Higher-order topological phases in tunable C3 symmetric photonic crystals

• DOI: 10.1364/prj.433188
• Publication Date: 2021-07-20T20:30:10Z
• Authors: Hai-Xiao Wang; Li Liang; Bin Jiang; Junhui Hu; Xiancong Lu; Jian-Hua Jiang
• Keywords: Topological insulator

We demonstrate that multiple higher-order topological transitions can be triggered via the continuous change of geometry in kagome photonic crystals composed three dielectric rods. By tuning a single parameter, corner and edge states emerge or disappear with transitions. Two distinct insulator phases normal phase are revealed. Their indices obtained from symmetry representations. A analog fractional charge is introduced to distinguish two phases. Our predictions readily realized verified configurable crystals.