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The Band-Gap Problem in Semiconductors Revisited: Effects of Core States and Many-Body Self-Consistency

Wei Ku·A. G. Eguiluz
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Abstract

A novel picture of the quasiparticle (QP) gap in prototype semiconductors Si and Ge emerges from an analysis based on all-electron, self-consistent, GW calculations. The deep-core electrons are shown to play a key role via the exchange diagram --if this effect is neglected, Si becomes a semimetal. Contrary to current lore, the Ge 3d semicore states (e.g., their polarization) have no impact on the GW gap. Self-consistency improves the calculated gaps --a first clear-cut success story for the Baym-Kadanoff method in the study of real-materials spectroscopy; it also has a significant impact on the QP lifetimes. Our results embody a new paradigm for ab initio QP theory.

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Wei Ku, A. G. Eguiluz. 2002-03-26. The Band-Gap Problem in Semiconductors Revisited: Effects of Core States and Many-Body Self-Consistency. https://doi.org/10.1103/physrevlett.89.126401

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