Scattering Properties of Paramagnetic Ground States in the Three-Dimensional Random-Field Ising Model

Abstract

We study the ground-state (T = 0) morphologies in the d = 3 random-field Ising model (RFIM) using a computationally efficient graph-cut method. We focus on paramagnetic states which arise for disorder strengths Δ> Δc, where Δc is the critical disorder strength at T = 0. These paramagnetic states consist of correlated "domains" of up and down spins which are separated by rough, fractal interfaces. They show novel scattering properties with a cusp singularity in the correlation function at short distances.

10 pages, 6 figures, Accepted for publication in Europhysics Letters