Orbit- and atom-resolved spin textures of intrinsic, extrinsic, and hybridized Dirac cone states
Orbit- and atom-resolved spin textures of intrinsic, extrinsic, and hybridized Dirac cone states
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DOI：
10.1103/physrevb.89.155116
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发表时间：
2014-03
影响因子：
3.7
通讯作者：
L. Miao;Zhengfei Wang;M. Yao;F. Zhu;J. Dil;C. Gao;Canhua Liu;Feng Liu;D. Qian;J. Jia
中科院分区：
文献类型：
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作者：
L. Miao;Zhengfei Wang;M. Yao;F. Zhu;J. Dil;C. Gao;Canhua Liu;Feng Liu;D. Qian;J. Jia
结合第一性原理计算和自旋和角度分辨光电子能谱测量，我们确定了Bi（111）双层的二维拓扑绝缘体（TI）和三维TI B或Bi 2 Te 3界面系统中三种不同Dirac锥态的螺旋自旋织构.发现Bi_2Te_3或Bi_2Te_3表面态的本征狄拉克锥、由Rashba效应引起的Bi双层膜的非本征狄拉克锥以及前两个表面态之间的杂化狄拉克锥的自旋织构是相同的。进一步的轨道和原子分辨分析表明，s和p（z）轨道具有顺时针（逆时针）自旋旋转，与上（下）狄拉克锥的等能轮廓相切，而p（x）和p（y）轨道具有径向自旋分量。狄拉克锥态可能位于不同的原子层上，但具有相同的自旋纹理。我们的研究结果表明，狄拉克锥态的独特自旋织构是自旋轨道耦合的一个标志性性质，与拓扑结构无关。
Combining first-principles calculations and spin-and angle-resolved photoemission spectroscopy measurements, we identify the helical spin textures for three different Dirac cone states in the interfaced systems of a two-dimensional (2D) topological insulator (TI) of a Bi(111) bilayer and a three-dimensional (3D) TI B or Bi2Te3. The spin texture is found to be the same for the intrinsic Dirac cone of Bi2Te3 or Bi2Te3 surface states, the extrinsic Dirac cone of Bi bilayer induced by the Rashba effect, and the hybridized Dirac cone between the former two states. Further orbit-and atom-resolved analysis shows that s and p(z) orbits have a clockwise (counterclockwise) spin rotation tangent to the iso-energy contour of the upper (lower) Dirac cone, while p(x) and p(y) orbits have radial spin components. The Dirac cone states may reside on different atomic layers, but have the same spin texture. Our results suggest that the unique spin texture of Dirac cone states is a signature property of spin-orbit coupling, independent of topology.