Chaotic behavior observed in a DC-biased josephson junction driven at fir frequencies

Conference · Fri Mar 01 04:00:00 EST 1985 · IEEE Trans. Magn.; (United States)

OSTI ID:6485577

Hu, Q; Free, J U; Iansiti, M; Liengme, O; Tinkham, M

We have investigated the response of a Nb-aSi-Nb junction to far-infrared laser radiation at 245, 419, and 604 GHz. At 419 GHz, which is close to the junction plasma frequency, the laser-induced steps in the I-V curves exhibit chaotic behavior over a considerable range of laser driving power. For example, regions of meandering voltage may appear on an otherwise well-defined and flat step. At such chaotic parts of the I-V curves, there is an extremely high level of low-frequency noise, corresponding to a noise temperature of about10/sup 11/K at frequencies around 100 Hz. Negative resistance regions are also observed. At some laser power levels, the I-V curve shows the 2/3 Josephson subharmonic step even in the absence of the 1st step. Smooth I-V curves reappear as the laser power is increased, showing the existence of chaos-free windows. The I-V curves taken at 245 GHz also show chaotic behavior, but those taken at 604 GHz are quite smooth. All these features are in good agreement with the results of digital simulations which confirm their chaotic nature.

• Research Organization: Physics Department and Division of Applied Sciences, Harvard University, Cambridge, MA
• OSTI ID: 6485577
• Report Number(s): CONF-840937-
• Conference Information: Journal Name: IEEE Trans. Magn.; (United States) Journal Volume: MAG-21:2
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
COMPUTERIZED SIMULATION
CURRENTS
DIRECT CURRENT
ELECTRIC CURRENTS
ELECTRODYNAMICS
ELECTROMAGNETIC RADIATION
FAR INFRARED RADIATION
FREQUENCY RANGE
GHZ RANGE
GHZ RANGE 100-1000
INFRARED RADIATION
JOSEPHSON JUNCTIONS
JUNCTIONS
LASER RADIATION
NIOBIUM ALLOYS
PERFORMANCE
RADIATIONS
SILICON ALLOYS
SIMULATION
SUPERCONDUCTING JUNCTIONS