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Accidental Double Dirac Cones and Robust Edge States in Topological Anisotropic Photonic Crystals
Author(s) -
Chen XiaoDong,
Deng WeiMin,
Zhao FuLi,
Dong JianWen
Publication year - 2018
Publication title -
laser and photonics reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.778
H-Index - 116
eISSN - 1863-8899
pISSN - 1863-8880
DOI - 10.1002/lpor.201800073
Subject(s) - physics , photonics , photonic crystal , isotropy , transverse plane , topology (electrical circuits) , dirac (video compression format) , anisotropy , optics , quantum mechanics , mathematics , structural engineering , combinatorics , neutrino , engineering
Dirac cones in photonic systems have many profound applications such as achieving zero‐index materials and nontrivial photonic phases. It is shown that double Dirac cones at the zone boundary can be restored by achieving accidental degeneracy between transverse electric and transverse magnetic modes in 2D photonic crystals with anisotropic permittivity. The topological band gap can be obtained by lifting nontrivial double Dirac cones, each of which is formed by two orthogonally polarized linear branches sharing the same mirror parities. Robust transport of gapless and high transmission of gapped edge states are also demonstrated in topological anisotropic photonic crystals, demonstrating that a high transmission flat‐top spectrum is observed in various working frequency regions even when the interface is no longer straight. This may pave the way to a paradigm for a bandwidth‐controllable robust waveguide in topological photonics.