Quantumness and thermodynamic uncertainty relation of finite-time Otto cycle

TL;DR

This paper investigates the influence of quantumness on the thermodynamic performance and uncertainty relations of finite-time Otto cycles, revealing conditions where quantum effects enhance or diminish efficiency and precision.

Contribution

It provides an exact analysis of thermodynamic quantities in quantum and classical Otto cycles, highlighting how quantumness affects productivity, precision, and TUR violations in finite-time regimes.

Findings

Quantumness reduces productivity and precision in quasistatic limit.

In finite-time, quantumness can enhance productivity and precision.

Quantum Otto cycle surpasses classical in precision with increased system-bath coupling.

Abstract

To reveal the role of the quantumness in the Otto cycle and to 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 relative error of thermodynamic quantities. In the quasistatic limit, quantumness reduces the productivity and precision of the Otto cycle compared to that in the absence of quantumness, whereas in the finite-time mode, it can increase the cycle's productivity and precision. Interestingly, as the strength (heat conductance) between the system and the bath increases, the precision of the quantum Otto cycle overtakes that of the classical one. Testing the conventional TUR of the Otto cycle, in the region where the entropy production is large enough, we find a tighter bound than that of the conventional TUR. However, in the finite-time mode, both quantum and classical Otto cycles violate the conventional TUR in the region where the entropy production is small. 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 error near resonance conditions.