We measure the average number of electrons loaded into an electrostatically-defined quantum dot (QD) operated as a tunable-barrier electron pump, using a point-contact (PC) charge sensor 1 micron away from the QD. The measurement of the electron number probes the QD loading dynamics even in the limit of slow gate voltage rise-times, when the pumped current is too small to measure. Using simulations we show that, with optimised QD-PC coupling, the experiment can make single-shot measurements of the number of electrons in the QD with sufficiently high fidelity to test the error rate of the electron pump with metrological precision.
@article{arxiv.1809.10249,
title = {Error detection in a tunable-barrier electron pump},
author = {S. P. Giblin and P. See and J. D. Fletcher and T. J. B. M. Janssen and J. P. Griffiths and G. A. C. Jones and I. Farrer and M. Kataoka},
journal= {arXiv preprint arXiv:1809.10249},
year = {2018}
}
Comments
6 pages, 4 figures. This is an unpublished study preceding the work published as "High-resolution error detection in the capture process of a single-electron pump", Applied Physics Letters vol. 108, 023502 (2016)