Duality and Renormalization Group for spin Glasses

by Dr Masayuki Ohzeki

Tuesday 7 Jun 2011, 15:00 → 16:30 Europe/Rome

Aula Conversi (Dipartimento di Fisica - Ed. G. Marconi)

I talk about the series of the studies [1-3] on the duality for spin glasses, especially on analytical evidence of absence of a finite-temperature spin glass transition for the random-bond Ising model on self-dual lattices [3]. The analysis is basically performed by an application of the extended duality relations by the replica method with real-space renormalization group analysis, which enables us to derive a precise but approximate location of the multicritical point on the Nishimori line. This duality analysis, in conjunction with the relationship between the multicritical point and the spin glass transition point for the symmetric distribution function of randomness, leads to the conclusion of the absence of a finite-temperature spin glass transition for the case of symmetric distribution. In addition to the stable conclusion for self-dual lattices implying two dimensionality, I will talk about my consideration, during the recent several weeks in Sapienza, for three-dimensional spin glasses through the same procedure. I can give the strong evidence of the absence of a finite-temperature spin glass transition for the random-plaquette gauge model, as for two-dimensional random-bond Ising model.