Classical Models

Classical statistical mechanics models solved by exact methods (transfer matrix, Kramers–Wannier duality, Onsager / Yang formulas).

Contents

• 2D Ising on the Square Lattice – partition function, Onsager $T_c$, Yang magnetization $M(T)$
• Six-Vertex / Ice Rule (Lieb 1967) – square-ice residual entropy, KDP / F-model phase classification, ferroelectric free energy.
• 2D Ising on the Triangular Lattice – frustrated AFM ($T_c = 0$) + Wannier 1950 residual entropy; FM (Houtappel 1950)