Fig. 3: Experimentally resolved electronic structure.

a DFT + U-calculated Fermi surface contours at k_z = 0.5 with U = 2 eV for CsV₆Sb₆. b Constant energy contours at binding energy E_b = 0 measured in CsV₆Sb₆ at around 12 K by ARPES using 60 eV photons. Yellow lines denote the boundary of the projected 2D Brillouin zone. c, d, e, f, Same as a, b, but for the constant energy contour at E_b = 200 meV and E_b = 400 meV. respectively. Red dotted lines in b, d, f are guides to the eye. g The bulk band structures of CsV₆Sb₆ at different k_z ranging from 0 to 0.5 were obtained from DFT+U calculations with U = 2 eV. h Photoelectron intensity plot along the \(\bar{\varGamma }-\bar{{\rm M}}\) momentum cut (red dashed line in b), measured with 60 eV photons at T ≈ 12 K.