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Q: Fachverband Quantenoptik und Photonik

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

Q 57.6: Poster

Donnerstag, 17. März 2011, 16:30–19:30, P1

Towards the realization of an erbium atomic quantum gas — •Henning Brammer, Jens Ulitzsch, Riad Bourouis, and Martin Weitz — Institut für Angewandte Physik, Universität Bonn

The erbium atom has a 4f¹² 6s^{2 3}H₆ electronic ground state with a large angular momentum of L = 5. So far realized atomic quantum gases all have been realized with a spericall symmetric (L=0) s-ground state configuration, for which in far detuned laser fields with detuning above the upper state fine structure splitting the trapping potential is determined by the scalar electronic polarizability. In contrast, for an erbium quantum gas with its L > 0 ground state, the trapping potential also for far detuned dissipation-less trapping laser fields becomes dependent on the internal atomic state (i.e. spin).

We have reported on progress in an ongoing experiment directed at the generation of an atomic erbium Bose-Einstein condensate by evaporative cooling in a far detuned optical dipole trap. In the present stage of the experiment, a magneto optical trap (MOT) for this rare earth metal atom has been realized, loaded from an effusive cell and decelerated by a Zeeman slower. The experiment uses a single laser frequency tuned to the red of the 400,91nm cooling transition. No repumping radiation is required for the MOT operation, despite the complex energy level structure of erbium and therefore the presence of several leak channels. This is attributed to the high magnetic moment of the erbium atom (7 µ_B), which allows a magnetic trapping of erbium atoms left in metastable energy levels in the MOT gradient magnetic field. Experimental data of the erbium MOT will be shown.