Magneto-Raman scattering of graphene on graphite: Electronic and phonon excitations

TL;DR

This study uses magneto-Raman scattering to explore electronic and phonon excitations in graphene on graphite, revealing new hybridization phenomena and selection rules, with implications for quantum Hall effect research.

Contribution

It demonstrates the first observation of hybrid phonon-electronic excitations and domain-specific Raman features in graphene on graphite under high magnetic fields.

Findings

Identification of graphene and graphite domains via Raman imaging.

Observation of hybrid phonon-electronic excitations.

Elucidation of polarization-dependent selection rules.

Abstract

Magneto-Raman scattering experiments from the surface of graphite reveal novel features associated to purely electronic excitations which are observed in addition to phonon-mediated resonances. Graphene-like and graphite domains are identified through experiments with $\sim 1\mu m$ spatial resolution performed in magnetic fields up to 32T. Polarization resolved measurements emphasize the characteristic selection rules for electronic transitions in graphene. Graphene on graphite displays the unexpected hybridization between optical phonon and symmetric across the Dirac point inter Landau level transitions. The results open new experimental possibilities - to use light scattering methods in studies of graphene under quantum Hall effect conditions.