Direct imaging of the two-dimensional Fermi contour: Fourier-transform STM

Abstract

Direct images of the two-dimensional Fermi contour at a surface can be generated by a Fourier transform (FT) of scanning tunneling microscopy (STM) images taken at low-bias voltages. The origins of the Fermi contour in the FT are the standing waves of electrons near the Fermi energy caused by defects in the surface. Several examples of FT-STM are presented to illustrate the simplicity of this technique. The advantages and limitations of this Fermi contour imaging technique are discussed.