title: Precision measurements of collective oscillations in the BEC-BCS crossover.
abstract: We report on precision measurements of the frequency of the radial compression mode in a strongly interacting, optically trapped Fermi gas of (6)Li atoms. Our results allow for a test of theoretical predictions for the equation of state in the BEC-BCS crossover. We confirm recent quantum Monte Carlo results and rule out simple mean-field BCS theory. Our results show the long-sought beyond-mean-field effects in the strongly interacting Bose-Einstein condensation (BEC) regime.
authors.affiliation: Institute of Experimental Physics, Center for Quantum Physics, University of Innsbruck, 6020 Innsbruck, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Altmeyer
authors.forename: S
authors.initials: S
authors.lastname: Riedl
authors.forename: C
authors.initials: C
authors.lastname: Kohstall
authors.forename: M J
authors.initials: MJ
authors.lastname: Wright
authors.forename: R
authors.initials: R
authors.lastname: Geursen
authors.forename: M
authors.initials: M
authors.lastname: Bartenstein
authors.forename: C
authors.initials: C
authors.lastname: Chin
authors.forename: J Hecker
authors.initials: JH
authors.lastname: Denschlag
authors.forename: R
authors.initials: R
authors.lastname: Grimm