Anisotropic contributions to the optical potential employed in theoretical treatments of electron spectroscopies

Publisher Website
Google Scholar
Abstract
An analysis is presented which indicates that anisotropic contributions to the optical potential can be caused by the broken symmetry of a surface. This anisotropy is not related to surface plasmons and extends a few layers into the surface region. The anisotropic contributions have been estimated for a simple metal and shown to be of the same order of magnitude as the isotropic contributions. To test possible influences of the anisotropy, a model low-energy electron diffraction (LEED) calculation has been performed. Our results do not show major changes in the LEED I-V profiles, which serve to lend additional credence to previous LEED analyses in which isotropic optical potentials were used. However, it is pointed out that the anisotropic contributions could produce larger effects in other electron spectroscopies (e.g., photoemission).