Improving quantum-battery lifetime by the electromagnetically-induced-transparency effect and bound states

Quantum battery (QB) is an application of quantum thermodynamics which uses quantum effects to store and transfer energy, overcoming the limitations of classical batteries and potentially improving the QB's performance. However, due to the interaction with the external environment, it leads to decoherence and thus reduces both the lifetime and the charging efficiency of QB. Here, we propose suppressing the environmental dissipation in the energy-storage process of the QB by exploiting both the electromagnetically-induced-transparency (EIT) effect and bound states. By constructing a hybrid system composed of a four-level atom and a coupled-cavity array, two bound states are formed in the system when the energy of the QB is in the energy band of the cavity array. Environmental dissipation is significantly inhibited due to the bound state and EIT effects, which extends the lifetime of the QB. We show that the charging efficiency of the QB is optimal when the energy of the QB is in resonance with the cavity. In addition, there is an optimal coupling strength between the two adjacent cavities, which helps to improve the performance of the QB. Our research has achieved the realization of long-term energy storage while improving the charging efficiency of QB, which has practical implications for the realization of QB.