Off-equilibrium dynamics at very low temperatures in three-dimensional spin glasses

We present a high-statistic systematic study of the overlap correlation function well below the critical temperature in the three-dimensional Gaussian spin glass. The off-equilibrium correlation function has been studied confirming the power law behaviour for the dynamical correlation length. In particular, we have computed the dynamical critical exponent z in a wide range of temperatures, 0.35 less than or equal to T less than or equal to 0.9, obtaining a dependence z(T) = 6.2/T in very good agreement with recent experiments. Moreover, we report a study of the violation of the fluctuation-dissipation theorem for very low temperatures T = 0.5 and 0.35. All our numerical results avoid a droplet model interpretation even when T is as low as T = 0.35.