Verification of the Quantum Nonequilibrium Work Relation in the Presence of Decoherence

TL;DR

This paper confirms that the quantum nonequilibrium work relation holds in open quantum systems experiencing decoherence, validated through experiments with optically trapped ions across various conditions.

Contribution

It demonstrates experimentally that the quantum work relation remains valid under decoherence without dissipation, extending prior theoretical results.

Findings

Work relation remains valid with decoherence

Experimental validation using trapped ions

Works across different driving speeds and temperatures

Abstract

Although nonequilibrium work and fluctuation relations have been studied in detail within classical statistical physics, extending these results to open quantum systems has proven to be conceptually difficult. For systems that undergo decoherence but not dissipation, we argue that it is natural to define quantum work exactly as for isolated quantum systems, using the two-point measurement protocol. Complementing previous theoretical analysis using quantum channels, we show that the nonequilibrium work relation remains valid in this situation, and we test this assertion experimentally using a system engineered from an optically trapped ion. Our experimental results reveal the work relation's validity over a variety of driving speeds, decoherence rates, and effective temperatures and represent the first confirmation of the work relation for non-unitary dynamics.