Electronic Band gaps and transport properties inside graphene superlattices with one-dimensional periodic squared potentials

TL;DR

This paper investigates the electronic band structure and transport properties of graphene superlattices with one-dimensional periodic squared potentials, revealing the formation of a robust new Dirac point and associated energy gaps.

Contribution

It introduces the concept of a new Dirac point in graphene superlattices and analyzes its robustness against structural variations and disorder.

Findings

A new Dirac point forms at the zero-averaged wavenumber energy

The Dirac point location depends only on potential width ratios

The zero-averaged wavenumber gap is insensitive to lattice variations and disorder

Abstract

The electronic transport properties and band structures for the graphene-based one-dimensional (1D) superlattices with periodic squared potentials are investigated. It is found that a new Dirac point is formed, which is exactly located at the energy which corresponds to the zero (volume) averaged wavenumber inside the 1D periodic potentials. The location of such a new Dirac point is robust against variations in the lattice constants, and it is only dependent on the ratio of potential widths. The zero-averaged wavenumber gap associated with the new Dirac point is insensitive to both the lattice constant and the structural disorder, and the defect mode in the zero-averaged wavenumber gap is weakly dependent on the insident angles of carriers.