title: Towards a quantum representation of the ampere using single electron pumps.
abstract: Electron pumps generate a macroscopic electric current by controlled manipulation of single electrons. Despite intensive research towards a quantum current standard over the last 25 years, making a fast and accurate quantized electron pump has proved extremely difficult. Here we demonstrate that the accuracy of a semiconductor quantum dot pump can be dramatically improved by using specially designed gate drive waveforms. Our pump can generate a current of up to 150 pA, corresponding to almost a billion electrons per second, with an experimentally demonstrated current accuracy better than 1.2 parts per million (p.p.m.) and strong evidence, based on fitting data to a model, that the true accuracy is approaching 0.01 p.p.m. This type of pump is a promising candidate for further development as a realization of the SI base unit ampere, following a redefinition of the ampere in terms of a fixed value of the elementary charge.
authors: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK. stephen.giblin@npl.co.uk
authors: S P
authors: SP
authors: Giblin
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authors: Kataoka
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authors: JD
authors: Fletcher
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authors: See
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authors: Janssen
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authors: Griffiths
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authors: Jones
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authors: Farrer
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authors: Ritchie