From quantum heat engines to laser cooling: Floquet theory beyond the Born-Markov approximation

TL;DR

This paper develops a theoretical framework combining Floquet theory and full counting statistics to analyze the thermodynamics of a periodically driven quantum heat engine beyond the Born-Markov approximation, revealing diverse operational regimes and connections to laser cooling.

Contribution

It introduces a novel approach integrating Floquet theory with full counting statistics and Markovian embedding to study quantum thermal machines beyond standard approximations.

Findings

Identifies four operational regimes including heat engine and refrigerator.

Shows how increasing bath coupling affects efficiency and regimes.

Reproduces laser cooling setup in a specific parameter limit.

Abstract

We combine the formalisms of Floquet theory and full counting statistics with a Markovian embedding strategy to access the dynamics and thermodynamics of a periodically driven thermal machine beyond the conventional Born-Markov approximation. The working medium is a two-level system and we drive the tunneling as well as the coupling to one bath with the same period. We identify four different operating regimes of our machine which include a heat engine and a refrigerator. As the coupling strength with one bath is increased, the refrigerator regime disappears, the heat engine regime narrows and their efficiency and coefficient of performance decrease. Furthermore, our model can reproduce the setup of laser cooling of trapped ions in a specific parameter limit.