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Within a microscopic theory, we study the quantum Brownian motion of a skyrmion in a magnetic insulator coupled to a bath of magnon-like quantum excitations. The intrinsic skyrmion-bath coupling gives rise to damping terms for the skyrmion…

Mesoscale and Nanoscale Physics · Physics 2019-10-09 Christina Psaroudaki , Pavel Aseev , Daniel Loss

A nonlinear master equation is derived, reflecting properly the entropy of open quantum systems. In contrast to linear alternatives, its equilibrium solution is exactly the canonical Gibbs density matrix. The corresponding nonlinear…

Quantum Physics · Physics 2021-02-08 Roumen Tsekov

The dynamical behavior of quantum coherence of a displaced squeezed thermal state in contact with an external bath is discussed in the present work. We use a Fano-Anderson type of Hamiltonian to model the environment and solve the quantum…

Quantum Physics · Physics 2023-02-17 Md. Manirul Ali , R. Chandrashekar , S. S. Naina Mohammed

The state-dependent diffusion, which concerns the Brownian motion of a particle in inhomogeneous media has been described phenomenologically in a number of ways. Based on a system-reservoir nonlinear coupling model we present a microscopic…

Statistical Mechanics · Physics 2007-05-23 Debashis Barik , Deb Shankar Ray

We propose a Langevin equation for systems in an environment with nonuniform temperature. At odds with an older proposal, ours admits a locally Maxwellian steady state, local equipartition holds and for detailed-balanced (reversible)…

Statistical Mechanics · Physics 2015-06-12 Matteo Polettini

An extended variational principle providing the equations of motion for a system consisting of interacting classical, quasiclassical and quantum components is presented, and applied to the model of bilinear coupling. The relevant dynamical…

Quantum Physics · Physics 2009-11-13 M. Grigorescu

The reduced dynamics of a quantum system interacting with a linear heat bath finds an exact representation in terms of a stochastic Schr{\"o}dinger equation. All memory effects of the reservoir are transformed into noise correlations and…

Statistical Mechanics · Physics 2007-05-23 J. Stockburger , H. Grabert

The quantum Brownian motion paradigm provides a unified framework where one can see the interconnection of some basic quantum statistical processes like decoherence, dissipation, particle creation, noise and fluctuation. We treat the case…

General Relativity and Quantum Cosmology · Physics 2008-11-26 B. L. Hu , Andrew Matacz

In this paper, we derive equations of motion for the normal-order, the symmetric-order and the antinormal-order quantum characteristic functions, applicable for general Hamiltonian systems. We do this by utilizing the `characteristic form'…

Quantum Physics · Physics 2008-05-02 Itay Hen , Amir Kalev

We have revisited the Brownian motion on the basis of the fractional Langevin equation which turns out to be a particular case of the generalized Langevin equation introduced by Kubo on 1966. The importance of our approach is to model the…

Mathematical Physics · Physics 2008-06-06 Francesco Mainardi , Paolo Pironi

We construct a quantum-circuit framework for finite-temperature molecular dynamics in the canonical ensemble (NVT) with a Langevin thermostat, connecting canonical state preparation to subsequent physical-property readouts. The classical…

We study the real time dynamics of a quantum system with potential barrier coupled to a heat-bath environment. Employing the path integral approach an evolution equation for the time dependent density matrix is derived. The time evolution…

Quantum Physics · Physics 2007-05-23 Joachim Ankerhold , Hermann Grabert , Gert-Ludwig Ingold

We consider a microscopic model of an inhomogeneous environment where an arbitrary quantum system is locally coupled to a harmonic bath via a finite-range interaction. We show that in the overdamped regime the position distribution obeys a…

Statistical Mechanics · Physics 2025-02-28 Arthur M. Faria , Marcus V. S. Bonanca , Eric Lutz

We initially prepare a quantum linear oscillator weakly coupled to a bath in equilibrium at an arbitrary temperature. We disturb this system by varying a Hamiltonian parameter of the coupled oscillator, namely, either its spring constant or…

Statistical Mechanics · Physics 2015-05-27 Ilki Kim

To remedy the failure of minimal coupling method in describing the quantum dynamics of two localized Brownian oscillators interacting with a common medium, a scheme is introduced to modeling the medium by a continuum of complex scalar…

Quantum Physics · Physics 2017-08-02 Z. Nasr , F. Kheirandish

Barrier crossing is a widespread phenomenon across natural and engineering systems. While an abundant cross-disciplinary literature on the topic has emerged over the years, the stochastic underpinnings of the process are yet to be linked…

Statistical Mechanics · Physics 2024-12-19 Toby Kay , Luca Giuggioli

The tomographic invertable map of the Wigner function onto the positive probability distribution function is studied. Alternatives to the Schr\"odinger evolution equation and to the energy level equation written for the positive probability…

Quantum Physics · Physics 2016-09-08 Vladimir I. Man'ko

A theory of quantum jumps is developed by using a new asymmetric equation, which is complementary to the Schr\"odinger equation. The new equation displays Bohr's rules for quantum jumps, and its solutions demonstrate that once a quantum…

General Physics · Physics 2025-09-23 Z. E. Musielak

Dynamics simulations of constrained particles can greatly aid in understanding the temporal and spatial evolution of biological processes such as lateral transport along membranes and self-assembly of viruses. Most theoretical efforts in…

Computational Physics · Physics 2017-03-03 Stefan Paquay , Remy Kusters

We revisit the model of a system made up of a Brownian quantum oscillator under the influence of an external classical force and linearly coupled to an environment made up of many quantum oscillators at zero or finite temperature. We show…

Quantum Physics · Physics 2007-05-23 C. H. Fleming , B. L. Hu , Albert Roura