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An analytical study of low-energy electronic excited states in an uniformly strained graphene is carried out up to second-order in the strain tensor. We report an new effective Dirac Hamiltonian with an anisotropic Fermi velocity tensor,…

Mesoscale and Nanoscale Physics · Physics 2017-08-18 Maurice Oliva-Leyva , Chumin Wang

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

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

Nonuniform strain in graphene induces a position dependence of the Fermi velocity, as recently demonstrated by scanning tunnelling spectroscopy experiments. In this work, we study the effects of a position-dependent Fermi velocity on the…

Mesoscale and Nanoscale Physics · Physics 2018-07-09 M. Oliva-Leyva , J. E. Barrios-Vargas , Chumin Wang

Electron group velocity for graphene under uniform strain is obtained analitically by using the Tight-Binding approx- imation. Such closed analytical expressions are useful in order to calculate electronic, thermal and optical properties of…

Mesoscale and Nanoscale Physics · Physics 2016-02-17 Wilfrido A. Gómez-Arias , Gerardo G. Naumis

We consider the effect of uniaxial strain on ballistic transport in graphene, across single and multiple tunneling barriers. Specifically, we show that applied strain not only shifts the position of the Dirac points in reciprocal space, but…

Mesoscale and Nanoscale Physics · Physics 2011-11-04 F. M. D. Pellegrino , G. G. N. Angilella , R. Pucci

We study uniaxially strained graphene under the influence of non-uniform magnetic fields perpendicular to the material sample with a coordinate independent strain tensor. For that purpose, we solve the Dirac equation with anisotropic Fermi…

Strongly Correlated Electrons · Physics 2018-06-12 Yajaira Concha Sanchez , Adolfo Huet , Alfredo Raya , David Valenzuela

We study the influence of a localized Gaussian deformation on massless Dirac fermions confined to a two-dimensional curved surface. Both in-plane and out-of-plane displacements are considered within the framework of elasticity theory. These…

Mesoscale and Nanoscale Physics · Physics 2026-02-09 Samuel B. B. Almeida , J. E. G. Silva , C. A. S. Almeida

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

Within the tight binding approximation, we study the dependence of the electronic band structure and of the optical conductivity of a graphene single layer on the modulus and direction of applied uniaxial strain. While the Dirac cone…

Mesoscale and Nanoscale Physics · Physics 2010-01-15 F. M. D. Pellegrino , G. G. N. Angilella , R. Pucci

The low-energy electronic properties of strained graphene are usually obtained by transforming the bond vectors according to the Cauchy-Born rule. In this work, we derive a new effective Dirac Hamiltonian by assuming a more general…

Mesoscale and Nanoscale Physics · Physics 2018-07-09 Maurice Oliva-Leyva , Chumin Wang

We investigate the effect of an applied uniaxial strain on the ferromagnetic instability due to long- range Coulomb interaction between Dirac fermions in graphene. In case of undeformed graphene the ferromagnetic exchange instability occurs…

Strongly Correlated Electrons · Physics 2013-04-30 Anand Sharma , Valeri N. Kotov , Antonio H. Castro Neto

The density of states and the AC conductivity of graphene under uniform strain are calculated using a new Dirac Hamiltonian that takes into account the main three ingredients that change the electronic properties of strained graphene: the…

Mesoscale and Nanoscale Physics · Physics 2014-06-02 M. Oliva-Leyva , Gerardo G. Naumis

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

We use a symmetry approach to construct a systematic derivative expansion of the low energy effective Hamiltonian modifying the continuum Dirac description of graphene in the presence of non-uniform elastic deformations. We extract all…

Mesoscale and Nanoscale Physics · Physics 2015-05-26 Juan L. Mañes , Fernando de Juan , Mauricio Sturla , María A. H. Vozmediano

We describe the lattice deformation in graphene under strain effect by considering the spacial-momenta coordinates do not commute. This later can be realized by introducing the star product to end up with a generalized Heisenberg algebra.…

Mesoscale and Nanoscale Physics · Physics 2020-12-02 Ahmed Jellal

We investigate the spin-dependent transport properties of a ferromagnetic/strained/normal graphene junctions with central region subjected to a magnetic field $B$. An analytical approach, based on Dirac equation, is implemented to obtain…

Mesoscale and Nanoscale Physics · Physics 2019-09-04 Youness Zahidi , Ilham Redouani , Ahmed Jellal , Hocine Bahlouli

We analyze the effect of tensional strain in the electronic structure of graphene. In the absence of electron-electron interactions, within linear elasticity theory, and a tight-binding approach, we observe that strain can generate a bulk…

Materials Science · Physics 2009-07-15 Vitor M. Pereira , A. H. Castro Neto , N. M. R. Peres

The effect of strain on the Landau levels (LLs) spectra in graphene is studied, using an effective Dirac-like Hamiltonian which includes the distortion in the Dirac cones, anisotropy and spatial-dependence of the Fermi velocity induced by…

Materials Science · Physics 2015-04-27 Y. Betancur-Ocampo , M. E. Cifuentes-Quintal , G. Cordourier-Maruri , R. de Coss

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
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