publicationDate
stringlengths
1
2.79k
title
stringlengths
1
36.5k
abstract
stringlengths
1
37.3k
id
stringlengths
9
47
2006-12-01
Gilbert damping and spin Coulomb drag in a magnetized electron liquid with spin-orbit interaction
We present a microscopic calculation of the Gilbert damping constant for the magnetization of a two-dimensional spin-polarized electron liquid in the presence of intrinsic spin-orbit interaction. First we show that the Gilbert constant can be expressed in terms of the auto-correlation function of the spin-orbit induced...
0612015v1
2000-03-29
Disagreement between correlations of quantum mechanics and stochastic electrodynamics in the damped parametric oscillator
Intracavity and external third order correlations in the damped nondegenerate parametric oscillator are calculated for quantum mechanics and stochastic electrodynamics (SED), a semiclassical theory. The two theories yield greatly different results, with the correlations of quantum mechanics being cubic in the system's ...
0003131v1
2012-12-18
Using the mobile phone acceleration sensor in Physics experiments: free and damped harmonic oscillations
The mobile acceleration sensor has been used to in Physics experiments on free and damped oscillations. Results for the period, frequency, spring constant and damping constant match very well to measurements obtained by other methods. The Accelerometer Monitor application for Android has been used to get the outputs of...
1212.4403v1
2014-03-19
The effects of time-dependent dissipation on the basins of attraction for the pendulum with oscillating support
We consider a pendulum with vertically oscillating support and time-dependent damping coefficient which varies until reaching a finite final value. The sizes of the corresponding basins of attraction are found to depend strongly on the full evolution of the dissipation. In order to predict the behaviour of the system, ...
1403.4996v1
1995-09-06
Fermi Liquid Damping and NMR Relaxation in Superconductors
Electron collisions for a two dimensional Fermi liquid (FL) are shown to give a quasiparticle damping with interesting frequency and temperature variations in the BCS superconducting state. The spin susceptibility which determines the structure of the damping is analyzed in the normal state for a Hubbard model with a c...
9509028v1
2002-07-26
Landau damping of partially incoherent Langmuir waves
It is shown that partial incoherence, in the form of stochastic phase noise, of a Langmuir wave in an unmagnetized plasma gives rise to a Landau-type damping. Starting from the Zakharov equations, which describe the nonlinear interaction between Langmuir and ion-acoustic waves, a kinetic equation is derived for the pla...
0207050v1
2017-07-30
Blow-up for semilinear damped wave equations with sub-Strauss exponent in the scattering case
It is well-known that the critical exponent for semilinear damped wave equations is Fujita exponent when the damping is effective. Lai, Takamura and Wakasa in 2017 have obtained a blow-up result not only for super-Fujita exponent but also for the one closely related to Strauss exponent when the damping is scaling invar...
1707.09583v3
2018-06-13
Low magnetic damping of ferrimagnetic GdFeCo alloys
We investigate the Gilbert damping parameter for rare earth (RE)-transition metal (TM) ferrimagnets over a wide temperature range. Extracted from the field-driven magnetic domain-wall mobility, the Gilbert damping parameter was as low as 0.0072 and was almost constant across the angular momentum compensation temperatur...
1806.04881v1
2020-05-15
Slow magnetosonic wave absorption by pressure induced ionization-recombination dissipation
A new mechanisms for damping of slow magnetosonic waves (SMW) by pressure induced oscillations of the ionization degree is proposed. An explicit formula for the damping rate is quantitatively derived. Physical conditions where the new mechanism will dominate are briefly discussed. The ionization-recombination damping i...
2005.07730v1
2016-12-30
Spectroscopic evidence of Alfvén wave damping in the off-limb solar corona
We investigate off-limb active region and quiet Sun corona using spectroscopic data. Active region is clearly visible in several spectral lines formed in the temperature range of 1.1--2.8 MK. We derive electron number density using line ratio method, and non-thermal velocity in the off-limb region up to the distance of...
1612.09551v2
1997-06-30
Damped Lyman Alpha Systems at High Redshift and Models of Protogalactic Disks
We employ observationally determined intrinsic velocity widths and column densities of damped Lyman-alpha systems at high redshift to investigate the distribution of baryons in protogalaxies within the context of a standard cold dark matter model. We proceed under the assumption that damped Lyman alpha systems represen...
9706290v1
2019-01-24
Generalization of Stokes-Einstein relation to coordinate dependent damping and diffusivity: An apparent conflict
Brownian motion with coordinate dependent damping and diffusivity is ubiquitous. Understanding equilibrium of a Brownian particle with coordinate dependent diffusion and damping is a contentious area. In this paper, we present an alternative approach based on already established methods to this problem. We solve for th...
