Empirical relation between Pauling electronegativity and self-energy cutoffs in local-density approximation-1/2 quasi-particle approach applied to the calculation of band gaps of binary compound semiconductors

2016 ◽  
Vol 6 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Mauro Ribeiro
Keyword(s):  
Local Density ◽  
Empirical Relation ◽  
Binary Compound ◽  
Band Gaps ◽  
Density Approximation ◽  
Quasi Particle ◽  
Self Energy ◽  
Image Position ◽  
Pauling Electronegativity ◽  
Particle Approach

Abstract

A comparative study on the LDA + U and hybrid functional methods on the description of the electronic structure of YTiO3 under high pressure

2009 ◽  
Vol 87 (10) ◽  
pp. 1374-1382 ◽  
Author(s):  
Z. Song ◽  
J. J. Yang ◽  
J. S. Tse
Keyword(s):  
Electronic Structures ◽  
Local Density ◽  
Band Gaps ◽  
Density Approximation ◽  
Hybrid Functional ◽  
Functional Methods ◽  
Mixing Parameters ◽  
Hubbard U ◽  
Hubbard Parameter ◽  
Pressure Analysis

The electronic structures of YTiO3 under pressure have been studied with LDA + U (local density approximation + Hubbard parameter) and hybrid functional methods. From matching the experimental band gaps, the Hubbard U and hybrid functional mixing parameters were determined. It is found that both parameters vary with the pressure. Analysis of the electronic structures indicates that the description of the chemical bonding is also dependent on the method of choice.

scholarly journals Nuclear structure dependence of the coherent (μ-,e-) conversion matrix elements

2020 ◽  
Vol 4 ◽  
pp. 215
Author(s):  
T. S. Kosmas ◽  
Amand Faessler ◽  
F. Simkovic ◽  
J. D. Vergados
Keyword(s):  
Ground State ◽  
Transition Matrix ◽  
State Transition ◽  
Local Density ◽  
Density Approximation ◽  
Matrix Elements ◽  
Quasi Particle ◽  
Electron Conversion ◽  
Transition Matrix Elements ◽  
Conversion Matrix

Coherent rates for the neutrinoless muon to electron conversion. (μ-, e-) in the presence of nuclei, are studied throughout the periodic table. The relevant ground state to ground state transition matrix elements are obtained in the context of the quasi-particle RPA. The results are discussed in view of the existing experimental data extracted at TRIUMF and PSI for 48Ti and 208Pb nuclei and compared with: (i) the single particle shell model results calculated with a determinantal ground state wave function and (ii) the results deduced in a local density approximation.

scholarly journals Electronic structure and optical properties of (BeTe)n/(ZnSe)m superlattices

2016 ◽  
Vol 34 (1) ◽  
pp. 115-125 ◽  
Author(s):  
M. Caid ◽  
H. Rached ◽  
D. Rached ◽  
R. Khenata ◽  
S. Bin Omran ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Electronic Structure ◽  
Ground State ◽  
Optical Constants ◽  
Local Density ◽  
Band Gaps ◽  
Full Potential ◽  
Density Approximation ◽  
Binary Compounds

AbstractThe structural, electronic and optical properties of (BeTe)n/(ZnSe)m superlattices have been computationally evaluated for different configurations with m = n and m≠n using the full-potential linear muffin-tin method. The exchange and correlation potentials are treated by the local density approximation (LDA). The ground state properties of (BeTe)n/(ZnSe)m binary compounds are determined and compared with the available data. It is found that the superlattice band gaps vary depending on the layers used. The optical constants, including the dielectric function ε(ω), the refractive index n(ω) and the refractivity R(ω), are calculated for radiation energies up to 35 eV.

scholarly journals Ab InitioStudy of Strain Effects on the Quasiparticle Bands and Effective Masses in Silicon

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammed Bouhassoune ◽  
Arno Schindlmayr
Keyword(s):  
Electronic Properties ◽  
Effective Mass ◽  
Local Density Approximation ◽  
Field Effect Transistors ◽  
Local Density ◽  
Energy Splitting ◽  
Density Approximation ◽  
Self Energy ◽  
Effective Masses ◽  
Structural And Electronic Properties

Usingab initiocomputational methods, we study the structural and electronic properties of strained silicon, which has emerged as a promising technology to improve the performance of silicon-based metal-oxide-semiconductor field-effect transistors. In particular, higher electron mobilities are observed inn-doped samples with monoclinic strain along the [110] direction, and experimental evidence relates this to changes in the effective mass as well as the scattering rates. To assess the relative importance of these two factors, we combine density-functional theory in the local-density approximation with theGWapproximation for the electronic self-energy and investigate the effect of uniaxial and biaxial strains along the [110] direction on the structural and electronic properties of Si. Longitudinal and transverse components of the electron effective mass as a function of the strain are derived from fits to the quasiparticle band structure and a diagonalization of the full effective-mass tensor. The changes in the effective masses and the energy splitting of the conduction-band valleys for uniaxial and biaxial strains as well as their impact on the electron mobility are analyzed. The self-energy corrections withinGWlead to band gaps in excellent agreement with experimental measurements and slightly larger effective masses than in the local-density approximation.

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