• 文献标题:   Tuning the supercritical effective charge in gapless graphene via Fermi velocity modifying through the mechanical stretching
  • 文献类型:   Article
  • 作  者:   KATIN KP, KRYLOV KS, MASLOV MM, MUR VD
  • 作者关键词:   graphene, supercritical effective charge, fermi velocity, mechanical stretching, gap opening
  • 出版物名称:   DIAMOND RELATED MATERIALS
  • ISSN:   0925-9635 EI 1879-0062
  • 通讯作者地址:   Natl Res Nucl Univ MEPhI
  • 被引频次:   3
  • DOI:   10.1016/j.diamond.2019.107566
  • 出版年:   2019

▎ 摘  要

We present a theoretical study of the stretched graphene containing the Coulomb impurity. The cases of uniaxial armchair/zigzag and biaxial symmetry stretching are considered. For the uniaxial stretching, we found the gap opening with the non-monotonic dependence between the gap value and the strain. For the biaxial stretching, we observe a monotonic decreasing of Fermi velocity without the gap opening. Non-relativistic ab initio calculations of graphene electronic structure are combined with the analytical solution of relativistic Dirac equation. We found that the sheet stretching could provide a smooth fitting of Fermi velocity and, therefore, the smooth transformation of subcritical Coulomb impurity to the supercritical one.