions for the deep-subwavelength regime. In spite of the fact that the
Rytov EMT models an infinite half-space lattice, it is highly relevant to
modeling practical thin-film periodic structures with finite thickness as we
show. Therefore, here, we establish a theoretical framework to systematically
describe subwavelength resonance behavior and to predict the optical response
of resonant photonic lattices using the full Rytov solutions. Expeditious
results are obtained with direct, new physical insights available for resonant
lattice properties. We show that the full Rytov formulation implicitly contains
refractive-index solutions pertaining directly to evanescent waves that drive
the laterally-propagating Bloch modes foundational to resonant lattice
properties. In fact, the resonant reradiated Bloch modes experience
wavelength-dependent refractive indices that are solutions of the Rytov
expressions. This insight is useful in modeling guided-mode resonant devices
including wideband reflectors, bandpass filters, and polarizers.",2006.04852v1
2020-06-29,Many-body Resonance in a Correlated Topological Kagome Antiferromagnet,"We use scanning tunneling microscopy/spectroscopy (STM/S) to elucidate the
atomically resolved electronic structure in strongly correlated topological
kagome magnet Mn$_3$Sn. In stark contrast to its broad single-particle
electronic structure, we observe a pronounced resonance with a Fano line shape
at the Fermi level resembling the many-body Kondo resonance. We find that this
resonance does not arise from the step edges or atomic impurities, but the
intrinsic kagome lattice. Moreover, the resonance is robust against the
perturbation of a vector magnetic field, but broadens substantially with
increasing temperature, signaling strongly interacting physics. We show that
this resonance can be understood as the result of geometrical frustration and
strong correlation based on the kagome lattice Hubbard model. Our results point
to the emergent many-body resonance behavior in a topological kagome magnet.",2006.15770v1
2020-08-21,Magnons Parametric Pumping in Bulk Acoustic Waves Resonator,"We report on the experimental observation of excitation and detection of
parametric spin waves and spin currents in the bulk acoustic wave resonator.
The hybrid resonator consists of ZnO piezoelectric film, yttrium iron garnet
(YIG) films on gallium gadolinium garnet substrate, and a heavy metal Pt layer.
Shear bulk acoustic waves are electrically excited in the ZnO layer due to
piezoeffect at the resonant frequencies of the resonator. The magnetoelastic
interaction in the YIG film emerges magnons (spin waves) excitation by acoustic
waves either on resonator's eigenfrequencies or the half-value frequencies at
supercritical power. We investigate acoustic pumping of magnons at the
half-value frequencies and acoustic spin pumping from parametric magnons, using
the inverse spin Hall effect in the Pt layer. The constant electric voltage in
the Pt layer, depending on the frequency, the magnetic field, and the pump
power, was systematically studied. We explain the low threshold obtained (~0.4
mW) by the high efficiency of electric power transmission into the acoustic
wave in the resonator.",2008.09520v1
2020-09-01,"Microscopic investigation of the $^8$Li($n, γ$)$^9$Li reaction","The $^8$Li($n,\gamma$)$^9$Li reaction plays an important role in several
astrophysics scenarios. It cannot be measured directly and indirect experiments
have so far provided only cross section limits. Theoretical predictions differ
by an order of magnitude. In this work we study the properties of $^9$Li bound
states and low-lying resonances and calculate the $^8$Li($n,\gamma$)$^9$Li
cross section within the no-core shell model with continuum (NCSMC) with chiral
nucleon-nucleon and three-nucleon interactions as the only input. The NCSMC is
an ab initio method applicable to light nuclei that provides a unified
description of bound and scattering states well suited to calculate low-energy
nuclear scattering and reactions. Our calculations reproduce the experimentally
known bound states as well as the lowest $5/2^-$ resonance of $^9$Li. We
predict a $3/2^-$ spin-parity assignment for the resonance observed at 5.38
MeV. In addition to the a very narrow $7/2^-$ resonance corresponding
presumably to the experimental 6.43 MeV state, we find several other broad
low-lying resonances. Our calculated $^8$Li($n,\gamma$)$^9$Li cross section is
within the limits derived from the 1998 National Superconducting Cyclotron
Laboratory Coulomb-dissociation experiment [Phys. Rev. C {\bf 57}, 959 (1998)].
However, it is higher than cross sections obtained in recent phenomenological
studies. It is dominated by a direct E1 capture to the ground state with a
resonant contribution at $\sim0.2$ MeV due to E2/M1 radiation enhanced by the
$5/2^-$ resonance.",2009.00658v2
2020-09-02,Resonant Vibrational-Electronic Coupling between Photosynthetic Excitons is Inadequately Described by Reduced Basis Sets,"Vibrational-electronic (vibronic) resonance and its role in energy and charge
transfer has been experimentally and theoretically investigated in several
photosynthetic proteins. Using a dimer modeled on a typical photosynthetic
protein, we contrast the description of such excitons provided by an exact
basis set description, as opposed to a basis set with reduced vibrational
dimensionality. Using a reduced analytical description of the full Hamiltonian,
we show that in the presence of vibrational excitation both on electronically
excited as well as unexcited sites, constructive interference between such
basis states causes vibronic coupling between excitons to become progressively
stronger with increasing quanta of vibrational excitation. This effect leads to
three distinguishing features of excitons coupled through a vibronic resonance
which are not captured in basis sets with reduced vibrational dimensionality -
1. the vibronic resonance criterion itself, 2. vibronically assisted perfect
delocalization between sites even though purely electronic mixing between the
sites is imperfect due to energetic disorder, 3. the nuclear distortion
accompanying vibronic excitons becoming increasingly larger for resonant
vibronic coupling involving higher vibrational quanta. In terms of
spectroscopically observable limitations of reduced basis set descriptions of
vibronic resonance, several differences are seen in absorption and emission
spectra, but may be obscured on account of overwhelming line broadening.
However, we show that several features such as vibronic exciton delocalization
and vibrational distortions associated with electronic excitations, which
ultimately dictate the excited state wavepacket motions and relaxation
processes, are fundamentally not described under reduced basis set descriptions
of vibronic resonance.",2009.00995v1
2020-09-16,Unconventional magnon excitation by off-resonant microwaves,"It is widely recognized that a physical system can only respond to a periodic
driving significantly when the driving frequency matches the normal mode
frequency of the system, which leads to resonance. Off-resonant phenomena are
rarely considered because of the difficulty to realize strong coupling between
physical systems and off-resonant waves. Here we examine the response of a
magnetic system to squeezed light and surprisingly find that the magnons are
maximally excited when the effective driving frequency is several orders of
magnitude larger than the resonant frequency. The generated magnons are
squeezed which brings the advantage of tunable squeezing through an external
magnetic field. Furthermore, we demonstrate that such off-resonant
quasi-particle excitation is universal in all the hybrid systems in which the
coherent and parametric interaction of bosons exists and that it is purely a
quantum effect, which is rooted in the quantum fluctuations of particles in the
squeezed vacuum. Our findings may provide an unconventional route to study
off-resonant phenomena and may further benefit the use of hybrid matter-light
systems in continuous variable quantum information.",2009.07948v2
2020-10-15,Scattering resonances in unbounded transmission problems with sign-changing coefficient,"It is well-known that classical optical cavities can exhibit localized
phenomena associated to scattering resonances, leading to numerical
instabilities in approximating the solution. This result can be established via
the ``quasimodes to resonances'' argument from the black-box scattering
framework. Those localized phenomena concentrate at the inner boundary of the
cavity and are called whispering gallery modes. In this paper we investigate
scattering resonances for unbounded transmission problems with sign-changing
coefficient (corresponding to optical cavities with negative optical
properties, for example made of metamaterials). Due to the change of sign of
optical properties, previous results cannot be applied directly, and interface
phenomena at the metamaterial-dielectric interface (such as the so-called
surface plasmons) emerge. We establish the existence of scattering resonances
for arbitrary two-dimensional smooth metamaterial cavities. The proof relies on
an asymptotic characterization of the resonances, and showing that problems
with sign-changing coefficient naturally fit the black box scattering
framework. Our asymptotic analysis reveals that, depending on the
metamaterial's properties, scattering resonances situated closed to the real
axis are associated to surface plasmons. Examples for several metamaterial
cavities are provided.",2010.07583v3
2020-11-17,Dispersive measurement of a semiconductor double quantum dot via 3D integration of a high-impedance TiN resonator,"Spins in semiconductor quantum dots are a candidate for cryogenic quantum
processors due to their exceptionally long coherence times. One major challenge
to scaling quantum dot spin qubits is the dense wiring requirements, making it
difficult to envision fabricating large arrays of nearest-neighbor-coupled
qubits necessary for error correction. We describe a method to solve this
problem by spacing the qubits out using high-impedance superconducting
resonators with a 2D grid unit cell area of $0.16~\text{mm}^2$ using 3D
integration. To prove the viability of this approach, we demonstrate 3D
integration of a high-impedance TiN resonator coupled to a double quantum dot
in a Si/SiGe heterostructure. Using the resonator as a dispersive gate sensor,
we tune the device down to the single electron regime with an SNR = 5.36
limited by the resonator-dot capacitance. Characterization of the dot and
resonator systems shows such integration can be done while maintaining low
charge noise metrics for the quantum dots and with improved loaded quality
factors for the superconducting resonator ($Q_L = 2.14 \times 10^4$), allowing
for high-sensitivity charge detection and the potential for high fidelity
2-qubit gates. This work paves the way for 2D quantum dot qubit arrays with
cavity mediated interactions.",2011.08759v1
2021-02-16,Tree-ring structure of Galactic bar resonance,"Galaxy models have long predicted that galactic bars slow down by losing
angular momentum to their postulated dark haloes. When the bar slows down,
resonance sweeps radially outwards through the galactic disc while growing in
volume, thereby sequentially capturing new stars at its surface/separatrix.
Since trapped stars conserve their action of libration, which measures the
relative distance to the resonance centre, the order of capturing is preserved:
the surface of the resonance is dominated by stars captured recently at large
radius, while the core of the resonance is occupied by stars trapped early at
small radius. The slow-down of the bar thus results in a rising mean
metallicity of trapped stars from the surface towards the centre of the
resonance as the Galaxy's metallicity declines towards large radii. This
argument, when applied to Solar neighbourhood stars, allows a novel precision
measurement of the bar's current pattern speed $\Omega_p = 35.5 \pm 0.8$
km/s/kpc, placing the corotation radius at $R_{CR} = 6.6 \pm 0.2$ kpc. With
this pattern speed, the corotation resonance precisely fits the Hercules stream
in agreement with kinematics. Beyond corroborating the slow bar theory, this
measurement manifests the deceleration of the bar of more than 24% since its
formation and thus the angular momentum transfer to the dark halo by dynamical
friction. The measurement therefore supports the existence of a standard
dark-matter halo rather than alternative models of gravity.",2102.08388v2
2021-02-27,Hybrid model of proton structure functions,"We develop a ""hybrid"" model of the proton inelastic structure functions
applicable in a wide region of invariant mass of produced states $W$ and
invariant momentum transfer $Q$ including deep inelastic scattering (DIS),
nucleon resonance production as well as the region close to inelastic
threshold. DIS is described in terms of the parton distributions together with
higher-twist corrections from an available global QCD fit. The resonant part is
addressed in terms of the Breit-Wiegner contributions from five states
including the $\Delta(1232)$ resonance, the $N(1440)$ Roper resonance, and
three effective resonances describing the second and third resonance regions.
The couplings of the nucleon resonances to photon are described in terms of
helicity amplitudes. The nonresonant background is addressed in terms of DIS
structure functions smoothly extrapolated to low-$W$ and low-$Q$ values with
the proper behavior at the real photon limit $Q^2=0$ as well as near the
inelastic threshold. We independently treat the transverse $F_T$ and the
longitudinal $F_L$ structure function and fix the model parameters from a
global analysis of the world hydrogen electroproduction and photoproduction
cross-section data. We demonstrate a very good performance of the model by
comparing our predictions with data on differential cross sections and the
structure functions $F_2$ and $R=F_L/F_T$.",2103.00158v3
2021-03-10,Narrow Resonances Revisited -- Simplifying Multidimensional Constraints,"As we amass more LHC data, we continue to search for new and improved methods
of visualizing search results, in ways that are as model-independent as
possible. The simplified limits framework is an approach developed to recast
limits on searches for narrow resonances in terms of products of branching
ratios (BRs) corresponding to the resonance's production and decay modes. In
this work, we extend the simplified limits framework to a multidimensional
parameter space of BRs, which can be used to unfold an ambiguity in the
simplified parameter $\zeta$ introduced when more than one channel contributes
to the production of the resonance. It is also naturally applicable to
combining constraints from experimental searches with different observed final
states. Constraints can be visualized in a three-dimensional space of branching
ratios by employing ternary diagrams, triangle plots which utilize the inherent
unitarity of the sum of the resonance's BRs. To demonstrate this new
methodology, we recast constraints from recent ATLAS searches in diboson final
states for spin-0, 1, and 2 narrow resonances into constraints on the
resonance's width-to-mass ratio and display them in the space of relevant
branching ratios. We also demonstrate how to generalize the method to cases
where more than three branching ratios are relevant by using N-simplex
diagrams, and we suggest a broader application of the general method to digital
data sets.",2103.06283v1
2021-04-22,Cylindrical vector beams reveal radiationless anapole condition in a resonant state,"Nonscattering optical anapole condition is corresponding to the excitation of
radiationless field distributions in open resonators, which offers new degrees
of freedom for tailoring light-matter interaction. Conventional mechanisms for
achieving such a condition relies on sophisticated manipulation of
electromagnetic multipolar moments of all orders to guarantee superpositions of
vanished moment strengths at the same wavelength. In contrast, here we report
on the excitation of optical radiationless anapole hidden in a resonant state
of a Si nanoparticle utilizing tightly focused radially polarized (RP) beam.
The coexistence of magnetic resonant state and anapole condition at the same
wavelength further enables the triggering of resonant state by tightly focused
azimuthally polarized (AP) beam whose corresponding electric multipole
coefficient could be zero. As a result, high contrast inter-transition between
radiationless anapole condition and ideal magnetic resonant scattering can be
achieved experimentally in visible spectrum. The proposed mechanism is general
which can be realized in different types of nanostructures. Our results
showcase that the unique combination of structured light and structured Mie
resonances could provide new degrees of freedom for tailoring light-matter
interaction, which might shed new light on functional meta-optics.",2104.10963v1
2021-04-22,"Spin-orbit resonances of high-eccentricity asteroids: regular, switching, and jumping","Few solar system asteroids and comets are found in high eccentricity orbits
($e > 0.9$) but in the primordial planetesimal disks and in exoplanet systems
around dying stars such objects are believed to be common. For 2006 HY51, the
main belt asteroid with the highest known eccentricity 0.9684, we investigate
the probable rotational states today using our computer-efficient chaotic
process simulation method. Starting with random initial conditions, we find
that this asteroid is inevitably captured into stable spin-orbit resonances
typically within tens to a hundred Myr. The resonances are confirmed by direct
integration of the equation of motion in the vicinity of end-points. Most
resonances are located at high spin values above 960 times the mean motion
(such as 964:1 or 4169:4), corresponding to rotation periods of a few days. We
discover three types of resonance in the high-eccentricity regime: 1) regular
circulation with weakly librating aphelion velocities and integer-number
spin-orbit commensurabilities; 2) switching resonances of higher order with
orientation alternating between aligned (0 or $\pi$) and sidewise ($\pi/2$)
angles at aphelia and perihelia; 3) jumping resonances with aphelion spin
alternating between two quantum states in the absence of spin-orbit
commensurability. The islands of equilibrium are numerous at high spin rates
but small in parameter space area, so that it takes millions of orbits of
chaotic wandering to accidentally entrap in one of them. We discuss the
implications of this discovery for the origins and destiny of high-eccentricity
objects and the prospects of extending this analysis to the full 3D treatment.",2104.11338v1
2021-05-08,Coupling microwave photons to topological spin-textures in Cu$_2$OSeO$_3$,"Topologically protected nanoscale spin textures, known as magnetic skyrmions,
possess particle-like properties and feature emergent magnetism effects. In
bulk cubic heli-magnets, distinct skyrmion resonant modes are already
identified using a technique like ferromagnetic resonance in spintronics.
However, direct light-matter coupling between microwave photons and skyrmion
resonance modes has not been demonstrated yet. Utilising two distinct cavity
systems, we realise to observe a direct interaction between the cavity resonant
mode and two resonant skyrmion modes, the counter-clockwise gyration and
breathing modes, in bulk Cu$_2$OSeO$_3$. For both resonant modes, we find the
largest coupling strength at 57 K indicated by an enhancement of the cavity
linewidth at the degeneracy point. We study the effective coupling strength as
a function of temperature within the expected skyrmion phase. We attribute the
maximum in effective coupling strength to the presence of a large number of
skyrmions, and correspondingly to a completely stable skyrmion lattice. Our
experimental findings indicate that the coupling between photons and resonant
modes of magnetic skyrmions depends on the relative density of these
topological particles instead of the pure spin number in the system.",2105.03719v1
2021-05-19,Orbital Decay of Short-Period Exoplanets via Tidal Resonance Locking,"A large fraction of known exoplanets have short orbital periods where tidal
excitation of gravity waves within the host star causes the planets' orbits to
decay. We study the effects of tidal resonance locking, in which the planet
locks into resonance with a tidally excited stellar gravity mode. Because a
star's gravity mode frequencies typically increase as the star evolves, the
planet's orbital frequency increases in lockstep, potentially causing much
faster orbital decay than predicted by other tidal theories. Due to nonlinear
mode damping, resonance locking in Sun-like stars likely only operates for
low-mass planets ($M \lesssim 0.1 \, M_{\rm Jup}$), but in stars with
convective cores it can likely operate for all planetary masses. The orbital
decay timescale with resonance locking is typically comparable to the star's
main-sequence lifetime, corresponding to a wide range in effective stellar
quality factor ($10^3 \lesssim Q' \lesssim 10^9$), depending on the planet's
mass and orbital period. We make predictions for several individual systems and
examine the orbital evolution resulting from both resonance locking and
nonlinear wave dissipation. Our models demonstrate how short-period massive
planets can be quickly destroyed by nonlinear mode damping, while short-period
low-mass planets can survive, even though they undergo substantial inward tidal
migration via resonance locking.",2105.09335v2
2020-02-22,Aluminum Nitride Two-Dimensional-Resonant-Rods,"In the last decades, Bulk-Acoustic-Wave (BAW) filters have been essential
components of 1G-to-4G radios. These devices rely on the high electromechanical
coupling coefficient (kt2~7%), attained by Aluminum Nitride (AlN)
Film-Bulk-Acoustic-Resonators (FBARs), to achieve a wideband and low-loss
frequency response. As the resonance frequency of FBARs is set by their
thickness, the integration of multiple FBARs, to form filters, can only be
attained through the adoption of frequency tuning fabrication steps, such as
mass loading or trimming. However, as the ability to reliably control these
steps significantly decays for thinner FBARs, manufacturing FBARs-based
filters, addressing the needs of emerging IoT and 5G high-frequency
applications, is becoming more and more challenging. Consequently, there is a
quest for new acoustic resonant components, simultaneously exhibiting high kt2
and a lithographic frequency tunability. In this work, a novel class of AlN
resonators is presented. These radio-frequency devices, labelled as
Two-Dimensional-Resonant-Rods (2DRRs), exploit, for the first time, the
unconventional acoustic behavior exhibited by a forest of locally resonant
rods, built in the body of a profiled AlN layer that is sandwiched between a
bottom un-patterned metal plate and a top metallic grating. 2DRRs exhibit
unexplored modal features that make them able to achieve high kt2, a
significant lithographic frequency tunability and a relaxed lithographic
resolution, while relying on an optimal AlN crystalline orientation. The
operation of 2DRRs is discussed, in this work, by means of analytical and
finite-element (FE) investigations. The measured performance of the first
fabricated 2DRR, showing a kt2 in excess of 7.4%, are also reported.",2105.11232v1
2021-06-22,Independently reconfigurable internal loss and resonance-shift in an interferometer-embedded optical cavity,"Optical cavities find diverse uses in lasers, frequency combs, optomechanics,
and optical signal processors. Complete reconfigurability of the resonant
frequency as well as the loss enables development of generic field programmable
cavities for achieving the desired performance in these applications.
Conventional reconfigurable cavities are generally limited to specific material
platforms or specific optical tuning methods and require sophisticated
fabrication. Furthermore, the tuning of the loss is coupled to the
resonance-shift in the cavity. We propose and demonstrate a simple and generic
interferometer in a cavity structure that enables quasiperiodic modification of
the internal cavity loss and the cavity resonance to reconfigure the Q-factor,
transmission characteristics, and group delay of the hybrid cavity, with simple
tuning of the optical phase in the interferometer. We also demonstrate methods
to decouple the tuning of the loss from the resonance-shift, that enables
resonance-locked reconfigurability. This structure also enables resonance-shift
to both shorter and longer wavelengths using the same phase-tuning technique,
which is challenging to achieve in conventional reconfigurable cavities. These
devices can be implemented in any guided-wave platform (on-chip or fiber-optic)
with potential applications in programmable photonics and reconfigurable
optomechanics.",2106.12899v3
2021-07-12,A Five-Planet Resonant Chain: Reevaluation of the Kepler-80 System,"Since the launch of the Kepler space telescope in 2009 and the subsequent K2
mission, hundreds of multi-planet systems have been discovered. The study of
such systems, both as individual systems and as a population, leads to a better
understanding of planetary formation and evolution. Kepler-80, a K-dwarf
hosting six super-Earths, was the first system known to have four planets in a
chain of resonances, a repeated geometric configuration. Transiting planets in
resonant chains can enable us to estimate not only the planets' orbits and
sizes but also their masses. Since the original resonance analysis and TTV
fitting of Kepler-80, a new planet has been discovered whose signal likely
altered the measured masses of the other planets. Here, we determine masses and
orbits for all six planets hosted by Kepler-80 by direct forward photodynamical
modeling of the lightcurve of this system. We then explore the resonant
behaviour of the system. We find that the four middle planets are in a resonant
chain, but that the outermost planet only dynamically interacts in $\sim14$\%
of our solutions. We also find that the system and its dynamic behaviour are
consistent with \emph{in situ} formation and compare our results to two other
resonant chain systems, Kepler-60 and TRAPPIST-1.",2107.05597v1
2021-07-15,Tunable Mie Resonances in the Visible Spectrum,"Dielectric optical nanoantennas play an important role in color displays,
metasurface holograms, and wavefront shaping applications. They usually exploit
Mie resonances as supported on nanostructures with high refractive index, such
as Si and TiO2. However, these resonances normally cannot be tuned. Although
phase change materials, such as the germanium-antimony-tellurium alloys and
post transition metal oxides, such as ITO, have been used to tune optical
antennas in the near infrared spectrum, tunable dielectric antennae in the
visible spectrum remain to be demonstrated. In this paper, we designed and
experimentally demonstrated tunable dielectric nanoantenna arrays with Mie
resonances in the visible spectrum, exploiting phase transitions in
wide-bandgap Sb2S3 nano-resonators. In the amorphous state, Mie resonances in
these Sb2S3 nanostructures give rise to a strong structural color in reflection
mode. Thermal annealing induced crystallization and laser induced amorphization
of the Sb2S3 resonators allow the color to be tuned reversibly. We believe
these tunable Sb2S3 nanoantennae arrays will enable a wide variety of tunable
nanophotonic applications, such as high-resolution color displays, holographic
displays, and miniature LiDAR systems.",2107.07081v1
2021-07-28,On a transitional regime of electron resonant interaction with whistler-mode waves in inhomogeneous space plasma,"Resonances with electromagnetic whistler-mode waves are the primary driver
for the formation and dynamics of energetic electron fluxes in various space
plasma systems, including shock waves and planetary radiation belts. The basic
and most elaborated theoretical framework for the description of the integral
effect of multiple resonant interactions is the quasi-linear theory, that
operates through electron diffusion in velocity space. The quasi-linear
diffusion rate scales linearly with the wave intensity, D(QL) is proportional
to Bw2, which should be small enough to satisfy the applicability criteria of
this theory. Spacecraft measurements, however, often detect whistle-mode waves
sufficiently intense to resonate with electrons nonlinearly. Such nonlinear
resonant interactions imply effects of phase trapping and phase bunching, which
may quickly change the electron fluxes in a non-diffusive manner. Both regimes
of electron resonant interactions (diffusive and nonlinear) are well studied,
but there is no theory quantifying the transition between these two regimes. In
this paper we describe the integral effect of nonlinear electron interactions
with whistler-mode waves in terms of the time-scale of electron distribution
relaxation, is about inverse D(NL). We determine the scaling of D(NL) with wave
intensity Bw2 and other main wave characteristics, such as wave-packet size.
The comparison of D(QL) and D(NL) provides the range of wave intensity and
wave-packet sizes where the electron distribution evolves at the same rates for
the diffusive and nonlinear resonant regimes. The obtained results are
discussed in the context of energetic electron dynamics in the Earth's
radiation belt.",2107.13511v1
2021-08-10,Spiderweb nanomechanical resonators via Bayesian optimization: inspired by nature and guided by machine learning,"From ultra-sensitive detectors of fundamental forces to quantum networks and
sensors, mechanical resonators are enabling next-generation technologies to
operate in room temperature environments. Currently, silicon nitride
nanoresonators stand as a leading microchip platform in these advances by
allowing for mechanical resonators whose motion is remarkably isolated from
ambient thermal noise. However, to date, human intuition has remained the
driving force behind design processes. Here, inspired by nature and guided by
machine learning, a spiderweb nanomechanical resonator is developed that
exhibits vibration modes which are isolated from ambient thermal environments
via a novel ""torsional soft-clamping"" mechanism discovered by the data-driven
optimization algorithm. This bio-inspired resonator is then fabricated;
experimentally confirming a new paradigm in mechanics with quality factors
above 1 billion in room temperature environments. In contrast to other
state-of-the-art resonators, this milestone is achieved with a compact design
which does not require sub-micron lithographic features or complex phononic
bandgaps, making it significantly easier and cheaper to manufacture at large
scales. Here we demonstrate the ability of machine learning to work in tandem
with human intuition to augment creative possibilities and uncover new
strategies in computing and nanotechnology.",2108.04809v2
2021-08-26,Structures of secular resonances for inner test particles in hierarchical planetary systems,"In this study, dynamics of secular resonances for inner test particles are
investigated under the octupole-level approximation by taking non-perturbative
approaches. In practice, webs of the major secular resonances are produced by
identifying families of stable periodic orbits and the associated stable
libration zones are obtained by analysing Poincar\'e surfaces of section. By
taking different values of the factor $\epsilon$ ($\epsilon$ measures the
contribution of octupole terms), the influences of the octupole-order terms
upon the dynamical structures are evaluated. Under the condition of $\epsilon =
0$ (no octupole-order contribution), the dynamical model is totally integrable
and there is only Kozai resonance arising in the phase space. When the factor
$\epsilon$ is different from zero, the dynamical structure in the phase space
becomes complicated due to varieties of secular resonances appearing. Numerical
results further indicate that (a) distributions of libration centres and stable
libration zones remain qualitatively similar with different values of
$\epsilon$, (b) Kozai resonance disappears due to the chaotic motion in the
low-eccentricity region, and (c) the chaotic area arising in the
low-eccentricity region increases with the factor $\epsilon$. Secular
resonances are the source of many important dynamical phenomena, such as chaos,
orbit alignment and orbit flipping, and thus the results presented in this work
could be useful to understand the secular dynamics for those high-eccentricity
and/or high-inclination objects in hierarchical planetary systems.",2108.11532v1
2021-09-22,The dynamics of the TRAPPIST-1 system in the context of its formation,"TRAPPIST-1 is an 0.09 $M_{\odot}$ star, which harbours a system of seven
Earth-sized planets. Two main features stand out: (i) all planets have similar
radii, masses, and compositions; and (ii) all planets are in resonance.
Previous works have outlined a pebble-driven formation scenario where planets
of similar composition form sequentially at the H$_2$O snowline (${\sim}0.1$ au
for this low-mass star). It was hypothesized that the subsequent formation and
migration led to the current resonant configuration. Here, we investigate
whether the sequential planet formation model is indeed capable to produce the
present-day resonant configuration, characterized by its two-body and
three-body mean motion resonances structure. We carry out N-body simulations,
accounting for type-I migration, stellar tidal damping, disc
eccentricity-damping, and featuring a migration barrier located at the disc's
inner edge. Due to the sequential migration, planets naturally form a chain of
first-order resonances. But to explain the period ratios of the b/c/d-system,
which are presently in higher-order resonances, we find that planets b and c
must have marched across the migration barrier, into the gas-free cavity,
before the disc has dispersed. We investigate both an early and late cavity
infall scenario and find that the early infall model best matches the
constraints, as well as being more probable. After the dispersal of the gaseous
disc, stellar tidal torque also contributes towards a modest separation of the
inner system. We outline how the insights obtained in this work can be applied
to aid the understanding of other compact resonant planet systems.",2109.10984v3
2021-10-04,Optimization of the resonator-induced phase gate for superconducting qubits,"The resonator-induced phase gate is a two-qubit operation in which driving a
bus resonator induces a state-dependent phase shift on the qubits equivalent to
an effective $ZZ$ interaction. In principle, the dispersive nature of the gate
offers flexibility for qubit parameters. However, the drive can cause resonator
and qubit leakage, the physics of which cannot be fully captured using either
the existing Jaynes-Cummings or Kerr models. In this paper, we adopt an
ab-initio model based on Josephson nonlinearity for transmon qubits. The
ab-initio analysis agrees well with the Kerr model in terms of capturing the
effective $ZZ$ interaction in the weak-drive dispersive regime. In addition,
however, it reveals numerous leakage transitions involving high-excitation
qubit states. We analyze the physics behind such novel leakage channels,
demonstrate the connection with specific qubits-resonator frequency collisions,
and lay out a plan towards device parameter optimization. We show this type of
leakage can be substantially suppressed using very weakly anharmonic transmons.
In particular, weaker qubit anharmonicity mitigates both collision density and
leakage amplitude, while larger qubit frequency moves the collisions to occur
only at large anharmonicity not relevant to experiment. Our work is broadly
applicable to the physics of weakly anharmonic transmon qubits coupled to
linear resonators. In particular, our analysis confirms and generalizes the
measurement-induced state transitions noted in Sank et al. (Phys. Rev. Lett.
117, 190503) and lays the groundwork for both strong-drive resonator-induced
phase gate implementation and strong-drive dispersive qubit measurement.",2110.01724v1
2021-10-12,Application of the Shannon entropy in the planar (non-restricted) four-body problem: the long-term stability of the Kepler-60 exoplanetary system,"In this paper, we present an application of the Shannon entropy in the case
of the planar (non-restricted) four-body problem. Specifically, the Kepler-60
extrasolar system is being investigated with a primary interest in the resonant
configuration of the planets that exhibit a chain of mean-motion
commensurabilities with the ratios 5:4:3. In the dynamical maps provided, the
Shannon entropy is utilized to explore the general structure of the phase
space, while, based on the time evolution of the entropy, we determine also the
extent and rate of the chaotic diffusion as well as the characteristic times of
stability for the planets. Two cases are considered: (i) the pure Laplace
resonance when the critical angles of the 2-body resonances circulate and that
of the 3-body resonance librates; and (ii) the chain of two 2-body resonances
when all the critical angles librate. Our results suggest that case (ii) is the
more favourable configuration but we state too that, in either case, the
relevant resonance plays an important role to stabilize the system. The derived
stability times are no shorter than $10^8$ yrs in the central parts of the
resonances.",2110.05971v1
2021-11-09,The In Situ Signature of Cyclotron Resonant Heating,"The dissipation of magnetized turbulence is an important paradigm for
describing heating and energy transfer in astrophysical environments such as
the solar corona and wind; however, the specific collisionless processes behind
dissipation and heating remain relatively unconstrained by measurements. Remote
sensing observations have suggested the presence of strong temperature
anisotropy in the solar corona consistent with cyclotron resonant heating. In
the solar wind, in situ magnetic field measurements reveal the presence of
cyclotron waves, while measured ion velocity distribution functions have hinted
at the active presence of cyclotron resonance. Here, we present Parker Solar
Probe observations that connect the presence of ion-cyclotron waves directly to
signatures of resonant damping in observed proton-velocity distributions. We
show that the observed cyclotron wave population coincides with both flattening
in the phase space distribution predicted by resonant quasilinear diffusion and
steepening in the turbulent spectra at the ion-cyclotron resonant scale. In
measured velocity distribution functions where cyclotron resonant flattening is
weaker, the distributions are nearly uniformly subject to ion-cyclotron wave
damping rather than emission, indicating that the distributions can damp the
observed wave population. These results are consistent with active cyclotron
heating in the solar wind.",2111.05400v2
2021-11-12,Fractional resonances and prethermal states in Floquet systems,"In periodically-driven quantum systems, resonances can induce exotic
nonequilibrium behavior and new phases of matter without static analog. We
report on the emergence of fractional and integer resonances in a broad class
of many-body Hamiltonians with a modulated hopping with a frequency that is
either a fraction or an integer of the on-site interaction. We contend that
there is a fundamental difference between these resonances when interactions
bring the system to a Floquet prethermal state. Second-order processes dominate
the dynamics in the fractional resonance case, leading to less entanglement and
more localized quantum states than in the integer resonance case dominated by
first-order processes. We demonstrate the dominating emergence of fractional
resonances using the Magnus expansion of the effective Hamiltonian and quantify
their effects on the many-body dynamics via quantum states' von Neumann entropy
and Loschmidt echo. Our findings reveal novel features of the nonequilibrium
quantum many-body system, such as the coexistence of Floquet prethermalization
and localization, that may allow to development of quantum memories for quantum
technologies and quantum information processing.",2111.06949v4
2021-12-01,Precision measurement of quasi-bound resonances in H$_2$ and the H + H scattering length,"Quasi-bound resonances of H$_2$ are produced via two-photon photolysis of
H$_2$S molecules as reactive intermediates or transition states, and detected
before decay of the parent molecule into three separate atoms. As was
previously reported [K.F. Lai et al., Phys. Rev. Lett. 127, 183001 (2021)] four
centrifugally bound quantum resonances with lifetimes of multiple $\mu$s, lying
energetically above the dissociation limit of the electronic ground state
X$^1\Sigma_g^+$ of H$_2$, were observed as X($v,J$) = (7,21)$^*$, (8,19)$^*$,
(9,17)$^*$, and (10,15)$^*$, while also the short-lived ($\sim 1.5$ ns)
quasi-bound resonance X(11,13)$^*$ was probed. The present paper gives a
detailed account on the identification of the quasi-bound or shape resonances,
based on laser detection via F-X two-photon transitions, and their strongly
enhanced Franck-Condon factors due to the shifting of the wave function density
to large internuclear separation. In addition, the assignment of the rotational
quantum number is verified by subsequent multi-step laser excitation into
autoionization continuum resonances. Existing frameworks of full-fledged ab
initio computations for the bound region in H$_2$, including Born-Oppenheimer,
adiabatic, non-adiabatic, relativistic and quantum-electrodynamic
contributions, are extended into the energetic range above the dissociation
energy. These comprehensive calculations are compared to the accurate
measurements of energies of quasi-bound resonances, finding excellent
agreement. Etc.",2112.00817v1
2022-01-27,Proper elements for resonant planet-crossing asteroids,"Proper elements are quasi-integrals of motion, meaning that they can be
considered constant over a certain timespan, and they permit to describe the
long-term evolution with a few parameters. Near-Earth objects (NEOs) generally
have a large eccentricity and therefore they can cross the orbits of the
planets. Moreover, some of them are known to be currently in a mean-motion
resonance with a planet. Thus, the methods previously used for the computation
of main-belt asteroid proper elements are not appropriate for such objects. In
this paper, we introduce a technique for the computation of proper elements of
planet-crossing asteroids that are in a mean-motion resonance with a planet.
First, we numerically average the Hamiltonian over the fast angles while
keeping all the resonant terms, and we describe how to continue a solution
beyond orbit crossing singularities. Proper elements are then extracted from a
frequency analysis of the averaged orbit-crossing solutions. We give proper
elements of some known resonant NEOs, and provide comparisons with non-resonant
models. These examples show that it is necessary to take into account the
effect of the resonance for the computation of accurate proper elements.",2201.11392v2
2022-02-23,A 5.3 GHz Al0.76Sc0.24N Two-Dimensional Resonant Rods Resonator with a kt2 of 23.9%,"This work reports on the measured performance of an Aluminum Scandium Nitride
(AlScN) Two-Dimensional Resonant Rods resonator (2DRR), fabricated by using a
Sc-doping concentration of 24%, characterized by a low off-resonance impedance
(~25 Ohm) and exhibiting a record electromechanical coupling coefficient (kt2)
of 23.9% for AlScN resonators. In order to achieve such performance, we
identified and relied on optimized deposition and etching processes for
highly-doped AlScN films, aiming at achieving high crystalline quality, low
density of abnormally oriented grains in the 2DRR's active region and sharp
lateral sidewalls. Also, the 2DRR's unit-cell has been acoustically engineered
to maximize the piezo-generated mechanical energy within each rod and to ensure
a low transduction of spurious modes around resonance. Due to its unprecedented
kt2, the reported 2DRR opens exciting scenarios towards the development of next
generation monolithic integrated radio-frequency (RF) filtering components. In
fact, we show that 5th-order 2DRR-based ladder filters with fractional
bandwidths (BW) of ~11%, insertion-loss (I.L) values of ~2.5 dB and with >30 dB
out-of-band rejections can now be envisioned, paving an unprecedented path
towards the development of ultra-wide band (UWB) filters for next-generation
Super-High-Frequency (SHF) radio front-ends.",2202.11284v3
2022-02-23,Secular Spin-orbit Resonances of Black Hole Binaries in AGN Disks,"The spin-orbit misalignment of stellar-mass black hole (sBH) binaries provide
important constraints on the formation channels of merging sBHs. Here, we study
the role of secular spin-orbit resonance in the evolution of a sBH binary
component around a supermassive BH (SMBH) in an AGN disk. We consider the sBH's
spin-precession due to the $J_2$ moment introduced by a circum-sBH disk within
the warping/breaking radius of the disk. We find that the sBH's spin-orbit
misalignment (obliquity) can be excited via spin-orbit resonance between the
sBH binary's orbital nodal precession and the sBH spin-precession driven by a
massive circum-sBH disk. Using an $\alpha$-disk model with
Bondi-Hoyle-Lyttleton accretion, the resonances typically occur for sBH
binaries with semi-major axis of $1$AU, and at a distance of $\sim 1000$AU
around a $10^7$\msun SMBH. The spin-orbit resonances can lead to high sBH
obliquities, and a broad distribution of sBH binary spin-spin misalignments.
However, we note that the Bondi-Hoyle-Lyttleton accretion is much higher than
that of Eddington accretion, which typically results in spin precession being
too low to trigger spin-orbit resonances. Thus, the secular spin-orbit
resonances can be quite rare for sBHs in AGN disks.",2202.11739v2
2022-04-24,Polarization-independent resonant lattice Kerker effect in phase-change metasurface,"Resonant lattice Kerker effect in periodic resonators is one of the most
interesting generalizations of the Kerker effect that relates to various
fascinating functionalities such as scattering management and Huygens
metasurfaces. However, so far this effect has been shown to be sensitive to the
incident polarization, restricting its applications. Here, we report, for the
first time, polarization-independent resonant lattice Kerker effect in
metasurfaces composed of periodic Ge$_2$Se$_2$Te$_5$ (GST) disks. For such a
metasurface of square lattice, the spectrally overlap of the electric dipole
and magnetic dipole surface lattice resonances can be realized by choosing an
appropriate GST crystalline fraction regardless of the incident polarization.
The operation wavelength and the required GST crystalline fraction can be
conveniently tuned over large ranges since these parameters scale linearly with
the disk size and the lattice period, greatly facilitating the design. Making
use of the obtained resonant lattice Kerker effect, we realize a reconfigurable
and polarization-independent lattice Huygens' metasurface with a dynamic phase
modulation of close to $2\pi$ and high transmittance. This work will advance
the engineering of the resonant lattice Kerker effect and promote its
applications in phase modulation and wavefront control.",2204.11311v4
2022-05-12,Power and temperature dependent model for High Q superconductors,"Measuring the internal quality factor of coplanar waveguide superconducting
resonators is an established method of determining small losses in
superconducting devices. Traditionally, the resonator losses are only
attributed to two-level system (TLS) defects using a power dependent model for
the quality factor. However, excess non-equilibrium quasiparticles can also
limit the quality factor of the planar superconducting resonators used in
circuit quantum electrodynamics. At millikelvin temperatures, quasiparticles
can be generated by breaking Cooper pairs via a single high-energy or multiple
sub-gap photons. Here a two-temperature, power and temperature dependent model
is proposed to evaluate resonator losses for isolating TLS and quasiparticle
loss simultaneously. The model combines the conventional TLS power and
temperature dependence with an effective temperature non-equilibrium
quasiparticle description of the superconducting loss. The quasiparticle
description is based on the quasiparticle number density calculated using rate
equations for an external quasiparticle generation source, recombination, and
trapping. The number density is translated to an effective temperature using a
thermal distribution that may be different from the bath. Experimental
measurements of high-quality factor resonators fabricated from single crystal
aluminum and titanium nitride thin films on silicon are interpreted with the
presented model. This approach enables identification of quasiparticle and TLS
loss, resulting in the determination that the TiN resonator has comparable TLS
and quasiparticle loss at low power and low-temperature, while the
low-temperature Al resonator behavior is dominated by non-equilibrium
quasiparticle loss.",2205.06291v1
2022-05-16,Dielectric Mie Voids: Confining Light in Air,"Manipulating light on the nanoscale has become a central challenge in
metadevices, resonant surfaces, nanoscale optical sensors, and many more, and
it is largely based on resonant light confinement in dispersive and lossy
metals and dielectrics. Here, we experimentally implement a novel strategy for
dielectric nanophotonics: Resonant subwavelength confinement of light in air.
We demonstrate that voids created in high-index dielectric host materials
support localized resonant modes with exceptional optical properties. Due to
the confinement in air, the modes do not suffer from the loss and dispersion of
the dielectric host medium. We experimentally realize these resonant Mie voids
by focused ion beam milling into bulk silicon wafers and experimentally
demonstrate resonant light confinement down to the UV spectral range at 265 nm
(4.68 eV). Furthermore, we utilize the bright, intense, and naturalistic
colours for nanoscale colour printing. The combination of resonant dielectric
Mie voids with dielectric nanoparticles will more than double the parameter
space for the future design of metasurfaces and other micro- and nanoscale
optical elements and push their operation into the blue and UV spectral range.
In particular, this extension will enable novel antenna and structure designs
which benefit from the full access to the modal field inside the void as well
as the nearly free choice of the high-index material.",2205.07729v1
2022-05-17,Spin dynamics of positively charged excitons in Cr$^+$-doped quantum dots probed by resonant photoluminescence,"We study the dynamics of the spin system that consist of a positively charged
II-VI semiconductor quantum dot doped with a single Cr$^+$ ion. The resonant
photoluminescence (PL) of the positively charged exciton coupled with the
Cr$^+$ spin is used to analyze the main spin relaxation channels. The intensity
of the resonant PL is reduced by an optical pumping of the spin of the resident
hole-Cr$^+$ complex that can be seen as a nano-magnet. The spin memory can be
partially erased by a non-resonant optical excitation. This leads to an
increase of the resonant PL signal. The resonant PL is co-circularly polarized
and corresponds to relaxation channels that conserve the Cr$^+$ spin $\vert S_z
\vert$. The observation in the resonant-PL excitation spectra of optical
transitions with a change of the Cr$^+$ spin permits to determine the magnetic
anisotropy of the magnetic atom. Optical pumping, auto-correlation measurements
and the power dependence of the PL intensity distribution show that the
effective temperature of the hole-Cr$^+$ spin system is affected by the optical
excitation through the local generation of phonons.",2205.08122v1
2022-05-31,Boosted second-harmonic generation in the LiNbO$\mathrm{_3}$ metasurface governed by high-Q guided resonances and bound states in the continuum,"To date, second-harmonic generation (SHG) at nanoscale has been concentrated
on employing high-refractive-index nanostructures, owing to the strong field
confinement at deep subwavelength scales based on optically resonant effects.
However, low-index nanostructures generally exhibit weaker resonant effects and
lower field confinement. To address this issue, by harnessing the large
nonlinearity of LiNbO$\mathrm{_3}$, we propose a novel approach to employ
guided resonances and bound states in the continuum (BICs) with a
LiNbO$\mathrm{_3}$ metasurface consisting of a LiNbO$\mathrm{_3}$ disk array
sitting on a LiNbO3 thin film. Such a system can transform the guided modes
supported by LiNbO$\mathrm{_3}$ thin film into high-quality guided resonances
which can be excited directly under plane-wave illumination. Importantly, we
further demonstrate strong field confinement inside LiNbO3 thin film with
tailorable Q-factor by realising a Friedrich-Wintgen BIC. Such a unique mode
engineering enables a record-high SHG efficiency of 5\% under a pump intensity
as low as 0.4 $\mathrm{MW/cm^{2}}$. Moreover, we reveal the influence of
nonlinear resonances and cross-coupling on the SHG by showing the anomalous SHG
and efficiency tuning with the rotation of the crystal axis. Our work offers a
new route to constructing enhanced SHG based on high-Q guided resonances and
BICs, including low-index and high-index nonlinear materials.",2205.15482v2
2022-06-01,Persistent nonlinear phase-locking and non-monotonic energy dissipation in micromechanical resonators,"Many nonlinear systems are described by eigenmodes with amplitude-dependent
frequencies, interacting strongly whenever the frequencies become commensurate
at internal resonances. Fast energy exchange via the resonances holds the key
to rich dynamical behavior, such as time-varying relaxation rates and
signatures of nonergodicity in thermal equilibrium, revealed in the recent
experimental and theoretical studies of micro and nanomechanical resonators.
However, a universal yet intuitive physical description for these diverse and
sometimes contradictory experimental observations remains elusive. Here we
experimentally reveal persistent nonlinear phase-locked states occurring at
internal resonances and demonstrate that they are essential for understanding
the transient dynamics of nonlinear systems with coupled eigenmodes. The
measured dynamics of a fully observable micromechanical resonator system are
quantitatively described by the lower frequency mode entering, maintaining, and
exiting a persistent phase-locked period tripling state generated by the
nonlinear driving force exerted by the higher frequency mode. This model
describes the observed phase-locked coherence times, the direction and
magnitude of the energy exchange, and the resulting non-monotonic mode energy
evolution. Depending on the initial relative phase, the system selects distinct
relaxation pathways, either entering or bypassing the locked state. The
described persistent phase-locking is not limited to particular frequency
fractions or types of nonlinearities and may advance nonlinear resonator
systems engineering across physical domains, including photonics as well as
nanomechanics.",2206.01089v1
2022-06-09,Apsidal Alignment and Anti-Alignment of Planets in Mean-Motion Resonance: Disk-Driven Migration and Eccentricity Driving,"Planets migrating in their natal discs can be captured into mean-motion
resonance (MMR), in which the planets' periods are related by integer ratios.
Recent observations indicate that planets in MMR can be either apsidally
aligned or anti-aligned. How these different configurations arise is unclear.
In this paper, we study the MMR capture process of migrating planets, focusing
on the property of the apsidal angles of the captured planets. We show that the
standard picture of MMR capture, in which the planets undergo convergent
migration and experience eccentricity damping due to planet-disc interactions,
always leads to apsidal anti-alignment of the captured planets. However, when
the planets experience eccentricity driving from the disc, apsidally aligned
configuration in MMR can be produced. In this configuration, both planets'
resonance angles circulate, but a ""mixed"" resonance angle librates and traps
the planets near the nominal resonance location. The MMR capture process in the
presence of disc eccentricity driving is generally complex and irregular, and
can lead to various outcomes, including apsidal alignment and anti-alignment,
as well as the disruption of the resonance. We suggest that the two resonant
planets in the K2-19 system, with their moderate eccentricities and aligned
apsides, have experienced eccentricity driving from their natal disc in the
past.",2206.04810v1
2022-06-13,Microwave-activated gates between a fluxonium and a transmon qubit,"We propose and analyze two types of microwave-activated gates between a
fluxonium and a transmon qubit, namely a cross-resonance (CR) and a CPHASE
gate. The large frequency difference between a transmon and a fluxonium makes
the realization of a two-qubit gate challenging. For a medium-frequency
fluxonium qubit, the transmon-fluxonium system allows for a cross-resonance
effect mediated by the higher levels of the fluxonium over a wide range of
transmon frequencies. This allows one to realize the cross-resonance gate by
driving the fluxonium at the transmon frequency, mitigating typical problems of
the cross-resonance gate in transmon-transmon chips related to frequency
targeting and residual ZZ coupling. However, when the fundamental frequency of
the fluxonium enters the low-frequency regime below 100 MHz, the
cross-resonance effect decreases leading to long gate times. For this range of
parameters, a fast microwave CPHASE gate can be implemented using the higher
levels of the fluxonium. In both cases, we perform numerical simulations of the
gate showing that a gate fidelity above 99% can be obtained with gate times
between 100 and 300 ns. Next to a detailed gate analysis, we perform a study of
chip yield for a surface code lattice of fluxonia and transmons interacting via
the proposed cross-resonance gate. We find a much better yield as compared to a
transmon-only architecture with the cross-resonance gate as native two-qubit
gate.",2206.06203v2
2022-06-24,Tutorial: Exciton resonances for atomically-thin optics,"Metasurfaces enable flat optical elements by leveraging optical resonances in
metallic or dielectric nanoparticles to obtain accurate control over the
amplitude and phase of the scattered light. While highly efficient, these
resonances are static and difficult to tune actively. Exciton resonances in
atomically thin 2D semiconductors provide a novel and uniquely strong resonant
light-matter interaction, which presents a new opportunity for optical
metasurfaces. Their resonant properties are intrinsic to the band structure of
the material and do not rely on nanoscale patterns and are highly tunable using
external stimuli. In this tutorial, we present the role that excitons
resonances can play for atomically-thin optics. We describe the essentials of
metasurface physics, provide a background on exciton physics, as well as a
comprehensive overview of excitonic materials. Excitons demonstrate to provide
new degrees of freedom and enhanced light-matter interactions in hybrid
metasurfaces through coupling with metallic and dielectric metasurfaces. Using
the high sensitivity of excitons to the medium's electron density, the first
demonstrations of electrically-tunable nanophotonic devices and atomically-thin
optical elements are also discussed. The future of excitons in metasurfaces
looks promising, while the main challenge lies in large-area growth and precise
integration of high-quality materials.",2206.12175v1
2022-06-27,Emergence of $^4$H $J^π=1^-$ resonance in contact theories,"We obtain the $s$- and $p$-wave low-energy scattering parameters for n$^3$H
elastic scattering and the position of the $^4$H $J^\pi=1^-$ resonance using
the pionless effective field theory at leading order. Results are extracted
with three numerical techniques: confining the system in a harmonic oscillator
trap, solving the Faddeev-Yakubovsky equations in configuration space, and
using an effective two-body cluster approach. The renormalization of the theory
for the relevant amplitudes is assessed in a cutoff-regulator range between
$1\,\text{fm}^{-1}$ and $10\,\text{fm}^{-1}$.
  Most remarkably, we find a cutoff-stable/RG-invariant resonance in the $^4$H
$J^\pi=1^-$ system. This $p$-wave resonance is a universal consequence of a
shallow two-body state and the introduction of a three-body $s$-wave scale set
by the triton binding energy. The stabilization of a resonant state in a
few-fermion system through pure contact interactions has a significant
consequence for the powercounting of the pionless theory. Specifically, it
suggests the appearance of similar resonant states also in larger nuclei, like
16-oxygen, in which the theory's leading order does not predict stable states.
Those resonances would provide a starting state to be moved to the correct
physical position by the perturbative insertion of sub-leading orders, possibly
resolving the discrepancy between data and contact EFT.",2206.13321v2
2022-07-21,Occurrence of gradual resonance in a finite-length granular chain driven by harmonic vibration,"This study presents numerical simulations of the resonance of a finite-length
granular chain of dissipative grains driven by a harmonically vibrated tube.
Multiple gradual resonant modes, namely, non-resonance mode, partial-resonance
mode, and complete-resonance mode, are identified. With a fixed vibration
frequency, increased vibration acceleration leads to a one-by-one increase in
the number of grains participating in resonance, which is equal to the number
of grain-wall collisions in a vibration period. Compared with the
characteristic time of the grain-grain and the grain-wall collisions, the time
of free flight plays a dominant role in grain motion. This condition results in
the occurrence of large opening gaps between the grains and independent
grain-grain and gain-wall collisions. A general master equation that describes
the dependence of the system energy on the length of the granular chain and the
number of grain-wall collisions is established, and it is in good agreement
with the simulation results. We observe a gradual step-jump increase in system
energy when the vibration acceleration is continuously increased, which is
dedicated to an individual energy injection. Moreover, two typical phase
diagrams are discussed in the spaces of $\phi-\it{\Gamma}$ and $N-\it\Gamma$.",2207.10274v1
2022-07-25,Neutrino-induced single pion production and the reanalyzed bubble chamber data,"In this work we report the calculation of the charged current total and
differential cross sections for weak pion-production with neutrinos and
antineutrinos, with the final pion-nucleon pair invariant mass $W_{\pi
N}\lesssim2$GeV. Our results are compared with the recent reanalyzed data from
the old bubble chamber experiments, that solved the discrepancy between the ANL
and BNL data. We implement a model previously tested for the cuts $W_{\pi
N}<1.4,1.6$ Gev which includes explicitly resonances in the first and second
resonance regions, within different approaches for the resonances self energy
and $\frac{3}{2}$-vertexes and propagators, a fact not usually analyzed. Our
model leans on consistent effective Lagrangians that generate resonant
amplitudes together non resonant plus resonant backgrounds. Effects of hadrons
finite extension and more energetic resonances corresponding to the emitted
pion-nucleon invariant mass in the $1.6<W_{\pi N}<2$ GeV region, are taking
into account using appropiate form factors in consistency with previous results
on neutral current pion production calculations. Our results reproduce well the
reanalysed data without cuts and are compared with another models.",2207.12549v1
2022-08-01,Second resonance of the Higgs field: more signals from the LHC experiments,"Theoretical arguments and lattice simulations suggest that, beside the known
resonance of mass $m_h=$ 125 GeV, the Higgs field might exhibit a second
resonance with a larger mass $(M_H)^{\rm theor} = 690 \pm 10 ~({\rm stat}) \pm
20 ~({\rm sys})~ {\rm GeV}$ which, however, would couple to longitudinal W's
with the same typical strength as the low-mass state at 125 GeV and thus
represent a relatively narrow resonance mainly produced at LHC by gluon-gluon
fusion. By looking for some evidence in the LHC data, we argue that the
existence of a new resonance in the predicted mass region finds support in two
analyses by ATLAS (searching for heavy resonances decaying into final states
with 4 charged leptons or $\gamma\gamma$ pairs) and in more recent CMS results
(searching for heavy resonances decaying into a pair of $h(125)$ bosons or
looking for $\gamma\gamma$ pairs produced in $pp$ double-diffractive
scattering). Since the correlation of these measurements is very small and
since, having some definite theoretical prediction, local deviations from the
pure background are not downgraded by the look-elsewhere effect, we emphasize
the instability of the present situation that could probably be resolved by
just adding two crucial, missing samples of RUN2 data.",2208.00920v2
2022-08-03,Orbital dynamics landscape near the most distant known trans-Neptunian objects,"The most distant known trans-Neptunian objects (perihelion distance above 38
au and semimajor axis above 150 au) are of interest for their potential to
reveal past, external, or present but unseen perturbers. Realizing this
potential requires understanding how the known planets influence their orbital
dynamics. We use a recently-developed Poincare mapping approach for orbital
phase space studies of the circular planar restricted three body problem, which
we have extended to the case of the three-dimensional restricted problem with
$N$ planetary perturbers. With this approach, we explore the dynamical
landscape of the 23 most distant TNOs under the perturbations of the known
giant planets. We find that, counter to common expectations, almost none of
these TNOs are far removed from Neptune's resonances. Nearly half (11) of these
TNOs have orbits consistent with stable libration in Neptune's resonances; in
particular, the orbits of TNOs 148209 and 474640 overlap with Neptune's 20:1
and 36:1 resonances, respectively. Five objects can be ruled currently
non-resonant, despite their large orbital uncertainties, because our mapping
approach determines the resonance boundaries in angular phase space in addition
to semimajor axis. Only three objects are in orbital regions not appreciably
affected by resonances: Sedna, 2012 VP113 and 2015 KG163. Our analysis also
demonstrates that Neptune's resonances impart a modest (few percent)
non-uniformity in the longitude of perihelion distribution of the currently
observable distant TNOs. While not large enough to explain the observed
clustering, this small dynamical sculpting of the perihelion longitudes could
become relevant for future, larger TNO datasets.",2208.02248v1
2022-09-02,Ultra-high-Q racetrack microring based on silicon-nitride,"Ultra-high-Q resonators are fundamentally important to optics and microwave
photonics. Up to now, it is still very challenging to boost the Q factor while
maintaining a compact size for a resonator. Herein, we proposed and
demonstrated an ultra-high-Q silicon-nitride (Si3N4) racetrack resonator with
uniform multi-mode Si3N4 photonic waveguides. It consists of two multi-mode
straight waveguides connected by two multi-mode waveguide bends (MWBs). In
particular, the MWBs are based on modified Euler curves, and a multi-mode
straight waveguide directional coupler is used for the fundamental mode
coupling and avoid exciting higher-order modes in the racetrack. In this way,
the fundamental mode is excited and propagates in the multi-mode racetrack
resonator with ultra-low loss. Meanwhile, it helps to achieve a compact
180{\deg} bend to reduce the chip footprint. In this paper, the propagation
loss of the fundamental mode is significantly reduced with standard fabrication
process by broadening the waveguides width to as wide as 3{\mu}m. Results show
that an ultra-high-Q resonator with an intrinsic Q of TE mode is 4.57*10^7, and
the corresponding propagation loss of the waveguide is only 1.80 dB/m. To the
best of our knowledge, this is the highest Q value of the ring resonator with
only 2.226 mm ring length reported so far. The proposed ultra-high-Q Si3N4
resonator can be used to microwave photonic filters and optoelectronic
oscillators with large operation bandwidth.",2209.01097v2
2022-09-10,Resonant mode coupling approximation for calculation of optical spectra of photonic crystal slabs. Part II,"We propose further development of the resonant mode coupling approximation
for the calculation of optical spectra of stacked periodic nanostructures in
terms of the scattering matrix. We previously showed that given the resonant
input and output vectors as well as background scattering matrices of two
subsystems, one can easily calculate those for the combined system comprising
two subsystems. It allows us to write a resonant approximation for the combined
system and speed up calculation significantly for typical calculation problems.
The main drawback of this approach is that the background matrix in such
approximation was considered constant which is not always sufficient if the
energy range of interest is relatively wide. The aim of this article is to
solve this problem by utilizing more complicated approximations for the
background matrices. In particular, we show that consideration of
energy-dependent correction terms for the background matrices remarkably
reduces the resonant energies' calculation error. Here we first consider a
linear approximation, and although it is not suitable for large energy ranges,
it is used as a base for a piecewise-linear approximation which allows one to
keep the approximation error negligibly small with only a few sample points.
Moreover, interpolation of the background matrices allows one to apply resonant
mode coupling approximation in almost arbitrary large energy ranges. We also
consider approximation of background matrices by an arbitrary matrix function
and propose a technique to derive the resonant poles in this case. The methods
described here could be considered as an alternative approach for calculation
of optical spectra stacked systems.",2209.05952v1
2022-09-20,A Rogue Planet Helps Populate the Distant Kuiper Belt,"The orbital distribution of transneptunian objects (TNOs) in the distant
Kuiper Belt (with semimajor axes beyond the 2:1 resonance, roughly $a$=50-100
au) provides constraints on the dynamical history of the outer solar system.
Recent studies show two striking features of this region: 1) a very large
population of objects in distant mean-motion resonances with Neptune, and 2)
the existence of a substantial detached population (non-resonant objects
largely decoupled from Neptune). Neptune migration models are able to implant
some resonant and detached objects during the planet migration era, but many
fail to match a variety of aspects of the orbital distribution. In this work,
we report simulations carried out using an improved version of the GPU-based
code GLISSE, following 100,000 test particles per simulation in parallel while
handling their planetary close encounters. We demonstrate for the first time
that a 2 Earth-mass rogue planet temporarily present during planet formation
can abundantly populate both the distant resonances and the detached
populations, surprisingly even without planetary migration. We show how weak
encounters with the rogue greatly increase the efficiency of filling the
resonances, while also dislodging TNOs out of resonance once they reach high
perihelia. The rogue's secular gravitational influence simultaneously generates
numerous detached objects observed at all semimajor axes. These results suggest
that the early presence of additional planet(s) reproduces the observed TNO
orbital structure in the distant Kuiper Belt.",2209.09399v1
2022-10-10,Ultra-tuning of nonlinear drumhead MEMS resonators by electro-thermoelastic buckling,"Nonlinear micro-electro-mechanical systems (MEMS) resonators open new
opportunities in sensing and signal manipulation compared to their linear
counterparts by enabling frequency tuning and increased bandwidth. Here, we
design, fabricate and study drumhead resonators exhibiting strongly nonlinear
dynamics and develop a reduced order model (ROM) to capture their response
accurately. The resonators undergo electrostatically-mediated thermoelastic
buckling which tunes their natural frequency from 4.7 to 11.3 MHz, a factor of
2.4x tunability. Moreover, the imposed buckling switches the nonlinearity of
the resonators between purely stiffening, purely softening, and even
softening-to-stiffening. Accessing these exotic dynamics requires precise
control of the temperature and the DC electrostatic forces near the resonator's
critical-buckling point. To explain the observed tunability, we develop a
one-dimensional physics-based ROM that predicts the linear and nonlinear
response of the fundamental bending mode of these drumhead resonators. The ROM
captures the dynamic effects of the internal stresses resulting from three
sources: The residual stresses from the fabrication process, the mismatch in
thermal expansion between the constituent layers, and lastly, the applied
electrostatic forces. The ROM replicates the observed tunability of linear
(within 5.5% error) and nonlinear responses even near the states of critical
buckling. These remarkable nonlinear and large tunability of the natural
frequency are valuable features for on-chip acoustic devices in broad
applications such as signal manipulation, filtering, and MEMS waveguides.",2210.06982v1
2022-10-19,Spectral engineering of integrated photonic filters using mode splitting in silicon nanowire integrated standing-wave resonators,"Mode splitting induced by coherent optical mode interference in coupled
resonant cavities is a key phenomenon in photonic resonators that can lead to
powerful and versatile filtering functions, in close analogy to
electromagnetically-induced-transparency, Autler-Townes splitting, Fano
resonances, and dark states. It can not only break the dependence between
quality factor, free spectral range, and physical cavity length, but can also
lead to group delay response and mode interactions that are useful for
enhancing light-material interaction and dispersion engineering in nonlinear
optics. In this work, we investigate mode splitting in standing-wave (SW)
resonators implemented by cascaded Sagnac loop reflectors (CSLRs) and
demonstrate its use for engineering the spectral profile of integrated photonic
filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs) and
the phase shifts along the connecting waveguides, we tailor mode splitting in
the CSLR resonators to achieve a wide range of filter shapes for diverse
applications including enhanced light trapping, flat-top filtering, Q factor
enhancement, and signal reshaping. We present the theoretical designs and
compare the performance of CSLR resonators with three, four, and eight SLRs
fabricated in silicon-on-insulator nanowires. We achieve high performance and
versatile filter shapes via diverse mode splitting that agree well with theory.
The experimental results confirm the effectiveness of our approach towards
realizing integrated multi-functional SW filters for flexible spectral
engineering.",2210.10224v1
2022-10-11,Theory of Truncation Resonances in Continuum Rod-based Phononic Crystals with Generally Asymmetric Unit Cells,"Phononic crystals exhibit Bragg bandgaps, frequency regions within which wave
propagation is forbidden. In solid continua, bandgaps are the outcome of
destructive interferences resulting from periodically alternating layers. Under
certain conditions, natural frequencies emerge within these bandgaps in the
form of high-amplitude localized vibrations near a structural boundary,
referred to as truncation resonances. In this paper, we investigate the
vibrational spectrum of finite phononic crystals which take the form of a
one-dimensional rod, and explain the factors that contribute to the origination
of truncation resonances. By identifying a unit cell symmetry parameter, we
define a family of finite phononic rods which share the same dispersion
relation, yet distinct truncated forms. A transfer matrix method is utilized to
derive closed-form expressions of the characteristic equations governing the
natural frequencies of the finite system and decipher the truncation resonances
emerging across different boundary conditions. The analysis establishes
concrete connections between the localized vibrations associated with a
truncation resonance, boundary conditions, and the overall configuration of the
truncated chain as dictated by unit cell choice. The study provides tools to
predict, tune, and selectively design truncation resonances, to meet the
demands of various applications that require and uniquely benefit from such
truncation resonances.",2211.01423v3
2022-11-06,Fano resonances in all-dielectric electromagnetic metasurfaces,"We are interested in the resonant electromagnetic (EM) scattering by
all-dielectric metasurfaces made of a two-dimensional lattice of nanoparticles
with high refractive indices. In [Ammari et al., Trans. AMS, 376 (2023),
39-90], it has been shown that a single high-index nanoresonator can couple
with the incident wave and exhibit a strong magnetic dipole response. Recent
physics experiments reveal that when the particles are arranged in certain
periodic configurations, they may have different anomalous scattering effects
in the macroscopic scale, compared to the single-particle case. In this work,
we shall develop a rigorous mathematical framework for analyzing the resonant
behaviors of all-dielectric metasurfaces. We start with the characterization of
subwavelength scattering resonances in such a periodic setting and their
asymptotic expansions in terms of the refractive index of the nanoparticles.
Then we show that real resonances always exist below the essential spectrum of
the periodic Maxwell operator and that they are the simple poles of the
scattering resolvent with the exponentially decaying resonant modes. By using
group theory, we discuss the implications of the symmetry of the metasurface on
the subwavelength band functions and their associated eigenfunctions. For the
symmetric metasurfaces with the normal incidence, we use a variational method
to show the existence of embedded eigenvalues (i.e., real subwavelength
resonances embedded in the continuous radiation spectrum). Furthermore, we
break the configuration symmetry either by introducing a small deformation of
particles or by slightly deviating from the normal incidence and prove that
Fano-type reflection and transmission anomalies can arise in both of these
scenarios.",2211.03224v3
2022-12-07,Surfing in the phase space of spin-orbit coupling in binary asteroid systems,"For a satellite with an irregular shape, which is the common shape among
asteroids, the well-known spin-orbit resonance problem could be changed to a
spin-orbit coupling problem since a decoupled model does not accurately capture
the dynamics of the system. In this paper, having provided a definition for
close binary asteroid systems, we explore the structure of the phase space in a
classical Hamiltonian model for spin-orbit coupling in a binary system. To map
out the geography of resonances analytically and the cartography of resonances
numerically, we reformulate a fourth-order gravitational potential function, in
Poincare variables, via Stokes coefficients. For a binary system with a
near-circular orbit, isolating the Hamiltonian near each resonance yields the
pendulum model. Analysis of the results shows the geographical information,
including the location and width of resonances, is modified due to the
prominent role of the semi-major axis in the spin-orbit coupling model but not
structurally altered. However, this resulted in modified Chirikov criterion to
predict onset of large-scale chaos. For a binary system with arbitrary closed
orbit, we thoroughly surf in the phase space via cartography of resonances
created by fast Lyapunov indicator (FLI) maps. The numerical study confirms the
analytical results, provides insight into the spin-orbit coupling, and shows
some bifurcations in the secondary resonances which can occur due to material
transfer. Also, we take the (65803) Didymos binary asteroid as a case to show
analytical and numerical results.",2212.03837v1
2023-01-05,Resonant triad interactions of gravity waves in cylindrical basins,"We present the results of a theoretical investigation into the existence,
evolution and excitation of resonant triads of nonlinear free-surface gravity
waves confined to a cylinder of finite depth. It is well known that resonant
triads are impossible for gravity waves in laterally unbounded domains; we
demonstrate, however, that horizontal confinement of the fluid may induce
resonant triads for particular fluid depths. For any three correlated wave
modes arising in a cylinder of arbitrary cross-section, we prove necessary and
sufficient conditions for the existence of a depth at which nonlinear resonance
may arise, and show that the resultant critical depth is unique. We enumerate
the low-frequency triads for circular cylinders, including a new class of
resonances between standing and counter-propagating waves, and also briefly
discuss annular and rectangular cylinders. Upon deriving the triad amplitude
equations for a finite-depth cylinder of arbitrary cross-section, we deduce
that the triad evolution is always periodic, and determine parameters
controlling the efficiency of energy exchange. In order to excite a particular
triad, we explore the influence of external forcing; in this case, the triad
evolution may be periodic, quasi-periodic, or chaotic. Finally, our results
have potential implications on resonant water waves in man-made and natural
basins, such as industrial-scale fluid tanks, harbours and bays.",2301.02163v2
2023-01-30,Evolution of binary systems accompanying axion clouds in extreme mass ratio inspirals,"Superradiant instability of rotating black holes (BHs) leads to the formation
of a cloud of ultralight bosons, such as axions. When the BH with the cloud
belongs to a binary system and is in an inspiraling orbit, the resonant
transition between the axion's bound states can occur. We study the history of
the evolution of the binary system accompanying the cloud composed of the
fastest growing mode, and its impact on the observational signatures,
especially for small mass ratio cases. In this case, the hyperfine resonance,
which has a very small resonance frequency, is relevant. Therefore, due to the
long timescale, we should take into account the decaying process of axions in
the transition destination mode, the backreaction to the orbital motion and the
central BH, and gravitational emission from the cloud. We present a formulation
to examine the evolution of the system around the resonance and useful
expressions for the analysis. As a result, we found the mass of the cloud that
can remain after the resonance is, at most, about $10^{-5}$ of the central BH.
The maximum remaining cloud mass is achieved when the mass ratio of the binary
is $q\sim10^{-3}$. In addition, we show that the resonant transition hardly
changes the BH mass and spin distribution, while the associated modification of
the gravitational wave frequency evolution when the binary pass through the
resonance can be a signature of the presence of the cloud.",2301.13213v2
2023-02-10,Booster Free From Spin Resonance For Future 100~km-scale Circular e$^{+}$e$^{-}$ Colliders,"Acceleration of polarized electron~(positron) beams in a booster synchrotron
may suffer from depolarization due to crossings of many spin depolarization
resonances, which could limit its applications. We have studied the spin
depolarization resonance structure of a 100~km scale booster lattice of the
Circular Electron Positron Collider~(CEPC). The lattice has 8 arc regions with
hundreds of FODO cells, interleaved with straight sections, which leads to a
high periodicity. Our analysis shows the contributions to the strength of
intrinsic and imperfection spin resonances add up coherently near the super
strong resonances beyond 120 GeV, but mostly cancel out and result in generally
weak resonance strengths at lower beam energies. Detailed simulations confirm
that beam polarization can be mostly maintained in the fast acceleration to
45.6 GeV and 80 GeV, but severe depolarization may occur at even higher
energies. This study suggests the possibility of acceleration of polarized
electron~(positron) beams to ultra-high beam energies without the help of
Siberian snakes, and supports injecting highly polarized beams into the
collider rings as an attractive solution for resonant depolarization
measurements and longitudinal polarized colliding beam experiments for future
100~km scale circular e$^{+}$e$^{-}$ colliders.",2302.05321v2
2023-02-16,Maps of secular resonances in the NEO region,"Context. From numerical simulations, it is known that some secular resonances
may affect the motion of near-Earth objects (NEOs). However, the specific
location of the secular resonance inside the NEO region is not fully known,
because the methods previously used to predict their location can not be used
for highly eccentric orbits and when the NEOs cross the orbits of the planets.
  Aims. In this paper, we aim to map the secular resonances with the planets
from Venus to Saturn in the NEO region, even for high values of the
eccentricity.
  Methods. We used an averaged semi-analytical model that can deal with orbit
crossing singularities for the computation of the secular dynamics of NEOs,
from which we can obtain suitable proper elements and proper frequencies. Then,
we computed the proper frequencies over a uniform grid in the proper elements
space. Secular resonances are thus located by the level curves corresponding to
the proper frequencies of the planets.
  Results. We determined the location of the secular resonances with the
planets from Venus to Saturn, showing that they appear well inside the NEO
region. By using full numerical N-body simulations we also showed that the
location predicted by our method is fairly accurate. Finally, we provided some
indications about possible dynamical paths inside the NEO region, due to the
presence of secular resonances.",2302.08126v1
2023-02-21,Characterizing non-Markovian Off-Resonant Errors in Quantum Gates,"As quantum gates improve, it becomes increasingly difficult to characterize
the remaining errors. Here we describe a class of coherent non-Markovian errors
-- excitations due to an off-resonant drive -- that occur naturally in quantum
devices that use time-dependent fields to generate gate operations. We show how
these errors are mischaracterized using standard Quantum Computer Verification
and Validation (QCVV) techniques that rely on Markovianity and are therefore
often overlooked or assumed to be incoherent. We first demonstrate off-resonant
errors within a simple toy model of Z-gates created by the AC Stark effect,
then show how off-resonant errors manifest in all gates driven on a
fixed-frequency transmon architecture, a prominent example being incidental
cross-resonance interaction driven during single-qubit gates. Furthermore, the
same methodology can access the errors caused by two-level systems (TLS),
showing evidence of coherent, off-resonant interactions with subsystems that
are not intentional qubits. While we explore these results and their impact on
gate error for fixed-frequency devices, we note that off-resonant excitations
potentially limit any architectures that use frequency selectivity.",2302.10881v2
2023-02-28,Stellar halo substructure generated by bar resonances,"Using data from the Gaia satellite's Radial Velocity Spectrometer Data
Release 3 (RVS, DR3), we find a new and robust feature in the phase space
distribution of halo stars. It is a prominent ridge at constant energy and with
angular momentum $L_z>0$. We run test particle simulations of a stellar
halo-like distribution of particles in a realistic Milky Way potential with a
rotating bar. We observe similar structures generated in the simulations from
the trapping of particles in resonances with the bar, particularly at the
corotation resonance. Many of the orbits trapped at the resonances are
halo-like, with large vertical excursions from the disc. The location of the
observed structure in energy space is consistent with a bar pattern speed in
the range $\Omega_\mathrm{b}\approx35-40$ km s$^{-1}$ kpc$^{-1}$. Overall, the
effect of the resonances is to give the inner stellar halo a mild, net spin in
the direction of the bar's rotation. As the distribution of the angular
momentum becomes asymmetric, a population of stars with positive mean $L_z$ and
low vertical action is created. The variation of the average rotational
velocity of the simulated stellar halo with radius is similar to the behaviour
of metal-poor stars in data from the APOGEE survey. Though the effects of bar
resonances have long been known in the Galactic disc, this is strong evidence
that the bar can drive changes even in the diffuse and extended stellar halo
through its resonances.",2303.00008v2
2023-05-09,"Experimentally verified, fast analytic and numerical design of superconducting resonators in flip-chip architectures","In superconducting quantum processors, the predictability of device
parameters is of increasing importance as many labs scale up their systems to
larger sizes in a 3D-integrated architecture. In particular, the properties of
superconducting resonators must be controlled well to ensure high-fidelity
multiplexed readout of qubits. Here we present a method, based on conformal
mapping techniques, to predict a resonator's parameters directly from its 2D
cross-section, without computationally heavy and time-consuming 3D simulation.
We demonstrate the method's validity by comparing the calculated resonator
frequency and coupling quality factor with those obtained through 3D
finite-element-method simulation and by measurement of 15 resonators in a
flip-chip-integrated architecture. We achieve a discrepancy of less than 2%
between designed and measured frequencies, for 6-GHz resonators. We also
propose a design method that reduces the sensitivity of the resonant frequency
to variations in the inter-chip spacing.",2305.05502v3
2023-05-17,Do different kinds of photon-pair sources have the same indistinguishability in quantum silicon photonics?,"In the same silicon photonic integrated circuit, we compare two types of
integrated degenerate photon-pair sources (microring resonators or waveguides)
by means of Hong-Ou-Mandel (HOM) interference experiments. Two nominally
identical microring resonators are coupled to two nominally identical
waveguides which form the arms of a Mach-Zehnder interferometer. This is pumped
by two lasers at two different wavelengths to generate, by spontaneous
four-wave mixing, degenerate photon pairs. In particular, the microring
resonators can be thermally tuned in or out of resonance with the pump
wavelengths, thus choosing either the microring resonators or the waveguides as
photon-pair sources, respectively. In this way, an on-chip HOM visibility of
94% with microring resonators and 99% with straight waveguides is measured upon
filtering. We compare our experimental results with theoretical simulations of
the joint spectral intensity and the purity of the degenerate photon pairs. We
verify that the visibility is connected to the sources' indistinguishability,
which can be quantified by the overlap between the joint spectral amplitudes
(JSA) of the photon pairs generated by the two sources. We estimate a JSAs
overlap of 98% with waveguides and 89% with microring resonators.",2305.10066v2
2023-05-30,Dynamic resonance fluorescence in solid-state cavity quantum electrodynamics,"The coherent interaction between a two-level system and electromagnetic
fields serves as a foundation for fundamental quantum physics and modern
photonic quantum technology. A profound example is resonance fluorescence,
where the non-classical photon emission appears in the form of a Mollow-triplet
when a two-level system is continuously driven by a resonant laser. Pushing
resonance fluorescence from a static to dynamic regime by using short optical
pulses generates on-demand emissions of highly coherent single photons. Further
increasing the driving strength in the dynamical regime enables the pursuit of
exotic non-classical light emission in photon number superposition, photon
number entanglement, and photon bundle states. However, the long-sought-after
spectrum beyond the Mollow-triplet, a characteristic of dynamic resonance
fluorescence under strong driving strength, has not been observed yet. Here we
report the direct observation and systematic investigations of dynamic
resonance fluorescence spectra beyond the Mollow-triplet in a solid-state
cavity quantum electrodynamic system. The dynamic resonance fluorescence
spectra with up to five pairs of side peaks, excitation detuning induced
spectral asymmetry, and cavity filtering effect are observed and quantitatively
modeled by a full quantum model with phonon scattering included. Time-resolved
measurements further reveal that the multiple side peaks originate from
interference of the emission associated with different temporal positions of
the excitation pulses. Our work facilitates the generation of a variety of
exotic quantum states of light with dynamic driving of two-level systems.",2305.18776v1
2023-06-14,Fano resonances for tilted linear and quadratic band touching dispersions in a harmonically driven potential well,"Considering models with tilted linear and quadratic band touching
dispersions, we analyze the effect of the transverse linear tilt on the
transmission spectra through a harmonically driven potential well oriented
longitudinally. Employing the Floquet scattering matrix formalism, we find Fano
resonances as an outcome of matching between the Floquet sidebands and
quasi-bound states, where the tilt renormalizes their energies and wave
vectors. We find that the Fano resonance energy decreases (increases) for
linear (quadratic) band touchings as the magnitude of the transverse momentum
increases, indicating a distinct signature of the underlying band dispersion in
the transmission profile. The sign of the product of the transverse momentum
and the tilt also determines the relative shift in the Fano resonance energy
with respect to the untilted case for both band dispersions, suggesting a
possible tunability of the Fano resonance for tilted systems. Importantly, the
tilt strength can also be directly determined by measuring the Fano resonance
energy as function of the transverse momenta direction. We furthermore study
the shot noise spectra and their differential property where we find an
inflection region and undulation, respectively, around the Fano resonance
energy. Interestingly, differential shot noise and transmission spectra both
qualitatively behave in a similar fashion and might thus serve as important
observables for future experiments on driven solid-state systems.",2306.08759v2
2023-06-28,High-Q trenched aluminum coplanar resonators with an ultrasonic edge microcutting for superconducting quantum devices,"Dielectric losses are one of the key factors limiting the coherence of
superconducting qubits. The impact of materials and fabrication steps on
dielectric losses can be evaluated using coplanar waveguide (CPW) microwave
resonators. Here, we report on superconducting CPW microwave resonators with
internal quality factors systematically exceeding 5x106 at high powers and
2x106 (with the best value of 4.4x106) at low power. Such performance is
demonstrated for 100-nm-thick aluminum resonators with 7-10.5 um center trace
on high-resistivity silicon substrates commonly used in quantum Josephson
junction circuits. We investigate internal quality factors of the resonators
with both dry and wet aluminum etching, as well as deep and isotropic reactive
ion etching of silicon substrate. Josephson junction compatible CPW resonators
fabrication process with both airbridges and silicon substrate etching is
proposed. Finally, we demonstrate the effect of airbridges positions and extra
process steps on the overall dielectric losses. The best quality fa ctors are
obtained for the wet etched aluminum resonators and isotropically removed
substrate with the proposed ultrasonic metal edge microcutting.",2306.16301v1
2023-07-29,Enhanced Size Uniformity for Near-resonant Planets,"Super-Earths within the same close-in, compact planetary system tend to
exhibit a striking degree of uniformity in their radius, mass, and orbital
spacing, and this 'peas-in-a-pod' phenomenon itself serves to provide one of
the strongest constrains on planet formation at large. While it has been
recently demonstrated from independent samples that such planetary uniformity
occurs for both configurations near and distant from mean motion resonance, the
question thus remains if the strength of this uniformity itself differs between
near-resonant and nonresonant configurations such that the two modes may be
astrophysically distinct in their evolution. We thus provide in this work a
novel comparative size uniformity analysis for 48 near-resonant and 251
nonresonant multi-planet systems from the California Kepler Survey catalog,
evaluating uniformity both across systems and between planetary pairs within
the same system. We find that while multiplanet configurations exhibit strong
peas-in-a-pod size uniformity regardless of their proximity to resonance,
near-resonant configurations display enhanced intra-system size uniformity as
compared to their analogous nonresonant counterparts at the level of both
entire systems and subsystem planetary pairs and chains. These results are
broadly consistent with a variety of formation paradigms for multiplanet
systems, such as convergent migration within a turbulent protoplanetary disk or
planet-planet interactions incited by postnebular dynamical instabilities.
Nevertheless, further investigation is necessary to ascertain whether the
nonresonant and near-resonant planetary configurations respectively evolve via
a singular process or mechanisms that are dynamically distinct.",2307.15875v2
2023-07-29,Effects of Phi and $σ^{*}$-meson on properties of hyperon stars including $Δ$ resonance,"In this work, we study the properties of neutron stars using the linear
Relativistic Mean-Field (RMF) theory and consider multiple degrees of freedom
inside neutron stars, including hyperons and $\Delta$ resonances. We
investigate different coupling parameters $x_{\sigma \Delta}$ between $\Delta$
resonances and nucleons and compare the differences between neutron stars with
and without strange mesons $\sigma^*$ and $\phi$. These effects include
particle number distributions, equations of state (EOS), mass-radius relations,
and tidal deformabilities. To overcome the ""hyperon puzzle,"" we employ the
$\sigma-cut$ scheme to obtain neutron stars with masses up to $2M_{\odot}$. We
find that strange mesons appear at around 3$\rho_0$ and reduce the critical
density of baryons in the high-density region. With increasing coupling
parameter $x_{\sigma \Delta}$, the $\Delta$ resonances suppress hyperons,
leading to a shift of the critical density towards lower values. The early
appearance of $\Delta$ resonances may play a crucial role in the stability of
neutron stars. Strange mesons soften the EOS slightly, while $\Delta$
resonances predominantly soften the EOS in the low-density region. By
calculating tidal deformabilities and comparing with astronomical observation
GW170817, we find that the inclusion of $\Delta$ resonances decreases the
radius of neutron stars.",2308.00007v3
2023-08-16,Polarized and narrow excitonic emission from graphene-capped monolayer WS$_2$ through resonant phonon relaxation,"The broadening and polarization of excitonic luminescence in monolayer TMDs
largely suffer from inhomogeneity and temperature - an unresolved problem to
date. In this work, through few-layer-graphene encapsulation of monolayer
WS$_2$, we reduce the inter-excitonic energy separation, which then can have a
narrow resonance with a specific phonon mode of our choice. The resulting
single-step exciton relaxation with the resonating phonon mode significantly
suppresses the inhomogeneous broadening, allowing us to achieve the narrowest
exciton linewidth of 1.06 meV (which translates to 0.19 meV after deconvolution
with the excitation laser linewidth). The single-phonon resonance helps to
achieve a high quantum efficiency despite graphene encapsulation. The technique
is powerful in tuning the exciton polarization during relaxation by choosing a
specific resonating phonon mode. For example, the valley coherence
(polarization) improves from $\sim$68% ($\sim$40%) to $\sim$90% ($\sim$75%) on
resonance with 2$A_1$' and $A_1$' modes respectively. We further demonstrate a
strong polarization reversal on resonance with a chiral phonon mode.
Strikingly, the above features remain robust against temperature (up to 200 K)
and sample age (few months in ambient condition). The findings will lead to
clean excitonic measurements without requiring cryogenic cooling.",2308.08637v1
2023-08-31,Resonance contributions to nucleon spin structure in Holographic QCD,"We study polarized inelastic electron-nucleon scattering at low momentum
transfer in the Witten-Sakai-Sugimoto model of holographic QCD, focusing on
resonance production contributions to the nucleon spin structure functions. Our
analysis includes both spin $3/2$ and spin $1/2$ low-lying nucleon resonances
with positive and negative parity. We determine, in turn, the helicity
amplitudes for nucleon-resonance transitions and the resonance contributions to
the neutron and proton generalized spin polarizabilities. Extrapolating the
model parameters to realistic QCD data, our analysis, triggered by recent
experimental results from Jefferson Lab, agrees with the observation that the
$\Delta(1232)$ resonance gives the dominant contribution to the forward spin
polarizabilities at low momentum transfer. The contribution is negative and
tends to zero as the momentum transfer increases. As expected, the contribution
of the $\Delta(1232)$ to the longitudinal-transverse polarizabilities is
instead negligible. The latter, for both nucleons, turn out the be negative
functions with zero asymptote. The holographic results, at least for the proton
where enough data are available, are in qualitative agreement with the
resonance contributions to the spin polarizabilities extracted from
experimental data on the helicity amplitudes.",2308.16833v2
2023-09-18,Schrieffer-Wolff transformation for non-Hermitian systems: application for $\mathcal{PT}$-symmetric circuit QED,"Combining non-hermiticity and interactions yields novel effects in open
quantum many-body systems. Here, we develop the generalized Schrieffer-Wolff
transformation and derive the effective Hamiltonian suitable for various
quasi-degenerate \textit{non-Hermitian} systems. We apply our results to an
exemplary $\mathcal{PT}$--symmetric circuit QED composed of two non-Hermitian
qubits embedded in a lossless resonator. We consider a resonant quantum circuit
as $|\omega_r-\Omega| \ll \omega_r$, where $\Omega$ and $\omega_r$ are qubits
and resonator frequencies, respectively, providing well-defined groups of
quasi-degenerate resonant states. For such a system, using direct numerical
diagonalization we obtain the dependence of the low-lying eigenspectrum on the
interaction strength between a single qubit and the resonator, $g$, and the
gain (loss) parameter $\gamma$, and compare that with the eigenvalues obtained
analytically using the effective Hamiltonian of resonant states. We identify
$\mathcal{PT}$--symmetry broken and unbroken phases, trace the formation of
Exceptional Points of the second and the third order, and provide a complete
phase diagram $g-\gamma$ of low-lying resonant states. We relate the formation
of Exceptional Points to the additional $\mathcal{P}$-pseudo-Hermitian symmetry
of the system and show that non-hermiticity mixes the ""dark"" and the ""bright""
states, which has a direct experimental consequence.",2309.09829v1
2023-09-27,Mean-Motion Resonances With Interfering Density Waves,"In this work, we study the dynamics of two less massive objects moving around
a central massive object, which are all embedded within a thin accretion disc.
In addition to the gravitational interaction between these objects, the
disc-object interaction is also crucial for describing the long-term dynamics
of the multi-body system, especially in the regime of mean-motion resonances.
We point out that near the resonance the density waves generated by the two
moving objects generally coherently interfere with each other, giving rise to
extra angular momentum fluxes. The resulting backreaction on the objects is
derived within the thin-disc scenario, which explicitly depends on the resonant
angle and sensitively depends on the smoothing scheme used in the
two-dimensional theory. We have performed hydrodynamical simulations with
planets embedded within a thin accretion disc and have found qualitatively
agreement on the signatures of interfering density waves by measuring the
torques on the embedded objects. By including in interference torque and the
migration torques in the evolution of a pair of planets, we show that the
chance of resonance trapping depends on the sign of the interference torque.
For negative torques the pairs are more likely located at off-resonance
regimes. The negative torques may also explain the $1\%-2\%$ offset (for the
period ratios) from the exact resonance values as observed in {\it Kepler}
multi-planet systems.",2309.15694v2
2023-09-28,Constraining Ultralight Dark Matter through an Accelerated Resonant Search,"Experiments aimed at detecting ultralight dark matter typically rely on
resonant effects, which are sensitive to the dark matter mass that matches the
resonance frequency. In this study, we investigate the nucleon couplings of
ultralight axion dark matter using a magnetometer operating in a nuclear
magnetic resonance (NMR) mode. Our approach involves the use of a $^{21}$Ne
spin-based sensor, which features the lowest nuclear magnetic moment among
noble-gas spins. This configuration allows us to achieve an ultrahigh
sensitivity of 0.73 fT/Hz$^{1/2}$ at around 5 Hz, corresponding to energy
resolution of approximately 1.5$\times
  10^{-23}\,\rm{eV/Hz^{1/2}}$. Our analysis reveals that under certain
conditions it is beneficial to scan the frequency with steps significantly
larger than the resonance width. The analytical results are in agreement with
experimental data and the scan strategy is potentially applicable to other
resonant searches. Further, our study establishes stringent constraints on
axion-like particles (ALP) in the 4.5--15.5 Hz Compton-frequency range coupling
to neutrons and protons, improving on prior work by several-fold. Within a band
around 4.6--6.6 Hz and around 7.5 Hz, our laboratory findings surpass
astrophysical limits derived from neutron-star cooling. Hence, we demonstrate
an accelerated resonance search for ultralight dark matter, achieving an
approximately 30-fold increase in scanning step while maintaining competitive
sensitivity.",2309.16600v1
2023-10-19,Direct programming of confined Surface Phonon Polariton Resonators using the plasmonic Phase-Change Material In$_3$SbTe$_2$,"Tailoring light-matter interaction is essential to realize nanophotonic
components. It can be achieved with surface phonon polaritons (SPhPs), an
excitation of photons coupled with phonons of polar crystals, which also occur
in 2d materials such as hexagonal boron nitride or anisotropic crystals.
Ultra-confined resonances are observed by restricting the SPhPs to cavities.
Phase-change materials (PCMs) enable non-volatile programming of these cavities
based on a change in the refractive index. Recently, the new plasmonic PCM
In$_3$SbTe$_2$ (IST) was introduced which can be reversibly switched from an
amorphous dielectric state to a crystalline metallic one in the entire infrared
to realize numerous nanoantenna geometries. However, reconfiguring SPhP
resonators to modify the confined polaritons modes remains elusive. Here, we
demonstrate direct programming of confined SPhP resonators by phase-switching
IST on top of a polar silicon carbide crystal and investigate the strongly
confined resonance modes with scanning near-field optical microscopy.
Reconfiguring the size of the resonators themselves result in enhanced mode
confinements up to a value of $\lambda/35$. Finally, unconventional cavity
shapes with complex field patterns are explored as well. This study is a first
step towards rapid prototyping of reconfigurable SPhP resonators that can be
easily transferred to hyperbolic and anisotropic 2d materials.",2310.12841v1
2023-12-08,Metamaterial-Controlled Parity-Time Symmetry in Non-Hermitian Wireless Power Transfer Systems,"Inductive wireless power transfer (WPT) systems can be effectively described
as non-Hermitian systems using the coupled-mode theory. In these systems,
parity-time (PT) symmetric states facilitate efficient power transfer.
Traditionally, passive resonators have been used as relay devices in such
systems to extend transmission distance; however, this approach may induce
additional eigenstates with broken PT symmetry, particularly when specific
spatial arrangements of the relay resonators, dependent on the positions of the
transmitting (Tx) and receiving (Rx) resonators, are not maintained. This
limitation hampers applications like free positioning WPT. To address this
challenge, we introduce a multibody WPT system employing metamaterial
controlled PT symmetry, which circumvents the constraints of physical
arrangement. We utilize inverse design to configure the metamaterial, targeting
a specific resonance mode that controls the effective coupling coefficients.
Our approach ensures that a PT-symmetric state emerges when these coefficients,
relating to the metamaterial and both the Tx and Rx resonators, are balanced.
We confirm the stability of this state in a strong coupling regime, both
theoretically and experimentally. Our experiments demonstrate the formation of
PT-symmetric states governed by the metamaterial's resonant mode, achievable
even with varying sizes and positions of the Tx and Rx in relation to the
metamaterial. Moreover, we show that the PT symmetric state is attainable with
different spatial configurations of the Rx resonator. This finding underscores
our system's potential for free-positioning WPT, significantly broadening its
applicability.",2312.04829v2
2024-01-07,The role of resonator neuron in the dynamics of two coupled integrator and resonator neurons of different types of excitability,"In this manuscript, a silent resonator neuron is coupled with a spiking
integrator neuron through the gap junction, when the coupled neurons are of
different types of excitability and none of the coupled neurons exhibit mixed
mode oscillations and bursting oscillations intrinsically. By using dynamical
systems theory (e.g. the bifurcation theory), all the observed oscillation
patterns and the transition mechanisms between them are investigated, when one
of the coupling strengths is fixed and the other is varied. It is noticeable
that, there is an interval in the parameter space, for the parameter values
within which the coupled system is multi-stable. This multistability
corresponds to the coexistence of mixed mode oscillations, bursting
oscillations and subthreshold oscillations of the resonator neuron. In
addition, some interval in the parameter space is introduced such that, for the
values of the coupling strength within which the resonator neuron is in tonic
spiking mode, while for the values of the coupling strength outside which the
resonator neuron exhibits subthreshold oscillations. It is also verified that
the final synchronization of the coupled neurons actually corresponds to the
synchronization of tonic spiking oscillations of the integrator neuron and
one-bursting oscillations of the resonator neuron.",2401.03419v1
2024-02-02,Approximating Accelerator Impedances with Resonator Networks,"It is common in the accelerator community to use the impedance of accelerator
components to describe wake interactions in the frequency domain. However, it
is often desirable to understand such wake interactions in the time domain in a
general manner for excitations that are not necessarily Gaussian in nature. The
conventional method for doing this involves taking the inverse Fourier
Transform of the component impedance, obtaining the Green's Function, and then
convolving it with the desired excitation distribution. This method can prove
numerically cumbersome, for a convolution integral must be evaluated for each
individual point in time when the wake function is desired. An alternative to
this method would be to compute the wake function analytically, which would
sidestep the need for repetitive integration. Only a handful of cases, however,
are simple enough for this method to be tenable. One of these cases is the case
where the component in question is an RLC resonator, which has a closed-form
analytical wake function solution. This means that a component which can be
represented in terms of resonators can leverage this solution. As it happens,
common network synthesis techniques may be used to map arbitrary impedance
profiles to RLC resonator networks in a manner the accelerator community has
yet to take advantage of. In this work, we will use Foster Canonical Resonator
Networks and partial derivative descent optimization to develop a technique for
synthesizing resonator networks that well approximate the impedances of
real-world accelerator components. We will link this synthesis to the
closed-form resonator wake function solution, giving rise to a powerful
workflow that may be used to streamline beam dynamics simulations.",2402.01937v1
2024-02-07,Resonant Chains and the Convergent Migration of Planets in Protoplanetary Disks,"An increasing number of compact planetary systems with multiple planets in a
resonant chain have been detected. The resonant chain must be maintained by
convergent migration of the planets due to planet-disk interactions if it is
formed before the dispersal of the protoplanetary gas disk. For type I
migration in an adiabatic disk, we show that an analytic criterion for
convergent migration can be developed by requiring that any part of the
resonant chain should be convergently migrating toward the remaining part. The
criterion depends primarily on the logarithmic gradients $\alpha$ and $\beta$
of the surface density and temperature profiles of the disk, respectively, and
it is independent of the absolute values of the surface density and
temperature. The analytic criterion is applied to the Kepler-60, Kepler-80,
Kepler-223, TOI-178, and TRAPPIST-1 systems. Due to the variation of planetary
masses within the resonant chains, we find that convergent migration typically
requires rather extreme values of $(\alpha, \beta)$ that have little or no
overlap with common disk models. Finally, we show that there is an empirical
relationship between the distance of the innermost planet from the central star
and the stellar mass for the observed resonant chain systems, which supports
the idea that the resonant chains are formed and maintained by stalling the
migration of the innermost planet near the inner edge of the disk truncated by
the magnetic fields of the protostar.",2402.05183v1
2024-02-18,Polarization-dependent resonant phenomena in all-dielectric scatterers: inversion of magnetic inductance and electric displacement,"The theoretical description and experimental verification of resonant
phenomena in electromagnetic fields generated in the near zone of
all-dielectric rectangular thin sub wavelength frames, subjected to an incident
microwave, is considered. The geometry of considered problems is presented by
means of arrangements of these frames in three orthogonal planes, normal
respectively to electric component, magnetic component and wave vector of the
incident wave. Such trio paves the way to design of 3D all-dielectric
multiresonant microwave unit cell. Displacement currents, generated by linearly
polarized electromagnetic waves in the system, lead to the formation of
magnetic and electric dipoles, each of which possess own resonant frequency.
Resonant inversion of magnetic inductance and electric displacement is
observed. The sliding incidence of plane wave on the frame is shown to provide
the sharp and deep resonance in the components of generated field. The phase
shift equal to $\pi$ between the magnetic components of incident and generated
wave indicates the formation of negative magnetic response. There observes the
angular anisotropy of arising dipoles, manifested in values of resonance
frequencies and in the dependence of depths of resonant spectral dips upon the
orientation of dipoles, with respect to the direction of propagation of
incident wave.",2402.11509v1
2024-02-19,"Vacancy-Induced Topological Fano Resonance in Kane-Mele Nanoribbons: Design, Control, and Sensing Applications","The concept of topological Fano resonance, characterized by an ultrasharp
asymmetric line shape, is a promising candidate for robust sensing applications
due to its sensitivity to external parameters and immunity to structural
disorder. In this study, the vacancy-induced topological Fano resonance in a
nanoribbon made up of a hexagonal lattice with armchair sides is examined by
introducing several on-site vacancies, which are deliberately created at
regular distances, along a zigzag chain that stretches across the width of the
ribbon. The presence of the on-site vacancies can create localized energy
states within the electronic band structure, leading to the formation of an
impurity band, which can result in Fano resonance phenomena by forming a
conductivity channel between the edge modes on both armchair sides of the
ribbon. Consequently, an ultracompact tunable on-chip integrated topological
Fano resonance derived from the graphene-based nanomechanical phononic crystals
is proposed. The Fano resonance arises from the interference between
topologically protected even and odd edge modes at the interface between
trivial and nontrivial insulators in a nanoribbon structure governed by the
Kane-Mele model describing the quantum spin Hall effect in hexagonal lattices.
The simulation of the topological Fano resonance is performed analytically
using the Lippmann-Schwinger scattering formulation. One of the advantages of
the present study is that the related calculations are carried out
analytically, and in addition to the simplicity and directness, it reproduces
the results obtained from the Landauer-B\""{u}ttiker formulation very well both
quantitatively and qualitatively. The findings open up possibilities for the
design of highly sensitive and accurate robust sensors for detecting extremely
tiny forces, masses, and spatial positions.",2402.12119v1
2024-02-19,Nanomechanical crystalline AlN resonators with high quality factors for quantum optoelectromechanics,"High-$Q_m$ mechanical resonators are crucial for applications where low noise
and long coherence time are required, as mirror suspensions, quantum cavity
optomechanical devices, or nanomechanical sensors. Tensile strain in the
material enables the use of dissipation dilution and strain engineering
techniques, which increase the mechanical quality factor. These techniques have
been employed for high-$Q_m$ mechanical resonators made from amorphous
materials and, recently, from crystalline materials such as InGaP, SiC, and Si.
A strained crystalline film exhibiting substantial piezoelectricity expands the
capability of high-$Q_m$ nanomechanical resonators to directly utilize
electronic degrees of freedom. In this work we realize nanomechanical
resonators with $Q_m$ up to $2.9\times 10^{7}$ made from tensile-strained 290
nm-thick AlN, which is an epitaxially-grown crystalline material offering
strong piezoelectricity. We demonstrate nanomechanical resonators that exploit
dissipation dilution and strain engineering to reach a $Q_m \times f_m$-product
approaching $10^{13}$ Hz at room temperature. We realize a novel resonator
geometry, triangline, whose shape follows the Al-N bonds and offers a central
pad that we pattern with a photonic crystal. This allows us to reach an optical
reflectivity above 80% for efficient coupling to out-of-plane light. The
presented results pave the way for quantum optoelectromechanical devices at
room temperature based on tensile-strained AlN.",2402.12196v1
2024-02-23,Variation in whispering gallery mode of resonance in a trapped and levitated liquid micro cavity,"Whispering gallery mode (WGM) of resonance occurs when a traveling wave faces
grazing reflection and confinement at the inner surface of a spherical cavity.
Such a resonance was observed with micrometer sized liquid droplet and with
light of sub-micron wavelength. The resonance occurs when specific boundary
conditions are fulfilled, following a relation between optical path length
(that is related to radius of the droplet) and resonating wavelength.
Therefore, a change in WGM wavelength will be related to dimension of the
droplet. We observed a shift in such a resonance spectra. For a smaller droplet
the observed blue shift in the WGM were 1.5, 0.7, 3.7 nm. Following the
resonance condition, it was estimated that such a shift corresponds to a
reduction in radius of the droplet by 1.3, 0.6, 3.3 nm respectively. This was
obtained with a droplet of radius about 600 nm. The droplet was created from a
solution of glycerol, methanol and rhodamine 6G dye, and was trapped and
levitated in a modified Paul trap. The WGMs were created by optically exciting
the dye material from an external 532 nm cw laser beam. A shift in the WGM was
observed with time, during a gradual increase in power of the excitation laser,
and a reason for such a shift was thought to be thermal evaporation of the
liquid from the droplet. For a larger droplet an initial 0.1 nm thermal
expansion was also estimated because initially a red-shift of the WGM was
observed, probably because of thermal expansion, which was negligible for a
smaller droplet. For the smaller droplet, the estimated rate of change of WGM
with radius, was 1.129. For larger droplet, this rate is lower.",2402.15291v1
2024-02-09,Thermal oscillations and resonance in electron-phonon interaction process,"Thermal resonance, in which the temperature amplitude attains a maximum value
(peak) in response to an external exciting frequency source, is a phenomenon
pertinent to the presence of underdamped thermal oscillations and explicit
finite-speed for the thermal wave propagation. The present work investigates
the occurrence condition for thermal resonance phenomenon during the
electron-phonon interaction process in metals based on the hyperbolic
two-temperature model. First, a sufficient condition for underdamped electron
and lattice temperature oscillations is discussed by deriving a critical
frequency (a material characteristic). It is shown that the critical frequency
of thermal waves near room temperature, during electron-phonon interactions,
may be on the order of terahertz ($10-20$ THz for Cu and Au, i.e., lying within
the terahertz gap). It is found that whenever the natural frequency of metal
temperature exceeds this frequency threshold, the temperature oscillations are
of underdamped type. However, this condition is not necessary, since there is a
small frequency domain, below this threshold, in which the underdamped thermal
wave solution is available but not effective. Otherwise, the critical damping
and the overdamping conditions of the temperature waves are determined
numerically for a sample of pure metals. The thermal resonance conditions in
both electron and lattice temperatures are investigated. The occurrence of
resonance in both electron and lattice temperature is conditional on violating
two distinct critical values of frequencies. When the natural frequency of the
system becomes larger than these two critical values, an applied frequency
equal to such a natural frequency can drive both electron and lattice
temperatures to resonate together with different amplitudes and behaviors.
However, the electron temperature resonates earlier than the lattice
temperature.",2403.09684v1
2024-03-15,Exact time-evolving scattering states in open quantum-dot systems with an interaction: Discovery of time-evolving resonant states,"We study exact time-evolving many-electron states of an open double
quantum-dot system with an interdot Coulomb interaction. A systematic
construction of the time-evolving states for arbitrary initial conditions is
proposed. For any initial states of one- and two-electron plane waves on the
electrical leads, we obtain exact solutions of the time-evolving scattering
states, which converge to known stationary scattering eigenstates in the
long-time limit. For any initial states of localized electrons on the quantum
dots, we find exact time-evolving states of a new type, which we refer to as
time-evolving resonant states. In contrast to stationary resonant states, whose
wave functions spatially diverge and not normalizable, the time-evolving
resonant states are normalizable since their wave functions are restricted to a
finite space interval due to causality. The exact time-evolving resonant states
enable us to calculate the time-dependence of the survival probability of
electrons on the quantum dots for the system with the linearized dispersions.
It decays exponentially in time on one side of an exponential point of
resonance energies while, on the other side, it oscillates during the decay as
a result of the interference of the two resonance energies.",2403.10251v1
2024-03-22,Four-body Semileptonic Decays $B\to D^*P\ell^+ν_\ell$ with the SU(3) Flavor Symmetry,"We present a complete study of the $B\to
D^*P\ell^+\nu_\ell~(\ell=e,\mu,\tau)$ decays with the non-resonant, the charmed
axial vector resonant and the charmed tensor resonant contributions by using
the SU(3) flavor symmetry. Relevant amplitude relations between different decay
modes are obtained by the SU(3) flavor symmetry. We then predict non-measured
branching ratios of the $B\to D^*P\ell^+\nu_\ell$ decays with the non-resonant
and the charmed resonant contributions by using present experimental data of
the $B\to D^*P\ell'^+\nu_{\ell'}~(\ell'=e,\mu)$ decays within $2\sigma$ errors.
We have found that $B^{0,+}\to D^*\eta\ell^+\nu_\ell$, $B^{0,+}\to
D^*\eta'\ell^+\nu_\ell$, $B^{0}_s\to D^*_s \eta\ell^+\nu_\ell$, $B^{0}_s\to
D^*_s\eta'\ell^+\nu_\ell$ and $B^{0,+}\to D^{*}_sK\ell^+\nu_\ell$ decays only
receive non-resonant contributions. Decays $B^0_s\to
D_s^{*-}\pi^0\ell^+\nu_\ell$ only receive the $D'_{s1}$ resonant contributions.
Other decays receive all three kinds of contributions, and three kinds of
contributions are important in most of decays.",2403.14929v1
1996-03-05,Resonant Relaxation in Stellar Systems,"We demonstrate the existence of an enhanced rate of angular momentum
relaxation in nearly Keplerian star clusters, such as those found in the
centers of galactic nuclei containing massive black holes. The enhanced
relaxation arises because the radial and azimuthal orbital frequencies in a
Keplerian potential are equal, and hence may be termed {\em resonant
relaxation}. We explore the dynamics of resonant relaxation using both
numerical simulations and order-of-magnitude analytic calculations. We find
that the resonant angular momentum relaxation time is shorter than the
non-resonant relaxation time by of order $M_\star/M$, where $M_\star$ is the
mass in stars and $M$ is the mass of the central object. Resonance does not
enhance the energy relaxation rate. We examine the effect of resonant
relaxation on the rate of tidal disruption of stars by the central mass; we
find that the flux of stars into the loss cone is enhanced when the loss cone
is empty, but that the disruption rate averaged over the entire cluster is not
strongly affected. We show that relativistic precession can disable resonant
relaxation near the main-sequence loss cone for black hole masses comparable to
those in galactic nuclei. Resonant dynamical friction leads to growth or decay
of the eccentricity of the orbit of a massive body, depending on whether the
distribution function of the stars is predominantly radial or tangential. The
accelerated relaxation implies that there are regions in nuclear star clusters
that are relaxed in angular momentum but not in energy; unfortunately, these
regions are not well-resolved in nearby galaxies by the Hubble Space Telescope.",9603018v1
1998-04-06,Three-dimensional waves generated at Lindblad resonances in thermally stratified disks,"We analyze the linear, 3D response to tidal forcing of a disk that is thin
and thermally stratified in the direction normal to the disk plane. We model
the vertical disk structure locally as a polytrope which represents a disk of
high optical depth. We solve the 3D gas-dynamic equations semi-analytically in
the neighborhood of a Lindblad resonance. These solutions match asymptotically
on to those valid away from resonances and provide solutions valid at all
radii. We obtain the following results. 1) A variety of waves are launched at
resonance. However, the f mode carries more than 95% of the torque exerted at
the resonance. 2) These 3D waves collectively transport exactly the amount of
angular momentum predicted by the 2D torque formula. 3) Near resonance, the f
mode occupies the full vertical extent of the disk. Away from resonance, the f
mode becomes confined near the surface of the disk, and, in the absence of
other dissipation mechanisms, damps via shocks. The radial length scale for
this process is roughly r_L/m (for resonant radius r_L and azimuthal wavenumber
m), independent of the disk thickness H. This wave channeling process is due to
the variations of physical quantities in r and is not due to wave refraction.
4) However, the inwardly propagating f mode launched from an m=2 inner Lindblad
resonance experiences relatively minor channeling.
  We conclude that for binary stars, tidally generated waves in highly
optically thick circumbinary disks are subject to strong nonlinear damping by
the channeling mechanism, while those in circumstellar accretion disks are
subject to weaker nonlinear effects. We also apply our results to waves excited
by young planets for which m is approximately r/H and conclude that the waves
are damped on the scale of a few H.",9804063v1
2005-06-27,On the V-type asteroids outside the Vesta family. I. Interplay of nonlinear secular resonances and the Yarkovsky effect: the cases of 956 Elisa and 809 Lundia,"Among the largest objects in the main belt, asteroid 4 Vesta is unique in
showing a basaltic crust. It is also the biggest member of the Vesta family,
which is supposed to originate from a large cratering event about 1 Gyr ago
(Marzari et al. 1996). Most of the members of the Vesta family for which a
spectral classification is available show a V-type spectra. Before the
discovery of 1459 Magnya (Lazzaro et al. 2000) and of several V-type NEA (Xu
1995), all the known V-type asteroids were members of the Vesta family.
Recently two V-type asteroids, 809 Lundia and 956 Elisa, (Florczak et al. 2002)
have been discovered well outside the limits of the family, near the Flora
family. We currently know 22 V-type asteroids outside the family, in the inner
asteroid belt. In this work we investigate the possibility that these objects
are former family members that migrated to their current positions via the
interplay of Yarkovsky effect and nonlinear secular resonances. The main
dynamical feature of 956 Elisa and 809 Lundia is that they are currently inside
the 2(g-g6)+s-s6 (z2 by Milani and Knezevic, 1993) secular resonance. Our
investigations show that members of the Vesta dynamical family may drift in
three-body and weak secular resonances until they are captured in the strong z2
secular resonance. Only asteroids with diameters larger than 16 km can remain
in one of the three-body or secular resonances long enough to reach the region
of the z2 resonance. This two-step mechanism of capture into the z2 resonance
could explain: i) the current resonant orbits of 956 Elisa and 809 Lundia, ii)
why their size is significantly larger than that of the typical member of the
Vesta family, and iii) provide a lower limit on the Vesta family age.",0506656v1
2007-08-01,Spin measurements for 147Sm+n resonances: Further evidence for non-statistical effects,"We have determined the spins J of resonances in the 147Sm(n,gamma) reaction
by measuring multiplicities of gamma-ray cascades following neutron capture.
Using this technique, we were able to determine J values for all but 14 of the
140 known resonances below En = 1 keV, including 41 firm J assignments for
resonances whose spins previously were either unknown or tentative. These new
spin assignments, together with previously determined resonance parameters,
allowed us to extract separate level spacings and neutron strength functions
for J = 3 and 4 resonances. Furthermore, several statistical test of the data
indicate that very few resonances of either spin have been missed below En =
700eV. Because a non-statistical effect recently was reported near En = 350 eV
from an analysis of 147Sm(n,alpha) data, we divided the data into two regions;
0 < En < 350 eV and 350 < En < 700 eV. Using neutron widths from a previous
measurement and published techniques for correcting for missed resonances and
for testing whether data are consistent with a Porter-Thomas distribution, we
found that the reduced-neutron-width distribution for resonances below 350 eV
is consistent with the expected Porter-Thomas distribution. On the other hand,
we found that reduced-neutron-width data in the 350 < En < 700 eV region are
inconsistent with a Porter-Thomas distribution, but in good agreement with a
chi-squared distribution having two or more degrees of freedom. We discuss
possible explanations for these observed non-statistical effects and their
possible relation to similar effects previously observed in other nuclides.",0708.0218v1
2008-02-14,Constraints on resonant-trapping for two planets embedded in a protoplanetary disc,"We investigate the evolution of two-planet systems embedded in a
protoplanetary disc, which are composed of a Jupiter-mass planet plus another
body located further out in the disc. We consider outermost planets with masses
ranging from 10 earth masses to 1 M_J. We also examine the case of outermost
bodies with masses < 10 earth masses (M_E). Differential migration of the
planets due to disc torques leads to different evolution outcomes depending on
the mass of the outer protoplanet. For planets with mass < 3.5 M_E the type II
migration rate of the giant exceeds the type I migration rate of the outer
body, resulting in divergent migration. Outer bodies with masses in the range
3.5 < m_o < 20 M_E become trapped at the edge of the gap formed by the giant
planet, because of corotation torques. Higher mass planets are captured into
resonance with the inner planet. If 30 < m_o < 40 M_E or m_o=1 M_J, then the
2:1 resonance is established. If 80 < m_o < 100 M_E, the 3:2 resonance is
favoured. Simulations of gas-accreting protoplanets of mass m_o > 20 M_E,
trapped initially at the edge of the gap, or in the 2:1 resonance, also result
in eventual capture in the 3:2 resonance as the planet mass grows to become
close to the mass of Saturn. Our results suggest that there is a theoretical
lower limit to the mass of an outer planet that can be captured into resonance
with an inner Jovian planet, which is relevant to observations of extrasolar
multiplanet systems. Furthermore, capture of a Saturn-like planet into the 3:2
resonance with a Jupiter-like planet is a very robust outcome of simulations.
This result is relevant to recent scenarios of early Solar System evolution
which require Saturn to have existed interior to the 2:1 resonance with Jupiter
prior to the onset of the Late Heavy Bombardment.",0802.2033v1
2008-12-23,Black Holes Admitting Strong Resonant Phenomena,"High-frequency twin peak quasiperiodic oscillations (QPOs) are observed in
four microquasars, i.e., Galactic black hole binary systems, with frequency
ratio very close to 3:2. In the microquasar GRS 1915+105, the structure of QPOs
exhibits additional frequencies, and more than two frequencies are observed in
the Galaxy nuclei Sgr A*, or in some extragalactic sources (NGC 4051,
MCG-6-30-15 and NGC 5408 X-1). The observed QPOs can be explained by a variety
of the orbital resonance model versions assuming resonance of oscillations with
the Keplerian frequency or the vertical epicyclic frequency, and the radial
epicyclic frequency, or some combinations of these frequencies. Generally,
different resonances could arise at different radii of an accretion disc.
However, we have shown that for special values of dimensionless black hole spin
strong resonant phenomena could occur when different resonances can be excited
at the same radius, as cooperative phenomena between the resonances may work in
such situations. The special values of black hole spin are determined for
triple frequency ratio sets \nu_{K} : \nu_{\theta} : \nu_{r} = s:t:u with s, t,
u being small integers. The most promising example of such a special situation
arises for black holes with extraordinary resonant spin a = 0.983 at the radius
r = 2.395 M, where \nu_{K} : \nu_{\theta} : \nu_{r} = 3:2:1. We also predict
that when combinations of the orbital frequencies are allowed, QPOs with four
frequency ratio set 4:3:2:1 could be observed in the field of black holes with
a = 0.866, 0.882 and 0.962. Assuming the extraordinary resonant spin a = 0.983
in Sgr A*, its QPOs with observed frequency ratio very close to 3:2:1 imply the
black hole mass in the interval 4.3 x 10^6 M_sun < M < 5.4 x 10^6 M_sun, in
agreement with estimates given by other, independent, observations.",0812.4418v1
2009-09-01,Characterization of the Resonant Caustic Perturbation,"Four of nine exoplanets found by microlensing were detected by the resonant
caustic, which represents the merging of the planetary and central caustics at
the position when the projected separation of a host star and a bounded planet
is s~1. One of the resonant caustic lensing events, OGLE-2005-BLG-169, was a
caustic-crossing high-magnification event with $A_{max} \sim$ 800 and the
source star was much smaller than the caustic, nevertheless the perturbation
was not obviously apparent on the light curve of the event. In this paper, we
investigate the perturbation pattern of the resonant caustic to understand why
the perturbations induced by the caustic do not leave strong traces on the
light curves of high-magnification events despite a small source/caustic size
ratio. From this study, we find that the regions with
small-magnification-excess around the center of the resonant caustic are rather
widely formed, and the event passing the small-excess region produces a
high-magnification event with a weak perturbation that is small relative to the
amplification caused by the star and thus does not noticeably appear on the
light curve of the event. We also find that the positive excess of the inside
edge of the resonant caustic and the negative excess inside the caustic become
stronger and wider as $q$ increases, and thus the resonant caustic-crossing
high-magnification events with the weak perturbation occur in the range of $q
\leqslant 10^{-4}$. We determine the probability of the occurrence of events
with the small excess $|\epsilon| \leqslant 3 %$ in high-magnification events
induced by a resonant caustic. As a result, we find that for the Earth-mass
planets with a separation of ~ 2.5 AU, the resonant caustic high-magnification
events with the weak perturbation can occur with a significant frequency.",0909.0112v1
2010-08-24,Dirac point resonances due to atoms and molecules adsorbed on graphene and transport gaps and conductance quantization in graphene nanoribbons with covalently bonded adsorbates,"We present a tight binding theory of the Dirac point resonances due to
adsorbed atoms and molecules on an infinite 2D graphene sheet based on the
standard tight binding model of the graphene p-band electronic structure and
the extended Huckel model of the adsorbate and nearby graphene carbon atoms.
The relaxed atomic geometries of the adsorbates and graphene are calculated
using density functional theory. Our model includes the effects of the local
rehybridization of the graphene from the sp^2 to sp^3 electronic structure that
occurs when adsorbed atoms or molecules bond covalently to the graphene. Unlike
in previous tight-binding models of Dirac point resonances, adsorbed species
with multiple extended molecular orbitals and bonding to more than one graphene
carbon atom are treated. More accurate and more general analytic expressions
for the Green's function matrix elements that enter the T-matrix theory of
Dirac point resonances than have been available previously are obtained. We
study H, F, OH and O adsorbates on graphene and for each we find a strong
scattering resonance (two resonances for O) near the Dirac point of graphene,
by far the strongest and closest to the Dirac point being the resonance for H.
We extract a minimal set of tight binding parameters that can be used to model
resonant electron scattering and electron transport in graphene and graphene
nanostructures with adsorbed H, F, OH and O accurately and efficiently. We also
compare our results for the properties of Dirac point resonances due to
adsorbates on graphene with those obtained by others using density functional
theory-based electronic structure calculations, and discuss their relative
merits. We then present calculations of electronic quantum transport in
graphene nanoribbons with these adsorbed species...",1008.4110v2
2011-01-04,Cratered Lorentzian response of driven microwave superconducting nanowire-bridged resonators: oscillatory and magnetic-field induced stochastic states,"Microwave Fabry-Perot resonators containing nonlinear mesoscopic elements
(such as superconducting nanowires) can be used to explore many-body circuit
QED. Here, we report on observations of a superconductor-normal pulsing regime
in microwave (GHz) coplanar waveguide resonators consisting of superconducting
MoGe films interrupted by a gap that is bridged by one or more suspended
superconducting nanowires. This regime, which involve MHz-frequency
oscillations in the amplitude of the supercurrent in the resonator, are
achieved when the steady-state amplitude of the current in the driven resonator
exceeds the critical current of the nanowires. Thus we are able to determine
the temperature dependence of the critical current, which agrees well with the
corresponding Bardeen formula. The pulsing regime manifests itself as an
apparent ""crater"" on top of the fundamental Lorentzian peak of the resonator.
Once the pulsing regime is achieved at a fixed drive power, however, it remains
stable for a range of drive frequencies corresponding to subcritical steady
state currents in the resonator. We develop a phenomenological model of
resonator-nanowire systems, from which we are able to obtain a quantitative
description of the amplitude oscillations and also, inter alia, to investigate
thermal relaxation processes in superconducting nanowires. For the case of
resonators comprising two parallel nanowires and subject to an external
magnetic field, we find field-driven oscillations of the onset power for the
amplitude oscillations, as well as the occurrence (for values of the magnetic
field that strongly frustrate the nanowires) of a distinct steady state in
which the pulsing is replaced by stochastic amplitude-fluctuations. We conclude
by giving a brief discussion of how circuit-QED-based systems have the
potential to facilitate understanding of quantum phase-slips in superconducting
nanowires.",1101.0817v1
2012-06-19,Resonance bifurcations of robust heteroclinic networks,"Robust heteroclinic cycles are known to change stability in resonance
bifurcations, which occur when an algebraic condition on the eigenvalues of the
system is satisfied and which typically result in the creation or destruction
of a long-period periodic orbit. Resonance bifurcations for heteroclinic
networks are more complicated because different subcycles in the network can
undergo resonance at different parameter values, but have, until now, not been
systematically studied. In this article we present the first investigation of
resonance bifurcations in heteroclinic networks. Specifically, we study two
heteroclinic networks in $\R^4$ and consider the dynamics that occurs as
various subcycles in each network change stability. The two cases are
distinguished by whether or not one of the equilibria in the network has real
or complex contracting eigenvalues. We construct two-dimensional Poincare
return maps and use these to investigate the dynamics of trajectories near the
network. At least one equilibrium solution in each network has a
two-dimensional unstable manifold, and we use the technique developed in [18]
to keep track of all trajectories within these manifolds. In the case with real
eigenvalues, we show that the asymptotically stable network loses stability
first when one of two distinguished cycles in the network goes through
resonance and two or six periodic orbits appear. In the complex case, we show
that an infinite number of stable and unstable periodic orbits are created at
resonance, and these may coexist with a chaotic attractor. There is a further
resonance, for which the eigenvalue combination is a property of the entire
network, after which the periodic orbits which originated from the individual
resonances may interact. We illustrate some of our results with a numerical
example.",1206.4328v1
2012-12-01,Adiabatic Chemical Freeze-out and Wide Resonance Modification in a Thermal Medium,"Here we develop a model equation of state which successfully parameterizes
the thermodynamic functions of hadron resonance gas model at chemical
freeze-out and which allows us to naturally explain the adiabatic chemical
freeze-out criterion. The present model enables us to clearly demonstrate that
at chemical freeze-out the resulting hadronic mass spectrum used in the hadron
resonance gas model is not an exponential-like, but a power-like. We argue that
such a property of hadronic mass spectrum at chemical freeze-out can be
explained by the two new effects found here for wide resonances existing in a
thermal environment: the near threshold thermal resonance enhancement and the
near threshold resonance sharpening. The effect of resonance sharpening is
studied for a sigma meson and our analysis shows that for the temperatures well
below 92 MeV the effective width of sigma meson is about 50 to 70 MeV. Thus,
the effect of resonance sharpening justifies the usage of the sigma-like
field-theoretical models for the strongly interacting matter equation of state
at such temperatures. Also we argue that the most optimistic hope to find the
quark gluon bags experimentally may be related to their sharpening and
enhancement in a thermal medium. In this case the wide quark gluon bags may
appear directly or in decays as narrow resonances that are absent in the tables
of elementary particles and that have the width about 50-150 MeV and the mass
about or above 2.5 GeV.",1212.0132v1
2012-12-13,Quantum information processing using quasiclassical electromagnetic interactions between qubits and electrical resonators,"Electrical resonators are widely used in quantum information processing, by
engineering an electromagnetic interaction with qubits based on real or virtual
exchange of microwave photons. This interaction relies on strong coupling
between the qubits' transition dipole moments and the vacuum fluctuations of
the resonator in the same manner as cavity QED, and has consequently come to be
called ""circuit QED"" (cQED). Great strides in the control of quantum
information have already been made experimentally using this idea. However, the
central role played by photon exchange induced by quantum fluctuations in cQED
does result in some characteristic limitations. In this paper, we discuss an
alternative method for coupling qubits electromagnetically via a resonator, in
which no photons are exchanged, and where the resonator need not have strong
quantum fluctuations. Instead, the interaction can be viewed in terms of
classical, effective ""forces"" exerted by the qubits on the resonator, and the
resulting resonator dynamics used to produce qubit entanglement are purely
classical in nature. We show how this type of interaction is similar to that
encountered in the manipulation of atomic ion qubits, and we exploit this
analogy to construct two-qubit entangling operations that are largely
insensitive to thermal or other noise in the resonator, and to its quality
factor. These operations are also extensible to larger numbers of qubits,
allowing interactions to be selectively generated among any desired subset of
those coupled to a single resonator. Our proposal is potentially applicable to
a variety of physical qubit modalities, including superconducting and
semiconducting solid-state qubits, trapped molecular ions, and possibly even
electron spins in solids.",1212.3300v4
2012-12-25,"Alpha-resonance structure in $^{11}$C studied via resonant scattering of $^{7}$Be+$α$ and $^{7}$Be($α$, $p$) reaction","The resonance structure in $^{11}$C is particularly of interest with regard
to the astrophysical $^{7}$Be($\alpha$, $\gamma$) reaction, relevant at high
temperature, and to the $\alpha$-cluster structure in $^{11}$C. The measurement
was to determine unknown resonance parameters for the high excited states of
$^{11}$C. In particular, the $\alpha$ decay width can be useful information to
discuss $\alpha$ cluster structure in $^{11}$C. New measurements of the
$^{7}$Be+$\alpha$ resonant scattering and the $^{7}$Be($\alpha$, $p$)$^{10}$B
reaction in inverse kinematics were performed for center-of-mass energy up to
5.5 MeV, and the resonances at excitation energies of 8.9--12.7 MeV in the
compound $^{11}$C nucleus were studied. Inelastic scattering of
$^{7}$Be+$\alpha$ and the $^{7}$Be($\alpha$, $p_1$)$^{10}$B$^*$ reaction were
also studied with a simultaneous $\gamma$-ray measurement. The measurements
were performed at the low-energy RI beam facility CRIB (CNS Radioactive Ion
Beam separator) of the Center for Nuclear Study (CNS), the University of Tokyo.
We obtained excitation functions of $^{7}$Be($\alpha$, $\alpha_0$)$^{7}$Be
(elastic scattering), $^{7}$Be($\alpha$, $\alpha_1$)$^{7}$Be$^*$ (inelastic
scattering), $^{7}$Be($\alpha$, $p_0$)$^{10}$B, and $^{7}$Be($\alpha$,
$p_1$)$^{10}$B$^*$. Many resonances including a new one were observed and their
parameters were determined by an R-matrix analysis. The resonances we observed
possibly enhance the $^{7}$Be($\alpha$, $\gamma$) reaction rate but in a
smaller magnitude than the lower-lying resonances. A new negative-parity
cluster band, similar to the one previously suggested in the mirror nucleus
$^{11}$B, is proposed.",1212.5991v1
2013-07-06,A new scenario for the origin of the 3/2 resonant system HD45364,"In this paper we revise the model proposed by Rein et al. (2010) for the
origin of the HD45364 exoplanetary system, currently known to host two planets
close to the 3/2 mean-motion commensurability (MMR). We show that, due to high
surface density of the protoplanetary disk needed for Type III migration, this
model could only lead to planets in a quasi-resonant regime of motion, and thus
not consistent with the resonant configuration obtained by Correia et al.
(2009). Although both resonant and quasi-resonant solutions are statistically
indistinguishable with respect to radial velocity measurements, their distinct
dynamical behaviour is intriguing. We use the semi-analytical model to confirm
the quantitative difference between two configurations. In order to form a
system evolving inside the 3/2 resonance, we develop a different model. Our
scenario includes an interaction between different (but slower) planetary
migration types, planet growth, and gap formation in the protoplanetary disk.
The choice of the described evolutionary path was due to a detailed analysis of
the structure of the phase space in the vicinity of the 3/2 MMR employing
dynamical mapping techniques. The outcomes of our simulations are able to
reproduce very closely the 3/2 resonant dynamics obtained from the best-fit
presented by Correia et al. (2009). In addition, varying the strength of the
eccentricity damping, we can also simulate the quasi-resonant configuration
similar to that in Rein et al. (2010). We furthermore show that our scenario is
robust with respect to the physical parameters involved in the resonance
trapping process. However, the confirmation of our scenario will be possible
only with additional radial velocities measurements.",1307.1822v4
2013-07-09,Density functional studies on the hollow resonances in Li-isoelectronic sequence (Z=4--10,"In this sequel to our work on triply excited hollow resonances in
three-electron atomic systems, a density functional theory (DFT)-based
formalism is employed to investigate similar resonances in Li-isoelectronic
series (Z=4--10). A combination of the work-function-based local nonvariational
exchange potential and the popular gradient plus Laplacian included
Lee-Yang-Parr correlation energy functional is used. First, all the 8 n=2
intrashell states of B$^{2+}$, N$^{4+}$ and F$^{6+}$ are presented, which are
relatively less studied in the literature compared to the remaining 4 members.
Then calculations are performed for the 8 $2l2l'$n$l""$ (3$\leq$n$\leq$6) hollow
resonance series; {\em viz.,} 2s$^2$ns $^2$S$^e$, 2s$^2$np $^2$P$^o$, 2s$^2$nd
$^2$D$^e$, 2s2pns $^4$P$^o$, 2s2pnp $^4$D$^e$, 2p$^2$ns $^4$P$^e$, 2p$^2$np
$^4$D$^o$ and 2p$^2$ns $^2$D$^e$, of all the 7 positive ions. Next, as an
illustration, higher resonance positions of the 2s$^2$ns $^2$S$^e$ series are
calculated for all the ions with a maximum of n=25. The excitation energies
calculated from this single-determinantal approach are in excellent agreement
with the available literature data (for the n=2 intrashell states the deviation
is within 0.125% and excepting only one case, the same for the resonance series
is well below 0.50%). With an increase in Z, the deviations tend to decrease.
Radial densities are also presented for some of the selected states. The only
result available in the literature for the lower resonances (corresponding to a
maximum of n=17) have been reported very recently. The n$>$16 ($>17$ for
F$^{6+}$) resonances are examined here for the first time. This gives a
promising viable and general DFT scheme for the accurate calculation of these
and other hollow resonances in many-electron atoms.",1307.2336v1
2015-06-30,Linearized averaged resonant equations and their solution for dust particles,"The averaged resonant equations of motion for the planar circular restricted
three-body problem are solved on the linearization basis taking into account
also non-gravitational effects. The averaged resonant equations are derived
from Lagrange's planetary equations with additional Gauss's terms caused by the
non-gravitational effects. The time depending solution has the standard form
with exponential, quadratic, linear and constant terms. The existence of a
rotational symmetry in the action of the non-gravitational effects around the
star determines the order of a characteristic equation of the linearized
system. In the symmetrical case (order 3) the considered non-gravitational
effects are the stellar electromagnetic radiation and the radial stellar wind
(stellar radiation). In the asymmetrical case (order 4) the stellar radiation
and interstellar gas flow are considered. It is investigated how well the
linearization solution describes real solution obtained from an equation of
motion by a comparison of the resonant libration frequency found analytically
and numerically. It is found that from initial values of the evolving orbital
parameters (semimajor axis, eccentricity, longitude of pericenter, and resonant
angular variable) in the averaged phase space the linearization frequency
depends most sensitively on the initial value of the resonant angular variable.
For small libration amplitudes of the resonant angular variable the best match
of the real libration frequency and the linearization frequency is located
approximately at the solution of the resonant condition ($da / dt$ $=$ 0). If
the initial averaged conditions are chosen close to the solution of resonant
condition, then the linearization frequency for practically all simple
oscillatory evolutions matches the real libration frequency and the
linearization solution very well approximates the real evolution.",1506.09033v6
2015-10-19,Quasi-bound states of massive scalar fields in the Kerr black-hole spacetime: Beyond the hydrogenic approximation,"Rotating black holes can support quasi-stationary (unstable) bound-state
resonances of massive scalar fields in their exterior regions. These spatially
regular scalar configurations are characterized by instability timescales which
are much longer than the timescale $M$ set by the geometric size (mass) of the
central black hole. It is well-known that, in the small-mass limit
$\alpha\equiv M\mu\ll1$ (here $\mu$ is the mass of the scalar field), these
quasi-stationary scalar resonances are characterized by the familiar hydrogenic
oscillation spectrum: $\omega_{\text{R}}/\mu=1-\alpha^2/2{\bar n}^2_0$, where
the integer $\bar n_0(l,n;\alpha\to0)=l+n+1$ is the principal quantum number of
the bound-state resonance (here the integers $l=1,2,3,...$ and $n=0,1,2,...$
are the spheroidal harmonic index and the resonance parameter of the field
mode, respectively). As it depends only on the principal resonance parameter
$\bar n_0$, this small-mass ($\alpha\ll1$) hydrogenic spectrum is obviously
degenerate. In this paper we go beyond the small-mass approximation and analyze
the quasi-stationary bound-state resonances of massive scalar fields in
rapidly-spinning Kerr black-hole spacetimes in the regime $\alpha=O(1)$. In
particular, we derive the non-hydrogenic (and, in general, non-degenerate)
resonance oscillation spectrum
${{\omega_{\text{R}}}/{\mu}}=\sqrt{1-(\alpha/{\bar n})^2}$, where $\bar
n(l,n;\alpha)=\sqrt{(l+1/2)^2-2m\alpha+2\alpha^2}+1/2+n$ is the generalized
principal quantum number of the quasi-stationary resonances. This analytically
derived formula for the characteristic oscillation frequencies of the composed
black-hole-massive-scalar-field system is shown to agree with direct numerical
computations of the quasi-stationary bound-state resonances.",1510.05649v1
2015-10-29,Period Ratio Distribution of Near-Resonant Planets Indicates Planetesimal Scattering,"An intriguing trend among Kepler's multi-planet systems is an overabundance
of planet pairs with period ratios just wide of mean motion resonances (MMR)
and a dearth of systems just narrow of them. In a recently published paper
Chatterjee & Ford (2015; henceforth CF15) has proposed that gas-disk migration
traps planets in a MMR. After gas dispersal, orbits of these trapped planets
are altered through interaction with a residual planetesimal disk. They found
that for massive enough disks planet-planetesimal disk interactions can break
resonances and naturally create moderate to large positive offsets from the
initial period ratio for large ranges of planetesimal disk and planet
properties. Divergence from resonance only happens if the mass of planetesimals
that interact with the planets is at least a few percent of the total planet
mass. This threshold, above which resonances are broken and the offset from
resonances can grow, naturally explains why the asymmetric large offsets were
not seen in more massive planet pairs found via past radial velocity surveys.
In this article we will highlight some of the key findings of CF15. In
addition, we report preliminary results from an extension of this study, that
investigates the effects of planet-planetesimal disk interactions on initially
non-resonant planet pairs. We find that planetesimal scattering typically
increases period ratios of non-resonant planets. If the initial period ratios
are below and in proximity of a resonance, under certain conditions, this
increment in period ratios can create a deficit of systems with period ratios
just below the exact integer corresponding to the MMR and an excess just above.
From an initially uniform distribution of period ratios just below a 2:1 MMR,
planetesimal interactions can create an asymmetric distribution across this MMR
similar to what is observed for the Kepler planet pairs.",1510.08933v2
2016-02-22,"Neptune's Orbital Migration Was Grainy, Not Smooth","The Kuiper belt is a population of icy bodies beyond the orbit of Neptune.
The complex orbital structure of the Kuiper belt, including several categories
of objects inside and outside of resonances with Neptune, emerged as a result
of Neptune's migration into an outer planetesimal disk. An outstanding problem
with the existing migration models is that they invariably predict excessively
large resonant populations, while observations show that the non-resonant
orbits are in fact common (e.g., the main belt population is 2-4 times larger
than Plutinos in the 3:2 resonance). Here we show that this problem can
resolved if it is assumed that Neptune's migration was grainy, as expected from
scattering encounters of Neptune with massive planetesimals. The grainy
migration acts to destabilize resonant bodies with large libration amplitudes,
a fraction of which ends up on stable non-resonant orbits. Thus, the
non-resonant--to--resonant ratio obtained with the grainy migration is higher,
up to ~10 times higher for the range of parameters investigated here, than in a
model with smooth migration. The grainy migration leads to a narrower
distribution of the libration amplitudes in the 3:2 resonance. The best fit to
observations is obtained when it is assumed that the outer planetesimal disk
below 30 AU contained 1000-4000 Plutos, or ~1000 bodies twice as massive as
Pluto. We find that the probability for an outer disk object to end up on a
stable orbit in the Kuiper belt is ~10^{-3}. Together, these results are
consistent with having only two (known) Pluto-mass bodies in the Kuiper belt
today (Pluto and Eris). The combined mass of Pluto-class objects in the
original disk was ~2-8 Earth masses (M_Earth), which represents 10-40% of the
estimated disk mass (M_disk ~ 20 M_Earth).",1602.06988v1
2016-06-07,Modeling quasi-dark states with Temporal Coupled-Mode Theory,"Coupled resonators are commonly used to achieve tailored spectral responses
and allow novel functionalities in a broad range of applications, from optical
modulation and filtering in integrated photonic circuits to the study of
nonlinear dynamics in arrays of resonators. The Temporal Coupled-Mode Theory
(TCMT) provides a simple and general tool that is widely used to model these
devices and has proved to yield very good results in many different systems of
low-loss, weakly coupled resonators. Relying on TCMT to model coupled
resonators might however be misleading in some circumstances due to the
lumped-element nature of the model. In this article, we report an important
limitation of TCMT related to the prediction of dark states. Studying a coupled
system composed of three microring resonators, we demonstrate that TCMT
predicts the existence of a dark state that is in disagreement with
experimental observations and with the more general results obtained with the
Transfer Matrix Method (TMM) and the Finite-Difference Time-Domain (FDTD)
simulations. We identify the limitation in the TCMT model to be related to the
mechanism of excitation/decay of the supermodes and we propose a correction
that effectively reconciles the model with expected results. A comparison with
TMM and FDTD allows to verify both steady-state and transient solutions of the
modified-TCMT model. The proposed correction is derived from general
considerations, energy conservation and the non-resonant power circulating in
the system, therefore it provides good insight on how the TCMT model should be
modified to eventually account for the same limitation in a different
coupled-resonator design. Moreover, our discussion based on coupled microring
resonators can be useful for other electromagnetic resonant systems due to the
generality and far-reach of the TCMT formalism.",1606.02339v1
2018-04-02,Asteroid families interacting with secular resonances,"Asteroid families are formed as the result of collisions. Large fragments are
ejected with speeds of the order of the escape velocity from the parent body.
After the family formation, the fragments' orbits evolve in the space of proper
elements because of gravitational and non-gravitational perturbations, such as
the Yarkovsky effect. Disentangling the contribution to the current orbital
position of family members caused by the initial ejection velocity field and
the subsequent orbital evolution is usually a difficult task. Among the more
than 100 asteroid families currently known, some interact with secular
resonances. Linear secular resonances occur when there is a commensurability
between the precession frequency of the longitude of the pericenter (g) or of
the longitude of node (s) of an asteroid and a planet, or a massive asteroid.
The linear secular resonance most effective in increasing an asteroid
eccentricity is the ${\nu}_6$, that corresponds to a commensurability between
the precession frequency g of an asteroid and Saturn's $g_6$. Non-linear
secular resonances involve commensurabilities of higher order, and can often be
expressed as combinations of linear secular resonances. This is the case, for
instance, of the $z_k=k(g-g_6)+(s-s_6)$ resonances. Asteroid families that are
crossed by secular resonances are of particular interest in dynamical
astronomy. First, they often provide a clear evidence of asteroid orbit
evolution due to the Yarkovsky effect. Second, conserved quantities of secular
dynamics can be used to set valuable constraints on the magnitude of the
original ejection velocity field. Finally, by changing the value of inclination
of family members nodal secular resonances with massive asteroids or dwarf
planets can cause the i distribution to become more and more leptokurtic (i.e.,
more peaked and with larger tails than that of a Gaussian distribution).",1804.00505v1
2015-12-24,Shedding Light on Diphoton Resonances,"The experimental and theoretical implications of heavy digauge boson
resonances that couple to, or are comprised of, new charged and strongly
interacting matter are investigated. Observation and measurement of ratios of
the resonant digauge boson channels $WW$, $ZZ$, $\gamma \gamma$, $Z \gamma$,
and $gg$ in the form of dijets, provide a rather direct -- and for some ratios
a rather robust -- probe of the gauge representations of the new matter. For a
spin-zero resonance with the quantum numbers of the vacuum, the ratios of
resonant $WW$ and $ZZ$ to $\gamma \gamma$ channels, as well as the longitudinal
versus transverse polarization fractions in the $WW$ and $ZZ$ channels, provide
probes for possible mixing with the Higgs boson, while di-Higgs and ditop
resonant channels, $hh$ and $tt$, provide somewhat less sensitivity. We present
a survey of possible underlying models for digauge boson resonances by
considering various limits for the mass of the new charged and strongly
interacting matter fields as well as the confinement scale of new hypergauge
interactions under which they may also be charged. In these limits, resonances
may be included as elementary weakly coupled spin-zero states or can correspond
to hyperglueballs, hyperonia, or pseudoscalar hypermesons. For each of these
cases, we make predictions for additional states that could be resonantly or
pair produced and observed at the Large Hadron Collider or in future collider
experiments. Heavy digauge boson resonances can provide a unified explanation
for a number of small discrepancies and excesses in reported data from the
Large Hadron Collider.",1512.07733v3
2016-05-13,Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy,"Planar superconducting microwave resonators are key elements in a variety of
technical applications and also act as sensitive probes for microwave
spectroscopy of various materials of interest. Here superconducting Pb is a
suitable material as a basis for microwave stripline resonators.
  To utilize Pb stripline resonators in a variable magnetic field (e.g. in
ESR), the electrodynamics of such resonators in finite magnetic field has to be
well understood. Therefore we performed microwave transmission measurements on
superconducting Pb stripline resonators in a variable, parallel magnetic field.
We determined surface resistance, penetration depth as well as real and
imaginary parts, \sigma$_1$ and \sigma$_2$, of the complex conductivity of
superconducting Pb as a function of magnetic field. Here we find features
reminiscent of those in temperature-dependent measurements, such as a maximum
in \sigma$_1$ (coherence peak). At magnetic fields above the critical field of
this type-I superconductor we still find low-loss microwave response, which we
assign to remaining superconductivity in the form of filaments within the Pb.
Hysteresis effects are found in the quality factor of resonances once the swept
magnetic field has exceeded the critical magnetic field. This is due to normal
conducting areas that are pinned and can therefore persist in the
superconducting phase. Besides zero-field-cooling we show an alternative way to
eliminate these even at T<T$_c$. Based on our microwave data, we determine the
critical magnetic field and the critical temperature of Pb in a temperature
range between 1.6K and 6.5K and magnetic fields up to 140mT, showing good
agreement with BCS predictions. We study a Sn sample in a Pb resonator to
demonstrate the applicability of superconducting Pb stripline resonators in the
experimental study of other (super-)conducting materials in a variable magnetic
field.",1605.04273v2
2016-08-31,Modelling resonances and orbital chaos in disk galaxies. Application to a Milky Way spiral model,"Context: Resonances in the stellar orbital motion under perturbations from
spiral arms structure play an important role in the evolution of the disks of
spiral galaxies. The epicyclic approximation allows the determination of the
corresponding resonant radii on the equatorial plane (for nearly circular
orbits), but is not suitable in general.
  Aims: We expand the study of resonant orbits by analysing stellar motions
perturbed by spiral arms with Gaussian-shaped profiles without any restriction
on the stellar orbital configurations, and we expand the concept of Lindblad
(epicyclic) resonances for orbits with large radial excursions.
  Methods: We define a representative plane of initial conditions, which covers
the whole phase space of the system. Dynamical maps on representative planes
are constructed numerically, in order to characterize the phase-space structure
and identify the precise location of resonances. The study is complemented by
the construction of dynamical power spectra, which provide the identification
of fundamental oscillatory patterns in the stellar motion.
  Results: Our approach allows a precise description of the resonance chains in
the whole phase space, giving a broader view of the dynamics of the system when
compared to the classical epicyclic approach, even for objects in retrograde
motion. The analysis of the solar neighbourhood shows that, depending on the
current azimuthal phase of the Sun with respect to the spiral arms, a star with
solar kinematic parameters may evolve either inside the stable co-rotation
resonance or in a chaotic zone.
  Conclusions: Our approach contributes to quantifying the domains of resonant
orbits and the degree of chaos in the whole Galactic phase-space structure. It
may serve as a starting point to apply these techniques to the investigation of
clumps in the distribution of stars in the Galaxy, such as kinematic moving
groups.",1608.08991v2
2018-10-03,"Direct capture cross section and the $E_p$ = 71 and 105 keV resonances in the $^{22}$Ne($p,γ$)$^{23}$Na reaction","The $^{22}$Ne($p,\gamma$)$^{23}$Na reaction, part of the neon-sodium cycle of
hydrogen burning, may explain the observed anticorrelation between sodium and
oxygen abundances in globular cluster stars. Its rate is controlled by a number
of low-energy resonances and a slowly varying non-resonant component. Three new
resonances at $E_p$ = 156.2, 189.5, and 259.7 keV have recently been observed
and confirmed. However, significant uncertainty on the reaction rate remains
due to the non-resonant process and to two suggested resonances at $E_p$ = 71
and 105 keV. Here, new $^{22}$Ne($p,\gamma$)$^{23}$Na data with high statistics
and low background are reported. Stringent upper limits of 6$\times$10$^{-11}$
and 7$\times$10$^{-11}$\,eV (90\% confidence level), respectively, are placed
on the two suggested resonances. In addition, the off-resonant S-factor has
been measured at unprecedented low energy, constraining the contributions from
a subthreshold resonance and the direct capture process. As a result, at a
temperature of 0.1 GK the error bar of the $^{22}$Ne($p,\gamma$)$^{23}$Na rate
is now reduced by three orders of magnitude.",1810.01628v1
2019-06-16,Confronting theoretical results of localized and additional surface plasmon resonances in silver nanoparticles with EELS measurements,"Raza et al. recently observed the extraordinarily large energy blueshifts of
localized surface plasmon resonances and additional surface plasmon resonances
in silver nanoparticles encapsulated in silicon nitride, which are not fully
understood yet. By using the quantum model consisting of two subsystems
respectively for describing the center of mass and intrinsic motions of
conduction electrons of a metallic nanosphere and a coupling occurred between
the center of mass and conduction electrons outside the metallic nanosphere, we
firstly deduced the general energy and line broadening size-dependence of
localized surface plasmon resonances, which removes the divergent defect of
usual 1/R size-dependence. Secondly, we proposed that the additional surface
plasmon resonance in a metallic nanosphere originates from the transition of
the first excited state to the ground state of the center of mass subsystem
with energy levels corrected by degenerate state pairs of the system composed
of the center of mass and intrinsic motions of conduction electrons. Then, we
implemented this generation mechanism of additional surface plasmon resonances
for silver nanoparticles encapsulated in silicon nitride and the calculated
results are well consistent with experimental results. Furthermore, we obtained
a new energy expression of localized surface plasmon resonances, with which we
successfully explained the extraordinarily large energy blueshifts of localized
surface plasmon resonances in few-nanometer silver nanoparticles encapsulated
in silicon nitride. Finally, we calculated the localized and additional surface
plasmon resonance energies of silver nanoparticles resting on carbon films and
the calculated results perfectly explain the experimental measurements of
Scholl et al..",1906.06700v5
2019-07-27,Dynamical vector resonances from the EChL in VBS at the LHC: the WW case,"In this work we study the phenomenology of the process $pp\to W^+W^-jj$ at
the LHC, in the scenario of the resonant vector boson scattering subprocess
$W^+W^-\to W^+W^-$ which we describe within the effective field theory
framework of the Electroweak Chiral Lagrangian. We assume a strongly
interacting electroweak symmetry breaking sector in which dynamically generated
resonances with masses in the TeV scale appear as poles in the Electroweak
Chiral Lagrangian amplitudes unitarized with the Inverse Amplitude Method. The
relevant resonance here, $V_0$, is the neutral component of the triplet of
vector resonances which are known to emerge dynamically at the TeV scale for
specific values of the Electroweak Chiral Lagrangian parameters. With the aim
of studying the production and possible observation of $V^0$ at the LHC, via
the resonant $W^+W^-\to W^+W^-$ scattering, a MadGraph~5 UFO model has been
developed employing a phenomenological Proca Lagrangian as a practical tool to
mimic the correct $V^0$ properties that are predicted with the Inverse
Amplitude Method. We choose to study the fully hadronic decay channel of the
final gauge bosons $W W\to J(jj)J(jj)$ since it leads to larger event rates and
because in the alternative leptonic decay channels the presence of neutrinos
complicates the reconstruction of the resonance properties. In this context,
the 2 boosted jets from the $W$ hadronic decays, $jj$, are detected as a single
fat jet, $J$, due to their extreme collinearity. We perform a dedicated
analysis of the sensitivity to these vector resonances $V^0$ with masses
between 1.5 and 2.5 TeV at the LHC with $\sqrt{s}=13$ TeV and the planned high
luminosity of 3000 ${\rm fb}^{-1}$, paying special attention to the study of
efficient cuts to extract the resonant vector boson fusion signal from the QCD
background, which clearly represents the main challenge of this search.",1907.11957v2
2018-12-10,The signatures of the resonances of a large Galactic bar in local velocity space,"The second data release of the Gaia mission has revealed a very rich
structure in local velocity space. In terms of in-plane motions, this rich
structure is also seen as multiple ridges in the actions of the axisymmetric
background potential of the Galaxy. These ridges are probably related to a
combination of effects from ongoing phase-mixing and resonances from the spiral
arms and the bar. We have recently developed a method to capture the behaviour
of the stellar phase-space distribution function at a resonance, by
re-expressing it in terms of a new set of canonical actions and angles
variables valid in the resonant region. Here, by properly treating the
distribution function at resonances, and by using a realistic model for a
slowly rotating large Galactic bar with pattern speed 39 km/s/kpc, we show that
no less than six ridges in local action space can be related to resonances with
the bar. Two of these at low angular momentum correspond to the corotation
resonance, and can be associated to the Hercules moving group in local velocity
space. Another one at high angular momentum corresponds to the outer Lindblad
resonance, and can tentatively be associated to the velocity structure seen as
an arch at high azimuthal velocities in Gaia data. The other ridges are
associated to the 3:1, 4:1 and 6:1 resonances. The latter can be associated to
the so-called 'horn' of the local velocity distribution. While it is clear that
effects from spiral arms and incomplete phase-mixing related to external
perturbations also play a role in shaping the complex kinematics revealed by
Gaia data, the present work demonstrates that, contrary to common
misconceptions, the bar alone can create multiple prominent ridges in velocity
and action space.",1812.04151v4
2019-11-22,A Laterally Vibrating Lithium Niobate MEMS Resonator Array Operating at 500°C in Air,"This paper is the first report of the high-temperature characteristics of a
laterally vibrating piezoelectric lithium niobate (LiNbO$_{3}$) MEMS resonator
array up to 500{\deg}C in air. After a high-temperature burn-in treatment,
device quality factor (Q) is enhanced to 508 and the resonance shifts to a
lower frequency and remains stable up to 500{\deg}C. During subsequent in situ
high-temperature testing, the resonant frequencies of two coupled shear
horizontal (SH0) modes in the array are 87.36 MHz and 87.21 MHz at 25{\deg}C
and 84.56 MHz and 84.39 MHz at 500{\deg}C, correspondingly, representing a -3%
shift in frequency over the temperature range. Upon cooling to room
temperature, the resonant frequency returns to 87.36 MHz, demonstrating
recoverability of device performance. The first- and second-order temperature
coefficient of frequency (TCF) are found to be -95.27 ppm/{\deg}C and 57.5
ppb/{\deg}C$^{2}$ for resonant mode A, and -95.43 ppm/{\deg}C and 55.8
ppb/{\deg}C$^{2}$ for resonant mode B, respectively. The temperature-dependent
quality factor (Q) and electromechanical coupling coefficient ($k_{t}^{2}$) are
extracted and reported. Device Q decreases to 334 after high-temperature
exposure, while $k_{t}^{2}$ increases to 12.40%. This work supports the use of
piezoelectric LiNbO$_{3}$ as a material platform for harsh environment
radio-frequency (RF) resonant sensors (e.g. temperature and infrared).",1911.10276v3
2019-12-09,Resonance sweeping by a decelerating Galactic bar,"We provide the first quantitative evidence for the deceleration of the
Galactic bar from local stellar kinematics in agreement with dynamical friction
by a typical dark matter halo. The kinematic response of the stellar disk to a
decelerating bar is studied using secular perturbation theory and test particle
simulations. We show that the velocity distribution at any point in the disk
affected by a naturally slowing bar is qualitatively different from that
perturbed by a steadily rotating bar with the same current pattern speed
$\Omega_{\rm p}$ and amplitude. When the bar slows down, its resonances sweep
through phase space, trapping and dragging along a portion of previously free
orbits. This enhances occupation on resonances, but also changes the
distribution of stars within the resonance. Due to the accumulation of orbits
near the boundary of the resonance, the decelerating bar model reproduces with
its corotation resonance the offset and strength of the Hercules stream in the
local $v_R$-$v_\varphi$ plane and the double-peaked structure of mean $v_R$ in
the $L_z$-$\varphi$ plane. At resonances other than the corotation, resonant
dragging by a slowing bar is associated with a continuing increase in radial
action, leading to multiple resonance ridges in the action plane as identified
in the Gaia data. This work shows models using a constant bar pattern speed
likely lead to qualitatively wrong conclusions. Most importantly we provide a
quantitative estimate of the current slowing rate of the bar $d\Omega_{\rm
p}/dt = (-4.5 \pm 1.4)~{\rm km} {\rm s}^{-1} {\rm kpc}^{-1} {\rm Gyr}^{-1}$
with additional systematic uncertainty arising from unmodeled impacts of e.g.
spiral arms.",1912.04304v2
2020-09-16,422 Million Q Planar Integrated All-Waveguide Resonator with a 3.4 Billion Absorption Limited Q and Sub-MHz Linewidth,"High Q optical resonators are a key component for ultra-narrow linewidth
lasers, frequency stabilization, precision spectroscopy and quantum
applications. Integration of these resonators in a photonic waveguide
wafer-scale platform is key to reducing their cost, size and power as well as
sensitivity to environmental disturbances. However, to date, the intrinsic Q of
integrated all-waveguide resonators has been relegated to below 150 Million.
Here, we report an all-waveguide Si3N4 resonator with an intrinsic Q of 422
Million and a 3.4 Billion absorption loss limited Q. The resonator has a 453
kHz intrinsic linewidth and 906 kHz loaded linewidth, with a finesse of 3005.
The corresponding linear loss of 0.060 dB/m is the lowest reported to date for
an all-waveguide design with deposited upper cladding oxide. These are the
highest intrinsic and absorption loss limited Q factors and lowest linewidth
reported to date for a photonic integrated all-waveguide resonator. This level
of performance is achieved through a careful reduction of scattering and
absorption loss components. We quantify, simulate and measure the various loss
contributions including scattering and absorption including surface-state
dangling bonds that we believe are responsible in part for absorption. In
addition to the ultra-high Q and narrow linewidth, the resonator has a large
optical mode area and volume, both critical for ultra-low laser linewidths and
ultra-stable, ultra-low frequency noise reference cavities. These results
demonstrate the performance of bulk optic and etched resonators can be realized
in a photonic integrated solution, paving the way towards photonic integration
compatible Billion Q cavities for precision scientific systems and applications
such as nonlinear optics, atomic clocks, quantum photonics and high-capacity
fiber communications systems on-chip.",2009.07428v1
2021-05-03,Stability of Neptune's distant resonances in the presence of Planet Nine,"Trans-Neptunian Objects (TNOs) in the scattered disk with 50 < a < 100 au are
thought to cluster near Neptune's n:1 resonances (e.g: 3:1, 4:1, and so on).
While these objects spend lengthy periods of time at large heliocentric
distances, if their perihelia remain less than around 40 au, their dynamical
evolution is still largely coupled to Neptune's. Conversely, around a dozen
extreme TNOs with a > 250 au and detached perihelia seem to exist in a regime
where they are too distant to be affected by the giant planets, and too close
for their dynamics to be governed by external forces. Recent work suggests that
the apparent alignment of these orbits in physical space is a signature of
gravitational shepherding by a distant massive planet. In this paper, we
investigate the evolution of TNOs in each of Neptune's n:1 resonances between
the 3:1 and 14:1. We conclude that both resonant and non-resonant objects
beyond the 12:1 near ~157 au are removed rather efficiently via perturbations
from the hypothetical Planet Nine. Additionally, we uncover a population of
simulated TNOs with a < 100 au, 40 < q < 45 au and low inclinations that
experience episodes of resonant interactions with both Neptune and Planet Nine.
Finally, we simulate the evolution of observed objects with a > 100 au and
identify several TNOs that are potentially locked in n:1 resonances with
Neptune; including the most distant known resonant candidates 2014 JW80 and
2014 OS394 that appear to be in the 10:1 and 11:1 resonances, respectively. Our
results suggest that the detection of similar remote objects might provide a
useful constraint on hypotheses invoking the existence of additional distant
planets.",2105.01065v2
2021-07-30,"A deep dive into the $2g+h$ resonance: separatrices, manifolds and phase space structure of navigation satellites","Despite extended past studies, several questions regarding the resonant
structure of the medium-Earth orbit (MEO) region remain hitherto unanswered.
This work describes in depth the effects of the $2g+h$ lunisolar resonance. In
particular, (i) we compute the correct forms of the separatrices of the
resonance in the inclination-eccentricity space for fixed semi-major axis. This
allows to compute the change in the width of the $2g+h$ resonance as the
altitude increases. (ii) We discuss the crucial role played by the value of the
inclination of the Laplace plane, $i_{L}$. Since $i_L$ is comparable to the
resonance's separatrix width, the parametrization of all resonance bifurcations
has to be done in terms of the proper inclination $i_{p}$, instead of the mean
one. (iii) The subset of circular orbits constitutes an invariant subspace
embedded in the full phase space, the center manifold $\mathcal{C}$. Using
$i_p$ as a label, we compute its range of values for which $\mathcal{C}$
becomes a normally hyperbolic invariant manifold (NHIM). The structure of
invariant tori in $\mathcal{C}$ allows to explain the role of the initial phase
$h$ noticed in several works. (iv) Through Fast Lyapunov Indicator (FLI)
cartography, we portray the stable and unstable manifolds of the NHIM as the
altitude increases. Manifold oscillations dominate in phase space between
$a=24,000$ km and $a=30,000$ km as a result of the sweeping of the $2g+h$
resonance by the $h-\Omega_{\rm{Moon}}$ and $2h-\Omega_{\rm{Moon}}$ resonances.
The noticeable effects of the latter are explained as a consequence of the
relative inclination of the Moon's orbit with respect to the ecliptic. The role
of the phases $(h,\Omega_{\rm{Moon}})$ in the structures observed in the FLI
maps is also clarified. Finally,(v) we discuss how the understanding of the
manifold dynamics could inspire end-of-life disposal strategies.",2107.14507v1
2022-03-29,Identifying the population of stable $ν_6$ resonant asteroids using large databases,"Large observational surveys, like those that will be conducted at the Vera C.
Rubin Observatory, are expected to discover up to one million new asteroids in
the first year of operation. This will more than double the database of known
asteroids. New methods and techniques will be needed to handle the large influx
of data. Here, we tested some of these new methods by studying the population
of asteroids on stable orbits inside the ${\nu}_6$ secular resonance. This
resonance is one of the strongest mechanisms for destabilizing the orbits of
main-belt bodies and producing Near-Earth Asteroids (NEAs). Yet, stable orbital
configurations where the asteroid pericenter is either aligned or anti-aligned
with that of Saturn exist inside the resonance. The population of stable
${\nu}_6$ resonators is now the largest population of asteroids in stable
orbits inside a secular resonance. Here we obtained the largest sample of
asteroids' proper elements ever used for this problem. Clustering methods and
the use of machine learning algorithms permitted the identification of the
known asteroid families crossed by the ${\nu}_6$ resonance and of two entirely
new groups: the Tiffanykapler and the 138605 QW177 families. The Tiffanykapler
family is the first young asteroid family ever found in a linear secular
resonance, with an age of $3.0\pm1.2$ Myr and an ejection velocity field
parameter of $V_{EJ} = 15^{+6}_{-3}$ m/s. We identify a population of
high-eccentricity objects around the Tina family that may be the first example
of an asteroid family ""resonant halo"".",2203.15763v3
2022-04-12,Eccentric Mergers of Intermediate-Mass Black Holes from Evection Resonances in AGN Disks,"We apply the theory of nonlinear resonance capture to the problem of a black
hole binary (BHB) orbiting a supermassive black hole (SMBH) while embedded in
the accretion disk of an active galactic nucleus (AGN). If successful,
resonance capture can trigger dramatic growth in the BHB eccentricity, with
important consequences for the BHB merger timescale, as well as for the
gravitational wave (GW) signature of such an eccentric merger. This resonance
capture may occur when the orbital period around the SMBH (the ""outer binary"")
and the apsidal precession of the BHB (the ""inner binary"") are in a 1:1
commensurability. This effect is analogous to the phenomenon of lunar evection
resonance in the early Sun-Earth-Moon system, with the distinction that in the
present case, the BHB apsidal precession is due to general relativity, rather
than rotationally-induced distortion. In contrast to the case of lunar
evection, however, the inner binary undergoes orbital decay driven by GW
emission, rather than orbital expansion driven by tidal dissipation. This
distinction fundamentally alters the three-body dynamics, forbidding resonance
capture, and limiting eccentricity growth. However, if the BHB migrates through
of a gaseous AGN disk, the change in the outer binary can counterbalance the
suppressing effect of BHB decay, permitting evection resonance capture and the
production of eccentric BHB mergers. We compute the likelihood of resonance
capture assuming an agnostic distribution of parameters for the three bodies
involved and for the properties of the AGN disk. We find that intermediate-mass
ratio BHBs (involving an intermediate-mass black hole and a stellar-mass black
hole) are the most likely to be captured into evection resonance and thus
undergo an eccentric merger. We also compute the GW signature of these mergers,
showing that they can enter the LISA band while eccentric.",2204.06002v1
2022-06-08,Col-OSSOS: The Distribution of Surface Classes in Neptune's Resonances,"The distribution of surface classes of resonant trans-Neptunian objects
(TNOs) provides constraints on the protoplanetesimal disk and giant planet
migration. To better understand the surfaces of TNOs, the Colours of the Outer
Solar System Origins Survey (Col-OSSOS) acquired multi-band photometry of 102
TNOs, and found that the surfaces of TNOs can be well described by two surface
classifications, BrightIR and FaintIR. These classifications both include
optically red members and are differentiated predominantly based on whether
their near-infrared spectral slope is similar to their optical spectral slope.
The vast majority of cold classical TNOs, with dynamically quiescent orbits,
have the FaintIR surface classification, and we infer that TNOs in other
dynamical classifications with FaintIR surfaces share a common origin with the
cold classical TNOs. Comparison between the resonant populations and the
possible parent populations of cold classical and dynamically excited TNOs
reveal that the 3:2 has minimal contributions from the FaintIR class, which
could be explained by the $\nu_8$ secular resonance clearing the region near
the 3:2 before any sweeping capture occurred. Conversely, the fraction of
FaintIR objects in the 4:3 resonance, 2:1 resonance, and the resonances within
the cold classical belt, suggest that the FaintIR surface formed in the
protoplanetary disk between 34.6 and 47 au, though the outer bound depends on
the degree of resonance sweeping during migration. The presence and absence of
the FaintIR surfaces in Neptune's resonances provides critical constraints for
the history of Neptune's migration, the evolution of the $\nu_8$, and the
surface class distribution in the initial planetesimal disk",2206.04083v2
2022-06-16,Electron spin resonance and collective excitations in magic-angle twisted bilayer graphene,"In a strongly correlated system, collective excitations contain key
information regarding the electronic order of the underlying ground state. An
abundance of collective modes in the spin and valley isospin channels of
magic-angle graphene moir\'e bands has been alluded to by a series of recent
experiments. However, direct observation of collective excitations has remained
elusive due to the lack of a spin probe. In this work, we use a
resistively-detected electron spin resonance technique to look for low-energy
collective excitations in magic-angle twisted bilayer graphene. We report
direct observation of collective modes in the form of microwave-induced
resonance near half filling of the moir\'e flatbands. The frequency-magnetic
field dependence of these resonance modes sheds light onto the nature of
intervalley spin coupling, allowing us to extract parameters such as
intervalley exchange interaction and spin stiffness. Two independent
observations testify that the generation and detection of the microwave
resonance relies on the strong correlation within the flat moir\'e energy band.
First, the onset of robust resonance response coincides with the spontaneous
flavor polarization at half moir\'e filling, and remains absent in the density
range where the underlying Fermi surface is isospin unpolarized. Second, we
performed the same resonance measurement on graphene monolayer and bilayer
samples, including twisted bilayer with a large twist angle, where flatband
physics is absent. We observe no indication of resonance response in these
samples across a large range of carrier density, microwave frequency and power.
A natural explanation is that the resonance response near the magic angle
originates from ""Dirac revivals"" and the resulting isospin order.",2206.08354v2
2022-11-29,"Towards clarifying the possibility of observation of the LHCb hidden-charm pentaquarks $P_{c}^+(4312)$, $P_{c}^+(4337)$, $P_{c}^+(4440)$ and $P_{c}^+(4457)$ in near-threshold charmonium photoproduction off protons and nuclei","We study the near-threshold $J/\psi$ meson photoproduction from protons and
nuclei by considering incoherent direct non-resonant (${\gamma}p \to
{J/\psi}p$, ${\gamma}n \to {J/\psi}n$) and two-step resonant (${\gamma}p \to
P_{ci}^+ \to {J/\psi}p$, ${\gamma}n \to P_{ci}^0 \to {J/\psi}n$, $i=1$, 2, 3,
4; $P_{c1}^{+,0}=P_c^{+,0}(4312)$, $P_{c2}^{+,0}=P_c^{+,0}(4337)$,
$P_{c3}^{+,0}=P_c^{+,0}(4440)$, $P_{c4}^{+,0}=P_c^{+,0}(4457)$) charmonium
production processes. We calculate the absolute excitation functions, energy
and momentum distributions for the non-resonant, resonant and for the combined
(non-resonant plus resonant) production of $J/\psi$ mesons on protons as well
as, using the nuclear spectral function approach, on carbon and tungsten target
nuclei at near-threshold incident photon energies by assuming the spin-parity
assignments of the hidden-charm resonances $P_{c}^{+,0}(4312)$,
$P_{c}^{+,0}(4337)$, $P_{c}^{+,0}(4440)$ and $P_{c}^{+,0}(4457)$ as
$J^P=(1/2)^-$, $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within three
different realistic scenarios for the branching ratios of their decays to the
${J/\psi}p$ and ${J/\psi}n$ modes (0.25, 0.5 and 1%). We show that will be very
hard to measure the $P_{ci}^+$ pentaquark states through the scan of the
$J/\psi$ total photoproduction cross section on a proton target in the
near-threshold energy region around the resonant photon energies of 9.44,
9.554, 10.04 and 10.12 GeV if these branching ratios $\sim$ 1% and less. We
also demonstrate that at these photon beam energies the $J/\psi$ energy and
momentum combined distributions considered reveal distinct sensitivity to the
above scenarios, respectively, at ""low"" $J/\psi$ total energies and momenta,
which implies that they may be an important tool to provide further evidence
for the existence of the pentaquark $P_{ci}^+$ and $P_{ci}^0$ resonances.",2211.16037v1
2023-01-02,Theoretical investigation of the occurrence of tidally excited oscillations in massive eccentric binary systems,"Massive and intermediate-mass stars reside in binary systems much more
frequently than low-mass stars. Binaries containing massive main-sequence (MS)
component(s) are often characterised by eccentric orbits, and can be observed
as eccentric ellipsoidal variables (EEVs). The orbital phase-dependent tidal
potential acting on the components of EEV can induce tidally excited
oscillations (TEOs). We investigate how the history of resonances between the
eigenmode spectra of the EEV components and the tidal forcing frequencies
depends on the initial parameters of the system. We synthesised 20,000
evolutionary models of the EEVs across the MS. Later, we calculated the
eigenfrequencies for each model. We focused only on the $l=2$, $m=0,+2$ modes.
Knowing the temporal changes in the orbital parameters of simulated EEVs and
the changes of the eigenfrequency spectra for both components, we were able to
determine so-called `resonance curves', which describe the overall chance of a
resonance occurring. We analysed the resonance curves by constructing basic
statistics for them and analysing their morphology using machine learning
methods, including the Uniform Manifold Approximation and Projection tool. The
EEV resonance curves from our sample are characterised by striking diversity,
including the occurrence of exceptionally long resonances or the absence of
resonances for long evolutionary times. Both components may be subject to
increased resonance rates as they approach the TAMS. On average, we should
observe TEOs more frequently in EEVs containing massive components than
intermediate-mass ones. TEOs will be particularly well-pronounced for EEVs with
the component(s) close to the TAMS. Given the total number of resonances and
their rates, TEOs may play an important role in the transport of angular
momentum within massive and intermediate-mass stars (mainly near TAMS).",2301.00733v1
2023-07-16,Understanding the total width of the $3_{1}^{-}$ state in $\mathrm{^{12}C}$,"Recent measurements indicate that the previously established upper limit for
the $\gamma$-decay branch of the $3_{1}^{-}$ resonance in $^{12}\textrm{C}$ at
$E_{x} = 9.641(5)$ MeV may be incorrect. As a result, the $3_{1}^{-}$ resonance
has been suggested as a significant resonance for mediating the triple-$\alpha$
reaction at high temperatures above 2 GK. Accurate estimations of the
$3_{1}^{-}$ contribution to the triple-$\alpha$ reaction rate require accurate
knowledge of not only the radiative width, but also the total width. In
anticipation of future measurements to more accurately determine the
$\gamma$-decay branch of the $3_{1}^{-}$ resonance, the objective of this work
is to accurately determine the total width of the $3_{1}^{-}$ resonance. An
evaluation was performed on all previous results considered in the current
ENSDF average of 46(3) keV for the physical total width (FWHM) of the
$3_{1}^{-}$ resonance in $^{12}\textrm{C}$. Significant unaccounted-for
uncertainties and a misstated result were discovered in these previous results,
leading to an invalid ENSDF average. In this work, the new global
\textbf{R}-matrix analysis performed on direct-reaction data yields a formal
total width of $\Gamma(E_{r}) = 46(2)$ keV and an observed total width of
$\Gamma_{\textrm{obs}}(E_{r}) = 38(2)$ keV for the $3_{1}^{-}$ resonance. An
observed total width of $\Gamma_{\textrm{obs}}(E_{r}) = 38(2)$ keV is
recommended for the $3_{1}^{-}$ resonance in $\mathrm{^{12}C}$. This observed
total width should be employed for future evaluations of the observed total
radiative width for the $3_{1}^{-}$ resonance and its contribution to the
high-temperature triple-$\alpha$ reaction rate.",2307.07917v3
2023-09-15,Cutting corners to suppress high-order modes in Mie resonator arrays,"Mie resonators as lattice resonant metasurfaces have the capability to
produce structural colour. However, design criteria for these metasurfaces are
still being investigated. In this work, we numerically examine how the
two-dimensional nanostructure shape in a lattice array affects the colorimetric
response of the metasurface under linearly polarised light excitation. First,
the transformation from a square-shaped to rectangle-shaped nanostructure array
resulted in polarisation-sensitive metasurfaces with colorimetric outputs bound
along a line on the CIE 1931 2-degree Standard Observer colour space. The
bounds of the colorimetry line were tuneable to any desired chromatic range.
Second, the removal of the corners in square- or rectangle-shaped
nanostructures to create t-shaped nanostructure arrays displayed a dampening
effect on the high-order resonance. Finally, we analytically determined that
the colour saturation could increase when moving from rectangle-shaped to
t-shaped nanostructure arrays. From these results, we present two design
guidelines for lattice resonant metasurfaces: (1) Constructing the
nanostructure to support fundamental resonances at different wavelengths
enables two-colour-bound movement when excited by successive angles of linearly
polarised light; (2) Removing portions of the nanostructure that only support
high-order resonances dampens these modes while maintaining support for
fundamental resonances. These results present first-principles guidelines for
engineering nanoparticles in lattice resonant metasurfaces, offering a new
toolbox for polarised-light sensing and colorimetric applications.",2309.08578v1
2023-10-06,Probing the hidden-bottom pentaquark resonances in photonuclear bottomonium production near threshold: differential observables,"We study the near-threshold $\Upsilon(1S)$ meson photoproduction from protons
and nuclei by considering incoherent direct non-resonant (${\gamma}p \to
{\Upsilon(1S)}p$, ${\gamma}n \to {\Upsilon(1S)}n$) and two-step resonant
(${\gamma}p \to P^+_{bi} \to {\Upsilon(1S)}p$, ${\gamma}n \to P^0_{bi} \to
{\Upsilon(1S)}n$, $i=1$, 2, 3; $P^{+,0}_{b1}=P^{+,0}_{b}(11080)$,
$P^{+,0}_{b2}=P^{+,0}_{b}(11125)$, $P^{+,0}_{b3}=P^{+,0}_{b}(11130)$)
bottomonium production processes with the main goal of clarifying the
possibility to observe the non-strange hidden-bottom pentaquark states
$P^{+,0}_{bi}$ in this production via differential observables. We calculate
the absolute excitation functions, energy and momentum distributions for the
non-resonant, resonant and for the combined (non-resonant plus resonant)
production of $\Upsilon(1S)$ mesons on protons, on carbon and tungsten target
nuclei at near-threshold incident photon beam energies by assuming the
spin-parity assignments of the hypothetical hidden-bottom resonances
$P^{+,0}_{b}(11080)$, $P^{+,0}_{b}(11125)$ and $P^{+,0}_{b}(11130)$ as
$J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within four different realistic
choices for the branching ratios of their decays to the ${\Upsilon}(1S)p$ and
${\Upsilon}(1S)n$ modes (0.125, 0.25, 0.5 and 1\%) as well as for two options
for the background contribution. We demonstrate that the measurements of these
combined observables on proton and nuclear targets in the near-threshold energy
region in future experiments at the planned high-luminosity electron-ion
colliders EIC and EicC in the US and China should provide evidence for the
existence of the above hidden-bottom pentaquark resonances as well as clarify
their decay rates.",2310.04123v2
2023-11-04,Evidence for Low-Level Dynamical Excitation in Near-Resonant Exoplanet Systems,"The geometries of near-resonant planetary systems offer a relatively pristine
window into the initial conditions of exoplanet systems. Given that
near-resonant systems have likely experienced minimal dynamical disruptions,
the spin-orbit orientations of these systems inform the typical outcomes of
quiescent planet formation, as well as the primordial stellar obliquity
distribution. However, few measurements have been made to constrain the
spin-orbit orientations of near-resonant systems. We present a
Rossiter-McLaughlin measurement of the near-resonant warm Jupiter TOI-2202 b,
obtained using the Carnegie Planet Finder Spectrograph (PFS) on the 6.5m
Magellan Clay Telescope. This is the eighth result from the Stellar Obliquities
in Long-period Exoplanet Systems (SOLES) survey. We derive a sky-projected 2D
spin-orbit angle $\lambda=26^{+12}_{-15}$ $^{\circ}$ and a 3D spin-orbit angle
$\psi=31^{+13}_{-11}$ $^{\circ}$, finding that TOI-2202 b - the most massive
near-resonant exoplanet with a 3D spin-orbit constraint to date - likely
deviates from exact alignment with the host star's equator. Incorporating the
full census of spin-orbit measurements for near-resonant systems, we
demonstrate that the current set of near-resonant systems with period ratios
$P_2/P_1\lesssim4$ is generally consistent with a quiescent formation pathway,
with some room for low-level ($\lesssim20^{\circ}$) protoplanetary disk
misalignments or post-disk-dispersal spin-orbit excitation. Our result
constitutes the first population-wide analysis of spin-orbit geometries for
near-resonant planetary systems.",2311.02478v1
2023-12-04,Kepler-discovered Multiple-planet Systems Near Period Ratios Suggestive of Mean-motion Resonances Are Young,"Before the launch of the Kepler Space Telescope, models of low-mass planet
formation predicted that convergent Type I migration would often produce
systems of low-mass planets in low-order mean-motion resonances. Instead,
Kepler discovered that systems of small planets frequently have period ratios
larger than those associated with mean-motion resonances and rarely have period
ratios smaller than those associated with mean-motion resonances. Both
short-timescale processes related to the formation or early evolution of
planetary systems and long-timescale secular processes have been proposed as
explanations for these observations. Using a thin disk stellar population's
Galactic velocity dispersion as a relative age proxy, we find that
Kepler-discovered multiple-planet systems with at least one planet pair near a
period ratio suggestive of a second-order mean-motion resonance have a colder
Galactic velocity dispersion and are therefore younger than both
single-transiting and multiple-planet systems that lack planet pairs consistent
with mean-motion resonances. We argue that a non-tidal secular process with a
characteristic timescale no less than a few hundred Myr is responsible for
moving systems of low-mass planets away from second-order mean-motion
resonances. Among systems with at least one planet pair near a period ratio
suggestive of a first-order mean-motion resonance, only the population of
systems likely affected by tidal dissipation inside their innermost planets has
a small Galactic velocity dispersion and is therefore young. We predict that
period ratios suggestive of mean-motion resonances are more common in young
systems with 10 Myr $\lesssim \tau \lesssim 100$ Myr and become less common as
planetary systems age.",2312.02260v1
2024-03-22,Generation of narrow beams of super high-energy gamma quanta in the resonant inverse Compton-effect in the field of a strong x-ray wave,"The article presents a theoretical study of Oleinik resonances in the process
of scattering a gamma quantum by an ultrarelativistic electron in the field of
a strong electromagnetic wave. It is shown that under resonant conditions, the
scattering channels of the reaction effectively split into two first-order
processes according to a fine structure constant such as the external
field-stimulated Compton effect. And the annihilation channel of the reaction
effectively decays into direct and reverse the external field-stimulated
Breit-Wheeler processes. The significant dependence of the resonant energy of
final particles and resonant cross sections on the outgoing angles of the final
gamma quantum, the number of absorbed and emitted photons of the wave, as well
as the characteristic quantum parameters of the problem is shown. These quantum
parameters are determined by the ratio of the initial particle energies to the
characteristic energies of the Compton effect and the Breit-Wheeler process. An
unambiguous relationship between the outgoing angles of final electrons and
gamma quanta has been obtained, which qualitatively distinguishes the resonant
process from the non-resonant one. The cases when the energy of the initial
electrons significantly exceeds the energy of the initial gamma quanta have
been studied. The conditions under which the energy of high-energy initial
electrons is converted into the energy of final gamma quanta are obtained. At
the same time, the resonant differential cross-section of such a process
significantly (by several orders of magnitude) exceeds the corresponding
non-resonant cross-section. This theoretical study predicts a number of new
physical effects that may explain the high-energy fluxes of gamma quanta born
near neutron stars and magnetars.",2403.15519v1
1998-05-12,Resonant Thickening of Disks by Small Satellite Galaxies,"We study the vertical heating and thickening of galaxy disks due to accretion
of small satellites. Our simulations are restricted to axial symmetry, which
largely eliminates numerical evolution of the target galaxy but requires the
trajectory of the satellite to be along the symmetry axis of the target. We
find that direct heating of disk stars by the satellite is not important
because the satellite's gravitational perturbation has little power at
frequencies resonant with the vertical stellar orbits. The satellite does
little damage to the disk until its decaying orbit resonantly excites
large-scale disk bending waves. Bending waves can damp through dynamical
friction from the halo or internal wave-particle resonances; we find that
wave-particle resonances dominate the damping. The principal vertical heating
mechanism is therefore dissipation of bending waves at resonances with stellar
orbits in the disk. Energy can thus be deposited some distance from the point
of impact of the satellite. The net heating from a tightly bound satellite can
be substantial, but satellites that are tidally disrupted before they are able
to excite bending waves do not thicken the disk.",9805145v1
1998-12-05,Dynamical Friction and Resonance Trapping in Planetary Systems,"A restricted planar circular three-body system, consisting of the Sun and two
planets, is studied as a simple model for a planetary system. The mass of the
inner planet is considered to be larger and the system is assumed to be moving
in a uniform interplanetary medium with constant density. Numerical
integrations of this system indicate a resonance capture when the dynamical
friction of the interplanetary medium is taken into account. As a result of
this resonance trapping, the ratio of orbital periods of the two planets
becomes nearly commensurate and the eccentricity and semimajor axis of the
orbit of the outer planet and also its angular momentum and total energy become
constant. It appears from the numerical work that the resulting
commensurability and also the resonant values of the orbital elements of the
outer planet are essentially independent of the initial relative positions of
the two bodies. The results of numerical integrations of this system are
presented and the first-order partially averaged equations are studied in order
to elucidate the behavior of the system while captured in resonance.",9812106v1
1999-03-30,Resonant Orbits in Triaxial Galaxies,"Box orbits in triaxial potentials are generically thin, that is, they lie
close in phase space to a resonant orbit satisfying a relation of the form
l\omega_1 +m\omega_2+n\omega_3=0 between the three fundamental frequencies.
Resonant orbits are confined to a membrane; they play roughly the same role, in
three dimensions, that closed orbits play in two. Stable resonant orbits avoid
the center of the potential; orbits that are thick enough to pass near the
center are typically stochastic. Very near the center, where the gravitational
potential is dominated by the black hole, resonant orbits continue to exist,
including at least one family whose elongation is parallel to the long axes of
the triaxial figure.",9903452v2
2000-10-12,X-Ray Photoabsorption in KLL Resonances of O VI And Abundance Analysis,"It is shown that photoabsorption via autoionizing resonances may be
appreciable and used for abundance analysis. Analogous to spectral lines, the
`resonance oscillator strength' f_r may be defined and evaluated in terms of
the differential oscillator strength df/d(epsilon) that relates bound and
continuum absorption. X-ray photoabsorption in KLL (1s2s2p) resonances of O VI
is investigated using highly resolved relativistic photoionization cross
sections with fine structure. It is found that f_r is comparable to that for UV
dipole transition in O VI (2s - 2p) and the X-ray (1s^2 ^1S_0 - 1s2p ^1P^o_1)
transition in O VII. The dominant O VI(KLL) components lie at 22.05 and 21.87
Angstroms. These predicted absorption features should be detectable by the
Chandra X-Ray Observatory (CXO) and the X-Ray Multi-Mirror Mission (XMM). The
combined UV/X-ray spectra of O VI/O VII should yield valuable information on
the ionization structure and abundances in sources such as the `warm absorber'
region of active galactic nuclei and the hot intergalactic medium. Some general
implications of resonant photoabsorption are addressed.",0010255v2
2002-01-30,Influence of Resonances on Spectral Formation of X-Ray Lines in Fe XVII,"New theoretical results from large-scale relativistic close coupling
calculations reveal the precise effect of resonances in collisional excitation
of x-ray lines of Ne-like Fe XVII. Employing the Breit-Pauli R-matrix method
and a 89-level eigenfunction expansion including up to n = 4 levels shows
significant resonance enhancement of the collision strengths of forbidden and
intercombination transitions. The present results differ from all previous
calculations, heretofore without detailed resonance structures, and should help
resolve longstanding discrepancies. In particular, the present line ratios of
three benchmark diagnostic lines 3C, 3D, and 3E at 15.014, 15.265, and 15.456 A
respectively, are in excellent agreement with two independent measurements on
Electron-Beam-Ion-Traps [Laming et al, Astrophys. J, 545, L161 (2000) and Brown
et al, Astrophys. J, 502, 1015 (1998)]. The strong energy dependence due to
resonances in these and other cross sections is demonstrated for the first
time. It is of general importance and strongly manifests itself in x-ray plasma
diagnostics.",0201513v3
2002-03-11,Growth of a peanut shaped bulge via resonant trapping of stellar orbits in the vertical Inner Lindblad Resonances,"We present a simple resonant Hamiltonian model for the vertical response of a
stellar disk to the growth of a bar perturbation. As a bar perturbation grows
stars become trapped in vertical Inner Lindblad resonances and are lifted into
higher amplitude orbits. The vertical structure of a boxy and peanut shaped
bulge as a function of radius and azimuthal angle in the galaxy plane can be
predicted from the strength and speed of the bar perturbation and the
derivatives of the gravitational potential. This model predicts that stars on
the outer side of the resonance are lifted higher than stars on the inner side,
offering an explanation for the sharp outer edge of the boxy/peanut.",0203170v3
2002-03-19,Parametric epicyclic resonance in black hole disks: QPOs in micro-quasars,"Non-linear acoustic coupling of modes in accretion disks allows a parametric
resonance between epicyclic motions. In black hole disks, such a resonance
first occurs, and is strongest, when the radial and vertical epicyclic
frequencies are approximately in a 2:3 ratio, in agreement with the 300 and 450
Hz frequencies reported in GRO J1655-40 and the 184 and 276 Hz frequencies
reported in XTE J1550-564. The first overtone in the same resonance is in a 5:3
ratio with the fundamental, in agreement with the 69.2 and 41.5 Hz frequencies
reported in GRS 1915+105. The narrow width and the frequency stability of the
corresponding QPOs follow from general properties of parametric resonance.",0203314v2
2002-05-17,Migration of asteroids from the 3/1 and 5/2 resonances with Jupiter to the Earth,"The orbital evolution of asteroids from the 3:1 and 5:2 resonances with
Jupiter under the gravitational influence of planets was investigated both by
the Bulirsh-Stoer method and by a symplectic method. The probabilities of
collisions of asteroids with the terrestrial planets were calculated for
orbital elements obtained with a step of 500 yr. The ratio of asteroids from
the 3:1 resonance that were ejected into hyperbolic orbits to those collided
the Sun was by an order of magnitude larger for direct integrations than for a
symplectic method. The probability of a collision of an asteroid with the Earth
for the 3:1 resonance was by a factor of 4 larger than that for the 5:2
resonance. The ratio of the probability of a collision of a body with a planet
to the mass of the planet for Mars was by a factor of 2 larger than that for
Earth and Venus.",0205309v1
2003-01-17,Stable 1:2 Resonant Periodic Orbits in Elliptic Three-Body Systems,"The results of an extensive numerical study of the periodic orbits of planar,
elliptic restricted three-body planetary systems consisting of a star, an inner
massive planet and an outer mass-less body in the external 1:2 mean-motion
resonance are presented. Using the method of differential continuation, the
locations of the resonant periodic orbits of such systems are identified and
through an extensive study of their phase-parameter space, it is found that the
majority of the resonant periodic orbits are unstable. For certain values of
the mass and the orbital eccentricity of the inner planet, however, stable
periodic orbits can be found. The applicability of such studies to the 1:2
resonance of the extrasolar planetary system GJ876 is also discussed.",0301363v1
2003-01-31,Could the 55 Cancri Planetary System Really Be in the 3:1 Mean Motion Resonance?,"We integrate the orbital solutions of the planets orbiting 55 Cnc. In the
simulations, we find that not only three resonant arguments
$\theta_{1}=\lambda_{1}-3\lambda_{2}+2\tilde\omega_{1}$,
$\theta_{2}=\lambda_{1}-3\lambda_{2}+2\tilde\omega_{2}$ and
$\theta_{3}=\lambda_{1}-3\lambda_{2}+(\tilde\omega_{1}+\tilde\omega_{2})$
librate respectively, but the relative apsidal longitudes $\Delta\omega$ also
librates about $250^{\circ}$ for millions of years. The results imply the
existence of the 3:1 resonance and the apsidal resonance for the studied
system. We emphasize that the mean motion resonance and apsidal locking can act
as two important mechanisms of stabilizing the system. In addition, we further
investigate the secular dynamics of this system by comparing the numerical
results with those given by Laplace-Lagrange secular theory.",0301636v2
2003-02-06,A generalization of the Lagrangian points: studies of resonance for highly eccentric orbits,"We develop a framework based on energy kicks for the evolution of
high-eccentricity long-period orbits with Jacobi constant close to 3 in the
restricted circular planar three-body problem where the secondary and primary
masses have mass ratio mu << 1. We use this framework to explore mean-motion
resonances between the test particle and the secondary mass. This approach
leads to (i) a redefinition of resonance orders to reflect the importance of
interactions at periapse; (ii) a pendulum-like equation describing the
librations of resonance orbits; (iii) an analogy between these new fixed points
and the Lagrangian points as well as between librations around the fixed points
and the well known tadpole and horseshoe orbits; (iv) a condition a ~ mu^(-2/5)
for the onset of chaos at large semimajor axis a; (v) the existence of a range
mu < ~5 x 10^(-6) in secondary mass for which a test particle initially close
to the secondary cannot escape from the system, at least in the planar problem;
(vi) a simple explanation for the presence of asymmetric librations in exterior
1:N resonances.",0302135v1
2006-02-22,The dynamics of eccentric accretion discs in superhump systems,"We have applied an eccentric accretion disc theory in simplified form to the
case of an accretion disc in a binary system, where the disc contains the 3:1
Lindblad resonance. This is relevant to the case of superhumps in SU Ursae
Majoris cataclysmic variables and other systems, where it is thought that this
resonance leads to growth of eccentricity and a modulation in the light curve
due to the interaction of a precessing eccentric disc with tidal stresses. A
single differential equation is formulated which describes the propagation,
resonant excitation and viscous damping of eccentricity. The theory is first
worked out in the simple case of a narrow ring and leads to the conclusion that
the eccentricity distribution is locally suppressed by the presence of the
resonance, creating a dip in the eccentricity at the resonant radius.
Application of this theory to the superhump case confirms this conclusion and
produces a more accurate expression for the precession rate of the disc than
has been previously accomplished with simple dynamical estimates.",0602492v1
2006-02-25,The 2:1 resonant exoplanetary system orbiting HD73526,"We report the detection of a second exoplanet orbiting the G6V dwarf HD73526.
This second planet has an orbital period of 377 d, putting it in a 2:1
resonance with the previously known exoplanet, the orbital period for which is
updated to 188d. Dynamical modeling of the combined system allows solution for
a self-consistent set of orbital elements for both components. HD73526 is the
fourth exoplanetary system (of a total of 18 systems with 2 or more components
currently known) to have components detected in 2:1 resonance. Finding such a
large fraction of multiple planets (more than 20 per cent) in 2:1 resonance
strongly suggests that orbital migration, halted by stabilisation in a trapping
resonance, plays an important role in the evolution of exoplanets in multiple
planet systems.",0602557v1
2006-08-22,Propeller activated resonances and the fate of short period cataclysmic variables,"We show that the combination of a weak magnetic propeller and accretion disc
resonances can effectively halt accretion in short period cataclysmic variables
for large fractions of their lifetimes. This may help to explain the
discrepancy between the observed and predicted orbital period distributions of
cataclysmic variables at short periods. Orbital resonances cause the disc to
become eccentric, allowing material to fall back onto the donor star or out of
the system. A weak magnetic field on a rapidly spinning primary star propels
disc material outwards, allowing it to access these resonances. Numerical and
analytic calculations show that this state can be long lived (~10^11 yr). This
is because the magnetic propeller is required only to maintain access to the
resonances, and not to push matter out of the Roche lobe, so that the spin down
time-scale is much longer than for a classical propeller model.",0608458v1
2006-11-30,On Secular Resonances of Small Bodies in the Planetary Systems,"We investigate the secular resonances for massless small bodies and
Earth-like planets in several planetary systems. We further compare the results
with those of Solar System. For example, in the GJ 876 planetary system, we
show that the secular resonances $\nu_1$ and $\nu_2$ (respectively, resulting
from the inner and outer giant planets) can excite the eccentricities of the
Earth-like planets with orbits 0.21 AU $\leq a <$ 0.50 AU and eject them out of
the system in a short timescale. However, in a dynamical sense, the potential
zones for the existence of Earth-like planets are in the area 0.50 AU $\leq a
\leq$ 1.00 AU, and there exist all stable orbits last up to $10^5$ yr with low
eccentricities. For other systems, e.g., 47 UMa, we also show that the
Habitable Zones for Earth-like planets are related to both secular resonances
and mean motion resonances in the systems.",0612001v1
1999-04-20,Birth of resonances in the spin-orbit problem of Celestial Mechanics,"The behaviour of resonances in the spin-orbit coupling in Celestial Mechanics
is investigated. We introduce a Hamiltonian nearly-integrable model describing
an approximation of the spin-orbit interaction. A parametric representation of
periodic orbits is presented. We provide explicit formulae to compute the
Taylor series expansion in the perturbing parameter of the function describing
this parametrization. Then we compute approximately the radius of convergence
providing an indication of the stability of the periodic orbit. This quantity
is used to describe the different probabilities of capture into resonance. In
particular, we notice that for low values of the orbital eccentricity the only
significative resonance is the synchronous one. Higher order resonances
(including 1:2, 3:2, 2:1) appear only as the orbital eccentricity is increased.",9904035v1
1994-06-03,Resonant scattering on impurities in the Quantum Hall Effect,"We develop a new approach to carrier transport between the edge states via
resonant scattering on impurities, which is applicable both for short and long
range impurities. A detailed analysis of resonant scattering on a single
impurity is performed. The results are used for study of the inter-edge
transport by multiple resonant hopping via different impurities' sites. It is
shown that the total conductance can be found from an effective Schroedinger
equation with constant diagonal matrix elements in the Hamiltonian, where the
complex non-diagonal matrix elements are the amplitudes of a carrier hopping
between different impurities. It is explicitly demonstrated how the complex
phase leads to Aharonov-Bohm oscillations in the total conductance. Neglecting
the contribution of self-crossing resonant-percolation trajectories, one finds
that the inter-edge carrier transport is similar to propagation in
one-dimensional system with off-diagonal disorder. We demonstrated that each
Landau band has an extended state $\bar E_N$, while all other states are
localized. The localization length behaves as $L_N^{-1}(E)\sim (E-\bar E_N)^2$.",9406022v2
1995-06-15,Finite Temperature Resonant Magnetotunneling in AlGaAs-GaAs-AlGaAs Heterostructures,"We have analyzed the effect of electron-LO phonon interaction in a
double-barrier resonant tunneling structure under a magnetic field {\bf B}
applied parallel to the tunneling current. While the low temperature
anti-crossing phenomenon has already been investigated, here we study the
phonon absorption resonant magnetotunneling at finite temperatures. The
Matsubara technique is used to sum up resonant diagrams of higher orders, and
the result is selfconsistently renormalized. The phonon absorption tunneling
spectrum has been calculated numerically. The result shows that the
phonon-absorption process produces two broad inelastic wings on the main
elastic tunneling peak, the strength of which is sensitive to the resonant
condition, and grows with increasing temperature. The width of the inelastic
wings are proportional to $B^{1/2}$. This is in contrast to the appearance of
anti-crossing in the phonon emission tunneling process. The difference is due
to the fact that the phonon emission is a coherent process, while the
absorption is a typical incoherent process since absorbed real phonons have
random phases.",9506068v1
1995-07-26,Statistics of S-matrix poles in Few-Channel Chaotic Scattering: Crossover from Isolated to Overlapping Resonances,"We derive the explicit expression for the distribution of resonance widths in
a chaotic quantum system coupled to continua via M equivalent open channels. It
describes a crossover from the $\chi^2$ distribution (regime of isolated
resonances) to a broad power-like distribution typical for the regime of
overlapping resonances. The first moment is found to reproduce exactly the
Moldauer-Simonius relation between the mean resonance width and the
transmission coefficient. This fact may serve as another manifestation of
equivalence between the spectral and the ensemble averaging.",9507117v3
1995-10-20,"Resonant Andreev Scattering In Phase-Coherent, Superconducting Nanostructures","Analytic predictions for resonant transport in three generic structures are
presented. For a structure comprising a normal (N) contact - normal dot (NDOT)
- superconducting (S) contact, we predict that finite voltage, differential
conductance resonances are destroyed by the switching on of superconductivity
in the S-contact. In the weak coupling limit, the surviving resonances have a
double-peaked line-shape. Secondly, we demonstrate that resonant Andreev
interferometers can provide galvonometric magnetic flux detectors, with a
sensitivity in excess of the flux quantum. Finally, for a superconducting dot
(SDOT) connected to normal contacts (N), we show that the onset of
superconductivity can increase the sub-gap conductance, in contrast with the
usual behaviour of a tunnel junction.",9510117v1
1996-03-01,Re-entrant resonant tunneling,"We study the effect of electron-electron interactions on the
resonant-tunneling spectroscopy of the localized states in a barrier. Using a
simple model of three localized states, we show that, due to the Coulomb
interactions, a single state can give rise to two resonant peaks in the
conductance as a function of gate voltage, G(Vg). We also demonstrate that an
additional higher-order resonance with Vg-position in between these two peaks
becomes possibile when interactions are taken into account. The corresponding
resonant-tunneling process involves two-electron transitions. We have observed
both these effects in GaAs transistor microstructures by studying the time
evolution of three adjacent G(Vg) peaks caused by fluctuating occupation of an
isolated impurity (modulator). The heights of the two stronger peaks exibit
in-phase fluctuations. The phase of fluctuations of the smaller middle peak is
opposite. The two stronger peaks have their origin in the same localized state,
and the third one corresponds to a co-tunneling process.",9603006v1
1996-05-09,Two-magnon Raman scattering in a spin density wave antiferromagnet,"We present the results for a model calculation of resonant two-magnon Raman
scattering in a spin density wave (SDW) antiferromagnet. The resonant
enhancement of the two-magnon intensity is obtained from a microscopic analysis
of the photon-magnon coupling vertex. By combining magnon-magnon interactions
with `triple resonance` phenomena in the vertex function the resulting
intensity line shape is found to closely resemble the measured two-magnon Raman
signal in antiferromagnetic cuprates. Both, resonant and non-resonant Raman
scattering are discussed for the SDW antiferromagnet and a comparison is made
to the conventional Loudon-Fleury theory of two-magnon light scattering.",9605056v1
1997-08-30,Localization Properties of the Periodic Random Anderson Model,"We consider diagonal disordered one-dimensional Anderson models with an
underlying periodicity. We assume the simplest periodicity, i.e., we have
essentially two lattices, one that is composed of the random potentials and the
other of non-random potentials. Due to the periodicity special resonance
energies appear, which are related to the lattice constant of the non-random
lattice. Further on two different types of behaviors are observed at the
resonance energies. When a random site is surrounded by non-random sites, this
model exhibits extended states at the resonance energies, whereas otherwise all
states are localized with, however, an increase of the localization length at
these resonance energies. We study these resonance energies and evaluate the
localization length and the density of states around these energies.",9709002v1
1997-10-14,Pi excitation of the t-J model,"In this paper, we present analytical and numerical calculations of the pi
resonance in the t-J model. We show in detail how the pi resonance in the
particle-particle channel couples to and appears in the dynamical spin
correlation function in a superconducting state. The contribution of the pi
resonance to the spin excitation spectrum can be estimated from general
model-independent sum rules, and it agrees with our detailed calculations. The
results are in overall agreement with the exact diagonalization studies of the
t-J model. Earlier calculations predicted the correct doping dependence of the
neutron resonance peak in the YBCO superconductor, and in this paper detailed
energy and momentum dependence of the spin correlation function is presented.
The microscopic equations of motion obtained within current formalism agree
with that of the SO(5) nonlinear sigma model, where the pi resonance is
interpreted as a pseudo Goldstone mode of the spontaneous SO(5) symmetry
breaking.",9710139v1
1997-11-25,Resonant tunneling of electromagnetic waves through polariton gaps,"We consider resonant tunneling of electromagnetic waves through an optical
barrier formed by dielectric layers with the frequency dispersion of their
dielectric permiability. The frequency region between lower and upper polariton
branches in these materials presents a stop band for electromagnetic waves. We
show that resonance tunneling through this kind of barriers is qualitatevely
different from tunneling through other kind of optical barriers as well as from
quantum mechanic tunneling through a rectangular barrier. We find that the
width of the resonance maxima of the transmission coeffcient tends to zero as
frequency approach the lower boundary of the stop band in a very sharp
non-analytical way. Resonance transmission peaks give rise to new photonic
bands inside the stop band if one considers periodical array of the layers.",9711268v2
1998-03-23,Nonstationary Stochastic Resonance in a Single Neuron-Like System,"Stochastic resonance holds much promise for the detection of weak signals in
the presence of relatively loud noise. Following the discovery of nondynamical
and of aperiodic stochastic resonance, it was recently shown that the
phenomenon can manifest itself even in the presence of nonstationary signals.
This was found in a composite system of differentiated trigger mechanisms
mounted in parallel, which suggests that it could be realized in some
elementary neural networks or nonlinear electronic circuits. Here, we find that
even an individual trigger system may be able to detect weak nonstationary
signals using stochastic resonance. The very simple modification to the trigger
mechanism that makes this possible is reminiscent of some aspects of actual
neuron physics. Stochastic resonance may thus become relevant to more types of
biological or electronic systems injected with an ever broader class of
realistic signals.",9803282v1
1998-11-25,Multifractal scaling of electronic transmission resonances in perfect and imperfect Fibonacci $δ$-function potentials,"We present here a detailed multifractal scaling study for the electronic
transmission resonances with the system size for an infinitely large one
dimensional perfect and imperfect quasiperiodic system represented by a
sequence of $\delta$-function potentials. The electronic transmission
resonances in the energy minibands manifest more and more fragmented nature of
the transmittance with the change of system sizes. We claim that when a small
perturbation is randomly present at a few number of sites, the nature of
electronic states will change and this can be understood by studying the
electronic transmittance with the change of system size. We report the
different critical states manifested in the size variation of the transmittance
corresponding to the resonant energies for both perfect and imperfect cases
through multifractal scaling study for few of these resonances.",9811350v1
1999-03-11,Resonant neutron scattering on the high Tc cuprates and pi and eta excitation of the t-J and Hubbard models,"We review the explanation for resonant neutron scattering experiments in
$YBa_2Cu_3O_{6+\delta}$ and $Bi_2 Sr_2 Ca_2 O_{8+\delta}$ materials from the
point of view of triplet excitation in the particle-particle channel, the pi
excitation. Relation of these resonances to the superconducting condensation
energy and their role in stabilizing the superconducting state is discussed.
Due to the superconducting fluctuations, the pi resonance may appear as a broad
peak above Tc. Analogue problem to the pi excitation for the case of s-wave
pairing, the eta excitation, is considered in the strong coupling limit with an
emphasis on the resonance precursors in a state with no long range order.",9903195v1
1999-03-16,Resonant states and order-parameter suppression near point-like impurities in d-wave superconductors,"We examine the role of order-parameter suppression in the development of
low-energy peaks (i.e., resonances) in the tunneling density of states near a
non-magnetic impurity in a d-wave superconductor. Without order-parameter
suppression, the zero-energy resonance appears only in the unitary (i.e.,
strong impurity) limit. However, suppression makes the resonance appear even
when the impurity is much weaker. To model this situation, we make the physical
hypothesis that the order parameter is reduced whenever one electron of a
Cooper pair encounters the impurity, a hypothesis that retains the exact
solvability of the problem. In this way, we determine that suppression of the
order parameter drives the effective strength of the impurity towards the
unitary limit. We determine the order-parameter reduction variationally, and
show that the ratios between the main energy scales--the band width and
superconducting gap--strongly affect this reduction and, in consequence, the
position and width of the resonance.",9903252v1
1999-10-25,Coulomb Blockade Resonances in Quantum Wires,"The conductance through a quantum wire of cylindrical cross section and a
weak bulge is solved exactly for two electrons within the Landauer-Buettiker
formalism. We show that this 'open' quantum dot exhibits spin-dependent Coulomb
blockade resonances resulting in two anomalous structure on the rising edge to
the first conductance plateau, one near 0.25(2e^2/h), related to a singlet
resonance, and one near 0.7(2e^2/h), related to a triplet resonance. These
resonances are generic and robust, occurring for other types of quantum wire
and surviving to temperatures of a few degrees.",9910399v1
1999-11-30,Anomalous resonance phenomena of solitary waves with internal modes,"We investigate the non-parametric, pure ac driven dynamics of nonlinear
Klein-Gordon solitary waves having an internal mode of frequency $\Omega_i$. We
show that the strongest resonance arises when the driving frequency
$\delta=\Omega_i/2$, whereas when $\delta=\Omega_i$ the resonance is weaker,
disappearing for nonzero damping. At resonance, the dynamics of the kink center
of mass becomes chaotic. As we identify the resonance mechanism as an {\em
indirect} coupling to the internal mode due to its symmetry, we expect similar
results for other systems.",9911487v1
2000-11-14,Resonances in one and two rows of triangular Josephson junction cells,"We present an experimental and analytical study of resonances in the
current-voltage characteristics of single and double row triangular Josephson
arrays. The magnetic field dependences of the voltage positions of the
resonances have been measured for various cell inductances and junction
critical currents. In double row arrays, we have observed a peculiar resonance,
whose voltage position decreases with magnetic field. We derive the spectrum of
linear electromagnetic waves propagating in the arrays. In the double row
array, the spectrum consists of many branches that differ by the behavior of
the Josephson junctions transverse to the bias current direction. The measured
magnetic field dependence of the resonance voltages is mapped to the linear
mode spectrum and good agreement between experiments and model is found.",0011237v1
2000-11-17,Comparing schemes of displacement detection and subharmonic generation in nanomachined mechanical resonators,"We present measurements on nanomechanical resonators operating in the radio
frequency range. We apply a setup which allows the comparison of two schemes of
displacement detection for mechanical resonators, namely conventional power
reflection measurements of a probing signal and direct detection by capacitive
coupling via a gate electrode. For capacitive detection, we employ an on-chip
preamplifier, which enables direct measurements of the resonator's
displacement. We observe that the response of the mechanical resonator depends
on the detection technique applied, which is verified in model calculations. We
show results on the detection of subharmonics.-Paper withdrawn",0011299v4
2000-11-30,Random matrix theory for systems with an approximate symmetry and widths of acoustic resonances in thin chaotic plates,"We discuss a random matrix model of systems with an approximate symmetry and
present the spectral fluctuation statistics and eigenvector characteristics for
the model. An acoustic resonator like, e.g., an aluminium plate may have an
approximate symmetry. We have measured the frequency spectrum and the widths
for acoustic resonances in thin aluminium plates, cut in the shape of the
so-called three-leaf clover. Due to the mirror symmetry through the middle
plane of the plate, each resonance of the plate belongs to one of two mode
classes and we show how to separate the modes into these two classes using
their measured widths. We compare the spectral statistics of each mode class
with results for the Gaussian orthogonal ensemble. By cutting a slit of
increasing depth on one face of the plate, we gradually break the mirror
symmetry and study the transition that takes place as the two classes are
mixed. Presenting the spectral fluctuation statistics and the distribution of
widths for the resonances, we find that this transition is well described by
the random matrix model.",0011517v1
2001-01-11,Pigmy resonances in artificial nuclei: far-infrared absorption by electron-hole droplets,"The structure of E1 resonances is examined in a microscopic random phase
approximation calculation for neutral, symmetric, closed shell, electron-hole
systems in a quantum dot. The number of electron-hole pairs, N, is varied from
6 to 42. The ocurrence of small, but distinct, E1 peaks in the far infrared
spectra located in the low energy tail of the giant dipole resonance and
consisting of highly coherent electron-hole excitations is predicted. These
pigmy resonances account for about 2 % of the dipole energy-weighted
photoabsorption sum rule. A very weak dependence of the average pigmy resonance
energy on the number of electron-hole pairs is found.",0101173v1
2001-01-18,Coherent multiple Andreev reflections and current resonances in SNS junctions,"We study coherent multiple Andreev reflections in quantum SNS junctions of
finite length and arbitrary transparency. The presence of superconducting bound
states in these junctions gives rise to great enhancement of the subgap
current. The effect is most pronounced in low-transparency junctions, $D\ll1$,
and in the interval of applied voltage $\Delta/2<eV<\Delta$, where the
amplitude of the current structures is proportional to the first power of the
junction transparency $D$. The resonant current structures consist of steps and
oscillations of the two-particle current and also of multiparticle resonance
peaks. The positions of the two-particle current structures have pronounced
temperature dependence which scales with $\Delta(T)$, while the positions of
the multiparticle resonances have weak temperature dependence, being mostly
determined by the junction geometry. Despite the large resonant two-particle
current, the excess current at large voltage is small and proportional to
$D^2$. Pacs: 74.50.+r, 74.80.Fp, 74.20.Fg, 73.23.Ad",0101283v1
2001-10-05,Eigenstates of a Small Josephson Junction Coupled to a Resonant Cavity,"We carry out a quantum-mechanical analysis of a small Josephson junction
coupled to a single-mode resonant cavity. We find that the eigenstates of the
combined junction-cavity system are strongly entangled only when the gate
voltage applied at one of the superconducting islands is tuned to certain
special values. One such value corresponds to the resonant absorption of a
single photon by Cooper pairs in the junction. Another special value
corresponds to a {\em two-photon} absorption process. Near the single-photon
resonant absorption, the system is accurately described by a simplified model
in which only the lowest two levels of the Josephson junction are retained in
the Hamiltonian matrix. We noticed that this approximation does not work very
well as the number of photons in the resonator increases. Our system shows also
the phenomenon of ``collapse and revival'' under suitable initial conditions,
and our full numerical solution agrees with the two level approximation result.",0110117v1
2001-10-26,Theory and experiment of the ESR of Co$^{2+}$ in Zn$_2$ % (OH)PO$_4$ and Mg$_2$(OH)AsO$_4$,"Experiments of Electron Spin Resonance (ESR) were performed on Co$% ^{2+}$
substituting Zn$^{2+}$ or Mg$^{2+}$ in powder samples of Zn$_2$(OH)PO$_4$ and
Mg$_2$(OH)AsO$_4$. The observed resonances are described with a theoretical
model that considers the departures from the two perfect structures. It is
shown that the resonance in the penta-coordinated complex is allowed, and the
crystal fields that would describe the resonance of the Co$^{2+}$ in the two
environments are calculated. The small intensity of the resonance in the
penta-coordinated complex is explained assuming that this site is much less
populated than the octahedral one; this assumption was verified by a molecular
calculation of the energies of the two environments, with both Co and Zn as
central ions in Zn$_2$(OH)PO$_4$.",0110563v1
2001-11-29,Zeeman effects on the impurity-induced resonances in d-wave superconductors,"It is shown how the resonant states induced by a single spinless impurity in
a d-wave superconductor evolve under the effect of an applied Zeeman magnetic
field. Moreover, it is demonstrated that the spin-orbit coupling to the
impurity potential can have important and characteristic effects on the
resonant states and their response to the Zeeman field, especially when the
impurity is close to the unitary limit. For zero or very small spin-orbit
interaction, the resonant states becomes Zeeman splitted by the magnetic field
while when the spin-orbit coupling is important, new low-lying resonances arise
which do not show any Zeeman splitting.",0111554v2
2001-12-15,Resonance Superfluidity: Renormalization of Resonance Scattering Theory,"We derive a theory of superfluidity for a dilute Fermi gas that is valid when
scattering resonances are present. The treatment of a resonance in many-body
atomic physics requires a novel mean-field approach starting from an
unconventional microscopic Hamiltonian. The mean-field equations incorporate
the microscopic scattering physics, and the solutions to these equations
reproduce the energy-dependent scattering properties. This theory describes the
high-$T_c$ behavior of the system, and predicts a value of $T_c$ which is a
significant fraction of the Fermi temperature. It is shown that this novel
mean-field approach does not break down for typical experimental circumstances,
even at detunings close to resonance. As an example of the application of our
theory we investigate the feasibility for achieving superfluidity in an
ultracold gas of fermionic $^6$Li.",0112283v1
2001-12-24,Paramagnetic and antiferromagnetic resonances in the diamagnetically diluted Haldane magnet PbNi2V2O8,"The impurity-induced antiferromagnetic ordering of the doped Haldane magnet
Pb(Ni{1-x}Mg{x})2V2O8 (0 < x <0.06) was studied by electron spin resonance
(ESR) on ceramic samples in the frequency range 9-110 GHz. Below the N\'{e}el
temperature a transformation of the ESR spectrum was found, indicating an
antiferromagnetic resonance mode of spin precession. The excitation gap of the
spin-wave spectrum increases with increasing Mg-concentration $x$ in the same
manner as the N\'{e}el temperature, reaching its maximum value of 80 GHz at x >
0.04. At small concentrations x < 0.02 the signals of antiferromagnetic
resonance were found to coexist with the signal of the paramagnetic resonance
indicating a microscopic separation of the magnetic phases.",0112443v1
2002-01-03,Cyclotron resonance in the layered perovskite superconductor Sr2RuO4,"We report a detailed study of the magnetic-field-orientation dependence of
the millimetre-wave magnetoconductivity of the superconductor Sr2RuO4 We find
two harmonic series of cyclotron resonances. We assign the first, corresponding
to a quasiparticle mass of $4.29 \pm 0.05 m_{\rm e}$, where $m_{\rm e}$ is the
free-electron mass, to the $\beta$ Fermi-surface section. We assign the second
series, which contains only odd harmonics, to cyclotron resonance of the
$\gamma$ Fermi-surface section, yielding a quasiparticle mass of $12.35 \pm
0.20 m_{\rm e}$. A third, single cyclotron resonance, corresponding to a
quasiparticle mass of $5.60 \pm 0.03 m_{\rm e}$, is attributed to the $\alpha$
Fermi-surface section. In addition, we find a very strong absorption mode in
the presence of a magnetic field component parallel to the
quasi-two-dimensional planes of the sample. Its dependence on the orientation
of the magnetic field cannot be described in the context of conventional
cyclotron resonance, and the origin of this mode is not yet clear.",0201032v1
2002-05-18,Resonant Two-Magnon Raman Scattering and Photoexcited States in Two-Dimensional Mott Insulators,"We investigate the resonant two-magnon Raman scattering in two-dimensional
(2D) Mott insulators by using a half-filled 2D Hubbard model in the strong
coupling limit. By performing numerical diagonalization calculations for small
clusters, we find that the Raman intensity is enhanced when the incoming photon
energy is not near the optical absorption edge but well above it, being
consistent with experimental data. The absence of resonance near the gap edge
is associated with the presence of background spins, while photoexcited states
for resonance are found to be characterized by the charge degree of freedom.
The resonance mechanism is different from those proposed previously.",0205388v2
2002-07-02,Decay of an ultracold fermionic lithium gas near a Feshbach resonance,"We studied the magnetic field dependence of the inelastic decay of an
ultracold, optically trapped 6-Li gas of different spin compositions. The spin
mixture of the two lowest hyperfine states showed two decay resonances at 550 G
and 680 G due to two-body collisions, close to the predicted Feshbach resonance
of the elastic s-wave collisions at 800 G. The rapid decay near Feshbach
resonances found in bosonic gases was found to be suppressed by the Pauli
exclusion principle. The observed lifetimes of several hundred milliseconds are
much longer than the expected time for Cooper pair formation and the phase
transition to superfluidity in the vicinity of the Feshbach resonance.",0207046v3
2002-09-10,Numerical Studies of Fano Resonance in Quantum dots Embedded in AB Rings,"The Fano resonance in quantum dots embedded in Aharonov-Bohm rings is
examined theoretically, using two models of non-interacting electrons. The
first model yields an analytical expression for the conductance G. G is written
in an extended Fano form with a complex parameter. The shape of the resonance
can be asymmetric or symmetric, depending on the magnetic flux enclosed in the
ring. The ""phase"" of the resonance is changed continuously with increasing the
flux in two-terminal situations. These are in accordance with recent
experimental results. In the second model, we consider the dephasing effect on
the Fano resonance by numerical calculations.",0209229v1
2002-10-29,Feshbach resonances in rubidium 87: Precision measurement and analysis,"More than 40 Feshbach resonances in rubidium 87 are observed in the magnetic
field range between 0.5 and 1260 G for various spin mixtures in the lower
hyperfine ground state. The Feshbach resonances are observed by monitoring the
atom loss, and their positions are determined with an accuracy of 30 mG. In a
detailed analysis, the resonances are identified and an improved set of model
parameters for the rubidium interatomic potential is deduced. The elastic width
of the broadest resonance at 1007 G is predicted to be significantly larger
than the magnetic field resolution of the apparatus. This demonstrates the
potential for applications based on tuning the scattering length.",0210651v2
2002-11-11,Fermi Surface Study of Quasi-Two-Dimensional Organic Conductors by Magnetooptical Measurements,"Magnetooptical measurements of several quasi-two-dimensional (q2D) organic
conductors, which have simple Fermi surface structure, have been performed by
using a cavity perturbation technique. Despite of the simple Fermi surface
structure, magnetooptical resonance results show a dramatic difference for each
sample. Cyclotron resonances (CR) were observed for q-(BEDT-TTF)2I3 and
(BEDT-TTF)3Br(pBIB), while periodic orbit resonances (POR) were observed for
(BEDT-TTF)2Br(DIA) and (BEDT-TTF)3Cl(DFBIB). The selection of the resonance
seems to correspond with the skin depth for each sample. The effective mass of
POR seems to have a mass enhancement due to the many-body effect, while
effective mass of CR is independent of the strength of the electron-electron
interaction. The scattering time deduced from each resonance's linewidth will
be also presented.",0211194v1
2003-01-14,Auger Effect in the High-Resolution Ce 3d-edge Resonant Photoemission,"The bulk-sensitive Ce 4$f$ spectral weights of various Ce compounds including
CeFe$_2$, CeNi$_2$, and CeSi$_2$ were obtained with the resonant photoemission
technique at the Ce 3d-edge. We found the lineshapes change significantly with
the small change of the incident photon energy. Detailed analysis showed that
this phenomenon results primarily from the Auger transition between different
multiplet states of the Ce $\underline{3d_{5/2}}4f^2$ (bar denotes a hole)
electronic configuration in the intermediate state of the resonant process.
This tells us that extra care should be taken for the choice of the resonant
photon energy when extracting Ce 4$f$ spectral weights from the Ce 3$d$-edge
resonant photoemission spectra. The absorption energy corresponding to the
lowest multiplet structure of the Ce $\underline{3d_{5/2}}4f^2$ configuration
seems to be the logical choice.",0301211v1
2003-01-30,Microwave Resonance of 2D Wigner Crystal around integer Landau fillings,"We have observed a resonance in the real part of the finite frequency
diagonal conductivity using microwave absorption measurements in high quality
2D electron systems near {\em integer fillings}. The resonance exists in some
neighborhood of filling factor around corresponding integers and is
qualitatively similar to previously observed resonance of weakly pinned Wigner
crystal in high $B$ and very small filling factor regime. Data measured around
both $\nu=1$ and $\nu=2$ are presented. We interpret the resonance as the
signature of Wigner crystal state around integer Landau levels.",0301579v1
2003-04-23,An effective theory of Feshbach resonances and many-body properties of Fermi gases,"For calculating low-energy properties of a dilute gas of atoms interacting
via a Feshbach resonance, we develop an effective theory in which the
parameters that enter are an atom-molecule coupling strength and the magnetic
moment of the molecular resonance. We demonstrate that for resonances in the
fermionic systems $^{6}$Li and $^{40}$K that are under experimental
investigation, the coupling is so strong that many-body effects are appreciable
even when the resonance lies at an energy large compared with the Fermi energy.
We calculate a number of many-body effects, including the effective mass and
the lifetime of atomic quasiparticles in the gas.",0304535v2
2003-05-22,Resonances in 1D disordered systems: localization of energy and resonant transmission,"Localized states in one-dimensional open disordered systems and their
connection to the internal structure of random samples have been studied. It is
shown that the localization of energy and anomalously high transmission
associated with these states are due to the existence inside the sample of a
transparent (for a given resonant frequency) segment with the minimal size of
order of the localization length. A mapping of the stochastic scattering
problem in hand onto a deterministic quantum problem is developed. It is shown
that there is no one-to-one correspondence between the localization and high
transparency: only small part of localized modes provides the transmission
coefficient close to one. The maximal transmission is provided by the modes
that are localized in the center, while the highest energy concentration takes
place in cavities shifted towards the input. An algorithm is proposed to
estimate the position of an effective resonant cavity and its pumping rate by
measuring the resonant transmission coefficient. The validity of the analytical
results have been checked by extensive numerical simulations and wavelet
analysis.",0305532v2
2003-06-06,High temperature expansion applied to fermions near Feshbach resonance,"We show that, apart from a difference in scale, all of the surprising
recently observed properties of a degenerate Fermi gas near a Feshbach
resonance persist in the high temperature Boltzmann regime. In this regime, the
Feshbach resonance is unshifted. By sweeping across the resonance, a thermal
distribution of bound states (molecules) can be reversibly generated.
Throughout this process, the interaction energy is negative and continuous. We
also show that this behavior must persist at lower temperatures unless there is
a phase transition as the temperature is lowered. We rigorously demonstrate
universal behavior near the resonance.",0306187v4
2003-07-08,Resonant acousto-optics of microcavity polaritons,"We propose and analyze theoretically a resonant acousto-optic Stark effect
for microcavity (MC) polaritons parametrically driven by a surface acoustic
wave. For GaAs-based microcavities our scheme ``acoustic pumping - optical
probing'' deals with surface acoustic waves of frequency $\nu_{\rm SAW} \simeq
0.5 - 3$ GHz and intensity $I_{\rm SAW} \simeq 0.1 - 10$ mW/mm. The
acoustically-induced stop gaps in the MC polariton spectrum drastically change
the optical response of MC polaritons. Because an acoustically pumped intrinsic
semiconductor microcavity remains in its ground electronic state, no many-body
effects screen and weaken the resonant acousto-optic Stark effect. In the
meantime, this allows us to work out an exactly-solvable model for resonant
acousto-optics of MC polaritons which deals with giant acousto-optical
nonlinearities. Finally, we discuss possible applications of the proposed
resonant acoustic Stark effect for optical modulation and switching and
describe an acousto-optic device based on a (GaAs) microcavity driven by a
surface acoustic wave.",0307179v1
2003-09-24,Anomalous behavior of spin wave resonances in Ga_{1-x}Mn_{x}As thin films,"We report ferromagnetic and spin wave resonance absorption measurements on
high quality epitaxially grown Ga_{1-x}Mn_{x}As thin films. We find that these
films exhibit robust ferromagnetic long-range order, based on the fact that up
to seven resonances are detected at low temperatures, and the resonance
structure survives to temperatures close to the ferromagnetic transition. On
the other hand, we observe a spin wave dispersion which is linear in mode
number, in qualitative contrast with the quadratic dispersion expected for
homogeneous samples. We perform a detailed numerical analysis of the
experimental data and provide analytical calculations to demonstrate that such
a linear dispersion is incompatible with uniform magnetic parameters. Our
theoretical analysis of the ferromagnetic resonance data, combined with the
knowledge that strain-induced anisotropy is definitely present in these films,
suggests that a spatially dependent magnetic anisotropy is the most likely
reason behind the anomalous behavior observed.",0309566v2
2003-11-06,Cyclotron resonance of correlated electrons in semiconductor heterostructures,"The cyclotron resonance absorption of two-dimensional electrons in
semiconductor heterostructures in high magnetic fields is investigated. It is
assumed that the ionized impurity potential is a dominant scattering mechanism,
and the theory explicitly takes the Coulomb correlation effect into account
through the Wigner phonons. The cyclotron resonance linewidth is in
quantitative agreement with the experiment in the Wigner crystal regime at
T=4.2K. Similar to the cyclotron resonance theory of the charge density waves
pinned by short-range impurities, the present results for the long-range
scattering also show the doubling of the resonance peaks. However, unlike the
case of the charge density waves, our theory gives the pinning mode independent
of the bulk compressibility of the substrate materials.",0311134v1
2003-11-11,Spin-resonance modes of the spin-gap magnet TlCuCl_3,"Three kinds of magnetic resonance signals were detected in crystals of the
spin-gap magnet TlCuCl_3.
  First, we have observed the microwave absorption due to the excitation of the
transitions between the singlet ground state and the excited triplet states.
This mode has the linear frequency-field dependence corresponding to the
previously known value of the zero-field spin-gap of 156 GHz and to the closing
of spin-gap at the magnetic field H_c of about 50 kOe.
  Second, the thermally activated resonance absorption due to the transitions
between the spin sublevels of the triplet excitations was found. These
sublevels are split by the crystal field and external magnetic field.
  Finally, we have observed antiferromagnetic resonance absorption in the
field-induced antiferromagnetic phase above the critical field H_c. This
resonance frequency is strongly anisotropic with respect to the direction of
the magnetic field.",0311243v2
2003-11-21,Fano Resonance in a Quantum Wire with a Side-coupled Quantum Dot,"We report a transport experiment on the Fano effect in a quantum connecting
wire (QW) with a side-coupled quantum dot (QD). The Fano resonance occurs
between the QD and the ""T-shaped"" junction in the wire, and the transport
detects anti-resonance or forward scattered part of the wavefunction. While in
this geometry it is more difficult to tune the shape of the resonance than in
the previously reported Aharonov-Bohm-ring type interferometer, the resonance
purely consists of the coherent part of transport. By utilizing this advantage,
we have qualitatively explained the temperature dependence of the Fano effect
by including the thermal broadening and the decoherence. We have also proven
that this geometry can be a useful interferometer to measure the phase
evolution of electrons at a QD.",0311497v2
2003-11-24,The Fano resonance for Anderson impurity systems,"We present a general theory for the Fano resonance in Anderson impurity
systems. It is shown that the broadening of the impurity level leads to an
additional and important contribution to the Fano resonance around the Fermi
surface, especially in the mixed valence regime. This contribution results from
the interference between the Kondo resonance and the broadened impurity level.
Being applied to the scanning tunnelling microscopic experiments, we find that
our theory gives a consistent and quantitative account for the Fano resonance
lineshapes for both Co and Ti impurities on Au or Ag surfaces. The Ti systems
are found to be in the mixed valence regime.",0311533v2
2004-01-27,Observation of resonance condensation of fermionic atom pairs,"We have observed condensation of fermionic atom pairs in the BCS-BEC
crossover regime. A trapped gas of fermionic 40K atoms is evaporatively cooled
to quantum degeneracy and then a magnetic-field Feshbach resonance is used to
control the atom-atom interactions. The location of this resonance is precisely
determined from low-density measurements of molecule dissociation. In order to
search for condensation on either side of the resonance we introduce a
technique that pairwise projects fermionic atoms onto molecules; this enables
us to measure the momentum distribution of fermionic atom pairs. The transition
to condensation of fermionic atom pairs is mapped out as a function of the
initial atom gas temperature T compared to the Fermi temperature TF for
magnetic-field detunings on both the BCS and BEC sides of the resonance.",0401554v1
2004-03-24,Resonant magnetic excitations at high energy in superconducting $\bf YBa_2Cu_3O_{6.85}$,"A detailed inelastic neutron scattering study of the high temperature
superconductor $\rm YBa_2Cu_3O_{6.85}$ provides evidence of new resonant
magnetic features, in addition to the well known resonant mode at 41 meV: (i) a
commensurate magnetic resonance peak at 53 meV with an even symmetry under
exchange of two adjacent $\rm CuO_2$ layers; and (ii) high energy
incommensurate resonant spin excitations whose spectral weight is around 54
meV. The locus and the spectral weight of these modes can be understood by
considering the momentum shape of the electron-hole spin-flip continuum of
d-wave superconductors. This provides new insight into the interplay between
collective spin excitations and the continuum of electron-hole excitations.",0403609v1
2004-04-27,Ultrahigh-Field Hole Cyclotron Resonance Absorption in InMnAs Films,"We have carried out an ultrahigh-field cyclotron resonance study of p-type
In1-xMnxAs films, with Mn composition x ranging from 0% to 2.5%, grown on GaAs
by low-temperature molecular-beam epitaxy. Pulsed magnetic fields up to 500 T
were used to make cyclotron resonance observable in these low-mobility samples.
The clear observation of hole cyclotron resonance is direct evidence of the
existence of a large number of itinerant, effective-mass-type holes rather than
localized d-like holes. It further suggests that the p-d exchange mechanism is
more favorable than the double exchange mechanism in this narrow gap InAs-based
dilute magnetic semiconductor. In addition to the fundamental heavy-hole and
light-hole cyclotron resonance absorption appearing near the
high-magnetic-field quantum limit, we observed many inter-Landau-level
absorption bands whose transition probabilities are stronglydependent on the
sense of circular polarization of the incident light.",0404635v1
2004-04-28,Resonance effects on the crossover of bosonic to fermionic superfluidity,"Feshbach scattering resonances are being utilized in atomic gases to explore
the entire crossover region from a Bose-Einstein Condensation (BEC) of
composite bosons to a Bardeen-Cooper-Schrieffer (BCS) of Cooper pairs. Several
theoretical descriptions of the crossover have been developed based on an
assumption that the fermionic interactions are dependent only on the value of a
single microscopic parameter, the scattering length for the interaction of
fermion particles. Such a picture is not universal, however, and is only
applicable to describe a system with an energetically broad Feshbach resonance.
In the more general case in which narrow Feshbach resonances are included in
the discussion, one must consider how the energy dependence of the scattering
phase shift affects the physical properties of the system. We develop a
theoretical framework which allows for a tuning of the scattering phase shift
and its energy dependence, whose parameters can be fixed from realistic
scattering solutions of the atomic physics. We show that BCS-like nonlocal
solutions may build up in conditions of resonance scattering, depending on the
effective range of the interactions.",0404672v1
2004-05-28,Theoretical study of electron states in Au chains on NiAl(110),"We have carried out a density functional study of unoccupied, resonance
states in a single Au atom, dimers, a trimer and infinite Au chains on the
NiAl(110) surface. Two inequivalent orientations of the ad-chains with
substantially different interatomic distances were considered. From the study
of the evolution of the electron states in an Au chain from being isolated to
adsorbed, we find that the resonance states derive from the 6$s$ states of the
Au atoms, which hybridize strongly with the substrate states and develop a
$p$-like polarization. The calculated resonance states and LDOS images were
analyzed in a simple tight-binding, resonance model. This model clarifies (1)
the physics of direct and substrate-mediated adatom-adatom interactions and (2)
the physics behind the enhancements of the LDOS at the ends of the adatom
chains, and (3) the physical meaning of the ""particle-in-box"" model used in the
analysis of observed resonance states. The calculated effective mass and band
bottom energy are in good agreement with experimental data obtained from
scanning tunnelling spectroscopy.",0405675v1
2004-06-02,Generation of Squeezed States of Nanomechanical Resonators by Reservoir Engineering,"An experimental demonstration of a non-classical state of a nanomechanical
resonator is still an outstanding task. In this paper we show how the resonator
can be cooled and driven into a squeezed state by a bichromatic microwave
coupling to a charge qubit. The stationary oscillator state exhibits a reduced
noise in one of the quadrature components by a factor of 0.5 - 0.2. These
values are obtained for a 100 MHz resonator with a Q-value of 10$^4$ to 10$^5$
and for support temperatures of T $\approx$ 25 mK. We show that the coupling to
the charge qubit can also be used to detect the squeezed state via measurements
of the excited state population. Furthermore, by extending this measurement
procedure a complete quantum state tomography of the resonator state can be
performed. This provides a universal tool to detect a large variety of
different states and to prove the quantum nature of a nanomechanical
oscillator.",0406058v1
2004-06-08,Observation of Heteronuclear Feshbach Resonances in a Bose-Fermi Mixture,"Three magnetic-field induced heteronuclear Feshbach resonances were
identified in collisions between bosonic 87Rb and fermionic 40K atoms in their
absolute ground states. Strong inelastic loss from an optically trapped mixture
was observed at the resonance positions of 492, 512, and 543 +/- 2 G. The
magnetic-field locations of these resonances place a tight constraint on the
triplet and singlet cross-species scattering lengths, yielding -281 +/- 15 Bohr
and -54 +/- 12 Bohr, respectively. The width of the loss feature at 543 G is
3.7 +/- 1.5 G wide; this broad Feshbach resonance should enable experimental
control of the interspecies interactions.",0406208v1
2004-06-17,Mott insulator to superfluid transition of ultracold bosons in an optical lattice near a Feshbach resonance,"We study the phase diagram of ultracold bosons in an optical lattice near a
Feshbach resonance. Depending on the boson density, the strength of the optical
lattice potential and the detuning from resonance, the ground state can be a
Mott insulator, a superfluid phase with both an atomic and a molecular
condensate, or a superfluid phase with only a molecular condensate. Mott
insulator to superfluid transitions can be induced either by decreasing the
strength of the optical lattice potential or by varying the detuning from the
Feshbach resonance. Quite generally, we find that for a commensurate density
the ground-state may undergo several insulator-superfluid or
superfluid-insulator transitions as the magnetic field is varied through the
resonance.",0406396v2
2004-06-23,Observation of Fano-Resonances in Single-Wall Carbon Nanotubes,"We have explored the low-temperature linear and non-linear electrical
conductance $G$ of metallic carbon nanotubes (CNTs), which were grown by the
chemical-vapor deposition method. The high transparency of the contacts allows
to study these two-terminal devices in the high conductance regime. We observe
the expected four-fold shell pattern together with Kondo physics at
intermediate transparency {$G\alt 2e^2/h$} and a transition to the open regime
in which the maximum conductance is doubled and bound by $G_{max}=4e^2/h$. In
the high-$G$ regime, at the transition from a quantum dot to a weak link, the
CNT levels are strongly broadened. Nonetheless, sharp resonances appear
superimposed on the background which varies slowly with gate voltage. The
resonances are identified by their lineshape as Fano resonances. The origin of
Fano resonances is discussed along the modelling.",0406571v1
2004-06-25,Kondo resonance in a nanotube quantum dot coupled to a normal and a superconducting lead,"We report on electrical transport measurements through a carbon nanotube
quantum dot coupled to a normal and a superconducting lead. The ratio of Kondo
temperature and superconducting gap $T_{K}/\Delta$ is identified to govern the
transport properties of the system. In the case of $T_{K}<\Delta$ the
conductance resonance splits into two resonances at $\pm \Delta$. For the
opposite scenario $T_{K}>\Delta$ the conductance resonance persists, however
the conductance is not enhanced compared to the normal state due to a relative
asymmetry of the lead-dot couplings. Within this limit the data is in agreement
with a simple model of a resonant SN-interface.",0406638v1
2004-07-22,Broad versus narrow Fano-Feshbach resonances in the BCS-BEC crossover with trapped Fermi atom,"With reference to the broad and narrow Fano-Feshbach resonances of 6Li at
about 822 G and 543 G, we show that for the broad resonance a molecular
coupled-channel calculation can be mapped with excellent accuracy onto an
effective single-channel problem with a contact interaction. This occurs for a
wide enough range of the magnetic field, that the full BCS-BEC crossover can be
realized with a typical trap. For the narrow resonance, the mapping onto a
single-channel problem and the realization of the BCS-BEC crossover are
restricted to too narrow a range of the magnetic field to obtain them in
practice. In this way, the BCS-BEC crossover for Fermi atoms with the broad
resonance is placed on the same footing as the corresponding crossover for
different physical systems.",0407600v2
2004-09-02,ESR spectrometer with a loop-gap resonator for cw and time resolved studies in a superconducting magnet,"The design and performance of an electron spin resonance spectrometer
operating at 3 and 9 GHz microwave frequencies combined with a 9 T
superconducting magnet is described. The probehead contains a compact two-loop,
one gap resonator and is embedded in the variable temperature insert of the
magnet enabling measurements in the 0- 9 T magnetic field and 1.5-400 K\
temperature range. The spectrometer allows studies on systems where resonance
occurs at fields far above the $g$ $\approx 2$ paramagnetic condition such as
in strongly interacting spin systems. The low quality factor of the resonator
allows time resolved experiments such as e.g. longitudinally detected ESR. We
demonstrate the performance of the spectrometer on the MgB$_{2}$ superconductor
and the RbC$_{60}$ conducting alkaline fulleride polymer.",0409051v1
2004-09-15,Pulse Propagation in Resonant Tunneling,"We consider the analytically solvable model of a Gaussian pulse tunneling
through a transmission resonance with a Breit-Wigner characteristic. The
solution allows for the identification of two opposite pulse propagation
regimes: if the resonance is broad compared to the energetic width of the
incident Gaussian pulse a weakly deformed and slightly delayed transmitted
Gaussian pulse is found. In the opposite limit of a narrow resonance the dying
out of the transmitted pulse is dominated by the slow exponential decay
characteristic of a quasi-bound state with a long life time (decaying state).
We discuss the limitation of the achievable pulse transfer rate resulting from
the slow decay. Finally, it is demonstrated that for narrow resonances a small
second component is superimposed to the exponential decay which leads to
characteristic interference oscillations.",0409396v1
2004-09-22,Interaction of magnetic-dipolar modes with microwave-cavity electromagnetic fields,"We discuss the problem of magnetic-dipolar oscillations combined with
microwave resonators. The energy density of magnetic-dipolar or magnetostatic
(MS) oscillations in ferrite resonators is not the electromagnetic-wave density
of the energy and not the exchange energy density as well. This fact reveals
very special behaviors of the geometrical effects. Compared to other
geometries, thin-film ferrite disk resonators exhibit very unique interactions
of MS oscillations with the cavity electromagnetic fields. MS modes in a flat
ferrite disk are characterized by a complete discrete spectrum of energy
levels. The staircase demagnetization energy in thin-film ferrite disks may
appear as noticeable resonant absorption of electromagnetic radiation. Our
experiments show how the environment may cause decoherence for magnetic
oscillations. Another noticeable fact is experimental evidence for
eigen-electric-moment oscillations in a ferrite disk resonator.",0409583v2
2004-11-23,Impact of the inherent periodic structure on the effective medium description of left-handed and related meta-materials,"We study the frequency dependence of the effective electromagnetic parameters
of left-handed and related meta-materials of the split ring resonator and wire
type. We show that the reduced translational symmetry (periodic structure)
inherent to these meta-materials influences their effective electromagnetic
response. To anticipate this periodicity, we formulate a periodic effective
medium model which enables us to distinguish the resonant behavior of
electromagnetic parameters from effects of the periodicity of the structure. We
use this model for the analysis of numerical data for the transmission and
reflection of periodic arrays of split ring resonators, thin metallic wires,
cut wires as well as the left-handed structures. The present method enables us
to identify the origin of the previously observed resonance/anti-resonance
coupling as well as the occurrence of negative imaginary parts in the effective
permittivities and permeabilities of those materials. Our analysis shows that
the periodicity of the structure can be neglected only for the wavelength of
the electromagnetic wave larger than 30 space periods of the investigated
structure.",0411590v1
2004-12-02,Observation of Feshbach resonances in an ultracold gas of ${}^{52}$Cr,"We have observed Feshbach resonances in elastic collisions between ultracold
${}^{52}$Cr atoms. This is the first observation of collisional Feshbach
resonances in an atomic species with more than one valence electron. The zero
nuclear spin of ${}^{52}$Cr and thus the absence of a Fermi-contact interaction
leads to regularly-spaced resonance sequences. By comparing resonance positions
with multi-channel scattering calculations we determine the s-wave scattering
length of the lowest $^{2S+1}\Sigma_{g}^{+}$ potentials to be
$\unit[112(14)]{a_0}$, $\unit[58(6)]{a_0}$ and $-\unit[7(20)]{a_0}$ for S=6, 4,
and 2, respectively, where $a_{0}=\unit[0.0529]{nm}$.",0412049v2
2004-12-05,Multi-photon resonances in pure multiple-pulse NQR,"We have observed multi-photon resonances in a system with a spin 3/2
irradiated simultaneously by a multiple pulse radiofrequency sequence and a low
frequency field swept in the range 0-80 kHz. The used excitation scheme allowed
us to measure the effective field of the radiofrequency sequence. A peculiarity
of this scheme is that the intensity of the resonance lines decreases slowly
with the mode number. The theoretical description of the effect is presented
using both the rotating frame approximation and the Floquet theory. Both
approaches give indentical results at the calculation of the resonance
frequencies, transition probabilities and shifts of resonance frequency. The
calculated magnetization vs. the frequency of the low-frequency field agrees
well with the obtained experimental data. The multi-frequency spectra give a
way for studying slow atomic motion in solids.",0412106v1
2004-12-15,Resonant scattering properties close to a p-wave Feshbach resonance,"We present a semi-analytical treatment of both the elastic and inelastic
collisional properties near a p-wave Feshbach resonance. Our model is based on
a simple three channel system that reproduces more elaborate coupled-channel
calculations. We stress the main differences between s-wave and p-wave
scattering. We show in particular that, for elastic and inelastic scattering
close to a p-wave Feshbach resonance, resonant processes dominate over the
low-energy behaviour.",0412393v2
2004-12-16,Non-universal BCS-BEC crossover in resonantly interacting Fermi gases,"We investigate the non-universal behavior of the BCS-BEC crossover model at
the normal to superfluid transition. By using a finite temperature quantum
field theoretical approach due to Nozieres and Schmitt-Rink and by making the
effective range expansion of the effective two-body interaction we numerically
calculate the crossover transition temperature as a function of the scattering
length, $a_{F},$ and the effective range parameter, $r_{\mathrm{e}}.$ In an
ultracold two-component atomic Fermi gas BCS-BEC crossover physics is expected
to appear near magnetic-field-induced Feshbach resonances. By matching two-body
scattering properties near a Feshbach resonance to a simple renormalized model
potential, a broad resonance is characterized by a small effective range and
the gas displays a universal BCS-BEC crossover behavior. On the other hand, for
a narrow resonance thermodynamic quantities depend the effective range which
may be large and negative at resonance. For increasing values of
$-r_{\mathrm{e}}$ we find the transition temperature to be suppressed in the
crossover region. We furthermore argue for existence of a lower bound of
$T_{c}$ at fixed coupling for increasing $-r_{\mathrm{e}}$ in the crossover
region.",0412431v1
2004-12-25,Perturbation of finite-lattice spectral levels by nearby nuclear resonances,"We consider finite linear or cyclic crystalline structures with molecular
cells having narrow pre-threshold nuclear resonance. We prove that if the real
part of such a nuclear resonance lies within the energy band (the convex hull
of the energy levels) of the crystalline structure arising of a separated
molecular level, then there exist molecular crystalline states that decay
exponentially in time and the decay rate $\Gamma_R^{(m)}$ of these states in
the main order is described by the formula $\Gamma_R^{(m)}\cong
4\frac{\mathop{\rm Re} a}{\Gamma_R^{(n)}}$ where $a$ is the value of the
residue of the molecular channel transfer function at the nuclear resonance
point and $\Gamma_R^{(n)}$ is the nuclear resonance width.",0412687v1
2005-04-22,Unexpected Nonlinear Dynamics in NbN Superconducting Microwave Resonators,"In this work we characterize the unusual nonlinear dynamics of the resonance
response, exhibited by our NbN superconducting microwave resonators, using
different operating conditions. The nonlinear dynamics, occurring at relatively
low input powers (2-4 orders of magnitude lower than Nb), and which include
among others, bifurcations in the resonance curve, hysteresis loops and
resonance frequency shift, are measured herein using varying temperature,
applied magnetic field, white noise and rapid frequency sweeps. Based on these
measurement results, we consider a hypothesis according to which Josephson
junctions forming weak links at the boundaries of the NbN grains are
responsible for the observed behavior, and we show that most of the
experimental results are qualitatively consistent with such hypothesis.",0504582v1
2005-05-24,A self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition,"A self-consistent theory is derived to describe the BCS-BEC crossover for a
strongly interacting Fermi gas with a Feshbach resonance. In the theory the
fluctuation of the dressed molecules, consisting of both preformed Cooper-pairs
and ``bare'' Feshbach molecules, has been included within a self-consistent
$T$-matrix approximation, beyond the Nozi\`{e}res and Schmitt-Rink strategy
considered by Ohashi and Griffin. The resulting self-consistent equations are
solved numerically to investigate the normal state properties of the crossover
at various resonance widths. It is found that the superfluid transition
temperature $T_c$ increases monotonically at all widths as the effective
interaction between atoms becomes more attractive. Furthermore, a residue
factor $Z_m$ of the molecule's Green function and a complex effective mass have
been determined, to characterize the fraction and lifetime of Feshbach
molecules at $T_c$. Our many-body calculations of $Z_m$ agree qualitatively
well with the recent measurments on the gas of $^6$Li atoms near the broad
resonance at 834 Gauss. The crossover from narrow to broad resonances has also
been studied.",0505572v2
2006-02-16,Ferromagnetic resonance in systems with competing uniaxial and cubic anisotropies,"We develop a model for ferromagnetic resonance in systems with competing
uniaxial and cubic anisotropies. This model applies to (i) magnetic materials
with both uniaxial and cubic anisotropies, and (ii) magnetic nanoparticles with
effective core and surface anisotropies; We numerically compute the resonance
frequency as a function of the field and the resonance field as a function of
the direction of the applied field for an arbitrary ratio of cubic-to-uniaxial
anisotropy. We also provide some approximate analytical expressions in the case
of weak cubic anisotropy. We propose a method that uses these expressions for
estimating the uniaxial and cubic anisotropy constants, and for determining the
relative orientation of the cubic anisotropy axes with respect to the crystal
principle axes. This method is applicable to the analysis of experimental data
of resonance type measurements for which we give a worked example of an iron
thin film with mixed anisotropy.",0602369v3
2006-03-27,Regulating entanglement production in multitrap Bose-Einstein condensates,"A system of traps is considered, each containing a large number of
Bose-condensed atoms. This ensemble of traps is subject to the action of an
external modulating field generating nonequilibrium nonground-state
condensates. When the frequency of the modulating field is in resonance with
the transition frequency between two different topological coherent modes, each
trap becomes an analog of a finite-level resonant atom. Similarly to the case
of atoms in an electromagnetic resonant field, one can create entanglement
between atomic traps subject to a common resonant modulating field generating
higher coherent modes in each of the traps. A method is suggested for
regulating entanglement production in such a system of multitrap and multimode
Bose-Einstein condensates coupled through a common resonant modulating field.
Several regimes of evolutional entanglement production, regulated by
manipulating the external field, are illustrated by numerical calculations.",0603710v1
2006-06-02,Tunable Resonant Raman Scattering from Singly Resonant Single Wall Carbon Nanotubes,"We perform tunable resonant Raman scattering on 17 semiconducting and 7
metallic singly resonant single wall carbon nanotubes. The measured scattering
cross-section as a function laser energy provides information about a tube's
electronic structure, the lifetime of intermediate states involved in the
scattering process and also energies of zone center optical phonons. Recording
the scattered Raman signal as a function of tube location in the microscope
focal plane allows us to construct two-dimensional spatial maps of singly
resonant tubes. We also describe a spectral nanoscale artifact we have coined
the ""nano-slit effect"".",0606047v1
2006-06-19,A photonic bandgap resonator to facilitate GHz frequency conductivity experiments in pulsed magnetic fields,"We describe instrumentation designed to perform millimeter-wave conductivity
measurements in pulsed high magnetic fields at low temperatures. The main
component of this system is an entirely non-metallic microwave resonator. The
resonator utilizes periodic dielectric arrays (photonic bandgap structures) to
confine the radiation, such that the resonant modes have a high Q-factor, and
the system possesses sufficient sensitivity to measure small samples within the
duration of a magnet pulse. As well as measuring the sample conductivity to
probe orbital physics in metallic systems, this technique can detect the sample
permittivity and permeability allowing measurement of spin physics in
insulating systems. We demonstrate the system performance in pulsed magnetic
fields with both electron paramagnetic resonance experiments and conductivity
measurements of correlated electron systems.",0606476v1
2006-09-22,Nonlinear resonant behavior of the dispersive readout scheme for a superconducting flux qubit,"A nonlinear resonant circuit comprising a SQUID magnetometer and a parallel
capacitor is studied as a readout scheme for a persistent-current (PC) qubit.
The flux state of the qubit is detected as a change in the Josephson inductance
of the SQUID magnetometer, which in turn mediates a shift in the resonance
frequency of the readout circuit. The nonlinearity and resulting hysteresis in
the resonant behavior are characterized as a function of the power of both the
input drive and the associated resonance peak response. Numerical simulations
based on a phenomenological circuit model are presented which display the
features of the observed nonlinearity.",0609561v1
2006-12-12,Electric-Field-Induced Resonant Spin Polarization in a Two-Dimensional Electron Gas,"Electric response of spin polarization in two-dimensional electron gas with
structural inversion asymmetry subjected to a magnetic field was studied by
means of the linear and non-linear theory and numerical simulation with the
disorder effect. It was found by Kubo linear reponse theory that an electric
resonant response of spin polarization occurs when the Fermi surface is located
near the crossing of two Landau levels, which is induced from the competition
between the spin-orbit coupling and Zeeman splitting. The scaling behavior was
investigated with a simplified two-level model by non-linear method, and the
resonant peak value is reciprocally proportional to the electric field at low
temperatures and to temperature for finite electric fields. Finally numerical
simulation illustrated that impurity potential opens an enegy gap near the
resonant point and suppresses the effect gradually with the increasing strength
of disorder. This resonant effect may provide an efficient way to control spin
polarization by an external electric field.",0612277v2
2007-01-14,Sr1.5Ba0.5Zn2Fe12O22 Hexaferrites Ferromagnetic Resonance and Nonlinear Excitation for Magneto-Electric Devices,"A magneto electric (ME) effect was reported [1] for the insulator material of
helimagnetic hexaferrite of Sr1.5Ba0.5Zn2Fe12O22. In this study we are
interested in investigating this materials ferromagnetic resonance to define
its internal anisotropy fields. By using a vibrating sample magnetometer (VSM)
and ferromagnetic resonance (FMR) analysis we realized that this helical
hexaferrite has about -0.5 kOe exchange anisotropy field of HE. Also, by using
an alternative free energy model we derived this materials Polder tensor and
its ferromagnetic resonance condition. Meanwhile, we were able to show a
potential magneto electric coupling by nonlinear excitation of planar helical
hexaferrite, in which a magnetic nonlinear excitation is integrated into
dielectric permittivity.
  Index Terms, Ferrites, ferromagnetic resonances, and magnetic nonlinear
excitations.",0701309v2
2007-02-27,Nuclear Magnetic Resonance Imaging with 90 nm Resolution,"Magnetic resonance imaging, based on the manipulation and detection of
nuclear spins, is a powerful imaging technique that typically operates on the
scale of millimeters to microns. Using magnetic resonance force microscopy, we
have demonstrated that magnetic resonance imaging of nuclear spins can be
extended to a spatial resolution better than 100 nm. The two-dimensional
imaging of 19F nuclei was done on a patterned CaF2 test object, and was enabled
by a detection sensitivity of roughly 1200 nuclear spins. To achieve this
sensitivity, we developed high-moment magnetic tips that produced field
gradients up to 1.4x10^6 T/m, and implemented a measurement protocol based on
force-gradient detection of naturally occurring spin fluctuations. The
resulting detection volume of less than 650 zl represents 60,000x smaller
volume than previous NMR microscopy and demonstrates the feasibility of pushing
magnetic resonance imaging into the nanoscale regime.",0702664v1
2007-03-27,Resonance Microwave Absorption in He II.,"Microwave (MW) absorption in liquid 4He is investigated in the frequency
range of 40-200 GHz at T = 1.4 - 2.5 K. Whispering gallery of waves was
generated by a dielectric disc resonator immersed into the liquid. Resonance
absorption of MWs was detected at 180.3 GHz, which corresponds to the roton
minimum of the liquid helium excitation spectrum. The creation of a single
roton is possible because of the presence of the resonator wall which absorbs
an extra momentum. The resonance frequency is shown to decreases with
temperature in an excellent agreement with the temperature dependence of the
roton gap obtained previously in the neutron scattering experiment. The
temperature dependence of the MW absorption data indicates the anomalous
behavior near the lambda-point and displays the hysteretic character.",0703710v1
1999-07-16,Detection strategies for scalar gravitational waves with interferometers and resonant spheres,"We compute the response and the angular pattern function of an interferometer
for a scalar component of gravitational radiation in Brans-Dicke theory. We
examine the problem of detecting a stochastic background of scalar GWs and
compute the scalar overlap reduction function in the correlation between an
interferometer and the monopole mode of a resonant sphere. While the
correlation between two interferometers is maximized taking them as close as
possible, the interferometer-sphere correlation is maximized at a finite value
of f*d, where `f' is the resonance frequency of the sphere and `d' the distance
between the detectors. This defines an optimal resonance frequency of the
sphere as a function of the distance. For the correlation between the Virgo
interferometer located near Pisa and a sphere located in Frascati, near Rome,
we find an optimal resonance frequency f=590 Hz. We also briefly discuss the
difficulties in applying this analysis to the dilaton and moduli fields
predicted by string theory.",9907055v2
1999-11-30,Sustained resonance: a binary system perturbed by gravitational radiation,"The general phenomena associated with sustained resonance are studied in this
paper in connection with relativistic binary pulsars. We represent such a
system by two point masses in a Keplerian binary system that evolves via
gravitational radiation damping as well as an external tidal perturbation. For
further simplification, we assume that the external tidal perturbation is
caused by a normally incident circularly polarized monochromatic gravitational
wave. In this case, the second-order partially averaged equations are studied
and a theorem of C. Robinson is employed to prove that for certain values of
the physical parameters resonance capture followed by sustained resonance is
possible in the averaged system. We conjecture that sustained resonance can
occur in the physical system when the perturbing influences nearly balance each
other.",9911123v1
2001-11-23,First Measurement of the Double Spin Asymmetry in $\vec{e}\vec{p}\to e' π^+ n$ in the Resonance Region,"The double spin asymmetry in the $\vec{e}\vec{p}\to e' \pi^+ n$ reaction has
been measured for the first time in the resonance region for four-momentum
transfer $Q^2=0.35-1.5$ GeV$^2$. Data were taken at Jefferson Lab with the CLAS
detector using a 2.6 GeV polarized electron beam incident on a polarized solid
NH$_3$ target. Comparison with predictions of phenomenological models shows
strong sensitivity to resonance contributions. Helicity-1/2 transitions are
found to be dominant in the second and third resonance regions. The measured
asymmetry is consistent with a faster rise with $Q^2$ of the helicity asymmetry
$A_1$ for the $F_{15}(1680)$ resonance than expected from the analysis of the
unpolarized data.",0111074v2
2003-01-14,Evidence for Narrow S=+1 Baryon Resonance in Photo-production from Neutron,"The gamma n -> K+ K- n reaction on 12C has been studied by measuring both K+
and K- at forward angles. A sharp baryon resonance peak was observed at 1.54 +-
0.01 GeV with a width smaller than 25 MeV and a Gaussian significance of 4.6
sigma. The strangeness quantum number (S) of the baryon resonance is +1. It can
be interpreted as a molecular meson-baryon resonance or alternatively as an
exotic 5-quark state (uudd{s_bar}) that decays into a K+ and a neutron. The
resonance is consistent with the lowest member of an anti-decuplet of baryons
predicted by the chiral soliton model.",0301020v2
2004-08-18,"Measurements of Branching Fraction, Polarization, and Direct-CP-Violating Charge Asymmetry in B+ --> K*0 Rho+ Decays","With a sample of 88.8 BBbar pairs produced at PEP-II in e+e- annihilation
through the Upsilon(4S) resonance and recorded with the BABAR detector, we
search for the B+ --> K*0 Rho+ decay mode. A signal is observed for the first
time with a significance of more than 5 sigma. We measure a preliminary
branching fraction of BR(B+ --> K*0 Rho+)=[17.0 +-2.9 (stat) +-2.0 (syst) +0.0
-1.9 (non-resonant)] 10(-6). The ""non-resonant"" error corresponds to the
uncertainty from non-resonant backgrounds not modeled in the fit. The
measurement of the longitudinal-polarized component to this vector-vector
penguin decay is of special interest. We measure fL= 0.79 +-0.08(stat) +-0.04
(syst) +- 0.02 (non-resonant). We measure the direct-CP-violating charge
asymmetry in this mode to be A_CP = -0.14 +- 0.17 +- 0.04.",0408093v2
2006-02-28,Search for a new Resonance decaying into Top-Antitop at Tevatron,"In this report a new search for a narrow-width heavy resonance decaying into
top quark pairs (X -> ttbar) in ppbar collisions at sqrt(s)=1.96 TeV has been
performed using data collected by the D0 detector at the Fermilab Tevatron
collider. The analysis considers ttbar candidate events in the lepton+jets
channel using a lifetime tag to identify b-jets and the ttbar invariant mass
distribution to search for evidence of resonant production. The analyzed
dataset corresponds to an integrated luminosity of approximately 370 pb^-1.
Since no evidence for a ttbar resonance X is found, upper limits on sigma(X) x
B(X -> ttbar) for different hypothesized resonance masses using a Bayesian
approach are set. Within a topcolor-assisted technicolor model, the existence
of a leptophobic Z' boson with M(Z') < 680 GeV and width Gamma(Z') = 0.012
M(Z') can be excluded at 95% C.L..",0602048v1
2006-06-08,Search for a heavy resonance decaying into a Z+jet final state in p-pbar collisions at sqrt(s) = 1.96 TeV using the D0 detector,"We have searched for a heavy resonance decaying into a Z+jet final state in
p-pbar collisions at a center of mass energy of 1.96 TeV at the Fermilab
Tevatron collider using the D0 detector. No indication for such a resonance was
found in a data sample corresponding to an integrated luminosity of 370/pb. We
set upper limits on the cross section times branching fraction for heavy
resonance production at the 95% C.L. as a function of the resonance mass and
width. The limits are interpreted within the framework of a specific model of
excited quark production.",0606018v1
1995-09-26,Resonance Scattering on the Lattice with Non-Zero Total Momentum,"Most hadronic particles are resonances: for example, the rho meson appears as
a resonance in the elastic scattering of two pions. A method by Luescher
enables one to measure the properties of the resonance particles from finite
lattices. We present here a more general method which includes scattering
processes where the total momentum of the particles is non-zero. The main
advantage is that the resonance scattering can be observed in a considerably
smaller spatial volume. We test the method with a simple 3+1 dimensional spin
model, and find excellent agreement between the zero momentum and the non-zero
momentum scattering sectors.",9509088v1
1994-02-17,On The $Q^2$ Dependence of The Spin Structure Function In The Resonance Region,"In this paper, we show what we can learn from the CEBAF experiments on
spin-structure functions, and the transition from the Drell-Hearn-Gerasimov sum
rule in the real photon limit to the spin dependent sum rules in the deep
inelastic scattering, and how the asymmetry $A_1(x,Q^2)$ approaches the scaling
limit in the resonance region. The spin structure function in the resonance
region alone can not determine the spin-dependent sum rule due to the kinematic
restriction of the resonance region. The integral $\int_0^1 \frac
{A_1(x,Q^2)F_2(x,Q^2)}{2x(1+R(x,Q^2))}dx$ is estimated from $Q^2=0$ to $2.5$
GeV$^2$. The result shows that there is a region where both contributions from
the baryon resonances and the deep inelastic scattering are important, thus
provides important information on the high twist effects on the spin dependent
sum rule.",9402308v1
1995-07-31,Dilepton production from resonance scattering in hot hadronic matter,"Dilepton production from resonance scattering in hot hadronic matter is
studied. Including the widths of these resonances, which enhance the phase
space for dilepton production, we find that the production rate is
significantly increased if a resonance appears in the extended phase space. For
the reaction $\pi+\rho\to l^++l^-$, the finite $\rho$ meson width extends the
invariant mass below the $\omega$-meson mass, so a peak at the $\omega$ meson
mass is seen in the dilepton spectrum. Similarly, a $\rho$-meson peak appears
in the reaction $\rho+\rho\to l^++l^-$. On the other hand, the effect of
particle widths in the reaction $\pi+a_1\to l^++l^-$ is small since the
extended phase space does not include any resonance.",9507458v1
1995-09-08,Effective Chiral Lagrangian from Dual Resonance Models,"Parameters of the effective chiral lagrangian (EChL) of orders $O(p^4)$ and
$O(p^6)$ are extracted from low--energy behaviour of dual resonance models for
$ \pi\pi$ and $\pi K$ scattering amplitudes. Dual resonance models are
considered to be good candidates for the resonance spectrum and for hadronic
scattering amplitudes in the large $N_c$ limit of QCD. We discuss dual
resonance models in the presence of spontaneous and explicit chiral symmetry
breaking. Obtained parameters of the EChL are used to estimate chiral
corrections up to the sixth order to various low--energy characteristics of
$\pi\pi$ and $\pi K$ scattering amplitudes.",9509259v2
1995-12-21,A New Type of Resonant Neutrino Conversions Induced by Magnetic Fields,"We consider resonant neutrino conversions in magnetised matter, such as a
degenerate electron gas. We show how magnetisation effects caused by axial
vector interactions of neutrinos with the charged leptons in the medium can
induce a new type of resonant neutrino conversion which may occur even in
situations where the MSW effect does not occur, such as the case of degenerate
or inverted neutrino mass spectra. Our new resonance may simultaneously affect
anti-neutrino $\bar{\nu_a} \leftrightarrow \bar{\nu}_b$ as well as neutrino
$\nu_{a} \leftrightarrow \nu_b$ flavour conversions, and therefore it may
substantially affect supernova neutrino energy spectra. Using SN1987A data we
conclude that only laboratory experiments with long baseline such as ICARUS or
MINOS are likely to find neutrino oscillations due to their sensitivity to
small $\Delta m^2$. We also comment on the possibility of resonant conversions
induced by Majorana neutrino transition moments and mention the case of sterile
neutrinos $\nu_s$.",9512390v1
1997-04-29,A Phenomenological Analysis of Non-resonant Charm Meson Decays,"We analyse the consequences of the usual assumption of a constant function to
fit non-resonant decays from experimental Dalitz plot describing charmed meson
decays. We first show, using the $D^+\to \bar{K}^0\pi^+\pi^0$ decay channel as
an example, how an inadequate extraction of the non-resonant contribution could
yield incorrect measurements for the resonant channels. We analyse how the
correct study of this decay will provide a test for the validity of
factorization in D meson decays. Finally, we show how form factors could be
extracted from non-resonant decays. We particularly discuss about the form
factor that can be measured from the $D^+_s\to \pi^-\pi^+\pi^+$ decay. We
emphasize on its relevance for the study of the decay $\tau \to \nu_{\tau}
3\pi$ and the extraction of the $a_1$ meson width.",9704437v1
1997-05-27,Quark-antiquark resonances in the NJL model,"The problem of the $\rho$ meson resonance solution in the extended NJL model
is studied. It has been shown previously that the solution for the $\rho$ meson
changes smoothly from a bound state to a ""virtual state"" when the vector
channel attraction becomes too weak to support bound state solutions. We have
found that together with these solutions a separate resonance branch appears
which is not connected smoothly with the bound state solutions. At small values
of constituent quark mass, $m\sim 200$ MeV, it corresponds to the physical
vector meson resonance solution in the quark-continuum region. The $a_1$ and
$\sigma$ resonances are also discussed.",9705438v1
1997-06-24,Theoretical Study of the γγ-->meson-meson Reaction,"We present a unified picture which studies simultaneously the gamma
gamma-->pi^+ pi^-, pi^0 pi^0, K^+ K^-, K^0 bar{K}^0, pi^0 eta reactions up to
about sqrt(s)=1.4 GeV reproducing the experimental cross sections. The present
work implements in an accurate way the final state interactions of the
meson-meson system, which is shown to be essential in order to reproduce the
data, particularly the L=0 channel. This latter channel is treated here
following a recent theoretical work in which the meson-meson amplitudes are
well reproduced and the f_0, a_0, sigma resonances show up clearly as poles of
the t matrix. The present work, as done in earlier ones, also incorporates
elements of chiral symmetry and exchange of vector and axial resonances in the
crossed channels, as well as a direct coupling to the f_2(1270) and a_2(1320)
resonances. We also evaluate the decay width of the f_0(980) and a_0(980)
resonances into the gamma-gamma channel.",9706487v2
1997-11-29,Direct CP violation in three-body decays of the $B$ meson by resonance effects,"We discuss direct CP violation in three-body decays of $B$ meson such as
$B^\pm \to K^\pm\pi^+\pi^-$, which involves various intermediate resonance
states, such as $B^\pm \to K^*_i \pi^\pm$ and $B^\pm \to \rho K^\pm$, where
$K^*_i$ represents the $\pi K$ resonance. Due to the large final state
interaction phases of the resonances, the CP asymmetry can be as large as the
25% level near the kinematical region where the $K^*_i$ and $\rho$ resonances
overlap. By examining a Dalitz plot of this mode and combining a measurement of
the branching ratio for $B^\pm \to \rho^\pm K$, it is possible to extract the
weak phase, $\phi_3$= arg$(-V_{ud}V_{ub}^*/(V_{cd}V_{cb}^*))$, of the
Kobayashi-Maskawa matrix.",9712202v2
1999-10-21,Probing Planckian physics: resonant production of particles during inflation and features in the primordial power spectrum,"The phenomenon of resonant production of particles {\it after} inflation has
received much attention in the past few years. In a new application of resonant
production of particles, we consider the effect of a resonance {\em during}
inflation. We show that if the inflaton is coupled to a massive particle,
resonant production of the particle during inflation modifies the evolution of
the inflaton, and may leave an imprint in the form of sharp features in the
primordial power spectrum. Precision measurements of microwave background
anisotropies and large-scale structure surveys could be sensitive to the
features, and probe the spectrum of particles as massive as the Planck scale.",9910437v1
2000-06-09,Exclusive Hadronic D Decays to $η'$ or $η$: Addendum on Resonant Final-State Interactions,"For hadronic two-body decays of charmed mesons involving $\eta$ or $\eta'$,
resonance-induced final-state interactions (FSI) that mimic the W-exchange or
the W-annihilation topology can play an essential role. In particular, the
decays $D^0\to\bar K^0\eta'$ and $D^+\to\pi^+\eta$, which are largely
suppressed in the absence of FSI, are enhanced dramatically by resonant FSI. It
is stressed that the effect of resonant FSI is negligible for
$\rho^+(\eta,\eta')$ final states because of the mismatch of the G parity of
$\rho^+(\eta,\eta')$ and the J=0, I=1 meson resonance. We argue that a possible
gluon-mediated process in which two gluons couple directly to the gluonic
component of the $\eta'$, e.g. the gluonium, rather than to the flavor-singlet
$\eta_0$, can enhance both modes $D_s^+\to\rho^+\eta'$ and
$D_s^+\to\rho^+\eta$, especially the former; that is, this new mechanism can
account for the unexpectedly large branching ratio of $\rho^+\eta'$ without
suppressing $\rho^+\eta$.",0006081v1
2002-11-08,Matter-induced modification of resonances at RHIC freezeout,"We discuss the physical effects causing a modification of resonance masses,
widths and even shapes in a dilute hadronic gas at late stages of heavy ion
collisions. We quantify the conditions at which resonances are produced at
RHIC, and found that it happens at $T\approx 120 MeV$. Although in the pp case
the ``kinematic'' effects like thermal weighting of the states is sufficient,
in AA we see a clear effect of dynamical interaction with matter, both due to a
variety of s-channel resonances and due to t-channel scalar exchanges. The
particular quantity we focus mostly on is the $\rho$ meson mass, for which
these dynamical effects lead to about -50 MeV shift, on top of about -20 MeV of
a thermal effect: both agree well with preliminary data from STAR experiment at
RHIC. We also predict a complete change of shape of $f_0(600)$ resonance, even
by thermal effects alone.",0211119v2
2003-07-01,Recent progress on the light meson resonance description from unitarized Chiral Perturbation Theory and large Nc,"We present a brief account of the developments in the description of light
meson resonances using unitarized extensions of the Chiral Perturbation Theory
series, both in energy and temperature. In particular, we describe how these
methods have been recently shown to describe simultaneously the low energy and
resonance regions of meson-meson scattering. This approach could be of
relevance to understand the light scalar mesons since it provides a formalism
that respects chiral symmetry and unitarity and is able to generate resonant
states without any a priori theoretical bias toward their existence,
classification or spectroscopic nature. We will also review how this approach
is also able to describe the thermal evolution of the $\rho$ and $\sigma$
mesons. In addition we review their extensions to higher orders, the most
recent determination of the resonance pole properties, as well as their
behavior in the large $N_c$ limit, which could be of relevance to understand
their spectroscopic nature.",0307018v1
2003-07-09,Time delayed K+ N reactions and exotic baryon resonances,"Evidences and hints, both from the theoretical and experimental side, of
exotic baryon resonances with B=S, have been with us for the last thirty years.
The poor status of the general acceptance of these Z* resonances is partly due
to the prejudice against penta-quark baryons and partly due to the opinion that
a proof of the existence of exotic states must be rigorous. This can refer to
the quality and amount of data gathered, and also to the analytical methods
applied in the study of these resonances. It seems then mandatory that all
possibilities and aspects be exploited. We do that by analyzing the time delay
in K+ N scattering, encountering clear signals of the exotic Z* resonances
close to the pole values found in partial wave analyses.",0307134v2
2003-08-12,Neutrino Production of Resonances,"We take a fresh look at the analysis of resonance production by neutrinos. We
consider three resonances $P_{33}, P_{11}$ and $S_{11}$ with a detailed
discussion of their form factors. The article presents results for free proton
and neutron targets and discusses the corrections which appear on nuclear
targets. The Pauli suppression factor is derived in the Fermi gas model and
shown to apply to resonance production. The importance of the various
resonances is demonstrated with numerical calculations. The $\Delta$-resonance
is described by two formfactors and its differential cross sections are
compared with experimental data. The article is self-contained and could be
helpful to readers who wish to reproduce and use these cross sections.",0308130v1
2003-10-01,Pentaquark as Kaon-Nucleon Resonance,"Several recent experiments have reported evidence for a narrow feature in the
K(+)-neutron system, an apparent resonant state ~ 100 MeV above threshold and
with a width < 25 MeV. This state has been labelled as Theta(+) (previously as
Z(*)), and because of the implied inclusion of a anti-strange quark, is
referred to as a pentaquark, that is, five quarks within a single bag. We
present an alternative explanation for such a structure, as a higher angular
momentum resonance in the isospin zero K(+) -N system. One might call this an
exit channel or a molecular resonance. In a non-relativistic potential model we
find a possible candidate for the kaon-nucleon system with relative angular
momentum L=3, while L=1 and 2 states possess centrifugal barriers too low to
confine the kaon and nucleon in a narrow state at an energy so high above
threshold. A rather strong state-dependence in the potential is essential,
however, for eliminating an observable L=2 resonance at lower energies.",0310026v1
2003-12-05,Nonperturbative scalar-meson resonances with open charm and beauty,"We predict several new bound states and resonances for B-pion, B-Kaon, and
B-D S-wave elastic scattering, within the same model which was recently
employed to explain the D*sJ(2317)+ meson. In the charm-nonstrange sector we
find a (virtual ?) bound state close to the B-pion threshold, and moreover two
nearby resonances of comparable width in the range 5.9 to 6.1 GeV. We obtain
bound states B*s0(5570) in b-sbar and B*c0(6490) in bbar-c, as well as
resonances at higher energies. No JP=0+ states are found at 5.6 GeV (in
bbar-u/d), at 5.7 GeV (in b-sbar), or at 6.1 GeV (in bbar-c), where they are
predicted from pure confinement.",0312078v1
2004-05-07,CP violation in the partial width asymmetries for B^- -> pi^+ pi^- K^- and B^- -> K^+ K^- K^- decays,"We investigate a possibility of observing CP asymmetries in the partial
widths for the decays B^- -> pi^+ pi^- K^- and B^- -> K^+ K^- K^- produced by
the interference of the non-resonant decay amplitude with the resonant
amplitudes. The resonant states which subsequently decay into pi^+ pi^- and K^+
K^- or K^- pi^+ are charmonium c(bar) c states with J^P = 0^+, 1^-, 1^+ or the
phi(1020) meson. We find that the largest partial width asymmetry comes from
the chi_c0 resonance, while the resonances K^*_0(1430) and psi(2S) give a
partial width asymmetry of the order 10%.",0405065v2
2004-07-23,Multichannel calculation for Ds* vector states and the Ds(2632) resonance,"We study bound states below threshold and resonances above threshold in the
D0-K+ and Ds-eta systems, using a many-coupled-channel model for non-exotic
meson-meson scattering applied to states with the quantum numbers of c-sbar
quark-antiquark vector mesons. We fit the ground state at 2.112 GeV, whence the
lowest resonances in D0-K+ come out at 2.61, 2.72, 3.03, and 3.08 GeV. The
resonance at 2.61 GeV acquires a width of about 8 MeV, while its partial P-wave
cross section is up to six times larger in Ds-eta than in D0-K+, provided a
mechanism accounting for Okubo-Zweig-Iizuka--forbidden decays is included. The
latter finding is in agreement with the observations of the SELEX collaboration
with respect to the recently reported DsJ(2632) resonance. Therefore, we
conclude that the DsJ(2632) is most probably the first recurrence excitation of
the Ds*(2112) meson.",0407281v2
2004-08-17,Comparison of a new Delta resonance production model with electron and neutrino data,"We consider resonance production by neutrinos focusing on the dominant
resonance $P_{33}$ at low energies with a detailed discussion of its form
factors. The results are presented for free nucleon targets. The $\Delta$
resonance is described by two form factors $C_3^V$ and $C_5^A$ and its
differential cross sections are compared with experimental data. Further, we
apply this approach to the electroproduction case and calculate its
differential cross sections which are compared with electroproduction
experimental data. Our approach to the analysis of $\Delta$ resonance is
particularly simple and self-contained such that it could be helpful for the
physical interpretation.",0408185v1
2005-01-01,"Determination of the quarkonium--gluonium content of the isoscalar tensor resonances $f_2(1920)$, $f_2(2020)$, $f_2(2240)$, $f_2(2300)$ and of the broad state $f_2(2000)$ based on decay couplings to $π^0π^0,ηη,ηη'$","In the reactions $p\bar p\to\pi^0\pi^0,\eta\eta,\eta\eta'$ there are four
relatively narrow resonances $f_2(1920)$, $f_2(2020)$, $f_2(2240)$,
$f_2(2300)$, and a broad one $f_2(2000)$ in the mass region 1990--2400 MeV. In
the framework of quark combinatorics we carry out an analysis of the decay
constants for all five resonances. It is shown that the relations for the decay
constants corresponding to the broad resonance
$f_2(2000)\to\pi^0\pi^0,\eta\eta, \eta\eta'$ are the same as those
corresponding to a glueball. An additional argument in favour of the
glueball--nature of $f_2(2000)$ is the fact that $f_2(1920)$, $f_2(2020)$,
$f_2(2240)$, $f_2(2300)$ fit well the $q\bar q$ trajectories in the
$(n,M^2)$-plane (where $n$ is the radial quantum number), while the broad
$f_2(2000)$ resonance turns out to be an unnecessary extra state for these
trajectories.",0501003v1
2005-03-29,Low lying axial-vector mesons as dynamically generated resonances,"We make a theoretical study of the s-wave interaction of the nonet of vector
mesons with the octet of pseudoscalar mesons starting from a chiral invariant
Lagrangian and implementing unitarity in coupled channels. By looking for poles
in the unphysical Riemann sheets of the unitarized scattering amplitudes, we
get two octets and one singlet of axial-vector dynamically generated
resonances. The poles found can be associated to most of the low lying
axial-vector resonances quoted in the Particle Data Book: $b_1(1235)$,
$h_1(1170)$, $h_1(1380)$, $a_1(1260)$, $f_1(1285)$ and two poles to the
$K_1(1270)$ resonance. We evaluate the couplings of the resonances to the $VP$
states and the partial decay widths in order to reinforce the arguments in the
discussion.",0503273v2
2005-04-21,SU(3) Baryon Resonance Multiplets in Large N_c QCD,"We extend the recently developed treatment of baryon resonances in large N_c
QCD to describe resonance multiplets collected according to the SU(3) flavor
symmetry that includes strange quarks. As an illustration we enumerate the
SU(3) partners of a hypothetical J^P = 1/2^{+/-} resonance in the SU(3)
representation that reduces to 10-bar when N_c = 3, and reproduce results
hitherto obtained only in the context of a large N_c quark picture. While these
specific quantum numbers represent one favored set for the possible pentaquark
state Theta^+ (1540), the method is applicable to baryon resonances with any
quantum numbers.",0504200v1
2005-06-06,Shape of the $f_0(980)$ in $γγ\toπ^+π^-$,"The Belle Collaboration results on the observation of the $f_0(980)$
resonance in the reaction $\gamma\gamma\to\pi^+\pi^-$ are analyzed. It is
argued that they point to the presence of mechanisms which give rise to a
strong distortion of the $f_0(980)$ resonance shape in comparison with the
shape of a solitary Breit-Wigner resonance. It is shown that the main factors
responsible for the formation of the specific, steplike, shape of the
$f_0(980)$ resonance in the $\gamma\gamma\to\pi^+\pi^-$ reaction cross section
are the $K^+K^-$ loop mechanism of the $f_0(980)$ coupling to the
$\gamma\gamma$ system and the destructive interference between the background
and $f_0(980)$ resonance contributions in the $\pi^+\pi^-$ invariant mass
region below the $K^+K^-$ threshold.",0506046v2
2006-04-13,Tests of the naturalness of the coupling constants in ChPT at order p^6,"We derive constraints on combinations of O(p^6) chiral coupling constants by
matching a recent two-loop calculation of the pi-K scattering amplitude with a
set of sum rules. We examine the validity of the natural expectation that the
values of the chiral couplings can be associated with physics properties of the
light resonance sector. We focus, in particular, on flavour symmetry breaking
of vector resonances. A resonance chiral Lagrangian is constructed which
incorporates flavour symmetry breaking more completely than was done before. We
use pi-K unsubtracted sum rules as tests of the modelling of the resonance
contributions to the chiral couplings. In some cases the O(p^6) couplings are
found not to be dominated by the resonance contributions.",0604125v2
2007-03-23,Importance of the Mechanism of Resonance Enhancement of Neutrino Oscillations in Matter for the Precise Testing of the Electroweak Interaction Model. Present Experimental Status of This Resonance Mechanism,"The mechanism of resonance enhancement of neutrino oscillations in matter and
some critical remarks to this mechanism are considered. Using of this resonance
mechanism is very important to examine the model of electroweak interactions
since the processes induced by this mechanism grow multiply. In contrast to the
electromagnetic and strong interactions in weak interactions, $P$-parity is
violated therefore a problem of mass generations in the weak interactions is
considered (the interaction must be left-right symmetric for mass generations).
