Skyrmion lattice formation and destruction mechanisms probed with SANS

A magnetic Skyrmions is a local whirl of the spin configuration in a magnetic material. These structures have promising applications in spintronic devices [1] due to their topological protection, which prevents them from being continuously created or destroyed. The formation and destruction time scales of skyrmions are important when it comes to applications. Typically, magnetic dynamics occur on the nanosecond (10-9 s) timeframe, however, the time scale of skyrmion formation may be much longer. In this work, we have measured the dynamics of skyrmion lattice formation in B20 materials MnSi, FeCoSi, Cu2OSeO3 using small-angle neutron scattering. The formation rate of skyrmions was a surprisingly slow 10's of ms. Using a stepped magnetic field, the material is moved into/out of the skyrmion stability window. Using time-domain slicing of the SANS data, the dynamics formation and destruction of the skyrmion lattice is captured in real-time. These results reveal that the formation/destruction dynamics occur between 27-40 ms. 

1.Desautels, R.D., et al., Physical Review Materials, 2019. 3(10).