Scanning tunneling spectroscopy in Co-doped BaFe$_{2}$As$_{2}$: what density functional theory can tell us

We use density functional theory to simulate the scanning tunneling spectra and topographic images of Co-doped BaFe$_{2}$As$_{2}$. The matrix element effects are evaluated and the specific contributions of the different surface atoms to the spectra are considered. The results give a better understanding of the measured spectra and assess the resolution of STS measurements in these systems.