Effect of randomness in many coupled Potts models

LPTHE , Université Pierre et Marie Curie, Paris VI, Université Denis Diderot, Paris VII - Boite 126, Tour 16, 1er étage, 4 place Jussieu, F-75252 Paris Cedex 05, France

Received: 26 February 1996
Accepted: 14 June 1996

Abstract

Using 2-loop renormalization group calculations, we study a system of N two-dimensional Potts models with random bonds coupled together by their local energy density. This model can be seen as a generalization of the random Ashkin-Teller model. We found that, depending on the sign of the coupling term, the universality class of the system in the presence of randomness is different. Under particular consideration, this model presents an example of a first-order phase transition rounded by randomness.