Perturbation expansion for the diluted two-dimensional XY model

Oleksandr Kapikranian (1, 2) , Bertrand Berche (2) , Yurij Holovatch (1, 3)

1 ICMP - Institute for Condensed Matter Physics of NAS of Ukraine
2 LPM - Laboratoire de physique des matériaux
3 Institut für Theoretische Physik

We study the quasi-long-range ordered phase of a 2D XY model with quenched site-dilution using the spin-wave approximation and expansion in the parameter which characterizes the deviation from completely homogeneous dilution. The results, obtained by keeping the terms up to the third order in the expansion, show good accordance with Monte Carlo data in a wide range of dilution concentrations far enough from the percolation threshold. We discuss different types of expansion.

Mots clés: XY model; topological transition; random systems

Domaines: Mécanique statistique [cond-mat.stat-mech]

Oleksandr Kapikranian, Bertrand Berche, Yurij Holovatch. Perturbation expansion for the diluted two-dimensional XY model. 2006. ⟨hal-00116869⟩