Phase diagram of the three-dimensional Gaussian random field Ising model: A Monte Carlo renormalization-group study - art. no. 012415

With the help of the replica exchange Monte Carlo method and the improved M onte Carlo renormalization-group scheme, we investigate over a wide area in the phase diagram of the Gaussian random field Ising model on the simple c ubic lattice. We found that the phase transition at a weak random field bel ongs to the same universality class as the zero-temperature phase transitio n. We also present a possible scenario for the replica symmetry-breaking tr ansition.