Ultra-stable charging of fast-scrambling SYK quantum batteries

TL;DR

This paper demonstrates that using a SYK quench Hamiltonian for charging quantum batteries results in highly stable energy storage due to nonlocal correlations and fast thermalization, outperforming other models in stability.

Contribution

Introduces a unitary charging protocol based on the SYK model, showing enhanced stability and suppressed fluctuations in quantum batteries due to nonlocal correlations and fast scrambling.

Findings

Energy stored in SYK-based QB is highly stable.

Temporal fluctuations are strongly suppressed by nonlocal correlations.

Fast scrambling property promotes temporal stability of quantum batteries.

Abstract

Collective behavior strongly influences the charging dynamics of quantum batteries (QBs). Here, we study the impact of nonlocal correlations on the energy stored in a system of $N$ QBs. A unitary charging protocol based on a Sachdev-Ye-Kitaev (SYK) quench Hamiltonian is thus introduced and analyzed. SYK models describe strongly interacting systems with nonlocal correlations and fast thermalization properties. Here, we demonstrate that, once charged, the average energy stored in the QB is very stable, realizing an ultraprecise charging protocol. By studying fluctuations of the average energy stored, we show that temporal fluctuations are strongly suppressed by the presence of nonlocal correlations at all time scales. A comparison with other paradigmatic examples of many-body QBs shows that this is linked to the collective dynamics of the SYK model and its high level of entanglement. We argue that such feature relies on the fast scrambling property of the SYK Hamiltonian, and on its fast thermalization properties, promoting this as an ideal model for the ultimate temporal stability of a generic QB. Finally, we show that the temporal evolution of the ergotropy, a quantity that characterizes the amount of extractable work from a QB, can be a useful probe to infer the thermalization properties of a many-body quantum system.