Conductance across strain junctions in graphene nanoribbons

TL;DR

This study investigates how strain junctions in graphene nanoribbons affect electronic conductance, demonstrating that the strain-induced transport gap remains robust despite disorder and interface smoothness variations.

Contribution

The paper provides a numerical analysis showing the robustness of the strain-induced transport gap in graphene nanoribbons under realistic conditions, including disorder and interface smoothness.

Findings

Smooth and sharp strain barriers similarly suppress low-density conductance.

Transport gap robustness is unaffected by interface inhomogeneity and work function mismatch.

Critical transmission onset depends on strain orientation relative to the ribbon.

Abstract

To address the robustness of the transport gap induced by locally strained regions in graphene nanostructures, the effect of disorder and smoothness of the interface region is investigated within the Landauer-B\"uttiker formalism. The electronic conductance across strained junctions and barriers in graphene nanoribbons is calculated numerically, with and without various types of disorder, and comparing smooth and sharp strain junctions. A smooth strain barrier in graphene is seen to be generically as efficient in suppressing transport at low densities as a sharp one, and the critical density (or energy) for the onset of transmission depends on the strain orientation with respect to the ribbon. In addition, hopping (or strain) inhomogeneity and work function mismatch at the interface region do not visibly degrade the transport gap. These results show that the strain-induced transport gap at a strain junction is robust to more realistic strain conditions.