Optimal charging of open spin-chain quantum batteries via homodyne-based feedback control

TL;DR

This paper investigates how homodyne-based feedback control can optimize the charging process of dissipative spin-chain quantum batteries, improving energy storage and extraction efficiency under various conditions.

Contribution

It introduces a feedback control scheme based on homodyne measurement to enhance quantum battery performance, with analytical and numerical validation for different system sizes.

Findings

Optimal parameters enable full charging and energy extraction at zero temperature.

Feedback control improves energy storage and ergotropy.

Imperfect measurement and finite temperature negatively impact charging efficiency.

Abstract

We study the problem of charging a dissipative one-dimensional $XXX$ spin-chain quantum battery using local magnetic fields in the presence of spin decay. The introduction of quantum feedback control based on homodyne measurement contributes to improve various performance of the quantum battery, such as energy storage, ergotropy, and effective space utilization rate. For the zero temperature environment, there is a set of optimal parameters to ensure that the spin-chain quantum battery can be fully charged and the energy stored in the battery can be fully extracted under the perfect measurement condition, which is found through the analytical calculation of a simple two-site spin-chain quantum battery and further verified by numerical simulation of a four-site spin-chain counterpart. For completeness, the adverse effects of imperfect measurement, anisotropic parameter, and finite temperature on the charging process of the quantum battery are also considered.