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47
2004-04-30
On violation of the Robinson's damping criterion and enhanced cooling of ion, electron and muon beams in storage rings
Limits of applicability of the Robinson's damping criterion and the problem of enhanced cooling of particle beams in storage rings beyond the criterion are discussed.
0404142v6
2004-12-28
Electron Bernstein waves in spherical tokamak plasmas with "magnetic wells"
In addition to traditional regimes with monotonously increasing magnetic field, regimes with "magnetic wells" also occur in spherical tokamaks (STs). The magnetic field profile inversion modifies significantly the whole picture of the wave propagation and damping. Since the magnetic wells may become quite common with f...
0412173v1
2005-08-16
Creep-Enhanced Low-Frequency Sensitivity of Seismometers
The frequency response of a seismometer is typically assumed to be the textbook case of a viscous damped, simple harmonic oscillator. Real mechanical oscillators are not ideal, and the damping at low frequencies, due to internal friction, is presently too poorly understood to describe from first principles. Even if the...
0508105v1
2006-06-22
Looking for a time independent Hamiltonian of a dynamical system
In this paper we introduce a method for finding a time independent Hamiltonian of a given dynamical system by canonoid transformation. We also find a condition that the system should satisfy to have an equivalent time independent formulation. We study the example of damped oscillator and give the new time independent H...
0606197v2
1996-02-27
Effects of Loss and Decoherence on a Simple Quantum Computer
We investigate the impact of loss (amplitude damping) and decoherence (phase damping) on the performance of a simple quantum computer which solves the one-bit Deutsch problem. The components of this machine are beamsplitters and nonlinear optical Kerr cells, but errors primarily originate from the latter. We develop mo...
9602018v1
1996-11-25
The Quantum state diffusion model and the driven damped nonlinear oscillator
We consider a driven damped anharmonic oscillator which classically leads to a bistable steady state and to hysteresis. The quantum counterpart for this system has an exact analytical solution in the steady state which does not display any bistability or hysteresis. We use quantum state diffusion theory to describe thi...
9611044v1
1997-12-02
Prevention of dissipation with two particles
An error prevention procedure based on two-particle encoding is proposed for protecting an arbitrary unknown quantum state from dissipation, such as phase damping and amplitude damping. The schemes, which exhibits manifestation of the quantum Zeno effect, is effective whether quantum bits are decohered independently or...
9712005v1
1998-02-23
Caldirola-Kanai Oscillator in Classical Formulation of Quantum Mechanics
The quadrature distribution for the quantum damped oscillator is introduced in the framework of the formulation of quantum mechanics based on the tomography scheme. The probability distribution for the coherent and Fock states of the damped oscillator is expressed explicitly in terms of Gaussian and Hermite polynomials...
9802057v1
1999-03-22
Decoherence - Fluctuation Relation and Measurement Noise
We discuss fluctuations in the measurement process and how these fluctuations are related to the dissipational parameter characterising quantum damping or decoherence. On the example of the measuring current of the variable-barrier or QPC problem we show there is an extra noise or fluctuation connected with the possibl...
9903072v1
1999-07-27
Nonclassical correlations in damped N-solitons
The quantum statistics of damped higher-order optical solitons are analyzed numerically, using cumulant-expansion techniques in Gaussian approximation. A detailed analysis of nonclassical properties in both the time and the frequency domain is given, with special emphasis on the role of absorption. Highly nonclassical ...
9907090v2
2001-01-08
Cavity-damping-induced transitions in a driven atom-cavity system
We investigate the fluorescence spectrum of a two-level atom in a cavity when the atom is driven by a classical field. We show that forbidden dipole transitions in the Jaynes-Cummings Ladder structure are induced in the presence of the cavity damping, which deteriorates the degree of otherwise perfect destructive inter...
0101036v1
2001-06-09
Squeezing enhancement by damping in a driven atom-cavity system
In a driven atom-cavity coupled system in which the two-level atom is driven by a classical field, the cavity mode which should be in a coherent state in the absence of its reservoir, can be squeezed by coupling to its reservoir. The squeezing effect is enhanced as the damping rate of the cavity is increased to some ex...
