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Related papers: Ehrenfest approach to open double-well dynamics

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Ehrenfest Dynamics combined with real-time time-dependent density functional theory has proven to be a reliable tool to study non-adiabatic molecular dynamics with a reasonable computational cost. Among other possibilities, it allows for…

Materials Science · Physics 2023-01-05 Ronaldo Rodrigues Pela , Claudia Draxl

We describe a study motivated by our interest to examine the incompleteness of the Ehrenfest's theorem in quantum mechanics and to resolve a doubt regarding whether or not the hermiticity of the hamiltonian operator is sufficient to justify…

Quantum Physics · Physics 2021-10-22 Domenico Giordano , Pierluigi Amodio

In a quantum charge pump, the periodic variation of two parameters that affect the phase of the electronic wavefunction causes the flow of a direct current. The operating mechanism of a quantum pump is based on quantum interference, the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Saar Rahav , Piet W. Brouwer

Many advanced quantum techniques feature non-Gaussian dynamics, and the ability to manipulate the system in that domain is the next-stage in many experiments. One example of meaningful non-Gaussian dynamics is that of a double-well…

Two classical stochastic processes are considered, the Ehrenfest process, introduced in 1907 in the kinetic theory of gases to describe the heat exchange between two bodies and the Engset process, one of the early (1918) stochastic models…

Probability · Mathematics 2011-09-02 Mathieu Feuillet , Philippe Robert

Ehrenfest dynamics is a useful approximation for ab initio mixed quantum-classical molecular dynamics that can treat electronically nonadiabatic effects. Although a severe approximation to the exact solution of the molecular time-dependent…

Chemical Physics · Physics 2021-09-24 Seonghoon Choi , Jiří Vaníček

Linear and nonlinear electronic spectra provide an important tool to probe the absorption and transfer of electronic energy. Here we introduce a pure state Ehrenfest approach to obtain accurate linear and nonlinear spectra that is…

Chemical Physics · Physics 2022-12-15 Austin O. Atsango , Andrés Montoya-Castillo , Thomas E. Markland

By using numerical and semiclassical methods, we evaluate the quantum breaking, or Ehrenfest time for a wave packet localized around classical equilibrium points of autonomous one-dimensional systems with polynomial potentials. We find that…

Quantum Physics · Physics 2009-11-07 Fabrizio Cametti , Carlo Presilla

Quantum thermodynamics aims to explore quantum features to enhance energy conversion beyond classical limits. While significant progress has been made, the understanding of caloric potentials in quantum systems remains incomplete. In this…

Quantum Physics · Physics 2025-02-27 Clebson Cruz , J. S. Amaral , Mario Reis

The usual paradigm of open quantum systems falls short when the environment is actually coupled to additional fields or components that drive it out of equilibrium. Here we explore the simplest such scenario, by considering a two level…

Quantum Physics · Physics 2020-09-08 Andreu Anglés-Castillo , Mari Carmen Bañuls , Armando Pérez , Inés De Vega

We describe vacuum fluctuations and photon-field correlations in interacting quantum mechanical light-matter systems, by generalizing the application of mixed quantum-classical dynamics techniques. We employ the multi-trajectory…

Quantum Physics · Physics 2019-06-26 Norah M. Hoffmann , Christian Schäfer , Angel Rubio , Aaron Kelly , Heiko Appel

We analytically demonstrate the emergence of surface non-Hermitian boundary contributions that appear in an extended form of the quantum Ehrenfest theorem and are crucial (although so far overlooked) in the calculation of optical matrix…

Mesoscale and Nanoscale Physics · Physics 2018-07-30 Georgios Konstantinou , Konstantinos Moulopoulos

Treated traditionally by the Ehrenfest approximation, dynamics of a one-dimensional molecular crystal model with off-diagonal exciton-phonon coupling is investigated in this work using the Dirac-Frenkel time-dependent variational principle…

Chemical Physics · Physics 2017-04-25 Zhongkai Huang , Lu Wang , Changqin Wu , Lipeng Chen , Frank Grossmann , Yang Zhao

Far out-of-equilibrium many-body quantum dynamics in isolated systems necessarily generate interferences beyond an Ehrenfest time scale, where quantum and classical expectation values diverge. Of great recent interest is the role these…

Quantum Physics · Physics 2018-06-20 Steven Tomsovic , Peter Schlagheck , Denis Ullmo , Juan Diego Urbina , Klaus Richter

We generalize Ehrenfest's equations to systems having two work terms, i.e. systems with three degrees of freedom. For black holes with two work terms we obtain nine equations instead of two to be satisfied at the critical point of a second…

General Relativity and Quantum Cosmology · Physics 2015-03-10 Mohammad Bagher Jahani Poshteh , Behrouz Mirza , Fatemeh Oboudiat

The thawed Gaussian Ehrenfest dynamics is a single-trajectory method that partially includes both nuclear quantum and electronically nonadiabatic effects by combining the thawed Gaussian wavepacket dynamics with Ehrenfest dynamics. First,…

Chemical Physics · Physics 2025-04-09 Alan Scheidegger , Jiří J. L. Vaníček

Known force terms arising in the Ehrenfest dynamics of quantum electrons and classical nuclei, due to a moving basis set for the former, can be understood in terms of the curvature of the manifold hosting the quantum states of the…

Other Condensed Matter · Physics 2022-01-19 Jessica F. K. Halliday , Emilio Artacho

We unravel the existence and nonequilibrium response of one-dimensional harmonically trapped droplet configurations in the presence of a central potential barrier or well. For fixed negative chemical potentials, it is shown that droplets…

Quantum Gases · Physics 2025-11-26 F. Bristy , G. A. Bougas , G. C. Katsimiga , S. I. Mistakidis

We discuss the possibility of realizing a non-Hermitian, i.e. an open two-well system of ultra-cold atoms by enclosing it with additional time-dependent wells that serve as particle reservoirs. With the appropriate design of the additional…

Quantum Physics · Physics 2014-11-20 Manuel Kreibich , Jörg Main , Holger Cartarius , Günter Wunner

Applying the theory of self-adjoint extensions of Hermitian operators to Koopman von Neumann classical mechanics, the most general set of probability distributions is found for which entropy is conserved by Hamiltonian evolution. A new…

Statistical Mechanics · Physics 2019-06-24 Gerard McCaul , Alexander Pechen , Denys I. Bondar