Multilayer edge SNS SQUIDs for digital circuits

Author

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

Author_Institution

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

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3613

Lastpage

3616

Abstract

We have fabricated and characterized direct-injection High Temperature Superconducting (HTS) SQUIDs using a six-epitaxial-layer process which integrates edge geometry superconductor-normal-superconductor (SNS) junctions with an HTS ground plane. The period of the SQUID threshold curves was used to infer microstrip inductances of approximately 1 pH//spl square/ at 65 K. Total SQUID inductances as low as /spl ap/5 pH were inferred from the measured critical current modulation depth. A novel junction geometry was used in some devices to reduce the parasitic inductances of the junction leads by approximately 1 pH. Maintaining such low inductances is particularly important for Single Flux Quantum digital circuits.

Keywords

SQUIDs; high-temperature superconductors; superconducting epitaxial layers; HTS ground plane; SFQ digital circuit; critical current modulation depth; direct injection; epitaxial layer; inductance; microstrip inductance; multilayer edge SNS SQUID; parasitic inductance; Current measurement; Digital circuits; Geometry; High temperature superconductors; Josephson junctions; Land surface temperature; Microstrip; Nonhomogeneous media; SQUIDs; Superconducting devices;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.622188

Filename

622188