Events Calendar
Al+ optical clocks for fundamental physics and geodesy
Thursday May 3, 2012
| 3:30 pm
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Presenter: |
James Chin-wen Chou, National Institute of Standards and Technology, Boulder, CO.
Current address: Sandia National Laboratories, Albuquerque, NM. |
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| Series: | CQuIC Seminars | |
| Abstract: | Laser-cooled trapped atoms have long been recognized as potentially very accurate frequency standards for clocks. Ultimate accuracies of 10^-18 to 10^-19 appear possible, limited by the time-dilation of trapped ions that move at laser‐cooled velocities. The Al+ ion is an attractive candidate for high accuracy, owing to its narrow electronic transition in the optical regime and low sensitivity to ambient field perturbations. Precision spectroscopy on Al+ is enabled by quantum information techniques. With Al+ "quantum-logic" clocks, the current accuracy of 8.6 ×10^-18 has enabled a geo-potential-difference measurement that detected a height change of 37±17 cm due to the gravitational red‐shift. We have also observed quantum coherence between two Al+ ions with a record Q-factor of 3.4×10^16, and compared the Al+ resonance frequency to that of a single Hg+ ion to place limits on the temporal variation of the fine-structure constant. This work is done in collaboration with D. B. Hume, M. J. Thorpe, D. J. Wineland, and T. Rosenband. | |
| Location: | PAIS-2540, PAIS | |
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