Finite-time quantum heat engines

Zapraszamy w środę 9.12.2020 o godz. 14:00 na seminarium.

Seminarium ONLINE pod tytułem: "Finite-time quantum heat engines" poprowadzi Otavio A. D. Molitor, ICTQT

Abstract: With the study of ever decreasing systems, it's paramount to understand thermodynamic phenomena in ultra-small scales, where quantum phenomena live. This gave origin to the flourishing research field known as quantum thermodynamics. One of its main branches, which deals with quantum systems undergoing thermodynamic cycles, is called quantum heat engines (QHEs). These are assembled to convert one kind of energy into another, namely heat into work, in the quantum domain. The idea of converting heat into work has been intensively explored since the First Industrial Revolution, but it gains new direction with the many possibilities brought by quantum theory resources, such as coherence and entanglement. For optimizing the output power of these QHEs, one must consider finite-time operation. In this seminar, I will present a new model of finite-time QHEs. By means of using collisional models, a cyclic sequence of pure heat and pure work strokes are applied to a generic quantum chain. This gives rise to a stroboscopic evolution of the state of the quantum chain, which presents a transient regime as well as a limit cycle. Once reached the limit cycle, the results show that the heat exchanged with the heat baths depends solely on the boundary sites of the quantum chain. The model is proved useful for the optimization of the output power of stroke-based QHEs both analytically and numerically. One curious feature of this framework is that, for a given family of models containing a specific kind of internal interactions, there is a universal efficiency value, the Otto efficiency, which remains the same for any cycle period.