title: Condensation of pairs of fermionic atoms near a Feshbach resonance.
abstract: We have observed Bose-Einstein condensation of pairs of fermionic atoms in an ultracold 6Li gas at magnetic fields above a Feshbach resonance, where no stable 6Li2 molecules would exist in vacuum. We accurately determined the position of the resonance to be 822+/-3 G. Molecular Bose-Einstein condensates were detected after a fast magnetic field ramp, which transferred pairs of atoms at close distances into bound molecules. Condensate fractions as high as 80% were obtained. The large condensate fractions are interpreted in terms of preexisting molecules which are quasistable even above the two-body Feshbach resonance due to the presence of the degenerate Fermi gas.
authors.affiliation: Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Zwierlein
authors.forename: C A
authors.initials: CA
authors.lastname: Stan
authors.forename: C H
authors.initials: CH
authors.lastname: Schunck
authors.forename: S M F
authors.initials: SM
authors.lastname: Raupach
authors.forename: A J
authors.initials: AJ
authors.lastname: Kerman
authors.forename: W
authors.initials: W
authors.lastname: Ketterle