Modulational Instability in a Heisenberg Helimagnet Incorporating NNN Interactions

Abstract

We examine the characteristics of nonlinear localized excitations in a one-dimensional Heisenberg helimagnetic spin system incorporating Next Nearest Neighbour (NNN) interactions. By using the Dyson-Maleev transformation and coherent state ansatz, we deduce a discrete nonlinear equation which governs the dynamics of the system. Also, we analyze the propagation dynamics and stability of the localized modes under various exchange interaction parameters using linear stability analysis.