# Groupe de Physique Statistique

## Equipe 106, Institut Jean Lamour

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### Articles dans des revues à comité de lecture

 Interplay of topological and structural defects in the 2D XY model Kapikranian O., Berche B. and Holovatch Yu. Phys. Lett. A 372 (2008) 5716-5721 DOI : 10.1016/j.physleta.2008.06.087 ArXiv : arxiv:0803.1938 [PDF] The present work is devoted to the investigation of the interaction between vortices (topological defects) and site-impurities (structural defects) in the $2D$ $XY$ model and its influence on the well-known properties of the pure system. The main goal is a theoretical description of the Berezinski-Kosterlitz-Thouless (BKT) temperature reduction by quenched non-magnetic impurities, based on the vacancy-vortex interactions and the vortex-pair dissociation mechanism of the transition. The non-magnetic impurity interaction with a system of vortices can be found either from the theory of topological defects or from the Villain model. We take the both pathes and compare the obtained results. Our prediction for the BKT temperature reduction is compared to the available Monte Carlo data.