Nucleation-induced transition to collective motion in active systems


Christoph A. Weber, Volker Schaller, Andreas R. Bausch, and Erwin Frey. 2012. “Nucleation-induced transition to collective motion in active systems.” Phys. Rev. E, 86, Pp. 030901.


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.