Application of Maxent to Inverse Photoemission Spectroscopy

Information about the spectral density gained by inverse photoemission spectroscopy is distorted by the Fermi distribution and the apparatus function. In many cases recovery of the desired physical quantities is hampered by an ill-posed inversion problem. It is shown, based on the spin- and temperature dependent quasiparticle spectrum of Ni, that the maximum entropy method yields unbiased access to the spectral density independent of model assumptions. The effective energy resolution is thereby improved by a factor of 5 and structures below the Fermi level E F , which are generally lost in inverse photoemission, are recovered.