title: Brownian motion of solitons in a Bose-Einstein condensate.
abstract: We observed and controlled the Brownian motion of solitons. We launched solitonic excitations in highly elongated [Formula: see text] Bose-Einstein condensates (BECs) and showed that a dilute background of impurity atoms in a different internal state dramatically affects the soliton. With no impurities and in one dimension (1D), these solitons would have an infinite lifetime, a consequence of integrability. In our experiment, the added impurities scatter off the much larger soliton, contributing to its Brownian motion and decreasing its lifetime. We describe the soliton's diffusive behavior using a quasi-1D scattering theory of impurity atoms interacting with a soliton, giving diffusion coefficients consistent with experiment.
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899.|Department of Physics, Cornell University, Ithaca, NY 14850.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Aycock
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899.|Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742.
authors.forename: Hilary M
authors.initials: HM
authors.lastname: Hurst
authors.affiliation: The Center for Complex Quantum Systems, The University of Texas at Austin, Austin, TX 78712-1192.
authors.forename: Dmitry K
authors.initials: DK
authors.lastname: Efimkin
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899.
authors.forename: Dina
authors.initials: D
authors.lastname: Genkina
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899.
authors.forename: Hsin-I
authors.initials: HI
authors.lastname: Lu
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899.|Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Galitski
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, MD, 20899; ian.spielman@nist.gov.
authors.forename: I B
authors.initials: IB
authors.lastname: Spielman
keywords: Bose–Einstein condensate; Brownian motion; diffusion; fluctuation dissipation; soliton