Resonant transport in Kekule-distorted graphene nanoribbons

TL;DR

This paper investigates how Kekulé distortions in graphene nanoribbons affect their electronic bandstructure and transport properties, revealing resonant tunneling phenomena that could enable measurement of Kekule9 parameters.

Contribution

It provides the first detailed analysis of resonant transport in Kekule9-distorted graphene nanoribbons, linking superlattice effects to conductance resonances.

Findings

Resonant conductance peaks emerge in energy gap regions.

Resonance strength scales with the number of Kek-Y interfaces.

Kekule9 distortions can be used to measure their own strength.

Abstract

The formation of a superlattice in graphene can serve as a way to modify its electronic bandstructure and thus to engineer its electronic transport properties. Recent experiments have discovered a Kekul\'e bond ordering in graphene deposited on top of a Copper substrate, leading to the breaking of the valley degeneracy while preserving the highly desirable feature of linearity and gapless character of its band dispersion. In this paper we study the effects of a Kekul\'e distortion in zigzag graphene nanoribbons in both, the subband spectrum and on its electronic transport properties. We extend our study to investigate also the electronic conductance in graphene nanoribbons composed of sequentially ordered Kek-Y superlattice. We find interesting resonances in the conductance response emerging in the otherwise energy gap regions, which scales with the number of Kek-Y interfaces minus one. Such features resembles the physics of resonant tunneling behavior observed in semiconductors heterostructures. Our findings provide a possible way to measure the strenght of Kekul\'e parameter in graphene nanoribbons.