Regensburg 2019 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 23: Stochastic Thermodynamics
DY 23.1: Talk
Tuesday, April 2, 2019, 14:00–14:15, H20
Cycling tames power fluctuations near optimum efficiency — •Viktor Holubec1, 2 and Artem Ryabov2 — 1Institut für Theoretische Physik, Universität Leipzig, Leipzig, Germany — 2Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, Praha, Czech Republic
According to the laws of thermodynamics, no heat engine can beat the efficiency of a Carnot cycle. This efficiency traditionally comes with vanishing power output and practical designs, optimized for power, generally achieve far less. Recently, various strategies to obtain Carnot's efficiency at large power were proposed. However, a thermodynamic uncertainty relation implies that steady-state heat engines can operate in this regime only at the cost of large fluctuations that render them immensely unreliable. Here, we demonstrate that this unfortunate trade-off can be overcome by designs operating cyclically under quasi-static conditions. The experimentally relevant yet exactly solvable model of an overdamped Brownian heat engine is used to illustrate the formal result. Our study highlights that work in cyclic heat engines and that in quasi-static ones are different stochastic processes.
[1] Viktor Holubec and Artem Ryabov, Phys. Rev. Lett. 121, 120601 (2018)