• 文献标题:   Hybrid matrix method for stable numerical analysis of the propagation of Dirac electrons in gapless bilayer graphene superlattices
  • 文献类型:   Article
  • 作  者:   BRIONESTORRES JA, PERNASSALOMON R, PEREZALVAREZ R, RODRIGUEZVARGAS I
  • 作者关键词:   gapless bilayer graphene, superlattice, transmittance, numerical instabilitie, hybrid matrix method, coefficient transfer matrix method
  • 出版物名称:   SUPERLATTICES MICROSTRUCTURES
  • ISSN:   0749-6036
  • 通讯作者地址:   Univ Autonoma Zacatecas
  • 被引频次:   4
  • DOI:   10.1016/j.spmi.2016.03.015
  • 出版年:   2016

▎ 摘  要

Gapless bilayer graphene (GBG), like monolayer graphene, is a material system with unique properties, such as anti-Klein tunneling and intrinsic Fano resonances. These properties rely on the gapless parabolic dispersion relation and the chiral nature of bilayer graphene electrons. In addition, propagating and evanescent electron states coexist inherently in this material, giving rise to these exotic properties. In this sense, bilayer graphene is unique, since in most material systems in which Fano resonance phenomena are manifested an external source that provides extended states is required. However, from a numerical standpoint, the presence of evanescent-divergent states in the eigenfunctions linear superposition representing the Dirac spinors, leads to a numerical degradation (the so called Omega d problem) in the practical applications of the standard Coefficient Transfer Matrix (K) method used to study charge transport properties in Bilayer Graphene based multi-barrier systems. We present here a straightforward procedure based in the hybrid compliance-stiffness matrix method (H) that can overcome this numerical degradation. Our results show that in contrast to standard matrix method, the proposed H method is suitable to study the transmission and transport properties of electrons in GBG superlattice since it remains numerically stable regardless the size of the superlattice and the range of values taken by the input parameters: the energy and angle of the incident electrons, the barrier height and the thickness and number of barriers. We show that the matrix determinant can be used as a test of the numerical accuracy in real calculations. (C) 2016 Elsevier Ltd. All rights reserved.