High-resistance HTS edge junctions for digital circuits

Author

Hunt, B.D. ; Forrester, M.G. ; Talvacchio, J. ; Young, R.M.

Author_Institution

Northrop Grumman Sci. & Technol. Center, Pittsburgh, PA, USA

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

3362

Lastpage

3365

Abstract

We have investigated factors affecting the resistance of edge-geometry HTS weak links, including SNS junctions with Co-doped Y-Ba-Cu-O as a normal metal interlayer. We have also studied devices with no deposited interlayer in which the weak link is produced by ion beam surface damage or by controlled disorder near the base electrode-counterelectrode interface. For each of these weak links several parameters, including the base electrode material and the deposition conditions of the normal metal and counterelectrode, are found to have strikingly large effects on device resistance. Controlling these factors has enabled the fabrication of high-quality, high-resistance (/spl ap/1 Ohm) SNS edge junctions with one-sigma I/sub c/ spreads down to 6% in 10-junction series arrays. The junctions without deposited interlayers exhibit electrical characteristics and parameter spreads approaching the best results obtained with the Co-YBCO SNS devices.

Keywords

Josephson effect; barium compounds; critical current density (superconductivity); high-temperature superconductors; ion beam effects; superconducting arrays; superconducting logic circuits; superconductor-normal-superconductor devices; yttrium compounds; HTS edge junctions; SNS junctions; YBa/sub 2/Cu/sub 3/CoO/sub 7/; base electrode-counterelectrode interface; controlled disorder; deposition conditions; device resistance; digital circuits; edge-geometry weak links; electrical characteristics; ion beam surface damage; one-sigma I/sub c/ spreads; parameter spreads; series arrays; Digital circuits; Electric resistance; Electric variables; Electrodes; Fabrication; High temperature superconductors; Inorganic materials; Ion beams; Surface resistance; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783750

Filename

783750