Progress Towards the Electron Counting Capacitance Standard at PTB

We report on the progress and new results in the setup of the electron counting capacitance standard (ECCS) at Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany. Considerable progress has been made in the operation of the single-electron circuit and in the incorporation of a cryogenic capacitor into the millikelvin refrigerator setup. The single-electron tunneling (SET) circuit comprised a five-junction, single-electron
R
-pump that showed an electron retention time of more than 600 s, and the circuit was successfully used for the deterministic shuttle transfer of charge packets consisting of few electrons. In addition, the cryogenic capacitor was tested, and its performance was found to be suitable for a high-precision ECCS experiment.