Néel-type skyrmion in WTe2/Fe3GeTe2 van der Waals heterostructure

Abstract

The promise of high-density and low-energy-consumption devices motivates the search for layered structures that stabilize chiral spin textures such as topologically protected skyrmions. At the same time, recently discovered long-range intrinsic magnetic orders in the two-dimensional van der Waals materials provide a new platform for the discovery of novel physics and effects. Here we demonstrate the Dzyaloshinskii-Moriya interaction and Néeltype skyrmions are induced at the WTe 2 /Fe 3 GeTe 2 interface. Transport measurements show the topological Hall effect in this heterostructure for temperatures below 100 K. Furthermore, Lorentz transmission electron microscopy is used to directly image Néel-type skyrmion lattice and the stripe-like magnetic domain structures as well. The interfacial coupling induced Dzyaloshinskii-Moriya interaction is estimated to have a large energy of 1.0 mJ m −2. This work paves a path towards the skyrmionic devices based on van der Waals layered heterostructures.

Néel-type skyrmions and their current-induced motion in van der Waals ferromagnet-based heterostructures

“…Once established, by taking advantages of other 2D crystals that are stackable and offer unique electrical properties [1,2], this material platform could provide a different route towards skyrmion-based devices that have been challenging with conventional metallic ferromagnets [20,21]. Recently, skyrmionlike spin textures have been observed experimentally in exfoliated vdW ferromagnet materials (e.g., FGT and Cr 2 Ge 2 Te 6 ) and their heterostructures with the magnetic fields [22][23][24][25][26]. However, both Bloch-type and Néel-type skyrmions of the previous results have still been a subject of controversy.…”

Magnetic domains and domain wall pinning in atomically thin CrBr3 revealed by nanoscale imaging

“…Despite many significant results, these methods have limited spatial resolution due to the laser diffraction limit and electrode size. The nanoscale features of the atomically thin vdW magnets, such as magnetic domains [15][16][17] and topological spin textures [18][19][20][21] , are largely unexplored. For example, magnetic domains in layered CrBr 3 have been predicted from its anomalous hysteresis loop in magneto-photoluminescence and micromagnetometry measurements 15,16 , but the magnetic domain structure and its evolution has not been detected in real space.…”

Tunable Magnetic Anisotropy and Dzyaloshinskii-Moriya Interaction in an Ultrathin van der Waals Fe3GeTe2/In2Se3 Heterostructure

“…Using criticality analysis, Tan et al [20] have demonstrated that the coupling length between vdW layers in Fe 3 GeTe 2 is estimated to be 5 layers. Wu et al [45] have confirmed that the increasing of the thickness of FGT up to 4-60 layers will lead to greatly enhanced DM interaction. In short, we have demonstrated that the strong SOC in the In 2 Se 3 layers does induce an interfacial DM interaction at the interface with FGT, and have achieved the robust manipulation of DM interaction in the Fe 3 GeTe 2 /In 2 Se 3 heterostructure.…”

“…To validate the plausible mechanism of ferroelectricallydriven DM interaction, we performed first-principles calculation on the FGT/In 2 Se 3 HS (see Supplementary Information for may be result of the broken inversion symmetry and the strong SOC effect [45,46]. Our FGT/In 2 Se 3 HS has the polarizationdependent DM interaction, which can be used in skyrmionbased racetrack memory.…”