Anomalous Enhancement of the Boltzmann Conductivity in Disordered Zigzag Graphene Nanoribbons

Abstract

We study the conductivity of disordered zigzag graphene nanoribbons in the incoherent regime by using the Boltzmann equation approach. The band structure of zigzag nanoribbons contains two energy valleys, and each valley has an excess one-way channel. The crucial point is that the numbers of conducting channels for two propagating directions are imbalanced in each valley due to the presence of an excess one-way channel. It was pointed out that as a consequence of this imbalance, a perfectly conducting channel is stabilized in the coherent regime if intervalley scattering is absent. We show that even in the incoherent regime, the conductivity is anomalously enhanced if intervalley scattering is very weak. Particularly, in the limit of no intervalley scattering, the dimensionless conductance approaches to unity with increasing ribbon length as if there exists a perfectly conducting channel. We also show that anomalous valley polarization of electron density appears in the presence of an electric field.

10 pages, 3 figures

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Cited by in corpus (6)

• Edge scattering of electrons in graphene
• Quantum Interference Effects in Topological Nanowires In a Longitudinal Magnetic Field
• Theoretical study of scattering in graphene ribbons in the presence of structural and atomistic edge roughness
• Dephasing-Induced Stabilization of a Perfectly Conducting Channel in Disordered Graphene Nanoribbons with Zigzag Edges
• Perfectly conducting channel and its robustness in disordered carbon nanostructures
• Nonuniversal Shot Noise in Disordered Quantum Wires with Channel-Number Imbalance