The conductance of monoatomic As and Ag chains deposited onto silicon steps evaluated using a simplified scattering approach

The purpose of this study is the assessment of the properties of the conductance of deposited atomic chains. Therefore, linear chains of covalent and metallic atoms, i.e. As and Ag, deposited onto monolayer steps of the Si(1 0 0) surface have been considered. The study is based on the extended Hu¨ ckel theory, used for the evaluation of both the electronic structure and the conductance, and the calculations analyze the binding and adsorption energies of chains of variable length deposited onto SA steps in the light of the similar properties of free standing chains and of chains deposited onto the flat Si(1 0 0) surface. This comparison shows that the stability of the chain depends on its composition, rather than on its length, and increases in the order: free standing, deposited onto SA, deposited onto Si(1 0 0). The central result of the calculations of the conductance is that the dependence of this quantity on the chain length and composition and on the type of substrate parallels the one of the characteristic energies.