Real-Space Topology-Engineering of Skyrmionic Spin Textures in a van der Waals Ferromagnet Fe₃GaTe₂

Realizing magnetic skyrmions in two-dimensional (2D) van der Waals (vdW) ferromagnets offers unparalleled prospects for future spintronic applications. The room-temperature ferromagnet Fe₃GaTe₂ provides an ideal platform for tailoring these magnetic solitons. Here, skyrmions of distinct topological charges are artificially introduced and engineered by using magnetic force microscopy (MFM). The skyrmion lattice is realized by a specific field-cooling process and can be further erased and painted via delicate manipulation of the tip stray field. The skyrmion lattice with opposite topological charges (S = ±1) can be tailored at the target regions to form topological skyrmion junctions (TSJs) with specific configurations. The delicate interplay of TSJs and spin-polarized device current were finally investigated via the in situ transport measurements, alongside the topological stability of TSJs. Our results demonstrate that Fe₃GaTe₂ not only serves as a potential building block for skyrmion-based spintronic devices, but also presents prospects for Fe₃GaTe₂-based heterostructures with the engineered topological spin textures.