Regensburg 2000 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 42: Elektronentheorie
HL 42.6: Vortrag
Freitag, 31. März 2000, 11:45–12:00, H14
Quasiparticle calculations of the band structure of HgSe, HgTe and β-HgS — •Andrzej Fleszar and Werner Hanke — Theoretische Physik I, Uni Würzburg, 97074 Würzburg
HgSe, HgTe and β-HgS are materials for which the LDA band structure
brakes down dramatically. In all of them the (negative) gap is about 5 times
too big, in HgSe and HgTe the spin-orbit splitting is ∼ 0.2 eV too
small and in β-HgS the ordering of Γ7 and Γ8
states is reversed, thus leading to an ’exotic’ insulating configuration.
In a recent GW quasiparticle calculation for HgSe [1] the obtained band
structure was apparently similar to the experimentally acepted model.
It was suggested in that paper that the Γ7 and Γ6 states
are in a different ordering as experimentally accepted. In our paper
we reproduce the results of [1] for HgSe and, in addition, calculate the
quasiparticle GW bands for HgTe and β-HgS. We show that in none
of these materials the GW band structure works fully satisfactory.
Although it largely improves the (negative) energy gaps, the remaining
difference with experiment is still pronounced and the spin-orbit
splittings are not corrected.
[1] M.Rohlfing and S.G.Louie, Phys. Rev. B 57, R9392 (1998).