Quantum Batteries: Quantum Benefit and Realization

This study explores classical and quantum nanoscale energy storage, highlighting the quantum charging speed advantage driven by superposition and entanglement. Quantum Batteries (QBs), modeled as ensembles of two-level systems (TLS) capable of energy storage and extraction through unitary operations, are analyzed under various setups. Classical configurations, where TLS interact with electromagnetic fields either independently or collectively, show no speed-up. However, in a quantum scenario with a photon bath, the Dicke QB, leveraging entanglement through a shared photonic mode, achieves a quantum advantage with charging time scaling as √N, compared to the linear scaling of classical systems. The study also discusses experimental realizations, addressing energy storage, leakage, and challenges in advancing quantum battery technologies.