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This paper describes a Josephson-voltage-standard-locked synthesizer where a calibrator is used as a sine-wave generator, output whose is controlled by the calculable fundamental of the stepwise sinusoidal wave generated by a programmable Josephson junction array. Such a system combines the versatility of a calibrator with the stability and the accuracy of the Josephson voltage standard. The validity of this method was confirmed with the ac–dc difference measurements of a calibrated thermal-transfer standard. The synthesizer uncertainty inferred is below 1.2 \mu\V/V for waveform frequencies up to 1 kHz and root-mean-square amplitudes ranging from 100 mV to 1 V. [ABSTRACT FROM AUTHOR]

A test bench has been developed for systematic characterization of high-resolution analog-to-digital converters. The reference signal is generated by a programable Josephson voltage standard. Three 24-bit digitizers have been characterized. Noise performance has been measured at direct current using the Allan deviation, whereas integral nonlinearity has been measured with quasi-dynamic stepwise triangular waveforms at frequencies between 0.5 Hz and 1 kHz. None of the digitizers outperforms all others for each tested characteristics. Therefore, such a systematic characterization provides the overview needed to identify the most suitable digitizer for a given application. [ABSTRACT FROM AUTHOR]

An RLC bridge based on an automated synchronous sampling system has been developed using commercially available high-resolution analog-to-digital and digital-to-analog converters. This bridge allows the comparison of any kind of impedance standards in the four-terminal-pair configuration at frequencies between 50 Hz and 20 kHz within a range from 1 \Omega to 100 \k\Omega. An automatic balance of the bridge is carried out using a downhill simplex algorithm. Consistency checks have been realized by comparing resistance, inductance, and capacitance standards at different frequencies. The consistency of the measured voltage ratio is better than 20 \mu\V/V over the whole frequency range and even smaller than 5 \mu\V/V around 1 kHz. Finally, the results of the calibration of a 10-nF capacitance standard have been compared to those obtained using a commercial high-accuracy capacitance bridge. The difference is smaller than the commercial bridge specifications over the whole frequency range. [ABSTRACT FROM AUTHOR]

This paper addresses the effect of transients on the operation of a 1-V programmable Josephson voltage standard for frequencies ranging between 125 Hz and 4 kHz. A detrimental effect of the transients occurring during the transition between different voltage steps is to make the ac Josephson voltage dependent on the bias current in the junctions. In other words, the current margins where the array behaves as a quantum standard are reduced to zero: the voltage steps have a slope. However, by using square waveforms, the effect of the transients can be reduced to a level where this slope is no longer measurable. This observation will probably lead to a simplification in the development of a new type of high-precision Josephson-based waveform synthesizer. [ABSTRACT FROM AUTHOR]

This paper describes a Josephson-voltage-standard-locked synthesizer where a commercial digital-to-analog converter is used as a sine wave generator. The output amplitude of the generator is controlled by the calculable fundamental of the stepwise waveform generated by a SINIS Josephson junction array. Such a system combines the versatility of a commercial source with the stability and accuracy of the Josephson standard. By discarding the measurements performed during the transients, broad voltage steps of 1.7 mA were obtained up to frequencies of 500 Hz. [ABSTRACT FROM AUTHOR]

Recently, ac measurements of the quantized Hall resistance have shown a linear relationship between the deviation of the Hall resistance from the perfectly quantized value ARH and the dissipation in the system represented by the longitudinal resistivity ρxxac. In this paper, we present a phenomenological model based on electrodynamic arguments that model this relation. The dissipation is due to the displacement current flowing in the system. All the microscopic features are included in a complex tensorial dielectric susceptibility which remains to be investigated if more physical insight in the ac transport properties of the 2-D electron gas is desired. [ABSTRACT FROM AUTHOR]

A systematic investigation of the current and frequency dependence of the quantum Hall resistance (QHR) and of the longitudinal resistivity has been carried out at low temperature at the center of the plateau i = 2. The deviation of the QHR from the von Klitzing constant is found to be proportional to the longitudinal resistivity and extrapolates to zero, within the measurement uncertainty, when the dissipation in the two-dimensional electron gas vanishes. [ABSTRACT FROM AUTHOR]

The frequency dependence of ac resistors as well as the ac quantum Hall resistance shows sometimes unexpected linear terms of the order of 1.107 kHz1. Three reasons for measuring linear terms are identified as systematic effects of the coaxial bridge and the compared resistors. [ABSTRACT FROM AUTHOR]

In this paper, the operation of a seven-junction electron pump is presented. To characterize the pump, a single-electron tunneling transistor capacitively coupled to the pump was used. With this device, single electrons were manipulated one at a time. By performing electron pumping at a frequency of 1 MHz, an error rate of (4 ± 1) × 10-5 was determined. This preliminary result. is a solid milestone on the way to the capacitance standard presently under development at the Swiss Federal Office of Metrology and Accreditation. [ABSTRACT FROM AUTHOR]