Multibands Tunneling in AAA-Stacked Trilayer Graphene

TL;DR

This paper investigates electronic tunneling in AAA-stacked trilayer graphene, revealing unique chiral quasiparticles, multiple Dirac cones, and perfect transmission phenomena, with implications for graphene-based electronic devices.

Contribution

It provides a detailed analysis of tunneling and conductance in AAA-stacked trilayer graphene, highlighting the role of multiple Dirac cones and cone index in transport properties.

Findings

Perfect transmission at normal incidence due to Klein tunneling

Presence of three Dirac cones with distinct chirality indexes

Comparison showing differences with ABA- and ABC-stacked graphene

Abstract

We study the electronic transport through np and npn junctions for AAA-stacked trilayer graphene. Two kinds of gates are considered where the first is a single gate and the second is a double gate. After obtaining the solutions for the energy spectrum, we use the transfer matrix method to determine the three transmission probabilities for each individual cone $\tau=0, \pm 1$. We show that the quasiparticles in AAA-stacked trilayer graphene are not only chiral but also labeled by an additional cone index $\tau$. The obtained bands are composed of three Dirac cones that depend on the chirality indexes. We show that there is perfect transmission for normal or near normal incidence, which is a manifestation of the Klein tunneling effect. We analyze also the corresponding total conductance, which is defined as the sum of the conductance channels in each individual cone. Our results are numerically discussed and compared with those obtained for ABA- and ABC-stacked trilayer graphene.