An extension of the Blume-Emery-Griffiths model with a plaquette four-spin interaction term, on the square lattice, is investigated by means of the cluster variation method in the square approximation. The ground state of the model, for negative plaquette interaction, exhibits several new phases, including frustrated ones. At finite temperature we obtain a quite rich phase diagram with two new phases, a ferrimagnetic and a weakly ferromagnetic one, and several multicritical points.
Phase transitions in a spin-1 model with plaquette interaction on the square lattice / BUZANO C.; L.R. EVANGELISTA; A. PELIZZOLA. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - 53(1996), pp. 15063-15070.
|Titolo:||Phase transitions in a spin-1 model with plaquette interaction on the square lattice|
|Data di pubblicazione:||1996|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevB.53.15063|
|Appare nelle tipologie:||1.1 Articolo in rivista|