J. Phys. I France
Volume 4, Numéro 1, January 1994
Page(s) 139 - 146
DOI: 10.1051/jp1:1994127
J. Phys. I France 4 (1994) 139-146

Towards an experimental determination of the number of metastable states in spin-glasses?

J.P. Bouchaud1, 2, E. Vincent2 and J. Hammann2

1  TCM Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE, U.K.
2  Service de Physique de l'Etat Condensé, Orme des Merisiers, CEA-Saclay, 91191 Gif s/Yvette cedex, France

(Received 25 August 1993, accepted 15 October 1993)

We argue that the systematic deviation from perfect aging (which means that the relaxation function only depend on the ratio $\frac{t}{t_w}$, where $t_{\small {w}}$ is the waiting time) observed in spin-glasses can be accounted for if the number of available metastable states is finite. A significant fraction of these metastable states will be visited after an "ergodic" time which we estimate from the experiments to be $\approx$ 106 seconds. This corresponds to $\approx$ 1012-1014 diffèrent metastable states per independent subsystem.

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