Topologically nontrivial bismuth(111) thin films.
Topologically nontrivial bismuth(111) thin films.
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拓扑非平凡的铋(111)薄膜
DOI：
10.1038/srep21326
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发表时间：
2016-02-18
影响因子：
4.6
通讯作者：
Jia JF
中科院分区：
文献类型：
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作者：
Yao MY;Zhu F;Han CQ;Guan DD;Liu C;Qian D;Jia JF
利用高分辨率角分辨光谱学（ARPES）研究了生长在Bi2Te3（111）衬底上的三维Bi（111）薄膜的拓扑性质。与体Bi不同的是，除了30 nm薄膜上的两个众所周知的表面带外，我们还在“缺失方程”点附近发现了另一个表面带。利用这种新的表面能带，可以通过Bi(111)/Bi2Te3薄膜中的表面态连接体价带和体导带。我们的能带映射揭示了表面能带的费米交叉数为奇数，这为一定厚度的Bi(111)/Bi2Te3薄膜在三维拓扑上具有非平凡性提供了新的实验证据。
Using high-resolution angle-resolved photoemission spectroscopy (ARPES), the topological property of the three-dimensional Bi(111) films grown on the Bi2Te3(111) substrate were studied. Very different from the bulk Bi, we found another surface band near the "Equation missing" point besides the two well-known surface bands on the 30 nm films. With this new surface band, the bulk valence band and the bulk conduction band can be connected by the surface states in the Bi(111)/Bi2Te3 films. Our band mapping revealed odd number of Fermi crossings of the surface bands, which provided new experimental evidences that Bi(111)/Bi2Te3 films of a certain thickness can be topologically nontrivial in three dimension.