Ruprecht Karls Universität Heidelberg

New MOT / diploma thesis finished

The new MOT
The new MOT

We recently finished the construction of a new magneto-optical trap (MOT). With loading rates of 3·10^8 and higher, it will serve as a fast and efficient precooling stage for future experiments. The background collision limited lifetime of atoms in the trap is approximately 23 minutes.

More details on the apparatus can be found in Martin Ries' diploma thesis, which was handed in recently.
It is now available online: diplomarbeit_martin.pdf.



New Preprint Online

We have conducted a study of atom-dimer scattering in an ultracold three-component Fermi gas consisting of 6Li atoms in three different hyperfine states |1>,|2> and |3>.
For this we have prepared three different mixtures of atoms and dimers and observed their decay via inelastic atom-dimer collisions. In the |1>-|23> atom-dimer mixture we have observed resonant enhancement of the loss at the crossings of two Efimov-like trimer states with the |1>-|23> atom-dimer threshold. We have also found that these trimer states can cause a suppression of |3>-|12> → |1>-|23> exchange reactions in the |3>-|12> mixture, which allows to control the rate constants for these processes.
For more details on these results see arXiv:1003.0600


Two-body loss coefficient of the I1>-I23> mixture vs. magnetic field: the red line is a fit according to universal theory.
Two-body loss coefficient of the I1>-I23> mixture vs. magnetic field: the red line is a fit according to universal theory.
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First PhD thesis published

Congratulations Timo!
The thesis is available here:
Few-body physics in ultracold Fermi gases



Next diploma thesis finished

Recently Gerhard Zürn handed in his diploma thesis which is about the
"Realization of an Optical Microtrap for a Highly Degenerate Fermi Gas" .
It is now available online: thesis-gerhard.pdf.



now it’s micro: The microtrap is working!

In the last few weeks we accomplished another milestone on our way to a mesoscopic Fermi system the realization of a small volume optical dipole trap with high trapping frequencies ("microtrap"). More information will be provided in the diploma thesis of G. Zürn which will appear in a few weeks.

Shown is the optical density of the large volume dipole trap (a), the transfer between dipole trap and microtrap (b) and only the microtrap (c).
Shown is the optical density of the large volume dipole trap (a), the transfer between dipole trap and microtrap (b) and only the microtrap (c).


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