SFQ-to-level logic conversion by HTS Josephson drivers for output interface

Author

Hato, Tsunehiro ; Ishimaru, Yoshihiro ; Harada, Naoki ; Horibe, Masahiro ; Yoshida, Akira ; Tarutani, Yoshinobu ; Tanabe, Keiichi ; Yokoyama, Naoki

Author_Institution

Fujitsu Ltd., Atsugi, Japan

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

397

Lastpage

400

Abstract

Latching-type driver circuits integrated with high-temperature superconductivity (HTS) junctions and two types of resistor were fabricated. These circuits could successfully perform latching operation by means of a single-flux-quantum (SFQ) signal input. Ramp-edge-type HTS junctions were fabricated by interface engineering and showed a hysteretic current-voltage characteristics under a temperature of 50 K. The critical current (I_c) of these 5-micron-wide junctions was about 0.2 mA and the I_cR_n product was about 1.7 mV at 4.2 K. The circuits included two types of resistors, which were made of RF-magnetron-sputtered indium-tin-oxide (ITO) and Au films. A driver with a parallel 2-junction-stack could convert an SFQ pulse, which was transformed through several Josephson transmission lines (JTL´s) from a DC/SFQ circuit, to a 2.3-mV level signal.

Keywords

Josephson effect; convertors; critical currents; driver circuits; high-temperature superconductors; superconducting logic circuits; 0.2 mA; 1.7 mV; 2.3 mV; 5 micron; 50 K; Au films; HTS Josephson drivers; ITO-Au; InSnO-Au; Josephson transmission lines; RF-magnetron-sputtered ITO; SFQ-to-level logic conversion; critical current; high-temperature superconductivity junctions; hysteretic current-voltage characteristics; latching operation; latching-type driver circuits; output interface; parallel 2-junction-stack; ramp-edge-type HTS junctions; single-flux-quantum signal input; Critical current; Current-voltage characteristics; Driver circuits; Gold; High temperature superconductors; Hysteresis; Indium tin oxide; Josephson junctions; Resistors; Superconductivity;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.813867

Filename

1211625