Engineering solitons and breathers in a deformed ferromagnet: Effect of localised inhomogeneities

TL;DR

This paper explores how electromagnetic solitons and breathers behave in a deformed ferromagnet with localized inhomogeneities, using numerical simulations of a derived nonlinear integro-differential equation.

Contribution

It derives a perturbed integral mKdV equation from the Landau-Lifshitz-Maxwell system and studies soliton interactions with inhomogeneities through numerical simulations, revealing new dynamical phenomena.

Findings

Soliton interactions with inhomogeneities can produce bound states or breathers.

Numerical simulations show complex collision dynamics leading to new soliton structures.

Localized inhomogeneities significantly affect soliton propagation and interactions.

Abstract

We investigate the soliton dynamics of the electromagnetic wave propagating in an inhomogeneous or deformed ferromagnet. The dynamics of magnetization and the propagation of electromagnetic waves are governed by the Landau-Lifshitz-Maxwell (LLM) equation, a certain coupling between the Landau-Lifshitz and Maxwell's equations. In the framework of multiscale analysis, we obtain the perturbed integral modified KdV (PIMKdV) equation. Since the dynamic is governed by the nonlinear integro-differential equation, we rely on numerical simulations to study the interaction of its mKdV solitons with various types of inhomogeneities. Apart from simple one soliton experiments with periodic or localised inhomogeneities, the numerical simulations revealed an interesting dynamical scenario where the collision of two solitons on a localised inhomogeneity create a bound state which then produces either two separated solitons or a mKdV breather.