Open AccessSITE-DIAGONAL DISORDER AND OFF-DIAGONAL DISO-RDER AMORPHOUS QUANTUM DOTS ON DIAMOND LATTICE
Author(s) -
Zuo Du-Luo,
LI Dao-huo
Publication year - 1994
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.43.991
Subject(s) - condensed matter physics , quantum dot , amorphous solid , hamiltonian (control theory) , diamond , physics , diagonal , materials science , lattice (music) , quantum mechanics , chemistry , geometry , mathematics , crystallography , mathematical optimization , acoustics , composite material
The theoretical studies about site-diagonal disorder and off-diagonal disorder amorphous quantum. dots on diamond lattice are reported. We describe the electronic structures of the amorphous models by simple tight-binding Hamiltonian, solve the Ha-miltonian equation by recursion method, and study the localization behavior from the sensitivity of eigenvalues to a change in boundary conditions. It is found that if the band edges of amorphous quantum dots are consisted of extended states, the changing tendency of the band widths with size are similar to that of crystal quantum dots; if they are consisted of localized states, the band widths do not change with size when the size is greater than a critical one, but the densities of states at the band edges increase with size. The imaginary part of dielectric function ε2?ω of amorphous quantum dots is also studied. The ε2?ω corresponding to extended state is sensitive to the change of size. The ε2?ω corresponding to localized state has a small value and is insensitive to the change of size when the size is greater than localization length Lloc; when the size is close to or less than Lloc; there are no difierences between localized states and extended states, and ε2?ω increases quickly with the decrease of size.