Ab initio determination of the optical properties of bulk Au and free surfaces of Au

Abstract

The optical properties of bulk Au and a (100) free surface of Au are determined by solving the Helmholtz-Fresnel equations for a geometry reflecting layered systems. This approach is based on the use of the microscopical conductivity tensor evaluated fully relativistically and, for later purposes, does include the option of choosing an arbitrary uniform direction of a possibly present magnetization. It will be shown that, while so-called experimental bulk data agree reasonably well with their theoretically obtained counterparts, in the case of free surfaces of Au (semi-infinite systems) they not only disagree substantially in size between different experiments but also with the theoretical values. The shapes of the curves for the real and the imaginary parts of the diagonal permittivity tensor elements εxx and εzz, however, are rather similar.