Movie S1.

Lemon skyrmion, dynamics of the S1,2,3 Stokes maps on a 90- × 90-μm2-wide area and with time step of 0.5ps. The top line shows the associated azimuthal profiles computed along the real-space circle represented in the maps, as in the case of Fig. 2 E–H. The initially flat profile of the S3 circular degree of polarization grows in time assuming a sinusoidal modulation as large as the other two Stokes parameters.