Eur. Phys. J. B 7, 105-109 (1999)
https://doi.org/10.1007/s100510050593

Universality in three dimensional random-field ground states

¹ Institut für theoretische Physik, Philosophenweg 19, 69120 Heidelberg, Germany
² Theoretische Tieftemperaturphysik, Gerhard-Mercator-Universität-Duisburg, 47048 Duisburg, Germany

Received: 9 July 1998
Revised: 15 July 1998
Accepted: 20 July 1998
Published online: 15 January 1999

Abstract

We investigate the critical behavior of three-dimensional random-field Ising systems with both Gauss and bimodal distribution of random fields and additional the three-dimensional diluted Ising antiferromagnet in an external field. These models are expected to be in the same universality class. We use exact ground-state calculations with an integer optimization algorithm and by a finite-size scaling analysis we calculate the critical exponents ν, β, and . While the random-field model with Gauss distribution of random fields and the diluted antiferromagnet appear to be in same universality class, the critical exponents of the random-field model with bimodal distribution of random fields seem to be significantly different.