Dressed Active Particles in Spherical Crystals

TL;DR

This paper explores how active particles in spherical crystals create localized defects, forming dressed particles that influence lattice behavior and defect patterns, revealing new insights into active matter and defect engineering.

Contribution

It introduces the concept of dressed active particles in spherical crystals, demonstrating their defect interactions and oscillating defect patterns, advancing understanding of active matter in crystalline environments.

Findings

Active particles are surrounded by localized topological defects.

Defect patterns oscillate between two motifs regardless of particle speed.

The physical picture aids in understanding nonequilibrium behaviors in active crystals.

Abstract

We investigate the dynamics of an active particle in two-dimensional spherical crystals, which provide an ideal environment to illustrate the interplay of active particle and crystallographic defects. A moving active particle is observed to be surrounded by localized topological defects, becoming a dressed active particle. Such a physical picture characterizes both the lattice distortion around the moving particle and the healing of the distorted lattice in its trajectory. We find that the dynamical behaviors of an active particle in both random and ballistic motions uniformly conform to this featured scenario, whether the particle is initially a defect or not. We further observe that the defect pattern around a dressed ballistic active particle randomly oscillates between two well-defined wing-like defect motifs regardless of its speed. The established physical picture of dressed active particles in this work partially deciphers the complexity of the intriguing nonequilibrium behaviors in active crystals, and opens the promising possibility of introducing the activity to engineer defects, which has strong connections with the design of materials.