Method for determining the SQUID parameter b and the coupling coefficient K in a nonhysteretic rf SQUID

Journal Article · Wed Apr 01 04:00:00 EST 1981 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.329027· OSTI ID:6447194

Erne, S N; Luther, H

A method for determining the superconducting-quantum-interference-device (SQUID) parameter b = L/sub s/I/sub c//F/sub o/ and the coupling coefficient K between the SQUID loop and tank circuit based on the general theory for the nonhysteretic rf SQUID is derived. Analysis of the periodic dependence of the amplitude of the tank-circuit voltage on applied dc flux leads to explicit expressions for b and K. Important advantages of the method are that, during measurements, the SQUID loop has neither to be opened nor decoupled from the tank circuit, and the temperature of the sample does not have to be changed. Measurements with a Nb-point-contact SQUID at 4.2 K to verify the method in practice are reported. Intrinsic errors were estimated to be less than 10%.

• Research Organization: Physikalisch-Technische Bundesanstalt, Institut Berlin, Abbestrasse 2-12, D-1000 Berlin 10, West Germany
• OSTI ID: 6447194
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 52:4; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRONIC EQUIPMENT
ELEMENTS
EQUATIONS
EQUIPMENT
ERRORS
FLUXMETERS
HYSTERESIS
MAGNETIC FLUX
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
METALS
MICROWAVE EQUIPMENT
NIOBIUM
REFRACTORY METALS
RF SYSTEMS
SQUID DEVICES
SUPERCONDUCTING DEVICES
TRANSITION ELEMENTS
ULTRALOW TEMPERATURE
VARIATIONS