Influence of electronic structure on the topography of Ge(100) and Si(100) surfaces in scanning tunneling microscopy

The analysis of scanning tunneling microscopy images for $c$(4 $\times$ 2) and $p$(2 $\times$ 2) reconstructions on the (100) face of germanium and silicon, which are simulated using the density functional theory and measured at 12 K, has been performed. It is shown that depending on the sign and magnitude of the bias voltage, the appearance of these images can be significantly transformed, and the observed topographic relief can to a greater extent reflect the atomic geometry or electronic structure features of the surface. The obtained results demonstrate that when interpreting scanning tunneling microscopy data for these reconstructions, it is necessary to carefully consider a number of factors, including detailed knowledge of the local density of states.