Violation of the Fluctuation Dissipation Theorem during Domain Growth in the Long-range Ising Model

Abstract

The celebrated {\it fluctuation dissipation theorem} (FDT) does not apply to nonequilibrium systems. In this context, Cugliandolo and Kurchan [Phys. Rev. Lett. {\bf 71}, 173 (1993)] introduced a generalized FDT which interprets the nonequilibrium evolution as a composition of {\it time sectors} corresponding to different {\it effective temperatures}. We use this framework to study domain growth in the $d=2$ long-range Ising model (LRIM) with nonconserved kinetics ({\it Glauber spin-flip}) and conserved kinetics ({\it Kawasaki spin-exchange}). We study the dynamical scaling and super-universal (SU) scaling of various two-time quantities, e.g., autocorrelation function, response function, effective temperature, etc. In particular, we investigate how the interaction range and conservation laws affect these characteristic features of domain growth.