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The effect of magnetic field and disorders on the electronic transport in graphene nanoribbons.

Journal of physics. Condensed matter : an Institute of Physics journal · 2010 · Mixed · Insufficient evidence

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MixedInsufficient evidencePaper 3293

Using a mesoscopic transport model (NEGF with a real-space π-orbital model), the authors report that a uniform perpendicular magnetic field produces distinct spatial current profiles in perfect armchair graphene nanoribbons depending on ribbon width. Under ap…

Study snapshot

PublicationJournal of physics. Condensed matter : an Institute of Physics journal · 2010
Study typeother
Reported directionMixed
Evidence ratingInsufficient

Abstract

We developed a unified mesoscopic transport model for graphene nanoribbons, which combines the nonequilibrium Green's function (NEGF) formalism with the real-space π-orbital model. Based on this model, we probe the spatial distribution of electrons under a magnetic field, in order to obtain insights into the various signature Hall effects in disordered armchair graphene nanoribbons (AGNR). In the presence of a uniform perpendicular magnetic field (B[Symbol: see text]-field), a perfect AGNR shows three distinct spatial current profiles at equilibrium, depending on its width. Under nonequilibrium conditions (i.e. in the presence of an applied bias), the net electron flow is restricted to the edges and occurs in opposite directions depending on whether the Fermi level lies within the valence or conduction band. For electrons at an energy level below the conduction window, the B[Symbol: see text]-field gives rise to local electron flux circulation, although the global flux is zero. Our study also reveals the suppression of electron backscattering as a result of the edge transport which is induced by the B[Symbol: see text]-field. This phenomenon can potentially mitigate the undesired effects of disorder, such as bulk and edge vacancies, on the transport properties of AGNR. Lastly, we show that the effect of [Formula: see text]-field on electronic transport is less significant in the multimode compared to the single-mode electron transport.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother
Effect directionmixed
PopulationNot supplied
Sample sizeNot supplied
ExposureNot supplied
Evidence strengthInsufficientConfidence: 78% · Peer reviewed: yes

Main findings

Using a mesoscopic transport model (NEGF with a real-space π-orbital model), the authors report that a uniform perpendicular magnetic field produces distinct spatial current profiles in perfect armchair graphene nanoribbons depending on ribbon width. Under applied bias, net electron flow is restricted to edges with direction depending on whether the Fermi level is in the valence or conduction band; for energies below the conduction window, local flux circulation occurs with zero global flux. The magnetic-field-induced edge transport is reported to suppress electron backscattering and may mitigate disorder-related effects; the magnetic-field effect is described as less significant in multimode than single-mode transport.

Outcomes measured

  • Electronic transport in graphene nanoribbons
  • Spatial current profiles / electron flow distribution
  • Electron backscattering
  • Effects of disorder (bulk and edge vacancies) on transport

Limitations

  • Modeling/theoretical study; no experimental or human/animal data described in the abstract
  • Magnetic field strength and other exposure parameters are not specified in the abstract
  • Outcomes are electronic transport properties in graphene nanoribbons, not health endpoints
View raw extracted JSON
{
  "study_type": "other",
  "exposure": {
    "band": null,
    "source": "magnetic field (uniform perpendicular)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Electronic transport in graphene nanoribbons",
    "Spatial current profiles / electron flow distribution",
    "Electron backscattering",
    "Effects of disorder (bulk and edge vacancies) on transport"
  ],
  "main_findings": "Using a mesoscopic transport model (NEGF with a real-space π-orbital model), the authors report that a uniform perpendicular magnetic field produces distinct spatial current profiles in perfect armchair graphene nanoribbons depending on ribbon width. Under applied bias, net electron flow is restricted to edges with direction depending on whether the Fermi level is in the valence or conduction band; for energies below the conduction window, local flux circulation occurs with zero global flux. The magnetic-field-induced edge transport is reported to suppress electron backscattering and may mitigate disorder-related effects; the magnetic-field effect is described as less significant in multimode than single-mode transport.",
  "effect_direction": "mixed",
  "limitations": [
    "Modeling/theoretical study; no experimental or human/animal data described in the abstract",
    "Magnetic field strength and other exposure parameters are not specified in the abstract",
    "Outcomes are electronic transport properties in graphene nanoribbons, not health endpoints"
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "graphene nanoribbons",
    "armchair graphene nanoribbons",
    "magnetic field",
    "Hall effects",
    "nonequilibrium Green's function",
    "edge transport",
    "disorder",
    "backscattering"
  ],
  "suggested_hubs": []
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1088/0953-8984/22/37/375303
PubMed: 21403192

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