Figure 1: Fermi surfaces and the Dirac cones.
From: Multiple Dirac cones at the surface of the topological metal LaBi
(a) Crystal structure of LaBi possessing simple NaCl type structure. (b) Bulk Brillouin zone of LaBi and the projection of the (001) surface Brillouin zone. In bulk, the band inversion occurs at the X point. Two bulk X points are projected to the surface 
point while one bulk Γ point is projected to the surface 
point. Thus, two Dirac-cone-like surface states are expected to exist at 
and one Dirac-cone-like surface state at 
, as is illustrated in graph (b) showing the surface Brillouin zone. (c) Calculated (001) surface band structure of LaBi along the 
−
−
line providing the existence of a Dirac point (DP) at 
and two Dirac nodes at 
. (d) Calculated surface band structure along the 
−
−
line. (c,d) The colour bar from red to grey represents high to low surface contribution. (e) ARPES surface spectra measured along 
−
−
direction with 83 eV photon energy. (f) ARPES surface spectra measured along 
−
−
direction with 110 eV photon energy. (e,f) The colour bar from blue to white represents high to low intensity (a.u.).
