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We present a numerical method to compute the Landauer conductance of noninteracting two-dimensional massless Dirac fermions in disordered systems. The method allows for the introduction of boundary conditions at the ribbon edges and…

Mesoscale and Nanoscale Physics · Physics 2012-10-29 Alexis R. Hernández , Caio H. Lewenkopf

A simple and reliable finite difference approach is presented for solution of the Dirac equation eigenproblem for states confined in rotationally symmetric systems. The method sets the boundary condition for the spinor wave function…

Mesoscale and Nanoscale Physics · Physics 2019-05-08 B. Szafran , A. Mrenca-Kolasinska , D. Zebrowski

This paper presents a fast algorithm for computing transport properties of two-dimensional Dirac operators with linear domain walls, which model the macroscopic behavior of the robust and asymmetric transport observed at an interface…

Mathematical Physics · Physics 2023-05-17 Guillaume Bal , Jeremy G Hoskins , Zhongjian Wang

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

Using the method of finite differences a scheme is proposed to solve exactly the Klein-Gordon and Dirac free field equations, in a (1+1)-dimensional lattice. The hamiltonian of the Dirac field is translational invariant, hermitian, avoids…

High Energy Physics - Lattice · Physics 2007-05-23 M. Lorente

The spurious states found in numerical implementations of envelope function models for semiconductor heterostructures and nanostructures have been shown to be readily removed by employing a first-order difference scheme. This approach is…

Mesoscale and Nanoscale Physics · Physics 2015-10-29 William R. Frensley

A new method to solve the Dirac equation on a 3D lattice is proposed, in which the variational collapse problem is avoided by the inverse Hamiltonian method and the fermion doubling problem is avoided by performing spatial derivatives in…

Nuclear Theory · Physics 2017-02-14 Z. X. Ren , S. Q. Zhang , J. Meng

Representing massless Dirac fermions on a spatial lattice poses a potential challenge known as the Fermion Doubling problem. Addition of a quadratic term to the Dirac Hamiltonian circumvents this problem. We show that the modified…

Mesoscale and Nanoscale Physics · Physics 2015-09-15 K. M. Masum Habib , Redwan N. Sajjad , Avik W. Ghosh

The spectrum of massless Dirac fermions on the surface of a topological insulator in a perpendicular magnetic field $B$ contains a $B$-independent "zeroth Landau level", protected by chiral symmetry. If the Dirac equation is discretized on…

Mesoscale and Nanoscale Physics · Physics 2023-08-25 A. Donís Vela , G. Lemut , J. Tworzydło , C. W. J. Beenakker

Electron properties of graphene are described in terms of Dirac fermions. Here we thoroughly outline the elastic scattering theory for the two-dimensional massive Dirac fermions in the presence of an axially symmetric potential. While the…

Mesoscale and Nanoscale Physics · Physics 2011-11-10 D. S. Novikov

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

I. Introduction II. Two-dimensional lattice fermions III. Methods to avoid fermion doubling (sine dispersion, sine plus cosine dispersion, staggered lattice dispersion, linear sawtooth dispersion, tangent dispersion) IV. Topologically…

Mesoscale and Nanoscale Physics · Physics 2023-07-19 C. W. J. Beenakker , A. Donis Vela , G. Lemut , M. J. Pacholski , J. Tworzydlo

We study the DC transport of finite graphene samples with random gap. Using Dirac fermions to describe the low-energy physics near the Dirac point, we employ a generalized Drude form for the conductivity. The latter is constant for a…

Mesoscale and Nanoscale Physics · Physics 2010-06-14 K. Ziegler , A. Sinner

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

The spatial discretization of the single-cone Dirac Hamiltonian on the surface of a topological insulator or superconductor needs a special "staggered" grid, to avoid the appearance of a spurious second cone in the Brillouin zone. We adapt…

Mesoscale and Nanoscale Physics · Physics 2021-12-15 M. J. Pacholski , G. Lemut , J. Tworzydło , C. W. J. Beenakker

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

We address in this work the question of the discretization of two-dimensional periodic Dirac Hamiltonians. Standard finite differences methods on rectangular grids are plagued with the so-called Fermion doubling problem, which creates…

Computational Physics · Physics 2020-06-01 H. Chen , O. Pinaud , M. Tahir

The Nielsen-Ninomiya theorem, dubbed `fermion-doubling', poses a problem for the naive discretization of a single (massless) Dirac cone on a two-dimensional surface. The inevitable appearance of an additional, unphysical fermionic mode can,…

Mesoscale and Nanoscale Physics · Physics 2023-06-21 Alexander Ziesen , Ion Cosma Fulga , Fabian Hassler

To solve the Dirac equation with the finite difference method, one has to face up to the spurious-state problem due to the fermion doubling problem when using the conventional central difference formula to calculate the first-order…

Nuclear Theory · Physics 2022-11-30 Ying Zhang , Yuxuan Bao , Jinniu Hu , Hong Shen

We develop a hybrid spatial discretization for the wave equation in second order form, based on high-order accurate finite difference methods and discontinuous Galerkin methods. The hybridization combines computational efficiency of finite…

Numerical Analysis · Mathematics 2022-10-26 Siyang Wang , Gunilla Kreiss
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