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arXiv · 2204.00599

Hamiltonian of mean force in the weak-coupling and high-temperature approximations and refined quantum master equations

Grigorii Timofeev·Anton Trushechkin
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Abstract

The Hamiltonian of mean force is a widely used concept to describe the modification of the usual canonical Gibbs state for a quantum system whose coupling strength with the thermal bath is non-negligible. Here we perturbatively derive general approximate expressions for the Hamiltonians of mean force in the weak-coupling approximation and in the high-temperature one. We numerically analyse the accuracy of the corresponding expressions and show that the precision of the Bloch-Redfield equantum master equation can be improved if we replace the original system Hamiltonian by the Hamiltonian of mean force.

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Grigorii Timofeev, Anton Trushechkin. 2022-04-01. Hamiltonian of mean force in the weak-coupling and high-temperature approximations and refined quantum master equations. https://doi.org/10.1142/s0217751x22430217

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