Critical Josephson current in a model Pb/YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} junction

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.6894· OSTI ID:115839

Atkinson, W A; Carbotte, J P ^[1]

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1. Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada)

We consider a simple model for a {ital c}-axis Pb/YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} Josephson junction. The observation of a nonzero current in such a junction by Sun {ital et} {ital al}. [Phys. Rev. Lett. 72, 2267 (1994)] has been taken as evidence against {ital d}-wave superconductivity in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. We suggest, however, that the pairing interaction in the CuO{sub 2} planes may well be {ital d} wave but that the CuO chains destroy the tetragonal symmetry of the system. We examine two ways in which this happens. In a simple model of an incoherent junction, the chains distort the superconducting condensate away from {ital d}{sub {ital x}}{sup 2}{minus}{ital y}{sup 2} symmetry. In a specular junction the chains destroy the tetragonal symmetry of the tunneling matrix element. In either case, the loss of tetragonal symmetry results in a finite Josephson current. Our calculated values of the critical current for specular junctions are in good agreement with the results of Sun and co-workers.

• OSTI ID: 115839
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 52; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
D WAVES
HIGH-TC SUPERCONDUCTORS
JOSEPHSON JUNCTIONS
PAIRING INTERACTIONS
TETRAGONAL LATTICES
YTTRIUM OXIDES