Enhancement of the Fano-resonance response in bilayer graphene single and double barriers induced by bandgap opening
| Autor: | Rolando Pérez-Alvarez, René Pernas-Salomón, J. A. Briones-Torres, Isaac Rodríguez-Vargas |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed matter physics Graphene Band gap Physics::Optics Conductance Fano resonance 02 engineering and technology Fano plane Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention law 0103 physical sciences 010306 general physics 0210 nano-technology Electronic band structure Bilayer graphene Quantum tunnelling |
| Zdroj: | Physica E: Low-dimensional Systems and Nanostructures. 119:113999 |
| ISSN: | 1386-9477 |
| DOI: | 10.1016/j.physe.2020.113999 |
| Popis: | Fano resonances in bilayer graphene arise due to the coupling between extended and discrete electrons states, and represent an exotic phenomenon in graphene akin to Klein and anti-Klein tunneling, atomic collapse and negative refraction to mention a few. The hallmark of these resonances is identifiable in the conductance curves of bilayer graphene barrier structures. Furthermore, the Fano line-shape can be presented in the conductance by reducing the angular range in the computation of the transport properties. In this work, we explore the possible consequences that bandgap opening in the band structure of bilayer graphene can have over Fano resonances. We have used a four-band Hamiltonian to taking into account the mentioned band structure modifications. The hybrid matrix method and the Landauer–Buttiker formalism have been implemented to obtain the transmittance and the conductance, respectively. We find that the signatures of the Fano resonances on the conductance are enhanced by the opening of the bandgap. In fact, the Fano profile is manifested in the conductance without the need of reducing the angular range. This enhancement results from the improvement of the chirality matching between extended and discrete states induced by the bandgap opening. The main characteristics of the impact of the bandgap opening on the transmission and transport properties of single and double barriers are presented. So, the bandgap opening far from hamper the Fano resonance response promotes it and can be used as modulation parameter to prove the exotic phenomenon of Fano resonances in bilayer graphene barrier structures. |
| Databáze: | OpenAIRE |
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