Multiphonons resonance Raman scattering in Landau-quantized graphene

TL;DR

This paper presents a theoretical study of multiphonon resonance Raman scattering in Landau-quantized graphene, introducing a new combined multiphonons scattering model that explains spectral features under magnetic fields.

Contribution

It proposes the combined multiphonons scattering (CMS) model, integrating surface optical and acoustic phonons, to better understand Raman spectra in graphene under magnetic fields.

Findings

CMS exhibits a blue-shift with increasing magnetic field.

The model explains the shoulder features in Raman spectra.

Potential to analyze fine spectral structures in 2D materials.

Abstract

We theoretically investigate multiphonons resonance Raman scattering between the Landau levels in graphene on the polar substrate using the Huang-Rhys's model. We not only present the single and multiple surface optical (SO) phonons scattering, but also propose the combined multiphonons scattering (CMS), which is composed of the SO phonon and longitudinal acoustic phonon. We find that the CMS has a blue-shift behavior with increasing the magnetic field, differing from these SO phonon resonance scattering at a special magnetic field. This behavior may be used to explain the changing shoulder of the Raman spectrum of optical phonon resonance scattering in experiments. The theoretical model could be expanded to analyze the fine structure of Raman spectrum in two-dimensional materials.