Figure 2: Magnetization process of a chiral magnet.

(a)→(b)→(c)→(d)→(e) The time evolution in the magnetic texture. The colour code (m) is the same as in Fig. 1. (a) Initial state. The system size is L=300 × 300. (b–e) The snapshots of magnetic structure at t=2,110, 2,300, 2,369 and 4,000 in units of 1/(γJ), respectively. The close-ups of the regions enclosed by the red squares (50 × 50) in b–d are shown in f–h, respectively. (i–l) The spatial distribution of the solid angle formed by four magnetic moments on plaquette, for the magnetic textures shown in e–h, respectively. The scale of b_z is shown in n. Blue indicates the skyrmion, while red indicates the antiskyrmion. (o) Time dependence of skyrmion number N_sk (black) and z-component of total magnetic moment divided by system size L (red). The blue vertical broken lines indicates t=2,110, 2,300 and 2,369, respectively. See Supplementary Movies 1–4.