论文标题
通过拓扑绝缘器异质结构中的接口工程控制自旋轨道扭矩
Control of spin-orbit torques by interface engineering in topological insulator heterostructures
论文作者
论文摘要
（bi $ _ {1-x} $ sb $ _x $）$ _ 2 $ _ 2 $ te $ _3 $拓扑绝缘器（TIS），由于它们的较大的充电转换效率以及随后的旋转轨道摩尔克斯（SOTS），可以用来操纵Ferromagnet（Feromagnet（Feromagnet）（FM）。然而，扭矩的起源仍然难以捉摸，而杂交状态的含义和Ti/FM接口处的强材料相互混合基本上没有探索。通过结合界面化学分析和自旋转移铁磁共振（ST-FMR）测量，我们证明了混合在SOT的产生中起着至关重要的作用。通过插入合适的正常金属垫片，材料相互混合的降低，界面处的Ti特性在很大程度上得到了改善，从而导致SOT的性质差异很大。观察到了磁场状扭矩的急剧增强，相反和超过了磁场扭矩，这可以归因于Rashba-Split表面带中的非平衡自旋密度以及抑制自旋记忆损失。
(Bi$_{1-x}$Sb$_x$)$_2$Te$_3$ topological insulators (TIs) are gathering increasing attention owing to their large charge-to-spin conversion efficiency and the ensuing spin-orbit torques (SOTs) that can be used to manipulate the magnetization of a ferromagnet (FM). The origin of the torques, however, remains elusive, while the implications of hybridized states and the strong material intermixing at the TI/FM interface are essentially unexplored. By combining interface chemical analysis and spin-transfer ferromagnetic resonance (ST-FMR) measurements, we demonstrate that intermixing plays a critical role in the generation of SOTs. By inserting a suitable normal metal spacer, material intermixing is reduced and the TI properties at the interface are largely improved, resulting in strong variations in the nature of the SOTs. A dramatic enhancement of a field-like torque, opposing and surpassing the Oersted-field torque, is observed, which can be attributed to the non-equilibrium spin density in Rashba-split surface bands and to the suppression of spin memory loss.
