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In this work we investigate the influence of a Fermi velocity modulation on the Fano factor of periodic and quasi-periodic graphene superlattices. We consider the continuum model and use the transfer matrix method to solve the Dirac-like…

Mesoscale and Nanoscale Physics · Physics 2017-11-22 Jonas R. F. Lima , Anderson L. R. Barbosa , C. G. Bezerra , Luiz Felipe C. Pereira

The electronic structure of a graphene superlattice composed by two periodic regions with different Fermi velocity, energy gap and electrostatic potential is investigated by using an effective Dirac-like Hamiltonian. It must be expected…

Materials Science · Physics 2015-04-07 Jonas R. F. Lima

We study a novel type of graphene-based superlattices formed owing to a periodic modulation of the Fermi surface. Such a modulation is possible for graphene deposited on a striped substrate made of materials with substantially different…

Mesoscale and Nanoscale Physics · Physics 2014-12-11 P. V. Ratnikov , A. P. Silin

In this work we study theoretically the electronic properties of a sheet of graphene grown on a periodic heterostructure substrate. We write an effective Dirac equation, which includes a dependence of both the band gap and the Fermi…

Materials Science · Physics 2014-11-12 Jonas R. F. Lima , F. Moraes

In this work we investigate the effects of a Fermi velocity modulation in a valley filter in graphene created by a combination of a magnetic and electric barrier. With the effective Dirac equation of the system, we use the transfer matrix…

Mesoscale and Nanoscale Physics · Physics 2020-01-22 A. R. S. Lins , Jonas R. F. Lima

The electronic structure of a single-layer graphene with a periodic Fermi velocity modulation is investigated by using an effective Dirac-like Hamiltonian. In a gapless graphene or in a graphene with a constant energy gap the modulation of…

Materials Science · Physics 2014-12-02 Jonas R. F. Lima

The Fermi velocity is one of the key concepts in the study of a material, as it bears information on a variety of fundamental properties. Upon increasing demand on the device applications, graphene is viewed as a prototypical system for…

Mesoscale and Nanoscale Physics · Physics 2012-08-21 Choongyu Hwang , David A. Siegel , Sung-Kwan Mo , William Regan , Ariel Ismach , Yuegang Zhang , Alex Zettl , Alessandra Lanzara

We study the electronic and transport properties of a graphene-based superlattice theoretically by using an effective Dirac equation. The superlattice consists of a periodic potential applied on a single-layer graphene deposited on a…

Mesoscale and Nanoscale Physics · Physics 2015-02-26 Jonas R. F. Lima

Using full-potential density functional theory (DFT) calculations, we found a small asymmetry in the Fermi velocity of electrons and holes in graphene. These Fermi velocity values and their average were found to decrease with increasing…

Mesoscale and Nanoscale Physics · Physics 2013-02-08 Harihar Behera , Gautam Mukhopadhyay

Recent studies show that periodic potentials can generate superlattice Dirac points at energies in graphene (is the Fermi velocity of graphene and G is the reciprocal superlattice vector). Here, we perform scanning tunneling microscopy and…

Mesoscale and Nanoscale Physics · Physics 2013-02-21 Hui Yan , Zhao-Dong Chu , Wei Yan , Mengxi Liu , Lan Meng , Mudan Yang , Yide Fan , Jiang Wang , Rui-Fen Dou , Yanfeng Zhang , Zhongfan Liu , Jia-Cai Nie , Lin He

Dirac materials are characterized by energy-momentum relations that resemble those of relativistic massless particles. Commonly denominated Dirac cones, these dispersion relations are considered to be their essential feature. These…

Mesoscale and Nanoscale Physics · Physics 2017-09-05 A. Diaz-Fernandez , L. Chico , J. W. Gonzalez , F. Dominguez-Adame

Electrodynamic properties of the graphene - magnetic semiconductor - graphene superlattice placed in magnetic field have been investigated theoretically in Faraday geometry with taking into account dissipation processes. Frequency and field…

Mesoscale and Nanoscale Physics · Physics 2014-12-31 Dmitry A. Kuzmin , Igor V. Bychkov , Vladimir G. Shavrov

Wave propagation control by spatial modulation of velocity has a long history in optics and acoustics. We address velocity-modulation control of electron wave propagation in graphene and other two-dimensional Dirac-electron systems,…

Mesoscale and Nanoscale Physics · Physics 2010-02-26 Arnaud Raoux , Marco Polini , Reza Asgari , A. R. Hamilton , Rosario Fazio , A. H. MacDonald

We consider systems described by the two-dimensional Dirac equation where the Fermi velocity is inhomogeneous as a consequence of mechanical deformations. We show that the mechanical deformations can lead to deflection and focusing of the…

Mesoscale and Nanoscale Physics · Physics 2021-11-23 Alonso Contreras-Astorga , Vit Jakubsky , Alfredo Raya

In recent years, graphene and other two-dimensional Dirac materials like silicene, germanene, etc. have been studied from different points of view: from mathematical physics, condensed matter physics to high energy physics. In this study,…

Mesoscale and Nanoscale Physics · Physics 2021-10-18 Anh-Luan Phan , Dai-Nam Le

We study tunneling across a strain-induced superlattice in graphene. In studying the effect of applied strain on the low-lying Dirac-like spectrum, both a shift of the Dirac points in reciprocal space, and a deformation of the Dirac cones…

Mesoscale and Nanoscale Physics · Physics 2012-05-08 F. M. D. Pellegrino , G. G. N. Angilella , R. Pucci

Using Chebyshev polynomials, we study the electronic transport properties of massless Dirac fermions in symmetrical graphene superlattice composed of three regions. Matching wavefunctions and using transfer matrix method, we explicitly…

Mesoscale and Nanoscale Physics · Physics 2018-12-27 El Bouâzzaoui Choubabi , Abdellatif Kamal , Ahmed Jellal

We study the renormalization of the Fermi velocity by the long-range Coulomb interactions between the charge carriers in the Dirac-cone approximation for the effective low-energy description of the electronic excitations in graphene at half…

High Energy Physics - Phenomenology · Physics 2015-01-13 C. Popovici , C. S. Fischer , L. von Smekal

We theoretically investigate electron transport through corrugated graphene ribbons and show how the ribbon curvature leads to an electronic superlattice with a period set by the corrugation wave length. Transport through the ribbon depends…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 A. Isacsson , L. M. Jonsson , J. M. Kinaret , M. Jonson

A transfer matrix approach is used to study the electronic transport in graphene superlattices with long-range correlated barrier spacements. By considering the low-energy electronic excitations as massless Dirac fermions, we compute by…

Mesoscale and Nanoscale Physics · Physics 2020-05-22 Anderson L. R. Barbosa , Jonas R. F. Lima , Ícaro S. F. Bezerra , Marcelo L. Lyra
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