Micro-flock patterns and macro-clusters in chiral active Brownian disks.

Area of Science:

• Active matter physics
• Complex systems
• Statistical mechanics

Background:

• Chiral active particles, or self-propelled circle swimmers, display complex collective behaviors like rotating macro-clusters and micro-flocks.
• These patterns arise from the interplay of alignment and rotational dynamics, suggesting general applicability in chiral active matter.
• The impact of excluded volume interactions, common in real systems, on these patterns is not well understood.

Purpose of the Study:

• To investigate the survival and characteristics of macro-cluster and micro-flock patterns in chiral active particles when excluded volume interactions are present.
• To determine if the established scaling laws for micro-flock size are maintained under these conditions.

Main Methods:

• Computational modeling of chiral active particles with excluded volume interactions.
• Analysis of collective behavior, pattern formation, and statistical properties of clusters.
• Comparison of results with theoretical predictions and simulations lacking excluded volume effects.

Main Results:

• Macro-clusters and micro-flock patterns persist even with excluded volume interactions.
• These patterns exhibit significantly enhanced fluctuations in cluster size and shape.
• The average micro-flock size continues to scale linearly with the single-swimmer radius, preserving the characteristic scaling law.

Conclusions:

• Excluded volume interactions do not disrupt the fundamental pattern formation in chiral active matter.
• While fluctuations increase, the essential scaling behavior of micro-flock sizes remains robust.
• This suggests the generic nature of these collective behaviors and their scaling laws across various chiral active matter systems.