Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 15: Superconductivity - Tunneling, Josephson Junctions, SQUIDs

TT 15.2: Vortrag

Dienstag, 27. März 2007, 14:15–14:30, H20

Coupling mechanism of a mm wave radiation to Josephson junctions in an open resonator — •A. M. Klushin, M. He, M. Kurochka, and N. Klein — Institute of Bio- and Nanosystems and CNI-Centre of Nanoelectronic Systems for Information Technology Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany

We have explored the coupling mechanism of a millimeter wave radiation to bicrystal Josephson junction arrays embedded in a hemispherical Fabry-Perot resonator [1]. We have found that our high-temperature superconductor array can be modeled as a thin film grid polarizer. In agreement with this model, a strong dependence of the coupling of the Josephson junctions on the polarization of the electric filed in the resonator was observed. We achieved a maximum Josephson voltage about 30 mV for an array of 182 bicrystal junctions at a temperature of 75K and a frequency of 75 GHz. Our results showed that such circuits are challenging for application in a quantum voltage metrology. It is important to note that our quasioptical coupling method can be extended up to terahertz frequencies. Here, our approach appears very promising for the realization of THz sources and detector arrays. Finally, our approach could be useful for irradiation of large arrays of niobium Josephson junctions as well. In this case, a substantial simplification of the technology of niobium arrays, and an increase of the irradiation frequency could be achievable.

[1] Appl. Phys. Lett. 89, 232505 (2006)