Two-Dimensional Rare-Earth-Based Half-Metals with Topological Bimerons

Two-dimensional magnets with spontaneous topological spin textures have important application prospects in highly integrated spintronic devices. However, so far, the predicted two-dimensional magnets with topological spin textures are mainly based on transition metals, and most of them are semiconductors or metals. Here, based on first-principles calculations, we predict two-dimensional rare-earth-based half-metallic monolayer GdA2N4 (A = Ge, Sn), with 100% spin polarization. Spontaneous topological spin textures, i.e., bimeron clusters, are revealed in those monolayers due to the magnetic frustration and easy-plane magnetic anisotropy. The bimeron clusters can be efficiently tuned through biaxial strain and driven by in-plane spin-polarized current. These results underscore the promising potential of rare-earth-based two-dimensional half-metals for spintronic device applications.