Fig. 1

a Schematics of the 2D GPCs. b The Brillouin zones. c Band structure of the lattice based on the rhombic primitive unit cell indicated with green dashed lines, the insets plot the eigen electric field distributions of the Dirac point. d Band structure of the lattice based on the hexagonal unit cell, the insets plot the eigen electric field distributions of the double Dirac point. The other parameters are set as μ_c1 = 0.3 eV, μ_c2 = 0.6 eV, τ = 1 ps, the lattice constant a = 40 nm