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47
2007-02-07
Damping of antiferromagnetic spin waves by valence fluctuations in the double layer perovskite YBaFe2O5
Inelastic neutron scattering experiments show that spin dynamics in the charge ordered insulating ground state of the double-layer perovskite YBaFe2O5 is well described in terms of eg superexchange interactions. Above the Verwey transition at TV = 308 K, t2g double exchange-type conduction within antiferromagnetic FeO2...
0702181v1
2007-02-20
Spin Drag and Spin-Charge Separation in Cold Fermi Gases
Low-energy spin and charge excitations of one-dimensional interacting fermions are completely decoupled and propagate with different velocities. These modes however can decay due to several possible mechanisms. In this paper we expose a new facet of spin-charge separation: not only the speeds but also the damping rates...
0702466v1
1996-07-23
Quasinormal modes of nearly extreme Reissner-Nordstrom black holes
We present detailed calculations of the quasinormal modes of Reissner-Nordstrom black holes. While the first few, slowly damped, modes depend on the charge of the black hole in a relatively simple way, we find that the rapidly damped modes show several peculiar features. The higher modes generally spiral into the value...
9607054v1
1996-08-22
Gravitational Ionization: A Chaotic Net in the Kepler System
The long term nonlinear dynamics of a Keplerian binary system under the combined influences of gravitational radiation damping and external tidal perturbations is analyzed. Gravitational radiation reaction leads the binary system towards eventual collapse, while the external periodic perturbations could lead to the ion...
9608054v1
1999-11-11
Inertial Control of the VIRGO Superattenuator
The VIRGO superattenuator (SA) is effective in depressing the seismic noise below the thermal noise level above 4 Hz. On the other hand, the residual mirror motion associated to the SA normal modes can saturate the dynamics of the interferometer locking system. This motion is reduced implementing a wideband (DC-5 Hz) m...
9911044v1
2002-10-30
Massive charged scalar field in a Reissner-Nordstrom black hole background: quasinormal ringing
We compute characteristic (quasinormal) frequencies corresponding to decay of a massive charged scalar field in a Reissner-Nordstrom black hole background. It proves that, contrary to the behavior at very late times, at the stage of quasinormal ringing the neutral perturbations will damp slower than the charged ones. I...
0210105v3
2003-03-20
Dirac Quasi-Normal Modes in Schwarzschild Black Hole Spacetimes
We evaluate both the massless and the massive Dirac quasi-normal mode frequencies in the Schwarzschild black hole spacetime using the WKB approximation. For the massless case, we find that, similar to those for the integral spin fields, the real parts of the frequencies increase with the angular momentum number $\kappa...
0303078v1
2003-07-31
Effects of electrical charging on the mechanical Q of a fused silica disk
We report on the effects of an electrical charge on mechanical loss of a fused silica disk. A degradation of Q was seen that correlated with charge on the surface of the sample. We examine a number of models for charge damping, including eddy current damping and loss due to polarization. We conclude that rubbing fricti...
0308001v1
2004-09-15
Rippled Cosmological Dark Matter from Damped Oscillating Newton Constant
Let the reciprocal Newton 'constant' be an apparently non-dynamical Brans-Dicke scalar field damped oscillating towards its General Relativistic VEV. We show, without introducing additional matter fields or dust, that the corresponding cosmological evolution averagely resembles, in the Jordan frame, the familiar dark r...
0409059v2
2004-10-06
Thermoelastic-damping noise from sapphire mirrors in a fundamental-noise-limited interferometer
We report the first high-precision interferometer using large sapphire mirrors, and we present the first direct, broadband measurements of the fundamental thermal noise in these mirrors. Our results agree well with the thermoelastic-damping noise predictions of Braginsky, et al. [Phys. Lett. A 264, 1(1999)] and Cerdoni...
0410028v1
2004-10-28
Gravitational waves from neutron stars described by modern EOS
The frequencies and damping times of neutron star (and quark star) oscillations have been computed using the most recent equations of state available in the literature. We find that some of the empirical relations that connect the frequencies and damping times of the modes to the mass and radius of the star, and that w...
0410140v1
2005-06-08
Resonant growth of stellar oscillations by incident gravitational waves
Stellar oscillation under the combined influences of incident gravitational wave and radiation loss is studied in a simple toy model. The star is approximated as a uniform density ellipsoid in the Newtonian gravity including radiation damping through quadrupole formula. The time evolution of the oscillation is signific...
