PHYSICALLY CORRECTED ABLOWITZ-LADIK MODEL AND ITS APPLICATION TO THE PEIERLS-NABARRO PROBLEM

By means of Backlund transformations the Ablowitz-Ladik model has been converted into its physically corrected twin appropriate for physical applications. On the basis of perturbation theory for solitons the dynamics of one-soliton excitations for the standard discrete version of the nonlinear Schrodinger equation has been investigated. Above some critical value of the localization parameter the soliton of the standard version is shown to be self-trapped in the Peierls-Nabarro potential relief irrespective of any variations of the total energy. The critical value of the localization parameter has been calculated.