Is The Vortex-Antivortex Transition Temperature of a Thin-Film Superconductor Renormalized by Disorder?
01 January 1989
The universal relation between the Kosterlitz-Thouless transition temperature Tc and the superfluid sheet density of thin-film superconductors with mean-field transition temperature Tc0 results in a monotonically decreasing dependence of the ratio Tc /Tc0 on the normal-state sheet resistance Rn. Ambiguity in the experimental definition of Rn in highly disordered thin- film superconductors is addressed by reexamining previously published data on amorphous composite In/InOx films. Arguments are presented in favor of using the zero temperature value of Rn, a quantity obtained by extrapolation. The dependence of Tc /Tc0 on Rn that results from such a choice is in agreement with theory for dirty superconductors and thus suggests that additional corrections to Tc in the presence of extreme disorder are not required. PACS numbers: