Off equilibrium dynamics in 2d-XY system

Stéphane Abriet (1) , Dragi Karevski (1)

1 LPM - Laboratoire de physique des matériaux

We study the non-equilibrium time evolution of the classical XY spin model in two dimensions.The two-time autocorrelation and linear response functions are considered for systems initially preparedin a high temperature state and in a completely ordered state. After a quench into the critical phase, we determine, via Monte Carlosimulations, the time-evolution of these quantities and extract the temperature dependence of the slope of the parametric plotsusceptibility/correlation in the asymptotic regime. This slope is usually identified with the infinite fluctuation-dissipation ratiowhich measures the violation to the equilibrium fluctuation-dissipation theorem. However, a direct measure of this ratio leads to a vanishingvalue.

Mots clés: FDT; fluctuation dissipation ratio

Mots clés: Dynamic properties; Nonequilibrium XY model; aging

Domaines: Autre [cond-mat.other]; Mécanique statistique [cond-mat.stat-mech]

Stéphane Abriet, Dragi Karevski. Off equilibrium dynamics in 2d-XY system. 2003. ⟨hal-00000602⟩