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

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.