|
|
ReportsFrequency Ratio of Al+ and Hg+ Single-Ion Optical Clocks; Metrology at the 17th Decimal Place  
Time has always had a special status in physics because of its fundamental role in specifying the regularities of nature and because of the extraordinary precision with which it can be measured. This precision enables tests of fundamental physics and cosmology, as well as practical applications such as satellite navigation. Recently, a regime of operation for atomic clocks based on optical transitions has become possible, promising even higher performance. We report the frequency ratio of two optical atomic clocks with a fractional uncertainty of 5.2 x 10–17. The ratio of aluminum and mercury single-ion optical clock frequencies National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA.
|| Present address: Department of Physics and Astronomy, Oberlin College, Oberlin, OH 44074, USA. * To whom correspondence should be addressed. E-mail: trosen{at}boulder.nist.gov
The editors suggest the following Related Resources on Science sites:In Science Magazine
|
Al+/
of 
. 
Present address: Institut für Experimentalphysik, Universität Innsbruck, Austria. 
Present address: Istituto Nazionale di Ricerca Metrologica (INRIM), Torino, Italy. 
Present address: Stanford Research Systems, Sunnyvale, CA 94089, USA. 
Magazine | News | Signaling | Careers | Multimedia | Collections | Help | Site Map | RSS
Subscribe | Feedback | Privacy / Legal | About Us | Advertise With Us | Contact Us
© 2008 American Association for the Advancement of Science. All Rights Reserved.
AAAS is a partner of HINARI, AGORA, PatientInform, CrossRef, and COUNTER.
You have reached the bottom of the page. Back to top