Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

The Journal of Chemical Physics

Dissipation in media with memory: A master equation in the statistical resonance approximation

Joshua Wilkie

Published May 8, 2001• 45 citations
Publisher

Abstract

A non-Markovian master equation is derived for the reduced probability density matrix of a subsystem interacting with a general reservoir of coupled anharmonic modes. Relaxation of the subsystem is mediated through resonant interactions with the reservoir. These interactions correspond to local vibrational motions with finite lifetimes due to diffusion/dephasing. The derivation assumes that the density of these interaction modes is very large so that they can be treated using statistical methods. The resulting master equation is shown to preserve probability, Hermiticity, and translational invariance, and conditions are stated which guarantee the positivity of the reduced density. At long time the master equation reduces to a Markovian equation of dynamical semigroup type. In the high temperature limit the theory is parameter free, and shows good agreement with the exact master equation of a spin-boson system.

DOI
10.1063/1.1365955

Related papers

Spectral density, memory function, and mean relaxation time for resonant subsystem-reservoir interactions

Joshua Wilkie

We show that the projection operators P usually employed to derive the Nakajima–Zwanzig master equation are non-Hermitian. As a consequence the operator QLQ which governs the dynamics of subsystem-reservoir interactions (here Q=1−P and L is the Liouville operator) is also non-Hermitian and possesses a complex temperature-dependent spectrum of resonances. We use the self-consistent Born approximation to derive a formula for the spectral density of QLQ. From this spectral density we calculate the memory function and mean relaxation time of subsystem-reservoir correlations. These formulas are compared with numerical results obtained from the spin–spin-bath model to test their accuracy. The memory function and mean relaxation time are essential ingredients for the SRA (statistical resonance approximation) theory of microscopic dissipation and decoherence. We show that the SRA master equation preserves positivity when the memory function derived in this paper is employed.

The Journal of Chemical Physics•Dec 8, 2001•24 citations

Master equation for strongly interacting systems

H. J. Carmichael, Daniel F. Walls

A dissipating system consisting of two strongly interacting subsystems, each coupled to its respective thermal reservoir is considered. The usual method for obtaining a master equation for the reduced density operator of such a system is to assume the factorization of this density operator in the derivation of the irreversible term, retaining the coupling in the reversible term alone. This approach has the serious limitation that it fails to preserve detailed balance in general and yields an incorrect canonical form for the stationary solution of the density operator. A general approach, based on the introduction of a new interaction picture, is presented. This method is illustrated by applying it to a coupled boson system and to a two-level atom interacting with a single mode of the electromagnetic field.

Journal of Physics A Mathematical Nuclear and General•Oct 1, 1973•87 citations

Dissipations in coupled quantum systems

Hashem Zoubi, Meir Orenstien, Amiram Ron

We investigate the dynamics of a composite quantum system, comprised of coupled subsystems, of which only one is significantly interacting with the environment. The validity of the conventional ad hoc approach---assuming that relaxation terms can be extracted directly from the master equation of the subsystem interacting with the reservoir---was examined. We derived the equation of motion for the composite system's reduced density matrix---applying only the factorization approximation, but not the conventional sequence of Markoff, coarse grain, and secular approximations. From our analysis, we concluded that the conventional ad hoc approach is applicable to zero-temperature reservoir, but fails for finite temperatures. It is further shown that at finite temperatures, the standard procedure does not even yield a master equation for the composite system, and its dynamics has to be studied by the equations of motion which are developed here. For demonstration we considered a system of a three-level atom, the two excited states are coupled to each other, and only one of them communicates with the ground state via a radiation reservoir.

Physical Review A•Jun 24, 2003•13 citations

Decoherence and quantum-classical master equation dynamics

Robbie Grunwald, Raymond Kapral

The conditions under which quantum-classical Liouville dynamics may be reduced to a master equation are investigated. Systems that can be partitioned into a quantum-classical subsystem interacting with a classical bath are considered. Starting with an exact non-Markovian equation for the diagonal elements of the density matrix, an evolution equation for the subsystem density matrix is derived. One contribution to this equation contains the bath average of a memory kernel that accounts for all coherences in the system. It is shown to be a rapidly decaying function, motivating a Markovian approximation on this term in the evolution equation. The resulting subsystem density matrix equation is still non-Markovian due to the fact that bath degrees of freedom have been projected out of the dynamics. Provided the computation of nonequilibrium average values or correlation functions is considered, the non-Markovian character of this equation can be removed by lifting the equation into the full phase space of the system. This leads to a trajectory description of the dynamics where each fictitious trajectory accounts for decoherence due to the bath degrees of freedom. The results are illustrated by computations of the rate constant of a model nonadiabatic chemical reaction.

arXiv:cond-mat/0612203•The Journal of Chemical Physics•Mar 20, 2007•23 citations

Quantum master equation for a system influencing its environment

Massimiliano Esposito, Pierre Gaspard

A perturbative quantum master equation is derived for a system interacting with its environment, which is more general than the ones derived before. Our master equation takes into account the effect of the energy exchanges between the system and the environment and the conservation of energy in the finite total system. This master equation describes relaxation mechanisms in isolated nanoscopic quantum systems. In its most general form, this equation is non-Markovian and a Markovian version of it rules the long-time relaxation. We show that our equation reduces to the Redfield equation in the limit where the energy of the system does not affect the density of state of its environment. This master equation and the Redfield one are applied to a spin-environment model defined in terms of random matrices and compared with the solutions of the exact von Neumann equation. The comparison proves the necessity to allow energy exchange between the subsystem and the environment in order to correctly describe the relaxation in an isolated nanoscopic total system.

arXiv:cond-mat/0306433•Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics•Dec 24, 2003•77 citations

