Movability of Localized Excitations in Nonlinear Discrete Systems - a Separatrix Problem
Condensed Matter
2009-10-22 v1
Abstract
We analyze the effect of internal degrees of freedom on the movability properties of localized excitations on defect-free nonlinear Hamiltonian lattices by means of properties of a local phase space which is at least of dimension six. We formulate generic properties of a movability separatrix in this local phase space. We prove that due to the presence of internal degrees of freedom of the localized excitation it is generically impossible to define a Peierls-Nabarro potential in order to describe the motion of the excitations through the lattice. The results are verified analytically and numerically for Fermi-Pasta-Ulam chains.
Keywords
Cite
@article{arxiv.cond-mat/9403053,
title = {Movability of Localized Excitations in Nonlinear Discrete Systems - a Separatrix Problem},
author = {S. Flach and C. R. Willis},
journal= {arXiv preprint arXiv:cond-mat/9403053},
year = {2009}
}
Comments
11 pages, LaTeX, 2 Figures, available upon request, accepted for publication in Phys.Rev.Lett