Mean field renormalization group study of a modified Ashkin-Teller model

We study the phase diagram of a generalization of the Ashkin-Teller model in two dimensions using the mean-field renormalization group (MFRG) theory. We calculate critical surfaces for this three-parameter Hamiltonian of the model using two different approaches, and we discuss the resulting phase diagram and compare it with the results from the molecular-field approximation.