Interface stability, interface fluctuations, and the Gibbs-Thomson relation in motility-induced phase separations

TL;DR

This paper models the microscopic dynamics of active particles in motility-induced phase separations to explain interface stability, fluctuations, and the Gibbs-Thomson relation, revealing classic coarsening behavior in MIPS.

Contribution

It introduces a microscopic model explaining interface phenomena in MIPS and validates the Gibbs-Thomson relation within this context.

Findings

Interfacial stability and fluctuations are explained by microscopic dynamics.

The Gibbs-Thomson relation holds in MIPS, linking drop size and vapor concentration.

Late-stage coarsening follows Lifshitz-Slyozov scaling law.

Abstract

Minimal models of self-propelled particles with short-range volume exclusion interactions have been shown to exhibit signatures of phase separation. Here I show that the observed interfacial stability and fluctuations in motility-induced phase separations (MIPS) can be explained by modeling the microscopic dynamics of the active particles in the interfacial region. In addition, I demonstrate the validity of the Gibbs-Thomson relation in MIPS, which provides a functional relationship between the size of a condensed drop and its surrounding vapor concentration. As a result, the coarsening dynamics of MIPS at vanishing supersaturation follows the classic Lifshitz-Slyozov scaling law at the late stage.