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2008-06-12
Towards the description of anisotropic plasma at strong coupling
We initiate a study of anisotropic plasma at strong coupling using the AdS/CFT correspondence. We construct an exact dual geometry which represents a static uniform but anisotropic system and find, that although it is singular, it allows for a notion of `incoming' boundary conditions. We study small fluctuations around...
0806.2141v2
2008-06-19
Enhancement of sudden death of entanglement for driven qubits
We study the recently discovered phenomena of sudden death of entanglement for a system of two qubits, each of them independently longitudinally damped by a reservoir and subjected to a continuous driving. We show that driving produces, in the interaction picture, an effective bath that has elements amounting to variou...
0806.3186v1
2008-06-19
Negative dimensional approach to evaluating real integrals
In solving the differential equation for a non damped harmonic oscillator one meets, after subjecting the equation to a Fourier transformation, an integration in the complex $\omega$ plane. In most cases such an integral is evaluated by calculating residues together with some physical input such as the principle of cau...
0806.3216v1
2008-06-20
Rabi model beyond the rotating wave approximation: generation of photons from vacuum through decoherence
We study numerically the dynamics of the Rabi Hamiltonian, describing the interaction of a single cavity mode and a two-level atom without the rotating wave approximation, subjected to damping and dephasing reservoirs included via usual Lindblad superoperators in the master equation. We show that the combination of the...
0806.3475v1
2008-06-24
A Gear-like Predictor-Corrector method for Brownian Dynamics Simulation
We introduce a Predictor-Corrector type method suitable for performing many-particle Brownian Dynamics simulations. Since the method goes over to the Gear's method for Molecular Dynamics simulation in the limit of vanishing friction, we refer to it as a Gear-like algorithm. The algorithm has been tested on a one-dimens...
0806.3912v2
2008-06-25
Modulated Inflation (@SUSY08)
We consider cosmological perturbations caused by modulated inflaton velocity. During inflation, the inflaton motion is damped and the velocity is determined by the parameters such as couplings or masses that may depend on light fields(moduli). The number of e-foldings is different in different patches if there are spat...
0806.4065v1
2008-06-30
Superfluidity near phase separation in Bose-Fermi mixtures
We study the transition to fermion pair superfluidity in a mixture of interacting bosonic and fermionic atoms. The fermion interaction induced by the bosons and the dynamical screening of the condensate phonons due to fermions are included using the nonperturbative Hamiltonian flow equations. We determine the bosonic s...
0807.0002v2
2008-07-10
Multiplicative Noise Induces Zero Critical Frequency
Stochastic Bloch equations which model the fluorescence of two level molecules and atoms, NMR experiments and Josephson junctions are investigated to illustrate the profound effect of multiplicative noise on the critical frequency of a dynamical system. Using exact solutions and the cumulant expansion we find two main ...
0807.1585v1
2008-07-16
Decay of a metastable state activated by non-Gaussian noise: A critical review of the generalized Kramers problem
We review the problem of the noise activated escape from a metastable state in the presence of non-Gaussian noise, and present connections between various theoretical approaches. We also respond to criticism of our work by Tom\'a\v{s} Novotn\'y [arXiv:0807.0387] concerning the weak damping limit. The discrepancy betwee...
0807.2675v1
2008-07-18
Current-induced dynamics of spiral magnet
We study the dynamics of the spiral magnet under the charge current by solving the Landau-Lifshitz-Gilbert equation numerically. In the steady state, the current ${\vec j}$ induces (i) the parallel shift of the spiral pattern with velocity $v=(\beta/\alpha)j$ ($\alpha$, $\beta$: the Gilbert damping coefficients), (ii) ...
0807.2901v1
2008-08-04
Short Pulse Dynamics in Strongly Nonlinear Dissipative Granular Chains
We study the energy decay properties of a pulse propagating in a strongly nonlinear granular chain with damping proportional to the relative velocity of the grains. We observe a wave disturbance that at low viscosities consists of two parts exhibiting two entirely different time scales of dissipation. One part is an at...
0808.0527v1
2008-08-11
Persistence of zero modes in a gauged Dirac model for bilayer graphene
A recently constructed model for low lying excitations in bilayer graphene exhibits mid-gap, zero energy modes in its Dirac-like spectrum, when a scalar order parameter takes a vortex profile. We show that these modes persist when the dynamics is extended by a gauge field interaction, which also renders finite the vort...
0808.1562v1
2008-08-14
Planar Heterostructure Graphene -- Narrow-Gap Semiconductor -- Graphene
We investigate a planar heterostructure composed of two graphene films separated by a narrow-gap semiconductor ribbon. We show that there is no the Klein paradox when the Dirac points of the Brillouin zone of graphene are in a band gap of a narrow-gap semiconductor. There is the energy range depending on an angle of in...
