Surface and edge states in topological semimetals
Surface and edge states in topological semimetals
复制标题
DOI：
10.1103/physrevb.83.075110
复制
发表时间：
2011-02-15
影响因子：
3.7
通讯作者：
Shen, Shun-Qing
中科院分区：
文献类型：
--
作者：
Chu, Rui-Lin;Shan, Wen-Yu;Shen, Shun-Qing
我们利用六带Kane模型研究了拓扑非平凡半金属。通过计算材料表面的局域态密度（LDOS），明确地证明了表面态的存在。在无应变条件下，表面态在能谱中被分为两部分，一部分位于直接带隙中，另一部分包括表面态狄拉克锥的交叉点淹没在价带中。我们还展示了单轴应变如何诱导绝缘带隙，并提高了从价带到带隙的交叉点，使系统成为一个真正的拓扑绝缘体。我们预测了薄膜拓扑半金属中螺旋边缘态和自旋霍尔效应的存在，这可以通过未来的实验来验证。发现无序显著增强了薄膜价带中的自旋霍尔效应。
We study the topologically nontrivial semimetals by means of the six-band Kane model. Existence of surface states is explicitly demonstrated by calculating the local density of states (LDOS) on the material surface. In the strain-free condition, surface states are divided into two parts in the energy spectrum, one part is in the direct gap, the other part including the crossing point of surface state Dirac cone is submerged in the valence band. We also show how uniaxial strain induces an insulating band gap and raises the crossing point from the valence band into the band gap, making the system a true topological insulator. We predict the existence of helical edge states and spin Hall effect in the thin-film topological semimetals, which could be tested by future experiments. Disorder is found to significantly enhance the spin-Hall effect in the valence band of the thin films.