论文标题
二维Su-Schrieffer-Heeger模型中的拓扑状态
Topological States in Two-Dimensional Su-Schrieffer-Heeger Models
论文作者
论文摘要
我们研究了广义二维（2D）Su-Schrieffer-Heeger（SSH）模型的拓扑特性。我们表明，在布里渊区（BZ）中出现了一对狄拉克点，其中包括半金属阶段。有趣的是，这些狄拉克点的位置未固定在BZ的任何高对称点，而是通过模型参数调节。此外，两个狄拉克点的合并经历了一种新型的拓扑相变，这会导致弱拓扑绝缘子或节点线金属相。我们通过构建两个特定模型来证明这些属性，我们称它们为I型和II类型2D SSH模型。还讨论了可行的实验平台，以实现我们的模型。
We study the topological properties of the generalized two-dimensional (2D) Su-Schrieffer-Heeger (SSH) models. We show that a pair of Dirac points appear in the Brillouin zone (BZ), consisting a semimetallic phase. Interestingly, the locations of these Dirac points are not pinned to any high-symmetry points of the BZ but tunable by model parameters. Moreover, the merging of two Dirac points undergoes a novel topological phase transition, which leads to either a weak topological insulator or a nodal-line metallic phase. We demonstrate these properties by constructing two specific models, which we referred as type-I and type-II 2D SSH models. The feasible experimental platforms to realize our models are also discussed.
