Signatures of quartic asymmetric exchange in a class of two dimensional magnets

TL;DR

This paper investigates how quartic asymmetric exchange interactions influence magnon spectra and magnetic textures in two-dimensional trigonal prismatic magnets, providing a symmetry-based framework for experimental quantification.

Contribution

It introduces a micromagnetic energy term linear in magnetization gradients to describe quartic interactions and explores their signatures in magnon spectra and magnetic spiral manipulation.

Findings

Quartic interactions affect magnon spectra in 2D magnets.

Magnetic spirals can be controlled by external magnetic fields.

Symmetry considerations enable quantification of interaction strength.

Abstract

Indirect quartic interaction of spins is suggested to play an important role in two dimensional magnets with trigonal prismatic symmetry such as Fe$_3$GeTe$_2$ monolayer. The proposed interaction is described by terms in micromagnetic energy that are linear in magnetization gradients. Such terms enable the stability of non-collinear magnetic textures. We investigate signatures of the quartic interaction in magnon spectra in the presence of anisotropy and external magnetic field. We also show how magnetic spirals, which are induced by the proposed interaction, can be manipulated by external field. Our analysis is based on symmetry considerations and can be used to quantify the quartic interaction strength in experiments with magnetic monolayers.