Resonant tunneling through double-barrier structures on graphene

TL;DR

This paper investigates quantum resonant tunneling in double-barrier graphene structures, showing how tunneling behaviors change with barrier height and boundary conditions, bridging Dirac and Schrödinger transport regimes.

Contribution

It provides a detailed analysis of resonant tunneling phenomena in graphene double barriers, including the transition from Klein to Schrödinger-like behavior and boundary condition effects.

Findings

Klein tunneling vanishes for barrier heights above 300 meV.

Resonant tunneling peaks align with graphene nanoribbon eigenlevels.

Differences between zigzag and armchair edge barriers are characterized.

Abstract

Quantum resonant tunneling behaviors of double-barrier structures on graphene are investigated under the tight-binding approximation. The Klein tunneling and resonant tunneling are demonstrated for the quasiparticles with energy close to the Dirac points. The Klein tunneling vanishes by increasing the height of the potential barriers to more than 300 meV. The Dirac transport properties continuously change to the Schrodinger ones. It is found that the peaks of resonant tunneling approximate to the eigen-levels of graphene nanoribbons under appropriate boundary conditions. A comparison between the zigzag- and armchair-edge barriers is given.