A novel two-terminal-pair pulse-driven Josephson impedance bridge linking a 10 nF capacitance standard to the quantized Hall resistance

Abstract

In this paper the realization of a two-terminal-pair impedance bridge based on pulse-driven Josephson arrays will be presented. This bridge was used to link a 10 nF capacitance standard to the quantized Hall resistance at 1233 Hz. With pulse-driven Josephson arrays the setup for a quadrature bridge can be reduced dramatically. For the combination of the AC quantum Hall resistance and a 10 nF capacitance standard, most of the uncertainties caused by contact resistances in a two-terminal-pair definition were circumvented by a triple-series connection of the AC quantum Hall resistance. The capacitance value obtained by the new Josephson impedance bridge was compared to the results from a transformer-based ratio bridge and agrees within 1.3 parts in 108. Sources of systematic uncertainties were investigated and the combined relative uncertainty of the bridge was determined to be less than (k = 1) and 13.9 nF F−1 (k = 1) for the link of the 10 nF capacitance standard.