publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2017-06-07 | Adiabatic and nonadiabatic spin torques induced by spin-triplet supercurrent | We study spin transfer torques induced by a spin-triplet supercurrent in a
magnet with the superconducting proximity effect. By a perturbative approach,
we show that spin-triplet correlations realize new types of torques, which are
analogous to the adiabatic and non-adiabatic ($\beta$) torques, without
extrinsic spin-f... | 1706.02296v2 |
2017-06-26 | Perpendicular magnetic anisotropy in insulating ferrimagnetic gadolinium iron garnet thin films | We present experimental control of the magnetic anisotropy in a gadolinium
iron garnet (GdIG) thin film from in-plane to perpendicular anisotropy by
simply changing the sample temperature. The magnetic hysteresis loops obtained
by SQUID magnetometry measurements unambiguously reveal a change of the
magnetically easy ax... | 1706.08488v1 |
2017-09-07 | Tunable spin pumping in exchange coupled magnetic trilayers | Magnetic thin films at ferromagnetic resonance (FMR) leak angular momentum,
which may be absorbed by adjacent layers. This phenomenon, known as spin
pumping, is manifested by an increase in the resonance linewidth ($\Delta H$),
and the closely related Gilbert damping. Another effect of this transfer of
spin currents is... | 1709.02295v1 |
2017-10-30 | Probe of Spin Dynamics in Superconducting NbN Thin Films via Spin Pumping | The emerging field of superconductor (SC) spintronics has attracted intensive
attentions recently. Many fantastic spin dependent properties in SC have been
discovered, including the observation of large magnetoresistance, long spin
lifetimes and the giant spin Hall effect in SC, as well as spin supercurrent in
Josephso... | 1710.10833v2 |
2017-11-17 | Shot noise of charge and spin transport in a junction with a precessing molecular spin | Magnetic molecules and nanomagnets can be used to influence the electronic
transport in mesoscopic junction. In a magnetic field the precessional motion
leads to resonances in the dc- and ac-transport properties of a nanocontact, in
which the electrons are coupled to the precession. Quantities like the
dc-conductance o... | 1711.06759v2 |
2018-02-05 | Cooper-Pair Spin Current in a Strontium Ruthenate Heterostructure | It has been recognized that the condensation of spin-triplet Cooper pairs
requires not only the broken gauge symmetry but also the spin ordering as well.
One consequence of this is the possibility of the Cooper-pair spin current
analogous to the magnon spin current in magnetic insulators, the analogy also
extending to ... | 1802.01599v1 |
2018-02-12 | Spin-orbit torque and spin pumping in YIG/Pt with interfacial insertion layers | We experimentally investigate spin-orbit torque and spin pumping in
Y$_3$Fe$_5$O$_{12}$(YIG)/Pt bilayers with ultrathin insertion layers at the
interface. An insertion layer of Cu suppresses both spin-orbit torque and spin
pumping, whereas an insertion layer of Ni$_{80}$Fe$_{20}$ (permalloy, Py)
enhances them, in a qua... | 1802.03865v3 |
2018-06-01 | Dirac-Surface-State Modulated Spin Dynamics in a Ferrimagnetic Insulator at Room Temperature | This work demonstrates dramatically modified spin dynamics of magnetic
insulator (MI) by the spin-momentum locked Dirac surface states of the adjacent
topological insulator (TI) which can be harnessed for spintronic applications.
As the Bi-concentration x is systematically tuned in 5 nm thick (BixSb1-x)2Te3
TI film, th... | 1806.00151v1 |
2018-08-23 | Reduced thermal stability of antiferromagnetic nanostructures | Antiferromagnetic materials hold promising prospects in novel types of
spintronics applications. Assessing the stability of antiferromagnetic
nanostructures against thermal excitations is a crucial aspect of designing
devices with a high information density. Here we use theoretical calculations
and numerical simulation... | 1808.07665v3 |
2018-09-17 | On the speed of domain walls in thin nanotubes: the transition from the linear to the magnonic regime | Numerical simulations of domain wall propagation in thin nanotubes when an
external magnetic field is applied along the nanotube axis have shown an
unexpected behavior described as a transition from a linear to a magnonic
regime. As the applied magnetic field increases, the initial regime of linear
growth of the speed ... | 1809.06278v3 |
2018-10-19 | Magnon properties of random alloys | We study magnon properties in terms of spin stiffness, Curie temperatures and
magnon spectrum of Fe-Ni, Co-Ni and Fe-Co random alloys using a combination of
electronic structure calculations and atomistic spin dynamics simulations.
