The quantized Hall resistance: towards a primary standard of impedance

In this paper, it is shown that a quantum Hall resistor (QHR) which exhibits a proportionality relationship between the deviation of the Hall resistance from R-K/i and the ac dissipation in the system, represented by rho(xx), can be used as a primary standard of ac resistance. As an example, a calculable quadrifilar resistor was calibrated against the QHR at kilohertz frequencies. The agreement between the calibration using the QHR and the calculated frequency dependence of the quadrifilar resistor is better than 4 parts in 108 at 1 kHz. This result is achieved despite the frequency and current dependence of the ac-QHR. The most important criterion to achieve accurate measurements using an ac-QHR standard is to extrapolate the value of the Hall resistance to zero dissipation.