Probing electronic excitations in mono- to pentalayer graphene by micro-magneto-Raman spectroscopy

TL;DR

This study uses micro-magneto Raman spectroscopy to investigate electronic excitations in multilayer graphene, revealing band evolution consistent with a bilayer model and highlighting potential for exploring quantum Hall phenomena.

Contribution

It demonstrates a novel application of micro-magneto Raman spectroscopy to analyze electronic excitations in multilayer graphene with high spatial and spectral resolution.

Findings

Electronic excitations follow a simple bilayer model

Band evolution observed in up to five layers

Method enables minimally-invasive studies of low-dimensional systems

Abstract

We probe electronic excitations between Landau levels in freestanding $N-$layer graphene over a broad energy range, with unprecedented spectral and spatial resolution, using micro-magneto Raman scattering spectroscopy. A characteristic evolution of electronic bands in up to five Bernal-stacked graphene layers is evidenced and shown to remarkably follow a simple theoretical approach, based on an effective bilayer model. $(N>3)$-layer graphene appear as appealing candidates in the quest for novel phenomena, particularly in the quantum Hall effect regime. Our work paves the way towards minimally-invasive investigations of magneto-excitons in other emerging low-dimensional systems, with a spatial resolution down to 1$~\mu$m.