Master equation and dispersive probing of a non-Markovian process

Li‐Ping Yang, C. Y. Cai, Dazhi Xu +2 more

For a bosonic (fermionic) open system in a bath with many bosonic (fermionic) modes, we derive the exact non-Markovian master equation in which the memory effect of the bath is reflected in the time-dependent decay rates. In this approach, the reduced density operator is constructed from the formal solution of the corresponding Heisenberg equations. As an application of the exact master equation, we study the active probing of the non-Markovianity of the quantum dissipation of a single bosonic mode of an electromagnetic field in a cavity-QED system. The non-Markovianity of the bath of the cavity is explicitly reflected by the atomic decoherence factor.

arXiv:1209.5510•Physical Review A•Jan 11, 2013•26 citations
A non-Markovian master equation is derived for the reduced probability density matrix of a subsystem interacting with a general reservoir of coupled anharmonic modes. Relaxation of the subsystem is mediated through resonant interactions with the reservoir. These interactions correspond to local vibrational motions with finite lifetimes due to diffusion/dephasing. The derivation assumes that the density of these interaction modes is very large so that they can be treated using statistical methods. The resulting master equation is shown to preserve probability, Hermiticity, and translational invariance, and conditions are stated which guarantee the positivity of the reduced density. At long time the master equation reduces to a Markovian equation of dynamical semigroup type. In the high temperature limit the theory is parameter free, and shows good agreement with the exact master equation of a spin-boson system.
We show that the projection operators P usually employed to derive the Nakajima–Zwanzig master equation are non-Hermitian. As a consequence the operator QLQ which governs the dynamics of subsystem-reservoir interactions (here Q=1−P and L is the Liouville operator) is also non-Hermitian and possesses a complex temperature-dependent spectrum of resonances. We use the self-consistent Born approximation to derive a formula for the spectral density of QLQ. From this spectral density we calculate the memory function and mean relaxation time of subsystem-reservoir correlations. These formulas are compared with numerical results obtained from the spin–spin-bath model to test their accuracy. The memory function and mean relaxation time are essential ingredients for the SRA (statistical resonance approximation) theory of microscopic dissipation and decoherence. We show that the SRA master equation preserves positivity when the memory function derived in this paper is employed.
A dissipating system consisting of two strongly interacting subsystems, each coupled to its respective thermal reservoir is considered. The usual method for obtaining a master equation for the reduced density operator of such a system is to assume the factorization of this density operator in the derivation of the irreversible term, retaining the coupling in the reversible term alone. This approach has the serious limitation that it fails to preserve detailed balance in general and yields an incorrect canonical form for the stationary solution of the density operator. A general approach, based on the introduction of a new interaction picture, is presented. This method is illustrated by applying it to a coupled boson system and to a two-level atom interacting with a single mode of the electromagnetic field.
We investigate the dynamics of a composite quantum system, comprised of coupled subsystems, of which only one is significantly interacting with the environment. The validity of the conventional ad hoc approach---assuming that relaxation terms can be extracted directly from the master equation of the subsystem interacting with the reservoir---was examined. We derived the equation of motion for the composite system's reduced density matrix---applying only the factorization approximation, but not the conventional sequence of Markoff, coarse grain, and secular approximations. From our analysis, we concluded that the conventional ad hoc approach is applicable to zero-temperature reservoir, but fails for finite temperatures. It is further shown that at finite temperatures, the standard procedure does not even yield a master equation for the composite system, and its dynamics has to be studied by the equations of motion which are developed here. For demonstration we considered a system of a three-level atom, the two excited states are coupled to each other, and only one of them communicates with the ground state via a radiation reservoir.
The conditions under which quantum-classical Liouville dynamics may be reduced to a master equation are investigated. Systems that can be partitioned into a quantum-classical subsystem interacting with a classical bath are considered. Starting with an exact non-Markovian equation for the diagonal elements of the density matrix, an evolution equation for the subsystem density matrix is derived. One contribution to this equation contains the bath average of a memory kernel that accounts for all coherences in the system. It is shown to be a rapidly decaying function, motivating a Markovian approximation on this term in the evolution equation. The resulting subsystem density matrix equation is still non-Markovian due to the fact that bath degrees of freedom have been projected out of the dynamics. Provided the computation of nonequilibrium average values or correlation functions is considered, the non-Markovian character of this equation can be removed by lifting the equation into the full phase space of the system. This leads to a trajectory description of the dynamics where each fictitious trajectory accounts for decoherence due to the bath degrees of freedom. The results are illustrated by computations of the rate constant of a model nonadiabatic chemical reaction.
A perturbative quantum master equation is derived for a system interacting with its environment, which is more general than the ones derived before. Our master equation takes into account the effect of the energy exchanges between the system and the environment and the conservation of energy in the finite total system. This master equation describes relaxation mechanisms in isolated nanoscopic quantum systems. In its most general form, this equation is non-Markovian and a Markovian version of it rules the long-time relaxation. We show that our equation reduces to the Redfield equation in the limit where the energy of the system does not affect the density of state of its environment. This master equation and the Redfield one are applied to a spin-environment model defined in terms of random matrices and compared with the solutions of the exact von Neumann equation. The comparison proves the necessity to allow energy exchange between the subsystem and the environment in order to correctly describe the relaxation in an isolated nanoscopic total system.
For a bosonic (fermionic) open system in a bath with many bosonic (fermionic) modes, we derive the exact non-Markovian master equation in which the memory effect of the bath is reflected in the time-dependent decay rates. In this approach, the reduced density operator is constructed from the formal solution of the corresponding Heisenberg equations. As an application of the exact master equation, we study the active probing of the non-Markovianity of the quantum dissipation of a single bosonic mode of an electromagnetic field in a cavity-QED system. The non-Markovianity of the bath of the cavity is explicitly reflected by the atomic decoherence factor.