Electronic states in trigonal Se and Te: A tight-binding model Hamiltonian

1977 ◽  
Vol 39 (1) ◽  
pp. 135-146 ◽  
Author(s):  
F. Nizzoli
Keyword(s):  
Tight Binding ◽  
Electronic States ◽  
Tight Binding Model ◽  
Binding Model ◽  
Model Hamiltonian

MAGNETIC PROPERTIES OF ICOSAHEDRAL COPPER-COATED COBALT CLUSTERS

2004 ◽  
Vol 11 (01) ◽  
pp. 15-20 ◽  
Author(s):  
BAOLIN WANG ◽  
XIAOSHUANG CHEN ◽  
GUIBIN CHEN ◽  
GUANGHOU WANG ◽  
JIJUN ZHAO
Keyword(s):  
Genetic Algorithm ◽  
Magnetic Properties ◽  
Magnetic Moment ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Significant Modification ◽  
Binding Model ◽  
Model Hamiltonian ◽  
Spin Polarized ◽  
Structural And Magnetic Properties

The structural and magnetic properties of Cu -coated Co clusters are investigated with empirical genetic algorithm simulation and a spin-polarized spd tight-binding model Hamiltonian. In some specific stoichiometric compositions, icosahedral Co n (n=1, 2, 4, 7, 13, 19, 55) clusters perfectly coated with A Cu monolayer or dual layer are obtained. The outer Cu layers lead to significant modification of the magnetic moment of the Co core, depending on the structure and thickness of the Cu layers. The interaction between Cu and Co atoms induces a nonzero magnetic moment for Cu atoms.

Electronic States of BCN Alloy Nanotubes in a Simple Tight-Binding Model

2003 ◽  
Vol 72 (10) ◽  
pp. 2656-2664 ◽  
Author(s):  
Tomoaki Yoshioka ◽  
Hidekatsu Suzuura ◽  
Tsuneya Ando
Keyword(s):  
Tight Binding ◽  
Electronic States ◽  
Tight Binding Model ◽  
Binding Model

scholarly journals Calculations on Electronic States in QDs with Saturated Shapes

2003 ◽  
Vol 02 (01n02) ◽  
pp. 37-48 ◽  
Author(s):  
Wei Cheng ◽  
Shang-Fen Ren
Keyword(s):  
Quantum Dots ◽  
Group Theory ◽  
Size Range ◽  
Tight Binding ◽  
Electronic States ◽  
Spherical Shape ◽  
Irreducible Representations ◽  
Tight Binding Model ◽  
Binding Model ◽  
Ge Quantum Dots

Electronic States of Si and Ge QDs of 5 to 3127 atoms with saturated shapes in a size range of 0.57 to 4.92 nm for Si and 0.60 to 5.13 nm for Ge are calculated by using an empirical tight-binding model combined with the irreducible representations of the group theory. The results are compared with those of Si and Ge quantum dots with spherical shape. The effects of the shapes on electronic states in QDs are discussed.

THEORETICAL ANALYSIS OF THE OPTICAL-ABSORPTION TAIL IN AMORPHOUS SEMICONDUCTOR SUPERLATTICES

1989 ◽  
Vol 03 (01) ◽  
pp. 135-161 ◽  
Author(s):  
FUMIKO YONEZAWA ◽  
KEIKO ISHIDA ◽  
FUMITOSHI SATO
Keyword(s):  
Tight Binding ◽  
Amorphous Semiconductor ◽  
Tight Binding Model ◽  
Exponential Tail ◽  
Semiconductor Superlattices ◽  
Binding Model ◽  
Layer Width ◽  
Photovoltaic Efficiency ◽  
Model Hamiltonian ◽  
Absorption Tail

We propose a two-band tight-binding model Hamiltonian to describe the behaviour of electrons in amorphous semiconductor superlattices. Our model Hamiltonian is characterized by its off-diagonal terms υz in direction z which is perpendicular to layers in a superlattice; we define υz as a parameter which represents the dimension of well layers accompanying the change in a well-layer width Lw under the condition that a barrier-layer width is fixed. On the basis of this model, we calculate the density of states D(E) and the absorption spectra I(E), from which we estimate the exponential-tail widths E0 and Eu of D(E) and I(E), respectively. We discuss the ways in which these widths E0 and Eu are influenced (i) by the dimension of the system, (ii) by the dispersion of well-layer widths and (iii) by the degree of disorder. We also propose the possibility to improve the photovoltaic efficiency in solar cells composed of amorphous semiconductor superlattices.

DETAILS ON THE “LIMIT” MODEL OF CuO2 PLANES

1994 ◽  
Vol 08 (21n22) ◽  
pp. 1387-1391 ◽  
Author(s):  
DANIEL C. MATTIS
Keyword(s):  
Lower Bound ◽  
Ground State ◽  
State Energy ◽  
Tight Binding ◽  
Electronic States ◽  
Exact Results ◽  
Tight Binding Model ◽  
Binding Model ◽  
Limit Model ◽  
Higher Order Terms

We discuss a limiting procedure for solving for the electronic states in the standard tight-binding model of electrons in a CuO 2 plane, in which all contributions O (t2/U) are retained while all higher order terms are rejected. This limiting process yields the exact results in strong coupling, and uncovers a variety of quasiparticles: fermions with and without dispersion, localized spin-1 triplets, their interactions, but no superconductivity. In this paper we fill in some minor details and give a lower bound to the ground state energy valid at all ratios of t/U. We discuss the dynamic process by which two triplets can annihilate, and show that their lifetime is inversely proportional to their energy.

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