Scattering of solitons from point defects in two coupled Ablowitz-Ladik chains

The interaction of solitons with point defects in a system of coupled Ablowitz-Ladik (AL) chains is studied numerically. The system is a discrete analog of coupled nonlinear Schrodinger equations. The interchain coupling which couples opposite sites of the AL chains includes linear and nonlinear interactions. The soliton dynamics depends on the soliton parameters (width, velocity), interchain coupling constant and defect strength. It is obtained that solitons which are exited in one of the two chains can be perfectly switched and at the same time transmitted, trapped or reflected by the attractive impurities. The point defects do not influence the period of energy transfer and it is close to the period for the homogeneous case.