publicationDate
stringlengths
1
2.79k
title
stringlengths
1
36.5k
abstract
stringlengths
1
37.3k
id
stringlengths
9
47
2005-06-11
Quantum damped oscillator II: Bateman's Hamiltonian vs. 2D Parabolic Potential Barrier
We show that quantum Bateman's system which arises in the quantization of a damped harmonic oscillator is equivalent to a quantum problem with 2D parabolic potential barrier known also as 2D inverted isotropic oscillator. It turns out that this system displays the family of complex eigenvalues corresponding to the pole...
0506091v1
2005-06-27
Entanglement of pair cat states and teleportation
The entanglement of pair cat states in the phase damping channel is studied by employing the relative entropy of entanglement. It is shown that the pair cat states can always be distillable in the phase damping channel. Furthermore, we analyze the fidelity of teleportation for the pair cat states by using joint measure...
0506217v1
2005-07-21
Entanglement versus mixedness for coupled qubits under a phase damping channel
Quantification of entanglement against mixing is given for a system of coupled qubits under a phase damping channel. A family of pure initial joint states is defined, ranging from pure separable states to maximally entangled state. An ordering of entanglement measures is given for well defined initial state amount of e...
0507212v2
2005-10-20
Overdamping by weakly coupled environments
A quantum system weakly interacting with a fast environment usually undergoes a relaxation with complex frequencies whose imaginary parts are damping rates quadratic in the coupling to the environment, in accord with Fermi's ``Golden Rule''. We show for various models (spin damped by harmonic-oscillator or random-matri...
0510164v1
2006-06-07
Comment on "Optimum Quantum Error Recovery using Semidefinite Programming"
In a recent paper ([1]=quant-ph/0606035) it is shown how the optimal recovery operation in an error correction scheme can be considered as a semidefinite program. As a possible future improvement it is noted that still better error correction might be obtained by optimizing the encoding as well. In this note we present...
0606059v1
2006-10-16
Local noise can enhance entanglement teleportation
Recently we have considered two-qubit teleportation via mixed states of four qubits and defined the generalized singlet fraction. For single-qubit teleportation, Badziag {\em et al.} [Phys. Rev. A {\bf 62}, 012311 (2000)] and Bandyopadhyay [Phys. Rev. A {\bf 65}, 022302 (2002)] have obtained a family of entangled two-q...
0610125v1
2006-11-24
High fidelity transfer of an arbitrary quantum state between harmonic oscillators
It is shown that by switching a specific time-dependent interaction between a harmonic oscillator and a transmission line (a waveguide, an optical fiber, etc.) the quantum state of the oscillator can be transferred into that of another oscillator coupled to the distant other end of the line, with a fidelity that is ind...
0611249v1
2006-12-05
Quantum Brownian motion and the second law of thermodynamics
We consider a single harmonic oscillator coupled to a bath at zero temperature. As is well known, the oscillator then has a higher average energy than that given by its ground state. Here we show analytically that for a damping model with arbitrarily discrete distribution of bath modes and damping models with continuou...
0612038v1
2007-05-08
Minimal qudit code for a qubit in the phase-damping channel
Using the stabilizer formalism we construct the minimal code into a D-dimensional Hilbert space (qudit) to protect a qubit against phase damping. The effectiveness of this code is then studied by means of input-output fidelity.
0705.1099v3
2007-05-10
Anomalous Diffusion of particles with inertia in external potentials
Recently a new type of Kramers-Fokker-Planck Equation has been proposed [R. Friedrich et al. Phys. Rev. Lett. {\bf 96}, 230601 (2006)] describing anomalous diffusion in external potentials. In the present paper the explicit cases of a harmonic potential and a velocity-dependend damping are incorporated. Exact relations...
0705.1480v1
2007-06-13
Polymers in a vacuum
In a variety of situations, isolated polymer molecules are found in a vacuum and here we examine their properties. Angular momentum conservation is shown to significantly alter the average size of a chain and its conservation is only broken slowly by thermal radiation. The time autocorrelation for monomer position osci...
0706.2001v1
2007-07-15
Enhancement of Carrier Mobility in Semiconductor Nanostructures by Dielectric Engineering
We propose a technique for achieving large improvements in carrier mobilities in 2- and 1-dimensional semiconductor nanostructures by modifying their dielectric environments. We show that by coating the nanostructures with high-$\kappa$ dielectrics, scattering from Coulombic impurities can be strongly damped. Though sc...
