Two-Dimensional\nRare-Earth-Based Half-Metals with\nTopological Bimerons

Two-dimensional\nmagnets with spontaneous topological spin textures\nhave important application prospects in highly integrated spintronic\ndevices. However, so far, the predicted two-dimensional magnets with\ntopological spin textures are mainly based on transition metals, and\nmost of them are semiconductors or metals. Here, based on first-principles\ncalculations, we predict two-dimensional rare-earth-based half-metallic\nmonolayer GdA<sub>2</sub>N<sub>4</sub> (A = Ge, Sn), with 100% spin\npolarization. Spontaneous topological spin textures, i.e., bimeron\nclusters, are revealed in those monolayers due to the magnetic frustration\nand easy-plane magnetic anisotropy. The bimeron clusters can be efficiently\ntuned through biaxial strain and driven by in-plane spin-polarized\ncurrent. These results underscore the promising potential of rare-earth-based\ntwo-dimensional half-metals for spintronic device applications.