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Related papers: Impurities in a Biased Graphene Bilayer

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The flat bands in bilayer graphene(BLG) are sensitive to electric fields E\bot directed between the layers, and magnify the electron-electron interaction effects, thus making BLG an attractive platform for new two-dimensional (2D) electron…

Mesoscale and Nanoscale Physics · Physics 2012-03-23 J. Velasco , L. Jing , W. Bao , Y. Lee , P. Kratz , V. Aji , M. Bockrath , C. N. Lau , C. Varma , R. Stillwell , D. Smirnov , Fan Zhang , J. Jung , A. H. MacDonald

The influence of magnetic impurities on the transport properties of graphene is investigated in the regime of strong applied electric fields. As a result of electron-hole pair creation, the response becomes nonlinear and dependent on the…

Mesoscale and Nanoscale Physics · Physics 2014-09-02 Arnaud Demion , Alberto D. Verga

Bilayer graphene is normally a semimetal with parabolic dispersion, but a tunable bandgap up to few hundreds meV can be opened by breaking the symmetry between the layers through an external potential. Ab-initio calculations show that the…

Mesoscale and Nanoscale Physics · Physics 2015-09-30 Simone De Liberato

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…

Motivated by quantum chemistry calculations, showing that molecular adsorption in graphene takes place on preferential sites of the honeycomb lattice, we study the effect of an isolated impurity on the local electronic properties of a…

Mesoscale and Nanoscale Physics · Physics 2009-09-30 F. M. D. Pellegrino , G. G. N. Angilella , R. Pucci

Screening of charge impurities in graphene is analyzed using the exact solution for vacuum polarization obtained from the massless Dirac-Kepler problem. For the impurity charge below certain critical value no density perturbation is found…

Mesoscale and Nanoscale Physics · Physics 2007-12-09 A. V. Shytov , M. I. Katsnelson , L. S. Levitov

While single-layer graphene shows extraordinary phenomena which are stable against electronic interactions, the non-interacting state of bilayer graphene is unstable to infinitesimal interactions leading to one of many possible exotic…

Mesoscale and Nanoscale Physics · Physics 2013-02-07 Lijun Zhu , Vivek Aji , Chandra M. Varma

Using first-principles plane wave calculations we predict that electronic and magnetic properties of graphene nanoribbons can be affected by defect-induced itinerant states. The band gaps of armchair nanoribbons can be modified by hydrogen…

Mesoscale and Nanoscale Physics · Physics 2008-08-12 M. Topsakal , E. Akturk , H. Sevincli , S. Ciraci

Using an external electric field, one can modulate the bandgap of Bernal stacked bilayer graphene by breaking A-~B symmetry. We analyze strain effects on the bilayer graphene using the extended Huckel theory and find that reduced interlayer…

Mesoscale and Nanoscale Physics · Physics 2009-02-03 Hassan Raza , Edwin C. Kan

Gapless bilayer graphene is susceptible to a variety of spontaneously gapped states. As predicted by theory and observed by experiment, the ground state is however topologically trivial, because a valley-independent gap is energetically…

Mesoscale and Nanoscale Physics · Physics 2017-11-08 Chunlei Qu , Chuanwei Zhang , Fan Zhang

The dependences of the maximum and the half-width of near band-edge photoluminescence of semi-insulating undoped GaAs crystals at 77K on the concentration of background acceptor impurities and the level of excitation in the range from…

Materials Science · Physics 2015-05-13 V. F. Kovalenko , S. V. Shutov , Ye. A. Baganov , M. M. Smyikalo

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

It was recently shown that a finite imbalance between electron densities in the $\mathbf{K}$ and $\mathbf{K}'$ valleys of bilayer graphene induces a magnetoelectric coupling. Here we explore ramifications of this electronically tunable…

Mesoscale and Nanoscale Physics · Physics 2017-08-22 U. Zülicke , R Winkler

Near a magic twist angle, bilayer graphene transforms from a weakly correlated Fermi liquid to a strongly correlated two-dimensional electron system with properties that are extraordinarily sensitive to carrier density and to controllable…

Mesoscale and Nanoscale Physics · Physics 2020-12-14 Eva Y. Andrei , Allan H. MacDonald

Using a first principles density functional electronic structure method, we study the energy gaps and magnetism in bilayer graphene nanoribbons as a function of the ribbon width and the strength of an external electric field between the…

Materials Science · Physics 2009-11-13 Bhagawan Sahu , Hongki Min , Allan. H. MacDonald , Sanjay K. Banerjee

Strain has been extensively employed to tailor graphene's properties and has emerged as a powerful tool for engineering gauge fields and exploring fundamental phenomena in artificial platforms like photonic graphene. Here we discover that,…

Optics · Physics 2025-09-26 Yongsheng Liang , Shiqi Xia , Daohong Song , Hrvoje Buljan , Zhigang Chen

We present non-linear transport measurements on suspended, current annealed bilayer graphene devices. Using a multi-terminal geometry we demonstrate that devices tend to be inhomogeneous and host two different electronic phases next to each…

Mesoscale and Nanoscale Physics · Physics 2012-11-14 Frank Freitag , Markus Weiss , Romain Maurand , Jelena Trbovic , Christian Schönenberger

The electronic states of a finite-width graphene sheet in the presence of an electrostatic confining potential and a perpendicular magnetic field are investigated. The confining potential shifts the Landau levels inside the well and creates…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 J. Milton Pereira , F. M. Peeters , P. Vasilopoulos

The edge states of the quantum Hall and fractional quantum Hall effect of a two-dimensional electron gas provide key access to the excitations of the bulk. Here we demonstrate controlled transmission of edge states in bilayer graphene.…

Mesoscale and Nanoscale Physics · Physics 2018-02-06 Jing Li , Hua Wen , Kenji Watanabe , Takashi Taniguchi , Jun Zhu

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…