Revisiting the flocking transition using active spins - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Review Letters Année : 2013

Revisiting the flocking transition using active spins

A. Solon
J. Tailleur

Résumé

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.

Dates et versions

hal-00903641 , version 1 (12-11-2013)

Identifiants

Citer

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

Altmetric

Partager

Gmail Facebook X LinkedIn More