Current transport and electronic states in {ital a},{ital b}-axis-oriented YBa{sub 2}Cu{sub 3}O{sub 7}/PrBa{sub 2}Cu{sub 3}O{sub 7}/YBa{sub 2}Cu{sub 3}O{sub 7} sandwich-type junctions

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.8623· OSTI ID:279813

Yoshida, J; Nagano, T; Hashimoto, T ^[1]

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1. Advanced Research Laboratory, Toshiba Corporation, 1, Komukai Toshibacho, Saiwaiku, Kawasaki 210 (Japan)

Precise measurement of the temperature and voltage dependence of junction conductance has been carried out for {ital a},{ital b}-axis-oriented YBa{sub 2}Cu{sub 3}O{sub 7}/PrBa{sub 2}Cu{sub 3}O{sub 7}/YBa{sub 2}Cu{sub 3}O{sub 7} sandwich-type junctions to investigate the possible origin of Josephson coupling in these junctions. Regardless of the presence or absence of the Josephson effect, most of the junctions exhibited a dip in conductance around zero voltage in their {ital dI}/{ital dV} profiles at low temperatures. This {ital dI}/{ital dV} anomaly was attributed to the existence of a minimum in the density of states due to electron-electron interaction in disordered metals in the vicinity of a tunneling barrier within the junctions. The complex temperature dependence of junction conductance was reproduced well by a theoretical model in which both tunneling conduction paths and variable range hopping paths were assumed to exist within the PrBa{sub 2}Cu{sub 3}O{sub 7} barrier layer. No definite evidence of current transport through a small number of localized levels or a metallic conduction path in PrBa{sub 2}Cu{sub 3}O{sub 7} has been confirmed, even for junctions with a 20-nm-thick barrier layer. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 279813
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 13 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM OXIDES
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRON-ELECTRON INTERACTIONS
ENERGY-LEVEL DENSITY
HIGH-TC SUPERCONDUCTORS
JOSEPHSON EFFECT
LOCALIZED STATES
PRASEODYMIUM OXIDES
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE
VOLTAGE DEPENDENCE
YTTRIUM OXIDES