Probing the Excitation Spectrum of a Fermi Gas in the BCS-BEC Crossover Regime

M. Greiner, C. A. Regal, D. S. Jin
2005 Physical Review Letters  
We measure excitation spectra of an ultracold gas of fermionic ^40K atoms in the BCS-BEC crossover regime. The measurements are performed with a novel spectroscopy that employs a small modulation of the B-field close to a Feshbach resonance to give rise to a modulation of the interaction strength. With this method we observe both a collective excitation as well as the dissociation of fermionic atom pairs in the strongly interacting regime. The excitation spectra reveal the binding energy /
more » ... nding energy / excitation gap for pairs in the crossover region.
doi:10.1103/physrevlett.94.070403 pmid:15783792 fatcat:gvukmz4zqfgefptcboe7tnxzcm