Observation of Landau levels at the InAs(110) surface by scanning tunneling spectroscopy

Abstract

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