Two-dimensional ising model with competing interactions : floating phase, walls and dislocations
Year: 1981
Type: article
Abstract: A two-dimensional, anisotropic Ising model with competing interactions (Selke's « ANNNI» model) is studied by analytic methods. As a first approximation the system is described as a sequence of infinite stripes of positive and negative spins separated by « walls ». The phase diagram exhibits three phases : the ferromagnetic phase, a phase with two « up » layers followed by two « down » layers, and so on, and a « floating » phase with continuously varying wave vector. If dislocations of the wall array are taken into account an additional, paramagnetic phase appears. The paramagnetic phase is argued to extend down to zero temperature in disagreement with results deduced from computer simulations by Selke and Fisher. The present results are in strong contrast with those obtained in the corresponding three-dimensional model which exhibits an infinity of locked, commensurate phases.
Source: Journal de physique
Authors: J. Villain, P. Bak
Institutions: CEA Grenoble, University of Copenhagen
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1986977896