We analyze by means of extensive computer simulations the out of equilibrium dynamics of Edwards-Anderson spin glasses in d = 4 and d = 6 dimensions with ±J interactions. In particular, we focus our analysis on the scaling properties of the two-time autocorrelation function in a wide range of temperatures from T = 0.07T c to T = 0.75T c in both systems. In both the 4d and 6d models at very low temperatures we study the effects of discretization of energy levels. Strong sub-aging behaviors are found. We argue that this is because in the times accessible to our simulations the systems are only able to probe activated dynamics through the lowest discrete energy levels and remain trapped around nearly flat regions of the energy landscape. For temperatures T ≥ 0.5T c in 4d and 6d we find logarithmic scalings that are compatible with simple dynamical ultrametricity. Nevertheless the behaviour of the systems, even in 6d is very different from the mean field SK model results. © EDP Sciences, Società Italiana, di Fisica, Springer-Verlag 2003.
Stariolo D.A., Montemurro M.A., Tamarit F.A. (2003). Aging dynamics of ±J. Edwards-Anderson spin glasses. THE EUROPEAN PHYSICAL JOURNAL. B, CONDENSED MATTER PHYSICS, 32(3), 361-367 [10.1140/epjb/e2003-00110-y].
Aging dynamics of ±J. Edwards-Anderson spin glasses
Montemurro M. A.Membro del Collaboration Group
;
2003
Abstract
We analyze by means of extensive computer simulations the out of equilibrium dynamics of Edwards-Anderson spin glasses in d = 4 and d = 6 dimensions with ±J interactions. In particular, we focus our analysis on the scaling properties of the two-time autocorrelation function in a wide range of temperatures from T = 0.07T c to T = 0.75T c in both systems. In both the 4d and 6d models at very low temperatures we study the effects of discretization of energy levels. Strong sub-aging behaviors are found. We argue that this is because in the times accessible to our simulations the systems are only able to probe activated dynamics through the lowest discrete energy levels and remain trapped around nearly flat regions of the energy landscape. For temperatures T ≥ 0.5T c in 4d and 6d we find logarithmic scalings that are compatible with simple dynamical ultrametricity. Nevertheless the behaviour of the systems, even in 6d is very different from the mean field SK model results. © EDP Sciences, Società Italiana, di Fisica, Springer-Verlag 2003.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
