论文标题
高阶拓扑阶段的网络模型
Network model for higher-order topological phases
论文作者
论文摘要
我们引入了一个实现高阶拓扑阶段（HOTP）的二维网络模型。我们发现，在HOTP中，系统的整体和边界被覆盖，总共16个角状态受到四倍旋转，相位旋转和颗粒 - 孔对称性的组合的保护。此外，该模型在最大耦合点上表现出强大的拓扑阶段。这种行为与常规网络模型相反，这一点在这一点上是无间隙的。通过引入适当的拓扑不变，我们展示了点组对称性如何保护网络中的拓扑阶段。我们的工作为实现网络模型的替代实验平台实现HOTP提供了基础。
We introduce a two-dimensional network model that realizes a higher-order topological phase (HOTP). We find that in the HOTP the bulk and boundaries of the system are gapped, and a total of 16 corner states are protected by the combination of a four-fold rotation, a phase-rotation, and a particle-hole symmetry. In addition, the model exhibits a strong topological phase at a point of maximal coupling. This behavior is in opposition to conventional network models, which are gapless at this point. By introducing the appropriate topological invariants, we show how a point group symmetry can protect a topological phase in a network. Our work provides the basis for the realization of HOTP in alternative experimental platforms implementing the network model.
