  Magnetic skyrmions are the self-organized topological spin textures behaving
like particles. Because of their fast creation and typically long lifetime,
experimental verification of skyrmion's creation/annihilation processes has
been challenging. Here we successfully track skyrmions dynamics in
defect-introduced Co9Zn9Mn2, by using pump-probe Lorentz transmission electron
microscope. Following the nanosecond-photothermal excitation, we resolve
160-nm-skyrmion's proliferation at <1 ns, contraction at 5 ns, drift from 10 ns
to 4 microsecond and coalescence at 5 microsecond. These motions relay the
multiscale arrangement and relaxation of skyrmion clusters in a repeatable
cycle of 20 kHz. Such repeatable dynamics of skyrmions, arising from the
weakened but still persistent topological protection around defects, enables us
to visualize the whole life of the skyrmions, as well as demonstrating the
possible high-frequency manipulations of topological charges brought by
skyrmions.
