Fig. 2. Characterizing the spin features of merons and antimerons.

a Snapshot of a spin configuration projected along the S^z component (color map) at a selected time with the formation of merons and antimerons at zero magnetic field and 0 K. Some of the topological spin textures are marked as B1–B4 to highlight their features. b Profile of S^z along the dashed lines in a over the distinct spin quasiparticles (B1, B2, B3, B4) showing their widths in Å’s. B1 and B2 are close enough to feel the opposite spin polarization from each other. The largest peak at 0 Å is centered at the center of the meron or antimeron. B2 and B4 have both positive spin polarization with similar peak magnitude at 0 Å (S^z = +1), which is the opposite of B1 and B3. c–f Spin textures of the different quasiparticles stabilized in monolayer CrCl₃. Merons (c, d) and antimerons (e, f) can be determined by the topological number N (Eq. (4)), which involves the vorticity (±1) and the core polarization. B1 and B4 have the same vorticity of +1 even though they are meron (N = −1/2) and antimeron (N = +1/2), respectively. Similar argument applies to B2 and B3, that is, both have vorticity of −1 but are meron and antimeron, respectively. Small arrows (green) indicate the direction and magnitude of the in-plane magnetization relative to the core (zero value). The underneath color gradient shows the variation of S^z around the spin textures. It reaches its maximum magnitude at the core of the merons and antimerons. Large arrows (orange and green) give the average behavior observed around the vortex core by the in-plane magnetization.