Finite-size effects in quantum thermodynamics




Jagiellonian University

January 18, 2023 12:30 PM

The necessity to go beyond classical thermodynamics is usually motivated by the fact that at the nanoscale quantum effects, like coherence and entanglement, start playing an important role. However, in the quantum regime one also deals with systems composed of a finite number of particles n, whereas the theory of thermodynamics is traditionally constrained to the study of macroscopic systems with n-> ∞, whose energy fluctuations are negligible compared to their average energy. In this talk I will address this problem and describe recent developments allowing one to go beyond the thermodynamic limit and rigorously investigate thermodynamic transformations of finite-size systems. I will explain why such transformations are generally irreversible and consume free energy, and how this affects the performance of thermodynamic protocols. A new version of the famous fluctuation-dissipation theorem will also be presented, linking the minimal amount of free energy dissipated in the process to the amount of free energy fluctuations present in the system’s initial state. Moreover, I will discuss a novel resource resonance phenomenon, which allows one to significantly reduce dissipation for transformations between states whose fluctuations are properly tuned. Finally, I will also explain how quantum coherence may bring states closer to resonance effectively decreasing the dissipation of free energy.

This is a hybrid event:

Al. Lotników 32/46, Warsaw, Room D

and Zoom (Link)