title: Sub-poissonian number differences in four-wave mixing of matter waves.
abstract: We demonstrate sub-Poissonian number differences in four-wave mixing of Bose-Einstein condensates of metastable helium. The collision between two Bose-Einstein condensates produces a scattering halo populated by pairs of atoms of opposing velocities, which we divide into several symmetric zones. We show that the atom number difference for opposing zones has sub-Poissonian noise fluctuations, whereas that of nonopposing zones is well described by shot noise. The atom pairs produced in a dual number state are well adapted to sub-shot-noise interferometry and studies of Einstein-Podolsky-Rosen-type nonlocality tests.
authors.affiliation: Laboratoire Charles Fabry de l'Institut d'Optique, CNRS, Univ Paris-Sud, Campus Polytechnique RD128 91127 Palaiseau, France.
authors.forename: J-C
authors.initials: JC
authors.lastname: Jaskula
authors.forename: M
authors.initials: M
authors.lastname: Bonneau
authors.forename: G B
authors.initials: GB
authors.lastname: Partridge
authors.forename: V
authors.initials: V
authors.lastname: Krachmalnicoff
authors.forename: P
authors.initials: P
authors.lastname: Deuar
authors.forename: K V
authors.initials: KV
authors.lastname: Kheruntsyan
authors.forename: A
authors.initials: A
authors.lastname: Aspect
authors.forename: D
authors.initials: D
authors.lastname: Boiron
authors.forename: C I
authors.initials: CI
authors.lastname: Westbrook