Influence of the disorder are studied in detail by use of large supercells with
random a... | 1810.08487v1 |
2018-11-09 | Switching of biaxial synthetic antiferromagnets: a micromagentic study | We simulate the switching behavior of nanoscale synthetic antiferromagnets
(SAFs), inspired by recent experimental progress in spin-orbit-torque switching
of crystal antiferromagnets. The SAF consists of two ferromagnetic thin films
with in-plane biaxial anisotropy and interlayer exchange coupling. Staggered
field-like... | 1811.04094v2 |
2018-12-03 | Microscopic theory of magnon-drag electron flow in ferromagnetic metals | A temperature gradient applied to a ferromagnetic metal induces not only
independent flows of electrons and magnons but also drag currents because of
their mutual interaction. In this paper, we present a microscopic study of the
electron flow induced by the drag due to magnons. The analysis is based on the
$s$-$d$ mode... | 1812.00720v1 |
2019-01-17 | Spin transport parameters of NbN thin films characterised by spin pumping experiments | We present measurements of ferromagnetic-resonance - driven spin pumping and
inverse spin-Hall effect in NbN/Y3Fe5O12 (YIG) bilayers. A clear enhancement of
the (effective) Gilbert damping constant of the thin-film YIG was observed due
to the presence of the NbN spin sink. By varying the NbN thickness and
employing spi... | 1901.05753v1 |
2019-02-12 | Characterization of spin wave propagation in (111) YIG thin films with large anisotropy | We report on long-range spin wave (SW) propagation in nanometer-thick yttrium
iron garnet (YIG) film with an ultralow Gilbert damping. The knowledge of a
wavenumber value $|\vec{k}|$ is essential for designing SW devices. Although
determining the wavenumber $|\vec{k}|$ in experiments like Brillouin light
scattering spe... | 1902.04608v1 |
2019-03-20 | Nonlinear magnetization dynamics driven by strong terahertz fields | We present a comprehensive experimental and numerical study of magnetization
dynamics triggered in a thin metallic film by single-cycle terahertz pulses of
$\sim20$ MV/m electric field amplitude and $\sim1$ ps duration. The
experimental dynamics is probed using the femtosecond magneto-optical Kerr
effect (MOKE), and it... | 1903.08395v2 |
2019-04-11 | Measurement of spin mixing conductance in Ni$_{81}$Fe$_{19}$/$α$-W and Ni$_{81}$Fe$_{19}$/$β$-W heterostrucutures via ferromagnetic resonance | We present measurements of interfacial Gilbert damping due to the spin
pumping effect in Ni$_{81}$Fe$_{19}$/W heterostructures. Measurements were
compared for heterostructures in which the crystallographic phase of W, either
$\alpha$(bcc)-W or $\beta$(A15)-W, was enriched through deposition conditions
and characterized... | 1904.05950v2 |
2019-05-26 | Influence of field-like torque in synchronization of spin torque oscillators | The magnetization dynamics of two parallelly coupled spin torque oscillators,
destabilization of steady states and removal of multistability, are
investigated by taking into account the influence of field-like torque. It is
shown that the existence of such torque can cancel the effect of damping and
can, therefore, cau... | 1905.10804v2 |
2019-05-30 | Sub-nanosecond switching in a cryogenic spin-torque spin-valve memory element with a dilute permalloy free layer | We present a study of the pulsed current switching characteristics of
spin-valve nanopillars with in-plane magnetized dilute permalloy and undiluted
permalloy free layers in the ballistic regime at low temperature. The dilute
permalloy free layer device switches much faster: the characteristic switching
time for a perm... | 1905.13262v1 |
2019-07-05 | Theory for shift current of bosons: Photogalvanic spin current in ferrimagnetic and antiferromagnetic insulators | We theoretically study the optical generation of dc spin current (i.e., a
spin-current solar cell) in ordered antiferromagnetic and ferrimagnetic
insulators, motivated by a recent study on the laser-driven spinon spin current
in noncentrosymmetric quantum spin chains [H. Ishizuka and M. Sato, Phys. Rev.
Lett. 122, 1977... | 1907.02734v1 |
2019-07-10 | Temperature dependence of magnetic resonance in ferrimagnetic GdFeCo alloys | We provide a macroscopic theory and experimental results for magnetic
resonances of antiferromagnetically-coupled ferrimagnets. Our theory, which
interpolates the dynamics of antiferromagnets and ferromagnets smoothly, can
describe ferrimagnetic resonances across the angular momentum compensation
point. We also present... | 1907.04540v1 |
2019-07-11 | Improving the Signal-to-noise Ratio for Heat-Assisted Magnetic Recording by Optimizing a High/Low Tc bilayer structure | We optimize the recording medium for heat-assisted magnetic recording by
using a high/low $T_{\mathrm{c}}$ bilayer structure to reduce AC and DC noise.
