Apparent charge transfer at theGexPb1−x/Ge(111)interface

Abstract

We investigate the apparent charge transfer between adatoms in the ${\mathrm{Ge}}_{x}{\mathrm{Pb}}_{(1\ensuremath{-}x)}/\mathrm{Ge}(111)$ interface both experimentally and theoretically. Scanning tunneling microscopy and surface core-level measurements suggest significant charge transfer from the Ge adatoms to the Pb adatoms. However, first-principles calculations unambiguously find that the total electronic displacement is negligibly small and that the results of published experiments can be explained as a result of bond rearrangement.