Single atom extraction by scanning tunneling microscope tip-crash and   nanoscale surface engineering
  We report a novel atom extraction mechanism from the native substrate by means of a scanning tunneling microscope tip-crash on a Ag(111) surface at 5 K. Individual atoms are scattered on the surface when a silver coated tip is dipped into the substrate at low tunneling biases. Quantitative analyses reveal that the mechanical energy supplied by the tip-crash dominates the atom extraction process. Application of this procedure is demonstrated by constructing quantum structures using the extracted atoms on an atom-by-atom basis. 
Saw Wai Hla, Kai-Felix Braun, Violeta Iancu, Aparna Deshpande