Chiral spin torque at magnetic domain walls
Chiral spin torque at magnetic domain walls
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DOI：
10.1038/nnano.2013.102
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发表时间：
2013-07-01
影响因子：
38.3
通讯作者：
Parkin, Stuart
中科院分区：
文献类型：
--
作者：
Ryu, Kwang-Su;Thomas, Luc;Parkin, Stuart
自旋极化电流提供了一种操纵纳米器件磁化的强大手段，并产生自旋转移力矩，可以驱动磁畴壁沿着纳米线。在超导磁线，畴壁被发现在相反的方向上移动到预期从散装自旋转移扭矩，也在更高的速度。在这里，我们表明，这是由于两个相互交织的现象，都来自自旋轨道相互作用。通过测量磁场对垂直磁化的Co/Ni/Co三层膜中电流驱动的畴壁运动的影响，我们发现作用在每个畴壁上的内部有效磁场的方向在连续的畴壁之间交替变化。这种手性有效场产生于Co/Pt界面处的Dzyaloshinskiii-Moriya相互作用，并且与自旋霍尔电流相一致，驱动畴壁沿沿着纳米线以锁步方式运动。阐明磁膜中畴壁的操纵机制将使自旋电子器件新家族的发展成为可能。
Spin-polarized currents provide a powerful means of manipulating the magnetization of nanodevices, and give rise to spin transfer torques that can drive magnetic domain walls along nanowires. In ultrathin magnetic wires, domain walls are found to move in the opposite direction to that expected from bulk spin transfer torques, and also at much higher speeds. Here we show that this is due to two intertwined phenomena, both derived from spin-orbit interactions. By measuring the influence of magnetic fields on current-driven domain-wall motion in perpendicularly magnetized Co/Ni/Co trilayers, we find an internal effective magnetic field acting on each domain wall, the direction of which alternates between successive domain walls. This chiral effective field arises from a Dzyaloshinskii-Moriya interaction at the Co/Pt interfaces and, in concert with spin Hall currents, drives the domain walls in lock-step along the nanowire. Elucidating the mechanism for the manipulation of domain walls in ultrathin magnetic films will enable the development of new families of spintronic devices.