ARPES spectral function near a Mott transition

Abstract

Abstract An interpolation formula, connecting the high and low energy expansions of a momentum resolved Green function G ( k , ω ) was first outlined in: K. Matho, J. Phys. Chem. Solids 56 (1995) 1735. Here, the algorithm is presented in detail, allowing to calculate the interpolated spectrum for all energies. The high energy part is given by a Pade approximant of arbitrary order. The low energy scenario, with a large Fermi surface, is either backed up by microscopic manybody theory or suggested by phenomenological considerations. The algorithm itself decides, whether the two scenarios to be interpolated are compatible with each other. As an application, we give an in depth discussion of a correlated photohole, as observable in photoemission experiments. The emphasis is on experimental and theoretical exploration of generic low energy features, in agreement with the overall electronic structure of real materials. The context of doped, metallic Mott–Hubbard systems is chosen to indicate ways of modeling correlated spectra in the presence of strong onsite repulsion U and in finite dimension d =2 or d =3.