1901.08358v4
1996-11-25
Damping rates of hard momentum particles in a cold ultrarelativistic plasma
We compute the damping rates of one-particle excitations in a cold ultrarelativistic plasma to leading order in the coupling constant e for three types of interaction: Yukawa coupling to a massless scalar boson, QED and QCD. Damping rates of charged particles in QED and QCD are of order e^3 mu, while damping rates of o...
9611415v2
2011-06-23
Ratchet effect on a relativistic particle driven by external forces
We study the ratchet effect of a damped relativistic particle driven by both asymmetric temporal bi-harmonic and time-periodic piecewise constant forces. This system can be formally solved for any external force, providing the ratchet velocity as a non-linear functional of the driving force. This allows us to explicitl...
1106.4861v1
2012-10-20
Radiative damping of surface plasmon resonance in spheroidal metallic nanoparticle embedded in a dielectric medium
The local field approach and kinetic equation method is applied to calculate the surface plasmon radiative damping in a spheroidal metal nanoparticle embedded in any dielectric media. The radiative damping of the surface plasmon resonance as a function of the particle radius, shape, dielectric constant of the surroundi...
1210.5647v1
2015-11-13
Magnified Damping under Rashba Spin Orbit Coupling
The spin orbit coupling spin torque consists of the field-like [REF: S.G. Tan et al., arXiv:0705.3502, (2007).] and the damping-like terms [REF: H. Kurebayashi et al., Nature Nanotechnology 9, 211 (2014).] that have been widely studied for applications in magnetic memory. We focus, in this article, not on the spin orbi...
1511.04227v1
2022-05-13
Precession dynamics of a small magnet with non-Markovian damping: Theoretical proposal for an experiment to determine the correlation time
Recent advances in experimental techniques have made it possible to manipulate and measure the magnetization dynamics on the femtosecond time scale which is the same order as the correlation time of the bath degrees of freedom. In the equations of motion of magnetization, the correlation of the bath is represented by t...
2205.06399v1
2006-01-18
Expressions for frictional and conservative force combinations within the dissipative Lagrange-Hamilton formalism
Dissipative Lagrangians and Hamiltonians having Coulomb, viscous and quadratic damping,together with gravitational and elastic terms are presented for a formalism that preserves the Hamiltonian as a constant of the motion. Their derivations are also shown. The resulting L's and H's may prove useful in exploring new typ...
0601133v1
2010-03-28
Damped wave dynamics for a complex Ginzburg-Landau equation with low dissipation
We consider a complex Ginzburg-Landau equation, corresponding to a Gross-Pitaevskii equation with a small dissipation term. We study an asymptotic regime for long-wave perturbations of constant maps of modulus one. We show that such solutions never vanish and we derive a damped wave dynamics for the perturbation.
1003.5375v1
2011-11-20
Null controllability of the structurally damped wave equation with moving point control
We investigate the internal controllability of the wave equation with structural damping on the one dimensional torus. We assume that the control is acting on a moving point or on a moving small interval with a constant velocity. We prove that the null controllability holds in some suitable Sobolev space and after a fi...
1111.4655v1
2013-09-19
Compressible Euler equation with damping on Torus in arbitrary dimensions
We study the exponential stability of constant steady state of isentropic compressible Euler equation with damping on $\mathbb T^n$. The local existence of solutions is based on semigroup theory and some commutator estimates. We propose a new method instead of energy estimates to study the stability, which works equall...
1309.5059v3
2018-09-26
Permutation-invariant constant-excitation quantum codes for amplitude damping
The increasing interest in using quantum error correcting codes in practical devices has heightened the need for designing quantum error correcting codes that can correct against specialized errors, such as that of amplitude damping errors which model photon loss. Although considerable research has been devoted to quan...
1809.09801v4
2019-10-24
Spin waves in ferromagnetic thin films
A spin wave is the disturbance of intrinsic spin order in magnetic materials. In this paper, a spin wave in the Landau-Lifshitz-Gilbert equation is obtained based on the assumption that the spin wave maintains its shape while it propagates at a constant velocity. Our main findings include: (1) in the absence of Gilbert...
1910.11200v1
2019-11-07
Quantum Oscillations of Gilbert Damping in Ferromagnetic/Graphene Bilayer Systems
We study the spin dynamics of a ferromagnetic insulator on which graphene is placed. We show that the Gilbert damping is enhanced by the proximity exchange coupling at the interface. The modulation of the Gilbert damping constant is proportional to the product of the spin-up and spin-down densities of states of graphen...
