Extraction of impacts of fabrication spread and thermal noise on operation of superconducting digital circuits

Author

Semenov, V.K. ; Polyakov, Yu.A. ; Wei Chao

Author_Institution

State Univ. of New York, Stony Brook, NY, USA

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

4030

Lastpage

4033

Abstract

We have developed a procedure to investigate and distinguish several disturbing influences on an RSFQ circuit such as thermal noise, flux trapping and fabrication spread. The procedure is applied to a slightly modified RSFQ shift register with 3 independent dc biases, which are common for all cells. One of the biases performs a special function. Nominally it is equal to zero and used only to create a controllable effect on the operation of the circuit. The impact of different factors is extracted from their interference with the special bias. It has been found that the influence of thermal noise in the best samples fabricated at HYPRES, Inc. is comparable with that of fabrication spread even for low (/spl sim/4 K) operational temperature.

Keywords

critical current density (superconductivity); flux pinning; integrated circuit noise; shift registers; superconducting device noise; superconducting logic circuits; thermal noise; 4 K; HYPRES; RSFQ circuit; controllable effect; fabrication spread; flux trapping; independent dc biases; operational temperature; shift register; superconducting digital circuits; thermal noise; Chaos; Circuit noise; Circuit testing; Critical current; Current measurement; Digital circuits; Fabrication; Josephson junctions; Shift registers; Superconducting device noise;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783912

Filename

783912