Interaction of discrete nonlinear Schr¨odinger solitons with a linear lattice impurity

摘要

The interaction of moving discrete solitons with a linear Gaussian defect is investigated. Solitons with profilesnvarying from hyperbolic secant to exponentially localized are considered such that the mobility of soliton isnmaintained; the condition for which is obtained. Studies on scattering of the soliton by an attractive defectnpotential reveal the existence of total reflection and transmission windows which become very narrow withnincreasing initial soliton amplitude. Transmission regions disappear beyond the small-amplitude limit. Thenregions of complete reflection and partial capture correspond to the windows of the existence and nonexistence ofnsolution of the stationary problem. Interaction of the discrete soliton with a barrier potential is also investigated.nThe critical amplitude of the defect at which splitting of the soliton into two parts occurs was estimated fromna balance equation. The results were confirmed through direct numerical integration of the dynamical equationnshowing very good agreement with the analytical prediction.