Full utilization of semi-Dirac cones in photonics

Yasa U. G., Turduev M., Giden I. H., KURT H.

Physical Review B, vol.97, no.19, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 97 Issue: 19
  • Publication Date: 2018
  • Doi Number: 10.1103/physrevb.97.195131
  • Journal Name: Physical Review B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • TED University Affiliated: Yes


© 2018 American Physical Society.In this study, realization and applications of anisotropic zero-refractive-index materials are proposed by exposing the unit cells of photonic crystals that exhibit Dirac-like cone dispersion to rotational symmetry reduction. Accidental degeneracy of two Bloch modes in the Brillouin zone center of two-dimensional C2-symmetric photonic crystals gives rise to the semi-Dirac cone dispersion. The proposed C2-symmetric photonic crystals behave as epsilon-and-mu-near-zero materials (eff≈0, μeff≈0) along one propagation direction, but behave as epsilon-near-zero material (eff≈0, μeff≠0) for the perpendicular direction at semi-Dirac frequency. By extracting the effective medium parameters of the proposed C4- and C2-symmetric periodic media that exhibit Dirac-like and semi-Dirac cone dispersions, intrinsic differences between isotropic and anisotropic materials are investigated. Furthermore, advantages of utilizing semi-Dirac cone materials instead of Dirac-like cone materials in photonic applications are demonstrated in both frequency and time domains. By using anisotropic transmission behavior of the semi-Dirac materials, photonic application concepts such as beam deflectors, beam splitters, and light focusing are proposed. Furthermore, to the best of our knowledge, semi-Dirac cone dispersion is also experimentally demonstrated for the first time by including negative, zero, and positive refraction states of the given material.