Improvement on the GWΓ Scheme for the Electron Self-Energy and Relevance of the G₀W₀ Approximation from this Perspective

2010/03/17 by Soh Ishii, Ishii, Soh, Hideaki Maebashi +3
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Electron and X-Ray Spectroscopy Techniques #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Surface and Thin Film Phenomena

paper · pdf · doi:10.48550/arxiv.1003.3342

openalex publication_date 2010/03/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

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 GW approximation (or G₀W₀A), indicating that the G₀W₀A actually takes proper account of both vertex and high-order self-energy corrections in a mutually cancelling manner.

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