Practical Aspects of Counting Electrons with a Single-Electron Tunneling Pump

This review covers various aspects of the single-electron tunneling pumps based on Al junctions studied at NIST over the past 15 years. The operation of a pump is described, and some important error mechanisms are summarized, which allows for a sketch of the basic pump parameters required for metrological accuracy. Fabrication of pumps, filtering of leads in the cryostat, and the electronics used to drive the pump are described next. The shuttle error technique that allows measurement of very rare errors is then described, and some outstanding questions about limitations of pumps based on Al junctions are mentioned. A detailed algorithm for cancelling the cross capacitance in a pump is described in an appendix.