High- and low-energy many-body effects of graphene in a unified approach

Fuente: arXiv
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Auteurs principaux: Guandalini, Alberto, Caldarelli, Giovanni, Macheda, Francesco, Mauri, Francesco
Format: Preprint
Publié: 2024
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author Guandalini, Alberto
Caldarelli, Giovanni
Macheda, Francesco
Mauri, Francesco
author_facet Guandalini, Alberto
Caldarelli, Giovanni
Macheda, Francesco
Mauri, Francesco
contents We show that the many-body features of graphene band structure and electronic response can be accurately evaluated by applying many-body perturbation theory to a tight-binding (TB) model. In particular, we compare TB results for the optical conductivity with previous ab-initio calculations, showing a nearly perfect agreement both in the low energy region near the Dirac cone ($\sim 100$ meV), and at the higher energies of the π plasmon ($\sim 5$ eV). A reasonable agreement is reached also for the density-density response at the Brillouin zone corner. With the help of the reduced computational cost of the TB model, we study the effect of self-consistency on the screened interaction (W) and on the quasi-particle corrections, a task that is not yet achievable in ab-initio frameworks. We find that self-consistency is important to reproduce the experimental results on the divergence of the Fermi velocity, while it marginally affects the optical conductivity. Finally, we study the robustness of our results against doping or the introduction of a uniform dielectric environment.
format Preprint
id arxiv_https___arxiv_org_abs_2409_17645
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle High- and low-energy many-body effects of graphene in a unified approach
Guandalini, Alberto
Caldarelli, Giovanni
Macheda, Francesco
Mauri, Francesco
Atomic and Molecular Clusters
We show that the many-body features of graphene band structure and electronic response can be accurately evaluated by applying many-body perturbation theory to a tight-binding (TB) model. In particular, we compare TB results for the optical conductivity with previous ab-initio calculations, showing a nearly perfect agreement both in the low energy region near the Dirac cone ($\sim 100$ meV), and at the higher energies of the π plasmon ($\sim 5$ eV). A reasonable agreement is reached also for the density-density response at the Brillouin zone corner. With the help of the reduced computational cost of the TB model, we study the effect of self-consistency on the screened interaction (W) and on the quasi-particle corrections, a task that is not yet achievable in ab-initio frameworks. We find that self-consistency is important to reproduce the experimental results on the divergence of the Fermi velocity, while it marginally affects the optical conductivity. Finally, we study the robustness of our results against doping or the introduction of a uniform dielectric environment.
title High- and low-energy many-body effects of graphene in a unified approach
topic Atomic and Molecular Clusters
url https://arxiv.org/abs/2409.17645