Formation of Vector Solitary waves with Mixed Dispersion in Bose-Einstein Condensates

We demonstrate the existence of a new class of two-component vector solitary waves in which dispersion coefficients have of opposite signs. Stability is achieved by inclusion of an additional linear coupling between the vector components that counterbalances the instability produced by the mixed dispersion and the non-linearity. In addition, we demonstrate that these solutions are experimentally observable as gap vector solitons in Bose-Einstein condensates located in oscillating optical lattices. The proposed experiment falls well within the standard experimental procedures for generating gap solitons in today's laboratories.