Coherent-Anomaly Analysis with Cluster Variation Method for Spin-Pair Correlation Function of Ising Model on Square Lattice

The spin-pair correlation functions in the Ising model on the square lattice are obtained in three approximations of the simplified cluster variation method. We find good estimates of the critical exponents ην, μ and ν, by applying the coherent-anomaly method to the obtained spin-pair correlation functions.