title: Role of topological defects in the phase transition of a modified XY model: a Monte Carlo study.
abstract: Monte Carlo simulation has been performed on a classical two-dimensional XY model with a modified form of interaction potential to investigate the role of topological defects on the phase transition exhibited by the model. In simulations in a restricted ensemble without defects, the system appears to remain ordered at all temperatures. Suppression of topological defects on the square plaquettes in the modified XY model leads to complete elimination of the phase transition observed in this model.
authors.affiliation: Department of Physics, Jadavpur University, Kolkata 700032, India. ssinha@research.jdvu.ac.in
authors.forename: Suman
authors.initials: S
authors.lastname: Sinha
authors.forename: Soumen Kumar
authors.initials: SK
authors.lastname: Roy