All-electron quasi-particle self-consistent $GW$ band structures for SrTiO${}_3$ including lattice polarization corrections in different phase

Abstract

The electronic band structure of SrTiO${}_3$ is investigated in the all-electron QS$GW$ approximation. Unlike previous pseudopotential based QS$GW$ or single-shot $G_0{W}_0$ calculations, the gap is found to be significantly overestimated compared to experiment. After putting in a correction for the underestimate of the screening by the random phase approximation in terms of a 0.8$\Sigma$ approach, the gap is still overestimated. The 0.8$\Sigma$ approach is discussed and justified in terms of various recent literature results including electron-hole corrections. Adding a lattice polarization correction (LPC) in the $\mathbf{q}\to 0$ limit for the screening of $W$, agreement with experiment is recovered. The LPC is alternatively estimated using a polaron model. We apply our approach to the cubic and tetragonal phases as well as a hypothetical layered post-perovskite structure and find that the LDA (local density approximation) to $GW$ gap correction is almost independent of structure.

9 pages, 4 figures

References in corpus (7)

• Quasiparticle self-consistent $GW$ method; a basis for the independent-particle approximation
• Efficient implementation of the GW approximation within the all-electron FLAPW method
• Maximally-localized Wannier functions for GW quasiparticles
• Estimating Excitonic Effects in the Absorption Spectra of Solids: Problems and Insight from a Guided Iteration Scheme
• Quasiparticle self-consistent GW method based on the augmented plane-wave and muffin-tin orbital method
• Lattice polarization effects on the screened Coulomb interaction $W$ of the GW approximation
• Strain-Induced Conduction Band Spin Splitting in GaAs from First Principles Calculations

Cited by in corpus (1)

• Quasiparticle self-consistent $GW$ band structures of Mg-IV-N${}_2$ compounds: the role of semicore $d$ states