Nb-based superconducting tunnel junctions as submillimeter-wave direct detectors

Author

Ariyoshi, Seiichiro ; Matsuo, Hiroshi ; Otani, Chiko ; Sato, Hiromi ; Shimizu, Hirohiko ; Matsunaga, Teruhiko ; Noguchi, Takashi

Author_Institution

Graduate Univ. for Adv. Studies, Kanagawa, Japan

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

1128

Lastpage

1131

Abstract

Employing an anodization method into our fabrication process, we have successfully fabricated STJs with size of 4 μm in diameter, Josephson critical current density of 1000 A/cm², low leakage current of less than 10 pA at 0.3 K and high fabrication yield of more than 90 percent. These STJs were applied to fabricate submillimeter-wave direct detectors using 12 linearly distributed junctions, each circular junction having a current density of 600 A/cm² and size of 4 μm in diameter. Direct detection of submillimeter-waves was measured using a Fourier transform spectrometer, which shows a maximum sensitivity at 440 GHz and a fractional bandwidth of 10 percent.

Keywords

Fourier transform spectroscopy; anodisation; critical current density (superconductivity); focal planes; leakage currents; radioastronomical techniques; submillimetre wave detectors; superconducting junction devices; superconducting microwave devices; 0.3 K; 4 micron; 440 GHz; Fourier transform spectrometer; Josephson critical current density; STJs; anodization method; circular junction; current density; fabrication yield; focal plane array; fractional bandwidth; leakage current; linearly distributed junctions; submillimeter-wave direct detectors; superconducting tunnel junctions; Bandwidth; Critical current density; Current density; Detectors; Fabrication; Fourier transforms; Josephson junctions; Leakage current; Spectroscopy; Submillimeter wave measurements;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.814172

Filename

1211805