Hybrid quantum-classical dynamics with stationary thermal states
Phys. Rev. E 114, 024125 – Published 13 August, 2026
DOI: https://doi.org/10.1103/3vh7-cjcs
Abstract
Quantum and classical systems can consistently be coupled via nonunitary time-irreversible mechanisms. In this paper, we characterize which kind of corresponding dynamics converge in the stationary regime to a thermal hybrid state, that is, a density matrix that maximizes the hybrid arrangement entropy under the constraints of a canonical ensemble. Introducing a detailed balance condition, it is found that a specific subclass of hybrid Lindblad equations fulfill the demanded requirement. The main theoretical results are exemplified through a set of specific dynamics that in addition enlighten how the thermal state of each subsystem in isolation is affected by their mutual coupling. In particular, a Gaussian thermal state could become a bimodal distribution when increasing the interaction strength of a classical subsystem with a quantum two-level subsystem.