Effects of Impurities on Existence and Propagation of Intrinsic Localized Modes in Ferromagnetic Spin Chains

Abstract

The phenomenon of linear localization on the impurities in the periodic structures is very well known. A few decades ago, nonlinear localized waves in ideal periodic lattices have been discovered[1]. Although a great deal of theoretical studies[2, 3, 4] has been devoted to this subject, the existence of intrinsic localized modes (ILM) is still not confirmed experimentally. Thinking about this confirmation we have to take in account the fact that it is impossible to realize an ideal periodic structure in an experiment. There is a certain amount of impurities present in any however clean experimental sample. Therefore, here we investigate the question of coexistence and interaction of localized modes on impurities and intrinsic nonlinear localized modes. We begin by an outline of the properties of nonlinear localized modes in ideal ferromagnet [5]. Linear localization on defects is described in Ref[6].