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Title: Dielectric function for a model of laser-excited GaAs

We consider a model for the ultrashort pulsed-laser excitation of GaAs in which electrons are excited from the top of the valence band to the bottom of the conduction band. The linear optical response of this excited system in the visible and near-UV is calculated by solving a statically screened Bethe-Salpeter equation. Single-particle electron energies and wave functions are taken from ab initio electronic structure calculations. The screened electron-hole interaction W is calculated with a model dielectric function which includes the excited carriers. Though band-gap renormalization is neglected, dramatic changes are observed in the shape of {epsilon}{sub 2}({omega}) due to Pauli blocking and the enhanced screening of W. We estimate the error incurred in the static screening approximation by performing static screening calculations with the assumption that the excited carriers respond too slowly to screen W.
Authors:
Publication Date:
OSTI Identifier:
40205562
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 63; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevB.63.075202; Othernumber: PRBMDO000063000007075202000001; 059107PRB; PBD: 15 Feb 2001
Publisher:
The American Physical Society
Sponsoring Org:
(US)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BETHE-SALPETER EQUATION; DIELECTRIC MATERIALS; ELECTRONIC STRUCTURE; ELECTRONS; EXCITATION; RENORMALIZATION; SCREENS; SHAPE; VALENCE; WAVE FUNCTIONS