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PRODID:-//University of Illinois//Web Services Calendar//EN
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTSTAMP:20120214T144221Z
DTSTART;TZID=America/Chicago:20091111T120000
DTEND;TZID=America/Chicago:20091111T120000
SUMMARY:QI/AMO Seminar:  "Comparison of Aluminum Ion Optical Clocks at th
 e 17th Decimal Place"
CREATED:20091005T130000Z
DESCRIPTION:Atomic clocks based on optical transitions\, or optical clock
 s\, have been suggested as candidates for the next-generation time and f
 requency standards. Owing to their high operating frequencies\, optical 
 clocks promise orders of magnitude improvement in the stability and accu
 racy over the current standard\, cesium fountain clocks. Optical clocks 
 can be categorized by the reference atom\, whether it be an individual a
 tom/ion or ensemble of neutral atoms. Currently\, the most accurate opti
 cal clocks are based on single trapped ions\, partially due to the exqui
 site control of the fields affecting their electronic and motional quant
 um states. In a recent measurement of the frequency ratio between single
 -ion optical clocks based on 27Al+ and 199Hg+ at NIST\, the combined sta
 tistical and systematic uncertainties have reached 5.2  10-17[1].  To fu
 rther improve the accuracy and stability of the 27Al+ optical clock\, we
  have developed a new trap as well as the lasers that enable the use of 
 25Mg+ for efficient sympathetic cooling of 27Al+ and clock-state detecti
 on. These developments have reduced the systematic uncertainty below 10-
 17. In the new clock apparatus we have demonstrated spectroscopy of the 
 27Al+ 1S0 to 3P0 transition with a quality factor of Q = 4.2  1014 and s
 ignal contrast approaching unity. The latest comparison between the two 
 27Al+ optical clocks shows that the two clocks agree to within the stati
 stical uncertainty of 2.5  10-17 when the known systematic shifts are su
 btracted. One of the largest relative shifts between the two clocks is t
 he gravitational red shift due to the difference in height of about 17 c
 m.[1] T. Rosenband et al.\, Science 319\, 1808 (2008)
LAST-MODIFIED:20091023T130000Z
LOCATION:280 Materials Research Lab.\, 104 S. Goodwin Ave.\, Urbana
CATEGORIES:QI/AMO Seminar
CONTACT:Linda Thorman 217-333-1590
ORGANIZER:thorman@illinois.edu
URL:http://illinois.edu/calendar/detail/1968?key=2000010120000101143906
UID:143906@illinois.edu
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