0707.2244v1
2007-07-23
Causal vs. Noncausal Description of Nonlinear Wave Mixing; Resolving the Damping-Sign Controversy
Frequency-domain nonlinear wave mixing processes may be described either using response functions whereby the signal is generated after all interactions with the incoming fields, or in terms of scattering amplitudes where all fields are treated symetrically with no specific time ordering. Closed Green's function expres...
0707.3458v1
2007-07-27
Excitation of spin dynamics by spin-polarized current in vortex state disks
A spin-polarized current with the polarization perpendicular to the plane of a vortex-state disk results in renormalization of the effective damping for a given magnetization mode, and the effective damping becomes zero if the current exceeds a threshold value. The lowest threshold current corresponds to the lowest fre...
0707.4128v1
2007-09-11
Frequency and damping of the Scissors Mode of a Fermi gas
We calculate the frequency and damping of the scissors mode in a classical gas as a function of temperature and coupling strength. Our results show good agreement with the main features observed in recent measurements of the scissors mode in an ultracold gas of $^6$Li atoms. The comparison between theory and experiment...
0709.1617v2
2007-09-14
Strong collisionless damping of the low-velocity branch of electromagnetic wave in plasmas with Maxwellian-like electron velocity distribution function
After approximate replacing of Maxwellian distribution exponent with the rational polynomial fraction we have obtained precise analytical expression for and calculated the principal value of logarithmically divergent integral in the electron wave dispersion equation. At the same time our calculations have shown the pre...
0709.2206v1
2007-09-14
Plasmons, plasminos and Landau damping in a quasiparticle model of the quark-gluon plasma
A phenomenological quasiparticle model is surveyed for 2+1 quark flavors and compared with recent lattice QCD results. Emphasis is devoted to the effects of plasmons, plasminos and Landau damping. It is shown that thermodynamic bulk quantities, known at zero chemical potential, can uniquely be mapped towards nonzero ch...
0709.2262v2
2007-10-04
Activation of additional energy dissipation processes in the magnetization dynamics of epitaxial chromium dioxide films
The precessional magnetization dynamics of a chromium dioxide$(100)$ film is examined in an all-optical pump-probe setup. The frequency dependence on the external field is used to extract the uniaxial in-plane anisotropy constant. The damping shows a strong dependence on the frequency, but also on the laser pump fluenc...
0710.0986v2
2007-10-24
Spin dynamics of a trapped spin-1 Bose Gas above the Bose-Einstein transition temperature
We study collective spin oscillations in a spin-1 Bose gas above the Bose-Einstein transition temperature. Starting from the Heisenberg equation of motion, we derive a kinetic equation describing the dynamics of a thermal gas with the spin-1 degree of freedom. Applying the moment method to the kinetic equation, we stud...
0710.4419v2
2007-11-19
Nonlinear mode conversion in monodomain magnetic squares
Modifications of spatial distributions of dynamic magnetization corresponding to spinwave eigenmodes of magnetic squares subjected to a strong microwave excitation field have been studied experimentally and theoretically. We show that an increase of the excitation power leads to a nonlinear generation of long-wavelengt...
0711.2872v1
2007-12-18
Weibel Instabilities in Dense Quantum Plasmas
The quantum effect on the Weibel instability in an unmagnetized plasma is presented. Our analysis shows that the quantum effect tends to stabilize the Weibel instability in the hydrodynamic regime, whereas it produces a new oscillatory instability in the kinetic regime. A novel effect the quantum damping, which is asso...
0712.2874v1
2008-01-18
A qualitative perspective on the dynamics of a single-Cooper-pair box with a phase-damped cavity
In a recent paper Dajka, et.al., [J. Phys. A \textbf{40}, F879 (2007)] predicted that some composite systems can be entangled forever even if coupled with a thermal bath. We analyze the transient entanglement of a single-Cooper-pair box biased by a classical voltage and irradiated by a quantized field and find the unus...
0801.2905v2
2008-02-28
Current driven spin-wave instability triggered by the anomalous Hall effect
We studied the effect of strong electric current on spin waves interacting relativistically with the current. The spin-wave spectrum is calculated at arbitrary direction of the wave vector. It is shown that the alternating Hall current generated by the alternating magnetic moment of the spin waves, reduces the spin-wav...
0802.4150v1
2008-03-31
Spectral Modeling of Magnetohydrodynamic Turbulent Flows
We present a dynamical spectral model for Large Eddy Simulation of the incompressible magnetohydrodynamic (MHD) equations based on the Eddy Damped Quasi Normal Markovian approximation. This model extends classical spectral Large Eddy Simulations for the Navier-Stokes equations to incorporate general (non Kolmogorovian)...
