Accurate measurement of currents generated by single electrons transported in a one-dimensional channel

摘要

The acoustoelectric current generated by the transport of single electrons using surface acoustic waves through a one-dimensional channel offers the possibility of realising a quantun1 standard of current based on the electronic charge e. At NPL a measurement system using a commercial electrometer has been developed for investigating the flatness and accuracy of the constant current plateaux with an uncertainty of l5fA. Also a new instrument, based on a cryogenic current comparator (CCC), has bee11 developed with which it is expected that a relative accuracy of lfAA can be achieved. The authors present preliminary measurements of the quantised current using the electrometer and an experimental arrangement for resolving the 'n1etrological triangle' using the CCC.