Rhythmic cluster generation in strongly driven colloidal dispersions

TL;DR

This study investigates how a high-speed dragged particle in a nematic colloidal dispersion causes rhythmic cluster formation and dissolution, revealing a mesoscopic correlation length unaffected by drag speed, supported by simulations and scaling theory.

Contribution

It introduces a novel understanding of cluster dynamics and correlation lengths in driven nematic colloids through simulations and theoretical analysis.

Findings

Clusters rhythmically grow and dissolve in front of the dragged particle

Cluster-cluster correlation length is independent of drag speed

Results align with a dynamical scaling theory

Abstract

We study the response of a nematic colloidal dispersion of rods to a driven probe particle which is dragged with high speed through the dispersion perpendicular to the nematic director. In front of the dragged particle, clusters of rods are generated which rhythmically grow and dissolve by rotational motion. We find evidence for a mesoscopic cluster-cluster correlation length, {\em independent} of the imposed drag speed. Our results are based on non-equilibrium Brownian dynamics computer simulations and in line with a dynamical scaling theory.