Skip to Main content Skip to Navigation
Journal articles

Revisiting the flocking transition using active spins

Abstract : We consider an active Ising model in which spins both diffuse and align on lattice in one and two dimensions. The diffusion is biased so that plus or minus spins hop preferably to the left or to the right, which generates a flocking transition at low temperature/high density. We construct a coarse-grained description of the model that predicts this transition to be a first-order liquid-gas transition in the temperature-density ensemble, with a critical density sent to infinity. In this first-order phase transition, the magnetization is proportional to the liquid fraction and thus varies continuously. Using microscopic simulations, we show that this theoretical prediction holds in 2d whereas the fluctuations alter the transition in 1d, preventing for instance any spontaneous symmetry breaking.
Complete list of metadata
Contributor : Julien Tailleur Connect in order to contact the contributor
Submitted on : Tuesday, November 12, 2013 - 4:21:39 PM
Last modification on : Thursday, March 4, 2021 - 5:40:39 PM

Links full text



A. Solon, J. Tailleur. Revisiting the flocking transition using active spins. Physical Review Letters, American Physical Society, 2013, 111, pp.078101. ⟨10.1103/PhysRevLett.111.078101⟩. ⟨hal-00903641⟩



Les métriques sont temporairement indisponibles