Quantum advantage bounds for a multipartite Gaussian battery

TL;DR

This paper establishes analytical bounds and numerical evidence for quantum advantage in the efficiency of Gaussian quantum batteries, highlighting the roles of classical squeezing, quantum squeezing, and entanglement.

Contribution

It introduces a model of multipartite Gaussian batteries with analytical bounds that differentiate classical and quantum regimes, demonstrating genuine quantum advantage.

Findings

Analytical bounds distinguish classical and quantum efficiency regimes

Numerical simulations show hierarchy in thermodynamic efficiency

Genuine quantum advantage is supported by the model and simulations

Abstract

We demonstrate the possibility of a genuine quantum advantage in the efficiency of quantum batteries by analyzing a model that enables a consistent comparison between quantum and classical regimes. Our system consists of $N$ harmonic oscillator cells coupled to a common thermal reservoir, evolving through Gaussian states. We define the global efficiency as the ratio of extractable work (ergotropy) to stored energy, and derive analytical bounds that distinguish, in order of increasing efficiency, regimes characterized by classical squeezing, quantum squeezing without entanglement, and genuine entanglement. Moreover, numerical simulations support the emergence of a similar hierarchy for the thermodynamic efficiency, defined as the ratio between ergotropy and the total thermodynamic cost of the charging process.