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Related papers: Spectral gaps in graphene antidot lattices

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A so-called artificial graphene is an artificial material whose low-energy carriers are described by the massless Dirac equation. Applying a periodic potential with triangular symmetry to a two-dimensional electron gas is one way to make…

Mesoscale and Nanoscale Physics · Physics 2016-02-18 Pilkwang Kim , Cheol-Hwan Park

On the basis of first-principles calculations, we report that a novel interfacial atomic structure occurs between graphene and the surface of silicon carbide, destroying the Dirac point of graphene and opening a substantial energy gap…

Materials Science · Physics 2008-04-30 Seungchul Kim , Jisoon Ihm , Hyoung Joon Choi , Young-Woo Son

Much attention has been focused on ways of rendering graphene semiconducting. We study periodically gated graphene in a tight-binding model and find that, contrary to predictions based on the Dirac equation, it is possible to open a band…

Mesoscale and Nanoscale Physics · Physics 2012-10-10 Jesper Goor Pedersen , Thomas Garm Pedersen

Gap opening in graphene is usually discussed in terms of a semiconducting-like spectrum, where the appearance of a finite gap at the Dirac point is accompanied by a finite mass for the fermions. In this Letter we propose a gap scenario from…

Mesoscale and Nanoscale Physics · Physics 2008-10-03 L. Benfatto , E. Cappelluti

Motivated by graphene-based quantum computer we examine the time-dependence of the position-momentum and position-velocity uncertainties in the monolayer gapped graphene. The effect of the energy gap to the uncertainties is shown to appear…

Quantum Physics · Physics 2012-03-21 Eylee Jung , Kwang S. Kim , DaeKil Park

We demonstrate numerically that partially incoherent light can be trapped in the spectral band gaps of a photonic lattice, creating partially incoherent multi-component spatial optical solitons in a self-defocusing nonlinear periodic…

Pattern Formation and Solitons · Physics 2007-05-23 Kristian Motzek , Andrey A. Sukhorukov , Friedemann Kaiser , Yuri S. Kivshar

Scattering problem for electrons in monolayer graphene with short-range perturbations of the types "local chemical potential" and "local gap" has been solved. Zero gap and non-zero gap kinds of graphene are considered. The determined…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Natalie E. Firsova , Sergey A. Ktitorov

In this review we highlight recent theoretical and experimental work on sublattice asymmetric doping of impurities in graphene, with a focus on substitutional Nitrogen dopants. It is well known that one current limitation of graphene in…

Mesoscale and Nanoscale Physics · Physics 2014-11-13 James A. Lawlor , Mauro S. Ferreira

We calculate the dynamical polarization function and solve a self-consistent gap equation in the random phase approximation in undoped ABC-stacked n-layer graphene. We find that the gap is maximal in trilayer graphene and decreases…

Strongly Correlated Electrons · Physics 2013-12-04 Junji Jia , E. V. Gorbar , V. P. Gusynin

The phenomenon of photonic band gaps in one-dimensional optical lattices is reviewed using a microscopic approach. Formally equivalent to the transfer matrix approach in the thermodynamic limit, a microscopic model is required to study…

Electrons in graphene with heavy adatoms (such as In or Tl) have been predicted to form a 2D topological insulator phase with a substantial spectral gap potentially suitable for future practical applications. In order to facilitate the…

Mesoscale and Nanoscale Physics · Physics 2014-06-02 Paul Soulé , Marcel Franz

In this paper, we study the problem of scattering by several strictly convex obstacles, with smooth boundary and satisfying a non eclipse condition. We show, in dimension 2 only, the existence of a spectral gap for the meromorphic…

Spectral Theory · Mathematics 2024-05-01 Lucas Vacossin

We present a mechanism for the creation of gaps in the spectra of self-adjoint operators defined over a Hilbert space of functions on a graph, which is based on the process of graph decoration. The resulting Hamiltonians can be viewed as…

Mathematical Physics · Physics 2009-09-25 Jeffrey H. Schenker , Michael Aizenman

We identify explicit conditions on geometry and material contrast for creating band gaps in 2-d photonic and 3-d acoustic crystals. This approach is novel and makes use of the electro-static and quasi-periodic source free resonances of the…

Analysis of PDEs · Mathematics 2016-09-07 Robert Lipton , Robert Viator

General properties of long wavelength triangular graphene superlattice are studied. It is shown that Dirac points with and without gaps can arise at a number of high symmetry points of the Brillouin Zone. The existence of gaps can lead to…

Mesoscale and Nanoscale Physics · Physics 2010-11-12 F. Guinea , T. Low

We consider a square lattice configuration of circular gate-defined quantum dots in an unbiased graphene sheet and calculate the electronic, particularly spectral properties of finite albeit actual sample sized systems by means of a…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 A. Pieper , R. L. Heinisch , G. Wellein , H. Fehske

We compute the dynamical polarization function for a graphene antidot lattice in the random-phase approximation. The computed polarization functions display a much more complicated structure than what is found for pristine graphene (even…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 M. H. Schultz , A. P. Jauho , T. G. Pedersen

Defects in graphene, such as vacancies or adsorbents attaching themselves to carbons, may preferentially take positions on one of its two sublattices, thus breaking the global lattice symmetry. This leads to opening a gap in the electronic…

Materials Science · Physics 2010-05-28 V. V. Cheainov , O. Syljuasen , B. L. Altshuler , V. I. Fal'ko

We review the problem of adatoms in graphene under two complementary points of view, scattering theory and strong correlations. We show that in both cases impurity atoms on the graphene surface present effects that are absent in the physics…

In contrast to the usual quantum systems which have at most a finite number of open spectral gaps if they are periodic in more than one direction, periodic quantum graphs may have gaps arbitrarily high in the spectrum. This property of…

Quantum Physics · Physics 2020-05-26 Pavel Exner , Ondřej Turek