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

Abstract

Magnetic skyrmions are quasiparticles with nontrivial topology, envisioned to play a key role in next-generation data technology while simultaneously attracting fundamental research interest due to their emerging topological charge. In chiral magnetic multilayers, current-generated spin–orbit torques or ultrafast laser excitation can be used to nucleate isolated skyrmions on a picosecond time scale. Both methods, however, produce randomly arranged skyrmions, which inherently limits the precision on the location at which the skyrmions are nucleated. Here, we show that nanopatterning of the anisotropy landscape with a He+-ion beam creates well-defined skyrmion nucleation sites, thereby transforming the skyrmion localization into a deterministic process. This approach allows control of individual skyrmion nucleation as well as guided skyrmion motion with nanometer-scale precision, which is pivotal for both future fundamental studies of skyrmion dynamics and applications.

Local Manipulation of Skyrmion Nucleation in Microscale Areas of a Thin Film with Nitrogen-Ion Implantation

“…One possible approach is to use ion implantation, which is a universal method to uniformly introduce the steerable defects (such as vacancies and interstitials) into materials by modifying the source, energy, or dose of implanted ions. , Recent work employed Ga + - or He + -ion irradiation to manipulate skyrmion nucleation and guide their motion in a defined pattern by creating artificial defects. − To facilitate the industrial application, the ion implantation strategy should be highly compatible with modern LSICT. However, the generation of the above-mentioned ions relies on special equipment, and these ions are not the mainstream implantation sources in the present processing technology of semiconductors, posing a challenge concerning compatibility with modern LSICT.…”

Understanding the Magnetic Microstructure through Experiments and Machine Learning Algorithms

“…Swift heavy ion-induced modification of magnetization dynamics, lattice distortion , and spin reorientation are also topics of contemporary research interest. Of late, deterministic generation and precise tunability of skyrmion density have been achieved using energetic ions. From the point of view of ferrimagnetic thin films, the compensation point and magnetic anisotropy were successfully engineered in Gd–Fe and Tb–Fe thin films using He + , and Ne + ions with various fluences .…”

Dynamic Phases and Reentrant Hall Effect for Vortices and Skyrmions on Periodic Pinning Arrays

“…Simulations of skyrmions with large Magnus forces indicate that clustering effects can also occur [57]. Experimentally, periodic substrates for skyrmions can be produced using nanoscale arrays [18,59,60] or with optical trapping.…”