Hannover 2010 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 21: Poster I

Q 21.36: Poster

Tuesday, March 9, 2010, 16:00–19:00, Lichthof

Towards an optical lattice clock with ⁸⁷Sr — •Stephan Falke, Christian Lisdat, Joseph Sundar Raaj Vellore Winfred, Thomas Middelmann, Fritz Riehle, and Uwe Sterr — Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany

Optical clocks can achieve a higher stability and lower systematic uncertainty than the best current microwave clocks. Both, ion clocks and optical lattice clocks are currently under investigation as candidates for a redefinition of the SI second. A very promising candidate for an optical lattice clock is strontium, in particular the fermionic isotope ⁸⁷Sr where the doubly forbidden ¹S₀ − ³P₀ transition is weakly allowed (natural linewidth 1.2 mHz) and collisional shifts are suppressed because two identical fermions cannot undergo s-wave scattering.

We trap ⁸⁷Sr atoms in a horizontal 1-D magic wavelength optical lattice, in which the atoms are confined in the Lamb-Dicke regime and hence motional effects are suppressed. Due to the hyperfine structure, the laser cooling and trapping of ⁸⁷Sr is more complicated compared to the most abundant isotope ⁸⁸Sr, which has been investigated in our laboratory previously. We will present how we cool, trap, prepare, and interrogate ⁸⁷Sr as well as considerations and measurements towards reducing the uncertainty budget of a ⁸⁷Sr optical lattice clock.

The work is supported by the Centre for Quantum Engineering and Space-Time Research (QUEST), ESA, DLR, and the ERA-NET Plus Programme.