1911.02775v2
1992-04-06
Comment on ``High Temperature Fermion Propagator -- Resummation and Gauge Dependence of the Damping Rate''
Baier et al. have reported the damping rate of long-wavelength fermionic excitations in high-temperature QED and QCD to be gauge-fixing-dependent even within the resummation scheme due to Braaten and Pisarski. It is shown that this problem is caused by the singular nature of the on-shell expansion of the fermion self-e...
9204210v1
2003-07-02
Harmonic Oscillator Potential to describe Internal Dissipation
Assuming that a constant potential energy function has meaning for a dissipated harmonic oscillator, then an important issue is the time dependence of the turning points. Turning point studies demonstrate that the common model of external (viscous) damping fails to properly describe those many systems where structural ...
0307016v1
2009-12-16
Toward a dynamical shift condition for unequal mass black hole binary simulations
Moving puncture simulations of black hole binaries rely on a specific gauge choice that leads to approximately stationary coordinates near each black hole. Part of the shift condition is a damping parameter, which has to be properly chosen for stable evolutions. However, a constant damping parameter does not account fo...
0912.3125v1
2010-03-09
Damping of Nanomechanical Resonators
We study the transverse oscillatory modes of nanomechanical silicon nitride strings under high tensile stress as a function of geometry and mode index m <= 9. Reproducing all observed resonance frequencies with classical elastic theory we extract the relevant elastic constants. Based on the oscillatory local strain we ...
1003.1868v1
2011-05-20
Magnetization Dissipation in the Ferromagnetic Semiconductor (Ga,Mn)As
We compute the Gilbert damping in (Ga,Mn)As based on the scattering theory of magnetization relaxation. The disorder scattering is included non-perturbatively. In the clean limit, the spin-pumping from the localized d-electrons to the itinerant holes dominates the relaxation processes. In the diffusive regime, the brea...
1105.4148v2
2011-10-12
Acceleration Control in Nonlinear Vibrating Systems based on Damped Least Squares
A discrete time control algorithm using the damped least squares is introduced for acceleration and energy exchange controls in nonlinear vibrating systems. It is shown that the damping constant of least squares and sampling time step of the controller must be inversely related to insure that vanishing the time step ha...
1110.2811v2
2012-03-21
Approximate rogue wave solutions of the forced and damped Nonlinear Schrödinger equation for water waves
We consider the effect of the wind and the dissipation on the nonlinear stages of the modulational instability. By applying a suitable transformation, we map the forced/damped Nonlinear Schr\"odinger (NLS) equation into the standard NLS with constant coefficients. The transformation is valid as long as |{\Gamma}t| \ll ...
1203.4735v1
2014-10-05
Ultimate limit of field confinement by surface plasmon polaritons
We show that electric field confinement in surface plasmon polaritons propagating at the metal/dielectric interfaces enhances the loss due to Landau damping and which effectively limits the degree of confinement itself. We prove that Landau damping and associated with it surface collision damping follow directly from L...
1410.1226v1
2016-04-18
Parameter Estimation of Gaussian-Damped Sinusoids from a Geometric Perspective
The five parameter gaussian damped sinusoid equation is a reasonable model for betatron motion with chromatic decoherence of the proton bunch centroid signal in the ring at the Spallation Neutron Source. A geometric method for efficiently fitting this equation to the turn by turn signals to extract the betatron tune an...
1604.05167v1
2016-07-13
Optimal decay rate for the wave equation on a square with constant damping on a strip
We consider the damped wave equation with Dirichlet boundary conditions on the unit square. We assume the damping to be a characteristic function of a strip. We prove the exact $t^{-4/3}$-decay rate for the energy of classical solutions. This answers a question of Anantharaman and L\'eautaud (2014).
1607.03633v2
2016-09-20
Global existence and asymptotic behavior of solutions to the Euler equations with time-dependent damping
We study the isentropic Euler equations with time-dependent damping, given by $\frac{\mu}{(1+t)^\lambda}\rho u$. Here, $\lambda,\mu$ are two non-negative constants to describe the decay rate of damping with respect to time. We will investigate the global existence and asymptotic behavior of small data solutions to the ...
1609.06286v1
2017-09-24
Suppression of Recurrence in the Hermite-Spectral Method for Transport Equations
We study the unphysical recurrence phenomenon arising in the numerical simulation of the transport equations using Hermite-spectral method. From a mathematical point of view, the suppression of this numerical artifact with filters is theoretically analyzed for two types of transport equations. It is rigorously proven t...
1709.08194v1
2018-05-03
Exact Intrinsic Localized Excitation of an Anisotropic Ferromagnetic Spin Chain in External Magnetic Field with Gilbert Damping, Spin Current and PT-Symmetry
We obtain the exact one-spin intrinsic localized excitation in an anisotropic Heisenberg ferromagnetic spin chain in a constant/variable external magnetic field with Gilbert damping included. We also point out how an appropriate magnitude spin current term in a spin transfer nano-oscillator (STNO) can stabilize the ten...
