title: Molecular probe of pairing in the BEC-BCS crossover.
abstract: We have used optical molecular spectroscopy to probe the many-body state of paired 6Li atoms near a broad Feshbach resonance. The optical probe projects pairs of atoms onto a vibrational level of an excited molecule. The rate of excitation enables a precise measurement of the closed-channel contribution to the paired state. This contribution is found to be quite small, supporting the concept of universality for the description of broad Feshbach resonances. The dynamics of the excitation provide clear evidence for pairing across the BEC-BCS crossover and into the weakly interacting BCS regime.
authors.affiliation: Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, Texas 77251, USA.
authors.forename: G B
authors.initials: GB
authors.lastname: Partridge
authors.forename: K E
authors.initials: KE
authors.lastname: Strecker
authors.forename: R I
authors.initials: RI
authors.lastname: Kamar
authors.forename: M W
authors.initials: MW
authors.lastname: Jack
authors.forename: R G
authors.initials: RG
authors.lastname: Hulet