It is concluded that a possibility of mass generation in the framework of the
weak interactions is not proved. The present experimental status of this
resonance mechanism is considered and it is done conclusion that this effect
has no clear experimental confirmation. For this purpose it is necessary to
fulfil precision experiments with solar neutrinos and the neutrinos passed
through the Earth matter.",0703252v1
2000-02-21,Quasi-Localization of Gravity by Resonant Modes,"We examine the behaviour of gravity in brane theories with extra dimensions
in a non-factorizable geometry. We find that for metrics which are
asymptotically flat far from the brane there is a resonant graviton mode at
zero energy. The presence of this resonance ensures quasi-localization of
gravity, whereby at intermediate scales the gravitational laws on the brane are
approximately four dimensional. However, for scales larger than the lifetime of
the graviton resonance the five dimensional laws of gravity will be reproduced
due to the decay of the four dimensional graviton. We also present a simple
classification of the possible types of effective gravity theories on the brane
that can appear for general non-factorizable background theories.",0002161v2
2006-04-28,Resonance in Asymmetric Warped Geometry,"We study the spectrum of an asymmetric warped braneworld model with different
AdS curvatures on either side of the brane. In addition to the RS-like modes we
find a resonance state. Its mass is proportional to the geometric mean of the
two AdS curvature scales, while the difference between them determines the
strength of the resonance peak. There is a complementarity between the RS
zero-mode and the resonance: making the asymmetry stronger weakens the
zero-mode but strengthens the resonance, and vice versa. We calculate
numerically the braneworld gravitational potential and discuss the holographic
correspondence for the asymmetric model.",0604218v3
2005-08-29,The Lyapunov function for Schrödinger operators with a periodic 2x2 matrix potential,"We consider the Schr\""odinger operator on the real line with a 2x2 matrix
valued 1-periodic potential. The spectrum of this operator is absolutely
continuous and consists of intervals separated by gaps. We define a Lyapunov
function which is analytic on a two sheeted Riemann surface. On each sheet, the
Lyapunov function has the same properties as in the scalar case, but it has
branch points, which we call resonances. We prove the existence of real as well
as non-real resonances for specific potentials. We determine the asymptotics of
the periodic and anti-periodic spectrum and of the resonances at high energy.
We show that there exist two type of gaps: 1) stable gaps, where the endpoints
are periodic and anti-periodic eigenvalues, 2) unstable (resonance) gaps, where
the endpoints are resonances (i.e., real branch points of the Lyapunov
function). We also show that periodic and anti-periodic spectrum together
determine the spectrum of the matrix Hill operator.",0508567v1
2006-04-01,Schrödinger operators on zigzag graphs,"We consider the Schr\""odinger operator on zigzag graphs with a periodic
potential. The spectrum of this operator consists of an absolutely continuous
part (intervals separated by gaps) plus an infinite number of eigenvalues with
infinite multiplicity. We describe all compactly supported eigenfunctions with
the same eigenvalue. We define a Lyapunov function, which is analytic on some
Riemann surface. On each sheet, the Lyapunov function has the same properties
as in the scalar case, but it has branch points, which we call resonances. We
prove that all resonances are real. We determine the asymptotics of the
periodic and anti-periodic spectrum and of the resonances at high energy. We
show that there exist two types of gaps: i) stable gaps, where the endpoints
are periodic and anti-periodic eigenvalues, ii) unstable (resonance) gaps,
where the endpoints are resonances (i.e., real branch points of the Lyapunov
function). We obtain the following results from the inverse spectral theory: 1)
we describe all finite gap potentials, 2) the mapping: potential -- all
eigenvalues is a real analytic isomorphism for some class of potentials.
  We apply all these results to quasi-1D models of zigzag single-well carbon
nanotubes.",0604006v2
2006-10-20,Resonances and Spectral Shift Function for the semi-classical Dirac operator,"We consider the self-adjoint operator $H=H_0+V$, where $H_0$ is the free
semi-classical Dirac operator on $R^3$. We suppose that the smooth
matrix-valued potential $V=O(<x>^{-\delta}), \delta>0,$ has an analytic
continuation in a complex sector outside a compact. We define the resonances as
the eigenvalues of the non-selfadjoint operator obtained from the Dirac
operator $H$ by a complex distortions of $R^{3}$.We establish an upper bound
$O(h^{-3})$ for the number of resonances in any compact domain. For $\delta>3$,
a representation of the derivative of the spectral shift function
$\xi(\lambda,h)$ related to the semi-classical resonances of $H$ and a local
trace formula are obtained. In particular, if $V$ is an electro-magnetic
potential, we deduce a Weyl-type asymptotic of the spectral shift function. As
a by-product, we obtain an upper bound $O(h^{-2})$ for the number of resonances
close to non-critical energy levels in domains of width $h$ and a Breit-Wigner
approximation formula for the derivative of the spectral shift function.",0610622v1
2006-12-11,Spectral estimates for matrix-valued periodic Dirac operators,"We consider the first order periodic systems perturbed by a $2N\ts 2N$
matrix-valued periodic potential on the real line. The spectrum of this
operator is absolutely continuous and consists of intervals separated by gaps.
We define the Lyapunov function, which is analytic on an associated N-sheeted
Riemann surface. On each sheet the Lyapunov function has the standard
properties of the Lyapunov function for the scalar case. The Lyapunov function
has branch points, which we call resonances. We prove the existence of real or
complex resonances. We determine the asymptotics of the periodic, anti-periodic
spectrum and of the resonances at high energy (in terms of the Fourier
coefficients of the potential). We show that there exist two types of gaps: i)
stable gaps, i.e., the endpoints are periodic and anti-periodic eigenvalues,
ii) unstable (resonance) gaps, i.e., the endpoints are resonances (real branch
points). Moreover, we determine various new trace formulae for potentials and
the Lyapunov exponent.",0612285v1
2004-03-08,Studying resonance in the complex charge plane,"Potential resonances are usually investigated either directly in the complex
energy plane or indirectly in the complex angular momentum plane. Another
formulation complementing these two is presented in this work. It is an
indirect method which studies resonances in a complex charge plane (Z-plane).
The complex scaling (rotation) method is employed in the development of this
formulation. Bound states spectrum and resonance energies are mapped onto a
discrete set of poles of a resolvent operator on the real line of the Z-plane.
These poles move along trajectories as we vary the energy. A finite L2 basis is
used in the numerical implementation of the method. Stability of poles and
trajectories against variations in all computational parameters is
demonstrated. Resonances for a given potential example are calculated and
compared with those obtained elsewhere. In this presentation, modest effort
will be devoted to mathematical rigor.",0403010v1
2006-05-25,Fast Computation Algorithm for Discrete Resonances among Gravity Waves,"Traditionally resonant interactions among short waves, with large real
wave-numbers, were described statistically and only a small domain in spectral
space with integer wave-numbers, discrete resonances, had to be studied
separately in resonators. Numerical simulations of the last few years showed
unambiguously the existence of some discrete effects in the short-waves part of
the wave spectrum. Newly presented model of laminated turbulence explains
theoretically appearance of these effects thus putting a novel problem -
construction of fast algorithms for computation of solutions of resonance
conditions with integer wave-numbers of order $10^3$ and more. Example of such
an algorithm for 4-waves interactions of gravity waves is given. Its
generalization on the different types of waves is briefly discussed.",0605067v1
2001-05-21,Resonances of the Frobenius-Perron Operator for a Hamiltonian Map with a Mixed Phase Space,"Resonances of the (Frobenius-Perron) evolution operator P for phase-space
densities have recently attracted considerable attention, in the context of
interrelations between classical and quantum dynamics. We determine these
resonances as well as eigenvalues of P for Hamiltonian systems with a mixed
phase space, by truncating P to finite size in a Hilbert space of phase-space
functions and then diagonalizing. The corresponding eigenfunctions are
localized on unstable manifolds of hyperbolic periodic orbits for resonances
and on islands of regular motion for eigenvalues. Using information drawn from
the eigenfunctions we reproduce the resonances found by diagonalization through
a variant of the cycle expansion of periodic-orbit theory and as rates of
correlation decay.",0105047v1
2003-09-26,"Near-Resonant, Steady Mode Interaction: Periodic, Quasi-Periodic and Localized Patterns","Motivated by the rich variety of complex periodic and quasi-periodic patterns
found in systems such as two-frequency forced Faraday waves, we study the
interaction of two spatially periodic modes that are nearly resonant. Within
the framework of two coupled one-dimensional Ginzburg-Landau equations we
investigate analytically the stability of the periodic solutions to general
perturbations, including perturbations that do not respect the periodicity of
the pattern, and which may lead to quasi-periodic solutions. We study the
impact of the deviation from exact resonance on the destabilizing modes and on
the final states. In regimes in which the mode interaction leads to traveling
waves our numerical simulations reveal localized waves in which the wavenumbers
are resonant and which drift through a steady background pattern that has an
off-resonant wavenumber ratio.",0309070v2
2004-04-29,Resonant Interactions in Rotating Homogeneous Three-dimensional Turbulence,"Direct numerical simulations of three-dimensional (3D) homogeneous turbulence
under rapid rigid rotation are conducted to examine the predictions of resonant
wave theory for both small Rossby number and large Reynolds number. The
simulation results reveal that there is a clear inverse energy cascade to the
large scales, as predicted by 2D Navier-Stokes equations for resonant
interactions of slow modes. As the rotation rate increases, the
vertically-averaged horizontal velocity field from 3D Navier-Stokes converges
to the velocity field from 2D Navier-Stokes, as measured by the energy in their
difference field. Likewise, the vertically-averaged vertical velocity from 3D
Navier-Stokes converges to a solution of the 2D passive scalar equation. The
energy flux directly into small wave numbers in the $k_z=0$ plane from
non-resonant interactions decreases, while fast-mode energy concentrates closer
to that plane. The simulations are consistent with an increasingly dominant
role of resonant triads for more rapid rotation.",0404055v1
2004-10-27,Resonant nonlinearity management for nonlinear-Schrödinger solitons,"We consider effects of a periodic modulation of the nonlinearity coefficient
on fundamental and higher-order solitons in the one-dimensional NLS equation,
which is an issue of direct interest to Bose-Einstein condensates in the
context of the Feshbach-resonance control, and fiber-optic telecommunications
as concerns periodic compensation of the nonlinearity. We find from
simulations, and explain by means of a straightforward analysis, that the
response of a fundamental soliton to the weak perturbation is resonant, if the
modulation frequency $\omega $ is close to the intrinsic frequency of the
soliton. For higher-order $n$-solitons with $n=2$ and 3, the response to an
extremely weak perturbation is also resonant, if $\omega $ is close to the
corresponding intrinsic frequency. More importantly, a slightly stronger drive
splits the 2- or 3-soliton, respectively, into a set of two or three moving
fundamental solitons. The dependence of the threshold perturbation amplitude,
necessary for the splitting, on $\omega $ has a resonant character too.
Amplitudes and velocities of the emerging fundamental solitons are accurately
predicted, using exact and approximate conservation laws of the perturbed NLS
equation.",0410059v1
2007-03-26,Interactions of renormalized waves in thermalized Fermi-Pasta-Ulam chains,"The dispersive interacting waves in Fermi-Pasta-Ulam (FPU) chains of
particles in \textit{thermal equilibrium} are studied from both statistical and
wave resonance perspectives. It is shown that, even in a strongly nonlinear
regime, the chain in thermal equilibrium can be effectively described by a
system of weakly interacting \textit{renormalized} nonlinear waves that possess
(i) the Rayleigh-Jeans distribution and (ii) zero correlations between waves,
just as noninteracting free waves would. This renormalization is achieved
through a set of canonical transformations. The renormalized linear dispersion
of these renormalized waves is obtained and shown to be in excellent agreement
with numerical experiments. Moreover, a dynamical interpretation of the
renormalization of the dispersion relation is provided via a self-consistency,
mean-field argument. It turns out that this renormalization arises mainly from
the trivial resonant wave interactions, i.e., interactions with no momentum
exchange. Furthermore, using a multiple time-scale, statistical averaging
method, we show that the interactions of near-resonant waves give rise to the
broadening of the resonance peaks in the frequency spectrum of renormalized
modes. The theoretical prediction for the resonance width for the thermalized
$\beta$-FPU chain is found to be in very good agreement with its numerically
measured value.",0703051v1
2005-03-15,Resonance production in heavy ion collisions,"Recent results of resonance production from RHIC at $\sqrt{s_{\rm NN}} = $
200 GeV and SPS at $\sqrt{s_{\rm NN}} = $ 17 GeV are presented and discussed in
terms of the evolution and freeze-out conditions of a hot and dense fireball
medium. Yields and spectra are compared with thermal model predictions at
chemical freeze-out. Deviations in the low transverse momentum region of the
resonance spectrum of the hadronic decay channel, suggest a strongly
interaction hadronic phase between chemical and kinetic freeze-out. Microscopic
models including resonance rescattering and regeneration are able to describe
the trend of the data. The magnitude of the regeneration cross sections for
different inverse decay channels are discussed. Model calculations which
include elastic hadronic interactions between chemical freeze-out and thermal
freeze-out based on the K(892)/K and $\Lambda$(1520)/$\Lambda$ ratios suggest a
time between two freeze-outs surfaces of $\Delta \tau>$ 4 fm/c. The difference
in momentum distributions and yields for the $\phi$(1020) resonance
reconstructed from the leptonic and hadronic decay channels at SPS energy are
discussed taking into account the impact of a hadronic phase and possible
medium modifications.",0503011v2
2007-02-09,Study of the 12C+12C fusion reactions near the Gamow energy,"The fusion reactions 12C(12C,a)20Ne and 12C(12C,p)23Na have been studied from
E = 2.10 to 4.75 MeV by gamma-ray spectroscopy using a C target with ultra-low
hydrogen contamination. The deduced astrophysical S(E)* factor exhibits new
resonances at E <= 3.0 MeV, in particular a strong resonance at E = 2.14 MeV,
which lies at the high-energy tail of the Gamow peak. The resonance increases
the present non-resonant reaction rate of the alpha channel by a factor of 5
near T = 8x10^8 K. Due to the resonance structure, extrapolation to the Gamow
energy E_G = 1.5 MeV is quite uncertain. An experimental approach based on an
underground accelerator placed in a salt mine in combination with a high
efficiency detection setup could provide data over the full E_G energy range.",0702023v1
1995-06-30,The eta Photoproduction of Nucleons and The structure of the Resonance S11(1535) in The Quark Model,"In this paper, we present our study on the $\eta$ photoproduction based on
the chiral quark model. We find that quark model provides a very good
description of the $\eta$ production with much less parameters, and the
threshold region is not a reliable source to determine the $\eta NN$ coupling
constant due to its strong dependence on the properties of the resonance
$S_{11}(1535)$. We suggest that the systematic data in $E_{lab}=1.2 \sim 1.4$
GeV region may help us to determine the $\eta NN$ coupling constant more
precisely.
  The structure of the resonance $S_{11}(1535)$ is discussed, we find that the
recent data from Mainz group bring the helicity amplitude much closer to the
quark model prediction. However, more studies need to be done to understand the
large $\eta N$ branching ratio of the resonance $S_{11}(1535)$. Our results
show that the quark model is a very good approach to study the underlying
structure of baryon resonances from the meson photoproduction data.",9506033v1
1996-06-19,The Multichannel Quark Model,"We discuss the non-relativistic multichannel quark model and describe the
techniques developed to solve the resulting equations. We then investigate some
simple solutions to demonstrate how the model unifies meson-meson scattering
with meson spectroscopy, thereby greatly extending the domain of applicability
of the naive quark model. In the limits of narrow resonance widths and no quark
exchange, it reproduces the standard quark model spectroscopy and Breit-Wigner
phase description. Outside those limits s-channel resonance masses are lowered
by their two-meson couplings, the line-shapes of wide resonances are
significantly altered, and the equivalent Breit-Wigner masses and widths show
an energy dependence. Because meson-meson interactions are due to coherent
s-channel resonance production and t-channel quark exchange (though other
interactions can readily be added), the multichannel equations model
experimental resonance production and decay in a way that the usual eigenvalue
equations cannot.",9606037v1
1996-09-03,The Spectral Line Shape of Exotic Nuclei,"The quadrupole strength function of $^{28}O$ is calculated making use of the
SIII interaction, within the framework of continuum-RPA and taking into account
collisions among the nucleons (doorway coupling). The centroid of the giant
resonance is predicted at $\approx 14$ MeV, that is much below the energy
expected for both isoscalar and isovector quadrupole resonances in nuclei along
the stability valley. About half of this width arises from the coupling of the
resonance to the continuum and about half is due to doorway coupling. This
result is similar to that obtained in the study of giant resonances in light,
$\beta$-stable nuclei, and shows the lack of basis for the expectation,
entertained until now in the literature, that continuum decay was the main
damping mechanism of giant resonances in halo nuclei.",9609010v1
1997-02-12,Treatment of baryonic resonances in the RQMD approach including scalar-vector mean fields,"In the relativistic Quantum Molecular Dynamics (RQMD) approach baryons are
described within the framework of covariant hamilton constraint dynamics. The
inclusion of a relativistic mean field results in a quasiparticle picture for
the baryons. This requires to distinguish between canonical and kinetic
variables of the particles. As resonances we include the $\Delta$(1232) and the
$N^*$(1440) resonance. The resonance masses are distributed according
Breit-Wigner functions. However, the scalar self energy leads to a shift in the
masses and introduces an additional medium dependence. Consequences of this
description on resonance and pion dynamics are discussed.",9702028v1
1997-08-05,On the extraction of electromagnetic properties of the Delta(1232) excitation from pion photoproduction,"Several methods for the treatment of pion photoproduction in the region of
the Delta(1232) resonance are discussed, in particular the effective Lagrangian
approach and the speed plot analysis are compared to a dynamical treatment. As
a main topic, we discuss the extraction of the genuine resonance parts of the
magnetic dipole and electric quadrupole multipoles of the electromagnetic
excitation of the resonance. To this end, we try to relate the various values
for the ratio R_{EM} of the E2 to M1 multipole excitation strengths for the
Delta(1232) resonance as extracted by the different methods to corresponding
ratios of a dynamical model. Moreover, it is confirmed that all methods for
extracting resonance properties suffer from an unitary ambiguity which is due
to some phenomenological contributions entering the models.",9708005v1
1999-01-22,Nucleon Resonances in Kaon Photoproduction,"Nucleon resonances are investigated through the electromagnetic production of
K-mesons. We study the kaon photoproduction process at tree-level and compare
to a recently developed unitary K-matrix approach. Employing hadronic form
factors along with the proper gauge prescription yields suppression of the Born
terms and leads a resonance dominated process for both K-Lambda and K-Sigma
photoproduction. Using new SAPHIR data we find the K+-Lambda photoproduction to
be dominated by the S11(1650) at threshold, with additional contributions from
the P11(1710) and P13(1720) states. The K-Sigma channel couples to a cluster of
Delta resonances around W = 1900 MeV. We briefly discuss some tantalizing
evidence for a missing D13 resonance around 1900 MeV with a strong branching
ratio into KLambda channel.",9901066v1
1999-02-24,Nucleon Resonance Effects in $pp\to ppπ^0$ near Threshold,"The role of the low lying nucleon resonances beyond the $\Delta(1232)$ in the
reaction $pp\to pp\pi^0$ near threshold is shown to be numerically significant
by a calculation, which takes into account the pion re-scattering contribution
described by chiral perturbation theory and the short-range mechanisms that are
implied by the nucleon-nucleon interaction model. The intermediate N(1440)
(P$_{11}$) resonance is excited by the short-range exchange mechanisms, while
the N(1535) ($S_{11}$) and N(1520) ($D_{13}$) resonances are excited by $\eta$
and $\rho$ meson exchange, respectively. The $P_{11}$ increases the calculated
cross section, whereas the $S_{11}$ and $D_{13}$ resonances decrease it. The
calculation takes full account of the initial and final state interactions.",9902066v2
1999-02-25,Radiative production of the Lambda(1405) resonance in K collisions on protons and nuclei,"We have carried a theoretical study of the K^- p\to M B \gamma reaction with
M B = K^-p, \bar{K}^0 n, \pi^- \Sigma^+, \pi^+ \Sigma^-, \pi^0 \Sigma^0, \pi^0
\Lambda, for K^- lab. momenta between 200 and 500 MeV/c, using a chiral unitary
approach for the strong K^-p interaction with its coupled channels. The
\Lambda(1405) resonance, which is generated dynamically in this approach, shows
up clearly in the d\sigma/dM_I spectrum, providing new tests for chiral
symmetry and the unitary approach, as well as information regarding the nature
of the resonance. The photon detection alone, summing all channels, is shown to
reproduce quite accurately the strength and shape of the \Lambda(1405)
resonance. Analogous reactions in nuclei can provide much information on the
properties of this resonance in a nuclear medium.",9902071v1
1999-06-08,Resonances and Off-Shell Characteristics of Effective Interactions,"The importance of including experimental resonances in constructing effective
inter-cluster interactions has been investigated. For this, we first address
the question of how to obtain the analytical properties of the Jost function in
regions of physical interest on the complex k-plane when the potential is given
in a tabular form. We then employ the Marchenko inverse scattering method to
construct, numerically, phase equivalent local potentials supporting the same
bound state(s) but having different resonance spectra which affect the
off-shell characteristics of the corresponding scattering amplitudes. This
implies that the inclusion of the experimental resonances in constructing a
potential would change its shape, strength, and range which in turn would
modify the bound and scattering wave functions in the interior region. This is
expected to have important consequences in calculations of transition
amplitudes in nuclear reaction theories, which strongly depend on the behaviour
of the wave functions at short distances. The influence of Supersymmetric
Transformations on the position and movement of resonances has also been
investigated.",9906020v1
1999-09-22,"Nucleonic resonance excitations and ""missing resonances"" in the $ω$ meson photoproduction","In this work, an improved quark model approach to the $\omega$ meson
photoproduction with an effective Lagrangian is reported. The {\it t}-channel
{\it natural} parity exchange is consistently taken into account through the
Pomeron exchange, while the {\it unnatural} parity exchange is described by the
$\pi^0$ exchange. It shows that with very limited number of parameters, all the
available experimental data in the low energy regime can be consistently
accounted for in this framework. Effects from the intermediate nucleonic
resonances are investigated in several polarization observables. The
sensitivities of these observables to the resonance effects are probably the
best way for identifying those so-called ""missing resonances"" in the baryon
spectrum.",9909060v1
2000-06-25,Nucleon resonances in omega photoproduction,"The role of the nucleon resonances ($N^*$) in $\omega$ photoproduction is
investigated by using the resonance parameters predicted by Capstick and
Roberts [Phys. Rev. D {\bf 46}, 2864 (1992); {\bf 49}, 4570 (1994)]. In
contrast with the previous investigations based on the ${SU}(6) \times {O}(3)$
limit of the constituent quark model, the employed $N^* \to \gamma N$ and $N^*
\to \omega N$ amplitudes include the configuration mixing effects due to the
residual quark-quark interactions. The contributions from the nucleon
resonances are found to be significant relative to the non-resonant amplitudes
in changing the differential cross sections at large scattering angles and
various spin observables. In particular, we suggest that a crucial test of our
predictions can be made by measuring the parity asymmetry and beam-target
double asymmetry at forward scattering angles.",0006057v3
2000-09-08,Coulomb Excitation of Double Giant Dipole Resonances,"We implement the Brink-Axel hypothesis for the excitation of the double giant
dipole resonance (DGDR): The background states which couple to the one-phonon
giant dipole resonance are themselves capable of dipole absorption. These
states (and the ones which couple to the two-phonon resonance) are described in
terms of the Gaussian Orthogonal Ensemble of random matrices. We use
second-order time-dependent perturbation theory and calculate analytically the
ensemble-averaged cross section for excitation of the DGDR. Numerical
calculations illuminate the mechanism and the dependence of the cross section
on the various parameters of the theory, and are specifically performed for the
reaction $^{208}$Pb + $^{208}$Pb at a projectile energy of 640 MeV/nucleon. We
show that the contribution of the background states to the excitation of the
DGDR is significant. We find that the width of the DGDR, the energy-integrated
cross section and the ratio of this quantity over the energy-integrated cross
section for the single giant dipole resonance, all agree with experiment within
experimental errors. We compare our approach with that of Carlson {\it et al.}
who have used a similar physical picture.",0009025v1
2001-04-13,Higher and missing resonances in omega photoproduction,"We study the role of the nucleon resonances ($N^*$) in $\omega$
photoproduction by using the quark model resonance parameters predicted by
Capstick and Roberts. The employed $\gamma N \to N^*$ and $N^* \to \omega N$
amplitudes include the configuration mixing effects due to the residual
quark-quark interactions. The contributions from the nucleon resonances are
found to be important in the differential cross sections at large scattering
angles and various spin observables. In particular, the parity asymmetry and
beam-target double asymmetry at forward scattering angles are suggested for a
crucial test of our predictions. The dominant contributions are found to be
from $N\frac32^+ (1910)$, a missing resonance, and $N\frac32^- (1960)$ which is
identified as the $D_{13}(2080)$ of the Particle Data Group.",0104046v2
2001-06-04,An isobar model for eta photo- and electroproduction on the nucleon,"An isobar model containing Born terms, vector meson exchange and nucleon
resonances is used to analyze recent eta photoproduction data for cross section
and beam asymmetry, as well as JLab electroproduction data. Good overall
description is achieved up to Q^2 = 4.0 (GeV/c)^2. Besides the dominant
S11(1535) resonance, we show that the second S11 resonance, S11(1650), is also
necessary to be included in order to extract S11(1535) resonance parameters
properly. In addition, the beam asymmetry data allow us to extract very small
(<0.1%) N* --> eta N decay branching ratios of D13(1520) and F15(1680)
resonances because of the overwhelming s-wave dominance. The model is
implemented as a part of the MAID program.",0106006v1
2001-06-28,The relativistic spectroscopy of rotating bodies,"Mutual dependencies of mass and orbital moment increase for rotating bodies
of various configurations (a string with uniform mass distribution, a string
with squared mass distribution or a sphere with uniform mass distribution,
double system of point masses) are considered in quasiclassical approximation.
Results are used for analysis of meson, baryon resonances of rotating nature,
and also for dipion and dinucleon resonances. For oneparticle resonances a
string configuration with squared mass distribution is has been chosen. Radius
values and their possible changes with spin increase are obtained. At this, in
particular, for proton and $\delta$-isobar, which are the founders of rotating
bands, values 0.45 and 0.63 are defined, respectively. Dipion and dinucleon
resonances are pre-sented as two rotating point bodies at distances of some
fermy. Each of reso-nances is located in four rotary bands. Possible reasons of
formation of some rotary bands for these resonances are discussed.",0106068v1
2001-10-12,An isobar model for eta photo- and electroproduction on the nucleon,"Eta photo- and electroproduction on the nucleon is studied using an isobar
model. The model contains Born terms, and contributions from vector meson
exchanges and nucleon resonances. Our results are compared with recent eta
photoproduction data for differential and total cross sections, beam asymmetry,
and target asymmetry, as well as electroproduction data. Besides the dominant
S11(1535) resonance, we show that the second S11 resonance, S11(1650), is also
necessary to be included in order to extract S11(1535) resonance parameters
properly. In addition, the beam asymmetry data allow us to extract very small
(<0.1%) N* --> eta N decay branching ratios of the D13(1520) and F15(1680)
resonances because of the overwhelming s-wave dominance. This model (ETA-MAID)
is implemented as a part of the MAID program.",0110034v1
2002-02-22,Sigma photoproduction in the resonance region,"A study of p(gamma,K)Sigma processes in an isobar model at tree level is
reported. By comparing model calculations to the published SAPHIR data, we
explore the possible role of different isospin I=1/2 (N*) and I=3/2 (Delta*)
resonances in the reaction dynamics. In our analysis, the inclusion of the
``missing'' D_{13}(1895) resonance does only slightly improve the global
description of the Sigma photoproduction data. More convincing signals for the
presence of such a ``missing'' resonance emerged in the analysis of the isospin
related p(gamma,K+)Lambda reaction. Various implementations of the nonresonant
part of the Sigma photoproduction amplitude are presented. The sensitivity of
the computed observables and extracted resonance parameters to the
uncertainties inherent to the treatment of the nonresonant (background)
diagrams are discussed.",0202074v2
2002-04-19,In-medium Effects in the Eta-Photoproduction through the $S_{11}$ Resonance with the Relativistic Approach,"In-medium effects in photon excitation of the S$_{11}$ resonance from nucleon
and its decay to $\eta$-meson using the RMF approach is studied. We examine the
in-medium effects by varing the Dirac fields of the nucleon and the S$_{11}$
resonance separately. We obtained a conclusion that the Dirac fields of the
nucleon, which reduces the nucleon effective mass, enlarge the width of
S$_{11}$ resonance, and small Dirac-fields of the resonance shifts the peak
position, and these combined effects can explain the in-medium properties
observed in the experimental data for $^{12}$C($\gamma$,$\eta$) reaction.",0204051v2
2002-09-05,Chiral unitary approach to hadron spectroscopy,"The s-wave meson-baryon interaction in the $S = -1$, $S= 0$ and $S= -2$
sectors is studied by means of coupled channels, using the lowest-order chiral
Lagrangian and the N/D method or equivalently the Bethe-Salpeter equation to
implement unitarity.
  This chiral approach leads to the dynamical generation of the $\Lambda
(1405)$, $\Lambda(1670)$ and $\Sigma(1620)$ states for $S = -1$, the
$N^*(1535)$ for $S= 0$ and the $\Xi(1620)$ for $S= -2$. We look for poles in
the complex plane and extract the couplings of the resonances to the different
final states. This allows identifying the $\Lambda (1405)$ and the
$\Lambda(1670)$ resonances with $\bar{K}N$ and $K\Xi$ quasibound states,
respectively. Our results are found to be incompatible with the measured
properties of the $\Xi(1690)$ resonance, thus ruling this state out as the
remaining member of this octet of dynamically generated resonances. We
therefore assign $1/2^-$ for the spin and parity of the $\Xi(1620)$ resonance
as the $S=-2$ member of the lowest-lying $1/2^-$ octet.",0209018v1
2003-02-22,Euclidean resonance and a new type of nuclear reactions,"The extremely small probability of quantum tunneling through an almost
classical potential barrier may become not small under the action of the
specially adapted nonstationary field. The tunneling rate has a sharp peak as a
function of the particle energy when it is close to the certain resonant value
defined by the nonstationary field (Euclidean resonance). Alpha decay of nuclei
has a small probability since the alpha particle should tunnel through a very
nontransparent Coulomb barrier. The incident proton, due to the Coulomb
interaction with the tunneling alpha particle, plays the role of a
nonstationary field which may result in Euclidean resonance in tunneling of the
alpha particle. At the resonant proton energy, which is of the order of 0.2
Mev, the alpha particle escapes the nucleus and goes to infinity with no
influence of the nuclear Coulomb barrier. The process is inelastic since the
alpha particle releases energy and the proton gains it. This stimulation of
alpha decay by a proton constitutes a new type of nuclear reactions.",0302066v1
2003-05-13,Structure of positive energy states in a deformed mean-field potential,"We investigate the properties of single-particle resonances in a
non-spherical potential by solving the coupled-channels equations for the
radial wave functions. We first generalize the box discretization method for
positive energy states to a deformed system. As in the spherical case, we find
that the discretized energy is stabilized against the box size when a resonance
condition is met. Using the wave functions thus obtained, we then discuss the
energy and the radial dependences of scattering wave functions in the vicinity
of an isolated resonance. In the eigenchannel basis, where the $S$-matrix is
diagonal, we propose a generalized expression for the factorization formula for
the multi-channel wave function. We find that the factorized wave function
agrees well with the exact solution inside the centrifugal barrier when the
energy distance from the resonance is less than the resonance width.",0305034v2
2003-05-30,Quark mass dependence of s-wave baryon resonances,"We study the quark mass dependence of $J^P = \frac12^-$ s-wave baryon
resonances. Parameter free results are obtained in terms of the leading order
chiral Lagrangian. In the 'heavy' SU(3) limit with $m_\pi =m_K \simeq $ 500 MeV
the resonances turn into bound states forming two octets plus a singlet
representations of the SU(3) group. A contrasted result is obtained in the
'light' SU(3) limit with $m_\pi =m_K \simeq $ 140 MeV for which no resonances
exist. Using physical quark masses our analysis suggests to assign to the
$S=-2$ resonances $\Xi(1690)$ and $\Xi(1620)$ the quantum numbers $J^P=1/2^-$.",0305100v3
2003-06-11,Pairing correlations and resonant states in the relativistic mean field theory,"We present a simple scheme for taking into account the resonant continuum
coupling in the Relativistic Mean Field- BCS (RMF-BCS) calculations. In this
scheme, applied before in non-relativistic calculations, the effect of the
resonant continuum on pairing correlations is introduced through the scattering
wave functions located in the region of the resonant states. These states are
found by solving the relativistic mean field equations with scattering-type
boundary conditions for continuum spectrum. The calculations are done for the
neutron-rich Zr isotopes. It is shown that the sudden increase of the neutron
radii close to the neutron drip line, the so-called giant halo, is determined
by a few resonant states close to the continuum threshold.",0306035v1
2003-06-23,"Self consistent and covariant propagation of pions, nucleon and isobar resonances in cold nuclear matter","We evaluate the in-medium spectral functions for pions, nucleon and isobar
resonances in a self consistent and covariant manner. The calculations are
based on a recently developed formulation which leads to predictions in terms
of the pion-nucleon scattering phase shifts and a set of Migdal parameters
describing important short range correlation effects. We do not observe
significant softening of pion modes if we insist on reasonable isobar resonance
properties but predict a considerable broadening of the N(1440) and N(1520)
resonances in nuclear matter. Contrasted results are obtained for the s-wave
N(1535) and N(1650) resonances which are affected by a nuclear environment very
little. The properties of slowly moving isobar's in nuclear matter are found to
depend very sensitively on a soft form factor in the piNN vertex, which is not
controlled by the piN scattering data.",0306063v2
2003-07-09,On meson resonances and chiral symmetry,"We study meson resonances with quantum numbers J^P=1^+ in terms of the chiral
SU(3) Lagrangian. At leading order a parameter-free prediction is obtained for
the scattering of Goldstone bosons off vector mesons with J^P=1^- once we
insist on approximate crossing symmetry of the unitarized scattering amplitude.
A resonance spectrum arises that is remarkably close to the empirical pattern.
In particular, we find that the strangeness-zero resonances h_1(1380), f_(1285)
and b_1(1235) are formed due to strong K \bar K_\mu and \bar K K_\mu channels.
This leads to large coupling constants of those resonances to the latter
states.",0307039v3
2003-08-23,Model Dependence of the Properties of S11 Baryon Resonances,"The properties of baryon resonances are extracted from a complicated process
of fitting sophisticated, empirical models to data. The reliability of this
process comes from the quality of data and the robustness of the models
employed. With the large of amount of data coming from recent experiments, this
is an excellent time for a study of the model dependence of this extraction
process. A test case is chosen where many theoretical details of the model are
required, the S11 partial wave. The properties of the two lowest N* resonances
in this partial wave are determined using various models of the resonant and
non-resonant amplitudes.",0308066v2
2003-08-28,Structure of the Isovector Dipole Resonance in Neutron-Rich $^{60}Ca$ Nucleus and Direct Decay from Pygmy Resonance,"The structure of the isovector dipole resonance in neutron-rich calcium
isotope, $^{60}Ca$, has been investigated by implementing a careful treatment
of the differences of neutron and proton radii in the continuum random phase
approximation ($RPA$). The calculations have taken into account the current
estimates of the neutron skin. The estimates of the escape widths for direct
neutron decay from the pygmy dipole resonance ($PDR$) were shown rather wide,
implicating a strong coupling to the continuum. The width of the giant dipole
resonance ($GDR$) was evaluated, bringing on a detailed discussion about its
microscopic structure.",0308081v2
2003-12-24,Non-extensive resonant reaction rates in astrophysical plasmas,"We study two different physical scenarios of thermonuclear reactions in
stellar plasmas proceeding through a narrow resonance at low energy or through
the low energy wing of a wide resonance at high energy. Correspondingly, we
derive two approximate analytical formulae in order to calculate thermonuclear
resonant reaction rates inside very coupled and non ideal astrophysical plasmas
in which non-extensive effects are likely to arise. Our results are presented
as simple first order corrective factors that generalize the well known
classical rates obtained in the framework of Maxwell-Boltzmann statistical
mechanics. As a possible application of our results, we calculate the
dependence of the total corrective factor with respect to the energy at which
the resonance is located, in an extremely dense and non ideal carbon plasma.",0312105v1
2004-01-16,Quark-mass dependence of baryon resonances,"We study the quark-mass dependence of J^P = \frac12^- s-wave and J^P =
\frac32^- d-wave baryon resonances. Parameter-free results are obtained in
terms of the leading order chiral Lagrangian. In the 'heavy' SU(3) limit with
m_\pi =m_K \simeq 500 MeV the s-wave resonances turn into bound states forming
two octets plus a singlet representations of the SU(3) group. Similarly the
d-wave resonances turn into bound states forming an octet and a decuplet in
this limit. A contrasted result is obtained in the 'light' SU(3) limit with
m_\pi =m_K \simeq 140 MeV for which no resonances exist.",0401035v1
2004-02-04,Effect of resonance decays on hadron elliptic flows,"The influence of resonance decays on the elliptic flows of stable hadrons is
studied in the quark coalescence model. Although difference between the
elliptic flow of pions from resonance decays, except the rho meson, and that of
directly produced pions is appreciable, those for other stable hadrons are
small. Since there are more pions from the decays of rho mesons than from other
resonances, including resonance decays can only account partially the deviation
of final pion elliptic flow from the observed scaling of hadron elliptic flows,
i.e., the hadron elliptic flow per quark is the same at same transverse
momentum per quark. The remaining deviation can be explained by including the
effect due to the quark momentum distribution inside hadrons.",0402020v2
2005-01-11,"Baryonic Resonances from Baryon Decuplet-Meson Octet Interactions and the Exotic Resonance S=1, I=1, J^P=3/2-","Using the lowest order chiral Lagrangian we study s-wave interactions of the
baryon decuplet with the octet of pseudoscalar mesons. We find two bound states
in the flavour SU(3) limit corresponding to the octet and decuplet
representations. These are found to split into eight different trajectories in
the complex plane when the SU(3) symmetry is broken gradually. Finally, we are
able to provide a reasonable description for a good number of 4-star 3/2-
resonances listed by the Particle Data Group. In particular, the Xi(1820), the
Lambda(1520) and the Sigma(1670) states are well reproduced. We predict a few
other resonances and also evaluate the couplings of the observed resonances to
the various channels from the residues at the poles of the scattering matrix
from where partial decay widths into different channels can be evaluated.",0501027v1
2005-02-18,Sum Rule Approach to the Isoscalar Giant Monopole Resonance in Drip Line Nuclei,"Using the density-dependent Hartree-Fock approximation and Skyrme forces
together with the scaling method and constrained Hartree-Fock calculations, we
obtain the average energies of the isoscalar giant monopole resonance. The
calculations are done along several isotopic chains from the proton to the
neutron drip lines. It is found that while approaching the neutron drip line,
the scaled and the constrained energies decrease and the resonance width
increases. Similar but smaller effects arise near the proton drip line,
although only for the lighter isotopic chains. A qualitatively good agreement
is found between our sum rule description and the presently existing random
phase approximation results. The ability of the semiclassical approximations of
the Thomas-Fermi type, which properly describe the average energy of the
isoscalar giant monopole resonance for stable nuclei, to predict average
properties for nuclei near the drip lines is also analyzed. We show that when
hbar corrections are included, the semiclassical estimates reproduce, on
average, the quantal excitation energies of the giant monopole resonance for
nuclei with extreme isospin values.",0502055v2
2005-11-23,Dynamical generation of $J^P=3/2-$ resonances and the $Λ(1520)$ resonance,"The lowest order chiral Lagrangian is used to study s-wave interactions of
the baryon decuplet with the octet of pseudoscalar mesons. The coupled channel
Bethe Salpeter equation is used to obtain dynamically generated
$\tfrac{3}{2}^-$ resonances in the partial wave amplitudes which provide a
reasonable description to a number of 3 and 4-star resonances like
$\Delta(1700)$, $\Lambda(1520)$, $\Sigma(1670)$, $\Sigma(1940)$, $\Xi(1820)$,
$\Omega(2250)$ etc. The phenomenological introduction of d-wave channels in the
coupled channel scheme along with the existing s-wave channels is shown to
provide a much improved description of the $\Lambda(1520)$ resonance. The
prediction of the absolute strength of the cross section in the reactions
$K^-p\to\Lambda\pi^0\pi^0$ and $K^-p\to\Lambda\pi^+\pi^-$ provided by this
scheme shows a good agreement with existing data.",0511062v1
2007-02-09,Photoproduction of eta-mesons on the deuteron above S11(1535) in the presence of a narrow P11(1670) resonance,"Incoherent photoproduction of eta-mesons on the deuteron is considered. The
main attention is paid to the region above the S11(1535) resonance where rather
narrow resonance like structure in the total cross section extracted for gamma
n -> eta n has been reported. The corresponding experimental results are
analyzed from the phenomenological standpoint within the model containing a
baryon P11 with the mass about 1670 MeV and a width less than 30 MeV. This
resonance was suggested in some recent works as a nonstrange member of the
pentaquark antidecuplet with J^P=1/2^+. The calculation is also performed for
the polarized and nonpolarized angular distributions of $\eta$ mesons. In
addition, we present our predictions for the cross sections of the neutral
kaons and double pion photoproduction, where the same narrow P11(1670)
resonance is assumed to contribute through the decay into K^0 Lambda and pi
Delta configuration.",0702034v2
1997-03-07,Resonance structure in the Li^- photodetachment cross section,"We report on the first observation of resonance structure in the total cross
section for the photodetachment of Li^-. The structure arises from the
autodetaching decay of doubly excited ^1P states of Li^- that are bound with
respect to the 3p state of the Li atom. Calculations have been performed for
both Li^- and H^- to assist in the identification of these resonances. The
lowest lying resonance is a symmetrically excited intrashell resonance. Higher
lying asymmetrically excited intershell states are observed which converge on
the Li(3p) limit.",9703015v1
1998-10-01,Resonance broadening theory of Farley-Buneman turbulence in the auroral E-region,"The conventional theory of resonance broadening for a two-species plasma in a
magnetic field is revised, and applied to an ionospheric turbulence case. The
assumptions made in the conventional theory of resonance broadening have, in
the past, led to replacing the frequency $\omega$ by
$\omega+ik_{\perp}^{2}D^{*}$ in the resonant part of the linear dielectric
function to obtain the nonlinear dielectric function. Where $D^{*}$ is an
anomalous diffusion coefficient due solely to wave scattering of the particle
orbits. We show that in general these assumptions are not valid, and
consequently the straightforward substitution of frequencies is not legitimate.
We remedy these problems and derive expressions for the time-dependent
components of the diffusion tensor. The improved resonance broadening theory is
developed in the context of an ionospheric problem, namely that of the
Farley-Buneman turbulence in the auroral E-region. A kinetic description of the
electrons is used. A general expression for the nonlinear dielectric function
is derived in the special case where no parallel electric field is present, and
the differences with the conventional dispersion relation are discussed.",9810061v1
2003-09-05,Opto-mechanical probes of resonances in amplifying microresonators,"We investigate whether the force and torque exerted by light pressure on an
irregularly shaped dielectric resonator allow to detect resonant frequencies,
delivering information complemental to the scattering cross section by
mechanical means. The peak-to-valley ratio in the torque signal can be many
times larger than in the scattering cross section, and, furthermore, depends on
the structure of the resonance wave pattern. The far-field emission pattern of
the associated quasi-bound states can be tested by the angular dependence of
the mechanical probes at finite amplification rate. We relate the force and
torque to the scattering matrix and present numerical results for an annularly
shaped dielectric resonator.",0309035v2
2003-10-02,Double-resonant extremely asymmetrical scattering of electromagnetic waves in periodic arrays separated by a gap,"Two strong simultaneous resonances of scattering--double-resonant extremely
asymmetrical scattering (DEAS)--are predicted in two parallel, oblique,
periodic Bragg arrays separated by a gap, when the scattered wave propagates
parallel to the arrays. One of these resonances is with respect to frequency
(which is common to all types of Bragg scattering), and another is with respect
to phase variation between the arrays. The diffractional divergence of the
scattered wave is shown to be the main physical reason for DEAS in the
considered structure. Although the arrays are separated, they are shown to
interact by means of the diffractional divergence of the scattered wave across
the gap from one array into the other. It is also shown that increasing
separation between the two arrays results in a broader and weaker resonance
with respect to phase shift. The analysis is based on a recently developed new
approach allowing for the diffractional divergence of the scattered wave inside
and outside the arrays. Physical interpretations of the predicted features of
DEAS in separated arrays are also presented. Applicability conditions for the
developed theory are derived.",0310011v1
2003-11-18,Near-field enhancement and imaging in double planar polariton-resonant structures,"It is shown that a system of two coupled planar material sheets possessing
surface mode (polariton) resonances can be used for the purpose of evanescent
field restoration and, thus, for the sub-wavelength near-field imaging. The
sheets are placed in free space so that they are parallel and separated by a
certain distance. Due to interaction of the resonating surface modes
(polaritons) of the sheets an exponential growth in the amplitude of an
evanescent plane wave coming through the system can be achieved. This effect
was predicted earlier for backward-wave (double-negative or Veselago) slab
lenses. The alternative system considered here is proved to be realizable at
microwaves by grids or arrays of resonant particles. The necessary
electromagnetic properties of the resonating grids and the particles are
investigated and established. Theoretical results are supported by microwave
experiments that demonstrate amplification of evanescent modes.",0311089v1
2004-02-29,Interferometric differentiation between resonant Coherent Anti-Stokes Raman Scattering and nonresonant four-wave-mixing processes,"A major impediment of using Coherent Anti-Stokes Raman Scattering to identify
biological molecules is that the illumination levels required to produce a
measurable signal often also produce significant nonresonant background from
the medium, especially from water, that is not specific to the resonance being
investigated. We present a method of using nonlinear interferometry to measure
the temporal shape of the anti-Stokes signal to differentiate which components
are resonant and nonresonant. This method is easily adaptable to most existing
pulsed CARS illumination methods and should allow for distinguishing resonant
CARS when using higher energy pulses. By examining the differences between
signals produced by acetone and water, we show that the resonant and
nonresonant signals can be clearly differentiated.",0403007v1
2004-09-29,Accumulation of three-body resonances above two-body thresholds,"We calculate resonances in three-body systems with attractive Coulomb
potentials by solving the homogeneous Faddeev-Merkuriev integral equations for
complex energies. The equations are solved by using the Coulomb-Sturmian
separable expansion approach. This approach provides an exact treatment of the
threshold behavior of the three-body Coulombic systems. We considered the
negative positronium ion and, besides locating all the previously know $S$-wave
resonances, we found a whole bunch of new resonances accumulated just slightly
above the two-body thresholds. The way they accumulate indicates that probably
there are infinitely many resonances just above the two-body thresholds, and
this might be a general property of three-body systems with attractive Coulomb
potentials.",0409149v1
2004-11-08,Spectral Properties and Lifetimes of Neutral Spin-1/2-Fermions in a Magnetic Guide,"We investigate the resonant motion of neutral spin-1/2-fermions in a magnetic
guide. A wealth of unitary and anti-unitary symmetries is revealed in
particular giving rise to a two-fold degeneracy of the energy levels. To
compute the energies and decay widths of a large number of resonances the
complex scaling method is employed. We discuss the dependence of the lifetimes
on the angular momentum of the resonance states. In this context the existence
of so-called quasi-bound states is shown. In order to approximately calculate
the resonance energies of such states a radial Schr\""odinger equation is
derived which improves the well-known adiabatic approximation. The effects of
an additionally applied homogeneous Ioffe field on the resonance energies and
decay widths are also considered. The results are applied to the case of the
$^6\text{Li}$ atom in the $F=1/2$ hyperfine ground state.",0411079v1
2004-11-19,Particle acceleration through the resonance of high magnetic field and high frequency electromagnetic wave,"We propose a new particle acceleration mechanism. Electron can be accelerated
to relativistic energy within a few electromagnetic wave cycles through the
mechanism which is named electromagnetic and magnetic field resonance
acceleration (EMRA). We find that the electron acceleration depends not only on
the electromagnetic wave intensity, but also on the ratio between electron
Larmor frequency and electromagnetic wave frequency. As the ratio approaches to
unity, a clear resonance peak is observed, corresponding to the EMRA. Near the
resonance regime, the strong magnetic fields still affect the electron
acceleration dramatically. We derive an approximate analytical solution of the
relativistic electron energy in adiabatic limit, which provides a full
understanding of this phenomenon. In typical parameters of pulsar
magnetospheres, the mechanism allows particles to increase their energies
through the resonance of high magnetic field and high frequency electromagnetic
wave in each electromagnetic wave period. The energy spectra of the accelerated
particles exhibit the synchrotron radiation behavior. These can help to
understand the remaining emission of high energy electron from radio pulsar
within supernova remnant. The other potential application of our theory in fast
ignition scheme of inertial confinement fusion is also discussed.",0411183v1
2005-05-20,The role of quasi-momentum in the resonant dynamics of the atom-optics kicked rotor,"We examine the effect of the initial atomic momentum distribution on the
dynamics of the atom-optical realisation of the quantum kicked rotor. The atoms
are kicked by a pulsed optical lattice, the periodicity of which implies that
quasi-momentum is conserved in the transport problem. We study and compare
experimentally and theoretically two resonant limits of the kicked rotor: in
the vicinity of the quantum resonances and in the semiclassical limit of
vanishing kicking period. It is found that for the same experimental
distribution of quasi-momenta, significant deviations from the kicked rotor
model are induced close to quantum resonance, while close to the classical
resonance (i.e. for small kicking period) the effect of the quasi-momentum
vanishes.",0505143v2
2006-01-09,Resonant coupling between localized plasmons and anisotropic molecular coatings in ellipsoidal metal nanoparticles,"We present an analytic theory for the optical properties of ellipsoidal
plasmonic particles covered by anisotropic molecular layers. The theory is
applied to the case of a prolate spheroid covered by chromophores oriented
parallel and perpendicular to the metal surface. For the case that the
molecular layer resonance frequency is close to being degenerate with one of
the particle plasmon resonances strong hybridization between the two resonances
occur. Approximate analytic expressions for the hybridized resonance
frequencies, their extinction cross section peak heights and widths are
derived. The strength of the molecular - plasmon interaction is found to be
strongly dependent on molecular orientation and suggest that this sensitivity
could be the basis for novel nanoparticle based bio/chemo-sensing applications.",0601042v1
2006-01-25,A Tabulation and Critical Analysis of the Wavelength-Dependent Dielectric Image Coefficient for the Interaction Exerted by a Surface onto a Neighbouring Excited Atom,"The near-field interaction of an atom with a dielectric surface is inversely
proportional to the cube to the distance to the surface, and its coupling
strength depends on a dielectric image coefficient. This coefficient, simply
given in a pure electrostatic approach by (eps-1) / (eps+1) with eps the
permittivity, is specific to the frequency of each of the various relevant
atomic transition : it depends in a complex manner from the bulk material
properties, and can exhibit resonances connected to the surface polariton
modes. We list here the surface resonances for about a hundred of optical
windows whose bulk properties are currently tabulated. The study concentrates
on the infrared domain because it is the most relevant for atom-surface
interaction. Aside from this tabulation, we discuss simple hints to estimate
the position of surface resonances, and how uncertainties in the bulk data for
the material dramatically affect the predictions for the image coefficient. We
also evaluate the contribution of UV resonances of the material to the non
resonant part of the image coefficient.",0601196v1
2006-09-08,Photorecombination of berylliumlike Ti18+: Hyperfine quenching of dielectronic resonances,"The photorecombination spectrum of 48Ti18+ was measured employing the merged
electron-ion beams technique at a heavy-ion storage ring. The experimental
electron-ion collision energy range 0-80 eV comprises all dielectronic
recombination (DR) resonances associated with 2s->2p (Delta N =0) core
excitations as well as trielectronic recombination (TR) resonances that involve
2s2->2p2 core double-excitations. At low collision energies DR resonances are
observed that are associated with the excitation of metastable 2s2p 3P0 primary
ions with nearly infinite lifetime for the isotope 48Ti with zero nuclear spin.
For the isotope 47Ti with nonzero nuclear spin hyperfine quenching of these
resonances occurs. The procedure for obtaining the associated time constant
from a recombination measurement is outlined.",0609072v1
2007-03-08,Enhanced transmission through arrays of subwavelength holes in gold films coated by a finite dielectric layer,"Enhanced transmissions through a gold film with arrays of subwavelength holes
are theoretically studied, employing the rigid full vectorial three dimensional
finite difference time domain method. Influence of air-holes shape to the
transmission is firstly studied, which confirms two different resonances
attributing to the enhanced transmission: the localized waveguide resonance and
periodic surface plasmon resonances. For the film coated with dielectric
layers, calculated results show that in the wavelength region of interest the
localized waveguide resonant mode attributes to sensing rather than the
periodic gold-glass surface plasmon mode. Although the detected peak is fairly
broad and the shift is not too pronounced, we emphasize the contribution for
sensing from the localized waveguide resonant mode, which may opens up new ways
to design surface plasmon based sensors.",0703092v1
2004-09-01,A neural mechanism for binaural pitch perception via ghost stochastic resonance,"We present a physiologically plausible binaural mechanism for the perception
of the pitch of complex sounds via ghost stochastic resonance. In this scheme,
two neurons are driven by noise and different periodic signal each (with
frequencies f1=kf0 and f2=(k+1)f0, where k>1), and their outputs (plus noise)
are applied synaptically to a third neuron. Our numerical results, using the
Morris-Lecar neuron model with chemical synapses explicity considered, show
that intermediate noise levels enhance the response of the third neuron at
frequencies close to f0, as in the cases previously described of ghost
resonance. For the case of inharmonic combinations of inputs (both frequencies
shifted by the same amount Df) noise is also seen to enhance the response of
the third neuron at a frequency fr with also shift linearly with Df. In
addition, we show that similar resonances can be observed as a function of the
synaptic time constant. The suggested ghost-resonance-based stochastic
mechanism can thus arise either at the peripheral level or at a higher level of
neural processing in the perception of the pitch",0409004v2
2002-03-25,Field quantization for open optical cavities,"We study the quantum properties of the electromagnetic field in optical
cavities coupled to an arbitrary number of escape channels. We consider both
inhomogeneous dielectric resonators with a scalar dielectric constant
$\epsilon({\bf r})$ and cavities defined by mirrors of arbitrary shape. Using
the Feshbach projector technique we quantize the field in terms of a set of
resonator and bath modes. We rigorously show that the field Hamiltonian reduces
to the system--and--bath Hamiltonian of quantum optics. The field dynamics is
investigated using the input--output theory of Gardiner and Collet. In the case
of strong coupling to the external radiation field we find spectrally
overlapping resonator modes. The mode dynamics is coupled due to the damping
and noise inflicted by the external field. For wave chaotic resonators the mode
dynamics is determined by a non--Hermitean random matrix. Upon including an
amplifying medium, our dynamics of open-resonator modes may serve as a starting
point for a quantum theory of random lasing.",0203122v2
2002-12-30,Stochastic resonance in periodic potentials: realization in a dissipative optical lattice,"We have observed the phenomenon of stochastic resonance on the Brillouin
propagation modes of a dissipative optical lattice. Such a mode has been
excited by applying a moving potential modulation with phase velocity equal to
the velocity of the mode. Its amplitude has been characterized by the
center-of-mass (CM) velocity of the atomic cloud. At Brillouin resonance, we
studied the CM-velocity as a function of the optical pumping rate at a given
depth of the potential wells. We have observed a resonant dependence of the CM
velocity on the optical pumping rate, corresponding to the noise strength. This
corresponds to the experimental observation of stochastic resonance in a
periodic potential in the low-damping regime.",0212156v1
2003-12-09,Quantum averaging and resonances: two-level atom in a one-mode quantized field,"We construct a non-perturbative approach based on quantum averaging combined
with resonant transformations to detect the resonances of a given Hamiltonian
and to treat them. This approach, that generalizes the rotating-wave
approximation, takes into account the resonances at low field and also at high
field (non-linear resonances). This allows to derive effective Hamiltonians
that contain the qualitative features of the spectrum, i.e. crossings and
avoided crossings, as a function of the coupling constant. At a second stage
the precision of the spectrum can be improved quantitatively by standard
perturbative methods like contact transformations. We illustrate this method to
determine the spectrum of a two-level atom interacting with a single mode of a
quantized field.",0312077v1
2004-01-26,Observation of Robust Quantum Resonance Peaks in an Atom Optics Kicked Rotor with Amplitude Noise,"The effect of pulse train noise on the quantum resonance peaks of the Atom
Optics Kicked Rotor is investigated experimentally. Quantum resonance peaks in
the late time mean energy of the atoms are found to be surprisingly robust
against all levels of noise applied to the kicking amplitude, whilst even small
levels of noise on the kicking period lead to their destruction. The robustness
to amplitude noise of the resonance peak and of the fall--off in mean energy to
either side of this peak are explained in terms of the occurence of stable,
$\epsilon$--classical dynamics [S. Wimberger, I. Guarneri, and S. Fishman,
\textit{Nonlin.} \textbf{16}, 1381 (2003)] around each quantum resonance.",0401161v2
2004-03-19,The effect of parallel static and microwave electric fields on excited hydrogen atoms,"Motivated by recent experiments we analyse the classical dynamics of a
hydrogen atom in parallel static and microwave electric fields. Using an
appropriate representation and averaging approximations we show that resonant
ionisation is controlled by a separatrix, and provide necessary conditions for
a dynamical resonance to affect the ionisation probability.
  The position of the dynamical resonance is computed using a high-order
perturbation series, and estimate its radius of convergence. We show that the
position of the dynamical resonance does not coincide precisely with the
ionisation maxima, and that the field switch-on time can dramatically affect
the ionisation signal which, for long switch times, reflects the shape of an
incipient homoclinic. Similarly, the resonance ionisation time can reflect the
time-scale of the separatrix motion, which is therefore longer than
conventional static field Stark ionisation. We explain why these effects should
be observed in the quantum dynamics.
  PACs: 32.80.Rm, 33.40.+f, 34.10.+x, 05.45.Ac, 05.45.Mt",0403139v1
2004-07-15,Superconducting Phase Qubit Coupled to a Nanomechanical Resonator: Beyond the Rotating-Wave Approximation,"We consider a simple model of a Josephson junction phase qubit coupled to a
solid-state nanoelectromechanical resonator. This and many related
qubit-resonator models are analogous to an atom in an electromagnetic cavity.
When the systems are weakly coupled and nearly resonant, the dynamics is
accurately described by the rotating-wave approximation (RWA) or the
Jaynes-Cummings model of quantum optics. However, the desire to develop faster
quantum-information-processing protocols necessitates approximate, yet analytic
descriptions that are valid for more strongly coupled qubit-resonator systems.
Here we present a simple theoretical technique, using a basis of dressed
states, to perturbatively account for the leading-order corrections to the RWA.
By comparison with exact numerical results, we demonstrate that the method is
accurate for moderately strong coupling, and provides a useful theoretical tool
for describing fast quantum information processing. The method applies to any
quantum two-level system linearly coupled to a harmonic oscillator or
single-mode boson field.",0407106v1
2004-07-16,Rigorous derivation of coherent resonant tunneling time and velocity in finite periodic systems,"The velocity $v_{res}$ of resonant tunneling electrons in finite periodic
structures is analytically calculated in two ways. The first method is based on
the fact that a transmission of unity leads to a coincidence of all still
competing tunneling time definitions. Thus, having an indisputable resonant
tunneling time $\tau_{res},$ we apply the natural definition
$v_{res}=L/\tau_{res}$ to calculate the velocity. For the second method we
combine Bloch's theorem with the transfer matrix approach to decompose the wave
function into two Bloch waves. Then the expectation value of the velocity is
calculated. Both different approaches lead to the same result, showing their
physical equivalence. The obtained resonant tunneling velocity $v_{res}$ is
smaller or equal to the group velocity times the magnitude of the complex
transmission amplitude of the unit cell. Only at energies where the unit cell
of the periodic structure has a transmission of unity $v_{res}$ equals the
group velocity. Numerical calculations for a GaAs/AlGaAs superlattice are
performed. For typical parameters the resonant velocity is below one third of
the group velocity.",0407134v1
2004-10-01,Electromagnetically induced absorption and transparency in magneto-optical resonances in elliptically polarized field,"Using a 1 to 2 transition as an analytically tractable model, we discuss in
detail magneto-optical resonances of both EIA (electromagnetically induced
absorption) and EIT (electromagnetically induced transparency) types in the
Hanle configuration. The analysis is made for arbitrary rate of depolarizing
collisions in the excited state and arbitrary elliptical field polarization.
The obtained results clearly show that the main reason for the EIA sub-natural
resonance is the spontaneous transfer of anisotropy from the excited level to
the ground one. In the EIA case we predict the negative structures in the
absortpion resonance at large field detuning. The role of the finite atom-light
interaction time is briefly discussed. In addition we study non-trivial
peculiarities of the resonance lineshape related to the velocity spread in a
gas.",0410011v3
2004-12-01,Gravity-induced resonances in a rotating trap,"It is shown that in an anisotropic harmonic trap that rotates with the
properly chosen rotation rate, the force of gravity leads to a resonant
behavior. Full analysis of the dynamics in an anisotropic, rotating trap in 3D
is presented and several regions of stability are identified. On resonance, the
oscillation amplitude of a single particle, or of the center of mass of a
many-particle system (for example, BEC), grows linearly with time and all
particles are expelled from the trap. The resonances can only occur when the
rotation axis is tilted away from the vertical position. The positions of the
resonances (there are always two of them) do not depend on the mass but only on
the characteristic frequencies of the trap and on the direction of the angular
velocity of rotation.",0412004v2
2007-02-05,Two-level systems driven by large-amplitude fields,"We analyze the dynamics of a two-level system subject to driving by
large-amplitude external fields, focusing on the resonance properties in the
case of driving around the region of avoided level crossing. In particular, we
consider three main questions that characterize resonance dynamics: (1) the
resonance condition, (2) the frequency of the resulting oscillations on
resonance and (3) the width of the resonance. We identify the regions of
validity of different approximations. In a large region of the parameter space,
we use a geometric picture in order to obtain both a simple understanding of
the dynamics and quantitative results. The geometric approach is obtained by
dividing the evolution into discrete time steps, with each time step described
by either a phase shift on the basis states or a coherent mixing process
corresponding to a Landau-Zener crossing. We compare the results of the
geometric picture with those of a rotating-wave approximation. We also comment
briefly on the prospects of employing strong driving as a useful tool to
manipulate two-level systems.",0702032v3
2007-02-06,Resonance fluorescence of a cold atom in a high-finesse resonator,"We study the spectra of emission of a system composed by an atom, tightly
confined inside a high-finesse resonator, when the atom is driven by a laser
and is at steady state of the cooling dynamics induced by laser and cavity
field. In general, the spectrum of resonance fluorescence and the spectrum at
the cavity output contain complementary information about the dynamics
undergone by the system. In certain parameter regimes, quantum interference
effects between the scattering processes induced by cavity and laser field lead
to the selective suppression of features of the resonance fluorescence
spectrum, which are otherwise visible in the spectrum of laser-cooled atoms in
free space.",0702053v2
2007-04-19,Cooling of a Micro-mechanical Resonator by the Back-action of Lorentz Force,"Using a semi-classical approach, we describe an on-chip cooling protocol for
a micro-mechanical resonator by employing a superconducting flux qubit. A
Lorentz force, generated by the passive back-action of the resonator's
displacement, can cool down the thermal motion of the mechanical resonator by
applying an appropriate microwave drive to the qubit. We show that this onchip
cooling protocol, with well-controlled cooling power and a tunable response
time of passive back-action, can be highly efficient. With feasible
experimental parameters, the effective mode temperature of a resonator could be
cooled down by several orders of magnitude.",0704.2462v5
2007-04-20,Resonant relaxation near a massive black hole: the dependence on eccentricity,"The orbits of stars close to a massive black hole are nearly Keplerian
ellipses. Such orbits exert long term torques on each other, which lead to an
enhanced angular momentum relaxation known as resonant relaxation. Under
certain conditions, this process can modify the angular momentum distribution
and affect the interaction rates of the stars with the massive black hole more
efficiently than non-resonant relaxation. The torque on an orbit exerted by the
cluster depends on the eccentricity of the orbit. In this paper, we calculate
this dependence and determine the resonant relaxation timescale as a function
of eccentricity. In particular, we show that the component of the torque that
changes the magnitude of the angular momentum is linearly proportional to
eccentricity, so resonant relaxation is much more efficient on eccentric orbits
than on circular orbits.",0704.2709v1
2007-04-27,Electroproduction of kaons from the proton in a Regge-plus-resonance approach,"We present a Regge-plus-resonance (RPR) description of the p(e,e'K^+)Y
processes (Y=\Lambda,\Sigma^0) in the resonance region. The background
contributions to the RPR amplitude are constrained by the high-energy p(\gamma,
K^+)Y data. As a result, the number of free model parameters in the resonance
region is considerably reduced compared to typical effective-Lagrangian
approaches. We compare a selection of RPR model variants, originally
constructed to describe $KY$ photoproduction, with the world electroproduction
database. The electromagnetic form factors of the intermediate N^*s and
$\Delta^*s are computed in the Bonn constituent-quark model. With this input,
we find a reasonable description of the p(e,e'K^+)Y data without adding or
readjusting any parameters. It is demonstrated that the electroproduction
response functions are extremely useful for fine-tuning both the background and
resonant contributions to the reaction dynamics.",0704.3691v2
2007-05-30,Temperature dependence of the impurity-induced resonant state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+δ}$ by Scanning Tunneling Spectroscopy,"We report on the temperature dependence of the impurity-induced resonant
state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+\delta}$ by scanning tunneling
spectroscopy at 30 mK < T < 52 K. It is known that a Zn impurity induces a
sharp resonant peak in tunnel spectrum at an energy close to the Fermi level.
We observed that the resonant peak survives up to 52 K. The peak broadens with
increasing temperature, which is explained by the thermal effect. This result
provides information to understand the origin of the resonant peak.",0705.4386v2
2007-06-05,Resonance Production in Jet,"Hadronic resonances with short life times and strong coupling to the dense
medium may exhibit mass shifts and width broadening as signatures of chiral
symmetry restoration at the phase transition between hadronic and partonic
matter. Resonances with different lifetimes are also used to extract
information about the time evolution and temperature of the expanding hadronic
medium. In order to collect information about the early stage (at the phase
transition) of a heavy-ion collision, resonances and decay particles which are
unaffected by the hadronic medium have to be used. We explore a possible new
technique to extract signals from the early stage through the selection of
resonances from jets. A first attempt of this analysis, using the reconstructed
$\phi$(1020) from 200 GeV Au+Au collisions in STAR, is presented.",0706.0724v1
2007-06-06,Resonant Scattering of Ultracold Atoms in Low Dimensions,"Low energy scattering amplitudes for two atoms in one- and two-dimensional
atomic wave guides are derived for short range isotropic and resonant
interactions in high partial wave channels. Taking into account the finite
width of the resonance which was neglected in previous works is shown to have
important implications in the properties of the confinement induced resonances.
For spin polarized fermions in quasi-1D wave guides it imposes a strong
constraint on the atomic density for achieving the Fermi Tonks Girardeau gas.
For a planar wave guide, the charateristics of the 2D induced scattering
resonances in $p$- and d-wave are determined as a function of the 3D scattering
parameters and of the wave guide frequency.",0706.0834v3
2007-06-15,Carrier-carrier entanglement and transport resonances in semiconductor quantum dots,"We study theoretically the entanglement created in a scattering between an
electron, incoming from a source lead, and another electron bound in the ground
state of a quantum dot, connected to two leads. We analyze the role played by
the different kinds of resonances in the transmission spectra and by the number
of scattering channels, into the amount of quantum correlations between the two
identical carriers. It is shown that the entanglement between their energy
states is not sensitive to the presence of Breit-Wigner resonances, while it
presents a peculiar behavior in correspondence of Fano peaks: two close maxima
separated by a minimum, for a two-channel scattering, a single maximum for a
multi-channel scattering. Such a behavior is ascribed to the different
mechanisms characterizing the two types of resonances. Our results suggest that
the production and detection of entanglement in quantum dot structures may be
controlled by the manipulation of Fano resonances through external fields.",0706.2312v1
2007-06-19,Barrier transmission for the one-dimensional nonlinear Schrödinger equation: resonances and transmission profiles,"The stationary nonlinear Schr\""odinger equation (or Gross-Pitaevskii
equation) for one-dimensional potential scattering is studied. The nonlinear
transmission function shows a distorted profile, which differs from the
Lorentzian one found in the linear case. This nonlinear profile function is
analyzed and related to Siegert type complex resonances. It is shown, that the
characteristic nonlinear profile function can be conveniently described in
terms of skeleton functions depending on a few instructive parameters. These
skeleton functions also determine the decay behavior of the underlying
resonance state. Furthermore we extend the Siegert method for calculating
resonances, which provides a convenient recipe for calculating nonlinear
resonances. Applications to a double Gaussian barrier and a square well
potential illustrate our analysis.",0706.2826v2
2007-06-26,Resonant and Near-Resonant Internal Wave Interactions,"We report evaluations of a resonant kinetic equation that suggest the slow
time evolution of the Garrett and Munk spectrum is {\em not}, in fact, slow.
Instead nonlinear transfers lead to evolution time scales that are smaller than
one wave period at high vertical wavenumber. Such values of the transfer rates
are inconsistent with conventional wisdom that regards the Garrett and Munk
spectrum as an approximate stationary state and puts the self-consistency of a
resonant kinetic equation at a serious risk. We explore possible reasons for
and resolutions of this paradox. Inclusion of near-resonant interactions
decreases the rate at which the spectrum evolves. This leads to improved
self-consistency of the kinetic equation.",0706.3712v4
2007-07-20,Resonant excitonic emission of a single quantum dot in the Rabi regime,"We report on coherent resonant emission of the fundamental exciton state in a
single semiconductor GaAs quantum dot. Resonant regime with picoseconde laser
excitation is realized by embedding the quantum dots in a waveguiding
structure. As the pulse intensity is increased, Rabi oscillation is observed up
to three periods. The Rabi regime is achieved owing to an enhanced light-matter
coupling in the waveguide. This is due to a \emph{slow light effect}
($c/v_{g}\simeq 3000$), occuring when an intense resonant pulse propagates in a
medium. The resonant control of the quantum dot fundamental transition opens
new possibilities in quantum state manipulation and quantum optics experiments
in condensed matter physics.",0707.3061v1
2007-08-02,Dual-Frequency Resonance-Tracking Atomic Force Microscopy,"A dual-excitation method for resonant-frequency tracking in scanning probe
microscopy based on amplitude detection is developed. This method allows the
cantilever to be operated at or near resonance for techniques where standard
phase locked loops are not possible. This includes techniques with non-acoustic
driving where the phase of the driving force is frequency and/or position
dependent. An example of the later is Piezoresponse Force Microscopy (PFM),
where the resonant frequency of the cantilever is strongly dependent on the
contact stiffness of the tip-surface junction and the local mechanical
properties, but the spatial variability of the drive phase rules out the use of
a phase locked loop. Combined with high-voltage switching and imaging,
dual-frequency, resonance-tracking PFM allows reliable studies of
electromechanical and elastic properties and polarization dynamics in a broad
range of inorganic and biological systems, and is illustrated using lead
zirconate-titanate, rat tail collagen, and native and switched ferroelectric
domains in lithium niobate.",0708.0424v1
2007-08-14,Triplet spin resonance of the Haldane compound with interchain coupling,"Spin resonance absorption of the triplet excitations is studied
experimentally in the Haldane magnet PbNi2V2O8. The spectrum has features of
spin S=1 resonance in a crystal field, with all three components, corresponding
to transitions between spin sublevels, being observable. The resonance field is
temperature dependent, indicating the renormalization of excitation spectrum in
interaction between the triplets. Magnetic resonance frequencies and critical
fields of the magnetization curve are consistent with a boson version of the
macroscopic field theory [Affleck 1992, Farutin & Marchenko 2007], implying the
field induced ordering at the critical field, while contradict the previously
used approach of noninteracting spin chains.",0708.1904v1
2007-08-26,Structure of the Roper Resonance with Diquark Correlations,"We study electromagnetic properties of the nucleon and Roper resonance in a
chiral quark-diquark model including two kinds of diquarks needed to describe
the nucleon: scalar and axial-vector diquarks. The nucleon and Roper resonance
are described as superpositions of two quark-diquark bound states of a quark
and a scalar diquark and of a quark and an axial-vector diquark.
Electromagnetic form factors of the nucleon and Roper resonance are obtained
from one-loop diagrams where the quark and diquarks are coupled by a photon. We
include the effects of intrinsic properties of the diquarks: the intrinsic form
factors both of the diquarks and the anomalous magnetic moment of the
axial-vector diquark. The electric form factors of the proton and neutron
reasonably agree with the experiments due to the inclusions of the diquark
sizes, while the magnetic moments become smaller than the experimental values
because of the scalar dominance in the nucleon. The charge radii of the Roper
resonance are almost comparable with those of the nucleon.",0708.3471v1
2007-09-16,Resonant Excitation of Disk Oscillations in Deformed Disks II: A Model of High Frequency QPOs,"The amplification of disk oscillations resulting from nonlinear resonant
couplings between the oscillations and a disk deformation is examined. The disk
is geometrically thin and general relativistic with a non-rotating central
source. A Lagrangian formulation is adopted. The author examined the same
problem a few years ago, but here we derive a general stability criterion in a
more perspective way. Another distinct point from the previous work is that in
addition to the case where the deformation is a warp, the case where the
deformation is a one-armed pattern symmetric with respect to the equatorial
plane is considered. The results obtained show that in addition to the previous
results that the inertial-acoustic mode and g-mode oscillations are amplified
by horizontal resonance in warped disks, they also amplified by horizontal
resonance in disks deformed by one-armed pattern symmetric with respect to the
equatorial plane. If we consider local oscillations that are localized around
boundaries of their propagation region, the resonance occurs at $4r_{\rm g}$,
where $r_{\rm g}$ is the Schwarzschild radius. If nonlocal oscillations are
considered, frequency ranges of oscillations where oscillations are resonantly
amplified are specified.",0709.2467v1
2007-09-28,Feshbach resonances in mixtures of ultracold $^6$Li and $^{87}$Rb gases,"We report on the observation of two Feshbach resonances in collisions between
ultracold $^6$Li and $^{87}$Rb atoms in their respective hyperfine ground
states $|F,m_F>=|1/2,1/2>$ and $|1,1>$. The resonances show up as trap losses
for the $^6$Li cloud induced by inelastic Li-Rb-Rb three-body collisions. The
magnetic field values where they occur represent important benchmarks for an
accurate determination of the interspecies interaction potentials. A broad
Feshbach resonance located at 1066.92 G opens interesting prospects for the
creation of ultracold heteronuclear molecules. We furthermore observe a strong
enhancement of the narrow p-wave Feshbach resonance in collisions of $^6$Li
atoms at 158.55 G in the presence of a dense $^{87}$Rb cloud. The effect of the
$^{87}$Rb cloud is to introduce Li-Li-Rb three-body collisions occurring at a
higher rate than Li-Li-Li collisions.",0709.4554v2
2007-10-06,Resonant ratcheting of a Bose-Einstein condensate,"We study the rectification process of interacting quantum particles in a
periodic potential exposed to the action of an external ac driving. The
breaking of spatio-temporal symmetries leads to directed motion already in the
absence of interactions. A hallmark of quantum ratcheting is the appearance of
resonant enhancement of the current (Europhys. Lett. 79 (2007) 10007 and Phys.
Rev. A 75 (2007) 063424). Here we study the fate of these resonances within a
Gross-Pitaevskii equation which describes a mean field interaction between many
particles. We find, that the resonance is i) not destroyed by interactions, ii)
shifting its location with increasing interaction strength. We trace the
Floquet states of the linear equations into the nonlinear domain, and show that
the resonance gives rise to an instability and thus to the appearance of new
nonlinear Floquet states, whose transport properties differ strongly as
compared to the case of noninteracting particles.",0710.1339v1
2007-10-16,Resonances of 7He in the complex scaling method,"We study the resonance spectroscopy of 7He in the 4He+n+n+n cluster model,
where the motion of valence neutrons is described in the cluster orbital shell
model. Many-body resonances are treated on the correct boundary condition as
the Gamow states in the complex scaling method. We obtain five resonances and
investigate their properties from the configurations. In particular, the 1/2-
state is found in a low excitation energy of 1.1 MeV with a width of 2.2 MeV,
while the experimental determination of the position of this state is not so
clear. We also evaluate the spectroscopic factors of the 6He-n components in
the obtained 7He resonances. The importance of the 6He(2+) state is shown in
several states of 7He.",0710.2945v1
2007-11-09,A Digital Switch and Femto-Tesla Magnetic Field Sensor Based on Fano Resonance in a Spin Field Effect Transistor,"We show that a Spin Field Effect Transistor, realized with a semiconductor
quantum wire channel sandwiched between half-metallic ferromagnetic contacts,
can have Fano resonances in the transmission spectrum. These resonances appear
because the ferromagnets are half-metallic, so that the Fermi level can be
placed above the majority but below the minority spin band. In that case, the
majority spins will be propagating, but the minority spins will be evanescent.
At low temperatures, the Fano resonances can be exploited to implement a
digital binary switch that can be turned on or off with a very small gate
voltage swing of few tens of microvolts, leading to extremely small dynamic
power dissipation during switching. An array of 500,000 x 500,000 such
transistors can detect ultrasmall changes in a magnetic field with a
sensitivity of 1 femto-Tesla/sqrt{Hz}, if each transistor is biased near a Fano
resonance.",0711.1475v1
2007-11-09,Resonant Phonon Scattering in Quantum Hall Systems Driven by dc Electric Fields,"Using dc excitation to spatially tilt Landau levels, we study resonant
acoustic phonon scattering in two-dimensional electron systems. We observe that
dc electric field strongly modifies phonon resonances, transforming resistance
maxima into minima and back into maxima. Further, phonon resonances are
enhanced dramatically in the non-linear dc response and can be detected even at
low temperatures. Most of our observations can be explained in terms of
dc-induced (de)tuning of the resonant acoustic phonon scattering and its
interplay with intra-Landau level impurity scattering. Finally, we observe a
dc-induced zero-differential resistance state and a resistance maximum which
occurs when the electron drift velocity approaches the speed of sound.",0711.1547v1
2007-12-03,Finite size effects on spin-torque driven ferromagnetic resonance in spin-valves with a Co/Ni synthetic free layer,"Spin-torque driven ferromagnetic resonance (ST-FMR) is used to study magnetic
excitations in Co/Ni synthetic layers confined in nanojunctions. Field swept
ST-FMR measurements were conducted with a magnetic field applied perpendicular
to the layer surface. The resonance lines were measured under low amplitude
excitation in a linear response regime. The resulting resonance fields were
compared with those obtained using conventional rf field driven FMR on extended
films with the same Co/Ni layer structure. A lower resonance field is found in
confined structures. The effect of both dipolar fields acting on the Co/Ni
layer emanating from other magnetic layers in the device and finite size
effects on the spin wave spectrum are discussed.",0712.0404v2
2007-12-13,Analytic models of ultra-cold atomic collisions at negative energies for application to confinement-induced resonances,"We construct simple analytic models of the $S$-matrix, accounting for both
scattering resonances and smooth background contributions for collisions that
occur below the s-wave threshold. Such models are important for studying
confinement-induced resonances such as those occurring in cold collisions of
$^{133}$Cs atoms in separated sites of a polarization-gradient optical lattice.
Because these resonances occur at negative energy with respect to the s-wave
threshold, they cannot be studied easily using direct numerical solutions of
the Schr\""{o}dinger equation. Using our analytic model, we extend previous
studies of negative-energy scattering to the multichannel case, accounting for
the interplay of Feshbach resonances, large background scattering lengths, and
inelastic processes.",0712.2070v2
2007-12-19,Mechanical detection of carbon nanotube resonator vibrations,"Bending-mode vibrations of carbon nanotube resonator devices were
mechanically detected in air at atmospheric pressure by means of a novel
scanning force microscopy method. The fundamental and higher order bending
eigenmodes were imaged at up to 3.1GHz with sub-nanometer resolution in
vibration amplitude. The resonance frequency and the eigenmode shape of
multi-wall nanotubes are consistent with the elastic beam theory for a doubly
clamped beam. For single-wall nanotubes, however, resonance frequencies are
significantly shifted, which is attributed to fabrication generating, for
example, slack. The effect of slack is studied by pulling down the tube with
the tip, which drastically reduces the resonance frequency.",0712.3196v1
2007-12-21,On gravitational-electromagnetic resonance,"This is an English translation of the paper M.B.Mensky, in: K.P.Stanyukovich
(ed.), ""Problems of Theory of Gravity and Elementary Particles"", issue 6,
Moscow, Atomizdat, 1975, p.181-190 (in Russian). This paper elaborates further
the idea (formulated in 1971 by Braginsky and Mensky) of detecting
high-frequency gravitational waves by observing resonance action of a
gravitational wave on the electromagnetic wave in a closed resonator
(waveguide). The phenomenon underlying such a detector was called
gravitational-electromagnetic resonance (GER). In the present paper both closed
(for example circular) resonator or waveguide and long (for example in the
shape of a spiral) waveguide are considered as possible gravitational-wave
detectors. High-frequency gravitational-wave detectors are now again actual
(see A.M.Cruise and R.M.J.Ingley, Class. Quant. Grav. 22, S479, 2005), but the
current literature on this topic does not cover all the issues discussed in the
present paper.",0712.3721v1
2008-01-02,Hadronic resonance production in $d$+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV at RHIC,"We present the first measurements of the $\rho(770)^0$, $K^*$(892),
$\Delta$(1232)$^{++}$, $\Sigma$(1385), and $\Lambda$(1520) resonances in $d$+Au
collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV, reconstructed via their hadronic
decay channels using the STAR detector at RHIC. The masses and widths of these
resonances are studied as a function of transverse momentum ($p_T$). We observe
that the resonance spectra follow a generalized scaling law with the transverse
mass ($m_T$). The $<p_T>$ of resonances in minimum bias collisions is compared
to the $<p_T>$ of $\pi$, $K$, and $\bar{p}$. The $\rho^0/\pi^-$, $K^*/K^-$,
$\Delta^{++}/p$, $\Sigma(1385)/\Lambda$, and $\Lambda(1520)/\Lambda$ ratios in
$d$+Au collisions are compared to the measurements in minimum bias $p+p$
interactions, where we observe that both measurements are comparable. The
nuclear modification factors ($R_{dAu}$) of the $\rho^0$, $K^*$, and $\Sigma^*$
scale with the number of binary collisions ($N_{bin}$) for $p_T >$ 1.2 GeV/$c$.",0801.0450v2
2008-01-04,Phase separation and collapse in Bose-Fermi mixtures with a Feshbach resonance,"We consider a mixture of single-component bosonic and fermionic atoms with an
interspecies interaction that is varied using a Feshbach resonance. By
performing a mean-field analysis of a two-channel model, which describes both
narrow and broad Feshbach resonances, we find an unexpectedly rich phase
diagram at zero temperature: Bose-condensed and non-Bose-condensed phases form
a variety of phase-separated states that are accompanied by both critical and
tricritical points. We discuss the implications of our results for the
experimentally observed collapse of Bose-Fermi mixtures on the attractive side
of the Feshbach resonance, and we make predictions for future experiments on
Bose-Fermi mixtures close to a Feshbach resonance.",0801.0635v2
2008-01-15,Long-range potentials and $(n-1)d+ns$ molecular resonances in an ultracold rydberg gas,"We have calculated long-range molecular potentials of the $0_g^{+}$,
$0_u^{-}$ and $1_u$ symmetries between highly-excited rubidium atoms. Strong
$np+np$ potentials characterized by these symmetries are important in
describing interaction-induced phenomena in the excitation spectra of high $np$
Rydberg states. Long-range molecular resonances are such phenomena and they
were first reported in S.M. Farooqi {\it et al.}, Phys. Rev. Lett. {\bf 91}
183002. One class of these resonances occurs at energies corresponding to
excited atom pairs $(n-1)d+ns$. Such resonances are attributed to $\ell$-mixing
due to Rydberg-Rydberg interactions so that otherwise forbidden molecular
transitions become allowed. We calculate molecular potentials in Hund's case
(c), use them to find the resonance lineshape and compare to experimental
results.",0801.2386v1
2008-01-23,Photon-assistant Fano resonance in coupled multiple quantum dots,"Based on calculations of the electronic structure of coupled multiple quantum
dots, we study systemically the transport properties of the system driven by an
ac electric field. We find qualitative difference between transport properties
of double coupled quantum dots (DQDs) and triple quantum dots. For both
symmetrical and asymmetrical configurations of coupled DQDs, the field can
induce the photon-assisted Fano resonances in current-AC frequency curve in
parallel DQDs, and a symmetric resonance in serial DQDs. For serially coupled
triple quantum dots(STQDs), it is found that the $\Lambda$-type energy level
has remarkable impact on the transport properties. For an asymmetric (between
left and right dots) configuration, there is a symmetric peak due to resonant
photon induced mixing between left/right dot and middle dot. In the symmetric
configuration, a Fano asymmetric line shape appears with the help of ``trapping
dark state"". Here the interesting coherent trapping phenomena, which usual
appear in quantum optics, play an essential role in quantum electronic
transport. We provide a clear physics picture for the Fano resonance and
convenient ways to tune the Fano effects.",0801.3515v1
2008-01-30,"Polarized Structure Function $σ_{LT'}$ for $p({\vec e},e'K^+)Λ$ in the Nucleon Resonance Region","The first measurements of the polarized structure function $\sigma_{LT'}$ for
the reaction $p(\vec e,e'K^+)\Lambda$ in the nucleon resonance region are
reported. Measurements are included from threshold up to $W$=2.05 GeV for
central values of $Q^2$ of 0.65 and 1.00 GeV$^2$, and nearly the entire kaon
center-of-mass angular range. $\sigma_{LT'}$ is the imaginary part of the
longitudinal-transverse response and is expected to be sensitive to
interferences between competing intermediate s-channel resonances, as well as
resonant and non-resonant processes. The results for $\sigma_{LT'}$ are
comparable in magnitude to previously reported results from CLAS for
$\sigma_{LT}$, the real part of the same response. An intriguing sign change in
$\sigma_{LT'}$ is observed in the high $Q^2$ data at $W\approx 1.9$ GeV.
Comparisons to several existing model predictions are shown.",0801.4711v1
2008-01-31,Low temperature electron-phonon resonance in dc-current-biased two-dimensional electron systems,"Effects of resonant acoustic phonon scattering on magnetoresistivity are
examined in two-dimensional electron systems at low temperatures by using a
balance-equation magnetotransport scheme direct controlled by the current. The
experimentally observed resonances in linear resistivity are shown to result
from the conventional bulk phonon modes in a GaAs-based system, without
invoking leaky interface phonons. Due to quick heating of electrons, phonon
resonances can be dramatically enhanced by a finite bias current. When the
electron drift velocity increases to the speed of sound, additional and
prominent phonon resonance peaks begin to emerge. As a result, remarkable
resistance oscillation and negative differential resistivity can appear in
nonlinear transport in a modest mobility sample at low temperatures, which is
in agreement with recent experiments.",0801.4836v2
2008-02-11,Resonances in a circular dielectric cavity,"We study resonance distributions in a circular dielectric cavity. It is shown
that the decay-rate distribution has a peak structure and the details of the
peak are consistent with the classical survival probability time distribution.
We also investigate the behavior of the complex resonance positions at the
small opening limit. At the large $n$ limit, the real part of complex resonance
positions approaches the solutions with different $m$ of Dirichlet problem with
a scale $n^{-2}$ and the imaginary part goes zero as $n^{-2m}$ for TM and
$n^{-2(m+1)}$ for TE polarization, where $m$ is the order of the resonance.",0802.1384v1
2008-02-12,Low-lying dipole resonance in neutron-rich Ne isotopes,"Microscopic structure of the low-lying isovector dipole excitation mode in
neutron-rich $^{26,28,30}$Ne is investigated by performing deformed
quasiparticle-random-phase-approximation (QRPA) calculations. The particle-hole
residual interaction is derived from a Skyrme force through a Landau-Migdal
approximation. We have obtained the low-lying resonance in $^{26}$Ne at around
8.5 MeV. It is found that the isovector dipole strength at $E_{x}<10$ MeV
exhausts about 6.0% of the classical Thomas-Reiche-Kuhn dipole sum rule. This
excitation mode is composed of several QRPA eigenmodes, one is generated by a
$\nu(2s^{-1}_{1/2} 2p_{3/2})$ transition dominantly, and the other mostly by a
$\nu(2s^{-1}_{1/2} 2p_{1/2})$ transition. The neutron excitations take place
outside of the nuclear surface reflecting the spatially extended structure of
the $2s_{1/2}$ wave function. In $^{30}$Ne, the deformation splitting of the
giant resonance is large, and the low-lying resonance is overlapping with the
giant resonance.",0802.1687v1
2008-02-21,Fabrication of MEMS Resonators in Thin SOI,"A simple and fast process for micro-electromechanical (MEM) resonators with
deep sub-micron transduction gaps in thin SOI is presented in this paper. Thin
SOI wafers are important for advanced CMOS technology and thus are evaluated as
resonator substrates for future co-integration with CMOS circuitry on a single
chip. As the transduction capacitance scales with the resonator thickness, it
is important to fabricate deep sub-micron trenches in order to achieve a good
capacitive coupling. Through the combination of conventional UV-lithography and
focused ion beam (FIB) milling the process needs only two lithography steps,
enabling therefore a way for fast prototyping of MEM-resonators. Different FIB
parameters and etching parameters are compared in this paper and their effect
on the process are reported.",0802.3040v1
2008-02-21,Modeling of T-Shaped Microcantilever Resonators,"The extensive research and development of micromechanical resonators is
trying to allow the use of these devices for highly sensitive applications.
Microcantilevers are some of the simplest MEMS structure and had been proved to
be a good platform due to its excellent mechanical properties. A cantilever
working in dynamic mode, adjust its resonance frequency depending on changes in
both the spring constant (k) and mass (m) of the resonator. The aim of this
work was to model a cantilever structure to determine the optimal dimensions in
which the resonance frequency would be a function dominated by mass changes and
not stiffness changes. In order to validate the model a set of microcantilevers
were fabricated and characterized.",0802.3102v1
2008-02-26,Study of $η$ photoproduction on the proton in a chiral constituent quark approach via one-gluon-exchange model,"A formalism based on a chiral quark model ($\chi$QM) approach complemented
with a one-gluon exchange model, to take into account the breakdown of the
$SU(6)\otimes O(3)$ symmetry, is presented. The configuration mixing of wave
functions for nucleon and resonances are derived. % With few adjustable
parameters, differential cross-section and polarized beam asymmetry for the
$\gamma p \to \eta p$ process are calculated and successfully compared with the
data in the centre-of-mass energy range from threshold up to 2 GeV. The known
resonances $S_{11}(1535)$, $S_{11}(1650)$, $P_{13}(1720)$, $D_{13}(1520)$, and
$F_{15}(1680)$, as well as two new $S_{11}$ and $D_{15}$ resonances are found
to be dominant in the reaction mechanism. Besides, connections among the
scattering amplitudes of the $\chi$QM approach and the helicity amplitudes, as
well as decay widths of resonances are established. Possible contributions from
the so-called ""missing resonances"" are investigated and found to be negligible.",0802.3816v1
2008-02-28,Temperature Dependence of the Frequency and Noise of Superconducting Coplanar Waveguide Resonators,"We present measurements of the temperature and power dependence of the
resonance frequency and frequency noise of superconducting niobium thin-film
coplanar waveguide resonators, carried out at temperatures well below the
superconducting transition (T_{c}=9.2 K). The noise decreases by nearly two
orders of magnitude as the temperature is increased from 120 to 1200 mK, while
the variation of the resonance frequency with temperature over this range
agrees well with the standard two-level system (TLS) model for amorphous
dielectrics. These results support the hypothesis that TLS are responsible for
the noise in superconducting microresonators, and have important implications
for resonator applications such as qubits and photon detectors.",0802.4268v1
2008-03-01,Spatial coherence resonance on diffusive and small-world networks of Hodgkin-Huxley neurons,"Spatial coherence resonance in a spatially extended system that is locally
modeled by Hodgkin-Huxley (HH) neurons is studied in this paper. We focus on
the ability of additive temporally and spatially uncorrelated Gaussian noise to
extract a particular spatial frequency of excitatory waves in the medium,
whereby examining also the impact of diffusive and small-world network topology
determining the interactions amongst coupled HH neurons. We show that there
exists an intermediate noise intensity that is able to extract a characteristic
spatial frequency of the system in a resonant manner provided the latter is
diffusively coupled, thus indicating the existence of spatial coherence
resonance. However, as the diffusive topology of the medium is relaxed via the
introduction of shortcut links introducing small-world properties amongst
coupled HH neurons, the ability of additive Gaussian noise to evoke ordered
excitatory waves deteriorates rather spectacularly, leading to the decoherence
of the spatial dynamics and with it related absence of spatial coherence
resonance. In particular, already a minute fraction of shortcut links suffices
to substantially disrupt coherent pattern formation in the examined system.",0803.0070v1
2008-03-03,Resonant spin-changing collisions in spinor Fermi gases,"Spin-changing collisions in trapped Fermi gases may acquire a resonant
character due to the compensation of quadratic Zeeman effect and trap energy.
These resonances are absent in spinor condensates and pseudo-spin-1/2 Fermi
gases, being a characteristic feature of high-spin Fermi gases that allows
spinor physics at large magnetic fields. We analyze these resonances in detail
for the case of lattice spinor fermions, showing that they permit to
selectively target a spin-changing channel while suppressing all others. These
resonances allow for the controlled creation of non-trivial quantum
superpositions of many-particle states with entangled spin and trap degrees of
freedom, which remarkably are magnetic-field insensitive. Finally, we show that
the intersite tunneling may lead to a quantum phase transition described by an
effective quantum Ising model.",0803.0239v1
2008-03-17,Dynamics of Enceladus and Dione inside the 2:1 Mean-Motion Resonance under Tidal Dissipation,"In a previous work (Callegari and Yokoyama 2007, Celest. Mech. Dyn. Astr.
vol. 98), the main features of the motion of the pair Enceladus-Dione were
analyzed in the frozen regime, i.e., without considering the tidal evolution.
Here, the results of a great deal of numerical simulations of a pair of
satellites similar to Enceladus and Dione crossing the 2:1 mean-motion
resonance are shown. The resonance crossing is modeled with a linear tidal
theory, considering a two-degrees-of-freedom model written in the framework of
the general three-body planar problem. The main regimes of motion of the system
during the passage through resonance are studied in detail. We discuss our
results comparing them with classical scenarios of tidal evolution of the
system. We show new scenarios of evolution of the Enceladus-Dione system
through resonance not shown in previous approaches of the problem.",0803.2264v3
2008-03-17,Origin of resonances in the chiral unitary approach,"We study the origin of the resonances associated with pole singularities of
the scattering amplitude in the chiral unitary approach. We propose a ""natural
renormalization"" scheme using the low-energy interaction and the general
principle of the scattering theory. We develop a method to distinguish
dynamically generated resonances from genuine quark states
[Castillejo-Dalitz-Dyson (CDD) poles] using the natural renormalization scheme
and phenomenological fitting. Analyzing physical meson-baryon scatterings, we
find that the Lambda(1405) resonance is largely dominated by the meson-baryon
molecule component. In contrast, the N(1535) resonance requires a sizable CDD
pole contribution, while the effect of the meson-baryon dynamics is also
important.",0803.2550v3
2008-03-23,Resonant interactions of nonlinear water waves in a finite basin,"We study exact four-wave resonances among gravity water waves in a square box
with periodic boundary conditions. We show that these resonant quartets are
linked with each other by shared Fourier modes in such a way that they form
independent clusters. These clusters can be formed by two types of quartets:
(1) {\it angle-resonances} which cannot directly cascade energy but which can
redistribute it among the initially excited modes and (2) {\it
scale-resonances} which are much more rare but which are the only ones that can
transfer energy between different scales. We find such resonant quartets and
their clusters numerically on the set of 1000 x 1000 modes, classify and
quantify them and discuss consequences of the obtained cluster structure for
the wavefield evolution. Finite box effects and associated resonant interaction
among discrete wave modes appear to be important in most numerical and
laboratory experiments on the deep water gravity waves, and our work is aimed
at aiding the interpretation of the experimental and numerical data.",0803.3308v2
2008-03-31,2D skew scattering in the vicinity and away from resonant scattering condition,"We studied the energy dependence of the 2D skew scattering from strong
potential, for which the Born approximation is not applicable. Since the skew
scattering cross section is zero both at low and at high energies, it exhibits
a maximum as a function of energy of incident electron. We found analytically
the shape of the maximum for an exactly solvable model of circular-barrier
potential. Within a rescaling factor, this shape is universal for strong
potentials. If the repulsive potential has an attractive core, the discrete
levels of the core become quasilocal due to degeneracy with continuum. For
energy of incident electron close to the quasilocal state with zero angular
momentum, the enhancement of the net cross section is accompanied by resonant
enhancement of the skew scattering. By contrast, near the resonance with
quasilocal states having momenta $\pm 1$, the skew scattering cross section is
an odd function of energy deviation from the resonance, and passes through
zero, i.e., it exhibits a sign reversal. In the latter case, in the presence of
the Fermi sea, the Kondo resonance manifests itself in strong temperature
dependence of the skew scattering.",0804.0001v1
2008-04-01,Alternating dynamic state in intrinsic Josephson-junction stacks self-generated by internal resonance,"Intrinsic Josephson-junction stacks realized in high-temperature
superconductors provide a very attractive base for developing coherent sources
of electromagnetic radiation in the terahertz frequency range. A promising way
to synchronize phase oscillations in all the junctions is to excite an internal
cavity resonance. We demonstrate that this resonance promotes the formation of
an alternating coherent state, in which the system spontaneously splits into
two subsystems with different phase-oscillation patterns. There is a static
phase shift between the oscillations in the two subsystems which changes from 0
to $2\pi$ in a narrow region near the stack center. The oscillating electric
and magnetic fields are almost homogeneous in all the junctions. The formation
of this state promotes efficient pumping of the energy into the cavity
resonance leading to strong resonance features in the current-voltage
dependence.",0804.0146v1
2008-04-14,"The $e^+e^-\to J/ψD \bar D$, $J/ψD\bar D^*$ reactions with dynamically generated resonances","In two recent reactions by Belle producing $D\bar D$ and $D\bar D^*$ meson
pairs, peaks above threshold have been measured in the differential cross
sections, possibly indicating new resonances in these channels. We want to
study such reactions from the point of view that the $D$ meson pairs are
produced from already known or predicted resonances below threshold. Our study
shows that the peak in the $D\bar D^*$ production is not likely to be caused by
the X(3872) resonance, but the peak seen in $D\bar D$ invariant mass can be
well described if the $D\bar D$ pair comes from the already predicted scalar
X(3700) resonance.",0804.2172v1
2008-04-15,Feedback spin resonance in superconducting CeCu$_2$Si$_2$ and CeCoIn$_5$,"We show that the recently observed spin resonance modes in heavy-fermion
superconductors CeCoIn$_5$ and CeCu$_2$Si$_2$ are magnetic excitons originating
from superconducting quasiparticles. The wave vector ${\bf Q}$ of the resonance
state leads to a powerful criterion for the symmetry and node positions of the
unconventional gap function. The detailed analysis of the superconducting
feedback on magnetic excitations reveals that the symmetry of the
superconducting gap corresponds to a singlet $d_{x^2-y^2}$ state symmetry in
both compounds. In particular this resolves the long-standing ambiguity of the
gap symmetry in CeCoIn$_5$. We demonstrate that in both superconductors the
resonance peak shows a significant dispersion away from ${\bf Q}$ that should
be observed experimentally. Our results suggest a unifying nature of the
resonance peaks in the two heavy-fermion superconductors and in layered
cuprates.",0804.2363v1
2008-04-19,Resonances of low orders in the planetary system of HD37124,"The full set of published radial velocity data (52 measurements from Keck +
58 ones from ELODIE + 17 ones from CORALIE) for the star HD37124 is analysed.
Two families of dynamically stable high-eccentricity orbital solutions for the
planetary system are found. In the first one, the outer planets c and d are
trapped in the 2/1 mean-motion resonance. The second family of solutions
corresponds to the 5/2 mean-motion resonance between these planets. In both
families, the planets are locked in (or close to) an apsidal corotation
resonance. In the case of the 2/1 MMR, it is an asymmetric apsidal corotation
(with the difference between the longitudes of periastra $\Delta\omega\sim
60^\circ$), whereas in the case of the 5/2 MMR it is a symmetric antialigned
one ($\Delta\omega = 180^\circ$).
  It remains also possible that the two outer planets are not trapped in an
orbital resonance. Then their orbital eccentricities should be relatively small
(less than, say, 0.15) and the ratio of their orbital periods is unlikely to
exceed $2.3-2.5$.",0804.3137v2
2008-04-23,Search for ttbar resonances in the lepton plus jets final state in ppbar collisions at sqrt{s}=1.96TeV,"We present a search for a narrow-width heavy resonance decaying into top
quark pairs X->ttbar in ppbar collisions at sqrt{s}=1.96TeV using approximately
0.9fb^-1 of data collected with the D0 detector at the Fermilab Tevatron
Collider. This analysis considers ttbar candidate events in the lepton plus
jets channel with at least one identified b jet and uses the ttbar invariant
mass distribution to search for evidence of resonant production. We find no
evidence for a narrow resonance X decaying to ttbar. Therefore, we set upper
limits on sigma*B(X->ttbar) for different hypothesized resonance masses using a
Bayesian approach. For a Topcolor-assisted technicolor model, the existence of
a leptophobic Z' boson with mass M_Z'<700GeV and width Gamma_Z'=0.012 M_Z' can
be excluded at the 95% C.L.",0804.3664v1
2008-04-24,Decay of an inhomogeneous state via resonant tunnelling,"We recently investigated the nature of resonant tunnelling in standard scalar
Quantum Field Theory, uncovering the conditions required for resonance. It was
shown that whereas the homogeneous false vacuum may decay via bubble
nucleation, it may not decay in a resonant fashion. The no-go theorem given
there is circumvented in this study by considering an initial state other than
the homogeneous false vacuum, and we confirm our mechanism by showing in an
explicit model how resonant tunnelling occurs. Using this model we demonstrate
how the tunnelling rate depends on the energy of specially constructed initial
states, with these states corresponding to contracting spherical bubbles of
some vacuum that evolve to a minimum radius and then tunnel to another vacuum,
instead of the classical motion where the bubble would just start to expand.",0804.3801v1
2008-05-07,On-Chip Hotplate for Temperature Control of Cmos Saw Resonators,"Due to the sensitivity of the piezoelectric layer in surface acoustic wave
(SAW) resonators to temperature, a method of achieving device stability as a
function of temperature is required. This work presents the design, modeling
and characterization of integrated dual-serpentine polysilicon resistors as a
method for temperature control of CMOS SAW resonators. The design employs the
oven control temperature stabilization scheme where the device's temperature is
elevated to higher than Tmax to maintain constant device temperature. The
efficiency of the polysilicon resistor as a heating element was verified
through a 1-D partial differential equation model, 3-D CoventorWare finite
element simulations and measurements using Compix thermal camera. To verify
that the on-chip hotplate is effective as a temperature control method, both DC
and RF measurements of the heater together with the resonator were conducted.
Experimental results have indicated that the TCF of the CMOS SAW resonator of
-97.2 ppm/deg C has been reduced to -23.19 ppm/deg C when heated to 56 deg C.",0805.0930v1
2008-05-13,On the long-term tidal evolution of GJ 436b in the presence of a resonant companion,"In order to explain the significant orbital eccentricity of the short-period
transiting Neptune-mass planet GJ 436b and at the same time satisfy various
observational constraints and anomalies, Ribas, Font-Ribera and Beaulieu have
proposed the existence of an eccentric low-mass companion planet at the
position of the outer 2:1 resonance. The authors demonstrate the viability of
their proposal using point-mass three-body integrations, arguing that as long
as the system appears to be dynamically stable, the short-term secular
variations ought to dominate the long-term dissipative evolution. Here we
demonstrate that if one includes tidal dissipation, both orbits circularize
after a few times the circularization timescale of the inner planet. We
conclude that with or without a nearby companion planet, in or out of the 2:1
resonance, the Q-value of GJ 436b must be near the upper bound estimate for
Neptune if the system is as young as 1 Gyr, and an order of magnitude higher if
the system is as old as 10 Gyr. We show detail of passage through resonance and
conclude that even out of resonance, a companion planet should still be
detectable through transit timing variations.",0805.1928v1
2008-05-14,Weak nonlinear coupling between epicyclic modes in slender tori,"We examine nonlinear oscillations of slender tori in the vicinity of black
holes and compact stars. These tori represent useful probes of the complicated,
nonlinear dynamics of real accretion disks and provide at least qualitative
understanding of their oscillations. We demonstrate that epicyclic modes of
such tori are weakly coupled due to the pressure and gravitational forces. We
explore all possible resonances between two epicyclic modes up to the fourth
order. We show that the strongest resonance between axisymmetric modes is 3:2.
In addition, any resonance between an axisymmetric and a non-axisymmetric mode
is excluded due to axial and equatorial-plane symmetries of the equilibrium
torus. We examine a parametric excitation of vertical axisymmetric oscillations
by radial oscillations in the 3:2 resonance. We show that the resonance may be
significant only for high-amplitude radial oscillations.",0805.2059v1
2008-06-01,Endohedral resonances: modification of atomic photoionization by the fullerenes shell,"We discuss the complicated resonance structure of the endohedral atom
photoionization cross section. Very strong enhancement and interference
patterns in the photoionization cross-section of the valent and subvalent
subshells of noble gas endohedral atoms A@C60 are demonstrated. It is shown
also that the atomic Giant resonance can be either completely destroyed or
remains almost untouched depending on the velocity of photoelectrons that are
emitted in the resonance's decay process. These effects are results of dynamic
modification of the incoming beam of radiation due to polarization of the
fullerenes electron shell and reflection of photoelectrons be the fullerenes
shell static potential. We have considered the outer np- and subvalent
ns-subshells for Ne, Ar, Kr and Xe noble gas atoms. The modification of the
Giant resonances is considered for a whole sequence of endohedrals with atoms
and ions Xe, Ba, La, Ce+, Ce+4, Eu. The polarization of the fullerene shell is
expressed via the total photoabsorption cross section. The photoelectron
reflection from the static potential is taken into account in the frame of the
so-called bubble potential that is a spherical -type potential.",0806.0140v1
2008-06-23,Strong magnetic coupling between an electronic spin qubit and a mechanical resonator,"We describe a technique that enables a strong, coherent coupling between a
single electronic spin qubit associated with a nitrogen-vacancy impurity in
diamond and the quantized motion of a magnetized nano-mechanical resonator tip.
This coupling is achieved via careful preparation of dressed spin states which
are highly sensitive to the motion of the resonator but insensitive to
perturbations from the nuclear spin bath. In combination with optical pumping
techniques, the coherent exchange between spin and motional excitations enables
ground state cooling and the controlled generation of arbitrary quantum
superpositions of resonator states. Optical spin readout techniques provide a
general measurement toolbox for the resonator with quantum limited precision.",0806.3606v1
2008-06-26,Electromagnetically-Induced-Transparency-Like Effect in the Degenerate Triple-Resonant Optical Parametric Amplifier,"We investigate experimentally the absorptive and dispersive properties of
triple-resonant optical parametric amplifier OPA for the degenerate subharmonic
field. In the experiment, the subharmonic field is utilized as the probe field
and the harmonic wave as the pump field. We demonstrate that EIT-like effect
can be simulated in the triple-resonant OPA when the cavity line-width for the
harmonic wave is narrower than that for the subharmonic field. However, this
phenomenon can not be observed in a double-resonant OPA. The narrow
transparency window appears in the reflected field. Especially, in the measured
dispersive spectra of triple-resonant OPA, a very steep variation of the
dispersive profile of the subharmonic field is observed, which can result in a
slow light as that observed in atomic EIT medium.",0806.4218v1
2008-06-27,Atomic Structure of Benzene Which Accounts for Resonance Energy,"Benzene is a hexagonal molecule of six carbon atoms, each of which is bound
to six hydrogen atoms. The equality of all six CC bond lengths, despite the
alternating double and single bonds, and the surplus (resonance) energy, led to
the suggestion of two resonanting structures. Here, the new atomic structure
shows that the bond length equality is due to three carbon atoms with double
bond radii bound to three other carbon atoms with resonance bond radii (as in
graphene). Consequently, there are two kinds of CH bonds of slightly different
lengths. The bond energies account for the resonance energy.",0806.4502v3
2008-08-05,Kerr nonlinearities and nonclassical states with superconducting qubits and nanomechanical resonators,"We propose the use of a superconducting charge qubit capacitively coupled to
two resonant nanomechanical resonators to generate Yurke-Stoler states, i.e.
quantum superpositions of pairs of distinguishable coherent states 180$^\circ$
out of phase with each other. This is achieved by effectively implementing Kerr
nonlinearities induced through application of a strong external driving field
in one of the resonators. A simple study of the effect of dissipation on our
scheme is also presented, and lower bounds of fidelity and purity of the
generated state are calculated. Our procedure to implement a Kerr nonlinearity
in this system may be used for high precision measurements in nanomechanical
resonators.",0808.0743v3
2008-08-07,Extinction of impurity resonances in large-gap regions of inhomogeneous d-wave superconductors,"Impurity resonances observed by scanning tunneling spectroscopy in the
superconducting state have been used to deduce properties of the underlying
pure state. Here we study a longstanding puzzle associated with these
measurements, the apparent extinction of these resonances for Ni and Zn
impurities in large-gap regions of the inhomogeneous BSCCO superconductor. We
calculate the effect of order parameter and hopping suppression near the
impurity site, and find that these two effects are sufficient to explain the
missing resonances in the case of Ni. There are several possible scenarios for
the extinction of the Zn resonances, which we discuss in turn; in addition, we
propose measurements which could distinguish among them.",0808.0966v1
2008-08-22,Nonlinear harmonic generation and devices in doubly-resonant Kerr cavities,"We describea theoretical analysis of the nonlinear dynamics of third-harmonic
generation ($\omega\to3\omega$) via Kerr ($\chithree$) nonlinearities in a
resonant cavity with resonances at both $\omega$ and $3\omega$. Such a doubly
resonant cavity greatly reduces the required power for efficient harmonic
generation, by a factor of $\sim V/Q^2$ where $V$ is the modal volume and $Q$
is the lifetime, and can even exhibit 100% harmonic conversion efficiency at a
critical input power. However, we show that it also exhibits a rich variety of
nonlinear dynamics, such as multistable solutions and long-period limit
cycles.We describe how to compensate for self/cross-phase modulation (which
otherwise shifts the cavity frequencies out of resonance), and how to excite
the different stable solutions (and especially the high-efficiency solutions)
by specially modulated input pulses.",0808.3122v1
2008-08-28,Feshbach resonances in an ultracold $^7$Li and $^{87}$Rb mixture,"We report on the observation of five Feshbach resonances in collisions
between ultracold $^7$Li and $^{87}$Rb atoms in the absolute ground state
mixture where both species are in their $|f,m_f>=|1,1>$ hyperfine states. The
resonances appear as trap losses for the $^7$Li cloud induced by inelastic
heteronuclear three-body collisions. The magnetic field values where they occur
are important quantities for an accurate determination of the interspecies
interaction potentials. Results of coupled channels calculations based on the
observed resonances are presented and refined potential parameters are given. A
very broad Feshbach resonance centered around 649 G should allow for fine
tuning of the interaction strength in future experiments.",0808.3967v1
2008-09-02,Self-detecting gate-tunable nanotube paddle resonators,"We have fabricated suspended metal paddle resonators with carbon nanotubes
functioning as self-detecting torsional springs. We observe gate-tunable
resonances, that either tune to higher or to lower frequencies when increasing
the dc voltage on the back-gate. We attribute the former modes to flexural
vibrations of the paddle resonator, while the latter ones are identified as
torsional vibrations. Compared to top-down silicon fabricated paddle
resonators, nanotube springs have smaller torsional spring constants and
provide a larger frequency tunability.",0809.0372v1
2008-09-11,Nanomechanical-resonator-assisted induced transparency in a Cooper-pair-box system,"We propose a scheme to demonstrate the electromagnetically induced
transparency (EIT) in a system of a superconducting Cooper-pair box coupled to
a nanomechanical resonator. In this scheme, the nanomechanical resonator plays
an important role to contribute additional auxiliary energy levels to the
Cooper-pair box so that the EIT phenomenon could be realized in such a system.
We call it here resonator-assisted induced transparency (RAIT). This RAIT
technique provides a detection scheme in a real experiment to measure physical
properties, such as the vibration frequency and the decay rate, of the coupled
nanomechanical resonator.",0809.1914v1
2008-09-18,New parameterization of the resonant production amplitudes near an inelastic threshold,"New formulae for the resonant scattering and the production amplitudes near
an inelastic threshold are derived. It is shown that the Flatte formula,
frequently used in experimental analyses, is not sufficiently accurate. Its
application to data analysis can lead to a substantial distortion of the
effective mass spectra and of the resonance pole positions.
  A unitary parameterization, satisfying a generalized Watson theorem for the
production amplitudes, is proposed. It can be easily applied to study
production processes, multichannel meson-meson interactions and the resonance
properties, including among others the scalar resonances a0(980) and f_0(980).",0809.3210v1
2008-09-23,Photonic crystal resonator integrated in a microfluidic system,"We report on a novel optofluidic system consisting of a silica-based 1D
photonic crystal, integrated planar waveguides and electrically insulated
fluidic channels. An array of pillars in a microfluidic channel designed for
electrochromatography is used as a resonator for on-column label-free
refractive index detection. The resonator was fabricated in a silicon
oxynitride platform, to support electroosmotic flow, and operated at 1.55
microns. Different aqueous solutions of ethanol with refractive indices ranging
from n = 1.3330 to 1.3616 were pumped into the column/resonator and the
transmission spectra were recorded. Linear shifts of the resonant wavelengths
yielded a maximum sensitivity of 480 nm/RIU and a minimum difference of 0.007
RIU was measured.",0809.3865v1
2008-10-03,Enhancing extraordinary transmission of light through a metallic nano slit with a nano cavity antenna,"The extraordinary transmission of light through a nano slit in a metal film
is enhanced by introducing a nano cavity antenna formed by a nearby metallic
nano-strip over the slit opening. For a fixed wavelength, the width of the
metallic nano-strip should be chosen to make the horizontal
metal-insulator-metal waveguide of finite length resonant as a Fabry-Perot
cavity. When such a cavity antenna is used to enhance the transmission through
a non-resonant nano slit, the slit should be opened at a position with maximal
magnetic field in the horizontal resonant cavity. It is shown that an optimized
cavity antenna can enhance greatly the transmission of light through a
non-resonant nano slit (by about 20 times) or a resonant nano slit (by 124%).
The transmission spectrum of the nano slit can also be tuned by adjusting the
width of the metallic nano-strip. Such a transmission enhancement with a nano
cavity antenna is studied for the first time and the physical mechanism is
explained.",0810.0592v1
2008-10-11,Nonlinear theory of fractional microwave-induced magnetoresistance oscillations in a dc-driven two-dimensional electron system,"Microwave-induced nonlinear magnetoresistance in a dc-driven two-dimensional
electron system is examined using a multi-photon-assisted transport scheme
direct controlled by the current. It is shown that near the 2nd subharmonic of
the cyclotron resonance, the frequency of the resistivity oscillation with the
magnetic-field-normalized current-density is double that at the cyclotron
resonance and its harmonics, in excellent agreement with recent experimental
findings by Hatke {\it et al.} [Phys. Rev. Lett. {\bf 101}, 246811 (2008)]. The
current-induced alternative emergence of resonant two-photon and single-photon
processes is responsible for this frequency doubling. Near the third
subharmonic of the cyclotron resonance, the current-induced consecutive
appearance of resonant 0-/3-photon, two-photon, and single-photon processes may
lead to the frequency tripling of the resistivity oscillation.",0810.2014v3
2008-10-11,Model for Tunneling-mediated Impurity Resonances in Bilayer Cuprate Superconductors,"We have studied tunneling-mediated local density of states (LDOS) of the
surface layer of a bilayer cuprate, where a Zn impurity is located on the
second Cu-O layer. When the tunneling strength between two Cu-O layers is
larger than a critical value, the LDOS on the site just above the Zn impurity
first exhibits a resonant peak near the Fermi surface. The larger the tunneling
strength, the stronger the resonant peak. It is also shown that the height of
the resonant peak oscillates decreasingly with the distance from the site just
above the Zn impurity. The location of the resonant peak in the surface LDOS
depends on doping, energy gap, and the tunneling strength, and has an opposite
bias voltage to that on its nearest neighboring sites. The results could be
tested by the STM experiments and be used to further understand the electronic
properties of high temperature superconductors.",0810.2043v1
2008-10-19,Comparison of imaging with sub-wavelength resolution in the canalization and resonant tunnelling regimes,"We compare the properties of subwavelength imaging in the visible wavelength
range for metal-dielectric multilayers operating in the canalization and the
resonant tunnelling regimes. The analysis is based on the transfer matrix
method and time domain simulations. We show that Point Spread Functions for the
first two resonances in the canalization regime are approximately Gaussian in
shape. Material losses suppress transmission for higher resonances, regularise
the PSF but do not compromise the resolution. In the resonant tunnelling
regime, the MTF may dramatically vary in their phase dependence. Resulting PSF
may have a sub-wavelength thickness as well as may be broad with multiple
maxima and a rapid phase modulation. We show that the width of PSF may be
reduced by further propagation in free space, and we provide arguments to
explain this surprising observation.",0810.3383v1
2008-10-30,Determination of atomic scattering lengths from measurements of molecular binding energies near Feshbach resonances,"We present an analytic model to calculate the atomic scattering length near a
Feshbach resonance from data on the molecular binding energy. Our approach
considers finite-range square-well potentials and can be applied near broad,
narrow, or even overlapping Feshbach resonances. We test our model on Cs$_2$
Feshbach molecules. We measure the binding energy using magnetic-field
modulation spectroscopy in a range where one broad and two narrow Feshbach
resonances overlap. From the data we accurately determine the Cs atomic
scattering length and the positions and widths of two particular resonances.",0810.5503v2
2008-11-02,Narrow absorptive resonances in a four-level atomic system,"We study the effect of a control beam on a Lambda electromagnetically induced
transparency (EIT) system in 87Rb. The control beam couples one ground state to
another excited state forming a four level N-system. Phase coherent beams to
drive the N-system are produced using a double injection scheme. We show that
the control beam can be used to Stark shift or split the EIT resonance.
Finally, we show that the when the control beam is on-resonance one observes a
Doppler-free and sub-natural absorptive resonance with a width of order 100
kHz. Crucially, this narrow absorptive resonance only occurs when atoms with a
range of velocities are present, as is the case in a room temperature vapour.",0811.0193v1
2008-11-05,Dark resonances for ground state transfer of molecular quantum gases,"One possible way to produce ultracold, high-phase-space-density quantum gases
of molecules in the rovibronic ground state is given by molecule association
from quantum-degenerate atomic gases on a Feshbach resonance and subsequent
coherent optical multi-photon transfer into the rovibronic ground state. In
ultracold samples of Cs_2 molecules, we observe two-photon dark resonances that
connect the intermediate rovibrational level |v=73,J=2> with the rovibrational
ground state |v=0,J=0> of the singlet $X^1\Sigma_g^+$ ground state potential.
For precise dark resonance spectroscopy we exploit the fact that it is possible
to efficiently populate the level |v=73,J=2> by two-photon transfer from the
dissociation threshold with the stimulated Raman adiabatic passage (STIRAP)
technique. We find that at least one of the two-photon resonances is
sufficiently strong to allow future implementation of coherent STIRAP transfer
of a molecular quantum gas to the rovibrational ground state |v=0,J=0>.",0811.0695v1
2008-11-14,The yields of light meson resonances in neutrinonuclear interactions at <E_nu> = 10 GeV,"The total yields of the all well-established light mesonic resonances (up to
the $\phi$(1020) meson) are estimated in neutrinonuclear interactions at < E_nu
> = 10 GeV, using the data obtained with SKAT bubble chamber. For some
resonances, the yields in the forward and backward hemispheres in the hadronic
c.m.s. are also extracted. From the comparison of the obtained and available
higher-energy data, an indication is obtained that the resonance yields rise
almost linearly as a function of the mean mass < W > of the neutrinoproduced
hadronic system. The fractions of pions originating from the light resonance
decays are inferred.",0811.2343v1
2008-11-24,Virtual Compton Scattering and Neutral Pion Electroproduction in the Resonance Region up to the Deep Inelastic Region at Backward Angles,"We have made the first measurements of the virtual Compton scattering (VCS)
process via the H$(e,e'p)\gamma$ exclusive reaction in the nucleon resonance
region, at backward angles. Results are presented for the $W$-dependence at
fixed $Q^2=1$ GeV$^2$, and for the $Q^2$-dependence at fixed $W$ near 1.5 GeV.
The VCS data show resonant structures in the first and second resonance
regions. The observed $Q^2$-dependence is smooth. The measured ratio of
H$(e,e'p)\gamma$ to H$(e,e'p)\pi^0$ cross sections emphasizes the different
sensitivity of these two reactions to the various nucleon resonances. Finally,
when compared to Real Compton Scattering (RCS) at high energy and large angles,
our VCS data at the highest $W$ (1.8-1.9 GeV) show a striking $Q^2$-
independence, which may suggest a transition to a perturbative scattering
mechanism at the quark level.",0811.3867v1
2008-12-02,Photonic Feshbach Resonance,"Hermann Feshbach predicted fifty years ago that when two atomic nuclei are
scattered within an open entrance channel-- the state observable at infinity,
they may enter an intermediate closed channel -- the locally bounded state of
the nuclei. If the energy of a bound state of in the closed channel is
fine-tuned to match the relative kinetic energy, then the open channel and the
closed channel ""resonate"", so that the scattering length becomes divergent. We
find that this so-called Feshbach resonance phenomenon not only exists during
the collisions of massive particles, but also emerges during the coherent
transport of massless particles, that is, photons confined in the coupled
resonator arrays \cite{lzhou08}. We implement the open and the closed channels
inside a pair of such arrays, linked by a separated cavity or a tunable qubit.
When a single photon is bounded inside the closed channel by setting the
relevant physical parameters appropriately, the vanishing transmission appears
to display this photonic Feshbach resonance. The general construction can be
implemented through various experimentally feasible solid state systems, such
as the couple defected cavities in photonic crystals. The numerical simulation
based on finite-different time-domain(FDTD) method confirms our conceive about
physical implementation.",0812.0429v1
2008-12-02,Electron- and neutrino-nucleus scattering from the quasielastic to the resonance region,"We present a model for electron- and neutrino-scattering off nucleons and
nuclei focussing on the quasielastic and resonance region. The lepton-nucleon
reaction is described within a relativistic formalism that includes, besides
quasielastic scattering, the excitation of 13 N* and Delta resonances and a
non-resonant single-pion background. Recent electron-scattering data is used
for the state-of-the-art parametrizations of the vector form factors; the axial
couplings are determined via PCAC and, in the case of the Delta resonance, the
axial form factor is refitted using neutrino-scattering data. Scattering off
nuclei is treated within the GiBUU framework that takes into account various
nuclear effects: the local density approximation for the nuclear ground state,
mean-field potentials and in-medium spectral functions. Results for inclusive
scattering off Oxygen are presented and, in the case of electron-induced
reactions, compared to experimental data and other models.",0812.0587v2
2008-12-15,Negative Group Velocity from Quadrupole Resonance of Plasmonic Spheres,"We study the dispersions of plasmonic bands that arise from the coupling of
electric quadrupole resonances in three dimensional photonic crystals (PCs)
consisting of plasmonic spheres. Through analytical derivation, we show that
two branches of quadrupole bands in simple cubic PCs with a small lattice
constant possess negative group velocities. Distinct from double negative media
in which the negative responses originates from the coupling of electric and
magnetic responses (P and M), the negative dispersion induced by quadrupole
resonance is an intrinsic property of quadrupole that does not require coupling
to another degree of freedom. In addition, there is no simple effective medium
description. In plasmonic systems composed of metallic nanoparticle clusters,
the coupled quadrupole resonance may be tuned to lower optical frequencies, and
the coupling strength between this quadrupole resonance and external
electromagnetic (EM) waves are in the same order of the magnetic dipole M.",0812.2717v1
2008-12-18,Microwave frequency modulation in continuous-wave far-infrared ESR utilizing a quasioptical reflection bridge,"We report the development of the frequency-modulation (FM) method for
measuring electron spin resonance (ESR) absorption in the 210-420 GHz frequency
range. We demonstrate that using a high-frequency ESR spectrometer without
resonating microwave components enables us to overcome technical difficulties
associated with the FM method due to nonlinear microwave-elements, without
sacrificing spectrometer performance. FM was achieved by modulating the
reference oscillator of a 13 GHz Phase Locked Dielectric Resonator Oscillator,
and amplifying and frequency-multiplying the resulting millimeter-wave
radiation up to 210, 315 and 420 GHz. ESR spectra were obtained in reflection
mode by a lock-in detection at the fundamental modulation frequency, and also
at the second and third harmonic. Sensitivity of the setup was verified by
conduction electron spin resonance measurement in KC$_{60}$.",0812.3676v1
2008-12-31,A new mechanism of electric dipole spin resonance: hyperfine coupling in quantum dots,"A recently discovered mechanism of electric dipole spin resonance, mediated
by the hyperfine interaction, is investigated experimentally and theoretically.
The effect is studied using a spin-selective transition in a GaAs double
quantum dot. The resonant frequency is sensitive to the instantaneous hyperfine
effective field, revealing a nuclear polarization created by driving the
resonance. A device incorporating a micromagnet exhibits a magnetic field
difference between dots, allowing electrons in either dot to be addressed
selectively. An unexplained additional signal at half the resonant frequency is
presented.",0901.0124v1
2009-01-27,Resonance width oscillation in the bi-ripple ballistic electron waveguide,"Interference of quasi bound states is studied in a ballistic electron ripple
waveguide with two ripple cavities whose distance apart can be varied. This
system is the waveguide analog of Dicke's model for two interacting atoms in a
radiation field. Dicke's model has resonances whose widths change in an
oscillatory manner as the distance between the atoms is varied. Resonances that
form in a bi-ripple waveguide behave in a manner that has some similarity to
Dicke's system, but also important differences. We numerically investigate the
behavior of resonance widths in the waveguide as the distance between the two
ripple cavities changes and we find that the resonance widths oscillate with
variation of distance, but the coupling does not decrease as it does in Dicke's
system. We discuss differences between our waveguide system and other systems
showing the analogous of Dicke effect. We also study S-matrix pole trajectories
and find that they rotate in counterclockwise direction on a circle in the
complex energy plane.",0901.4281v1
2009-02-04,"HD60532, a planetary system in a 3:1 mean motion resonance","In a recent paper it was reported a planetary system around the star HD60532,
composed by two giant planets in a possible 3:1 mean motion resonance, that
should be confirmed within the next decade. Here we show that the analysis of
the global dynamics of the system allows to confirm this resonance. The present
best fit to data already corresponds to this resonant configuration and the
system is stable for at least 5Gry. The 3:1 resonance is so robust that
stability is still possible for a wide variety of orbital parameters around the
best fit solution and also if the inclination of the system orbital plane with
respect to the plane of the sky is as small as 15 deg. Moreover, if the
inclination is taken as a free parameter in the adjustment to the observations,
we find an inclination ~ 20 deg, which corresponds to M_b =3.1 M_Jup and M_c =
7.4 M_Jup for the planetary companions.",0902.0667v1
2009-02-08,Narrow and contrast resonance of increased absorption in Lambda-system observed in Rb cell with buffer gas,"We report observation of a narrow (sub-natural) and high-contrast resonance
of increased absorption (""bright"" resonance) in Rb cell with Ne buffer gas
under previously unexplored experimental conditions for coupling and probe
radiation configuration. The coupling laser stabilized frequency is detuned by
~ 3 GHz from 5S1/2, Fg=3 --> 5P3/2, Fe=2,3,4 transitions, while the probe laser
frequency is scanned across these transitions. We believe the bright resonance
formation, occurring when the probe laser frequency is blue-shifted from the
coupling frequency by a value of the ground state hyperfine splitting, is
caused predominantly by a 2-photon absorption of the probe radiation 5S1/2,
Fg=2 --> 5S1/2, Fg=3 with 5P3/2 as an intermediate state. We also report and
interpret splitting of the bright resonance into 6 well resolved and contrast
components in moderate magnetic fields (B ~ 10 - 250 G).",0902.1319v1
2009-02-10,Fourier Analysis of the Parametric Resonance in Neutrino Oscillations,"Parametric enhancement of the appearance probability of the neutrino
oscillation under the inhomogeneous matter is studied. Fourier expansion of the
matter density profile leads to a simple resonance condition and manifests that
each Fourier mode modifies the energy spectrum of oscillation probability at
around the corresponding energy; below the MSW resonance energy, a large-scale
variation modifies the spectrum in high energies while a small-scale one does
in low energies. In contrast to the simple parametric resonance, the
enhancement of the oscillation probability is itself an slow oscillation as
demonstrated by a numerical analysis with a single Fourier mode of the matter
density. We derive an analytic solution to the evolution equation on the
resonance energy, including the expression of frequency of the slow
oscillation.",0902.1597v1
2009-02-11,Autoionizing Resonances in Time-Dependent Density Functional Theory,"Autoionizing resonances that arise from the interaction of a bound
single-excitation with the continuum can be accurately captured with the
presently used approximations in time-dependent density functional theory
(TDDFT), but those arising from a bound double excitation cannot. In the former
case, we explain how an adiabatic kernel, which has no frequency-dependence,
can yet generate the strongly frequency-dependent resonant structures in the
interacting response function, not present in the Kohn-Sham response function.
In the case of the bound double-excitation, we explain that a strongly
frequency-dependent kernel is needed, and derive one for the vicinity of a
resonance of the latter type, as an {\it a posteriori} correction to the usual
adiabatic approximations in TDDFT. Our approximation becomes exact for an
isolated resonance in the limit of weak interaction, where one discrete state
interacts with one continuum. We derive a ""Fano TDDFT kernel"" that reproduces
the Fano lineshape within the TDDFT formalism, and also a dressed kernel, that
operates on top of an adiabatic approximation. We illustrate our results on a
simple model system.",0902.1961v2
2009-02-13,Proposal for Studying $N^*$ Resonances with $\bar{p}p \to \bar{p}n π^+ $ Reaction,"A theoretical study of $\bar{p}p \to \bar{p}n \pi^+ $ reaction for
anti-proton beam energy from 1 to 4 GeV is made by including contributions from
various known $N^*$ and $\Delta^*$ resonances. It is found that for the beam
energy around 1.5 GeV, the contribution of the Roper resonance $N^*_{(1440)}$
produced by the t-channel $\sigma$ exchange dominates over all other
contributions. Since such reaction can be studied in the forthcoming
$\bar{P}$ANDA experiment at Facility of Antiproton and Ion Research (FAIR), the
reaction will be realistically the cleanest place for studying the properties
of the Roper resonance and the best place for looking for other ""missing"" $N^*$
resonances with large coupling to $N\sigma$.",0902.2295v3
2009-02-15,Probing Nano-Mechanical QED Effects,"We propose and study an ""intrinsic probing"" approach, without introducing any
external detector, to mimic cavity QED effects in a qubit-nanomechanical
resonator system. This metallic nanomechanical resonator can act as an
intrinsic detector when a weak driving current passes through it. The
nanomechanical resonator acts as both the cavity and the detector. A cavity
QED-like effect is demonstrated by the correlation spectrum of the
electromotive force between the two ends of the nanomechanical resonator. Using
the quantum regression theorem and perturbation theory, we analytically
calculate the correlation spectrum. In the weak driving limit, we study the
effect on the vacuum Rabi splitting of both the strength of the driving as well
as the frequency-detuning between the charge qubit and the nanomechanical
resonator. Numerical calculations confirm the validity of our intrinsic probing
approach.",0902.2512v1
2009-02-15,Cooling and squeezing the fluctuations of a nanomechanical beam by indirect quantum feedback control,"We study cooling and squeezing the fluctuations of a nanomechanical beam
using quantum feedback control. In our model, the nanomechanical beam is
coupled to a transmission line resonator via a superconducting quantum
interference device (SQUID). The leakage of the electromagnetic field from the
transmission line resonator is measured using homodyne detection. This measured
signal is then used to design a quantum-feedback-control signal to drive the
electromagnetic field in the transmission line resonator. Although the control
is imposed on the transmission line resonator, this quantum-feedback-control
signal indirectly affects the thermal motion of the nanomechanical beam via the
inductive beam-resonator coupling, making it possible to cool and squeeze the
fluctuations of the beam, allowing it to approach the standard quantum limit.",0902.2526v1
2009-02-19,On Electrical Equivalence of Aperture-Body and Transmission-Cavity Resonance Phenomena in Subwavelength Conducting Aperture Systems from an Equivalent Circuit Point of View,"For a narrow slit structure backed by a conducting strip which is taken as a
representative example of an aperture-body resonance (ABR) problem, the
transmission resonance condition (i.e., condition for maximum power
transmission) and the transmission width (i.e., normalized maximum transmitted
power through the slit) are found to be the same as those for narrow slit
coupling problem in a thick conducting screen, which is designated as a
transmission-cavity resonance (TCR) problem. From a viewpoint of equivalent
circuit representation for the transmission resonance condition and the
funneling mechanism, the ABR and the TCR problems are thought to be essentially
of the same nature.",0902.3328v2
2009-03-02,Realistic quantum manipulation of two-level system fluctuators,"Two-level system fluctuators in superconducting devices have demonstrated
coherent coupling with superconducting qubits. Here, we show that universal
quantum logic gates can be realized in these two-level systems solely by tuning
a superconducting resonator in which they are imbedded. Because of the large
energy separation between the fluctuators, conventional gate schemes in the
cavity QED approach that are widely used for solid-state qubits cannot be
directly applied to the fluctuators. We study a scheme to perform the gate
operations by exploiting the controllability of the superconducting resonator
with realistic parameters. Numerical simulation that takes into account the
decay of the resonator mode shows that the quantum logic gates can be realized
with high fidelity at moderate resonator decay rate. The quantum logic gates
can also be realized between fluctuators inside different Josephson junctions
that are connected by a superconducting loop. Our scheme can be applied to
explore the coupling between two-level system fluctuators and superconducting
resonators as well as the coherent properties of the fluctuators.",0903.0193v1
2009-03-12,Observation of localized ferromagnetic resonance in a continuous ferromagnetic film via magnetic resonance force microscopy,"We present Magnetic Resonance Force Microscopy (MRFM) measurements of
Ferromagnetic Resonance (FMR) in a 50 nm thick permalloy film, tilted with
respect to the direction of the external magnetic field. At small probe-sample
distances the MRFM spectrum breaks up into multiple modes, which we identify as
local ferromagnetic resonances confined by the magnetic field of the MRFM tip.
Micromagnetic simulations support this identification of the modes and show
they are stabilized in the region where the dipolar tip field has a component
anti-parallel to the applied field.",0903.2285v1
2009-03-15,Particle resonance in the Dirac equation in the presence of a delta interaction and a perturbative hyperbolic potential,"In the present article we show that the energy spectrum of the
one-dimensional Dirac equation, in the presence of an attractive vectorial
delta potential, exhibits a resonant behavior when one includes an
asymptotically spatially vanishing weak electric field associated with a
hyperbolic tangent potential. We solve the Dirac equation in terms of Gauss
hyper-geometric functions and show explicitly how the resonant behavior depends
on the strength of the electric field evaluated at the support of the point
interaction. We derive an approximate expression for the value of the
resonances and compare the results calculated for the hyperbolic potential with
those obtained for a linear perturbative potential. Finally, we characterize
the resonances with the help of the phase shift and the Wigner delay time.",0903.2597v2
2009-03-20,Pair-tunneling resonance in the single-electron transport regime,"We predict a new electron pair-tunneling (PT) resonance in non-linear
transport through quantum dots with positive charging energies exceeding the
broadening due to thermal and quantum fluctuations. The PT resonance shows up
in the single-electron transport (SET) regime as a peak in the derivative of
the non-linear conductance when the electrochemical potential of one electrode
matches the average of two subsequent charge addition energies. For a single
level quantum dot (Anderson model) we find the analytic peak shape and the
dependence on temperature, magnetic field and junction asymmetry and compare
with the inelastic cotunneling peak which is of the same order of magnitude. In
experimental transport data the PT resonance may be mistaken for a weak SET
resonance judging only by the voltage dependence of its position. Our results
provide essential clues to avoid such erroneous interpretation of transport
spectroscopy data.",0903.3559v2
2009-03-23,Whispering-gallery mode micro-kylix resonators,"Owing to their ability to confine electromagnetic energy in ultrasmall
dielectric volumes, micro-disk, ring and toroid resonators hold interest for
both specific applications and fundamental investigations. Generally,
contributions from various loss channels within these devices lead to limited
spectral windows (Q-bands) where highest mode Q-factors manifest. Here we
describe a strategy for tuning Q-bands using a new class of micro-resonators,
named micro-kylix resonators, in which engineered stress within an initially
flat disk results in either concave or convex devices. To shift the Q-band by
60nm towards short wavelengths in flat micro-disks a 50% diameter reduction is
required, which causes severe radiative losses suppressing Q's. With a
micro-kylix, we achieve similar tuning and even higher Q's by two orders of
magnitude smaller diameter modification (0.4%). The phenomenon relies on
geometry-induced smart interplay between modified dispersions of material
absorption and radiative loss-related Q-factors. Micro-kylix devices can
provide new functionalities and novel technological solutions for photonics and
micro-resonator physics.",0903.3829v1
2009-03-27,Internal and External Resonances of Dielectric Disks,"Circular microresonators (microdisks) are micron sized dielectric disks
embedded in a material of lower refractive index. They possess modes with
complex eigenvalues (resonances) which are solutions of analytically given
transcendental equations. The behavior of such eigenvalues in the small opening
limit, i.e. when the refractive index of the cavity goes to infinity, is
analysed. This analysis allows one to clearly distinguish between internal
(Feshbach) and external (shape) resonant modes for both TM and TE
polarizations. This is especially important for TE polarization for which
internal and external resonances can be found in the same region of the complex
wavenumber plane. It is also shown that for both polarizations, the internal as
well as external resonances can be classified by well defined azimuthal and
radial modal indices.",0903.4718v1
2009-03-29,Orbital Resonance and Solar Cycles,"We present an analysis of planetary moves, encoded in DE406 ephemerides. We
show resonance cycles between most planets in Solar System, of differing
quality. The most precise resonance - between Earth and Venus, which not only
stabilizes orbits of both planets, locks planet Venus rotation in tidal
locking, but also affects the Sun:
  This resonance group (E+V) also influences Sunspot cycles - the position of
syzygy between Earth and Venus, when the barycenter of the resonance group most
closely approaches the Sun and stops for some time, relative to Jupiter planet,
well matches the Sunspot cycle of 11 years, not only for the last 400 years of
measured Sunspot cycles, but also in 1000 years of historical record of ""severe
winters"". We show, how cycles in angular momentum of Earth and Venus planets
match with the Sunspot cycle and how the main cycle in angular momentum of the
whole Solar system (854-year cycle of Jupiter/Saturn) matches with climatologic
data, assumed to show connection with Solar output power and insolation. We
show the possible connections between E+V events and Solar global p-Mode
frequency changes.
  We futher show angular momentum tables and charts for individual planets, as
encoded in DE405 and DE406 ephemerides. We show, that inner planets orbit on
heliocentric trajectories whereas outer planets orbit on barycentric
trajectories.",0903.5009v1
2009-04-01,Combining electric and magnetic static field for the tuning of the lifetime of zero energy Feshbach resonances: Application to 3He+NH collisions,"We study the variation of the positions of two magnetically tuned Zero energy
Feshbach resonances when a parallel superimposed electric field is applied. We
show that their variation as a function of the electric field follows a simple
analytical law and is then predictable. We find that depending on the initial
state of the diatomic molecule the resonance is either shifted to higher or to
lower values of the magnetic field when the electric field is applied. We
calculate the Close Coupling lifetimes of these resonances and show that they
also follow a simple law as a function of both the magnetic and the electric
field. We demonstrate using this expression that the lifetime of the resonances
can be maximised by choosing an appropriate value of the applied electric and
found a good agreement with the results of our Close Coupling calculations.
These results could be checked in future experiments dedicated to the 3He + NH
collisions",0904.0108v1
2009-04-06,Experimentally Realizable C-NOT Gate in a Flux Qubit/Resonator System,"In this paper we present an experimentally realizable microwave pulse
sequence that effects a Controlled NOT (C-NOT) gate operation on a Josephson
junction-based flux-qubit/resonator system with high fidelity in the end state.
We obtained a C-NOT gate process fidelity of 0.988 (0.980) for a two (three)
qubit/resonator system under ideal conditions, and a fidelity of 0.903 for a
two qubit/resonator system under the best, currently achieved, experimental
conditions. In both cases, we found that ""qubit leakage"" to higher levels of
the resonator causes a majority of the loss of fidelity, and that such leakage
becomes more pronounced as decoherence effects increase.",0904.0933v1
2009-04-08,Quantum interference of particles and resonances,"Though the phenomenon of quantum-mechanical interference has been known for
many years, it still has many open questions. The present review discusses
specifically how the interference of resonances may and does work. We collect
data on the search for rare decay modes of well-known resonances that
demonstrate a wide variety of possible different manifestations of
interference. Some special kinds of resonance interference, not yet
sufficiently studied and understood, are also briefly considered. The
interference may give useful experimental procedures to search for new
resonances with arbitrary quantum numbers, even with exotic ones, and to
investigate their properties.",0904.1376v2
2009-04-30,Confluence of resonant laser excitation and bi-directional quantum dot nuclear spin polarization,"Resonant laser scattering along with photon correlation measurements have
established the atom-like character of quantum dots. Here, we present
measurements which challenge this identification for a wide range of
experimental parameters: the absorption lineshapes that we measure at magnetic
fields exceeding 1 Tesla indicate that the nuclear spins polarize by an amount
that ensures locking of the quantum dot resonances to the incident laser
frequency. In contrast to earlier experiments, this nuclear spin polarization
is bi-directional, allowing the electron+nuclear spin system to track the
changes in laser frequency dynamically on both sides of the quantum dot
resonance. Our measurements reveal that the confluence of the laser excitation
and nuclear spin polarization suppresses the fluctuations in the resonant
absorption signal. A master equation analysis shows narrowing of the nuclear
Overhauser field variance, pointing to potential applications in quantum
information processing.",0904.4767v1
2009-05-18,Shapiro-like Resonance in Ultracold Molecule Production via an Oscillating Magnetic Field,"We study the process of production of ultracold molecules from ultracold
atoms using a sinusoidally oscillating magnetic field modulation. When the
magnetic field is resonant roughly with the molecular binding energy,
Shapiro-like resonances are observed. Their resonance profiles are well fitted
by the Lorentzian functions. The line widths depend on both the amplitude and
the duration of the applied modulations, and are found to be dramatically
broadened by thermal dephasing effect. The resonance centers shift due to both
many-body effect and finite temperature effect. Our theory is consistent with
recent experiment (S. T. Thompson, E. Hodby, and C. E. Wieman, Phys. Rev. Lett.
95, 190404 (2005)). Our model predicts a 1/3 ceiling for the molecular
production yield in uncondensed ultracold atomic clouds for a long coupling
time, while for the condensed atoms the optimal conversion yield could be
beyond the limit.",0905.2890v1
2009-05-18,Microwave whispering gallery resonator for efficient optical up-conversion,"Conversion of microwave radiation into the optical range has been predicted
to reach unity quantum efficiency in whispering gallery resonators made from an
optically nonlinear crystal and supporting microwave and optical modes
simultaneously. In this work we theoretically explore and experimentally
demonstrate a resonator geometry that can provide the required phase matching
for such a conversion at any desired frequency in the sub-THz range. We show
that such a ring-shaped resonator not only allows for the phase matching, but
also maximizes the overlap of the interacting fields. As a result,
unity-efficient conversion is expected in a resonator with feasible parameters.",0905.2961v2
2009-05-19,Generation of nonground-state condensates and adiabatic paradox,"The problem of resonant generation of nonground-state condensates is
addressed aiming at resolving the seeming paradox that arises when one resorts
to the adiabatic representation. In this picture, the eigenvalues and
eigenfunctions of a time-dependent Gross-Pitaevskii Hamiltonian are also
functions of time. Since the level energies vary in time, no definite
transition frequency can be introduced. Hence no external modulation with a
fixed frequency can be made resonant. Thus, the resonant generation of
adiabatic coherent modes is impossible. However, this paradox occurs only in
the frame of the adiabatic picture. It is shown that no paradox exists in the
properly formulated diabatic representation. The resonant generation of
diabatic coherent modes is a well defined phenomenon. As an example, the
equations are derived, describing the generation of diabatic coherent modes by
the combined resonant modulation of the trapping potential and atomic
scattering length.",0905.3068v1
2009-05-22,Renormalization group equations in resonance chiral theory,"The use of the equations of motion and meson field redefinitions allows the
development of a simplified resonance chiral theory lagrangian: terms including
resonance fields and a large number of derivatives can be reduced into
corresponding O(p2) resonance operators, containing the lowest possible number
of derivatives. This is shown by means of the explicit computation of the pion
vector form-factor up to next-to-leading order in 1/Nc. The study of the
renormalization group equations for the corresponding couplings demonstrates
the existence of an infrared fixed point in the resonance theory. The
possibility of developing a perturbative 1/Nc expansion in the slow running
region around the fixed point is shown here.",0905.3676v2
2009-05-26,Resonance saturation at next-to-leading order,"A proper estimation of the chiral low-energy constants of Chiral Perturbation
Theory is a very important task. To this end resonance chiral Lagrangians have
been used fruitfully. We have studied the determination of chiral couplings at
next-to-leading (NLO) order in the 1/N(C) expansion, keeping full control of
the renormalization scale dependence. We find that, by imposing short-distance
constraints coming from QCD, resonance saturation at NLO in 1/N(C) is
satisfied. In other words, the chiral couplings can be written in terms of the
resonance masses and couplings and do not depend explicitly on the coefficients
of the chiral operators in the Goldstone boson sector of Resonance Chiral
Theory.",0905.4299v1
2009-06-18,Nearby resonances beyond the Breit-Wigner approximation,"We consider a description of propagators for particle resonances which takes
into account the quantum mechanical interference due to the width of two or
more nearby states that have common decay channels, by incorporating the
effects arising from the imaginary parts of the one-loop self-energies.
Depending on the couplings to the common decay channels, the interference
effect, not taken into account in the usual Breit-Wigner approximation, can
significantly modify the cross section or make the more long-lived resonance
narrower. We give few examples of New Physics models for which the effect is
sizable, namely a generic two and multiple Higgs model and neutral vector
resonances in Higgsless models. Based on these results we suggest the
implementation of a proper treatment of nearby resonances into Monte Carlo
generators.",0906.3417v2
2009-06-19,Resonant spin transport through a superconducting double barrier structure,"We study resonant transport through a superconducting double barrier
structure. At each barrier, due to the proximity effect, an incident electron
can either reflect as an electron or a hole (Andreev reflection). Similarly,
transport across the barrier can occur via direct tunneling as electrons as
well as via the crossed Andreev channel, where a hole is transmitted. In the
subgap regime, for a symmetric double barrier system (with low transparency for
each barrier), we find a new T=1/4 resonance (T is the transmission probability
for electrons incident on the double barrier structure) due to interference
between electron and hole wave-functions between the two barriers, in contrast
to a normal double barrier system which has the standard transmission resonance
at T=1. We also point out as an application that the resonant value of T=1/4
can produce pure spin current through the superconducting double barrier
structure.",0906.3679v3
2009-06-25,A new N* resonance as a hadronic molecular state,"We report our recent work on a hadronic molecule state of the KbarKN system
with I=1/2 and J^P=1/2^+. We assume that the Lambda(1405) resonance and the
scalar mesons, f_{0}(980), a_{0}(980), are reproduced as quasi-bound states of
KbarN and KbarK, respectively. Performing non-relativistic three-body
calculations with a variational method for this system, we find a quasibound
state of the KbarKN system around 1910 MeV below the three-body breakup
threshold. This state corresponds to a new baryon resonance of N* with
J^P=1/2^+. We find also that this resonance has the cluster structure of the
two-body bound states keeping their properties as in the isolated two-particle
systems. We also briefly discuss another hadronic molecular state composed by
two Kbar and one N, which corresponds to a Xi^* resonance.",0906.4653v1
2009-06-25,Two Dynamical Classes of Centaurs,"The Centaurs are a transient population of small bodies in the outer solar
system whose orbits are strongly chaotic. These objects typically suffer
significant changes of orbital parameters on timescales of a few thousand
years, and their orbital evolution exhibits two types of behaviors described
qualitatively as random-walk and resonance-sticking. We have analyzed the
chaotic behavior of the known Centaurs. Our analysis has revealed that the two
types of chaotic evolution are quantitatively distinguishable: (1) the random
walk-type behavior is well described by so-called generalized diffusion in
which the rms deviation of the semimajor axis grows with time t as ~t^H, with
Hurst exponent H in the range 0.22--0.95, however (2) orbital evolution
dominated by intermittent resonance sticking, with sudden jumps from one mean
motion resonance to another, has poorly defined H. We further find that these
two types of behavior are correlated with Centaur dynamical lifetime: most
Centaurs whose dynamical lifetime is less than ~22 Myr exhibit generalized
diffusion, whereas most Centaurs of longer dynamical lifetimes exhibit
intermittent resonance sticking. We also find that Centaurs in the diffusing
class are likely to evolve into Jupiter-family comets during their dynamical
lifetimes, while those in the resonance-hopping class do not.",0906.4795v1
2009-06-29,Noise of Kondo dot with ac gate: Floquet-Green's function and Noncrossing Approximation Approach,"The transport properties of an ac-driving quantum dot in the Kondo regime are
studied by the Floquet-Green's function method with slave-boson infinite-$U$
noncrossing approximation. Our results show that the Kondo peak of the local
density of states is robust against weak ac gate modulation. Significant
suppression of the Kondo peak can be observed when the ac gate field becomes
strong. The photon-assisted noise of Kondo resonance as a function of dc
voltage does not show singularities which are expected for noninteracting
resonant quantum dot. These findings suggest that one may make use of the
photon-assisted noise measurement to tell apart whether the resonant transport
is via noninteracting resonance or strongly-correlated Kondo resonance.",0906.5266v1
2009-07-02,"Reexamination of Astrophysical Resonance Reaction Rate Equations for An Isolated, Narrow Resonance","The well-known astrophysical resonant reaction rate equations for an isolated
narrow resonance have been reexamined. The validity of those `look reliable'
assumptions used in deriving the analytic reaction rate equations has been
checked, and the reality is they only hold for certain circumstances.
Importantly an integration-range issue hidden in the classical integration
equations has been revealed and it hints us not to use those analytic equations
in the future. This work may influence all those work in which the classical
narrow resonant equations were used for calculating the stellar reaction rates,
especially at low stellar temperatures, and may affect the results of stellar
evolution and nucleosynthesis network calculations considerably.",0907.0271v2
2009-07-21,Performance of Monolayer Graphene Nanomechanical Resonators with Electrical Readout,"The enormous stiffness and low density of graphene make it an ideal material
for nanoelectromechanical (NEMS) applications. We demonstrate fabrication and
electrical readout of monolayer graphene resonators, and test their response to
changes in mass and temperature. The devices show resonances in the MHz range.
The strong dependence of the resonant frequency on applied gate voltage can be
fit to a membrane model, which yields the mass density and built-in strain.
Upon removal and addition of mass, we observe changes in both the density and
the strain, indicating that adsorbates impart tension to the graphene. Upon
cooling, the frequency increases; the shift rate can be used to measure the
unusual negative thermal expansion coefficient of graphene. The quality factor
increases with decreasing temperature, reaching ~10,000 at 5 K. By establishing
many of the basic attributes of monolayer graphene resonators, these studies
lay the groundwork for applications, including high-sensitivity mass detectors.",0907.3721v2
2009-07-23,Effective Stochastic Resonance under Heterogeneous Amplitude of Noise,"Effective stochastic resonance (SR) is numerically and analytically studied
using a model with coupled two particles exposed to heterogeneous, i.e.,
particles dependent, amplitude of noise. Compared to previous SR models of
single particle and to those of coupled two particles exposed to equivalent
amplitude of noise, the present model exhibits a more intensive resonance of,
at least, one particle exposed to the non-larger amplitude of noise with the
assistance of another particle. In a certain range of conditions, this
effective resonance of one particle overwhelms the poor resonance of the other
particle, meaning that heterogeneous amplitude of noise leads the system, not
only locally but also in the average of the whole, to the effective SR.",0907.3968v4
2009-08-04,Regge-plus-resonance predictions for kaon photoproduction from the neutron,"We present predictions for n(gamma,K+)Sigma- differential cross sections and
photon-beam asymmetries and compare them to recent LEPS data. We adapt a
Regge-plus-resonance (RPR) model developed to describe photoinduced and
electroinduced kaon production off protons. The non-resonant contributions to
the amplitude are modelled in terms of K+(494) and K*+(892) Regge-trajectory
exchange. This amplitude is supplemented with a selection of s-channel
resonance diagrams. The three Regge-model parameters of the n(gamma,K+)Sigma-
amplitude are derived from the ones fitted to proton data through SU(2) isospin
considerations. A fair description of the n(gamma,K+)Sigma- data is realized,
which demonstrates the Regge model's robustness and predictive power.
Conversion of the resonances' couplings from the proton to the neutron is more
challenging, as it requires knowledge of the photocoupling helicity amplitudes.
We illustrate how the uncertainties of the helicity amplitudes propagate and
heavily restrain the predictive power of the RPR and isobar models for kaon
production off neutron targets.",0908.0446v2
2009-08-05,Experimental Test of a Two-dimensional Approximation for Dielectric Microcavities,"Open dielectric resonators of different shapes are widely used for the
manufacture of microlasers. A precise determination of their resonance
frequencies and widths is crucial for their design. Most microlasers have a
flat cylindrical geometry, and a two-dimensional approximation, the so-called
method of the effective index of refraction, is commonly employed for numerical
calculations. Our aim has been an experimental test of the precision and
applicability of a model based on this approximation. We performed very
thorough and accurate measurements of the resonance frequencies and widths of
two passive circular dielectric microwave resonators and found significant
deviations from the model predictions. From this we conclude that the model
generally fails in the quantitative description of three-dimensional dielectric
resonators.",0908.0598v1
2009-08-06,Resonance as a probe of the electron superconducting gap in BaFe1.9Ni0.1As2,"The discovery of high-transition temperature (high-Tc) superconductivity near
antiferromagnetism in iron arsenides raised the possibility of an
unconventional superconducting mechansim1-8. The observation of clear Fermi
surfaces and nodeless superconducting gaps by angle resolved photoemission9-12
suggests that electron pairing in these materials may be mediated by
quasiparticle excitations between sign reversed hole and electron Fermi
pockets5-8. Although the presence of a 'resonance' in the spin excitation
spectrum found by inelastic neutron scattering13-17 is consistent with this
picture18-20, there has been no direct evidence connecting the resonance to the
superconducting gap energy. Here we show that for the optimally electron doped
BaFe1.9Ni0.1As2 (Tc =20 K, Fig. 1c) iron arsenide superconductor, application
of a magnetic field that suppresses the superconductivity and superconducting
gap energy also reduces the intensity and energy of the resonance. These
results suggest that the energy of the resonance is proportional to the
electron pairing energy, and thus indicate that spin fluctuations are
intimately related to the mechanism of superconductivity in iron arsenides.",0908.0954v1
2009-08-14,Broad Feshbach resonance in the 6Li-40K mixture,"We study the widths of interspecies Feshbach resonances in a mixture of the
fermionic quantum gases 6Li and 40K. We develop a model to calculate the width
and position of all available Feshbach resonances for a system. Using the model
we select the optimal resonance to study the 6Li/40K mixture. Experimentally,
we obtain the asymmetric Fano lineshape of the interspecies elastic cross
section by measuring the distillation rate of 6Li atoms from a potassium-rich
6Li/40K mixture as a function of magnetic field. This provides us with the
first experimental determination of the width of a resonance in this mixture,
Delta B=1.5(5) G. Our results offer good perspectives for the observation of
universal crossover physics using this mass-imbalanced fermionic mixture.",0908.2071v2
2009-09-01,Resonant Excitation of Disk Oscillations in Two-Armed-Deformed Disks and Application to High-Frequency QPOs,"In previous papers we showed that in a one-armed deformed disks, p-mode and
g-mode oscillations are resonantly excited by horizontal resonance, and applied
it to high frequency QPOs observed in low mass X-ray binaries. In that model,
the observed time variation of kHz QPOs is regarded as a result of a
time-dependent precession of the deformation. In this paper we consider another
possible cause of time variation of kHz QPOs. That is, we demonstrate that in a
two-armed deformed disks, p-mode and g-mode oscillations are excited by {\it
vertical resonance}, not by horizontal resonance(horizontal resonance dampens
them). Furthermore, we show that in the case of vertical resonance, the
frequencies of disk oscillations excited can vary with time if vertical disk
structure changes with time. A brief application of these results to the time
variation of observed kHz QPOs is made.",0909.0142v1
2009-09-30,Effect of magnetic field on the spin resonance in FeTe(0.5)Se(0.5) as seen via inelastic neutron scattering,"Inelastic neutron scattering and susceptibility measurements have been
performed on the optimally-doped Fe-based superconductor FeTe(0.5)Se(0.5),
which has a critical temperature, Tc of 14 K. The magnetic scattering at the
stripe antiferromagnetic wave-vector Q = (0.5,0.5) exhibits a ""resonance"" at ~
6 meV, where the scattering intensity increases abruptly when cooled below Tc.
In a 7-T magnetic field parallel to the a-b plane, Tc is slightly reduced to ~
12 K, based on susceptibility measurements. The resonance in the neutron
scattering measurements is also affected by the field. The resonance intensity
under field cooling starts to rise at a lower temperature ~ 12 K, and the low
temperature intensity is also reduced from the zero-field value. Our results
provide clear evidence for the intimate relationship between superconductivity
and the resonance measured in magnetic excitations of Fe-based superconductors.",0910.0027v2
2009-10-15,Disorder effect of resonant spin Hall effect in a tilted magnetic field,"We study the disorder effect of resonant spin Hall effect in a two-dimension
electron system with Rashba coupling in the presence of a tilted magnetic
field. The competition between the Rashba coupling and the Zeeman coupling
leads to the energy crossing of the Landau levels, which gives rise to the
resonant spin Hall effect. Utilizing the Streda's formula within the
self-consistent Born approximation, we find that the impurity scattering
broadens the energy levels, and the resonant spin Hall conductance exhibits a
double peak around the resonant point, which is recovered in an applied titled
magnetic field.",0910.2869v1
2009-10-17,Microcavity exciton-polariton mediated Raman scattering: Experiments and theory,"We studied the intensity of resonant Raman scattering due to optical phonons
in a planar II-VI-type semiconductor microcavity in the regime of strong
coupling between light and matter. Two different sets of independent
experiments were performed at near outgoing resonance with the middle polariton
(MP)branch of the cavity. In the first, the Stokes-shifted photons were kept at
exact resonance with the MP, varying the photonic or excitonic character of the
polariton. In the second, only the incoming light wavelength was varied, and
the resonant profile of the inelastic scattered intensity was studied when the
system was tuned out of the resonant condition. Taking some matrix elements as
free parameters, both independent experiments are quantitatively described by a
model which incorporates lifetime effects in both excitons and photons, and the
coupling of the cavity photons to the electron-hole continuum. The model is
solved using a Green's function approach which treats the exciton-photon
coupling nonperturbatively.",0910.3313v1
2009-10-29,Multipurpose High Frequency Electron Spin Resonance Spectrometer for Condensed Matter Research,"We describe a quasi-optical multifrequency ESR spectrometer operating in the
75-225 GHz range and optimized at 210 GHz for general use in condensed matter
physics, chemistry and biology. The quasi-optical bridge detects the change of
mm wave polarization at the ESR. A controllable reference arm maintains a mm
wave bias at the detector. The attained sensitivity of 2x10^10 spin/G/(Hz)1/2,
measured on a dilute Mn:MgO sample in a non-resonant probe head at 222.4 GHz
and 300 K, is comparable to commercial high sensitive X band spectrometers. The
spectrometer has a Fabry-Perot resonator based probe head to measure aqueous
solutions, and a probe head to measure magnetic field angular dependence of
single crystals. The spectrometer is robust and easy to use and may be operated
by undergraduate students. Its performance is demonstrated by examples from
various fields of condensed matter physics.",0910.5504v1
2009-10-30,Observation of a J^PC = 1-+ exotic resonance in diffractive dissociation of 190 GeV/c pi- into pi- pi- pi+,"The COMPASS experiment at the CERN SPS has studied the diffractive
dissociation of negative pions into the pi- pi- pi+ final state using a 190
GeV/c pion beam hitting a lead target. A partial wave analysis has been
performed on a sample of 420000 events taken at values of the squared
4-momentum transfer t' between 0.1 and 1 GeV^2/c^2. The well-known resonances
a1(1260), a2(1320), and pi2(1670) are clearly observed. In addition, the data
show a significant natural parity exchange production of a resonance with
spin-exotic quantum numbers J^PC = 1-+ at 1.66 GeV/c^2 decaying to rho pi. The
resonant nature of this wave is evident from the mass-dependent phase
differences to the J^PC = 2-+ and 1++ waves. From a mass-dependent fit a
resonance mass of 1660 +- 10+0-64 MeV/c^2 and a width of 269+-21+42-64 MeV/c^2
is deduced.",0910.5842v3
2010-01-04,Above threshold s-wave resonances illustrated by the 1/2$^+$ states in $^9$Be and $^9$B,"We solve the persistent problem of the structure of the lowest $1/2^+$
resonance in $^9$Be which is important to bridge the A=8 gap in nucleosynthesis
in stars. We show that the state is a genuine three-body resonance even though
it decays entirely into neutron-$^8$Be relative s-waves. The necessary barrier
is created by ""dynamical"" evolution of the wave function as the short-distance
$\alpha$-$^5$He structure is changed into the large-distance n-$^8$Be
structure. This decay mechanism leads to a width about two times smaller than
table values. The previous interpretations as a virtual state or a two-body
resonance are incorrect. The isobaric analog 1/2$^+$ state in $^9$B is found to
have energy and width in the vicinity of 2.0 MeV and 1.5 MeV, respectively. We
also predict another 1/2$^+$ resonance in $^9$B with similar energy and width.",1001.0459v1
2010-01-09,Wide spin resonance with an rf-bunched proton beam,"We recently used an rf solenoid to study the widths of rf spin resonances
with both unbunched and bunched beams of 2.1 GeV_c polarized protons stored in
the COSY synchrotron. A map, with unbunched beam at different fixed rf-solenoid
frequencies, showed a very shallow possible depolarization dip at the
resonance. Next we made frequency sweeps of 400Hz, centered at similar
frequencies, which greatly enhanced the dip. But, with a bunched proton beam,
both the fixed-frequency and frequency-sweep techniques produced similar maps,
and both bunched maps showed full beam depolarization over a wide region.
Moreover, both were more than twice as wide as the unbunched dip. This widening
of the proton resonance due to bunching is exactly opposite to the recently
observed narrowing of deuteron resonances due to bunching.",1001.1456v1
2010-01-18,Tuning mechanical modes and influence of charge screening in nanowire resonators,"We probe electro-mechanical properties of InAs nanowire (diameter ~ 100 nm)
resonators where the suspended nanowire (NW) is also the active channel of a
field effect transistor (FET). We observe and explain the non-monotonic
dispersion of the resonant frequency with DC gate voltage (VgDC). The effect of
electronic screening on the properties of the resonator can be seen in the
amplitude. We observe the mixing of mechanical modes with VgDC. We also
experimentally probe and quantitatively explain the hysteretic non-linear
properties, as a function of VgDC, of the resonator using the Duffing equation.",1001.2882v1
2010-01-19,Resonances as a possible observable of hot and dense nuclear matter,"One of the most fundamental questions in the field of relativistic heavy ion
physics is how to reach and explore densities which are needed to cross the
chiral and/or the deconfinement phase transition. In this analysis we
investigate the information we can gather by analyzing baryonic and mesonic
resonances on the hot and dense phase in such nuclear reactions. The decay
products of these resonances carry information on the resonances properties at
the space time point of their decay. We especially investigate the percentage
of reconstructable resonances as a function of density for heavy ion collisions
in the energy range between $E_{lab}$ = 30 AGeV and $\sqrt{s}$ = 200 AGeV, the
energy domain between the future FAIR facility and the present RHIC collider.",1001.3260v1
2010-01-19,Spin determination of single-produced resonances at hadron colliders,"We study the production of a single resonance at the LHC and its decay into a
pair of Z bosons. We demonstrate how full reconstruction of the final states
allows us to determine the spin and parity of the resonance and restricts its
coupling to vector gauge bosons. Full angular analysis is illustrated with the
simulation of the production and decay chain including all spin correlations
and the most general couplings of spin-zero, -one, and -two resonances to
Standard Model matter and gauge fields. We note implications for analysis of a
resonance decaying to other final states.",1001.3396v2
2010-01-22,Separation of Transitions with Two Quantum Jumps from Cascades,"We consider the general scenario of an excited level |i> of a quantum system
that can decay via two channels: (i) via a single-quantum jump to an
intermediate, resonant level |bar m>, followed by a second single-quantum jump
to a final level |f>, and (ii) via a two-quantum transition to a final level
|f>. Cascade processes |i> -> |bar m> -> | f> and two-quantum transitions |i>
-> |m> -> |f> compete (in the latter case, |m> can be both a nonresonant as
well as a resonant level). General expressions are derived within second-order
time-dependent perturbation theory, and the cascade contribution is identified.
When the one-quantum decay rates of the virtual states are included into the
complex resonance energies that enter the propagator denominator, it is found
that the second-order decay rate contains the one-quantum decay rate of the
initial state as a lower-order term. For atomic transitions, this implies that
the differential-in-energy two-photon transition rate with complex resonance
energies in the propagator denominators can be used to good accuracy even in
the vicinity of resonance poles.",1001.3955v1
2010-01-23,Overlapping Resonances in the Resistance of Superposition States to Decoherence,"Overlapping resonances are shown to provide new insights into the extent of
decoherence experienced by a system superposition state in the regime of strong
system- environment coupling. As an example of this general approach, a generic
system comprising spin-half particles interacting with a thermalized oscillator
environment is considered. We find that (a) amongst the collection of
parametrized Hamiltonians, the larger the overlapping resonances contribution,
the greater the maximum possible purity, and (b) for a fixed Hamiltonian, the
larger the overlapping resonances contribution, the larger the range of
possible values of the purity as one varies the phases in the system
superposition states. Systems displaying decoherence free subspaces show that
largest overlapping resonances contribution.",1001.4134v1
2010-01-25,Probing thermal expansion of graphene and modal dispersion at low-temperature using graphene NEMS resonators,"We use suspended graphene electromechanical resonators to study the variation
of resonant frequency as a function of temperature. Measuring the change in
frequency resulting from a change in tension, from 300 K to 30 K, allows us to
extract information about the thermal expansion of monolayer graphene as a
function of temperature, which is critical for strain engineering applications.
We find that thermal expansion of graphene is negative for all temperatures
between 300K and 30K. We also study the dispersion, the variation of resonant
frequency with DC gate voltage, of the electromechanical modes and find
considerable tunability of resonant frequency, desirable for applications like
mass sensing and RF signal processing at room temperature. With lowering of
temperature, we find that the positively dispersing electromechanical modes
evolve to negatively dispersing ones. We quantitatively explain this crossover
and discuss optimal electromechanical properties that are desirable for
temperature compensated sensors.",1001.4377v1
2010-01-26,Tunneling and transmission resonances of a Dirac particle by a double barrier,"We calculate the tunneling process of a Dirac particle across two square
barriers separated a distance $d$, as well as the scattering by a double cusp
barrier where the centers of the cusps are separated a distance larger than
their screening lengths. Using the scattering matrix formalism, we obtain the
transmission and reflection amplitudes for the scattering processes of both
configurations. We show that, the presence of transmission resonances modifies
the Lorentizian shape of the energy resonances and induces the appearance of
additional maxima in the transmission coefficient in the range of energies
where transmission resonances occur. We calculate the Wigner time-delay and
show how their maxima depend on the position of the transmission resonance.",1001.4712v1
2010-01-30,Systematic design study of all-optical delay line based on Brillouin scattering enhanced cascade coupled ring resonators,"We present a technique to improve the slow-light performance of a
side-coupled spaced sequence of resonators (SCISSOR) combined with a stimulated
Brillouin scattering (SBS) gain medium in optical fiber. We evaluate device
performance of SCISSOR-only and SCISSOR + SBS systems for different numbers of
cascaded resonators from 1 to 70 using two different data fidelity metrics
including eye-opening and mutual information. A practical system design is
demonstrated by analyzing its performance in terms of fractional delay, power
transmission, and data fidelity. We observe that the results from the two
metrics are in good agreement. Based on system optimization under practical
resource and fidelity constraints, the SCISSOR consisting of 70 cascaded
resonators provides a fractional delay of 8 with 22 dB attenuation at a signal
bit rate of 10 Gbps. The combined optimal SCISSOR (with 70 resonators) + SBS
system provides a improved fractional delay up to 17 with unit power
transmission under the same constraints.",1002.0084v1
2010-02-19,Confinement-Induced Resonances in Low-Dimensional Quantum Systems,"We report on the observation of confinement-induced resonances in strongly
interacting quantum-gas systems with tunable interactions for one- and
two-dimensional geometry. Atom-atom scattering is substantially modified when
the s-wave scattering length approaches the length scale associated with the
tight transversal confinement, leading to characteristic loss and heating
signatures. Upon introducing an anisotropy for the transversal confinement we
observe a splitting of the confinement-induced resonance. With increasing
anisotropy additional resonances appear. In the limit of a two-dimensional
system we find that one resonance persists.",1002.3795v2
2010-03-13,Instability of Bose-Einstein condensates in tilted lattices with time-periodical modulation,"We study the dynamical stability of Bose-Einstein condensates in an optical
lattice with a time-periodic modulation potential and a constant acceleration
force simultaneously. We derive the explicit expressions of quasienergies and
obtain the stability diagrams in the parameter space of the interaction
strength and the modulation amplitude. The ratio of the acceleration force to
the modulation frequency characterizes two cases: integer and non-integer
resonances. For integer resonances, the critical interaction strength
$g_{\mathrm{c}}$ shows an alternate behavior where the completely unstable
regions correspond to the negative effective tunneling strength. Among
non-integer resonances, we observe that $g_{\mathrm{c}}$ peaks are centered
around half-integer resonances for which the completely unstable regions
disappear, accompanied with a whole displacement of $g_{\mathrm{c}}$. Compared
with integer and half-integer resonances, the crossovers between them show no
explicit dependence of $g_{\mathrm{c}}$ on the modulation amplitude.",1003.2673v1
2010-03-20,On confinement resonances in A@C60 photoionization: easy to observe?,"Possible reasons that confinement resonances are not observed in a recent
photoionization experiment on the endohedral fullerene Ce@C82+ are explored.
The effect of the polarization of the fullerene shell in response to the
ionization of the endohedrally encaged atom A@Cn, termed the ""shielding""
effect, has been investigated and found to be relatively small; no more than a
20% effect near threshold, and much less at higher energies. It is argued that
most likely, the absence of confinement resonances in Ce@C82+ is due primarily
to the finite thickness of the carbon cage; the off-the-center position and
thermal vibration of the encaged atom, discussed elsewhere, further weaken the
resonances rendering them beyond the sensitivity of the experiment to detect,
in this case. For other situations/endohedrals, the confinement resonances
should well be observable, and Ne@C60 is suggested as an excellent candidate.",1003.3906v1
2010-03-24,Radiative decay into gamma-baryon of dynamically generated resonances from the vector-baryon interaction,"We study the radiative decay into $\gamma$ and a baryon of the SU(3) octet
and decuplet of nine and ten resonances that are dynamically generated from the
interaction of vector mesons with baryons of the octet and the decuplet
respectively. We obtain quite different partial decay widths for the various
resonances, and for different charge states of the same resonance, suggesting
that the experimental investigation of these radiative decays should bring much
information on the nature of these resonances. For the case of baryons of the
octet we determine the helicity amplitudes and compare them with experimental
data when available.",1003.4664v1
2010-04-05,Sub-Fourier characteristics of a $δ$-kicked rotor resonance,"We experimentally investigate the sub-Fourier behavior of a $\delta$-kicked
rotor resonance by performing a measurement of the fidelity or overlap of a
Bose-Einstein condensate (BEC) exposed to a periodically pulsed standing wave.
The temporal width of the fidelity resonance peak centered at the Talbot time
and zero initial momentum exhibits an inverse cube pulse number ($1/N^{3}$)
dependent scaling compared to a $1/N^{2}$ dependence for the mean energy width
at the same resonance. A theoretical analysis shows that for an accelerating
potential the width of the resonance in acceleration space depends on
$1/N^{3}$, a property which we also verify experimentally. Such a sub-Fourier
effect could be useful for high precision gravity measurements.",1004.0683v2
2010-04-13,Electroweak non-resonant NLO corrections to e+ e- -> W+ W- b bbar in the t tbar resonance region,"We analyse subleading electroweak effects in the top anti-top resonance
production region in e+ e- collisions which arise due to the decay of the top
and anti-top quarks into the W+ W- b bbar final state. These are NLO
corrections adopting the non-relativistic power counting v ~ alpha_s ~
sqrt(alpha_EW). In contrast to the QCD corrections which have been calculated
(almost) up to NNNLO, the parametrically larger NLO electroweak contributions
have not been completely known so far, but are mandatory for the required
accuracy at a future linear collider. The missing parts of these NLO
contributions arise from matching coefficients of non-resonant production-decay
operators in unstable-particle effective theory which correspond to off-shell
top production and decay and other non-resonant irreducible background
processes to t tbar production. We consider the total cross section of the e+
e- -> W+ W- b bbar process and additionally implement cuts on the invariant
masses of the W+ b and W- bbar pairs.",1004.2188v1
2010-04-23,Room-temperature Tunable Fano Resonance by Chemical Doping in Few-layer Graphene Synthesized by Chemical Vapor Deposition,"A Fano-like phonon resonance is observed in few-layer (~3) graphene at room
temperature using infrared Fourier transform spectroscopy. This Fano resonance
is the manifestation of a strong electron-phonon interaction between the
discrete in-plane lattice vibrational mode and continuum electronic excitations
in graphene. By employing ammonia chemical doping, we have obtained different
Fano line shapes ranging from anti-resonance in hole-doped graphene to
phonon-dominated in n-type graphene. The Fano resonance shows the strongest
interference feature when the Fermi level is located near the Dirac point. The
charged phonon exhibits much-enhanced oscillator strength and experiences a
continuous red shift in frequency as electron density increases. It is
suggested that the phonon couples to different electronic transitions as Fermi
level is tuned by chemical doping.",1004.4042v1
2010-06-04,Treatment the Effects of Studio Wall Resonance and Coincidence Phenomena for Recording Noisy Speech Via FPGA Digital Filter,"This work introduces an economic solution for the problems of sound
insulation of recording studios. Sound insulation at wall resonance frequency
is weak. Instead of acoustical treatment, a digital filter is used to eliminate
the effects of wall resonance and coincidence phenomena on recording of speech.
Sound insulation of studio is measured to calculate the wall resonance
frequency and the coincidence frequency. Pole /zero placement technique is used
to calculate the IIR filter coefficients. The digital filter is designed,
simulated and implemented. The proposed system is used to treat these problems
and it is shown to be effective in recording the noisy speech. In this work
digital signal processing is used instead of the acoustic treatment to
eliminate the effect of noise at the studio wall resonance. This technique is
cheap and effective in canceling the noise at the desired frequencies. Field
Programmable Gate Array (FPGA) is used for hardware implementation of the
proposed filter structure which provides fast and cheap solution for processing
real time audio signals. The implementation is carried out using Spartan chip
from Xinlinx achieving higher performance than commercially available software
solutions.",1006.0831v1
2010-06-09,Observation of superluminal geometrical resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions,"We study Fiske steps in small Bi2Sr2CaCu2O8+x mesa structures, containing
only few stacked intrinsic Josephson junctions. Careful alignment of magnetic
field prevents penetration of Abrikosov vortices and facilitates observation of
a large variety of high quality geometrical resonances, including superluminal
with velocities larger than the slowest velocity of electromagnetic waves. A
small number of junctions limits the number of resonant modes and allows
accurate identification of modes and velocities. It is shown that superluminal
geometrical resonances can be excited by subluminal fluxon motion and that
flux-flow itself becomes superluminal at high magnetic fields. We argue that
observation of high-quality superluminal geometrical resonances is crucial for
realization of the coherent flux-flow oscillator in the THz frequency range.",1006.1751v1
2010-06-14,Electrostatic actuation of silicon optomechanical resonators,"Optomechanical systems offer one of the most sensitive methods for detecting
mechanical motion using shifts in the optical resonance frequency of the
optomechanical resonator . Presently, these systems are used for measuring
mechanical thermal noise displacement or mechanical motion actuated by optical
forces. Electrostatic capacitive actuation and detection have been shown
previously for silicon micro electro mechanical resonators for application in
filters and oscillators. Here, we demonstrate monolithic integration of
electrostatic capacitive actuation with optical sensing using silicon
optomechanical disk resonators and waveguides. The electrically excited
mechanical motion is observed as an optical intensity modulation when the input
electrical signal is at a frequency of 235MHz corresponding to the radial
vibrational mode of the silicon microdisk.",1006.2783v2
2010-06-22,Fermion Resonances on a Thick Brane with a Piecewise Warp Factor,"In this paper, we mainly investigate the problems of resonances of massive KK
fermions on a single scalar constructed thick brane with a piecewise warp
factor matching smoothly. The distance between two boundaries and the other
parameters are determined by one free parameter through three junction
conditions. For the generalized Yukawa coupling $\eta\bar{\Psi}\phi^{k}\Psi$
with odd $k=1,3,5,...$, the mass eigenvalue $m$, width $\Gamma$, lifetime
$\tau$, and maximal probability $P_{max}$ of fermion resonances are obtained.
Our numerical calculations show that the brane without internal structure also
favors the appearance of resonant states for both left- and right-handed
fermions. The scalar-fermion coupling and the thickness of the brane influence
the resonant behaviors of the massive KK fermions.",1006.4240v3
2010-06-18,Inelastic neutron scattering study on the resonance mode in an optimally doped superconductor LaFeAsO$_{0.92}$F$_{0.08}$,"An optimally doped iron-based superconductor LaFeAsO$_{0.92}$F$_{0.08}$ with
$T_c = 29$ K has been studied by inelastic powder neutron scattering. The
magnetic excitation at $Q=1.15$ \AA$^{-1}$ is enhanced below $T_c$, leading to
a peak at $E_{res}\sim13$ meV as the resonance mode, in addition to the
formation of a gap at low energy below the crossover energy $\Delta_{c}\sim10
meV$. The peak energy at $Q=1.15$ \AA$^{-1}$ corresponds to $5.2 k_B T_c$ in
good agreement with the other values of resonance mode observed in the various
iron-based superconductors, even in the high-$T_c$ cuprates. Although the
phonon density of states has a peak at the same energy as the resonance mode in
the present superconductor, the $Q$-dependence is consistent with the resonance
being of predominately magnetic origin.",1006.4640v1
2010-07-07,Resonant Subband Landau Level Coupling in Symmetric Quantum Well,"Subband structure and depolarization shifts in an ultra-high mobility
GaAs/Al_{0.24}Ga_{0.76}As quantum well are studied using magneto-infrared
spectroscopy via resonant subband Landau level coupling. Resonant couplings
between the 1st and up to the 4th subbands are identified by well-separated
anti-level-crossing split resonance, while the hy-lying subbands were
identified by the cyclotron resonance linewidth broadening in the literature.
In addition, a forbidden intersubband transition (1st to 3rd) has been
observed. With the precise determination of the subband structure, we find that
the depolarization shift can be well described by the semiclassical slab plasma
model, and the possible origins for the forbidden transition are discussed.",1007.1197v1
2010-07-22,Couplings in coupled channels versus wave functions in the case of resonances: application to the two $Λ(1405)$ states,"In this paper we develop a formalism to evaluate wave functions in momentum
and coordinate space for the resonant states dynamically generated in a unitary
coupled channel approach. The on shell approach for the scattering matrix,
commonly used, is also obtained in Quantum Mechanics with a separable
potential, which allows one to write wave functions in a trivial way. We
develop useful relationships among the couplings of the dynamically generated
resonances to the different channels and the wave functions at the origin. The
formalism provides an intuitive picture of the resonances in the coupled
channel approach, as bound states of one bound channel, which decays into open
ones. It also provides an insight and practical rules for evaluating couplings
of the resonances to external sources and how to deal with final state
interaction in production processes. As an application of the formalism we
evaluate the wave functions of the two $\Lambda(1405)$ states in the $\pi
\Sigma$, $\bar{K} N$ and other coupled channels.",1007.3923v2
2010-07-31,Strongly quadrature-dependent noise in superconducting micro-resonators measured at the vacuum-noise limit,"We measure frequency- and dissipation-quadrature noise in superconducting
lithographed microwave resonators with sensitivity near the vacuum noise level
using a Josephson parametric amplifier. At an excitation power of 100~nW, these
resonators show significant frequency noise caused by two-level systems. No
excess dissipation-quadrature noise (above the vacuum noise) is observed to our
measurement sensitivity. These measurements demonstrate that the excess
dissipation-quadrature noise is negligible compared to vacuum fluctuations, at
typical readout powers used in micro-resonator applications. Our results have
important implications for resonant readout of various devices such as
detectors, qubits and nano-mechanical oscillators.",1008.0046v1
2010-08-02,Metallic nanoparticle on micro ring resonator for bio optical detection and sensing,"We have investigated the unique effects of metallic nanoparticle on the ring
resonator, especially multiple Au nanoparticles on the micro ring resonator
with the 4-port configuration on chip. For the Au nanoparticle, because it has
smaller real refractive index than air and large absorption refractive index,
we found that there is a blue shift for the ring resonance wavelength, instead
of red shift normally observed for dielectric nanoparticles. The drop port
intensity is strongly dependent on both number and size of nanoparticles, while
relatively independent on position of nanoparticles. The correlation between
the penetration depth of Au and the resonance mode evanescent tail is also
discussed to reveal the unique properties of Au nanoparticle to be used for
detection, sensing and nano medicine.",1008.0284v1
2010-08-06,Testing Lorentz Invariance by Comparing Light Propagation in Vacuum and Matter,"We present a Michelson-Morley type experiment for testing the isotropy of the
speed of light in vacuum and matter. The experiment compares the resonance
frequency of a monolithic optical sapphire resonator with the resonance
frequency of an orthogonal evacuated optical cavity made of fused silica while
the whole setup is rotated on an air bearing turntable once every 45 s.
Preliminary results yield an upper limit for the anisotropy of the speed of
light in matter (sapphire) of \Delta c/c < 4x10^(-15), limited by the frequency
stability of the sapphire resonator operated at room temperature. Work to
increase the measurement sensitivity by more than one order of magnitude by
cooling down the sapphire resonator to liquid helium temperatures (LHe) is
currently under way.",1008.1205v2
2010-08-12,Narrow structure in the coherent population trapping resonances in rubidium and Rayleigh scattering,"The measurement of the coherent-population-trapping (CPT) resonances in
uncoated Rb vacuum cells has shown that the shape of the resonances is
different in different cells. In some cells the resonance has a complex shape -
a narrow Lorentzian structure, which is not power broadened, superimposed on
the power broadened CPT resonance. The results of the performed investigations
on the fluorescence angular distribution are in agreement with the assumption
that the narrow structure is a result of atom interaction with Rayleigh
scattering light. The results are interesting for indication of the vacuum
cleanness of the cells and building of magnetooptical sensors.",1008.2033v2
2010-09-01,Stark-tuned Förster resonance and dipole blockade for two to five cold Rydberg atoms: Monte Carlo simulations for various spatial configurations,"Results of numerical Monte Carlo simulations for the Stark-tuned F\""orster
resonance and dipole blockade between two to five cold rubidium Rydberg atoms
in various spatial configurations are presented. The effects of the atoms'
spatial uncertainties on the resonance amplitude and spectra are investigated.
The feasibility of observing coherent Rabi-like population oscillations at a
F\""orster resonance between two cold Rydberg atoms is analyzed. Spectra and the
fidelity of the Rydberg dipole blockade are calculated for various experimental
conditions, including nonzero detuning from the F\""orster resonance and finite
laser linewidth. The results are discussed in the context of
quantum-information processing with Rydberg atoms.",1009.0095v2
2010-09-15,Mixing of fermion fields of opposite parities and baryon resonances,"We consider a loop mixing of two fermion fields of opposite parities whereas
the parity is conserved in a Lagrangian. Such kind of mixing is specific for
fermions and has no analogy in boson case. Possible applications of this effect
may be related with physics of baryon resonances. The obtained matrix
propagator defines a pair of unitary partial amplitudes which describe the
production of resonances of spin $J$ and different parity ${1/2}^{\pm}$ or
${3/2}^{\pm}$. The use of our amplitudes for joint description of $\pi N$
partial waves $P_{13}$ and $D_{13}$ shows that the discussed effect is clearly
seen in these partial waves as the specific form of interference between
resonance and background. Another interesting application of this effect may be
a pair of partial waves $S_{11}$ and $P_{11}$ where the picture is more
complicated due to presence of several resonance states.",1009.2845v2
2010-09-23,Resonant charging of Xe clusters in Helium nanodroplets under intense laser fields,"We theoretically investigate the impact of multiple plasmon resonances on the
charging of Xe clusters embedded in He nanodroplets under intense pump-probe
laser excitation. Our molecular dynamics simulations on Xe309He10000$ and
comparison to results for free Xe309$ give clear evidence for selective
resonance heating in the He shell and the Xe cluster, but no corresponding
double hump feature in the final Xe charge spectra is found. Though the
presence of the He shell substantially increases the maximum charge states, the
pump-probe dynamics of the Xe spectra from embedded system is similar to that
of the free species. In strong contrast to that, the predicted electron spectra
do show well-separated and pronounced features from highly efficient plasmon
assisted electron acceleration for both resonances in the embedded clusters. A
detailed analysis of the underlying ionization and recombination dynamics is
presented and explains the apparent disaccord between the resonance features in
the ion and electron spectra.",1009.4546v2
2010-09-29,Photoproduction of K Sigma(1385) from the nucleon,"The reactions of $K \Sigma(1385)$ photoproduction, i.e., $\gamma p \to K^+
\Sigma^0(1385)$ and $\gamma n \to K^+ \Sigma^-(1385)$, are investigated in the
resonance energy region for studying the role of the nucleon and $\Delta$
resonances of masses around 2 GeV. The Lagrangians for describing the decays of
these resonances into the $K \Sigma(1385)$ channel are constructed and the
decay amplitudes are obtained, which allows us to determine the coupling
constants using the predictions of quark models or the data listed by the
Particle Data Group. The resulting cross sections are compared to the data from
the Thomas Jefferson National Accelerator Facility and the SPring-8, which
indicates nontrivial contributions from the two-star-rated resonances in the
Particle Data Group as well as from some missing resonances predicted by a
quark model.",1009.5789v1
2010-10-07,Resonant-state expansion of the Green's function of open quantum systems,"Our series of recent work on the transmission coefficient of open quantum
systems in one dimension will be reviewed. The transmission coefficient is
equivalent to the conductance of a quantum dot connected to leads of quantum
wires. We will show that the transmission coefficient is given by a sum over
all discrete eigenstates without a background integral. An apparent
""background"" is in fact not a background but generated by tails of various
resonance peaks. By using the expression, we will show that the Fano asymmetry
of a resonance peak is caused by the interference between various discrete
eigenstates. In particular, an unstable resonance can strongly skew the peak of
a nearby resonance.",1010.1342v1
2010-10-20,Diffusion-induced dephasing in nanomechanical resonators,"We study resonant response of an underdamped nanomechanical resonator with
fluctuating frequency. The fluctuations are due to diffusion of molecules or
microparticles along the resonator. They lead to broadening and change of shape
of the oscillator spectrum. The spectrum is found for the diffusion confined to
a small part of the resonator and where it occurs along the whole nanobeam. The
analysis is based on extending to the continuous limit, and appropriately
modifying, the method of interfering partial spectra. We establish the
conditions of applicability of the fluctuation-dissipation relations between
the susceptibility and the power spectrum. We also find where the effect of
frequency fluctuations can be described by a convolution of the spectra without
these fluctuations and with them as the only source of the spectral broadening.",1010.4330v1
2010-10-28,Disappearance of zinc impurity resonance in large gap region on Bi$_{\mathrm{2}}$Sr$_{\mathrm{2}}$CaCu$_{\mathrm{2}}$O$_{\mathrm{8+}δ}$ probed by scanning tunneling spectroscopy,"Using Scanning tunneling spectroscopy (STS), we report the correlation
between spatial gap inhomogeneity and the zinc (Zn) impurity resonance in
single crystals of
Bi$_{\mathrm{2}}$Sr$_{\mathrm{2}}$Ca(Cu$_{\mathrm{1-}x}$Zn$_{x}$)$_{\mathrm{2}}$O$_{\mathrm{8+}\delta}$
with different carrier (hole) concentrations ($p$) at a fixed Zn concentration
($x$ $\sim$ 0.5 % per Cu atom). In all the samples, the impurity resonance lies
only in the region where the gap value is less than $\sim$ 60 meV. Also the
number of Zn resonance sites drastically decreases with decreasing $p$, in
spite of the fixed $x$. These experimental results lead us to a conclusion that
the Zn impurity resonance does not appear in the large gap region although the
Zn impurity evidently resides in this region.",1010.5839v2
2010-11-05,Dynamical generation of pseudoscalar resonances,"We study the interactions between the f_0(980) and a_0(980) scalar resonances
and the lightest pseudoscalar mesons. We first obtain the elementary
interaction amplitudes, or interacting kernels, without including any ad hoc
free parameter. This is achieved by using previous results on the nature of the
lightest scalar resonances as dynamically generated from the rescattering of
S-wave two-meson pairs. Afterwards, the interaction kernels are unitarized and
the final S-wave amplitudes result. We find that these interactions are very
rich and generate a large amount of pseudoscalar resonances that could be
associated with the K(1460), \pi(1300), \pi(1800), \eta(1475) and X(1835). We
also consider the exotic channels with isospin 3/2 and 1, having the latter
positive G-parity. The former could be also resonant in agreement with a
previous prediction.",1011.1434v1
2010-11-20,Quantum Transport Theory for Photonic Networks,"In this paper, we develop a quantum transport theory to describe photonic
transport in photonic networks. The photonic networks concerned in the paper
consist of all-optical circuits incorporating photonic bandgap waveguides and
driven resonators. The photonic transport flowing through waveguides are
entirely determined from the exact master equation of the driven resonators.
The master equation of the driven resonators is obtained by explicitly
eliminating all the waveguide degrees of freedom while the back-reactions
between resonators and waveguides are fully taken into account. The relations
between the driven photonic dynamics and photocurrents are obtained. The
non-Markovian memory structure and quantum coherence and decoherence effects in
photonic transport are also fully included. This quantum transport theory
unifies two fundamental nonequilibrium approaches, the Keldysh's nonequilibrium
Green function technique and the Feynman-Vernon influence functional approach,
together to make the investigation of the transient quantum photonic transport
become more powerful. As an illustration, the theory is applied to the
transport phenomena of a driven nanocavity coupled to two waveguides in
photonic crystals. The controllability of photonic transport through the driven
resonator is demonstrated.",1011.4570v2
2010-11-21,Strong gate coupling of high-Q nanomechanical resonators,"The detection of mechanical vibrations near the quantum limit is a formidable
challenge since the displacement becomes vanishingly small when the number of
phonon quanta tends towards zero. An interesting setup for on-chip
nanomechanical resonators is that of coupling them to electrical microwave
cavities for detection and manipulation. Here we show how to achieve a large
cavity coupling energy of up to (2 \pi) 1 MHz/nm for metallic beam resonators
at tens of MHz. We used focused ion beam (FIB) cutting to produce uniform slits
down to 10 nm, separating patterned resonators from their gate electrodes, in
suspended aluminum films. We measured the thermomechanical vibrations down to a
temperature of 25 mK, and we obtained a low number of about twenty phonons at
the equilibrium bath temperature. The mechanical properties of Al were
excellent after FIB cutting and we recorded a quality factor of Q ~ 3 x 10^5
for a 67 MHz resonator at a temperature of 25 mK. Between 0.2K and 2K we find
that the dissipation is linearly proportional to the temperature.",1011.4645v1
2010-12-11,Shape resonance at a Lifshitz transition for high temperature superconductivity in multiband superconductors,"We discuss the shape resonance in the superconducting gaps of a two band
superconductor by tuning the chemical potential at a Lifshitz transition for
Femi surface neck collapsing and for spot appearing. The high temperature
superconducting scenario for complex matter shows the coexistence of a first
BCS condensate made of Cooper pairs in the first band and a second boson-like
condensate made of bosons like bipolarons, in the second band where the
chemical potential is tuned near a Lifshitz transition. The interband coupling
controls the shape resonance in the pair exchange between the two condensates.
We discuss the particular BCS-Bose crossover that occurs at the shape resonance
tuning the Lifshitz parameter (the energy difference between the chemical
potential and the Lifshitz topological transition) like tuning the external
magnetic field for the Feshbach resonances in ultracold gases. This
superconducting phase provides a particular case of topological
superconductivity with multiple condensates of different winding numbers",1012.2436v1
2010-12-20,Phonon Resonators : The Building Blocks of Nanocomposite Adjusting the Electron - Phonon Interaction,"The nanocrystallite have the finite number of the oscillation modes. Their
number increases proportionally to a cube of the characteristic size. Thus the
oscillation spectrum of nanocrystal becomes discrete, and the separate modes of
oscillations does not interact with each other, that considerably strengthens
all phonon modulated processes in a crystal. Covering of such a nanocrystallite
with the shielding surface of a material with the higher nuclear weight will
allow to create the phonon resonators whose oscillation modes will represent
the standing waves and, will be amplified by the resonant manner. The
composites made of phonon resonators will allow to produce a perspective
functional material for the electronics with adjustable structure and
properties. Some new mechanism of HTS based on phonon resonators is proposed.",1012.4286v1
2011-01-04,High-sensing properties of magnetic plasmon resonances in double- and triple-rod structures,"We numerically investigated the magnetic plasmon resonances in double-rod and
triple-rod structures (DRSs and TRSs, respectively) for sensing applications.
According to the equivalent circuit model, one magnetic plasmon mode was
induced in the DRS. Due to the hybridization effect, two magnetic plasmon modes
were obtained in the TRS. Compared with the electric plasmon resonance in a
single-rod structure (SRS), the electromagnetic fields near the DRS and TRS
were much more localized in the dielectric surrounding the structures at the
resonance wavelengths. This caused the magnetic plasmon resonance wavelengths
to become very sensitive to refractive index changes in the environment medium.
As a result, a large figure of merit that is much larger than the electric
plasmon modes of SRS could be obtained in the magnetic plasmon modes of DRS and
TRS. These magnetic plasmon mode properties enable the use of DRSs and TRSs as
sensing elements with remarkable performance.",1101.0735v1
2011-01-08,Effects of Resonant Cavity on Macroscopic Quantum Tunneling of Fluxon in Long Josephson Junctions,"We investigate the effects of high-Q_c resonant cavity on macroscopic quantum
tunneling (MQT) of fluxon both from a metastable state to continuum and from
one degenerate ground-state of a double-well potential to the other. By using a
set of two coupled perturbed sine-Gordon equations, we describe the tunneling
processes in linear long Josephson junctions (LJJs) and find that MQT in the
resonant cavity increases due to potential renomalization, induced by the
interaction between the fluxon and cavity.Enhancement of the MQT rate in the
weak-coupling regime is estimated by using the experimantally accessible range
of the model parameters. The tunneling rate from the metastable state is found
to increase weakly with increasing junction-cavity interaction strength.
However, the energy splitting between the two degenerate ground-states of the
double-well potential increases significantly with increasing both the
interaction strength and frequency of the resonant cavity mode. Finally, we
discuss how the resonant cavity may be used to tune the property of Josephson
vortex quantum bits.",1101.1617v1
2011-01-24,Search for High Mass Resonances Decaying to Muon Pairs in $\sqrt{s}=1.96$ TeV $p\bar{p}$ Collisions,"We present a search for a new narrow, spin-1, high mass resonance decaying to
$\mu^+\mu^- + X $, using a matrix element based likelihood and a simultaneous
measurement of the resonance mass and production rate. In data with 4.6
fb$^{-1}$ of integrated luminosity collected by the CDF detector in $p\bar{p}$
collisions at $\sqrt{s}=1960$ GeV, the most likely signal cross section is
consistent with zero at 16\% confidence level. We therefore do not observe
evidence for a high mass resonance, and place limits on models predicting
spin-1 resonances, including $M > 1071$ GeV/$c^2$ at 95\% confidence level for
a $Z'$ boson with the same couplings to fermions as the $Z$ boson.",1101.4578v1
2011-01-28,"On scattering cross sections and durations near an isolated compound-resonance, distorted by the non-resonant background, in the center-of-mass and laboratory systems","During last 20 years there was revealed and published the phenomenon of the
appearing of the time advance instead of the time delay at the region of a
compound-nucleus resonance, distorted by the non-resonant background (in the
center-of-mass (C-) system). This phenomenon is usually accompanied by a
minimum in the cross section near the same energy. Here we analyze the cross
section and the time delay of the nucleon-nucleus scattering in the laboratory
(L-) system. In the L-system the delay-advance phenomenon does not appear. We
use and concretize the non-standard analytical transformations of the cross
section from the C-system to the L-system, obtained in our previous papers.
They are illustrated by the calculations of energy dependences of cross
sections in the L-system for several cases of nucleon elastic scattering by
nuclei 12C, 16O, 28Si, 52Cr, 56Fe and 64Ni at the range of distorted resonances
in comparison with the experimental data.",1101.5541v1
2011-02-01,The Bright Side of Coulomb Blockade,"We explore the photonic (bright) side of dynamical Coulomb blockade (DCB) by
measuring the radiation emitted by a dc voltage-biased Josephson junction
embedded in a microwave resonator. In this regime Cooper pair tunneling is
inelastic and associated to the transfer of an energy 2eV into the resonator
modes. We have measured simultaneously the Cooper pair current and the photon
emission rate at the resonance frequency of the resonator. Our results show two
regimes, in which each tunneling Cooper pair emits either one or two photons
into the resonator. The spectral properties of the emitted radiation are
accounted for by an extension to DCB theory.",1102.0131v1
2011-02-02,Feshbach spectroscopy and analysis of the interaction potentials of ultracold sodium,"We have studied magnetic Feshbach resonances in an ultracold sample of Na
prepared in the absolute hyperfine ground state. We report on the observation
of three s-, eight d-, and three g-wave Feshbach resonances, including a more
precise determination of two known s-wave resonances, and one s-wave resonance
at a magnetic field exceeding 200mT. Using a coupled-channels calculation we
have improved the sodium ground-state potentials by taking into account these
new experimental data, and derived values for the scattering lengths. In
addition, a description of the molecular states leading to the Feshbach
resonances in terms of the asymptotic-bound-state model is presented.",1102.0572v1
2011-02-11,Monolithic whispering-gallery mode resonators with vertically coupled integrated bus waveguides,"We report on the realization and optical characterization of a
CMOS-compatible silicon-based microresonator/waveguide coupled system, fully
integrated on a silicon chip. The device uses a vertical coupling scheme
between the resonator and a buried strip waveguide. We demonstrate that its
high optical quality follows from the accurate planarization of the waveguide
topography. More importantly, we demonstrate a wafer-scale mass fabrication of
freestanding planar resonators suspended in air and coupled to the integrated
bus waveguides. A nanometer control of the coupling distances allows for a
precise and selective excitation of different mode families of the resonator.
This opens the door for the realization of stable all-integrated complex
resonator systems for optomechanical and metrological applications, with the
potential to substitute the nowadays intensive use of complicated fiber-taper
coupling schemes.",1102.2370v1
2011-02-20,Resonant scattering in galaxy clusters for anisotropic gas motions on various spatial scales,"The determination of characteristic amplitudes and anisotropy of hot gas
motions in galaxy clusters from observations of the brightest resonance lines
is discussed. Gas motions affect (i) the spectral line shape through the
Doppler effect and (ii) the radial surface brightness profiles in lines during
resonant scattering. Radiative transfer calculations have been performed by the
Monte Carlo method in the FeXXV resonance line at 6.7 eV for the Perseus
cluster (Abell426). It was shown that (a) radial motions reduce the scattering
efficiency much more dramatically than purely tangential motions; (b)
large-scale gas motions weakly affect the scattering efficiency. The
uncertainty in measuring the characteristics of gas motions using resonant
scattering has been estimated for existing and future observations of clusters.",1102.4098v2
2011-03-04,Pygmy resonance and torus mode within Vlasov dynamics,"The pygmy dipole resonance in neutron-rich nuclei is studied within the
framework of the Vlasov equation which is solved numerically. The interaction
used in the Thomas-Fermi ground state and in the Vlasov equation is derived
from an energy functional which correctly describes the equation of state of
nuclear matter and neutron matter. It is found that the pygmy resonance appears
in the electric dipole response of all nuclei with strong neutron excess, the
energies and transition probabilities being in reasonable agreement with
experimental results. Since the Vlasov equation does not account for any shell
effects, this indicates that the existence of the pygmy resonance is a generic
phenomenon and does not rely on the specific shell structure. Besides the
electric dipole response, the isoscalar toroidal response is calculated. The
transition densities and velocity fields are discussed. A comparison of the
peak positions and velocity fields suggests that the pygmy resonance can be
identified with one of the low-lying modes excited by the isoscalar toroidal
operator.",1103.0861v3
2011-03-09,Nonlinear damping in mechanical resonators based on graphene and carbon nanotubes,"Carbon nanotubes and graphene allow fabricating outstanding nanomechanical
resonators. They hold promise for various scientific and technological
applications, including sensing of mass, force, and charge, as well as the
study of quantum phenomena at the mesoscopic scale. Here, we have discovered
that the dynamics of nanotube and graphene resonators is in fact highly exotic.
We propose an unprecedented scenario where mechanical dissipation is entirely
determined by nonlinear damping. As a striking consequence, the quality factor
Q strongly depends on the amplitude of the motion. This scenario is radically
different from that of other resonators, whose dissipation is dominated by a
linear damping term. We believe that the difference stems from the reduced
dimensionality of carbon nanotubes and graphene. Besides, we exploit the
nonlinear nature of the damping to improve the figure of merit of
nanotube/graphene resonators.",1103.1788v1
2011-03-25,Lasing and transport in a quantum dot-resonator circuit,"We study a double quantum dot system coherently coupled to an electromagnetic
resonator. A current through the dot system can create a population inversion
in the dot levels and, within a narrow resonance window, a lasing state in the
resonator. The lasing state correlates with the transport properties. On one
hand, this allows probing the lasing state via a current measurement. On the
other hand, the resulting narrow current peak allows resolving small
differences in the dot properties, e.g., a small difference in the Zeeman
splittings of the two dots. For realistic situations relaxation processes have
pronounced consequences. Remarkably, they may even enhance the resolution
between different spin states by releasing a trapped population in the
off-resonant spin channel.",1103.5051v2
2011-03-28,The neutrino spectral split in core-collapse supernovae: a magnetic resonance phenomenon,"A variety of neutrino flavour conversion phenomena occur in core-collapse
supernova, due to the large neutrino density close to the neutrinosphere, and
the importance of the neutrino-neutrino interaction. Three different regimes
have been identified so far, usually called the synchronization, the bipolar
oscillations and the spectral split. Using the formalism of polarization
vectors, within two-flavours, we focus on the spectral split phenomenon and we
show for the first time that the physical mechanism underlying the neutrino
spectral split is a magnetic resonance phenomenon. In particular, we show that
the precession frequencies fulfill the magnetic resonance conditions. Our
numerical calculations show that the neutrino energies and the location at
which the resonance takes place in the supernova coincide well with the
neutrino energies at which a spectral swap occurs. The corresponding
adiabaticity parameters present spikes at the resonance location.",1103.5302v2
2011-04-02,Vector meson-Baryon dynamics and generation of resonances,"The purpose of this work is to study vector meson-octet baryon interactions
with the aim to find dynamical generation of resonances in such systems. For
this, we consider s-, t-, u-channel diagrams along with a contact interaction
originating from the hidden local symmetry Lagrangian. We find the contribution
from all these sources, except the s-channel, to be important. The amplitudes
obtained by solving coupled channel Bethe Salpeter equations for systems with
total strangeness zero, show generation of one isospin 3/2, spin 1/2 resonance
and three isospin 1/2 resonances: two with spin 3/2 and one with spin 1/2. We
identify these resonances with $\Delta (1900) S_{31}$, $N^* (2080) D_{13}$,
$N^* (1700) D_{13}$, and $N^*(2090) S_{11}$, respectively.",1104.0307v1
2011-04-08,Pulsed Adiabatic Photoassociation via Scattering Resonances,"We develop the theory for the Adiabatic Raman Photoassociation (ARPA) of
ultracold atoms to form ultracold molecules in the presence of scattering
resonances. Based on a computational method in which we replace the continuum
with a discrete set of ""effective modes"", we show that the existence of
resonances greatly aids in the formation of deeply bound molecular states. We
illustrate our general theory by computationally studying the formation of
$^{85}$Rb$_2$ molecules from pairs of colliding ultracold $^{85}$Rb atoms. The
single-event transfer yield is shown to have a near-unity value for wide
resonances, while the ensemble-averaged transfer yield is shown to be higher
for narrow resonances. The ARPA yields are compared with that of (the
experimentally measured) ""Feshbach molecule"" magneto-association. Our findings
suggest that an experimental investigation of ARPA at sub-$\mu$K temperatures
is warranted.",1104.1480v2
2011-04-11,Surface Plasmon Driven Electric and Magnetic Resonators for Metamaterials,"Using interplay between surface plasmons and metamaterials, we propose a new
technique for novel metamaterial designs. We show that surface plasmons
existing on thin metal surfaces can be used to ""drive"" non-resonant structures
in their vicinity to provide new types of electric and magnetic resonators.
These resonators strictly adhere to surface plasmon dispersion of the host
metal film. The operating frequency of the resultant metamaterials can be
scaled to extremely high frequencies, otherwise not possible with conventional
split-ring-resonator-based designs. Our approach opens new possibilities for
theory and experiment in the interface of plasmonics and metamaterials to
harvest many potential applications of both fields combined.",1104.1956v1
2011-04-14,Odd Parity Light Baryon Resonances,"We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian
within a coupled channel unitary approach in order to calculate the T-matrix
for meson-baryon scattering in s-wave. The building blocks of the scheme are
the pion and nucleon octets, the rho nonet and the Delta decuplet. We identify
poles in this unitary T-matrix and interpret them as resonances. We study here
the non exotic sectors with strangeness S=0,-1,-2,-3 and spin J=1/2, 3/2 and
5/2. Many of the poles generated can be associated with known N, Delta, Sigma,
Lambda and Xi resonances with negative parity. We show that most of the
low-lying three and four star odd parity baryon resonances with spin 1/2 and
3/2 can be related to multiplets of the spin-flavor symmetry group SU(6). This
study allows us to predict the spin-parity of the Xi(1620), Xi(1690), Xi(1950),
Xi(2250), Omega(2250) and Omega(2380) resonances, which have not been
determined experimentally yet.",1104.2737v2
2011-05-03,Tuning Fano-type resonances in coupled quantum point contacts by applying asymmetric voltages,"We study the ballistic magnetotransport in a double quantum point contact
(QPC) device consisting of a quasi-one-dimensional quantum wire with an
embedded island-like impurity - etched nano-hole as in a recently published
experiment [J. C. Chen, Y. Lin, K.-T. Lin, T. Ueda and S. Komiyama, Appl. Phys.
Lett. 94, 012105 (2009)]. We reproduce the zero field quantized conductance,
the interference phenomenon induced by the coupled QPCs, as well as the
Ramsauer-like resonances observed in the experiments. At finite magnetic fields
Fano-type resonances arises in the conductance due to the formation of
localized states at the impurity periphery and to an inter-edge state resonant
coupling effect. It is predicted that the Fano-type resonances can be
controlled by an asymmetric confinement of the QPCs.",1105.0687v1
2011-05-16,A Godunov-type method for the shallow water equations with discontinuous topography in the resonant regime,"We investigate the Riemann problem for the shallow water equations with
variable and (possibly) discontinuous topography and provide a complete
description of the properties of its solutions: existence; uniqueness in the
non-resonant regime; multiple solutions in the resonant regime. This analysis
leads us to a numerical algorithm that provides one with a Riemann solver.
Next, we introduce a Godunov-type scheme based on this Riemann solver, which is
well-balanced and of quasi-conservative form. Finally, we present numerical
experiments which demonstrate the convergence of the proposed scheme even in
the resonance regime, except in the limiting situation when Riemann data
precisely belong to the resonance hypersurface.",1105.3074v2
2011-05-23,Heavy quark spin structure in Z_b resonances,"We discuss the heavy quark spin structure of the recently observed `twin'
resonances $Z_b(10610)$ and $Z_b(10650)$ assuming that these are mostly of a
`molecular' type, i.e. that their internal dynamics is dominated by the
coupling to meson pairs $B^* \bar B - B {\bar B}^*$ and $B^* {\bar B}^*$. We
find that the state of the $b \bar b$ pair within the $Z_b(10610)$ and
$Z_b(10650)$ resonances is a mixture of a spin-triplet and a spin-singlet of
equal amplitude and with the phase orthogonal between the two resonances. Such
a structure gives rise to specific relations between observable amplitudes that
are in agreement with the data obtained recently by Belle. We also briefly
discuss possible properties of the isotopically singlet counterparts of the
newly found resonances, and also of their $C$ ($G$) parity opposites that
likely exist in the same mass range near the open $B$ flavor threshold.",1105.4473v2
2011-05-25,In-plane magnetic field effect on the neutron spin resonance in optimally doped FeSe$_{0.4}$Te$_{0.6}$ and BaFe$_{1.9}$Ni$_{0.1}$As$_{2}$ superconductors,"We use inelastic neutron scattering to study the effect of an in-plane
magnetic field on the magnetic resonance in optimally doped superconductors
FeSe$_{0.4}$Te$_{0.6}$ ($T_c=14$ K) and BaFe$_{1.9}$Ni$_{0.1}$As$_{2}$
($T_c=20$ K). While the magnetic field up to 14.5 Tesla does not change the
energy of the resonance, it particially suppresses $T_c$ and the corresponding
superconductivity-induced intensity gain of the mode. However, we find no
direct evidence for the field-induced spin-1 Zeeman splitting of the resonance.
Therefore, it is still unclear if the resonance is the long-sought
singlet-triplet excitation directly coupled to the superconducting electron
Cooper pairs.",1105.4923v2
2011-06-17,Resonant scattering in graphene with a gate-defined chaotic quantum dot,"We investigate the conductance of an undoped graphene sheet with two metallic
contacts and an electrostatically gated island (quantum dot) between the
contacts. Our analysis is based on the Matrix Green Function formalism, which
was recently adapted to graphene by Titov {\em et al.} [Phys.\ Rev.\ Lett.\
{\bf 104}, 076802 (2010)]. We find pronounced differences between the case of a
stadium-shaped dot (which has chaotic classical dynamics) and a disc-shaped dot
(which has integrable classical dynamics) in the limit that the dot size is
small in comparison to the distance between the contacts. In particular, for
the stadium-shaped dot the two-terminal conductance shows Fano resonances as a
function of the gate voltage, which cross-over to Breit-Wigner resonances only
in the limit of completely separated resonances, whereas for a disc-shaped dot
sharp Breit-Wigner resonances resulting from higher angular momentum remain
present throughout.",1106.3535v2
2011-06-20,Density Functional Resonance Theory of Unbound Electronic Systems,"Density Functional Resonance Theory (DFRT) is a complex-scaled version of
ground-state Density Functional Theory (DFT) that allows one to calculate the
resonance energies and lifetimes of metastable anions. In this formalism, the
exact energy and lifetime of the lowest-energy resonance of unbound systems is
encoded into a complex ""density"" that can be obtained via complex-coordinate
scaling. This complex density is used as the primary variable in a DFRT
calculation just as the ground-state density would be used as the primary
variable in DFT. As in DFT, there exists a mapping of the N-electron
interacting system to a Kohn-Sham system of N non-interacting particles in
DFRT. This mapping facilitates self consistent calculations with an initial
guess for the complex density, as illustrated with an exactly-solvable model
system. Whereas DFRT yields in principle the exact resonance energy and
lifetime of the interacting system, we find that neglecting the
complex-correlation contribution leads to errors of similar magnitude to those
of standard scattering close-coupling calculations under the bound-state
approximation.",1106.3911v1
2011-06-22,X-ray polarization: General formalism and polarization analysis,"The polarization of x-rays plays an outstanding role in experimental
techniques such as non-resonant magnetic x-ray scattering and resonant x-ray
scattering of magnetic and multipolar order. Different instrumental methods
applied to synchrotron light can transform its natural polarization into an
arbitrary polarization state. Several synchrotron applications, in particular
in the field of magnetic and resonant scattering rely on the improvement in the
signal/noise ratio or the deeper insight into the ordered state and the
scattering process made possible through these polarization techniques. Here,
we present the mathematical framework for the description of fully and
partially polarized x-rays, with some applications such as linear x-ray
polarization analysis for the determination of the scattered beam's
polarization, and the Ge K-edge resonant scattering.",1106.4446v1
2011-07-04,"Resonances for ""large"" ergodic systems in one dimension: a review","The present note reviews recent results on resonances for one-dimensional
quantum ergodic systems constrained to a large box. We restrict ourselves to
one dimensional models in the discrete case. We consider two type of ergodic
potentials on the half-axis, periodic potentials and random potentials. For
both models, we describe the behavior of the resonances near the real axis for
a large typical sample of the potential. In both cases, the linear density of
their real parts is given by the density of states of the full ergodic system.
While in the periodic case, the resonances distribute on a nice analytic curve
(once their imaginary parts are suitably renormalized), In the random case, the
resonances (again after suitable renormalization of both the real and imaginary
parts) form a two dimensional Poisson cloud.",1107.0534v1
2011-07-11,Two-Photon Scattering by a Cavity-Coupled Two-Level Emitter in a One-Dimensional Waveguide,"We show that two-photon transport can be modulated by a two-level emitter
coupled to a cavity in a one-dimensional waveguide. In the ordinary case, the
transmitted light has a wider frequency spectrum than the situation without the
cavity because it is reflected and scattered many times. But when the two
photons are resonant with the cavity resonance reflection frequency, the
frequency spectrum of the transmitted light becomes narrower than that without
the cavity. This means that properly tuning the cavity resonance frequency can
improve the photon-photon interaction. In addition, we show that the two-photon
intensity correlation functions are nearly opposite to each other at the two
sides of the emitter transition frequency rather than be the same, which is
exactly the Fano resonance line shape for two photons. Such an effect is
important for lowering the power threshold in optical bistable devices and for
sensing applications. When the emitter transition frequency equals to the
cavity resonance frequency for a high-Q cavity, our results agree with the
recent experiments and theories.",1107.1934v2
2011-07-17,"The gap amplification at a ""shape resonance"" in a superlattice of quantum stripes: a mechanism for high Tc","The amplification of the superconducting critical temperature Tc from the low
temperature range in homogeneous 2D planes (Tc<23 K) to the high temperature
range (23 K<Tc<150 K) in an artificial heterostructure of quantum stripes is
calculated. The high Tc is obtained by tuning the chemical potential near the
bottom of the nth subband at a ""shape resonance"", in a range, whithin the
energy cutoff for the pairing interaction. The resonance for the gap at the nth
""shape resonance"" is studied for a free electron gas in the BCS approximation
as a function of the stripe width L, and of the number of electrons {\rho} per
unit surface. An amplification factor for coupling 0.1<{\lambda}<0.3 is
obtained at the third shape resonance raising the critical temperature in the
high Tc range.",1107.3292v1
2011-07-19,Quantum resonant effect of the strongly-driven spin-boson model,"In this paper we discuss both analytically and numerically the rich quantum
dynamics of the spin-boson model driven by a time-independent field of photon.
Interestingly, we predict a new Rabi oscillation, whose period is inversely
proportional to the driving amplitude. More surprisingly, some nonzero resonant
peaks are found for some special values of the \emph{strong} driving regime.
Moreover, for the different resonant positions, the peaks have different
values. Thus, an important application of this resonance effect is to realize
the precision measurement of the relative parameters in experiment. We also
illustrate that this resonant effect arises from the interference of the
nontrivial periodic phase factors induced by the evolution of the coherent
states in two different subspaces. Our predictions may be, in principle,
observed in the solid-state cavity quantum electrodynamics with the ultrastrong
coupling if the driving magnitude of the photon field is sufficiently large.",1107.3634v1
2011-07-24,Search for Resonances in the Dijet Mass Spectrum from 7 TeV pp Collisions at CMS,"A search for narrow resonances with a mass of at least 1 TeV in the dijet
mass spectrum is performed using pp collisions at sqrt(s)=7 TeV corresponding
to an integrated luminosity of 1 inverse femtobarn, collected by the CMS
experiment at the LHC. No resonances are observed. Upper limits at the 95%
confidence level are presented on the product of the resonance cross section,
branching fraction into dijets, and acceptance, separately for decays into
quark-quark, quark-gluon, and gluon-gluon pairs. The data exclude new particles
predicted in the following models at the 95% confidence level: string
resonances with mass less than 4.00 TeV, E6 diquarks with mass less than 3.52
TeV, excited quarks with mass less than 2.49 TeV, axigluons and colorons with
mass less than 2.47 TeV, and W' bosons with mass less than 1.51 TeV.",1107.4771v1
2011-07-25,A search for resonant production of $t\bar{t}$ pairs in $4.8\ \rm{fb}^{-1}$ of integrated luminosity of $p\bar{p}$ collisions at $\sqrt{s}=1.96\ \rm{TeV}$,"We search for resonant production of tt pairs in 4.8 fb^{-1} integrated
luminosity of ppbar collision data at sqrt{s}=1.96 TeV in the lepton+jets decay
channel, where one top quark decays leptonically and the other hadronically. A
matrix element reconstruction technique is used; for each event a probability
density function (pdf) of the ttbar candidate invariant mass is sampled. These
pdfs are used to construct a likelihood function, whereby the cross section for
resonant ttbar production is estimated, given a hypothetical resonance mass and
width. The data indicate no evidence of resonant production of ttbar pairs. A
benchmark model of leptophobic Z \rightarrow ttbar is excluded with m_{Z'} <
900 GeV at 95% confidence level.",1107.5063v3
2011-08-08,P11 Resonances with Dubna-Mainz-Taipei Dynamical Model for pi-N Scattering and Pion Electromagnetic Production,"We present the results on P11 resonances obtained with Dubna-Mainz-Taipei
(DMT) dynamical model for pion-nucleon scattering and pion electromagnetic
production. The extracted values agree well, in general, with PDG values. One
pole is found corresponding to the Roper resonance and two more resonances are
definitely needed in DMT model. We further find indication for a narrow P11
resonance at around 1700 MeV with a width of around 50 MeV in both pi-N and
gamma-pi reactions.",1108.1673v1
2011-08-11,Identifying the colour of TeV-scale resonances,"We explore how the colour of any new TeV-scale resonances that decay into top
quark pairs can be identified by studying the dependence of the observed
cross-section on a central jet veto. To facilitate this study, colour octet
resonance production was implemented in Pythia8 and colour singlet resonance
production is simulated after minor modifications. We find that the colour of a
2 TeV resonance can be identified with 10/fb of data at a centre-of-mass energy
of 14 TeV for a wide range of couplings, but only if the uncertainty in the
theoretical prediction is dramatically reduced from its current level.",1108.2396v2
2011-08-16,High Q electromechanics with InAs nanowire quantum dots,"In this report, we study electromechanical properties of a suspended InAs
nanowire (NW) resonator. At low temperatures, the NW acts as the island of a
single electron transistor (SET) and we observe a strong coupling between
electrons and mechanical modes at resonance; the rate of electron tunneling is
approximately 10 times the resonant frequency. Above and below the mechanical
resonance, the magnitude of Coulomb peaks is different and we observe Fano
resonance in conductance due to the interference between two contributions to
potential of the SET. The quality factor ($Q$) of these devices is observed
$\sim10^5$ at 100 mK.",1108.3255v1
2011-08-16,Strong decay of low-lying $S_{11}$ and $D_{13}$ nucleon resonances to pseudoscalar mesons and octet baryons,"Partial decay widths of the nucleon resonances $S_{11}(1535)$,
$S_{11}(1650)$, $D_{13}(1520)$ and $D_{13}(1700)$ to the pseudoscalar mesons
and octet baryons are studied within a chiral constituent quark model. The
effects of the configurations mixing between the states $|N^{2}_{8}P_{M}>$ and
$|N^{4}_{8}P_{M}>$ are considered, taking into account the breakdown of the
$SU(6)\otimes O(3)$ symmetry. In addition, possible contributions of the
strangeness components in the $S_{11}$ resonances are investigated.
Experimental data for the partial decay widths of the $S_{11}$ and $D_{13}$
resonances are well reproduced. Predictions for coupling constants of the four
nucleon resonances to pseudoscalar mesons and octet baryons, crucial issues in
the photo- and hadron-induced meson production reactions, are reported.",1108.3282v2
2011-08-17,Microscopic examination of hot spots giving rise to nonlinearity in superconducting resonators,"We investigate the microscopic origins of nonlinear rf response in
superconducting electromagnetic resonators. Strong nonlinearity appearing in
the transmission spectra at high input powers manifests itself through the
emergence of jumplike features near the resonant frequency that evolve toward
lower quality factor with higher insertion loss as the rf input power is
increased. We directly relate these characteristics to the dynamics of
localized normal regions (hot spots) caused by microscopic features in the
superconducting material making up the resonator. A clear observation of
hot-spot formation inside a Nb thin film self-resonant structure is presented
by employing the microwave laser scanning microscope, and a direct link between
microscopic and macroscopic manifestations of nonlinearity is established.",1108.3378v2
2011-08-30,Graphene-based tortional resonator from molecular dynamics simulation,"Molecular dynamics simulations are performed to study graphene-based
torsional mechanical resonators. The quality factor is calculated by
$Q_{F}=\omega\tau/2\pi$, where the frequency $\omega$ and life time $\tau$ are
obtained from the correlation function of the normal mode coordinate. Our
simulations reveal the radius-dependence of the quality factor as
$Q_{F}=2628/(22R^{-1}+0.004R^{2})$, which yields a maximum value at some proper
radius $R$. This maximum point is due to the strong boundary effect in the
torsional resonator, as disclosed by the temperature distribution in the
resonator. Resulting from the same boundary effect, the quality factor shows a
power law temperature-dependence with power factors bellow 1.0. The theoretical
results supply some valuable information for the manipulation of the quality
factor in future experimental devices based on the torsional mechanical
resonator.",1108.5805v2
2011-09-06,Microwave cavity-enhanced transduction for plug and play nanomechanics at room temperature,"Nanomechanical resonators with increasingly high quality factors are enabled
following recent insights into energy storage and loss mechanisms in
nanoelectromechanical systems (NEMS). Consequently, efficient, non-dissipative
transduction schemes are required to avoid the dominating influence of coupling
losses. We present an integrated NEMS transducer based on a microwave cavity
dielectrically coupled to an array of doubly-clamped pre-stressed silicon
nitride beam resonators. This cavity-enhanced detection scheme allows resolving
the resonators' Brownian motion at room temperature while preserving their high
mechanical quality factor of 290,000 at 6.6 MHz. Furthermore, our approach
constitutes an ""opto""mechanical system in which backaction effects of the
microwave field are employed to alter the effective damping of the resonators.
In particular, cavity-pumped self-oscillation yields a linewidth of only 5 Hz.
Thereby, an adjustement-free, all-integrated and self-driven
nanoelectromechanical resonator array interfaced by just two microwave
connectors is realised, potentially useful for applications in sensing and
signal processing.",1109.1156v2
2011-09-10,Entanglement Evolution via Quantum Resonances,"We consider two qubits interacting with local and collective thermal
reservoirs. Each spin-reservoir interaction consists of an energy exchange and
an energy conserving channel. We prove a resonance representation of the
reduced dynamics of the spins, valid for all times t>=0, with errors (small
interaction) estimated rigorously, uniformly in time. Subspaces associated to
non-interacting energy differences evolve independently, partitioning the
reduced density matrix into dynamically decoupled clusters of jointly evolving
matrix elements. Within each subspace the dynamics is markovian with a
generator determined entirely by the resonance data of the full Hamiltonian.
Based on the resonance representation we examine the evolution of entanglement
(concurrence). We show that, whenever thermalization takes place, entanglement
of any initial state dies out in a finite time and will not return. For a
concrete class of initially entangled spin states we find explicit bounds on
entanglement survival and death times in terms of the initial state and the
resonance data.",1109.2235v1
2011-09-22,Quantum noise and mode nonorthogonality in nonhermitian PT-symmetric optical resonators,"PT-symmetric optical resonators combine absorbing regions with active,
amplifying regions. The latter are the source of radiation generated via
spontaneous and stimulated emission, which embodies quantum noise and can
result in lasing. We calculate the frequency-resolved output radiation
intensity of such systems and relate it to a suitable measure of excess noise
and mode nonorthogonality. The lineshape differs depending on whether the
emission lines are isolated (as for weakly amplifying, almost hermitian
systems) or overlapping (as for the almost degenerate resonances in the
vicinity of exceptional points associated to spontaneous PT-symmetry breaking).
The calculations are carried out in the scattering input-output formalism, and
are illustrated for a quasi one-dimensional resonator set-up. In our
derivations we also allow for the more general case of a resonator in which the
amplifying and absorbing regions are not related by symmetry.",1109.4932v1
2011-09-23,Non-demolition Adiabatic Measurement of the Phase Qubit State,"An adiabatic method for a single-shot non-demolition measurement of the phase
qubit is suggested. The qubit is inductively coupled to a low-frequency
resonator, which in turn is connected with a classical measurement device
(phase meter). The resonator drives adiabatic oscillations of the supercurrent
in the qubit loop. The back reaction of the qubit loop on the resonator depends
on the qubit state. Measuring the phase shift of the resonator's oscillations
one can determine the state of the qubit. Numerical computations with available
experimental parameters show that the phase difference between the two qubit
states increases at a rate of 0.0044 rad/ns with the fidelity of about 0.9989
and the measurement time of about 100 ns. The fidelity of the measurement is
estimated taking into consideration possible quantum transitions inside and
outside the qubit manifold. An increase of the phase difference is possible but
it is linked to a reduction of the fidelity. The requirements for the
reproducibility of the qubit and resonator parameters are formulated.",1109.5170v1
2011-10-06,Competition of resonant and nonresonant paths in resonance-enhanced two-photon single ionization of He by an ultrashort extreme-ultraviolet pulse,"We theoretically study the pulse-width dependence of the photoelectron
angular distribution (PAD) from the resonance-enhanced two-photon single
ionization of He by femtosecond ($\lesssim 20$ fs) extreme-ultraviolet pulses,
based on the time-dependent perturbation theory and simulations with the full
time-dependent Schr\""odinger equation. In particular, we focus on the
competition between resonant and nonresonant ionization paths, which leads to
the relative phase $\delta$ between the $S$ and $D$ wave packets distinct from
the corresponding scattering phase shift difference. When the spectrally
broadened pulse is resonant with an excited level, the competition varies with
pulse width, and, therefore, $\delta$ and the PAD also change with it. On the
other hand, when the Rydberg manifold is excited, $\delta$ and the PAD do not
much vary with the pulse width, except for the very short pulse regime.",1110.1139v3
2011-10-19,Continuous-wave Cascaded-Harmonic Generation and Multi-Photon Raman Lasing in Lithium Niobate Whispering-Gallery Resonators,"We report experimental demonstration of continuous-wave cascaded-harmonic
generation and Raman lasing in a millimeter-scale lithium niobate
whispering-gallery resonator pumped at a telecommunication-compatible infrared
wavelength. Intensity enhancement through multiple recirculations in the
whispering-gallery resonator and quasi phase-matching through a nonuniform
crystal poling enable simultaneous cascaded-harmonic generation up to the
fourth-harmonic accompanied by stimulated Raman, two-photon, three-photon, and
four-photon Raman scattering corresponding the molecular vibrational
wavenumbers 632 cm-1 and 255 cm-1 in z-cut lithium niobate at pump power levels
as low as 200mW. We demonstrate simultaneous cascaded-harmonic generation and
Raman lasing by observing the spectrum of the scattered light from the
resonator and by capturing the image of the decoupled light from the resonator
on a color CCD camera.",1110.4394v1
2011-10-20,Circular-Polarization Dependent Cyclotron Resonance in Large-Area Graphene in Ultrahigh Magnetic Fields,"Using ultrahigh magnetic fields up to 170 T and polarized midinfrared
radiation with tunable wavelengths from 9.22 to 10.67 um, we studied cyclotron
resonance in large-area graphene grown by chemical vapor deposition.
Circular-polarization dependent studies reveal strong p-type doping for
as-grown graphene, and the dependence of the cyclotron resonance on radiation
wavelength allows for a determination of the Fermi energy. Thermal annealing
shifts the Fermi energy to near the Dirac point, resulting in the simultaneous
appearance of hole and electron cyclotron resonance in the magnetic quantum
limit, even though the sample is still p-type, due to graphene's linear
dispersion and unique Landau level structure. These high-field studies
therefore allow for a clear identification of cyclotron resonance features in
large-area, low-mobility graphene samples.",1110.4522v2
2011-10-24,Oscillatory coupling between a monolithic whispering-gallery resonator and a buried bus waveguide,"We report on a combined theoretical and experimental study of the optical
coupling between a microdisk resonator and a waveguide laying on different
planes. While the lateral coupling between a planar resonator and a waveguide
is characterized by a unique distance at which the resonant waveguide
transmission vanishes because of destructive interference, the vertical
coupling geometry exhibits an oscillatory behavior in the coupling amplitude as
a function of the vertical gap. This effect manifests experimentally as
oscillations in both the waveguide transmission and the mode quality factor. An
analytical description based on coupled-mode theory and a two-port
beam-splitter model of the waveguide-resonator coupling is developed, which
compares successfully both to experimental data and numerical simulations.",1110.5211v1
2011-10-26,High Frequency Quantum Admittance and Noise Measurement with an On-chip Resonant Circuit,"By coupling a quantum detector, a superconductor-insulator-superconductor
junction, to a Josephson junction \textit{via} a resonant circuit we probe the
high frequency properties, namely the ac complex admittance and the current
fluctuations of the Josephson junction at the resonant frequencies. The
admittance components show frequency dependent singularities related to the
superconducting density of state while the noise exhibits a strong frequency
dependence, consistent with theoretical predictions. The circuit also allows to
probe separately the emission and absorption noise in the quantum regime of the
superconducting resonant circuit at equilibrium. At low temperature the
resonant circuit exhibits only absorption noise related to zero point
fluctuations, whereas at higher temperature emission noise is also present.",1110.5834v2
2011-12-05,Polarons and dressed molecules near narrow Feshbach resonances,"The properties of impurities immersed in a large Fermi sea are naturally
described in terms of dressed quasiparticles: attractive and repulsive
polarons, and dressed molecules. Motivated by recent experiments on narrow
Feshbach resonances, we analyze here how the quasiparticle properties are
affected by a non-zero resonance range. We find two interesting analytic
results. For large range, the ground state energy close to resonance is shown
to become perturbative in the inverse range. In the limit of broad resonance
instead, we provide a new Tan's relation linking the impurity ground state
energy $E_\downarrow$ to the number of atoms in its dressing cloud $\Delta N$.
As a corollary, at unitarity one finds $\Delta N=-E_\downarrow/\epsilon_F $,
with $\epsilon_F$ the Fermi energy of the bath.",1112.1029v2
2011-12-06,Highly Polarized Fermi Gases across a Narrow Feshbach Resonance,"We address the phase of a highly polarized Fermi gas across a narrow Feshbach
resonance starting from the problem of a single down spin fermion immersed in a
Fermi sea of up spins. Both polaron and pairing states are considered using the
variational wave function approach, and we find that the polaron to pairing
transition will take place at the BCS side of the resonance, strongly in
contrast to a wide resonance where the transition is located at the BEC side.
For pairing phase, we find out the critical strength of repulsive interaction
between pairs above which the mixture of pairs and fermions will not phase
separate. Therefore, nearby a narrow resonance, it is quite likely that
magnetism can coexist with s-wave BCS superfluidity at large Zeeman field,
which is a remarkable property absent in conventional BCS superconductors (or
fermion pair superfluids).",1112.1282v3
2011-12-12,Dispersion in media containing resonant inclusions: where does it come from?,"We study the propagation of waves in a quasi 1D homogeneous host medium
filled with various resonators. We first prove that a far field coupling
between the elements explains its dispersive nature. This coupling is
interpreted as a Fano interference between the incoming wave and the waves
re-radiated by each resonator, which experience a phase shift at resonance. We
propose a simple formalism that gives the complete dispersion relation of the
medium in terms of the far field response of a single resonator. We prove that
our approach applies to and unifies various domains such as metamaterials,
hybridization band gap materials and designer's plasmons. Finally we show that
those media, spatially random or organized on a scale larger than the
wavelength, also present very interesting properties, which broadens the range
of man made exotic materials.",1112.2524v1
2011-12-22,Magnetic field induced Fabry-Pérot resonances in helical edge states,"We study electronic transport across a helical edge state exposed to a
uniform magnetic ({$\vec B$}) field over a finite length. We show that this
system exhibits Fabry-P\'erot type resonances in electronic transport. The
intrinsic spin anisotropy of the helical edge states allows us to tune these
resonances by changing the direction of the {$\vec B$} field while keeping its
magnitude constant. This is in sharp contrast to the case of non-helical one
dimensional electron gases with a parabolic dispersion, where similar
resonances do appear in individual spin channels ($\uparrow$ and $\downarrow$)
separately which, however, cannot be tuned by merely changing the direction of
the {$\vec B$} field. These resonances provide a unique way to probe the
helical nature of the theory.",1112.5400v2
2011-12-27,Realization of a Resonant Fermi Gas with a Large Effective Range,"We have measured the interaction energy and three-body recombination rate for
a two-component Fermi gas near a narrow Feshbach resonance and found both to be
strongly energy dependent. Even for deBroglie wavelengths greatly exceeding the
van der Waals length scale, the behavior of the interaction energy as a
function of temperature cannot be described by atoms interacting via a contact
potential. Rather, energy-dependent corrections beyond the scattering length
approximation are required, indicating a resonance with an anomalously large
effective range. For fields where the molecular state is above threshold, the
rate of three-body recombination is enhanced by a sharp, two-body resonance
arising from the closed-channel molecular state which can be magnetically tuned
through the continuum. This narrow resonance can be used to study strongly
correlated Fermi gases that simultaneously have a sizeable effective range and
a large scattering length.",1112.5977v1
2012-02-03,Coupling between quantum Hall state and electromechanics in suspended graphene resonator,"Using graphene resonator, we perform electromechanical measurements in
quantum Hall regime to probe the coupling between a quantum Hall (QH) system
and its mechanical motion. Mechanically perturbing the QH state through
resonance modifies the DC resistance of the system and results in a
Fano-lineshape due to electronic interference. Magnetization of the system
modifies the resonator's equilibrium position and effective stiffness leading
to changes in resonant frequency. Our experiments show that there is an
intimate coupling between the quantum Hall state and mechanics - electron
transport is affected by physical motion and in turn the magnetization modifies
the electromechanical response.",1202.0669v1
2012-02-03,Tailoring Light-Matter Interaction with a Nanoscale Plasmon Resonator,"We propose and demonstrate a new approach for achieving strong light-matter
interactions with quantum emitters. Our approach makes use of a plasmon
resonator composed of defect-free, highly crystalline silver nanowires
surrounded by patterned dielectric distributed Bragg reflectors (DBRs). These
resonators have an effective mode volume (Veff) two orders of magnitude below
the diffraction limit and quality factor (Q) approaching 100, enabling
enhancement of spontaneous emission rates by a factor exceeding 75 at the
cavity resonance. We also show that these resonators can be used to convert a
broadband quantum emitter to a narrowband single-photon source with
color-selective emission enhancement.",1202.0829v1
2012-02-06,Feshbach spectroscopy and scattering properties of ultracold Li+Na mixtures,"We have observed 26 interspecies Feshbach resonances at fields up to 2050 G
in ultracold $^6$Li+$^{23}$Na mixtures for different spin-state combinations.
Applying the asymptotic bound-state model to assign the resonances, we have
found that most resonances have d-wave character. This analysis serves as
guidance for a coupled-channel calculation, which uses modified interaction
potentials to describe the positions of the Feshbach resonances well within the
experimental uncertainty and to calculate their widths. The scattering length
derived from the improved interaction potentials is experimentally confirmed
and deviates from previously reported values in sign and magnitude. We give
prospects for $^7$Li+$^{23}$Na and predict broad Feshbach resonances suitable
for tuning.",1202.1199v2
2012-02-21,Extremely Low-Loss Acoustic Phonons in a Quartz Bulk Acoustic Wave Resonator at Millikelvin Temperature,"Low-loss, high frequency acoustic resonators cooled to millikelvin
temperatures are a topic of great interest for application to hybrid quantum
systems. When cooled to 20 mK, we show that resonant acoustic phonon modes in a
Bulk Acoustic Wave (BAW) quartz resonator demonstrate exceptionally low loss
(with $Q$-factors of order billions) at frequencies of 15.6 and 65.4 MHz, with
a maximum $f.Q$ product of 7.8$\times10^{16}$ Hz. Given this result, we show
that the $Q$-factor in such devices near the quantum ground state can be four
orders of magnitude better than previously attained. Such resonators possess
the low losses crucial for electromagnetic cooling to the phonon ground state,
and the possibility of long coherence and interaction times of a few seconds,
allowing multiple quantum gate operations.",1202.4556v2
2012-02-22,Subsurface impurities and vacancies in a three-dimensional topological insulator,"Using a three-dimensional microscopic lattice model of a strong topological
insulator (TI) we study potential impurities and vacancies in surface and
subsurface positions. For all impurity locations we find impurity-induced
resonance states with energy proportional to the inverse of the impurity
strength, although the impurity strength needed for a low-energy resonance
state increases with the depth of the impurity. For strong impurities and
vacancies as deep as 15 layers into the material, resonance peaks will appear
at and around the Dirac point in the surface energy spectrum, splitting the
original Dirac point into two nodes located off-center. Furthermore, we study
vacancy clusters buried deep inside the bulk and find zero-energy resonance
states for both single and multiple-site vacancies. Only fully symmetric
multiple-site vacancy clusters show resonance states expelled from the bulk
gap.",1202.4872v2
2012-02-22,Temperature dependence of the resonance and low energy spin excitations in superconducting FeTe$_{0.6}$Se$_{0.4}$,"We use inelastic neutron scattering to study the temperature dependence of
the low-energy spin excitations in single crystals of superconducting
FeTe$_{0.6}$Se$_{0.4}$ ($T_c=14$ K). In the low-temperature superconducting
state, the imaginary part of the dynamic susceptibility at the electron and
hole Fermi surfaces nesting wave vector $Q=(0.5,0.5)$,
$\chi^{\prime\prime}(Q,\omega)$, has a small spin gap, a two-dimensional
neutron spin resonance above the spin gap, and increases linearly with
increasing $\hbar\omega$ for energies above the resonance. While the intensity
of the resonance decreases like an order parameter with increasing temperature
and disappears at temperature slightly above $T_c$, the energy of the mode is
weakly temperature dependent and vanishes concurrently above $T_c$. This
suggests that in spite of its similarities with the resonance in electron-doped
superconducting BaFe$_{2-x}$(Co,Ni)$_x$As$_2$, the mode in
FeTe$_{0.6}$Se$_{0.4}$ is not directly associated with the superconducting
electronic gap.",1202.5015v1
2012-02-25,Near-Field Resonance at Far-Field Anti-Resonance: Plasmonically Enhanced Light Emission with Minimum Scattering Nanoantennas,"We demonstrate that a periodic array of optical antennas sustains a resonant
Near-Field (NF) and an anti-resonant Far-Field (FF) at the same energy and
in-plane momentum. This phenomenon arises in the context of coupled plasmonic
lattice resonances, whose bright and dark character is interchanged at a
critical antenna length. The energies of these modes anti-cross in the FF, but
cross in the NF. Hence, we observe an extremely narrow bandwidth emission
enhancement from quantum dots in the proximity of the array, while the antennas
scatter minimally into the FF. Simulations reveal that a standing wave with a
quadrupolar field distribution is the origin of this dark collective resonance.",1202.5681v1
2012-02-29,Trace formula for chaotic dielectric resonators tested with microwave experiments,"We measured the resonance spectra of two stadium-shaped dielectric microwave
resonators and tested a semiclassical trace formula for chaotic dielectric
resonators proposed by Bogomolny et al. [Phys. Rev. E 78, 056202 (2008)]. We
found good qualitative agreement between the experimental data and the
predictions of the trace formula. Deviations could be attributed to missing
resonances in the measured spectra in accordance with previous experiments
[Phys. Rev. E 81, 066215 (2010)]. The investigation of the numerical length
spectrum showed good qualitative and reasonable quantitative agreement with the
trace formula. It demonstrated, however, the need for higher-order corrections
of the trace formula. The application of a curvature correction to the Fresnel
reflection coefficients entering the trace formula yielded better agreement,
but deviations remained, indicating the necessity of further investigations.",1202.6568v2
2012-03-04,Stamp transferred suspended graphene mechanical resonators for radio-frequency electrical readout,"We present a simple micromanipulation technique to transfer suspended
graphene flakes onto any substrate and to assemble them with small localized
gates into mechanical resonators. The mechanical motion of the graphene is
detected using an electrical, radio-frequency (RF) reflection readout scheme
where the time-varying graphene capacitor reflects a RF carrier at f=5-6 GHz
producing modulation sidebands at f +/- fm. A mechanical resonance frequency up
to fm=178 MHz is demonstrated. We find both hardening/softening Duffing effects
on different samples, and obtain a critical amplitude of ~40 pm for the onset
of nonlinearity in graphene mechanical resonators. Measurements of the quality
factor of the mechanical resonance as a function of DC bias voltage Vdc
indicate that dissipation due to motion-induced displacement currents in
graphene electrode is important at high frequencies and large Vdc.",1203.0764v1
2012-03-04,An Exactly Solvable Model for Nonlinear Resonant Scattering,"This work analyzes the effects of cubic nonlinearities on certain resonant
scattering anomalies associated with the dissolution of an embedded eigenvalue
of a linear scattering system. These sharp peak-dip anomalies in the frequency
domain are often called Fano resonances. We study a simple model that
incorporates the essential features of this kind of resonance. It features a
linear scatterer attached to a transmission line with a point-mass defect and
coupled to a nonlinear oscillator. We prove two power laws in the small
coupling <gamma> \to 0 and small nonlinearity <mu> \to 0 regime. The asymptotic
relation <mu> ~ C<gamma>^4 characterizes the emergence of a small frequency
interval of triple harmonic solutions near the resonant frequency of the
oscillator. As the nonlinearity grows or the coupling diminishes, this interval
widens and, at the relation <mu> ~ C<gamma>^2, merges with another evolving
frequency interval of triple harmonic solutions that extends to infinity. Our
model allows rigorous computation of stability in the small <mu> and <gamma>
limit. In the regime of triple harmonic solutions, those with largest and
smallest response of the oscillator are linearly stable and the solution with
intermediate response is unstable.",1203.1587v1
2012-03-13,Antiferroelectric resonance in noncentrosymmetric multi-sublattice magnets,"We predict the phenomenon of antiferroelectric resonance (AFER), in which an
ac electric field causes magnetic ions located at noncentrosymmetric positions
in a multi-sublattice magnet to undergo magnetic transitions corresponding to
exchange collective excitations of the system. We construct a theory of such
resonances, and show that in magnets with collinear magnetic structures AFER is
caused by relativistic and exchange-relativistic magnetoelectric interactions,
while in the noncollinear magnets a significant contribution can also come from
the exchange magnetoelectric interaction. We predict an exchange enhancement of
the resonance by exchange modes, and discuss the role of AFER in causing
resonant enhancement of magnetooptical phenomena. The main results of our
theory are illustrated with the four-sublattice rhombohedral antiferromagnets
{\alpha}-Fe_2O_3 and Cr_2O_3, as examples.",1203.2731v1
2012-03-16,On the top-antitop invariant mass spectrum at the LHC from a Higgs boson signal perspective,"We investigate the effect of one-loop corrections of ${\cal
O}(\alpha_S^2\alpha_W)$ on the $t\bar t$ invariant mass spectrum at the Large
Hadron Collider (LHC) in presence of both resonant and non-resonant Higgs boson
effects. We show that corrections of ${\cal O}(\alpha_S^2\alpha_W)$ involving a
non-resonant Higgs boson are comparable to or even larger than those involving
interference with the s-channel resonant Higgs boson amplitude and that both of
these are subleading with respect to all other (non-Higgs) diagrams through
that order. We also compute the contribution through ${\cal
O}(\alpha_S^2\alpha_W^2)$ of resonant Higgs boson production (i.e. Higgs
production via $gg$ fusion) as well as the pure QCD ones of ${\cal
O}(\alpha_S^3)$. Altogether, we show that the well known peak-dip structure of
the $M_{t\bar t}$ spectrum emerging from interference effects between the
$t,u$-channel $gg$-induced Leading Order (LO) QCD diagrams and the one due to a
Higgs boson in s-channel via $gg$-fusion is drastically swamped by the
remainder of the terms of ${\cal O}(\alpha_S^2\alpha_W)$ discussed above.",1203.3746v1
2012-03-19,Anisotropy induced Feshbach resonances in a quantum dipolar gas of magnetic atoms,"We explore the anisotropic nature of Feshbach resonances in the collision
between ultracold magnetic submerged-shell dysprosium atoms, which can only
occur due to couplings to rotating bound states. This is in contrast to
well-studied alkali-metal atom collisions, where most Feshbach resonances are
hyperfine induced and due to rotation-less bound states. Our novel
first-principle coupled-channel calculation of the collisions between
open-4f-shell spin-polarized bosonic dysprosium reveals a striking correlation
between the anisotropy due to magnetic dipole-dipole and electrostatic
interactions and the Feshbach spectrum as a function of an external magnetic
field. Over a 20 mT magnetic field range we predict about a dozen Feshbach
resonances and show that the resonance locations are exquisitely sensitive to
the dysprosium isotope.",1203.4172v1
2012-03-23,Control of quantum interference in molecular junctions: Understanding the origin of Fano and anti- resonances,"We investigate within a coarse-grained model the conditions leading to the
appearance of Fano resonances or anti-resonances in the conductance spectrum of
a generic molecular junction with a side group (T-junction). By introducing a
simple graphical representation (parabolic diagram), we can easily visualize
the relation between the different electronic parameters determining the
regimes where Fano resonances or anti-resonances in the low-energy conductance
spectrum can be expected. The results obtained within the coarse-grained model
are validated using density-functional based quantum transport calculations in
realistic T-shaped molecular junctions.",1203.5269v4
2012-03-25,Simple protocol for generating W states in resonator-based quantum computing architectures,"We describe a simple, practical scheme for generating multi-qubit W states in
resonator-based architectures, in which N Josephson phase qubits are
capacitively coupled to a common resonator bus. The entire control sequence
consists of three pulses: a local Rabi pulse that excites a single qubit in the
circuit; a coupling pulse that transfers the qubit excitation to the resonator
bus; and the main, entangling operation that simultaneously couples the bus to
all N qubits. If the qubit-resonator coupling strength g is much smaller than
the qubit energy splitting, the system initially excited into the
near-degenerate single-excitation subspace stays within that subspace, while
smoothly evolving toward the fully uniform W state superposition. The duration
of the final entangling operation is found to decrease with the total number of
the qubits according to t = pi/[2gN^(1/2)], in agreement with some of the
previously proposed cavity QED W state generation schemes.",1203.5534v1
2012-03-30,Statistical Aspects of Ultracold Resonant Scattering,"Compared to purely atomic collisions, ultracold collisions involving
molecules have the potential to support a much larger number of Fano-Feshbach
resonances due to the huge amount of ro-vibrational states available. In order
to handle such ultracold atom-molecule collisions, we formulate a theory that
incorporates the ro-vibrational Fano-Feshbach resonances in a statistical
manner while treating the physics of the long-range scattering, which is
sensitive to such things as hyperfine states, collision energy and any applied
electromagnetic fields, exactly within multichannel quantum defect theory.
Uniting these two techniques, we can assess the influence of highly resonant
scattering in the threshold regime, and in particular its dependence on the
hyperfine state selected for the collision. This allows us to explore the onset
of Ericson fluctuations in the regime of overlapping resonances, which are
well-known in nuclear physics but completely unexplored in the ultracold
domain.",1203.6868v1
2012-06-22,Breaking the cavity linewidth limit of resonant optical modulators,"Microring optical modulators are being explored extensively for
energy-efficient photonic communication networks in future high-performance
computing systems and microprocessors, because they can significantly reduce
the power consumption of optical transmitters via the resonant circulation of
light. However, resonant modulators have traditionally suffered from a
trade-off between their power consumption and maximum operation bit rate, which
were thought to depend oppositely upon the cavity linewidth. Here, we break
this linewidth limitation using a silicon microring. By controlling the rate at
which light enters and exits the microring, we demonstrate modulation free of
the parasitic cavity linewidth limitations at up to 40 GHz, more than 6x the
cavity linewidth. The device operated at 28 Gb/s using single-ended drive
signals less than 1.5 V. The results show that high-Q resonant modulators can
be designed to be simultaneously low-power and high-speed, features which are
mutually incompatible in typical resonant modulators studied to date.",1206.5337v1
2012-07-02,Impact of resonator geometry and its coupling with ground plane on ultrathin metamaterial perfect absorbers,"We investigate the impact of resonator geometry and its coupling with ground
plane on the performance of metamaterial perfect absorbers. Using a
cross-resonator as an example structure, we find that the absorber thickness
can be further reduced through modifying the geometric dimensions of the
resonators. Numerical simulations and theoretical calculations reveal that
destructive interference of multiple reflections is responsible for the
near-unity absorption. The near-field coupling between the resonator array and
ground plane can be significant. When this coupling is taken into account, the
theoretical results calculated using the interference model are in excellent
agreement with experiments and numerical simulations.",1207.0540v1
2012-07-10,Frequency and Q-factor control of nanomechanical resonators,"We present an integrated scheme for dielectric drive and read-out of high-Q
nanomechanical resonators which enables tuning of both the resonance frequency
and quality factor with an applied DC voltage. A simple model for altering
these quantities is derived, incorporating the resonator's complex electric
polarizability and position in an inhomogeneous electric field, which agrees
very well with the experimental findings as well as FEM simulations. By
comparing two sample geometries we are able to show that careful electrode
design can determine the direction of frequency tuning of flexural in- and
out-of-plane modes of a string resonator. Furthermore we demonstrate that the
mechanical quality factor can be voltage reduced more than fivefold.",1207.2403v1
2012-07-28,Scattering resonances in graphene,"We address the two-dimensional band-structure of graphene above the vacuum
level in the context of discrete states immersed in the three-dimensional
continuum. Scattering resonances are discovered that originate from the
coupling of the in-plane and perpendicular motions, as elucidated by the
analysis of an exactly solvable model. Some of the resonances turn into true
bound states at high-symmetry $\kv$ vectors. {\it Ab initio} scattering theory
verifies the existence of the resonances in realistic graphene and shows that
they lead to a total reflection of the incident electron below and total
transmission above the resonance energy.",1207.6702v4
2012-08-01,Many Body Physics with Coupled Transmission Line Resonators,"We present the Josephson junction intersected superconducting transmission
line resonator. In contrast to the Josephson parametric amplifier, Josephson
bifurcation amplifier and Josephson parametric converter we consider the regime
of few microwave photons. We review the derivation of eigenmode frequencies and
zero point fluctuations of the nonlinear transmission line resonator and the
derivation of the eigenmode Kerr nonlinearities. Remarkably these
nonlinearities can reach values comparable to Transmon qubits rendering the
device ideal for accessing the strongly correlated regime. This is particularly
interesting for investigation of quantum many-body dynamics of interacting
particles under the influence of drive and dissipation. We provide current
profiles for the device modes and investigate the coupling between resonators
in a network of nonlinear transmission line resonators.",1208.0134v1
2012-08-02,Ultra-cold Fermi gases with resonant dipole-dipole interaction,"The superfluid phases in the resonant dipolar Fermi gases are investigated by
the standard mean-field theory. In contrast to the crossover from Bose-Einstein
condensation (BEC) to Bardeen-Cooper-Schrieffer (BCS) superfluid in the Fermi
gases with the isotropic interactions, the resonant dipolar interaction leads
to two completely different BEC phases of the tight-binding Fermi molecules on
both sides of the resonance, which are characterized by two order parameters
with the distinct internal symmetries. We point that near the resonance, the
two competitive phases can coexist, and an emergent relative phase between the
two order parameters spontaneously breaks the time-reversal symmetry, which
could be observed in the momentum resolved rf-spectroscopy.",1208.0450v1
2012-08-10,"Combined analysis of eta' production reactions: gamma N -> eta' N, N N -> N N eta', and pi N -> eta' N","The production of eta' mesons in photon- and hadron-induced reactions has
been revisited in view of the recent additions of high-precision data to the
world data base. Based on an effective Lagrangian approach, we have performed a
combined analysis of the free and quasi-free gamma N -> eta' N, N N -> N N
eta', and pi N -> eta' N reactions. Considering spin-1/2 and -3/2 resonances,
we found that a set of above-threshold resonances {S_{11}, P_{11}, P_{13}},
with fitted mass values of about M_R=1925, 2130, and 2050 MeV, respectively,
and the four-star sub-threshold P_{13}(1720) resonance reproduce best all
existing data for the eta' production processes in the resonance-energy region
considered in this work. All three above-threshold resonances found in the
present analysis are essential and indispensable for the good quality of the
present fits.",1208.2279v2
2012-08-14,Origin of the second peak in the cross section of the $K^+Λ$ photoproduction,"By using a covariant isobar model and the latest experimental data we have
analyzed the role of the $P_{13}(1900)$ and $D_{13}(2080)$ resonances in the
kaon photoproduction process $\gamma p\to K^+\Lambda$. Special attention has
been paid to the region where the second peak in the cross section is located,
i.e. at total c.m. energies around 1.9 GeV. It is found that this peak
originates mostly from the $P_{13}(1900)$ resonance contribution. Although the
contribution of the $D_{13}(2080)$ resonance is not negligible, it is much
smaller than that of the $P_{13}(1900)$ state. Our finding confirms that the
$P_{13}(1900)$ resonance is also important in explaining the beam-recoil double
polarization data $C_x$ and $C_z$, provided that the mass and the width of this
resonance are 1871 and 131 MeV, respectively.",1208.2780v1
2012-08-17,Spin-wave excitations and superconducting resonant mode in Cs(x)Fe(2-y)Se2,"We report neutron inelastic scattering measurements on the normal and
superconducting states of single-crystalline Cs0.8Fe1.9Se2. Consistent with
previous measurements on Rb(x)Fe(2-y)Se2, we observe two distinct spin
excitation signals: (i) spin-wave excitations characteristic of the block
antiferromagnetic order found in insulating A(x)Fe(2-y)Se2 compounds, and (ii)
a resonance-like magnetic peak localized in energy at 11 meV and at an in-plane
wave vector of (0.25, 0.5). The resonance peak increases below Tc = 27 K, and
has a similar absolute intensity to the resonance peaks observed in other
Fe-based superconductors. The existence of a magnetic resonance in the spectrum
of Rb(x)Fe(2-y)Se2 and now of Cs(x)Fe(2-y)Se2 suggests that this is a common
feature of superconductivity in this family. The low energy spin-wave
excitations in Cs0.8Fe1.9Se2 show no measurable response to superconductivity,
consistent with the notion of spatially separate magnetic and superconducting
phases.",1208.3610v2
2012-08-31,Coherence assisted resonance with sub-lifetime-limited linewidth,"We demonstrate a novel approach to obtain resonance linewidth below that
limited by coherence lifetime. Cross correlation between induced intensity
modulation of two lasers coupling the target resonance exhibits a narrow
spectrum. 1/30 of the lifetime-limited width was achieved in a
proof-of-principle experiment where two ground states are the target resonance
levels. Attainable linewidth is only limited by laser shot noise in principle.
Experimental results agree with an intuitive analytical model and numerical
calculations qualitatively. This technique can be easily implemented and should
be applicable to many atomic, molecular and solid state spin systems for
spectroscopy, metrology and resonance based sensing and imaging.",1208.6340v1
2012-09-07,Coupling carbon nanotube mechanics to a superconducting circuit,"The quantum behaviour of mechanical resonators is a new and emerging field
driven by recent experiments reaching the quantum ground state. The high
frequency, small mass, and large quality-factor of carbon nanotube resonators
make them attractive for quantum nanomechanical applications. A common element
in experiments achieving the resonator ground state is a second quantum system,
such as coherent photons or superconducting device, coupled to the resonators
motion. For nanotubes, however, this is a challenge due to their small size.
Here, we couple a carbon nanoelectromechanical (NEMS) device to a
superconducting circuit. Suspended carbon nanotubes act as both superconducting
junctions and moving elements in a Superconducting Quantum Interference Device
(SQUID). We observe a strong modulation of the flux through the SQUID from
displacements of the nanotube. Incorporating this SQUID into superconducting
resonators and qubits should enable the detection and manipulation of nanotube
mechanical quantum states at the single-phonon level.",1209.1514v1
2012-09-08,Scale free networks of superconducting striped grains tuned at Fano resonances for high Tc,"Controlling lattice complexity or inhomogeneity of the doped oxide
superconductors is shown to be a key term for control of the superconductivity
critical temperature. All high temperature superconductors show anisotropic
gaps and/or multi-gap superconductivity in the clean limit. They show the shape
resonance in superconducting gaps that is a type of Fano resonance driven by
the Josephson-like term for pairs transfer. These resonances occur where one of
the multiple Fermi surface spots is near a 2.5 Lifshitz transition. The Fano
antiresonance occurs between a BCS condensate and a BEC-like condensate. In a
system near a 2.5 Lifshitz transition the lattice is close to an instability.
This drives to the formation of a granular superconducting phase made of a
charge density metal formed by puddles of ordered oxygen interstitials or
ordered local lattice distortions (static short range charge density waves)
detected by scanning nano-x-ray diffraction imaging. We show that the scale
free networks of superconducting grains tuned to a Fano resonance is an
essential feature of high temperature superconductors that favours high Tc.",1209.1723v1
2012-09-12,Double-resonant fast particle-wave interaction,"In future fusion devices fast particles must be well confined in order to
transfer their energy to the background plasma. Magnetohydrodynamic
instabilities like Toroidal Alfv\'en Eigenmodes or core-localized modes such as
Beta Induced Alfv\'en Eigenmodes and Reversed Shear Alfv\'en Eigenmodes, both
driven by fast particles, can lead to significant losses. This is observed in
many ASDEX Upgrade discharges. The present study applies the drift-kinetic
HAGIS code with the aim of understanding the underlying resonance mechanisms,
especially in the presence of multiple modes with different frequencies. Of
particular interest is the resonant interaction of particles simultaneously
with two different modes, referred to as 'double-resonance'. Various mode
overlapping scenarios with different q profiles are considered. It is found
that, depending on the radial mode distance, double-resonance is able to
enhance growth rates as well as mode amplitudes significantly. Surprisingly, no
radial mode overlap is necessary for this effect. Quite the contrary is found:
small radial mode distances can lead to strong nonlinear mode stabilization of
a linearly dominant mode.",1209.2549v1
2012-09-15,Dynamical tunneling-assisted coupling of high-Q deformed microcavities using a free-space beam,"We investigate the efficient free-space excitation of high-Q resonance modes
in deformed microcavities via dynamical tunneling-assisted coupling. A quantum
scattering theory is employed to study the free-space transmission properties,
and it is found that the transmission includes the contribution from (1) the
off-resonance background and (2) the on-resonance modulation, corresponding to
the absence and presence of high-Q modes, respectively. The theory predicts
asymmetric Fano-like resonances around high-Q modes in background transmission
spectra, which are in good agreement with our recent experimental results.
Dynamical tunneling across Kolmogorov-Arnold-Moser tori is further studied,
which plays an essential role in the Fano-like resonance. This efficient
free-space coupling holds potential advantages in simplifying experimental
condition and exciting high-Q modes in higher-index-material microcavities.",1209.3395v3
2012-09-20,Surface resistance measurements of HTS thin films using SLAO dielectric resonator,"Surface resistance of HTS films is typically measured using Sapphire
dielectric rod resonators enclosed in a copper cavity. In this paper we present
surface resistance measurements of YBa2Cu3O7-{\delta} films using Strontium
Lanthanum Aluminate (SLAO) at a resonant frequency of 18.2 GHz. We have
performed the error analysis of the cavity loaded with SLAO dielectric rod and
also verification measurements using two Sapphire (Al2O3) rod resonators
operating at resonant frequencies of 24.6 GHz and 10 GHz respectively. Good
agreement between the values of Rs of two sets of YBa2Cu3O7-{\delta} films
measured using the SLAO and the Sapphire dielectrics has been obtained after a
frequency scaling of Rs was applied. Using different dielectric rods of the
same size in the same cavity for measurements of Rs of HTS films, it is
feasible to do microwave characterization of the same films at differing
frequencies.",1209.4519v1
2012-09-24,"Chaos-assisted, broadband trapping of light in optical resonators","Chaos is a phenomenon that occurs in many aspects of contemporary science. In
classical dynamics, chaos is defined as a hypersensitivity to initial
conditions. The presence of chaos is often unwanted, as it introduces
unpredictability, which makes it difficult to predict or explain experimental
results. Conversely, we demonstrate here how chaos can be used to enhance the
ability of an optical resonator to store energy. We combine analytic theory
with ab-initio simulations and experiments in photonic crystal resonators to
show that a chaotic resonator can store six times more energy than its
classical counterpart of the same volume. We explain the observed increase with
the equipartition of energy among all degrees of freedom of the chaotic
resonator, i.e. the cavity modes, which is evident from the convergence of
their lifetime towards a single value. A compelling illustration of the theory
is provided by demonstrating enhanced absorption in deformed polystyrene
microspheres.",1209.5366v1
2012-10-04,THz spectroscopy in the pseudo-Kagome system Cu3Bi(SeO3)2O2Br,"Terahertz (THz) transmission spectra have been measured as function of
temperature and magnetic field on single crystals of Cu3Bi(SeO3)2O2Br. In the
time-domain THz spectra without magnetic field, two resonance absorptions are
observed below the magnetic ordering temperature T_N~27.4 K. The corresponding
resonance frequencies increase with decreasing temperature and reach energies
of 1.28 and 1.23 meV at 3.5 K. Multi-frequency electron spin resonance
transmission spectra as a function of applied magnetic field show the field
dependence of four magnetic resonance modes, which can be modeled as a
ferromagnetic resonance including demagnetization and anisotropy effects.",1210.1343v2
2012-10-06,Ab initio description of the exotic unbound 7He nucleus,"The neutron rich exotic unbound 7He nucleus has been the subject of many
experimental investigations. While the ground-state 3/2- resonance is well
established, there is a controversy concerning the excited 1/2- resonance
reported in some experiments as low-lying and narrow (E_R ~ 1 MeV, Gamma < 1
MeV) while in others as very broad and located at a higher energy. This issue
cannot be addressed by ab initio theoretical calculations based on traditional
bound-state methods. We introduce a new unified approach to nuclear bound and
continuum states based on the coupling of the no-core shell model, a
bound-state technique, with the no-core shell model/resonating group method, a
nuclear scattering technique. Our calculations describe the ground-state
resonance in agreement with experiment and, at the same time, predict a broad
1/2- resonance above 2 MeV.",1210.1897v1
2012-10-09,Resonances and bifurcations in systems with elliptical equipotentials,"We present a general analysis of the orbit structure of 2D potentials with
self-similar elliptical equipotentials by applying the method of Lie transform
normalization. We study the most relevant resonances and related bifurcations.
We find that the 1:1 resonance is associated only to the appearance of the
loops and leads to the destabilization of either one or the other normal modes,
depending on the ellipticity of equipotentials. Inclined orbits are never
present and may appear only when the equipotentials are heavily deformed. The
1:2 resonance determines the appearance of bananas and anti-banana orbits: the
first family is stable and always appears at a lower energy than the second,
which is unstable. The bifurcation sequence also produces the variations in the
stability character of the major axis orbit and is modified only by very large
deformations of the equipotentials. Higher-order resonances appear at
intermediate or higher energies and can be described with good accuracy.",1210.2753v1
2012-10-17,Überresonant Scattering of Ultracold Molecules,"Compared to purely atomic collisions, ultracold molecular collisions
potentially support a much larger number of Fano-Feshbach resonances due to the
enormous number of ro-vibrational states available. In fact, for alkali-metal
dimers we find that the resulting density of resonances cannot be resolved at
all, even on the sub-$\mu$K temperature scale of ultracold experiments. As a
result, all observables become averaged over many resonances and can
effectively be described by simpler, non-resonant scattering calculations. Two
particular examples are discussed: non-chemically reactive RbCs and chemically
reactive KRb. In the former case, the formation of a long-lived collision
complex may lead to the ejection of molecules from a trap. In the latter case,
chemical reactions broaden the resonances so much that they become
unobservable.",1210.4955v1
2012-10-25,Mode-mixing quantum gates and entanglement without particle creation in periodically accelerated cavities,"We show that mode-mixing quantum gates can be produced by non-uniform
relativistic acceleration. Periodic motion in cavities exhibits a series of
resonant conditions producing entangling quantum gates between different
frequency modes. The resonant condition associated with particle creation is
the main feature of the dynamical Casimir effect which has been recently
demonstrated in superconducting circuits. We show that a second resonance,
which has attracted less attention since it implies negligible particle
production, produces a beam splitting quantum gate leading to a resonant
enhancement of entanglement which can be used as the first evidence of
acceleration effects in mechanical oscillators. We propose a desktop experiment
where the frequencies associated with this second resonance can be produced
mechanically.",1210.6772v2
2012-10-28,Objects orbiting the Earth in deep resonance,"The increasing number of objects orbiting the Earth justifies the great
attention and interest in the observation, spacecraft protection and collision
avoidance. These studies involve different disturbances and resonances in the
orbital motions of these objects distributed by the distinct altitudes. In this
work, the TLE (Two-Line Elements) of the NORAD are studied observing the
resonant period of the objects orbiting the Earth and the main resonance in the
LEO region. The time behavior of the semi-major axis, eccentricity and
inclination of some space debris are studied. Possible irregular motions are
observed by the frequency analysis and by the presence of different resonant
angles describing the orbital dynamics of these objects.",1210.7479v2
2012-10-30,Surpassing fundamental limits of oscillators using nonlinear resonators,"Self-sustained oscillators are ubiquitous and essential for metrology,
communications, time reference, and geolocation. In its most basic form an
oscillator consists of a resonator driven on-resonance, through feedback, to
create a periodic signal sustained by a static energy source. The generation of
a stable frequency, the basic function of oscillators, is typically achieved by
increasing the amplitude of motion of the resonator while remaining within its
linear, harmonic, regime. Contrary to this conventional paradigm, in this
Letter we show that by operating the oscillator at special points in the
resonators anharmonic regime we can overcome fundamental limitations of
oscillator performance due to thermodynamic noise as well as practical
limitations due to noise from the sustaining circuit. We develop a
comprehensive model that accounts for the major contributions to the phase
noise of the nonlinear oscillator. Using a nanoelectromechanical system
(NEMS)-based oscillator, we experimentally verify the existence of a special
region in the operational parameter space that enables a significant reduction
of the oscillators phase noise, as predicted by our model.",1210.8075v1
2012-12-09,Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV,"A search has been made for massive resonances decaying into a quark and a
vector boson, qW or qZ, or a pair of vector bosons, WW, WZ, or ZZ, where each
vector boson decays to hadronic final states. This search is based on a data
sample corresponding to an integrated luminosity of 5.0 inverse femtobarns of
proton-proton collisions collected in the CMS experiment at the LHC in 2011 at
a center-of-mass energy of 7 TeV. For sufficiently heavy resonances the decay
products of each vector boson are merged into a single jet, and the event
effectively has a dijet topology. The background from QCD dijet events is
reduced using recently developed techniques that resolve jet substructure. A
95% CL lower limit is set on the mass of excited quark resonances decaying into
qW (qZ) at 2.38 TeV (2.15 TeV) and upper limits on the cross section for
resonances decaying to qW, qZ, WW, WZ, or ZZ final states.",1212.1910v2
2012-12-12,Feshbach Resonance in a Synthetic Non-Abelian Gauge Field,"We study the Feshbach resonance of spin-1/2 particles in the presence of a
uniform synthetic non-Abelian gauge field that produces spin orbit coupling
along with constant spin potentials. We develop a renormalizable quantum field
theory that includes the closed channel boson which engenders the Feshbach
resonance, in the presence of the gauge field. By a study of the scattering of
two particles in the presence of the gauge field, we show that the Feshbach
magnetic field, where the apparent low energy scattering length diverges,
depends on the conserved centre of mass momentum of the two particles. For high
symmetry gauge fields, such as the one which produces an isotropic Rashba spin
orbit coupling, we show that the system supports two bound states over a regime
of magnetic fields for a negative background scattering length and resonance
width comparable to the energy scale of the spin orbit coupling. We discuss the
consequences of these findings for the many body setting, and point out that a
broad resonance (width larger than spin orbit coupling energy scale) is most
favourable for the realization of the rashbon condensate.",1212.2858v1
2012-12-12,Repulsively induced photon super-bunching in driven resonator arrays,"We analyze the non-equilibrium behaviour of driven nonlinear photonic
resonator arrays under the selective excitation of specific photonic many-body
modes. Targeting the unit-filled ground state, we find a counter-intuitive
`super bunching' in the emitted photon statistics in spite of relatively strong
onsite repulsive interaction. We consider resonator arrays with Kerr
nonlinearities described by the Bose Hubbard model, but also show that an
analogous effect is observable in near-future experiments coupling resonators
to two-level systems as described by the Jaynes Cummings Hubbard Hamiltonian.
For the experimentally accessible case of a pair of coupled resonators forming
a photonic molecule, we provide an analytical explanation for the nature of the
effect.",1212.3012v1
2012-12-16,Coherent Population Trapping resonances on lower atomic levels of Doppler broadened optical lines,"We have detected and analysed narrow high-contrast coherent population
trapping (CPT) resonances, which are induced in absorption of the weak probe
light beam by the counterpropagating two-frequency pumping radiation. Our
experimental investigations have been carried out on example of nonclosed three
level Lambda systems formed by spectral components of the Doppler broadened D2
line of cesium atoms. We have established that CPT resonances in transmission
of the probe beam (in the cesium vapor), at definite conditions, may have not
only more contrast but also much lesser width in comparison with well- known
CPT resonances in transmission of the corresponding two-frequency pumping
radiation. Thus CPT resonances, detected by the elaborated method, may be used
in atomic frequency standards and sensitive magnetometers (based on the CPT
phenomenon) and also in ultahigh resolution spectroscopy of atoms and
molecules.",1212.3834v1
2012-12-23,Sidebands in Optically Detected Magnetic Resonance Signals of Nitrogen Vacancy Centers in Diamond,"We study features in the optically detected magnetic resonance (ODMR) signals
associated with negatively charged nitrogen-vacancy (NV) centers coupled to
other paramagnetic impurities in diamond. Our results are important for
understanding ODMR line shapes and for optimization of devices based on NV
centers. We determine the origins of several side features to the unperturbed
NV magnetic resonance by studying their magnetic field and microwave power
dependences. Side resonances separated by around 130 MHz are due to hyperfine
coupling between NV centers and nearest-neighbor C-13 nuclear spins. Side
resonances separated by approximately {40, 260, 300} MHz are found to originate
from simultaneous spin flipping of NV centers and single substitutional
nitrogen atoms. All results are in agreement with the presented theoretical
calculations.",1212.5746v3
2012-12-29,Resonant switch model of twin peak HF QPOs applied to the atoll source 4U 1636-53,"We present a Resonant Switch (RS) model of twin peak high-frequency
quasi-periodic oscillations (HF QPOs), assuming switch of twin oscillations at
a resonant point, where frequencies of the upper and lower oscillations $\nu_U$
and $\nu_L$ become to be commensurable and the twin oscillations change from
one pair of the oscillating modes (corresponding to a specific model of HF
QPOs) to some other pair due to non-linear resonant phenomena. The RS model
enables to determine range of allowed values of spin $a$ and mass $M$ of the
neutron star located at the atoll source 4U 1636-53 where two resonant points
are observed at frequency ratios $\nu_U:\nu_L$ = 3:2, 5:4.",1212.6669v1
2013-01-02,How to test for mass degenerate Higgs resonances,"The Higgs-like signal observed at the LHC could be due to several mass
degenerate resonances. We show that the number of resonances is related to the
rank of a ""production and decay"" matrix, $R_{if}$. Each entry in this matrix
contains the observed rate in a particular production mode $i$ and final state
$f$. In the case of $N$ non-interfering resonances, the rank of $R$ is, at
most, $N$. If interference plays a role, the maximum rank is $N^2$ or in the CP
limit $N(N+1)/2$. As an illustration we use the present experimental data to
constrain the rank of the corresponding matrix. We estimate the LHC reach of
probing two and three resonances under various speculations on future
measurements and uncertainties.",1301.0328v2
2013-01-08,Hadronic resonance production in Pb-Pb collisions at the ALICE experiment,"Measurements of the yields of hadronic resonances (relative to
non-resonances) in high-energy heavy-ion collisions allow the chemical
freeze-out temperature and the time between chemical and thermal freeze-out of
the collision system to be studied, while modifications to resonance masses and
widths could be a signature of chiral symmetry restoration. The spectra (for pT
< 5 GeV/c), total integrated yields, ratios to non-resonances (phi/pi and
phi/K), mass, and width of the phi(1020) meson and the uncorrected yields,
mass, and width of the K*(892)0 and anti-K*(892)0 mesons have been measured
using the ALICE detector for Pb-Pb collisions at 2.76 TeV. These measurements
will be compared to results from other collision systems and energies. Angular
correlations between leading trigger hadrons and phi(1020) mesons have been
measured in Pb-Pb and pp collisions; the mass and width of the phi(1020) meson
as a function of the correlation angle will be presented.",1301.1644v1
2013-01-10,Multipair DC-Josephson Resonances in a biased all-superconducting Bijunction,"An all-superconducting bijunction consists of a central superconductor
contacted to two lateral superconductors, such that non-local crossed Andreev
reflection is operating. Then new correlated transport channels for the Cooper
pairs appear in addition to those of separated conventional Joseph- son
junctions. We study this system in a configuration where the superconductors
are connected through gate-controllable quantum dots. Multipair phase-coherent
resonances and phase-dependent multiple Andreev reflections are both obtained
when the voltages of the lateral superconductors are commensurate, and they add
to the usual local dissipative transport due to quasiparticles. The two-pair
resonance (quartets) as well as some other higher order multipair resonances
are {\pi}-shifted at low voltage. Dot control can be used to dramatically
enhance the multipair current when the voltages are resonant with the dot
levels.",1301.2344v2
2013-01-16,Quantum Photovoltaic Effect in Double Quantum Dots,"We analyze the photovoltaic current through a double quantum dot system
coupled to a high-quality driven microwave resonator. The conversion of photons
in the resonator to electronic excitations produces a current flow even at zero
bias across the leads of the double quantum dot system. We demonstrate that due
to the quantum nature of the electromagnetic field in the resonator, the
photovoltaic current exhibits a double peak dependence on the frequency
$\omega$ of an external microwave source. The distance between the peaks is
determined by the strength of interaction between photons in the resonator and
electrons in the double quantum dot. The double peak structure disappears as
strengths of relaxation processes increases, recovering a simple classical
condition for maximal current when the microwave frequency is equal to the
resonator frequency.",1301.3788v1
2013-01-17,Brief Report on the Extended Linear Sigma Model,"We present a chiral effective model which exhibits all the known symmetry
features of the QCD Lagrangian. The extended Linear Sigma Model (eLSM) includes
(pseudo-)scalar and (axial-) vector mesons, glueballs, and baryons. It has
proven to be a useful tool to understand the nature of the low-energy
resonances. It can be used to describe the masses and decay widths of the known
low-energy mesons and to disentangle the complicated picture of resonances in
the low-energy range. We can answer some of the open questions in the
low-energy region, e.g. the resonance (f_0(1500)) is a predominantly glueball
state and the resonance (f_0(1370)) is most likely the chiral partner of the
pion. We could also find that the resonance (N(1650)) is favoured as the chiral
partner of the nucleon (N(939)). In addition the temperature dependence of the
chiral condensate and the glueball condensate can be used to study the phase
diagram at nonzero temperatures and densities. At nonzero density we achieve
nuclear matter saturation.",1301.4035v1
2013-01-30,Feedback spectroscopy of atomic resonances,"We propose a non-standard spectroscopic technique that uses a feedback
control of the input probe field parameters to significantly increase the
contrast and quality factor of the atomic resonances. In particular, to apply
this technique for the dark resonances we sustain the fluorescence intensity at
a fixed constant level while taking the spectra process. Our method, unlike the
conventional spectroscopy, does not require an optically dense medium.
