Entanglement and steering in quantum batteries

The advantage of quantum batteries is that quantum resources can be used to improve charging efficiency. The quantum resources that are known to be available are: quantum entanglement and quantum coherence. In this paper, we introduce quantum steering as a new quantum resource into batteries for the first time. We analyze the relationship between quantum steering, quantum entanglement, energy storage, and extractable work by considering two models: Field-quantum battery and Cavity-Heisenberg quantum battery. We find that in the steerable range, the quantum steering of different qubits has a maximum or minimum value, which corresponds to the energy storage of the battery, and the extractable work has a maximum value. The occurrence of the minimum value of quantum entanglement is always accompanied by the occurrence of the maximum value of parameters such as energy storage. Ultimately, we analyzed the reasons for these results using the purity of the system. And found a relatively general conclusion: when the purity is at the maximum, important parameters such as the energy storage of the battery are also at the maximum.