Disordered Yet Directed: The Emergence of Polar Flocks with Disordered Interactions

TL;DR

This paper introduces a new self-propelled particle model with quenched disorder in interactions, demonstrating that activity can promote flocking even with predominantly anti-aligning couplings, revealing novel collective behavior.

Contribution

The study presents a model where quenched disorder in interactions can still lead to polar flocking, highlighting the role of activity in overcoming frustration.

Findings

Quenched disorder can promote flocking despite anti-aligning interactions.

Activity reduces frustration, enabling local clustering and global order.

Flocking occurs even when most interactions are anti-aligning.

Abstract

Flocking is a prime example of how robust collective behavior can emerge from simple interaction rules. The flocking transition has been studied extensively since the inception of the original Vicsek model. Here, we introduce a novel self-propelled particle model with quenched disorder in the pairwise alignment interaction couplings akin to a spin glass model. We show that the presence of quenched disorder can promote (rather than destroy) the emergence of global polar order. In particular, we show that our model can display a flocking phase even when the majority of the interaction couplings are anti-aligning. Activity is the key ingredient to reduce frustration in the system as it allows local particle clustering combined with self-organization of the particles to favor neighborhoods with strong cooperative interactions.