Stuttgart 2012 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 3: Präzisionsmessungen und Metrologie 1
Q 3.4: Talk
Monday, March 12, 2012, 11:15–11:30, V47.02
Moving optical lattice for long range transport embedded in an optical clock — •Thomas Middelmann, Stephan Falke, Uwe Sterr, and Christian Lisdat — Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig
Optical clocks have surpassed cesium microwave clocks in stability and systematic uncertainty. A major concern for optical clocks is the frequency shift due to ambient thermal radiation. It is currently limiting the systematic uncertainty of Sr optical lattice clocks to 1 · 10−16 [1]. This blackbody shift can be described to high accuracy as a dc Stark shift from the rms electric field of the ambient blackbody radiation. Thus a dc Stark shift measurement allows a determination of the atomic response to a thermal radiation field. For this measurement ultracold Sr atoms need to be interrogated in the field of a precision capacitor [2]. Therefore a transport of ultracold atoms between the optical access region (MOT, detection) and the dc field (interrogation) is required in each clock cycle. Due to these spatial constrains and optical lattice requirements, we move the optical lattice by moving all its optics. We transport the atoms for 5 cm within 240 ms, with negligible heating, less than 4 % atom loss (back and forth), and maintain a clock stability of better than 3· 10−15 s−1/2.
The work is supported by the Centre for Quantum Engineering and Space-Time Research (QUEST) and the ERA-NET Plus Programme.
[1] Falke et al. Metrologia 48, 399 (2011).
[2] Middelmann et al. IEEE Trans. Instrum. Meas. 60, 2550 (2011).