Spin Quantum Heat Engine Quantified by Quantum Steering

TL;DR

This paper experimentally demonstrates that quantum steering, a form of quantum correlation, is essential for the quantum advantage in a Szilard heat engine, highlighting the role of non-classical correlations beyond coherence.

Contribution

It introduces quantum steering as a key factor in quantum heat engine advantage, distinct from quantum coherence, and provides experimental verification.

Findings

Quantum steering correlates with engine performance.

Quantum advantage is linked to steerability, not coherence.

Work extraction methods verify the quantum nature of the engine.

Abstract

Following the rising interest in quantum information science, the extension of a heat engine to the quantum regime by exploring microscopic quantum systems has seen a boom of interest in the last decade. Although quantum coherence in the quantum system of the working medium has been investigated to play a nontrivial role, a complete understanding of the intrinsic quantum advantage of quantum heat engines remains elusive. We experimentally demonstrate that the quantum correlation between the working medium and the thermal bath is critical for the quantum advantage of a quantum Szilard engine, where quantum coherence in the working medium is naturally excluded. By quantifying the non-classical correlation through quantum steering, we reveal that the heat engine is quantum when the demon can truly steer the working medium. The average work obtained by taking different ways of work extraction on the working medium can be used to verify the real quantum Szilard engine.