0803.4499v1
2008-04-10
Trapped Phase-Segregated Bose-Fermi Mixtures and their Collective Excitations
Recent progress in the field of ultracold gases has allowed the creation of phase-segregated Bose-Fermi systems. We present a theoretical study of their collective excitations at zero temperature. As the fraction of fermion to boson particle number increases, the collective mode frequencies take values between those fo...
0804.1759v2
2008-04-14
Size dependence of multipolar plasmon resonance frequencies and damping rates in simple metal spherical nanoparticles
Multipolar plasmon oscillation frequencies and corresponding damping rates for nanospheres formed of the simplest free-electron metals are studied. The possibility of controlling plasmon features by choosing the size and dielectric properties of the sphere surroundings is discussed. Optical properties of the studied me...
0804.2156v1
2008-06-05
Thermally Assisted Spin Hall Effect
The spin polarized charge transport is systematically analyzed as a thermally driven stochastic process. The approach is based on Kramers' equation describing the semiclassical motion under the inclusion of stochastic and damping forces. Due to the relativistic spin-orbit coupling the damping experiences a relativistic...
0806.0948v1
2008-06-13
General Solution of the Quantum Damped Harmonic Oscillator II : Some Examples
In the preceding paper (arXiv : 0710.2724 [quant-ph]) we have constructed the general solution for the master equation of quantum damped harmonic oscillator, which is given by the complicated infinite series in the operator algebra level. In this paper we give the explicit and compact forms to solutions (density operat...
0806.2169v1
2008-08-27
Entanglement dynamics of two-qubit system in different types of noisy channels
In this paper, we study entanglement dynamics of a two-qubit extended Werner-like state locally interacting with independent noisy channels, i.e., amplitude damping, phase damping and depolarizing channels. We show that the purity of initial entangled state has direct impacts on the entanglement robustness in each nois...
0808.3690v1
2008-09-01
Heatons induced by attosecond laser pulses
In this paper the dynamics of the interaction of attosecond laser pulses with matter is investigated. It will be shown that the master equation: modified Klein-Gordon equation describes the propagation of the heatons. Heatons are the thermal wave packets. When the duration of the laser pulses is of the order of attosec...
0809.0204v1
2008-10-09
Heat conduction in 2D strongly-coupled dusty plasmas
We perform non-equilibrium simulations to study heat conduction in two-dimensional strongly coupled dusty plasmas. Temperature gradients are established by heating one part of the otherwise equilibrium system to a higher temperature. Heat conductivity is measured directly from the stationary temperature profile and hea...
0810.1623v2
2008-10-21
Structurally damped plate and wave equations with random point force in arbitrary space dimensions
In this paper we consider structurally damped plate and wave equations with point and distributed random forces. In order to treat space dimensions more than one, we work in the setting of $L^q$--spaces with (possibly small) $q\in(1,2)$. We establish existence, uniqueness and regularity of mild and weak solutions to th...
0810.3898v2
2008-11-05
Spectral function and quasi-particle damping of interacting bosons in two dimensions
We employ the functional renormalization group to study dynamical properties of the two-dimensional Bose gas. Our approach is free of infrared divergences, which plague the usual diagrammatic approaches, and is consistent with the exact Nepomnyashchy identity, which states that the anomalous self-energy vanishes at zer...
0811.0624v2
2008-11-13
Existence of weak solutions to the Cauchy problem of a semilinear wave equation with supercritical interior source and damping
In this paper we show existence of finite energy solutions for the Cauchy problem associated with a semilinear wave equation with interior damping and supercritical source terms. The main contribution consists in dealing with super-supercritical source terms (terms of the order of $|u|^p$ with $p\geq 5$ in $n=3$ dimens...
0811.2151v1
2008-11-17
Asymptotic stability and blow up for a semilinear damped wave equation with dynamic boundary conditions
In this paper we consider a multi-dimensional wave equation with dynamic boundary conditions, related to the Kelvin-Voigt damping. Global existence and asymptotic stability of solutions starting in a stable set are proved. Blow up for solutions of the problem with linear dynamic boundary conditions with initial data in...
0811.2783v3
2008-11-19
Weyl laws for partially open quantum maps
We study a toy model for "partially open" wave-mechanical system, like for instance a dielectric micro-cavity, in the semiclassical limit where ray dynamics is applicable. Our model is a quantized map on the 2-dimensional torus, with an additional damping at each time step, resulting in a subunitary propagator, or "dam...
0811.3134v2
2008-12-16
A picogram and nanometer scale photonic crystal opto-mechanical cavity
We describe the design, fabrication, and measurement of a cavity opto-mechanical system consisting of two nanobeams of silicon nitride in the near-field of each other, forming a so-called "zipper" cavity. A photonic crystal patterning is applied to the nanobeams to localize optical and mechanical energy to the same cub...
