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Updated: Jun 25, 2025
11:42
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
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Extended states in random dimer gated graphene superlattices
R Rodríguez-González1, H García-Cervantes2, F J García-Rodríguez3
1Unidad Académica de Ciencia y Tecnología de la Luz y la Materia, Universidad Autónoma de Zacatecas, Circuto Marie Curie S/N, Parque de Ciencia y Tecnología QUANTUM Ciudad del Conocimiento, 98160 Zacatecas, Zacatecas, Mexico.
Summary
Disordered dimer superlattices in graphene surprisingly exhibit extended states, unlike typical disordered systems. Their conductance is intermediate, offering new possibilities for electronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Semiconductor superlattices exhibit distinct properties based on order: ordered structures show extended Bloch states and high conductance, while disordered ones display localized states and lower conductance.
- Disordered dimer superlattices, featuring paired quantum wells, unexpectedly demonstrate extended states, challenging conventional understanding.
Purpose of the Study:
- To investigate the electronic transport properties of disordered dimer superlattices in graphene.
- To understand the mechanisms behind extended states in these unique disordered structures.
- To identify energy regions where conductance is intermediate between ordered and disordered superlattices.
Main Methods:
- Utilized the transfer matrix method to calculate transmission properties.
- Applied the Landauer-Büttiker formalism to determine transport characteristics.
- Analyzed resonant energies of double quantum well cavities and electronic structure of gated graphene superlattices (GGSLs).
Main Results:
- Disordered dimer superlattices in graphene exhibit extended electronic states, contrary to typical disordered systems.
- The conductance of these superlattices is found to be intermediate between ordered and disordered counterparts.
- Extended states arise from the coupling between resonant energies of double quantum wells and the minibands of the GGSL.
Conclusions:
- Disordered dimer superlattices in graphene present a novel class of materials with tunable electronic properties.
- The findings challenge the dichotomy between ordered (extended states) and disordered (localized states) systems.
- This research opens avenues for designing advanced electronic devices utilizing controlled disorder in graphene superlattices.
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