Thermodynamics of coupled time crystals with an application to energy storage

TL;DR

This paper investigates the thermodynamics and fluctuations of coupled boundary time crystals, revealing their correlation structures and demonstrating their potential as efficient quantum batteries for energy storage.

Contribution

It provides the first comprehensive thermodynamic analysis of coupled time crystals and explores their application in quantum energy storage.

Findings

Coupled time crystals exhibit both quantum and classical correlations.

The thermodynamic behavior of coupled time crystals is fully characterized.

Time crystals can be effectively used as quantum batteries for energy storage.

Abstract

Open many-body quantum systems can exhibit intriguing nonequilibrium phases of matter, such as time crystals. In these phases, the state of the system spontaneously breaks the time-translation symmetry of the dynamical generator, which typically manifests through persistent oscillations of an order parameter. A paradigmatic model displaying such a symmetry breaking is the boundary time crystal, which has been extensively analyzed experimentally and theoretically. Despite the broad interest in these nonequilibrium phases, their thermodynamics and their fluctuating behavior remain largely unexplored, in particular for the case of coupled time crystals. In this work, we consider two interacting boundary time crystals and derive a consistent interpretation of their thermodynamic behavior. We fully characterize their average dynamics and the behavior of their quantum fluctuations, which allows us to demonstrate the presence of quantum and classical correlations in both the stationary and the time-crystal phases displayed by the system. We furthermore exploit our theoretical derivation to explore possible applications of time crystals as quantum batteries, demonstrating their ability to efficiently store energy.