Low-Temperature Anomaly in the Josephson Critical Current of Junctions in {ital d}-Wave Superconductors

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.77.4070· OSTI ID:389400

Barash, Y S; Burkhardt, H; Rainer, D ^[1]

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1. P. N. Lebedev Physics Institute, Leninsky Prospect 53, Moscow 117924 (Russia)

We show that the Josephson critical current increases rapidly with decreasing temperature near {ital T}=0 for tunnel junctions between anisotropic superconductors. The enhancement of the critical current has its physical origin in the midgap states bound to the tunnel barrier which are a consequence of the changes in sign of the order parameter along the Fermi surface. The effect depends on the crystal orientations of the superconducting electrodes with respect to the barrier. For some orientations we find a transition from a traditional 0 junction to the unconventional {pi} junction with decreasing temperature. The Josephson critical current diverges, formally, in the zero-temperature limit for an ideally specular tunnel barrier with a small transparency. The actual magnitude of the zero-temperature peak in a realistic junction is shown to be sensitive to the barrier transparency and barrier roughness, which broaden the midgap delta peak in the density of states. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 389400
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 19 Vol. 77; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOUND STATES
CRITICAL CURRENT
D WAVES
ENERGY GAP
JOSEPHSON JUNCTIONS
ORDER PARAMETERS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TEMPERATURE ZERO K