Electronic properties of a quantum wire interacting with a surface: the role of periodically placed impurities

Abstract

The transmittance and density of states (DOS) of a quantum wire which is tunnel coupled to the underlying substrate are investigated theoretically using the retarded Green's function method. The wire is composed of periodically placed impurities with Coulomb interactions and is modeled by a tight-binding Hamiltonian within the mean-field approximation. For a given periodicity of impurities along the wire we observe energy gaps in the structure of DOS. These gaps disappear for a wire coupled with the substrate electrode with localized electrons which leads to a metal-insulator transition in the system. Our numerical studies reveal that the transmittance through the system strongly depends on whether or not the substrate electrons are localized.

Correlation between morphology, electron band structure, and resistivity of Pb atomic chains on the Si(5 5 3)-Au surface

“…Such a chain-substrate system is characterized by the energy gap at the Fermi level in the density of states. It is known that for regularly placed impurities along a wire, depending on the periodicity of impurities, energy gaps in the structure of the density of states appear [45]. In the next step, for the coverage between 16.6%-50% the second atomic chain (C2) with a single lattice constant is fabricated on the terrace (figure 6(c)).…”