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Alpha-dot or not: Comparison of two single atom optical clocks

  • T. Rosenband
  • , D.B. Hume
  • , C.W. Chou
  • , J. C J Koelemeij
  • , A. Brusch
  • , S. Bickman
  • , W. H. Oskay
  • , T. M. Fortier
  • , J. E. Stalnaker
  • , S. A. Diddams
  • , R. Newbury-Ecob
  • , W. C. Swann
  • , W. M. Itano
  • , D.J. Wineland
  • , J. C. Bergquist

Research output: Chapter in Book / Report / Conference proceedingConference contributionAcademicpeer-review

Abstract

Repeated measurements of the frequency ratio of 199Hg + and 27A1+ singleatom optical clocks over the course of a year yield a constraint on the possible present-era temporal variation of the fine-structure constant a. The time variation of the measured ratio corresponds to a time variation in the fine structure constant of ά/α = (-1.6 ± 2.3) × 10-17/year, consistent with no change. The frequency ratio of these clocks was measured with a fractional uncertainty of 5.2 × 10-17. Stability simulations for optical clocks whose probe period is limited by 1/f-noise in the laser local oscillator provide an estimate of the optimal probe period, as well as a modified expression for the theoretical clock stability.

Original languageEnglish
Title of host publicationProceedings of the 7th Symposium on Frequency Standards and Metrology, ISFSM 2008
Pages20-33
Number of pages14
Publication statusPublished - 2009
Event7th Symposium on Frequency Standards and Metrology, ISFSM 2008 - Pacific Grove, CA, United States
Duration: 5 Oct 200811 Oct 2008

Conference

Conference7th Symposium on Frequency Standards and Metrology, ISFSM 2008
Country/TerritoryUnited States
CityPacific Grove, CA
Period5/10/0811/10/08

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

  1. SDG 7 - Affordable and Clean Energy
    SDG 7 Affordable and Clean Energy

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