Extended Data Fig. 3: Pyrochlore band features in CaNi2.
From: Three-dimensional flat bands in pyrochlore metal CaNi2
(a-c) Dispersion of CaNi2 around the Brillouin zone center Γ. The spectrum in (a) (obtained from the photon energy-dependent ARPES measurements) was normalized using the intensity of the flat band at −0.58 eV. We summed two spectra collected by photons with linear vertical and linear horizontal polarization to minimize matrix element effects. The black arrow marks the quadratic band touching points (QBT) expected from the model pyrochlore tight-binding calculation. (d) ARPES spectrum obtained with 175 eV photons with linear vertical polarization. The black arrows indicate the Dirac nodes at W. (e) Second derivative plot of (d). (f) The DFT band dispersion of CaNi2 to be compared with (d),(e). (g) EDC plots of CaNi2 showing the FB1, FB2, and FB3 dispersions (red, blue, and green circles, respectively). (h) The energy-momentum dispersion along the high symmetry directions. The dispersions along different high symmetry directions were obtained from the following measurements: the Γ-K-X dispersion from the kz = 0 Fermi surface obtained using 217 eV photons, the Γ-L dispersion from the photon-energy dependence measurements from 135 eV to 175 eV photons, and the L-U-W-L dispersion from the kz = π/c Fermi surface obtained using 175 eV photons.
