Room-Temperature Observation of Standing Electron Waves on GaAs(110) at Surface Steps.

Standing electron waves with a high coherence length were observed at steps of the GaAs(110) cleavage surface by scanning tunneling microscopy at room temperature. They are related to a two-dimensional electron gas in the GaAs conduction band caused by tip-induced band bending underneath a blunt tip. The simulated local density of states between two surface steps nicely describes the experimental corrugation. A self-consistent quantum-mechanical calculation of the potential variation demonstrates the dominant contribution of surface states with a high effective mass to the two-dimensional electron gas. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]