Geometric phaselike effects in a quantum heat engine

TL;DR

This paper explores how geometric phase effects, induced by periodic temperature modulations, influence the thermodynamics of quantum heat engines, revealing violations of universality in efficiency expansion and limitations of fluctuation theorems.

Contribution

It introduces a generating function approach to identify geometric phase effects in quantum heat engines and analyzes their impact on thermodynamic properties and fluctuation relations.

Findings

PBp effects can be observed via GF method in quantum heat engines.

Standard fluctuation theorems are not applicable with phase modulations.

The universality of efficiency at maximum power is violated due to PBp.

Abstract

By periodically driving the temperatures of reservoirs in quantum heat engines, geometric phase or Pancharatnam-Berry phase-like (PBp) effects in the thermodynamics can be observed. The PBp can be identified from a generating function (GF) method within an adiabatic quantum Markovian master equation formalism. The GF is shown not to lead to a standard open quantum system's fluctuation theorem in presence of phase-different modulations with an inapplicability in the use of the popular large deviation theory. Effect of coherences on the optimized value of the flux is nullified due to PBp contributions. The PBp causes the universality of the linear coefficient in the expansion of the efficiency at maximum power in terms of Carnot efficiency to be violated.