Journal of the Physical Society of Japan
Spin Correlations and Magnetic Susceptibility of the Two-Dimensional Ising Model
Yoshiaki Tanaka
Abstract
For the Ising model on the two-dimensional lattice with M × N spin sites ( M is a finite number; N →∞), arbitrary two-spin correlations are evaluated exactly. We make use of spinor analysis, which was employed by Kaufman and Onsager. The zero-field magnetic susceptibility χ 0 that is equal to the sum of all two-spin correlations, is calculated.