Quantum batteries in coherent Ising machine

TL;DR

This paper proposes a quantum battery based on a coherent Ising machine, demonstrating enhanced robustness against decoherence and optimal energy discharge, paving the way for experimental quantum energy storage.

Contribution

It introduces a practical quantum battery architecture using a coherent Ising machine, highlighting the role of quantum coherence in improving energy storage robustness.

Findings

Coherent ergotropy decays slower than incoherent ergotropy, indicating stronger decoherence resistance.

Maximum coherent ergotropy and charging power occur simultaneously, identifying the optimal switching time.

Efficient energy discharge demonstrated by coupling the QB to a two-level system.

Abstract

With intensive studies of quantum thermodynamics, quantum batteries (QBs) have been proposed to store and transfer energy via quantum effects. Despite many theoretical models, decoherence remains a severe challenge and practical platforms are still rare. Here, we propose a QB based on the coherent Ising machine, in which the signal field acts as the core energy-storage unit. To clarify the role of quantum coherence in resisting dissipation, we decompose the ergotropy, i.e., the maximum extractable work from the QB, into its coherent and incoherent components. We find that the coherent part decays at a rate roughly half that of the incoherent part, exhibiting much stronger robustness against decoherence. More importantly, the coherent ergotropy and the average charging power reach their respective maxima at essentially the same moment, which defines the optimal instant to switch off the pump field. Finally, by coupling the QB to a two-level system as the load, we demonstrate an efficient energy discharge process of the proposed QB. Our work establishes a realistic and immediately-implementable QB architecture on a mature optical platform, laying a foundation for experimental exploration of quantum energy storage.