Focused electron beam damaged YBCO Josephson junctions for THz device applications

Author

Kim, S.-J. ; Yamashita, T.

Author_Institution

RIEC, Tohoku Univ., Sendai, Japan

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

4221

Lastpage

4224

Abstract

We investigate the high-frequency properties of focused electron beam (FEB) damaged Josephson junctions for THz device applications. The FEB damaged YBCO junctions exhibit the resistively shunted junction (RSJ)-like current-voltage (I-V) curve and the microwave-induced Shapiro steps for all operation temperatures. At 4.2 K, the junctions exhibited the microwave-induced Shapiro steps up to 3 mV in dV/dI-V curves suggesting that the junctions can respond up to about 1.5 THz. To estimate the high frequency performance of the junctions, direct irradiation by a far infrared (FIR) laser at 0.76 THz is carried out and the clear first Shapiro step is observed for the junctions with I/sub C/R/sub N/ product of about 2 mV and at the operation temperature of 6 K.

Keywords

Josephson effect; barium compounds; electron beam effects; high-temperature superconductors; superconducting microwave devices; yttrium compounds; 0.76 to 1.5 THz; 4.2 to 6 K; YBCO Josephson junction; YBaCuO; current-voltage characteristics; far infrared laser irradiation; focused electron beam damage; high frequency properties; microwave-induced Shapiro steps; resistively shunted junction; terahertz device; Electron beams; Finite impulse response filter; Frequency estimation; Grain boundaries; Josephson junctions; Nonhomogeneous media; Substrates; Superconducting microwave devices; Temperature; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783956

Filename

783956