Figure 4.

Snapshots of skyrmion motion taken at 50 ns intervals. The horizontal dashed line shows the position of the anisotropy step. The moving distances in x and y directions, together with the skyrmions radius, are shown in the figures. The sketch of the device is illustrated at the center of each figure, with the fundamental structure from bottom-up: heavy metal layer (blue), ferromagnetic layer (yellow), metal oxide layer (red) and half-width electrode (white). The effective anisotropy is tuned from 1.6 × 10⁶ J/m³ to (a) 1.7 × 10⁶ J/m³ by applying negative voltage and (b) 1.5 × 10⁶ J/m³ by applying positive voltage.