Enhanced Spin-Orbit Torque via Modulation of Spin Current Absorption.
Enhanced Spin-Orbit Torque via Modulation of Spin Current Absorption.
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DOI：
10.1103/physrevlett.117.217206
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发表时间：
2016-10
影响因子：
8.6
通讯作者：
X. Qiu;W. Legrand;P. He;Yang Wu;Jiawei Yu;R. Ramaswamy;A. Manchon;Hyunsoo Yang
中科院分区：
文献类型：
--
作者：
X. Qiu;W. Legrand;P. He;Yang Wu;Jiawei Yu;R. Ramaswamy;A. Manchon;Hyunsoo Yang
相邻重金属（HM）施加到铁磁体（FM）的自旋轨道力矩（SOT）的大小强烈地依赖于FM中吸收的自旋电流的量。我们利用在Ru界面处的大的自旋吸收来操纵HM/FM/Ru多层膜中的SOT。虽然FM厚度小于其1.2 nm的自旋退相长度，但顶部Ru层大大增强了FM层对自旋电流的吸收，并显著增强了作用于FM的SOT的强度。由铁磁共振引起的自旋抽运实验支持我们的结论，即所观察到的SOT效率的增加可以归因于自旋电流吸收的增强。一个理论模型，同时考虑反射和透射混频电导在两个界面的FM开发来解释的结果。
The magnitude of spin-orbit torque (SOT), exerted to a ferromagnet (FM) from an adjacent heavy metal (HM), strongly depends on the amount of spin current absorbed in the FM. We exploit the large spin absorption at the Ru interface to manipulate the SOTs in HM/FM/Ru multilayers. While the FM thickness is smaller than its spin dephasing length of 1.2 nm, the top Ru layer largely boosts the absorption of spin currents into the FM layer and substantially enhances the strength of SOT acting on the FM. Spin-pumping experiments induced by ferromagnetic resonance support our conclusions that the observed increase in the SOT efficiency can be attributed to an enhancement of the spin-current absorption. A theoretical model that considers both reflected and transmitted mixing conductances at the two interfaces of FM is developed to explain the results.