Heidelberg 2015 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 62: Poster: Quantum Optics and Photonics III

Q 62.30: Poster

Thursday, March 26, 2015, 17:00–19:00, C/Foyer

Trajectory-based micromotion compensation — Timm F. Gloger, Peter Kaufmann, •Delia Kaufmann, Thomas Collath, M. Tanveer Baig, Michael Johanning, and Christof Wunderlich — Universität Siegen, NT Fakultät, Department Physik, 57068 Siegen, Germany

For experiments with ions confined in a Paul trap, minimization of micromotion is often essential, e.g. in optical ion trapping, combined traps for neutral atoms and ions, or precision measurements. In order to diagnose and compensate micromotion we have implemented a method that allows for finding the position of the rf null reliably and efficiently, in principle, without any variation of dc voltages.

We apply a trap modulation technique and tomographic imaging to extract 3-d ion positions for various rf drive powers and analyze the power dependence of the equilibrium position of the trapped ion. Given sufficient knowledge about the trapping potential, the position of the rf null can be found efficiently without any variation of dc voltages by extrapolating the ion’s path to infinite rf power. In the case of significant uncertainies in the trapping potentials or substantial deviations of the potentials from being harmonic, parallel analysis of measurements for different compensation fields quickly yields not only a prediction of the rf null position but also the required compensation voltages. The method is also applied to measure the light pressure of a near resonant laser and it’s shift of the ion’s equilibrium position.