Exploring the gap between thermal operations and enhanced thermal operations

TL;DR

This paper analytically proves that enhanced thermal operations (EnTO) cannot be approximately simulated by thermal operations (TO), establishing a fundamental difference in their laws of state conversions and coherence dynamics in quantum thermodynamics.

Contribution

The paper provides the first analytical proof that TO and EnTO are fundamentally different in their state transformation capabilities.

Findings

EnTO cannot be approximately realized by TO.

TO and EnTO lead to different state conversion laws.

Results clarify restrictions on coherence dynamics.

Abstract

The gap between thermal operations (TO) and enhanced thermal operations (EnTO) is an open problem raised in [Phys. Rev. Lett. 115, 210403 (2015)]. It originates from the limitations on coherence evolutions. Here we solve this problem by analytically proving that, a state transition induced by EnTO cannot be approximately realized by TO. It confirms that TO and EnTO lead to different laws of state conversions. Our results can also contribute to the study of the restrictions on coherence dynamics in quantum thermodynamics.