Real space observation of standing waves at metal surfaces and the determination of surface state dispersion with the scanning tunneling microscope

Abstract

Standing waves produced by the scattering and interference of surface state electrons by surface steps and adsorbates are observed in real space using scanning tunneling spectroscopy (STS). From the structure of the standing waves, the wave number of the surface electrons can be obtained as a function of the electron energy. Here we compare the thus obtained dispersion with the results of angle-resolved photoemission and the predictions of a simple theoretical model. Based on these comparisons we determine the best way of performing the STS experiment and analyze the results to obtain a reliable measure of the dispersion of surface states. © 1994 The Japan Society of Applied Physics.