0812.2953v1
2009-02-03
Freezing of spin dynamics in underdoped cuprates
The Mori's memory function approach to spin dynamics in doped antiferromagnetic insulator combined with the assumption of temperature independent static spin correlations and constant collective mode damping leads to w/T scaling in a broad range. The theory involving a nonuniversal scaling parameter is used to analyze ...
0902.0546v1
2009-02-12
Discrete breathers in a forced-damped array of coupled pendula: Modeling, Computation and Experiment
In this work, we present a mechanical example of an experimental realization of a stability reversal between on-site and inter-site centered localized modes. A corresponding realization of a vanishing of the Peierls-Nabarro barrier allows for an experimentally observed enhanced mobility of the localized modes near the ...
0902.2129v1
2009-03-08
Enhancement of transmission rates in quantum memory channels with damping
We consider the transfer of quantum information down a single-mode quantum transmission line. Such quantum channel is modeled as a damped harmonic oscillator, the interaction between the information carriers -a train of N qubits- and the oscillator being of the Jaynes-Cummings kind. Memory effects appear if the state o...
0903.1424v1
2009-03-15
A variational approach to strongly damped wave equations
We discuss a Hilbert space method that allows to prove analytical well-posedness of a class of linear strongly damped wave equations. The main technical tool is a perturbation lemma for sesquilinear forms, which seems to be new. In most common linear cases we can furthermore apply a recent result due to Crouzeix--Haase...
0903.2599v2
2009-03-30
Damping of Exciton Rabi Rotations by Acoustic Phonons in Optically Excited InGaAs/GaAs Quantum Dots
We report experimental evidence identifying acoustic phonons as the principal source of the excitation-induced-dephasing (EID) responsible for the intensity damping of quantum dot excitonic Rabi rotations. The rate of EID is extracted from temperature dependent Rabi rotation measurements of the ground-state excitonic t...
0903.5278v2
2009-05-13
Landau damping
In this note we present the main results from the recent work hal-00376547/arXiv:0904.2760, which for the first time establish Landau damping in a nonlinear context.
0905.2167v2
2009-05-13
Amortissement Landau
Dans cette note nous pr\'esentons les principaux r\'esultats du r\'ecent travail hal-00376547/arXiv:0904.2760, o\`u le ph\'enom\`ene d'amortissement Landau est pour la premi\`ere fois \'etabli dans un contexte non lin\'eaire. ----- In this note we present the main results from the recent work hal-00376547 / arXiv:0...
0905.2168v2
2009-06-27
Effect of Bohm potential on a charged gas
Bohm's interpretation of Quantum Mechanics leads to the derivation of a Quantum Kinetic Equation (QKE): in the present work, propagation of waves in charged quantum gases is investigated starting from this QKE. Dispersion relations are derived for fully and weakly degenerate fermions and bosons (these latter above crit...
0906.5061v1
2009-07-14
Quantum Monty Hall problem under decoherence
We study the effect of decoherence on quantum Monty Hall problem under the influence of amplitude damping, depolarizing and dephasing channels. It is shown that under the effect of decoherence, there is a Nash equilibrium of the game in case of depolarizing channel for Alice's quantum strategy. Where as in case of deph...
0907.2293v1
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
2009-09-11
Energy decay for the damped wave equation under a pressure condition
We establish the presence of a spectral gap near the real axis for the damped wave equation on a manifold with negative curvature. This results holds under a dynamical condition expressed by the negativity of a topological pressure with respect to the geodesic flow. As an application, we show an exponential decay of th...
0909.2093v1
2009-09-12
Signature of smooth transition from diabatic to adiabatic states in heavy-ion fusion reactions at deep subbarrier energies
We propose a novel extension of the standard coupled-channels framework for heavy-ion reactions in order to analyze fusion reactions at deep subbarrier incident energies. This extension simulates a smooth transition between the diabatic two-body and the adiabatic one-body states. To this end, we damp gradually the off-...
0909.2298v1
2009-10-14
Plasmon-phonon Strongly-Coupled Mode in Epitaxial Graphene
We report the dispersion measurements, using angle-resolved reflection electron-energy-loss-spectroscopy (AREELS), on two-dimensional (2D) plasmons in single and multilayer graphene which couple strongly to surface optical phonon (FK phonon) modes of silicon carbide substrate. The coupled modes show discrete dispersion...
