Publication Date
2006
Journal or Book Title
Physics Letters A
Abstract
We derive a class of discrete nonlinear Schrödinger (DNLS) equations for general polynomial nonlinearity whose stationary solutions can be found from a reduced two-point algebraic problem. It is demonstrated that the derived class of discretizations contains subclasses conserving classical norm or a modified norm and classical momentum. These equations are interesting from the physical standpoint since they support stationary discrete solitons free of the Peierls–Nabarro potential. Focusing on the cubic nonlinearity we then consider a small perturbation around stationary soliton solutions and, solving corresponding eigenvalue problem, we (i) demonstrate that solitons are stable; (ii) show that they have two additional zero-frequency modes responsible for their effective translational invariance; (iii) derive semi-analytical solutions for discrete solitons moving at slow speed. To highlight the unusual properties of solitons in the new discrete models we compare them with that of the classical DNLS equation giving several numerical examples.
Pages
324-332
Volume
356
Issue
4-5
Recommended Citation
Dmitriev, S V. and Kevrekidis, PG, "Discrete nonlinear Schrödinger equations free of the Peierls–Nabarro potential" (2006). Physics Letters A. 1128.
Retrieved from https://scholarworks.umass.edu/math_faculty_pubs/1128
Comments
This is the pre-published version harvested from arXiv. The published version is located at http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVM-4JM0TFT-1&_user=1516330&_coverDate=08%2F14%2F2006&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000053443&_version=1&_urlVersion=0&_userid=1516330&md5=bd8d57bcddd4f6151706b2e46e13f8b8&searchtype=a