Current-Driven Dynamics of Frustrated Skyrmions in a Synthetic Antiferromagnetic Bilayer
Current-Driven Dynamics of Frustrated Skyrmions in a Synthetic Antiferromagnetic Bilayer
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DOI：
10.1103/physrevapplied.11.044046
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发表时间：
2018-12
影响因子：
4.6
通讯作者：
J. Xia;Xichao Zhang;M. Ezawa;Z. Hou;Wenhong Wang;Xiaoxi Liu;Yan Zhou
中科院分区：
文献类型：
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作者：
J. Xia;Xichao Zhang;M. Ezawa;Z. Hou;Wenhong Wang;Xiaoxi Liu;Yan Zhou
报道了反铁磁交换耦合双层系统中受阻天米子的电流驱动动力学，其中双层天米子由两个具有相反天米子数$q的单层天米子组成。结果表明，面内电流驱动的双层天米子沿直线运动，而面外电流驱动的双层天米子沿圆形路径运动。结果表明，在较大的β/α比下，双层天米子的面内电流驱动迁移率比单层天米子好得多，其中α和α分别表示阻尼参数和非绝热自旋转移扭矩强度。此外，当α$较小时，双层天空离子的离面电流驱动迁移率要比单层天空离子好得多。我们还发现，在面外电流的驱动下，一个双层Skyrmion(由单层Skyrmions组成，$q=\Pm2$)可以分离成两个双层Skyrmions(由$q=\Pm1$组成的单层Skyrmions)。我们的结果可能对设计基于受挫多层磁体的天电子器件是有用的。
We report the current-driven dynamics of frustrated skyrmions in an antiferromagnetically exchange coupled bilayer system, where the bilayer skyrmion consists of two monolayer skyrmions with opposite skyrmion numbers $Q$. We show that the in-plane current-driven bilayer skyrmion moves in a straight path, while the out-of-plane current-driven bilayer skyrmion moves in a circular path. It is found that the in-plane current-driven mobility of a bilayer skyrmion is much better than the monolayer one at a large ratio of $\beta/\alpha$, where $\alpha$ and $\beta$ denote the damping parameter and non-adiabatic spin transfer torque strength, respectively. Besides, the out-of-plane current-driven mobility of a bilayer skyrmion is much better than the monolayer one when $\alpha$ is small. We also reveal that one bilayer skyrmion (consisting of monolayer skyrmions with $Q=\pm 2$) can be separated to two bilayer skyrmions (consisting of monolayer skyrmions with $Q=\pm 1$) driven by an out-of-plane current. Our results may be useful for designing skyrmionic devices based on frustrated multilayer magnets.