Mainz 2017 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 40: Poster: Quantum Optics and Photonics II

Q 40.30: Poster

Wednesday, March 8, 2017, 17:00–19:00, P OG2

Investigation of fast ground state cooling schemes for a trapped Ca ion — Nils Scharnhorst¹, •Johannes Kramer¹, Javier Cerrillo Moreno², Alex Retzker³, Ian D. Leroux⁴, and Piet O. Schmidt^1,5 — ¹Physikalisch-Technische Bundesanstalt, 38116 Braunschweig — ²Technische Universität Berlin, 10623 Berlin — ³The Hebrew University of Jerusalem, 91904 Jerusalem — ⁴National Research Council Canada, 1200 Ottawa — ⁵Leibniz Universität Hannover, 30167 Hannover

One of the major systematic uncertainties of frequency standards based on light atoms, such as the aluminium ion, is the time dilation shift from residual motion. This requires fast near-ground state cooling of all motional modes to reduce this shifts and minimise dead time between interrogations. Conventional Doppler cooling techniques typically do not achieve the required reduction in motional energy. Sideband cooling techniques achieve this goal, but typically only for a single motional mode at a time. In multi-level atoms, coherences between levels can be used to design non-Lorentzian scattering spectra that selectively suppress heating processes, promising cooling times comparable to Doppler cooling. We investigate double-EIT cooling [1], based on a tripod level scheme in a calcium ion, involving the two ground states S_1/2 and the metastable D_5/2 levels. We demonstrate simultaneous cooling of the radial and axial motional modes of a ⁴⁰Ca⁺ ion near to the ground state in a single, short laser pulse.

[1] Evers, J. and Keitel, C. H., Europhys. Lett., 68 370 (2004).