Analysis of STM images with pure and CO-functionalized tips: A first-principles and experimental study

Abstract

We describe a first principles method to calculate scanning tunneling microscopy (STM) images, and compare the results to well-characterized experiments combining STM with atomic force microscopy (AFM). The theory is based on density functional theory (DFT) with a localized basis set, where the wave functions in the vacuum gap are computed by propagating the localized-basis wave functions into the gap using a real-space grid. Constant-height STM images are computed using Bardeen's approximation method, including averaging over the reciprocal space. We consider copper adatoms and single CO molecules adsorbed on Cu(111), scanned with a single-atom copper tip with and without CO functionalization. The calculated images agree with state-of-the-art experiments, where the atomic structure of the tip apex is determined by AFM. The comparison further allows for detailed interpretation of the STM images.

arXiv comment10 pages, 9 figures

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Cited by in corpus (4)

• Lateral manipulation with combined atomic force and scanning tunneling microscopy using CO-terminated tips
• Atomic Force Extrema Induced by the Bending of a CO-Functionalized Probe
• Scanning tunneling microscopy using CO-terminated probes with tilted and straight geometries
• STM contrast of a CO dimer on a Cu(1 1 1) surface: a wave-function analysis