English
Related papers

Related papers: Stable spatially discrete envelope-function model …

200 papers

The symmetries that protect massless Dirac fermions from a gap opening may become ineffective if the Dirac equation is discretized in space and time, either because of scattering between multiple Dirac cones in the Brillouin zone (fermion…

Mesoscale and Nanoscale Physics · Physics 2022-12-16 A. Donís Vela , M. J. Pacholski , G. Lemut , J. Tworzydło , C. W. J. Beenakker

The low energy excitations of graphene can be described by a massless Dirac equation in two spacial dimensions. Curved graphene is proposed to be described by coupling the Dirac equation to the corresponding curved space. This covariant…

Strongly Correlated Electrons · Physics 2009-11-13 Maria A. H. Vozmediano , Fernando de Juan , Alberto Cortijo

A way to represent the band structure that distinguishes between energy-momentum and energy-crystal momentum relationships is proposed upon the band-unfolding concept. This momentum-resolved band structure offers better understanding of the…

Materials Science · Physics 2018-07-02 Chi-Cheng Lee , Masahiro Fukuda , Yung-Ting Lee , Taisuke Ozaki

We investigate a planar heterostructure composed of two graphene films separated by a narrow-gap semiconductor ribbon. We show that there is no the Klein paradox when the Dirac points of the Brillouin zone of graphene are in a band gap of a…

Materials Science · Physics 2015-05-13 P. V. Ratnikov , A. P. Silin

We evaluate the dispersion relation for massless fermions, described by the Dirac equation, and for zero-spin bosons, described by the Klein-Gordon equation, moving in two dimensions and in the presence of a one-dimensional periodic…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 M. Barbier , F. M. Peeters , P. Vasilopoulos , J. Milton Pereira

The behavior of electrons in strained graphene is usually described using effective pseudomagnetic fields in a Dirac equation. Here we consider the particular case of a spatially constant strain. Our results indicate that lattice…

Mesoscale and Nanoscale Physics · Physics 2013-09-10 M. Oliva-Leyva , G. G. Naumis

Quantum confinement of graphene Dirac-like electrons in artificially crafted nanometer structures is a long sought goal that would provide a strategy to selectively tune the electronic properties of graphene, including bandgap opening or…

We study quantum transport and scattering of massless Dirac fermions by spatially localized static magnetic fields. The employed model describes in a unified manner the effects of orbital magnetic fields, Zeeman and exchange fields in…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 A. Zazunov , A. Kundu , A. Hütten , R. Egger

We propose a general variational fermionic many-body wavefunction that generates an effective Hamiltonian in a quadratic form, which can then be exactly solved. The theory can be constructed within the density functional theory framework,…

Strongly Correlated Electrons · Physics 2020-10-30 Xindong Wang , Xiao Chen , Liqin Ke , Hai-Ping Cheng , B. N. Harmon

A finite difference scheme for the numerical treatment of the (3+1)D Dirac equation is presented. Its staggered-grid intertwined discretization treats space and time coordinates on equal footing, thereby avoiding the notorious fermion…

Computational Physics · Physics 2015-06-09 René Hammer , Walter Pötz , Anton Arnold

In two dimensions chaotic level-statistics is expected for massless Dirac fermions in the presence of disorder. For weakly disordered graphene flakes with zigzag edges the obtained level-spacing distribution in the Dirac region is neither…

Disordered Systems and Neural Networks · Physics 2013-02-12 H. Amanatidis , I. Kleftogiannis , D. E. Katsanos , S. N. Evangelou

A finite difference scheme is presented for the Dirac equation in (1+1)D. It can handle space- and time-dependent mass and potential terms and utilizes exact discrete transparent boundary conditions (DTBCs). Based on a space- and…

Computational Physics · Physics 2014-01-17 René Hammer , Walter Pötz , Anton Arnold

Different stoichiometric configurations of graphane and graphene fluoride are investigated within density functional theory. Their structural and electronic properties are compared, and we indicate the similarities and differences among the…

Materials Science · Physics 2011-11-23 O. Leenaerts , H. Peelaers , A. D. Hernandez-Nieves , B. Partoens , F. M. Peeters

The recent discovery of methods to isolate graphene, a one-atom-thick layer of crystalline carbon, has raised the possibility of a new class of nano-electronics devices based on the extraordinary electrical transport and unusual physical…

Mesoscale and Nanoscale Physics · Physics 2008-10-02 Xu Du , Ivan Skachko , Anthony Barker , Eva Y. Andrei

We present and analyze two mathematical models for the self consistent quantum transport of electrons in a graphene layer. We treat two situations. First, when the particles can move in all the plane $\RR^2$, the model takes the form of a…

Analysis of PDEs · Mathematics 2013-10-28 Raymond El Hajj , Florian Méhats

We study the non-linear current response of a Dirac model that is coupled to two time-periodic electro-magnetic fields with different frequencies. We distinguish between incommensurable and commensurable frequencies, the latter…

Mesoscale and Nanoscale Physics · Physics 2020-11-17 Sigmund Kohler , Tobias Stauber

Two-dimensional (2D) Dirac-like electron gases have attracted tremendous research interest ever since the discovery of free-standing graphene. The linear energy dispersion and non-trivial Berry phase play the pivotal role in the remarkable…

The role of defect-induced zero-energy modes on charge transport in graphene is investigated using Kubo and Landauer transport calculations. By tuning the density of random distributions of monovacancies either equally populating the two…

Mesoscale and Nanoscale Physics · Physics 2013-05-13 Alessandro Cresti , Frank Ortmann , Thibaud Louvet , Dinh Van Tuan , Stephan Roche

The unconventional properties of graphene, with a massless Dirac band dispersion and large coherence properties, have raised a large interest for applications in nanoelectronics. In this work, we emphasize that graphene two dimensional…

Mesoscale and Nanoscale Physics · Physics 2008-08-27 Pierre Darancet , Valerio Olevano , Didier Mayou

We study the low-energy electronic transport across periodic extended defects in graphene. In the continuum low-energy limit, such defects act as infinitesimally thin stripes separating two regions where Dirac Hamiltonian governs the…

Mesoscale and Nanoscale Physics · Physics 2012-12-14 J. N. B. Rodrigues , N. M. R. Peres , J. M. B. Lopes dos Santos