Photoemission theory for nonlocal potentials: application to Ni(100)

A one-step theory of photoemission for nonlocal potentials which overcomes different limitations of the original theory has been applied to Ni(100). T he theory is formulated for one-particle potentials and general nonlocal, c omplex and energy-dependent self-energies. It applies to semi-infinite latt ices with perfect lateral translational invariance and arbitrary number of atoms per unit cell. In the framework of this theory the final state is cal culated using multiple scattering techniques. The initial state, which is d escribed by the energy- and temperature dependent spectral function, result s from a combination of a one-particle slab calculation with many-body tech niques. Here we present temperature-dependent photoemission intensities cal culated for different excitation energies from the (100)surface of ferromag netic Ni. (C) 2000 Elsevier Science B.V. All rights reserved.