Spectra and states of electrons in surface perturbed quantum wires

Abstract

The dispersion law and spectral weights of charge carriers in surface perturbed quantum wires were found using the two-time dependent anticommutator Green's function method. The allowed energy band of electrons is strictly discrete. The electron wave vector takes discrete values in the confinement directions. The number of discrete states increases with wire thickness. The influence of boundary perturbation parameters onto dispersion law and space distributions of electrons were analyzed. It turned out that the electron energies shift towards higher values when the electron energies localization on wire boundaries increase. By increase of the electron hopping terms in boundary planes, energy spectrum can out-throw bulk energy limits. Through boundary conditions variations it is possible to induce appearance of energy gaps inside the spectra (the energy band of quantum wire becomes narrower than the one of the bulk) or the appearance of localized states (their presence has been confirmed through the analysis of the spatial distribution of electrons). © 2001 Published by Elsevier Science B.V.