Work fluctuations and entanglement in quantum batteries

TL;DR

This paper links work fluctuations in quantum batteries to the presence and strength of entanglement, providing bounds and protocols to detect entanglement dimensionality through energy fluctuation measurements.

Contribution

It introduces a hierarchy of bounds on entanglement from work fluctuations and proposes measurement protocols to estimate these fluctuations in noisy conditions.

Findings

Larger work fluctuations indicate stronger entanglement.

Derived bounds connect entanglement dimension to energy fluctuations.

Proposed measurement protocols can estimate work fluctuations with noisy detectors.

Abstract

We consider quantum batteries given by composite interacting quantum systems in terms of the thermodynamic work cost of local random unitary processes. We characterize quantum correlations by monitoring the average energy change and its fluctuations in the high-dimensional bipartite systems. We derive a hierarchy of bounds on high-dimensional entanglement (the so-called Schmidt number) from the work fluctuations and thereby show that larger work fluctuations can verify the presence of stronger entanglement in the system. Finally, we develop two-point measurement protocols with noisy detectors that can estimate work fluctuations, showing that the dimensionality of entanglement can be probed in this manner.