Dynamical Ordering and Directional Locking For Particles Moving Over Quasicrystalline Substrates

TL;DR

This study uses molecular dynamics simulations to explore how particles like vortices or colloids move over quasicrystalline substrates, revealing various ordered moving phases and directional locking effects influenced by drive angle and filling fraction.

Contribution

It introduces the concept of dynamically induced Archimedean-like tiling and details how driven phases and directional locking depend on drive angle and filling fraction.

Findings

Diverse ordered moving phases including square, smectic, and Archimedean-like tiling.

Directional locking occurs at specific drive angles.

Dynamical phases vary significantly with filling fraction.

Abstract

We use molecular dynamics simulations to study the driven phases of particles such as vortices or colloids moving over a decagonal quasiperiodic substrate. In the regime where the pinned states have quasicrystalline ordering, the driven phases can order into moving square or smectic states, or into states with aligned rows of both square and triangular tiling which we term dynamically induced Archimedean-like tiling. We show that when the angle of the drive is varied with respect to the substrate, directional locking effects occur where the particle motion locks to certain angles. It is at these locking angles that the dynamically induced Archimedean tiling appears. We also demonstrate that the different dynamical orderings and locking phases show pronounced changes as a function of filling fraction.