Resonant control of elastic collisions in an optically trapped fermi gas of atoms.
We have loaded an ultracold gas of fermionic atoms into a far-off resonance optical dipole trap and precisely controlled the spin composition of the trapped gas. We have measured a magnetic-field Feshbach resonance between atoms in the two lowest energy spin states, /9/2,-9/2> and /9/2,-7/2>. The resonance peaks at a magnetic field of 201.5+/-1.4 G and has a width of 8.0+/-1.1 G. Using this resonance, we have changed the elastic collision cross section in the gas by nearly 3 orders of magnitude.
Loftus
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JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309, USA.
Regal
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CA
Ticknor
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Bohn
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JL
Jin
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