Experiment on Soliton-Impurity Interaction in Nonlinear Lattice Using LC Circuit

Interaction of a soliton with a mass impurity has been experimentally investigated in a nonlinear electric circuit which is equivalent to an infinite or a semi-infinite exponential lattice. After a soliton collided with a light mass impurity, there remains a localized mode in the vicinity of the impurity. The frequency of the localized mode is above the cut-off frequency of the system, and increases as the mass ratio is decreased. In an infinite system, the soliton amplitude is decreased by a light mass impurity in proportion to the square of mass defect and of the amplitude. In the case of a heavy impurity, the transmitted wave breaks into multiple solitons. In a semi-inifinite system with a light impurity on a surface, the reflected signal is explained by a collisionless shock model.