0808.1981v2
2008-08-15
Asymptotic behavior of the mean square displacement of the Brownian parametric oscillator near the singular point
A parametric oscillator with damping driven by white noise is studied. The mean square displacement (MSD) in the long-time limit is derived analytically for the case that the static force vanishes, which was not treated in the past work \cite{tashiro07}. The formula is asymptotic but is applicable to a general periodic...
0808.2207v3
2008-08-29
Kramers Theory for Conformational Transitions of Macromolecules
We consider the application of Kramers theory to the microscopic calculation of rates of conformational transitions of macromolecules. The main difficulty in such an approach is to locate the transition state in a huge configuration space. We present a method which identifies the transition state along the most probabl...
0809.0027v1
2008-09-19
Predicting spin of compact objects from their QPOs: A global QPO model
We establish a unified model to explain Quasi-Periodic-Oscillation (QPO) observed from black hole and neutron star systems globally. This is based on the accreting systems thought to be damped harmonic oscillators with higher order nonlinearity. The model explains multiple properties parallelly independent of the natur...
0809.3336v1
2008-09-21
Stochastic Resonance in the Fermi-Pasta-Ulam Chain
We consider a damped $\beta$-Fermi-Pasta-Ulam chain, driven at one boundary subjected to stochastic noise. It is shown that, for a fixed driving amplitude and frequency, increasing the noise intensity, the system's energy resonantly responds to the modulating frequency of the forcing signal. Multiple peaks appear in th...
0809.3604v1
2008-09-23
Application of the Lifshitz theory to poor conductors
The Lifshitz formula for the dispersive forces is generalized to the materials, which cannot be described with the local dielectric response. Principal nonlocality of poor conductors is related with the finite screening length of the penetrating field and the collisional relaxation; at low temperatures the role of coll...
0809.3901v1
2008-09-26
On a possible connection between Chandler wobble and dark matter
Chandler wobble excitation and damping, one of the open problems in geophysics, is treated as a consequence in part of the interaction between Earth and a hypothetical oblate ellipsoid made of dark matter. The physical and geometrical parameters of such an ellipsoid and the interacting torque strength is calculated in ...
0809.4506v3
2008-09-26
The effects of twisted magnetic field on coronal loops oscillations and dissipation
The standing MHD modes in a zero-$\beta$ cylindrical magnetic flux tube modelled as a straight core surrounded by a magnetically twisted annulus, both embedded in a straight ambient external field is considered. The dispersion relation for the fast MHD waves is derived and solved numerically to obtain the frequencies o...
0809.4611v1
2008-10-01
Estimating Speed and Damping in the Stochastic Wave Equation
A parameter estimation problem is considered for a one-dimensional stochastic wave equation driven by additive space-time Gaussian white noise. The estimator is of spectral type and utilizes a finite number of the spatial Fourier coefficients of the solution. The asymptotic properties of the estimator are studied as ...
0810.0046v1
2008-10-11
Asymptotic Behavior of Stochastic Wave Equations with Critical Exponents on R^3
The existence of a random attractor in H^1(R^3) \times L^2(R^3) is proved for the damped semilinear stochastic wave equation defined on the entire space R^3. The nonlinearity is allowed to have a cubic growth rate which is referred to as the critical exponent. The uniform pullback estimates on the tails of solutions fo...
0810.1988v1
2008-10-16
Liquid behavior of hot QGP in the finite temperature field theory
In this paper, we compare the dispersion relations of hard thermal loop and complete one loop. It is shown that in the dynamical screening regime, the completely one-loop calculation presents a prominent threshold frequency, below which no pure imaginary mode survives. This phenomenon is responsible for the oscillatory...
0810.2841v1
2008-10-22
Quantum Brownian motion under rapid periodic forcing
We study the steady state behaviour of a confined quantum Brownian particle subjected to a space-dependent, rapidly oscillating time-periodic force. To leading order in the period of driving, the result of the oscillating force is an effective static potential which has a quantum dissipative contribution, $V_{QD}$, whi...
0810.4050v2
2008-10-25
The domain wall spin torque-meter
We report the direct measurement of the non-adiabatic component of the spin-torque in domain walls. Our method is independent of both the pinning of the domain wall in the wire as well as of the Gilbert damping parameter. We demonstrate that the ratio between the non-adiabatic and the adiabatic components can be as hig...
