Berlin 2014 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 16: Poster: Quantum information, micromechanical oscillators, matter wave optics, precision measurements and metrology
Q 16.76: Poster
Montag, 17. März 2014, 16:30–18:30, Spree-Palais
Sisyphus cooling of magnesium in an optical dipole trap — •Steffen Sauer, André Kulosa, Steffen Rühmann, Dominika Fim, Klaus Zipfel, Birte Lampmann, Leonie Theis, Wolfgang Ertmer, and Ernst Rasel — Institut für Quantenoptik, Leibniz Universität Hannover, Deutschland
We present a novel scheme of Sisyphus cooling of bosonic 24Mg. It consists of exploiting the differential AC-Stark shift which makes excited atoms interact with a steeper potential than those being in the ground state. This induces on average a net loss of kinetic energy by spontaneous decay. The theoretically achievable temperature limit given by this method is located at 1.9 µK which is the recoil temperature [1].
We cool 109 magnesium atoms in a first-stage magneto-optical trap (singlet-MOT) at 285 nm down to a final temperature of 3 mK. The 1S0 → 3P1 transition posseses a natural linewidth of 36 Hz only, prohibiting further cooling in a MOT. For this reason, the atoms are just pumped to the triplet manifold allowing for further cooling in a second-stage MOT (triplet MOT) at 383 nm to temperatures of 1 mK. Recently, we succeeded in beating the density limit of the triplet MOT by continuously loading an optical dipole trap at 1064 nm [2]. 105 atoms with a temperature of 100 µK in the 3P0 state are now optically pumped back to the 1S0 state where they are objected to the proposed innovation.
References:
[1] I. Ivanov and S. Gupta, Phys. Rev. A 84, 063417 (2011)
[2] M. Riedmann, et al., Phys. Rev. A 86, 043416 (2012)