Probing of surface acoustic wave fields by a novel scanning tunneling microscopy technique: Effects of topography

Abstract

A new method for the investigation of SAW (surface acoustic wave) fields is presented using a modified version of a scanning tunneling microscope. By adding a high frequency sinusoidal signal to the dc tip voltage the tunneling current contains a component at the difference of the frequencies of this signal and the SAW. There is a remarkable variation of phase for areas much smaller than the SAW wavelength, due to different contributions of the normal and horizontal components of the SAW.