Electrical Detection of the Spin Polarization Due to Charge Flow in the Surface State of the Topological Insulator Bi1.5Sb0.5Te1.7Se1.3
Electrical Detection of the Spin Polarization Due to Charge Flow in the Surface State of the Topological Insulator Bi1.5Sb0.5Te1.7Se1.3
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DOI：
10.1021/nl502546c
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发表时间：
2014-11-01
期刊：
影响因子：
10.8
通讯作者：
Shiraishi, Masashi
中科院分区：
文献类型：
--
作者：
Ando, Yuichiro;Hamasaki, Takahiro;Shiraishi, Masashi
我们用全电学方法测量了三维拓扑绝缘体自旋非简并表面态中电荷流动引起的自旋极化。体绝缘拓扑绝缘体Bi1.5Sb0.5Te1.7Se1.3(BSTS)中的电荷电流通过由Ni80Fe20制成的铁磁电极注入/引出，异常的与电流方向相关的磁阻证实了自旋极化的出现，这导致了BSTS/Ni80Fe20界面的自旋相关电阻。相比之下，我们对Bi2Se_3的对照实验没有得到任何结果。这些观察结果证明了费米能级控制对于拓扑绝缘体中自旋极化的电学检测的重要性。
We detected the spin polarization due to charge flow in the spin nondegenerate surface state of a three-dimensional topological insulator by means of an all-electrical method. The charge current in the bulk-insulating topological insulator Bi1.5Sb0.5Te1.7Se1.3 (BSTS) was injected/extracted through a ferromagnetic electrode made of Ni80Fe20, and an unusual current-direction-dependent magnetoresistance gave evidence for the appearance of spin polarization, which leads to a spin-dependent resistance at the BSTS/Ni80Fe20 interface. In contrast, our control experiment on Bi2Se3 gave null result. These observations demonstrate the importance of the Fermi-level control for the electrical detection of the spin polarization in topological insulators.