@inproceedings{44a6f790cfd345ffb91932c0f2c558fc,
title = "Frequency comparison of Al+ and Hg+ optical standards",
abstract = "We compare the frequencies of two single ion frequency standards: 27Al+ and 199Hg+. Systematic fractional frequency uncertainties of both standards are below 10-16, and the statistical measurement uncertainty is below 5 × 10 -17. Recent ratio measurements show a reproducibility that is better than 10-16.",
author = "T. Rosenband and Hume, \{D. B.\} and A. Brusch and L. Lorini and Schmidt, \{Piet Oliver\} and Fortier, \{T. M.\} and Stalnaker, \{J. E.\} and Diddams, \{S. A.\} and Newbury, \{N. R.\} and Swann, \{W. C.\} and Oskay, \{W. H.\} and Itano, \{W. M.\} and Wineland, \{D. J.\} and Bergquist, \{J. C.\}",
year = "2008",
month = jan,
day = "1",
language = "English",
isbn = "9812813195",
series = "Proceedings of the 18th International Conference on Laser Spectroscopy, ICOLS 2007",
publisher = "World Scientific Publishing Co. Pte Ltd",
pages = "297--302",
booktitle = "Proceedings of the 18th International Conference on Laser Spectroscopy, ICOLS 2007",
address = "Singapore",
note = "18th International Conference on Laser Spectroscopy, ICOLS 2007 ; Conference date: 24-06-2007 Through 29-06-2007",
}