1805.01230v1
2018-06-08
Brownian motion of magnetic domain walls and skyrmions, and their diffusion constants
Extended numerical simulations enable to ascertain the diffusive behavior at finite temperatures of chiral walls and skyrmions in ultra-thin model Co layers exhibiting symmetric - Heisenberg - as well as antisymmetric - Dzyaloshinskii-Moriya - exchange interactions. The Brownian motion of walls and skyrmions is shown t...
1806.03172v1
2009-04-21
Tensor damping in metallic magnetic multilayers
The mechanism of spin-pumping, described by Tserkovnyak et al., is formally analyzed in the general case of a magnetic multilayer consisting of two or more metallic ferromagnetic (FM) films separated by normal metal (NM) layers. It is shown that the spin-pumping-induced dynamic coupling between FM layers modifies the l...
0904.3150v2
2018-04-20
A Weakly Nonlinear Model for the Damping of Resonantly Forced Density Waves in Dense Planetary Rings
In this paper we address the stability of resonantly forced density waves in dense planetary rings. Already by Goldreich & Tremaine (1978) it has been argued that density waves might be unstable, depending on the relationship between the ring's viscosity and the surface mass density. In the recent paper Schmidt et ...
1804.07674v1
2019-03-02
Complex Stiffness Model of Physical Human-Robot Interaction: Implications for Control of Performance Augmentation Exoskeletons
Human joint dynamic stiffness plays an important role in the stability of performance augmentation exoskeletons. In this paper, we consider a new frequency domain model of the human joint dynamics which features a complex value stiffness. This complex stiffness consists of a real stiffness and a hysteretic damping. We ...
1903.00704v4
2023-12-20
An effective field theory of damped ferromagnetic systems
Using the in-in formalism, we generalize the recently constructed magnetoelastic EFT arXiv:2112.13873 [hep-th] to describe the damping dynamics of ferromagnetic systems at long wavelengths. We find that the standard Gilbert damping term naturally arises as the simplest leading-order symmetry-consistent non-conservative...
2312.13093v1
2003-10-18
Experiment and Dynamic Simulations of Radiation Damping of Laser-polarized liquid 129Xe at low magnetic field in a flow system
Radiation damping is generally observed when the sample with high spin concentration and high gyro-magnetic ratio is placed in a high magnetic field. However, we firstly observed liquid state 129Xe radiation damping using laser-enhanced nuclear polarization at low magnetic field in a flow system in which the polarizati...
0310435v1
2009-08-04
Time domain detection of pulsed spin torque damping reduction
Combining multiple ultrafast spin torque impulses with a 5 nanosecond duration pulse for damping reduction, we observe time-domain precession which evolves from an initial 1 ns duration transient with changing precessional amplitude to constant amplitude oscillations persisting for over 2 ns. These results are consiste...
0908.0481v1
2014-08-15
Linear hyperbolic equations with time-dependent propagation speed and strong damping
We consider a second order linear equation with a time-dependent coefficient c(t) in front of the "elastic" operator. For these equations it is well-known that a higher space-regularity of initial data compensates a lower time-regularity of c(t). In this paper we investigate the influence of a strong dissipation, nam...
1408.3499v1
2017-01-12
Blow-up for semilinear wave equations with the scale invariant damping and super-Fujita exponent
The blow-up for semilinear wave equations with the scale invariant damping has been well-studied for sub-Fujita exponent. However, for super-Fujita exponent, there is only one blow-up result which is obtained in 2014 by Wakasugi in the case of non-effective damping. In this paper we extend his result in two aspects by ...
1701.03232v3
2018-11-29
The Lugiato-Lefever equation with nonlinear damping caused by two photon absorption
In this paper we investigate the effect of nonlinear damping on the Lugiato-Lefever equation $$ \i \partial_t a = -(\i-\zeta) a - da_{xx} -(1+\i\kappa)|a|^2a +\i f $$ on the torus or the real line. For the case of the torus it is shown that for small nonlinear damping $\kappa>0$ stationary spatially periodic solutions ...
1811.12200v3
2020-07-16
Linearized wave-damping structure of Vlasov-Poisson in $\mathbb R^3$
In this paper we study the linearized Vlasov-Poisson equation for localized disturbances of an infinite, homogeneous Maxwellian background distribution in $\mathbb R^3_x \times \mathbb R^3_v$. In contrast with the confined case $\mathbb T^d _x \times \mathbb R_v ^d$, or the unconfined case $\mathbb R^d_x \times \mathbb...
