Entropy production given constraints on the energy functions

TL;DR

This paper analyzes how to transform probability distributions in finite-state systems with minimal entropy production under limited energy control, providing conditions and bounds for such transformations.

Contribution

It introduces a simple condition for zero-EP transformations with limited energy functions and derives a lower bound on EP under general constraints.

Findings

Small control over energy functions suffices for arbitrary state transformations.

A graph-theoretic condition determines the feasibility of zero-EP transformations.

A convex optimization framework bounds the entropy production under rate constraints.

Abstract

We consider the problem of driving a finite-state classical system from some initial distribution $p$ to some final distribution $p'$ with vanishing entropy production (EP), under the constraint that the driving protocols can only use some limited set of energy functions $\mathcal{E}$. Assuming no other constraints on the driving protocol, we derive a simple condition that guarantees that such a transformation can be carried out, which is stated in terms of the smallest probabilities in $\{p,p'\}$ and a graph-theoretic property defined in terms of $\mathcal{E}$. Our results imply that a surprisingly small amount of control over the energy function is sufficient (in particular, any transformation $p\to p'$ can be carried out as soon as one can control some one-dimensional parameter of the energy function, e.g., the energy of a single state). We also derive a lower bound on the EP under more general constraints on the transition rates, which is formulated in terms of a convex optimization problem.