Skip to main content

NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Frequency Comparison of Two High-Accuracy Al+ Optical Clocks

Published

Author(s)

Chin-Wen Chou, David Hume, J.C. Koelemeij, David J. Wineland, Till P. Rosenband

Abstract

We have constructed an optical clock with a fractional frequency inaccuracy of 8.6e-18, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser-cool the Al+ ion and detect its quantum state. The frequency of the 1S0->3P0 clock transition is compared to that of a previously constructed Al+ optical clock with a statistical measurement uncertainty of 7.0e-18. The two clocks exhibit a relative stability of 2.8e-15/ sqrt(tau), and a fractional frequency difference of -1.8e-17, consistent with the accuracy limit of the older clock.
Citation
Physical Review Letters
Volume
104

Keywords

atomic clock, optical clock, high accuracy, aluminum ion, quantum logic

Citation

Chou, C. , Hume, D. , Koelemeij, J. , Wineland, D. and Rosenband, T. (2010), Frequency Comparison of Two High-Accuracy Al+ Optical Clocks, Physical Review Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904590 (Accessed October 9, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created February 17, 2010, Updated February 19, 2017
Was this page helpful?