Experimental observation of directional locking and dynamical ordering of colloidal monolayers driven across quasiperiodic substrates

TL;DR

This study experimentally demonstrates how colloidal monolayers exhibit directional locking and form dynamically ordered phases when driven across quasiperiodic substrates, revealing the influence of substrate symmetry on particle dynamics.

Contribution

First experimental observation of directional locking and dynamical ordering in colloidal monolayers on quasiperiodic substrates, confirming simulation predictions.

Findings

Monolayer locks to substrate symmetry axes at specific drive angles.

Dynamically ordered smectic phases form during locking.

Particle interactions lead to lane formation and ordering.

Abstract

We experimentally investigate the structural behavior of an interacting colloidal monolayer being driven across a decagonal quasiperiodic potential landscape created by an optical interference pattern. When the direction of the driving force is varied, we observe the monolayer to be directionally locked on angles corresponding to the symmetry axes of the underlying potential. At such locking steps we observe a dynamically ordered smectic phase in agreement with recent simulations. We demonstrate, that such dynamical ordering is due to the interaction of particle lanes formed by interstitial and non-interstitial particles.