title: Local observation of pair condensation in a Fermi gas at unitarity.
abstract: We present measurements of the local (homogeneous) density-density response function of a Fermi gas at unitarity using spatially resolved Bragg spectroscopy. By analyzing the Bragg response across one axis of the cloud, we extract the response function for a uniform gas which shows a clear signature of the Bose-Einstein condensation of pairs of fermions when the local temperature drops below the superfluid transition temperature. The method we use for local measurement generalizes a scheme for obtaining the local pressure in a harmonically trapped cloud from the line density and can be adapted to provide any homogeneous parameter satisfying the local density approximation.
authors.affiliation: Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne, Victoria 3122, Australia.
authors.forename: M G
authors.initials: MG
authors.lastname: Lingham
authors.affiliation: Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne, Victoria 3122, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Fenech
authors.affiliation: Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne, Victoria 3122, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Hoinka
authors.affiliation: Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne, Victoria 3122, Australia.
authors.forename: C J
authors.initials: CJ
authors.lastname: Vale