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arXiv · 1703.10310

Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo films

Seonghoon Woo·Kyung Mee Song·Xichao Zhang·Yan Zhou·Motohiko Ezawa·Xiaoxi Liu·S. Finizio·J. Raabe·Nyun Jong Lee·Sang-Il Kim·Seung-Young Park·Younghak Kim·Jae-Young Kim·Dongjoon Lee·OukJae Lee·Jun Woo Choi·Byoung-Chul Min·Hyun Cheol Koo·Joonyeon Chang
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Abstract

Magnetic skyrmions are swirling magnetic textures with novel characteristics suitable for future spintronic and topological applications. Recent studies confirmed the room-temperature stabilization of skyrmions in ultrathin ferromagnets. However, such ferromagnetic skyrmions show undesirable topological effect, the skyrmion Hall effect, which leads to their current-driven motion towards device edges, where skyrmions could easily be annihilated by topographic defects. Recent theoretical studies have predicted enhanced current-driven behaviour for antiferromagnetically exchange-coupled skyrmions. Here we present the stabilization of these skyrmions and their current-driven dynamics in ferrimagnetic GdFeCo films. By utilizing element-specific X-ray imaging, we find that the skyrmions in the Gd and FeCo sublayers are antiferromagnetically exchange-coupled. We further confirm that ferrimagnetic skyrmions can move at a velocity of ~50 m s-1 with reduced skyrmion Hall angle, {\theta}SkHE ~20{\deg}. Our findings open the door to ferrimagnetic and antiferromagnetic skyrmionics while providing key experimental evidences of recent theoretical studies.

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Seonghoon Woo, Kyung Mee Song, Xichao Zhang, Yan Zhou, Motohiko Ezawa, Xiaoxi Liu, S. Finizio, J. Raabe, Nyun Jong Lee, Sang-Il Kim, Seung-Young Park, Younghak Kim, Jae-Young Kim, Dongjoon Lee, OukJae Lee, Jun Woo Choi, Byoung-Chul Min, Hyun Cheol Koo, Joonyeon Chang. 2017-03-30. Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo films. https://doi.org/10.1038/s41467-018-03378-7

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