Renormalization group approach to spin glass systems

A renormalization group transformation suitable for spin glass models and, more generally, for disordered models, is presented. The procedure is non-standard in both the nature of the additional interactions and the coarse graining transformation, that is performed on the overlap probability measure. Universality classes are thus naturally defined on a large set of models, going from Z 2 and Gaussian spin glasses to Ising and fully frustrated models, and others. The proposed analysis is tested numerically on the Z 2 Edwards–Anderson model in d = 4. Good estimates of the critical index ν and of Tc are obtained, and an RG flow diagram is sketched for the first time. PACS. 75.10.Nr Spin-glass and other random models – 05.10.Cc Renormalization group methods