Compared to a former work, small Gilbert damping $\alpha=0.02$ is considered
for the FePt like hard magnetic material. Atomistic simulations are performed
for a cylindr... | 1907.05027v1 |
2019-07-19 | A cryogenic memory element based on an anomalous Josephson junction | We propose a non-volatile memory element based on a lateral ferromagnetic
Josephson junction with spin-orbit coupling and out-of-plane magnetization. The
interplay between the latter and the intrinsic exchange field of the
ferromagnet leads to a magnetoelectric effect that couples the charge current
through the junctio... | 1907.08454v2 |
2019-07-23 | Electron transport in high-entropy alloys: Al$_{x}$CrFeCoNi as a case study | The high-entropy alloys Al$_{x}$CrFeCoNi exist over a broad range of Al
concentrations ($0 < x < 2$). With increasing Al content their structure is
changed from the fcc to bcc phase. We investigate the effect of such structural
changes on transport properties including the residual resistivity and the
anomalous Hall re... | 1907.09731v1 |
2019-09-11 | Chaos in nanomagnet via feedback current | Nonlinear magnetization dynamics excited by spin-transfer effect with
feedback current is studied both numerically and analytically. The numerical
simulation of the Landau-Lifshitz-Gilbert equation indicates the positive
Lyapunov exponent for a certain range of the feedback rate, which identifies
the existence of chaos... | 1909.05315v2 |
2019-11-27 | Ellipticity and Dissipation Effects in Magnon Spin Valves | We consider alignment-dependent spin and heat transport across a magnon spin
valve in the tunneling regime, i.e., a junction consisting of two weakly
coupled ferromagnetic insulators. We determine the difference in spin and heat
conductance between the parallel and antiparallel configuration of the
magnetization direct... | 1911.12017v2 |
2020-03-24 | Spin-transfer torque driven intrinsic localized spin excitations in the presence of field-like torque | We study the existence of intrinsic localized one-spin excitation in the
Heisenberg one-dimensional ferromagnetic spin chain in the presence of
perpendicular and parallel external magnetic fields and current with
spin-transfer torque and field-like torque. The
Landau-Lifshitz-Gilbert-Slonczewski(LLGS) equation is exact... | 2003.11023v2 |
2020-04-02 | Stable solitons in a nearly PT-symmetric ferromagnet with spin-transfer torque | We consider the Landau-Lifshitz equation for the spin torque oscillator - a
uniaxial ferromagnet in an external magnetic field with polarised spin current
driven through it. In the absence of the Gilbert damping, the equation turns
out to be PT-symmetric. We interpret the PT-symmetry as a balance between gain
and loss ... | 2004.01245v2 |
2020-05-11 | Manipulating 1-dimensinal skyrmion motion by external magnetic field gradient | We have investigated an analytic formula of the 1-dimensional magnetic
skyrmion dynamics under external magnetic field gradient. We find excellent
agreement between the analytical model and micromagnetic simulation results for
various magnetic parameters such as the magnetic field gradient, Gilbert
damping constant. We... | 2005.05011v1 |
2020-07-08 | Finite-frequency spin susceptibility and spin pumping in superconductors with spin-orbit relaxation | Static spin susceptibility of superconductors with spin-orbit relaxation has
been calculated in the seminal work of A.A. Abrikosov and L.P. Gor'kov [Sov.
Phys. JETP, {\bf 15}, 752 (1962)]. Surprisingly the generalization of this
result to finite frequencies has not been done despite being quite important
for the modern... | 2007.04372v2 |
2020-07-16 | Thermal noise effects on the magnetization switching of a ferromagnetic anomalous Josephson junction | We discuss the effects of thermal noise on the magnetic response of a lateral
ferromagnetic Josephson junction with spin-orbit coupling and out-of-plane
magnetization. The direction of the magnetic moment in the ferromagnetic layer
can be inverted by using controlled current pulses. This phenomenon is due to
the magnet... | 2007.08414v3 |
2020-08-21 | Integration and characterization of micron-sized YIG structures with very low Gilbert damping on arbitrary substrates | We present a novel process that allows the transfer of monocrystalline
yttrium-iron-garnet microstructures onto virtually any kind of substrate. The
process is based on a recently developed method that allows the fabrication of
freestanding monocrystalline YIG bridges on gadolinium-gallium-garnet. Here the
bridges' spa... | 2008.09390v1 |
2020-09-01 | Quantum Brownian Motion for Magnets | Spin precession in magnetic materials is commonly modelled with the classical
phenomenological Landau-Lifshitz-Gilbert (LLG) equation. Based on a quantized
spin+environment Hamiltonian, we here derive a general spin operator equation
of motion that describes three-dimensional precession and damping and
consistently acc... | 2009.00600v2 |
2020-09-30 | Quantum hydrodynamics of spin winding | An easy-plane spin winding in a quantum spin chain can be treated as a
transport quantity, which propagates along the chain but has a finite lifetime
due to phase slips. In a hydrodynamic formulation for the winding dynamics, the
quantum continuity equation acquires a source term due to the transverse
vorticity flow. T... | 2010.00144v1 |
2020-11-29 | Cross-sublattice Spin Pumping and Magnon Level Attraction in van der Waals Antiferromagnets | We theoretically study spin pumping from a layered van der Waals
antiferromagnet in its canted ground state into an adjacent normal metal. We
find that the resulting dc spin pumping current bears contributions along all
spin directions. Our analysis allows for detecting intra- and cross-sublattice
spin-mixing conductan... | 2011.14314v1 |
2021-01-18 | Topological electric driving of magnetization dynamics in insulators | Established forms of electromagnetic coupling are usually conservative (in
insulators) or dissipative (in metals and semiconductors). Here we point out
the possibility of nondissipative electric driving of magnetization dynamics,
if the valence electronic states have nontrivial topology in the combined space
of crystal... | 2101.07164v3 |
2021-02-07 | Spinterface Induced Modification in Magnetic Properties in Co40Fe40B20/Fullerene Bilayers | Organic semiconductor/ferromagnetic bilayer thin films can exhibit novel
properties due to the formation of the spinterface at the interface.
Buckminsterfullerene (C60) has been shown to exhibit ferromagnetism at the
interface when it is placed next to a ferromagnet (FM) such as Fe or Co.
