Determining the detailed spin texture of topological surface states is important when one wants to apply topological insulators in spintronic devices. In principle, the in‐plane spin component of the surface states can be measured by a method analogous to the so‐called Meservey–Tedrow technique. Herein, it is suggested that the out‐of‐plane spin component can be determined by spin Hall effect tunneling spectroscopy. An analytical formula that allows to extract the out‐of‐plane spin component from spin Hall effect tunneling spectra is derived. The formula is tested using realistic tight‐binding models of Bi₂Se₃ and Sb₂Te₃. It is demonstrated that the extracted out‐of‐plane spin polarization is in very good agreement with the actual out‐of‐plane spin polarization.

中文翻译：

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自旋霍尔效应隧穿光谱法测定拓扑表面态的平面外自旋极化

当要在自旋电子器件中应用拓扑绝缘体时，确定拓扑表面状态的详细自旋纹理非常重要。原则上，可以通过类似于所谓的Meservey-Tedrow技术的方法来测量表面状态的面内自旋分量。在此，建议可以通过自旋霍尔效应隧穿光谱法确定平面外自旋分量。推导出一个解析公式，该公式可以从自旋霍尔效应隧穿光谱中提取平面外自旋分量。该公式使用Bi ₂ Se ₃和Sb ₂ Te _3的逼真的紧密结合模型进行了测试。结果表明，提取的面外自旋极化与实际面外自旋极化非常吻合。