Effects of Quantum Coherence on Work Statistics

TL;DR

This paper investigates how quantum coherence influences work statistics in quantum thermodynamics, revealing significant effects on average work and fluctuations, especially in the transverse Ising model, challenging traditional measurement approaches.

Contribution

It introduces a full counting statistics approach to analyze quantum coherence effects on work statistics, highlighting differences from the two-point measurement scheme and exploring phase-dependent phenomena.

Findings

Quantum coherence alters average work and fluctuations.

Coherence effects depend on phase, energy structure, and protocol.

Work statistics can show critical phenomena at high temperature due to coherence.

Abstract

In the conventional two-point measurement scheme of quantum thermodynamics, quantum coherence is destroyed by the first measurement. But as we know the coherence really plays an important role in the quantum thermodynamics process, and how to describe the work statistics for a quantum coherent process is still an open question. In this paper, we use the full counting statistics method to investigate the effects of quantum coherence on work statistics. First, we give a general discussion and show that for a quantum coherent process, work statistics is very different from that of the two-point measurement scheme, specifically the average work is increased or decreased and the work fluctuation can be decreased by quantum coherence, which strongly depends on the relative phase, the energy level structure and the external protocol. Then, we concretely consider a quenched 1-D transverse Ising model, and show that quantum coherence has a more significant influence on work statistics in the ferromagnetism regime compared with that in the paramagnetism regime, so that due to the presence of quantum coherence the work statistics can exhibit the critical phenonmenon even at high temperature.