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Related papers: Semiclassical Ehrenfest paths in open quantum syst…

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An adapted representation of quantum mechanics sheds new light on the relationship between quantum states and classical states. In this approach the space of quantum states splits into a product of the state space of classical mechanics and…

High Energy Physics - Theory · Physics 2021-04-14 Christoph Nölle

Computing the stochastic entropy production associated with the evolution of a stochastic dynamical system is a well-established problem. In a small number of cases such as the Ornstein-Uhlenbeck process, of which we give a complete…

Statistical Mechanics · Physics 2020-08-26 Richard J Martin , Ian J Ford

We calculate the Ehrenfest-time dependence of the leading quantum correction to the spectral form factor of a ballistic chaotic cavity using periodic orbit theory. For the case of broken time-reversal symmetry, our result differs from that…

Chaotic Dynamics · Physics 2007-08-22 Piet W. Brouwer , Saar Rahav , Chushun Tian

We recently derived a spin-mapping approach for treating the nonadiabatic dynamics of a two-level system in a classical environment [J. Chem. Phys. 151, 044119 (2019)] based on the well-known quantum equivalence between a two-level system…

Chemical Physics · Physics 2020-03-03 Johan E. Runeson , Jeremy O. Richardson

The semiclassically scaled time-dependent multi-particle Schr\"odinger equation describes, inter alia, quantum dynamics of nuclei in a molecule. It poses the combined computational challenges of high oscillations and high dimensions. This…

Numerical Analysis · Mathematics 2020-12-02 Caroline Lasser , Christian Lubich

The behaviour of classical mechanical systems is characterised by their phase portraits, the collections of their trajectories. Heisenberg's uncertainty principle precludes the existence of sharply defined trajectories, which is why…

Quantum Physics · Physics 2013-01-28 Ole Steuernagel , Dimitris Kakofengitis , Georg Ritter

We propose a new semi-discretization scheme to approximate nonlinear Fokker-Planck equations, by exploiting the gradient flow structures with respect to the 2-Wasserstein metric. We discretize the underlying state by a finite graph and…

Numerical Analysis · Mathematics 2017-12-20 Shui-Nee Chow , Luca Dieci , Wuchen Li , Haomin Zhou

We consider the interaction dynamics of a classical oscillator and a quantum two-level system for different pure-dephasing Hamiltonians of the type $\widehat{H}(q,p)=H_C(q,p)\boldsymbol{1}+H_I(q,p)\widehat\sigma_z$. This type of systems…

Chemical Physics · Physics 2023-03-15 Giovanni Manfredi , Antoine Rittaud , Cesare Tronci

Due to the exponential growth of the state space of coupled quantum systems it is not possible, in general, to numerically store the state of a very large number of quantum systems within a classical computer. We demonstrate a method for…

Quantum Physics · Physics 2017-02-07 J. J. Bowen , V. M. Dwyer , I. W. Phillips , M. J. Everitt

We analytically describe the decay to equilibrium of generic observables of a non-integrable system after a perturbation in the form of a random matrix. We further obtain an analytic form for the time-averaged fluctuations of an observable…

Quantum Physics · Physics 2019-06-05 Charlie Nation , Diego Porras

We present a semiclassical calculation of the generalized form factor which characterizes the fluctuations of matrix elements of the quantum operators in the eigenbasis of the Hamiltonian of a chaotic system. Our approach is based on some…

Chaotic Dynamics · Physics 2007-05-23 M. Turek , D. Spehner , S. Müller , K. Richter

We apply a numerical method based on multi-configurational Ehrenfest tra jectories, and demonstrate converged results for the Choi fidelity of an entangling quantum gate between two two-level systems interacting through a set of bosonic…

Quantum Physics · Physics 2015-06-04 Sai-Yun Ye , Dmitrii Shalashilin , Alessio Serafini

In previous works, we introduced a geometric route to define our Ehrenfest Statistical Dynamics (ESD) and we proved that, for a simple toy-model, the resulting ESD does not preserve purity. We now take a step further: we investigate…

In this paper the feasibility of funnel control techniques for the Fokker-Planck equation corresponding to a multi-dimensional Ornstein-Uhlenbeck process on an unbounded spatial domain is explored. First, using weighted Lebesgue and Sobolev…

Optimization and Control · Mathematics 2021-04-15 Thomas Berger

We propose a prescription to quantize classical monomials in terms of symmetric and ordered expansions of non-commuting operators of a bosonic theory. As a direct application of such quantization rules, we quantize a classically time…

Quantum Physics · Physics 2016-09-08 Renato Moreira Angelo , Liliana Sanz , Kyoko Furuya

We develop a new semiclassical approach, which starts with the density matrix given by the Euclidean time path integral with fixed coinciding endpoints, and proceed by identifying classical (minimal Euclidean action) path, to be referred to…

High Energy Physics - Theory · Physics 2016-06-01 M. A. Escobar-Ruiz , E. Shuryak , A. V. Turbiner

We study the GENERIC (General Equation for Non-Equilibrium Reversible Irreversible Coupling) formulation of the nonlinear Vlasov-Fokker-Planck equation from the perspective of gradient flows along trajectories. After pulling back the…

Analysis of PDEs · Mathematics 2026-04-20 Zhenxin Liu , Xuewei Wang

A semiclassical Bohr-Sommerfeld approximation is derived for an N-particle, two-mode Bose-Hubbard system modeling a Bose-Einstein condensate in a double-well potential. This semiclassical description is based on the `classical' dynamics of…

Quantum Physics · Physics 2009-11-13 E. -M. Graefe , H. J. Korsch

We introduce a simple ansatz for the wavefunction of a many-body system based on coupled forward and backward-propagating semiclassical trajectories. This method is primarily aimed at, but not limited to, treating nonequilibrium dynamics in…

Chemical Physics · Physics 2018-05-01 Shunsuke A. Sato , Aaron Kelly , Angel Rubio

We demonstrate a method which allows the stochastic modelling of quantum systems for which the generalised Fokker-Planck equation in the phase space contains derivatives of higher than second order. This generalises quantum stochastics far…

Quantum Physics · Physics 2009-11-07 L. I. Plimak , M. K. Olsen , M. Fleischhauer , M. J. Collett