Phase behaviour and dynamics of three-dimensional active dumbbell systems

TL;DR

This study numerically investigates the phase behavior and dynamics of three-dimensional active dumbbell systems with attractive interactions, revealing multiple phases and a novel percolating network phase.

Contribution

It provides a detailed phase diagram and uncovers a new dynamical phase, the percolating network, in active dumbbell systems with attraction.

Findings

Attraction is essential for nontrivial phases.

Identified disordered, gel, phase-separated, and percolating network phases.

Characterized helical motion in dense clusters.

Abstract

We present a comprehensive numerical study of the phase behavior and dynamics of a three-dimensional active dumbbell system with attractive interactions. We demonstrate that attraction is essential for the system to exhibit nontrivial phases. We construct a detailed phase diagram by exploring the effects of the system's activity, density, and attraction strength. We identify several distinct phases, including a disordered, a gel, and a completely phase-separated phase. Additionally, we discover a novel dynamical phase, that we name percolating network, which is characterized by the presence of a spanning network of connected dumbbells. In the phase-separated phase we characterize numerically and describe analytically the helical motion of the dense cluster.