Electrostatic excitations in carbon nanotubes including many-electron effects

Abstract

Electrostatic excitations in single-walled carbon nanotubes are investigated taking into account both the many-electron effects of exchange and correlations and the Fermi degeneracy pressure. Quantum hydrodynamics equations for electrons and ions are employed and solved by using the Fourier transformation technique to obtain the dispersion equation relevant to the cylindrical geometry of tubules. The result shows the existence of low-frequency quantum ion-acoustic excitations exhibiting dispersion due to electron quantum effects. The electron Fermi degeneracy in the range of quantum ion-acoustic excitations turns out to be more pronounced compared to electron exchange and correlation effects. The results are explained numerically for typical systems to reveal the role of quantum degeneracy, geometrical parameters and electron exchange and correlation effects in the wave dynamics.