Tunneling of Electrons in Graphene via Double Triangular Barrier in External Fields

TL;DR

This paper investigates how Dirac fermions in graphene transmit through a double triangular barrier under external magnetic fields, revealing oscillation resonances and the influence of electrostatic fields on tunneling behavior.

Contribution

It provides a detailed analysis of transmission and reflection coefficients for graphene under complex potential barriers, highlighting control mechanisms for tunneling resistance.

Findings

Transmission exhibits oscillation resonances due to Klein tunneling.

Electrostatic fields control tunneling resistance peaks.

Klein paradox remains unaffected at normal incidence.

Abstract

We study the transmission probability of Dirac fermions in graphene scattered by a triangular double barrier potential in the presence of an external magnetic field. Our system made of two triangular potential barrier regions separated by a well region characterized by an energy gap. Solving our Dirac-like equation and matching the solutions at the boundaries allowed us to express our transmission and reflection coefficients in terms of transfer matrix. We show in particular that the transmission exhibits oscillation resonances that are manifestations of the Klein tunneling effect. The triangular barrier electrostatic field was found to play a key role in controlling the peak of tunneling resistance. However, it only slightly modifies the resonances at oblique incidence and leaves Klein paradox unaffected at normal incidence.