Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic
Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic
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灰砷表面拓扑纠缠的拉什巴分裂肖克利态
DOI：
10.1103/physrevlett.118.046802
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发表时间：
2017
影响因子：
8.6
通讯作者：
Shin S.
中科院分区：
文献类型：
--
作者：
Zhang Peng;Ma J-Z;Ishida Y.;Zhao L-X;Xu Q-N;Lv B-Q;Yaji K.;Chen G-F;Weng H-M;Dai X.;Fang Z.;Chen X-Q;Fu L.;Qian T.;Ding H.;Shin S.
利用角分辨光电子能谱（ARPES）在灰砷（111）面上发现了一对自旋极化表面带。在被占据的一侧，这对电子类似于在贵金属表面上观察到的典型的近自由电子肖克利态。然而，泵浦-探测ARPES表明，自旋极化对穿过体带隙，并且对的交叉是拓扑不可避免的。第一性原理计算很好地再现了能带和它们的非平凡拓扑结构;计算还支持表面态是Shockley型的，因为它们是由晶场引起的能带反转引起的。这些结果为在As（111）上实现拓扑Shockley态提供了有力的证据。
We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair atis topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).