# Ab initio calculation of the $G$ peak intensity of graphene: Combined study of the laser and Fermi energy dependence and importance of quantum interference effects

## TL;DR

This study uses ab initio calculations to analyze the $G$ peak intensity in graphene, highlighting the roles of quantum interference and non-resonant states across various laser and Fermi energies.

## Contribution

It introduces a general, ab initio approach that surpasses previous analytical models, emphasizing quantum interference effects in the $G$ peak of graphene.

## Key findings

- Quantum interference significantly affects the $G$ peak intensity.
- Non-resonant electronic states contribute notably to the $G$ peak.
- Methodology is applicable to other materials.

## Abstract

We present the results of a diagrammatic, fully ab initio calculation of the $G$ peak intensity of graphene. The flexibility and generality of our approach enables us to go beyond the previous analytical calculations in the low-energy regime. We study the laser and Fermi energy dependence of the $G$ peak intensity and analyze the contributions from resonant and non-resonant electronic transitions. In particular, we explicitly demonstrate the importance of quantum interference and non-resonant states for the $G$ peak process. Our method of analysis and computational concept is completely general and can easily be applied to study other materials as well.