title: Nucleation-induced transition to collective motion in active systems.
abstract: While the existence of polar ordered states in active systems is well established, the dynamics of the self-assembly processes are still elusive. We study a lattice gas model of self-propelled elongated particles interacting through excluded volume and alignment interactions, which shows a phase transition from an isotropic to a polar ordered state. By analyzing the ordering process we find that the transition is driven by the formation of a critical nucleation cluster and a subsequent coarsening process. Moreover, the time to establish a polar ordered state shows a power-law divergence.
authors.affiliation: Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, 80333 Munich, Germany.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Weber
authors.forename: Volker
authors.initials: V
authors.lastname: Schaller
authors.forename: Andreas R
authors.initials: AR
authors.lastname: Bausch
authors.forename: Erwin
authors.initials: E
authors.lastname: Frey
mesh_terms: D005740:Gases / Q000737:chemistry; D008962:Models, Theoretical; D009038:Motion; D013269:Stochastic Processes; D013997:Time Factors
chemical_list: D005740:Gases