Topological Metal-Insulator Transition in Narrow Graphene Nanoribbons?

15 June 2020, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

We show that very narrow armchair graphene nanoribbons (AGNRs) of length L and width of 2 zigzag-rings undergo a metal-insulator-like transition at a critical length of 10nm, where the energy gap drops rather abruptly, and the conductivity, estimated, through an invoked computational scheme, rises almost discontinuously to a value between that of a perfect quasi one-dimensional system, and the nominal minimum conductivity of graphene. At this length, the aromatic and non-aromatic rings are interchanged, and sharp peaks appear in the density of states around the Fermi level, suggesting metallic-like behaviour. Such peaks linked to edge states at the Dirac point(s) coincide with the charge-neutrality point(s), associated with the minimum conductivity of graphene. Thus, we have an uncommon combination of interrelated “short-long”, “core-edge,” topological-aromatic transition(s) due to strong quantum confinement, driven by inversion symmetry conflict. The bandgap decreases with the 2/3 power of length before the “transition” and logarithmically afterwards. These effects are practically non-existent for wider AGNRs

Keywords

Graphene nanoribbons
armchair graphene nanoribbon
Metal-Insulator Transition
Graphene

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.