2017/03/31 by Seonghoon Woo, Kyung Mee Song, Xichao Zhang +16 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41467-018-03378-7
published as Nature Communications 9, 959 (2018) · 24 pages, 3 figures
arxiv created 2018/01/30 · arxiv updated 2018/03/07
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, θSkHE ~20°. Our findings open the door to ferrimagnetic and antiferromagnetic skyrmionics while providing key experimental evidences of recent theoretical studies.