Measuring the formation energy barrier of skyrmions in zinc-substituted Cu2OSeO3.

We report small-angle neutron scattering (SANS) measurements of the skyrmion lattice in (Cu0.976Zn0.024 )2OSeO3 under the application of electric and magnetic fields. These measurements show an expansion of the skyrmion lattice stability region with electric field. Furthermore, using time-resolved SANS, we observe the slow formation of skyrmions after an electric or magnetic field is applied, which has not been observed in pristine Cu2OSeO3 crystals. The measured formation times are dramatically longer than the corresponding skyrmion annihilation times after the external field is removed, and increase exponentially from 100 s at 52.5 K to 10 000 s at 51.5 K. This thermally activated behavior indicates an energy barrier for skyrmion formation of 1.57(2) eV, the size of which demonstrates the huge cost for creating these complex chiral objects