Enhancing the charging power of quantum batteries

TL;DR

This paper investigates how collective quantum effects can enhance the charging power of quantum batteries, deriving bounds on quantum advantage and emphasizing the role of entanglement and interaction order.

Contribution

It provides the first analytic bounds on quantum advantage in charging power, highlighting the importance of entanglement and interaction constraints in quantum battery performance.

Findings

Quantum advantage in charging power can be bounded analytically.

Entanglement is essential for achieving quantum advantage.

Interaction order limits the maximum quantum advantage.

Abstract

Can collective quantum effects make a difference in a meaningful thermodynamic operation? Focusing on energy storage and batteries, we demonstrate that quantum mechanics can lead to an enhancement in the amount of work deposited per unit time, i.e., the charging power, when $N$ batteries are charged collectively. We first derive analytic upper bounds for the collective \emph{quantum advantage} in charging power for two choices of constraints on the charging Hamiltonian. We then highlight the importance of entanglement by proving that the quantum advantage vanishes when the collective state of the batteries is restricted to be in the separable ball. Finally, we provide an upper bound to the achievable quantum advantage when the interaction order is restricted, i.e., at most $k$ batteries are interacting. Our result is a fundamental limit on the advantage offered by quantum technologies over their classical counterparts as far as energy deposition is concerned.