Collective pattern formation in a binary mixture of self-propelled particles

Abstract

We have studied the collective behaviour of a binary mixture of self-propelled particles (SPPs) with non-identical motile properties. The two types of SPPs with low and high velocity is modelled in a two-dimensional system with periodic boundary conditions (PBCs) at a fixed particle density. The two types have two widely different velocities. The alignment interaction rule and angular noise similar to Vicsek Model (VM) is implemented in this model. Both inter and intra-particle interactions are considered among the SPPs. The system exhibits various self-organised pattern formation and phase segregation which mainly depends on the angular noise present in the system. Without any restriction of interaction or repulsion among the particles, the SPPs phase-separated into dense structures. The orientational order-disorder phase transition is studied, and nontrivial results are obtained. Cluster size distribution (CSD) for the entire system is also studied at the transition region. The CSD exhibits a power-law behaviour at the transition, with an exponent that of the standard percolation.