Quantacell: Powerful charging of quantum batteries

TL;DR

This paper presents an analytical and numerical study of quantum battery charging, demonstrating a quantum advantage in power when using global operations on multiple qubits, with potential implications for quantum energy storage.

Contribution

It introduces an optimal charging protocol for a single qubit and extends the analysis to multiple qubits, revealing an N-fold power advantage with global operations.

Findings

Analytical optimal protocol for single-qubit charging.

Demonstration of N-fold power advantage with N qubits.

Quantum advantage persists with separable initial and final states.

Abstract

We study the problem of charging a quantum battery in finite time. We demonstrate an analytical optimal protocol for the case of a single qubit. Extending this analysis to an array of N qubits, we demonstrate that an N-fold advantage in power per qubit can be achieved when global operations are permitted. The exemplary analytic argument for this quantum advantage in the charging power is backed up by numerical analysis using optimal control techniques. It is demonstrated that the quantum advantage for power holds when, with cyclic operation in mind, initial and final states are required to be separable.