Orientational soliton defect in an inhomogeneous hydrogen-bonded chain

The interaction between the orientational soliton defect and the impurity in a hydrogen-bonded chain is investigated. The phase trajectory for motion of orientational kink defect in the impurity region is drawn. In the case of repulsion-type impurities, there exists a critical velocity vc for the incident orientational soliton defect. If the incident velocity v = vc, then its trajectory of motion in phase space will branch while, for v < vc, forbidden regions and allowed regions for its motion will exist. The linear impurity modes for two impurities are discussed in this paper.