Mean field theory of the ising random-amisotropy-axis model in the large-component limit

Abstract

The lsing random-anisotropy-axis model with additional noncubic anisotropy is investigated in mean-field theory in the limit p → ∞ for p-component random vectors on a lattice of N sites. The effects of anisotropy for statistically independent and identically distributed random-vector components with a trimodal probability distribution are studied in the limits ∝ = p/N = O and ∝ > O. Ferromagnetic, mixed, and residual ordered phases are found in the first case, while only mixed ordered and spin-glass phases are found for the latter. Phase diagrams with explicit phase boundaries are obtained.