Quantum Hall Effect and Semimetallic Behavior of Dual-Gated ABA-Stacked Trilayer Graphene

TL;DR

This study investigates the electronic transport properties of ABA-stacked trilayer graphene, revealing its semimetallic behavior and unique quantum Hall effects under dual-gate control, distinct from monolayer and bilayer graphene.

Contribution

It provides new insights into the electronic structure and quantum Hall phenomena of ABA-stacked trilayer graphene under electric fields.

Findings

Distinct quantum Hall effects compared to monolayer and bilayer graphene

Observation of electron-hole asymmetry indicating semimetallic band overlap

Landau level splittings due to valley degeneracy lifting under electric field

Abstract

The electronic structure of multilayer graphenes depends strongly on the number of layers as well as the stacking order. Here we explore the electronic transport of purely ABA-stacked trilayer graphenes in a dual-gated field-effect device configuration. We find that both the zero-magnetic-field transport and the quantum Hall effect at high magnetic fields are distinctly different from the monolayer and bilayer graphenes, and that they show electron-hole asymmetries that are strongly suggestive of a semimetallic band overlap. When the ABA trilayers are subjected to an electric field perpendicular to the sheet, Landau level splittings due to a lifting of the valley degeneracy are clearly observed.