New Fluctuation Theorem on Maxwell's Demon

TL;DR

This paper introduces a new fluctuation theorem incorporating dissipative information to better understand Maxwell's demon, showing that the demon's influence always increases entropy and allowing for more work extraction than previous limits.

Contribution

The paper proposes a novel fluctuation theorem based on dissipative information, refining the understanding of Maxwell's demon's role in entropy production and energy control.

Findings

Dissipative information quantifies the demon's total contribution.

The new theorem shows the second law holds at coarse-grained levels.

More work and heat can be extracted than previously predicted.

Abstract

With the increasing interest for the control of the system at the nano and mesoscopic scales, studies have been focused on the limit of the energy dissipation in an open system by refining the concept of the Maxwell's demon. The well-known Sagawa-Ueda fluctuation theorem provides an explanation of the demon: the absence of a part of demon's information leads to an improper entropy production which violates the thermodynamic 2nd law. Realizing that the demon contributes not only to the system but also to the environments, we introduce the dissipative information to quantify the total contribution of the demon, rather than using an improper entropy production. We prove a set of new fluctuation theorems based on this, which can be used to uncover the truth behind the demon: The controlled system does not violate the 2nd law at any coarse-grained level for the demon's control. However, there exists an inevitable demon-induced dissipative information which always increases the entropy production. A consequence of these theorems is that, less work and more heat can be extracted and generated respectively by a demon than the limits predicted by the Ueda-Sagawa theorem. We also suggest a possible realization of the experimental estimation of these work and heat bounds, which can be measured and tested.