0506047v1
2006-11-28
Massive scalar field quasinormal modes of a Schwarzschild black hole surrounded by quintessence
We present the quasinormal frequencies of the massive scalar field in the background of a Schwarzchild black hole surrounded by quintessence with the third-order WKB method. The mass of the scalar field $u$ plays an important role in studying the quasinormal frequencies, the real part of the frequencies increases linea...
0611146v2
1992-09-24
Non-Abelian Boltzmann Equation for Mixing and Decoherence
We consider particle oscillations and their damping in second-quantized form. We find that the damping or "decoherence" may be described by a Boltzmann-like collision integral with "non-abelian blocking factors" (fermions). Earlier results are generalized in that the momentum degrees of freedom are included and that th...
9209276v1
1993-06-03
The heavy fermion damping rate puzzle
: We examine again the problem of the damping rate of a moving heavy fermion in a hot plasma within the resummed perturbative theory of Pisarski and Braaten. The ansatz for its evaluation which relates it to the imaginary part of the fermion propagator pole in the framework of a self-consistent approach is critically a...
9306219v1
1993-09-03
Damping Rate of a Fermion in a Medium
We examine the relation between the damping rate of a massless, chiral fermion that propagates in a medium, and the rate $\Gamma$ of approach to equilibrium. It is proven that these quantities are equal, by showing that they are given by the same formula in terms of the imaginary part of the self-energy evaluated at th...
9309225v2
1994-03-22
On the Damping Rate of a Fast Fermion in Hot QED
The self-consistent determination of the damping rate of a fast moving fermion in a hot QED plasma is reexamined. We argue how a detailed investigation of the analytic properties of the retarded fermion Green's function motivated by the cutting rules at finite temperature may resolve ambiguities related to the proper d...
9403335v1
1994-09-12
Fermion damping rate in a hot medium
In principle every excitation acquires a finite lifetime in a hot system. This nonzero spectral width is calculated self-consistently for massive fermions coupled to massless scalar, vector and pseudoscalar bosons. It is shown that the self-consistent summation of the corresponding Fock diagram for fermions eliminates ...
9409280v2
1994-09-22
Lyapunov Exponent and Plasmon Damping Rate in Nonabelian Gauge Theories
We explain why the maximal positive Lyapunov exponent of classical SU($N$) gauge theory coincides with (twice) the damping rate of a plasmon at rest in the leading order of thermal gauge theory. [This is a substantially revised and expanded version of the manuscript.]
9409392v2
1994-12-20
Baryogenesis and damping in nonminimal electroweak models
We study the effect of damping on the generation of baryon asymmetry of the Universe in the standard model of the eletroweak theory with simple extensions of the Higgs sector. The propagation of quarks of masses up to about 5 GeV are considered, taking into account their markedly different dispersion relations due to i...
9412330v1
1998-10-07
Classical Kinetic Theory of Landau Damping for Self-interacting Scalar Fields in the Broken Phase
The classical kinetic theory of one-component self-interacting scalar fields is formulated in the broken symmetry phase and applied to the phenomenon of Landau damping. The domain of validity of the classical approach is found by comparing with the result of a 1-loop quantum calculation.
9810278v2
1999-08-02
Plasma wave instabilities induced by neutrinos
Quantum field theory is applied to study the interaction of an electron plasma with an intense neutrino flux. A connection is established between the field theory results and classical kinetic theory. The dispersion relation and damping rate of the plasma longitudinal waves are derived in the presence of neutrinos. It ...
9908206v2
1999-09-27
Radiation Damping at a Bubble Wall
The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocit...
9909521v1
1999-10-08
Lifetime of Collective Isospin Rotations of a Quantum Meson Field
We calculate the lifetime of the collective isospin rotating solutions which have been found recently in the case a quantum N-component meson field with exact O(N) symmetry. For this purpose we take into account the small breaking of the O(N) symmetry associated to the non vanishing mass of the pion. This term induces ...
9910276v1
2000-02-08
Finite pion width effects on the rho-meson and di-lepton spectra
Within a field theoretical model where all damping width effects are treated self-consistently we study the changes of the spectral properties of rho-mesons due to the finite damping width of the pions in dense hadronic matter at finite temperature. The corresponding effects in the di-lepton yields are presented. Some ...
0002087v1
2000-08-31
Damping of very soft moving quarks in high-temperature QCD
We determine the analytic expression of the damping rates for very soft moving quarks in an expansion to second order in powers of their momentum in the context of QCD at high temperature. The calculation is performed using the hard-thermal-loop-summed perturbation scheme. We describe the range of validity of the expan...
