Reversible Vertical Manipulations of Single Pt Adatom on Pt(111) Surface with a Triple-Apex Tip

With a triple-apex tip, we investigate theoretically the vertical manipulation of single Pt adatom on the Pt(111) surface. The adatom adsorbed on the fcc site of the flat Pt(111) surface can be transferred vertically to the tip by adjusting the tip height properly. Moreover, based on the strong vertical trapping ability and the relatively weak lateral trapping ability of the tip, we propose a simple method to realize a reversible vertical manipulation of the Pt adatom from the highly coordinated sites, the kink and the step sites, of the stepped Pt(111) surface. All the vertical manipulations are completed using only the atomic force between the tip and the adatom, without the electric field.