Interface-driven chiral magnetism and current-driven domain walls in insulating magnetic garnets
Interface-driven chiral magnetism and current-driven domain walls in insulating magnetic garnets
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DOI：
10.1038/s41565-019-0421-2
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发表时间：
2019-06-01
影响因子：
38.3
通讯作者：
Beach, Geoffrey S. D.
中科院分区：
文献类型：
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作者：
Avci, Can Onur;Rosenberg, Ethan;Beach, Geoffrey S. D.
磁性氧化物表现出丰富的基础物理（1-4）和技术上理想的自旋存储器，逻辑和信号传输（5-7）的属性。最近，通过使用诸如铂的邻近重金属层，已经在绝缘磁性氧化物中实现了自旋-轨道诱导的自旋输运现象（8-10）。在它们的金属铁磁体对应物中，这样的界面也引起Dzyaloshinskiii-Moriya相互作用（11-13），其可以通过有效的电流驱动动力学稳定纯手性畴壁和skyrmion。然而，在中心对称氧化物的手性磁性尚未被观察到。在这里，我们发现手征磁性，允许纯自旋电流驱动的畴壁运动中最普遍的一类磁性氧化物，亚铁磁性铁石榴石。我们发现，外延稀土铁石榴石薄膜具有垂直磁各向异性表现出纯手性尼尔域壁，可以推进速度超过800 m s（-1）的自旋电流从相邻的铂层。我们发现，尽管相对较小的界面Dzyaloshinskiii-Moriya相互作用，非常高的速度可以达到由于反铁磁自旋动力学与亚铁磁秩序。
Magnetic oxides exhibit rich fundamental physics(1-4) and technologically desirable properties for spin-based memory, logic and signal transmission(5-7). Recently, spin-orbit-induced spin transport phenomena have been realized in insulating magnetic oxides by using proximate heavy metal layers such as platinum(8-10). In their metallic ferromagnet counterparts, such interfaces also give rise to a Dzyaloshinskii-Moriya interaction(11-13) that can stabilize homochiral domain walls and skyrmions with efficient current-driven dynamics. However, chiral magnetism in centrosymmetric oxides has not yet been observed. Here we discover chiral magnetism that allows for pure spin-current-driven domain wall motion in the most ubiquitous class of magnetic oxides, ferrimagnetic iron garnets. We show that epitaxial rare-earth iron garnet films with perpendicular magnetic anisotropy exhibit homochiral Neel domain walls that can be propelled faster than 800 m s(-1) by spin current from an adjacent platinum layer. We find that, despite the relatively small interfacial Dzyaloshinskii-Moriya interaction, very high velocities can be attained due to the antiferromagnetic spin dynamics associated with ferrimagnetic order.