Channels, measurements and post-selection in quantum thermodynamics

TL;DR

This paper explores how quantum channels, measurements, and post-selection can enhance work extraction in quantum thermodynamics, revealing fundamental connections and unbounded benefits from certain measurement strategies.

Contribution

It uncovers the relationship between unital and catalytic channels and analyzes the work benefits of post-selected measurements in quantum thermodynamics.

Findings

Post-selected measurements can lead to unbounded work benefits.

A connection between unital and catalytic channels is established.

Conditional work costs depend on measurement outcomes.

Abstract

We analyse the benefit, in terms of extracting work, of having a single use of a quantum channel or measurement in quantum thermodynamics. This highlights a connection between unital and catalytic channels, and some subtleties concerning the conditional work cost of implementing a measurement given that a certain result was obtained. We also consider post-selected measurements, and show that any non-trivial post-selection leads to an unbounded work benefit.