Stripes, Clusters, and Nonequilibrium Ordering for Bidisperse Colloids with Repulsive Interactions

TL;DR

This study demonstrates that driven bidisperse colloids with repulsive interactions form highly ordered nonequilibrium patterns like stripes and clusters on a quenched substrate, revealing a new method to control colloidal patterning.

Contribution

It reveals how driving and quenched disorder induce novel ordered states in bidisperse colloids, surpassing equilibrium configurations.

Findings

Nonequilibrium states are more ordered than equilibrium ones.

A minimum substrate strength is required for pattern formation.

Pattern types include stripes, clusters, and partial crystallization.

Abstract

We show that two-dimensional bidisperse assemblies of colloids with strictly repulsive interactions exhibit stripe, cluster, and partially crystallized states when driven over a quenched random substrate. The nonequilibrium states on a substrate are significantly more ordered than equilibrium states both with and without substrates. A minimum substrate strength is necessary to induce the nonequilibrium pattern formation. Our results suggest that a combination of driving and quenched disorder offers a new approach to controlling pattern formation in colloid mixtures.