Entanglement and Steering in Quantum Batteries

Abstract The advantage of quantum batteries is that quantum resources can be utilized to enhance charging efficiency. The known available quantum resources are quantum entanglement and quantum coherence. In this study, quantum steering is introduced as a new quantum resource into batteries for the first time. By considering two models, namely the Field‐quantum battery and the Cavity–Heisenberg quantum battery, the relationship is analyzed among quantum steering, quantum entanglement, energy storage, and extractable work. It is found that within the steerable range, the quantum steering of different qubits has a maximum or minimum value, which corresponds to the energy storage of the battery. Moreover, this maximum or minimum value of quantum steering also corresponds to the maximum value of the extractable work. The minimum of quantum entanglement always coincides with the maximum of parameters like energy storage. Ultimately, the reasons for these results are analyzed by analyzing the purity of the system and discover a relatively general conclusion: when the purity is at its maximum, important parameters such as the energy storage of the battery are also at their maximum.