STATICS AND DYNAMICS OF A MODEL OF SPIN-GLASSES (MONTE CARLO; PHASE TRANSITION)

Monte Carlo simulations are used to study the critical behavior of the classical Ruderman-Kittel-Kasuya-Yosida (RKKY) model of metallic spin-glasses both with and without the presence of weak Dzyaloshinsky-Moriya (DM) anisotropy. Finite-size scaling analyses of the data for equilibrium averages of various rotationally invariant quantities indicate a zero-temperature critical point for the isotropic RKKY model. When the DM interaction is included, the model exhibits a phase transition at a non-zero temperature. The observed temperature and sample-size dependence of various relaxation times are consistent with the above conclusions. The values of the critical exponents associated with the finite-temperature phase-transition in the presence of DM anisotropy are close to those obtained for the three-dimensional short-range Ising spin-glass and in experiments on Cu Mn.