Formation of spinterface occur... | 2102.03914v4 |
2021-02-15 | Magnetodynamic properties of dipole-coupled 1D magnonic crystals | Magnonic crystals are magnetic metamaterials, that provide a promising way to
manipulate magnetodynamic properties by controlling the geometry of the
patterned structures. Here, we study the magnetodynamic properties of 1D
magnonic crystals consisting of parallel NiFe strips with different strip
widths and separations.... | 2102.07712v2 |
2021-05-24 | Spin pumping of two-dimensional electron gas with Rashba and Dresselhaus spin-orbit interactions | We theoretically consider spin pumping in a junction between a ferromagnetic
insulator (FI) and a two-dimensional electron gas (2DEG) in which the Rashba
and Dresselhaus spin-orbit interactions coexist. Using second-order
perturbation theory, we derive an increase in linewidth in the case of an
interfacial exchange cou... | 2105.11193v3 |
2021-08-05 | Spin-transfer torque driven localized spin excitations in the presence of field-like torque | We study the existence of localized one-spin excitation in the Heisenberg
one-dimensional ferromagnetic spin chain in the presence of perpendicular and
parallel external magnetic fields and current with spin-transfer torque and
field-like torque. The Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation is
exactly solved... | 2108.02380v1 |
2021-09-07 | Inertial spin dynamics in epitaxial cobalt films | We investigate the spin dynamics driven by terahertz magnetic fields in
epitaxial thin films of cobalt in its three crystalline phases. The terahertz
magnetic field generates a torque on the magnetization which causes it to
precess for about 1 ps, with a sub-picosecond temporal lag from the driving
force. Then, the mag... | 2109.03076v2 |
2021-09-26 | Transition state dynamics of a driven magnetic free layer | Magnetization switching in ferromagnetic structures is an important process
for technical applications such as data storage in spintronics, and therefore
the determination of the corresponding switching rates becomes essential. We
investigate a free-layer system in an oscillating external magnetic field
resulting in an... | 2109.12605v1 |
2021-12-24 | Skyrmion nucleation on the surface of a topological insulator | Skyrmion nucleation induced by spin-transfer torques at an interface of a
topological insulator and a ferromagnetic insulator is investigated. Due to
strong spin-orbit coupling on a surface of topological insulators, which
enhances the effect of spin torques, efficient manipulation of skyrmions is
expected, and therefo... | 2112.12967v2 |
2021-12-10 | Enhanced Planar Antenna Efficiency Through Magnetic Thin-Films | This work proposes to use magnetic material as the substrate of planar
antennas to overcome the platform effect caused by the conducting ground plane.
The upper bound of the radiation efficiency of an electric-current-driven
low-profile antenna is theoretically derived, which is inversely proportional
to the Gilbert da... | 2201.04932v1 |
2022-03-07 | Ultrafast optical observation of spin-pumping induced dynamic exchange coupling in ferromagnetic semiconductor/metal bilayer | Spin angular momentum transfer in magnetic bilayers offers the possibility of
ultrafast and low-loss operation for next-generation spintronic devices. We
report the field- and temperature- dependent measurements on the magnetization
precessions in Co$_2$FeAl/(Ga,Mn)As by time-resolved magneto-optical Kerr
effect (TRMOK... | 2203.03225v2 |
2022-04-21 | Transport theory for topological Josephson junctions with a Majorana qubit | We construct a semiclassical theory for the transport of topological
junctions starting from a microscopic Hamiltonian that comprehensively includes
the interplay among the Majorana qubit, the Josephson phase, and the
dissipation process. With the path integral approach, we derive a set of
semiclassical equations of mo... | 2204.09923v1 |
2022-11-04 | Derivation of Interacting Two-Qubit Dynamics from Spin-Boson Model | We derive damping equations of motion for interacting two-spin states from a
spin-boson model in order to examine qubit dynamics in quantum computers. On
the basis of the composite operator method, we develop the Caldeira-Leggett
approach for open quantum systems so that the entanglement dynamics originated
from the tw... | 2211.02490v1 |
2023-02-06 | Global solutions of the Landau--Lifshitz--Baryakhtar equation | The Landau--Lifshitz--Baryakhtar (LLBar) equation is a generalisation of the
Landau--Lifshitz--Gilbert and the Landau--Lifshitz--Bloch equations which takes
into account contributions from nonlocal damping and is valid at moderate
temperature below the Curie temperature. Therefore, it is used to explain some
discrepanc... | 2302.02556v3 |
2023-03-22 | Twisted bilayer graphene reveals its flat bands under spin pumping | The salient property of the electronic band structure of twisted bilayer
graphene (TBG), at the so-called magic angle (MA), is the emergence of flat
bands around the charge neutrality point. These bands are associated with the
observed superconducting phases and the correlated insulating states. Scanning
tunneling micr... | 2303.12380v2 |
2023-05-01 | Coherent and incoherent magnons induced by strong ultrafast demagnetization in thin permalloy films | Understanding spin dynamics on femto- and picosecond timescales offers new
opportunities for faster and more efficient spintronic devices. Here, we
experimentally investigate the coherent spin dynamics after ultrashort laser