0810.4633v1
2008-10-26
Static potentials for quarkonia at finite temperatures
We review non-perturbative static potentials commonly used in potential models for quarkonia at finite T. Potentials derived from Polyakov loop correlators are shown to be inappropriate for this purpose. The q\bar{q} free energy is physical but has the wrong spatial decay and perturbative limit. The so-called singlet f...
0810.4685v1
2008-10-30
Weakly Turbulent MHD Waves in Compressible Low-Beta Plasmas
In this Letter, weak turbulence theory is used to investigate interactions among Alfven waves and fast and slow magnetosonic waves in collisionless low-beta plasmas. The wave kinetic equations are derived from the equations of magnetohydrodynamics, and extra terms are then added to model collisionless damping. These eq...
0810.5360v1
2008-11-04
Amplitude-Phase Coupling in a Spin-Torque Nano-Oscillator
The spin-torque nano-oscillator in the presence of thermal fluctuation is described by the normal form of the Hopf bifurcation with an additive white noise. By the application of the reduction method, the amplitude-phase coupling factor, which has a significant effect on the power spectrum of the spin-torque nano-oscil...
0811.0425v1
2008-11-07
Stability of drift waves in a field reversed configuration
The drift waves in field-reversed configurations without a toroidal magnetic field, therefore no shear, play an important role in plasma transport. The short connection length of the poloidal field in these systems leads to significant stabilization by influencing the wave particle resonance. The field reversed configu...
0811.1201v1
2008-11-11
Reduction and possible elimination of coating thermal noise using a rigidly controlled cavity with a QND technique
Thermal noise of a mirror is one of the most important issues in high precision measurements such as gravitational-wave detection or cold damping experiments. It has been pointed out that thermal noise of a mirror with multi-layer coatings can be reduced by mechanical separation of the layers. In this paper, we introdu...
0811.1780v1
2008-11-17
PGPE theory of finite temperature collective modes for a trapped Bose gas
We develop formalism based on the projected Gross Pitaevskii equation to simulate the finite temperature collective mode experiments of Jin et al. [PRL 78, 764 (1997)]. We examine the $m=0$ and $m=2$ quadrupolar modes on the temperature range $0.51T_c-0.83T_c$ and calculate the frequencies of, and phase between, the co...
0811.2635v1
2008-11-19
Excitation of spin waves on a cylindrical semiconductor heterostructure with Rashba spin-orbit interaction
Elementary excitations in a paramagnetic semiconductor quantum well confined to a cylindrical surface are theoretically studied on the basis of coupled spin-charge drift-diffusion equations. The electric-field-mediated eigenmodes are optically excited by an oscillating interference pattern, which induces a current in t...
0811.3070v1
2008-11-28
Effect of Nonlocal Spin-Transfer Torque on Current-Induced Magnetization Dynamics
Using the self-consistent model, we present nonlocal spin-transfer effects caused by the feedback between inhomogeneous magnetization and spin-transfer torque on the current-induced magnetization dynamics in nanomagnets. The nonlocal effects can substantially improve the coherence time of precession in nanomagnets and ...
0811.4649v1
2008-11-29
Plane Gravitational Radiation from Neutrinos Source with Kalb-Ramond Coupling
In this work, we propose a model based on a non-minimal coupling of neutrinos to a Kalb-Ramond field. The latter is taken as a possible source for gravitational radiation. As an immediate illustration of this system, we have studied the case where gravitational (plane) wave solutions behave as damped harmonic oscillato...
0812.0078v1
2008-12-03
Observation of ferromagnetic resonance in strontium ruthenate (SrRuO3)
We report the observation of ferromagnetic resonance (FMR) in SrRuO3 using the time-resolved magneto-optical Kerr effect. The FMR oscillations in the time-domain appear in response to a sudden, optically induced change in the direction of easy-axis anistropy. The high FMR frequency, 250 GHz, and large Gilbert damping p...
0812.0832v1
2008-12-04
On parton distributions in a photon gas
In some cases it may be useful to know parton distributions in a photon gas. This may be relevant, e.g., for the analysis of interactions of high energy cosmic ray particles with the cosmic microwave background radiation. The latter can be considered as a gas of photons with an almost perfect blackbody spectrum. An app...
0812.0937v2
2008-12-09
Parameter estimation with cluster states
We propose a scheme for parameter estimation with cluster states. We find that phase estimation with cluster states under a many-body Hamiltonian and separable measurements leads to a precision at the Heisenberg limit. As noise models we study the dephasing, depolarizing, and pure damping channels. Decoherence reduces ...
