The frequency dependence of carbon nanotube (CNT) first hyperpolarizability has been studied. A code for quantitative estimation based on the sum over states (SOS) method has been written and calculations performed on a symmetrized basis. The main advantage of performing SOS calculations with symmetrized eigenfunctions relies on the direct identification of the essential channels that give a contribution to first hyperpolarizability. Although the method calculates hyperpolarizability both for metallic and semiconducting chiral CNTs, as an explicative example, results of calculation for the (4,1) metallic chiral topology are reported together with an analysis of the transitions responsible for resonant enhancements. The role played by CNT electron statistics is investigated in detail: results of simulations demonstrate that the ratio of the resonant peaks can be interpreted as a signature of a quasi-Luttinger or Fermi liquid regime. Copyright © 2006 John Wiley & Sons, Ltd.
All Science Journal Classification (ASJC) codes
De Dominicis, L., & Fantoni, R. (2006). Effects of electrons statistic on carbon nanotubes hyperpolarizability frequency dependence determined with sum over states method. Journal of Raman Spectroscopy, 37(6), 669 - 674. https://doi.org/10.1002/jrs.1490