Localization of two-component Bose-Einstein condensates in optical lattices

A one-dimensional optical lattice was investigated in order to study nonlinear localization of a two-component Bose-Einstein Condensate (BEC) and the formation of composite atomic solitons in it. Mean-field equations for the wave functions of the condensate component were used for modeling the two-component BEC with repulsive interactions. It was found that the effective nonlinear interactions both within and between the BEC components could be modified by the use of optical lattices, without the Feshbach resonance manipulation of scattering lengths. Moreover, in the gaps and bands of the linear Bloch-wave spectrum, nonlinear localization of coherent matter waves could be achieved.