Monatomic steps on reconstructed : A long-period diffraction grating for surface electron wavesM. Wenderoth, K. J. Engel and R. G. Ulbrich
IV. Physikalisches Institut der Universität Göttingen Tammannstr. 1, D-37073 Göttingen, Germany
(Received 14 January 2004; accepted in final form 4 June 2004)
The interference pattern of surface state electrons which are scattered from monatomic steps on the surface is studied with Scanning Thermovoltage Microscopy at 80 kelvin. The step contours are periodically modulated by the underlying herringbone surface reconstruction and act like a long-period diffraction grating. This leads to a characteristic rhomb-shaped interference pattern in front of the step (Talbot effect). A simulation of electron scattering from such steps shows good agreement with our experiments and allows the interpretation of earlier data in a new and consistent way. We rule out the confinement of surface states due to the reconstruction potential is responsible for the observed wave pattern.
73.20.At - Surface states, band structure, electron density of states.
72.10.Fk - Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect).
68.37.Ef - Scanning tunneling microscopy (including chemistry induced with STM).
© EDP Sciences 2004