Quartic asymmetric exchange for two-dimensional ferromagnets with trigonal prismatic symmetry

Abstract

We suggest a possible origin of noncollinear magnetic textures in ferromagnets (FMs) with the $D_{3h}$ point group symmetry. The suggested mechanism is different from the Dzyaloshinskii-Moriya interaction (DMI) and its straightforward generalizations. The considered symmetry class is important because a large fraction of all single-layer intrinsic FMs should belong to it. In particular, so does a monolayer Fe${}_3$GeTe${}_2$. At the same time, DMI vanishes identically in materials described by this point group, in the continuous limit. We use symmetry analysis to identify the only possible contribution to the free energy density in two dimensions that is of the fourth order with respect to the local magnetization direction and linear with respect to its spatial derivatives. This contribution predicts long-range conical magnetic spirals with both the average magnetization and the average chirality dependent on the spiral propagation direction. We relate the predicted spirals to a recent experiment on Fe${}_3$GeTe${}_2$. Finally, we demonstrate that, for easy-plane materials, the same mechanism may stabilize bimerons.

7 pages, 4 figures, 1 table

References in corpus (13)

• Electric Field Effect in Atomically Thin Carbon Films
• Two Dimensional Atomic Crystals
• 2D materials and van der Waals heterostructures
• Magnetic 2D materials and heterostructures
• Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
• Magnetic skyrmion logic gates: conversion, duplication and merging of skyrmions
• Two dimensional magnets: Forgotten history and recent progress towards spintronic applications
• Magnetic structure of monatomic Fe chains on Re(0001): emergence of chiral multi-spin interactions
• Elusive Dzyaloshinskii-Moriya interaction in Fe${}_3$GeTe${}_2$ monolayer
• Boundary-Driven Twist States in Systems with Broken Spatial Inversion Symmetry
• Twists in Ferromagnetic Monolayers With Trigonal Prismatic Symmetry
• Non-collinear ground state from a four-spin chiral exchange in a tetrahedral magnet
• Antichiral Ferromagnetism

Cited by in corpus (4)

• Imaging current control of magnetization in Fe${}_3$GeTe${}_2$ with a widefield nitrogen-vacancy microscope
• Electron transport and scattering mechanisms in ferromagnetic monolayer Fe${}_3$GeTe${}_2$
• An effective spin model on the honeycomb lattice for the description of magnetic properties in two-dimensional Fe${}_3$GeTe${}_2$
• Non-Lifshitz invariants corrections to Dzyaloshinskii-Moriya interaction energy