Session A1: Plenary Prize Session

8:00 AM–9:48 AM, Wednesday, June 6, 2007
TELUS Convention Centre Room: Macleod BCD

Chair: T. Gay, University of Nebraska-Lincoln

Abstract ID: BAPS.2007.DAMOP.A1.2

Abstract: A1.00002 : Broida Prize Talk: Stable and Accurate Single-Atom Optical Clocks

8:36 AM–9:12 AM

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Author:

James Bergquist
(APS)

The potential for high stability and accuracy of optical clocks based on narrow transitions of single ions has begun to be realized [1-3]. At NIST, we have constructed and are operating two single-ion optical clocks; one based on the $^{2}$S$_{1/2}$ ($F$ = 0) $\leftrightarrow \quad ^{2}$D$_{5/2}$ ($F$ = 2, $m_{F} = 0)$ electric-quadrupole transition ($\lambda$ = 282 nm, $\nu$ = 1.064 PHz) of a single, laser-cooled $^{199}$Hg$^{+}$ ion held in a cryogenic rf Paul trap, and one based on the $^{1}$S$_{0} \quad \leftrightarrow \quad ^{3}$P$_{0}$ intercombination line ($\lambda$ = 267 nm, $\nu$ = 1.124 PHz) of a single $^{27}$Al$^{+}$ ion held in a linear trap [4]. The burden of cooling, state preparation and state detection of the Al$^{+}$ ion are borne by an auxiliary Be$^{+}$ ion using quantum logic methods [5]. In a recent comparison of these two standards, we have achieved a relative fractional frequency instability of less than 7 $\times$ 10$^{-15 }(\tau$/s)$^{-1/2}$, reaching 4 $\times$ 10$^{-17}$ in 30 000 s. We have also compared the frequency of the Hg$^{+}$ optical clock to that of the cesium fountain standard NIST-F1, for which we obtained fractional frequency inaccuracies below 10$^{-15}$. Repeated measurements of the frequency ratios of the clock transitions of all three standards provide intriguing possibilities for laboratory tests of fundamental physics, such as testing for the constancy'' of the fundamental constants. We will report the results of measurements conducted over the course of five years and discuss the implications of these results as a constraint to present-day temporal variation of the constants [6]. \newline \newline \textbf{References} \newline [1] H.S. Margolis \textit{et al., }Science \textbf{306}, 1355 (2004). \newline [2] T. Schneider, E. Peik, and Chr. Tamm, Phys. Rev. Lett. \textbf{94}, 230801 (2005). \newline [3] W.H. Oskay \textit{et al.}, Phys. Rev. Lett. \textbf{97}, 020801 (2006). \newline [4] P.O. Schmidt \textit{et al., }Science \textbf{309}, 749 (2005). \newline [5] D.J. Wineland \textit{et al.}, \textit{Proc. 6th Symposium on Frequency Standards and Metrology, }P. Gill, ed. (World Scientific, Singapore, 2002) pp. 361-368. \newline [6] T. M. Fortier \textit{et al.,} Phys. Rev. Lett. accepted for publication (2007).

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.DAMOP.A1.2