ABSTRACTWe have examined the photoresponse of two-dimensional granular superconducting films of high Tc superconductors (Y-Ba-Cu-O). We see evidence for the existence of a twodimensional Kosterlitz-Thouless transition. The photoresponse and resistance have been measured as a functions of temperature, excitation power, bias current, and photon energy. The response to photons having energies above and below the superconducting energy gap(s) has been measured. Photoresponse features have been observed that are not explainable in terms of a conventional phonon bolometric mechanism. Comparison will be made with similar observations made on low temperature superconducting films (NbN-BN).
Effect of Thermal Phase Fluctuations on the Superfluid Density of Two-Dimensional Superconducting Films
