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Probing the excitation spectrum of a Fermi gas in the BCS-BEC crossover regime

Markus Greiner·Cindy A. Regal·Deborah S. Jin
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Abstract

We measure excitation spectra of an ultracold gas of fermionic $^{40}$K 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 / excitation gap for pairs in the crossover region.

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Markus Greiner, Cindy A. Regal, Deborah S. Jin. 2004-07-15. Probing the excitation spectrum of a Fermi gas in the BCS-BEC crossover regime. https://doi.org/10.1103/physrevlett.94.070403

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