Electrical characterization of Nb/Al-oxide/Nb Josephson junctions with high critical current densities

Author

Kleinsasser, A.W. ; Mallison, W.H. ; Miller, R.E. ; Arnold, G.B.

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2735

Lastpage

2738

Abstract

Transport in Nb/AlO/sub x//Nb junctions involves two parallel channels, barrier defects (pinholes) with sub-nanometer dimensions and nearly-ideal tunneling regions. We fit junction characteristics using only a single parameter, the ratio of the normal state conductances of these current paths. Our barrier model accounts for the excellent Josephson behavior and highly non-ideal quasiparticle characteristics of junctions with critical current densities as high as 4 mA//spl mu/m/sup 2/. It appears to be quite generally applicable to tunnel junctions.<>

Keywords

Josephson effect; aluminium compounds; critical current density (superconductivity); niobium; quasiparticles; superconducting device testing; superconducting junction devices; Andreev reflections; Nb-AlO-Nb; Nb/AlO/sub x//Nb Josephson junctions; barrier defects; electrical characterization; high critical current densities; nearly-ideal tunneling regions; nonideal quasiparticle characteristics; normal state conductance ratio; parallel path model; pinholes; quasiparticle I-V characteristics; subnanometer dimensions; Critical current; Critical current density; Frequency; Hysteresis; Josephson junctions; Laboratories; Niobium; Pressure control; Tunneling; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403156

Filename

403156