Gapless surface states originated from accidentally degenerate quadratic band touching in a three-dimensional tetragonal photonic crystal

Abstract

A tetragonal photonic crystal composed of high-index pillars can exhibit a frequency-isolated accidental degeneracy at a high-symmetry point in the first Brillouin zone. A photonic band gap can be formed there by introducing a geometrical anisotropy in the pillars. In this gap, gapless surface/domain-wall states emerge under a certain condition. We analyze their physical property in terms of an effective hamiltonian, and a good agreement between the effective theory and numerical calculation is obtained.

6 pages, 5 figures

References in corpus (4)

• Classification of topological insulators and superconductors in three spatial dimensions
• Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials
• Scheme to Achieve Silicon Topological Photonics
• Topological Acoustics

Cited by in corpus (2)

• Topological edge states in all-dielectric square-lattice arrays of bianisotropic microwave resonators
• Theoretical description of interface states in a tetragonal lattice of bianisotropic resonators