Critical finite-size scaling of magnetization distribution function for Baxter–Wu model

The distribution function PL(m) of the order parameter for the Baxter–Wu model is studied using blocks of linear dimension L of a larger triangular lattice. At a given temperature, we use the Metropolis algorithm for the generation of a sample of configurations on the triangular lattice. The similarities and differences of this distribution with the usual cases of Ising lattices are investigated. We conclude that the present model obeys, at the critical temperature, a finite-scaling law with the known critical exponents as expected. However, our numerical data strongly indicate that the analytic form of the scaling function does not conform to the corresponding function for the usual Ising model. An analytic expression that gives a good fit is presented.