Strong Coupling Thermodynamics of Open Quantum Systems

TL;DR

This paper develops a comprehensive thermodynamic framework for open quantum systems that applies across all coupling strengths, including strong and weak regimes, and introduces a signature of non-Markovianity via entropy production.

Contribution

It presents a unified thermodynamic approach for open quantum systems with arbitrary coupling, incorporating initial correlations and linking measurable system observables to thermodynamic properties.

Findings

Thermodynamic laws are valid for all coupling strengths.

A negative entropy production rate indicates non-Markovian behavior.

Thermodynamic quantities can be inferred from system measurements.

Abstract

A general thermodynamic framework is presented for open quantum systems in fixed contact with a thermal reservoir. The first and second law are obtained for arbitrary system-reservoir coupling strengths, and including both factorized and correlated initial conditions. The thermodynamic properties are adapted to the generally strong coupling regime, approaching the ones defined for equilibrium, and their standard weak-coupling counterparts as appropriate limits. Moreover, they can be inferred from measurements involving only system observables. Finally, a thermodynamic signature of non-Markovianity is formulated in the form of a negative entropy production rate.