2007.08580v1
2020-11-16
Technology to Counter Online Flaming Based on the Frequency-Dependent Damping Coefficient in the Oscillation Model
Online social networks, which are remarkably active, often experience explosive user dynamics such as online flaming, which can significantly impact the real world. However, countermeasures based on social analyses of the individuals causing flaming are too slow to be effective because of the rapidity with which the in...
2011.08117v1
2021-05-08
A second-order numerical method for Landau-Lifshitz-Gilbert equation with large damping parameters
A second order accurate numerical scheme is proposed and implemented for the Landau-Lifshitz-Gilbert equation, which models magnetization dynamics in ferromagnetic materials, with large damping parameters. The main advantages of this method are associated with the following features: (1) It only solves linear systems o...
2105.03576v1
2024-02-09
Damping of density oscillations from bulk viscosity in quark matter
We study the damping of density oscillations in the quark matter phase that might occur in compact stars. To this end we compute the bulk viscosity and the associated damping time in three-flavor quark matter, considering both nonleptonic and semileptonic electroweak processes. We use two different equations of state o...
2402.06595v1
2019-12-09
Analytical solution of linearized equations of the Morris-Lecar neuron model at large constant stimulation
The classical biophysical Morris-Lecar model of neuronal excitability predicts that upon stimulation of the neuron with a sufficiently large constant depolarizing current there exists a finite interval of the current values where periodic spike generation occurs. Above the upper boundary of this interval, there is four...
1912.04083v4
2003-10-13
Domain wall mobility in nanowires: transverse versus vortex walls
The motion of domain walls in ferromagnetic, cylindrical nanowires is investigated numerically by solving the Landau-Lifshitz-Gilbert equation for a classical spin model in which energy contributions from exchange, crystalline anisotropy, dipole-dipole interaction, and a driving magnetic field are considered. Depending...
0310277v1
2011-03-08
Application of Explicit Symplectic Algorithms to Integration of Damping Oscillators
In this paper an approach is outlined. With this approach some explicit algorithms can be applied to solve the initial value problem of $n-$dimensional damped oscillators. This approach is based upon following structure: for any non-conservative classical mechanical system and arbitrary initial conditions, there exists...
1103.1455v1
2014-05-12
Global Existence and Nonlinear Diffusion of Classical Solutions to Non-Isentropic Euler Equations with Damping in Bounded Domain
We considered classical solutions to the initial boundary value problem for non-isentropic compressible Euler equations with damping in multi-dimensions. We obtained global a priori estimates and global existence results of classical solutions to both non-isentropic Euler equations with damping and their nonlinear diff...
1405.2842v3
2019-10-24
The lifespan of solutions of semilinear wave equations with the scale-invariant damping in two space dimensions
In this paper, we study the initial value problem for semilinear wave equations with the time-dependent and scale-invariant damping in two dimensions. Similarly to the one dimensional case by Kato, Takamura and Wakasa in 2019, we obtain the lifespan estimates of the solution for a special constant in the damping term, ...
1910.11692v2
2020-08-06
Quantum sensing of open systems: Estimation of damping constants and temperature
We determine quantum precision limits for estimation of damping constants and temperature of lossy bosonic channels. A direct application would be the use of light for estimation of the absorption and the temperature of a transparent slab. Analytic lower bounds are obtained for the uncertainty in the estimation, throug...
2008.02728v1
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
2021-06-07
Voltage-control of damping constant in magnetic-insulator/topological-insulator bilayers
The magnetic damping constant is a critical parameter for magnetization dynamics and the efficiency of memory devices and magnon transport. Therefore, its manipulation by electric fields is crucial in spintronics. Here, we theoretically demonstrate the voltage-control of magnetic damping in ferro- and ferrimagnetic-ins...
2106.03332v1
2023-01-22
Boundary stabilization of a vibrating string with variable length
We study small vibrations of a string with time-dependent length $\ell(t)$ and boundary damping. The vibrations are described by a 1-d wave equation in an interval with one moving endpoint at a speed $\ell'(t)$ slower than the speed of propagation of the wave c=1. With no damping, the energy of the solution decays if t...
2301.09086v1
2008-07-23
Damped driven coupled oscillators: entanglement, decoherence and the classical limit
The interaction of (two-level) Rydberg atoms with dissipative QED cavity fields can be described classically or quantum mechanically, even for very low temperatures and mean number of photons, provided the damping constant is large enough. We investigate the quantum-classical border, the entanglement and decoherence of...
0807.3715v1
1999-08-26
Oscillator Strengths and Damping Constants for Atomic Lines in the J and H Bands
We have built a line list in the near-infrared J and H bands (1.00-1.34, 1.49-1.80 um) by gathering a series of laboratory and computed line lists. Oscillator strengths and damping constants were computed or obtained by fitting the solar spectrum. The line list presented in this paper is, to our knowledge, the most c...
