Microscopic mechanism of templated self-assembly: Indium metallic atomic wires on Si(553)-Au

We report on the self-assembly of metallic atomic wires utilizing a templated semiconductor surface. A well-ordered template is provided by a vicinal Si surface reacted with Au, Si(553)-Au, which has a regular and robust step array. The scanning tunneling microscopy study shows that In atoms preferentially adsorb and diffuse actively along step edges to form well-ordered atomic wires. The local spectroscopy indicates the metallic property of In atomic wires formed. Ab initio calculations reveal the microscopic mechanism of the templated self-assembly as based on well-aligned preferential adsorption sites and the strongly anisotropic surface diffusion. This template can, thus, be widely applied to fabricate various atomic or molecular wires.