Rapid sympathetic cooling to Fermi degeneracy on a chip
Abstract
Neutral fermions present new opportunities for testing models of many-body quantum systems, realizing precision atom interferometry, producing ultra-cold molecules, and investigating fundamental forces. However, since they were first observed, quantum degenerate Fermi gases (DFGs) have continued to be challenging to produce, and have been realized in only a handful of laboratories. In this letter, we report the production of a DFG using a simple apparatus based on a microfabricated magnetic trap. Similar approaches applied to Bose-Einstein condensation of 87Rb (refs 11,12) have accelerated evaporative cooling and eliminated the need for multiple vacuum chambers. We demonstrate sympathetic cooling for the first time in a microtrap, and cool 40K to Fermi degeneracy in just six seconds-faster than has been possible in conventional magnetic traps. To understand our sympathetic cooling trajectory, we measure the temperature dependence of the 40 K-87Rb cross-section and observe its Ramsauer-Townsend reduction.
- Publication:
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Nature Physics
- Pub Date:
- June 2006
- DOI:
- 10.1038/nphys309
- arXiv:
- arXiv:cond-mat/0512518
- Bibcode:
- 2006NatPh...2..384A
- Keywords:
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- Condensed Matter - Statistical Mechanics
- E-Print:
- 5 pages, 4 figures (v3: new collision data, improved atom number calibration, revised text, improved figures.)