Oscillatory driven colloidal binary mixtures: axial segregation versus laning

TL;DR

This study uses Brownian dynamics simulations to explore how oscillating external fields induce axial segregation and lane formation in driven colloidal binary mixtures, revealing frequency and force-dependent phase behavior.

Contribution

It demonstrates the existence of stable axial segregation in oscillating driven colloids and characterizes the transition to lane formation with varying driving parameters.

Findings

Axial segregation occurs in specific frequency and force windows.

Lane formation dominates at higher driving forces.

Tilted band structures appear in the crossover regime.

Abstract

Using Brownian dynamics computer simulations we show that binary mixtures of colloids driven in opposite directions by an oscillating external field exhibit axial segregation in sheets perpendicular to the drive direction. The segregation effect is stable only in a finite window of oscillation frequencies and driving strengths and is taken over by lane formation in direction of the driving field if the driving force is increased. In the crossover regime, bands tilted relative to the drive direction are observed. Possible experiments to verify the axial segregation are discussed.