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The local current flow through three small aromatic carbon molecules, namely benzene, naphthalene and anthracene, is studied. Applying density functional theory and the non-equilibrium Green's function method for transport, we demonstrate…

The eigenmodes and the vibrational density of states of the ground state configuration of graphene clusters are calculated using atomistic simulations. The modified Brenner potential is used to describe the carbon-carbon interaction and…

Materials Science · Physics 2013-01-29 Sandeep Kumar Singh , F. M. Peeters

We provide numerical evidence that electronic pre-turbulent phenomena in graphene could be observed, under current experimental conditions, through detectable current fluctuations, echoing the detachment of vortices past localized…

Mesoscale and Nanoscale Physics · Physics 2012-02-01 M. Mendoza , H. J. Herrmann , S. Succi

Effective quantum field theoretical continuum models for graphene are investigated. The models include a complex scalar field and a vector gauge field. Different gauge theories are considered and their gap patterns for the scalar, vector,…

Materials Science · Physics 2011-05-27 O. Oliveira , C. E. Cordeiro , A. Delfino , W. de Paula , T. Frederico

Elastic deformations of graphene can significantly change the flow paths and valley polarization of the electric currents. We investigate these phenomena in graphene nanoribbons with localized out-of-plane deformations by means of…

Mesoscale and Nanoscale Physics · Physics 2019-03-12 Thomas Stegmann , Nikodem Szpak

Confinement of electrons in graphene to make devices has proven to be a challenging task. Electrostatic methods fail because of Klein tunneling, while etching into nanoribbons requires extreme control of edge terminations, and bottom-up…

Mesoscale and Nanoscale Physics · Physics 2018-04-03 Y. Wu , D. Zhai , C. Pan , B. Cheng , T. Taniguchi , K. Watanabe , N. Sandler , M. Bockrath

We propose a model describing the evolution of the free electron current density in graphene. Based on the concept of Mp-branes, we perform the analysis using the difference between curvatures of parallel and antiparallel spins. In such a…

General Relativity and Quantum Cosmology · Physics 2017-07-26 Alireza Sepehri , Richard Pincak , Kazuharu Bamba , Salvatore Capozziello , Emmanuel N. Saridakis

The Green functions play a big role in the calculation of the local density of states of the carbon nanostructures. We investigate their nature for the variously oriented and disclinated graphene-like surface. Next, we investigate the case…

Mesoscale and Nanoscale Physics · Physics 2015-11-10 J. Smotlacha , R. Pincak , M. Pudlak

In the field of condensed matter, graphene plays a central role as an emerging material for nanoelectronics. Nevertheless, graphene is a semimetal, which constitutes a severe limitation for some future applications. Therefore, a lot of…

Mesoscale and Nanoscale Physics · Physics 2018-10-24 S. Zhao , J. Lavie , L. Rondin , L. Orcin-Chaix , C. Diederichs , Ph. Roussignol , Y. Chassagneux , C. Voisin , K. Müllen , A. Narita , S. Campidelli , J. S. Lauret

Graphene has generated a lot of research interest due to its special properties, which include a hydrodynamic regime. It is not yet clear however which boundary condition such a hydrodynamic current flow satisfies. The aim of this paper is…

Mesoscale and Nanoscale Physics · Physics 2015-09-24 Glenn Wagner

Thanks to its intrinsic ability to preserve spin coherence, graphene is a prime material for spintronics. In this review article, we summarize recent achievements related to spintronics in graphene quantum dots and motivate this field from…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 Matthias Droth , Guido Burkard

The current flow along the boundary of graphene stripes in a perpendicular magnetic field is studied theoretically by the nonequilibrium Green's function method. In the case of specular reflections at the boundary, the Hall resistance shows…

Mesoscale and Nanoscale Physics · Physics 2015-11-13 Thomas Stegmann , Axel Lorke

This paper reviews the current status of graphene transistors as potential supplement to silicon CMOS technology. A short overview of graphene manufacturing and metrology methods is followed by an introduction of macroscopic graphene field…

Mesoscale and Nanoscale Physics · Physics 2009-11-25 Max C. Lemme

The electronic states of an electrostatically confined cylindrical graphene quantum dot and the electric transport through this device are studied theoretically within the continuum Dirac-equation approximation and compared with numerical…

Mesoscale and Nanoscale Physics · Physics 2011-08-12 G. Pal , W. Apel , L. Schweitzer

We describe the numerical modeling of current flow in graphene heterojunctions, within the Keldysh Landauer Non-equilibrium Green's function (NEGF) formalism. By implementing a $k$-space approach along the transverse modes, coupled with…

Mesoscale and Nanoscale Physics · Physics 2013-07-02 Redwan N. Sajjad , Carlos Polanco , Avik W. Ghosh

We assess the potential of two-terminal graphene-hBN-graphene resonant tunneling diodes as high-frequency oscillators, using self-consistent quantum transport and electrostatic simulations to determine the time-dependent response of the…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 J. Gaskell , L. Eaves , K. S. Novoselov , A. Mishchenko , A. K. Geim , T. M. Fromhold , M. T. Greenaway

We theoretically analyse the possibility to electrostatically confine electrons in circular quantum dot arrays, impressed on contacted graphene nanoribbons by top gates. Utilising exact numerical techniques, we compute the scattering…

Mesoscale and Nanoscale Physics · Physics 2016-04-21 Holger Fehske , Georg Hager , Andreas Pieper

Quantum-critical states of diverse strongly correlated systems are predicted to feature universal collision-dominated transport resembling that of viscous fluids. However, investigation of these phenomena has been hampered by the lack of…

Mesoscale and Nanoscale Physics · Physics 2016-05-20 Leonid Levitov , Gregory Falkovich

We study the stability and structure of vortices emerging in two-dimensional quantum dots in high magnetic fields. Our results obtained with exact diagonalization and density-functional calculations show that vortex structures can be found…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 H. Saarikoski , S. M. Reimann , E. Rasanen , A. Harju , M. Puska

In contrast to graphene which is a gapless semiconductor, graphane, the hydrogenated graphene, is a semiconductor with an energy gap. Together with the two-dimensional geometry, unique transport features of graphene, and possibility of…

Materials Science · Physics 2010-01-04 Behnaz Gharekhanlou , Sina Khorasani