Monoatomic Chains Deposited onto Silicon Steps Studied by Density Functional and Scattering Theories

Abstract

ABSTRACTThe purpose of this study is the assessment of the properties of deposited atomic chains. Therefore linear chains of covalent and metallic atoms, i.e. As and Ag,deposited onto monolayer SA steps onto Si(100) have been considered. Their study is based on a semi-empirical Hamiltonian, used for the evaluation of both the electronic structure and the conductance, and the calaculations analyze the binding energy of chains of variable length deposited onto steps in the light of the analogous energy of free-standing chains and of chains deposited onto the Si(100) surface. This comparison shows that the stability of the chains has a primary dependence on the type of the substrate, rather than on the chain length and composition, and increases in the order: free standing,deposited onto SA,deposited onto Si(100). The central result of the calculations of the conductance is that the dependence on the type of the substrate and on the chain composition parallels the one of the binding energy.