9908296v1
1998-07-02
Linear systems with adiabatic fluctuations
We consider a dynamical system subjected to weak but adiabatically slow fluctuations of external origin. Based on the ``adiabatic following'' approximation we carry out an expansion in \alpha/|\mu|, where \alpha is the strength of fluctuations and 1/|\mu| refers to the time scale of evolution of the unperturbed system ...
9807031v1
2004-09-15
Rippled Cosmological Dark Matter from Damped Oscillating Newton Constant
Let the reciprocal Newton 'constant' be an apparently non-dynamical Brans-Dicke scalar field damped oscillating towards its General Relativistic VEV. We show, without introducing additional matter fields or dust, that the corresponding cosmological evolution averagely resembles, in the Jordan frame, the familiar dark r...
0409059v2
2009-08-31
Rigorous Theory of Optical Trapping by an Optical Vortex Beam
We propose a rigorous theory for the optical trapping by optical vortices, which is emerging as an important tool to trap mesoscopic particles. The common perception is that the trapping is solely due to the gradient force, and may be characterized by three real force constants. However, we show that the optical vortex...
0908.4504v1
2009-10-24
Two bodies gravitational system with variable mass and damping-antidamping effect due to star wind
We study two-bodies gravitational problem where the mass of one of the bodies varies and suffers a damping-antidamping effect due to star wind during its motion. A constant of motion, a Lagrangian and a Hamiltonian are given for the radial motion of the system, and the period of the body is studied using the constant o...
0910.4684v2
2012-03-02
Damping-Antidamping Effect on Comets Motion
We make an observation about Galilean transformation on a 1-D mass variable systems which leads us to the right way to deal with mass variable systems. Then using this observation, we study two-bodies gravitational problem where the mass of one of the bodies varies and suffers a damping-antidamping effect due to star w...
1203.0495v2
2012-03-09
Collective Light Emission of a Finite Size Atomic Chain
Radiative properties of collective electronic states in a one dimensional atomic chain are investigated. Radiative corrections are included with emphasize put on the effect of the chain size through the dependence on both the number of atoms and the lattice constant. The damping rates of collective states are calculate...
1203.2094v1
2022-11-18
Energy decay estimates for an axially travelling string damped at one end
We study the small vibrations of an axially travelling string with a dashpoint damping at one end. The string is modelled by a wave equation in a time-dependent interval with two endpoints moving at a constant speed $v$. For the undamped case, we obtain a conserved functional equivalent to the energy of the solution. W...
2211.10537v1
2023-04-19
Inviscid damping of monotone shear flows for 2D inhomogeneous Euler equation with non-constant density in a finite channel
We prove the nonlinear inviscid damping for a class of monotone shear flows with non-constant background density for the two-dimensional ideal inhomogeneous fluids in $\mathbb{T}\times [0,1]$ when the initial perturbation is in Gevrey-$\frac{1}{s}$ ($\frac{1}{2}<s<1$) class with compact support.
2304.09841v2
2023-07-27
Best Ulam constants for damped linear oscillators with variable coefficients
This study uses an associated Riccati equation to study the Ulam stability of non-autonomous linear differential vector equations that model the damped linear oscillator. In particular, the best (minimal) Ulam constants for these non-autonomous linear differential vector equations are derived. These robust results appl...
2307.15103v1
2019-11-02
Soft contribution to the damping rate of a hard photon in a weakly magnetized hot medium
We consider weakly magnetized hot QED plasma comprising electrons and positrons. There are three distinct dispersive (longitudinal and two transverse) modes of a photon in a thermo-magnetic medium. At lowest order in coupling constant, photon is damped in this medium via Compton scattering and pair creation process. We...
1911.00744v2
2023-06-05
Damping of coronal oscillations in self-consistent 3D radiative MHD simulations of the solar atmosphere
Oscillations are abundant in the solar corona. Coronal loop oscillations are typically studied using highly idealised models of magnetic flux tubes. In order to improve our understanding of coronal oscillations, it is necessary to consider the effect of realistic magnetic field topology and density structuring. We anal...
2306.02770v1
2006-06-05
Phenomenological theory of current driven exchange switching in ferromagnetic nanojunctions
Phenomenological approach is developed in the theory of spin-valve type ferromagnetic junctions to describe exchange switching by current flowing perpendicular to interfaces. Forward and backward current switching effects are described and they may be principally different in nature. Mobile electron spins are considere...