Theoretical analysis has been experimentally confirmed in spectroscopy of
atomic rubidium vapor in which a considerable increase (one-two order) of the
resonance amplitude and a 3-fold decrease of the width have been observed in
optically thin medium. As a result, the quality factor of the dark resonance is
increased by two orders of magnitude and its contrast reaches a record level of
260%. Different schemes, including magneto-optical Hanle spectroscopy and
Doppler-free spectroscopy have also showed a performance enhancement by using
the proposed technique.",1301.7305v2
2013-02-03,Search for pair-produced dijet resonances in four-jet final states in pp collisions at sqrt(s) = 7 TeV,"A search for the pair production of a heavy, narrow resonance decaying into
two jets has been performed using events collected in sqrt(s) = 7 TeV pp
collisions with the CMS detector at the LHC. The data sample corresponds to an
integrated luminosity of 5.0 inverse femtobarns. Events are selected with at
least four jets and two dijet combinations with similar dijet mass. No
resonances are found in the dijet mass spectrum. The upper limit at 95%
confidence level on the product of the resonance pair production cross section,
the branching fractions into dijets, and the acceptance varies from 0.22 to
0.005 pb, for resonance masses between 250 and 1200 GeV. Pair-produced colorons
decaying into q q' are excluded for coloron masses between 250 and 740 GeV.",1302.0531v2
2013-02-19,Orbital Resonance Mode in Superconducting Iron Pnictides,"We show that the fluctuations associated with ferro orbital order in the
$d_{xz}$ and $d_{yz}$ orbitals can develop a sharp resonance mode in the
superconducting state with a nodeless gap on the Fermi surface. This orbital
resonance mode appears below the particle-hole continuum and is analogous to
the magnetic resonance mode found in various unconventional superconductors. If
the pairing symmetry is $s_{\pm}$, a dynamical coupling between the orbital
ordering and the d-wave subdominant pairing channels is present by symmetry.
Therefore the nature of the resonance mode depends on the relative strengths of
the fluctuations in these two channels, which could vary significantly for
different families of the iron based superconductors. The application of our
theory to a recent observation of a new $\delta$-function-like peak in the
B$_{1g}$ Raman spectrum of Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ is discussed.",1302.4749v2
2013-02-28,First-principles calculations of spin and angle-resolved resonant photoemission spectra of Cr(110) surfaces at the 2$p$ - 3$d$ resonance,"A first principles approach for spin and angle resolved resonant
photoemission is developed within multiple scattering theory and applied to a
Cr(110) surface at the 2$p$-3$d$ resonance. The resonant photocurrent from this
non ferromagnetic system is found to be strongly spin polarized by circularly
polarized light, in agreement with experiments on antiferromagnetic and
magnetically disordered systems. By comparing the antiferromagnetic and
Pauli-paramagnetic phases of Cr, we explicitly show that the spin polarization
of the photocurrent is independent of the existence of local magnetic moments,
solving a long-standing debate on the origin of such polarization. New spin
polarization effects are predicted for the paramagnetic phase even with
unpolarized light, opening new directions for full mapping of spin interactions
in macroscopically non magnetic or nanostructured systems.",1302.7160v1
2013-03-02,Observation of Feshbach resonances between ultracold Na and Rb atoms,"We have successfully prepared an optically trapped ultracold mixture of
$^{23}$Na and $^{87}$Rb atoms and studied their interspecies Feshbach
resonances. Using two different spin combinations, several s-wave and p-wave
resonances are identified by observing a high inelastic loss and a temperature
rising for both species near resonant magnetic field values. The two s-wave
resonances observed below 500 G between atoms in the lowest energy level are
possible candidates for Feshbach molecule association. Our results are well
characterized by a coupled-channel model and are used refining the ground state
interaction potentials between $^{23}$Na and $^{87}$Rb. This work opens up the
prospect for preparing ultracold ensembles of ground-state bosonic NaRb
molecules which are chemically stable and can provide strong dipolar
interactions.",1303.0334v2
2013-03-04,Exact conservation and breaking of pseudospin symmetry in single particle resonant states,"In this contribution we present some results on the study of pseudospin
symmetry (PSS) in single particle resonant states. The PSS is a relativistic
dynamical symmetry connected with the small component of the nucleon Dirac wave
function. Many efforts have been made to study this symmetry in bound states.
We recently gave a rigorous justification of the PSS in single particle
resonant states by examining the zeros of Jost functions corresponding to the
small components of the radial Dirac wave functions and phase shifts of
continuum states [1, Phys. Rev. Lett. 109 (2012) 072501]. We have shown that
the PSS in single particle resonant states in nuclei is conserved when the
attractive scalar and repulsive vector potentials have the same magnitude but
opposite sign. Examples of exact conservation and breaking of this symmetry in
single particle resonances are given for spherical square-well and Woods-Saxon
potentials.",1303.0630v1
2013-03-08,Controlling single-photon transport in waveguides with finite cross-section,"We study the transverse-size effect of a quasi-one-dimensional rectangular
waveguide on the single-photon scattering on a two-level system. We calculate
the transmission and reflection coefficients for single incident photons using
the scattering formalism based on the Lippmann-Schwinger equation. When the
transverse size of the waveguide is larger than a critical size, we find that
the transverse mode will be involved in the single-photon scattering. Including
the coupling to a higher traverse mode, we find that the photon in the lowest
channel will be lost into the other channel, corresponding to the other
transverse modes, when the input energy is larger than the maximum bound-state
energy. Three kinds of resonance phenomena are predicted: single-photon
resonance, photonic Feshbach resonance, and cutoff (minimum) frequency
resonance. At these resonances, the input photon is completely reflected.",1303.1981v2
2013-03-15,Temperature effects on the surface plasmon resonance in copper nanoparticles,"The temperature dependences of the energy and the width of a surface plasmon
resonance are studied for copper nanoparticles 17 - 59 nm in size in the silica
host matrix in the temperature interval 293 - 460 K. An increase of the
temperature leads to the red shift and the broadening of the surface plasmon
resonance in Cu nanoparticles. The obtained dependences are analyzed within the
framework of a theoretical model considering the thermal expansion of a
nanoparticle, the electron-phonon scattering in a nanoparticle, and the
temperature dependence of the dielectric permittivity of the host matrix. The
thermal expansion is shown to be the main mechanism responsible for the
temperature-induced red shift of the surface plasmon resonance in copper
nanoparticles. The thermal volume expansion coefficient for Cu nanoparticles is
found to be size-independent in the studied size range. Meanwhile, the increase
of the electron-phonon scattering rate with the temperature is shown to be the
dominant mechanism of the surface plasmon resonance broadening in copper
nanoparticles.",1303.3778v1
2013-03-15,Universality of the three-body Efimov parameter at narrow Feshbach resonances,"We measure the critical scattering length for the appearance of the first
three-body bound state, or Efimov three-body parameter, at seven different
Feshbach resonances in ultracold 39K atoms. We study both intermediate and
narrow resonances, where the three-body spectrum is expected to be determined
by the non-universal coupling of two scattering channels. We observe instead
approximately the same universal relation of the three-body parameter with the
two-body van der Waals radius already found for broader resonances, which can
be modeled with a single channel. This unexpected observation suggests the
presence of a new regime for three-body scattering at narrow resonances.",1303.3843v1
2013-03-21,Resonance phenomena in the interaction of a many-photon wave packet and a qubit,"We demonstrate that a highly excited quantum electromagnetic mode strongly
interacting with a single qubit exhibits several distinct resonances in
addition to the Bloch-Siegert resonance condition that arises in the
interaction with classical radiation. The resonance phenomena are associated
with non-classical effects: Collapse of Rabi oscillations, splitting of the
photon wave packet, and field-qubit entanglement. The analysis is based on a
semiclassical phase-space flow of 2-by-2 matrices and becomes exact when the
photon number tends to infinity. The flow equations are solved perturbatively
and numerically, showing that the resonant detuning of the field and qubit
frequencies lie on two branches in the leading order, that further split into
distinct curves in higher orders.",1303.5256v1
2013-03-25,Optical control of individual carbon nanotube light emitters by spectral double resonance in silicon microdisk resonators,"Single-walled carbon nanotubes have advantages as a nanoscale light source
compatible with silicon photonics because they show room-temperature
luminescence at telecom-wavelengths and can be directly synthesized on silicon
substrates. Here we demonstrate integration of individual light-emitting carbon
nanotubes with silicon microdisk resonators. Photons emitted from nanotubes are
efficiently coupled to whispering gallery modes, circulating within the disks
and lighting up their perimeters. Furthermore, we control such emission by
tuning the excitation wavelength in and out of resonance with higher order
modes in the same disk. Our results open up the possibilities of using nanotube
emitters embedded in photonic circuits that are individually addressable
through spectral double resonance.",1303.6035v1
2013-03-25,High quality factor mg-scale silicon mechanical resonators for 3-mode optoacoustic parametric amplifiers,"Milligram-scale resonators have been shown to be suitable for the creation of
3-mode optoacoustic parametric amplifiers, based on a phenomena first predicted
for advanced gravitational-wave detectors. To achieve practical optoacoustic
parametric amplification, high quality factor resonators are required. We
present millimetre-scale silicon resonators designed to exhibit a torsional
vibration mode with a frequency in the 10^5 - 10^6 Hz range, for observation of
3-mode optoacoustic interactions in a compact table-top system. Our design
incorporates an isolation stage and minimizes the acoustic loss from optical
coating. We observe a quality factor of 7.5 x 10^5 for a mode frequency of
401.5 kHz, at room temperature and pressure of 10^-3 Pa. We confirmed the mode
shape by mapping the amplitude response across the resonator and comparing to
finite element modelling. This study contributes towards the development of
3-mode optoacoustic parametric amplifiers for use in novel high-sensitivity
signal transducers and quantum measurement experiments.",1303.6595v1
2013-03-28,Electronic Band Structure of Wurtzite GaP Nanowires via Resonance Raman Spectroscopy,"Raman measurements are performed on defect-free wurzite GaP nanowires.
Resonance Raman measurements are carried out over the excitation energy range
between 2.19 and 2.71 eV. Resonances at 2.38 eV and 2.67 eV of the E1(LO) mode
and at 2.67 eV of the A1(LO) are observed. The presence of these intensity
resonances clearly demonstrates the existence of energy states with Gamma_9hh
and Gamma_7V (Gamma_7C) symmetries of the valence (conduction) band and allows
to measure WZ phase GaP band energies at the Gamma point. In addition, we have
investigated temperature dependent resonant Raman measurements, which allowed
us to extrapolate the zero temperature values of Gamma point energies, along
with the crystal field and spin-orbit splitting energies. Above results provide
a feedback for refining available theoretical calculations to derive the
correct wurtzite III-V semiconductor band structure.",1303.7058v1
2013-04-04,Teraherz photomixing using plasma resonances in double-graphene layer structures,"We propose the concept of terahertz (THz) photomixing enabled by the
interband electron transitions due to the absorption of modulated optical
radiation in double-graphene layer (double-GL) structures and the resonant
excitation of plasma oscillations. Using the developed double-GL photomixer
(DG-PM) model, we describe its operation and calculate the device
characteristics. The output power of the THz radiation exhibits sharp resonant
peaks at the plasmonic resonant frequencies. The peak powers markedly exceed
the output powers at relatively low frequencies. Due to relatively high quantum
efficiency of optical absorption in GLs and short inter-GL transit time, the
proposed DG-PM operating in the resonant plasma oscillation regime can surpass
the photomixers based on the standard heterostructures .",1304.1260v2
2013-04-09,Quartz Tuning Forks and Acoustic Phenomena - Application to Superfluid Helium,"Immersed mechanical resonators are well suited for probing the properties of
fluids, since the surrounding environment influences the resonant
characteristics of such oscillators in several ways. Quartz tuning forks have
gained much popularity in recent years as the resonators of choice for studies
of liquid helium. They have many superior properties when compared to other
oscillating bodies conventionally used for this purpose, such as vibrating
wires. However, the intricate geometry of a tuning fork represents a challenge
for analyzing their behavior in a fluid environment - analytical approaches do
not carry very far. In this article the characteristics of immersed quartz
tuning fork resonators are studied by numerical simulations. We account for the
compressibility of the medium, that is acoustic phenomena, and neglect
viscosity, with the aim to realisticallymodel the oscillator response in
superfluid helium. The significance of different tuning fork shapes is studied.
Acoustic emission in infinite medium and acoustic resonances in confined
volumes are investigated. The results can aid in choosing a quartz tuning fork
with suitable properties for experiments, as well as interpreting measured
data.",1304.2795v3
2013-04-11,X-ray photon detection using superconducting resonators in thermal quasi-equilibrium,"Superconducting resonators have to date been used for photon detection in a
non-equilibrium manner. In this paper, we demonstrate that such devices can
also be used in a thermal quasi-equilibrium manner to detect X-ray photons. We
have used a resonator to measure the temperature rise induced by an X-ray
photon absorbed in normal metal and superconducting absorbers on continuous and
perforated silicon nitride membranes. We observed two distinct pulses with
vastly different decay times. We attribute the shorter pulses to
non-equilibrium quasiparticle relaxation and the longer pulses to a thermal
relaxation process. In addition, we have measured the temperature dependence of
the X-ray induced temperature rise and decay times. Finally, we have measured
the resonator sensitivity and energy resolution. Superconducting resonators
used in a thermal quasi-equilibrium manner have the potential to be used for
X-ray microcalorimetry.",1304.3387v2
2013-04-12,"Bifurcation, mode coupling and noise in a nonlinear multimode superconducting RF resonator","The addition of nonlinearity to an harmonic resonator provides a route to
complex dynamical behaviour of resonant modes, including coupling between them.
We present a superconducting device that makes use of the nonlinearity of
Josephson junctions to introduce a controlled, tunable, nonlinear inductance to
a thin film coplanar waveguide resonator. Considering the device as a potential
quantum optical component in the microwave regime, we create a sensitive
bifurcation amplifier and then demonstrate spectroscopy of other resonant modes
via the intermode coupling. We find that the sensitivity of the device
approaches within a factor two quantitative agreement with a quantum model by
Dykman, but is limited by a noise that has its source(s) on-chip.",1304.3693v2
2013-04-25,Hidden Sector Photon Coupling of Resonant Cavities,"Many beyond the standard model theories introduce light paraphotons, a
hypothetical spin-1 field that kinetically mixes with photons. Microwave cavity
experiments have traditionally searched for paraphotons via transmission of
power from an actively driven cavity to a passive receiver cavity, with the two
cavities separated by a barrier that is impenetrable to photons. We extend this
measurement technique to account for two-way coupling between the cavities and
show that the presence of a paraphoton field can alter the resonant frequencies
of the coupled cavity pair. We propose an experiment that exploits this effect
and uses measurements of a cavities resonant frequency to constrain the
paraphoton-photon mixing parameter, chi. We show that such an experiment can
improve sensitivity to chi over existing experiments for paraphoton masses less
than the resonant frequency of the cavity, and eliminate some of the most
common systematics for resonant cavity experiments.",1304.6866v1
2013-04-26,Non-equilibrium correlations and entanglement in a semiconductor hybrid circuit-QED system,"We present a theoretical study of a hybrid circuit-QED system composed of two
semiconducting charge-qubits confined in a microwave resonator. The qubits are
defined in terms of the charge states of two spatially separated double quantum
dots (DQDs) which are coupled to the same photon mode in the microwave
resonator. We analyze a transport setup where each DQD is attached to
electronic reservoirs and biased out-of-equilibrium by a large voltage, and
study how electron transport across each DQD is modified by the coupling to the
common resonator. In particular, we show that the inelastic current through
each DQD reflects an indirect qubit-qubit interaction mediated by off-resonant
photons in the microwave resonator. As a result of this interaction, both
charge qubits stay entangled in the steady (dissipative) state. Finite shot
noise cross-correlations between currents across distant DQDs are another
manifestation of this nontrivial steady-state entanglement.",1304.7192v2
2013-04-29,The prospects of forming ultracold molecules in $^2Σ$ states by magnetoassociation of alkali-metal atoms with Yb,"We explore the feasibility of producing ultracold diatomic molecules with
nonzero electric and magnetic dipole moments by magnetically associating two
atoms, one with zero electron spin and one with nonzero spin. Feshbach
resonances arise through the dependence of the hyperfine coupling on
internuclear distance. We survey the Feshbach resonances in diatomic systems
combining the nine stable alkali-metal isotopes with those of Yb, focussing on
the illustrative examples of RbYb and CsYb. We show that the resonance widths
may expressed as a product of physically comprehensible terms in the framework
of Fermi's Golden Rule. The resonance widths depend strongly on the background
scattering length, which may be adjusted by selecting the Yb isotope, and on
the hyperfine coupling constant and the magnetic field. In favorable cases the
resonances may be over 100 mG wide.",1304.7674v1
2013-04-30,Retrograde resonance in the planar three-body problem,"We continue the investigation of the dynamics of retrograde resonances
initiated in Morais & Giuppone (2012). After deriving a procedure to deduce the
retrograde resonance terms from the standard expansion of the three-dimensional
disturbing function, we concentrate on the planar problem and construct
surfaces of section that explore phase-space in the vicinity of the main
retrograde resonances (2/-1, 1/-1 and 1/-2). In the case of the 1/-1 resonance
for which the standard expansion is not adequate to describe the dynamics, we
develop a semi-analytic model based on numerical averaging of the unexpanded
disturbing function, and show that the predicted libration modes are in
agreement with the behavior seen in the surfaces of section.",1305.0016v2
2013-05-01,Resonant peak splitting for graphene superlattices with one-dimensional periodic potentials of square barriers,"We have investigated theoretically the resonance splitting effect of Dirac
electrons through graphene superlattices with periodic potentials of square
barriers. It is found that each resonance peak in the transmission gap presents
(N-1)-fold resonance splitting for N-barriers, which is the analogy of the case
in semiconductor superlattices. The resonance splitting effect depends on the
incidence angle rather than the height and width of potential. However, there
is no explicit splitting rule for the conductance and shot noise, which is
different from the magnetic case. These properties may lead to potential
applications in graphene-based electron devices.",1305.0094v2
2013-05-01,Search for resonant diboson production in the lvjj decay channels with the ATLAS detector at 7 TeV,"A search for resonant diboson production using a data sample corresponding to
4.7 fb-1 of integrated luminosity collected by the ATLAS experiment at the
Large Hadron Collider in pp collisions at 7 TeV is presented. The search for a
narrow resonance in the WW or WZ mass distribution is conducted in a final
state with an electron or a muon, missing transverse momentum and at least two
jets. No significant excess is observed and limits are set using three
benchmark models: WW resonance masses below 940 GeV and 710 GeV are excluded at
95% confidence level for spin-2 Randall-Sundrum and bulk Randall-Sundrum
gravitons, respectively; WZ resonance masses below 950 GeV are excluded at 95%
confidence level for a spin-1 Extended Gauge Model W' boson.",1305.0125v1
2013-05-01,Driving a mechanical resonator in to coherent states via random measurements,"We propose dynamical schemes to engineer coherent states of a mechanical
resonator coupled to an ancillary, superconducting flux qubit. The flux qubit,
when repeatedly projected on to its ground state drives the mechanical
resonator in to a coherent state in probabilistic, albeit heralded fashion.
Assuming no operations on the state of the mechanical resonator during the
protocol, coherent states are successfully generated only up to a certain value
of the displacement parameter. This restriction can be overcome at the cost of
a one-time operation on the initial state of the mechanical resonator. We
discuss the possibility of experimental realization of the presented schemes.",1305.0290v2
2013-05-05,Detection and size measurement of individual hemozoin nanocrystals in aquatic environment using a whispering gallery mode resonator,"We, for the first time, report the detection and the size measurement of
single nanoparticles (i.e. polystyrene) in aquatic environment using mode
splitting in a whispering gallery mode (WGM) optical resonator, namely a
microtoroid resonator. Using this method we achieved detecting and measuring
individual synthetic hemozoin nanocrystals, which are a hemoglobin degradation
by-product of malarial parasites, dispersed in a solution or in air. The
results of size measurement in solution and in air agree with each other and
with those obtained using scanning electron microscope and dynamic light
scattering. Moreover, we compare the sensing capabilities of the degenerate
(single resonance) and non-degenerate (split mode, doublet) operation regimes
of the WGM resonator.",1305.0988v1
2013-05-11,Demonstration of Motion Transduction Based on Parametrically Coupled Mechanical Resonators,"Universal sensing the motion of mechanical resonators with high precision and
low back-action is of paramount importance in ultra-weak signal detection which
plays a fundamental role in modern physics. Here we present a universal scheme
that transfer mechanically the motion of the resonator not directly measurable
to the one can be precisely measured using mechanical frequency conversion.
Demonstration of the scheme at room temperature shows that both the motion
imprecision and the back-action force are below the intrinsic level of the
objective resonator, which agree well with our theoretical prediction. The
scheme developed here provides an effective interface between an arbitrary
mechanical resonator and a high quantum efficient displacement sensor, and is
expected to find extensive applications in high-demanding mechanical-based
force measurements.",1305.2457v1
2013-05-16,Saturnian mean motion resonances in meteoroid streams,"Many previous works have shown the relevance and dynamics of Jovian mean
motion resonances (MMR) in various meteoroid streams. These resonant swarms are
known to have produced spectacular meteor displays in the past. In this work we
investigate whether any MMR due to Saturn are feasible, and subsequently check
whether such effects are strong enough to trap meteoroids so as to cause
enhanced meteor phenomena on Earth. Extensive numerical simulations are done on
two major meteoroid streams, which are known to exhibit exterior Jovian
resonances. The roles of the 1:6 and 5:14 Jovian MMR have already been studied
in the Orionids and Leonids respectively. Now we find strong evidence of 1:3
and 8:9 Saturnian MMR in Orionids and Leonids respectively. The presence of
compact dust trails in real space due to these two Saturnian resonances is
confirmed from our calculations.",1305.3860v1
2013-05-28,Shape evolution of giant resonances in Nd and Sm isotopes,"Giant multipole resonances in Nd and Sm isotopes are studied by employing the
quasiparticle-random-phase approximation on the basis of the Skyrme
energy-density-functional method. Deformation effects on giant resonances are
investigated in these isotopes which manifest a typical nuclear shape change
from spherical to prolate shapes. The peak energy, the broadening, and the
deformation splitting of the isoscalar giant monopole (ISGMR) and quadrupole
(ISGQR) resonances agree well with measurements. The magnitude of the peak
splitting and the fraction of the energy-weighted strength in the lower peak of
the ISGMR reflect the nuclear deformation. The experimental data on ISGMR,
ISGDR, and ISGQR are consistent with the nuclear-matter incompressibility $K
\simeq 210-230$ MeV and the effective mass $m^*_0/m \simeq 0.8-0.9$. However,
the high-energy octupole resonance (HEOR) in $^{144}$Sm seems to indicates a
smaller effective mass, $m^*_0/m \simeq 0.7-0.8$. A further precise measurement
of HEOR is desired to determine the effective mass.",1305.6437v1
2013-06-02,Spin relaxation mechanism in graphene: resonant scattering by magnetic impurities,"It is proposed that the observed small (100 ps) spin relaxation time in
graphene is due to resonant scattering by local magnetic moments. At
resonances, magnetic moments behave as spin hot spots: the spin-flip scattering
rates are as large as the spin-conserving ones, as long as the exchange
interaction is greater than the resonance width. Smearing of the resonance
peaks by the presence of electron-hole puddles gives quantitative agreement
with experiment, for about 1 ppm of local moments. While the local moments can
come from a variety of sources, we specifically focus on hydrogen adatoms. We
perform first-principles supercell calculations and introduce an effective
Hamiltonian to obtain realistic input parameters for our mechanism.",1306.0230v1
2013-06-18,The confinement induced resonance in spin-orbit coupled cold atoms with Raman coupling,"We investigate the confinement induced resonance in spin-orbit coupled cold
atoms with Raman coupling. We find that the quasi-bound levels induced by the
spin-orbit coupling and Raman coupling result in the Feshbach-type resonances.
For sufficiently large Raman coupling, the bound states in one dimension exist
only for sufficiently strong attractive interaction. Furthermore, the bound
states in quasi-one dimension exist only for sufficient large ratio of the
length scale of confinement to three dimensional s-wave scattering length. The
Raman coupling substantially changes the confinement-induced resonance
position. We give a proposal to realize confinement induced resonance by
increasing the Raman coupling strength in experiments.",1306.4099v5
2013-06-18,Magnetic Dynamics of a Multiferroic with an Antiferromagnetic Layer,"Shape effects in magnetic particles are widely studied, because of the
ability of the shape and the size to control the parameters of a sample during
its production. Experiments with nano-sized samples show that the shape can
affect also the properties of antiferromagnetic (AFM) materials. However, the
theoretical interpretation of these effects is under discussion. We propose a
model to study the shape-induced effects in AFM particles at the AFM resonance
frequency. The Lagrange function method is used to calculate the spectrum of
resonance oscillations of the AFM vector in a synthetic multiferroic
(piezoelectric + antiferromagnet). The influence of the specimen shape on the
AFM resonance frequency in the presence of an external magnetic field is
studied. Conditions for a resonance under the action of an external force or
for a parametric resonance to arise in the magnetic subsystem are considered.",1306.4300v1
2013-06-20,Evidence of a nonequilibrium distribution of quasiparticles in the microwave response of a superconducting aluminium resonator,"In a superconductor absorption of photons with an energy below the
superconducting gap leads to redistribution of quasiparticles over energy and
thus induces a strong non-equilibrium quasiparticle energy distribution. We
have measured the electrodynamic response, quality factor and resonant
frequency, of a superconducting aluminium microwave resonator as a function of
microwave power and temperature. Below 200 mK, both the quality factor and
resonant frequency decrease with increasing microwave power, consistent with
the creation of excess quasiparticles due to microwave absorption.
Counterintuitively, above 200 mK, the quality factor and resonant frequency
increase with increasing power. We demonstrate that the effect can only be
understood by a non-thermal quasiparticle distribution.",1306.4992v2
2013-07-16,NNLO non-resonant corrections to threshold top-pair production from e+ e- collisions: Endpoint-singular terms,"We analyse the subleading non-resonant contributions to the e+ e- -> W+ W- b
bbar cross section at energies near the top-antitop threshold. These correspond
to next-to-next-to-leading-order (NNLO) corrections with respect to the
leading-order resonant result. We show that these corrections produce 1/epsilon
endpoint singularities which precisely cancel the finite-width divergences
arising in the resonant production of the W+ W- b bbar final state from
on-shell decays of the top and antitop quarks at the same order. We also
provide analytic results for the (m_t/Lambda)^2, (m_t/Lambda) and
(m_t/Lambda)^0 log(Lambda) terms that dominate the expansion in powers of
(Lambda/m_t) of the complete set of NNLO non-resonant corrections, where Lambda
is a cut imposed on the invariant masses of the b W pairs that is neither too
tight nor too loose (m_t Gamma_t << Lambda^2 << m_t^2).",1307.4337v2
2013-10-08,Single-layer MoS2 mechanical resonators,"Here, we demonstrate the fabrication of single-layer MoS2 mechanical
resonators. The fabricated resonators have fundamental resonance frequencies in
the order of 10 MHz to 30 MHz (depending on their geometry) and their quality
factor is about ~55 at room temperature in vacuum. The dynamical properties
clearly indicate that monolayer MoS2 membranes are in the membrane limit (i.e.,
tension dominated), in contrast to their thicker counterparts, which behave as
plates. We also demonstrate clear signatures of nonlinear behaviour of our
atomically thin membranes, thus providing a starting point for future
investigations on the nonlinear dynamics of monolayer nanomechanical
resonators.",1310.2134v2
2013-10-09,Spin resonance in AFe2Se2 with s-wave pairing symmetry,"We study spin resonance in the superconducting state of recently discovered
alkali-intercalated iron selenide materials A_xFe_(2-y)Se_2 (A=K,Rb,Cs) in
which the Fermi surface has only electron pockets. Recent angle-resolved
photoemission spectroscopy (ARPES) studies [M. Xu et al., Phys. Rev. B 85,
220504(R) (2012)] were interpreted as strong evidence for s-wave gap in these
materials, while the observation of the resonance peak in neutron scattering
measurements [G. Friemel et al., Phys. Rev. B 85, 140511 (2012)] suggests that
the gap must have different signs at Fermi surface points connected by the
momentum at which the resonance has been observed. We consider recently
proposed unconventional s+- superconducting state of A_xFe_(2-y)Se_2 with
superconducting gap changing sign between the hybridized electron pockets. We
argue that such a state supports a spin resonance. We compute the dynamical
structure factor and show that it is consistent with the results of inelastic
neutron scattering.",1310.2334v2
2013-10-15,Graviton resonances on two-field thick branes,"This work presents new results about the graviton massive spectrum in
two-field thick branes. Analyzing the massive spectra with a relative
probability method we have firstly showed the presence of resonance structures
and obtained a connection between the thickness of the defect and the lifetimes
of such resonances. We obtain another interesting results considering the
degenerate Bloch brane solutions. In these thick brane models, we have the
emergence of a splitting effect controlled by a degeneracy parameter. When the
degeneracy constant tends to a critical value, we have found massive resonances
to the gravitational field indicating the existence of modes highly coupled to
the brane. We also discussed the influence of the brane splitting effect over
the resonance lifetimes.",1310.4085v3
2013-10-17,Photonic Cavity Synchronization of Nanomechanical Oscillators,"Synchronization in oscillatory systems is a frequent natural phenomenon and
is becoming an important concept in modern physics. Nanomechanical resonators
are ideal systems for studying synchronization due to their controllable
oscillation properties and engineerable nonlinearities. Here we demonstrate
synchronization of two nanomechanical oscillators via a photonic resonator,
enabling optomechanical synchronization between mechanically isolated
nanomechanical resonators. Optical backaction gives rise to both reactive and
dissipative coupling of the mechanical resonators, leading to coherent
oscillation and mutual locking of resonators with dynamics beyond the widely
accepted phase oscillator (Kuramoto) model. Besides the phase difference
between the oscillators, also their amplitudes are coupled, resulting in the
emergence of sidebands around the synchronized carrier signal.",1310.4750v1
2013-11-01,"Tunable slowing, storing and releasing of a weak microwave field","We study the slowing, storing and releasing of microwave pulses in a
superconducting circuits composed of two coplanar waveguide resonators and a
superconducting transmon-type qubit. The quantum interference analogy to
electromagnetically induced transparency is created in two coupled resonators.
By tuning the resonance frequency of the transmon, we dynamically tune the
effective coupling between the resonators. Via the modulation of the coupling,
we show the tunable true time delay of microwave pulses at the single-photon
level. We also store the microwave field in a high-Q resonator and release the
signal from it to the output port. Our scheme promises applications in both
quantum information processing and classical wireless communications.",1311.0070v2
2013-11-04,"Resonance, Fermi surface topology, and Superconductivity in Cuprates","The resonance, a collective boson mode, was usually thought to be a possible
glue of superconductivity. We argue that it is rather a natural product of the
\emph{d}-wave pairing and the Fermi surface topology. A universal scaling
$E_{res}/2\Delta ^{H}_{S}\sim 1.0$ ($\Delta_{S}^{H}$ the magnitude of
superconducting gap at hot spot) is proposed for cuprates, irrespective of the
hole-/electron-doping, low-/high-energy resonance, monotonic/nonmonotonic
\emph{d}-wave paring, and the parameters selected. We reveal that there may
exist two resonance peaks in the electron-doped cuprates. The low- and high-
energy resonance, originated from the contributions of the different intra-band
component, is intimately associated with the Fermi surface topology. By
analyzing the data of inelastic neutron scattering, we conclude the
nonmonotonic \emph{d}-wave superconducting pairing symmetry in the
electron-doped cuprates, which is still an open question",1311.0611v1
2013-11-07,Mode spectrum and temporal soliton formation in optical microresonators,"The formation of temporal dissipative solitons in optical microresonators
enables compact, high repetition rate sources of ultra-short pulses as well as
low noise, broadband optical frequency combs with smooth spectral envelopes.
Here we study the influence of the resonator mode spectrum on temporal soliton
formation. Using frequency comb assisted diode laser spectroscopy, the measured
mode structure of crystalline MgF2 resonators are correlated with temporal
soliton formation. While an overal general anomalous dispersion is required, it
is found that higher order dispersion can be tolerated as long as it does not
dominate the resonator's mode structure. Mode coupling induced avoided
crossings in the resonator mode spectrum are found to prevent soliton
formation, when affecting resonator modes close to the pump laser. The
experimental observations are in excellent agreement with numerical simulations
based on the nonlinear coupled mode equations, which reveal the rich interplay
of mode crossings and soliton formation.",1311.1716v1
2013-11-26,Titan-Hyperion Resonance and the Tidal Q of Saturn,"Lainey et al. (2012), by re-analyzing long-baseline astrometry of Saturn's
moons, have found that the moons' tidal evolution is much faster than
previously thought, implying an order of magnitude stronger tidal dissipation
within Saturn. This result is controversial and implies recent formation of at
least some of the mid-sized icy moons of Saturn. Here we show that this more
intensive tidal dissipation is in full agreement with the evolved state of the
Titan-Hyperion resonance. This resonance was previously thought to be non-tidal
in origin, as the amount of tidal evolution required for its assembly is beyond
what is possible in models that assume that all the major moons are primordial.
We find that the survival of the Titan-Hyperion resonance is in agreement with
a past Titan-Iapetus 5:1 resonance, but not with unbroken tidal evolution of
Rhea from the rings to its current distance.",1311.6780v1
2013-12-03,Transmission phase of a quantum dot and statistical fluctuations of partial-width amplitudes,"Experimentally, the phase of the amplitude for electron transmission through
a quantum dot (transmission phase) shows the same pattern between consecutive
resonances. Such universal behavior, found for long sequences of resonances, is
caused by correlations of the signs of the partial-width amplitudes of the
resonances. We investigate the stability of these correlations in terms of a
statistical model. For a classically chaotic dot, the resonance eigenfunctions
are assumed to be Gaussian distributed. Under this hypothesis, statistical
fluctuations are found to reduce the tendency towards universal phase
evolution. Long sequences of resonances with universal behavior only persist in
the semiclassical limit of very large electron numbers in the dot and for
specific energy intervals. Numerical calculations qualitatively agree with the
statistical model but quantitatively are closer to universality.",1312.0873v2
2013-12-07,Resonant Auger-intercoulombic hybridized decay in the photoionization of endohedral fullerenes,"Considering the photoionization of Ar@C60, we predict resonant femtosecond
decays of both Ar and C60 vacancies through the continua of atom-fullerene
hybrid final states. The resulting resonances emerge from the interference
between simultaneous autoionizing and intercoulombic decay (ICD) processes. For
Ar 3s-->np excitations, these resonances are far stronger than the Ar-to-C60
resonant ICDs, while for C60 excitations they are strikingly larger than the
corresponding Auger features. The results indicate the power of hybridization
to enhance decay rates, and modify lifetimes and line profiles.",1312.2144v1
2013-12-10,Valley-dependent resonant tunneling through double magnetic barriers in suspended graphene,"We theoretically investigate the effects of strain-induced pseudomagnetic
fields on the transmission probability and the ballistic conductance for Dirac
fermion transport in suspended graphene. We show that resonant tunneling
through double magnetic barriers can be tuned by strain in the suspended
region. The valley-resolved transmission peaks are apparently distinguishable
owing to the sharpness of the resonant tunneling. With the specific strain, the
resonant tunneling is completely suppressed for Dirac fermions occupying the
one valley, but the resonant tunneling exists for the other valley. The
valley-filtering effect is expected to be measurable by strain engineering. The
proposed system can be used to fabricate a graphene valley filter with the
large valley polarization almost 100%.",1312.2667v2
2013-12-10,High speed nanotribology with quartz crystal resonators via Atomic Force Microscopy,"Friction measurements in the range of several meters per second are still of
great interests. With the atomic force microscopy (AFM), the oscilaltion
situation of the quartz crystal resonators of 3MHz resonance frequency are
studied. And the oscillation speed could reach up to several m/s. Then the
friction measurements are carried out on the Fischer Pattern, which is prepared
on the quartz crystal resonator. In this article, we present how to measure the
oscillation speeds of the quartz crystal resonator and the friction
measurements under different designs. Calibration method and the calculation
methods are also discussed in details. Although there are errors in the AFM
measurements due to the setup itself and the oscillating quartz which could
highly affect the sharpness of the cantilever tip, the results indicate that
the local friction coefficients with oscillation are higher than that without
oscillation.",1312.2817v1
2013-12-10,Slow sound propagation in lossy locally resonant periodic structures,"We investigate the sound propagation in an air-filled tube periodically
loaded with Helmholtz resonators. By tuning the Helmholtz with the Bragg
resonance, we study the efficiency of slow sound propagation in the presence of
the intrinsic viscothermal losses of the system. While in the lossless case the
overlapping of the resonances results in slow sound induced transparency of a
narrow frequency band surrounded by a strong and broadband gap, the inclusion
of the unavoidable losses imposes limits to the slowdown factor and the maximum
transmission. Experiments, theory and finite element simulations have been used
for the characterization of acoustic wave propagation. Experiments, in good
agreement with the lossy theory, reveal the possibility of slowing sound at low
frequencies by 20 times. A trade-off among the relevant parameters (delay time,
maximum transmission, bandwidth) as a function of the tuning between Bragg and
Helmholtz resonance frequency is also presented.",1312.2851v1
2014-01-02,Microwave-driven Topological Resonant Excitations of Coupled Skyrmions,"We study nonlinear dynamics of coupled Skyrmions and present a method for
manipulating topological resonant excitations by a dual-frequency microwave
field. Thiele's equation is extended by introducing a new effective mass
associated with time derivative of topological density. Two coupled resonant
modes endowed with the new effective mass are found in the coupled Skyrmions.
Polygon-like resonant excitations are observed and modulated when the two modes
are activated simultaneously by microwave field with commensurate frequency
ratio. Quasiperiodic behavior of excitations are related to an incommensurate
ratio. Numerical solutions based on the extended Thiele's equation for Skyrmion
under a dual-frequency field agree well with the micromagnetic simulation
results and clarify the importance of frequency value, frequency ratio of an
external field and the effective mass to the polygon-like dynamics of Skyrmion.
We also show the coupling between two Skyrmions can dominate their topological
resonant excitations.",1401.0373v2
2014-01-13,Enhancing narrowband high order harmonic generation by Fano resonances,"Resonances in the photo-absorption spectrum of the generating medium can
modify the spectrum of high order harmonics. In particular, window-type Fano
resonances can reduce photo-absorption within a narrow spectral region and,
consequently, lead to an enhanced emission of high-order harmonics in
absorption-limited generation conditions. For high harmonic generation in argon
it is shown that the 3s3p6 np 1P1 window resonances (n=4,5,6) give rise to
enhanced photon yield. In particular, the 3s3p6 4p 1P1 resonance at 26.6 eV
allows a relative enhancement up to a factor of 30 compared to the
characteristic photon emission of the neighboring harmonic order. This
enhanced, spectrally isolated and coherent photon emission line has a relative
energy bandwidth of only {\Delta}E/E=3*10-3. Therefore, it might be directly
applied for precision spectroscopy or coherent diffractive imaging without the
need of additional spectral filtering. The presented mechanism can be employed
for tailoring and controlling the high harmonic emission of manifold target
materials.",1401.2947v1
2014-01-17,Controlled lasing from active optomechanical resonators,"Planar microcavities with distributed Bragg reflectors (DBRs) host, besides
confined optical modes, also mechanical resonances due to stop bands in the
phonon dispersion relation of the DBRs. These resonances have frequencies in
the sub-terahertz (10E10-10E11 Hz) range with quality factors exceeding 1000.
The interaction of photons and phonons in such optomechanical systems can be
drastically enhanced, opening a new route toward manipulation of light. Here we
implemented active semiconducting layers into the microcavity to obtain a
vertical-cavity surface-emitting laser (VCSEL). Thereby three resonant
excitations -photons, phonons, and electrons- can interact strongly with each
other providing control of the VCSEL laser emission: a picosecond strain pulse
injected into the VCSEL excites long-living mechanical resonances therein. As a
result, modulation of the lasing intensity at frequencies up to 40 GHz is
observed. From these findings prospective applications such as THz laser
control and stimulated phonon emission may emerge.",1401.4359v1
2014-01-28,Quantifying resonant activation like phenomenon in non-Markovian systems,"Resonant activation is an effect of a noise-induced escape over a modulated
potential barrier. The modulation of a energy landscape facilitates the escape
kinetics and makes it optimal as measured by the mean first passage time. A
canonical example of resonant activation is a Brownian particle moving in a
time-dependent potential under action of Gaussian white noise. Resonant
activation is observed not only in typical Markovian-Gaussian systems but also
in far from equilibrium and far from Markovianity regimes. We demonstrate that
using an alternative to the mean first passage time, robust measures of
resonant activation, the signature of this effect can be observed in general
continuous time random walks in modulated potentials even in situations when
the mean first passage time diverges.",1401.7246v2
2014-02-06,Saturn Ring Seismology: Looking Beyond First Order Resonances,"Some wave features found in the C-ring of Saturn appear to be excited by
resonances with normal mode oscillations of the planet. The waves are found at
locations in the rings where the ratio of orbital to oscillation frequencies is
given by m : m+1 where m is a small integer. I suggest here that it is
plausible that ring waves may also be launched at second order resonances,
where the frequency ratio would be m : m+2. Indeed, otherwise unassociated wave
features are found at such locations in the C-ring. If confirmed the
association of planetary modes with additional C-ring wave features would
measure additional oscillation frequencies of Saturn and improve the utility of
the waves for constraining the internal structure of the planet. Second-order
resonances in general do not lie near first order ring resonance locations and
thus are not the explanation for the apparent frequency splitting of modes.",1402.1415v1
2014-02-07,On the complex branch points in $πN$ scattering amplitude and the multiple poles feature of resonances,"A simple heuristic argument to understand the existence of complex branch
points in the $\pi N$ scattering amplitude is presented.
  It is based on a hypothesis that the singularity structure of the $\pi N$
scattering amplitude is a smooth varying function of the pion mass. We then
show that the two-pole structure found to correspond to the Roper resonance
could just a simple direct mathematical consequence of including additional
Riemann surface in the analysis. Our study indicates that it is always possible
to have multiple poles, either two or four etc., in different Riemann sheet, to
be associated with a resonance. The poles in all Riemann sheets should be
looked for to determine whether the two-pole feature of the Roper resonance
$N^*(1440)$ is a manifestation of the ""exact degeneracy"" discussed here but
masked by numerical indeterminacy, or an ""accidental"" one. The determination of
the multiplicity of a pole could provide some information of the analytical
structure of the numerator of the pole term, as the numerator of the pole term
is related to resonance form factor.",1402.1571v2
2014-02-11,"Spectroscopy of the D1-transition of cesium by dressed-state resonance fluorescence from a single (In,Ga)As/GaAs quantum dot","We use a laser-driven single (In,Ga)As quantum dot (QD) in the dressed state
regime of resonance fluorescence ($T = 4$ K) to observe the four
$D_1$-transition lines of alkali atomic cesium ($Cs$) vapor at room
temperature. We tune the frequency of the dressing continuous-wave laser in the
vicinity of the bare QD resonance $\sim 335.116$ THz ($\sim 894.592$ nm) at
constant excitation power and thereby controllably tune the center and side
channel frequencies of the probe light, i.e. the Mollow triplet. Resonances
between individual QD Mollow triplet lines and the atomic hyperfine-split
transitions are clearly identified in the $Cs$ absorption spectrum. Our results
show that narrow-band (In,Ga)As QD resonance fluorescence (RF) is suitable to
optically address individual transitions of the $D_1$ quadruplet without
applying magnetic field or electric field tuning.",1402.2396v1
2014-02-16,Electron-impact resonant vibrational excitation and dissociation processes involving vibrationally excited N2 molecules,"Resonant vibrational excitation cross sections and the corresponding rate
coefficients for electron-N$_2$ collisions occurring through the
N$_2^-(\textrm{X}\ ^2\Pi_g)$ resonant state are reviewed. New calculations are
performed using accurate potential energies curves for the N$_2$ electronic
ground state, taken from literature, and for the N$_2^-$ resonant state,
obtained from $R$-matrix calculations. The calculations are extended also to
the resonant excitation processes involving the N$_2$ ground state vibrational
continuum, leading to dissociation. Electron impact dissociation is found to be
significant from higher vibrational levels. Accurate analytical fits for the
complete set of the rate coefficients are provided. The behavior of the
dissociative cross sections is investigated for rotationally excited N$_2$
molecules, with $J=50,100$ and 150 and for different vibrational levels.",1402.3814v2
2014-02-21,Broadband terahertz generation from metamaterials,"The terahertz spectral regime, ranging from about 0.1 to 15 THz, is one of
the least explored yet most technologically transformative spectral regions.
One current challenge is to develop efficient and compact terahertz
emitters/detectors with a broadband and gapless spectrum that can be tailored
for various pump photon energies. Here we demonstrate efficient single-cycle
broadband THz generation, ranging from about 0.1 to 4 THz, from a thin layer of
split-ring resonators with few tens of nanometers thickness by pumping at the
telecommunications wavelength of 1.5 micrometer (200 THz). The terahertz
emission arises from exciting the magnetic-dipole resonance of the split-ring
resonators and quickly decreases under off-resonance pumping. This, together
with pump polarization dependence and power scaling of the terahertz emission,
identifies the role of optically induced nonlinear currents in split-ring
resonators. We also reveal a giant sheet nonlinear susceptibility
$\sim$10$^{-16}$ m$^2$V$^{-1}$ that far exceeds thin films and bulk
non-centrosymmetric materials.",1402.5203v1
2014-02-25,Observation of the Second Triatomic Resonance in Efimov's Scenario,"We report the observation of a three-body recombination resonance in an
ultracold gas of cesium atoms at a very large negative value of the $s$-wave
scattering length. The resonance is identified as the second triatomic Efimov
resonance, which corresponds to the situation where the first excited Efimov
state appears at the threshold of three free atoms. This observation, together
with a finite-temperature analysis and the known first resonance, allows the
most accurate demonstration to date of the discrete scaling behavior at the
heart of Efimov physics. For the system of three identical bosons, we obtain a
scaling factor of $21.0(1.3)$, close to the ideal value of $22.7$.",1402.6161v2
2014-04-02,Controlling the interactions of a few cold Rb Rydberg atoms by radiofrequency-assisted Förster resonances,"Long-range interactions between cold Rydberg atoms, which are used in many
important applications, can be enhanced using F\""orster resonances between
collective many-body states controlled by an external electric field. Here we
report on the first experimental observation of highly-resolved
radio-frequency-assisted F\""orster resonances in a few cold Rb Rydberg atoms.
We also observed radio-frequency-induced F\""orster resonances which cannot be
tuned by a dc electric field. They imply an efficient transition from van der
Waals to resonant dipole-dipole interaction due to Floquet sidebands of Rydberg
levels appearing in the rf-field. This method can be applied to enhance the
interactions of almost arbitrary Rydberg atoms with large principal quantum
numbers.",1404.0438v2
2014-04-07,$^4{\rm He}$+$n$+$n$ continuum within an ab initio framework,"The low-lying continuum spectrum of the $^6{\rm He}$ nucleus is investigated
for the first time within an ab initio framework that encompasses the $^4{\rm
He}$+$n$+$n$ three-cluster dynamics characterizing its lowest decay channel.
This is achieved through an extension of the no-core-shell model combined with
the resonating-group method, in which energy-independent non-local interactions
among three nuclear fragments can be calculated microscopically starting from
realistic nucleon-nucleon interactions and consistent ab initio many-body wave
functions of the clusters. The three-cluster Schr\""odinger equation is solved
with three-body scattering boundary conditions by means of the
hyperspherical-harmonic method on a Lagrange mesh. Using a soft
similarity-renormalization-group evolved chiral nucleon-nucleon potential, we
find the known $J^\pi = 2^+$ resonance as well as a result consistent with a
new low-lying second $2^+$ resonance recently observed at GANIL at $2.6$ MeV
above the $^6$He ground state. We also find resonances in the $2^-$, $1^+$ and
$0^-$ channels, while no low-lying resonances are present in the $0^+$ and
$1^-$ channels.",1404.1960v1
2014-04-08,"Strength of the $E_{\text{p}}$=1.842 MeV resonance in the $^{40}$Ca(p,$γ$)$^{41}$Sc reaction revisited","The strength of the $E_{\rm p} = 1.842$ MeV resonance in the
$^{40}$Ca(p,$\gamma$)$^{41}$Sc reaction is determined with two different
methods: First, by an absolute strength measurement using calcium hydroxide
targets, and second, relative to the well-determined strength of the resonance
triplet at $E_\alpha$ = 4.5 MeV in the $^{40}$Ca($\alpha$,$\gamma$)$^{44}$Ti
reaction. The present new value of $\omega\gamma=(0.192\pm0.017)$ eV is 37%
(equivalent to $3.5\sigma$) higher than the evaluated literature value. In
addition, the ratio of the strengths of the 1.842 MeV
$^{40}$Ca(p,$\gamma$)$^{41}$Sc and 4.5 MeV
$^{40}$Ca($\alpha$,$\gamma$)$^{44}$Ti resonances has been determined to be
$0.0229\pm0.0018$. The newly corrected strength of the 1.842-MeV resonance can
be used in the future as a normalization point for experiments with calcium
targets.",1404.2062v1
2014-04-08,Resonant Spin Wave Excitation by Terahertz Magnetic Near-field Enhanced with Split Ring Resonator,"Excitation of antiferromagnetic spin waves in HoFeO$_{3}$ crystal combined
with a split ring resonator (SRR) is studied using terahertz (THz)
electromagnetic pulses. The magnetic field in the vicinity of the SRR induced
by the incident THz electric field component excites and the Faraday rotation
of the polarization of a near-infrared probe pulse directly measures
oscillations that correspond to the antiferromagnetic spin resonance mode. The
good agreement of the temperature-dependent magnetization dynamics with the
calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms
that the spin wave is resonantly excited by the THz magnetic near-field
enhanced at the LC resonance frequency of the SRR, which is 20 times stronger
than the incident magnetic field.",1404.2179v1
2014-04-09,Active plasma resonance spectroscopy: Eigenfunction solutions in spherical geometry,"The term Active Plasma Resonance Spectroscopy (APRS) denotes a class of
related techniques which utilize, for diagnostic purposes, the natural ability
of plasmas to resonate on or near the electron plasma frequency: A radio
frequent signal (in the GHz range) is coupled into the plasma via an antenna or
probe, the spectral response is recorded, and a mathematical model is used to
determine plasma parameters like the electron density or the electron
temperature. Based on the cold plasma model, this manuscript provides the
general analytic expression of the electrical admittance of a spherical shaped
probe immersed into a plasma. It is derived from the matrix representation of
an appropriate operator, which describes the dynamical behavior of the
probe-plasma system. This dynamical operator can be split into a conservative
operator and a dissipative operator. It can be shown that the eigenvalues of
the conservative operator represent the resonance frequencies of the
probe-plasma system which are simply connected to the electron density. As an
example, the result is applied to the spherical impedance probe and the
multipole resonance probe.",1404.2432v1
2014-04-15,"Additional resonant contribution to the potential model for the 12C(alpha,gamma)16O reaction","The additional resonant contribution to the potential model is examined in
$\alpha$+$^{12}$C elastic scattering and the low-energy
$^{12}$C($\alpha$,$\gamma$)$^{16}$O reaction. The excitation function of
elastic scattering below $E_{c.m.}= 5$ MeV seems to be reproduced by the
potential model satisfactorily, and it is not profoundly disturbed by the
additional resonances. The weak coupling is good enough to describe the
$^{16}$O structure in the vicinity of the $\alpha$-particle threshold,
especially below $E_{c.m.}= 8$ MeV, corresponding to the excitation energy $E_x
\approx 15$ MeV. The additional resonances give the complement of the
astrophysical $S$-factors from the simple potential model. The $S$-factor of
$^{12}$C($\alpha$,$\gamma$)$^{16}$O at $E_{c.m.}=300$ keV is dominated by the
$E$2 transition, which is enhanced by the subthreshold 2$^+_1$ state at $E_x=
6.92$ MeV. The contribution from the subthreshold 1$^-_1$ state at $E_x= 7.12$
MeV is predicted to be small. The additional resonances do not give the large
contribution to the thermonuclear reaction rates of
$^{12}$C($\alpha$,$\gamma$)$^{16}$O at helium burning temperatures.",1404.3966v1
2014-04-24,The composite nature of the $Λ(1520)$ resonance,"Recently, the Weinberg compositeness condition of a bound state was
generalized to account for resonant states and higher partial waves. We apply
this extension to the case of the $\Lambda(1520)$ resonance and quantify the
weight of the meson-baryon components in contrast to other possible genuine
building blocks. This resonance was theoretically obtained from a coupled
channels analysis using the s-waves $\pi\Sigma^*$, $K\Xi^*$ and the d-waves
$\bar{K}N$ and $\pi\Sigma$ channels applying the techniques of the chiral
unitary approach. We obtain that this resonance is essentially dynamically
generated from these meson-baryon channels, leaving room for only $15 \%$
weight of other kind of components into its wave function.",1404.6128v2
2014-07-05,Nonlinear Interference effect for Optical Clocks in Yb Atoms,"In this paper, two-photon absorption resonance has been investigated . We
studied this phenomenon in three-level system with common upper level, two
lower long-life levels and two quasi-resonant laser fields with different
frequency spectrum. It has been shown that, the absorption coefficient in the
far distance from absorption line at the frequency of two-photon resonance has
considerable amplitude and narrow width. Frequency difference between two lower
levels is transition frequency for optical clocks. This resonance is much less
sensitive to the effects of noise components and probing fields compared with
electromagnetically induced transparency. Stark shift of the two-photon
resonance can be offset and reduced by the changes in the probing field
amplitude. We recommended to use an additional laser with narrow line to
stabilize the frequency at optical clock to get a line in sub-Hertz range.",1407.1410v3
2014-07-12,Resonator-Assisted Quantum Bath Engineering of a Flux Qubit,"We demonstrate quantum bath engineering for preparation of any orbital state
with controllable phase factor of a superconducting flux qubit assisted by a
microwave coplanar waveguide resonator. We investigate the polarization
efficiency of the arbitrary direction rotating on the Bloch sphere, and obtain
an effective Rabi frequency by using the convergence condition of Markovian
master equation. The processes of polarization can be implemented effectively
in a dissipative environment created by resonator photon loss when the spectrum
of the microwave resonator matches with the specially tailored Rabi and
resonant frequencies of the drive. Our calculations indicate that
state-preparation fidelities in excess of 99\% and the required time on the
order of magnitude of microsecond are in principle possible for experimentally
reasonable sample parameters. Furthermore, our proposal could be applied to
other systems with spin-based qubits.",1407.3337v4
2014-07-18,Coupling of a locally implanted rare-earth ion ensemble to a superconducting micro-resonator,"We demonstrate the coupling of rare-earth ions locally implanted in a
substrate (Gd$^{3+}$ in Al$_{2}$O$_{3}$) to a superconducting NbN
lumped-element micro-resonator. The hybrid device is fabricated by a controlled
ion implantation of rare-earth ions in well-defined micron-sized areas, aligned
to lithographically defined micro-resonators. The technique does not degrade
the internal quality factor of the resonators which remain above $10^{5}$.
Using microwave absorption spectroscopy we observe electron-spin resonances in
good agreement with numerical modelling and extract corresponding coupling
rates of the order of $1$ MHz and spin linewidths of $50 - 65$ MHz.",1407.5064v4
2014-07-28,Remarks on pole trajectories for resonances,"We discuss in general terms pole trajectories of resonances coupling to a
continuum channel as some strength parameter is varied. It is demonstrated
that, regardless the underlying dynamics, the trajectories of poles that couple
to the continuum in a partial wave higher than s-wave are qualitatively the
same, while in case of s-waves the pole trajectory can reveal important
information on the internal structure of the resonance. In addition we show
that only molecular (or extraordinary) states appear near thresholds naturally,
while more compact structures need a significant fine tuning in the parameters.
  This study is of current relevance especially in strong interaction physics,
since lattice QCD may be employed to deduce the pole trajectories for hadronic
resonances as a function of the quark mass thus providing additional, new
access to the structure of s-wave resonances.",1407.7452v1
2014-08-01,One dimensional scattering from two-piece rising potentials: a new avenue of resonances,"We study scattering from potentials that rise monotonically on one side; this
is generally avoided. We report that resonant states are absent in such
potentials when they are smooth and single-piece having less than three real
turning points (like in the cases of Morse oscillator, exponential and linear
potentials). But when these potentials are made two-piece, resonances can
occur. We further show that rising potentials next to a well/step/barrier are
rich models of multiple resonances (Gamow's decaying states) in one- dimension.
We use linear, parabolic and exponential profiles as rising part and find
complex-energy poles, ${\cal E}_n=E_n-i\Gamma_n/2$ $(\Gamma_n > 0)$, in the
reflection amplitude (s-matrix). The appearance of peaks in Wigner's
(reflection) time-delay at $E=\epsilon_n$ (close to $E_n$) and spatial
catastrophe in the eigenfunction confirm the existence of resonances and
meta-stable states in these systems. PACS Nos.: 03.65.-w, 03.65.Nk",1408.0231v1
2014-08-07,Which resonances in small metallic nanoparticles are plasmonic?,"We use time-dependent density functional theory to examine the character of
various resonances corresponding to peaks in the optical response of small
metallic nanoparticles. Each resonance has both ""sloshing"" and ""inversion""
character. The sloshing mode is an oscillation in the occupation of the shells
nearest the Fermi energy, transferring charge back and forth from below the
Fermi level to above it. It results in oscillation in charge density near the
surface of the particle. Inversions monotonically move charge from occupied to
unoccupied states, and result in oscillation in charge density in the core of
the particle. We also discuss the dependence of the optical response on the
size of the simulation grid, noting that the character of resonances appears
stable with respect to changes in simulation size, even though the details of
the spectrum change. This makes a reliable characterization possible. We
consider what characteristics are important in deciding that a resonance is
plasmonic.",1408.1895v1
2014-08-13,Thermoelectric effect enhanced by the resonant states in graphene,"Thermoelectric effects in graphene are considered theoretically with
particular attention paid to the role of impurities. Using the T -matrix method
we calculate the impurity resonant states and the momentum relaxation time due
to scattering on impurities. The Boltzmann kinetic equation is used to
determine the thermoelectric coefficients. It is shown that the resonant
impurity states near the Fermi level give rise to a resonant enhancement of the
Seebeck coefficient and of the figure of merit $ZT$ . The Wiedemann-Franz ratio
deviates from that known for ordinary metals, where this ratio is constant and
equal to the Lorentz number. This deviation appears for small chemical
potentials and in the vicinity of the resonant states. In the limit of a
constant relaxation time, this ratio has been calculated analytically for
$\mu=0$.",1408.2990v1
2014-08-20,Niobium stripline resonators for microwave studies on superconductors,"Microwave spectroscopy is a powerful experimental tool to reveal information
on the intrinsic properties of superconductors. Superconducting stripline
resonators, where the material under study constitutes one of the ground
planes, offer a high sensitivity to investigate superconducting bulk samples.
In order to improve this measurement technique, we have studied stripline
resonators made of niobium, and we compare the results to lead stripline
resonators. With this technique we are able to determine the temperature
dependence of the complex conductivity of niobium and the energy gap
$\Delta(0)=2.1$ meV. Finally we show measurements at the superconducting
transition of a tantalum bulk sample using niobium stripline resonators.",1408.4727v1
2014-08-22,"Strength of the E_R = 127 keV, 26Al(p,g)27Si resonance","We examine the impact of the strength of the E_R = 127 keV, 26Al(p,g)27Si
resonance on 26Al production in classical nova explosions and asymptotic giant
branch (AGB) stars. Thermonuclear 26Al(p,g)27Si reaction rates are determined
using different assumed strengths for this resonance and representative stellar
model calculations of these astrophysical environments are performed using
these different rates. Predicted 26Al yields in our models are not sensitive to
differences in rates determined using zero and a commonly stated upper limit
corresponding to wg_UL = 0.0042 micro-eV for this resonance strength. Yields of
26Al decrease by 6% and, more significantly, up to 30%, when a strength of 24 x
wg_UL = 0.1 micro-eV is assumed in the adopted nova and AGB star models,
respectively. Given that the value of wg_UL was deduced from a single,
background-dominated 26Al(3He,d)27Si experiment where only upper limits on
differential cross sections were determined, we encourage new experiments to
confirm the strength of the 127 keV resonance.",1408.5227v1
2014-09-10,Strongly Intensive Measures for Particle Number Fluctuations: Effects of Hadronic Resonances,"Strongly intensive measures $\Delta$ and $\Sigma$ are used to study
event-by-event fluctuations of hadron multiplicities in nucleus-nucleus
collisions. The effects of resonance decays are investigated within statistical
model and relativistic transport model. Two specific examples are considered:
resonance decays to two positively charged particles (e.g.,
$\Delta^{++}\rightarrow p+ \pi^+$) and to $\pi^+\pi^-$-pairs. (e.g.,
$\rho^0\rightarrow \pi^-+\pi^+$). It is shown that resonance abundances at the
chemical freeze-out can be estimated by measuring the fluctuations of the
number of stable hadrons. These model results are compared to the full
hadron-resonance gas analysis within both the grand canonical and canonical
ensemble. The ultra-relativistic quantum molecular dynamics (UrQMD) model of
nucleus-nucleus collisions is used to illustrate the role of global charge
conservation, centrality selection, and limited experimental acceptance.",1409.3023v2
2014-09-12,Enhancement of polarizabilities of cylinders with cylinder-slab resonances,"If an object is very small in size compared with the wavelength of light, it
does not scatter light efficiently. It is hence difficult to detect a very
small object with light. We show using analytic theory as well as full wave
numerical calculation that the effective polarizability of a small cylinder can
be greatly enhanced by coupling it with a superlens type metamaterial slab.
This kind of enhancement is not due to the individual resonance effect of the
metamaterial slab, nor due to that of the object, but is caused by a collective
resonant mode between the cylinder and the slab. We show that this type of
particle-slab resonance which makes a small two-dimensional object much
brighter is actually closely related to the reverse effect known in the
literature as cloaking by anomalous resonance which can make a small cylinder
undetectable. We also show that the enhancement of polarizability can lead to
strongly enhanced electromagnetic forces that can be attractive or repulsive,
depending on the material properties of the cylinder.",1409.3680v1
2014-09-24,Interband interaction between Ge states and surface resonance band of Pb on Ge(001),"We investigate the valence band structure of Pb on Ge(001) by Angle-Resolved
Photoelectron Spectroscopy. Three Ge bands, G1, G2, and G3, were observed on
Ge(001) 2x1 clean surface. In addition to these three bands, a forth band (R
band) is found in the 2 ML of Pb coverage. The R band continues to appear even
when the surface superstructure changed. The position of the R band does not
depend on Pb coverage. These results indicate that the R band derives from Ge
subsurface states known as surface resonance states. Furthermore, the effective
mass of G3 is significantly reduced when this forth band exists. We found that
this reduction of the G3 effective mass was explained by the interaction of the
G3 and the surface resonance band. Consequently, the surface resonance band
penetrates the Ge subsurface region affecting the Ge bulk states. We observed
the hybridization between Ge states and the surface resonance states induced by
Pb adsorption.",1409.6832v1
2014-09-25,Resonance modes in stereometamaterial of square split ring resonators connected by sharing the gap,"Stereometamaerials can fully utilize the 3D degrees of freedom to exploit the
coupling and hybridization between multiple split ring resonators (SRRs),
enabling more extraordinary resonances and properties over their planar
counterparts. Here we propose and numerically study a kind of structure based
on connected SRRs sharing their gap in a rotational fashion. It is shown that
there are three typical resonance modes in such cage-like SRR (C-SRR)
stereometamaterial in the communication and near infrared range. In the order
of increasing energy, these modes can be essentially ascribed to magnetic
torodial dipole, magnetic dipole, and a mixture of electric-dipole and magnetic
toroidal dipole. We show that the latter two are derived from the second-order
mode in the corresponding individual SRR, while the first one from the
fundamental one. The highest energy mode remains relatively ""dark"" in an
individual C-SRR due to the high-order feature and the rotational symmetry.
However, they are all easily excitable in a C-SRR array, offering multiband
filtering functionality.",1409.7138v1
2014-09-30,Green's function method for single-particle resonant states in relativistic mean field theory,"Relativistic mean field theory is formulated with the Green's function method
in coordinate space to investigate the single-particle bound states and
resonant states on the same footing. Taking the density of states for free
particle as a reference, the energies and widths of single-particle resonant
states are extracted from the density of states without any ambiguity. As an
example, the energies and widths for single-neutron resonant states in
$^{120}$Sn are compared with those obtained by the scattering phase-shift
method, the analytic continuation in the coupling constant approach, the real
stabilization method and the complex scaling method. Excellent agreements are
found for the energies and widths of single-neutron resonant states.",1409.8412v1
2014-10-01,Resonances for Thin Barriers on the Circle,"We study high energy resonances for the operator
$-\Delta_{V,\partial\Omega}:=-\Delta+\delta_{\partial\Omega}\otimes V $ when
$V$ has strong frequency dependence. The operator $-\Delta_{V,\partial\Omega}$
is a Hamiltonian used to model both quantum corrals and leaky quantum graphs.
Since highly frequency dependent delta potentials are out of reach of the more
general techniques in previous work, we study the special case where
$\Omega=B(0,1)\subset \mathbb{R}^2$ and $V\equiv h^{-\alpha }V_0>0$ with
$\alpha\leq 1$. Here $h^{-1}\sim \Re \lambda$ is the frequency. We give sharp
bounds on the size of resonance free regions for $\alpha\leq 1$ and the
location of bands of resonances when $5/6\leq \alpha\leq 1$. Finally, we give a
lower bound on the number of resonances in logarithmic size strips: $-M\log \Re
\lambda\leq \Im \lambda \leq 0$.",1410.0340v5
2014-10-03,Vortices at the magnetic equator generated by hybrid Alfven resonant waves,"We performed three-dimensional magnetohydrodynamic simulations of shear
Alfven waves in a full field line system with magnetosphere-ionosphere coupling
and plasma non-uniformities. Feedback instability of the Alfven resonant modes
showed various nonlinear features under the field line cavities: i) a secondary
flow shear instability occurs at the magnetic equator, ii) trapping of the
ionospheric Alfven resonant modes facilitates deformation of field-aligned
current structures, and iii) hybrid Alfven resonant modes grow to cause
vortices and magnetic oscillations around the magnetic equator. Essential
features in the initial brightening of auroral arc at substorm onsets could be
explained by the dynamics of Alfven resonant modes, which are the nature of the
field line system responding to a background rapid change.",1410.0764v1
2014-10-09,Special mean motion resonance pairs: Mimas-Tethys and Titan-Hyperion,"Five pairs of large solar system satellites occupy first order mean-motion
resonances (MMRs). Among these, the pairs of Mimas-Tethys and Titan-Hyperion
are special. They are located much deeper in resonance than the others and
their critical arguments librate with much greater amplitudes. These
characteristics are traced to the insignificant damping, over $\Gyr$
timescales, of Mimas's orbital inclination and Hyperion's orbital eccentricity.
Absent that, these resonances would not survive. Instead their librations would
be overstable and escape from resonance would occur on the relevant damping
time. Unlike the aforementioned MMRs, those involving Enceladus-Dione,
Io-Europa, and Europa-Ganymede are limited by eccentricity damping. They must
either remain at the shallow depths they currently occupy, or, if they venture
deeper, retreat after a limited time. The latter seems almost certain for
Enceladus-Dione and quite likely for the others, We examine the MMRs involving
Mimas-Tethys and Titan-Hyperion under the assumption that they formed as a
result of convergent migration. Capture probabilities are $\sim 6\%$ for the
former and $100\%$ for the latter. The possibility of collisional excitation of
their large librations is investigated but largely discounted.",1410.2648v1
2014-10-13,Photothermally Excited Contact Resonance Imaging in Air and Water,"Contact Resonance Force Microscopy (CR-FM) is a leading AFM technique for
measuring viscoelastic nano-mechanical properties. Conventional piezo-excited
CR-FM measurements have been limited to imaging in air, since the ""forest of
peaks"" frequency response associated with acoustic excitation methods
effectively masks the true cantilever resonance. Using photothermal actuation
results in clean contact resonance spectra, that closely match the ideal
frequency response of the cantilever, allowing unambiguous and simple resonance
frequency and quality factor measurements in air and liquids alike. This
extends the capabilities of CR-FM to biologically relevant and other soft
samples in liquid environments. We demonstrate CR-FM in air and water on both
stiff silicon/titanium samples and softer
polystyrene-polyethylene-polypropylene polymer samples with the quantitative
moduli having very good agreement between expected and measured in both
environments.",1410.3311v1
2014-10-14,Controlling interactions between highly-magnetic atoms with Feshbach resonances,"This paper reviews current experimental and theoretical progress in the study
of dipolar quantum gases of ground and meta-stable atoms with a large magnetic
moment. We emphasize the anisotropic nature of Feshbach resonances due to
coupling to fast-rotating resonant molecular states in ultracold s-wave
collisions between magnetic atoms in external magnetic fields. The dramatic
differences in the distribution of resonances of magnetic $^7$S$_3$ chromium
and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron
angular momentum is analyzed. We focus on Dysprosium and Erbium as important
experimental advances have been recently made to cool and create
quantum-degenerate gases for these atoms. Finally, we describe progress in
locating resonances in collisions of meta-stable magnetic atoms in electronic P
states with ground-state atoms, where an interplay between collisional
anisotropies and spin-orbit coupling exists.",1410.3873v1
2014-10-16,Resonance spectra of caged black holes,"Recent numerical studies of the coupled Einstein-Klein-Gordon system in a
cavity have provided compelling evidence that {\it confined} scalar fields
generically collapse to form black holes. Motivated by this intriguing
discovery, we here use analytical tools in order to study the characteristic
resonance spectra of the confined fields. These discrete resonant frequencies
are expected to dominate the late-time dynamics of the coupled
black-hole-field-cage system. We consider caged Reissner-Nordstr\""om black
holes whose confining mirrors are placed in the near-horizon region
$x_{\text{m}}\equiv (r_{\text{m}}-r_+)/r_+\ll\tau\equiv (r_+-r_-)/r_+$ (here
$r_{\text{m}}$ is the radius of the confining mirror and $r_{\pm}$ are the
radii of the black-hole horizons). We obtain a simple analytical expression for
the fundamental quasinormal resonances of the coupled black-hole-field-cage
system: $\omega_n=-i2\pi T_{\text{BH}}\cdot n[1+O(x^n_{\text{m}}/\tau^n)]$,
where $T_{\text{BH}}$ is the temperature of the caged black hole and
$n=1,2,3,...$ is the resonance parameter.",1410.4567v1
2014-10-20,Comparison of gold- and graphene-based resonant nano-structures for terahertz metamaterials and an ultra-thin graphene-based modulator,"Graphene exhibits unique material properties and in electromagnetic wave
technology, it raises the prospect of devices miniaturized down to the atomic
length scale. Here we study split-ring resonator metamaterials made from
graphene and we compare them to gold-based metamaterials. We find that
graphene's huge reactive response derived from its large kinetic inductance
allows for deeply subwavelength resonances, although its resonance strength is
reduced due to higher dissipative loss damping and smaller dipole coupling.
Nevertheless, tightly stacked graphene rings may provide for negative
permeability and the electric dipole resonance of graphene meta-atoms turns out
to be surprisingly strong. Based on these findings, we present a terahertz
modulator based on a metamaterial with a multi-layer stack of alternating
patterned graphene sheets separated by dielectric spacers. Neighbouring
graphene flakes are biased against each other, resulting in modulation depths
of over 75% at a transmission level of around 90%.",1410.5318v1
2014-10-30,Simple method for locking birefringent resonators,"We report on a simple method of locking a laser to a birefringent cavity
using polarization spectroscopy. The birefringence of the resonator permits the
simple extraction of an error signal by using one polarization state as a phase
reference for another state. No modulation of the light or the resonator is
required, reducing the complexity of the laser locking setup. This method of
producing an error signal can be used on most birefringent optical resonators,
even if the details of birefringence and eigenpolarizations are not known. This
technique is particularly well suited for fiber ring resonators due to the
inherent birefringence of the fiber and the unknown nature of that
birefringence. We present an experimental demonstration of this technique using
a fiber ring.",1410.8569v1
2014-11-03,Analysis of the Crystal Ball data on $K^-p\toπ^0Σ^0$ reaction with center-of-mass energies of $1536\sim 1676$ MeV,"With an effective Lagrangian approach, we analyze the $K^-p\to \pi^0\Sigma^0$
reaction to study the $\Lambda$ hyperon resonances by fitting the Crystal Ball
data on differential cross sections and $\Sigma^0$ polarization with the
center-of-mass energies of $1536\sim 1676$ MeV. Besides well established PDG
4-star $\Lambda$ resonances around this energy range, the $\Lambda(1600){1\over
2}^+$ resonance, listed as a 3-star resonance in PDG, is found to be definitely
needed. In addition, there is strong evidence for the existence of a new
$\Lambda({3\over 2}^+)$ resonance around 1680 MeV.",1411.0486v1
2014-11-07,Resonant conversions of QCD axions into hidden axions and suppressed isocurvature perturbations,"We study in detail MSW-like resonant conversions of QCD axions into hidden
axions, including cases where the adiabaticity condition is only marginally
satisfied, and where anharmonic effects are non-negligible. When the resonant
conversion is efficient, the QCD axion abundance is suppressed by the hidden
and QCD axion mass ratio. We find that, when the resonant conversion is
incomplete due to a weak violation of the adiabaticity, the CDM isocurvature
perturbations can be significantly suppressed, while non-Gaussianity of the
isocurvature perturbations generically remain unsuppressed. The isocurvature
bounds on the inflation scale can therefore be relaxed by the partial resonant
conversion of the QCD axions into hidden axions.",1411.2011v2
2014-11-14,Highly tunable ultra-narrow-resonances with optical nano-antenna phased arrays in the infrared,"We report our recent development in pursuing high Quality-Factor (high-Q
factor) plasmonic resonances, with vertically aligned two dimensional (2-D)
periodic nanorod arrays. The 2-D vertically aligned nano-antenna array can have
high-Q resonances varying arbitrarily from near infrared to terahertz regime,
as the antenna resonances of the nanorod are highly tunable through material
properties, the length of the nanorod, and the orthogonal polarization
direction with respect to the lattice surface,. The high-Q in combination with
the small optical mode volume gives a very high Purcell factor, which could
potentially be applied to various enhanced nonlinear photonics or
optoelectronic devices. The 'hot spots' around the nanorods can be easily
harvested as no index-matching is necessary. The resonances maintain their
high-Q factor with the change of the environmental refractive index, which is
of great interest for molecular sensing.",1411.3770v1
2014-11-24,"Resonances for the Laplacian on Riemannian symmetric spaces: the case of SL(3,$\mathbb{R}$)/SO(3)","We show that the resolvent of the Laplacian on SL(3,$\mathbb{R}$)/SO(3) can
be lifted to a meromorphic function on a Riemann surface which is a branched
covering of $\mathbb{C}$. The poles of this function are called the resonances
of the Laplacian. We determine all resonances and show that the corresponding
residue operators are given by convolution with spherical functions
parameterized by the resonances. The ranges of these operators are infinite
dimensional irreducible SL(3,$\mathbb{R}$)-representations. We determine their
Langlands parameters and wave front sets. Also, we show that precisely one of
these representations is unitarizable. Alternatively, they are given by the
differential equations which determine the image of the Poisson transform
associated with the resonance.",1411.6527v2
2014-11-25,On the collectivity of Pygmy Dipole Resonance within schematic TDA and RPA models,"Within schematic models based on the Tamm-Dancoff Approximation and the
Random-Phase Approximation with separable interactions, we investigate the
physical conditions which determine the emergence of the Pygmy Dipole Resonance
in the E1 response of atomic nuclei. We find that if some particle-hole
excitation manifests a different, weaker residual interaction, an additional
mode will appear, with an energy centroid closer to the distance between two
major shells and therefore well below the Giant Dipole Resonance. This state,
together with Giant Dipole Resonance, exhausts all the transition strength in
the Tamm-Dancoff Approximation and all the Energy Weighted Sum Rule in the
Random-Phase Approximation. Thus, within our scheme, this mode, which could be
associated with the Pygmy Dipole Resonance, is of collective nature. By
relating the coupling constants appearing in the separable interaction to the
symmetry energy value at and below saturation density we explore the role of
the density dependence of the symmetry energy on the low energy dipole
response.",1411.6965v2
2014-11-27,Interaction between dual cavity modes in a planar photonic microcavity,"We theoretically study the interaction between dual cavity modes in a planar
photonic microcavity structure in the optical communication wavelength range.
The merging and splitting of cavity mode is analyzed with realistic microcavity
structures. The merging of dual cavity resonance into a single cavity resonance
is achieved by changing the number of layers between the two cavities. The
splitting of single cavity resonance into dual cavity resonance is obtained
with an increase in the reflectivity of mirrors in the front and rear side of
the microcavity structure. The threshold condition for the merging and
splitting of cavity mode is established in terms of structural parameters. The
physical origin of the merging of dual cavity modes into a single cavity
resonance is discussed in terms of the electric field intensity distribution in
the microcavity structure. The microcavity structure with dual cavity modes is
useful for the generation of entangled photon pairs, for achieving the
strong-coupling regime between exciton and photon, and for high resolution
multi-wavelength filters in optical communication.",1411.7637v1
2014-12-01,Microwave pinning modes near Landau filling $ν=1$ in two-dimensional electron systems with alloy disorder,"We report measurements of microwave spectra of two-dimensional electron
systems hosted in dilute Al alloy, Al$_x$Ga$_{1-x}$As, for a range of Landau
level fillings, $\nu$, around 1. For $\nu>0.8$ or $\nu<1.2$, the samples
exhibit a microwave resonance whose frequency decreases as $\nu$ moves away
from 1. A resonance with this behavior is the signature of solids of
quasiparticles or -holes in the partially occupied Landau level, which was
previously seen in ultralow disorder samples. For $\nu<0.8$ down to as low as
$\nu=0.54$, a resonance in the spectra is still present in the Al
alloy-disordered samples, though it is partially or completely suppressed at
$\nu=3/5$ and $1/2$, and is strongly damped over much of this $\nu$ range. The
resonance also shows a striking enhancement in peak frequency for $\nu$ just
below 3/4. We discuss possible explanations of the resonance behavior for
$\nu<0.8$ in terms of the composite fermion picture.",1412.0689v1
2014-12-05,Resonant and non-resonant whistlers-particle interaction in the radiation belts,"We study the wave-particle interactions between lower band chorus whistlers
and an anisotropic tenuous population of relativistic electrons. We present the
first direct comparison of first-principle Particle-in-Cell (PIC) simulations
with a quasi-linear diffusion code, in this context. In the PIC approach, the
waves are self-consistently generated by a temperature anisotropy instability
that quickly saturates and relaxes the system towards marginal stability. We
show that the quasi-linear diffusion and PIC results have significant
quantitative mismatch in regions of energy/pitch angle where the resonance
condition is not satisfied. Moreover, for pitch angles close to the loss cone
the diffusion code overestimates the scattering, particularly at low energies.
This suggest that higher order nonlinear theories should be taken in
consideration in order to capture non-resonant interactions, resonance
broadening, and to account for scattering at angles close to $90^\circ$.",1412.2008v1
2014-12-09,Resonances in ultracold dipolar atomic and molecular gases,"A previously developed approach for the numerical treatment of two particles
that are confined in a finite optical-lattice potential and interact via an
arbitrary isotropic interaction potential has been extended to incorporate an
additional anisotropic dipole-dipole interaction. The interplay of a model but
realistic short-range Born-Oppenheimer potential and the dipole-dipole
interaction for two confined particles is investigated. A variation of the
strength of the dipole-dipole interaction leads to diverse resonance phenomena.
In a harmonic confinement potential some resonances show similarities to
$s$-wave scattering resonances while in an anharmonic trapping potential like
the one of an optical lattice inelastic confinement-induced dipolar resonances
occur. The latter are due to a coupling of the relative and center-of-mass
motion caused by the anharmonicity of the external confinement.",1412.3083v1
2014-12-11,Deviation From the Landau-Lifshitz-Gilbert equation in the Inertial regime of the Magnetization,"We investigate in details the inertial dynamics of a uniform magnetization in
the ferromagnetic resonance (FMR) context. Analytical predictions and numerical
simulations of the complete equations within the Inertial
Landau-Lifshitz-Gilbert (ILLG) model are presented. In addition to the usual
precession resonance, the inertial model gives a second resonance peak
associated to the nutation dynamics provided that the damping is not too large.
The analytical resolution of the equations of motion yields both the precession
and nutation angular frequencies. They are function of the inertial dynamics
characteristic time $\tau$, the dimensionless damping $\alpha$ and the static
magnetic field $H$. A scaling function with respect to $\alpha\tau\gamma H$ is
found for the nutation angular frequency, also valid for the precession angular
frequency when $\alpha\tau\gamma H\gg 1$. Beyond the direct measurement of the
nutation resonance peak, we show that the inertial dynamics of the
magnetization has measurable effects on both the width and the angular
frequency of the precession resonance peak when varying the applied static
field. These predictions could be used to experimentally identify the inertial
dynamics of the magnetization proposed in the ILLG model.",1412.3783v1
2014-12-17,Irreducible background and interference effects for Higgs-boson production in association with a top-quark pair,"We present an analysis of Higgs-boson production in association with a
top-quark pair at the LHC investigating in particular the final state
consisting of four b jets, two jets, one identified charged lepton and missing
energy. We consider the Standard Model prediction in three scenarios, the
resonant Higgs-boson plus top-quark-pair production, the resonant production of
a top-quark pair in association with a b-jet pair and the full process
including all non-resonant and interference contributions. By comparing these
scenarios we examine the irreducible background for the production rate and
several kinematical distributions. With standard selection criteria the
irreducible background turns out to be three times as large as the signal. For
most observables we find a uniform deviation of eight percent between the
scenario requiring two resonant top quarks and the full process. In particular
phase-space regions the non-resonant contributions cause larger effects, and we
observe shape changes for some distributions. Furthermore we investigate
interference effects and find that neglecting interference contributions
results in an over-estimate of the total cross-section of five percent.",1412.5290v1
2014-12-19,Analysis of plasmon resonance on smooth domains using spectral properties of the Neumann-Poincaré operators,"We investigate in a quantitative way the plasmon resonance at eigenvalues and
the essential spectrum (the accumulation point of eigenvalues) of the
Neumann-Poincar\'e operator on smooth domains. We first extend the
symmetrization principle so that the single layer potential becomes a unitary
operator from $H^{-1/2}$ onto $H^{1/2}$. We then show that the resonance at the
essential spectrum is weaker than that at eigenvalues. It is shown that
anomalous localized resonance occurs at the essential spectrum on ellipses, but
cloaking does not occur on ellipses unlike the core-shell structure considered
in [20]. It is shown that resonance does not occur at the essential spectrum on
three dimensional balls.",1412.6250v4
2015-01-06,Sensing magnetic nanoparticles using nano-confined ferromagnetic resonances in a magnonic crystal,"We demonstrate the use of the magnetic-field-dependence of highly spatially
confined, GHz-frequency ferromagnetic resonances in a ferromagnetic
nanostructure for the detection of adsorbed magnetic nanoparticles. This is
achieved in a large area magnonic crystal consisting of a thin ferromagnetic
film containing a periodic array of closely spaced, nano-scale anti-dots. Stray
fields from nanoparticles within the anti-dots modify resonant dynamic
magnetisation modes in the surrounding magnonic crystal, generating easily
measurable resonance peak shifts. The shifts are comparable to the resonance
linewidths for high anti-dot filling fractions with their signs and magnitudes
dependent upon the modes' localisations (in agreement with micromagnetic
simulation results). This is a highly encouraging result for the development of
frequency-based nanoparticle detectors for high speed nano-scale biosensing.",1501.01171v1
2015-01-08,Unitarity in composite Higgs approaches with vector resonances,"We examine a simple Composite Higgs Model (CHM) with vector resonances in
addition to the Standard Model (SM) fields in perturbation theory by using the
$K$-matrix method to implement unitarity constraints. We find that the $W_LW_L$
scattering amplitude has an additional scalar pole (analogous to the $\sigma$
meson of QCD) as in generic strongly interacting extensions of the SM. The mass
and width of this dynamically generated scalar resonance are large and the mass
behaves contrary to the vector one, so that when the vector resonance is
lighter, the scalar one is heavier, and vice versa. We also attempt an
interpretation of this new resonance. Altogether, the presence of the vector
state with the symmetries of the CHM improve the low-energy unitarity behavior
also in the scalar-isoscalar channel.",1501.01830v1
2015-01-10,Cascaded Brillouin lasing in monolithic barium fluoride whispering gallery mode resonators,"We report the observation of stimulated Brillouin scattering and lasing at
1550~nm in barium fluoride (BaF$_2$) crystal. Brillouin lasing was achieved
with ultra-high quality ($Q$) factor monolithic whispering gallery mode (WGM)
mm-size disk resonators. Overmoded resonators were specifically used to provide
cavity resonances for both the pump and all Brillouin Stokes waves. Single and
multiple Brillouin Stokes radiations with frequency shift ranging from $8.2$
GHz up to $49$ GHz have been generated through cascaded Brillouin lasing.
BaF$_2$ resonator-based Brillouin lasing can find potential applications for
high-coherence lasers and microwave photonics.",1501.02327v1
2015-01-12,On the 'Scattered' Inclinations in the Kuiper Belt,"This paper shows that the inclinations of bodies captured into mean motion
resonances in the Kuiper belt have remained very nearly unchanged, being only
slightly increased from initial lower values by migration and/or by long-term
planetary perturbations. Thus the observed maximum as high as ~ 30 deg of the
i's of bodies in resonance must reflect either a broad initial range at least
to that level for capturable bodies or an elevating process possibly
exemplified by the sweeping of secular resonances. We have obtained capture
probabilities for 2 well-populated resonances, showing reduced but finite
values for i's up to 35 deg. Whatever led to the present distribution must have
produced increases in i for some, but not for all, resonant bodies in the belt.",1501.02715v1
2015-01-30,Optical Feshbach resonances: Field-dressed theory and comparison with experiments,"Optical Feshbach resonances (OFRs) have generated significant experimental
interest in recent years. These resonances are promising for many-body physics
experiments, yet the practical application of OFRs has been limited. The theory
of OFRs has been based on an approximate model that fails in important detuning
regimes, and the incomplete theoretical understanding of this effect has
hindered OFR experiments. We present the most complete theoretical treatment of
OFRs to date, demonstrating important characteristics that must be considered
in OFR experiments and comparing OFRs to the well-studied case of magnetic
Feshbach resonances. We also present a comprehensive treatment of the
approximate OFR model, including a study of the range of validity for this
model. Finally, we derive experimentally useful expressions that can be applied
to real experimental data to extract important information about the resonance
structure of colliding atoms.",1502.00026v3
2015-02-05,Analysis of a Precambrian resonance-stabilized day length,"During the Precambrian era, Earth's decelerating rotation would have passed a
21-hour period that would have been resonant with the semidiurnal atmospheric
thermal tide. Near this point, the atmospheric torque would have been
maximized, being comparable in magnitude but opposite in direction to the lunar
torque, halting Earth's rotational deceleration, maintaining a constant day
length, as detailed by Zahnle and Walker (1987). We develop a computational
model to determine necessary conditions for formation and breakage of this
resonant effect. Our simulations show the resonance to be resilient to
atmospheric thermal noise but suggest a sudden atmospheric temperature increase
like the deglaciation period following a possible ""snowball Earth"" near the end
of the Precambrian would break this resonance; the Marinoan and Sturtian
glaciations seem the most likely candidates for this event. Our model provides
a simulated day length over time that resembles existing paleorotational data,
though further data is needed to verify this hypothesis.",1502.01421v3
2015-02-15,Experimental Observation of Resonance-Assisted Tunneling,"We present the first experimental observation of resonance-assisted
tunneling, a wave phenomenon, where regular-to-chaotic tunneling is strongly
enhanced by the presence of a classical nonlinear resonance chain. For this we
use a microwave cavity made of oxygen free copper with the shape of a
desymmetrized cosine billiard designed with a large nonlinear resonance chain
in the regular region. It is opened in a region, where only chaotic dynamics
takes place, such that the tunneling rate of a regular mode to the chaotic
region increases the line width of the mode. Resonance-assisted tunneling is
demonstrated by (i) a parametric variation and (ii) the characteristic plateau
and peak structure towards the semiclassical limit.",1502.04263v2
2015-02-17,Magnetic control of ultra-cold $^6$Li and $^{174}$Yb($^3P_2$) atom mixtures with Feshbach resonances,"We theoretically evaluate the feasibility to form magnetically-tunable
Feshbach molecules in collisions between fermionic $^6$Li atoms and bosonic
metastable $^{174}$Yb($^3$P$_2$) atoms. In contrast to the well-studied
alkali-metal atom collisions, collisions with meta-stable atoms are highly
anisotropic. Our first-principle coupled-channel calculation of these
collisions reveals the existence of broad Feshbach resonances due to the
combined effect of anisotropic-molecular and atomic-hyperfine interactions. In
order to fit our predictions to the specific positions of
experimentally-observed broad resonance structures \cite{Deep2015} we optimized
the shape of the short-range potentials by direct least-square fitting. This
allowed us to identify the dominant resonance by its leading angular momentum
quantum numbers and describe the role of collisional anisotropy in the creation
and broadening of this and other resonances.",1502.04973v1
2015-02-24,Selective excitations of a Kerr-nonlinear resonator: exactly solvable approach,"We study Kerr nonlinear resonators (KNR) driven by a continuous wave field in
quantum regimes where strong Kerr interactions give rise to selective resonant
excitations of oscillatory modes. We use an exact quantum theory of KNR in the
framework of the Fokker-Planck equation without any quantum state truncation or
perturbation procedure. This approach allows non-perturbative consideration of
KNR for various quantum operational regimes including cascaded processes
between oscillatory states. We focus on understanding of multi-photon
non-resonant and selective resonant excitations of introcavity mode depending
on the detuning, the amplitude of the driving field and the strength of
nonlinearity. The analysis is provided on the base of photon number
distributions, the photon-number correlation function and the Wigner function.",1502.06975v2
2015-02-26,Photoelectrical detection of electron spin resonance of nitrogen-vacancy centres in diamond,"The protocols for the control and readout of Nitrogen Vacancy (NV) centres
electron spins in diamond offer an advanced platform for quantum computation,
metrology and sensing. These protocols are based on the optical readout of
photons emitted from NV centres, which process is limited by the yield of
photons collection. Here we report on a novel principle for the detection of NV
centres magnetic resonance in diamond by directly monitoring spin-preserving
electron transitions through measurement of NV centre related photocurrent. The
demonstrated direct detection technique offers a sensitive way for the readout
of diamond NV sensors and diamond quantum devices on diamond chips. The
Photocurrent Detection of Magnetic Resonance (PDMR) scheme is based on the
detection of charge carriers promoted to the conduction band of diamond by the
two-photon ionization of NV- centres. Optical detection of magnetic resonance
(ODMR) and PDMR are compared, by performing both measurements simultaneously.
The minima detected in the measured photocurrent at resonant microwave
frequencies are attributed to the spin-dependent occupation probability of the
NV- ground state, originating from spin-selective non-radiative transitions.",1502.07551v1
2015-03-04,Laser induced Zero-Group Velocity resonances in Transversely Isotropic cylinder,"The transient response of an elastic cylinder to a laser impact is studied.
When the laser source is a line perpendicular to the cylinder axis, modes
guided along the cylinder are generated. For a millimetric steel cylinder up to
ten narrow resonances can be locally detected by laser interferometry below 8
MHz. Most of these resonances correspond to Zero-Group Velocity guided modes
while a few others can be ascribed to thickness modes. We observe that the
theory describing the propagation of elastic waves in an isotropic cylinder is
not sufficient to precisely predict the resonance spectrum. In fact, the
texture of such elongated structure manifest as elastic anisotropy. Thus, a
transverse isotropic (TI) model is used to calculate the dispersion curves and
compare them with the measured one, obtained by moving the source along the
cylinder. The five elastic constants of a TI cylinder are adjusted leading to a
good agreement between measured and theoretical dispersion curves. Then, all
the resonance frequencies are satisfactorily identified.",1503.01459v1
2015-03-05,Resonance broadening due to particle scattering and mode-coupling in the quasi-linear relaxation of electron beams,"Of particular interest for radio and hard X-ray diagnostics of accelerated
electrons during solar flares is the understanding of the basic non-linear
mechanisms regulating the relaxation of electron beams propagating in turbulent
plasmas. In this work, it is shown that in addition to scattering of beam
electrons, scattering of the beam-generated Langmuir waves via for instance
mode-coupling, can also result in broadening of the wave-particle resonance. We
obtain a resonance-broadened version of weak-turbulence theory with
mode-coupling to ion-sound modes. Resonance broadening is presented here as a
unified framework which can quantitatively account for the reduction and
possible suppression of the beam instability due to background scattering of
the beam electrons themselves or due to scattering of the beam-generated
Langmuir waves in fluctuating plasmas. Resonance broadening being essentially
equivalent to smoothing of the electron phase-space distribution, it is used to
construct an intuitive physical picture for the stability of inverted
populations of fast electrons that are commonly observed \emph{in-situ} to
propagate in the solar-wind.",1503.01710v1
2015-03-09,Quantum information processing on nitrogen-vacancy ensembles with the local resonance assisted by circuit QED,"With the local resonant interaction between a nitrogen-vacancy-center
ensemble (NVE) and a superconducting coplanar resonator, and the single-qubit
operation, we propose two protocols for the state transfer between two remote
NVEs and for fast controlled-phase (c-phase) on these NVEs, respectively. This
hybrid quantum system is composed of two distant NVEs coupled to separated
high-Q transmission line resonators (TLRs), which are interconnected by a
current-biased Josephsonjunction superconducting phase qubit. The fidelity of
our state-transfer protocol is about 99.65% within the operation time of 70.60
ns. The fidelity of our c-phase gate is about 98.23% within the operation time
of 93.87 ns. Furthermore, using the c-phase gate, we construct a
two-dimensional cluster state on NVEs in n*n square grid based on the hybrid
quantum system for the one-way quantum computation. Our protocol may be more
robust, compared with the one based on the superconducting resonators, due to
the long coherence time of NVEs at room temperature.",1503.02376v1
2015-03-09,Coherent Control of Resonant Two-Photon Transitions by Counter-Propagating Ultrashort Pulse Pairs,"We describe optimized coherent control methods for two-photon transitions in
atoms of a ladder-type three-state energy configuration. Our approach is based
on the spatial coherent control scheme which utilizes counter-propagating
ultrashort laser pulses to produce complex excitation patterns in an extended
space. Since coherent control requires constructive interference of constituent
transition pathways, applying it to an atomic transition with a specific energy
configuration requires specially designed laser pulses. Here, we show, in an
experimental demonstration, that the two-photon transition with an intermediate
resonant energy state can be coherently controlled and retrieved out from the
resonance-induced background, when phase-flipping of the laser spectrum near
the resonant intermediate transition is used. A simple reason for this behavior
is the fact that the transition amplitude function (to be added to give an
overall two-photon transition) changes its sign at the intermediate resonant
frequency, thus, by a proper spectral-phase programming, the excitation
patterns (or the position-dependent interference of the transition given as a
consequence of the spatial coherent control) are well isolated in space along
the focal region of the counter-propagating pulses.",1503.02378v2
2015-03-14,Spectrum of resonance states in $^6$He. Experimental and theoretical analysis,"We explore the structure of resonance states in $^{6}$He by experimental and
theoretical methods. We present the results of experimental investigations of
the three-body continuous spectrum of $^{6}$He. For this aim, we use the
reaction $^{3}$H$( \alpha,p\alpha)nn$, which is induced by the interaction of
alpha-particles with a triton at the beam energy $E_{\alpha} =$~67.2 MeV. The
theoretical analysis of the resonance structure in $^{6}$He is carried out
within the framework of a three-cluster microscopic model. The model exploits
the hyperspherical harmonics to describe the intercluster dynamics. The set of
new resonance states is discovered by the experimental and theoretical methods.
The energy, width, and dominant decay channels of resonances are determined.The
obtained results are compared in detail with the results of different
theoretical models and experiments as well.",1503.04308v1
2015-03-15,Schwinger-Keldysh canonical formalism for electronic Raman scattering,"Inelastic low-energy Raman and high-energy X-ray scatterings have made great
progress in instrumentation to investigate the strong electronic correlations
in matter. However, theoretical study of the relevant scattering spectrum is
still a challenge. In this article, we present a Schwinger-Keldysh canonical
perturbation formalism for the electronic Raman scattering, where all the
resonant, non-resonant and mixed responses are considered uniformly. We show
how to use this formalism to evaluate the cross section of the electronic Raman
scattering off an one-band superconductor. All the two-photon scattering
processes from electrons, the non-resonant charge density response, the elastic
Rayleigh scattering, the fluorescence, the intrinsic energy-shift Raman
scattering and the mixed response, are included. In the mean-field
superconducting state, Cooper pairs contribute only to the non-resonant
response. All the other responses are dominated by the single-particle
excitations and are strongly suppressed due to the opening of the
superconducting gap. Our formalism for the electronic Raman scattering can be
easily extended to study the high-energy resonant inelastic X-ray scattering.",1503.04441v2
2015-03-23,Resonance width distribution in RMT: Weak coupling regime beyond Porter-Thomas,"We employ the random matrix theory (RMT) framework to revisit the
distribution of resonance widths in quantum chaotic systems weakly coupled to
the continuum via a finite number M of open channels. In contrast to the
standard first-order perturbation theory treatment we do not a priory assume
the resonance widths being small compared to the mean level spacing. We show
that to the leading order in weak coupling the perturbative $\chi^2_M$
distribution of the resonance widths (in particular, the Porter-Thomas
distribution at M=1) should be corrected by a factor related to a certain
average of the ratio of square roots of the characteristic polynomial
(""spectral determinant"") of the underlying RMT Hamiltonian. A simple
single-channel expression is obtained that properly approximates the width
distribution also at large resonance overlap, where the Porter-Thomas result is
no longer applicable.",1503.06787v2
2015-03-24,Linear and nonlinear optics of hybrid plasmon-exciton nanomaterials in the presence of overlapping resonances,"We consider a hybrid plasmon-exciton system comprised of a resonant molecular
subsystem and three Au wires supporting a dipole mode which can be coupled to a
dark mode in controllable fashion by variation of a symmetry parameter. The
physics of such a system under strong coupling conditions is examined in
detail. It is shown that if two wires supporting the dark mode are covered with
molecular layers the system exhibits four resonant modes for a strong coupling
regime due to asymmetry and lifted degeneracy of the molecular state in this
case, while upon having molecular aggregates covering the top wire with dipolar
mode, three resonant modes appear. Pump-probe simulations are performed to
scrutinize the quantum dynamics and find possible ways to control
plasmon-exciton materials. It is demonstrated that one can design hybrid
nanomaterials with highly pronounced Fano-type resonances when excited by
femtosecond lasers.",1503.07115v1
2015-03-30,Statistics of Chaotic Resonances in an Optical Microcavity,"Distributions of eigenmodes are widely concerned in both bounded and open
systems. In the realm of chaos, counting resonances can characterize the
underlying dynamics (regular vs. chaotic), and is often instrumental to
identify classical-to-quantum correspondence. Here, we study, both
theoretically and experimentally, the statistics of chaotic resonances in an
optical microcavity with a mixed phase space of both regular and chaotic
dynamics. Information on the number of chaotic modes is extracted by counting
regular modes, which couple to the former via dynamical tunneling. The
experimental data are in agreement with a known semiclassical prediction for
the dependence of the number of chaotic resonances on the number of open
channels, while they deviate significantly from a purely
random-matrix-theory-based treatment, in general. We ascribe this result to the
ballistic decay of the rays, which occurs within Ehrenfest time, and
importantly, within the timescale of transient chaos. The present approach may
provide a general tool for the statistical analysis of chaotic resonances in
open systems.",1503.08654v2
2015-03-31,Dynamical Evolution of Multi-Resonant Systems: the Case of GJ876,"The GJ876 system was among the earliest multi-planetary detections outside of
the Solar System, and has long been known to harbor a resonant pair of giant
planets. Subsequent characterization of the system revealed the presence of an
additional Neptune mass object on an external orbit, locked in a three body
Laplace mean motion resonance with the previously known planets. While this
system is currently the only known extrasolar example of a Laplace resonance,
it differs from the Galilean satellites in that the orbital motion of the
planets is known to be chaotic. In this work, we present a simple perturbative
model that illuminates the origins of stochasticity inherent to this system and
derive analytic estimates of the Lyapunov time as well as the chaotic diffusion
coefficient. We then address the formation of the multi-resonant structure
within a protoplanetary disk and show that modest turbulent forcing in addition
to dissipative effects is required to reproduce the observed chaotic
configuration. Accordingly, this work places important constraints on the
typical formation environments of planetary systems and informs the attributes
of representative orbital architectures that arise from extended disk-driven
evolution.",1504.00051v1
2015-04-02,Identification of Resonant States via the Generalized Virial Theorem,"The numerical extraction of resonant states of open quantum systems is
usually a difficult problem. Regularization techniques, such as the mapping to
complex coordinates or the addition of Complex Absorbing Potentials are
typically employed, as they render resonant wavefunctions localized and
therefore normalizable. Physically relevant metastable states have energies
that do not depend on the chosen regularization method. Their identification
therefore involves cumbersome comparisons between multiple regularised
calculations, often performed graphically, which require fine-tuning and
specific intuition to avoid approximated, if not wrong, results. In this
Letter, we define an operator that explicitly measures such invariance, valid
for any arbitrary mapping of spatial coordinates. Resonant states of the system
can eventually simply be identified evaluating the expectation value of this
operator. Our method eases the extraction of resonant states even for numerical
potentials that are difficult to scale to complex coordinates, and avoids the
need for ad hoc complex absorbing potentials. We provide explicit evidence of
our findings discussing one-dimensional case-studies,also in the presence of
external electric fields.",1504.00536v1
2015-04-04,Leaky modes of waveguides as a classical optics analogy of quantum resonances,"A classical optics waveguide structure is proposed to simulate resonances of
short range one-dimensional potentials in quantum mechanics. The analogy is
based on the well known resemblance between the guided and radiation modes of a
waveguide with the bound and scattering states of a quantum well. As resonances
are scattering states that spend some time in the zone of influence of the
scatterer, we associate them with the leaky modes of a waveguide, the latter
characterized by suffering attenuation in the direction of propagation but
increasing exponentially in the transverse directions. The resemblance is
complete since resonances (leaky modes) can be interpreted as bound states
(guided modes) with definite lifetime (longitudinal shift). As an immediate
application we calculate the leaky modes (resonances) associated with a
dielectric homogeneous slab (square well potential) and show that these modes
are attenuated as they propagate.",1504.01008v2
2015-04-04,Black Phosphorus Nanoelectromechanical Resonators Vibrating at Very High Frequencies,"We report on experimental demonstration of a new type of
nanoelectromechanical resonators based on black phosphorus crystals.
Facilitated by a highly efficient dry transfer technique, crystalline black
phosphorus flakes are harnessed to enable drumhead resonators vibrating at high
and very high frequencies (HF and VHF bands, up to ~100MHz). We investigate the
resonant vibrational responses from the black phosphorus crystals by devising
both electrical and optical excitation schemes, in addition to measuring the
undriven thermomechanical motions in these suspended nanostructures. Flakes
with thicknesses from ~200nm down to ~20nm clearly exhibit elastic
characteristics transitioning from the plate to the membrane regime. Both
frequency- and time-domain measurements of the nanomechanical resonances show
that very thin black phosphorus crystals hold interesting promises for moveable
and vibratory devices, and for semiconductor transducers where high-speed
mechanical motions could be coupled to the attractive electronic and
optoelectronic properties of black phosphorus.",1504.01058v1
2015-04-15,Resonant scattering by magnetic impurities as a model for spin relaxation in bilayer graphene,"We propose that the observed spin-relaxation in bilayer graphene is due to
resonant scattering by magnetic impurities. We analyze a resonant scattering
model due to adatoms on both dimer and non-dimer sites, finding that only the
former give narrow resonances at the charge neutrality point. Opposite to
single-layer graphene, the measured spin-relaxation rate in graphene bilayer
increases with carrier density. Although it has been commonly argued that a
different mechanism must be at play for the two structures, our model explains
this behavior rather naturally in terms of different broadening scales for the
same underlying resonant processes. Not only our results---using robust and
first-principles inspired parameters---agree with experiment, they also predict
an experimentally testable sharp decrease of the spin-relaxation rate at high
carrier densities.",1504.03898v2
2015-04-16,Phase motion in the $Z^-(4430)$ amplitude in $B^0\toψ^\primeπ^-K^+$ decay,"In view of the proliferation in the number of new charmonium states, it is
really important to have a experimental way to prove that an observed bump is,
indeed, a real resonance. To do that, in this paper we present an alternative
method to demonstrate the resonant behavior of a state. With this method, the
phase variation of a generic complex amplitude can be directly revealed through
interference in the Dalitz-plot region where it crosses a well established
resonant state, used as a probe. We have tested the method for the $Z^-(4430)$
state by generating Monte Carlo samples for the $B^0\to \psi^\prime \pi^-K^+$
decay channel. We have shown that the proposed method gives a clear oscillation
behavior, related to the phase variation associated to a real resonant state,
in the case where the $Z^-(4430)$ is considered as a regular resonance with a
strong phase variation. We have also discussed the possibility of using the
proposed method complementary to the Argand diagram to determine the internal
structure of the $Z^-(4430)$ state.",1504.04313v1
2015-05-13,Improved mirror position estimation using resonant quantum smoothing,"Quantum parameter estimation, the ability to precisely obtain a classical
value in a quantum system, is very important to many key quantum technologies.
Many of these technologies rely on an optical probe, either coherent or
squeezed states to make a precise measurement of a parameter ultimately limited
by quantum mechanics. We use this technique to theoretically model, simulate
and validate by experiment the measurement and precise estimation of the
position of a cavity mirror. In non-resonant systems, the achieved estimation
enhancement from quantum smoothing over optimal filtering has not exceeded a
factor two, even when squeezed state probes were used. Using a coherent state
probe, we show that using quantum smoothing on a mechanically resonant
structure driven by a resonant forcing function can result significantly
greater improvement in parameter estimation than with non-resonant systems. In
this work, we show that it is possible to achieve a smoothing improvement by a
factor in excess of three times over optimal filtering. By using intra-cavity
light as the probe we obtain finer precision than has been achieved with the
equivalent quantum resources in free-space.",1505.03301v1
2015-05-13,Cross-Phase Modulation Enhancement Via a Resonating Cavity: Semiclassical Description,"We evaluate the advantages of performing cross-phase modulation (XPM) on a
very-far-off-resonance atomic system. We consider a ladder system with a weak
(few-photon level) control coherent field imparting a conditional nonlinear
phase shift on a probe beam. We find that by coupling to an optical resonator
the optimal XPM is enhanced proportional to the finesse of the resonator by a
factor of $F/4\pi$. We present a semi-classical description of the system and
show that the phenomenon is optimal in the self-defined condition of
off-resonance-effective-cooperativity equal to one.",1505.03423v3
2015-05-14,A Self-Assembled Metamaterial for Lamb Waves,"We report the design and characterization of a self-assembled, locally
resonant acoustic metamaterial for Lamb waves, composed of a monolayer of
$1.02$ $\mu$m polystyrene microspheres adhered to a $1.3$ $\mu$m thick
free-standing silicon membrane. A laser-induced transient grating technique is
used to generate Lamb waves in the metamaterial and measure its acoustic
response. The measurements reveal a microsphere contact resonance and the
lowest frequency spheroidal microsphere resonance. The measured dispersion
curves show hybridization of flexural Lamb waves with the microsphere contact
resonance. We compare the measured dispersion with an analytical model using
the contact resonance frequency as a single fitting parameter, and find that it
well describes the observed hybridization. Results from this study can lead to
an improved understanding of microscale contact mechanics and to the design of
new types of acoustic metamaterials.",1505.03777v2
2015-05-18,Black holes with a single Killing vector field: black resonators,"We numerically construct asymptotically anti-de Sitter (AdS) black holes in
four dimensions that contain only a single Killing vector field. These
solutions, which we coin black resonators, link the superradiant instability of
Kerr-AdS to the nonlinear weakly turbulent instability of AdS by connecting the
onset of the superradiance instability to smooth, horizonless geometries called
geons. Furthermore, they demonstrate non-uniqueness of Kerr-AdS by sharing
asymptotic charges. Where black resonators coexist with Kerr-AdS, we find that
the black resonators have higher entropy. Nevertheless, we show that black
resonators are unstable and comment on the implications for the endpoint of the
superradiant instability.",1505.04793v1
2015-05-27,Imaging instantaneous electron flow with ultrafast resonant x-ray scattering,"We propose a novel way to image dynamical properties of nonstationary
electron systems using ultrafast resonant x-ray scattering. Employing a
rigorous theoretical analysis within the framework of quantum electrodynamics,
we demonstrate that a single scattering pattern from a nonstationary electron
system encodes the instantaneous interatomic electron current in addition to
the structural information usually obtained by resonant x-ray scattering from
stationary systems. Thus, inelastic contributions that are indistinguishable
from elastic processes induced by a broadband probe pulse, instead of being a
concern, serve as an advantage for time-resolved resonant x-ray scattering.
Thereby, we propose an approach combining elastic and inelastic resonant x-ray
scattering for imaging dynamics of nonstationary electron systems in both real
space and real time. In order to illustrate its power, we show how it can be
applied to image the electron hole current in an ionized diatomic molecule.",1505.07452v1
2015-06-03,Resonant transport and electrostatic effects in single-molecule electrical junctions,"In this contribution we demonstrate structural control over a transport
resonance in HS(CH$_{2}$)$_{n}$[1,4 - C$_{6}$H$_{4}$](CH$_{2}$)$_{n}$SH (n = 1,
3, 4, 6) metal - molecule - metal junctions, fabricated and tested using the
scanning tunnelling microscopy-based $I(z)$ method. The Breit-Wigner resonance
originates from one of the arene $\pi$-bonding orbitals, which sharpens and
moves closer to the contact Fermi energy as $n$ increases. Varying the number
of methylene groups thus leads to a very shallow decay of the conductance with
the length of the molecule. We demonstrate that the electrical behaviour
observed here can be straightforwardly rationalized by analyzing the effects
caused by the electrostatic balance created at the metal-molecule interface.
Such resonances offer future prospects in molecular electronics in terms of
controlling charge transport over longer distances, and also in single molecule
conductance switching if the resonances can be externally gated.",1506.01304v1
2015-06-05,Broad universal Feshbach resonances in the chaotic spectrum of Dysprosium atoms,"We report on the observation of weakly-bound dimers of bosonic Dysprosium
with a strong universal s-wave halo character, associated with broad magnetic
Feshbach resonances. These states surprisingly decouple from the chaotic
backgound of narrow resonances, persisting across many such narrow resonances.
In addition they show the highest reported magnetic moment
$\mu\simeq20\,\mu_{\rm B}$ of any ultracold molecule. We analyze our findings
using a coupled-channel theory taking into account the short range van der
Waals interaction and a correction due to the strong dipole moment of
Dysprosium. We are able to extract the scattering length as a function of
magnetic field associated with these resonances and obtain a background
scattering length $a_{\rm bg}=91(16)\,a_0$. These results offer prospects of a
tunability of the interactions in Dysprosium, which we illustrate by observing
the saturation of three-body losses.",1506.01875v2
2015-06-08,Coulomb pairing resonances in multiple-ring aromatic molecules,"We present an analysis of the pairing resonances observed in
photo-double-ionization studies of CnHm aromatic molecules with multiple
benzene-like rings. The analysis, which is based on the Coulomb pairing model,
is applied to naphthalene, anthracene, phenanthrene, pyrene and coronene, all
of which have six-member rings, and azulene which is comprised of a five-member
and a seven-member ring. There is a high energy resonance at ~ 40 eV that is
found in all of the molecules cited and is associated with paired electrons
localized on carbon sites on the perimeter of the molecule, each of which
having two carbon sites as nearest neighbors. The low energy resonance at 10
eV, which is found only in pyrene and coronene, is attributed to the formation
of paired electrons localized on arrays of interior carbon atoms that have the
point symmetry of the molecule with each carbon atom having three nearest
neighbors. The origin of the anomalous increase in the doubly charged to singly
charged parent-ion ratio that is found above the 40 eV resonance in all of the
cited molecules except coronene is discussed.",1506.02634v2
2015-06-21,Chaotic scattering in the presence of a dense set of overlapping Feshbach resonances,"Complex quantum systems consisting of large numbers of strongly coupled
states exhibit characteristic level repulsion, leading to a non-Poisson spacing
distribution which can be described by Random Matrix Theory. Scattering
resonances observed in ultracold atomic and molecular systems exhibit similar
features as a consequence of their energy level structure. We study how the
overlap between Feshbach resonances affects the distribution of resonance
spacings. The spectrum of strongly overlapping resonances turns out to be
non-Poisson even when the assumptions of Random Matrix Theory are not
fulfilled, but the spectrum is also not completely chaotic and tends towards
being semi-Poisson.",1506.06347v2
2015-06-29,"Sub-cycle ionization dynamics revealed by trajectory resolved, elliptically-driven high-order harmonic generation","The sub-cycle dynamics of electrons driven by strong laser fields is central
to the emerging field of attosecond science. We demonstrate how the dynamics
can be probed through high-order harmonic generation, where different
trajectories leading to the same harmonic order are initiated at different
times, thereby probing different field strengths. We find large differences
between the trajectories with respect to both their sensitivity to driving
field ellipticity and resonant enhancement. To accurately describe the
ellipticity dependence of the long trajectory harmonics we must include a
sub-cycle change of the initial velocity distribution of the electron and its
excursion time. The resonant enhancement is observed only for the long
trajectory contribution of a particular harmonic when a window resonance in
argon, which is off-resonant in the field-free case, is shifted into resonance
due to a large dynamic Stark shift.",1506.08660v2
2015-07-01,Efficient generation of NOON states on two microwave-photon resonators,"We present an efficient scheme for the generation of NOON states of photons
in circuit QED assisted by a superconducting charge qutrit. It is completed
with two kinds of manipulations, that is, the resonant operation on the qutrit
and the resonator, and the single-qubit operation on the qutrit, and they both
are high-fidelity operations. Compared with the one by a superconducting
transmon qutrit proposed by Su et al. (Sci. Rep. 4, 3898 (2014)), our scheme
does not require to maintain the qutrit in the third excited state with a long
time, which relaxes the difficulty of its implementation in experiment.
Moreover, the level anharmonicity of a charge qutrit is larger and it is better
for us to tune the different transitions of the charge qutrit resonant to the
resonator, which makes our scheme faster than others.",1507.00074v1
2015-07-10,Resonance Condition and Low Frequency Quasi Periodic Oscillations of the Outbursting Source H 1743-322,"It has long been proposed that low frequency QPOs in stellar mass black holes
or their equivalents in super massive black holes are results of resonances
between infall and cooling time scales. We explicitly compute these two time
scales in a generic situation to show that resonances are easily achieved.
During an outburst of a transient black hole candidate (BHC), the accretion
rate of the Keplerian disk as well as the geometry of the Comptonizing cloud
change very rapidly. During some period, resonance condition between the
cooling time scale (predominantly by Comptonization) and the infall time scale
of the Comptonizing cloud is roughly satisfied. This leads to low frequency
quasi-periodic oscillations (LFQPOs) of the Compton cloud and the consequent
oscillation of hard X-rays. In this paper, we explicitly follow the BHC H
1743-322 during its 2010 outburst. We compute Compton cooling time and infall
time on several days and show that QPOs take place when these two roughly agree
within ~50%, i.e., the resonance condition is generally satisfied. We also
confirm that for the sharper LFQPOs (i.e., higher Q-factors) the ratio of two
time scales is very close to 1.",1507.02831v1
2015-07-16,Radiation Reaction Effect on Laser Driven Auto-Resonant Particle Acceleration,"The effects of radiation reaction force on laser driven auto-resonant
particle acceleration scheme are studied using Landau-Lifshitz equation of
motion. These studies are carried out for both linear as well as circularly
polarized laser fields in the presence of static axial magnetic field. From the
parametric study, a radiation reaction dominated region has been identified in
which the particle dynamics is greatly effected by this force. In the radiation
reaction dominated region the two significant effects on particle dynamics are
seen viz., (1) saturation in energy gain by the initially resonant particle,
(2) net energy gain by a initially non-resonant particle which is caused due to
resonance broadening. It has been further shown that with the optimum choice of
parameters this scheme can be efficiently used to produce electrons with
energies in the range of hundreds of TeV. The quantum corrections to the
Landu-Lifshitz equation of motion have also been taken into account. The
difference in the energy gain estimates of the particle by the quantum
corrected and classical Landu-Lifshitz equation are found to be insignificant
for the present day as well as upcoming laser facilities.",1507.04446v1
2015-07-27,Electron spin resonance in a model S=1/2 chain antiferromagnet with a uniform Dzyaloshinskii--Moriya interaction,"The electron spin resonance spectrum of a quasi 1D S=1/2 antiferromagnet
K2CuSO4Br2 was found to demonstrate an energy gap and a doublet of resonance
lines in a wide temperature range between the Curie--Weiss and Ne\`{e}l
temperatures. This type of magnetic resonance absorption corresponds well to
the two-spinon continuum of excitations in S=1/2 antiferromagnetic spin chain
with a uniform Dzyaloshinskii--Moriya interaction between the magnetic ions. A
resonance mode of paramagnetic defects demonstrating strongly anisotropic
behavior due to interaction with spinon excitations in the main matrix is also
observed.",1507.07518v1
2015-07-27,Composite spin-1 resonances at the LHC,"In this paper, we discuss the signal of composite spin-1 resonances at the
LHC. Motivated by the possible observation of a diboson resonance in the 8 TeV
LHC data, we demonstrate that vector resonances from composite Higgs models are
able to describe the data. We pay particular attention to the role played by
fermion partial compositeness, which is a common feature in composite Higgs
models. The parameter space that is both able to account for the diboson excess
and passes electroweak precision and flavor tests is explored. Finally, we make
projections for signals of such resonances at the 13 TeV run of the LHC.",1507.07557v3
2015-08-01,One-step implementation of entanglement generation on microwave photons in distant 1D superconducting resonators,"We present a scalable quantum-bus-based device for generating the
entanglement on microwave photons (MPs) in distant superconducting resonators
(SRs). Different from the processors in previous works with some resonators
coupled to a superconducting qubit (SQ), our device is composed of some 1D SRs
$r_j$ which are coupled to the quantum bus (another common resonator $R$) in
its different positions simply, assisted by superconducting quantum
interferometer devices. By using the technique for catching and releasing a MP
state in a 1D SR, it can work as an entanglement generator or a node in quantum
communication. To demonstrate the performance of this device, we propose a
one-step scheme to generate high-fidelity Bell states on MPs in two distant
SRs. It works in the dispersive regime of $r_j$ and $R$, which enables us to
extend it to generate high-fidelity multi-Bell states on different resonator
pairs simultaneously.",1508.00061v1
2015-08-10,Tunable multiple Fano resonances in magnetic single-layered core-shell particles,"We investigate multiple Fano, comblike scattering resonances in
single-layered, concentric core-shell nanoparticles composed of magnetic
materials. Using the Lorenz-Mie theory, we derive, in the long-wavelength
limit, an analytical condition for the occurrence of comblike resonances in the
single scattering by coated spheres. This condition establishes that comblike
scattering response uniquely depends on material parameters and thickness of
the shell, provided that it is magnetic and thin compared to the scatterer
radius. We also demonstrate that comblike scattering response shows up beyond
the long-wavelength limit and it is robust against absorption. Since multiple
Fano resonances are shown to depend explicitly on the magnetic permeability of
the shell, we argue that both the position and profile of the comblike,
morphology-dependent resonances could be externally tuned by exploiting the
properties of engineered magnetic materials.",1508.02255v1
2015-08-18,Negative nonlinear damping of a graphene mechanical resonator,"We experimentally investigate the nonlinear response of a multilayer graphene
resonator using a superconducting microwave cavity to detect its motion. The
radiation pressure force is used to drive the mechanical resonator in an
optomechanically induced transparency configuration. By varying the amplitudes
of drive and probe tones, the mechanical resonator can be brought into a
nonlinear limit. Using the calibration of the optomechanical coupling, we
quantify the mechanical Duffing nonlinearity. By increasing the drive force, we
observe a decrease in the mechanical dissipation rate at large amplitudes,
suggesting a negative nonlinear damping mechanism in the graphene resonator.
Increasing the optomechanical backaction, we observe a nonlinear regime not
described by a Duffing response that includes new instabilities of the
mechanical response.",1508.04298v1
2015-08-21,Inhomogeneous nuclear spin polarization induced by helicity-modulated optical excitation of fluorine-bound electron spins in ZnSe,"Optically-induced nuclear spin polarization in a fluorine-doped ZnSe epilayer
is studied by time-resolved Kerr rotation using resonant excitation of
donor-bound excitons. Excitation with helicity-modulated laser pulses results
in a transverse nuclear spin polarization, which is detected as a change of the
Larmor precession frequency of the donor-bound electron spins. The frequency
shift in dependence on the transverse magnetic field exhibits a pronounced
dispersion-like shape with resonances at the fields of nuclear magnetic
resonance of the constituent zinc and selenium isotopes. It is studied as a
function of external parameters, particularly of constant and radio frequency
external magnetic fields. The width of the resonance and its shape indicate a
strong spatial inhomogeneity of the nuclear spin polarization in the vicinity
of a fluorine donor. A mechanism of optically-induced nuclear spin polarization
is suggested based on the concept of resonant nuclear spin cooling driven by
the inhomogeneous Knight field of the donor-bound electron.",1508.05295v1
2015-09-01,Describing 2-TeV scale W_L W_L resonances with Unitarized Effective Theory,"The LHC is now exploring the 1-3 TeV scale where resonances of the
Electroweak Symmetry Breaking Sector might exist. If so, Unitarized Effective
Theory can be used to describe the data with all the constraints of unitarity,
causality and global-symmetry breaking, and to find the resonance positions in
the complex s-plane. From any resonances found, one can infer the parameters of
the universal Effective Lagrangian, and those may be used to inform
higher-energy theories (UV completions) that can be matched to it. We exemplify
with two-body resonances in the coupled channels hh and W_L W_L- Z_L Z_L
employing the Equivalence Theorem and comment on the apparent excess in the
ATLAS dijet data at 2 TeV.",1509.00441v1
2015-09-03,Inelastic Confinement-Induced Resonances in Quantum Dots,"Recently, it was shown that the coupling of center-of-mass and relative
motion in atomic systems leads to inelastic confinement-induced resonances
(ICIRs) [Phys. Rev. Lett. 109, 073201 (2012)]. In the present work, the
possible occurrence of ICIRs in quantum dots is investigated. Particularly,
electron-hole and electron-electron two-body systems with long-range Coulomb
interaction are considered using the material parameters of GaAs. ICIRs are
identified for the electron-hole system verifying the universal nature of the
ICIR and, additionally, resonances due to the coupling of center-of-mass and
relative motion are found also for the electron-electron system. In analogy to
the coherent molecule formation appearing at ICIR in atomic systems a
significant change in the mean distance between electrons and holes at the
resonance is observed. By using the redistribution of the particle densities at
the resonance position in modern quantum-dot experiments, the ICIR can provide
a new technique for the control of the electron distribution in quantum dots
and for the generation of single photons on demand.",1509.01159v1
2015-09-11,The Resonance Overlap and Hill Stability Criteria Revisited,"We review the orbital stability of the planar circular restricted three-body
problem, in the case of massless particles initially located between both
massive bodies. We present new estimates of the resonance overlap criterion and
the Hill stability limit, and compare their predictions with detailed dynamical
maps constructed with N-body simulations. We show that the boundary between
(Hill) stable and unstable orbits is not smooth but characterized by a rich
structure generated by the superposition of different mean-motion resonances
which does not allow for a simple global expression for stability.
  We propose that, for a given perturbing mass $m_1$ and initial eccentricity
$e$, there are actually two critical values of the semimajor axis. All values
$a < a_{\rm Hill}$ are Hill-stable, while all values $a > a_{\rm unstable}$ are
unstable in the Hill sense. The first limit is given by the Hill-stability
criterion and is a function of the eccentricity. The second limit is virtually
insensitive to the initial eccentricity, and closely resembles a new resonance
overlap condition (for circular orbits) developed in terms of the intersection
between first and second-order mean-motion resonances.",1509.03607v1
2015-09-12,Subwavelength total acoustic absorption with degenerate resonators,"We report the experimental realization of perfect sound absorption by
sub-wavelength monopole and dipole resonators that exhibit degenerate resonant
frequencies. This is achieved through the destructive interference of two
resonators' transmission responses, while the matching of their averaged
impedances to that of air implies no backscattering, thereby leading to total
absorption. Two examples, both using decorated membrane resonators (DMRs) as
the basic units, are presented. The first is a flat panel comprising a DMR and
a pair of coupled DMRs, while the second one is a ventilated short tube
containing a DMR in conjunction with a sidewall DMR backed by a cavity. In both
examples, near perfect absorption, up to 99.7%, has been observed with the
airborne wavelength up to 1.2 m, which is at least an order of magnitude larger
than the composite absorber. Excellent agreement between theory and experiment
is obtained.",1509.03711v1
2015-10-01,Nested Trampoline Resonators for Optomechanics,"Two major challenges in the development of optomechanical devices are
achieving a low mechanical and optical loss rate and vibration isolation from
the environment. We address both issues by fabricating trampoline resonators
made from low pressure chemical vapor deposition (LPCVD) Si$_3$N$_4$ with a
distributed bragg reflector (DBR) mirror. We design a nested double resonator
structure with 80 dB of mechanical isolation from the mounting surface at the
inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower
frequencies in agreement with the design. We reliably fabricate devices with
mechanical quality factors of around 400,000 at room temperature. In addition
these devices were used to form optical cavities with finesse up to 181,000
$\pm$ 1,000. These promising parameters will enable experiments in the quantum
regime with macroscopic mechanical resonators.",1510.00206v2
2015-10-04,Unquenched quark-model calculation of excited $ρ$ resonances and P-wave $ππ$ phase shifts,"The $\rho(770)$ vector resonance, its radial recurrences, and the
corresponding P-wave $\pi\pi$ phase shifts are investigated in an unquenched
quark model with all classes of relevant decay channels included, viz.
pseudoscalar-pseudoscalar, vector-pseudoscalar, vector-vector, vector-scalar,
axialvector-pseudoscalar, and axialvector-vector, totalling 26 channels. Two of
the few model parameters are fixed at previously used values, whereas the other
three are adjusted to the $\rho(770)$ resonance and the lower P-wave $\pi\pi$
phases. Preliminary results indicate the model's capacity to reproduce these
phases as well as the $\rho$ mass and width. However, at higher energies the
phase shifts tend to rise too sharply. A possible remedy is an extension of the
model so as to handle resonances in the final states for most of the included
decay channels. Work in progress.",1510.00938v1
2015-10-09,Single-electron Spin Resonance in a Quadruple Quantum Dot,"Electron spins in semiconductor quantum dots are good candidates of quantum
bits for quantum information processing. Basic operations of the qubit have
been realized in recent years: initialization, manipulation of single spins,
two qubit entanglement operations, and readout. Now it becomes crucial to
demonstrate scalability of this architecture by conducting spin operations on a
scaled up system. Here, we demonstrate single-electron spin resonance in a
quadruple quantum dot. A few-electron quadruple quantum dot is formed within a
magnetic field gradient created by a micro-magnet. We oscillate the wave
functions of the electrons in the quantum dots by applying microwave voltages
and this induces electron spin resonance. The resonance energies of the four
quantum dots are slightly different because of the stray field created by the
micro-magnet and therefore frequency-resolved addressable control of the
electron spin resonance is possible.",1510.02547v1
2015-10-13,Comparing mesons and W_L W_L TeV-resonances,"Tantalizing LHC hints suggest that resonances of the Electroweak Symmetry
Breaking Sector might exist at the TeV scale. We recall a few key meson-meson
resonances in the GeV region that could have high-energy analogues which we
compare, as well as the corresponding unitarized effective theories describing
them. While detailed dynamics may be different, the constraints of unitarity,
causality and global-symmetry breaking, incorporated in the Inverse Amplitude
Method, allow to carry some intuition over to the largely unmeasured higher
energy domain. If the 2 TeV ATLAS excess advances one such new resonance, this
could indicate an anomalous q qbar W coupling.",1510.03761v1
2015-10-13,Induced two-body scattering resonances from a square-well potential with oscillating depth,"In systems of ultracold atoms, pairwise interactions can be resonantly
enhanced by a new mechanism which does not rely upon a magnetic Feshbach
resonance. In this mechanism, interactions are controlled by tuning the
frequency of an oscillating parallel component of the magnetic field close to
the Bohr frequency for the transition to a two-atom bound state. The real part
of the s-wave scattering length $a$ has a resonance as a function of the
oscillation frequency near the Bohr frequency. The resonance parameters can be
controlled by varying the amplitude of the oscillating field. The amplitude
also controls the imaginary part of $a$ which arises predominantly because the
oscillating field converts atom pairs into molecules. For the case of a shallow
bound state in the scattering channel, the dimensionless resonance parameters
are universal functions of the dimensionless oscillation amplitude.",1510.03809v1
2015-10-16,Randomized benchmarking of quantum gates implemented by electron spin resonance,"Spin systems controlled and probed by magnetic resonance have been valuable
for testing the ideas of quantum control and quantum error correction. This
paper introduces an X-band pulsed electron spin resonance spectrometer designed
for high-fidelity coherent control of electron spins, including a loop-gap
resonator for sub-millimeter sized samples with a control bandwidth ~ 40 MHz.
Universal control is achieved by a single-sideband upconversion technique with
an I-Q modulator and a 1.2 GS/s arbitrary waveform generator. A single qubit
randomized benchmarking protocol quantifies the average errors of Clifford
gates implemented by simple Gaussian pulses, using a sample of gamma-irradiated
quartz. Improvements in unitary gate fidelity are achieved through phase
transient correction and hardware optimization. A preparation pulse sequence
that selects spin packets in a narrowed distribution of static fields confirms
that inhomogeneous dephasing (1/T2*) is the dominant source of gate error. The
best average fidelity over the Clifford gates obtained here is 99.2%, which
serves as a benchmark to compare with other technologies.",1510.04779v3
2015-10-19,A normal form for 1-infinite type hypersurfaces in $\mathbb C^2$. I. Formal Theory,"In this paper, we study the real hypersurfaces $M$ in $\mathbb C^2$ at points
$p\in M$ of infinite type. The degeneracy of $M$ at $p$ is assumed to be the
least possible, namely such that the Levi form vanishes to first order in the
CR transversal direction. A new phenomenon, compared to known normal forms in
other cases, is the presence of resonances as roots of an universal polynomial
in the $7$-jet of the defining function of $M$. The main result is a complete
(formal) normal form at points $p$ with no resonances. Remarkably, our normal
form at such infinite type points resembles closely the Chern-Moser normal form
at Levi-nondegenerate points. For a fixed hypersurface, its normal forms are
parametrized by $S^1\times \mathbb R^*$, and as a corollary we find that the
automorphisms in the stability group of $M$ at $p$ without resonances are
determined by their $1$-jets at $p$. In the last section, as a contrast, we
also give examples of hypersurfaces with arbitrarily high resonances that
possess families of distinct automorphisms whose jets agree up to the resonant
order.",1510.05335v2
2015-10-20,Complex contact-based dynamics of microsphere monolayers revealed by resonant attenuation of surface acoustic waves,"Contact-based vibrations play a critical role in the dynamics of granular
materials. Significant insights into vibrational granular dynamics have been
obtained with reduced-dimensional systems containing macroscale particles. We
study contact-based vibrations of a two-dimensional monolayer of micron-sized
spheres on a solid substrate. Measurements of the resonant attenuation of
laser-generated surface acoustic waves reveal three collective vibrational
modes involving both displacements and rotations of the microspheres. To
identify the modes, we tune the interparticle stiffness, which shifts the
frequency of the horizontal-rotational resonances while leaving the vertical
resonance unaffected. From the measured contact resonance frequencies we
determine both particle-substrate and interparticle contact stiffnesses and
find that the former is an order of magnitude larger than the latter. This
study paves the way for investigating complex contact-based dynamics of
microgranular media, demonstrates a novel acoustic metamaterial, and yields a
new approach to studying micro- to nanoscale contact mechanics in multiparticle
networks.",1510.05975v1
2015-10-26,Frequency Precision of Oscillators Based on High-Q Resonators,"We present a method for analyzing the phase noise of oscillators based on
feedback driven high quality factor resonators. Our approach is to derive the
phase drift of the oscillator by projecting the stochastic oscillator dynamics
onto a slow time scale corresponding physically to the long relaxation time of
the resonator. We derive general expressions for the phase drift generated by
noise sources in the electronic feedback loop of the oscillator. These are
mixed with the signal through the nonlinear amplifier, which makes them
{cyclostationary}. We also consider noise sources acting directly on the
resonator. The expressions allow us to investigate reducing the oscillator
phase noise thereby improving the frequency precision using resonator
nonlinearity by tuning to special operating points. We illustrate the approach
giving explicit results for a phenomenological amplifier model. We also propose
a scheme for measuring the slow feedback noise generated by the feedback
components in an open-loop driven configuration in experiment or using circuit
simulators, which enables the calculation of the closed-loop oscillator phase
noise in practical systems.",1510.07331v2
2015-10-27,Ghost-Stochastic Resonance in a Unidirectionally Coupled and Small-World Networks,"Ghost-stochastic resonance is a noise-induced resonance at a missing
fundamental frequency in the input signal. In this paper we investigate the
features of ghost-stochastic resonance in a unidirectionally coupled network
and small-world network with each unit being bistable Bellows map. In the
one-way coupled network we apply a multi-frequency signal $(1/n_{\mathrm{f}})
\sum_{j=1}^{n_{\mathrm{f}}} \cos (\omega_{j}n)$, $n=0,1,2,\cdots$,
$\omega_{j}=(k+j-1)\omega_{0}$, with $k$ being an integer $\ge2$ (without the
fundamental frequency $\omega_{0}$) and noise to first unit only. We show the
occurrence of resonance and undamped signal propagation for coupling strength
above a certain critical value. The response amplitude shows sigmoidal function
type variation with unit number. We report the effect of coupling strength
$\delta$, $k$ and $n_{\mathrm{f}}$ on the response amplitude. In the
small-world network randomness in the connectivity topology is described by the
probability $p$ of rewiring of units in a ring type regular network where all
the units are subjected to noise and multi-frequency signal. We present the
influence of $p$ and the coupling strength on the probability distribution of
response amplitude $Q$ of various units, $\langle Q \rangle$ and the maximum
value of $Q$.",1510.07887v1
2015-10-30,Resonances at the LHC beyond the Higgs: The Scalar/Tensor Case,"We study in a bottom-up approach the theoretically consistent description of
additional resonances in the electroweak sector beyond the discovered Higgs
boson as simplified models. We focus on scalar and tensor resonances. Our
formalism is suited for strongly coupled models, but can also be applied to
weakly interacting theories. The spurious degrees of freedom of tensor
resonances that would lead to bad high-energy behavior are treated using a
generalization of the Stuckelberg formalism. We calculate scattering amplitudes
for vector-boson and Higgs boson pairs. The high-energy region is regulated by
the T-matrix unitarization procedure, leading to amplitudes that are well
behaved on the whole phase space. We present numerical results for complete
partonic processes that involve resonant vector-boson scattering, for the
current and upcoming runs of LHC.",1511.00022v2
2015-11-01,Current noise of the interacting resonant level model,"We study the zero-frequency current noise of the interacting resonant level
model for arbitrary bias voltages using a functional renormalization group
approach. For this we extend the existing nonequilibrium scheme by deriving and
solving flow equations for the current-vertex functions. On-resonance
artificial divergences of the latter found in lowest-order perturbation theory
in the two-particle interaction are consistently removed. Away from resonance
they are shifted to higher orders. This allows us to gain a comprehensive
picture of the current noise in the scaling limit. At high bias voltages, the
current noise exhibits a universal power-law decay, whose exponent is to
leading order in the interaction identical to that of the current. The
effective charge on resonance is analyzed in detail employing properties of the
vertex correction. We find that it is only modified to second or higher order
in the two-particle interaction.",1511.00259v2
2015-11-10,Nanofluidics of Single-crystal Diamond Nanomechanical Resonators,"Single-crystal diamond nanomechanical resonators are being developed for
countless applications. A number of these applications require that the
resonator be operated in a fluid, i.e., a gas or a liquid. Here, we investigate
the fluid dynamics of single-crystal diamond nanomechanical resonators in the
form of nanocantilevers. First, we measure the pressure-dependent dissipation
of diamond nanocantilevers with different linear dimensions and frequencies in
three gases, He, N$_2$, and Ar. We observe that a subtle interplay between the
length scale and the frequency governs the scaling of the fluidic dissipation.
Second, we obtain a comparison of the surface accommodation of different gases
on the diamond surface by analyzing the dissipation in the molecular flow
regime. Finally, we measure the thermal fluctuations of the nanocantilevers in
water, and compare the observed dissipation and frequency shifts with
theoretical predictions. These findings set the stage for developing diamond
nanomechanical resonators operable in fluids.",1511.02940v1
2015-11-12,Signal amplification in a qubit-resonator system,"We study the dynamics of a qubit-resonator system, when the resonator is
driven by two signals. The interaction of the qubit with the high-amplitude
driving we consider in terms of the qubit dressed states. Interaction of the
dressed qubit with the second probing signal can essentially change the
amplitude of this signal. We calculate the transmission amplitude of the probe
signal through the resonator as a function of the qubit's energy and the
driving frequency detuning. The regions of increase and attenuation of the
transmitted signal are calculated and demonstrated graphically. We present the
influence of the signal parameters on the value of the amplification, and
discuss the values of the qubit-resonator system parameters for an optimal
amplification and attenuation of the weak probe signal.",1511.04118v1
2015-11-19,High-precision spectral tuning of micro and nanophotonic cavities by resonantly enhanced photoelectrochemical etching,"We present a simple method to tune optical micro- and nanocavities with
picometer precision in the resonant wavelength, corresponding to an effective
sub atomic monolayer control of the cavity dimension. This is obtained through
resonant photo-electrochemical etching, with in-situ monitoring of the optical
spectrum. We employ this technique to spectrally align an ensemble of resonant
cavities in a permanent manner, overcoming the dimension variability resulting
from current nanofabrication techniques. In a device containing several
resonators, each is individually addressed and tuned, with no optical quality
factor degradation. The technique is general and opens the way to multiple
applications, such as the straightforward fabrication of networks of identical
coupled resonators, or the tuning of chip-based cavities to external
references.",1511.06186v1
2015-12-31,How Resonance-Continuum Interference Changes 750 GeV Diphoton Excess: Signal Enhancement and Peak Shift,"The new scalar resonance contribution to the 750 GeV diphoton excess observed
at the LHC 13 TeV necessarily interferes with the continuum background in the
$gg\to \gamma \gamma$. The interference has two considerable effects: (1)
enhancing or suppressing diphoton signal rate due to the imaginary-part
interference and (2) distorting resonance shape due to the real-part
interference. From the best-fit study of two benchmark models (two Higgs
doublets with $\sim$50 GeV widths and a singlet scalar with 5 GeV width, both
extended with vector-like fermions), we find that the resonance contribution to
the 750 GeV excess can be enhanced by a factor of 2(1.6) for 3(6) fb signal
rate and the 68%(95%) CL best-fit mass range can shift by 1-4 (any ${\cal
O}$(1)) GeV. If the best-fit excess rate decreases with future data, the
interference effects will become more significant. The inevitable interferences
can also provide a consistency check of a resonance hypothesis, whether or not
future precision shape measurements confirm a Breit-Wigner shape or discover
interesting deviations.",1601.00006v1
2016-01-01,Inverse design of resonant nanostructures for extraordinary optical transmission of periodic metallic slits,"This paper has presented inversely determining the resonant configuration of
the bilateral nanostructures for periodic metallic slits with extraordinary
optical transmission performance. The topology optimization approach is
utilized to implement the inverse design procedure. Several geometrical
configurations of the bilateral nanostructures are derived for periodic
metallic slits. The resonant performance of the derived nanostructures are
demonstrated by the transmission spectra, where the transmission peak is
presented at the specified wavelength in the inverse design procedure. This
provides an approach to control the red or blue shift of the transmission peak
or localize the resonant performance at a desired frequency, by specifying the
desired incident wavelength in the inverse design procedure. The inverse design
method is extended to make the periodic metallic slits to be less sensitive to
the incident wavelength. This research can be further extended to inversely
find the resonant subwavelength structures for extraordinary optical absorption
and other surface palsmon polariton based photonic devices. The inverse design
of three dimensional apertures for extraordinary optical transmission will be
investigated in our future researches.",1601.00049v3
2016-01-04,Subgap resonant quasiparticle transport in normal-superconductor quantum dot devices,"We report thermally activated transport resonances for biases below the
superconducting energy gap in a carbon nanotube (CNT) quantum dot (QD) device
with a superconducting Pb and a normal metal contact. These resonances are due
to the superconductor's finite quasi-particle population at elevated
temperatures and can only be observed when the QD life-time broadening is
considerably smaller than the gap. This condition is fulfilled in our QD
devices with optimized Pd/Pb/In multi-layer contacts, which result in
reproducibly large and ""clean"" superconducting transport gaps with a strong
conductance suppression for subgap biases. We show that these gaps close
monotonically with increasing magnetic field and temperature. The accurate
description of the subgap resonances by a simple resonant tunneling model
illustrates the ideal characteristics of the reported Pb contacts and gives an
alternative access to the tunnel coupling strengths in a QD.",1601.00672v2
2016-01-06,Properties of wideband resonant reflectors under fully conical light incidence,"Applying numerical modeling coupled with experiments, we investigate the
properties of wideband resonant reflectors under fully conical light incidence.
We show that the wave vectors pertinent to resonant first-order diffraction
under fully conical mounting vary less with incident angle than those
associated with reflectors in classical mounting. Therefore, as the evanescent
diffracted waves drive the leaky modes responsible for the resonance effects,
fully-conical mounting imbues reflectors with larger angular tolerance than
their classical counterparts. We quantify the angular-spectral performance of
representative resonant wideband reflectors in conic and classic mounts by
numerical calculations with improved spectra found for fully conic incidence.
Moreover, these predictions are verified experimentally for wideband reflectors
fashioned in crystalline and amorphous silicon in distinct spectral regions
spanning the 1200-1600-nm and 1600-2400-nm spectral bands. These results will
be useful in various applications demanding wideband reflectors that are
efficient and materially sparse.",1601.01333v1
2016-01-11,Establishing mass spectrum of $S=-1$ hyperon resonances via a dynamical coupled-channels analysis of $K^-p$ reactions,"We report our recent effort for the extraction of resonance parameters
(complex pole mass and residues etc.) associated with Lambda* and Sigma*
hyperons. This was accomplished via a comprehensive partial-wave analysis of
the data for K^- p --> barK N, pi Sigma, pi Lambda, eta Lambda, K Xi reactions
from the thresholds up to W=2.1 GeV within a dynamical coupled-channels
approach. The results suggest a possible existence of new narrow J^P=3/2^+
\Lambda resonance with pole mass 1671^{+2}_{-8} -i(5^{+11}_{-2}) MeV, located
close to the eta Lambda threshold. This resonance is found to be responsible
for reproducing the data for K^-p --> eta Lambda differential cross sections
near the threshold, and thus the data seem favor its existence. The extracted
poles for J^P=1/2^- Lambda resonances below the barK N threshold, including
Lambda(1405), are also presented.",1601.02322v1
2016-01-13,Resonant Multilead Point-Contact Tunneling: Boundary State Formulation,"We study a model of resonant multilead point-contact tunneling by using the
boundary state formulation. At a critical point the model is described by
multi-flavor chiral fermions on an infinite line with a point contact
interaction at the origin. By applying the folding procedure, previously
developed for the model of resonant point-contact tunneling of a single lead,
we map the model onto a non-chiral fermion model defined on the half line. The
resonant point-contact tunneling interaction is transcribed into a non-local
effective boundary interaction in the folded setup, where the boundary state
formulation is applicable. We construct the boundary states for the models with
two and three leads explicitly and evaluate the correlation functions of
currents operators exactly. The electron transport between the leads is
dominated by the resonant point-contact tunneling in the low frequency regime.
We observe some $SU(2)$ and $SU(3)$ group theoretical structures, which may be
useful to analyze more complex models.",1601.03126v1
2016-01-15,Superconducting cavity-electromechanics on silicon-on-insulator,"Fabrication processes involving anhydrous hydrofluoric vapor etching are
developed to create high-$Q$ aluminum superconducting microwave resonators on
free-standing silicon membranes formed from a silicon-on-insulator wafer. Using
this fabrication process, a high-impedance $8.9$GHz coil resonator is coupled
capacitively with large participation ratio to a $9.7$MHz micromechanical
resonator. Two-tone microwave spectroscopy and radiation pressure back-action
are used to characterize the coupled system in a dilution refrigerator down to
temperatures of $T_f = 11$~mK, yielding a measured electromechanical vacuum
coupling rate of $g_{0}/2\pi \approx 24.6$~Hz and a mechanical resonator
$Q$-factor of $Q_{m}=1.7\times 10^7$. Microwave back-action cooling of the
mechanical resonator is also studied, with a minimum phonon occupancy of $n_{m}
\approx 16$ phonons being realized at an elevated fridge temperature of $T_f =
211$~mK.",1601.04019v1
2016-02-17,Chaos synchronization by resonance of multiple delay times,"Chaos synchronization may arise in networks of nonlinear units with delayed
couplings. We study complete and sublattice synchronization generated by
resonance of two large time delays with a specific ratio. As it is known for
single delay networks, the number of synchronized sublattices is determined by
the Greatest Common Divisor (GCD) of the network loops lengths. We demonstrate
analytically the GCD condition in networks of iterated Bernouilli maps with
multiple delay times and complement our analytic results by numerical phase
diagrams, providing parameter regions showing complete and sublattice
synchronization by resonance for Tent and Bernouilli maps. We compare networks
with the same GCD with single and multiple delays, and we investigate the
sensitivity of the correlation to a detuning between the delays in a network of
coupled Stuart-Landau oscillators. Moreover, the GCD condition also allows to
detect time delay resonances leading to high correlations in non-synchronizable
networks. Specifically, GCD-induced resonances are observed both in a chaotic
asymmetric network and in doubly connected rings of delay-coupled noisy linear
oscillators.",1602.05358v1
2016-02-19,Pion production off the nucleon,"We have studied charged current neutrino/antineutrino induced weak pion
production from nucleon. For the present study, contributions from
$\Delta(1232)$-resonant term, non-resonant background terms as well as
contribution from higher resonances viz. $P_{11}$(1440), $D_{13}$(1520),
$S_{11}$(1535), $S_{11}$(1650) and $P_{13}$(1720) are taken. To write the
hadronic current for the non-resonant background terms, a microscopic approach
based on SU(2) non-linear sigma model has been used. The vector form factors
for the resonances are obtained from the helicity amplitudes provided by MAID.
Axial coupling in the case of $\Delta(1232)$ resonance is obtained by fitting
the ANL and BNL $\nu$-deuteron reanalyzed scattering data. The results of the
cross sections are presented and discussed for all the possible channels of
single pion production induced by charged current interaction.",1602.06066v1
2016-02-24,Non-linear modeling of the plasma response to RMPs in ASDEX Upgrade,"The plasma response to Resonant Magnetic Perturbations (RMPs) in ASDEX
Upgrade is modeled with the non-linear resistive MHD code JOREK, using input
profiles that match those of the experiments as closely as possible. The RMP
configuration for which Edge Localized Modes are best mitigated in experiments
is related to the largest edge kink response observed near the X-point in
modeling. On the edge resonant surfaces $q = m/n$, the coupling between the m +
2 kink component and the m resonant component is found to induce the
amplification of the resonant magnetic perturbation. The ergodicity and the
3D-displacement near the X-point induced by the resonant amplification can only
partly explain the density pumpout observed in experiments.",1602.07564v1
2016-02-24,Boosting low-mass hadronic resonances,"Searches for new hadronic resonances typically focus on high-mass spectra,
due to overwhelming QCD backgrounds and detector trigger rates. We present a
study of searches for relatively low-mass hadronic resonances at the LHC in the
case that the resonance is boosted by recoiling against a well-measured
high-$p_{\textrm{T}}$ probe such as a muon, photon or jet. The hadronic decay
of the resonance is then reconstructed either as a single large-radius jet or
as a resolved pair of standard narrow-radius jets, balanced in transverse
momentum to the probe. We show that the existing 2015 LHC dataset of $pp$
collisions with $\int\mathcal{L}dt = 4\ \mathrm{fb}^{-1}$ should already have
powerful sensitivity to a generic $Z'$ model which couples only to quarks, for
$Z'$ masses ranging from 20-500 GeV/c$^2$.",1602.07727v1
2016-03-05,Exploiting spatiotemporal degrees of freedom for far field subwavelength focusing using time reversal in fractals,"Materials which possess a high local density of states varying at a
subwavelength scale theoretically permit to focus waves onto focal spots much
smaller than the free space wavelength. To do so metamaterials -manmade
composite media exhibiting properties not available in nature- are usually
considered. However this approach is limited to narrow bandwidths due to their
resonant nature. Here, we prove that it is possible to use a fractal resonator
alongside time reversal to focus microwaves onto $\lambda/15$ subwavelength
focal spots from the far field, on extremely wide bandwidths. We first
numerically prove that this approach can be realized using a multiple channel
time reversal mirror, that utilizes all the degrees of freedom offered by the
fractal resonator. Then we experimentally demonstrate that this approach can be
drastically simplified by coupling the fractal resonator to a complex medium,
here a cavity, that efficiently converts its spatial degrees of freedom into
temporal ones. This allows to achieve deep subwavelength focusing of microwaves
using a single channel time reversal. Our method can be generalized to other
systems coupling complex media and fractal resonators.",1603.01725v1
2016-03-14,Resonant Diphoton Phenomenology Simplified,"A framework is proposed to describe resonant diphoton phenomenology at hadron
colliders in full generality. It can be employed for a comprehensive
model-independent interpretation of the experimental data. Within the general
framework, few benchmark scenarios are defined as representative of the various
phenomenological options and/or of motivated new physics scenarios. Their usage
is illustrated by performing a characterization of the 750 GeV excess, based on
a recast of available experimental results.
  We also perform an assessment of which properties of the resonance could be
inferred, after discovery, by a careful experimental study of the diphoton
distributions. These include the spin J of the new particle and its dominant
production mode. Partial information on its CP-parity can also be obtained, but
only for $J\geq2$. The complete determination of the resonance CP properties
requires studying the pattern of the initial state radiation that accompanies
the resonant diphoton production.",1603.04248v3
2016-03-22,Internal resonances and dynamic responses in equivalent mechanical model of partially liquid-filled vessel,"The paper treats oscillations of a liquid in partially filled vessel under
horizontal harmonic ground excitation. Such excitation may lead to hydraulic
impacts. The liquid sloshing mass is modeled by equivalent pendulum, which can
impact the vessel walls. We use parameters of the equivalent pendulum for
well-explored case of cylindrical vessels. The hydraulic impacts are modeled by
high-power potential function. Conditions for internal resonances are
presented. A non-resonant behavior and dynamic response related to 3:1 internal
resonance are explored. When the excitation amplitude exceeds a critical value,
the system exhibits multiple steady state solutions. Quasi-periodic solutions
appear in relatively narrow range of parameters. Numerical continuation links
between resonant regimes found asymptotically for small excitation amplitude,
and high-amplitude responses with intensive impacts.",1603.06931v1
2016-03-22,Reconstruction of annular bi-layered media in cylindrical waveguide section,"A radial transverse resonance model for two cylindrical concentric layers
with different complex dielectric constants is presented. An inverse problem
with four unknowns - 3 physical material parameters and one dimensional
dielectric layer thickness parameter- is solved by employing TE110 and TE210
modes with different radial field distribution. First a Newton-Raphson
algorithm is used to solve a least square problem with a Lorentzian function
(as resonance model and ""measured"" data generator). Then found resonance
frequencies and quality factors are used in a second inverse Newton-Raphson
algorithm that solves four transverse resonance equations in order to get four
unknown parameters. The use of TE110 and TE210 models offers one dimensional
radial tomographic capability. An open ended coax quarter-wave resonator is
added to the sensor topology, and the effect on the convergence is
investigated.",1603.06940v1
2016-04-06,Localized surface plasmons selectively coupled to resonant light in tubular microcavities,"Vertical gold-nanogaps are created on microtubular cavities to explore the
coupling between resonant light supported by the microcavities and surface
plasmons localized at the nanogaps. Selective coupling of optical axial modes
and localized surface plasmons critically depends on the exact location of the
gold-nanogap on the microcavities which is conveniently achieved by rolling-up
specially designed thin dielectric films into three dimensional microtube ring
resonators. The coupling phenomenon is explained by a modified quasi-potential
model based on perturbation theory. Our work reveals the coupling of surface
plasmon resonances localized at the nanoscale to optical resonances confined in
microtubular cavities at the microscale, implying a promising strategy for the
investigation of light-matter interactions.",1604.01599v1
2016-04-12,Q-enhanced racetrack micro-resonators,"A $Q$-enhancement strategy for racetrack microresonators is put forward. The
design is based on the modification of the resonator geometry in order to
mitigate the two main sources of radiation loss in the presence of curved
waveguides: the discontinuities at the junctions between straight waveguides
and the bent sections, and the continuous loss at the curved waveguide sectors.
At the same time, the modifications of the geometry do not affect the
versatility of coupling of racetrack resonators in integrated optical circuits,
which is their main advantage over ring microresonators. The proposal is
applied to the design of high-$Q$ racetrack resonators for the silicon nitride
CMOS-compatible platform having bent radii amenable for large-scale photonic
integration. Numerical calculations show over $100\%$ improvement of the $Q$
factor in $\text{Si}_3\text{N}_4/\text{SiO}_2$ resonators.",1604.03474v3
2016-04-14,Cumulative production of pions by heavy baryonic resonances in proton-nucleus collisions,"Pion production in proton-nucleus (p+A) collisions outside the kinematical
boundary of proton-nucleon (p+N) reactions, the so-called cumulative effect, is
studied. Restrictions from energy-momentum conservation on the energy of pions
emitted in the backward direction in the target rest frame are analyzed. It is
assumed that the cumulative pions are produced in p+A reactions by heavy
baryonic resonances. The baryonic resonances are first created in p+N
reactions. Due to successive collisions with nuclear nucleons the masses of
these resonances may then increase and, simultaneously, their longitudinal
velocities decrease. We also use the Ultra relativistic Quantum Molecular
Dynamics model to reveal the key role of successive collisions of baryonic
resonances with nuclear nucleons for cumulative pion production in p+A
reactions. Further experimental studies of cumulative hadron production in p+A
reactions at high collision energies are needed to search for heavy hadron-like
objects and investigate their properties.",1604.04308v1
2016-04-15,On the possibility of generating a 4-neutron resonance with a {\boldmath $T=3/2$} isospin 3-neutron force,"We consider the theoretical possibility to generate a narrow resonance in the
four neutron system as suggested by a recent experimental result. To that end,
a phenomenological $T=3/2$ three neutron force is introduced, in addition to a
realistic $NN$ interaction. We inquire what should be the strength of the $3n$
force in order to generate such a resonance. The reliability of the
three-neutron force in the $T=3/2$ channel is exmined, by analyzing its
consistency with the low-lying $T=1$ states of $^4$H, $^4$He and $^4$Li and the
$^3{\rm H} + n$ scattering.
  The {\it ab initio} solution of the $4n$ Schr\""{o}dinger equation is obtained
using the complex scaling method with boundary conditions appropiate to the
four-body resonances. We find that in order to generate narrow $4n$ resonant
states a remarkably attractive $3N$ force in the $T=3/2$ channel is required.",1604.04363v2
2016-04-19,Implications of perturbative unitarity for scalar di-boson resonance searches at LHC,"We study the constraints implied by partial wave unitarity on new physics in
the form of spin-zero di-boson resonances at LHC. We derive the scale where the
effective description in terms of the SM supplemented by a single resonance is
expected to break down depending on the resonance mass and signal
cross-section. Likewise, we use unitarity arguments in order to set
perturbativity bounds on renormalizable UV completions of the effective
description. We finally discuss under which conditions scalar di-boson
resonance signals can be accommodated within weakly-coupled models.",1604.05746v3
2016-04-20,Resonant vibrational-excitation cross sections and rate constants for low-energy electron scattering by molecular oxygen,"Resonant vibrational-excitation cross sections and rate constants for
electron scattering by molecular oxygen are presented. Transitions between all
42 vibrational levels of O$_2(\textrm{X}\ ^3\Sigma_g^- $) are considered.
Molecular rotations are parameterized by the rotational quantum number $J$
which is considered in the range 1 to 151. The lowest four resonant states of
O$_2^-$, $^2\Pi_g$, $^2\Pi_u$, $^4\Sigma_u^-$ and $^2\Sigma_u^-$, are taken
into account. The calculations are performed using the fixed-nuclei R-matrix
approach to determine the resonance positions and widths, and the boomerang
model to characterize the nuclei motion. Two energy regions below and above
4~eV are investigated: the first one is characterized by sharp structures in
the cross section, and the second by a broad resonance peaked at 10~eV. The
computed cross sections are compared with theoretical and experimental results
available in literature for both the energy regions, and are made available for
use by modelers. The effect of including rotational motion is found to be
non-negligible.",1604.05871v1
2016-04-23,Telling the spin of the di-photon resonance,"We argue that the spin of the 750 GeV resonance can be determined at the
99.7% confidence level in the di-photon channel with as few as 10 fb$^{-1}$ of
luminosity. This result is true if the resonance is produced by gluon fusion
(independently of the selection cuts) while an appropriate choice of selection
cuts is needed if quark production is sub-dominantly present--which is the case
of the Kaluza-Klein gravitational excitation under the hypothesis of a spin-2
resonance. A proportionally larger luminosity is required if the model for the
spin-2 resonance includes a dominant production by quarks or in the absence of
an efficient separation of the signal from the background.",1604.06948v1
2016-04-26,Optimal width of quasi-crystalline slabs of dielectric cylinders to light transmission contrast,"Light confinement induced by resonant states in aperiodic photonic structures
are interesting for many applications. A particular case of these resonances
can be found in 2D quasi-crystalline arrangements of dielectric cylinders.
These systems present a rather isotropic band gap as well as isolated in-gap
photonic states (as a result of spatially localized resonances). These states
are built by high symmetry polygonal clusters that can be regarded as photonic
molecules. In this paper we study the transmission properties of a slab of
glass cylinders arranged in approximants of decagonal quasi-crystalline
structure. In particular, we investigate the influence of the slab width in the
transmission contrast between the states and the gap. The study is both
experimental and numerical in the microwave regime. We find that the best
transmission contrast is found for a width of around 3 times the radiation
wavelength. The transmission at the band gap region is mediated by the
resonances of the photonic molecules. If the samples are thin enough they
become transparent except around a resonance of the photonic molecule which
reflects the incoming light. In this case the behavior is reminiscent of an
absorbing molecule.",1604.07640v1
2016-04-27,Sum rules for interaction of $Υ$ resonances with $Z_b π$,"The strength of the amplitudes for the coupling between the bottomonium
$\Upsilon(nS)$ states, the bottomonium-like isovector resonances $Z_b$ and a
pion, $\Upsilon(nS) Z_b \pi$, is considered. These amplitudes describe the
decays $Z_b \to \Upsilon(nS) \pi$ for $n=1,\,2,\,3$, and the processes
$\Upsilon(nS) \to Z_b \pi$ for $n=5,\,6, \ldots$ with either $Z_b(10610)$ or
$Z_b(10650)$. It is pointed out that analyticity and unitarity impose a sum
rule for these couplings to each of the $Z_b$ resonances. With the currently
available data it appears to be difficult or impossible to simultaneously
satisfy the sum rules for the $Z_b(10610)$ and $Z_b(10650)$ resonances. This
difficulty can be resolved if there is a considerable dissimilarity in the
yield of the states $Z_b(10610) \pi$ and $Z_b(10650) \pi$ in the $e^+e^-$
annihilation at energies above the $\Upsilon(5S)$ resonance.",1604.08196v3
2016-04-28,Effective medium theory for acoustic waves in bubbly fluids near Minnaert resonant frequency,"We derive an effective medium theory for acoustic wave propagation in bubbly
fluid near Minnaert resonant frequency. We start with a multiple scattering
formulation of the scattering problem of an incident wave by a large number of
identical small bubbles in a homogeneous fluid. Under certain conditions on the
configuration of the bubbles, we justify the point interaction approximation
and establish an effective medium theory for the bubbly fluid as the number of
bubbles tends to infinity. The convergence rate is also derived. As a
consequence, we show that near and below the Minnaert resonant frequency, the
obtained effective media can have a high refractive index, which is the reason
for the super-focusing experiment observed in ""Subwavelength focusing in bubbly
media using broadband time reversal"", Physical Review, B (2015), by M. Lanoy et
al. Moreover, our results indicate that the obtained effective medium can be
dissipative above the Minnaert resonant frequency, while at that frequency,
effective medium theory does not hold. Our theory sheds light on the mechanism
of the extraordinary wave properties of metamaterials, which include bubbly
fluid as an example, near resonant frequencies.",1604.08409v1
2016-06-07,Spontaneous emergence of van der Waals interaction in piezo-resonators - a road to phase coherence at mK temperatures,"We present the experimental results on the spontaneous emergence of the phase
coherence in the system of oscillating electric dipoles in quartz
piezo-resonators caused by the van der Waals interaction. Spontaneous emergence
of the phase coherence in these systems is manifested via
temperature-dependent, extremely accurate tune-up of their resonance
frequencies in 9th order with relative spectral line-width $\delta f_0/f_0$
less than 3.10$^{-8}$ (this number is comparable with that in lasers) along
with the very high frequency stability characterized by the low values of the
Allan deviations. We also show that the application of an incoherent (noise)
excitation signal leads to a spontaneous formation of the phase coherent state,
and that the dissipation processes do not affect this phase coherent state
(i.e. the resonance frequency of the system). All above-mentioned signatures
are typical characteristics for a Bose-Einstein condensate of excitations.
Smallness of the relative spectral lime-width in quartz piezo-resonators opens
their potential application as alternative time etalons.",1606.02103v5
2016-06-08,Uncovering the relation of a scalar resonance to the Higgs boson,"We consider the associated production of a scalar resonance with the standard
model Higgs boson. We demonstrate via a realistic phenomenological analysis
that couplings of such a resonance to the Higgs boson can be constrained in a
meaningful way in future runs of the LHC, providing insights on its origin and
its relation to the electroweak symmetry breaking sector. Moreover, the final
state can provide a direct way to determine whether the new resonance is
produced predominantly in gluon fusion or quark-anti-quark annihilation. The
analysis focusses on a resonance coming from a scalar field with vanishing
vacuum expectation value and its decay to a photon pair. It can however be
straightforwardly generalised to other scenarios.",1606.02716v2
2016-06-08,Collective resonance fluorescence in small and dense atom clouds: Comparison between theory and experiment,"We study the emergence of a collective optical response of a cold and dense
$^{87}$Rb atomic cloud to a near-resonant low-intensity light when the atom
number is gradually increased. Experimental observations are compared with
microscopic stochastic simulations of recurrent scattering processes between
the atoms that incorporate the atomic multilevel structure and the optical
measurement setup. We analyze the optical response of an
inhomogeneously-broadened gas and find that the experimental observations of
the resonance line shifts and the total collected scattered light intensity in
cold atom clouds substantially deviate from those of thermal atomic ensembles,
indicating strong light-induced resonant dipole-dipole interactions between the
atoms. At high densities, the simulations also predict a significantly slower
decay of light-induced excitations in cold than in thermal atom clouds. The
role of dipole-dipole interactions is discussed in terms of resonant coupling
examples and the collective radiative excitation eigenmodes of the system.",1606.02757v2
2016-06-10,Resonant Thermoelectric Nanophotonics,"Photodetectors are typically based on photocurrent generation from
electron-hole pairs in semiconductor structures and on bolometry for
wavelengths that are below bandgap absorption. In both cases, resonant
plasmonic and nanophotonic structures have been successfully used to enhance
performance. In this work, we demonstrate subwavelength thermoelectric
nanostructures designed for resonant spectrally selective absorption, which
creates large enough localized temperature gradients to generate easily
measureable thermoelectric voltages. We show that such structures are tunable
and are capable of highly wavelength specific detection, with an input power
responsivity of up to 119 V/W (referenced to incident illumination), and
response times of nearly 3 kHz, by combining resonant absorption and
thermoelectric junctions within a single structure, yielding a
bandgap-independent photodetection mechanism. We report results for both
resonant nanophotonic bismuth telluride-antimony telluride structures and
chromel-alumel structures as examples of a broad class of nanophotonic
thermoelectric structures useful for fast, low-cost and robust optoelectronic
applications such as non-bandgap-limited hyperspectral and broad-band
photodetectors.",1606.03313v1
2016-06-13,Search for resonant production of high-mass photon pairs in proton-proton collisions at sqrt(s) = 8 and 13 TeV,"A search for the resonant production of high-mass photon pairs is presented.
The analysis is based on samples of proton-proton collision data collected by
the CMS experiment at center-of-mass energies of 8 and 13 TeV, corresponding to
integrated luminosities of 19.7 and 3.3 inverse femtobarns, respectively. The
search focuses on spin-0 and spin-2 resonances with masses between 0.5 and 4
TeV and with widths, relative to the mass, between 1.4E-4 and 5.6E-2. Limits
are set on scalar resonances produced through gluon-gluon fusion, and on
Randall-Sundrum gravitons. A modest excess of events compatible with a narrow
resonance with a mass of about 750 GeV is observed. The local significance of
the excess is approximately 3.4 standard deviations. The significance is
reduced to 1.6 standard deviations once the effect of searching under multiple
signal hypotheses is considered. More data are required to determine the origin
of this excess.",1606.04093v2
2016-06-14,Measuring a transmon qubit in circuit QED: dressed squeezed states,"Using circuit QED, we consider the measurement of a superconducting transmon
qubit via a coupled microwave resonator. For ideally dispersive coupling,
ringing up the resonator produces coherent states with frequencies matched to
transmon energy states. Realistic coupling is not ideally dispersive, however,
so transmon-resonator energy levels hybridize into joint eigenstate ladders of
the Jaynes-Cummings type. Previous work has shown that ringing up the resonator
approximately respects this ladder structure to produce a coherent state in the
eigenbasis (a dressed coherent state). We numerically investigate the validity
of this coherent state approximation to find two primary deviations. First,
resonator ring-up leaks small stray populations into eigenstate ladders
corresponding to different transmon states. Second, within an eigenstate ladder
the transmon nonlinearity shears the coherent state as it evolves. We then show
that the next natural approximation for this sheared state in the eigenbasis is
a dressed squeezed state, and derive simple evolution equations for such states
using a hybrid phase-Fock-space description.",1606.04204v2
2016-06-29,Observation of resonant interactions among surface gravity waves,"We experimentally study resonant interactions of oblique surface gravity
waves in a large basin. Our results strongly extend previous experimental
results performed mainly for perpendicular or collinear wave trains. We
generate two oblique waves crossing at an acute angle, while we control their
frequency ratio, steepnesses and directions. These mother waves mutually
interact and give birth to a resonant wave whose properties (growth rate,
resonant response curve and phase locking) are fully characterized. All our
experimental results are found in good quantitative agreement with four-wave
interaction theory with no fitting parameter. Off-resonance experiments are
also reported and the relevant theoretical analysis is conducted and validated.",1606.09009v3
2016-06-30,Creating Feshbach resonances for ultracold molecule formation with radiofrequency fields,"We show that radiofrequency (RF) radiation may be used to create Feshbach
resonances in ultracold gases of alkali-metal atoms at desired magnetic fields
that are convenient for atomic cooling and degeneracy. For the case of
$^{39}$K+$^{133}$Cs, where there are no RF-free resonances in regions where Cs
may be cooled to degeneracy, we show that a resonance may be created near 21~G
with 69.2~MHz RF radiation. This resonance is almost lossless with circularly
polarized RF, and the molecules created are long-lived even with
plane-polarized RF.",1606.09441v2
2016-06-30,Efficient resonance computations for Helmholtz problems based on a Dirichlet-to-Neumann map,"We present an efficient procedure for computing resonances and resonant modes
of Helmholtz problems posed in exterior domains. The problem is formulated as a
nonlinear eigenvalue problem (NEP), where the nonlinearity arises from the use
of a Dirichlet-to-Neumann map, which accounts for modeling unbounded domains.
We consider a variational formulation and show that the spectrum consists of
isolated eigenvalues of finite multiplicity that only can accumulate at
infinity. The proposed method is based on a high order finite element
discretization combined with a specialization of the Tensor Infinite Arnoldi
method. Using Toeplitz matrices, we show how to specialize this method to our
specific structure. In particular we introduce a pole cancellation technique in
order to increase the radius of convergence for computation of eigenvalues that
lie close to the poles of the matrix-valued function. The solution scheme can
be applied to multiple resonators with a varying refractive index that is not
necessarily piecewise constant. We present two test cases to show stability,
performance and numerical accuracy of the method. In particular the use of a
high order finite element discretization together with TIAR results in an
efficient and reliable method to compute resonances.",1606.09547v1
2016-07-07,Cracking Down on Fake Photons - A Case of 750 GeV Diphoton Resonance -,"Among various models to explain the $750$ GeV diphoton resonance hinted at
the LHC Run 2, a class of models where the resonance decays not into a pair of
photons but into a pair of photon-jets is gathering definite attention. In this
paper, we study how well we can distinguish the di-photon-jet resonance from
the diphoton resonance by examining detector responses to the photon-jets. We
find that the sum of $p_T$ of the first $e^+e^-$ pair from the photon
conversion provides strong discrimination power. We also discuss determination
of the lifetime of the light intermediate particle by measuring the photon
conversion points.",1607.01936v2
2016-07-07,Resonance fluorescence from a telecom-wavelength quantum dot,"We report on resonance fluorescence from a single quantum dot emitting at
telecom wavelengths. We perform high-resolution spectroscopy and observe the
Mollow triplet in the Rabi regime--a hallmark of resonance fluorescence. The
measured resonance-fluorescence spectra allow us to rule out pure dephasing as
a significant decoherence mechanism in these quantum dots. Combined with
numerical simulations, the experimental results provide robust characterisation
of charge noise in the environment of the quantum dot. Resonant control of the
quantum dot opens up new possibilities for on-demand generation of
indistinguishable single photons at telecom wavelengths as well as quantum
optics experiments and direct manipulation of solid-state qubits in
telecom-wavelength quantum dots.",1607.02063v1
2016-03-10,A study of the lunisolar secular resonance $2\dotω+\dotΩ=0$,"The dynamics of small bodies around the Earth has gained a renewed interest,
since the awareness of the problems that space debris can cause in the nearby
future. A relevant role in space debris is played by lunisolar secular
resonances, which might contribute to an increase of the orbital elements,
typically of the eccentricity. We concentrate our attention on the lunisolar
secular resonance described by the relation $2\dot{\omega}+\dot{\Omega}=0$,
where $\omega$ and $\Omega$ denote the argument of perigee and the longitude of
the ascending node of the space debris. We introduce three different models
with increasing complexity. We show that the growth in eccentricity, as
observed in space debris located in the MEO region at the inclination about
equal to $56^\circ$, can be explained as a natural effect of the secular
resonance $2\dot{\omega}+\dot{\Omega}=0$, while the chaotic variations of the
orbital parameters are the result of interaction and overlapping of nearby
resonances.",1607.03767v1
2016-07-14,Breakdown of Effective Field Theory for a Gluon Initiated Resonance,"Gauge invariance dictates that a resonance produced from initial state gluons
must be produced through a non-renormalizable operator or a loop process.
Should such a resonance be discovered, uncovering the dynamics that give rise
to its couplings to gluons will be crucial to understanding the nature of the
new state. Here we study how the production of this resonance at high
transverse momentum in association with one (or more) jets can be used to
directly measure the scale of the operator or the mass of the particles in the
loop. We use a 750 GeV diphoton resonance as an example application, and we
study how the non-renormalizable operator case can be described by a slowly
converging effective field theory (EFT) expansion with operators of dimension
five and seven. We show that with O(100) events, one can put strong constraints
on the scale of the EFT, particularly in theories with strong coupling. We also
compare the EFT analysis to that of a UV completion with vector-like quarks,
and outline how the mass of said quarks could be measured.",1607.04276v2
2016-07-20,Dielectric surface loss in superconducting resonators with flux-trapping holes,"Surface distributions of two level system (TLS) defects and magnetic vortices
are limiting dissipation sources in superconducting quantum circuits. Arrays of
flux-trapping holes are commonly used to eliminate loss due to magnetic
vortices, but may increase dielectric TLS loss. We find that dielectric TLS
loss increases by approximately 25% for resonators with a hole array beginning
2 $\mu \text{m}$ from the resonator edge, while the dielectric loss added by
holes further away was below measurement sensitivity. Other forms of loss were
not affected by the holes. Additionally, we estimate the loss due to residual
magnetic effects to be $9\times 10^{-10} /\mu\text{T} $ for resonators
patterned with flux-traps and operated in magnetic fields up to $5$
$\mu\text{T}$. This is orders of magnitude below the total loss of the best
superconducting coplanar waveguide resonators.",1607.05841v2
2016-07-22,Laser and cavity cooling of a mechanical resonator with a Nitrogen-Vacancy center in diamond,"We theoretically analyse the cooling dynamics of a high-Q mode of a
mechanical resonator, when the structure is also an optical cavity and is
coupled with a NV center. The NV center is driven by a laser and interacts with
the cavity photon field and with the strain field of the mechanical oscillator,
while radiation pressure couples mechanical resonator and cavity field.
Starting from the full master equation we derive the rate equation for the
mechanical resonator's motion, whose coefficients depend on the system
parameters and on the noise sources. We then determine the cooling regime, the
cooling rate, the asymptotic temperatures, and the spectrum of resonance
fluorescence for experimentally relevant parameter regimes. For these
parameters, we consider an electronic transition, whose linewidth allows one to
perform sideband cooling, and show that the addition of an optical cavity in
general does not improve the cooling efficiency. We further show that pure
dephasing of the NV center's electronic transitions can lead to an improvement
of the cooling efficiency.",1607.06656v2
2016-07-27,The Role of Multilevel Landau-Zener Interference in Extreme Harmonic Generation,"Motivated by the observation of multiphoton electric dipole spin resonance
processes in InAs nanowires, we theoretically study the transport dynamics of a
periodically driven five-level system, modeling the level structure of a
two-electron double quantum dot. We show that the observed multiphoton
resonances, which are dominant near interdot charge transitions, are due to
multilevel Landau-Zener-Stuckelberg-Majorana interference. Here a third energy
level serves as a shuttle that transfers population between the two resonant
spin states. By numerically integrating the master equation we replicate the
main features observed in the experiments: multiphoton resonances (as large as
8 photons), a robust odd-even dependence, and oscillations in the electric
dipole spin resonance signal as a function of energy level detuning.",1607.08207v1
2016-09-01,Non-Markovian dynamics of a superconducting qubit in an open multimode resonator,"We study the dynamics of a transmon qubit that is capacitively coupled to an
open multimode superconducting resonator. Our effective equations are derived
by eliminating resonator degrees of freedom while encoding their effect in the
Green's function of the electromagnetic background. We account for the
dissipation of the resonator exactly by employing a spectral representation for
the Green's function in terms of a set of non-Hermitian modes and show that it
is possible to derive effective Heisenberg-Langevin equations without resorting
to the rotating wave, two level or Markov approximations. A well-behaved time
domain perturbation theory is derived to systematically account for the
nonlinearity of the transmon. We apply this method to the problem of
spontaneous emission, capturing accurately the non-Markovian features of the
qubit dynamics, valid for any qubit-resonator coupling strength.",1609.00359v3
2016-09-01,Dynamical Screening of $α$-$α$ Resonant Scattering and Thermal Nuclear Scattering Rate in a Plasma,"We use effective field theory and thermal field theory to study the dynamical
screening effect in the QED plasma on the $\alpha$-$\alpha$ scattering at the
$^8$Be resonance. Dynamical screening leads to an imaginary part of the
potential which results in a thermal width for the resonance and dominates over
the previously considered static screening effect. As a result, both the
resonance energy and width increase with the plasma temperature. Furthermore,
dynamical screening can have a huge impact on the $\alpha$-$\alpha$ thermal
nuclear scattering rate. For example, when the temperature is around $10$ keV,
the rate is suppressed by a factor of about $900$. We expect similar thermal
suppressions of nuclear reaction rates to occur in those reactions dominated by
an above threshold resonance with a thermal energy. Dynamical screening effects
on nuclear reactions can be relevant to cosmology and astrophysics.",1609.00383v2
2016-09-19,Polarization-tailored Fano interference in plasmonic crystals: A Mueller matrix model of anisotropic Fano resonance,"We present a simple yet elegant Mueller matrix approach for controlling the
Fano interference effect and engineering the resulting asymmetric spectral line
shape in anisotropic optical system. The approach is founded on a generalized
model of anisotropic Fano resonance, which relates the spectral asymmetry to
two physically meaningful and experimentally accessible parameters of
interference, namely, the Fano phase shift and the relative amplitudes of the
interfering modes. The differences in these parameters between orthogonal
linear polarizations in an anisotropic system are exploited to desirably tune
the Fano spectral asymmetry using pre- and post-selection of optimized
polarization states. Experimental control on the Fano phase and the relative
amplitude parameters and resulting tuning of spectral asymmetry is demonstrated
in waveguided plasmonic crystals using Mueller matrix-based polarization
analysis. The approach enabled tailoring of several exotic regimes of Fano
resonance including the complete reversal of the spectral asymmetry. The
demonstrated control and the ensuing large tunability of Fano resonance in
anisotropic systems shows potential for Fano resonance-based applications
involving control and manipulation of electromagnetic waves at the nano scale.",1609.05777v1
2016-09-21,Force sensitivity of multilayer graphene optomechanical devices,"Mechanical resonators based on low-dimensional materials are promising for
force and mass sensing experiments. The force sensitivity in these ultra-light
resonators is often limited by the imprecision in the measurement of the
vibrations, the fluctuations of the mechanical resonant frequency, and the
heating induced by the measurement. Here, we strongly couple multilayer
graphene resonators to superconducting cavities in order to achieve a
displacement sensitivity of $1.3$ fm Hz$^{-1/2}$. This coupling also allows us
to damp the resonator to an average phonon occupation of $7.2$. Our best force
sensitivity, $390$ zN Hz$^{-1/2}$ with a bandwidth of $200$ Hz, is achieved by
balancing measurement imprecision, optomechanical damping, and heating. Our
results hold promise for studying the quantum capacitance of graphene, its
magnetization, and the electron and nuclear spins of molecules adsorbed on its
surface.",1609.06517v1
2016-09-22,Multiplexing Superconducting Qubit Circuit for Single Microwave Photon Generation,"We report on a device that integrates eight superconducting transmon qubits
in lambda/4 superconducting coplanar waveguide resonators fed from a common
feedline. Using this multiplexing architecture, each resonator and qubit can be
addressed individually thus reducing the required hardware resources and
allowing their individual characterisation by spectroscopic methods. The
measured device parameters agree with the designed values and the resonators
and qubits exhibit excellent coherence properties and strong coupling, with the
qubit relaxation rate dominated by the Purcell effect when brought in resonance
with the resonator. Our analysis shows that the circuit is suitable for
generation of single microwave photons on demand with an efficiency exceeding
80%.",1609.07057v1
2016-10-01,Study of the lowest tensor and scalar resonances in the $τ\to πππν_τ$ decay,"In this note we present a new parametrization of the hadronic current for the
decay $\tau \to \pi\pi\pi \nu_\tau$ derived from the chiral lagrangian with
explicit inclusion of resonances. We have included both scalar, vector and
axial-vector resonances. For the first time, the lowest tensor resonance
($f_2(1270)$) is included as well. Both single and double-resonance
contributions to the hadronic form factors are taken into account. To satisfy
the correct high energy behaviour of the hadronic form factors, constraints on
numerical values of the vertex constants are obtained.",1610.00153v1
2016-10-04,Dependence of the maximal superconducting current on resonance frequency in shunted Josephson junction,"We have investigated the phase dynamics and IV-characteristics of shunted
Josephson junctions coupled to an $LC$ circuit. When the Josephson frequency
$\omega_J$ is close to the eigen frequency $\omega_{rc}$ of the coupled
resonance circuit, the IV-characteristic demonstrates an additional
$rc$-branch. We have investigated the features of the $rc$-branch and of the
superconducting current component for different values of the resonance
frequency. It has been found that the maximal value of the superconducting
current depends on the resonance frequency and that it increases when the end
point of the $rc$-branch approaches the critical current. The dependence of the
maximal superconducting current on the resonance frequency at different values
of the dissipation parameter is peculiar, for the optimized maximum appears to
be independent of the system parameters within $1\%$.",1610.01034v1
2016-10-08,High Quality Stepped-Impedance Resonators Suitable for Circuit-QED Measurement of Superconducting Artificial Atoms,"High quality factor coplanar resonators are critical elements in
superconducting quantum circuits. We describe the design, fabrication and
measurement of stepped impedance resonators (SIRs), which are more compact in
size than commonly used uniform impedance resonators (UIRs). With properly
chosen impedance ratio, SIRs can be 27% shorter than UIRs. As a result, the
area occupied by SIRs can be reduced. Two kinds of designs containing both SIRs
and UIRs are fabricated and measured. The power dependence of the extracted
internal quality factors (Qi) for all the resonators showed that SIRs and UIRs
have comparable performance with Qi around half-million under single-photon
level excitation. These results indicate that SIRs could be used in
superconducting quantum circuits. The reduced size of SIRs may also lead to
reduced overall circuit area and increased integration level.",1610.02474v2
2016-10-11,Resonance poles and threshold energies for hadron physical problems by a model-independent universal algorithm,"We show how complex resonance poles and threshold energies for systems in
hadron physics can be accurately obtained by using a method based on the
Pad\'{e}-approximant which was recently developed for the calculation of
resonance poles for atomic and molecular auto-ionization systems. The main
advantage of this method is the ability to calculate the resonance poles and
threshold energies from \emph{real} spectral data. In order to demonstrate the
capabilities of this method we apply it here to an analytical model as well as
to experimental data for the squared modulus of the vector pion form factor,
the S0 partial wave amplitude for $\pi\pi$ scattering and the cross section
ratio $R(s)$ for $e^+e^-$ collisions. The extracted values for the resonance
poles of the $\rho(770)$ and the $f_0(500)$ or $\sigma$ meson are in very good
agreement with the literature. When the data are noisy the prediction of decay
thresholds proves to be less accurate but feasible.",1610.03252v2
2016-10-20,Selective addressing of solid-state spins at the nanoscale via magnetic resonance frequency encoding,"The nitrogen-vacancy (NV) centre in diamond is a leading platform for
nanoscale sensing and imaging, as well as quantum information processing in the
solid state. To date, individual control of two NV electronic spins at the
nanoscale has been demonstrated. However, a key challenge is to scale up such
control to arrays of NV spins. Here we apply nanoscale magnetic resonance
frequency encoding to realize site-selective addressing and coherent control of
a four-site array of NV spins. Sites in the array are separated by 100 nm, with
each site containing multiple NVs separated by ~15 nm. Microcoils fabricated on
the diamond chip provide electrically tuneable magnetic-field gradients ~0.1
G/nm. Tailored application of gradient fields and resonant microwaves allow
site-selective NV spin manipulation and sensing applications, including Rabi
oscillations, imaging, and nuclear magnetic resonance (NMR) spectroscopy with
nanoscale resolution. Microcoil-based magnetic resonance of solid-state spins
provides a practical platform for quantum-assisted sensing, quantum information
processing, and the study of nanoscale spin networks.",1610.06630v1
2016-10-25,Heavy Higgs boson resonances and their decay into top quarks at the LHC,"We investigate, within the type-II two-Higgs-doublet extension of the
standard model (SM), the impact of heavy neutral Higgs boson resonances with
unsuppressed Yukawa couplings to top quarks on top-quark pair production at the
LHC at next-to-leading order (NLO) in the strong coupling constant. We take
into account the resonant Higgs boson contributions, the non-resonant SM
$t\bar{t}$ continuum and the interference of these two contributions. The NLO
QCD corrections to heavy Higgs production and the interference contributions
are calculated in the large top-quark mass ($m_t$) limit, including an
effective K-factor rescaling. Our evaluation of the QCD-Higgs interference is
focused on the Higgs resonance region. Using representative CP-conserving as
well as CP-violating parameter scenarios phenomenological results are presented
for different observables.",1610.07795v1
2016-10-29,Recent hadronic resonance measurements at ALICE,"In heavy-ion physics, measurements of short-lived hadronic resonances allow
the properties of the hadronic phase of the collision to be studied. In
addition, resonances can be used along with stable hadrons to study parton
energy loss in the quark-gluon plasma and the mechanisms that shape hadron pT
spectra at intermediate transverse momenta. Resonance measurements in small
systems serve as a reference for heavy-ion collisions and contribute to
searches for collective effects. An overview of recent results on hadronic
resonance production measured in ALICE is presented. These results include the
pT spectra and yields of the rho(770)0, K*(892)0, and phi(1020) mesons in pp,
p-Pb, and Pb-Pb collisions at different energies as well as the Sigma(1385)+/-
and Xi(1530)0 baryons in pp and p-Pb collisions.",1610.09529v1
2017-02-04,Ultra-wide plasmonic tuning of semiconductor metasurface resonators on epsilon near zero media,"Fully reconfigurable metasurfaces would enable new classes of optical devices
that provide unprecedented control of electromagnetic beamforms. The principal
challenge for achieving reconfigurability is the need to generate large
tunability of subwavelength, low-Q metasurface resonators. Here, we demonstrate
large refractive index tuning can be efficiently facilitated at mid-infrared
wavelengths using novel temperature-dependent control over free-carrier
refraction. In doped InSb we demonstrate nearly two-fold increase in the
electron effective mass leading to a positive refractive index shift
({\Delta}n>1.5) far greater than conventional thermo-optic effects. In undoped
films we demonstrate more than 10-fold change in the thermal free-carrier
concentration producing a near-unity negative refractive index shift.
Exploiting both effects within a single resonator system, intrinsic InSb wires
on a heavily doped (epsilon near zero) InSb substrate, we demonstrate
dynamically tunable Mie resonances. The observed larger than line-width
resonance shifts ({\Delta}{\lambda}>1.5{\mu}m) suggest new avenues for highly
tunable and reconfigurable mid-infrared semiconductor metasurfaces.",1702.01232v1
2017-02-08,Planets in Mean-Motion Resonances and the System Around HD45364,"In some planetary systems, the orbital periods of two of its members present
a commensurability, usually known by mean-motion resonance. These resonances
greatly enhance the mutual gravitational influence of the planets. As a
consequence, these systems present uncommon behaviors, and their motions need
to be studied with specific methods. Some features are unique and allow us a
better understanding and characterization of these systems. Moreover,
mean-motion resonances are a result of an early migration of the orbits in an
accretion disk, so it is possible to derive constraints on their formation.
Here we review the dynamics of a pair of resonant planets and explain how their
orbits evolve in time. We apply our results to the HD 45365 planetary system.",1702.02494v2
2017-02-09,Wavelength division multiplexed and double-port pumped time-bin entangled photon pair generation using Si ring resonator,"We report a wavelength division multiplexed time-bin entangled photon pair
source in telecom wavelength using a 10 {\mu}m radius Si ring resonator. This
compact resonator has two add ports and two drop ports. By pumping one add port
by a continuous laser, we demonstrate an efficient generation of two-wavelength
division multiplexed time-bin entangled photon pairs in the telecom C-band,
which come out of one drop port, and are then split into the signal and idler
photons via a wavelength filter. The resonator structure enhances four wave
mixing for pair generation. Moreover, we demonstrate the double-port pumping
where two counter propagating pump light are injected to generate entanglement
from the two drop ports simultaneously. We successfully observe the highly
entangled outputs from both two drop ports. Surprisingly, the count rate at
each drop port is even increased by twice as that of the single-port pumping.
Possible mechanisms of this observation are discussed. Our technique allows for
the efficient use of the Si ring resonator, and widens its functionality for
variety of applications.",1702.02659v1
2017-02-09,Compton scattering off proton in the third resonance region,"Compton scattering off the proton in the third resonance region is analyzed
for the first time, owing to the full combined analysis of pion- and
photo-induced reactions in a coupled-channel effective Lagrangian model with
K-matrix approximation. Two isospin $I=3/2$ resonances $D_{33}(1700)$ and
$F_{35}(1930)$ are found to be essential in the range of 1.6 - 1.8 GeV. The
recent beam asymmetry data of Compton scattering from the GRAAL facility are
used to determine the helicity couplings of these resonances, and strong
constraints are coming also from $\pi N$ and $K\Sigma$ photoproduction data.
The possible spin and parity of new narrow resonances is discussed.",1702.02692v3
2017-02-15,Analytical results regarding electrostatic resonances of surface phonon/plasmon polaritons: separation of variables with a twist,"The boundary integral equation method ascertains explicit relations between
localized surface phonon and plasmon polariton resonances and the eigenvalues
of its associated electrostatic operator. We show that group-theoretical
analysis of Laplace equation can be used to calculate the full set of
eigenvalues and eigenfunctions of the electrostatic operator for shapes and
shells described by separable coordinate systems. These results not only unify
and generalize many existing studies but also offer the opportunity to expand
the study of phenomena like cloaking by anomalous localized resonance. For that
reason we calculate the eigenvalues and eigenfunctions of elliptic and circular
cylinders. We illustrate the benefits of using the boundary integral equation
method to interpret recent experiments involving localized surface phonon
polariton resonances and the size scaling of plasmon resonances in graphene
nano-disks. Finally, symmetry-based operator analysis can be extended from
electrostatic to full-wave regime. Thus, bound states of light in the continuum
can be studied for shapes beyond spherical configurations.",1702.04655v1
2017-02-17,Understanding the importance of transient resonances in extreme mass ratio inspirals,"Extreme mass ratio inspirals (EMRIs) occur when a compact object orbits a
much larger one, like a solar-mass black hole around a supermassive black hole.
The orbit has 3 frequencies which evolve through the inspiral. If the orbital
radial frequency and polar frequency become commensurate, the system passes
through a transient resonance. Evolving through resonance causes a jump in the
evolution of the orbital parameters. We study these jumps and their impact on
EMRI gravitational-wave detection. Jumps are smaller for lower eccentricity
orbits; since most EMRIs have small eccentricities when passing through
resonances, we expect that the impact on detection will be small. Neglecting
the effects of transient resonances leads to a loss of ~4% of detectable
signals for an astrophysically motivated population of EMRIs.",1702.05481v1
2017-02-23,Position and Mode Dependent Optical Detection Back-Action in Cantilever Beam Resonators,"Optical detection back-action in cantilever resonant or static detection
presents a challenge when striving for state-of-the-art performance. The origin
and possible routes for minimizing optical back-action have received little
attention in literature. Here, we investigate the position and mode dependent
optical back-action on cantilever beam resonators. A high power heating laser
(100 {\mu}W) is scanned across a silicon nitride cantilever while its effect on
the first three resonance modes is detected via a low-power readout laser (1
{\mu}W) positioned at the cantilever tip. We find that the measured effect of
back-action is not only dependent on position but also the shape of the
resonance mode. Relevant silicon nitride material parameters are extracted by
fitting the temperature-dependent frequency response of the first three modes
to finite element (FE) simulations. In a second round of simulations, using the
extracted parameters, we successfully fit the FEM results with the measured
mode and position dependent back-action. Finally, different routes for
minimizing the effect of this optical detection back-action are described,
allowing further improvements of cantilever-based sensing in general.",1702.07102v1
2017-02-23,Role of a triangle singularity in the $πΔ$ decay of the $N(1700)(3/2^-)$,"We show the important role played by the $\pi\Delta(1232)$ channel in the
build up of the $N(1700)(3/2^-)$ resonance due to the non-trivial enhancement
produced by a singularity of a triangular loop. The $N(1700)$ is one of the
dynamically generated resonances produced by the coupled channel vector-baryon
interaction. The $\pi\Delta$ channel was neglected in previous works but we
show that it has to be incorporated into the coupled channel formalism due to
an enhancement produced by a singularity in the triangular loop with $\rho$,
nucleon and $\pi$ as internal loop lines and $\pi$ and $\Delta$ as external
ones. The enhancement is of non-resonant origin but it contributes to the
dynamical generation of the $N(1700)$ resonance due to the non-linear dynamics
involved in the coupled channel mechanisms. We obtain an important increase of
the total width of the $N(1700)$ resonance when the $\pi\Delta$ channel is
included and provide predictions for the partial widths of the $N(1700)$ decays
into $VB$ and $\pi\Delta$.",1702.07220v1
2017-02-26,Fully coupled-channel complex scaling method for the $K^-pp$ system,"We have developed a fully coupled-channel complex scaling method (ccCSM) for
the study of the most essential kaonic nucleus, $``K^-pp,""$ which is a resonant
state of a $\bar{K}NN$-$\pi\Sigma N$-$\pi\Lambda N$ coupled-channel system
based on a theoretical viewpoint. By employing the ccCSM and imposing the
correct boundary condition of resonance, the coupled-channel problem is
completely solved using a phenomenological energy-independent potential. As a
result of the ccCSM calculation of $``K^-pp,""$ in which all three channels are
treated explicitly, we have obtained three-body resonance as a Gamow state. The
resonance pole indicates that the binding energy of $``K^-pp""$ and the half
value of its mesonic decay width are 51 MeV and 16 MeV, respectively. In the
analysis of the resonant wave function obtained using the ccCSM, we clarify the
spatial configuration and channel compositions of $``K^-pp.""$ Compared with
past studies of single-channel calculations based on effective $\bar{K}N$
potentials, the current study provides a guideline for the determination of the
$\bar{K}N$ energy to be used in effective potentials.",1702.08002v3
2017-03-02,Thermo-optically Reconfigurable PbTe Mie Resonator Meta-atoms,"Subwavelength Mie resonators have enabled new classes of optical antennas1-4,
photodetectors5,6, antireflection coatings7, and magnetic mirrors8 and can act
as the basic meta-atoms constituents of low-loss dielectric
metasurfaces2-4,8-10. In any application, tunable Mie resonances are key to
achieving dynamic and reconfigurable operation11,12. Sub-linewidth tuning has
been achieved via coupling to liquid crystals13, ultrafast free-carrier
injection14,15,16,17, stretchable substrates18 and with phase change
materials19. Here, we demonstrate ultra-wide dynamic tuning of PbTe Mie
resonators fabricated via both laser ablation and a novel solution-processing
approach. Taking advantage of the extremely large thermo-optic (TO) coefficient
and high refractive index of PbTe, we demonstrate high-quality factor
Mie-resonances that are tuned by several linewidths with temperature modulation
as small as {\Delta}T~10K. When combined into metasurface arrays these effects
can be exploited in ultra-narrow active notch filers and metasurface phase
shifters that require only few-kelvin modulation. These findings demonstrate
the enabling potential of thermo-optically tunable PbTe meta-atoms and
metasurfaces.",1703.00886v1
2017-03-06,"Electroexcitation of nucleon resonances of the [70,1-] multiplet in a light-front relativistic quark model","We utilize a light-front relativistic quark model to predict the 3q core
contribution to the electroexcitation of nucleon resonances of the [70,1-]
multiplet on the proton and neutron at Q2 < 5GeV2. The investigation is
stimulated in large degree by expected progress in the studies of the
electroexcitation of nucleon resonances in the third resonance region in the
CLAS experiment. For the resonances N(1520)3/2-, N(1535)1/2-, and N(1675)5/2-,
experimental data on electroexcitation amplitudes on the proton are available
in a wide range of Q2. This allowed us to quantify the expected meson-baryon
contributions to these amplitudes as a function of Q2.",1703.01751v1
2017-03-16,Exotic states in the strong field control of H$_2^+$ dissociation dynamics: From exceptional points to zero-width resonances,"H$_2^+$ is an ideal candidate for a detailed study of strong field coherent
control strategies inspired by basic mechanisms referring to some specific
photodissociation resonances. Two of them are considered in this work, namely:
Zero-width resonances (ZWR) on one hand, and coalescing pairs of resonances at
exceptional points (EP) on the other hand. An adiabatic transport theory based
on Floquet Hamiltonian formalism is developed within the challenging context of
multiphoton dynamics involving nuclear continua. It is shown that a rigorous
treatment is only possible for ZWRs, whereas adiabatic transport mediated by
EPs is subjected to restrictions. Numerical maps of resonance widths and
non-adiabatic couplings in the laser parameter plane help in optimally shaping
control pulses. Full time-dependent wavepacket dynamics shows the possibility
of selective, robust filtration and vibrational population transfers, within
experimental feasibility criteria.",1703.05618v2
2017-03-18,Resonance a_1(1420) and the Three-Pion Decays of the Tauon,"The role of the a_1(1420) resonance in the three-pion decays of the tau
lepton is investigated using a phenomenological model. For all data before
2008, roughly equal fit quality is achieved when the basic a_1(1260) resonance
is supplemented with either a_1(1640) or a_1(1420). However, two recent and
more precise data sets require resonances with masses that are not very far
from that of a_1(1420). This suggests that the axial-vector resonance that
accompanies the a_1(1260) in the three-pion decays of the tauon is a_1(1420),
not a_1(1640), as believed up to now. More data are needed to demonstrate this
definitely.",1703.06315v2
2017-03-28,Resonant photoluminescence and dynamics of a hybrid Mn-hole spin in a positively charged magnetic quantum dot,"We analyze, through resonant photoluminescence, the spin dynamics of an
individual magnetic atom (Mn) coupled to a hole in a semiconductor quantum dot.
The hybrid Mn-hole spin and the positively charged exciton in a CdTe/ZnTe
quantum dot forms an ensemble of $\Lambda$ systems which can be addressed
optically. Auto-correlation of the resonant photoluminescence and resonant
optical pumping experiments are used to study the spin relaxation channels in
this multilevel spin system. We identified for the hybrid Mn-hole spin an
efficient relaxation channel driven by the interplay of the Mn-hole exchange
interaction and the coupling to acoustic phonons. We also show that the optical
$\Lambda$ systems are connected through inefficient spin-flips than can be
enhanced under weak transverse magnetic field. The dynamics of the resonant
photoluminescence in a p-doped magnetic quantum dot is well described by a
complete rate equation model. Our results suggest that long lived hybrid
Mn-hole spin could be obtained in quantum dot systems with large
heavy-hole/light-hole splitting.",1703.09441v2
2017-08-14,Stability and secondary resonances in the spatial restricted three-body problem for small mass ratios,"This paper is devoted to the study of secondary resonances and the stability
of the Lagrangian point L4 in the spatial restricted three-body problem for
moderate mass ratios (mu), meaning that mu is smaller than 0.0045. However, we
concentrated our investigations on small mass ratios for mu smaller than 0.001,
which represent the mass ratios for stable configurations of tadpole orbits in
the Solar system. The stability is investigated by numerical methods, computing
stability maps in different parameter planes. We started investigating the mass
of the secondary; from Earth-mass bodies up to Jupiter-mass bodies. In addition
we changed the orbital elements (eccentricity and inclination) of the secondary
and Trojan body. For this parameter space we found high order secondary
resonances, which are present for various inclinations. To determine secondary
resonances we used Rabe's equation and the frequency analysis. In addition we
investigated the stability in and around these secondary resonances.",1708.04039v1
2017-08-19,Multiresonator quantum memory-interface,"In this paper we experimentally demonstrated a broadband microwave scheme
suitable for the multiresonator quan- tum memory-interface. The microwave
scheme consists of the system of composed mini-resonators strongly inter-
acting with a common broadband resonator coupled with the external microwave
waveguide. We have implemented the controllable tuning of the mini-resonator
frequencies and coupling of the common resonator with the external waveguide
for the implementation of the impedance matched quantum storage. The storage of
microwave pulses with an efficiency of 16.3% has been shown experimentally at
room temperature. The possible properties of the proposed scheme for
mini-resonators with high-Q at low temperatures are discussed. The obtained
results pave the way for the implementation of superefficient broadband
microwave quantum memory-interface.",1708.05814v1
2017-08-26,Subwavelength and directional control of flexural waves in zone-folding induced topological plates,"Inspired by the quantum spin Hall effect shown by topological insulators, we
propose a plate structure that can be used to demonstrate the pseudo-spin Hall
effect for flexural waves. The system consists of a thin plate with
periodically arranged resonators mounted on its top surface. We extend a
technique based on the plane wave expansion method to identify a double Dirac
cone emerging due to the zone-folding in frequency band structures. This
particular design allows us to move the double Dirac cone to a lower frequency
than the resonating frequency of local resonators. We then manipulate the
pattern of local resonators to open subwavelength Bragg band gaps that are
topologically distinct. Building on this method, we verify numerically that a
waveguide at an interface between two topologically distinct resonating plate
structures can be used for guiding low-frequency, spin-dependent one-way
flexural waves along a desired path with bends.",1708.07994v2
2018-01-31,The spectrum of non-centrosymmetrically layered spherical cavity resonator. I.The mode decomposition method,"We develop a theoretical method for solving Maxwell's equations to obtain the
frequency spectra of inhomogeneous and asymmetric cavity resonators using a
couple of effective Debye-type potentials. The structure we study specifically
is the layered spherical cavity resonator with symmetrically or asymmetrically
inserted inner dielectric sphere. The comparison of the exact numerical results
obtained for the frequency spectrum of layered cavity resonator with
centrosymmetrically inserted sphere and the spectrum found from the suggested
theory reveals good agreement at the initial part of the frequency axis. The
coincidence accuracy depends on the number of trial resonant modes that we use
while approving our method numerically.",1802.00505v1
2018-02-16,Search for narrow resonances in the b-tagged dijet mass spectrum in proton-proton collisions at $\sqrt{s} =$ 8 TeV,"A search for narrow resonances decaying to bottom quark-antiquark pairs is
presented, using a data sample of proton-proton collisions at $\sqrt{s} =$ 8
TeV corresponding to an integrated luminosity of 19.7 fb$^{-1}$. The search is
extended to masses lower than those reached in typical searches for resonances
decaying into jet pairs at the LHC, by taking advantage of triggers that
identify jets originating from bottom quarks. No significant excess of events
is observed above the background predictions. Limits are set on the product of
cross section and branching fraction to bottom quarks for spin 0, 1, and 2
resonances in the mass range of 325-1200 GeV. These results significantly
improve on the limits for resonances decaying into jet pairs in the 325-500 GeV
mass range.",1802.06149v2
2018-02-27,Terahertz whispering gallery mode bubble resonator,"Whispering gallery mode (WGM) resonators are compelling optical devices,
however they are nearly unexplored in the terahertz (THz) domain. In this
letter, we report on THz WGMs in quartz glass bubble resonators with
sub-wavelength wall thickness. An unprecedented study of both the amplitude and
phase of THz WGMs is presented. The coherent THz frequency domain measurements
are in excellent agreement with a simple analytical model and results from
numerical simulations. A high finesse of 9 and a quality (Q) factor exceeding
440 at 0.47 THz are observed. Due to the large evanescent field the high
Q-factor THz WGM bubble resonators can be used as a compact, highly sensitive
sensor in the intriguing THz frequency range.",1802.10195v1
2018-04-01,Resonance states near a quantum magnetic impurity in single-layer FeSe superconductors with $d$-wave symmetry,"In this work, we investigate the local density of states (LDOS) near a
magnetic impurity in single-layer FeSe superconductors. The two-orbital model
with spin-orbit coupling proposed in Ref. [{\emph{Phys. Rev. Lett.}
\textbf{119}, 267001 (2017)}] is used to describe the FeSe superconductor. In
the strong coupling regime, two impurity resonance peaks appear with opposite
resonance energies in the LDOS spectral function. For a strong spin-orbit
coupling, the superconducting gap in this model is $d$-wave symmetric with
nodes, the spatial distributions of the LDOS at the two resonance energies are
fourfold symmetric, which reveals typical characteristic of $d$-wave pairing.
When the spin-orbit coupling is not strong enough to close the superconducting
gap, we find that the spatial distribution of the LDOS at one of the resonance
energies manifests $s$-wave symmetry, while the pairing potential preserves
$d$-wave symmetry. This result is consistent with previous experimental
investigations.",1804.00258v1
2018-04-09,How to Synthesize Exceptional Points with Three Resonators,"In non-Hermitian coulped-resonator networks, the eigenvectors of degenerate
eigenmodes may become parallel due to the singularity at so-called Exceptional
Points (EP). To exploit the parametric sensitivity at EPs, an important problem
is, given an arbitrary set of coupled resonators, how to generate a desired EP
by properly coupling them together. This paper provides the solution for the
case of three resonators. We show that all physically admissible EPs can be
realized with either weakly coupled linear networks or strongly coupled
circular networks, and the latter type of EPs has not been reported in the
literature. Each admissible EP eigenvalue can be realized by two and only two
resonator networks, and the formulas for calculating the required coupling
constants are provided. The characteristics of these EPs are illustrated by the
change of transmission spectra near them, which verify the enhanced sensitivity
induced by the singularity of EPs.",1804.03041v1
2018-04-20,Frequency-temperature relations of novel cuts of quartz crystals for thickness-shear resonators,"In a recent study, we have reported that there are many novel cuts of quartz
crystal exhibiting the highly treasured cubic frequency-temperature relations
which are currently shown only with the AT- and SC-cut. Through setting the
first- and second-order derivatives of the frequency respect to temperature to
zeroes, a family of quartz crystal cuts with different temperatures of zero
frequency (turnover temperatures) has been found and examined. It is now
possible to fabricate quartz crystal resonators with turnover temperature near
its operating temperature to keep the resonator functioning in a lean and more
natural state. By selecting a few cuts based on orientations from our study, we
analyzed the thickness-shear vibrations of quartz crystal plates to confirm the
superior frequency-temperature relations with the theory of incremental thermal
field and Mindlin plate equations and presenting comparisons with known AT- and
SC-cut to demonstrate that resonators with newly found cuts can also achieve
exceptional frequency stability as demanded.",1804.07432v1
2018-04-26,Resonant reflection of interacting electrons from an impurity in a quantum wire: interplay of Zeeman and spin-orbit effects,"A single-channel quantum wire with two well-separated Zeeman subbands and in
the presence of a weak spin-orbit coupling is considered. An impurity level
which is split off the upper subband is degenerate with the continuum of the
lower subband. We show that, when the Fermi level lies in the vicinity of the
impurity level, the transport is completely blocked. This is the manifestation
of the effect of resonant reflection and can be viewed as resonant tunneling
between left-moving and right-moving electrons via the impurity level. We
incorporate electron-electron interactions and study their effect on the shape
of the resonant-reflection profile. This profile becomes a two-peak structure,
where one peak is caused by resonant reflection itself, while the origin of the
other peak is reflection from the Friedel oscillations of the electron density
surrounding the impurity.",1804.10283v1
2018-11-02,Splitting of conductance resonance through a magnetic quantum dot in graphene,"We report a dual resonance feature in ballistic conductance through a quantum
Hall graphene nanoribbon with a magnetic quantum dot. Such a magnetic quantum
dot localizes Dirac fermions exhibiting anisotropic eigenenergy spectra with
broken time-reversal symmetry. Interplay between the localized states and
quantum Hall edge states is found to be two-fold, showing Breit-Wigner and Fano
resonances, which is reminiscent of a double quantum dot system. By fitting the
numerical results with the Fano-Breit-Wigner lineshape from the double quantum
dot model, we demonstrate that the two-fold resonance is due to the valley
mixing that comes from the coupling of the magnetic quantum dot with quantum
Hall edge channels; an effective double quantum dot system emerges from a
single magnetic quantum dot in virtue of the valley degree of freedom. It is
further confirmed that the coupling is weaker for the Fano resonance and
stronger for the Breit-Wigner resonace.",1811.00750v1
2018-11-12,Dynamic aperture limitation in $e^+e^-$ colliders due to synchrotron radiation in quadrupoles,"In a lepton storage ring of very high energy (e.g. in the $e^+e^-$ Higgs
factory) synchrotron radiation from quadrupoles constrains transverse dynamic
aperture even in the absence of any magnetic nonlinearities. This was observed
in tracking for LEP and the Future Circular $e^+e^-$ Collider (FCC-ee). Here we
describe a new mechanism of instability created by modulation of the particle
energy at the double betatron frequency by synchrotron radiation in the
quadrupoles. Energy modulation varies transverse focusing strength at the same
frequency and creates a parametric resonance of the betatron oscillations with
unusual properties. It occurs at arbitrary betatron frequency (the resonant
detuning is always zero) and the magnitude of the parameter modulation of the
betatron oscillation (strength of the resonance driving term) depends on the
oscillation amplitude. Equilibrium between the radiation damping and the
resonant excitation gives the boundary of the stable motion. Starting from 6d
equations of motion we derive and solve the relevant differential equation
describing the resonance, and show good agreement between analytical results
and numerical simulation.",1811.04554v1
2018-11-23,Spatial resonant periodic orbits in the restricted three-body problem,"The quest of exo-Earths has become a prominent field. In this work, we study
the stability of non-coplanar planetary configurations consisting of an
inclined inner terrestrial planet in mean-motion resonance with an outer giant
planet. We examine the families of circular and elliptic symmetric periodic
orbits with respect to the vertical stability, and identify the vertical
critical orbits from which the spatial families emanate. We showcase that
stable spatial periodic orbits can exist for both prograde and retrograde
motion in 3/2, 2/1, 5/2, 3/1, 4/1 and 5/1 resonances for broad ranges of
inclinations, when the giant evolves on a circular orbit. When the orbit of the
giant is elliptic, only the 2/1 resonance has stable periodic orbits up to high
inclinations, while the 3/1, 4/1 and 5/1 resonances possess segments of
stability for low inclinations. Furthermore, we show that regular motion can
also take place in the vicinity of both horizontally and vertically stable
planar periodic orbits, even for very high inclinations. Finally, the results
are discussed in the context of asteroid dynamics.",1811.09442v2
2018-11-30,"Isovector scalar $a_0(980)$ and $a_0(1450)$ resonances in the $B\rightarrow ψ(K\bar{K},πη) $ decays","We present an analysis of two isovector scalar resonant contributions to the
$B$ decays into charmonia plus $K\bar K$ or $\pi\eta$ pair in the perturbative
QCD approach. The Flatt\'{e} model for the $a_0(980)$ resonance and the Breit
Wigner formula for the $a_0(1450)$ resonance are adopted to parametrize the
timelike form factors in the dimeson distribution amplitudes, which capture the
important final state interactions in these processes. The predicted
distribution in the $K^+K^-$ invariant mass as well as its integrated branching
ratio for the $a_0(980)$ resonance in the $B^0\rightarrow J/\psi K^+K^-$ mode
agree well with the current available experimental data. The obtained branching
ratio of the quasi-two-body decay $B^0\rightarrow J/\psi a_0(980)(\rightarrow
\pi^0\eta)$ can reach the order of $10^{-6}$, letting the corresponding
measurement appear feasible. For the $a_0(1450)$ component, our results could
be tested by further experiments in the LHCb and Belle II. We also discuss some
theoretical uncertainties in detail in our calculation.",1811.12738v2
2019-05-05,Exceptional points for resonant states on parallel circular dielectric cylinders,"Exceptional points (EPs) are special parameter values of a non-Hermitian
eigenvalue problem where eigenfunctions corresponding to a multiple eigenvalue
coalesce. In optics, EPs are associated with a number of counter-intuitive wave
phenomena, and have potential applications in lasing, sensing, mode conversion
and spontaneous emission processes. For open photonic structures, resonant
states are complex-frequency solutions of the Maxwell's equations with outgoing
radiation conditions. For open dielectric structures without material gain or
loss, the eigenvalue problem for resonant states can have EPs, since it is
non-Hermitian due to radiation losses. For applications in nanophotonics, it is
important to understand EPs for resonant states on small finite dielectric
structures consisting of conventional dielectric materials. To achieve this
objective, we study EPs of resonant states on finite sets of parallel
infinitely-long circular dielectric cylinders with subwavelength radii. For
systems with two, three and four cylinders, we develop an efficient numerical
method for computing EPs, present examples for second and third order EPs, and
highlight their topological features. Our work provides insight to
understanding EPs on more complicated photonic structures, and can be used as a
simple platform to explore applications of EPs.",1905.01572v1
2019-05-10,Resonant orbits for a spinning particle in Kerr spacetime,"In the present article, we study the orbital resonance corresponds to an
extended object approximated up to the dipole order term in Kerr spacetime. We
start with the Mathisson-Papapetrou equations under the linear spin
approximation and primarily concentrate on two particular events. First, when
the orbits are nearly circular and executing a small oscillation about the
equatorial plane and second, a generic trajectory confined on the equatorial
plane. While in the first case, all the three fundamental frequencies, namely,
radial $\Omega_r$, angular $\Omega_{\theta}$, azimuthal $\Omega_{\phi}$ can be
commensurate with each others and give rise to the resonance phenomenon, the
later is only accompanied with the resonance between $\Omega_r$ and
$\Omega_{\phi}$ as we set $\theta=\pi/2$. We provide a detail derivation in
locating the prograde resonant orbits in either of these cases and also study
the role played by the spin of the black hole. The implications related to
spin-spin interactions between the object and black hole are also demonstrated.",1905.04061v2
2019-05-13,Interaction between coaxial dielectric disks enhances the Q-factor,"We study the behavior of resonant modes under variation of the distance
between two coaxial dielectric disks and show an avoided crossing of resonances
because of interaction between the disks. Owing to coaxial arrange of disks the
consideration is separated by the azimuthal index $m=0, 1, 2, \ldots$. In the
present paper we consider the case $m=0$. For a long enough distance the
resonant modes can be classified as symmetric and antisymmetric hybridizations
of the resonant modes of the isolated disk. With decreasing of the distance the
interaction becomes stronger that gives rise to avoided crossing of different
resonances of the isolated disk. That in turn enhances the $Q$ factor of two
disks by one order in magnitude compared to the $Q$ factor of isolated disk.",1905.04856v1
2019-05-15,Statistical properties of thermal neutron capture cross section calculated with randomly generated resonance parameters,"We investigated the probability distribution of the thermal neutron capture
cross section ($\sigma_{th}$) deduced stochastically with the resonance
parameters randomly sampled from Wigner and Porter-Thomas distributions. We
found that the typical probability distribution has an asymmetric shape. While
there is a long tail on the large $\sigma_{th}$ side due to a resonance
happening to be close to the thermal energy, the multi-resonance contribution
considerably reduces the probability on the small $\sigma_{th}$ side. We also
found that the probability distributions have a similar shape if nuclei have an
average resonance spacing sufficiently larger than an average radiation width.
We compared the typical probability distribution with the distribution of the
experimental values of 193 nuclei, and found a good agreement between them.",1905.06096v1
2019-05-12,Relation Between Solutions of the Schrödinger Equation with Transitioning Resonance Solutions of the Gravitational Three-Body Problem,"It is shown that a class of approximate resonance solutions in the three-body
problem under the Newtonian gravitational force are equivalent to quantized
solutions of a modified Schr\""odinger equation for a wide range of masses that
transition between energy states. In the macroscopic scale, the resonance
solutions are shown to transition from one resonance type to another through
weak capture at one of the bodies, while in the Schr\""odinger equation, one
obtains quantized wave solutions transitioning between different energies. The
resonance transition dynamics provides a classical model of a particle moving
between different energy states in the Schr\""odinger equation. This methodology
provides a connection between celestial and quantum mechanics.",1905.06705v2
2019-05-17,Manifestation of the Purcell effect in current transport through a dot-cavity-QED system,"We study the transport properties of a wire-dot system coupled to a cavity
and a photon reservoir. Tuning the photon energy, Rabi-resonant states emerge
and in turn resonant current peaks are observed. We demonstrate the effects of
the cavity-photon reservoir coupling, the mean photon number in the reservoir,
the electron-photon coupling and the photon polarization on the intraband
transitions occurring between the Rabi-resonant states, and on the
corresponding resonant current peaks. The Rabi-splitting can be controlled by
the photon polarization and the electron-photon coupling strength. In the
selected range of parameters, we observe the results of the Purcell effect
enhancing the current peaks through the cavity by increasing the
cavity-reservoir coupling, while they decrease with increasing the
electron-photon coupling. In addition, the resonant current peaks are also
sensitive to the mean number of photons in the reservoir.",1905.07492v1
2019-05-20,Large enhancement of the thermoelectric power factor in disordered materials through resonant scattering,"In the search for more efficient thermoelectric materials, scientists have
placed high hopes in the possibility of enhancing the power factor using
resonant states. In this study, we investigate theoretically the effects of
randomly distributed resonant impurities on the power factor. Using the
Chebyshev Polynomial Green's Function method, we compute the electron transport
properties for very large systems (10 million atoms) with an exact treatment of
disorder. The introduction of resonant defects can lead to a large enhancement
of the power factor together with a sign inversion in the Seebeck coefficient.
This boost depends crucially on the position of the resonant peak, and on the
interplay between elastic impurity scattering and inelastic processes. Strong
electron-phonon or electron-electron scattering are found detrimental. Finally,
the robustness of our results is examined in the case of anisotropic orbitals
and two-dimensional confinement. Our findings are promising for the prospect of
thermoelectric power generation.",1905.08172v1
2019-05-21,On liners viscoacoustic impedance boundary conditions for an array of Helmholtz resonators in 3D,"The present work deals with the resolution of the Linearized Navier-Stokes
problem in a domain made of an array that consists into a repetition of
elongated resonators connected to an half-space. We provide and justify a limit
equivalent model which takes into account the presence of resonators array as
an equivalent boundary condition. Our approach combines the method of matched
asymptotic expansions and the method of periodic surface homogenization adapted
to more than two scales, and a complete justification is included in the paper.",1905.08566v2
2019-05-21,Single-particle Mie-resonant all-dielectric nanolasers,"All-dielectric subwavelength structures utilizing Mie resonances provide a
novel paradigm in nanophotonics for controlling and manipulating light. So far,
only spontaneous emission enhancement was demonstrated with single dielectric
nanoantennas, whereas stimulated emission was achieved only in large lattices
supporting collective modes. Here, we demonstrate the first single-particle
all-dielectric monolithic nanolaser driven by Mie resonances in visible and
near-IR frequency range. We employ halide perovskite CsPbBr$_3$ as both gain
and resonator material that provides high optical gain (up to $\sim 10^4$
cm$^{-1}$) and allows simple chemical synthesis of nanocubes with nearly
epitaxial quality. Our smallest non-plasmonic Mie-resonant single-mode
nanolaser with the size of 420 nm operates at room temperatures and wavelength
535 nm with linewidth $\sim 3.5$ meV. These novel lasing nanoantennas can pave
the way to multifunctional photonic designs for active control of light at the
nanoscale.",1905.08646v1
2019-05-29,Instabilities in Multi-Planet Circumbinary Systems,"The majority of the discovered transiting circumbinary planets are located
very near the innermost stable orbits permitted, raising questions about the
origins of planets in such perturbed environments. Most favored formation
scenarios invoke formation at larger distances and subsequent migration to
their current locations. Disk-driven planet migration in multi-planet systems
is likely to trap planets in mean motion resonances and drive planets inward
into regions of larger dynamical perturbations from the binary. We demonstrate
how planet-planet resonances can interact with the binary through secular
forcing and mean-motion resonances, driving chaos in the system. We show how
this chaos will shape the architecture of circumbinary systems, with specific
applications to Kepler 47 and the Pluto-Charon system, limiting maximum
possible stable eccentricities and indicating what resonances are likely to
exist. We are also able to constrain the minimum migration rates of resonant
circumbinary planets.",1905.12638v1
2020-07-08,Variational solutions for Resonances by a Finite-Difference Grid Method,"We demonstrate that the finite difference grid method (FDM) can be simply
modified to satisfy the variational principle and enable calculations of both
real and complex poles of the scattering matrix. These complex poles are known
as resonances and provide the energies and inverse lifetimes of the system
under study (e.g., molecules) in metastable states. This approach allows
incorporating finite grid methods in the study of resonance phenomena in
chemistry. Possible applications include the calculation of electronic
autoionization resonances which occur when ionization takes place as the bond
lengths of the molecule are varied. Alternatively, the method can be applied to
calculate nuclear predissociation resonances which are associated with
activated complexes with finite lifetimes.",2007.04049v3
2020-07-09,Dynamical taxonomy of the coupled solar radiation pressure and oblateness problem and analytical deorbiting configurations,"Recent works demonstrated that the dynamics caused by the planetary
oblateness coupled with the solar radiation pressure can be described through a
model based on singly-averaged equations of motion. The coupled perturbations
affect the evolution of the eccentricity, inclination and orientation of the
orbit with respect to the Sun--Earth line. Resonant interactions lead to
non-trivial orbital evolution that can be exploited in mission design.
Moreover, the dynamics in the vicinity of each resonance can be analytically
described by a resonant model that provides the location of the central and
hyperbolic invariant manifolds which drive the phase space evolution. The
classical tools of the dynamical systems theory can be applied to perform a
preliminary mission analysis for practical applications. On this basis, in this
work we provide a detailed derivation of the resonant dynamics, also in
non-singular variables, and discuss its properties, by studying the main
bifurcation phenomena associated to each resonance. Last, the analytical model
will provide a simple analytical expression to obtain the area-to-mass ratio
required for a satellite to deorbit from a given altitude in a feasible
timescale.",2007.04945v2
2020-07-05,Compact Ring Resonator Enhanced Silicon-MSM Photodetector in SiN-on-SOI Platform,"We present a compact on-chip resonator enhanced silicon-MSM photodetector in
$850$ $nm$ wavelength band for communication and lab-on-chip bio-sensing
applications. We report the highest responsivity of 0.81 A/W for a 5 $\mu m$
long device. High responsivity is achieved by integrating the detector in a
silicon nitride ring resonator. The resonance offers 100X responsivity
improvement over a single-pass photodetector due to cavity enhancement. We also
present a detailed study of the high-speed response of the cavity and
single-pass detector. We report an electro-optic bandwidth of 7.5 GHz measured
using a femtosecond optical excitation. To the best of our knowledge, we report
for the first time silicon nitride resonator integrated Si-MSM detector in
SiN-SOI platform.",2007.05024v1
2020-07-14,Comparison of Dielectric Loss in Titanium Nitride and Aluminum Superconducting Resonators,"Lossy dielectrics are a significant source of decoherence in superconducting
quantum circuits. In this report, we model and compare the dielectric loss in
bulk and interfacial dielectrics in titanium nitride (TiN) and aluminum (Al)
superconducting coplanar waveguide (CPW) resonators. We fabricate isotropically
trenched resonators to produce a series of device geometries that accentuate a
specific dielectric region's contribution to resonator quality factor. While
each dielectric region contributes significantly to loss in TiN devices, the
metal-air interface dominates the loss in the Al devices. Furthermore, we
evaluate the quality factor of each TiN resonator geometry with and without a
post-process hydrofluoric (HF) etch, and find that it reduced losses from the
substrate-air interface, thereby improving the quality factor.",2007.07338v1
2020-07-23,Determination of carrier density and dynamics via magneto-electroluminescence spectroscopy in resonant tunneling diodes,"We study the magneto-transport and magneto-electroluminescence properties of
purely n-doped GaAs/Al$_{0.6}$Ga$_{0.4}$As resonant tunneling diodes with an
In$_{0.15}$Ga$_{0.85}$As quantum well and emitter prewell. Before the resonant
current condition, magneto-transport measurements reveal charge carrier
densities comparable for diodes with and without the emitter prewell. The
Landau level splitting is observed in the electroluminescence emission from the
emitter prewell, enabling the determination of the charge carrier build-up. Our
findings show that magneto-electroluminescence spectroscopy techniques provide
useful insights on the charge carrier dynamics in resonant tunneling diodes and
is a versatile tool to complement magneto-transport techniques. This approach
will drive the way for developing potentially more efficient opto-electronic
resonant tunneling devices, by e.g., monitoring voltage dependent charge
accumulation for improving built-in fields and hence to maximize photodetector
efficiency and/or minimize optical losses.",2007.11736v2
2020-07-28,Dynamical Zeeman resonance in spin-orbit-coupled spin-1 Bose gases,"We predict a dynamical resonant effect, which is driven by externally applied
linear and quadratic Zeeman fields, in a spin-orbit-coupled spin-1
Bose-Einstein condensate. The Bose-Einstein condensate is assumed to be
initialized in some superposed state of Zeeman sublevels and subject to a
sudden shift of the trapping potential. It is shown that the time-averaged
center-of-mass oscillation and the spin polarizations of the Bose-Einstein
condensate exhibit remarkable resonant peaks when the Zeeman fields are tuned
to certain strengths. The underlying physics behind this resonance can be
traced back to the out-of-phase interference of the dynamical phases carried by
different spinorbit states. By analyzing the single particle spectrum, the
resonant condition is summarized as a simple algebraic relation, connecting the
strengths of the linear and quadratic Zeeman fields. This property is
potentially applicable in quantum information and quantum precision
measurement.",2007.14131v1
2020-07-30,"Asteroid impact, Schumann resonances and the end of dinosaurs","We estimate the expected magnitudes of the Schumann resonance fields
immediately after the Chicxulub impact and show that they exceed their
present-day values by about $5\times 10^4$ times. Long-term distortion of the
Schumann resonance parameters is also expected due to the enviromental impact
of the Chicxulub event. If Schumann resonances play a regulatory biological
role, as some studies indicate, it is possible that the excitation and
distortion of Schumann resonances as a result of the asteroid/comet impact was
a possible stress factor, which, among other stress factors associated with the
impact, contributed to the demise of dinosaurs.",2007.15463v2
2020-07-31,Suppression of Three-Body Loss Near a p-Wave Resonance Due to Quasi-1D Confinement,"We investigate the three-body recombination rate of a Fermi gas of $^6$Li
atoms confined in quasi-1D near a $p$-wave Feshbach resonance. We confirm that
the quasi-1D loss rate constant $K_3$ follows the predicted threshold scaling
law that $K_3$ is energy independent on resonance, and find consistency with
the scaling law $K_3 \propto (k \, a_{1D})^6$ far from resonance [Mehta et al.
Phys. Rev. A 76, 022711 (2007)]. Further we develop a theory based on
Breit-Wigner analysis that describes the loss feature for intermediate fields.
Lastly we measure how the loss rate constant scales with transverse confinement
and find that $K_3 \propto V_L^{-1}$, where $V_L$ is the lattice depth.
Importantly, at our attainable transverse confinements and temperatures, we see
a 74-fold suppression of the on-resonant three-body loss rate constant in
quasi-1D compared to 3D. With significant further enhancement of the transverse
confinement, this suppression may pave the way for realizing stable $p$-wave
superfluids.",2007.15783v1
2010-05-04,Effect of disorder studied with ferromagnetic resonance for arrays of tangentially magnetized sub-micron Permalloy discs fabricated by nanosphere lithography,"Tangentially magnetized trigonal arrays of sub-micron Permalloy discs are
characterized with ferromagnetic resonance to determine the possible
contributions to frequency and linewidth from array disorder. Each array is
fabricated by a water-surface self-assembly lithographic technique, and
consists of a large trigonal array of 700 nm diameter magnetic discs. Each
array is characterized by a different degree of ordering. Two modes are present
in the ferromagnetic resonance spectra: a large amplitude, `fundamental' mode
and a lower amplitude mode at higher field. Angular dependence of the resonance
field in a very well ordered array is found to be negligible for both modes.
The relationship between resonance frequency and applied magnetic field is
found to be uncorrelated with array disorder. Linewidth is found to increase
with increasing array disorder.",1005.0452v3
2010-05-17,Experimental demonstration of higher-order Laguerre-Gauss mode interferometry,"The compatibility of higher-order Laguerre-Gauss (LG) modes with
interferometric technologies commonly used in gravitational wave detectors is
investigated. In this paper we present the first experimental results
concerning the performance of the LG33 mode in optical resonators. We show that
the Pound-Drever-Hall error signal for a LG33 mode in a linear optical
resonator is identical to that of the more commonly used LG00 mode, and
demonstrate the feedback control of the resonator with a LG33 mode. We
succeeded to increase the mode purity of a LG33 mode generated using a
spatial-light modulator from 51% to 99% upon transmission through a linear
optical resonator. We further report the experimental verification that a
triangular optical resonator does not transmit helical LG modes.",1005.2990v3
2013-08-05,From Resonant to Broadband Searches for WISPy Cold Dark Matter,"Dark matter may consist of light, very weakly interacting bosons, produced
non-thermally in the early Universe. Prominent examples of such very weakly
interacting slim particles (WISPs) are axions and hidden photons. Direct
detection experiments for such particles are based on the conversion of these
particles into photons. This can be done in resonant cavities, featuring a
resonant enhancement, or by using suitably shaped reflecting surfaces that
allow for broadband searches. In this note we want to elucidate the relation
between the two setups and study the transition from resonant to broadband
searches. This then allows to determine the sensitivity of off-resonance cavity
searches for cavities much larger than the wavelength of the generated photons.",1308.1103v1
2013-08-08,Full counting statistics and phase diagram of a dissipative Rydberg gas,"Ultra-cold gases excited to strongly interacting Rydberg states are a
promising system for quantum simulations of many-body systems. For off-resonant
excitation of such systems in the dissipative regime, highly correlated
many-body states exhibiting, among other characteristics, intermittency and
multi-modal counting distributions are expected to be created. So far,
experiments with Rydberg atoms have been carried out in the resonant,
non-dissipative regime. Here we realize a dissipative gas of rubidium Rydberg
atoms and measure its full counting statistics for both resonant and
off-resonant excitation. We find strongly bimodal counting distributions in the
off-resonant regime that are compatible with intermittency due to the
coexistence of dynamical phases. Moreover, we measure the phase diagram of the
system and find good agreement with recent theoretical predictions. Our results
pave the way towards detailed studies of many-body effects in Rydberg gases.",1308.1854v1
2013-08-09,Coulomb-assisted cavity feeding in the non-resonant optical emission from a quantum dot,"Recent experiments have demonstrated that for a quantum dot in an optical
resonator off-resonant cavity mode emission can occur even for detunings of the
order of 10 meV. We show that Coulomb mediated Auger processes based on
additional carriers in delocalized states can facilitate this far off-resonant
emission. Using a novel theoretical approach for a non-perturbative treatment
of the Auger-assisted quantum-dot carrier recombination, we present numerical
calculations of the far off-resonant cavity feeding rate and cavity mean photon
number confirming efficient coupling at higher densities of carriers in the
delocalized states. In comparison to fast Auger-like intraband scattering
processes, we find a reduced overall efficiency of Coulomb-mediated interband
transitions due the required electron-hole correlations for the recombination
processes.",1308.2080v2
2013-08-29,Coherently opening a high-Q cavity,"We propose a general framework to effectively `open' a high-Q resonator, that
is, to release the quantum state initially prepared in it in the form of a
traveling electromagnetic wave. This is achieved by employing a mediating mode
that scatters coherently the radiation from the resonator into a
one-dimensional continuum of modes such as a waveguide. The same mechanism may
be used to `feed' a desired quantum field to an initially empty cavity.
Switching between an `open' and `closed' resonator may then be obtained by
controlling either the detuning of the scatterer or the amount of time it
spends in the resonator. First, we introduce the model in its general form,
identifying (i) the traveling mode that optimally retains the full quantum
information of the resonator field and (ii) a suitable figure of merit that we
study analytically in terms of the system parameters. Then, we discuss two
feasible implementations based on ensembles of two-level atoms interacting with
cavity fields. In addition, we discuss how to integrate traditional cavity QED
in our proposal using three-level atoms.",1308.6467v2
2014-03-03,Electromagnetically induced transparency like transmission in a metamaterial composed of cut-wire pairs with indirect coupling,"We theoretically and numerically investigate metamaterials composed of
coupled resonators with indirect coupling. First, we theoretically analyze a
mechanical model of coupled resonators with indirect coupling. The theoretical
analysis shows that an electromagnetically induced transparency (EIT)-like
phenomenon with a transparency bandwidth narrower than the resonance linewidths
of the constitutive resonators can occur in the metamaterial with strong
indirect coupling. We then numerically examine the characteristics of the
metamaterial composed of coupled cut-wire pairs using a finite-difference
time-domain (FDTD) method. The FDTD simulation confirms that an EIT-like
transparency phenomenon occurs in the metamaterial owing to indirect coupling.
Finally, we compare the results of the theoretical and numerical analyses. The
behavior of the EIT-like metamaterial is found to be well described by the
mechanical model of the coupled resonators.",1403.0400v1
2014-03-12,Regge trajectory of the f_0(500) resonance from a dispersive connection to its pole,"We report here our results on how to obtain the Regge trajectory of a
resonance from its pole in a scattering process by imposing analytic
constraints in the complex angular momentum plane. The method, suited for
resonances that dominate an elastic scattering amplitude, has been applied to
the {\rho}(770) and the f_0(500) resonances. Whereas for the former we obtain a
linear Regge trajectory, characteristic of ordinary quark-antiquark states, for
the latter we find a non-linear trajectory with a much smaller slope at the
resonance mass. This provides a strong indication of the non-ordinary nature of
the sigma meson.",1403.2790v1
2014-03-17,Non-ordinary nature of the f_0(500) resonance from its Regge trajectory,"We report our results on how to obtain the Regge trajectory of a resonance
from its pole in a scattering process by imposing analytic constraints in the
complex angular momentum plane. The method, suited for resonances that dominate
an elastic scattering amplitude, has been applied to the {\rho}(770) and the
f_0(500) resonances. Whereas for the former we obtain a linear Regge
trajectory, characteristic of ordinary quark-antiquark states, for the latter
we find a non-linear trajectory with a much smaller slope at the resonance
mass. Moreover, we show that if a linear trajectory with a slope of typical
size is imposed for the f_0(500), the corresponding amplitude is at odds with
the data. This provides a strong indication of the non-ordinary nature of the
sigma meson.",1403.3988v1
2014-03-17,Dynamic strain-mediated coupling of a single diamond spin to a mechanical resonator,"The development of hybrid quantum systems is central to the advancement of
emerging quantum technologies, including quantum information science and
quantum-assisted sensing. The recent demonstration of high quality
single-crystal diamond resonators has led to significant interest in a hybrid
system consisting of nitrogen-vacancy center spins that interact with the
resonant phonon modes of a macroscopic mechanical resonator through crystal
strain. However, the nitrogen-vacancy spin-strain interaction has not been well
characterized. Here, we demonstrate dynamic, strain-mediated coupling of the
mechanical motion of a diamond cantilever to the spin of an embedded
nitrogen-vacancy center. Via quantum control of the spin, we quantitatively
characterize the axial and transverse strain sensitivities of the
nitrogen-vacancy ground state spin. The nitrogen-vacancy center is an atomic
scale sensor and we demonstrate spin-based strain imaging with a strain
sensitivity of 3 10^(-6) strain Hz^(-1/2). Finally, we show how this
spin-resonator system could enable coherent spin-phonon interactions in the
quantum regime.",1403.4173v3
2014-03-20,Chaos in Mean Motion Resonances of the Kuiper Belt,"In this paper on mean motion resonances in the Kuiper belt we consider
effects on resonant bodies captured in an earlier migration by determining
levels of chaos as a function of eccentricity, e, at the most stable orbital
configuration. We find the the maximum observed e's at resonance very closely
correspond to orbits with Lyapunov times ~ 1000 orbital periods of
Neptune--much the same number as applies in the asteroid belt with Neptune's
period replaced by Jupiter's. The fact that this number caps the e's of
markedly chaotic but still existing bodies, implies that the great majority of
escapes at equal and larger e's have already occurred. Yet escapes must
continue at some level if the small population in the outermost belt is to be
maintained because typical lifetimes of bodies there are only ~ 1/10 of the
solar system's age. A study of stability at resonance also reinforces the claim
that the post-migration boundary of the inner Kuiper belt lies near 34 AU and
that the primordial, or pre-migration, outer one near 46 AU.",1403.5138v1
2014-03-21,Decomposition of scattering phase shifts and reaction cross sections using the complex scaling method,"We apply the complex scaling method to the calculation of scattering phase
shifts and extract the contributions of resonances in a phase shift and a cross
section. The decomposition of the phase shift is shown to be useful to
understand the roles of resonant and non-resonant continuum states. As
examples, we apply this method to several two-body systems: (i) a schematic
model with the Gyarmati potential which produces many resonances, (ii) the
alpha-alpha system which has a Coulomb barrier potential in addition to an
attractive nuclear interaction, and (iii) the alpha-n system which has no
barrier potential. Using different kinds of potentials, we discuss the
reliability of this method to investigate the resonance structure in the phase
shifts and cross sections.",1403.5400v1
2014-03-29,Nano-Kelvin thermometry and temperature control: beyond the thermal noise limit,"We demonstrate thermometry with a resolution of 80 $\mathrm{nK} /
\sqrt{\mathrm{Hz}}$ using an isotropic crystalline whispering-gallery mode
resonator based on a dichroic dual-mode technique. We simultaneously excite two
modes that have a mode frequency ratio very close to two ($\pm0.3$ppm). The
wavelength- and temperature-dependence of the refractive index means that the
frequency difference between these modes is an ultra-sensitive proxy of the
resonator temperature. This approach to temperature sensing automatically
suppresses sensitivity to thermal expansion and vibrationally induced changes
of the resonator. We also demonstrate active suppression of temperature
fluctuations in the resonator by controlling the intensity of the driving
laser. The residual temperature fluctuations are shown to be below the limits
set by fundamental thermodynamic fluctuations of the resonator material.",1403.7626v1
2016-11-28,Holographic Kondo and Fano Resonances,"We use holography to study a $(1+1)$-dimensional Conformal Field Theory (CFT)
coupled to an impurity. The CFT is an $SU(N)$ gauge theory at large $N$, with
strong gauge interactions. The impurity is an $SU(N)$ spin. We trigger an
impurity Renormalization Group (RG) flow via a Kondo coupling. The Kondo effect
occurs only below the critical temperature of a large-$N$ mean-field
transition. We show that at all temperatures $T$, impurity spectral functions
exhibit a Fano resonance, which in the low-$T$ phase is a large-$N$
manifestation of the Kondo resonance. We thus provide an example in which the
Kondo resonance survives strong correlations, and uncover a novel mechanism for
generating Fano resonances, via RG flows between $(0 + 1)$-dimensional fixed
points",1611.09368v2
2017-01-01,Analytical Forms for Cross Sections of Di-lepton Production from $e^+e^-$ Collisions around the $J/ψ$ Resonance,"A detailed theoretical derivation of the cross sections of $e^+e^- \to
e^+e^-$ and $e^+e^- \to \mu^+\mu^-$ around the $J/\psi$ resonance is reported.
The resonance and interference parts of the cross sections, related to $J/\psi$
resonance parameters, are calculated. Higher-order corrections for vacuum
polarization and initial-state radiation are considered. An arbitrary upper
limit of radiative correction integration is involved. Full and simplified
versions of analytic formulae are given with precision at the level of 0.1% and
0.2%, respectively. Moreover, the results obtained in the paper can be applied
to the case of the $\psi(3686)$ resonance.",1701.00218v2
2017-01-09,Experimental Investigation of Stub Resonators Built in Plasmonic Slot Waveguides,"In this work, we focus on stub resonators embedded in plasmonic slot
waveguides. The resonators have potential applications in optical interconnects
and sensors. We fabricate the samples by electron beam lithography and
lift-off. We use a scattering matrix based model to quantify the optical power
output from the samples. We measure the properties of the resonators by
coupling light in and out of the slot waveguides by optical antennas, making
use of a cross-polarization based setup utilizing a supercontinuum source and a
high numerical aperture objective lens operating in the telecom-wavelength
range. Our model agrees well with the measured data. Further development on the
stub resonators can be made by using the methods in this paper.",1701.02087v2
2017-01-12,Strong Coupling Cavity QED with Gate-Defined Double Quantum Dots Enabled by a High Impedance Resonator,"The strong coupling limit of cavity quantum electrodynamics (QED) implies the
capability of a matter-like quantum system to coherently transform an
individual excitation into a single photon within a resonant structure. This
not only enables essential processes required for quantum information
processing but also allows for fundamental studies of matter-light interaction.
In this work we demonstrate strong coupling between the charge degree of
freedom in a gate-detuned GaAs double quantum dot (DQD) and a frequency-tunable
high impedance resonator realized using an array of superconducting quantum
interference devices (SQUIDs). In the resonant regime, we resolve the vacuum
Rabi mode splitting of size $2g/2\pi = 238$ MHz at a resonator linewidth
$\kappa/2\pi = 12$ MHz and a DQD charge qubit dephasing rate of $\gamma_2/2\pi
= 80$ MHz extracted independently from microwave spectroscopy in the dispersive
regime. Our measurements indicate a viable path towards using circuit based
cavity QED for quantum information processing in semiconductor nano-structures.",1701.03433v1
2017-01-23,Complete crossing of Fano resonances in an optical microcavity via nonlinear tuning,"We report on the modeling, simulation and experimental demonstration of
complete mode crossings of Fano resonances within chip-integrated
microresonators. The continuous reshaping of resonant lineshapes is achieved
via nonlinear thermo-optical tuning when the cavity-coupled optical pump is
partially absorbed by the material. The locally generated heat then produces a
thermal field, which influences the spatially overlapping optical modes,
allowing thus to alter the relative spectral separation of resonances.
Furthermore, we exploit such tunability to probe continuously the coupling
between different families of quasi-degenerate modes that exhibit asymmetric
Fano-interactions. As a particular case, we demonstrate for the first time a
complete disappearance of one of the modal features in the transmission
spectrum as predicted by U. Fano [Phys. Rev. 124, 1866 (1961)]. The phenomenon
is modeled as a third order non-linearity with a spatial distribution that
depends on the stored optical field and the thermal diffusion within the
resonator. The performed non-linear numerical simulations are in excellent
agreement with the experimental results, which confirm the validity of the
developed theory.",1701.06332v1
2017-01-31,Switchable invisibility of dielectric resonators,"The study of invisibility of an infinite dielectric rod with high refractive
index is based on the two-dimensional Mie scattering problem, and it suggests
strong suppression of scattering due to the Fano interference between
spectrally broad nonresonant waves and narrow Mie-resonant modes. However, when
the dielectric rod has a finite extension, it becomes a resonator supporting
the Fabry-Perot modes which introduce additional scattering and eventually
destroy the invisibility. Here we reveal that for shorter rods with modest
values of the aspect ratio r/L (where r and L are the radius and length of the
rod, respectively), the lowest spectral window of the scattering suppression
recovers completely, so that even a finite-size resonator may become invisible.
We present a direct experimental verification of the concept of switchable
invisibility at microwaves using a cylindrical finite-size resonator with high
refractive index.",1701.09022v1
2017-01-31,Spin anisotropic interactions of lower-polaritons in the vicinity of polaritonic Feshbach resonance,"We determine experimentally the spinor interaction constants of
lower-polaritons $\alpha_1$ and $\alpha_2$ using resonant pump-probe
spectroscopy with a spectrally narrow pump pulse. Our experimental findings are
analyzed with the Bogoliubov-like theory and mean-field two channel model based
on the lower-polariton and biexciton basis. We find an enhancement of the
attractive interaction and dissipative nonlinearity of lower-polaritons with
anti-parallel spins in the vicinity of the biexciton resonance when the energy
of two lower-polaritons approaches energetically that of the biexciton. These
observations are consistent with the existence of a scattering resonance
between lower-polaritons and biexcitons (polaritonic Feshbach resonance).",1701.09113v2
2017-04-06,"Interband transitions in semi-metals, semiconductors, and topological insulators: A new driving force for plasmonics and nanophotonics","Plasmonic and Mie resonances in subwavelength nanostructures provide an
efficient way to manipulate light below the diffraction limit that has fostered
the growth of plasmonics and nanophotonics. Plasmonic resonances have been
mainly related with the excitation of free charge carriers, initially in
metals, and Mie resonances have been identified in Si nanostructures.
Remarkably, although much less studied, semi-metals, semiconductors and
topological insulators of the p-block enable plasmonic resonances without free
charge carriers and Mie resonances with enhanced properties compared with Si.
In this review, we explain how interband transitions in these materials show a
major role in this duality. We evaluate the plasmonic and Mie performance of
nanostructures made of relevant p-block elements and compounds, especially Bi,
and discuss their promising potential for applications ranging from switchable
plasmonics and nanophotonics to energy conversion, especially photocatalysis.",1704.02039v1
2017-04-14,Approaching ultra-strong coupling in Transmon circuit-QED using a high-impedance resonator,"In this experiment, we couple a superconducting Transmon qubit to a
high-impedance $645\ \Omega$ microwave resonator. Doing so leads to a large
qubit-resonator coupling rate $g$, measured through a large vacuum Rabi
splitting of $2g\simeq 910$ MHz. The coupling is a significant fraction of the
qubit and resonator oscillation frequencies $\omega$, placing our system close
to the ultra-strong coupling regime ($\bar{g}=g/\omega=0.071$ on resonance).
Combining this setup with a vacuum-gap Transmon architecture shows the
potential of reaching deep into the ultra-strong coupling $\bar{g} \sim 0.45$
with Transmon qubits.",1704.04421v1
2017-04-17,Unconventional next nearest neighbor resonance coupling and states flipping mechanism in degenerate optical microcavities,"We report a specially configured non-Hermitian optical microcavity, imposing
spatially imbalanced gain-loss profile, to host an exclusively proposed next
nearest neighbor resonances coupling scheme. Adopting scattering matrix
(S-matrix) formalism, the effect of interplay between such proposed resonance
interactions and the incorporated non-Hermiticity in the microcavity is
analyzed drawing a special attention to the existence of hidden singularities,
namely exceptional points (EPs); where at least two coupled resonances
coalesce. We establish adiabatic flip-of-states phenomena of the coupled
resonances in the complex frequency plane (k-plane) which is essentially an
outcome of the fact that the respective EP is being encircled in system
parameter plane. Encountering such multiple EPs, the robustness of
flip-of-states phenomena have been analyzed via continuous tuning of coupling
parameters along a special hidden singular line which connects all the EPs in
the cavity. Such a numerically devised cavity, incorporating the exclusive next
neighbor coupling scheme, have been designed for the first time to study the
unconventional optical phenomena in the vicinity of EPs.",1704.04951v1
2018-05-03,Controlling steady-state second harmonic signal via linear and nonlinear Fano resonances,"Nonlinear signal even from a single molecule becomes visible at hot spots of
plasmonic nanoparticles. In these structures, Fano resonances can control the
nonlinear response in two ways. \textit{(i)} A linear Fano resonance can
enhance the hot spot field, resulting enhanced nonlinear signal. \textit{(ii)}
A nonlinear Fano resonance can enhance the nonlinear signal without enhancing
the hot spot. In this study, we compare the enhancement of second harmonic
signal at the steady-state obtained via these two methods. Since we are
interested in the steady-state signal, we adapt a linear enhancement which
works at the steady-state. This is different than the dark-hot resonances that
appears in the transparency window due to enhanced plasmon lifetime.",1805.01148v1
2018-05-09,Study on the resonant parameters of $Y(4220)$ and $Y(4390)$,"Many vector charmonium-like states have been reported recently in the cross
sections of $e^+e^- \rightarrow \omega\chi_{c0}$, $\pi^{+}\pi^{-}h_c$,
$\pi^{+}\pi^{-}J/\psi$, $\pi^{+}\pi^{-}\psi(3686)$ and
$\pi^{+}D^{0}D^{*-}+c.c.$ To better understand the nature of these states, a
combined fit is performed to these cross sections by using three resonances
$Y(4220)$, $Y(4390)$ and $Y(4660)$. The resonant parameters for the three
resonances are obtained. We emphasize that two resonances $Y(4220)$ and
$Y(4390)$ are sufficient to explain these cross sections below 4.6 GeV. The
lower limits of $Y(4220)$ and $Y(4390)$'s leptonic decay widths are also
determined to be $(36.4\pm2.0\pm4.2)$ and $(123.8\pm6.5\pm9.0)$ eV.",1805.03565v3
2018-05-10,Tuning of temperature dependence of resonance frequency shift of atomically thin mechanical resonators with van der Waals heterojunction,"Atomically thin 2-dimensional (2D) mechanical resonators are expected to be
highly sensitive force sensor and high performance nano-electro-mechanical
systems because of their excellent electrical and mechanical properties. For
practical application, the stability of their resonance frequencies against the
temperature is very crucial. Here, we demonstrate the manipulation of thermal
expansion coefficients (TECs) by making van der Waals heterojunction, graphene
and MoS2, which have opposite signs of TECs. The apparent TEC of the 2D
heterojunction is greatly suppressed to 1/3 of monolayer graphene without the
limitation of tunability of the resonance frequency by application of
electrostatic attraction.",1805.03835v1
2018-05-13,Resonant $pp\to W^+ Zjj$ events at the LHC from a unitarized study of the EChL,"We present a study of the production of vector resonances at the LHC via
$W^+Z$ vector boson scattering and explore the sensitivities to these
resonances for expected LHC luminosities. We work in the framework of the
electroweak chiral Lagrangian, where these resonances can be generated
dynamically by unitarizing the scattering amplitudes. We implement all these
features into a model adapted for MonteCarlo, the IAM-MC, that allows us to
give predictions for the sensitivity to these resonances and to the relevant
parameters involved for $pp \to W^+Zjj$, $pp\to \ell_1^+\ell_1^-\ell_2^+\nu
jj$, and $pp \to JJjj$.",1805.04870v1
2018-05-15,Probing Anomalous Inelastic Scattering in Spin-ice Ho$_2$Ti$_2$O$_7$ through Resonant Raman Spectroscopy,"We report on a study of the inelastic scattering properties of (001) and
(111) Ho$_2$Ti$_2$O$_7$ single crystals at room temperature. Structural and
compositional analysis along with absorption measurement confirms single
crystalline phase of all samples. Room temperature polarized Raman measurements
were performed on crystals in non-resonant and two different resonant
conditions by using six different laser excitation lines. Lorentzian model
fitting analysis is performed on all measured spectra in order to identify the
difference in the Raman scattering cross-section in resonant and non-resonant
conditions. Variations in the fitting parameters on account of different
polarization configurations and crystallographic orientations has helped
identifying their symmetry if present. Several possible scattering pathways are
discussed in order to qualitatively explain the anomalous scattering results in
Ho$_2$Ti$_2$O$_7$",1805.05505v1
2018-05-15,Microwave dual-mode resonators for coherent spin-photon coupling,"We implement superconducting YBCO planar resonators with two fundamental
modes for circuit quantum electrodynamics experiments. We first demonstrate
good tunability in the resonant microwave frequencies and in their interplay as
it emerges from the dependence of the transmission spectra on the device
geometry. We then investigate the magnetic coupling of the resonant modes with
bulk samples of DPPH organic radical spins. The transmission spectroscopies
performed at low temperature show that the coherent spin-photon coupling regime
with the spin ensembles can be achieved by each of the resonator modes. The
analysis of the results within the framework of the Input-Output formalism and
by means of entropic measures demonstrates coherent mixing of the degrees of
freedom corresponding to two remote spin ensembles and, with a suitable choice
of the geometry, the approaching of a regime with spin-induced mixing of the
two photon modes.",1805.05843v3
2018-05-15,AC Stark Shifts of Dark Resonances Probed with Ramsey Spectroscopy,"The off-resonant AC Stark shift for coherent population trapping (CPT)
resonances probed with Ramsey spectroscopy is investigated experimentally and
theoretically. Measurements with laser-cooled $^{87}$Rb atoms show excellent
quantitative agreement with a simple theory. The shift depends on the relative
intensity of the two CPT light fields, but depends only weakly on the total
intensity. Since the origin of the shift is through couplings of the
interrogation light to off-resonant excited state hyperfine levels, the size
and sign of the shift depend on the specific interrogation scheme. However, the
simple theory shows that for several commonly used interrogation schemes the
off-resonant shift goes to zero at specific values of this relative intensity.",1805.06029v2
2008-07-09,Formation and decay of hadronic resonances in the QGP,"Hadronic resonances can play a pivotal role in providing experimental
evidence for partial chiral symmetry restoration in the deconfined quark-gluon
phase produced at RHIC. Their lifetimes, which are comparable to the lifetime
of the partonic plasma phase, make them an invaluable tool to study medium
modifications to the resonant state due to the chiral transition. In this paper
we show that the heavier, but still abundant, light and strange quark
resonances K*, phi, Delta and Lambda* have large probability to be produced
well within the plasma phase due to their short formation times. We demonstrate
that, under particular kinematic conditions, these resonances can be formed and
will decay inside the partonic state, but still carry sufficient momentum to
not interact strongly with the hadronic medium after the QCD phase transition.
Thus, K*, phi, Delta and Lambda* should exhibit the characteristic property
modifications which can be attributed to chiral symmetry restoration, such as
mass shifts, width broadening or branching ratio modifications.",0807.1509v2
2008-07-17,"Planetary Migration in Resonance, the question of the Eccentricities : Les Houches contribution","The formation of resonant planets pairs in exoplanetary systems involves
planetary migration inside the protoplanetary disc : an inwards migrating outer
planet captures in Mean Motion Resonance an inner planet. During the migration
of the resonant pair of planets, the eccentricities are expected to rise
excessively, if no damping mechanism is applied on the inner planet. We express
the required damping action to match the observations, and we show that the
inner disk can play this role. This result applies for instance to the system
GJ 876 : we reproduce the observed orbital elements through a fully
hydrodynamical simulation of the evolution of the resonant planets.",0807.2828v2
2009-12-06,Electron tunneling through hybrid superconducting-normal quantum point contacts under microwave radiation,"We present a theoretical analysis for photon-assisted electron tunneling
through a hybrid superconducting-normal quantum point contact (QPC) consisting
of a superconducting lead (S), a normal two-level quantum dot (N), and a normal
lead (N). Using single particle non-equilibrium Green's function formalism, we
incorporate Floquet basis in the Nambu space and solve the Green's function
with finite matrix truncation to obtain the transport properties numerically.
Based on the proposed method, we studied the effects of photon-induced
single-level oscillations and quantum transition between two levels on the
current-voltage (I-V) characteristics of a superconducting QPC. For the single
level case, the main dc resonance in the I-V curve remains unchanged regardless
of the frequency and amplitude of the radiation, and a series of secondary
resonances due to multi-photon processes are present. When the transition
between two levels ($\epsilon_{1}$, $\epsilon_{2}$) is taken into account and
level oscillations are neglected, photons only have significant effects at Rabi
resonance when $\hbar\omega=(\epsilon_{2}-\epsilon_{1})$. At Rabi resonance,
the main dc resonance splits into two, and the separation between them is
determined by the coupling strength of the two levels.",0912.1087v2
2009-12-07,Dissipation due to tunneling two-level systems in gold nanomechanical resonators,"We present measurements of the dissipation and frequency shift in
nanomechanical gold resonators at temperatures down to 10 mK. The resonators
were fabricated as doubly-clamped beams above a GaAs substrate and actuated
magnetomotively. Measurements on beams with frequencies 7.95 MHz and 3.87 MHz
revealed that from 30 mK to 500 mK the dissipation increases with temperature
as $T^{0.5}$, with saturation occurring at higher temperatures. The relative
frequency shift of the resonators increases logarithmically with temperature up
to at least 400 mK. Similarities with the behavior of bulk amorphous solids
suggest that the dissipation in our resonators is dominated by two-level
systems.",0912.1281v1
2009-12-14,Regge-plus-resonance predictions for charged-kaon photoproduction from the deuteron,"We present a Regge-inspired effective-Lagrangian framework for charged-kaon
photoproduction from the deuteron. Quasi-free kaon production is investigated
using the Regge-plus-resonance elementary operator within the non-relativistic
plane-wave impulse approximation. The Regge-plus-resonance model was developed
to describe photoinduced and electroinduced kaon production off protons and can
be extended to strangeness production off neutrons. The non-resonant
contributions to the amplitude are modelled in terms of K+(494) and K*+(892)
Regge-trajectory exchange in the t-channel. This amplitude is supplemented with
a selection of s-channel resonance-exchange diagrams. We investigate several
sources of theoretical uncertainties on the semi-inclusive charged-kaon
production cross section. The experimental error bars on the photocoupling
helicity amplitudes turn out to put severe limits on the predictive power when
considering quasi-free kaon production on a bound neutron.",0912.2679v1
2009-12-17,Magnetic non-collinear neutron wave resonator,"Equations for the neutron reflection amplitude from a magnetic non-collinear
wave resonator (NWR) are obtained. It is shown that resonances of the same
reflection order of neutrons experiencing spin-flip (spin-flip neutrons) appear
in pairs. Conditions under which in the resonator square enhancement of the
spin-flip neutron reflection intensity with respect to growth of the portion of
scattered and absorbed neutrons takes place, are determined.",0912.3557v2
2009-12-20,Resonances on deformed thick branes,"In this work we investigate the issue of gravity and fermion localization and
resonances in $(4,1)$-branes constructed with one scalar field coupled with
gravity in deformed models. Such models give solutions for the scalar field
that is the usual kink solution in the extra dimension for a parameter $p=1$
and deformations with a two-kink profile for odd $p>1$. Gravity is localized
and resonant modes are found for small values of $p$. The coupling between the
scalar field and spinors is a necessary condition for fermions to be localized
on such branes. After performing a chiral decomposition of the five-dimensional
spinor we found resonances with both chiralities for all odd $p$'s. The
correspondence between the spectra for left and right chirality is guaranteed
and Dirac fermions are realized on the brane. The increasing of $p$
characterizes the formation of branes with internal structure that turns the
gravitational interaction more effective for fermions aside the brane,
increasing their lifetime. The influence of the internal structure of the
branes and the presence of resonances for gravity and fermionic modes is
addressed.",0912.4021v1
2011-11-25,Ultra-high field enhancing in Split Ring Resonators by azimuthally polarized excitation,"We study the field enhancement and resonance frequencies in split-ring
resonators (SRR) illuminated by azimuthally polarized light. We find that
compared to linearly polarized illumination, the azimuthally polarized
illumination increase the intensity enhancement by more than an order of
magnitude. We attribute the increase in the intensity enhancement to the
improved overlap between the SRR geometry and the direction of the electric
field vector in each point. In addition, we present and explore a method to
tune the resonance frequency of the SRR (for azimuthal polarization) by
introducing more gaps to the structure. This approach allows for simple and
straightforward tuning of the resonance frequency with small impact on the
intensity enhancement. The impact of the design parameters on the intensity
enhancement under azimuthally polarized illumination is also studied in
details, exhibiting clear differences to the case of linear polarized
illumination.",1111.6080v1
2012-01-04,Angular dependent resonant photoemission processes at the 2p thresholds in nickel metal,"Angle-resolved valence-band resonant photoemission of nickel metal has been
measured close to the 2p core-level thresholds with synchrotron radiation. The
well-known 6-eV correlation satellite has an intensity enhancement of about two
orders of magnitude at resonance. The angular dependence of the photoemission
intensity has been studied as function of photon energy and provides
unambiguous evidence for interference effects all the way up to the resonance
maximum. The observation of different angular asymmetries, {\beta}, for the
valence band and the satellite is discussed in connection to the origin of the
resonant photoemission process and the character of the satellite.",1201.0932v1
2012-01-05,"Resonant inelastic soft-x-ray scattering spectra at the N1s and C1s edges of poly(pyridine-2,5-diyl)","Resonant inelastic scattering measurements of poly(pyridine-2,5-diyl) have
been performed at the N1s and C1s edges using synchrotron radiation. For
comparison, molecular orbital calculations of the spectra have been carried out
with the repeat unit as a model molecule of the polymer chain. The resonant
emission spectra show depletion of the p electron bands which is consistent
with symmetry selection and momentum conservation rules. The depletion is most
obvious in the resonant inelastic scattering spectra of carbon while the
nitrogen spectra are dominated by lone pair n orbital emission of s symmetry
and are less excitation energy dependent. By comparing the measurements to
calculations an isomeric dependence of the resonant spectra is found giving
preference to two of the four possible isomers in the polymer.",1201.1181v1
2012-01-09,Resonant charge transfer at dielectric surfaces,"We report on the theoretical description of secondary electron emission due
to resonant charge transfer occurring during the collision of metastable
nitrogen molecules with dielectric surfaces. The emission is described as a two
step process consisting of electron capture to form an intermediate shape
resonance and subsequent electron emission by decay of this ion, either due to
its natural life time or its interaction with the surface. The electron capture
is modeled using the Keldysh Green's function technique and the negative ion
decay is described by a combination of the Keldysh technique and a rate
equation approach. We find the resonant capture of electrons to be very
efficient and the natural decay to be clearly dominating over the
surface-induced decay. Secondary electron emission coefficients are calculated
for aluminum oxide, magnesium oxide, silicon oxide, and diamond at several
kinetic energies of the projectile. With the exception of magnesium oxide the
coefficients turn out to be of the order of 0.1 over the whole range of kinetic
energies. This rather large value is a direct consequence of the shape
resonance acting as a relay state for electron emission.",1201.1724v1
2012-01-16,Optical properties of Fano-resonant metallic metasurfaces on a substrate,"Three different periodic optical metasurfaces exhibiting Fano resonances are
studied in mid-IR frequency range in the presence of a substrate. We develop a
rigorous semi-analytical technique and calculate how the presence of a
substrate affects optical properties of these structures. An analytical minimal
model based on the truncated exact technique is introduced and is shown to
provide a simple description of the observed behavior. We demonstrate that the
presence of a substrate substantially alters the collective response of the
structures suppressing Wood's anomalies and spatial dispersion of the
resonances. Different types of Fano resonances are found to be affected
differently by the optical contrast between the substrate and the superstrate.
The dependence of the spectral position of the resonances on the
substrate/superstrate permittivities is studied and the validity of the widely
used effective medium approaches is re-examined.",1201.3146v1
2012-01-30,Quantum transducer in circuit optomechanics,"Mechanical resonators are macroscopic quantum objects with great potential.
They couple to many different quantum systems such as spins, optical photons,
cold atoms, and Bose Einstein condensates. It is however difficult to measure
and manipulate the phonon state due to the tiny motion in the quantum regime.
On the other hand, microwave resonators are powerful quantum devices since
arbitrary photon state can be synthesized and measured with a quantum
tomography. We show that a linear coupling, strong and controlled with a gate
voltage, between the mechanical and the microwave resonators enables to create
quantum phonon states, manipulate hybrid entanglement between phonons and
photons and generate entanglement between two mechanical oscillators. In
circuit quantum optomechanics, the mechanical resonator acts as a quantum
transducer between an auxiliary quantum system and the microwave resonator,
which is used as a quantum bus.",1201.6293v1
2012-01-31,Résonances près de seuils d'opérateurs magnétiques de Pauli et de Dirac,"We consider the perturbations $H := H_{0} + V$ and $D := D_{0} + V$ of the
free 3D Hamiltonians $H_{0}$ of Pauli and $D_{0}$ of Dirac with non-constant
magnetic field, and $V$ is a electric potential which decays
super-exponentially with respect to the variable along the magnetic field. We
show that in appropriate Banach spaces, the resolvents of $H$ and $D$ defined
on the upper half-plane admit meromorphic extensions. We define the resonances
of $H$ and $D$ as the poles of these meromorphic extensions. We study the
distribution of resonances of $H$ close to the origin 0 and that of $D$ close
to $\pm m$, where $m$ is the mass of a particle. In both cases, we first obtain
an upper bound of the number of resonances in small domains in a vicinity of 0
and $\pm m$. Moreover, under additional assumptions, we establish asymptotic
expansions of the number of resonances which imply their accumulation near the
thresholds 0 and $\pm m$. In particular, for a perturbation $V$ of definite
sign, we obtain information on the distribution of eigenvalues of $H$ and $D$
near 0 and $\pm m$ respectively.",1201.6552v2
2012-04-20,Baryon resonances as dynamically generated states in chiral dynamics,"We discuss baryon resonances which are dynamically generated in hadron
dynamics based on chiral coupled channels approach. With the dynamical
description of the baryon resonance, we discuss the origin of the resonance
pole, finding that for the description of N(1535) some other components than
meson and baryon are necessary. Since the chiral unitary model provides a
microscopic description in terms of constituent hadrons, it is straightforward
to calculate transition amplitudes and form factors of resonances without
introducing further parameters. Finally we briefly discuss few-body nuclear
kaonic systems as hadronic molecular states.",1204.4534v1
2012-04-24,Parametric four-wave mixing toolbox for superconducting resonators,"We study a superconducting circuit that can act as a toolbox to generate
various Bogoliubov-linear and nonlinear quantum operations on the microwave
photon modes of superconducting resonators within one single circuit. The
quantum operations are generated by exploring dispersive four-wave mixing (FWM)
processes involving the resonator modes. Different FWM geometries can be
realized by adjusting the circuit parameters and by applying appropriate
microwave drivings. We illustrate this scheme using a circuit made of two
superconducting qubits that couple with each other. Each qubit couples with one
superconducting resonator. We also discuss main quantum errors in this scheme
and study the fidelity of the quantum operations by numerical simulation. Our
scheme provides a practical approach to realize quantum information protocols
on superconducting resonators.",1204.5450v2
2013-09-12,Hadronic resonances in heavy-ion collisions at ALICE (Strangeness in Quark Matter 2013),"Properties of the hadronic phase of high-energy heavy-ion collisions can be
studied by measuring the ratios of hadronic resonance yields to the yields of
longer-lived particles. These ratios can be used to study the strength of
re-scattering effects, the chemical freeze-out temperature, and the lifetime
between chemical and kinetic freeze-out. The restoration of chiral symmetry
during the early hadronic phase or near the phase transition may lead to shifts
in the masses and increases in the widths of hadronic resonances. The ALICE
collaboration has measured the spectra, masses, and widths of the K*(892)0 and
phi(1020) resonances in Pb-Pb collisions at 2.76 TeV. These results, including
RAA and the ratios of the integrated resonance yields to stable hadron yields,
are presented and compared to results from other collision systems and to
theoretical predictions.",1309.3322v1
2013-09-18,Spin polarization oscillations without spin precession: spin-orbit entangled resonances in quasi-one-dimensional spin transport,"Resonant behavior involving spin-orbit entangled states occurs for spin
transport along a narrow channel defined in a two-dimensional electron gas,
including an apparent rapid relaxation of the spin polarization for special
values of the channel width and applied magnetic field (so-called ballistic
spin resonance). A fully quantum mechanical theory for transport through
multiple subbands of the one-dimensional system provides the dependence of the
spin transport on the applied magnetic field and channel width, including a
resonant depolarization of spins when the Zeeman energy matches the subband
energy splittings and a spin texture transverse to the magnetic field. The
resonance phenomenon is robust to disorder.",1309.4509v1
2013-09-25,Kink-Antikink Scattering in φ^4 and φ^6 Models,"For kink-antikink scattering within the \phi^4 non--linear field theory in
one space and one time dimension resonance type configurations emerge when the
relative velocity between kink and antikink falls below a critical value. It
has been conjectured that the vibrational excitation of the kink would be the
source for these resonances because (simplified) collective coordinate
calculations, that emphasized on this excitation, qualitatively reproduced
those resonances. Surprisingly a numerical study in the \phi^6 field theory
also exhibited such resonances even though it does not contain the vibrational
excitation. To explore this contradiction we start from the working hypothesis
that in either model any collective coordinate ansatz which includes a degree
of freedom similar to the vibrational excitation leads to resonances,
regardless of whether or not this mode emerges as a solution to the
(linearized) field equations. To this end we compare numerical results in the
\phi^4 and \phi^6 models that arise from the full set of partial differential
equations to those from the ordinary differential equations for a collective
coordinate ansatz. An inaccuracy in literature formulas for the collective
coordinate approach in the \phi^4 model requires to revisit those calculations.",1309.6607v2
2014-05-01,Resonant Scattering of Surface Plasmon Polaritons by Dressed Quantum Dots,"The resonant scattering of surface plasmon-polariton waves by embedded
semiconductor quantum dots above the dielectric/metal interface is explored in
the strong-coupling regime. In contrast to non-resonant scattering by a
localized dielectric surface defect, a strong resonant peak in the scattering
field spectrum is predicted and accompanied by two side valleys. The peak
height depends nonlinearly on the amplitude of surface plasmon-polariton waves,
reflecting the feedback dynamics from a photon-dressed electron-hole plasma
inside the quantum dots. This unique behavior in the scattering field peak
strength is correlated with the occurrence of a resonant dip in the absorption
spectrum of surface plasmon-polariton waves due to interband photon-dressing
effect. Our result on the scattering of surface plasmon-polariton waves may be
experimentally observable and applied to spatially selective illumination and
imaging of individual molecules.",1405.0215v1
2014-05-02,Rotation-induced Mode Coupling in Open Wavelength-scale Microcavities,"We study the interplay between rotation and openness for mode coupling in
wavelength-scale microcavities. In cavities deformed from a circular disk, the
decay rates of a quasi-degenerate pair of resonances may cross or anti-cross
with increasing rotation speed. The standing-wave resonances evolve to
traveling-wave resonances at high rotation speed, however, both the clockwise
(CW) and counter-clockwise (CCW) traveling-wave resonances can have a lower
cavity decay rate, in contrary to the intuitive expectation from
rotation-dependent effective index. With increasing rotation speed, a phase
locking between the CW and CCW wave components in a resonance takes place.
These phenomena result from the rotation-induced mode coupling, which is
strongly influenced by the openness of the microcavity. The possibility of a
non-monotonic Sagnac effect is also discussed.",1405.0468v1
2014-05-05,Resonant metallic states in driven quasiperiodic lattices,"We consider a quasiperiodic Aubry-Andre (AA) model and add a weak
time-periodic and spatially quasiperiodic perturbation. The undriven AA model
is chosen to be well in the insulating regime. The spatial quasiperiodic
perturbation extends the model into two dimensions in reciprocal space. For a
spatial resonance which reduces the reciprocal space dynamics to an effective
one-dimensional two-leg ladder case, the ac perturbation resonantly couples
certain groups of localized eigenstates of the undriven AA model and turns them
into extended metallic ones. Slight detuning of the spatial and temporal
frequencies off resonance returns these states into localized ones. We analyze
the details of the resonant metallic eigenstates using Floquet representations.
In particular, we find that their size grows linearly with the system size.
Initial wave packets overlap with resonant metallic eigenstates and lead to
ballistic spreading.",1405.0765v1
2014-05-05,Cavity polariton optomechanics: Polariton path to fully resonant dispersive coupling in optomechanical resonators,"Resonant photoelastic coupling in semiconductor nanostructures opens new
perspectives for strongly enhanced light-sound interaction in optomechanical
resonators. One potential problem, however, is the reduction of the cavity
Q-factor induced by dissipation when the resonance is approached. We show in
this letter that cavity-polariton mediation in the light-matter process
overcomes this limitation allowing for a strongly enhanced photon-phonon
coupling without significant lifetime reduction in the strongly-coupled regime.
Huge optomechanical coupling factors in the PetaHz/nm range are envisaged,
three orders of magnitude larger than the backaction produced by the mechanical
displacement of the cavity mirrors.",1405.0886v1
2014-05-05,Novel architecture for ultra-stable micro-ring resonator based optical frequency combs,"We report a novel geometry for OPOs based on nonlinear microcavity
resonators. This approach relies on a self-locked scheme that enables OPO
emission without the need for thermal locking of the pump laser to the
microcavity resonance. By exploiting a CMOS-compatible microring resonator, we
achieve oscillation with a complete absence of shutting down, or
self-terminating behavior, a very common occurrence in externally pumped OPOs.
