Premium
Impurity Effects on the Local Density of States of an Hexagonal Husumi Cactus
Author(s) -
Glass B.,
Lazo E.
Publication year - 1993
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221800115
Subject(s) - hamiltonian (control theory) , impurity , diagonal , condensed matter physics , hexagonal crystal system , tight binding , physics , electronic structure , chemistry , quantum mechanics , crystallography , mathematics , geometry , mathematical optimization
The electronic structure of a hexagonal Husumi cactus with a finite number of substitutional impurities in essentially two different cases is studied: (i) one impure hexagon in a pure Husumi cactus system and (ii) a Husumi cactus formed by infinite repetition of a contaminated hexagon (heterocactus). The tight‐binding Hamiltonian is used considering interaction to nearest neighbors and one orbital per site, with diagonal and off‐diagonal disorder. The Dyson equation describing the electron dynamics is solved using two types of effective transfer matrices. Localized states appear in the electronic gap for the heterocactus formed by infinite repetition of a hexagon with two impurities on sites 1. All genuine heterocactuses generate a gap, but only one has a localized state in between as a function of the normalized self‐energy ϵ.