0812.1747v3
2008-12-19
Head-Tail Modes for Strong Space Charge
The head-tail modes are described for the space charge tune shift significantly exceeding the synchrotron tune. A general equation for the modes is derived. The spatial shapes of the modes, their frequencies, and coherent growth rates are explored. The Landau damping rates are also found. The suppression of the transve...
0812.3914v3
2008-12-30
Bulk viscosity of strange matter and r-modes in neutron stars
We discuss bulk viscosity due to non-leptonic processes involving hyperons and Bose-Einstein condensate of negatively charged kaons in neutron stars. It is noted that the hyperon bulk viscosity coefficient is a few order of magnitude larger than that of the case with the condensate. Further it is found that the hyperon...
0812.5021v1
2009-01-06
Ionization in damped time-harmonic fields
We study the asymptotic behavior of the wave function in a simple one dimensional model of ionization by pulses, in which the time-dependent potential is of the form $V(x,t)=-2\delta(x)(1-e^{-\lambda t} \cos\omega t)$, where $\delta$ is the Dirac distribution. We find the ionization probability in the limit $t\to\infty...
0901.0724v1
2009-01-09
Stability of the Second Order Delay Differential Equations with a Damping Term
For the delay differential equations $$ \ddot{x}(t) +a(t)\dot{x}(g(t))+b(t)x(h(t))=0, g(t)\leq t, h(t)\leq t, $$ and $$ \ddot{x}(t) +a(t)\dot{x}(t)+b(t)x(t)+a_1(t)\dot{x}(g(t))+b_1(t)x(h(t))=0 $$ explicit exponential stability conditions are obtained.
0901.1277v1
2009-01-20
Multiple regimes of diffusion
We consider the diffusion of independent particles experiencing random accelerations by a space- and time-dependent force as well as viscous damping. This model can exhibit several asymptotic behaviours, depending upon the limiting cases which are considered, some of which have been discussed in earlier work. Here we e...
0901.3077v1
2009-01-22
Magnetic Field Induced Superconductivity in Out-of-Equilibrium Nanowires
Four-terminal resistance measurements have been carried out on Zn nanowires formed using electron-beam lithography. When driven resistive by current, these wires re-enter the superconducting state upon application of small magnetic fields. The data are qualitatively different from those of previous experiments on super...
0901.3519v1
2009-01-23
Wave propagation through soils in centrifuge testing
Wave propagation phenomena in soils can be experimentally simulated using centrifuge scale models. An original excitation device (drop-ball arrangement) is proposed to generate short wave trains. Wave reflections on model boundaries are taken into account and removed by homomorphic filtering. Propagation is investigate...
0901.3718v1
2009-01-27
Excitation of standing kink oscillations in coronal loops
In this work we review the efforts that have been done to study the excitation of the standing fast kink body mode in coronal loops. We mainly focus on the time-dependent problem, which is appropriate to describe flare or CME induced kink oscillations. The analytical and numerical studies in slab and cylindrical loop g...
0901.4233v1
2009-02-09
Seismic Crystals And Earthquake Shield Application
We theoretically demonstrate that earthquake shield made of seismic crystal can damp down surface waves, which are the most destructive type for constructions. In the paper, seismic crystal is introduced in aspect of band gaps (Stop band) and some design concepts for earthquake and tsunami shielding were discussed in t...
0902.1429v4
2009-02-11
Quantum fluctuation theorems in the strong damping limit
We consider a driven quantum particle in the strong friction regime described by the quantum Smoluchowski equation. We derive Crooks and Jarzynski type relations for the reduced quantum system by properly generalizing the entropy production to take into account the non-Gibbsian character of the equilibrium distribution...
0902.1858v2
2009-02-13
Continuous decoupling and freeze-out
The decoupling and freeze-out of energetic nuclear collisions is analysed in terms of transparent semi-classical decoupling formulae. They provide a smooth transition and generalise frequently employed instantaneous freeze-out procedures. Simple relations between the damping width and the duration of the decoupling pro...
0902.2373v1
2009-02-22
Noise and dissipation in magnetoelectronic nanostructures
We study the coupled current and magnetization noise in magnetic nanostructures by magnetoelectronic circuit theory. Spin current fluctuations, which depend on the magnetic configuration, are found to be an important source of magnetization noise and damping in thinly layered systems. The enhanced magnetization fluctua...
0902.3779v1
2009-02-26
Formation of Cooper pairs in quantum oscillations of electrons in plasma
We study low energy quantum oscillations of electron gas in plasma. It is shown that two electrons participating in these oscillations acquire additional negative energy when they interact by means of a virtual plasmon. The additional energy leads to the formation a Cooper pair and possible existence of the superconduc...