0910.2735v1
2009-10-23
Collective Enhancement and Suppression of Excitation Decay in Optical Lattices
We calculate radiative lifetimes of collective electronic excitations of atoms in an infinite one dimensional lattice. The translational symmetry along the lattice restricts the photon wave vector component parallel to the lattice to the exciton wave number and thus the possible emission directions. The resulting radia...
0910.4501v1
2009-10-24
Global Attractor for Weakly Damped Forced KdV Equation in Low Regularity on T
In this paper we consider the long time behavior of the weakly damped, forced Korteweg-de Vries equation in the Sololev spaces of the negative indices in the periodic case. We prove that the solutions are uniformly bounded in $\dot{H}^s(\T)$ for $s>-\dfrac{1}{2}$. Moreover, we show that the solution-map possesses a glo...
0910.4652v1
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
2009-12-15
Distillability sudden death in qutrit-qutrit systems under amplitude damping
Recently it has been discovered that certain two-qutrit entangled states interacting with global and/or multi-local decoherence undergo distillability sudden death (DSD). We investigate this phenomenon for qutrit-qutrit systems interacting with statistically independent zero-temperature reservoirs. We show that certain...
0912.2868v1
2009-12-15
Global Controllability of Multidimensional Rigid Body by Few Torques
We study global controllability of 'rotating' multidimensional rigid body (MRB) controlled by application of few torques. Study by methods of geometric control requires analysis of algebraic structure introduced by the quadratic term of Euler-Frahm equation. We discuss problems, which arise in the course of this analys...
0912.2900v1
2010-02-05
Damping Effect of Electromagnetic Radiation and Time-Dependent Schrodinger Equation
The inexactness of the time-dependent Schr\"odinger equation of a charged particle in an external electromagnetic field is discussed in terms of the damping effect of the radiation. A possible improvement is to add a nonlinear term representing this effect to the linear Schr\"odinger equation. Conditions for the nonlin...
1002.1116v3
2010-02-05
Uniform stabilization in weighted Sobolev spaces for the KdV equation posed on the half-line
Studied here is the large-time behavior of solutions of the Korteweg-de Vries equation posed on the right half-line under the effect of a localized damping. Assuming as in \cite{linares-pazoto} that the damping is active on a set $(a_0,+\infty)$ with $a_0>0$, we establish the exponential decay of the solutions in the w...
1002.1127v1
2010-03-28
Giant magnetic broadening of ferromagnetic resonance in a GMR Co/Ag/Co/Gd quadlayer
Both magnetic-resonance damping and the giant magnetoresistance effect have been predicted to be strongly affected by the local density of states in thin ferromagnetic films. We employ the antiferromagnetic coupling between Co and Gd to provide a spontaneous change from parallel to antiparallel alignment of two Co film...
1003.5344v1
2010-04-04
Quantum information reclaiming after amplitude damping
We investigate the quantum information reclaim from the environment after amplitude damping has occurred. In particular we address the question of optimal measurement on the environment to perform the best possible correction on two and three dimensional quantum systems. Depending on the dimension we show that the enta...
1004.0497v1
2010-04-09
Validity of Landauer's principle in the quantum regime
We demonstrate the validity of Landauer's erasure principle in the strong coupling quantum regime by treating the system-reservoir interaction in a consistent way. We show that the initial coupling to the reservoir modifies both energy and entropy of the system and provide explicit expressions for the latter in the cas...
1004.1599v1
2010-04-22
Critical exponent for damped wave equations with nonlinear memory
We consider the Cauchy problem in $\mathbb{R}^n,$ $n\geq 1,$ for a semilinear damped wave equation with nonlinear memory. Global existence and asymptotic behavior as $t\rightarrow\infty$ of small data solutions have been established in the case when $1\leq n\leq3.$ Moreover, we derive a blow-up result under some positi...
1004.3850v4
2010-04-26
Entanglement of a two-particle Gaussian state interacting with a heat bath
The effect of a thermal reservoir is investigated on a bipartite Gaussian state. We derive a pre-Lindblad master equation in the non-rotating wave approximation for the system. We then solve the master equation for a bipartite harmonic oscillator Hamiltonian with entangled initial state. We show that for strong damping...
1004.4515v2
2010-04-27
Radiation Damping in a Non-Abelian Strongly-Coupled Gauge Theory
We study a `dressed' or `composite' quark in strongly-coupled N=4 super-Yang-Mills (SYM), making use of the AdS/CFT correspondence. We show that the standard string dynamics nicely captures the physics of the quark and its surrounding quantum non-Abelian field configuration, making it possible to derive a relativistic ...
