Trigonal warping effect of carbon nanotubes
نویسندگان
چکیده
Chirality-dependent van Hove singularities ~vHs! of the one-dimensional electronic density of states ~DOS! are discussed in connection with resonant Raman spectroscopy. The effect of trigonal warping on the energy dispersion relations near the Fermi energy splits the peaks of the density of states for metallic nanotubes, and the magnitude of this effect depends on the chiral angle of the carbon nanotube. The width of the peak splitting has a maximum for metallic zigzag nanotubes, and no splitting is obtained for armchair nanotubes or semiconducting nanotubes. We also find an additional logarithmic singularity in the electronic DOS for carbon nanotubes that is related to a two-dimensional singularity, which does not depend on either the diameter or the chirality.
منابع مشابه
Probing the electronic trigonal warping effect in individual single-wall carbon nanotubes using phonon spectra
We have studied the trigonal warping effect in metallic carbon nanotubes using resonance Raman scattering and examining the G0-band profile for individual metallic single-wall carbon nanotubes. We show that the observed splitting in the G0-band phonon spectra is directly correlated with the splitting in the singularities of the joint density of electronic states, i.e., detailed information abou...
متن کاملSecondary Electron Interference from Trigonal Warping in Clean Carbon Nanotubes.
We investigate Fabry-Perot interference in an ultraclean carbon nanotube resonator. The conductance shows a clear superstructure superimposed onto conventional Fabry-Perot oscillations. A sliding average over the fast oscillations reveals a characteristic slow modulation of the conductance as a function of the gate voltage. We identify the origin of this secondary interference in intervalley an...
متن کاملStructure-assigned optical spectra of single-walled carbon nanotubes.
Spectrofluorimetric measurements on single-walled carbon nanotubes (SWNTs) isolated in aqueous surfactant suspensions have revealed distinct electronic absorption and emission transitions for more than 30 different semiconducting nanotube species. By combining these fluorimetric results with resonance Raman data, each optical transition has been mapped to a specific (n,m) nanotube structure. Op...
متن کاملSecondary electron interference from trigonal warping in clean carbon nanotubes Supplementary Material
As electrode material, a 10/40 nm Ti/Pt bilayer is patterned on top of a degenerately doped Si substrate with a 500 nm thick insulating capping layer, see Fig. S1. In order to avoid contamination of the CNT, we grow the carbon nanotube as a last fabrication step across the contact electrodes separated by a 1.2μm trench. The identification of a promising device is done solely via room temperatur...
متن کاملNonlinear magnetotransport in interacting chiral nanotubes.
Nonlinear transport through interacting single-wall nanotubes containing a few impurities is studied theoretically. Extending the Luttinger liquid theory to incorporate trigonal warping and chirality effects, we derive the current contribution Ie even in the applied voltage V and odd in an orbital magnetic field B, which is nonzero only for chiral tubes and in the presence of interactions.
متن کامل