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A formalism is proposed to study the electronic and transport properties of graphene sheets with corrugations as the one recently synthesized. The formalism is based on coupling the Dirac equation that models the low energy electronic…

Strongly Correlated Electrons · Physics 2008-11-26 Alberto Cortijo , María A. H. Vozmediano

Structural distortions and imperfections are a crucial aspect of materials science, on the macroscopic scale providing strength, but also enhancing corrosion and reducing electrical and thermal conductivity. At the nanometre scale,…

Superconductivity · Physics 2024-05-08 A. Mesaros , G. D. Gu , F. Massee

The opening of an energy gap in the electronic structure generally indicates the presence of interactions. In materials with low carrier density and short screening length, long-range Coulomb interaction favors the spontaneous formation of…

Graphene grown on metal surface, Cu(111), with a boron nitride(BN) buffer layer is studied for the first time. Our first-principles calculations reveal that charge is transferred from the copper substrate to graphene through the BN buffer…

Materials Science · Physics 2007-12-27 Y. H. Lu , P. M. He , Y. P. Feng

Generation mechanism of energy gaps between conductance and valence bands is at the centre of the study of graphene material. Recently Chamon, Jackiw, et al. proposed a mechanism of using a Kekul\'{e} distortion background field $% \varphi…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Xin Liu , Ruibin Zhang

We provide a thorough study of a carbon divacancy, a fundamental but almost unexplored point defect in graphene. Low temperature scanning tunneling microscopy (STM) imaging of irradiated graphene on different substrates enabled us to…

The electronic structure of a single-layer graphene with a periodic Fermi velocity modulation is investigated by using an effective Dirac-like Hamiltonian. In a gapless graphene or in a graphene with a constant energy gap the modulation of…

Materials Science · Physics 2014-12-02 Jonas R. F. Lima

The low energy physics of both graphene and surface states of three-dimensional topological insulators is described by gapless Dirac fermions with linear dispersion. In this work, we predict the emergence of a "heavy" Dirac fermion in a…

Mesoscale and Nanoscale Physics · Physics 2016-10-17 Wendong Cao , Rui-Xing Zhang , Peizhe Tang , Gang Yang , Jorge Sofo , Wenhui Duan , Chao-Xing Liu

We consider the stability of fragile topological bands protected by space-time inversion symmetry in the presence of strong electron-electron interactions. At the single-particle level, the topological nature of the bands prevents the…

Strongly Correlated Electrons · Physics 2022-02-21 Ari M. Turner , Erez Berg , Ady Stern

In this Letter, we derive an effective theory of graphene on a hexagonal Boron Nitride (h-BN) substrate. We show that the h-BN substrate generically opens a spectral gap in graphene despite the lattice mismatch. The origin of that gap is…

Mesoscale and Nanoscale Physics · Physics 2012-11-12 M. Kindermann , Bruno Uchoa , D. L. Miller

The spectrum of excitations a two-dimensional, planar honeycomb lattice of two-level atoms coupled by the in-plane electromagnetic field may exhibit band gaps that can be opened either by applying an external magnetic field or by breaking…

Quantum Physics · Physics 2024-03-27 Pierre Wulles , Sergey E. Skipetrov

We exploit the concept of strain-induced band structure engineering in graphene through the calculation of its electronic properties under uniaxial, shear, and combined uniaxial-shear deformations. We show that by combining shear…

Mesoscale and Nanoscale Physics · Physics 2010-06-24 Giulio Cocco , Emiliano Cadelano , Luciano Colombo

Graphene and few-layer graphene at high bias expose a wealth of phenomena due to the high temperatures reached. With in-situ transmission electron microscopy (TEM) we observe directly how the current modifies the structure, and vice versa.…

Mesoscale and Nanoscale Physics · Physics 2013-01-30 Amelia Barreiro , Felix Boerrnert , Mark H. Ruemmeli , Bernd Buechner , Lieven M. K. Vandersypen

Graphene on a dielectric substrate exhibits spatial doping inhomogeneities, forming electron-hole puddles. Understanding and controlling the latter is of crucial importance for unraveling many of graphene's fundamental properties at the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 S. C. Martin , S. Samaddar , B. Sacépé , A. Kimouche , J. Coraux , F. Fuchs , B. Grévin , H. Courtois , C. B. Winkelmann

The adsorption of an alkali-metal submonolayer on graphene occupying every third hexagon of the honeycomb lattice in a commensurate $(\sqrt{3}\times\sqrt{3})R30^\circ$ arrangement induces an energy gap in the spectrum of graphene. To…

Materials Science · Physics 2009-01-27 M. Farjam , H. Rafii-Tabar

Here we report a facile method to generate a high density of point defects in graphene on metal foil and show how the point defects affect the electronic structures of graphene layers. Our scanning tunneling microscopy (STM) measurements,…

Mesoscale and Nanoscale Physics · Physics 2013-10-08 Hui Yan , Cheng-Cheng Liu , Ke-Ke Bai , Xuejiao Wang , Mengxi Liu , Wei Yan , Lan Meng , Yanfeng Zhang , Zhongfan Liu , Jia-Cai Nie , Yugui Yao , Lin He

It is shown that, contrary to the naive expectation, single particle spectral gaps can be opened on the surface states of three dimensional topological insulators by using commensurate out- and in-plane antiferromagnetic or ferrimagnetic…

Materials Science · Physics 2015-03-20 László Oroszlány , Alberto Cortijo

For gapped graphene, we predict that an intense ultrashort (single-oscillation) circularly-polarized optical pulse can induce a large population of the conduction band and a large valley polarization. With an increase in the bandgap, the…

Mesoscale and Nanoscale Physics · Physics 2019-09-25 S. Azar Oliaei Motlagh , Fatemeh Nematollahi , Vadym Apalkov , Mark I. Stockman

Using a tight-binding model, we study a line defect in graphene where a bulk energy gap is opened by sublattice symmetry breaking. It is found that sublattice symmetry breaking may induce many configurations that correspond to different…

Mesoscale and Nanoscale Physics · Physics 2013-03-05 Juntao Song , Haiwen Liu , Hua Jiang , Qing-feng Sun , X. C. Xie

We investigate the effect of topological defects on the transport properties of a narrow ballistic ribbon of graphene with zigzag edges. Our results show that the longitudinal conductance vanishes at several discrete Fermi energies where…

Mesoscale and Nanoscale Physics · Physics 2008-10-11 Yan-Yang Zhang , Jiang-Ping Hu , B. A. Bernevig , X. R. Wang , X. C. Xie , W. M. Liu