2019/09/30 by Luis Pedro García-Pintos, Alioscia Hamma, Adolfo del Campo · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.125.040601
published as Phys. Rev. Lett. 125, 040601 (2020) · Accepted version with updated presentation and references. main: 5 pages, 2 figures; PRL response: 1 page; appendix: 5 pages, 3 figures. Includes our Reply to a Comment by Cusumano and Rudnicki, both published in Phys. Rev. Lett
arxiv created 2021/07/09 · arxiv updated 2021/07/12
We study the connection between the charging power of quantum batteries and the fluctuations of the extractable work. We prove that in order to have a non-zero rate of change of the extractable work, the state ρW of the battery cannot be an eigenstate of a `free energy operator', defined by F~≡~HW~+~β-1log(ρW), where HW is the Hamiltonian of the battery and β is the inverse temperature of a reference thermal bath with respect to which the extractable work is calculated. We do so by proving that fluctuations in the free energy operator upper bound the charging power of a quantum battery. Our findings also suggest that quantum coherence in the battery enhances the charging process, which we illustrate on a toy model of a heat engine. Note: this version includes our Reply to a Comment by Cusumano and Rudnicki, both published in Phys. Rev. Lett.