Coupling Multi-Space Topologies in 2D Ferromagnetic Lattice

Abstract

Topology can manifest topological magnetism (e.g., skyrmion and bimeron) in real space and quantum anomalous Hall (QAH) state in momentum space, which has changed the modern conceptions of matter phase. While the topologies in different spaces are widely studied separately, their coexistence and coupling in a single phase are seldom explored. Here, a novel phenomenon is reported that arises from the interaction of topological magnetism and band topology, the multi-space topology, in 2D ferromagnetic lattice. Based on continuum theory and tight-binding model, it is revealed that the interconnection between skyrmion/bimeron and QAH state generates distinctive localized chiral bound states (CBSs). With moderating topological magnetism through a magnetic field, the multi-space topologies accompanied with different CBSs can be reversed, facilitating the coupling of multi-space topologies. By performing first-principles and atomic spin model simulations, such multi-space topologies and their coupling in monolayer Cr₂NSb are further demonstrated. These results represent an important step toward the development of multi-space topological phenomena in 2D lattice.