0008335v1
2000-09-27
Damping of the HERA effect in DIS?
The drastic rise of the proton structure function F_2(x,Q^2) when the Bj\"orken variable x decreases, seen at HERA for a large span of Q^2, negative values for the 4-momentum transfer, may be damped when Q^2 increases beyond several hundreds GeV^2. A new data analysis and a comparison with recent models for the proton ...
0009313v2
2001-12-13
Time evolution in linear response: Boltzmann equations and beyond
In this work a perturbative linear response analysis is performed for the time evolution of the quasi-conserved charge of a scalar field. One can find two regimes, one follows exponential damping, where the damping rate is shown to come from quantum Boltzmann equations. The other regime (coming from multiparticle cuts ...
0112188v1
2002-04-26
Oscillation damping of chiral string loops
Chiral cosmic string loop tends to the stationary (vorton) configuration due to the energy loss into the gravitational and electromagnetic radiation. We describe the asymptotic behaviour of near stationary chiral loops and their fading to vortons. General limits on the gravitational and electromagnetic energy losses by...
0204304v1
2004-02-06
Critical Behavior of Damping Rate for Plasmon with Finite Momentum in φ^4 Theory
Applying thermal renormalization group (TRG) equations to $\phi^4$ theory with spontaneous breaking symmetry, we investigate the critical behavior of the damping rate for the plasmons with finite momentum at the symmetry-restoring phase transition. From the TRG equation the IR cutoff provided by the external momentum l...
0402069v2
2005-11-22
Ultrasoft Quark Damping in Hot QCD
We determine the quark damping rates in the context of next-to-leading order hard-thermal-loop summed perturbation of high-temperature QCD where weak coupling is assumed. The quarks are ultrasoft. Three types of divergent behavior are encountered: infrared, light-cone and at specific points determined by the gluon ener...
0511258v1
2006-03-10
Numerical Approach to Multi Dimensional Phase Transitions
We present an algorithm to analyze numerically the bounce solution of first-order phase transitions. Our approach is well suited to treat phase transitions with several fields. The algorithm consists of two parts. In the first part the bounce solution without damping is determined, in which case energy is conserved. In...
0603081v2
1994-06-22
Damped quantum harmonic oscillator: density operator and related quantities
A closed expression for the density operator of the damped harmonic oscillator is extracted from the master equation based on the Lindblad theory for open quantum systems. The entropy and effective temperature of the system are subsequently calculated and their temporal behaviour is surveyed by showing how these quanti...
9406142v1
1997-05-09
Radiation Damping of a BPS Monopole; an Implication to S-duality
The radiation reaction of a BPS monopole in the presence of incident electromagnetic waves as well as massless Higgs waves is analyzed classically. The reactive forces are compared to those of $W$ boson that is interpreted as a dual partner of the BPS monopole. It is shown that the damping of acceleration is dual to ea...
9705059v2
1997-07-02
The Asymptotic Method Developed from Weak Turbulent Theory and the Nonlinear Permeability and Damping Rate in QGP
With asymptotic method developed from weak turbulent theory, the kinetic equations for QGP are expanded in fluctuation field potential $A^T_\mu $. Considering the second-order and third-order currents, we derive the nonlinear permeability tensor function from Yang-Mills field equation, and find that the third-order cur...
9707052v1
2005-04-07
Continuous area spectrum in regular black hole
We investigate highly damped quasinormal modes of regular black hole coupled to nonlinear electrodynamics. Using the WKB approximation combined with complex-integration technique, we show that the real part of the frequency disappears in the highly damped limit. If we use the Bohr's correspondence principle, the area s...
0504059v2
2005-05-16
Supersymmetrization of the Radiation Damping
We construct a supersymmetrized version of the model to the radiation damping \cite{03} introduced by the present authors \cite{ACWF}. We dicuss its symmetries and the corresponding conserved Noether charges. It is shown this supersymmetric version provides a supersymmetric generalization of the Galilei algebra obtaine...
0505142v1
1999-08-16
Topological Entropy and epsilon-Entropy for Damped Hyperbolic Equations
We study damped hyperbolic equations on the infinite line. We show that on the global attracting set $G$ the $\epsilon$-entropy (per unit length) exists in the topology of $W^{1,\infty}$. We also show that the topological entropy per unit length of $G$ exists. These results are shown using two main techniques: Bounds i...
