Figure 4

Skyrmion nucleation.

(a) Nucleation time of a single skyrmion as a function of the current amplitude for D = 3.5 and 4.0 mJ/m². (b) Snapshot of a single skyrmion and zoom of the skyrmion nucleation region. (c) Snapshot of a skyrmion gas and zoom of the region indicated by a green square in the right frame.