Enhanced energy transfer in a Dicke quantum battery

We theoretically investigate the enhancement of the charging power in a Dicke quantum battery which consists of an array of N two-level systems (TLS)coupled to a single mode of cavity photons. In the limit of small N, we analytically solve the time evolution for the full charging process. The eigenvectors of the driving Hamiltonian are found to be pseudo-Hermite polynomials and the evolution is thus interpreted as harmonic oscillator like behaviour. Then we demonstrate the average charging power using a collective protocol is root N times larger than that of the parallel protocol when transferring the same amount of energy. Unlike previous studies, we point out that such quantum advantage does not originate from entanglement but is due to the coherent cooperative interactions among the TLSs. Our results provide intuitive quantitative insight into the dynamic charging process of a Dicke battery and can be observed under realistic experimental conditions.

Automated summary

We theoretically investigate the enhancement of charging power in a Dicke quantum battery composed of N two-level systems (TLS) coupled to cavity photons. For small N, we analytically solve the time evolution of the charging process and find that the eigenvectors of the driving Hamiltonian are pseudo-Hermite polynomials, showing harmonic oscillator-like behavior. We demonstrate that the average charging power using a collective protocol is approximately root N times larger than that of the parallel protocol, and this quantum advantage is due to the coherent cooperative interactions among the TLSs rather than entanglement. Our results provide quantitative insight into the dynamic charging process of a Dicke battery and can be observed in realistic experimental conditions.