196 research outputs found
The electronic structure of gallium nitride
No full textThe results of a density functional calculation on gallium nitride are given. We use norm-conserving pseudopotentials with sufficiently extended sets of plane waves to investigate the ground-state properties and the electronic band structure for the zincblende phase of GaN and compare them with the corresponding results for the wurtzite structure. A comparison with the outcomes of other calculations and with the existing experimental data is also given
An efficient method for calculating quasiparticle energies in semiconductors
No full textWe present a method for the efficient calculation of the electronic structure of semiconductors within the GW approach. It approximately includes dynamical-screening and local-field effects, previously disregarded in simplified GW approaches, without increasing the computational effort. Such effects substantially affect the gap corrections. We find quasiparticle shifts in good agreement with the complete GW calculations or experiment for Si, AlAs, GaAs and ZnSe
Erratum: Model dielectric function for semiconductors [Phys. Rev. B 47, 9892 (1993)] G. Cappellini,
No full textThere are three misprints in this paper.
(1) In the row relative to silicon in Table I, in the third column the number 0.075 is not correct; the correct number is
0.0705.
(2) In Eq. (9) after the first e one should insert (0) to obtain the correct symbol e(0).
(3) In Ref. 13 the correct list of authors is R. Daling, W. van Haeringen, and B. Farid. The other part of the reference
remains unchanged
Model dielectric function for semiconductors
No full textWe present a model for the dielectric function of semiconductors. It has been tested successfully for
Si, Ge, GaAs, and ZnSe. In conjunction with the single plasmon-pole approximation it yields plasmonenergy
dispersions in fair agreement with experiments. It allows one, moreover, to deduce an analytical
expression for the Coulomb-hole part of the static self-energy operator
An efficient method for calculating quasiparticle energies in semiconductors
No full textWe present a method for the efficient calculation of the electronic structure of semiconductors within the GW approach. It approximately includes dynamical-screening and local-field effects, previously disregarded in simplified GW approaches, without increasing the computational effort. Such effects substantially affect the gap corrections. We find quasiparticle shifts in good agreement with the complete GW calculations or experiment for Si, AlAs, GaAs and ZnSe
Apparent CO2 assimilation, 14C incorporation, and 14C translocation in spring barley influenced by sink manipulations.
No full textQuasiparticle energies and band gaps in semiconductors determined with an efficient DFT-GW scheme
No full textQuasiparticle energies and band gaps in semiconductors determined with an efficient DFT-GW schem
Local fields and dynamical screening effects on the semiconductors band gap
No full textLocal fields and dynamical screening effects
on the semiconductors band ga
Efficient calculation of the polarizability: a simplified effective-energy technique
No full textIn a recent publication [J.A. Berger, L. Reining, F. Sottile, Phys. Rev. B 82, 041103(R) (2010)] we introduced the effective-energy technique to calculate in an accurate and numerically efficient manner the GW self-energy as well as the polarizability, which is required to evaluate the screened Coulomb interaction W. In this work we show that the effective-energy technique can be used to further simplify the expression for the polarizability without a significant loss of accuracy. In contrast to standard sum-over-state methods where huge summations over empty states are required, our approach only requires summations over occupied states. The three simplest approximations we obtain for the polarizability are explicit functionals of an independent- or quasi-particle one-body reduced density matrix. We provide evidence of the numerical accuracy of this simplified effective-energy technique as well as an analysis of our method
State mixing for quasiparticles at surfaces: Nonperturbative GW approximation
No full textWe present ab initio calculations for both the wave functions and the energies of single quasiparticles. The conventional quasiparticle approach evaluates energy-level corrections to first order in the difference between the self-energy and the Kohn-Sham exchange-correlation potential. Here,we also recalculate the quasiparticle states. At the example of the GaAs(110) surface we show that this nonperturbative treatment is important far surfaces with electronic states close in energy but different with respect to their localization. As a sensitive observable the reflectance anisotropy is studied. [S0163-1829(99)15947-2]
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