Effect of Charging Energy on Kosterlitz-Thouless Transition Temperature in Granular Films

Abstract

A relationship between the Kosterlitz-Thouless transition temperature $T_{\mathrm{KT}}$ and the sheet resistance ${R_{\square }}^N$ of a granular superconducting film is derived taking into account the electrostatic charging energy. The zero-point phase fluctuations produce a drop of the areal superfluid density at a critical value of the sheet resistance in agreement with the recent observation on granular lead films.