Photoemission from the (001) surface of 1T-TiSe2: Comparison of calculation with experiment

Abstract

Normal-emission photoemission spectra from the (001) surface of 1T-titanium diselenide have been calculated and compared to experimental energy-distribution curves recorded for various photon energies in the range from 12 to 28 eV. The theory is based on a single-particle one-step model for the emission process. The initial state of the photoelectron is described by means of an empirical tight-binding method, the surface being included via a Green’s-function formalism, while a low-energy electron-diffraction scheme is used for the characterization of the final state. Dipole matrix elements are computed numerically. In comparison to the experimental data, the variation of the relative intensities of the photoemission maxima with photon energy, and to some extent these relative intensities themselves, are correctly reproduced by the calculation