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A: Fachverband Atomphysik
A 17: Ultra-Cold Atoms, Ions and BEC III (with Q)
A 17.7: Vortrag
Donnerstag, 11. März 2010, 12:00–12:15, F 303
Preparation of a degenerate mesoscopic sample of fermions — •Friedhelm Serwane1,2, Timo Ottenstein1,2, Thomas Lompe1,2, Gerhardt Zürn1,2, Martin Ries1,2, Philipp Simon1,2, and Selim Jochim1,2 — 1Max-Planck-Institut für Kernphysik, Heidelberg — 2Physikalisches Institut, Universität Heidelberg
Systems consisting of only few degenerate interacting fermions have prominent examples in nature: e.g. nuclei in the atomic core. Our goal is the preparation of such a system with tunable properties in the laboratory using ultracold fermionic 6Li atoms. Here, the interaction strength can be tuned over many orders of magnitude by means of a Feshbach resonance.
With the ability to control the number of fermions in the trap, studies of the system’s properties in dependence of the atom number n will become possible. One intriguing example is the appearance of many-body effects such as superfluidity. In the extreme limit, the sample consists of only two atoms in different spin states which potentially can be used as a high-fidelity qubit.
To control n precisely, we transfer atoms from a large optical dipole trap into a micron-sized dipole trap with well separated energy levels. By applying a magnetic field gradient, we are able to spill atoms in a controlled way ending up with a highly degenerate Fermi gas. So far we can control the atom number down to 120 atoms, limited by the imaging technique. Also we were able to count single atoms in a MOT with fluorescence imaging. In the next step we will combine these techniques to study smaller samples of highly degenerate fermions.