A detailed numerical study is made of relaxation at equilibrium in the Sherrington-Kirkpatrick Ising spin glass (ISG) model, at and above the critical temperature $T_g$. The data show a long time stretched exponential relaxation $q\left(t\right)\sim \exp \{-{[t/\tau \left(T\right)]}^{\beta \left(T\right)}\}$ with an exponent $\beta \left(T\right)$ tending to $\approx$1/3 at $T_g$. The results are compared to those which were observed by A. T. Ogielski, [Phys. Rev. B 32, 7384 (1985)] in the three-dimensional ISG model and are discussed in terms of a phase space percolation transition scenario.

• Received 6 May 2011

DOI:https://doi.org/10.1103/PhysRevB.84.054442