Electromagnetic breathing dromion-like structures in an anisotropic ferromagnetic medium

TL;DR

This paper theoretically investigates how Gilbert damping affects electromagnetic wave propagation in anisotropic ferromagnetic media, revealing complex nonlinear structures like breathing solitons and dromion-like modes through a derived damped nonlinear Schrödinger equation.

Contribution

It introduces a new theoretical framework using the LLG and Maxwell equations to describe nonlinear EMW dynamics with damping, uncovering novel dromion-like excitations in ferromagnetic media.

Findings

Identification of breathing solitons and dromion-like modes

Discovery of creation-annihilation excitation modes

Analysis of damping effects on nonlinear wave structures

Abstract

The influence of Gilbert damping on the propagation of electromagnetic waves (EMWs) in an anisotropic ferromagnetic medium is investigated theoretically. The interaction of the magnetic field component of the electromagnetic wave with the magnetization of a ferromagnetic medium has been studied by solving the associated Maxwell's equations coupled with a Landau-Lifshitz-Gilbert (LLG) equation. When small perturbations are made on the magnetization of the ferromagnetic medium and magnetic field along the direction of propagation of electromagnetic wave by using the reductive perturbation method, the associated nonlinear dynamics is governed by a time-dependent damped derivative nonlinear Schrodinger (TDDNLS) equation. The Lagrangian density function is constructed by using the variational method to solve the TDDNLS equation to understand the dynamics of the system under consideration. The propagation of EMW in a ferromagnetic medium with inherent Gilbert damping admits very interesting nonlinear dynamical structures. These structures include Gilbert damping-managing symmetrically breathing solitons, localized erupting electromagnetic breathing dromion-like modes of excitations, breathing dromion-like soliton, decaying dromion-like modes and an unexpected creation-annihilation mode of excitations in the form of growing-decaying dromion-like modes.