Performance of a Superconducting Quantum Battery

Finding a quantum battery model that demonstrates a quantum advantage while remaining feasible for experimental production is a considerable challenge. In this paper, we introduce a superconducting quantum battery (SQB) model that exhibits such an advantage. The model consists of two coupled superconducting qubits that interact during the unitary charging process while remaining in equilibrium with a thermal reservoir. We first describe the model, provide evidence of the quantum advantage, and then discuss the fabrication process of the battery using superconducting qubits. Importantly, we derive analytical expressions for the ergotropy, instantaneous power, and capacity of the SQB, as well as their connection to quantum coherence. We demonstrate that leveraging the collective effects of Josephson energies and the coupling energy between qubits allows for optimization, resulting in improved energy redistribution and a significant enhancement in charging efficiency. This work highlights the complexities of tuning system parameters, which increase the potential for work extraction from the quantum battery, thereby providing a deeper understanding of the charging mechanisms involved. These findings can be applied to superconducting quantum circuit battery architectures, underscoring the feasibility of efficient energy storage in these systems. Our results pave the way for proposals of new superconducting devices capable of storing extractable work, emphasizing their potential for efficient energy storage.
Comment: 12 pages, 5 figures