0606102v2
2009-01-15
The sound damping constant for generalized theories of gravity
The near-horizon metric for a black brane in Anti-de Sitter (AdS) space and the metric near the AdS boundary both exhibit hydrodynamic behavior. We demonstrate the equivalence of this pair of hydrodynamic systems for the sound mode of a conformal theory. This is first established for Einstein's gravity, but we then sho...
0901.2191v1
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
2005-04-22
Constraint damping in the Z4 formulation and harmonic gauge
We show that by adding suitable lower-order terms to the Z4 formulation of the Einstein equations, all constraint violations except constant modes are damped. This makes the Z4 formulation a particularly simple example of a lambda-system as suggested by Brodbeck et al. We also show that the Einstein equations in harmon...
0504114v2
2008-10-21
On Wigner functions and a damped star product in dissipative phase-space quantum mechanics
Dito and Turrubiates recently introduced an interesting model of the dissipative quantum mechanics of a damped harmonic oscillator in phase space. Its key ingredient is a non-Hermitian deformation of the Moyal star product with the damping constant as deformation parameter. We compare the Dito-Turrubiates scheme with p...
0810.3893v1
2015-02-01
Nonlocal Damping of Helimagnets in One-Dimensional Interacting Electron Systems
We investigate the magnetization relaxation of a one-dimensional helimagnetic system coupled to interacting itinerant electrons. The relaxation is assumed to result from the emission of plasmons, the elementary excitations of the one-dimensional interacting electron system, caused by slow changes of the magnetization p...
1502.00268v2
2017-07-08
Nonlinear dynamics of damped DNA systems with long-range interactions
We investigate the nonlinear dynamics of a damped Peyrard-Bishop DNA model taking into account long-range interactions with distance dependence |l|^-s on the elastic coupling constant between different DNA base pairs. Considering both Stokes and long-range hydrodynamical damping forces, we use the discrete difference o...
1707.02425v1
2017-09-12
Temperature effects on MIPs in the BGO calorimeters of DAMPE
In this paper, we presented a study of temperature effects on BGO calorimeters using proton MIP's collected in the first year operation of DAMPE. By directly comparing MIP calibration constants used by DAMPE data production pipe line, we found an experimental relation between temperature and signal amplitudes of each B...
1709.03735v2
2018-04-02
Anisotropic Gilbert damping in perovskite La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ thin film
The viscous Gilbert damping parameter governing magnetization dynamics is of primary importance for various spintronics applications. Although, the damping constant is believed to be anisotropic by theories. It is commonly treated as a scalar due to lack of experimental evidence. Here, we present an elaborate angle dep...
1804.00554v1
2019-07-10
Determination of the damping co-efficient of electrons in optically transparent glasses at the true resonance frequency in the ultraviolet from an analysis of the Lorentz-Maxwell model of dispersion
The Lorentz-Maxwell model of dispersion of light has been analyzed in this paper to determine the true resonance frequency in the ultraviolet for the electrons in optically transparent glasses and the damping coefficient at this frequency. For this we needed the refractive indices of glass in the optical frequency rang...
1907.04499v1
2019-07-10
The superior role of the Gilbert damping on the signal-to-noise ratio in heat-assisted magnetic recording
In magnetic recording the signal-to-noise ratio (SNR) is a good indicator for the quality of written bits. However, a priori it is not clear which parameters have the strongest influence on the SNR. In this work, we investigate the role of the Gilbert damping on the SNR. Grains consisting of FePt like hard magnetic mat...
1907.04577v2
2019-07-21
Critical Thresholds in One Dimensional Damped Euler-Poisson Systems
This paper is concerned with the critical threshold phenomenon for one dimensional damped, pressureless Euler-Poisson equations with electric force induced by a constant background, originally studied in [S. Engelberg and H. Liu and E. Tadmor, Indiana Univ. Math. J., 50:109--157, 2001]. A simple transformation is used ...
1907.09039v1
2022-06-17
Resolvent estimates for the one-dimensional damped wave equation with unbounded damping
We study the generator $G$ of the one-dimensional damped wave equation with unbounded damping. We show that the norm of the corresponding resolvent operator, $\| (G - \lambda)^{-1} \|$, is approximately constant as $|\lambda| \to +\infty$ on vertical strips of bounded width contained in the closure of the left-hand sid...
2206.08820v2
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
2024-01-01
Magnon Damping Minimum and Logarithmic Scaling in a Kondo-Heisenberg Model
Recently, an anomalous temperature evolution of spin wave excitations has been observed in a van der Waals metallic ferromagnet Fe$_3$GeTe$_2$ (FGT) [S. Bao, et al., Phys. Rev. X 12, 011022 (2022)], whose theoretical understanding yet remains elusive. Here we study the spin dynamics of a ferromagnetic Kondo-Heisenberg ...