1004.4912v1
2010-05-21
Quantization of the Damped Harmonic Oscillator Revisited
We return to the description of the damped harmonic oscillator by means of a closed quantum theory with a general assessment of previous works, in particular the Bateman-Caldirola-Kanai model and a new model recently proposed by one of the authors. We show the local equivalence between the two models and argue that lat...
1005.4096v1
2010-06-09
Dispersion and damping of two-dimensional dust acoustic waves: Theory and Simulation
A two-dimensional generalized hydrodynamics (GH) model is developed to study the full spectrum of both longitudinal and transverse dust acoustic waves (DAW) in strongly coupled complex (dusty) plasmas, with memory-function-formalism being implemented to enforce high-frequency sum rules. Results are compared with earlie...
1006.1799v1
2010-07-01
Finite time extinction by nonlinear damping for Schrodinger equation
We consider the Schrodinger equation on a compact manifold, in the presence of a nonlinear damping term, which is homogeneous and sublinear. For initial data in the energy space, we construct a weak solution, defined for all positive time, which is shown to be unique. In the one-dimensional case, we show that it become...
1007.0077v2
2010-07-07
Spin drag Hall effect in a rotating Bose mixture
We show that in a rotating two-component Bose mixture, the spin drag between the two different spin species shows a Hall effect. This spin drag Hall effect can be observed experimentally by studying the out-of-phase dipole mode of the mixture. We determine the damping of this mode due to spin drag as a function of temp...
1007.1088v1
2010-08-30
Synthesis of electrical networks interconnecting PZT actuators to damp mechanical vibrations
This paper proves that it is possible to damp mechanical vibrations of some beam frames by means of piezoelectric actuators interconnected via passive networks. We create a kind of electromechanical wave guide where the electrical velocity group equals the mechanical one thus enabling an electromechanical energy transf...
1008.5112v1
2010-09-15
Anomalous High-Energy Spin Excitations in La2CuO4
Inelastic neutron scattering is used to investigate the collective magnetic excitations of the high-temperature superconductor parent antiferromagnet La2CuO4. We find that while the lower energy excitations are well described by spin-wave theory, including one- and two-magnon scattering processes, the high-energy spin ...
1009.2915v1
2010-10-05
Damping of dHvA oscillations and vortex-lattice disorder in the peak-effect region of strong type-II superconductors
The phenomenon of magnetic quantum oscillations in the superconducting state poses several questions that still defy satisfactory answers. A key controversial issue concerns the additional damping observed in the vortex state. Here, we show results of \mu SR, dHvA, and SQUID magnetization measurements on borocarbide su...
1010.0929v1
2010-10-21
Classical behavior of strongly correlated Fermi systems near a quantum critical point. Transport properties
The low-temperature kinetics of the strongly correlated electron liquid inhabiting a solid is analyzed. It is demonstrated that a softly damped branch of transverse zero sound emerges when several bands cross the Fermi surface simultaneously near a quantum critical point at which the density of states diverges. Suppres...
1010.4547v1
2010-10-26
Open Quantum Systems in Noninertial Frames
We study the effects of decoherence on the entanglement generated by Unruh effect in noninertial frames by using bit flip, phase damping and depolarizing channels. It is shown that decoherence strongly influences the initial state entanglement. The entanglement sudden death can happens irrespective of the acceleration ...
1010.5395v1
2010-11-17
Faint Resonantly Scattered Lyman Alpha Emission from the Absorption Troughs of Damped Lyman Alpha Systems at z ~ 3
We demonstrate that the Lyman alpha emission in the absorption troughs of a large sample of stacked damped Lyman alpha absorption systems (DLAS) presented by Rahmani et al (2010) is consistent with the spectral profiles and luminosities of a recently detected population of faint Lyman alpha emitters at z ~ 3. This resu...
1011.4061v1
2010-12-19
Quantum damping of Fermi-Pasta-Ulam revivals in ultracold Bose gases
We propose an experimental scheme for studying the Fermi-Pasta-Ulam (FPU) phenomenon in a quantum mechanical regime using ultracold atoms. Specifically, we suggest and analyze a setup of one-dimensional Bose gases confined into an optical lattice. The strength of quantum fluctuations is controlled by tuning the number ...
1012.4159v1
2010-12-21
Pullback attractors for a singularly nonautonomous plate equation
We consider the family of singularly nonautonomous plate equation with structural damping \[ u_{tt} + a(t,x)u_{t} + (- \Delta) u_{t} + (-\Delta)^{2} u + \lambda u = f(u), \] in a bounded domain $\Omega \subset \R^n$, with Navier boundary conditions. When the nonlinearity $f$ is dissipative we show that this problem is ...
