2005/11/16 by Yan Li, Slava V. Rotkin, Umberto Ravaioli · 18 citations
Materials Science · Physics and Astronomy · #Atomic orbital #Boron and Carbon Nanomaterials Research #Carbon Nanotubes in Composites #Carbon nanotube #Condensed matter physics #Electron #Fermi level #Graphene research and applications #Lattice (music) #Materials science #Nanotechnology #Perturbation theory (quantum mechanics) #Physics #Quantum mechanics #Renormalization #Semiconductor #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.73.035415
published in Physical Review B 73(3) (American Physical Society) · Submitted to Phys. Rev. B, 23 pages, 4 figures
arxiv created 2005/11/16 · openalex publication_date 2006/01/09 · openalex created_date 2016/06/24 · arxiv updated 2021/07/02 · openalex updated_date 2026/08/05
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 \ensuremathπ-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 \ensuremathπ 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.