Beschreibung
We examine the chiral function in the polarized magnetic small-angle neutron
scattering (SANS) cross section resulting from vortex-type and skyrmion spin
structures through numerical micromagnetic simulations. Using the materials
parameters of FeGe and adopting a cylinder geometry, we consider the interplay
between the isotropic exchange interaction, the Dzyaloshinskii-Moriya interaction
(DMI), a uniaxial magnetic anisotropy, a Zeeman energy, and the magnetodipolar
interaction. We compare results with and without the DMI to understand its influence
on the emergence of skyrmions and their signature in the chiral function. Our
numerical computations are compared to an analytical trial field for the unit
magnetization vector that is able to reproduce vortices as well as Bloch and Néel
skyrmions. We show that, for the given system Hamiltonian and particle geometry,
pure Néel skyrmions do not correspond to an energy minimum and yield a vanishing
chiral function.
