Field emission interferometry with the scanning tunneling microscope

A scanning tunneling microscope, operated in the near field emission regime , is used to obtain the phases of very low energy electrons reflected from a sample surface. A simple theoretical model shows that the spectrum of the electron standing waves, formed in the vacuum gap between the tip probe an d the sample, is directly related to the complex amplitudes of the reflecte d electron waves. The surface sensitivity of the interferometric spectra is demonstrated in the analysis of different reconstructions of the Pb/Si(111 ) system. (C) 1999 Elsevier Science B.V. All rights reserved.