Articles dans des revues à comité de lecture
|Off equilibrium dynamics in the 2d-XY system|
|Abriet S., Karevski D.|
|European Physical Journal B 37 (2004) 47|
|ArXiv : cond-mat/0309342 [PDF]|
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 prepared in a high temperature state and in a completely ordered state. After a quench into the critical phase, we use Monte Carlo simulations to determine the time-evolution of these quantities, and we deduce the temperature dependence of the slope of the parametric plot susceptibility/correlation in the asymptotic regime. This slope is usually identified with the infinite fluctuation-dissipation ratio, which measures the extent of violation of the equilibrium fluctuation-dissipation theorem. However, a direct measure of this ratio leads to a vanishing value.