Quantum advantage in charging cavity and spin batteries by repeated interactions

Abstract

Recently, an unconditional advantage has been demonstrated for the process of charging of a quantum battery in a collisional model [Seah et al., Phys. Rev. Lett. 127, 100601 (2021)0031-900710.1103/PhysRevLett.127.100601]. Motivated by the question of whether such an advantage could be observed experimentally, we consider a model where the battery is described by a quantum harmonic oscillator or a large spin, charged via repeated interactions with a stream of qubit units. For both setups, we show that a quantum protocol can significantly outperform the most general adaptive classical schemes, leading to 90 and 38% higher charging power for the cavity and large spin batteries, respectively. Toward an experimental realization, we also characterize the robustness of this quantum advantage to imperfections (noise and decoherence) considering implementations with state-of-the-art micromasers and hybrid superconducting devices.