Circular dichroism of magneto-phonon resonance in doped graphene

TL;DR

This study investigates the polarization-dependent Raman response of doped graphene in high magnetic fields, revealing selective hybridization of phonons with Landau level excitations and inherent polarization anisotropy.

Contribution

It demonstrates the polarization anisotropy of magneto-phonon resonance in doped graphene and identifies the specific hybridization with the fundamental Landau level excitation.

Findings

Hybridization of E$_{2g}$ phonon with n=0 Landau level observed.

Polarization anisotropy is inherent to doped graphene samples.

Selective hybridization occurs only in one polarization configuration.

Abstract

Polarization resolved, Raman scattering response due to E$_{2g}$ phonon in monolayer graphene has been investigated in magnetic fields up to 29 T. The hybridization of the E$_{2g}$ phonon with only the fundamental inter Landau level excitation (involving the n=0 Landau level) is observed and only in one of the two configurations of the circularly crossed polarized excitation and scattered light. This polarization anisotropy of the magneto-phonon resonance is shown to be inherent to relatively strongly doped graphene samples, with carrier concentration typical for graphene deposited on SiO$_2$.