Title :
Terahertz response for bicrystal YBCO Josephson junctions
Author :
Nakajima, K. ; Jian Chen ; Myoren, H. ; Yamashita, T. ; Peiheng Wu
Author_Institution :
Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan
fDate :
6/1/1997 12:00:00 AM
Abstract :
The high-frequency response of bicrystal YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// Josephson junctions for far infrared laser irradiation is presented. The junctions on silicon and MgO substrates exhibit a remarkable first order Shapiro step for the methanol line at 1.76 THz. dV/dI measurements reveal several steps corresponding to the methanol lines at 1.48, 1.76 and 2.53 THz. The line width of Josephson oscillation at these frequencies is estimated from the width of the Shapiro steps. It is suggested that the excess shot noise broadens the line width.
Keywords :
Josephson effect; barium compounds; grain boundaries; high-temperature superconductors; laser beam effects; oscillations; shot noise; submillimetre wave detectors; superconducting device noise; superconducting junction devices; superconducting particle detectors; yttrium compounds; 1.48 to 2.52 THz; FIR laser irradiation; Josephson oscillation; MgO; MgO substrate; Shapiro steps; Si; Si substrate; YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//; YBa/sub 2/Cu/sub 3/O/sub 7/-MgO; YBa/sub 2/Cu/sub 3/O/sub 7/-Si; bicrystal YBCO Josephson junctions; excess shot noise; far infrared laser irradiation; high-frequency response; line width; methanol lines; terahertz response; Finite impulse response filter; Frequency estimation; Grain boundaries; Josephson junctions; Methanol; Pump lasers; Semiconductor films; Silicon; Voltage; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
