Evaluation of niobium transmission lines up to the superconducting gap frequency

Dierichs, M. M. T. M. ; Feenstra, B. J. ; Skalare, A. ; Honingh, C. E. ; Mees, J. ; Stadt, H.v.d. ; Graauw, Th. de

Woodbury, NY : American Institute of Physics (AIP)
Published 1993
ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The frequency dependence of the coupling of niobium superconducting transmission lines is measured for frequencies up to and above the superconducting gap frequency. For this purpose superconducting microstrips are integrated in log-periodic planar antennas and the spectral response is measured by means of a Fourier transform spectrometer with 1 μm2 Nb/Al2O3/Nb SIS junctions as detectors. Resonances of microstrips are observed up to 650 GHz, the superconducting gap frequency of niobium, but above that frequency no resonances have been detected. The measured resonance frequencies are in good agreement with a dispersive model for superconducting transmission lines based on the Mattis–Bardeen theory. The radiation coupling is lower than calculated, indicating significant dielectric losses.
Type of Medium:
Electronic Resource
URL: