Chiral standing spin waves in skyrmion lattice

TL;DR

This paper investigates the resonance excitations of three-dimensional skyrmion lattices in chiral magnets, revealing chiral standing spin waves with unique properties influenced by sample thickness, differing from traditional models.

Contribution

It introduces the concept of chiral standing spin waves in skyrmion lattices and demonstrates their dependence on sample thickness, expanding understanding beyond 2D and bulk models.

Findings

Resonance modes differ from 2D and bulk models.

Chiral standing spin waves have helical magnetization profiles.

Mode intensities periodically fade with thickness variations.

Abstract

This work studies the resonance excitations of the three-dimensional skyrmions lattice in the finite thickness plate of an isotropic chiral magnet using spin dynamics simulations. We found that the absorption spectra and resonance modes differ from those predicted by the two-dimensional model and the model of the unconfined bulk crystal. The features observed on the spectra can be explained by the formation of chiral standing spin waves, which, contrary to conventional standing spin waves, are characterized by the helical profile of dynamic magnetization of fixed chirality defined by the Dzyaloshinskii-Moriya interaction. In this case, the dynamic susceptibility becomes a function of the plate thickness, which gives rise to an interesting effect that manifests itself in periodical fading of the intensity of corresponding modes and makes excitation of these modes impossible at specific thicknesses.