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Skyrmions constitute a new magnetic topology that occurs only under specific conditions of
temperature, applied magnetic fields, and only in certain chiral magnets lacking inversion
symmetry. Thanks to their topological stability and the low current density required for the
manipulation of their position, skyrmions constitute a valid alternative to domain walls as
information carriers in spintronic devices [1].
In order to develop skyrmoinic devices, it is important to understand the characteristics and
behaviour of the skyrmion lattice in relation both to external stimuli such as electric fields, and to
the underlying crystal structure. In this context, we have studied the response of the skyrmion
lattice to the electric field in a single crystal of Zn substituted Cu2OSeO3 with small angle
neutron scattering.
On one hand the Zn substitution is observed to shift the position of the skyrmion pocket towards
lower temperatures [2], while the application of an electric field changes the size of the pocket
according to its polarity, in agreement with the know behaviour of pristine material [3].
Moreover, thanks to the effect of the Zn substitution, we have been able to measure the
formation time of the skyrmion lattice, which is longer than its decaying time, suggesting two
different mechanism involved in the two different processes. The formation time increases with
decreasing temperature, allowing us to extract the energy barrier for the formation of the
skyrmion lattice.
This small angle neutron scattering work constitute a step forward towards the understanding of
both chemical substitution, as a way of engineering materials with suitable characteristics for the
development of skyrmionc devices, and of the response of the skyrmion lattice nucleating under
the application of an electric field.
[1] A.Fert, V.Cros, and J.Sampaio. Nat. Nano, 8, 152 (2013), [2] A. Štefančič et al. Phys. Rev. Mat. 2,
111402(R) (2018) [3] J.S. White et al. Phys. Rev. Applied 10, 014021 (2018)
