In the present work we study the critical properties of the ferromagnetic three-color Ashkin–Teller model (3AT) by means of a Migdal–Kadanoff renormalization group approach on a diamond-like hierarchical lattice. The analysis of the fixed points and flux diagram of the recursion relations is...

We use the Migdal–Kadanoff renormalization group technique to study the spin-3/2 Blume–Capel model under a random crystal field, in the two- and three-dimensional cases. Studying the fixed points and the phase diagrams established, we find interesting results allowing us to understand the...

Phase diagrams of the micromaser system are mapped out in terms of the physical parameters at hand like the atom cavity transit time τ, the atom–photon frequency detuning Δω, the number of thermal photons nb and the probability a for a pump atom to be in its excited state. Critical...

The two-dimensional ferromagnetic anisotropic Ashkin–Teller model is investigated through a real-space renormalization-group approach. The critical frontier, separating five distinct phases, recovers all the known exact results for the square lattice. The correlation length (νT) and crossover...