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Related papers: Tuning impurity states in bilayer graphene

200 papers

We report on infrared spectroscopy of bilayer graphene integrated in gated structures. We observed a significant asymmetry in the optical conductivity upon electrostatic doping of electrons and holes. We show that this finding arises from a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Z. Q. Li , E. A. Henriksen , Z. Jiang , Z. Hao , M. C. Martin , P. Kim , H. L. Stormer , D. N. Basov

We consider bilayer graphene in the presence of spin orbit coupling, to assess its behavior as a topological insulator. The first Chern number $n$ for the energy bands of single and bilayer graphene is computed and compared. It is shown…

Mesoscale and Nanoscale Physics · Physics 2011-07-18 E. Prada , P. San-Jose , L. Brey , H. A. Fertig

We consider the most energetically favorable symmetry-allowed spin-singlet and spin-triplet superconducting pairing symmetries in twisted bilayer graphene at the magic angle, whose normal state physics is described by a six-band effective…

Superconductivity · Physics 2023-07-27 Emile Pangburn , Miguel Alvarado , Oladunjoye A. Awoga , Catherine Pépin , Cristina Bena

Owing to the spin, valley, and orbital symmetries, the lowest Landau level (LL) in bilayer graphene exhibits multicomponent quantum Hall ferromagnetism. Using transport spectroscopy, we investigate the energy gaps of integer and fractional…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 Yanmeng Shi , Yongjin Lee , Shi Che , Ziqi Pi , Timothy Espiritu , Petr Stepanov , Dmitry Smirnov , Chun Ning Lau , Fan Zhang

Twisted bilayer graphene (tBLG) represents a family of unique materials with optoelectronic properties tuned by the rotation angle between the two layers. The presented work shows an additional way of tweaking the electronic structure of…

The ground-state and the transport properties of graphene subject to the potential of in-plane charged impurities are studied. The screening of the impurity potential is shown to be nonlinear, producing a fractal structure of electron and…

Mesoscale and Nanoscale Physics · Physics 2009-12-02 M. M. Fogler

We study the low energy edge states of bilayer graphene in a strong perpendicular magnetic field. Several possible simple boundaries geometries related to zigzag edges are considered. Tight-binding calculations reveal three types of edge…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Victoria Mazo , Efrat Shimshoni , Herbert A. Fertig

We address local inelastic scattering from vibrational impurity adsorbed onto graphene and the evolution of the local density of electron states near the impurity from weak to strong coupling regime. For weak coupling the local electronic…

Mesoscale and Nanoscale Physics · Physics 2013-06-10 J. Fransson , J. -H. She , L. Pietronero , A. V. Balatsky

We map out the possible ordered states in bilayer graphene at the neutrality point by extending the previous renormalization group treatment of many-body instabilities to finite temperature, trigonal warping and externally applied…

Strongly Correlated Electrons · Physics 2012-09-04 Vladimir Cvetkovic , Robert E. Throckmorton , Oskar Vafek

We study the different response to an impurity of the two topologically different phases shown by a two dimensional insulator with time reversal symmetry, namely, the Quantum Spin Hall and the normal phase. We consider the case of graphene…

Mesoscale and Nanoscale Physics · Physics 2012-09-24 J. W. González , J. Fernández-Rossier

Bilayer graphene (BLG) at the charge neutrality point (CNP) is strongly susceptible to electronic interactions, and expected to undergo a phase transition into a state with spontaneous broken symmetries. By systematically investigating a…

Mesoscale and Nanoscale Physics · Physics 2012-08-01 Wenzhong Bao , Jairo Velasco , Fan Zhang , Lei Jing , Brian Standley , Dmitry Smirnov , Marc Bockrath , Allan MacDonald , Chun Ning Lau

A numerical method for calculation of the electronic structure of transition metal impurities in semiconductors based on the Green function technique is developed. The electronic structure of 3d impurity is calculated within the LDA+U…

Other Condensed Matter · Physics 2009-11-13 O. V. Farberovich , A. Yaresko , K. Kikoin , V. Fleurov

We present a self-consistent calculation of the interlayer asymmetry in bilayer graphene caused by an applied electric field in magnetic fields. We show how this asymmetry influences the Landau level spectrum in bilayer graphene and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 M. Mucha-Kruczynski , E. McCann , V. I. Fal'ko

At the interface of electrostatic potential kink profiles one dimensional chiral states are found in bilayer graphene (BLG). Such structures can be created by applying an asymmetric potential to the upper and the lower layer of BLG. We…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 M. Zarenia , J. M. Pereira , G. A. Farias , F. M. Peeters

We show nonlinear transport experiments on clean, suspended bilayer graphene that reveal a gap in the density of states. Looking at the evolution of the gap in magnetic fields of different orientation, we find that the groundstate is a…

Mesoscale and Nanoscale Physics · Physics 2013-04-16 Frank Freitag , Markus Weiss , Romain Maurand , Jelena Trbovic , Christian Schönenberger

Random vacancies in a graphene monolayer induce defect states that are known to form a narrow impurity band centered around zero energy at half-filling. We use a space-resolved formulation of the quantum metric and establish a strong…

Mesoscale and Nanoscale Physics · Physics 2024-08-01 Quentin Marsal , Annica M. Black-Schaffer

We calculate the optical sum associated with the in-plane conductivity of a graphene bilayer. A bilayer asymmetry gap generated in a field-effect device can split apart valence and conduction bands, which otherwise would meet at two K…

Mesoscale and Nanoscale Physics · Physics 2008-04-08 L. Benfatto , S. G. Sharapov , J. P. Carbotte

We study the electronic structure of graphene with a single substitutional vacancy using a combination of the density-functional, tight-binding, and impurity Green's function approaches. Density functional studies are performed with the…

Mesoscale and Nanoscale Physics · Physics 2012-08-09 B. R. K. Nanda , M. Sherafati , Z. Popović , S. Satpathy

Electronic properties of bilayer and multilayer graphene have generally been interpreted in terms of AB or Bernal stacking. However, it is known that many types of stacking defects can occur in natural and synthetic graphite; rotation of…

Materials Science · Physics 2011-11-09 J. M. B. Lopes dos Santos , N. M. R. Peres , A. H. Castro Neto

We present the complete formalism that describes scattering in graphene at low-energies. We begin by analyzing the real-space free Green's function matrix, and its analytical expansions at low-energy, carefully incorporating the discrete…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Cristina Bena