Fig. 6

Surface-projected photon energy dependence in FeSe. In (a), we build a 20 layer slab tight-binding model from the bulk model in Fig. 2. We calculate the ARPES intensity along the ΓM direction, at several photon energies; the results are summarized by a cut at constant binding energy of E_B = 25 meV in panel (b). Spectra at each photon energy have been renormalized to their maximum intensity. In panels (c–e), spectra at select photon energies are plotted, chosen to correspond to the same k_z = 0 Å⁻¹ point in successive Brillouin zones to enable direct comparison. Photon energy dependence of the measured linewidth is observed due to effective k_z integration