0902.4596v1
2009-03-02
Gravitational Wave Sources May Be "Further" Than We Think
It has been argued that the energy content in time varying spacetimes can be obtained by using the approximate Lie symmetries of the geodesics equations in that spacetime. When applied to cylindrical gravitational waves, it gives a self-damping of the waves. According to this proposal the energy of the waves go to zero...
0903.0252v3
2009-03-07
Impurity effects in multiferroic compounds
We investigate the effect of impurities in multiferroic materials using an equation of motion approach for the spin dynamics of the host multiferroic compound. We model the impurities as a two-level system and focus on the regime where the impurity spins relax slowly. When the impurity strength is weak the host spins o...
0903.1319v1
2009-03-12
Quantum Noise Interference and Back-action Cooling in Cavity Nanomechanics
We present a theoretical analysis of a novel cavity electromechanical system where a mechanical resonator directly modulates the damping rate kappa of a driven electromagnetic cavity. We show that via a destructive interference of quantum noise, the driven cavity can effectively act like a zero-temperature bath irrespe...
0903.2242v2
2009-03-19
Comment on "Non-monotonicity in the Quantum-Classical Transition: Chaos Induced by Quantum Effects"
In a recent Letter [PRL 101, 074101 (2008)], Kapulkin and Pattanayak presented evidence that a quantum Duffing oscillator, sufficiently damped so that it is not classically chaotic, becomes chaotic in the transition region between quantum and classical motion. If true, this would be a striking result. However, Kapulkin...
0903.3417v1
2009-03-24
The Jeans Mechanism and Bulk-Viscosity Effects
In this paper we study the gravitational instability in presence of viscosity. In particular, the standard Jeans Mechanism is analyzed taking into account bulk-viscosity effects in the first-order Newtonian dynamics. We show how the perturbation evolution is damped by dissipative processes and the top-down fragmentatio...
0903.4122v3
2009-04-10
Vortex oscillations induced by a spin-polarized current in a magnetic nanopillar: Evidence for a failure of the Thiele approach
We investigate the vortex excitations induced by a spin-polarized current in a magnetic nanopillar by means of micromagnetic simulations and analytical calculations. Damped motion, stationary vortex rotation and the switching of the vortex core are successively observed for increasing values of the current. We demonstr...
0904.1751v1
2009-04-14
Quasiparticle tunneling: P(E) theory
A calculation of the energy decay rate of a Josephson qubit from non-equilibrium quasiparticles is made using the environmental P(E) theory. For a large-capacitance qubit, we extend the theory to include the tunneling of quasiparticles, which has an electron- and hole-like charge components.
0904.2035v2
2009-04-16
Experimental synchronization of circuit oscillations induced by common telegraph noise
Experimental realization and quantitative investigation of common-noise-induced synchronization of limit-cycle oscillations subject to random telegraph signals are performed using an electronic oscillator circuit. Based on our previous formulation [K. Nagai et al., Phys. Rev. E 71, 036217 (2005)], dynamics of the circu...
0904.2439v1
2009-04-17
ITM Probe: analyzing information flow in protein networks
Summary: Founded upon diffusion with damping, ITM Probe is an application for modeling information flow in protein interaction networks without prior restriction to the sub-network of interest. Given a context consisting of desired origins and destinations of information, ITM Probe returns the set of most relevant prot...
0904.2770v1
2009-04-28
Dielectric function and plasmons in graphene
The electromagnetic response of graphene, expressed by the dielectric function, and the spectrum of collective excitations are studied as a function of wave vector and frequency. Our calculation is based on the full band structure, calculated within the tight-binding approximation. As a result, we find plasmons whose d...
0904.4378v1
2009-05-01
Asymptotic behavior of second-order dissipative evolution equations combining potential with non-potential effects
We study the asymptotic convergence properties, as the time variable goes to infinity, of trajectories of second-order dissipative evolution equations combining potential with non-potential effects. We exhibit a sharp condition, involving the damping parameter and the cocoercive coefficient of the non-potential operato...
0905.0092v1
2009-05-04
Homopolar oscillating-disc dynamo driven by parametric resonance
We use a simple model of Bullard-type disc dynamo, in which the disc rotation rate is subject to harmonic oscillations, to analyze the generation of magnetic field by the parametric resonance mechanism. The problem is governed by a damped Mathieu equation. The Floquet exponents, which define the magnetic field growth r...
0905.0400v1
2009-05-06
Quantum adaptation of noisy channels
Probabilistic quantum filtering is proposed to properly adapt sequential independent quantum channels in order to stop sudden death of entanglement. In the adaptation, the quantum filtering does not distill or purify more entanglement, it rather properly prepares entangled state to the subsequent quantum channel. For e...
