Correlated disordered interactions on Potts models.
Using a weak-disorder scheme and real-space renormalization-group techniques, we obtain analytical results for the critical behavior of various q-state Potts models with correlated disordered exchange interactions along d(1) of d spatial dimensions on hierarchical (Migdal-Kadanoff) lattices. Our results indicate qualitative differences between the cases d-d(1)=1 (for which we find non-physical random fixed points, suggesting the existence of non-perturbative fixed distributions) and d-d(1)>1 (for which we do find acceptable perturbative random fixed points), in agreement with previous numerical calculations by Andelman and Aharony [Phys. Rev. B 31, 4305 (1985)]. We also rederive a criterion for relevance of correlated disorder, which generalizes the usual Harris criterion.
Muzy
P T
PT
Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05315-970 São Paulo, Sao Paulo, Brazil. ptmuzy@uol.com.br
Vieira
A P
AP
Salinas
S R
SR