论文标题
从su-schrieffer-heeger堆叠出来的高阶拓扑阶段
Higher-order topological phases emerging from the Su-Schrieffer-Heeger stacking
论文作者
论文摘要
在这项工作中，我们开发了一种系统的方法，用于为二维（2D）高阶拓扑阶段构建和分类，并具有零零能量状态（CZESS）。我们的方法基于在一系列2D系统中直接构建CZESS的分析解决方案，该系统沿两个正交方向堆叠了1D扩展Su-Schrieffer-Heeger（SSH）模型，这是原始SSH模型的两个副本。令人着迷的是，我们的方法不仅为著名的Benalcazar-Bernevig-Hughes和2D SSH模型提供了新型模型，而且我们将其引用了交叉的2D SSH模型。尽管这三个模型表现出完全不同的散装拓扑结构，但我们发现Czess可以普遍地以1D边缘状态的边缘绕组数来表征，这归因于其统一的Hamiltonian构造形式和边缘拓扑。值得注意的是，我们获得CZESS的原则很容易被推广到任意维度和超导系统。因此，我们的工作为高阶拓扑阶段的理论理解提供了新的启示，并为寻找高阶拓扑绝缘子和超导体铺平了道路。
In this work, we develop a systematical approach of constructing and classifying the model Hamiltonians for two-dimensional (2D) higher-order topological phase with corner zero energy states (CZESs). Our approach is based on the direct construction of analytical solution of the CZESs in a series of 2D systems that stack the 1D extended Su-Schrieffer-Heeger (SSH) model, two copies of the original SSH model, along two orthogonal directions. Fascinatingly, our approach not only gives the celebrated Benalcazar-Bernevig-Hughes and 2D SSH models but also reveals a novel model and we refer it to crossed 2D SSH model. Although these three models exhibit completely different bulk topology, we find that the CZESs can be universally characterized by edge winding number for 1D edge states, attributing to their unified Hamiltonian construction form and edge topology. Remarkably, our principle of obtaining CZESs can be readily generalized to arbitrary dimension and superconducting systems. Thus, our work sheds new light on the theoretical understanding of the higher-order topological phase and paves the way to looking for higher-order topological insulators and superconductors.
