Invited Paper IPF-TuA8
Optical Atomic Clocks

Tuesday, October 21, 2008, 4:00 pm, Room 312

Quantum state engineering of ultracold matter and precise control of optical fields have allowed accurate measurement of light-matter interactions for the development of best atomic clocks. State-of-the-art lasers now maintain optical phase coherence over one second. Optical frequency combs distribute this optical phase coherence across the entire visible and infrared parts of the electromagnetic spectrum, leading to direct visualization and measurement of light ripples. An the same time, ultracold atoms confined in an optical lattice of zero differential a.c. Stark shift between two clock states allow us to minimize quantum decoherence while strengthen the clock signal. For ⁸⁷Sr, we achieve a resonance quality factor >2 x 10¹⁴ on the ¹S₀ – ³P₀ doubly forbidden clock transition at 698 nm.¹ The uncertainty of this new clock has reached 1 x 10^-16 and its instability approaches 1 x 10^-15 at 1 s.² These developments represent a remarkable convergence of ultracold atoms, laser stabilization, and ultrafast science. Further improvements are still tantalizing, with quantum measurement and precision metrology combining forces to explore the next frontier.

¹ M. M. Boyd, T. Zelevinsky, A. D. Ludlow, S. M. Foreman, S. Blatt, T. Ido, and J. Ye, “Optical atomic coherence at the one second time scale,” Science Vol. 314, pp. 1430 – 1433, 2006.
²A. D. Ludlow, T. Zelevinsky, G. K. Campbell, S. Blatt, M. M. Boyd, M. H. de Miranda, M. J. Martin, J. W. Thomsen, S. M. Foreman, J. Ye, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, Y. Le Coq, Z. W. Barber, N. Poli, N. D. Lemke, K. M. Beck, and C. W. Oates, “Evaluation of a Sr lattice clock at 1x10-16 via remote optical comparison with a Ca clock,” Science Vol. 319, pp. 1805 – 1808, 2008.