Quick charging of a quantum battery with superposed trajecotries

TL;DR

This paper introduces quantum superposition-based charging protocols for quantum batteries, demonstrating that interference effects can significantly accelerate charging and increase extractable work, validated through experiments on IBMQ and IonQ.

Contribution

The paper presents novel quantum superposition protocols for charging batteries, showing enhanced ergotropy and faster charging via quantum interference effects, with experimental validation.

Findings

Superposition protocols increase ergotropy with more trajectories.

Two superposed trajectories suffice for maximum ergotropy.

Experimental results confirm theoretical predictions of enhanced charging.

Abstract

We propose novel charging protocols for quantum batteries based on quantum superpositions of trajectories. Specifically, we consider that a qubit (the battery) interacts with multiple cavities or a single cavity at various positions, where the cavities act as chargers. Further, we introduce a quantum control prepared in a quantum superposition state, allowing the battery to be simultaneously charged by multiple cavities or a single cavity with different entry positions. To assess the battery's performance, we evaluate the maximum extractable work, referred to as ergotropy. Our main result is that the proposed protocols can utilize quantum interference effects to speed up the charging process. For the protocol involving multiple cavities, we observe a substantial increase in ergotropy as the number of superposed trajectories increases. In the case of the single-cavity protocol, we show that two superposed trajectories (entry positions) are sufficient to achieve the upper limit of the ergotropy throughout the entire charging process. Furthermore, we propose circuit models for these charging protocols and conduct proof-of-principle demonstrations on IBMQ and IonQ quantum processors. The results validate our theoretical predictions, demonstrating a clear enhancement in ergotropy.