Gate-induced interlayer asymmetry in ABA-stacked trilayer graphene

TL;DR

This paper investigates how external gating affects the electronic band structure of ABA-stacked trilayer graphene, revealing unique band hybridization and conductivity behavior due to interlayer asymmetry.

Contribution

It provides a self-consistent theoretical analysis of gate-induced interlayer asymmetry and its effects on electronic properties in trilayer graphene.

Findings

Gate field breaks mirror symmetry and hybridizes bands.

Density of states and conductivity increase with gate strength.

Distinct behavior from bilayer graphene under gating.

Abstract

We calculate the electronic band structure of ABA-stacked trilayer graphene in the presence of external gates, using a self-consistent Hartree approximation to take account of screening. In the absence of a gate potential, there are separate pairs of linear and parabolic bands at low energy. A gate field perpendicular to the layers breaks mirror reflection symmetry with respect to the central layer and hybridizes the linear and parabolic low-energy bands, leaving a chiral Hamiltonian essentially different from that of monolayer or bilayer graphene. Using the self-consistent Born approximation, we find that the density of states and the minimal conductivity in the presence of disorder generally increase as the gate field increases, in sharp contrast with bilayer graphene.