Higher-order topological superconductors based on weak topological insulators
Higher-order topological superconductors based on weak topological insulators
复制标题
DOI：
10.1103/physrevb.104.104510
复制
发表时间：
2021-03
影响因子：
3.7
通讯作者：
Xun-Jiang Luo;Xiaoguang Pan;Xin Liu
中科院分区：
文献类型：
--
作者：
Xun-Jiang Luo;Xiaoguang Pan;Xin Liu
高阶拓扑相在边界处具有鲁棒边界态，这可以通过其边界拓扑来解释。在这项工作中，我们考虑到超导体和磁场之间的相互作用来间隙三维弱拓扑绝缘体的表面状态，我们证明了具有螺旋或手性马约拉纳铰链模式的二阶拓扑超导体（TSC）和具有马约拉纳角模式的三阶拓扑超导体（TSC）是可以实现的。值得注意的是，我们模型中的高阶TSC可以归因于它们的某些边界，表面或铰链，它们在DIII或D对称类中自然表现为一阶TSC。相应的，这些高阶tsc可以用边界一阶拓扑不变量来表征，如曲面chen数或曲面$Z_2$拓扑不变量。我们的模型可以有效地捕捉铁基超导体的拓扑结构，并具有所需的倒带结构和超导对。
High-order topological phases host robust boundary states at the boundary of the boundary, which can be interpreted from their boundary topology. In this work, considering the interplay between superconductors and magnetic fields to gap the surface states of three-dimensional weak topological insulators, we show that second-order topological superconductors (TSCs) featuring helical or chiral Majorana hinge modes and third-order TSC featuring Majorana corner modes can be realized. Remarkably, the higher-order TSCs in our models can be attributed to their certain boundaries, surfaces, or hinges, which naturally behave as first-order TSC in DIII or D symmetry class. Correspondingly, these higher-order TSCs can be characterized by the boundary first-order topological invariants, such as surface Chern numbers or surface $Z_2$ topological invariants for surface TSCs. Our models can effectively capture the topology of iron-based superconductors with desired inverted band structures and superconducting pairings.