1012.4749v1
2010-12-30
On rotational solutions for elliptically excited pendulum
The author considers the planar rotational motion of the mathematical pendulum with its pivot oscillating both vertically and horizontally, so the trajectory of the pivot is an ellipse close to a circle. The analysis is based on the exact rotational solutions in the case of circular pivot trajectory and zero gravity. T...
1101.0062v1
2011-03-10
Laser-like vibrational instability in rectifying molecular conductors
We study the damping of molecular vibrations due to electron-hole pair excitations in donor-acceptor(D-A) type molecular rectifiers. At finite voltage additional non-equilibrium electron-hole pair excitations involving both electrodes become possible, and contribute to the stimulated emission and absorption of phonons....
1103.1990v1
2011-03-11
Spin Transport in Polaronic and Superfluid Fermi Gases
We present measurements of spin transport in ultracold gases of fermionic lithium-6 in a mixture of two spin states at a Feshbach resonance. In particular, we study the spin dipole mode, where the two spin components are displaced from each other against a harmonic restoring force. We prepare a highly-imbalanced, or po...
1103.2337v1
2011-03-14
Tidal Evolution of a Secularly Interacting Planetary System
In a multi-planet system, a gradual change in one planet's semi-major axis will affect the eccentricities of all the planets, as angular momentum is distributed via secular interactions. If tidal dissipation in the planet is the cause of the change in semi-major axis, it also damps that planet's eccentricity, which in ...
1103.2794v1
2011-03-30
Damping in quantum love affairs
In a series of recent papers we have used an operatorial technique to describe stock markets and, in a different context, {\em love affairs} and their time evolutions. The strategy proposed so far does not allow any dumping effect. In this short note we show how, within the same framework, a strictly non periodic or qu...
1103.5907v1
2011-04-03
Spatially confined Bloch oscillations in semiconductor superlattices
In a semiconductor superlattice with long scattering times, damping of Bloch oscillations due to scattering is so small that convective nonlinearities may compensate it and Bloch oscillations persist even in the hydrodynamic regime. In this case, numerical solutions show that there are stable Bloch oscillations confine...
1104.0429v2
2011-04-06
Relativistic magnetic reconnection at X-type neutral points
Relativistic effects in the oscillatory damping of magnetic disturbances near two-dimensional X-points are investigated. By taking into account displacement current, we study new features of extremely magnetized systems, in which the Alfv\'en velocity is almost the speed of light. The frequencies of the least-damped mo...
1104.1003v1
2011-04-06
Observed damping of the slow magnetoacoustic mode
Spectroscopic and stereoscopic imaging observations of slow magnetoacoustic wave propagation within a coronal loop are investigated to determine the decay length scale of the slow magnetoacoustic mode in three dimensions and the density profile within the loop system. The slow wave is found to have an e-folding decay l...
1104.1100v1
2011-04-17
Stochastic Wave Equations with Nonlinear Damping and Source Terms
In this paper, we discuss an initial boundary value problem for the stochastic wave equation involving the nonlinear damping term $|u_t|^{q-2}u_t$ and a source term of the type $|u|^{p-2}u$. We firstly establish the local existence and uniqueness of solution by the Galerkin approximation method and show that the soluti...
1104.3279v2
2011-05-07
Cooperative scattering measurement of coherence in a spatially modulated Bose gas
Correlations of a Bose gas released from an optical lattice are measured using superradiant scattering. Conditions are chosen so that after initial incident light pumping at the Bragg angle for diffraction, due to matter wave amplification and mode competition, superradiant scattering into the Bragg diffracted mode is ...
1105.1425v1
2011-06-09
Hamiltonian of mean force for damped quantum systems
We consider a quantum system linearly coupled to a reservoir of harmonic oscillators. For finite coupling strengths, the stationary distribution of the damped system is not of the Gibbs form, in contrast to standard thermodynamics. With the help of the quantum Hamiltonian of mean force, we quantify this deviation exact...
1106.1775v1
2011-06-17
Current effect on magnetization oscillations in a ferromagnet - antiferromagnet junction
Spin-polarized current effect is studied on the static and dynamic magnetization of the antiferromagnet in a ferromagnet - antiferromagnet junction. The macrospin approximation is generalized to antiferromagnets. Canted antiferromagnetic configuration and resulting magnetic moment are induced by an external magnetic fi...
1106.3519v1
2011-06-23
Dissipation evidence for the quantum damped harmonic oscillator via pseudo-bosons
It is known that a self-adjoint, time-independent hamiltonian can be defined for the quantum damped harmonic oscillator. We show here that the two vacua naturally associated to this operator, when expressed in terms of pseudo-bosonic lowering and raising operators, appear to be non square-integrable. This fact is inter...
