Second law, entropy production, and reversibility in thermodynamics of information

TL;DR

This paper reviews the thermodynamics of information, emphasizing the second law, entropy production, and the distinctions among reversibility concepts, while clarifying the roles of measurement, feedback, and mutual information in thermodynamic processes.

Contribution

It provides a clear pedagogical analysis of the relationships among thermodynamic, logical, and heat emission reversibility, and clarifies their distinctions within information thermodynamics.

Findings

Thermodynamic, logical, and heat emission reversibility are fundamentally distinct.

The second law remains valid in measurement and feedback processes when mutual information is included.

The Landauer principle and Maxwell's demon are consistent with the second law when mutual information is considered.

Abstract

We present a pedagogical review of the fundamental concepts in thermodynamics of information, by focusing on the second law of thermodynamics and the entropy production. Especially, we discuss the relationship among thermodynamic reversibility, logical reversibility, and heat emission in the context of the Landauer principle and clarify that these three concepts are fundamentally distinct to each other. We also discuss thermodynamics of measurement and feedback control by Maxwell's demon. We clarify that the demon and the second law are indeed consistent in the measurement and the feedback processes individually, by including the mutual information to the entropy production.