### Session J2: Fundamental Symmetry Tests

10:30 AM–12:30 PM, Wednesday, June 15, 2011
Room: A602

Chair: David DeMille, Yale University

Abstract ID: BAPS.2011.DAMOP.J2.4

### Abstract: J2.00004 : Al$^{+}$ optical clocks for fundamental physics, geodesy, and quantum metrology

12:00 PM–12:30 PM

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#### Author:

Chin-wen Chou
(National Institute of Standards and Technology)

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$\times$10$^{-18}$ has enabled a geo-potential-difference measurement that detected a height change of 37$\pm$17 cm due to the gravitational red-shift. We have also observed quantum coherence between two Al$^{+}$ ions with a record Q-factor of 3.4$\times$10$^{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.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.DAMOP.J2.4