Resonance effects in nonlinear lattices
Dipartimento di Fisica dell'Università, 73100 Lecce, Italy
2 Liceo Scientifico "L. da Vinci", Maglie, 73100 Lecce, Italy
Revised: 3 February 2000
Published online: 15 September 2000
We study a class of one-dimensional nonlinear lattices with nearest-neighbour interactions described by a potential of the binomial type. This potential contains a free parameter which can be chosen to reproduce a variety of models, such as the Toda, the Fermi-Pasta-Ulam and the Coulomb-like lattices. Carrying out essentially numerical experiments, the effects of soliton propagation on a lattice with defects are investigated. In particular, the properties of the localized mode, generated by the propagation of the soliton through the defect, are discussed with respect to the defect mass and the potential parameter, in the light of a simple theoretical model. Furthermore, an interesting phenomenon is observed: the amplitude of the speed of the mass defect shows a sequel of resonance peaks in terms of the mass defect. The positions of these peaks appear to be independent of the potential parameter.
PACS: 63.10.+a – General theory / 05.45.-a – Nonlinear dynamics and nonlinear dynamical systems / 05.45.Yv – Solitons
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000