A quasiparticle calculation of the dispersion curves of gallium arsenide based on a full Hartree-Fock approximation

Abstract

We present for the first time a calculation of the one-electron excitations of gallium arsenide that explicitely accounts for the exchange nonlocality. The calculation has been performed in two steps: (1) An exact valence electron Hartree–Fock computation provides a self-consistent one-body density matrix and defines the one electron valence and conduction wave functions subspaces. (2) An effective Hamiltonian including screened exchange is constructed and diagonalized after projection onto the valence and the conduction subspaces separately. This leads to self-consistent dispersion curves that compare favorably with experimental data.