Current-voltage relation of a normal-metal--superconductor junction

Journal Article · Mon Nov 15 04:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.15198· OSTI ID:5680398

Riedel, R A; Bagwell, P F ^[1]

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

We calculate the electrical and heat currents flowing through a narrow, mesoscopic, normal-metal--superconductor (NS) junction containing a single point impurity. The NS junction exhibits large subgap conduction steps in its current-voltage ([ital I]-[ital V]) relation when the impurity is located in the normal metal. Our new subgap step appears in the [ital I]-[ital V] characteristic whenever an additional quasiparticle is trapped between the impurity and NS interface. Locating the impurity inside the superconductor produces both an excess current'' and oscillations in the [ital I]-[ital V] characteristic analogous to the Tomasch effect. A maximum excess current of 2[ital e][Delta]/[ital h], slightly less than the 8[ital e][Delta]/3[ital h] found for a ballistic NS junction obtains when the impurity is located a few coherence lengths inside the superconductor.

• OSTI ID: 5680398
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:20; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BCS THEORY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
JUNCTIONS
PHYSICAL PROPERTIES
SUPERCONDUCTING JUNCTIONS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TUNNEL EFFECT