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Direct Resistance Comparisons From the QHR to 100 Megohm Using a Cryogenic Current Comparator



Randolph Elmquist, Emmanouel S. Hourdakis, Dean G. Jarrett, Neil M. Zimmerman


Measurements of 100 megohm standard resistors and cryogenic thin-film resistors based directly on a QHR standard have been made with a cryogenic current comparator (CCC) bridge. This 15496:2 ratio CCC attains a current sensitivity of 10.7 fA/Hz1/2 in measurements of cryogenic thin-film resistors without extensive shielding or filtering. A resistive primary winding helps the CCC maintain stability in the presence of external noise. The resistive-winding technique may be useful for the absolute measurement of small currents delivered by single-electron tunneling devices.
IEEE Transactions on Instrumentation and Measurement


Single-electron tunneling, Quantum Hall effect, Resistance standards, Johnson noise


Elmquist, R. , Hourdakis, E. , Jarrett, D. and Zimmerman, N. (2005), Direct Resistance Comparisons From the QHR to 100 Megohm Using a Cryogenic Current Comparator, IEEE Transactions on Instrumentation and Measurement, [online], (Accessed June 23, 2024)


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Created March 31, 2005, Updated October 12, 2021