excitation by time-resolved magneto optical Kerr effect (TR-MOKE) in thin
Ni80Fe20 films. We pr... | 2305.00814v2 |
2023-07-15 | Switching current distributions in ferromagnetic anomalous Josephson junctions | We investigate the switching current distributions of ferromagnetic anomalous
Josephson junctions subjected to a linearly increasing bias current. Our study
uncovers a significant correlation between the position of the switching
current distributions and crucial system parameters, such as the strength of
the spin-orbi... | 2307.07751v2 |
2023-07-26 | Oscillatory Edge Modes in Two Dimensional Spin-Torque Oscillator Arrays | Spin torque oscillators (STOs) are dissipative magnetic systems that provide
a natural platform for exploring non-Hermitian phenomena. We theoretically
study a two-dimensional (2d) array of STOs and show that its dynamics can be
mapped to a 2d, non-Hermitian Su-Schrieffer-Heeger (SSH) model. We calculate
the energy spe... | 2307.13876v1 |
2024-03-25 | Detection of spin pumping free of rectification and thermal artefacts in molecular-based ferromagnetic insulator V[TCNE]x~2 | The molecular-based ferrimagnetic insulator V(TCNE)x has gained recent
interest for efficient spin-wave excitation due to its low Gilbert damping
ratio a=4E-5, and narrow ferromagnetic resonance linewidth f=1Oe. Here we
report a clean spin pumping signal detected on V(TCNE)x/metal bilayer
structures, free from spin rec... | 2403.16429v2 |
2024-04-01 | Harnessing Interlayer Magnetic Coupling for Efficient, Field-Free Current-Induced Magnetization Switching in a Magnetic Insulator | Owing to the unique features of low Gilbert damping, long spin-diffusion
lengths and zero Ohmic losses, magnetic insulators are promising candidate
materials for next-generation spintronic applications. However, due to the
localized magnetic moments and the complex metal-oxide interface between
magnetic insulators and ... | 2404.00845v1 |
1999-02-01 | Damping Rates and Mean Free Paths of Soft Fermion Collective Excitations in a Hot Fermion-Gauge-Scalar Theory | We study the transport coefficients, damping rates and mean free paths of
soft fermion collective excitations in a hot fermion-gauge-scalar plasma with
the goal of understanding the main physical mechanisms that determine transport
of chirality in scenarios of non-local electroweak baryogenesis. The focus is
on identif... | 9902218v2 |
2004-11-26 | Open quantum systems | The damping of the harmonic oscillator is studied in the framework of the
Lindblad theory for open quantum systems. A generalization of the fundamental
constraints on quantum mechanical diffusion coefficients which appear in the
master equation for the damped quantum oscillator is presented; the
Schr\"odinger, Heisenbe... | 0411189v1 |
2015-04-16 | Attenuation of short strongly nonlinear stress pulses in dissipative granular chains | Attenuation of short, strongly nonlinear stress pulses in chains of spheres
and cylinders was investigated experimentally and numerically for two ratios of
their masses keeping their contacts identical. The chain with mass ratio 0.98
supports solitary waves and another one (with mass ratio 0.55) supports
nonstationary ... | 1504.04344v1 |
2023-03-15 | Blow-up and decay for a class of variable coefficient wave equation with nonlinear damping and logarithmic source | In this paper, we consider the long time behavior for the solution of a class
of variable coefficient wave equation with nonlinear damping and logarithmic
source. The existence and uniqueness of local weak solution can be obtained by
using the Galerkin method and contraction mapping principle. However, the long
time be... | 2303.08629v1 |
2023-07-12 | Exponential stability of damped Euler-Bernoulli beam controlled by boundary springs and dampers | In this paper, the vibration model of an elastic beam, governed by the damped
Euler-Bernoulli equation
$\rho(x)u_{tt}+\mu(x)u_{t}$$+\left(r(x)u_{xx}\right)_{xx}=0$, subject to the
clamped boundary conditions $u(0,t)=u_x(0,t)=0$ at $x=0$, and the boundary
conditions $\left(-r(x)u_{xx}\right)_{x=\ell}=k_r u_x(\ell,t)+k_a... | 2307.06170v2 |
2017-04-12 | The gradient condition and the contribution of the dynamical part of Green-Kubo formula to the diffusion coefficient | In the diffusive hydrodynamic limit for a symmetric interacting particle
system (such as the exclusion process, the zero range process, the stochastic
Ginzburg-Landau model, the energy exchange model), a possibly non-linear
diffusion equation is derived as the hydrodynamic equation. The bulk diffusion
coefficient of th... | 1704.03745v2 |
2010-06-25 | Perturbations of Mathieu equations with parametric excitation of large period | We consider a linear differential system of Mathieu equations with periodic
coefficients over periodic closed orbits and we prove that, arbitrarily close
to this system, there is a linear differential system of Hamiltonian damped
Mathieu equations with periodic coefficients over periodic closed orbits such
that, all bu... | 1006.5025v1 |
2008-02-07 | Cascade and Damping of Alfvén-Cyclotron Fluctuations: Application to Solar Wind Turbulence Spectrum | With the diffusion approximation, we study the cascade and damping of
Alfv\'{e}n-cyclotron fluctuations in solar plasmas numerically. Motivated by
wave-wave couplings and nonlinear effects, we test several forms of the
diffusion tensor. For a general locally anisotropic and inhomogeneous diffusion
tensor in the wave ve... | 0802.0910v1 |
