Engineering Delocalization in Graphene Nanoribbons via Quasiperiodic Edges and Electronic Interactions

TL;DR

This study explores how quasiperiodic edges and electron interactions in graphene nanoribbons influence electronic localization and transport, revealing tunable regimes from localization to delocalization.

Contribution

It introduces a combined model of quasiperiodic geometry and electronic interactions to control transport regimes in graphene nanoribbons.

Findings

Non-interacting case shows geometric localization.

Weak interactions induce oscillatory transmission and delocalization.

Strong interactions lead to re-localization due to repulsion.

Abstract

We investigate localization effects in zigzag graphene nanoribbons with quasiperiodic Fibonacci-type edge extensions, accounting for electron-electron interactions. We employ a tight-binding model that includes first- and third-nearest-neighbor hoppings, in which electronic interactions are treated within a self-consistent mean-field Hubbard approximation. Charge transport properties are calculated using the Landauer-B\"uttiker formalism. Our results reveal that the combination of quasiperiodic geometry and electronic interactions gives rise to nontrivial transport phenomena. Specifically, the system exhibits three transport regimes: in the non-interacting case, we observe geometric localization. For weak interactions, the system shows a conductive regime with transmission oscillations, whose multiplicity increases with the Fibonacci generation order. In this regime, delocalization emerges from the interplay between geometry and interaction-induced correlations. Finally, for strong interactions, repulsion dominates, and the system returns to a localized state. Our results demonstrate that quasiperiodic edge engineering, combined with electronic interaction control, offers a promising path to modulate transport in graphene nanoribbons.