Competition between fluctuations and disorder in frustrated magnets

Julien Serreau, Matthieu Tissier

Published 2002-05-02, updated 2003-02-21Version 2

We investigate the effects of impurities on the nature of the phase transition in frustrated magnets, in d=4-epsilon dimensions. For sufficiently small values of the number of spin components, we find no physically relevant stable fixed point in the deep perturbative region (epsilon << 1), contrarily to what is to be expected on very general grounds. This signals the onset of important physical effects.