Effect of radiofrequency pumping conditions on Josephson generation frequency in a resistive SQUID

Journal Article · Mon Feb 01 04:00:00 EST 1982 · Sov. Phys. - Tech. Phys. (Engl. Transl.); (United States)

OSTI ID:6591394

Vasil'ev, B V; Krivoi, G S

The dependence on the rf pumping power of the Josephson generation frequency f/sub J/ in a hysteresis SQUID with a single weak contact is detected and studied experimentally. The dependence shows up in the first plateau of the current-voltage characteristic of the oscillatory circuit associated with the resistive SQUID. When a dc current I/sub 0/ was transmitted through the SQUID in the experiments, the frequency f/sub J/ was found to be less at the edges of the plateau than in the middle, with the difference increasing at smaller currents I/sub 0/. The length of the nonlinear initial part of the characteristic f/sub J/(I/sub 0/) is greater at the edges of the plateau than at the center. The shape of the envelope of the amplitude-modulated voltage in the circuit associated with the resistive SQUID also depends on the rf pumping power and is not a symmetric triangle at the edges of the plateau. These features of the SQUID are attributed to the dependence of the low-frequency component of the current amplitude (average current) in a resistive SQUID on the rf pump power, and do not indicate a violation of the fundamental Josephson relation for the generation frequency when there is weak coupling. The above dependence of f/sub J/ on I/sub 0/ must be allowed for in measuring infralow voltages, particularly in noise thermometry for temperatures in the 10/sup -3/ K range.

• OSTI ID: 6591394
• Journal Information: Sov. Phys. - Tech. Phys. (Engl. Transl.); (United States), Journal Name: Sov. Phys. - Tech. Phys. (Engl. Transl.); (United States) Vol. 27:2; ISSN SPTPA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CRITICAL FREQUENCY
ELECTRIC POTENTIAL
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUXMETERS
FREQUENCY CONVERTERS
HYSTERESIS
JOSEPHSON EFFECT
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
PUMPING
RF SYSTEMS
SIGNAL DISTORTION
SQUID DEVICES
SUPERCONDUCTING DEVICES