# Dissipative charging of a quantum battery

## TL;DR

This paper demonstrates how cyclic unitary processes can extract work from equilibrium states of engineered quantum dissipative systems, effectively charging quantum batteries with considerations of thermodynamic costs and efficiencies.

## Contribution

It introduces a method to use dissipative quantum processes for charging quantum batteries, highlighting the thermodynamic costs and optimal conditions for work extraction.

## Key findings

- Work can be cyclically extracted from equilibrium states of dissipative quantum systems.
- The process imposes a work cost according to the second law of thermodynamics.
- Certain configurations maximize work extraction and efficiency.

## Abstract

We show that a cyclic unitary process can extract work from the thermodynamic equilibrium state of an engineered quantum dissipative process. Systems in the equilibrium states of these processes serve as batteries, storing energy. The dissipative process that brings the battery to the active equilibrium state is driven by an agent that couples the battery to thermal systems. The second law of thermodynamics imposes a work cost for the process; however, no work is needed to keep the battery in that charged state. We consider simple examples of these batteries and discuss particular cases in which the extracted work or the efficiency of the process is maximal.