Simulation of STM images of three-dimensional surfaces and comparison with experimental data: Carbon nanotubes

Abstract

Computer simulation by numerically solving the time-dependent Schr\"odinger equation was used to investigate image formation during scanning tunneling microscope (STM) imaging of three-dimensional objects with radii of curvature comparable with that of the STM tip. The results were compared with experiment. When the nanotube is placed on a substrate with similar electronic structure, the only distortion arises from geometric convolution. When the substrate and the nanotube have different electronic structures, additional distortions arise. The time evolution of the tunneling process shows that in the interpretation of the scanning tunneling spectroscopy data one has to take into account the nanotube not being an integral part of the underlying substrate.