Interfaces Within Graphene Nanoribbons

Abstract

We study the conductance through two types of graphene nanostructures: nanoribbon junctions in which the width changes from wide to narrow, and curved nanoribbons. In the wide-narrow structures, substantial reflection occurs from the wide-narrow interface, in contrast to the behavior of the much studied electron gas waveguides. In the curved nanoribbons, the conductance is very sensitive to details such as whether regions of a semiconducting armchair nanoribbon are included in the curved structure -- such regions strongly suppress the conductance. Surprisingly, this suppression is not due to the band gap of the semiconducting nanoribbon, but is linked to the valley degree of freedom. Though we study these effects in the simplest contexts, they can be expected to occur for more complicated structures, and we show results for rings as well. We conclude that experience from electron gas waveguides does not carry over to graphene nanostructures. The interior interfaces causing extra scattering result from the extra effective degrees of freedom of the graphene structure, namely the valley and sublattice pseudospins.

19 pages, published version, several references added, small changes to conclusions

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Cited by in corpus (19)

• WKB analysis of edge states in graphene in a strong magnetic field
• Edge effects in graphene nanostructures: I. From multiple reflection expansion to density of states
• Armchair graphene nanoribbons: PT-symmetry breaking and exceptional points without dissipation
• Sensory Organ like Response of Zigzag Edge Graphene Nanoribbons
• High-performance solution of the transport problem in a graphene armchair structure with a generic potential
• An epitaxial graphene platform for zero-energy edge state nanoelectronics
• Sensory organ like response determines the magnetism of zigzag-edged honeycomb nanoribbons
• Impurity and edge roughness scattering in armchair graphene nanoribbons: Boltzmann approach
• Coherent transport of armchair graphene constrictions
• Decomposition into Propagating and Evanescent Modes of Graphene Ribbons
• Quantized electron transport through graphene nanoconstrictions
• Conductance response of graphene nanoribbons and quantum point contacts in the scanning probe measurements
• Nonlinear conductance quantization in graphene ribbons
• Coherent Transport in Y-Junction Graphene Waveguide
• Scanning gate microscopy in graphene nanostructures
• Time-Reversal Symmetry Breaking and Decoherence in Chaotic Dirac Billiards
• Fabry-Perot and Aharonov-Bohm interference in ideal graphene nanoribbons
• Conditions for Conductance Quantization in Mesoscopic Dirac Systems on the Examples of Graphene Nanoconstrictions
• Edge channels in a graphene Fabry-Perot interferometer