Klein tunneling through an oblique barrier in graphene ribbons

TL;DR

This paper investigates how an oblique top gate barrier affects electron transmission in graphene nanoribbons, revealing unique transmission patterns influenced by the ribbon's electronic structure.

Contribution

It introduces a Green function approach to analyze mode scattering in graphene ribbons with oblique barriers, highlighting differences from 2D graphene.

Findings

Transmission patterns depend on the electronic structure of the ribbon.

Irregular transmission features are predicted due to mode scattering.

Perfect transmission occurs in metallic ribbons regardless of barrier angle and length.

Abstract

We study a transmission coefficient of graphene nanoribbons with a top gate which acts as an oblique barrier. Using a Green function method based on the Dirac-like equation, scattering among transverse modes due to the oblique barrier is taken into account numerically. In contrast to the 2-dimensional graphene sheet, we find that the pattern of transmission in graphene ribbons depends strongly on the electronic structure in the region of the barrier. Consequently, irregular structures in the transmission coefficient are predicted while perfect transmission is still calculated in the case of metallic graphene independently of angle and length of the oblique barrier.