Optical phonon spectrum and the Fröhlich Hamiltonian in würtzite-type nanotubes

Abstract

Dispersion laws of the full optical phonon spectrum of a nanotube made of würtzite-typematerials as well as the corresponding Fröhlich electron–phonon interaction terms arederived and studied within the framework of the dielectric continuum model for a uniaxialcrystal. The coupling coefficients describing electron–phonon interaction are obtained in ananalytical closed form, depending on the dispersion law of the involved phononbranch. We present and discuss results of numerical calculations of optical phononspectrum and Fröhlich coupling coefficients for some chosen würtzite AlN nanotubes.Observed features, induced by the anisotropy of würtzite-type materials, are discussed.