Average quantum dynamics of closed systems over stochastic Hamiltonians

Abstract We develop a formally exact master equation to describe the evolution of the average density matrix of a closed quantum system driven by a stochastic Hamiltonian. The average over stochastic processes generally results in decoherence effects in closed system dynamics, in addition to the uni...

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Main Authors: Li Yu, Daniel F. V. James
Format: Article
Language:English
Published: Nature Portfolio 2025-08-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-025-14825-z
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author Li Yu
Daniel F. V. James
author_facet Li Yu
Daniel F. V. James
author_sort Li Yu
collection DOAJ
description Abstract We develop a formally exact master equation to describe the evolution of the average density matrix of a closed quantum system driven by a stochastic Hamiltonian. The average over stochastic processes generally results in decoherence effects in closed system dynamics, in addition to the unitary evolution. We then show that, for an important class of problems in which the Hamiltonian is proportional to a Gaussian random process, the 2nd-order master equation yields exact dynamics. The general formalism is applied to study the examples of a two-level system, two atoms in a stochastic magnetic field and the heating of a trapped ion, where we find phenomena such as decoherence-induced disentanglement.
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spelling doaj-art-815c829084cb4661bbd0e3825e51d85a2025-08-24T11:17:27ZengNature PortfolioScientific Reports2045-23222025-08-0115111210.1038/s41598-025-14825-zAverage quantum dynamics of closed systems over stochastic HamiltoniansLi Yu0Daniel F. V. James1Department of Physics, University of TorontoDepartment of Physics, University of TorontoAbstract We develop a formally exact master equation to describe the evolution of the average density matrix of a closed quantum system driven by a stochastic Hamiltonian. The average over stochastic processes generally results in decoherence effects in closed system dynamics, in addition to the unitary evolution. We then show that, for an important class of problems in which the Hamiltonian is proportional to a Gaussian random process, the 2nd-order master equation yields exact dynamics. The general formalism is applied to study the examples of a two-level system, two atoms in a stochastic magnetic field and the heating of a trapped ion, where we find phenomena such as decoherence-induced disentanglement.https://doi.org/10.1038/s41598-025-14825-z
spellingShingle Li Yu
Daniel F. V. James
Average quantum dynamics of closed systems over stochastic Hamiltonians
Scientific Reports
title Average quantum dynamics of closed systems over stochastic Hamiltonians
title_full Average quantum dynamics of closed systems over stochastic Hamiltonians
title_fullStr Average quantum dynamics of closed systems over stochastic Hamiltonians
title_full_unstemmed Average quantum dynamics of closed systems over stochastic Hamiltonians
title_short Average quantum dynamics of closed systems over stochastic Hamiltonians
title_sort average quantum dynamics of closed systems over stochastic hamiltonians
url https://doi.org/10.1038/s41598-025-14825-z
work_keys_str_mv AT liyu averagequantumdynamicsofclosedsystemsoverstochastichamiltonians
AT danielfvjames averagequantumdynamicsofclosedsystemsoverstochastichamiltonians