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When an electron is confined to a triangular atomic thick layer of graphene [1-5] with zig-zag edges, its energy spectrum collapses to a shell of degenerate states at the Fermi level (Dirac point) [6-9]. The degeneracy is proportional to…

Materials Science · Physics 2013-05-29 A. D. Guclu , P. Potasz , O. Voznyy , M. Korkusinski , P. Hawrylak

Electrons in two-dimensional graphene sheets behave as interacting chiral Dirac fermions and have unique screening properties due to their symmetry and reduced dimensionality. By using a combination of scanning tunneling spectroscopy…

We use Pseudo Quantum Electrodynamics (PQED) in order to describe the full electromagnetic interaction of the p-electrons of graphene in a consistent 2D formulation. We first consider the effect of this interaction in the vacuum…

Strongly Correlated Electrons · Physics 2015-04-08 E. C. Marino , Leandro O. Nascimento , Van Sergio Alves , C. Morais Smith

The recent experimental observations of designer Dirac Fermions and topological phases in molecular graphene are addressed theoretically. Using scattering theory we calculate the electronic structure of finite lattices of scattering centers…

Mesoscale and Nanoscale Physics · Physics 2013-12-18 H. Hammar , P. Berggren , J. Fransson

In two-dimensional (2D) electron systems under strong magnetic fields, interactions can cause fractional quantum Hall (FQH) effects. Bringing two 2D conductors to proximity, a new set of correlated states can emerge due to interactions…

Mesoscale and Nanoscale Physics · Physics 2020-07-17 Xiaomeng Liu , Zeyu Hao , Kenji Watanabe , Takashi Taniguchi , Bertrand Halperin , Philip Kim

Bilayer graphene in a magnetic field supports eight zero-energy Landau levels, which, as a tunable band gap develops, split into two nearly-degenerate quartets separated by the band gap. A close look is made into the properties of such an…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 K. Shizuya

We review the theoretical basis and understanding of electronic interactions in graphene Landau levels, in the limit of strong correlations. This limit occurs when inter-Landau-level excitations may be omitted because they belong to a…

Mesoscale and Nanoscale Physics · Physics 2012-02-03 M. O. Goerbig , N. Regnault

Vertical heterostructures combining different layered materials offer novel opportunities for applications and fundamental studies of collective behavior driven by inter-layer Coulomb coupling. Here we report heterostructures comprising a…

Mesoscale and Nanoscale Physics · Physics 2015-01-09 A. Gamucci , D. Spirito , M. Carrega , B. Karmakar , A. Lombardo , M. Bruna , A. C. Ferrari , L. N. Pfeiffer , K. W. West , Marco Polini , V. Pellegrini

Graphene is a recently discovered carbon based material with unique physical properties. This is a monolayer of graphite, and the two-dimensional electrons and holes in it are described by the effective Dirac equation with a vanishing…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. A. Mikhailov , K. Ziegler

We present a supersymmetric description of the quantum Hall effect (QHE) in graphene. The noninteracting system is supersymmetric separately at the so-called K and K' points of the Brillouin zone corners. Its essential consequence is that…

Mesoscale and Nanoscale Physics · Physics 2007-12-15 Motohiko Ezawa

We present extensive numerical results for the thermodynamic density of states (i.e. quantum capacitance) of a two-dimensional massless Dirac fermion fluid in a doped graphene sheet. In particular, by employing the random phase…

Mesoscale and Nanoscale Physics · Physics 2014-10-23 Reza Asgari , Mikhail I. Katsnelson , Marco Polini

Fractional Quantum Hall effect (FQHE) is a unique many-body phenomenon, which was discovered in a two-dimensional electron system placed in a strong perpendicular magnetic field. It is entirely due to the electron-electron interactions…

Mesoscale and Nanoscale Physics · Physics 2022-07-15 Vadym Apalkov , Tapash Chakraborty

We investigate a valleytronic device based on graphene with charge separation at different sublattices and correspondingly at nonequivalent valleys. We characterize the maximality condition of valley polarization and investigate the…

Mesoscale and Nanoscale Physics · Physics 2021-01-08 Hamed Koochaki Kelardeh , Mohammadreza Eidi , Takashi Oka , Jan Michael Rost

We investigate theoretically the cavity quantum electrodynamics of the cyclotron transition for Dirac fermions in graphene. We show that the ultrastrong coupling regime characterized by a vacuum Rabi frequency comparable or even larger than…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 David Hagenmüller , Cristiano Ciuti

By combining analytic and numerical methods, edge states on a finite width graphene ribbon in a magnetic field are studied in the framework of low-energy effective theory that takes into account the possibility of quantum Hall…

Mesoscale and Nanoscale Physics · Physics 2009-03-25 V. P. Gusynin , V. A. Miransky , S. G. Sharapov , I. A. Shovkovy , C. M. Wyenberg

We examine the 1/N expansion, where N is the number of two-component Dirac fermions, for Coulomb interactions in graphene with a gap of magnitude $\Delta = 2 m$. We find that for $N\alpha\gg1$, where $\alpha$ is graphene's "fine structure…

Mesoscale and Nanoscale Physics · Physics 2022-03-07 Valeri N. Kotov , Bruno Uchoa , A. H. Castro Neto

In mean-field-theory bilayer graphene's massive Dirac fermion model has a family of broken inversion symmetry ground states with charge gaps and flavor dependent spontaneous inter layer charge transfers. We use a lattice Hartree-Fock model…

Mesoscale and Nanoscale Physics · Physics 2011-04-22 Jeil Jung , Fan Zhang , Allan H. MacDonald

Nontrivial interacting phases can emerge in elementary materials. As a prime example, continuing advances in device quality have facilitated the observation of a variety of spontaneous quantum Hall-like states, a cascade of Stoner-like…

Mesoscale and Nanoscale Physics · Physics 2024-08-30 Felix Winterer , Fabian R. Geisenhof , Noelia Fernandez , Anna M. Seiler , Fan Zhang , R. Thomas Weitz

Hall conductance $\sigma_{xy}$ as the Chern numbers of the Berry connection in the magnetic Brillouin zone is calculated for a realistic multi band tight-band model of graphene with non-orthogonal basis. It is confirmed that the envelope of…

Mesoscale and Nanoscale Physics · Physics 2015-03-30 M. Arai , Y. Hatsugai

The paper addresses boundary electronic properties of graphene with a complex edge structure of the armchair/zigzag/armchair type. It is shown that the finite zigzag region supports edge bound states with discrete equidistant spectrum…

Mesoscale and Nanoscale Physics · Physics 2009-02-02 Grigory Tkachov