Detailed Fluctuation Relation for Arbitrary Measurement and Feedback Schemes

TL;DR

This paper develops a comprehensive detailed fluctuation relation applicable to any measurement and feedback scheme, including complex scenarios like continuous measurements, enhancing the understanding of thermodynamic irreversibility and work extraction.

Contribution

It introduces a universal recipe for deriving detailed fluctuation relations that accommodate arbitrary measurement and feedback, overcoming limitations of previous approaches.

Findings

Derived a fluctuation relation valid for all measurement and feedback types.

Established an experimentally accessible inequality on extractable work.

Identified conditions where the inequality becomes an equality.

Abstract

Fluctuation relations are powerful equalities that hold far from equilibrium. However, the standard approach to include measurement and feedback schemes may become inapplicable in certain situations, including continuous measurements, precise measurements of continuous variables, and feedback induced irreversibility. Here we overcome these shortcomings by providing a recipe for producing detailed fluctuation relations. Based on this recipe, we derive a fluctuation relation which holds for arbitrary measurement and feedback control. The key insight is that fluctuations inferable from the measurement outcomes may be suppressed by post-selection. Our detailed fluctuation relation results in a stringent and experimentally accessible inequality on the extractable work, which is saturated when the full entropy production is inferable from the data.