Topological States in Two-Dimensional Su-Schrieffer-Heeger Models
Chang-An Li
Abstract
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.
Topics & Concepts
Brillouin zoneDirac (video compression format)Topological insulatorTopology (electrical circuits)PhysicsSymmetry (geometry)Phase (matter)Type (biology)Phase transitionCondensed matter physicsQuantum mechanicsMathematicsGeometryCombinatoricsBiologyNeutrinoEcologyTopological Materials and PhenomenaQuantum Mechanics and Non-Hermitian PhysicsQuantum many-body systems