Simulation of optimal work extraction for quantum systems with work storage

Abstract

The capacity to extract work from a quantum heat machine is not only of practical value but also lies at the heart of understanding quantum thermodynamics. In this paper, we investigate optimal work extraction for quantum systems with work storage, where extracting work is completed by a unitary evolution on the composite system. We consider the physical requirement of energy conservation both strictly and on average. For both, we construct their corresponding unitaries and propose variational quantum algorithms for optimal work extraction. We show that maximal work extraction in general can be feasible when energy conservation is satisfied on average. We demonstrate with numeral simulations using a continuous-variable work storage. Our work show an implementation of a variational quantum computing approach for simulating work extraction in quantum systems.