0905.0862v1
2009-05-13
Observation of spin-wave propagation in permalloy microstripes
We report on the propagation of spin waves in permalloy microstripes. By means of scanning Kerr microscopy combined with continuous microwave excitation, we detect the time evolution of spin-wave interference patterns in an external magnetic field. Assuming transverse spin-wave quantization we can directly measure the ...
0905.2172v1
2009-05-18
Global well-posedness for cubic NLS with nonlinear damping
We study the Cauchy problem for the cubic nonlinear Schroedinger equation, perturbed by (higher order) dissipative nonlinearities. We prove global in-time existence of solutions for general initial data in the energy space. In particular we treat the energy-critical case of a quintic dissipation in three space dimensio...
0905.3000v4
2009-05-20
Pumping properties of the hybrid single-electron transistor in dissipative environment
Pumping characteristics were studied of the hybrid normal-metal/superconductor single-electron transistor embedded in a high-ohmic environment. Two 3 micrometer-long microstrip resistors of CrOx with a sum resistance R=80kOhm were placed adjacent to this hybrid device. Substantial improvement of pumping and reduction o...
0905.3402v1
2009-05-27
Stability of scalar radiative shock profiles
This work establishes nonlinear orbital asymptotic stability of scalar radiative shock profiles, namely, traveling wave solutions to the simplified model system of radiating gas \cite{Hm}, consisting of a scalar conservation law coupled with an elliptic equation for the radiation flux. The method is based on the deriva...
0905.4448v1
2009-05-28
Wigner function non-classicality as indicator of quantum chaos
We propose a Wigner function based parameter that can be used as an indicator of quantum chaos. This parameter is defined as "entropy" from the time-dependence of "non-classicallity" proposed in \cite{KZ04}. We perform our considerations for the system of damped nonlinear (Kerr-like) oscillator excited by a series of u...
0905.4638v2
2009-05-30
Solution of linearized Fokker - Planck equation for incompressible fluid
In this work we construct algebraic equation for elements of spectrum of linearized Fokker - Planck differential operator for incompressible fluid. We calculate roots of this equation using simple numeric method. For all these roots real part is positive, that is corresponding solutions are damping. Eigenfunctions of l...
0906.0070v1
2009-06-09
Homogenization of accelerated Frenkel-Kontorova models with $n$ types of particles
We consider systems of ODEs that describe the dynamics of particles. Each particle satisfies a Newton law (including the acceleration term) where the force is created by the interactions with the other particles and with a periodic potential. The presence of a damping term allows the system to be monotone. Our study ta...
0906.1722v2
2009-06-12
Poor qubits make for rich physics: noise-induced quantum Zeno effects and noise-induced Berry phases
We briefly review three ways that environmental noise can slow-down (or speed-up) quantum transitions; (i) Lamb shifts, (ii) over-damping and (iii) orthogonality catastrophe. We compare them with the quantum Zeno effect induced by observing the system. These effects are relevant to poor qubits (those strongly coupled t...
0906.2368v1
2009-06-19
Investigation of an alternate means of wakefield suppression in the main linacs of CLIC
We report on suppression of long-range wakefields in CLIC accelerating structures. Strong detuning and moderate damping is employed. In these initial design studies we focus on the CLIC_G structure and enforce a moderate Q of 300 and 500. We maintain a dipole bandwidth of approximately 1 GHz as specified from breakdown...
0906.3591v1
2009-06-22
Thermal breakage of a discrete one-dimensional string
We study the thermal breakage of a discrete one-dimensional string, with open and fixed ends, in the heavily damped regime. Basing our analysis on the multidimensional Kramers escape theory, we are able to make analytical predictions on the mean breakage rate, and on the breakage propensity with respect to the breakage...
0906.3754v3
2009-06-23
Parameter Estimation in Diagonalizable Stochastic Hyperbolic Equations
A parameter estimation problem is considered for a linear stochastic hyperbolic equation driven by additive space-time Gaussian white noise. The damping/amplification operator is allowed to be unbounded. The estimator is of spectral type and utilizes a finite number of the spatial Fourier coefficients of the solution...
0906.4353v1
2009-06-29
Semiclassical Wigner distribution for two-mode entangled state generated by an optical parametric oscillator
We derive the steady state solution of the Fokker-Planck equation that describes the dynamics of the nondegenerate optical parametric oscillator in the truncated Wigner representation of the density operator. The adiabatic limit of strong pump damping is assumed. This phase space image provides a clear view of the intr...
