Figure 3

(a) Snapshots of the nucleation steps of isolated AFM skyrmion using a vertically injected spin-polarized current (STT) perpendicular-to-plane (CPP) of the 2D AFM layer in a circular region (yellow circular). (b) The time evolution of topological charge QA and QB during the nucleation. (c,d) Snapshots of isolated AFM and FM skyrmions after the nucleation time.