title: Bright Bose-Einstein gap solitons of atoms with repulsive interaction.
abstract: We report on the first experimental observation of bright matter wave solitons for 87Rb atoms with repulsive atom-atom interaction. This counterintuitive situation arises inside a weak periodic potential, where anomalous dispersion can be realized at the Brillouin zone boundary. If the coherent atomic wave packet is prepared at the corresponding band edge, a bright soliton is formed inside the gap. The strength of our system is the precise control of preparation and real time manipulation, allowing the systematic investigation of gap solitons.
authors.affiliation: Kirchhoff Institut für Physik, Universität Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Eiermann
authors.forename: Th
authors.initials: T
authors.lastname: Anker
authors.forename: M
authors.initials: M
authors.lastname: Albiez
authors.forename: M
authors.initials: M
authors.lastname: Taglieber
authors.forename: P
authors.initials: P
authors.lastname: Treutlein
authors.forename: K-P
authors.initials: KP
authors.lastname: Marzlin
authors.forename: M K
authors.initials: MK
authors.lastname: Oberthaler