Magnetic skyrmions are topologically stable spin textures that exhibit many fascinating features. Amongst them, the efficient manipulation makes magnetic skyrmions as perfect information carriers for the low-power, nonvolatile, electrically reconfigurable data processing technologies. These aspects have been previously demonstrated at cryogenic temperatures in exotic material systems. Using an inhomogeneous in-plane current in a Ta/CoFeB/TaO trilayer, magnetic skyrmion bubbles were “blown” from a geometrical constriction. This can be understood to be the result of spatially divergent spin-orbit torques that give rise to instabilities of the magnetic domain structures. A current versus magnetic field phase diagram for skyrmion formation was determined and the efficient manipulation of these dynamically created skyrmions revealed, including depinning and motion. The topological distinction between magnetic skyrmions and topological trivial bubbles was also demonstrated. The results unambiguously show that spatially divergent current-induced spin-orbit torques can be an effective way for dynamically generating mobile magnetic skyrmions which, therefore, constitutes an important step towards skyrmion-based spintronics – skyrmionics. This dynamic approach for skyrmion generation could enable in the near future the demonstration of advanced skyrmionic device concepts, for example, a functional skyrmion racetrack memory.
Blowing magnetic skyrmion bubbles,
Wanjun Jiang, Pramey Upadhyaya, Wei Zhang, Guoqiang Yu, M. Benjamin Jungflesch, Frank Y. Fradin, John E. Pearson, Yaroslav Tserkovnyak, Kang L. Wang, Olle Heinonen, Suzanne G. E. te Velthuis, and Axel Hoffmann,
Science, 349, 283 (2015).
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Science, 349, 283 (2015).
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Magnetic skyrmion bubbles have been experimentally generated in a way very reminiscent of the process of blowing soap bubbles. This was accomplished at room temperature in readily accessible material systems.