Harmonic generation from a superconductive thin-film bridge

V. N. Gubanov, V. P. Koshelets, G. A. Ovsyannikov

R. Sobolewski, Charles V. Stancampiano, Gerard A. Mourou +1 more

Brian P. Wilfley

Harris Notarys, James E. Mercereau

Techniques have been developed with which it is possible to fabricate superconducting thin-film structures with a wide variety of electrical and superconducting parameters which show Josephson-like phenomena. These bridges-based on the proximity effect-are made in layered thin-film ``substrates'' using a large variety of superconducting and nonsuperconducting materials. In this paper we detail the fabrication techniques and the electrical and superconducting characteristics for these proximity effect bridges including a simple low-frequency (<10 GHz) equivalent circuit based on analysis and experiment which closely describes the quantum phase coherence operation of the bridges in their voltage sustaining state. Extension of these fabrication techniques to entire thin-film electrical circuits including resistors, capacitors, and inductors with these bridges and leading to an entire superconducting microcircuit technology is discussed.

National Research Council

Yoshinori Uzawa, Etsuo Kawate, Nobumitsu Hirose +5 more

All-niobium thin-film nanobridges were fabricated with bridge sizes of 40-nm length, 50-nm width, and 100-nm thickness. We investigated the performance of the nanobridges by monitoring Shapiro steps induced on the current-voltage curves by an optically pumped far-infrared laser. These steps have been observed up to 693 GHz (433 μm). This is a twofold increase over that previously reported on thin-film nanobridges.