Fig. 1
From: Pseudo-spin–valley coupled edge states in a photonic topological insulator
Schematic of the sample configuration. a Side view of the structure. b Arrangement of two crystalline regions with the two copper plates on top and bottom removed. Lattice constant a = 1.0890 cm. c, d Unit cells of two crystals emulating the quantum spin–Hall (QSH) and quantum valley-Hall (QVH) effects. Dimensions of unit cells: H = 1.0890 cm, hc = 0.3580 cm, dc = 0.6215 cm, d0 = 0.3175 cm, h = 0.5040 cm, g = 0.0810 cm, l = 0.5020 cm. e, f Berry curvatures of the triangular lattice (valley Hall crystal) for the TE mode in the valence bands near the K and K′ points
