Fig. 4: Electronic dispersion from differentiation.
From: Fermi surface tomography
a Exemplary angular distributions of the intensity in Bi2Te3 recorded at different threshold energies. Angular map taken at 1.68 eV corresponds to the Fermi level. b Three-dimensional intensity distribution consisting of 73 layers measured with 10 meV steps. Background intensity above the Fermi level is not shown. Acquisition time ~30 min. Laser, 6 eV. T = 3 K. c Derivative of the dataset shown in b along energy axis. Top maps in b and c are the same since there is no intensity above the Fermi level.
