The ac‐Josephson effect above the gap frequency
| Autor: | R. A. Panhuyzen, J. J. Kuipers, T. M. Klapwijk, M. W. M. de Graauw, H. van de Stadt, G. de Lange |
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| Přispěvatelé: | Applied Physics |
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: |
Josephson effect
Superconductivity Physics Waveguide (electromagnetism) Condensed matter physics Terahertz radiation RANGE General Physics and Astronomy Condensed Matter::Mesoscopic Systems and Quantum Hall Effect EFFECT VOLTAGE STANDARD Diffusion capacitance NOISE Pi Josephson junction SUPERCONDUCTING TUNNEL-JUNCTIONS Condensed Matter::Superconductivity Superconducting tunnel junction Stripline |
| Zdroj: | Journal of Applied Physics, 76(12), 8016-8021. AMER INST PHYSICS |
| ISSN: | 0021-8979 |
| Popis: | The rf‐power dependence of the ac‐Josephson steps is measured at 720 GHz, using small area Nb tunnel junctions. This frequency is well above the gap frequency of Nb. The junction is placed in a waveguide, and connected to a superconducting stripline, which effectively tunes out the junction capacitance and facilitates the coupling of the radiation to the junction. We observe three Josephson steps, and the first step crosses the zero current axis over a considerable range of rf‐power. This indicates the possible application of THz Josephson steps in voltage standards. The data are compared to the theory and we find clear evidence for the predicted intrinsic roll‐off of the Josephson current amplitude above the gap frequency. |
| Databáze: | OpenAIRE |
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