Design and fabrication of QFP logic gates based on YBa/sub 2/Cu/sub 3/O/sub 7/ step-edge junctions

Author

Hasegawa, H. ; Tarutani, Y. ; Kabasawa, U. ; Sugii, N. ; Fukazawa, T. ; Takagi, K.

Author_Institution

Central Res. Lab., Hitachi Ltd., Tokyo, Japan

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3446

Lastpage

3449

Abstract

Quantum Flux Parametron (QFP) logic gates were designed and fabricated from a single layer of YBa/sub 2/Cu/sub 3/O/sub 7/ thin film based on step-edge Josephson junctions. Self-inductance (L) of the QFP loop, an important circuit parameter, as is critical current (J/sub c/) of the Josephson junction, was determined by using directly coupled dc superconducting quantum interference devices (SQUIDs). Magnetically coupled dc SQUIDs were used to detect the output signal from the QFP. Simulated waveforms were used to identify the operation modes of the QFP as a function of the circuit parameters. From examination of the output waveforms of the QFP, operation in agreement with simulations was confirmed.

Keywords

Josephson effect; SQUIDs; barium compounds; high-temperature superconductors; logic gates; superconducting logic circuits; superconducting thin films; yttrium compounds; QFP logic gate; YBa/sub 2/Cu/sub 3/O/sub 7/; YBa/sub 2/Cu/sub 3/O/sub 7/ thin film; critical current; design; directly coupled DC SQUID; fabrication; quantum flux parametron; self-inductance; step-edge Josephson junction; waveform simulation; Circuit simulation; Coupling circuits; Electronics packaging; Fabrication; Josephson junctions; Logic design; Logic gates; SQUIDs; Superconducting thin films; Thin film circuits;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.622127

Filename

622127