Regensburg 2002 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 2: Supraleitung: Dünne Schichten, Josephsonkontakte, SQUIDs I
TT 2.7: Vortrag
Montag, 11. März 2002, 12:00–12:15, H19
Microwave Properties of Lumped Arrays of High-Temperature Superconductor Josephson Junctions — •Alexander Klushin1, Konstantin Il’in1, Valentina Gelikonova2, Kai Numssen3, and Michael Siegel1 — 1Institut für Schichten und Grenzflächen, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 2Institute for electronic measurements "KVARZ", 603009, Nizhnii Novgorod, Russia — 3Department of Physics E10, Technical University of Munich, 85748 Garching, Germany
A pulse-driven Josephson junction array is the principal part of an arbitrary voltage waveform synthesizer wich will be useful in quantum ac and dc voltage metrology, communication systems with small phase noise, and calibration of electronic instruments. For the appropriate work of pulse-driven arrays is required to guarantee that every pulse specified by digital code will biased every junction in the array without fail. This can be realized in electrically small arrays if the response of every Josephson junction on the pulse bias current is reasonably independent on frequency from dc up to practically important frequency of about 20GHz. We have investigated arrays of bicrystal junctions with a width from 0.5µ m to 4µ m and a distance between junctions in the meander array from 0.3µ m to 1µ m. Lumped arrays with N=128 junctions have shown full frequency locking by external irradiation up to 25GHz at liquid nitrogen temperature. The challenges related to substantial increasing of number of bicrystal junctions in the lumped arrays will be discussed.