Frustrated out-of-plane Dzyaloshinskii-Moriya interaction and the onset of atomic-scale 3$q$ magnetic textures in 2D Fe$_{3}$GeXTe (X = Te, Se, S) monolayers

TL;DR

This study explores how out-of-plane Dzyaloshinskii-Moriya interaction influences the emergence of atomic-scale 3q magnetic textures in 2D Fe3GeXTe monolayers, revealing tunable magnetic states via DMI strength.

Contribution

It demonstrates the role of frustrated out-of-plane DMI in stabilizing complex magnetic textures and how DMI tuning can induce transitions between magnetic states in 2D materials.

Findings

Out-of-plane DMI favors atomic-scale 3q magnetic textures.

Nonplanar 3q states emerge at low DMI scaling factors.

Larger DMI stabilizes nanoskyrmion-like lattice states.

Abstract

We theoretically study the effect of in- and out-of-plane Dzyaloshinskii-Moriya interaction (DMI) on the magnetic ground states of two-dimensional (2D) Fe$_3$GeXTe (X=Te, Se, S) monolayers, where X=Se, S correspond to antisymmetric Janus structures with nonvanishing in-plane DMI. We perform atomistic spin simulations with the extended Heisenberg Hamiltonian parametrized by first principles calculations. While we find that the base DMI in all systems is too weak to stabilize noncollinear states, we show how the frustrated out-of-plane DMI tends to favor atomic-scale $3q$ magnetic textures at the edge of the Brillouin zone. Owing to the ability to tune the DMI in 2D magnets via applied strain or electric field, we study the evolution of the systems' ground state with increasing DMI amplitude. We find that nonplanar $3q$ states are favored under scaling factors as low as 3, while larger DMI tends to stabilize states reminiscent of nanoskyrmion lattices at the atomic-scale.