Chiral Magnetic Quasiparticles with Zero Topological Charge in 2D Lattice

Abstract Chiral quasiparticles, such as magnetic skyrmions, are fundamental phenomena in the field of condensed‐matter physics. So far, several chiral quasiparticles with nontrivial topology have been theoretically predicted and experimentally confirmed, most characterized by carrying a nonzero topological charge. Here, through model analysis, a mechanism of realizing chiral magnetic quasiparticles with zero topological charge in the 2D lattice is proposed. The physics is related to the marriage of layer‐dependent staggered Dzyaloshinskii‐Moriya interaction and interlayer exchange interaction, and the nontrivial topology is protected indirectly. By means of first‐principles calculations and atomic spin model simulations, this mechanism in a real material of bilayer Tl 2 NO 2 is further demonstrated. The realized chiral quasiparticles with zero topological charge can be considered as the superposition of vortex and anti‐vortex. Even though the topological charge is zero, their topologies are nontrivial, indirectly protected by the correlated magnetic bimerons. The finding opens up a new direction for the research on topological spin structures in 2D lattice.