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...

We study Baxter–Wu triangular model with fixed magnetization in the framework of canonical and microcanonical ensemble, constructing the density of states by Wang–Landau algorithm. We use an approximation similar to a recently developed scheme (critical minimum energy subspace). In this...

We use the recently developed critical minimum energy subspace (CrMES) approximation scheme to study the critical behavior of the Baxter–Wu model. This scheme uses only a properly determined part of the energy spectrum and allows us to obtain high accuracy for relatively large systems with...

Using a finite-size phenomenological theory we investigate the behavior of the Baxter–Wu model for both first- and second-order transitions. In order to distinguish between the two kinds of transition we study the finite-size scaling behavior of the order parameter and the susceptibility of...

The Ising model in the presence of a random field is investigated within the mean field approximation based on Landau expansion. The random field is drawn from the trimodal probability distribution P(hi)=pδ(hi−h0)+qδ(hi+h0)+rδ(hi), where the probabilities p,q,r take on values within the...

The Ising model, in the presence of a random field, is investigated within the mean-field approximation based on Landau expansion. The random field is drawn from the bimodal probability distribution P(h)=pδ(h−h0)+(1−p)δ(h+h0), where the probability p assumes any value within the interval...