Dynamical Structure Factors of Single-Walled Carbon Nanotubes by Means of Molecular Dynamics Calculation

Abstract

For ( n , n ) single-walled carbon nanotubes of the so-called armchair type , size and temperature dependence of dynamical structure factors at the zone center and zone boundary have been studied by molecular dynamics simulations using an order- N tight-binding method. Dynamical structure factors have been calculated through the Fourier transform of the time correlation function of the particle density obtained from molecular dynamics simulation results. This scheme allows a non-perturbative calculation of temperature-dependent anharmonic effects. It has been shown that the dynamical structure factors of the transverse optical mode at the zone center strongly depend on diameter of carbon nanotubes of the armchair type in good agreement with the results by the lattice dynamics calculation based on C-C force constants. It has been furthermore expected that a frequency shift of the longitudinal optical mode at the zone boundary with increasing temperature is much larger than that of the transverse optical mo...