Pinning and movement of individual nanoscale magnetic skyrmions via defects

An understanding of the pinning of magnetic skyrmions to defects is crucial for the development of
future spintronic applications. While pinning is desirable for a precise positioning of magnetic
skyrmions it is detrimental when they are to be moved through a material.Weuse scanning tunneling
microscopy (STM) to study the interaction between atomic scale defects and magnetic skyrmions that
are only a few nanometers in diameter. The studied pinning centers range from single atom inlayer
defects and adatoms to clusters adsorbed on the surface of our model system.Wefind very different
pinning strengths and identify preferred positions of the skyrmion. The interaction between a cluster
and a skyrmion can be sufficiently strong for the skyrmion to follow when the cluster is moved across
the surface by lateral manipulation with the STMtip.