Electronic effects in scanning tunneling microscopy of graphite: A Green’s-function calculation based on the tight-binding model
Phys. Rev. B 54, 11777 – Published 15 October, 1996
DOI: https://doi.org/10.1103/PhysRevB.54.11777
Abstract
We show that the features of the scanning-tunneling-microscopy STM images of graphite can be understood within a simple tight-binding model of the tip-surface system. Using Green’s-function techniques, we are able to go beyond the usual Tersoff and Hamann formalism and include the effect of the bias voltage and tip-surface coupling on the tunneling current. We show that the tunneling current is very sensitive to the different crystallographic stacking arrangements of graphite, due to their influence on the local density of states both at and near the Fermi level. In addition, we find that the relative corrugation of the STM image depends strongly upon the nature of the tip-surface interaction. We conclude with a discussion of the extension of our formalism to include surface defects and adsorbates. © 1996 The American Physical Society.