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

TL;DR

This paper investigates the aging dynamics of the 2D Edwards-Anderson spin glass model, confirming the quasi-equilibrium picture in the pre-asymptotic regime through fluctuation-dissipation analysis.

Contribution

It introduces a new correlation function and response to test the quasi-equilibrium hypothesis in the pre-asymptotic aging regime of the 2D Edwards-Anderson model.

Findings

After a short transient, the fluctuation-dissipation ratios coincide for the two correlation functions.

The dynamic FDR at finite time matches the static FDR at finite size.

The quasi-equilibrium picture holds in the pre-asymptotic aging regime.

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.