Spin-glass ordering in diluted magnetic semiconductors: A Monte Carlo study

Abstract

We study the temperature-dilution phase diagram of a site-diluted Heisenberg antiferromagnet on a face-certered-cubic lattice, with and without the Dzyaloshinskii-Moriya anisotropic term, fixed to realistic microscopic parameters for ${\mathrm{IIB}}_{1-x}{\mathrm{Mn}}_x\mathrm{Te}(\mathrm{IIB}=\mathrm{Cd},\mathrm{Hg},\mathrm{Zn}).\mathrm{}$ We show that the dipolar Dzyaloshinskii-Moriya anisotropy induces a finite-temperature phase transition to a spin-glass phase, at dilutions larger than $80\%.$ The resulting probability distribution of the order parameter $P\left(q\right)\mathrm{}$ is similar to the one found in the cubic lattice Edwards-Anderson-Ising model. The critical exponents undergo large finite-size corrections, but tend to values similar to the ones of the Edwards-Anderson-Ising model.