Hybrid topological photonic crystals

• Published in: Nature communications Vol. 14; no. 1; pp. 4457 - 9
• Main Authors: Wang, Yanan, Wang, Hai-Xiao, Liang, Li, Zhu, Weiwei, Fan, Longzhen, Lin, Zhi-Kang, Li, Feifei, Zhang, Xiao, Luan, Pi-Gang, Poo, Yin, Jiang, Jian-Hua, Guo, Guang-Yu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25.07.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1019/1022; 639/624/399/1022; 639/766/1130/2799; Beam splitters; Channels; Coexistence; Crystals; Data processing; Humanities and Social Sciences; Information processing; multidisciplinary; Multiplexing; Photonic band gaps; Photonic crystals; Photons; Quantum phenomena; Science; Science (multidisciplinary); Topological insulators; Topology; Valleys
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-40172-6

Topologically protected photonic edge states offer unprecedented robust propagation of photons that are promising for waveguiding, lasing, and quantum information processing. Here, we report on the discovery of a class of hybrid topological photonic crystals that host simultaneously quantum anomalous Hall and valley Hall phases in different photonic band gaps. The underlying hybrid topology manifests itself in the edge channels as the coexistence of the dual-band chiral edge states and unbalanced valley Hall edge states. We experimentally realize the hybrid topological photonic crystal, unveil its unique topological transitions, and verify its unconventional dual-band gap topological edge states using pump-probe techniques. Furthermore, we demonstrate that the dual-band photonic topological edge channels can serve as frequency-multiplexing devices that function as both beam splitters and combiners. Our study unveils hybrid topological insulators as an exotic topological state of photons as well as a promising route toward future applications in topological photonics. Owing to the nonequilibrium nature, photonic topological phenomena can involve multiple band gaps. Here the authors report on the discovery of a class of hybrid topological photonic crystals that host quantum anomalous Hall and valley Hall phases simultaneously.