Deterministic Generation and Guided Motion of Magnetic Skyrmions by Focused He+-Ion Irradiation

Magnetic skyrmions are quasiparticles with nontrivial top-ology, envisioned to play a key role in next-generation data technology whilesimultaneously attracting fundamental research interest due to their emergingtopological charge. In chiral magnetic multilayers, current-generated spin-orbit torques or ultrafast laser excitation can be used to nucleate isolatedskyrmions on a picosecond time scale. Both methods, however, producerandomly arranged skyrmions, which inherently limits the precision on thelocation at which the skyrmions are nucleated. Here, we show thatnanopatterning of the anisotropy landscape with a He+-ion beam createswell-defined skyrmion nucleation sites, thereby transforming the skyrmionlocalization into a deterministic process. This approach allows control ofindividual skyrmion nucleation as well as guided skyrmion motion with nanometer-scale precision, which is pivotal for both futurefundamental studies of skyrmion dynamics and applications