Further, this scheme consistently produces very wide bandwidth (>300nm, limited
by our experimental set-up) combs that oscillate at a spacing of the FSR of the
micro cavity resonance.",1405.1103v2
2014-05-06,Giant second harmonic generation by engineering of double plasmonic resonances at nanoscale,"We have investigated second harmonic generation (SHG) from Ag-coated LiNbO3
(LN) core-shell nanocuboids and found that giant SHG can occur via deliberately
designed double plasmonic resonances. By controlling the aspect ratio, we can
tune fundamental wave (FW) and SHG signal to match the longitudinal and
transverse plasmonic modes simultaneously, and achieve giant enhancement of SHG
by more than five orders of magnitude in comparison to a bare LN nanocuboid and
by about one order of magnitude to the case adopting only single plasmonic
resonance. The underlying key physics is that the double-resonance nanoparticle
enables greatly enhanced trapping and harvesting of incident FW energy,
efficient internal transfer of optical energy from FW to SHW, and much improved
power to transport the SHG energy from the nanoparticle to the far-field
region. The proposed double-resonance nanostructure can serve as an efficient
subwavelength coherent light source through SHG and enable flexible engineering
of light-matter interaction at nanoscale.",1405.1381v1
2014-05-14,Intermittency in an Optomechanical Cavity Near a Subcritical Hopf Bifurcation,"We experimentally study an optomechanical cavity consisting of an oscillating
mechanical resonator embedded in a superconducting microwave transmission line
cavity. Tunable optomechanical coupling between the mechanical resonator and
the microwave cavity is introduced by positioning a niobium-coated single mode
optical fiber above the mechanical resonator. The capacitance between the
mechanical resonator and the coated fiber gives rise to optomechanical
coupling, which can be controlled by varying the fiber-resonator distance. We
study radiation pressure induced self-excited oscillations as a function of
microwave driving parameters (frequency and power). Intermittency between limit
cycle and steady state behaviors is observed with blue-detuned driving
frequency. The experimental results are accounted for by a model that takes
into account the Duffing-like nonlinearity of the microwave cavity. A stability
analysis reveals a subcritical Hopf bifurcation near the region where
intermittency is observed.",1405.3467v2
2014-05-20,A silicon single-crystal cryogenic optical resonator,"We report on the demonstration and characterization of a silicon optical
resonator for laser frequency stabilization, operating in the deep cryogenic
regime at temperatures as low as 1.5 K. Robust operation was achieved, with
absolute frequency drift less than 20 Hz over 1 hour. This stability allowed
sensitive measurements of the resonator thermal expansion coefficient
($\alpha$). We found $\alpha=4.6\times10^{-13}$ ${\rm K^{-1}}$ at 1.6 K. At
16.8 K $\alpha$ vanishes, with a derivative equal to $-6\times10^{-10}$ ${\rm
K}^{-2}$. The temperature of the resonator was stabilized to a level below 10
$\mu$K for averaging times longer than 20 s. The sensitivity of the resonator
frequency to a variation of the laser power was also studied. The corresponding
sensitivities and the expected Brownian noise indicate that this system should
enable frequency stabilization of lasers at the low-$10^{-17}$ level.",1405.5037v1
2014-05-22,Electromagnetically induced transparency and tunable fano resonances in hybrid optomechanics,"We explain the phenomena of electromagnetically induced transparency (EIT) of
a weak probe field and tunable Fano resonances in hybrid optomechanics. The
system of study consists of a two-level atom coupled to a single-mode field of
an optomechanical resonator with a moving mirror. We show that a single EIT
window exists in the presence of optomechanical coupling or Jaynes-Cummings
coupling, whereas two distinct double EIT windows occur when both the couplings
are simultaneously present. Furthermore, based on our analytic and numerical
work, we prove the existence of tunable fano resonances in the system. The
controlling parameters of the system, which switch from a single EIT window to
double EIT windows and are needed to tune the fano resonances, can be realized
in present-day laboratory experiments.",1405.5614v4
2014-05-22,Time-domain response of atomically thin $\mathrm{MoS_2}$ nanomechanical resonators,"We measure the energy relaxation rate of single- and few-layer molybdenum
disulphide ($\mathrm{MoS_2}$) nanomechanical resonators by detecting the
resonator ring-down. Recent experiments on these devices show a remarkably low
quality (Q)-factor when taking spectrum measurements at room temperature. The
origin of the low spectral Q-factor is an open question, and it has been
proposed that besides dissipative processes, frequency fluctuations contribute
significantly to the resonance line-width. The spectral measurements performed
thus far however, do not allow one to distinguish these two processes. Here, we
use time-domain measurements to quantify the dissipation. We compare the
Q-factor obtained from the ring-down measurements to those obtained from the
thermal noise spectrum and from the frequency response of the driven device. In
few-layer and single-layer $\mathrm{MoS_2}$ resonators the two are in close
agreement, which demonstrates that the spectral line-width in $\mathrm{MoS_2}$
membranes at room temperature is limited by dissipation, and that excess
spectral broadening plays a negligible role.",1405.5666v2
2014-05-31,Contribution of $Z_b$ resonances to $Υ(5S) \to πππ χ_b$,"We discuss the recently presented Belle results on the decays $\Upsilon(5S)
\to \pi \pi \pi \chi_{bJ}(1P)$. The data indicate that in addition to the
$\omega$ emission, $\Upsilon(5S) \to \omega \chi_{bJ}$, there is a significant
non resonant background in the three pion spectrum. We suggest that a sizable
fraction of this background may be associated with the cascade process
$\Upsilon(5S) \to \pi Z_b \to \pi \rho \chi_b$ involving the $Z_b(10610)$ and
$Z_b(10650)$ resonances. If confirmed by the data, this would be the first
observation of transition from the $Z_b$ resonances to lower bottomonium with
emission of a light meson state different from a single pion, which may provide
a new input in understanding of the internal dynamics of these resonances.",1406.0082v1
2014-06-03,Tidal dissipation and the formation of Kepler near-resonant planets,"Multi-planetary systems detected by the Kepler mission present an excess of
planets close to first-order mean-motion resonances (2:1 and 3:2) but with a
period ratio slightly higher than the resonant value. Several mechanisms have
been proposed to explain this observation. Here we provide some clues that
these near-resonant systems were initially in resonance and reached their
current configuration through tidal dissipation. The argument that has been
opposed to this scenario is that it only applies to the close-in systems and
not to the farthest ones for which the tidal effect is too weak. Using the
catalog of KOI of the Kepler mission, we show that the distributions of period
ratio among the most close-in planetary systems and the farthest ones differ
significantly. This distance dependent repartition is a strong argument in
favor of the tidal dissipation scenario.",1406.0694v2
2014-06-05,Frequencies and resonances around $L_4$ in the elliptic restricted three-body problem,"The stability of the Lagrangian point $L_4$ is investigated in the elliptic
restricted three-body problem by using Floquet's theory. Stable and unstable
domains are determined in the parameter plane of the mass parameter and the
eccentricity by computing the characteristic exponents. Frequencies of motion
around $L_4$ have been determined both in the stable and unstable domains and
fitting functions for the frequencies are derived depending on the mass
parameter and the eccentricity. Resonances between the frequencies are studied
in the whole parameter plane. It is shown that the 1:1 resonances are not
restricted only to single curves but extend to the whole unstable domain. In
the unstable domains longer escape times of the test particle from the
neighbourhood of $L_4$ are related to certain resonances, but changing the
parameters the same resonances may lead to faster escape.",1406.1331v1
2014-06-09,Graphene nanoelectromechanical resonators for detection of modulated terahertz radiation,"We propose and analyze the detector of modulated terahertz (THz) radiation
based on the graphene field-effect transistor with mechanically floating gate
made of graphene as well. The THz component of incoming radiation induces
resonant excitation of plasma oscillations in graphene layers (GLs). The
rectified component of the ponderomotive force between GLs invokes resonant
mechanical swinging of top GL, resulting in the drain current oscillations. To
estimate the device responsivity, we solve the hydrodynamic equations for the
electrons and holes in graphene governing the plasma-wave response, and the
equation describing the graphene membrane oscillations. The combined
plasma-mechanical resonance raises the current amplitude by up to four orders
of magnitude. The use of graphene as a material for the elastic gate and
conductive channel allows the voltage tuning of both resonant frequencies in a
wide range.",1406.2127v1
2014-06-10,Micro--structured crystalline resonators for optical frequency comb generation,"Optical frequency combs have recently been demonstrated in micro--resonators
through nonlinear Kerr processes. Investigations in the past few years provided
better understanding of micro--combs and showed that spectral span and mode
locking are governed by cavity spectrum and dispersion. While various cavities
provide unique advantages, dispersion engineering has been reported only for
planar waveguides. In this Letter, we report a resonator design that combines
dispersion control, mode crossing free spectrum, and ultra--high quality
factor. We experimentally show that as the dispersion of a MgF2 resonator is
flattened, the comb span increases reaching 700 nm with as low as 60 mW pump
power at 1560 nm wavelength, corresponding to nearly 2000 lines separated by 46
GHz. The new resonator design may enable efficient low repetition rate coherent
octave spanning frequency combs without the need for external broadening, ideal
for applications in optical frequency synthesis, metrology, spectroscopy, and
communications.",1406.2682v1
2014-06-13,Resonant atom-dimer collisions in cesium: Testing universality at positive scattering lengths,"We study the collisional properties of an ultracold mixture of cesium atoms
and dimers close to a Feshbach resonance near 550G in the regime of positive
$s$-wave scattering lengths. We observe an atom-dimer loss resonance that is
related to Efimov's scenario of trimer states. The resonance is found at a
value of the scattering length that is different from a previous observation at
low magnetic fields. This indicates non-universal behavior of the Efimov
spectrum for positive scattering lengths. We compare our observations with
predictions from effective field theory and with a recent model based on the
van der Waals interaction. We present additional measurements on pure atomic
samples in order to check for the presence of a resonant loss feature related
to an avalanche effect as suggested by observations in other atomic species. We
could not confirm the presence of such a feature.",1406.3443v1
2014-06-19,Search For Higgs Boson Pair Production in the $γγb\bar{b}$ Final State using $pp$ Collision Data at $\sqrt{s}=8$ TeV from the ATLAS Detector,"Searches are performed for resonant and non-resonant Higgs boson pair
production in the $\gamma\gamma b\bar{b}$ final state using 20 fb$^{-1}$ of
proton-proton collisions at a center-of-mass energy of 8 TeV recorded with the
ATLAS detector at the CERN Large Hadron Collider. A 95% confidence level upper
limit on the cross section times branching ratio of non-resonant production is
set at 2.2 pb, while the expected limit is 1.0 pb. The difference derives from
a modest excess of events, corresponding to 2.4 standard deviations from the
background-only hypothesis. The limit observed in the search for a narrow $X
\to hh$ resonance ranges between 0.7 and 3.5 pb as a function of the resonance
mass.",1406.5053v4
2015-12-02,Influence of nanoparticle-graphene separation on the localized surface plasmon resonances of metal nanoparticles,"We develop a theory to model the interaction of graphene substrate with
localized plasmon resonances in metallic nanoparticles. The influence of a
graphene substrate on the surface plasmon resonances is described using an
effective background permittivity that is derived from a pseudoparticle concept
using the electrostatic method. For this purpose, the interaction of metal
nanoparticle with graphene sheet is studied to obtain the optical spectrum of
gold nanoparticles deposited on a graphene substrate. Then, we introduce a
factor based on dipole approximation to predict the influence of the separation
of nanoparticles and graphene on the spectral position of the localized plasmon
resonance of the nanoparticles. We applied the theory for a 4 nm radius gold
nanosphere placed near 1.5 nm graphene layer. It is shown that a blue shift is
emerged in the position of plasmon resonance when the nanoparticle moves away
from graphene.",1512.00685v1
2015-12-03,Search for narrow resonances decaying to dijets in proton-proton collisions at sqrt(s) = 13 TeV,"A search for narrow resonances in proton-proton collisions at sqrt(s) = 13
TeV is presented. The invariant mass distribution of the two leading jets is
measured with the CMS detector using a data set corresponding to an integrated
luminosity of 2.4 inverse femtobarns. The highest observed dijet mass is 6.1
TeV. The distribution is smooth and no evidence for resonant particles is
observed. Upper limits at 95% confidence level are set on the production cross
section for narrow resonances with masses above 1.5 TeV. When interpreted in
the context of specific models, the limits exclude string resonances with
masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons
below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV,
and W' bosons below 2.6 TeV. These results significantly extend previously
published limits.",1512.01224v2
2015-12-18,Competing Turing and Faraday instabilities in longitudinally modulated passive resonators,"We experimentally investigate the interplay of Turing and Faraday
(modulational) instabilities in a bistable passive nonlinear resonator. The
Faraday branch is induced via parametric resonance owing to a periodic
modulation of the resonator dispersion. We show that the bistable switching
dynamics is dramatically affected by the competition between the two
instability mechanisms, which dictates two completely novel scenarios. At low
detunings from resonance switching occurs between the stable stationary lower
branch and the Faraday-unstable upper branch, whereas at high detunings we
observe the crossover between the Turing and Faraday periodic structures. The
results are well explained in terms of the universal Lugiato-Lefever model.",1512.06055v2
2015-12-21,One jet to rule them all: monojet constraints and invisible decays of a 750 GeV diphoton resonance,"The ATLAS and CMS collaborations recently reported a mild excess in the
diphoton final state pointing to a resonance with a mass of around 750 GeV and
a potentially large width. We consider the possibility of a scalar resonance
being produced via gluon fusion and decaying to electroweak gauge bosons, jets
and pairs of invisible particles, stable at collider scales. We compute limits
from monojet searches on such a resonance and test their compatibility with the
requirement for a large width. We also study whether the stable particle can be
a a dark matter candidate and investigate the corresponding relic density
constraints along with the collider limits. We show that monojet searches rule
out a large part of the available parameter space and point out scenarios where
a broad diphoton resonance can be reconciled with monojet constraints.",1512.06842v3
2015-12-22,Vector Leptoquarks and the 750 GeV Diphoton Resonance at the LHC,"The ATLAS and CMS collaborations recently presented evidence of a resonance
decaying to pairs of photons around 750 GeV. In addition, the BaBar, Belle, and
LHCb collaborations have evidence of lepton non-universality in the
semileptonic decays of $B$ mesons. In this work, we make a first step towards a
unified explanation of these anomalies. Specifically, we extend the Standard
Model by including vector leptoquarks and a scalar singlet that couples
linearly to pairs of the leptoquarks. We find there is parameter space that
gives the correct cross section for a putative 750 GeV resonance decaying to
photons that is consistent with unitarity, measurements of the properties of
the 125 GeV Higgs boson, and direct searches for resonances in other channels.
In addition, we also show that constraints can be derived on any Beyond the
Standard Model explanation of the 750 GeV resonance where the only new
particles are scalars, which are strong enough to rule out certain types of
models entirely.",1512.06976v4
2015-12-30,Revisiting Scalar Quark Hidden Sector in Light of 750-GeV Diphoton Resonance,"In this short note, we revisit the model of a CP-even singlet scalar
resonance proposed in arXiv:1507.02483, where the resonance appears as the
lightest composite state made of scalar quarks participating in hidden strong
dynamics. We show that the model can consistently explain the excess of
diphoton events with an invariant mass around 750GeV reported by both the ATLAS
and CMS experiments. We also discuss the nature of the charged composite states
in the TeV range which accompany to the neutral scalar. Due to inseparability
of the dynamical scale and the mass of the resonance, the model also predicts
signatures associated with the hidden dynamics such as leptons, jets along with
multiple photons at future collider experiments. We also associate the
TeV-scale dynamics behind the resonance with an explanation of dark matter.",1512.08895v2
2016-05-01,"III-V semiconductor nano-resonators-a new strategy for passive, active, and nonlinear all-dielectric metamaterials","Metamaterials comprising assemblies of dielectric resonators have attracted
much attention due to their low intrinsic loss and isotropic optical response.
In particular, metasurfaces made from silicon dielectric resonators have shown
desirable behaviors such as efficient nonlinear optical conversion, spectral
filtering and advanced wave-front engineering. To further explore the potential
of dielectric metamaterials, we present all-dielectric metamaterials fabricated
from epitaxially grown III-V semiconductors that can exploit the high
second-order optical susceptibilities of III-V semiconductors, as well as the
ease of monolithically integrating active/gain media. Specifically, we create
GaAs nano-resonators using a selective wet oxidation process that forms a low
refractive index AlGaO (n~1.6) under layer similar to silicon dielectric
resonators formed using silicon-on-insulator wafers. We further use the same
fabrication processes to demonstrate multilayer III-V dielectric resonator
arrays that provide us with new degrees of freedom in device engineering. For
these arrays, we experimentally measure ~100% reflectivity over a broad
spectral range. We envision that all-dielectric III-V semiconductor
metamaterials will open up new avenues for passive, active and nonlinear all
dielectric metamaterials",1605.00298v1
2016-05-02,Isospin decomposition of $γN \to N^*$ transitions within a dynamical coupled-channels model,"By extending the dynamical coupled-channels analysis performed in our
previous work [Phys. Rev. C 88, 035209 (2013)] to include the available data of
photoproduction of pi meson off the neutron, the transition amplitudes for the
photo-excitation of the neutron to nucleon resonances, gamma n --> N*, at the
resonance pole positions are determined. The combined fits to the data for both
the proton- and neutron-target reactions also revise our results for the
resonance pole positions and the gamma p --> N* transition amplitudes. Our
results allow an isospin decomposition of the gamma N --> N* transition
amplitudes for the isospin I=1/2 N* resonances, which is necessary for testing
hadron structure models and gives crucial inputs for constructing models of
neutrino-induced reactions in the nucleon resonance region.",1605.00363v2
2016-05-03,Proposal for a quantum delayed-choice experiment with a spin-mechanical setup,"We describe an experimentally feasible protocol for performing a variant of
the quantum delayed-choice experiment with massive objects. In this scheme, a
single nitrogen-vacancy (NV) center in diamond driven by microwave fields is
dispersively coupled to a massive mechanical resonator. A double-pulse Ramsey
interferometer can be implemented with the spin-mechanical setup, where the
second Ramsey microwave pulse drives the spin conditioned on the number states
of the resonator. The probability for finding the NV center in definite spin
states exhibits interference fringes when the mechanical resonator is prepared
in a specific number state. On the other hand, the interference is destroyed if
the mechanical resonator stays in some other number states. The wavelike and
particlelike behavior of the NV spin can be superposed by preparing the
mechanical resonator in a superposition of two distinct number states. Thus a
quantum version of Wheeler's delayed-choice experiment could be implemented,
allowing of fundamental tests of quantum mechanics on a macroscopic scale.",1605.00935v2
2016-05-09,"Absolute hydrogen depth profiling using the resonant $^{1}$H($^{15}$N,$αγ$)$^{12}$C nuclear reaction","Resonant nuclear reactions are a powerful tool for the determination of the
amount and profile of hydrogen in thin layers of material. Usually, this tool
requires the use of a standard of well-known composition. The present work, by
contrast, deals with standard-less hydrogen depth profiling. This approach
requires precise nuclear data, e.g. on the widely used
$^{1}$H($^{15}$N,$\alpha\gamma$)$^{12}$C reaction, resonant at 6.4\,MeV
$^{15}$N beam energy. Here, the strongly anisotropic angular distribution of
the emitted $\gamma$-rays from this resonance has been re-measured, resolving a
previous discrepancy. Coefficients of (0.38$\pm$0.04) and (0.80$\pm$0.04) have
been deduced for the second and fourth order Legendre polynomials,
respectively. In addition, the resonance strength has been re-evaluated to
(25.0$\pm$1.5)\,eV, 10\% higher than previously reported. A simple working
formula for the hydrogen concentration is given for cases with known
$\gamma$-ray detection efficiency. Finally, the absolute approach is
illustrated using two examples.",1605.02526v1
2016-05-12,Multiphoton controllable transport between remote resonators,"We develop a novel method for multiphoton controllable transport between
remote resonators. Specifically, an auxiliary resonator is used to control the
coherent long-range coupling of two spatially separated resonators, mediated by
a coupled-resonator chain of arbitrary length. In this manner, an arbitrary
multiphoton quantum state can be either transmitted through or reflected off
the intermediate chain on demand, with very high fidelity. We find, on using a
time-independent perturbative treatment, that quantum information leakage of an
arbitrary Fock state is limited by two upper bounds, one for the transmitted
case and the other for the reflected case. In principle, the two upper bounds
can be made arbitrarily small, which is confirmed by numerical simulations.",1605.03775v2
2016-05-16,The arithmetic geometry of resonant Rossby wave triads,"Linear wave solutions to the Charney-Hasegawa-Mima partial differential
equation with periodic boundary conditions have two physical interpretations:
Rossby (atmospheric) waves, and drift (plasma) waves in a tokamak. These waves
display resonance in triads. In the case of infinite Rossby deformation radius,
the set of resonant triads may be described as the set of integer solutions to
a particular homogeneous Diophantine equation, or as the set of rational points
on a projective surface. We give a rational parametrization of the smooth
points on this surface, answering the question: What are all resonant triads?
We also give a fiberwise description, yielding a procedure to answer the
question: For fixed $r \in \mathbb{Q}$, what are all wavevectors $(x,y)$ that
resonate with a wavevector $(a,b)$ with $a/b = r$?",1605.04637v3
2016-05-16,Polarization and dilepton anisotropy in pion-nucleon collisions,"Hadronic polarization and the related anisotropy of the dilepton angular
distribution are studied for the reaction $\pi N \rightarrow Ne^+ e^-$. We
employ consistent effective interactions for baryon resonances up to spin-5/2,
where non-physical degrees of freedom are eliminated, to compute the anisotropy
coefficients for isolated intermediate baryon resonances. It is shown that the
spin and parity of the intermediate baryon resonance is reflected in the
angular dependence of the anisotropy coefficient. We then compute the
anisotropy coefficient including the $N(1520)$ and $N(1440)$ resonances, which
are essential at the collision energy of the recent data obtained by the HADES
collaboration on this reaction. We conclude that the anisotropy coefficient
provides useful constraints for unravelling the resonance contributions to this
process.",1605.04954v2
2016-05-17,Resonant optomechanics with a vibrating carbon nanotube and a radio-frequency cavity,"In an optomechanical setup, the coupling between cavity and resonator can be
increased by tuning them to the same frequency. We study this interaction
between a carbon nanotube resonator and a radio-frequency circuit. In this
resonant regime, the vacuum optomechanical coupling is enhanced by the DC
voltage coupling the cavity and the mechanical resonator. Using the cavity to
detect the nanotube's motion, we observe and simulate interference between
mechanical and electrical oscillations. We measure the mechanical ring-down and
show that further improvements to the system could enable measurement of
mechanical motion at the quantum limit.",1605.05306v2
2016-05-24,A quick method to identify secular resonances in multi-planet systems with a binary companion,"Gravitational perturbations in multi-planet systems caused by an accompanying
star are the subject of this investigation. Our dynamical model is based on the
binary star HD41004 AB where a giant planet orbits HD41004 A. We modify the
orbital parameters of this system and analyze the motion of a hypothetical
test-planet surrounding HD41004 A on an interior orbit to the detected giant
planet. Our numerical computations indicate perturbations due to mean motion
and secular resonances. The locations of these resonances are usually connected
to high eccentricity and highly inclined motion depending strongly on the
binary-planet architecture.As the positions of mean motion resonances can
easily be determined, the main purpose of this study is to present a new
semi-analytical method to determine the location of a secular resonance without
huge computational effort.",1605.07359v2
2016-05-27,Multi-step production of a diphoton resonance,"Among the questions that would be raised by the observation of a new
resonance at the LHC, particularly pressing are those concerning the production
mechanism: What is the initial state? Is the resonance produced independently
or in association with other particles? Here we present two weakly-coupled
renormalizable models for production of a diphoton resonance that differ in
both their initial and final states. In one model, a scalar particle produced
through gluon fusion decays into a diphoton particle and a light, long-lived
pseudoscalar. In another model, a $Z'$ boson produced from the annihilation of
a strange-antistrange quark pair undergoes a cascade decay that leads to a
diphoton particle and two sterile neutrinos. Various kinematic distributions
may differentiate these models from the canonical model where a diphoton
particle is directly produced in gluon fusion.",1605.08772v2
2016-05-29,Marginal resonances and intermittent behaviour in the motion in the vicinity of a separatrix,"A condition upon which sporadic bursts (intermittent behaviour) of the
relative energy become possible is derived for the motion in the chaotic layer
around the separatrix of non-linear resonance. This is a condition for the
existence of a marginal resonance, i.e. a resonance located at the border of
the layer. A separatrix map in Chirikov's form [Chirikov, B. V., Phys. Reports
52, 263 (1979)] is used to describe the motion. In order to provide a
straightforward comparison with numeric integrations, the separatrix map is
synchronized to the surface of the section farthest from the saddle point. The
condition of intermittency is applied to clear out the nature of the phenomenon
of bursts of the eccentricity of chaotic asteroidal trajectories in the 3/1
mean motion commensurability with Jupiter. On the basis of the condition, a new
intermittent regime of resonant asteroidal motion is predicted and then
identified in numeric simulations.",1605.08986v1
2016-08-01,Observation of optomechanical coupling in a microbottle resonator,"In this work, we report optomechanical coupling, resolved sidebands and
phonon lasing in a solid-core microbottle resonator fabricated on a single mode
optical fiber. Mechanical modes with quality factors (Q_m) as high as 1.57*10^4
and 1.45*10^4 were observed, respectively, at the mechanical frequencies
f_m=33.7 MHz and f_m=58.9 MHz. The maximum f_m*Q_m~0.85*10^12 Hz is close to
the theoretical lower bound of 6*10^12 Hz needed to overcome thermal
decoherence for resolved-sideband cooling of mechanical motion at room
temperature, suggesting microbottle resonators as a possible platform for this
endeavor. In addition to optomechanical effects, scatter-induced mode splitting
and ringing phenomena, which are typical for high-quality optical resonances,
were also observed in a microbottle resonator.",1608.00286v1
2016-08-02,Ultra-coherent nanomechanical resonators via soft clamping and dissipation dilution,"The small mass and high coherence of nanomechanical resonators render them
the ultimate force probe, with applications ranging from biosensing and
magnetic resonance force microscopy, to quantum optomechanics. A notorious
challenge in these experiments is thermomechanical noise related to dissipation
through internal or external loss channels. Here, we introduce a novel approach
to defining nanomechanical modes, which simultaneously provides strong spatial
confinement, full isolation from the substrate, and dilution of the resonator
material's intrinsic dissipation by five orders of magnitude. It is based on a
phononic bandgap structure that localises the mode, without imposing the
boundary conditions of a rigid clamp. The reduced curvature in the highly
tensioned silicon nitride resonator enables mechanical $Q>10^{8}$ at $ 1
\,\mathrm{MHz}$, yielding the highest mechanical $Qf$-products
($>10^{14}\,\mathrm{Hz}$) yet reported at room temperature. The corresponding
coherence times approach those of optically trapped dielectric particles.
Extrapolation to $4{.}2$ Kelvin predicts $\sim$quanta/ms heating rates, similar
to trapped ions.",1608.00937v1
2016-08-03,A quantum optical description of losses in ring resonators based on field operator transformations,"In this work we examine loss in ring resonator networks from an ""operator
valued phasor addition"" approach (or OVPA approach) which considers the
multiple transmission and cross coupling paths of a quantum field traversing a
ring resonator coupled to one or two external waveguide buses. We demonstrate
the consistency of our approach by the preservation of the operator commutation
relation of the out-coupled bus mode. We compare our results to those obtained
from the conventional quantum Langevin approach which introduces noise
operators in addition to the quantum Heisenberg equations in order to preserve
commutation relations in the presence of loss. It is shown that the two
expressions agree in the neighborhood of a cavity resonance where the Langevin
approach is applicable, whereas the operator valued phasor addition expression
we derive is more general, remaining valid far from resonances.",1608.01280v2
2016-08-05,Mechanical dissipation in MoRe superconducting metal drums,"We experimentally investigate dissipation in mechanical resonators made of a
disordered superconducting thin film of Molybdenum-Rhenium(MoRe) alloy. By
electrostatically driving the drum with a resonant AC voltage, we detect its
motion using a superconducting microwave cavity. From the temperature
dependence of mechanical resonance frequencies and quality factors, we find
evidence for non-resonant, mechanically active two-level systems (TLSs)
limiting its quality factor at low temperature. In addition, we observe a
strong suppression of mechanical dissipation at large mechanical driving
amplitudes, suggesting an unconventional saturation of the non-resonant TLSs.
These new observations shed light on the mechanism of mechanical damping in
superconducting drums and routes towards understanding dissipation in such
mechanical systems.",1608.01871v1
2016-08-13,Pseudo-orbit approach to trajectories of resonances in quantum graphs with general vertex coupling: Fermi rule and high-energy asymptotics,"The aim of the paper is to investigate resonances in quantum graphs with a
general self-adjoint coupling in the vertices and their trajectories with
respect to varying edge lengths. We derive formulae determining the Taylor
expansion of the resonance pole position up to the second order which
represent, in particular, a counterpart to the Fermi rule derived recently by
Lee and Zworski for graphs with the standard coupling. Furthermore, we discuss
the asymptotic behavior of the resonances in the high-energy regime in the
situation where the leads are attached through $\delta$ or $\delta_\mathrm{s}'$
conditions, and we prove that in the case of $\delta_\mathrm{s}'$ coupling the
resonances approach to the real axis with the increasing real parts as
$\mathcal{O}\big((\mathrm{Re\,}k)^{-2}\big)$.",1608.03978v1
2016-08-18,Super-resonant radiation stimulated by high-harmonics,"Solitons propagating in media with higher order dispersion will shed
radiation known as dispersive wave or resonant radiation, with applications in
frequency broadening, deep UV sources for spectroscopy or simply fundamental
studies of soliton physics. Starting from a recently proposed equation that
models the behaviour of ultrashort optical pulses in nonlinear materials using
the analytic signal, we find that the resonant radiation associated with the
third-harmonic generation term of the equation is parametrically stimulated
with an unprecedented gain. Resonant radiation levels, typically only a small
fraction of the soliton, are now as intense as the soliton itself. The
mechanism is quite universal and works also in normal dispersion and with
harmonics higher than the third. We report experimental hints of this
super-resonant radiation stimulated by the fifth harmonic in diamond.",1608.05222v1
2016-08-23,Challenges in flow background removal in search for the chiral magnetic effect,"We investigate the effect of resonance decays on the three-particle
correlator charge separation observable in search for the chiral magnetic
effect, using a simple simulation with realistic inputs. We find that resonance
decays can largely account for the measured signal. We suppress the elliptic
flow ($v_2$) background by using zero event-by-event $v_2$ (or via the
mixed-event technique). We find that the background is suppressed, but not
eliminated as naively anticipated. We identify the reason to be the
non-identicalness of the resonance and final-state particle's $v_2$ and the
induced correlation between the transverse momentum dependent resonance $v_2$
and decay angle. We make predictions for the charge separation signal due to
resonance decays in 200~GeV Au+Au collisions.",1608.06610v2
2016-12-04,"Molecular organization in the twist-bend nematic phase by resonant X-ray scattering at the Se K-edge and by SAXS, WAXS and GIXRD","Using a novel Se-labelled dimer mixed with DTC5C7 aligned by magnetic field,
the twist-bend nematic phase (Ntb) in dimers was studied by hard X-ray resonant
scattering and by small and wide angle X-ray scattering (SAXS, WAXS). Resonant
diffraction spots indicated a helix with a 9-12 nm pitch in the Ntb phase.
Unprecedentedly high helix orien-tation enabled deconvolution of global and
local order parameters. This, combined with simultaneous resonant and
non-resonant SAXS and WAXS data, allowed us to construct a modified model of
the Ntb phase matching twisted molecular conformations and the local
heliconical director field.",1612.01180v1
2016-12-05,Gain enhanced Fano resonance in a coupled photonic crystal cavity-waveguide structure,"Systems with coupled cavities and waveguides have been demonstrated as
optical switches and optical sensors. To optimize the functionalities of these
optical devices, Fano resonance with asymmetric and steep spectral line shape
has been used. We theoretically propose a coupled photonic crystal
cavity-waveguide structure to achieve Fano resonance by placing partially
reflecting elements in waveguide. To enhance Fano resonance, optical gain
material is introduced into the cavity. As the gain increases, the transmission
line shape becomes steepened and the transmissivity can be six times enhanced,
giving a large contrast by a small frequency shift. It is prospected that the
gain enhanced Fano resonance is very useful for optical switches and optical
sensors.",1612.01268v1
2016-12-05,Resonator with ultra-high length stability as a probe for Equivalence-Principle-violating physics,"In order to investigate the long-term dimensional stability of matter, we
have operated an optical resonator fabricated from crystalline silicon at
1.5$\,$K continuously for over one year and repeatedly compared its resonance
frequency $f_{res}$ with the frequency of a GPS-monitored hydrogen maser. After
allowing for an initial settling time, over a 163-day interval we found a mean
fractional drift magnitude $|f_{res}^{-1}df_{res}/dt|<1.4\times10^{-20}$/s. The
resonator frequency is determined by the physical length and the speed of
light, and we measure it with respect to the atomic unit of time. Thus, the
bound rules out, to first order, a hypothetical differential effect of the
universe's expansion on rulers and atomic clocks. We also constrain a
hypothetical violation of the principle of Local Position Invariance for
resonator-based clocks and derive bounds for the strength of space-time
fluctuations.",1612.01467v1
2016-12-07,High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate,"Future quantum networks in which superconducting quantum processors are
connected via optical links, will require microwave-to-optical photon
converters that preserve entanglement. A doubly-resonant electro-optic
modulator (EOM) is a promising platform to realize this conversion. Here, we
present our progress towards building such a modulator by demonstrating the
optically-resonant half of the device. We demonstrate high quality factor ring,
disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate
material system. Optical quality factors up to 730,000 are achieved,
corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic
effect to modulate the resonance frequency of a photonic crystal cavity,
achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In
addition to quantum technology, we expect that our results will be useful both
in traditional silicon photonics applications and in high-sensitivity
acousto-optic devices.",1612.02421v1
2016-12-12,Tuning of Hybrid Oligomers via Nanoscale fs-Laser Reshaping,"Various clusters of metallic or dielectric nanoparticles can exhibit sharp
Fano resonances originating from at least two modes interference of different
spectral width. However, for practical applications such as biosensing or
nonlinear nanophotonics, the fine-tuning of the Fano resonances is generally
required. Here, we propose and demonstrate a novel type of hybrid oligomers
consisting of asymmetric metal-dielectric (Au/Si) nanoparticles with a sharp
Fano resonance in visible range, which has a predominantly magnetic origin. We
demonstrate both, numerically and experimentally, that such hybrid nanoparticle
oligomers allow fine-tuning of the Fano resonance via fs-laser induced melting
of Au nanoparticles at the nanometer scale. We show that the Fano resonance
wavelength can be changed by fs-laser reshaping very precisely (within 15~nm)
being accompanied by a reconfiguration of its profile.",1612.03555v1
2016-12-28,The production of neutral $N^*(11052)$ resonance with hidden beauty from $π^-p$ scattering,"We investigate the discovery potential of the predicted neutral hidden beauty
$N^*(11052)$ resonance through $\pi^- p$ scattering within an effective
Lagrangian approach. Two reactions $\pi^-p\rightarrow K^-\Sigma^+$ and
$\pi^-p\rightarrow \eta_bn$ are studied in this work, with nucleon pole
exchange as the background. It is found that the contributions of the
$N^*(11052)$ resonance give clear peak structures in the magnitude of 1 $\mu b$
near the threshold of the $N^*(11052)$ in the total cross sections. The
numerical results indicate that the center of mass energy $W\simeq$ 11-11.1 GeV
would be a best energy window for searching the $N^*(11052)$ resonance, where
the $N^*(11052)$ signal can be easily distinguished from the background. The
COMPASS experiment at CERN's Super Proton Synchrotron (SPS) with pion beam of
$\simeq$ 280 GeV will be an ideal platform for searching the super-heavy
resonance with hidden beauty, which is hopeful to test the theoretical results.",1612.08822v1
2016-12-29,"Search for massive resonances decaying into WW, WZ or ZZ bosons in proton-proton collisions at sqrt(s) = 13 TeV","A search is presented for new massive resonances decaying to WW, WZ or ZZ
bosons in l nu quark anti-quark and quark anti-quark quark anti-quark final
states. Results are based on data corresponding to an integrated luminosity of
2.3-2.7 inverse femtobarns recorded in proton-proton collisions at sqrt(s) = 13
TeV with the CMS detector at the LHC. Decays of spin-1 and spin-2 resonances
into two vector bosons are sought in the mass range 0.6-4.0 TeV. No significant
excess over the standard model background is observed. Combining the results of
the l nu quark anti-quark and quark anti-quark quark anti-quark final states,
cross section and mass exclusion limits are set for models that predict heavy
spin-1 and spin-2 resonances. This is the first search for a narrow-width
spin-2 resonance at sqrt(s) = 13 TeV.",1612.09159v2
2016-12-05,Resonant transitions induced in particle processes by the non-perturbative treatment of strong laser fields,"Intense field quantum field theory (IFQFT) is used to determine new
phenomenological predictions arising from Compton scattering and pair
production in a strong laser field. This theory utilizes exact solutions of
fermions embedded in external plane waves which carry over to a strong field
fermion propagator. When these strong field fermions also interact with probe
photons, the transition probability is enhanced in a series of resonances when
the kinematics allow the virtual fermion to go on-shell. An analysis of
parameters shows that contemporary experiments could already produce these
predicted resonances. With appropriate tuning, resonances can be made
arbitrarily sharp, leading to precision calculations of resonance locations and
widths, and the runing of coupling constants in strong background fields. New
tests of QED could be performed leading to ramifications for our understanding
of the quantum vacuum. Such tests extend to QFT in background potentials in
general, which may throw light on BSM theories such as QFT in curved
space-times.",1612.09294v1
2017-06-02,Linear frequency conversion via sudden merging of resonances in time-variant metasurfaces,"Energy conversion in a physical system requires time-translation invariance
breaking according to Noether's theorem. Closely associated with this
symmetry-conservation relation, the frequencies of electromagnetic waves are
found to be converted as the waves propagate through a temporally varying
medium. Thus, effective temporal control of the medium, be it artificial or
natural, through which the waves are propagating, lies at the heart of linear
optical frequency conversion. Here, we propose rapidly time-variant
metasurfaces as a frequency-conversion platform and experimentally demonstrate
their efficacy at THz frequencies. The proposed metasurface is designed for the
sudden merging of two distinct resonances into a single resonance upon
ultrafast optical excitation. From this spectrally-engineered temporal boundary
onward, the merged-resonance frequency component is radiated. In addition,
temporal coherence of the two original resonating modes with respect to the
abrupt temporal boundary is found to be strongly related to the amount of
frequency conversion as well as the phase of the converted wave. Due to their
design flexibility, time-variant metasurfaces may become on-demand frequency
synthesizers for various frequency ranges.",1706.00664v1
2017-06-07,Scattering by a periodic array of subwavelength slits I: field enhancement in the diffraction regime,"This is the first part in a series of two papers that concern with the
quantitative analysis of the electromagnetic field enhancement and anomalous
diffraction by a periodic array of subwavelength slits. The scattering problem
in the diffraction regime is investigated in this part, for which the size of
the period is comparable to the incident wavelength. We distinguish scattering
resonances and real eigenvalues, and derive their asymptotic expansions when
they are away from the Rayleigh cut-off frequencies. Furthermore, we present
quantitative analysis of the field enhancement at resonant frequencies, by
quantifying both the enhancement order and the associated resonant modes. The
field enhancement near the Rayleigh cut-off frequencies is also investigated.
It is demonstrated that the field enhancement becomes weaker at the resonant
frequency if it is close to the Rayleigh cut-off frequencies. Finally, we also
characterize the embedded eigenvalues for the underlying periodic structure,
and point out that transmission anomaly such as Fano resonant phenomenon does
not occur for the narrow slit array.",1706.02122v1
2017-06-13,Jet-associated resonance spectroscopy,"We present a model-independent study aimed at characterizing the nature of
possible resonances in the jet-photon or jet-$Z$ final state at hadron
colliders. Such resonances are expected in many models of compositeness and
would be a clear indication of new physics. At leading order, in the narrow
width approximation, the matrix elements are parameterized by just a few
constants describing the coupling of the various helicities to the resonance.
We present the full structure of such amplitudes up to spin two and use them to
simulate relevant kinematic distributions that could serve to constrain the
coupling structure. This also generalizes the signal generation strategy that
is currently pursued by ATLAS and CMS to the most general case in the
considered channels. While the determination of the P/CP properties of the
interaction seems to be out of reach within this framework, there is a wealth
of information to be gained about the spin of the resonance and the relative
couplings of the helicities.",1706.04242v2
2017-06-17,Formation and decay of resonance state in $^{9}$Be and $^{9}$B nuclei. Microscopic three-cluster model investigations,"We study nature of the low-lying resonance states in mirror nuclei $^{9}$Be
and $^{9}$B. Investigations are performed within a three-cluster model. The
model makes use of the hyperspherical harmonics, which provides convenient
description of three-cluster continuum. The dominant three-cluster
configurations $\alpha+\alpha+n$ and $\alpha+\alpha+p$ in $^{9}$Be and $^{9}$B,
respectively, are taken into account. Dominant decay channels for all resonance
states in $^{9}$Be and $^{9}$B are explored. Much attention is paid to the
controversial $1/2^{+}$ resonance states in both nuclei. We study effects of
the Coulomb interaction on energy and width of three-cluster resonances in the
mirror nuclei $^{9}$Be and $^{9}$B. We also search for the Hoyle-analogue state
which is a key step for alternative way of $^{9}$Be and $^{9}$B syntheses in a
triple collision of clusters in a stellar environment.",1706.05514v1
2017-06-27,Gigahertz optomechanical modulation by split-ring-resonator nanophotonic meta-atom arrays,"Using polarization-resolved transient reflection spectroscopy, we investigate
the ultrafast modulation of light interacting with a metasurface consisting of
coherently vibrating nanophotonic meta-atoms in the form of U-shaped split-ring
resonators, that exhibit co-localized optical and mechanical resonances. With a
two-dimensional square-lattice array of these resonators formed of gold on a
glass substrate, we monitor the visible-pump-pulse induced gigahertz
oscillations in intensity of reflected linearly-polarized infrared probe light
pulses, modulated by the resonators effectively acting as miniature tuning
forks. A multimodal vibrational response involving the opening and closing
motion of the split rings is detected in this way. Numerical simulations of the
associated transient deformations and strain fields elucidate the complex
nanomechanical dynamics contributing to the ultrafast optical modulation, and
point to the role of acousto-plasmonic interactions through the opening and
closing motion of the SRR gaps as the dominant effect. Applications include
ultrafast acoustooptic modulator design and sensing.",1706.08909v1
2017-06-30,Fano resonance via bonding and antibonding states in nonadiabatically-pumped double-quantum-well systems,"In this work, transport properties of the nonadiabatically pumped
double-quantum-well (DQW) structure are studied. Different from a single
quantum well, band mixing in the DQW generates bonding and antibonding states,
whose wave functions have different spatial symmetry. By applying a
time-dependent electric potential to the two well regions simultaneously,
Floquet sidebands are formed, which constitutes additional quantum tunneling
paths. When one of the Floquet sidebands coincides with the bonding or
antibonding quasibound states within the DQW structure, sharp Fano resonances
are found in the transmission coefficients as well as in the differential shot
noise spectra. While such Fano resonances originate from quantum interference,
their shapes are strikingly different for transport via the bonding state and
via the antibonding state. The Fano resonance via the even-parity bonding state
shows a perfect transmission followed by a total reflection and the Fano
resonance via the odd-parity antibonding state has a reversed symmetry and
shows a total reflection before a perfect transmission.",1706.10001v1
2017-06-30,A QCD Sum-Rules Analysis of Vector ($1^{--}$) Heavy Quarkonium Meson-Hybrid Mixing,"We use QCD Laplace sum-rules to study meson-hybrid mixing in vector
($1^{--}$) heavy quarkonium. We compute the QCD cross-correlator between a
heavy meson current and a heavy hybrid current within the operator product
expansion. In addition to leading-order perturbation theory, we include four-
and six-dimensional gluon condensate contributions as well as a six-dimensional
quark condensate contribution. We construct several single and multi-resonance
models that take known hadron masses as inputs. We investigate which resonances
couple to both currents and so exhibit meson-hybrid mixing. Compared to single
resonance models that include only the ground state, we find that models that
also include excited states lead to significantly improved agreement between
QCD and experiment. In the charmonium sector, we find that meson-hybrid mixing
is consistent with a two-resonance model consisting of the $J/\psi$ and a
4.3~GeV resonance. In the bottomonium sector, we find evidence for meson-hybrid
mixing in the $\Upsilon(1S)$, $\Upsilon(2S)$, $\Upsilon(3S)$, and
$\Upsilon(4S)$.",1707.00063v2
2017-07-02,Research on the halo in $^{31}$Ne with complex momentum representation method,"Halo is one of the most interesting phenomena in exotic nuclei especially for
$^{31}$Ne, which is deemed to be a halo nucleus formed by a $p-$wave resonance.
However, the theoretical calculations don't suggest a $p-$wave resonance using
the scattering phase shift approach or complex scaling method. Here, we apply
the complex momentum representation method to explore resonances in $^{31}$Ne.
We have calculated the single-particle energies for bound and resonant states
together with their evolutions with deformation. The results show that the
$p-$wave resonances appear clearly in the complex momentum plane accompanied
with the $p-f$ inversion in the single-particle levels. As it happens the $p-f$
inversion, the calculated energy, width, and occupation probabilities of major
components in the level occupied by valance neutron support a $p-$wave halo for
$^{31}$Ne.",1707.00246v1
2017-07-04,High-Resolution Nanoscale Solid-State Nuclear Magnetic Resonance Spectroscopy,"We present a new method for high-resolution nanoscale magnetic resonance
imaging (nano-MRI) that combines the high spin sensitivity of nanowire-based
magnetic resonance detection with high spectral resolution nuclear magnetic
resonance (NMR) spectroscopy. By applying NMR pulses designed using optimal
control theory, we demonstrate a factor of $500$ reduction of the proton spin
resonance linewidth in a $(50\text{-nm})^{\text{3}}$ volume of polystyrene and
image proton spins in one dimension with a spatial resolution below
$2~\text{nm}$.",1707.01062v1
2017-07-07,Color reconnection effects on resonance production,"We present studies that show how multi-parton interaction and color
reconnection affect the hadro-chemistry in proton-proton (pp) collisions with
special focus on the production of resonances using the PYTHIA8 event
generator. We find that color reconnection suppresses the relative production
of meson resonances such as $\rho_{0}$ and K*, providing an alternative
explanation for the K*/K decrease observed in proton-proton collisions as a
function of multiplicity by the ALICE collaboration. Detailed studies of the
underlying mechanism causing meson resonance suppression indicate that color
reconnection leads to shorter, less energetic strings whose fragmentation is
less likely to produce more massive hadrons for a given quark content,
therefore reducing ratios such as K*/K and $\rho_0/\pi$ in high-multiplicity pp
collisions. In addition, we have also studied the effects of allowing string
junctions to form and found that these may also contribute to resonance
suppression.",1707.02075v3
2017-07-10,Strong 4-mode coupling of nanomechanical string resonators,"We investigate mechanical mode coupling between the four fundamental flexural
modes of two doubly-clamped, high-Q silicon-nitride nanomechanical string
resonators. Strong mechanical coupling between the strings is induced by the
strain mediated via a shared clamping point, engineered to increase the
exchange of oscillatory energy. One of the resonators is controlled
dielectrically, which results in strong coupling between its out-of-plane and
in-plane flexural modes. We show both, inter-string out-of-plane-in-plane and
3-mode resonance of the four coupled fundamental vibrational modes of a
resonator pair, giving rise to a simple and a multimode avoided crossing,
respectively.",1707.02926v3
2017-07-11,Hole spin resonance and spin-orbit coupling in a silicon metal-oxide-semiconductor field-effect transistor,"We study hole spin resonance in a p-channel silicon metal-oxide-semiconductor
field-effect transistor. In the sub-threshold region, the measured source-drain
current reveals a double dot in the channel. The observed spin resonance
spectra agree with a model of strongly coupled two-spin states in the presence
of a spin-orbit-induced anti-crossing. Detailed spectroscopy at the
anti-crossing shows a suppressed spin resonance signal due to
spin-orbit-induced quantum state mixing. This suppression is also observed for
multi-photon spin resonances. Our experimental observations agree with
theoretical calculations.",1707.03106v1
2017-07-14,On Nematicity and Charge Order in Superoxygenated La$_{2-x}$Sr$_x$CuO$_{4+y}$,"A nematic order in stripe-ordered cuprates was recently identified with (001)
reflection at resonant energies associated with the in-plane states. However,
whether this resonant reflection is ubiquitous among all 214 cuprates is still
unknown. Here we report a Resonant soft X-ray Scattering (RXS) measurement on
two La$_{2-x}$Sr$_x$CuO$_{4+y}$ crystals. Charge order was found in
La$_2$CuO$_{4+y}$ with a total hole concentration near 0.125/Cu but no
measurable (001) peak at any resonance, while in a
La$_{1.94}$Sr$_{0.06}$CuO$_{4+y}$ sample near 0.16/Cu a (001) peak resonant was
identified to be consistent with the presence of LTT tilting. The lack of such
a (001) peak in a compound with stripe-like charge order raises questions about
nematicity and the origin of the scattering feature.",1707.04367v2
2017-07-14,Orientational Effects on the Amplitude and Phase of Polarimeter Signals in Double Resonance Atomic Magnetometry,"Double resonance optically pumped magnetometry can be used to measure static
magnetic fields with high sensitivity by detecting a resonant atomic spin
response to a small oscillating field perturbation. Determination of the
resonant frequency yields a scalar measurement of static field ($B_0$)
magnitude. We present calculations and experimental data showing that the
on-resonance polarimeter signal of light transmitted through an atomic vapour
in arbitrarily oriented $B_0$ may be modelled by considering the evolution of
alignment terms in atomic polarisation. We observe that the amplitude and phase
of the magnetometer signal are highly dependent upon $B_0$ orientation, and
present precise measurements of the distribution of these parameters over the
full 4{\pi} solid angle.",1707.04418v1
2017-07-22,Subwavelength sound screening by coupling space-coiled Fabry-Perot resonators,"We explore broadband and omnidirectional low frequency sound screening based
on locally resonant acoustic metamaterials. We show that the coupling of
different resonant modes supported by Fabry-Perot cavities can efficiently
generate asymmetric lineshapes in the transmission spectrum, leading to a
broadband sound opacity. The Fabry-Perot cavities are space-coiled in order to
shift the resonant modes under the diffraction edge, which guaranty the opacity
band for all incident angles. Indeed, the deep subwavelength feature of the
cavities leads to avoid diffraction that have been proved to be the main
limitation of omnidirectional capabilities of locally resonant perforated
plates. We experimentally reach an attenuation of few tens of dB at low
frequency, with a metamaterial thickness fifteen times smaller than the
wavelength (lambda / 15). The proposed design can be considered as a new
building block for acoustic metasurfaces having a high level of manipulation of
acoustic waves.",1707.07208v1
2017-07-24,Multi-angle calculation of the matter-neutrino resonance near an accretion disk,"We perform a numerical study of the matter-neutrino resonance in a
multi-angle calculation in the vicinity of an accretion disk. We assume
thermally distributed neutrino and anti-neutrino fields emitted by
two-dimensional disk that is homogeneous and isotropic; the electrons are
assumed to be at constant density. We compare the the result of this
computation to that obtained using single-angle approximation. We investigate
the robustness of matter-neutrino resonance in environment surrounding
accretion disks by progressively relaxing the single angle approximation. We
find that the multi-angle results in the present simplified model do not
support a robust resonance mechanism as suggested by the single angle
treatment. We also discuss the context under which matter-neutrino resonance
may be important in future studies.",1707.07692v2
2017-10-09,Weak magnetic anisotropy in GdRh$_2$Si$_2$ studied by magnetic resonance,"The antiferromagnetically (AFM) ordered state of GdRh$_{2}$Si$_{2}$ which
consists of AFM-stacked ferromagnetic layers is investigated by magnetic
resonance spectroscopy. The almost isotropic Gd$^{3+}$ paramagnetic resonance
becomes anisotropic in the AFM ordered region below 107 K. The emerging
internal anisotropic exchange-fields are still small enough to allow an
investigation of their magnetization dynamics by using a standard
microwave-frequency magnetic resonance technique. We could characterize this
anisotropy in detail in the ferromagnetic layers of the excitation at 9 and 34
GHz. We derived a resonance condition for the AFM ordered phase to describe the
weak in-plane anisotropic behaviour in combination with a mean-field analysis.",1710.03079v1
2017-10-09,Resonant absorption of surface sausage and surface kink modes under photospheric conditions,"We study the effect of resonant absorption of surface sausage and surface
kink modes under photospheric conditions where the slow surface sausage modes
undergo resonant damping in the slow continuum and the surface kink modes in
the slow and Alfv\'{e}n continua at the transitional layers. We use recently
derived analytical formulas to obtain the damping rate (time). By considering
linear density and linear pressure profiles for the transitional layers, we
show that resonant absorption in the slow continuum could be an efficient
mechanism for the wave damping of the slow surface sausage and slow surface
kink modes whilst the damping rate of the slow surface kink mode in the
Alfv\'{e}n continuum is weak. It is also found that the resonant damping of the
fast surface kink mode is much stronger than that of the slow surface kink
mode, showing a similar efficiency as under coronal conditions. It is worth to
notice that the slow body sausage and kink modes can also resonantly damp in
the slow continuum for those linear profiles.",1710.03350v2
2017-10-01,"Elastic metamaterial with simultaneously negative Mass Density, Bulk Modulus and Shear Modulus","We present a study of elastic metamaterial that possesses multiple local
resonances. We demonstrated that the elastic metamaterial can have
simultaneously three negative effective parameters, i.e., negative effective
mass, effective bulk modulus and effective shear modulus at a certain frequency
range. Through the analysis of the resonant field, it has been elucidated that
the three negative parameters are induced by dipolar, monopolar and quadrupolar
resonance respectively. The dipolar and monopolar resonances result into the
negative band for longitudinal waves, while the dipolar and quadrupolar
resonances cause the negative band for transverse waves. The two bands have an
overlapping frequency regime. A simultaneously negative refraction for both
longitudinal waves and transverse waves has been demonstrated in the system.",1710.03681v1
2017-10-12,Resonant Mode Conversion of the Second Sound to the First Sound in Liquid Helium II,"The experimentally observed disappearance below T = 0.5K of the second sound
in liquid He II as a separate wave mode and its subsequent propagation at the
speed of the first sound (Peshkov [3]) may be interpreted as a resonant mode
conversion of the second sound to the first sound. Near the resonant mode
coupling point T = T*, where the frequencies of the two waves become equal, the
anomalous effect of entropy changes on the first sound and density changes on
the second sound, though generally small, become significant. This leads to the
resonant mode coupling of the first sound and the second sound and forces them
to lose their identities and hence pave the way for the resonant mode
conversion of the second sound to the first sound. We give a theoretical
framework for this proposition and an estimate for the fraction of the second
sound that is mode-converted to the first sound.",1710.04593v2
2017-10-12,Scattering of flexural waves from an $N$-beam resonator in a thin plate,"The impedance matrix method is applied to study the scattering of flexural
waves propagating in an infinite thin plate containing an $N$-beam resonator.
The resonator consists of a circular hole containing a smaller plate connected
to the background plate by a number $N$ of rectangular beams. After
representing the boundary conditions in a modal multipole expansion form, a
compact expression is obtained for the T-matrix, which relates the incident and
the scattered transverse (out-of-plane) waves. The analysis of the scattering
cross-section reveals interesting scattering features, like resonances and
anisotropy, associated with this type of resonators. Numerical experiments
performed within the framework of the finite element method support the
accuracy of the model here developed.",1710.04610v1
2017-10-18,Polarized bound state in the continuum and resonances with tunable Q-factor in an anisotropic photonic crystal,"We consider a one-dimensional photonic crystal composed of alternating layers
of isotropic and anisotropic dielectric materials. Such a system has different
band structures for different polarizations of light. We demonstrate that if an
anisotropic defect layer is inserted into the structure, the crystal can
support an optical bound state in the continuum. By tilting the principle
dielectric axes of the defect layer relative to those of the photonic crystal
we observe a long-lived resonance in the transmission spectrum. We derive an
analytical expression for the decay rate of the resonance that agrees well with
the numerical data by the Berreman anisotropic transfer matrix approach. An
experimental set-up with a liquid crystal defect layer is proposed to tune the
Q-factor of the resonance through applying an external electric field. We
speculate that the set-up provides a simple and robust platform for observing
optical bound states in the continuum in the form of resonances with tunable
Q-factor.",1710.06575v1
2017-10-24,Functional meta-optics and nanophotonics govern by Mie resonances,"Scattering of electromagnetic waves by subwavelength objects is accompanied
by the excitation of electric and magnetic Mie resonances, that may modify
substantially the scattering intensity and radiation pattern. Scattered fields
can be decomposed into electric and magnetic multipoles, and the magnetic
multipoles define magnetic response of structured materials underpinning the
new field of all-dielectric resonant meta-optics. Here we review the recent
developments in meta-optics and nanophotonics, and demonstrate that the Mie
resonances can play a crucial role offering novel ways for the enhancement of
many optical effects near magnetic and electric multipolar resonances, as well
as driving a variety of interference phenomena which govern recently discovered
novel effects in nanophotonics. We further discuss the frontiers of
all-dielectric meta-optics for flexible and advanced control of light with full
phase and amplitude engineering, including nonlinear nanophotonics, anapole
nanolasers, quantum tomography, and topological photonics.",1710.08595v1
2017-10-27,Spectroscopy and Biosensing with Optically Resonant Dielectric Nanostructures,"Resonant dielectric nanoparticles (RDNs) made of materials with large
positive dielectric permittivity, such as Si, GaP, GaAs, have become a powerful
platform for modern light science, enabling various fascinating applications in
nanophotonics and quantum optics. In addition to light localization at the
nanoscale, dielectric nanostructures provide electric and magnetic resonant
responses throughout the visible and infrared spectrum, low dissipative losses
and optical heating, low doping effect and absence of quenching, which are
interesting for spectroscopy and biosensing applications. In this review, we
present state-of-the-art applications of optically resonant high-index
dielectric nanostructures as a multifunctional platform for light-matter
interactions. Nanoscale control of quantum emitters and applications for
enhanced spectroscopy including fluorescence spectroscopy, surface-enhanced
Raman scattering (SERS), biosensing, and lab-on-a-chip technology are surveyed.
We describe the theoretical background underlying these effects, overview
realizations of specific resonant dielectric nanostructures and hybrid
excitonic systems, and outlook the challenges in this field, which remain open
to future research.",1710.10233v1
2017-12-02,Phonon-interference resonance effects in nanoparticles embedded in a matrix,"We report an unambiguous phonon resonance effect originating from germanium
nanoparticles embedded in silicon matrix. Our approach features the combination
of phonon wave-packet method with atomistic dynamics and finite element method
rooted in continuum theory. We find that multimodal phonon resonance, caused by
destructive interference of coherent lattice waves propagating through and
around the nanoparticle, gives rise to sharp and significant transmittance
dips, blocking the lower-end frequency range of phonon transport that is hardly
diminished by other nanostructures. The resonance is sensitive to the phonon
coherent length, where the finiteness of the wave packet width weakens the
transmittance dip even when coherent length is longer than the particle
diameter. Further strengthening of transmittance dips are possible by arraying
multiple nanoparticles that gives rise to the collective vibrational mode.
Finally, it is demonstrated that these resonance effects can significantly
reduce thermal conductance in the lower-end frequency range.",1712.00564v1
2017-12-04,Femtosecond pulse with THz repetition frequency based on strong coupling between quantum emitters and a plasmonic resonator,"Nanoscale pulsed light is highly desirable in nano-integrated optics. In this
letter, we obtained femtosecond pulses with THz repetition frequency via the
strong coupling between quantum emitters (QEs) and plasmonic resonators. Our
structure consists of a V-groove (VG) plasmonic resonator and a nanowire
embedded with two-level QEs. The influences of the incident light intensity and
QE number density on the transmission response for this hybrid system are
investigated through semi-classical theory and simulation. It is found that the
transmission response can be modulated to the pulse form. The reason is the
strong coupling causes the output power of nanowire to behave as an oscillating
form, the oscillating output power in turn causes the field amplitude in the
resonator to oscillate over time. A feedback system is formed between the
plasmonic resonator and the QEs in nanowire. This provides a new method for
generating narrow pulsed lasers with ultrahigh repetition frequency in
plasmonic systems using a continous wave input, which has potential
applications in generating optical clock signals at the nanoscale.",1712.00958v3
2017-12-04,Resonance oscillation of a damped driven simple pendulum,"The resonance characteristics of a driven damped harmonic oscillator are well
known. Unlike harmonic oscillators which are guided by parabolic potentials, a
simple pendulum oscillates under sinusoidal potentials. The problem of an
undamped pendulum has been investigated to a great extent. However, the
resonance characteristics of a driven damped pendulum have not been re- ported
so far due to the difficulty in solving the problem analytically. In the
present work we report the resonance characteristics of a driven damped
pendulum calculated numerically. The results are compared with the resonance
characteristics of a damped driven harmonic oscillator. The work can be of
pedagogic interest too as it reveals the richness of driven damped motion of a
simple pendulum in comparison to and how strikingly it differs from the motion
of a driven damped harmonic oscillator. We confine our work only to the
nonchaotic regime of pendulum motion.",1712.01032v1
2017-12-08,Realizing a Circuit Analog of an Optomechanical System with Longitudinally Coupled Superconducting Resonators,"We realize a superconducting circuit analog of the generic
cavity-optomechanical Hamiltonian by longitudinally coupling two
superconducting resonators, which are an order of magnitude different in
frequency. We achieve longitudinal coupling by embedding a superconducting
quantum interference device (SQUID) into a high frequency resonator, making its
resonance frequency depend on the zero point current fluctuations of a nearby
low frequency LC-resonator. By employing sideband drive fields we enhance the
intrinsic coupling strength of about 15 kHz up to 280 kHz by controlling the
amplitude of the drive field. Our results pave the way towards the exploration
of optomechanical effects in a fully superconducting platform and could enable
quantum optics experiments with photons in the yet unexplored radio frequency
band.",1712.03218v1
2017-12-14,Experimental realization of a Rydberg optical Feshbach resonance in a quantum many-body system,"Feshbach resonances in ultra-cold atomic gases have led to some of the most
important advances in atomic physics. They did not only enable ground breaking
work in the BEC-BCS crossover regime [1], but are also widely used for the
association of ultra-cold molecules [2], leading to the formation of molecular
Bose-Einstein condensates [3,4] and ultra-cold dipolar molecular systems [5].
Here, we demonstrate the experimental realization of an optical Feshbach
resonance using ultra-long range Rydberg molecules [6]. We show their practical
use by tuning the revival time of a quantum many-body system quenched into a
deep optical lattice. Our results open up many applications for Rydberg optical
Feshbach resonances as ultra-long range Rydberg molecules have a plenitude of
available resonances for nearly all atomic species. Among the most intriguing
prospects is the engineering of genuine three- and four-body interactions via
coupling to trimer and tetramer molecular states [7].",1712.05263v1
2017-12-20,"Interaction of light with planar lattices of atoms: Reflection, transmission and cooperative magnetometry","We study strong light-mediated resonant dipole-dipole interactions in
two-dimensional planar lattices of cold atoms. We provide a detailed analysis
for the description of the dipolar point emitter lattice plane as a
""super-atom"", whose response is similar to electromagnetically-induced
transparency, but which exhibits an ultra-narrow collective size-dependent
subradiant resonance linewidth. The super-atom model provides intuitively
simple descriptions for the spectral response of the array, including the
complete reflection, full transmission, narrow Fano resonances, and asymptotic
expressions for the resonance linewidths of the collective eigenmodes. We
propose a protocol to transfer almost the entire radiative excitation to a
single correlated subradiant eigenmode in a lattice and show that the medium
obtained by stacked lattice arrays can form a cooperative magnetometer. Such a
magnetometer utilizes similar principles as magnetometers based on the
electromagnetically-induced transparency. The accuracy of the cooperative
magnetometer, however, is not limited by the single-atom resonance linewidth,
but the much narrower collective linewidth that results from the strong
dipole-dipole interactions.",1712.08013v2
2017-12-22,Secondary resonances and the boundary of effective stability of Trojan motions,"One of the most interesting features in the libration domain of co-orbital
motions is the existence of secondary resonances. For some combinations of
physical parameters, these resonances occupy a large fraction of the domain of
stability and rule the dynamics within the stable tadpole region. In this work,
we present an application of a recently introduced `basic Hamiltonian model' Hb
for Trojan dynamics, in Paez and Efthymiopoulos (2015), Paez, Locatelli and
Efthymiopoulos (2016): we show that the inner border of the secondary resonance
of lowermost order, as defined by Hb, provides a good estimation of the region
in phase-space for which the orbits remain regular regardless the orbital
parameters of the system. The computation of this boundary is straightforward
by combining a resonant normal form calculation in conjunction with an
`asymmetric expansion' of the Hamiltonian around the libration points, which
speeds up convergence. Applications to the determination of the effective
stability domain for exoplanetary Trojans (planet-sized objects or asteroids)
which may accompany giant exoplanets are discussed.",1712.08460v1
2017-12-28,Ultrathin wave plates based on bi-resonant silicon Huygens' metasurfaces,"An all-dielectric Huygens metasurface supporting electric and magnetic
resonances is a promising platform for a variety of optical applications that
require a combination of extremely high transmission and broad-range control of
the phase of the transmitted light. A highly efficient wave plate is one
example of such an application. In combination with high spectral selectivity
and strong optical energy concentration, such phase plates are desirable for
precision sensing and high efficiency nonlinear optics. We propose a novel
approach to realizing such ultra-thin optical plates: an anisotropic
Fano-resonant optical metasurface (AFROM) employing the combination of a
spectrally sharp electric and a relatively broadband magnetic resonance. The
phase shift coverage approaching 2{\pi} is achieved through judicious choice of
the geometric parameters of a complex unit cell. A new methodology based on
eigenvalue simulations of leaky magnetic/electric resonances enables rapid
computational design of such metasurfaces.",1712.10064v1
2017-12-29,Resonant pinning spectroscopy with spin-vortex pairs,"Vortex pairs in magnetic nanopillars with strongly coupled cores and pinning
of one of the cores by a morphological defect, are used to perform resonant
pinning spectroscopy, in which a microwave excitation applied to the nanopillar
produces pinning or depinning of the cores only when the excitation is in
resonance with the rotational or gyrational eigenmodes of the specific initial
state of the core-core pair. The shift in the eigenmode frequencies between the
pinned and depinned states is determined experimentally and explained
theoretically, and illustrates the potential for multi-core spin-vortex memory
with resonant writing of information on to various stable vortex pair states.
Further, it is shown how the same resonant spectroscopy techniques applied to a
vortex pair can be used as a sensitive nanoscale probe for characterizing
morphological defects in magnetic films.",1712.10162v2
2017-12-31,Resonance in modulation instability from non-instantaneous nonlinearities,"To explore resonance phenomena in the nonlinear region, we show by
experimental measurements and theoretical analyses that resonance happens in
modulation instability (MI) from non-instantaneous nonlinearities in
photorefractive crystals. With a temporally periodic modulation in the external
bias voltage, corresponding to a modulation in the nonlinear strength, an
enhancement in the visibility of MI at resonant frequency is reported through
spontaneous optical pattern formations. Modeled by such temporally periodic
nonlinear driving force to the system, theoretical curves obtained from a
nonlinear non-instantaneous Schr\""{o}dinger equation give good agreement to
experimental data. As MI is a universal signature of symmetry-breaking
phenomena, our observation on the resonance in MI may provide a control on
chaotic, solitary, and turbulence waves.",1801.00248v1
2018-01-17,Synchronization of electrically coupled resonate-and-fire neurons,"Electrical coupling between neurons is broadly present across brain areas and
is typically assumed to synchronize network activity. However, intrinsic
properties of the coupled cells can complicate this simple picture. Many cell
types with strong electrical coupling have been shown to exhibit resonant
properties, and the subthreshold fluctuations arising from resonance are
transmitted through electrical synapses in addition to action potentials. Using
the theory of weakly coupled oscillators, we explore the effect of both
subthreshold and spike-mediated coupling on synchrony in small networks of
electrically coupled resonate-and-fire neurons, a hybrid neuron model with
linear subthreshold dynamics and discrete post-spike reset. We calculate the
phase response curve using an extension of the adjoint method that accounts for
the discontinuity in the dynamics. We find that both spikes and resonant
subthreshold fluctuations can jointly promote synchronization. The subthreshold
contribution is strongest when the voltage exhibits a significant post-spike
elevation in voltage, or plateau. Additionally, we show that the geometry of
trajectories approaching the spiking threshold causes a ""reset-induced shear""
effect that can oppose synchrony in the presence of network asymmetry, despite
having no effect on the phase-locking of symmetrically coupled pairs.",1801.05874v1
2018-01-19,Three-body recombination near a narrow Feshbach resonance in $^6$Li,"We experimentally measure, and theoretically analyze the three-atom
recombination rate, $L_3$, around a narrow $s$ wave magnetic Feshbach resonance
of $^6$Li-$^6$Li at 543.3 Gauss. By examining both the magnetic field
dependence and especially the temperature dependence of $L_3$ over a wide range
of temperatures from a few $\mu$K to above 200 $\mu$K, we show that three-atom
recombination through a narrow resonance follows a universal behavior
determined by the long-range van der Waals potential, and can be described by a
set of rate equations in which three-body recombination proceeds via successive
pairwise interactions. We expect the underlying physical picture to be
applicable not only to narrow $s$ wave resonances, but also to resonances in
nonzero partial waves, and not only at ultracold temperatures, but also at much
higher temperatures.",1801.06489v1
2017-12-02,On performance of nano-resonators produced by magnetron sputtering deposition,"Magnetron sputtering is a perfect technique for processing nanomaterials for
engineering and medical applications. A material can be processed with specific
mechanical properties, microstructure, and surface texture by controlling the
parameters of magnetron sputtering. Therefore, studies should be conducted on
investigating the processing conditions on the performance of nanomaterials
processed by magnetron sputtering. In this study, effects of the processing
force on performance of micro/nano-resonators produced by magnetron sputtering
are revealed. The processing force is defined as the ratio of the sputtering
power-to-the substrates traveling velocity. By comparing the substrate
traveling velocity to the deposition rate of the sputtered particles, relations
are derived for the thickness and surface texture evolutions with the
processing force. The coefficients of these relations are experimentally
determined for mechanical resonators made of FeNiCr alloy. Then, the variations
of the natural frequencies of these resonators with the processing force of
magnetron sputtering and the deposition rate of the sputtered particles are
depicted. It is demonstrated that special considerations should be given for
the effects of the processing conditions when design mechanical resonators
produced by magnetron sputtering.",1801.06529v1
2018-01-22,Generalized method of images and reflective color generation from ultra-thin multipole resonators,"The multipole expansion has found limited applicability for optical
dielectric resonators in inhomogeneous environment, such as on the surface of
substrates. Here, we generalize the method of images to multipole analysis for
light scattering by dielectric nanoparticles on conductive substrates. We
present examples illustrating the physical insight provided by our method,
including selection rules governing the excitation of the multipoles. We
propose and experimentally demonstrate a new mechanism to generate high
resolution surface color. The dielectric resonators employed are very thin
(less than 50 nm), i.e. similar in thickness to the plasmonic resonators that
are currently being investigated for structural color. The generalized method
of images opens up new prospects for design and analysis of metasurfaces and
optical dielectric resonators.",1801.07074v1
2018-01-29,Radio-frequency capacitive gate-based sensing,"Developing fast, accurate and scalable techniques for quantum state readout
is an active area in semiconductor-based quantum computing. Here, we present
results on dispersive sensing of silicon corner state quantum dots coupled to
lumped-element electrical resonators via the gate. The gate capacitance of the
quantum device is configured in parallel with a superconducting spiral inductor
resulting in resonators with loaded Q-factors in the 400-800 range. For a
resonator operating at 330 MHz, we achieve a charge sensitivity of 7.7
$\mu$e$/\sqrt{\text{Hz}}$ and, when operating at 616 MHz, we get 1.3
$\mu$e$/\sqrt{\text{Hz}}$. We perform a parametric study of the resonator to
reveal its optimal operation points and perform a circuit analysis to determine
the best resonator design. The results place gate-based sensing at par with the
best reported radio-frequency single-electron transistor sensitivities while
providing a fast and compact method for quantum state readout.",1801.09759v1
2018-09-04,Lattice Kerker effect in the hexagonal boron nitride antenna array,"Subwavelength particles with hyperbolic light dispersion in the constituent
medium are a promising alternative to plasmonic, high-refractive-index
dielectric, and semiconductor structures in the practical realization of
nanoscale optical elements. Hexagonal boron nitride (hBN) is a layered van der
Waals material with natural hyperbolic properties and low-loss
phonon-polaritons at the same time. In this work, we consider multipole
excitations and antennas properties of hBN particles with an emphasis on the
periodic arrangement and collective array modes. We analyze excitation of
lattice resonances in the antenna array and effect of resonance shifts and
overlap with other multipoles supported by particles in the lattice. A decrease
of reflectance from the array is achieved with appropriate lattice spacing
(periods) where the electric and magnetic multipoles overlap, and the resonance
oscillations are in phase and comparable in magnitude. We theoretical
demonstrate that generalized Kerker condition is satisfied in this case, and
hBN antennas in the array efficiently scatter light in the predominantly
forward direction resulting in near-zero reflectance. The resonant lattice
Kerker effect with hyperbolic-medium antennas can be applied in developing
metasurfaces based on hBN resonators for mid-infrared photonics.",1809.00777v1
2018-09-07,Feasibility of a resonance-based Planet Nine search,"It has been proposed that mean motion resonances (MMRs) between Planet Nine
and distant objects of the scattered disk might inform the semimajor axis and
instantaneous position of Planet Nine. Within the context of this hypothesis,
the specific distribution of occupied MMRs largely determines the available
constraints. Here we characterize the behavior of scattered Kuiper Belt objects
arising in the presence of an eccentric Planet Nine ($e_9 \in 0.1$, $0.7$),
focusing on relative sizes of populations occupying particular
commensurabilities. Highlighting the challenge of predicting the exact MMR of a
given object, we find that the majority of resonant test particles have period
ratios with Planet Nine other than those of the form $P_9/P=N/1$, $N/2$ $(N \in
\mathbb{Z}^+)$. Taking into account the updated prior distribution of MMRs
outlined in this work, we find that the close spacing of high-order resonances,
as well as chaotic transport, preclude resonance-based Planet Nine constraints
from current observational data.",1809.02594v1
2018-09-09,Three-Body Problem of Bosons nearby a d-wave Resonance,"Motivated by recent experimental progresses, we investigate few-body
properties of interacting spinless bosons nearby a d-wave resonance. Using the
Skorniakov-Ter-Martirosion (STM) equations, we calculate the scattering length
between an atom and a d-wave dimer, and we find that the atom-dimer scattering
length is positive and is much smaller the result from the mean-field
approximation. We also reveal unique properties of the three-body recombination
rate for a degenerate Bose condensate nearby the d-wave resonance. We find that
the total recombination rate is nearly a constant at the quasi-bound side, in
contrast to the behavior of a thermal gas nearby high-partial wave resonance.
We also find that the recombination rate monotonically increases across the
unitary point toward the bound side, which is due to the largely enhanced
coupling between the atom and the d-wave dimer with deeper binding energy. This
monotonic behavior is also qualitatively different from that of a degenerate
gas nearby an s-wave resonance counterpart.",1809.03023v1
2018-09-12,Many-body effects on Landau-level spectra and cyclotron resonance in graphene,"Recently Russell et al. [Phys. Rev. Lett. 120, 047401 (2018)] have reported a
clear signal of many-particle contributions to cyclotron resonance in
high-mobility hBN-encapsulated graphene, observing significant variations of
resonance energies as a function of the filling factor $\nu$ for a series of
interband channels. To elucidate their results, Coulombic contributions to the
Landau-level spectra and cyclotron resonance in graphene are examined with a
possible band gap taken into account and with emphasis on revealing
electron-hole ($eh$) conjugation symmetry underlying such level and resonance
spectra. Theory, based on the single-mode approximation, gives a practically
good account of the experimental data; the data suggest a band gap of ~ 10 meV
and show a profile that apparently reflects $eh$ conjugation symmetry.",1809.04351v1
2018-09-14,Topological Fano Resonances,"The Fano resonance is a widespread wave scattering phenomenon associated with
a peculiar asymmetric and ultra-sharp line shape, which has found applications
in a large variety of prominent optical devices. While its substantial
sensitivity to geometrical and environmental changes makes it the cornerstone
of efficient sensors, it also renders the practical realization of Fano-based
systems extremely challenging. Here, we introduce the concept of topological
Fano resonance, whose ultra-sharp asymmetric line shape is guaranteed by design
and protected against geometrical imperfections, yet remaining sensitive to
external parameters. We report the experimental observation of such resonances
in an acoustic system, and demonstrate their inherent robustness to geometrical
disorder. Such topologically-protected Fano resonances, which can also be found
in microwave, optical and plasmonic systems, open up exciting frontiers for the
generation of various reliable wave-based devices including low-threshold
lasers, perfect absorbers, ultrafast switches or modulators, and highly
accurate interferometers, by circumventing the performance degradations caused
by inadvertent fabrication flaws.",1809.05389v1
2018-09-18,A Model for Scattering with Proliferating Resonances: Many Coupled Square Wells,"We present a multichannel model for elastic interactions, comprised of an
arbitrary number of coupled finite square-well potentials, and derive
semi-analytic solutions for its scattering behavior. Despite the model's
simplicity, it is flexible enough to include many coupled short-ranged
resonances in the vicinity of the collision threshold, as is necessary to
describe ongoing experiments in ultracold molecules and lanthanide atoms. We
also introduce a simple, but physically realistic, statistical ensemble for
parameters in this model. We compute the resulting probability distributions of
nearest-neighbor resonance spacings and analyze them by fitting to the Brody
distribution. We quantify the ability of alternative distribution functions,
for resonance spacing and resonance number variance, to describe the crossover
regime. The analysis demonstrates that the multichannel square-well model with
the chosen ensemble of parameters naturally captures the crossover from
integrable to chaotic scattering as a function of closed channel coupling
strength.",1809.06900v2
2018-09-22,High spectral resolution of GaAs/AlAs phononic cavities by subharmonic resonant pump-probe excitation,"We present here precise measurement of the resonance frequency, lifetime and
shape of confined acoustic modes in the tens of GHz regime in GaAs/AlAs
superlattice planar and micropillar cavities at low temperature ($\sim
20\,\textrm{K}$). The subharmonic resonant pump-probe technique, where the
repetition rate of the pump laser is tuned to a subharmonic of the cavity
resonance to maximize the amplitude of the acoustic resonance, in combination
with a Sagnac interferometer technique for high sensitivity ($\sim 10
\,\textrm{fm}$) to the surface displacement, has been used. The cavity
fundamental mode at $\sim 20\,\textrm{GHz}$ and the higher order cavity
harmonics up to $\sim 180\,\textrm{GHz}$ have been clearly resolved. Mechanical
Q-values up to $2.7 \times 10^4$ have been measured in a planar superlattice,
and direct spatial mapping of confined acoustic modes in a superlattice cavity
micropillar has been demonstrated. The Q-frequency product obtained is $ \sim 5
\times 10^{14}$ demonstrating the suitability of these superlattice cavities
for optomechanical applications.",1809.08478v1
2018-09-19,Thermal conductivity reduction by acoustic Mie resonance in nanoparticles,"We evaluate the impact of acoustic Mie resonance in nanoparticles on the
thermal conductivity of semiconductor and polymer composites. By appropriately
choosing the bulk modulus and density, and selecting the size of the
nanoparticle to align the Mie resonances with the dominant portion of the
thermal conductivity spectrum, we show that large reductions in thermal
conductivity are achievable with dilute concentrations of nanoparticles. In
semiconductor alloys, where the spectral thermal conductivity is known, our
model can explain the steep reductions in thermal conductivity observed
previously. However, the results of our effort to evaluate acoustic Mie
resonance in polymer composites are inconclusive due to uncertainties in the
spectral thermal conductivity. Acoustic Mie resonances can be useful for
maximizing ZT for thermoelectric applications, since a dilute loading of
nanoparticles can reduce thermal conductivity with minimal impact on electrical
conductivity.",1809.08913v1
2018-09-23,Quantum-Mechanical interpretation of Riemann zeta function zeros,"We demonstrate that the Riemann zeta function zeros define the position and
the widths of the resonances of the quantised Artin dynamical system. The Artin
dynamical system is defined on the fundamental region of the modular group on
the Lobachevsky plane. It has a finite volume and an infinite extension in the
vertical direction that correspond to a cusp. In classical regime the geodesic
flow in the fundamental region represents one of the most chaotic dynamical
systems, has mixing of all orders, Lebesgue spectrum and non-zero Kolmogorov
entropy. In quantum-mechanical regime the system can be associated with the
narrow infinitely long waveguide stretched out to infinity along the vertical
axis and a cavity resonator attached to it at the bottom. That suggests a
physical interpretation of the Maass automorphic wave function in the form of
an incoming plane wave of a given energy entering the resonator, bouncing
inside the resonator and scattering to infinity. As the energy of the incoming
wave comes close to the eigenmodes of the cavity a pronounced resonance
behaviour shows up in the scattering amplitude.",1809.09491v1
2018-09-28,Resonance absorption of a broadband laser pulse,"Broad bandwidth, infrared light sources have the potential to revolutionize
inertial confinement fusion (ICF) by suppressing laser-plasma instabilities.
There is, however, a tradeoff: The broad bandwidth precludes high efficiency
conversion to the ultraviolet, where laser-plasma interactions are weaker.
Operation in the infrared could intensify the role of resonance absorption, an
effect long suspected to be the shortcoming of early ICF experiments. Here we
present simulations exploring the effect of bandwidth on resonance absorption.
In the linear regime, bandwidth has little effect on resonance absorption; in
the nonlinear regime, bandwidth suppresses enhanced absorption resulting from
the electromagnetic decay instability. These findings evince that regardless of
bandwidth, an ICF implosion will confront at least linear levels of resonance
absorption.",1810.00073v1
2018-10-01,Arbitrary order exceptional point induced by photonic spin-orbit interaction in coupled resonators,"Many novel properties of non-Hermitian systems are found at or near the
exceptional points-branch points of complex energy surfaces at which
eigenvalues and eigenvectors coalesce. In particular, higher-order exceptional
points can result in optical structures that are ultrasensitive to external
perturbations. Here we show that an arbitrary order exceptional point can be
achieved in a simple system consisting of identical resonators placed near a
waveguide. Unidirectional coupling between any two chiral dipolar states of the
resonators mediated by the waveguide mode leads to the exceptional point, which
is protected by the transverse spin-momentum locking of the guided wave and is
independent of the positions of the resonators. Various analytic response
functions of the resonators at the exceptional points are experimentally
manifested in the microwave regime. The enhancement of sensitivity to external
perturbations near the exceptional point is also numerically and analytically
demonstrated.",1810.00581v2
2018-10-01,Feshbach resonances in $^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ mixtures and refined molecular potentials for the NaK molecule,"We present a detailed study of interspecies Feshbach resonances of the
bosonic $^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ mixture for magnetic fields up to
$750 \, \mathrm{G}$ in various collision channels. A total of fourteen Feshbach
resonances are reported, as well as four zero crossings of the scattering
length and three inelastic two-body loss features. We use the observed magnetic
field locations of the resonant features together with the known data on
$^{23}\mathrm{Na}+$$^{40}\mathrm{K}$ to refine the singlet and triplet ground
state potentials of NaK and achieve a consistent description of Feshbach
resonances for both, the Bose-Bose mixture of
$^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ as well as the Bose-Fermi mixture of
$^{23}\mathrm{Na}+$$^{40}\mathrm{K}$.",1810.00608v2
2018-10-09,Multi Photon Absorption in Gravity Induced Resonant Emission,"Gravity Induced Resonant Emission (gire) has been proposed as the mechanism
of coronal heating; here we are comparing this with Multi photon Ionisation
(mpi) in Laser. We find both are same, except electron damping as a pre-phase
mechanism to initiate mpi in gire. A high intensity laser field used for mpi,
but in gire, this happens at resonance condition when the Larmour radii of the
particles are same. The temporal compression of photons is achieved by grating
devise, but in gire, this is done by field deficit created due to the loss of
electrons at resonance condition and this loss is compensated by photo
electrons emitted during mpi. Fig.1 (a) \& (b) are plots of mpi in Laser and
resonance condition of gire, shows absolute resemblance except the wider range
of frequency spectrum in gire.",1810.08041v1
2018-10-21,Prospects of searching for composite resonances at the LHC and beyond,"Composite Higgs models predict the existence of resonances. We study in
detail the collider phenomenology of both the vector and fermionic resonances,
including the possibility of both of them being light and within the reach of
the LHC. We present current constraints from di-boson, di-lepton resonance
searches and top partner pair searches on a set of simplified benchmark models
based on the minimal coset $SO(5)/SO(4)$, and make projections for the reach of
the HL-LHC. We find that the cascade decay channels for the vector resonances
into top partners, or vice versa, can play an important role in the
phenomenology of the models. We present a conservative estimate for their reach
by using the same-sign di-lepton final states. As a simple extrapolation of our
work, we also present the projected reach at the 27 TeV HE-LHC and a 100 TeV
$pp$ collider.",1810.08954v2
2018-10-26,Quantitative analysis of losses close to a d-wave open-channel Feshbach resonance in Potassium 39,"We study atom losses associated to a previously unreported magnetic Feshbach
resonance in potassium 39. This resonance is peculiar in that it presents
$d$-wave character both in the open and in the closed channels, directly
coupled by the dominant spin-exchange interaction. The losses associated to a
$d$-wave open-channel resonance present specific signatures such as strong
temperature dependance and anisotropic line shapes. The resonance strength and
position depend on the axial projection of the orbital angular momentum of the
system and are extracted from rigorous multichannel calculations. A two-step
model, with an intermediate collision complex being ejected from the trap after
collisions with free atoms, permits to reproduce the observed dependance of the
loss rate as a function of temperature and magnetic field.",1810.11201v1
2018-10-29,Feshbach resonances in potassium Bose-Bose mixtures,"We present a detailed study of the scattering properties of ultracold
mixtures of bosonic potassium atoms. We locate 20 previously unobserved
Feshbach resonances in isotopic 39K-41K mixtures. These are assigned to s-wave
molecular channels by comparison to an asymptotic bound state model and coupled
channels calculations. Additional Feshbach resonances are studied in spin
mixtures of a single potassium isotope, both in 39K and 41K. In particular, we
characterize the parameters of a selected 39K Feshbach resonance by
radio-frequency association of Feshbach molecules. Our results could be
exploited to refine the model potentials for potassium scattering. Furthermore,
these new Feshbach resonances enlarge the range of experiments possible with
degenerate Bose-Bose mixtures.",1810.12453v1
2019-06-03,Explicit spectral gaps for random covers of Riemann surfaces,"We introduce a permutation model for random degree $n$ covers $X_{n}$ of a
non-elementary convex-cocompact hyperbolic surface
$X=\Gamma\backslash\mathbb{H}$. Let $\delta$ be the Hausdorff dimension of the
limit set of $\Gamma$. We say that a resonance of $X_{n}$ is new if it is not a
resonance of $X$, and similarly define new eigenvalues of the Laplacian. We
prove that for any $\epsilon>0$ and $H>0$, with probability tending to $1$ as
$n\to\infty$, there are no new resonances $s=\sigma+it$ of $X_{n}$ with
$\sigma\in[\frac{3}{4}\delta+\epsilon,\delta]$ and $t\in[-H,H]$. This implies
in the case of $\delta>\frac{1}{2}$ that there is an explicit interval where
there are no new eigenvalues of the Laplacian on $X_{n}$. By combining these
results with a deterministic `high frequency' resonance-free strip result, we
obtain the corollary that there is an $\eta=\eta(X)$ such that with probability
$\to1$ as $n\to\infty$, there are no new resonances of $X_{n}$ in the region
$\{\,s\,:\,\mathrm{Re}(s)>\delta-\eta\,\}$.",1906.00658v3
2019-06-05,Storing quantum information in spins and high-sensitivity ESR,"Quantum information, encoded within the states of quantum systems, represents
a novel and rich form of information which has inspired new types of computers
and communications systems. Many diverse electron spin systems have been
studied with a view to storing quantum information, including molecular
radicals, point defects and impurities in inorganic systems, and quantum dots
in semiconductor devices. In these systems, spin coherence times can exceed
seconds, single spins can be addressed through electrical and optical methods,
and new spin systems with advantageous properties continue to be identified.
Spin ensembles strongly coupled to microwave resonators can, in principle, be
used to store the coherent states of single microwave photons, enabling
so-called microwave quantum memories. We discuss key requirements in realising
such memories, including considerations for superconducting resonators whose
frequency can be tuned onto resonance with the spins. Finally, progress towards
microwave quantum memories and other developments in the field of
superconducting quantum devices are being used to push the limits of
sensitivity of inductively-detected electron spin resonance. The
state-of-the-art currently stands at around 65 spins per root-Hz, with
prospects to scale down to even fewer spins.",1906.02092v1
2019-06-11,Topological modes in radiofrequency resonator arrays,"Topological properties of solid states have sparked considerable recent
interest due to their importance in the physics of lattices with a non-trivial
basis and their potential in the design of novel materials. Here we describe an
experimental and an accompanying numerical toolbox to create and analyze
topological states in coupled radiofrequency resonator arrays. The arrays are
coupled harmonic oscillator systems that are very easily constructed, offer a
variety of geometric configurations, and whose eigenfunctions and eigenvalues
are amenable to detailed analysis. These systems offer well defined analogs to
coupled oscillator systems in general in that they are characterized by
resonances whose frequency spectra depend on the individual resonators, the
interactions between them, and the geometric and topological symmetries and
boundary conditions. In particular, we describe an experimental analog of a
small one-dimensional system, with excellent agreement with theory. The
numerical part of the toolbox allows for simulations of larger mesoscopic
systems with a semi-continuous band structure, in which all resonators still
exhibit individual signatures. Systematic parameter variation yields an
astonishing richness of band structures in this simple linear system, allowing
for further explorations into novel phenomena of topological modes.",1906.04815v1
2019-06-14,Calculation of resonance energies from Q-values,"Resonance energies are frequently derived from precisely measured excitation
energies and reaction Q-values. The latter quantities are usually calculated
from atomic instead of nuclear mass differences. This procedure disregards the
energy shift caused by the difference in the total electron binding energies
before and after the interaction. Assuming that the interacting nuclei in a
stellar plasma are fully ionized, this energy shift can have a significant
effect, considering that the resonance energy enters exponentially into the
expression for the narrow-resonance thermonuclear reaction rates. As an
example, the rate of the $^{36}$Ar(p,$\gamma$)$^{37}$K reaction is discussed,
which, at temperatures below 1 GK, depends only on the contributions of a
single resonance and direct capture. In this case, disregarding the energy
shift caused by the total electron binding energy difference erroneously
enhances the rate by $\approx$40\% near temperatures of 70 MK.",1906.06282v1
2019-06-18,Atomic Resonant Single-Mode Squeezed Light from Four-Wave Mixing through Feedforward,"Squeezed states of light have received renewed attention due to their
applicability to quantum-enhanced sensing. To take full advantage of their
reduced noise properties to enhance atomic-based sensors, it is necessary to
generate narrowband near or on atomic resonance single-mode squeezed states of
light. We have previously generated bright two-mode squeezed states of light,
or twin beams, that can be tuned to resonance with the D1 line of $^{87}$Rb
with a non-degenerate four-wave mixing (FWM) process in a double-lambda
configuration in a $^{85}$Rb vapor cell. Here we report on the use of
feedforward to transfer the amplitude quantum correlations present in the twin
beams to a single beam for the generation of single-mode amplitude squeezed
light. With this technique we obtain a single-mode squeezed state with a
squeezing level of $-2.9\pm0.1$ dB when it is tuned off-resonance and a level
of $-2.0\pm 0.1$ dB when it is tuned on resonance with the D1 $F=2$ to $F'=2$
transition of $^{87}$Rb.",1906.07666v1
2019-06-19,The radial density profile of Saturn's A ring,"In this work, we model the radial density profile of the outer A ring of
Saturn observed with Cassini cameras (Tiscareno & Harris 2018): An axisymmetric
diffusion model has been developed, accounting for the outward viscous flow of
the ring material, and the counteracting inward drift caused by resonances of
the planet's large outer moons. It has been generally accepted that the 7:6
resonance of Janus alone confines the outer A ring which, however, was
disproved by Tajeddine et al. (2017). We show that the step-like density
profile of the outer A ring is predominantly defined by the discrete
first-order resonances of Janus, the 5:3 second-order resonance of Mimas, and
the overlapping resonances of Prometheus and Pandora.",1906.08036v1
2019-06-20,Exclusion Limits on Hidden-Photon Dark Matter near 2 neV from a Fixed-Frequency Superconducting Lumped-Element Resonator,"We present the design and performance of a simple fixed-frequency
superconducting lumped-element resonator developed for axion and hidden photon
dark matter detection. A rectangular NbTi inductor was coupled to a Nb-coated
sapphire capacitor and immersed in liquid helium within a superconducting
shield. The resonator was transformer-coupled to a DC SQUID for readout. We
measured a quality factor of $\sim$40,000 at the resonant frequency of 492.027
kHz and set a simple exclusion limit on $\sim$2 neV hidden photons with kinetic
mixing angle $\varepsilon\gtrsim1.5\times10^{-9}$ based on 5.14 hours of
integrated noise. This test device informs the development of the Dark Matter
Radio, a tunable superconducting lumped-element resonator which will search for
axions and hidden photons over the 100 Hz to 300 MHz frequency range.",1906.08814v1
2019-06-23,Super-resonances in microspheres: extreme effects in field localization,"We reveal the existence of optical super-resonance modes supported by
dielectric microspheres. These modes,with field-intensity enhancement factors
on the order of 10^4-10^5, can be directly obtained from analytical
calculations. In contrast to usual optical resonances, which are related to the
poles of the electric and magnetic scattering amplitudes, super-resonance modes
are related to the poles of the internal field coefficients, obtained for
specific values of the size parameter. We also reveal the connection of these
super-resonances in the generation of magnetic nanojets and of giant magnetic
fields in particles with high refractive index.",1906.09636v1
2019-06-28,Ground-state cooling of an magnomechanical resonator induced by magnetic damping,"Quantum manipulation of mechanical resonators has been widely applied in
fundamental physics and quantum information processing. Among them, cooling the
mechanical system to its quantum ground state is regarded as a key step. In
this work, we propose a scheme which one can realize ground-state cooling of
resonator in a cavity magnomechanical system. The system consists of a
microwave cavity and a small ferromagnetic sphere, in which phonon-magnon
coupling and cavity photon-magnon coupling can be achieved via magnetostrictive
interaction and magnetic dipole interaction, respectively. After adiabatically
eliminating the cavity mode, an effective Hamiltonian which consists of magnon
and mechanical modes is obtained. Within experimentally feasible parameters, we
demonstrate that the ground-state cooling of the magnomechanical resonator can
be achieved by extra magnetic damping. Unlike optomechanical cooling,
magnomechanical interaction is utilized to realize the cooling of resonators.
We further illustrate the ground-state cooling can be effectively controlled by
the external magnetic field.",1906.12081v1
2019-06-28,"Passage through a resonance for a mechanical system, having time-varying parameters and possessing a single trapped mode. The principal term of the resonant solution","We consider a forced oscillation and passage through resonance for an
infinite-length system, having time-varying parameters and possessing a single
trapped mode. The system is a string, lying on the Winkler foundation and
equipped with a discrete linear mass-spring oscillator of time-varying
stiffness. We obtain the principal term of the asymptotic expansion for the
resonant solution describing the motion of the inclusion (i.e., the mass-spring
oscillator). The obtained result was verified by independent numerical
calculations based on solution of the corresponding partial differential
equation by means of the method of finite differences. The comparison
demonstrates a good agreement in a neighbourhood of the instant of resonance.",1907.00067v3
2019-07-01,"Detecting the ""phonon wind"" in superfluid $\mathrm{^4He}$ by a nanomechanical resonator","Nanoscale mechanical resonators are widely utilized to provide high
sensitivity force detectors. Here we demonstrate that such high quality factor
resonators immersed in superfluid \(^4\mathrm{He}\) can be excited by a
modulated flux of phonons. A nanosized heater immersed in superfluid
\(^4\mathrm{He}\) acts as a source of ballistic phonons in the liquid --
""phonon wind"". When the modulation frequency of the phonon flux matches the
resonance frequency of the mechanical resonator, the motion of the latter can
be excited. This ballistic thermomechanical effect can potentially open up new
types of experiments in quantum fluids.",1907.01947v1
2019-07-04,Fano resonance lineshapes in a waveguide-microring structure enabled by an air-hole,"We propose and demonstrate, by simply inserting an air-hole in the waveguide
side-coupling with a microring resonator (MRR), the transmission spectrum
presents Fano lineshapes at all of the resonant modes. Measured from the
fabricated devices, Fano lineshapes with slope rates over 400 dB/nm and
extinction ratios over 20 dB are obtained. We ascribe it to the
air-hole-induced phase-shift between the discrete resonant modes of the MRR and
the continuum propagating mode of the bus-waveguide, which modifies their
interference lineshapes from symmetric Lorentzian to asymmetric Fano. From
devices with varied locations and diameters of the air-hole, different Fano
asymmetric parameters are extracted, verifying the air-hole-induced
phase-shifts. This air-hole-assisted waveguide-MRR structure for achieving Fano
resonance lineshapes has advantages of simple design, compact footprint, large
tolerance of fabrication errors, as well as broadband operation range. It has
great potentials to expand and improve performances of on-chip MRR-based
devices, including sensors, switchings and filters.",1907.02186v1
2019-07-04,Resonant properties of composite structures consisting of several resonant diffraction gratings,"We theoretically and numerically investigate resonant optical properties of
composite structures consisting of several subwavelength resonant diffraction
gratings separated by homogeneous layers. Using the scattering matrix
formalism, we demonstrate that the composite structure comprising N gratings
has a multiple transmittance zero of the order N. We show that at the distance
between the gratings satisfying the Fabry-P\'erot resonance condition, an
(N-1)-degenerate bound state in the continuum (BIC) is formed. The results of
rigorous numerical simulations fully confirm the theoretically predicted
formation of multiple zeros and BICs in the composite structures. Near the
BICs, an effect very similar to the electromagnetically induced transparency is
observed. We show that by proper choice of the thicknesses of the layers
separating the gratings, nearly rectangular reflectance or transmittance peaks
with steep slopes and virtually no sidelobes can be obtained. In particular,
one of the presented examples demonstrates the possibility of obtaining an
approximately rectangular transmittance peak having a significantly
subnanometer width. The presented results may find application in the design of
optical filters, sensors and devices for optical differentiation and
transformation of optical signals.",1907.02315v1
2019-07-08,Hyperon I: Partial wave amplitudes for $K^-p$ scattering,"Early data on $K^-$ induced reactions off protons are collected and used in a
coupled-channel partial wave analysis (PWA). Data which had been published in
the form of Legendre coefficients are included in the PWA. In a {\it primary}
fit using 3* and 4* resonances only, we observe some significant discrepancies
with the data. In a systematic search for new $\Lambda$ and $\Sigma$ hyperon
resonances, additional candidates are found. The significance of the known and
of the additional resonances is evaluated. Seventeen resonances listed with 1*
or 2* and one resonance listed with 3* in the Review of Particle Properties
cannot be confirmed, five new hyperons are suggested. The partial-wave
amplitudes deduced in this analysis are compared to those from other analyses.",1907.03645v1
2019-07-09,Studies of the resonance components in the $B_s$ decays into charmonia plus kaon pair,"In this work, the decays of $B_s$ mesons to a charmonium state and a $K^+K^-$
pair are carefully investigated in the perturbative QCD approach. Following the
latest fit from the LHCb experiment, we restrict ourselves to the case where
the produced $K^+K^-$ pair interact in isospin zero $S$, $P$, and $D$ wave
resonances in the kinematically allowed mass window. Besides the dominant
contributions of the $\phi(1020)$ resonance in the $P$-wave and $f_2'(1525)$ in
the $D$-wave, other resonant structures in the high mass region as well as the
$S$-wave components are also included. The invariant mass spectra for most of
the resonances in the $B_s\rightarrow J/\psi K^+K^-$ decay are well reproduced.
The obtained three-body decay branching ratios can reach the order of
$10^{-4}$, which seem to be accessible in the near future experiments. The
associated polarization fractions of those vector-vector and vector-tensor
modes are also predicted, which are compared with the existing data from LHCb
Collaboration.",1907.04128v2
2019-07-17,Synchronization in PT-symmetric optomechanical resonators,"Synchronization has great impacts in various fields such as self-clocking,
communication, neural networks, etc. Here we present a mechanism of
synchronization for two mechanical modes in two coupled optomechanical
resonators by introducing the so-called PT-symmetric structure. It is shown
that the degree of synchronization between the two far-off-resonant mechanical
modes can be increased by decreasing the coupling strength between the two
optomechanical resonators. Additionally, when we consider the stochastic noises
in the optomechanical resonators, we find that more noises can enhance the
degree of synchronization of the system under particular parameter regime. Our
results open up the new dimension of research for PT-symmetric systems and
synchronization.",1907.07415v2
2019-07-22,On the topology of nearly-integrable Hamiltonians at simple resonances,"We show that, in general, averaging at simple resonances a real--analytic,
nearly--integrable Hamiltonian, one obtains a one--dimensional system with a
cosine--like potential; ``in general'' means for a generic class of holomorphic
perturbations and apart from a finite number of simple resonances with small
Fourier modes;
  ``cosine--like'' means that the potential depends only on the resonant angle,
with respect to which it is a Morse function with one maximum and one minimum.
\\ Furthermore, the (full) transformed Hamiltonian is the sum of an effective
one--dimen\-sio\-nal Hamiltonian (which is, in turn, the sum of the unperturbed
Hamiltonian plus the cosine--like potential) and a perturbation, which is
exponentially small with respect to the oscillation of the potential. \\ As a
corollary, under the above hypotheses, if the unperturbed Hamiltonian is also
strictly convex, the effective Hamiltonian at {\sl any simple resonance} (apart
a finite number of low--mode resonances) has the phase portrait of a pendulum.
\\ The results presented in this paper are an essential step in the proof (in
the ``mechanical'' case)
  of a conjecture by Arnold--Kozlov--Neishdadt (\cite[Remark~6.8, p.
285]{AKN}), claiming that the measure of the ``non--torus set'' in general
nearly--integrable Hamiltonian systems has the same
  size of the perturbation; compare \cite{BClin}, \cite{BC}.",1907.09434v1
2019-05-26,Piezo-optomechanical coupling of a 3D microwave resonator to a bulk acoustic wave crystalline resonator,"We report the observation of coupling between a 3D microwave cavity mode and
a bulk mechanical resonator mediated by piezoelectric and radiation pressure
effects. The system is composed of a quartz bulk acoustic wave resonator placed
inside a microwave re-entrant cavity, which is designed to act as both the
electrodes for piezoelectric actuation as well as a 3D resonator. The cavity
electromagnetic mode is modulated by a 5 MHz bulk acoustic wave shear mode,
which is modeled and experimentally verified using the input-output formalism.
Through finite element method simulations, we calculate the various
contributions to the electromechanical coupling and discuss the potential of
the system to reach high cooperativities as well as suitable applications.",1907.10753v2
2019-09-05,Pulsed electron spin resonance spectroscopy in the Purcell regime,"When spin relaxation is governed by spontaneous emission of a photon into the
resonator used for signal detection (the Purcell effect), the relaxation time
$T_1$ depends on the spin-resonator frequency detuning $\delta$ and coupling
constant $g$. We analyze the consequences of this unusual dependence for the
amplitude and temporal shape of a spin-echo in a number of different
experimental situations. When the coupling $g$ is distributed inhomogeneously,
we find that the effective spin-echo relaxation time measured in a saturation
recovery sequence strongly depends on the parameters of the detection echo.
When the spin linewidth is larger than the resonator bandwidth, the Fourier
components of the echo relax with different characteristic times, which implies
that the temporal shape of the echo becomes dependent on the repetition time of
the experiment. We provide experimental evidence of these effects with an
ensemble of donor spins in silicon at millikelvin temperatures measured by a
superconducting micro-resonator.",1909.02443v1
2019-09-15,Blockade-induced resonant enhancement of the optical nonlinearity in a Rydberg medium,"We predict a resonant enhancement of the nonlinear optical response of an
interacting Rydberg gas under conditions of electromagnetically induced
transparency. The enhancement originates from a two-photon process which
resonantly couples electronic states of a pair of atoms dressed by a strong
control field. We calculate the optical response for the three-level system by
explicitly including the dynamics of the intermediate state. We find an
analytical expression for the third order susceptibility for a weak classical
probe field. The nonlinear absorption displays the strongest resonant behavior
on two-photon resonance where the detuning of the probe field equals the Rabi
frequency of the control field. The nonlinear dispersion of the medium exhibits
various spatial shapes depending on the interaction strength. Based on the
developed model, we propose a realistic experimental scenario to observe the
resonance by performing transmission measurements.",1909.06802v1
2019-09-14,Poles of the Scattering Matrix: An Inverse Method for Designing Photonic Resonators,"We develop and implement a new mathematical and computational framework for
designing photonic elements with one or more high-$Q$ scattering resonances.
The approach relies on solving for the poles of the scattering matrix, which
mathematically amounts to minimizing the determinant of the Fredholm integral
operator of the electric field with respect to the permittivity profile of the
scattering element. We apply the method to design subwavelength
gradient-permittivity structures with multiple scattering resonances and
quality factors exceeding 500. We also find the spectral scattering cross
sections are consistent with Fano lineshapes. The compact form and
computational efficiency of our formalism suggest it can be a useful tool for
designing Fano-resonant structures with multiple high-$Q$ resonances for
applications such as frequency mixing and conversion.",1909.07798v1
2019-09-18,Gain-through-filtering enables tuneable frequency comb generation in passive optical resonators,"Optical frequency combs (OFCs), consisting of a set of phase locked equally
spaced laser frequency lines, have enabled a great leap in precision
spectroscopy and metrology since seminal works of H\""ansch et al. . Nowadays,
OFCs are cornerstones of a wealth of further applications ranging from
chemistry and biology to astrophysics and including molecular fingerprinting
and LIDARs among others. Driven passive optical resonators constitute the ideal
platform for OFCs generation in terms of compactness and low energy footprint.
We propose here a new technique for generation of OFCs with tuneable repetition
rate in externally driven optical resonators based on the
gain-through-filtering process, a simple and elegant method, due to an
asymmetric spectral filtering on one side of the pump wave. We demonstrate a
proof-of-concept experimental result in a fibre resonator, pioneering a new
technique that does not require specific engineering of the resonator
dispersion to generate frequency agile OFCs.",1909.08294v2
2019-09-25,Delay-Induced Resonance in the Time-Delayed Duffing Oscillator,"The phenomenon of delay-induced resonance implies that in a nonlinear system
a time-delay term may be used as an effective enhancer of the oscillations
caused by an external forcing maintaining the same frequency. This is possible
for the parameters for which the time-delay induces sustained oscillations.
Here, we study this type of resonance in the overdamped and underdamped
time-delayed Duffing oscillators, and we explore some new features. One of them
is the conjugate phenomenon: the oscillations caused by the time-delay may be
enhanced by means of the forcing without modifying their frequency. The
resonance takes place when the frequency of the oscillations induced by the
time-delay matches the ones caused by the forcing and vice versa. This is an
interesting result as the nature of both perturbations is different. Even for
the parameters for which the time-delay does not induce sustained oscillations,
we show that a resonance may appear following a different mechanism.",1909.11357v1
2019-09-26,$\mathbfβ$-delayed proton emission from $\mathbf{^{11}}$Be in effective field theory,"We calculate the rate of the rare decay $^{11}\text{Be}$ into $^{10}\text{Be}
+ p +e^- + \bar{\nu}_e$ using Halo effective field theory, thereby describing
the process of beta-delayed proton emission. We assume a shallow $1/2^+$
resonance in the $^{10}\text{Be}-p$ system with an energy consistent with a
recent experiment by Ayyad et al. and obtain $b_p =
4.9_{-2.9}^{+5.6}\text{(exp.)}_{-0.8}^{+4.0}\text{(theo.)} \times 10^{-6}$ for
the branching ratio of this decay, predicting a resonance width of $\Gamma_R =
(9.0^{+4.8}_{-3.3}\text{(exp.)}^{+5.3}_{-2.2}\text{(theo.)})~\text{keV}$. Our
calculation shows that the experimental branching ratio and resonance
parameters of Ayyad et al. are consistent with each other. Moreover, we analyze
the general impact of a resonance on the branching ratio and demonstrate that a
wide range of combinations of resonance energies and widths can reproduce
branching ratios of the correct order. Thus, no exotic mechanism (such as
beyond the standard model physics) is needed to explain the experimental decay
rate.",1909.12206v3
2019-09-26,Polar metamaterials: A new outlook on resonance for cloaking applications,"Rotationally resonant metamaterials are leveraged to answer a longstanding
question regarding the existence of transformation-invariant elastic materials
and the ad-hoc possibility of transformationbased passive cloaking in full
plane elastodynamics. Combined with tailored lattice geometries, rotational
resonance is found to induce a polar and chiral behavior; that is a behavior
lacking stress and mirror symmetries, respectively. The central, and simple,
idea is that a population of rotating resonators can exert a density of body
torques strong enough to modify the balance of angular momentum on which hang
these symmetries. The obtained polar metamaterials are used as building blocks
of a cloaking device. Numerical tests show satisfactory cloaking performance
under pressure and shear probing waves, further coupled through a free
boundary. The work sheds new light on the phenomenon of resonance in
metamaterials and should help put transformation elastodynamics on equal
footing with transformation acoustics and optics.",1909.12437v1
2019-10-01,Atoms in separated resonators can jointly absorb a single photon,"The coherent nonlinear process where a single photon simultaneously excites
two or more two-level systems (qubits) in a single-mode resonator has recently
been theoretically predicted. Here we explore the case where the two qubits are
placed in different resonators in an array of two or three weakly coupled
resonators. Investigating different setups and excitation schemes, we show that
this process can still occur with a probability approaching one under specific
conditions. The obtained results provide interesting insights into subtle
causality issues underlying the simultaneous excitation processes of qubits
placed in different resonators.",1910.00224v3
2019-10-04,Effective theories and resonances in strongly-coupled electroweak symmetry breaking scenarios,"Due to the mass gap between the Standard Model and possible New Physics
states, electroweak effective approaches are appropriate. Although a linear
realization of the electroweak symmetry breaking with the Higgs forming a
doublet together with the Goldstone bosons of the EWSB is a first possibility
(SMEFT), we adopt the more general non-linear realization, where the Higgs is a
singlet with independent couplings (EWET, HEFT or EWChL). We present the
effective Lagrangian at low energies (the EWET, with only the SM fields) and at
high energies (the resonance theory, with also a set of resonances). Taking
into account the high scale of these resonances, their experimental searches
seem to be more accessible by considering their imprints at low-energies, i.e.,
their imprints in the Low Energy Constants (LECs) of the EWET at energies lower
than the resonance masses. We give some examples of these phenomenological
connections.",1910.01839v1
2019-10-06,Pomeron-pomeron scattering,"Central exclusive diffractive (CED) production of meson resonances
potentially is a factory producing new particles, in particular a glueball. The
produced resonances lie in trajectories with vacuum quantum numbers,
essentially on the pomeron trajectory. A tower of resonance recurrences, the
production cross section and the resonances widths are predicted. A new feature
is the form of the non-linear pomeron trajectory, producing resonances
(glueballs) with increasing widths. At LHC energies, in the nearly forward
direction the $t$-channel both in elastic, single or double diffraction
dissociation as well as in CED is dominated by pomeron exchange (the role of
secondary trajectories is negligible, however a small contribution from the
odderon may be present).",1910.02503v2
2019-10-10,Magnetic Octupole Response of Dielectric Oligomers,"The development of new approaches to tuning the resonant magnetic response of
simple all-dielectric nanostructures is very important in modern nanophotonics.
Here we show that a resonant magnetic octupole (MOCT) response can be obtained
by dividing a solid rectangular silicon block to an oligomer structure with the
introduction of narrow gaps between four nanocubes. We control and tune the
spectral position of the MOCT resonance by varying the distance between the
nanocubes. We demonstrate that several magnetic hot-spots related to the MOCT
resonance can be located in the gaps creating a strong magnetic field gradient
in free space. We observe that the resonant excitation of the MOCT moment leads
to a significant enhancement of light absorption in the system at the spectral
region, where light absorption in bulk silicon is weak. The results of this
work can be applied to design new composite antennas and metamaterials based on
complex building blocks, energy harvesting devices and molecular trapping with
magnetic hot-spots.",1910.04538v1
2019-10-11,Controlling Thermal Emission by Parity-symmetric Fano Resonance of Optical Absorbers in Metasurfaces,"In this study, we designed a metasurface based on Al/SiN/Al nano-sandwich
optical absorbers. Parity-symmetric dark magnetic resonance modes,
anti-symmetric bright magnetic resonance modes, and surface lattice modes are
established simultaneously in such a meta-surface. By changing the structural
parameters, the wavelength of the dark mode can be tuned to overlap with the
lattice mode. Fano resonance is introduced by coupling between the dark and
lattice modes. Angular-resolved thermal emission experiments showed that the
thermal emission induced by Fano resonance exhibited a narrow wavelength
spectrum and directional radiation angle. Fano-type thermal emitters proposed
in this work can possibly be used as coherent infrared light sources in the
future.",1910.04933v1
2019-10-14,A Movable Valley Switch Driven by Berry Phase in Bilayer Graphene Resonators,"Since its discovery, Berry phase has been demonstrated to play an important
role in many quantum systems. In gapped Bernal bilayer graphene, the Berry
phase can be continuously tuned from zero to 2pi, which offers a unique
opportunity to explore the tunable Berry phase on the physical phenomena. Here,
we report experimental observation of Berry phases-induced valley splitting and
crossing in moveable bilayer graphene p-n junction resonators. In our
experiment, the bilayer graphene resonators are generated by combining the
electric field of scanning tunneling microscope tip with the gap of bilayer
graphene. A perpendicular magnetic field changes the Berry phase of the
confined bound states in the resonators from zero to 2pi continuously and leads
to the Berry phase difference for the two inequivalent valleys in the bilayer
graphene. As a consequence, we observe giant valley splitting and unusual
valley crossing of the lowest bound states. Our results indicate that the
bilayer graphene resonators can be used to manipulate the valley degree of
freedom in valleytronics.",1910.05873v1
2019-10-16,Searching for scalar dark matter with compact mechanical resonators,"We explore the viability of laboratory-scale mechanical resonators as
detectors for ultralight scalar dark matter. The signal we investigate is an
atomic strain due to modulation of the fine structure constant and the lepton
mass at the Compton frequency of dark matter particles. The resulting stress
can drive an elastic body with acoustic breathing modes, producing
displacements that are accessible with opto- or electromechanical readout
techniques. To address the unknown mass of dark matter particles (which
determines their Compton frequency), we consider various resonator designs
operating at kHz to MHz frequencies, corresponding to $10^{-12}-10^{-5}$ eV
particle mass. Current resonant-mass gravitational wave detectors that have
been repurposed as dark matter detectors weigh $\sim \! 10^3$ kg. We find that
a large unexplored parameter space can be accessed with ultra-high-$Q$,
cryogenically-cooled, cm-scale mechanical resonators possessing $\sim \! 10^7$
times smaller mass.",1910.07574v2
2019-10-17,Resonant Energization of Relativistic particles by an Intense Electromagnetic Wave,"The phenomenon of resonant energization of a relativistic quantum particle,
moving in unison with an intense ElectroMagnetic Wave, is demonstrated in a
semiclassical calculation. The wave nature of the quantum particle is of
essence because the resonant process originates in wave-wave
interaction-between the classical EM wave, and the quantum wave associated with
the particle. When the energy /momentum of the quantum wave satisfy the
resonance condition (the effective phase speeds of the two waves are equal),
the particle, drawing energy directly from the intense EM field, could acquire
extremely high energies Such a direct resonant energy transfer from intense
Electromagnetic waves will constitute a hitherto unexploited mechanism that
could power the most energetic of cosmic rays. Some predictions of the theory
will, hopefully, be tested in the laboratory Laser experiments.",1910.08147v1
2019-10-21,Microwave limiters implemented by coupled dielectric resonators based on a topological defect mode and CT-symmetry breaking,"We present a microwave realization of a reflective topological limiter based
on an explicit self-induced violation of a charge-conjugation (CT) symmetry.
The starting point is a bipartite structure created by coupled dielectric
resonators with a topological defect placed at the center and two lossy
resonators placed on the neighboring sites of the defect. This defect supports
a resonant mode if the CT-symmetry is present, while it is suppressed once the
symmetry is violated due to permittivity changes of the defect resonator
associated with high irradiances of the incident radiation. This destruction
leads to a suppression of transmittance and a subsequent increase of the
reflectance while the absorption is also suppressed.",1910.09203v1
2019-10-28,Design of a loop-gap resonator with bimodal uniform fields using finite element analysis,"The loop-gap resonator (LGR) was originally developed to provide a uniform
microwave magnetic field on a sample for electron spin resonance (ESR)
experiments. The LGR is composed of one or more loops and gaps acting as
inductances and capacitances respectively. Typical LGR designs produce a
uniform field on a sample at a single resonant frequency, but for certain
experiments it is necessary to study the response of a material to uniform
fields at multiple frequencies applied simultaneously. In this work we develop
an empirical design procedure using finite element method calculations to
design an asymmetric loop-gap resonator with uniform fields at two frequencies
in the same sample volume and analyze the field uniformity, frequency
tunability and filling factors, providing comparison to a manufactured device.",1910.12479v1
2019-10-30,Resonance study of SU(2) model with 2 fundamental flavours of fermions,"Composite Higgs models are promising candidate models to address the
long-standing naturalness problem in the Standard Model. Among them, the most
minimal one is the SU(2) with 2 flavours of fermions in the fundamental
representation of the gauge group. An important prediction in these models is
the existence of resonance spectrum in vector boson scattering. Here we study
the lowest such resonance, which is the equivalent of rho resonance in QCD. We
describe the scan of the parameter space using the clover-improved Wilson
fermions with Symanzik improved gauge action and then show the first results
for the mass and width of the rho resonance in this model.",1910.13847v1
2020-01-14,Experimental realization of optimal energy storage in resonators embedded in scattering media,"The ability to enhance light-matter interactions by increasing the energy
stored in optical resonators is inherently dependent on their coupling to the
incident wavefront. In practice, weak coupling may result from resonators'
irregular shapes and/or the scrambling of waves in the surrounding scattering
environment. Here, we present a non-invasive wavefront shaping technique
providing optimal coupling to resonators. The coherent control of the incident
wavefront relies on the lengthening of delay times of waves efficiently
exciting the resonator. We demonstrate our concept in microwave experiments by
injecting in-situ optimal wavefronts that maximize the energy stored in
multiple high-permittivity dielectric scatterers and extended leaky cavities
embedded in a complex environment. We expect our framework to find important
applications in the enhancement of light-matter interactions in photonic
materials as well as to enhance energy harvesting.",2001.04658v1
2020-01-15,Surface waves from flexural and compressional resonances of beams,"We present a three-dimensional model describing the propagation of elastic
waves in a soil substrate supporting an array of cylindrical beams experiencing
flexural and compressional resonances. The resulting surface waves are of two
types. In the sagittal plane, hybridized Rayleigh waves can propagate except
within bandgaps resulting from a complex interplay between flexural and
compressional resonances. We exhibit a wave decoupled from the hybridized
Rayleigh wave which is the elastic analogue of electromagnetic spoof plasmon
polaritons. This wave with displacements perpendicular to the sagittal plane is
sensitive only to flexural resonances. Similar, yet quantitatively different,
physics is demonstrated in a two-dimensional setting involving resonances of
plates.",2001.06304v1
2020-01-23,"Fano-Resonant, Asymmetric, Metamaterial-Assisted Tweezers for Single Nanoparticle Trapping","Plasmonic nanostructures can overcome Abbe's diffraction limit to generate
strong gradient fields, enabling efficient optical trapping of nano-sized
particles. However, it remains challenging to achieve stable trapping with low
incident laser intensity. Here, we demonstrate a Fano resonance-assisted
plasmonic optical tweezers (FAPOT), for single nanoparticle trapping in an
array of asymmetrical split nano-apertures, milled on a 50 nm gold thin film.
Stable trapping is achieved by tuning the trapping wavelength and varying the
incident trapping laser intensity. A very large normalized trap stiffness of
8.65 fN/nm/mW for 20 nm polystyrene particles at a near-resonance trapping
wavelength of 930 nm was achieved. We show that trap stiffness on resonance is
enhanced by a factor of 63 compared to off-resonance conditions. This can be
attributed to the ultra-small mode volume, which enables large near-field
strengths and a cavity Purcell effect contribution. These results should
facilitate strong trapping with low incident trapping laser intensity, thereby
providing new options for studying transition paths of single molecules, such
as proteins, DNA, or viruses.",2001.08319v1
2020-01-24,Suppressed-gap millimetre wave kinetic inductance detectors using DC-bias current,"In this study, we evaluate the suitability of using DC-biased aluminium
resonators as low-frequency kinetic inductance detectors operating in the
frequency range of 50 - 120 GHz. Our analysis routine for supercurrent-biased
resonators is based on the Usadel equations and gives outputs including density
of states, complex conductivities, transmission line properties, and
quasiparticle lifetimes. Results from our analysis confirm previous
experimental observations on resonant frequency tuneability and retention of
high quality factor. Crucially, our analysis suggests that DC-biased resonators
demonstrate significantly suppressed superconducting density of states gap.
Consequently these resonators have lower frequency detection threshold and are
suitable materials for low-frequency kinetic inductance detectors.",2001.09089v2
2020-01-28,Enhancement of deep-subwavelength band gaps in flat spiral-based phononic metasurfaces using the trampoline phenomena,"Elastic and acoustic metamaterials can sculpt dispersion of waves through
resonances. In turn, resonances can give rise to negative effective properties,
usually localized around the resonance frequencies, which support band gaps at
subwavelength frequencies (i.e., below the Bragg-scattering limit). However,
the band gaps width correlates strongly with the resonators' mass and volume,
which limits their functionality in applications. Trampoline phenomena have
been numerically and experimentally shown to broaden the operational frequency
ranges of two-dimensional, pillar-based metamaterials through perforation. In
this work, we demonstrate trampoline phenomena in lightweight and planar
lattices consisting of arrays of Archimedean spirals in unit cells.
Spiral-based metamaterials have been shown to support different band gap
opening mechanisms, namely, Bragg-scattering, local resonances and inertia
amplification. Here, we numerically analyze and experimentally realize
trampoline phenomena in planar metasurfaces for different lattice
tessellations. Finally, we carry out a comparative study between trampoline
pillars and spirals and show that trampoline spirals outperform the pillars in
lightweight, compactness and operational bandwidth.",2001.10508v1
2020-01-30,Feshbach spectroscopy of an ultracold $^{41}$K-$^6$Li mixture and $^{41}$K atoms,"We have observed 69 $^{41}$K-$^6$Li interspecies Feshbach resonances
including 13 elastic p-wave resonances and 6 broad d-wave resonances of
$^{41}$K atoms in different spin-state combinations at fields up to 600~G.
Multi-channel quantum defect theory calculation is performed to assign these
resonances and the results show perfect agreement with experimental values
after improving input parameters. The observed broad p- and d- wave resonances
display a full resolved multiplet structure. They may serve as important
simulators to nonzero partial wave dominated physics.",2001.11203v1
2020-01-31,A mathematical and numerical framework for gradient meta-surfaces built upon periodically repeating arrays of Helmholtz resonators,"In this paper a mathematical model is given for the scattering of an incident
wave from a surface covered with microscopic small Helmholtz resonators, which
are cavities with small openings. More precisely, the surface is built upon a
finite number of Helmholtz resonators in a unit cell and that unit cell is
repeated periodically. To solve the scattering problem, the mathematical
framework elaborated in [Ammari et al., Asympt. Anal., 2019] is used. The main
result is an approximate formula for the scattered wave in terms of the lengths
of the openings. Our framework provides analytic expressions for the scattering
wave vector and angle and the phase-shift. It justifies the apparent
absorption. Moreover, it shows that at specific lengths for the openings and a
specific frequency there is an abrupt shift of the phase of the scattered wave
due to the subwavelength resonances of the Helmholtz resonators. A numerically
fast implementation is given to identify a region of those specific values of
the openings and the frequencies.",2001.11587v1
2020-02-02,Virtual Critical Coupling,"Electromagnetic resonators are a versatile platform to harvest, filter and
trap electromagnetic energy, at the basis of many applications from microwaves
to optics. Resonators with a large intrinsic quality factor (Q) are highly
desirable since they can store a large amount of energy, leading to sharp
filtering and low loss. Exciting high-Q cavities with monochromatic signals,
however, suffers from poor excitation efficiency, i.e., most of the impinging
energy is lost in the form of reflection, since high-Q resonators are weakly
coupled to external radiation. Although critical coupling eliminates
reflections in steady-state by matching the intrinsic and coupling decay rates,
this approach requires the introduction of loss in the resonator, causing
dissipation and lowering the overall Q-factor. Here, we extend the notion of
critical coupling to high-Q lossless resonators based on tailoring the temporal
profile of the excitation wave. Utilizing coupled-mode theory, we demonstrate
an effect analogous to critical coupling by mimicking loss with
non-monochromatic excitations at complex frequencies. Remarkably, we show that
this approach enables unitary excitation efficiency in open systems, even in
the limit of extreme quality factors in the regime of quasi-bound states in the
continuum.",2002.00487v1
2020-02-11,Revisiting the Possible 4f7 5d1 Ground State of Gd Impurities in SmB6 by Electron Spin Resonance,"The search for topological states in strongly correlated electron systems has
renewed the interest in the Kondo insulator SmB6. One of the most intriguing
previous results was an anomalous electron spin resonance spectrum in Gd-doped
SmB6. This spectrum was attributed to Gd2+ ions because it could be very well
decribed by a model considering a change in the valence from Gd3+ to Gd2+, a
dynamic Jahn-Teller effect and a 4f7 5d1 ground state in the Hamiltonian. In
our work, we have revisited this scenario using electron spin resonance and
energy dispersive X-ray spectroscopy measurements. Our results suggest that the
resonance is produced by Gd2+ ions; however the resonance stems from an
extrinsic oxide impurity phase that lies on the surface of the crystal.",2002.04572v1
2020-02-11,Resonant scattering of Dice quasiparticles on oscillating quantum dots,"We consider a Dice model with Dirac cones intersected by a topologically flat
band at the charge neutrality point and analyze the inelastic scattering of
massless pseudospin-1 particles on a circular, gate-defined, oscillating
barrier. Focusing on the resonant scattering regime at small energy of the
incident wave, we calculate the reflection and transmission coefficients and
derive explicit expressions for the time-dependent particle probability,
current density and scattering efficiency within (Floquet) Dirac-Weyl theory,
both in the near-field and the far-field. We discuss the importance of sideband
scattering and Fano resonances in the quantum limit. When resonance conditions
are fulfilled, the particle is temporarily trapped in vortices located close to
edge of the quantum dot before it gets resubmitted with strong angular
dependence. Interestingly even periodically alternating forward and backward
radiation may occur. We also demonstrate the revival of resonant scattering
related to specific fusiform boundary trapping profiles.",2002.04659v1
2020-02-24,Photothermally Induced Transparency,"Induced transparency is a common but remarkable effect in optics. It occurs
when a strong driving field is used to render an otherwise opaque material
transparent. The effect is known as electromagnetically induced transparency in
atomic media and optomechanically induced transparency in systems that consist
of coupled optical and mechanical resonators. In this work, we introduce the
concept of photothermally induced transparency (PTIT). It happens when an
optical resonator exhibits non-linear behavior due to optical heating of the
resonator or its mirrors. Similar to the established mechanisms for induced
transparency, PTIT can suppress the coupling between an optical resonator and a
traveling optical field. We further show that the dispersion of the resonator
can be modified to exhibit slow or fast light. Because of the relatively slow
thermal response, we observe the bandwidth of the PTIT to be $2\pi\times15.9$
Hz which theoretically suggests a group velocity of as low as $5$ m/s.",2002.10041v1
2020-02-25,Determining the nature of quantum resonances by probing elastic and reactive scattering in cold collisions,"Scattering resonances play a central role in collision processes in physics
and chemistry. They help building an intuitive understanding of the collision
dynamics due to the spatial localization of the scattering wavefunctions. For
resonances that are localized in the reaction region, located at short
separation behind the centrifugal barrier, sharp peaks in the reaction rates
are the characteristic signature, observed recently with state-of-the-art
experiments in low energy collisions. If, however, the localization occurs
outside of the reaction region, mostly the elastic scattering is modified. This
may occur due to above barrier resonances, the quantum analogue of classical
orbiting. By probing both elastic and inelastic scattering of metastable helium
with deuterium molecules in merged beam experiments, we differentiate between
the nature of quantum resonances -- tunneling vs above barrier -- and
corroborate our findings by calculating the corresponding scattering
wavefunctions.",2002.10750v2
2020-02-25,Landau-Zener-Stückelberg Interferometry in dissipative Circuit Quantum Electrodynamics,"We study Landau-Zener-St\""uckelberg (LZS) interferometry in a cQED
architecture under effects of dissipation. To be specific, we consider a
superconducting qubit driven by a dc+ac signal and coupled to a transmission
line resonator, but our results are valid for general qubit-resonators devices.
To take the environment into account, we assume that the resonator is coupled
to an ohmic quantum bath. The Floquet-Born-Markov master equation is
numerically solved to obtain the dynamics of the system for arbitrary amplitude
of the drive and different time scales. We unveil important differences in the
resonant patterns between the Strong Coupling and Ultra Strong Coupling regimes
in the qubit-resonator interaction, which are mainly due to the magnitude of
photonic gaps in the energy spectrum of the system. We identify in the LZS
patterns the contribution of the qubit gap and the photonic gaps, showing that
for large driving amplitudes the patterns present a weaving structure due to
the combined intercrossing of the different gaps contributions.",2002.10827v1
2020-04-05,Multiphoton resonance and chiral transport in the generalized Rabi model,"The generalized Rabi model (gRM) with both one- and two-photon coupling terms
has been successfully implemented in circuit quantum electrodynamics systems.
In this paper, we examine theoretically multiphoton resonances in the gRM and
derive their effective Hamiltonians. With different detunings in the system, we
show that all three- to six-photon resonances can be achieved by involving two
intermediate states. Furthermore, we study the interplay between multiphoton
resonance and chiral transport of photon Fock states in a resonator junction
with broken time-reversal symmetry. Depending on the qubit-photon interaction
and photon-hopping amplitude, we find that the system can demonstrate different
short-time dynamics.",2004.02283v2
2020-04-06,Elastic $α$-$^{12}$C scattering at low energies with the sharp resonant $0_3^+$ state of $^{16}$O,"An inclusion of sharp resonant $0_3^+$ state of $^{16}$O and first excited
$2_1^+$ state of $^{12}$C in a study of $s$-wave elastic $\alpha$-$^{12}$C
scattering at low energies is investigated in an effective Lagrangian approach.
The elastic scattering amplitude is parted into two; one is for the sharp
resonant $0_3^+$ state of $^{16}$O parameterized by Breit-Wigner formula, and
the other is for a non-resonant part of the amplitude parameterized by
effective range expansion. In the non-resonant part of the amplitude, a
contribution from the $2_1^+$ state of $^{12}$C is included. We discuss a large
correlation between a coupling for the $2_1^+$ state of $^{12}$C and an
effective range parameter $Q_0$ as well as a necessity of inclusion of a vertex
correction for the initial and final $\alpha$-$^{12}$C states. After fixing
parameters appearing in the amplitudes by using experimental data, we calculate
asymptotic normalization coefficients for ground $0_1^+$ state and first
excited $0_2^+$ state of $^{16}$O and compare them to previous results found in
literature.",2004.02361v2
2020-04-06,Influence of nuclear motion on resonant two-center photoionization,"Photoionization of an atom in the presence of a neighboring atom of different
species is studied. The latter first undergoes resonant photoexcitation,
leading to an autoionizing state of the diatomic system. Afterwards, the
excitation energy is transferred radiationlessly via a two-center Auger process
to the other atom, causing its ionization. Assuming a fixed internuclear
distance, it has been predicted theoretically that this indirect ionization
pathway can strongly dominate over the direct photoionization. Here, we extend
the theory of resonant two-center photoionization by including the nuclear
motion in van-der-Waals molecules. An analytical formula is derived reflecting
the influence of molecular vibrational dynamics on the relative strength of the
two-center channel. For the specific example of Li-He dimers we show that the
two-center autoionizing resonances are split by the nuclear motion into
multiplets, with the resonance lines reaching a comparable level of enhancement
over direct photoionization as is obtained in a model based on spatially fixed
nuclei.",2004.02459v2
2020-04-07,Horizontal Line Nodes in Sr2RuO4 Proved by Spin Resonance,"We investigated the low-energy incommensurate (IC) magnetic fluctuations in
Sr$_2$RuO$_4$ by the high-resolution inelastic neutron scattering measurements
and random phase approximation (RPA) calculations. We observed a spin resonance
with energy of $\hbar\omega_\text{res}=0.56$~meV centered at a characteristic
wavevector $\mathbf{Q}_\text{res}=(0.3, 0.3, 0.5)$. The resonance energy
corresponds well to the superconducting gap $2\Delta=0.56$~meV estimated by the
tunneling spectroscopy. The spin resonance shows the $L$ modulation with a
maximum at around $L = 0.5$. The $L$ modulated intensity of the spin resonance
and our RPA calculations indicate that the superconducting gaps regarding the
quasi-one-dimensional $\alpha$ and $\beta$ sheets at the Fermi surfaces have
the horizontal line nodes. These results may set a strong constraint on the
pairing symmetry of Sr$_2$RuO$_4$. We also discuss the implications on possible
superconducting order parameters.",2004.03591v1
2020-04-17,Ramsey-biased spectroscopy of superconducting qubits under dispersion,"We proposed a spectroscopic method that extends Ramsey's atomic spectroscopy
to detect the transition frequency of a qubit fabricated on a superconducting
circuit. The method uses a multi-interval train of qubit biases to implement an
alternate resonant and dispersive couplings to an incident probe field. The
consequent absorption spectrum of the qubit has a narrower linewidth at its
transition frequency than that obtained from constantly biasing the qubit to
resonance while the middle dispersive evolution incurs only a negligible shift
in detected frequency. Modeling on transmon qubits, we find that the linewidth
reduction reaches 23% and Ramsey fringes are simultaneously suppressed at
extreme duration ratio of dispersion over resonance for a double-resonance
scheme. If the scheme is augmented by an extra resonance segment, a further 37%
reduction can be achieved.",2004.08188v1
2020-04-21,Tunable Polarization-Induced Fano Resonances in Stacked Wire-Grid Metasurfaces,"Stacked metasurfaces are being investigated in light of exploring exotic
optical effects that cannot be achieved with single-layered metasurfaces. In
this Letter, we theoretically demonstrate that stacks of metallic wire-grid
metasurfaces possessing specific polarization properties have the ability to
induce tunable Fano resonances. The developed original model - combining a
circulating field approach together with an extended Jones formalism - reveals
the underlying principle that gives rise to the polarization-induced Fano
resonances. The theoretical frame is validated in an experimental proof of
concept using commercially available wire-grids and a terahertz time domain
spectrometer. This unexplored possibility opens an alternative path to the
realization and control of Fano resonances by using stacked metallic
metasurfaces. Furthermore, these findings suggest that the polarization can be
used as an additional degree of freedom for the design of optical resonators
with enhanced and tunable properties.",2004.10295v1
2020-12-08,Magnetic field resilient high kinetic inductance superconducting niobium nitride coplanar waveguide resonators,"We characterize niobium nitride (NbN) $\lambda/2$ coplanar waveguide
resonators, which were fabricated from a 10nm thick film on silicon dioxide
grown by sputter deposition. For films grown at 120{\deg}C we report a
superconducting critical temperature of 7.4K associated with a normal square
resistance of 1k$\Omega$ leading to a kinetic inductance of 192pH/$\Box$. We
fabricated resonators with a characteristic impedance up to 4.1k$\Omega$ and
internal quality factors $Q_\mathrm{i} > 10^4$ in the single photon regime at
zero magnetic field. Moreover, in the many photons regime, the resonators
present high magnetic field resilience with $Q_\mathrm{i} > 10^4$ in a 6T
in-plane magnetic field as well as in a 300mT out-of-plane magnetic field.
These findings make such resonators a compelling choice for cQED experiments
involving quantum systems with small electric dipole moments operated in finite
magnetic fields.",2012.04366v2
2020-12-14,Interplay between the factorization of the Jarlskog Invariant and location of the Solar and Atmospheric Resonances for Neutrino Oscillations in Matter,"The Jarlskog invariant which controls the size of intrinsic CP violation in
neutrino oscillation appearance experiments is modified by Wolfenstein matter
effects for neutrinos propagating in matter. In this paper we give the exact
factorization of Jarlskog invariant in matter into the vacuum Jarlskog
invariant times two, two-flavor matter resonance factors that control the
matter effects for the solar and atmospheric resonances independently. We
compare the location of the minima of the factorizing resonance factors with
the location of the solar and atmospheric resonances, precisely defined. They
are not identical but the fractional differences are both found to be less than
0.1\%. In addition, we explain why symmetry polynomials of the square of the
mass of the neutrino eigenvalues in matter, such as inverse of the square of
the Jarlskog invariant in matter, can be given as polynomials in the matter
potential.",2012.07186v2
2020-12-14,Controllable Optical Resonances and Unidirectional Scattering by Core-shell Nanoparticles,"Nanoparticles supporting a distinct series of Mie resonances have enabled a
new class of nanoantennas and provide efficient ways to manipulate light at the
nanoscale. The ability to flexibly tune the optical resonances and scattering
directionality are particularly essential for various applications ranging from
biosensing to nanolasers. In this paper, we investigate the core-shell
nanoparticles that support both electric and magnetic Mie resonances and for
the first time systematically reveal the mode evolution from a pure high-index
dielectric nanosphere to a pure plasmonic one, where it has a sudden transition
when core-shell ratio increases from 0.4 to 0.5. Furthermore, by engineering
the electric and magnetic resonances, we demonstrate the unidirectional forward
and backward scattering in such a system and reveal its tunability via
geometric tuning.",2012.07355v2
2020-11-11,Effects of modal energy scattering and friction on the resonance mitigation with an impact absorber,"A linear vibration absorber can be tuned to effectively suppress the
resonance of a particular vibration mode. It relies on the targeted energy
transfer into the absorber within a narrow and fixed frequency band. Nonlinear
energy sinks (NES) have a similar working principle. They are effective in a
much wider frequency band but generally only in a limited range of excitation
levels. To design NES, their working principle must be thoroughly understood.
We consider a particular type of NES, a small mass undergoing impacts and dry
friction within a cavity of a base structure (vibro-impact NES or impact
absorber). The nonlinear dynamic regimes under near-resonant forcing and
resulting operating ranges are first revisited. We then investigate how
off-resonant vibration modes and dissipation via impacts and dry friction
contribute to the vibration suppression. Moreover, we assess the effectiveness
of the impact absorber for suppressing multiple resonances in comparison to a
linear tuned vibration absorber (LTVA) and a pure friction damper with the same
mass.",2012.07539v1
2020-12-17,Kerr-like nonlinearities in an optomechanical system with an asymmetric anharmonic mechanical resonator,"In the framework of the nonsecular perturbation theory based on the
Bogoliubov averaging method, an optomechanical system with an asymmetric
anharmonic mechanical resonator is studied. The cross-Kerr interaction and the
Kerr-like self-interaction of photons and vibration quanta arise in the
Hamiltonian. These interactions are induced by both cubic and quartic
nonlinearities of oscillations of the mechanical resonator and the
cavity-resonator interaction that is linear in mechanical displacements. We
demonstrate a bistable behavior of the number of vibration quanta and find that
this behavior is controlled by the cross-Kerr interaction. It is shown that,
without driving and dissipation, the constructed superposition
Yurke-Stoler-like states of the cavity (or the mechanical resonator)
disentangle at certain times the entangled modes of the system. The obtained
results offer new possibilities for control of optomechanical systems with
asymmetric mechanical oscillations.",2012.09671v2
2020-12-18,Stabilization method with Relativistic Configuration-interaction applied to two-electron resonances,"We applied a relativistic configuration-interaction (CI) framework to the
stabilization method as an approach for obtaining the autoionization resonance
structure of heliumlike ions. In this method, the ion is confined within an
impenetrable spherical cavity, the size of which determines the radial space
available for electron wavefunctions and electron-electron interactions. By
varying the size of the cavity, one can obtain the autoionization resonance
position and width. The applicability of this method is tested on the
resonances of He atom while comparing with benchmark data available in the
literature. The present method is further applied to the determination of the
resonance structure of heliumlike uranium ion, where a relativistic framework
is mandatory. In the strong-confinement region, the present method can be
useful to simulate the properties of an atom or ion under extreme pressure. An
exemplary application of the present method to determine the structure of ions
embedded in a dense plasma environment is briefly discussed.",2012.10382v1
2020-12-20,Three-body universality in ultracold $p$-wave resonant mixtures,"We study three-body collisions within ultracold mixtures with resonant
interspecies $p$-wave interactions. Our results for the three-body effective
interaction strength and decay rate are crucial towards understanding the
stability and lifetime of these dilute quantum fluids. On resonance, we find
that a class of universal scattering pathways emerges, regardless of the
details of the short-range interactions. This gives rise quite generally to a
remarkable regime where three-body effective interactions dominate over both
inelastic decay and two-body effective interactions. Additionally, we find a
series of mass-ratio-dependent trimer resonances further from resonance.",2012.10887v2
2020-12-21,Radiation instability of a relativistic electron beam into a split-cavity resonator,"The radiation instability in a split-cavity asymmetric resonator is
considered for the relativistic case. The space charge of an electron beam is
taken into account. In the small-signal approximation, the energy loss by
particles passing through the resonator and the modulation of beam current are
investigated. Based on analytical and numerical calculations, it is shown that
the symmetric configuration of a split-cavity resonator provides the highest
rate of instability growth. It is shown that the beam modulation and the
efficiency of energy transfer from particles to electromagnetic field decrease
with the increase in the initial electron energy. The increase in beam density
has a positive effect on the radiation instability growth. It is important to
take into account the obtained results when developing generators of
electromagnetic radiation and systems for modulating the beam current based on
a split-cavity resonator.",2012.11297v1
2020-12-23,Dielectric perturbations: anomalous resonance frequency shifts in optical resonators,"Small perturbations in the dielectric environment around a high quality
whispering gallery mode resonator usually lead to a frequency shift of the
resonator modes directly proportional to the polarizability of the
perturbation. Here, we report experimental observations of strong frequency
shifts that can be opposite and even exceed the contribution of the
perturbations' polarizability. The mode frequencies of a lithium niobate
whispering gallery mode resonator are shifted using substrates of refractive
indices ranging from 1.50 to 4.22. Both blue- and red-shifts are observed, as
well as an increase in mode linewidth, when substrates are moved into the
evanescent field of the whispering gallery mode. We compare the experimental
results to a theoretical model by Foreman et al. and provide an additional
intuitive explanation based on the Goos-H\""anchen shift for the optical domain.",2012.12446v1
2021-01-03,The effect of flow on resonant absorption of slow MHD waves in magnetic flux tubes,"In this paper, we study kink and sausage oscillations in the presence of
longitudinal background flow. We study resonant absorption of the kink and
sausage modes in the slow continuum under magnetic pore conditions in the
presence of flow. we determine the dispersion relation then solve it
numerically, and find the frequencies and damping rates of the slow kink and
sausage surface modes. We also, obtain analytical solution for the damping rate
of the slow surface mode in the long wavelength limit. We show that in the
presence of plasma flow, resonance absorption can result in strong damping for
forward waves and can be considered as an efficient mechanism to justify the
extremely rapid damping of slow surface sausage waves observed in magnetic
pores. Also, the plasma flow reduces the efficiency of resonance absorption to
damp backward waves. Furthermore, for the pore conditions, the resonance
instability is avoided in our model.",2101.02064v1
2021-01-15,Multioscillating black holes,"We study rotating global AdS solutions in five-dimensional Einstein gravity
coupled to a multiplet complex scalar within a cohomogeneity-1 ansatz. The
onset of the gravitational and scalar field superradiant instabilities of the
Myers-Perry-AdS black hole mark bifurcation points to black resonators and
hairy Myers-Perry-AdS black holes, respectively. These solutions are subject to
the other (gravitational or scalar) instability, and result in hairy black
resonators which contain both gravitational and scalar hair. The hairy black
resonators have smooth zero-horizon limits that we call graviboson stars. In
the hairy black resonator and graviboson solutions, multiple scalar components
with different frequencies are excited, and hence these are multioscillating
solutions. The phase structure of the solutions are examined in the
microcanonical ensemble, i.e. at fixed energy and angular momenta. It is found
that the entropy of the hairy black resonator is never the largest among them.
We also find that hairy black holes with higher scalar wavenumbers are
entropically dominant and occupy more of phase space than those of lower
wavenumbers.",2101.06325v1
2021-01-29,Energies and widths of Efimov states in the three-boson continuum,"Three-boson Efimov physics is well known in the bound-state regime, but far
less in the three-particle continuum at negative two-particle scattering length
where Efimov states evolve into resonances. They are studied solving rigorous
three-particle scattering equations for transition operators in the momentum
space. The dependence of the three-boson resonance energy and width on the
two-boson scattering length is studied with several force models. The universal
limit is determined numerically considering highly excited states; simple
parametrizations for the resonance energy and width in terms of the scattering
length are established. Decreasing the attraction, the resonances rise not much
above the threshold but broaden rapidly and become physically unobservable,
evolving into subthreshold resonances. Finite-range effects are studied and
related to those in the bound-state regime.",2101.12654v1
2012-05-14,Dressed-state amplification by a superconducting qubit,"We demonstrate amplification of a microwave signal by a strongly driven
two-level system in a coplanar waveguide resonator. The effect known from
optics as dressed-state lasing is observed with a single quantum system formed
by a persistent current (flux) qubit. The transmission through the resonator is
enhanced when the Rabi frequency of the driven qubit is tuned into resonance
with one of the resonator modes. Amplification as well as linewidth narrowing
of a weak probe signal has been observed. The laser emission at the resonator's
fundamental mode has been studied by measuring the emission spectrum. We
analyzed our system and found an excellent agreement between the experimental
results and the theoretical predictions obtained in the dressed-state model.",1205.3017v1
2012-05-14,Etch Induced Microwave Losses in Titanium Nitride Superconducting Resonators,"We have investigated the correlation between the microwave loss and
patterning method for coplanar waveguide titanium nitride resonators fabricated
on Si wafers. Three different methods were investigated: fluorine- and
chlorine-based reactive ion etches and an argon-ion mill. At high microwave
probe powers the reactive etched resonators showed low internal loss, whereas
the ion-milled samples showed dramatically higher loss. At single-photon powers
we found that the fluorine-etched resonators exhibited substantially lower loss
than the chlorine-etched ones. We interpret the results by use of numerically
calculated filling factors and find that the silicon surface exhibits a higher
loss when chlorine-etched than when fluorine-etched. We also find from
microscopy that re-deposition of silicon onto the photoresist and side walls is
the probable cause for the high loss observed for the ion-milled resonators",1205.3153v1
2017-05-02,On-chip quantum interference with heralded photons from two independent micro-ring resonator sources in silicon photonics,"High visibility on-chip quantum interference among indistinguishable
single-photons from multiples sources is a key prerequisite for integrated
linear optical quantum computing. Resonant enhancement in micro-ring resonators
naturally enables brighter, purer and more indistinguishable single-photon
production without any tight spectral filtering. The indistinguishability of
heralded single-photons from multiple micro-ring resonators has not been
measured in any photonic platform. Here, we report on-chip indistinguishability
measurements of heralded single-photons generated from independent micro-ring
resonators by using an on-chip Mach-Zehnder interferometer and spectral
demultiplexer. We measured the raw heralded two-photon interference fringe
visibility as 72 +/- 3%. This result agrees with our model, which includes
device imperfections, spectral impurity and multi-pair emissions. We identify
multi-pair emissions as the main factor limiting the nonclassical interference
visibility, and show a route towards achieving near unity visibility in future
experiments.",1705.01029v2
2017-05-14,Squeezed cooling of mechanical motion beyond the resolved-sideband limit,"Cavity optomechanics provides a unique platform for controlling
micromechanical systems by means of optical fields that crosses the
classical-quantum boundary to achieve solid foundations for quantum
technologies. Currently, optomechanical resonators have become promising
candidates for the development of precisely controlled nano-motors,
ultrasensitive sensors and robust quantum information processors. For all these
applications, a crucial requirement is to cool the mechanical resonators down
to their quantum ground states. In this paper, we present a novel cooling
scheme to further cool a micromechanical resonator via the noise squeezing
effect. One quadrature in such a resonator can be squeezed to induce enhanced
fluctuation in the other, ""heated"" quadrature, which can then be used to cool
the mechanical motion via conventional optomechanical coupling. Our theoretical
analysis and numerical calculations demonstrate that this squeeze-and-cool
mechanism offers a quick technique for deeply cooling a macroscopic mechanical
resonator to an unprecedented temperature region below the zero-point
fluctuations.",1705.04936v3
2017-05-20,Tuning Feshbach resonance in cold atomic gases with inter-channel coupling,"We show that the essential properties of a Feshbach resonance in cold atomic
gases can be tuned by dressing the atomic states in different scattering
channels through inter-channel couplings. Such a scheme can be readily
implemented in the orbital Feshbach resonance of alkaline-earth-like atoms by
coupling hyperfine states in the clock-state manifolds. Using $^{173}$Yb atoms
as an example, we find that both the resonance position and the two-body
bound-state energy depend sensitively on the inter-channel coupling strength,
which offers control parameters in tuning the inter-atomic interactions. We
also demonstrate the dramatic impact of the dressed Feshbach resonance on
many-body processes such as the polaron to molecule transition and the BCS-BEC
crossover.",1705.07367v2
2017-05-14,Intermolecular Interactions in Radial-Contour Mode Microring Resonators,"This research is on the dynamics of electrostatically actuated radial-contour
mode microring resonators. The governing equation of motion is derived by the
minimization of the Hamiltonian and generalized to include the viscous damping
effect. The Galerkin method is used to discretize the distributed-parameter
model of the considered ring resonator. The influences of intermolecular forces
such as van der Waals and Casimir on the dynamic behavior of the resonator are
investigated. The natural frequencies and mode shapes of the ring are
calculated for various values of ratio of radii (\b{eta}). The effect of the
design parameters including ring radius, electrostatic voltage and quality
factor on the dynamic responses, is discussed. The results of present study can
be used in the design of novel MEMS resonators, RF filters and channelizers.",1705.07710v1
2017-09-04,A novel approach to the synthesis of the electromagnetic field distribution in a chain of coupled resonators,"A novel approach to the synthesis of the electromagnetic field distribution
in a chain of coupled resonators has been developed. This approach is based on
the new matrix form of the solutions of the second-order difference equations.
If a chain of coupled resonators can be described by the second-order
difference equation for amplitudes of expansion of the electromagnetic field,
two linearly independent solutions can be constructed on the basis of the
solutions of nonlinear Riccaty equation. Setting the structure of one solution,
from the Riccaty equation we can find the electrodynamical characteristics of
resonators and coupling holes, at which the desired distribution of amplitudes
is realized. On the base of this approach we considered the problem of
separation of the electromagnetic field into forward and backward components in
the inhomogeneous chain of resonators. It was shown that in the frame of
considered model such separation is not defined uniquely.",1709.00842v1
2017-09-12,Details of Resonant Structures Within a Nice Model Kuiper Belt: Predictions for High-Perihelion TNO Detections,"We analyze a detailed Nice model simulation of Kuiper Belt emplacement from
Brasser & Morbidelli (2013), where Neptune undergoes a high eccentricity phase
and migrates outward. In this work, which follows from Pike et al. (2017), we
specifically focus on the details of structures within Neptune's mean motion
resonances and in the high pericenter population of simulated trans-Neptunian
Objects (TNOs). We find several characteristics of these populations which
should be observable in the distant Solar System in future large-scale TNO
surveys as a diagnostic of whether or not this mode of Neptune migration
occurred in the early Solar System. We find that the leading asymmetric
libration islands of the $n$:1 resonances are generally much more populated
than the trailing islands. We also find the non-resonant high-$q$ population of
TNOs should have higher inclinations than the low-$q$ population due to the
importance of Kozai cycling during their emplacement histories. Finally,
high-$q$ TNOs should be present in roughly equal numbers on either side of
distant mean-motion resonances. These predictions contrast with predictions
from other Kuiper Belt emplacement simulations, and will be testable by
upcoming surveys.",1709.03699v1
2017-09-18,Interference between two resonant transitions with distinct initial and final states connected by radiative decay,"The resonant line shape from driving a transition between two states,
$|\rm{a}\rangle$ and $|\rm{b}\rangle$, can be distorted due to a
quantum-mechanical interference effect involving a resonance between two
different states, $|\rm{c}\rangle$ and $|\rm{d}\rangle$, if $|\rm{c}\rangle$
has a decay path to $|\rm{a}\rangle$ and $|\rm{d}\rangle$ has a decay path to
$|\rm{b}\rangle$. This interference can cause a shift of the measured
resonance, despite the fact that the two resonances do not have a common
initial or final state. As an example, we demonstrate that such a shift affects
measurements of the atomic hydrogen 2S$_{1/2}$-to-2P$_{1/2}$ Lamb-shift
transition due to 3S-to-3P transitions if the 3S$_{1/2}$ state has some initial
population.",1709.05913v1
2017-09-21,Limitations of rotating-wave approximation in magnetic resonance: Characterization and elimination of the Bloch-Siegert shift in magneto-optics,"We present investigations of radio-frequency resonances observed in a
rubidium vapor. With measurements of a systematic shift of radio-frequency
resonances, induced by an off-resonance component of an oscillating field (the
Bloch-Siegert shift), we demonstrate limitations of the rotating-wave
approximation. Experimental results are supported with numerical calculations,
reproducing all features of the observed signals. Based on the studies, we
develop experimental scheme free from the problem. By liberating the
measurements from a systematic error (the resonance shift), the new approach
will increase accuracy of spectroscopic measurements and magnetic-field
detection.",1709.07194v3
2017-09-11,Cylindrical vector resonant modes achieved in planar photonic crystal cavities with enlarged air-holes,"We reveal a triangular-lattice planar photonic crystal supports Bloch modes
with radially and azimuthally symmetric electric field distributions at the top
band-edge of the first photonic band. Bifurcated from the corresponding Bloch
modes, two cylindrical vector resonant modes are achieved by simply enlarging
the central air-hole of the planar photonic crystal, which have high quality
factors around 3,000 and small mode volume. The far-field radiations of the two
resonant modes present high-quality cylindrical vector beam profiles. The
resonant modes could be optimized by modifying the six nearest neighboring
air-holes around the central defect. The cylindrically symmetric
characteristics of the resonant mode's near- and far-fields might provide a new
view to investigate light-matter interactions and device developments in planar
photonic crystal cavities.",1709.07917v1
2017-09-25,Field expansions for systems of strongly coupled plasmonic nanoparticles,"This paper is concerned with efficient representations and approximations of
the solution to the scattering problem by a system of strongly coupled
plasmonic particles. Three schemes are developed: the first is the resonant
expansion which uses the resonant modes of the system of particles computed by
a conformal transformation, the second is the hybridized resonant expansion
which uses linear combinations of the resonant modes for each of the particles
in the system as a basis to represent the solution, and the last one is the
multipole expansion with respect to the origin. By considering a system formed
by two plasmonic particles of circular shape, we demonstrate the relations
between these expansion schemes and their advantages and disadvantages both
analytically and numerically. In particular, we emphasize the efficiency of the
resonant expansion scheme in approximating the near field of the system of
particles. The difference between these plasmonic particle systems and the
nonresonant dielectric particle system is also highlighted. The paper provides
a guidance on the challenges for numerical simulations of strongly coupled
plasmonic systems.",1709.08469v1
2017-09-26,"Observation of ""broad"" d-wave Feshbach resonances with a triplet structure","High partial-wave ($l\ge2$) Feshbach resonance (FR) in an ultracold mixture
of $^{85}$Rb-$^{87}$Rb atoms is investigated experimentally aided by a
partial-wave insensitive analytic multichannel quantum-defect theory (MQDT).
Two ""broad"" resonances from coupling between d-waves in both the open and
closed channels are observed and characterized. One of them shows a fully
resolved triplet structure with splitting ratio well explained by the
perturbation to the closed channel due to interatomic spin-spin interaction.
These tunable ""broad"" d-wave resonances, especially the one in the
lowest-energy open channel, could find important applications in simulating
d-wave coupling dominated many-body systems. In addition, we find that there is
generally a time and temperature requirement, associated with tunneling through
the angular momentum barrier, to establish and observe resonant coupling in
nonzero partial waves.",1709.08794v2
2017-08-14,Giant THz surface plasmon polariton induced by high-index dielectric metasurface,"We use computational approaches to explore the role of a
high-refractive-index dielectric TiO2 grating with deep subwavelength thickness
on InSb as a tunable coupler for THz surface plasmons. We find a series of
resonances as the grating couples a normally-incident THz wave to standing
surface plasmon waves on both thin and thick InSb layers. In a marked contrast
with previously-explored metallic gratings, we observe the emergence of a much
stronger additional resonance. The mechanism of this giant plasmonic resonance
is well interpreted by the dispersion of surface plasmon excited in the
air\TiO2\InSb trilayer system. We demonstrate that both the frequency and the
intensity of the giant resonance can be tuned by varying dielectric grating
parameters, providing more flexible tunability than metallic gratings. The
phase and amplitude of the normally-incident THz wave are spatially modulated
by the dielectric grating to optimize the surface plasmon excitation. The giant
surface plasmon resonance gives rise to strong enhancement of the electric
field above the grating structure, which can be useful in sensing and
spectroscopy applications.",1709.08812v1
2017-09-28,Analysis and mitigation of interface losses in trenched superconducting coplanar waveguide resonators,"Improving the performance of superconducting qubits and resonators generally
results from a combination of materials and fabrication process improvements
and design modifications that reduce device sensitivity to residual losses. One
instance of this approach is to use trenching into the device substrate in
combination with superconductors and dielectrics with low intrinsic losses to
improve quality factors and coherence times. Here we demonstrate titanium
nitride coplanar waveguide resonators with mean quality factors exceeding two
million and controlled trenching reaching 2.2 $\mu$m into the silicon
substrate. Additionally, we measure sets of resonators with a range of sizes
and trench depths and compare these results with finite-element simulations to
demonstrate quantitative agreement with a model of interface dielectric loss.
We then apply this analysis to determine the extent to which trenching can
improve resonator performance.",1709.10015v1
2017-09-29,"Charge-exchange dipole excitations in neutron-rich nuclei: $-1 \hbar ω_0$, anti-analog pygmy, and anti-analog giant resonances","The occurrence of the low-lying charge-exchange non spin-flip dipole modes
below the giant resonance in neutron-rich nuclei is predicted on the basis of
nuclear density functional theory. The ground and excited states are described
in the framework of the self-consistent Hartree-Fock-Bogoliubov and the
proton-neutron quasiparticle-random-phase approximation employing a Skyrme-type
energy density functional. The model calculations are performed for the
spherical neutron-rich Ca, Ni, and Sn isotopes. It is found that the low-lying
states appear sensitively to the shell structure associated with the $-1 \hbar
\omega_0$ excitation below the Gamow-Teller states. Furthermore, the pygmy
resonance emerges below the giant resonance when the neutrons occupy the
low-$\ell (\ell \leq 2 -3)$ orbitals analogous to the pygmy resonance seen in
the electric dipole response.",1709.10272v1
2017-11-07,Probing the hadronic phase with resonances of different lifetimes in Pb-Pb collisions with ALICE,"The ALICE experiment has measured the production of a rich set of hadronic
resonances, such as $\rho(770)^{0}$, ${\rm K}^{\ast}(892)^{0}$, $\phi$(1020),
$\Sigma^{\pm}$(1385), $\Lambda(1520)$ and $\Xi^{\ast 0}$ in pp, p-Pb and Pb-Pb
collisions at various energies at the LHC. A comprehensive overview and the
latest results are presented in this paper. Special focus is given to the role
of hadronic resonances for the study of final-state effects in high-energy
collisions. In particular, the measurement of resonance production in heavy-ion
collisions has the capability to provide insight into the existence of a
prolonged hadronic phase after hadronisation. The observation of the
suppression of the production of $\Lambda(1520)$ resonance in central Pb-Pb
collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV adds further support to the
existence of such a dense hadronic phase, as already evidenced by the ratios
${\rm K}^{\ast}(892)^{0}$/${\rm K}$ and $\rho(770)^{0}$/$\pi$.",1711.02408v1
2017-11-15,Probing Split-Ring Resonator Permeabilities with Loop-Gap Resonators,"A method is proposed to experimentally determine the effective complex
permeability of split-ring resonator (SRR) arrays used in the design of
metamaterials at microwave frequencies. We analyze the microwave response of a
loop-gap resonator (LGR) whose bore has been partially loaded with one or more
SRRs. Our analysis reveals that the resonance frequency, magnetic plasma
frequency, and damping constant of the effective permeability of the SRR array
can be extracted from fits to the reflection coefficient (S11) of an
inductively-coupled LGR. We propose LGR designs that would allow both a
one-dimensional array of SRRs and small three-dimensional arrays of SRRs to be
characterized. Finally, we demonstrate the method using a toroidal LGR loaded
with a single extended SRR of length z.",1711.05819v1
2017-11-17,Resonance frequency broadening of wave-particle interaction in tokamaks due to Alfvénic eigenmode,"We use a guiding center code ORBIT to study the broadening of resonances and
the parametric dependence of the resonance frequency broadening width
$\Delta\Omega$ on the nonlinear particle trapping frequency $\omega_b$ of
wave-particle interaction with specific examples using realistic equilibrium
DIII-D shot 159243 (Collins et al. 2016 Phys. Rev. Lett. 116 095001). When the
mode amplitude is small, the pendulum approximation for energetic particle
dynamics near the resonance is found to be applicable and the ratio of the
resonance frequency width to the deeply trapped bounce frequency
$\Delta\Omega/\omega_b$ equals 4, as predicted by theory. This factor 4 is
demonstrated for the first time in realistic instability conditions. It is
found that as the mode amplitude increases, the coefficient
$a=\Delta\Omega/\omega_b$ becomes increasingly smaller because of the breaking
down of the nonlinear pendulum approximation for the wave-particle interaction.",1711.06574v1
2017-11-23,Graphene multi-mode parametric oscillators,"In the field of nanomechanics, parametric excitations are of interest since
they can greatly enhance sensing capabilities and eliminate cross-talk.
However, parametric excitations often rely on externally tuned springs, which
limits their application to high quality factor resonators and usually does not
allow excitation of multiple higher modes into parametric resonance. Here we
demonstrate parametric amplification and resonance of suspended single-layer
graphene membranes by an efficient opto-thermal drive that modulates the
intrinsic spring constant. With a large amplitude of the optical drive, a
record number of 14 mechanical modes can be brought into parametric resonance
by modulating a single parameter: the pretension. In contrast to conventional
mechanical resonators, it is shown that graphene membranes demonstrate an
interesting combination of both strong nonlinear stiffness and nonlinear
damping.",1711.08798v1
2018-03-17,Two-color electromagnetically induced transparency via modulated coupling between a mechanical resonator and a qubit,"We discuss level splitting and sideband transitions induced by a modulated
coupling between a superconducting quantum circuit and a nanomechanical
resonator. First, we show how to achieve an unconventional time-dependent
longitudinal coupling between a flux (transmon) qubit and the resonator.
Considering a sinusoidal modulation of the coupling strength, we find that a
first-order sideband transition can be split into two. Moreover, under the
driving of a red-detuned field, we discuss the optical response of the qubit
for a resonant probe field. We show that level splitting induced by modulating
this longitudinal coupling can enable two-color electromagnetically induced
transparency (EIT), in addition to single-color EIT. In contrast to standard
predictions of two-color EIT in atomic systems, we apply here only a single
drive (control) field. The monochromatic modulation of the coupling strength is
equivalent to employing two eigenfrequency-tunable mechanical resonators. Both
drive-probe detuning for single-color EIT and the distance between transparent
windows for two-color EIT, can be adjusted by tuning the modulation frequency
of the coupling.",1803.06513v2
2018-03-23,A Novel Approach to Resonant Absorption of the Fast MHD Eigenmodes of a Coronal Arcade,"The arched field lines forming coronal arcades are often observed to undulate
as magnetohydrodynamic (MHD) waves propagate both across and along the magnetic
field. These waves are most likely a combination of resonantly coupled fast
magnetoacoustic waves and Alfv\'en waves. The coupling results in resonant
absorption of the fast waves, converting fast wave energy into Alfv\'en waves.
The fast eigenmodes of the arcade have proven difficult to compute or derive
analytically, largely because of the mathematical complexity that the coupling
introduces. When a traditional spectral decomposition is employed, the discrete
spectrum associated with the fast eigenmodes is often subsumed into the
continuous Alfv\'en spectrum. Thus fast eigenmodes, become collective modes or
quasi-modes. Here we present a spectral decomposition that treats the
eigenmodes as having real frequencies but complex wavenumbers. Using this
procedure we derive dispersion relations, spatial damping rates, and
eigenfunctions for the resonant, fast eigenmodes of the arcade. We demonstrate
that resonant absorption introduces a fast mode that would not exist otherwise.
This new mode is heavily damped by resonant absorption, only travelling a few
wavelengths before losing most of its energy.",1803.08948v1
2018-03-28,Tunable phonon blockade in weakly nonlinear coupled mechanical resonators via Coulomb interaction,"Realizing quantum mechanical behavior in micro- and nanomechanical resonators
has attracted continuous research effort. One of the ways for observing quantum
nature of mechanical objects is via the mechanism of phonon blockade. Here, we
show that phonon blockade could be achieved in a system of two weakly nonlinear
mechanical resonators coupled by a Coulomb interaction. The optimal blockade
arises as a result of the destructive quantum interference between paths
leading to two-phonon excitation. It is observed that, in comparison to a
single drive applied on one mechanical resonator, driving both the resonators
can be beneficial in many aspects; such as, in terms of the temperature
sensitivity of phonon blockade and also with regard to the tunability, by
controlling the amplitude and the phase of the second drive externally. We also
show that via a radiation pressure induced coupling in an optomechanical
cavity, phonon correlations can be measured indirectly in terms of photon
correlations of the cavity mode.",1803.10403v1
2018-03-28,Dysprosium dipolar Bose-Einstein condensate with broad Feshbach resonances,"We produce Bose-Einstein condensates of $^{162}$Dy atoms employing an
innovative technique based on a resonator-enhanced optical trap that allows
efficient loading from the magneto-optical trap and fast evaporation. We
characterize the scattering properties of the ultracold atoms for magnetic
fields between 6 and 30 G. In addition to the typical chaotic distribution of
narrow Feshbach resonances in Lanthanides, we discover two rather isolated
broad features at around 22 G and 27 G. A characterization using the
complementary measurements of losses, thermalization, anisotropic expansion and
molecular binding energy points towards resonances of predominant s-wave
character. Such resonances will ease the investigation of quantum phenomena
relying on the interplay between dipole and contact interactions.",1803.10676v2
2018-06-08,Coupled-Mode Theory for Stationary and Nonstationary Resonant Sound Propagation,"We present a complete analytical derivation of the equations used for
stationary and nonstationary wave systems regarding resonant sound transmission
and reflection described by the phenomenological Coupled-Mode Theory. We
calculate the propagating and coupling parameters used in Coupled-Mode Theory
directly by utilizing the generalized eigenwave-eigenvalue problem from the
Hamiltonian of the sound wave equations. This Hamiltonian formalization can be
very useful since it has the ability to describe mathematically a broad range
of acoustic wave phenomena. We demonstrate how to use this theory as a basis
for perturbative analysis of more complex resonant scattering scenarios. In
particular, we also form the effective Hamiltonian and coupled-mode parameters
for the study of sound resonators with background moving media. Finally, we
provide a comparison between Coupled-Mode theory and full-wave numerical
examples, which validate the Hamiltonian approach as a relevant model to
compute the scattering characteristics of waves by complex resonant systems.",1806.02971v1
2018-06-11,Ab-initio wave-length dependent Raman spectra: Placzek approximation and beyond,"We analyze how to obtain non-resonant and resonant Raman spectra within the
Placzek as well as the Albrecht approximation. Both approximations are derived
from the matrix element for light scattering by application of the Kramers,
Heisenberg and Dirac formula. It is shown that the Placzek expression results
from a semi-classical approximation of the combined electronic and vibrational
transition energies. Molecular hydrogen, water and butadiene are studied as
test cases. It turns out that the Placzek approximation agrees qualitatively
with the more accurate Albrecht formulation even in the resonant regime for the
excitations of single vibrational quanta. However, multiple vibrational
excitations are absent in Placzek, but can be of similar intensities as single
excitations under resonance conditions. The Albrecht approximation takes
multiple vibrational excitations into account and the resulting simulated
spectra exhibit good agreement with experimental Raman spectra in the resonance
region as well.",1806.03840v2
2018-06-18,Marginally bound resonances of charged massive scalar fields in the background of a charged reflecting shell,"We study {\it analytically} the characteristic resonance spectrum of charged
massive scalar fields linearly coupled to a spherically symmetric charged
reflecting shell. In particular, we use analytical techniques in order to solve
the Klein-Gordon wave equation for the composed
charged-shell-charged-massive-scalar-field system. Interestingly, it is proved
that the resonant oscillation frequencies of this composed physical system are
determined by the characteristic zeroes of the confluent hypergeometric
function. Following this observation, we derive a remarkably compact analytical
formula for the resonant oscillation frequencies which characterize the
marginally-bound charged massive scalar field configurations. The analytically
derived resonance spectrum is confirmed by numerical computations.",1806.06831v1
2018-06-27,Resonance fluorescence from an atomic-quantum-memory compatible single photon source based on GaAs droplet quantum dots,"Single photon sources, which are compatible with quantum memories are an
important component of quantum networks. In this article, we show optical
investigations on isolated GaAs/Al$_{0.25}$Ga$_{0.75}$As quantum dots grown via
droplet epitaxy, which emit single photons on resonance with the Rb-87-D$_2$
line (780 nm). Under continuous wave resonant excitation conditions, we observe
bright, clean and narrowband resonance fluorescence emission from such a
droplet quantum dot. Furthermore, the second-order correlation measurement
clearly demonstrates the single photon emission from this resonantly driven
transition. Spectrally resolved resonance fluorescence of a similar quantum dot
yields a linewidth as narrow as 660 MHz ($ 2.7~\mu eV $), which corresponds to
a coherence time of 0.482 ns. The observed linewidth is the smallest reported
so far for strain free GaAs quantum dots grown via the droplet method. We
believe that this single photon source can be a prime candidate for
applications in optical quantum networks.",1806.10520v1
2018-06-29,Optical probing of Rayleigh wave driven magneto-acoustic resonance,"The resonant interaction of electrically excited travelling surface acoustic
waves and magnetization has been hitherto probed through the acoustic
component. In this work it is investigated using time-resolved magneto-optical
detection of magnetization dynamics. To that end, we develop an experimental
scheme where laser pulses are used both to generate the acoustic wave frequency
and to probe magnetization dynamics thus ensuring perfect phase locking. The
light polarization dependence of the signal enables to disentangle elasto-optic
and magneto-optic contributions and to obtain the in-plane and out-of-plane
dynamic magnetization components. Magnetization precession is proved to be
driven solely by the acoustic wave. Its amplitude is shown to resonate at the
same field at which we detect piezo-electrically the resonant attenuation of
the acoustic wave, clearly evidencing the magneto-acoustic resonance with high
sensitivity.",1806.11410v1
2018-07-05,Fluctuations and noise-limited sensing near the exceptional point of $\mathcal{PT}$-symmetric resonator systems,"We theoretically explore the role of mesoscopic fluctuations and noise on the
spectral and temporal properties of systems of $\mathcal{PT}$-symmetric coupled
gain-loss resonators operating near the exceptional point, where eigenvalues
and eigenvectors coalesce. We show that the inevitable detuning in the
frequencies of the uncoupled resonators leads to an unavoidable modification of
the conditions for reaching the exceptional point, while, as this point is
approached in ensembles of resonator pairs, statistical averaging significantly
smears the spectral features. We also discuss how these fluctuations affect the
sensitivity of sensors based on coupled $\mathcal{PT}$-symmetric resonators.
Finally, we show that temporal fluctuations in the detuning and gain of these
sensors lead to a quadratic growth of the optical power in time, thus implying
that maintaining operation at the exceptional point over a long period can be
rather challenging. Our theoretical analysis clarifies issues central to the
realization of $\mathcal{PT}$-symmetric devices, and should facilitate future
experimental work in the field.",1807.02157v1
2018-07-06,Quantum dynamics of a microwave resonator strongly coupled to a tunnel junction,"We consider the coupling of a single mode microwave resonator to a tunnel
junction whose contacts are at thermal equilibrium. We derive the quantum
master equation describing the evolution of the resonator field in the strong
coupling regime, where the characteristic impedance of the resonator is larger
than the quantum of resistance. We first study the case of a
normal-insulator-normal junction and show that a dc driven single photon source
can be obtained. We then consider the case of a superconductor-insulator-normal
and superconductor-insulator-superconductor junction. There, we show that the
Lamb shift induced by the junction gives rise to a nonlinear spectrum of the
resonator even when the junction induced losses are negligible. We discuss the
resulting dynamics and consider possible applications including quantum Zeno
dynamics and the realization of a qubit.",1807.02364v1
2018-07-13,Strong exciton regulation of Raman scattering in monolayer dichalcogenides,"The weakly screened electron-hole interactions in an atomically thin
semiconductor not only downshift its excitation spectrum from a quasiparticle
one, but also redistribute excitation energies and wavefunction characters with
profound effects on diverse modes of material response, including the
exciton-phonon scattering processes accessible to resonant Raman measurements.
Here we develop a first-principles framework to calculate frequency-dependent
resonant Raman intensities that includes excitonic effects and goes beyond the
Placzek approximation. We show how excitonic effects in MoS2 strongly regulate
Raman scattering amplitudes and thereby explain the puzzling near-absence of
resonant Raman response around the A and B excitons (which produce very strong
signals in optical absorption), and also the pronounced strength of the
resonant Raman response from the C exciton. Furthermore, this efficient
perturbative approach reduces the number of GW- BSE calculations from two per
Raman mode (in finite displacement) to one for all modes and affords natural
extension to higher-order resonant Raman processes.",1807.04929v1
2018-07-22,Doubly-resonant-cavity electromagnetically induced transparency,"We present an experimental study on the cavity-atom ensemble system, and
realize the doubly-resonant cavity enhanced electromagnetically induced
transparency, where both the probe and control lasers are resonant with a
Fabry-Perot cavity. We demonstrate the precise frequency manipulating of the
hybrid optical-atomic resonances, through either temperature or cavity length
tuning. In such a system, the control power can be greatly enhanced due to the
cavity, and all-optical switching is achieved with a much lower control laser
power compared to previous studies. A new theoretical model is developed to
describe the effective three-wave mixing process between spin-wave and optical
modes. Interesting non-Hermitian physics are predicted theoretically and
demonstrated experimentally. Such a doubly-resonant cavity-atom ensemble system
without a specially designed cavity can be used for future applications, such
as optical signal storage and microwave-to-optical frequency conversion.",1807.08307v1
2018-07-23,Auto-adaptive Resonance Equalization using Dilated Residual Networks,"In music and audio production, attenuation of spectral resonances is an
important step towards a technically correct result. In this paper we present a
two-component system to automate the task of resonance equalization. The first
component is a dynamic equalizer that automatically detects resonances and
offers to attenuate them by a user-specified factor. The second component is a
deep neural network that predicts the optimal attenuation factor based on the
windowed audio. The network is trained and validated on empirical data gathered
from an experiment in which sound engineers choose their preferred attenuation
factors for a set of tracks. We test two distinct network architectures for the
predictive model and find that a dilated residual network operating directly on
the audio signal is on a par with a network architecture that requires a prior
audio feature extraction stage. Both architectures predict human-preferred
resonance attenuation factors significantly better than a baseline approach.",1807.08636v1
2018-08-02,Observation of the Crossover from Photon Ordering to Delocalization in Tunably Coupled Resonators,"Networks of nonlinear resonators offer intriguing perspectives as quantum
simulators for non-equilibrium many-body phases of driven-dissipative systems.
Here, we employ photon correlation measurements to study the radiation fields
emitted from a system of two superconducting resonators, coupled nonlinearly by
a superconducting quantum interference device (SQUID). We apply a
parametrically modulated magnetic flux to control the linear photon hopping
rate between the two resonators and its ratio with the cross-Kerr rate. When
increasing the hopping rate, we observe a crossover from an ordered to a
delocalized state of photons. The presented coupling scheme is intrinsically
robust to frequency disorder and may therefore prove useful for realizing
larger-scale resonator arrays.",1808.00889v1
2018-08-02,Tunable superconducting two-chip lumped element resonator,"We have fabricated and investigated a stacked two-chip device, consisting of
a lumped element resonator on one chip, which is side-coupled to a coplanar
waveguide transmission line on a second chip. We present a full model to
predict the behavior of the device dependent on the position of the lumped
element resonator with respect to the transmission line. We identify different
regimes, in which the device can be operated. One of them can be used to tune
the coupling between the two subsystems. Another regime enables frequency
tunability of the device, without leaving the over-coupled limit for internal
quality factors of about $10^4$, while in the last regime the resonator
properties are insensitive against small variations of the position. Finally,
we have measured the transmission characteristics of the resonator for
different positions, demonstrating a good agreement with the model.",1808.01034v1
2018-08-08,Superconducting coplanar microwave resonators with operating frequencies up to 50 GHz,"We demonstrate the operation of superconducting coplanar microwave resonators
in a very large frequency range up to 50 GHz. The resonators are fabricated
from niobium thin films on sapphire substrates and optimized for these high
frequencies by small chip sizes. We study numerous harmonics of the resonators
at temperatures between 1.5 K and 6 K, and we determine quality factors of up
to 25000 at 1.5 K. As an example for spectroscopy applications of such
resonators we detect the superconducting transition of a bulk tin sample at
multiple probing frequencies.",1808.02832v1
2018-08-10,Nucleon-$α$ Scattering and Resonances in $^5$He and $^5$Li with JISP16 and Daejeon16 $NN$ interactions,"The SS-HORSE approach to analysis of resonant states is generalized to the
case of charged particle scattering utilizing analytical properties of partial
scattering amplitudes and applied to the study of resonant states in the
$^{5}$Li nucleus and non-resonant $s$-wave proton-$\alpha$ scattering within
the no-core shell model using the JISP16 and Daejeon16 $NN$ interactions. We
present also the results of calculations of neutron-$\alpha$ scattering and
resonances in the $^{5}$He nucleus with Daejeon16 and compare with results
published previously using JISP16.",1808.03394v2
2018-08-15,A differential algebra based importance sampling method for impact probability computation on Earth resonant returns of Near Earth Objects,"A differential algebra based importance sampling method for uncertainty
propagation and impact probability computation on the first resonant returns of
Near Earth Objects is presented in this paper. Starting from the results of an
orbit determination process, we use a differential algebra based automatic
domain pruning to estimate resonances and automatically propagate in time the
regions of the initial uncertainty set that include the resonant return of
interest. The result is a list of polynomial state vectors, each mapping
specific regions of the uncertainty set from the observation epoch to the
resonant return. Then, we employ a Monte Carlo importance sampling technique on
the generated subsets for impact probability computation. We assess the
performance of the proposed approach on the case of asteroid (99942) Apophis. A
sensitivity analysis on the main parameters of the technique is carried out,
providing guidelines for their selection. We finally compare the results of the
proposed method to standard and advanced orbital sampling techniques.",1808.05154v1
2018-08-18,Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba$_{0.67}$K$_{0.33}$(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$,"We use inelastic neutron scattering to study energy and wave vector
dependence of the superconductivity-induced resonance in hole-doped
Ba$_{0.67}$K$_{0.33}$(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ ($x=0,0.08$ with
$T_c\approx 37, 28$ K, respectively). In previous work on electron-doped
Ba(Fe$_{0.963}$Ni$_{0.037}$)$_2$As$_2$ ($T_N=26$ K and $T_c=17$ K), the
resonance is found to peak sharply at the antiferromagnetic (AF) ordering wave
vector ${\bf Q}_{\rm AF}$ along the longitudinal direction, but disperses
upwards away from ${\bf Q}_{\rm AF}$ along the transverse direction. For hole
doped $x=0, 0.08$ without AF order, we find that the resonance displays
ring-like upward dispersion away from ${\bf Q}_{\rm AF}$ along both the
longitudinal and transverse directions. By comparing these results with
calculations using the random phase approximation, we conclude that the
dispersive resonance is a direct signature of isotropic superconducting gaps
arising from nested hole-electron Fermi surfaces.",1808.06108v1
2018-08-30,Determining interface dielectric losses in superconducting coplanar waveguide resonators,"Superconducting quantum computing architectures comprise resonators and
qubits that experience energy loss due to two-level systems (TLS) in bulk and
interfacial dielectrics. Understanding these losses is critical to improving
performance in superconducting circuits. In this work, we present a method for
quantifying the TLS losses of different bulk and interfacial dielectrics
present in superconducting coplanar waveguide (CPW) resonators. By combining
statistical characterization of sets of specifically designed CPW resonators on
isotropically etched silicon substrates with detailed electromagnetic modeling,
we determine the separate loss contributions from individual material
interfaces and bulk dielectrics. This technique for analyzing interfacial TLS
losses can be used to guide targeted improvements to qubits, resonators, and
their superconducting fabrication processes.",1808.10347v1
2018-08-31,Transverse scattering and generalized Kerker effects in all-dielectric Mie-resonant meta-optics,"All-dielectric resonant nanophotonics lies at the heart of modern optics and
nanotechnology due to the unique possibilities to control scattering of light
from high-index dielectric nanoparticles and metasurfaces. One of the important
concepts of dielectric Mie-resonant nanophotonics is associated with the Kerker
effect that drives the unidirectional scattering of light from nanoantennas and
Huygens' metasurfaces. Here we suggest and demonstrate experimentally a novel
effect manifested in the nearly complete simultaneous suppression of both
forward and backward scattered fields. This effect is governed by the Fano
interference between an electric dipole and off-resonant quadrupoles, providing
necessary phases and amplitudes of the scattered fields to achieve the
transverse scattering. We extend this concept to dielectric metasurfaces that
demonstrate zero reflection with transverse scattering and strong field
enhancement for resonant light filtering, nonlinear effects, and sensing.",1808.10708v2
2018-12-18,Interplay of resonant states and Landau levels in functionalized graphene,"Adsorbates can drastically alter physical properties of graphene.
Particularly important are adatoms and admolecules that induce resonances at
the Dirac point. Such resonances limit electron mobilities and spin relaxation
times. We present a systematic tight-binding as well as analytical modeling to
investigate the properties of resonant states in the presence of a quantizing
magnetic field. Landau levels are strongly influenced by the resonances,
especially close to the Dirac point. Here the cyclotron motion of electrons
around a defect leads to the formation of circulating local currents which are
manifested by the appearance of side peaks around the zero-energy Landau level.
Our study is based on realistic parameters for H, F, and Cu adatoms, each
exhibiting distinct spectral features in the magnetic field. We also show that
by observing a local density of states around an adatom in the presence of
Landau levels useful microscopic model parameters can be extracted.",1812.07299v1
2018-12-24,Functional importance of noise in neuronal information processing,"Noise is an inherent part of neuronal dynamics, and thus of the brain. It can
be observed in neuronal activity at different spatiotemporal scales, including
in neuronal membrane potentials, local field potentials,
electroencephalography, and magnetoencephalography. A central research topic in
contemporary neuroscience is to elucidate the functional role of noise in
neuronal information processing. Experimental studies have shown that a
suitable level of noise may enhance the detection of weak neuronal signals by
means of stochastic resonance. In response, theoretical research, based on the
theory of stochastic processes, nonlinear dynamics, and statistical physics,
has made great strides in elucidating the mechanism and the many benefits of
stochastic resonance in neuronal systems. In this perspective, we review recent
research dedicated to neuronal stochastic resonance in biophysical mathematical
models. We also explore the regulation of neuronal stochastic resonance, and we
outline important open questions and directions for future research. A deeper
understanding of neuronal stochastic resonance may afford us new insights into
the highly impressive information processing in the brain.",1812.09897v2
2019-01-02,Two-Photon Resonance Fluorescence of a Ladder-Type Atomic System,"Multi-photon emitters are a sought-after resource in quantum photonics.
Nonlinear interactions between a multi-level atomic system and a coherent drive
can lead to resonant two-photon emission, but harvesting light from this
process has remained a challenge due to the small oscillator strengths
involved. Here we present a study of two-photon resonance fluorescence at
microwave frequencies, using a superconducting, ladder-type artificial atom, a
transmon, strongly coupled to a waveguide. We drive the two-photon transition
between the ground and second-excited state at increasingly high powers and
observe a resonance fluorescence peak whose intensity becomes comparable to
single-photon emission until it splits into a Mollow-like triplet. We measure
photon correlations of frequency-filtered spectral lines and find that while
emission at the fundamental frequency stays antibunched, the resonance
fluorescence peak at the two-photon transition is superbunched. Our results
provide a route towards the realization of multi-photon sources in the
microwave domain.",1901.00414v1
2019-01-10,Misfit strain-induced energy dissipation for graphene/MoS2 heterostructure nanomechanical resonators,"Misfit strain is inevitable in various heterostructures like the graphene/MoS
2 van der Waals heterostructure. Although the misfit strain effect on
electronic and other physical properties have been well studied, it is still
unclear how will the misfit strain affect the performance of the nanomechanical
resonator based on the graphene/MoS 2 heterostructure. By performing molecular
dynamics simulations, we disclose a misfit strain-induced decoupling phenomenon
between the graphene layer and the MoS 2 layer during the resonant oscillation
of the heterostructure. A direct relationship between the misfit strain and the
decoupling mechanism is successfully established through the retraction force
analysis. We further suggest to use the graphene/MoS 2 /graphene sandwich
heterostructure for the nanomechanical resonator application, which is able to
prevent the misfit strain-related decoupling phenomenon. These results provide
valuable information for the future application of the graphene/MoS 2
heterostructure in the nanomechanical resonator field.",1901.03023v1
2019-01-20,Wireless Power Transfer via Dielectric Loaded Multi-moded Split Cavity Resonator,"Wireless power transfer via a dielectric loaded multi-moded split cavity
resonator (SCR) is proposed. Unlike conventional inductive resonant coupling,
the scheme enables the control of both the real and imaginary parts of the
transfer impedance. It is demonstrated through measurements that the inclusion
of dielectric resonators (DRs) tuned to the SCR $TE_{012}$ mode, significantly
enhances the system figure of merit and optimal efficiency. The effect of the
DRs is shown to be related to the resonant coupling of the DRs $TE_{01\delta}$
and SCR modes, resulting in an electromagnetic induced transparency-like
window. An efficiency of 70% is achieved when the transfer distance is 7 cm, or
half wavelength. Additionally, it was shown that the efficiency is above 40%
over a relatively wide bandwidth and a wide range of optimum load impedance.",1901.06684v2
2019-01-23,All-optical dynamic modulation of spontaneous emission rate in hybrid optomechanical cavity quantum electrodynamics systems,"Recent nanofabrication technologies have miniaturized optical and mechanical
resonators, and have led to a variety of novel optomechanical systems in which
optical and mechanical modes are strongly coupled. Here we hybridize an
optomechanical resonator with two-level emitters and successfully demonstrate
all-optical dynamic control of optical transition in the two-level system by
the mechanical oscillation via the cavity quantum-electrodynamics (CQED)
effect. Employing copper-doped silicon nanobeam optomechanical resonators, we
have observed that the spontaneous emission rate of excitons bound to copper
atoms is dynamically modulated by the optically-driven mechanical oscillation
within the time scale much shorter than the emission lifetime. The result is
explained very well with an analytical model including the dynamic modulation
of the Purcell effect and the exciton population. To the best of our knowledge,
this is the first demonstration of a dynamic modulation of the spontaneous
emission rate by mechanical oscillations. Our achievement will open up a novel
field of hybrid optomechanical CQED systems in which three body--optical
transitions, optical resonance modes, and mechanical resonance modes--are
strongly coupled and will pave the way for novel hybrid quantum systems.",1901.07691v1
2019-01-24,Rapid falling of an orbiting moon to its parent planet due to tidal-seismic resonance,"Tidal force plays an important role in the evolution of the planet-moon
system. The tidal force of a moon can excite seismic waves in the planet it is
orbiting. A tidal-seismic resonance is expected when a tidal force frequency
matches a free-oscillation frequency of the planet. Here we show that when the
moon is close to the planet, the tidal-seismic resonance can cause
large-amplitude seismic waves, which can change the shape of the planet and in
turn exert a negative torque on the moon to cause it to fall rapidly toward the
planet. We postulate that the tidal-seismic resonance may be an important
mechanism which can accelerate planet accretion process. On the other hand,
tidal-seismic resonance effect can also be used to interrogate planet interior
by long term tracking of the orbital change of the moon.",1901.08561v1
2019-01-25,A fully-coupled subwavelength resonance approach to modelling the passive cochlea,"The aim of this paper is to understand the behaviour of a large number of
coupled subwavelength resonators. We use layer potential techniques in
combination with numerical computations to study the acoustic pressure field
due to scattering by a graded array of subwavelength resonators. Using this
method, we study a graded-resonance model for the cochlea. We compute the
resonant modes of the system and explore the model's ability to decompose
incoming signals. We are able to offer mathematical explanations for the
cochlea's so-called ""travelling wave"" behaviour and tonotopic frequency map.",1901.08808v4
2019-01-26,Optical switching of resonance fluorescence from a single germanium vacancy color center in diamond,"Scalable quantum photonic networks require coherent excitation of quantum
emitters. However, many solid-state systems can undergo a transition to a dark
shelving state that inhibits the fluorescence. Here we demonstrate that a
controlled gating using a weak non-resonant laser, the resonant excitation can
be recovered and amplified for single germanium vacancies (GeVs). Employing the
gated resonance excitation, we achieve optically stable resonance fluorescence
of GeV centers. Our results are pivotal for the deployment of diamond color
centers as reliable building blocks for scalable solid state quantum networks.",1901.09231v2
2019-01-30,On the Instability of Saturn's Hypothetical Retrograde Co-orbitals,"We find an interesting fact that fictitious retrograde co-orbitals of Saturn,
or small bodies inside the retrograde 1:1 resonance with Saturn, are highly
unstable in our numerical simulations. It is shown that in the presence of
Jupiter, the retrograde co-orbitals will get ejected from Saturn's co-orbital
space within a timescale of 10 Myr. This scenario reminds us of the instability
of Saturn Trojans caused by both the Great Inequality and the secular
resonances. Therefore, we carry out in-depth inspections on both mechanisms and
prove that the retrograde resonance overlap, raised by Great Inequality, cannot
serve as an explanation for the instability of retrograde co-orbitals, due to
the weakness of the retrograde 2:5 resonance with Jupiter at a low
eccentricity. However, we discover that both $\nu_5$ and $\nu_6$ secular
resonances contribute to the slow growth of the eccentricity, therefore, are
possibly the primary causes of the instability inside Saturn's retrograde
co-orbital space.",1901.10953v2
2019-02-08,Cyclotron resonance induced photogalvanic effect in surface states of 200 nm thick strained HgTe films,"We report on the study of magneto-photogalvanic and magnetotransport
phenomena in 200 nm partially strained HgTe films. This thickness is slightly
larger than the estimated critical thickness of lattice relaxation leaving the
film partially relaxed with the value of the energy gap close to zero. We show
that illumination of HgTe films with monochromatic terahertz laser radiation
results in a giant resonant photocurrent caused by the cyclotron resonance in
the surface states. The resonant photocurrent is also detected in the reference
fully strained 80 nm HgTe films previously shown to be fully gapped 3D
topological insulators. We show that the resonance positions in both types of
films almost coincide demonstrating the existence of topologically protected
surface states in thick HgTe films. The conclusion is supported by
magnetotransport experiments.",1902.02972v2
2019-02-14,Coexistence and interactions between nonlinear states with different polarizations in a monochromatically driven passive Kerr resonator,"We report on experimental observations of coexistence and interactions
between nonlinear states with different polarizations in a passive Kerr
resonator driven at a single carrier frequency. Using a fiber ring resonator
with adjustable birefringence, we partially overlap nonlinear resonances of two
orthogonal polarization modes, achieving coexistence between different
nonlinear states by locking the driving laser frequency at various points
within the overlap region. In particular, we observe coexistence between
temporal cavity solitons and modulation instability patterns, as well as
coexistence between two nonidentical cavity solitons with different
polarizations. We also observe interactions between the distinctly polarized
cavity solitons, as well as spontaneous excitation and annihilation of solitons
by a near-orthogonally polarized unstable modulation instability pattern. By
demonstrating that a single frequency driving field can support coexistence
between differentially polarized solitons and complex modulation instability
patterns, our work sheds light on the rich dissipative dynamics of multimode
Kerr resonators. Our findings could also be of relevance to the generation of
multiplexed microresonator frequency combs.",1902.05541v1
2019-03-03,Optically detected spin-mechanical resonance in silicon carbide membranes,"Hybrid spin-mechanical systems are a promising platform for future quantum
technologies. Usually they require application of additional microwave fields
to project integer spin to a readable state. We develop a theory of optically
detected spin-mechanical resonance associated with half-integer spin defects in
silicon carbide (SiC) membranes. It occurs when a spin resonance frequency
matches a resonance frequency of a mechanical mode, resulting in a shortening
of the spin relaxation time through resonantly enhanced spin-phonon coupling.
The effect can be detected as an abrupt reduction of the photoluminescence
intensity under optical pumping without application of microwave fields. We
propose all-optical protocols based on such spin-mechanical resonance to detect
external magnetic fields and mass with ultra-high sensitivity. We also discuss
room-temperature nonlinear effects under strong optical pumping, including
spin-mediated cooling and heating of mechanical modes. Our approach suggests a
new concept for quantum sensing using spin-optomechanics.",1903.00876v1
2019-03-06,Photoproduction of $K^{+}Λ$ with a Regge-plus-resonance model,"Making use of the hybrid Regge-plus-resonance model, we investigate the
process of kaon photoproduction off the proton target. We present a new model
whose free parameters were adjusted to data in and above the resonance region
and which provides an acceptable description of experimental data. The
overwhelming majority of nucleon resonances selected in this analysis overlaps
with those selected in our previous analyses and also with the Bayesian
analysis with the Regge-plus-resonance model, which we deem to be dependable. A
novel feature of our model consists in applying a different scheme for
gauge-invariance restoration, which results in a need for implementing a
contact current. As we further reveal, the choice of the gauge invariance
restoration scheme as well as the choice of either pseudoscalar or pseudovector
coupling in the strong vertex play a significant role for cross-section
predictions at forward angles where data are scarce.",1903.02292v2
2019-03-07,Coherence and indistinguishability of highly pure single photons from non-resonantly and resonantly excited telecom C-band quantum dots,"In the present work, the effect of resonant pumping schemes in improving the
photon coherence is investigated on InAs/InGaAs/GaAs quantum dots emitting in
the telecom C-band. The linewidths of transitions of multiple exemplary quantum
dots are determined under above-band pumping and resonance fluorescence via
Fourier-transform spectroscopy and resonance scans, respectively. The average
linewidth is reduced from $9.74\,\mathrm{GHz}$ in above-band excitation to
$3.50\,\mathrm{GHz}$ in resonance fluorescence underlining its superior
coherence properties. Furthermore, the feasibility of coherent state
preparation with a fidelity of $49.2\,\%$ is demonstrated, constituting a step
towards on-demand generation of coherent, single C-band photons from quantum
dots. Finally, two-photon excitation of the biexciton is investigated as a
resonant pumping scheme. A deconvoluted single-photon purity value of
$g^{(2)}_{\mathrm{HBT}}(0)=0.072\pm 0.104$ and a degree of indistinguishability
of $V_{\mathrm{HOM}}=0.894\pm0.109$ are determined for the biexciton
transition. This represents an important step towards fulfilling the
prerequisites for quantum communication applications like quantum repeater
schemes at telecom wavelength.",1903.03030v1
2019-03-08,Oscillations in electron transport caused by multiple resonances in a quantum dot-QED system in the steady-state regime,"We model the electron transport current as the photon energy is swept through
several resonances of a multi-level quantum dot, embedded in a short quantum
wire, coupled to photon cavity. We use a Markovian quantum master equation
appropriate for the long-time evolution and include the electron-electron and
both the para- and the diamagnetic electron-photon interactions via
diagonalization in a truncated many-body Fock space. Tuning the photon energy,
several anti-crossings caused by Rabi-splitting in the energy spectrum of the
quantum dot system are found. The strength of the Rabi-splittings and the
photon-exchange between the resonant states depend on the polarization of the
cavity photon field. We observe oscillations of the charge in the system and
several resonant transport current peaks for the photon energies corresponding
to the resonances in the steady-state regime.",1903.03655v2
2019-03-10,Coherent long-distance spin-qubit-transmon coupling,"Spin qubits and superconducting qubits are among the promising candidates for
a solid state quantum computer. For the implementation of a hybrid architecture
which can profit from the advantages of either world, a coherent long-distance
link is necessary that integrates and couples both qubit types on the same
chip. We realize such a link with a frequency-tunable high impedance SQUID
array resonator. The spin qubit is a resonant exchange qubit hosted in a GaAs
triple quantum dot. It can be operated at zero magnetic field, allowing it to
coexist with superconducting qubits on the same chip. We find a working point
for the spin qubit, where the ratio between its coupling strength and
decoherence rate is optimized. We observe coherent interaction between the
resonant exchange qubit and a transmon qubit in both resonant and dispersive
regimes, where the interaction is mediated either by real or virtual resonator
photons.",1903.04022v1
2019-03-20,PORT: A piezoelectric optical resonance tuner,"This abstract presents an aluminum nitride (AlN) piezoelectric actuator for
tuning optical resonance modes of silicon nitride photonic resonators. The AlN
actuator is fabricated on top of a thick silicon dioxide cladding that
encapsulates the nitride resonator and waveguide. The PORT is defined by
undercutting the cladding layer with a lateral silicon etch. It tunes the
optical wavelength by 20pm on applying 60 V to the top electrode with a 0.5nA
current draw. The thick oxide cladding preserves the resonator's loaded quality
factor Q optical of 64,000 across the entire tuning range. The first bending
mode is at 1.1MHz enabling a tuning speed of <1 {\mu}s.",1903.08479v1
2019-03-24,Soliton and quasi-soliton frequency combs due to second harmonic generation in microresonators,"We report how a doublet of the symmetric oppositely tilted bistable resonance
peaks in a microring resonator with quadratic nonlinearity set for generation
of the second harmonic can transform into a Kerr-like peak on one side of the
linear cavity resonance and into a closed loop structure disconnected from the
quasi-linear resonance on the other. Both types of the nonlinear resonances are
associated with the formation of the soliton combs for dispersion profiles of a
typical LiNbO$_3$ microring. We report bright quasi-solitons propagating on a
weakly modulated low intensity background when the group velocity dispersions
have the opposite signs for the fundamental and second harmonic. We also show
exponentially localized solitons when the dispersion signs are the same.
Finally, we demonstrate that the transition between these two types of soliton
states is associated with the closure of the forbidden gap in the spectrum of
quasi-linear waves.",1903.09975v1
2019-03-25,Eigenvalue and Resonance Asymptotics in perturbed periodically twisted tubes: Twisting versus Bending,"We consider the Dirichlet Laplacian in a three-dimensional waveguide that is
a small deformation of a periodically twisted tube. The deformation is given by
a bending and an additional twisting of the tube, both parametrized by a
coupling constant $\delta$. We expand the resolvent of the perturbed operator
near the bottom of its essential spectrum and we show the existence of exactly
one resonance, in the asymptotic regime of $\delta$ small. We are able to
perform the asymptotic expansion of the resonance in $\delta$, which in
particular permits us to give a quantitative geometric criterion for the
existence of a discrete eigenvalue below the essential spectrum. In the
particular case of perturbations of straight tubes, we are able to show the
existence of resonances not only near the bottom of the essential spectrum but
near each threshold in the spectrum. We also obtain the asymptotic behavior of
the resonances in this situation, which is generically different from the first
case.",1903.10599v1
2019-04-01,Charmed dibaryon resonances in the potential quark model,"Charmed dibaryon states with the spin-parity $J^{\pi}=0^+$, $1^+$, and
$2^+$are predicted for the two-body $Y_cN$ ($=\Lambda_c$, $\Sigma_c$, or
$\Sigma^*_c$) systems. We employ the complex scaling method for the coupled
channel Hamiltonian with the $Y_cN$-CTNN potentials, which were proposed in our
previous study. We find four sharp resonance states near the $\Sigma_c N$ and
$\Sigma^*_c N$ thresholds. From the analysis of the binding energies of partial
channel systems, we conclude that these resonance states are Feshbach
resonances. We compare the results with the $Y_c N$ resonance states in the
heavy quark limit, where the $\Sigma_c N$ and $\Sigma^*_c N$ thresholds are
degenerate, and find that they form two pairs of the heavy-quark doublets in
agreement with the heavy quark spin symmetry.",1904.00586v1
2019-04-02,Enhancing the Three-Photon Luminesce via the Resonance in Lead Halide Perovskite Metasurfaces,"Lead halide perovskites (MAPbX3) have emerged as promising materials for
photovoltaic and optoelectronic devices. However, their exceptional nonlinear
properties have not been fully exploited in nanophotonics yet. Herein we
fabricate MAPbX3 perovskite metasurfaces and explore their internal nonlinear
processes. While both of third-order harmonic generation (THG) and three-photon
luminescence are generated, the latter one is less affected by the material
loss and has been significantly enhanced by a factor of 60. The corresponding
simulation reveals that the improvement is caused by the resonant enhancement
of incident laser in perovskite metasurface. Interestingly, such kind of
resonance-enhanced three-photon luminescence holds true for metasurfaces with a
small period number of 4, enabling new applications of perovskite metasurface
in high-resolution nonlinear color nanoprinting and optical encoding. The
encoded information ""NANO"" is visible only when the incident laser is
on-resonance. The off-resonance pumping and the single-photon excitation just
produce a uniform dark or photoluminescence background.",1904.01265v1
2019-04-02,Giant Tunable Mechanical Nonlinearity in Graphene-Silicon Nitride Hybrid Resonator,"High quality factor mechanical resonators have shown great promise in
developing classical or quantum technologies. Simultaneously, progress has been
made in developing controlled mechanical nonlinearity. Here we combine these
two directions of progress in a single platform consisting of coupled Silicon
Nitride (SiNx) and graphene mechanical resonators. We show that nonlinear
response can be induced on a large area SiNx resonator mode and can be
efficiently controlled by coupling it to a gate-tunable, freely suspended
graphene mode. The induced nonlinear response of the hybrid modes, as measured
on the SiNx resonator surface is giant, with one of the highest measured
Duffing constants. We observe a novel phononic frequency comb which we use as
an alternate validation of the measured values, along with numerical
simulations which are in overall agreement with measurements.",1904.01613v3
2019-04-03,Utilization of the Superconducting Transition for Characterizing Low-Quality-Factor Superconducting Resonators,"Characterizing superconducting microwave resonators with highly dissipative
elements is a technical challenge, but a requirement for implementing and
understanding the operation of hybrid quantum devices involving dissipative
elements, e.g. for thermal engineering and detection. We present experiments on
$\lambda/4$ superconducting niobium coplanar waveguide (CPW) resonators,
terminating at the antinode by a dissipative copper microstrip via aluminum
leads, such that the resonator response is difficult to measure in a typical
microwave environment. By measuring the transmission both above and below the
superconducting transition of aluminum, we are able to isolate the resonance.
We then experimentally verify this method with copper microstrips of increasing
thicknesses, from 50 nm to 150 nm, and measure quality factors in the range of
$10\sim67$ in a consistent way.",1904.01781v2
2019-04-04,A highly accurate determination of absorbed power during nanomagnetic hyperthermia,"Absorbed power of nanoparticles during magnetic hyperthermia can be well
determined from changes in the quality factor ($Q$ factor) of a resonator, in
which the radiofrequency (RF) absorbent is placed. We present an order of
magnitude improvement in the $Q$ factor measurement accuracy over conventional
methods by studying the switch-on and off transient signals of the resonators.
A nuclear magnetic resonance (NMR) console is ideally suited to acquire the
transient signals and it also allows to employ the so-called pulse
phase-cycling to remove transient artifacts. The improved determination of the
absorbed power is demonstrated on various resonators in the 1-30 MHz range
including standard solenoids and also a birdcage resonator. This leads to the
possibility to detect minute amounts of ferrite nanoparticles which are
embedded in the body and also the amount of the absorbed power. We demonstrate
this capability on a phantom study, where the exact location of an embedded
ferrite is clearly detected.",1904.02360v1
2019-04-05,A map for systems with resonant trappings and scatterings,"Slow-fast dynamics and resonant phenomena can be found in a wide range of
physical systems, including problems of celestial mechanics, fluid mechanics,
and charged particle dynamics. Important resonant effects that control
transport in the phase space in such systems are resonant scatterings and
trappings. For systems with weak diffusive scatterings the transport properties
can be described with the Chirikov standard map, and the map parameters control
the transition between stochastic and regular dynamics. In this paper we put
forward the map for resonant systems with strong scatterings that result in
non-diffusive drift in the phase space, and trappings that produce fast jumps
in the phase space. We demonstrate that this map describes the transition
between stochastic and regular dynamics and find the critical parameter values
for this transition.",1904.02973v1
2019-04-08,"Exclusion of heavy, broad resonances from precise measurements of WZ and VH final states at the LHC","A novel search for heavy vector resonances in the $H\rightarrow b\bar{b}$ and
$Z\rightarrow b\bar{b}$ final states in association with a leptonically
decaying $V$ ($Z$ or $W$) and $W$-only respectively, is proposed. It is argued
that excesses with respect to the Standard Model prediction should be observed
in all final states (0, 1 or 2 leptons), with the 1-lepton final state being
the strongest. Since the relative strengths of these excesses depend on
branching ratios and efficiencies, this is a clear signal for the presence of
heavy resonances or their low mass tails. A general vector-triplet model is
used to explore the discovery potential as a function of the resonance mass and
width. Recent Higgs to $b\bar{b}$ observation data reported by the experiments
ATLAS and CMS are used to test the model. Current limits are extended to
resonance widths over mass as large as 9%.",1904.03995v1
2019-04-09,Arbitrary function resonance tuner of the optical microcavity with sub-MHz resolution,"The resonance frequency of an optical whispering gallery mode (WGM)
microcavity is extremely important in its various applications. Many efforts
have been made to fine tune this parameter. Here, we report the design and
implementation of a function resonance tuner of an optical microcavity with
resolution about 650 kHz (7 pm @ 1450 nm band), 20% of the optical WGM
linewidth. A piezoelectric nano-positioner is used to mechanically compress the
microsphere in its axial direction. The ultrafine frequency tuning is achieved
benefitting from the much less changes in the axial direction than equatorial
semiaxes of the microsphere and the sub-nanometer resolution of the
nano-positioner. The tuning of the resonance can be made to an arbitrary
function, dynamically, with near perfect accuracy. We have demonstrated the
periodically tuning of resonance in the sine and sigmoid function respectively,
both with over 99% fitting accuracy. This work expands the application of
microresonators greatly, especially microspheres with ultrahigh quality factor,
in multi-mode coupling system or time-floquet system.",1904.05743v1
2019-04-15,Photonic-crystal-reflector nano-resonators for Kerr-frequency combs,"We demonstrate Kerr-frequency-comb generation with nanofabricated Fabry-Perot
resonators with photonic-crystal-reflector (PCR) end mirrors. The PCR
group-velocity-dispersion (GVD) is engineered to counteract the strong normal
GVD of a rectangular waveguide fabricated on a thin, 450 nm silicon nitride
device layer. The reflectors provide the resonators with both the high optical
quality factor and anomalous GVD required for Kerr-comb generation. We report
design, fabrication, and characterization of devices in the 1550 nm wavelengths
bands, including the GVD spectrum and quality factor. Kerr-comb generation is
achieved by exciting the devices with a continuous-wave (CW) laser. The
versatility of PCRs enables a general design principle and a
material-independent device infrastructure for Kerr-nonlinear-resonator
processes, opening new possibilities for manipulation of light. Visible and
multi-spectral-band resonators appear to be natural extensions of the PCR
approach.",1904.07289v2
2019-04-17,A cotunneling mechanism for all-electrical Electron Spin Resonance of single adsorbed atoms,"The recent development of all-electrical electron spin resonance (ESR) in a
scanning tunneling microscope (STM) setup has opened the door to vast
applications. Despite the fast growing number of experimental works on STM-ESR,
the fundamental principles remains unclear. By using a cotunneling picture, we
show that the spin resonance signal can be explained as a time-dependent
variation of the tunnel barrier induced by the alternating electric driving
field. We demonstrate how this variation translates into the resonant frequency
response of the direct current. Our cotunneling theory explains the main
experimental findings. Namely, the linear dependence of the Rabi flop rate with
the alternating bias amplitude, the absence of resonant response for
spin-unpolarized currents, and the weak dependence on the actual atomic
species.",1904.08183v1
2019-04-18,On spurious solutions encountered in Helmholtz scattering resonance computations in R^d with applications to nano-photonics and acoustics,"In this paper, we consider a sorting scheme for potentially spurious
scattering resonant pairs in one- and two-dimensional electromagnetic problems
and in three-dimensional acoustic problems. The novel sorting scheme is based
on a Lippmann-Schwinger type of volume integral equation and can, therefore, be
applied to structures with graded materials as well as to configurations
including piece-wise constant material properties. For TM/TE polarized
electromagnetic waves and for acoustic waves, we compute first approximations
of scattering resonances with finite elements. Then, we apply the novel sorting
scheme to the computed eigenpairs and use it to mark potentially spurious
solutions in electromagnetic and acoustic scattering resonances computations at
a low computational cost. Several test cases with Drude-Lorentz dielectric
resonators as well as with graded material properties are considered.",1904.08812v3
2019-04-20,Hybridization-induced resonances with high quality factor in a plasmonic concentric ring-disk nanocavity,"Plasmonic resonators have drawn more attention due to the ability to confine
light into subwavelength scale. However, they always suffer from a low quality
(Q) factor owing to the intrinsic loss of metal. Here, we numerically propose a
plasmonic resonator with ultra-high Q factor based on plasmonic
metal-insulator-metal (MIM) waveguide structures. The resonator consists of a
disk cavity surrounded by a concentric ring cavity, possessing an ultra-small
volume. Arising from the plasmon hybridization between plasmon modes in the
disk and ring cavity, the induced bonding hybridized modes have ultra-narrow
full wave at half maximum (FWHM) as well as ultra-high Q factors. The FWHM can
be nearly 1 nm and Q factor can be more than 400. Furthermore, such device can
act as a refractive index sensor with ultra-high figure of merit (FOM). This
work provides a novel approach to design plasmonic high-Q-factor resonators,
and has potential on-chip applications such as filters, sensors and nanolasers.",1904.09437v1
2019-04-26,Three-body scattering: Ladders and Resonances,"We discuss unitarity constraints on the dynamics of a system of three
interacting particles. We show how the short-range interaction that describes
three-body resonances can be separated from the long-range exchange processes,
in particular the one-pion-exchange process. It is demonstrated that unitarity
demands a specific functional form of the amplitude with a clear
interpretation: the bare three-particle resonances are dressed by the initial-
and final-state interaction, in a way that is consistent with the considered
long-range forces. We postulate that the resonance kernel admits a
factorization in the energy variables of the initial- and the final-state
particles. The factorization assumption leads to an algebraic form for the
unitarity equations, which is reminiscent of the well-known two-body-unitarity
condition and approaches it in the limit of the narrow-resonance approximation.",1904.11894v1
2019-08-14,Spectral properties of Neumann-Poincare operator and anomalous localized resonance in elasticity beyond quasi-static limit,"This paper is concerned with the polariton resonances and their application
for cloaking due to anomalous localized resonance (CALR) for the elastic system
within the finite frequency regime beyond the quasi-static approximation. We
first derive the complete spectral system of the Neumann-Poincar\'e operator
associated with the elastic system within the finite frequency regime. Based on
the obtained spectral results, we construct a broad class of elastic
configurations that can induce polariton resonances beyond the quasi-static
limit. As an application, the invisibility cloaking effect is achieved through
constructing a class of core-shell-matrix metamaterial structures provided the
source is located inside a critical radius. Moreover, if the source is located
outside the critical radius, it is proved that there is no resonance.",1908.05064v3
2019-08-15,Quantum resonances of kicked rotor in the position representation,"The study of quantum resonances in the chaotic atom-optics kicked rotor
system is of interest from two different perspectives. In quantum chaos, it
marks out the regime of resonant quantum dynamics in which the atomic cloud
displays ballistic mean energy growth due to coherent momentum transfer.
Secondly, the sharp quantum resonance peaks are useful in the context of
measurement of Talbot time, one of the parameter that helps in precise
measurement of fine structure constant. Most of the earlier works rely on
fidelity based approach and have proposed Talbot time measurement through
experimental determination of the momentum space probability density of the
periodically kicked atomic cloud. Fidelity approach has the disadvantage that
phase reversed kicks need to be imparted as well which potentially leads to
dephasing. In contrast to this, in this work, it is theoretically shown that,
without manipulating the kick sequences, the quantum resonances through
position space density can be measured more accurately and is experimentally
feasible as well.",1908.05561v1
2019-08-19,Resonant-state expansion for planar photonic-crystal structures,"We present a new paradigm in the field of photonic crystals and
metamaterials, applying the resonant-state expansion (RSE) to planar
photonic-crystal structures. The RSE allows us to understand and quantify
optical resonances in photonic-crystal structures in terms of the analytic
resonant states of a homogeneous planar waveguide. The RSE provides an
efficient and reliable tool for accurate calculation of a complete set of the
resonant states of a photonic-crystal slab, which is required for the correct
description and a better understanding of its optical spectra. For the proof of
principle, numerical verification of the RSE, and demonstration of its
unprecedented accuracy and convergence, an infinite planar photonic crystal
slab periodic in one dimension is taken as an example. To illustrate the power
of the present approach, we consider the mode evolution with the amplitude of
the periodic modulation, revealing the role of the guided modes in the
formation of bound states in the continuum.",1908.06916v1
2019-08-12,Triple-Poles Complementary Split Ring Resonator for Sensing Diabetics Glucose Levels at cm-Band,"Microwave sensors are very promising for sensing the blood glucose levels
non-invasively for their non-ionizing nature, miniaturized sizing, and low
health risks for diabetics. All these features offer the possibility for
realizing a portable non-invasive glucose sensor for monitoring glucose levels
in real time. In this article, we propose a triple poles complementary split
ring resonator (CSRR) produced on a FR4 substrate in microstrip technology in
the cm-wave band (1-6 GHz). The proposed bio-sensor can detect the small
variations in the dielectric properties (relative permittivity and dielectric
losses) of glucose in the blood mimicking aqueous solutions due their intense
interaction with the electromagnetic field at harmonic resonances. The
resonator exhibits higher sensitivity performance at the different resonances
compared to the single and double-poles counterparts as demonstrated by
simulations in a 3D full-wave EM solver.",1908.07407v1
2019-11-05,Overcoming the efficiency-bandwidth tradeoff for optical harmonics generation using nonlinear time-variant resonators,"Highly resonant photonic structures, such as cavities and metasurfaces, can
dramatically enhance the efficiency of nonlinear processes by utilizing strong
optical field enhancement at the resonance. The latter, however, comes at the
expense of the bandwidth. Here, we overcome such tradeoff by utilizing
time-varying resonant structures. Using harmonics generation as an example, we
show that the amplitude and phase format of the excitation, as well as the time
evolution of the resonator, can be optimized to yield the strongest nonlinear
response. We find the conditions for an efficient synthesis of electromagnetic
signals that surpass the cavity bandwidth, and discuss a potential experimental
realization of this concept.",1911.02036v1
2019-11-09,Minnaert resonances for bubbles in soft elastic materials,"Minnaert resonance is a well known physical phenomenon and it has many
important applications, in particular in the effective realisation of acoustic
metamaterials using bubbly mediums in recent years. In this paper, motived by
the Minnaert resonance, we consider the low-frequency resonance for acoustic
bubbles embedded in soft elastic materials. This is a hybrid physical process
that couples the acoustic and elastic wave propagations. By delicately and
subtly balancing the acoustic and elastic parameters as well as the geometry of
the bubble, we show that Minnaert resonance can (approximately) occur for
rather general constructions. Our study poses a great potential for the
effective realisation of negative elastic materials by using bubbly elastic
mediums.",1911.03718v2
2019-11-10,Engineering the dissipation of crystalline micromechanical resonators,"High quality micro- and nano-mechanical resonators are widely used in
sensing, communications and timing, and have future applications in quantum
technologies and fundamental studies of quantum physics. Crystalline thin-films
are particularly attractive for such resonators due to their prospects for high
quality, intrinsic stress and yield strength, and low dissipation. However,
when grown on a silicon substrate, interfacial defects arising from lattice
mismatch with the substrate have been postulated to introduce additional
dissipation. Here, we develop a new backside etching process for single crystal
silicon carbide microresonators that allows us to quantitatively verify this
prediction. By engineering the geometry of the resonators and removing the
defective interfacial layer, we achieve quality factors exceeding a million in
silicon carbide trampoline resonators at room temperature, a factor of five
higher than without the removal of the interfacial defect layer. We predict
that similar devices fabricated from ultrahigh purity silicon carbide and
leveraging its high yield strength, could enable room temperature quality
factors as high as $6\times10^9$",1911.03835v2
2019-11-10,Influence of resonances on the noise performance of SQUID susceptometers,"Scanning Superconducting Quantum Interference Device (SQUID) Susceptometry
simultaneously images the local magnetic fields and susceptibilities above a
sample with sub-micron spatial resolution. Further development of this
technique requires a thorough understanding of the current, voltage, and flux
characteristics of scanning SQUID susceptometers. These sensors often have
striking anomalies in their current-voltage characteristics, which we believe
to be due to electromagnetic resonances. The effect of these resonances on the
performance of these SQUIDs is unknown. To explore the origin and impact of the
resonances, we have developed a model that qualitatively reproduces the
experimentally-determined current-voltage characteristics of our scanning SQUID
susceptometers. We use this model to calculate the noise characteristics of
SQUIDs of different designs. We find that the calculated ultimate flux noise is
better in susceptometers with damping resistors that diminish the resonances
than susceptometers without damping resistors. Such calculations will enable
the optimization of the signal-to-noise characteristics of scanning SQUID
susceptometers.",1911.03836v2
2019-11-13,Coupling Rydberg atoms to microwave fields in a superconducting coplanar waveguide resonator,"Rydberg helium atoms traveling in pulsed supersonic beams have been coupled
to microwave fields in a superconducting coplanar waveguide (CPW) resonator.
The atoms were initially prepared in the 1s55s $^3$S$_1$ Rydberg level by
two-color two-photon laser excitation from the metastable 1s2s $^3$S$_1$ level.
Two-photon microwave transitions between the 1s55s $^3$S$_1$ and 1s56s
$^3$S$_1$ levels were then driven by the 19.556 GHz third-harmonic microwave
field in a quarter-wave CPW resonator. This superconducting microwave resonator
was fabricated from niobium nitride on a silicon substrate and operated at
temperatures between 3.65 and 4.30 K. The populations of the Rydberg levels in
the experiments were determined by state-selective pulsed electric field
ionization. The coherence of the atom-resonator coupling was studied by
time-domain measurements of Rabi oscillations.",1911.05513v2
2019-11-15,Hybrid Magnetoacoustic Metamaterials for Ultrasound Control,"We propose a class of metamaterials in which propagation of acoustic waves is
controlled magnetically through magnetoelastic coupling. The metamaterials are
formed by a periodic array of thin magnetic layers ('resonators') embedded in a
non-magnetic matrix. Acoustic waves carrying energy through the structure
hybridize with the magnetic modes of the resonators ('Fano resonance'). This
leads to a rich set of effects, enhanced by Bragg scattering and being most
pronounced when the magnetic resonance frequency is close to or lies within
acoustic band gaps. The acoustic reflection from the structure exhibits
magnetically induced transparency and Borrmann effect. Our analysis shows that
the combined effect of the Bragg scattering and Fano resonance may overcome the
magnetic damping ubiquitous in realistic systems. This paves a route towards
application of such structures in wave computing and signal processing",1911.06774v1
2019-11-17,Observation of enhanced coherence in Josephson SQUID cavities using a hybrid fabrication approach,"We study the coherence of flux-tunable Josephson junction resonators made
with two different fabrication processes. In the first process, devices are
made using a single step of evaporation in which the resonator and the
junctions of the SQUID are made at the same time. In the second process,
devices are made with an identical geometry, but in which the resonators are
made from a MoRe superconding layer to which an the junctions are added later
in a second step. To characterize the coherence of the two types of SQUID
cavities, we observe and analyze the quality factor of their resonances as a
function of flux and photon number. Despite a detailed cleaning process applied
during fabrication, the single-step Al devices show significantly worse quality
factor than the hybrid devices, and conclude that a the hybrid technique
provides a much more reliable approach for fabricating high-Q flux-tunable
resonators.",1911.07119v1
2019-11-22,Resonant field enhancement near bound states in the continuum on periodic structures,"On periodic structures sandwiched between two homogeneous media, a bound
state in the continuum (BIC) is a guided Bloch mode with a frequency within the
radiation continuum. BICs are useful, since they give rise to high
quality-factor ($Q$-factor) resonances that enhance local fields for
diffraction problems with given incident waves. For any BIC on a periodic
structure, there is always a surrounding family of resonant modes with
$Q$-factors approaching infinity. We analyze field enhancement around BICs
using analytic and numerical methods. Based on a perturbation method, we show
that field enhancement is proportional to the square-root of the $Q$-factor,
and it depends on the adjoint resonant mode and its coupling efficiency with
incident waves. Numerical results are presented to show different asymptotic
relations between the field enhancement and the Bloch wavevector for different
BICs. Our study provides a useful guideline for applications relying on
resonant enhancement of local fields.",1911.10058v1
2019-11-26,Ultrastrong coupling between a microwave resonator and antiferromagnetic resonances of rare earth ion spins,"Quantum magnonics is a new and active research field, leveraging the strong
collective coupling between microwaves and magnetically ordered spin systems.
To date work in quantum magnonics has focused on transition metals and almost
entirely on ferromagnetic resonances in yttrium iron garnet (YIG).
Antiferromagnetic systems have gained interest as they produce no stray field,
and are therefore robust to magnetic perturbations and have narrow, shape
independent resonant linewidths. Here we show the first experimental evidence
of ultrastrong-coupling between a microwave cavity and collective
antiferromagnetic resonances (magnons) in a rare earth crystal. The combination
of the unique optical and spin properties of the rare earths and collective
antiferromagnetic order paves the way for novel quantum magnonic applications.",1911.11311v1
2019-12-01,Quantum Efficiency Enhancement by Mie Resonance from GaAs Photocathodes Structured with Surface Nanopillar Arrays,"A new type of negative electron affinity (NEA) photocathode based on GaAs
nanopillar array (NPA) Mie-type resonators was demonstrated for the first time.
For visible wavelengths, the Mie resonances in GaAs NPA reduced light
reflectivity to less than 6 percent compared to a typical value great then 35
percent. Other benefits of NPA resonators include an enhanced density of
optical states due to increased light concentration and increased electron
emission area. These features resulted in improved photoemission performance at
the resonance wavelength demonstrating maximum quantum efficiency 3.5 times
greater than a GaAs wafer photocathode without the NPA structure. This
optically dark photocathode (sub-percentage light reflectance over visible
wavelengths) but possessing electrically high-brightness (enhanced electron
emission) provides new opportunities for practical applications such as
large-scale electron accelerators, high-resolution night-vision imaging and low
energy electron microscopy.",1912.00348v1
2019-12-03,High partial-wave Feshbach resonances in an ultracold $^6$Li-$^{133}$Cs mixture,"We measure higher partial wave Feshbach resonances in an ultracold mixture of
fermionic $^6$Li and bosonic $^{133}$Cs by magnetic field dependent atom-loss
spectroscopy. For the $p$-wave Feshbach resonances we observe triplet
structures corresponding to different projections of the pair rotation angular
momentum onto the external magnetic field axis.
  We attribute the splittings to the spin-spin and spin-rotation couplings by
modelling the observation using a full coupled-channel calculation. Comparison
with an oversimplified model, estimating the spin-rotation coupling by
describing the weakly bound close-channel molecular state with the perturbative
multipole expansion, reveals the significant contribution of the molecular
wavefunction at short internuclear distances. Our findings highlight the
potential of Feshbach resonances in providing precise information on short- and
intermediate-range molecular couplings and wavefunctions. The observed $d$-wave
Feshbach resonances allow us to refine the LiCs singlet and triplet
ground-state molecular potential curves at large internuclear separations.",1912.01264v1
2019-12-10,AlN Combined Overtone Resonators for the 5G mmWave Spectrum,"This work presents a new acoustic MEMS resonator technology, dubbed Aluminum
Nitride (AlN) Combined Overtone Resonator (COR), capable of addressing the
filter requirements for the 5G mmWave spectrum in the 6-40GHz range. The COR
exploits the multimodal excitation of two higher-order Lamb waves (2nd and 3rd
order Asymmetrical Lamb Waves) in a suspended thin-film AlN plate to transduce
a 2-dimensional vibration mode with high electromechanical coupling coefficient
kt2 (up to 1.9%) and quality factor Q >1100 at twice the frequency of a
fundamental thickness-extensional mode in the same structure. Analytical and
finite-element method (FEM) models are developed to describe the working
principle of the COR technology and predict the achievable kt2, Q and
lithographic frequency tunability. An 8.8 GHz COR prototype was fabricated
showing a high kt2~0.3% (using a simple top-electrode-only configuration with a
2-mask process) and a groundbreaking Q~1100 which is the highest ever achieved
among piezoelectric resonators above 6 GHz. The f-Q product ~1x10e13 is the
highest among all demonstrated piezoelectric resonators with metallic coverage
>50%. Additionally, the capability of the COR technology to deliver contiguous
filters with bandwidths between 355 and 592 MHz (aggregated BW>2GHz) in the
mmWave spectrum, with relaxed lithographic requirements, is demonstrated by
FEM.",1912.04515v1
2019-12-10,Probabilistic motional averaging,"In a continuous measurement scheme a spin-1/2 particle can be measured and
simultaneously driven by an external resonant signal. When the driving is weak,
it does not prevent the particle wave-function from collapsing and a detector
randomly outputs two responses corresponding to the states of the particle. In
contrast, when driving is strong, the detector returns a single response
corresponding to the mean of the two single-state responses. This situation is
similar to a motional averaging, observed in nuclear magnetic resonance
spectroscopy. We study such quantum system, being periodically driven and
probed, which consists of a qubit coupled to a quantum resonator. It is
demonstrated that the transmission through the resonator is defined by the
interplay between driving strength, qubit dissipation, and resonator linewidth.
We demonstrate that our experimental results are in good agreement with
numerical and analytical calculations.",1912.04557v1
2019-12-11,Generation of doubly excited Rydberg states based on Rydberg antiblockade in a cold atomic ensemble,"Interaction between Rydberg atoms can significantly modify Rydberg excitation
dynamics. Under a resonant driving field the Rydberg-Rydberg interaction in
high-lying states can induce shifts in the atomic resonance such that a
secondary Rydberg excitation becomes unlikely leading to the Rydberg blockade
effect. In a related effect, off-resonant coupling of light to Rydberg states
of atoms contributes to the Rydberg anti-blockade effect where the Rydberg
interaction creates a resonant condition that promotes a secondary excitation
in a Rydberg atomic gas. Here, we study the light-matter interaction and
dynamics of off-resonant two-photon excitations and include two- and three-atom
Rydberg interactions and their effect on excited state dynamics in an ensemble
of cold atoms. In an experimentally-motivated regime, we find the optimal
physical parameters such as Rabi frequencies, two-photon detuning, and pump
duration to achieve significant enhancement in the probability of generating
doubly-excited collective atomic states. This results in large auto-correlation
values due to the Rydberg anti-blockade effect and makes this system a
potential candidate for a high-purity two-photon Fock state source.",1912.05675v1
2019-12-23,Large $d_{33}$ Piezoelectric-Polymer Composites For RF Acoustic Resonators,"While piezoelectric transduction enables designing acoustic resonators
operating at multi-GHz frequencies, the deposition of piezoelectric materials
typically requires high temperature processes and specific crystallographic
orientation of substrates, thus imposing a limitation on materials that could
be used. In this paper we present a piezoelectrically transduced thickness mode
acoustic resonator that employs piezoelectric (PMNPT) nanoparticles embedded in
a polymer (SU8) matrix. This composite material is deposited using standard
resist-spin coaters and is thus compatible with a variety of substrates. The
device presented here uses a double side polished single crystal silicon wafer
as the low loss acoustic substrate for the resonator and $1.7\mu m$ thick
SU8-PMNPT composite film as the actuator, and exhibits large effective
piezoelectric coefficient $(d_{33})$ of $216pm/V$, and we experimentally
demonstrate efficient transduction of acoustic resonances at frequencies up to
$1.5GHz$.",1912.10713v1
2020-03-21,Extended Prony Analysis on Power System Oscillation Under a Near-Resonance Condition,"Power system oscillations under a large disturbance often exhibit distorted
waveforms as captured by increasingly deployed phasor measurement units. One
cause is the occurrence of a near-resonance condition among several dominant
modes that are influenced by nonlinear transient dynamics of generators. This
paper proposes an Extended Prony Analysis method for measurement-based modal
analysis. Based on the normal form theory, it compares analyses on transient
and post-transient waveforms to distinguish a resonance mode caused by a
near-resonance condition from natural modes so that the method can give more
accurate modal properties than a traditional Prony Analysis method, especially
for large disturbances. The new method is first demonstrated in detail on
Kundur's two-area system and then tested on the IEEE 39-bus system to show its
performance under a near-resonance condition.",2003.09651v1
2020-03-23,Gate-tunable trion switch for excitonic device applications,"Trions are excitonic species with a positive or negative charge, and thus,
unlike neutral excitons, the flow of trions can generate a net detectable
charge current. Trions under favourable doping conditions can be created in a
coherent manner using resonant excitation. In this work, we exploit these
properties to demonstrate a gate controlled trion switch in a few-layer
graphene/monolayer WS2/monolayer graphene vertical heterojunction. By using a
high resolution spectral scan through a temperature controlled variation of the
bandgap of the WS2 sandwich layer, we obtain a gate voltage dependent vertical
photocurrent strongly relying on the spectral position of the excitation, and
the photocurrent maximizes when the excitation energy is resonant with the
trion peak position. Further, the resonant photocurrent thus generated can be
effectively controlled by a back gate voltage applied through the incomplete
screening of the bottom monolayer graphene, and the photocurrent strongly
correlates with the gate dependent trion intensity, while the non-resonant
photocurrent exhibits only a weak gate dependence -unambiguously proving a
trion driven photocurrent generation under resonance. We estimate a sub-100 fs
switching time of the device. The findings are useful towards demonstration of
ultra-fast excitonic devices in layered materials.",2003.10108v1
2020-03-25,Particle resonances and trapping of direct laser acceleration in a laser-plasma channel,"As one of the leading acceleration mechanisms in laser-driven underdense
plasmas, direct laser acceleration (DLA) is capable of producing
high-energy-density electron beams in a plasma channel for many applications.
However, the mechanism relies on highly nonlinear particle-laser resonances,
rendering its modeling and control to be very challenging. Here, we report on
novel physics of the particle resonances and, based on that, define a potential
path toward more controlled DLA. Key findings are acquired by treating the
electron propagation angle independently within a comprehensive model. This
approach uncovers the complete particle resonances over broad propagation
angles, the physical regimes under which paraxial/non-paraxial dynamics
dominates, a unified picture for different harmonics, and crucially, the
physical accessibility to these particle resonances. These new insights can
have important implications where we address the basic issue of particle
trapping as an example. We show how the uncovered trapping parameter space can
lead to better acceleration control. More implications for the development of
this basic type of acceleration are discussed.",2003.11654v2
2020-05-13,On the interpretation of non-resonant phenomena at colliders,"With null results in resonance searches at the LHC, the physics potential
focus is now shifting towards the interpretation of non-resonant phenomena. An
example of such shift is the increased popularity of the EFT programme. We can
embark on such programme owing to good integrated luminosity and an excellent
understanding of the detectors, which will allow these searches to become more
intense as the LHC continues. In this paper we provide a framework to perform
this interpretation in terms of a diverse set of scenarios, including {\it 1.)
} generic heavy new physics described at low energies in terms of a derivative
expansion, such as in the EFT approach, {\it 2.)} very light particles with
derivative couplings, such as axions or other light pseudo-Goldstone bosons,
and {\it 3.)} the effect of a quasi-continuum of resonances, which can come
from a number of strongly-coupled theories, extra-dimensional models, clockwork
set-ups and their deconstructed cousins. These scenarios are not equivalent
despite all non-resonant, although the matching among some of them is possible
and we provide it in this paper.",2005.06492v1
2020-05-14,Impurity-induced resonant spinon zero modes in Dirac quantum spin-liquids,"Quantum spin-liquids are strongly correlated phases of matter displaying a
highly entangled ground state. Due to their unconventional nature, finding
experimental signatures of these states has proven to be a remarkable
challenge. Here we show that the effects of local impurities can provide strong
signatures of a Dirac quantum spin-liquid state. Focusing on a gapless Dirac
quantum spin-liquid state as realized in NaYbO$_2$, we show that single
magnetic impurity coupled to the quantum spin-liquid state creates a resonant
spinon peak at zero frequency, coexisting the original Dirac spinons. We
explore the spatial dependence of this zero-bias resonance, and show how
different zero modes stemming from several impurities interfere. We finally
address how such spinon zero-mode resonances can be experimentally probed with
inelastic spectroscopy and electrically-driven paramagnetic resonance with
scanning tunnel microscopy. Our results put forward impurity engineering as a
means of identifying Dirac quantum spin-liquids with scanning probe techniques,
highlighting the dramatic impact of magnetic impurities in a macroscopically
entangled many-body ground state.",2005.06896v2
2020-05-13,Analysis and Design Considerations for Achieving the Fundamental Limits of Phase Noise in mmWave Oscillators with On-Chip MEMS Resonator,"Very small electromechanical coupling coefficient in micro-electromechanical
systems (MEMS) or acoustic resonators is quite of a concern for oscillator
performance, specially at mmWave frequencies. This small coefficient is the
manifestation of the small ratio of motional capacitance to static capacitance
in the resonators. This work provides a general solution to overcome the
problem of relatively high static capacitance at mmWave frequencies and
presents analysis and design techniques for achieving extremely low phase noise
and a very high figure-of-merit (FoM) in an on-chip MEMS resonator based mmWave
oscillator. The proposed analysis and techniques are validated with design and
simulation of a 30 GHz oscillator with MEMS resonator having quality factor of
10,000 in 14 nm GF technology. Post layout simulation results show that it
achieves a phase noise of -132 dBc/Hz and FoM of 217 dBc/Hz at offset of 1 MHz.",2005.07138v1
2020-05-20,Thermal radiation dominated heat transfer in nanomechanical silicon nitride drum resonators,"Nanomechanical silicon nitride (SiN) drum resonators are currently employed
in various fields of applications that arise from their unprecedented frequency
response to physical quantities. In the present study, we investigate the
thermal transport in nanomechanical SiN drum resonators by analytical
modelling, computational simulations, and experiments for a better
understanding of the underlying heat transfer mechanism causing the thermal
frequency response. Our analysis indicates that radiative heat loss is a
non-negligible heat transfer mechanism in nanomechanical SiN resonators
limiting their thermal responsivity and response time. This finding is
important for optimal resonator designs for thermal sensing applications as
well as cavity optomechanics.",2005.10156v1
2020-05-26,Localization of electronic states resulting from electronic topological transitions in the Mo$_{1-x}$Re$_x$ alloys: A photoemission study,"We present the results of resonant photoemission spectroscopy experiments on
the Mo$_{1-x}$Re$_{x}$ alloy compositions spanning over two electronic
topological transitions (ETT) at the critical concentrations $x_{C1}$ = 0.05
and $x_{C2}$ = 0.11. The photoelectrons show an additional resonance ($R3$) in
the constant initial state (CIS) spectra of the alloys along with two
resonances ($R1$ and $R2$) which are similar to those observed in molybdenum.
All the resonances show Fano-like line shapes. The asymmetry parameter $q$ of
the resonances $R1$ and $R3$ of the alloys is observed to be large and
negative. Our analysis suggests that the origin of large negative q is
associated with phonon assisted inter band scattering between the Mo-like
states and the narrow band that appeared due to the ETT.",2005.12835v1
2020-06-14,Resonant-amplified and invisible Bragg scattering based on spin coalescing modes,"Unlike a real magnetic field, which separates the energy levels of particle
with opposite spin polarization, a complex field can lead to a special kind of
spectral degeneracy, known as exceptional point (EP), at which two spin
eigenmodes coalesce. It allows an EP impurity to be an invisible scattering
center for a fermion with the resonant spin polarization, but an amplifying
emitter for opposite polarization. We show that a pair of conjugate EP modes
supports resonant mutual stimulation, acting as a resonant amplifier based on
the underlying mechanism of positive-feedback loop. Together with other
Hermitian eigenmodes, a fermion with EP polarization exhibits some exclusive
dynamics, referred to as EP dynamics. We construct several typical
superlattices, which are built up by embedding EP-impurity arrays in a
Hermitian two-dimensional square lattice. Numerical simulations are performed
to demonstrate resonant amplification and invisibility of Bragg scattering.",2006.07875v2
2020-06-16,Studying $Λ^*$ resonances in the $p \bar p \rightarrow Λ \barΛη$ reaction,"In this work, we make a theoretical study on the $p \bar p \rightarrow
\Lambda \bar\Lambda \eta$ reaction for antiproton beam energy from threshold to
4GeV within an effective Lagrangian approach and isobar model. By assuming this
reaction is dominated by the excitation of $\Lambda$ and $\bar \Lambda$
resonances in intermediate states, we calculate the total cross sections and
give the predictions of the angular distribution and invariant mass spectrum of
final particles. In particular, we discuss the possibility to verify the
existence of a narrow $\Lambda$ resonance found in the process of $K^- p\to
\eta \Lambda$ in the present reaction. It shows that the $p \bar p \rightarrow
\bar \Lambda \Lambda \eta$ reaction can provide us with valuable information
about the $\Lambda$ resonances having significant couplings to $\bar K N$ and
$\Lambda\eta$ channels. Thus the experimental data of this reaction will be a
good supplement to the $\bar K N\to\eta \Lambda$ scattering data for studying
$\Lambda$ resonances.",2006.09195v1
2020-06-16,Quantum Coherence Resonance,"It is shown that coherence resonance, a phenomenon in which regularity of
noise-induced oscillations in nonlinear excitable systems is maximized at a
certain optimal noise intensity, can be observed in quantum dissipative
systems. We analyze a quantum van der Pol system subjected to squeezing, which
exhibits bistable excitability in the classical limit, by numerical simulations
of the quantum master equation. We first demonstrate that quantum coherence
resonance occurs in the semiclassical regime, namely, the regularity of the
system's oscillatory response is maximized at an optimal intensity of quantum
fluctuations, and interpret this phenomenon by analogy with classical noisy
excitable systems using semiclassical stochastic differential equations. This
resonance persists under moderately strong quantum fluctuations for which the
semiclassical description is invalid. Moreover, we investigate even stronger
quantum regimes and demonstrate that the regularity of the system's response
can exhibit the second peak as the intensity of the quantum fluctuations is
further increased. We show that this second peak of resonance is a strong
quantum effect that cannot be interpreted by a semiclassical picture, in which
only a few energy states participate in the system dynamics.",2006.09203v2
2020-06-22,Two-photon exchange from intermediate state resonances in elastic electron-proton scattering,"We use a recently developed dispersive approach to compute the two-photon
exchange (TPE) correction to elastic electron-proton scattering, including
contributions from hadronic $J^P=1/2^\pm$ and $3/2^\pm$ resonant intermediate
states below~1.8~GeV. For the transition amplitudes from the proton ground
state to the resonant excited states we employ new exclusive meson
electroproduction data from CLAS at $Q^2 \lesssim 5$~GeV$^2$, and we explore
the effects of both fixed and dynamic widths for the resonances. Among the
resonant states, the $N(1520)~\!3/2^-$ becomes dominant for $Q^2 \gtrsim
2$~GeV$^2$, with a sign opposite to the comparably sized $\Delta(1232)~\!3/2^+$
contribution, leading to an overall increase in the size of the TPE correction
to the cross section relative to the nucleon only contribution at higher $Q^2$
values. The results are in good overall agreement with recent $e^+ p$ to $e^-
p$ cross section ratio and polarization transfer measurements, and provide
compelling evidence for a resolution of the electric to magnetic form factor
ratio discrepancy.",2006.12543v1
2020-06-23,Resonating AdS soliton,"The AdS soliton is a nonsingular spacetime that has a flat conformal boundary
with a compact $S^1$ direction. We find a horizonless cohomogeneity-1 metric
that describes nonlinear gravitational oscillations of the AdS soliton in five
dimensions. We call this spacetime the resonating AdS soliton. This solution is
obtained as the nonlinear extension of normal modes of the AdS soliton dual to
spin-2 glueball excitations. The boundary energy momentum tensor of the
resonating AdS soliton has time periodic components, and it is interpreted as a
coherently excited state in the dual field theory. Physical quantities of the
resonating AdS soliton are multivalued at a fixed energy, suggesting a
transition between different frequency solutions. The energy of the resonating
AdS soliton is higher than that of the undeformed AdS soliton, in accordance
with the positive energy conjecture proposed by Horowitz and Myers.",2006.12783v2
2020-06-24,Thermo-optical dynamics of a nonlinear GaInP photonic crystal nanocavity depend on the optical mode profile,"We measure the dynamics of the thermo-optical nonlinearity of both a mode-gap
nanocavity and a delocalized mode in a
Ga$_{\mathrm{0.51}}$In$_{\mathrm{0.49}}$P photonic crystal membrane. We model
these results in terms of heat transport and thermo-optical response in the
material. By step-modulating the optical input power we push the nonlinear
resonance to jump between stable branches of its response curve, causing
bistable switching. An overshoot of the intensity followed by a relaxation tail
is observed upon bistable switching. In this way, the thermal relaxation of
both the localized resonance and the delocalized resonance is measured.
Significant difference in decay time is observed and related to the optical
mode profile of the resonance. We reproduce the observed transient behavior
with our thermo-optical model, implementing a non-instantaneous nonlinearity,
and taking into account the optical mode profile of the resonance, as
experimentally measured.",2006.13665v1
2020-06-24,Full-heavy tetraquarks in constituent quark models,"The full-heavy tetraquarks $bb\bar{b}\bar{b}$ and $cc\bar{c}\bar{c}$ are
systematically investigated within the chiral quark model and the quark
delocalization color screening model. Two structures, meson-meson and
diquark-antidiquark, are considered. For the full-beauty $bb\bar{b}\bar{b}$
systems, there is no any bound state or resonance state in two structures in
the chiral quark model, while the wide resonances with masses around 19.25 GeV
and the quantum numbers $J^{P}=0^{+}$, $1^{+}$, and $2^{+}$ are possible in the
quark delocalization color screening model. For the full-charm
$cc\bar{c}\bar{c}$ systems, the results are qualitative consistent in two quark
models. No bound state can be found in the meson-meson configuration, while in
the diquark-antidiquark configuration there may exist the resonance states,
with masses range between $6.3$ GeV to $7.4$ GeV, and the quantum numbers
$J^{P}=0^{+}$, $1^{+}$, and $2^{+}$. And the separation between the diquark and
the antidiquark indicates that these states may be the compact resonance
states. All these full-charm resonance states are consistent with the latest
results at LHCb collaboration and are worth searching in the experiments
further.",2006.13745v1
2020-06-24,Thermal origin of light emission in non-resonant and resonant tunnel junctions,"Electron tunneling is associated with light emission. In order to elucidate
its generating mechanism, we provide a novel experimental ansatz that employs
fixed-distance epitaxial graphene as metallic electrodes. In contrast to
previous experiments, this permits an unobscured light spread from the tunnel
junction, enabling both a reliable calibration of the visible to infrared
emission spectrum and a detailed analysis of the dependence of the parameters
involved. In an open, non-resonant geometry, the emitted light is perfectly
characterized by a Planck spectrum. In an electromagnetically resonant
environment, resonant radiation is added to the thermal spectrum, both being
strictly proportional in intensity. In full agreement with a simple heat
conduction model, we provide evidence that in both cases the light emission
stems from a hot electronic subsystem in interaction with its linear
electromagnetic environment. These very clear results should resolve any
ambiguity about the mechanism of light emission in nano contacts.",2006.13854v1
2020-06-30,Light-flavor resonance dynamics in the $U(3)$ chiral theory,"We review the recent developments on the light-flavor resonances in the
$U(3)$ chiral effective filed theory. The spectral function sum rules and the
semilocal duality in the scattering, which will be focus of this note, can
provide us interesting and useful theoretical objects to bridge the hadron
resonances in the intermediate energy region and the QCD behaviors in the
asymptotic region. First the calculations of the meson-meson scattering
amplitudes and factor factors are elaborated. The scalar spectral functions are
then calculated in terms of the unitarized scalar form factors. The scalar and
pseudoscalar spectral function sum rules in our study are found to be
consistent with the asymptotic behavior of QCD in the chiral limit. The
semilocal duality is found to be generally well satisfied, indicating the
necessary cancellations of different contributions from different resonances
indeed happen in the scattering amplitudes. The $N_C$ evolutions of the
resonance poles, the ratios to quantify the semilocal duality and the spectral
function integrals are also paid special attention to in this note.",2006.16855v1
2020-08-10,The non-resonance shake mechanism of the neutrinoless double electronic capture,"It is generally accepted that double neutrinoless electron capture is a
resonance process. The calculations of the probability of shaking with the
ionization of the electron shell occurring during the transformation of 152Gd
and 164Er nuclei are performed below. These nuclides have the lowest resonance
defect among all known nuclei, being considered as main candidates for
discovering the neutrinoless mode of the transformation. The results show
predominant contribution of the new mechanism for most of the candidate nuclei.
The value of this amendment rapidly increases with an increasing resonance
defect. Thus, in principle, double neutrinoless electron capture appears not to
be a resonance process at all.",2008.03906v1
2020-08-19,Resonant Self-Interacting Dark Matter from Dark QCD,"We present models of resonant self-interacting dark matter in a dark sector
with QCD, based on analogies to the meson spectra in Standard Model QCD. For
dark mesons made of two light quarks, we present a simple model that realizes
resonant self-interaction (analogous to the $\phi$-K-K system) and thermal
freeze-out. We also consider asymmetric dark matter composed of heavy and light
dark quarks to realize a resonant self-interaction (analogous to the
$\Upsilon(4S)$-B-B system) and discuss the experimental probes of both setups.
Finally, we comment on the possible resonant self-interactions already built
into SIMP and ELDER mechanisms while making use of lattice results to determine
feasibility.",2008.08608v1
2020-08-24,The Universality of the Resonance Arrangement and its Betti Numbers,"The resonance arrangement $\mathcal{A}_n$ is the arrangement of hyperplanes
which has all non-zero $0/1$-vectors in $\mathbb{R}^n$ as normal vectors. It is
the adjoint of the Braid arrangement and is also called the all-subsets
arrangement. The first result of this article shows that any rational
hyperplane arrangement is the minor of some large enough resonance arrangement.
  Its chambers appear as regions of polynomiality in algebraic geometry, as
generalized retarded functions in mathematical physics and as maximal
unbalanced families that have applications in economics. One way to compute the
number of chambers of any real arrangement is through the coefficients of its
characteristic polynomial which are called Betti numbers. We show that the
Betti numbers of the resonance arrangement are determined by a fixed
combination of Stirling numbers of the second kind. Lastly, we develop exact
formulas for the first two non-trivial Betti numbers of the resonance
arrangement.",2008.10553v2
2020-09-11,Optical repumping of resonantly excited quantum emitters in hexagonal boron nitride,"Resonant excitation of solid-state quantum emitters enables coherent control
of quantum states and generation of coherent single photons, which are required
for scalable quantum photonics applications. However, these systems can often
decay to one or more intermediate dark states or spectrally jump, resulting in
the lack of photons on resonance. Here, we present an optical co-excitation
scheme which uses a weak non-resonant laser to reduce transitions to a dark
state and amplify the photoluminescence from quantum emitters in hexagonal
boron nitride (hBN). Utilizing a two-laser repumping scheme, we achieve
optically stable resonance fluorescence of hBN emitters and an overall increase
of ON time by an order of magnitude compared to only resonant excitation. Our
results are important for the deployment of atom-like defects in hBN as
reliable building blocks for quantum photonic applications.",2009.05323v1
2020-09-13,Nature of $\bm{S}$-wave $\bm{NN}$ interaction and dibaryon production at nucleonic resonance thresholds,"Phase shifts and inelasticity parameters for $NN$ scattering in the
partial-wave channels ${}^3S_1$--${}^3D_1$ and ${}^1S_0$ at energies $T_{\rm
lab}$ from zero to about 1 GeV are described within a unified $NN$ potential
model assuming the formation of isoscalar and isovector dibaryon resonances
near the $NN^*(1440)$ threshold. Evidence for these near-threshold resonances
is actually found in the recent WASA experiments on single- and double-pion
production in $NN$ collisions. There, the excitation of the Roper resonance
$N^*(1440)$ exhibits a structure in the energy dependence of the total cross
section, which corresponds to the formation of dibaryon states with
$I(J^\pi)=0(1^+)$ and $1(0^+)$ at the $NN^*(1440)$ threshold. These two
$S$-wave dibaryon resonances may provide a new insight into the nature of the
strong $NN$ interaction at low and intermediate energies.",2009.05941v1
2020-09-14,A study of vowel nasalization using instantaneous spectra,"Nasalization of vowels is a phenomenon where oral and nasal tracts
participate simultaneously for the production of speech. Acoustic coupling of
oral and nasal tracts results in a complex production system, which is
subjected to a continuous changes owing to glottal activity. Identification of
the duration of nasalization in vowels, and the extent of coupling of oral and
nasal tracts, is a challenging task. The present research focuses on the
changes in instantaneous vocal tract system response to study the effects of
co--articulatory load of nasals on vowels. The dominant resonance frequency
(DRF) contour derived from the spectra illustrates the contribution of oral and
nasal resonances during nasalization. The extent of coupling determines the
dominance of these resonances during glottal open and closed phases. A higher
extent leads to more decay of energy for the oral resonances, and hence the
vowel spectra exhibits a dominant nasal resonance. A comparison of the proposed
parameters is made with the previously suggested measures. Several examples of
segments of vowels in the context of nasal consonants for English language for
both male and female speakers of English are used to illustrate different
aspects of the proposed analysis method.",2009.06416v1
2020-09-16,Frequency-domain model of optical frequency-comb generation in optical resonators with second- and third-order nonlinearities,"We developed a frequency-domain model describing optical frequency-comb
generation in optical resonators with second- and third-order nonlinearities.
Compared with time-domain models, our model in principle allows one to express
the cavity dispersion accurately, avoiding the dispersion being truncated
beyond a certain order. Moreover, the frequency-domain model can readily
include frequency dependence of system parameters, such as the linear
absorption and the cavity coupling ratio. To demonstrate the validity of our
model, we numerically simulated quadratic combs in a singly resonant
second-harmonic generation cavity and Kerr combs in a micro-resonator as two
examples. The simulated results obtained from the frequency-domain model agree
well with those given by previous time-domain models. A system containing both
second- and third-order nonlinearities can give rise to many novel physical
dynamics. The developed frequency-domain model will contribute to understanding
optical frequency-comb generation assisted by multi-order nonlinear processes
in various optical resonators.",2009.07603v1
2020-09-28,Metasurface Reflector with Real-Time Independent Magnitude and Phase Control,"A novel metasurface unit cell architecture is proposed to enable independent
control of the reflection magnitude and phase at a desired operation frequency,
while maintaining linear polarization of the incoming fields. The proposed
structure is based on a coupled-resonator configuration where a Dipole Ring
Resonator (DRR) is loaded with a tunable lumped resistive element (e.g. PIN
diode) and Split Ring Resonator (SRR) loaded with a lumped tunable capacitor
(e.g. varactor diode), are interleaved. The surface is next operated around one
of the coupled resonant frequency, where an independent tuning of the lumped
capacitance and resistance elements enable a wide coverage of reflection
amplitude-phase, which is significantly larger than what would have been
achievable using a single resonator configuration. An insightful equivalent
circuit model is further developed for investigating the amplitude-phase
characteristics of a uniform surface as a function of variable resistance and
capacitance, which is next confirmed using full-wave simulations. Finally,
using a variety of full-wave examples, the usefulness of simultaneous and
independent amplitude-phase control is demonstrated, including cases of
variable pattern gain with beam tilting and multi-beam pattern realization,
which otherwise would not be possible using either amplitude or phase control
only.",2009.13369v1
2020-10-03,Tunable Fiber Fabry-Perot Cavities with High Passive Stability,"We present three high finesse tunable monolithic fiber Fabry-Perot cavities
(FFPCs) with high passive mechanical stability. The fiber mirrors are fixed
inside slotted glass ferrules, which guarantee an inherent alignment of the
resonators. An attached piezoelectric element enables fast tuning of the FFPC
resonance frequency over the entire free-spectral range for two of the designs.
Stable locking of the cavity resonance is achieved for feedback bandwidths as
low as $20\,$mHz, demonstrating the high passive stability. At the other limit,
locking bandwidths up to $27\,$kHz, close to the first mechanical resonance,
can be obtained. The root-mean-square frequency fluctuations are suppressed
down to $\sim 2\,$% of the cavity linewidth. Over a wide frequency range, the
frequency noise is dominated by the thermal noise limit of the system's
mechanical resonances. The demonstrated small footprint devices can be used
advantageously in a broad range of applications like cavity-based sensing
techniques, optical filters or quantum light-matter interfaces.",2010.02204v1
2020-10-05,The Resonance Hopping Effect in the Neptune-Planet Nine System,"The observed physical clustering of the orbits of small bodies in the distant
Kuiper Belt (TNOs) has recently prompted the prediction of an additional planet
in the outer solar system. Since the initial posing of the hypothesis, the
effects of Planet Nine on the dynamics of the main cluster of TNOs - the
objects anti-aligned with its orbit - have been well-studied. In particular,
numerical simulations have revealed a fascinating phenomenon, referred to as
""resonance hopping"", in which these objects abruptly transition between
different mean-motion commensurabilities with Planet Nine. In this work, we
explore this effect in greater detail, with the goal of understanding what
mechanism prompts the hopping events to occur. In the process, we elucidate the
often underestimated role of Neptune scattering interactions, which leads to
diffusion in the semi-major axes of these distant TNOs. In addition, we
demonstrate that although some resonant interactions with Planet Nine do occur,
the anti-aligned objects are able to survive without the resonances, confirming
that the dynamics of the TNOs are predominantly driven by secular, rather than
resonant, interactions with Planet Nine.",2010.02234v1
2020-10-09,Understanding Fundamental Tradeoffs in Nanomechanical Resonant Sensors,"Nanomechanical resonators are used as high performance detectors in a variety
of applications such as mass spectrometry and atomic force microscopy. Initial
emphasis in nanomechanical resonant sensor research was on increasing the
sensitivity to the level of a single molecule, atom and beyond. On the other
hand, there are applications where the speed of detection is crucial, prompting
recent works that emphasize sensing schemes with improved time resolution. We
first develop a general modeling framework encompassing all resonator tracking
schemes currently in use, by extending recent previous work. We then explore
the fundamental trade-offs between accuracy and speed in three resonant sensor
architectures, namely the feedback-free open-loop approach, positive-feedback
based self-sustaining oscillator, and negative-feedback based frequency-locked
loop scheme. We comparatively analyze them in a unified manner, clarify some
misconceptions that seem to exist in the literature, and unravel their speed
versus accuracy characteristics.",2010.04447v1
2020-10-12,An Investigation On Neck Extensions For Single and Multi-Degree Of Freedom Acoustic Helmholtz Resonators,"The effect of neck extensions in single and multi-degree of freedom Helmholtz
resonator based acoustic liners is studied both experimentally and numerically
and the resulting transmission coefficient and resonance frequencies are
examined. It has been shown that a single degree of freedom liner with
increasing neck extension lengths leads to the resonance frequencies being
pushed to lower frequency values, however, this shift to lower frequencies is
not linear with increasing length. A study on including neck extensions for the
primary and/or secondary neck within a double degree of freedom liner is also
presented. It is shown that both neck extension concepts lead to an increase in
bandwidth of sound absorption by a double degree of freedom Helmholtz
resonator.",2010.05908v1
2020-10-23,Resonances in hyperbolic dynamics,"The study of wave propagation outside bounded obstacles uncovers the
existence of resonances for the Laplace operator, which are complex-valued
generalized eigenvalues, relevant to estimate the long time asymptotics of the
wave. In order to understand distribution of these resonances at high
frequency, we employ semiclassical tools, which leads to considering the
classical scattering problem, and in particular the set of trapped
trajectories. We focus on ""chaotic"" situations, where this set is a hyperbolic
repeller, generally with a fractal geometry. In this context, we derive fractal
Weyl upper bounds for the resonance counting; we also obtain dynamical criteria
ensuring the presence of a resonance gap. We also address situations where the
trapped set is a normally hyperbolic submanifold, a case which can help
analyzing the long time properties of (classical) Anosov contact flows through
semiclassical methods.",2010.12385v1
2020-10-31,Interference traps waves in open system: Bound states in the continuum,"I review the four mechanisms of bound states in the continuum (BICs) in
application to microwave and acoustic cavities open to directional waveguides.
The most simple are the symmetry protected BICs which are localized inside the
cavity because of the orthogonality of the eigenmodes to the propagating modes
of waveguides. However, the most general and interesting is the
Friedrich-Wintgen mechanism when the BICs are result of full destructive
interference of outgoing resonant modes. The third type of the BICs, the
Fabry-Perot BICs, occur in a double resonator system when each resonator can
serve as an ideal mirror. At last, the accidental BICs can be realized in the
open cavities with no symmetry like the open Sinai billiard in which the
eigenmode of the resonator can become orthogonal to the continuum of the
waveguide accidentally by a smooth deformation of the eigenmode. We also review
the one-dimensional systems in which the BICs occur owing to full destructive
interference of two waves separated by spin or polarization or by paths in the
Aharonov-Bohm rings. We widely use the method of effective non-Hermitian
Hamiltonian equivalent to the coupled mode theory which detects bound states in
the continuum (BICs) by finding zero widths resonances.",2011.01221v1
2020-11-06,Design of ultra-high gain optical micro-amplifiers via smart non-linear wave mixing,"Optical amplification of the input wave by mixing the pump wave within a
nonlinear interaction medium offers high gain for a variety of applications. In
real life studies, the interaction mediums which allow the optical
amplification of the input wave have many resonance frequencies. However, the
computational expense for tuning the pump frequency to yield the optical
amplification of the input wave increases with the number of resonance
frequencies within the interaction mediums. Here, we present a Fletcher-Reeves
based algorithm for parametric amplification in micro-resonators having
multiple resonance frequencies. Using our novel mathematical formulations, we
obtained a gain of 4.7x107 for the input wave at 640 THz and a gain of 1.5x108
for the input wave at 100 THz within the micro-resonators. Moreover, the
performance of our algorithm is verified by the well know mathematical
expression, and we achieved more than 99% accuracy in computation of optical
amplification. To our knowledge, this is the first study where Fletcher-Reeves
algorithm is used for the parametric amplification. Our methodology can be
accompanied to design optical parametric amplifiers for applications of
high-speed optical communications, photonic circuits, and ultrafast lasers.",2011.03592v1
2020-11-10,Dark-modes excitation in coupled nano Fabry-Perot structure induced by symmetry breaking,"Absorbing metamaterials have attracted a widespread interest but suffer from
the metallic ohmic losses that limits their Q-factor to values around 10. In
this paper, we report the engineering and experimental characterization of a
high Q dark-mode in a metasurface resulting from the coupling of several
individual nano-Fabry-Perot structures supporting low-contrast resonances. The
resulting resonance has a Q-factor above 20 and a nearly total absorption.
Moreover, we also demonstrate that several dark-mode resonances can be excited
simultaneously, by exploiting the coupling of various pairs of nano Fabry-Perot
resonators within the same subwavelength period. Finally, the resonance's
Q-factor depends monotonously on the thickness of the metasurface and can reach
values up to 85.",2011.05242v1
2020-11-18,Ground-state cooling of mechanical resonators by quantum reservoir engineering,"We propose a scheme to cool down a mechanical resonator to its quantum
ground-state, which is interacting with a working fluid via an
optomechanical-like coupling. As opposed to standard laser cooling schemes
where coherence renders the motion of a resonator to its ground-state, we
consider an incoherent thermal source to achieve the same aim. We show that
simultaneous cooling of two degenerate or near-degenerate mechanical resonators
is possible, which is otherwise a challenging goal to achieve. The
generalization of this method to the simultaneous cooling of multiple
resonators is straightforward. Spectral filtering of the coupling between the
cooling agent and the baths is a key to realize cooling in our scheme. The
underlying physical mechanism of cooling is explained by investigating a direct
connection between the laser sideband cooling and cooling by heating in a
standard optomechanical setting. Our advantageous scheme of cooling enabled by
quantum reservoir engineering can be realized in various setups, employing
parametric coupling of a cooling agent with the target systems. We also discuss
using non-thermal baths to simulate ultra-high temperature thermal baths for
cooling.",2011.09518v2
2021-02-04,Dissipative stabilization of squeezing beyond 3 dB in a microwave mode,"While a propagating state of light can be generated with arbitrary squeezing
by pumping a parametric resonator, the intra-resonator state is limited to 3 dB
of squeezing. Here, we implement a reservoir engineering method to surpass this
limit using superconducting circuits. Two-tone pumping of a three-wave-mixing
element implements an effective coupling to a squeezed bath which stabilizes a
squeezed state inside the resonator. Using an ancillary superconducting qubit
as a probe allows us to perform a direct Wigner tomography of the
intra-resonator state. The raw measurement provides a lower bound on the
squeezing at about $6.7 \pm 0.2$ dB below the zero-point level. Further, we
show how to correct for resonator evolution during the Wigner tomography and
obtain a squeezing as high as $8.2 \pm 0.8$ dB. Moreover, this level of
squeezing is achieved with a purity of $-0.4 \pm 0.4$ dB.",2102.02863v2
2021-02-10,Large-scale GHZ states through topologically protected zero-energy mode in a superconducting qutrit-resonator chain,"We propose a superconducting qutrit-resonator chain model, and analytically
work out forms of its topological edge states. The existence of the zero-energy
mode enables to generate a state transfer between two ends of the chain,
accompanied with state flips of all intermediate qutrits, based on which
$N$-body Greenberger-Horne-Zeilinger (GHZ) states can be generated with great
robustness against disorders of coupling strengths. Three schemes of generating
large-scale GHZ states are designed, each of which possesses the robustness
against loss of qutrits or of resonators, meeting a certain performance
requirement of different experimental devices. With experimentally feasible
qutrit-resonator coupling strengths and available coherence times of qutrits
and resonators, it has a potential to generate large-scale GHZ states among
dozens of qutrits with a high fidelity. Further, we show the experimental
consideration of generating GHZ states based on the circuit QED system, and
discuss the prospect of realizing fast GHZ states.",2102.05327v1
2021-02-14,Attention-gated convolutional neural networks for off-resonance correction of spiral real-time MRI,"Spiral acquisitions are preferred in real-time MRI because of their
efficiency, which has made it possible to capture vocal tract dynamics during
natural speech. A fundamental limitation of spirals is blurring and signal loss
due to off-resonance, which degrades image quality at air-tissue boundaries.
Here, we present a new CNN-based off-resonance correction method that
incorporates an attention-gate mechanism. This leverages spatial and channel
relationships of filtered outputs and improves the expressiveness of the
networks. We demonstrate improved performance with the attention-gate, on 1.5
Tesla spiral speech RT-MRI, compared to existing off-resonance correction
methods.",2102.07271v1
2021-02-16,Microwave-resonator-detected excited-state spectroscopy of a double quantum dot,"As an application in circuit quantum electrodynamics (cQED) coupled systems,
superconducting resonators play an important role in high-sensitivity
measurements in a superconductingsemiconductor hybrid architecture. Taking
advantage of a high-impedance NbTiN resonator, we perform excited-state
spectroscopy on a GaAs double quantum dot (DQD) by applying voltage pulses to
one gate electrode. The pulse train modulates the DQD energy detuning and gives
rise to charge state transitions at zero detuning. Benefiting from the
outstanding sensitivity of the resonator, we distinguish different spin-state
transitions in the energy spectrum according to the Pauli exclusion principle.
Furthermore, we experimentally study how the interdot tunneling rate modifies
the resonator response. The experimental results are consistent with the
simulated spectra based on our model.",2102.08169v1
2021-02-17,Space-time resonances and high-frequency Raman instabilities in the two-fluid Euler-Maxwell system,"We show that space-time resonances induce high-frequency Raman instabilities
in the two-fluid Euler-Maxwell system describing laser-plasma interactions. A
consequence is that the Zakharov WKB approximation to Euler-Maxwell is unstable
for non-zero group velocities. A key step in the proof is the reformulation of
the set of resonant frequencies as the locus of weak hyperbolicity for
linearized equations around the WKB solution. We analyze those linearized
equations with the symbolic flow method. Due to large transverse variations in
the WKB profile, the equation satisfied by the symbolic flow around resonant
frequencies is a linear {\it partial} differential equation. At space-time
resonances corresponding to Raman instabilities, we observe a fast growth of
the symbolic flow, which translates into an instability result for the original
system. The strongest instability is caused by backscattered Raman waves.",2102.08891v1
2021-02-26,A canonical transformation to eliminate resonant perturbations I,"We study dynamical systems which admit action-angle variables at leading
order which are subject to nearly resonant perturbations. If the frequencies
characterizing the unperturbed system are not in resonance, the long-term
dynamical evolution may be integrated by orbit-averaging over the
high-frequency angles, thereby evolving the orbit-averaged effect of the
perturbations. It is well known that such integrators may be constructed via a
canonical transformation, which eliminates the high frequency variables from
the orbit-averaged quantities. An example of this algorithm in celestial
mechanics is the von Zeipel transformation. However if the perturbations are
inside or close to a resonance, i.e. the frequencies of the unperturbed system
are commensurate, these canonical transformations are subject to divergences.
We introduce a canonical transformation which eliminates the high frequency
phase variables in the Hamiltonian without encountering divergences. This leads
to a well-behaved symplectic integrator. We demonstrate the algorithm through
two examples: a resonantly perturbed harmonic oscillator and the gravitational
three-body problem in mean motion resonance.",2103.00013v2
2021-03-08,Visible and Near-infrared Microdisk Resonators on a 4H-Silicon-Carbide-on-Insulator Platform,"Wavelength-sized microdisk resonators were fabricated on a single crystalline
4H-silicon-carbide-oninsulator platform (4H-SiCOI). By carrying out
microphotoluminescence measurements at room temperature, we show that the
microdisk resonators support whispering-gallery modes (WGMs) with quality
factors up to $5.25 \times 10^3$ and mode volumes down to $2.69 \times(\lambda
/n)^3$ at the visible and near-infrared wavelengths. Moreover, the demonstrated
wavelength-sized microdisk resonators exhibit WGMs whose resonant wavelengths
compatible with the zero-phonon lines of spin defects in 4H-SiCOI, making them
a promising candidate for applications in cavity quantum electrodynamics and
integrated quantum photonic circuits.",2103.04547v1
2021-03-08,Exterior Complex Scaling Approach for Atoms and Molecules in Strong DC Fields,"We perform a short review of the history of quantum mechanics, with a focus
on the historical problems with describing ionization theoretically in the
context of quantum mechanics. The essentials of the theory of resonances are
presented. The exterior complex scaling method for obtaining resonance
parameters within the context of the Schrodinger equation is detailed. We
explain how this is implemented for a numerical solution using a finite element
method for the scaled variable. Results for the resonance parameters of a
one-dimensional hydrogen model in an external direct current (DC) electric
field are presented as proof of the independence of the theory from the scaling
angle. We apply the theory to the real hydrogen atom in a DC field and present
results which agree with literature values. The resonance parameters for singly
ionized helium are also presented. Using a model potential energy for the water
molecule, we solve for the energy eigenvalues. We then solve for the resonance
parameters of the water molecule in a DC field and compare to literature
results. Our widths for the valence orbital are shown to agree well with the
so-called ""coupled-cluster singles and doubles with perturbative triples
excitations"" method.",2103.05058v1
2021-03-10,Modulated rotating waves and triadic resonances in spherical fluid systems: The case of magnetized spherical Couette flow,"The existence of triadic resonances in the magnetized spherical Couette
system (MSC) is related to the development of modulated rotating waves, which
are quasiperiodic flows understood in terms of bifurcation theory in systems
with symmetry. In contrast to previous studies in spherical geometry the
resonant modes are not inertial waves but related with the radial jet
instability which is strongly equatorially antisymmetric. We propose a general
framework in which triadic resonances are generated through successive Hopf
bifurcations from the base state. The study relies on an accurate frequency
analysis of different modes of the flow, for solutions belonging to two
different bifurcation scenarios. The azimuthal and latitudinal nonlinear
coupling among the resonant modes is analysed and interpreted using spherical
harmonics and the results are compared with previous studies in spherical
geometry.",2103.05924v1
2021-03-12,Effects of external flow on resonant absorption of coronal loop kink oscillations driven by an external fast wave: Selective excitation problem,"Resonant absorption is considered as a crucial mechanism for the damping of
the coronal loop oscillations and plasma heating. We study resonant absorption
of the coronal loop kink oscillations excited by such external drivers as
flares on the assumption that there is an intermediate shear flow region
surrounding the loop. We find that for long coronal loops resonant absorption
can be highly enhanced or reduced depending sensitively on the magnitude and
direction of the flow and the spatial extent of the flow region when the
transitional layer is thin. For short coronal loops, high flow speed and thick
transitional layer are needed to have a substantial resonant absorption. We
provide a potential picture to explain the results where the external
Alfv\'{e}n speed and phase speed of the wave are important parameters. These
results imply that the transport of the external wave energy into the loop is
significantly changed by the shear flow region, which may cause the selective
excitation of the coronal loop oscillations.",2103.07063v2
2021-03-12,Magnetic Feshbach resonances in collisions of $^{23}$Na$^{40}$K with $^{40}$K,"We present measurements of more than 80 magnetic Feshbach resonances in
collisions of ultracold $^{23}$Na$^{40}$K with $^{40}$K. We assign quantum
numbers to a group of low-field resonances and show that they are due to
long-range states of the triatomic complex in which the quantum numbers of the
separated atom and molecule are approximately preserved. The resonant states
are not members of chaotic bath of short-range states. Similar resonances are
expected to be a common feature of alkali-metal diatom + atom systems.",2103.07130v2
2021-03-13,Stochastic resonance in periodically driven bistable systems subjected to anomalous diffusion,"The occurrence of stochastic resonance in bistable systems undergoing
anomalous diffusions, which arise from density-dependent fluctuations, is
investigated with emphasis on the analytical formulation of the problem as well
as a possible analytical derivation of key quantifiers of stochastic resonance.
The nonlinear Fokker-Planck equation describing the system dynamics, together
with the corresponding Ito-Langevin equation, are formulated. In the
linear-response regime analytical expressions of the spectral amplification, of
the signal-to-noise ratio and of the hysteresis loop area are derived as
quantifiers of stochastic resonance. These quantifiers are found to be strongly
dependent on the parameters controlling the type of diffusion, in particular
the peak characterizing the signal-to-noise ratio occurs only in close ranges
of parameters. Results introduce the relevant information that taking into
consideration the interactions of anomalous diffusive systems with a periodic
signal, can provide a better understanding of the physics of stochastic
resonance in bistable systems driven by periodic forces.",2103.07723v1
2021-04-08,Parametric-resonance entangling gates with a tunable coupler,"High-fidelity parametric gates have been demonstrated with superconducting
qubits via rf flux modulation of the qubit frequency. The modulation however
leads to renormalization of the bare qubit-qubit coupling, thereby reducing the
gate speed. Here, we realize a parametric-resonance gate, which is activated by
bringing the average frequency of the modulated qubit in resonance with a
static-frequency qubit while approximately retaining the bare qubit-qubit
coupling. The activation of parametric-resonance gates does not depend on the
frequency of modulation, allowing us to choose the modulation frequencies and
avoid frequency collisions. Moreover, we show that this approach is compatible
with tunable coupler architectures, which reduce always-on residual couplings.
Using these techniques, we demonstrate iSWAP and CZ gates between two qubits
coupled via a tunable coupler with average process fidelities as high as
$99.3\%$ and $97.9\%$, respectively. The flexibility in activating
parametric-resonance gates combined with a tunable coupler architecture
provides a pathway for building large-scale quantum computers.",2104.03511v2
2021-04-10,Shape reconstructions by using plasmon resonances,"We study the shape reconstruction of an inclusion from the {faraway}
measurement of the associated electric field. This is an inverse problem of
practical importance in biomedical imaging and is known to be notoriously
ill-posed. By incorporating Drude's model of the permittivity parameter, we
propose a novel reconstruction scheme by using the plasmon resonance with a
significantly enhanced resonant field. We conduct a delicate sensitivity
analysis to establish a sharp relationship between the sensitivity of the
reconstruction and the plasmon resonance. It is shown that when plasmon
resonance occurs, the sensitivity functional blows up and hence ensures a more
robust and effective construction. Then we combine the Tikhonov regularization
with the Laplace approximation to solve the inverse problem, which is an
organic hybridization of the deterministic and stochastic methods and can
quickly calculate the minimizer while capture the uncertainty of the solution.
We conduct extensive numerical experiments to illustrate the promising features
of the proposed reconstruction scheme.",2104.04796v3
2021-04-10,Free and forced vibrations of damped locally-resonant sandwich beams,"This paper addresses the dynamics of locally-resonant sandwich beams, where
multi-degree-of-freedom viscously-damped resonators are periodically
distributed within the core matrix. Using an equivalent single-layer Timoshenko
beam model coupled with mass-spring-dashpot subsystems representing the
resonators, two solution methods are presented. The first is a direct
integration method providing the exact frequency response under arbitrary
loads. The second is a complex modal analysis approach obtaining exact modal
impulse and frequency response functions, upon deriving appropriate
orthogonality conditions for the complex modes. The challenging issue of
calculating all eigenvalues, without missing anyone, is solved applying a
recently-introduced contour-integral algorithm to a characteristic equation
built as determinant of an exact frequency-response matrix, whose size is $4
\times 4$ regardless of the number of resonators. Numerical applications prove
exactness and robustness of the proposed solutions.",2104.04870v1
2021-04-14,High-Q silicon nitride drum resonators strongly coupled to gates,"Silicon nitride (SiN) mechanical resonators with high quality mechanical
properties are attractive for fundamental research and applications. However,
it is challenging to maintain these mechanical properties while achieving
strong coupling to an electrical circuit for efficient on-chip integration.
Here, we present a SiN drum resonator covered with an aluminum thin film,
enabling large capacitive coupling to a suspended top-gate. Implementing the
full electrical measurement scheme, we demonstrate a high quality factor ~ 1E4
(comparable to that of bare drums at room temperature) and present our ability
to detect ? 10 mechanical modes at low temperature. The drum resonator is also
coupled to a microwave cavity, so that we can perform optomechanical sideband
pumping with a fairly good coupling strength G and demonstrate mechanical
parametric amplification. This SiN drum resonator design provides efficient
electrical integration and exhibits promising features for exploring mode
coupling and signal processing.",2104.07142v2
2021-04-23,Inclination-type resonance in two-planet systems,"We investigate the inclination-growth mechanisms for two-planet systems
during the late protoplanetary disc phase. In previous works, much attention
has been directed to the inclination-type resonance, and it has been shown that
it asks for high eccentricities to be acquired during the migration of the
giant planets. By adopting eccentricity and inclination damping formulae based
on hydrodynamical simulations (instead of the K-prescription), we have carried
out 20 000 numerical simulations, where we vary the initial planetary
eccentricities, the migration rate, and the dispersal time of the gas disc. Our
results confirm that highly mutually inclined systems are unlikely to be
produced by an inclination-type resonance of two migrating giant planets.
However, in ~1 per cent of the simulations, inclination-type resonance is
observed, and a dynamical study of the evolutions reveals that the
inclination-type resonance mechanism operates in three cases: (i) when the
inner planet reaches the inner cavity of the disc, (ii) at moderate to high
eccentricities for faster migration rates, and (iii) at low to moderate
eccentricities after a phase of orbital destabilization and re-arrangement.",2104.11611v1
2021-04-25,Multiphoton resonance in a driven Kerr oscillator in presence of high-order nonlinearities,"We considered the multiphoton resonance in the periodically driven quantum
oscillator with Kerr nonlinearity in the presence of weak high-order
nonlinearities. Multiphoton resonance leads to the emergence of peaks and dips
in the dependence of the stationary occupations of the stable states on
detuning. We demonstrated that due to high-order nonlinearities, these peaks
and dips acquire additional fine structure and split into several closely
spaced ones. Quasiclassically, multiphoton resonance is treated as tunneling
between the regions of the oscillator phase portrait, and the fine structure of
the multiphoton resonance is a consequence of a special quasienergy dependence
of the tunneling rate between different regions of the classical phase
portrait. For different values of damping and high-order nonlinearity
coefficients, we identified the domain of quasienergies where tunneling
strongly influences the system kinetics. The corresponding tunneling term in
the Fokker-Planck equation in quasienergy space was derived directly from the
quantum master equation.",2104.12140v2
2021-04-26,Pion couplings with low-lying nucleon resonances,"We have calculated coupling constants of a neutral pion with the lowest two
nucleon resonances. This includes both the diagonal as well as non-diagonal
coupling constants involving a nucleon resonance and a nucleon. For this, we
first calculate vacuum-to-pion correlation function of the interpolating fields
of two nucleons and then take its matrix elements with respect to a nucleon
spinor and/or a nucleon resonance spinor(s). Using different QCD sum rules
obtained from different matrix elements we eliminate unwanted coupling
constants and solve for the desired ones. This is a simple extension of the
projected correlation function approach used in the literature where we use
multiple of states involving those of a nucleon and its resonances. We have
also checked the stability of our results with respect to variation of
different QCD and phenomenological input parameters.",2104.12371v2
2021-04-28,Perturbation theory of nearly spherical dielectric optical resonators,"Dielectric spheres of various sizes may sustain electromagnetic
whispering-gallery modes resonating at optical frequencies with very narrow
linewidths. Arbitrary small deviations from the spherical shape typically shift
and broaden such resonances. Our goal is to determine these shifted and
broadened resonances. A boundary-condition perturbation theory for the acoustic
vibrations of nearly circular membranes was developed by Rayleigh more than a
century ago. We extend this theory to describe the electromagnetic excitations
of nearly spherical dielectric cavities. This approach permits us to avoid
dealing with decaying quasinormal modes. We explicitly find the frequencies and
the linewidths of the optical resonances for arbitrarily deformed nearly
spherical dielectric cavities, as power series expansions by a small parameter,
up to and including second-order terms. We thoroughly discuss the physical
conditions for the applicability of perturbation theory.",2104.13783v3
2021-04-29,Bulk-Sensitive Spin-Resolved Resonant Electron Energy-Loss Spectroscopy (SR-rEELS): Observation of Element- and Spin-Selective Bulk Plasmons,"We have developed a spin-resolved resonant electron energy-loss spectroscopy
(SR-rEELS) in the primary energy of 0.3--1.5 keV, which corresponds to the core
excitations of $2p$-$3d$ absorption of transition metals and $3d$-$4f$
absorption of rare-earths, with the energy resolution of about 100~meV using a
spin-polarized electron source as a GaAs/GaAsP strained superlattice
photocathode. Element- and spin-selective carrier and valence plasmons can be
observed using the resonance enhancement of core absorptions and electron spin
polarization. Furthermore, bulk-sensitive EELS spectra can be obtained because
the primary energy corresponds to the mean free path of 1--10~nm. The
methodology is expected to provide us novel information of elementary
excitations by resonant inelastic x-ray scattering and resonant photoelectron
spectroscopy.",2104.14262v2
2021-04-29,Metallic nanostructures as electronic billiards for nonlinear terahertz photonics,"Optical properties of metallic nanoparticles are most often considered in
terms of plasmons, the coupled states of light and quasi-free electrons. Here
we predict that confinement of electrons inside the nanostructure leads to
another, very different, type of resonance, which determines the optical
properties in the frequency range significantly below the plasmonic resonance.
We demonstrate that closely placed confinement-induces resonances typically
join into a single composite ""super-resonance"" which produces giant
nonlinearity at low frequencies. Our simulations show how such nonlinearities
can be used for efficient down-conversion of optical pump to terahertz and
mid-infrared frequencies in sub-micrometer devices based on nanoparticle
composites. We discuss the interaction of these quantum-confinement-induced
resonances with the conventional plasmonic ones, as well as the unusual quantum
level statistics, adapting here the paradigms of the electronic billiard
theory.",2104.14637v3
2021-05-03,Acoustic passive cloaking using thin outer resonators,"We consider the propagation of acoustic waves in a 2D waveguide unbounded in
one direction and containing a compact obstacle. The wavenumber is fixed so
that only one mode can propagate. The goal of this work is to propose a method
to cloak the obstacle. More precisely, we add to the geometry thin outer
resonators of width $\varepsilon$ and we explain how to choose their positions
as well as their lengths to get a transmission coefficient approximately equal
to one as if there were no obstacle. In the process we also investigate several
related problems. In particular, we explain how to get zero transmission and
how to design phase shifters. The approach is based on asymptotic analysis in
presence of thin resonators. An essential point is that we work around
resonance lengths of the resonators. This allows us to obtain effects of order
one with geometrical perturbations of width $\varepsilon$. Various numerical
experiments illustrate the theory.",2105.00922v1
2021-05-04,Phase-Dependence of Resonant and Antiresonant Two-Photon Excitations,"Measurements of the phase of two-photon matrix elements are presented for
resonant and antiresonant two-color ionization of helium. A tunable,
narrow-bandwidth, near-infrared (NIR) laser source is used for extreme
ultra-violet (XUV) high-harmonic generation (HHG). The 15th harmonic of the
laser is used within (1+1') XUV+NIR two-photon ionization, and tuned in and out
of resonance with members of the 1s$n$p $^1$P$_1$ ($n=3,4,5$) Rydberg series,
covering a broad spectral range with high spectral resolution. The technique
allows to observe characteristic rapid changes in the phase of the two-photon
matrix elements around the resonances and, previously unobserved, at the
antiresonances between the resonances. Similar effects are observed for (1+2')
XUV+NIR three-photon ionization. The experimental results are compared to a
perturbative model and to numerical solutions of the time-dependent
Schr\""odinger equation (TDSE) in the single active electron (SAE)
approximation, elucidating the origin and dependences of the observed
phenomena.",2105.01598v2
2021-05-12,On application of stochastic differential equations for simulation of nonlinear wave-particle resonant interactions,"Long-term simulations of energetic electron fluxes in many space plasma
systems require accounting for two groups of processes with well separated
time-scales: microphysics of electron resonant scattering by electromagnetic
waves and electron adiabatic heating/transport by mesoscale plasma flows.
