Investigation of ramp-type Josephson junctions with surface-modified barriers

Author

Soutome, Y. ; Hanson, R. ; Fukazama, T. ; Saitoh, K. ; Tsukamoto, A. ; Tarutani, Y. ; Takagi, K.

Author_Institution

Adv. Res. Lab., Hitachi Ltd., Kokubunji, Japan

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

163

Lastpage

166

Abstract

We have investigated the properties of YBa₂Cu₃O_7-x ramp-edge Josephson junctions with surface-modified barriers produced by Ar-ion irradiation followed by oxygen annealing. The fabricated junctions displayed RSJ-like I-V characteristics and excellent uniformity. The stray capacitance of the junctions was estimated from the ramp-edge structure. The junction capacitance was obtained by subtracting the stray capacitance from the shunting capacitance. We estimated the barrier thickness from the junction capacitance, and found that the critical current density of the junction increased exponentially with decreasing barrier thickness. The relative dielectric constant of the barriers ranged from 13 to 18

Keywords

Josephson effect; annealing; barium compounds; capacitance; critical current density (superconductivity); high-temperature superconductors; ion beam effects; permittivity; sputter etching; superconducting junction devices; superconducting thin films; yttrium compounds; Ar-ion irradiation; RSJ-like I-V characteristics; YBa₂Cu₃O_7-x ramp-edge Josephson junctions; YBa₂Cu₃O₇; barrier thickness; critical current density; junction capacitance; oxygen annealing; ramp-edge structure; relative dielectric constant; shunting capacitance; stray capacitance; surface-modified barriers; uniformity; Annealing; Capacitance; Dielectric constant; Etching; Fabrication; High temperature superconductors; Josephson junctions; Laboratories; Plasma temperature; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919310

Filename

919310