Scale Invariance in disordered systems: the example of the Random Field Ising Model

Giorgio Parisi , Nicolas Sourlas (1)

1 LPTENS - Laboratoire de Physique Théorique de l'ENS [École Normale Supérieure]

We show by numerical simulations that the correlation function of the random field Ising model (RFIM) in the critical region in three dimensions has very strong fluctuations and that in a finite volume the correlation length is not self-averaging. This is due to the formation of a bound state in the underlying field theory. We argue that this non perturbative phenomenon is not particular to the RFIM in 3-d. It is generic for disordered systems in two dimensions and may also happen in other three dimensional disordered systems.

Domaines: Autre [cond-mat.other]

Giorgio Parisi, Nicolas Sourlas. Scale Invariance in disordered systems: the example of the Random Field Ising Model. Physical Review Letters, 2002, 89, pp.257204. ⟨hal-00005329⟩