Superconducting contacts to a two-dimensional electron gas in GaAs/AlGaAs-heterostructures

Author

Lenssen, K.-M.H. ; Matters, M. ; Harmans, C.J.P.M. ; Mooij, J.E. ; Leys, M.R. ; van der Vleuten, W. ; Wolter, J.H.

Author_Institution

Dept. of Appl. Phys., Delft Univ. of Technol., Netherlands

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

1961

Lastpage

1963

Abstract

The process of Sn/Ti-diffusion is shown to provide low-resistance (highly transmissive) contacts to the two-dimensional electron gas (2DEG) in GaAs/AlGaAs-heterostructures. At temperatures down to 80 mK the resistance stays very low. The temperature and gate-voltage dependence of the dV/dl-V-curves shows that Andreev reflection must take place in the sample. The measurements suggest that Ti is the relevant superconductor and not Sn. The fact that the bottom of the low-resistance region is very flat and does not show a peak near V=0 V means that the transmission of the NS (normal metal-superconductor) interface is very close to 1. Therefore these superconducting contacts seem to be very suitable for studying SNS (superconductor-normal metal-superconductor) junctions in the clean limit.<>

Keywords

III-V semiconductors; aluminium compounds; gallium arsenide; high electron mobility transistors; superconducting junction devices; two-dimensional electron gas; 2DEG; Andreev reflection; GaAs-AlGaAs; GaAs/AlGaAs-heterostructures; NS interface; SNS junctions; Sn contact; Ti contact; clean limit; gate-voltage dependence; low resistance contacts; normal metal superconductor interface; resistance; superconducting contacts; temperature dependence; transmission; two-dimensional electron gas; Charge carrier processes; Electrical resistance measurement; Electrodes; Electrons; FETs; Gallium arsenide; Inorganic materials; Physics; Superconducting devices; Superconducting materials;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.233575

Filename

233575