Gate dependent electronic Raman scattering in graphene

TL;DR

This paper demonstrates polarization-resolved electronic Raman scattering in gated graphene, revealing how the spectra evolve with gate voltage and polarization, aligning with theoretical models of Dirac fermion excitations.

Contribution

It provides the first direct observation of polarization-resolved electronic Raman scattering in graphene and links spectral features to the dynamical polarizability of Dirac fermions.

Findings

Spectra depend on gate voltage and polarization

Spectral features match theoretical predictions

Electronic Raman scattering probes Dirac fermion excitations

Abstract

We report the direct observation of polarization resolved electronic Raman scattering in a gated monolayer graphene device. The evolution of the electronic Raman scattering spectra with gate voltage and its polarization dependence are in full agreement with theoretical expectations for non-resonant Raman processes involving interband electron-hole excitations across the Dirac cone. We further show that the spectral dependence of the electronic Raman scattering signal can be simply described by the dynamical polarizability of graphene in the long wavelength limit. The possibility to directly observe Dirac fermion excitations in graphene opens the way to promising Raman investigations of electronic properties of graphene and other 2D crystals.