Helicon solitons in a layered semiconductor plasma via Zakharov equations

Abstract

In the present work we investigate the propagation of helicon envelope solitons in a layered semiconductor plasma. The nonlinear evolution equations governing the propagation of these envelope solitons is the set of Zakharov equations (which are a more generalized form of the nonlinear Schrödinger equation). The set of equations which have a known envelope soliton solution are derived and the relationship between various parameters entering the system is established. In order to investigate the propagation of helicon envelope solitons in a layered medium we use the standard Kronig - Penney model along with its relevant boundary conditions. These boundary conditions are used for the envelope soliton solution thereby connecting the envelope soliton fields across the layers. This in turn leads to a nonlinear dispersion relation which relates the nonlinear analogue of the Bloch wave number with different parameters. We have numerically investigated the dependence of the nonlinear Bloch wave number on the propagation frequency and have established a propagation band and gap structure for the helicon envelope soliton in a layered semiconductor plasma.