2401.00758v1
2024-01-19
Upper bound of the lifespan of the solution to the nonlinear fractional wave equations with time-dependent damping
In this paper, we study the Cauchy problem of the nonlinear wave equation with fractional Laplacian and time-dependent damping. Firstly, we derive the weighted Sobolev estimate of the solution operators for the linear wave equation with the damping of constant coefficient, and prove the local existence and uniqueness i...
2401.10552v1
2024-03-13
Effects of wave damping and finite perpendicular scale on three-dimensional Alfvén wave parametric decay in low-beta plasmas
Shear Alfven wave parametric decay instability (PDI) provides a potential path toward significant wave dissipation and plasma heating. However, fundamental questions regarding how PDI is excited in a realistic three-dimensional (3D) open system and how critically the finite perpendicular wave scale -- as found in both ...
2403.08179v1
2001-09-05
Nuclear resonant scattering of Synchrotron radiation from nuclei in the Browninan motion
The time evolution of the coherent forward scattering of Synchrotron radiation for resonant nuclei in Brownian motion is studied . Apart from target thickness, the appearance of dynamical beats also depends on $\alpha$ which is the ratio of harmonic force constant to the damping force constant of a harmonic oscillator ...
0109074v2
2007-02-07
Relativistic r-modes and shear viscosity
We derive the relativistic equations for stellar perturbations, including in a consistent way shear viscosity in the stress-energy tensor, and we numerically integrate our equations in the case of large viscosity. We consider the slow rotation approximation, and we neglect the coupling between polar and axial perturbat...
0702040v1
2009-08-19
Nonlinear viscoelastic wave propagation: an extension of Nearly Constant Attenuation (NCQ) models
Hysteretic damping is often modeled by means of linear viscoelastic approaches such as "nearly constant Attenuation (NCQ)" models. These models do not take into account nonlinear effects either on the stiffness or on the damping, which are well known features of soil dynamic behavior. The aim of this paper is to propos...
0908.2715v2
2012-05-06
Fractional wave equation and damped waves
In this paper, a fractional generalization of the wave equation that describes propagation of damped waves is considered. In contrast to the fractional diffusion-wave equation, the fractional wave equation contains fractional derivatives of the same order $\alpha,\ 1\le \alpha \le 2$ both in space and in time. We show ...
1205.1199v2
2013-04-22
Constant residual electrostatic electron plasma mode in Vlasov-Ampere system
In a collisionless Vlasov-Poisson (V-P) electron plasma system, two types of modes for electric field perturbation exist: the exponentially Landau damped electron plasma waves and the initial-value sensitive ballistic modes. Here, the V-P system is modified slightly to a Vlasov-Ampere (V-A) system. A new constant resid...
1304.5883v2
2014-02-28
A new way to evaluate x-ray Brillouin scattering data
Making use of the classical second moment sum rule, it is possible to convert a series of constant-Q x-ray Brillouin scattering scans (Q momentum transfer) into a series of constant frequency scans over the measured $Q$ range. The method is applied to literature results for the phonon dispersion in liquid vitreous sili...
1402.7237v1
2014-08-27
Quasi-particle Lifetime in a Mixture of Bose and Fermi Superfluids
In this letter, to reveal the effect of quasi-particle interactions in a Bose-Fermi superfluid mixture, we consider the lifetime of quasi-particle of Bose superfluid due to its interaction with quasi-particles in Fermi superfluid. We find that this damping rate, i.e. inverse of the lifetime, has quite different thresho...
1408.6419v1
2015-02-24
High Quality Yttrium Iron Garnet Grown by Room Temperature Pulsed Laser Deposition and Subsequent Annealing
We have investigated recrystallization of amorphous Yttrium Iron Garnet (YIG) by annealing in oxygen atmosphere. Our findings show that well below the melting temperature the material transforms into a fully epitaxial layer with exceptional quality, both structural and magnetic.\\ In ferromagnetic resonance (FMR) ultra...
1502.06724v2
2015-03-04
Critical current destabilizing perpendicular magnetization by the spin Hall effect
The critical current needed to destabilize the magnetization of a perpendicular ferromagnet via the spin Hall effect is studied. Both the dampinglike and fieldlike torques associated with the spin current generated by the spin Hall effect is included in the Landau-Lifshitz-Gilbert equation to model the system. In the a...
1503.01478v2
2015-09-06
Study of spin dynamics and damping on the magnetic nanowire arrays with various nanowire widths
We investigate the spin dynamics including Gilbert damping in the ferromagnetic nanowire arrays. We have measured the ferromagnetic resonance of ferromagnetic nanowire arrays using vector-network analyzer ferromagnetic resonance (VNA-FMR) and analyzed the results with the micromagnetic simulations. We find excellent ag...
1509.01807v1