title: Observation of the first excited transverse mode in guided matter waves.
abstract: In direct analogy to the textbook example of light guided in a few-mode fiber (FMF), we report the observation of the first excited mode of an optically guided atomic beam. We selectively excite the atomic analog of the LP₀₁ optical mode by controlling the energy distribution of ultracold atoms loaded into the guide, resulting in a modal structure dominated by a 47(2)% population in the first excited transverse mode. The ability to guide lower-order modes has been essential to demonstrating optical effects such as multimode interferometry, slow light, and entanglement, and an atomic analog to a FMF may lead to similarly useful applications.
authors.affiliation: ARC Centre of Excellence for Quantum Atom Optics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200, Australia.
authors.forename: R G
authors.initials: RG
authors.lastname: Dall
authors.forename: S S
authors.initials: SS
authors.lastname: Hodgman
authors.forename: A G
authors.initials: AG
authors.lastname: Manning
authors.forename: A G
authors.initials: AG
authors.lastname: Truscott