Basic Steps of Lateral Manipulation of Single Atoms and Diatomic Clusters with a Scanning Tunneling Microscope Tip

Detailed tip height measurements during manipulation of single atoms, molecules, and dimers on a Cu(211) surface reveal different manipulation modes depending on tunneling parameters. Both attractive (Cu, Pb, Pb dimers) and repulsive manipulation (CO) are identified. Using attractive forces, discontinuous hopping of Cu and Pb atoms from one adsorption site to the next can be induced (``pulling''). Pb dimers can be pulled with repeated single, double, and triple hops. Pb atoms can also be ``slid'' continuously. The occurrence of different movement patterns is shown to be a sensitive probe for surface defects.