Nanopatterning the electronic properties of gold surfaces with self-organized superlattices of metallic nanostructures

The self-organized growth of nanostructures on surfaces could offer many advantages in the development of new catalysts, electronic devices and magnetic data-storage media(1-5). The local density of electronic states on the surface at the relevant energy scale strongly influences chemical reactivity(6-9), as does the shape of the nanoparticles(10). The electronic properties of surfaces also influence the growth and decay of nanostructures such as dimers, chains and superlattices of atoms or noble metal islands(9,11-16). Controlling these properties on length scales shorter than the diffusion lengths of the electrons and spins ( some tens of nanometres for metals) is a major goal in electronics and spintronics(17). However, to date, there have been few studies of the electronic properties of self-organized nanostructures(18-20). Here we report the self-organized growth of macroscopic superlattices of Ag or Cu nanostructures on Au vicinal surfaces, and demonstrate that the electronic properties of these systems depend on the balance between the confinement and the perturbation of the surface states caused by the steps and the nanostructures' superlattice. We also show that the local density of states can be modified in a controlled way by adjusting simple parameters such as the type of metal deposited and the degree of coverage.