Mainz 2017 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 46: Quantum Gases: Fermions I
Q 46.5: Vortrag
Donnerstag, 9. März 2017, 12:15–12:30, P 204
Pair formation in a fermionic system — •Thomas Paintner1, Daniel Hoffmann1, Wladimir Schoch1, Wolfgang Limmer1, Cheng Chin2, and Johannes Hecker Denschlag1 — 1Universität Ulm, Institut für Quantenmaterie, Deutschland — 2University of Chicago, James Franck Institute, USA
We investigate the pair formation in a fermionic system at the BEC-BCS crossover. For a given temperature and interaction strength a thermodynamic equilibrium forms between atoms and pairs.
We use a 50-50 mixture of the two lowest 6 Li Zeemann states and set their interaction strength by adjusting the scattering length with the help of the Feshbach resonance at 832 G. We then determine the fraction of paired atoms at different temperatures and interaction strengths using optical spectroscopy. The results are compared with a classical calculation [1]. Since the pair formation sets in for higher temperatures than the critical temperature Tc for superfluid transition our results provide a deeper insight into pairing and the pseudo-gap in fermionic systems.
[1] C. Chin et al., Physical Review A 69, 033612 (2004).