AUTHOR=Zhang Xiang , Blaauboer Miriam 

TITLE=Enhanced energy transfer in a Dicke quantum battery

JOURNAL=Frontiers in Physics

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.1097564

DOI=10.3389/fphy.2022.1097564

ISSN=2296-424X

ABSTRACT=<p>We theoretically investigate the enhancement of the charging power in a Dicke quantum battery which consists of an array of <italic>N</italic> two-level systems (TLS)coupled to a single mode of cavity photons. In the limit of small <italic>N</italic>, 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 <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msqrt></mml:math></inline-formula> 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.</p>