2023-10-07 | OEDG: Oscillation-eliminating discontinuous Galerkin method for hyperbolic conservation laws | Controlling spurious oscillations is crucial for designing reliable numerical
schemes for hyperbolic conservation laws. This paper proposes a novel, robust,
and efficient oscillation-eliminating discontinuous Galerkin (OEDG) method on
general meshes, motivated by the damping technique in [Lu, Liu, and Shu, SIAM
J. Nume... | 2310.04807v1 |
2018-08-08 | Analysis of quasi-Monte Carlo methods for elliptic eigenvalue problems with stochastic coefficients | We consider the forward problem of uncertainty quantification for the
generalised Dirichlet eigenvalue problem for a coercive second order partial
differential operator with random coefficients, motivated by problems in
structural mechanics, photonic crystals and neutron diffusion. The PDE
coefficients are assumed to b... | 1808.02639v3 |
2021-01-22 | Measurements and analysis of response function of cold atoms in optical molasses | We report our experimental measurements and theoretical analysis of the
position response function of a cloud of cold atoms residing in the viscous
medium of an optical molasses and confined by a magneto-optical trap (MOT). We
measure the position response function by applying a transient homogeneous
magnetic field as ... | 2101.09118v2 |
2020-12-08 | Sparse Correspondence Analysis for Contingency Tables | Since the introduction of the lasso in regression, various sparse methods
have been developed in an unsupervised context like sparse principal component
analysis (s-PCA), sparse canonical correlation analysis (s-CCA) and sparse
singular value decomposition (s-SVD). These sparse methods combine feature
selection and dim... | 2012.04271v1 |
1996-01-09 | Relaxation of Collective Excitations in LJ-13 Cluster | We have performed classical molecular dynamics simulation of $Ar_{13}$
cluster to study the behavior of collective excitations. In the solid ``phase''
of the cluster, the collective oscillation of the monopole mode can be well
fitted to a damped harmonic oscillator. The parameters of the equivalent damped
harmonic osci... | 9601026v2 |
2003-09-11 | Frequency and damping of hydrodynamic modes in a trapped Bose-condensed gas | Recently it was shown that the Landau-Khalatnikov two-fluid hydrodynamics
describes the collision-dominated region of a trapped Bose condensate
interacting with a thermal cloud. We use these equations to discuss the low
frequency hydrodynamic collective modes in a trapped Bose gas at finite
temperatures. We derive a va... | 0309269v1 |
2012-01-31 | Parametric amplification and self-oscillation in a nanotube mechanical resonator | A hallmark of mechanical resonators made from a single nanotube is that the
resonance frequency can be widely tuned. Here, we take advantage of this
property to realize parametric amplification and self-oscillation. The gain of
the parametric amplification can be as high as 18.2 dB and tends to saturate at
high paramet... | 1201.6557v1 |
2012-07-12 | Damping of phase fluctuations in superfluid Bose gases | Using Popov's hydrodynamic approach we derive an effective Euclidean action
for the long-wavelength phase fluctuations of superfluid Bose gases in D
dimensions. We then use this action to calculate the damping of phase
fluctuations at zero temperature as a function of D. For D >1 and wavevectors |
k | << 2 mc (where m ... | 1207.3002v3 |
2014-10-13 | Relaxation damping in oscillating contacts | If a contact of two purely elastic bodies with no sliding (infinite
coefficient of friction) is subjected to superimposed oscillations in the
normal and tangential directions, then a specific damping appears, that is not
dependent on friction or dissipation in the material. We call this effect
"relaxation damping". The... | 1410.3238v1 |
2016-04-29 | Nonlinear Landau damping of wave envelopes in a quantum plasma | The nonlinear theory of Landau damping of electrostatic wave envelopes (WEs)
is revisited in a quantum electron-positron (EP) pair plasma. Starting from a
Wigner-Moyal equation coupled to the Poisson equation and applying the multiple
scale technique, we derive a nonlinear Schr{\"o}dinger (NLS) equation which
governs t... | 1604.08751v4 |
2017-06-11 | Absorbing boundary layers for spin wave micromagnetics | Micromagnetic simulations are used to investigate the effects of different
absorbing boundary layers (ABLs) on spin waves (SWs) reflected from the edges
of a magnetic nano-structure. We define the conditions that a suitable ABL must
fulfill and compare the performance of abrupt, linear, polynomial and tan
hyperbolic da... | 1706.03325v1 |
2017-10-17 | Entropic uncertainty relation under quantum channels with memory | Recently, Xu et al. [Phys. Rev. A 86, 012113(2012)] explored the behavior of
the entropic uncertainty relation under the influence of local unital and
nonunital noisy channels for a class of Bell-diagonal states. We here reform
their results and investigate the entropic uncertainty relation under the
influence of unita... | 1710.06344v1 |
2018-04-15 | Reevaluation of radiation reaction and consequences for light-matter interactions at the nanoscale | In the context of electromagnetism and nonlinear optical interactions damping
is generally introduced as a phenomenological, viscous term that dissipates
energy, proportional to the temporal derivative of the polarization. Here, we
follow the radiation reaction method presented in [G. W. Ford and R. F.
