Self-growth of ordered Ag nanopuck arrays on electronic patterns of 2D Pb quantum islands

The electronic Moiré patterns found on 2D Pb quantum islands are employed as the templates to grow self-organized Ag nanopucks. Electronic origin of these patterns is attributed to the phase shift induced by the interfacial potential variation, which is in turn resulted from the lattice mismatch. The interfacial potential variation will affect the adatom diffusion on the island surface and can be applied to grow nanopucks of desired materials. Periodic patterns of inhomogeneous electron density distributing near the Fermi level should dictate the interaction between the substrate and the adatom. Owing to a strong interaction existing between Ag and the substrate, nearly perfect two-dimensional arrays of Ag nanopucks can be grown from 70 K to 150K. Utilizing the notable feature of Ag nanopucks, the signature of the electronic Moiré patterns of Pb quantum islands, manifesting a bi-layer complementarily alternating image contrast, can be made apparent.