Modulational Instability, Ion-Acoustic Envelope Solitons, and Rogue Waves in Four-Component Plasmas

Abstract

Modulational instability (MI) of ion-acoustic waves (IAWs) has been theoretically investigated in a plasma system which is composed of inertial warm adiabatic ions, isothermal positrons, and two-temperature super-thermal electrons (cool and hot). A nonlinear Schrödinger equation (NLSE) is derived by using reductive perturbation method that governs the MI of the IAWs. The numerical analysis of the solution of NLSE shows the existence of both stable (dark envelope solitons) and unstable (bright envelope solitons and rogue waves) regimes of IAWs. It is observed that the basic features (viz., stability of the wave profile and MI growth rate) of the IAWs are significantly modified by the superthermality of electrons and related plasma parameters. The results of our present investigation should be useful for understanding different nonlinear phenomena in both space (viz., Saturn’s magnetosphere and interplanetary medium) and laboratory plasmas (viz., hot-cathode discharge and high-intensity laser irradiation).