Continuous-variable quantum battery with wireless andremote charging

Quantum battery has become one of the hot issues at the research frontiers of quantum physics recently. Charging power, ergotropy and wireless charging over long-distance are three important aspects of interest. The electromagnetic interaction provides an important avenue for wireless charging. In this paper, we design a wireless and remote charging scheme based on the quantized Hamiltonian of two coupled LC circuits and investigate the charging dynamics of a continuous variable quantum battery. It is found that the battery can obtain more ergotropy only when its characteristic frequency is larger than that of the charger under rotating wave coupling. The quantum coherence is more significant than the quantum entanglement for the ergotropy of the quantum battery, regardless of whether the interaction between the charger and the battery is rotating or counter-rotating wave coupling. The feasibility of enabling the battery to extract ergotropy from the thermal reservoir through interplay between the charger and the environment is demonstrated when the roles of the rotating and counter-rotating wave couplings are considered simultaneously. Our wireless charging scheme is not only simple and cost-effective but also offers a longer charging distance than existing qubit batteries.