Interfacial spin-orbit torque without bulk spin-orbit coupling
Interfacial spin-orbit torque without bulk spin-orbit coupling
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DOI：
10.1103/physrevb.93.180402
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发表时间：
2016-05-04
影响因子：
3.7
通讯作者：
Sun, Nian X.
中科院分区：
文献类型：
--
作者：
Emori, Satoru;Nan, Tianxiang;Sun, Nian X.
在存在自旋-轨道耦合的情况下，电流可以产生自旋积累，从而对附近的磁化作用施加扭矩。我们证明，即使在没有具有强整体自旋-轨道耦合的材料的情况下，扭矩也可以完全由界面自旋-轨道耦合产生，即金属/绝缘体界面的Rashba-Eldestein效应。在夹在弱自旋轨道金属(Ti)和绝缘体(Al_2O_3)之间的软磁NiFe中，这个力矩看起来像是一个有效场，它明显大于Oersted场，并通过在NiFe和Al_2O_3之间插入额外的一层来进行定性的修改。我们的发现指出了通过设计界面电偶极子来调节自旋轨道扭矩的非传统途径。
An electric current in the presence of spin-orbit coupling can generate a spin accumulation that exerts torques on a nearby magnetization. We demonstrate that, even in the absence of materials with strong bulk spin-orbit coupling, a torque can arise solely due to interfacial spin-orbit coupling, namely, Rashba-Eldestein effects at metal/insulator interfaces. In magnetically soft NiFe sandwiched between a weak spin-orbit metal (Ti) and insulator (Al2O3), this torque appears as an effective field, which is significantly larger than the Oersted field and qualitatively modified by inserting an additional layer between NiFe and Al2O3. Our findings point to unconventional routes for tuning spin-orbit torques by engineering interfacial electric dipoles.