Topological states in the super-SSH model

The topological edge state distributes along the edge of a topological insulator which has advantages in prohibiting radiation and reflection in the evolution dynamics because of the topological protection property. The Su-Schrieffer-Heeger (SSH) model provides the simplest lattice configuration that supports topological edge states. Here, we investigate the properties of an extended SSH model - super-SSH model - with three sites in a unit cell for one-dimensional case and nine sites in a unit cell for two-dimensional case. Theoretical analysis and numerical simulation demonstrate that topological edge states and topological defect states are supported in the super-SSH model. This work extends the form of SSH model and may serve as a novel platform for developing photonic techniques based on topological phase transition.