title: Nonuniversal behavior of the helicity modulus in a dense defect system.
abstract: An extensive Monte Carlo simulation has been performed on a two-dimensional modified XY model that behaves like a dense defect system. Topological defects are shown to introduce disorder in the system, which makes the helicity modulus jump nonuniversal. The results corroborate the experimental observation of a nonuniversal jump of the superconducting density in high-Tc superconducting films.
authors.affiliation: Theoretical Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India. suman.sinha@saha.ac.in
authors.forename: Suman
authors.initials: S
authors.lastname: Sinha