Improvement on the GW$Γ$ Scheme for the Electron Self-Energy and Relevance of the $G_0W_0$ Approximation from this Perspective

Soh Ishii; Hideaki Maebashi; Yasutami Takada

paper

Improvement on the GW $Γ$ Scheme for the Electron Self-Energy and Relevance of the $G_{0} W_{0}$ Approximation from this Perspective

arXiv:1003.3342

Abstract

Based on an exact functional form derived for the three-point vertex function $Γ$ , we propose a self-consistent calculation scheme for the electron self-energy with $Γ$ always satisfying the Ward identity. This scheme is basically equivalent to the one proposed in 2001, but it is improved in the aspects of computational costs and its applicability range; it can treat a low-density electron system with a dielectric catastrophe. If it is applied to semiconductors and insulators, we find that the obtained quasiparticle dispersion is virtually the same as that in the one-shot $G W$ approximation (or $G_{0} W_{0}$ A), indicating that the $G_{0} W_{0}$ A actually takes proper account of both vertex and high-order self-energy corrections in a mutually cancelling manner.

arXiv comment4 pages, 2 figures

Improvement on the GWΓ Scheme for the Electron Self-Energy and Relevance of the G0​W0​ Approximation from this Perspective

Abstract

Improvement on the GW $Γ$ Scheme for the Electron Self-Energy and Relevance of the $G_{0} W_{0}$ Approximation from this Perspective