Determination of the coherence length in high-mobility semiconductor-coupled Josephson weak links

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.348433· OSTI ID:5843393

Kleinsasser, A W ^[1]

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1. IBM Research Division, T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (US)

A Nb-InAs-Nb superconductor-semiconductor-superconductor weak link based on a high-mobility homoepitaxial {ital n}-InAs film was reported recently (Akazaki, Kawakami, and Nittu J. Appl. Phys. {bold 66}, 6121 (1989)). Measurements of the electron concentration, effective mass, and mobility allowed the coherence length in the normal link to be calculated. The mobility was high enough that the dirty limit was not applicable in the temperature range ({similar to}2--7 K) over which the device critical current was measured. The temperature dependence of the critical current could not be fit by the usual theoretical form, even though an expression for the coherence length was used that should be applicable in both the clean and dirty limits. In this paper is demonstrated an excellent fit to the data, obtained by using the magnitude of the coherence length as a fitting parameter and assuming the dirty limit temperature dependence. This implies a coherence length proportional to {ital T}{sup {minus}1/2} but far shorter than that calculated from the known material parameters. It is suggested that a different scaling length may apply in high-mobility devices.

• OSTI ID: 5843393
• Journal Information: Journal of Applied Physics; (USA), Vol. 69:7; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
JOSEPHSON JUNCTIONS
CRITICAL CURRENT
ELECTRON MOBILITY
COHERENCE LENGTH
SEMICONDUCTOR JUNCTIONS
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE
CURRENTS
DIMENSIONS
ELECTRIC CURRENTS
JUNCTIONS
LENGTH
MOBILITY
PARTICLE MOBILITY
426001* - Engineering- Superconducting Devices & Circuits- (1990-)
656100 - Condensed Matter Physics- Superconductivity