Direct mapping of the spin-filtered surface bands of a three-dimensional quantum spin Hall insulator
Direct mapping of the spin-filtered surface bands of a three-dimensional quantum spin Hall insulator
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DOI：
10.1103/physrevb.81.041309
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发表时间：
2010-01-01
影响因子：
3.7
通讯作者：
Matsuda, Iwao
中科院分区：
文献类型：
--
作者：
Nishide, Akinori;Taskin, Alexey A.;Matsuda, Iwao
利用自旋极化角分辨光电子能谱（spin-polarizedangle-resolvedphotoemission spectroscopy，SPR）技术研究了三维量子自旋霍尔绝缘体Bi_（1-x）Sb_x（x=0.12-0.13）的自旋极化能带结构.在（111）表面布里渊区的两个时间反演不变点（Gamma）和（M）之间，发现一个自旋上带（Sigma（1）'带）只穿过费米能级一次，为强拓扑绝缘体相提供了明确的证据。通过对自旋极化带色散的观测，确定了“镜像手征”为-1，这与基于第一性原理计算的理论预测一致。
Spin-polarized band structure of the three-dimensional quantum spin Hall insulator Bi1-xSbx (x=0.12-0.13) was fully elucidated by spin-polarized angle-resolved photoemission spectroscopy using a high-yield spin polarimeter equipped with a high-resolution electron spectrometer. Between the two time-reversal-invariant points, (Gamma) over bar and (M) over bar of the (111) surface Brillouin zone, a spin-up band (Sigma(1)' band) was found to cross the Fermi energy only once, providing unambiguous evidence for the strong topological insulator phase. The observed spin-polarized band dispersions determine the "mirror chirality" to be -1, which agrees with the theoretical prediction based on first-principles calculations.