title: Exciton effect in deformed carbon nanotubes.
abstract: The exciton states in deformed single-walled carbon nanotubes (SWNTs), under two kinds of strain, i.e., uniaxial and torsional, are theoretically studied in the Su-Schrieffer-Heeger (SSH) model, supplemented by long-range Coulomb interactions. It is found that for semiconducting zigzag tubes, the exciton binding energy E(b) and the (quasi-)continuum edge E(c) are very sensitive to the uniaxial strain, but not to the torsional one, showing two different kinds of variation behaviour of E(b) with increasing uniaxial strain, of which one decreases monotonically, and the other first increases and then decreases. Additionally, the excitons in torsionally distorted armchair tubes and uniaxially strained metallic zigzag tubes have also been studied, showing increased E(b) and E(c) with increasing strain.
authors.affiliation: Group of Computational Condensed Matter Physics, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Guili
authors.initials: G
authors.lastname: Yu
authors.forename: Yonglei
authors.initials: Y
authors.lastname: Jia
authors.forename: Jinming
authors.initials: J
authors.lastname: Dong