Bound Soliton-Impurity Solutions in Lattices with Cubic-Quintic Nonlinearities

摘要

The discrete nonlinear Schrodinger equation with third- and fifth-order nonlinearities is investigated. Effects of discreteness for the homogeneous case are analyzed. Exact analytical solutions are found for wide static solitons in the presence of impurities. The bound soliton-defect solutions can be single-peak for attractive impurities or double-peak for repulsive impurities. In contrast to the standard cubic nonlinear case, where the positions of the peaks do not depend on the nonlinearity, now they are strongly influenced by the quintic nonlinearity. The model plays an important role in numerous physical systems with complicated nonlinear interactions.