1106.4638v1
2011-07-15
Aspects of General Relativity: Pseudo-Finsler extensions, Quasi-normal frequencies and Multiplication of tensorial distributions
This thesis is based on three different projects, all of them are directly linked to the classical general theory of relativity, but they might have consequences for quantum gravity as well. The first chapter deals with pseudo-Finsler geometric extensions of the classical theory, these being ways of naturally represent...
1107.2978v1
2011-08-08
Synchrotron radiation damping, intrabeam scattering and beam-beam simulations for HE-LHC
The proposed High-Energy LHC project presents an unusual combination of strong synchrotron radiation (SR) damping and intrabeam scattering (IBS), which is not seen in present-day hadron colliders. The subject of investigation reported in this paper was the simulation of beam-beam effect for the HE-LHC parameters. Param...
1108.1644v1
2011-09-09
Delocalization of slowly damped eigenmodes on Anosov manifolds
We look at the properties of high frequency eigenmodes for the damped wave equation on a compact manifold with an Anosov geodesic flow. We study eigenmodes with spectral parameters which are asymptotically close enough to the real axis. We prove that such modes cannot be completely localized on subsets satisfying a con...
1109.1909v2
2011-10-18
Life times and chirality of spin-waves in antiferromagnetic and ferromagnetic FeRh: time depedent density functional theory perspective
The study of the spin excitations in antiferromagnetic (AFM) and ferromagnetic (FM) phases of FeRh is reported. We demonstrate that although the Fe atomic moments are well defined there is a number of important phenomena absent in the Heisenberg description: Landau damping of spin waves, large Rh moments induced by the...
1110.3913v1
2011-10-21
Environment-Assisted Error Correction of Single-Qubit Phase Damping
Open quantum system dynamics of random unitary type may in principle be fully undone. Closely following the scheme of environment-assisted error correction proposed by Gregoratti and Werner [M. Gregoratti and R. F. Werner, J. Mod. Opt. 50(6), 915-933 (2003)], we explicitly carry out all steps needed to invert a phase-d...
1110.4806v1
2011-11-01
Damping of tensor modes in inflation
We discuss the damping of tensor modes due to anisotropic stress in inflation. The effect is negligible in standard inflation and may be significantly large in inflation models that involve drastic production of free-streaming particles.
1111.0295v3
2011-11-04
Global uniform asymptotic stabilization and k-exponential trajectory tracking of underactuated surface ships with non-diagonal inertia/damping matrices
In this work, we investigate the state stabilization and trajectory tracking problems of underactuated surface ships with full state model of having non-diagonal inertia and damping matrices. By combining the novel state transformations, the direct Lyapunov approach, and the nonlinear time-varying tools, the stabilizat...
1111.1029v1
2011-11-08
The entropy of large black holes in loop quantum gravity: A combinatorics/analysis approach
The issue of a possible damping of the entropy periodicity for large black holes in Loop Quantum Gravity is highly debated. Using a combinatorics/analysis approach, we give strong arguments in favor of this damping, at least for prescriptions where the projection constraint is not fully implemented. This means that bla...
1111.1975v1
2011-11-15
Finite Size Effects of the Surface States in a Lattice Model of Topological Insulator
Energy gap and wave function in thin films of topological insulator is studied, based on tight--binding model. It is revealed that thickness dependence of the magnitude of energy gap is composed of damping and oscillation. The damped behavior originates from the presence of gapless surface Dirac cone in the infinite th...
1111.3528v2
2011-11-23
Pumping the eccentricity of exoplanets by tidal effect
Planets close to their host stars are believed to undergo significant tidal interactions, leading to a progressive damping of the orbital eccentricity. Here we show that, when the orbit of the planet is excited by an outer companion, tidal effects combined with gravitational interactions may give rise to a secular incr...
1111.5486v1
2011-11-30
Shear viscosity and damping of collective modes in a two-dimensional Fermi gas
We compute the shear viscosity of a two dimensional Fermi gas interacting via a short range potential with scattering length $a_{2d}$ in kinetic theory. We find that kinetic theory predicts that the shear viscosity to entropy density ratio of a strongly interacting two dimensional gas is comparable to that of the three...
1111.7242v2
2011-12-13
Drastically suppressing the error of ballistic readout of qubits
The thermal jitter of transmission of magnetic flux quanta in long Josephson junctions is studied. While for large-to-critical damping and small values of bias current the physically obvious dependence of the jitter versus length $\sigma\sim\sqrt{L}$ is confirmed, for small damping starting from the experimentally rele...
1112.2805v1