9908080v1
2003-11-28
Uniform stability of damped nonlinear vibrations of an elastic string
Here we are concerned about uniform stability of damped nonlinear transverse vibrations of an elastic string fixed at its two ends. The vibrations governed by nonlinear integro-differential equation of Kirchoff type, is shown to possess energy uniformly bounded by exponentially decaying function of time. The result is ...
0311527v1
2005-07-06
On stability and stabilization of elastic systems by time-variant feedback
We study a class of elastic systems described by a (hyperbolic) partial differential equation. Our working example is the equation of a vibrating string subject to linear disturbance. The main goal is to establish conditions for stabilization and asymptotic stabilization by applying a fast oscillating control to the st...
0507123v1
2006-01-13
Attractors for damped hyperbolic equations on arbitrary unbounded domains
We prove existence of global attractors for damped hyperbolic equations of the form $$\aligned \eps u_{tt}+\alpha(x) u_t+\beta(x)u- \sum_{ij}(a_{ij}(x) u_{x_j})_{x_i}&=f(x,u),\quad x\in \Omega, t\in[0,\infty[, u(x,t)&=0,\quad x\in \partial \Omega, t\in[,\infty[.\endaligned$$ on an unbounded domain $\Omega$, without smo...
0601319v3
2007-02-07
Finite time blow-up results for the damped wave equations with arbitrary initial energy in an inhomogeneous medium
In this paper we consider the long time behavior of solutions of the initial value problem for the damped wave equation of the form \begin{eqnarray*} u_{tt}-\rho(x)^{-1}\Delta u+u_t+m^2u=f(u) \end{eqnarray*} with some $\rho(x)$ and $f(u)$ on the whole space $\R^n$ ($n\geq 3$). For the low initial energy case, which i...
0702190v1
2007-03-09
Analyticity and Riesz basis property of semigroups associated to damped vibrations
Second order equations of the form $z'' + A_0 z + D z'=0$ in an abstract Hilbert space are considered. Such equations are often used as a model for transverse motions of thin beams in the presence of damping. We derive various properties of the operator matrix $A$ associated with the second order problem above. We deve...
0703247v1
2007-03-21
Existence and asymptotic behavior of $C^1$ solutions to the multidimensional compressible Euler equations with damping
In this paper, the existence and asymptotic behavior of $C^1$ solutions to the multidimensional compressible Euler equations with damping on the framework of Besov space are considered. We weaken the regularity requirement of the initial data, and improve the well-posedness results of Sideris-Thomases-Wang (Comm.P.D.E....
0703621v1
2000-12-22
The Vlasov-Poisson system with radiation damping
We set up and analyze a model of radiation damping within the framework of continuum mechanics, inspired by a model of post-Newtonian hydrodynamics due to Blanchet, Damour and Schaefer. In order to simplify the problem as much as possible we replace the gravitational field by the electromagnetic field and the fluid by ...
0012041v1
2003-01-17
Quantum mechanics of damped systems
We show that the quantization of a simple damped system leads to a self-adjoint Hamiltonian with a family of complex generalized eigenvalues. It turns out that they correspond to the poles of energy eigenvectors when continued to the complex energy plane. Therefore, the corresponding generalized eigenvectors may be int...
0301024v3
2003-07-23
Quantum Mechanics of Damped Systems II. Damping and Parabolic Potential Barrier
We investigate the resonant states for the parabolic potential barrier known also as inverted or reversed oscillator. They correspond to the poles of meromorphic continuation of the resolvent operator to the complex energy plane. As a byproduct we establish an interesting relation between parabolic cylinder functions (...
0307047v1
2001-07-02
Pattern formation and localization in the forced-damped FPU lattice
We study spatial pattern formation and energy localization in the dynamics of an anharmonic chain with quadratic and quartic intersite potential subject to an optical, sinusoidally oscillating field and a weak damping. The zone-boundary mode is stable and locked to the driving field below a critical forcing that we det...
0107002v1
2003-06-16
On the influence of noise on chaos in nearly Hamiltonian systems
The simultaneous influence of small damping and white noise on Hamiltonian systems with chaotic motion is studied on the model of periodically kicked rotor. In the region of parameters where damping alone turns the motion into regular, the level of noise that can restore the chaos is studied. This restoration is create...