0106054v1
2001-08-01
Decoherence-induced wave packet splitting
We provide an intuitive interpretation of the optical Stern-Gerlach effect (OSGE) in the dressed-state point of view. We also analyze the effect of atomic damping in an experiment on the OSGE. We show that the atomic damping also causes the wave packet splitting, in a non-mechanical fashion, as opposed to the coherent ...
0108005v1
2001-08-11
A Canonical Approach to the Quantization of the Damped Harmonic Oscillator
We provide a new canonical approach for studying the quantum mechanical damped harmonic oscillator based on the doubling of degrees of freedom approach. Explicit expressions for Lagrangians of the elementary modes of the problem, characterising both forward and backward time propagations are given. A Hamiltonian anal...
0108055v2
2002-05-09
Implementation of quantum maps by programmable quantum processors
A quantum processor is a device with a data register and a program register. The input to the program register determines the operation, which is a completely positive linear map, that will be performed on the state in the data register. We develop a mathematical description for these devices, and apply it to several d...
0205050v1
2002-08-28
Damped Quantum Interference using Stochastic Calculus
It is shown how the phase-damping master equation, either in Markovian and nonMarkovian regimes, can be obtained as an averaged random unitary evolution. This, apart from offering a common mathematical setup for both regimes, enables us to solve this equation in a straightforward manner just by solving the Schrodinger ...
0208176v1
2002-10-31
Quantum Markov Channels for Qubits
We examine stochastic maps in the context of quantum optics. Making use of the master equation, the damping basis, and the Bloch picture we calculate a non-unital, completely positive, trace-preserving map with unequal damping eigenvalues. This results in what we call the squeezed vacuum channel. A geometrical picture ...
0211001v1
2003-01-17
Concurrence and foliations induced by some 1-qubit channels
We start with a short introduction to the roof concept. An elementary discussion of phase-damping channels shows the role of anti-linear operators in representing their concurrence. A general expression for some concurrences is derived. We apply it to 1-qubit channels of length two, getting induced foliations of the st...
0301088v1
2003-05-19
Statistical Effects in the Multistream Model for Quantum Plasmas
A statistical multistream description of quantum plasmas is formulated, using the Wigner-Poisson system as dynamical equations. A linear stability analysis of this system is carried out, and it is shown that a Landau-like damping of plane wave perturbations occurs due to the broadening of the background Wigner function...
0305102v1
2003-06-28
Misbelief and misunderstandings on the non--Markovian dynamics of a damped harmonic oscillator
We use the exact solution for the damped harmonic oscillator to discuss some relevant aspects of its open dynamics often mislead or misunderstood. We compare two different approximations both referred to as Rotating Wave Approximation. Using a specific example, we clarify some issues related to non--Markovian dynamics,...
0306193v3
2003-11-26
Effective damping in the Raman cooling of trapped ions
We present a method of treating the interaction of a single three-level ion with two laser beams. The idea is to apply a unitary transformation such that the exact transformed Hamiltonian has one of the three levels decoupled for all values of the detunings. When one takes into account damping, the evolution of the sys...
0311183v1
2004-06-20
Entanglement-assisted classical information capacity of the amplitude damping channel
In this paper, we calculate the entanglement-assisted classical information capacity of amplitude damping channel and compare it with the particular mutual information which is considered as the entanglement-assisted classical information capacity of this channel in Ref. 6. It is shown that the difference between them ...
0406140v1
2004-08-13
Decoherence versus Dynamical Casimir Effect
By means of two simple examples: phase and amplitude damping, the impact of decoherence on the dynamical Casimir effect is investigated. Even without dissipating energy (i.e., pure phase damping), the amount of created particles can be diminished significantly via the coupling to the environment (reservoir theory) indu...
