title: Matter-wave gap vortices in optical lattices.
abstract: We predict the existence of spatially localized nontrivial topological states of a Bose-Einstein condensate with repulsive atomic interactions confined by an optical lattice. These nonlinear localized states, matter-wave gap vortices, carry a vortexlike phase dislocation and exist in the gaps of the matter-wave band-gap spectrum due to the Bragg scattering. We discuss the structure, stability, and formation dynamics of the gap vortices in the case of two-dimensional optical lattices.
authors.affiliation: Nonlinear Physics Centre and ARC Centre of Excellence for Quantum-Atom Optics, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200, Australia.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Ostrovskaya
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Kivshar