Manipulation of topological edge and corner states in photonic Kagome crystals through different combinations

Topological edge and corner states of valley photonic crystals with zipper-like boundary conditions

“…By changing the distance between the dielectric pillars and the center of the unit cell, the Wannier centers in the photonic crystal are affected, thereby adjusting the degree of inter-cell/intra-cell coupling in the structure to achieve a topological phase transition, open a band gap, and also realize valley photonic crystals. [30,32] This paper uses the eigenfrequency analysis of COMSOL Multiphysics and the finite element method to numerically solve for the dispersion relations. We break the mirror symmetry of the C 3v symmetric valley photonic crystals by rotating the unit cell structure of the C 3v symmetric valley photonic crystals to transform it into a C 3 symmetric photonic crystal unit cell structure, which can also realize valley photonic crystals.…”

“…At the 60 • corner, the sign of the valley Chern number flips, and TCSs appear. [31,32] In addition, most other studies on TCSs using hexagonal lattice realizations have only examined corner structures of PCs constituted by zigzag-type boundary bends, [33,34] and more shapes of topological corner structures have not been widely studied. Further exploration of the changes and impacts of different edge domain walls and corner structures on TCSs, understanding the information conveyed by TCSs characteristic frequencies, is of significant investigational importance and greatly aids in constructing new devices based on TCSs.…”