title: Driving defect modes of Bose-Einstein condensates in optical lattices.
abstract: We present an approximate analytical theory and direct numerical computation of defect modes of a Bose-Einstein condensate loaded in an optical lattice and subject to an additional localized (defect) potential. Some of the modes are found to be remarkably stable and can be driven along the lattice by means of a defect moving following a steplike function defined by the period of Josephson oscillations and the macroscopic stability of the atoms.
authors.affiliation: Centro de Física Teórica e Computacional, Universidade de Lisboa, Complexo Interdisciplinar, Avenida Profesor Gama Pinto 2, Lisbon 1649-003, Portugal.
authors.forename: Valeriy A
authors.initials: VA
authors.lastname: Brazhnyi
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Konotop
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Pérez-García