Transmission line high-T/sub c/ dc-SQUIDs

Author

Kuriki, S. ; Oyama, H. ; Maruyama, E. ; Hayashi, A. ; Hirano, S. ; Suzuki, D. ; Koyanagi, M.

Author_Institution

Res. Inst. for Electron. Sci., Hokkaido Univ., Sapporo, Japan

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

3275

Lastpage

3278

Abstract

Because of high permittivity of SrTiO/sub 3/ (STO) substrate, YBCO high-Tc SQUIDs have distributed impedance. Based on the simulation by the analytical method to calculate the I-V characteristic, we have designed and fabricated YBCO dc SQUIDs that have a transmission-line-like geometry of thin parallel strips with a wide slit between them. The geometrical parameters were determined to give high modulation voltage. The fabricated SQUIDs had a white noise of (0.5-1.0)/spl times/10 /spl Phi//sub 0//Hz/sup 1/2/. We also designed a direct coupling magnetometer, in which the transmission line SQUID was located within the hole of the pickup coil. On a small substrate area of 5 mm/spl times/10 mm, the fabricated magnetometer had an effective area of 0.22 mm/sup 2/. The field noise of about 100 fT/Hz/sup 1/2/ was obtained in the white noise region.

Keywords

SQUID magnetometers; SQUIDs; barium compounds; high-temperature superconductors; superconducting device noise; superconducting transmission lines; white noise; yttrium compounds; I-V characteristics; STO substrate; SrTiO/sub 3/; YBCO high-Tc DC-SQUID; YBaCuO; direct coupling magnetometer; distributed impedance; flux coupling efficiency; permittivity; pickup coil; simulation; transmission line; white noise; Analytical models; Geometry; Impedance; Permittivity; SQUID magnetometers; Solid modeling; Strips; Transmission lines; White noise; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783728

Filename

783728