title: Enhanced and reduced atom number fluctuations in a BEC splitter.
abstract: We measure atom number statistics after splitting a gas of ultracold 87Rb atoms in a purely magnetic double-well potential created on an atom chip. Well below the critical temperature for Bose-Einstein condensation Tc, we observe reduced fluctuations down to -4.9 dB below the atom shot noise level. Fluctuations rise to more than +3.8 dB close to Tc, before reaching the shot noise level for higher temperatures. We use two-mode and classical field simulations to model these results. This allows us to confirm that the supershot noise fluctuations directly originate from quantum statistics.
authors.affiliation: Laboratoire Kastler-Brossel, ENS, Université Pierre et Marie Curie-Paris 6, CNRS, 24 rue Lhomond, 75 231 Paris Cedex 05, France.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Maussang
authors.forename: G Edward
authors.initials: GE
authors.lastname: Marti
authors.forename: Tobias
authors.initials: T
authors.lastname: Schneider
authors.forename: Philipp
authors.initials: P
authors.lastname: Treutlein
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.forename: Alice
authors.initials: A
authors.lastname: Sinatra
authors.forename: Romain
authors.initials: R
authors.lastname: Long
authors.forename: Jérôme
authors.initials: J
authors.lastname: Estève
authors.forename: Jakob
authors.initials: J
authors.lastname: Reichel