Recent Results of the e/h-measurement at PTB
It has been shown by several experimentalists (1, ... ,4) that the steplike current-voltage characteristic based on the Josephson voltage-frequency relation can be used to determine the fundamental physical constant e/h with high accuracy. This frequency-voltage relation is as far as we know from various experiments, independent of influences such as temperature, type of junction, superconducting material, magnetic field,step number, microwavepower, and so on. So it seems that the Josephson effect provides the most reliable method of maintaining the volt.
KeywordsStandard Cell Josephson Effect Quartz Oscillator Step Amplitude Null Detector
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