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, layered structures provide a new platform for the discovery of new physics and effects. Recently discovered long-range intrinsic magnetic orders in the two-dimensional van der Waals materials offer new opportunities. Here we demonstrate the Dzyaloshinskii-Moriya interaction and N\'eel-type skyrmions are induced at the WTe2/Fe3GeTe2 interface. Fe3GeTe2 is a ferromagnetic material with strong perpendicular magnetic anisotropy. We demonstrate that the strong spin orbit interaction in 1T'-WTe2 does induce a large interfacial Dzyaloshinskii-Moriya interaction at the interface with Fe3GeTe2 due to the inversion symmetry breaking to stabilize skyrmions. 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 N\'eel-type skyrmions along with aligned and stripe-like domain structure. This interfacial coupling induced Dzyaloshinskii-Moriya interaction is estimated to have a large energy of 1.0 mJ/m^2, which can stabilize the N\'eel-type skyrmions in this heterostructure. This work paves a path towards the skyrmionic devices based on van der Waals heterostructures.
@article{arxiv.1907.11349,
title = {N\'eel-type skyrmion in WTe2/Fe3GeTe2 van der Waals heterostructure},
author = {Yingying Wu and Senfu Zhang and Gen Yin and Junwei Zhang and Wei Wang and Yang Lin Zhu and Jin Hu and Kin Wong and Chi Fang and Caihua Wan and Xiufeng Han and Qiming Shao and Takashi Taniguchi and Kenji Watanabe and Jiadong Zang and Zhiqiang Mao and Xixiang Zhang and Kang L. Wang},
journal= {arXiv preprint arXiv:1907.11349},
year = {2020}
}