It is recognized that for a certain class of periodic photonic crystals, conical dispersion can be related to a zero-refractive index. It is not obvious whether such a notion can be extended to a noncrystalline system. We show that certain photonic quasicrystalline approximants have conical dispersions at the zone center with a triply degenerate state at the Dirac frequency, which is the necessary condition to qualify as a zero-refractive-index medium. The states in the conical dispersions are extended and have a nearly constant phase. Experimental characterizations of finite-sized samples show evidence that the photonic quasicrystals do behave as a near zero-refractive-index material around the Dirac frequency.
Null option (theme 11)
American Physical Society
Unspecified
Physical Review Letters
Scientific Computing

Dong, J, Chang, M, Huang, X, Hang, Z, Zhong, Z, Chen, W, … Huang, Z. (2015). Conical Dispersion and Effective Zero Refractive Index in Photonic Quasicrystals. Physical Review Letters, 114(16).