Ergotropy from quantum and classical correlations

TL;DR

This paper investigates how both quantum and classical correlations, including entanglement, contribute to the extractable thermodynamic work (ergotropy) in bipartite quantum systems, highlighting the role of mutual information.

Contribution

It expresses ergotropy as a function of quantum mutual information, linking extractable work to correlations, and analyzes bipartite systems with locally thermal states.

Findings

Ergotropy can be decomposed into contributions from classical and quantum correlations.

The analysis shows correlations are sufficient for work extraction in locally thermal states.

Illustrations with a two-qubit system demonstrate the theoretical findings.

Abstract

It is an established fact that quantum coherences have thermodynamic value. The natural question arises, whether other genuine quantum properties such as entanglement can also be exploited to extract thermodynamic work. In the present analysis, we show that the ergotropy can be expressed as a function of the quantum mutual information, which demonstrates the contributions to the extractable work from classical and quantum correlations. More specifically, we analyze bipartite quantum systems with locally thermal states, such that the only contribution to the ergotropy originates in the correlations. Our findings are illustrated for a two-qubit system collectively coupled to a thermal bath.