title: Weakly interacting Bose gas in the one-dimensional limit.
abstract: We prepare a chemically and thermally one-dimensional (1D) quantum degenerate Bose gas in a single microtrap. We introduce a new interferometric method to distinguish the quasicondensate fraction of the gas from the thermal cloud at finite temperature. We reach temperatures down to kT≈0.5ℏω(⊥) (transverse oscillator eigenfrequency ω(⊥)) when collisional thermalization slows down as expected in 1D. At the lowest temperatures the transverse-momentum distribution exhibits a residual dependence on the line density n(1D), characteristic for 1D systems. For very low densities the approach to the transverse single-particle ground state is linear in n(1D).
authors.affiliation: Midlands Ultracold Atom Research Centre (MUARC), School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Krüger
authors.forename: S
authors.initials: S
authors.lastname: Hofferberth
authors.forename: I E
authors.initials: IE
authors.lastname: Mazets
authors.forename: I
authors.initials: I
authors.lastname: Lesanovsky
authors.forename: J
authors.initials: J
authors.lastname: Schmiedmayer