Fig. 5: Fermi surface, electronic dispersions and quasi two-dimensional Dirac cone in BaGa₂.

a Schematic drawing of the 3D Brillouin zone with high symmetry points marked by red points and its projected surface Brillouin zone to (001) surface. b Measured Fermi surface with corresponding Brillouin zone. c Measured electronic dispersion along \(\overline{{{\Gamma }}}-\overline{{\rm{K}}}-\overline{{\rm{M}}}-\overline{{\rm{\Gamma }}}\) direction. d Calculated bulk and surface electronic dispersion of the Ba&Ga-terminated BaGa₂ (001) surface with different k_z along \(\overline{{\rm{\Gamma }}}-\overline{{\rm{K}}}-\overline{{\rm{M}}}-\overline{{\rm{\Gamma }}}\) direction. e Schematic drawing shows the slices (purple plane) which cut through the Dirac cones at different k_y. f Electronic dispersions cut through the Dirac cones at corresponding k_y and corresponding electronic dispersions in the upper panel after normalization by integrating energy distribution curve (EDC). g k_z dependence of electronic dispersions cut through the Dirac point and corresponding electronic dispersions in the upper panel after normalization by integrating EDC. The unit of k_z is 2π/c.