SQUID galvanometer for measurements of the quantized Hall resistance

• Published in: Japanese Journal of Applied Physics Vol. 26; no. 7; pp. 1159 - 1163
• Main Authors: MURAYAMA, Y, ENDO, T, KOYANAGI, M
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01-07-1987
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Superconducting devices; Electric transformer; Magnetometers; Josephson junction; Superconductor circuit; Potentiometer; Galvanometer; Superconductivity; Instrumentation; Quantum Hall effect; Background noise; Mutual inductance; Operation study; Sensitivity; Superconducting quantum interferometer device; Measurement method; High frequency
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/jjap.26.1159

A SQUID galvanometer composed of an rf SQUID magnetometer and a superconducting flux transformer has been developed in order to improve the measurement resolution of the quantized Hall resistance. The equivalent input noise current of the galvanometer obtained is 4.6×10
-13
A/√Hz. The measurement uncertainty of the quantized Hall resistance has been reduced to a few parts in 10
8
or less by the use of the galvanometer and a Josephson potentiometer. The resolution limit of the measurement is the thermal noise of resistors in the circuit.