Examples of such systems are Earth's radiation belts and Earth's bow shock,
where ion-scale plasma injections and cross-shock electric fields determine the
general electron energization, whereas electron scattering by waves relax
anisotropy of electron distributions and produces small populations of
high-energy electrons. The applicability of stochastic differential equations
is a promising approach for including effects of resonant wave-particle
interaction into codes of electron tracing in global models. This study is
devoted to test of such equations for systems with nondiffusive wave-particle
interactions, i.e. systems with nonlinear effects of phase trapping and
bunching. We consider electron resonances with intense electrostatic
whistler-mode waves often observed in the Earth's radiation belts. We
demonstrate that nonlinear resonant effects can be described by stochastic
differential equations with the non-Gaussian probability distribution of random
variations of electron energies.",2105.05819v1
2021-05-16,Resonance production in PbPb collisions at 5.02 TeV via hydrodynamics and hadronic afterburner,"Using a relativistic hydrodynamics + hadronic afterburner simulation we
explore resonance production in PbPb collisions at 5.02 TeV, and demonstrate
that many resonance yields, mean transverse momenta, and flows are very
sensitive to the late stage hadronic rescattering. Out of all measured
resonances $\Lambda(1520)$ is affected strongest by the hadronic rescattering
stage, which allows to estimate its duration, and even constrain branching
ratios of $\Sigma^* \to \Lambda(1520)\pi$ decays. Strong suppression of
$\Lambda(1520)$, which in vacuum has a lifetime of 12.6 fm/$c$, is explained by
its small lifetime in a hadronic medium, between 1 and 2 fm/$c$ at temperatures
between 100 and 150 MeV. We find that some resonances like $\Delta(1232)$,
$f_0(980)$, $a_0(980)$, $\Lambda(1405)$ are enhanced rather than suppressed by
the afterburner.",2105.07539v1
2021-05-26,Diamagnetically levitating resonant weighing scale,"Diamagnetic levitation offers stable confinement of an object from its
environment at zero power, and thus is a promising technique for developing
next generation unclamped resonant sensors. In this work, we realize a resonant
weighing scale using a graphite plate that is diamagnetically levitating over a
checkerboard arrangement of permanent magnets. We characterize the bending
vibrations of the levitating object using laser Doppler vibrometry and use
microgram glass beads to calibrate the responsivity of the sensor's resonance
frequency to mass changes. The sensor is used for real-time measurement of the
evaporation rate of nano-litre droplets with high-accuracy. By analyzing the
resonator's frequency stability, we show that the millimeter graphite sensor
can reach mass resolutions down to 4.0ng, relevant to biological and chemical
sensing concepts.",2105.12444v2
2021-05-27,Close-coupled model of Feshbach resonances in ultracold $^3$He* and $^4$He* atomic Collisions,"Helium atoms in the metastable $2^3{S_{1}}$ state (He$^*$) have unique
advantages for ultracold atomic experiments. However, there is no known
accessible Feshbach resonance in He$^*$, which could be used to manipulate the
scattering length and hence unlock several new experimental possiblities.
Previous experimental and theoretical studies for He$^*$ have produced
contradictory results. We aimed to resolve this discrepancy with a theoretical
search for Feshbach resonances, using a new close-coupled model of He$^*$
collisions in the presence of an external magnetic field. Several resonances
were detected and the existing literature discrepancy was resolved. Although
none of the resonances identified are readily experimentally useable, an
interesting non-Feshbach scattering length variation with magnetic field was
observed in heteronuclear collisions, at field strengths that are
experimentally accessible.",2105.12940v1
2021-06-04,Inherent Non-Linear Damping in Resonators with Inertia Amplification,"Inertia amplification is a mechanism coupling degrees of freedom within a
vibrating structure. Its goal is to achieve an apparent high dynamic mass and,
accordingly, a low resonance frequency. Such structures have been described for
use in locally resonant metamaterials and phononic crystals to lower the
starting frequency of a band gap without adding mass to the system. This study
shows that any non-linear kinematic coupling between translational or
rotational vibrations leads to the appearance of amplitude-dependent damping.
The analytical derivation of the equation of motion of a resonator with inertia
amplification creates insight in the damping process, and shows that the
vibration damping increases with its amplitude. The theoretical study is
validated by experimental evidence from two types of inertia-amplification
resonators. Finally, the importance of amplitude-dependent damping is
illustrated when the structure is used as a tuned mass damper for a cantilever
beam.",2106.02576v2
2021-06-10,Density functional study of the variants of inter-Coulombic decay resonances in the photoionization of Cl@C60,"Inter-Coulombic decay (ICD) resonances in the photoionization of Cl@C60
endofullerene molecule are calculated using a perturbative density functional
theory (DFT) method. This is the first ICD study of an open shell atom in a
fullerene cage. Three classes of resonances are probed: (i) Cl inner vacancies
decaying through C60 outer continua, (ii) C60 inner vacancies decaying through
Cl outer continua, and (iii) inner vacancies of either system decaying through
the continua of Cl-C60 hybrid levels, the hybrid Auger-ICD resonances.
Comparisons with Ar@C60 results reveal that the properties of hybrid Auger-ICD
resonances are affected by the extent of level hybridization.",2106.06071v1
2021-06-11,Self-induced entanglement resonance in a disordered Bose-Fermi mixture,"Different regimes of entanglement growth under measurement have been
demonstrated for quantum many-body systems, with an entangling phase for low
measurement rates and a disentangling phase for high rates (quantum Zeno
effect). Here we study entanglement growth on a disordered Bose-Fermi mixture
with the bosons playing the role of the effective self-induced measurement for
the fermions. Due to the interplay between the disorder and a non-Abelian
symmetry, the model features an entanglement growth resonance when the
boson-fermion interaction strength is varied. With the addition of a magnetic
field, the model acquires a dynamical symmetry leading to experimentally
measurable long-time local oscillations. At the entanglement growth resonance,
we demonstrate the emergence of the cleanest oscillations. Furthermore, we show
that this resonance is distinct from both noise enhanced transport and a
standard stochastic resonance. Our work paves the way for experimental
realizations of self-induced correlated phases in multi-species systems.",2106.06277v1
2021-06-11,"A hidden, heavier resonance of the Higgs field","In Veltman's original view, the Standard Model with a large Higgs particle
mass of about 1 TeV was the natural completion of non-renormalizable Glashow
model. This mass was thus a second threshold for weak interactions, as the W
mass was for the non-renormalizable 4-fermion V-A theory. Today, after the
observation of the narrow scalar resonance at 125 GeV, Veltman's large-mass
idea seems to be ruled out. Yet, this is not necessarily true. Depending on the
description of SSB in $\Phi^4$ theory, and by combining analytic calculations
and lattice simulations, besides the known particle at 125 GeV, a new resonance
of the Higgs field may also show up around 700 GeV. The peculiarity, though, is
that this heavier state would couple to longitudinal vector bosons with the
same typical strength of the low-mass state and thus represent a relatively
narrow resonance. In this way, such hypothetical new resonance would naturally
fit with some excess of 4-lepton events observed by ATLAS around 680 GeV.
Analogous data from CMS are needed to confirm or disprove this interpretation.
Implications of a two-mass structure for radiative corrections are also
discussed.",2106.06543v1
2021-06-16,Giant Enhancement of Unconventional Photon Blockade in a Dimer Chain,"Unconventional photon blockade refers to the suppression of multi-photon
states in weakly nonlinear optical resonators via the destructive interference
of different excitation pathways. It has been studied in a pair of coupled
nonlinear resonators and other few-mode systems. Here, we show that
unconventional photon blockade can be greatly enhanced in a chain of coupled
resonators. Specifically, the strength of the nonlinearity in each resonator
needed to achieve unconventional photon blockade is suppressed exponentially
with lattice size. The analytic derivation, based on a weak drive
approximation, is validated by wavefunction Monte Carlo simulations. These
findings show that customized lattices of coupled resonators can be powerful
tools for controlling multi-photon quantum states.",2106.08526v1
2021-06-21,Of Mice and Chickens: Revisiting the RC Time Constant Problem,"Avian hair cells depend on electrical resonance for frequency selectivity.
The upper bound of the frequency range is limited by the RC time constant of
hair cells because the sharpness of tuning requires that the resonance
frequency must be lower than the RC roll-off frequency. In contrast, tuned
mechanical vibration of the inner ear is the basis of frequency selectivity of
the mammalian ear. This mechanical vibration is supported by outer hair cells
(OHC) with their electromotility based on piezoelectricity, which is driven by
the receptor potential. Thus it is also subjected to the RC time constant
problem. Association of OHCs with a system with mechanical resonance leads to
piezoelectric resonance. This resonance can nullify the membrane capacitance
and solves the RC time constant problem for OHCs.",2106.11231v2
2021-06-22,Room And Cryogenic Temperature Behaviour of Magnetic Sensors Based on Gan/Si Single Saw Resonators,"This work analyzes resonance frequency shift vs. the applied magnetic field
strength for GHz operating GaN/Si SAW single resonators. Magnetostrictive
elements (Ni and CoFeB) were deposited in the proximity of the interdigitated
transducers (IDTs) of the resonators (A-type structures) and also over the
IDTs, after covering them with a BCB layer to avoid short circuits with IDTs
metal (B-type structures). This work targets emerging applications of SAW
resonators in driving spin wave pumping and in coupling of surface acoustic
waves (SAW) with superconducting Q-bits. Magnetic sensitivity of the SAWs was
analyzed at room temperature (RT) and at cryogenic temperatures, obtaining high
magnetic sensitivities at 16 K. According to our knowledge, GaN based SAWs are
first time used in magnetic applications; also, cryogenic behavior of magnetic
SAW sensors is first time analyzed.",2106.11605v1
2021-06-22,Doubly Heavy Tetraquark Resonant States,"Spectrum of the doubly heavy tetraquarks, $bb\bar q\bar q$, is studied in a
constituent quark model. Four-body problem is solved in a variational method
where the real scaling technique is used to identify resonant states above the
fall-apart decay thresholds. In addition to the two bound states that were
reported in the previous study we have found several narrow resonant states
above the $BB^*$ and $B^*B^*$ thresholds. Their structures are studied and are
interpreted by the quark dynamics. A narrow resonance with spin-parity
$J^P=1^+$ is found to be a mixed state of a compact tetraquark and a $B^*B^*$
scattering state. This is driven by a strong color Coulombic attraction between
the $bb$ quarks. Negative-parity excited resonances with $J^P=0^-$, $1^-$ and
$2^-$ form a triplet under the heavy-quark spin symmetry. It turns out that
they share a similar structure to the $\lambda$-mode of a singly heavy baryon
as a result of the strongly attractive correlation for the doubly heavy
diquark.",2106.11868v1
2021-06-28,Multiply-resonant Second-harmonic Generation using Surface Lattice Resonances in Aluminum Metasurfaces,"Nonlinear metamaterials show potential for realizing flat nonlinear optical
devices but generally lack in terms of achievable conversion efficiencies.
Recent work has focused on enhancing nonlinear processes by utilizing high
quality factor resonances, such as collective responses known as surface
lattice resonances (SLRs) taking place in periodic metal nanoparticle arrays.
Here, we investigate how the dispersive nature of SLRs affects the nonlinear
responses of SLR-supporting metasurfaces. Particularly, we measure
second-harmonic generation from aluminum nanoparticle arrays and demonstrate
that by tilting the sample along two orthogonal directions, the sample can be
made multiply-resonant for several pump and second-harmonic signal wavelength
combinations. Characterized metasurfaces are estimated to exhibit a
second-order susceptibility value of 0.40 pm/V, demonstrating aluminum as a
potential material for nonlinear metasurfaces.",2106.14504v1
2021-06-29,Model selection for $K^+Σ^-$ photoproduction within isobar model,"We utilise an isobar model to investigate the $K^+ \Sigma^-$ photoproduction
off a neutron in the resonance region. Except for the Born terms, we include
high-spin (spin-3/2 and spin-5/2) nucleon resonances in the consistent
formalism together with a few $\Delta$ and kaon resonances to achieve an
acceptable agreement with data. Interestingly, we reveal that no hyperon
resonances are needed to achieve a reasonable description of data. On the other
hand the $N(1720)3/2^+$ resonance was found to be very important for correct
description of data. The free parameters of the model were fitted to
experimental data from the LEPS and CLAS Collaborations on either differential
cross sections or photon beam asymmetry. The novel feature of the fitting
procedure is the use of a regularization method, the Least Absolute Shrinkage
Selection Operator, and information criteria in order to choose the best fit.",2106.15199v1
2021-06-29,Josephson Photonics with Simultaneous Resonances,"Inelastic Cooper pair tunneling across a voltage-biased Josephson junction in
series with one or more microwave cavities can generate photons via resonant
processes in which the energy lost by the Cooper pair matches that of the
photon(s) produced. We generalise previous theoretical treatments of such
systems to analyse cases where two or more different photon generation
processes are resonant simultaneously. We also explore in detail a specific
case where generation of a single photon in one cavity mode is simultaneously
resonant with the generation of two photons in a second mode. We find that the
coexistence of the two resonances leads to effective couplings between the
modes which in turn generate entanglement.",2106.15243v2
2021-06-29,Nanophotonic chiral sensing: How does it actually work?,"Nanophotonic chiral sensing has recently attracted a lot of attention. The
idea is to exploit the strong light-matter interaction in nanophotonic
resonators to determine the concentration of chiral molecules at ultra-low
thresholds, which is highly attractive for numerous applications in life
science and chemistry. However, a thorough understanding of the underlying
interactions is still missing. The theoretical description relies on either
simple approximations or on purely numerical approaches. We close this gap and
present a general theory of chiral light-matter interactions in arbitrary
resonators. Our theory describes the chiral interaction as a perturbation of
the resonator modes, also known as resonant states or quasi-normal modes. We
observe two dominant contributions: A chirality-induced resonance shift and
changes in the modes excitation and emission efficiencies. Our theory brings
new and deep insights for tailoring and enhancing chiral light-matter
interactions. Furthermore, it allows to predict spectra much more efficiently
in comparison to conventional approaches. This is particularly true as chiral
interactions are inherently weak and therefore perturbation theory fits
extremely well for this problem.",2106.15699v1
2021-06-30,Decay estimates for bi-Schrödinger operators in dimension one,"This paper is devoted to study the time decay estimates for bi-Schr\""odinger
operators $H=\Delta^{2}+V(x)$ in dimension one with decaying potentials $V(x)$.
We first deduce the asymptotic expansions of resolvent of $H$ at zero energy
threshold without/with the presence of resonances, and then characterize these
resonance spaces corresponding to different types of zero resonance in suitable
weighted spaces $L_s^2({\mathbf{R}})$. Next we use them to establish the sharp
$L^1-L^\infty$ decay estimates of Schr\""odinger groups $e^{-itH}$ generated by
bi-Schr\""odinger operators also with zero resonances. As a consequence,
Strichartz estimates are obtained for the solution of fourth-order
Schr\""odinger equations with potentials for initial data in
$L^2({\mathbf{R}})$. In particular, it should be emphasized that the presence
of zero resonances does not change the optimal time decay rate of $e^{-itH}$ in
dimension one, except at requiring faster decay rate of the potential.",2106.15966v4
2021-07-08,Three-body dynamics of the $a_1(1260)$ resonance from lattice QCD,"Resonant hadronic systems often exhibit a complicated decay pattern in which
three-body dynamics play a relevant or even dominant role. In this work we
focus on the $a_1(1260)$ resonance. For the first time, the pole position and
branching ratios of a three-body resonance are calculated from lattice QCD
using one-, two-, and three-meson interpolators and a three-body finite-volume
formalism extended to spin and coupled channels. This marks a new milestone for
ab-initio studies of ordinary resonances along with hybrid and exotic hadrons
involving three-body dynamics.",2107.03973v1
2021-07-09,Real-time sensing with multiplexed optomechanical resonators,"Nanoelectromechanical resonators have been successfully used for a variety of
sensing applications. Their extreme resolution comes from their small size at
the cost of low capture area, making the ""needle in a haystack"" issue acute.
This leads to poor instrument sensitivity and long analysis time. Moreover,
electrical transductions are limited in frequency, which limits the achievable
mechanical bandwidth again limiting throughput. Multiplexing a large number of
high-frequency resonators appears as a solution, but this is complex with
electrical transductions. We propose here a route to solve these issues, with a
multiplexing scheme for very high frequency optomechanical resonators. We
demonstrate the simultaneous frequency measurement of three silicon microdisks
resonators fabricated through a Very Large Scale Integration process. The
readout architecture is simple and does not degrade the sensing resolutions.
This paves the way towards the realization of sensors for multi-parametric
analysis, extremely low limit of detection and response time.",2107.04484v1
2021-07-09,Analysis and Modeling of an 11.8 GHz Fin Resonant Body Transistor in a 14nm FinFET CMOS Process,"In this work, a compact model is presented for a 14 nm CMOS-based FinFET
Resonant Body Transistor (fRBT) operating at a frequency of 11.8 GHz and
targeting RF frequency generation/filtering for next generation radio
communication, clocking, and sensing applications. Analysis of the phononic
dispersion characteristics of the device, which informs the model development,
shows the presence of polarization exchange due to the periodic nature of the
back-end-of-line (BEOL) metal PnC. An eigenfrequency-based extraction process,
applicable to resonators based on electrostatic force transduction, has been
used to model the resonance cavity. Augmented forms of the BSIM-CMG (Common
Multi-Gate) model for FinFETs are used to model the drive and sense transistors
in the fRBT. This model framework allows easy integration with the
foundry-supplied process design kits (PDKs) and circuit simulators while being
flexible towards change in transduction mechanisms and device architecture.
Ultimately, the behaviour is validated against RF measured data for the
fabricated fRBT device under different operating conditions, leading to the
demonstration of the first complete model for this class of resonant device
integrated seamlessly in the CMOS stack.",2107.04502v1
2021-07-29,Resonant pair-exchange scattering and BCS-BEC crossover in a system composed of dispersive and heavy incipient bands: a Feshbach analogy,"We theoretically show that a two-band system with very different masses
harbors a resonant pair scattering that leads to novel pairing properties, as
highlighted by the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein
condensation (BEC) crossover. Most importantly, the interband pair-exchange
coupling induces an effective intraband attraction in each band, enhancing the
superfluidity/superconductivity. The effect, a kind of Suhl-Kondo mechanism, is
specifically enhanced when the second band has a heavy mass and is incipient
(lying close to, but just above, the chemical potential, $\mu$), which we call
a resonant pair scattering. By elucidating the dependence of the effective
interactions and gap functions on $\mu$, we can draw an analogy between the
resonant pair scattering and the Feshbach resonance.",2107.13805v2
2021-08-07,Study of quasi-particle dynamics using the optical pulse response of asuperconducting resonator,"We study the optical pulse response of a superconducting half-wavelength
coplanar waveguide (CPW) resonator. We apply a short optical pulse to the
center strip of the CPW resonator, where the current distribution shows
antinodes or nodes for different resonance modes, and measure the frequency
response. We develop a time-dependent variable inductance circuit model with
which we can simulate the optical pulse response of the resonator. By fitting
this model to experimental data, we extract the temporal kinetic inductance
variations, which directly reflect the quasi-particle recombination with time
and diffusion in space. We also retrieve the spatial size of the quasi-particle
distribution and the quasi-particle diffusion constant. Our study is very
useful for the design of photon-counting kinetic inductance detectors, and the
method developed in this work provides a useful way to study the quasi-particle
dynamics in the superconductor.",2108.03423v1
2021-08-09,An inhibited laser,"Traditional lasers function using resonant cavities, in which the round-trip
optical path is exactly equal to an integer multiple of the intracavity
wavelengths to constructively enhance the spontaneous emission rate. By taking
advantage of the enhancement from the resonant cavity, the narrowest
sub-10-mHz-linewidth laser and a $10^{-16}$-fractional-frequency-stability
superradiant active optical clock (AOC) have been achieved. However, a laser
with atomic spontaneous radiation being destructively inhibited in an
anti-resonant cavity, where the atomic resonance is exactly between two
adjacent cavity resonances, has not been reported. Herein, we experimentally
demonstrate inhibited stimulated emission and termed it an inhibited laser.
Compared with traditional superradiant AOCs, which exhibit superiority in terms
of the high suppression of cavity noise, the suppression of the cavity-pulling
effect of an inhibited laser can be further improved by a factor of
$(2F/pi)^2$, i.e., 2.07 in this work, which was improved from 26 to 53 times.
This study will guide further development of AOCs with better stability, and
thus, it is significant for quantum metrology and may lead to new research in
the laser physics and cavity quantum electrodynamics fields.",2108.03972v2
2021-08-10,Adaptive Time-Resolved Mass Spectrometry with Nanomechanical Resonant Sensors,"Nanomechanical resonant sensors that are based on detecting and tracking the
resonance frequency deviations due to events of interest are being advocated
for a variety of applications. All sensor schemes currently in use are subject
to a basic trade-off between accuracy and speed, while there is great interest
in improving both in order to enable unprecedented and widespread applications.
Based on a thorough understanding of the characteristics of current resonant
sensor architectures, we propose adaptive and flexible sensor schemes. Unlike
recently proposed time-resolved mechanical detection methods, the proposed
schemes do not require ensemble averaging of the resonator response for many
independent identical stimuli. Distinct one-time events can be detected in
real-time with high time resolution with an accuracy that then improves
considerably with elapsed time. While the proposed adaptive schemes also need
to abide by the fundamental speed versus accuracy trade-off, we show that there
is still ""some room at the bottom"" for improvement with sensor architecture
innovations. Pareto optimal performance that reaches a bound that is imposed by
the fundamental thermomechanical noise can be achieved.",2108.04650v1
2021-08-10,Characteristic influence of exceptional points in quantum dynamics,"We review some recent work on the occurrence of coalescing eigenstates at
exceptional points in non-Hermitian systems and their influence on physical
quantities. We particularly focus on quantum dynamics near exceptional points
in open quantum systems, which are described by an outwardly Hermitian
Hamiltonian that gives rise to a non-Hermitian effective description after one
projects out the environmental component of the system. We classify the
exceptional points into two categories: those at which two or more resonance
states coalesce and those at which at least one resonance and the partnering
anti-resonance coalesce (possibly including virtual states as well), and we
introduce several simple models to explore the dynamics for both of these
types. In the latter case of coalescing resonance and anti-resonance states, we
show that the presence of the continuum threshold plays a strong role in
shaping the dynamics, in addition to the exceptional point itself. We also
briefly discuss the special case in which the exceptional point appears
directly at the threshold.",2108.04673v1
2021-08-10,On the Spurious Interior Resonance Modes of Time Domain Integral Equations for Analyzing Acoustic Scattering from Penetrable Objects,"The interior resonance problem of time domain integral equations (TDIEs)
formulated to analyze acoustic field interactions on penetrable objects is
investigated. Two types of TDIEs are considered: The first equation, which is
termed the time domain potential integral equation (TDPIE) (in unknowns
velocity potential and its normal derivative), suffers from the interior
resonance problem, i.e., its solution is replete with spurious modes that are
excited at the resonance frequencies of the acoustic cavity in the shape of the
scatterer. Numerical experiments demonstrate that, unlike the frequency-domain
integral equations, the amplitude of these modes in the time domain could be
suppressed to a level that does not significantly affect the solution. The
second equation is obtained by linearly combining TDPIE with its normal
derivative. Weights of the combination are carefully selected to enable the
numerical computation of the singular integrals. The solution of this equation,
which is termed the time domain combined potential integral equation (TDCPIE),
does not involve any spurious interior resonance modes.",2108.04889v1
2021-08-19,Resonant tidal responses in rotating fluid bodies: global modes hidden beneath localized wave beams,"In rotating stars and planets, excitation of inertial waves in convective
envelopes provides an important channel for tidal dissipation, but the
dissipation rate due to inertial waves depends erratically on the tidal
frequency. Tidal dissipation is significantly enhanced at some frequencies,
suggesting possible resonances between the tidal forcing and some eigenmodes.
However, the nature of these resonances remains enigmatic owing to the
singularity of the eigenvalue problem of inertial waves, and the resonances are
often mistakenly attributed to wave attractors in the literature. In this
letter, we reveal that resonant tidal responses correspond to inertial modes
with large-scale flows hidden beneath localized wave beams. Strong couplings
between the tidal forcing and the hidden large-scale flows intensify the
localized wave beams emanating from the critical latitudes, leading to enhanced
tidal dissipation. This study resolves a long-standing puzzle regarding the
frequency-dependence of tidal dissipation due to inertial waves in convective
envelopes.",2108.08515v2
2021-08-24,Higher-order ferromagnetic resonances in periodic arrays of synthetic-antiferromagnet nanodiscs,"We investigate spin dynamics in nanodisc arrays of synthetic-antiferromagnets
(SAF) made of Py/NiCu/Py trilayers, where the NiCu spacer undergoes a Curie
transition at about 200 K. The observed ferromagnetic resonance spectra have
three distinct resonance modes at room temperature, which are fully recreated
in our micromagnetic simulations showing also how the intra-SAF asymmetry can
be used to create and control the higher-order resonances in the structure.
Below the Curie temperature of the spacer, the system effectively transitions
into a single-layer nanodisc array with only two resonance modes. Our results
show how multi-layering of nano-arrays can add tunable GHz functionality
relevant for such rapidly developing fields as magnetic meta-materials,
magnonic crystals, arrays of spin-torque oscillators and neuromorphic
junctions.",2108.10581v1
2021-08-29,The Fragmented Glueball: A Personal View,"A coupled-channel analysis has been performed to identify the spectrum of
scalar mesons. The data include BESIII data on radiative $J/\psi$ decays into
$\pi^0\pi^0$,$K_SK_S$, $\eta\eta$, and $\omega\phi$, 15 Dalitz plots from $\bar
pN$ annihilation at rest at LEAR, the CERN-Munich multipoles for $\pi\pi$
elastic scattering, the $S$-wave from BNL data on $\pi\pi$ scattering into
$K_SK_S$, from GAMS data on $\pi\pi\to \pi^0\pi^0, \eta\eta$, and $\eta\eta'$,
and NA48/2 data on low-mass $\pi\pi$ interactions from $K^\pm\to\pi\pi
e^\pm\nu$ decays. The analysis reveals the existence of ten scalar isoscalar
resonances. The resonances can be grouped into two classes: resonances with a
large SU(3) singlet component and those with a large octet component. The
production of isoscalar resonances with a large octet component should be
suppressed in radiative $J/\psi$ decays. However, in a limited mass range
centered at 1900\,MeV, these mesons are produced abundantly. Mainly-singlet
scalar resonances are produced over the full mass range but with larger
intensity at 1900\,MeV. The total scalar isoscalar yield in radiative decays
into scalar mesons shows a clear peak which is interpreted as the scalar
glueball of lowest mass.",2108.12819v1
2021-09-12,Accelerated ground-state cooling of an optomechanical resonator via shortcuts to adiabaticity,"Ground-state cooling of mechanical resonators is an important task in quantum
optomechanics, because it is a necessary prerequisite for creation,
manipulation, and application of macroscopic mechanical coherence. Here, we
propose a transient-state scheme to accelerate ground-state cooling of a
mechanical resonator in a three-mode loop-coupled optomechanical system via
shortcuts to adiabaticity (STA). We consider four kinds of coupling protocols
and calculate the evolution of the mean phonon number of the mechanical
resonator in both the adiabatic and STA cases. We verify that the ground-state
cooling of the mechanical resonator can be achieved with the STA method in a
much shorter period. The STA method can also be generalized to accelerate other
adiabatic processes in cavity optomechanics, and hence this work will open up a
new realm of fast optomechanical manipulations.",2109.05538v3
2021-09-15,Varying the medium surrounding an optical resonator: An efficient and rigorous way to calculate its spectral changes,"Finding reliably and efficiently the spectrum of the resonant states of an
optical system under varying parameters of the medium surrounding it is a
technologically important task, primarily due to various sensing applications.
Computationally, it presents, however, a fundamental challenge owing to the
nature of the eigenstates of an open system lacking completeness outside it. We
solve this challenge by making a linear transformation of Maxwell's equations
which maps perturbations of the surrounding medium onto effective perturbations
within the system where the resonant states are complete. By treating such
perturbations with the rigorous resonant state expansion, we find the modified
modes of the system for arbitrary perturbations of the medium with any required
accuracy. Numerically efficient single and few mode approximations are shown to
be precise in practically important cases of, respectively, plasmonic
nanoparticles and dielectric micro resonators.",2109.07026v2
2021-09-20,"Electron Spin Resonance of the itinerant ferromagnets LaCrGe3, CeCrGe3 and PrCrGe3","We report Electron Spin Resonance of the itinerant ferromagnets LaCrGe3,
CeCrGe3, and PrCrGe3. These compounds show well defined and very similar
spectra of itinerant Cr 3d spins in the paramagnetic temperature region. Upon
cooling and crossing the Cr-ferromagnetic ordering (below around 90 K) strong
spectral structures start to dominate the resonance spectra in a quite
different manner in the three compounds. In the Ce- and Pr-compounds the
resonance is only visible in the paramagnetic region whereas in the La-compound
the resonance can be followed far below the ferromagnetic ordering temperature.
This behavior will be discussed in terms of the specific interplay between the
4f and 3d magnetism which appears quite remarkable since CeCrGe3 displays heavy
fermion behavior even in the magnetically ordered state.",2109.09341v1
2021-09-21,Heavy states and electroweak effective approaches,"The existence of a mass gap between the Standard Model (SM) and possible new
states encourages us to use effective field theories. Here we follow the
non-linear realization of the electroweak symmetry breaking: the electroweak
effective theory (EWET), also known as Higgs effective field theory (HEFT) or
electroweak chiral Lagrangian (EWChL). At short distances an effective
resonance Lagrangian which couples the SM states to bosonic and fermionic
resonances is considered. After integrating out the resonances and assuming a
well-behaved high-energy behavior, we estimate or bound purely bosonic
low-energy constants in terms of only resonance masses. Current experimental
information on these low-energy constants allows us to constrain the
high-energy resonance masses.",2109.10195v1
2021-09-28,The effects of ion implantation damage to photonic crystal optomechanical resonators in silicon,"Optomechanical resonators were fabricated on a silicon-on-insulator (SOI)
substrate that had been implanted with phosphorus donors. The resonators'
mechanical and optical properties were then measured (at 6 kelvin and room
temperature) before and after the substrate was annealed. All measured
resonators survived the annealing and their mechanical linewidths decreased
while their optical and mechanical frequencies increased. This is consistent
with crystal lattice damage from the ion implantation causing the optical and
mechanical properties to degrade and then subsequently being repaired by the
annealing. We explain these effects qualitatively with changes in the silicon
crystal lattice structure. We also report on some unexplained features in the
pre-anneal samples. In addition, we report partial fabrication of
optomechanical resonators with neon ion milling.",2109.13856v1
2021-09-30,Computation and Analysis of Jupiter-Europa and Jupiter-Ganymede Resonant Orbits in the Planar Concentric Circular Restricted 4-Body Problem,"Many unstable periodic orbits of the planar circular restricted 3-body
problem (PCRTBP) persist as invariant tori when a periodic forcing is added to
the equations of motion. In this study, we compute tori corresponding to
exterior Jupiter-Europa and interior Jupiter-Ganymede PCRTBP resonant periodic
orbits in a concentric circular restricted 4-body problem (CCR4BP). Motivated
by the 2:1 Laplace resonance between Europa and Ganymede's orbits, we then
attempt the continuation of a Jupiter-Europa 3:4 resonant orbit from the CCR4BP
into the Jupiter-Ganymede PCRTBP. We strongly believe that the resulting
dynamical object is a KAM torus lying near but not on the 3:2 Jupiter-Ganymede
resonance.",2109.14815v1
2021-10-04,Anomalous temperature dependence of phonon pumping by ferromagnetic resonance in Co/Pd multilayers with perpendicular anisotropy,"We demonstrate the pumping of phonons by ferromagnetic resonance in a series
of [Co(0.8 nm)/Pd(1.5 nm)]$_n$ multilayers ($n =$ 6, 11, 15, and 20) with large
magnetostriction and perpendicular magnetic anisotropy. The effect is shown
using broadband ferromagnetic resonance over a range of temperatures (10 to 300
K), where a resonant damping enhancement is observed at frequencies
corresponding to standing wave phonons across the multilayer. The strength of
this effect is enhanced by approximately a factor of 4 at 10 K compared to room
temperature, which is anomalous in the sense that the temperature dependence of
the magnetostriction predicts an enhancement that is less than a factor of 2.
Lastly, we demonstrate that the damping enhancement is correlated with a shift
in the ferromagnetic resonance field as predicted quantitatively from linear
response theory.",2110.01714v1
2021-10-11,Quantum Squeezing Induced Optical Nonreciprocity,"We propose an all-optical approach to achieve optical nonreciprocity on a
chip by quantum squeezing one of two coupled resonator modes. By parametric
pumping a nonlinear resonator unidirectionally with a classical coherent field,
we squeeze the resonator mode in a selective direction due to the
phase-matching condition, and induce a chiral photon interaction between two
resonators. Based on this chiral interresonator coupling, we achieve an
all-optical diode and a three-port quasi-circulator. By applying a second
squeezed-vacuum field to the squeezed resonator mode, our nonreciprocal device
also works for single-photon pulses. We obtain an isolation ratio of >40 dB for
the diode and fidelity of $>98\%$ for the quasi-circulator, and insertion loss
of <1 dB for both. We also show that nonreciprocal transmission of strong light
can be switched on and off by a relative weak pump light. This achievement
implies a nonreciprocal optical transistor. Our protocol opens up a new route
to achieve integrable all-optical nonreciprocal devices permitting
chip-compatible optical isolation and nonreciporcal quantum information
processing.",2110.05016v1
2021-10-25,"Spin relaxation, Josephson effect and Yu-Shiba-Rusinov states in superconducting bilayer graphene","Bilayer graphene has two non-equivalent sublattices and, therefore, the same
adatom impurity can manifest in spectrally distinct ways-sharp versus broad
resonances near the charge neutrality-depending on the sublattice it adsorbs
at. Employing Green's function analytical methods and the numerical Kwant
package we investigate the spectral and transport interplay between the
resonances and superconducting coherence induced in bilayer graphene by
proximity to an s-wave superconductor. Analyzing doping and temperature
dependencies of quasi-particle spin-relaxation rates, energies of
Yu-Shiba-Rusinov states, Andreev spectra and the supercurrent characteristics
of Josephson junctions we find unique superconducting signatures discriminating
between resonant and off-resonant regimes. Our findings are in certain aspects
going beyond the superconducting bilayer graphene and hold for generic s-wave
superconductors functionalized by the resonant magnetic impurities.",2110.12998v2
2021-10-23,Resonant mode coupling approximation for calculation of optical spectra of photonic crystal slabs,"We develop the resonant mode coupling approximation to calculate the optical
spectra of a stack of two photonic crystal slabs. The method is based on a
derivation of the input and output resonant vectors in each slab in terms of
the Fourier modal method in the scattering matrix form. We show that using the
resonant mode coupling approximation of the scattering matrices of the upper
and lower slabs, one can construct the total scattering matrix of the stack.
The formation of the resonant output and input vectors of the stacked system is
rigorously derived by means of an effective Hamiltonian. We demonstrate that
the proposed procedure dramatically decreases the computation time without
sufficient loss of accuracy. We believe that the proposed technique can be a
powerful tool for fast solving inverse scattering problems using stochastic
optimization methods such as genetic algorithms or machine learning.",2110.13647v3
2021-10-30,Nanoscale Raman Characterization of a 2D Semiconductor Lateral Heterostructure Interface,"The nature of the interface in lateral heterostructures of 2D monolayer
semiconductors including its composition, size, and heterogeneity critically
impacts the functionalities it engenders on the 2D system for next-generation
optoelectronics. Here, we use tip-enhanced Raman scattering (TERS) to
characterize the interface in a single-layer MoS2/WS2 lateral heterostructure
with a spatial resolution of 50 nm. Resonant and non-resonant TERS
spectroscopies reveal that the interface is alloyed with a size that varies
over an order of magnitude-from 50-600 nm-within a single crystallite.
Nanoscale imaging of the continuous interfacial evolution of the resonant and
non-resonant Raman spectra enables the deconvolution of defect-activation,
resonant enhancement, and material composition for several vibrational modes in
single-layer MoS2, MoxW1-xS2, and WS2. The results demonstrate the capabilities
of nanoscale TERS spectroscopy to elucidate macroscopic structure-property
relationships in 2D materials and to characterize lateral interfaces of 2D
systems on length scales that are imperative for devices.",2111.00135v1
2021-11-03,Cross-polarized surface lattice resonances in a rectangular lattice plasmonic metasurface,"Multiresonant metasurfaces could enable many applications in filtering,
sensing and nonlinear optics. However, developing a metasurface with more than
one high-quality-factor or high-Q resonance at designated resonant wavelengths
is challenging. Here, we experimentally demonstrate a plasmonic metasurface
exhibiting different, narrow surface lattice resonances by exploiting the
polarization degree of freedom where different lattice modes propagate along
different dimensions of the lattice. The surface consists of aluminum
nanostructures in a rectangular periodic lattice. The resulting surface lattice
resonances were measured around 630 nm and 1160 nm with Q-factors of ~50 and
~800, respectively. The latter is a record-high plasmonic Q-factor within the
near-infrared type-II window. Such metasurfaces could benefit applications such
as frequency conversion and all-optical switching.",2111.02472v1
2021-11-04,Charmonium-like resonances in coupled $D \bar D$-$D_s \bar D_s$ scattering,"Charmonium-like resonances and bound states with isospin zero and
$J^{PC}=0^{++},~1^{--},~2^{++},~3^{--}$ are extracted on the lattice. Coupled
$D\bar D$ and $D_s\bar D_s$ scattering suggests three charmonium-like states
with $J^{PC}=0^{++}$ in addition to $\chi_{c0}(1P)$: a so far unobserved $D\bar
D$ bound state just below threshold, a conventional resonance likely related to
$\chi_{c0}(3860)/\chi_{c0}(2P)$ and a narrow resonance just below the $D_s\bar
D_s$ threshold with a large coupling to $D_s\bar D_s$ likely related to
$X(3915)/\chi_{c0}(3930)$. One-channel $D\bar D$ scattering renders resonances
and bound states with $J^{PC}= 1^{--},~2^{++},~3^{--}$ related to the observed
conventional charmonia. Lattice QCD ensembles from the CLS consortium with
$m_{\pi}\simeq 280$ MeV are utilized.",2111.02934v2
2021-11-04,Optimization of the double electron-electron resonance for C-centers in diamond,"NV centers in diamond recommend themselves as good sensors of environmental
fields as well as detectors of diamond impurities. In particular, C-centers,
often also called ${{p}_{1}}$-centers, can be detected via double
electron-electron resonance. This resonance can be used to measure the C-center
concentration. Here, we measured the concentration of C-centers in several
diamond plates and investigated the influence of the free precession time of
the NV center on the observed contrast in the measured double electron-electron
resonance spectrum. The dependence of the resonance amplitudes and widths on
the concentration of C-centers as well as the length of the combined C-center
driving and NV-center $\pi$-pulse is also discussed. The optimal contrast-free
precession time was determined for each C-center concentration, showing a
strong correlation with both the concentration of C-centers and the NV-center
${{T}_{2}}$ time.",2111.07778v1
2021-11-26,Ultrastrong Coupling of a Qubit with a Nonlinear Optical Resonator,"We study the interaction of a two-level atom with a single-mode nonlinear
electromagnetic resonator, considering coupling strengths ranging from zero to
the so-called deep strong coupling regime. When the qubit-resonator coupling is
very strong, the standard Kerr model for the resonator becomes questionable.
Moreover, recently, it has been shown that extra care is needed when
constructing gauge-independent theories in the presence of approximations as
the truncation of the Hilbert space of the matter system. Such a truncation can
ruin gauge invariance leading to non-physical results, especially when the
light-matter interactions strength is very high. Here we face and solve this
issues to provide a consistent nonlinear-resonator quantum Rabi model
satisfying the gauge principle.",2111.13442v3
2021-12-01,Pulse induced resonance with angular dependent total enhancement of multi-dimensional solid-state NMR correlation spectra,"We demonstrate a new resonance condition that obeys the relation
${\Delta}{\delta}=n{\nu}_{R}/2$, where ${\Delta}{\delta}$ is the chemical shift
difference between two homonuclear-coupled spins, ${\nu}_{R}$ is the
magic-angle spinning speed and $n$ is an integer. This modulation on the
rotational resonance recoupling condition is obtained by the application of
rotor-synchronous $^{1}$H pulses when at least one proton is dipolar-coupled to
one of the homonuclear-coupled spins. We suggest a new experimental scheme
entitled ""pulse induced resonance with angular dependent total enhancement""
(PIRATE) that can enhance proton-driven spin diffusion by the application of a
single $^{1}$H pulse every rotor period. Experimental evidence is demonstrated
on the two carbon spins of glycine and on the Y21M mutant of fd bacteriophage
virus. Numerical simulations reveal the existence of the resonances and report
on the important interactions governing this phenomena.",2112.00438v2
2021-12-06,120-fs single-pulse generation from stretched-pulse fiber Kerr resonators,"Fiber Kerr resonators are simple driven resonators with desirable wavelength
and repetition rate flexibility for generating ultrashort pulses for
applications including telecommunications, biomedicine, and materials
processing. However, fiber Kerr resonators to date often generate longer pulses
and require more complicated techniques for generating single pulses than would
be desirable for applications. Here we address these limits by demonstrating
robust single-pulse performance with 120-fs pulse durations in fiber Kerr
resonators based on stretched-pulse solitons. Through matching numerical and
experimental studies, stretched-pulse soliton performance is found to strongly
depend on the total cavity length, and the optimum length is found to depend on
the drive, Raman scattering, and the total pulse stretching. By designing the
cavity for this optimum with the described setup, stable stretched-pulse
solitons with 120-fs duration are experimentally observed. In addition, soliton
trapping is demonstrated with a pulsed drive source despite large intracavity
breathing and single-pulse performance is observed. Robust with high
performance single-pulse generation is a critical step toward useful
femtosecond pulse generation.",2112.03323v2
2021-12-09,Low-loss high-impedance circuit for quantum transduction between optical and microwave photons,"Quantum transducers between microwave and optical photons are essential for
long-distance quantum networks based on superconducting qubits. An optically
active self-assembled quantum dot molecule (QDM) is an attractive platform for
the implementation of a quantum transducer because an exciton in a QDM can be
efficiently coupled to both optical and microwave fields at the single-photon
level. Recently, the transduction between microwave and optical photons has
been demonstrated with a QDM integrated with a superconducting resonator. In
this paper, we present a design of a QD-high impedance resonator device with a
low microwave loss and an expected large single-microwave photon coupling
strength of 100s of MHz. We integrate self-assembled QDs onto a high-impedance
superconducting resonator using a transfer printing technique and demonstrate a
low-microwave loss rate of 1.8 MHz and gate tunability of the QDs. The
microwave loss rate is much lower than the expected QDM-resonator coupling
strength as well as the typical transmon-resonator coupling strength. This
feature will facilitate efficient quantum transduction between an optical and
microwave qubit.",2112.05089v1
2021-12-09,Transition from Lorentz to Fano Spectral Line Shapes in Non-Relativistic Quantum Electrodynamics,"Spectroscopic signatures associated with symmetric Lorentzian and asymmetric
Fano line shapes are ubiquitous. Distinct features of Fano resonances in
contrast with conventional symmetric resonances have found several applications
in photonics such as optical switching, sensing, lasing, and nonlinear and
slow-light devices. Therefore, it is important to have control over the
generation of these resonances. In this work, we show through ab initio
simulations of coupled light-matter systems that Fano interference phenomena
can be realized in a multimode photonic environment by strong coupling to the
electromagnetic continuum. Specifically, we show that by effectively enhancing
the light-matter coupling strength to the photon continuum in an experimentally
feasible way, we can achieve a transition from Lorentzian to Fano lines shapes
for both electronic and polaritonic excitations. An important outcome of
switching between these spectral signatures is the possibility to control the
Purcell enhancement of spontaneous emission alongside electromagnetically
induced transparency which is a special case of Fano resonances. Switching from
Fano back to a Lorentzian profile can be achieved by physically reducing the
coupling strength to the continuum of modes. Our results hold potential for
realizing tunable Fano resonances of molecules and materials interacting with
the electromagnetic continuum within multimode photonic environments.",2112.05114v1
2021-12-21,Toffoli gate based on a three-body fine-structure-state-changing Förster resonance in Rydberg atoms,"We have developed an improved scheme of a three-qubit Toffoli gate based on
fine structure state changing three-body Stark-tuned Rydberg interaction. This
scheme is a substantial improvement of our previous proposal [I.I.Beterov et
al., Physical Review A 98, 042704 (2018)]. Due to the use of a different type
of three-body F\""orster resonance we substantially simplified the scheme of
laser excitation and phase dynamics of collective three-body states. This type
of F\""orster resonance exists only in systems with more than two atoms, while
the two-body resonance is absent. We reduced the sensitivity of the gate
fidelity to fluctuations of external electric field and eliminated the
necessity to use external magnetic field for fine tuning of the resonant
electric field value, compared to the previous scheme of Toffoli gate based on
Rydberg atoms. A gate fidelity of >99% was demonstrated in the calculations.",2112.11058v2
2021-12-23,Local random vector model for semiclassical fractal structure of chaotic resonance states,"The semiclassical structure of resonance states of classically chaotic
scattering systems with partial escape is investigated. We introduce a local
randomization on phase space for the baker map with escape, which separates the
smallest multifractal scale from the scale of the Planck cell. This allows for
deriving a semiclassical description of resonance states based on a local
random vector model and conditional invariance. We numerically demonstrate that
the resulting classical measures perfectly describe resonance states of all
decay rates $\gamma$ for the randomized baker map. By decreasing the scale of
randomization these results are compared to the deterministic baker map with
partial escape. This gives the best available description of its resonance
states. Quantitative differences indicate that a semiclassical description for
deterministic chaotic systems must take into account that the multifractal
structures persist down to the Planck scale.",2112.12626v2
2021-12-27,Ultraviolet Mie resonances in computationally discovered boron phosphide nanoparticles,"Controlling ultraviolet light at the nanoscale using optical Mie resonances
holds great promise for a diverse set of applications, such as lithography,
sterilization, and biospectroscopy. However, Mie resonances hosted by
dielectric nanoantennas are difficult to realize at ultraviolet wavelengths due
to the lack of both suitable materials and fabrication methods. Here, we
systematically search for improved materials by computing the frequency
dependent optical permittivity of 338 binary semiconductors and insulators from
first principles, and evaluate their potential performance as high refractive
index materials using Mie theory. Our analysis reveals several interesting
candidate materials among which boron phosphide (BP) appears particularly
promising. We then prepare BP nanoparticles and demonstrate that they support
Mie resonances at visible and ultraviolet wavelengths using both far-field
optical measurements and near-field electron energy-loss spectroscopy. We also
present a laser reshaping method to realize spherical Mie-resonant BP
nanoparticles. With a refractive index above 3 and low absorption losses, BP
nanostructures advance Mie optics to the ultraviolet.",2112.13600v1
2022-01-18,Measuring High-Order Phonon Correlations in an Optomechanical Resonator,"We use single photon detectors to probe the motional state of a superfluid
$^4$He resonator of mass $\sim1$ ng. The arrival times of Stokes and
anti-Stokes photons (scattered by the resonator's acoustic mode) are used to
measure the resonator's phonon coherences up to the fourth order. By
post-selecting on photon detection events, we also measure coherences in the
resonator when $\leq3$ phonons have been added or subtracted. These
measurements are found to be consistent with predictions that assume the
acoustic mode to be in thermal equilibrium with a bath through a Markovian
coupling.",2201.07340v1
2022-01-30,Port Reconfigurable Phase-Change Optical Resonator,"Active control and manipulation of electromagnetic waves are highly desirable
for advanced photonic device technology, such as optical cloaking, active
camouflage and information processing. Designing optical resonators with high
ease-of-control and reconfigurability remains a open challenge thus far. Here
we propose a novel mechanism to continuously reconfigure an optical resonator
between one-port and two-port configurations via \emph{phase-change material}
for efficient optical modulation. By incorporating a phase-change material
VO$_2$ substrate into a photonic crystal optical resonator, we computationally
show that the system behaves as a one-port device with near-perfect absorption
and two-port device with high transmission up to 92% when VO$_2$ is in the
metallic rutile phase and insulating monoclinic phase, respectively. The
optical response can be continuously and reversibly modulated between various
intermediate states. More importantly, the proposed device is compatible with
wide-angle operation and is robust against structural distortion. Our findings
reveal a novel device architecture of \emph{port reconfigurable} optical
resonator uniquely enabled by switchable optical properties of phase change
material.",2201.12800v1
2022-02-01,Pion axioproduction: The Delta resonance contribution,"The process of pion axioproduction, $aN\to\pi N$, with an intermediate
$\Delta$ resonance is analyzed using baryon chiral parturbation theory. The
$\Delta$ resonance is included in two ways: First, deriving the $a\Delta
N$-vertices, the axion is brought into contact with the resonance, and, second,
taking the results of $\pi N$ elastic scattering including the $\Delta$, it is
implicitly included in the form of a pion rescattering diagram. As a result,
the partial wave cross section of axion-nucleon scattering shows an enhancement
in the energy region around the $\Delta$ resonance. Because of the isospin
breaking, the enhancement is not as pronounced as previously anticipated.
However, since the isospin breaking here is much milder than that for usual
hadronic processes, novel axion search experiments might still exploit this
effect.",2202.00268v2
2022-02-04,Three-photon excitation of quantum two-level systems,"We demonstrate that semiconductor quantum dots can be excited efficiently in
a resonant three-photon process, whilst resonant two-photon excitation is
highly suppressed. Time-dependent Floquet theory is used to quantify the
strength of the multi-photon processes and model the experimental results. The
efficiency of these transitions can be drawn directly from parity
considerations in the electron and hole wavefunctions in semiconductor quantum
dots. Finally, we exploit this technique to probe intrinsic properties of InGaN
quantum dots. In contrast to non-resonant excitation, slow relaxation of charge
carriers is avoided which allows us to measure directly the radiative lifetime
of the lowest energy exciton states. Since the emission energy is detuned far
from the resonant driving laser field, polarization filtering is not required
and emission with a greater degree of linear polarization is observed compared
to non-resonant excitation.",2202.02034v2
2022-02-04,Absorption characteristics of large acoustic metasurfaces,"Metasurfaces formed of arrays of subwavelength resonators are often tuned to
'critically couple' with incident radiation, so that at resonance dissipative
and radiative damping are balanced and absorption is maximised. Such design
criteria are typically derived assuming an infinite metasurface, whereas the
absorption characteristics of finite metasurfaces, even very large ones, can be
markedly different in certain frequency intervals. This is due to the
excitation of surface waves, intrinsic to resonant metasurfaces, and especially
meta-resonances, namely collective resonances where the surface waves form
standing-wave patterns over the planar metasurface domain. We illustrate this
issue using a detailed model of a Helmholtz-type acoustic metasurface formed of
cavity-neck pairs embedded into a rigid substrate, with geometric and
dissipation effects included from first principles (R. Brand\~ao and O.
Schnitzer, Wave Motion, 97 102583, 2020).",2202.03175v2
2022-02-13,Angular distribution of $γ$ rays from the p-wave resonance of $^{118}$Sn,"The neutron energy-dependent angular distribution of $\gamma$ rays from
$^{117}{\rm Sn}(n,\gamma)$ reaction was measured with germanium detectors and a
pulsed neutron beam. The angular distribution was clearly observed in
$\gamma$-ray emissions with an energy of 9327 keV which corresponds to the
transition from a neutron resonance of $^{117}{\rm Sn}+n$ to the ground state
of $^{118}{\rm Sn}$. The angular distribution causes an angular-dependent
asymmetric resonance shape. An asymmetry $A_{\rm LH}$ was defined as $(N_{\rm
L}-N_{\rm H})/(N_{\rm L}+N_{\rm H})$, where $N_{\rm L}$ and $N_{\rm H}$ are
integrated values for lower- and higher-energy regions of a neutron resonance,
respectively. We found that the $A_{\rm LH}$ has the angular dependence of $(A
\cos \theta_\gamma +B)$, where $\theta_\gamma$ is the $\gamma$-ray emission
angle with respect to the incident neutron momentum, with $A=0.394 \pm 0.073$
and $B = 0.118 \pm 0.029$ in the 1.33 eV p-wave resonance.",2202.06222v1
2022-02-17,Magnetic terahertz resonances above the Néel temperature in the frustrated kagome antiferromagnet averievite,"Time-domain magneto-THz spectroscopy is utilized to study the frustrated
magnet averievite Cu$_{5-x}$Zn$_x$V$_2$O$_{10}$(CsCl). Pronounced THz
resonances are observed in unsubstituted samples ($x=0$) when cooling below the
onset of short-range magnetic correlations. The influence of external magnetic
effects confirms the magnetic origin of these resonances. Increasing Zn
substitution suppresses the resonances, as frustration effects dominate,
reflecting the non-magnetic phases for $x> 0.25$ compounds. The temperature
evolution of the THz spectra is complemented with electron spin resonance
spectroscopy. This comparison allows a direct probe of the different
contributions from magnetic order, frustration, and structural properties in
the phase diagram of averievite. Our results illustrate the effect of magnetic
interactions in THz spectra of frustrated magnets.",2202.08577v2
2022-02-24,The role of low energy resonances in the stereodynamics of cold He+D2 collisions,"In recent experiments using the Stark-induced Adiabatic Raman Passage (SARP)
technique, Zhou et al. measured the product's angular distribution for the
collisions between He and aligned D2 molecules at cold collision energies. The
signatures of the angular distributions were attributed to a l=2 resonance that
governs scattering at low energies. A first principles quantum mechanical
treatment of this problem is presented here using a highly accurate interaction
potential for the He-H2 system. Instead, our results predict a very intense l=1
resonance at low energies, leading to angular distributions that differ from
those measured in the experiment. A good agreement with the experiment is
achieved only when the l=1 resonance is artificially removed, for example, by
excluding the lowest energies present in the experimental velocity
distribution. Our analysis revealed that neither the position nor the intensity
of the l=1 resonance significantly changes when the interaction potential is
modified within its predicted uncertainties. Energy-resolved measurements may
help to resolve the discrepancy.",2202.12238v2
2022-02-28,Use of Transmission and Reflection Complex Time Delays to Reveal Scattering Matrix Poles and Zeros: Example of the Ring Graph,"We identify the poles and zeros of the scattering matrix of a simple quantum
graph by means of systematic measurement and analysis of Wigner, transmission,
and reflection complex time delays. We examine the ring graph because it
displays both shape and Feshbach resonances, the latter of which arises from an
embedded eigenstate on the real frequency axis. Our analysis provides a unified
understanding of the so-called shape, Feshbach, electromagnetically-induced
transparency, and Fano resonances, on the basis of the distribution of poles
and zeros of the scattering matrix in the complex frequency plane. It also
provides a first-principles understanding of sharp resonant scattering
features, and associated large time delay, in a variety of practical devices,
including photonic microring resonators, microwave ring resonators, and
mesoscopic ring-shaped conductor devices. Our analysis is the first use of
reflection time difference, as well as the first comprehensive use of complex
time delay, to analyze experimental scattering data.",2202.13539v2
2022-03-01,Determination of atomic multiphoton ionization phases by trichromatic multichannel wave packet interferometry,"We present a multichannel photoelectron interferometry technique based on
trichromatic pulse shaping for unambiguous determination of quantum phases in
multiphoton ionization (MPI) of potassium atoms. The colors of the laser field
are chosen to produce three energetically separated photoelectron
interferograms in the continuum. While the red pulse is two-photon resonant
with the $3d$-state resulting in a (2+1) resonance-enhanced MPI (REMPI), a
(1+2) REMPI occurs via the non-resonant intermediate $4p$-state with an initial
green or blue pulse. We show that ionization via a non-resonant intermediate
state lifts the degeneracy of photoelectron interferograms from pathways
consisting of permutations of the colors. The analysis of the interferograms
reveals a phase shift of $\pm \pi/2$ depending on the sign of the detunings in
the (1+2) REMPI pathways. In addition, we demonstrate that the photoionization
time delay in the resonant (2+1) REMPI pathway gives rise to a linear spectral
phase in the photoelectron spectra. Insights into the underlying MPI processes
are gained through an analytic perturbative description and numerical
simulations of a trichromatic driven three level system coupled to the
continuum.",2203.00323v2
2022-03-02,Time-Domain Analysis for Resonant Beam Charging and Communications With Delay-Divide Demodulation,"Laser has unique advantages such as abundant spectrum resources and low
propagation divergence in wireless charging and wireless communications,
compared with radio frequency. Resonant beams, as a kind of intra-cavity laser
beams, have been proposed as the carrier of wireless charging and
communication, as it has unique features including high power, intrinsic
safety, and self-aligned mobility. However, this system has problems such as
intra-cavity echo interference and power fluctuation. To study the time-domain
behavior of the resonant beam system, we create a simulation algorithm by
discretizing the laser rate equations which model the dynamics of the excited
atom density in the gain medium and the photon density in the cavity. The
simulation results are in good agreement with theoretical calculation. We also
propose a delay-divide demodulation method to address the echo interference
issue, and use the simulation algorithm to verify its feasibility. The results
show that the resonant beam charging and communication system with the proposed
demodulator is feasible and performs well. The analysis in this work also helps
researchers to deeply understand the behavior of the resonant beam system.",2203.01076v1
2022-03-09,Resonant control of elastic collisions between $^{23}$Na$^{40}$K molecules and $^{40}$K atoms,"We have demonstrated the resonant control of the elastic scattering cross
sections in the vicinity of Feshbach resonances between $^{23}$Na$^{40}$K
molecules and $^{40}$K atoms by studying the thermalization between them. The
elastic scattering cross sections vary by more than two orders of magnitude
close to the resonance, and can be well described by an asymmetric Fano
profile. The parameters that characterize the magnetically tunable s-wave
scattering length are determined from the elastic scattering cross sections.
The observation of resonantly controlled elastic scattering cross sections
opens up the possibility to study strongly interacting atom-molecule mixtures
and improve our understanding of the complex atom-molecule Feshbach resonances.",2203.04584v1
2022-03-11,Nonreciprocal Infrared Absorption via Resonant Magneto-optical Coupling to InAs,"Nonreciprocal elements are a vital building block of electrical and optical
systems. In the infrared regime, there is a particular interest in structures
that break reciprocity because their thermal absorptive (and emissive)
properties should not obey the Kirchhoff thermal radiation law. In this work,
we break time-reversal symmetry and reciprocity in n-type doped magneto-optic
InAs with a static magnetic field where light coupling is mediated by a
guided-mode-resonator (GMR) structure whose resonant frequency coincides with
the epsilon-near-zero (ENZ) resonance of the doped InAs. Using this structure,
we observe the nonreciprocal absorptive behavior as a function of magnetic
field and scattering angle in the infrared. Accounting for resonant and
nonresonant optical scattering, we reliably model experimental results that
break reciprocal absorption relations in the infrared. The ability to design
such nonreciprocal absorbers opens an avenue to explore devices with unequal
absorptivity and emissivity in specific channels.",2203.06227v1
2022-03-17,Compact superconducting microwave resonators based on Al-AlOx-Al capacitor,"We address the scaling-up problem for superconducting quantum circuits by
using lumped-element resonators based on an alternative fabrication method of
aluminum -- aluminum oxide -- aluminum ($\mathrm{Al/AlO_x/Al}$) parallel-plate
capacitors. The size of the resonators is only 0.04~$\mathrm{mm^2}$, which is
more than one order smaller than the typical size of coplanar resonators
(1~$\mathrm{mm^2}$). The fabrication method we developed easily fits into the
standard superconducting qubits fabrication process. We have obtained
capacitance per area 14~fF/$\mathrm{\mu m^2}$ and the internal quality factor
$\mathrm{1\times 10^3 - 8\times 10^3}$ at the single-photon level. Our results
show that such devices based on $\mathrm{Al/AlO_x/Al}$ capacitors could be
further applied to the qubit readout scheme, including resonators, filters,
amplifiers, as well as microwave metamaterials and innovative types of qubits,
such as $0-\pi$ qubit.",2203.09592v2
2022-03-21,Computation of eigenfrequency sensitivities using Riesz projections for efficient optimization of nanophotonic resonators,"Resonances are omnipresent in physics and essential for the description of
wave phenomena. We present an approach for computing eigenfrequency
sensitivities of resonances. The theory is based on Riesz projections and the
approach can be applied to compute partial derivatives of the complex
eigenfrequencies of any resonance problem. Here, the method is derived for
Maxwell's equations. Its numerical realization essentially relies on direct
differentiation of scattering problems. We use a numerical implementation to
demonstrate the performance of the approach compared to differentiation using
finite differences. The method is applied for the efficient optimization of the
quality factor of a nanophotonic resonator.",2203.11101v2
2022-03-23,Reflectivity spectra as absorption ones -- is it correct ?,"Approximate expressions for X-ray resonant and M\""ossbauer reflectivity in
the total external reflection region are developed for the limiting cases of a
semiinfinite mirror with a small resonant addition to the total susceptibility
and for the case of an ultrathin resonant layer. It is shown that in this
region the reflectivity can really show the linear dependence on the imaginary
part of resonant susceptibility, therefore in these cases the consideration of
reflectivity spectra (R-spectra) as absorption resonant spectra, undertaken in
several experimental works, can be justified. However, we have selected several
effects producing essential dispersive distortions of the R-spectrum shape even
for very small grazing angles. It has been shown that the dispersive
corrections to the R-spectrum shape are mostly essential if the nonresonant
absorption is relatively large. Model calculations demonstrate that the
quantitative spectroscopic information extracted from R-spectra by using the
software developed for absorption spectra can be inaccurate.",2203.12649v1
2022-03-29,Photon-pair blockade in a Josephson-photonics circuit with two nondegenerate microwave resonators,"We propose to generate photon-pair blockade in a Josephson-photonics circuit
that consists of a dc voltage-biased Josephson junction in series with a
superconducting charge qubit and two nondegenerate microwave resonators. The
two-level charge qubit is utilized to create anticorrelations of the charge
transport; that is, the simultaneous Cooper pair tunneling events are
inhibited. When the Josephson frequency matches the sum of resonance
frequencies of the charge qubit and the two resonators, we demonstrate that the
two resonators can release their energies in the form of antibunched pairs of
two strongly correlated photons. The present work provides a practical way for
producing a bright microwave source of antibunched photon pairs, with potential
applications ranging from spectroscopy and metrology to quantum information
processing.",2203.15373v1
2022-04-12,"Numerical Regge pole analysis of resonance structures in elastic, inelastic and reactive state-to-state integral cross sections","We present a detailed description of a FORTRAN code for evaluation of the
resonance contribution a Regge trajectory makes to the integral state-to-state
cross section (ICS) within a specified range of energies. The contribution is
evaluated with the help of the Mulholland formula [Macek et al (2004)] and its
variants [Sokolovski et al (2007); Sokolovski and Akhmatskaya (2011)]. Regge
pole positions and residues are obtained by analytically continuing S-matrix
element, evaluated numerically for the physical values of the total angular
momentum, into the complex angular momentum plane using the PADE II program
[Sokolovski et al (2011)]. The code decomposes an elastic, inelastic, or
reactive ICS into a structured, resonance, and a smooth, ""direct"", components,
and attributes observed resonance structure to resonance Regge trajectories.
The package has been successfully tested on several models, as well as the F +
H2->HF+H benchmark reaction. Several detailed examples are given in the text.",2204.05998v1
2022-04-20,Single SiGe Quantum Dot Emission Deterministically Enhanced in a High-Q Photonic Crystal Resonator,"We report the resonantly enhanced radiative emission from a single SiGe
quantum dot (QD), which is deterministically embedded into a bichromatic
photonic crystal resonator (PhCR) at the position of its largest modal electric
field by a scalable method. By optimizing our molecular beam epitaxy (MBE)
growth technique, we were able to reduce the amount of Ge within the whole
resonator to obtain an absolute minimum of exactly one QD, accurately
positioned by lithographic methods relative to the PhCR, and an otherwise flat,
a few monolayer thin, Ge wetting layer (WL). With this method, record quality
(Q) factors for QD-loaded PhCRs up to $Q\sim 10^5$ are achieved. A comparison
with control PhCRs on samples containing a WL but no QDs is presented, as well
as a detailed analysis of the dependence of the resonator-coupled emission on
temperature, excitation intensity, and emission decay after pulsed excitation.
Our findings undoubtedly confirm a single QD in the center of the resonator as
a potentially novel photon source in the telecom spectral range.",2204.09470v1
2022-05-04,Low-field Feshbach resonances and three-body losses in a fermionic quantum gas of $^{161}$Dy,"We report on high-resolution Feshbach spectroscopy on a degenerate,
spin-polarized Fermi gas of $^{161}$Dy atoms, measuring three-body
recombination losses at low magnetic field. For field strength up to 1\,G, we
identify as much as 44 resonance features and observe plateaus of very low
losses. For four selected typical resonances, we study the dependence of the
three-body recombination rate coefficient on the magnetic resonance detuning
and on the temperature. We observe a strong suppression of losses with
decreasing temperature already for small detunings from resonance. The
characterization of complex behavior of three-body losses of fermionic
$^{161}$Dy is important for future applications of this peculiar species in
research on atomic quantum gases.",2205.01943v2
2022-05-09,Coupling Spin Defects in Hexagonal Boron Nitride to Titanium Oxide Ring Resonators,"Spin-dependent optical transitions are attractive for a plethora of
applications in quantum technologies. Here we report on utilization of high
quality ring resonators fabricated from TiO2 to enhance the emission from
negatively charged boron vacancies in hexagonal Boron Nitride. We show that the
emission from these defects can efficiently couple into the whispering gallery
modes of the ring resonators. Optically coupled boron vacancy showed
photoluminescence contrast in optically detected magnetic resonance signals
from the hybrid coupled devices. Our results demonstrate a practical method for
integration of spin defects in 2D materials with dielectric resonators which is
a promising platform for quantum technologies.",2205.04031v1
2022-05-18,Graviton to Photon Conversion via Parametric Resonance,"We study the parametric resonance excitation of the electromagnetic field by
a gravitational wave. We show that there is narrow band resonance. For an
electromagnetic field in the vacuum the resonance occurs only in the second
band, and its strength is thus suppressed by two powers of amplitude of the
gravitational wave. On the other hand, in the case of an electromagnetic field
in a medium with the speed of light smaller than 1 (in natural units), there is
a band of Fourier modes which undergo resonance in the first band.",2205.08767v3
2022-05-18,Feshbach resonances in an ultracold $^{7}$Li-$^{133}$Cs Bose-Bose mixture,"We present a study of interspecies Feshbach resonances in ultracold
$^{7}$Li-$^{133}$Cs Bose-Bose mixtures. We locate ten interspecies resonances
in three different spin-state combinations. By comparing to coupled-channel
calculations, we assign six of the resonances to $s$-wave channels and the rest
to $p$-wave channels. We use the $s$-wave resonances to refine the ground-state
potentials of LiCs in the coupled-channel calculations and then obtain an
accurate characterization of the scattering and bound-state properties of the
mixtures. Our results will be useful for future experiments with ultracold
$^{7}$Li-$^{133}$Cs mixtures.",2205.08837v2
2022-06-01,Kinetic mass shifts of $ρ$(770) and $K^*$(892) in Au+Au reaction at $E_\mathrm{beam}=1.23~A$GeV,"We explore the properties of the last generation of $\rho$(770) and
$K^*$(892) resonances created in Au+Au reactions at E$_\mathrm{lab}=1.23$~AGeV
via the reconstruction in the hadronic channel using the UrQMD model. Such
resonance studies allow to obtain detailed information on the emission source
in such reactions in a complementary way to di-lepton or HBT studies. We
observe a freeze-out hierarchy and predict mass shifts for the $\rho$(770)
resonance ($\Delta m_\rho \approx -330$ MeV) and the $K^*$(892) resonance
($\Delta m_{K^*} \approx -30$ MeV). These mass shifts are related to the
regeneration cycles of each resonance species and are of purely kinetic origin.
Experimentally our predictions can be tested using the GSI-HADES experiment or
the lowest RHIC-BES energy.",2206.00410v2
2022-06-09,"A numerical study of the 1/2, 2/1 and 1/1 retrograde mean motion resonances in planetary systems","We present a numerical study on the stability of the 1/2, 2/1 and 1/1
retrograde mean motion resonances in the 3-body problem composed of a solar
mass star, a Jupiter mass planet and an additional body with zero mass
(elliptic restricted 3-body problem) or masses corresponding to either Neptune,
Saturn or Jupiter (planetary 3-body problem). For each system we obtain
stability maps using the n-body numerical integrator REBOUND and computing the
chaos indicator mean exponential growth factor of nearby orbits (MEGNO). We
show that families of periodic orbits exist in all configurations and they
correspond to the libration of either a single resonant argument or all
resonant arguments (fixed points). We compare the results obtained in the
elliptic restricted 3-body problem with previous results in the literature and
we show the differences and similarities between the phase space topology for
these retrograde resonances in the circular restricted, elliptic restricted and
planetary 3-body problems.",2206.04526v1
2022-06-11,Temperature dependence of Fano resonance in nanodiamonds synthesized at high static pressures,"Temperature dependence of Fano resonance, recently discovered in infra-red
(IR spectra of nanodiamonds synthesized from chloroadamantane at high static
pressures, is investigated. For the first time, marked variations of the
resonance parameteres are observed. On heating, the shape of the Fano resonance
changes considerably; the effect completely disappears above 350 C, but is
recovered after cooling to ambient conditions. Such behaviour implies that
assignment of the Fano effect to the surface transfer doping mechanism is not
very plausible for the studied samples. The resonance shape varies due to
strong temperature dependence of the difference of frequencies of IR-active
""bright"" and Raman-active ""dark"" modes of nanodiamond. The frequency of the
Raman ""dark"" mode is only weakly temperature-dependent.",2206.05484v1
2022-06-21,Resonance crossing of a charged body in a magnetized Kerr background: an analogue of extreme mass ratio inspiral,"We investigate resonance crossings of a charged body moving around a Kerr
black hole immersed in an external homogeneous magnetic field. This system can
serve as an electromagnetic analogue of a weakly non-integrable extreme mass
ratio inspiral (EMRI). In particular, the presence of the magnetic field
renders the conservative part of the system non-integrable in the Liouville
sense, while the electromagnetic self-force causes the charged body to
inspiral. By studying the system without the self-force, we show the existence
of an approximate Carter-like constant and discuss how resonances grow as a
function of the perturbation parameter. Then, we apply the electromagnetic
self-force to investigate crossings of these resonances during an inspiral.
Averaging the energy and angular momentum losses during crossings allows us to
employ an adiabatic approximation for them. We demonstrate that such adiabatic
approximation provides results qualitatively equivalent to the instantaneous
self-force evolution, which indicates that the adiabatic approximation may
describe the resonance crossing with sufficiently accuracy in EMRIs.",2206.10302v2
2022-06-21,"Effects of reactive, dissipative and rate-limited nonlinearity on the behaviour of superconducting resonator parametric amplifiers","We present a formalism for modelling parametric amplification by resonators
subject to rate-limited nonlinearity of mixed reactive/dissipative character,
with particular relevance to superconducting devices. The non-linearity is
assumed to be characterised by a single state parameter, which responds to
changes in the energy stored in the resonator with finite response time. We
show how the operating point and small signal amplification behaviour of the
pumped resonator can be calculated, characterised and optimised in terms of a
set of three dimensionless parameters. The formalism is then illustrated with a
simple, first-order, model nonlinearity and the implications for amplification
via quasiparticle generation in a superconductor discussed. Throughout we
describe how the parameters needed to characterise the device can be determined
experimentally from steady-state measurements. A key result of this paper is
that rate-limiting of a nonlinear mechanism does not preclude amplification,
although it does limit the bandwidth over which it may be achieved.",2206.10512v2
2022-06-22,Neolithic stone settlements as locally resonant metasurfaces,"We study the dynamic surface response of neolithic stone settlements obtained
with seismic ambient noise techniques near the city of Carnac in French
Brittany. Surprisingly, we find that menhirs (neolithic human size standing
alone granite stones) with an aspect ratio between 1 and 2 periodically
arranged atop a thin layer of sandy soil laid on a granite bedrock, exhibit
fundamental resonances in the range of 10 to 25 Hz. We propose an analogic
Kelvin-Voigt viscoelastic model that explains the origin of such low frequency
resonances. We further explore low frequency filtering effect with full wave
finite element simulations. Our numerical results confirm the bending nature of
fundamental resonances of the menhirs and further suggest additional resonances
of rotational and longitudinal nature in the frequency range 25 to 50 Hz. Our
study thus paves the way for large scale seismic metasurfaces consisting of
granite stones periodically arranged atop a thin layer of regolith over a
bedrock, for ground vibration mitigation in earthquake engineering.",2206.10825v1
2022-06-22,Resonance production in partial chemical equilibrium,"In high energy collisions, a dense, strongly interacting medium could be
created, the quark gluon plasma. In rapid expansion, from the soup of quarks
and gluons a gas of resonance and stable particles is formed at the chemical
freeze-out and after that, as the system cools down, the kinetic freeze-out
takes place and interaction between particles ceases. By measuring resonance
ratios one could get information about the dominant physical processes in the
intermediate temperature ranges, i.e. between the chemical and kinetic
freeze-out. These quantities are measured at RHIC and LHC energies. In the
present analysis we employ the hadron resonance gas model assuming partial
chemical equilibrium to characterize these measured data. We calculate the
ratios of several resonances to their stable counterpart and compare these
model calculations to available experimental data.",2206.11300v4
2022-06-28,Modal analysis of electromagnetic resonators: user guide for the MAN program,"All electromagnetic systems, in particular resonators or antennas, have
resonances with finite lifetimes. The associated eigenstates, also called
quasinormal modes, are essentially non-Hermitian and determine the optical
responses of the system. We introduce MAN (Modal Analysis of Nanoresonators), a
software with many open scripts, which computes and normalizes the quasinormal
modes of virtually any electromagnetic resonator, be it composed of dispersive,
anisotropic, or non-reciprocal materials. MAN reconstructs the scattered field
in the basis formed by the quasinormal modes of the resonator and provides a
transparent interpretation of the physics. The software is implemented in
MATLAB and has been developed over the past ten years. MAN features many
toolboxes that illustrate how to use the software for various emblematic
computations in low and high frequency regimes. A specific effort has been
devoted to interface the solver with the finite-element software COMSOL
Multiphysics. However, MAN can also be used with other frequency-domain
numerical solvers. This article introduces the program, summarizes the relevant
theoretical background. MAN includes a comprehensive set of classical models
and toolboxes that can be downloaded from the web.",2206.13886v3
2022-06-29,Second harmonic generation under doubly resonant lattice plasmon excitation,"Second harmonic generation is enhanced at the surface lattice resonance in
plasmonic nanoparticle arrays. We carried out a parametric investigation on
two-dimensional lattices composed of gold nanobars where the centrosymmetry is
broken at oblique incidence. We study the influence of the periodicity, the
incidence angle and the direction of the linear input polarization on the
second harmonic generation. Excitation of the surface lattice resonance either
at the fundamental or second harmonic wavelength, achieved by varying the
incidence angle, enhance the conversion efficiency. As a special case, we
demonstrate that both the wavelengths can be simultaneously in resonance for a
specific period of the lattice. In this double resonant case, maximum second
harmonic power is achieved.",2206.14433v2
2022-07-05,Adiabatic evolution due to the conservative scalar self-force during orbital resonances,"We calculate the scalar self-force experienced by a scalar point-charge
orbiting a Kerr black hole along $r\theta$-resonant geodesics. We use the
self-force to calculate the averaged rate of change of the charge's orbital
energy $\langle\dot{E}\rangle$, angular momentum $\langle\dot{L}_z\rangle$, and
Carter constant $\langle\dot{Q}\rangle$, which together capture the
leading-order adiabatic, secular evolution of the point-charge. Away from
resonances, only the dissipative (time anti-symmetric) components of the
self-force contribute to $\langle\dot{E}\rangle$, $\langle\dot{L}_z\rangle$,
and $\langle\dot{Q}\rangle$. We demonstrate, using a new numerical code, that
during $r\theta$ resonances conservative (time symmetric) scalar perturbations
also contribute to $\langle\dot{Q}\rangle$ and, thus, help drive the adiabatic
evolution of the orbit. Furthermore, we observe that the relative impact of
these conservative contributions to $\langle\dot{Q}\rangle$ is particularly
strong for eccentric 2:3 resonances. These results provide the first conclusive
numerical evidence that conservative scalar perturbations of Kerr spacetime are
non-integrable during $r\theta$ resonances.",2207.02224v2
2022-07-11,$^7$H ground state as a $^3$H+4n resonance,"We have investigated the possible existence of a $^7$H resonant state,
considered as a five-body system consisting of a $^3$H core with four valence
neutrons. To this aim, an effective n-$^3$H potential is constructed in order
to reproduce the low energy elastic neutron scattering on $^3$H phase shifts
and the $^5$H resonant ground state in terms of $^3$H-n-n system. The
variational Gaussian Expansion Method is used to solve the 5-body
Schr\""{o}dinger equation, while the resonant state parameters were estimated by
means of the stabilization method. We have not found any sign of a narrow low
energy resonance in the vicinity of $^3$H+4n threshold. However, we have
identified a very broad structure at $E_R\approx 9$ MeV above this threshold,
which corresponds to the $^7$H J$^{\pi}$=1/2$^+$ ground state. In the vicinity
of this state, we have also identified a broad structure corresponding to the
ground state of $^6$H isotope with quantum numbers $J^{\pi}=2^-$.",2207.04634v1
2022-07-14,Isoscalar Giant Resonances: Experimental Studies,"Giant resonances--highly collective, high-frequency oscillations of the
atomic nucleus--are the focus of this chapter. We discuss the isoscalar
excitations, where the protons and neutrons oscillate in phase, up to
angular-momentum transfers $L$ = 3. The procedures of experiments and data
analysis employed in extracting the strength distributions associated with
these resonances are discussed. The experimentally extracted strength
distributions are presented, along with information on the properties of these
resonances available to date. The effect of deformation of the nuclear ground
state on the resonance strength distributions is discussed. Furthermore, the
exciting opportunities being opened with the current and future availability of
rare isotope beams the world over are expounded.",2207.06785v1
2022-07-15,SS-HORSE Extension of the No-Core Shell Model: Application to Resonances in $^7{\mathrm He}$,"Theoretical ab initio studies of resonances in the unbound ${\rm^{7}He}$
nucleus are presented. We perform no-core shell model calculations with $NN$
interactions Daejeon16 and JISP16 and utilize the SS-HORSE method to calculate
the $S$ matrix for two-body channels $n{-}{\rm^{6}He}$ and
$n{-}{\rm^{6}He^{*}}$ with ${\rm^{6}He}$ respectively in the ground and excited
$2^{+}$ states as well as for the four-body democratic decay channel
${{\rm^{4}He}+n+n+n}$. The resonant energies and widths areobtained by
numerical location of the $S$-matrix poles. We describe all experimentally
known ${\rm^{7}He}$ resonances and suggest an interpretation of an observed
wide resonance of unknown spin-parity.",2207.07360v1
2022-07-18,Non-local scattering control in coupled resonator networks,"We demonstrate scattering control of Gaussian-like wave packets propagating
with constant envelope velocity and invariant waist through coupled resonator
optical waveguides (CROW) via an external resonator coupled to multiple sites
of the CROW. We calculate the analytical reflectance and transmittance using
standard scattering methods from waveguide quantum electrodynamics and show it
is possible to approximate them for an external resonator detuned to the CROW.
Our analytical and approximate results are in good agreement with numerical
simulations. We engineer various configurations using an external resonator
coupled to two sites of a CROW to show light trapping with effective
exponential decay between the coupling sites, wave packet splitting into two
pairs of identical Gaussian-like wave packets, and a non-local Mach-Zehnder
interferometer.",2207.08932v1
2022-07-19,Reminiscence of classical chaos in driven transmons,"Transmon qubits are ubiquitously used in superconducting quantum information
processor architectures. Strong drives are required to realize fast,
high-fidelity, gates and measurements, including parametrically activated
processes. Here, we show that even off-resonant drives, in regimes routinely
used in experiments, can cause strong modifications to the structure of the
transmon spectrum rendering a large part of it chaotic. Accounting for the full
nonlinear dynamics of the transmon in a Floquet-Markov formalism, we find that
these chaotic states, often neglected through the hypothesis that the
anharmonicity is weak, strongly impact the lifetime of the transmon's
computational states. In particular, we observe that chaos-assisted quantum
phase slips greatly enhance band dispersions. In the presence of a measurement
resonator, we find that approaching chaotic behavior correlates with strong
transmon-resonator hybridization, and an average resonator response centered on
the bare resonator frequency. These results lead to a photon number threshold
characterizing the appearance of chaos-induced quantum demolition effects
during strong-drive operations such as dispersive qubit readout. The phenomena
described here are expected to be present in all circuits based on
low-impedance Josephson-junctions.",2207.09361v2
2022-07-28,Resonance-to-bound transition of $^5$He in neutron matter and its analogy with heteronuclear Feshbach molecule,"We theoretically investigate the fate of a neutron-alpha $p$-wave resonance
in dilute neutron matter, which may be encountered in neutron stars and
supernova explosions. While $^5$He is known as a resonant state that decays to
a neutron and an alpha particle in vacuum, this unstable state turns into a
stable bound state in the neutron Fermi sea because the decay process is
forbidden by the Pauli-blocking effect of neutrons. Such a resonance-to-bound
transition assisted by the Pauli-blocking effect can be realized in cold atomic
experiments for a quantum mixture near the heteronuclear Feshbach resonance.",2207.13907v1
2022-08-08,A Coupled-Oscillators Model to Analyze the Interaction between a Quartz Resonator and Trapped Ions,"The novel application of a piezoelectric quartz resonator for the detection
of trapped ions has developed in the observation of the quartz-ions interaction
under non-equilibrium conditions, opening new perspectives for high-sensitive
motional frequency measurements of radioactive particles. Energized quartz
crystals have (long) constant-decay times in the order of milliseconds,
permitting the coherent detection of charged particles within short times. In
this publication we develop in detail a model governing the interaction between
trapped $^{40}$Ca$^+$ ions and a quartz resonator connected to a low-noise
amplifier. We apply this model to experimental data and extract relevant
information like the coupling constant $g=2\pi \times 1.449(2)$~Hz and the
ions' modified-cyclotron frequency in our 7-tesla Penning trap. The study on
the latter is specially important for the use of this resonator in precision
Penning-trap mass spectrometry. The improvement in sensitivity can be
accomplished by increasing the coupling constant through the quality factor of
the resonator. This can develop in the use of the hybrid quartz-ion system for
other applications.",2208.04437v1
2022-08-14,Triply-Resonant Sum Frequency Conversion with Gallium Phosphide Ring Resonators,"We demonstrate quasi-phase matched, triply-resonant sum frequency conversion
in 10.6-um-diameter integrated gallium phosphide ring resonators. A
small-signal, waveguide-to-waveguide power conversion efficiency of 8%/mW is
measured for conversion from telecom (1536 nm) and near infrared (1117 nm) to
visible (647 nm) wavelengths with an absolute power conversion efficiency of
6.3% measured at saturation pump power. For the complementary difference
frequency generation process, a single photon conversion efficiency of 7.2%/mW
from visible to telecom is projected for resonators with optimized coupling.
Efficient conversion from visible to telecom will facilitate long-distance
transmission of spin-entangled photons from solid-state emitters such as the
diamond NV center, allowing long-distance entanglement for quantum networks.",2208.06764v2
2022-08-15,High frequency torsional motion transduction using optomechanical coupled oscillators,"Using light to measure an object's motion is central to operating mechanical
sensors that probe forces and fields. Cavity optomechanical systems embed
mechanical resonators inside optical resonators. This enhances the sensitivity
of optomechanical measurements, but only if the mechanical resonator does not
spoil the properties of the optical cavity. For example, cavity optomechanical
detection of resonators made from optically absorbing materials, or whose
geometry does not possess suitable spatial symmetry, is challenging. Here we
demonstrate a system that overcomes challenges in measuring high-frequency
twisting motion of a nanodisk by converting them to vibrations of a photonic
crystal cavity. Optomechanical readout of the cavity then enables measurement
of the nanodisk's torsional resonances with sensitivity $5.1\times
10^{-21}-1.2\times 10^{-19}\,\text{Nm}/\sqrt{\text{Hz}}$ for a mechanical
frequency range of 5--800 MHz. The nanodisk can be outfitted with magnetic
nanostructures or metasurfaces without affecting the optical properties of the
cavity, making the system suitable for torque magnetometry and structured light
sensing.",2208.07454v2
2022-08-24,Hamiltonian theory of the crossing of the $2 Q_x -2 Q_y=0$ nonlinear coupling resonance,"In a recent paper, the adiabatic theory of Hamiltonian systems was
successfully applied to study the crossing of the linear coupling resonance,
$Q_x-Q_y=0$. A detailed explanation of the well-known phenomena that occur
during the resonance-crossing process, such as emittance exchange and its
dependence on the adiabaticity of the process was obtained. In this paper, we
consider the crossing of the resonance of nonlinear coupling $2 Q_x -2 Q_y = 0$
using the same theoretical framework. We perform the analysis using a
Hamiltonian model in which the nonlinear coupling resonance is excited and the
corresponding dynamics is studied in detail, in particular looking at the
phase-space topology and its evolution, in view of characterizing the emittance
exchange phenomena. The theoretical results are then tested using a symplectic
map. Thanks to this approach, scaling laws of general interest for applications
are derived.",2208.11519v1
2022-08-26,Resonance curves are perfect circles,"The ability to approach a physical phenomenon and grasp its major importance
is a remarkable quality of understanding. This paper presents a rather elegant
and novel way of looking at the resonance phenomenon, which among others shares
a common conceptual basis in various fields of physics. For the sake of
simplicity, the discussion will be restricted to the case of electric current
resonance in series RLC circuits.
  The mathematics of electric resonance is thus meticulously extended to the
extent that it ultimately unravels an invaluable relationship between the
current at a certain driving frequency and that at the resonance frequency.
Much further it gives rise to an elaborate correlation between any two driving
frequencies that give the same current.
  Arising from the previously mentioned relations, a new technique is devised,
a simple geometrical construction, that without running into tedious
calculations, allows the computation of the phase difference between the
current and the impressed voltage at any given frequency. Not to mention
another geometric utility, that is miraculously constructed to correlate any
frequency with its corresponding ``conjugate'' one, that allows the same
current in the circuit.",2208.12592v1
2022-08-28,Resonance mediated by fermions in kink-antikink collisions,"We investigate generalizations of the $\phi^4$ and sine-Gordon models,
including interactions with Dirac Fermions. We observe new resonance phenomena
by taking the fermion back-reaction into account. First, we show that the
vibrational mode responsible for the resonance structure of the $\phi^4$ model
has the same frequency as the energy of the fermion excited state when the
back-reaction becomes more significant. Second, we consider the sine-Gordon
model with the addition of a fermion field and find that a resonant structure
appears, despite the absence of a scalar vibrational mode. The vibrational
frequency of the mode responsible for the exchange mechanism is again the
energy of the fermion excited state. Therefore, we find a new type of resonant
energy exchange mechanism which is mediated by fermions.",2208.13261v2
2022-08-28,P-wave Sommerfeld enhancement near threshold: a simplified approach,"The calculation of P-wave Sommerfeld enhancement in processes with unstable
particles in the final state is known to be divergent. In a complete
description, where resonant (on-shell unstable particles) and non-resonant
contributions are included, it has been shown that results are finite. For most
beyond the Standard Model applications, these complete calculations are not
readily available. In this work, we are interested in the near-threshold region
and we consider only the resonant contribution. In this case, we provide a
simplified prescription to compute the P-wave Sommerfeld enhancement in the
narrow-width approximation of the unstable particle that directly eliminates
divergences. We show that we can define a finite resonant contribution without
the inclusion of the non-resonant processes in a way similar to the usual
S-wave Sommerfeld enhancement.",2208.13309v4
2022-08-29,Coupling of distant parts of pyrrole molecule through virtual and resonant states,"We experimentally show that the N-H bond cleavage in pyrrole molecule
following resonant electron attachment is allowed and controlled by the motion
of the atoms which are not dissociating, namely of the carbon-attached hydrogen
atoms. In order to interpret these findings, we have developed a method for
locating all resonant and virtual states of an electron-molecule system in the
complex plane, based on all-electron R-matrix scattering calculations. Mapping
these as a function of molecular geometry allows us to separate two
contributing dissociation mechanisms: a $\pi^*$ resonance formation inducing
strong bending deformations and a non-resonant $\sigma^*$ mechanism originating
in a virtual state. The coupling between the two mechanisms is enabled by the
out-of-plane motion of the C-H bonds and we show it must happen on an ultrafast
few-fs timescale.",2208.13539v1
2022-08-30,An excited atom interacting with a Chern insulator: towards a far-field resonant Casimir-Polder repulsion,"We consider the resonant Casimir-Polder interaction of an excited alkali-type
atom which has a single (electric dipole) transition with a Chern insulator.
The Chern insulator has a nonzero, time reversal symmetry breaking Hall
conductance, leading to an additional contribution to the resonant
Casimir-Polder interaction which depends on the coupling between the Hall
conductance and the circular polarization state of the atomic transition. We
find that the resonant Casimir-Polder shift can be significantly enhanced for
de-excitation frequencies near values associated with the van Hove
singularities of the Chern insulator. Furthermore, we find that the resonant
Casimir-Polder force can become monotonically decaying and repulsive for a
relatively large atom-surface distance, if the atomic dipole transition is
right circularly polarized and the Chern number of the Chern insulator is $-1$
or the atomic dipole transition is left circularly polarized and the Chern
number is $1$.",2208.14047v2
2022-09-08,Analysis of the exotic resonances in the systems $QQ\bar q\bar q$ and $Qq\bar Q\bar q$ with the extended recoupling model,"The phenomenon of a narrow peak X(3875), discovered recently by the LHCb in
the $D^*D$ system, and the absence of resonances in the $D_sD_s$ and
$D_s^*D_s^*$ systems is discussed within the new extended version of the
Recoupling Model, where the resonance is the result of infinite recoupling
transitions of confining strings between quarks and antiquarks.
  We show that existence of the resonance in the $D^*D$ and its absence in
$D_sD_s$ and $D_s^*D_s^*$ systems are the natural results of the Recoupling
Mechanism. The application of this mechanism to the $D\bar D^*$ system allows
to obtain the resonance $Z_c(3900)$ with larger width in agreement with
experimental data.",2209.03697v3
2022-09-12,Resonant Dynamics and the Instability of the Box Minkowski Model,"We revisit the box Minkowski model [Phys. Rev. Lett. 109, 221101 (2012)] and
provide a strong argument that, subject to the Dirichlet boundary condition, it
is unstable toward black hole formation for arbitrarily small generic
perturbations. Using weakly nonlinear perturbation theory, we derive the
resonant system, which compared to systems with the anti-de Sitter asymptotics,
has extra resonant terms, and study its properties, including conserved
quantities. We find that the generic solution of the resonant system becomes
singular in finite time. Surprisingly, the additional resonant interactions do
not significantly affect the singular evolution. Furthermore, we find that the
interaction coefficients take a relatively simple form, making this a
particularly attractive toy model of turbulent gravitational instability.",2209.05608v2
2022-09-20,Analysis of leaky modes or wavenumber resonances for the Rayleigh system in a half space,"We present a comprehensive analysis of wavenumber resonances or leaky modes
associated with the Rayleigh operator in a half space containing a
heterogeneous slab, being motivated by seismology. To this end, we introduce
Jost solutions on an appropriate Riemann surface, a boundary matrix and a
reflection matrix in analogy to the studies of scattering resonances associated
with the Schr\""{o}dinger operator. We analyze their analytic properties and
characterize the distribution of these wavenumber resonances. Furthermore, we
show that the resonances appear as poles of the meromorphic continuation of the
resolvent to the nonphysical sheets of the mentioned Riemann surface as
expected.",2209.09998v2
2022-09-23,Polariton-Assisted Resonance Energy Transfer Beyond Resonant Dipole-Dipole Interaction: A Transition Current Density Approach,"Using electric dipoles to describe light-matter interactions between two
entities is a conventional approximation in physics, chemistry, and material
sciences. However, the lack of material structures makes the approximation
inadequate when the size of an entity is comparable to the spatial extent of
electromagnetic fields or the distance between two entities. In this study, we
develop a unified theory of radiative and non-radiative resonance energy
transfer based on transition current density in a theoretical framework of
macroscopic quantum electrodynamics. The proposed theory allows us to describe
polariton-assisted resonance energy transfer between two entities with
arbitrary material structures in spatially dependent vacuum electric fields. To
demonstrate the generality of the proposed theory, we rigorously prove that our
theory can cover the main results of the transition density cube method and the
plasmon-coupled resonance energy transfer. We believe that this study opens a
promising direction for exploring light-matter interactions beyond the scope of
electric dipoles and provides new insights into material physics.",2209.11623v2
2022-10-05,Constant-power versus constant-voltage actuation in frequency sweeps for acoustofluidic applications,"Supplying a piezoelectric transducer with constant voltage or constant power
during a frequency sweep can lead to different results in the determination of
the acoustofluidic resonance frequencies, which are observed when studying the
acoustophoretic displacements and velocities of particles suspended in a
liquid-filled microchannel. In this work, three cases are considered: (1)
Constant input voltage into the power amplifier, (2) constant voltage across
the piezoelectric transducer, and (3) constant average power dissipation in the
transducer. For each case, the measured and the simulated responses are
compared, and good agreement is obtained. It is shown that Case 1, the simplest
and most frequently used approach, is largely affected by the impedance of the
used amplifier and wiring, so it is therefore not suitable for a reproducible
characterization of the intrinsic properties of the acoustofluidic device. Case
2 strongly favors resonances at frequencies yielding the lowest impedance of
the piezoelectric transducer, so small details in the acoustic response at
frequencies far from the transducer resonance can easily be missed. Case 3
provides the most reliable approach, revealing both the resonant frequency,
where the power-efficiency is the highest, as well as other secondary
resonances across the spectrum.",2210.02311v1
2022-10-15,Elastic Wave Scattering off a Single and Double Array of Periodic Defects,"Elastic waves scattering off a periodic single and double array of thin
cylindrical defects is considered for isotropic materials. An analytical
expression for the scattering matrix is obtained by means of the
Lippmann-Schwinger formalism and analyzed in the long wavelength limit using
Schloemilch series in order to obtain explicit expressions for the poles of the
scattering matrix. The latter is then used to prove that for a specific curve
in the space of physical and geometric parameters, the scattering is dominated
by resonances, and the width of the resonances in the shear mode parallel to
the cylinders has a global minimum in parameter space. This a feature is not
observed in similar photonic or acoustic systems. The resonances in shear and
compression modes that are coupled in the plane perpendicular to the cylinders
due to the normal traction boundary condition are studied for the double array.
The analytical dependence of the width of these resonances on physical and
geometrical parameters is exploited to prove the existence of resonances with
the vanishing width, known as Bound States in the Continuum (BSC). Spectral
characteristics of BSC are explicitly found in terms of the Bloch phase and
group velocities of elastic modes.",2210.08177v1
2022-11-03,Compositeness and several applications to exotic hadronic states with heavy quarks,"Several methods for studying the nature of a resonance are applied to
resonances recently discovered in the bottonomium and charmonium sectors. We
employ the effective-range expansion, the saturation of the width and
compositeness of a resonance, as well as direct fits to data. The latter stem
from generic $S$-matrix parameterization that account for relevant dynamical
features associated to channels that couple strongly in an energy region around
the resonance masses, in which their thresholds also lie. We report on results
obtained with these methods for the resonances $Z_b(10610)$, $Z_b(10650)$,
$Z_{cs}(3985)$, $Z_c(3900)$, $X(4020)$, $X(6900)$, $X(6825)$, and
$P_{cs}(4459)$.",2211.02090v1
2022-11-08,Spectral narrowing of a phonon resonance in time-domain sum-frequency spectroscopy,"Sum-frequency generation (SFG) spectroscopy provides a versatile method for
the investigation of non-centrosymmetric media and interfaces. Here, using
tunable picosecond infrared (IR) pulses from a free-electron laser, the
nonlinear optical response of 4H-SiC, a common polytype of silicon carbide, has
been probed in the frequency- and time-domain by infrared-visible vibrational
SFG spectroscopy. In the SFG spectra we observe a sharp resonance near the
longitudinal optical phonon frequency, arising from linear optical effects due
the epsilon-near-zero regime of the IR permittivity. In the time domain, the
build-up of the SFG intensity is linked to the free-induction decay of the
induced coherent IR polarization. When approaching the frequency of the phonon
resonance, a slower polarization dephasing is observed as compared to
off-resonant IR excitation. Thus, by introducing a temporal delay between the
IR and the visible up-conversion pulse we are able to demonstrate spectral
narrowing of the phonon SFG resonance, as corroborated by model calculations.",2211.04593v2
2022-11-09,"Trident pair creation by a train of laser pulses: Resonance, threshold, and carrier envelope phase effects","General formulation in the realm of strong-field quantum electrodynamics is
provided for a process that occurs in the presence of a train of laser pulses
and, in the tree level, is represented by a two-vertex Feynman diagram with
exchange of a virtual photon. A scheme of retrieving resonances in the
corresponding probability distributions is also formulated in these general
settings. While the presented formalism is applicable to a variety of processes
like electron-positron pair creation and annihilation, M\""oller scattering,
Bhabha scattering, etc., we illustrate it for a trident process. Specifically,
we consider electron-positron pair creation in the muon--laser-field
collisions. We demonstrate that the probability distributions exhibit
integrable singularities close to the threshold of pair creation. Also, a
variety of resonances is observed that originate from the poles of the Feynman
photon propagator. While those resonances are, in general, obscured by strong
quantum interferences, we show that they can be isolated by changing the
carrier envelope phase of the driving laser pulses. In that case, while
transformed into the Lorentz-Breit-Wigner shape profile, the resonance position
and width can be determined.",2211.04716v1
2022-11-12,Broadband Four-Wave Mixing Enhanced by Plasmonic Surface Lattice Resonance and Localized Surface Plasmon Resonance in an Azimuthally Chirped Grating,"Plasmonic enhancement of nonlinear light-matter interaction can be achieved
via dedicated optimization of resonant plasmonic modes that are spectrally
matched to the different wavelengths involved in the particular nonlinear
optical process. In this work, we investigate the generation and enhancement of
broadband four-wave mixing (FWM) in a plasmonic azimuthally chirped grating
(ACG). The azimuthally varying grating periodicity in an ACG offers a
well-defined channel to mediate the near field and the far field over a broad
range of wavelengths. However, the particular mechanism responsible for field
enhancement in such a platform depends on the interplay between the effects
manifested by both the groove geometry and the grating's periodicity. This work
delineates the collective contribution of groove geometry-dependent localized
surface plasmon resonance (LSPR) and periodicity-dependent plasmonic surface
lattice resonance (PSLR) over a broad range of wavelengths to bring into effect
the enhancement of broadband FWM in an ACG.",2211.06647v1
2022-11-14,Magnetic Feshbach resonances between atoms in $^2$S and $^3$P$_0$ states: mechanisms and dependence on atomic properties,"Magnetically tunable Feshbach resonances exist in ultracold collisions
between atoms in $^2$S and $^3$P$_0$ states, such as an alkali-metal atom
colliding with Yb or Sr in a clock state. We investigate the mechanisms of
these resonances and identify the terms in the collision Hamiltonian
responsible for them. They involve indirect coupling between the open and
closed channels, via intermediate channels involving atoms in $^3$P$_1$ states.
The resonance widths are generally proportional to the square of the magnetic
field and are strongly enhanced when the magnitude of the background scattering
length is large. For any given pair of atoms, the scattering length can be
tuned discretely by choosing different isotopes of the $^3$P$_0$ atom. For each
combination of an alkali-metal atom and either Yb or Sr, we consider the
prospects of finding an isotopic combination that has both a large background
scattering length and resonances at high but experimentally accessible field.
We conclude that $^{87}$Rb+Yb, Cs+Yb and $^{85}$Rb+Sr are particularly
promising combinations.",2211.07557v2
2022-11-15,Laser and Diffusion Driven Optimal Discrimination of Similar Quantum Systems in Resonator,"A method for solving the problem of efficient population transfer from the
ground to some excited state by available technical means (varying resonator
length) is proposed. We consider a mixture of similar quantum systems
distributed in a stationary gas flow in the resonator with variable resonator
length, which implements tailored laser field close to the optimal one. In
difference from previous works, in this work piezoelectric transducer (PZT; or
actuator) is used as mean of control to manipulate variable resonator length.
The external actions are optimized to selectively prepare different stationary
states of different species which are then separated using their diffusion with
rates which differ due to different masses. This system provides an example of
the general problem of optimizing states of distributed systems with stationary
gas flow with diffusion.",2211.08214v1
2022-12-05,Explanation of Y(4630) as hadronic resonant state,"After Y(4630) is discovered, theorists have given various explanations. We
find that if Y(4630) is interpreted as the D-wave resonant state of $\Lambda_c
\bar {\Lambda}_c$ system, the particle mass, decay width and all quantum
numbers are consistent with experimental observations. We use the Bonn
approximation to get the interaction potential of one boson exchange model,
then extend the complex scaling method (CSM) to calculate the bound and
resonant states. The results indicate that the $\Lambda_c \bar{\Lambda}_c$
system can form not only the bound state of S wave, but also the resonant state
of the high angular momentum, and the $^3D_1$ wave resonant state can explain
the structure of Y(4630) very well.",2212.02218v1
2022-12-06,Tomography of Feshbach Resonance States,"Feshbach resonances are fundamental to interparticle interactions and become
particularly important in cold collisions with atoms, ions, and molecules. Here
we present the detection of Feshbach resonances in a benchmark system for
strongly interacting and highly anisotropic collisions -- molecular hydrogen
ions colliding with noble gas atoms. The collisions are launched by cold
Penning ionization exclusively populating Feshbach resonances that span both
short- and long-range parts of the interaction potential. We resolved all final
molecular channels in a tomographic manner using ion-electron coincidence
detection. We demonstrate the non-statistical nature of the final state
distribution. By performing quantum scattering calculations on ab initio
potential energy surfaces, we show that the isolation of the Feshbach resonance
pathways reveals their distinctive fingerprints in the collision outcome.",2212.02828v2
2022-12-07,Dark and bright autoionizing states in resonant high harmonic generation: simulation via 1D helium model,"We study the role of dark and bright autoionizing states (AIS) in
photoionization and high harmonic generation (HHG) using a 1D helium model.
This model allows numerical integration of the time-dependent Schr\""odinger
equation beyond the singe-electron approximation completely taking into account
electronic correlation. We find the level structure of the system and the
spatial distribution of the electronic density for several states including
AIS. Studying the HHG efficiency as a function of the detuning from the
resonances with AIS we find the HHG enhancement lines. The shapes of these
lines are different from the corresponding Fano lines in the photoelectronic
spectra, in agreement with the experimental studies in helium. Moreover, we
simulate HHG under the conditions when the fundamental frequency is close to
the even-order multiphoton resonance with the dark AIS. We find the enhanced
generation of the neighbouring odd harmonics. The details of the enhancement
lines for these harmonics can be understood taking into account the temporal
delay between the emission of the non-resonant and resonant XUV; this delay is
defined by the AIS lifetime. Finally, our simulations show that the HHG
enhancement due to the dark and the bright AIS is comparable in the studied
system.",2212.03695v1
2022-12-13,Comparative study of the 1-2 exchange symmetries in neutrino frameworks with global and local validities,"A new picture ``one-resonance - one-symmetry'' has been proposed recently to
reveal nature of the reparametrization symmetry in neutrino oscillation in
matter and where it resides: Symmetry of $i \leftrightarrow j$ state-exchange
type exists at around a resonance with $i$ and $j$ being the states which
participate in the level crossing. Consistently, the 1-2 and 1-3 state exchange
symmetries are identified at around the solar and atmospheric resonances,
respectively, in the locally-valid frameworks. On the other hand, the Denton
{\it et al.} (DMP) perturbation theory, a globally-valid framework, has the 1-2
exchange symmetry which is akin to the one in the aforementioned
solar-resonance perturbation (SRP) theory. In our picture, the symmetry must be
associated with the resonance, not the framework, and if so these two 1-2
symmetries must be identical to each other. We conduct a comparative study of
the 1-2 symmetries possessed by SRP and DMP to confirm their identity. An
almost identity is verified, but in a highly nontrivial way.",2212.06320v3
2022-12-16,Nanomechanical resonators fabricated by atomic layer deposition on suspended 2D materials,"Atomic layer deposition (ALD), a layer-by-layer controlled method to
synthesize ultrathin materials, provides various merits over other techniques
such as precise thickness control, large area scalability and excellent
conformality. Here we demonstrate the possibility of using ALD growth on top of
suspended 2D materials to fabricate nanomechanical resonators. We fabricate ALD
nanomechanical resonators consisting of a graphene/MoS$_2$ heterostructure.
Using AFM indentation and optothermal drive, we measure their mechanical
properties including Young's modulus, resonance frequency and quality factor,
showing similar values as their exfoliated and chemical vapor deposited
counterparts. We also demonstrate the fabrication of nanomechanical resonators
by exfoliating an ALD grown NbS$_2$ layer. This study exemplifies the potential
of ALD techniques to produce high-quality suspended nanomechanical membranes,
providing a promising route towards high-volume fabrication of future
multilayer nanodevices and nanoelectromechanical systems.",2212.08449v1
2022-12-26,On phase at a resonance in slow-fast Hamiltonian systems,"We consider a slow-fast Hamiltonian system with one fast angular variable (a
fast phase) whose frequency vanishes on some surface in the space of slow
variables (a resonant surface). Systems of such form appear in the study of
dynamics of charged particles in inhomogeneous magnetic field under influence
of a high-frequency electrostatic waves. Trajectories of the averaged over the
fast phase system cross the resonant surface. The fast phase makes $\sim \frac
{1}{\varepsilon}$ turns before arrival to the resonant surface ($\varepsilon$
is a small parameter of the problem). An asymptotic formula for the value of
the phase at the arrival to the resonance was derived earlier in the context of
study of charged particle dynamics on the basis of heuristic considerations
without any estimates of its accuracy. We provide a rigorous derivation of this
formula and prove that its accuracy is $O(\sqrt \varepsilon)$ (up to a
logarithmic correction). Numerics indicate that this estimate for the accuracy
is optimal.",2212.13293v1
2022-12-28,Electronic-vibrational resonance does not alter steady-state transport in natural light-harvesting systems,"Oscillations in time-dependent 2D electronic spectra appear as evidence of
quantum coherence in light-harvesting systems related to electronic-vibrational
resonant interactions. Nature, however, takes place in a non-equilibrium
steady-state, so the relevance of these arguments to the natural process is
unclear. Here we examine the role of intramolecular vibrations in the
non-equilibrium steady-state of photosynthetic dimers in the natural scenario
of incoherent light excitation. It is found that vibrations resonant with the
energy difference between exciton states do not increase the quantum yield nor
the imaginary part of the intersite coherence that is relevant for transport
compared with non-resonant vibrations in the natural non-equilibrium steady
state. That is, the vibration-electronic resonance interaction does not alter
energy transport under natural incoherent-light excitation conditions.",2212.13690v1
2023-01-05,Generalized Dicke model and gauge-invariant master equations for two atoms in ultrastrongly-coupled cavity quantum electrodynamics,"We study a generalization of the well-known Dicke model, using two dissimilar
atoms in the regime of ultrastrongly coupled cavity quantum electrodynamics.
Our theory uses gauge invariant master equations, which yields consistent
results in either of the standard multipolar and Coulomb gauges, including
system-bath interactions for open cavity systems. We first show how a second
atom can be treated as a sensor atom to measure the output spectrum from a
single atom in the ultrastrong-coupling regime, and compare results with the
quantum regression theorem, explaining when they can be different. We then
focus on the case where the second atom is also ultrastrongly coupled to the
cavity, but with different parameters from those of the first atom, which
introduces complex coupling effects and additional resonances and spectral
features. In particular, we show multiple resonances in the cavity spectra that
are visible off-resonance, which cannot be seen when the second atom is
on-resonance with the rest of the system. We also observe clear anti-crossing
features particularly pronounced for when the second atom tunes through
resonance.",2301.02127v2
2023-01-09,Average localization of resonances on the quantum repeller,"There has been a very recent surge in the interest on the localization
properties of resonances associated to partially open (scattering) systems,
which are of great relevance when studying resonant cavities such as those used
in microlasers. Very recently, it has been found that no localization is
present in a scaled form of these states. Moreover, a new kind of scarring on
structures different from periodic orbits is described for non scaled
resonances. In this paper, we analyze the localization of a distribution
function corresponding to the quantum LR representation -- based on the non
unitary evolution operator decomposition into left and right resonances -- for
the partially open quantum tribaker map, a paradigmatic system. We find
localization on the shortest periodic orbits. Also, scaled states present
enhancements that could not be associated to periodic orbits and that become
more evident when looking at the LR representation. These findings open the
door for new perspectives on recent theoretical developments.",2301.04135v2
2023-02-03,Tunable Resonance and Electron-Phonon Coupling in Layered MoS2,"Resonance Raman scattering, a very effective and sensitive technique for
atomically thin semiconducting transition metal dichalcogenide, can be used to
observe the phonons from the entire Brillouin zone. In addition to the
significance of resonance effect on the Raman spectrum it may also be used to
probe the electron-phonon coupling. Our study is devoted to understand the
phonons in layered MoS2, especially for very low frequency range (i.e. below
100 cm-1), as a function of temperature under the resonance effect.
Understanding the phonon-phonon and electron-phonon coupling and the effects of
temperature on the Raman spectrum are the central points of the present study.
We observe the anomalous softening and broadening of a very low frequency
phonon mode P3 (~34 cm-1) at low temperature ( i.e below 150 K). We attributed
the observed anomalous trend in frequency and linewidth of this low frequency
phonon to the electron-phonon coupling. Furthermore, our work also highlights
the temperature induced tuning of resonance condition via understanding the
intensity of phonon modes as a function of temperature.",2302.01662v1
2023-02-16,Nanoscale Imaging of Super-High-Frequency Microelectromechanical Resonators with Femtometer Sensitivity,"Implementing microelectromechanical system (MEMS) resonators calls for
detailed microscopic understanding of the devices, such as energy dissipation
channels, spurious modes, and imperfections from microfabrication. Here, we
report the nanoscale imaging of a freestanding super-high-frequency (3 ~ 30
GHz) lateral overtone bulk acoustic resonator with unprecedented spatial
resolution and displacement sensitivity. Using transmission-mode microwave
impedance microscopy, we have visualized mode profiles of individual overtones
and analyzed higher-order transverse spurious modes and anchor loss. The
integrated TMIM signals are in good agreement with the stored mechanical energy
in the resonator. Quantitative analysis with finite-element modeling shows that
the noise floor is equivalent to an in-plane displacement of 10 fm/sqrt(Hz) at
room temperatures, which can be further improved under cryogenic environments.
Our work contributes to the design and characterization of MEMS resonators with
better performance for telecommunication, sensing, and quantum information
science applications.",2302.08004v1
2023-02-28,Observation of Feshbach resonances in an ${}^{167}$Er-${}^6$Li Fermi-Fermi mixture,"We present our experimental investigation of the interspecies Feshbach
spectrum in a mixture of ${}^{167}$Er($F = 19/2, m_F = -19/2$)-${}^6$Li($F =
1/2, m_F = 1/2$) atoms in the microkelvin temperature regime. These
temperatures are achieved by means of sympathetic cooling with ${}^{174}$Yb as
a third species. Interspecies Feshbach resonances are then identified by
investigation of the Er-Li inelastic collisional properties for magnetic fields
up to 800 G. Numerous narrow resonances as well as six resonances with widths
above 1 G could be identified. It is these broader resonances that hold much
promise for interesting future investigations of, for exmample, novel
superfluid states and Efimov states in large mass-imbalanced, all-fermionic
two-component systems.",2302.14253v1
2023-03-06,Two Distinct Charge Orders in Infinite-layer PrNiO2+δ revealed by Resonant X-ray Diffraction,"A broken translation symmetry has recently been revealed in infinite-layer
nickelates, which has piqued considerable interest in its origin and relation
to superconductivity, as well as in its comparison to charge order in cuprates.
Here, by performing resonant x-ray scattering measurements in thin films of
infinite-layer PrNiO2+{\delta}, we find that the superlattice reflection at the
Ni L3 absorption edge differs considerably from that at the Pr M5 resonance in
their dependence on energy, temperature, and local symmetry, indicating they
are two distinct charge orders despite the same in-plane wavevectors. These
dissimilarities might be related to the excess oxygen dopants, considering that
the resonant reflections were observed in an incompletely reduced
PrNiO2+{\delta} film. In addition, our azimuthal analysis suggests that the
oxygen ligands should play a pivotal role in the charge modulation revealed at
the Ni L3 resonance.",2303.02865v2
2023-03-09,P-even and -odd asymmetries on $^{117}$Sn at the vicinity of the p-resonance E$_\mathrm{p}$=1.33 eV,"A self consistent description of angular correlations in neutron induced
reactions is required for quantitative analysis of parity violating (PV) and
time reversal invariance violating (TRIV) effects in neutron nucleus
scattering. The 1.33 eV p-wave compound resonance in $^{117}$Sn is one of the
few p-wave resonances where enough measurements have been performed to allow a
nontrivial test of the internal consistency of the theory. We present the
results of a global analysis of the several different asymmetries and angular
distribution measurements in ($n, \gamma$) reactions on the 1.33 eV p-wave
resonance in $^{117}$Sn conducted over the last few decades. We show that the
compound resonance mixing theory can give an internally consistent description
of all observations made in this system to date within the experimental
measurement errors. We also confirm the conclusions of previous analyses that a
subthreshold resonance in $^{117}$Sn dominates correlations related to s-p
mixing, and discuss the implications of these results for future searches for
TRIV in this system.",2303.05425v1
2023-03-11,A numerical study of fourth- and fifth-order retrograde mean motion resonances in planetary systems,"We present a numerical study on the stability of all fourth- and fifth-order
retrograde mean motion resonances (1/3, 3/1, 1/4, 4/1, 2/3, and 3/2) in the
3-body problem composed of a solar mass star, a Jupiter mass planet, and an
additional body with zero mass (elliptic restricted problem) or masses
corresponding to either Neptune, Saturn, or Jupiter (planetary problem). The
fixed point families exist in all cases and are identified through libration of
all resonant angles simultaneously. In addition, configurations with libration
of a single resonant angle were also observed. Our results for the elliptic
restricted 3-body problem are in agreement with previous studies of retrograde
periodic orbits, but we also observe new families not previously reported. Our
results regarding stable resonant retrograde configurations in the planetary
3-body problem could be applicable to extra-Solar systems.",2303.06479v1
2023-03-15,Defeating Broken Symmetry with Doping: Symmetric Resonant Tunneling in Noncentrosymetric Heterostructures,"Resonant tunneling transport in polar heterostructures is intimately
connected to the polarization fields emerging from the geometric Berry-phase.
In these structures, quantum confinement results not only in a discrete
electronic spectrum, but also in built-in polarization charges exhibiting a
broken inversion symmetry along the transport direction. Thus, electrons
undergo highly asymmetric quantum interference effects with respect to the
direction of current flow. By employing doping to counter the broken symmetry,
we deterministically control the resonant transmission through GaN/AlN resonant
tunneling diodes and experimentally demonstrate the recovery of symmetric
resonant tunneling injection across the noncentrosymmetric double-barrier
potential.",2303.08404v1
2023-03-22,"Temperature dependence of 7Li NMR relaxation rates in Li3InCl6, Li3YCl6, Li1.48Al0.48Ge1.52(PO4)3 and LiPS5Cl","Inorganic solid-state battery electrolytes show high ionic conductivities and
enable the fabrication of all solid-state batteries. In this work, we present
the temperature dependence of spin-lattice relaxation time (T1), spin-spin
relaxation time (T2), and resonance linewidth of the 7Li nuclear magnetic
resonance (NMR) for four solid-state battery electrolytes (Li3InCl6 (LIC),
Li3YCl6 (LYC), Li1.48Al0.48Ge1.52(PO4)3 (LAGP) and LiPS5Cl (LPSC)) from 173 K
to 403 K at a 7Li resonance frequency of 233 MHz, and from 253 K to 353 K at a
7Li resonance frequency of 291 MHz. Additionally, we measured the spin-lattice
relaxation rates at an effective 7Li resonance frequency of 133 kHz using a
spin-locking pulse sequence in the temperature range of 253 K to 353 K. In
LPSC, the 7Li NMR relaxation is consistent with the Bloembergen-Pound-Purcell
(BPP) theory of NMR relaxation of dipolar nuclei. In LIC, LYC and LAGP, the BPP
theory does not describe the NMR relaxation rates for the temperature range and
frequencies of our measurements. The presented NMR relaxation data assists in
providing a complete picture of Li diffusion in the four solid-state battery
electrolytes.",2303.12953v1
2023-03-23,Resonant instabilities mediated by drag and electrostatic interactions in laboratory and astrophysical dusty plasmas,"Dusty plasmas are known to support a diverse range of instabilities,
including both generalizations of standard plasma instabilities and ones caused
by effects specific to dusty systems. It has been recently demonstrated that a
novel broad class of streaming instabilities, termed resonant drag
instabilities (RDIs), can be attributed to a particular resonance phenomenon,
manifested by defective eigenvalues of the linearized dust/fluid system. In
this work, it is demonstrated that this resonance phenomenon is not unique to
RDIs and can be used as a framework to understand a wider range of
instabilities, termed resonant instabilities. Particular attention is given to
the filamentary ionization instability seen in laboratory dusty plasmas and to
the two-stream instability. It is shown that, due to the commonalities in
underlying physics between the dust-ion-acoustic two-stream instability and the
acoustic RDI, these instabilities should be relevant in strongly overlapping
regimes in astrophysical dusty plasmas. It is proposed that a similar overlap
in the experimental accessibility of these modes (and of the filamentary
instability) allows for the possibility of experimental investigation in the
laboratory of complex and astrophysically relevant instability dynamics.",2303.13640v2
2023-03-30,Multiresonant metasurfaces for arbitrarily-broadband pulse chirping and dispersion compensation,"We show that ultrathin metasurfaces with a specific multiresonant response
can enable simultaneously arbitrarily-strong and arbitrarily-broadband
dispersion compensation, pulse (de-)chirping and compression or broadening.
This breakthrough overcomes the fundamental limitations of both conventional
non-resonant approaches (bulky) and modern singly-resonant metasurfaces
(narrowband) for quadratic phase manipulations of electromagnetic signals. The
required non-uniform trains of resonances in the electric and magnetic sheet
conductivities that completely control phase delay, group delay, and chirp, are
rigorously derived and the limitations imposed by fundamental physical
constraints are thoroughly discussed. Subsequently, a practical, truncated
approximation by finite sequences of physically-realizable linear resonances is
constructed and the associated error is quantified. By appropriate spectral
ordering of the resonances, operation can be achieved either in transmission or
reflection mode, enabling full space coverage. The proposed concept is not
limited to dispersion compensation, but introduces a generic and powerful
ultrathin platform for the spatio-temporal control of broadband real-world
signals with a myriad of applications in modern optics, microwave photonics,
radar and communication systems.",2303.17214v1
2023-04-03,Improved constraints on minimum length models with a macroscopic low loss phonon cavity,"Many theories that attempt to formulate a quantum description of gravity
suggest the existence of a fundamental minimum length scale. A popular method
for incorporating this minimum length is through a modification of the
Heisenberg uncertainty principle known as the generalised uncertainty principle
(GUP). Experimental tests of the GUP applied to composite systems can be
performed by searching for the induced frequency perturbations of the modes of
mechanical resonators, thus constraining the degree of minimum length in
certain scenarios. In this work previous constraints made with mechanical
resonators are improved upon by three orders of magnitude, via the utilisation
of a cryogenic quartz bulk acoustic wave resonator. As well as purely
mechanical resonant modes; hybrid electromechanical anti-resonant modes are
investigated, and shown to be sensitive to the same GUP induced effects.",2304.00688v2
2023-04-03,Characterizing multi-mode nonlinear dynamics of nanomechanical resonators,"Mechanical nonlinearities dominate the motion of nanoresonators already at
relatively small oscillation amplitudes. Although single and coupled
two-degrees-of-freedom models have been used to account for experimentally
observed nonlinear effects, it is shown that these models quickly deviate from
experimental findings when multiple modes influence the nonlinear response.
Here, we present a nonlinear reduced-order modelling methodology based on FEM
simulations for capturing the global nonlinear dynamics of nanomechanical
resonators. Our physics-based approach obtains the quadratic and cubic
nonlinearities of resonators over a wide frequency range that spans 70 MHz. To
qualitatively validate our approach, we perform experiments on a graphene
nanodrum driven opto-thermally and show that the model can replicate diverse
ranges of nonlinear phenomena, including multi-stability, parametric resonance,
and different internal resonances without considering any empirical nonlinear
fitting parameters. By providing a direct link between microscopic geometry,
material parameters, and nonlinear dynamic response, we clarify the physical
significance of nonlinear parameters that are obtained from fitting the
dynamics of nanomechanical systems, and provide a route for designing devices
with desired nonlinear behaviour.",2304.01419v1
2023-04-05,Multiphoton resonance band and Bloch-Siegert shift in a bichromatically driven qubit,"We study the resonance and dynamics of a qubit exposed to a strong aperiodic
bichromatic field by using a periodic counter-rotating hybridized rotating wave
(CHRW) Hamiltonian, which is derived from the original Hamiltonian with the
unitary transformations under a reasonable approximation and enables the
application of the Floquet theory. It is found that the consistency between the
CHRW results and numerically exact generalized-Floquet-theory (GFT) results in
the valid regime of the former while the widely used rotating-wave
approximation (RWA) breaks down. We illustrate that the resonance exhibits band
structure and the Bloch-Siegert shifts induced by the counter-rotating
couplings of the bichromatic field become notable at the multiphoton resonance
band. In addition, the CHRW method is found to have a great advantage of
efficiency over the GFT approach particularly in the low beat-frequency case
where the latter converges very slowly. The present CHRW method provides a
highly efficient way to calculate the resonance frequency incorporating the
Bloch-Siegert shift and provides insights into the effects of the
counter-rotating couplings of the bichromatic field in the strong-driving
regimes.",2304.02676v1
2023-04-09,Beyond 5 GHz excitation of a ZnO-based high-overtone bulk acoustic resonator on SiC substrate,"This work describes the fabrication and characterization of an
Au/ZnO/Pt-based high-overtone bulk acoustic resonator (HBAR) on SiC substrates.
We evaluate its microwave characteristics comparing with Si substrates for
micro-electromechanical applications. Dielectric magnetron sputtering and an
electron beam evaporator are employed to develop highly c-axis-oriented ZnO
films and metal electrodes. The crystal structure and surface morphology of
post-growth layers have been characterized using X-ray diffraction (XRD),
atomic force microscopy (AFM), and scanning electron microscopy (SEM)
techniques. HBAR on SiC substrate results in multiple longitudinal bulk
acoustic wave resonances up to 7 GHz, with the strongest excited resonances
emerging at 5.25 GHz. The value of f.Q (Resonance frequency * Quality factor)
parameter obtained using a novel Q approach method for HBAR on SiC substrate is
4.1 * 10^13 Hz which, to the best of our knowledge, is the highest among all
reported values for specified ZnO-based devices.",2304.04286v1
2023-04-10,Wave reflections and resonance in a Mach 0.9 turbulent jet,"This work aims to provide a more complete understanding of the resonance
mechanisms that occur in turbulent jets at high subsonic Mach number, as shown
by Towne et al. (2017). Resonance was suggested by that study to exist between
upstream- and downstream-travelling guided waves. Five possible resonance
mechanisms were postulated, each involving different families of guided waves
that reflect in the nozzle exit plane and a number of downstream turning
points. But the study did not show which of these mechanisms are active in the
flow. In this work, the waves underpinning resonance are identified via a
biorthogonal projection of the Large Eddy Simulation data on eigenbases
provided by locally parallel linear stability analysis. Two of the scenarios
postulated by Towne et al. (2017) are thus confirmed to exist in the turbulent
jet data. The reflection-coefficients in the nozzle exit and turning-point
planes are, furthermore, identified.",2304.04436v1
2023-04-14,Nonergodic Brownian oscillator: High-frequency response,"We consider a Brownian oscillator whose coupling to the environment may lead
to the formation of a localized normal mode. For lower values of the
oscillator's natural frequency, $\omega\le\omega_c$, the localized mode is
absent and the unperturbed oscillator reaches thermal equilibrium. For higher
values of $\omega>\omega_c$, when the localized mode is formed, the unperturbed
oscillator does not thermalize but rather evolves into a nonequilibrium
cyclostationary state. We consider the response of such an oscillator to an
external periodic force. Despite the coupling to the environment, the
oscillator shows the unbounded resonance (with the response linearly increasing
with time) when the frequency of the external force coincides with the
frequency of the localized mode. An unusual resonance (``quasi-resonance"")
occurs for the oscillator with the critical value of the natural frequency
$\omega=\omega_c$, which separates thermalizing (ergodic) and non-thermalizing
(nonergodic) configurations. In that case the resonance response increases with
time sublinearly, which can be interpreted as a resonance between the external
force and the incipient localized mode.",2304.07371v1
2023-04-15,PT-symmetric feedback induced linewidth narrowing,"Narrow linewidth is a long-pursuing goal in precision measurement and
sensing. We propose a parity-time (PT )-symmetric feedback method to narrow the
linewidths of resonance systems. By using a quadrature measurement-feedback
loop, we transform a dissipative resonance system into a PT-symmetric system.
Unlike the conventional PT-symmetric systems which typically require two or
more modes, here the PT-symmetric feedback system contains only a single
resonance mode, which greatly extends the scope of applications. The method
enables remarkable linewidth narrowing and enhancement of measurement
sensitivity. We illustrate the concept in a thermal ensemble of atoms,
achieving a 48-fold narrowing of the magnetic resonance linewidth. By applying
the method in magnetometry, we realize a 22-times improvement of the
measurement sensitivity. This work opens the avenue for studying non-Hermitian
physics and high-precision measurements in resonance systems with feedback.",2304.07475v2
2023-04-18,Bounds on the Quality-factor of Two-phase Quasi-static Metamaterial Resonators and Optimal Microstructure Designs,"Material resonances are fundamentally important in the field of
nano-photonics and optics. So it is of great interest to know what are the
limits to which they can be tuned. The bandwidth of the resonances in materials
is an important feature which is commonly characterized by using the quality
(Q) factor. We present bounds on the quality factor of two-phase quasi-static
metamaterial resonators evaluated at a given resonant frequency by introducing
an alternative definition for the Q-factor in terms of the complex effective
permittivity of the composite material. Optimal metamaterial microstrcuture
designs achieving points on these bounds are presented. The most interesting
optimal microstructure, is a limiting case of doubly coated ellipsoids that
attains points on the lower bound. We also obtain bounds on Q for three
dimensional, isotropic, and fixed volume fraction two-phase quasi-static
metamaterials. Some almost optimal isotropic microstructure geometries are
identified.",2304.09315v1
2023-04-24,Investigating the impact of extra resonance states in the van der Waals Hadron Resonance Gas Model,"We investigate, in addition to the experimentally established hadrons, how
the inclusion of extra resonance states, through the Hagedorn mass spectrum
(HS) or Quark Model (QM) predicated states, affects the thermodynamic and
transport quantities of the hadronic system in the van der Waals hadron
resonance gas (VDWHRG) model. We found that the VDWHRG model with the HS
provides the most accurate description of the lattice QCD results, both at zero
and finite chemical potential. Moreover, the inclusion of these extra states
has a significant impact on the van der Waals (VDW) parameters, which, in turn,
affect the thermodynamic and transport quantities as well as the likely
position of the liquid-gas phase transition critical point in the QCD phase
diagram. Additionally, we infer that there is a strong correlation between the
van der Waals parameters and the chemical potential. Overall, our study sheds
light on the importance of considering extra resonance states and proper tuning
of the VDW parameters in the VDWHRG model to enhance the accuracy and
reliability of the model in the context of Ultra-relativistic heavy-ion
physics.",2304.11914v1
2023-04-26,Flexible Integration of Gigahertz Nanomechanical Resonators with a Superconducting Microwave Resonator using a Bonded Flip-Chip Method,"We demonstrate strong coupling of gigahertz-frequency nanomechanical
resonators to a frequency-tunable superconducting microwave resonator via a
galvanically bonded flip-chip method. By tuning the microwave resonator with an
external magnetic field, we observe a series of hybridized microwave-mechanical
modes and report coupling strengths of $\sim {15}~\text{MHz}$ at cryogenic
temperatures. The demonstrated multi-chip approach provides flexible rapid
characterization and simplified fabrication, and could potentially enable
coupling between a variety of quantum systems. Our work represents a step
towards a plug-and-play architecture for building more complex hybrid quantum
systems.",2304.13592v1
2023-05-03,$Σ$ Resonances from a Neural Network-based Partial Wave Analysis on $K^-p$ Scattering,"We implement a convolutional neural network to study the $\Sigma$ hyperons
using experimental data of the $K^-p\to\pi^0\Lambda$ reaction. The averaged
accuracy of the NN models in resolving resonances on the test data sets is
${\rm 98.5\%}$, ${\rm 94.8\%}$ and ${\rm 82.5\%}$ for one-, two- and
three-additional-resonance case. We find that the three most significant
resonances are $1/2^+$, $3/2^+$ and $3/2^-$ states with mass being ${\rm
1.62(11)~GeV}$, ${\rm 1.72(6)~GeV}$ and ${\rm 1.61(9)~GeV}$, and probability
being $\rm 100(3)\%$, $\rm 72(24)\%$ and $\rm 98(52)\%$, respectively, where
the errors mostly come from the uncertainties of the experimental data. Our
results support the three-star $\Sigma(1660)1/2^+$, the one-star
$\Sigma(1780)3/2^+$ and the one-star $\Sigma(1580)3/2^-$ in PDG. The ability of
giving quantitative probabilities in resonance resolving and numerical
stability make NN potentially a life-changing tool in baryon partial wave
analysis, and this approach can be easily extended to accommodate other
theoretical models and/or to include more experimental data.",2305.01852v1
2023-05-05,Accommodating the H$(650)$ in the HEFT,"Loss of unitarity in an effective field theory is often cured by the
appearance of dynamical resonances, revealing the presence of new degrees of
freedom. These resonances may manifest themselves when suitable unitarization
techniques are implemented in the effective theory, which in the
scalar-isoscalar channel require making use of the coupled-channel formalism.
Conversely, experimental detection of a resonance may provide interesting
information on the couplings and constants of the relevant effective theory. By
applying the systematical procedure developed in previous works, we will
attempt to accommodate a possible scalar resonance with mass around $650$ GeV
for which there is preliminary evidence at the LHC in the vector boson fusion
channel. The results are interesting: the resonance can be accommodated within
the experimentally allowed range of next-to-leading order coefficients in the
HEFT but in a rather non-trivial manner. Interestingly, its width and
production cross section turn out to agree with the tentative experimental
results.",2305.03622v1
2023-05-09,Investigation of unbound hydrogen isotopes with the Gamow shell model,"Although they are part of the lightest nuclei, the hydrogen isotopes are not
well understood both experimentally and theoretically. Indeed, besides deuteron
and triton, all known hydrogen isotopes are resonances of complex structure.
Even more elusive is 7H, which may have been observed experimentally and has
been claimed to be a narrow resonance. Nevertheless, even its existence is
controversial, and its theoretical study is difficult due to both its unbound
character and large number of interacting valence nucleons. It is then the
object of this paper to theoretically study the hydrogen isotopes {4-7}H with
the Gamow shell model, which is, up to our knowledge, the first direct
calculation of unbound resonance hydrogen isotopes up to 7H. As the Gamow shell
model includes both continuum coupling and inter-nucleon correlations, useful
information can be obtained about poorly known unbound hydrogen isotopes. Our
present calculations indicate that {4,6}H ground states are fairly broad
resonances, whereas those of {5,7}H are narrow, which is in accordance with
current experimental data. The results then suggest that, in particular, {5,7}H
should be more heavily studied, as they might well be among the most narrow
neutron resonances of the light nuclear chart.",2305.05414v1
2023-05-11,Genesis of chimera patterns through self-induced stochastic resonance,"Noise induced order in excitable systems has diverse manifestations, such as
coherence resonance (CR) and stochastic resonance. In this context a less
explored phenomenon is self-induced stochastic resonance (SISR). Unlike CR,
SISR may arise away from the bifurcation threshold and the properties of the
induced oscillations depend upon both the noise intensity and the time-scale
separation factor. In this work, we report a new chimera pattern in a network
of coupled excitable units, namely the self-induced stochastic resonance
chimera or SISR-chimera that originates from the SISR phenomenon. We explore
the detailed dynamics of the SISR-chimera in the parameter space using proper
quantitative measures. We have found that unlike CR chimera, the SISR-chimera
pattern strongly depends upon the ratio of time scale and noise intensity.
Therefore, this type of chimera pattern can be induced even for a tiny noise
intensity if the time scale separation of the activator and inhibitor is large
enough.",2305.06824v1
2023-05-22,Integrated microcavity optomechanics with a suspended photonic crystal mirror above a distributed Bragg reflector,"Increasing the interaction between light and mechanical resonators is an
ongoing endeavor in the field of cavity optomechanics. Optical microcavities
allow for boosting the interaction strength through their strong spatial
confinement of the optical field. In this work, we follow this approach by
realizing a sub-wavelength-long, free-space optomechanical microcavity on-chip
fabricated from an (Al,Ga)As heterostructure. A suspended GaAs photonic crystal
mirror is acting as a highly reflective mechanical resonator, which together
with a distributed Bragg reflector forms an optomechanical microcavity. We
demonstrate precise control over the microcavity resonance by change of the
photonic crystal parameters. The interplay between the microcavity mode and a
guided resonance of the photonic crystal modifies the cavity response and
results in a stronger dynamical backaction on the mechanical resonator compared
to conventional optomechanical dynamics.",2305.13511v1
2023-05-26,Symmetric resonance based integrators and forest formulae,"We introduce a unified framework of symmetric resonance based schemes which
preserve central symmetries of the underlying PDE. We extend the resonance
decorated trees approach introduced in arXiv:2005.01649 to a richer framework
by exploring novel ways of iterating Duhamel's formula, capturing the dominant
parts while interpolating the lower parts of the resonances in a symmetric
manner. This gives a general class of new numerical schemes with more degrees
of freedom than the original scheme from arXiv:2005.01649. To encapsulate the
central structures we develop new forest formulae that contain the previous
class of schemes and derive conditions on their coefficients in order to obtain
symmetric schemes. These forest formulae echo the one used in Quantum Field
Theory for renormalising Feynman diagrams and the one used for the
renormalisation of singular SPDEs via the theory of Regularity Structures.
These new algebraic tools not only provide a nice parametrisation of the
previous resonance based integrators but also allow us to find new symmetric
schemes with remarkable structure preservation properties even at very low
regularity.",2305.16737v2
2023-05-27,"Measurement of the $\mathrm{^{25}Al(d,n)^{26}Si}$ reaction and impact on the $\mathrm{^{25}Al(p,γ)^{26}Si}$ reaction rate","The $\mathrm{^{25}Al(p,\gamma)^{26}Si}$ reaction is part of a reaction
network with impact on the observed galactic $^{26}$Al abundance. A new
determination of the proton strength of the lowest $\ell=0$ proton-resonance in
$^{26}$Si is required to more precisely calculate the thermal reaction rate. To
this end, the $\mathrm{^{25}Al(d,n)^{26}Si}$ proton-transfer reaction is
measured in inverse kinematics using an in-flight radioactive beam at the
RESOLUT facility. Excitation energies of the lowest $^{26}$Si proton resonances
are measured and cross sections are determined for the lowest $\ell=0$
resonance associated with the $3^{+}_{3}$ state at 5.92(2) MeV. Coupled
reaction channels (CRC) calculations using FRESCO are performed to extract the
$\ell=0$ spectroscopic factor for the $3^{+}_{3}$ state. The proton width for
the $3^{+}_{3}$ state in $^{26}$Si is determined to be $\Gamma_{p}$=2.19(45) eV
and the $(p,\gamma)$ resonance strength for the $3^{+}_{3}$ state is extracted
as 26(10) meV. This resonance dominates the $\mathrm{^{25}Al(p,\gamma)^{26}Si}$
reaction rate above 0.2 GK.",2305.17511v1
2023-05-31,A Guide to Diagnosing Colored Resonances at Hadron Colliders,"We present a comprehensive study on how to distinguish the properties of
heavy dijet resonances at hadron colliders. A variety of spins, chiral
couplings, charges, and QCD color representations are considered.
Distinguishing the different color representations is particularly difficult at
hadron colliders. To determine the QCD color structure, we consider a third jet
radiated in a resonant dijet event. We show that the relative rates of
three-jet versus two-jet processes are sensitive to the color representation of
the resonance. We also show analytically that the antennae radiation pattern of
soft radiation depends on the color structure of dijet events and develops an
observable that is sensitive to the antennae patterns. Finally, we exploit a
Convolutional Neural Network with Machine Learning techniques to differentiate
the radiation patterns from different colored resonances and find encouraging
results to discriminate them. We demonstrate our results numerically at a 14
TeV LHC, and the methodology presented here should be applicable to other
future hadron colliders.",2306.00079v1
2023-06-15,Potential and Feshbach $s$-wave resonances in coupled atomic collision channels,"We discuss $s$-wave scattering in an atomic binary collision with two coupled
channels, tunable by an external magnetic field, one channel open and the other
closed for the incident energies considered. The analysis is performed with a
stylized model of square-well potentials. This simplification allows for a
pedagogically thorough discussion of the different scattering resonances that
appear in coupled channels. One of the them, the potential resonances at
vanishing energy, occur as a bound state of the coupled system emerges, in
turned tuned at a very precise value of the external field. The other
resonances, described by Feshbach theory, occur when the incident energy is
near a bound state of the closed channel, as if it were decoupled from the open
channel. These resonances exist for values of the external field above a
particular threshold value. Besides the potential intrinsic value of this study
in a quantum mechanics course, as the analysis can be performed with minor
numerical calculations, it is also an aid for the understanding of current
research advances in the exciting field of ultracold gases.",2306.09236v1
2023-06-30,Controlling photons by phonons via giant atom in a waveguide QED setup,"We investigate the single photon scattering in a phonon-photon hybrid system
in the waveguide QED scheme. In our consideration, an artificial giant atom,
which is dressed by the phonons in a surface acoustic wave resonator, interacts
with a coupled resonator waveguide (CRW) nonlocally via two connecting sites.
Together with the interference effect by the nonlocal coupling, the phonon
serves as a controller to the transport of the photon in the waveguide. On the
one hand, the coupling strength between the giant atom and the surface acoustic
wave resonator modulates the width of the transmission valley or window in the
near resonant regime. On the other hand, the two reflective peaks induced by
the Rabi splitting degrade into a single one when the giant atom is large
detuned from the surface acoustic resonator, which implies an effective
dispersive coupling. Our study paves the way for the potential application of
giant atoms in the hybrid system.",2306.17444v1
2023-07-04,Superconducting Non-Reciprocity Based on Time-Modulated Coupled-Resonator Systems,"We present a unified approach for designing a diverse range of
superconducting non-reciprocal components, including circulators, isolators,
and uni-directional amplifiers, based on temporally-modulated coupled resonator
networks. Our method leverages standard SQUID-based resonators as building
blocks, arranged in various configurations such as series-coupled,
wye-connected, and lattice-coupled resonators, to realize a wide range of
on-chip non-reciprocal devices. Our theoretical studies demonstrated the
effectiveness of the proposed approach, achieving circulators and isolators
with near-zero insertion losses and isolation greater than 20 dB, and
directional amplifiers with forward gain exceeding 10 dB and reverse isolation
greater than 20 dB. To validate our findings, we implemented and measured a
series-coupled three-resonator superconducting isolator using a single-layer
superconducting process. At a base temperature of 20 mK, our device exhibited
insertion loss of 1.3 dB in the forward direction, and isolation of up to 25 dB
at the center frequency and greater than 15 dB across a bandwidth of 250 MHz in
the reverse direction. Our approach promises to enable the design of a broad
range of high-performance non-reciprocal devices for superconducting circuits.",2307.01853v1
2023-07-14,Three-Dimensional Fully Metallic Dual Polarization Frequency Selective Surface Design Using Coupled-Resonator Circuit Information,"This work employs a new approach to analyze coupled-resonator circuits to
design and manufacture a fully metallic dual polarization frequency selective
surface (FSS). The proposed filtering structure is composed of a series of unit
cells with resonators fundamentally coupled along the z-direction and then
repeated periodically in the xy-plane. The fully metallic cascaded unit cell is
rigorously analyzed within an infinite periodic environment as a
coupled-resonator electromagnetic (EM) circuit. The convenient design of the EM
resonators makes it possible to push the evanescent EM field through the
metallic structure in the desired frequency band for both polarizations. An FSS
prototype is manufactured and measured, and good agreement is found between the
simulation results and the final prototype.",2307.07224v1
2023-07-18,Moir{é} pattern assisted geometric resonant tunneling in disordered twisted bilayer graphene,"We investigate the mesoscopic transport through a twisted bilayer graphene
(TBG) consisting of a clean graphene nanoribbon on the bottom and a disordered
graphene disc on the top. We show that, with strong top-layer disorder the
transmission through such a device shows a sequence of resonant peaks with
respect to the rotation angle $\theta$, where at the resonance angles
$\theta_c$ the disc region contains one giant hexagonal moir{\'e} supercell. A
further investigation shows that the value of $\theta_c$ shows negligible
dependence on the disorder strength, the Fermi energy, and the shape
distortion, indicating the resonance is a robust geometric feature of the
moir{\'e} supercell. We explain this geometric resonance based on the bound
states formed inside the moir{\'e} supercell, with their averaged local density
of states dominating at the AA stacking region while minimizing at the AB
stacking region. By increasing the interlayer distance, the peak becomes less
pronounced which further confirms the role of interlayer coupling. The results
presented here suggest a new mechanism to tune the quantum transport signal
through the twist angle in disordered moir{\'e} systems.",2307.09587v1
2023-07-20,Resonance phenomena in a nanomagnet coupled to a Josephson junction under external periodic drive,"We investigate resonance phenomena in a system consisting of a nanomagnet
coupled to a Josephson junction under external periodic drive. The coupling in
the system leads to appearance of additional resonance peaks whose properties
depend on the periodic signal and Josephson junction dynamics. In the linear
regime, we derive an analytical description of the resonance phenomena which is
then confirmed by numerical simulations. This analytical method is universal
and can be also applied to Josephson junctions with anomalous phase shift in
current phase relation. This work provides a new method of controlling the
resonances of hybrid structures, which may be interesting for applications.",2307.10989v1
2023-07-20,Sweeping Secular Resonances and Giant Planet Inclinations in Transition Discs,"The orbits of some warm Jupiters are highly inclined (20$^\circ$-50$^\circ$)
to those of their exterior companions. Comparable misalignments are inferred
between the outer and inner portions of some transition discs. These large
inclinations may originate from planet-planet and planet-disc secular
resonances that sweep across interplanetary space as parent discs disperse. The
maximum factor by which a seed mutual inclination can be amplified is of order
the square root of the angular momentum ratio of the resonant pair. We identify
those giant planet systems (e.g. Kepler-448 and Kepler-693) which may have
crossed a secular resonance, and estimate the required planet masses and
semimajor axes in transition discs needed to warp their innermost portions
(e.g. in CQ Tau). Passage through an inclination secular resonance could also
explain the hypothesized large mutual inclinations in apsidally-orthogonal warm
Jupiter systems (e.g. HD 147018).",2307.11021v2
2023-07-20,Azimuthal patterns in planetesimal circumstellar disks,"Ways of formation of azimuthal resonant patterns in circumstellar
planetesimal disks with planets are considered. Our analytical estimates and
massive numerical experiments show that the disk particles that initially
reside in zones of low-order mean-motion resonances with the planet may
eventually concentrate into potentially observable azimuthal patterns. The
structuring process is rapid, usually taking ~100 orbital periods of the
planet. It is found that the relative number of particles that retain their
resonant position increases with decreasing the mass parameter $\mu$ (the ratio
of masses of the perturbing planet and the parent star), but a significant
fraction of the particle population is always removed from the disk due to
accretion of the particles onto the star and planet, as well as due to their
transition to highly elongated and hyperbolic orbits. Expected radio images of
azimuthally structured disks are constructed. In the considered models,
azimuthal patterns associated with the 2:1 and 3:2 resonances are most clearly
manifested; observational manifestations of the 1:2 and 2:3 resonances are also
possible.",2307.11188v1
2023-07-27,Pursuit of paired dijet resonances in the Run 2 dataset with ATLAS,"New particles with large masses that decay into hadronically interacting
particles are predicted by many models of physics beyond the Standard Model. A
search for a massive resonance that decays into pairs of dijet resonances is
performed using 140 fb$^{-1}$ of proton$-$proton collisions at $\sqrt{s}=13$
TeV recorded by the ATLAS detector during Run 2 of the Large Hadron Collider.
Resonances are searched for in the invariant mass of the tetrajet system, and
in the average invariant mass of the pair of dijet systems. A data-driven
background estimate is obtained by fitting the tetrajet and dijet invariant
mass distributions with a four-parameter dijet function and a search for local
excesses from resonant production of dijet pairs is performed. No significant
excess of events beyond the Standard Model expectation is observed, and upper
limits are set on the production cross-sections of new physics scenarios.",2307.14944v2
2023-07-29,Design of Cost-Effective Nanoacoustic Devices based on Mesoporous Thin Films,"Gigahertz acoustic resonators have the potential to advance data processing
and quantum communication. However, they are expensive and lack responsiveness
to external stimuli, limiting their use in sensing applications. In contrast,
low-cost nanoscale mesoporous materials, known for their high surface-to-volume
ratio, have shown promise in various applications. We recently demonstrated
that mesoporous silicon dioxide (SiO2) and titanium dioxide (TiO2) thin layers
can support coherent acoustic modes in the 5 to 100 GHz range. In this study,
we propose a new method for designing tunable acoustic resonators using
mesoporous thin films on acoustic distributed Bragg reflectors. By infiltrating
the pores with different chemicals, the material's properties could be altered
and achieve tunability in the acoustic resonances. We present four device
designs and use simulations to predict resonators with Q-factors up to 1000. We
also observe that the resonant frequency and intensity show a linear response
to relative humidity, with a tunability of up to 60 %. Our platform offers a
unique opportunity to design cost-effective nanoacoustic sensing and
reconfigurable optoacoustic nanodevices.",2307.15843v1
2023-07-31,Gating ferromagnetic resonance of magnetic insulators by superconductors via modulating electric-field radiation,"We predict that ferromagnetic resonance in insulating magnetic film with
inplane magnetization radiates electric fields polarized along the
magnetization with opposite amplitudes at two sides of the magnetic insulator,
which can be modulated strongly by adjacent superconductors. With a single
superconductor adjacent to the magnetic insulator this radiated electric field
is totally reflected with a $\pi$-phase shift, which thereby vanishes at the
superconductor side and causes no influence on the ferromagnetic resonance.
When the magnetic insulator is sandwiched by two superconductors, this
reflection becomes back and forth, so the electric field exists at both
superconductors that drives the Meissner supercurrent, which in turn shifts
efficiently the ferromagnetic resonance. We predict an ultrastrong coupling
between magnons in the yttrium iron garnet and Cooper pairs in NbN with the
frequency shift achieving tens of percent of the bare ferromagnetic resonance.",2307.16472v2
2023-08-18,Coherence resonance for time-averaged measures,"Noise can induce time order in the dynamics of nonlinear dynamical systems.
For example, coherence resonance occurs in various neuron models driven by a
noise. In studies of coherence resonance, ensemble-averaged measures of the
coherence are often used. In the present study, we examine coherence resonance
for time-averaged measures. For the examination, we use a Hodgkin-Huxley neuron
model driven by a constant current and a noise. We firstly show that for large
times, the neuron is in a stationary state irrespective of initial conditions
of the neuron. We then show numerical evidence that in the stationary state, a
given noise sample path uniquely determines the dynamics of the neuron. We then
present numerical evidence suggesting that time-averaged coherence measures of
the dynamics is independent of noise sample paths and is equal to
ensemble-averaged coherence measures. On the basis of this property, we show
that coherence resonance is not only a phenomenon related to ensemble-averaged
measures but also a phenomenon that holds for time-averaged measures.",2308.09342v2
2023-08-19,"Stochastic resonance in a model of a periodically driven DNA : Multiple transitions, scaling and sequence dependence","We numerically study stochastic resonance in the unzipping of a model
double-stranded DNA by a periodic force. We observe multiple peaks in
stochastic resonance in the output signal as the driving force frequency is
varied for different force amplitudes, temperature, chain length, and chain
heterogeneity. Multiple peaks point to the existence of multiple stable and
metastable states, which correspond to dynamical states of partially zipped and
unzipped conformations and transitions between them. We quantify such
transitions by looking at the time evolution of the fraction of bound base
pairs. We obtain phase diagrams in the force amplitude-temperature plane both
in the resonance frequency of the primary peak and the output signal at the
peak value. We further obtain an excellent scaling behavior of the output
signal for changing lengths of the DNA. Resonance behavior is also affected by
chain heterogeneity as it depends strongly on which base pair the periodic
forcing is applied.",2308.09914v1
2023-08-24,Semi-analytical Framework for Modeling Strong Coupling of Quantum Emitters in Electromagnetic Resonators,"We present a semi-analytical framework for studying interactions between
quantum emitters and general electromagnetic resonators. The method relies on
the Lippmann-Schwinger equation to calculate the complex resonance frequencies
of the coupled system based only on a single calculation for the
electromagnetic resonator without the quantum emitter and with no fitting
parameters. This is in stark contrast to standard approaches in the literature,
in which the properties of the coupled system are fitted from calculated
spectra. As an application example, we consider a recent dielectric cavity
design featuring deep subwavelength confinement of light. We find the expected
anti-crossing of the emitter and cavity resonance frequencies, and comparing to
independent reference calculations, we find an extraordinary quantitative
agreement with a relative error below one part in ten thousand. In order to
unambiguously connect with the Jaynes-Cummings model, we derive an explicit
expression relating the classical description of the emitter, as modeled by a
spherical inclusion with a Lorentzian material response, to the dipole moment
of the corresponding quantum optical model. The combined framework therefore
enables classical calculations to be used for evaluating the coupling strength
entering quantum optical theories in a transparent way.",2308.12957v1
2023-08-28,R-matrix calculations for opacities: III. Plasma broadening of autoionizing resonances,"A general formulation is employed to study and quantitatively ascertain the
effect of plasma broadening of {\it intrinsic} autoionizing (AI) resonances in
photoionization cross sections. In particular, R-matrix data for iron ions
described in the previous paper in the RMOP series (RMOP-II, hereafter RMOP2)
are used to demonstrate underlying physical mechanisms due to electron
collisions, ion microfields (Stark), thermal Doppler effects, core excitations,
and free-free transitions. Breit-Pauli R-matrix (BPRM) cross section for the
large number of bound levels of Fe ions are considered, 454 levels of Fe~XVII,
1,184 levels of Fe~XVIII and 508 levels of Fe~XIX. Following a description of
theoretical and computational methods, a sample of results is presented to show
significant broadening and shifting of AI resonances due to {\it Extrinsic}
plasma broadening as a function of temperature and density. Redistribution of
AI resonance strengths broadly preserves their integrated strengths as well as
the naturally {\it intrinsic} asymmetric shapes of resonance complexes which
are broadened, smeared and flattened, eventually dissolving into the bound-free
continua.",2308.14870v1
2023-09-06,Enhanced Q-factor and effective length silicon photonics filter utilizing nested ring resonators,"In this study, we investigate a novel design of an on-chip nested coupled
ring resonator to enhance the quality factor and the effective length of the
resonator. The configuration consists of an open ring and racetrack resonator,
with lengths of 340 {\mu}m and 184.4 {\mu}m, respectively, with a coupling
ratio of 97/3. In this regard, the proposed nested cavity has been
experimentally characterized and compared with a single cavity ring resonator.
Our results show a significant improvement in the quality factor by a factor of
four. This improvement in performance opens up exciting new possibilities for
state-of-the-art applications, such as compact optical sensors and delay lines.
Our proposed design represents a significant advancement in the field of
integrated optics, and we believe that it has the potential to enable a broad
range of applications in the future.",2309.02775v1
2023-09-06,Millimeter Wave Thin-Film Bulk Acoustic Resonator in Sputtered Scandium Aluminum Nitride,"This work reports a millimeter wave (mmWave) thin-film bulk acoustic
resonator (FBAR) in sputtered scandium aluminum nitride (ScAlN). This paper
identifies challenges of frequency scaling sputtered ScAlN into mmWave and
proposes a stack and new fabrication procedure with a sputtered Sc0.3Al0.7N on
Al on Si carrier wafer. The resonator achieves electromechanical coupling (k2)
of 7.0% and quality factor (Q) of 62 for the first-order symmetric (S1) mode at
21.4 GHz, along with k2 of 4.0% and Q of 19 for the third-order symmetric (S3)
mode at 55.4 GHz, showing higher figures of merit (FoM, k2xQ) than reported
AlN/ScAlN-based mmWave acoustic resonators. The ScAlN quality is identified by
transmission electron microscopy (TEM) and X-ray diffraction (XRD), identifying
the bottlenecks in the existing piezoelectric-metal stack. Further improvement
of ScAlN/AlN-based mmWave acoustic resonators calls for better crystalline
quality from improved thin-film deposition methods.",2309.03135v1
2023-09-07,Hyperpolarisation of nuclear spins: polarisation blockade,"Efficient hyperpolarisation of nuclear spins via optically active defect
centers, such as the nitrogen vacancy (NV) center in diamond, has great
potential for enhancing NMR based quantum information processing and nanoscale
magnetic resonance imaging. Recently, pulse-based protocols have been shown to
efficiently transfer optically induced polarisation of the electron defect spin
to surrounding nuclear spins -- at particular resonant pulse intervals. In this
work, we investigate the performance of these protocols, both analytically and
experimentally, with the electronic spin of a single NV defect. We find that
whenever polarisation resonances of nuclear spins are near-degenerate with a
`blocking' spin, which is single spin with stronger off-diagonal coupling to
the electronic central spin, they are displaced out of the central resonant
region -- without, in general, significant weakening of the resonance. We
analyse the underlying physical mechanism and obtain a closed form expression
for the displacement. We propose that spin blocking represents a common but
overlooked effect in hyperpolarisation of nuclear spins and suggest solutions
for improved protocol performance in the presence of (naturally occurring)
blocking nuclear spins.",2309.03761v1
2023-09-08,Search for the $Zγ$ decay mode of new high-mass resonances in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector,"This letter presents a search for narrow, high-mass resonances in the
$Z\gamma$ final state with the $Z$ boson decaying into a pair of electrons or
muons. The $\sqrt{s}=13$ TeV $pp$ collision data were recorded by the ATLAS
detector at the CERN Large Hadron Collider and have an integrated luminosity of
140 fb$^{-1}$. The data are found to be in agreement with the Standard Model
background expectation. Upper limits are set on the resonance production cross
section times the decay branching ratio into $Z\gamma$. For spin-0 resonances
produced via gluon-gluon fusion, the observed limits at 95% confidence level
vary between 65.5 fb and 0.6 fb, while for spin-2 resonances produced via
gluon-gluon fusion (or quark-antiquark initial states) limits vary between 77.4
(76.1) fb and 0.6 (0.5) fb, for the mass range from 220 GeV to 3400 GeV.",2309.04364v2
2023-09-21,Simultaneous Resonant and Broadband Detection for Dark Sectors,"Electromagnetic resonant systems, such as cavities or LC circuits, have
emerged as powerful detectors for probing ultralight boson dark matter and
high-frequency gravitational waves. However, the limited resonant bandwidth of
conventional single-mode resonators, imposed by quantum fluctuations,
necessitates numerous scan steps to cover broad unexplored frequency regions.
The incorporation of multiple auxiliary modes can realize a broadband detector
while maintaining a substantial signal response. The broadened sensitive width
can be on the same order as the resonant frequency, encompassing several orders
of the source frequency for heterodyne detection, where a background cavity
mode transitions into another. Consequently, our approach enables significantly
deeper exploration of the parameter space within the same integration time
compared to single-mode detection.",2309.12387v1
2023-10-02,Stability and Dynamics of Atom-Molecule Superfluids Near a Narrow Feshbach Resonance,"The recent observations of a stable molecular condensate emerging from a
condensate of bosonic atoms and related ``super-chemical"" dynamics have raised
an intriguing set of questions. Here we provide a microscopic understanding of
this unexpected stability and dynamics in atom-molecule superfluids; we show
one essential element behind these phenomena is an extremely narrow Feshbach
resonance in $^{133}$Cs at 19.849G. Comparing theory and experiment we
demonstrate how this narrow resonance enables the dynamical creation of a large
closed-channel molecular fraction superfluid, appearing in the vicinity of
unitarity. Theoretically the observed superchemistry (\textit{i.e.}, Bose
enhanced reactions of atoms and molecules), is found to be assisted by the
formation of Cooper pairs of bosonic atoms having opposite momenta.
Importantly, this narrow resonance opens the possibility to explore the quantum
critical point of a molecular Bose superfluid and related phenomena which would
not be possible near a more typically broad Feshbach resonance.",2310.01639v1
2023-10-05,Optical Properties and Behavior of Whispering Gallery Mode Resonators in Complex Microsphere Configurations: Insights for Sensing and Information Processing Applications,"Whispering gallery mode (WGM) resonators are garnering significant attention
due to their unique characteristics and remarkable properties. When integrated
with optical sensing and processing technology, WGM resonators offer numerous
advantages, including compact size, high sensitivity, rapid response, and
tunability. This paper comprehensively investigates the optical properties and
behavior of WGMs in complex microsphere resonator configurations. The findings
underscore the potential of WGMs in sensing applications and their role in
advancing future optical information processing. The study explores the impact
of configuration, size, excitation, polarization, and coupling effects on the
WGMs properties. The paper provides crucial insights and valuable guidance for
designing and optimizing microsphere resonator systems, enabling their
realization for practical applications.",2310.03931v1
2023-10-18,Physics-informed Neural Network for Acoustic Resonance Analysis,"This study proposes the physics-informed neural network (PINN) framework to
solve the wave equation for acoustic resonance analysis. ResoNet, the
analytical model proposed in this study, minimizes the loss function for
periodic solutions, in addition to conventional PINN loss functions, thereby
effectively using the function approximation capability of neural networks,
while performing resonance analysis. Additionally, it can be easily applied to
inverse problems. Herein, the resonance in a one-dimensional acoustic tube was
analyzed. The effectiveness of the proposed method was validated through the
forward and inverse analyses of the wave equation with energy-loss terms. In
the forward analysis, the applicability of PINN to the resonance problem was
evaluated by comparison with the finite-difference method. The inverse
analysis, which included the identification of the energy loss term in the wave
equation and design optimization of the acoustic tube, was performed with good
accuracy.",2310.11804v2
2023-11-02,Fast ZZ-Free Entangling Gates for Superconducting Qubits Assisted by a Driven Resonator,"Engineering high-fidelity two-qubit gates is an indispensable step toward
practical quantum computing. For superconducting quantum platforms, one
important setback is the stray interaction between qubits, which causes
significant coherent errors. For transmon qubits, protocols for mitigating such
errors usually involve fine-tuning the hardware parameters or introducing
usually noisy flux-tunable couplers. In this work, we propose a simple scheme
to cancel these stray interactions. The coupler used for such cancellation is a
driven high-coherence resonator, where the amplitude and frequency of the drive
serve as control knobs. Through the resonator-induced-phase (RIP) interaction,
the static ZZ coupling can be entirely neutralized. We numerically show that
such a scheme can enable short and high-fidelity entangling gates, including
cross-resonance CNOT gates within 40 ns and adiabatic CZ gates within 140 ns.
Our architecture is not only ZZ free but also contains no extra noisy
components, such that it preserves the coherence times of fixed-frequency
transmon qubits. With the state-of-the-art coherence times, the error of our
cross-resonance CNOT gate can be reduced to below 1e-4.",2311.01332v1
2023-11-07,Latched Detection of Zeptojoule Spin Echoes with a Kinetic Inductance Parametric Oscillator,"When strongly pumped at twice their resonant frequency, non-linear resonators
develop a high-amplitude intracavity field, a phenomenon known as parametric
self-oscillations. The boundary over which this instability occurs can be
extremely sharp and thereby presents an opportunity for realizing a detector.
Here we operate such a device based on a superconducting microwave resonator
whose non-linearity is engineered from kinetic inductance. The device indicates
the absorption of low-power microwave wavepackets by transitioning to a
self-oscillating state. Using calibrated wavepackets we measure the detection
efficiency with zeptojoule energy wavepackets. We then apply it to measurements
of electron spin resonance, using an ensemble of $^{209}$Bi donors in silicon
that are inductively coupled to the resonator. We achieve a latched-readout of
the spin signal with an amplitude that is five hundred times greater than the
underlying spin echoes.",2311.03702v1
2023-11-09,A quantum dot coupled to a suspended-beam mechanical resonator: from the unresolved- to the resolved-sideband regime,"We present experiments in which self-assembled InAs quantum dots are coupled
to a thin, suspended-beam GaAs resonator. The quantum dots are driven
resonantly and the resonance fluorescence is detected. The narrow quantum-dot
linewidths, just a factor of three larger than the transform limit, result in a
high sensitivity to the mechanical motion. We show that one quantum dot couples
to eight mechanical modes spanning a frequency range from $30$ to
$600~\mathrm{MHz}$: one quantum dot provides an extensive characterisation of
the mechanical resonator. The coupling spans the unresolved-sideband to the
resolved-sideband regimes. Finally, we present the first detection of
thermally-driven phonon sidebands (at $4.2~\mathrm{K}$) in the
resonance-fluoresence spectrum.",2311.05353v1
2023-11-09,38.7 GHz Thin Film Lithium Niobate Acoustic Filter,"In this work, a 38.7 GHz acoustic wave ladder filter exhibiting insertion
loss (IL) of 5.63 dB and 3-dB fractional bandwidth (FBW) of 17.6% is
demonstrated, pushing the frequency limits of thin-film piezoelectric acoustic
filter technology. The filter achieves operating frequency up to 5G millimeter
wave (mmWave) frequency range 2 (FR2) bands, by thinning thin-film LiNbO3
resonators to sub-50 nm thickness. The high electromechanical coupling (k2) and
quality factor (Q) of first-order antisymmetric (A1) mode resonators in 128
Y-cut lithium niobate (LiNbO3) collectively enable the first acoustic filters
at mmWave. The key design consideration of electromagnetic (EM) resonances in
interdigitated transducers (IDT) is addressed and mitigated. These results
indicate that thin-film piezoelectric resonators could be pushed to 5G FR2
bands. Further performance enhancement and frequency scaling calls for better
resonator technologies and EM-acoustic filter co-design.",2311.05712v1
2023-11-11,Resonance graphs of plane bipartite graphs as daisy cubes,"We characterize all plane bipartite graphs whose resonance graphs are daisy
cubes and therefore generalize related results on resonance graphs of benzenoid
graphs, catacondensed even ring systems, as well as 2-connected outerplane
bipartite graphs. Firstly, we prove that if $G$ is a plane elementary bipartite
graph other than $K_2$, then the resonance graph $R(G)$ is a daisy cube if and
only if the Fries number of $G$ equals the number of finite faces of $G$, which
in turn is equivalent to $G$ being homeomorphically peripheral color
alternating. Next, we extend the above characterization from plane elementary
bipartite graphs to all plane bipartite graphs and show that the resonance
graph of a plane bipartite graph $G$ is a daisy cube if and only if $G$ is
weakly elementary bipartite and every elementary component of $G$ other than
$K_2$ is homeomorphically peripheral color alternating. Along the way, we prove
that a Cartesian product graph is a daisy cube if and only if all of its
nontrivial factors are daisy cubes.",2311.06508v1
2023-11-15,Post-inflationary structure formation boosted by parametric self-resonance,"The post-inflationary Universe can pass through a long epoch of effective
matter-dominated expansion. This era may allow for both the parametric
amplification of initial fluctuations and the gravitational collapse of
inflaton perturbations. We perform first-of-their-kind high-resolution
simulations that span the resonant phase and the subsequent gravitational
collapse of the inflaton field by seguing from a full Klein-Gordon treatment of
resonance to a computationally efficient Schr\""odinger-Poisson description that
accurately captures the gravitational dynamics when most quanta are
nonrelativistic. We consider a representative example in which resonance
generates $\mathcal{O}(10^{-1})$ overdensities and gravitational collapse
follows promptly as resonance ends. We observe the formation of solitonic cores
inside inflaton halos and complex gravitational dynamics on scales of
$10^{-27}\,\mathrm{m}$, greatly extending the possible scope of nonlinear
post-inflationary gravitational dynamics.",2311.08780v2
2023-11-21,Non-resonant Anomaly Detection with Background Extrapolation,"Complete anomaly detection strategies that are both signal sensitive and
compatible with background estimation have largely focused on resonant signals.
Non-resonant new physics scenarios are relatively under-explored and may arise
from off-shell effects or final states with significant missing energy. In this
paper, we extend a class of weakly supervised anomaly detection strategies
developed for resonant physics to the non-resonant case. Machine learning
models are trained to reweight, generate, or morph the background, extrapolated
from a control region. A classifier is then trained in a signal region to
distinguish the estimated background from the data. The new methods are
demonstrated using a semi-visible jet signature as a benchmark signal model,
and are shown to automatically identify the anomalous events without specifying
the signal ahead of time.",2311.12924v2
2023-11-28,Gravitational Wave Detection and Low-Noise Sapphire Oscillators,"This thesis describes the development of an ultra-low noise sapphire
resonator oscillator that is tunable over X-band. While undertaking this task
the author has explained some interesting and very useful phenomena in regards
to the design and understanding of multi-mode resonant cavities and
oscillators. The oscillator was constructed to operate as the pump oscillator
in the superconducting parametric transducer system, attached to a 1.5-tonne
niobium resonant bar gravitational wave detector. The effects of incorporating
the pump oscillator with the parametric transducer and resonant bar system are
analyzed to enable prediction of the detector sensitivity. The detector was the
first massive precision optomechanical system ever built. With the resurgence
in interest in resonant detectors, this thesis has important work on multi-mode
acoustic systems, coupled to a highly sensitive parametric transducer relevant
for many fields of research today.",2311.16426v1
2023-12-11,Optimizing Resonator Frequency Stability in Flip-Chip Architectures: A Novel Experimental Design Approach,"In multi-qubit superconducting systems utilizing flip-chip technology,
achieving high accuracy in resonator frequencies is of paramount importance,
particularly when multiple resonators share a common Purcell filter with
restricted bandwidth. Nevertheless, variations in inter-chip spacing can
considerably influence these frequencies. To tackle this issue, we present and
experimentally validate the effectiveness of a resonator design. In our design,
we etch portions of the metal on the bottom chip that faces the resonator
structure on the top chip. This enhanced design substantially improves
frequency stability by a factor of over 3.5 compared to the non-optimized
design, as evaluated by the root mean square error of a linear fitting of the
observed frequency distribution, which is intended to be linear. This
advancement is crucial for successful scale-up and achievement of high-fidelity
quantum operations.",2312.06405v1
2023-12-14,Designing Gram-Scale Resonators for Precision Inertial Sensors,"Recent advances in glass fabrication technology have allowed for the
development of high-precision inertial sensors in devices weighing in the order
of grams. Gram-scale inertial sensors can be used in many applications with
tight space or weight requirements. A key element of these devices' performance
is the behaviour of a mechanical resonator. We present a detailed study on the
design of resonators for such sensors. First, we consider how the mechanical
parameters of a resonator couple with an inertial sensor's performance. Then,
we look at how to geometrically design resonators to achieve specific
mechanical behaviour without undergoing brittle failure. Both analytic tools
and finite element analysis are used to this end. We then derive expressions
that can be used to optimise the performance of an inertial sensor for a
specific sensitive bandwidth. A simple geometry used throughout the field is
studied as an example. However, the results are presented in a general form so
they can easily be adapted to any required geometry and use case. Ultimately,
the results presented here guide the design of gram-scale inertial sensors and
will improve the performance of devices that follow them.",2312.09298v1
2023-12-15,Lattice QCD studies of the $Δ$ baryon resonance and the $K_0^\ast(700)$ and $a_0(980)$ meson resonances: the role of exotic operators in determining the finite-volume spectrum,"Studies of the $\Delta$ baryon resonance and the $K_0^\ast(700)$ and
$a_0(980)$ meson resonances using $N_f=2+1$ lattice QCD for pion masses near
200 MeV are presented. The $s$-wave scattering lengths for both the $I=1/2$ $N
\pi$ and $I=3/2$ $N \pi$ channels and properties of the $\Delta$ resonance are
identified from the finite-volume energy levels of the lattice simulation. The
importance of a three-quark $\Delta$-operator in the $N\pi$ system and
tetraquark operators in the mesonic systems is investigated.",2312.10184v1
2023-12-19,Quantum squeezing induced quantum entanglement and EPR steering in coupled optomechanical system,"We propose a theoretical project in which quantum squeezing induces quantum
entanglement and Einstein-Podolsky-Rosen steering in a coupled
whispering-gallery-mode optomechanical system. Through pumping the
$\chi^{(2)}$-nonlinear resonator with the phase matching condition, the
generated squeezed resonator mode and the mechanical mode of the optomechanical
resonator can generate strong quantum entanglement and EPR steering, where the
squeezing of the nonlinear resonator plays the vital role. The transitions from
zero entanglement to strong entanglement and one-way steering to two-way
steering can be realized by adjusting the system parameters appropriately. The
photon-photon entanglement and steering between the two resonators can also be
obtained by deducing the amplitude of the driving laser. Our project does not
need an extraordinarily squeezed field, and it is convenient to manipulate and
provides a novel and flexible avenue for diverse applications in quantum
technology dependent on both optomechanical and photon-photon entanglement and
steering.",2312.12310v1
2023-12-19,Three-photon electron spin resonances,"We report the observation of a three-photon resonant transition of
charge-carrier spins in an organic light-emitting diode using electrically
detected magnetic resonance (EDMR) spectroscopy at room temperature. Under
strong magnetic-resonant drive (drive field $B_1$ ~ static magnetic field
$B_0$), a $B_0$-field swept EDMR line emerges when $B_0$ is approximately
threefold the one-photon resonance field. Ratios of drive-induced shifts of
this line to those of two- and one-photon shifts agree with analytical
expressions derived from the Floquet Hamiltonian and confirm the nature of
these three-photon transitions, enabling access of spin physics to a hitherto
inaccessible domain of quantum mechanics.",2312.12609v1
2023-12-22,Experimental Upper Bounds for Resonance-Enhanced Entangled Two-Photon Absorption Cross Section of Indocyanine Green,"Resonant intermediate states have been proposed to increase the efficiency of
entangled two-photon absorption (ETPA). Although resonance-enhanced ETPA
(r-ETPA) has been demonstrated in atomic systems using bright squeezed vacuum,
it has not been studied in organic molecules. We investigate for the first time
r-ETPA in an organic molecular dye, indocyanine green (ICG), when excited by
broadband entangled photons in near-IR. Similar to many reported virtual state
mediated ETPA (v-ETPA) measurements, no r-ETPA signals are measured, with an
experimental upper bound for the cross section placed at $6 \times 10^{-23}$
cm$^2$/molecule. In addition, the classical resonance-enhanced two-photon
absorption (r-TPA) cross section of ICG at 800 nm is measured for the first
time to be $20(\pm13)$ GM, suggesting that having a resonant intermediate state
does not significantly enhance two-photon processes in ICG. The
spectrotemporally resolved emission signatures of ICG excited by entangled
photons are also presented to support this conclusion.",2312.14382v1
2023-12-25,Control and readout of a transmon using a compact superconducting resonator,"We demonstrate control and readout of a superconducting artificial atom based
on a transmon qubit using a compact lumped-element resonator. The resonator
consists of a parallel-plate capacitor (PPC) with a wire geometric inductor.
The footprint of the resonators is about 200 {\mu}m by 200 {\mu}m, which is
similar to the standard transmon size and one or two orders of magnitude more
compact in the occupied area comparing to coplanar waveguide resonators. We
observe coherent Rabi oscillations and obtain time-domain properties of the
transmon. The work opens a door to miniaturize essential components of
superconducting circuits and to further scaling up quantum systems with
superconducting transmons.",2312.15753v2
2023-12-30,Symmetry breaking and mechanical filter make a pseudo-gimbal-less two-dimensional MEMS scanning mirror with multiple scanning modes,"Miniaturized two-dimensional scanning mirror based on microelectromechanical
systems (MEMS) technology has great potential in automotive industry, consumer
electronics, and biomedicine, etc. Due to its high frequency and large angle,
resonant scanning is the mainstream in all MEMS actuation mechanisms, such as
harmonic resonant electromagnetic scanner and parametric resonant electrostatic
scanner. Although electrostatic scanner has the advantages of low power
consumption and IC process compatibility, some shortcomings of parametric
resonance, including double frequency of driver electronics and additional
feedback control or frequency stabilization system, limit its further
application. The symmetry of coplanar electrostatic comb actuator is broken in
this paper, and harmonic resonant electrostatic scanner with excellent
performance is realized. Further, through adopting mechanical filter,
two-dimensional scanning can be achieved through one set of actuators, which
avoids the problem that two sets (each for one dimension) of electrostatic
actuators must be insulated each other through complicated and expensive
processes. A two-dimensional MEMS scanner based on symmetry breaking and
mechanical filter was proposed and demonstrated. Multiple scanning modes can be
achieved through selective control of a set of four identical actuators.",2401.00145v1
2024-01-08,Room-Temperature Plasmon-Assisted Resonant THz Detection in Single-layer Graphene Transistors,"Frequency-selective or even frequency-tunable Terahertz (THz) photodevices
are critical components for many technological applications that require
nanoscale manipulation, control and confinement of light. Within this context,
gate-tunable phototransistors based on plasmonic resonances are often regarded
as the most promising devices for frequency-selective detection of THz fields.
The exploitation of constructive interference of plasma waves in such detectors
not only promises frequency selectivity, but also a pronounced sensitivity
enhancement at the target frequencies. However, clear signatures of
plasmon-assisted resonances in THz detectors have been only revealed at
cryogenic temperatures so far, and remain unobserved at application-relevant
room-temperature conditions. In this work, we demonstrate the sought-after
room-temperature resonant detection of THz radiation in short-channel gated
photodetectors made from high-quality single-layer graphene. The survival of
this intriguing resonant regime at room-temperature ultimately relies on the
weak intrinsic electron-phonon scattering in graphene, which avoids the damping
of the plasma oscillations.",2401.04005v1
2024-01-12,Spin Resonance Spectroscopy with an Electron Microscope,"Coherent spin resonance methods, such as nuclear magnetic resonance and
electron spin resonance spectroscopy, have led to spectrally highly sensitive,
non-invasive quantum imaging techniques. Here, we propose a pump-probe spin
resonance spectroscopy approach, designed for electron microscopy, based on
microwave pump fields and electron probes. We investigate how quantum spin
systems couple to electron matter waves through their magnetic moments and how
the resulting phase shifts can be utilized to gain information about the states
and dynamics of these systems. Notably, state-of-the-art transmission electron
microscopy provides the means to detect phase shifts almost as small as that
due to a single electron spin. This could enable state-selective observation of
spin dynamics on the nanoscale and indirect measurement of the environment of
the examined spin systems, providing information, for example, on the atomic
structure, local chemical composition and neighboring spins.",2401.06496v1
2024-01-19,Resonances for vector-valued Jacobi operators on half-lattice,"We study resonances for Jacobi operators on the half lattice with matrix
valued coefficient and finitely supported perturbations. We describe a
forbidden domain, the geometry of resonances and their asymptotics when the
main coefficient of the perturbation (determining its length of support) goes
to zero. Moreover, we show that\\ 1) Any sequence of points on the complex
plane can be resonances for some Jacobi operators. In particular, the
multiplicity of a resonance can be any number.\\ 2) The Jost determinant
coincides with the Fredholm determinant up to the constant.\\ 3) The S-matrix
on the a.c spectrum determines the perturbation uniquely.\\ 5) The value of the
Jost matrix at any finite sequence of points on the a.c spectrum determine the
Jacobi matrix uniquely. The length of this sequence is equals to the upper
point of the support perturbation.",2401.11047v1
2024-01-30,Quantum entanglement transfer assisted via Duffing nonlinearity,"We propose a scheme to enhance quantum entanglement in an optomechanical
system by exploiting the so-called Duffing nonlinearity. Our model system
consists of two mechanically coupled mechanical resonators, both driven by an
optical field. One resonator supports Duffing nonlinearity, while the other
does not. The resonators are coupled to each other via the so-called phonon
hopping mechanism. The hopping rate is $\theta$-phase-dependent that induces
Exceptional Points (EPs) singularities in the system. Interestingly, while the
resonator with Duffing nonlinearity exhibits vanishing bipartite entanglement,
we observe an entanglement transfer phenomenon into the other mechanical
resonator. This nonlinearly induced entanglement demonstrates superior
robustness against thermal fluctuations compared to entanglement generated
without the nonlinearity. Additionally, this entanglement features the sudden
death and revival phenomenon, where the peaks happen at the multiple of
$\theta=\frac{\pi}{2}$. This work opens a new avenue for exploiting nonlinear
resources to generate robust quantum entanglement, paving the way for
advancements in quantum information processing, quantum sensing, and quantum
computing within complex systems.",2401.16809v2
2024-02-07,Triadic Resonance in Columnar Vortices,"Employing a poloidal-toroidal projection technique, a multi-scale analysis of
resonant wave triads in columnar vortices is performed to obtain the governing
equations of the triadically coupled wave amplitudes. For inviscid flows, we
establish that resonance between neutral, smooth waves is conservative, and the
temporal evolution of wave amplitudes is either bounded or explosively unstable
based on the signs of the triad's interaction coefficients. Assessing the onset
of weakly nonlinear instabilities through the pseudoenergy criterion introduced
by Cairns (1979, J. Fluid Mech., vol. 92), we use the large-axial-wavenumber
asymptotic approach by Le Dizes and Lacaze (2005, J. Fluid Mech., vol. 542) to
evaluate each triad member's pseudoenergy and argue against the possibility of
explosive conservative three-wave resonance involving only regular Kelvin
waves. Additionally, extending our investigation to specific vortices, such as
the Lamb-Oseen vortex and the Batchelor vortex, we find that triadic resonance
among their neutral modes consistently results in bounded behaviour.",2402.05287v1
2024-02-09,Fast entangling quantum gates with almost-resonant modulated driving,"Recently, the method of off-resonant modulated driving (ORMD) with a special
category of synthetic analytical pulses has improved the experimental
performance of two- and multi-qubit gates and aroused many interests for
further investigations. It particularly offers a helpful tool to the cold atom
qubit platform and works well with the Rydberg dipole-dipole interaction. In
order to explore more possibilities and wider ranges of options in constructing
fast-speed and high-fidelity quantum logic gates, we design and analyze the
entangling quantum gates via the almost-resonant modulated driving (ARMD)
method. Apart from the apparent distinctions in resonance conditions, the ARMD
gate protocols also have its different mechanisms in quantum physics compared
with ORMD gate protocols. ARMD gates usually have abrupt phase changes and at
certain points during the time evolution. In other words, whilst the modulation
forms the key concept of high-fidelity Rydberg blockade gates, the on-off
resonance condition can lead to nontrivial nuances in the styles of dynamics.
From a more fundamental point of view, the ORMD and the ARMD methods all
together belong to the unitary operation family of fast modulated driving with
respect to precisely characterized inter-qubit interactions, which usually
allows the quantum logic gate to concludes within one continuous pulse.",2402.06510v1
2024-02-08,Extinction of guided light induced by coupled spiral meta-atom resonators at arbitrary order exceptional points,"Exceptional points (EPs) in non-Hermitian systems can give rise to intriguing
effects not available in conventional Hermitian systems due to their unusual
properties. Using full-wave simulations, we investigate the scattering,
absorption, and transmission of guided light at arbitrary order exceptional
points in a non-Hermitian system consisting of coupled spiral meta-atom
resonators sitting on a dielectric waveguide. The EPs are realized by
exploiting the unidirectional coupling of the chiral dipole modes in the
subwavelength meta-atom resonators. The scattering and absorption of the
resonators induce the attenuation of the guided light in the dielectric
waveguide. We show that the EPs can give rise to a plateau in the attenuation
spectrum of the guided light with near-zero transmission, i.e., the guided
light is almost completely dissipated via the resonators in the forms of
intrinsic material loss and radiation loss. In addition, the width of this
plateau (i.e., the extinction bandwidth) increases with the order of the EP.
The phenomena can be understood by employing a coupled mode analysis, with the
analytical results quantitatively agree with the numerical results. The results
may find applications in designing novel on-chip optical absorbers and sensors.",2402.06686v1
2024-02-12,Nucleon electric and magnetic polarizabilities in Holographic QCD,"Novel experimental results for the proton generalized electric
polarizability, suggest an unexpected deviation from current theoretical
predictions at low momentum transfer squared $Q^2$. Motivated by this puzzle,
we analyze the resonance contributions to the sum of the generalized electric
and magnetic nucleon polarizabilities $\alpha_E(Q^2)$ and $\beta_M(Q^2)$,
within the Holographic QCD model by Witten, Sakai, and Sugimoto (WSS). In
particular, we account for the contributions from the first low-lying nucleon
resonances with spin 1/2 and 3/2 and both parities. After having extrapolated
the WSS model parameters to fit experimental data on baryonic observables, our
findings suggest that the resonance contributions alone do not solve the
above-mentioned puzzle. Moreover, at least for the proton case, where data are
available, our results are in qualitative agreement with resonance
contributions extracted from experimental nucleon-resonance helicity
amplitudes.",2402.07553v1
2024-02-14,The impact of load placement on grid resonances during grid restoration,"As inverter-based generation is being massively deployed in the grid, these
type of units have to take over the current roles of conventional generation,
including the capability of restoring the grid. In this context, the resonances
of the grid during the first steps of a black start can be concerning, given
that the grid is lightly loaded. Especially relevant are the low frequency
resonances, that may be excited by the harmonic components of the inverter. A
typical strategy to avoid or minimize the effect of such resonances relies on
connecting load banks. This was fairly feasible with conventional generation,
but given the limited ratings of inverters, the amount of load that can be
connected at the beginning is very limited. In this paper we consider the
energization of a transmission line, and investigate the optimal location of a
load along a line in order to maximize the damping in the system. By analysing
the spectral properties as a function of the load location, we formally prove
that placing the load in the middle of the transmission line maximizes the
damping ratio of the first resonance of the system.",2402.09294v1
2024-02-15,Investigating finite-size effects in random matrices by counting resonances,"Resonance counting is an intuitive and widely used tool in Random Matrix
Theory and Anderson Localization. Its undoubted advantage is its simplicity: in
principle, it is easily applicable to any random matrix ensemble. On the
downside, the notion of resonance is ill-defined, and the `number of
resonances' does not have a direct mapping to any commonly used physical
observable like the participation entropy, the fractal dimensions, or the gap
ratios (r-parameter), restricting the method's predictive power to the
thermodynamic limit only where it can be used for locating the Anderson
localization transition. In this work, we reevaluate the notion of resonances
and relate it to measurable quantities, building a foundation for the future
application of the method to finite-size systems. To access the HTML version of
the paper & discuss it with the authors, visit https://enabla.com/pub/558.",2402.10271v2
2024-02-16,Controlled light distribution with coupled microresonator chains via Kerr symmetry breaking,"Within optical microresonators, the Kerr interaction of photons can lead to
symmetry breaking of optical modes. In a ring resonator, this leads to the
interesting effect that light preferably circulates in one direction or in one
polarization state. Applications of this effect range from chip-integrated
optical diodes to nonlinear polarization controllers and optical gyroscopes. In
this work, we study Kerr-nonlinearity-induced symmetry breaking of light states
in coupled resonator optical waveguides (CROWs). We discover a new type of
controllable symmetry breaking that leads to emerging patterns of dark and
bright resonators within the chains. Beyond stationary symmetry broken states,
we observe periodic oscillations, switching and chaotic fluctuations of
circulating powers in the resonators. Our findings are of interest for
controlled multiplexing of light in photonic integrated circuits, neuromorphic
computing, topological photonics and soliton frequency combs in coupled
resonators.",2402.10673v1
2024-03-05,Extreme resonant eccentricity excitation of stars around merging black-hole binary,"We study the dynamics of a star orbiting a merging black-hole binary (BHB) in
a coplanar triple configuration. During the BHB's orbital decay, the system can
be driven across the apsidal precession resonance, where the apsidal precession
rate of the stellar orbit matches that of the inner BHB. As a result, the
system gets captured into a state of resonance advection until the merger of
the BHB, leading to an extreme eccentricity growth of the stellar orbit. This
resonance advection occurs when the inner binary has a non-zero eccentricity
and unequal masses. The resonant driving of the stellar eccentricity can
significantly alter the hardening rate of the inner BHB, and produce
observational signatures to uncover the presence of nearby merging or merged
BHBs.",2403.03250v1
2024-03-08,Emergent resonances in a thin film tailored by optically-induced small permittivity asymmetries,"Resonances are usually associated with finite systems - the vibrations of
clamped strings in a guitar or the optical modes in a cavity defined by
mirrors. In optics, resonances may be induced in infinite continuous media via
periodic modulations of their optical properties. Here we demonstrate that
periodic modulations of the permittivity of a featureless thin film can also
act as a symmetry breaking mechanism, allowing the excitation of photonic
$\textit{quasi}$-bound states in the continuum ($\textit{q}$BICs). By
interfering two ultrashort laser pulses in the unbounded film, transient
resonances can be tailored through different parameters of the pump beams. We
show that the system offers resonances tunable in wavelength and
quality-factor, and spectrally selective enhancement of third harmonic
generation. Due to a fast decay of the permittivity asymmetry, we observe
ultrafast dynamics, enabling time-selective near-field enhancement with
picosecond precision. Optically-induced permittivity asymmetries may be
exploited in on-demand weak to ultrastrong light-matter interaction regimes and
light manipulation at dynamically chosen wavelengths in lithography-free
metasurfaces.",2403.05730v1
2024-03-11,Modified Coupled-mode Theory for the Absorption in Plasmonic Lattices,"Surface lattice resonance supported on plasmonic nanoparticle arrays enhances
light-matter interactions for applications such as photoluminescence
enhancement. The photoluminescence process is enhanced through confining light
beyond the diffraction limit and inducing stronger light-matter interaction. In
this work, the absorption mechanisms of plasmonic nanoparticle arrays embedded
with photoluminescent absorbers are analyzed. A modified coupled-mode theory
that describes the optical behavior of the surface lattice resonance was
developed and verified by numerical simulations. Based on the analytical model,
different components of the absorption contributed by the nanoparticles and the
absorbers as well as the resonant properties of each of the components are
identified. The origin of difference in resonant behavior with different
materials is also discovered by exploring the nearfield characteristics of
surface lattice resonance composed with a variety of materials.",2403.06540v1
2024-03-25,Searches for Higgs boson production through decays of heavy resonances,"The discovery of the Higgs boson has led to new possible signatures for heavy
resonance searches at the LHC. Since then, search channels including at least
one Higgs boson plus another particle have formed an important part of the
program of new physics searches. In this report, the status of these searches
by the CMS Collaboration is reviewed. Searches are discussed for resonances
decaying to two Higgs bosons, a Higgs and a vector boson, or a Higgs boson and
another new resonance, with proton-proton collision data collected at
$\sqrt{s}$ = 13 TeV in the years 2016-2018. A combination of the results of
these searches is presented together with constraints on different
beyond-the-standard model scenarios, including scenarios with extended Higgs
sectors, heavy vector bosons and extra dimensions. Studies are shown for the
first time by CMS on the validity of the narrow-width approximation in searches
for the resonant production of a pair of Higgs bosons. The potential for a
discovery at the High Luminosity LHC is also discussed.",2403.16926v1
2024-04-04,A new 700 GeV scalar in the LHC data?,"As an alternative to the metastability of the electroweak vacuum, resulting
from perturbative calculations, one can consider a non-perturbative effective
potential which, as at the beginning of the Standard Model, is restricted to
the pure $\Phi^4$ sector yet consistent with the known analytical and numerical
studies. In this approach, where the electroweak vacuum is now the
lowest-energy state, besides the resonance of mass $m_h=$ 125 GeV defined by
the quadratic shape of the potential at its minimum, the Higgs field should
exhibit a second resonance with mass $(M_H)^{\rm Theor}=690\,(30)$ GeV
associated with the zero-point energy determining the potential depth. In spite
of its large mass, this resonance would couple to longitudinal $W$s with the
same typical strength as the low-mass state at 125 GeV and represent a
relatively narrow resonance, mainly produced at LHC by gluon-gluon fusion.
  In this Letter, we review LHC data suggesting a new resonance of mass
$(M_H)^{\rm EXP} \sim 682\,(10)$ GeV, with a statistical significance that is
far from negligible.",2404.03711v1
1997-09-01,Parametric Resonance in an Expanding Universe,"Parametric resonance has been discussed as a mechanism for copious particle
production following inflation. Here we present a simple and intuitive
calculational method for estimating the efficiency of parametric amplification
as a function of parameters. This is important for determining whether resonant
amplification plays an important role in the reheating process. We find that
significant amplification occurs only for a limited range of couplings and
interactions.",9709006v1
1998-08-22,Resonance Type Instabilities in the Gaseous Disks of the Flat Galaxies I. The Acoustical Resonance Type Instability and the Absence of Vortex Sheet Stabilization on Shallow Water,"Linear analysis of vortex sheet stability in the rotating gaseous disk or
shallow water layer shows that presence of a central reflecting surface changes
system stability significantly. An effect of absence of vortex sheet
stabilization has been found as compressibility exceeds Landau criterion. The
properties of multimode short-scale instability of acoustical resonance type
are investigated and probability of its influence upon experiments on the
rotating shallow water is discussed.",9808247v1
1998-11-03,Resonance Paramagnetic Relaxation and Alignment of Ultrasmall Grains,"This paper gives a short summary of a mechanism of the enhanced paramagnetic
relaxation that acts on rapidly rotating interstellar grains. We show that the
Barnett magnetization that arises from grain rotation ensures that paramagnetic
absorption happens at its maximum efficiency, i.e. the conditions for
paramagnetic resonance are automatically fulfilled. The differences between the
predictions of classical Davis-Greenstein relaxation and the process which we
refer to as ``resonance relaxation'' are most pronounced for grains rotating
faster than 10 GHz. Microwave polarization is likely to be an impediment for
cosmic microwave background studies, but can provide a good tool for studying
galactic magnetic field.",9811041v1
1999-01-12,Resonances and instabilities in symmetric multistep methods,"The symmetric multistep methods developed by Quinlan and Tremaine (1990) are
shown to suffer from resonances and instabilities at special stepsizes when
used to integrate nonlinear equations. This property of symmetric multistep
methods was missed in previous studies that considered only the linear
stability of the methods. The resonances and instabilities are worse for
high-order methods than for low-order methods, and the number of bad stepsizes
increases with the number frequencies present in the solution. Symmetric
methods are still recommended for some problems, including long-term
integrations of planetary orbits, but the high-order methods must be used with
caution.",9901136v1
1999-10-14,Coherent Mechanisms of Pulsar Radio Emission,"Relativistic plasma masers operating on the anomalous cyclotron-Cherenkov
resonance and the Cherenkov-drift resonance are capable of explaining the main
observational characteristics of pulsar radio emission.
  Both electromagnetic instabilities are due to the interaction of the fast
particles from the primary beam and from the tail of the secondary pairs
distribution with the normal modes of a strongly magnetized one-dimensional
electron-positron plasma. In a typical pulsar both resonances occur in the
outer parts of magnetosphere .",9910262v1
1999-10-20,Photoionization of Fe XV,"Relativistic and resonance effects in the photoionization of Mg-like Fe~XV
are investigated using the Breit-Pauli R-matrix Method (BPRM) at near-threshold
and intermediate energies, complemented by the Relativistic Random Phase
Approximation (RRPA) and multi-channel quantum defect theory in the energy
region up to the L-shell ionization thresholds. The cross sections exhibit
extensive resonance structures that considerably enhance the effective
photoionization of Fe~XV. These results should be of general interest in
photoionization modeling of X-ray sources observed by space observatories.",9910374v1
2002-08-03,Enhancement of Resonant Thermonuclear Reaction Rates in Extremely Dense Stellar Plasmas,"The enhancement factor of the resonant thermonuclear reaction rates is
calculated for the extremely dense stellar plasmas in the liquid phase. In
order to calculate the enhancement factor we use the screening potential which
is deduced from the numerical experiment of the classical one-component plasma.
It is found that the enhancement is tremendous for white dwarf densities if the
^{12}C + ^{12}C fusion cross sections show resonant behavior in the
astrophysical energy range. We summarize our numerical results by accurate
analytic fitting formulae.",0208071v2
2002-09-13,The Geometry of Resonant Signatures in Debris Disks with Planets,"Using simple geometrical arguments, we paint an overview of the variety of
resonant structures a single planet with moderate eccentricity (e < ~0.6) can
create in a dynamically cold, optically thin dust disk. This overview may serve
as a key for interpreting images of perturbed debris disks and inferring the
dynamical properties of the planets responsible for the perturbations. We
compare the resonant geometries found in the solar system dust cloud with
observations of dust clouds around Vega and other stars and we discuss a new
model for the asymmetries in the Epsilon Eridani cloud.",0209261v2
2003-07-11,Origin of Chaos in the Prometheus-Pandora System,"We demonstrate that the chaotic orbits of Prometheus and Pandora are due to
interactions associated with the 121:118 mean motion resonance. Differential
precession splits this resonance into a quartet of components equally spaced in
frequency. Libration widths of the individual components exceed the splitting
resulting in resonance overlap which causes the chaos. A single degree of
freedom model captures the essential features of the chaotic dynamics. Mean
motions of Prometheus and Pandora wander chaotically in zones of width 1.8
deg/yr and 3.1 deg/yr, respectively.",0307259v1
2005-01-31,Resonant Auger Destruction and Iron K-Alpha Spectra in Compact X-ray Sources,"We examine the effects of resonant Auger destruction in modifying the
intensities and flux distributions of K-alpha spectra from iron L-shell ions.
Applications include X-ray irradiated stellar winds in X-ray binaries and
accretion disk atmospheres. Using detailed atomic models, we find that resonant
Auger destruction is selective, in that only a subset of the emitted K-alpha
lines is highly attenuated. We also show that that the local excitation
conditions can have a dramatic effect on the K-alpha emissivity spectrum.",0502002v1
2005-05-11,A Resonance Model of Quasi-Periodic Oscillations of Low-Mass X-Ray Binaries,"We try to understand the quasi-periodic oscillations (QPOs) in low-mass
neutron-star and black-hole X-ray binaries by a resonance model in warped disks
with precession. Our main concern is high-frequency QPOs, hectohertz QPOs, and
horizontal-branch QPOs in the z sources and the atoll sources, and the
correponding QPOs in black-hole X-ray binaries. Our resonance model can
qualitatively, but systematically, explain these QPOs by regarding hectohertz
QPOs as a precession of warp.",0505215v1
2005-05-27,Second order perturbation theory for spin-orbit resonances,"We implement Lie transform perturbation theory to second order for the planar
spin-orbit problem. The perturbation parameter is the asphericity of the body,
with the orbital eccentricity entering as an additional parameter. We study
first and second order resonances for different values of these parameters. For
nearly spherical bodies like Mercury and the Moon first order perturbation
theory is adequate, whereas for highly aspherical bodies like Hyperion the spin
is mostly chaotic and perturbation theory is of limited use. However, in
between, we identify a parameter range where second order perturbation theory
is useful and where as yet unidentified objects may be in second order
resonances.",0505559v1
2006-10-03,Mean-motion resonances in satellite-disc interactions,"Mean-motion resonances between a Keplerian disc and an orbiting companion are
analysed within a Hamiltonian formulation using complex canonical Poincare
variables, which are ideally suited to the description of eccentricity and
inclination dynamics. Irreversibility is introduced by allowing for dissipation
within the disc. A method is given for determining the rates of change of
eccentricity and inclination variables of the disc and companion associated
with resonances of various orders, including both reversible and irreversible
effects, which extend and generalize previous results. Preliminary applications
to protoplanetary systems and close binary stars are discussed.",0610082v3
1995-07-07,Universal diffusion near the golden chaos border,"We study local diffusion rate $D$ in Chirikov standard map near the critical
golden curve. Numerical simulations confirm the predicted exponent $\alpha=5$
for the power law decay of $D$ as approaching the golden curve via principal
resonances with period $q_n$ ($D \sim 1/q^{\alpha}_n$). The universal
self-similar structure of diffusion between principal resonances is
demonstrated and it is shown that resonances of other type play also an
important role.",9507001v1
1996-06-06,Resonant interactions in Bénard-Marangoni convection in cylindrical containers,"Convection in a cylindrical container of small aspect ratio is studied. It is
known that when, in addition to buoyancy forces, thermocapillarity effects are
taken into account, resonant interactions of two modes may appear. In the case
of 1:2 resonance amplitude equations are derived, showing the existence of a
stable heteroclinic orbit and rotating waves, until now not observed
experimentally.",9605016v1
1998-03-27,Resonant enhanced diffusion in time dependent flow,"Explicit examples of scalar enhanced diffusion due to resonances between
different transport mechanisms are presented. Their signature is provided by
the sharp and narrow peaks observed in the effective diffusivity coefficients
and, in the absence of molecular diffusion, by anomalous transport. For the
time-dependent flow considered here, resonances arise between their
oscillations in time and either molecular diffusion or a mean flow. The
effective diffusivities are calculated using multiscale techniques.",9804003v1
1999-02-01,Quantum resonances and decay of a chaotic fractal repeller observed using microwaves,"The quantum resonances of classically chaotic n-disk geometries were studied
experimentally utilizing thin 2-D microwave geometries. The experiments yield
the frequencies and widths of low-lying resonances, which are compared with
semiclassical calculations. The longtime or small energy behavior of the
wave-vector auto-correlation gives information about the quantum decay rate,
which is in good agreement with that obtained from classical scattering theory.
The intermediate energy behavior shows non-universal oscillations determined by
periodic orbits.",9902002v2
1999-07-26,Quantum Resonances of Kicked Rotor and SU(q) group,"The quantum kicked rotor (QKR) map is embedded into a continuous unitary
transformation generated by a time-independent quasi-Hamiltonian. In some
vicinity of a quantum resonance of order $q$, we relate the problem to the {\it
regular} motion along a circle in a $(q^2-1)$-component inhomogeneous
""magnetic"" field of a quantum particle with $q$ intrinsic degrees of freedom
described by the $SU(q)$ group. This motion is in parallel with the classical
phase oscillations near a non-linear resonance.",9907033v1
1993-04-07,Resonant Tunneling Between Quantum Hall Edge States,"Resonant tunneling between fractional quantum Hall edge states is studied in
the Luttinger liquid picture. For the Laughlin parent states, the resonance
line shape is a universal function whose width scales to zero at zero
temperature. Extensive quantum Monte Carlo simulations are presented for $\nu =
1/3$ which confirm this picture and provide a parameter-free prediction for the
line shape.",9304010v1
1993-09-02,Instabilities of the Abrikosov-Suhl resonance,"We consider the possibility that instabilities of the Abrikosov-Suhl
resonance lead to new fixed point behavior of the Kondo effect in a lattice
environment. In one scenario, a pairing component to the resonant scattering
develops in the Kondo lattice, leading to an odd frequency superconductor. We
discuss experiments that can discriminate between this picture and d-wave
pairing, and its relationship to the non Fermi liquid fixed point of the
overscreened Kondo model.",9309004v1
1994-06-27,Resonance Magnetoresistance in Coupled Quantum Wells,"The in-plane magnetic field suppresses the quantum coupling between electrons
in a double quantum well structure. The microscopical theory of this effect is
developed and confirmed experimentally. We have shown that the decrease of the
""resistance resonance"" peak is sensitive to the mutual orientation of the
current and the in-plane magnetic field. The characteristic field required for
the suppression of the resonance depends on the elastic small angle and
electron--electron scattering rates. The study of the characteristic field
allows to verify the temperature and Fermi energy dependence of the
electron--electron scattering rate, providing a new experimental tool for its
measurement.",9406102v1
1994-08-05,Plasma Resonance in Layered Normal Metals and Superconductors,"A microscopic theory of the plasma resonance in layered metals is presented.
It is shown that electron-impurity scattering can suppress the plasma resonance
in the normal state and sharpen it in the superconducting state. Analytic
properties of the conductivity for the electronic transport perpendicular to
the layers are investigated. The dissipative part of the electromagnetic
response in c-direction has been found to depend on frequency in a highly
non-trivial manner. This sort of behavior cannot be incorporated in the widely
used phenomenological Gorter-Kazimir model.",9408027v2
1994-11-01,Cyclotron resonance lineshape in a Wigner crystal,"The cyclotron resonance absorption spectrum in a Wigner crystal is
calculated. Effects of spin-splitting are modelled by substitutional disorder,
and calculated in the coherent potential approximation. Due to the increasing
strength of the dipole-dipole interaction, the results show a crossover from a
double-peak spectrum at small filling factors to a single-peak spectrum at
filling factors $\agt 1/6$. Radiation damping and magnetophonon scattering can
also influence the cyclotron resonance. The results are in very good agreement
with experiments.",9411003v2
1995-02-08,Independent-Electron Model for the Phase of the Transmission Amplitude in Quantum Dots,"Motivated by a recent experiment by Yacoby et al.\ [preprint, 1994], we
calculate magnitude and phase $\alpha$ of the transmission amplitude through a
quantum dot. We work in the Coulomb blockade regime, assume the electrons not
to interact, and consider tunneling through isolated resonances. Assuming a
non--resonant background, we find that $\alpha$ increases by $2 \pi$ over each
resonance, with a sharp rise by $\pi$ over an energy interval much smaller than
the thermal width. This is consistent with the experimental data. Our
assumptions can be tested by further experiments.",9502033v1
1995-11-15,Resonant Two-Magnon Raman Scattering in Cuprate Antiferromagnetic Insulators,"We present results of low-temperature two-magnon resonance Raman excitation
profile measurements for single layer Sr_2CuO_2Cl_2 and bilayer YBa_2Cu_3O_{6 +
\delta} antiferromagnets over the excitation region from 1.65 to 3.05 eV. These
data reveal composite structure of the two-magnon line shape and strong
nonmonotic dependence of the scattering intensity on excitation energy. We
analyze these data using the triple resonance theory of Chubukov and Frenkel
(Phys. Rev. Lett., 74, 3057 (1995)) and deduce information about magnetic
interaction and band parameters in these materials.",9511080v1
1996-02-08,Nonlinear resonant tunneling in systems coupled to quantum reservoirs,"An adiabatic approximation in terms of instantaneous resonances is developed
to study the steady-state and time-dependent transport of interacting electrons
in biased resonant tunneling heterostructures. The resulting model consists of
quantum reservoirs coupled to regions where the system is described by
nonlinear ordinary differential equations and has a general conceptual
interest.",9602047v3
1996-11-14,"Chaos, interactions, and nonequilibrium effects in the tunneling resonance spectra of small metallic particles","We explain the observation of clusters in the tunneling resonance spectra of
small metallic particles of few nanometer size. Each cluster of resonances is
identified with one excited single--electron state of the metal particle,
shifted as a result of the different nonequilibrium occupancy configurations of
the other single--electron states. Assuming the underlying classical dynamics
of the electrons to be chaotic, we determine the typical shift to be $\Delta/g$
where $g$ is the dimensionless conductance of the grain.",9611115v1
1997-05-15,Pseudogap effects induced by resonant pair scattering,"We demonstrate how resonant pair scattering of correlated electrons above T_c
can give rise to pseudogap behavior. This resonance in the scattering T-matrix
appears for superconducting interactions of intermediate strength, within the
framework of a simple fermionic model. It is associated with a splitting of the
single peak in the spectral function into a pair of peaks separated by an
energy gap. Our physical picture is contrasted with that derived from other
T-matrix schemes, with superconducting fluctuation effects, and with preformed
pair (boson-fermion) models. Implications for photoemission and tunneling
experiments in the cuprates are discussed.",9705144v1
1997-09-24,Resonance tunneling of polaritons in 1-D chain with a single defect,"We consider propagation of coupled waves (polaritons) formed by a scalar
electromagnetic wave and excitations of a finite one dimensional chain of
dipoles. It is shown that a microscopic defect (an impurity dipole) embedded in
the chain causes resonance tunneling of the electromagnetic wave with the
frequency within the forbidden band between two polariton branches. We
demonstrate that resonance tunneling occurs due to local polariton states
caused by the defect.",9709267v2
1997-10-22,X-Ray Resonant Scattering as a Direct Probe of Orbital Ordering in Transition-Metal Oxides,"X-ray resonant scattering at the K-edge of transition metal oxides is shown
to measure the orbital order parameter, supposed to accompany magnetic ordering
in some cases. Virtual transitions to the 3d-orbitals are quadrupolar in
general. In cases with no inversion symmetry, such as V$_2$O$_3$, treated in
detail here, a dipole component enhances the resonance. Hence, we argue that
the detailed structure of orbital order in V$_2$O$_3$ is experimentally
accessible.",9710232v1
1997-10-29,Magnetic Resonance in the Spin-Peierls compound $α'-NaV_2O_5$,"We present results from magnetic resonance measurements for 75-350 GHz in
$\alpha$'-NaV$_{2}$O$_{5}$. The temperature dependence of the integrated
intensity indicates that we observe transitions in the excited state. A
quantitative description gives resonances in the triplet state at high symmetry
points of the excitation spectrum of this Spin-Peierls compound. This energy
has the same temperature dependence as the Spin-Peierls gap. Similarities and
differences with the other inorganic compound CuGeO$_{3}$ are discussed.",9710318v1
1997-11-04,Resonant Andreev Tunneling in Strongly Interacting Quantum Dots,"We study resonant Andreev tunneling through a strongly interacting quantum
dot connected to a normal and to a superconducting lead. We obtain a formula
for the Andreev current and apply it to discuss the linear and non-linear
transport in the nonperturbative regime, where the effects of the Kondo
resonance on the two particle tunneling arise. In particular we notice an
enhancement of the Kondo anomaly in the $I-V$ characteristics due to the
superconducting electrode.",9711020v1
1998-01-07,Resonant Raman scattering by collective modes of the one-dimensional electron gas,"We show that the low-energy peak in the polarized resonant Raman spectra of
quantum wires, which is commonly associated with ``single particle
excitations'', can be interpreted as signature of intra-band collective spin
excitations. A broad maximum in the resonant depolarized spectra is predicted
to exist above the frequency of the spin density excitation, due to
simultaneous but independent propagation of spin- and charge-density modes.",9801058v1
1998-03-26,Effect of deconfinement on resonant transport in quantum wires,"The effect of deconfinement due to finite band offsets on transport through
quantum wires with two constrictions is investigated. It is shown that the
increase in resonance linewidth becomes increasingly important as the size is
reduced and ultimately places an upper limit on the energy (temperature) scale
for which resonances may be observed.",9803322v1
1998-05-25,Inter-Condensate Tunneling in Bose-Einstein Condensates with Feshbach Resonances,"Recently, effects of Feshbach resonances in atom-atom interactions were
observed by varying the external magnetic field of an atomic Bose-Einstein
condensate (BEC). We point out that the quasi-bound molecules created in the
intermediate state of the resonance can form a second, molecular condensate.
The many-body state of the system is then a hybrid atomic/molecular condensate
with inter-condensate tunneling of atom pairs. A sudden variation of the
magnetic field results in oscillations of the number of atoms and molecules in
their respective condensates, providing a signature of this novel type of
quantum tunneling.",9805323v1
1998-06-26,The Effects of Resonant Tunneling on Magnetoresistance through a Q uantum Dot,"The effect of resonant tunneling on magnetoresistance (MR) is studied
theoretically in a double junction system. We have found that the ratio of the
MR of the resonant peak current is reduced more than that of the single
junction, whereas that of the valley current is enhanced depending on the
change of the discrete energy-level under the change of magnetic field. We also
found that the peak current-valley current (PV) ratio decreases when the
junction conductance increases.",9806314v1
1998-07-02,Josephson Plasma Resonance as a Structural Probe of Vortex Liquid,"Recent developments of the Josephson plasma resonance and transport c-axis
measurements in layered high T$_{c}$ superconductors allow to probe Josephson
coupling in a wide range of the vortex phase diagram. We derive a relation
between the field dependent Josephson coupling energy and the density
correlation function of the vortex liquid. This relation provides a unique
opportunity to extract the density correlation function of pancake vortices
from the dependence of the plasma resonance on the $ab$-component of the
magnetic field at a fixed $c$-axis component.",9807043v1
1998-07-21,Correlations of conductance peaks and transmission phases in deformed quantum dots,"We investigate the Coulomb blockade resonances and the phase of the
transmission amplitude of a deformed ballistic quantum dot weakly coupled to
leads. We show that preferred single--particle levels exist which stay close to
the Fermi energy for a wide range of values of the gate voltage. These states
give rise to sequences of Coulomb blockade resonances with correlated peak
heights and transmission phases. The correlation of the peak heights becomes
stronger with increasing temperature. The phase of the transmission amplitude
shows lapses by $\pi$ between the resonances. Implications for recent
experiments on ballistic quantum dots are discussed.",9807286v1
1998-07-23,Quantum Zeno effect and parametric resonance in mesoscopic physics,"As a realization of the quantum Zeno effect, we consider electron tunneling
between two quantum dots with one of the dots coupled to a quantum point
contact detector. The coupling leads to decoherence and to the suppression of
tunneling. When the detector is driven with an ac voltage, a parametric
resonance occurs which strongly counteracts decoherence. We propose a novel
experiment with which it is possible to observe both the quantum Zeno effect
and the parametric resonance in electric transport.",9807317v1
1998-07-27,"Kondo-resonance, Coulomb blockade, and Andreev transport through a quantum dot","We study resonant tunneling through an interacting quantum dot coupled to
normal metallic and superconducting leads. We show that large Coulomb
interaction gives rise to novel effects in Andreev transport. Adopting an exact
relation for the Green's function, we find that at zero temperature, the linear
response conductance is enhanced due to Kondo-Andreev resonance in the Kondo
limit, while it is suppressed in the empty site limit. In the Coulomb blockaded
region, on the other hand, the conductance is reduced more than the
corresponding conductance with normal leads because large charging energy
suppresses Andreev reflection.",9807351v1
1998-09-21,Nontrivial stochastic resonance temperature for the kinetic Ising model,"The kinetic Ising model in a weak oscillating magnetic field is studied in
the context of stochastic resonance. The signal-to-noise ratio calculated with
simulations is found to peak at a nontrivial resonance temperature above the
equilibrium critical temperature T_c. We argue that its appearance is closely
related to the vanishing of the kinetic coefficient at T_c. Comparisons with
various theoretical results in one and higher dimensions are made.",9809269v1
1998-09-30,Far infrared giant dipole resonances in neutral quantum dots,"A resonance behaviour of the far infrared absorption probability at a
frequency \sim N^{1/4} is predicted for clusters of N electron-hole pairs (2\le
N\le 110) confined in disk-shaped quantum dots. For radially symmetric dots,
the absorption is dominated by a Giant Dipole Resonance, which accounts for
more than 98 % of the energy-weighted photoabsorption sum rule.",9809399v2
1998-10-05,Anomalous Resonance of the Symmetric Single-Impurity Anderson Model in the Presence of Pairing Fluctuations,"We consider the symmetric single-impurity Anderson model in the presence of
pairing fluctuations. In the isotropic limit, the degrees of freedom of the
local impurity are separated into hybridizing and non-hybridizing modes. The
self-energy for the hybridizing modes can be obtained exactly, leading to two
subbands centered at $\pm U/2$. For the non-hybridizing modes, the second order
perturbation yields a singular resonance of the marginal Fermi liquid form. By
multiplicative renomalization, the self-energy is derived exactly, showing the
resonance is pinned at the Fermi level, while its strength is weakened by
renormalization.",9810033v1
1999-02-18,Coherent Polariton Radiation and Light Localization,"A system of resonance atoms is placed in a medium with developed polariton
effect. In the spectrum of polariton states there can exist a band gap. If an
atom with a resonance frequency inside the polariton gap is incorporated into
the medium, the atomic spontaneous emission can be strongly suppressed. This is
what is called the localization of light. Nevertheless, an ensemble of
resonance atoms inside the polariton gap can radiate if their coherent
interaction is sufficiently strong. Conditions when coherent polariton
radiation can appear and the properties of this coherent polariton emission are
studied.",9902257v1
1999-03-15,Resonant Raman scattering of quantum wire in strong magnetic field,"The resonant Raman scattering of a quantum wire in a strong magnetic field is
studied, focused on the effect of long range Coulomb interaction and the
spin-charge separation. The energy-momentum dispersions of charge and spin
excitation obtained from Raman cross-section show the characteristc cross-over
behaviour induced by inter-edge Coulomb interaction. The ""SPE"" peak near
resonance in polarized spectra becomes broad due to the momentum dependence of
charge velocity. The broad peak in the depolarized spectra is shown to
originate from the disparity between charge and spin excitation velocity.",9903225v1
1999-03-15,How long does it take for the Kondo effect to develop?,"The time-development of the Kondo effect is theoretically investigated by
studying a quantum dot suddenly shifted into the Kondo regime by a change of
voltage on a nearby gate. Using time-dependent versions of both the Anderson
and Kondo Hamiltonians, it is shown that after a time $t$ following the voltage
shift, the form of the Kondo resonance matches the {\it time-independent}
resonance at an effective temperature $T_{eff} = T/\tanh(\pi T t/2)$. Relevance
of the buildup of the Kondo resonance to the transport current through a
quantum dot is demonstrated.",9903240v1
1999-06-11,Synchronization under periodic modulation of potential wells in a two-state stochastic system,"We analyse the effect of synchronization between noise and periodic signal in
a two-state spatially extended system analytically. Resonance features are
demonstrated. To have the maximum cooperation between signal and noise, it is
shown that noise strength at resonance should increase linearly with the
frequency of the signal. The time scale of the process at resonance is also
shown to increase linearly with the period of the signal.",9906161v1
1999-07-22,Mobility and stochastic resonance in spatially inhomogeneous system,"The mobility of an overdamped particle, in a periodic potential tilted by a
constant external field and moving in a medium with periodic friction
coefficient is examined. When the potential and the friction coefficient have
the same periodicity but have a phase difference, the mobility shows many
interesting features as a function of the applied force, the temperature, etc.
The mobility shows stochastic resonance even for constant applied force, an
issue of much recent interest. The mobility also exhibits a resonance like
phenomenon as a function of the field strength and noise induced slowing down
of the particle in an appropriate parameter regime.",9907353v1
1999-07-30,A Modified Approach to Single-Spin Detection Using Magnetic Resonance Force Microscopy,"The magnetic moment of a single spin interacting with a cantilever in
magnetic resonance force microscopy (MRFM) experiences quantum jumps in
orientation rather than smooth oscillations. These jumps cannot be detected by
a conventional MRFM based on observation of driven resonant oscillations of a
cantilever. In this paper, we propose a method which will allow detection of
the magnetic signal from a single spin using a modification of a conventional
MRFM. We estimate the opportunity to detect the magnetic signal from a single
proton.",9907495v1
1999-08-29,Local spin resonance and spin-Peierls-like phase transition in a geometrically frustrated antiferromagnet,"Using inelastic magnetic neutron scattering we have discovered a localized
spin resonance at 4.5 meV in the ordered phase of the geometrically frustrated
cubic antiferromagnet $\rm ZnCr_2O_4$. The resonance develops abruptly from
quantum critical fluctuations upon cooling through a first order transition to
a co-planar antiferromagnet at $T_c=12.5(5)$ K. We argue that this transition
is a three dimensional analogue of the spin-Peierls transition.",9908433v2
1999-09-01,Time Delay Correlations and Resonances in 1D Disordered Systems,"The frequency dependent time delay correlation function $K(\Omega)$ is
studied analytically for a particle reflected from a finite one-dimensional
disordered system. In the long sample limit $K(\Omega)$ can be used to extract
the resonance width distribution $\rho(\Gamma)$. Both quantities are found to
decay algebraically as $\Gamma^{-\nu}$, and $\Omega^{-\nu}$, $\nu\simeq 1.25$
in a large range of arguments. Numerical calculations for the resonance width
distribution in 1D non-Hermitian tight-binding model agree reasonably with the
analytical formulas.",9909010v2
1999-09-28,Enhancement of Stochastic Resonance in distributed systems due to a selective coupling,"Recent massive numerical simulations have shown that the response of a
""stochastic resonator"" is enhanced as a consequence of spatial coupling.
Similar results have been analytically obtained in a reaction-diffusion model,
using ""nonequilibrium potential"" techniques. We now consider a field-dependent
diffusivity and show that the ""selectivity"" of the coupling is more efficient
for achieving stochastic-resonance enhancement than its overall value in the
constant-diffusivity case.",9909397v1
1999-09-29,Results from bosonisation for resonant tunneling through a quantum dot in an Aharanov-Bohm ring,"We study coherent charge tunneling through a one-dimensional interacting ring
with a one-dimensional quantum dot embedded in one of its arms through
bosonisation. The symmetries of the effective action explain many of the
features such as phase change between resonances, in-phase successive
resonances and phase-locking, which have been observed in experiments of
coherent transport in mesoscopic rings, with a quantum dot. We also predict
changes in the behaviour of the tunneling conductance in the presence of an
Aharanov-Bohm flux through the ring. We argue that these results hold true in
general for any dot.",9909417v1
1999-10-21,Nanomechanical resonators operating as charge detectors in the nonlinear regime,"We present measurements on nanomechanical resonators machined from
Silicon-on-Insulator substrates. The resonators are designed as freely
suspended Au/Si beams of lengths on the order of 1 - 4 um and a thickness of
200 nm. The beams are driven into nonlinear response by an applied modulation
at radio frequencies and a magnetic field in plane. The strong hysteresis of
the magnetomotive response allows sensitive charge detection by varying the
electrostatic potential of a gate electrode.",9910334v1
1999-11-09,Cooper Pairing in Ultracold K-40 Using Feshbach Resonances,"We point out that the fermionic isotope K-40 is a likely candidate for the
formation of Cooper pairs in an ultracold atomic gas. Specifically, in an
optical trap that simultaneously traps the spin states |9/2,-9/2> and
|9/2,-7/2>, there exists a broad magnetic field Feshbach resonance at B = 196
gauss that can provide the required strong attractive interaction between
atoms. An additional resonance, at B = 191 gauss, could generate p-wave pairing
between identical |9/2,-7/2> atoms. A Cooper-paired degenerate Fermi gas could
thus be constructed with existing ultracold atom technology.",9911132v1
1999-11-26,Acoustic Cyclotron Resonance and Giant High Frequency Magnetoacoustic Oscillations in Metals with Locally Flattened Fermi Surface,"We consider the effect of local flattening on the Fermi surface (FS) of a
metal upon geometric oscillations of the velocity and attenuation of ultrasonic
waves in the neighborhood of the acoustic cyclotron resonance. It is shown that
such peculiarities of the local geometry of the FS can lead to a significant
enhancement of both cyclotron resonance and geometric oscillations.
Characteristic features of the coupling of ultrasound to shortwave cyclotron
waves arising due to the local flattening of the FS are analyzed.
  PACS numbers 71.18.+y; 72.15.Gd; 72.15.-v",9911440v2
1999-12-15,Mechanical Mixing in Nonlinear Nanomechanical Resonators,"Nanomechanical resonators, machined out of Silicon-on-Insulator wafers, are
operated in the nonlinear regime to investigate higher-order mechanical mixing
at radio frequencies, relevant to signal processing and nonlinear dynamics on
nanometer scales. Driven by two neighboring frequencies the resonators generate
rich power spectra exhibiting a multitude of satellite peaks. This nonlinear
response is studied and compared to $n^{th}$-order perturbation theory and
nonperturbative numerical calculations.",9912278v1
2000-01-03,Signature of Dynamical Localization in the Lifetime Distribution of Wave-Chaotic Dielectric Resonators,"We consider the effect of dynamical localization on the lifetimes of the
resonances in open wave-chaotic dielectric cavities. We show that dynamical
localization leads to a log-normal distribution of the resonance lifetimes
which scales with the localization length in excellent agreement with the
results of numerical calculations for open rough microcavities.",0001017v1
2000-01-08,Resonances and Chaos in the Collective Oscillations of a Trapped Bose Condensate,"We investigate the collective oscillations of a Bose condensate in an
anisotropic harmonic trap. We analytically calculate the values of the trap
deformation for which the normal modes are in resonance. In presence of
low-order resonances, the amplitude dependence of frequencies is strongly
enhanced. We also study the transition to chaos of the collective modes as a
function of the trap anisotropy.",0001087v1
2000-02-18,Tomonaga-Luttinger features in the resonant Raman spectra of quantum wires,"The differential cross section for resonant Raman scattering from the
collective modes in a one dimensional system of interacting electrons is
calculated non-perturbatively using the bosonization method. The results
indicate that resonant Raman spectroscopy is a powerful tool for studying
Tomonaga-Luttinger liquid behaviour in quasi-one dimensional electron systems.",0002287v1
2000-05-24,Evidence For Heavy Hole and Light Hole Current Separation in P-Type Resonant Tunneling Diodes With Prewells,"We investigate the transport of holes through $AlAs/In_{.10}Ga_{.90}As$
resonant tunneling diodes which utilize $In_xGa_{1-x}As$ prewells in the
emitter with $x=0,.10,$ and $.20$. The data show an increase in peak current
and bias at resonance and a concurrent increase in the peak-to-valley ratio
with increasing x. We explain this enhancement in tunneling as due to
confinement (or localiz- ation) of charges in the prewell and the formation of
direct heavy(light) hole to heavy(light) hole conduction channels as a
consequence.",0005421v1
2000-07-12,Observation of resonance trapping in an open microwave cavity,"The coupling of a quantum mechanical system to open decay channels has been
theoretically studied in numerous works, mainly in the context of nuclear
physics but also in atomic, molecular and mesoscopic physics. Theory predicts
that with increasing coupling strength to the channels the resonance widths of
all states should first increase but finally decrease again for most of the
states. In this letter, the first direct experimental verification of this
effect, known as resonance trapping, is presented. In the experiment a
microwave Sinai cavity with an attached waveguide with variable slit width was
used.",0007201v1
2000-07-27,Microscopic theory for quantum mirages in quantum corrals,"Scanning tunneling microscopy permits to image the Kondo resonance of a
single magnetic atom adsorbed on a metallic surface. When the magnetic impurity
is placed at the focus of an elliptical quantum corral, a Kondo resonance has
been recently observed both on top of the impurity and on top of the focus
where no magnetic impurity is present. This projection of the Kondo resonance
to a remote point on the surface is referred to as quantum mirage. We present a
quantum mechanical theory for the quantum mirage inside an ideal quantum corral
and predict that the mirage will occur in corrals with shapes other than
elliptical.",0007445v1
2000-08-19,Phase synchronization and noise-induced resonance in systems of coupled oscillators,"We study synchronization and noise-induced resonance phenomena in systems of
globally coupled oscillators, each possessing finite inertia. The behavior of
the order parameter, which measures collective synchronization of the system,
is investigated as the noise level and the coupling strength are varied, and
hysteretic behavior is manifested. The power spectrum of the phase velocity is
also examined and the quality factor as well as the response function is
obtained to reveal noise-induced resonance behavior.",0008288v1
2000-09-22,Resonant tunneling through zero-dimensional impurity states: Effects of a finite temperature,"We have performed temperature dependent tunneling experiments through a
single impurity in an asymmetric vertical double barrier tunneling structure.
In particular in the charging direction we observe at zero magnetic field a
clear shift in the onset voltage of the resonant tunneling current through the
impurity. With a magnetic field applied the shift starts to disappear. The
experimental observations are explained in terms of resonant tunneling through
a spin degenerate impurity level.",0009349v1
2000-10-04,Smearing of Coulomb Blockade by Resonant Tunneling,"We study the Coulomb blockade in a grain coupled to a lead via a resonant
impurity level. We show that the strong energy dependence of the transmission
coefficient through the impurity level can have a dramatic effect on the
quantization of the grain charge. In particular, if the resonance is
sufficiently narrow, the Coulomb staircase shows very sharp steps even if the
transmission through the impurity at the Fermi energy is perfect. This is in
contrast to the naive expectation that perfect transmission should completely
smear charging effects.",0010068v1
2000-12-16,Spatiotemporal Stochastic Resonance in Fully Frustrated Josephson Ladders,"We consider a Josephson-junction ladder in an external magnetic field with
half flux quantum per plaquette. When driven by external currents, periodic in
time and staggered in space, such a fully frustrated system is found to display
spatiotemporal stochastic resonance under the influence of thermal noise. Such
resonance behavior is investigated both numerically and analytically, which
reveals significant effects of anisotropy and yields rich physics.",0012307v1
2001-01-25,Semiclassical quantization and resonance in spin tunnelling,"We derive a semiclassical quantization for a spin, study it for not too small
a spin quantum number (S>5), and compute the 2S+1 eigenvalues of a Hamiltonian
exhibiting resonant tunnelling as the magnetic field parallel to the anisotropy
axis is increased. Special attention is paid to the resonance condition. As a
corollary we prove that semiclassical quantization and quantum-mechanical
perturbation theory agree there where they should.",0101388v1
2001-03-07,Thermal Resonance in Signal Transmission,"We use temperature tuning to control signal propagation in simple
one-dimensional arrays of masses connected by hard anharmonic springs and with
no local potentials. In our numerical model a sustained signal is applied at
one site of a chain immersed in a thermal environment and the signal-to-noise
ratio is measured at each oscillator. We show that raising the temperature can
lead to enhanced signal propagation along the chain, resulting in thermal
resonance effects akin to the resonance observed in arrays of bistable systems.",0103152v1
2001-03-21,Suprathreshold stochastic resonance: suppression of noise by strong periodic signals,"We consider an overdamped Brownian motion in ""quartic"" potential subjected to
periodic driving. This system for the case of a weak periodic driving has been
intensively studied during past decade within the context of stochastic
resonance. We had demonstrated, that for the case of predominantly
suprathreshold driving the noise in the output signal is strongly suppressed at
certain frequency range: the signal-to-noise ratio demonstrates resonant
behavior as function of frequency.",0103448v2
2001-03-27,Coherent Effects under Suppressed Spontaneous Emission,"An ensemble of resonance atoms is considered, which are doped into a medium
with well developed polariton effect, when in the spectrum of polariton states
there is a band gap. If an atom with a resonance frequency inside the polariton
gap is placed into the medium, the atomic spontaneous emission is suppressed.
However, a system of resonance atoms inside the polariton gap can radiate when
their coherent interaction is sufficiently strong. Thus the suppression of
spontaneous emission for a single atom can be overcome by a collective of atoms
radiating coherently. Conditions when such collective effects can appear and
their dynamics are analysed.",0103554v1
2001-04-12,Fano and Kondo resonance in electronic current through nanodevices,"Electronic transport through a quantum dot strongly coupled to electrodes is
studied within a model with two conduction channels. It is shown that multiple
scattering and interference of transmitted waves through both channels lead to
Fano resonance associated with Kondo resonance. Interference effects are also
pronouncedly seen in transport through the Aharonov-Bohm ring with the Kondo
dot, where the current characteristics continuously evolve with the magnetic
flux.",0104217v3
2001-04-19,Experimental evidence of stochastic resonance without tuning due to non Gaussian noises,"In order to test theoretical predictions, we have studied the phenomenon of
stochastic resonance in an electronic experimental system driven by white non
Gaussian noise. In agreement with the theoretical predictions our main findings
are: an enhancement of the sensibility of the system together with a remarkable
widening of the response (robustness). This implies that even a single resonant
unit can reach a marked reduction in the need of noise tuning.",0104377v2
2001-06-18,Mechanism of pseudogap probed by a local impurity,"The response to a local strong non-magnetic impurity in the pseudogap phase
is examined in two distinctly different scenarios: phase-fluctuation (PF) of
pairing field and d-density-wave (DDW) order. In the PF scenario, the resonance
state is generally double-peaked near the Fermi level, and is abruptly
broadened by vortex fluctuations slightly above the transition temperature. In
the DDW scenario, the resonance is single-peaked and remains sharp up to
gradual intrinsic thermal broadening, and the resonance energy is analytically
determined to be at minus of the chemical potential.",0106327v4
2001-08-04,Magnetic Field Pinning of a Dynamic Electron-Spin-Resonance Line in a GaAs/AlGaAs Heterostructure,"Electrically detected electron spin resonance (ESR) is used to study the
hyperfine interaction of the two-dimensional electrons and the nuclei of the
host lattice in a GaAs/AlGaAs heterostructure. Under the microwave and radio-
frequency double excitations, we have observed that the ESR line can be pinned
in a very narrow range of magnetic field - in the vicinity of the nuclear
magnetic resonance (NMR) of the nuclei of the GaAs crystal. Our observations
suggest that this pinning effect is the result of a competition process between
the ESR induced dynamic nuclear polarization and the NMR induced
depolarization.",0108080v1
2001-09-17,Ferromagnetic resonance in periodic particle arrays,"We report measurements of the ferromagnetic resonance (FMR) spectra of arrays
of submicron size periodic particle arrays of permalloy produced by
electron-beam lithography. In contrast to plane ferromagnetic films, the
spectra of the arrays show a number of additional resonance peaks, whose
position depends strongly on the orientation of the external magnetic field and
the interparticle interaction. Time-dependent micromagnetic simulation of the
ac response show that these peaks are associated with coupled exchange and
dipolar spin wave modes",0109307v1
2001-10-22,What the resonance peak cannot do,"In certain cuprates, a spin 1 resonance mode is prominent in the magnetic
structure measured by neutron scattering. It has been proposed that this mode
is responsible for significant features seen in other spectroscopies, such as
photoemission and optical absorption, which are sensitive to the charge
dynamics, and even that this mode is the boson responsibile for ``mediating''
the superconducting pairing. We show that its small (measured) intensity and
weak coupling to electron-hole pairs (as deduced from the measured lifetime)
disqualifies the resonant mode from either proposed role.",0110478v1
2001-11-11,Electron (hole) paramagnetic resonance of spherical CdSe nanocrystals,"A new mechanism of electron paramagnetic resonance in spherical zinc-blende
semiconductor nanocrystals, based on the extended orbital motion of electrons
in the entire nanocrystal, is presented. Quantum confinement plays a crucial
role in making the resonance signal observable. The mechanism remains operative
in nanocrystals with uniaxially distorted shape. A theoretical model based on
the proposed mechanism is in good quantitative agreement with unusual ODMR
spectra observed in nearly spherical CdSe nanocrystals.",0111200v1
2001-11-14,Local-field distribution in resonant composites: Green's-function formalism,"The effective response depends sensitively on composite microstructure due to
large fluctuations in the local electric field. For metallic clusters embedded
in a dielectric host, the local field distributions are extremely inhomogeneous
in space around the metallic clusters due to quasi-static resonance, leading to
a large enhancement in the effective linear and nonlinear responses. In this
work, we propose a general method for computing the electric field of metallic
clusters near resonance via a perturbation formalism. We illustrate the method
by simple examples.",0111248v1
2001-11-15,Stochastic resonance in a model of opinion formation on small-world networks,"We analyze the phenomenon of stochastic resonance in an Ising-like system on
a small-world network. The system, which is subject to the combined action of
noise and an external modulation, can be interpreted as a stylized model of
opinion formation by imitation under the effects of a ``fashion wave''. Both
the amplitude threshold for the detection of the external modulation and the
width of the stochastic-resonance peak show considerable variation as the
randomness of the underlying small-world network is changed.",0111289v1
2001-11-27,Resonant Josephson current through a quantum dot,"We calculate the DC Josephson current through a semiconducting quantum dot
which is weakly coupled by tunnel barriers to two superconducting reservoirs. A
Breit-Wigner resonance in the conductance corresponds to a resonance in the
critical current, but with a different (non-lorentzian) lineshape.",0111505v1
2001-12-17,"Interplay of frequency-synchronization with noise: current resonances, giant diffusion and diffusion-crests","We elucidate how the presence of noise may significantly interact with the
synchronization mechanism of systems exhibiting frequency-locking. The response
of these systems exhibits a rich variety of behaviors, such as resonances and
anti-resonances which can be controlled by the intensity of noise. The
transition between different locked regimes provokes the development of a
multiple enhancement of the effective diffusion. This diffusion behavior is
accompanied by a crest-like peak-splitting cascade when the distribution of the
lockings is self-similar, as it occurs in periodic systems that are able to
exhibit a Devil's staircase sequence of frequency-lockings.",0112320v1
2002-01-07,Influence of the Barrier Shape on Resonant Activation,"The escape of a Brownian particle over a dichotomously fluctuating barrier is
investigated for various shapes of the barrier. The problem of resonant
activation is revisited with the attention on the effect of the barrier shape
on optimal value of the mean escape time in the system. The characteristic
features of resonant behavior are analyzed for barriers switching either
between different heights, or ""on"" and ""off"" positions. PACS number(s):
05.10-a, 02.50.-r, 82.20.-wj.",0201068v2
2002-01-14,Spin polarization contrast observed in GaAs by force-detected nuclear magnetic resonance,"We applied the recently developed technique of force-detected nuclear
magnetic resonance (NMR) to observe 71Ga, 69Ga, and 75As in GaAs. The nuclear
spin-lattice relaxation time is 21$\pm$5 min for 69Ga at $\sim 5$ K and 4.6
Tesla. We have exploited this long relaxation time to first create and then
observe spatially varying nuclear spin polarization within the sample,
demonstrating a new form of contrast for magnetic resonance force microscopy
(MRFM). Such nuclear spin contrast could be used to indirectly image electron
spin polarization in GaAs-based spintronic devices.",0201216v1
2002-02-12,Transmission Phase of an Isolated Coulomb-Blockade Resonance,"In two recent papers, O. Entin-Wohlman et al. studied the question: ``Which
physical information is carried by the transmission phase through a quantum
dot?'' In the present paper, this question is answered for an islolated
Coulomb-blockade resonance and within a theoretical model which is more closely
patterned after the geometry of the actual experiment by Schuster et al. than
is the model of O. Entin-Wohlman et al. We conclude that whenever the number of
leads coupled to the Aharanov-Bohm interferometer is larger than two, and the
total number of channels is sufficiently large, the transmission phase does
reflect the Breit-Wigner behavior of the resonance phase shift.",0202197v1
2002-02-28,"""Resonance"" phenomena in thermal diffusion processes in two-layer structures","The dependence on chopper frequency of the effective thermal diffusivity and
effective thermal conductivity in photoacoustic experiments is discussed. The
theoretical model of a two-layer structure at rear-surface illumination in the
high frequency limit is considered. It is shown that the effective thermal
diffusivity presents ``resonance'' while the effective thermal conductivity
sharply changes its magnitude and sign. Such ``resonant'' behavior strongly
depends on the surface thermal conductivities associated with the interface
thermal contacts.",0202539v1
2002-03-11,Oscillations of ultra-thin copper nanobridges at room temperature: Molecular dynamics simulations,"We have investigated several ultra-thin copper nanobridges between supporting
layers using a classical molecular dynamics simulation and a many-body
potential function of the second-moment approximation of tight-binding scheme.
This investigation has shown a part of the thermal properties of nanobridges,
the tension in the nanobridges, and the resonance of the nanobridges. When the
nanobridge has a well-defined structure, the resonant frequency is defined and
the phenomenon of resonance is in common with classical oscillation systems.",0203222v1
2002-04-26,Resonance Raman scattering in semiconductor quantum dots: Adiabatic vs. time-dependent perturbation theory,"The adiabatic theory of resonance one-phonon Raman scattering in
semiconductor nanocrystals is revised and extended with perturbative
non-adiabatic corrections, given by the Albrecht's B term. This theory is
confronted with the time-dependent perturbation approach, pointing at their
differences and similarities. It is shown that both theories are equivalent in
the limit of weak electron-phonon coupling and non-degenerate or uncoupled
resonant states. Evaluations of the A and B terms for the confined LO phonon in
CdSe and CdS nanocrystals are reported. These evaluations show that the B term
can usually be neglected.",0204583v1
2002-05-03,Spatial Solitons and Anderson Localization,"Stochastic (Anderson) localization is the spatial localization of the
wave-function of quantum particles in random media. We show, that a
corresponding phenomenon can stabilize spatial solitons in optical resonators:
spatial solitons in resonators with randomly distorted mirrors are more stable
than in perfect mirror resonators. We demonstrate the phenomenon numerically,
by investigating solitons in lasers with saturable absorber, and analytically
by deriving and analyzing coupled equations of spatially coherent and
incoherent field components.",0205061v2
2002-05-10,Stability of the two-dimensional Bose gases in the resonant regime,"We consider a two-dimensional Bose gas formed in a planar atomic trap in
conditions where the two-dimensional scattering length exceeds all other
microscopic length scales in the system and, accordingly, the gas parameter
assumes relatively high values. We show that, unlike in the three-dimensional
case, for sufficiently low areal densities the two-dimensional gas remains
stable against collapse even in the resonant regime. Furthermore, we evaluate
the three-body recombination rate that sets the upper limit for the life-time
of two-dimensional resonant atomic condensate.",0205210v2
2002-07-05,Autonomous stochastic resonance in fully frustrated Josephson-junction ladders,"We investigate autonomous stochastic resonance in fully frustrated
Josephson-junction ladders, which are driven by uniform constant currents. At
zero temperature large currents induce oscillations between the two ground
states, while for small currents the lattice potential forces the system to
remain in one of the two states. At finite temperatures, on the other hand,
oscillations between the two states develop even below the critical current;
the signal-to-noise ratio is found to display array-enhanced stochastic
resonance. It is suggested that such behavior may be observed experimentally
through the measurement of the staggered voltage.",0207154v1
2002-07-08,Quantum Entanglement of Flux Qubits via a Resonator,"We show that flux qubits can be efficiently entangled by inductive coupling
to a tunable resonant circuit, in the scheme reminiscent of atoms' entanglement
through the optical cavity mode. It is shown, in particular, that the
single-photon excitation of the resonator produces the pure Bell state of
qubits with the completely disentangled LC circuit.",0207214v2
2002-07-23,System size coherence resonance,"We show the existence of a system size coherence resonance effect for an
ensemble of globally coupled excitable systems. Namely, we demonstrate
numerically that the regularity in the signal emitted by an ensemble of
globally coupled Fitzhugh-Nagumo systems, under excitation by independent noise
sources, is optimal for a particular value of the number of coupled systems.
This resonance is shown through several different dynamical measures: the time
correlation function, correlation time and jitter.",0207553v1
2002-08-22,A scheme for electrical detection of spin resonance signal from a single electron trap,"We study a scheme for electrical detection of the spin resonance (ESR) of a
single electron trapped near a Field Effect Transistor (FET) conduction
channel. In this scheme, the resonant Rabi oscillations of the trapped electron
spin cause a modification of the average occupancy of a shallow trap, which can
be detected through the change in the FET channel resistivity. We show that the
dependence of the channel resistivity on the frequency of the rf field can have
either peak or dip at the Larmor frequency of the electron spin in the trap.",0208438v1
2002-08-30,Feshbach-resonance-induced atomic filamentation and quantum pair correlation in atom-laser-beam propagation,"We study the propagation of an atom laser beam through a spatial region with
a magnetic field tuned to a Feshbach resonance. Tuning the magnetic field below
the resonance produces an effective focusing Kerr medium that causes a
modulational instability of the atomic beam. Under appropriate circumstances,
this results in beam breakup and filamentation seeded by quasi-particle
fluctuations, and in the generation of correlated atomic pairs.",0208589v1
2002-09-04,Tuning p-wave interactions in an ultracold Fermi gas of atoms,"We have measured a p-wave Feshbach resonance in a single-component, ultracold
Fermi gas of potassium atoms. We have used this resonance to enhance the
normally suppressed p-wave collision cross-section to values larger than the
background s-wave cross-section between potassium atoms in different
spin-states. In addition to the modification of two-body elastic processes, the
resonance dramatically enhances three-body inelastic collisional loss.",0209071v1
2002-09-04,Resonant tunneling of interacting electrons in a one-dimensional wire,"We consider the conductance of a one-dimensional wire interrupted by a
double-barrier structure allowing for a resonant level. Using the
electron-electron interaction strength as a small parameter, we are able to
build a non-perturbative analytical theory of the conductance valid in a broad
region of temperatures and for a variety of the barrier parameters. We find
that the conductance may have a non-monotonic crossover dependence on
temperature, specific for a resonant tunneling in an interacting electron
system.",0209090v2
2002-09-11,Magnetic Anisotropy in La_0.8Sr_0.2MnO_3: Electron Spin Resonance,"We report on Ferromagnetic-Resonance experiments in a single crystal of
La_0.8Sr_0.2MnO_3 in the temperature range from 4 to 300 K. The observed
anisotropy of the resonance line changes on crossing the transition from the
orthorhombic O-phase to the rhombohedral R-phase at T~100 K and indicates a
reorientation of the spins at about 130 K.",0209257v1
2002-09-26,Isolated resonances in conductance fluctuations in ballistic billiards,"We study the isolated resonances occurring in conductance fluctuations of
ballistic electron systems with a classically mixed phase space. In particular,
we calculate the conductance and Wigner-Smith time as well as scattering states
and eigenstates of the open and closed cosine billiard, respectively. We
demonstrate that the observed isolated resonances and their scattering states
can be associated with eigenstates of the closed system. They can all be
categorized as hierarchical or regular, depending on where in a phase space
representation the corresponding eigenstates are concentrated.",0209606v1
2002-11-05,Magnetic fluctuations and resonant peak in cuprates: a microscopic theory,"The theory for the dynamical spin susceptibility within the t-J model is
developed, as relevant for the resonant magnetic peak and normal-state magnetic
response in superconducting (SC) cuprates. The analysis is based on the
equations of motion for spins and the memory-function presentation of magnetic
response where the main damping of the low-energy spin collective mode comes
from the decay into fermionic degrees of freedom. It is shown that the damping
function at low doping is closely related to the c-axis optical conductivity.
The analysis reproduces doping-dependent features of the resonant magnetic
scattering.",0211090v1
2002-11-21,Resonant tunnelling between Luttinger liquids: solvable case,"We discuss the conductance of a Luttinger liquid interrupted by a quantum dot
containing a single resonant level. Using bosonisation and re-fermionisation
methods, we find a mapping to a Kondo-type problem which possesses a
non-trivial Toulouse-type solvable point. At this point, we obtain an analytic
expression for the non-linear current-voltage characteristics and analyse the
differential conductance and the width of the resonance peak as functions of
bias and gate voltages, temperature, and barrier asymmetry. We also determine
the exact scaling function for the linear conductance.",0211474v1
2002-12-31,Memory-effect in glasses at low temperatures,"The dielectric constant of amorphous solids at low temperatures is governed
by the dynamics of tunneling systems, small groups of atoms which tunnel
between quasi equivalent potential minima. Recent experiments showed that at
temperatures below 20 mK various glasses exhibit memory for a previously
applied electric bias field. A first sweep of an electric bias field may
prepare resonant pairs of tunneling systems, which are temporarily formed
during the sweep, in metastable states. In subsequent sweeps the same resonant
pairs thus significantly contribute to the dielectric constant, leading to a
higher dielectric constant. We investigate the dynamics of resonant pairs
during a bias field sweep yielding a qualitative explanation of the memory
effect.",0301003v1
2003-01-06,The Effect of Ramsauer Type Transmission Resonances on the Conductance Modulation of Spin Interferometers,"We use a mean field approach to study the conductance modulation of gate
controlled semiconductor spin interferometers based on the Rashba spin-orbit
coupling effect. The conductance modulation is found to be mostly due to
Ramsauer type transmission resonances rather than the Rashba effect in typical
structures. This is because of significant reflections at the interferometer's
contacts due to large potential barriers and effective mass mismatch between
the contact material and the semiconductor. Thus, unless particular care is
taken to eliminate these reflections, any observed conductance modulation of
spin interferometers may have its origin in the Ramsauer resonances (which is
unrelated to spin) rather than the Rashba effect.",0301052v1
2003-02-11,Feshbach resonance in dense ultracold Fermi gases,"We propose a coherent framework allowing to deal with many-body effects in
dense ultracold Fermi gases in the presence of a Feshbach resonance. We show
that the simple effect of Pauli exclusion induces a strong modification of the
basic scattering properties, leading in particular to an energy dependence of
the effective scattering length on the scale of the chemical potential. This
results in a smearing of the Feshbach resonance and provides a natural
explanation for recent experimental findings.",0302209v1
2003-02-20,Feshbach resonance described by the boson fermion coupling,"We consider a possibility to describe the Feshbach resonance in terms of the
Boson Fermion (BF) model. Using such model we show that after a gradual
disentangling of the boson from fermion subsystem the resonant type scattering
between fermions is indeed generated. We decouple the subsystems via: (a) the
single step, and (b) the continuous canonical transformation. With the second
one we investigate the feedback effects effectively leading to the finite
amplitude of the scattering strength. We study them in detail in: the normal
$T>T_{c}$ and superconducting $T \leq T_{c}$ states.",0302406v1
2003-02-20,Toward creating isotropic microwave composites with negative refraction,"The properties of artificial isotropic microwave composites which would
possess simultaneously negative permittivity and permeability are studied
theoretically. Four kinds of composites are considered. Two of them concern
media with split-ring resonator particles with different particle arrangements.
The other two are realized with Omega particles. An analytical antenna model of
the electromagnetic behavior of a split-ring resonator (SRR) is suggested and
verified by numerical simulations. Next, material parameters of composite media
made with SRR or Omega particles are calculated. It is shown that the
Omega-composites are more prospective for obtaining negative real values of
permittivity and permeability than the split-ring resonators.",0302417v1
2003-02-21,High Temperature Superfluid and Feshbach Resonance,"We study an effective field theory describing cold fermionic atoms near a
Feshbach resonance. The theory gives a unique description of the dynamics in
the limit that the energy of the Feshbach resonance is tuned to be twice that
of the Fermi surface. We show that in this limit the zero temperature
superfluid condensate is of order the Fermi energy, and obtain a critical
temperature $T_C \simeq 0.43 T_F$",0302433v1
2003-02-26,Feedback cooling of a nanomechanical resonator,"Cooled, low-loss nanomechanical resonators offer the prospect of directly
observing the quantum dynamics of mesoscopic systems. However, the present
state of the art requires cooling down to the milliKelvin regime in order to
observe quantum effects. Here we present an active feedback strategy based on
continuous observation of the resonator position for the purpose of obtaining
these low temperatures. In addition, we apply this to an experimentally
realizable configuration, where the position monitoring is carried out by a
single-electron transistor. Our estimates indicate that with current technology
this technique is likely to bring the required low temperatures within reach.",0302529v1
2003-03-12,Shot Noise in Mesoscopic Systems with Resonance Andreev Tunneling,"The general scattering-matrix formalism is suggested for the description of
shot noise in single-channel quantum NS contacts in the presence of smeared
Andreev levels in the $eV<\Delta$ regime. It is shown that the noise spectral
density as a function of frequency shows a number of characteristic features
due to the presence of the Andreev resonances in the system. It turns out that,
by analyzing these singularities, one can determine the relative phases of the
Andreev reflection amplitudes corresponding to the neighboring resonances.",0303223v1
2003-04-08,Exploiting environmental resonances to enhance qubit quality factors,"We discuss dephasing times for a two-level system (including bias) coupled to
a damped harmonic oscillator. This system is realized in measurements on
solid-state Josephson qubits. It can be mapped to a spin-boson model with a
spectral function with an approximately Lorentzian resonance. We diagonalize
the model by means of infinitesimal unitary transformations (flow equations),
and calculate correlation functions, dephasing rates, and qubit quality
factors. We find that these depend strongly on the environmental resonance
frequency $\Omega$; in particular, quality factors can be enhanced
significantly by tuning $\Omega$ to lie below the qubit frequency $\Delta$.",0304177v1
2003-04-22,Loss of superfluidity in a Bose-Einstein condensate via forced resonant oscillations,"We predict the loss of superfluidity in a Bose-Einstein condensate in an
axially symmetric harmonic trap alone during resonant collective oscillations
via a classical dynamical transition. The forced resonant oscillation can be
initiated by (a) a periodic modulation of the atomic scattering length with a
frequency that equals twice the radial trapping frequency or multiples thereof,
or by (b) a periodic modulation of the radial trapping potential with a
frequency that equals the radial trapping frequency or multiples thereof.
Suggestion for future experiment is made.",0304490v2
2003-04-23,Extended molecules and geometric scattering resonances in optical lattices,"We develop a theory describing neutral atoms scattering at low energies in an
optical lattice. We show that for a repulsive interaction, as the microscopic
scattering length increases, the effective scattering amplitude approaches a
limiting value which depends only on the lattice parameters. In the case of
attractive interaction a geometric resonance occurs before reaching this limit.
Close to the resonance, the effective interaction becomes repulsive and
supports a weakly bound state, which can extend over several lattice sites.",0304527v1
2003-05-07,Voltage-Controlled Spin Selection in a Magnetic Resonant Tunnelling Diode,"We have fabricated all II-VI semiconductor resonant tunneling diodes based on
the (Zn,Mn,Be)Se material system, containing dilute magnetic material in the
quantum well, and studied their current-voltage characteristics. When subjected
to an external magnetic field the resulting spin splitting of the levels in the
quantum well leads to a splitting of the transmission resonance into two
separate peaks. This is interpreted as evidence of tunneling transport through
spin polarized levels, and could be the first step towards a voltage controlled
spin filter.",0305124v1
2003-05-15,Large Splitting of the Cyclotron Resonance Line in AlGaN/GaN Heterostructures,"Cyclotron-resonance (CR) measurements on two-dimensional (2D) electrons in
AlGaN/GaN heterojunctions reveal large splittings (up to 2 meV) of the CR line
for all investigated densities, $n_{2D}$, from 1 to $4\times 10^{12}cm^{-2}$
over wide ranges of magnetic field. The features resemble a level anti-crossing
and imply a strong interaction with an unknown excitation of the solid. The
critical energy of the splitting varies from 5 to 12 meV and as
$\sqrt{n_{2D}}$. The phenomenon resembles data from AlGaAs/GaAs whose origin
remains unresolved. It highlights a lack of basic understanding of a very
elementary resonance in solids.",0305358v1
2003-05-17,Resonant scattering of solitons,"We study the scattering of solitons in the nonlinear Schroedinger equation on
local inhomogeneities which may give rise to resonant transmission and
reflection. In both cases, we derive resonance conditions for the soliton's
velocity. The analytical predictions are tested numerically in regimes
characterized by various time scales. Special attention is paid to intermode
interactions and their effect on coherence, decoherence and dephasing of
plane-wave modes which build up the soliton.",0305410v1
2003-05-29,Image resonance in the many-body density of states at a metal surface,"The electronic properties of a semi-infinite metal surface without a bulk gap
are studied by a formalism able to account for the continuous spectrum of the
system. The density of states at the surface is calculated within the $GW$
approximation of many-body perturbation theory. We demonstrate the presence of
an unoccupied surface resonance peaked at the position of the first image
state. The resonance encompasses the whole Rydberg series of image states and
cannot be resolved into individual peaks. Its origin is the shift in spectral
weight when many-body correlation effects are taken into account.",0305678v1
2003-06-04,The Orbital Order Parameter in La0.95Sr0.05MnO3 probed by Electron Spin Resonance,"The temperature dependence of the electron-spin resonance linewidth in
La0.95Sr0.05MnO3 has been determined and analyzed in the paramagnetic regime
across the orbital ordering transition. From the temperature dependence and the
anisotropy of linewidth and $g$-value the orbital order can be unambiguously
determined via the mixing angle of the wave functions of the $e_{\rm
g}$-doublet. The linewidth shows a similar evolution with temperature as
resonant x-ray scattering results.",0306088v1
2003-06-16,Fano Lineshapes Revisited: Symmetric Photoionization Peaks from Pure Continuum Excitation,"In a photoionization spectrum in which there is no excitation of the discrete
states, but only the underlying continuum, we have observed resonances which
appear as symmetric peaks, not the commonly expected window resonances.
Furthermore, since the excitation to the unperturbed continuum vanishes, the
cross section expected from Fano's configuration interaction theory is
identically zero. This shortcoming is removed by the explicit introduction of
the phase shifted continuum, which demonstrates that the shape of a resonance,
by itself, provides no information about the relative excitation amplitudes to
the discrete state and the continuum.",0306420v1
2003-06-18,Quantum limited sensitivity of SET-based displacement detectors,"We consider a model of a quantum-mechanical resonator capacitively coupled to
a single electron transistor (SET). The tunnel current in the SET is modulated
by the vibrations of the resonator, and thus the system operates as a
displacement detector. We analyze the effect of the back-action noise of charge
fluctuations in the SET onto the dynamics of the resonator and evaluate the
displacement sensitivity of the system. The relation between the ""classical""
and ""quantum"" parts of the SET charge noise and their effect on the measured
system are also discussed.",0306480v1
2003-06-29,Laser cooling of a nanomechanical resonator mode to its quantum ground state,"We show that it is possible to cool a nanomechanical resonator mode to its
ground state. The proposed technique is based on resonant laser excitation of a
phonon sideband of an embedded quantum dot. The strength of the sideband
coupling is determined directly by the difference between the electron-phonon
couplings of the initial and final states of the quantum dot optical
transition. Possible applications of the technique we describe include
generation of non-classical states of mechanical motion.",0306724v1
2003-07-02,Gain without inversion in a biased superlattice,"Intersubband transitions in a superlattice under homogeneous electric field
is studied within the tight-binding approximation. Since the levels are
equi-populated, the non-zero response appears beyond the Born approximation.
Calculations are performed in the resonant approximation with scattering
processes exactly taken into account. The absorption coefficient is equal zero
for the resonant excitation while a negative absorption (gain without
inversion) takes place below the resonance. A detectable gain in the THz
spectral region is obtained for the low-doped $GaAs$-based superlattice and
spectral dependencies are analyzed taking into account the interplay between
homogeneous and inhomogeneous mechanisms of broadening.",0307061v1
2003-07-21,Nuclear Magnetic Resonance in a Ferromagnet-Semiconductor Heterostructure,"We report the observation of nuclear magnetic resonance (NMR) in a
ferromagnet-semiconductor heterostructure in the presence of a spin-polarized
current. Spin-polarized electrons injected from a metallic ferromagnet generate
a large nuclear spin population in a GaAs quantum well by dynamic polarization.
The characteristic time for the polarization process is approximately 20 sec,
and the nuclear polarization can persist for several minutes after the current
is turned off. Resonant depolarization is observed in the presence of an AC
magnetic field or when the injection current is modulated at the NMR frequency.",0307512v1
2003-08-24,Why only half of the fermionic atoms were converted to molecules by a Feshbach resonance?,"In some recent experiments an ultracold gas of $^{40}$K$_2$ (or $^{6}$Li$_2$)
molecules has been produced from a degenerate two-component Fermi gas of
$^{40}$K (or $^{6}$Li) atoms by adiabatic passage through a Feshbach resonance.
The maximum atom-molecule transfer efficiency is reported to be about 50%. We
propose a simple microscopic model to characterize the ground state of the gas
in the vicinity of the resonance, and show that the term describing the
atom-molecule coupling is responsible for the observed efficiency 50%. Our
result also suggests that the experiments have produced a molecular condensate.",0308474v1
2003-08-26,Cyclotron Resonance of an Interacting Polaron Gas in a Quantum Well. Magneto-Plasmon-Phonon Mixing,"Cyclotron-resonance (CR) spectra of a gas of interacting polarons confined in
a GaAs/AlAs quantum well are theoretically investigated taking into account the
magneto-plasmon-phonon mixing and band nonparabolicity. Contributions of
different magneto-plasmon-phonon modes to the total magneto-polaron coupling
strength are investigated as a function of the electron density. It is
confirmed theoretically, that the resonant magneto-polaron coupling in a
high-density GaAs/AlAs quantum well occurs near the GaAs TO-phonon frequency
rather than near the GaAs LO-phonon frequency. Calculated CR spectra are in
agreement with recent experimental data.",0308553v1
2003-09-05,Direct observation by resonant tunneling of the B^+ level in a delta-doped silicon barrier,"We observe a resonance in the conductance of silicon tunneling devices with a
delta-doped barrier. The position of the resonance indicates that it arises
from tunneling through the B^+ state of the boron atoms of the delta-layer.
Since the emitter Fermi level in our devices is a field-independent reference
energy, we are able to directly observe the diamagnetic shift of the B^+ level.
This is contrary to the situation in magneto-optical spectroscopy, where the
shift is absorbed in the measured ionization energy.",0309139v1
2003-09-15,Impurity resonances in the mixed state of high-Tc superconductors,"We study the quasiparticle resonance states near strong impurities in the
mixed state of a d-wave superconductor. These states give rise to zero-bias
peaks in the local density of states, observed in scanning tunneling microscopy
experiments. The field dependence of the peaks is obtained by averaging with
respect to the spatially non-uniform Doppler shifts in the energy of
excitations. The hybridization of the magnetic field-induced nodal
quasiparticles with the impurity resonances results in the suppression and
broadening of the zero-bias peaks. The height of the peaks is found to scale as
\sqrt{Hc2/H}. The magnetic field response of the peaks is shown to be strongly
dependent on the field orientation.",0309355v1
2003-09-23,Fano interference and cross-section fluctuations in molecular photodissociation,"We derive an expression for the total photodissociation cross section of a
molecule incorporating both indirect processes that proceed through excited
resonances, and direct processes. We show that this cross section exhibits
generalized Beutler-Fano line shapes in the limit of isolated resonances.
Assuming that the closed system can be modeled by random matrix theory, we
derive the statistical properties of the photodissociation cross section and
find that they are significantly affected by the direct processes. We identify
a unique signature of the direct processes in the cross-section distribution in
the limit of isolated resonances.",0309521v1
2003-10-08,Regular and Random Magnetic Resonance Force Microscopy Signal with a Cantilever Oscillating Parallel to a Sample Surface,"We study theoretically the magnetic resonance force microscopy (MRFM) in
oscillating cantilever-driven adiabatic reversals (OSCAR) technique, for the
case when the cantilever tip oscillates parallel to the surface of a sample.
The main contribution to the MRFM signal is associated with a part of the
resonance slice near the surface of the sample. The regular (approximately
exponential) decay of the MRFM signal is followed by the non-dissipating random
signal. The Fourier spectrum of the random signal has a characteristic peak
which can be used for the identification of the signal.",0310187v1
2003-10-29,Understanding the Fano Resonance : through Toy Models,"The Fano Resonance, involving the mixing between a quasi-bound `discrete'
state of an inelastic channel lying in the continuum of scattering states
belonging to the elastic channel, has several subtle features. The underlying
ideas have recently attracted attention in connection with interference effects
in quantum wires and mesoscopic transport phenomena. Simple toy models are
provided in the present study to illustrate the basics of the Fano resonance in
a simple and tractable setting.",0310692v1
2003-11-24,Dissipation in Nanocrystalline-Diamond Nanomechanical Resonators,"We have measured the dissipation and frequency of nanocrystalline-diamond
nanomechanical resonators with resonant frequencies between 13.7 MHz and 157.3
MHz, over a temperature range of 1.4-274 K. Using both magnetomotive network
analysis and a novel time-domain ring-down technique, we have found the
dissipation in this material to have a temperature dependence roughly following
T^0.2, with Q^-1 = 10^-4 at low temperatures. The frequency dependence of a
large dissipation feature at ~35-55 K is consistent with thermal activation
over a 0.02 eV barrier with an attempt frequency of 10 GHz.",0311554v1
2003-11-25,Resonant Raman scattering in mercurate single crystals,"We report resonant electronic Raman scattering in optimally doped single
layer HgBa$_2$CuO$_{4+\delta}$ (Hg-1201) and trilayer
HgBa$_2$Ca$_2$Cu$_3$O$_{8+\delta}$ (Hg-1223) single crystals. Analysis of the
$B_{1g}$ and B$_{2g}$ channels in the superconducting state of Hg-1201
advocates for a gap having d-wave symmetry. In addition a resonant study
$B_{1g}$ pair-breaking peak and the $A_{1g}$ peak suggests that the $A_{1g}$
peak is not directly related to the d-wave superconducting gap amplitude.
Comparison with trilayer Hg-1223 demonstrates the universal behavior of this
two energy scales in optimally doped cuprates.",0311579v1
2003-12-01,"""Bloch oscillations"" in the Mott-insulator regime","We study the dynamical response of cold interacting atoms in the Mott
insulator phase to a static force. As shown in the experiment by M. Greiner et.
al., Nature \textbf{415}, 39 (2002), this response has resonant character, with
the main resonance defined by coincidence of Stark energy and on-site
interaction energy. We analyse the dynamics of the atomic momentum
distribution, which is the quantity measured in the experiment, for near
resonant forcing. The momentum distribution is shown to develop a recurring
interference pattern, with a recurrence time which we define in the paper.",0312024v1
2003-12-22,Coulomb-Modified Fano Resonance in a One-Lead Quantum Dot,"We investigate a tunable Fano interferometer consisting of a quantum dot
coupled via tunneling to a one-dimensional channel. In addition to Fano
resonance, the channel shows strong Coulomb response to the dot, with a single
electron modulating channel conductance by factors of up to 100. Where these
effects coexist, lineshapes with up to four extrema are found. A model of
Coulomb-modified Fano resonance is developed and gives excellent agreement with
experiment.",0312571v2
2004-01-12,Generalized Friedel sum rule and anomalies of the mobility due to the resonant scattering of electrons by donor impurities in semiconductors,"On the basis of Friedel approach the theoretical description of the effects
of resonance scattering of conduction electrons by donor impurities in
semiconductors with allowance for the stabilization of electron concentration
in coinciding the Fermi energy with the resonance level energy has been
developed. It has been shown that such a stabilization gives rise to the
appearance of maximum in concentration dependence and to its related anomalies
of temperature dependences of electron mobility. The advantage of the
application of the approach based on the proposed theory to the interpretation
of experimental data on mercury selenide with iron impurities is discussed.
PACS: 72.20.Dp; 72.20.Fr Keywords: semiconductors, impurities in
semiconductors, electron states, electron transport",0401174v1
2004-01-22,Spin fluctuations in the quasi-two dimensional Heisenberg ferromagnet GdI_2 studied by Electron Spin Resonance,"The spin dynamics of GdI_2 have been investigated by ESR spectroscopy. The
temperature dependences of the resonance field and ESR intensity are well
described by the model for the spin susceptibility proposed by Eremin et al.
[Phys. Rev. B 64, 064425 (2001)]. The temperature dependence of the resonance
linewidth shows a maximum similar to the electrical resistance and is discussed
in terms of scattering processes between conduction electrons and localized
spins.",0401415v1
2004-02-05,Resonance-like electrical control of electron spin for microwave measurement,"We demonstrate that the spin-polarized electron current can interact with a
microwave electric field in a resonant manner. The spin-orbit interaction gives
rise to an effective magnetic field proportional to the electric current. In
the presence of both dc and ac electric field components, electron spin
resonance occurs if the ac frequency matches with the spin precession frequency
that is controlled by the dc field. In a device consisting of two
spin-polarized contacts connected by a two-dimensional channel, this mechanism
allows electrically tuned detection of the ac signal frequency and amplitude.
For GaAs, such detection is effective in the frequency domain around tens of
gigahertz.",0402172v1
2004-02-26,Acoustic Phonon-Assisted Resonant Tunneling via Single Impurities,"We perform the investigations of the resonant tunneling via impurities
embedded in the AlAs barrier of a single GaAs/AlGaAs heterostructure. In the
$I(V)$ characteristics measured at 30mK, the contribution of individual donors
is resolved and the fingerprints of phonon assistance in the tunneling process
are seen. The latter is confirmed by detailed analysis of the tunneling rates
and the modeling of the resonant tunneling contribution to the current.
Moreover, fluctuations of the local structure of the DOS (LDOS) and Fermi edge
singularities are observed.",0402660v1
2004-03-28,A Josephson junction as a detector of Poissonian charge injection,"We propose a scheme of measuring the non-Gaussian character of noise by a
hysteretic Josephson junction in the macroscopic quantum tunnelling (MQT)
regime. We model the detector as an (under)damped $LC$ resonator. It transforms
Poissonian charge injection into current through the detector, which samples
the injection statistics over a floating time window of length $\sim Q/\omega
_{\rm J}$, where $Q$ is the quality factor of the resonator and $\omega_{\rm
J}$ its resonance frequency. This scheme ought to reveal the Poisson character
of charge injection in a detector with realistic parameters.",0403673v1
2004-04-06,Josephson Plasma Resonance in $Bi_2 Sr_2 Ca Cu_2 O_{8+y}$ with Spatially Dependent Interlayer-Phase Coherence,"We study the Josephson plasma resonance (JPR) in
Bi$_2$Sr$_2$CaCu$_2$O$_{8+y}$ (BSCCO) with spatially dependent interlayer-phase
coherence (IPC). The half-irradiated BSCCO (HI-BSCCO), in which columnar
defects are introduced only in a half of the sample, shows several resonance
peaks, which are not simple superposition of the peaks in irradiated- and
pristine-parts. JPR in HI-BSCCO changes its character from irradiated- to
pristine-type at a crossover frequency ($\omega_{cr}$). We demonstrate that the
one-dimensional \LSGE, which takes into account the spatial dependence of IPC,
can reproduce most of the experimental findings including the presence of
$\omega_{cr}$.",0404120v1
2004-04-19,Coherent molecular bound states of bosons and fermions near a Feshbach resonance,"We analyze molecular bound states of atomic quantum gases near a Feshbach
resonance. A simple, renormalizable field theoretic model is shown to have
exact solutions in the two-body sector, whose binding energy agrees well with
observed experimental results in both Bosonic and Fermionic cases. These
solutions, which interpolate between BEC and BCS theories, also provide a more
general variational ansatz for resonant superfluidity and related problems.",0404429v3
2004-07-19,Nonlinear Resonant Transport of Bose Einstein Condensates,"The coherent flow of a Bose-Einstein condensate through a quantum dot in a
magnetic waveguide is studied. By the numerical integration of the
time-dependent Gross-Pitaevskii equation in presence of a source term, we
simulate the propagation process of the condensate through a double barrier
potential in the waveguide. We find that resonant transport is suppressed in
interaction-induced regimes of bistability, where multiple scattering states
exist at the same chemical potential and the same incident current. We
demonstrate, however, that a temporal control of the external potential can be
used to circumvent this limitation and to obtain enhanced transmission near the
resonance on experimentally realistic time scales.",0407488v1
2004-08-24,Inelastic light scattering and the off-resonance approximation,"Inelastic (Raman) light scattering intensities for a 42-electron quantum dot
under off-resonance conditions and in different spin and angular momentum
channels are computed in order to test whether final collective states become
the dominant peaks in the process. The results of the calculations set a limit
to the spread use of the off-resonant approximation for the theoretical
description of Raman processes.",0408510v1
2004-09-04,Pure nuclear quadrupole resonance determination of the electric field gradient asymmetry for broad lines (and application to YBa2Cu3O7),"We present an angle dependent nuclear quadrupole resonance (ADNQR) method to
determine the electric field gradient asymmetry parameter eta in systems where
the resonance line is so broad that the radio frequency field can excite only a
portion of the nuclear spins. In this situation the recently developed
spectroscopic methods are not applicable. ADNQR is useful for single crystals
and oriented powders, and, for small eta determines eta^4. Therefore, it can be
used to evaluate fluctuations in eta due to inhomogeneities. We demonstrate the
application of ADNQR experimentally to oriented superconducting YBa2Cu3O7
powder.",0409101v1
2004-09-05,Bias voltage controlled magnetization switch in ferromagnetic semiconductor resonant tunneling diodes,"We predict that the Curie temperature of a ferromagnetic resonant tunneling
diode will decrease abruptly, by approximately a factor of two, when the
downstream chemical potential falls below the quantum well resonance energy.
This property follows from elementary quantum transport theory notions combined
with a mean field description of diluted magnetic semiconductor ferromagnetism.
We illustrate this effect by solving coupled non-equilibrium Green's function,
magnetic mean-field, and electrostatic Poisson equations self-consistently to
predict the bias voltage and temperature dependence of the magnetization of a
model system.",0409106v2
2004-09-07,IV-VI resonant cavity enhanced photodetectors for the midinfrared,"A resonant-cavity enhanced detector operating in the mid-infrared at a
wavelength around 3.6 micron is demonstrated. The device is based on a
narrow-gap lead salt heterostructure grown by molecular beam epitaxy. Below 140
K, the photovoltage clearly shows a single narrow cavity resonance, with a
relative line width of only 2 % at 80 K.",0409153v1
2004-09-23,Atom-molecule theory of broad Feshbach resonances,"We derive the atom-molecule theory for an atomic gas near a broad Feshbach
resonance, where the energy dependence of the atom-molecule coupling becomes
crucial for understanding experimental results. We show how our many-body
theory incorporates the two-atom physics exactly. In particular, we calculate
the magnetic moment of a two-component gas of ^{6}Li atoms for a wide range of
magnetic fields near the broad Feshbach resonance at about 834 Gauss. We find
excellent agreement with the experiment of Jochim et al. [Phys. Rev. Lett. 91,
240402 (2003)].",0409621v1
2004-10-08,Spin-dependent resonant tunneling in symmetrical double-barrier structure,"A theory of resonant spin-dependent tunneling has been developed for
symmetrical double-barrier structures grown of non-centrosymmetrical
semiconductors. The dependence of the tunneling transparency on the spin
orientation and the wave vector of electrons leads to (i) spin polarization of
the transmitted carriers in an in-plane electric field, (ii) generation of an
in-plane electric current under tunneling of spin-polarized carriers. These
effects originated from spin-orbit coupling-induced splitting of the resonant
level have been considered for double-barrier tunneling structures.",0410198v1
2004-10-19,Zero-field splitting of Kondo resonances in a carbon nanotube quantum dot,"We present low-temperature electron transport measurements on a single-wall
carbon nanotube quantum dot exhibiting Kondo resonances at low temperature.
Contrary to the usual behavior for the spin-1/2 Kondo effect we find that the
temperature dependence of the zero bias conductance is nonmonotonic. In
nonlinear transport measurements low-energy splittings of the Kondo resonances
are observed at zero magnetic field. We suggest that these anomalies reflect
interactions between the nanotube and a magnetic (catalyst) particle. The
nanotube device may effectively act as a ferromagnetically contacted Kondo dot.",0410467v2
2004-10-25,Sweeping a molecular Bose-Einstein condensate across a Feshbach resonance,"We consider the dissociation of a molecular Bose-Einstein condensate during a
magnetic-field sweep through a Feshbach resonance that starts on the molecular
side of the resonance and ends on the atomic side. In particular, we determine
the energy distribution of the atoms produced after the sweep. We find that the
shape of the energy distribution strongly depends on the rate of the
magnetic-field sweep, in a manner that is in good agreement with recent
experiments.",0410648v1
2004-10-27,Crossover in Broad Feshbach Resonance with Energy-Dependent Coupling,"This paper has been withdrawn by the authors as the recent measurement of the
closed channel population for Li6 [Partridge et al., cond-mat/0505353]
indicates that the cutoff energy is still much larger than any other relevant
energy scales for this broad Feshbach resonance.",0410685v3
2004-11-12,Kondo resonance for orbitally degenerate systems,"Formation of the Kondo state in general two-band Anderson model has been
investigated within the numerical renormalization group (NRG) calculations. The
Abrikosov-Suhl resonance is essentially asymmetric for the model with one
electron per impurity (quarter filling case) in contrast with the one-band
case. An external magnetic (pseudo-magnetic) field breaking spin (orbital)
degeneracy leads to asymmetric splitting and essential broadening of the
many-body resonance. Unlike the standard Anderson model, the ``spin up'' Kondo
peak is pinned against the Fermi level, but not suppressed by magnetic field.",0411323v1
2004-11-22,On stochastic switching of bistable resonant-tunneling structures via nucleation,"We estimate the critical size of the initial nucleus of the low current state
in a bistable resonant tunneling structure which is needed for this nucleus to
develop into a lateral switching front. Using the results obtained for
deterministic switching fronts, we argue that for realistic structural
parameters the critical nucleus has macroscopic dimensions and therefore is too
large to be created by stochastic electron noise.",0411546v1
2004-12-14,Nonlinear Fano resonance and bistable wave transmission,"We consider a discrete model that describes a linear chain of particles
coupled to a single-site defect with instantaneous Kerr nonlinearity. We show
that this model can be regarded as a nonlinear generalization of the familiar
Fano-Anderson model, and it can generate the amplitude depended bistable
resonant transmission or reflection. We identify these effects as the nonlinear
Fano resonance, and study its properties for continuous waves and pulses.",0412341v1
2004-12-21,"EPR study of some rare-earth ions (Dy3+, Tb3+ and Nd3+) in YBa2Cu3O6 compound","We investigate the low temperature X-band electron paramagnetic resonance
(EPR) of YBa2Cu3O6 compounds with x = 6.0 doped with Dy3+, Tb3+, and Nd3+. The
EPR spectra of Dy3+ and Tb3+ have been identified. The EPR of Tb3+ is used also
to study the effect of suppression of high Tc superconductivity. The EPR of
Nd3+ is probably masked by the intense resonance of Cu2+. All experimental EPR
results compare well with theoretical estimations.",0412567v1
2004-12-30,Enhancement of Coherent Response by Quenched Disorder,"We investigate the effects of quenched disorder on the coherent response in a
driven system of coupled oscillators. In particular, the interplay between
quenched noise and periodic driving is explored, with particular attention to
the possibility of resonance. The phase velocity is examined as the response of
the system; revealed is the enhancement of the fraction of oscillators locked
to the periodic driving, displaying resonance behavior. It is thus concluded
that resonance behavior may also be induced by quenched disorder which does not
have time-dependent correlations.",0412752v1
2005-01-11,Nonlinear Coupling in Nb/NbN Superconducting Microwave Resonators,"In this experimental study we show that the coupling between Nb/NbN
superconducting microwave resonators and their feedline can be made amplitude
dependent. We employ this mechanism to tune the resonators into critical
coupling condition, a preferable mode of operation for a wide range of
applications. Moreover we examine the dependence of critical coupling state on
other parameters such as temperature and magnetic field. Possible novel
applications based on such nonlinear coupling are briefly discussed.",0501236v1
2005-01-24,Resonant nonlinear quantum transport for a periodically kicked Bose condensate,"Our realistic numerical results show that the fundamental and higher-order
quantum resonances of the delta-kicked rotor are observable in state-of-the-art
experiments with a Bose condensate in a shallow harmonic trap, kicked by a
spatially periodic optical lattice. For stronger confinement,
interaction-induced destruction of the resonant motion of the kicked harmonic
oscillator is predicted.",0501565v2
2005-01-26,High-field optically detected nuclear magnetic resonance in GaAs,"A method for high-field optically detected nuclear magnetic resonance (ODNMR)
is developed sensitive to 10**8 nuclei. Nuclear spin transitions are induced
using a radio frequency coil and detected through Faraday rotation
spectroscopy. Unlike conventional ODNMR, which is limited to low fields and
relies on the measurement of time-averaged luminescence polarization, this
technique monitors nuclear polarization through time-resolved measurements of
electron spin dynamics. Measurements in a (110) GaAs quantum well reveal Ga-69,
Ga-71, and As-75 resonances and their quadrupolar splittings while resolving
changes in nuclear polarization of 0.02%.",0501652v1
2005-02-10,Adsorption-induced constraint on delocalization of electron states in an Au chain on NiAl(110),"We have carried out a density functional study of the localized constraint on
the delocalized, unoccupied resonance states in a mono atomic Au chain on a
NiAl(110) surface by adsorption of a CO molecule on one of the adatoms in the
chain. This constraint was observed recently by scanning tunnelling microscopy
and spectroscopy. The repulsive interaction of the occupied 5${\sigma}$
molecular state with the unoccupied, resonance state in a Au adatom in the
chain is found to break the degeneracy of the Au adatom-induced resonance
states and to disrupt their delocalization in the chain.",0502258v1
2005-02-10,Coherent Population Trapping in a Feshbach-Resonant Cesium Condensate,"Recent experiments with Feshbach-resonant cesium Bose-Einstein condensates
have led to unexplained molecule formation: a sudden switch of the magnetic
field to its resonance value, followed by a finite hold time and another sudden
switch to magnetic field values below threshold, converts about a third of the
initial condensate atoms into molecules. Based on a model of coherent
conversion between an atomic condensate, a molecular condensate, and
magnetodissociated noncondensate atom pairs of equal and opposite momentum, we
find that population trapping is strongly implicated as the physical mechanism
responsible for molecule formation in switch experiments.",0502269v1
2005-03-30,On the transmission of light through a single rectangular hole,"In this Letter we show that a single rectangular hole exhibits transmission
resonances that appear near the cutoff wavelength of the hole waveguide. For
light polarized with the electric field pointing along the short axis, it is
shown that the normalized-to-area transmittance at resonance is proportional to
the ratio between the long and short sides, and to the dielectric constant
inside the hole. Importantly, this resonant transmission process is accompanied
by a huge enhancement of the electric field at both entrance and exit
interfaces of the hole. These findings open the possibility of using
rectangular holes for spectroscopic purposes or for exploring non-linear
effects.",0503709v1
2005-04-23,Exciton resonances quench the photoluminescence of zigzag carbon nanotubes,"We show that the photoluminescence intensity of single-walled carbon
nanotubes is much stronger in tubes with large chiral angles - armchair tubes -
because exciton resonances make the luminescence of zigzag tubes intrinsically
weak. This exciton-exciton resonance depends on the electronic structure of the
tubes and is found more often in nanotubes of the +1 family. Armchair tubes do
not necessarily grow preferentially with present growth techniques; they just
have stronger luminescence. Our analysis allows to normalize photoluminescence
intensities and find the abundance of nanotube chiralities in macroscopic
samples.",0504607v1
2005-05-18,Resonant tunneling magnetoresistance in epitaxial metal-semiconductor heterostructures,"We report on resonant tunneling magnetoresistance via localized states
through a ZnSe semiconducting barrier which can reverse the sign of the
effective spin polarization of tunneling electrons. Experiments performed on
Fe/ZnSe/Fe planar junctions have shown that positive, negative or even its
sign-reversible magnetoresistance can be obtained, depending on the bias
voltage, the energy of localized states in the ZnSe barrier and spatial
symmetry. The averaging of conduction over all localized states in a junction
under resonant condition is strongly detrimental to the magnetoresistance.",0505432v1
2005-05-27,Dynamics of the quantum Duffing oscillator in the driving induced bistable regime,"We investigate the nonlinear response of an anharmonic monostable quantum
mechanical resonator to strong external periodic driving. The driving thereby
induces an effective bistability in which resonant tunneling can be identified.
