Consequence of anisotropy on flocking: the discretized Vicsek model

Abstract

Abstract We numerically study a discretized Vicsek model (DVM) with particles orienting in q possible
orientations in two dimensions. The study probes the significance of anisotropic orientation and
microscopic interaction on the macroscopic behavior. The DVM is an off-lattice flocking model like
the active clock model [ACM; EPL 138, 41001 (2022)] but the dynamical rules of particle alignment
and movement are inspired by the prototypical Vicsek model (VM). The DVM shows qualitatively
similar properties as the ACM for intermediate noise strength where a transition from macrophase
to microphase separation of the coexistence region is observed as q is increased. But for small q
and noise strength, the liquid phase appearing in the ACM at low temperatures is replaced in the
DVM by a configuration of multiple clusters with different polarization which does not exhibit any
long-range order. We find that the dynamical rules have a profound influence on the overarching
features of the flocking phase. We further identify the metastability of the ordered liquid phase
subjected to a perturbation.