Topological valley crystals in a photonic Su–Schrieffer–Heeger (SSH) variant

Progress on two-dimensional materials has shown that valleys, as energy extrema in a hexagonal first Brillouin zone, provides new degree of freedom for information manipulation. Then valley Hall topological insulators supporting such-polarized edge states boundaries were set up accordingly. In this paper, photonic crystal composed six tunable dielectric triangular pillars unit cells is proposed the sense deformed Su-Schrieffer-Heeger (SSH) model. We reveal vortex nature and establish selection rules polarized states. Based topology, rhombus-shaped beam splitter waveguide designed to verify valley-chirality above. Our numerical results entail topologically protected still maintain robust transmission at sharp corners, henceforth providing feasible idea devices THz regime.