0906.5316v1
2009-07-02
The Jeans Instability in Presence of Viscous Effects
An analysis of the gravitational instability in presence of dissipative effects is addressed. In particular, the standard Jeans Mechanism and the generalization in treating the Universe expansion are both analyzed when bulk viscosity affects the first-order Newtonian dynamics. As results, the perturbation evolution is ...
0907.0434v2
2009-07-05
Stabilities for Euler-Poisson Equations in Some Special Dimensions
We study the stabilities and classical solutions of Euler-Poisson equations of describing the evolution of the gaseous star in astrophysics. In fact, we extend the study the stabilities of Euler-Poisson equations with or without frictional damping term to some special dimensional spaces. Besides, by using the second in...
0907.0873v1
2009-07-10
Fractional Equations of Curie-von Schweidler and Gauss Laws
The dielectric susceptibility of most materials follows a fractional power-law frequency dependence that is called the "universal" response. We prove that in the time domain this dependence gives differential equations with derivatives and integrals of noninteger order. We obtain equations that describe "universal" Cur...
0907.1837v1
2009-07-13
Universal Electromagnetic Waves in Dielectric
The dielectric susceptibility of a wide class of dielectric materials follows, over extended frequency ranges, a fractional power-law frequency dependence that is called the "universal" response. The electromagnetic fields in such dielectric media are described by fractional differential equations with time derivatives...
0907.2163v1
2009-07-21
Wobbling kinks in $φ^4$ theory
We present a uniform asymptotic expansion of the wobbling kink to any order in the amplitude of the wobbling mode. The long-range behaviour of the radiation is described by matching the asymptotic expansions in the far field and near the core of the kink. The complex amplitude of the wobbling mode is shown to obey a si...
0907.3611v1
2009-07-31
New Correlated Model of Colossal Magnetoresistive Manganese Oxides
A new minimal model is constructed for the doped manganese oxides which exhibit colossal magnetoresistance (CMR), involving broad spin-majority conduction band as well as nearly localised spin-minority electron states. A simple mean field analysis yields a temperature-dependent hybridised band structure with suppressed...
0907.5512v3
2009-08-11
Effect of bath temperature on the quantum decoherence
The dynamics of a qubit in two different environments are investigated theoretically. The first environment is a two level system coupled to a bosonic bath. And the second one is a damped harmonic oscillator. Based on a unitary transformation, we find that the decoherence of the qubit can be reduced with increasing tem...
0908.1454v2
2009-08-15
Numerical study on diverging probability density function of flat-top solitons in an extended Korteweg-de Vries equation
We consider an extended Korteweg-de Vries (eKdV) equation, the usual Korteweg-de Vries equation with inclusion of an additional cubic nonlinearity. We investigate the statistical behaviour of flat-top solitary waves described by an eKdV equation in the presence of weak dissipative disorder in the linear growth/damping ...
0908.2152v1
2009-09-01
Polariton-mediated Raman scattering in microcavities: A Green's function approach
We present calculations of the intensity of polariton-mediated inelastic light scattering in semiconductor microcavities within a Green's function framework. In addition to reproducing the strong coupling of light and matter, this method also enables the inclusion of damping mechanisms in a consistent way. Our results ...
0909.0296v1
2009-09-02
Numerical modelling of convection-diffusion-reaction problems with free boundary in 1D
We discuss a numerical method for convection-diffusion-reaction problems with a free boundary in 1D. The method is based on the numerical modelling of the interface evolution, the transformation to a fixed domain problem and the approximation by an ODE system. The interface evolution is modelled by means of the local s...
0909.0363v1
2009-09-02
Quantum Zeno and anti-Zeno effect in atom-atom entanglement induced by non-Markovian environment
The dynamic behavior of the entanglement for two two-level atoms coupled to a common lossy cavity is studied. We find that the speed of disentanglement is a decreasing (increasing) function of the damping rate of the cavity for on/near (far-off) resonant couplings. The quantitative explanations for these phenomena are ...
0909.0375v1
2009-10-07
Cavity cooling of an optically trapped nanoparticle
We study the cooling of a dielectric nanoscale particle trapped in an optical cavity. We derive the frictional force for motion in the cavity field, and show that the cooling rate is proportional to the square of oscillation amplitude and frequency. Both the radial and axial centre-of-mass motion of the trapped particl...
0910.1221v1
2009-10-19
Valley symmetry breaking in bilayer graphene: a test to the minimal model
Physical properties reflecting valley asymmetry of Landau levels in a biased bilayer graphene under magnetic field are discussed. Within the $4-$band continuum model with Hartree-corrected self-consistent gap and finite damping factor we predict the appearance of anomalous steps in quantized Hall conductivity due to th...
