NbN/AlN/NbN tunnel junctions with high current density up to 54 kA/cm{sup 2}

Journal Article · Wed Jan 01 00:00:00 EST 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.119279· OSTI ID:435083

Wang, Z; Kawakami, A; Uzawa, Y ^[1]

---

1. Kansai Advanced Research Center, Communications Research Laboratory, Ministry of Posts and Telecommunications, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Kobe 651-24 (Japan)

We report on progress in the development of high current density NbN/AlN/NbN tunnel junctions for applications as submillimeter wave superconductor-insulator-superconductor mixers. A very high current density up to 54 kA/cm{sup 2}, roughly an order of magnitude larger than any reported results for all-NbN tunnel junctions, was achieved in the junctions with about 1 nm thick AlN barriers. The magnetic field and temperature dependence of critical supercurrents were measured to investigate the Josephson tunneling behavior of critical supercurrents in the high-J{sub c} junctions. The junctions showed high-quality junction characteristics with a large gap voltage of 5 mV and sharp quasiparticle current rise ({Delta}V{sub g}=0.1 mV). The R{sub sg}/R{sub N} ratio was about 5 with a V{sub m} value of 14 mV measured at 4.2 K. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 435083
• Journal Information: Applied Physics Letters, Vol. 70, Issue 1; Other Information: PBD: Jan 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
36 MATERIALS SCIENCE
SUPERCONDUCTING JUNCTIONS
MIXERS
NIOBIUM NITRIDES
TUNNEL EFFECT
NIOBIUM COMPOUNDS
NITROGEN COMPOUNDS
ALUMINIUM COMPOUNDS
SUPERCONDUCTING DEVICES
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
ALUMINIUM NITRIDES
CRITICAL CURRENT
MAGNETIC FIELDS
MICROWAVE RADIATION
TEMPERATURE DEPENDENCE
CURRENT DENSITY