Information free energy for nonequilibrium states

TL;DR

This paper introduces an information free energy concept for nonequilibrium thermodynamic systems, establishing it as a state function that generalizes equilibrium free energies and has implications for work theorems and feedback control.

Contribution

It proposes a new nonequilibrium free energy that extends classical thermodynamics and applies to systems with external driving and feedback control.

Findings

The information free energy is a nonequilibrium state function.

It generalizes equilibrium and steady state free energies.

It serves as a Lyapunov function for nonequilibrium dynamics.

Abstract

We introduce an information free energy for thermodynamic systems driven by external time-dependent parameters. We show that the latter is a nonequilibrium state function and that it is a natural generalization of the usual equilibrium and steady state free energies. We discuss its importance for the nonequilibrium maximum work theorem and the Jarzynski relation in the presence of feedback control. We further show that it is a nonequilibrium Lyapunov function.