Researchers have created a thin film material that allows them to control the size and density of magnetic skyrmions. This is progress towards a skyrmion-based memory device. The potential memory that is smaller by an order of magnitude and uses less power.
The next hurdles the researchers must clear is fabricating devices while ensuring consistency of magnetic properties. The details of the physical mechanisms governing the stabilization of skyrmions in nanostructures, and their reading and writing, remain to be fully established.
Left: Multilayer stack with a sequence of Ir, Fe, Co, and Pt layers. Right: Zoom-in of one Ir/Fe/Co/Pt stack.
Magnetic skyrmions are nanoscale topological spin structures offering great promise for next-generation information storage technologies. The recent discovery of sub-100-nm room-temperature (RT) skyrmions in several multilayer films has triggered vigorous efforts to modulate their physical properties for their use in devices. Here we present a tunable RT skyrmion platform based on multilayer stacks of Ir/Fe/Co/Pt, which we study using X-ray microscopy, magnetic force microscopy and Hall transport techniques. By varying the ferromagnetic layer composition, we can tailor the magnetic interactions governing skyrmion properties, thereby tuning their thermodynamic stability parameter by an order of magnitude. The skyrmions exhibit a smooth crossover between isolated (metastable) and disordered lattice configurations across samples, while their size and density can be tuned by factors of two and ten, respectively. We thus establish a platform for investigating functional sub-50-nm RT skyrmions, pointing towards the development of skyrmion-based memory devices.