Growth of nanopucks on Pb quantum islands

Two-dimensional periodic arrays of Pb nanopucks have been grown on Pb quantum islands at around 100 K using electronic superstructures on the island surface as templates. These superstructures originate from interfacial electron scattering. They are seen on the surface of Pb quantum islands grown on incommensurate Pb thin films on a Si(111)-7 × 7 surface. The rhombic unit cell of these superstructures can be divided into two triangles. Pb adatoms prefer to adsorb on the triangle with the face-centered cubic stacking. In an appropriate temperature range, the surface deposited atoms can hop more freely within the unit cell than across the cell boundary. The superstructures can thus serve as templates for the confined nucleation of nanopucks of deposited atoms.