factor and resonance amplitude of Josephson tunnel junctions
- 1 October 1977
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 16 (7), 3100-3107
- https://doi.org/10.1103/physrevb.16.3100
Abstract
The surface impedance of the superconducting films comprising the electrodes of Josephson tunnel junctions has been derived from the BCS theory in the extreme London limit. Expressions have been obtained for (i) the dependence of the penetration depth on frequency and temperature, and (ii) the quality factor of the junction cavity, attributable to surface absorption in the electrodes. The effect of thin electrodes () is also included in the calculations. Comparison of the calculated frequency dependence of with resonance measurements on Pb-alloy and all-Nb tunnel junctions yields quite good agreement indicating that the assumptions made in the theory are reasonable. Measurements of the (current) amplitude of the resonance peaks of the junctions have been compared with the values obtained from inclusion of the calculated in the theory by Kulik. In common with observations on microwave cavities by other workers, we find that a small residual conductivity must be added to the real part of the BCS value. With its inclusion, good agreement is found between calculation and experiment, within the range determined by the simplifying assumptions of Kulik's theory. From the results, we believe the calculation of to be reasonably accurate for the materials investigated. It is shown that the resonance amplitude of Josephson junctions can be calculated direct from the material constants and a knowledge of the residual conductivity.
Keywords
This publication has 21 references indexed in Scilit:
- Metallurgical considerations with respect to electrodes and interconnection lines for Josephson tunneling circuitsJournal of Vacuum Science and Technology, 1976
- Characteristics of in-line Josephson tunneling gatesIEEE Transactions on Magnetics, 1975
- Self-resonant modes in high-Josephson tunnel junctionsPhysical Review B, 1974
- Superconductive tunneling in junctions containing lead-gold layered filmsJournal of Applied Physics, 1974
- Fabrication of experimental Josephson tunneling circuitsJournal of Vacuum Science and Technology, 1974
- Magnetic Flux Penetration into Superconducting Thin FilmsPhysical Review B, 1972
- dc and ac Josephson Effect in Sputtered Nb–NbOx–Pb JunctionsJournal of Applied Physics, 1972
- Surface-resistance measurements in TE011-mode cavities of superconducting indium, lead and an indium-lead alloy at low and high RF magnetic fieldsPhysica, 1971
- Frequency Dependence of the Skin Depth in Superconducting TinJournal of Applied Physics, 1969
- Theory of Electromagnetic Properties of Strong-Coupling and Impure Superconductors. IIPhysical Review B, 1967