Milling-induction and milling-destruction in a Vicsek-like binary-mixture model

Milling is a collective circular motion often observed in nature (e.g., in fish schools) and in many theoretical models of collective motion. In these models particles are considered to be identical. However, this is not the case in nature, where even individuals of the same species differ from each other in one or more traits. In order to get insights into the mechanisms of milling formation in heterogeneous systems (i.e., with non-identical particles), the emergence of milling in a binary mixture of particles that differ in one trait is investigated for the first time. Depending on parameter values, particles that in single-type systems do not mill can either be induced to mill or destroy the milling of other particles. Milling-induction and milling-destruction are studied varying the speed, the field of view, and the relative amount of the two types of particles. Copyright (C) EPLA, 2019