  Micromagnetic simulations have been performed to investigate the
controllability of the skyrmion position in antiferromagnetic nanotracks with
their magnetic properties modified spatially. In this study we have modeled
magnetic defects as local variations on the material parameters, such as the
exchange stiffness, saturation magnetization, perpendicular magnetocrystalline
anisotropy and Dzyaloshinskii-Moriya constant. Thus, we have observed not only
pinning (potential well) but also scattering (potential barrier) of
antiferromagnetic skyrmions, when adjusting either a local increase or a local
reduction for each material parameter. In order to control of the skyrmion
motion it is very important to impose certain positions along the nanotrack
where the skyrmion can stop. Magnetic defects incorporated intentionally in
antiferromagnetic racetracks can be useful for such purpose. In order to
provide guidelines for experimental studies, we vary both material parameters
and size of the modified region. The found results show that the efficiency of
skyrmion trap depends on a suitable combination of magnetic defect parameters.
Furthermore, we discuss the reason why skyrmions are either attracted or
repelled by a region magnetically modified.