0306024v1
2003-07-30
Faraday Wave Pattern Selection Via Multi-Frequency Forcing
We use symmetry considerations to investigate how damped modes affect pattern selection in multi-frequency forced Faraday waves. We classify and tabulate the most important damped modes and determine how the corresponding resonant triad interactions depend on the forcing parameters. The relative phase of the forcing te...
0307056v1
2004-10-21
Stabilization mechanism for two-dimensional solitons in nonlinear parametric resonance
We consider a simple model system supporting stable solitons in two dimensions. The system is the parametrically driven damped nonlinear Schr\"odinger equation, and the soliton stabilises for sufficiently strong damping. The purpose of this note is to elucidate the stabilisation mechanism; we do this by reducing the pa...
0410044v1
2006-01-14
Vibration of the Duffing Oscillator: Effect of Fractional Damping
We have applied the Melnikov criterion to examine a global homoclinic bifurcation and transition to chaos in a case of the Duffing system with nonlinear fractional damping and external excitation. Using perturbation methods we have found a critical forcing amplitude above which the system may behave chaotically. Th...
0601033v1
2006-11-02
Solitons in strongly driven discrete nonlinear Schrödinger-type models
Discrete solitons in the Ablowitz-Ladik (AL) and discrete nonlinear Schr\"odinger (DNLS) equations with damping and strong rapid drive are investigated. The averaged equations have the forms of the parametric AL and DNLS equations. A new type of parametric bright discrete soliton and cnoidal waves are found and the sta...
0611004v1
2006-11-26
On the Lagrangian and Hamiltonian description of the damped linear harmonic oscillator
Using the modified Prelle- Singer approach, we point out that explicit time independent first integrals can be identified for the damped linear harmonic oscillator in different parameter regimes. Using these constants of motion, an appropriate Lagrangian and Hamiltonian formalism is developed and the resultant canonica...
0611048v1
1992-12-14
Microscopic Origin of Quantum Chaos in Rotational Damping
The rotational spectrum of $^{168}$Yb is calculated diagonalizing different effective interactions within the basis of unperturbed rotational bands provided by the cranked shell model. A transition between order and chaos taking place in the energy region between 1 and 2 MeV above the yrast line is observed, associated...
9212005v1
1996-12-17
Damping mechanisms of the Delta resonance in nuclei
The damping mechanisms of the Delta(1232) resonance in nuclei are studied by analyzing the quasi-free decay reactions 12C(pi+,pi+ p)11B and 12C(3He,t pi+ p)11B and the 2p emission reactions 12C(pi+,pp)10B and 12C(3He,t pp)10B. The coincidence cross sections are calculated within the framework of the isobar-hole model. ...
9612046v1
1997-11-08
Cooperative damping mechanism of the resonance in the nuclear photoabsorption
We propose a resonance damping mechanism to explain the disappearance of the peaks around the position of the resonances higher than the $\Delta$ resonance in the nuclear photoabsorption. This phenomenon is understood by taking into account the cooperative effect of the collision broadening of $\Delta$ and $N^{*}$, the...
9711017v4
1998-05-27
Collisional Damping of Nuclear Collective Vibrations in a Non-Markovian Transport Approach
A detailed derivation of the collisional widths of collective vibrations is presented in both quantal and semi-classical frameworks by considering the linearized limits of the extended TDHF and the BUU model with a non-Markovian binary collision term. Damping widths of giant dipole and giant quadrupole excitations are ...
9805050v1
1999-07-06
Probing the width of compound states with rotational gamma rays
The intrinsic width of (multiparticle-multihole) compound states is an elusive quantity, of difficult direct access, as it is masked by damping mechanisms which control the collective response of nuclei. Through microscopic cranked shell model calculations, it is found that the strength function associated with two-dim...
9907016v1
1999-07-09
Color plasma oscillation in strangelets
The dispersion relation and damping rate of longitudinal color plasmons in finite strange quark matter (strangelets) are evaluated in the limits of weak coupling, low temperature, and long wavelength. The property of the QCD vacuum surrounding a strangelet makes the frequency of the plasmons nearly the same as the colo...
9907039v1
1999-09-21
On the Collisional Damping of Giant Dipole Resonance
Collisional damping widths of giant dipole excitations are calculated in Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Gogny force. The results obtained in both calculations compare well, but account for about 25-35% of the observed widths ...
9909057v1
2000-01-09
Strongly damped nuclear collisions: zero or first sound ?
