High-frequency characterization of thin-film Y-Ba-Cu oxide superconducting transmission lines

Abstract
We report the first measurements of picosecond pulse propagation on transmission lines patterned from YBa2Cu3O7x films. Distortion‐free propagation of high current density transients is demonstrated. The high‐frequency properties were analyzed by careful study of the relative phase delays of the electrical transients as the temperature of the sample was varied from 1.8 K to Tc. Simulations using Mattis–Bardeen complex conductivities showed good agreement with the measured results. High‐frequency critical current densities in excess of 105 A/cm2 were measured.