0408087v2
2004-10-11
Quantizing the damped harmonic oscillator
We consider the Fermi quantization of the classical damped harmonic oscillator (dho). In past work on the subject, authors double the phase space of the dho in order to close the system at each moment in time. For an infinite-dimensional phase space, this method requires one to construct a representation of the CAR alg...
0410078v1
2004-11-18
Drastic effects of damping mechanisms on the third-order optical nonlinearity
We have investigated the optical response of superradiant atoms, which undergoes three different damping mechanisms: radiative dissipation ($\gamma_r$), dephasing ($\gamma_d$), and nonradiative dissipation ($\gamma_n$). Whereas the roles of $\gamma_d$ and $\gamma_n$ are equivalent in the linear susceptibility, the thir...
0411129v1
2005-01-19
Stabilizing an atom laser using spatially selective pumping and feedback
We perform a comprehensive study of stability of a pumped atom laser in the presence of pumping, damping and outcoupling. We also introduce a realistic feedback scheme to improve stability by extracting energy from the condensate and determine its effectiveness. We find that while the feedback scheme is highly efficien...
0501101v1
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
2006-09-19
Quantum master equations from classical Lagrangians with two stochastic forces
We show how a large family of master equations, describing quantum Brownian motion of a harmonic oscillator with translationally invariant damping, can be derived within a phenomenological approach, based on the assumption that an environment can be simulated by two classical stochastic forces. This family is determine...
0609144v3
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
2007-05-31
Stability of Solutions to Damped Equations with Negative Stiffness
This article concerns the stability of a model for mass-spring systems with positive damping and negative stiness. It is well known that when the coefficients are frozen in time the system is unstable. Here we find conditions on the variable cofficients to prove stability. In particular, we disprove the believe that if...
0705.4670v1
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
2007-10-24
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
2008-05-09
Spin dynamics in (III,Mn)V ferromagnetic semiconductors: the role of correlations
We address the role of correlations between spin and charge degrees of freedom on the dynamical properties of ferromagnetic systems governed by the magnetic exchange interaction between itinerant and localized spins. For this we introduce a general theory that treats quantum fluctuations beyond the Random Phase Approxi...
0805.1320v2
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
2008-08-09
Gilbert Damping in Conducting Ferromagnets I: Kohn-Sham Theory and Atomic-Scale Inhomogeneity
We derive an approximate expression for the Gilbert damping coefficient \alpha_G of itinerant electron ferromagnets which is based on their description in terms of spin-density-functional-theory (SDFT) and Kohn-Sham quasiparticle orbitals. We argue for an expression in which the coupling of magnetization fluctuations t...
0808.1373v1
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
2009-02-12
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
2009-09-11
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
2009-10-05
Construction of quasi-periodic response solutions in forced strongly dissipative systems
We consider a class of ordinary differential equations describing one-dimensional quasiperiodically forced systems in the presence of large damping. We give a fully constructive proof of the existence of response solutions, that is quasi-periodic solutions which have the same frequency vector as the forcing. This requi...
0910.0746v1
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
2009-11-12
A new perspective on supersymmetric inflation
We consider supersymmetric inflation with the hybrid-type potential. In the absence of the symmetry that forbids Hubble-induced mass terms, the inflaton mass will be as large as the Hubble scale during inflation. We consider gravitational decay of the trigger field as the least decay mode and find that the damping caus...
0911.2350v1
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
2010-01-16
Resonance Damping in Ferromagnets and Ferroelectrics
The phenomenological equations of motion for the relaxation of ordered phases of magnetized and polarized crystal phases can be developed in close analogy with one another. For the case of magnetized systems, the driving magnetic field intensity toward relaxation was developed by Gilbert. For the case of polarized syst...
1001.2845v1
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
2010-04-27
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
2010-09-09
The Damped String Problem Revisited
We revisit the damped string equation on a compact interval with a variety of boundary conditions and derive an infinite sequence of trace formulas associated with it, employing methods familiar from supersymmetric quantum mechanics. We also derive completeness and Riesz basis results (with parentheses) for the associa...
1009.1858v1
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