Observations of quasi-particle tunneling and Josephson behavior in Y sub 1 Ba sub 2 Cu sub 3 O sub 7 minus x / native barrier/Pb thin-film junctions

Journal Article · Mon Feb 19 00:00:00 EST 1990 · Applied Physics Letters; (USA)

DOI:https://doi.org/10.1063/1.103318· OSTI ID:7171447

Kwo, J; Fulton, T A; Hong, M; Gammel, P L ^[1]

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1. AT T Bell Laboratories, Murray Hill, New Jersey 07974 (US)

Low-leakage, thin-film planar tunnel junctions made of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}}/ native barrier/Pb were fabricated. The Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} films were prepared by {ital in} {ital situ} molecular beam epitaxy aided with an activated oxygen source. The as-grown, smooth superconducting perovskite film surface exhibits quasi-particle tunneling characteristics very similar to the etched bulk single-crystal data. The results in agreement are a linear dependence of the normal-state conductance on voltage, a gap-like structure at {similar to}20 mV, asymmetric modulations up to 50 mV, and a finite zero-bias conductance at low temperature. Junctions of lower resistance show, at temperatures below {ital T}{sub {ital c}} of Pb, the development of a supercurrent at zero bias and associated hysteretic subgap structure, with a typical {ital I}{sub {ital c}}{ital R} {similar to}0.5 mV. Josephson-like behavior occurred in response to applied magnetic field and microwaves.

• OSTI ID: 7171447
• Journal Information: Applied Physics Letters; (USA), Vol. 56:8; ISSN 0003-6951
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
SUPERCONDUCTIVITY
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SUPERCONDUCTING JUNCTIONS
FABRICATION
YTTRIUM OXIDES
EXPERIMENTAL DATA
JOSEPHSON EFFECT
LEAD
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BARIUM COMPOUNDS
CHALCOGENIDES
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ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
INFORMATION
JUNCTIONS
METALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
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