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

• URL: http://arxiv.org/abs/2204.00599v1
• Date: Fri, 1 Apr 2022 17:43:57 GMT
• Title: Hamiltonian of mean force in the weak-coupling and high-temperature approximations and refined quantum master equations
• Authors: Grigorii Timofeev and Anton Trushechkin
• Abstract summary: Hamiltonian of mean force is a widely used concept to describe the modification of the usual canonical Gibbs state for a quantum system. We numerically analyse the accuracy of the corresponding expressions and show that the precision of the Bloch-Redfield equantum master equation can be improved.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• 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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