Transfer matrix approach for topological edge states

The authors present here a way to understand topological properties of periodic systems using the transfer matrix approach. This technique simplifies the connection between bulk properties and edge states, offering a clear proof of the Zak phase bulk-edge correspondence in one-dimensional systems. The authors use Su-Schrieffer-Heeger chains and more complicated dimerized photonic crystals to showcase this method, where it proves to be versatile in analyzing topological invariants and provides valuable insights into topological edge states.