Dresden 2011 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 57: Poster 3: Quantengase, Ultrakalte Atome, Ultrakalte Moleküle, Materiewellen Optik, Präzisionsmessungen, Metrologie

Q 57.92: Poster

Thursday, March 17, 2011, 16:30–19:30, P1

Strontium in an Optical Lattice as a Mobile Frequency Reference — •Ole Kock, Steven Johnson, Yeshpal Singh, and Kai Bongs — School of Physics and Astronomy, University of Birmingham, United Kingdom

The higher frequencies ( 10¹⁵ Hz) of the atomic transitions enable a greater accuracy than the current microwave frequency ( 10¹⁰ Hz) standard. Optical clocks have now achieved a performance significantly beyond that of the best microwave clocks, at a fractional frequency uncertainty of 8.6 * 10⁻¹⁸ [Chou]. With the rapidly improving performance of optical clocks, in the future, most applications requiring the highest accuracy will require optical clocks. We are setting up an experiment aimed at a mobile frequency standard based on strontium (Sr) in a blue detuned optical lattice. Sr is an alkaline-earth element and has two electrons in its outer shell, which give rise to a singlet state (ground state) and a triplet state. The dipole transitions from a singlet state to a triplet state are forbidden, which results in a long meta-stable lifetimes and as narrow line widths as one mHz. The unprecedented accuracy in time promises new applications like relativistic geodesy for exploration of oil and minerals, fundamental tests of general relativity and synchronization for long base line astronomical interferometry. It is worth mentioning that very recently, space has also opened up as a new venue for precision measurements based on cold atoms. An up to date progress on a compact and robust frequency standard experiment will be presented. 1) C.W. Chou, D. B. Hume, J. C. J. Koelemeij, D. J. Wineland, and T. Rosenband, PRL 104, 070802 (2010).