A novel direct method of Fermi Surface determination using constant initial energy angle-scanned photoemission spectroscopy

We show that a constant initial energy, angle-scanned (CIE-AS) photoemission spectrum for emission from the Fermi energy (E(F)) contains Fermi surface (FS) signatures which originate from density of states type indirect transitions. Such previously unrecognized FS features in a CIE-AS spectrum would provide a robust and straightforward means of determining Fermi surfaces. Furthermore, the associated photointensity should yield a new window on k(perpendicular to), dispersion related issues in materials. Extensive simulations of CIE-AS spectra from low index faces of Cu are presented within the framework of the one-step photoemission model in order to delineate the nature of these new spectral features.