Detection of Interlayer Interaction in Few-layer Graphene through Landau Level Spectroscopy

TL;DR

This study uses Landau level spectroscopy to reveal surface relaxation and interlayer interaction differences in Bernal-stacked few-layer graphene, highlighting the significance of interlayer coupling in electronic properties.

Contribution

It provides direct experimental evidence of surface relaxation phenomena in tetralayer graphene through quantum capacitance measurements.

Findings

Surface relaxation appears in tetralayer but not trilayer graphene.

Interlayer hopping parameters differ significantly between trilayer and tetralayer graphene.

Interlayer interactions influence symmetry-breaking effects in graphene.

Abstract

We demonstrate that surface relaxation, which is insignificant in trilayer graphene, starts to manifest in Bernal-stacked tetralayer graphene. Bernal-stacked few-layer graphene has been investigated by analyzing its Landau level spectra through quantum capacitance measurements. We find that in trilayer graphene, the interlayer interaction parameters were similar to that of graphite. However, in tetralayer graphene, the hopping parameters between the bulk and surface bilayers are quite different. This shows a direct evidence for the surface relaxation phenomena. In spite of the fact that the Van der Waals interaction between the carbon layers is thought to be insignificant, we suggest that the interlayer interaction is an important factor in explaining the observed results and the symmetry-breaking effects in graphene sublattice are not negligible.