Nanowerk February 13, 2020
When a skyrmion is driven by an electric current it propagates at skyrmion Hall angle (SkHA). This drive dependence, as well as thermal effects due to Joule heating, could be used to tailor skyrmion trajectories, but are not well understood. An international team of researchers (Germany, Belgium, USA – MIT, Czech Republic) had previously demonstrated the use of new spin structures for future magnetic storage devices. In their new research they report skyrmion dynamics as a function of temperature and drive amplitude. They found the skyrmion velocity depends strongly on temperature, while the skyrmion Hall angle (SkHA) does not and instead evolves differently in the low- and high-drive regimes. In particular, the maximum skyrmion velocity in ferromagnetic devices is limited by a mechanism based on skyrmion surface tension and deformation. Their mechanism provides a complete description of the SkHA in ferromagnetic multilayers across the full range of drive strengths, illustrating that skyrmion trajectories can be engineered to serve as magnetic shift registers, racetrack memory devices which promise low access times, high information density, and low energy consumption…read more. TECHNICAL ARTICLE
The researchers observed the magnetic skyrmions in an x-ray microscope on a sample of adjustable temperature. (Image: Kai Litzius)