Quantum thermal engines: Selected results and open problems

Giuliano Benenti is Professor in Theoretical Physics (Condensed Matter) at Insubria University, Como, Italy. His main scientific interests include nonlinear and complex systems, open quantum systems, quantum computation and quantum information. His research covered several aspects of quantum thermodynamics, including thermal and thermoelectric transport, quantum batteries, and heat engine.

Abstract

Since its inception, the development of thermodynamics and its technological applications have been boosted by fundamental questions. A key question is what the ultimate bounds to the performance of heat engines are. It is desirable that a heat engine operates close to the ideal, Carnot efficiency, delivers large power, and exhibits small power fluctuations. Thermodynamic uncertainty relations (TURs) set a lower bound on the time-integrated relative fluctuation of an arbitrary current, which diverges when the dissipationless limit required for ideal efficiency is achieved. The application of such relations leads, under suitable conditions, to a trade-off between efficiency, power, and fluctuations. The validity range of TURs in quantum systems is still under debate. This talk discusses the above problems for periodically driven heat engines, with modulated couplings between the working medium and the baths, engineered in a suitable way to perform useful thermodynamic tasks, including engine, refrigerators, and hybrid working modes, as well as the realization of heat rectifiers and transistors. The relevance of non-Markovianity of the baths and the appearance dissipation-induced cooperative advantage in quantum thermal engines will be also discussed.