An autonomous and reversible Maxwell's demon

TL;DR

This paper introduces a reversible autonomous Maxwell's demon model that manipulates entropy to lift a mass, with thermodynamic consistency, and explores its efficiency and operational regimes.

Contribution

It presents a reversible, thermodynamically consistent Maxwell's demon model allowing bidirectional tape movement and detailed efficiency analysis.

Findings

Model achieves reversibility with bidirectional tape movement.

Efficiency at maximum power is bounded by 1/2 for machines.

Model provides a thermodynamic interpretation akin to enzyme activity.

Abstract

Building on a model introduced by Mandal and Jarzynski [Proc. Natl. Acad. Sci. U. S. A., {\bf 109}, (2012) 11641], we present a simple version of an autonomous reversible Maxwell's demon. By changing the entropy of a tape consisting of a sequence of bits passing through the demon, the demon can lift a mass using the coupling to a heat bath. Our model becomes reversible by allowing the tape to move in both directions. In this thermodynamically consistent model, total entropy production consists of three terms one of which recovers the irreversible limit studied by MJ. Our demon allows an interpretation in terms of an enzyme transporting and transforming molecules between compartments. Moreover, both genuine equilibrium and a linear response regime with corresponding Onsager coefficients are well defined. Efficiency and efficiency at maximum power are calculated. In linear response, the latter is shown to be bounded by 1/2 if the demon operates as a machine and by 1/3 if it is operated as an eraser.