



01237nas a2200145   4500008004100000245008300041210006900124260001400193490000800207520076500215100003200980700002001012700002201032856003701054       2020                        eng d00aFluctuations in Extractable Work Bound the Charging Power of Quantum Batteries0 aFluctuations in Extractable Work Bound the Charging Power of Qua  c7/22/20200 v1253 a<p>We study the connection between the charging power of quantum batteries and the fluctuations of the stored 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 `\emph{work operator}&#39;, defined by F &equiv; HW + β&minus;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 stored work 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.&nbsp;</p>1 aGarcía-Pintos, Luis, Pedro1 aHamma, Alioscia1 adel Campo, Adolfo  uhttps://arxiv.org/abs/1909.03558