High T/sub c/ dc SQUID utilizing bicrystal junctions with 30 degree misorientation angle

Author

Enpuku, K. ; Minotani, T. ; Shiraishi, F. ; Kandori, A. ; Kawakami, S.

Author_Institution

Dept. of Electron. Device Eng., Kyushu Univ., Fukuoka, Japan

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

3109

Lastpage

3112

Abstract

Performances of high T/sub c/ dc SQUID utilizing bicrystal junctions with 30/spl deg/ misorientation angle have been studied. Junction resistance R/sub s/=10 /spl Omega/ and critical current I/sub 0/=10-20 /spl mu/A can be obtained rather easily at T=77 K with this technology. As a result, voltage modulation depth as high as 50 /spl mu/V, and flux noise as low as 5 /spl mu//spl Phi//sub 0//Hz/sup 1/2/ obtained for the 100 pH-SQUID. The measured values of the voltage modulation depth agree reasonably well with the numerical simulation, while the measured values of the flux noise are about 2 or 3 times larger than the simulation. The reason for the high noise level is discussed by taking into account imperfection of junctions.

Keywords

SQUIDs; bicrystals; high-temperature superconductors; superconducting device noise; DC SQUID; bicrystal junction; critical current; flux noise; high T/sub c/ superconductor; misorientation angle; numerical simulation; surface resistance; voltage modulation depth; Circuit noise; Circuit simulation; Frequency; Inductance; Low-frequency noise; Noise measurement; Numerical simulation; SQUIDs; Transfer functions; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783687

Filename

783687