Electrically Induced Dirac Fermions in Graphene Nanoribbons

Abstract

Graphene nanoribbons are widely regarded as promising building blocks for next-generation carbon-based devices. A critical issue to their prospective applications is whether and to what degree their electronic structure can be externally controlled. Here, we combine simple model Hamiltonians with extensive first-principles calculations to investigate the response of armchair graphene nanoribbons to transverse electric fields. Such fields can be achieved either upon laterally gating the nanoribbon or incorporating ambipolar chemical co-dopants along the edges. We reveal that the field induces a semiconductor-to-semimetal transition, with the semimetallic phase featuring zero-energy Dirac fermions that propagate along the armchair edges. The transition occurs at critical fields that scale inversely with the width of the nanoribbons. These findings are universal to group-IV honeycomb lattices, including silicene and germanene nanoribbons, irrespective of the type of edge termination. Overall, our results create new opportunities to electrically engineer Dirac fermions in otherwise semiconducting graphene-like nanoribbons.

References in corpus (12)

• Energy Gaps in Graphene Nanoribbons
• Half-Metallic Graphene Nanoribbons
• Electronic States of Graphene Nanoribbons
• Will Zigzag Graphene Nanoribbon Turn to Half Metal under Electric Field?
• Armchair graphene nanoribbons: Electronic structure and electric field modulation
• Probing the magnetism of topological end-states in 5-armchair graphene nanoribbons
• Substrate transfer and ex situ characterization of on-surface synthesized graphene nanoribbons
• Structure-dependent electrical properties of graphene nanoribbon devices with graphene electrodes
• Transverse field effect in graphene ribbons
• Electric Field Tunable Topological Phases in Graphene Nanoribbons
• Silicene nanoribbons on an insulating thin film
• Imprinting Tunable $\pi$-Magnetism in Graphene Nanoribbons via Edge Extensions

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