Eur. Phys. J. B (2015) 88: 94
https://doi.org/10.1140/epjb/e2015-50864-4

Regular Article

Critical aspects of three-dimensional anisotropic spin-glass models

¹ Department of Physics, Section of Solid State Physics, University of Athens, Panepistimiopolis, Zografou, 15784 Athens, Greece
² Applied Mathematics Research Centre, Coventry University, Coventry, CV1 5FB, UK

^a e-mail: nikolaos.fytas@coventry.ac.uk

Received: 17 December 2014
Received in final form: 10 March 2015
Published online: 8 April 2015

Abstract

We study the three-dimensional ± J Ising model with a longitudinal anisotropic bond randomness on the simple cubic lattice. The random exchange interaction is applied only in the z direction, whereas in the other two directions, xy-planes, we consider ferromagnetic exchange. By implementing an effective parallel tempering scheme, we outline the phase diagram of the model and compare it to the corresponding isotropic one. We present a detailed finite-size scaling analysis of the ferromagnetic-paramagnetic and spin glass-paramagnetic transition lines, and we also discuss the ferromagnetic-spin glass transition regime. We conclude that the present model shares the same universality classes with the isotropic model, but at the symmetric point has a considerably higher transition temperature from the spin-glass state to the paramagnetic phase. Our data for the ferromagnetic-spin glass transition line support a forward behavior in contrast to the reentrant behavior of the corresponding isotropic model.