Vortex reversal by spin waves

200 ps Vortex Core Reversal by Azimuthal Spin Waves.
Matthias Kammerer, Hermann Stoll, Matthias Noske, Markus Sproll, Markus Weigand, Georg Woltersdorf, and Gisela Schuetz
ArXiv 1112.1903 (2011)

Time-resolved imaging of spin wave mediated vortex core reversal. B: Amplitudes in x and y direction of the CW (left) and CCW (right) rotating bursts of one period at 4:5GHz. A and C: Snapshots in steps of 58:5 ps showing the
out-of-plane magnetization of the excited spin wave during unidirectional reversal of the vortex core polarization from down to up (A) and from up to down (B).