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arXiv · 1802.05812

Minimal dissipation model for bipartite quantum systems at finite temperature

Alexander Ramírez Bolaños·Héctor J. G. Moreno Carrión·Thomas Gorin
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Abstract

We consider the reduced dynamics in a bipartite quantum system (consisting of a central system and an intermediate environment) coupled to a heat bath at finite temperature. To describe this situation, in the simplest possible -- yet physically meaningful way, we introduce the "depolarizing heat bath" as a new minimal dissipation model. We conjecture that at sufficiently strong dissipation, any other dissipation model implemented in the form of a Markovian quantum master equation will yield the same reduced dynamics of the central system, as the minimal model. To support this conjecture, we study a two-level system coupled to an oscillator mode. For the coupling between the two parts, we consider the Jaynes-Cummings or a dephasing coupling, while the coupling to the heat bath is modeled by the quantum optical or the Caldeira-Leggett master equation (neglecting any direct coupling between central system and heat bath). We then provide ample numerical evidence, for both, model-independence and accuracy of the depolarizing heat bath model. Alongside with our study, we investigate different regimes, where the strong coupling condition leads to coherence and/or population stabilization.

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Alexander Ramírez Bolaños, Héctor J. G. Moreno Carrión, Thomas Gorin. 2018-05-11. Minimal dissipation model for bipartite quantum systems at finite temperature. https://doi.org/10.1103/physreva.98.013852

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