Quantumness and TUR of finite-time Otto cycle

Sangyun Lee, Meesoon Ha, Hawoong Jeong

Published Nov 11, 2020• 0 citations

Abstract

In order to reveal the quantumness of the Otto cycle and discuss the validity of the thermodynamic uncertainty relation (TUR) in the cycle, we study the quantum Otto cycle and its classical counterpart. In particular, we calculate exactly the mean values and fluctuations of numerous thermodynamic quantities. In the quasistatic limit, quantumness reduces the productivity and reliability of the Otto cycle compared to that in the absence of quantumness, while in the finite-time limit, it can increase the cycle's productivity and reliability. Interestingly, as the strength (heat conductance) between the system and the bath increases, the reliability of the quantum Otto cycle overtakes that of the classical one. In testing the conventional TUR, in the region where the entropy production is large enough, we find a tighter bound than that of the conventional TUR, and also that the TUR of the Otto cycle in the quasistatic limit is still valid. However, in the finite-time mode, both quantum and classical Otto cycles violate the conventional TUR. This implies that another modified TUR is required to cover the finite-time Otto cycle. Finally, we discuss the possible origin of this violation in terms of the uncertainty products of the thermodynamic quantities and the relative fluctuations near resonance conditions.

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