论文标题
来自扩展拓扑带归化的非常规拓扑绝缘子
Unconventional Topological Insulators from Extended Topological Band Degeneracies
论文作者
论文摘要
实现拓扑绝缘体的一般而美丽的画面是，狄拉克模型的质量术语具有鼻表面包裹一个狄拉克点。我们表明，基于狄拉克点的几何图像可以推广到具有非平凡拓扑的扩展带退化。由于非客气的拓扑指控迫使要成对创建或歼灭的扩展带退化，当质量的淋巴结表面包裹着一种扩展带退化时，因此所产生的间隙阶段必须在拓扑上是非平凡的，因为它不能绝生地变形为拓扑性的跨性幻想原子原子原子原料，而无需关闭能量gap。我们使用带有非平凡$ z_ {2} $单极电荷的节点线以三个维度来说明物理。值得注意的是，由于扩展带退化的包装表面是多种多样的，因此我们发现这种概括可以带来具有极为规范的边界状态模式的拓扑绝缘子。
A general and beautiful picture for the realization of topological insulators is that the mass term of the Dirac model has a nodal surface wrapping one Dirac point. We show that this geometric picture based on Dirac points can be generalized to extended band degeneracies with nontrivial topological charges. As the nontrivial topological charges force the extended band degeneracies to be created or annihilated in pairs, when the nodal surface of mass wraps one such extended band degeneracy, the resulting gapped phase must be topologically nontrivial since it cannot adiabatically be deformed into a topologically trivial atomic insulator without closing the energy gap. We use nodal lines carrying a nontrivial $Z_{2}$ monopole charge in three dimensions to illustrate the physics. Notably, because the wrapping surfaces for an extended band degeneracy are diverse, we find that this generalization can bring topological insulators with unconventional pattern of boundary states.
