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
The thesis is available here:
Few-body physics in ultracold Fermi gases
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.
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.
Andre Wenz just handed in his diploma thesis with the title
"Few-Body Physics in a Three-Component Fermi Gas".
It is now available online at: thesis-andre.pdf.
Our work on three-component Fermi gases has been published in Physical Review Letters.
It is now available online at PRL 101, 203202.
The next diploma thesis done in our group was just handed in by Matthias Kohnen.
The title is: "Ultracold Fermi Mixtures in an Optical Dipole Trap"
and it is now available online at:
Recently we managed to prepare a three-component degenerate Fermi gas of 6Li with 50000 atoms in each state at a temperature of 215 nK, which corresponds to T/TF=0.37.
We studied the collisional stability of the gas in the magnetic field range from 0 to 750 G and found a broad and pronounced loss feature at 130 G. At approximately 580 G the sample remains quite stable, with 1/e lifetimes exceeding 30 s.
For a more quantitative analysis we deduced the three-body loss coefficient K3 from lifetime measurements.
The new results are available at arXiv:0806.0587.