Topological flat bands in skyrmion-semiconductor heterostructures

Chiral magnets have received lots of attention in the past decade or so since the observation of magnetic skyrmions and the topological Hall effect, and work continues with the aim of skyrmion-based information devices. On the other hand, flat Chern bands in moire systems have garnered immense interest recently due to the possibility of realizing a host of strongly correlated phases. Here we explore the intersection and demonstrate the possibility of realizing flat Chern bands in chiral magnet-semiconductor heterostructures hosting skyrmions [1]. We find an almost perfectly flat band for generic skyrmion textures at a ``magic" value of out-of-plane magnetization m=0.2 for parabolic electrons and generally for Dirac electrons. We also point to MoS2/CrBr3 heterostructures as a material realization of such a flat Chern band due to a giant proximity exchange splitting of 14 meV we find from first-principles calculations.

[1] N. Paul, Y. Zhang, and L. Fu ``Giant proximity exchange and flat Chern band in 2D magnet-semiconductor heterostructures" (forthcoming)