0910.3469v1
2009-10-27
Quasinormal modes of Dirac field perturbation in Reissner-Nordström black hole surrounded by quintessence
The dirac quasinormal modes of the Reissner-Nordstr\"om black hole surrounded by quintessence are investigated using the third WKB approximation. We find that the magnitude of the imaginary part of the quasinormal mode frequencies increases firstly and then decreases as the charge $Q$ increases, but it decreases as the...
0910.5128v2
2009-10-28
DNA Breathing Dynamics in the Presence of a Terahertz Field
We consider the influence of a terahertz field on the breathing dynamics of double-stranded DNA. We model the spontaneous formation of spatially localized openings of a damped and driven DNA chain, and find that linear instabilities lead to dynamic dimerization, while true local strand separations require a threshold a...
0910.5294v1
2009-10-28
Interacting spin waves in the ferromagnetic Kondo lattice model
We present an new approach for the ferromagnetic, three-dimensional, translational-symmetric Kondo lattice model which allows us to derive both magnon energies and linewidths (lifetimes) and to study the properties of the ferromagnetic phase at finite temperatures. Both "anomalous softening" and "anomalous damping" are...
0910.5478v2
2009-11-23
Constraints on neutrino -- dark matter interactions from cosmic microwave background and large scale structure data
We update a previous investigation of cosmological effects of a non-standard interaction between neutrinos and dark matter. Parameterizing the elastic-scattering cross section between the two species as a function of the temperature of the universe, the resulting neutrino-dark matter fluid has a non-zero pressure, whic...
0911.4411v1
2009-11-25
Phase-Mixing and Dissipation of Standing Shear Alfven waves
We study the phase mixing and dissipation of a packet of standing shear Alfv\'en waves localized in a region with non-uniform Alfv\'en background velocity. We investigate the validity of the exponential damping law in time, $\exp(-At^3)$, presented by Heyvaerts & Priest (1983) for different ranges of Lundquist, $S$, an...
0911.4901v1
2009-12-10
On Schroedinger Equation with Time-Dependent Quadratic Hamiltonian in $R^d$
We study solutions to the Cauchy problem for the linear and nonlinear Schroedinger equation with a quadratic Hamiltonian depending on time. For the linear case the evolution operator can be expressed as an integral operator with the explicit formula for the kernel. As a consequence, conditions for local and global in t...
0912.2113v3
2009-12-18
Polariton crystallization in driven arrays of lossy nonlinear resonators
We investigate the steady states of a lossy array of nonlinear optical resonators that are driven by lasers and interact via mutual photon tunneling. For weak nonlinearities, we find two-mode squeezing of polaritons in modes whose quasi-momenta match the relative phases of the laser drives. For strong nonlinearities th...
0912.3612v2
2009-12-18
Anomalous Light Absorption by Small Particles
A new type of resonant light absorption by a small particle (nanocluster) is reported. The problem cannot be described within the commonly used dipole scattering approximation and should be studied with methods based upon the exact Mie solution. It is shown that the absorption cross-section has giant maxima realized at...
0912.3644v1
2009-12-20
Unconventional state with two coexisting long-range orders for frustrated Heisenberg model at quantum phase transition
For the frustrated two-dimensional $S=1/2$ antiferromagnetic Heisenberg model close to quantum phase transition we consider the singlet ground states retaining both translational and SU(2) symmetry. Besides usually discussed checkerboard, spin-liquid and stripe states an unconventional state with two coexisting long-ra...
0912.4008v1
2009-12-22
Interference of magnetointersubband and phonon-induced resistance oscillations in single GaAs quantum wells with two populated subbands
Low-temperature electron magnetotransport in single GaAs quantum wells with two populated subbands is studied at large filling factors. Magneto-inter-subband (MIS) and acoustic-phonon induced oscillations of the dissipative resistance are found to be coexisting but interfering substantially with each other. The experim...
0912.4366v1
2009-12-22
Collective oscillations in ultracold atomic gases
Using both fluid and kinetic descriptions, where repulsive forces between near by atoms are included, we discuss the basic oscillations and waves of a cloud of ultra-cold atoms confined in a magneto-optical trap. The existence of a hybrid mode, with properties similar to both plasma and acoustic waves is described in d...
0912.4420v1
2009-12-23
Solar-type Variables
The rich acoustic oscillation spectrum in solar-type variables make these stars particularly interesting for studying fluid-dynamical aspects of the stellar interior. I present a summary of the properties of solar-like oscillations, how they are excited and damped and discuss some of the recent progress in using astero...
0912.4622v2