Within the framework of a Floquet analysis, an effective Floquet-Born-Markovian
master equation with time-independent coefficients can be established which can
be solved straightforwardly. Various effects including resonant tunneling and
multi-photon transitions will be described. Our model finds applications in
nano-electromechanical devices such as vibrating suspended nano-wires as well
as in non-destructive read-out procedures for superconducting quantum bits
involving the nonlinear response of the read-out SQUID.",0505671v1
2005-05-30,Dynamics of Bose-Einstein Condensates in One-Dimensional Optical Lattices in the Presence of Transverse Resonances,"The dynamics of Bose-Einstein condensates in the lowest energy band of a
one-dimensional optical lattice is generally disturbed by the presence of
transversally excited resonant states. We propose an effective one-dimensional
theory which takes these resonant modes into account and derive variational
equations for large-scale dynamics. Several applications of the theory are
discussed and a novel type of ""triple soliton"" is proposed, which consists of a
superposition of a wavepacket at the upper band edge and two transversally
excited wavepackets which are displaced in quasi-momentum space.",0505729v1
2005-06-07,Simple Mean-Field Theory for a Zero-Temperature Fermi Gas at a Feshbach Resonance,"We present a simple two-channel mean field theory for a zero-temperature
two-component Fermi gas in the neighborhood of a Feshbach resonance. Our
results agree with recent experiments on the bare-molecule fraction as a
function of magnetic field [Partridge et al., cond-mat/0505353]. Even in this
strongly-coupled gas of Li-6, the experimental results depend on the structure
of the molecules formed in the Feshbach resonance and, therefore, are not
universal.",0506183v1
2005-06-13,Dressed Feshbach molecules in the BEC-BCS crossover,"We present the RPA theory of the BEC-BCS crossover in an atomic Fermi gas
near a Feshbach resonance that includes the relevant two-body atomic physics
exactly. This allows us to determine the probability $Z$ for the dressed
molecules in the Bose-Einstein condensate to be in the closed channel of the
Feshbach resonance and to compare with the recent experiments of Partridge {\it
et al.} [cond-mat/0505353] with $^{6}$Li. We determine for this extremely broad
resonance also the condensate density of the dressed molecules throughout the
BEC-BCS crossover.",0506282v1
2005-06-20,A phenomenological model of the Resonance peak in High Tc Superconductors,"A notable aspect of high-temperature superconductivity in the copper oxides
is the unconventional nature of the underlying paired-electron states. The
appearance of a resonance peak, observed in inelastic neutron spectroscopy in
the superconducting state of the High Tc cuprates, its apparent linear
correlation with the critical superconducting temperature of each of the
compounds and its disappearance in the normal state are rather intriguing. It
may well be that this peak is the signature of the singlet to triplet
excitation, and is an unique characteristic of a d-wave superconductor. We
develop a simple criterion for the resonance peak which is based on the concept
of twist sti ness and its disappearance at T=Tc.",0506490v1
2005-06-29,Quantum lattice solitons in ultracold bosons near Feshbach resonance,"Quantum lattice solitons in a system of two ultracold bosons near Feshbach
resonance are investigated. It is shown that their binding energy, effective
mass, and spatial width, can be manipulated varying the detuning from the
Feshbach resonance. In the case of attractive atomic interactions, the molecule
creation stabilizes the solitons. In the case of repulsive interactions, the
molecule creation leads to the possibility of existence of bright solitons in
some interval of detunings. Due to quantum fluctuations the soliton width is a
random quantity. Its standard deviation is larger than the mean value for such
a small number of particles.",0506766v2
2005-07-15,Antiferro-quadrupole resonance in CeB6,"We report experimental observation of a new type of magnetic resonance caused
by orbital ordering in a strongly correlated electronic system. Cavity
measurements performed on CeB6 single crystals in a frequency range 60-100 GHz
show that a crossing of the phase boundary TQ(B) between the
antiferro-quadrupole and paramagnetic phases gives rise to development at T
<TQ(B) of a magnetic resonance. The observed mode is gapless and correspond to
g-factor 1.62.",0507363v1
2005-07-26,Resonant intrinsic spin Hall effect in p-type GaAs quantum well structure,"We study intrinsic spin Hall effect in p-type GaAs quantum well structure
described by Luttinger Hamiltonian and a Rashba spin-orbit coupling arising
from the structural inversion symmetry breaking. The Rashba term induces an
energy level crossing in the lowest heavy hole subband, which gives rise to a
resonant spin Hall conductance. The resonance may be used to identify the
intrinsic spin Hall effect in experiments.",0507603v1
2005-08-01,Shape resonances in the superconducting order parameter of ultrathin nanowires,"We study the shape resonance effect associated with the confined transverse
superconducting modes of a cylindrical nanowire in the clean limit. Results of
numerical investigations of the Bogoliubov-de Gennes equations show significant
deviations of the energy gap parameter from its bulk value with a profound
effect on the transition temperature. The most striking is that the size of the
resonances is found to be by about order of magnitude larger than in ultrathin
metallic films with the same width.",0508062v1
2005-08-04,Pseudopotential in resonant regimes,"The zero-range potential approach is extended for the description of
situations where two-body scattering is resonant in arbitrary partial waves.
The formalism generalizes the Fermi pseudopotential which can be used only for
s-wave broad resonances. In a given channel, the interaction is described
either in terms of a contact condition on the wave function or with a family of
pseudopotentials. We show that it is necessary to introduce a regularized
scalar product for wave functions obtained in the zero-range potential
formalism (except for the Fermi pseudopotential). This metrics shows that the
geometry of these Hilbert spaces depends crucially on the interaction.",0508120v3
2005-08-25,Evidence of polariton induced transparency in a single organic quantum wire,"The resonant interaction between quasi-one dimensional excitons and photons
is investigated. For a single isolated organic quantum wire, embedded in its
single crystal monomer matrix, the strong exciton-photon coupling regime is
reached. This is evidenced by the suppression of the resonant excitonic
absorption arising when the system eigenstate is a polariton. These
observations demonstrate that the resonant excitonic absorption in a
semiconductor can be understood in terms of a balance between the exciton
coherence time and the Rabi period between exciton-like and photon-like states
of the polariton.",0508602v1
2005-09-02,Spin-dependent resonant tunneling in ZnSe/ZnMnSe heterostructures,"Using the transfer matrix method and the effective-mass approximation, the
effect of resonant states on spin transport is studied in
ZnSe/ZnMnSe/ZnSe/ZnMnSe/ZnSe structures under the influence of both electric
and magnetic fields. The numerical results show that the ZnMnSe layers, which
act as spin filters, polarize the electric currents. Variation of thickness of
the central ZnSe layer shifts the resonant levels and exhibits an oscillatory
behavior in spin current densities. It is also shown that the spin polarization
of the tunneling current in geometrical asymmetry of the heterostructure where
two ZnMnSe layers have different Mn concentrations, depends strongly on the
thickness and the applied bias.",0509067v1
2005-09-08,Resonance width distribution for high-dimensional random media,"We study the distribution of resonance widths P(G) for three-dimensional (3D)
random scattering media and analyze how it changes as a function of the
randomness strength. We are able to identify in P(G) the system-inherent
fingerprints of the metallic, localized, and critical regimes. Based on the
properties of resonance widths, we also suggest a new criterion for determining
and analyzing the metal-insulator transition. Our theoretical predictions are
verified numerically for the prototypical 3D tight-binding Anderson model.",0509195v1
2005-09-12,Backward-wave regime and negative refraction in chiral composites,"Possibilities to realize a negative refraction in chiral composites in in
dual-phase mixtures of chiral and dipole particles is studied. It is shown that
because of strong resonant interaction between chiral particles (helixes) and
dipoles, there is a stop band in the frequency area where the backward-wave
regime is expected. The negative refraction can occur near the resonant
frequency of chiral particles. Resonant chiral composites may offer a root to
realization of negative-refraction effect and superlenses in the optical
region.",0509287v1
2005-09-28,X-Ray Scattering at Lanthanide M5 Resonances: Application to Magnetic Depth Profiling,"Quantitative analyses of x-ray scattering from thin films of Ho and Dy metal
at the M_5 resonances result in values of the optical constants and the
magnetic scattering lengths f_m, with f_m as large as 200 r_0. The observation
of first- and second-order magnetic satellites allows to separate f_m into
circular and linear dichroic contributions. This high magnetic sensitivity, in
conjunction with the tunable x-ray probing depth across the resonance can be
applied to monitor depth profiles of complex magnetic structures, as e.g. of
helical antiferromagnetic domains in a Dy metal film.",0509725v1
2005-09-28,Advanced control with a Cooper-pair box: stimulated Raman adiabatic passage and Fock-state generation in a nanomechanical resonator,"The rapid experimental progress in the field of superconducting nanocircuits
gives rise to an increasing quest for advanced quantum-control techniques for
these macroscopically coherent systems. Here we demonstrate theoretically that
stimulated Raman adiabatic passage (STIRAP) should be possible with the
quantronium setup of a Cooper-pair box. The scheme appears to be robust against
decoherence and should be realizable even with the existing technology. As an
application we present a method to generate single-phonon states of a
nanomechnical resonator by vacuum-stimulated adiabatic passage with the
superconducting nanocircuit coupled to the resonator.",0509735v1
2005-10-25,Resonant proximity effect in normal metal / diffusive ferromagnet / superconductor junctions,"Resonant proximity effect in the normal metal / insulator / diffusive
ferromagnet / insulator / $s$- and d-wave superconductor (N/I/DF/I/S) junctions
is studied for various regimes by solving the Usadel equation with the
generalized boundary conditions. It is shown that the resonant proximity effect
originating from the exchange field in DF layer strongly modifies the tunneling
conductance and density of states.",0510665v1
2005-11-14,Emission characteristics of quantum dots in planar microcavities,"The emission properties of single quantum dots in planar microcavities are
studied experimentally and theoretically. Fivefold Enhanced spontaneous
emission outside the microcavity is found for dots in resonance with the cavity
mode, relative to detuned dots, while their radiative lifetime is only
marginally decreased. Using high power excitation we obtain the in-plane cavity
dispersion. Near field images of the emission show spatial distributions of
several microns for resonant dots, which decrease in size with the detuning
from resonance. These experimental findings are explained using a simple and
intuitive model.",0511350v1
2005-12-28,Resonant effects in the strongly driven phase-biased Cooper-pair box,"We study the time-averaged upper level occupation probability in a strongly
driven two level system, particularly its dependence on the driving amplitude,
frequency and the energy level separation. In contrast to the case of weak
driving, when the positions of the resonances almost do not depend on the
driving amplitude, in the case of the strong diving their positions are
strongly amplitude-dependent. We study these resonances in the concrete system
-- the strongly driven phase-biased Cooper-pair box, which is considered to be
weakly coupled to the tank circuit.",0512682v1
2005-12-29,Friction in nanoelectromechanical systems: Clamping loss in the GHz regime,"The performance of a wide variety of ultra-sensitive devices employing
nanoelectromechanical resonators is determined by their mechanical quality
factor, yet energy dissipation in these systems remains poorly understood. Here
we develop a comprehensive theory of friction in high frequency resonators
caused by the radiation of elastic energy into the support substrate, referred
to as clamping loss. The elastic radiation rate is found to be a strong
increasing function of resonator frequency, and we argue that this mechanism
will play an important role in future microwave-frequency devices.",0512710v1
2005-12-31,Trapped Fermions across a Feshbach resonance with population imbalance,"We investigate the phase separation of resonantly interacting fermions in a
trap with imbalanced spin populations, both at zero and at finite temperatures.
We directly minimize the thermodynamical potential under the local density
approximation instead of using the gap equation, as the latter may give
unstable solutions. On the BEC side of the resonance, one may cross three
different phases from the trap center to the edge; while on the BCS side or at
resonance, typically only two phases show up. We compare our results with the
recent experiment, and the agreement is remarkable.",0601006v2
2006-01-16,Nature of the intensification of a cyclotron resonance in potassium in a normal magnetic field,"The cyclotron-resonance peak which has been observed [G. A. Baraff et al.,
Phys. Rev. Lett. 22, 590 (1969) ] in potassium in a magnetic field directed
perpendicular to the surface may be due to an effect of zero-curvature points
of the Fermi surface on the cyclotron orbit of effective electrons.",0601354v1
2006-02-04,Spin-transfer-driven ferromagnetic resonance of individual nanomagnets,"We demonstrate a technique that enables ferromagnetic resonance (FMR)
measurements of the normal modes for magnetic excitations in individual
nanoscale ferromagnets, smaller in volume by a factor of 1000 than can be
probed by other methods. The measured peak shapes indicate two regimes of
response: simple FMR and phase locking. Studies of the resonance frequencies,
amplitudes, and linewidths as a function of microwave power, DC current, and
magnetic field provide detailed new information about the exchange, damping,
and spin-transfer torques that govern the dynamics in magnetic nanostructures.",0602105v1
2006-02-10,Low-frequency vortex dynamic susceptibility and relaxation in mesoscopic ferromagnetic dots,"Vortex dynamics in a restricted geometry is considered for a magnetic system
consisting of ferromagnetic cylindrical dots. To describe the vortex dynamic
susceptibility and relaxation the equation of motion for the vortex center
position is applied. The dependencies of the vortex dynamic susceptibility and
resonance linewidth on geometrical parameters are calculated. A new method of
extracting damping parameter from the vortex low-frequency resonance peaks is
proposed and applied for interpretation of resonance data on FeNi circular
dots.",0602279v1
2006-02-17,Thermal Escape from a Metastable State in Periodically Driven Josephson Junctions,"Resonant activation and noise-enhanced stability were observed in an
underdamped real physical system, i.e., Josephson tunnel junctions. With a weak
sinusoidal driving force applied, the thermal activated escape from a potential
well underwent resonance-like behavior as a function of the driving frequency.
The resonance also crucially depended on the initial condition of the system.
Numerical simulations showed good agreement with the experimental results.",0602401v3
2006-02-23,Quantum escape kinetics over a fluctuating barrier,"The escape rate of a particle over a fluctuating barrier in a double well
potential exhibits resonance at an optimum value of correlation time of
fluctuation. This has been shown to be important in several variants of kinetic
model of chemical reactions . We extend the analysis of this phenomenon of
resonant activation to quantum domain to show how quantization significantly
enhances resonant activation at low temperature due to tunneling.",0602553v1
2006-02-27,Bifurcations in Resonance Widths of an Open Bose-Hubbard Dimer,"We investigate the structure of resonance widths of a Bose-Hubbard Dimer with
intersite hopping amplitude $k$, which is coupled to continuum at one of the
sites with strength $\gamma$. Using an effective non-Hermitian Hamiltonian
formalism, we show that by varying the on-site interaction term $\chi$ the
resonances undergo consequent bifurcations. For $\Lambda=k/\gamma\geq 0.5$, the
bifurcation points follow a scaling law ${\tilde \chi}_n \equiv \chi_n N/k =
f_{\Lambda}(n-0.5/\Lambda)$, where $N$ is the number of bosons. For the
function $f_{\Lambda}$ two different $\Lambda$ dependences are found around the
minimum and the maximum bifurcation point.",0602626v2
2006-03-31,Diffraction from Ordered States of Higher Multipoles,"Possible ways of identification are discussed of an electronic order of
higher multipoles such as octupoles and hexadecapoles. A particularly powerful
method is resonant X-ray scattering (RXS) using quadrupolar resonance processes
called E2.The characteristic azimuthal angle dependence of
Ce$_{0.7}$La$_{0.3}$B$_6$ is interpreted as evidence of antiferro-octupole
order. For PrRu$_4$P$_{12}$, eightfold pattern against azimuthal angle is
predicted if its metal-insulator transition is a consequence of a hexadecapole
order. In non-resonant superlattice Bragg scattering, hexadecapole contribution
may also be identified because of absence of quadrupole component.",0603837v1
2006-04-06,BEC-BCS crossover in an optical lattice,"We present the microscopic theory for the BEC-BCS crossover of an atomic
Fermi gas in an optical lattice, showing that the Feshbach resonance underlying
the crossover in principle induces strong multiband effects. Nevertheless, the
BEC-BCS crossover itself can be described by a single-band model since it
occurs at magnetic fields that are relatively far away from the Feshbach
resonance. A criterion is proposed for the latter, which is obeyed by most
known Feshbach resonances in ultracold atomic gases.",0604186v2
2006-04-21,Exciton mediated one phonon resonant Raman scattering from one-dimensional systems,"We use the Kramers-Heisenberg approach to derive a general expression for the
resonant Raman scattering cross section from a one-dimensional (1D) system
explicitly accounting for excitonic effects. The result should prove useful for
analyzing the Raman resonance excitation profile lineshapes for a variety of 1D
systems including carbon nanotubes and semiconductor quantum wires. We apply
this formalism to a simple 1D model system to illustrate the similarities and
differences between the free electron and correlated electron-hole theories.",0604515v1
2006-04-26,Time-domain measurement of driven ferromagnetic resonance,"We present a time-resolved measurement of magnetization dynamics during
ferromagnetic resonance (FMR) in a single layer of Ni81Fe19. Small-angle (<1
deg.) precession of elemental Ni, Fe moments could be measured directly and
quantitatively using time-resolved x-ray magnetic circular dichroism (XMCD) in
transmission. The high temporal and rotational sensitivity of of this technique
has allowed characterization of the phase and amplitude of driven FMR motion at
2.3 GHz, verifying basic expectations for a driven resonance.",0604610v1
2006-05-01,Resonances in one-dimensional Disordered Chain,"We study the average density of resonances, $<\rho(x,y)>$, in a semi-infinite
disordered chain coupled to a perfect lead. The function $<\rho(x,y)>$ is
defined in the complex energy plane and the distance $y$ from the real axes
determines the resonance width. We concentrate on strong disorder and derive
the asymptotic behavior of $<\rho(x,y)>$ in the limit of small $y$.",0605030v2
2006-05-27,Delayed Random Walks and Control,"Issues of resonance that appear in non-standard random walk models are
discussed. The first walk is called repulsive delayed random walk, which is
described in the context of a stick balancing experiment. It will be shown that
a type of ""resonant"" effect takes place to keep the stability of the fixed
point better with tuned bias and delay. We also briefly discuss the second
model called sticky random walk, which is introduced to model string
entanglement. Peculiar resonant effects with respect to these random walks are
presented.",0605682v1
2006-06-20,Resonant Tunneling Magneto Resistance in Coupled Quantum Wells,"A three barrier resonant tunneling structure in which the two quantum wells
are formed by a dilute magnetic semiconductor material (ZnMnSe) with a giant
Zeeman splitting of the conduction band is theoretically investigated.
Self-consistent numerical simulations of the structure predict giant
magnetocurrent in the resonant bias regime as well as significant current spin
polarization for a considerable range of applied biases.",0606531v2
2006-06-25,Inductive Detection of Magnetostrictive Resonance,"We have developed an inductive method to detect the magnetostrictive
resonance signal and applied it to an ultrasonic magnetostrictive transducer
sample. Slab shaped ferrite samples are mounted in an RF coil and actuated by
pulse modulated RF magnetic field. A DC magnetic field is also applied and the
resonance signal from the sample is detected by the same coil after the RF
field is turned off. The detector system is similar to a conventional pulse NMR
system with quadrature detection. The detected signal is sensitive to the bias
DC field strength and direction as well as the dimension of the sample.",0606636v1
2006-06-29,Control of the interaction in a Fermi-Bose mixture,"We control the interspecies interaction in a two-species atomic quantum
mixture by tuning the magnetic field at a Feshbach resonance. The mixture is
composed by fermionic 40K and bosonic 87Rb. We observe effects of the large
attractive and repulsive interaction energy across the resonance, such as
collapse or a reduced spatial overlap of the mixture, and we accurately locate
the resonance position and width. Understanding and controlling instabilities
in this mixture opens the way to a variety of applications, including formation
of heteronuclear molecular quantum gases.",0606757v2
2006-07-03,On-chip detection of ferromagnetic resonance of a single submicron permalloy strip,"We measured ferromagnetic resonance of a single submicron ferromagnetic
strip, embedded in an on-chip microwave transmission line device. The method
used is based on detection of the oscillating magnetic flux due to the
magnetization dynamics, with an inductive pick-up loop. The dependence of the
resonance frequency on applied static magnetic field agrees very well with the
Kittel formula, demonstrating that the uniform magnetization precession mode is
being driven.",0607036v1
2006-07-11,Extreme Nonlinear Phenomena in NbN Superconducting Stripline Resonators,"We study a microwave superconducting stripline resonator made of NbN on a
Sapphire wafer. Novel, self-sustained modulation of the reflected power off the
resonator, at frequencies of up to 60MHz, has been recently reported. Here we
show experimentally that near the self modulation threshold, the device
exhibits a giant nonlinearity, which manifests itself in an extremely high
intermodulation gain, accompanied by a very strong noise squeezing and period
doubling of various orders. Such a device is highly suitable for serving as a
readout device in quantum data processing systems.",0607262v1
2006-07-19,States of fermionic atoms in an optical superlattice across a Feshbach resonance,"We investigate states of fermionic atoms across a broad Feshbach resonance in
an optical superlattice which allows interaction only among a small number of
lattice sites. The states are in general described by superpositions of atomic
resonating valence bonds and dressed molecules. As one scans the magnetic
field, level crossing is found between states with different symmetry
properties, which may correspond to a quantum phase transition in the many-body
case.",0607464v1
2006-07-23,Ultracold heteronuclear molecules in a 3D optical lattice,"We report on the creation of ultracold heteronuclear molecules assembled from
fermionic 40K and bosonic 87Rb atoms in a 3D optical lattice. Molecules are
produced at a heteronuclear Feshbach resonance both on the attractive and the
repulsive side of the resonance. We precisely determine the binding energy of
the heteronuclear molecules from rf spectroscopy across the Feshbach resonance.
We characterize the lifetime of the molecular sample as a function of magnetic
field and measure between 20 and 120ms. The efficiency of molecule creation via
rf association is measured and is found to decrease as expected for more deeply
bound molecules.",0607581v1
2006-08-01,Coherent magnetotransport spectroscopy in an edge-blocked double quantum wire with window and resonator coupling,"We propose an electronic double quantum wire system that contains a pair of
edge blocking potential and a coupling element in the middle barrier between
two ballistic quantum wires. A window and a resonator coupling control between
the parallel wires are discussed and compared for the enhancement of the
interwire transfer processes in an appropriate magnetic field. We illustrate
the results of the analysis by performing computational simulations on the
conductance and probability density of electron waves in the window and
resonator coupled double wire system.",0608027v1
2006-08-10,Surface Plasmon Assisted Kondo Resonances on a Metallic Nanowire,"In this letter we propose an experiment to measure the Kondo effect for
magnetic atoms adsorbed on the surface of a metallic nanowire. In addition to
the traditional sp-d hybridization, by introducing the strong electromagnetic
field of the localized surface plasmon on the nanowire, we show that it is
possible to observe additional sp-d electron transfer processes assisted by
surface plasmons. Due to the good surface-to-volume ratio of the nanowire, the
Kondo resonances here would be revealed as multiple anti-resonances in the
differential conductance versus bias voltage curve.",0608239v1
2006-08-10,Fractional charge revealed in computer simulations of resonant tunneling in the fractional quantum Hall regime,"The concept of fractional charge is central to the theory of the fractional
quantum Hall effect (FQHE). Here I use exact diagonalization as well as
configuration space renormalization (CSR) to study finite clusters which are
large enough to contain two independent edges. I analyze the conditions of
resonant tunneling between the two edges. The ""computer experiment"" reveals a
periodic sequence of resonant tunneling events consistent with the
experimentally observed fractional quantization of electric charge in units of
e/3 and e/5.",0608252v1
2006-08-17,Steps and dips in the ac conductance and noise of mesoscopic structures,"The frequency dependence of the equilibrium ac conductance (or the noise
power spectrum) through a mesoscopic structure is shown to exhibit steps and
dips. The steps, at energies related to the resonances of the structure, are
closely related to the partial Friedel phases of these resonances, thus
allowing a direct measurement of these phases (without interferometry). The
dips in the spectrum are related to a destructive interference in the
absorption of energy by transitions between these resonances, in some
similarity with the Fano effect.",0608406v1
2006-09-06,Control of electron transport through Fano resonances in molecular wires,"Using a first principles approach, we study the electron transport properties
of two molecules of length 2.5nm which are the building blocks for a new class
of molecular wires containing fluorenone units. We show that the presence of
side groups attached to these units leads to Fano resonances close to the Fermi
energy. As a consequence electron transport through the molecule can be
controlled either by chemically modifying the side group, or by changing the
conformation of the side group. This sensitivity, which is not present in
Breit-Wigner resonances, opens up new possibilities for novel single-molecule
sensors.",0609109v1
2006-09-08,Large cone angle magnetization precession of an individual nanomagnet with dc electrical detection,"We demonstrate on-chip resonant driving of large cone-angle magnetization
precession of an individual nanoscale permalloy element. Strong driving is
realized by locating the element in close proximity to the shorted end of a
coplanar strip waveguide, which generates a microwave magnetic field. We used a
microwave frequency modulation method to accurately measure resonant changes of
the dc anisotropic magnetoresistance. Precession cone angles up to $9^{0}$ are
determined with better than one degree of resolution. The resonance peak shape
is well-described by the Landau-Lifshitz-Gilbert equation.",0609190v1
2006-09-19,The emergence of Resonating Valence Bond physics in spin-orbital models,"We discuss how orbital degeneracy, which is usually removed by a cooperative
Jahn-Teller distortion, could under appropriate circumstances lead rather to a
Resonating Valence Bond spin-orbital liquid. The key points are: i) The
tendency to form spin-orbital dimers, a tendency already identified in several
cases; ii) The mapping onto Quantum Dimer Models, which have been shown to
possess Resonating Valence Bond phases on the triangular lattice. How this
program can be implemented is explained in some details starting from a
microscopic model of LiNiO$_2$.",0609455v1
2006-11-02,Photoinduced Fano-resonance of coherent phonons in zinc,"Utilizing femtosecond optical pump-probe technique, we have studied transient
Fano-resonance in zinc. At high excitation levels the Fourier spectrum of the
coherent E$_{2g}$ phonon exhibits strongly asymmetric line shape, which is well
modeled by the Fano function. The Fano parameter (1/Q) was found to be strongly
excitation fluence dependent while depending weakly on the initial lattice
temperature. We attribute the origin of the Fano-resonance to the coupling of
coherent phonon to the electronic continuum, with their transition
probabilities strongly renormalized in the vicinity of the photoinduced
structural transition.",0611042v1
2006-11-09,SiOx/Si radial superlattices and microtube optical ring resonators,"Scanning and transmission electron microscopy reveal that SiOx/Si layers can
roll-up into microtubes and radial superlattices on a Si substrate. These
hybrid objects are thermally stable up to 850 C and emit light in the visible
spectral range at room temperature. For tubes disengaged from the substrate
surface, optically resonant emission with mode spacings inversely proportional
to the tube diameter are observed and agree excellently with those obtained
from Finite-Different-Time-Domain simulations. The resonant modes we record are
strictly polarized along the tube axis.",0611261v1
2006-11-22,Trapped Resonant Fermions above Superfluid Transition Temperature,"We investigate trapped resonant fermions with unequal populations within the
local density approximation above the superfluid transition temperature. By
tuning the attractive interaction between fermions via Feshbach resonance, the
system evolves from weakly interacting fermi gas to strongly interacting fermi
gas, and finally becomes bose-fermi mixture. The density profiles of fermions
are examined and compared with experiments. We also point out the simple
relationships between the local density, the axial density, and the gas
pressure within the local density approximation.",0611578v2
2006-12-22,Nonlinear resonance in a three-terminal carbon nanotube resonator,"The RF-response of a three-terminal carbon nanotube resonator coupled to
RF-transmission lines is studied by means of perturbation theory and direct
numerical integration. We find three distinct oscillatory regimes, including
one regime capable of exhibiting very large hysteresis loops in the frequency
response. Considering a purely capacitive transduction, we derive a set of
algebraic equations which can be used to find the output power (S-parameters)
for a device connected to transmission lines with characteristic impedance
$Z_0$.",0612589v1
2007-01-14,Work Fluctuations and Stochastic Resonance,"We study Brownian particle motion in a double-well potential driven by an ac
force. This system exhibits the phenomenon of stochastic resonance.
Distribution of work done on the system over a drive period in the time
asymptotic regime have been calculated. We show that fluctuations in the input
energy or work done dominate the mean value. The mean value of work done over a
period as a function of noise strength can also be used to characterise
stochastic resonance in the system. We also discuss the validity of steady
state fluctuation theorems in this particular system.",0701303v1
2007-01-15,Non-local effective medium of metamaterial,"In this paper, we investigate the effect of spatial dispersion on a
double-lattice metamaterial which has both magnetic and electric response. A
numerical scheme based on a dipolar model is developed to extract the non-local
effective medium of the metamaterial. We found a structure-induced bianisotropy
near the resonance gap even if the artificial particles are free from
cross-coupling. A cross-coupled resonance also results from spatial dispersion
and it can be understood using a Lorentz frequency dispersion model. The
strength of the cross-coupled resonance depends on the microstructure and it is
larger at a higher normalized frequency.",0701332v1
2007-02-12,Fermi-Bose mixture with tunable interactions,"We give an overview of recent experiments on an ultracold Fermi-Bose quantum
gas where the interspecies interaction can be tuned via magnetic Feshbach
resonances. We first describe the various steps that have led to the
observation of Feshbach resonances in the K-Rb system we investigate, and their
accurate characterization. We then describe experiments in which Feshbach
resonances are exploited to study interaction effects and to associate weakly
bound KRb dimers.",0702277v1
2007-02-26,Switchable coupling for superconducting qubits using double resonance in the presence of crosstalk,"Several methods have been proposed recently to achieve switchable coupling
between superconducting qubits. We discuss some of the main considerations
regarding the feasibility of implementing one of those proposals: the
double-resonance method. We analyze mainly issues related to the achievable
effective coupling strength and the effects of crosstalk on this coupling
approach. We also find a new, crosstalk-assisted coupling channel that can be
an attractive alternative when implementing the double-resonance coupling
proposal.",0702603v3
2007-03-03,p-wave Feshbach molecules,"We have produced and detected molecules using a p-wave Feshbach resonance
between 40K atoms. We have measured the binding energy and lifetime for these
molecules and we find that the binding energy scales approximately linearly
with magnetic field near the resonance. The lifetime of bound p-wave molecules
is measured to be 1.0 +/- 0.1 ms and 2.3 +/- 0.2 ms for the m_l = +/- 1 and m_l
= 0 angular momentum projections, respectively. At magnetic fields above the
resonance, we detect quasi-bound molecules whose lifetime is set by the
tunneling rate through the centrifugal barrier.",0703087v2
2007-03-21,Exact low temperature results for transport properties of the interacting resonant level model,"Using conformal field theory and integrability ideas, we give a full
characterization of the low temperature regime of the anisotropic interacting
resonant level (IRLM) model. We determine the low temperature corrections to
the linear conductance exactly up to the 6th order. We show that the structure
displays 'Coulomb deblocking' at resonance, i.e., a strong impurity-wire
capacitive coupling enhances the conductance at low temperature.",0703545v1
1997-09-10,Exponential Bounds on Curvature-Induced Resonances in a Two-Dimensional Dirichlet Tube,"We consider curvature-induced resonances in a planar two-dimensional
Dirichlet tube of a width $ d $. It is shown that the distances of the
corresponding resonance poles from the real axis are exponentially small as $
d\to 0+ $, provided the curvature of the strip axis satisfies certain
analyticity and decay requirements.",9709001v1
1998-01-05,Noisy Spherical Resonant Detector of Gravitational Waves: Veto on the Longitudinal Part of the Signal,"The equations of a resonant sphere in interaction with $N$ secondary radial
oscillators (transducers) on its surface have been found in the context of
Lagrangian formalism. It has been shown the possibility to exert a veto against
spurious events measuring the longitudinal component of a signal. Numerical
simulations has been performed, which take into account thermal noise between
resonators and the sphere surface, for a particular configuration of the
transducers.",9801006v1
1999-11-15,Resonant Spheres: Multifrequency Detectors of Gravitational Waves,"We discuss the capabilities of spherical antenn\ae as single multifrequency
detectors of gravitational waves. A first order theory allows us to evaluate
the coupled spectrum and the resonators readouts when the first and the second
quadrupole bare sphere frequencies are simultaneously selected for layout
tuning. We stress the existence of non-tuning influences in the second mode
coupling causing draggs in the frequency splittings. These URF effects are
relevant to a correct physical description of resonant spheres, still more if
operating as multifrequency appliances like our PHCA proposal.",9911056v1
2000-12-01,Resonance enhancement of particle production during reheating,"We found a consistent equation of reheating after inflation, which shows that
for small quantum fluctuations the frequencies of resonance are slighted
different from the standard ones. Quantum interference is taken into account
and we found that at large fluctuations the process mimics very well the usual
parametric resonance but proceed in a different dynamical way. The analysis is
made in a toy quantum mechanical model and we discuss further its extension to
quantum field theory.",0012005v2
2002-02-06,"Holonomy invariance, orbital resonances, and kilohertz QPOs","Quantized orbital structures are typical for many aspects of classical
gravity (Newton's as well as Einstein's). The astronomical phenomenon of
orbital resonances is a well-known example. Recently, Rothman, Ellis and
Murugan (2001) discussed quantized orbital structures in the novel context of a
holonomy invariance of parallel transport in Schwarzschild geometry. We present
here yet another example of quantization of orbits, reflecting both orbital
resonances and holonomy invariance. This strong-gravity effect may already have
been directly observed as the puzzling kilohertz quasi-periodic oscillations
(QPOs) in the X-ray emission from a few accreting galactic black holes and
several neutron stars.",0202020v1
2002-09-10,"Acceleration and Cyclotron Radiation, Induced by Gravitational Waves","The equations which determine the response of a charged particle moving in a
magnetic field to an incident gravitational wave(GW) are derived in the
linearized approximation to general relativity. We briefly discuss several
astrophysical applications of the derived formulae taking into account the
resonance between the wave and the particle's motion which occurs at
$\omega_g=2\Omega$, whenever the GW is parallel to the constant magnetic field.
In the case where the GW is perpendicular to the constant magnetic field,
magnetic resonances appear at $\omega_g=\Omega$ and $\omega_g=2\Omega$. Such
resonant mechanism may be useful to build models of GW driven cyclotron
emitters.",0209033v1
2003-12-23,Gravitational waves interacting with a spinning charged particle in the presence of a uniform magnetic field,"The equations which determine the response of a spinning charged particle
moving in a uniform magnetic field to an incident gravitational wave are
derived in the linearized approximation to general relativity. We verify that
1) the components of the 4-momentum, 4-velocity and the components of the
spinning tensor, both electric and magnetic moments, exhibit resonances and 2)
the co-existence of the uniform magnetic field and the GW are responsible for
the resonances appearing in our equations. In the absence of the GW, the
magnetic field and the components of the spin tensor decouple and the magnetic
resonances disappear.",0312102v1
2005-04-22,Test of constancy of speed of light with rotating cryogenic optical resonators,"A test of Lorentz invariance for electromagnetic waves was performed by
comparing the resonance frequencies of two optical resonators as a function of
orientation in space. In terms of the Robertson-Mansouri-Sexl theory, we obtain
$\beta-\delta-1/2=(+0.5\pm 3\pm 0.7) E-10$, a ten-fold improvement compared to
the previous best results. We also set a first upper limit for a so far unknown
parameter of the Standard Model Extension test theory,
$|(\tilde{\kappa}_{e-})^{ZZ}| < 2\cdot E-14$.",0504109v1
2005-06-08,Resonant growth of stellar oscillations by incident gravitational waves,"Stellar oscillation under the combined influences of incident gravitational
wave and radiation loss is studied in a simple toy model. The star is
approximated as a uniform density ellipsoid in the Newtonian gravity including
radiation damping through quadrupole formula. The time evolution of the
oscillation is significantly controlled by the incident wave amplitude $h$,
frequency $\nu$ and damping time $\tau$. If a combination $ h \nu \tau $
exceeds a threshold value, which depends on the resonance mode, the resonant
growth is realized.",0506047v1
2007-01-15,Detectability of Mode Resonances in Coalescing Neutron Star Binaries,"Inspirals of neutron star-neutron star binaries are a promising source of
gravitational waves for gravitational wave detectors like LIGO. During the
inspiral, the tidal gravitational field of one of the stars can resonantly
excite internal modes of the other star, resulting in a phase shift in the
gravitational wave signal. We compute using a Fisher-matrix analysis how large
the phase shift must be in order to be detectable. For a $1.4 M_\odot, 1.4
M_\odot$ binary the result is $\sim 8.1, 2.9$ and 1.8 radians, for resonant
frequencies of $16, 32$ and 64 Hz. The measurement accuracies of the other
binary parameters are degraded by inclusion of the mode resonance effect.",0701076v1
2001-11-26,Hadronic Decays of Charm,"Recent hadronic charm decay results from fixed-target experiments are
presented. New measurements of the D0 to K-K+K-pi+ branching ratio are shown as
are recent results from Dalitz plot fits to D+ to K-K+pi+, pi+pi-pi+, K-pi+pi+,
K+pi-pi+ and D_s+ to pi+pi-pi+, K+pi-pi+. These fits include measurements of
the masses and widths of several light resonances as well as strong evidence
for the existence of two light scalar particles, the pipi resonance sigma and
the Kpi resonance kappa.",0111083v1
2002-10-10,N* and Meson Resonances in J/psi decays,"Over sixty million J/psi events have been collected by the BES Collaboration
at the Beijing Electron-Positron Collider (BEPC). J/psi decays provide an
excellent place for studying excited nucleons and hyperons -- N*, $\Lambda^*$,
$\Sigma^*$ and $\Xi^*$ resonances, as well as meson resonances, including
possible glueballs and hybrids. Physics objectives, recent results and future
prospects of light hadron spectroscopy at BEPC are presented.",0210028v1
2002-12-21,Evidence for Light Scalar Resonances in Charm Meson Decays from Fermilab E791,"From Dalitz-plot analyses of $D^+\to\pi^-\pi^+\pi^+$ and $D^+\to
K^-\pi^+\pi^+$ decays, we find evidence for light and broad scalar resonances
sigma(500) and kappa(800). From a Dalitz-plot analysis of
$D^+_s\to\pi^-\pi^+\pi^+$ decays, we measure the masses and decay widths of the
scalar resonances f_0(980) and f_0(1370).",0212057v3
2003-06-24,A Dalitz Plot Analysis of D0 -> pi+ pi- pi0 Decays in CLEO II.V,"Using the 9 inverse femtobarn data sample collected with the CLEO II.V
detector at the Cornell Electron Storage Ring, we have studied the resonant
substructure of the Cabibbo suppressed decay D0 -> pi+ pi- pi0. We observe
significant contributions from the rho- pi+, rho+ pi-, rho0 pi0, and
non-resonant channels, and present preliminary results of the amplitudes,
phases, and fit fractions for these sub-modes. No evidence for the sigma(500)
or more massive rho resonances was found. We observe no CP violation, finding
Acp = 0.01 +0.09 -0.07 +- 0.09.",0306048v1
2003-08-08,"A Measurement of the Total Width, the Electronic Width and the Mass of the Upsilon(10580) Resonance","We present a preliminary measurement of the resonance parameters of the
Upsilon(10580) resonance with the BABAR detector at the SLAC PEP-II asymmetric
B factory. We measure the total decay width to be (20.7 +- 1.6 +- 2.5) MeV, the
partial electronic width to be (0.321 +- 0.017 +- 0.029) kev and the mass to be
(10.5793 +- 0.0004 +- 0.0012) GeV.",0308020v1
2004-03-11,Evidence for a Narrow Anti-Charmed Baryon State,"A narrow resonance in D*- p and D*+ pbar invariant mass combinations is
observed in inelastic electron-proton collisions at centre-of-mass energies of
300 GeV and 320 GeV at HERA. The resonance has a mass of 3099 \pm 3 (stat.) \pm
5 (syst.) MeV and a measured Gaussian width of 12 \pm 3 (stat.) MeV, compatible
with the experimental resolution. The resonance is interpreted as an
anti-charmed baryon with a minimal constituent quark composition of uuddcbar,
together with the charge conjugate.",0403017v1
2004-05-17,Search for the exotic $Ξ^{--}(1860)$ Resonance in 340GeV/c $Σ^-$-Nucleus Interactions,"We report on a high statistics search for the $\Xi^{--}(1860)$ resonance in
$\Sigma^-$-nucleus collisions at 340GeV/c. No evidence for this resonance is
found in our data sample which contains 676000 $\Xi^-$ candidates above
background. For the decay channel $\Xi^{--}(1860) \to \Xi^-\pi^-$ and the
kinematic range 0.15$<x_F<$0.9 we find a 3$\sigma$ upper limit for the
production cross section of 3.1 and 3.5 $\mu$b per nucleon for reactions with
carbon and copper, respectively.",0405042v2
2004-12-10,"Search for an exotic S=-2, Q=-2 baryon resonance at a mass near 1862 MeV in quasi-real photoproduction","A search for an exotic baryon resonance with $S=-2, Q=-2$ has been performed
in quasi-real photoproduction on a deuterium target through the decay channel
$\Xi^- \pi^- \to \Lambda \pi^- \pi^- \to p \pi^- \pi^- \pi^-$. No evidence for
a previously reported $\Xi^{--}(1860)$ resonance is found in the $\Xi^-
\pi^-$invariant mass spectrum. An upper limit for the photoproduction cross
section of 2.1 nb is found at the 90% confidence level. The photoproduction
cross section for the $\Xi^{0}(1530)$ is found to be between 9 and 24 nb.",0412027v2
2005-06-06,Photoproduction of Baryons Decaying into N pi and N eta,"A combined analysis of photoproduction data on \gamma p to \pi N, eta N was
performed including the data on K Lambda and K Sigma. The data are interpreted
in an isobar model with s--channel baryon resonances and pi, rho,(omega), K,
and K^* exchange in the t--channel. Three baryon resonances have a substantial
coupling to eta N, the well known N(1535)S_{11}, N(1720)P_{13}, and
N(2070)D_{15}. The inclusion of data with open strangeness reveals the presence
of further new resonances, N(1840)P_{11}, N(1875)D_{13} and N(2170)D_{13}.",0506010v1
2006-04-28,Search for a Narrow Baryonic Resonance Decaying to $K^0_s p$ or $K^0_s \bar{p}$ in Deep Inelastic Scattering at HERA,"A search for a narrow baryonic resonance decaying to $K^0_s p$ or $K^0_s \bar
p$ is carried out in deep inelastic ep scattering with the H1 detector at HERA.
Such a resonance could be a strange pentaquark \thplns, evidence for which has
been reported by several experiments. The $K^0_s p$ and $K^0_s \bar p$
invariant mass distributions presented here do not show any significant peak in
the mass range from threshold up to 1.7 GeV. Mass dependent upper limits on
$\sigma(ep \to e \thplf X)\times BR(\thplf \to K^0 p)$ are obtained at the 95%
confidence level.",0604056v1
1992-04-08,Is there a $ρ$ in the O(4) $λφ^4_4$ theory?,"A Monte Carlo simulation of the O(4) $\lambda \phi^4$ theory in the broken
phase is performed on a hypercubic lattice in search of an I=1, J=1 resonance.
The region of the cutoff theory where the interaction is strong is investigated
since it is there that a resonance would be expected to have a better chance to
form. In that region the presence of an I=1, J=1 resonance with mass below the
cutoff is excluded.",9203001v1
1992-06-03,Resonance Scattering Phase Shifts in a 2-d Lattice Model,"We study a simple 2-d model representing two fields with different mass and a
3-point coupling term. The phase shift in the resonating 2-particle channel is
determined from the energy spectrum obtained in Monte Carlo simulations on
finite lattices. Masses and wave function renormalization constants of the
fields as well as mass and width of the resonance are determined and discussed.
The representation of scattering states in terms of the considered operators is
analysed.",9206004v1
1994-11-29,$τ\to πK ν$ Decay and $πK$ Scattering,"Using chiral low energy theorems and elastic unitarity assumption, the
$\tau\to\pi K \nu $ decay is investigated. The vector and scalar $\pi K$ form
factors are calculated. It is found that the $\pi K$ spectrum is dominated by
the $K^*$ resonance. By measuring the forward-backward asymmetry, it is shown
that the S wave $\pi K$ phase shift can be determined near the $K^{*}$
resonance region. The calculated branching ratio and resonance parameters are
in good agreement with experiments.",9411423v1
1995-03-30,On a subtle point of sum rules calculations: toy model,"We consider a two-point correlator in massless $\phi^3$ model within the
ladder approximation . The spectral density of the correlator is known
explicitly and does not contain any resonances. Meanwhile making use of the
standard sum rules technique with a simple ""resonance + continuum"" model of the
spectrum allows to predict parameters of the ""resonance"" very accurately in the
sense that all necessary criteria of stability are perfectly satisfied.",9503470v1
1995-08-18,Quark Model Explanation of the $N^*\to Nη$ Branching Ratios,"The constituent quark model can explain the strong selectivity of the $N\eta$
decay branching ratios of the nucleon resonances if the fine structure
interaction between the constituent quarks is described in terms of Goldstone
boson exchange. This chiral quark model predicts that the resonances $N(1535)$,
$N(1710)$, $\Lambda(1670)$, $\Sigma(1750)$, which have mixed flavor and spin
symmetry $[21]_{FS} [21]_F [21]_S$ wavefunctions in lowest order, should have
large $N\eta$ branching ratios, while $N\eta$ decay of the other resonances
that have different flavor-spin symmetry should be strongly suppressed in
agreement with the experimental branching ratios.",9508327v1
1996-08-19,"Strong WW Scattering. Chiral Lagrangians, Unitarity and Resonances","Chiral lagrangians provide a model independent description of the strongly
interacting symmetry breaking sector. In this work it is first reviewed the LHC
sensitivity to the chiral parameters (in the hardest case of non-resonant
low-energy WW scattering). Later it is shown how to reproduce or predict the
resonance spectrum by means of dispersion theory and the inverse amplitude
method. We present a parameter space scan that covers many different strong WW
scattering scenarios.",9608371v1
1997-01-24,A study of the effects of preheating,"We review results of a numerical study of resonant inflaton decay in a wide
range of realistic models and parameters. Wide enough parametric resonance can
withstand the expansion of the Universe, though account for the expansion is
very important for determining precisely how wide it should be. For example,
the effective production of particles with mass ten times that of the inflaton
requires very large values of the resonance parameter $q$, $q > 10^8$. For
these large $q$, the maximal size of produced fluctuations is significantly
suppressed by back reaction, $< X^2 > \sim 10^{-10} M_{Pl}^2$. We discuss some
physical implications of our results.",9701376v1
1997-03-18,Majorana Neutrinos and Gravitational Oscillation,"We analyze the possibility of encountering resonant transitions of high
energy Majorana neutrinos produced in Active Galactic Nuclei (AGN). We consider
gravitational, electromagnetic and matter effects and show that the latter are
ignorable. Resonant oscillations due to the gravitational interactions are
shown to occur at energies in the PeV range for magnetic moments in the
$10^{-17} \mu_B$ range. Coherent precession will dominate for larger magnetic
moments. The alllowed regions for gravitational resonant transitions are
obtained.",9703362v1
1997-11-03,Reexamination of the resonance contributions in B->X_s e^+ e^-,"With help of the recent developments in the heavy quarkonium physics, we
reexamine the long distance(LD) effects in \Bsee dominantly from the charmonium
resonances $J/\Psi$ and $\Psi^{\prime}$ through the decay chains $B\ra X_s
J/\Psi (\Psi^{\prime}) \ra X_s e^+ e^-$. We find that the resonance to
nonresonance interference are reduced substantially.",9711209v1
1997-11-21,R-Parity Violation and Sneutrino Resonances at Muon Colliders,"In supersymmetric models with R-parity violating interactions, sneutrinos may
be produced as $s$-channel resonances at $\mu^+ \mu^-$ colliders. We
demonstrate that, for R-parity violating couplings as low as $10^{-4}$,
sneutrinos can be discovered and their couplings measured to high accuracy. The
excellent beam energy resolution of muon colliders is found to be especially
useful for studying such resonances in certain cases.",9711414v1
1997-11-26,Broad resonances as locking states and the problem of confinement,"We discuss the mechanism of broad state formation when one of several
overlapping resonances accumulates the widths of others. This mechanism may be
important in the mixing of quark states with exotic ones. The broad resonance
acts as a locking state for other states which mix with it; we consider the
role of the broad state in the formation of the confinement barrier.",9711478v1
1997-12-04,Higgs Resonance Studies At The First Muon Collider,"Higgs resonance signals and backgrounds at the First Muon Collider are
discussed. Effects due to beam polarization and background angular
distributions (forward-backward charge asymmetries) are examined. The utility
of those features for improving precision measurements and narrow resonance
``discovery'' scans is described.",9712270v1
1998-01-01,Perturbative Duality in the Resonance Spin Structure Functions,"We investigate the relations between the spin structure functions in the
scaling and resonance regions. We examine the possible duality between the two,
and draw inferences for the behavior of the asymmetry A_1 at large x. Finally,
we point out the importance of additional polarized structure function data in
the resonance region in terms of testing the hysteresis of perturbative
physics.",9801205v1
1998-04-10,Evidence for a scalar kappa(900) resonance in pi-K scattering,"Motivated by the $1/N_c$ expansion, we study a simple model in which the pi-K
scattering amplitude is the sum of a current-algebra contact term and resonance
pole exchanges. This phenomenological model is crossing symmetric and, when a
putative light strange scalar meson, kappa, is included, satisfies the
unitarity bounds to well above 1 GeV. The model also features chiral dynamics,
vector meson dominance and appropriate interference between the established
scalar K*(1430) resonance and its predicted background. We briefly discuss the
physical significance of the results and directions for further work.",9804273v1
1998-07-29,Phenomenology of Scalar Mesons,"A separable potential model of three coupled channels (pion-pion,
kaon-antikaon and an effective four pion) has been constructed and applied in
the analysis of the isoscalar S-wave pion-pion and kaon-antikaon phase shifts
and inelasticities .A relatively narrow scalar resonance of mass 1400-1460 MeV
has been found. This resonance is consistent with the recent CERN observation
of an eventual scalar glueball at 1500 MeV. Other resonances at lower energies
like a wide sigma meson and a narrow f0(980) have been confirmed.",9807539v1
1998-08-05,Interpretation of Experimental J^PC Exotic Signals,"We investigate theoretical interpretations of the 1.4 GeV J^PC exotic
resonance reported by the E852 collaboration. It is argued that interpretation
in terms of a hybrid meson is untenable. A K-matrix analysis shows that the 1.4
GeV enhancement in the E852 eta pi data can be understood as an interference of
a non-resonant Deck-type background and a resonance at 1.6 GeV. A final state
rescattering calculation shows that the 1.6 GeV hybrid has a eta pi width which
is bounded above by 57 \pm 14 MeV.",9808225v1
1998-12-31,Gamma photons from parametric resonance in neutron stars,"Shock waves in cold nuclear matter, e.g. those induced by a collision of two
neutron stars, can generate a large number of gamma photons via parametric
resonance. We study the resonant production of gamma rays inside a shocked
neutron star and discuss the possible astrophysical consequences of this
phenomenon.",9812534v2
1999-02-22,Resonances in radiative hyperon decays,"The importance of resonances for the radiative hyperon decays is examined in
the framework of chiral perturbation theory. Low lying baryon resonances are
included into the effective theory and tree contributions to these decays are
calculated. We find significant contributions to both the parity-conserving and
parity-violating decay amplitudes and a large negative value for the asymmetry
parameter in polarized Sigma^+ -> p gamma is found, in agreement with the
experimental result alpha(p Sigma^+) = -0.76 +/- 0.08.",9902431v1
1999-08-04,Resonant Two-body D Decays,"The contribution of a $K^*(1430)$ $0^+$ resonance to $D^0\to K^-\pi^+$ is
calculated by applying the soft pion theorem to $D^+ \to K^* \pi^+$, and is
found to be about 30% of the measured amplitude and to be larger than the
$\Delta I=3/2$ component of this amplitude. We estimate a 70% contribution to
the total amplitude from a higher $K^*(1950)$ resonance. This implies large
deviations from factorization in D decay amplitudes, a lifetime difference
between D^0 and D^+, and an enhancement of $D^0-\bar D^0$ mixing due to SU(3)
breaking.",9908237v2
1999-09-28,Resonances and higher twist in polarized lepton-nucleon scattering,"We present a detailed analysis of resonance contributions in the context of
higher twist effects in the moments of the proton spin structure function g_1.
For each of these moments, it is found that there exists a characteristic Q^2
region in which (perturbative) higher twist corrections coexist with
(non-perturbative) resonance contribution of comparable magnitude.",9909524v1
1999-10-18,Chiral Symmetry Realization for Even- and Odd-parity Baryon Resonances,"Baryon resonances with even and odd parity are collectively investigated from
the viewpoint of chiral symmetry(ChS). We propose a quartet scheme where
Delta's and N^*'s with even and odd parity form a chiral multiplet. This scheme
gives parameter-free constraints on the baryon masses in the quartet, which are
consistent with observed masses with spin 1/2, 3/2, 5/2. The scheme also gives
selection rules in the one-pion decay: The absence of the parity non-changing
decay N(1720) -> pi Delta(1232) is a typical example which should be confirmed
experimentally to unravel the role of ChS in baryon resonances.",9910375v1
2000-03-09,Dual-Resonance Model and Multiple Production,"The very high multiplicity (VHM) processes are considered to investigate
consequences of the dual resonance models reach (exponential) mass spectrum.
The virial decomposition is developed for description of the produced particles
short-rang (resonance) correlations. It is shown that the reach mass spectrum
is able to do more flat the VHM distribution: $\s_n=O(e^{-n})$ up to
multiplicities $n\simeq\bar{n}^2$, $\bar{n}$ is the mean multiplicity. But for
$n>>\bar{n}^2$ one should expect $\s_n<O(e^{-n})$.",0003078v1
2000-07-25,The Lightest Strange Scalar Resonance,"I present the results of a recent calculation to determine the number of
strange scalar resonances below 1.8 GeV based on the analytic properties of the
experimental pi K scattering amplitude. Only one resonance was found in the
data, and this is readily identifiable as the K_0^*(1430). We found no evidence
to support the kappa(900).",0007275v1
2000-07-26,Probing the Structure of Nucleons in the Resonance Region with CLAS at Jefferson Lab,"The physics of electromagnetic excitation of nucleon resonances and of their
relevance in nucleon structure studies are discussed. Preliminary data from the
CLAS detector on the N-Delta(1232) transition multipoles, the helicity
amplitudes of the N*(1535), and the search for so-called ""missing resonances""
at Jefferson Lab are presented.",0007297v1
2000-11-09,Searching Scalar Resonances with Ultra-high Energy Neutrinos,"We study the prospects of detecting signals of a resonant scattering of
high-energy cosmic neutrinos on electrons in the atmosphere. Such a process is
possible through an s-channel exchange of a isotriplet scalar particle
predicted by some particle physics theories. We estimate the event rates for a
reference detector setup with plausible assumptions on the interaction
strengths and energy resolutions. We find as the most promising process the
resonance production of tau neutrinos whose signature would be a ""quiet"" (in
contrast with a hadronic ""bang"") production of the tau lepton followed by a
more noisy decay in downstream.",0011138v1
2001-06-14,Excitation of Nucleon Resonances,"I discuss developments in the area of nucleon resonance excitations that are
necessary to bring our understanding of nucleon structure in the regime of
strong QCD to a qualitatively new level. They involve the collection of high
quality data in various channels, a more rigorous approach in the search for
""missing"" quark model states, an effort to compute some critical quantities in
nucleon resonance excitations from first principles, i.e. QCD, and a proposal
aimed at obtaining an understanding of a fundamental quantity in nucleon
structure.",0106143v1
2001-10-29,Resonance-reggeon and parton-hadron duality in strong interactions,"By using the concept of duality between direct channel resonances and Regge
exchanges we relate the small- and large-$x$ behavior of the structure
functions. We show that even a single resonance exhibits Bjorken scaling at
large $Q^2$.",0110374v2
2001-11-05,Cuts in the invariant mass of resonances in many body decays of mesons,"Resonance-mediated many body decays of heavy mesons are analyzed. We focus on
some particular processes, in which the available phase space for the decay of
the intermediate resonance is very narrow. It is shown that the mass selection
criteria used in several experimental studies of D and B meson decays could
lead to a significant underestimation of branching ratios.",0111045v2
2001-12-14,Strange Hadron Resonances and QGP Freeze-out,"We describe how the abundance and distribution of hyperon resonances can be
used to probe freeze-out conditions. We demonstrate that resonance yields allow
us to measure the time scales of chemical and thermal freeze-outs. This should
permit a direct differentiation between the explosive sudden, and staged
adiabatic freeze-out scenarios.",0112195v2
2002-01-25,Electroweak Symmetry Breaking by Strong Dynamics and the Collider Phenomenology,"We discuss the possible signatures in the electroweak symmetry breaking
sector by new strong dynamics at future hadron colliders such as the Tevatron
upgrade, the LHC and VLHC, and $e^+e^-$ linear colliders. Examples include a
heavy Higgs-like scalar resonance, a heavy Technicolor-like vector resonance
and pseudo-Goldstone states, non-resonance signatures via enhanced gauge-boson
scattering and fermion compositeness.",0201243v2
2002-03-26,Magnetic moments of the Lambda(1405) and Lambda(1670) resonances,"By using techniques of unitarized chiral perturbation theory, where the
$\Lambda(1405)$ and $\Lambda(1670)$ resonances are dynamically generated, we
evaluate the magnetic moments of these resonances and their transition magnetic
moment. The results obtained here differ appreciably from those obtained with
existing quark models. The width for the $\Lambda(1670) \to \Lambda(1405)
\gamma$ transition is also evaluated leading to a branching ratio of the order
of $2 \times 10^{-6}$.",0203248v1
2002-09-25,Properties of the a0 resonances,"We present results following from the coupled channel model of two a0
resonances decaying into the pi-eta and K anti-K mesons. The a0(980) resonance
can be described by two distinct poles. It is shown that the discrepancy in the
a0(980) mass position between the Crystal Barrel Collaboration and the E852
Group can be explained and removed. In our model with parameters fixed by the
present experimental data the a0(980) cannot be interpreted as a bound K anti-K
state although the K anti-K forces in the S-wave isovector channel are
attractive.",0209304v1
2002-10-25,Studies of New Vector Resonances at the CLIC Multi-TeV e+e- Collider,"Several models predict the existence of new vector resonances in the
multi-TeV region, which can be produced in high energy e+e- collisions in the
s-channel. In this paper we review the existing limits on the masses of these
resonances from LEP/SLC and TEVATRON data and from atomic parity violation in
some specific models. We study the potential of a multi-TeV e+e- collider, such
as CLIC, for the determination of their properties and nature.",0210351v1
2002-10-29,Top quark pair production and decay at linear colliders: signal vs. off resonance background,"Standard Model predictions for the reactions with six fermions in the final
state relevant for top quark pair production and decay at linear colliders are
discussed. An issue of the double resonance signal versus non doubly resonant
background is addresed. Effects related to the off-mass-shell production of the
t\bar{t}-pair are discussed.",0210405v1
2002-12-07,"Single Quark Transition Model Analysis of Electromagnetic Nucleon Resonance Transitions in the [70,1-] Supermultiplet","We apply the single quark transition model to resonance transition amplitudes
extracted from photo-and electroproduction data. We use experimental data on
the S11(1535) and D13(1520) nucleon resonances to extract the amplitudes for
the electromagnetic transition from the nucleon ground state to the [70,1-]
SU(6)xO(3) supermultiplet, and make predictions for the transition amplitudes
of all other states associated with the [70,1-]. We find suprisingly good
agreement with the data.",0212108v1
2003-01-13,Variation of the relative yield of charged and neutral B mesons across the Upsilon(4S) resonance,"It is shown that the ratio of the production rates of the pairs (B+ B-) and
(B0 anti-B0) should experience a substantial and rapid variation with energy
within the width of the Upsilon(4S) resonance, crossing the value of one near
the center of the resonance. This behavior is due to an interference of the
rapidly changing with energy Breit-Wigner phase with the phase introduced in
the wave function of charged mesons by their Coulomb interaction.",0301076v1
2003-01-19,Spin-5/2 resonance effects in a coupled channel nucleon resonance analysis,"Spin-$\ffh$ resonance contributions in pion-nucleon scattering are
investigated within the coupled channel $K$-matrix approach for c.m. energies
up to $\sqrt s=$ 2 GeV. All previously studied $\pi N$, $2\pi N$, $\eta N$, $K
\Lambda$, $K \Sigma$, and $\omega N$ final states are included. We find a
significant improvement of $\chi^2$ in almost all channels by inclusion of the
spin-$\ffh$ states. The obtained coupling parameters are discussed.",0301152v1
2003-04-10,Reconciling the Light Scalar Mesons with Breit-Wigner Resonances as well as the Quark Model,"Resonances appearing in hadronic scattering processes are described by a
two-phase model. In the one phase, scattering products are observed, whereas
the other phase describes confinement. A so-called ``Resonance-Spectrum
Expansion'' is derived, containing expressions that resemble Breit-Wigner
formulae. This method also provides a straightforward explanation for the
origin of the light scalar mesons without requiring extra degrees of freedom.",0304105v1
2003-07-14,Collision times in pi-pi and pi-K scattering and spectroscopy of meson resonances,"Using the concept of collision time (time delay) introduced by Eisenbud and
Wigner and its connection to on-shell intermediate unstable states, we study
mesonic resonances in pi-pi and pi-K scattering. The time-delay method proves
its usefulness by revealing the spectrum of the well-known rho- and K*-mesons
and by supporting some speculations on rho-mesons in the 1200 MeV region. We
use this method further to shed some light on more speculative meson
resonances, among others the enigmatic scalars. We confirm the existence of
chiralons below 1 GeV in the unflavoured and strange meson sector.",0307184v1
2003-08-27,Z^* Resonances: Phenomenology and Models,"We explore the phenomenology of, and models for, the Z^* resonances, the
lowest of which is now well established, and called the Theta. We provide an
overview of three models which have been proposed to explain its existence
and/or its small width, and point out other relevant predictions, and potential
problems, for each. The relation to what is known about KN scattering,
including possible resonance signals in other channels, is also discussed.",0308286v2
2003-09-21,The properties of the $σ$ and $κ$ resonances in a new unitarization approach,"A new unitarization approach is discussed and applied to study the elastic
$\pi K$ scattering process. The existence of the light $\kappa$ resonance is
firmly established if the scattering length in the I=1/2 channel does not
deviate too much from its value obtained from chiral perturbation theory, and a
precise determination to the mass and width of the $\kappa$ resonance requires
a precise determination of the scattering length parameter.",0309242v1
2003-12-02,Chiral Symmetry and Resonances,"A review on the requirements of chiral symmetry on effective quark models is
presented. The connection between the pion Salpeter amplitude and the mass gap
equation is discussed. Hadronic scattering, notably, $\pi\pi$ scattering is
presented. The constraints imposed by chiral symmetry between difractive quark
scattering and quark-quark annihilation is presented. Hadronic coupled channels
as a consequence of quark-quark annihilation are discussed together with the
$^3P_0$ mecahnism. Graphical-rules diagrams are intoduced as a means to
evaluate hadronic coupled channel transition potentials. Their role in finding
transition potentials responsible, in the scalar sector, for low energy
resonances, predicted long ago, and found recently, is also discussed.",0312035v1
2003-12-19,Dynamics and freeze-out of hadron resonances at RHIC,"Yields, rapidity and transverse momentum spectra of $\Delta^{++}(1232)$,
$\Lambda(1520)$, $\Sigma^\pm(1385)$ and the meson resonances $K^0(892)$,
$\Phi$, $\rho^0$ and $f_0(980)$ are predicted. Hadronic rescattering leads to a
suppression of reconstructable resonances, especially at low $p_\perp$. A mass
shift of the $\rho$ of 10 MeV is obtained from the microscopic simulation, due
to late stage $\rho$ formation in the cooling pion gas.",0312278v1
2004-04-01,<VAP> Green Function in the Resonance Region,"We analyse the <VAP> three-point function of vector, axial-vector and
pseudoscalar currents. In the spirit of large N_C, a resonance dominated Green
function is confronted with the leading high-energy behaviour from the operator
product expansion. The matching is shown to be fully compatible with a chiral
resonance Lagrangian and it allows to determine some of the chiral low-energy
constants of O(p^6).",0404004v2
2004-06-22,"Baryons, IN_c","Excited baryons may be analyzed in the 1/N_c expansion as true resonances in
scattering amplitudes. The key idea making this program possible is a
generalization of methods originally applied to chiral soliton models in the
1980's. One finds model-independent relations among amplitudes that impose mass
and width degeneracies among resonances of various quantum numbers.
Phenomenological evidence demonstrates that patterns of resonant decay
predicted by 1/N_c agree with data. The analysis can be extended to subleading
orders in 1/N_c, where again agreement with data is evident.",0406236v1
2004-06-28,Studies of resonance conditions on neutrino oscillations in matter,"We analytically discuss the resonance conditions among several neutrinos in
matter. The discriminant for the characteristic equation of the Hamiltonian is
expressed by the coefficients of the equation. The result of the computation
for the discriminants tells us that the neutrino energy and the matter density
are in inverse proportion to each other at the resonance states in not only 2-
but also 3- and 4-neutrino models.",0406307v3
2004-06-28,"Resonances, and mechanisms of Theta-production","After explaining necessity of exotic hadrons, we discuss mechanisms which
could determine production of the exotic Theta-baryon. A possible important
role of resonances (producing the Theta in real or virtual decays) is
emphasized for various processes. Several experimental directions for studies
of such resonances, and the Theta itself, are suggested. We briefly discuss
also recent negative results on the Theta-baryon.",0406312v1
2004-07-15,Is the a0(980) resonance a K anti-K bound state?,"We have analysed properties of two resonances a0(980) and a0(1450) using the
pion-eta and K anti-K coupled channel model. Although the forces in the
scalar-isovector K anti-K channel are attractive the a0(980) resonance cannot
be interpreted as a kaon-antikaon bound state within our model.",0407175v1
2004-07-29,Extracting beta and the new D_{sJ} resonances,"The three body decays $B \to D^{(*)} \bar{D}^{(*)} K_s$ may be used to
measure both $\sin{2\beta}$ and $\cos{2\beta}$. Crucial to the $\cos{2\beta}$
measurement is the resonant contribution to the three body decay from p-wave
excited $D_s$ states. If these p-wave states are the newly discovered
$D_s(2317)$ and $D_s(2460)$ then they are below the $D^{(*)} K$ threshold and
hence do not contribute to $B \to D^{(*)} \bar{D}^{(*)} K_s$. The three body
decays can then be used to measure $\sin{2\beta}$ without resonant dilution and
to look for new physics in $ b \to c \bar{c} s $ transition.",0407330v1
2004-11-03,New Signatures For Top In Hadron Collider,"We study the signatures for new TeV resonances that couple to top or bottom
quarks both at the Tevatron Run II and at the LHC. We find that it is possible
to study these resonances when they are produced in association with a pair of
heavy quarks or in association with a single top at the LHC. In particular,
with an integrated luminosity of 300 fb$^{-1}$ at the LHC, it is possible to
probe resonance masses up to around 2 TeV.",0411055v1
2004-12-16,Pentaquark Resonances from Collision Times,"Having successfully explored the existing relations between the S-matrix and
collision times in scattering reactions to study the conventional baryon and
meson resonances, the method is now extended to the exotic sector. To be
specific, the collision time in various partial waves of K+ N elastic
scattering is evaluated using phase shifts extracted from the K+ N --> K+ N
data as well as from model dependent T-matrix solutions. We find several
pentaquark resonances including some low-lying ones around 1.5 to 1.6 GeV in
the P_01, P_03 and D_03 partial waves of K+ N elastic scattering.",0412240v1
2005-07-08,Resonances and Electroweak Observables at the ILC,"Precise measurements of the interactions of electroweak vector bosons at the
ILC yield information about the physics of electroweak symmetry breaking. In
order to combine this with the possible observation of new resonances or the
effects of new strong interactions at the LHC, we need to relate resonance
parameters with low-energy observables. We derive these relations for a generic
setup and draw conclusions about the new-physics reach of the ILC in the
electroweak sector.",0507099v1
2005-12-20,Associate Higgs and Gauge Boson Production at Hadron Colliders in a Model with Vector Resonances,"Motivated by new models of dynamical electroweak symmetry breaking that
predict a light composite higgs boson, we build an effective lagrangian which
describes the Standard Model (with a light Higgs) and vector resonances. We
compute the cross section for the associate production of a higgs and a gauge
boson. For some values of model parameters we find that the cross section is
significantly enhanced with respect to the Standard Model. This enhancement is
similar at the LHC and the Tevatron for the same range of resonance mass.",0512261v2
2005-12-22,On charm scalar resonances,"A brief overview of charm scalar resonances is given. It is demonstrated that
experimental data on the D_s^{*+}gamma and D_s^+pi^0 decays of D_{s0}^+(2317)
favor its assignment to the I_3=0 component of iso-triplet four-quark mesons.
The broad bump just below a large peak of the well-known D_2^* meson in the Dpi
channel is also studied.",0512285v1
2005-12-27,The Nucleon and Roper Resonance in a Chiral Quark Diquark Model,"A description of the nucleon and Roper resonance in a quark-diquark approach
is presented. We show that two states with the quantum number of the nucleon
can appear in the ground state of the spatial configuration, when there are two
types of diquarks: scalar-isoscalar and axial-vector-isovector diquarks. The
mass difference between the two states is generated by the mass difference
between the two diquarks, which is due to the spin-spin interaction between the
two quarks in the diquarks. The two states are then identified with the nucleon
and Roper resonance.",0512336v1
2006-02-02,V+A and V-A Correlators at Large NC: From OPE to Resonance Theory,"The spin-1 correlators are analysed in this talk through a large NC resonance
theory. The matching to perturbative QCD and the first terms in the OPE
constrains the hadronic parameters. A further sum-rule analysis shows the wider
range of validity of the resonance description, which can help to discern the
proper structure of the QCD mass spectrum.",0602021v1
2006-02-02,Using Invisible Graviton Radiation to Detect Heavy Electroweak Resonances at a 500 GeV e+e- Collider,"The process e+e- --> mu+ mu- + missing E_T, where the missing energy is due
to the production of a tower of invisible graviton states in a model with large
extra dimensions, is considered. We focus on the scenario when this process is
used to detect a heavy dileptonic resonance in the electroweak sector of the
model, taking as example some models with an extra Z' boson. It turns out that
at a 500 GeV machine with 1000 inverse fb of luminosity, it may be possible to
use this process to such detect resonances if there are two large extra
dimensions and the string scale is not too far above a TeV.",0602022v1
2006-08-16,Possible new resonance at the $D^* {\bar D^*}$ threshold in $e^+e^-$ annihilation,"We argue that the recent CLEO-c data on $e^+e^-$ annihilation into pairs of
charmed mesons at c.m. energy around 4.0 GeV are not well described by a single
resonance $\psi(4040)$, but can be better understood if there is an additional
narrow resonance with mass within few MeV from the $D^* {\bar D}^*$ threshold.",0608179v1
2006-11-20,Photon - Axion Conversion Cross Sections in a Resonant Cavity,"Photon - axion conversions in the resonant cavity with the lowest mode are
considered in detail by the Feynman diagram method. The differential cross
sections are presented and numerical evaluations are given. It is shown that
there is a resonant conversion for the considered process, in which the
conversion cross sections are much larger than those of the wave guide in the
same conditions. Some estimates for experimental conditions are given from our
results.",0611258v1
2006-12-12,To see the exotic Theta^+ baryon from interference,"Since all couplings of the exotic $\Theta^+$ baryon to normal hadrons seem to
be small it is hard to reveal it in standard resonance searching. We suggest to
look for the $\Theta^+$ production in interference with a known resonance
yielding the same final state but having a high production rate. The
interference process is linear in the $\Theta^+$ couplings whereas the
non-interference process is quadratic. That gives an obvious gain if the
couplings are small. Moreover, employing the peculiar oscillating nature of the
interference processes one can reduce considerably the parasitic background and
determine the $\Theta^+$ resonance parameters.",0612150v1
2006-12-22,Chiral Effective Field Theory in the Delta-resonance region,"I discuss the problem of constructing an effective low-energy theory in the
vicinity of a resonance or a bound state. The focus is on the example of the
$\Delta(1232)$, the lightest resonance in the nucleon sector. Recent
developments of the chiral effective-field theory in the $\Delta$-resonance
region are briefly reviewed. I conclude with a comment on the merits of the
manifestly covariant formulation of chiral EFT in the baryon sector.",0612303v1
2007-01-26,A Missing Link Between Quark-Model Resonant States and Scattering-Matrix Singularities,"For last two decades different quark models have predicted diverse, sometimes
contradictory collections of resonant states. To choose the best among them,
the obtained sets had to be compared to available experimental values. In the
absence of a more thorough understanding, quark-model resonant states have been
directly identified with scattering-matrix singularities. We demonstrate that
these are two closely related, but different physical quantities, and offer a
model based on the coupled-channel formalism to connect them in an unambiguous
way.",0701224v1
2007-01-27,Partial waves and large $N_C$ resonance sum rules,"Using $1/N_C$ expansion and dispersion theory techniques, without relying on
any explicit resonance lagrangian, we generalize the KSRF relation beyond the
leading chiral order. Two sum rules for the low energy constants $L_2$, $L_3$
and a new relation between resonance couplings are derived. A rather detailed
examination to the new relation is also given.",0701232v2
2007-02-23,Testing Time-Reversal: Lambda_b Decays into Polarized Resonances,"Weak decays of beauty baryons like Lambda_b into Lambda V(J^P=1^-), where the
produced resonances are polarized, offer interesting opportunity to perform
tests of Time-Reversal Invariance. This paper emphasizes the particular role of
the resonance polarization-vectors and their physical properties by symmetry
transformations. In particular, it is shown that the normal component of a
polarization-vector, as defined in the Jackson's frame, is Lorentz invariant
and could get large values, notably in the case of J/psi production.",0702240v1
1991-09-04,World Sheet and Space Time Physics in Two Dimensional (Super) String Theory,"We show that tree level ``resonant'' $N$ tachyon scattering amplitudes, which
define a sensible ``bulk'' S -- matrix in critical (super) string theory in any
dimension, have a simple structure in two dimensional space time, due to
partial decoupling of a certain infinite set of discrete states. We also argue
that the general (non resonant) amplitudes are determined by the resonant ones,
and calculate them explicitly, finding an interesting analytic structure.
Finally, we discuss the space time interpretation of our results.",9109005v1
1999-10-27,Integrable Quantum Field Theories with Unstable Particles,"A new family of S-matrix theories with resonance poles is constructed and
conjectured to correspond to the Homogeneous sine-Gordon theories associated
with simply laced compact Lie groups, where some of the resonance poles can be
traced to the presence of unstable particles in the spectrum. These theories
are unitary in the usual S S^\dagger =1 sense, they are not parity invariant,
and they exhibit continuous coupling constants that determine both the mass
spectrum of stable particles and the masses and the position of the resonance
poles.",9910218v2
2005-03-02,Analysis of resonance production using relativistic Gamow vectors,"The calculation of an amplitude involving resonance production is presented.
This calculation employs for the resonance state a relativistic Gamow vector.
It is used for investigating the question of compatibility of the relativistic
Gamow vectors kinematics, defined by real 4-velocities and complex mass, with
the stable particle kinematics; or in other words, the integration of the Gamow
vectors with the conventional Dirac bra-ket formalism. The calculation
demonstrates a consistent framework comprising stable and Gamow vectors.",0503023v1
2006-07-24,Above Barrier Dirac Multiple Scattering and Resonances,"We extend an above barrier analysis made with the Schrodinger equation to the
Dirac equation. We demonstrate the perfect agreement between the barrier
results and back to back steps. This implies the existence of multiple (indeed
infinite) reflected and transmitted wave packets. These packets may be well
separated in space or partially overlap. In the latter case interference
effects can occur. For the extreme case of total overlap we encounter
resonances. The conditions under which resonance phenomena can be observed is
discussed and illustrated by numerical calculations.",0607175v1
2006-10-07,Scattering of a relativistic scalar particle by a cusp potential,"We solve the Klein-Gordon equation in the presence of a spatially
one-dimensional cusp potential. The scattering solutions are obtained in terms
of Whittaker functions and the condition for the existence of transmission
resonances is derived. We show the dependence of the zero-reflection condition
on the shape of the potential. In the low momentum limit, transmission
resonances are associated with half-bound states. We express the condition for
transmission resonances in terms of the phase shifts.",0610083v1
2007-02-22,Resonant states in an attractive one dimensional cusp potential,"We solve the two-component Dirac equation in the presence of a spatially one
dimensional symmetric attractive cusp potential. The components of the spinor
solution are expressed in terms of Whittaker functions. We compute the bound
states solutions and show that, as the potential amplitude increases, the
lowest energy state sinks into the Dirac sea becoming a resonance. We
characterize and compute the lifetime of the resonant state with the help of
the phase shift and the Breit-Wigner relation. We discuss the limit when the
cusp potential reduces to a delta point interaction.",0702183v1
1998-09-17,Operator interpretation of resonances generated by some operator matrices,"We consider the analytic continuation of the transfer function for a 2x2
matrix Hamiltonian into the unphysical sheets of the energy Riemann surface. We
construct a family of non-selfadjoint operators which reproduce certain parts
of the transfer-function spectrum including resonances situated on the
unphysical sheets neighboring the physical sheet. On this basis, completeness
and basis properties for the root vectors of the transfer function (including
those for the resonances) are proved.",9809093v1
1999-03-19,Scattering poles for asymptotically hyperbolic manifolds,"For a class of manifolds that includes quotients of real hyperbolic space by
a convex co-compact discrete group, we show that the resonances of the
meromorphically continued resolvent kernel for the Laplacian coincide, with
multiplicities, with the poles of the meromorphically continued scattering
operator. In order to carry out the proof, we use Shmuel Agmon's perturbation
theory of resonances to show that both resolvent resonances and scattering
poles are simple for generic potential perturbations.",9903118v2
2001-11-13,Statistical analysis of stochastic resonance with ergodic diffusion noise,"A subthreshold signal is transmitted through a channel and may be detected
when some noise -- with known structure and proportional to some level -- is
added to the data. There is an optimal noise level, called stochastic
resonance, that corresponds to the highest Fisher information in the problem of
estimation of the signal. As noise we consider an ergodic diffusion process and
the asymptotic is considered as time goes to infinity. We propose consistent
estimators of the subthreshold signal and we solve further a problem of
hypotheses testing. We also discuss evidence of stochastic resonance for both
estimation and hypotheses testing problems via examples.",0111153v1
2004-08-02,Conservation of resonant periodic solutions for the one-dimensional nonlinear Schroedinger equation,"We consider the one-dimensional nonlinear Schr\""odinger equation with
Dirichlet boundary conditions in the fully resonant case (absence of the
zero-mass term). We investigate conservation of small amplitude
periodic-solutions for a large set measure of frequencies. In particular we
show that there are infinitely many periodic solutions which continue the
linear ones involving an arbitrary number of resonant modes, provided the
corresponding frequencies are large enough and close enough to each other (wave
packets with large wave number).",0408017v1
2005-01-27,Transition from rotating waves to modulated rotating waves on the sphere,"We study non-resonant and resonant Hopf bifurcation of a rotating wave in
SO(3)-equivariant reaction-diffusion systems on a sphere. We obtained reduced
differential equations on so(3), the characterization of modulated rotating
waves obtained by Hopf bifurcation of a rotating wave, as well as results
regarding the resonant case. Our main tools are the equivariant center manifold
reduction and the theory of Lie groups and Lie algebras, especially for the
group SO(3) of all rigid rotations on a sphere.",0501492v1
2006-06-08,Transport in the One-Dimensional Schroedinger Equation,"We prove a dispersive estimate for the one-dimensional Schroedinger equation,
mapping between weighted $L^p$ spaces with stronger time-decay ($t^{-3/2}$
versus $t^{-1/2}$) than is possible on unweighted spaces. To satisfy this
bound, the long-term behavior of solutions must include transport away from the
origin. Our primary requirements are that $(1+|x|)^3 V$ be integrable and
$-\Delta + V$ not have a resonance at zero energy. If a resonance is present
(for example in the free case), similar estimates are valid after projecting
away from a rank-one subspace corresponding to the resonance.",0606172v2
2006-07-25,Multiplicity of nontrivial solutions for elliptic equations with nonsmooth potential and resonance at higher eigenvalues,"We consider a semilinear elliptic equation with a nonsmooth, locally
\hbox{Lipschitz} potential function (hemivariational inequality). Our
hypotheses permit double resonance at infinity and at zero (double-double
resonance situation). Our approach is based on the nonsmooth critical point
theory for locally Lipschitz functionals and uses an abstract multiplicity
result under local linking and an extension of the Castro--Lazer--Thews
reduction method to a nonsmooth setting, which we develop here using tools from
nonsmooth analysis.",0607621v1
2007-01-16,Lyapunov functions for periodic matrix-valued Jacobi operators,"We consider periodic matrix-valued Jacobi operators. The spectrum of this
operator is absolutely continuous and consists of intervals separated by gaps.
We define the Lyapunov function, which is analytic on an associated Riemann
surface. On each sheet the Lyapunov function has the standard properties of the
Lyapunov function for the scalar case. We show that this function has (real or
complex) branch points, which we call resonances. We prove that there exist two
types of gaps: i) stable gaps, i.e., the endpoints are periodic and
anti-periodic eigenvalues, ii) unstable (resonance) gaps, i.e., the endpoints
are resonances (real branch points). We show that some spectral data determine
the spectrum (counting multiplicity) of the Jacobi operator.",0701448v1
2004-08-03,Weakly resonant tunneling interactions for adiabatic quasi-periodic Schrodinger operators,"In this paper, we study spectral properties of the one dimensional periodic
Schrodinger operator with an adiabatic quasi-periodic perturbation. We show
that in certain energy regions the perturbation leads to resonance effects
related to the ones observed in the problem of two resonating quantum wells.
These effects affect both the geometry and the nature of the spectrum. In
particular, they can lead to the intertwining of sequences of intervals
containing absolutely continuous spectrum and intervals containing singular
spectrum. Moreover, in regions where all of the spectrum is expected to be
singular, these effects typically give rise to exponentially small ""islands"" of
absolutely continuous spectrum.",0408006v1
2004-08-26,Schrödinger operators with complex-valued potentials and no resonances,"In dimension $d\geq 3$, we give examples of nontrivial, compactly supported,
complex-valued potentials such that the associated Schr\""odinger operators have
no resonances. If $d=2$, we show that there are potentials with no resonances
away from the origin. These Schr\""odinger operators are isophasal and have the
same scattering phase as the Laplacian on $\Real^d$. In odd dimensions $d\geq
3$ we study the fundamental solution of the wave equation perturbed by such a
potential. If the space variables are held fixed, it is super-exponentially
decaying in time.",0408052v1
2004-09-09,Approximating resonances with the Complex Absorbing Potential Method,"We study the Complex Absorbing Potential (CAP) Method in computing quantum
resonances of width $c(h) = O(h^N)$, $N\gg1$. We show that up to
$h^{-M}\sqrt{c(h)} +\Oh$ error, $M\gg1$, resonances are perturbed eigenvalues
of the CAP Hamiltonian $P(h)-iW$, and vice versa, where $W$ is the CAP with
non-negative real part supported outside the trapping region. In some cases,
the error terms are exponentially small.",0409020v1
2005-07-25,A general resonance theory based on Mourre's inequality,"We study the perturbation of bound states embedded in the continuous spectrum
which are unstable by the Fermi Golden Rule. The approach to resonance theory
based on spectral deformation is extended to a more general class of quantum
systems characterized by Mourre's inequality and smoothness of the resolvent.
Within the framework of perturbation theory it is still possible to give a
definite meaning to the notion of complex resonance energies and of
corresponding metastable states. The main result is a quasi-exponential decay
estimate up to a controlled error of higher order in perturbation theory.",0507063v1
2005-09-26,Fractional Lindstedt series,"The parametric equations of the surfaces on which highly resonant
quasi-periodic motions develop (lower-dimensional tori) cannot be analytically
continued, in general, in the perturbation parameter, i.e. they are not
analytic functions of the perturbation parameter. However rather generally
quasi-periodic motions whose frequencies satisfy only one rational relation
(""resonances of order 1"") admit formal perturbation expansions in terms of a
fractional power of the perturbation parameter, depending on the degeneration
of the resonance. We find conditions for this to happen, and in such a case we
prove that the formal expansion is convergent after suitable resummation.",0509056v1
2005-11-04,The capture into parametric autoresonance,"In this work we show that the capture into parametric resonance may be
explained as the pitchfork bifurcation in the primary parametric resonance
equation. We prove that the solution close to the moment of the capture is
described by the Painleve-2 equation. We obtain the connection formulas for the
asymptotic solution of the primary parametric resonance equation before and
after the capture using the matching of the asymptotic expansions.",0511017v1
2006-01-07,Level shift operators for open quantum systems,"Level shift operators describe the second order displacement of eigenvalues
under perturbation. They play a central role in resonance theory and ergodic
theory of open quantum systems at positive temperatures.
  We exhibit intrinsic properties of level shift operators, properties which
stem from the structure of open quantum systems at positive temperatures and
which are common to all such systems. They determine the geometry of resonances
bifurcating from eigenvalues of positive temperature Hamiltonians and they
relate the Gibbs state, the kernel of level shift operators, and zero energy
resonances.
  We show that degeneracy of energy levels of the small part of the open
quantum system causes the Fermi Golden Rule Condition to be violated and we
analyze ergodic properties of such systems.",0601013v1
2006-05-09,The width of resonances for slowly varying perturbations of one-dimensional periodic Schrödinger operators,"In this talk, we report on results about the width of the resonances for a
slowly varying perturbation of a periodic operator. The study takes place in
dimension one. The perturbation is assumed to be analytic and local in the
sense that it tends to a constant at $+\infty$ and at $-\infty$; these
constants may differ. Modulo an assumption on the relative position of the
range of the local perturbation with respect to the spectrum of the background
periodic operator, we show that the width of the resonances is essentially
given by a tunneling effect in a suitable phase space.",0605031v1
2006-10-25,Equivalence of resolvent and scattering resonances on quantum graphs,"We discuss resonances for Schr\""odinger operators on metric graphs which
consists of a finite compact part and a finite number of halflines attached to
it; the vertex coupling is assumed to be of the $\delta$-type or certain
modifications of it. Using exterior complex scaling on the graph we show that
the resolvent and scattering resonances coincide in this case.",0610065v1
2000-02-16,Turing Patterns in Nonlinear Optics,"The phenomenon of pattern formation in nonlinear optical resonators is
commonly related to an off-resonance excitation mechanism, where patterns occur
due to mismatch between the excitation and resonance frequency. In this paper
we show that the patterns in nonlinear optics can also occur due to the
interplay between diffractions of coupled field components. The reported
mechanism is analogous to that of local activation and lateral inhibition found
in reaction-diffusion systems by Turing. We study concretely the degenerate
optical parametric oscillators. A local activator-lateral inhibitor mechanism
is responsible for generation of Turing patterns in form of hexagons.",0002022v1
2000-03-07,Spatial Solitons in Resonators,"We describe experiments testing the existence and investigating the
properties of spatial solitons in nonlinear resonators. We investigate the
properties of stationary and moving spatial solitons in lasers with saturable
absorber, with a subcritical bifurcation, as well as their manipulation. As
opposed, spatial solitons relying on a supercritical bifurcation are shown to
exist in degenerate 4-wave mixing (DOPO). With a view to technical applications
in parallel information processing or communication, experiments on spatial
solitons in large area quantum well semiconductor resonators are conducted.",0003015v1
2000-04-04,Quantum fingerprints of classical Ruelle-Pollicot resonances,"N-disk microwave billiards, which are representative of open quantum systems,
are studied experimentally. The transmission spectrum yields the quantum
resonances which are consistent with semiclassical calculations. The spectral
autocorrelation of the quantum spectrum is shown to be determined by the
classical Ruelle-Pollicot resonances, arising from the complex eigenvalues of
the Perron-Frobenius operator. This work establishes a fundamental connection
between quantum and classical correlations in open systems.",0004006v1
2000-05-08,Amplification of weak signals and stochastic resonance via on-off intermittency with symmetry breaking,"Nonlinear dynamical systems possessing reflection symmetry have an invariant
subspace in the phase space. The dynamics within the invariant subspace can be
random or chaotic. As a system parameter changes, the motion transverse to the
invariant subspace can lose stability, leading to on-off intermittency. Under
certain conditions, the bursting behavior is symmetry-breaking. We demonstrate
the possibility of observing multiplicative noise(chaos)-induced amplification
of weak signal and stochastic resonance via on-off intermittency with symmetry
breaking in a general class of symmetrical systems. Differences of this
mechanism of stochastic resonance to that in noisy bistable or threshold
systems are discussed",0005013v1
2000-07-08,Optical Solitons in Periodic Media with Resonant and Off-Resonant Nonlinearities,"The properties of optical solitons in periodic nonlinear media are reviewed.
The emphasis is on solitons in periodically refractive media (Bragg gratings)
incorporating a periodic set of thin layers of two-level systems resonantly
interacting with the field. Such media support a variety of bright and dark
`gap solitons' propagating in the band gaps of the Bragg gratings, as well as
their multi - dimensional analogs (light bullets). These novel gap solitons
differ substantially from their counterparts in periodic media with either
cubic or quadratic off-resonant nonlinearities.",0007007v1
2000-07-22,Three-frequency resonances in dynamical systems,"We investigate numerically and experimentally dynamical systems having three
interacting frequencies: a discrete mapping (a circle map), an exactly solvable
model (a system of coupled ordinary differential equations), and an
experimental device (an electronic oscillator). We compare the hierarchies of
three-frequency resonances we find in each of these systems. All three show
similar qualitative behaviour, suggesting the existence of generic features in
the parameter-space organization of three-frequency resonances.",0007030v1
2000-08-25,Geometric Numerical Integration Applied to The Elastic Pendulum at Higher Order Resonance,"In this paper we study the performance of a symplectic numerical integrator
based on the splitting method. This method is applied to a subtle problem i.e.
higher order resonance of the elastic pendulum. In order to numerically study
the phase space of the elastic pendulum at higher order resonance, a numerical
integrator which preserves qualitative features after long integration times is
needed. We show by means of an example that our symplectic method offers a
relatively cheap and accurate numerical integrator.",0008033v1
2001-03-26,Dissipation induced Instabilities and the Mechanical Laser,"We study the 1:1 resonance for perturbed Hamiltonian systems with small
dissipative and energy injection terms. These perturbations of the 1:1
resonance exhibit dissipation induced instabilities. This mechanism allow us to
show that a slightly pumping optical cavity is unstable when one takes into
account the dissipative effects. The Maxwell-Bloch equations are the asymptotic
normal form that describe this instability when energy is injected through
forcing at zero frequency. We display a simple mechanical system, close to the
1:1 resonance, which is a mechanical analog of the Laser.",0103049v1
2001-05-01,Rectangular microwave resonators with magnetic anisotropy. Mapping onto pseudo integrable rhombus,"The rectangular microwave resonator filed by a ferrite with uniaxial magnetic
anisotropy is considered. It is shown that this task can be reduced to an empty
rhombus resonator with vertex angle defined by external magnetic field provided
the magnetic anisotropy of the ferrite is strong. Therefore statistics of eigen
frequencies for TM modes is described by the Brody or semi-Poisson distribution
with some exceptional cases.",0105001v1
2002-01-29,Isolated resonances in conductance fluctuations and hierarchical states,"We study the isolated resonances occurring in conductance fluctuations of
quantum systems with a classically mixed phase space. We demonstrate that the
isolated resonances and their scattering states can be associated to
eigenstates of the closed system. They can all be categorized as hierarchical
or regular, depending on where the corresponding eigenstates live in the
classical phase space.",0201057v3
2002-07-01,Complex Ginzburg-Landau equation for self-oscillatory systems under amplitude modulated forcing in a 1:1 resonance,"The dynamics of self-oscillatory extended systems, resonantly forced at a
frequency close to that of the natural oscillations (1:1 resonance), is shown
to be universally described by a complex Ginzburg-Landau equation containing an
inhomogeneous term. The case of amplitude modulated forcing is considered,
which generalizes previous studies. Application to the two-frequency forcing in
a 1:1 resonance is considered as an example.",0207004v1
2002-10-22,Dynamical tunneling in molecules: role of the classical resonances and chaos,"In this letter we study dynamical tunneling in highly excited symmetric
molecules. The role of classical phase space structures like resonances and
chaos on the tunneling splittings are illustrated using the water molecule as
an example. It is argued that the enhancements in the splittings due to
resonances (near-integrable phase space) and due to chaos (mixed phase space)
are best understood away from the fluctuations associated with avoided
crossings. In particular we provide an essential difference between the two
mechanisms in terms of high order perturbation theory. The analysis, apart from
testing the validity of a perturbative approach, suggests such systems as prime
candidates for studying dynamical tunneling.",0210051v1
2003-01-18,Statistical properties of resonance widths for open Quantum Graphs,"We connect quantum compact graphs with infinite leads, and turn them into
scattering systems. We derive an exact expression for the scattering matrix,
and explain how it is related to the spectrum of the corresponding closed
graph. The resulting expressions allow us to get a clear understanding of the
phenomenon of resonance trapping due to over-critical coupling with the leads.
Finally, we analyze the statistical properties of the resonance widths and
compare our results with the predictions of Random Matrix Theory. Deviations
appearing due to the dynamical nature of the system are pointed out and
explained.",0301021v1
2003-01-22,Classical Resonances and Quantum Scarring,"We study the correspondence between phase-space localization of quantum
(quasi-)energy eigenstates and classical correlation decay, given by
Ruelle-Pollicott resonances of the Frobenius-Perron operator. It will be shown
that scarred (quasi-)energy eigenstates are correlated: Pairs of eigenstates
strongly overlap in phase space (scar in same phase-space regions) if the
difference of their eigenenergies is close to the phase of a leading classical
resonance. Phase-space localization of quantum states will be measured by $L^2$
norms of their Husimi functions.",0301028v1
2003-03-18,R-matrix theory of driven electromagnetic cavities,"Resonances of cylindrical symmetric microwave cavities are analyzed in
R-matrix theory which transforms the input channel conditions to the output
channels. Single and interfering double resonances are studied and compared
with experimental results, obtained with superconducting microwave cavities.
Because of the equivalence of the two-dimensional Helmholtz and the stationary
Schroedinger equations, the results present insight into the resonance
structure of regular and chaotic quantum billiards.",0303035v2
2003-08-06,Stochastic Resonance in Two Dimensional Landau Ginzburg Equation,"We study the mechanism of stochastic resonance in a two dimensional Landau
Ginzburg equation perturbed by a white noise. We shortly review how to
renormalize the equation in order to avoid ultraviolet divergences. Next we
show that the renormalization amplifies the effect of the small periodic
perturbation in the system. We finally argue that stochastic resonance can be
used to highlight the effect of renormalization in spatially extended system
with a bistable equilibria.",0308009v1
2004-10-20,Fano resonance in quadratic waveguide arrays,"We study resonant light scattering in arrays of channel optical waveguides
where tunable quadratic nonlinearity is introduced as nonlinear defects by
periodic poling of single (or several) waveguides in the array. We describe
novel features of wave scattering that can be observed in this structure and
show that it is a good candidate for the first observation of Fano resonance in
nonlinear optics.",0410041v2
2005-03-23,Resemblances and differences in mechanisms of noise-induced resonance,"Systems showing stochastic resonance (SR) or coherent resonance (CR) share
some features, in particular the nearby periodic character of the signal. We
show that in spite of this resemblance the different underlying dynamics can be
detected in experimental data by studying the histogram of inter-spikes times
and some statistical properties like two-times correlation functions. We
discuss the possible relevance for climate modeling.",0503051v1
2005-07-14,Enhanced soliton transport in quasi-periodic lattices with short-range aperiodicity,"We study linear transmission and nonlinear soliton transport through
quasi-periodic structures, which profiles are described by multiple modulation
frequencies. We show that resonant scattering at mixed-frequency resonances
limits transmission efficiency of localized wave packets, leading to radiation
and possible trapping of solitons. We obtain an explicit analytical expression
for optimal quasi-periodic lattice profiles, where additional aperiodic
modulations suppress mixed-frequency resonances, resulting in dramatic
enhancement of soliton mobility. Our results can be applied to the design of
photonic waveguide structures, and arrays of magnetic micro-traps for atomic
Bose-Einstein condensates.",0507027v1
2005-10-28,Negative-coupling resonances in pump-coupled lasers,"We consider coupled lasers, where the intensity deviations from the steady
state, modulate the pump of the other lasers. Most of our results are for two
lasers where the coupling constants are of opposite sign. This leads to a Hopf
bifurcation to periodic output for weak coupling. As the magnitude of the
coupling constants is increased (negatively) we observe novel amplitude effects
such as a weak coupling resonance peak and, strong coupling subharmonic
resonances and chaos. In the weak coupling regime the output is predicted by a
set of slow evolution amplitude equations. Pulsating solutions in the strong
coupling limit are described by discrete map derived from the original model.",0510072v1
2006-01-04,Ruelle-Pollicott resonances for real analytic hyperbolic map,"We study two simple real analytic uniformly hyperbolic dynamical systems:
expanding maps on the circle S1 and hyperbolic maps on the torus T2. We show
that the Ruelle-Pollicott resonances which describe time correlation functions
of the chaotic dynamics can be obtained as the eigenvalues of a trace class
operator in Hilbert space L2(S1) or L2(T2) respectively. The trace class
operator is obtained by conjugation of the Ruelle transfer operator in a
similar way quantum resonances are obtained in open quantum systems. We comment
this analogy.",0601010v2
2006-02-09,Directed transport and Floquet analysis for a periodically kicked wavepacket at a quantum resonance,"The dynamics of a kicked quantum mechanical wavepacket at a quantum resonance
is studied in the framework of Floquet analysis. It is seen how a directed
current can be created out of a homogeneous initial state at certain resonances
in an asymmetric potential. The almost periodic parameter dependence of the
current is found to be connected with level crossings in the Floquet spectrum.",0602020v1
2006-11-03,Change in the adiabatic invariant in a nonlinear two-mode model of Feshbach resonance passage,"Mean-field approach has recently been used to model coupled atom-molecular
Bose-Einstein condensates (BEC) and coupled Fermi-Bose condensates near
Feshbach resonance. Sweeping of magnetic field across the resonance gives a new
(nonlinear) version of Landau-Zener problem. We investigate the structure of
the corresponding classical phase space and calculate change in the action
which corresponds to finite-rate efficiency of the sweep. We consider the case
of non-zero initial action, which corresponds to some finite initial molecular
fraction.",0611007v2
2007-02-19,Multiple Components in Narrow Planetary Rings,"The phase-space volume of regions of regular or trapped motion, for bounded
or scattering systems with two degrees of freedom respectively, displays
universal properties. In particular, drastic reductions in the volume (gaps)
are observed at specific values of a control parameter. Using the stability
resonances we show that they, and not the mean-motion resonances, account for
the position of these gaps. For more degrees of freedom, exciting these
resonances divides the regions of trapped motion. For planetary rings, we
demonstrate that this mechanism yields rings with multiple components.",0702039v2
2007-02-26,Two-component Analogue of Two-dimensional Long Wave-Short Wave Resonance Interaction Equations: A Derivation and Solutions,"The two-component analogue of two-dimensional long wave-short wave resonance
interaction equations is derived in a physical setting. Wronskian solutions of
the integrable two-component analogue of two-dimensional long wave-short wave
resonance interaction equations are presented.",0702051v2
1998-12-15,"Absolute measurement of the 5/2+ resonance of 36Ar(p,gamma)37K at E_p = 918 keV","The strength of the 5/2+ resonance of the reaction 36Ar(p,gamma)37K at E_p =
918 keV was measured absolutely: omega gamma = (258 \pm 24) meV. The new result
is consistent with previous results. This resonance was used in several
experiments as a calibration standard. Therefore we discuss our experimental
uncertainties in detail which is important for the reliability of previous
experiments and our new result.",9812006v1
2001-09-07,The Nucleon Structure in the Resonance Region,"Recent results on inclusive and exclusive electroproduction experiments at
Jefferson Lab are discussed. They include measurements of the spin responses
for protons and neutrons in and above the resonance region, exclusive single
and double pion production to measure resonance transition multipoles, and
searches for predicted yet unobserved quark model states. A brief outlook into
the new domain of generalized parton distribution is given as well.",0109004v2
2003-07-09,"Thermal properties and radiative strengths in 160,161,162Dy","The level densities and radiative strength functions (RSFs) in 160,161Dy have
been extracted using the (3He,alpha gamma) and (3He,3He' gamma) reactions,
respectively. The data are compared to previous measurements on 161,162Dy. The
energy distribution in the canonical ensemble is discussed with respect to the
nucleon Cooper pair breaking process. The gross properties of the RSF are
described by the giant electric dipole resonance. The RSF at low gamma-ray
energies is discussed with respect to temperature dependency. Resonance
parameters of a soft dipole resonance at Egamma = 3 MeV are deduced.",0307009v1
2003-11-25,Resonance Production in Au+Au and p+p Collisions at $\sqrt{s_{NN}} = $ 200 GeV,"The $\rho^0(770)$, $K^{*0}(892)$, $f_{0}(980)$, $\phi(1020)$, and
$\Lambda(1520)$ production in Au+Au and p+p collisions at $\sqrt{s_{_{NN}}} = $
200 GeV are presented. These resonances are used as a sensitive tool to examine
the collision dynamics in the hadronic medium through their decay and
regeneration. The modification of resonance mass, width, and shape due to phase
space and dynamical effects are also discussed.",0311023v1
2004-03-15,Resonance Production,"Recent results on rho(770)^0, K(892)^*0, f_0(980), phi(1020), Delta(1232)^++,
and Lambda(1520) production in A+A and p+p collisions at SPS and RHIC energies
are presented. These resonances are measured via their hadronic decay channels
and used as a sensitive tool to examine the collision dynamics in the hadronic
medium through their decay and regeneration. The modification of resonance
mass, width, and shape due to phase space and dynamical effects are discussed.",0403026v2
2004-04-01,Strange Resonance Production in p+p and Au+Au Collisions at RHIC Energies,"Resonance yields and spectra from elementary p+p and Au+Au collisions at
$\sqrt{s_{\rm NN}} = $ 200 GeV from the STAR experiment at RHIC are presented
and discussed in terms of chemical and thermal freeze-out conditions. Thermal
models do not adequately describe the yields of the resonance production in
central Au+Au collisions. The approach to include elastic hadronic interactions
between chemical freeze-out and thermal freeze-out suggests a time of $\Delta
\tau>$5 fm/c.",0404003v1
2005-01-24,"Physics at ELSA, achievements and future","At ELSA interesting results on baryon resonances have been obtained by the
CB-ELSA, the CBELSA/TAPS and the SAPHIR collaborations. New resonances were
found, in particular a new $\rm D_{15}(2070)$ decaying into $p\eta$, was
recently observed by the CB-ELSA experiment. The availability of a polarized
beam and a polarized target did allow to measure the GDH sum rule up to 2.9
GeV. In the future double polarization experiments will be performed using the
Crystal Barrel detector together with new forward detector components. These
polarization observables will provide important additional information for the
partial wave analyses performed to extract the contributing resonances and
their parameters from the data.",0501024v1
2005-01-31,Resonance Production in Heavy Ion Collisions,"The resonance production of $\Delta$, K(892), $\Sigma$(1385), $\Lambda$(1520)
and $\phi$ from elementary p+p and Au+Au collisions at $\sqrt{s_{\rm NN}} = $
200 GeV from the STAR experiment at RHIC is presented. Yields and spectra are
discussed in terms of chemical and thermal freeze-out conditions. Thermal
models do not describe sufficiently the yields of the resonance production in
central Au+Au collisions. The approach which includes pseudo-elastic and
elastic hadronic interactions after chemical freeze-out until thermal
freeze-out suggests a time span of $\Delta \tau>$5 fm/c.",0501033v1
2006-08-03,"The Giant Monopole Resonance in the Sn Isotopes: Why is Tin so ""Fluffy""?","The isoscalar giant monopole resonance (GMR) has been investigated in a
series of Sn isotopes (A=112--124) using inelstic scattering of 400-MeV alpha
particles at extremely forward angles (including 0deg). The primary aim of the
investigation has been to explore the role of the ""symmetry-energy"" term in the
expression for nuclear incompressibility. It is found that the energies of the
GMR in the Sn isotopes are significantly lower than those expected from the
nuclear incompressibility previously extracted from the available data on the
compressional-mode giant resonances.",0608007v1
2006-10-24,"The 139La(n,gamma) cross section: key for the onset of the s process","The nuclear resonance parameters and the capture cross section of the neutron
magic isotope 139La has been measured n_TOF. The description of the
experimental apparata is followed by the data analysis procedures. We extracted
the resonance parameters, the main nuclear quantities such as the resonance
integral, the average gamma widths for s- and p-waves, the nuclear level
densities and the neutron strength functions. These results represent a
signifcant improvement over previous data. The deduced Maxwellian-averaged
capture cross sections are important for the interpretation of the most recent
spectroscopic observations in low metallicity stars.",0610034v1
2007-02-09,Characterization of 7H Nuclear System,"The 7H resonance was produced via one-proton transfer reaction with a 8He
beam at 15.4A MeV and a 12C gas target. The experimental setup was based on the
active-target MAYA which allowed a complete reconstruction of the reaction
kinematics. The characterization of the identified 7H events resulted in a
resonance energy of 0.57(+0.42-0.21) MeV above the 3H+4n threshold and a
resonance width of 0.09(+0.94-0.06) MeV.",0702021v1
1993-08-19,Bose-condensation through resonance decay,"We show that a system described by an equation of state which contains a high
number of degrees of freedom (resonances) can create a considerable amount of
superfluid (condensed) pions through the decay of short-lived resonances, if
baryon number and entropy are large and the dense matter decouples from
chemical equilibrium earlier than from thermal equilibrium. The system cools
down faster in the presence of a condensate, an effect that may partially
compensate the enhancement of the lifetime expected in the case of
quark-gluon-plasma formation.",9308015v1
1994-05-04,Escape and Spreading Properties of Charge-Exchange Resonances in Bi 208,"The properties of charge-exchange excitations of ${}^ {208}$Pb with $\Delta L
= 0$, i.e., the isobaric analog and Gamow-Teller resonances, are studied within
a self-consistent model making use of an effective force of the Skyrme type.
The well-known isobaric analog case is used to assess the reliability of the
model. The calculated properties of the Gamow-Teller resonance are compared
with recent experimental measurements with the aim of better understanding the
microscopic structure of this mode.",9405004v1
1995-06-29,Photo- and Electroproduction of Eta Mesons,"Eta photo- and electroproduction off the nucleon is investigated in an
effective lagrangian approach that contains Born terms and both vector meson
and nucleon resonance contributions. In particular, we review and develop the
formalism for coincidence experiments with polarization degrees of freedom. The
different response functions appearing in single and double polarization
experiments have been studied. We will present calculations for structure
functions and kinematical conditions that are most sensitive to details of the
lagrangian, in particular with regard to contributions of nucleon resonances
beyond the dominant $S_{11}$(1535) resonance.",9506029v1
1995-08-10,Fusion reactions in molecules via nuclear threshold resonances,"It is widely accepted that in molecular systems the nuclear interaction plays
a negligible role, because of the strong Coulomb repulsion of the nuclei at
small distances. We are going to show that this is not always true. The
existence of an extended nuclear resonance may lead to considerably enhanced
nuclear reaction rates in appropriately prepared molecules. Especially we point
out that p+p+ ^{16}O, i.e., the constituents of water, can form a ^{18}Ne(1^-)
threshold resonance which decays under energy release into ^{17}F and a proton.",9508017v2
1995-08-18,Does the quark cluster model predict any isospin two dibaryon resonance?,"We analyze the possible existence of a resonance in the $J^P=0^-$ channel
with isospin two by means of nucleon-$\Delta$ interactions based on the
constituent quark model. We solve the bound state and the scattering problem
using two different potentials, a local and a non-local one. The non-local
potential results to be the more attractive, although not enough to generate
the experimentally predicted resonance.",9508031v1
1995-09-04,Updated resonance photo-decay amplitudes to 2 GeV,"We present the results of an energy-dependent and set of single-energy
partial-wave analyses of single-pion photoproduction data. These analyses
extend from threshold to 2 GeV in the laboratory photon energy, and update our
previous analyses to 1.8 GeV. Photo-decay amplitudes are extracted for the
baryon resonances within this energy range. We consider two photoproduction sum
rules and the contributions of two additional resonance candidates found in our
most recent analysis of $\pi N$ elastic scattering data. Comparisons are made
with previous analyses.",9509005v1
1995-10-07,Parity Violation in Neutron-Nucleus Collisions at Very Low Energies,"We investigate parity violation in neutron-nucleus collisions at very low
energy region $(E \leq 100 \ev)$, including resonance states. We use the
coupled channel formalism for resonances with radiative emission. The parity
mixing between resonances with opposite parities is taken into account.
Finally, our theory is applied to $n-^{139}$La collision and relevant remarks
are given.",9510014v1
1996-04-17,Electromagnetic Couplings of Nucleon Resonances,"An effective Lagrangian calculation of pion photoproduction including all
nucleon resonances up to $\sqrt s = 1.7$ GeV is presented. We compare our
results to recent calculations and show the influence of different width
parametrizations and offshell cutoffs on the photoproduction multipoles. We
determine the electromagnetic couplings of the resonances from a new fit to the
multipole data.",9604026v2
1996-06-05,Rescattering effects in coherent pion photoproduction on the deuteron in the $Δ$ resonance region,"Within a dynamical model, rescattering effects are studied in coherent pion
photoproduction on the deuteron in the $\Delta$(1232) resonance region. The
model consists of a system of coupled equations for the N$\Delta$, NN$\pi$ and
NN channels. Pion rescattering leads in general to a significant reduction of
total and differential cross sections resulting in a better description of
experimental data. Only a few polarization observables are sensitive to
rescattering effects. In particular $T_{20}$ allows an analysis of the reaction
mechanism for specific kinematics. The question how rescattering affects the
sensitivity to the E2 excitation of the $\Delta$ resonance is also studied.",9606008v1
1996-06-20,Pseudoscalar meson photoproduction: from known to undiscovered resonances,"The role of dynamics in spin observables for pseudoscalar meson
photoproduction is investigated using a density matrix approach in a multipole
truncated framework. Extraction of novel rules for $\gamma p \rightarrow \pi^+
n,~ K^+ \Lambda$ and $\eta p$ reactions based on resonance dominance, and on
other broad and reasonable dynamical assumptions, are discussed. Observables
that are particularly sensitive to missing nucleonic resonances predicted by
quark-based approaches, are singled out.",9606042v1
1996-12-17,Damping mechanisms of the Delta resonance in nuclei,"The damping mechanisms of the Delta(1232) resonance in nuclei are studied by
analyzing the quasi-free decay reactions 12C(pi+,pi+ p)11B and 12C(3He,t pi+
p)11B and the 2p emission reactions 12C(pi+,pp)10B and 12C(3He,t pp)10B. The
coincidence cross sections are calculated within the framework of the
isobar-hole model. It is found that the 2p emission process induced by the
decay of the Delta resonance in the nucleus can be consistently described by a
pi+rho+g' model for the Delta+N -> N+N decay interaction.",9612046v1
1997-02-18,Pion photoproduction in the delta resonance region,"We have updated our multipole analyses to incorporate new data from the
low-energy and delta resonance regions. We note a slight decrease in our
estimate of the delta photo-decay amplitudes. This agrees with results found in
Compton scattering. Our values are also in good agreement with a previous RPI
determination. We have reexamined our determinations of the E2/M1 ratio at the
resonance energy and at the pole. We find an E2/M1 ratio (at the pole) which is
in good agreement with recent the Mainz value.",9702039v2
1997-03-18,Exploration of resonances by analytic continuation in the coupling constant,"The energy and the width of resonance states are determined by analytic
continuation of bound-state energies as a function of the coupling constant
(potential strength). The advantage of the method is that the existing
techniques for calculation of bound states can be applied, without any
modifications, to determine the position of resonances. Various numerical
examples show the applicability of the method for three-body systems, including
the excited states of the $^6$He and $^6$Li.",9703038v1
1997-06-03,An Unified Approach To Pseudo Scalar Meson Photoproductions Off Nucleons In The Quark Model,"An unified approach to the pseudo scalar meson ($\pi, \eta$, and $K$)
photoproduction off nucleons are presented. It begins with the low energy QCD
Lagrangian, and the resonances in the s- and u- channels are treated in the
framework of the quark model
  The duality hypothesis is imposed to limit the number of the t-channel
exchanges. The CGLN amplitudes for each reaction are evaluated, which include
both proton and neutron targets. The important role by the S-wave resonances in
the second resonance region is discussed, it is particularly important for the
$K, \eta$ and $\eta^\prime$ photoproductions.",9706010v1
1997-06-17,Kaon Productions Off Nucleons And The Structure of Baryon Resonances,"The recent Investigations in the chiral quark model show that kaon
productions of nucleon play an important role in understanding the structure of
baryons. The evidences of a third $S_{11}$ resonance in the second resonance
region and two narrow states around 2 GeV suggest a set of the molecular type
baryons with hidden strangeness. Confirming these states requires further
theoretical and experimental studies of the strangeness production.",9706040v1
1997-12-08,Transitions between complex configurations in the excitation of the Double Giant Resonance,"The transitions between complex configurations, to which the giant dipole
resonance (GDR) and the double giant dipole resonance (DGDR) doorway states are
coupled, are taken into account in second order perturbation theory for the
reaction amplitude. It is proved that only transitions between GDR and DGDR
doorway states play an essential role in the Coulomb excitation of the DGDR.",9712028v1
1998-02-11,Dynamics of kaons in nuclear matter,"We consider $K^-$ nucleon elastic and inelastic scattering in isospin
symmetric nuclear matter. It is found that the proper description of the
$\Lambda(1405)$ resonance structure in nuclear matter requires a
self-consistent approach. Then the $\Lambda (1405) $ resonance mass remains
basically unchanged, however, the resonance acquires an increased decay width
as nuclear matter is compressed. The elastic and inelastic scattering
amplitudes show important medium modifications close to the kaon nucleon
threshold. We also construct the $K^-$-nuclear optical potential appropriate
for $K^-$ atoms. Our microscopic approach predicts a strong attractive
non-local interaction strength.",9802033v2
1998-05-05,Chiral Dynamics of Low-Energy Kaon-Baryon Interactions with Explicit Resonance,"The processes involving low energy $\bar{K}N$ and $Y\pi$ interactions (where
$Y= \Sigma$ or $\Lambda$) are studied in the framework of heavy baryon chiral
perturbation theory with the $\Lambda$(1405) resonance appearing as an
independent field.
  The leading and next-to-leading terms in the chiral expansion are taken into
account. We show that an approach which explicitly includes the $\Lambda$(1405)
resonance as an elementary quantum field gives reasonable descriptions of both
the threshold branching ratios and the energy dependence of total cross
sections.",9805011v1
1998-09-01,Nonlinear dynamics of giant resonances in atomic nuclei,"The dynamics of monopole giant resonances in nuclei is analyzed in the
time-dependent relativistic mean-field model. The phase spaces of isoscalar and
isovector collective oscillations are reconstructed from the time-series of
dynamical variables that characterize the proton and neutron density
distributions. The analysis of the resulting recurrence plots and correlation
dimensions indicate regular motion for the isoscalar mode, and chaotic dynamics
for the isovector oscillations. Information-theoretic functionals identify and
quantify the nonlinear dynamics of giant resonances in quantum systems that
have spatial as well as temporal structure.",9809003v1
1998-09-11,Relativistic mean-field description of the dynamics of giant resonances,"The relativistic mean-field theory provides a framework in which the nuclear
many-body problem is described as a self-consistent system of nucleons and
mesons. In the mean-field approximation, the self-consistent time evolution of
the nuclear system describes the dynamics of collective motion: nuclear
compressibility from monopole resonances, regular and chaotic dynamics of
isoscalar and isovector collective vibrations.",9809036v1
1998-11-10,Resonant continuum in the Hartree-Fock+BCS approximation,"A method for incorporating the effect of the resonant continuum into
  Hartree-Fock+BCS equations is proposed. The method is applied for the case of
a neutron-rich nucleus calculated with a Skyrme-type force plus a zero-range
pairing interaction and the results are compared with
  Hartree-Fock-Bogoliubov calculations. It is shown that the widths of resonant
states have an important effect on the pairing properties of nuclei close to
the drip line.",9811037v2
1998-12-30,Two-photon processes in two-nucleon systems as a tool of searching for exotic six-quark resonances,"The reaction $pp \to pp2\gamma$, proposed earlier to probe for the
NN--decoupled dibaryon resonances, has been studied by the DIB$2\gamma$
Collaboration (JINR) and their preliminary data seem to give evidence for the
resonance effect at about 1920 MeV. We discuss some other two-photon processes:
the double radiative capture reaction in pionic deuterium, photoabsorption sum
rules and the nuclear Compton scattering, which we consider to be especially
feasible for further test and invesigation of possible low-lying, exotic
six-quark states.",9812077v2
1999-04-01,Evidence for the fourth P11 resonance predicted by the constituent quark model,"It is pointed out that the third of five low-lying P11 states predicted by a
constituent quark model can be identified with the third of four states in a
solution from a three-channel analysis by the Zagreb group. This is one of the
so-called ``missing'' resonances, predicted at 1880 MeV. The fit of the Zagreb
group to the pi N -> eta N data is the crucial element in finding this fourth
resonance in the P11 partial wave.",9904005v2
1999-07-15,Coherent pion electroproduction on the deuteron in the $Δ(1232)$ resonance region,"Coherent pion electroproduction on the deuteron is studied in the
$\Delta(1232)$ resonance region in the impulse approximation, i.e., neglecting
pion rescattering and two-body effects. The elementary reaction on the nucleon
is described in the framework of an effective Lagrangian approach including the
dominant $P_{33}(1232)$ resonance and the usual background terms of the Born
contributions for $\pi^0$ production. We have studied the influence of these
different contributions on the various structure functions which determine the
unpolarized exclusive differential cross section in a variety of kinematic
regions.",9907057v1
1999-08-16,Giant Resonances in Coulomb Excitations of Relativistic Ions,"We propose a soluble model to incorporate the nonlinear effects in the
transition probabilities of the multiphonon Giant Dipole Resonances based on
the SU(1,1) algebra. Analytical expressions for the multi-phonon transition
probabilities are derived. For reasonably small magnitude of nonlinearity
$x\simeq 0.1-0.2$ enhancement factor for the Double Giant Resonance excitation
probabilities and the cross sections %in relativistic ion collisions reaches
values $1.3-2$ compatible with experimental data.",9908051v1
1999-09-16,Isoscalar Giant Quadrupole Resonance State in the Relativistic Approach with the Momentum-Dependent Self-Energies,"We study the excited energy of the isoscalar giant quadrupole resonance with
the scaling method in the relativistic many-body framework. In this calculation
we introduce the momentum-dependent parts of the Dirac self-energies arising
from the one-pion exchange on the assumption of the pseudo-vector coupling with
nucleon field. It is shown that this momentum-dependence enhances the Landau
mass significantly and thus suppresses the quadrupole resonance energy even
giving the small Dirac effective mass which causes a problem in the
momentum-independent mean-field theory.",9909037v1
2000-07-05,Relevant polarization observables for the study of the Roper resonance with hadronic probes,"The purpose of this contribution is to stress the great importance of
polarization observables for the study of nucleon resonances, in particular in
the case of deuteron and proton probes. Polarization observables play a unique
role in signing the reaction mechanism and bring new information in the
microscopic description of baryon resonances. We will calculate the relevant
polarization observables, for $p+d$- and $p+\alpha$-collisions, in case of
inclusive reactions and for some selected exclusive channels.",0007006v1
2000-08-11,Missing Nucleon Resonances in Kaon Production with Pions and Photons,"Resonances with strong couplings to strangeness channels are investigated in
a coupled-channels framework of kaon production with pions and photons. We find
evidence for an additional D13 resonance around 1900 MeV that has a significant
decay width into the K Lambda final state. Such a state has been predicted in a
relativistic quark model at 1960 MeV with significant gamma N and K Lambda
branching ratios.",0008024v1
2000-10-18,The NN Phase Shifts <3 GeV and Resonance Features,"Solutions SP00, SM00 and FA00 of nucleon-nucleon (NN) phase shift analyzes by
Arndt et al. are used in optical model studies. The partial waves, single
channels J.leq.7 and coupled channels J.leq.6, are scrutinized. The radial
probability distributions and losses of flux are used to identify the known
Delta and N* resonances as well as anticipated other structures. The energy
interval extends to 3 GeV.",0010058v1
2000-10-18,The GDH sum rule for the Delta isobar: A possible anomaly?,"The GDH sum rule is discussed for the Delta(1232) resonance. It is shown that
apart from ordinary excitations to higher-energy states, the sum rule contains
a large negative contribution due to de-excitation into the nucleon state.
Therefore, a fulfillment of the sum rule assumes a strong coupling of Delta^+
and Delta^0 to resonances of spin 5/2 and higher. Calculations performed in
quark models suggest that D15(1675) may be such a resonance. However, its
strength is found to be not sufficient for bringing the GDH sum rule to a
theoretically expected positive magnitude.",0010060v1
2000-11-29,Isoscalar Giant Dipole Resonance and Nuclear Matter Incompressibility Coefficient,"We present results of microscopic calculations of the strength function,
S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar
giant dipole resonance (ISGDR). An accurate and a general method to eliminate
the contributions of spurious state mixing is presented and used in the
calculations. Our results provide a resolution to the long standing problem
that the nuclear matter incompressibility coefficient, K, deduced from sigma(E)
data for the ISGDR is significantly smaller than that deduced from data for the
isoscalar giant monopole resonance (ISGMR).",0011098v1
2001-04-30,Mesons electromagnetic production study via a constituent quark approach,"Using a chiral constituent quark approach based on the broken SU(6) \otimes
O(3) symmetry, we focus on the spectroscopy of isospin-1/2 nucleonic
resonances. A model for the eta photoproduction, embodying all known nucleonic
resonances, shows clear need for a yet undiscovered S11 resonance, for which we
determine the mass (1.730 GeV) and the total width (180 MeV).",0104086v1
2001-06-28,Description of Double Giant Dipole Resonance within the Phonon Damping Model,"In a recent Letter [1] an overall agreement with the experimental data for
the excitation of the single and double giant dipole resonances in relativistic
heavy ion collision in 136Xe and 208Pb nuclei has been reported. We point out
that this agreement is achieved by a wrong calculation of the DGDR excitation
mechanism. We also argue that the agreement with the data for the widths of
resonances is achieved by an unrealistically large value of a model parameter.
  [1] Nguyen Dinh Dang, Vuong Kim Au, and Akito Arima, Phys. Rev. Lett. 85
(2000) 1827.",0106065v1
2001-07-11,Resonance lifetime in Boltzmann-Uehling-Uhlenbeck theory: observable consequences,"Within the transport BUU theory we study the influence of the choice for the
$\Delta$ resonance lifetime on pion-nucleus reactions and on heavy-ion
collisions at 1 A GeV. A quite small effect of these modifications on the pion
absorption on nuclei is found provided that the absorption probability of the
$\Delta$ resonance is modified consistently. Observable effects in the case of
heavy-ion collisions are demonstrated.",0107031v4
2002-01-08,Final state interactions in omega photoproduction near threshold,"Vector meson photoproduction and electroproduction have been suggested as a
tool to find or confirm the nucleon resonances. In order to extract more
reliable informations on the nucleon resonances, understanding the non-resonant
background is indispensable. We consider final state interactions in omega
photoproduction as a background production mechanism. For the intermediate
states, we consider nucleon--vector-meson and nucleon-pion channels. The role
of the final state interactions is discussed in omega meson photoproduction
near threshold.",0201016v1
2002-05-19,Effective Lagrangian approach to the omega meson photoproduction near threshold,"We apply the effective Lagrangian approach to investigate the role of the
nucleon resonances in $\omega$ meson photoproduction at energies near the
threshold. The resonant amplitudes are calculated from effective Lagrangians
with the gamma NN* and omega NN* coupling constants fixed by the empirical
helicity amplitudes and the vector meson dominance model. The contributions
from the nucleon resonances are found to be significant in changing the
differential cross sections in a wide interval of t and various spin
observables.",0205052v1
2002-08-26,Coupling of giant resonances to soft E1 and E2 modes in B-8,"The dynamic coupling between giant resonance states and ""soft"", low-energy
excitation, modes in weakly-bound nuclei is investigated. A coupled-channels
calculation is reported for the reaction 8B + Pb --> p + 7Be + Pb at 83
MeV/nucleon. It is shown that the low-energy response is only marginally
modified by transitions to the isovector giant dipole and isoscalar giant
quadrupole resonances.",0208054v1
2002-11-19,pi and rho loop corrections to omega photoproduction in the resonance region,"One-loop corrections due to the intermediate $\pi N$ and $\rho N$ states are
studied in $\omega$ photoproduction near threshold. Our results show that the
coupled-channel effects should be taken into account in extracting reliable
nucleon resonance parameters from the forthcoming vector meson photoproduction
data in the resonance region.",0211054v1
2002-11-25,Baryon Resonance Dynamics in pi N \to N V Reactions Near Threshold,"The rho - omega interference in the exclusive reaction pi N \to N' e+ e- is
studied within a schematic model including the established baryon resonances up
to 1720 MeV. Near threshold the interference can be used to separate the
isoscalar part of the electromagnetic current. The role of various baryon
resonances is highlighted.",0211078v1
2002-12-21,Statistical Hadronization probed by resonances,"We study to what extent a measurement of the $m_\bot$ spectra for hadrons and
their resonances can resolve ambiguities in statistical model description of
particle production. We describe in quantitative analysis how physical
assumptions about the freeze-out geometry and dynamics influence the particle
spectra. Considering ratios of $m_\bot$ distribution of resonance-particle
ratios (such as $K^*/K$, $\Sigma^*/\Lambda, \eta'/\eta$) we observe significant
sensitivity to fireball freeze-out geometry and flow dynamics.",0212091v4
2003-02-23,Vector meson production and nucleon resonance analysis in the Giessen coupled-channel model,"We present a nucleon resonance analysis by simultaneously considering all
pion- and photon-induced experimental data on the final states $\gamma N$, $\pi
N$, $2\pi N$, $\eta N$, $K\Lambda$, $K\Sigma$, and $\omega N$ for energies from
the nucleon mass up to $\sqrt s = 2$ GeV. In this analysis we find strong
evidence for various higher lying resonances as, e.g., the $P_{13}(1900)$. The
$\omega N$ production mechanism is dominated by large $P_{11}(1710)$ and
$P_{13}(1900)$ contributions.",0302067v1
2003-04-02,Narrow Resonances in Effective Field Theory,"We discuss the power counting for effective field theories with narrow
resonances near a two-body threshold. Close to threshold, the effective field
theory is perturbative and only one combination of coupling constants is
fine-tuned. In the vicinity of the resonance, a second, ``kinematic''
fine-tuning requires a nonperturbative resummation. We illustrate our results
in the case of nucleon-alpha scattering.",0304007v1
2003-04-28,On the Excitation of Double Giant Resonances in Heavy Ion Reactions,"The interplay of nuclear and Coulomb processes in the inelastic excitation of
single- and double-phonon giant resonances in heavy ion collisions is studied
within a simple reaction model. Predominance of the Coulomb excitation
mechanism on the population of the single-phonon and, on the contrary,
predominance of the nuclear excitation for the double-phonon is evidenced. The
effect of the spreading of the strength distribution of the giant resonances on
the excitation process is analyzed, showing sizeable modifications in the case
of Coulomb dominated processes.",0304081v1
2003-05-07,Latest results from lattice QCD for the Roper resonance,"The present status of the Roper resonance in lattice QCD is reviewed. Some of
the latest lattice results are discussed with particular emphasis on a large
systematic error stemming from the finite size effect. These results suggest
that the Roper resonance can be described by the simple three quark excitation
of sizable extent.",0305014v2
2003-05-30,On baryon resonances and chiral symmetry,"We study J^P=(3/2)^- baryon resonances as generated by chiral coupled-channel
dynamics. Parameter free results are obtained in terms of the Weinberg-Tomozawa
term predicting the leading s-wave interaction strength of Goldstone bosons
with baryon-decuplet states. In the 'heavy' SU(3) limit with m_\pi = m_K \sim
500 MeV the resonances turn into bound states forming a decuplet and octet
representation of the SU(3) group. Using physical masses the mass splitting are
remarkably close to the empirical pattern.",0305101v2
2003-06-05,In-medium modifications of the S11(1535) resonance and eta photoproduction,"We investigate the influence of possible in-medium modifications of the
S11(1535) in eta photoproduction in nuclei. Besides Fermi motion, Pauli
blocking and binding effects also collisional broadening is accounted for. The
in-medium width is obtained from a realistic resonance-hole model. Results on
eta photoproduction are obtained from a semi-classical BUU transport model and
compared with data. We find that calculations including a momentum dependent
nucleon and resonance potential are in agreement with the recent KEK data. In
contrast, collisional broadening has only little influence.",0306024v2
2003-07-21,Resonances and the thermonuclear reaction rate,"We present an approximate analytic expression for thermonuclear reaction rate
of charged particles when the cross section contains a single narrow or wide
resonance described by a Breit-Wigner shape. The resulting expression is
uniformly valid as the effective energy and resonance energy coalesce. We use
our expressions to calculate the reaction rate for
$^{12}$C(p,$\gamma$)$^{13}$N.",0307083v1
2003-10-06,Giant Resonances from TDHF,"A method of calculating giant resonance strength functions using
Time-Dependent Hartree-Fock techniques is described. An application to
isoscalar giant monopole resonances in spherical nuclei is made, thus allowing
a comparison between independent 1-, 2- and 3-Dimensional computer codes.",0310020v1
2004-10-01,Pionic atoms probing pi-NN resonances,"The pion optical potential generated by the hypothetical pi-NN-coupled
NN-decoupled dibaryon resonance d'(2065) is calculated to the lowest order in
nuclear matter density. The contribution to the pion optical potential is found
to be within the empirical errors, so the d'(2065) existence currently does not
contradict to the observed properties of the pi-nucleus bound states. Future
progress in the pionic X-ray spectroscopy can reveal contributions of pi-NN
resonances to energy levels and widths of the pionic atoms.",0410002v1
2004-11-10,Missing Resonances in Kaon Photoproduction on the Nucleon,"New kaon photoproduction data on a proton, gamma + p --> K+ + Lambda, are
analyzed using a multipole approach. The background terms are given in terms of
gauge invariant, crossing symmetric, Born diagrams with hadronic form factors,
while the resonances are parameterized using Breit-Wigner forms. Preliminary
results suggest a number of new resonances, as predicted by many quark model
studies. A comparison between the extracted multipoles and those obtained from
KAON-MAID is presented.",0411035v1
2004-11-18,Anatomy of three-body decay II. Decay mechanism and resonance structure,"We use the hyperspherical adiabatic expansion method to discuss the the two
mechanisms of sequential and direct three-body decay. Both short-range and
Coulomb interactions are included. Resonances are assumed initially populated
by a process independent of the subsequent decay. The lowest adiabatic
potentials describe the resonances rather accurately at distances smaller than
the outer turning point of the confining barrier. We illustrate with realistic
examples of nuclei from neutron ($^{6}$He) and proton ($^{17}$Ne) driplines as
well as excited states of beta-stable nuclei ($^{12}$C).",0411079v1
2004-12-21,Monopole and quadrupole polarization effects on the alpha-particle description of $^{8}$Be,"We investigate the effect of monopole and quadrupole modes on the elastic
alpha-alpha resonance structure of $^{8}$Be. To this end we make a fully
microscopic coupled channels calculation with three coupled channels, using the
Algebraic Model. The continuum spectrum and wave functions are analyzed in
terms of the individual channels to understand the nature of the resonances. It
is shown that both monopole and quadrupole modes have a non-negligible effect
on the resonances in the alpha-alpha continuum.",0412086v1
2005-04-12,Sum Rules of the Multiple Giant Dipole States,"Various sum rules for multiple giant dipole resonance states are derived. For
the triple giant dipole resonance states, the energy-weighted sum of the
transition strengths requires a model to be related to those of the single and
double giant dipole resonance states. It is also shown that the non-diagonal
matrix elements of the double commutator between the dipole operator and the
nuclear Hamiltonian give useful identities for the excitation energy and
transition strength of each excited state. Using those identities, the
relationship between width of the single dipole state and those of the multiple
ones is qualitatively discussed.",0504038v1
2005-07-08,Can realistic nuclear interactions tolerate a resonant tetraneutron ?,"The possible existence of four-neutron resonances close to the physical
energy region is explored. Faddeev-Yakubovsky equations have been solved in
configuration space using realistic nucleon-nucleon interaction models. Complex
Scaling and Analytical Continuation in the Coupling Constant methods were used
to follow the resonance pole trajectories, which emerge out of artificially
bound tetraneutron states. The final pole positions for four-neutron states lie
in the third energy quadrant with negative real energy parts and should thus
not be physically observable.",0507022v1
2006-03-08,Efimov effect in nuclear three-body resonance decays,"We investigate the effects of the nearly fulfilled Efimov conditions on the
properties of three-body resonances. Using the hyper-spheric adiabatic
expansion method we compute energy distributions of fragments in a three-body
decay of a nuclear resonance. As a realistic example we investigate the 1-
state in the halo nucleus 11Li within a three-body 9Li+n+n model.
Characteristic features appear as sharp peaks in the energy distributions.
Their origin, as in the Efimov effect, is in the large two-body s-wave
scattering lengths between the pairs of fragments.",0603023v1
2006-05-17,Propagation of broad meson resonances in a BUU type transport model: Application to di-electron production,"We apply a BUU type transport model for the interpretation of the di-electron
invariant mass spectrum measured by the HADES collaboration for the reaction
C(2 AGeV) + C. Our model incorporates the propagation of broad meson resonances
emerging from the decay of baryon resonances.",0605036v3
2006-08-26,Hadron Resonances and Phase Threshold in Heavy Ion Collisions,"We show that a measurement of the reaction energy dependence of relative
hadron resonance yields in heavy ion collisions can be used to study the phase
structure of the dense QCD matter created in these collisions, and investigate
the origin of the trends observed in the excitation functions of certain soft
hadronic observables. We show that presence of chemical nonequilibrium in light
quark abundance imparts a characteristic signature on the energy dependence of
resonance yields, that differs considerably from what is expected in the
equilibrium picture.",0608061v2
2006-09-19,Pion correlations in hydro-inspired models with resonances,"The effects of the freeze-out hypersurface and resonance decays on the pion
correlation functions in relativistic heavy-ion collisions are studied with
help of the hydro-inspired models with single freeze-out. The heavy-ion
Monte-Carlo generator THERMINATOR is used to generate hadronic events
describing production of particles from a thermalized and expanding source. We
find that the short-lived resonances increase the pionic HBT radii by about 1
fm. We also find that the pion HBT data from RHIC are fully compatible with the
single freeze-out scenario provided a special choice of the freeze-out
hypersurface is made.",0609054v1
2006-11-10,eta-photoproduction in the resonance energy region,"The $\eta$ production in the nucleon resonance energy region is studied
within the unitary coupled-channels effective Lagrangian approach of the
Giessen model. We demonstrate that the second peak recently observed in the
cross section of $\eta$ photoproduction on the neutron at $\sqrt{s}$=1.66 GeV
can be explained in terms of coupled-channel effects due to $S_{11}(1650)$ and
$P_{11}(1710)$ resonance excitations.",0611036v2
2006-12-05,Cluster structure of a low-energy resonance in tetraneutron,"We theoretically investigate the possibility for a tetraneutron to exist as a
low-energy resonance state. We explore a microscopic model based on the
assumption that the tetraneutron can be treated as a compound system where
$^3$n+n and $^2$n+$^2$n coupled cluster configurations coexist. The influence
of the Pauli principle on the kinetic energy of the relative motion of the
neutron clusters is shown to result in their attraction. The strength of such
attraction is high enough to ensure the existence of a low-energy resonance in
the tetraneutron, provided that the oscillator length is large enough.",0612020v1
2006-12-06,Decay Properties Of The Dipole Isobaric Analog Resonances,"A continuum-RPA-based approach is applied to describe the decay properties of
isolated dipole isobaric analog resonances in nuclei having not-too-large
neutron excess. Calculated for a few resonances in 90Zr the elastic
E1-radiative width and partial proton widths for decay into one-hole states of
89Y are compared with available experimental data.",0612028v1
2007-03-14,Nuclear Giant Resonances and Linear Response,"We search for nonlinear effects in nuclear giant resonances (GRs), in
particular the isovector dipole and the isoscalar quadrupole modes. To that
end, we employ a spectral analysis of time-dependent Hartree-Fock (TDHF)
dynamics using Skyrme forces. Based on TDHF calculations over a wide range of
excitation amplitudes, we explore the collectivity and degree of harmonic
motion in these modes. Both GR modes turn out to be highly harmonic in heavy
nuclei from A=100 on. There is no trace of a transition to irregular motion and
multiple resonances are predicted. Slight anharmonicities are seen for light
nuclei, particularly for $^{16}$O. These are mainly caused by the spin-orbit
splitting.",0703044v1
1999-05-20,Resonance phenomena of a solitonlike extended object in a bistable potential,"We investigate the dynamics of a soliton that behaves as an extended
particle. The soliton motion in an effective bistable potential can be chaotic
in a similar way as the Duffing oscillator. We generalize the concept of
geometrical resonance to spatiotemporal systems and apply it to design a
nonfeedback mechanism of chaos control using localized perturbations.We show
the existence of solitonic stochastic resonance.",9905004v1
1998-01-28,Resonant Above-Threshold Ionization Peaks at Quantized Intensities,"We suggest that electron-laser interactions can give rise to resonance
phenomena as the intensity varies. A new QED perturbation theory is developed,
in which the coupling between an electron and the second quantized laser mode
is treated nonperturbatively. We predict, for example, the above-threshold
ionization rate shows peaks at intensities with integer ponderomotive
parameter. Such quantum resonance effects may be exploited to calibrate laser
intensities in appropriate range.",9801030v1
1998-05-23,Optical microsphere resonators: optimal coupling to high-Q whispering gallery modes,"A general model is presented for coupling of high-$Q$ whispering-gallery
modes in optical microsphere resonators with coupler devices possessing
discrete and continuous spectrum of propagating modes. By contrast to
conventional high-Q optical cavities, in microspheres independence of high
intrinsic quality-factor and controllable parameters of coupling via evanescent
field offer variety of regimes earlier available in RF devices. The theory is
applied to the earlier-reported data on different types of couplers to
microsphere resonators and complemented by experimental demonstration of
enhanced coupling efficiency (about 80%) and variable loading regimes with
Q>10^8 fused silica microspheres.",9805030v1
1998-08-24,Solitary Waves on a Coasting High-Energy Stored Beam,"In this work we derive evolution equations for the nonlinear behavior of a
coasting beam under the influence of a resonator impedance. Using a
renormalization group approach we find a set of coupled nonlinear equations for
the beam density and the resonator voltage. Under certain conditions, these may
be analytically solved yielding solitary wave behavior, even in the presence of
significant dissipation in the resonator. We find long-lived perturbations,
i.e. droplets, which separate from the beam and decelerate towards a
quasi-equilibrium state, in good agreement with simulation results.",9808032v1
1998-09-11,Formation of Patterns and Coherent Structures in Charged Particle Beams,"In the present paper we study the long wavelength and slow time scale
behavior of a coasting beam in a resonator adopting a broad-band impedance
model. Based on the renormalization group approach we derive a set of coupled
evolution equations for the beam envelope distribution function and the
resonator voltage amplitude. The equation for the resonator voltage amplitude
is further transformed into a generalized Ginzburg-Landau equation.",9809018v1
1998-10-12,Markov analysis of stochastic resonance in a periodically driven integrate-fire neuron,"We model the dynamics of the leaky integrate-fire neuron under periodic
stimulation as a Markov process with respect to the stimulus phase. This avoids
the unrealistic assumption of a stimulus reset after each spike made in earlier
work and thus solves the long-standing reset problem. The neuron exhibits
stochastic resonance, both with respect to input noise intensity and stimulus
frequency. The latter resonance arises by matching the stimulus frequency to
the refractory time of the neuron. The Markov approach can be generalized to
other periodically driven stochastic processes containing a reset mechanism.",9810019v1
1998-10-18,Simulation and analysis of electron cyclotron resonance discharges,"We describe in detail the method for Particle-in cell/Monte-Carlo simulation
of electron cyclotron resonance (ECR) discharges. In the simulation, electric
and magnetic fields are obtained by solving Maxwell equations, and electrons
and ions are accelerated by solving equations of motion. We consider two
different cases: (i) propagation of electromagnetic wave in the presence of a
constant external magnetic field; (ii) propagation of electromagnetic wave in
the presence of a linearly decreasing magnetic field which corresponds to a
realistic ECR discharge. The simulation results indicate that at the resonance
layer, the electrons are heated by the electromagnetic wave, and the incoming
wave amplitude is pronouncedly damped, with the wave hardly propagating through
the ECR layer.",9810033v1
1999-01-13,How harmonic is dipole resonance of metal clusters?,"We discuss the degree of anharmonicity of dipole plasmon resonances in metal
clusters. We employ the time-dependent variational principle and show that the
relative shift of the second phonon scales as $N^{-4/3}$ in energy, $N$ being
the number of particles. This scaling property coincides with that for nuclear
giant resonances. Contrary to the previous study based on the boson-expansion
method, the deviation from the harmonic limit is found to be almost negligible
for Na clusters, the result being consistent with the recent experimental
observation.",9901016v1
1999-04-12,Fermi resonance-algebraic model for molecular vibrational spectra,"A Fermi resonance-algebraic model is proposed for molecular vibrations, where
a U(2) algebra is used for describing the vibrations of each bond, and Fermi
resonances between stretching and bending modes are taken into account. The
model for a bent molecule XY_2 and a molecule XY_3 is successfully applied to
fit the recently observed vibrational spectrum of the water molecule and arsine
(AsH_3), respectively, and results are compared with those of other models.
Calculations show that algebraic approaches can be used as an effective method
for describing molecular vibrations with small standard deviations.",9904020v1
1999-05-07,Single and Double Resonance Microwave Spectroscopy in Superfluid $^4$He Clusters,"Purely rotational transitions of a molecule, such as HCCCN, embedded in large
$^4$He clusters have been detected for the first time. The saturation behavior
shows that, in contrast to previous expectations, the microwave line profiles
are dominated by inhomogeneous broadening mechanisms. Spectral holes and peaks
produced by microwave-microwave double resonance have widths comparable to
those of single resonance lines, indicating that relaxation occurs among
quantum states of the inhomogeneous distribution of each rotational level, at a
rate approximately 10 times faster than rotationally inelastic relaxation.",9905022v2
1999-06-28,Resonant Diffraction Radiation from an Ultrarelativistic Particle Moving Close to a Tilted Grating,"A simple model for calculating the diffraction radiation characteristics from
an ultrarelativistic charged particle moving close to a tilted ideally
conducting strip is developed. Resonant diffraction radiation (RDR) is treated
as a superposition of the radiation fields for periodically spaced strips. The
RDR characteristics have been calculated as a function of the number of grating
elements, tilted angle, and initial particle energy. An analogy with both the
resonant transition radiation in absorbing medium and the parametric X-ray
radiation is noted.",9906054v3
1999-09-21,Qualitative analysis of low-lying resonances of the dipositronium emerging from Ps-Ps and Ps-Ps* collisions,"An analysis of the channel wave functions is made to clarify the types of
resonance emerging from Ps-Ps and Ps-Ps* collisions. The ordering of the energy
levels of the states of the dipositronium is evaluated based on the inherent
nodal structures of wave functions and on existing theoretical results. A few
very probable low-lying narrower resonances, namely the 0+(A2), 1-(E),...,
benefiting from the centrifugal barrier have been proposed.",9909041v1
2000-04-28,Stochastic Resonance in Neuron Models: Endogenous Stimulation Revisited,"The paradigm of stochastic resonance (SR)---the idea that signal detection
and transmission may benefit from noise---has met with great interest in both
physics and the neurosciences. We investigate here the consequences of reducing
the dynamics of a periodically driven neuron to a renewal process (stimulation
with reset or endogenous stimulation). This greatly simplifies the mathematical
analysis, but we show that stochastic resonance as reported earlier occurs in
this model only as a consequence of the reduced dynamics.",0004075v3
2000-05-09,Coherent transients in optical lattices,"We use a method based on optical coherent transients to study the vibrational
coherence lifetimes of atoms trapped in the potential wells of a near-resonant
optical lattice in the oscillating regime. The dependence of the positions and
widths of the vibrational Raman resonances of the coherent transient spectra on
the intensity, detuning, and geometry of the lattice beams is investigated and
the results are compared with theoretical predictions. It is shown that the
principal source of broadening of the vibrational Raman resonances is the
anharmonicity of the light-shift potential wells. We also perform time-resolved
measurements of the vibrational excitation of atoms equilibrating in an optical
lattice.",0005020v1
2000-07-26,Strong Discontinuities in the Complex Photonic Band Structure of Transmission Metallic Gratings,"Complex photonic band structures (CPBS) of transmission metallic gratings
with rectangular slits are shown to exhibit strong discontinuities that are not
evidenced in the usual energetic band structures. These discontinuities are
located on Wood's anomalies and reveal unambiguously two different types of
resonances, which are identified as horizontal and vertical surface-plasmon
resonances. Spectral position and width of peaks in the transmission spectrum
can be directly extracted from CPBS for both kinds of resonances.",0007082v1
2001-05-11,Observation of coherent transients in ultrashort chirped excitation of an undamped two-level system,"The effects of Coherent excitation of a two level system with a linearly
chirped pulse are studied theoretically and experimentally (in Rb (5s - 5p)) in
the low field regime. The Coherent Transients are measured directly on the
excited state population on an ultrashort time scale. A sharp step corresponds
to the passage through resonance. It is followed by oscillations resulting from
interferences between off-resonant and resonant contributions. We finally show
the equivalence between this experiment and Fresnel diffraction by a sharp
edge.",0105032v1
2001-11-02,Statistical Properties of Fano Resonances in Atomic and Molecular Photoabsorption,"Statistical properties of Fano resonances occurring in photoabsorption to
highly excited atomic or molecular states are derived. The situation with one
open and one closed channel is analyzed when the classical motion of the
excited complex in the closed channel is chaotic. The closed channel subspace
is modeled by random matrix theory. The probability distribution of the Fano
parameter is derived both for the case of time reversal symmetry (TRS) and
broken time reversal symmetry. For the TRS case the area distribution under a
resonance profile relevant for low resolution experiments is discussed in
detail.",0111004v1
2001-11-15,Numerical studies of left-handed materials and arrays of split ring resonators,"We present numerical results on the transmission properties of the
left-handed materials (LHM) and split-ring resonators (SRR). The simulation
resultsare in qualitative agreement with experiments. The dependence of the
transmission through LHM on the real and imaginary part of the electric
permittivity of the metal, the length of the system, and the size of the unit
cell are presented. We also study the dependence of the resonance frequency of
the array of SRR on the ring thickness, inner diameter, radial and azimuthal
gap, as well as on the electrical permittivity of the board and the embedding
medium, where SRR resides. Qualitatively good agreement with previously
published analytical results is obtained.",0111135v1
2002-02-27,Brillouin propagation modes in optical lattices: interpretation in terms of nonconventional stochastic resonance,"We report the first direct observation of Brillouin-like propagation modes in
a dissipative periodic optical lattice. This has been done by observing, in
both theoretical and experimental work, a resonant behaviour of the spatial
diffusion coefficient in the direction corresponding to the propagation mode
with the phase velocity of the moving intensity modulation used to excite these
propagation modes. Furthermore, we show theoretically that the amplitude of the
Brillouin mode is a nonmonotonic function of the strength of the noise
corresponding to the optical pumping, and discuss this behaviour in terms of
nonconventional stochastic resonance.",0202067v1
2002-04-19,Frequency locking of tunable diode lasers to a stabilized ring-cavity resonator,"We demonstrate a technique for locking the frequency of a tunable diode laser
to a ring-cavity resonator. The resonator is stabilized to a diode laser which
is in turn locked to an atomic transition, thus giving it absolute frequency
calibration. The ring-cavity design has the principal advantage that there is
no feedback destabilization of the laser. The cavity has a free-spectral range
of 1.3 GHz and $Q$ of about 35, which gives robust locking of the laser. The
locked laser is able to track large scans of the cavity.",0204058v1
2002-07-25,Collision rates in near-resonant optical lattices,"We present a simple method to calculate the binary collision rate between
atoms in near-resonant optical lattices. The method is based on the Monte Carlo
wave function simulations and the collision rate is obtained by monitoring the
quantum flux beyond the average distance between the atoms. To illustrate the
usefulness of the method, we calculate the collision rates for a wide range of
occupation densities and various modulation depths of the lattice. The method
presented here combined with the semiclassical calculations accounting for
intra-well collisions can simplify the study of the effects of binary
collisions on the dynamics of atomic clouds trapped in near-resonant optical
lattices.",0207105v1
2002-10-31,Tree-body loss of of trapped ultracold $^{87}$Rb atoms due to a Feshbach resonance,"The loss of ultracold trapped atoms in the vicinity of a Feshbach resonance
is treated as a two-stage reaction, using the Breit-Wigner theory. The first
stage is the formation of a resonant diatomic molecule, and the second one is
its deactivation by inelastic collisions with other atoms. This model is
applied to the analysis of recent experiments on $^{87}$Rb, leading to an
estimated value of $7\times 10^{-11}$ cm$^{3}/$s for the deactivation rate
coefficient.",0211002v2
2003-05-27,Effects of boundary roughness on a Q-factor of whispering-gallery-mode lasing microdisk cavities,"We perform numerical studies of the effect of sidewall imperfections on the
resonant state broadening of the optical microdisk cavities for lasing
applications. We demonstrate that even small edge roughness causes a drastic
degradation of high-Q whispering gallery (WG) mode resonances reducing their
Q-values by many orders of magnitude. At the same time, low-Q WG resonances are
rather insensitive to the surface roughness. The results of numerical
simulation obtained using the scattering matrix technique, are analyzed and
explained in terms of wave reflection at a curved dielectric interface combined
with the examination of Poincare surface of sections in the classical ray
picture.",0305111v1
2003-07-18,Saturated-absorption spectroscopy: Eliminating crossover resonances using co-propagating beams,"We demonstrate a new technique for saturated-absorption spectroscopy using
co-propagating beams that does not have the problem of crossover resonances.
The pump beam is locked to a transition and its absorption signal is monitored
while the probe beam is scanned. As the probe comes into resonance with another
transition, the pump absorption is reduced and the signal shows a Doppler-free
dip. We use this technique to measure hyperfine intervals in the $D_2$ line of
$^{85}$Rb with a precision of 70 kHz, and to resolve hyperfine levels in the
$D_2$ line of $^{39}$K that are less than 10 MHz apart.",0307095v1
2003-08-27,Decay of the monochromatic capillary wave,"It was demonstrated by direct numerical simulation that, in the case of
weakly nonlinear capillary waves, one can get resonant waves interaction on the
discrete grid when resonant conditions are never fulfilled exactly. The waves's
decay pattern was obtained. The influence of the mismatch of resonant condition
was studied as well.",0308100v1
2003-09-25,"Lowest Open Channels, Bound States, and Narrow Resonances of Dipositronium","The constraints imposed by symmetry on the open channels of dipositronium has
been studied, and the symmetry-adapted lowest open channel of each quantum
state has been identified. Based on this study, the existence of two more 0^+
bound states has been theoretically confirmed, and a 0^+ narrow resonance has
been predicted. A variational calculation has been performed to evaluate the
critical strength of the repulsive interaction . Two 0^- states are found to
have their critical strengths very close to 1, they are considered as
candidates of new narrow resonances or loosely bound states .",0309105v1
2003-10-20,Nonlinear resonant wave interaction in vacuum,"The basic equations governing propagation of electromagnetic and
gravitational waves in vacuum are nonlinear. As a consequence photon-photon
interaction as well as photon-graviton interaction can take place without a
medium. However, resonant interaction between less than four waves cannot occur
in vacuum, unless the interaction takes place in a bounded region, such as a
cavity or a waveguide. Recent results concerning resonant wave interaction in
bounded vacuum regions are reviewed and extended.",0310095v1
2004-01-12,Fano-type interpretation of red shifts and red tails in hole array transmission spectra,"We present a unifying point of view which allows to understand spectral
features reported in recent experiments with two-dimensional arrays of
subwavelength holes in metal films. We develop a Fano analysis of the related
scattering problem by distinguishing two interfering contributions to the
transmission process, namely a non-resonant contribution (direct scattering)
and a resonant contribution (surface plasmon excitation). The introduction of a
coupling strength between these two contributions naturally induces resonance
shifts and asymmetry of profiles which satisfy simple scaling relations. We
also report an experiment to confirm this analysis.",0401054v1
2004-04-12,Influence of ambipolar potential on the properties of inductively coupled discharges at the bounce resonance condition,"The importance of accounting for an ambipolar electrostatic potential or a
non-uniform density profile for modelling of inductively coupled discharges is
demonstrated. A drastic enhancement is observed of the power transfer into
plasma for low-collisional, low-pressure, non-local discharges with non-uniform
electron density profiles under the condition of bounce resonance. This
enhanced plasma heating is attributed to the increase of the number of resonant
electrons, for which the bounce frequency inside the potential well is equal to
the rf field frequency.",0404060v1
2004-04-15,Modulation induced frequency shifts in a CPT-based atomic clock,"We investigate systematic errors associated with a common modulation
technique used for phase sensitive detection of a coherent population trapping
(CPT) resonance. In particular, we show that modification of the CPT resonance
lineshape due to the presence of off-resonant fields leads to frequency shifts
which may limit the stability of CPT-based atomic clocks. We also demonstrate
that an alternative demodulation technique greatly reduces these effects.",0404076v1
2004-04-26,Velocity-selective resonance dips in the probe absorption spectra of Rb D2 transitions induced by a pump laser,"We report experimental observation of velocity-selective resonances in the
Doppler-broadened probe absorption spectra of 85Rb and 87Rb D2 transitions in
the presence of a strong copropagating pump laser locked to a frequency within
the Doppler profile of the transition. The set of three dips having the
separation of allowed hyperfine transitions can be moved along the Doppler
profile by tuning the pump laser frequency indicating a resonance between the
pump laser frequency and the velocity shifted probe laser frequency.",0404120v1
2004-06-07,Efficient excitation of cavity resonances of subwavelength metallic gratings,"One dimensional rectangular metallic gratings enable enhanced transmission of
light for specific resonance frequencies. Two kinds of modes participating to
enhanced transmission have already been demonstrated : (i) waveguide modes and
(ii) surface plasmon polaritons (SPP). Since the original paper of Hessel and
Oliner \cite{hessel} pointing out the existence of (i), no progress was made in
their understanding. We present here a carefull analysis, and show that the
coupling between the light and such resonances can be tremendously improved
using an {\it evanescent} wave. This leads to enhanced localisation of light in
cavities, yielding, in particular, to a very selective light transmission
through these gratings.",0406028v1
2004-07-29,The resonant behaviour of the Faraday rotation in a medium with linear birefringence,"It is shown that the monochromatic optical wave propagating through the
medium with linear birefringence in presence of a signal electromagnetic wave
(whose wavelength is equal to the polarization beats length), displays Faraday
rotation having the frequency of the signal wave and unsuppressed by linear
birefringence. The effect is resonant with respect to the frequency of a signal
wave. The ""sharpness"" of the resonance is defined by length of the birefringent
medium.",0407142v1
2004-09-14,Annular Bragg Defect mode Resonators,"We propose and analyze a new type of a resonator in an annular geometry which
is based on a single defect surrounded by radial Bragg reflectors on both
sides. We show that the conditions for efficient mode confinement are different
from those of the conventional Bragg waveguiding in a rectangular geometry. A
simple and intuitive approach to the design of optimal radial Bragg reflectors
is proposed and employed, yielding chirped gratings. Small bending radii and
strong control over the resonator dispersion are possible by the Bragg
confinement. A design compromise between large Free Spectral Range (FSR)
requirements and fabrication tolerances is suggested.",0409067v1
2004-09-14,Low Threshold Two-Dimensional Annular Bragg Lasers,"Lasing at telecommunication wavelengths from annular resonators employing
radial Bragg reflectors is demonstrated at room temperature under pulsed
optical pumping. Sub milliwatt pump threshold levels are observed for
resonators with 0.5-1.5 wavelengths wide defects of radii 7-8 mm. The quality
factors of the resonator modal fields are estimated to be on the order of a few
thousands. The electromagnetic field is shown to be guided by the defect. Good
agreement is found between the measured and calculated spectrum.",0409068v1
2004-11-10,Mechanical Resonance of embedded cluster,"Embedded clusters, which are embedded in bulk materials and different from
the surroundings in structures, should be common in materials. This paper
studies resonance of such clusters. This work is stimulated by a recent
experimental observation that some localized clusters behavior like fluid at
the mesoscopic scale in many solid materials [Science in China(Series B). 46,
176 (2003)]. We argue that the phenomenon is just a vivid illustration of
resonance of embedded clusters, driven by ubiquitous microwaves. Because the
underlying mechanism is fundamental and embedded structures are usual, the
phenomenon would have great significance in material physics.",0411106v1
2004-11-24,Shape resonances in nested diffraction gratings,"The diffraction problem of a plane wave impinging on a grating formed by
nested cavities is solved by means of the modal method, for $s$ and $p$
polarization modes. The cavities are formed by perfectly conducting sheets that
describe rectangular profiles. The electromagnetic response of the grating is
analyzed, paying particular attention to the generation of resonances within
the structure. The dependence of the resonances on the geometrical parameters
of the grating is studied, and results of far and near field are shown. The
results are checked and compared with those available in the literature for
certain limit cases.",0411223v1
2004-12-17,Optical tuning of the scattering length of cold alkaline earth atoms,"It is possible to tune the scattering length for the collision of ultra-cold
1S0 ground state alkaline-earth atoms using an optical Feshbach resonance. This
is achieved with a laser far detuned from an excited molecular level near the
frequency of the atomic intercombination 1S0--3P1 transition. Simple resonant
scattering theory, illustrated by the example of 40Ca, allows an estimate of
the magnitude of the effect. Unlike alkali metal species, large changes of the
scattering length are possible while atom loss remains small, because of the
very narrow line width of the molecular photoassociation transition. This
raises prospects for control of atomic interactions for a system without
magnetically tunable Feshbach resonance levels.",0412111v1
2005-01-18,A novel absorption resonance for all-optical atomic clocks,"We report an experimental study of an all-optical three-photon-absorption
resonance (known as a ""N-resonance"") and discuss its potential application as
an alternative to atomic clocks based on coherent population trapping (CPT). We
present measurements of the N-resonance contrast, width and light-shift for the
D1 line of 87Rb with varying buffer gases, and find good agreement with an
analytical model of this novel resonance. The results suggest that N-resonances
are promising for atomic clock applications.",0501090v1
2005-03-31,High-contrast dark resonance on the D2 - line of 87Rb in a vapor cell with different directions of the pump - probe waves,"We propose a novel method enabling to create a high-contrast dark resonance
in the 87Rb vapor D2-line. The method is based on an optical pumping of atoms
into the working states by a two-frequency, linearly-polarized laser radiation
propagating perpendicularly to the probe field. This new scheme is compared to
the traditional scheme involving the circularly-polarized probe beam only, and
significant improvement of the dark resonance parameters is found. Qualitative
considerations are confirmed by numerical calculations.",0503246v2
2005-04-01,Modeling of a Resonant Tunneling Diode Optical Modulator,"The integration of a double barrier resonant tunneling diode within a
unipolar optical waveguide provides electrical gain over a wide bandwidth. Due
to the non-linearities introduced by the double barrier resonant tunneling
diode an unipolar InGaAlAs/InP optical waveguide can be employed both as
optical modulator and optical detector. The modeling results of a device
operating as optical modulator agree with preliminary experimental data,
foreseeing for an optimized device modulation depths up to 23 dB with chirp
parameter between -1 and 0 in the wavelength range analyzed (1520 nm - 1600
nm).",0504006v1
2005-06-01,Multi-electron giant dipole resonances of atoms in crossed electric and magnetic fields,"Multi-electron giant dipole resonances of atoms in crossed electric and
magnetic fields are investigated. Stationary configurations corresponding to a
highly symmetric arrangement of the electrons on a decentered circle are
derived, and a normal-mode stability analysis is performed. A classification of
the various modes, which are dominated either by the magnetic or Coulomb
interactions, is provided. A six-dimensional wave-packet dynamical study, based
on the MCTDH approach, is accomplished for the two-electron resonances,
yielding in particular lifetimes of more than 0.1 $\mu$s for strong electric
fields.",0506007v1
2005-07-10,Stochastic resonance in the growth of a tumor induced by correlated noises,"Multiplicative noise is found to divide the growth law of tumors into two
parts in a logistic model, which is driven by additive and multiplicative
noises simultaneously. The Fokker-Planck equation was also derived to explain
the fact that the influence of the intensity of multiplicative noise on the
growth of tumor cells has a stochastic resonance-like characteristic. An
appropriate intensity of multiplicative noise is benefit to the growth of the
tumor cells. The correlation between two sorts of noises weakens the stochastic
resonance-like characteristic. Homologous noises promote the growth of the
tumor cells.",0507070v2
2005-07-16,Low energy electron scattering from DNA and RNA bases: shape resonances and radiation damage,"Calculations are carried out to determine elastic scattering cross sections
and resonance energies for low energy electron impact on uracil and on each of
the DNA bases (thymine, cytosine, adenine, guanine), for isolated molecules in
their equilibrium geometry. Our calculations are compared with available theory
and experiment. We also attempt to correlate this information with experimental
dissociation patterns through an analysis of the temporary anion structures
that are formed by electron capture in shape resonances.",0507128v1
2005-09-28,Near-field enhancement and imaging in double cylindrical polariton-resonant structures: Enlarging perfect lens,"We experimentally demonstrate a prototype of a cylindrical enlarging lens
capable of enhancing and restoring evanescent fields. The enabling phenomenon
is the resonant excitation of coupled surface modes in a system of two
cylindrical arrays of small resonant particles. As was shown in [J. Appl. Phys.
96, 1293 (2004)], this phenomenon in planar arrays can be used in
electromagnetic near-field imaging. Here, we use a similar structure in a
cylindrically symmetric configuration, which gives us a possibility to obtain
an enlarged near-field image.",0509232v1
2005-12-23,Induced radiation processes in single-bubble sonoluminescence,"According to the recent revision of the theory of thermal radiation, thermal
black-body radiation has an induced origin. We show that in single-bubble
sonoluminescence thermal radiation is emitted by a spherical resonator,
coincident with the sonoluminescing bubble itself, instead of the ensemble of
elementary resonators emitting thermal black-body radiation in the case of open
gaseous media. For a given wavelength, the diameter of the resonator is fixed,
and this explains the very high constancy in phase of light flashes from the
sonoluminesing bubble, which is better than the constancy of period of a
driving acoustic wave.",0512228v1
2005-12-31,Enhancement and suppression of surface plasmon resonance in Ag aggregate by optical gain and absorption in surrounding dielectric medium,"We have observed the compensation of loss in metal by gain in interfacing
dielectric in the mixture of aggregated silver nanoparticles and rhodamine 6G
dye. The demonstrated six-fold enhancement of the Rayleigh scattering is the
evidence of the increase of the quality factor of the surface plasmon (SP)
resonance. The reported experimental observation paves the road to many
practical applications of nanoplasmonics. We have also predicted and
experimentally observed a suppression of the surface SP resonance in metallic
nanoparticles embedded in a dielectric host with absorption.",0601001v1
2006-03-06,Dipole blockade through Rydberg Forster resonance energy transfer,"High resolution laser excitation of np Rydberg states of cesium atoms shows a
dipole blockade at F\""{o}rster resonances corresponding to the resonant
dipole-dipole energy transfer of the np + np &#8594; ns + (n + 1)s reaction.
The dipole-dipole interaction can be tuned on and off by the Stark effect, and
such a process observed for relatively low n (25 &#8722; 41) is promising for
quantum gate devices. Both Penning ionization and saturation in the laser
excitation can limit the range of observation of the dipole blockade",0603038v2
2006-03-13,Mode coupling control in a resonant device: application to solid-state ring lasers,"A theoretical and experimental investigation of the effects of mode coupling
in a resonant macro- scopic quantum device is achieved in the case of a ring
laser. In particular, we show both analytically and experimentally that such a
device can be used as a rotation sensor provided the effects of mode coupling
are controlled, for example through the use of an additional coupling. A
possible general- ization of this example to the case of another resonant
macroscopic quantum device is discussed.",0603099v1
2006-05-26,Theory of double resonance magnetometers based on atomic alignment,"We present a theoretical study of the spectra produced by
optical-radio-frequency double resonance devices, in which resonant linearly
polarized light is used in the optical pumping and detection processes. We
extend previous work by presenting algebraic results which are valid for atomic
states with arbitrary angular momenta, arbitrary rf intensities, and arbitrary
geometries. The only restriction made is the assumption of low light intensity.
The results are discussed in view of their use in optical magnetometers.",0605234v2
2006-06-14,Controlling absorption resonances from sub-wavelength cylinder arrays,"The absorption and extinction spectra of sub-wavelength cylinder arrays are
shown to present two different kind of resonances. Close to the Rayleigh
anomalies, the diffractive coupling with the lattice periodicity leads to sharp
peaks in the extinction spectra with characteristic Fano line shapes for both s
and p-polarizations. When the material exhibits an absorption line or in the
presence of localized surface plasmon/polaritons, the system is shown to
present resonant absorption with wider and symmetric line shapes. For
s-polarization our analysis predicts a theoretical limit of 50 % of absorption.
Interestingly, for p-polarized light and an appropriate choice of parameters,
subwavelength cylinder arrays can present perfect (100 %) absorption.",0606119v1
2006-08-22,Fabrication of alignment structures for a fiber resonator by use of deep-ultraviolet lithography,"We present a novel method to mount and align an optical-fiber-based resonator
on the flat surface of an atom chip with ultrahigh precision. The structures
for mounting a pair of fibers, which constitute the fiber resonator, are
produced by a spin-coated SU-8 photoresist technique by use of deep-UV
lithography. The design and production of the SU-8 structures are discussed.
  From the measured finesses we calculate the coupling loss of the SU-8
structures acting as a kind of fiber splice to be smaller than 0.013 dB.",0608216v1
2006-09-12,Design of resonant microcavities: application to optical gyroscopes,"We study theoretically and numerically the effect of rotation on resonant
frequencies of microcavities in a rotating frame of reference. Cavity rotation
causes the shifts of the resonant frequencies proportional to the rotation rate
if it is larger than a certain value. Below the value, a region of rotation
rate exists where there is no resulting the frequency shifts proportional to
the rotation rate. We show that designing cavity symmetry as $C_{nv}$ ($n\ge
3$) can eliminate this region.",0609094v2
2006-10-03,Enhanced Transmission and Reflection of Femtosecond Pulses by a Single Slit,"We show that a physical mechanism responsible for the enhanced transmission
and reflection of femtosecond pulses by a single subwavelength nanoslit in a
thick metallic film is the Fabry-Perot-like resonant excitation of stationary,
quasistationary and nonstationary waves inside the slit, which leads to the
field enhancement inside and around the slit. The mechanism is universal for
any pulse-scatter system, which supports the stationary resonances. We point
out that there is a pulse duration limit below which the slit does not support
the intraslit resonance.",0610019v1
2006-10-11,Tunable plasma wave resonant detection of optical beating in high electron mobility transistor,"We report on tunable terahertz resonant detection of two 1.55 &micro;m
cw-lasers beating by plasma waves in AlGaAs/InGaAs/InP high-electron-mobility
transistor. We show that the fundamental plasma resonant frequency and its odd
harmonics can be tuned with the applied gate-voltage in the range 75-490 GHz.
The observed frequency dependence on gate-bias is found to be in good agreement
with the theoretical plasma waves dispersion law.",0610078v1
2006-11-26,Optical Magnetometry,"Some of the most sensitive methods of measuring magnetic fields utilize
interactions of resonant light with atomic vapor. Recent developments in this
vibrant field are improving magnetometers in many traditional areas such as
measurement of geomagnetic anomalies and magnetic fields in space, and are
opening the door to new ones, including, dynamical measurements of bio-magnetic
fields, detection of nuclear magnetic resonance (NMR), magnetic-resonance
imaging (MRI), inertial-rotation sensing, magnetic microscopy with cold atoms,
and tests of fundamental symmetries of Nature.",0611246v1
2004-04-19,Pulse-coupled resonate-and-fire models,"We analyze two pulse-coupled resonate-and-fire neurons. Numerical simulation
reveals that an anti-phase state is an attractor of this model. We can
analytically explain the stability of anti-phase states by means of a return
map of firing times, which we propose in this paper. The resultant stability
condition turns out to be quite simple. The phase diagram based on our theory
shows that there are two types of anti-phase states. One of these cannot be
seen in coupled integrate-and-fire models and is peculiar to resonate-and-fire
models. The results of our theory coincide with those of numerical simulations.",0404021v1
2006-01-12,Pure multiplicative stochastic resonance of anti-tumor model with seasonal modulability,"The effects of pure multiplicative noise on stochastic resonance in an
anti-tumor system modulated by a seasonal external field are investigated by
using theoretical analyses of the generalized potential and numerical
simulations. For optimally selected values of the multiplicative noise
intensity quasi-symmetry of two potential minima and stochastic resonance are
observed. Theoretical results and numerical simulations are in good
quantitative agreement.",0601016v1
1998-05-22,Quantum Logic Gates and Nuclear Magnetic Resonance Pulse Sequences,"We demonstrate how NMR can in principle be used to implement all the elements
required to build quantum computers, and briefly discuss the potential
applications of insights from quantum logic to the development of novel pulse
sequences with applications in more conventional NMR experiments.",9805070v1
1998-09-23,Interacting Dark Resonances: Interference Effects Induced by Coherently Altered Quantum Superpositions,"We predict the possibility of sharp, high-contrast resonances in the optical
response of a broad class of systems, wherein interference effects are
generated by coherent perturbation or interaction of dark states. The
properties of these resonances can be manipulated to design a desired atomic
response.",9809067v2
1999-01-14,Ultracold atoms interacting with a sinusoidal mode of a high-Q cavity,"We consider the interaction of two level ultracold atoms resonant with a
sinusoidal mode of the electromagnetic field in a high Q cavity. We found that
well resolved resonances appear in the transmission coefficients even for
actual interaction and cavity parameters. The probability of emission of one
photon and the probability of transmission of an atom, when a number of
coherent states is initially present in the cavity, are discussed. The
interplay between the increasing width of the resonances and multi-peak
steady-state photon-statistics is also studied. Furthermore, we compare our
results with those of a constant field mode.",9901032v1
1999-01-19,Effective mass in quantum effects of radiation pressure,"We study the quantum effects of radiation pressure in a high-finesse cavity
with a mirror coated on a mechanical resonator. We show that the optomechanical
coupling can be described by an effective susceptibility which takes into
account every acoustic modes of the resonator and their coupling to the light.
At low frequency this effective response is similar to a harmonic response with
an effective mass smaller than the total mass of the mirror. For a plano-convex
resonator the effective mass is related to the light spot size and becomes very
small for small optical waists, thus enhancing the quantum effects of
optomechanical coupling.",9901057v2
1999-06-23,Diffractive orbits in an open microwave billiard,"We demonstrate the existence and significance of diffractive orbits in an
open microwave billiard, both experimentally and theoretically. Orbits that
diffract off of a sharp edge strongly influence the conduction spectrum of this
resonator, especially in the regime where there are no stable classical orbits.
On resonance, the wavefunctions are influenced by both classical and
diffractive orbits. Off resonance, the wavefunctions are determined by the
constructive interference of multiple transient, nonperiodic orbits.
Experimental, numerical, and semiclassical results are presented.",9906087v1
1999-09-15,Repulsion of Resonance States and Exceptional Points,"Level repulsion is associated with exceptional points which are square root
singularities of the energies as functions of a (complex) interaction
parameter. This is also valid for resonance state energies. Using this concept
it is argued that level anti-crossing (crossing) must imply crossing
(anti-crossing) of the corresponding widths of the resonance states. Further,
itis shown that an encircling of an exceptional point induces a phase change of
one wave function but not of the other. An experimental setup is discussed
where this phase behaviour which differs from the one encountered at a diabolic
point can be observed.",9909047v1
2000-05-25,Inversionless amplification and laser-induced transparency at the discrete transitions and the transitions to continuum,"The effects of coherence of quantum transitions and the interference of
resonant nonlinear optical processes on the spectra of absorption,
amplification, and nonlinear-optical generation are considered. The most
favorable conditions are discussed for the inversionless amplification,
resonant refraction in the absence of absorption and for resonant enhancement
of nonlinear-optical generation at the discrete transitions and the transitions
to continuum.",0005108v1
2000-09-02,Remarks on the semi-classical theory of three state system,"The semi-classical solution of the three state system is considered to study
the population inversion at and away from resonance. At resonance, it is shown
that if the system is initially populated either in the upper or in the lower
level, then the population oscillation occurs in a way which is quite different
from that if it is initially populated in the middle state. At off resonance,
there is gradual suppression of the population in the excited states and in the
asymptotic limit of the detuning, the system returns to its initial state.",0009008v1
2001-03-03,Control of Non-Resonant Effects in a Nuclear Spin Quantum Computer with a Large Number of Qubits,"We discuss how to simulate simple quantum logic operations with a large
number of qubits. These simulations are needed for experimental testing of
scalable solid-state quantum computers. Quantum logic for remote qubits is
simulated in a spin chain. Analytical estimates are presented for possible
correlated errors caused by non-resonant transitions. A range of parameters is
given in which non-resonant effects can be minimized.",0103007v1
2001-06-25,Quantum Parametric Resonance,"The quantum mechanical equivalent of parametric resonance is studied. A
simple model of a periodically kicked harmonic oscillator is introduced which
can be solved exactly. Classically stable and unstable regions in parameter
space are shown to correspond to Floquet operators with qualitatively different
properties. Their eigenfunctions, which are calculated exactly, exhibit a
transition: for parameter values with classically stable solutions the
eigenstates are normalizable while they cannot be normalized for parameter
values with classically instable solutions. Similarly, the spectrum of quasi
energies undergoes a specific transition. These observations remain valid
qualitatively for arbitrary linear systems exhibiting classically parametric
resonance such as the paradigm example of a frequency modulated pendulum
described by Mathieu's equation.",0106138v1
2002-03-04,Stationary cantilever vibrations in the oscillating cantilever-driven adiabatic reversals -- magnetic resonance force microscopy technique,"We consider theoretically the novel technique in magnetic resonance force
microscopy which is called ``oscillating cantilever-driven adiabatic
reversals''. We present analytical and numerical analysis for the stationary
cantilever vibrations in this technique. For reasonable values of parameters we
estimate the resonant frequency shift as 6Hz per the Bohr magneton. We analyze
also the regime of small oscillations of the paramagnetic moment near the
transversal plane and the frequency shift of the damped cantilever vibrations.",0203013v1
2002-05-20,Stabilization of decaying states and quantum vortices,"A two-dimensional model of an electron moving under the influence of an
attractive zero-range potential as well as external magnetic and electric
fields is analyzed. We prove by numerical investigations that there are formed
such resonances which manifest a peculiar dependance on the electric field
intensity, i.e., although the electric field increases, the lifetime of these
resonance states grows up. It is explained that this phenomenon, called further
\textit{the stabilization}, is a close consequence of
\textit{quantum-mechanical vortices} induced by the magnetic field and
controlled by the electric field strength. In order to get more information
about these vortices the phase of wavefunctions as well as the probability
current for these stable resonances are investigated.",0205123v1
2002-10-26,The quantum mechanical geometric phase of a particle in a resonant vibrating cavity,"We study the general-setting quantum geometric phase acquired by a particle
in a vibrating cavity. Solving the two-level theory with the rotating-wave
approximation and the SU(2) method, we obtain analytic formulae that give
excellent descriptions of the geometric phase, energy, and wavefunction of the
resonating system. In particular, we observe a sudden $\pi$-jump in the
geometric phase when the system is in resonance. We found similar behaviors in
the geometric phase of a spin-1/2 particle in a rotating magnetic field, for
which we developed a geometrical model to help visualize its evolution.",0210182v1
2003-04-17,Efficient photon counting and single-photon generation using resonant nonlinear optics,"The behavior of an atomic double lambda system in the presence of a strong
off-resonant classical field and a few-photon resonant quantum field is
examined. It is shown that the system possesses properties that allow a
single-photon state to be distilled from a multi-photon input wave packet. In
addition, the system is also capable of functioning as an efficient
photodetector discriminating between one- and two-photon wave packets with
arbitrarily high efficiency.",0304121v1
2003-06-13,Strong two-photon emission by a medium with periodically time-dependent refractive index,"A two-photon emission of a medium with periodically time-dependent refractive
index is considered. The emission results from the zero-point fluctuations of
the medium. Usually this emission is very weak. However, it can be strongly
enhanced if the resonant condition $\omega_0$ = 2.94 $c/l_0$ is fulfilled (here
$\omega_0$ and $l_0 $ are the frequency and the amplitude of the oscillations
of the optical length of the medium, respectively). Besides, a medium with
resonant oscillations of the optical length performs the phase conjugated
reflection with high efficiency. A similar resonant enhancement of the
two-quantum emission of other bosons is also predicted.",0306095v1
2003-06-21,Nonlinear optics via double dark resonances,"Double dark resonances originate from a coherent perturbation of a system
displaying electromagnetically induced transparency. We experimentally show and
theoretically confirm that this leads to the possibility of extremely sharp
resonances prevailing even in the presence of considerable Doppler broadening.
A gas of 87Rb atoms is subjected to a strong drive laser and a weak probe laser
and a radio frequency field, where the magnetic coupling between the Zeeman
levels leads to nonlinear generation of a comb of sidebands.",0306147v1
2003-09-29,Synchronization of Hamiltonian motion and dissipative effects in optical lattices: Evidence for a stochastic resonance,"We theoretically study the influence of the noise strength on the excitation
of the Brillouin propagation modes in a dissipative optical lattice. We show
that the excitation has a resonant behavior for a specific amount of noise
corresponding to the precise synchronization of the Hamiltonian motion on the
optical potential surfaces and the dissipative effects associated with optical
pumping in the lattice. This corresponds to the phenomenon of stochastic
resonance. Our results are obtained by numerical simulations and correspond to
the analysis of microscopic quantities (atomic spatial distributions) as well
as macroscopic quantities (enhancement of spatial diffusion and pump-probe
spectra). We also present a simple analytical model in excellent agreement with
the simulations.",0309210v1
2003-12-03,Time of arrival with resonances: Beyond scattering states,"Assorted questions: Time as a parameter in Quantum Mechanics. No-Go theorems
for a time operator. Localization, time and causality. Causality violation.
Localization again. Lesson 1: Evading the troubles: Im E finite.
  Lights and shadows of a time operator:""Table-top Spacetime"" quantum
mechanics. Biphotons at Berkeley. Time operator build-up. Good news - bad news.
  Lesson 2: We need the resonances to tell one.",0312034v1
2004-01-07,Creation of atomic coherent superpositions in manifolds of levels without multi-photon resonance,"We propose a scheme for creating atomic coherent superpositions via
stimulated Raman adiabatic passage in a Lambda-type system where the final
state has twofold levels. In the employ of a control field, the presence of
double dark states leads to two arbitrary coherent superposition states with
equal amplitude but inverse relative phase without the condition of
multi-photon resonance. In particular, two orthogonal maximal coherent
superposition states are created when the control field is resonant with the
transition of the twofold levels. This scheme can also be extended to manifold
Lambda-type systems.",0401028v1
2004-01-24,Mechanism and Lineshapes of Sub-Fourier Resonances,"Subtle internal interference effects allow quantum-chaotic systems to display
""sub-Fourier"" resonances, i.e. to distinguish two neighboring driving
frequencies in a time shorter than the inverse of the difference of the two
frequencies. We report experiments on the atomic version of the kicked rotor
showing the unusual properties of the sub-Fourier resonances, and develop a
theoretical approach (based on the Floquet theorem) explaining these
properties, and correctly predicting the widths and lineshapes.",0401152v1
2004-04-13,Resonance-enhanced group delay times in an asymmetric single quantum barrier,"It is shown that the transmission and reflection group delay times in an
asymmetric single quantum barrier are greatly enhanced by the transmission
resonance when the energy of incident particles is larger than the height of
the barrier. The resonant transmission group delay is of the order of the
quasibound state lifetime in the barrier region. The reflection group delay can
be either positive or negative, depending on the relative height of the
potential energies on the two sides of the barrier. Its magnitude is much
larger than the quasibound state lifetime. These predictions have been observed
in a microwave experiment by H. Spieker of Braunschweig University.",0404080v2
2004-08-06,Light slowdown in the vicinity of cross-over resonances,"Pulse propagation is considered in an inhomogeneously broadened medium of
three-level atoms in a V-configuration, dressed by a counter-propagating pump
pulse. A significant signal slowdown is demonstrated in this of the three
frequency windows of a reduced absorption and a steep normal dispersion, which
is due to a cross-over resonance. Particular properties of the group index in
the vicinity of such a resonance are demonstrated in the case of closely spaced
upper levels.",0408044v1
2004-08-27,Resonances and adiabatic invariance in classical and quantum scattering theory,"We discover that the energy-integral of time-delay is an adiabatic invariant
in quantum scattering theory and corresponds classically to the phase space
volume. The integral thus found provides a quantization condition for
resonances, explaining a series of results recently found in non-relativistic
and relativistic regimes. Further, a connection between statistical quantities
like quantal resonance-width and classical friction has been established with a
classically deterministic quantity, the stability exponent of an adiabatically
perturbed periodic orbit. This relation can be employed to estimate the rate of
energy dissipation in finite quantum systems.",0408169v1
2004-09-01,"""Paradoxical"" coexistence of continuum of 'bound' waves and discrete set of unlimited motion states","We have combined two remarkable phenomena: resonance tunneling and Anderson
localization. It results in unexpected spectrum reverse to usual notions. It is
demonstrated by the quantum system with chaotic distribution of potential
resonance tunneling traps over the whole coordinate axis. The corresponding
spectrum contains continuum of 'bound' states (Anderson's localization) and
discrete tunneling resonances of unlimited wave propagation. It is in contrast
to the usual situation with discrete bound and continuum of scattering states.",0409004v1
2004-09-28,Bound and resonance states of the nonlinear Schroedinger equation in simple model systems,"The stationary nonlinear Schroedinger equation, or Gross-Pitaevskii equation,
is studied for the cases of a single delta potential and a delta-shell
potential. These model systems allow analytical solutions, and thus provide
useful insight into the features of stationary bound, scattering and resonance
states of the nonlinear Schroedinger equation. For the single delta potential,
the influence of the potential strength and the nonlinearity is studied as well
as the transition from bound to scattering states. Furthermore, the properties
of resonance states for a repulsive delta-shell potential are discussed.",0409199v1
2004-10-04,Nanomechanical Quantum Memory for Superconducting Qubits,"Many protocols for quantum computation require a quantum memory element to
store qubits. We discuss the accuracy with which quantum states prepared in a
Josephson junction qubit can be stored in a nanoelectromechanical resonator and
then transfered back to the junction. We find that the fidelity of the memory
operation depends on both the junction-resonator coupling strength and the
location of the state on the Bloch sphere. Although we specifically focus on a
large-area, current-biased Josesphson junction phase qubit coupled to the
dilatational mode of a piezoelectric nanoelectromechanical disk resonator, many
our results will apply to other qubit-oscillator models.",0410029v1
2004-11-15,Electric circuit networks equivalent to chaotic quantum billiards,"We formulate two types of electric RLC resonance network equivalent to
quantum billiards. In the network of inductors grounded by capacitors squared
resonant frequencies are eigenvalues of the quantum billiard. In the network of
capacitors grounded by inductors squared resonant frequencies are given by
inverse eigen values of the billiard. In both cases local voltages play role of
the wave function of the quantum billiard. However as different from quantum
billiards there is a heat power because of resistance of the inductors. In the
equivalent chaotic billiards we derive the distribution of the heat power which
well describes numerical statistics.",0411100v1
2004-12-06,Transmission of ultracold atoms through a micromaser: detuning effects,"The transmission probability of ultracold atoms through a micromaser is
studied in the general case where a detuning between the cavity mode and the
atomic transition frequencies is present. We generalize previous results
established in the resonant case (zero detuning) for the mesa mode function. In
particular, it is shown that the velocity selection of cold atoms passing
through the micromaser can be very easily tuned and enhanced using a
non-resonant field inside the cavity. Also, the transmission probability
exhibits with respect to the detuning very sharp resonances that could define
single cavity devices for high accuracy metrology purposes (atomic clocks).",0412044v1
2004-12-21,Creating Ground State Molecules with Optical Feshbach Resonances in Tight Traps,"We propose to create ultracold ground state molecules in an atomic
Bose-Einstein condensate by adiabatic crossing of an optical Feshbach
resonance. We envision a scheme where the laser intensity and possibly also
frequency are linearly ramped over the resonance. Our calculations for
$^{87}$Rb show that for sufficiently tight traps it is possible to avoid
spontaneous emission while retaining adiabaticity, and conversion efficiencies
of up to 50% can be expected.",0412166v2
2005-06-03,Cooling trapped atoms in optical resonators,"We derive an equation for the cooling dynamics of the quantum motion of an
atom trapped by an external potential inside an optical resonator. This
equation has broad validity and allows us to identify novel regimes where the
motion can be efficiently cooled to the potential ground state. Our result
shows that the motion is critically affected by quantum correlations induced by
the mechanical coupling with the resonator, which may lead to selective
suppression of certain transitions for the appropriate parameters regimes,
thereby increasing the cooling efficiency.",0506030v2
2005-08-25,Lower bounds on the absorption probability of beam splitters,"We derive a lower limit to the amount of absorptive loss present in passive
linear optical devices such as a beam splitter. We choose a particularly simple
beam splitter geometry, a single planar slab surrounded by vacuum, which
already reveals the important features of the theory. It is shown that, using
general causality requirements and statistical arguments, the lower bound
depends on the frequency of the incident light and the transverse resonance
frequency of a suitably chosen single-resonance model only. For symmetric beam
splitters and reasonable assumptions on the resonance frequency $\omega_T$, the
lower absorption bound is $p_{\min}\approx 10^{-6}(\omega/\omega_T)^4$.",0508189v1
2005-08-27,Resonant States of Wave Propagation in Disordered System of Bosonic Particles,"We demonstrate the effects of an induced disorder (or a free-orientation :
$\theta$ which is related to the relative direction of scattering of particles
w.r.t. to the normal of the propagating plane-wave front) upon the possible
resonance of the plane (sound) wave propagating in Bose gases by using the
quantum kinetic equations. We firstly present the diverse dispersion relations
obtained by the relevant Pauli-blocking parameter $B$ (which describes the Bose
particles when $B$ is positive) and the free-orientation $\theta$ and then,
based on the acoustic analog, address the possible resonant states.",0508204v1
2006-02-08,Short-time quantum correlations in the atom optics kicked rotor,"We experimentally verify the analytical expressions that exist for the
diffusion rate in the quantum delta kicked rotor system for small numbers of
kicks. We show development of diffusion resonances from two to five kicks, and
of multiple resonances for high kick strengths. Furthermore, we show that, in
contrast to classical predictions, the results are purely periodic in the kick
period, and reproduce the predicted quantum- and diffusion resonances.",0602081v2
2006-05-03,Quantum memory protocol in QED cavity based on Photon echo,"A new protocol of the optical quantum memory based on the resonant
interactions of the multi atomic system with a cavity light mode is proposed.
The quantum memory is realized using a controllable inversion of the
inhomogeneous broadening of the resonant atomic transition and impact
interaction (on request) of additional short 2 - laser pulse resonant to an
adjacent atomic transition. We demonstrate that the quantum memory protocol is
effective for arbitrary storage time and can be used for new quantum
manipulations with transient entangled states in the field-atoms evolution. The
effect of the fast absorption and emission of the light field is predicted.",0605035v3
2006-06-06,Preparation of atomic velocities by bound-state to resonance conversion,"A procedure is proposed to control the average and width of the velocity
distribution of ultra-cold atoms. The atoms are set initially in a bound state
of an optical trap formed by an inner red detuned laser and an outer blue
detuned laser. The bound state is later converted into a resonance by a
suitable change of the laser intensities. An optimal time dependence of the
switching process, between the sudden and adiabatic limits, adjusts the final
translational energies to the Lorentzian shape of the resonance state.",0606047v1
2006-10-19,Resonant Propagation of Entangled Rhodium Mossbauer Gammas,"We report the resonant propagation of the long-lived Mossbauer gamma in the
time-resolved Mossbauer spectroscopy. Recently, three entangled gammas emitted
from the E3 rhodium Mossbauer transition has been proposed to interpret the
extraordinary observations in the previous report. Further observation reported
here is the dynamic beat of these entangled gammas at room temperature and 77K.
Apparent beat anisotropy reveals their long-distance resonant propagation,
which leads to suppressed Doppler shift of entangled photon transport in the
Borrmann channel.",0610163v1
2006-10-27,Quantum Mechanical Reflection Resonances,"Resonances in the reflection probability amplitude r(E) can occur in energy
ranges in which the reflection probability R(E)=|r(E)|^2 is 1. They occur as
the phase phi(E) defined by r(E) = t*(E)/t(E) = 1e^{i 2phi(E)} undergoes a
rapid change of pi radians. During this transition the phase angle exhibits a
Lorentzian profile in that d(phi(E))/dE ~= 1/[(E-E_0)^2+(hbar*gamma/2)^2]. The
energy E_0 identifies the location of a quasi-bound state, gamma measures the
lifetime of this state, and t(E) is a matrix element of the transfer operator.
Methods for computing and measuring these resonances are proposed.",0610239v1
2007-03-12,Generating entanglement between quantum dots with different resonant frequencies based on Dipole Induced Transparency,"We describe a method for generating entanglement between two spatially
separated dipoles coupled to optical micro-cavities.
  The protocol works even when the dipoles have different resonant frequencies
and radiative lifetimes.
  This method is particularly important for solid-state emitters, such as
quantum dots, which suffer from large inhomogeneous broadening. We show that
high fidelities can be obtained over a large dipole detuning range without
significant loss of efficiency. We analyze the impact of higher order photon
number states and cavity resonance mismatch on the performance of the protocol.",0703089v2
1996-01-11,The Three-Wave Resonant Interaction: Deformation of the Plane-Wave Solutions and Darboux Transformations,"The plane wave solutions of the three-wave resonant interaction in the plane
are considered. It is shown that rank-one constraints over the right
derivatives of invertible operators on an arbitrary linear space gives
solutions of the three-wave resonant interaction that can be understood as a
Darboux transformation of the plane wave solutions. The method is extended
further to obtain general Darboux transformations: for any solution of the
three-wave interaction problem and vector solutions of the corresponding Lax
pair large families of new solutions, expressed in terms of Grammian type
determinants of these vector solutions, are given.",9601002v1
1999-11-03,Resonant Bifurcations,"We consider dynamical systems depending on one or more real parameters, and
assuming that, for some ``critical'' value of the parameters, the eigenvalues
of the linear part are resonant, we discuss the existence -- under suitable
hypotheses -- of a general class of bifurcating solutions in correspondence to
this resonance. These bifurcating solutions include, as particular cases, the
usual stationary and Hopf bifurcations. The main idea is to transform the given
dynamical system into normal form (in the sense of Poincar\'e-Dulac), and to
impose that the normalizing transformation is convergent, using the convergence
conditions in the form given by A. Bruno. Some specially interesting
situations, including the cases of multiple-periodic solutions, and of
degenerate eigenvalues in the presence of symmetry, are also discussed with
some detail.",9911003v1
2007-04-17,Dissipation in graphene and nanotube resonators,"Different damping mechanisms in graphene nanoresonators are studied: charges
in the substrate, ohmic losses in the substrate and the graphene sheet,
breaking and healing of surface bonds (Velcro effect), two level systems,
attachment losses, and thermoelastic losses. We find that, for realistic
structures and contrary to semiconductor resonators, dissipation is dominated
by ohmic losses in the graphene layer and metallic gate. An extension of this
study to carbon nanotube-based resonators is presented.",0704.2225v3
2007-04-20,Resonant decompositions and the I-method for cubic nonlinear Schrodinger on R^2,"The initial value problem for the cubic defocusing nonlinear Schr\""odinger
equation $i \partial_t u + \Delta u = |u|^2 u$ on the plane is shown to be
globally well-posed for initial data in $H^s (\R^2)$ provided $s>1/2$. The
proof relies upon an almost conserved quantity constructed using multilinear
correction terms. The main new difficulty is to control the contribution of
resonant interactions to these correction terms. The resonant interactions are
significant due to the multidimensional setting of the problem and some
orthogonality issues which arise.",0704.2730v1
2007-04-25,Harmonic Generation from Laser-Irradiated Clusters,"The harmonic emission from cluster nanoplasmas subject to short, intense
infrared laser pulses is analyzed by means of particle-in-cell simulations. A
pronounced resonant enhancement of the low-order harmonic yields is found when
the Mie plasma frequency of the ionizing and expanding cluster resonates with
the respective harmonic frequency. We show that a strong, nonlinear resonant
coupling of the cluster electrons with the laser field inhibits coherent
electron motion, suppressing the emitted radiation and restricting the spectrum
to only low-order harmonics. A pump-probe scheme is suggested to monitor the
ionization dynamics of the expanding clusters.",0704.3401v1
2007-05-21,Feshbach resonances in ultracold K(39),"We discover several magnetic Feshbach resonances in collisions of ultracold
K(39) atoms, by studying atom losses and molecule formation. Accurate
determination of the magnetic-field resonance locations allows us to optimize a
quantum collision model for potassium isotopes. We employ the model to predict
the magnetic-field dependence of scattering lengths and of near-threshold
molecular levels. Our findings will be useful to plan future experiments on
ultracold potassium atoms and molecules.",0705.3036v1
2007-05-22,Scalar resonances: scattering and production amplitudes,"Scattering and production amplitudes involving scalar resonances are known,
according to Watson's theorem, to share the same phase $\delta(s)$. We show
that, at low energies, the production amplitude is fully determined by the
combination of $\delta(s)$ with another phase $\omega(s)$, which describes
intermediate two-meson propagation and is theoretically unambiguous. Our main
result is a simple and almost model independent expression, which generalizes
the usual $K$-matrix unitarization procedure and is suited to be used in
analyses of production data involving scalar resonances.",0705.3260v2
2007-05-27,Conversion of $^{40}$K-$^{87}$Rb mixtures into stable molecules,"We study the conversion of $^{40}$K and $^{87}$Rb atoms into stable molecules
through the stimulated Raman adiabatic passage (STIRAP) in photoassociation
assisted with Feshbach resonance. Starting with the mean-field Langrange
density, we show that the atom-to-molecule conversion efficiency by STIRAP
aided by Feshbach resonance is much larger than that by bare Feshbach
resonance. We also study the influence of the population imbalance on the
atom-to-molecule conversion.",0705.3935v2
2007-05-31,"Determination of the $ψ(3770)$, $ψ(4040)$, $ψ(4160)$ and $ψ(4415)$ resonance parameters","$R$ measurement data taken with the BESII detector at center-of-mass energies
between 3.7 and 5.0 GeV is fitted to determine resonance parameters (mass,
total width, electron width) of the high mass charmonium states, $\psi(3770)$,
$\psi(4040)$, $\psi(4160)$ and $\psi(4415)$. Various effects, including the
relative phases between the resonances, interferences, the energy-dependence of
the full widths, and the initial state radiative correction, are examined. The
results are compared to previous studies.",0705.4500v1
2007-06-21,First Order Superfluid to Bose Metal Transition in Systems with Resonant Pairing,"Systems showing resonant superfluidity, driven by an exchange coupling of
strength $g$ between uncorrelated pairs of itinerant fermions and tightly bound
ones, undergo a first order phase transition as $g$ increases beyond some
critical value $g_c$. The superfluid phase for $g \leq g_c$ is characterized by
a gap in the fermionic single particle spectrum and an acoustic sound-wave like
collective mode of the bosonic resonating fermion pairs inside this gap. For
$g>g_c$ this state gives way to a phase uncorrelated bosonic liquid with a
$q^2$ spectrum.",0706.3143v1
2007-06-25,Exclusive Double Charmonium Production from $Υ$ Decay,"The exclusive decay of $\Upsilon$ to a vector plus pseudoscalar charmonium is
studied in perturbative QCD. The corresponding branching ratios are predicted
to be of order $10^{-6}$ for first three $\Upsilon$ resonances, and we expect
these decay modes should be discovered in the prospective high-luminosity
$e^+e^-$ facilities such as super $B$ experiment. As a manifestation of the
short-distance loop contribution, the relative phases among strong,
electromagnetic and radiative decay amplitudes can be deduced. It is
particularly interesting to find that the relative phase between strong and
electromagnetic amplitudes is nearly orthogonal. The resonance-continuum
interference effect for double charmonium production near various $\Upsilon$
resonances in $e^+e^-$ annihilation is addressed.",0706.3685v1
2007-06-27,Shot noise in the interacting resonance level model,"The shot noise power and the Fano factor of a spinless resonant level model
is calculated. The Coulomb interaction which in this model acts between the
lead electron and the impurity is considered in the first order approximation.
The logarithmic divergencies which appeared in the expressions for shot noise
and the transport current are removed by renormalization group analysis. It is
shown that Keldysh technique gives an adequate description of perturbation
theory results. By passing to the bosonized form of the resonance model it is
proven that in the strong interaction limit the tunnelling becomes irrelevant
and decreases.",0706.4003v2
2007-07-04,Hyperfine-mediated gate-driven electron spin resonance,"An all-electrical spin resonance effect in a GaAs few-electron double quantum
dot is investigated experimentally and theoretically. The magnetic field
dependence and absence of associated Rabi oscillations are consistent with a
novel hyperfine mechanism. The resonant frequency is sensitive to the
instantaneous hyperfine effective field, and the effect can be used to detect
and create sizable nuclear polarizations. A device incorporating a micromagnet
exhibits a magnetic field difference between dots, allowing electrons in either
dot to be addressed selectively.",0707.0557v2
2007-07-05,Coherence and clock shifts in ultracold Fermi gases with resonant interactions,"Using arguments based on sum rules, we derive a general result for the
average shifts of rf lines in Fermi gases in terms of interatomic interaction
strengths and two-particle correlation functions. We show that near an
interaction resonance shifts vary inversely with the atomic scattering length,
rather than linearly as in dilute gases, thus accounting for the experimental
observation that clock shifts remain finite at Feshbach resonances.",0707.0859v1
2007-07-09,Engineering Quantum States of a Nano-Resonator via a Simple Auxiliary System,"We show how to engineer an extensive range of non-linear Hamiltonians for a
nano-mechanical resonator. The technique requires only a time dependent drive
applied to a Cooper-pair box or second oscillator to which the nano-resonator
is coupled. This method allows one to generate a large number of non-classical
states, as well as Hamiltonians whose classical counterparts are chaotic.",0707.1348v1
2007-07-17,Observations of interior whispering gallery modes in asymmetric optical resonators with rational caustics,"We propose asymmetric resonant cavities with rational caustics and
experimentally demonstrate interior whispering gallery modes in monolithic
silicon mesoscopic microcavities. These microcavities demonstrate unique
robustness of cavity quality factor (Q) against roughness Rayleigh scattering.
Angle-resolved tapered fiber measurements and near-field images observe
distinct resonant families and asymmetric emission from interior whispering
gallery modes, which can be used for microcavity laser and CQED applications.",0707.2552v2
2007-07-24,Form Factors in the Quark Resonance Model,"Vector and axial form factors in the quark resonance model are analyzed with
a combination of theoretical and phenomenological arguments. The new form of
form factors is deduced from $\Delta$(1232) excitation models and available
data. The vector part is shown to agree with the resonant contribution to
electron-proton inclusive $F_2$ data. The axial part is obtained by finding a
simultaneous fit to ANL and BNL $\frac{d \sigma}{d Q^2}$ neutrino scattering
data. The best fit corresponds to $C_5^A(0)=0.88$ in the Rarita Schwinger
formalism.",0707.3561v2
2007-07-24,Molecular production at a wide Feshbach resonance in Fermi-gas of cooled atoms,"The problem of molecular production from degenerate gas of fermions at a wide
Feshbach resonance, in a single-mode approximation, is reduced to the linear
Landau-Zener problem for operators. The strong interaction leads to significant
renormalization of the gap between adiabatic levels. In contrast to static
problem the close vicinity of exact resonance does not play substantial role.
Two main physical results of our theory is the high sensitivity of molecular
production to the initial value of magnetic field and generation of a large BCS
condensate distributed over a broad range of momenta in inverse process of the
molecule dissociation.",0707.3630v1
2007-07-30,Comments on ``Spin Connection Resonance in Gravitational General Relativity'',"We comment on a recent article of M.W.Evans, Acta Physica Polonica B38 (2007)
2211. We point out that the equations underlying Evans' theory are highly
problematic. Moreover, we demonstrate that the so-called ``spin connection
resonance'', predicted by Evans, cannot be derived from the equation he used.
We provide an exact solution of Evans' corresponding equation and show that is
has definitely no resonance solutions.",0707.4433v2
2007-08-02,Recoilless Resonance Absorption of Tritium Antineutrinos and Time-Energy Uncertainty Relation,"We discuss neutrino oscillations in an experiment with M\""ossbauer recoilless
resonance absorbtion of tritium antineutrinos, proposed recently by Raghavan.
We demonstrate that small energy uncertainty of antineutrinos which ensures a
large resonance absorption cross section is in a conflict with the energy
uncertainty which, according to the time-energy uncertainty relation, is
necessary for neutrino oscillations to happen. The search for neutrino
oscillations in the M\""ossbauer neutrino experiment would be an important test
of the applicability of the time-energy uncertainty relation to a newly
discovered interference phenomenon.",0708.0260v1
2007-08-02,Coherent Dark Resonances in Atomic Barium,"The observation of dark-resonances in the two-electron atom barium and their
influence on optical cooling is reported. In heavy alkali earth atoms, i.e.
barium or radium, optical cooling can be achieved using n^1S_0-n^1P_1
transitions and optical repumping from the low lying n^1D_2 and n^3D_{1,2}
states to which the atoms decay with a high branching ratio. The cooling and
repumping transition have a common upper state. This leads to dark resonances
and hence make optical cooling less inefficient. The experimental observations
can be accurately modelled by the optical Bloch equations. Comparison with
experimental results allows us to extract relevant parameters for effective
laser cooling of barium.",0708.0332v1
2007-08-03,Stochastic resonance and heat fluctuations in a driven double-well system,"We study a periodically driven (symmetric as well as asymmetric)double-well
potential system at finite temperature. We show that mean heat loss by the
system to the environment(bath) per period of the applied field is a good
quantifier of stochastic resonance. It is found that the heat fluctuations over
a single period are always larger than the work fluctuations. The observed
distributions of work and heat exhibit pronounced asymmetry near resonance. The
heat losses over a large number of periods satisfies the conventional
steady-state fluctuation theorem, though different relation exists for this
quantity.",0708.0496v2
2007-08-13,Entangling a nanomechanical resonator and a superconducting microwave cavity,"We propose a scheme able to entangle at the steady state a nanomechanical
resonator with a microwave cavity mode of a driven superconducting coplanar
waveguide. The nanomechanical resonator is capacitively coupled with the
central conductor of the waveguide and stationary entanglement is achievable up
to temperatures of tens of milliKelvin.",0708.1665v3
2007-08-17,Nondestructive interaction-free atom-photon controlled-NOT gate,"We present a probabilistic (ideally 50%) nondestructive interaction-free
atom-photon controlled-NOT gate, where nondestructive means that all four
outgoing target photon modes of the gate are available and feed-forwardable.
Individual atoms are controlled by a stimulated Raman adiabatic passage
transition and photons by a ring resonator with two outgoing ports. Realistic
estimates we obtain for ions confined in a Paul trap around which the resonator
is mounted show that a strong atom-photon coupling can be achieved. It is also
shown how the resonator can be used for controlling superposition of atom
states.",0708.2302v1
2007-08-17,Feshbach Molecules in a One-dimensional Optical Lattice,"We present the theory of a pair of atoms in a one-dimensional optical lattice
interacting via a narrow Feshbach resonance. Using a two-channel description of
the resonance, we derive analytic results for the scattering states inside the
continuum band and the discrete bound states outside the band. We identify a
Fano resonance profile, and the survival probability of a molecule when swept
through the Bloch band of scattering states by varying an applied magnetic
field. We discuss how these results may be used to investigate the importance
of the structured nature of the continuum in experiments.",0708.2329v2
2007-08-20,Eigen electric moments of magnetic-dipolar modes in quasi-2D ferrite disk particles,"A property associated with a vortex structure becomes evident from an
analysis of confinement phenomena of magnetic oscillations in a quasi-2D
ferrite disk with a dominating role of magnetic-dipolar
(non-exchange-interaction) spectra. The vortices are guaranteed by the chiral
edge states of magnetic-dipolar modes which result in appearance of eigen
electric moments oriented normally to the disk plane. Due to the
eigen-electric-moment properties, a ferrite disk placed in a microwave cavity
is strongly affected by the cavity RF electric field with a clear evidence for
multi-resonance oscillations. For different cavity parameters, one may observe
the ""resonance absorption"" and ""resonance repulsion"" behaviors.",0708.2678v1
2007-08-22,Controlling the Ratchet Effect for Cold Atoms,"Low-order quantum resonances manifested by directed currents have been
realized with cold atoms. Here we show that by increasing the strength of an
experimentally achievable delta-kicking ratchet potential, quantum resonances
of a very high order may naturally emerge and can induce larger ratchet
currents than low-order resonances, with the underlying classical limit being
fully chaotic. The results offer a means of controlling quantum transport of
cold atoms.",0708.3026v4
2007-08-22,Photoabsorption in a plasma in a high magnetic field,"Photo-absorption in fully ionized plasmas in high magnetic fields is
re-examined, using the methods of many-body quantum field theory. For
frequencies in the immediate vicinity of the electron cyclotron resonance the
rates we obtain disagree markedly from those in the literature. The new element
in our work that causes most of the disagreement is the inclusion of the lowest
order real part of the energy-shift of the resonant state, where, in effect,
previous authors had included only the imaginary part. In a region around and
below the proton cyclotron resonance our results also disagree with those of
previous authors, for a number of reasons.",0708.3049v2
2007-08-27,Influence of the N*(1440) and N*(1535) Resonances in Intermediate Energy pp and np Scattering,"Motivated by a recent measurement of proton-proton elastic scattering
observables up to 3.0 GeV, we investigate the description of those data within
models of the nucleon-nucleon (NN) interaction valid above the pion production
threshold. In addition to including the well known Delta resonance we
incorporate two low-lying N* resonances, the N*(1440) and the N*(1535), and
study their influence on pp and np observables for projectile laboratory
kinetic energies up to 1.5 GeV.",0708.3692v1
2007-09-05,Arbitrary precision composite pulses for NMR quantum computing,"We discuss the implementation of arbitrary precision composite pulses
developed using the methods of Brown et al. [Phys. Rev. A 70 (2004) 052318]. We
give explicit results for pulse sequences designed to tackle both the simple
case of pulse length errors and for the more complex case of off-resonance
errors. The results are developed in the context of NMR quantum computation,
but could be applied more widely.",0709.0602v1
2007-09-18,Approximate Model of Neutron Resonant Scattering in a Crystal,"In the theory of resonant scattering, the double differential cross section
involves the computation of a multifold integral of a 4-point correlation
function, which generalizes the traditional 2-point correlation function of
Van-Hove for potential scattering. In the case of a neutron-crystal
interaction, the numerical computation of these multifold integrals is
cumbersome. In this paper, a new approximation is suggested. It is based on a
factorization of the differential cross section into one function describing
the exchange of kinetic energy between the neutron and the bound nucleus
(phonons dynamic) and a function related to the nuclear scattering amplitude.
This formalism is then applied to the modeling of resonant scattering of a
neutron by $^{238}U$ in a $UO_2$ crystal lattice.",0709.2767v1
2007-09-18,Unoccupied states of individual silver clusters and chains on Ag(111),"Size-selected silver clusters on Ag(111) were fabricated with the tip of a
scanning tunneling microscope. Unoccupied electron resonances give rise to
image contrast and spectral features which shift toward the Fermi level with
increasing cluster size. Linear assemblies exhibit higher resonance energies
than equally sized compact assemblies. Density functional theory calculations
reproduce the observed energies and enable an assignment of the resonances to
hybridized atomic 5s and 5p orbitals with silver substrate states.",0709.2796v1
2007-09-20,Spin wave resonances in La_{0.7}Sr_{0.3}MnO_{3} films: measurement of spin wave stiffness and anisotropy field,"We studied magnetic field dependent microwave absorption in epitaxial
La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films using an X-band Bruker ESR spectrometer. By
analyzing angular and temperature dependence of the ferromagnetic and spin-wave
resonances we determine spin-wave stiffness and anisotropy field. The spin-wave
stiffness as found from the spectrum of the standing spin-wave resonances in
thin films is in fair agreement with the results of inelastic neutron
scattering studies on a single crystal of the same composition [Vasiliu-Doloc
et al., J. Appl. Phys. \textbf{83}, 7343 (1998)].",0709.3204v2
2007-09-21,Forty-Four Pass Fibre Optic Loop for Improving the Sensitivity of Surface Plasmon Resonance Sensors,"A forty-four pass fibre optic surface plasmon resonance sensor that enhances
detection sensitivity according to the number of passes is demonstrated for the
first time. The technique employs a fibre optic recirculation loop that passes
the detection spot forty- four times, thus enhancing sensitivity by a factor of
forty-four. Presently, the total number of passes is limited by the onset of
lasing action of the recirculation loop. This technique offers a significant
sensitivity improvement for various types of plasmon resonance sensors that may
be used in chemical and biomolecule detections.",0709.3504v1
2007-09-22,Multiphoton Bloch-Siegert shifts and level-splittings in spin-one systems,"We consider a spin-boson model in which a spin 1 system is coupled to an
oscillator. A unitary transformation is applied which allows a separation of
terms responsible for the Bloch-Siegert shift, and terms responsible for the
level splittings at anticrossings associated with Bloch-Siegert resonances.
When the oscillator is highly excited, the system can maintain resonance for
sequential multiphoton transitions. At lower levels of excitation, resonance
cannot be maintained because energy exchange with the oscillator changes the
level shift. An estimate for the critical excitation level of the oscillator is
developed.",0709.3557v1
2007-10-05,NIR Femtosecond Control of Resonance-Mediated Generation of Coherent Broadband UV Emission,"We use shaped near-infrared (NIR) pulses to control the generation of
coherent broadband ultraviolet (UV) radiation in an atomic resonance-mediated
(2+1) three-photon excitation. Experimental and theoretical results are
presented for phase controlling the total emitted UV yield in atomic sodium
(Na). Based on our confirmed understanding, we present a new simple scheme for
producing shaped femtosecond pulses in the UV/VUV spectral range using the
control over atomic resonance-mediated generation of third (or higher order)
harmonic.",0710.1226v1
2007-10-06,Interference-induced splitting of resonances in spontaneous emission,"We study the resonance fluorescence from a coherently driven four-level atom
in the Y-type configuration. The effects of quantum interference induced by
spontaneous emission on the fluorescence properties of the atom are
investigated. It is found that the quantum interference resulting from cascade
emission decays of the atom leads to a splitting of resonances in the excited
level populations calculated as a function of light detuning. For some
parameters, interference assisted enhancement of inner sidebands and narrowing
of central peaks may also occur in the fluorescence spectrum. We present a
physical understandingof our numerical results using the dressed state
description of the atom-light interaction.",0710.1388v1
2007-10-12,Coherent Spin Manipulations of a Polarized Beam With a Localized RF Magnetic Field,"The coherent manipulation of spin observables in storage rings provides
opportunities to test the application of some fundamental dynamical principles.
In this context, it is possible to confirm, using gauge invariance and Lorentz
invariance, a conjecture framed by A. M. Kondratenko concerning the ""natural""
or ""intrinsic"" resonance strength applicable to a spin rotation from a
controlled Froissart-Stora sweep with an RF dipole magnet. The discussion
includes a brief treatment of the ""forced"" component of the resonance strength
associated with the effect of the betatron oscillations induced by the
operation of the RF diple and a discussion of the effective resonance strength
as a function of betatron tunes.",0710.2566v1
2007-10-13,Transmission resonances for a Dirac particle in a one-dimensional Hulthén potential,"We have solved exactly the two-component Dirac equation in the presence of a
spatially one-dimensional Hulth\'en potential, and presented the Dirac spinors
of scattering states in terms of hypergeometric functions. We have calculated
the reflection and transmission coefficients by the matching conditions on the
wavefunctions, and investigated the condition for the existence of transmission
resonances. Furthermore, we have demonstrated how the transmission-resonance
condition depends on the shape of the potential.",0710.2576v1
2007-10-15,High photo-excited carrier multiplication by charged InAs dots in AlAs/GaAs/AlAs resonant tunneling diode,"We present an approach for the highly sensitive photon detection based on the
quantum dots (QDs) operating at temperature of 77K. The detection structure is
based on an AlAs/GaAs/AlAs double barrier resonant tunneling diode combined
with a layer of self-assembled InAs QDs (QD-RTD). A photon rate of 115 photons
per second had induced 10nA photocurrent in this structure, corresponding to
the photo-excited carrier multiplication factor of 10^7. This high
multiplication factor is achieved by the quantum dot induced memory effect and
the resonant tunneling tuning effect of QD-RTD structure.",0710.2711v1
2007-10-16,Pion-nucleon P_33 and P_11 scatterings in the Lippmann-Schwinger approach,"We study the pion-nucleon P_33 and P_11 scattering, where the Delta and the
Roper resonances are seen, respectively. We use the Lippmann-Schwinger equation
extended to couple to a one-body state, and investigate nature of these
resonances by taking and omitting a one-baryon state into account. We see
validity and puzzle of the standard quark model interpretation, for the Delta
and the Roper resonances, respectively.",0710.3026v1
2007-10-16,Fano resonance in a two-level quantum dot side-coupled to leads,"We theoretically study Fano resonance in a two-level quantum dot side-coupled
to two leads, which are connected by a direct channel. The resonance lineshape
is found to be deformed, from the conventional Fano form, by interlevel Coulomb
interaction and interlevel interference. We derive the connection between the
lineshape deformation and the interaction-induced nonmonotonicity of level
occupation, which may be useful for experimental study. The dependence of the
lineshape on the transmission of the direct channel and on the dot-lead
coupling matrix elements is discussed.",0710.3045v1
2007-10-22,Upper and lower bounds on resonances for manifolds hyperbolic near infinity,"For a conformally compact manifold that is hyperbolic near infinity and of
dimension $n+1$, we complete the proof of the optimal $O(r^{n+1})$ upper bound
on the resonance counting function, correcting a mistake in the existing
literature. In the case of a compactly supported perturbation of a hyperbolic
manifold, we establish a Poisson formula expressing the regularized wave trace
as a sum over scattering resonances. This leads to an $r^{n+1}$ lower bound on
the counting function for scattering poles.",0710.3894v2
2007-10-30,Chiral constituent quark model study of the process $γp \to η p$,"A constituent quark model is developed for the reaction, allowing us to
investigate all available data for differential cross sections as well as
single polarization asymmetries (beam and target) by including {\it all} of the
PDG, one to four star, nucleon resonances ($S_{11}$, $P_{11}$, $P_{13}$,
$D_{13}$, $D_{15}$, $F_{15}$, $F_{17}$, $G_{17}$, $G_{19}$, $H_{19}$,
$I_{1,11}$, and $K_{1,13}$). Issues related to the missing resonances are also
briefly discussed by examining possible contributions from several new
resonances ($S_{11}$, $P_{11}$, $P_{13}$, $D_{13}$, $ D_{15}$, and $H_{1,11}$).",0710.5677v1
2007-11-02,Magnetic resonance as an orbital state probe,"Magnetic resonance in ordered state is shown to be the direct method for
distinguishing the orbital ground state. The example of perovskite titanates,
particularly, LaTiO3 and YTiO3, is considered. External magnetic field
resonance spectra of these crystals reveal glaring qualitative dependence on
assumed orbital state of the compounds: orbital liquid or static orbital
structure. Theoretical basis for using the method as an orbital state probe is
grounded.",0711.0333v2
2007-11-07,Statistics of Resonances in a Semi-infinite Disordered Chain,"We study the average density of resonances (DOR) for a semi-infinite
disordered chain, coupled to the outside world by a (semi-infinite) perfect
lead. A set of equations is derived, which provides the general framework for
calculating the average DOR, for an arbitrary disorder and coupling strength.
These general equations are applied to the case of weak coupling and an
asymptotically exact expression for the averaged DOR is derived, in the limit
of small resonance width. This expression is universal, in the sense that it
holds for any degree of disorder and everywhere in the (unperturbed) energy
band.",0711.1040v1
2007-11-09,Rare-earth Doped Amorphous Silicon Microdisk and Microstadium Resonators with Emission at 1550nm,"Microdisks and microstadium resonators were fabricated on erbium doped
amorphous hydrogenated silicon (a-Si:H<Er>) layers sandwiched in air and native
SiO2 on Si substrates. Annealing condition is optimized to allow large emission
at 1550 nm for samples with erbium concentrations as high as 1.02x10^20
atoms/cm3. Near field scanning optical microscopy shows evidences of the
simultaneous presence of bow-tie and diamond scars. These modes indicate the
high quality of the resonators and the potentiality for achieving amorphous
silicon microcavity lasers.",0711.1549v1
2007-11-11,Kicked rotor quantum resonances in position space,"We present an approach of the kicked rotor quantum resonances in
position-space, based on its analogy with the optical Talbot effect. This
approach leads to a very simple picture of the physical mechanism underlying
the dynamics and to analytical expressions for relevant physical quantities,
such as mean momentum or kinetic energy. The ballistic behavior, which is
closely associated to quantum resonances, is analyzed and shown to emerge from
a coherent adding of successive kicks applied to the rotor thanks to a periodic
reconstruction of the spatial wavepacket.",0711.1674v1
2007-11-14,Power thresholds of morphology dependent induced thermal scattering in silica microresonators,"Induced thermal scattering power thresholds have been calculated as a
function of size and laser pump frequency. The thermal coupling coefficients of
morphology dependent resonances were estimated by asymptotic methods. The
resulting power threshold is comparable with experimental observations of
thresholds of Raman lasing and thermal instability in spherical silica
resonators. Applications may include the remote measurement of the temperature
of aerosol droplets and the stabilization of microcavity lasers against thermal
oscillations and temperature deviations on microcavity. A silica resonator can
be used as an IR sensor, as well as an additional tool for precisely measuring
the thermal conductivity and heat capacity of a target in a microsphere by
calculating of the thermal shifts of eigenfrequencies in spectra of nonlinear
scattering.",0711.2247v1
2007-11-16,Resonances in Ps-H scattering,"The best 3-channel projectile-inelastic [H(1s)+Ps(1s,2s,2p)] close-coupling
approximation (CCA) is performed for positronium (Ps) and hydrogen (H)
collision considering both the atoms in ground states at the incident channel.
The s-wave elastic phase shifts and cross sections in the singlet and triplet
channels and the total (or integrated) cross section are studied below
inelastic threshold. Resonances in singlet channel using 2-channel and
3-channel projectile-inelastic CCAs confirm earlier prediction [1]. A resonance
in triplet channel using 3-channel projectile-inelastic CCA is a new addition.",0711.2566v1
2007-11-19,Dilaton as a Dark Matter Candidate and its Detection,"Assuming that the dilaton is the dark matter of the universe, we propose an
experiment to detect the relic dilaton using the electromagnetic resonant
cavity, based on the dilaton-photon conversion in strong electromagnetic
background. We calculate the density of the relic dilaton, and estimate the
dilaton mass for which the dilaton becomes the dark matter of the universe.
With this we calculate the dilaton detection power in the resonant cavity, and
compare it with the axion detection power in similar resonant cavity
experiment.",0711.2858v1
2007-11-21,Electrostatically-Driven Resonator on Soi with Improved Temperature Stability,"This paper deals with a single-crystal-silicon (SCS) MEMS resonator with
improved temperature stability. While simulations have shown that the
temperature coefficient of resonant frequency can be down to 1 ppm/degrees C,
preliminary measurements on non-optimised structures gave evidence of a
temperature coefficient of 29 ppm/degrees C. Design, optimisation, experimental
results with post process simulation and prospective work are presented.",0711.3288v1
2007-11-23,Resonant Fibonacci Quantum Well Structures,"We propose a resonant one-dimensional quasicrystal, namely, a multiple
quantum well (MQW) structure satisfying the Fibonacci-chain rule with the
golden ratio between the long and short inter-well distances. The resonant
Bragg condition is generalized from the periodic to Fibonacci MQWs. A
dispersion equation for exciton-polaritons is derived in the two-wave
approximation, the effective allowed and forbidden bands are found. The
reflection spectra from the proposed structures are calculated as a function of
the well number and detuning from the Bragg condition.",0711.3769v1
2007-12-03,Tunable resonators for quantum circuits,"We have designed, fabricated and measured high-Q $\lambda/2$ coplanar
waveguide microwave resonators whose resonance frequency is made tunable with
magnetic field by inserting a DC-SQUID array (including 1 or 7 SQUIDs) inside.
Their tunability range is 30% of the zero field frequency. Their quality factor
reaches up to 3$\times10^4$. We present a model based on thermal fluctuations
that accounts for the dependance of the quality factor with magnetic field.",0712.0221v1
2007-12-06,Electron resonant tunneling through InAs/GaAs quantum dots embedded in a Schottky diode with an AlAs insertion layer,"Molecular beam epitaxy is employed to manufacture self-assembled InAs/GaAs
quantum dot Schottky resonant tunneling diodes. By virtue of a thin AlAs
insertion barrier, the thermal current is effectively reduced and electron
resonant tunneling through quantum dots under both forward and reverse biased
conditions is observed at relatively high temperature of 77K. The ground states
of quantum dots are found to be at ~0.19eV below the conduction band of GaAs
matrix. The theoretical computations are in conformity with experimental data.",0712.0980v1
2007-12-19,Real stabilization method for nuclear single particle resonances,"We develop the real stabilization method within the framework of the
relativistic mean field (RMF) model. With the self-consistent nuclear
potentials from the RMF model, the real stabilization method is used to study
single-particle resonant states in spherical nuclei. As examples, the energies,
widths and wave functions of low-lying neutron resonant states in $^{120}$Sn
are obtained. These results are compared with those from the scattering phase
shift method and the analytic continuation in the coupling constant approach
and satisfactory agreements are found.",0712.3087v1
2008-01-15,Broadband ferromagnetic resonance of Ni81Fe19 wires using a rectifying effect,"The broadband ferromagnetic resonance measurement using the rectifying effect
of Ni81Fe19 wire has been investigated. One wire is deposited on the center
strip line of the coplanar waveguide (CPW) and the other one deposited between
two strip lines of CPW. The method is based on the detection of the
magnetoresistance oscillation due to the magnetization dynamics induced by the
radio frequency field. The magnetic field dependences of the resonance
frequency and the rectification spectrum are presented and analytically
interpreted on the standpoint of a uniform magnetization precession model.",0801.2203v1
2008-01-21,Quantum Forbidden-Interval Theorems for Stochastic Resonance,"We extend the classical forbidden-interval theorems for a
stochastic-resonance noise benefit in a nonlinear system to a quantum-optical
communication model and a continuous-variable quantum key distribution model.
Each quantum forbidden-interval theorem gives a necessary and sufficient
condition that determines whether stochastic resonance occurs in quantum
communication of classical messages. The quantum theorems apply to any quantum
noise source that has finite variance or that comes from the family of
infinite-variance alpha-stable probability densities. Simulations show the
noise benefits for the basic quantum communication model and the
continuous-variable quantum key distribution model.",0801.3141v1
2008-01-23,Characterization of strong light-matter coupling in semiconductor quantum-dot microcavities via photon-statistics spectroscopy,"It is shown that spectrally resolved photon-statistics measurements of the
resonance fluorescence from realistic semiconductor quantum-dot systems allow
for high contrast identification of the two-photon strong-coupling states.
Using a microscopic theory, the second-rung resonance is analyzed and optimum
excitation conditions are determined. The computed photon-statistics spectrum
displays gigantic, experimentally robust resonances at the energetic positions
of the second-rung emission.",0801.3604v1
2008-01-23,Difficulties with the QPOs Resonance Model,"High frequency quasi-periodic oscillations (HFQPOs) have been detected in
microquasars and neutron star systems. The resonance model suggested by
Kluzniak & Abramowicz (2000) explains twin QPOs as two weakly coupled nonlinear
resonant epicyclic modes in the accretion disk. Although this model
successfully explains many features of the observed QPOs, it still faces
difficulties and shortcomings. Here we summarize the aspects of the theory that
remain a puzzle and we briefly discuss likely developments.",0801.3658v1
2008-01-31,Cohomology rings and formality properties of nilpotent groups,"We introduce partial formality and relate resonance with partial formality
properties. For instance, we show that for finitely generated nilpotent groups
that are k-formal, the resonance varieties are trivial up to degree k. We also
show that the cohomology ring of a nilpotent k-formal group is generated in
degree 1, up to degree k+1; this criterion is necessary and sufficient for
2-step nilpotent groups to be k-formal. We compute resonance varieties for
Heisenberg-type groups and deduce the degree of partial formality for this
class of groups.",0801.4847v1
2008-02-01,Field structure and electron life times in the MEFISTO Electron Cyclotron Resonance Ion Source,"The complex magnetic field of the permanent-magnet electron cyclotron
resonance (ECR) ion source MEFISTO located at the University of Bern have been
numerically simulated. For the first time the magnetized volume qualified for
electron cyclotron resonance at 2.45 GHz and 87.5 mT has been analyzed in
highly detailed 3D simulations with unprecedented resolution. New results were
obtained from the numerical simulation of 25211 electron trajectories. The
evident characteristic ion sputtering trident of hexapole confined ECR sources
has been identified with the field and electron trajectory distribution.
Furthermore, unexpected long electron trajectory lifetimes were found.",0802.0092v1
2008-02-05,Far-off-resonant wave interaction in one-dimensional photonic crystals with quadratic nonlinearity,"We extend a recently developed Hamiltonian formalism for nonlinear wave
interaction processes in spatially periodic dielectric structures to the
far-off-resonant regime, and investigate numerically the three-wave resonance
conditions in a one-dimensional optical medium with $\chi^{(2)}$ nonlinearity.
In particular, we demonstrate that the cascading of nonresonant wave
interaction processes generates an effective $\chi^{(3)}$ nonlinear response in
these systems. We obtain the corresponding coupling coefficients through
appropriate normal form transformations that formally lead to the Zakharov
equation for spatially periodic optical media.",0802.0561v1
2008-02-13,Semi-classical approach for Anosov diffeomorphisms and Ruelle resonances,"In this paper, we show that some spectral properties of Anosov
diffeomorphisms can be obtained by semi-classical analysis. In particular the
Ruelle resonances which are eigenvalues of the Ruelle transfer operator acting
in suitable anisotropic Sobolev spaces and which govern the decay of dynamical
correlations, can be treated as the quantum resonances of open quantum systems
in the Aguilar-Baslev-Combes theory or the more recent Helffer-Sjostrand
phase-space theory.",0802.1780v3
2008-02-22,Environmental limits on the non-resonant cosmic-ray current-driven instability,"We investigate the so-called non-resonant cosmic-ray streaming instability,
first discussed by Bell (2004). The extent to which thermal damping and
ion-neutral collisions reduce the growth of this instability is calculated.
Limits on the growth of the non-resonant mode in SN1006 and RX J1713.7-3946 are
presented.",0802.3322v1
2008-03-05,Accurate near-threshold model for ultracold KRb dimers from interisotope Feshbach spectroscopy,"We investigate magnetic Feshbach resonances in two different ultracold K-Rb
mixtures. Information on the K(39)-Rb(87) isotopic pair is combined with novel
and pre-existing observations of resonance patterns for K(40)-Rb(87).
Interisotope resonance spectroscopy improves significantly our near-threshold
model for scattering and bound-state calculations. Our analysis determines the
number of bound states in singlet/triplet potentials and establishes precisely
near threshold parameters for all K-Rb pairs of interest for experiments with
both atoms and molecules. In addition, the model verifies the validity of the
Born-Oppenheimer approximation at the present level of accuracy.",0803.0651v1
2008-03-12,Analysis of angular distributions in gamma N \to pi0 eta N,"Angular distributions in the final state of pi0-eta photoproduction on
nucleons are considered. As a formal base the familiar isobar model is used in
which the (pi0 eta N) state is a product of the resonance decay into
eta-Delta(1232) and pi-S_{11}(1535) channels. One of the principal assumptions
used is that in the actual energy region the reaction is dominated by a single
resonance state. The developed formalism can serve as a tool for testing spin
and parity of that resonance.",0803.1755v1
2008-03-14,Simulations of Sisyphus cooling including multiple excited states,"We extend the theory for laser cooling in a near-resonant optical lattice to
include multiple excited hyperfine states. Simulations are performed treating
the external degrees of freedom of the atom, i.e., position and momentum,
classically, while the internal atomic states are treated quantum mechanically,
allowing for arbitrary superpositions. Whereas theoretical treatments including
only a single excited hyperfine state predict that the temperature should be a
function of lattice depth only, except close to resonance, experiments have
shown that the minimum temperature achieved depends also on the detuning from
resonance of the lattice light. Our results resolve this discrepancy.",0803.2153v1
2008-03-19,Double species condensate with tunable interspecies interactions,"We produce Bose-Einstein condensates of two different species, $^{87}$Rb and
$^{41}$K, in an optical dipole trap in proximity of interspecies Feshbach
resonances. We discover and characterize two Feshbach resonances, located
around 35 and 79 G, by observing the three-body losses and the elastic
cross-section. The narrower resonance is exploited to create a double species
condensate with tunable interactions. Our system opens the way to the
exploration of double species Mott insulators and, more in general, of the
quantum phase diagram of the two species Bose-Hubbard model.",0803.2763v1
2008-03-20,Exotic decay modes of the nucleon resonance $N^*(1535)$ and the $θ^+$ problem,"Baryon resonance state with strangeness $S = +1$ observed in systems $p K^0$
and $n K^+$ is interpreted as a result of the decay $N^{*+} \to p \eta$ of the
well-known resonance $N^*(1535)$ (with spin-parity $j^P = {1/2}^-$ and mass $m
\approx 1.54$ GeV) and the subsequent oscillation $\eta \rightleftarrows K^0$.
It is argued that the latter is noticeably enhanced by the neighbourhood of the
$\eta$ and $K^0$ levels and the gluon exchanges of the ""penguin"" form.",0803.2936v1
2008-03-21,Observation of pinning mode of stripe phases of 2D systems in high Landau levels,"We study the radio-frequency diagonal conductivities of the anisotropic
stripe phases of higher Landau levels near half integer fillings. In the hard
direction, in which larger dc resistivity occurs, the spectrum exhibits a
striking resonance, while in the orthogonal, easy direction, no resonance is
discernable. The resonance is interpreted as a pinning mode of the stripe
phase.",0803.3228v1
2008-04-17,$0^{++}$ Resonances Observed at BES,"In last 10 years, $0^{++}$ resonances have been observed and studied at BES
in many processes, such as $J/\psi\to\gamma\pi^+\pi^-\pi^+\pi^-$,
$\gamma\pi^+\pi^-$, $\gamma\pi^0\pi^0$, $\gamma K^+K^-$, $\gamma K_SK_S$,
$\gamma\omega\phi$, $\omega\pi^+\pi^-$, $\omega K^+K^-$, $\phi\pi^+\pi^-$,
$\phi K^+K^-$, $\psi(2S)\to J/\psi\pi^+\pi^-$, $\chi_{c0}\to\pi^+\pi^-K^+K^-$,
$\pi^+\pi^-\pi^+\pi^-$ etc.. The results on $0^{++}$ resonances observed at BES
are reviewed.",0804.2756v1
2008-04-22,Distinction between sequential and direct three-body decays,"We discuss the three-body decay mechanisms of many-body resonances.
Sequential decays proceed via two-body configurations after emission of the
third particle. In direct decay all three particles leave simultaneously their
interaction regions. The intermediate paths within the interaction regions are
not observables and only accessible through models. The momentum distributions
carry, apart from polarization, all possible information about decay modes and
resonance structure. In this context we discuss detailed results for the decay
of the $^{9}$Be($5/2^-$) resonance.",0804.3608v1
2008-04-25,Observation of narrow Autler-Townes components in the resonant response of a dense atomic gas,"We have experimentally studied the reflection of a weak probe beam from a
dense atomic potassium vapor in the presence of a strong laser field tuned to
the atomic resonance transition. We have observed an Autler-Townes doublet
under hitherto unexplored conditions, namely that the Rabi frequency induced by
the strong laser field is much smaller than the self-broadened width of the
resonance transition of the unexcited vapor. We attribute our observation to a
reduction of the atomic decoherence by the strong drive field. We present a
theoretical model of nonlinear processes in a dense atomic gas to explain the
observed results.",0804.4151v1
2008-04-30,Tunable transmission and harmonic generation in nonlinear metamaterials,"We study the properties of a tunable nonlinear metamaterial operating at
microwave frequencies. We fabricate the nonlinear metamaterial composed of
double split-ring resonators and wires where a varactor diode is introduced
into each resonator so that the magnetic resonance can be tuned dynamically by
varying the input power. We show that at higher powers the transmission of the
metamaterial becomes power dependent, and we demonstrate experimentally
power-dependent transmission properties and selective generation of higher
harmonics.",0805.0028v2
2008-05-01,Resonances for a diffusion with small noise,"We study resonances for the generator of a diffusion with small noise in
$R^d$ :$ L_\epsilon = -\epsilon\Delta + \nabla F \cdot \nabla$, when the
potential F grows slowly at infinity (typically as a square root of the norm).
The case when F grows fast is well known, and under suitable conditions one can
show that there exists a family of exponentially small eigenvalues, related to
the wells of F . We show that, for an F with a slow growth, the spectrum is R+,
but we can find a family of resonances whose real parts behave as the
eigenvalues of the ""quick growth"" case, and whose imaginary parts are small.",0805.0106v1
2008-05-10,Resonant Tunneling through double-bended Graphene Nanoribbons,"We investigate theoretically resonant tunneling through double-bended
graphene nanoribbon structures, i.e., armchair-edged graphene nanoribbons
(AGNRs) in between two semi-infinite zigzag graphene nanoribbon (ZGNR) leads.
Our numerical results demonstrate that the resonant tunneling can be tuned
dramatically by the Fermi energy and the length and/or widths of the AGNR for
both the metallic and semiconductor-like AGNRs. The structure can also be use
to control the valley polarization of the tunneling currents and could be
useful for potential application in valleytronics devices.",0805.1438v1
2008-05-12,Resonances for non-analytic potentials,"We consider semiclassical Schroedinger operators on R^n, with C^\infty
potentials decaying polynomially at infinity. The usual theories of resonances
do not apply in such a non-analytic framework. Here, under some additional
conditions, we show that resonances are invariantly defined up to any power of
their imaginary part. The theory is based on resolvent estimates for families
of approximating distorted operators with potentials that are holomorphic in
narrow complex sectors around R^n.",0805.1596v1
2008-05-12,Chiral Symmetry of Nucleon Resonances in QCD sum rules,"The QCD sum rule approach is employed in order to study chiral properties of
positive- and negative-parity nucleon resonances. It is pointed out that
nucleons with an ``exotic'' chiral property, which can be represented by local
five-quark operators, can be paired with a standard nucleon forming a single
chiral multiplet. The sum rules of the five-quark operators, however, are shown
not to couple strongly to chirally-``exotic'' nucleon resonances at the mass
region of less than 2 GeV.",0805.1601v1
2008-05-13,Collisionless Absorption of Intense Laser Beams by Anharmonic Resonance,"Two decades after the invention of chirped pulse amplification the physical
mechanism of collisionless absorption of intense laser radiation in overdense
matter is still not sufficiently well understood. We show that anharmonic
resonance in the self-generated plasma potential of the single plasma layers
(cold plasma model) or of the individual electrons (warm plasma), respectively,
constitutes the leading physical mechanism of collisionless absorption in an
overdense plasma. Analogously to collisions, resonance provides for the finite
phase shift of the free electron current relative to the driving laser field
which is compulsory for energy transfer from the laser beam to any medium. An
efficient new scenario of wave breaking is also indicated.",0805.1815v1
2008-05-15,Spectral densities of superconducting qubits with environmental resonances,"In this paper we derive the environmental spectral density for flux, phase
and charge qubits when each of them is coupled to an environment with a
resonance. From the spectral density we obtain the characteristic spontaneous
emission (relaxation) lifetimes $T_1$ for each of these qubits, and show that
there is a substantial enhancement of $T_1$ beyond the resonant frequency of
the environment.",0805.2419v1
2008-05-28,A common model for superluminal propagation in absorbing atomic media and lossy metastructures,"We analyse the superluminal propagation of narrow-band pulses at resonances
in dissipative media. The output waveform is an attenuated, undistorted,
time-advanced version of the input which can be interpreted as the result of
the interference of two scaled replicas of the input having a positive relative
delay. The proposed analysis applies both to the propagation in a passive bulk
medium at an electronic resonance and in a dielectric waveguide coupled to a
lossy micro-ring resonator. This latter case provides a clear insight of the
underlying physical phenomena.",0805.4240v2
2008-06-09,Quark-Model Identification of Baryon Ground and Resonant States,"We present a new classification scheme of baryon ground states and resonances
into SU(3) flavor multiplets. The scheme is worked out along a covariant
formalism with relativistic constituent quark models and it relies on detailed
investigations of the baryon spectra, the spin-flavor structure of the baryon
eigenstates, the behaviour of their probability density distributions as well
as covariant predictions for mesonic decay widths. The results are found to be
quite independent of the specific types of relativistic constituent quark
models employed. It turns out that a consistent classification requires to
include also resonances that are presently reported from experiment with only
two-star status.",0806.1454v1
2008-06-13,Resonant Plasmon-Soliton Interaction,"We describe an effective resonant interaction between two localized wave
modes of different nature: a plasmon-polariton at a metal surface and a
self-focusing beam (spatial soliton) in a non-linear dielectric medium.
Propagating in the same direction, they represent an exotic coupled-waveguide
system, where the resonant interaction is controlled by the soliton amplitude.
This non-linear system manifests hybridized plasmon-soliton eigenmodes, mutual
conversion, and non-adiabatic switching, which offer exciting opportunities for
manipulation of plasmons via spatial solitons.",0806.2183v2
2008-06-17,Input Impedance and Gain of a Gigahertz Amplifier Using a DC SQUID in a Quarter Wave Resonator,"Due to their superior noise performance, SQUIDs are an attractive alternative
to high electron mobility transistors for constructing ultra-low-noise
microwave amplifiers for cryogenic use. We describe the use of a lumped element
SQUID inductively coupled to a quarter wave resonator. The resonator acts as an
impedance transformer and also makes it possible for the first time to
accurately measure the input impedance and intrinsic microwave characteristics
of the SQUID. We present a model for input impedance and gain, compare it to
the measured scattering parameters, and describe how to use the model for the
systematic design of low-noise microwave amplifiers with a wide range of
performance characteristics.",0806.2853v1
2008-06-19,Measurement-induced entanglement of two superconducting qubits,"We study the problem of two superconducting quantum qubits coupled via a
resonator. If only one quanta is present in the system and the number of
photons in the resonator is measured with a null result, the qubits end up in
an entangled Bell state. Here we look at one source of errors in this quantum
nondemolition scheme due to the presence of more than one quanta in the
resonator, previous to the measurement. By analyzing the structure of the
conditional Hamiltonian with arbitrary number of quanta, we show that the
scheme is remarkably robust against these type of errors.",0806.3148v1
2008-06-19,On Transmission Line Resonances in High T$_C$ dc SQUIDs,"In this paper, we study transmission line resonances in high $T_C$ dc SQUIDs.
These resonances are exhibited in the characteristics of SQUIDs which are
fabricated on substrates with high dielectric constant, such as strontium
titanate. The power balance equation is analytically derived both for symmetric
and asymmetric SQUIDs. Using this, we investigate SQUID current - voltage
$I(V)$, voltage - flux $V(\Phi)$ and voltage modulation $\Delta V$
characteristics.",0806.3187v1
2008-06-21,Towards isotropic negative magnetics in the visible range,"The idea of isotropic resonant magnetism in the visible range of frequencies
known from precedent publications is developed having in mind achievements of
the modern chemistry. Plasmonic colloidal nanoparticles covering a silica core
form a cluster with resonant and isotropic magnetic response. Two approximate
models giving the qualitative mutual agreement are used to evaluate the
magnetic polarizability of the cluster. It is shown that the electrostatic
interaction of nanocolloids decreases the resonant frequency of an individual
complex magnetic scatterer (nanocluster) compared to the previously studied
variant of a planar circular nanocluster with same size. This means the
reduction of the optical size of nanoclusters that presumably allows one to
avoid strong spatial dispersion within the frequency range of the negative
permeability.",0806.3512v1
2008-06-21,Laboratory performances of the solar multichannel resonant scattering spectrometer prototype of the GOLF-New Generation instrument,"This article quickly summarizes the performances and results of the GOLF/SoHO
resonant spectrometer, thus justifying to go a step further. We then recall the
characteristics of the multichannel resonant GOLF-NG spectrometer and present
the first successful performances of the laboratory tests on the prototype and
also the limitations of this first technological instrument. Scientific
questions and an observation strategy are discussed.",0806.3521v1
2008-06-24,Low-energy resonances and bound states of aligned bosonic and fermionic dipoles,"The low-energy scattering properties of two aligned identical bosonic and
identical fermionic dipoles are analyzed. Generalized scattering lengths are
determined as functions of the dipole moment and the scattering energy. Near
resonance, where a new bound state is being pulled in, all non-vanishing
generalized scattering lengths diverge, with the $a_{00}$ and $a_{11}$
scattering lengths being dominant for identical bosons and identical fermions,
respectively, near both broad and narrow resonances. Implications for the
energy spectrum and the eigenfunctions of trapped two-dipole systems and for
pseudo-potential treatments are discussed.",0806.3991v1
2008-08-05,Electric-Field-Induced Nuclear Spin Resonance Mediated by Oscillating Electron Spin Domains in GaAs-Based Semiconductors,"We demonstrate an alternative nuclear spin resonance using radio frequency
(RF) electric field (nuclear electric resonance: NER) instead of magnetic
field. The NER is based on the electronic control of electron spins forming a
domain structure. The RF electric field applied to a gate excites spatial
oscillations of the domain walls and thus temporal oscillations of the
hyperfine field to nuclear spins. The RF power and burst duration dependence of
the NER spectrum provides insight into the interplay between nuclear spins and
the oscillating domain walls.",0808.0538v1
2008-08-12,Resonant Transmission of Electromagnetic Fields through Subwavelength Zero-$ε$ Slits,"We theoretically investigate the transmission of electromagnetic radiation
through a metal plate with a zero-$\epsilon$ metamaterial slit, where the
permittivity tends towards zero over a given bandwidth. Our analytic results
demonstrate that the transmission coefficient can be substantial for a broad
range of slit geometries, including subwavelength widths that are many
wavelengths long. This novel resonant effect has features quite unlike the
Fabry-P\'{e}rot-like resonances that have been observed in conductors with deep
channels. We further reveal that these high impedance ultranarrow
zero-$\epsilon$ channels can have significantly {\it greater} transmission
compared to slits with no wave impedance difference across them.",0808.1635v1
2008-08-14,Extremely short-length surface plasmon resonance sensors,"The impact of the system design on the control of coupling between planar
waveguide modes and surface plasmon polaritons (SPP) is analyzed. We examine
how the efficiency of the coupling can be enhanced by an appropriate
dimensioning of a multi-layer device structure without using additional
gratings. We demonstrate that by proper design the length of the device can be
dramatically reduced through fabrication a surface plasmon resonance sensor
based on the SPP-photon transformation rather then on SPP dissipation.",0808.1966v1
2008-08-15,Resonance parameters from K-matrix and T-matrix poles,"We extract K-matrix poles from our fits to elastic pion-nucleon scattering
and eta-nucleon production data in order to test a recently proposed method for
the determination of resonance properties, based on the trace of the K-matrix.
We have considered issues associated with the separation of background and
resonance contributions, the correspondence between K-matrix and T-matrix
poles, and the complicated behavior of eigenphases.",0808.2176v2
2008-08-23,Spin-isospin resonances: A self-consistent covariant description,"For the first time a fully self-consistent charge-exchange relativistic RPA
based on the relativistic Hartree-Fock (RHF) approach is established. The
self-consistency is verified by the so-called isobaric analog state (IAS)
check. The excitation properties and the non-energy weighted sum rules of two
important charge-exchange excitation modes, the Gamow-Teller resonance (GTR)
and the spin-dipole resonance (SDR), are well reproduced in the doubly magic
nuclei $^{48}$Ca, $^{90}$Zr and $^{208}$Pb without readjustment of the
particle-hole residual interaction. The dominant contribution of the exchange
diagrams is demonstrated.",0808.3159v1
2008-08-26,Pattern selection in parametrically-driven arrays of nonlinear resonators,"We study the problem of pattern selection in an array of
parametrically-driven nonlinear resonators with application to
microelectromechanical and nanoelectromechanical systems (MEMS & NEMS), using
an amplitude equation recently derived by Bromberg, Cross, and Lifshitz [PRE
73, 016214 (2006)]. We describe the transitions between standing-wave patterns
of different wave numbers as the drive amplitude is varied either
quasistatically, abruptly, or as a linear ramp in time. We find novel
hysteretic effects, which are confirmed by numerical integration of the
original equations of motion of the interacting nonlinear resonators.",0808.3589v1
2008-08-29,Trace Element Analysis of Potassium by Resonance Ionization Mass Spectrometry,"A simple resonance ionization mass spectrometer is built with a Quadrupole
Mass Spectrometer (QMS) and two laser diodes aiming at trace analysis of
potassium. The overall detection efficiency is estimated comparing the yields
of resonance ionization and electron-impact ionization in the same QMS. A clear
discrimination of $^{39}\rm K$, $^{40}\rm K$ and $^{41}\rm K$ is demonstrated
with a help of isotope shifts of the atomic levels.",0808.4020v2
2008-09-01,"Search for High-Mass Resonances Decaying into Leptons of Different Flavor ($eμ$, $eτ$, $μτ$)","We present a search for high-mass resonances decaying into two leptons of
different flavor: $e\mu$, $e\tau$ and $\mu\tau$. These resonances are predicted
by several models for Physics Beyond the Standard Model, such as
R-parity-violating MSSM. The search is based on 1 ${\rm fb^{-1}}$ of Tevatron
Run II data collected with the CDF detector at $\sqrt{s}$ = 1.96 TeV in proton
anti-proton collisions.",0809.0296v1
2008-09-13,Generalized Mean Field Approach to a Resonant Bose-Fermi Mixture,"We formulate a generalized mean-field theory of a mixture of fermionic and
bosonic atoms, in which the fermion-boson interaction can be controlled by a
Feshbach resonance. The theory correctly accounts for molecular binding
energies of the molecules in the two-body limit, in contrast to the most
straightforward mean-field theory. Using this theory, we discuss the
equilibrium properties of fermionic molecules created from atom pairs in the
gas. We also address the formation of molecules when the magnetic field is
ramped across the resonance, and present a simple Landau-Zener result for this
process.",0809.2354v1
2008-09-16,Resonance solutions of the nonlinear Schrödinger equation in an open double-well potential,"The resonance states and the decay dynamics of the nonlinear Schr\""odinger
(or Gross-Pitaevskii) equation are studied for a simple, however flexible model
system, the double delta-shell potential. This model allows analytical
solutions and provides insight into the influence of the nonlinearity on the
decay dynamics. The bifurcation scenario of the resonance states is discussed,
as well as their dynamical stability properties. A discrete approximation using
a biorthogonal basis is suggested which allows an accurate description even for
only two basis states in terms of a nonlinear, nonhermitian matrix problem.",0809.2748v1
2008-09-21,Stochastic Resonance in the Fermi-Pasta-Ulam Chain,"We consider a damped $\beta$-Fermi-Pasta-Ulam chain, driven at one boundary
subjected to stochastic noise. It is shown that, for a fixed driving amplitude
and frequency, increasing the noise intensity, the system's energy resonantly
responds to the modulating frequency of the forcing signal. Multiple peaks
appear in the signal to noise ratio, signalling the phenomenon of stochastic
resonance. The presence of multiple peaks is explained by the existence of many
stable and metastable states that are found when solving this boundary value
problem for a semi-continuum approximation of the model. Stochastic resonance
is shown to be generated by transitions between these states.",0809.3604v1
2008-09-22,Resonant-tunnelling-assisted crossing for subwavelength plasmonic slot waveguides,"We theoretically investigate the properties of crossing for two perpendicular
subwavelength plasmonic slot waveguides. We show that, when encountering nano
intersection, the crosstalk for the direct crossing is around 25%, almost same
as throughout. In terms of symmetry considerations and resonant-tunnelling
effect, we design compact cavity-based structures. Our results show that the
crosstalk is eliminated and the throughput reaches the unity on resonance.
Simulations results are in agreement with those from the coupled-model theory.
When taking into account of the material loss, due to the unchanged symmetry
properties of the modes, the crosstalk is still suppressed. Our results may
open a way to construct nanoscale crossings for high-density nanoplasmonic
integration circuits.",0809.3645v1
2008-09-24,Nonlinear properties of split-ring resonators,"In this letter, the properties of split-ring resonators (SRRs) loaded with
high-Q capacitors and nonlinear varactors are theoretically analyzed and
experimentally measured. We demonstrate that the resonance frequency $f_m$ of
the nonlinear SRRs can be tuned by increasing the incident power. $f_m$ moves
to lower and higher frequencies for the SRR loaded with one varactor and two
back-to-back varactors, respectively. For high incident powers, we observe
bistable tunable metamaterials and hysteresis effects. Moreover, the coupling
between two nonlinear SRRs is also discussed.",0809.4045v1
2008-09-25,Ground state cooling of nanomechanical resonator via parametric linear coupling,"We present a ground state cooling scheme for a nanomechanical resonator
linearly coupled with a LC oscillator. The linear coupling, when periodically
modulated at red detuning, up-converts the low-frequency nanomechanical mode to
the high-frequency LC oscillator mode and generates backaction force that can
cool the resonator to its ground state in the resolved-sideband regime. We also
study the effect of the quantum backaction noise on the cooling due to the
counter rotating term in the linear coupling. The scheme can be compared with
laser cooling for the atomic systems and can be realized in superconducting
circuits.",0809.4459v2
2008-09-27,Bounds on Lorentz and CPT Violation from the Earth-Ionosphere Cavity,"Electromagnetic resonant cavities form the basis of many tests of Lorentz
invariance involving photons. The effects of some forms of Lorentz violation
scale with cavity size. We investigate possible signals of violations in the
naturally occurring resonances formed in the Earth-ionosphere cavity.
Comparison with observed resonances places the first terrestrial constraints on
coefficients associated with dimension-three Lorentz-violating operators at the
level of 10^{-20} GeV.",0809.4801v1
2008-10-14,Investigation of Vertical Spiral Resonators for Low Frequency Metamaterial Design,"This paper thoroughly explores the characteristics of vertical spiral
resonators (VSR). They exhibit rela-tively high Q factors and sizes around a
few percent of the free space wavelength, which make them ideal candi-dates for
assembling metamaterial devices. A quasistatic model of VSR is obtained from
simple analytical ex-pressions, and the effects of certain geometrical
parameters on the resonant frequency are investigated.",0810.2485v1
2008-10-16,Faddeev-Merkuriev integral equations for atomic three-body resonances,"Three-body resonances in atomic systems are calculated as complex-energy
solutions of Faddeev-type integral equations. The homogeneous Faddeev-Merkuriev
integral equations are solved by approximating the potential terms in a
Coulomb-Sturmian basis. The Coulomb-Sturmian matrix elements of the three-body
Coulomb Green's operator has been calculated as a contour integral of two-body
Coulomb Green's matrices. This approximation casts the integral equation into a
matrix equation and the complex energies are located as the complex zeros of
the Fredholm determinant. We calculated resonances of the e-Ps system at higher
energies and for total angular momentum L=1 with natural and unnatural parity",0810.3036v1
2008-10-17,Microwave Photoresistance in dc-driven 2D Systems at Cyclotron Resonance Subharmonics,"We study microwave photoresistivity oscillations in a high mobility
two-dimensional electron system subject to strong dc electric fields. We find
that near the second subharmonic of the cyclotron resonance the frequency of
the resistivity oscillations with dc electric field is twice the frequency of
the oscillations at the cyclotron resonance, its harmonics, or in the absence
of microwave radiation. This observation is discussed in terms of the
microwave-induced sidebands in the density of states and the interplay between
different scattering processes in the separated Landau level regime.",0810.3257v1
2008-10-27,Alternating current driven instability in magnetic junctions,"An effect is considered of alternating (high-frequency) current on the
spin-valve type magnetic junction configuration. The stability with respect to
small fluctuations is investigated in the macrospin approximation. When the
current frequency is close to the eigenfrequency (precession frequency) of the
free layer, parametric resonance occurs. Both collinear configurations,
antiparallel and parallel ones, can become unstable under resonance conditions.
The antiparallel configuration can become unstable under non-resonant
conditions, also. The threshold current density amplitude is of the order of
the dc current density switching the magnetic junction.",0810.4753v1
2008-10-28,Free-space Excitation of Resonant Cavities formed from Cloaking Metamaterial,"We propose a new class of resonant electromagnetic structures, and study
their response to free-space illumination. The structures consist of partial
cylindrical shells that have cloaking material properties proposed by Pendry et
al. These metamaterial shells have apertures that allow the propagation of
incident irradiation into an interior resonant cavity. We use full wave
time-harmonic analysis to study the field distribution inside the cavity, and
show that an analogue of Whispering Gallery Modes (WGMs) can be efficiently
excited via free-space illumination.",0810.4961v1
2008-10-29,Discrete Coordinate Scattering Approach to Nano-optical Resonance,"In this letter, we investigate the coherent tunneling process of photons
between a defected circular resonator and a waveguide based on the recently
developed discrete coordinate scattering methods (L. Zhou et al., Phys. Rev.
Lett. 101, 100501 (2008)). We show the detailed microscopic mechanism of the
tunneling and present a simple model for defect coupling in the resonator. The
Finite-Difference Time-Domain(FDTD) numerical results is explored to illustrate
the analysis results.",0810.5173v1
2008-11-06,Nonlinear Dynamics and Chaos in Two Coupled Nanomechanical Resonators,"Two elastically coupled nanomechanical resonators driven independently near
their resonance frequencies show intricate nonlinear dynamics. The dynamics
provide a scheme for realizing a nanomechanical system with tunable frequency
and nonlinear properties. For large vibration amplitudes the system develops
spontaneous oscillations of amplitude modulation that also show period doubling
transitions and chaos. The complex nonlinear dynamics are quantitatively
predicted by a simple theoretical model.",0811.0870v2
2008-11-06,Andreev reflection through Fano resonances in molecular wires,"We study Andreev reflection in a normal conductor-molecule-superconductor
junction using a first principles approach. In particular, we focus on a family
of molecules consisting of a molecular backbone and a weakly coupled side
group. We show that the presence of the side group can lead to a Fano resonance
in the Andreev reflection. We use a simple theoretical model to explain the
results of the numerical calculations and to make predictions about the
possible sub-gap resonance structures in the Andreev reflection coefficient.",0811.0950v1
2008-11-08,"Obsevation of exotic resonances for K0(short)pi,K0(short)p and K0(short)Lambda spectra in p+A collisions at 10 GeV/c","The review on the 2m propane bubble chamber experiment data analysis aimed to
searches for an exotic baryon states for $K^0_s$-meson subsystems. The
observation of $\Sigma^0$, $\Sigma^{*+}$(1385) and $K^{*\pm}$(892) well known
resonances from PDG are a good tests of this method. There are found a resonant
structures for $K^0_s\pi^{\pm}$, $K^0_s$p and $K^0_s\Lambda$ invariant mass
spectra which were interpreted as $\kappa$(720)-meson, $\Theta^+(1540)$-baryon
and $N^0(1750)$ or $\Xi^0$-baryon states, respectively.",0811.1275v2
2008-11-26,Scattering Resonances in a Degenerate Fermi Gas,"We consider elastic single-particle scattering from a one-dimensional
two-component trapped superfluid Fermi gas when the incoming projectile
particle is identical to one of the confined species. Our theoretical treatment
is based on the Hartree-Fock ground state of the trapped gas and a
configuration-interaction description of the excitations. We determine the
scattering phase shifts for the system and predict Fano-type scattering
resonances that are a direct consequence of inter-atomic pairing. We describe
the main characteristics of the scattering resonances and make a comparison
with the results of BCS mean-field theory.",0811.4284v1
2008-12-01,Cooling a micro-mechanical resonator by quantum back-action from a noisy qubit,"We study the role of qubit dephasing in cooling a mechanical resonator by
quantum back-action. With a superconducting flux qubit as a specific example,
we show that ground-state cooling of a mechanical resonator can only be
realized if the qubit dephasing rate is sufficiently low.",0812.0261v2
2008-12-25,Note on the 2-component Analogue of 2-dimensional Long Wave-Short Wave Resonance Interaction System,"An integrable two-component analogue of the two-dimensional long wave-short
wave resonance interaction (2c-2d-LSRI) system is studied. Wronskian solutions
of 2c-2d-LSRI system are presented. A reduced case, which describes resonant
interaction between an interfacial wave and two surface wave packets in a two
layer fluid, is also discussed.",0812.4591v1
2009-01-02,Quantum Resonance near Optimal Eavesdropping in Quantum Cryptography,"We find a resonance behavior in the disturbance when an eavesdropper chooses
a near-optimal strategy intentionally or unintentionally when the usual
Bennett-Brassard cryptographic scheme is performed between two trusted parties.
This phenomenon tends to disappear when eavesdropping strategy moves far from
the optimal one. Therefore, we conjecture that this resonant effect is a
characteristic for the eavesdropping strategy near to optimal one. We argue
that this effect makes the quantum cryptography more secure against the
eavesdropper's attack.",0901.0237v1
2009-01-04,Coupling between a dark and a bright eigenmode in a terahertz metamaterial,"Terahertz time domain spectroscopy and rigorous simulations are used to probe
the coupling between a dark and a bright plasmonic eigenmode in a metamaterial
with broken symmetry. The metamaterial consists of two closely spaced split
ring resonators that have their gaps in non-identical positions within the
ring. For normal incidence and a fixed polarization both lowest order
eigenmodes of the split ring resonators can be excited; although one of them
has to be regarded as dark since coupling is prohibited because of symmetry
constraints. Emphasis in this work is put on a systematic evaluation of the
coupling effects depending on a spectral tuning of both resonances.",0901.0365v1
2009-01-12,Fermi-edge Singularity in II-VI Semiconductor Resonant Tunneling Structures,"We report on the observation of Fermi edge enhanced resonant tunneling
transport in a II-VI semiconductor heterostructure. The resonant transport
through a self assembled CdSe quantum dot survives up to 45 K and probes a
disordered two dimensional (2D) like emitter which dominates the magnetic field
dependence of the transport. An enhancement of the tunnel current through many
particle effects is clearly observable, even without an applied magnetic field.
Additional fine structure in the tunneling current suggests that while
conventional Fermi edge singularity theory successfull reproduces the general
features of the increased transmission, it is not adequate to describe all
details of the current enhancement.",0901.1568v1
2009-01-13,Search for resonant diphoton production with the D0 detector,"We present a search for a narrow resonance in the inclusive diphoton final
state using 2.7 fb-1 of data collected with the D0 detector at the Fermilab
Tevatron ppbar Collider. We observe good agreement between the data and the
background prediction, and set the first 95% C.L. upper limits on the
production cross section times the branching ratio for decay into a pair of
photons for resonance masses between 100 and 150 GeV. This search is also
interpreted in the context of several models of electroweak symmetry breaking
with a Higgs boson decaying into two photons.",0901.1887v2
2009-01-20,Intermode Dephasing in a Superconducting Stripline Resonator - Supplementary Information,"Supplementary information for the article ""Intermode Dephasing in a
Superconducting Stripline Resonator"" (arXiv:0901.3110). The supplementary
information is devoted to three main issues. In section I we describe the
fabrication process; in section II we present the derivation of the Hamiltonian
of the system and provide a more detailed discussion about the properties of
the microbridges; in section III the hysteretic response of the resonator and
the effect of heating are discussed.",0901.3133v1
2009-02-09,String resonances at the Large Hadron Collider,"The Large Hadron Collider promises to discover new physics beyond the
Standard Model. An exciting possibility is the formation of string resonances
at the TeV scale. In this article, we show how string resonances may be
detected at the LHC in the $pp\to\gamma+jet$ channel. Our study is based on
event shape variables, missing energy and momentum, maximum transverse momentum
of photons and dijet invariant mass. These observables provide interesting
signatures which enable us to discriminate string events from the Standard
Model background.",0902.1473v1
2009-02-15,Resonances Do Not Equilibrate,"We discuss, in qualitative and quantitative fashion, the yields of hadron
resonances. We show that these yields, in general, are not in chemical
equilibrium. We evaluate the non-equilibrium abundances in a dynamic model
implementing the $1+2\leftrightarrow 3$ resonance formation reactions. Due to
the strength of these reactions, we show the $\Sigma(1385)$ enhancement, and
the $\Lambda(1520)$ suppression explicitly.",0902.2550v1
2009-02-16,Control of Transport-barrier relaxations by Resonant Magnetic Perturbations,"Transport-barrier relaxation oscillations in the presence of resonant
magnetic perturbations are investigated using three-dimensional global fluid
turbulence simulations from first principles at the edge of a tokamak. It is
shown that resonant magnetic perturbations have a stabilizing effect on these
relaxation oscillations and that this effect is due mainly to a modification of
the pressure profile linked to the presence of both residual residual magnetic
island chains and a stochastic layer.",0902.2710v1
2009-02-16,Vapor pressure dependence of spectral width of EIT in Lambda-level cesium molecular system,"We have studied electromagnetically induced transparency (EIT) in diatomic
cesium molecules in a vapor cell by using tunable diode lasers. We have
observed a sub-natural Lambda-resonance in an absorption molecular band at
different cesium vapor pressures. The width of the EIT resonance shows a linear
dependence on cesium vapor pressure. Narrow Lambda-resonances in molecules can
be used as frequency references for femtosecond laser frequency combs.",0902.2745v1
2009-02-18,Dynamically generated resonances from the vector octet-baryon decuplet interaction,"We study the interaction of the octet of vector mesons with the decuplet of
baryons using Lagrangians of the hidden gauge theory for vector interactions.
The unitary amplitudes in coupled channels develop poles that can be associated
with some known baryonic resonances, while there are predictions for new ones
at the energy frontier of the experimental research. The work offers guidelines
on how to search for these resonances.",0902.3150v2
2009-02-23,On the Spectrum of the Resonant Quantum Kicked Rotor,"It is proven that none of the bands in the quasi-energy spectrum of the
Quantum Kicked Rotor is flat at any primitive resonance of any order.
Perturbative estimates of bandwidths at small kick strength are established for
the case of primitive resonances of prime order. Different bands scale with
different powers of the kick strength, due to degeneracies in the spectrum of
the free rotor.",0902.3896v2
2009-02-24,Optical potentials using resonance states in Supersymmetric Quantum Mechanics,"Complex potentials are constructed as Darboux-deformations of short range,
radial nonsingular potentials. They behave as optical devices which both
refracts and absorbs light waves. The deformation preserves the initial
spectrum of energies and it is implemented by means of a Gamow-Siegert function
(resonance state). As straightforward example, the method is applied to the
radial square well. Analytical derivations of the involved resonances show that
they are `quantized' while the corresponding wave-functions are shown to behave
as bounded states under the broken of parity symmetry of the related
one-dimensional problem.",0902.4052v1
2009-02-25,Searching for exotic states in the $N πK $ system,"We study the $N \pi K$ system in order to investigate the possibility of
existence of strangeness +1 resonance(s). The formalism consists of solving the
Faddeev equations with the $N \pi$, $\pi K $ and $K N$ $t$-matrices obtained
from chiral dynamics. The same formalism, which leads to the finding of several
$1/2^+$ resonances in the corresponding three-body $S$ = -1 channels in the
1400-2000 MeV energy region, results into only one broad bump around 1700 MeV
with isospin 0. The amplitudes in isospin 1 and 2 configuration do not have any
resonant structure.",0902.4425v1
2009-03-02,Sommerfeld enhancement for a Yukawa potential,"We show how easy it is to get the Sommerfeld enhancement for a Yukawa
potential, for definite partial waves, beyond the S wave analyzed in previous
literature. In particular, we report results for the P wave (for which there is
a resonant pattern and the enhancement can be of several orders of magnitude
even far from the resonance) that could be relevant for the analysis of
experimental cosmic rays data possibly signaling the annihilation of dark
matter particles.",0903.0317v2
2009-03-05,Theoretical analysis of mechanical displacement measurement using a multiple cavity mode transducer,"We present an optomechanical displacement transducer, that relies on three
cavity modes parametrically coupled to a mechanical oscillator and whose
frequency spacing matches the mechanical resonance frequency. The additional
resonances allow to reach the standard quantum limit at substantially lower
input power (compared to the case of only one resonance), as both, sensitivity
and quantum backaction are enhanced. Furthermore, it is shown that in the case
of multiple cavity modes, coupling between the modes is induced via reservoir
interaction, e.g., enabling quantum backaction noise cancellation. Experimental
implementation of the schemes is discussed in both the optical and microwave
domain.",0903.1013v2
2009-03-11,Accretion disk warping by resonant relaxation: The case of maser disk NGC4258,"The maser disk around the massive black hole (MBH) in active galaxy NGC 4258
exhibits an O(10 deg) warp on the O(0.1 pc) scale. The physics driving the warp
are still debated. Suggested mechanisms include torquing by relativistic frame
dragging or by radiation pressure. We propose here a new warping mechanism:
resonant torquing of the disk by stars in the dense cusp around the MBH. We
show that resonant torquing can induce such a warp over a wide range of
observed and deduced physical parameters of the maser disk.",0903.2051v2
2009-03-11,Search for narrow resonances lighter than $Υ$ mesons,"We report a search for narrow resonances, produced in $p\bar{p}$ collisions
at $\sqrt{s}=1.96$ TeV, that decay into muon pairs with invariant mass between
6.3 and 9.0 GeV/c^2. The data, collected with the CDF~II detector at the
Fermilab Tevatron collider, correspond to an integrated luminosity of 630
pb$^{-1}$. We use the dimuon invariant mass distribution to set 90% upper
credible limits of about 1% to the ratio of the production cross section times
muonic branching fraction of possible narrow resonances to that of the
$\Upsilon(1{\rm S})$ meson.",0903.2060v1
2009-03-23,Feshbach Resonance Induced Fano Interference in Photoassociation,"We consider photoassociation from a state of two free atoms when the
continuum state is close to a magnetic field induced Feshbach resonance and
analyze Fano interference in photoassociation. We show that the minimum in
photoassociation profiles characterized by the Fano asymmetry parameter $q$ is
independent of laser intensity, while the maximum explicitly depends on laser
intensity. We further discuss the possibility of nonlinear Fano effect in
photoassociation near a Feshbach resonance.",0903.3799v2
2009-03-25,Light reflection from a metal surface with subwavelength cavities,"The interaction of light with the localized/delocalized system, i.e., a metal
surface with rectangular cavities of finite depth, has been studied. Reflection
spectrum has been measured in the optical frequencies and resonant minima have
been observed. We have developed an analytical model, which agrees well with
the experiment. The localized waveguide resonance and delocalized surface
resonance have been identified and discussed. The results may be useful for
manipulating the coupling between light and matters.",0903.4252v1
2009-04-05,Controlling photonic structures using optical forces,"The downscaling of optical systems to the micro and nano-scale results in
very compliant systems with nanogram-scale masses, which renders them
susceptible to optical forces. Here we show a specially designed resonant
structure for enabling efficient static control of the optical response with
relatively weak repulsive and attractive optical forces. Using attractive
gradient optical forces we demonstrate a static mechanical deformation of up to
20 nanometers in the resonator structure. This deformation is enough to shift
the optical resonances by roughly 80 optical linewidths.",0904.0794v2
2009-04-11,Coupled Superconducting Phase and Ferromagnetic Order Parameter Dynamics,"Via a direct coupling between the magnetic order parameter and the singlet
Josephson supercurrent, we detect spin-wave resonances, and their dispersion,
in ferromagnetic Josephson junctions in which the usual insulating or metallic
barrier is replaced with a weak ferromagnet. The coupling arises within the
Fraunhofer interferential description of the Josephson effect, because the
magnetic layer acts as a time dependent phase plate. A spin-wave resonance at a
frequency ws implies a dissipation that is reflected as a depression in the
current-voltage curve of the Josephson junction when hbar ws = 2eV. We have
thereby performed a resonance experiment on only 10^7 Ni atoms.",0904.1780v1
2009-04-13,Localization of resonance eigenfunctions on quantum repellers,"We introduce a new phase space representation for open quantum systems. This
is a very powerful tool to help advance in the study of the morphology of their
eigenstates. We apply it to two different versions of a paradigmatic model, the
baker map. This allows to show that the long-lived resonances are strongly
scarred along the shortest periodic orbits that belong to the classical
repeller. Moreover, the shape of the short-lived eigenstates is also analyzed.
Finally, we apply an antiunitary symmetry measure to the resonances that
permits to quantify their localization on the repeller.",0904.2015v1
2009-04-14,Resonant active-sterile neutrino mixing in the presence of matter potentials and altered dispersion relations,"We investigate resonant active-sterile neutrino oscillations emergent from
the interplay between matter, CPT- and Lorentz-violating coefficients with
different energy dependences. Novel and experimentally accessible resonant
neutrino oscillation phenomenologies are predicted and possible implications
for observed, but yet unexplained, neutrino oscillation anomalies such as LSND
and MiniBooNE are discussed.",0904.2167v2
2009-04-25,Mach-Zehnder-Fano interferometer,"We introduce a concept of the Mach-Zehnder-Fano interferometer by inserting a
cavity exhibiting Fano resonance into a conventional interferometer. By
employing the scattering-matrix approach, we demonstrate that the transmission
is sensitive to a position of the cavity such that an asymmetric structure
exhibits a series of narrow resonances with almost perfect reflection. We
discuss how to implement this novel geometry in two-dimensional photonic
crystals and use direct numerical simulations to demonstrate novel regimes of
the resonant transmission and reflection.",0904.3985v3
2009-04-30,Dynamically generated resonances from the interaction of vector mesons with baryons,"We present the results of the first calculations involving the interaction of
vector mesons with baryons, by means of which one generates a large amount of
dynamically generated resonances, many of which can be associated to known
resonances, while others represent predictions for new states.",0904.4804v1
2009-05-06,Ultracold three-body collisions near overlapping Feshbach resonances,"We present a comprehensive collection of ultracold three-body collisions
properties near overlapping Feshbach resonances. Our results incorporate
variations of all scattering lengths and demonstrate novel collisional
behavior, such as atom-molecule interference effects. Taking advantage of the
unique ways in which these collisions reflect Efimov physics, new pathways to
control atomic and molecular losses open up. Further, we show that overlapping
resonances can greatly improve the chances of observing multiple Efimov
features in an ultracold quantum gas for nearly any system.",0905.0772v2
2009-05-07,Dynamically generated resonances from the vector octet-baryon octet interaction,"We study the interaction of vector mesons with the octet of stable baryons in
the framework of the local hidden gauge formalism using a coupled channels
unitary approach. We examine the scattering amplitudes and their poles, which
can be associated to known J^P=1/2^-,3/2^- baryon resonances, in some cases, or
give predictions in other ones. The formalism employed produces doublets of
degenerate J^P=1/2^-,3/2^- states, a pattern which is observed experimentally
in several cases. The findings of this work should also be useful to guide
present experimental programs searching for new resonances, in particular in
the strange sector where the current information is very poor.",0905.0973v1
2009-05-08,Variational study of the neutron resonance mode in the cuprate superconductors,"A Gutzwiller-type variational wave function is proposed for the neutron
resonance mode in the cuprate superconductors. An efficient re-weighting
technique is devised to perform variational Monte Carlo simulation on the
proposed wave function which is composed of linearly superposed Gutzwiller
projected Slater determinants. The calculation, which involves no free
parameter, predicts qualitatively correct behavior for both the energy and the
spectral weight of the resonance mode as functions of doping.",0905.1232v1
2009-05-14,A compact apparatus for studies of element and phase-resolved ferromagnetic resonance,"We present a compact sample holder equipped with electromagnets and high
frequency transmission lines; the sample holder is intended for combined x-ray
magnetic circular dichroism (XMCD) and ferromagnetic resonance measurements
(FMR). Time-resolved measurements of resonant x-ray detected FMR during forced
precession are enabled by use of a rf excitation that is phase-locked to the
storage ring bunch clock. Several applications of the combined XMCD + FMR
technique are presented, demonstrating the flexibility of the experimental
design.",0905.2353v1
2009-05-21,Creating traveling waves from standing waves from the gyrotropic paramagnetic properties of Fe$^{3+}$ ions in a high-Q whispering gallery mode sapphire resonator,"We report observations of the gyrotropic change in magnetic susceptibility of
the Fe$^{3+}$ electron paramagnetic resonance at 12.037GHz (between spin states
$|1/2>$ and $|3/2>$) in sapphire with respect to applied magnetic field.
Measurements were made by observing the response of the high-Q Whispering
Gallery doublet (WGH$_{\pm17,0,0}$) in a Hemex sapphire resonator cooled to 5
K. The doublets initially existed as standing waves at zero field and were
transformed to traveling waves due to the gyrotropic response.",0905.3435v1
2009-05-22,Bound and resonance electron states in the monolayer graphene with the short-range impurities,"Bound and resonance electronic states in impure graphene are studied.
Short-range perturbations for defects and impurities of the types ""local
chemical potential"" and ""local gap"" are taken into account. Zero gap and
non-zero gap kinds of graphene are considered. A qualitative analysis of the
electronic spectrum general features and numeric calculations are presented. A
dependence of the resonance widths on the gap value, angular momentum values
and the perturbation amplitudes is investigated.",0905.3618v2
2009-06-03,Spectrum Sensing in Low SNR Regime via Stochastic Resonance,"Spectrum sensing is essential in cognitive radio to enable dynamic spectrum
access. In many scenarios, primary user signal must be detected reliably in low
signal-to-noise ratio (SNR) regime under required sensing time. We propose to
use stochastic resonance, a nonlinear filter having certain resonance
frequency, to detect primary users when the SNR is very low. Both block and
sequential detection schemes are studied. Simulation results show that, under
the required false alarm rate, both detection probability and average detection
delay can be substantially improved. A few implementation issues are also
discussed.",0906.0739v1
2009-06-18,Fast electromagnetic response of a thin film of resonant atoms with permanent dipole,"We consider the propagation of extremely short pulses through a dielectric
thin film containing resonant atoms (two level atoms) with permanent dipole.