O'Connell, Phys.... | 1804.05369v1 |
2018-12-04 | Atmospheric oscillations provide simultaneous measurement of neutron star mass and radius | Neutron stars with near-Eddington observable luminosities were shown to
harbor levitating atmospheres, suspended above their surface. We report a new
method to simultaneously measure the mass and radius of a neutron star based on
oscillations of such atmospheres. In this paper, we present an analytic
derivation of a fa... | 1812.01299v2 |
2019-01-13 | Nonexistence of global solutions for a weakly coupled system of semilinear damped wave equations in the scattering case with mixed nonlinear terms | In this paper we consider the blow-up of solutions to a weakly coupled system
of semilinear damped wave equations in the scattering case with nonlinearities
of mixed type, namely, in one equation a power nonlinearity and in the other a
semilinear term of derivative type. The proof of the blow-up results is based
on an ... | 1901.04038v1 |
2019-03-03 | Spin wave damping in periodic and quasiperiodic magnonic structures | We investigated the lifetime of spin wave eigenmodes in periodic and
quasiperiodic sequences of Py and Co wires. Those materials differ
significantly in damping coefficients, therefore, the spatial distribution of
the mode amplitude within the structure is important for the lifetime of
collective spin wave excitations.... | 1903.00856v1 |
2019-05-23 | Strauss exponent for semilinear wave equations with scattering space dependent damping | It is believed or conjectured that the semilinear wave equations with
scattering space dependent damping admit the Strauss critical exponent, see
Ikehata-Todorova-Yordanov \cite{ITY}(the bottom in page 2) and
Nishihara-Sobajima-Wakasugi \cite{N2}(conjecture iii in page 4). In this work,
we are devoted to showing the co... | 1905.09445v2 |
2020-06-09 | Logarithmic decay for damped hypoelliptic wave and Schr{ö}dinger equations | We consider damped wave (resp. Schr{\"o}dinger and plate) equations driven by
a hypoelliptic "sum of squares" operator L on a compact manifold and a damping
function b(x). We assume the Chow-Rashevski-H{\"o}rmander condition at rank k
(at most k Lie brackets needed to span the tangent space) together with
analyticity o... | 2006.05122v1 |
2020-11-15 | A Random Matrix Theory Approach to Damping in Deep Learning | We conjecture that the inherent difference in generalisation between adaptive
and non-adaptive gradient methods in deep learning stems from the increased
estimation noise in the flattest directions of the true loss surface. We
demonstrate that typical schedules used for adaptive methods (with low
numerical stability or... | 2011.08181v5 |
2021-04-09 | Nonexistence result for the generalized Tricomi equation with the scale-invariant damping, mass term and time derivative nonlinearity | In this article, we consider the damped wave equation in the
\textit{scale-invariant case} with time-dependent speed of propagation, mass
term and time derivative nonlinearity. More precisely, we study the blow-up of
the solutions to the following equation: $$ (E) \quad u_{tt}-t^{2m}\Delta
u+\frac{\mu}{t}u_t+\frac{\nu^... | 2104.04393v2 |
2021-07-29 | A N-dimensional elastic\viscoelastic transmission problem with Kelvin-Voigt damping and non smooth coefficient at the interface | We investigate the stabilization of a multidimensional system of coupled wave
equations with only one Kelvin Voigt damping. Using a unique continuation
result based on a Carleman estimate and a general criteria of Arendt Batty, we
prove the strong stability of the system in the absence of the compactness of
the resolve... | 2107.13785v1 |
2021-12-27 | Trajectory attractors for 3D damped Euler equations and their approximation | We study the global attractors for the damped 3D Euler--Bardina equations
with the regularization parameter $\alpha>0$ and Ekman damping coefficient
$\gamma>0$ endowed with periodic boundary conditions as well as their damped
Euler limit $\alpha\to0$. We prove that despite the possible non-uniqueness of
solutions of th... | 2112.13691v1 |
2023-01-02 | Fast convex optimization via closed-loop time scaling of gradient dynamics | In a Hilbert setting, for convex differentiable optimization, we develop a
general framework for adaptive accelerated gradient methods. They are based on
damped inertial dynamics where the coefficients are designed in a closed-loop
way. Specifically, the damping is a feedback control of the velocity, or of the
gradient... | 2301.00701v1 |
2023-04-22 | Video analysis of the damped oscillations of Pohl's pendulum | In this paper problems that arose with the introduction of distance learning
in physics at the Technical University of Sofia due to the COVID-19 pandemic
and the imposition of video recording of laboratory exercises are indicated. It
was found that the video for the ''Damped Mechanical Oscillations'' exercise
provides ... | 2304.11390v1 |
2023-11-23 | Friction of a driven chain: Role of momentum conservation, Goldstone and radiation modes | We analytically study friction and dissipation of a driven bead in a 1D
harmonic chain, and analyze the role of internal damping mechanism as well as
chain length. Specifically, we investigate Dissipative Particle Dynamics and
Langevin Dynamics, as paradigmatic examples that do and do not display
translational symmetry... | 2311.14075v1 |
2023-12-14 | Smoluchowski-Kramers diffusion approximation for systems of stochastic damped wave equations with non-constant friction | We consider systems of damped wave equations with a state-dependent damping
coefficient and perturbed by a Gaussian multiplicative noise. Initially, we
investigate their well-posedness, under quite general conditions on the
friction. Subsequently, we study the validity of the so-called
Smoluchowski-Kramers diffusion ap... | 2312.08925v1 |
2024-03-25 | Radiation damping of a Rayleigh scatterer illuminated by a plane wave | We investigate the radiation damping experienced by a dielectric spherical
particle when it is illuminated by an electromagnetic plane wave within the
Rayleigh regime. We derive the equivalent electric dipole of the moving
particle and subsequently calculate the electromagnetic force acting on it from
two different app... | 2403.16618v1 |
2022-06-30 | Effect of a viscous fluid shell on the propagation of gravitational waves | In this paper we show that there are circumstances in which the damping of
gravitational waves (GWs) propagating through a viscous fluid can be highly
significant; in particular, this applies to Core Collapse Supernovae (CCSNe).
