Higher‐Order Topological States in Surface‐Wave Photonic Crystals
Higher‐Order Topological States in Surface‐Wave Photonic Crystals
Photonic topological states have revolutionized our understanding on the propagation and scattering of light. Recent discovery of higher-order photonic topological insulators opens an emergent horizon for zero-dimensional topological corner states. However, the previous realizations of higher-order photonic topological insulators suffer from either a limited operational frequency range due to the …