RF Safe

Spin current pumped by a rotating magnetic field in zigzag graphene nanoribbons.

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

← Research stream
UnclearInsufficient evidencePaper 3289

Using a nonequilibrium Green's function approach in a rotating reference frame, the authors derive spin-resolved pumped current in zigzag graphene nanoribbons under a transverse rotating magnetic field without applied bias. Pumped spin current density increas…

Study snapshot

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

Abstract

We study electron spin resonance in zigzag graphene nanoribbons by applying a rotating magnetic field on the system without any bias. By using the nonequilibrium Green's function technique, the spin-resolved pumped current is explicitly derived in a rotating reference frame. The pumped spin current density increases with the system size and the intensity of the transverse rotating magnetic field. For graphene nanoribbons with an even number of zigzag chains, there is a nonzero pumped charge current in addition to the pumped spin current owing to the broken spatial inversion symmetry of the system, but its magnitude is much smaller than the spin current. The short-ranged static disorder from either impurities or defects in the ribbon can depress the spin current greatly due to the localization effect, whereas the long-ranged disorder from charge impurities can avoid inter-valley scattering so that the spin current can survive in the strong disorder for the single-energy mode.

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 directionunclear
PopulationNot supplied
Sample sizeNot supplied
ExposureNot supplied
Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

Using a nonequilibrium Green's function approach in a rotating reference frame, the authors derive spin-resolved pumped current in zigzag graphene nanoribbons under a transverse rotating magnetic field without applied bias. Pumped spin current density increases with system size and with the intensity of the transverse rotating magnetic field. For ribbons with an even number of zigzag chains, a nonzero pumped charge current is also predicted due to broken spatial inversion symmetry, but it is much smaller than the spin current; short-ranged static disorder can greatly depress the spin current, while long-ranged charge-impurity disorder can allow the spin current to survive in strong disorder for a single-energy mode.

Outcomes measured

  • spin-resolved pumped current
  • pumped spin current density
  • pumped charge current
  • effects of static disorder (impurities/defects) on spin current
  • effects of long-ranged charge-impurity disorder on spin current

Limitations

  • Appears to be a theoretical/modeling study (nonequilibrium Green's function) rather than experimental or epidemiological evidence.
  • No quantitative exposure parameters (e.g., field strength, frequency) are provided in the abstract.
  • No biological/health endpoints are assessed; outcomes are electronic transport properties in graphene nanoribbons.
View raw extracted JSON
{
  "study_type": "other",
  "exposure": {
    "band": null,
    "source": "rotating magnetic field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "spin-resolved pumped current",
    "pumped spin current density",
    "pumped charge current",
    "effects of static disorder (impurities/defects) on spin current",
    "effects of long-ranged charge-impurity disorder on spin current"
  ],
  "main_findings": "Using a nonequilibrium Green's function approach in a rotating reference frame, the authors derive spin-resolved pumped current in zigzag graphene nanoribbons under a transverse rotating magnetic field without applied bias. Pumped spin current density increases with system size and with the intensity of the transverse rotating magnetic field. For ribbons with an even number of zigzag chains, a nonzero pumped charge current is also predicted due to broken spatial inversion symmetry, but it is much smaller than the spin current; short-ranged static disorder can greatly depress the spin current, while long-ranged charge-impurity disorder can allow the spin current to survive in strong disorder for a single-energy mode.",
  "effect_direction": "unclear",
  "limitations": [
    "Appears to be a theoretical/modeling study (nonequilibrium Green's function) rather than experimental or epidemiological evidence.",
    "No quantitative exposure parameters (e.g., field strength, frequency) are provided in the abstract.",
    "No biological/health endpoints are assessed; outcomes are electronic transport properties in graphene nanoribbons."
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "zigzag graphene nanoribbons",
    "electron spin resonance",
    "rotating magnetic field",
    "nonequilibrium Green's function",
    "spin pumping",
    "pumped spin current",
    "pumped charge current",
    "disorder",
    "impurities",
    "defects",
    "localization",
    "inter-valley scattering"
  ],
  "suggested_hubs": []
}
AI can be wrong. Always verify against the paper.

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: 10.1088/0953-8984/22/44/445801
PubMed: 21403354

Read the original paper →

Related papers

← Back to the Research Library