In previous work, we used linearized perturbations on a fixed background within
the Bondi-S... | 2206.15103v2 |
2005-07-15 | A Theory of Physical Quantum Computation: The Quantum Computer Condition | In this paper we present a new unified theoretical framework that describes
the full dynamics of quantum computation. Our formulation allows any questions
pertaining to the physical behavior of a quantum computer to be framed, and in
principle, answered. We refer to the central organizing principle developed in
this pa... | 0507141v2 |
2018-12-22 | Spin dynamics of $3d$ and $4d$ impurities embedded in prototypical topological insulators | Topological insulators are insulating bulk materials hosting conducting
surface states. Their magnetic doping breaks time-reversal symmetry and
generates numerous interesting effects such as dissipationless transport.
Nonetheless, their dynamical properties are still poorly understood. Here, we
perform a systematic inv... | 1812.09596v1 |
2016-07-27 | Linear and nonlinear viscoelastic arterial wall models: application on animals | This work deals with the viscoelasticity of the arterial wall and its
influence on the pulse waves. We describe the viscoelasticity by a non-linear
Kelvin-Voigt model in which the coefficients are fitted using experimental time
series of pressure and radius measured on a sheep's arterial network. We
obtained a good agr... | 1607.07973v1 |
2018-09-26 | The influence of oscillations on energy estimates for damped wave models with time-dependent propagation speed and dissipation | The aim of this paper is to derive higher order energy estimates for
solutions to the Cauchy problem for damped wave models with time-dependent
propagation speed and dissipation. The model of interest is \begin{equation*}
u_{tt}-\lambda^2(t)\omega^2(t)\Delta u +\rho(t)\omega(t)u_t=0, \quad
u(0,x)=u_0(x), \,\, u_t(0,x)=... | 1809.10179v2 |
2009-01-12 | Nonlinear Wigner solid transport over superfluid helium under AC conditions | Nonlinear transport properties of the two-dimensional Wigner solid of surface
electrons on superfluid helium are studied for alternating current conditions.
For time-averaged quantities like Fourier coefficients, the field-velocity
characteristics are shown to be qualitatively different as compared to that
found in the... | 0901.1508v1 |
2012-10-03 | Effect of temperature and velocity on superlubricity | We study the effects of temperature and sliding velocity on superlubricity in
numerical simulations of the Frenkel-Kontorova model. We show that resonant
excitations of the phonons in an incommensurate sliding body lead to an
effective friction and to thermal equilibrium with energy distributed over the
internal degree... | 1210.1124v1 |
2015-04-09 | Periodic-coefficient damping estimates, and stability of large-amplitude roll waves in inclined thin film flow | A technical obstruction preventing the conclusion of nonlinear stability of
large-Froude number roll waves of the St. Venant equations for inclined thin
film flow is the "slope condition" of Johnson-Noble-Zumbrun, used to obtain
pointwise symmetrizability of the linearized equations and thereby
high-frequency resolvent... | 1504.02292v1 |
2015-07-24 | Effect of Landau damping on alternative ion-acoustic solitary waves in a magnetized plasma consisting of warm adiabatic ions and non-thermal electrons | Bandyopadhyay and Das [Phys. Plasmas, 9, 465-473, 2002] have derived a
nonlinear macroscopic evolution equation for ion acoustic wave in a magnetized
plasma consisting of warm adiabatic ions and non-thermal electrons including
the effect of Landau damping. In that paper they have also derived the
corresponding nonlinea... | 1507.06733v1 |
2017-03-28 | Singularity formation for the 1D compressible Euler equation with variable damping coefficient | In this paper, we consider some blow-up problems for the 1D Euler equation
with time and space dependent damping. We investigate sufficient conditions on
initial data and the rate of spatial or time-like decay of the coefficient of
damping for the occurrence of the finite time blow-up. In particular, our
sufficient con... | 1703.09821v3 |
2018-06-22 | Optimal Design of Virtual Inertia and Damping Coefficients for Virtual Synchronous Machines | Increased penetration of inverter-connected renewable energy sources (RES) in
the power system has resulted in a decrease in available rotational inertia
which serves as an immediate response to frequency deviation due to
disturbances. The concept of virtual inertia has been proposed to combat this
decrease by enabling... | 1806.08488v1 |
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