Metal-semiconductor transition and Fermi velocity renormalization in metallic carbon nanotubes

Yan Li, Umberto Ravaioli, Slava V. Rotkin

Research output: Contribution to journalArticlepeer-review

18 Scopus citations

Abstract

Angular perturbations modify the band structure of armchair (and other metallic) carbon nanotubes by breaking the tube symmetry and may induce a metal-semiconductor transition when certain selection rules are satisfied. The symmetry requirements apply for both the nanotube and the perturbation potential, as studied within a nonorthogonal π -orbital tight-binding method. Perturbations of two categories are considered: an on-site electrostatic potential and a lattice deformation which changes the off-site hopping integrals. Armchair nanotubes are proved to be robust against the metal-semiconductor transition in second-order perturbation theory due to their high symmetry, but can develop a nonzero gap by extending the perturbation series to higher orders or by combining potentials of different types. An assumption of orthogonality between π orbitals is shown to lead to an accidental electron-hole symmetry and extra selection rules that are weakly broken in the nonorthogonal theory. These results are further generalized to metallic nanotubes of arbitrary chirality.

Original languageEnglish (US)
Article number035415
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume73
Issue number3
DOIs
StatePublished - Feb 27 2006

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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