2024/09/26 by Alberto Guandalini, Giovanni Caldarelli, Guandalini, Alberto +5 · 1 citation
Chemistry · Materials Science · #Atomic and Molecular Clusters (physics.atm-clus) #Diamond and Carbon-based Materials Research #FOS: Physical sciences #Fullerene Chemistry and Applications #Graphene research and applications
paper · pdf · doi:10.48550/arxiv.2409.17645
openalex publication_date 2024/09/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 (∼ 100 meV), and at the higher energies of the π plasmon (∼ 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.