Quasi-equilibrium during aging of the 2D Edwards-Anderson model

Abstract

We test the quasi-equilibrium picture of the aging dynamics -strictly valid in the asymptotic dynamical regime of aging systems- in the pre-asymptotic aging regime of the two dimensional Edwards-Anderson spin glass model. We compare the fluctuation-dissipation characteristic for spin autocorrelation function and response with a corresponding one obtained for a suitably defined new correlation function and its conjugated response. In agreement with the quasi-equilibrium picture we find that after a short transient the two corresponding fluctuation-dissipation ratios (FDR) coincide at equal times. Moreover we show that, as it happens for the usual FDR, the new dynamic FDR at finite time coincides with the static one at finite size.