Atom-by-atom extraction by controlling a scanning tunneling microscope tip- cluster interaction

We present a novel atom-by-atom extraction scheme using scanning tunneling microscope (STM) manipulations on a Ag(111) surface at 6K under an ultra-high-vacuum condition. At the initial step, a silver nanocluster is deposited on the surface by gently touching the silver coated tip onto the surface. Individual silver atoms from the cluster are then extracted by precisely controlling the tip-cluster interactions. The recorded STM tip height signals reveal atomistic details of the atom extraction dynamics. The experimental findings are corroborated by total energy calculations based on interaction potentials using the embedded atom method.