High-frequency properties of microbridge and point contact Josephson junctions

Conference · Sun Jan 01 04:00:00 EST 1978 · AIP Conf. Proc.; (United States)

OSTI ID:5153128

Skocpol, W J

Recent experiments by the Harvard Superconductivity Group concerning the response of variable-thickness microbridges to high harmonics of microwave radiation and the response of selected Nb point contacts to far-infrared laser radiation are reviewed. Gap structure on the dc I-V characteristics of the various devices can be used to recognize those junctions with the best high-frequency performance. Microbridges which show large numbers of microwave-induced steps to voltages as high as 4.2 mV have been studied, although their poor coupling and low impedance has not yet allowed the observation of steps induced by submillimeter radiation. Selected Nb point contacts which have better coupling and higher resistance have been used to study the steps induced by harmonics of 604 GHz (496 ..mu..m) laser radiation to as high as 12.5 mV, and by higher fundamental frequencies up to 2.52 THz (119 ..mu..m) at 5.2 mV. Such contacts have been used to measure the intrinsic rolloff of the ac Josephson effect beyond the superconducting energy gap frequency.

• Research Organization: Harvard Univ., Cambridge, MA
• OSTI ID: 5153128
• Report Number(s): CONF-780339-
• Conference Information: Journal Name: AIP Conf. Proc.; (United States) Journal Volume: 44
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTROMAGNETIC RADIATION
ELECTRONIC CIRCUITS
FAR INFRARED RADIATION
FREQUENCY DEPENDENCE
INFRARED RADIATION
JOSEPHSON JUNCTIONS
MICROELECTRONIC CIRCUITS
MICROWAVE RADIATION
PERFORMANCE
RADIATIONS
RADIOWAVE RADIATION
SHORT WAVE RADIATION
SUPERCONDUCTING JUNCTIONS