Recently, a research team led by Professor LU Qingyou at the High Magnetic Field Science Center of the Hefei Institutes of Physical Science, Chinese Academy of Sciences, realized precise writing, deletion, and size tuning of individual magnetic skyrmions using a self-developed low-temperature, high-magnetic-field magnetic force microscope (MFM) integrated with the Steady High Magnetic Field Facility.
The related work was published in Rare Metals.
Magnetic skyrmions are nanoscale spin structures with high stability and low energy consumption, making them promising candidates for next-generation memory and information-processing devices. However, achieving precise and repeatable control of individual skyrmions has remained a major challenge.
In this study, the researchers used the localized oscillating magnetic field generated by the MFM tip together with specially designed magnetic multilayer nanopattern arrays. This approach allowed them to selectively create and erase skyrmions and continuously tune their size. The skyrmion diameter could be adjusted from several hundred nanometers down to only a few tens of nanometers, corresponding to nearly an order-of-magnitude change. In addition, the dynamic magnetic field reduced the critical size required for skyrmion stability, enabling smaller skyrmions to exist stably.
To better understand the mechanism, the team carried out micromagnetic simulations. The results showed that the oscillating local magnetic field created dynamic perturbations in skyrmion structures, weakening pinning effects caused by material defects and grain disorder. This reduced the energy barriers for size tuning and improved both manipulation efficiency and precision.
The researchers further demonstrated independent control of multiple skyrmions within a skyrmion lattice. Individual skyrmions could be adjusted without affecting neighboring structures, highlighting the strong addressability and selectivity of the method for future multi-bit information storage.
"Compared with conventional current-driven approaches, the new strategy offers lower energy consumption, higher precision, and less unintended displacement," explained Prof. FENG Qiyuan, a member of the team.
The study provides a new route for dynamic control of topological spin textures and advances magnetic skyrmions closer to practical applications in future memory, logic, and information-processing devices.
Left: Addressable and Precise Manipulation of Magnetic Skyrmions. Right: Cover Article. (Image by FENG Qiyuan)
