Hume, David B.

Friday October 14,2011
Time: 15:00
Place: HPF G 6
Host: Jonathan Home

From quantum logic spectroscopy to coherent state detection: Experiments with AI⁺ clockwork

David B. Hume
University of Heidelberg, Germany

The ¹S₀ – ³P₀ transition in ²⁷Al⁺ has a natural linewidth of 8 mHz and exhibits low frequency shifts from electromagnetic fields, making it attractive as an optical frequency standard. The lack of an accessible transition in Al⁺ for direct laser cooling and fluorescence measurements requires that we use a simultaneously-trapped ion for sympathetic cooling and state detection. Two optical clocks have been built at NIST based on this principle. In this talk I will introduce the operation of the Al⁺ optical clocks and present data demonstrating their performance, with the newer clock exhibiting an inaccuracy below 10^-17. To extend these results and enable new experiments we have explored different techniques for Al⁺ state detection. One technique simultaneously detects the state of multiple Al⁺ allowing us to observe mutual coherence between two ions beyond Q = 10¹⁵. Another detection technique based on coherent states of motion simplifies spectroscopy of ²⁷Al⁺ and may be applied to a wide range of trapped-ion species.