The presence of quantum correlations result in non-vanishing ergotropic gap

TL;DR

This paper investigates how quantum correlations influence the non-zero ergotropic gap, a thermodynamic measure of work extractable from quantum systems, highlighting its quantification and implications in multi-party scenarios.

Contribution

It introduces a detailed analysis of the ergotropic gap in multi-party quantum states and explores its relation to quantum correlations and thermal contact.

Findings

Quantum correlations lead to a non-zero ergotropic gap.

The ergotropic gap can be quantified for arbitrary multi-party states.

The difference between global and local work extraction is evaluated with thermal baths.

Abstract

The paradigm of extracting work from isolated quantum system through a cyclic Hamiltonian process is a topic of immense research interest. The optimal work extracted under such process is termed as ergotropy [Europhys. Lett., 67 (4), 565(2004)]. Here, in a multi-party scenario we consider only a class of such cyclic processes that can be implemented locally, giving rise to the concept of local ergotropy. Eventually, presence of quantum correlations result in a non-vanishing thermodynamic quantity called ergotropic gap, measured by the difference between the global and local ergotropy. However the converse does not hold in general, i.e. its nonzero value does not necessarily imply presence of quantum correlations. For arbitrary multi-party states we quantify this gap. We also evaluate the difference between maximum global and local extractable work for arbitrary states when the system is no longer isolated but put in contact with a baths of same local temperature.