Coherence-Enhanced Quantum Battery Charging with Ergotropy Stabilization

TL;DR

This paper introduces a dual-channel coherence framework for quantum batteries, demonstrating how internal and external coherence sources can synergistically enhance and stabilize ergotropy and charging power.

Contribution

It pioneers the investigation of combining internal charger coherence with reservoir squeezing to improve quantum battery performance.

Findings

Internal charger coherence and reservoir squeezing jointly boost transient charging power.

Initial charger coherence is key to maximizing and stabilizing steady-state ergotropy.

Local battery coherence builds up from combined internal and external coherence sources.

Abstract

Quantum batteries utilize nonclassical resources to achieve charging speed and energy storage performances that surpass classical thermodynamic limits. However, the practical realization of quantum batteries is often constrained by the inevitable environment-induced dissipation of both stored ergotropy and coherence. To actively counteract these losses, we propose a dual-channel coherence framework that exploits dark-state protection to stabilize ergotropy. We conduct, for the first time, an investigation of the synergistic interplay between internal charger coherence and reservoir squeezing, the latter acting as a source of external coherence. In the resource-efficient regime where charger and battery sizes are comparable, our study shows that internal charger coherence and reservoir squeezing jointly enhance the transient charging power. Crucially, initial charger coherence is the fundamental resource for maximizing and stabilizing steady-state ergotropy through dark-state protection. Our analysis reveals that these advantages are driven by the buildup of local battery coherence, which emerges from the integration of both internal and external coherence sources. These results offer a robust pathway for high-power, stabilized energy storage in quantum architectures.