The roles of quantum coherence in thermodynamic processes

TL;DR

This paper investigates how quantum coherence influences thermodynamic processes, demonstrating that coherence significantly contributes to work and heat generation in finite-time quantum phenomena.

Contribution

It introduces a method to quantify coherence effects and reveals their pivotal roles in specific finite-time quantum thermodynamic processes.

Findings

Coherence primarily generates work in spin precession.

Coherence mainly contributes to heat in spontaneous photon emission.

Quantitative analysis of coherence effects in finite-time thermodynamics.

Abstract

Quantum coherence associated with the superpositions of two different sets of eigenbasis vectors has been regarded as essential in thermodynamics. It is found that coherent factors can be determined by writing observables as an expansion in the basis vectors of the systemic density operator and Hamiltonian. We reveal the roles of coherence in finite-time thermodynamic processes, such as the spin precession and the spontaneous emission of a photon. Results show that the work in the spin precession and the heat in the spontaneous emission process are mainly generated by coherence.