Extractable Work from Correlations

TL;DR

This paper investigates how quantum correlations can be exploited to maximize work extraction in quantum systems, revealing that entanglement offers advantages in small ensembles but not in large ones.

Contribution

It provides a comprehensive analysis of the maximum extractable work from correlated quantum systems, including entangled and separable states, under various conditions.

Findings

Entanglement enhances work extraction in small quantum ensembles.

The advantage of entanglement diminishes as the number of systems increases.

States with fixed entropy have specific bounds on extractable work.

Abstract

Work and quantum correlations are two fundamental resources in thermodynamics and quantum information theory. In this work we study how to use correlations among quantum systems to optimally store work. We analyse this question for isolated quantum ensembles, where the work can be naturally divided into two contributions: a local contribution from each system, and a global contribution originating from correlations among systems. We focus on the latter and consider quantum systems which are locally thermal, thus from which any extractable work can only come from correlations. We compute the maximum extractable work for general entangled states, separable states, and states with fixed entropy. Our results show that while entanglement gives an advantage for small quantum ensembles, this gain vanishes for a large number of systems.