Two dimensional photonic quasicrystal edge states protected by second Chern number

TL;DR

This paper explores two-dimensional photonic quasicrystal lattices characterized by higher-order topological invariants, revealing protected edge states that enable higher-dimensional topological physics in photonic systems.

Contribution

It introduces a theoretical framework for 1D and 2D photonic quasicrystals characterized by the first and second Chern numbers, highlighting the existence of protected edge states.

Findings

Identification of boundary states within photonic band gaps.

Proposal for experimental realization using dielectric rods.

Demonstration of higher-dimensional topological physics in photonics.

Abstract

Topological physics in photonic systems have attracted great attentions in recent years. In this work, we theoretically study the one and two dimensional photonic quasicrystal resonator lattices characterized by the first and second Chern number, which show exotic boundary states within the photonic energy band gap. In particular, the second Chern number protected edge states has opened up new possibilities for realizing topological physics of dimensions higher than three in photonic systems, which is highly sought for. Such photonic systems can be easily experimentally realized in regular photonic crystal with dielectric rods in air, by varying the radius of the rods, so we propose experiments realizing our predictions.