Quantifying reversibility in a phase-separating lattice gas: an analogy with self-assembly

TL;DR

This paper investigates the reversibility of phase separation in a lattice gas as an analogy for self-assembly, using bond dynamics and fluctuation-response measurements to connect microscopic reversibility with observable behaviors.

Contribution

It introduces two methods to quantify reversibility in phase separation, linking microscopic bond dynamics with fluctuation-dissipation analysis.

Findings

Correlation and response functions relate directly to microscopic reversibility.

Reversibility varies over time and depends on observable choices.

Fast and slow degrees of freedom influence assembly dynamics.

Abstract

We present dynamic measurements of a lattice gas during phase separation, which we use as an analogy for self-assembly of equilibrium ordered structures. We use two approaches to quantify the degree of 'reversibility' of this process: firstly, we count events in which bonds are made and broken; secondly, we use correlation-response measurements and fluctuation-dissipation ratios to probe reversibility during different time intervals. We show how correlation and response functions can be related directly to microscopic (ir)reversibility and we discuss time-dependence and observable- dependence of these measurements, including the role of fast and slow degrees of freedom during assembly.