Work, entropy production, and thermodynamics of information under protocol constraints

TL;DR

This paper develops a theoretical framework to analyze entropy production, work, and information thermodynamics under physical and operational constraints, providing bounds, decompositions, and applications to various models.

Contribution

It introduces a decomposition of free energy and information into accessible and inaccessible parts under constraints, advancing the understanding of thermodynamics with limited control.

Findings

Derived bounds on entropy production and extractable work under constraints.

Decomposed free energy and information into accessible and inaccessible components.

Applied framework to models like Szilard box, Ising model, and ratchets.

Abstract

In many real-world situations, there are constraints on the ways in which a physical system can be manipulated. We investigate the entropy production (EP) and extractable work involved in bringing a system from some initial distribution $p$ to some final distribution $p'$, given that the set of master equations available to the driving protocol obeys some constraints. We first derive general bounds on EP and extractable work, as well as a decomposition of the nonequilibrium free energy into an "accessible free energy" (which can be extracted as work, given a set of constraints) and an "inaccessible free energy" (which must be dissipated as EP). In a similar vein, we consider the thermodynamics of information in the presence of constraints, and decompose the information acquired in a measurement into "accessible" and "inaccessible" components. This decomposition allows us to consider the thermodynamic efficiency of different measurements of the same system, given a set of constraints. We use our framework to analyze protocols subject to symmetry, modularity, and coarse-grained constraints, and consider various examples including the Szilard box, the 2D Ising model, and a multi-particle flashing ratchet.