Speaker
Description
The local ergotropy, the maximum amount of work extractable via local unitary transformations, is theoretically investigated in an out-of-equilibrium localized many-body quantum battery. In this analysis, we focus on the one-dimensional disordered XXZ Heisenberg model. Extensive simulations are conducted to model the dynamics using matrix product states and to optimise unitary transformations discharging the subsystem made of two spins. A comparison between local and switch-off ergotropy behaviour is presented for ergodic, Anderson and many-body localized phases. Analysing several chain lengths, spin couplings and disorder strengths, it is observed that the extractable work is much larger for localized than for ergodic phases from short up to long times. Moreover, signatures for localization phenomena are identified through quantum thermodynamic quantities, such as the local ergotropy. Although this quantity is derived from the unitary transformations of the subsystem, it remains a global quantity of the system. Indeed, good markers for many-body localized phases can be found in the time behaviour not only of the entanglement entropy of the subsystem, but also of the local ergotropy and its quantum fluctuations. Our work sheds lights on the complex interplay between local ergotropy and many-body localized phases relevant for more realistic quantum batteries and for more general identifications of many-body quantum effects.
