Efficiency fluctuations in a quantum battery charged by a repeated interaction process

TL;DR

This paper investigates the efficiency fluctuations of a quantum battery charged through a repeated interaction process with thermal systems, highlighting the role of equilibrium states and ergotropy in the charging cycle.

Contribution

It introduces a detailed analysis of efficiency fluctuations in a quantum battery charged via repeated interactions, emphasizing the influence of equilibrium states and weak dependence on process parameters.

Findings

Efficiency fluctuations are dominated by the equilibrium distribution.

Fluctuations depend weakly on process properties.

The charged state is characterized by ergotropy.

Abstract

A repeated interaction process assisted by auxiliary thermal systems charges a quantum battery. The charging energy is supplied by switching on and off the interaction between the battery and the thermal systems. The charged state is an equilibrium state for the repeated interaction process, and the ergotropy characterizes its charge. The working cycle consists in extracting the ergotropy and charging the battery again. We discuss the fluctuating efficiency of the process, among other fluctuating properties. These fluctuations are dominated by the equilibrium distribution and depend weakly on other process properties.