The relaxation of the collective quadrupole motion in the initial stage of a central heavy ion collision at beam energies $E_{lab}=5\div20$ AMeV is studied within a microscopic kinetic transport model. The damping rate is shown to be a non-monotonic function of E_{lab} for a given pair of colliding nuclei. This fact is...
0001016v1
2002-11-18
Collision damping in the pi 3He -> d'N reaction near the threshold
We present a simple quantum mechanical model exploiting the optical potential approach for the description of collision damping in the reaction pi 3He -> d'N near the threshold, which recently has been measured at TRIUMF. The influence of the open d'N -> NNN channel is taken into account. It leads to a suppression fact...
0211050v1
2003-03-14
Pion damping width from SU(2) x SU(2) NJL model
Within the framework of the NJL model, we investigate the modification of the pion damping width in a hot pion gas for temperatures ranging from 0 to 180 MeV. The pion is found to broaden noticeably at T > 60 MeV. Near the chiral phase transition T ~ 180 MeV, the pion width is saturated and amounts to 70 MeV. The main ...
0303034v1
2004-06-09
Damped collective motion of isolated many body systems within a variational approach to functional integrals
Two improvements with respect to previous formulations are presented for the calculation of the partition function $\mathcal{Z}$ of small, isolated and interacting many body systems. By including anharmonicities and employing a variational approach quantum effects can be treated even at very low temperatures. A method ...
0406025v1
2004-07-26
Damped collective motion of many body systems: A variational approach to the quantal decay rate
We address the problem of collective motion across a barrier like encountered in fission. A formula for the quantal decay rate is derived which bases on a recently developed variational approach for functional integrals. This formula can be applied to low temperatures that have not been accessible within the former PSP...
0407092v2
1997-11-15
Fluctuational phase-flip transitions in parametrically pumped oscillators
We analyze the rates of noise-induced transitions between period-two attractors. The model investigated is an underdamped oscillator parametrically driven by a field at nearly twice the oscillator eigenfrequency. The activation energy of the transitions is analyzed as a function of the frequency detuning and field ampl...
9711014v1
1999-05-31
Collisionless Damping of Low-Frequency Magnetosonic Pulses in a Two-Ion-Species Plasma
Low-frequency mangnetosonic pulses in a two-ion-species plasma are studied theoretically and by simulation with a one-dimensional electromagnetic simulation code based on a three-fluid model, with particular attention to the dynamics of minority heavy ions. It is found that heavy ions can gain some energy from the puls...
9905059v1
2000-10-17
Bunch Length Measurements at the ATF Damping Ring in April 2000
This report presents bunch length and energy spread measurements performed in April 2000 at the ATF Damping Ring, at KEK. Measurements were performed with the beam on and then off the linear (difference) coupling resonance. Due to strong intra-beam scattering in the ATF ring, the results depended strongly on the coupli...
0010043v1
2000-12-21
Phase transition in the collisionless regime for wave-particle interaction
Gibbs statistical mechanics is derived for the Hamiltonian system coupling self-consistently a wave to N particles. This identifies Landau damping with a regime where a second order phase transition occurs. For nonequilibrium initial data with warm particles, a critical initial wave intensity is found: above it, thermo...
0012053v1
2001-09-25
Creep and Mechanical Oscillator Damping
Although "friction" is included in many models of oscillator damping, including viscous ones applied to the pendulum; they "miss the mark" with regard to a conceptual understanding of the mechanisms responsible for energy loss. The theory of the present paper corrects some of these misunderstandings by considering the ...
0109067v1
2001-11-06
Electromagnetic induction and damping - quantitative experiments using PC interface
A bar magnet, attached to an oscillating system, passes through a coil periodically, generating a series of emf pulses. A novel method is described for the quantitative verification of Faraday's law which eliminates all errors associated with angular measurements, thereby revealing delicate features of the underlying m...
0111016v1
2003-08-31
Effects of Bulk Viscosity in Non-linear Bubble Dynamics
The non-linear bubble dynamics equations in a compressible liquid have been modified considering the effects of compressibility of both the liquid and the gas at the bubble interface. A new bubble boundary equation has been derived, which includes a new term resulted from the liquid bulk viscosity effects. The influenc...
0309012v1
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
2005-02-10
Modulational instabilities in Josephson oscillations of elongated coupled condensates
We study the Josephson oscillations of two coupled elongated condensates. Linearized calculations show that the oscillating mode uniform over the length of the condensates (uniform Josephson mode) is unstable : modes of non zero longitudinal momentum grow exponentially. In the limit of strong atom interactions, we give...
0502050v3
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