scholarly journals Energy Gap Induced by Friedel Oscillations Manifested as Transport Asymmetry at Monolayer-Bilayer Graphene Boundaries

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Kendal W. Clark ◽  
X.-G. Zhang ◽  
Gong Gu ◽  
Jewook Park ◽  
Guowei He ◽  
...  
Keyword(s):  
Energy Gap ◽  
Bilayer Graphene ◽  
Friedel Oscillations

Tuning field-induced energy gap of bilayer graphene via interlayer spacing

2008 ◽  
Vol 92 (24) ◽  
pp. 243101 ◽  
Author(s):  
Yufeng Guo ◽  
Wanlin Guo ◽  
Changfeng Chen
Keyword(s):  
Energy Gap ◽  
Interlayer Spacing ◽  
Bilayer Graphene

scholarly journals Controlling Energy Gap of Bilayer Graphene by Strain

Nano Letters ◽  
2010 ◽  
Vol 10 (9) ◽  
pp. 3486-3489 ◽  
Author(s):  
Seon-Myeong Choi ◽  
Seung-Hoon Jhi ◽  
Young-Woo Son
Keyword(s):  
Energy Gap ◽  
Bilayer Graphene

scholarly journals Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Hediyeh Karimi ◽  
Rubiyah Yusof ◽  
Mohammad Taghi Ahmadi ◽  
Mehdi Saeidmanesh ◽  
Meisam Rahmani ◽  
...  
Keyword(s):  
Analytical Model ◽  
Field Effect ◽  
Energy Gap ◽  
Field Effect Transistors ◽  
Bilayer Graphene ◽  
Quantum Capacitance ◽  
Chemical Doping ◽  
Layer Graphene ◽  
Capacitance Variation ◽  
Acceptable Agreement

Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presented, and also based on the analytical model a numerical solution is reported. We begin by modeling the DOS, followed by carrier concentration as a functionVin degenerate and nondegenerate regimes. To further confirm this viewpoint, the presented analytical model is compared with experimental data, and acceptable agreement is reported.

scholarly journals Correlated insulating and superconducting states in twisted bilayer graphene below the magic angle

2019 ◽  
Vol 5 (9) ◽  
pp. eaaw9770 ◽  
Author(s):  
Emilio Codecido ◽  
Qiyue Wang ◽  
Ryan Koester ◽  
Shi Che ◽  
Haidong Tian ◽  
...  
Keyword(s):  
Energy Gap ◽  
Twist Angle ◽  
High Energy ◽  
Bilayer Graphene ◽  
Unit Cell ◽  
Flat Band ◽  
Magic Angle ◽  
Strongly Correlated ◽  
New Information ◽  
Twisted Bilayer Graphene

The emergence of flat bands and correlated behaviors in “magic angle” twisted bilayer graphene (tBLG) has sparked tremendous interest, though its many aspects are under intense debate. Here we report observation of both superconductivity and the Mott-like insulating state in a tBLG device with a twist angle of ~0.93°, which is smaller than the magic angle by 15%. At an electron concentration of ±5 electrons/moiré unit cell, we observe a narrow resistance peak with an activation energy gap ~0.1 meV. This indicates additional correlated insulating state, and is consistent with theory predicting a high-energy flat band. At doping of ±12 electrons/moiré unit cell we observe resistance peaks arising from the Dirac points in the spectrum. Our results reveal that the “magic” range of tBLG is in fact larger than what is previously expected, and provide a wealth of new information to help decipher the strongly correlated phenomena observed in tBLG.

scholarly journals Electronic properties of twisted bilayer graphene in high-energy k ⋅p-Hamiltonian approximation

2020 ◽  
Vol 34 (19n20) ◽  
pp. 2040055
Author(s):  
H. V. Grushevskaya ◽  
G. G. Krylov ◽  
H.-Y. Choi ◽  
S. P. Kruchinin
Keyword(s):  
Band Structure ◽  
Rotation Angle ◽  
Energy Gap ◽  
High Energy ◽  
Bilayer Graphene ◽  
Monolayer Graphene ◽  
Abelian Gauge ◽  
Relativistic Approach ◽  
Energy Formula ◽  
Twisted Bilayer Graphene

A model of twisted bilayer graphene has been offered on the base of developed quasi-relativistic approach with high energy [Formula: see text]-Hamiltonian. Monolayer-graphene twist is accounted as a perturbation of monolayer-graphene Hamiltonian in such a way that at a given point of the Brillouin zone there exists an external non-Abelian gauge field of another monolayer. Majorana-like resonances have been revealed in the band structure of model at a magic rotation angle [Formula: see text]. The simulations have also shown that a superlattice energy gap existing at a rotation angle [Formula: see text] vanishes at a rotation angle [Formula: see text].

Adsorption-site dependence of electronic and magnetic properties of hydrogen impurities on bilayer graphene

2015 ◽  
Vol 29 (28) ◽  
pp. 1550198
Author(s):  
Mahboobeh Mirzadeh ◽  
Mani Farjam
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Magnetic Moments ◽  
Tight Binding ◽  
Bilayer Graphene ◽  
Binding Model ◽  
Electronic And Magnetic Properties ◽  
A Site ◽  
Site Dependence

In bilayer graphene, the A and B sites in each layer have different local electronic structures due to the presence of the second layer. In this work, using first-principles calculations, we examine the effect of sublattice inequivalence on various properties of hydrogen defects in bilayer graphene. Density functional calculations show that induced magnetic moments by H adsorption on A and B sites of bilayer graphene are both equal to [Formula: see text] at zero temperature, but change slightly and develop a mismatch at finite temperature. We show how this variation follows from the fact that H on A site remains gapless but H on B site opens an energy gap. We also use a tight-binding model to explain the differences in band structures for H adsorption on A and B sites. The results obtained in this work suggest that there are important differences in electronic and magnetic properties between H adsorption on monolayer and bilayer graphene.

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