Critical behaviour of anisotropic magnets with quenched disorder: replica symmetry breaking studied by operator product expansion
We study critical behaviour of disordered magnets near four dimensions. We consider the system with explicit cubic anisotropy and scalar disorder and that with random direction of anisotropy axis. The quenched disorder is taken into account by replica method. Using the method of operator product expansion, we derive in the first order to $\epsilon$ approximation the renormalization group equations taking into account possible replica symmetry breaking.