title: Selection rule for Dirac-like points in two-dimensional dielectric photonic crystals.
abstract: We developed a selection rule for Dirac-like points in two-dimensional dielectric photonic crystals. The rule is derived from a perturbation theory and states that a non-zero, mode-coupling integral between the degenerate Bloch states guarantees a Dirac-like point, regardless of the type of the degeneracy. In fact, the selection rule can also be determined from the symmetry of the Bloch states even without computing the integral. Thus, the existence of Dirac-like points can be quickly and conclusively predicted for various photonic crystals independent of wave polarization, lattice structure, and composition.
authors.affiliation: Department of Physics, South China University of Technology, Guangzhou 510641, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Mei
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003460:Crystallization; D008027:Light; D008962:Models, Theoretical; D012542:Scattering, Radiation