Elusive Dzyaloshinskii-Moriya interaction in Fe$_3$GeTe$_2$ monolayer

TL;DR

This study investigates the Dzyaloshinskii-Moriya interaction in Fe$_3$GeTe$_2$ monolayer, revealing its limited role in skyrmion formation but potential in boundary magnetic textures and homochiral structures.

Contribution

The paper provides a detailed symmetry and density functional theory analysis of the Dzyaloshinskii-Moriya interaction in Fe$_3$GeTe$_2$ monolayer, highlighting its effects and limitations.

Findings

Dzyaloshinskii-Moriya interaction causes small short-range magnetic distortions.

Long-range Dzyaloshinskii-Moriya favors in-plane Nel spin-spirals.

Observed skyrmions are not explained by Dzyaloshinskii-Moriya interaction at monolayer level.

Abstract

Using symmetry analysis and density functional theory calculations, we uncover the nature of Dzyaloshinskii-Moriya interaction in Fe$_3$GeTe$_2$ monolayer. We show that while such an interaction might result in small distortion of the magnetic texture on the short range, on the longrange Dzyaloshinskii-Moriya interaction favors in-plane N\'eel spin-spirals along equivalent directions of the crystal structure. Whereas our results show that the observed N\'eel skyrmions cannot be explained by the Dzyaloshinskii-Moriya interaction at the monolayer level, they suggest that canted magnetic texture shall arise at the boundary of Fe$_3$GeTe$_2$ nanoflakes or nanoribbons and, most interestingly, that homochiral planar magnetic textures could be stabilized.