In the `Electron Counting Capacitance Standard´ experiment a capacitor is charged by a well-known number of electrons, and the voltage developing is measured using a Josephson voltage standard. Eventually the `Electrical Quantum Triangle´ can be realized by tracing the capacitor's capacitance to the von-Klitzing constant, which tests the consistency of the three fundamental electrical quantum effects (quantum-Hall, Josephson and the single-electron tunnelling effect). The realization of the Electrical Quantum Triangle with an uncertainty of a few parts in 107 is considered an important milestone on the way to a new system of units, being entirely based on fundamental constants. PTB, as one of few metrology institutes world-wide, pursues the setup of this experiment for some time past (Fig. 1).
In the last year the operation of a five-junction single-electron tunneling (SET) pump, fabricated at PTB, was tested for the first time. Here, a...
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