Critical properties of the eight-vertex model in a field
Institute of Physics, Slovak Academy of Sciences - Dúbravská cesta 9, SK-845 11, Bratislava, Slovakia, EU
Received: 18 July 2016
Accepted: 19 September 2016
The general eight-vertex model on a square lattice is studied numerically by using the Corner Transfer Matrix Renormalization Group method. The method is tested on the symmetric (zero-field) version of the model, the obtained dependence of critical exponents on model's parameters is in agreement with Baxter's exact solution and weak universality is verified with a high accuracy. It was suggested long time ago that the symmetric eight-vertex model is a special exceptional case and in the presence of external fields the eight-vertex model falls into the Ising universality class. We confirm numerically this conjecture in a subspace of vertex weights, except for two specific combinations of vertical and horizontal fields for which the system still exhibits weak universality.
PACS: 64.60.F- – Equilibrium properties near critical points, critical exponents / 05.50.+q – Lattice theory and statistics (Ising, Potts, etc.) / 05.70.Jk – Critical point phenomena
© EPLA, 2016