van der Waals heterostructure*

Topologically protected skyrmions are highly promising for spintronic devices and applications. Recently, long-range intrinsic magnetic orders in the van der Waals materials provide a new platform for the discovery of novel physics and phenomena. In this work, we demonstrate the Dzyaloshinskii-Moriya interaction and Néel-type skyrmions are induced at the WTe₂/Fe₃GeTe₂ interface, a van der Waals heterostructure. Topological Hall effect has been observed in this heterostructure for temperatures below 100 K. In addition, we use Lorentz transmission electron microscopy and successfully obtain images of Néel-type skyrmion lattice and the stripe-like magnetic domain structures. These are direct evidence for the skyrmions. Furthermore, we estimate interfacial coupling induced Dzyaloshinskii-Moriya interaction in this system, which has a large energy of 1.0 mJm^-2. This work first time points out a new direction of spintronics in van der Waals layered heterostructures.