论文标题
SNSE/EUS和SNTE/CATE界面的拓扑特性
Topological Properties of SnSe/EuS and SnTe/CaTe Interfaces
论文作者
论文摘要
我们使用密度功能理论计算分别研究具有磁性绝缘体EUS和非磁性绝缘体CATE的拓扑结晶绝缘子SNSE和SNTE的外延（111）接口的电子结构。我们考虑了带有真空区域的界面平板模型和无真空的周期异质结构。我们发现，由于磁接近效应，在SNSE/EUS界面处出现了$γ$点的21 MEV和M点的9 MeV的间隙，这会破坏时间反向对称性。 $γ$的表面状态在费米水平以下移动88 MeV，由于界面处的频带弯曲，M的表面状态在费米水平上方移动47 MeV。相比之下，SNTE/CATE界面处的拓扑状态不受非磁性CATE的存在。
We use density functional theory calculations to study the electronic structure of epitaxial (111) interfaces of the topological crystalline insulators SnSe and SnTe with the magnetic insulator EuS and the non-magnetic insulator CaTe, respectively. We consider both interface slab models with a vacuum region and periodic heterostructures without vacuum. We find that gaps of 21 meV at the $Γ$ point and 9 meV at the M point arise in the topological state at the SnSe/EuS interface, due to the magnetic proximity effect, which breaks the time reversal symmetry. The surface state at $Γ$ is shifted below the Fermi level by 88 meV and the surface state at M is shifted above the Fermi level by 47 meV, owing to band bending at the interface. By comparison, the topological state at the interface of SnTe/CaTe is unperturbed by the presence of non-magnetic CaTe.
