Suppression of the Josephson current through a narrow, mesoscopic, semiconductor channel by a single impurity

Journal Article · Sun Nov 15 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.12573· OSTI ID:6946928

Bagwell, P F ^[1]

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1. School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

We study the Josephson current through a ballistic, normal, one-dimensional quantum channel in contact with two superconducting electrodes. A single point impurity having reflection coefficient {ital R} is placed in the normal conductor. The impurity couples the Andreev energy levels of forward and reverse moving electrons inside the junction, opening energy gaps in the quasiparticle level spectrum versus superconducting phase difference {phi}. These Andreev'' energy gaps suppress the Josephson current in much the same way as disorder suppresses the magnetic flux driven currents in a normal mesoscopic ring. Finite-temperature energy averages'' the contribution of Andreev levels above the Fermi energy with those below {mu}, further suppressing the Josephson current. The portion of the Josephson current carried by scattering states outside the superconducting gap is similarly suppressed by disorder and finite temperature.

• OSTI ID: 6946928
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:19; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRODES
ENERGY
ENERGY LEVELS
FERMI LEVEL
FREE ENERGY
IMPURITIES
INHIBITION
JOSEPHSON EFFECT
JUNCTIONS
MATERIALS
ONE-DIMENSIONAL CALCULATIONS
PHYSICAL PROPERTIES
SCATTERING
SEMICONDUCTOR MATERIALS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES