Properties of a definition of the SI second based on several optical transitions
Atomic Physics
2025-03-18 v1
Abstract
The current definition of the SI second based on the Cs ground state hyperfine transition is expected to be replaced by a new definition based on optical frequency standards in the next decade. Several options are currently under consideration for the new definition, including a definition based on the weighted geometric mean of several transitions. In this paper, we review several properties of this option, and most notably introduce a quantitative method to set the weights of transitions, and a graphical representation of the unit that make the distinction between the definition and the realisation of the unit easier to understand.
Keywords
Cite
@article{arxiv.2503.13278,
title = {Properties of a definition of the SI second based on several optical transitions},
author = {Jérôme Lodewyck and Tetsuya Ido},
journal= {arXiv preprint arXiv:2503.13278},
year = {2025}
}