Assuming that the film width is less than the field wave length, we can solve
the wave equation and reduce the problem to a system of generalized Bloch
equations describing the resonant atoms. We compute the stationary solutions
for a constant irradiation of the film. Superimposing a small amplitude linear
wave we compute the reflection and transmission coefficients. From these, one
can then deduce the different parameters of the model. We believe this
technique could be used in experiments to obtain the medium atomic and
relaxation parameters.",0906.3473v1
2009-06-19,Baryon Resonance Analysis from SAID,"We discuss the analysis of data from piN elastic scattering and single pion
photo- and electroproduction. The main focus is a study of low-lying
non-strange baryon resonances. Here we concentrate on some difficulties
associated with resonance identification, in particular the Roper and higher
P11 states.",0906.3709v2
2009-06-21,Resonant response of forced complex networks: the role of topological disorder,"We investigate the effect of topological disorder on a system of forced
threshold elements, where each element is arranged on top of complex
heterogeneous networks. Numerical results indicate that the response of the
system to a weak signal can be amplified at an intermediate level of
topological disorder, thus indicating the occurrence of
topological-disorder-induced resonance. Using mean field method, we obtain an
analytical understanding of the resonant phenomenon by deriving the effective
potential of the system. Our findings might provide further insight into the
role of network topology in signal amplification in biological networks.",0906.3848v1
2009-06-22,Kondo resonance narrowing in d- and f-electron systems,"By developing a simple scaling theory for the effect of Hund's interactions
on the Kondo effect, we show how an exponential narrowing of the Kondo
resonance develops in magnetic ions with large Hund's interaction. Our theory
predicts an exponential reduction of the Kondo temperature with spin S of the
Hund's coupled moment, a little-known effect first observed in d-electron
alloys in the 1960's, and more recently encountered in numerical calculations
on multi-band Hubbard models with Hund's interactions. We discuss the
consequences of Kondo resonance narrowing for the Mott transition in d-band
materials, particularly iron pnictides, and the narrow ESR linewidth recently
observed in ferromagnetically correlated f-electron materials.",0906.4107v1
2009-06-25,Observation of universality in ultracold 7Li three-body recombination,"We report on experimental evidence of universality in ultracold 7Li atoms'
three-body recombination loss in the vicinity of a Feshbach resonance. We
observe a recombination minimum and an Efimov resonance in regions of positive
and negative scattering lengths, respectively, which are connected through the
pole of the Feshbach resonance. Both observed features lie deeply within the
range of validity of the universal theory and we find that the relations
between their properties, i.e. widths and locations, are in an excellent
agreement with the theoretical predictions.",0906.4731v2
2009-06-26,Regular-to-Chaotic Tunneling Rates: From the Quantum to the Semiclassical Regime,"We derive a prediction of dynamical tunneling rates from regular to chaotic
phase-space regions combining the direct regular-to-chaotic tunneling mechanism
in the quantum regime with an improved resonance-assisted tunneling theory in
the semiclassical regime. We give a qualitative recipe for identifying the
relevance of nonlinear resonances in a given $\hbar$-regime. For systems with
one or multiple dominant resonances we find excellent agreement to numerics.",0906.4893v3
2009-06-26,Resonant magneto-conductance through a vibrating nanotube,"We address the electronic resonant transport in presence of a transverse
magnetic field through the single level of a suspended carbon nanotube acting
as a quantum oscillator. We predict a negative magneto-conductance with a
magnetic-field induced narrowing of the resonance line and a reduction of the
conductance peak when the nanotube is asymmetrically contacted to the leads. At
finite bias voltage we study the threshold for phonon-assisted transport.",0906.4948v1
2009-06-27,Neutrino-antineutrino oscillations as a possible solution for the LSND and MiniBooNE anomalies?,"We investigate resonance structures in CPT and Lorentz symmetry violating
neutrino-antineutrino oscillations in a two generation framework. We work with
four non-zero CPT-violating parameters that allow for resonant enhancements in
neutrino-antineutrino oscillation phenomena in vacuo which are suitably
described in terms of charge conjugation eigenstates of the system. We study
the relation between the flavor, charge conjugation and mass eigenbasis of
neutrino-antineutrino oscillations and examine the interplay between the
available CPT-violating parameter space and possible resonance structures.
Eventually we remark on the consequences of such scenarios for neutrino
oscillation experiments, namely possible solutions for the LSND and MiniBooNE
anomalies.",0906.5072v1
2009-06-30,Nonequilibrium electron transport in strongly correlated molecular junctions,"We investigate models of molecular junctions which constitute minimal
Hamiltonians to account for zero-bias-anomaly and the satellite features of
inelastic transport by molecular phonons. Through nonlinear transport
calculations with the imaginary-time nonequilibrium formalism, a HOMO-LUMO
model with Anderson-Holstein interaction is shown to produce co-tunneling
conductance peak in the vicinity of Kondo resonance which is mediated by a
re-emergent many-body resonance assisted by phonon excitations at bias equal to
the phonon frequency. Destruction of the resonance leads to
negative-differential-resistance in the sequential tunneling regime.",0906.5577v1
2009-07-06,Time-Energy Uncertainty in Neutrino Resonance: Quest for the Limit of Validity of Quantum Mechanics,"The role of quantum mechanical time-energy uncertainty (TEU) is central in
resonant neutrino (nue) reactions (3H to 3He to 3H) because of the unusual 18 y
lifetime of 3H. The TEU explicitly manifests itself by a non-intuitive but
quantitatively predictable spontaneous temporal growth of the nue resonance
signal. A slower growth rate signifies violation of TEU via a larger than
natural width of 3H, possibly imposed by a fundamental length in nature. Strong
limits on TEU violation can be set in the unprobed virgin energy regime of
~10-24 eV.",0907.0878v1
2009-07-05,Critical points and resonance of hyperplane arrangements,"If F is a master function corresponding to a hyperplane arrangement A and a
collection of weights y, we investigate the relationship between the critical
set of F, the variety defined by the vanishing of the one-form w = d log F, and
the resonance of y. For arrangements satisfying certain conditions, we show
that if y is resonant in dimension p, then the critical set of F has
codimension at most p. These include all free arrangements and all rank 3
arrangements.",0907.0896v2
2009-07-09,A Tuneable Few Electron Triple Quantum Dot,"In this paper we report on a tuneable few electron lateral triple quantum dot
design. The quantum dot potentials are arranged in series. The device is aimed
at studies of triple quantum dot properties where knowing the exact number of
electrons is important as well as quantum information applications involving
electron spin qubits. We demonstrate tuning strategies for achieving required
resonant conditions such as quadruple points where all three quantum dots are
on resonance. We find that in such a device resonant conditions at specific
configurations are accompanied by novel charge transfer behaviour.",0907.1322v1
2009-07-10,Measurement of Conduction Electron Polarization Via the Pairing Resonance,"We show that the pairing resonance in the Pauli-limited normal state of
ultra-thin superconducting Al films provides a spin-resolved probe of
conduction electron polarization in thin magnetic films. A
superconductor-insulator-ferromagnet tunneling junction is used to measure the
density of states in supercritical parallel magnetic fields that are well
beyond the Clogston-Chandresekhar limit, thus greatly extending the field range
of the tunneling density of states technique. The applicability and limitations
of using the pairing resonance as a spin probe are discussed.",0907.1800v1
2009-07-12,Electrically detected magnetic resonance using radio-frequency reflectometry,"The authors demonstrate readout of electrically detected magnetic resonance
at radio frequencies by means of an LCR tank circuit. Applied to a silicon
field-effect transistor at milli-kelvin temperatures, this method shows a
25-fold increased signal-to-noise ratio of the conduction band electron spin
resonance and a higher operational bandwidth of > 300 kHz compared to the kHz
bandwidth of conventional readout techniques. This increase in temporal
resolution provides a method for future direct observations of spin dynamics in
the electrical device characteristics.",0907.2022v1
2009-07-13,Choosing Dielectric or Magnetic Material to Optimize the Bandwidth of Miniaturized Resonant Antennas,"We address the question of the optimal choice of loading material for antenna
miniaturization. A new approach to identify the optimal loading material,
dielectric or magnetic, is presented for resonant antennas. Instead of
equivalent resonance circuits or transmission-line models, we use the analysis
of radiation to identify the fields contributing mostly to the stored energy.
This helps to determine the beneficial material type. The formulated principle
is qualitatively illustrated using three antenna types. Guidelines for
different antenna types are presented.",0907.2132v1
2009-07-14,Localized ferromagnetic resonance force microscopy in permalloy-cobalt films,"We report Ferromagnetic Resonance Force Microscopy (FMRFM) experiments on a
justaposed continuous films of permalloy and cobalt. Our studies demonstrate
the capability of FMRFM to perform local spectroscopy of different
ferromagnetic materials. Theoretical analysis of the uniform resonance mode
near the edge of the film agrees quantitatively with experimental data. Our
experiments demonstrate the micron scale lateral resolution in determining
local magnetic properties in continuous ferromagnetic samples.",0907.2415v1
2009-07-29,Pinning mode resonance of a Skyrme crystal near Landau level filling factor $ν$=1,"Microwave pinning-mode resonances found around integer quantum Hall effects,
are a signature of crystallized quasiparticles or holes. Application of
in-plane magnetic field to these crystals, increasing the Zeeman energy, has
negligible effect on the resonances just below Landau level filling $\nu=2$,
but increases the pinning frequencies near $\nu=1$, particularly for smaller
quasiparticle/hole densities. The charge dynamics near $\nu=1$, characteristic
of a crystal order, are affected by spin, in a manner consistent with a Skyrme
crystal.",0907.5218v1
2009-08-14,Dramatic reductions in inelastic cross sections for ultracold collisions near Feshbach resonances,"We show that low-energy inelastic cross sections can decrease as well as
increase in the vicinity of a zero-energy Feshbach resonance. When an external
field is used to tune across such a resonance, the real and imaginary parts of
the scattering length show asymmetric oscillations, with both peaks and
troughs. In favorable circumstances the inelastic collision rate can be reduced
almost to zero. This may be important for efforts to achieve evaporative and
sympathetic cooling for molecules.",0908.2065v1
2009-08-15,The two-atom energy spectrum in a harmonic trap near a Feshbach resonance at higher partial waves,"Two atoms in an optical lattice may be made to interact strongly at higher
partial waves near a Feshbach resonance. These atoms, under appropriate
constraints, could be bosonic or fermionic. The universal $l=2$ energy spectrum
for such a system, with a caveat, is presented in this paper, and checked with
the spectrum obtained by direct numerical integration of the Schr\""odinger
equation. The results reported here extend those of Yip for p-wave resonance
(Phys. Rev. A {\bf 78}, 013612 (2008)), while exploring the limitations of a
universal expression for the spectrum for the higher partial waves.",0908.2204v1
2009-08-18,Suppression of power-broadening in strong-coupling photoassociation in the presence of a Feshbach resonance,"Photoassociation (PA) spectrum in the presence of a magnetic Feshbach
resonance is analyzed. Nonperturbative solution of the problem yields
analytical expressions for PA linewidth and shift which are applicable for
arbitrary PA laser intensity and magnetic field tuning of Feshbach Resonance.
We show that by tuning magnetic field close to Fano minimum, it is possible to
suppress power broadening at increased laser intensities. This occurs due to
quantum interference of PA transitions from unperturbed and perturbed
continuum. Line narrowing at high laser intensities is accompanied by large
spectral shifts. We briefly discuss important consequences of line narrowing in
cold collisions.",0908.2549v1
2009-08-20,Why Neutrino Lines are Hypersharp,"It was recently pointed out that mono-energetic neutrino lines from the
2-body decay of tritium (tau ~ 18-y) can be emitted, a significant fraction,
with natural line width (~10-24 eV) for hypersharp resonance transitions 3H-->
<--3He. The very long lifetime typical of a neutrino transition, encountered
for the first time in resonance, is the key to this surprising effect which is
not intuitive from perspectives of line broadening in resonances of short lived
(tau ~ microsec) states.",0908.2980v2
2009-08-26,Compression of an intensive light pulse in a dense resonant medium and photonic-band-gap structures containing it,"Intensive light pulse interaction with a dense resonant medium is considered.
The possibilities of optical switching and pulse compression at realistic
parameters of the medium are analyzed. Pulse shape transformation in different
photonic band gap structures containing a dense resonant medium is studied. In
particular the effect of dispersion compensation due to nonlinear interaction
with a medium is reported. The possibility of pulse control with another pulse
is considered in the schemes of co- and counter-propagating pulses. It is shown
that a photonic crystal makes controlling more effective, at least in the case
of co-propagating pulses.",0908.3777v1
2009-08-26,Charge transport in graphene with resonant scatterers,"The full counting statistics for the charge transport through an undoped
graphene sheet in the presence of strong potential impurities is studied.
Treating the scattering off the impurity in the s-wave approximation, we
calculate the impurity correction to the cumulant generating function. This
correction is universal provided the impurity strength is tuned to a resonant
value. In particular, the conductance of the sample acquires a correction of
16e^2/(pi^2 h) per resonant impurity.",0908.3793v2
2009-08-27,Axial charges of the nucleon and N* resonances,"The axial charges of the nucleon and the well-established N* resonances are
studied within a consistent framework. For the first time the axial charges of
the N* resonances are produced for the relativistic constituent quark model.
The axial charge of the nucleon is predicted close to experiment, and the ones
of N*(1535) and N*(1650), the only cases where such a comparison is possible,
agree well with results from quantum chromodynamics on the lattice that have
recently become available. The relevance of the magnitudes of the N* axial
charges for the low-energy behavior of quantum chromodynamics is discussed.",0908.3959v1
2009-08-30,Extraction of an Entanglement by Repetition of the Resonant Transmission of an Ancilla Qubit,"A scheme for the extraction of entanglement in two noninteracting qubits
(spins) is proposed. The idea is to make use of resonant transmission of
ancilla qubit through the two fixed qubits, controlled by the entanglement in
the scatterers. Repetition of the resonant transmission extracts the singlet
state in the target qubits from their arbitrary given state. Neither the
preparation nor the post-selection of the ancilla spin is required, in contrast
to the previously proposed schemes.",0908.4377v2
2009-09-02,Ferroelectrical spin wave resonance,"New phenomenon is experimentally identified: ferroelectrical spin wave
resonance (FE SWR), which consist in characteristic splitting of vibration
(electronic-vibration) levels in optical spectra of interacting localized
centers. Spectral positions of ESWR lines are determined in linear approach by
quadratic dispersion law. It has been found that the values of resonance mode
amplitudes are inversely proportional to mode numbers (by low excitation
level). The prediction that Raman-ESWR and IR-ESWR are characterized by
splitting constants with different values has been confirmed. Their ratio is
approximately equal two (by the frequencies of zero modes reduced to the same
value). It is independent argument for FE SWR identification.",0909.0467v1
2009-09-07,Fine structure in the tunneling spectra of electron-doped cuprates: No coupling to magnetic resonance mode,"We analyze high-resolution scanning tunneling spectra of the electron-doped
cuprate Pr0.88LaCe0.12CuO4 (T_c = 24 K). We find that the spectral fine
structure below 35 meV is consistent with strong coupling to a bosonic mode at
16 meV, in quantitative agreement with early tunneling spectra of
Nd1.85Ce0.15CuO4. Since the energy of the bosonic mode is significantly higher
than that (9.5-11 meV) of the magnetic resonance-like mode observed by
inelastic neutron scattering, the coupling feature at 16 meV cannot arise from
strong coupling to the magnetic mode. The present work thus demonstrates that
the magnetic resonance-like mode cannot be the origin of high-temperature
superconductivity in electron-doped cuprates.",0909.1136v1
2009-09-07,The theory of photorefractive resonance for localized beams in two-carrier photorefractive systems,"This paper extends the existing theory of two carrier photorefractivity
resonance, which is generally applied to Iron doped Indium Phosphide (InP:Fe),
to the case of low non-harmonic illumination. The space charge field profile is
computed, and the variations of its amplitude, width and position are
determined as functions of the background intensity. The effect of
photorefractive resonance on these quantities is evidenced, contributing to the
understanding of published experimental results in InP:Fe.",0909.1217v1
2009-09-07,Disentangling the dynamical origin of P11 Nucleon Resonances,"We show that two almost degenerate poles near the $\pi\Delta$ threshold and
the next higher mass pole in the $P_{11}$ partial wave of $\pi N$ scattering
evolve from a single bare state through its coupling with $\pi N$, $\eta N$ and
$\pi\pi N$ reaction channels. This finding provides new information on
understanding the dynamical origins of the Roper $N^*(1440)$ and $N^*(1710)$
resonances listed by Particle Data Group. Our results for the resonance poles
in other $\pi N$ partial waves are also presented.",0909.1356v2
2009-09-10,Optical response of finite-length carbon nanotubes,"Optical response of finite-length metallic carbon nanotubes is calculated
including effects of induced edge charges in a self-consistent manner. The
results show that the main resonance corresponding to excitation of the
fundamental plasmon mode with wave vector $\pi/l$ with $l$ being the tube
length is quite robust and unaffected. This arises because the strong electric
field associated with edge charges is screened and decays rapidly inside the
nanotube. For higher-frequency resonances, the field starts to be mixed and
tends to shift resonances to higher frequencies.",0909.1908v1
2009-09-14,Multistability and localization in coupled nonlinear split-ring resonators,"We study the dynamics of a pair of nonlinear split-ring resonators (a
`metadimer') excited by an alternating magnetic field and coupled magnetically.
Linear metadimers of this kind have been recently used as the elementary
components for three-dimensional metamaterials or 'stereometamaterials' [N. Liu
{\em et al}, Nature Photon. {\bf 3}, 157 (2009)]. We demonstrate that
nonlinearity offers more possibilities with respect to real-time tunability and
a multiplicity of states which can be reached by varying the external field.
Moreover, we demonstrate almost total localization of the energy in one of the
resonators in a broad range of parameters.",0909.2503v1
2009-10-06,Resonant Tunneling in Scalar Quantum Field Theory,"The resonant tunneling phenomenon is well understood in quantum mechanics. We
argue why a similar phenomenon must be present in quantum field theory. We then
use the functional Schr\""odinger method to show how resonant tunneling through
multiple barriers takes place in quantum field theory with a single scalar
field. We also show how this phenomenon in scalar quantum field theory can lead
to an exponential enhancement of the single-barrier tunneling rate. Our
analysis is carried out in the thin-wall approximation.",0910.1088v1
2009-10-09,Entanglement and parametric resonance in driven quantum systems,"We study the relationship between entanglement and parametric resonance in a
system of two coupled time-dependent oscillators. As a measure of bipartite
entanglement, we calculate the linear entropy for the reduced density operator,
from which we study the entanglement dynamics. In particular, we find that the
bipartite entanglement increases in time up to a maximal mixing scenario, when
the set of auxiliary dynamical parameters are under parametric resonance.
Moreover, we obtain a closed relationship between the correlations in the
ground state, the localisation of the Wigner function in phase space, and the
localisation of the wave function of the total system.",0910.1600v1
2009-10-13,Resonant coupling of coplanar waveguides with ferromagnetic tubes,"Resonant coupling of coplanar waveguides is explored by wrapping proximate
shorted ends of the waveguides with micron size ferromagnetic Co90Ta5Zr5 tubes.
Ferromagnetic resonance and up to 7 outer surface modes are identified.
Experimental results for these contorted rectangular tubes are in good
agreement with micromagnetic simulations and model calculations of
magnetostatic modes for an elliptical ferromagnetic tube. These results
indicate that the modes are largely determined by tube topology and dimensions
but less so by the detailed shape.",0910.2442v1
2009-10-15,Design of plasmonic photonic crystal resonant cavities for polarization sensitive infrared photodetectors,"We design a polarization-sensitive resonator for use in midinfrared
photodetectors, utilizing a photonic crystal cavity and a single or
double-metal plasmonic waveguide to achieve enhanced detector efficiency due to
superior optical confinement within the active region. As the cavity is highly
frequency and polarization-sensitive, this resonator structure could be used in
chip-based infrared spectrometers and cameras that can distinguish among
different materials and temperatures to a high degree of precision.",0910.2801v1
2009-10-19,Multiphoton Femtosecond Control of Resonance-Mediated Generation of Short-Wavelength Coherent Broadband Radiation,"We introduce a new scheme for generating short-wavelength coherent broadband
radiation with well-controlled spectral characteristics. It is based on shaping
long-wavelength femtosecond pulse to coherently control atomic
resonance-mediated (2+1) three-photon excitation to a broad far-from-resonance
continuum. Here, the spectrum (central frequency and bandwidth) of
deep-ultraviolet coherent broadband radiation generated in Na vapor is
experimentally controlled by tuning the linear chirp we apply to the driving
phase-shaped near-infrared femtosecond pulse. This is a first step in
implementing the full scheme for producing shaped femtosecond pulses at
wavelengths down-to the vacuum-ultraviolet range.",0910.3526v1
2009-10-20,SQUID Detection of Quantized Mechanical Motion,"We predict that quantized mechanical motion can be detected by embedding a
mechanical resonator into a quantum SQUID. If the system is tuned to the regime
when a plasma frequency of the SQUID matches the resonator frequency, the
doubly-degenerate quantum level of the system is split by the coupling between
the SQUID and the resonator. Observation of an avoided crossing as the function
of external flux would be an unambiguous evidence of quantum nature of
mechanical motion. We also investigate the conditions maximizing the level
splitting.",0910.3900v1
2009-10-22,Magnetic dipole moments in single and coupled split-ring resonators,"We examine the role of magnetic dipoles in single and coupled pairs of
metallic split-ring resonators by numerically computing their magnitude and
examining their relative contributions to the scattering cross section. We
demonstrate that magnetic dipoles can strongly influence the scattering cross
section along particular directions. It is also found that the magnetic dipole
parallel to the incident magnetic field and/or high-order multipoles may play a
significant role in the linear response of coupled split-ring resonators.",0910.4210v1
2009-10-22,Surface plasmon resonances of metallic nanostars/nanoflowers for surface-enhanced Raman scattering,"We investigate theoretically the optical properties associated to plasmon
resonances of metal nanowires with cross section given by low-order Chebyshev
nanoparticles (like rounded-tip nanostars or nanoflowers). The impact of the
nanoflower shape is analyzed for varying symmetry and deformation parameter
through the spectral dependence of resonances, and their corresponding near
field distributions. Large field intensity enhancements are obtained at the
gaps between petals, apart from the tips themselves, which make these
nanostars/nanoflowers specially suitable to host molecules for SERS sensing
applications.",0910.4269v1
2009-10-23,Resonance Lifetimes from Complex Densities,"The ab-initio calculation of resonance lifetimes of metastable anions
challenges modern quantum-chemical methods. The exact lifetime of the
lowest-energy resonance is encoded into a complex ""density"" that can be
obtained via complex-coordinate scaling. We illustrate this with one-electron
examples and show how the lifetime can be extracted from the complex density in
much the same way as the ground-state energy of bound systems is extracted from
its ground-state density.",0910.4599v1
2009-10-25,The Cauchy Problem of the Schrödinger-Korteweg-de Vries System,"We study the Cauchy problem of the Schr\""odinger-Korteweg-de Vries system.
First, we establish the local well-posedness results, which improve the results
of Corcho, Linares (2007). Moreover, we obtain some ill-posedness results,
which show that they are sharp in some well-posedness thresholds. Particularly,
we obtain the local well-posedness for the initial data in
$H^{-{3/16}+}(\R)\times H^{-{3/4}+}(\R)$ in the resonant case, it is almost the
optimal except the endpoint. At last we establish the global well-posedness
results in $H^s(\R)\times H^s(\R)$ when $s>\dfrac{1}{2}$ no matter in the
resonant case or in the non-resonant case, which improve the results of Pecher
(2005).",0910.4653v1
2009-11-09,Imbalanced Feshbach-resonant Fermi gases,"We present an overview of recent developments in species-imbalanced
(""polarized"") Feshbach-resonant Fermi gases. We summarize the current status of
thermodynamics of these systems in terms of a phase diagram as a function of
the Feshbach resonance detuning, polarization and temperature. We review
instabilities of the s-wave superfluidity across the BEC-BCS crossover to phase
separation, FFLO states, polarized molecular superfluidity and the normal
state, driven by the species imbalance. We discuss different models and
approximations of this system and compare their predictions to current
experiments.",0911.1740v2
2009-11-13,Nano-Torsional Resonator Torque Magnetometry,"Magnetic torque is used to actuate nano-torsional resonators, which are
fabricated by focused-ion-beam milling of permalloy coated silicon nitride
membranes. Optical interferometry is used to measure the mechanical response of
two torsion modes at resonance, which is proportional to the magnetization
vector of the nanomagnetic volume. By varying the bias magnetic field, the
magnetic behavior can be measured with excellent sensitivity ($\approx 10^8
\mu_B$) for single magnetic elements.",0911.2517v2
2009-11-20,Magnetic Resonance Imaging with a Dielectric Lens,"Recently, metamaterials have been introduced to improve the signal-to-noise
ratio (SNR) of magnetic resonance images with very promising results. However,
the use polymers in the generation of high quality images in magnetic resonance
imaging has not been fully been investigated. These investigations explored the
use of a dielectric periodical array as a lens to improve the image SNR
generated with single surface coils. Commercial polycarbonate glazing sheets
were used together with a circular coil to generate phantom images at 3 Tesla
on a clinical MR imager.",0911.4116v1
2010-01-08,Bifurcation of Periodic Delay Differential Equations at Points of 1:4 Resonance,"The time-periodic scalar delay differential equation $\dot x(t)=\gamma
f(t,x(t-1))$ is considered, which leads to a resonant bifurcation of the
equilibrium at critical values of the parameter. Using Floquet theory, spectral
projection and center manifold reduction, we give conditions for the stability
properties of the bifurcating invariant curves and four-periodic orbits. The
coefficients of the third order normal form are derived explicitly. We show
that the 1:4 resonance has no effect on equations of the form $\dot
z(t)=-\gamma r(t)g(x(t-1))$.",1001.1193v1
2010-01-09,Group velocity control in a four level system through interacting dark resonances,"We investigate dispersion and absorption properties of a weak probe field in
a four level atomic system through interacting dark resonances. We show that
two narrow peaks appears in the optical spectra due to the presence of
interacting dark resonances. This two narrow peaks leads to the superluminal
light propagation with strong absorption. However, if a weak incoherent pump
field is exerted to the probe transition, then the peaks structures can be
changed such that two absorption peaks transformed to two gain deeps. We Show
that both subluminal and superluminal light propagation occur in this system,
where controlled by the incoherent pumping strength.",1001.1422v1
2010-01-11,Resonances in an external field: the 1+1 dimensional case,"Using non-relativistic effective field theory in 1+1 dimensions, we
generalize Luescher's approach for resonances in the presence of an external
field. This generalized approach provides a framework to study the
infinite-volume limit of the form factor of a resonance determined in lattice
simulations.",1001.1641v1
2010-01-21,Concave Plasmonic Particles: Broad-Band Geometrical Tunability in the Near Infra-Red,"Optical resonances spanning the Near and Short Infra-Red spectral regime were
exhibited experimentally by arrays of plasmonic nano-particles with concave
cross-section. The concavity of the particle was shown to be the key ingredient
for enabling the broad band tunability of the resonance frequency, even for
particles with dimensional aspect ratios of order unity. The atypical
flexibility of setting the resonance wavelength is shown to stem from a unique
interplay of local geometry with surface charge distributions.",1001.3785v1
2010-01-27,Quantization of classical integrable systems. Part IV: systems of resonant oscillators,"By applying methods already discussed in a previous series of papers by the
same authors, we construct here classes of integrable quantum systems which
correspond to n fully resonant oscillators with nonlinear couplings. The same
methods are also applied to a series of nontrivial integral sets of functions,
which can be constructed when additional symmetries are present due to the
equality of some of the frequencies. Besides, for n=3 and resonance 1:1:2, an
exceptional integrable system is obtained, in which integrability is not
explicitly connected with this type of symmetry. In this exceptional case,
quantum integrability can be realized by means of a modification of the
symmetrization procedure.",1001.4909v1
2010-02-10,Off-resonance field enhancement by spherical nanoshells,"We study light scattering by spherical nanoshells consistent of
metal/dielectric composites. We consider two geometries of metallic nanoshell
with dielectric core, and dielectric coated metallic nanoparticle. We
demonstrate that for both geometries the local field enhancement takes place
out of resonance regions (""dark states""), which, nevertheless, can be
understood in terms of the Fano resonance. At optimal conditions the light is
stronger enhanced inside the dielectric material. By using nonlinear dielectric
materials it will lead to a variety nonlinear phenomena applicable for
photonics applications.",1002.2057v1
2010-02-19,Aplication of Frequency Map Analysis to Beam-Beam Effects Study in Crab Waist Collision Scheme,"We applied Frequency Map Analysis (FMA) - a method that is widely used to
explore dynamics of Hamiltonian systems - to beam-beam effects study. The
method turned out to be rather informative and illustrative in the case of a
novel Crab Waist collision approach, when ""crab"" focusing of colliding beams
results in significant suppression of betatron coupling resonances. Application
of FMA provides visible information about all working resonances, their widths
and locations in the planes of betatron tunes and betatron amplitudes, so the
process of resonances suppression due to the beams crabbing is clearly seen.",1002.3733v2
2010-02-26,Controlled generation of field squeezing with cold atomic clouds coupled to a superconducting transmission line resonator,"We propose an efficient method for controlled generation of field squeezing
with cold atomic clouds trapped close to a superconducting transmission line
resonator. It is shown that, based on the coherent strong magnetic coupling
between the collective atomic spins and microwave fields in the transmission
line resonator, two-mode or single mode field squeezed states can be generated
through coherent control on the dynamics of the system. The degree of squeezing
and preparing time can be directly controlled through tuning the external
classical fields. This protocol may offer a promising platform for implementing
scalable on-chip quantum information processing with continuous variables.",1002.4953v1
2010-03-01,Non-Weyl Resonance Asymptotics for Quantum Graphs,"We consider the resonances of a quantum graph $\mathcal G$ that consists of a
compact part with one or more infinite leads attached to it. We discuss the
leading term of the asymptotics of the number of resonances of $\mathcal G$ in
a disc of a large radius. We call $\mathcal G$ a \emph{Weyl graph} if the
coefficient in front of this leading term coincides with the volume of the
compact part of $\mathcal G$. We give an explicit topological criterion for a
graph to be Weyl. In the final section we analyze a particular example in some
detail to explain how the transition from the Weyl to the non-Weyl case occurs.",1003.0051v1
2010-03-01,Collapse and revival in inter-band oscillations of a two-band Bose-Hubbard model,"We study the effect of a many-body interaction on inter-band oscillations in
a two-band Bose-Hubbard model with external Stark force. Weak and strong
inter-band oscillations are observed, where the latter arise from a resonant
coupling of the bands. These oscillations collapse and revive due to a weak
two-body interaction between the atoms. Effective models for oscillations in
and out of resonance are introduced that provide predictions for the system's
behaviour, particularly for the time-scales for the collapse and revival of the
resonant inter-band oscillations.",1003.0353v1
2010-03-10,Inelastic neutron scattering: resonances and fluctuations,"R-function theory of Thomas used in study of inelastic scattering of neutrons
to a definite state. Onset of fluctuations, effects of randomness of phases of
interfering amplitudes, and variations in statistical distributions of neutron
widths considered in detail. Fluctuations exhibit well-defined maxima and sharp
minima. For certain adjacent resonances, strong interference effects are
predicted.",1003.2002v2
2010-03-11,Linewidth broadening of a quantum dot coupled to an off-resonant cavity,"We study the coupling between a photonic crystal cavity and an off-resonant
quantum dot under resonant excitation of the cavity or the quantum dot.
Linewidths of the quantum dot and the cavity as a function of the excitation
laser power are measured. We show that the linewidth of the quantum dot,
measured by observing the cavity emission, is significantly broadened compared
to the theoretical estimate. This indicates additional incoherent coupling
between the quantum dot and the cavity.",1003.2350v1
2010-03-23,Electron Paramagnetic Resonance of Boron Acceptors in Isotopically Purified Silicon,"The electron paramagnetic resonance (EPR) linewidths of B acceptors in Si are
found to reduce dramatically in isotopically purified 28Si single crystals.
Moreover, extremely narrow substructures in the EPR spectra are visible
corresponding to either an enhancement or a reduction of the absorbed microwave
on resonance. The origin of the substructures is attributed to a combination of
simultaneous double excitation and spin relaxation in the four level spin
system of the acceptors. A spin population model is developed which
qualitatively describes the experimental results.",1003.4339v1
2010-03-26,Superconductor terahertz metamaterial,"We characterize the behaviour of split ring resonators made up of
high-transition temperature YBCO superconductor using terahertz time domain
spectroscopy. The superconductor metamaterial shows sharp change in the
transmission spectrum at the fundamental inductive-capacitive resonance and the
dipole resonance as the temperature dips below the transition temperature. Our
results reveal that the high performance of such a metamaterial is limited by
material imperfections and defects such as cracks, voids and secondary phases
which play dominant role in partially impeding the flow of current causing
dissipation of energy and electrical resistance to appear in the superconductor
film.",1003.5169v1
2010-04-01,Resonance webs of hyperplane arrangements,"Each irreducible component of the first resonance variety of a hyperplane
arrangement naturally determines a codimension one foliation on the ambient
space. The superposition of these foliations define what we call the resonance
web of the arrangement. In this paper we initiate the study of these objects
with emphasis on their spaces of abelian relations.",1004.0122v2
2010-04-16,Resonance wave functions located at the Stark saddle point,"We calculate quantum mechanically exact wave functions of resonances in
spectra of the hydrogen atom in crossed external fields and prove the existence
of long-lived decaying quantum states localized at the Stark saddle point. A
spectrum of ground and excited states reproducing the nodal patterns expected
from simple quadratic and cubic expansions of the potential in the vicinity of
the saddle point can be identified. The results demonstrate the presence of
resonances in the vicinity of the saddle predicted by simple approximations.",1004.2876v2
2010-04-19,Fast readout of a single Cooper-pair box using its quantum capacitance,"We have fabricated a single Cooper-pair box (SCB) together with an on-chip
lumped element resonator. By utilizing the quantum capacitance of the SCB, its
state can be read out by detecting the phase of a radio-frequency (rf) signal
reflected off the resonator. The resonator was optimized for fast readout. By
studying quasiparticle tunneling events in the SCB, we have characterized the
performance of the readout and found that we can perform a single shot parity
measurement in approximately 50 ns. This is an order of magnitude faster than
previously reported measurements.",1004.3279v1
2010-04-27,Shot noise in the self-dual Interacting Resonant Level Model,"By using two independent and complementary approaches, we compute exactly the
shot noise in an out-of-equilibrium interacting impurity model, the Interacting
Resonant Level model at its self-dual point. An analytical approach based on
the Thermodynamical Bethe Ansatz allows to obtain the density matrix in the
presence of a bias voltage, which in turn allows for the computation of any
observable. A time-dependent Density Matrix Renormalization Group technique,
that has proven to yield the correct result for a free model (the Resonant
Level Model) is shown to be in perfect agreement with the former method.",1004.4811v1
2010-04-29,Coulomb-enhanced resonance transmission of quantum SINIS junctions,"Coherent charge transfer through a ballistic gated SINIS junction is mediated
by the resonant tunneling via the Andreev states. Extra charge accommodated on
the Andreev levels partially compensates the charge induced by the gate voltage
preserving the electron wavelength and maintaining the resonance conditions in
a broad range of gate voltages. As a result, the transparency of the junction
as well as the supercurrent trough it can be substantially increased as
compared to the zero-Coulomb case.",1004.5288v1
2010-06-05,Molecular structure of highly-excited resonant states in $^{24}$Mg and the corresponding $^8$Be+$^{16}$O and $^{12}$C+$^{12}$C decays,"Exotic $^8$Be and $^{12}$C decays from high-lying resonances in $^{24}$Mg are
analyzed in terms of a cluster model. The calculated quantities agree well with
the corresponding experimental data. It is found that the calculated decay
widths are very sensitive to the angular momentum carried by the outgoing
cluster. It is shown that this property makes cluster decay a powerful tool to
determine the spin as well as the molecular structures of the resonances.",1006.1071v1
2010-06-11,Observation of pinning mode in Wigner solid of 1/3 fractional quantum Hall excitations,"We report the observation of a resonance in the microwave spectra of the real
diagonal conductivities of a two-dimensional electron system within a range of
~ +- .0.015 $ from filling factor $\nu=1/3$. The resonance is remarkably
similar to resonances previously observed near integer $\nu$, and is
interpreted as the collective pinning mode of a disorder-pinned Wigner solid
phase of $e/3$-charged carriers .",1006.2335v2
2010-06-16,Diffusion and criticality in undoped graphene with resonant scatterers,"A general theory is developed to describe graphene with arbitrary number of
isolated impurities. The theory provides a basis for an efficient numerical
analysis of the charge transport and is applied to calculate the minimal
conductivity of graphene with resonant scatterers. In the case of smooth
resonant impurities conductivity grows logarithmically with increasing impurity
concentration, in agreement with renormalization group analysis for the
symmetry class DIII. For vacancies (or strong on-site potential impurities) the
conductivity saturates at a constant value that depends on the vacancy
distribution among two sublattices as expected for the symmetry class BDI.",1006.3299v1
2010-06-23,Resonant diffusion on solid surfaces,"A new approach to Brownian motion of atomic clusters on solid surfaces is
developed. The main topic discussed is the dependence of the diffusion
coefficient on the fit between the surface static potential and the internal
cluster configuration. It is shown this dependence is non-monotonous, which is
the essence of the so-called resonant diffusion. Assuming quicker inner motion
of the cluster than its translation, adiabatic separation of these variables is
possible and a relatively simple expression for the diffusion coefficient is
obtained. In this way, the role of cluster vibrations is accounted for, thus
leading to a more complex resonance in the cluster surface mobility.",1006.4440v2
2010-06-22,Spatially coherent surface resonance states derived from magnetic resonances,"A thin metamaterial slab comprising a dielectric spacer sandwiched between a
metallic grating and a ground plane is shown to possess spatially coherent
surface resonance states that span a large frequency range and can be tuned by
structural and material parameters. They give rise to nearly perfect
angle-selective absorption and thus exhibit directional thermal emissivity.
Direct numerical simulations show that the metamaterial slab supports spatially
coherent thermal emission in a wide frequency range that is robust against
structural disorder.",1006.4528v1
2010-07-04,Prediction of narrow $N^{*}$ and $Λ^*$ resonances with hidden charm above 4 GeV,"The interaction between various charmed mesons and charmed baryons are
studied within the framework of the coupled channel unitary approach with the
local hidden gauge formalism. Several meson-baryon dynamically generated narrow
$N^*$ and $\Lambda^*$ resonances with hidden charm are predicted with mass
above 4 GeV and width smaller than 100 MeV. The predicted new resonances
definitely cannot be accommodated by quark models with three constituent quarks
and can be looked for at the forthcoming PANDA/FAIR experiments.",1007.0573v1
2010-07-06,Extraction of the resonance parameters at finite times,"In this paper we propose a model-independent method to extract the resonance
parameters on the lattice directly from the Euclidean 2-point correlation
functions of the field operators at finite times. The method is tested in case
of the two-point function of the Delta-resonance, calculated at one loop in
Small Scale Expansion. Further, the method is applied to a 1+1-dimensional
model with two coupled Ising spins and the results are compared with earlier
ones obtained by using Luescher's approach.",1007.0860v1
2010-07-23,Model Independent Extraction of S-Matrix Poles from Experimental Data,"By separating data points close to a resonance into intervals, and fitting
all possible intervals to a simple pole with constant coherently added
background, we obtained a substantial number of convergent fits. After a
carefully chosen set of statistical constraints was imposed, we calculated the
average of a resonance pole position from the statistically acceptable results.
We used this method to find pole positions of Z and N(1440) resonances, and to
show that the strong discrepancy between the old and new measurements of the
Upsilon(11020) mass stems from specious comparison of the Upsilon(11020) pole
with its Breit-Wigner mass.",1007.4207v1
2010-07-28,Thin Film Absorbers Based on Plasmonic Phase Resonances,"We demonstrate an efficient double-layer light absorber by exciting plasmonic
phase resonances. We show that the addition of grooves can cause mode splitting
of the plasmonic waveguide cavity modes and all the new resonant modes exhibit
large absorptivity greater than 90%. Some of the generated absorption peaks
have wide-angle characteristics. Furthermore, we find that the proposed
structure is fairly insensitive to the alignment error between different
layers. The proposed plasmonic nano-structure designs may have exciting
potential applications in thin film solar cells, thermal emitters, novel
infrared detectors, and highly sensitive bio-sensors.",1007.5079v1
2010-08-02,Strong Coupling between On Chip Notched Ring Resonator and Nanoparticle,"We have demonstrated a new photonic structure to achieve strong optical
coupling between nanoparticle and photonic molecule by utilizing a notched
micro ring resonators. By creating a notch in the ring resonator and putting a
nanoparticle inside the notch, large spectral shifts and splittings at nm scale
can be achieved, compared to only pm scale observed by fiber tip evanescently
coupled to the surface of microsphere, thereby significantly lowered the
quality factor requirement for single nanoparticle detection. The ability for
sorting the type of nanoparticles due to very different mode shift and
splitting behavior of dielectric and metallic nanoparticles is also emphasized.",1008.0282v1
2010-08-05,Whispering gallery mode resonator based ultra-narrow linewidth external cavity semiconductor laser,"We demonstrate a miniature self-injection locked DFB laser using resonant
optical feedback from a high-Q crystalline whispering gallery mode resonator.
The linewidth reduction factor is greater than 10,000, with resultant
instantaneous linewidth less than 200 Hz. The minimal value of the Allan
deviation for the laser frequency stability is 3x10^(-12) at the integration
time of 20 us. The laser possesses excellent spectral purity and good long term
stability.",1008.0896v1
2010-08-05,Analysis of the manufacturing variation in a coupled micro resonators array based on its designed value and measured eigenfrequencies,"Manufacturing variation in the micro fabrication process inevitably alters
the size of the designed structure and thereafter influences the performance of
devices to some extent. A good knowledge of this effect will help the design
and optimization of the devices. In this letter, we propose an analytical model
to investigate the effect of manufacturing variation on the individual
resonator in a chain of coupled micro mechanical resonators. The model is also
used in a reverse manner to estimate the possible range of manufacturing
variation based on the designed value and the measured frequency response.",1008.0944v1
2010-08-05,Neutron stars with small radii -- the role of delta resonances,"Recent neutron star observations suggest that the masses and radii of neutron
stars may be smaller than previously considered, which would disfavor a purely
nucleonic equation of state. In our model, we use a the flavor SU(3) sigma
model that includes delta resonances and hyperons in the equation of state. We
find that if the coupling of the delta resonances to the vector mesons is
slightly smaller than that of the nucleons, we can reproduce both the measured
mass-radius relationship and the extrapolated equation of state.",1008.0957v1
2010-08-06,Feshbach resonances in 3He*-4He* mixtures,"We discuss the stability of homonuclear and heteronuclear mixtures of 3He and
4He atoms in the metastable 2^3S_1 state (He*) and predict positions and widths
of Feshbach resonances by using the Asymptotic Bound-state Model (ABM). All
calculations are performed without fit parameters, using \emph{ab-initio}
calculations of molecular potentials. One promising very broad Feshbach
resonance (\Delta B=72.9^{+18.3}_{-19.3} mT) is found that allows for tuning of
the inter-isotope scattering length.",1008.1141v1
2010-08-06,Observation of magneto-phonon resonance of Dirac fermions in graphite,"Coherent coupling of Dirac fermion magneto-excitons with an optical phonon is
observed in graphite as marked magnetic-field dependent splittings and
anti-crossing behavior of the two coupled modes. The sharp magneto-phonon
resonance occurs in regions of the graphite sample with properties of superior
single-layer graphene having enhanced lifetimes of Dirac fermions. The greatly
reduced carrier broadening to values below the graphene electron-phonon
coupling constant explains the appearance of sharp resonances that reveal a
fundamental interaction of Dirac fermions.",1008.1206v1
2010-08-09,Theoretical comparison of quantum Zeno gates and nonlinear phase gates,"Quantum logic operations can be implemented using nonlinear phase shifts (the
Kerr effect) or the quantum Zeno effect based on strong two-photon absorption.
Both approaches utilize three-level atoms, where the upper level is tuned on
resonance for the Zeno gates and off-resonance for the nonlinear phase gates.
The performance of nonlinear phase gates and Zeno gates are compared under
conditions where the parameters of the resonant cavities and three-level atoms
are the same in both cases. It is found that the expected performance is
comparable for the two approaches, despite the apparent differences in the way
they are implemented.",1008.1513v2
2010-08-12,Structural and dynamical aspects of avoided-crossing resonances in a $3$-level $Λ$ system,"In a recent publication [Phys. Rev. A 79, 065602 (2009)] it was shown that an
avoided-crossing resonance can be defined in different ways, according to
level-structural or dynamical aspects, which do not coincide in general. Here a
simple $3$-level system in a $\Lambda$ configuration is discussed, where the
difference between both definitions of the resonance may be observed. We also
discuss the details of a proposed experiment to observe this difference, using
microwave fields coupling hyperfine magnetic sublevels in alkali atoms.",1008.2078v1
2010-08-12,Strong influence of packing density in terahertz metamaterials,"We investigate the response of terahertz metamaterials made of split-ring
resonators depending on the unit cell density. It is shown that the fundamental
resonance has its highest Q factor for a period of one-third the resonance
wavelength. Increasing or decreasing the period from that optimal period
reduces the Q factor. All observations are explained by understanding radiative
coupling as the dominant loss mechanism at low densities, whereas the strong
inter SRR coupling enhances non-radiative losses at high densities. Our results
allow designing metamaterials with adjustable Q factors and possibly suggesting
that an optimal package density exists to induce the strongest dispersion.",1008.2094v1
2010-08-23,Resonance Effects in the Nonadiabatic Nonlinear Quantum Dimer,"The quantum nonlinear dimer consisting of an electron shuttling between the
two sites and in weak interaction with vibrations, is studied numerically under
the application of a DC electric field. A field-induced resonance phenomenon
between the vibrations and the electronic oscillations is found to influence
the electronic transport greatly. For initially delocalization of the electron,
the resonance has the effect of a dramatic increase in the transport. Nonlinear
frequency mixing is identified as the main mechanism that influences transport.
A characterization of the frequency spectrum is also presented.",1008.3744v1
2010-08-24,Manifestation of geometric resonance in current dependence of AC susceptibility for unshunted array of Nb-AlOx-Nb Josephson junctions,"A pronounced resonance-like structure has been observed in the current
dependence of AC susceptibility for two-dimensional array of unshunted
Nb-AlOx-Nb Josephson junctions. Using a single-plaquette approximation, we were
able to successfully fit our data assuming that resonance structure is related
to the geometric (inductive) properties of the array.",1008.4065v1
2010-09-06,"The Past, Present and Future of the Resonant-Mass Gravitational Wave Detectors","Resonant-mass gravitational waves detectors are reviewed from the concept of
gravitational waves and its mathematical derivation, using Einstein's general
relativity, to the present status of bars and spherical detectors, and their
prospects for the future, which include dual detectors and spheres with
non-resonant transducers. The review covers not only the technical aspects of
detectors and the science that will be done, but also analyses the subject in a
historic perspective, covering the various detection efforts over four decades,
starting from Weber's pioneering work.",1009.1138v1
2010-09-16,Universal Optical Frequency Comb,"We demonstrate that whispering gallery mode resonators can be utilized to
generate optical frequency combs based on four wave mixing process at virtually
any frequency that lies in the transparency window of the resonator host
material. We show theoretically how the morphology of the resonator can be
engineered to produce a family of spectrally equidistant modes with anomalous
group velocity dispersion appropriate for the comb generation. We present
experimental results for a frequency comb centered at 794 nm to support our
theoretical findings.",1009.3286v1
2010-09-18,"Chirikov Diffusion in the Asteroidal Three-Body Resonance (5,-2,-2)","The theory of diffusion in many-dimensional Hamiltonian system is applied to
asteroidal dynamics. The general formulations developed by Chirikov is applied
to the Nesvorn\'{y}-Morbidelli analytic model of three-body (three-orbit)
mean-motion resonances (Jupiter-Saturn-asteroid system). In particular, we
investigate the diffusion \emph{along} and \emph{across} the separatrices of
the (5,-2,-2) resonance of the (490) Veritas asteroidal family and their
relationship to diffusion in semi-major axis and eccentricity. The estimations
of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type
sympletic map and numerical integrations for times up to $10^{8}$ years.",1009.3558v1
2010-09-29,Few-body decay and recombination in nuclear astrophysics,"Three-body continuum problems are investigated for light nuclei of
astrophysical relevance. We focus on three-body decays of resonances or
recombination via resonances or the continuum background. The concepts of
widths, decay mechanisms and dynamic evolution are discussed. We also discuss
results for the triple $\alpha$ decay in connection with $2^+$ resonances and
density and temperature dependence rates of recombination into light nuclei
from $\alpha$-particles and neutrons.",1009.5895v1
2010-10-04,Holography and Anomaly Matching for Resonances,"We derive a universal relation for the transverse part of triangle anomalies
within a class of theories whose gravity dual is described by the
Yang-Mills-Chern-Simons theory. This relation provides a set of sum rules
involving the masses, decay constants and couplings between resonances, and
leads to the formulas for the matrix elements of the vector and axial currents
in the presence of the soft electromagnetic field. We also discuss that this
relation is valid in real QCD at least approximately. This may be regarded as
the anomaly matching for resonances as an analogue of that for the massless
excitations in QCD.",1010.0718v1
2010-10-05,Photoionization Rates of Cs Rydberg Atoms in a 1064 nm Far Off-Resonance Trap,"Experimental measurements of photoionization rates of $nD_{5/2}$ Rydberg
states of Cs ($50 \leq n \leq 75$) in a 1064 nm far off-resonance dipole trap
are presented. The photoionization rates are obtained by measuring the
lifetimes of Rydberg atoms produced inside of a 1064 nm far off-resonance trap
and comparing the lifetimes to corresponding control experiments in a
magneto-optical trap. Experimental results for the control experiments agree
with recent theoretical predictions for Rydberg state lifetimes and measured
photoionization rates are in agreement with transition rates calculated from a
model potential.",1010.0734v1
2010-10-05,Lindblad resonance torques in relativistic discs: I. Basic equations,"Lindblad resonances have been suggested as an important mechanism for angular
momentum transport and heating in discs in binary black hole systems. We
present the basic equations for the torque and heating rate for relativistic
thin discs subjected to a perturbation. The Lindblad resonance torque is
written explicitly in terms of metric perturbations for an equatorial disc in a
general axisymmetric, time-stationary spacetime with a plane of symmetry. We
show that the resulting torque formula is gauge-invariant. Computations for the
Schwarzschild and Kerr spacetimes are presented in the companion paper.",1010.0758v2
2010-10-07,High-energy long-lived resonance of electrons in fractal-like semiconductor heterostructures,"A fractal-like alignment of quantum wells is shown to accommodate resonant
states with long lifetimes. For the parameters of the semiconductor
heterostructure GaAs/Al$_{0.4}$Ga$_{0.6}$As with the well depth 300meV, a
resonant state of the energy as high as 44meV with the lifetime as long as
2.8\{mu}s is shown to be achievable.",1010.1336v1
2010-10-07,Hadronic decay width from finite-volume energy spectrum in lattice QCD,"The standard approach to determine the parameters of a resonance is based on
the study of the volume dependence of the energy spectrum. In this work we
study a non-linear sigma model coupled to a scalar field in which a resonance
emerges. Using an analysis method introduced recently, based on the concept of
probability distribution, it is possible to determine the mass and the width of
the resonance.",1010.1390v1
2010-10-10,Resonant radii of kHz quasi-periodic oscillations in Keplerian discs orbiting neutron stars,"Exchange of dominance between twin kHz quasi-periodic oscillations (QPOs)
observed in some low-mass-X-ray-binaries (LMXB) suggests the possibility of a
resonance between two oscillatory modes. We study the behaviour of the
effective gravitational potential around specific resonant radii, and estimate
the role of the higher-order terms governing the non-linear, anharmonic
forcing. We discuss the impact it has on the mode amplitude in the linear and
non--linear regimes. We also discuss a related possibility of lowering of the
neutron star mass estimates from the highest observed QPO frequencies.",1010.1951v1
2010-10-18,Charge transport through ultrasmall single and double Josephson junctions coupled to resonant modes of the electromagnetic environment,"We have investigated charge transport in ultrasmall superconducting single
and double Josephson junctions coupled to resonant modes of the electromagnetic
environment. We observe pronounced current peaks in the transport
characteristics of both types of devices and attribute them to the process
involving simultaneous tunneling of Cooper pairs and photon emission into the
resonant modes. The experimental data is well reproduced with the theoretical
models.",1010.3617v1
2010-10-18,Study of the double non linear quantum resonances in diatomic molecules,"We study the quantum dynamics of diatomic molecule driven by a circularly
polarized resonant electric field. We look for a quantum effect due to
classical chaos appearing due to the overlapping of nonlinear resonances
associated to the vibrational and rotational motion. We solve the Schr\""odinger
equation associated with the wave function expanded in term of proper
stationary states, $|n>\otimes|lm>$ (vibrational$\otimes$angular momentum
states). Looking for quantum-classic correspondence, we consider the Liouville
dynamics in the two dimensional phase space defined by the coherent -like state
of vibrational states, and it is found some similarities when the quantum
dynamics is pictured in terms of number and phase operators.",1010.3627v1
2010-10-28,A single fermion in a Bose Josephson Junction,"We consider the tunneling properties of a single fermionic impurity immersed
in a Bose-Einstein condensate in a double-well potential. For strong
boson-fermion interaction, we show the existence of a tunnel resonance where a
large number of bosons and the fermion tunnel simultaneously. We give
analytical expressions for the lineshape of the resonance using degenerate
Brillouin-Wigner theory. We finally compute the time-dependent dynamics of the
mixture. Using the fermionic tunnel resonances as beam splitter for
wave-functions, we construct a Mach-Zehnder interferometer that allows complete
population transfer from one well to the other by tilting the double-well
potential and only taking into account the fermion's tunnel properties.",1010.5979v1
2010-11-10,Dynamically generated $N^{*}$ and $Λ^*$ resonances in the hidden charm sector around 4.3 GeV,"The interactions of $\bar{D}\Sigma_{c}$-$\bar D\Lambda_c$,
$\bar{D}^{*}\Sigma_{c}$-$\bar D^*\Lambda_c$, and related strangeness channels,
are studied within the framework of the coupled channel unitary approach with
the local hidden gauge formalism. A series of meson-baryon dynamically
generated relatively narrow $N^*$ and $\Lambda^*$ resonances are predicted
around 4.3 GeV in the hidden charm sector. We make estimates of production
cross sections of these predicted resonances in $\bar{p} p $ collisions for
PANDA at the forthcoming FAIR facility.",1011.2399v2
2010-11-16,Resonant Absorption as Mode Conversion? II. Temporal Ray Bundle,"A fast-wave pulse in a simple, cold, inhomogeneous MHD model plasma is
constructed by Fourier superposition over frequency of harmonic waves that are
singular at their respective Alfven resonances. The pulse partially reflects
before reaching the resonance layer, but also partially tunnels through to it
to mode convert to an Alfven wave. The exact absorption/conversion coefficient
for the pulse is shown to be given precisely by a function of transverse
wavenumber tabulated in Paper I of this sequence, and to be independent of
frequency and pulse width.",1011.3808v1
2010-11-23,Electric-field Manipulation of the Lande' g Tensor of Holes in In0.5Ga0.5As/GaAs Self-assembled Quantum Dots,"The effect of an electric field on spin precession in In0.5Ga0.5As/GaAs
self-assembled quantum dots is calculated using multiband real-space
envelope-function theory. The dependence of the Lande' g tensor on electric
fields should permit high-frequency g tensor modulation resonance, as well as
direct, nonresonant electric-field control of the hole spin. Subharmonic
resonances have also been found in g tensor modulation resonance of the holes,
due to the strong quadratic dependence of components of the hole g tensor on
the electric field.",1011.5014v1
2010-11-24,Fe$^{\bf{15+}}$ dielectronic recombination and the effects of configuration interaction between resonances with different captured electron principal quantum number,"Dielectronic recombination (DR) of Na-like Fe$^{15+}$ forming Mg-like
Fe$^{14+}$ via excitation of a $2l$ core electron has been investigated. We
find that configuration interaction (CI) between DR resonances with different
captured electron principal quantum numbers $n$ can lead to a significant
reduction in resonance strengths for $n \geq 5$. Previous theoretical work for
this system has not considered this form of CI. Including it accounts for most
of the discrepancy between previous theoretical and experimental results.",1011.5410v1
2010-11-26,Prediction of super-heavy $N^*$ and $Λ^*$ resonances with hidden beauty,"The meson-baryon coupled channel unitary approach with the local hidden gauge
formalism is extended to the hidden beauty sector. A few narrow $N^*$ and
$\Lambda^*$ resonances around 11 GeV are predicted as dynamically generated
states from the interactions of heavy beauty mesons and baryons. Production
cross sections of these predicted resonances in $pp$ and $ep$ collisions are
estimated as a guide for the possible experimental search at relevant
facilities.",1011.5743v4
2010-11-26,Non-Weyl resonance asymptotics for quantum graphs in a magnetic field,"We study asymptotical behaviour of resonances for a quantum graph consisting
of a finite internal part and external leads placed into a magnetic field, in
particular, the question whether their number follows the Weyl law. We prove
that the presence of a magnetic field cannot change a non-Weyl asymptotics into
a Weyl one and vice versa. On the other hand, we present examples demonstrating
that for some non-Weyl graphs the ``effective size'' of the graph, and
therefore the resonance asymptotics, can be affected by the magnetic field.",1011.5761v1
2010-11-29,Search for resonant WW and WZ production in ppbar collisions at ?s = 1.96 TeV,"We search for resonant WW or WZ production using up to 5.4 fb-1 of integrated
luminosity collected by the D0 experiment in Run II of the Fermilab Tevatron
Collider. The data are consistent with the standard model background
expectation, and we set limits on a resonance mass using the sequential
standard model (SSM) W' boson and the Randall-Sundrum model graviton G as
benchmarks. We exclude an SSM W' boson in the mass range 180 - 690 GeV and a
Randall-Sundrum graviton in the range 300 - 754 GeV at 95% CL.",1011.6278v1
2010-12-04,Resonance varieties via blowups of P^2 and scrolls,"Conjectures of Suciu relate the fundamental group of the complement M = C^n\A
of a hyperplane arrangement A to the first resonance variety of H^*(M,Z). We
describe a connection between the first resonance variety and the Orlik-Terao
algebra C(A) of the arrangement. In particular, we show that non-local
components of R^1(A) give rise to determinantal syzygies of C(A). As a result,
Proj(C(A)) lies on a scroll, placing geometric constraints on R^1(A). The key
observation is that C(A) is the homogeneous coordinate ring associated to a nef
but not ample divisor on the blowup of P^2 at the singular points of A.",1012.0931v1
2010-12-10,Spin-orbit driven ferromagnetic resonance: A nanoscale magnetic characterisation technique,"We demonstrate a scalable new ferromagnetic resonance (FMR) technique based
on the spin-orbit interaction. An alternating current drives FMR in uniform
ferromagnetic structures patterned from the dilute magnetic semiconductors
(Ga,Mn)As and (Ga,Mn)(As,P). This allows the direct measurement of magnetic
anisotropy coefficients and damping parameters for individual nano-bars. By
analysing the ferromagnetic resonance lineshape, we perform vector magnetometry
on the current-induced driving field, observing contributions with symmetries
of both the Dresselhaus and Rashba spin-orbit interactions.",1012.2397v1
2010-12-13,Optically-Nonactive Assorted Helices Array with Interchangeable Magnetic/Electric Resonance,"We report here the designing of optically-nonactive metamaterial by
assembling metallic helices with different chirality. With linearly polarized
incident light, pure electric or magnetic resonance can be selectively
realized, which leads to negative permittivity or negative permeability
accordingly. Further, we show that pure electric or magnetic resonance can be
interchanged at the same frequency band by merely changing the polarization of
incident light for 90 degrees. This design demonstrates a unique approach to
construct metamaterial.",1012.2623v1
2010-12-13,Chiral quark model approach for the study of baryon resonances,"We report the chiral quark model approach for the study of baryon resonances
in meson photoproduction and meson-nucleon scattering processes. Focussing on
the $\pi N$ and $K N$ scatterings, we show that the cross sections near
threshold can be well accounted for by the chiral quark model with only few
parameters. The $S$-wave dominance in both $\pi^- p\to \eta n$ and $K^- p\to
\Sigma^0\pi^0$ can be well understood in the quark model framework. In
particular, the quark model provides a constraint on the relative signs for
resonance coupling form factors, which seems to be consistent with results from
isobaric models.",1012.2891v1
2010-12-16,Tunable pulse delay and advancement in a coupled nanomechanical resonator-superconducting microwave cavity system,"We theoretically study the transmission of a weak probe field under the
influence of a strong pump field in a coupled nanomechanical
resonator-superconducting microwave cavity system. Using the standard
input-output theory, we find that both pulse delay (slow light effect) and
advancement (fast light effect) of the probe field can appear in this coupled
system provided that we choose the suitable detuning of the pump field from
cavity resonance. The magnitude of the delay (advancement) can be tuned
continuously by adjusting the power of the pump field. This technique
demonstrates great potential in applications including microwave phase shifter
and delay line.",1012.3598v1
2010-12-16,Schrodinger operators and the distribution of resonances in sectors,"The purpose of this paper is to give some refined results about the
distribution of resonances in potential scattering. We use techniques and
results from one and several complex variables, including properties of
functions of completely regular growth. This enables us to find asymptotics for
the distribution of resonances in sectors for certain potentials and for
certain families of potentials.",1012.3767v2
2010-12-17,Collective electromagnetic response of discrete metamaterial systems,"We develop a general formalism to describe the interactions between a
discrete set of plasmonic resonators mediated by the electromagnetic field. The
resulting system of equations for closely-spaced meta-atoms represents a
cooperative metamaterial response and we find that collective interactions
between asymmetric split-ring resonators arranged in a 2D lattice explains the
recent experimental observations of system-size dependent narrowing of the
transmission resonance linewidth. We further show that this cooperative
narrowing depends sensitively on the lattice spacing.",1012.3928v1
2011-01-05,Effects of La non-magnetic impurities on the spin resonance of CeCoIn$_{5}$,"The influence of La non magnetic impurities on the spin dynamics of
CeCoIn$_{5}$ was studied by inelastic neutron scattering. In La-substituted
systems, the spin resonance peak (observed at $\Omega_{res}=0.55 meV$ in the
pure system) is shifted to lower energies but the ratio
$\Omega_{res}/k_{B}T_{c}$ remains unchanged. The excitation broadens till it
reaches 0.3 meV equal to the value of the quasi-elastic signal in the normal
state. The evolution of La substitution is compared with the evolution of the
magnetic resonance in Ni and Zn substituted YBa$_{2}$Cu$_{3}$O$_{7}$.",1101.1018v1
2011-01-06,Enhanced second harmonic generation from resonant GaAs gratings,"We study second harmonic generation in nonlinear, GaAs gratings. We find
large enhancement of conversion efficiency when the pump field excites the
guided mode resonances of the grating. Under these circumstances the spectrum
near the pump wavelength displays sharp resonances characterized by dramatic
enhancements of local fields and favorable conditions for second harmonic
generation, even in regimes of strong linear absorption at the harmonic
wavelength. In particular, in a GaAs grating pumped at 1064nm, we predict
second harmonic conversion efficiencies approximately five orders of magnitude
larger than conversion rates achievable in either bulk or etalon structures of
the same material.",1101.1124v1
2011-01-07,Interaction of the Electromagnetic p-Wave with Thin Metal Film in the Field of Resonant Frequencies,"It is shown that for thin metallic films thickness of which does not exceed
thickness of skin layer, the problem allows analytical solution. In the field
of resonant frequencies the analysis of dependence of coefficients of
transmission, reflection and absorbtion on an electromagnetic wave is carried
out. Dependence on pitch angle, thickness of the layer and coefficient of
specular reflection and on effective electron collision frequency is carried
out. The formula for contactless determination (calculation) of a thickness of
a film by observable resonant frequencies is deduced.",1101.1453v1
2011-01-13,Stability Condition of a Strongly Interacting Boson-Fermion Mixture across an Inter-Species Feshbach Resonance,"We study the properties of dilute bosons immersed in a single component Fermi
sea across a broad boson-fermion Feshbach resonance. The stability of the
mixture requires that the bare interaction between bosons exceeds a critical
value, which is a universal function of the boson-fermion scattering length,
and exhibits a maximum in the unitary region. We calculate the quantum
depletion, momentum distribution and the boson contact parameter across the
resonance. The transition from condensate to molecular Fermi gas is also
discussed.",1101.2492v2
2011-01-17,Improving the performance of superconducting microwave resonators in magnetic fields,"The operation of superconducting coplanar waveguide cavities, as used for
circuit quantum electrodynamics and kinetic inductance detectors, in
perpendicular magnetic fields normally leads to a reduction of the device
performance due to energy dissipating Abrikosov vortices. We experimentally
investigate the vortex induced energy losses in such Nb resonators with
different spatial distributions of micropatterned pinning sites (antidots) by
transmission spectroscopy measurements at 4.2 K. In comparison to resonators
without antidots we find a significant reduction of vortex induced losses and
thus increased quality factors over a broad range of frequencies and applied
powers in moderate fields.",1101.3185v1
2011-01-25,Onset and saturation of ion heating by odd-parity rotating-magnetic-fields in a field-reversed configuration,"Heating of figure-8 ions by odd-parity rotating magnetic fields ($RMF_o$)
applied to an elongated field-reversed configuration (FRC) is investigated. The
largest energy gain occurs at resonances ($s \equiv \omega_R/ \omega$) of the
$RMF_o$ frequency, $\omega_R$, with the figure-8 orbital frequency, $\omega$,
and is proportional to $s^2$ for $s-even$ resonances and to $s$ for $s-odd$
resonances. The threshold for the transition from regular to stochastic orbits
explains both the onset and saturation of heating. The FRC magnetic geometry
lowers the threshold for heating below that in the tokamak by an order of
magnitude.",1101.4774v1
2011-02-08,Space-time resonances,"This article is a short exposition of the space-time resonances method. It
was introduced by Masmoudi, Shatah, and the author, in order to understand
global existence for nonlinear dispersive equations, set in the whole space,
and with small data. The idea is to combine the classical concept of
resonances, with the feature of dispersive equations: wave packets propagate at
a group velocity which depends on their frequency localization. The analytical
method which follows from this idea turns out to be a very general tool.",1102.1695v1
2011-02-10,Circularly Polarized Resonant Rayleigh Scattering and Skyrmions in the $ν$ = 1 Quantum Hall Ferromagnet,"We use the circularly polarized resonant Rayleigh scattering (RRS) to study
the quantum Hall ferromagnet at $\nu$ = 1. At this filling factor we observe a
right handed copolarized RRS which probes the Skyrmion spin texture of the
electrons in the photoexcited grounds state. The resonant scattering is not
present in the left handed copolarization, and this can be related to the
correlation between Skymionic effects, screening and spin wave excitations.
These results evidence that RRS is a valid method for the study of the spin
texture of the quantum Hall states.",1102.2185v2
2011-02-17,Ground State of the Quasi-1D \bvs\ resolved by Resonant Magnetic X-ray Scattering,"Resonant-magnetic x-ray scattering (RMXS) near the vanadium
$L_{2,3}$-absorption edges has been used to investigate the low temperature
magnetic structure of high quality \bvs\ single crystals. Below $T_N$ = 31 K,
the strong resonance revealed a triple-incommensurate magnetic ordering at wave
vector (0.226 0.226 $\xi$) in the hexagonal notation, with $\xi$ = 0.033. The
simulations of the experimental RMXS spectra with a time-dependent density
functional theory indicate an antiferromagnetic order with the spins polarized
along $a$ in the monoclinic structure.",1102.3589v1
2011-02-28,Effect of three-pion unitarity on resonance poles from heavy meson decays,"We study the final state interaction in 3-pion decay of meson resonances at
the Excited Baryon Analysis Center (EBAC) of JLab. We apply the dynamical
coupled-channels formulation which has been extensively used by EBAC to extract
N* information. The formulation satisfies the 3-pion unitarity condition which
has been missed in the existing works with the isobar models. We report the
effect of the 3-pion unitarity on the meson resonance pole positions and Dalitz
plot.",1102.5753v1
2011-03-04,Electrical conductivity and resonant states of doped graphene considering next-nearest neighbor interaction,"The next-nearest neighbor interaction (NNN) is included in a tight-binding
calculation of the electronic spectrum and conductivity of doped graphene. As a
result, we observe a wide variation of the conductivity behavior, since the
Fermi energy and the resonance peak are not shifted by the same amount. Such
effect can have a profound effect in the idea of explaining the minimal
conductivity of graphene as a consequence of impurities or defects. Finally, we
also estimate the mean free path and relaxation time due to resonant impurity
scattering.",1103.0960v1
2011-03-10,Shallow Efimov tetramer as inelastic virtual state and resonant enhancement of the atom-trimer relaxation,"We use exact four-boson scattering equations in the momentum-space framework
to study the universal properties of shallow Efimov tetramers and their
dependence on the two-boson scattering length. We demonstrate that, in contrast
to previous predictions, the shallow tetramer in a particular experimentally
unexplored regime is not an unstable bound state but an inelastic virtual
state. This leads to a resonant behaviour of the atom-trimer scattering length
and thereby to a resonant enhancement of the trimer relaxation in ultracold
atom-trimer mixtures.",1103.2107v2
2011-03-14,Diffusion-induced bistability of driven nanomechanical resonators,"We study nanomechanical resonators with frequency fluctuations due to
diffusion of absorbed particles. The diffusion depends on the vibration
amplitude through inertial effect. We find that, if the diffusion coefficient
is sufficiently large, the resonator response to periodic driving displays
bistability. The lifetime of the coexisting vibrational states scales
exponentially with the diffusion coefficient. It also displays a characteristic
scaling dependence on the distance to bifurcation points.",1103.2758v1
2011-03-18,"Extended WKB method, resonances and supersymmetric radial barriers","Semiclassical approximations are implemented in the calculation of position
and width of low energy resonances for radial barriers. The numerical
integrations are delimited by t/T<<8, with t the period of a classical particle
in the barrier trap and T the resonance lifetime. These energies are used in
the construction of `haired' short range potentials as the supersymmetric
partners of a given radial barrier. The new potentials could be useful in the
study of the transient phenomena which give rise to the Moshinsky's diffraction
in time.",1103.3692v1
2011-03-22,Resonant Photoelectron Diffraction with circularly polarized light,"Resonant angle scanned x-ray photoelectron diffraction (RXPD) allows the
determination of the atomic and magnetic structure of surfaces and interfaces.
For the case of magnetized nickel the resonant L2 excitation with circularly
polarized light yields electrons with a dichroic signature from which the
dipolar part may be retrieved. The corresponding L2MM and L3MM Auger electrons
carry different angular momenta since their source waves rotate the dichroic
dipole in the electron emission patterns by distinct angles.",1103.4280v1
2011-03-24,Effect of nonadiabatic spin transfer torque on domain wall resonance frequency and mass,"The dynamics of a magnetic domain wall in a semi circular nanowire loop is
studied by an analytical model and micromagnetic simulations. We find a damped
sinusoidal oscillation of the domain wall for small displacement angles around
its equilibrium position under an external magnetic field in the absence of
currents. By studying the effect of current induced nonadiabatic spin transfer
torque on the magnetic domain wall resonance frequency and mass, a red shift is
found in the resonance frequency and domain wall mass increases by increasing
the ratio of nonadiabatic spin torque to adiabatic contribution above 1.",1103.4670v1
2011-03-25,Temperature dependence of spin resonance in cobalt substituted NiZnCu ferrites,"Cobalt substitutions were investigated in Ni0.4Zn0.4Cu0.2Fe2O4 ferrites,
initial complex permeability was then measured from 1 MHz to 1 GHz. It appears
that cobalt substitution led to a decrease in the permeability and an increase
in the \mus\timesfr factor. As well, it gave to the permeability spectrum a
sharp resonance character. We also observed a spin reorientation occurring at a
temperature depending on the cobalt content. Study of the complex permeability
versus temperature highlighted that the most resonant character was obtained at
this temperature. This shows that cobalt contribution to second order
magnetocrystalline anisotropy plays a leading role at this temperature.",1103.5024v1
2011-04-12,Interactions and magnetic moments near vacancies and resonant impurities in graphene,"The effect of electronic interactions in graphene with vacancies or resonant
scatterers is investigated. We apply dynamical mean-field theory in combination
with quantum Monte Carlo simulations, which allow us to treat
non-perturbatively quantum fluctuations beyond Hartree-Fock approximations. The
interactions narrow the width of the resonance and induce a Curie magnetic
susceptibility, signaling the formation of local moments. The absence of
saturation of the susceptibility at low temperatures suggests that the coupling
between the local moment and the conduction electrons is ferromagnetic.",1104.2207v1
2011-04-15,Top quark asymmetry and dijet resonances,"CDF recently reported an anomaly in the $m_{jj}$ distribution of dijet events
produced in association with a $W$ boson. If this anomaly is associated with a
new flavor conserving vector resonance, $V$, one might have expected to observe
effects in the analogous $m_{jj}$ distribution produced in association with a
$\gamma$. No such excess is observed. A single $u-t-V$ flavor changing
coupling, however, can contribute to the $m_{jj}$ anomaly while being
consistent with other resonance searches. Furthermore, it gives a potential
explanation of the observed forward-backward asymmetry in top quark production.",1104.3139v2
2011-04-18,Interacting double dark resonances in a hot atomic vapor of helium,"We experimentally and theoretically study two different tripod configurations
using metastable helium ($^4$He*), with the probe field polarization
perpendicular and parallel to the quantization axis, defined by an applied weak
magnetic field. In the first case, the two dark resonances interact
incoherently and merge together into a single EIT peak with increasing coupling
power. In the second case, we observe destructive interference between the two
dark resonances inducing an extra absorption peak at the line center.",1104.3427v2
2011-04-29,Surface plasmon resonances of clustered nanoparticles,"Linear clusters made by tightly connecting two or more metallic nanoparticles
have new types of surface plasmon resonances as compared to isolated
nanoparticles. These new resonances are related to the size of the junction and
to the number of interconnected particles and have direct interpretation as
eigenmodes of a Boundary Integral Equation (BIE). This formulation allows
effective separation of geometric and shape contribution from electric
properties of the constituents. Results for particles covered by a thin shell
are also provided. In addition, the present analysis sheds a new light on the
interpretation of recent experiments from literature.",1104.5666v1
2011-05-04,Spectral data for doubly excited states of helium with non-zero total angular momentum,"A spectral approach is used to evaluate energies and widths for a wide range
of singlet and triplet resonance states of helium. Data for total angular
momentum $L=1,...,4$ is presented for resonances up to below the 5th single
ionization threshold. In addition the expectation value of $\cos(\theta_{12})$
is given for the calculated resonances.",1105.0742v1
2011-05-06,Radio frequency readout of electrically detected magnetic resonance in phosphorus-doped silicon MOSFETs,"We demonstrate radio frequency (RF) readout of electrically detected magnetic
resonance in phosphorus-doped silicon metal-oxide field-effecttransistors
(MOSFETs), operated at liquid helium temperatures. For the first time, the Si:P
hyperfine lines have been observed using radio frequency reflectometry, which
is promising for high-bandwidth operation and possibly time-resolved detection
of spin resonance in donor-based semiconductor devices. Here we present the
effect of microwave (MW) power and MOSFET biasing conditions on the EDMR
signals.",1105.1235v1
2011-05-11,Dispersion and damping of multi-quantum well polaritons from resonant Brillouin scattering by folded acoustic modes,"We report on confined exciton resonances of acoustic and folded acoustic
phonon light scattering in a GaAs/AlAs multi-quantum-well. Significant
variations of the line shifts and widths are observed across the resonance and
quantitatively reproduced in terms of the polariton dispersion. This high
resolution Brillouin study brings new unexpectedly detailed informations on the
polariton dynamics in confined systems.",1105.2229v1
2011-05-17,Periodic Jacobi operator with finitely supported perturbations: the inverse resonance problem,"We consider a periodic Jacobi operator $H$ with finitely supported
perturbations on ${\Bbb Z}.$ We solve the inverse resonance problem: we prove
that the mapping from finitely supported perturbations to the scattering data:
the inverse of the transmission coefficient and the Jost function on the right
half-axis, is one-to-one and onto. We consider the problem of reconstruction of
the scattering data from all eigenvalues, resonances and the set of zeros of
$R_-(\lambda)+1,$ where $R_-$ is the reflection coefficient.",1105.3397v2
2011-05-23,Transmission enhancement in three-dimensional rolled-up plasmonic metamaterials containing optically active quantum wells,"We investigate three-dimensional rolled-up metamaterials containing optically
active quantum wells and metal gratings supporting surface plasmon polarition
resonances. Finite-difference time-domain simulations show that by matching the
surface plasmon polarition resonance with the active wavelength regime of the
quantum well a strong transmission enhancement is observed when illuminating
the sample with p-polarized radiation. This transmission enhancement is further
increased by taking advantage of the Fabry-Perot resonances of the structure.",1105.4541v1
2011-05-25,A Novel Source of Tagged Low-Energy Nuclear Recoils,"For sufficiently wide resonances, nuclear resonance fluorescence behaves like
elastic photo-nuclear scattering while retaining the large cross-section
characteristic of resonant photo-nuclear absorption. We show that NRF may be
used to characterize the signals produced by low-energy nuclear recoils by
serving as a novel source of tagged low-energy nuclear recoils. Understanding
these signals is important in determining the sensitivity of direct WIMP
dark-matter and coherent neutrino-nucleus scattering searches.",1105.5156v1
2011-05-30,Calculating resonance positions and widths using the Siegert approximation method,"Here we present complex resonance states (or Siegert states), that describe
the tunneling decay of a trapped quantum particle, from an intuitive point of
view which naturally leads to the easily applicable Siegert approximation
method that can be used for analytical and numerical calculations of complex
resonances of both the linear and nonlinear Schr\""odinger equation. Our
approach thus complements other treatments of the subject that mostly focus on
methods based on continuation in the complex plane or on semiclassical
approximations.",1105.5994v2
2011-05-31,Temperature measurement and stabilization in a birefringent whispering gallery resonator,"Temperature measurement with nano-Kelvin resolution is demonstrated at room
temperature, based on the thermal dependence of an optical crystal anisotropy
in a high quality whispering gallery resonator. As the resonator's TE and TM
modes frequencies have different temperature coefficients, their differential
shift provides a sensitive measurement of the temperature variation, which is
used for active stabilization of the temperature.",1105.6350v1
2011-06-09,Wave approach for the resonances of rectangular and triangular membranes,"This study develops a ray technique for determining the resonance frequencies
of triangular membranes. The technique is demonstrated for homogenous
rectangular and triangular membranes with fixed boundaries. Where possible, the
results are compared with exact calculations. The membrane resonances are
calculated using an equivalent string whose length is proportional to the
reciprocal of the length of closed paths starting from an arbitrary point
within the membrane. Closed paths are ray paths which arrive back at the
starting point going in the same direction.",1106.1829v1
2011-06-10,Discrete-time quadrature feedback cooling of a radio-frequency mechanical resonator,"We have employed a feedback cooling scheme, which combines high-frequency
mixing with digital signal processing. The frequency and damping rate of a 2
MHz micromechanical resonator embedded in a dc SQUID are adjusted with the
feedback, and active cooling to a temperature of 14.3 mK is demonstrated. This
technique can be applied to GHz resonators and allows for flexible control
strategies.",1106.2106v1
2011-07-04,Andreev reflection and the semiclassical Bogoliubov-de Gennes Hamiltonian: resonant states,"We present a semi-classical analysis of the opening of superchannels in gated
mesoscopic SNS junctions. For perfect junctions (i.e. hard-wall potential),
this was considered by Chtchelkatchev, Lesovik and Blatter in the framework of
scattering matrices. Here we allow for imperfections in the junction, so that
the complex order parameter continues as a smooth function, which is a constant
in the superconducting banks, and vanishes rapidly inside the lead. We obtain
quantization rules for resonant Andreev states near energy E close to the Fermi
level, including the determination of the resonance width.",1107.0673v1
2011-07-11,Analytical Approximations of Whispering gallery Modes in Anisotropic Ellipsoidal Resonators,"Numerical evolutions of whispering gallery modes of both isotropic and
anisotropic spheroidal resonators are presented and used to build analytical
approximations of these modes. Such approximations are carried out mainly to
have the possibility to have a manageable analytic formulas for the eigenmodes
and eigenfrequencies of anisotropic resonators. A qualitative analysis of
ellipsoidal anisotropic modes in term of superposition of spherical modes is
also presented.",1107.2044v2
2011-07-28,Enhanced four-wave mixing via crossover resonance in cesium vapor,"We report on the observation of enhanced four-wave mixing via crossover
resonance in a Doppler broadened cesium vapor. Using a single laser frequency,
a resonant parametric process in a double-$\Lambda$ level configuration is
directly excited for a specific velocity class. We investigate this process in
different saturation regimes and demonstrate the possibility of generating
intensity correlation and anti-correlation between the probe and conjugate
beams. A simple theoretical model is developed that accounts qualitatively well
to the observed results.",1107.5768v1
2011-07-29,Sub-kHz-level relative stabilization of an intracavity doubled continuous wave optical parametric oscillator using Pound-Drever-Hall scheme,"We report the relative frequency stabilization of an intracavity frequency
doubled singly resonant optical parametric oscillator on a Fabry-Perot\'etalon.
The red/orange radiation produced by the frequency doubling of the intracavity
resonant idler is stabilized using the Pound-Drever-Hall locking technique. The
relative frequency noise of this orange light, when integrated from 1 Hz to 50
kHz, corresponds to a standard deviation of 700 Hz. The frequency noise of the
pump laser is shown experimentally to be transferred to the non resonant signal
beam.",1107.5906v1
2011-07-29,The Regge-plus-resonance model for kaon production on the proton and the neutron,"The Regge-plus-resonance (RPR) framework for kaon photoproduction on the
proton and the neutron is an economical single-channel model with very few
parameters. Not only does the RPR model allow one to extract resonance
information from the data, it has predictive power. As an example we show that
the RPR model makes fair predictions for the $p(e,e'K^{+})\Lambda$ and the
$n(\gamma,K^{+})\Sigma ^{-}$ observables starting from amplitudes optimized for
the reaction $p(\gamma, K ^{+})\Lambda$ and $p(\gamma,K^{+})\Sigma ^{0}$
respectively.",1107.5908v1
2011-07-30,Electromagnetic response of a metamaterial with field-gradient-induced transparency,"We investigate a dynamically controllable electromagnetically induced
transparency-like metamaterial. The unit structure of the metamaterial consists
of a low-quality-factor resonator and a high-quality-factor resonator. The
field gradient of the incident electromagnetic wave in the transverse direction
induces coupling between these two types of resonators and causes a
transparency phenomenon. We present the simulation and experimental results for
the dynamic control of the electromagnetic response.",1108.0054v1
2011-08-05,Thermoelectric detection of ferromagnetic resonance of a nanoscale ferromagnet,"We present thermoelectric measurements of the heat dissipated due to
ferromagnetic resonance of a Permalloy strip. A microwave magnetic field,
produced by an on-chip coplanar strip waveguide, is used to drive the
magnetization precession. The generated heat is detected via Seebeck
measurements on a thermocouple connected to the ferromagnet. The observed
resonance peak shape is in agreement with the Landau-Lifshitz-Gilbert equation
and is compared with thermoelectric finite element modeling. Unlike other
methods, this technique is not restricted to electrically conductive media and
is therefore also applicable to for instance ferromagnetic insulators.",1108.1286v1
2011-08-09,Magnetic resonance from the interplay of frustration and superconductivity,"Motivated by the iron-based superconductors, we develop a self-consistent
electronic theory for the itinerant spin excitations in the regime of
coexistence of the antiferromagnetic stripe order with wavevector ${\bf Q}_{1}
= (\pi,0)$ and $s^{+-}$ superconductivity. The onset of superconductivity leads
to the appearance of a {\em magnetic} resonance near the wavevector ${\bf
Q}_{2} = (0,\pi)$ where magnetic order is absent. This resonance is isotropic
in spin space, unlike the excitations near ${\bf Q}_{1}$ where the magnetic
Goldstone mode resides. We discuss several features which can be observed
experimentally.",1108.2046v1
2011-08-12,Spectroscopy of mechanical dissipation in micro-mechanical membranes,"We measure the frequency dependence of the mechanical quality factor (Q) of
SiN membrane oscillators and observe a resonant variation of Q by more than two
orders of magnitude. The frequency of the fundamental mechanical mode is tuned
reversibly by up to 40% through local heating with a laser. Several distinct
resonances in Q are observed that can be explained by coupling to membrane
frame modes. Away from the resonances, the background Q is independent of
frequency and temperature in the measured range.",1108.2617v1
2011-08-16,Nanomechanical detection of nuclear magnetic resonance using a silicon nanowire oscillator,"We report the use of a silicon nanowire mechanical oscillator as a
low-temperature nuclear magnetic resonance force sensor to detect the
statistical polarization of 1H spins in polystyrene. Under operating
conditions, the nanowire experienced negligible surface-induced dissipation and
exhibited a nearly thermally-limited force noise of 1.9 aN^2/Hz in the
measurement quadrature. In order to couple the 1H spins to the nanowire
oscillator, we have developed a new magnetic resonance force detection protocol
which utilizes a nanoscale current-carrying wire to produce large
time-dependent magnetic field gradients as well as the rf magnetic field.",1108.3263v1
2011-08-30,Meson-baryon interactions and baryon resonances,"Meson-baryon interactions are the fundamental building blocks to study the
structures of baryon resonances and meson properties in few-body nuclear
systems. We review the recent progress in the investigation of the meson-baryon
interaction in the strangeness S=-1 sector and the structure of the
Lambda(1405) resonance. In particular, we present an attempt to construct a
realistic Kbar N-pi Sigma interaction in chiral SU(3) dynamics in response to
the precise measurement of the kaonic hydrogen, and discuss the subthreshold
extrapolation of the Kbar N interaction with the information of the pi Sigma
channel.",1108.5804v1
2011-08-30,Application of generalized method of eigenoscillations to problems of nanoplasmonics,"A version of generalized eigenoscillation method is applied to the problem
about resonant effects in metallic nanoparticles. An approach is proposed, that
permits to avoid calculating all higher eigenoscillations except the resonant
one. An algorithm for determination of the resonant eigenoscillation, based on
the Galerkin procedure, is described in details for the case of bodies of
revolution. Model numerical results are presented.",1108.5967v1
2011-09-01,Internal structure of the Lambda(1405) resonance probed in chiral unitary amplitude,"The internal structure of the resonant Lambda(1405) state is investigated
based on meson-baryon coupled-channels chiral dynamics. We evaluate
Lambda(1405) form factors which are extracted from current-coupled scattering
amplitudes in meson-baryon degrees of freedom. Using several probe currents and
channel decomposition, we find that the resonant Lambda(1405) state is
dominantly composed of widely spread Kbar around N, with escaping pi Sigma
component.",1109.0061v2
2011-09-02,Fano Mechanism of the Giant Magnetoresistance Formation in a Spin Nanostructure,"It is shown that, upon the electron quantum transport via the nanostructure
containing a spin dimer, the spin-flip processes caused by the s-f exchange
interaction between electron and dimer spins lead to the Fano resonance
effects. An applied magnetic field eliminates degeneracy of the upper triplet
states of the dimer, changes the conditions for implementation of the Fano
resonances and antiresonances, and induces the new Fano resonance and
antiresonance. It results in the occurrence of a sharp peak and dip in the
energy dependence of transmittance. These effects strongly modify the
current--voltage characteristic of the spin-dimer structure in a magnetic field
and form giant magnetoresistance.",1109.0391v1
2011-09-04,Tunable Dual-band IFA Antenna using LC Resonators,"A tunable dual-band inverted F antenna (IFA) is presented in this paper. By
placing a LC resonator on the radiating arm, dual-band characteristic is
achieved. Especially, the capacitor in the resonator is a tunable thin-film BST
capacitor, which has a 3.3:1 tuning ratio. The capacitance of the BST
capacitors can be tuned by an external DC bias voltage. By varying the
capacitance, both the lower band and the upper band of the IFA antenna can be
tuned. And the total bandwidth can cover six systems, i.e., GSM-850, GSM-900,
GPS, DCS, PCS, and UMTS.",1109.0762v1
2011-09-05,Exceptional points in bichromatic Wannier-Stark systems,"The resonance spectrum of a tilted periodic quantum system for a bichromatic
periodic potential is investigated. For such a bichromatic Wannier-Stark system
exceptional points, degeneracies of the spectrum, can be localized in parameter
space by means of an efficient method for computing resonances. Berry phases
and Petermann factors are analyzed. Finally the influence of a nonlinearity of
the Gross-Pitaevskii type on the resonance crossing scenario is briefly
discussed.",1109.0808v1
2011-09-05,Searches for high mass dilepton resonances in pp collisions at sqrt(s) = 7 TeV with the ATLAS Experiment,"The ATLAS detector has been used to search for high mass ee or mumu
resonances, such as new heavy neutral gauge bosons. Over 1 fb^{-1} of
proton-proton collisions at s = 7 TeV recorded by the ATLAS experiment are used
to search for a high mass state decaying to dilepton pairs. No excess over
Standard Model expectations is observed, and limits are placed on benchmark
models predicting spin-1 and spin-2 resonances.",1109.0934v1
2011-09-06,Correlation between lasing and transport properties in a quantum dot-resonator system,"We study a double quantum dot system coherently coupled to an electromagnetic
resonator. By suitably biasing the system, a population inversion can be
created between the dot levels. The resulting lasing state exists within a
narrow resonance window, where the transport current correlates with the lasing
state. It allows probing the lasing state via a current measurement. Moreover,
the resulting narrow current peak opens perspective for applications of the
setup for high resolution measurements.",1109.1166v1
2011-09-09,Resonance Contribution to Radiative Neutron Capture on Lithium-7,"Using halo effective field theory, we provide a model-independent calculation
of the radiative neutron capture on lithium-7 over an energy range where the
contribution from the 3+ resonance becomes important. One finds that a
satisfactory description of the capture reaction, in the present
single-particle approximation, suggests the use of a resonance width about
three times larger than the experimental value. We also present power counting
arguments that establish a hierarchy for electromagnetic one- and two-body
currents.",1109.1876v1
2011-09-19,Quasinormal resonances of a massive scalar field in a near-extremal Kerr black hole spacetime,"The fundamental resonances of near-extremal Kerr black holes due to massive
scalar perturbations are derived {\it analytically}. We show that there exists
a critical mass parameter, $\mu_c$, below which increasing the mass $\mu$ of
the field increases the oscillation frequency $\Re(\omega)$ of the resonance.
On the other hand, above the critical field mass increasing the mass $\mu$
increases the damping rate $\Im(\omega)$ of the mode. We confirm our analytical
results by numerical computations.",1109.4080v1
2011-09-23,Restoring of optical resonances in subwavelength hyperbolic etalons,"We give a solution to the fundamental problem of restoring optical resonances
in deep subwavelength structures by resorting to indefinite metamaterials. We
prove that a nanometric thick hyperbolic slab with very small permittivities
exhibits etalon resonances and provides high-contrast optical angular
filtering. This is possible since the hyperbolic dispersion allows the vacuum
radiation to couple with medium plane waves with longitudinal wavenumbers large
enough to yield optical standing waves within the nanometric slab thickness.
Our findings can form the basis of a novel way for shrinking optical devices
down to the deep subwavelength scale.",1109.5101v1
2011-09-28,The effect of confinement on stochastic resonance in continuous bistable systems,"Using the input energy per cycle as a quantifier of stochastic resonance
(SR), we show that SR is observed in superharmonic (hard) potentials. However,
it is not observed in subharmonic (soft) potentials, even though the potential
is bistable. These results are consistent with recent observations based on
amplitude of average position as a quantifier. In both soft and hard
potentials, we observe resonance phenomenon as a function of the driving
frequency. The nature of probability distributions of average work are
qualitatively different for soft and hard potentials.",1109.6311v2
2011-09-28,Steady-state entanglement of a Bose-Einstein condensate and a nanomechanical resonator,"We analyze the steady-state entanglement between Bose-Einstein condensate
trapped inside an optical cavity with a moving end mirror (nanomechanical
resonator) driven by a single mode laser. The quantized laser field mediates
the interaction between the Bose-Einstein condensate and nanomechanical
resonator. In particular, we study the influence of temperature on the
entanglement of the coupled system, and note that the steady-state entanglement
is fragile with respect to temperature.",1109.6316v1
2011-10-07,Entropic Spectral Broadening in Carbon Nanotube Resonators,"We simulated the behavior of suspended carbon-nanotube (CNT) resonators over
a broad range of temperatures to address the unexplained spectral broadening
and frequency shifts seen in experiments. We find that thermal fluctuations
induce strong coupling between resonance modes. This effect leads to spectral
fluctuations which readily account for the experimentally observed quality
factors $Q\sim100$ at $300\ K$. Using a mean field approach to describe
entropic fluctuations we analytically calculate $Q$ and frequency shifts in
tensioned and buckled CNTs and find excellent agreement with simulations.",1110.1517v1
2011-10-07,Controlling collisional decoherence of ultracold molecules in superposition states by an external magnetic field,"We present expressions demonstrating that collisional decoherence of
ultracold atoms or molecules in a coherent superposition of non-degenerate
quantum states is suppressed when both the real and imaginary parts of the
scattering lengths for the states in the coherent superposition are equal. We
show that the rate of collisional decoherence can be enhanced or suppressed by
varying an external magnetic field near a Feshbach resonance. For some
resonances, the suppression is very dramatic. We propose a method for measuring
the scattering length of ultracold particles in excited quantum states
exhibiting Feshbach resonances.",1110.1675v2
2011-10-16,Optomechanically induced non-reciprocity in microring resonators,"We describe a new approach for on-chip optical non-reciprocity which makes
use of strong optomechanical interaction in microring resonators. By optically
pumping the ring resonator in one direction, the optomechanical coupling is
only enhanced in that direction, and consequently, the system exhibits a
non-reciprocal response. For different configurations, this system can function
either as an optical isolator or a coherent non-reciprocal phase shifter. We
show that the operation of such a device on the level of single-photon could be
achieved with existing technology.",1110.3538v2
2011-10-17,Evidence of the non-strange partner of pentaquark from the elementary $K^+Λ$ photoproduction,"The existence of the $J^p=1/2^+$ narrow resonance predicted by the chiral
soliton model has been investigated by utilizing the new kaon photoproduction
data. For this purpose, we have constructed two phenomenological models, which
are able to describe kaon photoproduction from threshold up to W=1730 MeV. By
varying the resonance mass, width, and $K\Lambda$ branching ratio in this
energy range we found that the most convincing mass of this resonance is 1650
MeV. Using this result we estimate the masses of other antidecuplet family
members.",1110.3552v1
2011-10-20,Scattering phase shift and resonance properties on the lattice: an introduction,"We describe the method for extracting the elastic scattering phase shift from
a lattice simulation at an introductory level, for non-lattice practitioners.
We consider the scattering in a resonant channel, where the resulting phase
shift delta(s) allows the lattice determination of the mass and the width of
the resonance from a Breit-Wigner type fit. We present the method for the
example of P-wave pi-pi scattering in the rho meson channel.",1110.4520v1
2011-10-28,Reducing vortex losses in superconducting microwave resonators with microsphere patterned antidot arrays,"We experimentally investigate the vortex induced energy losses in niobium
coplanar waveguide resonators with and without quasihexagonal arrays of
nanoholes (antidots), where large-area antidot patterns have been fabricated
using self-assembling microsphere lithography. We perform transmission
spectroscopy experiments around 6.25 and 12.5 GHz in magnetic field cooling and
zero field cooling procedures with perpendicular magnetic fields up to B=27 mT
at a temperature T=4.2 K. We find that the introduction of antidot arrays into
resonators reduces vortex induced losses by more than one order of magnitude.",1110.6332v1
2011-12-01,Two-dimensional double-quantum spectra reveal collective resonances in an atomic vapor,"We report the observation of double-quantum coherence signals in a gas of
potassium atoms at twice the frequency of the one-quantum coherences. Since a
single atom does not have a state at the corresponding energy, this observation
must be attributed to a collective resonance involving multiple atoms. These
resonances are induced by weak inter-atomic dipole-dipole interactions, which
means that the atoms cannot be treated in isolation, even at a low density of
$10^{12}$ cm$^{-3}$.",1112.0336v1
2011-12-07,Creation of particle-hole superposition states in graphene at multiphoton resonant excitation by laser radiation,"Nonlinear dynamics of establishment of electron-hole coherent superpositions
states in graphene by multiphoton resonant excitation of interband transitions
in laser fields is considered. The single-particle time dependent density
matrix for such a quantized system is calculated in the multiphoton resonant
approximation. The dependence of Rabi oscillations of Fermi-Dirac sea in
graphene on the time, momentum, and photon number at multiphoton
laser-excitation is analyzed.",1112.2905v1
2011-12-20,Phase of phonon-induced resistance oscillations in a high-mobility two-dimensional electron gas,"We report on experimental studies of magnetoresistance oscillations that
originate from the resonant interaction of two-dimensional electrons with
thermal transverse-acoustic phonons in very high-mobility GaAs/AlGaAs quantum
wells. We find that the oscillation maxima consistently occur when a frequency
of a phonon with twice the Fermi momentum exceeds an integer multiple of the
cyclotron frequency. This observation is in contrast to to all previous
experiments associating resistance maxima with magnetophonon resonance and its
harmonics. Our experimentally obtained resonant condition is in excellent
quantitative agreement with recent theoretical proposals.",1112.4766v1
2011-12-21,Remarks on the complex branch points in pi-N scattering amplitude and the multiple poles structure of resonances,"A simple heuristic argument to understand the existence of branch points in
the unphysical sheet for pi-N scattering amplitude is presented. It is based on
a hypothesis that the singularity structure of the pi-N scattering amplitude is
a smooth varying function of the pion mass. We find that, in general, multiple
poles structure of a resonance is a direct mathematical consequence when
additional Riemann surface is included in the study and the two-pole structure
found to correspond to the Roper resonance is a good example.",1112.5025v1
2011-12-21,Interference theory of metamaterial perfect absorbers,"The impedance matching in metamaterial perfect absorbers has been believed to
involve and rely on magnetic resonant response, with a direct evidence from the
anti-parallel directions of surface currents in the metal structures. Here we
present a different theoretical interpretation based on interferences, which
shows that the two layers of metal structure in metamaterial absorbers are
linked only by multiple reflections with negligible near-field interactions or
magnetic resonances. This is further supported by the out-of-phase surface
currents derived at the interfaces of resonator array and ground plane through
multiple reflections and superpositions. The theory developed here explains all
features observed in narrowband metamaterial absorbers and therefore provides a
profound understanding of the underlying physics.",1112.5168v1
2011-12-29,Reversible modulation and ultrafast dynamics of THz resonances in strongly photoexcited metamaterials,"We demonstrate an ultrafast reversible modulation of resonant terahertz (THz)
response in strongly photoexcited metamaterials. The transient
spectral-temporal response of the dipole transition ~1.6 THz exhibits a
distinct non-monotonic variation as a function of pump fluence. The transition
energy shift, strength, spectral width and density-dependent ultrafast
relaxation manifest a remarkable re-emergence of the resonances after initial
quenching. Our simulation, incorporating the first-order diffraction from the
photoinduced transient grating, reproduces the salient features, providing a
new avenue for designing nonlinear and frequency-agile THz modulators.",1112.6337v1
2012-02-03,High Mass Resonances at ATLAS,"A brief overview of searches for high mass resonances using a subset of data
collected by the ATLAS experiment during the 2011 LHC run is presented. Various
final states are explored including dilepton, diphoton, lepton with missing
transverse energy, dijet, photon with a jet, top anti-top pairs, and Z boson
pairs. No new resonance has been found and limits on several new physics models
are set.",1202.0727v1
2012-02-06,Nucleon Resonances with Hidden Charm in Coupled-Channel Models,"The model dependence of the predictions of nucleon resonances with hidden
charm is investigated. We consider several coupled-channel models which are
derived from relativistic quantum field theory by using (1) a unitary
transformation method, and (2) the three-dimensional reductions of
Bethe-Salpeter Equation. With the same vector meson exchange mechanism, we find
that all models give very narrow molecular-like nucleon resonances with hidden
charm in the mass range of 4.3 GeV $ < M_R < $ 4.5 GeV, in consistent with the
previous predictions.",1202.1036v1
2012-02-21,The spectrum of the scattering matrix near resonant energies in the semiclassical limit,"The object of study in this paper is the on-shell scattering matrix $S(E)$ of
the Schr\""odinger operator with the potential satisfying assumptions typical in
the theory of shape resonances. We study the spectrum of $S(E)$ in the
semiclassical limit when the energy parameter $E$ varies from
$E_\text{res}-\varepsilon$ to $E_\text{res}+\varepsilon$, where $E_\text{res}$
is a real part of a resonance, and $\varepsilon$ is sufficiently small. The
main result of our work describes the spectral flow of the scattering matrix
through a given point on the unit circle. This result is closely related to the
Breit-Wigner effect.",1202.4702v1
2012-02-21,Relativistic Resonant Relations between Massive Black Hole Binary and Extreme Mass Ratio Inspiral,"One component of a massive black hole binary (MBHB) might capture a small
third body, and then a hierarchical, inclined triple system would be formed.
With the post-Newtonian approximation including radiation reaction, we analyzed
the evolution of the triple initially with small eccentricities. We found that
an essentially new resonant relation could arise in the triple system. Here
relativistic effects are crucial. Relativistic resonances, including the new
one, stably work even for an outer MBHB of comparable masses, and significantly
change the orbit of the inner small body.",1202.4761v1
2012-02-27,Fast magnetization reversal of nanoclusters in resonator,"An effective method for ultrafast magnetization reversal of nanoclusters is
suggested. The method is based on coupling a nanocluster to a resonant electric
circuit. This coupling causes the appearance of a magnetic feedback field
acting on the cluster, which drastically shortens the magnetization reversal
time. The influence of the resonator properties, nanocluster parameters, and
external fields on the magnetization dynamics and reversal time is analyzed.
The magnetization reversal time can be made many orders shorter than the
natural relaxation time. The reversal is studied for both the cases of a single
nanocluster as well as for the system of many nanoclusters interacting through
dipole forces.",1202.5873v1
2012-02-29,Spin wave modes in magnetic nanodisks under in-plane magnetic field,"The size dependence of spin wave modes in a circular Permalloy (Py) nanodisk
under an in-plane magnetic field is systematically studied by using
micromagnetics simulations. We show that as the disk diameter is increased, the
resonance frequency of the backward mode deceases while that of the uniform
mode increases. The avoided crossing of resonance frequencies of the uniform
mode and the backward mode appears in the plot of the size dependence of
resonance frequencies and the backward mode turns into the so-called ""edge
mode"" for large nanodisks.",1202.6464v1
2012-03-01,Current-induced resonance in a ferromagnet - antiferromagnet junction,"We calculate the response of a ferromagnet - antiferromagnet junction to a
high-frequency magnetic field as a function of the spin-polarized current
through the junction. Conditions are choused under which the response is zero
in absence of such a current. It is shown that increasing in the current
density leads to proportional increase in the resonance frequency and resonant
absorption. A principal possibility is indicated of using ferromagnet -
antiferromagnet junction as a terahertz radiation detector.",1203.0114v1
2012-03-09,Magnetic field splitting of the spin-resonance in CeCoIn5,"Neutron scattering in strong magnetic fields is used to show the
spin-resonance in superconducting CeCoIn5 (Tc=2.3 K) is a doublet. The
underdamped resonance (\hbar \Gamma=0.069 \pm 0.019 meV) Zeeman splits into two
modes at E_{\pm}=\hbar \Omega_{0}\pm g\mu_{B} \mu_{0}H with g=0.96 \pm 0.05. A
linear extrapolation of the lower peak reaches zero energy at 11.2 \pm 0.5 T,
near the critical field for the incommensurate ""Q-phase"" indicating that the
Q-phase is a bose condensate of spin excitons.",1203.2189v1
2012-03-11,Magnetic damping of a carbon nanotube NEMS resonator,"A suspended, doubly clamped single wall carbon nanotube is characterized at
cryogenic temperatures. We observe specific switching effects in dc-current
spectroscopy of the embedded quantum dot. These have been identified previously
as nano-electromechanical self-excitation of the system, where positive
feedback from single electron tunneling drives mechanical motion. A magnetic
field suppresses this effect, by providing an additional damping mechanism.
This is modeled by eddy current damping, and confirmed by measuring the
resonance quality factor of the rf-driven nano-electromechanical resonator in
an increasing magnetic field.",1203.2319v2
2012-03-16,Nonlinear dynamics of beta induced Alfvén eigenmode driven by energetic particles,"Nonlinear saturation of beta induced Alfv\'en eigenmode, driven by slowing
down energetic particles via transit resonance, is investigated by the
nonlinear hybrid magnetohyrodynamic gyro-kinetic code (XHMGC). Saturation is
characterized by frequency chirping and symmetry breaking between co- and
counter-passing particles, which can be understood as the the evidence of
resonance-detuning. The scaling of the saturation amplitude with the growth
rate is also demonstrated to be consistent with radial resonance detuning due
to the radial non-uniformity and mode structure.",1203.3769v1
2012-03-01,Optimization of quasi-normal eigenvalues for Krein-Nudelman strings,"The paper is devoted to optimization of resonances for Krein strings with
total mass and statical moment constraints. The problem is to design for a
given $\alpha \in \R$ a string that has a resonance on the line $\alpha + \i
\R$ with a minimal possible modulus of the imaginary part. We find optimal
resonances and strings explicitly.",1203.4730v1
2012-03-21,Sharp tunneling peaks in a parametric oscillator: quantum resonances missing in the rotating wave approximation,"We describe a new mechanism of tunneling between period-two vibrational
states of a weakly nonlinear parametrically modulated oscillator. The tunneling
results from resonant transitions induced by the fast oscillating terms
conventionally disregarded in the rotating wave approximation (RWA). The
tunneling amplitude displays resonant peaks as a function of the modulation
frequency; near the maxima it is exponentially larger than the RWA tunneling
amplitude.",1203.4803v1
2012-06-01,Interference of stochastic resonances: Splitting of Kramers' rate,"We consider the escape of particles located in the middle well of a symmetric
triple well potential driven sinusoidally by two forces such that the potential
wells roll as in stochastic resonance and the height of the potential barrier
oscillates symmetrically about a mean as in resonant activation. It has been
shown that depending on their phase difference the application of these two
synchronized signals may lead to a splitting of time averaged Kramers' escape
rate and a preferential product distribution in a parallel chemical reaction in
the steady state.",1206.0093v1
2012-06-05,Representation of spectral functions and thermodynamics,"In this paper we study the question of effective field assignment to measured
or nonperturbatively calculated spectral functions. The straightforward
procedure is to approximate it by a sum of independent Breit-Wigner resonances,
and assign an independent field to each of these resonances. The problem with
this idea is that it introduces new conserved quantities in the free model (the
new particle numbers), therefore it changes the symmetry of the system. We
avoid this inconsistency by representing each quantum channel with a single
effective field, no matter how complicated the spectral function is.
Thermodynamical characterization of the system will be computed with this
representation method, and its relation to the independent resonance
approximation will be discussed.",1206.0865v1
2012-06-08,Geometric Stochastic Resonance,"A Brownian particle moving across a porous membrane subject to an oscillating
force exhibits stochastic resonance with properties which strongly depend on
the geometry of the confining cavities on the two sides of the membrane. Such a
manifestation of stochastic resonance requires neither energetic nor entropic
barriers, and can thus be regarded as a purely geometric effect. The magnitude
of this effect is sensitive to the geometry of both the cavities and the pores,
thus leading to distinctive optimal synchronization conditions.",1206.1723v1
2012-06-11,Dark Resonance,"We construct explicit models of particle dark matter where the attractive
force in the dark matter sector creates a narrow near-threshold resonance that
qualitatively changes the energy dependence of the annihilation cross section.
In these models, the resonant enhancement of the dark matter annihilation can
easily source the excess of energetic leptons observed by experiments on PAMELA
and FERMI satellites. The distinct feature of these models is that by
construction the enhancement of the annihilation cross section shuts off when
the dark matter velocity falls below the typical Milky Way values, thus
automatically satisfying constraints on dark matter annihilation imposed by the
CMB anisotropies and gamma ray constraints from satellite galaxies.",1206.2371v1
2012-06-27,Optimal Squeezing in Resonance Fluorescence via Atomic-State Purification,"Squeezing of atomic resonance fluorescence is shown to be optimized by a
properly designed environment, which can be realized by a quasi-resonant
cavity. Optimal squeezing is achieved if the atomic coherence is maximized,
corresponding to a pure atomic quantum state. The atomic-state purification is
achieved by the backaction of the cavity field on the atom, which increases the
atomic coherence and decreases the atomic excitation. For realistic cavities,
the coupling of the atom to the cavity field yields a purity of the atomic
state of more than 99%. The fragility of squeezing against dephasing is
substantially reduced in this scenario, which may be important for various
applications.",1206.6255v1
2012-07-03,Self-consistent calculations of the electric giant dipole resonances in light and heavy mass nuclei,"While bulk properties of stable nuclei are successfully reproduced by
mean-field theories employing effective interactions, the dependence of the
centroid energy of the electric giant dipole resonance on the nucleon number A
is not. This problem is cured by considering many-particle correlations beyond
mean-field theory, which we do within the ""Quasiparticle Time Blocking
Approximation"". The electric giant dipole resonances in $^{16}$O, $^{40}$Ca,
and $^{208}$Pb are calculated using two new Skyrme interactions.",1207.0664v1
2012-07-04,Coupled $\ell$-wave confinement-induced resonances in cylindrically symmetric waveguides,"A semi-analytical approach to atomic waveguide scattering for harmonic
confinement is developed taking into account all partial waves. As a
consequence $\ell$-wave confinement-induced resonances are formed being coupled
to each other due to the confinement. The corresponding resonance condition is
obtained analytically using the $K$-matrix formalism. Atomic scattering is
described by transition diagrams which depict all relevant processes the atoms
undergo during the collision. Our analytical results are compared to
corresponding numerical data and show very good agreement.",1207.0989v3
2012-07-17,Sensitivity of Double-Sided Split Ring Resonator Arrays to Fabrication Tolerances,"We present a study of the effects of fabrication tolerances on the
performance of a planar array of double-sided split-ring resonators, printed on
two sides of a dielectric substrate and fabricated using a printed circuit
board (PCB) milling machine. The array is simulated and measured in an X-band
waveguide, and the measured resonant frequency is found to be 6.3% higher than
the predicted one. The sensitivity of the frequency response to several
possible fabrication and measurement errors is investigated, and the dominant
effect identified and demonstrated experimentally and in simulation.",1207.4211v1
2012-08-01,CaF2 Whispering-Gallery-Mode Resonator Stabilized Narrow Linewidth Laser,"A fiber laser is stabilized using a Calcium Fluoride (CaF2)
whispering-gallery-mode resonator. It is set up using a semiconductor optical
amplifier as a gain medium. The resonator is critically coupled through prisms,
and used as a filtering element to suppress the laser linewidth. Using the
self-heterodyne beat technique the linewidth is determined to be 13 kHz. This
implies an enhancement factor of 10^3 with respect to the passive cavity
linewidth. The three-cornered hat method shows a stability of 10^(-11) after 10
\mu s.",1208.0244v1
2012-08-01,Dipole resonances and the nuclear Schiff moment,"The nuclear Schiff moment creates a mechanism of transfer of the violation of
parity and time-reversal invariance by weak interaction in nuclei into the
atomic electric dipole moment. We point out an additional contribution to the
Schiff moment generated by the mixing of single-particle states through the
low-lying nuclear dipole resonances. An estimate shows that this contribution
is by order of magnitude comparable to single-particle contributions and can be
enhanced if the low-lying resonance has collective nature.",1208.0324v1
2012-08-05,The resonance absorption probability function for neutron and multiplicative integral,"The analytical approximations for the moderating neutrons flux density like
Fermi spectra, widely used in reactor physics, involve the probability function
for moderating neutron to avoid the resonant absorption obtained using some
restrictive assumptions regarding the acceptable resonances width. By means of
multiplicative integral (Volterra integral) theory for a commutative algebra an
analytical expression for the probability function is obtained rigorously
without any restrictive assumptions.",1208.1019v1
2012-08-09,Dynamics of quasi-parabolic one-resonant biholomorphisms,"In this paper we study the dynamics of germs of quasi-parabolic one-resonant
biholomorphisms of $\C^{n+1}$ fixing the origin, namely, those germs whose
differential at the origin has one eigenvalue 1 and the others having a one
dimensional family of resonant relations. We define some invariants and give
conditions which ensure the existence of attracting domains for such maps.",1208.1875v2
2012-08-09,Plasmonic resonances at interfaces patterned by nanoparticle lattices,"We present theoretical studies of the nature of the collective plasmon
resonances of surfaces upon which ordered lattices of spherical metallic
particles have been deposited. The collective plasmon modes, excited by light
incident on the surface, are explored for both square and rectangular lattices
of particles. The particular resonances excited by an incident beam of light
depend on the frequency, polarization, and angles of incidence. We show that
one can create surfaces for which the polarization of the reflected light is
frequency dependent. The form of the polarization dependent spectra can be
tuned by choosing materials and the parameters of the nanoparticle array.",1208.1911v1
2012-08-13,Multichannel parametrization of πN scattering amplitudes and extraction of resonance parameters,"We present results of a new multichannel partial-wave analysis for \pi N
scattering in the c.m. energy range 1080 to 2100 MeV. This work explicitly
includes \eta N and K \Lambda channels and the single pion photoproduction
channel. Resonance parameters were extracted by fitting partial-wave amplitudes
from all considered channels using a multichannel parametrization that is
consistent with S-matrix unitarity. The resonance parameters so obtained are
compared to predictions of quark models.",1208.2710v2
2012-08-21,Finite element modeling of coupled optical microdisk resonators for displacement sensing,"We analyze normal mode splitting in a pair of vertically coupled microdisk
resonators. A full vectorial finite element model is used to find the eigen
frequencies of the symmetric and antisymmetric composite modes as a function of
coupling distance. We find that the coupled microdisks can compete with the
best Fabry-Perot resonators in displacement sensing. We also show how we
configured FreeFem++ for the sphere eigenvalue problem.",1208.4320v2
2012-08-22,Effect of microwave irradiation on parametric resonance in intrinsic Josephson junctions,"The effect of microwave irradiation on the phase dynamics of intrinsic
Josephson junctions in high temperature superconductors is investigated. We
demonstrate the influence of microwave's amplitude variation on the
current-voltage characteristics and on the time dependence (temporal
oscillations) of the electric charge in the superconducting layers. A
remarkable changing of the longitudinal plasma wavelength at parametric
resonance is shown. We demonstrate an effect of the microwave radiation on the
width of the parametric resonance region.",1208.4467v1
2012-08-27,Resonance-free Region in scattering by a strictly convex obstacle,"We prove the existence of a resonance free region in scattering by a strictly
convex obstacle with the Robin boundary condition. More precisely, we show that
the scattering resonances lie below a cubic curve which is the same as in the
case of the Neumann boundary condition. This generalizes earlier results on
cubic poles free regions obtained for the Dirichlet boundary condition.",1208.5511v2
2012-08-29,Resonant Clocking Circuits for Reversible Computation,"A mechanism for the reduction of dynamic energy dissipation in the computing
circuit is described. The resonant circuit with controlled switches conserves
the stored energy by recovering upto 90% of energy that would be otherwise lost
during logic state transitions. This energy-conserving approach preserves
thermodynamic entropy, ideally preventing heat generation in the system. This
approach is used in a proposed resonant clocking and logic application without
dynamic energy dissipation.",1208.5889v2
2012-09-07,Influence of the 6^1S_0-6^3P_1 Resonance on Continuous Lyman-alpha Generation in Mercury,"Continuous coherent radiation in the vacuum-ultraviolet at 122 nm
(Lyman-alpha) can be generated using sum-frequency mixing of three fundamental
laser beams in mercury vapour. One of the fundamental beams is at 254 nm
wavelength, which is close to the 6^1S_0-6^3P_1 resonance in mercury.
Experiments have been performed to investigate the effect of this one-photon
resonance on phasematching, absorption and the nonlinear yield. The efficiency
of continuous Lyman-alpha generation has been improved by a factor of 4.5.",1209.1519v1
2012-09-15,Planar Metamaterial with Toroidal Moment,"We observe toroidal response from a planar metamaterial comprised of
asymmetric split ring resonators (ASRRs). It is showed that a toroidal-molecule
can be constructed through rational arrangement of planar ASRRs as meta-atoms
via manipulating structural symmetry of the meta-atoms. Field maps clearly
indicate that the toroidal resonance paves new electromagnetic confinement
style in a subwavelength scale. Planar scheme of manipulating the coupling
among the ASRRs may stimulate research in optical region involving toroidal
multipoles. Toroidal geometry together with the Fano resonance made high-Q
response will have enormous potential applications in low-threshold lasing,
cavity quantum electrodynamics and nonlinear processing.",1209.3400v1
2012-10-01,Three-particle decays of light nuclei resonances,"We have studied the three-particle decay of 12C, 9Be and 6Be resonances.
These nuclei have been described as three-body systems by means of the complex
scaled hyperspherical adiabatic expansion method. The short-distance part of
the wave-function is responsible for the energies whereas the information
related to the observable decay properties is contained at large distances,
which must be computed accurately. As an illustration we show the results for
the angular distribution of 9Be and 6Be resonances.",1210.0319v1
2012-10-04,Quantum light generation on a silicon chip using waveguides and resonators,"Integrated optical devices may replace bulk crystal or fiber based assemblies
with a more compact and controllable photon pair and heralded single photon
source and generate quantum light at telecommunications wavelengths. Here, we
propose that a periodic waveguide consisting of a sequence of optical
resonators may outperform conventional waveguides or single resonators and
generate more than 1 Giga-pairs per second from a sub-millimeter-long
room-temperature silicon device, pumped with only about 10 milliwatts of
optical power. Furthermore, the spectral properties of such devices provide
novel opportunities of wavelength-division multiplexed chip-scale quantum light
sources.",1210.1586v1
2012-10-18,Few-Qubit Magnetic Resonance Quantum Information Processors: Simulating Chemistry and Physics,"We review recent progress made in quantum information processing (QIP) which
can be applied in the simulation of quantum systems and chemical phenomena. The
review is focused on quantum algorithms which are useful for quantum simulation
of chemistry and advances in nuclear magnetic resonance (NMR) and electron spin
resonance (ESR) QIP. Discussions also include a number of recent experiments
demonstrating the current capabilities of the NMR QIP for quantum simulation
and prospects for spin-based implementations of QIP.",1210.4994v1
2012-10-25,Electrical Control of Silicon Photonic Crystal Cavity by Graphene,"Efficient conversion of electrical signal to optical signal in nano-photonics
enables solid state integration of electronics and photonics. Combination of
graphene with photonic crystals is promising for electro-optic modulation. In
this paper, we demonstrate that by electrostatic gating a single layer of
graphene on top of a photonic crystal cavity, the cavity resonance can be
changed significantly. A ~2nm change in the cavity resonance linewidth and
almost 400% (6 dB) change in resonance reflectivity is observed. In addition,
our analysis shows that a graphene-photonic crystal device can potentially be
useful for a high speed, and low power absorptive and refractive modulator,
while maintaining a small physical footprint.",1210.6716v1
2012-10-29,Current resonances in graphene with time dependent potential barriers,"A method is derived to solve the massless Dirac-Weyl equation describing
electron transport in a mono-layer of graphene with a scalar potential barrier
U(x,t), homogeneous in the y-direction, of arbitrary x- and time dependence.
Resonant enhancement of both electron backscattering and currents, across and
along the barrier, is predicted when the modulation frequencies satisfy certain
resonance conditions. These conditions resemble those for Shapiro-steps of
driven Josephson junctions. Surprisingly, we find a non-zero y-component of the
current for carriers of zero momentum along the y-axis.",1210.7609v1
2012-10-30,Microwave assisted resonant domain wall nucleation in permalloy nanowires,"We have designed a system to study microwave assisted domain wall nucleation
in permalloy nanowires. We find a substantial decrease in the nucleation field
when microwave fields are applied, in comparison to pulse fields. A clear
resonance peak is observed in the frequency dependence of the nucleation field,
which coincides with the uniform mode ferromagnetic resonance frequency. Owing
to the well-defined nucleation process, the switching field distribution is
small in contrast to previous reports. Our results show that localized
microwave field provides an efficient tool for injecting domain walls into
magnetic nanowires.",1210.7875v1
2012-11-01,A one-dimensional spin-orbit interferometer,"We demonstrate that the combination of an external magnetic field and the
intrinsic spin-orbit interaction results in nonadiabatic precession of the
electron spin after transmission through a quantum point contact (QPC). We
suggest that this precession may be observed in a device consisting of two QPCs
placed in series. The pattern of resonant peaks in the transmission is strongly
influenced by the non-abelian phase resulting from this precession. Moreover, a
novel type of resonance which is associated with suppressed, rather than
enhanced, transmission emerges in the strongly nonadiabatic regime. The shift
in the resonant transmission peaks is dependent on the spin-orbit interaction
and therefore offers a novel way to directly measure these interactions in a
ballistic 1D system.",1211.0080v1
2012-11-30,Noise Properties of Coherent Perfect Absorbers and Critically-coupled Resonators,"The performance of a coherent perfect absorber (time-reversed laser) is
limited by quantum and thermal noise. At zero temperature, the quantum shot
noise dominates the signal for frequencies close to the resonance frequency,
and both vanish exactly at the resonance frequency. We compute the sensitivity
of the absorbing cavity as a background-free detector, limited by finite signal
or detector bandwidth.",1211.7147v1
2012-12-07,Complex masses of resonances and the Cornell potential,"Physical properties of the Cornell potential in the complex-mass scheme are
investigated. Two exact asymptotic solutions of relativistic wave equation for
the coulombic and linear components of the potential are used to derive the
resonance complex-mass formula. The centered masses and total widths of the
$\rho$-family resonances are calculated.",1212.1737v2
2012-12-18,A constructive method for computing generalized Manley--Rowe constants of motion,"The Manley--Rowe constants of motion (MRC) are conservation laws written out
for a dynamical system describing the time evolution of the amplitudes in
resonant triad. In this paper we extend the concept of MRC to resonance
clusters of any form yielding generalized Manley--Rowe constants (gMRC) and
give a constructive method how to compute them. We also give details of a
\emph{Mathematica} implementation of this method. While MRC provide
integrability of the underlying dynamical system, gMRC generally do not but may
be used for qualitative and numerical study of dynamical systems describing
generic resonance clusters.",1212.4295v1
2012-12-21,PT-symmetry with a system of three-level atoms,"We show that a vapor of multilevel atoms driven by far-off resonant laser
beams, with possibility of interference of two Raman resonances, is highly
efficient for creating parity-time (PT) symmetric profiles of the probe-field
refractive index, whose real part is symmetric and imaginary part is
anti-symmetric in space. The spatial modulation of the susceptibility is
achieved by proper combination of standing-wave strong control fields and of
Stark shifts induced by a far-off-resonance laser field. As particular examples
we explore a mixture of isotopes of Rubidium atoms and design a PT-symmetric
lattice and a parabolic refractive index with a linear imaginary part.",1212.5486v1
2012-12-26,Ultrastrong coupling in a scalable design for circuit QED with superconducting flux qubits,"We theoretically study a circuit quantum electrodynamics (QED) architecture
with superconducting flux qubits. The qubit is coupled to the transmission line
resonator by an ac current originating from the current mode of the resonator.
Ultrastrong coupling can be obtained by varying the capacitance between the
qubit and the resonator. We propose a scalable design where the two-qubit
coupling can be achieved.",1212.6181v3
2013-01-06,Coherent control of single photons in the cross resonator arrays via the dark state mechanism,"We study the single photon transfer in a hybrid system where the normal modes
of two coupled resonator arrays interact with two transition arms of a ?-type
atom localized in the intersectional resonator. It is found that, due to the
Fano-Feshbach effect based on the dark state of the ?-type atom, the photon
transfer in one array can be well controlled by the bound state of the photon
in the other array. This conceptual setup could be implemented in some
practical cavity QED system to realize a quantum switch for single photon.",1301.0987v1
2013-01-30,Multi-spectral near perfect metamaterial absorbers using spatially multiplexed plasmon resonance metal square structures,"Near perfect infrared light absorption at multi-spectral wavelengths has been
experimentally demonstrated by using multiplexed metal square plasmon resonance
structures. Optical power absorption over 95% has been observed in dual-band
metamaterial absorbers at two separate wavelengths and optical power absorption
over 92.5% has been observed in triple-band metamaterial absorbers at three
separate wavelengths. The peak absorption wavelengths are primarily determined
by the sizes of the metal squares in the multiplexed structures. Electrical
field distributions in the middle of the dielectric spacer layer were
calculated at the peak absorption wavelengths. It is shown that strong light
absorption corresponds to the local quadrupole plasmon resonance modes in the
metamaterial structures.",1301.7142v1
2013-02-01,Resonant state expansion applied to two-dimensional open optical systems,"The resonant state expansion (RSE), a rigorous perturbative method in
electrodynamics, is applied to two-dimensional open optical systems. The
analytically solvable homogeneous dielectric cylinder is used as unperturbed
system, and its Green's function is shown to contain a cut in the complex
frequency plane, which is included in the RSE basis. The complex
eigenfrequencies of modes are calculated using the RSE for a selection of
perturbations which mix unperturbed modes of different orbital momentum, such
as half-cylinder, thin-film and thin-wire perturbation, demonstrating the
accuracy and convergency of the method. The resonant states for the thin-wire
perturbation are shown to reproduce an approximative analytical solution.",1302.0245v1
2013-02-12,Existence and Construction of Resonances for Atoms Coupled to the Quantized Radiation Field,"For a nonrelativistic atom, which is minimally coupled to the quantized
radiation field, resonances emerging from excited atomic eigenstates are
constructed by an iteration scheme inspired by \cite{Pizzo2003} and
\cite{BachFrohlichPizzo2006}. This scheme successively removes an infrared cut
off in momentum space and yields a convergent algorithm enabling us to
calculate the resonance eigenvalues and eigenstates, to arbitrary order in the
feinstructure constant $\alpha \sim 1/137$, and is thus an alternative method
of proof of a similar result obtained in \cite{Sigal2010}.",1302.2829v1
2013-02-14,Model independent extraction of the pole and Breit-Wigner resonance parameters,"We show that a slightly modified Breit-Wigner formula can successfully
describe the total cross section even for the broad resonances, from light
rho(770) to the heavy Z boson. In addition to mass, width, and branching
fraction, we include another resonance parameter that turns out to be directly
related to the pole residue phase. The new formula has two mathematically
equivalent forms: one with the pole, and the other with the Breit-Wigner
parameters.",1302.3491v3
2013-02-18,Controlled coupling of photonic crystal cavities using photochromic tuning,"We present a method to control the resonant coupling interaction in a
coupled-cavity photonic crystal molecule by using a local and reversible
photochromic tuning technique. We demonstrate the ability to tune both a
two-cavity and a three-cavity photonic crystal molecule through the resonance
condition by selectively tuning the individual cavities. Using this technique,
we can quantitatively determine important parameters of the coupled-cavity
system such as the photon tunneling rate. This method can be scaled to photonic
crystal molecules with larger numbers of cavities, which provides a versatile
method for studying strong interactions in coupled resonator arrays.",1302.4322v1
2013-03-12,The symmetric 1:2 resonance,"This paper illustrates the application of Lie transform normal-form theory to
the construction of the 1:2 resonant normal form corresponding to a wide class
of natural Hamiltonian systems. We show how to compute the bifurcations of the
main periodic orbits in a potential with double reflection symmetries. The
stability analysis of the normal modes and of the periodic orbits in general
position allows us to get overall informations on the phase-space structure of
systems in which this resonance is dominating. As an example we apply these
results to a class of models useful as galactic potentials.",1303.2907v1
2013-03-15,A silicon electromechanical photodetector,"Opto-mechanical systems have enabled wide-band optical frequency conversion
and multi-channel all-optical radio frequency amplification. Realization of an
on-chip silicon communication platform is limited by photodetectors needed to
convert optical information to electrical signals for further signal
processing. In this paper we present a coupled silicon micro-resonator, which
converts near-IR optical intensity modulation at 174.2MHz and 1.198GHz into
motional electrical current. This device emulates a photodetector which detects
intensity modulation of continuous wave laser light in the
full-width-at-half-maximum bandwidth of the mechanical resonance. The resonant
principle of operation eliminates dark current challenges associated with
convetional photodetectors.",1303.3900v1
2013-03-26,Efficient Site-specific Low-energy Electron Production via Interatomic Coulombic Decay Following Resonant Auger Decay,"We identified interatomic Coulombic decay (ICD) channels in argon dimers
after spectator-type resonant Auger decay $2p^{-1}~3d \to 3p^{-2}3d, 4d$ in one
of the atoms, using momentum resolved electron-ion-ion coincidence. The results
illustrate that the resonant core excitation is a very efficient way of
producing slow electrons at a specific site, which may cause localized
radiation damage. We find also that ICD rate for $3p^{-2}4d$ is significantly
lower than that for $3p^{-2}3d$.",1303.6395v1
2013-04-03,Slow light enhanced correlated photon pair generation in photonic-crystal coupled-resonator optical waveguides,"We demonstrate the generation of quantum-correlated photon pairs from a Si
photonic-crystal coupled-resonator optical waveguide. A slow-light supermode
realized by the collective resonance of high-Q and small-mode-volume
photonic-crystal cavities successfully enhanced the efficiency of the
spontaneous four-wave mixing process. The generation rate of photon pairs was
improved by two orders of magnitude compared with that of a photonic-crystal
line defect waveguide without a slow-light effect.",1304.0843v1
2013-04-11,Graphene-coated holey metal films: tunable molecular sensing by surface plasmon resonance,"We report on the enhancement of surface plasmon resonances in a holey
bidimensional grating of subwavelength size, drilled in a gold thin film coated
by a graphene sheet. The enhancement originates from the coupling between
charge carriers in graphene and gold surface plasmons. The main plasmon
resonance peak is located around 1.5 microns. A lower constraint on the
gold-induced doping concentration of graphene is specified and the interest of
this architecture for molecular sensing is also highlighted.",1304.3291v2
2013-04-16,Resonant delocalization on the Bethe strip,"Recently, Aizenman and Warzel discovered a mechanism for the appearance of
absolutely continuous spectrum for random Schroedinger operators on the Bethe
lattice through rare resonances (resonant delocalization). We extend their
analysis to operators with matrix-valued random potentials drawn from ensembles
such as the Gaussian Orthogonal Ensemble. These operators can be viewed as
random operators on the Bethe strip, a graph (lattice) with loops.",1304.4461v3
2013-05-04,"Pion-Nucleus Elastic Scattering, DCX and Sub-Threshold Resonances","In the scattering of positive pions by nuclei the double-charge-exchange
(DCX) reaction creates the possibility of formation of pionic atom states in
the vicinity of the threshold of this reaction. These quasi stationary states
can manifest themselves as resonances in the elastic scattering cross section.
The strength and shape of these resonances is strongly affected by an
instability of the nucleus created in the DCX channel. It is shown that this
mechanism can explain oscillation structures in the excitation function
observed in scattering of low-energy positive pions from $^{12}\text{C}$.",1305.0952v1
2013-05-09,Experimental Observation of Localized Modes in a Dielectric Square Resonator,"We investigated the frequency spectra and field distributions of a dielectric
square resonator in a microwave experiment. Since such systems cannot be
treated analytically, the experimental studies of their properties are
indispensable. The momentum representation of the measured field distributions
shows that all resonant modes are localized on specific classical tori of the
square billiard. Based on these observations a semiclassical model was
developed. It shows excellent agreement with all but a single class of measured
field distributions that will be treated separately.",1305.2049v2
2013-05-20,Multichannel parametrization of $\bar K N$ scattering amplitudes and extraction of resonance parameters,"We present results of a new multichannel partial-wave analysis for $\bar K N$
scattering in the c.m.\ energy range 1480 to 2100 MeV. Resonance parameters
were extracted by fitting partial-wave amplitudes from all considered channels
using a multichannel parametrization that is consistent with $S$-matrix
unitarity. The resonance parameters are generally in good agreement with
predictions of the Koniuk-Isgur quark model.",1305.4575v2
2013-05-23,Composite or elementary? Probing the nature of the Higgs,"I discuss consequences of electroweak symmetry breaking by strong dynamics,
assuming the existence of a light composite scalar appearing as a
pseudo-Goldstone boson of some global symmetry of the new strongly interacting
sector. In such a scenario, the composite scalar has properties very similar to
the Standard Model Higgs, but the existence of additional resonances with
different spins is also expected. Properties and phenomenology of lightest
spin-1 resonances are considered in a simple general effective Lagrangian
description. The question whether the effects of spin-1 resonances can be
observed at the LHC, shedding light on the nature of the Higgs boson, is
addressed.",1305.5364v1
2013-05-23,Robust energy transfer mechanism and critically balanced turbulence via non-resonant triads in nonlinear wave systems,"A robust energy transfer mechanism is found in nonlinear wave systems, which
favours transfers towards modes interacting via non-resonant triads, applicable
in meteorology, nonlinear optics and plasma wave turbulence. Transfer
efficiency is maximal when the frequency mismatch of the non-resonant triad
balances the system's nonlinear frequency: at intermediate levels of
oscillation amplitudes an instability is triggered that explores unstable
manifolds of periodic orbits, so turbulent cascades are most efficient at
intermediate nonlinearity. Numerical simulations confirm analytical
predictions.",1305.5517v2
2013-05-24,Harmonic Generation in Multi-Resonant Plasma Films,"We investigate second and third harmonic generation in a slab of material
that displays plasma resonances at the pump and its harmonic frequencies.
Near-zero refractive indices and local field enhancement can deplete the pump
for kW/cm2 incident powers, without resorting to other resonant photonic
mechanisms. We show that low-threshold, highly-efficient nonlinear processes
are possible in the presence of losses and phase-mismatch in structures that
are 104 times shorter than typical KDP or LiNbO3 crystals, for relatively low
irradiance values.",1305.5866v1
2013-05-30,Single-top $t$-channel production with off-shell and non-resonant effects,"This letter details and discusses the next-to-leading order QCD corrections
to $t$-channel electro-weak $W^+ b j$ production, where finite top-width
effects are consistently taken into account. The computation is done within the
aMC@NLO framework and includes both resonant and non-resonant contributions as
well as interferences between the two. Results are presented for the LHC and
compared to those of the narrow-width approximation and effective theory
approaches.",1305.7088v1
2013-06-03,Nanoscopic interferometer model for spin resonance in current noise,"We study a model for the observed phenomenon of electron spin resonance (ESR)
at the Zeeman frequency as seen by a scanning tunneling microscope (STM) via
its current noise. The model for this ESR-STM phenomenon allows the STM current
to flow in two arms of a nanoscopic interferometer, one arm has direct
tunneling from the tip to the substrate while the second arm has tunneling
through two spin states. We evaluate analytically the noise spectrum for
non-polarized leads, as relevant to the experimental setup. We show that
spin-orbit interactions allow for an interference of two tunneling paths
resulting in a resonance effect.",1306.0363v1
2013-06-08,A Raman-induced Feshbach resonance in an effectively single-component Fermi gas,"Ultracold gases of interacting spin-orbit coupled fermions are predicted to
display exotic phenomena such as topological superfluidity and its associated
Majorana fermions. Here, we experimentally demonstrate a route to
strongly-interacting single-component atomic Fermi gases by combining an s-wave
Feshbach resonance (giving strong interactions) and spin-orbit coupling
(creating an effective p-wave channel). We identify the Feshbach resonance by
its associated atomic loss feature and show that, in agreement with our
single-channel scattering model, this feature is preserved and shifted as a
function of the spin-orbit coupling parameters.",1306.1965v1
2013-06-09,Breakdown of Kohn Theorem Near Feshbach Resonance,"We study the collective excitation frequencies of a harmonically trapped 85Rb
Bose-Einstein condensate (BEC) in the vicinity of a Feshbach resonance. To this
end, we solve the underlying Gross-Pitaevskii (GP) equation by using a Gaussian
variational approach and obtain the coupled set of ordinary differential
equations for the widths and the center of mass of the condensate. A
linearization shows that the dipole mode frequency decreases when the bias
magnetic field approaches the Feshbach resonance, so the Kohn theorem is
violated.",1306.1988v1
2013-06-26,Anisotropic LMN dielectronic resonances from ratios of magnetic-dipole lines,"Signatures of multi-keV LMN dielectronic resonances in highly-charged 3d^n
ions of tungsten were detected in the intensity ratios of extreme-ultraviolet
magnetic-dipole lines within ground configurations. The measurements were
performed with an electron beam ion trap at beam energies of about 6 keV.
Large-scale collisional-radiative modeling incorporating magnetic sublevels of
autoionizing levels showed the significance of anisotropy effects due to the
monodirectional propagation of the electron beam. The observation method allows
simultaneous resolved registration of dielectronic resonances from several
ions.",1306.6293v1
2013-06-26,Padé Approximants and Resonance Poles,"Based on the mathematically well defined Pad\'e Theory, a theoretically safe
new procedure for the extraction of the pole mass and width of a resonance is
proposed. In particular, thanks to the Montessus de Ballore theorem we are able
to unfold the Second Riemann Sheet of an amplitude to search for the position
of the resonant pole in the complex plane. The method is systematic and
provides a model-independent treatment of the prediction and the corresponding
errors of the approximation.",1306.6308v1
2013-07-05,An effective model of QCD thermodynamics,"A combined effective model reproducing the equation of state of hadronic
matter as obtained in recent lattice QCD simulations is presented. The model
reproduces basic physical characteristics encountered in dense hadronic matter
in the quark-gluon plasma (QGP) phase and the lower temperature hadron
resonance gas phase. The hadronic phase is described by means of an extended
Mott-Hagedorn resonance gas while the QGP phase is described by the extended
PNJL model. The dissociation of hadrons is obtained by including the state
dependent hadron resonance width.",1307.1732v1
2013-07-12,Fermi liquid theory of resonant spin pumping,"We study resonant all-electric adiabatic spin pumping through a quantum dot
with two nearby levels by using a Fermi liquid approach in the strongly
interacting regime, combined with a projective numerical renormalization group
(NRG) theory. Due to spin-orbit coupling, a strong spin pumping resonance
emerges at every charging transition, which allows for the transfer of a spin
$~ \hbar/2$ through the device in a single pumping cycle. Depending on the
precise geometry of the device, controlled pure spin pumping is also possible.",1307.3416v2
2013-07-22,Scattering for the Klein-Gordon equation with quadratic and variable coefficient cubic nonlinearities,"We study the 1D Klein-Gordon equation with variable coefficient cubic
nonlinearity. This problem exhibits a striking resonant interaction between the
spatial frequencies of the nonlinear coefficients and the temporal oscillations
of the solutions. In the case where the worst of this resonant behavior is
absent, we prove L-Infinity scattering as well as a certain kind of strong
smoothness for the solution at time-like infinity with the help of several new
normal-forms transformations. Some explicit examples are also given which
suggest qualitatively different behavior in the case where the strongest cubic
resonances are present.",1307.5882v2
2013-07-24,Quantum-Information Processing with Hybrid Spin-Photon Qubit Encoding,"We introduce a scheme to perform quantum-information processing that is based
on a hybrid spin-photon qubit encoding. The proposed qubits consist of
spin-ensembles coherently coupled to microwave photons in coplanar waveguide
resonators. The quantum gates are performed solely by shifting the resonance
frequencies of the resonators on a ns timescale. An additional cavity
containing a Cooper-pair box is exploited as an auxiliary degree of freedom to
implement two-qubit gates. The generality of the scheme allows its potential
implementation with a wide class of spin systems.",1307.6474v1
2013-07-28,Real Time Electrical Detection of Coherent Spin Oscillations,"We demonstrate that the bandwidth of pulsed electrically detected magnetic
resonance can be increased to at least 80 MHz using a radio
frequency-reflectometry detection scheme. Using this technique, we measure
coherent spin oscillations in real time during a resonant microwave pulse. We
find that the observed signal is in quantitative agreement with simulations
based on rate equations modeling the recombination dynamics of the spin system
under study. The increased bandwidth opens the way to electrically study faster
spin-dependent recombination processes, e.g., in direct semiconductors which so
far have almost exclusively been studied by optically detected magnetic
resonance.",1307.7413v1
2013-10-04,Resonant Excitation of Tilt Mode in Tidally Deformed Disks,"In a previous paper (Kato 2013b), we have shown that in deformed disks a pair
of trapped oscillation modes can be resonantly excited through couplings with
disk deformation. In this paper we examine in what cases tilts are excited on
tidally deformed disks by the above-mentioned wave-wave resonant process. The
results show that tilts can be excited in various evolutional stages of tidally
deformed disks, although the wave mode which becomes the pair to the tilt and
the mode of tidal waves contributing to the resonance change by change of disk
stages.",1310.1140v1
2013-10-07,Complex absorbing potential method for the perturbed Dirac operator,"The Complex Absorbing Potential (CAP) method is widely used to compute
resonances in Quantum Chemistry, both for nonrelativistic and relativistic
Hamiltonians. In the semiclassical limit $\hbar \to 0$ we consider resonances
near the real axis and we establish the CAP method rigorously for the perturbed
Dirac operator by proving that individual resonances are perturbed eigenvalues
of the nonselfadjoint CAP Hamiltonian, and vice versa. The proofs are based on
pseudodifferential operator theory and microlocal analysis.",1310.1872v1
2013-10-11,Impinging Jet Resonant Modes at Mach 1.5,"High speed impinging jets have been the focus of several studies owing to
their practical application and resonance dominated flow-field. The current
study focuses on the identification and visualization of the resonant modes at
certain critical impingement heights for a Mach 1.5 normally impinging jet.
These modes are associated with high amplitude, discrete peaks in the power
spectra and can be identified as having either axisymmetric or azimuthal modes.
Their visualization is accomplished through phase-locked Schlieren imaging and
fast-response pressure sensitive paint (PC-PSP) applied to the ground plane.",1310.3305v1
2013-10-14,Signatures of two-level defects in the temperature-dependent damping of nanomechanical silicon nitride resonators,"The damping rates of high quality factor nanomechanical resonators are well
beyond intrinsic limits. Here, we explore the underlying microscopic loss
mechanisms by investigating the temperature-dependent damping of the
fundamental and third harmonic transverse flexural mode of a doubly clamped
silicon nitride string. It exhibits characteristic maxima reminiscent of
two-level defects typical for amorphous materials. Coupling to those defects
relaxes the momentum selection rules, allowing energy transfer from discrete
long wavelength resonator modes to the high frequency phonon environment.",1310.3671v1
2013-10-18,Effective magnetic fields for photons in waveguide and coupled resonator lattices,"A method to realize effective magnetic fields for photons in square lattices
of coupled optical waveguides or resonators is suggested, which is inspired by
an optical analogue of photon-assisted tunneling of atom optics. It is shown
that an artificial magnetic field can be achieved by application of an index
gradient and periodic lumped phase shifts or modulation of the propagation
constants/resonances, without the need to modulate the coupling strength.",1310.5001v1
2013-11-02,Transformation optics with Fabry-Pérot resonances,"Transformation optics is a powerful tool to design various novel devices,
such as invisibility cloak. Fantastic effects from this technique are usually
accompanied with singular mappings, resulting in challenging implementations
and narrow bands of working frequencies. Here in this article, we find that
Fabry-P\'erot resonances can be used to design various transformation optical
devices that are not only easy to realize but also can work well for a set of
resonant frequencies (multiple frequencies). As an example, we fabricate a
prototype for a cylindrical concentrator for microwaves.",1311.0384v1
2013-11-04,The $Σ$(1385) photoproduciton from proton within a Regge-plus-resonance approach,"The interaction mechanism of the $\Sigma$(1385) photoproduction from proton
is investigated within a Regge-plus-resonance approach based on the
experimental data released by CLAS Collaboration recently. The t-channel and
u-channel contributions are responsible to the behaviors of the differential
cross sections at forward and backward angles, respectively. The contributions
from nucleon resonances including $N^*$ and $\Delta^*$, which are determined by
the predicted decay amplitudes in constituent quark model, are found small but
essential to reproduce the differential cross section especially the
contribution from $F_{35}$ state $\Delta(2000)$.",1311.0571v2
2013-11-04,Wireless energy transfer between anisotropic metamaterials shells,"The behavior of strongly coupled Radial Photonic Crystals shells is
investigated as a potential alternative to transfer electromagnetic energy
wirelessly. These sub-wavelength resonant microstructures, which are based on
anisotropic metamaterials, can produce efficient coupling phenomena due to
their high quality factor. A configuration of selected constitutive parameters
(permittivity and permeability) is analyzed in terms of its resonant
characteristics. The coupling to loss ratio between two coupled resonators is
calculated as a function of distance, the maximum (in excess of 300) is
obtained when the shells are separated by three times their radius. Under
practical conditions an 83% of maximum power transfer has been also estimated.",1311.0727v1
2013-11-11,Visualization of Rabi oscillations in a magnetic resonance,"A visualization scheme for dynamics of a qudit polarization vector in a
time-dependent magnetic field is presented by solving equations for a density
matrix in Hermitian basis. This is realized by means of mapping solution for
the polarization vector on the three-dimensional spherical curve (vector
hodograph).
  The obtained results obviously display the interference of precessional and
nutational effects on the polarization vector in a magnetic resonance. The
study can find the practical applications in a magnetic resonance and 3D
visualization of computational data.",1311.2537v2
2013-11-21,Stationary resonances of rapidly-rotating Kerr black holes,"The Klein-Gordon equation for a massive scalar field in the background of a
rapidly-rotating Kerr black hole is studied analytically. In particular, we
derive a simple formula for the stationary (marginally-stable) resonances of
the field in the black-hole spacetime. The analytically derived formula is
shown to agree with direct numerical computations of the resonances. Our
results provide an upper bound on the instability regime of rapidly-rotating
Kerr black holes to massive scalar perturbations.",1311.5298v1
2013-11-22,Recurrence in resonant transmission of one-dimensional array of delta potentials,"The resonant transmission of a moving particle which interacts with an
one-dimensional array of N delta-function potentials is investigated. A
suitable transfer matrix formulation is used to obtain the particle
transmission. We give the parameters for perfect tunnelling and the
transcendental equation for the quasi-bound state energies for N = 2, 3 and 4.
Conditions for perfect tunnelling and resonant transmission are discussed for
arrays with arbitrary N. A model to explain how the tunnelling energy filter
works in these systems is proposed here.",1311.5628v1
2013-11-26,Electrical tuning and switching of an optical frequency comb generated in aluminum nitride microring resonators,"Aluminum nitride has been shown to possess both strong Kerr nonlinearity and
electro-optic Pockels effect. By combining these two effects, here we
demonstrate on-chip reversible on/off switching of the optical frequency comb
generated by an aluminum nitride microring resonator. We optimize the design of
gating electrodes and the underneath resonator structure to effectively apply
electric field without increasing the optical loss. The switching of the comb
is monitored by measuring one of the frequency comb peaks while varying the
electric field. The controlled comb electro-optic response is investigated for
direct comparison with the transient thermal effect.",1311.6797v1
2013-11-27,Non-integer optical modes in a Möbius-ring resonator,"In-plane polarized light experiences a non-trivial topological evolution as
it propagates resonantly in a M\""obius ring resonator. The resultant geometric
phase varies continuously when changing the light ellipticity, which leads to
constructive interference for a non-integer number of wavelengths, and
therefore to the occurrence of an arbitrary fractional number of optical modes.
The geometric phase in M\""obius-ring resonators is topologically robust and
implies excellent intrinsic fault-tolerance.",1311.7158v2
2013-12-09,A Compressed Sensing Framework for Magnetic Resonance Fingerprinting,"Inspired by the recently proposed Magnetic Resonance Fingerprinting (MRF)
technique, we develop a principled compressed sensing framework for
quantitative MRI. The three key components are: a random pulse excitation
sequence following the MRF technique; a random EPI subsampling strategy and an
iterative projection algorithm that imposes consistency with the Bloch
equations. We show that theoretically, as long as the excitation sequence
possesses an appropriate form of persistent excitation, we are able to
accurately recover the proton density, T1, T2 and off-resonance maps
simultaneously from a limited number of samples. These results are further
supported through extensive simulations using a brain phantom.",1312.2465v2
2013-12-13,Extreme Harmonic Generation in Electrically Driven Spin Resonance,"We report the observation of multiple harmonic generation in electric dipole
spin resonance in an InAs nanowire double quantum dot. The harmonics display a
remarkable detuning dependence: near the interdot charge transition as many as
eight harmonics are observed, while at large detunings we only observe the
fundamental spin resonance condition. The detuning dependence indicates that
the observed harmonics may be due to Landau-Zener transition dynamics at
anticrossings in the energy level spectrum.",1312.3875v2
2013-12-17,Similariton-like Pulses in Synchronously Pumped Singly Resonant Optical Parametric Oscillators,"Similariton-like pulses are found to be formed in synchronously pumped singly
resonant optical parametric oscillators (OPO) by numerical simulation. The
nonlinear coupled-wave equations can be reduced to inhomogeneous nonlinear
Schr\""{o}dinger equation. The signal pulses with parabola-like temporal
intensity profile and linear chirp are presented in OPO. The similariton-like
pulses in OPO have many practical and potential applications.",1312.4651v2
2013-12-21,Probing the localization length of photo-generated charges in organic materials,"We report a new experimental method to measure the localization length of
photo-generated carriers in an organic donor-acceptor photovoltaic blend by
comparing their dielectric and electron spin-resonance susceptibilities which
are simultaneously measured by monitoring the resonance frequency of a
superconducting resonator. We show that at cryogenic temperatures excitons are
dissociated into long lived states, but that these are confined within a
separation of around $4\;{\rm nm}$. We determine the Debye and recombination
times, showing the coexistence of a fast electrical response corresponding to
delocalized motion, with glass-like recombination kinetics.",1312.6245v1
2013-12-27,Cooling a two-level emitter in photonic crystal environments,"We investigate the resonant cooling phenomena of a driven two-level radiator
embedded in a photonic crystal structure. We find that cooling occurs even at
laser-atom-frequency resonance. This happens due to the atomic dressed-states
coupling with different strengths resulting in population redistribution and
cooling. Furthermore, for off-resonant driving the two-level particle can be in
either ground or excited bare-state, respectively. This may help in engineering
of novel amplified optical devices as well as highly coherent light sources.",1312.7220v1
2014-01-05,Optical Rogue Waves in Whispering-Gallery-Mode Resonators,"We report a theoretical study showing that rogue waves can emerge in
whispering gallery mode resonators as the result of the chaotic interplay
between Kerr nonlinearity and anomalous group-velocity dispersion. The
nonlinear dynamics of the propagation of light in a whispering gallery-mode
resonator is investigated using the Lugiato-Lefever equation, and we evidence a
range of parameters where rare and extreme events associated with a
non-gaussian statistics of the field maxima are observed.",1401.0924v1
2014-01-05,A classical channel model for gravitational decoherence,"We show that, by treating the gravitational interaction between two
mechanical resonators as a classical measurement channel, a gravitational
decoherence model results that is equivalent to a model first proposed by
Diosi. The resulting decoherence model implies that the classically mediated
gravitational interaction between two gravitationally coupled resonators cannot
create entanglement. The gravitational decoherence rate ( and the complementary
heating rate) is of the order of the gravitationally induced normal mode
splitting of the two resonators.",1401.0946v1
2014-01-10,Feshbach resonances in ultracold gases,"In this chapter, we describe scattering resonance phenomena in general, and
focus on the mechanism of Feshbach resonances, for which a multi-channel
treatment is required. We derive the dependence of the scattering phase shift
on magnetic field and collision energy. From this, the scattering length and
effective range coefficient can be extracted, expressions which are
particularly useful for ultracold gases.",1401.2945v1
2014-01-15,Plasmon ruler with gold nanorod dimers: utilizing the second-order resonance,"The idea of utilizing the second-order plasmon resonance of the gold nanorod
{\pi}-dimers for plasmon rulers is introduced. We report on a qualitatively
different dependence of the plasmon resonance shift on the interparticle
distance for the first- and second-order longitudinal modes, extending the
working range of plasmon rulers up to the distance values of 400 nm.",1401.3671v1
2014-01-18,"Semitransparent One Dimensional Potential, A Green's Function Approach","We study the unstable harmonic oscillator and the unstable linear potential
in the presence of the point potential, which is the superposition of the Dirac
$\delta(x)$ and the derivative $\delta'(x)$. Using the \textit{physical}
boundary conditions for the Green's function we derive for both systems the
resonance poles and the resonance wave functions. The matching conditions for
the resonance wave functions coincide with those obtained by the self-adjoint
extensions of the point potentials and also by the modelling of the
$\delta'(x)$. We find that, with our definitions, the pure $b\delta'(x)$
barrier is semi-transparent \textit{independent} of the value of $b$.",1401.4588v2
2014-01-24,Restriction Bounds for the Free Resolvent and Resonances in Lossy Scattering,"We establish high energy $L^2$ estimates for the restriction of the free
Green's function to hypersurfaces in $\mathbb{R}^d$. As an application, we
estimate the size of a logarithmic resonance free region for scattering by
potentials of the form $V\otimes \delta_{\Gamma}$, where $\Gamma \subset
\mathbb{R}^d$ is a finite union of compact subsets of embedded hypersurfaces.
In odd dimensions we prove a resonance expansion for solutions to the wave
equation with such a potential.",1401.6243v1
2014-01-29,Optical Leaky-Wave Antenna Integrated in Ring Resonator,"A leaky-wave antenna at optical frequencies is designed and integrated with a
ring resonator at 1550 nm wavelength. The leaky wave is generated by using
periodic perturbations in the integrated dielectric waveguide that excite the
-1 spatial harmonic. The antenna consists of a dielectric waveguides with
semiconductor corrugations, and it is compatible with CMOS fabrication
technology. We show that integrating the leaky wave antenna in an optical ring
resonator that is fed by directional couplers, we can improve the electronic
control of the radiation through carrier injection into the semiconductor
corrugations.",1401.7609v1
2014-02-06,Effective degrees of freedom in QCD thermodynamics,"An effective model reproducing the equation of state of hadronic matter as
obtained in recent lattice QCD simulations and from hadron resonance gas data
is presented. The hadronic phase is described by means of an extended
Mott-Hagedorn resonance gas while the QGP phase is described by the extended
PNJL model. The dissociation of hadrons is obtained by including the state
dependent hadron resonance width. The model gives a quantitative estimate for
partial fractions of hadronic and partonic degrees of freedom above $T_c$.",1402.1509v1
2014-02-11,Attosecond time delay in the photoionization of endohedral atoms A@C$_{60}$: A new probe of confinement resonances,"The effects of confinement resonances on photoelectron group delay (Wigner
time delay) following ionization of an atom encapsulated inside a C$_{60}$ cage
have been studied theoretically using both relativistic and non-relativistic
random phase approximations. The results indicate clearly the resonant
character of the confinement oscillations in time delay of the $4d$ shell of
Xe@C$_{60}$ and present a most direct manifestation of Wigner time delay. These
oscillations were missed in a previous theoretical investigation of Ar@C$_{60}$
[PRL 111, 203003 (2013)]",1402.2348v1
2014-02-19,Quantum phenomena in a chirped parametric anharmonic oscillator,"The parametric ladder climbing (successive Landau-Zener-type transitions) and
the quantum saturation of the threshold for the classical parametric
autoresonance due to the zero point fluctuations at low temperatures are
discussed. The probability for capture into the chirped parametric resonance is
found by solving the Schrodinger equation in the energy basis and the
associated resonant phase space dynamics is illustrated via the Wigner
distribution. The numerical threshold for the efficient capture into the
resonance is compared with the classical and quantum theories in different
parameter regimes.",1402.4643v1
2014-02-19,Long-term analysis of numerical integrators for oscillatory Hamiltonian systems under minimal non-resonance conditions,"For trigonometric and modified trigonometric integrators applied to
oscillatory Hamiltonian differential equations with one or several constant
high frequencies, near-conservation of the total and oscillatory energies are
shown over time scales that cover arbitrary negative powers of the step size.
This requires non-resonance conditions between the step size and the
frequencies, but in contrast to previous results the results do not require any
non-resonance conditions among the frequencies. The proof uses modulated
Fourier expansions with appropriately modified frequencies.",1402.4755v2
2014-04-01,Stochastic resonance in the two-dimensional q-state clock models,"We numerically study stochastic resonance in the two-dimensional q-state
clock models from q = 2 to 7 under a weak oscillating magnetic field. As in the
mean-field case, we observe double resonance peaks, but the detailed response
strongly depends on the direction of the field modulation for q >= 5 where the
quasiliquid phase emerges. We explain this behavior in terms of free-energy
landscapes on the two-dimensional magnetization plane.",1404.0100v1
2014-04-13,Invariant sets and connecting orbits for nonlinear evolution equations at resonance,"We study the problem of existence of orbits connecting stationary points for
the nonlinear heat and strongly damped wave equations being at resonance at
infinity. The main difficulty lies in the fact that the problems may have no
solutions for general nonlinearity. To address this question we introduce
geometrical assumptions for the nonlinear term and use them to prove index
formulas expressing the Conley index of associated semiflows. We also prove
that the geometrical assumptions are generalizations of the well known
Landesman- Lazer and strong resonance conditions. Obtained index formulas are
used to derive criteria determining the existence of orbits connecting
stationary points.",1404.3428v2
2014-04-13,Stable radiating gap solitons and their resonant interactions with dispersive waves in systems with parametric pump,"We study the formation of gap solitons in the presence of parametric pump. It
is shown that parametric pump can stabilize stationary solitons continuously
emitting dispersive waves. The resonant interactions of the radiation and the
solitons are studied and it is shown that the solitons can be effectively
controlled by the radiation. In particular it is shown that the solitons can
collide or to get pinned to inhomogeneities due to the interactions mediated by
the resonant radiation.",1404.3432v1
2014-04-15,Finite time cooling in dispersively and dissipatively coupled optomechanics,"The cooling performance of an optomechanical system comprising both
dispersive and dissipative coupling is studied. We present a scheme to cool a
mechanical resonator to its ground state in finite time by employing a chirped
pulse. When the cavity damping strength increases, the phonon occupation of the
resonator will decrease. Moreover, the cooling behaviors of this dispersively
and dissipatively coupled system with different incident pulses, different
system coupling strengths are explored. Our scheme is feasible to cool the
resonator in a wide parameter region.",1404.3851v2
2014-04-20,"Resonant bands, Aomoto complex, and real 4-nets","The resonant band is a useful notion for the computation of the nontrivial
monodromy eigenspaces of the Milnor fiber of a real line arrangement. In this
article, we develop the resonant band description for the cohomology of the
Aomoto complex. As an application, we prove that real 4-nets do not exist.",1404.5014v3
2014-07-01,Multiphoton resonances for all-optical quantum logic with multiple cavities,"We develop a theory for the interaction of multi-level atoms with multi-mode
cavities yielding cavity-enhanced multi-photon resonances. The locations of the
resonances are predicted from the use of effective two- and three-level
Hamiltonians. As an application we show that quantum gates can be realised when
photonic qubits are encoded on the cavity modes in arrangements where ancilla
atoms transit the cavity. The fidelity of operations is increased by
conditional measurements on the atom and by the use of a selected, dual-rail,
Hilbert space. A universal set of gates is proposed, including the Fredkin gate
and iSWAP operation; the system seems promising for scalability.",1407.0239v1
2014-07-02,Fano resonance in the nonadiabatic pumped shot noise of a time-dependent potential well,"We use the Floquet scattering theory to study the correlation properties of
the nonadiabatic pumped dc current and heat flow through a time-dependent
potential well. Oscillator induced quasibound states of electrons can transit
to the Floquet states leading to resonant tunneling effect. Virtual electron
scattering processes can produce pumped heat flow, pumped shot noise and pumped
heat flow noise, with presence of time and spatial reversal symmetry. When one
of the Floquet levels matches the quasibound level there strikes a ""Fano""
resonance.",1407.0429v2
2014-07-07,Self-focused beams to couple light into a whispering-gallery mode resonator,"We propose an original method to couple light into a whispering-gallery mode
resonator. This method benefits from the mode selectivity and robustness of the
prism-coupling along with the single-mode propagation of the fiber taper. It
consists in a prism shaped crystal with a waveguide inscribed inside it. The
waveguide is self-inscribed in-situ by beam self-trapping to allow an optimum
coupling to a given resonator.",1407.1599v1
2014-07-11,Deformation effects in Giant Monopole Resonance,"The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from
spherical $^{144}$Sm to deformed $^{148-154}$Sm) is investigated within the
Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The
exact RPA and its separable version (SRPA) are used for spherical and deformed
nuclei, respectively. The quadrupole deformation is shown to yield two effects:
the GMR broadens and attains a two-peak structure due to the coupling with the
quadrupole giant resonance.",1407.3108v2
2014-07-16,Spectral behavior of localized plasmon resonances in the near- and far-field regimes. Comment on The spectral shift between near- and far-field resonances of optical nano-antennas,"In a recent paper by Menzel et al. (Opt. Exp. 22, 9971 (2014)), its authors
analyze the spectral red-shift effect of plasmonic resonances of metallic
nano-antennas between the far-field and near-field regimes. Here, we
demonstrate that their interpretation of this effect is done under the same
perspective as one recently reported in Langmuir 29, 6715 (2013); however, the
former is incomplete and needs some remarks and clarifications which require
additional relevant concepts and arguments of physical significance.",1407.4203v1
2014-07-16,Selective engineering of cavity resonance for frequency matching in optical parametric processes,"We propose to selectively engineer a single cavity resonance to achieve
frequency matching for optical parametric processes in high-Q microresonators.
For this purpose, we demonstrate an approach, selective mode splitting (SMS),
to precisely shift a targeted cavity resonance, while leaving other cavity
modes intact. We apply SMS to achieve efficient parametric generation via
four-wave mixing in high-Q silicon microresonators. The proposed approach is of
great potential for broad applications in integrated nonlinear photonics.",1407.4488v1
2014-07-31,Stochastic stability of Pollicott-Ruelle resonances,"Pollicott-Ruelle resonances for chaotic flows are the characteristic
frequencies of correlations. They are typically defined as eigenvalues of the
generator of the flow acting on specially designed functional spaces. We show
that these resonances can be computed as viscosity limits of eigenvalues of
second order elliptic operators. These eigenvalues are the characteristic
frequencies of correlations for a stochastically perturbed flow.",1407.8531v2
2014-08-06,Possible new resonance from $W_L W_L$-$hh$ interchannel coupling,"We propose and theoretically study a possible new resonance caused by strong
coupling between the Higgs-Higgs and the W_L W_L (Z_L Z_L) scattering channels,
without regard to the intensity of the elastic interaction in either channel at
low energy (that could be weak as in the Standard Model). We expose this
channel-coupling resonance from unitarity and dispersion relations encoded in
the Inverse Amplitude Method, applied to the Electroweak Chiral Lagrangian with
a scalar Higgs.",1408.1193v3
2014-08-08,Simulation of an axial vircator with a three-cavity resonator,"We simulated an axial vircator with a three-cavity resonator and expected
generation efficiency 6-7 percents. For adequate description of physical
processes taking place inside a vircator we used two independent PIC codes:
self-developed INPIC and free XOOPIC. Based on both the analysis of the
vircator proposed in [1] and consideration of the devices operating at
cathode-anode voltages under 450 kV we suggest 3 possible designs of a
three-cavity resonator such that enable one to produce High Power Microwave in
GW power range.",1408.1824v1
2014-08-11,Breit-Wigner phase is a fundamental property of a resonance,"In the course of devising a simple method for extraction of the S-matrix
poles from the data, an additional fundamental resonance property emerged. It
is a reaction invariant quantity, and since it is directly related to the
Breit-Wigner parameters, we call it the Breit-Wigner phase beta. We propose
that this beta is added in resonant data tables.",1408.2437v2
2014-08-18,Self-resonant Coil for Contactless Electrical Conductivity Measurement under Pulsed Ultra-high Magnetic Fields,"In this study, we develop experimental apparatus for contactless electrical
conductivity measurements under pulsed high magnetic fields over 100 T using a
self-resonant-type high-frequency circuit. The resonant power spectra were
numerically analyzed, and the conducted simulations showed that the apparatus
is optimal for electrical conductivity measurements of materials with high
electrical conductivity. The newly developed instruments were applied to a
high-temperature cuprate superconductor La$_{2-x}$Sr$_x$CuO$_4$ to show
conductivity changes in magnetic fields up to 102 T with a good signal-to-noise
ratio. The upper critical field was determined with high accuracy.",1408.3905v1
2014-08-19,"Hollow Core, Whispering Gallery Resonator Sensors","A review of hollow core whispering gallery resonators (WGRs)is given. After a
short introduction to the topic of whispering gallery resonators we provide a
description of whispering gallery modes in hollow or liquid core WGRs. Next,
whispering gallery mode (WGM) sensing mechanisms are outlined and some
fabrication methods for microbubbles, microcapillaries and other tubular WGM
devices are discussed. We then focus on the most common applications of hollow
core WGRs, namely refractive index and temperature sensing, gas sensing, force
sensing, biosensing, and lasing. The review highlights some of the key papers
in this field and gives the reader a general overview of the current
state-of-the-art.",1408.4338v1
2014-08-22,Optomechanical Ramsey Interferometry,"We adopt the Ramsey's method of separated oscillatory fields to study
coherences of the mechanical system in an optomechanical resonator. The high
resolution Ramsey fringes are observed in the emission optical field, when two
pulses separated in time are applied. We develop a theory to describe the
transient optomechanical behavior underlying the Ramsey fringes. We also
perform the experimental demonstration using a silica microresonator. The
method is versatile and can be adopted to different types of mechanical
resonators, electromechanical resonators.",1408.5305v1
2014-09-04,Resonant interaction of molecular vibrations and surface plasmon polaritons: The weak coupling regime,"Adjusting the free-electron concentration, the surface plasmon frequency of
the semiconductor ZnOGa is tuned into resonance with the molecular vibrations
of the n-alkane tetracontane. Closed molecular films deposited on the
semiconductor's surface in the monolayer regime generate distinct signatures in
total-attenuated-reflection spectra at the frequencies of the symmetric and
asymmetric stretching vibrations of the CH2 group. Their line shape undergoes
profound changes from absorptive to dispersive and even anti-resonance behavior
when moving along the surface- plasmon dispersion by the angel of incidence. We
demonstrate that this line shape diversity results from a phase-sensitive
perturbation of the surface-plasmon-polariton generation at the molecule/metal
interface.",1409.1421v1
2014-09-12,Two-electron resonances in quasi-one dimensional quantum dots with Gaussian confinement,"We consider a quasi one-dimensional quantum dot composed of two Coulombically
interacting electrons confined in a Gaussian trap. Apart from bound states, the
system exhibits resonances that are related to the autoionization process.
Employing the complex-coordinate rotation method, we determine the resonance
widths and energies and discuss their dependence on the longitudinal
confinement potential and the lateral radius of the quantum dot. The stability
properties of the system are discussed.",1409.3826v2
2014-09-19,Resonances in the Two-Centers Coulomb Systems,"We investigate the existence of resonances for two-centers Coulomb systems
with arbitrary charges in two dimensions, defining them in terms of generalised
complex eigenvalues of a non-selfadjoint deformation of the two-centers
Schr\""odinger operator. We construct the resolvent kernels of the operators and
prove that they can be extended analytically to the second Riemann sheet. The
resonances are then analysed by means of perturbation theory and numerical
methods.",1409.5580v3
2014-10-04,Phase Shift Analysis of the p14C Scattering at the Energy of the 2S1/2 Resonance,"The phase shift analysis for determination of the 2S1/2 resonance at 1.5 MeV
was carried out on the basis of the known experimental measurements of the
excitation functions of the p14C elastic scattering at four angles from 90 to
165 grad. and more than 100 energy values in the range from 600-800 to
2200-2400 keV. The obtained shape of the resonance 2S1/2 phase shift coincides
with the characteristics of the corresponding level of 15N in whole, and the
suggested potential acceptably describe this scattering phase shift.",1410.1044v1
2014-10-07,Modulating coherence resonance in non-excitable systems by time-delayed feedback,"We propose a paradigmatic model system, a subcritical Hopf normal form
subjected to noise and time-delayed feedback, to investigate the impact of time
delay on coherence resonance in non-excitable systems. We develop analytical
tools to estimate the stationary distribution and the time correlations in
nonlinear stochastic delay differential equations. These tools are applied to
our model to propose a novel quantity to measure coherence resonance induced by
a saddle-node bifurcation of periodic orbits.",1410.1686v1
2014-10-08,Single microparticles mass measurement using an AFM cantilever resonator,"In this work is presented a microbalance for single microparticle sensing
based on resonating AFM cantilever. The variation of the resonator
eigenfrequency is related to the particle mass positioned at the free apex of
the cantilever. An all-digital phase locked loop (PLL) control system is
developed to detect the variations in cantilever eigenfrequency. Two particle
populations of different materials are used in the experimental test,
demonstrating a mass sensitivity of 15 Hz/pg in ambient conditions. Thereby it
is validated the possibility of developing an inexpensive, portable and
sensitive microbalance for point-mass sensing.",1410.1953v1
2014-10-09,Integrated high quality factor lithium niobate microdisk resonators,"Lithium Niobate (LN) is an important nonlinear optical material. Here we
demonstrate LN microdisk resonators that feature optical quality factor ~
100,000, realized using robust and scalable fabrication techniques, that
operate over a wide wavelength range spanning visible and near infrared. Using
our resonators, and leveraging LN's large second order optical nonlinearity, we
demonstrate on-chip second harmonic generation with a conversion efficiency of
0.109 W-1.",1410.2625v1
2014-10-21,Pollicott-Ruelle resonances for open systems,"We define Pollicott-Ruelle resonances for geodesic flows on noncompact
asymptotically hyperbolic negatively curved manifolds, as well as for more
general open hyperbolic systems related to Axiom A flows. These resonances are
the poles of the meromorphic continuation of the resolvent of the generator of
the flow and they describe decay of classical correlations. As an application,
we show that the Ruelle zeta function extends meromorphically to the entire
complex plane.",1410.5516v2
2014-10-21,Relation of E1 pygmy and toroidal resonances,"A possible relation of the low-lying E1 (pygmy resonance) and toroidal
strengths is analyzed by using Skyrme-RPA results for the strength functions,
transition densities and current fields in $^{208}$Pb. It is shown that the
irrotational pygmy motion can appear as a local manifestation of the collective
vortical toroidal dipole resonance (TDR) at the nuclear surface. The RPA
results are compared to unperturbed (1ph) ones.",1410.5634v1
2014-11-10,"Bands, resonances, edge singularities and excitons in core level spectroscopy investigated within the dynamical mean field theory","Using a recently developed impurity solver we exemplify how dynamical mean
field theory captures band excitations, resonances, edge singularities and
excitons in core level x-ray absorption (XAS) and core level photo electron
spectroscopy (cPES) on metals, correlated metals and Mott insulators. Comparing
XAS at different values of the core-valence interaction shows how the
quasiparticle peak in the absence of core-valence interactions evolves into a
resonance of similar shape, but different origin. Whereas XAS is rather
insensitive to the metal insulator transition, cPES can be used, due to
nonlocal screening, to measure the amount of local charge fluctuation.",1411.2340v1
2014-11-11,Giant non-equilibrium vacuum friction: Role of singular evanescent wave resonances in moving media,"We recently reported on the existence of a singular resonance in moving media
which arises due to perfect amplitude and phase balance of evanescent waves. We
show here that the non-equilibrium vacuum friction (lateral Casimir-Lifshitz
force) between moving plates separated by a finite gap is fundamentally
dominated by this resonance. Our result is robust to losses and dispersion as
well as polarization mixing which occurs in the relativistic limit.",1411.2737v1
2014-11-12,Neutrino-pair bremsstrahlung from nucleon-$α$ versus nucleon-nucleon scattering,"We study the impact of the nucleon-$\alpha$ P-wave resonances on
neutrino-pair bremsstrahlung. Because of the non-central spin-orbit
interaction, these resonances lead to an enhanced contribution to the nucleon
spin structure factor for temperatures $T \lesssim 4$ MeV. If the
$\alpha$-particle fraction is significant and the temperature is in this range,
this contribution is competitive with neutron-neutron bremsstrahlung. This may
be relevant for neutrino production in core-collapse supernovae or other dense
astrophysical environments. Similar enhancements are expected for resonant
non-central nucleon-nucleus interactions.",1411.3266v1
2014-11-13,Determining Compositeness of Hadronic Resonances: the $Λ(1405)$ Radiative Decay and the $a_{0} (980)$-$f_{0} (980)$ Mixing,"Recently the concept of compositeness has been developed so as to distinguish
whether interested hadrons are hadronic molecules or not. Here, in terms of
compositeness, we investigate $\bar{K} N$ molecular structure of the $\Lambda
(1405)$ resonance with the $\Lambda (1405)$ radiative decay and $K \bar{K}$
molecular structure of the $a_{0} (980)$ and $f_{0} (980)$ resonances with the
$a_{0} (980)$-$f_{0} (980)$ mixing.",1411.3414v1
2014-11-17,Nonstationary photonic jet from dielectric microsphere,"A photonic jet commonly denotes the specific spatially localized region in
the near-field forward scattering of a light wave at a dielectric micron-sized
particle. We present the detailed calculations of the transient response of an
airborne silica microsphere illuminated by a femtosecond laser pulse. The
spatial area constituting the photonic jet is theoretically investigated and
the temporal dynamics of jet dimensions as well as of jet peak intensity is
analyzed. The role of morphology-dependent resonances in jet formation is
highlighted. The evolution scenario of a nonstationary photonic jet generally
consists of the non-resonant and resonant temporal phases. In every phase, the
photonic jet can change its spatial form and intensity.",1411.4870v1
2014-11-21,"Fuzzy Adaptive Resonance Theory, Diffusion Maps and their applications to Clustering and Biclustering","In this paper, we describe an algorithm FARDiff (Fuzzy Adaptive Resonance
Dif- fusion) which combines Diffusion Maps and Fuzzy Adaptive Resonance Theory
to do clustering on high dimensional data. We describe some applications of
this method and some problems for future research.",1411.5737v5
2014-11-22,A local trace formula for Anosov flows (with an appendix by Frédéric Naud),"We prove a local trace formula for Anosov flows. It relates Pollicott--Ruelle
resonances to the periods of closed orbits. As an application, we show that the
counting function for resonances in a sufficiently wide strip cannot have a
sublinear growth. In particular, for any Anosov flow there exist strips with
infinitely many resonances.",1411.6177v2
2014-11-26,Terahertz Harmonic Generation in Graphene,"We show that charge carrier transport in graphene exhibit sharp resonances in
the presence of spatially and temporarily modulated scattering. Resonances
occur when the period of an applied a-c field corresponds to the time taken by
quasi-ballistic carriers to drift over a spatial scattering period, provided
the latter is shorter than the distance taken by carriers to emit an optic
phonon. We show that such system can be achieved with interdigitated gates
energized with an a-c bias on graphene layers. Gate separation and fields to
achieve ballistic transport would result in resonances in the terahertz range,
with the generation of higher harmonics characterized by large Q-factors, which
are tunable with gate spacing.",1411.7075v1
2014-12-03,The photoresponse of a two-dimensional electron gas at the second harmonic of the cyclotron resonance,"Terahertz spectroscopy experiments at magnetic fields and low temperatures
were carried out on samples of different gate shapes processed on a high
electron mobility GaAs/AlGaAs heterostructure. For a given radiation frequency,
multiple magnetoplasmon resonances were observed with a dispersion relation
described within a local approximation of the magnetoconductivity tensor. The
second harmonic of the cyclotron resonance was observed and its appearance was
interpreted as resulting from a high frequency, inhomogeneous electromagnetic
field on the border of a two-dimensional electron gas with a metallic gate
and/or an ohmic contact.",1412.1371v2
2014-12-12,Resonant magneto-optic rotation for magnetometry using autonomous frequency stabilization,"The operation of a high sensitive atomic magnetometer using resonant
elliptically polarized light is demonstrated. The experimental geometry allows
autonomous frequency stabilization of the laser, thereby offers compact
operation of the overall device. The magnetometry is based on measurement of
the zero magnetic field resonance in degenerate two level system using
polarimetric detection and has a preliminary sensitivity of <10 pT/Hz1/2 @ 1
Hz.",1412.3968v1
2014-12-12,Optical bistability in a one-dimensional photonic crystal resonator using a reverse-biased pn-junction,"Optical bistability provides a simple way to control light with light. We
demonstrate low-power thermo-optical bistability caused by the Joule heating
mechanism in a one-dimensional photonic crystal (PC) nanobeam resonator with a
moderate quality factor (Q ~ 8900) with an embedded reverse-biased pn-junction.
We show that the photocurrent induced by the linear absorption in this compact
resonator considerably reduces the threshold optical power. The proposed
approach substantially relaxes the requirements on the input optical power for
achieving optical bistability and provides a reliable way to stabilize the
bistable features of the device.",1412.4162v1
2014-12-22,Accelerated nanoscale magnetic resonance imaging through phase multiplexing,"We report a method for accelerated nanoscale nuclear magnetic resonance
imaging by detecting several signals in parallel. Our technique relies on phase
multiplexing, where the signals from different nuclear spin ensembles are
encoded in the phase of an ultrasensitive magnetic detector. We demonstrate
this technique by simultaneously acquiring statistically polarized spin signals
from two different nuclear species (1H, 19F) and from up to six spatial
locations in a nanowire test sample using a magnetic resonance force
microscope. We obtain one-dimensional imaging resolution better than 5 nm, and
subnanometer positional accuracy.",1412.6914v2
2015-01-07,Two-photon lasing by a superconducting qubit,"We study the response of a magnetic-field-driven superconducting qubit
strongly coupled to a superconducting coplanar waveguide resonator. We observed
a strong amplification/damping of a probing signal at different resonance
points corresponding to a one and two-photon emission/absorption. The sign of
the detuning between the qubit frequency and the probe determines whether
amplification or damping is observed. The larger blue detuned driving leads to
two-photon lasing while the larger red detuning cools the resonator. Our
experimental results are in good agreement with the theoretical model of qubit
lasing and cooling at the Rabi frequency.",1501.01543v1
2015-01-09,Gate controlled resonant widths in double-bend waveguides: Bound states in the continuum,"We consider quantum transmission through double-bend $\Pi$- and $Z$-shaped
waveguides controlled by the finger gate potential. Using the effective
non-Hermitian Hamiltonian approach we explain the resonances in transmission.
We show a difference in transmission in the short waveguides that is the result
of different chirality in $Z$ and $\Pi$ waveguides. We show that the potential
selectively affects the resonant widths resulting in the occurrence of bound
states in the continuum.",1501.02037v1
2015-01-23,Time-bin entangled photon pair generation from Si micro-ring resonator,"We demonstrate time-bin entanglement generation in telecom wavelength using a
7 {\mu}m radius Si micro-ring resonator pumped by a continuous wave laser. The
resonator structure can enhance spontaneous four wave mixing, leading to a
photon pair generation rate of about 90-100 Hz with a laser pump power of as
low as -3.92 dBm (0.41 mW). We succeed in observing time-bin entanglement with
the visibility over 92%. Moreover, wavelength-tunability of the entangled
photon pair is demonstrated by changing the operation temperature.",1501.05687v1
2015-01-28,Optical resonators based on Bloch surface waves,"A few recent works suggest the possibility of controlling light propagation
at the interface of periodic multilayers supporting Bloch surface waves (BSWs),
but optical resonators based on BSWs are yet to demonstrate. Here we discuss
the feasibility of exploiting guided BSWs in a ring resonator configuration. In
particular, we investigate the main issues related to the design of these
structures, and we discuss about their limitations in terms of quality factors
and dimensions. We believe these results might be useful for the development of
a complete BSW-based platform for application ranging from optical sensing to
the study of the light-matter interaction in micro and nano structures.",1501.07025v1
2015-01-30,Resonance index and singular mu-invariant,"With the essential spectrum of a self-adjoint operator given a relatively
trace class perturbation one can associate an integer-valued invariant which
admits different descriptions as the singular spectral shift function, total
resonance index, and singular $\mu$-invariant. In this paper we give a direct
proof of the equality of the total resonance index and singular $\mu$-invariant
assuming only the limiting absorption principle. The proof is based on an
application of the argument principle to the poles and zeros of the analytic
continuation of the scattering matrix considered as a function of the coupling
parameter.",1501.07673v2
2015-02-05,Beam Position Monitor Electronics Upgrade for Fermilab Switchyard,"The beam position monitor (BPM) system for Fermilab Switchyard (SY) provides
the position, intensity and integrated intensity of the 53.10348 MHz RF bunched
resonant extracted beam from the Main Injector over 4 seconds of spill. The
total beam intensity varies from 1x10^11 to 1x10^13 protons. The spill is
measured by stripline beam postion monitors and resonant circuit. The BPMs have
an external resonant circuit tuned to 53.10348 MHz.
  The corresponding voltage signal out of the BPM has been estimated to be
between -110 dBm and -80 dBm.",1502.01745v1
2015-02-17,Direct Observation of Ferromagnetic State in Gold Nanorods Probed using Electron Spin Resonance Spectroscopy,"X-band electron spin resonance (ESR) spectroscopy has been performed for gold
nanorods (AuNRs) of four different sizes covered with a diamagnetic stabilizing
component, cetyltrimethylammmonium bromide. The ESR spectra show ferromagnetic
features such as hysteresis and resonance field shift, depending on the size of
the AuNRs. In addition, the ferromagnetic transition is indicated by an abrupt
change in the spectra of the two smallest AuNRs studied. A large g-value in the
paramagnetic region suggests that the ferromagnetism in the AuNRs originates
from strong spin-orbit interaction.",1502.04934v1
2015-03-01,Resonant excitation and photon entanglement from semiconductor quantum dots,"In this chapter we review the use of semiconductor quantum dots as sources of
quantum light. Principally, we focus on resonant two-photon excitation, which
is a method that allows for on-demand generation of photon pairs. We explore
the advantages of resonant excitation and present a number of measurements that
were made in this excitation regime. In particular, we cover the following
topics: photon statistics, coherent manipulation of the ground-excited state
superposition, and generation of time-bin entangled photon pairs.",1503.00352v1
2015-03-07,Quantum State Synthesis of Superconducting Resonators,"We present a theoretical analysis of different methods to synthesize
entangled states of two superconducting resonators. These methods use
experimentally demonstrated interactions of resonators with artificial atoms,
and offer efficient routes to generate nonclassical states. We analyze the
theoretical structure of these algorithms and their average performance for
arbitrary states and for deterministically preparing NOON states. Using a new
state synthesis algorithm, we show that NOON states can be prepared in a time
linear in the desired photon number and without any state-selective
interactions.",1503.02157v1
2015-03-09,Enhanced electromechanical coupling of a nanomechanical resonator to coupled superconducting cavities,"We investigate the electromechanical coupling between a nanomechanical
resonator and two parametrically coupled superconducting coplanar waveguide
cavities that are driven by a two-mode squeezed microwave source. We show that,
with the selective coupling of the resonator to the cavity Bogoliubov modes,
the radiation-pressure type coupling can be greatly enhanced by several orders
of magnitude, enabling the single photon strong coupling to be reached. This
allows the investigation of a number of interesting phenomena such as photon
blockade effects and the generation of nonclassical quantum states with
electromechanical systems.",1503.02393v2
2015-03-12,Chirp spectroscopy applied to the characterization of Ferromagnetic Resonance in Magnetic Tunnel Junctions,"Magnetic Tunnel Junction devices find use in several applications based on
the exploitation of the Spin-Transfer Torque phenomenon. The Ferromagnetic
Resonance curve is a key characteristic of any Magnetic Tunnel Junctions. It is
usually characterized both experimentally and numerically by performing a lot
of measurements of the magnetic response to a sinusoidal field or current. Here
we propose the use of a chirp signal as excitation signal to reconstruct the
Ferromagnetic resonance curve with a single measurement/simulation. A
micromagnetic comparison of the proposed method with the traditional one is
shown.",1503.03719v1
2015-03-12,Scalar Resonances in Axially Symmetric Spacetimes,"We study properties of resonant solutions to the scalar wave equation in
several axially symmetric spacetimes. We prove that non-axial resonant modes do
not exist neither in the Lanczos dust cylinder, the $(2+1)$ extreme BTZ
spacetime nor in a class of simple rotating wormhole solutions. Moreover, we
find unstable solutions to the wave equation in the Lanczos dust cylinder and
in the $r^2 <0$ region of the extreme $(2+1)$ BTZ spacetime, two solutions that
possess closed timelike curves. Similarities with previous results obtained for
the Kerr spacetime are explored.",1503.03755v1
2015-03-13,Nonlocal resonances in weak turbulence of gravity-capillary waves,"We report a laboratory investigation of weak turbulence of water surface
waves in the gravity-capillary crossover. By using time-space resolved
profilometry and a bicoherence analysis, we observe that the nonlinear
processes involve 3-wave resonant interactions. By studying the solutions of
the resonance conditions we show that the nonlinear interaction is dominantly
1D and involves collinear wave vectors. Furthermore taking into account the
spectral widening due to weak nonlinearity explains that nonlocal interactions
are possible between a gravity wave and high frequency capillary ones. We
observe also that nonlinear 3-wave coupling is possible among gravity waves and
we raise the question of the relevance of this mechanism for oceanic waves.",1503.04110v1
2015-03-17,Nonlocal description of sound propagation through an array of Helmholtz resonators,"A generalized macroscopic nonlocal theory of sound propagation in
rigid-framed porous media saturated with a viscothermal fluid has been recently
proposed, which takes into account both temporal and spatial dispersion. Here,
we consider applying this theory capable to describe resonance effects, to the
case of sound propagation through an array of Helmholtz resonators whose
unusual metamaterial properties such as negative bulk moduli, have been
experimentally demonstrated. Three different calculations are performed,
validating the results of the nonlocal theory, relating to the
frequency-dependent Bloch wavenumber and bulk modulus of the first normal mode,
for 1D propagation in 2D or 3D periodic structures.",1503.04920v1
2015-03-17,Multi-photon quantum communication in quantum networks,"We propose and analyze a multiphoton-state coherent transport protocol in a
coupled-resonator quantum network. A multiphoton swap gate between two
antipodes can be achieved with neither external modulation nor coupling
strength engineering. Moreover, we extend this result to a coupled-resonator
chain of arbitrary length with different coupling strengths. Effects of
decoherence via quantum nondemolition interaction are studied with sources
including vacuum quantum fluctuation and bath thermal excitations when the bath
is in the thermal equilibrium state. These observations are helpful to
understand the decoherence effects on quantum communication in quantum
coupled-resonator systems.",1503.04924v1
2015-03-18,Nucleon-nucleon resonances at intermediate energies using a complex energy formalism,"We apply our method of complex scaling, valid for a general class of
potentials, in a search for nucleon-nucleon S-matrix poles up to 2 GeV
laboratory kinetic energy. We find that the realistic potentials JISP16,
constructed from inverse scattering, and chiral field theory potentials N$^3$LO
and N$^2$LO$_{opt}$ support resonances in energy regions well above their fit
regions. In some cases these resonances have widths that are narrow when
compared with the real part of the S-matrix pole.",1503.05277v1
2015-03-27,Spin superradiance by magnetic nanomolecules and nanoclusters,"Spin dynamics of assemblies of magnetic nanomolecules and nanoclusters can be
made coherent by inserting the sample into a coil of a resonant electric
circuit. Coherence is organized through the arising feedback magnetic field of
the coil. The coupling of a magnetic sample with a resonant circuit induces
fast spin relaxation and coherent spin radiation, that is, superradiance. We
consider spin dynamics described by a realistic Hamiltonian, typical of
magnetic nanomolecules and nanoclusters. The role of magnetic anisotropy is
studied. A special attention is paid to geometric effects related to the mutual
orientation of the magnetic sample and resonator coil.",1503.08036v1
2015-04-14,Periodic impact motions at resonance of a particle bouncing on spheres and cylinders,"We investigate the existence of periodic trajectories of a particle, subject
to a central force, which can hit a sphere, or a cylinder. We will provide also
a Landesman-Lazer type of condition in the case of a nonlinearity satisfying a
double resonance condition. Afterwards, we will show how such a result can be
adapted to obtain a new result for the impact oscillator at double resonance.",1504.03457v1
2015-04-21,Microwave Emission from Hybridized States in a Semiconductor Charge Qubit,"We explore the microwave radiation emitted from a biased double quantum dot
due to the inelastic tunneling of single charges. Radiation is detected over a
broad range of detuning configurations between the dot energy levels with
pronounced maxima occurring in resonance with a capacitively coupled
transmission line resonator. The power emitted for forward and reverse resonant
detuning is found to be in good agreement with a rate equation model, which
considers the hybridization of the individual dot charge states.",1504.05497v2
2015-04-30,Synthetic gauge fields for light beams in optical resonators,"A method to realize artificial magnetic fields for light waves trapped in
passive optical cavities with anamorphic optical elements is theoretically
proposed. In particular, when a homogeneous magnetic field is realized, a
highly-degenerate Landau level structure for the frequency spectrum of the
transverse resonator modes is obtained, corresponding to a cyclotron motion of
the optical cavity field. This can be probed by transient excitation of the
passive optical resonator.",1504.08162v1
2015-05-01,Ising incommensurate spin resonance of CeCoIn$_{5}$: a dynamical precursor of the Q-phase,"It is shown by detailed inelastic neutron scattering experiments that the
gapped collective magnetic excitation of the unconventional superconductor
CeCoIn$_{5}$, the spin resonance mode, is incommensurate and that the
corresponding fluctuations are of Ising nature. The incommensurate peak
position of these fluctuations corresponds to the propagation vector of the
adjacent field induced static magnetic ordered phase, the so-called Q-phase.
Furthermore, the direction of the magnetic moment fluctuations is also the
direction of the ordered magnetic moments of the Q-phase. Hence the resonance
mode and the Q-phase share the same symmetry and this strongly supports a
scenario where the static order is realized by a condensation of the magnetic
excitation.",1505.00206v1
2015-05-04,Universal high-momentum asymptote and thermodynamic relations in a spinless Fermi gas with a resonant $p$-wave interaction,"We investigate universal relations in a spinless Fermi gas near a $p$-wave
Feshbach resonance. We show that the momentum distribution $n_{\vec{k}}$ has an
asymptote proportional to $k^{-2}$ with the proportionality constant--the
$p$-wave contact-- scaling with the number of closed-channel molecules. We
prove the adiabatic sweep theorem for a $p$-wave resonance which reveals the
physical meaning of the $p$-wave contact in thermodynamics. In contrast to the
unitary Fermi gas in which Tan's contact is universal, the $p$-wave contact
depends on the short-range details of the interaction.",1505.00622v1
2015-05-05,Superconducting metamaterials and qubits,"Superconducting thin-film metamaterial resonators can provide a dense
microwave mode spectrum with potential applications in quantum information
science. We report on the fabrication and low-temperature measurement of
metamaterial transmission-line resonators patterned from Al thin films. We also
describe multiple approaches for numerical simulations of the microwave
properties of these structures, along with comparisons with the measured
transmission spectra. The ability to predict the mode spectrum based on the
chip layout provides a path towards future designs integrating metamaterial
resonators with superconducting qubits.",1505.01015v1
2015-05-06,Multiple quasi-phase matched resonant radiations induced by modulation instability in dispersion oscillating fibers,"The propagation of a continuous wave in the average anomalous dispersion
region of a dispersion oscillating fiber is investigated numerically and
experimentally. We demonstrate that the train of solitons arising from
modulation instability is strongly affected by the periodic variations of the
fiber dispersion. This leads to the emission of multiple resonant radiations
located on both sides of the spectrum. Numerical simulations confirm the
experimental results and the position of the resonant radiations is well
predicted by means of perturbation theory.",1505.01256v1
2015-05-19,Asymptotic Behaviour of Resonance Eigenvalues of the Schrödinger operator with a Matrix Potential,"We will discuss the asymptotic behaviour of the eigenvalues of
Schr\""{o}dinger operator with a matrix potential defined by Neumann boundary
condition in $L_2^m(F)$, where $F$ is $d$-dimensional rectangle and the
potential is a $m \times m$ matrix with $m\geq 2$, $d\geq 2$ , when the
eigenvalues belong to the resonance domain, roughly speaking they lie near
planes of diffraction.
  \textbf{Keywords:} Schr\""{o}dinger operator, Neumann condition, Resonance
eigenvalue, Perturbation theory.
  \textbf{AMS Subject Classifications:} 47F05, 35P15",1505.05037v1
2015-06-01,Logical operations with single x-ray photons via dynamically-controlled nuclear resonances,"The implementation of logical operations on polarization-encoded x-rays via
resonant light-nucleus interactions is theoretically investigated. We show that
by means of resonant scattering off nuclei and fast rotations of the nuclear
hyperfine magnetic field to control the polarization of the output photon,
single-qubit logical gates can be simulated. A second control qubit may be
employed to trigger the magnetic field rotation, thus allowing several
implementation choices for a controlled NOT gate for x-ray photons.",1506.00517v1
2015-06-03,Coupled mode approach to square gradient Bragg reflection resonances in corrugated dielectric waveguides,"We demonstrate the appearance of unexpected reflection resonances in
corrugated dielectric waveguides. These are due to the curvature of the
boundary. The effect is as strong as the ordinary Bragg resonances, and reduces
the transmission through our waveguide by 20%. It is thus of high relevance for
the design of optimized waveguiding structures. We validate our analytical
predictions based on coupled mode theory by a comparison to numerical
simulations.",1506.01206v2
2015-06-05,Molecular predissociation resonances at an energy-level crossing,"We study the resonances of a two-by-two semiclassical system of one
dimensional Schr\""odinger operators, near an energy where the two potentials
intersect transversally, one of them being bonding, and the other one
anti-bonding. Under an ellipticity condition on the interaction, we obtain
optimal estimates on the location and on the widths of these resonances.",1506.01785v2
2015-06-09,Resonant tunneling through protected quantum dots at phosphorene edges,"We theoretically investigate phosphorene zigzag nanorribons as a platform for
constriction engineering. In the presence of a constriction at the upper edge,
quantum confinement of edge protected states reveals resonant tunnelling
Breit-Wigner transmission peaks, if the upper edge is uncoupled to the lower
edge. Coupling between edges in thin constrictions gives rise to Fano-like and
anti-resonances in the transmission spectrum of the system.",1506.03093v2
2015-06-11,Resonant dynamics and the instability of anti-de Sitter spacetime,"We consider spherically symmetric Einstein-massless-scalar field equations
with negative cosmological constant in five dimensions and analyze evolution of
small perturbations of anti-de Sitter spacetime using the recently proposed
resonant approximation. We show that for typical initial data the solution of
the resonant system develops an oscillatory singularity in finite time. This
result hints at a possible route to establishing instability of AdS under
arbitrarily small perturbations.",1506.03519v1
2015-06-11,Plasmon resonance with finite frequencies: a validation of the quasi-static approximation for diametrically small inclusions,"We study resonance for the Helmholz equation with a finite frequency in a
plasmonic material of negative dielectric constant in two and three dimensions.
We show that the quasi-static approximation is valid for diametrically small
inclusions. In fact, we quantitatively prove that if the diameter of a
inclusion is small compared to the loss parameter, then resonance occurs
exactly at eigenvalues of the Neumann-Poincar\'e operator associated with the
inclusion.",1506.03566v1
2015-06-16,Resonances and unitarity in composite Higgs models,"The scattering of longitudinally polarized W bosons in extensions of the
Standard Model with anomalous Higgs couplings to the gauge sector and higher
order $O(p^4)$ operators is considered. The modified couplings should be
thought as the low energy remnants of some new dynamics involving the
electroweak symmetry breaking sector. By imposing unitarity and causality
constraints on $W_LW_L$ scattering amplitudes we relate the possible values of
the effective couplings to the presence of new resonances above 300 GeV. We
investigate the properties of these new resonances and their experimental
detectability.",1506.04974v1
2015-06-18,Dispersive read-out of ferromagnetic resonance for strongly coupled magnons and microwave photons,"We demonstrate the dispersive measurement of ferromagnetic resonance in a
yttrium iron garnet sphere embedded within a microwave cavity. The reduction in
the longitudinal magnetization at resonance is measured as a frequency shift in
the cavity mode coupled to the sphere. This measurement is a result of the
intrinsic non-linearity in magnetization dynamics, indicating a promising route
towards experiments in magnon cavity quantum electro-dynamics.",1506.05631v1
2015-06-18,Highly accurate calculation of the resonances in the Stark effect in hydrogen,"We obtained accurate resonances for the Stark effect in hydrogen by means of
three independent methods. Two of them are based on complex rotation of the
coordinates and diagonalization of the Hamiltonian matrix (CRLM and CRCH). The
other one is based on the Riccati equations for the logarithmic derivatives of
factors of the wavefunction (RPM). The latter approach enabled us to obtain the
most accurate results and extremely sharp resonances.",1506.05797v1
2015-06-19,Coherent manipulation of a Majorana qubit by a mechanical resonator,"We propose a hybrid system composed of a Majorana qubit and a nanomechanical
resonator, implemented by a spin-orbit-coupled superconducting nanowire, using
a set of static and oscillating ferromagnetic gates. The ferromagnetic gates
induce Majorana bound states in the nanowire, which hybridize and constitute a
Majorana qubit. Due to the oscillation of one of these gates, the Majorana
qubit can be coherently rotated. By tuning the gate voltage to modulate the
local spin-orbit coupling, it is possible to reach the resonance of the
qubit-oscillator system for relatively strong couplings.",1506.05879v2
2015-07-09,Modification by pion exchange of near threshold resonance line shape in open heavy flavor channel,"The effect of the pion exchange on the line shape of near threshold
bottomoniumlike resonances decaying into an $S$ wave pair of $B^{(*)}$ mesons
is considered. It is pointed out that this effect, parametrically enhanced by
the heavy meson mass, can be of a practical significance in determining the
parameters of the bottomoniumlike resonances such as the known $Z_b(10610)$ and
$Z_b(10650)$ states.",1507.02639v1
2015-07-16,Antiferromagentic resonance detected by DC voltages in MnF$_2$/Pt bilayers,"We performed coplanar waveguide-based broadband ferromagnetic resonance
experiments on the antiferromagnetic insulator MnF$_2$, while simultaneously
recording the DC voltage arising in a thin platinum film deposited onto the
MnF$_2$. The antiferromagnetic resonance is clearly reflected in both the
transmission through the waveguide as well as the DC voltage in the Pt strip.
The DC voltage remains largely unaffected by field reversal and thus presumably
stems from microwave rectification and/or heating effects. However, we identify
a small magnetic field orientation dependent contribution, compatible with
antiferromagnetic spin pumping theory.",1507.04490v1
2015-07-22,Ultrafast electrical control of a resonantly driven single photon source,"We demonstrate generation of a pulsed stream of electrically triggered single
photons in resonance fluorescence, by applying high frequency electrical pulses
to a single quantum dot in a p-i-n diode under resonant laser excitation.
Single photon emission was verifed, with the probability of multiple photon
emission reduced to 2.8%. We show that despite the presence of charge noise in
the emission spectrum of the dot, resonant excitation acts as a filter to
generate narrow bandwidth photons.",1507.06169v1
2015-07-08,Parametric resonance and particle stochastic interactions with a periodic medium,"A non-markovian stochastic model shows the emergence of structures in the
medium, a self-organization characterized by a relationship between particle's
energy, driven frequency $\omega$ and a frequency of interaction with the
medium $\nu$. The interaction determines its mass and this fine tuning results
in an effective force given by $F_L=\hbar \omega^2 n(\lambda)/ c$, similar to
the interaction force between photons and atoms. Condition for the
particle-medium resonance is determined, with relevance to detect dark matter
axion-like particles and the parametric resonance as a pop-up mechanism to turn
fields into particles.",1507.07810v1
2015-08-11,Bipartite correlations in quantum resonance states,"We discuss a diagonal representation of a reduced density matrix determined
within the framework of the complex scaling method. We also discuss a possible
measure of bipartite correlations in quantum resonance states. As an example,
we consider a one-dimensional system of two bosons with a contact interaction
subjected to an open potential well. The correlation properties of the
lowest-energy resonance state of the system are explored over a wide range of
the inter-boson interaction strength, including the Tonks-Girardeau regime.",1508.02698v5
2015-08-28,"Rydberg blockade, Förster resonances, and quantum state measurements with different atomic species","We calculate interspecies Rydberg-Rydberg interaction strengths for the heavy
alkalis Rb and Cs. The presence of strong F\""orster resonances makes
interspecies coupling a promising approach for long range entanglement
generation. We also provide an overview of the strongest F\""orster resonances
for Rb-Rb and Cs-Cs using different principal quantum numbers for the two
atoms. We show how interspecies coupling can be used for high fidelity quantum
non demolition state measurements with low crosstalk in qubit arrays.",1508.07111v2
2015-09-13,Resonances for 1D half-line periodic operators: I. Generic case,"The present paper addresses questions on resonances for a $1$D
Schr\""{o}dinger operator with truncated periodic potential. Precisely, we
consider the half-line operator $H^{\mathbb N}=-\Delta +V$ and $H^{\mathbb N}_L
= -\Delta + V 1_{[0,L]}$ acting on $\ell^{2}(\mathbb N)$ with Dirichlet
boundary condition at $0$ with $L \in \mathbb N$. We describe the resonances of
$H^{\mathbb N}_{L}$ near the boundary of the essential spectrum of $H^{\mathbb
N}$ as $L \rightarrow +\infty$ in the generic case.",1509.03788v1
2015-09-17,Polariton resonances for ultra-strong coupling cavity optomechanics in GaAs/AlAs multiple quantum wells,"Polariton-mediated light-sound interaction is investigated through resonant
Brillouin experiments in GaAs/AlAs multiple-quantum wells. Photoelastic
coupling enhancement at exciton-polariton resonance reaches 105 at 30 K as
compared to a typical bulk solid room temperature transparency value. When
applied to GaAs based cavity optomechanical nanodevices, this result opens the
path to huge displacement sensitivities and to novel ultrastrong-coupling
cavity phenomena with optomechanical couplings g0 in the range of 100 THz.",1509.05152v1
2015-10-16,A sharp lower bound for a resonance-counting function in even dimensions,"This paper proves sharp lower bounds on a resonance counting function for
obstacle scattering in even-dimensional Euclidean space without a need for
trapping assumptions. Similar lower bounds are proved for some other compactly
supported perturbations of the Laplacian on even-dimensional Euclidean space,
for example, for the Laplacian for certain metric perturbations. The proof uses
a Poisson formula for resonances, complementary to one proved by Zworski in
even dimensions.",1510.04952v1
2015-10-19,Deformation-induced splitting of the monopole giant resonance in 24Mg,"The strong deformation splitting of the isoscalar giant monopole resonance
(ISGMR), recently observed in ($\alpha,\alpha'$) reaction in prolate $^{24}$Mg,
is analyzed in the framework of the Skyrme quasiparticle
random-phase-approximation (QRPA) approach with the Skyrme forces SkM*, SVbas
and SkP$^{\delta}$. The calculations with these forces give close results and
confirm that the low-energy E0-peak is caused by the deformation-induced
coupling of ISGMR with the K=0 branch of the isoscalar giant quadrupole
resonance.",1510.05499v1
2015-10-21,Temporal Behavior of Rabi Oscillation in Nanomechanical QED System with a Nonlinear Resonator,"In nanomechanical QED system, consisting of a charge qubit and a nonlinear
nanomechanical resonator, we study the temporal behavior of Rabi oscillation in
the nonlinear Jaynes-Cummings model. Using microscopic master equation
approach, we solve time evolution of the density operator describing this
model. Also, the probability of excited state of charge qubit is calculated.
These analytic calculations show how nonlinearity parameter and decay rates of
two different excited states of the qubit-resonator system affect
time-oscillating and decaying of Rabi oscillation.",1510.06159v2
2015-10-22,Anomalous longitudinal relaxation of nuclear spins in CaF$_2$,"We consider the effect of non-secular resonances for interacting nuclear
spins in solids which were predicted theoretically to exist in the presence of
strong static and strong radio-frequency magnetic fields. These resonances
imply corrections to the standard secular approximation for the nuclear
spin-spin interaction in solids, which, in turn, should lead to an anomalous
longitudinal relaxation in nuclear magnetic resonance experiments. In this
article, we investigate the feasibility of the experimental observation of this
anomalous longitudinal relaxation in calcium fluoride (CaF$_2$) and conclude
that such an observation is realistic.",1510.06589v1
2015-10-23,Power--bandwidth limitations of an optical resonance,"We present shape-independent upper limits to the power--bandwidth product for
a single resonance in an optical scatterer, with the bound depending only on
the material susceptibility. We show that quasistatic metallic scatterers can
nearly reach the limits, and we apply our approach to the problem of designing
$N$ independent, subwavelength scatterers to achieve flat, broadband response
even if they individually exhibit narrow resonant peaks.",1510.06902v1
2015-10-23,A random dynamical systems perspective on stochastic resonance,"We study stochastic resonance in an over-damped approximation of the
stochastic Duffing oscillator from a random dynamical systems point of view. We
analyse this problem in the general framework of random dynamical systems with
a nonautonomous forcing. We prove the existence of a unique global attracting
random periodic orbit and a stationary periodic measure. We use the stationary
periodic measure to define an indicator for the stochastic resonance.",1510.06973v1
2015-10-28,Resonant frequencies of the hydrodynamic vortex,"We study the sound perturbation of the hydrodynamic vortex geometry and
present an exact expression for the resonant frequencies (quasispectrum) of
this geometry. Exact solution for the radial part of the covariant Klein-Gordon
equation in this spacetime is obtained, and is given in terms of the double
confluent Heun functions. We found that the resonant frequencies are complex
number.",1510.08298v2
2015-10-29,Narrow Zero-Field Tunneling Resonance in Triclinic Mn$_{12}$ Acetate Ribbons,"We report synthesis, structural characterization, and magnetic measurements
of amorphous Mn$_{12}$-acetate ribbons with a triclinic short-range crystal
order not previously seen in experiment. The ribbons exhibit the same structure
of Mn$_{12}$ molecules and the same positions of tunneling resonances on the
magnetic field as a conventional tetragonal Mn$_{12}$-acetate crystal. However,
the width of the zero-field resonance is by at least one order of magnitude
smaller, indicating very small inhomoge- neous broadening due to dipolar and
nuclear fields. Possible origins of this effect are discussed.",1510.08894v1
2015-11-03,Telegraph frequency noise in electromechanical resonators,"We demonstrate experimentally the possibility of revealing fluctuations in
the eigenfrequency of a resonator when the frequency noise is of the telegraph
type. Using a resonantly driven micromechanical resonator, we show that the
time-averaged vibration amplitude spectrum exhibits two peaks. They merge with
an increasing rate of frequency switching and the spectrum displays an analog
of motional narrowing. We also show that the moments of the complex amplitude
depend strongly on the frequency noise characteristics. This dependence remains
valid even when strong thermal or detector noise is present.",1511.00893v1
2015-11-24,Complex Masses of Resonances in the Potential Approach,"Quarkonium resonances in the complex-mass scale are studied. Relativistic
quark potential model is used to describe the quark-antiquark system. The
complex-mass formula is obtained from two exact asymptotic solutions for the
QCD motivated potential with the distance-dependent value of the strong
coupling in QCD. The centered masses and total widths of some meson resonances
are calculated. A possible origin of the ``dark matter'' and the ``Missing
Mass''is discussed.",1511.07816v1
2016-01-06,Automatic Wavelength Tuning of Series-Coupled Vernier Racetrack Resonators on SOI,"Using in-resonator photoconductive heaters to both sense and control the
intra-cavity light intensity of microring resonators, automatic tuning of a
silicon-on-insulator two-ring Vernier filter is demonstrated across the entire
C-band.",1601.01022v1
2016-01-11,The breaking of the $SU(2)_L\times U(1)_Y$ symmetry: The 750 GeV resonance at the LHC and perturbative unitarity,"If the di-photon excess at 750 GeV hinted by the 2015 data at the LHC is
explained in terms of a scalar resonance participating in the breaking of the
electro-weak symmetry, this resonance must be accompanied by other scalar
states for perturbative unitarity in vector boson scattering to be preserved.
The simplest set-up consistent with perturbative unitarity and with the data of
the di-photon excess is the Georgi-Machacek model.",1601.02447v3
2016-01-21,Diphoton excess in phenomenological spin-2 resonance scenarios,"We provide a possible explanation of a 750 GeV diphoton excess recently
reported by both the ATLAS and CMS collaborations in the context of
phenomenological spin-2 resonance scenarios, where the independent effective
couplings of the resonance with gluons, quarks and photons are considered. We
find a parameter region where the excess can be accounted for without
conflicting with dijet constraints. We also show that the kinematical
distributions might help to determine the couplings to gluons and quarks.",1601.05729v2
2016-01-23,Nonlinear magnetization dynamics of antiferromagnetic spin resonance induced by intense terahertz magnetic field,"We report on the nonlinear magnetization dynamics of a HoFeO3 crystal induced
by a strong terahertz magnetic field resonantly enhanced with a split ring
resonator and measured with magneto-optical Kerr effect microscopy. The
terahertz magnetic field induces a large change (~40%) in the spontaneous
magnetization. The frequency of the antiferromagnetic resonance decreases in
proportion to the square of the magnetization change. A modified
Landau-Lifshitz-Gilbert equation with a phenomenological nonlinear damping term
quantitatively reproduced the nonlinear dynamics.",1601.06213v1
2016-02-02,Magnetization Dynamics of Topological Defects and the Spin Solid in Kagome Artificial Spin Ice,"We report broadband spin-wave spectroscopy on kagome artificial spin ice
(ASI) made of large arrays of interconnected Ni$_{80}$Fe$_{20}$ nanobars.
Spectra taken in saturated and disordered states exhibit a series of resonances
with characteristic magnetic field dependencies. Making use of micromagnetic
simulations, we identify resonances that reflect the spin-solid-state and
monopole-antimonopole pairs on Dirac strings. The latter resonances allow for
the generation of highly-charged vertices in ASIs via microwave assisted
switching. Our findings open further perspectives for fundamental studies on
ASIs and their usage in reprogrammable magnonics.",1602.00918v1
2016-02-02,Optical resonance shifts in the fluorescence of thermal and cold atomic gases,"We show that the resonance shifts in the fluorescence of a cold gas of
rubidium atoms substantially differ from those of thermal atomic ensembles that
obey the standard continuous medium electrodynamics. The analysis is based on
large-scale microscopic numerical simulations and experimental measurements of
the resonance shifts in a steady-state response in light propagation.",1602.01037v4
2016-02-10,Optical humidity sensor based on a liquid whispering-gallery mode resonator,"We experimentally demonstrate the use of a novel liquid state,
whispering-gallery-mode optical resonator as a highly sensitive humidity
sensor. The optical resonator used consists of a droplet made of glycerol, a
transparent liquid that enables high optical quality factor, doped with
rhodamine 6G, which acts as fluorescent emitter. As glycerol is highly
hygroscopic, the refractive index and radius of the droplet change with ambient
humidity. This produces a shift on the whispering gallery modes wavelengths,
which modulates the emission of rhodamine 6G. This easily-made device has an
unpreceded sensitivity of 10-3 per relative humidity percent.",1602.03322v1
2016-02-10,"Toroidal resonance: relation to pygmy mode, vortical properties and anomalous deformation splitting","We review a recent progress in investigation of the isoscalar toroidal dipole
resonance (TDR). A possible relation of the TDR and low-energy dipole strength
(also called a pygmy resonance) is analyzed. It is shown that the dipole
strength in the pygmy region can by understood as a local manifestation of the
collective vortical toroidal motion at the nuclear surface. Application of the
TDR as a measure of the nuclear dipole vorticity is discussed. Finally, an
anomalous splitting of the TDR in deformed nuclei is scrutinized.",1602.03326v1
2016-02-10,Progress in the calculation of nucleon transition form factors,"We give a brief account of the Dyson-Schwinger and Faddeev-equation approach
and its application to nucleon resonances and their transition form factors. We
compare the three-body with the quark-diquark approach and present a
quark-diquark calculation for the low-lying nucleon resonances including
scalar, axialvector, pseudoscalar and vector diquarks. We also discuss the
timelike structure of transition form factors and highlight the advantages of
form factors over helicity amplitudes.",1602.03462v1
2016-02-13,"Pure virtual braids, resonance, and formality","We investigate the resonance varieties, lower central series ranks, and Chen
ranks of the pure virtual braid groups and their upper-triangular subgroups. As
an application, we give a complete answer to the 1-formality question for this
class of groups. In the process, we explore various connections between the
Alexander-type invariants of a finitely generated group and several of the
graded Lie algebras associated to it, and discuss possible extensions of the
resonance-Chen ranks formula in this context.",1602.04273v2
2016-02-17,Shape reconstruction of nanoparticles from their associated plasmonic resonances,"We prove by means of a couple of examples that plasmonic resonances can be
used on one hand to classify shapes of nanoparticles with real algebraic
boundaries and on the other hand to reconstruct the separation distance between
two nanoparticles from measurements of their first collective plasmonic
resonances. To this end, we explicitly compute the spectral decompositions of
the Neumann-Poincar\'{e} operators associated with a class of quadrature
domains and two nearly touching disks. Numerical results are included in
support of our main findings.",1602.05268v1
2016-02-19,Impact of overlapping resonances on magnetoassociation of cold molecules in tight traps,"Overlapping Feshbach resonances are commonly observed in experiments with
ultracold atoms and can influence the molecule production process. We derive an
effective approach to describe magnetoassociation in an external trap in the
presence of multiple overlapping resonances. We study how the strength and
shape of the trap affects the energy level structure and demonstrate the
existence of a regime in which the conventional two-channel Landau-Zener
description of the molecule production process breaks down.",1602.06266v2
2016-02-23,Di-photon resonance and Dark Matter as heavy pions,"We analyse confining gauge theories where the 750 GeV di-photon resonance is
a composite techni-pion that undergoes anomalous decays into SM vectors. These
scenarios naturally contain accidentally stable techni-pions Dark Matter
candidates. The di-photon resonance can acquire a larger width by decaying into
Dark Matter through the CP-violating $\theta$-term of the new gauge theory
reproducing the cosmological Dark Matter density as thermal relic.",1602.07297v3
2016-02-24,Resonance Reaction in Diffusion-Influenced Bimolecular Reactions,"We investigate the influence of a stochastically fluctuating step-barrier
potential on bimolecular reaction rates by exact analytical theory and
stochastic simulations. We demonstrate that the system exhibits a new resonant
reaction behavior with rate enhancement if an appropriately defined fluctuation
decay length is of the order of the system size. Importantly, we find that in
the proximity of resonance the standard reciprocal additivity law for diffusion
and surface reaction rates is violated due to the dynamical coupling of
multiple kinetic processes. Together, these findings may have important
repercussions on the correct interpretation of various kinetic reaction
problems in complex systems, as, e.g., in biomolecular association or
catalysis.",1602.07469v1
2016-02-29,A medium-resolution monochromator for 73 keV x-rays - Nuclear resonant scattering of synchrotron radiation from 193-Ir,"We report on the development and characterization of a medium resolution
monochromator for synchrotron-based hyperfine spectroscopy at the 73 keV
nuclear resonance of 193-Ir. The device provides high throughput of 6*10^8 ph/s
in an energy bandwidth of 300(20) meV. We excited the nuclear resonance in
193-Ir at 73.04 keV and observed nuclear fluorescence of 193-Ir in Iridium
metal. The monochromator allows for Nuclear Forward Scattering spectroscopy on
Ir and its compounds.",1602.08874v1
2016-02-29,$Δ(1232)$ resonance in the $\vecγp\rightarrow pπ^0$ reaction at threshold,"We calculate the neutral pion photoproduction on the proton near threshold in
covariant baryon chiral perturbation theory, including the $\Delta(1232)$
resonance as an explicit degree of freedom, up to chiral order $p^{7/2}$ in the
$\delta$ counting. We compare our results with recent low-energy data from the
Mainz Microtron for angular distributions and photon asymmetries. The
convergence of the chiral series of the covariant approach is found to improve
substantially with the inclusion of the $\Delta(1232)$ resonance.",1602.08967v2
2016-03-08,Resonantly Enhanced Multiphoton Ionization under XUV FEL radiation: A case study of the role of harmonics,"We provide a detailed quantitative study of the possible role of a small
admixture of harmonics on resonant two-photon ionization. The motivation comes
from the occasional presence of 2nd and 3rd harmonics in FEL radiation. We
obtain the dependence of ionic yields on the intensity of the fundamental, the
percentage of 2nd harmonic and the detuning of the fundamental from resonance.
Having examined the cases of one and two intermediate resonances, we arrive at
results of general validity and global behavior, showing that even a small
amount of harmonic may seem deceptively innocuous.",1603.02482v1
2016-03-13,Minnaert resonances for acoustic waves in bubbly media,"Through the application of layer potential techniques and Gohberg-Sigal
theory we derive an original formula for the Minnaert resonance frequencies of
arbitrarily shaped bubbles. We also provide a mathematical justification for
the monopole approximation of scattering of acoustic waves by bubbles at their
Minnaert resonant frequency. Our results are complemented by several numerical
examples which serve to validate our formula in two dimensions.",1603.03982v1
2016-03-15,"Microcavity with saturable nonlinearity under simultaneous resonant and nonresonant pumping: multistability, Hopf bifurcations and chaotic behaviour","We studied optical response of microcavity non-equilibrium exciton-polariton
Bose-Einstein condensate with saturable nonlinearity under simultaneous
resonant and non-resonant pumping. We demonstrated the emergence of
multistabile behavior due to the satutration of the excitonic absorbtion.
Stable periodic Rabi- type oscillations of the excitonic and photonic
condensate components in the regime of the stationary pump and their transition
to the chaotic dynamics through the cascade of Hopf bifurcations by tuning of
the electrical pump are revealed.",1603.04612v1
2016-03-19,"Scattering, bound and quasi-bound states of the generalized symmetric Woods-Saxon potential","The exact analytical solutions of the Schr\""odinger equation for the
generalized symmetrical Woods-Saxon potential are examined for the scattering,
bound and quasi-bound states in one dimension. The reflection and transmission
coefficients are analytically obtained. Then, the correlations between the
potential parameters and the reflection-transmission coefficients are
investigated, and a transmission resonance condition is derived. Occurrence of
the transmission resonance has been shown when incident energy of the particle
is equal to one of the resonance energies of the quasi-bound states.",1603.06148v1
2016-03-22,Excitation of plasmonic nanoantennas with nonresonant and resonant electron tunnelling,"A rigorous theory of photon emission accompanied inelastic tunnelling inside
the gap of plasmonic nanoantennas has been developed. The disappointingly low
efficiency of the electrical excitation of surface plasmon polaritons in these
structures can be increased by orders of magnitude when a resonant tunnelling
structure is incorporated inside the gap. Resonant tunnelling assisted surface
plasmon emitter may become a key element in future electrically-driven
nanoplasmonic circuits.",1603.06721v1
2016-04-06,Topological Resonances on Quantum Graphs,"In this paper, we try to put the results of Smilansky and al. on ""Topological
resonances"" on a mathematical basis.A key role in the asymptotic of resonances
near the real axis for Quantum Graphs is played by the set of metrics for which
there exists compactly supported eigenfunctions. We give several estimateof the
dimension of this semi-algebraic set, in particular in terms of the girth of
the graph. The case oftrees is also discussed.",1604.01732v1
2016-04-11,Permanent matching of coupled optical bottle resonators with better than 0.16 GHz precision,"The fabrication precision is one of the most critical challenges on the way
to the creation of practical photonic circuits composed of coupled high
Q-factor microresonators. While very accurate transient tuning of
microresonators based on local heating has been reported, the record precision
of permanent resonance positioning achieved by post-processing is still within
1-5 GHz. Here we demonstrate two coupled bottle microresonators fabricated at
the fiber surface which resonances are matched with a better than 0.16 GHz
precision. This corresponds to a better than 0.17 angstrom precision in the
effective fiber radius variation. The achieved fabrication precision is only
limited by the resolution of our optical spectrum analyzer and can be
potentially improved by an order of magnitude.",1604.02982v1
2016-04-19,Design of nanobeam photonic crystal resonators for a silicon-on-lithium-niobate platform,"We outline the design for a photonic crystal resonator made in a hybrid
Silicon/Lithium Niobate material system. Using the index contrast between
silicon and lithium niobate, it is possible to guide and confine photonic
resonances in a thin film of silicon bonded on top of lithium niobate. Quality
factors greater than $10^6$ at optical wavelength scale mode volumes are
achievable. We show that patterning electrodes on such a system can yield an
electro-optic coupling rate of 0.6 GHz/V (4 pm/V).",1604.05647v1
2016-04-21,Interaction of two magnetic resonance modes in polar phase of superfluid 3He,"We report results of low frequency nuclear magnetic resonance (NMR)
experiments in the superfluid polar phase of 3He which is stabilized by a new
type of ""nematic"" aerogel - nafen. We have found that an interaction between
transverse and longitudinal NMR modes may essentially influence the spin
dynamics. Theoretical formulas for NMR resonant frequencies are derived and
applied for interpretation of the experimental results.",1604.06233v1
2016-04-28,On two different kinds of resonances in one-dimensional quantum-mechanical models,"We apply the Riccati-Pad\'{e} method and the Rayleigh-Ritz method with
complex rotation to the study of the resonances of a one-dimensional well with
two barriers. The model exhibits two different kinds of resonances and we
calculate them by means of both approaches. While the Rayleigh-Ritz method
reveals each set at a particular interval of rotation angles the Riccati
Pad\'{e} method yields both of them as roots of the same Hankel determinants.",1604.08444v2
2016-06-20,Semi-classical resonances associated with a periodic orbit of hyperbolic type,"We consider in this Note resonances for a $h$-Pseudo-Differential Operator
$H(x,hD_x;h)$ on $L^2(M)$ induced by a periodic orbit of hyperbolic type, as
arises for Schr\""odinger operator with AC Stark effect when $M={\bf R}^n$, or
the geodesic flow on an axially symmetric manifold $M$, extending Poincar\'e
example of Lagrangian systems with 2 degrees of freedom. We generalize the
framework of [G\'eSj], in the sense that we allow for hyperbolic and elliptic
eigenvalues of Poincar\'e map, and look for so-called semi-excited resonances
with imaginary part of magnitude $-h\log h$, or $h^s$, with $0<s<1$.",1606.06180v1
2016-06-30,Numeric calculation of antiferromagnetic resonance frequencies for the noncollinear antiferromagnet,"We present an algorithm for the numeric calculation of antiferromagnetic
resonance frequencies for the non-collinear antiferromagnets of general type.
This algorithm uses general exchange symmetry approach \cite{andrmar} and is
applicable for description of low-energy dynamics of an arbitrary noncollinear
spin structure in weak fields. Algorithm is implemented as a MatLab and C++
program codes, which are available for download. Program codes are tested
against some representative analytically solvable cases.",1606.09394v1
2016-07-13,Forward dispersion relations for pion-kaon scattering and the K*0(800) resonance,"We review our recent analysis of $\pi K$ scattering data in terms of forward
dispersion relations, and also present the parameters of the strange
resonances. This work consists of fits to the data that are constrained to
satisfy analyticity requirements. The method yields a set of simple and
consistent parameterizations that are compatible with forward dispersion
relations up to 1.6 GeV while still describing the data. We also obtain the
pole parameters of the $K^*_0(800)$ and the $K^*(892)$ resonances.",1607.03761v1
2016-07-14,Topological pumping of photons in nonlinear resonator arrays,"We show how to implement topological or Thouless pumping of interacting
photons in one dimensional nonlinear resonator arrays, by simply modulating the
frequency of the resonators periodically in space and time. The interplay
between interactions and the adiabatic modulations enables robust transport of
Fock states with few photons per site. We analyze the transport mechanism via
an effective analytic model and study its topological properties and its
protection to noise. We conclude by a detailed study of an implementation with
existing circuit QED architectures.",1607.04050v1
2016-07-15,Interplay of magnetic responses in all-dielectric oligomers to realize magnetic Fano resonances,"We study the interplay between collective and individual optically-induced
magnetic responses in quadrumers made of identical dielectric nanoparticles.
Unlike their plasmonic counterparts, all-dielectric nanoparticle clusters are
shown to exhibit multiple dimensions of resonant magnetic responses that can be
employed for the realization of anomalous scattering signatures. We focus our
analysis on symmetric quadrumers made from silicon nanoparticles and verify our
theoretical results in proof-of-concept radio frequency experiments
demonstrating the existence of a novel type of magnetic Fano resonance in
nanophotonics.",1607.04592v1
2016-07-19,Prediction for a four-neutron resonance,"We utilize various {\em ab initio} approaches to search for a low-lying
resonance in the four-neutron ($4n$) system using the JISP16 realistic $NN$
interaction. Our most accurate prediction is obtained using a $J$-matrix
extension of the No-Core Shell Model and suggests a $4n$ resonant state at an
energy near $E_r = 0.8$ MeV with a width of approximately $\Gamma = 1.4$ MeV.",1607.05631v2
2016-07-20,Exploring Peaks and Valleys in the Diphoton Spectrum,"We investigate the effects of resonance-continuum interference on the
diphoton spectrum in the presence of a new spin-0 or spin-2 state produced via
gluons or quarks and decaying to pairs of photons. Interference effects can
significantly influence the extraction of resonance masses and widths from the
diphoton spectrum, particularly in the case of a spin-2 resonance produced via
quarks. We illustrate these effects via a binned likelihood analysis of LHC
diphoton data at both 8 and 13 TeV.",1607.06074v2
2016-07-20,A microwave interferometer of the Michelson-type to improve the dynamic range of broadband ferromagnetic resonance measurements,"We present a Michelson-type microwave interferometer for use in ferromagnetic
resonance experiments. The interferometer is capable of broadband operation
without manual adjustment of phase delay or amplitude attenuation. A prototype
of the design shows significant improvement of the signal-to-noise ratio when
compared to non-interferometric ferromagnetic resonance experiments. We
demonstrate that this increase in sensitivity can lead to a drastic increase in
the data acquisition rate for hard-to-measure thin films that otherwise would
require long integration times.",1607.06137v2
2016-09-13,A two-way model for nonlinear acoustic waves in a non-uniform lattice of Helmholtz resonators,"Propagation of high amplitude acoustic pulses is studied in a 1D waveguide
connected to a lattice of Helmholtz resonators. An homogenized model has been
proposed by Sugimoto (J. Fluid. Mech., \textbf{244} (1992)), taking into
account both the nonlinear wave propagation and various mechanisms of
dissipation. This model is extended here to take into account two important
features: resonators of different strengths and back-scattering effects. An
energy balance is obtained, and a numerical method is developed. A closer
agreement is reached between numerical and experimental results. Numerical
experiments are also proposed to highlight the effect of defects and of
disorder.",1609.03841v2
2016-09-18,Dipolariton formation in quantum dot molecules strongly coupled to optical resonators,"In this theoretical work, we study a double quantum dot interacting strongly
with a microcavity, while undergoing resonant tunneling. Effects of interdot
tunneling on the light-matter hybridized states are determined, and tunability
of their brightness degrees and associated dipole moments is demonstrated.
These results predict dipolariton generation in artificial molecules coupled to
optical resonators, and provide a promising scenario for control of emission
efficiency and coherence times of exciton polaritons.",1609.05525v3
2016-09-28,Resonant Enhancement of Second Harmonic Generation by Edge States in Transition Metal Dichalcogenide Monolayers,"We derive a low-energy theory for edge states in transition metal
dichalcogenide monolayers for a two-band $\bm{kp}$-Hamiltonian in case of
uncoupled valleys. In the absence of spin-orbit interaction at the edge, these
states possess a linear dispersion described by a single phenomenological
parameter characterizing the edge structure. Depending on the sign of the
parameter, the edge state spectrum can either cross the band gap or lie outside
of it. In the first case, the presence of edge states leads to resonant
enhancement of the second harmonic generation at frequencies about the half of
the band gap, in agreement with recent experiments. The value of the
phenomenological boundary parameter is extracted from the resonance frequency
position.",1609.08946v1
2016-10-01,On the sigma sigma term,"We give some estimates for the light-quark mass dependence of the pole
position of the sigma ($f_{0}(500)$) resonance in the complex energy plane,
with the help of a chiral Lagrangian for the resonance field and some input
from hadronic models constrained by Chiral Perturbation Theory and elastic
unitarity. We also speculate on the fate of the sigma resonance when the quark
masses become unphysically large.",1610.00119v2
2016-10-04,Localization of massive and massless fermion on two field brane,"In this paper we study fermion localization and resonances on a special type
of braneworld model supporting brane splitting. In such models one can
construct multi-wall branes which cause considerable simplification in field
equations. We use a polynomial superpotential to construct this brane. The
suitable Yukawa coupling between the background scalar field and localized
fermion is determined. The massive fermion resonance spectrum is obtained. The
number of resonances is increased for higher values of Yukawa coupling.",1610.00899v1
2016-10-06,Calculation of Stark resonance parameters for valence orbitals of the water molecule,"An exterior complex scaling technique is applied to compute Stark resonance
parameters for two molecular orbitals ($1b_{1}$ and $1b_{2}$) represented in
the field-free limit in a single-center expansion. For electric DC field
configurations that guarantee azimuthal symmetry of the solution the
calculation is carried out by solving a two-dimensional partial differential
equation in spherical polar coordinates using a finite-element method. The
resonance positions and widths as a function of electric field strengths are
shown for field strengths starting in the tunnelling ionization regime, and
extending well into the over-barrier ionization region.",1610.01942v1
2016-10-07,Air modes of the Bacon internal resonator banjo,"Sound measurements on a sequence of related, similar constructions with
slightly different dimensions confirm a simple picture of the air modes of the
internal resonator banjo's body. For the purpose of this study, the air modes
are decoupled from the soundboard (i.e., [drum] head) modes by replacing the
head with 3/4"" plywood. The resulting characteristic features survive the
strong coupling of the air modes to the head and are in accord with the
qualitative distinctions recognized by banjo players.",1610.02355v1
2016-10-19,"Localization, quantum resonances and ratchet acceleration in a periodically-kicked $\mathcal{PT}$-symmetric quantum rotator","We consider wave transport phenomena in a $\mathcal{PT}$-symmetric extension
of the periodically-kicked quantum rotator model and reveal that dynamical
localization assists the unbroken $\mathcal{PT}$ phase. In the delocalized
(quantum resonance) regime, $\mathcal{PT}$ symmetry is always in the broken
phase and ratchet acceleration arises as a signature of unidirectional
non-Hermitian transport. An optical implementation of the periodically-kicked
$\mathcal{PT}$-symmetric Hamiltonian, based on transverse beam propagation in a
passive optical resonator with combined phase and loss gratings, is suggested
to visualize acceleration modes in fractional Talbot cavities.",1610.06007v1
2017-02-01,Localized surface plasmon resonance in graphene nanomesh with Au nanostructures,"A hybrid structure of a graphene nanomesh with the gold nanodisks is studied
to enhance the light absorption by localized surface plasmon resonance. From
the reflection spectra of the visible range for graphene nanomesh samples
without and with nanodisks, it is found that the absorption of graphene
nanomesh structures is greatly enhanced in the presence of gold nanodisks
around the resonance wavelength. Simulation results based on the
finite-difference time-domain method support the experimental observations.
This study demonstrates the potential of constructing graphene based
photodetectors with a high light absorption efficiency and wavelength
selectivity.",1702.00115v1
2017-02-13,Resonant Generation of an Electron-Positron Pair by Two Photons to Excited Landau Levels,"We consider the resonant generation of an electron-positron pair by two
polarized photons to arbitrarily low Landau levels. The resonance occurs when
the energy of one photon exceeds the one-photon generation threshold, and the
energy of the other photon is multiple to the spacing between the levels. The
cross section of the process is determined taking into account the spins of
particles. The order of magnitude of the cross section is the highest when the
magnetic moments of the particles are oriented along the magnetic field.",1702.03693v1
2017-03-04,Structure of 10N in 9C+p resonance scattering,"The structure of exotic nucleus 10N was studied using 9C+p resonance
scattering. Two L=0 resonances were found to be the lowest states in 10N. The
ground state of 10N is unbound with respect to proton decay by 2.2(2) or 1.9(2)
MeV depending on the 2- or 1- spin-parity assignment, and the first excited
state is unbound by 2.8(2) MeV.",1703.01366v1
2017-03-11,Resonance Absorption of Terahertz Radiation in Nanoperforated Graphene,"Recent measurements of the conductivity of nanoperforated graphene are
interpreted in terms of edges states existing near the edge of each nanohole.
The perimetric quantization of edge states should result in the formation of a
quasi-equidistant ladder of quasistationary energy levels. Dirac fermions
filling this ladder rotate about each nanohole in the direction determined by
the valley index. It is shown that the irradiation of this system by circularly
polarized terahertz radiation leads to a resonance in absorption in one of the
valleys. The magnitude of absorption at the resonance frequency can be
controlled by means of gate voltage.",1703.03979v1
2017-03-15,Coherent Transport of Levitons Through the Kondo Resonance,"We study coherent transport of levitons through a single-level quantum dot
system driven by Lorentzian-shaped voltage pulses. We demonstrate the repeated
emergence of the Kondo resonance in the dynamical regimes where the Fermi sea
is driven by optimal pulses free of particle-hole excitations. The formation of
the Kondo resonance significantly enhances the dc transport of levitons.",1703.05198v2
2017-03-17,A simple model for a scalar two-point correlator in the presence of a resonance,"We present a simple toy model for a scalar-isoscalar two-point correlator,
which can serve as a testing ground for the extraction of resonance parameters
from Lattice QCD calculations. We discuss in detail how the model correlator
behaves when it is restricted to a finite spatial volume, and how the
finite-volume data can be used to reconstruct the spectral function of the
correlator in the infinite volume, which allows to extract properties of the
resonance from such data.",1703.05940v1
2017-03-23,Spectral analysis of morse-smale flows ii: resonances and resonant states,"The goal of the present work is to compute explicitely the correlation
spectrum of a Morse-Smale flow in terms of the Lyapunov exponents of the
Morse--Smale flow, the topology of the flow around periodic orbits and the
monodromy of some given flat connection. The corresponding eigenvalues exhibit
vertical bands when the flow has periodic orbits. As a corollary, we obtain
sharp Weyl asymptotics for the dynamical resonances.",1703.08038v1
2017-03-24,Extreme values of the Riemann zeta function on the 1-line,"We prove that there are arbitrarily large values of $t$ such that
$|\zeta(1+it)| \geq e^{\gamma} (\log_2 t + \log_3 t) + \mathcal{O}(1)$. This
essentially matches the prediction for the optimal lower bound in a conjecture
of Granville and Soundararajan. Our proof uses a new variant of the ""long
resonator"" method. While earlier implementations of this method crucially
relied on a ""sparsification"" technique to control the mean-square of the
resonator function, in the present paper we exploit certain self-similarity
properties of a specially designed resonator function.",1703.08315v2
2017-08-07,Formation and Deformation of the $ψ(3770)$,"The form of resonance line-shapes unveils information about its
nonperturbative properties and formation mechanisms. Here, we study the
non-Breit-Wigner energy distribution of the resonance $\psi (3770)$ using an
unitarized effective Lagrangian approach, that includes the effect of the
nearby threshold $D^{+}D^{-}$. Two poles are found in the second Riemann sheet
near the resonance amplitude. We discuss the setting of the free parameters and
possible effects contributing to the signal.",1708.02041v2
2017-08-09,Searching for New High Mass Phenomena Decaying to Muon Pairs using Proton-Proton Collisions at $\sqrt{s}$ = 13 TeV with the ATLAS Detector at the LHC,"We present a search for new high mass phenomena using the latest data
collected by the ATLAS detector at the LHC, corresponding to 36.1 fb$^{-1}$ at
$\sqrt{s}$ = 13 TeV. The search is conducted for both resonant and non-resonant
new phenomena in dimuon final states. The dimuon invariant mass spectrum is the
discriminating variable used in the search. No significant deviations from the
Standard Model expectation are observed. Lower limits are set on the signal
parameters of interest at 95% credibility level, using a Bayesian
interpretation. In particular, a Sequential Standard Model Z' resonance is
excluded for masses below 4.0 TeV.",1708.03033v1
2018-02-01,Phase Stochastic Resonance in a forced nano-electromechanical oscillator,"Stochastic resonance is a general phenomenon usually observed in
one-dimensional, amplitude modulated, bistable systems.We show experimentally
the emergence of phase stochastic resonance in the bidimensional response of a
forced nano-electromechanical membrane by evidencing the enhancement of a weak
phase modulated signal thanks to the addition of phase noise. Based on a
general forced Duffing oscillator model, we demonstrate experimentally and
theoretically that phase noise acts multiplicatively inducing important
physical consequences. These results may open interesting prospects for phase
noise metrology or coherent signal transmission applications in nanomechanical
oscillators. Moreover, our approach, due to its general character, may apply to
various systems.",1802.00213v1
2018-02-13,Loop-gap Microwave Resonator for Hybrid Quantum Systems,"We designed a loop-gap microwave resonator for applications of spin-based
hybrid quantum systems, and tested it with impurity spins in diamond. Strong
coupling with ensembles of nitrogen-vacancy (NV) centers and substitutional
nitrogen (P1) centers was observed. These results show that loop-gap resonators
are viable in the prospect of spin-based hybrid quantum systems, especially for
an ensemble quantum memory or a quantum transducer.",1802.04485v2
2018-02-15,Direct Measurement of Coating Thermal Noise in Optical Resonators,"The best measurements of space and time currently possible (e.g.
gravitational wave detectors and optical reference cavities) rely on optical
resonators, and are ultimately limited by thermally induced fluctuations in the
reflective coatings which form the resonator. We present measurements of
coating thermal noise in the audio band and show that for a standard ion beam
sputtered coating, the power spectrum of the noise does not have the expected
power-law behavior.",1802.05372v2
2018-02-19,Emission of autoresonant trajectories and thresholds of resonant pumping,"We study an autoresonant asymptotic behaviour for nonlinear oscillators under
slowly changing frequency and amplitude of external driver. As a result we
obtain formulas for threshold values of amplitude and frequency of the driver
when autoresonant behaviour for the nonlinear oscillator is observed. Also we
study a capture into resonance and emission out of the resonance for
trajectories of the oscillator. A measure of autoresonant asymptotic behaviours
for nonlinear oscillator is obtained.",1802.06717v1
2018-02-20,Electron emission by long and short wavelength lasers: essentials for the design of plasmonic photocathodes,"Theory of electron emission by metallic photocathodes under the exposure of
long wavelength lasers will be studied. Energy of photons in long wavelength
lasers is less than the work function of the photocathode material, and can
only emit electrons via tunneling through the potential barrier. The optical
resonance effect (e.g. plasmonic resonances) will be studied as an improvement
to the performance of photocathodes. This paper is intended to provide
self-sufficient materials to design optical resonant surfaces (e.g.
metasurfaces) for electron emission applications.",1802.06945v1
2018-02-21,Differential Bandpass Filters Based on Dumbbell-Shaped Defected Ground Resonators,"This letter presents a dumbbell-shaped defected ground resonator and its
application in the design of differential filters. The operation principle of
the dumbbell-shaped resonator (DSR) coupled to differential microstrip lines is
studied through a circuit model analysis. The proposed circuit model is
validated through the comparison with the electromagnetic simulation results.
It is shown that the bandpass configuration of microstripline- coupled DSR can
be used to design higher order bandpass filters. The design procedure is
explained by developing a thirdorder filter prototype. The designed filter
shows more than 57 dB common mode rejection within the differential passband.",1802.07406v1
2018-03-10,Highly Sensitive and Robust Ultrahigh-Q Nanocavity on a Multiheterostructure Photonic Crystal,"An ultrahigh-Q hybrid cavity using a graded multiheterostructure and space
modulation is designed in this work. Two high Q resonant modes exist in the
cavity and follow separate confinement mechanisms. We have demonstrated an
analytical method for designing the desired multiheterostructure. Space
modulation was used to create a robust and sensitive nanocavity. The
confinement mechanism and resonant characteristics of the resonant modes are
studied using the finite difference time domain method. We have shown that the
modes of the cavity are highly robust with respect to fabrication error. We
have also demonstrated that the nanocavity can act as a highly sensitive
refractive index sensor.",1804.01842v1
2018-04-16,Analysis of surface polariton resonance for nanoparticles in elastic system,"This paper is concerned with the analysis of surface polariton resonance for
nanoparticles in linear elasticity. With the presence of nanoparticles, we
first derive the perturbed displacement field associated to a given elastic
source field. It is shown that the leading-order term of the perturbed elastic
wave field is determined by the Neumann-Poinc\'are operator associated to the
Lam\'e system. By analyzing the spectral properties of the aforesaid
Neumann-Poinc\'are operator, we study the polariton resonance for the elastic
system. The results may find applications in elastic wave imaging.",1804.05480v1
2018-11-05,Surface acoustic wave coupled to magnetic resonance on a multiferroic CuB$_2$O$_4$,"We observed surface acoustic wave (SAW) propagation on a multiferroic
material CuB$_2$O$_4$ with use of two interdigital transducers (IDTs). The
period of IDT fingers is as short as 1.6 $\mu$m so that the frequency of SAW is
3 GHz, which is comparable with that of magnetic resonance. In
antiferromagnetic phase, the SAW excitation intensity varied with the magnitude
and direction of the magnetic field, owing to the dynamical coupling between
SAWs and antiferromagnetic resonance of CuB$_2$O$_4$. The microscopic mechanism
is discussed based on the symmetrically allowed magentoelastic coupling.",1811.01527v1
2018-11-07,Two-nucleon emitters within a pseudostate approach,"A method to identify and characterize three-body resonances in a discrete
basis is discussed in the context of two-nucleon emitters. For this purpose, a
resonance operator is introduced and diagonalized in a basis of energy
pseudostates within the hyperspherical formalism. Then, the energy and width of
the resonance are obtained from its time dependence. The approach is
illustrated for $^{16}$Be ($^{14}\text{Be}+n+n$).",1811.02826v3
2018-11-14,Resonance properties from lattice energy levels using chiral effective field theory,"We use the chiral effective field theory to study the lattice finite-volume
energy levels from the meson-meson scattering. The hadron resonance properties
and the scattering amplitudes at physical masses are determined from the
lattice energy levels calculated at unphysically large pion masses. The results
from the $\pi\eta, K\bar{K}$ and $\pi\eta'$ coupled-channel scattering and the
$a_0(980)$ resonance are explicitly given as a concrete example.",1811.05582v1
2018-11-15,"Charged scalar fields in a Kerr-Sen black hole: exact solutions, Hawking radiation, and resonant frequencies","In this study, we consider charged massive scalar fields around a Kerr-Sen
spacetime. The radial and angular parts of the covariant Klein-Gordon equation
are solved in terms of the confluent Heun function. From the exact radial
solution, we obtain the Hawking radiation spectrum and discuss its resonant
frequencies. The massless case of the resonant frequencies is also examined.",1811.06129v2
2018-11-23,Hadron gas with repulsive mean field,"We study the QCD equation of state, and fluctuations of baryon number and
strangeness using the hadron resonance gas model with repulsive mean field. We
find that including both the predicted but not observed resonances, a.k.a.
missing states, and the repulsive mean field into the resonance gas model leads
to better description of the lattice results. The repulsive mean field is
particularly important for the higher order baryon number fluctuations.",1811.09330v1
2019-05-06,Transverse polarization light scattering in tubular semiconductor nanowires,"We carry out numerical calculations of the scattering cross section of
tubular semiconductor nanocylinders in the optical range. The scattering is
investigated for the transversal incidence of light, i.e., along the diameter
of the cylinder, with both transverse electric and transverse magnetic
polarization. These subwavelength nanostructures support Mie resonances and,
when the length of the cylinder is comparable to the wavelength, guided modes
that can overlap with the Mie modes giving rise to sharp Fano resonances. We
show that a varying internal radius affects each mode differently, allowing for
an extra degree of freedom for tuning the spectral position of the resonant
peaks.",1905.02268v1
2019-05-10,Bound-State Band Reconstruction and Resonance in Spin-1/2 Bose Gas with 1D Spin-Orbit Coupling,"In this work, we study two-body bound states in two-component Bose gas with a
one-dimensional (1D) spin-orbit coupling (SOC) induced by Raman lasers. The
finite Raman coupling strength generates coupling among three spin channels,
resulting in the reconstruction of three bound-state bands. In addition,
multiple resonances can be induced at finite scattering lengths. By tuning the
interaction in one intra-species channel, one bound-state band can be lifted
and three resonances can be achieved at different center-of-mass momenta, which
can be observable under current experimental conditions in ${}^{87}$Rb atoms.",1905.03979v1
2019-05-15,Dipolar polaritons squeezed at unitarity,"Interaction of dipolar polaritons can be efficiently tuned by means of a
shape resonance in their excitonic component. Provided the resonance width is
large, a squeezed population of strongly interacting polaritons may persist on
the repulsive side of the resonance. We derive an analytical expression for the
polariton coupling constant and show that it may have very large values in
typical experimental conditions. Our arguments provide a new direction for the
quest of interactions in quantum photonics.",1905.06418v2
2019-05-29,Is the $Y(2175)$ a Strangeonium Hybrid Meson?,"QCD Gaussian sum-rules are used to explore the vector ($J^{PC}=1^{--}$)
strangeonium hybrid interpretation of the $Y(2175)$. Using a two-resonance
model consisting of the $Y(2175)$ and an additional resonance, we find that the
relative resonance strength of the $Y(2175)$ in the Gaussian sum-rules is less
than 5\% that of a heavier 2.9 GeV state. This small relative strength presents
a challenge to a dominantly-hybrid interpretation of the $Y(2175)$.",1905.12779v2
2020-07-08,$Λ$ and $Σ$ Excitations and the Quark Model,"The spectrum of $\Lambda$ and $\Sigma$ excitations is reviewed taking into
account (nearly) all hyperon resonances which were seen in early analyses or in
one of the recent partial-wave analyses. The spectrum is compared with the old
Isgur-Karl model and the Bonn model. These models allows us to discuss the
SU(3) structure of the observed resonances. The SU(3) decomposition is compared
with SU(6) relations between the different decay modes. Seven $\Lambda$ states
are proposed to be classified as SU(3) singlet states. The hyperon spectrum is
compared with the spectrum of $N$ and $\Delta$ resonances.",2007.04232v1
2020-07-15,Perfectly matched layer method for optical modes in dielectric cavities,"The optical resonance problem is similar to but different from time-steady
Schr\""{o}dinger equation. One big challenge is that the eigenfunctions in
resonance problem is exponentially growing. We give physical explanation to
this boundary condition and introduce perfectly matched layer (PML) method to
transform eigenfunctions from exponential-growth to exponential-decay. Based on
the complex stretching technique, we construct a non-Hermitian Hamiltonian for
the optical resonance problem. We successfully validate the effectiveness of
the Hamiltonian by calculate its eigenvalues in the circular cavity and compare
with the analytical results. We also use the proposed Hamiltonian to
investigate the mode evolution around exceptional points in the quad-cosine
cavity.",2007.07558v2
2020-07-21,Visualizing resonances in finite volume,"In present work, we explore and experiment an alternative approach of
studying resonance properties in finite volume. By analytic continuing finite
lattice size $L$ into complex plane, the oscillating behavior of finite volume
Green's function is mapped into infinite volume Green's function corrected by
exponentially decaying finite volume effect. The analytic continuation
technique thus can be applied to study resonance properties directly in finite
volume dynamical equations.",2007.10895v2
2020-07-21,A Hybrid (Al)GaAs-LiNbO$_3$ Surface Acoustic Wave Resonator for Cavity Quantum Dot Optomechanics,"A hybrid device comprising a (Al)GaAs quantum dot heterostructure and a
LiNbO$_3$ surface acoustic wave resonator is fabricated by heterointegration.
High acoustic quality factors $Q>4000$ are demonstrated for an operation
frequency $f\approx 300$ MHz. The measured large quality factor-frequency
products $Q\times f>10^{12}$ ensures the suppression of decoherence due to
thermal noise for temperatures exceeding $T>50\,\mathrm{K}$. Frequency and
position dependent optomechanical coupling of single quantum dots and the
resonator modes is observed.",2007.11082v2
2010-05-03,On Fluctuations of Conserved Charges : Lattice Results Versus Hadron Resonance Gas,"We compare recent lattice results on fluctuations and correlations of
strangeness, baryon number and electric charge obtained with p4 improved
staggered action with the prediction of hadron resonance gas model. We show
that hadron resonance gas can describe these fluctuations reasonably well if
the hadron properties are as calculated on the lattice.",1005.0324v1
2010-05-04,Spectator Behavior in a Quantum Hall Antidot with Multiple Bound Modes,"We theoretically study Aharonov-Bohm resonances in an antidot system with
multiple bound modes in the integer quantum Hall regime, taking capacitive
interactions between the modes into account. We find the spectator behavior
that the resonances of some modes disappear and instead are replaced by those
of other modes, due to internal charge relaxation between the modes. This
behavior is a possible origin of the features of previous experimental data
which remain unexplained, spectator behavior in an antidot molecule and
resonances in a single antidot with three modes.",1005.0450v1
2010-05-04,Neutron scattering in the hole-doped cuprate superconductors,"The occurrence of a neutron resonance energy is a common feature of
unconventional superconductors. In turn, the low-temperature incommensurate
sharp peaks observed in the inelastic neutron scattering of
La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) correspond to four rods symmetrically
distributed around $[\pi,\pi]$. Here it is shown that within the
virtual-electron pair quantum liquid recently introduced the neutron resonance
energy and the LSCO low-temperature incommensurate sharp peaks are generated by
simple and closely related spinon processes. Our results indicate that in LSCO
the neutron resonance energy either does not occur or corresponds to a lower
energy $\approx 17$ meV.",1005.0601v1
2010-05-19,Emerging beam resonances in atom diffraction from a reflection grating,"We report on the observation of emerging beam resonances, well known as
Rayleigh-Wood anomalies and threshold resonances in photon and electron
diffraction, respectively, in an atom-optical diffraction experiment.
Diffraction of He atom beams reflected from a blazed ruled grating at grazing
incidence has been investigated. The total reflectivity of the grating as well
as the intensities of the diffracted beams reveal anomalies at the Rayleigh
angles of incidence, i.e., when another diffracted beam merges parallel to the
grating surface. The observed anomalies are discussed in terms of the classical
wave-optical model of Rayleigh and Fano.",1005.3467v1
2010-05-28,Quantum decoherence in a hybrid atom-optical system of a one-dimensional coupled-resonator waveguide and an atom,"Decoherence for a one-dimensional coupled-resonator waveguide with a
two-level system inside one of resonators, induced by their interaction with
corresponding environments, is investigated. Each environment is modeled as a
continuum of harmonic oscillators. By finding the eigenstates of the hybrid
system, which is the dressed state of the hybrid system, we calculate the
lifetime of one excitation, which characterizes the existence of quantum
coherence in such hybrid system and the basic quantum nature.",1005.5224v2
2010-05-28,Electromagnetic and phonon modes for superfluid He-4 with a disk resonator,"We find the distribution of the electromagnetic field inside and outside a
dielectric disk resonator placed in He-II. It is shown that this field consists
of a collection of ""circular"" (c-) photons. The wave function \Psi_c of a
c-phonon for the He-II + disk system is calculated in the zero-order
approximation in interaction. Due to the symmetry of the problem, the structure
of \Psi_c is such that a c-phonon possesses, similarly to a c-photon of the
resonator, a definite energy and an angular momentum with respect to the disk
axis, but it does not possess a definite momentum in the disk plane.",1005.5282v1
2013-08-01,Reservoir engineering of a mechanical resonator: generating a macroscopic superposition state and monitoring its decoherence,"A deterministic scheme for generating a macroscopic superposition state of a
nanomechanical resonator is proposed. The nonclassical state is generated
through a suitably engineered dissipative dynamics exploiting the
optomechanical quadratic interaction with a bichromatically driven optical
cavity mode. The resulting driven dissipative dynamics can be employed for
monitoring and testing the decoherence processes affecting the nanomechanical
resonator under controlled conditions.",1308.0259v2
2013-08-01,Field Theory of the d+t -> n+alpha Reaction Dominated by a 5He* Unstable Particle,"An effective, non-relativistic field theory for low-energy d+t -> n+alpha
reaction is presented. The theory assumes that the reaction is dominated by an
intermediate 5He* unstable spin 3/2+ resonance. It involves two parameters in
the coupling of the d+t and n+alpha particles to the unstable resonant state,
and the resonance energy level -- only three real parameters in all. All
Coulomb corrections to this process are computed. The resultant field theory is
exactly solvable and provides an excellent description of the d+t fusion
process.",1308.0347v1
2013-08-08,Planar Superconducting Whispering Gallery Mode Resonators,"We introduce a microwave circuit architecture for quantum signal processing
combining design principles borrowed from high-Q 3D resonators in the quantum
regime and from planar structures fabricated with standard lithography. The
resulting '2.5D' whispering-gallery mode resonators store 98% of their energy
in vacuum. We have measured internal quality factors above 3 million at the
single photon level and have used the device as a materials characterization
platform to place an upper bound on the surface resistance of thin film
aluminum of less than 250nOhms.",1308.1743v2
2013-08-10,Parametric patterns in optical fiber ring nonlinear resonators,"We propose that parametrically excited patterns, also known as Faraday
patterns, can be observed in nonlinear fiber resonators, where the coefficient
of Kerr nonlinearity is periodically varying along the fiber in resonator. We
study the parametric instability analytically on the basis of the Floquet
theory, also numerically, by direct integration of the system. Instead of
classical Faraday wave excitation scenario, where modulation in time causes
formation of patterns in space, here we propose an inverted scenario, where the
modulation in space excites the patterns in time.",1308.2279v1
2013-08-19,Simulation of Self-Pulsing in Kerr-Nonlinear Coupled Ring Resonators,"Nonlinear resonant structures consisting of coupled ring resonators can be
modeled by difference-differential equations that take into account
non-instantaneous Kerr response and the effect of loss. We present a simple and
efficient numerical formalism for solution of the system and calculation of the
time evolution. The technique is demonstrated by investigating the dynamical
behavior of the coupled structure with two rings, namely, focusing on
self-pulsing solutions. The influence of both, loss and non-instantaneous Kerr
response, is also presented.",1308.3981v1
2013-08-19,Kondo resonance from vacancies in graphene,"Using the slave-rotor mean-field theory, we study the formation of Kondo
resonance in graphene induced from vacancies. At the Dirac neutrality point, we
find acritical hybridization strength beyond which the Kondo resonance takes
place, despite vanishing density of states. We also find that the line-shapes
of the Kondo peak are entirely different from Lorentzian shown in normal
metallic hosts. The dependence of Kondo temperature on the effective
hybridization parameter of the spinon field turns out to be linear in contrast
to the quadratic dependence in normal metals. Upon doping we find strong
electron-hole asymmetry for the dependence of Kondo temperature on the chemical
potential.",1308.4173v1
2013-08-22,Ultra-compact tunable split-ring resonators,"We propose tunable superconducting split-ring resonators (SRRs) employing
nonlinear Josephson inductance. A fraction of SRR is replaced by Nb-AlOx-Nb
Josephson tunnel junctions connected in parallel and forming a superconducting
quantum interference device (SQUID), whose inductance is sensitive to the
external dc magnetic field. Due to the lumped nature of the Josephson
inductance, the SRR can be made very compact and its resonance frequency can be
tuned by applying magnetic field. We present the model, results of extensive
EM-simulation and experimental data for the SRR weakly coupled to a
transmission line within frequency range 11-13 GHz.",1308.4891v1
2013-08-27,Level repulsion in hybrid photonic-plasmonic microresonators for enhanced biodetection,"We theoretically analyse photonic-plasmonic coupling between a high Q
whispering gallery mode (WGM) resonator and a core-shell nanoparticle. Blue and
red shifts of WGM resonances are shown to arise from crossing of the photonic
and plasmonic modes. Level repulsion in the hybrid system is further seen to
enable sensitivity enhancements in WGM sensors: maximal when the two resonators
are detuned by half the plasmon linewidth. Approximate bounds are given to
quantify possible enhancements. Criteria for reactive vs. resistive coupling
are also established.",1308.5780v1
2014-03-02,Power spectrum of the geodesic flow on hyperbolic manifolds,"We describe the complex poles of the power spectrum of correlations for the
geodesic flow on compact hyperbolic manifolds in terms of eigenvalues of the
Laplacian acting on certain natural tensor bundles. These poles are a special
case of Pollicott-Ruelle resonances, which can be defined for general Anosov
flows. In our case, resonances are stratified into bands by decay rates. The
proof also gives an explicit relation between resonant states and eigenstates
of the Laplacian.",1403.0256v2
2014-03-05,Resonant detection of axion mediated forces with Nuclear Magnetic Resonance,"We describe a method based on precision magnetometry that can extend the
search for axion-mediated spin-dependent forces by several orders of magnitude.
By combining techniques used in nuclear magnetic resonance and short-distance
tests of gravity, our approach can substantially improve upon current
experimental limits set by astrophysics, and probe deep into the theoretically
interesting regime for the Peccei-Quinn (PQ) axion. Our method is sensitive to
PQ axion decay constants between 10^9 and 10^12 GeV or axion masses between
10^-6 and 10^-3 eV, independent of the cosmic axion abundance.",1403.1290v1
2014-03-06,Infrared light detection using a whispering-gallery-mode optical microcavity,"We demonstrate a thermal infrared (IR) detector based on an
ultra-high-quality-factor (Q) whispering-gallery-mode (WGM) microtoroidal
silica resonator, and investigate its performance to detect IR radiation at 10
micron wavelength. The bandwidth and the sensitivity of the detector are
dependent on the power of a probe laser and the detuning between the probe
laser and the resonance frequency of the resonator. The microtoroid IR sensor
achieved a noise-equivalent-power (NEP) of 7.46 nW, corresponding to IR
intensity of 0.095 mW/cm^2",1403.1559v1
2014-03-12,Graphene optomechanics realized at microwave frequencies,"Cavity optomechanics has served as a platform for studying the interaction
between light and micromechanical motion via radiation pressure. Here we
observe such phenomena with a graphene mechanical resonator coupled to an
electromagnetic mode. We measure thermal motion and back-action cooling in a
bilayer graphene resonator coupled to a microwave on-chip cavity. We detect the
lowest flexural mode at 24 MHz down to 50 mK, corresponding to roughly
mechanical 40 quanta, representing nearly three orders of magnitude lower
phonon occupation than recorded to date with graphene resonators.",1403.2965v1
2014-03-18,Single-photon Spectra in Quantum Optomechanics,"We consider how a single photon can probe the quantum nature of a moving
mirror in the context of quantum optomechanics. In particular, we demonstrate
how the single-photon spectrum reveals resonances that depend on how many
phonons are created as well as on the strength of the mirror-photon
interaction. A dressed-state picture is used to explain positions and relative
strengths of those resonances. The time-dependent spectrum shows how the
resonances are built up over time by the photon interacting with the moving
mirror.",1403.4649v1
2014-03-20,Waveguide Model for Thick Complementary Split Ring Resonators,"This paper presents a very simple analytical model for the design of
Frequency Selective Surfaces based on Complementary Split Ring Resonators
(CSRR) within the microwave range. Simple expressions are provided for the most
important geometrical parameters of the model, yielding an accurate description
of the CSRR resonance frequency and avoiding full-wave numerical simulations.
Besides, a qualitative description of the band-pass filter behavior of these
structures is described, considering its high quality factor Q.",1403.5139v1
2014-03-22,Poisson wave trace formula for perturbed Dirac operators,"We consider self-adjoint Dirac operators $\ham{D}=\ham{D}_0 + V(x)$, where
$\ham{D}_0$ is the free three-dimensional Dirac operator and $V(x)$ is a smooth
compactly supported Hermitian matrix. We define resonances of $\ham{D}$ as
poles of the meromorphic continuation of its cut-off resolvent. An upper bound
on the number of resonances in disks, an estimate on the scattering determinant
and the Lifshits-Krein trace formula then leads to a global Poisson wave trace
formula for resonances of $\ham{D}$.",1403.5654v1
2014-03-28,Realization of cavity linewidth narrowing via interacting dark resonances in a tripod-type electromagnetically induced transparency system,"Cavity linewidth narrowing via double-dark resonances has been experimentally
observed using the 87Rb Zeeman splitting sublevels. With the steep dispersion
led by the interacting dark resonances in the tripodtype electromagnetically
induced transparency system, we narrow the cavity linewidth to 250 KHz at room
temperature. Furthermore, the position of this ultranarrow cavity linewidth
could be tuned in a 60 MHz coupling field detuning range.",1403.7346v1
2016-11-01,de Sitter as a Resonance,"A quantum mechanical formulation of de Sitter cosmological spacetimes still
eludes string theory. In this paper we conjecture a potentially rigorous
framework in which the status of de Sitter space is the same as that of a
resonance in a scattering process. We conjecture that transition amplitudes
between certain states with asymptotically supersymmetric flat vacua contain
resonant poles characteristic metastable intermediate states. A calculation
employing constrained instantons illustrates this idea.",1611.00360v3
2016-11-03,Anomalous excitation facilitation in inhomogeneously broadened Rydberg gases,"When atomic gases are laser driven to Rydberg states in an off resonant way,
a single Rydberg atom may enhance the excitation rate of surrounding atoms.
This leads to a facilitated excitation referred to as Rydberg anti-blockade. In
the usual facilitation scenario, the detuning of the laser from resonance
compensates the interaction shift. Here, we discuss a different excitation
mechanism, which we call anomalous facilitation. This occurs on the ""wrong
side"" of the resonance and originates from inhomogeneous broadening. The
anomalous facilitation may be seen in experiments of attractively interacting
atoms on the blue detuned side, where facilitation is not expected to appear.",1611.01085v1
2016-11-07,Linear absorption coefficient of in-plane graphene on a silicon microring resonator,"We demonstrate that linear absorption coefficient (LAC) of a graphene-silicon
hybrid waveguide (GSHW) is determined by the optical transmission spectra of a
graphene coated symmetrically coupled add-drop silicon microring resonator
(SC-ADSMR), of which the value is around 0.23 dB/um. In contrast to the
traditional cut-back method, the measured results are not dependent on the
coupling efficiency of the fiber tip and the waveguide. Moreover, precision
evaluation of graphene coated silicon microring resonator (SMR) is crucial for
the optoelectronic devices targeting for compact footprint and low power
consumption.",1611.02051v1
2016-11-10,de Sitter Harmonies: Cosmological Spacetimes as Resonances,"The aim of this work is to provided the details of a calculation summarized
in the recent paper by Maltz and Susskind which conjectured a potentially
rigorous framework where the status of de Sitter space is the same as that of a
resonance in a scattering process. The conjecture being that transition
amplitudes between certain states with asymptotically supersymmetric flat vacua
contain resonant poles characteristic metastable intermediate states. A
calculation employing constrained instantons is presented that illustrates this
idea.",1611.03491v2
2016-11-22,Photons Squeezing Model in a Nonlinear Micro-ring Resonator,"Principally, there are two forms of coupling energy when particle(photon) is
moving around the micro-ring resonator, which is generated by the construction
(creation) and the destruction (annihilation) energies that can disturb the
centre nonlinear microring resonator and lead the system unstable from the
harmonic motion, from which the squeezing state of the particle can occur. The
detected outputs either electrons and their spins or photons can be useful for
the new era of electronic devices and circuits, where the classical
electronics, plasmonic electronics, spintronic electronics and quantum
electronics can be combined and realized.",1611.07520v3
2016-11-25,New ISR Cross Section Results on KS KL pi0 and KS KL pi0 pi0 From BABAR,"We present preliminary measurements of the cross sections for e+e- --> KS KL
pi0 and KS KL pi0 pi0 obtained using the technique of Initial State Radiation
with 469 fb^-1 of e+e- collision data collected with the BABAR detector at or
near the Upsilon(4S) resonance. The resonant substructure of KS KL pi0 is
investigated, and branching fractions for the decays of the charmonium
resonances J/psi and psi(2S) into these final states are measured.",1611.08441v1
2016-11-29,30-Hz relative linewidth watt output power 1.65-$μ$m continuous-wave singly resonant optical parametric oscillator,"We built a 1-watt cw singly resonant optical parametric oscillator operating
at an idler wavelength of 1.65~$\mu$m for application to quantum interfaces.
The non resonant idler is frequency stabilized by side-fringe locking on a
relatively high-finesse Fabry-Perot cavity, and the influence of intensity
noise is carefully analyzed. A relative linewidth down to the sub-kHz level
(about 30 Hz over 2 s) is achieved. A very good long term stability is obtained
for both frequency and intensity.",1611.09659v3
2017-01-08,$CP$ violation induced by the double resonance for pure annihilation decay process in Perturbative QCD,"In Perturbative QCD (PQCD) approach we study the direct $CP$ violation in the
pure annihilation decay process of
$\bar{B}^0_{s}\rightarrow\pi^+\pi^-\pi^+\pi^-$ induced by the $\rho$ and
$\omega$ double resonance effect. Generally, the $CP$ violation is small in the
pure annihilation type decay process. However, we find that the $CP$ violation
can be enhanced by double $\rho-\omega$ interference when the invariant masses
of the $\pi^+\pi^-$ pairs are in the vicinity of the $\omega$ resonance. For
the decay process of $\bar{B}^0_{s}\rightarrow\pi^+\pi^-\pi^+\pi^-$, the
maximum $CP$ violation can reach 28.64{\%}.",1701.01966v1
2017-01-15,Side resonances and metastable excited state of NV- center in diamond,"We discuss the side resonances of optically detected magnetic resonance in
diamond crystal and propose the new approach to the calculation of hyperfine
interaction in composed system, consisted of negatively charged
nitrogen-vacancy NV- center and nearby 13C nuclear spin. Energy levels and spin
states are obtained by new method. The base of this method is the using of
complete set of commuting operators. In zero magnetic field, predicted the
existence of metastable excited state.",1701.04097v1
2017-01-19,Topology optimization of multi-track ring resonators and 2D microcavities for nonlinear frequency conversion,"We exploit recently developed topology-optimization techniques to design
complex, wavelength-scale resonators for enhancing various nonlinear
$\chi^{(2)}$ and $\chi^{(3)}$ frequency conversion processes. In particular, we
demonstrate aperiodic, multi-track ring resonators and 2D slab microcavities
exhibiting long lifetimes $Q \gtrsim 10^4$, small modal volumes $V \gtrsim
(\lambda/2n)^3$, and among the largest nonlinear overlaps (a generalization of
phase matching in large-etalon waveguides) possible, paving the way for
efficient, compact, and wide-bandwdith integrated nonlinear devices.",1701.05628v1
2017-01-24,Accelerated Magnetic Resonance Spectroscopy with Vandermonde Factorization,"Multi-dimensional magnetic resonance spectroscopy is an important tool for
studying molecular structures, interactions and dynamics in bio-engineering.
The data acquisition time, however, is relatively long and non-uniform sampling
can be applied to reduce this time. To obtain the full spectrum,a
reconstruction method with Vandermonde factorization is proposed.This method
explores the general signal property in magnetic resonance spectroscopy: Its
time domain signal is approximated by a sum of a few exponentials. Results on
synthetic and realistic data show that the new approach can achieve faithful
spectrum reconstruction and outperforms state-of-the-art low rank Hankel matrix
method.",1701.07017v1
2017-04-12,Propagation des singularités et résonances,"In the framework of semiclassical resonances, we make more precise the link
between polynomial estimates of the extension of the resolvent and propagation
of the singularities through the trapped set. This approach makes it possible
to eliminate infinity and to concentrate the study near the trapped set. It has
allowed us in previous papers to obtain the asymptotic of resonances in various
geometric situations.",1704.03798v1
2017-04-04,Gravity Induced Resonant Emission,"The gravitational drift of ions relative to the electrons induces two type of
waves in magnetized plasma; ion acoustic (IO) waves and lower hybrid (LH)
waves. The IO waves induced by the gravity are damped by electromagnetic (EM)
waves leads to the formation of LH waves. For higher wave vector, these LH wave
results in to the resonant absorption and re-emission of EM waves, called as
gravity induced resonant emission (gire). A general formula has been derived
for gire frequency is convergence of all fundamental quantities.",1704.07225v1
2017-04-27,From chiral NN(N) interactions to giant and pygmy resonances via extended RPA,"The properties of giant and pygmy resonances are calculated starting from
chiral two-and three-nucleon interactions. The aim is to assess the predictive
power of modern Hamiltonians and especially the role of the three-nucleon
force. Methods based on the random-phase approximation (RPA) provide an optimal
description of the modes of interest with minimal computational requirements.
Here we discuss the giant resonances (GRs) of 40,48Ca isotopes and their
low-energy dipole response. A comparison with previous results obtained with a
transformed Argonne V18 two-nucleon potential points to certain improvements.",1704.08429v1
2017-04-28,Transmission singularities in resonant electron tunneling through double complex potential barrier,"Tunneling of electrons through a barrier with complex potential is
investigated. We focus on two cases, symmetric double rectangular barrier and
double delta potential barrier, and give expressions for resonant transmission
probability for both cases. Expressions for reflection amplitude and absorption
are also obtained in the case of delta potential. It will be shown that for
given dimensions of the potential barrier and the real part of the potential,
resonant transmission probability approaches infinity for only one positive
value of the imaginary part of the potential.",1704.08890v1
2018-05-07,Resonant Spin Exchange between Heteronuclear Atoms Assisted by Periodic Driving,"We propose a general scheme for inducing resonant exchange between spins or
pseudo-spins of unmatched levels via periodic driving. The basic idea is
illustrated for a system of two heteronuclear atoms, for which analytical
results are provided for the effective spin exchange (SE) interaction strength.
It is then applied to the mixture of 23Na and 87Rb atoms with a radio-frequency
(rf) or microwave field near-resonant to the mismatched Zeeman level spacings.
SE interaction engineered this way is applicable to ultracold quantum gas
mixtures involving spinor Bose-Bose, Bose-Fermi, and Fermi-Fermi atoms.",1805.02310v1
2018-05-11,Tetraneutron: Rigorous continuum calculation,"The four-neutron system is studied using exact continuum equations for
transition operators and solving them in the momentum-space framework. A
resonant behavior is found for strongly enhanced interaction but not a the
physical strength, indicating the absence of an observable tetraneutron
resonance, in contrast to a number of earlier works. As the transition
operators acquire large values at low energies, it is conjectured that this
behavior may explain peaks in many-body reactions even without a resonance.",1805.04349v1
2008-06-30,Spin Collective Modes of Two-Species Fermi Liquids: Helium-3 and Atomic Gases near the Feshbach Resonance,"We present theoretical findings on the spin collective modes of a two-species
Fermi liquid, prepared alternatively in a polarized equilibrium or a polarized
non-equilibrium state. We explore the effects on these modes of a diverging
s-wave scattering length, as occurs near a Feshbach resonance in a Fermionic
atomic gas. We compare these atomic gas modes with those of the conventional
Helium-3 system, and we find that they differ from the conventional systems,
and that the gap and spin stiffness are tunable via the Feshbach resonance.",0807.0018v1
2008-07-03,Higher order terms in the geometric resonance of open orbits in unidirectional lateral superlattices,"The geometric resonance of open orbits in unidirectional lateral
superlattices has been examined with high magnetic-field resolution.
Magnetoresistance oscillations periodic in 1/B, analogous to the well-known
commensurability oscillations but orders of magnitude smaller both in magnitude
and in the magnetic-field scale, have been observed superposed on the low-field
positive magnetoresistance. The periodicity in 1/B can be interpreted in terms
of higher order resonances.",0807.0571v1
2008-07-15,Excited-state spectroscopy of single NV defects in diamond using optically detected magnetic resonance,"Using pulsed optically detected magnetic resonance techniques, we directly
probe electron-spin resonance transitions in the excited-state of single
Nitrogen-Vacancy color centers in diamond. Unambiguous assignment of excited
state fine structure is made, based on changes of NV defect photoluminescence
lifetime. This study provides significant insight into the structure of the
emitting 3E excited state, which is invaluable for the development of
diamond-based quantum information processing.",0807.2379v2
2008-07-16,Entropic Stochastic Resonance,"We present a novel scheme for the appearance of Stochastic Resonance when the
dynamics of a Brownian particle takes place in a confined medium. The presence
of uneven boundaries, giving rise to an entropic contribution to the potential,
may upon application of a periodic driving force result in an increase of the
spectral amplification at an optimum value of the ambient noise level. This
Entropic Stochastic Resonance (ESR), characteristic of small-scale systems, may
constitute a useful mechanism for the manipulation and control of
single-molecules and nano-devices.",0807.2558v1
2008-07-16,Low-loss Materials for high Q-factor Bragg Reflector Resonators,"A Bragg resonator uses dielectric plates within a metallic cavity to confine
the energy within a central free space region. The importance of the
permittivity is shown with a better Q-factor possible using higher permittivity
materials of larger intrinsic dielectric losses. This is because the electric
energy in the reflectors decreases proportionally to the square root of
permittivity and the coupling to the metallic losses decrease linearly. In a
sapphire resonator with a single reflector pair a Q-factor of 2.34x10^5 is
obtained, which may be improved on by up to a factor of 2 using higher
permittivity materials.",0807.2591v1
2008-07-21,New Narrow Nucleon N*(1685),"We argue that the existence of a new narrow (Gamma < 25 MeV) nucleon
resonance N*(1685) is strongly supported by recent data on eta photoproduction
off the nucleon. The resonance has much stronger photo-coupling to the neutron
than to the proton. This nucleon resonance is a good candidate for the
non-strange member of the exotic anti-decouplet of baryons -- the partner of
the pentaquark Theta+. All up to date known properties of new N*(1685) are
summarized.",0807.3217v2
2008-07-31,Engineering Superposition States and Tailored Probes for Nano-resonators Via Open-Loop Control,"We show that a nano-resonator can be prepared in mesoscopic-superposition
states merely by monitoring a qubit coupled to the square of the resonators
position. This works for thermal initial states, and does not require a
third-order nonlinearity. The required coupling can be generated using a simple
open-loop control protocol, obtained with optimal control theory. We simulate
the complete preparation process, including environmental noise. Our results
indicate the power of open-loop control for state-engineering and measurement
in quantum nano-systems.",0807.5132v2
2009-12-02,Dynamics of one-resonant biholomorphisms,"Our first main result is a construction of a simple formal normal form for
holomorphic diffeomorphisms in C^n whose differentials have one-dimensional
family of resonances in the first m eigenvalues, m <= n (but more resonances
are allowed for other eigenvalues). Next, we provide invariants and give
conditions for the existence of basins of attraction. Finally, we give
applications and examples demonstrating the sharpness of our conditions.",0912.0428v2
2009-12-06,High Order Momentum Modes by Resonant Superradiant Scattering,"The spatial and time evolutions of superradiant scattering are studied
theoretically for a weak pump beam with different frequency components
traveling along the long axis of an elongated Bose-Einstein condensate.
Resulting from the analysis for mode competition between the different resonant
channels and the local depletion of the spatial distribution in the
superradiant Rayleigh scattering, a new method of getting a large number of
high-order forward modes by resonant frequency components of the pump beam is
provided, which is beneficial to a lager momentum transfer in atom manipulation
for the atom interferometry and atomic optics.",0912.1088v1
2009-12-10,Collectivity-assisted ground state cooling of a nanomechanical resonator,"We discuss cooling of a nanomechanical resonator to its mechanical ground
state by coupling it to a collective system of two interacting flux qubits. We
find that the collectivity crucially improves cooling by two mechanisms. First,
cooling transitions proceed via sub-radiant Dicke states, and the reduced line
width of these sub-radiant states suppresses both the scattering and the
environmental contribution to the final phonon number. Second, detrimental
carrier excitations without change in the motion of the resonator are
suppressed by collective energy shifts.",0912.1990v1
2009-12-11,Magneto-optical Feshbach resonance: Controlling cold collision with quantum interference,"We propose a method of controlling two-atom interaction using both magnetic
and laser fields. We analyse the role of quantum interference between magnetic
and optical Feshbach resonances in controlling cold collision. In particular,
we demonstrate that this method allows us to suppress inelastic and enhance
elastic scattering cross sections. Quantum interference is shown to modify
significantly the threshold behaviour and resonant interaction of ultracold
atoms. Furthermore, we show that it is possible to manipulate not only the
spherically symmetric s-wave interaction but also the anisotropic higher
partial-wave interactions which are particularly important for high temperature
superfluid or superconducting phases of matter.",0912.2170v2
2009-12-18,Time scales in nuclear giant resonances,"We propose a general approach to characterise fluctuations of measured cross
sections of nuclear giant resonances. Simulated cross sections are obtained
from a particular, yet representative self-energy which contains all
information about fragmentations. Using a wavelet analysis, we demonstrate the
extraction of time scales of cascading decays into configurations of different
complexity of the resonance. We argue that the spreading widths of collective
excitations in nuclei are determined by the number of fragmentations as seen in
the power spectrum. An analytic treatment of the wavelet analysis using a
Fourier expansion of the cross section confirms this principle. A simple rule
for the relative life times of states associated with hierarchies of different
complexity is given.",0912.3594v1
2009-12-21,Coherent Population Trapping with Controlled Interparticle Interactions,"We investigate Coherent Population Trapping in a strongly interacting
ultracold Rydberg gas. Despite the strong van der Waals interactions and
interparticle correlations, we observe the persistence of a resonance with
subnatural linewidth at the single-particle resonance frequency as we tune the
interaction strength. This narrow resonance cannot be understood within a
meanfield description of the strong Rydberg--Rydberg interactions. Instead, a
many-body density matrix approach, accounting for the dynamics of interparticle
correlations, is shown to reproduce the observed spectral features.",0912.4099v2
2009-12-22,Spatial effects of Fano resonance in local tunneling conductivity in vicinity of impurity on semiconductor surface,"We present the results of local tunneling conductivity spatial distribution
detailed theoretical investigations in vicinity of impurity atom for a wide
range of applied bias voltage. We observed Fano resonance in tunneling
conductivity resulting from interference between resonant tunneling channel
through impurity energy level and direct tunneling channel between the
tunneling contact leads. We have found that interference between tunneling
channels strongly modifies form of tunneling conductivity measured by the
scanning tunneling microscopy/spectroscopy (STM/STS) depending on the distance
value from the impurity.",0912.4385v1
2011-11-02,Four-Lepton Resonance at the Large Hadron Collider,"A spin-1 weakly interacting vector boson, Z', is predicted by many new
physics theories. Searches at colliders for such a Z' resonance typically focus
on lepton-antilepton or top-antitop events. Here we present a novel channel
with a Z' resonance that decays to 4 leptons, but not to 2 leptons, and discuss
its possible discovery at the Large Hadron Collider. This baryonic gauge boson
is well motivated in a supersymmetry framework.",1111.0633v3
2011-11-05,Optical antennas as nanoscale resonators,"Recent progress in nanotechnology has enabled us to fabricate subwavelength
architectures that function as antennas for improving the exchange of optical
energy with nanoscale matter. We describe the main features of optical antennas
for enhancing quantum emitters and review designs that increase the spontaneous
emission rate by orders of magnitude from the ultraviolet up to the
near-infrared spectral range. To further explore how optical antennas may lead
to unprecedented regimes of light-matter interaction, we draw a relationship
between metal nanoparticles, radio-wave antennas and optical resonators. Our
analysis points out how optical antennas may function as nanoscale resonators
and how these may offer unique opportunities with respect to state-of-the-art
microcavities.",1111.1302v1
2011-11-14,Electron spin resonance study of anisotropic interactions in a two-dimensional spin gap magnet PHCC,"Fine details of the excitation spectrum of the two-dimensional spin-gap
magnet PHCC are revealed by electron spin resonance investigations. The values
of anisotropy parameters and the orientations of the anisotropy axes are
determined by accurate measurements of the angular, frequency-field and
temperature dependences of the resonance absorption. The properties of a
spin-gap magnet in the vicinity of critical field are discussed in terms of
sublevel splittings and g-factor anisotropy.",1111.3223v1
2011-11-15,Appropriate observables for investigating narrow resonances in kaon photoproduction off a proton,"The existence of non-strange partner of pentaquark, the J^p = 1/2^+ narrow
resonance, has been investigated by utilizing kaon photoproduction off a
proton. It is found that the corresponding mass is 1650 MeV and the appropriate
observables for investigating this resonance are the recoiled hyperon
polarization, the beam-recoil double polarization C_x, and differential cross
section at backward angles. Future kaon photoproduction experiments at low
energies should focus on these observables.",1111.3471v1
2011-11-17,Resonance instability of axially-symmetric magnetostatic equilibria,"We review the evidence for and against the possibility that a strong enough
poloidal field stabilizes an axisymmetric magnetostatic field configuration. We
show that there does exist a class of resonant MHD waves which produce
instability for any value of the ratio of poloidal and toroidal field strength.
