Klein tunneling through triple barrier in AB bilayer graphene

TL;DR

This paper studies electron transport through a triple electrostatic barrier in AB bilayer graphene, revealing how barrier width, energy, and interlayer potential differences affect transmission, resonance, and conductance.

Contribution

It introduces a detailed analysis of triple barrier effects in AB bilayer graphene, including resonance phenomena and conductance features, extending previous single and double barrier studies.

Findings

Complete suppression of transmission in the gap at normal incidence for large barriers.

Resonance in transmission channels unique to triple barrier configurations.

Number of conductance peaks exceeds that of double barrier systems.

Abstract

We investigate the transport properties of charge carriers in AB bilayer graphene through a triple electrostatic barrier. We calculate the transmission and reflection using the continuity conditions at the interfaces of the triple barrier together with the transfer matrix method. First, we consider the case where the energy is less than the interlayer coupling $\gamma_1$ and show that, at normal incidence, transmission is completely suppressed in the gap for a large barrier width while it appears in the gap for a small barrier width. For energies greater than $\gamma_1$, we show that in the absence of an interlayer potential difference, transmission is less than that of a single barrier, but in its presence, transmission in the gap region is suppressed, as opposed to a double barrier. It is found that one, two, or three gaps can be created depending on the number of interlayer potential differences applied. Resonance in the $T_-^+$ transmission channel is observed that is not seen in the single and double barrier cases. Finally, we compute the conductance and show that the number of peaks is greater than the double barrier case.