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Twisted bilayer graphene with a twist angle of around 1.1{\deg} features a pair of isolated flat electronic bands and forms a strongly correlated electronic platform. Here, we use scanning tunneling microscopy to probe local properties of…

In the present work, we consider the excitonic effects in the twisted bilayer graphene (tBLG) within the rotated bilayer Hubbard model. Both, intralayer and interlayer Coulomb interactions have been considered and the half-filling condition…

Mesoscale and Nanoscale Physics · Physics 2022-01-25 V. Apinyan , T. K. Kopeć

The low-energy bands of twisted bilayer graphene form Dirac cones with approximate electron-hole symmetry at small rotation angles. These crossings are protected by the emergent symmetries of moir\'e patterns, conferring a topological…

Mesoscale and Nanoscale Physics · Physics 2020-11-25 Hector Ochoa

We present electronic structure calculations of twisted double bilayer graphene (TDBG): A tetralayer graphene structure composed of two AB-stacked graphene bilayers with a relative rotation angle between them. Using first-principles…

Mesoscale and Nanoscale Physics · Physics 2019-11-05 F. J. Culchac , Rodrigo B. Capaz , Leonor Chico , E. Suarez Morell

We study, within the tight-binding approximation, the electronic properties of a graphene bilayer in the presence of an external electric field applied perpendicular to the system -- \emph{biased bilayer}. The effect of the perpendicular…

We extensively investigate the electronic and transport properties of a twisted bilayer graphene when subjected to both an external perpendicular electric field and a magnetic field. Using a basic tight-binding model, we show the flat…

Mesoscale and Nanoscale Physics · Physics 2023-11-13 Priyanka Sinha , Ayan Mondal , Simão Meneses João , Bheema Lingam Chittari

We analyze the phase diagram of twisted graphene bilayers near a magic angle. We consider the effect of the long range Coulomb interaction, treated within the self consistent Hartree-Fock approximation, and we study arbitrary band fillings.…

Strongly Correlated Electrons · Physics 2020-07-15 Tommaso Cea , Francisco Guinea

We study the electronic properties of a twisted trilayer graphene, where two of the layers have Bernal stacking and the third one has a relative rotation with respect to the AB-stacked layers. Near the Dirac point, the AB-twisted trilayer…

Mesoscale and Nanoscale Physics · Physics 2013-04-02 E. Suárez Morell , M. Pacheco , L. Chico , L. Brey

Electron interactions in undoped bilayer graphene lead to instability of the gapless state, `which-layer' symmetry breaking, and energy gap opening at the Dirac point. In contrast to single layer graphene, the bilayer system exhibits…

Mesoscale and Nanoscale Physics · Physics 2010-04-16 Rahul Nandkishore , Leonid Levitov

Bilayer graphene twisted by a small angle shows a significant charge modulation away from neutrality, as the charge in the narrow bands near the Dirac point is mostly localized in the regions of the Moir\'e pattern with $AA$ stacking. The…

Mesoscale and Nanoscale Physics · Physics 2018-12-13 Francisco Guinea , Niels R. Walet

Bilayer graphene has drawn significant attention due to the opening of a band gap in its low energy electronic spectrum, which offers a promising route to electronic applications. The gap can be either tunable through an external electric…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Gregory M. Rutter , Suyong Jung , Nikolai N. Klimov , David B. Newell , Nikolai B. Zhitenev , Joseph A. Stroscio

Bilayer graphene -- two coupled single graphene layers stacked as in graphite -- provides the only known semiconductor with a gap that can be tuned externally through electric field effect. Here we use a tight binding approach to study how…

Mesoscale and Nanoscale Physics · Physics 2010-04-29 Eduardo V. Castro , N. M. R. Peres , J. M. B. Lopes dos Santos , F. Guinea , A. H. Castro Neto

We explore the rotational degree of freedom between graphene layers via the simple prototype of the graphene twist bilayer, i.e., two layers rotated by some angle $\theta$. It is shown that, due to the weak interaction between graphene…

Materials Science · Physics 2015-03-13 S. Shallcross , S. Sharma , E. Kandelaki , O. A. Pankratov

Twisted two-dimensional structures open new possibilities in band structure engineering. At magic twist angles, flat bands emerge, which give a new drive to the field of strongly correlated physics. In twisted double bilayer graphene dual…

We demonstrate that the electronic gap of a graphene bilayer can be controlled externally by applying a gate bias. From the magneto-transport data (Shubnikov-de Haas measurements of the cyclotron mass), and using a tight binding model, we…

We study the electronic properties of twisted bilayers graphene in the tight-binding approximation. The interlayer hopping amplitude is modeled by a function, which depends not only on the distance between two carbon atoms, but also on the…

Mesoscale and Nanoscale Physics · Physics 2015-08-12 A. O. Sboychakov , A. L. Rakhmanov , A. V. Rozhkov , Franco Nori

We present atomistic calculations on structural and electronic properties of twisted double bilayer graphene (TDBG) consisting of two sets of rotationally misaligned Bernal-stacked bilayer graphene. Obtained equilibrium atomic structures…

Mesoscale and Nanoscale Physics · Physics 2019-11-20 Young Woo Choi , Hyoung Joon Choi

Using the renormalized-ring-diagram approximation, we study the compressibility of the interacting electrons in bilayer graphene. The compressibility is equivalent to the spin susceptibility apart from a constant factor. The chemical…

Strongly Correlated Electrons · Physics 2015-05-27 Xin-Zhong Yan , C. S. Ting

We investigate theoretically the interplay between the effects of a perpendicular electric field and incommensurability at the interface on the electronic properties of a heterostructure of bilayer graphene and a semiconducting substrate…

Mesoscale and Nanoscale Physics · Physics 2016-11-02 D. J. Leech , M. Mucha-Kruczyński

We study the electronic band structure and the topological property of the twisted double bilayer graphene, or a pair of AB-stacked bilayer graphenes rotationally stacked on top of each other. We consider two different arrangements, AB-AB…

Mesoscale and Nanoscale Physics · Physics 2019-06-10 Mikito Koshino
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