We argue that recent investigations of the stability of mixed poloidal and
toroidal field configurations based on 3-d numerical simulations, can miss this
instability because of the very large azimuthal wave numbers involved and its
resonant character.",1111.4040v2
2011-11-18,Extraordinary transmission caused by symmetry breaking,"The terahertz transmission properties of symmetrical and asymmetrical annular
apertures arrays (AAAs) are investigated both experimentally and numerically.
It is found that only odd order resonant modes are observed for the symmetrical
structures but both odd and even order resonances can be shown for the
asymmetrical structures. Breaking the symmetry of AAAs by gradually displacing
the H-shaped AAAs to U-shaped AAAs allows an intensity modulation depth of 99%
of the second order resonance. Simulation results verify the experimental
conclusions well. This result provides a tremendous opportunity for terahertz
wavelength tunable filtering, sensing, and near-field imaging.",1111.4367v2
2011-11-22,Lock-in detection for pulsed electrically detected magnetic resonance,"We show that in pulsed electrically detected magnetic resonance (pEDMR)
signal modulation in combination with a lock-in detection scheme can reduce the
low-frequency noise level by one order of magnitude and in addition removes the
microwave-induced non-resonant background. This is exemplarily demonstrated for
spin-echo measurements in phosphorus-doped Silicon. The modulation of the
signal is achieved by cycling the phase of the projection pulse used in pEDMR
for the read-out of the spin state.",1111.5149v1
2011-11-22,Strong Coupling Optimization With Planar Spiral Resonators,"Planar spirals offer a highly scalable geometry appropriate for wireless
power transfer via strongly coupled inductive resonators. We numerically derive
a set of geometric scale and material independent coupling terms, and analyze a
simple model to identify design considerations for a variety of different
materials. We use our model to fabricate integrated planar resonators of
handheld sizes, and optimize them to achieve high Q factors, comparable to much
larger systems, and strong coupling over significant distances with
approximately constant efficiency.",1111.5271v1
2012-01-02,Scattering of unstable particles in a finite volume: the case of pi rho scattering and the a1(1260) resonance,"We present a way to evaluate the scattering of unstable particles quantized
in a finite volume with the aim of extracting physical observables for infinite
volume from lattice data. We illustrate the method with the $\pi\rho$
scattering which generates dynamically the axial-vector $a_1(1260)$ resonance.
Energy levels in a finite box are evaluated both considering the $\rho$ as a
stable and unstable resonance and we find significant differences between both
cases. We discuss how to solve the problem to get the physical scattering
amplitudes in the infinite volume, and hence phase shifts, from possible
lattice results on energy levels quantized inside a finite box.",1201.0438v1
2012-01-05,Heavy quark spin symmetry breaking in near-threshold $J^{PC}=1^{--}$ quarkonium-like resonances,"A mixing of near-threshold quarkonium-like resonances with heavy
meson-antimeson pairs results in an enhancement of heavy quark spin symmetry
breaking, since the meson pairs are not eigenstates of the heavy quark spin.
The decomposition of $P$-wave states of meson pairs in terms of the
heavy-quark-pair spin states is considered in the channel with $J^{PC}=1^{--}$,
which is directly produced in $e^+e^-$ annihilation. Specific processes are
suggested for experimental study of the effects of the mixing with heavy meson
pairs and of the internal spin structure of bottomonium and charmonium
resonances.",1201.1222v1
2012-01-04,Propagation characteristics of complementary split-ring resonators excited by internal cylindrical wave,"For a complementary split-ring resonators (CSRRs) etched on one screen of two
infinite and perfectly conducting plates under cylindrical plane wave
illumination, the transmission coefficients analysis were performed through
finite-difference time-domain simulations. For the single slot ring CSRR, two
transmission dips are observed for the direction parallel to aperture at
resonance whereas two enhanced transmission for the direction normal to the
aperture. For double slot ring CSRR, the transmission coefficients appear more
anisotropic. The results provided considerable insight into the electromagnetic
response of CSRR and would be very helpful for developing new electronic
devices such as filters.",1201.1254v2
2012-01-10,Optical Kerr Frequency Comb Generation in Overmoded Resonators,"We show that scattering-based interaction among nearly degenerate optical
modes is the key factor in low threshold generation of Kerr frequency combs in
nonlinear optical resonators possessing small group velocity dispersion (GVD).
The mode interaction is capable of producing drastic change in the local GVD,
resulting in either a significant reduction or increase of the oscillation
threshold. It is also responsible for the majority of observed combs in
resonators characterized with large normal GVD. We present results of our
numerical simulations as well as supporting experimental data.",1201.1959v1
2012-01-12,Negative frequency resonant radiation,"Optical solitons or soliton-like states shed light to blue-shifted
frequencies through a resonant emission process. We predict a mechanism by
which a second propagating mode is generated. This mode, called negative
resonant radiation originates from the coupling of the soliton mode to the
negative frequency branch of the dispersion relation. Measurements in both bulk
media and photonic crystal fibres confirm our predictions.",1201.2689v1
2012-01-18,Effects of pseudoscalar-baryon channels in the dynamically generated vector-baryon resonances,"We study the interaction of vector mesons with the octet of stable baryons in
the framework of the local hidden gauge formalism using a coupled channels
unitary approach, including also the pseudoscalar-baryon channels which couple
to the same quantum numbers. We examine the scattering amplitudes and their
poles, which can be associated to known $J^P=1/2^-,3/2^-$ baryon resonances,
and determine the role of the pseudoscalar-baryon channels, changing the width
and eventually the mass of the resonances generated with only the basis of
vector-baryon states.",1201.3756v1
2012-01-24,Bounds on R-parity Violation from Resonant Slepton Production at the LHC,"We consider the ATLAS and CMS searches for dijet resonances, as well as the
ATLAS search for like-sign dimuon pairs at the LHC with 7 TeV center of mass
energy. We interpret their exclusions in terms of bounds on the supersymmetric
R-parity violating parameter space. For this we focus on resonant slepton
production followed by the corresponding decay.",1201.5014v2
2012-01-25,Long-range resonant interactions in biological systems,"The issue of retarded long-range resonant interactions between two molecules
with oscillating dipole moments is reinvestigated within the framework of
classical electrodynamics. By taking advantage of a theorem in complex
analysis, we present a simple method to work out the frequencies of the normal
modes, which are then used to estimate the interaction potential. The main
results thus found are in perfect agreement with several outcomes obtained from
quantum computations. Moreover, when applied to a biophysical context, our
findings shed new light on Fr\""ohlich's theory of selective long-range
interactions between biomolecules. In particular, at variance with a
long-standing belief, we show that sizable resonant long-range interactions may
exist only if the interacting system is out of thermal equilibrium.",1201.5187v1
2012-01-25,Internal loss of superconducting resonators induced by interacting two level systems,"In a number of recent experiments with microwave high quality superconducting
coplanar waveguide (CPW) resonators an anomalously weak power dependence of the
quality factor has been observed. We argue that this observation implies that
the monochromatic radiation does not saturate the Two Level Systems (TLS)
located at the interface oxide surfaces of the resonator and suggests the
importance of their interactions. We estimate the microwave loss due to
interacting TLS and show that the interactions between TLS lead to a drift of
their energies that result in a much slower, logarithmic dependence of their
absorption on the radiation power in agreement with the data.",1201.5299v2
2012-01-25,Dispersive Estimates in R^3 with Threshold Resonances,"We prove dispersive estimates in R^3 for the Schroedinger evolution generated
by the Hamiltonian H = -\Delta+V, under optimal decay conditions on V, in the
presence of zero energy eigenfunctions and resonances.",1201.5331v2
2012-04-04,Extension of the Measurement Capabilities of the Quadrupole Resonator,"The Quadrupole Resonator, designed to measure the surface resistance of
superconducting samples at 400 MHz has been refurbished. The accuracy of its
RF-DC compensation measurement technique is tested by an independent method. It
is shown that the device enables also measurements at 800 and 1200 MHz and is
capable to probe the critical RF magnetic field. The electric and magnetic
field configuration of the Quadrupole Resonator are dependent on the excited
mode. It is shown how this can be used to distinguish between electric and
magnetic losses.",1204.1018v1
2012-04-16,High-Q silicon optomechanical microdisk resonators at gigahertz frequencies,"We report disk-shaped silicon optomechanical resonators with frequency up to
1.75 GHz in the ultrahigh frequency band. Optical transduction of the thermal
motion of the disks' in-plane vibrational modes yields a displacement
sensitivity of 4.1 \times 10^(-17) m/Hz^(1/2). Due to the reduced clamping
loss, these disk resonators possess high mechanical quality factors (Q), with
the highest value of 4370 for the 1.47 GHz mode measured in ambient air.
Numerical simulation on the modal frequency and mechanical Q for disks of
varying undercut shows modal coupling and suggests a realistic pedestal size to
achieve the highest possible Q.",1204.3605v1
2012-04-18,Integrated high frequency aluminum nitride optomechanical resonators,"Aluminum nitride (AlN) has been widely used in microeletromechanical
resonators for its excellent electromechanical properties. Here we demonstrate
the use of AlN as an optomechanical material that simultaneously offer low
optical and mechanical loss. Integrated AlN microring resonators in the shape
of suspended rings exhibit high optical quality factor (Q) with loaded Q up to
125,000. Optomechanical transduction of the Brownian motion of a GHz contour
mode yields a displacement sensitivity of 6.2\times10^(-18)m/Hz^(1/2) in
ambient air.",1204.4203v2
2012-04-19,Radiative Neutron Capture on Carbon-14 in Effective Field Theory,"The cross section for radiative capture of neutron on carbon-14 is calculated
using the model-independent formalism of halo effective field theory. The
dominant contribution from E1 transition is considered, and the cross section
is expressed in terms of elastic scattering parameters of the effective range
expansion. Contributions from both resonant and non-resonant interaction are
calculated. Significant interference between these leads to a capture
contribution that deviates from simple Breit-Wigner resonance form.",1204.4408v1
2013-09-02,Counting of discrete Rossby/drift wave resonant triads,"The purpose of this note is to remove the confusion about counting of
resonant wave triads for Rossby and drift waves in the context of the
Charney-Hasegawa-Mima equation. In particular, we aim to point out a major
error of over-counting of triads in the paper ""Discrete exact and
quasi-resonances of Rossby/drift waves on beta-plane with periodic boundary
conditions"", by Kartashov and Kartashova, arXiv:1307.8272v1 [physics.flu-dyn]
(2013).",1309.0405v1
2013-09-03,Lower bounds for resonance counting functions for Schrödinger operators with fixed sign potentials in even dimensions,"If the dimension $d$ is even, the resonances of the Schr\""odinger operator
$-\Delta +V$ on ${\mathbb R}^d$ with $V$ bounded and compactly supported are
points on $\Lambda$, the logarithmic cover of ${\mathbb C} \setminus \{0\}$. We
show that for fixed sign potentials $V$ and for nonzero integers $m$, the
resonance counting function for the $m$th sheet of $\Lambda$ has maximal order
of growth.",1309.0754v1
2013-09-05,Rayleigh scattering boosted multi-GHz displacement sensitivity in whispering gallery opto-mechanical resonators,"Finite photon lifetimes for light fields in an opto-mechanical cavity impose
a bandwidth limit on displacement sensing at mechanical resonance frequencies
beyond the loaded cavity photon decay rate. Opto-mechanical modulation
efficiency can be enhanced via multi-GHz transduction techniques such as
piezo-opto-mechanics at the cost of on-chip integration. In this paper, we
present a novel high bandwidth displacement sense scheme employing Rayleigh
scattering in photonic resonators. Using this technique in conjunction with
on-chip electrostatic drive in silicon enables efficient modulation at
frequencies up to 9.1GHz. Being independent of the drive mechanism, this scheme
could readily be extended to piezo-opto-mechanical and all optical transduced
systems.",1309.1481v1
2013-09-25,"Self-organization, Pattern Formation, Cavity Solitons and Rogue Waves in Singly Resonant Optical Parametric Oscillators","Spatio-temporal dynamics of singly resonant optical parametric oscillators
with external seeding displays hexagonal, roll and honeycomb patterns, optical
turbulence, rogue waves and cavity solitons. We derive appropriate mean-field
equations with a sinc$^2$ nonlinearity and demonstrate that off-resonance
seeding is necessary and responsible for the formation of complex spatial
structures via self-organization. We compare this model with those derived
close to the threshold of signal generation and find that back-conversion of
signal and idler photons is responsible for multiple regions of spatio-temporal
self-organization when increasing the power of the pump field.",1309.6543v1
2014-05-05,Long-time correlated quantum dynamics of phonon cooling,"We investigate the steady-state cooling dynamics of vibrational degrees of
freedom related to a nanomechanical oscillator coupled with a laser-pumped
quantum dot in an optical resonator. Correlations between phonon-cooling and
quantum-dot photon emission processes occur respectively when a photon laser
absorption together with a vibrational phonon absorption is followed by photon
emission in the optical resonator. Therefore, the detection of photons
generated in the cavity mode concomitantly contribute to phonon cooling
detection of the nanomechanical resonator.",1405.0903v1
2014-05-06,Theoretical study of the $Λ$(1520) photoproduction off proton target based on the new CLAS data,"Based on the high precision experimental data released by the CLAS
Collaboration recently, the interaction mechanism of the photoproduction of
$\Lambda$(1520) off a proton target is investigated within a
Regge-plus-resonance approach. With the decay amplitudes predicted in the
constituent quark model, the roles played by nucleon resonances are studied. It
is found that $N(2120)$ provides the most important contribution among the
nucleon resonances predicted in the constituent quark model. The $t$ channel
contribution with Regge trajectories and the $\Lambda$ intermediate $u$ channel
are responsible to the behaviors of the differential cross section at forward
and backward angles, respectively.",1405.1145v1
2014-05-06,Ionic Coulomb Blockade and Resonant Conduction in Biological Ion Channels,"The conduction and selectivity of calcium/sodium ion channels are described
in terms of ionic Coulomb blockade, a phenomenon based on charge discreteness
and an electrostatic model of an ion channel. This novel approach provides a
unified explanation of numerous observed and modelled conductance and
selectivity phenomena, including the anomalous mole fraction effect and
discrete conduction bands. Ionic Coulomb blockade and resonant conduction are
similar to electronic Coulomb blockade and resonant tunnelling in quantum dots.
The model is equally applicable to other nanopores.",1405.1391v1
2014-05-13,Two-Colour Free Electron Laser with Wide Frequency Separation using a Single Monoenergetic Electron Beam,"Studies of a broad bandwidth, two-colour FEL amplifier using one
monoenergetic electron beam are presented. The two-colour FEL interaction is
achieved using a series of undulator modules alternately tuned to two
well-separated resonant frequencies. Using the broad bandwidth FEL simulation
code Puffin, the electron beam is shown to bunch strongly and simultaneously at
the two resonant frequencies. Electron bunching components are also generated
at the sum and difference of the resonant frequencies.",1405.3144v2
2014-05-30,Eliminating Structural Loss in Optomechanical Resonators Using Elastic Wave Interference,"Optomechanical resonators suffer from the dissipation of mechanical energy
through the necessary anchors enabling the suspension of the structure. Here we
show that such structural loss in an optomechnaical oscillator can be almost
completely eliminated through the destructive interference of elastic waves
using dual-disk resonators. We also present both analytical and numerical model
that predicts the observed interference of elastic waves. Our experimental data
reveal unstressed SiN devices with mechanical Q-factors up to $10^4$ at
mechanical frequencies of $f=102$ MHz ($fQ = 10^{12}$) at room temperature.",1406.0029v1
2014-06-03,Improving Cooling performance of the mechanical resonator with the two-level-system defects,"We study cooling performance of a realistic mechanical resonator containing
defects. The normal cooling method through an optomechanical system does not
work efficiently due to those defects. We show by employing periodical
$\sigma_z$ pulses, we can eliminate the interaction between defects and their
surrounded heat baths up to the first order of time. Compared with the cooling
performance of no $\sigma_z$ pulses case, much better cooling results are
obtained. Moreover, this pulse sequence has an ability to improve the cooling
performance of the resonator with different defects energy gaps and different
defects damping rates.",1406.0555v1
2014-06-03,Frequency combs from crystalline resonators: influence of cavity parameters on comb dynamics,"We experimentally study the factors that influence the span in frequency
combs derived from the crystalline whispering gallery mode resonators. We
observe that cavity dispersion plays an important role in generation of combs
by cascaded four wave mixing process. We observed combs from the resonators
with anomalous dispersion and nearly zero dispersion at the pump wavelength. In
addition, the comb generation efficiency is found to be affected by the
crossing of modes of different families. The influence of Raman gain is
discussed as well as the role of cavity diameter and pump power. Copyright 2014
California Institute of Technology. Government sponsorship acknowledged.",1406.0790v1
2015-12-02,Resonant Anderson localization in segmented wires,"We discuss a model of random segmented wire, with linear segments of 2D wires
joined by circular bends. The joining vertices act as scatterers on the
propagating electron waves. The model leads to resonant Anderson localization
when all segments are of similar length. The resonant behavior is present with
one and also with several propagating modes. The probability distributions
evolve from diffusive to localized regimes when increasing the number of
segments in a similar way for long and short localization lengths. As a
function of the energy a finite segmented wire typically evolves from localized
to diffusive to ballistic behavior in each conductance plateau.",1512.00680v1
2015-11-04,The instability of Wilton ripples,"Wilton ripples are a type of periodic traveling wave solution of the full
water wave problem incorporating the effects of surface tension. They are
characterized by a resonance phenomenon that alters the order at which the
resonant harmonic mode enters in a perturbation expansion. We compute such
solutions using non-perturbative numerical methods and investigate their
stability by examining the spectrum of the water wave problem linearized about
the resonant traveling wave. Instabilities are observed that differ from any
previously found in the context of the water wave problem.",1512.01562v2
2015-12-08,Analysis of high quality superconducting resonators: consequences for TLS properties in amorphous oxides,"$1/f$ noise caused by microscopic Two-Level Systems (TLS) is known to be very
detrimental to the performance of superconducting quantum devices but the
nature of these TLS is still poorly understood. Recent experiments with
superconducting resonators indicates that interaction between TLS in the oxide
at the film-substrate interface is not negligible. Here we present data on the
loss and $1/f$ frequency noise from two different Nb resonators with and
without Pt capping and discuss what conclusions can be drawn regarding the
properties of TLS in amorphous oxides. We also estimate the concentration and
dipole moment of the TLS.",1512.02553v1
2015-12-10,Understanding the Nature of $Λ(1405)$ through Regge Physics,"It appears that there are two resonances with $J^P= 1/2^-$ quantum numbers in
the energy region near the $\Lambda(1405)$ hyperon. The nature of these states
is a topic of current debate. To provide further insight we use Regge
phenomenology to access how these two resonances fit the established hyperon
spectrum. We find that only one of these resonances is compatible with a
three-quark state.",1512.03136v2
2015-12-10,Resonant plasmon-phonon coupling and its role in magneto-thermoelectricity in bismuth,"Using diagrammatic methods we derive an effective interaction between a low
energy collective movement of fermionic liquid (acoustic plasmon) and acoustic
phonon. We show that the coupling between the plasmon and the lattice has a
very non-trivial, resonant structure. When real and imaginary parts of the
acoustic plasmon's velocity are of the same order as the phonon's velocity, the
resonance qualitatively changes the nature of phonon-drag. In the following we
study how magneto-thermoelectric properties are affected. Our result suggests
that the novel mechanism of energy transfer between electron liquid and crystal
lattice can be behind the huge Nernst effect in bismuth.",1512.03283v1
2015-12-13,"$B^0 \to D^0 \bar D^0 K^0$, $B^+ \to D^0 \bar D^0 K^+$ and the scalar $D \bar D$ bound state","We study the $B^0$ decay to $D^0 \bar D^0 K^0$ based on the chiral unitary
model that generates the X(3720) resonance, and make predictions for the $D^0
\bar D^0$ invariant mass distribution. From the shape of the distribution, the
existence of the resonance below threshold could be induced. We also predict
the rate of production of the X(3720) resonance to the $D^0 \bar D^0$ mass
distribution with no free parameters.",1512.04048v1
2015-12-22,Coherence-resonance chimeras in a network of excitable elements,"We demonstrate that chimera behavior can be observed in nonlocally coupled
networks of excitable systems in the presence of noise. This phenomenon is
distinct from classical chimeras, which occur in deterministic oscillatory
systems, and it combines temporal features of coherence resonance, i.e., the
constructive role of noise, and spatial properties of chimera states, i.e.,
coexistence of spatially coherent and incoherent domains in a network of
identical elements. Coherence-resonance chimeras are associated with
alternating switching of the location of coherent and incoherent domains, which
might be relevant in neuronal networks.",1512.07036v2
2015-12-29,Gravitational Gamma Spectrometer for Studying the Gamma Resonance of the Long-Lived Isomer 103mRh,"The principle of operation and the construction are described of the
gravitational gamma spectrometer to study the gamma resonance of the long-lived
isomer $^{103m}$Rh. This is a table-top device which measures the form of gamma
resonance by the dependence of counting rate of gamma-rays in collimated beams
on the angle of their inclination with respect of the horizontal plane. Methods
of fabrication of gamma-sources for this device are considered.",1512.08576v1
2015-12-30,Features of electromagnetic waves in a complex plasma due to surface plasmon resonances on macroparticles,"The dielectric properties of complex plasma containing either metal or
dielectric spherical inclusions (macroparticles, dust) are investigated. We
focus on surface plasmon resonances on the macroparticle surfaces and their
effect on electromagnetic wave propagation. It is demonstrated that the
presence of surface plasmon oscillations significantly modifies plasma
electromagnetic properties by resonances and cutoffs in the effective
permittivity. This leads to related branches of electromagnetic waves and to
the wave band gaps. The results are discussed in the context of dusty plasma
experiments.",1512.09124v1
2016-05-10,Magnetic-field-mediated coupling and control in hybrid atomic-nanomechanical systems,"Magnetically coupled hybrid quantum systems enable robust quantum state
control through Landau-Zener transitions. Here, we show that an ultracold
atomic sample coupled to a nanomechanical resonator via oscillating magnetic
fields can be used to cool the resonator's mechanical motion, to measure the
mechanical temperature, and to enable entanglement of these mesoscopic objects.
We calculate the expected coupling for both permanent-magnet and
current-conducting nanostring resonators and describe how this hybridization is
attainable using recently developed fabrication techniques, including SiN
nanostrings and atom chips.",1605.03126v1
2016-05-19,Magneto-Optical Activity in High Index Dielectric Nanoantennas,"The magneto-optical activity, namely the polarization conversion capabilities
of high-index, non-absorbing, core-shell dielectric nanospheres is
theoretically analyzed. We show that, in analogy with their plasmonic
counterparts, the polarization conversion in resonant dielectric particles is
linked to the amount of electromagnetic field probing the magneto-optical
material in the system. However, in strong contrast with plasmon nanoparticles,
due to the peculiar distribution of the internal fields in resonant dielectric
spheres, the magneto-optical response is fully governed by the magnetic
(dipolar and quadrupolar) resonances with little effect of the electric ones.",1605.05879v1
2016-05-21,Propagators of resonances and rescatterings of the decay products,"Hadronic resonance propagators which take into account the analytical
properties of decay processes are built in terms of the dispersion relation
technique. Such propagators can describe multi-component systems, for example,
those when quark degrees of freedom create a resonance state, and decay
products correct the corresponding pole by adding hadronic deuteron-like
components. Meson and baryon states are considered, examples of particles with
different spins are presented.",1605.06605v2
2016-05-24,High bandwidth on-chip capacitive tuning of microtoroid resonators,"We report on the design, fabrication and characterization of silica
microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes
patterned onto the microtoroid resonators allow for rapid capacitive tuning of
the optical whispering gallery mode resonances while maintaining their
ultrahigh quality factor, enabling applications such as efficient radio to
optical frequency conversion, optical routing and switching applications.",1605.07281v1
2016-05-27,Classical and quantum resonances for hyperbolic surfaces,"For compact and for convex co-compact oriented hyperbolic surfaces, we prove
an explicit correspondence between classical Ruelle resonant states and quantum
resonant states, except at negative integers where the correspondence involves
holomorphic sections of line bundles.",1605.08801v3
2016-08-07,Spin-orbit coupling in Fe-based superconductors,"We study the spin resonance peak in recently discovered iron-based
superconductors. The resonance peak observed in inelastic neutron scattering
experiments agrees well with predicted results for the extended $s$-wave
($s_\pm$) gap symmetry. Recent neutron scattering measurements show that there
is a disparity between longitudinal and transverse components of the dynamical
spin susceptibility. Such breaking of the spin-rotational invariance in the
spin-liquid phase can occur due to spin-orbit coupling. We study the role of
the spin-orbit interaction in the multiorbital model for Fe-pnictides and show
how it affects the spin resonance feature.",1608.02230v1
2016-08-18,Locating resonances on hyperbolic cones,"In this note we explicitly compute the resonances on hyperbolic cones. These
are hyperbolic manifolds with a conic singularity equipped with a warped
product metric. The calculation is based on separation of variables and
Kummer's connection formulae for hypergeometric functions. To our knowledge
this is the one of the few explicit calculations of resonances that does not
rely on the resolvent being a two-point function.",1608.05278v3
2016-08-19,Exploring the extended scalar sector with resonances in vector boson scattering,"We show that the study of scalar resonances at various vector boson
scattering processes at the Large Hadron Collider can serve as a useful tool to
distinguish between different extensions of the scalar sector of the Standard
Model. The recent measurement of the Higgs boson properties leaves enough room
for the extended scalar sectors to be relevant for such studies. The shape of
the resonances, being model dependent, can shed light on the viable parameter
space of a number of theoretical models.",1608.05673v2
2016-08-31,Controlling mode competition by tailoring the spatial pump distribution in a laser: A resonance-based approach,"We introduce a simplified version of the steady-state ab initio laser theory
for calculating the effects of mode competition in continuous wave lasers using
the passive cavity resonances. This new theory harnesses widely available
numerical methods that can efficiently calculate the passive cavity resonances,
with negligible additional computational overhead. Using this theory, we
demonstrate that the pump profile of the laser cavity can be optimized both for
highly multi-mode and single-mode emission. An open source implementation of
this method has been made available.",1608.08985v1
2016-12-03,Ultralight scalars and resonances in black-hole physics,"Ultralight degrees of freedom coupled to matter lead to resonances, which can
be excited when the Compton wavelength of the field equals a dynamical scale in
the problem. For binaries composed of a star orbiting a supermassive black
hole, these resonances lead to a smoking-gun effect: a periastron distance
which {\it stalls}, even in the presence of gravitational-wave dissipation.
This effect, also called a {\it floating orbit}, occurs for generic equatorial
but eccentric orbits and we argue that finite-size effects are not enough to
suppress it.",1612.00978v2
2016-12-07,All-optical photonic band control in a quantum metamaterial,"Metamaterials made of periodic collections of dielectric nanorods are
considered theoretically. When quantum resonators are embedded within the
nanorods, one obtains a quantum metamaterial, whose electromagnetic properties
depend upon the state of the quantum resonators. The theoretical model predicts
that when the resonators are pumped and reach the inversion regime, the quantum
metamaterial exhibits an all-optical switchable conduction band. The phenomenon
can be described by considering the pole stucture of the scattering matrix of
the metamaterial.",1612.02263v1
2016-12-08,Formation and stimulated photodissociation of metastable molecules with emission of photon at the collision of two atoms in a laser radiation field,"The Formation of metastable molecules (Feshbach resonances) at the collision
of two atoms and subsequent stimulated transition to a lower unbound electronic
molecular state, with emission of a photon of the laser radiation has been
investigated. This can develop, in particular, for $Rb_2$ molecules due to
resonance scattering of two $Rb$ atoms. The considered process is a basis for
the creation of excimer lasers. Expressions for the cross sections of elastic
and inelastic resonance scattering and the intensity of the stimulated emission
of the photons have been obtained.",1612.02566v1
2016-12-13,Two-body relaxation of spin-polarized fermions in reduced dimensionalities near a p-wave Feshbach resonance,"We study inelastic two-body relaxation in a spin-polarized ultracold Fermi
gas in the presence of a p-wave Feshbach resonance. It is shown that in reduced
dimensionalities, especially in the quasi-one-dimensional case, the enhancement
of the inelastic rate constant on approach to the resonance is strongly
suppressed compared to three dimensions. This may open promising paths for
obtaining novel many-body states.",1612.04107v3
2016-12-13,High-Q mid-infrared chalcogenide glass resonators,"In this letter, we fabricated and characterized chalcogenide glass resonators
monolithically integrated on mid-infrared transparent CaF2 substrates. The
devices feature an intrinsic Q-factor of 4E5 at 5.2 micron wavelength, which
represents the highest Q-factor reported in planar mid-infrared resonators. It
is found that moisture can significantly impact the device performance when the
device was exposed to an ambient environment, although the high-Q
characteristics can be restored after undergoing an annealing treatment. Using
these devices, we further demonstrated on-chip cavity-enhanced spectroscopy to
quantify mid-IR absorption of ethanol solutions around 5.2 micron wavelength.",1612.04322v2
2016-12-20,Photoinduced molecular chirality probed by ultrafast resonant X-ray spectroscopy,"Recently developed circularly polarized X-ray light sources can probe
ultrafast chiral electronic and nuclear dynamics through spatially localized
resonant core transitions. We present simulations of time-resolved circular
dichroism (TRCD) signals given by the difference of left and right circularly
polarized X-ray probe transmission following an excitation by a circularly
polarized optical pump with variable time delay. Application is made to
formamide which is achiral in the ground state and assumes two chiral
geometries upon optical excitation to the first valence excited state. Probes
resonant with various K-edges (C, N and O) provide different local windows onto
the parity breaking geometry change thus revealing enantiomer asymmetry.",1612.06909v1
2017-06-23,Stark resonance parameters for the $3a_{1}$ orbital of the water molecule,"The Stark resonance parameters for the $3a_{1}$ molecular orbital of H$_{2}$O
are computed by solving a system of partial differential equations in spherical
polar coordinates. The starting point of the calculation is the quantum
potential derived for this orbital from a single-center expanded Hartree-Fock
orbital. The resonance positions and widths are obtained after applying an
exterior complex scaling technique to describe the ionization regime for
external fields applied along the two distinct $\hat{z}$ directions associated
with the symmetry axis. The procedure thus avoids the computation of
multi-center integrals, yet takes into account the geometric shape of a
simplified molecular orbital in the field-free case.",1706.07771v1
2017-07-05,Resonances under Rank One Perturbations,"We study resonances generated by rank one perturbations of selfadjoint
operators with eigenvalues embedded in the continuous spectrum. Instability of
these eigenvalues is analyzed and almost exponential decay for the associated
resonant states is exhibited. We show how these results can be applied to
Sturm-Liouville operators. Main tools are the Aronszajn-Donoghue theory for
rank one perturbations, a reduction process of the resolvent based on
Feshbach-Livsic formula, the Fermi golden rule and a careful analysis of the
Fourier transform of quasi-Lorentzian functions. We relate these results to
sojourn time estimates and spectral concentration phenomena",1707.01597v1
2017-07-07,Enhanced output entanglement with reservoir engineering,"We study the output entanglement in a three-mode optomechanical system via
reservoir engineering by shifting the center frequency of filter function away
from resonant frequency. We find the bandwidth of the filter function can
suppress the entanglement in the vicinity of resonant frequency of the system,
while the entanglement will become prosperous if the center frequency departs
from the resonant frequency. We obtain the approximate analytical expressions
of the output entanglement, and from which we give the optimal center frequency
at which the entanglement takes the maximum. Furthermore, we study the effects
of time delay between the two output fields on the output entanglement, and
obtain the optimal time delay for the case of large filter bandwidth.",1707.02228v1
2017-07-14,Multistability and coexisting soliton combs in ring resonators: the Lugiato-Lefever approach,"We are reporting that the Lugiato-Lefever equation describing the frequency
comb generation in ring resonators with the localized pump and loss terms also
describes the simultaneous nonlinear resonances leading to the multistability
of nonlinear modes and coexisting solitons that are associated with the
spectrally distinct frequency combs.",1707.04430v1
2017-07-27,Schumann resonance transients and the search for gravitational waves,"Schumann resonance transients which propagate around the globe can
potentially generate a correlated background in widely separated gravitational
wave detectors. We show that due to the distribution of lightning hotspots
around the globe these transients have characteristic time lags, and this
feature can be useful to further suppress such a background, especially in
searches of the stochastic gravitational-wave background. A brief review of the
corresponding literature on Schumann resonances and lightnings is also given.",1707.09047v2
2017-07-28,Three-dimensional cavity-assisted spontaneous emission as a single-photon source: two cavity modes and Rabi resonance,"Within the framework of exact quantum electrodynamics in dispersing and
absorbing media, we have studied the emission from an initially in the upper
state prepared emitter in a high quality cavity in the case, when there are two
cavity modes that resonantly interact with the emitter. In particular, when one
of the modes is in resonance with the emitter transition and the other mode is
tuned to the frequency equal to the Rabi splitting of the first mode, the
effect of Rabi resonance is observed.",1707.09146v2
2017-10-01,Cavity Induced Tunable Extraordinary Transmission: A Unique Way of Funneling Light through Subwavelength Apertures,"Extraordinary transmission through subwavelength metallic apertures has been
extensively studied and demonstrated. At resonance, the coupling between
surface plasmons on both surfaces of the metallic film tunnels the photon from
the one side to the other through the subwavelength aperture with small
transmission efficiency based on the metals dielectric parameters and aperture
geometrical dimensions. Here, we report a completely different form of
extraordinary transmission, where the two subwavelength complementary apertures
when coupled with an optical cavity induce about 100% extraordinary
transmission far away from the natural plasmon resonance of the constituent
metallic apertures. Such unique cavity phase driven plasmon resonance enables
tuning of the extraordinary transmission band across wide spectral range unlike
previously reported geometry driven extraordinary transmission.",1710.00392v1
2017-09-22,Micromechanical microphone using sideband modulation of nonlinear resonators,"We report the successful detection of an audio signal via sideband modulation
of a nonlinear piezoelectric micromechanical resonator. The
270$\times$96-$\mu$m resonator was shown to be reliable in audio detection for
sound intensity levels as low as ambient room noise and to have an unamplified
sensitivity of 23.9 $\mu$V/Pa. Such an approach may be adapted in acoustic
sensors and microphones for consumer electronics or medical equipment such as
hearing aids.",1710.00666v1
2017-10-02,Polaronic and dressed molecular states in orbital Feshbach resonances,"We consider the impurity problem in an orbital Feshbach resonance (OFR), with
a single excited clock state $|e\uparrow\rangle$ atom immersed in a Fermi sea
of electronic ground state $|g\downarrow\rangle$. We calculate the polaron
effective mass and quasi-particle residue, as well as the polaron to molecule
transition. By including one particle-hole excitation in the molecular state,
we find significant correction to the transition point. This transition point
moves toward the BCS side for increasing particle densities, which suggests
that the corresponding many-body physics is similar to a narrow resonance.",1710.00785v2
2017-10-24,Cooperative parametric resonance of the spin one half system of the dense atomic gas,"The cooperative resonance for a spin one half system interacting with dc and
ac magnetic field is considered. This interaction in the system collective
regime can result in parametic resonance and rapid excitation of the excited
spin state of the dense atomic gas. The phenomenon is studied using the density
matrix approach. We discuss the implementation of this effect and possible
applications of the quantum amplification by superradiant emission of
radiation.",1710.08877v1
2017-12-08,On-chip self-sensing enhancing actuation for MEMS/NEMS with large efficiency,"The implementation of on-chip MEMS/NEMS transducers for arbitrary resonators
is difficult due to a number of difficulties such as material choice, large
dissipation, restriction in high frequency, low sensitivity, poor reliability,
and poor integrability. We show a universal on-chip transduction scheme, which
can be adapted to any MEMS/NEMS resonator. We achieve all electrical, on-chip
MEMS/NEMS for any resonator.",1712.02918v3
2017-12-14,On the spreading width of the Isobaric Analog Resonances,"A description of the spreading width of the Isobaric Analog Resonances in
medium-heavy mass spherical nuclei is proposed within a combined approach. This
latter consists in incorporating the ""Coulomb description"" of isospin-forbidden
processes into the newly developed particle-hole dispersive optical model.
Within this approach, the observed spreading width of the resonances based on
the 208,209Pb parent-nuclei ground state is quantitatively estimated without
the use of specific adjustable parameters.",1712.05146v1
2017-12-15,Approximate controllability of the Jaynes-Cummings dynamics,"We investigate the controllability of the Jaynes-Cummings dynamics in the
resonant and nearly resonant regime. We analyze two different types of control
operators acting on the bosonic part, corresponding - in the application to
cavity QED - to an external electric and magnetic field, respectively. We prove
approximate controllability for these models, for all values of the coupling
constant g except those in a countable set S which is explicitly characterized
in the statement. The proof relies on a spectral analysis which yields the
non-resonance of the spectrum for every real g which is not in S.",1712.05666v1
2017-12-17,Connectivity dependence of Fano resonances in single molecules,"Using a first principles approach combined with analysis of heuristic
tight-binding models, we examine the connectivity dependence of two forms of
quantum interference in single molecules. Based on general arguments, Fano
resonances are shown to be insensitive to connectivity, while Mach-Zehnder-type
interference features are shown to be connectivity dependent. This behaviour is
found to occur in molecular wires containing anthraquinone units, in which the
pendant carbonyl groups create Fano resonances, which coexist with
multiple-path quantum interference features.",1712.06184v1
2017-12-28,Superluminal plasmons with resonant gain in population inverted bilayer graphene,"AB-stacked bilayer graphene with a tunable electronic bandgap in excess of
the optical phonon energy presents an interesting active medium, and we
consider such theoretical possibility in this work. We argue the possibility of
a highly resonant optical gain in the vicinity of the asymmetry gap. Associated
with this resonant gain are strongly amplified plasmons, plasmons with negative
group velocity and superluminal effects, as well as directional leaky modes.",1712.09924v1
2018-01-07,$η$ and $η'$ photoproduction with EtaMAID including Regge phenomenology,"We present a new version of the EtaMAID model for $\eta$ and $\eta'$
photoproduction on nucleons. The model includes 23 nucleon resonances
parameterized with Breit-Wigner shapes. The background is described by vector
and axial-vector meson exchanges in the $t$ channel using the Regge cut
phenomenology. Parameters of the resonances were obtained from a fit to
available experimental data for $\eta$ and $\eta'$ photoproduction on protons
and neutrons. The nature of the most interesting observations in the data is
discussed.",1801.02196v1
2018-01-13,Searches for vector-like quarks and resonances decaying to top quarks with the ATLAS and CMS detectors,"Many models beyond the standard model predict the existence of vector-like
quarks or other types of heavy resonances. Using proton-proton collision data
at center-of-mass energies of 8 and 13 TeV, the ATLAS and CMS Collaborations
have performed a multitude of searches for pair and singly produced vector-like
quarks decaying to W, Z, or Higgs bosons. Heavy gauge and (pseudo)scalar
resonances decaying to top quarks have been searched for as well. No evidence
for any of these hypothetical particles has been found yet, and stringent
exclusion limits are derived on their masses, cross sections and couplings in
various models.",1801.04417v1
2018-01-26,"Resonant-state expansion for open optical systems: Generalization to magnetic, chiral, and bi-anisotropic materials","The resonant-state expansion, a recently developed powerful method in
electrodynamics, is generalized here for open optical systems containing
magnetic, chiral, or bi-anisotropic materials. It is shown that the key matrix
eigenvalue equation of the method remains the same, but the matrix elements of
the perturbation now contain variations of the permittivity, permeability, and
bi-anisotropy tensors. A general normalization of resonant states in terms of
the electric and magnetic fields is presented.",1801.08883v1
2018-01-26,Linear build-up of Fano resonance spectral profiles,"The build-up dynamics of a continuous spectrum under the action of a weak
laser field on a Fano resonance with the use of the pulses with the Lorentz
spectrum and ultrashort pulses in the wavelet form is investigated. A
dispersion-time excitation dependence of the Fano resonances in a He atom, in
an InP impurity semiconductor, in longitudinal optical LO-phonons of a shallow
donor exciton in pure ZnO crystals, and in metamaterials are calculated. The
numerical simulation of the dynamics has shown time-dependent formation a Fano
spectral profile in the systems of different physical natures under the action
of ultrashort pulses with attosecond and femtosecond durations.",1801.08891v1
2018-09-03,State resolved investigation of Förster resonant energy transfer in collisions between polar molecules and Rydberg atoms,"We perform a comprehensive investigation of F\""orster resonant energy
transfer in a room-temperature thermal mixture of ammonia molecules and
rubidium Rydberg atoms. Fully state-resolved measurement of the Rydberg-atom
populations is achieved by combining millimeter-wave state transfer with
state-selective field ionization. This allows aspects of the energy transfer
process such as state dependence, ammonia pressure dependence, and dependence
on the energy resonance condition to be investigated in detail. Our results
pave the way for future quantum experiments combining polar molecules and
Rydberg atoms.",1809.00624v1
2018-09-06,Poincaré duality and resonance varieties,"We explore the constraints imposed by Poincar\'e duality on the resonance
varieties of a graded algebra. For a 3-dimensional Poincar\'e duality algebra
$A$, we obtain a fairly precise geometric description of the resonance
varieties $\mathcal{R}^i_k(A)$.",1809.01801v3
2018-09-07,Nuclear spin pumping by pulling effect,"The nuclear-to-electron spin angular momentum conversion via hyperfine
coupling in a normal metal (NM)/ferromagnet (FM) bilayer system is
theoretically investigated by using the nonequilibrium Green's function method.
The spin current generated by the nuclear magnetic resonance (NMR) is found to
be enhanced by the pulling effect in the FM when the temperature is lower than
NMR resonance frequency. In a Co/Pt bilayer system, we show that the spin
current by NMR becomes larger than that of the ferromagnetic resonance (FMR).",1809.02272v1
2018-09-19,Hidden-Beauty Broad Resonance $Y_b(10890)$ in Thermal QCD,"In this work, the mass and pole residue of resonance $Y_b$ is studied by
using QCD sum rules approach at finite temperature. Resonance $Y_b$ is
described by a diquark-antidiquark tetraquark current, and contributions to
operator product expansion are calculated by including QCD condensates up to
dimension six. Temperature dependences of the mass $m_{Y_b}$ and the pole
residue $\lambda_{Y_b}$ are investigated. It is seen that near a critical
temperature $(T_c\simeq190~\mathrm{MeV})$, the values of $m_{Y_b}$ and
$\lambda_{Y_b}$ are decreased to $87\%$, and to $44\%$ of their values at
vacuum.",1809.07213v1
2018-09-20,Majorana Qubit Readout Using Longitudinal Qubit-Resonator Interaction,"We propose a quantum non-demolition Majorana qubit readout protocol based on
parametricmodulation of a longitudinal interaction between a pair of Majorana
bound states and a resonator. The interaction can be modulated through
microwave frequency gate-voltage or flux control of a tunable tunnel barrier.
The qubit-resonator coupling is quantum non-demolition to exponential accuracy,
a property inherited from the topological nature of the Majorana zero modes.
The same mechanism as used for single-qubit readout can also be extended to
perform multi-qubit measurements and be used to enact long range entangling
gates.",1809.07776v2
2018-09-20,Emission of intense resonant radiation by dispersion-managed Kerr cavity solitons,"We report on an experimental and numerical study of temporal Kerr cavity
soliton dynamics in dispersion-managed fiber ring resonators. We find that
dispersion management can significantly magnify the Kelly-like resonant
radiation sidebands emitted by the solitons. Because of the underlying
phase-matching conditions, the sideband amplitudes tend to increase with
increasing pump-cavity detuning, ultimately limiting the range of detunings
over which the solitons can exist. Our experimental findings show excellent
agreement with numerical simulations.",1809.07886v1
2018-09-24,Superefficient cascade multiresonator quantum memory,"We propose a cascade scheme of a superefficient broadband quantum memory
consisting of four high-Q ring resonators forming a controllable frequency comb
and interacting with long-lived spin systems and with a common waveguide. Using
the transfer function giving extended matching conditions, the optimization of
all spectroscopic parameters of the system for quantum memory in the resonator
is carried out. It was shown that our quantum memory scheme does not impose
large restrictions on the parameters of losses in resonators and allows to
achieve super high efficiency 99.99 % in a wide frequency range.",1809.08759v2
2018-09-26,Left-handed Band in an Electromagnetic Metamaterial Inducedby Sub-wavelength Multiple Scattering,"Due to the deep sub-wavelength unit cell in metamaterials, the quasi-static
approximation is usually employed to describe the propagation. By making pairs
of resonators, we highlight that multiple scattering also occurs at this scale
and results in the existence of a dipolar resonance, which leads to a negative
index of refraction when we consider several resonators. We experimentally
verify the possibility of obtaining a negative index of refraction in periodic
metamaterials in two different ways, and eventually demonstrates a superlensing
effect in both cases.",1809.10558v1
2018-10-04,Propagation of Nonlinear Acoustic Waves in the Suspension of Ultrasound Contrast Agents Part I: Equation for Counting Resonance Effects and Revealing Acoustic Localization,"The oscillations of ultrasound contrast agents are of particular importance
to the understanding of the propagation of acoustic waves in the bubbly liquids
(suspensions of ultrasound contrast agents). Acoustic waves propagating in
bubbly liquids have been investigated extensively. Little has been dedicated to
the resonance effects of the microbubbles on the propagating waves. Here a
nonlinear partial differential equation for describing one-dimensional acoustic
waves propagating near the resonance frequency of the microbubbles in bubbly
liquids is obtained. The present equation recovers classical results for
propagating acoustic waves with finite amplitudes in liquids and interprets the
acoustic localization in bubbly liquids explicitly.",1810.02063v1
2018-10-05,Spin gap in a quasi-1D S=1/2 antiferromagnet K2CuSO4Cl2,"Electron spin resonance experiments in the quasi-1D S=1/2 antiferromagnet
K$_2$CuSO$_4$Cl$_2$ reveal opening of a gap in absence of magnetic ordering, as
well as an anisotropic shift of the resonance magnetic field. These features of
magnetic excitation spectrum are explained by a crossover between a gapped
spinon-type doublet ESR formed in a 1D antiferromagnet with uniform
Dzyaloshinskii-Moriya interaction and a Larmor-type resonance of a quasi-1D
Heisenberg system",1810.02675v2
2018-10-16,The resonant structure of Kink-Solitons in the Modified KP Equation,"Using the Wronskian representation of $\tau$-function, one can investigate
the resonant structure of kink-soliton and line-soliton of the modified KP
equation. It is found that the resonant structure of the the soliton graph is
obtained by superimposition of the two corresponding soliton graphs of the two
Le-Diagrams given an irreducible Schubert cell in a totally non-negative
Grassmannian $Gr(N,M)_{ \geq 0}$. Several examples are given.",1810.06962v1
2018-10-23,Perfect absorption of water waves by linear or nonlinear critical coupling,"We report on experiments of perfect absorption for surface gravity waves
impinging a wall structured by a subwavelength resonator. By tuning the
geometry of the resonator, a balance is achieved between the radiation damping
and the intrinsic viscous damping, resulting in perfect absorption by critical
coupling. Besides, it is shown that the resistance of the resonator, hence the
intrinsic damping, can be controlled by the wave amplitude, which provides a
way for perfect absorption tuned by nonlinear mechanisms. The perfect absorber
that we propose, without moving parts or added material, is simple, robust and
it presents a deeply subwavelength ratio wavelength/size $\simeq 18$.",1810.09884v1
2018-10-25,Electron dynamics in laser and quasi-static transverse electric and longitudinal magnetic fields,"By deriving the 3/2 dimensional Hamiltonian equations for electrons in the
intense laser radiation and quasi-static transverse electric and longitudinal
magnetic fields, the electron heating mechanisms are examined both for low
harmonic resonance of electron frequency in the static fields with the laser
frequency and for high harmonic resonances where the overlapping of broadened
resonances causes the stochastic heating. For both cases, the maximum electron
kinetic energies, well beyond the ponderomotive scaling, depend only on a small
parameter combining the laser amplitude, electrostatic field strength and the
conserved dephasing rate.",1810.10670v3
2018-10-25,Perturbation of the scattering resonances of an open cavity by small particles. Part I: The transverse magnetic polarization case,"This paper aims at providing a small-volume expansion framework for the
scattering resonances of an open cavity perturbed by small particles. The
induced shift of the scattering frequencies by the small particles is derived
without neglecting the radiation effect. The formula holds for arbitrary-shaped
particles. It shows a strong enhancement in the frequency shift in the case of
plasmonic particles. The formula is used to image small particles located near
the boundary of an open resonator which admits whispering-gallery modes.
Numerical examples of interest for applications are presented.",1810.10772v1
2018-10-27,Calculations of Neutron Reflectivity in the eV Energy Range from Mirrors made of Heavy Nuclei with Neutron-Nucleus Resonances,"We evaluate the reflectivity of neutron mirrors composed of certain heavy
nuclei which possess strong neutron-nucleus resonances in the eV energy range.
We show that the reflectivity of such a mirror for some nuclei can in principle
be high enough near energies corresponding to compound neutron-nucleus
resonances to be of interest for certain scientific applications in
non-destructive evaluation of subsurface material composition and in the theory
of neutron optics beyond the kinematic limit.",1810.11590v1
2018-10-27,Graphene-based Tunable Dual-Band Absorbers by Ribbon/Disk Array,"This article presents two dual-band absorbers based on graphene one
dimensional (1D) / two dimensional (2D) patterned arrays in the THz
frequencies. In comparison to the previous work, the structure of the proposed
device is very simple. Most dual-band absorbers are based on mixing resonances
of resonators with different sizes inside the structure. In this paper, the
proposed absorber is based on the arrays of one element. Dual
capacitive-inductive nature of the graphene patterned array and the impedance
matching condition are used to achieve two resonance bands with perfect
absorption by adjusting the graphene properties.",1810.11600v1
2019-06-05,Modal analysis for nanoplasmonics with nonlocal material properties,"Plasmonic devices with feature sizes of a few nanometers exhibit effects
which can be described by the nonlocal hydrodynamic Drude model. We demonstrate
how to exploit contour integral methods for computing eigenfrequencies and
resonant states of such systems. We propose an approach for deriving the modal
expansion of relevant physical observables. We use the methods to perform a
modal analysis for a metal nanowire. All complex eigenfrequencies in a large
frequency range and the corresponding resonant states are computed. We identify
those resonant states which are relevant for the extinction cross section of
the nanowire.",1906.01941v2
2019-06-05,Resonant algebras in Chern-Simons model of topological insulators,"This paper explores the possibility of using Maxwell algebra and its
generalizations called resonant algebras for the unified description of
topological insulators. We offer the natural action construction, which
includes the relativistic Wen-Zee and other terms, with adjustable coupling
constants. By gauging all available resonant algebras formed by Lorentz,
translational and Maxwell generators $\{J_a, P_a, Z_a\}$ we present six
Chern-Simons Lagrangians with various terms content accounting for different
aspects of the topological insulators.
  Additionally, we provide complementary actions for another invariant metric
form, which might turn out useful in some generalized (2+1) gravity models.",1906.02356v2
2019-07-03,Optomechanical tension and crumpling of resonant membranes,"We predict that illumination by a plane electromagnetic wave of optically
resonant membranes, such as graphene or monolayers of transition metal
dichalcogenides, directly affects their mechanical tension. The induced
optomechanical tension is anisotropic and, depending on the spectral detuning
from the resonance, can be both positive and negative. In the latter case, it
can overcome the bending rigidity of the membrane leading to transition to the
crumpled phase. The instability caused by optomechanical heating of flexural
vibrations is also considered.",1907.02010v1
2019-07-06,Angle-resolved broadband ferromagnetic resonance apparatus enabled through a spring-loaded sample mounting manipulator,"Broadband ferromagnetic resonance is a useful technique to determine the
magnetic anisotropy and study the magnetization dynamics of magnetic thin
films. We report a spring-loaded sample loading manipulator for reliable sample
mounting and rotation. The manipulator enables maximum signal, enhances system
stability and is particularly useful for fully automated in-plane-field
angle-resolved measurements. This angle-resolved broadband ferromagnetic
resonance apparatus provides a viable method to study anisotropic damping and
weak magnetic anisotropies, both vital for fundamental research and
applications.",1907.03097v1
2019-07-17,Role of interactions in the energy of the spin resonance peak in Fe-based superconductors,"We consider the spin response within the five-orbital model for iron-based
superconductors and study two cases: equal and unequal gaps in different bands.
In the first case, the spin resonance peak in the superconducting state appears
below the characteristic energy scale determined by the gap magnitude,
$2\Delta_L$. In the second case, the energy scale corresponds to the sum of
smaller and larger gap magnitudes, $\Delta_L + \Delta_S$. Increasing the values
of the Hubbard interaction and the Hund's exchange, we observe a shift of the
spin resonance energy to lower frequencies.",1907.08133v1
2019-07-21,Ultra-thin Underwater Acoustic Metasurface with Multiply Resonant Units,"This paper describes a new kind of acoustic metasurface with multiply
resonant units, which have previously been used to induce multiple resonances
and effectively produce negative mass density and bulk/shear moduli. The
proposed acoustic metasurface can be constructed using real materials and does
not rely on an ideal rigid material. Therefore, it can work well in a water
background. The thickness of the acoustic metasurface is about two orders of
magnitude smaller than the acoustic wavelength in water. The design of a unit
group is proposed to avoid the phase discretization becoming too fine in such a
long-wavelength condition. We demonstrate that the proposed acoustic
metasurface achieves good performance in anomalous reflection, focusing, and
carpet cloaking.",1907.09016v1
2019-07-23,Backaction-evading measurement of entanglement in optomechanics,"We propose here a fully backaction-evading scheme for the measurement of the
entanglement between two nanomechanical resonators. The system, which consists
of two mechanical oscillators, coupled to a single mode of an electromagnetic
resonant cavity through a radiation-pressure interaction term, is driven by two
pump tones and four detection tones. As previously discussed in the literature,
the former induce entanglement between the two mechanical oscillators, while we
show here that a specific choice of phase and amplitude of the detection tones
allows for direct pairwise reconstruction of the collective quadrature
fluctuations of the mechanical oscillators belonging to quantum-mechanics-free
subspaces, thereby providing direct evidence of the entanglement properties of
the two mechanical resonators.",1907.09882v1
2019-09-29,Nonlinear Floquet dynamics of spinor condensates in an optical cavity: Cavity-amplified parametric resonance,"We investigate Floquet dynamics of a cavity-spinor Bose-Einstein condensate
coupling system via periodic modulation of the cavity pump laser. Parametric
resonances are predicted and we show that due to cavity feedback-induced
nonlinearity the spin oscillation can be amplified to all orders of resonance,
thus facilitating its detection. Real-time observation on Floquet dynamics via
cavity output is also discussed.",1909.13191v1
2019-10-07,Large time behavior of solutions to Schrödinger equation with complex-valued potential,"We study the large-time behavior of the solutions to the Schr\""odinger
equation associated with a quickly decaying potential in dimension three. We
establish the resolvent expansions at threshold zero and near positive
resonances. The large-time expansions of solutions are obtained under different
conditions, including the existence of positive resonances and zero resonance
or/and zero eigenvalue.",1910.03681v2
2019-10-15,Resonant photovoltaic effect in doped magnetic semiconductors,"The rectified non-linear response of a clean undoped semiconductor to an AC
electric field includes a well known intrinsic contribution -- the shift
current. We show that when Kramers degeneracy is broken, a distinct second
order rectified response appears that is due to Bloch state anomalous
velocities in a system with an oscillating Fermi surface. This effect, which we
refer to as the resonant photovoltaic effect (RPE), produces a resonant
galvanic current peak at the interband absorption threshold in doped
semiconductors or semimetals with approximate particle-hole symmetry. We
evaluate the RPE for a model of the surface states of a magnetized topological
insulator.",1910.06570v1
2019-10-25,Photosensitive chalcogenide metasurfaces supporting bound states in the continuum,"We study, both theoretically and experimentally, tunable metasurfaces
supporting sharp Fano-resonances inspired by optical bound states in the
continuum. We explore the use of arsenic trisulfide (a photosensitive
chalcogenide glass) having optical properties which can be finely tuned by
light absorption at the post-fabrication stage. We select the resonant
wavelength of the metasurface corresponding to the energy below the arsenic
trisulfide bandgap, and experimentally control the resonance spectral position
via exposure to the light of energies above the bandgap.",1910.11501v1
2019-10-28,On global dynamics of reaction--diffusion systems at resonance,"In this paper we use the homotopy invariants methods to study the global
dynamics of the reaction-diffusion systems that are at resonance at infinity.
Considering degrees of the resonance for the nonlinear perturbation we
establish Landesman-Lazer type conditions and use them to express the
Rybakowski-Conley index of the invariant set consisting of all bounded
solutions. Obtained results are applied to study the existence of solutions
connecting stationary points for the system of nonlinear heat equations.",1910.12564v2
2019-10-28,Convenient location of a near-threshold proton-emitting resonance in $^{11}$B,"The presence of cluster-like narrow resonances in the vicinity of
reaction/decay thresholds is a ubiquitous phenomenon with profound
consequences. We argue that the continuum coupling, present in the open quantum
system description of the atomic nucleus, can profoundly impact the nature of
near-threshold states. In this Letter, we discuss the structure of the recently
observed near-threshold resonance in $^{11}$B, whose very existence explains
the puzzling beta-delayed proton emission of the neutron-rich $^{11}$Be.",1910.12984v1
2019-10-30,Whispering gallery modes in triple microdisks of triangular configurations,"We study whispering gallery modes in triple microdisks of equilateral and
isosceles triangular configurations. The characteristic properties of resonant
modes in three microdisks on vertices of an equilateral triangle are explained
by discrete rotational symmetry of the triangle. The avoided crossings of
resonant modes in three microdisks on vertices of an isosceles triangle are
also studied in terms of a combination of single and coupled microdisks.
Finally, we propose the matrix models which well explain the resonant modes in
triple microdisks.",1910.13660v2
2020-01-15,Microring resonator-coupled photoluminescence from silicon W~centers,"Defect centers are promising candidates for waveguide-integrated silicon
light sources. We demonstrate microresonator- and waveguide-coupled
photoluminescence from silicon W~centers. Microphotoluminescence measurements
indicate wavelengths on-resonance with resonator modes are preferentially
coupled to an adjacent waveguide. Quality factors of at least 5,300 are
measured, and free spectral ranges closely match expectation. The W~center
phonon sideband can be used as a spectral diagnostic for a broader range
waveguide-based devices on cryogenic silicon photonic platforms.",2001.05100v1
2020-01-16,Tricritical physics in two-dimensional $p$-wave superfluids,"We study effects of quantum fluctuations on two-dimensional $p+ip$
superfluids near resonance. In the standard paradigm, phase transitions between
superfluids and zero density vacuum are continuous. When strong quantum
fluctuations near resonance are taken into account, the line of continuous
phase transitions terminates at two multicritical points near resonance,
between which the transitions are expected to be first-order ones. The size of
the window where first-order phase transitions occur is shown to be substantial
when the coupling is strong. Near first-order transitions, superfluids
self-contract due to phase separations between superfluids and vacuum.",2001.06043v2
2019-11-04,THz graphene W-shaped three-port circulator with dynamical control,"We propose a new graphene-based THz circulator. It consists of a circular
graphene resonator and three graphene nanoribbon waveguides of W-geometry
placed on a dilectric substrate. Surface plasmon-polariton waves propagate in
the waveguides. The nanoribbon excites in the resonator dipole resonance.
Nonreciprocity of the device is defined by nonsymmetry of the conductivity
tensor of the magnetized graphene. The circulator with the central frequency
7.5 THz has the bandwidth 4.25\% for isolation -15 dB, insertion loss -2.5 dB.
Applied DC magnetic field is 0.56T and Fermi energy of graphene
$\epsilon_F=0.15$eV. The Fermi energy allows one to control dynamically the
circulator responses.",2001.10078v1
2020-02-02,Resonant amplified seismic response within a hill or mountain,"We show theoretically what is meant by the term '(surface shape) resonance'
in connection with the seismic response of a protuberance (emerging from flat
ground) such as a hill or mountain of arbitrary shape. We address the specific
problem of cylindrical protuberances of rectangular shape submitted to a SH
plane wave. We find that the principal (i.e., qualitative) characteristics of
the seismic response of a mountain are quite similar to those of a hill, and
that the occurrence of significative amplification of the displacement field
within these structures is due to the coupling of the incident wave to (surface
shape) resonances.",2002.00389v1
2020-02-13,Solitary Waves in Mass-in-Mass Lattices,"We consider the existence of spatially localized traveling wave solutions of
the mass-in-mass lattice. Under an anti-resonance condition first discovered by
Kevrekidis, Stefanov and Xu, we prove that such solutions exist in two
distinguished limits, the first where the mass of the internal resonator is
small and the second where the internal spring is very stiff. We then
numerically simulate the solutions and these simulations indicate that the
anti-resonant traveling waves are weakly unstable",2002.05573v1
2020-02-21,Resonant Quantum Search with Monitor Qubits,"We present an algorithm for the generalized search problem (searching $k$
marked items among $N$ items) based on a continuous Hamiltonian and exploiting
resonance. This resonant algorithm has the same time complexity $O(\sqrt{N/k})$
as the Grover algorithm. A natural extension of the algorithm, incorporating
auxiliary ""monitor"" qubits, can determine $k$ precisely, if it is unknown. The
time complexity of our counting algorithm is $O(\sqrt{N})$, similar to the best
quantum approximate counting algorithm, or better, given appropriate physical
resources.",2002.09522v1
2020-04-07,Interatomic distance dependence of resonant energy-transfer phenomena,"It is well known that interatomic or intermolecular interactions driven by
two-center electronic dipole-dipole correlations fall off rapidly with the
inter-site distance. We show, however, that the effective strength of
interatomic reaction channels, which are triggered by a resonant field, can
exhibit a nonmonotonous distance dependence, being strongly reduced when the
atoms come closer. This surprising result is demonstrated by considering
resonant two-center photoionization as an example. Our findings are supported
by available experimental data.",2004.03439v1
2020-04-14,Hadron resonance gas with van der Waals interactions,"An overview of a hadron resonance gas (HRG) model that includes van der Waals
interactions between hadrons is presented. Applications of the excluded volume
HRG model to heavy-ion collision data and lattice QCD equation of state are
discussed. A recently developed quantum van der Waals hadron resonance gas
model is covered as well. Applications of this model in the context of the QCD
critical point are elaborated.",2004.06331v1
2020-12-30,Light Dark Matter through Resonance Scanning,"We propose a new out-of-equilibrium production mechanism of light dark
matter: resonance scanning. If the dark matter mass evolved in the early
Universe, resonant production may have occurred for a wide range of light dark
matter masses today. We show that the dark matter relic abundance may be
produced through the Higgs portal, in a manner consistent with current
experimental constraints.",2012.15284v1
2021-01-07,Microwave directional dichroism resonant with spin excitations in the polar ferromagnet GaV$_4$S$_8$,"We have investigated the directional dichroism of magnetic resonance spectra
in the polar ferromagnet GaV$_4$S$_8$. While four types of structural domains
are energetically degenerated under zero field, the magnetic resonance for each
domain is well separated by applying magnetic fields due to uniaxial magnetic
anisotropy. Consequently, the directional dichroism as large as 20 % is clearly
observed without domain cancellation. The present observation therefore
demonstrates that not only magnetoelectric mono-domain crystals but also
magnetoelectric multi-domain specimens can be used to realize microwave
(optical) diodes owing to the lack of inversion domains.",2101.02411v1
2012-05-02,Solvable models of resonances and decays,"Resonance and decay phenomena are ubiquitous in the quantum world. To
understand them in their complexity it is useful to study solvable models in a
wide sense, that is, systems which can be treated by analytical means. The
present review offers a survey of such models starting the classical Friedrichs
result and carrying further to recent developments in the theory of quantum
graphs. Our attention concentrates on dynamical mechanism underlying resonance
effects and at time evolution of the related unstable systems.",1205.0512v1
2012-05-09,Local Gating of an Ir(111) Surface Resonance by Graphene Islands,"The influence of graphene islands on the electronic structure of the Ir(111)
surface is investigated. Scanning tunneling spectroscopy (STS) indicates the
presence of a two-dimensional electron gas with a binding energy of -160meV and
an effective mass of -0.18m_e underneath single-layer graphene on the Ir(111)
surface. Density functional calculations reveal that the STS features are
predominantly due to a holelike surface resonance of the Ir(111) substrate.
Nanometer-sized graphene islands act as local gates, which shift and confine
the surface resonance.",1205.1999v1
2012-05-15,Second harmonic generation in phase matched aluminum nitride waveguides,"We demonstrate second order optical nonlinearity in aluminum nitride on
insulator substrates. Using sputter-deposited aluminum nitride thin films we
realize nanophotonic waveguides coupled to micro-ring resonators that
simultaneously support cavity resonant modes for both visible and IR light. By
using phase matched ring resonators, we achieve efficient second-harmonic
generation and are able to generate up to 0.5uW of visible light on the chip
with a conversion efficiency of -46dB. From the measured response we obtain a
second order non-linear susceptibility (\c{hi}2) of 4.7pm/V. Our platform
provides a viable route for realizing wideband linear and nonlinear optical
devices on a chip.",1205.3271v1
2012-05-22,Comparison of capacitive and frequential readout when scaling accelerometers down from Micro- to Nano- Electro Mechanical Systems,"This paper shows the effect of scaling silicon accelerometers down from MEMS
to NEMS. It models both electronics and Brownian noise sources for both
capacitive and resonant devices, and computes the minimum detectable signal
attainable. Computed results are remarkably close to published experimental
results. It shows the relatively low influence of the quality factor and of the
beam width in the resonant case. Different scaling rules are investigated, and
it appears that resonant sensing may satisfy some new application requirements,
in particular for critical dimensions below a few hundreds of nm, when it is
better resolved than capacitive sensing.",1205.4860v1
2012-05-23,ac Stark shift and multiphoton-like resonances in low-frequency driven optical lattices,"We suggest that Bose-Einstein condensates in optical lattices subjected to ac
forcing with a smooth envelope may provide detailed experimental access to
multiphoton-like transitions between ac-Stark-shifted Bloch bands. Such
transitions correspond to resonances described theoretically by avoided
quasienergy crossings. We show that the width of such anticrossings can be
inferred from measurements involving asymmetric pulses. We also introduce a
pulse tracking strategy for locating the particular driving amplitudes for
which resonances occur. Our numerical calculations refer to a currently
existing experimental set-up [Haller et al., PRL 104, 200403 (2010)].",1205.5145v1
2012-05-24,Resonances in 28Si+28Si. I,"A molecular model developed for resonances observed in medium light heavy-ion
collisions is described. At high spins in 28Si+28Si (oblate-oblate system), a
stable dinuclear configuration is found to be equator-equator touching one. The
normal modes around the equilibrium are investigated. These modes are expected
to be the origin of a large number of resonances observed. Furthermore, due to
the axially asymmetric shape of the stable configuration of 28Si+28Si, the
system rotates preferentially around the axis with the largest moment of
inertia, which gives rise to wobbling motion ($K$-mixing). Energy spectra for
the normal modes and for the extended model including the wobbling motion are
given.",1205.5490v1
2012-05-25,Update of the Present Bounds on New Neutral Vector Resonances from Electroweak Gauge Boson Pair Production at the LHC,"The model independent bounds on new neutral vector resonances masses,
couplings and widths presented at arxiv:1112.0316 are updated with an
integrated luminosity of L=4.7 fb^-1 from ATLAS and L=4.6 fb^-1 from CMS. These
exclusion limits correspond to the most stringent existing bounds on the
production of new neutral spin-1 resonances that decay to electroweak gauge
boson pairs and that are associated to the electroweak symmetry breaking sector
in several extensions of the Standard Model.",1205.5802v2
2012-05-31,Minimal Resonant Leptogenesis and Lepton Flavour Violation,"We discuss minimal non-supersymmetric models of resonant leptogenesis, based
on an approximate flavour symmetries. As an illustrative example, we consider a
resonant tau-leptogenesis model, compatible with universal right-handed
neutrino masses at the GUT scale, where the required heavy-neutrino mass
splittings are generated radiatively. In particular, we explicitly demonstrate,
how a minimum number of three heavy Majorana neutrinos is needed, in order to
obtain successful leptogenesis and experimentally testable rates for processes
of lepton flavour violation, such as mu --> e gamma and mu --> e conversion in
nuclei.",1205.6994v1
2017-05-02,Wavelength conversion of data at gigabit rates via nonlinear optics in an integrated micro-ring resonator,"We present the first system penalty measurements for all-optical wavelength
conversion in an integrated ring resonator. We achieve wavelength conversion
over a range of 27.7nm in the C-band at 2.5 Gb/s by exploiting four wave mixing
in a CMOS compatible, high index glass ring resonator at ~22 dBm average pump
power, obtaining < 0.3 dB system penalty.",1705.00778v1
2017-05-04,On the fidelity of quantum information processing with Rydberg atoms: Role of the non-molecular resonances,"Rydberg blockade of ultracold atoms is considered now as one of the most
promising tools for the implementation of quantum computing, but its fidelity
can be substantially compromised by detrimental excitation of the neighbouring
atoms. This phenomenon has been investigated recently in detail for the
particular case of molecular resonances (i.e., resulting in the formation of
quasi-bound states). However, as will be shown in the present paper, an even
greater effect can come from the non-molecular resonances, which therefore
should be taken into account very carefully.",1705.01748v1
2017-05-10,Time-delayed feedback control of coherence resonance chimeras,"Using the model of a FitzHugh-Nagumo system in the excitable regime we
investigate the influence of time-delayed feedback on noise-induced chimera
states in a network with nonlocal coupling, i.e., coherence resonance chimeras.
It is shown that time-delayed feedback allows for control of the range of
parameter values where these chimera states occur. Moreover, for the feedback
delay close to the intrinsic period of the system we find a novel regime which
we call period-two coherence resonance chimera.",1705.03644v1
2017-05-17,Active tuning of high-Q dielectric metasurfaces,"We demonstrate the active tuning of all-dielectric metasurfaces exhibiting
high-quality factor (high-Q) resonances. The active control is provided by
embedding the asymmetric silicon meta-atoms with liquid crystals, which allows
the relative index of refraction to be controlled through heating. It is found
that high quality factor resonances ($Q=270\pm30$) can be tuned over more than
three resonance widths. Our results demonstrate the feasibility of using
all-dielectric metasurfaces to construct tunable narrow-band filters.",1705.06099v1
2017-05-07,Tunable Optical Bistability and Optical Switching by Nonlinear Metamaterials,"We demonstrate a nonlinear metamaterial in microwave frequency regime with
hysteresis effect and bistable states, which can be utilized as a remotely
controllable micro second switching device. A varactor loaded split-ring
resonator (SRR) design which exhibits power and frequency dependent broadband
tunability of the resonance frequency for an external control signal is used.
More importantly, the SRR shows bistability with distinct transmission levels.
The transition between bi-states is controlled by impulses of an external pump
signal. Furthermore, we experimentally demonstrate that transition rate is in
the order of microseconds by using a varactor loaded double split-ring
resonator (DSRR) design composed of two concentric rings.",1705.07719v1
2017-05-24,Boundedness in forced isochronous oscillators,"In this paper we are concerned with the boundedness of all solutions for the
forced isochronous oscillator $$x''+V'(x)+g(x)=f(t),$$ where $V$ is a so-called
$T$-isochronous potential, the perturbation $g$ is assumed to be bounded, and
the $2\pi$-periodic function $f(t)$ is smooth. Using the resonant small twist
theorem and averaged small twist theorem established by Ortega, we will prove
the boundedness of all solutions for the above forced isochronous oscillator in
the resonant and non-resonant cases under some reasonable assumptions,
respectively.",1705.08693v1
2017-05-25,Prediction of ultra-narrow Higgs resonance in magnon Bose-condensates,"Higgs resonance modes in condensed matter systems are generally broad;
meaning large decay widths or short relaxation times. This common feature has
obscured and limited their observation to a select few systems. Contrary to
this, the present work predicts that Higgs resonances in magnetic field
induced, three-dimensional magnon Bose-condensates have vanishingly small decay
widths. Specifically for parameters relating to TlCuCl$_3$, we find an energy
($\Delta_H$) to width ($\Gamma_H$) ratio $\Delta_H/\Gamma_H\sim500$, making
this the narrowest predicted Higgs mode in a condensed matter system, some two
orders of magnitude `narrower' than the sharpest condensed matter Higgs
observed so far.",1705.09007v1
2017-09-18,Searches for New Heavy Resonances in Final States with Leptons and Photons in ATLAS and CMS,"Searches for resonances in final states with leptons and photons have always
been a powerful tool for discovery in high energy physics. We present here the
latest results from the ATLAS and CMS experiments, based on up to 36.1
fb$^{-1}$ of 13 TeV proton-proton collisions produced at the Large Hadron
Collider. Detailed results on single lepton, dilepton, diphoton and Z$\gamma$
resonances are included.",1709.06119v1
2017-09-22,On the continuation of degenerate periodic orbits via normal form: full dimensional resonant tori,"We reconsider the classical problem of the continuation of degenerate
periodic orbits in Hamiltonian systems. In particular we focus on periodic
orbits that arise from the breaking of a completely resonant maximal torus. We
here propose a suitable normal form construction that allows to identify and
approximate the periodic orbits which survive to the breaking of the resonant
torus. Our algorithm allows to treat the continuation of approximate orbits
which are at leading order degenerate, hence not covered by classical averaging
methods. We discuss possible future extensions and applications to localized
periodic orbits in chains of weakly coupled oscillators.",1709.07824v1
2017-09-28,Creating anyons from photons using a nonlinear resonator lattice subject to dynamic modulation,"We study a one-dimensional photonic resonator lattice with Kerr nonlinearity
under the dynamic modulation. With an appropriate choice of the modulation
frequency and phase, we find that this system can be used to create anyons from
photons. By coupling the resonators with external waveguides, the anyon
characteristics can be explored by measuring the transport property of the
photons in the external waveguides.",1709.09769v1
2017-09-28,Negative index and mode coupling in all-dielectric metamaterials at terahertz frequencies,"We report on the role of the coupling of the modes of Mie resonances in
all-dielectric metamaterials to ensure negative effective index at terahertz
frequencies. We study this role according to the lattice period and according
to the frequency overlapping of the modes of resonance. We show that negative
effective refractive index requires sufficiently strong mode coupling and that
for even more strong mode coupling, the first two modes of Mie resonances are
degenerated; the effective refractive index is then undeterminded. We also show
that adjusting the mode coupling leads to near-zero effective index, or even
null effective index. Further, we compare the mode coupling effect with
hybridization in metamaterials.",1709.09998v1
2017-11-03,Resonance oscillations of non-reciprocal long-range van der Waals forces between atoms in electromagnetic fields,"We study theoretically the van der Waals interaction between two atoms out of
equilibrium with isotropic electromagnetic field. We demonstrate that at large
interatomic separations, the van der Waals forces are resonant, spatially
oscillating and non-reciprocal due to resonance absorption and emission of
virtual photons. We suggest that the van der Waals forces can be controlled and
manipulated by tuning the spectrum of artificially created random light.",1711.01205v2
2017-11-05,Two Dimensional Edge Detection by Guided Mode Resonant Metasurface,"In this letter, a new approach to perform edge detection is presented using
an all-dielectric CMOS-compatible metasurface. The design is based on
guided-mode resonance which provides a high quality factor resonance to make
the edge detection experimentally realizable. The proposed structure that is
easy to fabricate, can be exploited for detection of edges in two dimensions
due to its symmetry. Also, the trade-off between gain and resolution of edge
detection is discussed which can be adjusted by appropriate design parameters.
The proposed edge detector has also the potential to be used in ultrafast
analog computing and image processing.",1711.01606v2
2017-11-07,Dzyaloshinskii-Moriya interaction induced extrinsic linewidth broadening of ferromagnetic resonance,"For a thin ferromagnetic film with the Dzyaloshinskii-Moriya interaction
(DMI), we derive an expression of the extrinsic ferromagnetic resonance (FMR)
linewidth in a quantum mechanical way, taking into account scatterings from
structural inhomogeneity. In the presence of the DMI, the magnon dispersion
exhibits rich resonant states, especially in small external magnetic fields and
strong DMI strength. It is found that the FMR linewidth shows several
characteristic features such as a finite linewidth at zero frequency and peaks
in the low frequency range.",1711.02263v1
2017-11-08,Electromagnetic transition form factors of the Roper resonance in baryon chiral perturbation theory,"We consider the electromagnetic transition form factors of the Roper
resonance in the framework of an effective field theory of pions, nucleons and
delta and Roper resonances as explicit degrees of freedom. Due to the lack
experimental data in the region of applicability of low energy effective field
theory we fit available free coupling constants and compare obtained results
compare to the predictions of a theoretical model.",1711.03494v1
2017-11-10,Frequency-comb based double-quantum two-dimensional coherent spectroscopy identifies collective hyperfine resonances in atomic vapor induced by dipole-dipole interactions,"Frequency comb based multidimensional coherent spectroscopy is a novel
optical method that enables high resolution measurement in a short acquisition
time. The method's resolution makes multidimensional coherent spectroscopy
relevant for atomic systems that have narrow resonances. We use double-quantum
multidimensional coherent spectroscopy to reveal collective hyperfine
resonances in rubidium vapor at 100 C induced by dipole-dipole interactions. We
observe tilted lineshapes in the double-quantum 2D spectra, which has never
been reported for Doppler-broadened systems. The tilted lineshapes suggest that
the signal is predominately from the interacting atoms that have near zero
relative velocity.",1711.03659v1
2017-11-10,GenEx - Exclusive Meson Generator,"Exclusive light meson production processes possible to be measured at RHIC
and LHC accelerators are briefly described. This includes Pomeron and photon
induced continuum of pions and kaons as well as $f_0$ and $\rho^0$ resonant
production. Next, GenEx, a new Monte Carlo generator recently developed in
Cracow, is presented. Its purpose is to generate resonant and non-resonant pion
and kaon production and diffractive Bremsstrahlung. Its future development will
take into account spin (polarization) effects and simulate corrections due to
absorption and re-scattering.",1711.03797v2
2018-03-06,Compactness of iso-resonant potentials for Schrödinger operators in dimensions one and three,"We prove compactness of a restricted set of real-valued, compactly supported
potentials $V$ for which the corresponding Schr\""odinger operators $H_V$ have
the same resonances, including multiplicities. More specifically, let $B_R(0)$
be the ball of radius $R > 0$ about the origin in $R^d$, for $d=1,3$. Let
$\mathcal{I}_R (V_0)$ be the set of real-valued potentials in $C_0^\infty(
\overline{B}_R(0); R)$ so that the corresponding Schr\""odinger operators have
the same resonances, including multiplicities, as $H_{V_0}$. We prove that the
set $\mathcal{I}_R (V_0)$ is a compact subset of $C_0^\infty
(\overline{B}_R(0))$ in the $C^\infty$-topology. An extension to Sobolev spaces
of less regular potentials is discussed.",1803.02172v1
2018-03-06,Pinning Transition of Bose-Einstein Condensates in Optical Ring Resonators,"We experimentally investigate the dynamic instability of Bose-Einstein
condensates in an optical ring resonator that is asymmetrically pumped in both
directions. We find that, beyond a critical resonator-pump detuning, the system
becomes stable regardless of the pump strength. Phase diagrams and quenching
curves are presented and described by numerical simulations. We discuss a
physical explanation based on a geometric interpretation of the underlying
nonlinear equations of motion.",1803.02293v2
2018-03-15,Resonant Robin problems driven by the $p$-Laplacian plus an indefinite potential,"We consider a nonlinear Robin problems driven by the $p$-Laplacian plus an
indefinite potential. The reaction is resonant with respect to a variational
eigenvalue. For the principal eigenvalue we assume strong resonance. Using
variational tools and critical groups we prove existence and multiplicity
theorems.",1803.05680v1
2018-03-17,"500MHz resonant photodetector for high-quantum-effciency, low-noise homodyne measurement","We design and demonstrate a resonant-type differential photodetector for
low-noise quantum homodyne measurement at 500MHz optical sideband with 17MHz of
bandwidth. By using a microwave monolithic amplifier and a discrete voltage
buffer circuit, a low-noise voltage amplifier is realized and applied to our
detector. 12dB of signal-to-noise ratio of the shot noise to the electric noise
is obtained with 5mW of continuous-wave local oscillator. We analyze the
frequency response and the noise characteristics of a resonant photodetector,
and the theoretical model agrees with the shot noise measurement.",1803.06462v2
2018-03-18,Effect of gap anisotropy on the spin resonance peak in the superconducting state of iron-based materials,"Spin resonance in the superconducting state of Fe-based materials within the
multiorbital model with unequal anisotropic gaps on different Fermi surface
sheets is studied. On the basis of the model gap function and the one
calculated within the spin fluctuation theory of pairing, I show that the
resonance peak shifts to higher frequencies with increasing the zero-amplitude
gap magnitude. On the contrary, with increasing the gap anisotropy, it shifts
to lower frequencies and lose some intensity.",1803.06736v2
2018-03-23,Width of a two-body coupled-channel resonance,"We study the width of a two-body resonance in a coupled-channel system. We
demonstrate how the width does not come only determined by the available phase
space for its decay to the detection channel, but it greatly depends on the
relative position of the mass of the resonance with respect to the masses of
the coupled-channels generating the state. Our results are consistent with the
experimental observation of narrow hadrons lying well above their lowest decay
threshold.",1803.08685v1
2018-03-23,Effect of thresholds on the width of three-body resonances,"It has been recently reported an intriguing theoretical result of a narrow
three-body resonance with a large available phase space. The resonance was
reported in the $N\Lambda\Lambda-\Xi NN$ system near the $\Xi d$ threshold,
having a very small width in spite of the open $N\Lambda\Lambda$ channel lying
around 23 MeV below the $\Xi NN$ channel. We use first-order perturbation
theory as a plausible argument to explain this behavior. We apply our result to
realistic local interactions. Other systems involving several thresholds are
likely to follow the same behavior.",1803.09644v1
2018-03-27,Point-like perturbed fractional Laplacians through shrinking potentials of finite range,"We reconstruct the rank-one, singular (point-like) perturbations of the
$d$-dimensional fractional Laplacian in the physically meaningful
norm-resolvent limit of fractional Schr\""{o}dinger operators with regular
potentials centred around the perturbation point and shrinking to a delta-like
shape. We analyse both the possible regimes, the resonance-driven and the
resonance-independent limit, depending on the power of the fractional Laplacian
and the spatial dimension. To this aim, we also qualify the notion of
zero-energy resonance for Schr\""{o}dinger operators formed by a fractional
Laplacian and a regular potential.",1803.10191v2
2018-06-05,Resonant photoemission with circular polarized light on magnetized LSMO,"We have used resonant photoemission with circular polarized light as a new
tool to obtain information about the electronic structure of half-metals. After
careful sample surface preparation of La0.7Sr0.3MnO3, we have obtained a
dichroic signal for the L2,3 absorption of Mn. Working with a magnetized sample
and circular polarized light we observe a clear effect of the helicity of light
on the position of the resonant Raman-Auger photoelectrons from the Mn 2p3p3d
decay. These results allow us to achieve a rough estimate of the half-metallic
spin half-gap.",1806.01833v1
2018-06-28,Platonic Localisation: One Ring to Bind Them,"In this paper, we present an asymptotic model describing localised flexural
vibrations along a structured ring containing point masses or spring-mass
resonators in an elastic plate. The values for the required masses and
stiffnesses of resonators are derived in a closed analytical form. It is shown
that spring-mass resonators can be tuned to produce a ""negative inertia"" input,
which is used to enhance localisation of waveforms around the structured ring.
Theoretical findings are accompanied by numerical simulations, which show
exponentially localised and leaky modes for different frequency regimes.",1806.11512v1
2018-07-05,Effect of resonance for $CP$ asymmetry of the decay process $\bar{B}_{s}\rightarrow Pπ^+π^-$ in perturbative QCD,"In the framework of Perturbative QCD (PQCD) approach we study the direct $CP$
asymmetry for the decay channel $\bar{B}_{s}\rightarrow P\pi^+\pi^-$ around the
resonance range via the $\rho-\omega$ mixing mechanism (where P refer to
pseudoscalar meson). We find that the $CP$ asymmetry can be enhanced by
$\rho-\omega$ mixing when the masses of the $\pi^+\pi^-$ pairs are at the area
of $\rho-\omega$ resonance, and the maximum $CP$ asymmetry can reach 59{\%} for
the relevant decay channels.",1807.02049v1
2018-07-14,Plasmonic Helicity-Driven Detector of terahertz radiation,"We develop a theory of the helicity driven nolinear dc response of gated
two-dimensional electron gas to the terahertz radiation. We demonstrate that
the helicity-sensitive part of the response dramatically increases in the
vicinity of the plasmonic resonances and oscillates with the phase shift
between excitation signals on the source and drain. The resonance line shape is
an asymmetric function of the frequency deviation from the resonance. In
contrast, the helicity-insensitive part of the response is symmetrical. These
properties yield significant advantage for using plasmonic detectors as
terahertz and far infrared spectrometers and interferometers.",1807.05456v1
2018-07-25,Bifurcations and Monodromy of the Axially Symmetric 1:1:-2 Resonance,"We consider integrable Hamiltonian systems in three degrees of freedom near
an elliptic equilibrium in 1:1:-2 resonance. The integrability originates from
averaging along the periodic motion of the quadratic part and an imposed
rotational symmetry about the vertical axis. Introducing a detuning parameter
we find a rich bifurcation diagram, containing three parabolas of Hamiltonian
Hopf bifurcations that join at the origin. We describe the monodromy of the
resulting ramified 3-torus bundle as variation of the detuning parameter lets
the system pass through 1:1:-2 resonance.",1807.09453v2
2018-07-30,Model independent top quark width measurement using a combination of resonant and non resonant cross sections,"Though top quark was discovered more than twenty years ago, measurement of
its width is still challenging task. Most measurements either have rather low
precision or they are done in assumption of the SM top quark interactions. We
consider model independent parametrization of the top quark width and provide
estimations on achievable accuracy using a combination of fiducial cross
sections in double, single and non-resonant regions.",1807.11193v2
2018-08-06,Coupled channels dynamics in the generation of the $Ω(2012)$ resonance,"We look into the newly observed $\Omega (2012)$ state from the molecular
perspective in which the resonance is generated from the $\bar{K} \Xi^*$, $\eta
\Omega$ and $\bar{K} \Xi$ channels. We find that this picture provides a
natural explanation of the properties of the $\Omega (2012)$ state. We stress
that the molecular nature of the resonance is revealed with a large coupling of
the $\Omega (2012)$ to the $\bar{K} \Xi^*$ channel, that can be observed in the
$\Omega (2012) \rightarrow \bar{K} \pi \Xi$ decay which is incorporated
automatically in our chiral unitary approach via the use of the spectral
function of $\Xi^*$ in the evaluation of the $\bar{K} \Xi^*$ loop function.",1808.01950v1
2018-08-11,Antiresonances and Ultrafast Resonances in a Twin Photonic Oscillator,"We consider the properties of the small-signal modulation response of
symmetry-breaking phase-locked states of twin coupled semiconductor lasers. The
extended stability and the varying asymmetry of these modes allows for the
introduction of a rich set of interesting modulation response features, such as
sharp resonances and anti-resonance as well as efficient modulation at very
high frequencies exceeding the free running relaxation frequencies by orders of
magnitude.",1808.03760v1
2018-08-14,An iterative method to estimate the combinatorial background,"The reconstruction of broad resonances is important for understanding the
dynamics of heavy ion collisions. However, large combinatorial background makes
this objective very challenging. In this work an innovative iterative method
which identifies signal and background contributions without input models for
normalization constants is presented. This technique is successfully validated
on a simulated thermal cocktail of resonances. This demonstrates that the
iterative procedure is a powerful tool to reconstruct multi-differentially
inclusive resonant signals in high multiplicity events as produced in heavy ion
collisions.",1808.05466v1
2018-12-02,Bidirectional and passive optical field to microwave field quantum converter with high bandwidth,"The conversion between microwave photons and optical photons with quantum
coherence is important for quantum communication and computation. In this
paper, we report a proposal using an ensemble of atoms coupled to microwave and
optical resonators. Input photons to one resonator are converted into output
photons in the other resonator without active operation. Usually the conversion
is only optimized at certain frequency. In our proposal, we find that the
efficiency is almost a constant and can be close to 100% in a large interval of
frequency, i.e. a high-bandwidth conversion can be realized with our proposal.",1812.00360v1
2018-11-20,Application of resonant decay method for compound-systems at analysis inclusive spectra in high-energy nuclear reactions,"It is shown, that the exponential decrease of the energy spectra of the
fragments with growing its energy, which does not depend from the fragment
type, targets, projectiles and projectile energies, and which sometimes
accompanied slight oscillations, can be explained by the phenomenon of time
resonances. These time resonances correspond to decay of intermediate excited
nuclear composite system. For the first time, expressions for the decay rate
and the probability of survival of such system as a function of time are
obtained. Inclusive spectra for two real high-energy nuclear reactions are
calculated.",1812.00747v2
2018-12-05,The Roper resonance as a meson-baryon molecular state,"The recently proposed mechanism for the formation of the Roper resonance, in
which a dynamically generated state as well as a genuine three-quark resonant
state play an equally important role, is confronted with the model proposed
almost twenty years ago in which the Roper is pictured as a molecular state of
the nucleon and the $\sigma$ meson.",1812.02043v1
2018-12-10,Rotation measurements using a a resonant fiber optic gyroscope based on Kagome fiber,"We build a resonant fiber optic gyro based on Kagome hollow-core fiber. A
semi-bulk cavity architecture based on a 18-m-long Kagome fiber permits to
achieve a cavity finesse of 23 with a resonance linewidth of 700 kHz. An
optimized Pound-Drever-Hall servo-locking scheme is used to probe the cavity in
reflection. Closed-loop operation of the gyroscope permits to reach an angular
random walk as small as 0.004$^\circ/\sqrt{\mathrm{h}}$ and a bias stability of
0.45$^\circ$/h over 0.5 s of integration time.",1812.04694v1
2018-11-19,Application of the method of multiple scales to unravel energy exchange in nonlinear locally resonant metamaterials,"In this paper, the effect of weak nonlinearities in 1D locally resonant
metamaterials is investigated via the method of multiple scales. Commonly
employed to the investigate the effect of weakly nonlinear interactions on the
free wave propagation through a phononic structure or on the dynamic response
of a Duffing oscillator, the method of multiple scales is here used to
investigate the forced wave propagation through locally resonant metamaterials.
The perturbation approach reveals that energy exchange may occur between
propagative and evanescent waves induced by quadratic nonlinear local
interaction.",1812.05713v1
2018-12-18,Tunable quantum interference in bilayer graphene in double-resonant Raman scattering,"The line shape of the double-resonant $2D$ Raman mode in bilayer graphene is
often considered to be characteristic for a certain laser excitation energy.
Here, in a joint experimental and theoretical study, we analyze the dependence
of the double-resonant Raman scattering processes in bilayer graphene on the
electronic broadening parameter $\gamma$. We demonstrate that the ratio between
symmetric and anti-symmetric scattering processes sensitively depends on the
lifetime of the electronic states, explaining the experimentally observed
variation of the complex $2D$-mode line shape.",1812.07305v1
2018-12-30,Nonlinear Coupling of Linearly Uncoupled Resonators,"We demonstrate a system composed of two resonators that are coupled solely
through a nonlinear interaction, and where the linear properties of each
resonator can be controlled locally. We show that this class of dynamical
systems has peculiar properties with important consequences for the study of
classical and quantum nonlinear optical phenomena. As an example we discuss the
case of dual-pump spontaneous four-wave mixing.",1812.11484v1
2018-12-31,Nuclear effects in the deuteron in the resonance and deep-inelastic scattering region,"We discuss a hybrid model of the proton and neutron inelastic structure
functions which incorporates both the partonic and the nucleon resonance
structures and applicable in a wide region of the invariant mass $W$ of
produced hadronic states. Focusing at the typical kinematics of JLab
experiments we compute the deuteron structure functions and demonstrate good
performance of the model against data. We perform systematic study of the
ratios $F_2^n/F_2^d$ and $(F_2^p+F_2^n)/F_2^d$ for both, the deep-inelastic and
the resonance, region in the context of recent measurements of BoNuS experiment
at Jefferson Lab.",1812.11738v1
2019-01-14,Quantum simulation scheme of two-dimensional xy-model Hamiltonian with controllable coupling,"We study a scheme of quantum simulator for two-dimensional xy-model
Hamiltonian. Previously the quantum simulator for a coupled cavity array spin
model has been explored, but the coupling strength is fixed by the system
parameters. In the present scheme several cavity resonators can be coupled with
each other simultaneously via an ancilla qubit. In the two-dimensional Kagome
lattice of the resonators the hopping of resonator photonic modes gives rise to
the tight-binding Hamiltonian which in turn can be transformed to the quantum
xy-model Hamiltonian. We employ the transmon as an ancilla qubit to achieve in
situ controllable xy-coupling strength.",1901.04350v1
2019-01-14,Resonant Excitation of Oscillator with Randomly Shifted Levels,"The problem of resonant excitation of a harmonic oscillator the energy levels
of which are slightly shifted under the action of a random potential is solved.
It is shown that, in this case, there exists a threshold magnitude of the
exciting resonance field, below which the excitation is localized on lower
levels, and above which the oscillator is indefinitely excited so that it is
necessary to take into account dissipative processes. A method similar to that
developed for the oscillator is applied to examine the localization of
electrons in a wire with cross-section varying along its length. It is shown,
in particular, that there is no localization if this variation is superlinear.",1901.04435v1
2019-01-26,Dark resonance formation with magnetically-induced transitions: extension of spectral range and giant circular dichroism,"Dark resonances were formed via electromagnetically induced transparency for
the first time involving magnetically-induced $\Delta F = \pm2$ atomic
transitions of alkali metal atom, which are forbidden at zero magnetic field.
The probability of these transitions undergoes rapid growth when $300 - 3000$~G
magnetic field is applied, allowing formation of dark resonances, widely
tunable in the GHz range. It is established that for $\Delta F = +2$ ($\Delta F
=-2$) transition, the coupling laser tuned to $\Delta F = +1$ ($\Delta F =-1$)
transition of the hyperfine $\Lambda$-system must be $\sigma^+$ ($\sigma^-$)
polarized, manifesting anomalous circular dichroism.",1901.09226v1
2019-02-15,Long-distance entangling gates between quantum dot spins mediated by a superconducting resonator,"Recent experiments with silicon qubits demonstrated strong coupling of a
microwave resonator to the spin of a single electron in a double quantum dot,
opening up the possibility of long-range spin-spin interactions. We present our
theoretical calculation of effective interactions between distant quantum dot
spins coupled by a resonator, and propose a protocol for fast, high-fidelity
two-qubit gates consistent with experimentally demonstrated capabilities. Our
simulations show that, in the presence of noise, spin-spin entangling gates
significantly outperform cavity-mediated gates on charge qubits.",1902.05704v2
2019-03-01,Superconducting Quantum Annealing Architecture with LC Resonators,"We propose a novel architecture for superconducting circuits to improve the
efficiency of a quantum annealing system. To increase the capability of a
circuit, it is desirable for a qubit to be coupled not only with adjacent
qubits but also with other qubits located far away. We introduce a circuit that
uses a lumped element resonator coupled each with one qubit. The
resonator-qubit pairs are coupled by rf-superconducting quantum interference
device (SQUID) based couplers. These pairs make a large quantum system for
quantum annealer. This system could prepare the problem Hamiltonian and tune
the parameters for quantum annealing procedure.",1903.00187v2
2019-03-25,On resonance contribution to balance functions,"It is known that resonance decays influence the shape of the charge-balance
functions measured in hadronic collisions. That is reflected in their rapidity
and azimuthal widths and the integral, and therefore has consequences for
different model interpretations. In this paper, we show that the contribution
from neutral resonance decays can be removed from the balance function in an
analytical way, and test the performance of the removal procedure with PYTHIA
events. Prospects for applications of the procedure to real data analysis of
balance functions are also discussed.",1903.10085v2
2019-04-01,"Comment on ""Is a Trineutron Resonance Lower in Energy than a Tetraneutron Resonance?"" [arXiv:1612.01502]","The quantum Monte Carlo study [S. Gandolfi, H.-W. Hammer, P. Klos, J. E.
Lynn, and A. Schwenk, Phys. Rev. Lett. {\bf 118}, 232501 (2017),
arXiv:1612.01502] of few-neutron resonant states provided results incompatible
with rigorous few-body calculations. In this Comment we point out serious
shortcomings in the work by Gandolfi et al, leading to misinterpretation of
unbound few-body systems.",1904.00925v1
2019-04-18,Statistical analysis of many single-molecule encounters reveals plasmonic resonance dependent nanoantenna-molecule interactions,"The nanoscale interaction between single emitters and plasmonic structures is
traditionally studied by relying on near-perfect, deterministic,
nanoscale-control. This approach is ultra-low throughput thus rendering
systematic studies difficult to impossible. Here, we show that super resolution
microscopy in combination with data-driven statistical analysis allows studying
near-field interactions of single molecules with resonant nanoantennas. We
systematically tune the antennas' spectral resonances and show that emitters
can be separated according to their coupling strength with said structures
which ultimately allows the reconstruction of 2D interaction maps around
individual nanoantennas.",1904.08883v2
2019-04-28,Single atom laser in normal-superconductor quantum dots,"We study a single-level quantum dot strongly coupled to a superconducting
lead and tunnel-coupled to a normal electrode which can exchange energy with a
single-mode resonator. We show that a such system can sustain lasing
characterized by a sub-Poissonian Fock-state distribution of the resonator. The
lasing regime is clearly identifiable in the subgap transport regime: in the
resonant case, the current is pinned to the maximum value achievable in this
hybrid nanostructure.",1904.12278v1
2019-04-29,Widths of resonances above an energy-level crossing,"We study the existence and location of the resonances of a $2\times 2$
semiclassical system of coupled Schr\""odinger operators, in the case where the
two electronic levels cross at some point, and one of them is bonding, while
the other one is anti-bonding. Considering energy levels just above that of the
crossing, we find the asymptotics of both the real parts and the imaginary
parts of the resonances close to such energies. This is a continuation of our
previous works where we considered energy levels around that of the crossing.",1904.12511v1
2019-11-13,On the time-evolution of resonant triads in rotational capillary-gravity water waves,"We investigate an effect of the resonant interaction in the case of
one-directional propagation of capillary-gravity surface waves arising as the
free surface of a rotational water flow. Specifically, we assume a constant
vorticity in the body of the fluid which physically corresponds to an
underlying current with a linear horizontal velocity profile. We consider the
interaction of three distinct modes and we obtain the dynamic equations for a
resonant triad. Setting the constant vorticity equal to zero we recover the
well known integrable three-wave system.",1911.05213v1
2019-11-26,Kalb-Ramond field localization on a de Sitter Thick Brane,"In this paper, we study the localization of Kalb-Ramond (KR) tensorial gauge
field on a non-flat de Sitter thick brane. The localization and resonance of KR
gauge field are discussed for three kinds of couplings. For the first coupling
there is no localized tensorial zero mode. For the other two couplings, the
zero mode of KR field can be localized under certain condition. There are
resonant KK modes on the thick brane for the third case. Furthermore, we mainly
analyze the effects of three parameters on the localization and resonant mode
for KR field.",1911.11438v1
2019-12-09,Hyperon resonances and meson-baryon interactions in isospin 1,"In this work we extend our formalism to study meson-baryon interactions by
including $s$- and $u$-channel diagrams for pseudoscalar-baryon systems. We
study the coupled systems with strangeness $-1$ and focus on studying the
isospin-1 resonance(s), especially in the energy region around 1400 MeV. By
constraining the model parameters to fit the cross section data available on
several processes involving relevant channels, we find resonances in the
isoscalar as well as the isovector sector in the energy region around 1400 MeV.",1912.04329v2
2019-12-18,Towards resonance properties in the Dyson-Schwinger approach,"We give a brief summary of the Dyson-Schwinger and Bethe-Salpeter approach to
hadron spectroscopy and report on recent progress in determining resonance
properties in this framework. We exemplify the extraction of resonances using a
scalar model, where we solve the scattering equation for the four-point
scattering amplitude and extract the pole locations on the second Riemann sheet
as well as the phase shifts.",1912.08873v1
2019-12-21,Resonance free domain for a system of Schrödinger operators with energy-level crossings,"We consider a $2\times 2$ system of 1D semiclassical differential operators
with two Schr\""odinger operators in the diagonal part and small interactions of
order $h^\nu$ in the off-diagonal part, where $h$ is a semiclassical parameter
and $\nu$ is a constant larger than $1/2$. We study the absence of resonance
near a non-trapping energy for both Schr\""odinger operators in the presence of
crossings of their potentials. The width of resonances is estimated from below
by $Mh\log(1/h)$ and the coefficient $M$ is given in terms of the directed
cycles of the generalized bicharacteristics induced by two Hamiltonians.",1912.10180v1
2019-12-31,Series Resonant Matrix Converter Topology for EV DC Fast Charging,"In this paper, we presented a matrix converter with a high-frequency DC link
for EV DC fast charging applications. Introducing this topology allows
eliminating electrolytic capacitors in DC link of the converter, which
potentially increases the reliability and power density of the system. The
converter uses bidirectionally blocking three-phase rectifier to generate a
high-frequency square wave voltage for the series resonant LC DC/DC converter,
eliminating one H-bridge in front of the resonant tank. Principles of
high-frequency and low-frequency modulations are described. A low voltage
prototype has been built and tested which demonstrated ZVS soft switching of
all the transistors in the converter. Peak efficiency estimated as 98.0 % for
state-of-the-art switches.",1912.13241v1
2020-03-05,Mathematical modelling of plasmonic strain sensors,"We provide a mathematical analysis for a metasurface constructed of plasmonic
nanoparticles mounted periodically on the surface of a microcapsule. We derive
an effective transmission condition, which exhibits resonances depending on the
inter-particle distance. When the microcapsule is deformed, the resonances are
shifted. We fully characterise the dependence of these resonances on the
deformation of the microcapsule, enabling the detection of strains at the
microscale level. We present numerical simulations to validate our results.",2003.02787v1
2020-03-12,The Roper Resonance in a finite volume,"We calculate the energy levels corresponding to the Roper resonance based on
a two-flavor chiral effective Lagrangian for pions, nucleons, deltas and the
Roper resonance at leading one-loop order. We show that the Roper mass can be
extracted from these levels for not too large lattice volumes.",2003.05745v2
2020-05-07,Excited-State Trions in Two Dimensional Materials,"Using the complex scaling and the stabilization method combined with the
stochastic variational approach, we have shown that there are narrow resonance
states in two-dimensional three particle systems of electrons and holes
interacting via screened Coulomb interaction. These resonances are loosely
bound systems of excited state excitons with a third particle circling around
them. Recent experimental studies of excited state trions might be explained
and identified by these resonant states.",2005.03722v1
2020-05-12,Circuit-model formulas for external-Q factor of resonant cavities with capacitive and inductive coupling,"The external-Q factor of a resonant mode of a cavity represents the strength
of the electromagnetic coupling between this resonant mode and the transmission
mode of a waveguide coupled to the cavity. In this paper, we derive formulas to
explicitly give the external Q of the cavities coupled with the waveguide
through capacitive and inductive coupling. The derivation is based on the
classical method that uses the reflection coefficient to estimate the coupling
strength. Although the external Q is evaluated via three-dimensional computer
simulations currently, these formulas may be useful for making speculations in
the initial stages of cavity design.",2005.05843v2
2020-05-22,Effect of the nearby levels on the resonance fluorescence spectrum of the atom-field interaction,"We study the resonance fluorescence in the Jaynes-Cummings model when nearby
levels are taking into account. We show that the Stark shift produced by such
levels generates a displacement of the peaks of the resonance fluorescence due
to an induced effective detuning and also induces an asymmetry. Specific
results are presented assuming a coherent and a thermal fields.",2005.11298v1
2020-05-28,Thickness-independent narrow resonance in a stack of two plasmonic lattices,"Plasmonic lattices consisting of nanoparticles in a homogeneous environment
are well known fortheir support of so-called lattice plasmon resonances. They
are associated with localized surfaceplasmons coupled to each other via free
propagating photons along the structure. In this paper, weexplore modes in a
stack of two identical plasmonic lattices. We demonstrate that such a
structureis able to support a mode that is positioned strictly on a Rayleigh
anomaly and does not shift withthe variation of distance between two lattices
in wide limits. Given the fact that period is the moststably reproduced
quantity in an experiment, such behavior can be used to simplify the
fabricationof structures with resonances at desired energies.",2005.14300v1
2020-06-06,Lambda(1405) as a K-bar N Feshbach resonance in the Skyrme model,"We describe the Lambda(1405) hyperon as a Feshbach resonance of a bar-KN
quasi-bound state coupled by a decaying channel of pi Sigma in the Skyrme
model. A weakly bound bar-KN state is generated in the laboratory frame, while
the Sigma hyperon as a strongly bound state of bar-KN in the intrinsic frame.
We obtain a coupling of bar-KN and pi Sigma channels by computing a baryon
matrix element of the axial current. This coupling enables the decay of the
bar-KN bound state to pi-Sigma . It is shown that the Skyrme model supports the
Lambda(1405) as a narrow Feshbach resonance.",2006.03788v1
2020-06-15,On weakly turbulent solutions to the perturbed linear Harmonic oscillator,"We introduce specific solutions to the linear harmonic oscillator, named
bubbles. They form resonant families of invariant tori of the linear dynamics,
with arbitrarily large Sobolev norms. We use these modulated bubbles of energy
to construct a class of potentials which are real, smooth, time dependent and
uniformly decaying to zero with respect to time, such that the corresponding
perturbed quantum harmonic oscillator admits solutions which exhibit a
logarithmic growth of Sobolev norms. The resonance mechanism is explicit in
space variables and produces highly oscillatory solutions. We then give several
recipes to construct similar examples using more specific tools based on the
continuous resonant (CR) equation in dimension two.",2006.08206v1
2020-06-22,Prediction of short time qubit readout via measurement of the next quantum jump of a coupled damped driven harmonic oscillator,"The dynamics of the next quantum jump for a qubit [two level system] coupled
to a readout resonator [damped driven harmonic oscillator] is calculated. A
quantum mechanical treatment of readout resonator reveals non exponential short
time behavior which could facilitate detection of the state of the qubit faster
than the resonator lifetime.",2006.11950v1
2020-06-25,Fano resonances in optical spectra of semiconductor quantum wells driven by an oscillating field,"Optical spectra of semiconductor quantum wells driven by an off-resonant
oscillating field are studied theoretically. Due to the dynamical stabilization
effect, the field induces the quasi-stationary electron states confined at
repulsive scatterers and immersed into the continuum of states of conduction
electrons. As a result, the Fano resonances in the spectra of interband optical
transitions appear near the energies of the quasi-stationary states.",2006.14296v3
2020-08-22,Pseudospin resonances reveal synthetic spin-orbit interaction,"We investigate a spin-full double quantum dot (DQD) coupled to the leads in a
pseudospin valve configuration. The interplay of interaction and interference
produces in the stability diagram a rich variety of resonances, modulated by
the system parameters. In presence of ferromagnetic leads and pseudospin
anisotropy, those resonances split, turn into dips and acquire a Fano shape
thus revealing a synthetic spin-orbit coupling induced on the DQD. A set of
rate equations derived for a minimal model captures those features. The model
accurately matches the numerical results obtained for the full system in the
framework of a generalized master equation and calculated within the
cotunneling approximation.",2008.09857v1
2020-08-27,Nutation Resonance in Ferromagnets,"The inertial dynamics of magnetization in a ferromagnet is investigated
theoretically. The analytically derived dynamic response upon microwave
excitation shows two peaks: ferromagnetic and nutation resonances. The exact
analytical expressions of frequency and linewidth of the magnetic nutation
resonance are deduced from the frequency dependent susceptibility determined by
the inertial Landau-Lifshitz-Gilbert equation. The study shows that the
dependence of nutation linewidth on the Gilbert precession damping has a
minimum, which becomes more expressive with increase of the applied magnetic
field.",2008.12221v3
2020-08-28,Kinematical Cusp and Resonance Interpretations of the $X(2900)$,"We examine whether the LHCb vector $ud\bar{c}\bar{s}$ state $X(2900)$ can be
interpreted as a kinematical cusp effect arising from $\bar D^*K^*$ and $\bar
D_1 K^*$ interactions. The production amplitude is modelled as a triangle
diagram with hadronic final state interactions. A satisfactory fit to the
Dalitz plot projection is obtained that leverages the singularities of the
production diagram without the need for $\bar{D}K$ resonances. A somewhat
better fit is obtained if the final state interactions are strong enough to
generate resonances, although the evidence in favour of this scenario is not
conclusive.",2008.12838v2
2020-08-30,Minimum Dielectric-Resonator Mode Volumes,"We show that global lower bounds to the mode volume of a dielectric resonator
can be computed via Lagrangian duality. State-of-the-art designs rely on sharp
tips, but such structures appear to be highly sub-optimal at nanometer-scale
feature sizes, and we demonstrate that computational inverse design offers
orders-of-magnitude possible improvements. Our bound can be applied for
geometries that are simultaneously resonant at multiple frequencies, for
high-efficiency nonlinear-optics applications, and we identify the unavoidable
penalties that must accompany such multiresonant structures.",2008.13241v1
2020-09-02,Design of Gallium Nitride Resonant Cavity Light Emitting Diodes on Si Substrates,"A GaN resonant cavity light emitting diode was built on a GaN-AlN distributed
Bragg reflector grown on a silicon substrate. The electroluminescence output
increased by 2.5 times for a GaN diode coupled to a properly designed resonant
cavity. Theoretical calculations showed that this enhancement could increase up
to four times for transmission through a sem-transparent metal contact design,
up to eight times for a flip-chip design",2009.01768v1
2020-09-07,Computing the Sound of the Sea in a Seashell,"The question of whether there exists an approximation procedure to compute
the resonances of any Helmholtz resonator, regardless of its particular shape,
is addressed. A positive answer is given, and it is shown that all that one has
to assume is that the resonator chamber is bounded and that its boundary is
$\mathcal C^2$. The proof is constructive, providing a universal algorithm
which only needs to access the values of the characteristic function of the
chamber at any requested point.",2009.02956v2
2020-09-26,Mass-in-Mass Lattices with Small Internal Resonators,"We consider the mass-in-mass (MiM) lattice when the internal resonators are
very small. When there are no internal resonators the lattice reduces to a
standard Fermi-Pasta-Ulam-Tsingou (FPUT) system. We show that the solution of
the MiM system, with suitable initial data, shadows the FPUT system for long
periods of time. Using some classical oscillatory integral estimates we can
conclude that the error of the approximation is (in some settings) higher than
one may expect.",2009.12499v1
2020-09-29,The role of spin-flip assisted or orbital mixing tunneling on transport through strongly correlated multilevel quantum dot,"Using the slave boson Kotliar-Ruckenstein approach (SBMFA) for N level
Anderson model, we compare fully symmetric SU(N) Kondo resonances occurring for
spin and orbital conserving tunneling with many-body resonances for the dot
with broken symmetry caused by spin, orbital or full spin-orbital mixing. As a
result of interorbital or spin flip processes new interference paths emerge,
which manifests in the occurrence of antibonding Dicke like and bonding Kondo
like resonances. The analytical expressions for linear conductances and linear
temperature thermopower coefficient for arbitrary N are found.",2009.14122v1
2020-10-01,Floquet prethermalization and Rabi oscillations in optically excited Hubbard clusters,"We study the properties of Floquet prethermal states in two-dimensional
Mott-insulating Hubbard clusters under continuous optical excitation. With
exact-diagonalization simulations, we show that Floquet prethermal states
emerge not only off resonance, but also for resonant excitation, provided a
small field amplitude. In the resonant case, the long-lived quasi-stationary
Floquet states are characterized by Rabi oscillations of observables such as
double occupation and kinetic energy. At stronger fields, thermalization to
infinite temperature is observed. We understand these results in terms of the
optically driven two-site Hubbard model and by means of time-dependent
perturbation theory.",2010.00326v1
2020-10-16,Quasinormal Coupled Mode Theory,"Coupled mode theory (CMT) is a powerful framework for decomposing
interactions between electromagnetic waves and scattering bodies into
resonances and their couplings with power-carrying channels. It has widespread
use in few-resonance, weakly coupled resonator systems across nanophotonics,
but cannot be applied to the complex scatterers of emerging importance. We use
quasinormal modes to develop an exact, ab initio generalized coupled mode
theory from Maxwell's equations. This quasinormal coupled mode theory, which we
denote ""QCMT"", enables a direct, mode-based construction of scattering matrices
without resorting to external solvers or data. We consider canonical scattering
bodies, for which we show that a CMT model will necessarily be highly
inaccurate, whereas QCMT exhibits near-perfect accuracy.",2010.08650v2
2020-10-27,Mitigation of Space-Charge-Driven Resonance and Instability in High-Intensity Linear Accelerators via Beam Spinning,"For modern high-intensity linear accelerators, the well-known envelope
instability and recently reported fourth-order particle resonance impose a
fundamental operational limit (i.e., zero-current phase advance should be less
than 90 deg). Motivated by the stability of spinning flying objects, we propose
a novel approach of using spinning beams to surpass this limit. We discovered
that spinning beams have an intrinsic characteristic that can suppress the
impact of the fourth-order resonance on emittance growth and the associated
envelope instability.",2010.14080v3
2020-11-16,Directional emission of down-converted photons from a dielectric nano-resonator,"Creation of correlated photon pairs is one of the key topics in contemporary
quantum optics. Here, we theoretically describe the generation of photon pairs
in the process of spontaneous parametric down-conversion in a resonant
spherical nanoparticle made of a dielectric material with bulk $\chi^{(2)}$
nonlinearity. We pick the nanoparticle size that satisfies the condition of
resonant eigenmodes described by Mie theory. We reveal that highly directional
photon-pair generation can be observed utilising the nonlinear Kerker-type
effect, and that this regime provides useful polarisation correlations.",2011.07842v1
2020-11-16,Detection of single molecules using stochastic resonance of bistable oligomers,"Our computer simulations have shown that the large-scale conformational
dynamics of a short oligomeric fragment of thermoresponsive polymers resemble
the mechanical movement of nonlinear bistable systems. The oligomers
demonstrate spontaneous vibrations and stochastic resonance activated by the
thermal noise. We have observed reasonable shifts of the spontaneous vibrations
and stochastic resonance modes when attaching a molecular cargo to the
oligomer. All these effects indicate that bistable oligomers may work as
operational units capable of detecting single molecules.",2011.08110v1
2020-11-18,A tunable plasmonic resonator using kinetic 2D inductance and patch capacitance,"We have studied microwave response of a high-mobility two-dimensional
electron system (2DES) contacted by two side electrodes. Using kinetic
inductance of the 2DES and inter-electrode capacitance, we have constructed a
subwavelength 2D plasmonic resonator. We have shown that the resonant frequency
of this circuit can be controlled by 2D electron density, external magnetic
field, or size of the electrodes. This opens up possibilities for using arrays
of plasmonic circuits as tunable components in different frequency ranges.",2011.09142v1
2020-11-19,Coupling spins to nanomechanical resonators: Toward quantum spin-mechanics,"Spin-mechanics studies interactions between spin systems and mechanical
vibrations in a nanomechanical resonator and explores their potential
applications in quantum information processing. In this tutorial, we summarize
various types of spin-mechanical resonators and discuss both the
cavity-QED-like and the trapped-ion-like spin-mechanical coupling processes.
The implementation of these processes using negatively charged nitrogen vacancy
and silicon vacancy centers in diamond is reviewed. Prospects for reaching the
full quantum regime of spin-mechanics, in which quantum control can occur at
the level of both single spin and single phonon, are discussed with an emphasis
on the crucial role of strain coupling to the orbital degrees of freedom of the
defect centers.",2011.09990v1
2020-11-20,Protection of qubits by nonlinear resonances,"We show that quantized superconducting circuits are non-integrable at the
classical level of description, adorned by nonlinear resonances amidst
stochastic sea. The spectral fluctuations of these quasi-integrable systems
exhibit intermediate behaviour between regularity and chaos. The distribution
function of ratios of adjacent spacings, and, nearest-neighbour spacing
distribution functions attest to the occurrence of ""mild chaos"". Based on these
features, we propose criteria for protection of qubits from decoherence which
amounts to choosing the parameters of the system in a way that the system
resides as close as possible to the elliptic point of the primary nonlinear
resonance of the corresponding classical system.",2011.10329v1
2020-11-20,Low coherence-induced resonance in double-layer structures having parity-time symmetry,"We derive simple formulae for the transmittance $T$ and reflectance $R$ of
Gaussian-Schell beams incident upon any stratified dielectric structure by
using second-order classical coherence theory in the space-frequency picture.
The formalism is applied to a particular structure consisting of a
double-layer, with balanced gain and loss, satisfying the parity-time symmetry
conditions. It is shown that sources with a low degree of spatial coherence, on
the order of the wavelength, can induce large resonant peaks in the transmitted
and reflected amplitudes. The resonance peaks vanish as the spatial coherence
increases.",2011.10639v2
2020-11-24,Locate the Source of Resonance-Involved Forced Oscillation in Power Systems Based on Mode Shape Analysis,"This paper proposed a new method to locate the source of forced oscillation
that involves resonance with natural oscillation modes. The new method is based
on comparing the oscillation mode shape of the forced oscillation with that of
the natural oscillation that the forced oscillation resonating with. The
location that has the largest angle difference between the forced oscillation
mode and the natural oscillation mode usually indicates the location of the
driving force in forced oscillations. Some examples in actual U.S. EI system
verified this approach.",2011.12147v2
2021-03-09,Engineering the light coupling between metalens and photonic crystal resonators for robust on-chip microsystems,"We designed an on-chip transformative optic system of a metalens-photonic
crystal resonator metasystem on a foundry compatible silicon photonic platform.
By adjusting the on-chip metalens' focusing length and mode dimension, the
insertion loss between the metalens and the photonic crystal resonator and
waveguide structures are minimized through mode-matching. The micro-system does
not involve any single mode silicon nanowire waveguide, and thus mechanically
robust without any oxide claddings. The proposed microsystem is ideal for
miniaturized chemical and biosensors operating in air or solution environment.",2103.05580v1
2021-03-09,Higher rank quantum-classical correspondence,"For a compact Riemannian locally symmetric space $\Gamma\backslash G/K$ of
arbitrary rank we determine the location of certain Ruelle-Taylor resonances
for the Weyl chamber action. We provide a Weyl-lower bound on an appropriate
counting function for the Ruelle-Taylor resonances and establish a spectral gap
which is uniform in $\Gamma$ if $G/K$ is irreducible of higher rank. This is
achieved by proving a quantum-classical correspondence, i.e. a
1:1-correspondence between horocyclically invariant Ruelle-Taylor resonant
states and joint eigenfunctions of the algebra of invariant differential
operators on $G/K$.",2103.05667v1
2021-03-10,Room temperature cavity electromechanics in the sideband-resolved regime,"We demonstrate a sideband-resolved cavity electromechanical system operating
at room temperature. The mechanical resonator, a strongly pre-stressed silicon
nitride string, is dielectrically coupled to a three-dimensional microwave
cavity made of copper. The electromechanical coupling is characterized by two
measurements, the cavity-induced eigenfrequency shift of the mechanical
resonator and the optomechanically induced transparency. While the former is
dominated by dielectric effects, the latter reveals a clear signature of the
dynamical backaction of the cavity field on the resonator. This unlocks the
field of cavity electromechanics for room temperature applications.",2103.06178v2
2021-03-17,Bulk properties of honeycomb lattices of superconducting microwave resonators,"We have realized different honeycomb lattices for microwave photons in the 4
to 8 GHz band using superconducting spiral resonators. Each lattice comprises a
few hundred sites. Two designs have been studied, one leading to two bands
touching at the Dirac points and one where a gap opens at the Dirac points.
Using a scanning laser technique to image the eigenmodes of this new type of
photonic lattices, we are able to reconstruct their band structure. The
measured bands are in excellent agreement with ab initio models that combine
numerical simulations of the electromagnetic properties of the spiral resonator
and analytical calculations.",2103.09428v1
2021-03-18,Nonlinear circular dichroism in Mie-resonant nanoparticle dimers,"We study nonlinear response of a dimer composed of two identical Mie-resonant
dielectric nanoparticles illuminated normally by a circularly polarized light.
We develop a general theory describing hybridization of multipolar modes of the
coupled nanoparticles, and reveal nonvanishing nonlinear circular dichroism
(CD) in the second-harmonic generation (SHG) signal enhanced by the multipolar
resonances in the dimer provided its axis is oriented under an angle to the
crystalline lattice of the dielectric material. We present experimental results
for this SHG-CD effect obtained for the AlGaAs dimers placed on an engineered
substrate which confirm the basic prediction of our general multipolar
hybridization theory.",2103.10544v1
2021-04-27,Constraining isovector nuclear interactions with giant dipole resonance and neutron skin in $^{208}$Pb from a Bayesian approach,"The remaining uncertainties of isovector nuclear interactions call for
reliable experimental measurements of isovector probes in finite nuclei. Based
on the Bayesian analysis, although the neutron-skin thickness data or the
isovector giant dipole resonance data in $^{208}$Pb can constrain only one
isovector interaction parameter, correlations between other parameters are
built. Using combined data of both the neutron-skin thickness and the isovector
giant dipole resonance helps to constrain significantly all isovector
interaction parameters, thus serves as a useful way in the future analysis.",2104.12985v1
2021-04-27,Semiclassical resonance asymptotics for the delta potential on the half line,"We compute resonance width asymptotics for the delta potential on the
half-line, by deriving a formula for resonances in terms of the Lambert W
function and applying a series expansion. This potential is a simple model of a
thin barrier, motivated by physical problems such as quantum corrals and leaky
quantum graphs.",2104.13356v4
2021-05-03,Coherent Interactions Between Silicon-Vacancy Centers in Diamond,"We report coherent interactions within an ensemble of silicon-vacancy color
centers in diamond. The interactions are ascribed to resonant dipole-dipole
coupling. Further, we demonstrate control over resonant center pairs by using a
driving optical pulse to induce collective, interaction-enabled
Rabi-oscillations in the ensemble. Non-resonant center pairs do not undergo
collective oscillations.",2105.01103v1
2021-05-07,Optomechanical amplification driven by interference of phonon-exciton and phonon-photon couplings,"We study theoretically optomechanical damping and amplification spectra for
vibrations interacting with excitonic polaritons in a zero-dimensional
microcavity. We demonstrate, that the spectra strongly depend on the ratio of
the exciton-phonon and the photon-phonon coupling constants. The interference
between these couplings enables a situation when optomechanical gain exists
either only for a lower polaritonic resonance or only for an upper polaritonic
resonance. Our results provide insight in the optomechanical interactions in
various multi-mode systems, where several resonant oscillators, such as
photons, plasmons, or excitons are coupled to the same vibration mode.",2105.03214v1
2021-05-15,A topological photonic ring-resonator for on-chip channel filters,"A topologically protected ring-resonator formed in valley photonic crystals
is proposed and fabricated on a silicon slab. The unidirectional transmission
and robustness against structure defects of its resonant modes are illustrated.
Coupled with topological waveguides, the topological ring is functioned as
notch and channel-drop filters. The work opens up a new avenue for developing
advanced chip-integrated photonic circuits with attributes of topological
photonics.",2105.07171v1
2021-05-24,Condensate formation in collisionless plasma,"Particle condensates in general magnetic mirror geometries in high
temperature plasma may be caused by a discrete resonance with thermal
ion-acoustic background noise near mirror points. The resonance breaks the
bounce symmetry, temporally locking the particles to the resonant wavelength.
The relevant correlation lengths are the Debye length in parallel direction and
the ion gyroradius in perpendicular direction.",2105.11212v2
2021-06-10,QNMnonreciprocal_resonators: an openly available toolbox for computing the QuasiNormal Modes of nonreciprocal resonators,"QNMnonreciprocal_resonators is an extension (posted in 2021) of the QNMEig
solver of the freeware package MAN. It provides a comprehensive presentation of
the computation and normalization of electromagnetic quasinormal modes (QNMs)
of resonators composed of nonreciprocal materials. It features a theoretical
background on the topic and a COMSOL model that illustrates how to put into
practice the theory on the example of a Yttrium iron garnet wire in a
homogenous background. This document provides the necessary details on how the
model is built so that the interested readers may easily modify it for
computing QNMs of other nonreciprocal resonators.",2106.05502v1
2021-06-28,Magnetic Resonance Force Microscopy with Overlapping Frequencies of Cantilever and Spin,"We have studied theoretically magnetic resonance force microscopy (MRFM) with
a high frequency nanomechanical cantilever when the cantilever frequency
matches the resonant frequency of a single electron spin. Our estimations show
that in this scenario the relative frequency shift of the cantilever can be
much greater than the record MRFM frequency shift achieved in experiments with
a single spin detection. Experimental realization of our proposal could open
the way for fast detection of a single electron spin and even for detection of
a single nuclear spin.",2106.15032v1
2021-07-14,Transitionless quantum driving in spin echo,"Spin echo can be used to refocus random dynamical phases caused by
inhomogeneities in control fields and thereby retain the purity of a spatial
distribution of quantum spins. This technique for accurate spin control is an
essential ingredient in many applications, such as nuclear magnetic resonance,
magnetic resonance imaging, and quantum information processing. Here, we show
how all the elements of a spin echo sequence can be performed at high speed by
means of transitionsless quantum driving. This technique promises accurate
control of rapid quantum spin evolution. We apply the scheme to universal
nonadiabatic geometric single- and two-qubit gates in a nuclear magnetic
resonance setting.",2107.06598v2
2021-07-30,Fine structure of current noise spectra in nanoelectromechanical resonators,"We study frequency dependent noise of a suspended carbon nanotube quantum dot
nanoelectromechanical resonator induced by electron-vibration coupling. By
using rigorous Keldysh diagrammatic technique, we build a formal framework to
connect the vibration properties and the electrical measurement. We find that
the noise power spectrum has a narrow resonant peak at the frequency of
vibrational modes. This fine structure feature disappears due to a coherent
cancellation effect when tuning tunneling barriers to a symmetric point. We
note that measuring the electrical current noise spectra provides an
alternative and ultra-sensitive detection method for determining the damping
and dephasing of the quantum vibration modes.",2107.14788v1
2021-08-07,Resonating Delay Equation,"We propose here a delay differential equation that exhibits a new type of
resonating oscillatory dynamics. The oscillatory transient dynamics appear and
disappear as the delay is increased between zero to asymptotically large delay.
The optimal height of the power spectrum of the dynamical trajectory is
observed with the suitably tuned delay. This resonant behavior contrasts itself
against the general behaviors where an increase of delay parameter leads to the
persistence of oscillations or more complex dynamics.",2108.03347v3
2021-08-07,Résonances Semiclassiques Engendrées par des Croisements de Trajectoires Classiques,"We consider a $2\times2$ system of one-dimensional semiclassical
Schr\""odinger operators with small interactions with respect to the
semiclassical parameter $h$. We study the asymptotics in the semiclassical
limit of the resonances near a non-trapping energy for both corresponding
classical Hamiltonians. We show the existence of resonances of width
$T^{-1}h\log(1/h)$, contrary to the scalar case, under the condition that two
classical trajectories cross and compose a periodic trajectory with period $T$.
omposent une trajectoire p\'eriodique de p\'eriode $T$.",2108.03420v1
2021-08-12,Application of topological resonances in experimental investigation of a Fermi golden rule in microwave networks,"We investigate experimentally a Fermi golden rule in two-edge and five-edge
microwave networks with preserved time reversal invariance. A Fermi golden rule
gives rates of decay of states obtained by perturbing embedded eigenvalues of
graphs and networks. We show that the embedded eigenvalues are connected with
the topological resonances of the analyzed systems and we find the trajectories
of the topological resonances in the complex plane.",2108.05584v1
2021-11-18,Complex absorbing potential method for Stark resonances,"We characterize the resonances of Stark Hamiltonians by the complex absorbing
potential method. Namely, we prove that the Stark resonances are the limit
points of complex eigenvalues of the Stark Hamiltonian with a quadratic complex
absorbing potential when the absorbing coefficient tends to zero. The proof
employs the complex distortion outside a cone introduced in the previous work
by the author. Potentials with local singularities such as the Coulomb
potential are allowed as perturbations.",2111.09554v1
2021-11-18,Antiferromagnetic Resonance Revisited: Dissipative Coupling without Dissipation,"The antiferromagnet is a closed Hermitian system, we find that its
excitations, even in the absence of dissipation, can be viewed as a
non-Hermitian system with dissipative coupling. Consequently, the
antiferromagnetic resonance spectrum does not show the typical level repulsion,
but shows the level attraction -- a characteristic behavior often observed in
non-Hermitian systems. Such behavior is because the antiferromagnetic ground
state is $\mathcal{PT}$-symmetric. This new understanding on antiferromagnetic
resonance also explains the mysterious enhancement of antiferromagnetic damping
rate. Being effectively non-Hermitian, antiferromagnetic magnons can be used
for quantum entanglement generation without introducing a third party like
external pumping.",2111.09682v1
2021-11-23,On Resonant Scattering States in Graphene Circular Quantum Dots,"Due to effect of Klein tunneling two-dimensional graphene quantum dots do not
possess genuine bound states but quasi-bound (resonant tunneling) states only.
We discuss in detail the attempt to describe these states within the framework
of the Dirac pseudo-fermion model for circular dot. We demonstrate explicitly
that introduced earlier the so called ""resonance condition"" corresponds to
inconsistent system of linear equations obtained from matching conditions on
the boundary of the quantum dot when one try to use it for complex energy
values and to the case of total reflection for the energies coincided with the
potential well top.",2111.11824v1
2021-11-13,Microstrip Line Based Complementary Resonant Structure For Dielectric Characterization,"In this work, a complementary resonant structure etched on the ground plane
of a microstrip line is proposed for characterizing dielectric materials. The
resonant sensor is designed to operate in S-band (2 to 4 GHz). The sensor is
designed in an electromagnetic simulator to generate its transmission response,
electric and magnetic field maps. A numerical model of the sensor is
established to extract the electric permittivity of dielectric samples. The
sensor is fabricated on a soft microwave laminate using a rapid
photolithography technique. The electric permittivity values of wood, Teflon,
and RT/duroid 5880LZ are determined by using the sensor. The permittivity
values are found consistent with those available in the literature.",2111.12558v1
2021-12-07,Spontaneous symmetry breaking and the dynamics of three interacting nonlinear optical resonators with gain and loss,"The dynamics of two active nonlinear resonators coupled to a linear resonator
is studied theoretically. Possible stationary states and its dynamical
stability are considered in detail. The spontaneous symmetry breaking is found
and it is shown that this bifurcation results in the formation of asymmetric
states. It is also found that the oscillating states can occur in the system in
a certain range of parameters. The results of the analysis of the stationary
states are confirmed by direct numerical simulations. The possibility of the
switching between different states is also demonstrated by numerical
experiments.",2112.03825v1
2021-12-09,Resonant mode approximation of the scattering matrix of photonic crystal slabs near several Wood-Rayleigh anomalies,"The resonant mode approximation of the scattering matrix is considered for
calculating the optical properties of multilayered periodic structures within
the formalism of the Fourier-modal method for two diffraction thresholds in
close proximity of the spectral-angular range of interest. The developed
approximation opens up possibilities for the fast calculation of the scattering
matrix of these structures when describing the integral characteristics of
spectra and dispersion curves containing high-Q resonances, such as bound
states in the continuum.",2112.05014v2
2021-12-16,Double layered transformation cavities: Crossover between local and global transformations,"We study the resonant modes in double-layered transformation cavities
consisting of inner and outer layer boundaries where the mode intensity is
mainly located inside the inner layer. This is an intermediate design between a
transformation cavity and a cavity in a wholly transformed space of
transformation optics. We demonstrate the crossover between these two extreme
cases as the outer layer of the cavity varies and also explore the properties
of the resonant modes in the cavity. While the near-field patterns of the
resonant modes do not change as the outer layer becomes larger, the Q-factors
approach those of a cavity in the wholly transformed space of transformation
optics, and the far-field patterns are modified.",2112.08661v1
2022-01-11,A semimicroscopic description of Isoscalar Giant Multiple Resonances in medium-mass closed-shell nuclei,"Main properties of isoscalar giant multipole resonances (up to L=3),
including L=0,2 overtones, in medium-mass closed-shell nuclei are described
within the semimicroscopic particle-hole dispersive optical model. Main
properties are characterized by the energy-averaged strength distribution,
projected (one-body) transition density, and probabilities of direct
one-nucleon decay. Calculation results obtained for the parameters of the
mentioned resonances in the 48Ca, 90Zr, and 132Sn nuclei are compared with
available experimental data.",2201.04202v3
2022-01-24,Scattering For three waves Nonlinear Schrödinger System with mass-resonance in 5D,"In this paper, we study the dynamics behavior of the NLS system with three
waves interaction in the energy space $H^1(\mathbb{R}^5) \times
H^1(\mathbb{R}^5)\times H^1(\mathbb{R}^5) $. Inspired by B. Dodson and J.
Murphy in \cite{Dodson2018}, we establish an interaction Morawetz estimate for
the NLS system, together with the criterion which proved by Tao-Dodson--Murphy
we can get the scattering under the ground state in energy space with
mass-resonance. Under the radial assumption, we can remove the mass-resonance
condition.",2201.09408v1
2022-02-21,Excitation of absorbing exceptional points in the time domain,"We analyze the time-domain dynamics of resonators supporting exceptional
points (EPs), at which both the eigenfrequencies and the eigenmodes associated
with perfect capture of an input wave coalesce. We find that a time-domain
signature of the EP is an expansion of the class of waveforms which can be
perfectly captured. We show that such resonators have improved performance for
storage or transduction of energy. They also can be used to convert between
waveforms within this class. We analytically derive these features and
demonstrate them for several examples of coupled optical resonator systems.",2202.10567v2
2022-02-24,Edible Resonators,"The development of green, biodegradable electronics that degrade soon after
their function is accomplished is a significant contribution to healthcare
where edible electronics can be used for diagnosis. An important component of
such systems is a resonator. Here we present the design and development of
inductor-capacitor (LC) circuits based on a form of sugar called isomalt. Using
its low roughness and mechanical properties, we demonstrate resonators that use
capacitors, planar inductors, helical inductors and inductors with an edible
core, all fabricated from isomalt.",2202.13782v1
2022-03-02,Observation of microcavity fine structure,"We observe fine structure in the resonance spectra of optical microcavities.
We identify the polarization-resolved modes in the spectrum and find that
resonance frequencies split in accordance with the theoretical prediction. The
observed fine structure is dominantly caused by an optical spin-orbit coupling
and non-paraxial propagation and reflection. Both effects are intrinsic, i.e.
present in an ideal rotation-symmetric system, and scale inversely proportional
to the mirror radius of curvature. For cavities with a small radius of
curvature, the influence of fine structure on the resonance spectrum is
important and unavoidable and should thus be taken into account.",2203.01200v1
2022-03-09,Evidence of ac-Stark-shifted resonances in intense two-color circularly polarized laser fields,"We report on the appearance of a structure at low energies in the
photo-electron momentum distribution of the hydrogen atom exposed to two-color
counter-rotating bi-circular laser fields. These structures, which arise due to
AC-Stark shifted resonances, break the three-fold symmetry, typical for the
$\omega-2\omega$ bi-circular fields. We discuss the physical origin of this
structure in terms of partial-wave interference between direct ionization
channels and a resonant pathway, that passes through the AC-Stark shifted state
and show how the underlying Rydberg state population depend on the field
strength and pulse duration.",2203.04839v1
2022-03-26,Resonance pressure of electromagnetic radiation on metal nanoparticle,"The influence of the electromagnetic irradiation pressure on a spheroidal
metallic nanoparticle at the frequencies close to the surface plasmon
vibrations has been considered. With the action of the radiation pressure, the
polarizability of metal nanoparticle becomes a tensor quantity. The expressions
for the resonance pressure components for the cases of plane-polarized and
circularly polarized light have been derived. We have demonstrated that the
resonance pressure can substantially depend on the shape of a non-spherical
nanoparticle and its orientation with respect to the direction of light
propagation and the light polarization.",2203.14137v1
2022-03-27,Micromanufacturing of geometrically- and dimensionally-precise molecular single-crystal photonic micro-resonators via focused ion beam milling,"Highly reproducible manufacturing of organic optical crystals with
well-defined geometry and dimension is important to realize industrially
relevant all-organic microelectronic and nanophotonic components, and photonic
integrated circuits. Here, we demonstrate programmed shape and size alteration
of perylene crystal resonators into disk and rectangular geometries using
focused-ion beam milling technique. Due to highly reproducible nature of the
employed technique, the fabricated smaller sized disk and rectangular crystal
resonators displaying shape and size dependent optical modes are suitable for
commercial nanophotonic applications.",2203.14218v1
2022-03-28,Effect of Diffraction on Wigner Distributions of Optical Fields and how to Use It in Optical Resonator Theory. II -- Unstable Resonators,"The second part of the article is devoted to field transfers by diffraction
that are represented by fractional Fourier transformations whose orders are
complex numbers. The corresponding effects on the Wigner distributions
associated with optical fields are still represented by $4\times4$ matrices
operating on the scaled phase-space, but unlike matrices involved in the first
part, those matrices decompose into two matrices that essentially represent
2--dimensional hyperbolic rotations, not elliptical rotations. The result is
applied to the theory of unstable resonators.",2203.14546v1
2022-04-13,Absence of Structure Resonances in SIS100 Tune Quadrant for Heavy Ion Fast Extraction,"The understanding and avoidance of space charge induced resonances is of
utmost importance for long storage times in synchrotrons, as they can lead to
halo generation and subsequent beam loss. This report discusses the absence of
structure resonances for heavy-ion operation in SIS100 in the tune quadrant
foreseen for the fast extraction mode, $18.5 < Q_{x,y} < 19$ . Simulations of
beam losses for the duration of the SIS100 accumulation plateau at nominal
transverse space charge conditions with a maximum tune shift of $\Delta
Q^{SC}_y = -0.3$ supplement the discussion.",2204.06435v1
2022-04-22,Compactness property of the linearized Boltzmann operator for a polyatomic gas undergoing resonant collisions,"In this paper, we investigate a compactness property of the linearized
Boltzmann operator in the context of a polyatomic gas whose molecules undergo
resonant collisions. The peculiar structure of resonant collision rules allows
to tensorize the problem into a velocity-related one, neighbouring the
monatomic case, and an internal energy-related one. Our analysis is based on a
specific treatment of the contributions due to the internal energy of the
molecules. We also propose a geometric variant of Grad's proof of the same
compactness property in the monatomic case.",2204.10551v2
2022-04-26,Relaxation and dynamics of high-stress pre-displaced string resonators,"Pre-displaced micromechanical resonators made from high-stress material give
rise to new rich static and dynamic behavior. Here, an analytical model is
presented to describe the mechanics of such pre-displaced resonators. The
bending and tension energies are derived and a modified Euler-Bernoulli
equation is obtained by applying the least action principle. By projecting the
model onto a cosine shape, the energy landscape is visualized, and the
pre-displacement dependence of stress and frequency is studied
semi-analytically. The analysis is extended with finite-element simulations,
including the mode shape, the role of overhang, and the stress distribution.",2204.13592v1
2022-05-02,Theorem of resonance of Small Volume High Contrast multilayered materials,"The need of mathematically formulate relations between composite materials'
properties and its resonance response is growing. This is due the fast
technological advancement in micro-material manufacturing, present in chips for
instance. In this paper two theorems are presented, providing formulas of
scattering resonance of double-layered and multilayered small volumes in terms
of the coefficient of susceptibility, being high, and the geometric
characteristics. Spectroscopy measurements of the composite medium can exploit
the formula to detect its dimension and susceptibility index.",2205.00674v1
2022-05-16,"Observation of the X17 anomaly in the $^7$Li($p$,$e^+e^-$)$^8$Be direct proton-capture reaction","Angular correlation spectra of $e^+e^-$ pairs produced in the
$^{7}$Li($p$,$\gamma$)$^{8}$Be nuclear reaction have been studied at the sharp
$E_p$= 441 keV resonance as well as at $E_p$= 650 keV, 800 keV and 1100 keV
proton beam energies. The spectra measured at the resonance can be understood
through the M1 internal pair creation process, but in the case of the
off-resonance regions (direct proton capture) significant anomalies were
observed in the $e^+e^-$ angular correlations supporting the X17 hypothetical
particle creation and decay.",2205.07744v1
2022-05-23,Effect of shake-up on the rate of a neutrinoless double electronic capture in $^{164}$Er,"Traditionally double neutrinoless electronic capture is considered as a
resonance process. We have fulfilled shake-off probability calculations,
leading to ionization of the electron shell, in the case of $^{164}$Er.
Allowance for the shake-off removes the requirement of resonance, leading to an
increase of the capture rate. The contribution of the new mechanism increases
the capture rate by a factor of 5.6 compared to the conventional resonance
fluorescence mechanism. It also increases the probability of electron capture
from higher shells, which must be foreseen in an experimental study. Moreover,
effect of the shake-off can potentially expand the list of candidate nuclei for
experiments.",2205.11557v1
2022-06-01,Electrically driven spin resonance with bichromatic driving,"Electrically driven spin resonance (EDSR) is an established tool for
controlling semiconductor spin qubits. Here, we theoretically study a
frequency-mixing variant of EDSR, where two driving tones with different drive
frequencies are applied, and the resonance condition connects the spin Larmor
frequency with the sum of the two drive frequencies. Focusing on flopping-mode
operation, we calculate the parameter dependence of the Rabi frequency and the
Bloch-Siegert shift. A shared-control spin qubit architecture could benefit
from this bichromatic EDSR scheme, as it enables simultaneous single-qubit
gates.",2206.00399v2
2022-06-02,Mechanisms of high harmonic generation in solids,"The long standing issue of separating resonant from non-resonant processes in
extreme nonlinear optics is resolved. The theoretical formalism is applied to
high harmonic generation (HHG) in solids and reveals a deeper view into the
dominant laser and material dependent mechanisms. Mid-infrared driven HHG in
semiconductors is dominated by the resonant interband current. As a result of
the dynamic Stark shift, virtual processes gain in importance in near-infrared
driven HHG in dielectrics. Finally, our analysis identifies limitations of
microscopic one-electron-hole theories.",2206.01042v1
2022-06-06,Optical responses of Fano resonators in non-spectral parametric domains,"Fano resonance observed in various classical and quantum systems features an
asymmetric spectral line shape. For designing nanoresonators for monochromatic
applications, it is beneficial to describe Fano resonance in non-spectral
parametric domains of critical structural parameters. We develop the analytical
model of the parametric Fano profile based on a coupled harmonic oscillator
(CHO) model and theoretically demonstrate its application in describing the
optical response of a chirped waveguided plasmonic crystal (CWPC). The
developed parametric Fano model may find applications in the design of
monochromatic and spectrometer-free nanodevices.",2206.02828v1
2022-06-24,A trace formula for scattering resonances of unbalanced quantum graphs,"Given an unbalanced open quantum graph, we derive a formula relating sums
over its scattering resonances with integrals outside a strip. We deduce lower
bounds on the number of resonances (in bounded regions of the complex
plane),that are independent of the size of the graph. We also deduce partial
results indicating that Benjamini-Schramm convergence of open quantum graphs
should imply convergence of the empirical spectral measures.",2206.12460v2
2022-08-16,Super-Resonant Dark Matter,"We introduce Super-Resonant Dark Matter, a model of self-interacting dark
matter based on the low energy effective theory of supersymmetric QCD. The
structure of the theory ensures a resonant enhancement of the self-interactions
of the low energy mesons, since their mass ratio is set by the number of colors
and flavors. The velocity dependence of the resonantly enhanced
self-interactions allows such theories to accommodate puzzles in small scale
structure that arise from dark matter halos of different sizes. The dark matter
mass is then predicted to be around 3-4 MeV, with its abundance set by
freeze-in via a kinetically mixed dark photon.",2208.07882v1
2022-08-17,Phase stochastic resonance in coherent QKD signal transmission with a crosstalk noise in multicore fiber,"The study considers the new effect of phase stochastic resonance in a linear
system with multiple external signals that can influence quantum communication.
The phase stochastic resonance was shown in a linear co-propagation of the
quantum and multiple classical signals in the multicore fiber of the quantum
channel of Quantum Key Distribution (QKD). The dependence of SNR vs phase noise
of classical signal could have a maximum at a certain range of phase noise
depending on the wavelength of the signals. The results determine the set of
transmission parameters that would produce less interference with the quantum
signal in QKD systems.",2208.08551v1
2022-09-06,The resonance perturbations of the (39991) Iochroma family,"The dynamics of a very young compact asteroid cluster associated with
asteroid 39991 Iochroma is studied. It is shown that Iochroma family lies
between the two three body resonances 3J-1M-3 and 5J 3S-2. In this paper we
have determined the position of these resonances and the boundary between them.
We have included the orbital elements approximations which may be useful in the
future study of the dynamics of the family. Additionally, we report on a new
candidate member, namely asteroid 2016 UT3.",2209.02265v1
2022-09-08,Temporal coupled-mode theory for thermal emission from multiple arbitrarily coupled resonators,"Controlling the spectral response of thermal emitters has become increasingly
important for a range of energy and sensing applications. Conventional
approaches to achieving arbitrary spectrum selectivity in photonic systems have
entailed combining multiple resonantly emissive elements together to achieve a
range of spectral profiles through numerical optimization, with a universal
theoretical framework lacking. Here, we develop a temporal coupled mode theory
for thermal emission from multiple, arbtirarily-coupled resonators. We validate
our theory against numerical simulations of complex two- and three-dimensional
nanophotonic thermal emitters, highlighting the anomalous thermal emission
spectra that can emerge when multiple resonators with arbitrary properties
couple to each other with varying strengths.",2209.03951v1
2022-09-12,Minimally-diffracting quartz for ultra-low temperature surface acoustic wave resonators,"We simulate and experimentally demonstrate the existence of an orientation of
quartz which minimizes diffraction losses in surface acoustic wave (SAW)
resonators at ultra-low temperatures. The orientation is optimized for
applications to quantum technologies which benefit from high mechanical quality
factors, strong electromechanical coupling, and narrow acoustic apertures. We
fabricate narrow aperture SAW resonators on this substrate and measure internal
quality factors greater than 100,000 at mK temperatures.",2209.05501v1
2022-09-26,High temperature spectroscopy of nitrogen vacancy centers in diamond,"We study spectroscopy of negatively charged nitrogen-vacancy center in
diamond at high temperatures under high vacuum conditions. Spin resonances are
studied using optical detection of magnetic resonance (ODMR), and optical
spectroscopy is employed to study radiative transitions. Upon increasing the
temperature the intensity of radiative decay in visible and infra-red
decreased. In addition, the ODMR resonance frequencies were decreased, and the
phonon line emission shifted to higher wavelengths. Fitting the measured
intensity of photo-luminescence with the theoretical predictions of the
Mott-Seitz model yields the value of $0.24 \operatorname{eV}$ for the energy
barrier associated with nonradiative decay.",2209.12558v3
2022-09-28,Sommerfeld enhancement of resonant dark matter annihilation,"The dark matter annihilation cross section can be amplified by orders of
magnitude if the annihilation occurs into a narrow resonance, or if the
dark-matter particles experience a long-range force before annihilation
(Sommerfeld effect). We show that when both enhancements are present they
factorize completely, that is, all long-distance non-factorizable effects
cancel at leading order in the small-velocity and narrow-width expansion. We
then investigate the viability of ``super-resonant'' annihilation from the
coaction of both mechanisms in Standard Model Higgs portal and simplified
MSSM-inspired dark-matter scenarios.",2209.14343v2
2022-10-10,Resonances and Eigenvalues for the Constant Mean Curvature Equation,"In this paper we study resonances and eigenvalues for the nonlinear constant
mean curvature eqn. linearized around the bubbles found by Brezis-Coron. This
nonlinear eqn. is also called a H-system eqn. For degree one bubbles(the degree
relates to a certain winding number) we only find resonances. For higher degree
we prove eigenvalues do occur. Our goal is to eventually obtain dispersive
estimates for the wave eqn. associated to the H-systems eqn. in its linear and
non-linear form, a study of which was initiated by Chanillo-Yung.",2210.04580v1
2022-10-20,Climbing the N-shell resonance ladder of xenon,"The dependency on the excitation energy of ultrafast multi-photon ionization
of xenon by intense, short extreme ultraviolet pulses (XUV) was investigated in
the vicinity of the 4$d$ 'giant' resonance using ion time-of-flight
spectroscopy. The yields of the high charge states of xenon show strong
variations with the excitation energy. With reference to simulated absorption
spectra, we can link the photon energy dependency to resonance structures of
single-electron excitations mainly in the xenon N-shell and purely sequential
multi-photon absorption.",2210.11378v1
2022-10-26,Automated Tour Design in the Saturnian System,"Future missions to Enceladus would benefit from multi-moon tours that
leverage V-infinity on resonant orbits to progressively transfer between moons.
Such ""resonance family hopping"" trajectories present a vast search space for
global optimization due to the different combinations of available resonances
and flyby speeds. The proposed multi-objective tour design algorithm optimizes
entire moon tours from Titan to Enceladus via grid-based dynamic programming,
in which the computation time is significantly reduced by utilizing a database
of V-infinity-leveraging transfers. The result unveils a complete trade space
of the moon tour design to Enceladus in a tractable computation time and global
optimality.",2210.14996v1
2022-10-31,A Wave Packet Approach to Resonant Scattering,"Resonant transmission occurs when constructive interference results in the
complete passage of an incoming wave through an array of barriers. In this
paper we explore such a scenario with one dimensional models. We adopt wave
packets with finite width to illustrate the deterioration of resonance with
decreasing wave packet width, and suggest an approximate wave function for the
transmitted and reflected components, derived from aspects of both the wave
packet and plane wave approaches. A comparison with exact numerical
calculations shows excellent agreement, and provides insight into the
scattering process.",2210.17033v1
2022-11-03,Study on $Λnn$ Bound State and Resonance,"We perform the ab initio no-core shell model (NCSM) calculation to
investigate the bound state problem of the three-body $\Lambda nn$ system in
chiral next-to-next-to-leading-order NN and chiral leading-order YN
interactions. The calculations show that no $\Lambda nn$ bound state exists,
but predict a low-lying $\Lambda nn$ resonant state near the threshold with the
energy of $E_r= 0.124$ MeV and the width of about $\Gamma=1.161$ MeV. In
searching for $\Lambda nn$ resonances, we extend the NCSM calculation to the
continuum state by employing the J-matrix formalism in the scattering theory
with the hyperspherical oscillator basis.",2211.01693v1
2022-11-03,Methods on compositeness and related aspects,"In many physical applications, bound states and/or resonances are observed,
which raises the question whether these states are elementary or composite.
Here we elaborate on several methods for calculating the compositeness $X$ of
bound states and resonances in Quantum Mechanics, and in Quantum Field Theory
by introducing particle number operators. For resonances $X$ is typically
complex and we discuss how to get meaningful results by using certain phase
transformations in the $S$ matrix.",2211.02083v1
2022-11-10,Quantum phase slips in a resonant Josephson junction,"We investigate the consequences of resonant tunneling of Cooper pairs on the
quantum phase slips occurring in a Josephson junction. The amplitude for
quantum tunneling under the Josephson potential barrier is modified by the
Landau-Zener amplitude of adiabatic passage through an Andreev level crossing,
resulting in the suppression of $2\pi$ phase slips. As a consequence, close to
resonance, $4\pi$ phase slips become the dominant tunneling process. We
illustrate this crossover by determining the energy spectrum of a transmon
circuit, showing that a residual charge dispersion persists even at perfect
transparency.",2211.05660v3
2022-12-01,Quantum targeted energy transfer through machine learning tools,"In quantum targeted energy transfer, bosons are transferred from a certain
crystal site to an alternative one, utilizing a nonlinear resonance
configuration similar to the classical targeted energy transfer. We use a novel
computational method based on machine learning algorithms in order to
investigate selectivity as well as efficiency of the quantum transfer in the
context of a dimer and a trimer system. We find that our method identifies
resonant quantum transfer paths that allow boson transfer in unison. The method
is readily extensible to larger lattice systems involving nonlinear resonances.",2212.00556v2
2022-12-06,Resonances in non-universal dipolar collisions,"Scattering resonances due to the dipole-dipole interaction between ultracold
molecules, induced by static or microwave fields, are studied theoretically. We
develop a method for coupled-channel calculations that can efficiently impose
many short-range boundary conditions, defined by a short-range phase shift and
loss probability as in quantum-defect theory. We study how resonances appear as
the short-range loss probability is lowered below the universal unit
probability. This may become realizable for nonreactive ultracold molecules in
blue-detuned box potentials.",2212.03065v3
2022-12-07,Resonant Majorana neutrino effects in $Δ$L=2 four-body hyperon decays,"We computed the $\Sigma^{-}\to n\pi^+e^-\ell^-$ ($\ell=e,\mu$), $\Xi^-\to
\Lambda\pi^+e^-e^-$, and $\Lambda\to p\pi^+e^-e^-$ lepton number violating
(LNV) hyperon decays mediated by a resonant Majorana neutrino. The expected
hyperon production rate of experiments like BES-III of around $10^6-10^8$ may
allow searching for these rare hyperon decays at enough sensitivities. We
illustrate the limits on the new heavy mixing parameters derived from these
hyperon channels and compare them with other LNV meson decays in similar mass
regions of the resonant neutrino state.",2212.03994v1
2022-12-14,Layer stripping approach to reconstruct shape defects in waveguides using locally resonant frequencies,"This article present a new method to reconstruct slowly varying width defects
in 2D waveguides using one-side section measurements at locally resonant
frequencies. At these frequencies, locally resonant modes propagate in the
waveguide up to a ""cut-off"" position. In this particular point, the local width
of the waveguide can be recovered. Given multi-frequency measurements taken on
a section of the waveguide, we perform an efficient layer stripping approach to
recover shape variations slice by slice. It provides an L infinite-stable
method to reconstruct the width of a slowly monotonous varying waveguide. We
validate this method on numerical data and discuss its limits.",2212.07121v1
2022-12-16,Giant optomechanical coupling and dephasing protection with cavity exciton-polaritons,"Electronic resonances can significantly enhance the photon-phonon coupling in
cavity optomechanics, but are normally avoided due to absorption losses and
dephasing by inhomogeneous broadening. We experimentally demonstrate that
exciton-polaritons in semiconductor microcavities enable GHz optomechanics with
single-particle resonant couplings reaching record values in the 10s of MHz
range. Moreover, this resonant enhancement is protected from inhomogeneous
broadening by the Rabi gap. Single-polariton non-linearities and the
optomechanical strong-coupling regime become accessible in this platform.",2212.08269v1
2022-12-19,Distribution of Ruelle resonances for real-analytic Anosov diffeomorphisms,"We prove an upper bound for the number of Ruelle resonances for Koopman
operators associated to real-analytic Anosov diffeomorphisms: in dimension $d$,
the number of resonances larger than $r$ is a $\mathcal{O}(|\log r|^d)$ when
$r$ goes to $0$. For each connected component of the space of real-analytic
Anosov diffeomorphisms on a real-analytic manifold, we prove a dichotomy:
either the exponent $d$ in our bound is never optimal, or it is optimal on a
dense subset. Using examples constructed by Bandtlow, Just and Slipantschuk, we
see that we are always in the latter situation for connected components of the
space of real-analytic Anosov diffeomorphisms on the $2$-dimensional torus.",2212.09881v1
2023-01-31,"Delay, resonance and the Lambert W function","We discuss a new type of delay differential equation that exhibits resonating
transient oscillations. The power spectrum peak of the dynamical trajectory
reaches its maximum height when the delay is suitably tuned. Furthermore, our
analysis of the resonant conditions for this equation has revealed a new
connection between the solutions of the transcendental trigonometric equation
and the Lambert W function. These results offer fresh insights into the
nonlinear dynamics induced by delayed feedback.",2301.13448v3
2023-02-10,Non-resonant cavity for intensity buildup of multiple lasers,"A non-resonant cavity to build up laser intensity is modeled, developed and
tested. It can be used for overlapping multiple lasers of different
wavelengths, increasing their intensities by over an order of magnitude while
maintaining good uniformity. It is simple to set up, has flexible optical
characteristics, and is robust against perturbations. The intensity buildup
requires no resonances, and the wavelength dependence of the performance is
limited only by the mirror coatings. The cavity can be used in applications
requiring a spatially-constrained intensity buildup, for example in atomic and
molecular traps.",2302.04990v1
2023-02-11,Configurational entropy and shape complexity of strange vector kaons in AdS/QCD,"The mass spectrum of strange vector kaons resonances is scrutinized, using
AdS/QCD with a deformed dilaton that arises from the constituent quark masses.
Both the differential configurational entropy and the differential
configurational complexity are computed and used to achieve the mass spectrum
of strange vector kaons resonances with higher radial quantum numbers. This
approach amalgamates AdS/QCD and the experimental mass spectrum of already
detected strange vector kaons in the Particle Data Group, providing a hybrid
technique to study the next generation of strange vector kaons resonances.",2302.05785v1
2023-02-24,Resonant Dynamical Casimir Effect in Waveguide-coupled Qubit Arrays,"We have developed a theory of parametric photon generation in the waveguides
coupled to arrays of qubits with temporally modulated resonance frequencies.
Such generation can be interpreted as a dynamical Casimir effect. We
demonstrate numerically and analytically how the emission directionality and
photon-photon correlations can be controlled by the phases of the modulation.
The emission spectrum is shown to be strongly dependent on the qubit
anharmonicity parameter. Single- and double-excited state resonances have been
identified in the emission spectrum.",2302.12792v1
2023-02-23,Multi Mode (Reflection and Transmission) Operated Dielectric Resonator based Displacement Sensor,"The authors propose a multi mode operated dielectric resonator based
displacement sensor. A cylindrical dielectric resonator is coupled to two 50
ohm microstrip lines to enable the multi mode operating feature. The parameters
like S11 in reflection mode and S21 in transmission mode are sensitive to DR
displacements w.r.to transmission lines. The HFSS is carried out for numerical
analysis and the fabricated sensor prototype is realized with VNA measurement.
Both the HFSS and VNA responses are in good agreement with each other for this
multi mode operation. This reveals the selection of mode freedom to the choice
of operation.",2302.13779v1
2023-02-23,Impact of the Design Parameters on the Microwave Displacement Sensor Performance,"The investigations have been conducted on the involved design parameters to
analyze the behavior of the microwave displacement sensor output
characteristics. To implement this, a dielectric resonator loaded to a
reflection mode operated microstrip line circuit is proposed. For the proposed
reflection mode sensor, the sensor features like resonant frequency, impedance
matching position, sensitivity, and dynamic range are sensitive to the
displacement of DR to microstrip line. The impact of the substrate shape and
size, and resonators geometrical properties are numerically analyzed and
experimentally validated by using VNA. The sensor analysis shows good matching
between both HFSS simulations and VNA measurements.",2302.14614v1
2023-03-14,Reduced resonance schemes and Chen ranks,"The resonance varieties are cohomological invariants that are studied in a
variety of topological, combinatorial, and geometric contexts. We discuss their
scheme structure in a general algebraic setting and introduce various
properties that ensure the reducedness of the associated projective resonance
scheme. We prove an asymptotic formula for the Hilbert series of the associated
Koszul module, then discuss applications to vector bundles on algebraic curves
and to Chen ranks formulas for finitely generated groups, with special emphasis
on K\""ahler and right-angled Artin groups.",2303.07855v1
2023-03-14,Resonance Scattering Treatment with the Windowed Multipole Formalism,"A new method for directly sampling the neutron resonance upscattering effect
is presented. Alternatives have relied on inefficient rejection sampling
techniques or large tabular storage of relative velocities. None of these
approaches, which require pointwise energy data, are particularly well suited
to the windowed multipole cross section representation. The new method called
multipole analytic resonance scattering (MARS) overcomes these limitations by
inverse transform sampling from the target relative velocity distribution where
the cross section is expressed in the multipole formalism. The closed form
relative speed distribution contains a novel special function we deem the
incomplete Faddeeva function: $$ w(z, x) = \frac{i}{\pi} \int_{-\infty}^x
\frac{e^{-t^2} dt}{z-t}. $$ We present the first results on its efficient
numerical evaluation.",2303.08196v1
2023-03-22,Unbounded solutions of periodic systems,"This paper deals with various cases of resonance, which is a fundamental
concept of science and engineering. Specifically, we study the connections
between periodic and unbounded solutions for several classes of equations and
systems. In particular, we extend the classical Massera's theorem, dealing with
periodic systems of the type \[ x'=A(t)x+f(t) \,, \] and clarify that this
theorem deals with a case of resonance. Then we provide instability results for
the corresponding semilinear systems, with the linear part at resonance. We
also use the solution curves developed in [8], [9] to establish the instability
results for pendulum-like equations, and for first-order periodic equations.",2303.12919v1
2023-04-05,Zero field magnetic resonance spectroscopy based on Nitrogen-vacancy centers,"We propose a scheme to have zero field magnetic resonance spectroscopy based
on a nitrogen-vacancy center and investigate the new applications in which
magnetic bias field might disturb the system under investigation. Continual
driving with circularly polarized microwave fields is used to selectively
address one spin state. The proposed method is applied for single molecule
spectroscopy, such as nuclear quadrupole resonance spectroscopy of a $^{11}$B
nuclear spin and the detection of the distance of two hydrogen nuclei in a
water molecule. Our work extends applications of NV centers as a nanoscale
molecule spectroscopy in the zero field regime.",2304.02179v1
2023-04-06,Quantum resonances and analysis of the survival amplitude in the nonlinear Winter's model,"In this paper we show that the typical effects of quantum resonances, namely,
the exponential-type decay of the survival amplitude, continue to exist even
when a nonlinear perturbative term is added to the time-dependent Schroedinger
equation. The difficulty in giving a rigorous and appropriate definition of
quantum resonances by means of the notions already used for linear equations is
also highlighted.",2304.03083v2
2023-04-11,Longitudinal to transversal conversion of mode-locked states in an empty optical resonator,"A longitudinal mode-locked state can be converted to a transverse mode-locked
state by exploiting the spectral and spatial filtering of an empty optical
resonator. Carrier and amplitude modulation sidebands were simultaneously
transmitted by the conversion resonator, yielding phase-locked superpositions
of up to five transverse modes. Equivalently, an amplitude-modulated beam was
converted into a beam that periodically moved across the transverse plane.
Precise control over the spatial beam shape during oscillation was gained by
independently altering the set of transverse modes and their respective powers,
which demonstrated an increased level of control in the generation of
transverse mode-locked states.",2304.05282v1
2023-04-12,Resonance free domain for Schrödinger operators with repulsive potential,"We study resonances for the Schr\""odinger operators with quadratic or
sub-quadratic repulsive potential. In the present paper, we show the
non-existence of resonances in some complex neighborhood of a fixed energy by
employing schemes of Briet-Combes-Duclos and Hunziker and by introducing a
proper distortion based on, but slightly modified, positive commutator method
of Mourre.",2304.05569v4
2023-04-12,Further elements on hypernormal forms of non-resonant double Hopf singularities,"In this paper, we deal with hypernormal forms of non-resonant double Hopf
singularities. We investigate the infinite level normal form classification of
such singularities with nonzero radial cubic part. We provide a normal form
decomposition of normal form vector fields in terms of planar-rotating and
planar-radial vector fields. These facilitate the pattern recognition and
analysis of the corresponding generalized homological maps. This paper is the
first instance of the normal form classification for generic non-resonant
double Hopf singularities without structural symmetry.",2304.05739v1
2023-04-19,Resonant and polarization effects in the processes of quantum electrodynamics in a strong magnetic field,"The monograph considers resonance and polarization effects in quantum
electrodynamics processes that take place in a strong external magnetic field.
A method for analyzing spin-polarization effects has been developed. The
factorization of process cross sections in resonant conditions and the
representation of these cross sections in the form of Breit-Wigner are
considered. The possibility of testing these effects in modern international
projects to test quantum electrodynamics in strong fields is shown.",2304.09484v1
2023-05-09,Configurational entropy and the $N^*(1440)$ Roper resonance in QCD,"The electroexcitation of the ${\cal N}^*(1440)$ Roper resonance, which
defines the first radially excited state of the nucleon, is examined within the
soft-wall AdS/QCD model. Such excited Fock states are characterized by the
leading three-quark component, which determines the main properties of Roper
resonance. The differential configurational entropy (DCE) was used in the
nuclear interaction with a gauge vector field for ${\cal N}^*(1440)$
transition. Comparing the main results with the recent data of the CLAS
Collaboration at JLab shows a good agreement on the accuracy of the computed
data.",2305.05413v2
2023-05-23,Regimes of electronic transport in doped InAs nanowire,"We report on the low temperature measurements of the magnetotransport in
Si-doped InAs quantum wire in the presence of a charged tip of an atomic force
microscope serving as a mobile gate, i.e. scanning gate microscopy (SGM). By
altering the carrier concentration with back gate voltage, we transfer the wire
through several transport regimes: from residual Coulomb blockade to nonlinear
resonance regime, followed by linear resonance regime and, finally, to almost
homogeneous diffusion regime. We demonstrate direct relations between patterns
measured with scanning gate microscopy and spectra of universal conductance
fluctuations. A clear sign of fractal behavior of magnetoconductance dependence
is observed for non-linear and linear resonance transport regimes.",2305.13983v1
2023-05-24,Interactive Neural Resonators,"In this work, we propose a method for the controllable synthesis of real-time
contact sounds using neural resonators. Previous works have used physically
inspired statistical methods and physical modelling for object materials and
excitation signals. Our method incorporates differentiable second-order
resonators and estimates their coefficients using a neural network that is
conditioned on physical parameters. This allows for interactive dynamic control
and the generation of novel sounds in an intuitive manner. We demonstrate the
practical implementation of our method and explore its potential creative
applications.",2305.14867v1
2023-05-26,First observation of electron emission from the DD threshold resonance,"Electron emission in the deuteron-deuteron reaction supporting existence of
the single-particle threshold resonance in 4 He has been observed for the first
time. The measured electron energy spectrum and the electron-proton branching
ratio agree very well with the assumed electron-positron pair creation decay of
the 0+ resonance state to the ground state and the detailed Monte Carlo
simulations of the experimental energy spectrum.",2305.17101v1
2023-06-01,Theoretical Analysis of Quartz Plate Acoustic Wave Resonators and Sensors Using Three-Dimensional Equations of Anisotropic Elasticity or Piezoelectricity,"This is a review of theoretical results from the three-dimensional equations
of anisotropic elasticity or linear piezoelectricity on waves and vibrations in
quartz crystal plates. It covers both the classical results on acoustic wave
resonators and the relatively new applications in acoustic wave sensors. It
discusses the basic thickness modes with various complications due to
electrodes, mass loading, contact with fluids, and air gaps, etc. as well as
the more complicated transversely varying modes. These results are fundamental
for the understanding and design optimization of the widely used quartz crystal
plate resonators and sensors.",2306.00604v1
2023-07-08,Coupling high-overtone bulk acoustic wave resonators via superconducting qubits,"In this work, we present a device consisting of two coupled transmon qubits,
each of which are coupled to an independent high-overtone bulk acoustic wave
resonator (HBAR). Both HBAR resonators support a plethora of acoustic modes,
which can couple to the qubit near resonantly. We first show qubit-qubit
interaction in the multimode system, and finally quantum state transfer where
an excitation is swapped from an HBAR mode of one qubit, to an HBAR mode of the
other qubit.",2307.05544v1
2023-07-25,Effect of resonance magnetic perturbation on edge-core turbulence spreading in a tokamak plasma,"Turbulence spreading from edge to core region with resonance magnetic
perturbation (RMP) is investigated using an electromagnetic Landau-fluid model
in toroidal geometry. When RMP field with appropriate amplitude are employed in
the simulation, long wavelength fluctuations around the resonance surface are
excited due to the forced magnetic reconnection. Strong shear flow at the
magnetic island separatrix are observed, and break the radial elongated vortex
structures of the turbulent fluctuation. The inward flux could be blocked by
this shear flow and the saturation level in the core region declines.",2307.13351v1
2023-08-03,Complete mode conversion for elastic waves reflected by elastic metamaterial slab with double hexapole resonances,"In this study, we investigate the phenomenon of mode conversion in elastic
bulk waves using coupled hexapole resonances. A metamaterial slab is proposed
enabling the complete conversion between longitudinal and transverse modes.
Each unit of the elastic metamaterial slab comprises a pair of scatterers, and
their relative direction is oriented at an oblique angle. The interaction
between the coupled hexapoles and the background results in oblique
displacements, which are responsible for the mode conversion. Moreover, this
conversion exhibits a broader frequency range compared to the quadrupole
resonance. This innovative design significantly broadens the range of
possibilities for developing mode-converting metamaterials.",2308.01969v1
2023-09-06,Complex scaling in finite volume,"Quantum resonances, i.e., metastable states with a finite lifetime, play an
important role in nuclear physics and other domains. Describing this phenomenon
theoretically is generally a challenging task. In this work, we combine two
established techniques to address this challenge. Complex scaling makes it
possible to calculate resonances with bound-state-like methods. Finite-volume
simulations exploit the fact that the infinite-volume properties of quantum
systems are encoded in how discrete energy levels change as one varies the size
of the volume. We apply complex scaling to systems in finite periodic boxes and
derive the volume dependence of states in this scenario, demonstrating with
explicit examples how one can use these relations to infer infinite-volume
resonance energies and lifetimes.",2309.03196v1
2023-09-07,Lower dimensional invariant tori for multi-scale Hamiltonian systems,"The ``Fundamental Theorem"" given by Arnold in [2] asserts the persistence of
full dimensional invariant tori for 2-scale Hamiltonian systems. However,
persistence in multi-scale systems is much more complicated and difficult. In
this paper, we explore the persistence of lower dimensional invariant tori for
multi-scale Hamiltonian systems, which play an important role in dynamics of
resonant Hamiltonian systems. Moreover, using the corresponding results we give
a quasi-periodic Poincar\'{e} Theorem for multi-scale Hamiltonian systems,
i.e., at least $2^{m_0}$ families resonant tori survive small perturbations,
where the integer $m_0$ is the multiplicity of resonance.",2309.03463v1
2023-09-12,Bootstrapping the Stochastic Resonance,"Stochastic resonance is a phenomenon where a noise of appropriate intensity
enhances the input signal strength. In this work, by employing the recently
developed convex optimization methods in the context of dynamical systems and
stochastic processes, we derive rigorous two-sided bounds on the expected power
at the input signal frequency for the prototypical example of stochastic
resonance, the double-well potential with periodic forcing and Gaussian white
noise.",2309.06464v2
2023-09-20,Scaling of self-stimulated spin echoes,"Self-stimulated echoes have recently been reported in the high cooperativity
and inhomogeneous coupling regime of spin ensembles with superconducting
resonators. In this work, we study their relative amplitudes using
echo-silencing made possible by a fast frequency tunable resonator. The highly
anisotropic spin linewidth of Er$^{3+}$ electron spins in the CaWO$_4$ crystal
also allows to study the dependence on spin-resonator ensemble cooperativity.
It is demonstrated that self-stimulated echoes primarily result from a
combination of two large control pulses and the echo preceding it.",2309.11169v1
2023-09-29,Properties of charge-exchange giant spin-dipole resonances in medium-heavy closed-shell parent nuclei: a semimicroscopic description,"The semimicroscopic particle-hole dispersive optical model is adapted for a
description of main properties of charge-exchange giant spin-multipole
resonances in medium-heavy closed-shell parent nuclei. The adapted model is
implemented to evaluating the strength functions, transition densities, and
branching ratios of direct one-nucleon decay for charge-exchange giant
spin-dipole resonances in the ^{48}Ca, ^{90}Zr, ^{132}Sn, and ^{208}Pb parent
nuclei. Some of calculation results are compared with available experimental
data.",2309.17173v3
2023-10-07,Wave scattering by objects made of small particles with pulsating permittivity,"In this work we study the wave scattering by small dispersionless particles
with pulsating refractive index. The scattered fields and their resonance
frequencies are calculated by using scalar approximation and exponentially
time-dependent permittivity.
  In addition, the scattering by single sphere with the pulsating permittivity
is calculated numerically for different regimes of the pulsations.
  Our results suggest that the pulsations of the refractive index of the
scatterer significantly affect the scattered field: existing resonances shift,
additional resonances emerge, and deeps in the light scattering spectrum
appear.",2310.04798v2
2023-10-09,Nonlinear resonance in oscillatory systems with decaying perturbations,"Time-decaying perturbations of nonlinear oscillatory systems in the plane are
considered. It is assumed that the unperturbed systems are non-isochronous and
the perturbations oscillate with an asymptotically constant frequency.
Resonance effects and long-term asymptotic regimes for solutions are
investigated. In particular, the emergence of stable states close to periodic
ones is discussed. By combining the averaging technique and stability analysis,
the conditions on perturbations are described that guarantee the existence and
stability of the phase-locking regime with a resonant amplitude. The results
obtained are applied to the perturbed Duffing oscillator.",2310.05770v1
2023-10-14,The role of pomeron states in the Glueball Resonance Gas,"In this note, we present our recent analyses of the thermodynamic properties
of the glueball resonance gas. We observe that the dominant contribution to the
thermodynamic quantities, such as pressure, trace anomaly, and entropy, is
coming from the free glueball gas with the states of positive charge
conjugation (i.e., pomeron). A comparison of pomeron states obtained from LQCD
and functional methods within the glueball resonance gas model is also
presented.",2310.09606v1
2023-10-22,A global significance evaluation method using simulated events,"In High-Energy Physics experiments it is often necessary to evaluate the
global statistical significance of apparent resonances observed in invariant
mass spectra. One approach to determining significance is to use simulated
events to find the probability of a random fluctuation in the background
mimicking a real signal. As a high school summer project, we demonstrate a
method with Monte Carlo simulated events to evaluate the global significance of
a potential resonance with some assumptions. This method for determining
significance is general and can be applied, with appropriate modification, to
other resonances.",2310.14317v2
2023-11-01,Closed Loop Testing of Microphonics Algorithms Using a Cavity Emulator,"An analog crystal filter based cavity emulator is modified with reverse
biased varactor diodes to provide a tuning range of around 160 Hz. The piezo
drive voltage of the resonance controller is used to detune the cavity through
the bias voltage. A signal conditioning and summing circuit allows the
introduction of microphonics disturbance from a signal source or using real
microphonics data from cavity testing. This setup is used in closed loop with a
cavity controller and resonance controller to study the effectiveness of
resonance control algorithms suitable for superconducting cavities.",2311.00901v2
2023-11-17,Enhancing Electron-Nuclear Resonances by Dynamical Control Switching,"We present a general method to realize resonant coupling between spins even
though their energies are of different scales. Applying the method to the
electron and nuclear spin systems such as a nitrogen-vacancy (NV) center with
its nearby nuclei, we show that a specific dynamical switching of the electron
spin Rabi frequency achieves efficient electron-nuclear coupling, providing a
much stronger quantum sensing signal and dynamic nuclear polarization than
previous methods. This protocol has applications in high-field nanoscale
nuclear magnetic resonances as well as low-power quantum control of nuclear
spins.",2311.10650v1
2023-11-30,Sub-Doppler spectroscopy of the near-UV Cs atom 6S$_{1/2}$-7P$_{1/2}$ transition in a microfabricated vapor cell,"We report on the characterization of sub-Doppler resonances detected by
probing the 6S$_{1/2}$-7P$_{1/2}$ transition of Cs atom at 459 nm in a
microfabricated vapor cell. The dependence of the sub-Doppler resonance
(linewidth, amplitude) on some key experimental parameters, including the laser
intensity and the cell temperature, is investigated. These narrow atomic
resonances are of interest for high-resolution spectroscopy, instrumentation,
and may constitute the basis of a near-UV microcell optical standard.",2311.18459v1
2023-12-01,Optical chiral properties in a large resonant hybrid photonic cluster,"Optical chiral properties of a resonant hybrid photonic crystal (RHPC) are
computed taking into account spin-orbit effect due to light-hole excitons
perfectly confined in 2D quantum wells. The trends of the optical activity,
expressed as a ratio between the absorption intensities of the z and xy
light-hole polaritons, are obtained by computing the optical response in a
rather large N-cluster of elementary cells (N= 34) and for exciton energy, in
resonance with a stationery inflection point (SIP). High values of spin-orbit
interaction (0.7 eV A) produce strong distortions of the optical activity polar
curves that, differently, becomes rather isotropic if the experimental value
(0.14 eV A) is used.",2312.00669v2
2023-12-08,Can we generate bound-states from resonances or virtual states perturbatively?,"We investigate whether it is possible to generate bound-states from
resonances or virtual states through first-order perturbation theory. Using
contact-type potentials as those appeared in pionless effective field theory,
we show that it is possible to obtain negative-energy states by sandwiching a
next-to-leading order (NLO) interaction with the leading-order (LO)
wavefunctions, under the presence of LO resonances or virtual states. However,
at least under the framework of time-independent Schr\""odinger equation and
Hermitian Hamiltonian, there is an inability to create bound-states with
structure similar to those formed by the non-perturbative treatments.",2312.05085v1
2023-12-11,Resonant high-order harmonic generation by indium ions,"High-order harmonic generation in multiphoton ionization regime is studied
theoretically to examine the resonant effects of the generating particle. We
solve the time-dependent Schr\""odinger equation for In+ in the laser field by
expanding the solution in terms of unperturbed eigenstates obtained in the
Hartree-Fock approximation. The intensity enhancement of the high harmonic is
demonstrated under 7-photon resonance with the energy of the transition from
the ground state to the 4d^9 5p ^1P_1 autoionizing state. Attosecond pulse
generation using harmonics of the fifth and higher orders is studied. We find a
train of almost spectral limited pulses with duration of 190 as.",2312.06360v1
2023-12-21,Scattering results for the (1+4) dimensional massive Maxwell-Dirac system under Lorenz gauge condition,"This paper investigates the \emph{massive} Maxwell-Dirac system under the
Lorenz gauge condition in (4+1) dimensional Minkowski space. The focus is on
establishing global existence and scattering results for small solutions on the
weighted Sobolev class. The imposition of the Lorenz gauge condition transforms
the Maxwell-Dirac system into a set of Dirac equations coupled with an
electromagnetic potential derived from five quadratic wave equations. To
achieve a comprehensive understanding of the global solution and its behavior,
we employ various energy estimates based on the space-time resonance argument.
This involves addressing diverse resonance functions arising from the free
Dirac and wave propagators. Additionally, we identify the space-time resonant
sets associated with the \emph{massive} Maxwell-Dirac system.",2312.13621v1
2023-12-22,Enhanced phonon lifetimes with optically controlled single molecules,"We have investigated the phonon dynamics of a single-molecule embedded in a
mechanical resonator made of an organic crystal. The whole system is placed in
an optical resonator within the bad cavity limit. We have found that the
optical control of the molecular population affects the phonon dynamics.
Long-lived phonons are obtained when slowing-down the decay dynamics of the
molecule via modulation of the transition frequency. The discussed results are
also valid for optomechanical setups based on other types of two-level emitters
and mechanical resonators.",2312.14819v1
2024-01-02,Scattering from time-modulated subwavelength resonators,"We consider wave scattering from a system of highly contrasting resonators
with time-modulated material parameters. In this setting, the wave equation
reduces to a system of coupled Helmholtz equations that models the scattering
problem. We consider the one-dimensional setting. In order to understand the
energy of the system, we prove a novel higher-order discrete, capacitance
matrix approximation of the subwavelength resonant quasifrequencies. Further,
we perform numerical experiments to support and illustrate our analytical
results and show how periodically time-dependent material parameters affect the
scattered wave field.",2401.01914v1
2024-01-12,Resonant Solitary States in Complex Networks,"Partially synchronized solitary states occur frequently when a synchronous
system of networked oscillators is perturbed locally. Remarkably, several
asymptotic states of different frequencies can coexist at the same node. Here,
we uncover the mechanism underlying this multistability: The resonant
back-reaction of the network's modes on the solitary can lead to a large energy
transfer between them, and the solitary's frequency adaptation can tune the
system to this resonance. We provide a full analytic analysis of this
mechanism, and show which network structures enable its presence.",2401.06483v1
2024-01-26,Positron supercritical resonances and spontaneous positron creation in slow collisions of heavy nuclei,"We present a theoretical and computational study of positron supercritical
resonances in systems consisting of two highly-charged bare nuclei. The
resonance positions and widths depending on the internuclear separation are
calculated with the help of the complex-scaling generalized pseudospectral
method in modified prolate spheroidal coordinates. The results are applied to
estimate the probability of spontaneous positron creation in slow
U$^{92+}$--U$^{92+}$ and Cm$^{96+}$--Cm$^{96+}$ collisions.",2401.14735v1
2024-02-02,Adiabatic theory of crossing third order resonance and its comparison with experiment at VEPP-4M,"The universal analytical approach was developed to describe the process of
particle slow extraction from a synchrotron using adiabatic crossing the
betatron resonance of the third order. The obtained formulas make it possible
to calculate the time diagrams for the current of the extracted beam ('spill
profile'), taking into account the chromaticity, particle momentum spread and
synchrotron oscillations. On this basis, a method for monochromatization of
extracted beam is indicated. The theory is compared with some results obtained
in the experiment on crossing the third-order resonance at the VEPP-4M storage
ring.",2402.01281v1
2024-02-15,Switching waves-induced broadband Kerr frequency comb in fiber Fabry-Perot resonators,"We report the generation of broadband frequency combs in fiber Fabry-Perot
resonators in the normal dispersion regime enabled by the excitation of
switching waves. We theoretically characterise the process by means of a
transverse linear stability analysis of the Lugiato-Lefever equation, enabling
precise prediction of the switching waves' frequencies. Experimentally, we
employed a pulsed-pump fiber Fabry-Perot resonator operating in the normal
dispersion regime, integrated into an all-fiber experimental setup. The
synchronisation mismatch and the influence of dispersion is thoroughly
discussed, unveiling the potential to generate a frequency comb spanning over
15 THz bandwidth, specifically leveraging a flattened low dispersion cavity.",2402.09777v1
2024-02-19,Exploring Astrophysically-Relevant Superadiabaticity Driven by Non-Resonant Heating in a Laboratory Magnetized Plasma,"The polytropic index of electrons in a magnetized plasma is experimentally
investigated in the presence of external heating and anisotropic work done on
the system by the magnetic field. The measurements clearly demonstrate
localized regions of superadiabatic electrons due to particle acceleration and
energization through non-resonant betatron and Fermi heating processes. In
regions where wave-induced heating through electron cyclotron resonance
dominates, the plasma electrons behave adiabatically. The realization of
superadiabaticity is universal where heating dominates the work done and has
broader implications for energy exchange processes in astrophysically-relevant
plasmas.",2402.11937v1
2024-02-24,Chaotic tides as a solution to the Hyperion problem,"The dynamics of the outer regular satellites of Saturn are driven primarily
by the outward migration of Titan, but several independent constraints on
Titan's migration are difficult to reconcile with the current resonant orbit of
the small satellite Hyperion. We argue that Hyperion's rapid irregular tumbling
greatly increases tidal dissipation with a steep dependence on orbital
eccentricity. Resonant excitation from a migrating Titan is then balanced by
damping in a feedback mechanism that maintains Hyperion's eccentricity without
fine-tuning. The inferred tidal parameters of Hyperion are most consistent with
rapid Titan migration enabled by a resonance lock with an internal mode of
Saturn, but a scenario with only equilibrium dissipation in Saturn is also
possible.",2402.15672v1
2024-02-28,Analysis of double-resonance crossing in adiabatic trapping phenomena for quasi-integrable area-preserving maps with time-dependent exciters,"In this paper, we analyze the adiabatic crossing of a resonance for
Hamiltonian systems when a double-resonance condition is satisfied by the
linear frequency at an elliptic fixed point. We discuss in detail the
phase-space structure on a class of Hamiltonians and area-preserving maps with
an elliptic fixed point in the presence of a time-dependent exciter. Various
regimes have been identified and carefully studied. This study extends results
obtained recently for the trapping and transport phenomena for periodically
perturbed Hamiltonian systems, and it could have relevant applications in the
adiabatic beam splitting in accelerator physics.",2402.18358v1
2024-03-22,Production of dark sector particles via resonant positron annihilation on atomic electrons,"Resonant positron annihilation on atomic electrons provides a powerful method
to search for light new particles coupled to $e^+e^-$. Reliable estimates of
production rates require a detailed characterization of electron momentum
distributions. We describe a general method that harnesses the target material
Compton profile to properly include electron velocity effects in resonant
annihilation cross-sections. We additionally find that high $Z$ atoms can
efficiently act as particle physics accelerators, providing a density of
relativistic electrons that allows to extend by several times the experimental
mass reach.",2403.15387v1
2024-03-27,Resonances crossing effect and quantum sensor of electric fields,"While the phenomenon of the exact crossing of energy levels is a rarely
occurring event, in the case of quantum resonances associated with metastable
states this phenomenon is much more frequent and various scenarios can occur.
When there is an exact crossing of the imaginary parts of the resonances in a
two-level quantum system subject to an external DC electric field, then a
damped beating phenomenon occurs, which is absent if there is no such crossing.
This fact, tested numerically on an explicit one-dimensional model, suggests
the possibility of designing quantum sensors to determine in a very simple way
whether the external field strength has an assigned value or not.",2403.18585v1
2024-03-28,Efficient rational approximation of optical response functions with the AAA algorithm,"We introduce a theoretical framework for the rational approximation of
optical response functions in resonant photonic systems. The framework is based
on the AAA algorithm and further allows to solve the underlying nonlinear
eigenproblems and to efficiently model sensitivities. An adaptive sampling
strategy exploits the predominance of resonances in the physical response. We
investigate a chiral metasurface and show that the chiroptical response on
parameter variations can be accurately modeled in the vicinity of the relevant
resonance frequencies.",2403.19404v1
2024-04-06,Diffusive logistic equation with a non Lipschitz nonlinear boundary condition arising from coastal fishery harvesting: the resonant case,"For bifurcation analysis, we study the positive solution set for a semilinear
elliptic equation of the logistic type, equipped with a sublinear boundary
condition modeling coastal fishery harvesting. This work is a continuation of
the author's previous studies, where certain results were obtained in a non
resonant case, including the existence, uniqueness, multiplicity, and strong
positivity for positive solutions. In this paper, we consider the delicate
resonant case and develop a sort of non standard bifurcation technique at zero
to evaluate the positive solution set depending on a parameter. The nonlinear
boundary condition is not right-differentiable at zero.",2404.04574v1
2024-04-09,Highly reflective and high-$Q$ thin resonant subwavelength gratings,"We theoretically investigate the design of thin subwavelength gratings
possessing high-reflectivity and high-$Q$ resonances when illuminated at normal
incidence by a Gaussian beam. We compare the performances of single-period and
dual-period rectangular gratings using Finite Element Method-based optimization
and predict one to two orders of magnitude improvement in their transmission
loss-linewidth product, which is the relevant figure of merit for e.g. resonant
mirror-based microcavity applications.",2404.06143v1
2023-04-13,Probing magnetic ordering in air stable iron-rich van der Waals minerals,"In the rapidly expanding field of two-dimensional materials, magnetic
monolayers show great promise for the future applications in nanoelectronics,
data storage, and sensing. The research in intrinsically magnetic
two-dimensional materials mainly focuses on synthetic iodide and telluride
based compounds, which inherently suffer from the lack of ambient stability. So
far, naturally occurring layered magnetic materials have been vastly
overlooked. These minerals offer a unique opportunity to explore air-stable
complex layered systems with high concentration of local moment bearing ions.
We demonstrate magnetic ordering in iron-rich two-dimensional phyllosilicates,
focusing on mineral species of minnesotaite, annite, and biotite. These are
naturally occurring van der Waals magnetic materials which integrate local
moment baring ions of iron via magnesium/aluminium substitution in their
octahedral sites. Due to self-inherent capping by silicate/aluminate
tetrahedral groups, ultra-thin layers are air-stable. Chemical
characterization, quantitative elemental analysis, and iron oxidation states
were determined via Raman spectroscopy, wavelength disperse X-ray spectroscopy,
X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy.
Superconducting quantum interference device magnetometry measurements were
performed to examine the magnetic ordering. These layered materials exhibit
paramagnetic or superparamagnetic characteristics at room temperature. At low
temperature ferrimagnetic or antiferromagnetic ordering occurs, with the
critical ordering temperature of 38.7 K for minnesotaite, 36.1 K for annite,
and 4.9 K for biotite. In-field magnetic force microscopy on iron bearing
phyllosilicates confirmed the paramagnetic response at room temperature,
present down to monolayers.",2304.06533v1
1994-04-25,Resonant Oscillations and Tidal Heating in Coalescing Binary Neutron Stars,"Tidal interaction in a coalescing neutron star binary can resonantly excite
the g-mode oscillations of the neutron star when the frequency of the tidal
driving force equals the intrinsic g-mode frequencies. We study the g-mode
oscillations of cold neutron stars using recent microscopic nuclear equations
of state, where we determine self-consistently the sound speed and
Brunt-V\""ais\""al\""a frequency in the nuclear liquid core. The properties of the
g-modes associated with the stable stratification of the core depend
sensitively on the pressure-density relation as well as the symmetry energy of
the dense nuclear matter. The frequencies of the first ten g-modes lie
approximately in the range of $10-100$ Hz. Resonant excitations of these
g-modes during the last few minutes of the binary coalescence result in energy
transfer and angular momentum transfer from the binary orbit to the neutron
star. The angular momentum transfer is possible because a dynamical tidal lag
develops even in the absence of fluid viscosity. However, since the coupling
between the g-mode and the tidal potential is rather weak, the amount of energy
transfer during a resonance and the induced orbital phase error are very small.
Resonant excitations of the g-modes play an important role in tidal heating of
binary neutron stars. Without the resonances, viscous dissipation is effective
only when the stars are close to contact. The resonant oscillations result in
dissipation at much larger orbital separation. The actual amount of tidal
heating depends on the viscosity of the neutron star. Using the microscopic
viscosity, we find that the binary neutron stars are heated to a temperature
$\sim 10^8$ K before they come into contact.",9404062v1
2001-05-25,Relativistic fine structure and resonance effects in electron-ion recombination and excitation of (e + C IV),"Relativistic close coupling calculations are reported for unified electronic
recombination of (e + C IV) including non-resonant and resonant recombination
processes, radiative and dielectronic recombination (RR and DR). Detailed
comparison of the theoretical unified results with two recent experiments on
ion storage rings (Mannervik etal. [1] and Schippers etal. [2]) shows very good
agreement in the entire measured energy region 2s -- 2p with 2pnl resonances.
The results benchmark theory and experiments to uncertainties of ~15%, and show
that the resonant and the background cross sections are not an incoherent sum
of separate RR and DR contributions. The limiting values of the DR cross
sections, as n ---> infinity, are shown to correspond to those due to electron
impact excitation (EIE) at the 2Po_(1/2,3/2) fine structure thresholds,
delineated for the first time. The near-threshold 2s 2S_(1/2) - 2p
2Po_(1/2,3/2) EIE cross sections are also compared with recent experimental
measurements. The demonstrated threshold fine structure and resonance effects
should be of general importance in excitation and recombination of positive
ions.",0105459v2
2001-06-25,Secular interactions between inclined planets and a gaseous disk,"In a planetary system, a secular particle resonance occurs at a location
where the precession rate of a test particle (e.g. an asteroid) matches the
frequency of one of the precessional modes of the planetary system. We
investigate the secular interactions of a system of mutually inclined planets
with a gaseous protostellar disk that may contain a secular nodal particle
resonance. We determine the normal modes of some mutually inclined planet-disk
systems. The planets and disk interact gravitationally, and the disk is
internally subject to the effects of gas pressure, self-gravity, and turbulent
viscosity. The behavior of the disk at a secular resonance is radically
different from that of a particle, owing mainly to the effects of gas pressure.
The resonance is typically broadened by gas pressure to the extent that global
effects, including large-scale warps, dominate. The standard resonant torque
formula is invalid in this regime. Secular interactions cause a decay of the
inclination at a rate that depends on the disk properties, including its mass,
turbulent viscosity, and sound speed. For a Jupiter-mass planet embedded within
a minimum-mass solar nebula having typical parameters, dissipation within the
disk is sufficient to stabilize the system against tilt growth caused by
mean-motion resonances.",0106453v1
2002-04-02,Chaos caused by resonance overlap in the solar neighborhood -- Spiral structure at the Bar's 2:1 outer Lindblad resonance,"We consider the nature of orbits near the solar neighborhood which are
perturbed by local spiral arms and the Milky Way bar. We present a simplified
Hamiltonian model which includes resonant terms from both types of
perturbations and is similar to the forced pendulum. Via numerical integration
of this model we construct Poincare maps to illustrate the nature and stability
of the phase space. We find that resonance overlap is most likely to cause
widespread chaos when the pattern of the spiral structure puts the solar
neighborhood near the 2:1 inner Lindblad resonance (ILR) in the case of a
2-armed pattern, or near the 4:1 ILR in the case of a 4-armed pattern. When
this happens both the quasiperiodic orbits which support the spiral structure
and those that oscillate with the bar are disrupted near the bar's 2:1 outer
Lindblad resonance (OLR). Consequently the pattern speed of spiral structure
which passes through the OLR must be faster than 0.45 times the solar
neighborhood angular rotation rate if it is 2-armed or faster than 0.75 times
this value if it is 4-armed. Alternatively the OLR may form a boundary between
spiral modes at different pattern speeds. In all cases we find that spiral
structure is disrupted by the OLR over a narrow range of radius and the extent
of the orbits aligned perpendicular to the bar at the OLR is limited by the
spiral perturbations.",0204040v1
2002-10-25,Extrasolar Planets in Mean-Motion Resonance: Apses Alignment and Asymmetric Stationary Solutions,"In recent years several pairs of extrasolar planets have been discovered in
the vicinity of mean-motion commensurabilities. In some cases, such as the
Gliese 876 system, the planets seem to be trapped in a stationary solution, the
system exhibiting a simultaneous libration of the resonant angle theta_1 = 2
lambda_2 - lambda_1 - varpi_1 and of the relative position of the pericenters.
  In this paper we analyze the existence and location of these stable
solutions, for the 2/1 and 3/1 resonances, as function of the masses and
orbital elements of both planets. This is undertaken via an analytical model
for the resonant Hamiltonian function. The results are compared with those of
numerical simulations of the exact equations.
  In the 2/1 commensurability, we show the existence of three principal
families of stationary solutions: (i) aligned orbits, in which theta_1 and
varpi_1 - varpi_2 both librate around zero, (ii) anti-aligned orbits, in which
theta_1=0 and the difference in pericenter is 180 degrees, and (iii) asymmetric
stationary solutions, where both the resonant angle and varpi_1 - varpi_2 are
constants with values different of 0 or 180 degrees. Each family exists in a
different domain of values of the mass ratio and eccentricities of both
planets. Similar results are also found in the 3/1 resonance.
  We discuss the application of these results to the extrasolar planetary
systems and develop a chart of possible planetary orbits with apsidal
corotation. We estimate, also, the maximum planetary masses in order that the
stationary solutions are dynamically stable.",0210577v1
2003-08-14,Resonant Trapping of Planetesimals by Planet Migration: Debris Disk Clumps and Vega's Similarity to the Solar System,"This paper describes a model which can explain the observed clumpy structures
of debris disks. Clumps arise because after a planetary system forms its
planets migrate due to angular momentum exchange with the remaining
planetesimals. Outward migration of the outermost planet traps planetesimals
outside its orbit into its resonances and resonant forces cause azimuthal
structure in their distribution. The model is based on numerical simulations of
planets of different masses, Mpl, migrating at different rates, dapl/dt,
through a dynamically cold (e<0.01) planetesimal disk initially at a semimajor
axis a. Trapping probabilities and the resulting azimuthal structures are
presented for a planet's 2:1, 5:3, 3:2, and 4:3 resonances. Seven possible
dynamical structures are identified from migrations defined by mu=Mpl/Mstar and
theta=dapl/dt*sqrt(a/Mstar). Application of this model to the 850um image of
Vega's disk shows its two clumps of unequal brightness can be explained by the
migration of a Neptune-mass planet from 40 to 65AU over 56Myr; tight
constraints are set on possible ranges of these parameters. The clumps are
caused by planetesimals in the 3:2 and 2:1 resonances; the asymmetry arises
because of the overabundance of planetesimals in the 2:1(u) over the 2:1(l)
resonance. The similarity of this migration to that proposed for our own
Neptune hints that Vega's planetary system may be much more akin to the solar
system than previously thought. Predictions are made which would substantiate
this model, such as the orbital motion of the clumpy pattern, the location of
the planet, and the presence of lower level clumps.",0308253v1
2003-10-11,Evolution of Planetary Systems in Resonance,"We study the time evolution of two protoplanets still embedded in a
protoplanetary disk. The results of two different numerical approaches are
presented and compared. In the first approach, the motion of the disk material
is computed with viscous hydrodynamical simulations, and the planetary motion
is determined by N-body calculations including exactly the gravitational forces
exerted by the disk material. In the second approach, only the N-body
integration is performed but with additional dissipative forces included such
as to mimic the effect of the disk torques acting on the disk. This type of
modeling is much faster than the full hydrodynamical simulations, and gives
comparative results provided that parameters are adjusted properly.
  Resonant capture of the planets is seen in both approaches, where the order
of the resonance depends on the properties of the disk and the planets.
Resonant capture leads to a rise in the eccentricity and to an alignment of the
spatial orientation of orbits. The numerical results are compared with the
observed planetary systems in mean motion resonance (Gl 867, HD 82943, and 55
Cnc). We find that the forcing together of two planets by their parent disk
produces resonant configurations similar to those observed, but that
eccentricity damping greater than that obtained in our hydrodynamic simulations
is required to match the GJ 876 observations.",0310321v1
2004-01-09,The (In)Stability of Planetary Systems,"We present results of numerical simulations which examine the dynamical
stability of known planetary systems, a star with two or more planets. First we
vary the initial conditions of each system based on observational data. We then
determine regions of phase space which produce stable planetary configurations.
For each system we perform 1000 ~1 million year integrations. We examine
upsilon And, HD83443, GJ876, HD82943, 47UMa, HD168443, and the solar system
(SS). We find that the resonant systems, 2 planets in a first order mean motion
resonance, (HD82943 and GJ876) have very narrow zones of stability. The
interacting systems, not in first order resonance, but able to perturb each
other (upsilon And, 47UMa, and SS) have broad regions of stability. The
separated systems, 2 planets beyond 10:1 resonance, (we only examine HD83443
and HD168443) are fully stable. Furthermore we find that the best fits to the
interacting and resonant systems place them very close to unstable regions. The
boundary in phase space between stability and instability depends strongly on
the eccentricities, and (if applicable) the proximity of the system to perfect
resonance. In addition to million year integrations, we also examined stability
on ~100 million year timescales. For each system we ran ~10 long term
simulations, and find that the Keplerian fits to these systems all contain
configurations which may be regular on this timescale.",0401171v1
2005-03-27,Modeling the resonant planetary system GJ876,"The two planets about the star GJ 876 appear to have undergone extensive
migration from their point of origin in the protoplanetary disk -- both because
of their close proximity to the star (30 and 60 day orbital periods) and
because of their occupying three stable orbital resonances at the 2:1
mean-motion commensurability. The resonances were most likely established by
converging differential migration of the planets leading to capture into the
resonances. A problem with this scenario is that continued migration of the
system while it is trapped in the resonances leads to orbital eccentricities
that rapidly exceed the observational upper limits of e_1 = 0.31 and e_2 =
0.05. As seen in forced 3-body simulations, lower eccentricities would persist
during migration only for an applied eccentricity damping.
  Here we explore the evolution of the GJ 876 system using two-dimensional
hydrodynamical simulations that include viscous heating and radiative effects.
We find that a hydrodynamic evolution within the resonance, where only the
outer planet interacts with the disk, always rapidly leads to large values of
eccentricities that exceed those observed.
  Only if mass is removed from the disk on a time scale of the order of the
migration time scale (before there has been extensive migration after capture),
as might occur for photoevaporation in the late phases of planet formation, can
we end up with eccentricities that are consistent with the observations.",0503579v1
2006-05-04,The effect of planetary migration on the corotation resonance,"The migration of a planet through a gaseous disc causes the locations of
their resonant interactions to drift and can alter the torques exerted between
the planet and the disc. We analyse the time-dependent dynamics of a
non-coorbital corotation resonance under these circumstances. The ratio of the
resonant torque in a steady state to the value given by Goldreich & Tremaine
(1979) depends essentially on two dimensionless quantities: a dimensionless
turbulent diffusion time-scale and a dimensionless radial drift speed. When the
drift speed is comparable to the libration speed and the viscosity is small,
the torque can become much larger than the unsaturated value in the absence of
migration, but is still proportional to the large-scale vortensity gradient in
the disc. Fluid that is trapped in the resonance and drifts with it acquires a
vortensity anomaly relative to its surroundings. If the anomaly is limited by
viscous diffusion in a steady state, the resulting torque is inversely
proportional to the viscosity, although a long time may be required to achieve
this state. A further, viscosity-independent, contribution to the torque comes
from fluid that streams through the resonant region. In other cases, torque
oscillations occur before the steady value is achieved. We discuss the
significance of these results for the evolution of eccentricity in
protoplanetary systems. We also describe the possible application of these
findings to the coorbital region and the concept of runaway (or type III)
migration. [Abridged]",0605138v1
2006-10-30,On the nature of clumps in debris disks,"The azimuthal substructure observed in some debris disks, as exemplified by
epsilon Eridani, is usually attributed to resonances with embedded planets. In
a standard scenario, the Poynting-Robertson force, possibly enhanced by the
stellar wind drag, is responsible for the delivery of dust from outer regions
of the disk to locations of external mean-motion planetary resonances; the
captured particles then create characteristic ``clumps''. Alternatively, it has
been suggested that the observed features in systems like epsilon Eri may stem
from populations of planetesimals that have been captured in resonances with
the planet, such as Plutinos and Trojans in the solar system. A large fraction
of dust produced by these bodies would stay locked in the same resonance,
creating the dusty clumps. To investigate both scenarios and their
applicability limits for a wide range of stars, planets, disk densities, and
planetesimal families we construct simple analytic models for both scenarios.
In particular, we show that the first scenario works for disks with the pole-on
optical depths below about ~10^{-4}-10^{-5}. Above this optical depth level,
the first scenario will generate a narrow resonant ring with a hardly visible
azimuthal structure, rather than clumps. The efficiency of the second scenario
is proportional to the mass of the resonant planetesimal family, as example, a
family with a total mass of ~0.01 to 0.1 Earth masses could be sufficient to
account for the clumps of epsilon Eridani.",0610871v1
1998-04-20,Time Dependent Resonance Theory,"An important class of resonance problems involves the study of perturbations
of systems having embedded eigenvalues in their continuous spectrum. Problems
with this mathematical structure arise in the study of many physical systems,
e.g. the coupling of an atom or molecule to a photon-radiation field, and Auger
states of the helium atom, as well as in spectral geometry and number theory.
We present a dynamic (time-dependent) theory of such quantum resonances. The
key hypotheses are (i) a resonance condition which holds generically
(non-vanishing of the {\it Fermi golden rule}) and (ii) local decay estimates
for the unperturbed dynamics with initial data consisting of continuum modes
associated with an interval containing the embedded eigenvalue of the
unperturbed Hamiltonian. No assumption of dilation analyticity of the potential
is made. Our method explicitly demonstrates the flow of energy from the
resonant discrete mode to continuum modes due to their coupling. The approach
is also applicable to nonautonomous linear problems and to nonlinear problems.
We derive the time behavior of the resonant states for intermediate and long
times. Examples and applications are presented. Among them is a proof of the
instability of an embedded eigenvalue at a threshold energy under suitable
hypotheses.",9804033v1
1999-07-16,Resonant Raman scattering in NaV2O5 as a probe of its electronic structure,"In order to investigate the origin of the phase transition observed in
NaV$_2$O$_5$, as well as its electronic structure, we have measured Raman
intensities as a function of the laser wavelength above and below the phase
transition temperature. In the polarized Raman spectra at room temperature we
observe resonant enhancement of the 969 $cm^{-1}$ phonon mode when the laser
energy approaches 2.7 eV, presumably related to the (p-d) electron hopping
band, $O_3$($p_y$)-V($d_{xy}$), at 3.2 eV. The 969 $cm^{-1}$ mode originates
from the stretching vibrations along the c-axis involving the V-$O_1$ bonds.
Since an ellipsometric determination of the dielectric function $\epsilon_{cc}$
yields no structure in the 1.7 to 5.5 eV photon energy range, we conclude that
plane bonds couple strongly with the apical oxygens leading to a large Raman
efficiency. In the low-temperature Raman spectra, almost all modes that become
active below the phase transition temperature T$_c$=34 K show resonant
behavior. The most interesting ones, those at 66 and 106 $cm^{-1}$, possibly of
magnetic origin, exhibit a resonant intensity enhancement, approximately by an
order of magnitude, for laser photon energies around 1.85 eV with respect to
2.43 eV. This resonance effect may be associated with a weak absorption band
around 2 eV. Finally, a destructive interference between the resonant and the
nonresonant contribution to the Raman scattering amplitude (i.e. an
antiresonance) is found in the spectra for most of the (bb) low-temperature
modes.",9907237v1
2002-06-30,Traversal times for resonant tunneling,"The tunneling time of particle through given barrier is commonly defined in
terms of ""internal clocks"" which effectively measure the interaction time with
internal degrees of freedom of the barrier. It is known that this definition of
the time scale for tunneling is not unique in the sense that it depends on the
clock used to define it. For the case of resonance tunneling, a particular
choice that in the limit of a high/broad square barrier yields the original
result of Buttiker and Landauer (Phys. Rev. Lett. 1982, 49, 1739) is correlated
to the lifetime of the resonance state. This is illustrated for analytically
solvable one-dimensional double barrier models and for a realistic model of
electron tunneling through a static water barrier. The latter calculation
constitutes a novel application of this concept to a 3-dimensional model, and
the observed structure in the energy dependence of the computed traversal time
reflects the existence of transient tunneling resonances associated with
instantaneous water structures. These models, characterized by the existence of
shape resonances in the barrier, make it possible to examine different internal
clocks that were proposed for measuring tunneling times in situations where a
""clock independent"" intrinsic time scale (the resonance life time) for the
tunneling time exists. It is argued that this time may be used in order to
estimate the relative importance of dynamical barrier processes that affect the
tunneling probability.",0207019v1
2004-08-26,"Orbital ordering, Jahn-Teller distortion, and resonant x-ray scattering in KCuF3","The orbital, lattice, and spin ordering phenomena in KCuF3 are investigated
by means of LDA+U calculations, based on ab-initio pseudopotentials.We examine
the Cu-3d orbital ordering and the associated Jahn-Teller distortion in several
different spin-ordered structures of KCuF3. The ground state is correctly
predicted to be an A-type antiferromagnetic structure, and the calculated
Jahn-Teller distortion agrees also well with experiment. Concerning the orbital
ordering, we find that even for a highly ionic compound such as KCuF3, the
orbital-order parameter is significantly reduced with respect to its nominal
value due to Cu(3d)--F(2p) hybridization. We also calculate the Cu K-edge
resonant x-ray scattering spectra for Bragg reflections associated with orbital
order. Consistent with previous studies, we find that the resonant signal is
dominated by the structural anisotropy in the distribution of the F neighbors
of the resonant Cu atom, and that the Cu-3d orbital ordering has only a minor
influence on the spectra. Our LDA+U results, however, also indicate that a
change in the magnetic structure has a small influence on the Jahn-Teller
distortion, and hence on the resonant spectrum, in the conventional
(room-temperature) crystallographic structure of KCuF3. This may indicate that
the large change observed experimentally in the resonant signal near the N\'eel
temperature is related to a low-temperature structural transformation in KCuF3.",0408568v1
2006-09-28,Association of molecules using a resonantly modulated magnetic field,"We study the process of associating molecules from atomic gases using a
magnetic field modulation that is resonant with the molecular binding energy.
We show that maximal conversion is obtained by optimising the amplitude and
frequency of the modulation for the particular temperature and density of the
gas. For small modulation amplitudes, resonant coupling of an unbound atom pair
to a molecule occurs at a modulation frequency corresponding to the sum of the
molecular binding energy and the relative kinetic energy of the atom pair. An
atom pair with an off-resonant energy has a probability of association which
oscillates with a frequency and time-varying amplitude which are primarily
dependent on its detuning. Increasing the amplitude of the modulation tends to
result in less energetic atom pairs being resonantly coupled to the molecular
state, and also alters the dynamics of the transfer from continuum states with
off-resonant energies. This leads to maxima and minima in the total conversion
from the gas as a function of the modulation amplitude. Increasing the
temperature of the gas leads to an increase in the modulation frequency
providing the best fit to the thermal distribution, and weakens the resonant
frequency dependence of the conversion. Mean-field effects can alter the
optimal modulation frequency and lead to the excitation of higher modes. Our
simulations predict that resonant association can be effective for binding
energies of order $h \times 1$ MHz.",0609725v2
2002-06-20,Gravitational Radiation Damping and the Three-Body Problem,"A model of three-body motion is developed which includes the effects of
gravitational radiation reaction. The radiation reaction due to the emission of
gravitational waves is the only post-Newtonian effect that is included here.
For simplicity, all of the motion is taken to be planar. Two of the masses are
viewed as a binary system and the third mass, whose motion will be a fixed
orbit around the center-of-mass of the binary system, is viewed as a
perturbation. This model aims to describe the motion of a relativistic binary
pulsar that is perturbed by a third mass. Numerical integration of this
simplified model reveals that given the right initial conditions and parameters
one can see resonances. These (m,n) resonances are defined by the resonance
condition, $m\omega=2n\Omega$, where $m$ and $n$ are relatively prime integers
and $\omega$ and $\Omega$ are the angular frequencies of the binary orbit and
third mass orbit, respectively. The resonance condition consequently fixes a
value for the semimajor axis of the binary orbit for the duration of the
resonance; therefore, the binary energy remains constant on the average while
its angular momentum changes during the resonance.",0206059v2
1997-07-28,Study of resonant structure of S-wave amplitudes in pi(-)p->pi(-)pi(+)n measured on polarized target at 17.2 GeV/c in the mass range of 580-1080 MeV,"We have performed a new model independent amplitude analysis of reaction
$\pi^- p \to \pi^- \pi^+ n$ measured at CERN at 17.2 GeV/c on polarized target.
The analysis extends the range of dipion mass from 600--880 MeV used in the
previous study to 580--1080 MeV. Our purpose is to study the role of $f_0(980)$
interference and to better determine the resonance parameters of $\sigma(750)$
resonance from fits to both S-wave amplitudes $|\bar S|^2\Sigma$ and
$|S|^2\Sigma$ with recoil nucleon transversities ``up'' and ``down'',
respectively. This work is the first attempt to determine resonance parameters
of a resonance from Breit-Wigner fits to production amplitudes of opposite
transversity. We used several fitting procedures to understand the resonant
structure of the S-wave amplitudes in this mass range. The simultaneous fit to
$|\bar S|^2\Sigma$ and $|S|^2\Sigma$ with two common $\sigma$ poles yields an
excellent fit with a lower $\chi^2/dpt$ than the separate fits. All amplitudes
are dominated by a $\sigma$ state with $m_\sigma = 786 \pm 24$ MeV and
$\Gamma_\sigma = 130\pm 47$ MeV. All amplitudes receive a weaker contribution
from a narrower $\sigma'$ state with $m_{\sigma'} = 670 \pm 30$ MeV and
$\Gamma_{\sigma'} = 59 \pm 58$ MeV. We propose to identify $\sigma'(670)$ and
$\sigma(786)$ with colour-electric and colour-magnetic modes of lowest mass
scalar gluonium $0^{++} (gg)$.",9707495v1
1998-05-10,Parametric resonance of neutrino oscillations and passage of solar and atmospheric neutrinos through the earth,"We present an exact analytic solution to the neutrino evolution equation in
matter with periodic step-function density profile and discuss in detail the
parametric resonance of neutrino oscillations that can occur in such a system.
Solar and atmospheric neutrinos traversing the earth pass through layers of
alternating density and can therefore experience parametric resonance of their
oscillations. Atmospheric neutrinos can undergo parametrically enhanced
oscillations in the earth when their trajectories deviate from the vertical by
about $26^\circ - 32^\circ$. Solar neutrinos traversing the earth can
experience a strong parametric resonance of their oscillations in a wide range
of zenith angles. If the small mixing angle MSW effect is the solution of the
solar neutrino problem, the oscillations of solar neutrinos crossing the core
of the earth {\em must} undergo strong parametric resonance; this phenomenon
should facilitate significantly the observation of the day-night effect in
oscillations of solar neutrinos. If observed, the enhanced day-night effect for
core crossing neutrinos would therefore confirm both the MSW solution of the
solar neutrino problem and the parametric resonance of neutrino oscillations.",9805272v3
2000-09-22,Unitarity and Interfering Resonances in pipi Scattering and in Pion Production piN->pipiN,"Additivity of Breit-Wigner phases has been proposed to describe interfering
resonances in partial waves in $\pi\pi$ scattering. This assumption leads to an
expression for partial wave amplitudes that involves products of Breit-Wigner
amplitudes. We show that this expression is equivalent to a coherent sum of
Breit-Wigner amplitudes with specific complex coefficients which depend on the
resonance parameters of all contributing resonances. We use analyticity of
$\pi\pi$ partial wave amplitudes to show that they must have the form of a
coherent sum of Breit-Wigner amplitudes with complex coefficients and a complex
coherent background. The assumption of additivity of Breit-Wigner phases
restricts the partial waves to analytical functions with very specific form of
residues of Breit-Wigner poles. We argue that the general form provided by the
analyticity is more appropriate in fits to data to determine resonance
parameters. The partial wave unitarity can be imposed using the modern methods
of constrained optimization. We discuss unitarity and the production amplitudes
in $\pi N\to\pi\pi N$ and use analyticity in the dipion mass variable to
justify the common practice of writing the production amplitudes as a coherent
sum of Breit-Wigner amplitudes with free complex coefficients and a complex
coherent background in fits to mass spectra with interfering resonances.",0009275v2
2004-12-08,"Relativistic resonances: Their masses, widths, lifetimes, superposition, and causal evolution","Whether one starts form the analytic S-matrix definition or the requirement
of gauge parameter independence in renormalization theory, a relativistic
resonance is given by a pole at a complex value s of energy squared. The
complex number s does not define the mass and width separately and this
definition does not lead to interfering Breit-Wigner if two or more resonances
are involved. To accomplish both we invoke the decaying particle aspect of a
resonance and associate to each pole a space of relativistic Gamow kets which
transform irreducibly under causal Poincare transformations. A Gamow state has
an exponential time evolution and one can choose of the many possible width
parameters, that parameter as the width of the relativistic resonance which
equals the inverse lifetime. This uniquely defines the mass and width
parameters for a relativistic resonance. Two or more poles in the same partial
wave are given by the sum of Breit-Wigners in the scattering amplitude and by a
superposition of Gamow vectors with each Gamow vector corresponding to one
Breit-Wigner. In addition to the sum of Breit-Wigners the scattering amplitude
contains a background amplitude representing direct production of the final
state (contact terms).This contact amplitude is associated to a background
vector which is a continuous superposition of Lippmann-Schwinger states.
Omitting this continuum gives the Weisskopf-Wigner approximation.",0412106v2
2003-01-21,"Generalized Wavefunctions for Correlated Quantum Oscillators III: Chaos, Irreversibility","In this third of a series of four articles, we continue the study of the
representations of the hamiltonian dynamical transformations of systems of
correlated quantized oscillators. By our use of generalized wave function
solutions to Schr{\""o}dinger's equation (belonging to a rigged Hilbert space),
and by considering the algebra of observables as a whole, the presence of
Devaney chaos, hyperbolic quasi-invariant measures, complex torus actions,
ergodicity and entropy generation associated to the non-invertible decay of
Gamow vectors and their associated to Breit-Wigner resonances is shown. A weak
(local) form of the second law of thermodynamics is demonstrated through the
decay of resonances. Both correlation formation and decorrelation are
associated with irreversibility and may be associated with entropy growth,
which is due to the dynamical time evolution of resonances. Hilbert space is
the manifold of stationary states. There is a fractal structure associated with
dynamical time evolution of resonances in the space of generalized states, and
the exponential decay of resonances may be identified with quasi-trapping.
Equilibrium states may be regarded as strange attractors with respect to the
dynamical time evolution of resonances.",0301159v3
2004-05-12,The line geometry of resonance varieties,"Let R^1(A,R) be the degree-one resonance variety over a field R of a
hyperplane arrangement A. We give a geometric description of R^1(A,R) in terms
of projective line complexes. The projective image of R^1(A,R) is a union of
ruled varieties, parametrized by neighborly partitions of subarrangements of A.
The underlying line complexes are intersections of special Schubert varieties,
easily described in terms of the corresponding partition. We generalize the
definition and decomposition of R^1(A,R) to arbitrary commutative rings, and
point out the anomalies that arise. In general the decomposition is
parametrized by neighborly graphs, which need not induce neighborly partitions
of subarrangements of A.
  We use this approach to show that the resonance variety of the Hessian
arrangement over a field of characteristic three has a nonlinear component, a
cubic threefold with interesting line structure. This answers a question of A.
Suciu. We show that Suciu's deleted B_3 arrangement has resonance components
over Z_2 that intersect nontrivially. We also exhibit resonant weights over Z_4
supported on the deleted B_3, which has no neighborly partitions. The modular
resonant weights on the deleted B_3 exponentiate to points on the complex torus
which lie on, and determine, the translated 1-torus in the first characteristic
variety.",0405210v2
2006-03-31,Resonances and Spectral Shift Function near the Landau levels,"We consider the 3D Schr\""odinger operator $H = H_0 + V$ where $H_0 =
(-i\nabla - A)^2$, $A$ is a magnetic potential generating a constant magnetic
field of strength $b>0$, and $V$ is a short-range electric potential which
decays superexponentially with respect to the variable along the magnetic
field. We show that the resolvent of $H$ admits a meromorphic extension from
the upper half-plane to an appropriate complex manifold ${\mathcal M}$, and
define the resonances of $H$ as the poles of this meromorphic extension. We
study their distribution near any fixed Landau level $2bq$, $q \in {\mathbb
N}$. First, we obtain a sharp upper bound of the number of resonances in a
vicinity of $2bq$. Moreover, under appropriate hypotheses, we establish
corresponding lower bounds which imply the existence of an infinite number of
resonances, or the absence of resonances in certain sectors adjoining $2bq$.
Finally, we deduce a representation of the derivative of the spectral shift
function (SSF) for the operator pair $(H,H_0)$ as a sum of a harmonic measure
related to the resonances, and the imaginary part of a holomorphic function.
This representation justifies the Breit-Wigner approximation, implies a trace
formula, and provides information on the singularities of the SSF at the Landau
levels.",0603731v2
1999-10-08,Can Doubly Strange Dibaryon Resonances be Discovered at RHIC?,"The baryon-baryon continuum invariant mass spectrum generated from
relativistic nucleus + nucleus collision data may reveal the existence of
doubly-strange dibaryons not stable against strong decay if they lie within a
few MeV of threshold. Furthermore, since the dominant component of these states
is a superposition of two color-octet clusters which can be produced
intermediately in a color-deconfined quark-gluon plasma (QGP), an enhanced
production of dibaryon resonances could be a signal of QGP formation. A total
of eight, doubly-strange dibaryon states are considered for experimental search
using the STAR detector (Solenoidal Tracker at RHIC) at the new Relativistic
Heavy Ion Collider (RHIC). These states may decay to Lambda-Lambda and/or
proton-Cascade-minus, depending on the resonance energy. STAR's large
acceptance, precision tracking and vertex reconstruction capabilities, and
large data volume capacity, make it an ideal instrument to use for such a
search. Detector performance and analysis sensitivity are studied as a function
of resonance production rate and width for one particular dibaryon which can
directly strong decay to proton-Cascade-minus but not Lambda-Lambda. Results
indicate that such resonances may be discovered using STAR if the resonance
production rates are comparable to coalescence model predictions for dibaryon
bound states.",9910007v2
1996-11-15,Resonance contributions to HBT correlation radii,"We study the effect of resonance decays on intensity interferometry for heavy
ion collisions. Collective expansion of the source leads to a dependence of the
two-particle correlation function on the pair momentum K. This opens the
possibility to reconstruct the dynamics of the source from the K-dependence of
the measured HBT radii. Here we address the question to what extent resonance
decays can fake such a flow signal. Within a simple parametrization for the
emission function we present a comprehensive analysis of the interplay of flow
and resonance decays on the one- and two-particle spectra. We discuss in detail
the non-Gaussian features of the correlation function introduced by long-lived
resonances and the resulting problems in extracting meaningful HBT radii. We
propose to define them in terms of the second order q-moments of the correlator
C(q, K). We show that this yields a more reliable characterisation of the
correlator in terms of its width and the correlation strength `lambda' than
other commonly used fit procedures. The normalized fourth-order q-moments
(kurtosis) provide a quantitative measure for the non-Gaussian features of the
correlator. At least for the class of models studied here, the kurtosis helps
separating effects from expansion flow and resonance decays, and provides the
cleanest signal to distinguish between scenarios with and without transverse
flow.",9611031v2
2000-07-11,"Classifying Reported and ""Missing"" Resonances According to Their P and C Properties","The Hilbert space H^3q of the three quarks with one excited quark is
decomposed into Lorentz group representations. It is shown that the quantum
numbers of the reported and ``missing'' resonances fall apart and populate
distinct representations that differ by their parity or/and charge conjugation
properties. In this way, reported and ``missing'' resonances become
distinguishable. For example, resonances from the full listing reported by the
Particle Data Group are accommodated by Rarita-Schwinger (RS) type
representations (k/2,k/2)*[(1/2,0)+(0,1/2)] with k=1,3, and 5, the highest spin
states being J=3/2^-, 7/2^+, and 11/2^+, respectively. In contrast to this,
most of the ``missing'' resonances fall into the opposite parity RS fields of
highest-spins 5/2^-, 5/2^+, and 9/2^+, respectively. Rarita-Schwinger fields
with physical resonances as lower-spin components can be treated as a whole
without imposing auxiliary conditions on them. Such fields do not suffer the
Velo-Zwanziger problem but propagate causally in the presence of
electromagnetic fields. The pathologies associated with RS fields arise
basically because of the attempt to use them to describe isolated spin-J=k+1/ 2
states, rather than multispin-parity clusters. The positions of the observed RS
clusters and their spacing are well explained trough the interplay between the
rotational-like (k/2)(k/2 +1)-rule and a Balmer-like -(k+1)^{-2}-behavior.",0007022v1
2001-10-25,Electromagnetic transition form factors and dilepton decay rates of nucleon resonances,"Relativistic, kinematically complete phenomenological expressions for the
dilepton decay rates of nucleon resonances with arbitrary spin and parity are
derived in terms of the magnetic, electric, and Coulomb transition form
factors. The dilepton decay rates of the nucleon resonances with masses below 2
GeV are estimated using the extended vector meson dominance model for the
transition form factors. The model provides a unified description of the photo-
and electroproduction data, the vector meson decays, and the dilepton decays of
the nucleon resonances. The constraints on the transition form factors from the
quark counting rules are taken into account. The parameters of the model are
fixed by fitting the available photo- and electroproduction data and using
results of the multichannel partial-wave analysis of the $\pi N$ scattering.
Where experimental data are not available, predictions of the non-relativistic
quark models are used as an input. The vector meson coupling constants of the
magnetic, electric, and Coulomb types are determined. The dilepton widths and
the dilepton spectra from decays of nucleon resonances with masses below 2 GeV
are calculated.",0110066v2
2006-09-28,Kaon photoproduction in a multipole approach,"The recently published experimental data on K+Lambda photoproduction by the
SAPHIR, CLAS, and LEPS collaborations are analyzed by means of a multipole
approach. For this purpose the background amplitudes are constructed from
appropriate Feynman diagrams in a gauge-invariant and crossing-symmetric
fashion. The results of our calculation emphasize the lack of mutual
consistency between the SAPHIR and CLAS data previously found by several
independent research groups, whereas the LEPS data are found to be more
consistent with those of CLAS. The use of SAPHIR and CLAS data, individually or
simultaneously, leads to quite different resonance parameters which, therefore,
could lead to different conclusions on ``missing resonances''. Fitting to the
SAPHIR and LEPS data simultaneously indicates that the S_{11}(1650),
P_{13}(1720), D_{13}(1700), D_{13}(2080), F_{15}(1680), and F_{15}(2000)
resonances are required, while fitting to the combination of CLAS and LEPS data
leads alternatively to the P_{13}(1900), D_{13}(2080), D_{15}(1675),
F_{15}(1680), and F_{17}(1990) resonances. Although yielding different results
in most cases, both SAPHIR and CLAS data indicate that the second peak in the
cross sections at W = 1900 MeV originates from the D_{13}(2080) resonance with
a mass between 1911 - 1936 MeV. Furthermore, in contrast to the results of
currently available models and the Table of Particle Properties, both data sets
do not exhibit the need for a P_{11}(1710) resonance. The few data points
available for target asymmetry can not be described by the models proposed in
the present work.",0609077v1
2007-03-29,Nucleon resonances in πN scattering up to energies \sqrt(s) < 2.0 GeV,"A meson-exchange model for pion-nucleon scattering was previously constructed
using a three-dimensional reduction scheme of the Bethe-Salpeter equation for a
model Lagrangian involving \pi, \eta, N, \Delta, \rho, and \sigma fields. We
thereby extend our previous work by including the \eta N channel and all the
\pi N resonances with masses ~ 2 GeV, up to the F waves. The effects of the
\pi\pi N channels are taken into account by introducing an effective width in
the resonance propagators. The extended model gives an excellent fit to both
\pi N phase shifts and inelasticity parameters in all channels up to the F
waves and for energies below 2 GeV. We present a new scheme to extract the
properties of overlapping resonances. The predicted values for the resonance
masses and widths as well as resonance pole positions and residues are compared
to the listing of the Particle Data Group.",0703096v2
1998-10-02,"Parametrically Excited Surface Waves: Two-Frequency Forcing, Normal Form Symmetries, and Pattern Selection","Motivated by experimental observations of exotic standing wave patterns in
the two-frequency Faraday experiment, we investigate the role of normal form
symmetries in the pattern selection problem. With forcing frequency components
in ratio m/n, where m and n are co-prime integers, there is the possibility
that both harmonic and subharmonic waves may lose stability simultaneously,
each with a different wavenumber. We focus on this situation and compare the
case where the harmonic waves have a longer wavelength than the subharmonic
waves with the case where the harmonic waves have a shorter wavelength. We show
that in the former case a normal form transformation can be used to remove all
quadratic terms from the amplitude equations governing the relevant resonant
triad interactions. Thus the role of resonant triads in the pattern selection
problem is greatly diminished in this situation. We verify our general results
within the example of one-dimensional surface wave solutions of the
Zhang-Vinals model of the two-frequency Faraday problem. In one-dimension, a
1:2 spatial resonance takes the place of a resonant triad in our investigation.
We find that when the bifurcating modes are in this spatial resonance, it
dramatically effects the bifurcation to subharmonic waves in the case of
forcing frequencies are in ratio 1/2; this is consistent with the results of
Zhang and Vinals. In sharp contrast, we find that when the forcing frequencies
are in ratio 2/3, the bifurcation to (sub)harmonic waves is insensitive to the
presence of another spatially-resonant bifurcating mode.",9810003v1
1997-09-08,On doubly excited states in negative ions,"Atomic negative ions are fragile quantum systems in which correlation among
the valence electrons plays a very important role. For doubly excited states
correlation becomes dominant. Photodetachment is the process where a negative
ion absorbs a photon and as a consquence ejects the outermost electron. A new
detection scheme has been developed. The residual atom of a photodetachment is
state selectively ionised by resonance ionisation spectroscopy. Investigations
of the photodetachment threshold of tellurium with neutral particle detection
yielded an electron affinity of 1589618(5) m^-1. With state selective detection
the Li(2p) photodetachment threshold was investigated and the electron affinity
was determined to be 498490(17) m^-1. Resonance structure in the Li^-
photodetachment cross section near the Li(3p) threshold has been investigated.
According to an assisting calculation this structure is analogous to the
symmetrically excited intrashell (_3{0}_3^+)^1P^o state in H^-. In He^- the
three doubly excited states, 1s3s4s ^4S, 1s3p^2 ^4P and 1s3p4p ^4P were
investigated. The energy positions of all these resonances [1s3s4s ^4S:
E_0=(2386803.1+-4.2) m^-1, Gamma=160(16) m^-1; 1s3p^2 ^4P: E_0=2.4782(55)x10^6
m^-1, Gamma=40(3)x10^3 m^-1; 1s3p4p ^4P: E_0=2633297(40) m^-1, Gamma=492(35)
m^-1] agree with a recent calculation. The width of the 1s3s4s ^4S resonance
agrees with this calculation, but for the 1s3p^2 ^4P resonance there is a
slight discrepancy and the 1s3p4p ^4P resonance is only half as broad as
predicted.",9709010v2
2003-10-15,Noise spectroscopy of non-linear magneto optical resonances in Rb vapor,"Nonlinear magneto-optical (NMO) resonances occurring for near-zero magnetic
field are studied in Rb vapor using light-noise spectroscopy. With a balanced
detection polarimeter, we observe high contrast variations of the noise power
(at fixed analysis frequency) carried by diode laser light resonant with the
5S$_{1/2}(F=2) \to 5$P$_{1/2}(F=1) $ transition of $^{87}$Rb and transmitted
through a rubidium vapor cell, as a function of magnetic field $B$. A symmetric
resonance doublet of anti-correlated noise is observed for orthogonal
polarizations around $B=0 $ as a manifestation of ground state coherence. We
also observe sideband noise resonances when the magnetic field produces an
atomic Larmor precession at a frequency corresponding to one half of the
analysis frequency. The resonances on the light fluctuations are the
consequence of phase to amplitude noise conversion owing to nonlinear coherence
effects in the response of the atomic medium to the fluctuating field. A
theoretical model (derived from linearized Bloch equations) is presented that
reproduces the main qualitative features of the experimental signals under
simple assumptions.",0310068v3
2004-06-26,An optical fiber-based probe for photonic crystal microcavities,"We review a novel method for characterizing both the spectral and spatial
properties of resonant cavities within two-dimensional photonic crystals (PCs).
An optical fiber taper serves as an external waveguide probe whose micron-scale
field is used to source and couple light from the cavity modes, which appear as
resonant features in the taper's wavelength-dependent transmission spectrum
when it is placed within the cavity's near field. Studying the linewidth and
depth of these resonances as a function of the taper's position with respect to
the resonator produces quantitative measurements of the quality factor Q and
modal volume Veff of the resonant cavity modes. Polarization information about
the cavity modes can be obtained by studying their depths of coupling when the
cavity is probed along different axes by the taper. This fiber-based technique
has been used to measure Q ~ 40,000 and Veff ~ 0.9 cubic wavelengths in a
graded square lattice PC microcavity fabricated in silicon. The speed and
versatility of this fiber-based probe is highlighted, and a discussion of its
applicability to other wavelength-scale resonant elements is given.",0406129v1
2006-06-05,Observation of Strong Coupling between One Atom and a Monolithic Microresonator,"Over the past decade, strong interactions of light and matter at the
single-photon level have enabled a wide set of scientific advances in quantum
optics and quantum information science. This work has been performed
principally within the setting of cavity quantum electrodynamics with diverse
physical systems, including single atoms in Fabry-Perot resonators, quantum
dots coupled to micropillars and photonic bandgap cavities, and Cooper-pairs
interacting with superconducting resonators. Experiments with single, localized
atoms have been at the forefront of these advances with the use of optical
resonators in high-finesse Fabry-Perot configurations. As a result of the
extreme technical challenges involved in further improving the multilayer
dielectric mirror coatings of these resonators and in scaling to large numbers
of devices, there has been increased interest in the development of alternative
microcavity systems. Here we show strong coupling between individual Cesium
atoms and the fields of a high-quality toroidal microresonator. From
observations of transit events for single atoms falling through the resonator's
evanescent field, we determine the coherent coupling rate for interactions near
the surface of the resonator. We develop a theoretical model to quantify our
observations, demonstrating that strong coupling is achieved, with the rate of
coherent coupling exceeding the dissipative rates of the atom and the cavity.
Our work opens the way for investigations of optical processes with single
atoms and photons in lithographically fabricated microresonators. Applications
include the implementation of quantum networks, scalable quantum logic with
photons, and quantum information processing on atom chips.",0606033v2
2006-07-28,Radiation-pressure cooling and optomechanical instability of a micro-mirror,"Recent experimental progress in table-top experiments or gravitational-wave
interferometers has enlightened the unique displacement sensitivity offered by
optical interferometry. As the mirrors move in response to radiation pressure,
higher power operation, though crucial for further sensitivity enhancement,
will however increase quantum effects of radiation pressure, or even jeopardize
the stable operation of the detuned cavities proposed for next-generation
interferometers. The appearance of such optomechanical instabilities is the
result of the nonlinear interplay between the motion of the mirrors and the
optical field dynamics. In a detuned cavity indeed, the displacements of the
mirror are coupled to intensity fluctuations, which modifies the effective
dynamics of the mirror. Such ""optical spring"" effects have already been
demonstrated on the mechanical damping of an electromagnetic waveguide with a
moving wall, on the resonance frequency of a specially designed flexure
oscillator, and through the optomechanical instability of a silica
micro-toroidal resonator. We present here an experiment where a
micro-mechanical resonator is used as a mirror in a very high-finesse optical
cavity and its displacements monitored with an unprecedented sensitivity. By
detuning the cavity, we have observed a drastic cooling of the micro-resonator
by intracavity radiation pressure, down to an effective temperature of 10 K. We
have also obtained an efficient heating for an opposite detuning, up to the
observation of a radiation-pressure induced instability of the resonator.
Further experimental progress and cryogenic operation may lead to the
experimental observation of the quantum ground state of a mechanical resonator,
either by passive or active cooling techniques.",0607205v1
2007-06-14,Stability and Formation of the Resonant System HD 73526,"Based on radial velocity measurements it has been found recently that the two
giant planets detected around the star HD 73526 are in 2:1 resonance. However,
as our numerical integration shows, the derived orbital data for this system
result in chaotic behavior of the giant planets, which is uncommon among the
resonant extrasolar planetary systems.
  We intend to present regular (non-chaotic) orbital solutions for the giant
planets in the system HD 73526 and offer formation scenarios based on combining
planetary migration and sudden perturbative effects such as planet-planet
scattering or rapid dispersal of the protoplanetary disk. A comparison with the
already studied resonant system HD 128311, exhibiting similar behavior, is also
done.
  The new sets of orbital solutions have been derived by the Systemic Console
(www.oklo.org). The stability of these solutions has been investigated by the
Relative Lyapunov indicator, while the migration and scattering effects are
studied by gravitational N-body simulations applying non-conservative forces as
well. Additionally, hydrodynamic simulations of embedded planets in
protoplanetary disks are performed to follow the capture into resonance.
  For the system HD 73526 we demonstrate that the observational radial velocity
data are consistent with a coplanar planetary system engaged in a stable 2:1
resonance exhibiting apsidal corotation. We have shown that, similarly to the
system HD 128311, the present dynamical state of HD 73526 could be the result
of a mixed evolutionary process melting together planetary migration and a
perturbative event.",0706.2128v2
2007-07-03,Dependence of Resonant Absorption Linewidth on Atomic Vapour Column Thickness for D1 Line of Cs Atoms Confined in Nano-Cell,"A new nano-cell with smoothly varying longitudinal thickness of the atomic
vapour layer L in the range of 350 - 5100 nm allowing to study the resonant
absorption of D1 and D2 lines of Cs atoms for thicknesses changing from L =
Lambda/2 to L = 6 Lambda with the step of Lambda/2 (Lambda = 852 nm or 894 nm
are the resonant laser wavelengths) and for different intensities is developed.
It is revealed that for low laser intensities there is narrowing of the
resonant absorption spectrum for the thicknesses L = (2n + 1)Lambda/2 (where n
is an integer) up to L = 7Lambda /2 and broadening of the spectrum for L = n
Lambda. For relatively high laser intensity (>1 mW/cm2), velocity selective
optical pumping/saturated resonances of a reduced absorption (with the
line-width close to the natural one), and centred on the hyperfine transitions
occur when L = n Lambda. The possible application of these resonance peaks is
given. The developed theoretical model describes well the experiment.",0707.0379v5
2007-08-08,Quantifying Resonant Structure in NGC 6946 from Two-dimensional Kinematics,"We study the two-dimensional kinematics of the H-alpha-emitting gas in the
nearby barred Scd galaxy, NGC 6946, in order to determine the pattern speed of
the primary m=2 perturbation mode. The pattern speed is a crucial parameter for
constraining the internal dynamics, estimating the impact velocities of the
gravitational perturbation at the resonance radii, and to set up an
evolutionary scenario for NGC 6946. Our data allows us to derive the best
fitting kinematic position angle and the geometry of the underlying gaseous
disk, which we use to derive the pattern speed using the Tremaine-Weinberg
method. We find a main pattern speed Omega_p=22 km/s/kpc, but our data clearly
reveal the presence of an additional pattern speed Omega_p=47 km/s/kpc in a
zone within 1.25 kpc of the nucleus. Using the epicyclic approximation, we
deduce the location of the resonance radii and confirm that inside the outer
Inner Lindblad Resonance radius of the main oval, a primary bar has formed
rotating at more than twice the outer pattern speed. We further confirm that a
nuclear bar has formed inside the Inner Lindblad Resonance radius of the
primary bar, coinciding with the inner Inner Lindblad Resonance radius of the
large-scale m=2 mode oval.",0708.1081v1
2007-08-31,Rapid Tunneling and Percolation in the Landscape,"Motivated by the possibility of a string landscape, we reexamine tunneling of
a scalar field across single/multiple barriers. Recent investigations have
suggested modifications to the usual picture of false vacuum decay that lead to
efficient and rapid tunneling in the landscape when certain conditions are met.
This can be due to stringy effects (e.g. tunneling via the DBI action), or by
effects arising due to the presence of multiple vacua (e.g. resonance
tunneling). In this paper we discuss both DBI tunneling and resonance
tunneling. We provide a QFT treatment of resonance tunneling using the
Schr\""odinger functional approach. We also show how DBI tunneling for
supercritical barriers can naturally lead to conditions suitable for resonance
tunneling. We argue using basic ideas from percolation theory that tunneling
can be rapid in a landscape where a typical vacuum has multiple decay channels
and discuss various cosmological implications. This rapidity vacuum decay can
happen even if there are no resonance/DBI tunneling enhancements, solely due to
the presence of a large number of decay channels. Finally, we consider various
ways of circumventing a recent no-go theorem for resonance tunneling in quantum
field theory.",0708.4375v3
2007-12-26,Single- and Double-Pion Production in Nucleon Collisions on the Nucleon and on Nuclei -- the ABC Effect and its Possible Origin in a Dibaryonic Resonance,"The ABC effect -- an intriguing low-mass enhancement in the $\pi\pi$
invariant mass spectrum -- is known from inclusive measurements of two-pion
production in nuclear fusion reactions. First exclusive measurements carried
out at CELSIUS-WASA for the fusion reactions leading to d or $^3$He reveal this
effect to be a $\sigma$ channel phenomenon associated with the formation of a
$\Delta\Delta$ system in the intermediate state and combined with a
resonance-like behavior in the total cross section. Together with the
observation that the differential distributions do not change in shape over the
resonance region the features fulfill the criteria of an isoscalar s-channel
resonance in $pn$ and $NN\pi\pi$ systems, if the two emitted nucleons are
bound. It obviously is robust enough to survive in nuclei as a dibaryonic
resonance configuration. In this context also the phenomenon of $N\Delta$
resonances is reexamined.",0712.4125v1
2008-01-12,Resonance Trapping in Protoplanetary Disks. I. Coplanar Systems,"Mean-motion resonances (MMRs) are likely to play an important role both
during and after the lifetime of a protostellar gas disk. We study the
dynamical evolution and stability of planetary systems containing two giant
planets on circular orbits near a 2:1 resonance and closer. We find that by
having the outer planet migrate inward, the two planets can capture into either
the 2:1, 5:3, or 3:2 MMR. We use direct numerical integrations of ~1000 systems
in which the planets are initially locked into one of these resonances and
allowed to evolve for up to ~10^7 yr. We find that the final eccentricity
distribution in systems which ultimately become unstable gives a good fit to
observed exoplanets. Next, we integrate ~500 two-planet systems in which the
outer planet is driven to continuously migrate inward, resonantly capturing the
inner; the systems are evolved until either instability sets in or the planets
reach the star. We find that although the 5:3 resonance rapidly becomes
unstable under migration, the 2:1 and 3:2 are very stable. Thus the lack of
observed exoplanets in resonances closer than 2:1, if it continues to hold up,
may be a primordial signature of the planet formation process.",0801.1926v2
2008-04-15,Resonant soft x-ray scattering from stepped surfaces of SrTiO3,"We studied the resonant diffraction signal from stepped surfaces of SrTiO3 at
the Ti 2p -> 3d (L2,3) resonance in comparison with x-ray absorption (XAS) and
specular reflectivity data. The steps on the surface form an artificial
superstructure suited as a model system for resonant soft x-ray diffraction. A
small step density on the surface is sufficient to produce a well defined
diffraction peak, showing the high sensitivity of the method. At larger
incidence angles, the resonant diffraction spectrum from the steps on the
surface resembles the spectrum for specular reflectivity. Both deviate from the
XAS data in the relative peak intensities and positions of the peak maxima. We
determined the optical parameters of the sample across the resonance and found
that the differences between the XAS and scattering spectra reflect the
different quantities probed in the different signals. When recorded at low
incidence or detection angles, XAS and specular reflectivity spectra are
distorted by the changes of the angle of total reflection with energy. Also the
step peak spectra, though less affected, show an energy shift of the peak
maxima in grazing incidence geometry.",0804.2461v1
2008-10-15,The Detectability of Exo-Earths and Super-Earths Via Resonant Signatures in Exozodiacal Clouds,"Directly imaging extrasolar terrestrial planets necessarily means contending
with the astrophysical noise of exozodiacal dust and the resonant structures
created by these planets in exozodiacal clouds. Using a custom tailored hybrid
symplectic integrator we have constructed 120 models of resonant structures
created by exo-Earths and super-Earths on circular orbits interacting with
collisionless steady-state dust clouds around a Sun-like star. Our models
include enough particles to overcome the limitations of previous simulations
that were often dominated by a handful of long-lived particles, allowing us to
quantitatively study the contrast of the resulting ring structures. We found
that in the case of a planet on a circular orbit, for a given star and dust
source distribution, the morphology and contrast of the resonant structures
depend on only two parameters: planet mass and $\sqrt{a_{\rm p}}/\beta$, where
$a_{\rm p}$ is the planet's semi-major axis and $\beta$ is the ratio of
radiation pressure force to gravitational force on a grain. We constructed
multiple-grain-size models of 25,000 particles each and showed that in a
collisionless cloud, a Dohnanyi crushing law yields a resonant ring whose
optical depth is dominated by the largest grains in the distribution, not the
smallest. We used these models to estimate the mass of the lowest-mass planet
that can be detected through observations of a resonant ring for a variety of
assumptions about the dust cloud and the planet's orbit. Our simulations
suggest that planets with mass as small as a few times Mar's mass may produce
detectable signatures in debris disks for semi-major axes greater than 10 AU.",0810.2702v1
2008-10-22,"Mean Motion Resonances in Extrasolar Planetary Systems with Turbulence, Interactions, and Damping","This paper continues previous work on the effects of turbulence on mean
motion resonances in extrasolar planetary systems. Turbulence is expected to
arise in the disks that form planets, and these fluctuations act to compromise
resonant configurations. This paper extends previous work by considering how
interactions between the planets and possible damping effects imposed by the
disk affect the outcomes. These physical processes are studied using three
approaches: numerical integrations of the 3-body problem with additional
forcing due to turbulence, model equations that reduce the problem to
stochastically driven oscillators, and Fokker-Planck equations that describe
the time evolution of an ensemble of systems. With this combined approach, we
elucidate the physics of how turbulence can remove extrasolar planetary systems
from mean motion resonance. As expected, systems with sufficiently large
damping (dissipation) can maintain resonance, in spite of turbulent forcing. In
the absence of strong damping, ensembles of these systems exhibit two regimes
of behavior, where the fraction of the bound states decreases as a power-law or
as an exponential. Both types of behavior can be understood through the model
developed herein. For systems with weak interactions between planets, the model
reduces to a stochastic pendulum, and the fraction of bound states decreases as
a power-law. For highly interactive systems, the dynamics are more complicated
and the fraction of bound states decreases exponentially. We show how planetary
interactions lead to drift terms in the Fokker-Planck equation and account for
this exponential behavior. In addition to clarifying the physical processes
involved, this paper strengthens the finding that turbulence implies that mean
motions resonances should be rare.",0810.4076v1
2008-12-19,Modified effective-range theory for low energy e-N2 scattering,"We analyze the low-energy e-N2 collisions within the framework of the
Modified-Effective Range Theory (MERT) for the long-range potentials, developed
by O'Malley, Spruch and Rosenberg [Journal of Math. Phys. 2, 491 (1961)]. In
comparison to the traditional MERT we do not expand the total cross-section in
the series of the incident momentum \hbar k, but instead we apply the exact
analytical solutions of the Schroedinger equation for the long-range
polarization potential, as proposed in the original formulation of O'Malley et
al. This extends the applicability of MERT up to few eV regime, as we confirm
using some simplified model potential of the electron-molecule interaction. The
parameters of the effective-range expansion (i.e. the scattering length and the
effective range) are determined from experimental, integral elastic cross
sections in the 0.1 - 1.0 eV energy range by fitting procedure. Surprisingly,
our treatment predicts a shape resonance that appears slightly higher than
experimentally well known resonance in the total cross section. Agreement with
the experimentally observed shape-resonance can be improved by assuming the
position of the resonance in a given partial wave. Influence of the quadrupole
potential on resonances is also discussed: we show that it can be disregarded
for N2. In conclusion, the modified-effective range formalism treating the
long-range part of the potential in an exact way, reproduces well both the very
low-energy behavior of the integral cross section as well as the presence of
resonances in the few eV range.",0812.3793v1
2009-03-03,Detailed studies of non-linear magneto-optical resonances at D1 excitation of Rb-85 and Rb-87 for partially resolved hyperfine F-levels,"Experimental signals of non-linear magneto-optical resonances at D1
excitation of natural rubidium in a vapor cell have been obtained and described
with experimental accuracy by a detailed theoretical model based on the optical
Bloch equations. The D1 transition of rubidium is a challenging system to
analyze theoretically because it contains transitions that are only partially
resolved under Doppler broadening. The theoretical model took into account all
nearby transitions, the coherence properties of the exciting laser radiation,
and the mixing of magnetic sublevels in an external magnetic field and also
included averaging over the Doppler profile. Great care was taken to obtain
accurate experimental signals and avoid systematic errors. The experimental
signals were reproduced very well at each hyperfine transition and over a wide
range of laser power densities, beam diameters, and laser detunings from the
exact transition frequency. The bright resonance expected at the F_g=1 -->
F_e=2 transition of Rb-87 has been observed. A bright resonance was observed at
the F_g=2 --> F_e=3 transition of Rb-85, but displaced from the exact position
of the transition due to the influence of the nearby F_g=2 --> F_e=2
transition, which is a dark resonance whose contrast is almost two orders of
magnitude larger than the contrast of the bright resonance at the F_g=2 -->
F_e=3 transition. Even in this very delicate situation, the theoretical model
described in detail the experimental signals at different laser detunings.",0903.0524v1
2009-06-08,Ultrastrong coupling regime of cavity QED with phase-biased flux qubits,"We theoretically study a circuit QED architecture based on a superconducting
flux qubit directly coupled to the center conductor of a coplanar waveguide
transmission-line resonator. As already shown experimentally [Abdumalikov et
al. Phys. Rev. B 78, 180502 (2008)], the strong coupling regime of cavity QED
can readily be achieved by optimizing the local inductance of the resonator in
the vicinity of the qubit. In addition to yielding stronger coupling with
respect to other proposals for flux qubit based circuit QED, this approach
leads to a qubit-resonator coupling strength g which does not scale as the area
of the qubit but is proportional to the total inductance shared between the
resonator and the qubit. Strong coupling can thus be attained while still
minimizing sensitivity to flux noise. Finally, we show that by taking advantage
of the the large kinetic inductance of a Josephson junction in the center
conductor of the resonator can lead to coupling energies of several tens of
percent of the resonator frequency, reaching the ultrastrong coupling regime of
cavity QED where the rotating-wave approximation breaks down. This should allow
an on-chip implementation of the E x B Jahn-Teller model.",0906.1383v2
2009-06-24,Resonant enhancement of nuclear reactions as a possible solution to the cosmological lithium problem,"There is a significant discrepancy between the current theoretical prediction
of the cosmological lithium abundance, mostly produced as Be7 during the Big
Bang, and its observationally inferred value. We investigate whether the
resonant enhancement of Be7 burning reactions may alleviate this discrepancy.
We identify one narrow nuclear level in B9, E_{5/2^+} \simeq 16.7 MeV that is
not sufficiently studied experimentally, and being just \sim 200 keV above the
Be7+d threshold, may lead to the resonant enhancement of Be7(d,\gamma)B9 and
Be7(d,p)\alpha\alpha reactions. We determine the relationship between the
domain of resonant energies E_r and the deuterium separation width \Gamma_d
that results in the significant depletion of the cosmological lithium abundance
and find that (E_r, ~\Gamma_{d}) \simeq (170-220,~10-40) keV can eliminate
current discrepancy. Such a large width at this resonant energy can be only
achieved if the interaction radius for the deterium entrance channel is very
large, a_{27} \ge 9 fm. Our results also imply that before dedicated nuclear
experimental and theoretical work is done to clarify the role played by this
resonance, the current conservative BBN prediction of lithium abundance should
carry significantly larger error bars, [Li7/H]_{\rm BBN} = (2.5-6)\times
10^{-10}.",0906.4373v1
2009-07-15,"Complex resonance frequencies of a finite, circular radiating duct with an infinite flange","Radiation by solid or fluid bodies can be characterized by resonance modes.
They are complex, as well as resonance frequencies, because of the energy loss
due to radiation. For ducts, they can be computed from the knowledge of the
radiation impedance matrix. For the case of a flanged duct of finite length
radiating on one side in an infinite medium, the expression of this matrix was
given by Zorumski, using a decomposition in duct modes. In order to calculate
the resonance frequencies, the formulation used in Zorumski's theory must be
modified as it is not valid for complex frequencies. The analytical development
of the Green's function in free space used by Zorumski depends on the integrals
of Bessel functions which become divergent for complex frequencies. This paper
proposes first a development of the Green's function which is valid for all
frequencies. Results are applied to the calculation of the complex resonance
frequencies of a flanged duct, by using a formulation of the internal pressure
based upon cascade impedance matrices. Several series of resonance modes are
found, each series being shown to be related to a dominant duct mode. Influence
of higher order duct modes and the results for several fluid densities is
presented and discussed.",0907.2513v2
2009-09-01,Multichannel calculation of excited vector $φ$ resonances and the $φ(2170)$,"A multichannel calculation of excited $J^{PC}=1^{--}$ $\phi$ states is
carried out within a generalization of the Resonance-Spectrum Expansion, which
may shed light on the classification of the $\phi(2170)$ resonance, discovered
by BABAR and originally denoted X(2175). In this framework, a complete spectrum
of bare $s\bar{s}$ states is coupled to those OZI-allowed decay channels that
should be most relevant for the considered energy range. The included $S$- and
$P$-wave two-meson channels comprise the lowest pseudoscalar, vector, scalar,
and axial-vector mesons, while in the $q\bar{q}$ sector both the $^{3}S_1$ and
$^{3}D_1$ states are coupled. The only two free parameters are tuned so as to
reproduce mass and width of the $\phi(1020)$, but come out reasonably close to
previously used values. Among the model's $T$-matrix poles, there are good
candidates for observed resonances, as well other ones that should exist
according to the quark model. Besides the expected resonances as unitarized
confinement states, a dynamical resonance pole is found at $(2186-i246)$ MeV.
The huge width makes its interpretation as the $\phi(2170)$ somewhat dubious,
but further improvements of the model may change this conclusion.",0909.0051v3
2009-09-02,Black-hole quasinormal resonances: Wave analysis versus a geometric-optics approximation,"It has long been known that null unstable geodesics are related to the
characteristic modes of black holes-- the so called quasinormal resonances. The
basic idea is to interpret the free oscillations of a black hole in the eikonal
limit in terms of null particles trapped at the unstable circular orbit and
slowly leaking out. The real part of the complex quasinormal resonances is
related to the angular velocity at the unstable null geodesic. The imaginary
part of the resonances is related to the instability timescale (or the inverse
Lyapunov exponent) of the orbit. While this geometric-optics description of the
black-hole quasinormal resonances in terms of perturbed null {\it rays} is very
appealing and intuitive, it is still highly important to verify the validity of
this approach by directly analyzing the Teukolsky wave equation which governs
the dynamics of perturbation {\it waves} in the black-hole spacetime. This is
the main goal of the present paper. We first use the geometric-optics technique
of perturbing a bundle of unstable null rays to calculate the resonances of
near-extremal Kerr black holes in the eikonal approximation. We then directly
solve the Teukolsky wave equation (supplemented by the appropriate physical
boundary conditions) and show that the resultant quasinormal spectrum obtained
directly from the wave analysis is in accord with the spectrum obtained from
the geometric-optics approximation of perturbed null rays.",0909.0314v1
2009-11-24,Film-thickness dependence of 10 GHz Nb coplanar-waveguide resonators,"We have studied Nb lambda/2 coplanar-waveguide (CPW) resonators whose
resonant frequencies are 10-11 GHz. The resonators have different film
thicknesses, t=0.05, 0.1, 0.2, and 0.3 um. We measured at low temperatures,
T=0.02-5 K, one of the scattering-matrix element, S_21, which is the
transmission coefficient from one port to the other. At the base temperatures,
T=0.02-0.03 K, the resonators are overcoupled to the input/output microwave
lines, and the loaded quality factors are on the order of 10^3. The resonant
frequency has a considerably larger film-thickness dependence compared to the
predictions by circuit simulators which calculate the inductance of CPW taking
into account L_g only, where L_g is the usual magnetic inductance determined by
the CPW geometry. By fitting a theoretical S_21 vs. frequency curve to the
experimental data, we determined for each film thickness, the phase velocity of
the CPW with an accuracy better than 0.1%. The large film-thickness dependence
must be due to the kinetic inductance L_k of the CPW center conductor. We also
measured S_21 as a function of temperature up to T=4-5 K, and confirmed that
both thickness and temperature dependence are consistent with the theoretical
prediction for L_k.",0911.4536v1
2010-06-04,Turbulence effects on supernova neutrinos,"Multi-dimensional core-collapse supernova simulations exhibit turbulence of
large amplitude and over large scales. As neutrinos pass through the supernova
mantle the turbulence is expected to modify their evolution compared to the
case where the explosion is free of turbulence. In this paper we study this
turbulence effect upon the neutrinos modelling the turbulence expected from
multi-dimensional simulations by adding matter density fluctuations to density
profiles taken from one-dimensional hydrodynamical simulations. We investigate
the impact upon the supernova neutrino transition probabilities as a function
of the neutrino mixing angle theta_13 and turbulence amplitude. In the high (H)
resonant channel and with large theta_13 values we find that turbulence is
effectively two flavor for fluctuation amplitudes <~ 1% and have identified a
new effect due to the combination of turbulence and multiple H resonances that
leads to a sensitivity to fluctuations amplitudes as small as ~ 0.001%. At
small values of theta_13, beyond the range achievable in Earth based
experiments, we find that turbulence leads to new flavor transient effects in
the channel where the MSW H resonance occurs. Finally, we investigate large
amplitude fluctuations which lead to three flavor effects due to broken HL
factorization and significant non-resonant transitions and identify two
non-resonant turbulence effects, one depending on the theta_13, and the other
independent of this angle and due to the low (L) MSW resonance.",1006.0913v2
2010-06-28,"New experimental study of low-energy (p,gamma) resonances in magnesium isotopes","Proton captures on Mg isotopes play an important role in the Mg-Al cycle
active in stellar H shell burning. In particular, the strengths of low-energy
resonances with E < 200 keV in 25Mg(p,gamma)26Al determine the production of
26Al and a precise knowledge of these nuclear data is highly desirable.
Absolute measurements at such low-energies are often very difficult and
hampered by gamma-ray background as well as changing target stoichiometry
during the measurements. The latter problem can be partly avoided using higher
energy resonances of the same reaction as a normalization reference. Hence the
parameters of suitable resonances have to be studied with adequate precision.
In the present work we report on new measurements of the resonance strengths
omega_gamma of the E = 214, 304, and 326 keV resonances in the reactions
24Mg(p,gamma)25Al, 25Mg(p,gamma)26Al, and 26Mg(p,gamma)27Al, respectively.
These studies were performed at the LUNA facility in the Gran Sasso underground
laboratory using multiple experimental techniques and provided results with a
higher accuracy than previously achieved.",1006.5281v1
2010-08-24,Spontaneous decay of an emitter's excited state near a finite-length metallic carbon nanotube,"The spontaneous decay of an excited state of an emitter placed in the
vicinity of a metallic single-wall carbon nanotube (SWNT) was examined
theoretically. The emitter-SWNT coupling strongly depends on the position of
the emitter relative to the SWNT, the length of the SWNT, the dipole transition
frequency and the orientation of the emitter. In the high-frequency regime,
dips in the spectrum of the spontaneous decay rate exist at the resonance
frequencies in the spectrum of the SWNT conductivity. In the
intermediate-frequency regime, the SWNT conductivity is very low, and the
spontaneous decay rate is practically unaffected by the SWNT. In the
low-frequency regime, the spectrum of the spontaneous decay rate contains
resonances at the antennas resonance frequencies for surface-wave propagation
in the SWNT. Enhancement of both the total and radiative spontaneous decay
rates by several orders in magnitude is predicted at these resonance
frequencies. The strong emitter-field coupling is achieved, in spite of the low
Q factor of the antenna resonances, due to the very high magnitude of the
electromagnetic field in the near-field zone. The vacuum Rabi oscillations of
the population of the excited emitter state are exhibited when the emitter is
coupled to an antenna resonance of the SWNT.",1008.4015v1
2010-09-28,Few-body resonances of unequal-mass systems with infinite interspecies two-body s-wave scattering length,"Two-component Fermi and Bose gases with infinitely large interspecies s-wave
scattering length $a_s$ exhibit a variety of intriguing properties. Among these
are the scale invariance of two-component Fermi gases with equal masses, and
the favorable scaling of Efimov features for two-component Bose gases and
Bose-Fermi mixtures with unequal masses. This paper builds on our earlier work
[D. Blume and K. M. Daily, arXiv:1006.5002] and presents a detailed discussion
of our studies of small unequal-mass two-component systems with infinite $a_s$
in the regime where three-body Efimov physics is absent. We report on
non-universal few-body resonances. Just like with two-body systems on
resonance, few-body systems have a zero-energy bound state in free space and a
diverging generalized scattering length. Our calculations are performed within
a non-perturbative microscopic framework and investigate the energetics and
structural properties of small unequal-mass two-component systems as functions
of the mass ratio $\kappa$, and the numbers $N_{1}$ and $N_2$ of heavy and
light atoms. For purely attractive Gaussian two-body interactions, we find that
the $(N_1,N_2)=(2,1)$ and $(3,1)$ systems exhibit three-body and four-body
resonances at mass ratios $\kappa = 12.314(2)$ and 10.4(2), respectively. The
three- and four-particle systems on resonance are found to be large. This
suggests that the corresponding wave function has relatively small overlap with
deeply-bound dimers, trimers or larger clusters and that the three- and
four-body systems on resonance have a comparatively long lifetime. Thus, it
seems feasible that the features discussed in this paper can be probed
experimentally with present-day technology.",1009.5703v1
2010-10-11,Wave functions for dynamically generated resonances; the two $Λ(1405)$ and $Λ(1670)$,"In this work we develop a formalism to evaluate wave functions in momentum
and coordinate space for the resonant states dynamically generated in a unitary
coupled channel approach. The on shell approach for the scattering matrix,
commonly used, is also obtained in Quantum Mechanics with a separable
potential, which allows one to write wave functions in a trivial way. We
develop useful relationships among the couplings of the dynamically generated
resonances to the different channels and the wave functions at the origin. The
formalism provides an intuitive picture of the resonances in the coupled
channel approach, as bound states of one bound channel, which decays into open
ones. It also provides an insight and practical rules for evaluating couplings
of the resonances to external sources and how to deal with final state
interaction in production processes. As an application of the formalism we
evaluate the wave functions of the two $\Lambda(1405)$ states in the $\pi
\Sigma$, $\bar{K} N$ and other coupled channels. It also offers a practical way
to study three body systems when two of them cluster into a resonance.",1010.2147v1
2010-10-18,The nature of transmission resonances in plasmonic metallic gratings,"Using the Fourier modal method (FMM) we report our analysis of the
transmission resonances of a plasmonic grating with sub-wavelength period and
extremely narrow slits for wavelengths of the incoming, transverse magnetic
(TM)-polarized, radiation ranging from 240nm to 1500nm and incident angles from
0 degree to 90 degree. In particular, we study the case of a silver grating
placed in vacuo. Consistent with previous studies on the topic, we highlight
that the main mechanism for extraordinary transmission is a TM-Fabry-Perot (FP)
branch supported by waveguide modes inside each slit. The TM-FP branch may also
interact with surface plasmons (SPs) at the air/Ag interface through the
reciprocal lattice vectors of the grating, for periods comparable with the
incoming wavelength. When the TM-FP branch crosses a SP branch, a band gap is
formed along the line of the SP dispersion. The gap has a Fano-Feshbach
resonance at the low frequency band edge and a ridge resonance with extremely
long lifetime at the high frequency band edge. We discuss the nature of these
dispersion features, and in particular we describe the ridge resonance in the
framework of guided-mode resonances (GMRs). In addition, we elucidate the
connection of the coupling between the TM-FP branch and SPs within the Rayleigh
condition. We also study the peculiar characteristics of the field localization
and the energy transport in two topical examples.",1010.3670v1
2010-11-02,Strong Interactions of Single Atoms and Photons near a Dielectric Boundary,"Modern research in optical physics has achieved quantum control of strong
interactions between a single atom and one photon within the setting of cavity
quantum electrodynamics (cQED). However, to move beyond current
proof-of-principle experiments involving one or two conventional optical
cavities to more complex scalable systems that employ N >> 1 microscopic
resonators requires the localization of individual atoms on distance scales <
100 nm from a resonator's surface. In this regime an atom can be strongly
coupled to a single intracavity photon while at the same time experiencing
significant radiative interactions with the dielectric boundaries of the
resonator. Here, we report an initial step into this new regime of cQED by way
of real-time detection and high-bandwidth feedback to select and monitor single
Cesium atoms localized ~100 nm from the surface of a micro-toroidal optical
resonator. We employ strong radiative interactions of atom and cavity field to
probe atomic motion through the evanescent field of the resonator. Direct
temporal and spectral measurements reveal both the significant role of
Casimir-Polder attraction and the manifestly quantum nature of the atom-cavity
dynamics. Our work sets the stage for trapping atoms near micro- and
nano-scopic optical resonators for applications in quantum information science,
including the creation of scalable quantum networks composed of many
atom-cavity systems that coherently interact via coherent exchanges of single
photons.",1011.0740v1
2010-12-16,Theory of Secular Chaos and Mercury's Orbit,"We study the chaotic orbital evolution of planetary systems, focusing on
secular (i.e., orbit-averaged) interactions, because these often dominate on
long timescales. We first focus on the evolution of a test particle that is
forced by multiple massive planets. To linear order in eccentricity and
inclination, its orbit precesses with constant frequencies. But nonlinearities
can shift the frequencies into and out of secular resonance with the planets'
eigenfrequencies, or with linear combinations of those frequencies. The overlap
of these nonlinear secular resonances drive secular chaos in planetary systems.
We quantify the resulting dynamics for the first time by calculating the
locations and widths of nonlinear secular resonances. When results from both
analytical calculations and numerical integrations are displayed together in a
newly developed ""map of the mean momenta"" (MMM), the agreement is excellent.
This map is particularly revealing for non-coplanar planetary systems and
demonstrates graphically that chaos emerges from overlapping secular
resonances. We then apply this newfound understanding to Mercury. Previous
numerical simulations have established that Mercury's orbit is chaotic, and
that Mercury might even collide with Venus or the Sun. We show that Mercury's
chaos is primarily caused by the overlap between resonances that are
combinations of four modes, the Jupiter-dominated eccentricity mode, the
Venus-dominated inclination mode and Mercury's free eccentricity and
inclination. Numerical integration of the Solar system confirms that a slew of
these resonant angles alternately librate and circulate. We are able to
calculate the threshold for Mercury to become chaotic: Jupiter and Venus must
have eccentricity and inclination of a few percent. Mercury appears to be
perched on the threshold for chaos.",1012.3706v1
2011-01-16,Direct observation of room temperature high-energy resonant excitonic effects in graphene,"Using a combination of ultraviolet-vacuum ultraviolet reflectivity and
spectroscopic ellipsometry, we observe a resonant exciton at an unusually high
energy of 6.3eV in epitaxial graphene. Surprisingly, the resonant exciton
occurs at room temperature and for a very large number of graphene layers
$N$$\approx$75, thus suggesting a poor screening in graphene. The optical
conductivity ($\sigma_1$) of resonant exciton scales linearly with number of
graphene layer (up to \emph{at least} 8 layers) implying quantum character of
electrons in graphene. Furthermore, a prominent excitation at 5.4eV, which is a
mixture of interband transitions from $\pi$ to $\pi^{*}$ at the M point and a
$\pi$ plasmonic excitation, is observed. In contrast, for graphite the resonant
exciton is not observable but strong interband transitions are seen instead.
Supported by theoretical calculations, for $N \leq$ 28 the $\sigma_1$ is
dominated by the resonant exciton, while for $N >$ 28 it is a mixture between
exitonic and interband transitions. The latter is characteristic for graphite,
indicating a crossover in the electronic structure. Our study shows that
important elementary excitations in graphene occur at high binding energies and
elucidate the differences in the way electrons interact in graphene and
graphite.",1101.3060v1
2011-02-02,Matryoshka Locally Resonant Sonic Crystal,"The results of numerical modelling of sonic crystals with resonant array
elements are reported. The investigated resonant elements include plain slotted
cylinders as well as various their combinations, in particular, Russian doll or
Matryoshka configurations. The acoustic band structure and transmission
characteristics of such systems have been computed with the use of finite
element methods. The general concept of a locally resonant sonic crystal is
proposed, which utilises acoustic resonances to form additional band gaps that
are decoupled from Bragg gaps. An existence of a separate attenuation mechanism
associated with the resonant elements, which increases performance in the lower
frequency regime has been identified. The results show a formation of broad
band gaps positioned significantly below the first Bragg frequency. For low
frequency broadband attenuation a most optimal configuration is the Matryoshka
sonic crystal, where each scattering unit is composed of multiple concentric
slotted cylinders. This system forms numerous gaps in the lower frequency
regime, below Bragg bands, whilst maintaining a reduced crystal size viable for
noise barrier technology. The finding opens new perspectives for construction
of sound barriers in the low frequency range usually inaccessible by
traditional means including conventional sonic crystals.",1102.0399v1
2011-02-07,Pathway interference in a loop array of three coupled microresonators,"A system of three coupled toroidal microresonators arranged in a loop
configuration is studied. This setup allows light entering the resonator setup
from a tapered fiber to evolve along a variety of different pathways before
leaving again through the fiber. In particular, the loop configuration of the
resonators allows for an evolution which we term roundtrip process, in which
the light evolves from one resonator sequentially through all others back to
the initial one. This process renders the optical properties of the system
sensitive to the phases of all coupling and scattering constants in the system.
We analyze the transmission and reflection spectra, and interpret them in terms
of interference between the various possible evolution pathways through the
resonator system. In particular, we focus on the phase dependence of the
optical properties. Finally, we discuss possible applications for this phase
sensitivity induced by the roundtrip process, such as the measurement of the
position of a nanoparticle close to one of the resonators, and the measurement
of changes in the refractive index between two resonators. Our analytical
results for the applications are supported by proof-of-principle calculations
based on finite-difference-time-domain solution ofMaxwell's equations in two
dimensions on a grid.",1102.1372v1
2011-02-10,Transformation of Trojans into Quasi-Satellites During Planetary Migration and Their Subsequent Close-Encounters with the Host Planet,"We use numerical integrations to investigate the dynamical evolution of
resonant Trojan and quasi-satellite companions during the late stages of
migration of the giant planets Jupiter, Saturn, Uranus, and Neptune. Our
migration simulations begin with Jupiter and Saturn on orbits already well
separated from their mutual 2:1 mean-motion resonance. Neptune and Uranus are
decoupled from each other and have orbital eccentricities damped to near their
current values. From this point we adopt a planet migration model in which the
migration speed decreases exponentially with a characteristic timescale tau
(the e-folding time). We perform a series of numerical simulations, each
involving the migrating giant planets plus test particle Trojans and
quasi-satellites. We find that the libration frequencies of Trojans are similar
to those of quasi-satellites. This similarity enables a dynamical exchange of
objects back and forth between the Trojan and quasi-satellite resonances during
planetary migration. Furthermore, under the influence of these secondary
resonances quasi-satellites can have their libration amplitudes enlarged until
they undergo a close-encounter with their host planet and escape from the
resonance. High-resolution simulations of this escape process reveal that ~80%
of Jovian quasi-satellites experience one or more close-encounters within
Jupiter's Hill radius (R_H) as they are forced out of the quasi-satellite
resonance. As many as ~20% come within R_H/4 and ~2.5% come within R_H/10.
Close-encounters of escaping quasi-satellites occur near or even below the
2-body escape velocity from the host planet.",1102.2211v1
2011-03-18,A periodic table for the excited Nucleon and Delta spectrum in a relativistic chiral quark model,"A possibility of the construction of a periodic table for the excited baryon
spectrum is shown in the frame of a relativistic chiral quark model based on
selection rules derived from the one-pion exchange mechanism. It is shown that
all the $N^*$ and $\Delta^*$ resonances appearing in the $\pi N$ scattering
data and strongly coupling to the $\pi N$ channel are identified with the
orbital configurations $(1S_{1/2})^2(nlj)$. Baryon resonances corresponding to
the orbital configuration with two valence quarks in excited states couple
strongly to the $\pi \pi N$-channel, but not to the $\pi N$ channel.
  At low energy scale up to 2000 MeV, the obtained numerical estimations for
the SU(2) baryon states (up to and including F-wave $N^*$ and $\Delta^*$
resonances) within the schematic periodic table are mostly consistent with the
experimental data.
  It is argued that due-to the overestimation of the ground state N(939) and
Roper resonance N(1440) almost by the same amount and that the Roper resonance
is a radial excitation of the N(939), the ""lowering mechanism"" for the both
baryon states must be the same. The same mechanism is expected in the $\Delta$
sector. At higher energies, where the experimental data are poor, we can extend
our model schematically and predict seven new $N^*$ and four $\Delta^*$
resonances with larger spin values.",1103.3661v4
2011-04-22,The nature of the Lambda(1405) resonance in chiral dynamics,"The Lambda(1405) baryon resonance plays an outstanding role in various
aspects in hadron and nuclear physics. It has been considered that the
Lambda(1405) resonance is generated by the attractive interaction of the
antikaon and the nucleon, as a quasi-bound state below the threshold decaying
into the pi Sigma channel. Thus, the structure of Lambda(1405) is closely
related to the Kbar N interaction which is the fundamental ingredient to study
few-body systems with antikaon. In this paper, after reviewing the basic
properties of the Lambda(1405) resonance, we introduce the dynamical
coupled-channel model which respects chiral symmetry of QCD and the unitarity
of the scattering amplitude. We show that the structure of the Lambda(1405)
resonance is dominated by the meson-baryon molecule component and is described
as a superposition of two independent states. The meson-baryon nature of
Lambda(1405) leads to various hadronic molecule states in few-body systems with
strangeness which are hadron composite systems driven by the hadronic
interactions. We summarize the recent progress in the investigation of the
Lambda(1405) structure and future perspective of the physics of the
Lambda(1405) resonance.",1104.4474v3
2011-04-26,Inclination Mixing in the Classical Kuiper Belt,"We investigate the long-term evolution of the inclinations of the known
classical and resonant Kuiper belt objects (KBOs). This is partially motivated
by the observed bimodal inclination distribution and by the putative physical
differences between the low- and high-inclination populations. We find that
some classical KBOs undergo large changes in inclination over gigayear
timescales, which means that a current member of the low-inclination population
may have been in the high-inclination population in the past, and vice versa.
The dynamical mechanisms responsible for the time-variability of inclinations
are predominantly distant encounters with Neptune and chaotic diffusion near
the boundaries of mean motion resonances. We reassess the correlations between
inclination and physical properties including inclination time-variability. We
find that the size-inclination and color-inclination correlations are less
statistically significant than previously reported (mostly due to the increased
size of the data set since previous works with some contribution from
inclination variability). The time-variability of inclinations does not change
the previous finding that binary classical KBOs have lower inclinations than
non-binary objects. Our study of resonant objects in the classical Kuiper belt
region includes objects in the 3:2, 7:4, 2:1, and eight higher-order mean
motion resonances. We find that these objects (some of which were previously
classified as non-resonant) undergo larger changes in inclination compared to
the non-resonant population, indicating that their current inclinations are not
generally representative of their original inclinations. They are also less
stable on gigayear timescales.",1104.4967v2
2011-05-04,Controlling a diatomic shape resonance with non-resonant light,"A (diatomic) shape resonance is a metastable state of a pair of colliding
atoms quasi-bound by the centrifugal barrier imposed by the angular momentum
involved in the collision. The temporary trapping of the atoms' scattering
wavefunction corresponds to an enhanced atom pair density at low interatomic
separations. This leads to larger overlap of the wavefunctions involved in a
molecule formation process such as photoassociation, rendering the process more
efficient. However, for an ensemble of atoms, the atom pair density will only
be enhanced if the energy of the resonance comes close to the temperature of
the atomic ensemble. Herein we explore the possibility of controlling the
energy of a shape resonance by shifting it toward the temperature of atoms
confined in a trap. The shifts are imparted by the interaction of non-resonant
light with the anisotropic polarizability of the atom pair, which affects both
the centrifugal barrier and the pair's rotational and vibrational levels. We
find that at laser intensities of up to $5\times 10^{9}$ W/cm$^2$ the pair
density is increased by one order of magnitude for $^{87}$Rb atoms at $100
\mu$K and by two orders of magnitude for $^{88}$Sr atoms at $20 \mu$K.",1105.0761v1
2011-06-01,Three Body Resonance Overlap in Closely Spaced Multiple Planet Systems,"We compute the strengths of zero-th order (in eccentricity) three-body
resonances for a co-planar and low eccentricity multiple planet system. In a
numerical integration we illustrate that slowly moving Laplace angles are
matched by variations in semi-major axes among three bodies with the outer two
bodies moving in the same direction and the inner one moving in the opposite
direction, as would be expected from the two quantities that are conserved in
the three-body resonance. A resonance overlap criterion is derived for the
closely and equally spaced, equal mass system with three-body resonances
overlapping when interplanetary separation is less than an order unity factor
times the planet mass to the one quarter power. We find that three-body
resonances are sufficiently dense to account for wander in semi-major axis seen
in numerical integrations of closely spaced systems and they are likely the
cause of instability of these systems. For interplanetary separations outside
the overlap region, stability timescales significantly increase. Crudely
estimated diffusion coefficients in eccentricity and semi-major axis depend on
a high power of planet mass and interplanetary spacing. An exponential
dependence previously fit to stability or crossing timescales is likely due to
the limited range of parameters and times possible in integration and the
strong power law dependence of the diffusion rates on these quantities.",1106.0156v2