OBSERVATION OF LANDAU-LEVELS AT THE INAS(110) SURFACE BY SCANNING TUNNELING SPECTROSCOPY

Low-temperature scanning tunneling spectroscopy measurements on clean InAs(110) surfaces demonstrate the possibility to investigate Landau q uantization with subnanometer resolution. Separate Landau levels are r esolved at magnetic fields of 2 T and larger. Experiments with differe nt tips show a significant tip dependence. In zero field resonances ar e observed near the onset of the conduction band, which are attributed to tip-induced band bending. Although Landau quantization is only pre sent parallel to the sample surface, the Landau levels give a large co ntribution to the total tunnel current.