title: Time-domain atom interferometry across the threshold for Bose-Einstein condensation.
abstract: We have performed time-domain interferometry experiments with matter waves trapped in a harmonic potential above and below the Bose-Einstein phase transition, by means of the method of separated oscillating fields, with a variable time delay T. We observe the oscillations of the population between two internal Zeeman states versus the delay T to be rapidly depleted both below and slightly above Bose-Einstein condensation. We give a quantitative explanation in terms of the phase evolution due to the entanglement between the internal and external degrees of freedom.
authors.affiliation: INFM-European Laboratory for Nonlinear Spectroscopy (LENS) and Dipartimento di Fisica, Università di Firenze, Largo E. Fermi 2, I-50125 Firenze, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Minardi
authors.forename: C
authors.initials: C
authors.lastname: Fort
authors.forename: P
authors.initials: P
authors.lastname: Maddaloni
authors.forename: M
authors.initials: M
authors.lastname: Modugno
authors.forename: M
authors.initials: M
authors.lastname: Inguscio