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
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.
PACS: 05.70.Jk – Critical point phenomena / 64.60.Fr – Equilibrium properties near critical points, critical exponents / 75.10.Hk – Classical spin models / 75.50.Lk – Spin glasses and other random magnets
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999