• 文献标题:   Worm-graphene: A two-dimensional orthorhombic carbon semimetal with massless Dirac fermion
  • 文献类型:   Article
  • 作  者:   BHATTACHARYA D, JANA D
  • 作者关键词:   dft, dirac fermion, electronic band structure, tightbinding calculation, optical response
  • 出版物名称:   APPLIED SURFACE SCIENCE
  • ISSN:   0169-4332 EI 1873-5584
  • 通讯作者地址:  
  • 被引频次:   3
  • DOI:   10.1016/j.apsusc.2022.152457 EA FEB 2022
  • 出版年:   2022

▎ 摘  要

Low energy Dirac material of carbon other than graphene has always enthralled researchers for their unique properties. Based on first-principles calculation we propose a carbon polymorph identified by the predominance of a Dirac cone in the contiguity of the Fermi level in the Two-dimensional domain. Moreover, the stable pristine structure known as Worm-graphene involves six non-equivalent carbon atoms to effectuate an atomic density 0.372 atoms/& ANGS;(2) which is close to graphene. The Dirac cone exhibits anisotropic Fermi velocity with 6.85 x 10(5) m/s being its highest value. Besides, simple tight-binding Hamiltonian can be formulated to express the origin of the Dirac cone. Interestingly, strain resilient semimetallic behavior with robust Dirac cone of the system can be validated within 10% compressive to 10% tensile strain. Further, the material also possesses anisotropic In-plane Young's modulus unlike graphene. Appreciable degree of spin-polarization due to monovacancy defect can be established from induced magnetic moment. Additionally, nanotubes rolled-up from this sheet can be both semimetallic or semiconducting depending on the rolling direction. Free standing Worm-graphene sheet shows strikingly different optical response compared to graphene. Two collective oscillations of the system within visible range happen to be the distinguishing trait.