Superconductor{endash}normal{endash}superconductor step-edge junctions with Au barriers

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.363715· OSTI ID:389268

Bode, M; Grove, M; Siegel, M; Braginski, A I ^[1]

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1. Institut fuer Schicht- und Ionentechnik, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany)

YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} superconductor{endash}normal{endash}superconductor junctions in step-edge geometry are fabricated by an {ital in} {ital situ} process using off-axis sputter deposition. Gold is used as the normal metal interlayer. A special inhibiting layer is introduced to ensure proper separation of the superconducting electrodes. The temperature dependence of the critical current {ital I}{sub {ital c}} is nearly linear. The junctions show high normal resistances up to {ital R}{sub {ital N}}=10 {Omega} and high {ital I}{sub {ital c}}{ital R}{sub {ital N}} products up to 8.8 mV at 4.2 K. {ital I}{endash}{ital V} characteristics exhibit a large excess current {ital I}{sub ex} over the whole temperature range, even for electrically narrow junctions. The power dependence of Shapiro step heights shows characteristic deviations from the resistively and capacitively shunted junction model. Calculations using the time-dependent Ginzburg{endash}Landau equations are carried out to model the measured {ital I}{endash}{ital V} characteristics with and without microwave irradiation. A point-contact-like superconductor{endash}constriction{endash}superconductor model is suggested to explain the excess current and the measured temperature dependence of {ital I}{sub {ital c}} and {ital I}{sub ex}. Time-dependent Ginzburg{endash}Landau equations are used to account for the observed dynamic characteristics. {copyright} {ital 1996 American Institute of Physics.}

• OSTI ID: 389268
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 80; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
FABRICATION
GINZBURG-LANDAU THEORY
GOLD
HIGH-TC SUPERCONDUCTORS
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE
YTTRIUM OXIDES