Domain walls in two-component dynamical lattices

A study was conducted on the structures and stability of domain-wall (DW) solutions in the system of two discrete nonlinear Schrodinger equations with the coupling of the cross-phase modulation (XPM) type. The consideration of this problem was suggested by the analogy with known DW solutions in a standard model of a nonlinear optical fiber carrying two polarizations of light or two different wavelengths, as well as in the quasi-one-dimensional binary Bose-Einstein condensate (BEC). The results directly apply to an array of fibers of this type, with the anomalous intrinsic diffraction controlled by the direction of the light beam, or to a string of BEC drops trapped in an optical-lattice potential.