N\'eel-type skyrmions and their current-induced motion in van der Waals ferromagnet-based heterostructures

TL;DR

This paper reports the discovery and manipulation of Neel-type skyrmions in a 2D van der Waals ferromagnet, demonstrating current-driven control and interface engineering for potential spintronic applications.

Contribution

It provides the first experimental observation of Neel-type skyrmions in a 2D vdW magnet and elucidates the interface-driven origin of DMI, enabling engineered chiral magnetic textures.

Findings

Observation of Neel-type skyrmions in Fe3GeTe2.

Demonstration of current-driven skyrmion motion.

Identification of interface oxides as DMI origin.

Abstract

Since the discovery of ferromagnetic two-dimensional (2D) van der Waals (vdW) crystals, significant interest on such 2D magnets has emerged, inspired by their appealing properties and integration with other 2D family for unique heterostructures. In known 2D magnets, spin-orbit coupling (SOC) stabilizes perpendicular magnetic anisotropy (PMA). Such a strong SOC could also lift the chiral degeneracy, leading to the formation of topological magnetic textures such as skyrmions through the Dzyaloshinskii-Moriya interaction (DMI). Here, we report the experimental observation of N\'eel-type chiral magnetic skyrmions and their lattice (SkX) formation in a vdW ferromagnet Fe3GeTe2 (FGT). We demonstrate the ability to drive individual skyrmion by short current pulses along a vdW heterostructure, FGT/h-BN, as highly required for any skyrmion-based spintronic device. Using first principle calculations supported by experiments, we unveil the origin of DMI being the interfaces with oxides, which then allows us to engineer vdW heterostructures for desired chiral states. Our finding opens the door to topological spin textures in the 2D vdW magnet and their potential device application.