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Exact analytic solutions for an electron in graphene interacting with external complex magnetic fields are found. The eigenvalue problem for the non-hermitian Dirac-Weyl Hamiltonian leads to a pair of intertwined Schr{\"o}dinger equations,…

Mathematical Physics · Physics 2022-03-14 DJ Fernández , JD García-Muñoz

We consider the relationship between the tight-binding Hamiltonian of the two-dimensional honeycomb lattice of carbon atoms with nearest neighbor hopping only and the 2+1 dimensional Hamiltonian of quantum electrodynamics which follows in…

Mesoscale and Nanoscale Physics · Physics 2008-11-26 V. P. Gusynin , S. G. Sharapov , J. P. Carbotte

We demonstrate that there exists a continuum Hamiltonian $H(\bf{r},\bf{p})$ that is formally the operator equivalent of the general tight-binding method, inheriting the associativity and Hermiticity of the latter operator. This provides a…

Materials Science · Physics 2019-01-16 F. Rost , R. Gupta , M. Fleischmann , D. Weckbecker , N. Ray , J. Olivares , M. Vogl , S. Sharma , O. Pankratov , S. Shallcross

Very recently, the standard description of electrons in strained graphene has been completed by the explicit inclusion of the lattice deformation. Here, the effect of these lattice corrections is taken into account to find the mechanical…

Mesoscale and Nanoscale Physics · Physics 2013-03-08 M. Oliva-Leyva , Gerardo G. Naumis

Tunnelling of electrons in graphene-based junctions is studied theoretically. Graphene is assumed to be deposited either directly on a ferromagnetic insulator or on a few atomic layers of boron nitride which separate graphene from a…

Mesoscale and Nanoscale Physics · Physics 2019-05-01 Jędrzej Tepper , Józef Barnaś

By combining continuum elasticity theory and tight-binding atomistic simulations, we work out the constitutive nonlinear stress-strain relation for graphene stretching elasticity and we calculate all the corresponding nonlinear elastic…

Mesoscale and Nanoscale Physics · Physics 2010-06-04 Emiliano Cadelano , Pier Luca Palla , Stefano Giordano , Luciano Colombo

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

In this paper, we investigated the effects of periodic external potentials on properties of charge carriers in graphene using both the first-principles method based on density functional theory (DFT) and a theoretical approach based on a…

Mesoscale and Nanoscale Physics · Physics 2013-11-27 Aihua Zhang , Zhenxiang Dai , Lei Shi , Yuan Ping Feng , Chun Zhang

This paper is devoted to development of perturbation theory for studying the properties of graphene sheet of finite size, at nonzero temperature and chemical potential. The perturbation theory is based on the tight-binding Hamiltonian and…

Strongly Correlated Electrons · Physics 2015-12-16 N. Yu. Astrakhantsev , V. V. Braguta , M. I. Katsnelson

We study the electronic properties of rippled freestanding graphene membranes under central load from a sharp tip. To that end, we develop a gauge field theory on a honeycomb lattice valid beyond the continuum theory. Based on the proper…

Mesoscale and Nanoscale Physics · Physics 2013-10-03 James V. Sloan , Alejandro A. Pacheco Sanjuan , Zhengfei Wang , Cedric Horvath , Salvador Barraza-Lopez

Using ab-initio methods, we show that the uniform deformation either leaves graphene (semi)metallic or opens up a small gap yet only beyond the mechanical breaking point of the graphene, contrary to claims in the literature based on…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 I. I. Naumov , A. M. Bratkovsky

The Dirac Hamiltonian formalism is applied to a system in $(2+1)$-dimensions consisting of a Dirac field $\psi$ minimally coupled to Chern-Simons $U(1)$ and $SO(2,1)$ connections, $A$ and $\omega$, respectively. This theory is connected to…

High Energy Physics - Theory · Physics 2016-08-22 Alfredo Guevara , Pablo Pais , Jorge Zanelli

A generalized algebra of noncommutative coordinates and momenta embracing non-Abelian gauge fields is proposed. Through a two-dimensional realization of this algebra for a gauge field including electromagnetic vector potential and two…

Mesoscale and Nanoscale Physics · Physics 2014-11-20 Omer F. Dayi , Ahmed Jellal

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

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

We consider a noncommutative description of graphene. This description consists of a Dirac equation for massless Dirac fermions plus noncommutative corrections, which are treated in the presence of an external magnetic field. We argue that,…

High Energy Physics - Theory · Physics 2014-01-16 C. Bastos , O. Bertolami , N. Dias , J. Prata

Many-body electron-electron interaction effects are theoretically considered in monolayer graphene from a continuum effective field-theoretic perspective by going beyond the standard leading-order perturbative renormalization group (RG)…

Mesoscale and Nanoscale Physics · Physics 2014-07-01 Edwin Barnes , E. H. Hwang , R. E. Throckmorton , S. Das Sarma

We present a simple derivation of a continuum Hamiltonian for bilayer graphene with an arbitrary smooth lattice deformation -- technically in a fashion parametrized by displacement fields with small gradients. We show that this subsumes the…

Mesoscale and Nanoscale Physics · Physics 2019-10-16 Leon Balents

The electronic properties of graphene under any arbitrary uniaxial strain field are obtained by an exact mapping of the corresponding tight-binding Hamiltonian into an effective one-dimensional modulated chain. For a periodic modulation,…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Gerardo G. Naumis , Pedro Roman-Taboada

We reconsider monolayer graphene in the presence of elastic deformations. It is described by the tight - binding model with varying hopping parameters. We demonstrate, that the fermionic quasiparticles propagate in the emergent 2D…

Strongly Correlated Electrons · Physics 2013-08-13 M. A. Zubkov , G. E. Volovik