SCOZA for D-dimensional spins

Abstract

The self-consistent Ornstein-Zernike approach (SCOZA) developed earlier by the authors for the lattice gas and Ising model as well as simple continuum fluids is extended to the D-vector spin model that includes the classical rotator model ( D = 2), the classical Heisenberg model ( D = 3), and the spherical-model limit ( D → ∞), in which the SCOZA becomes exact. The approach entails first formulating an exact treatment of the model that includes its response to the presence of a field H with one primary component H |) and a transverse component H ⊥.