# Quantum battery charging by non-equilibrium steady-state currents

## TL;DR

This paper analyzes how quantum batteries can be charged using steady-state charge and heat currents, highlighting the effectiveness of charge currents in off-resonant regimes through non-equilibrium Green's function theory.

## Contribution

It introduces a model for quantum batteries as open quantum systems coupled to reservoirs and evaluates their charging performance under steady-state currents.

## Key findings

- Charge currents effectively charge quantum batteries in off-resonant regimes.
- Steady-state charge currents outperform heat currents in high bias regimes.
- Theoretical framework uses non-equilibrium Green's functions for analysis.

## Abstract

We present an analysis of the availability and maximum extractable work of quantum batteries in the presence of charge and/or heat steady-state currents. Quantum batteries are modelled as non-interacting open quantum systems (mesoscopic systems) strongly coupled to two thermal and particle reservoirs within the framework of non-equilibrium Green's function theory in a steady-state regime. We found that the battery can be charged manifestly by a steady-state charge current compared to heat one, especially, in an off-resonant transport regime. It allows us to reliably access the performance of the quantum batteries in the high bias-charging regime.