Strongly interacting Luttinger liquid state in carbon nanotubes and organic conductors

Igor Karnaukhov

Institute of Metal Physics/Department of theory of nonideal crystals, National Academy of Sciences,
Vernadsky Street, 03142 Kiev, Ukraine

The charge transport properties of carbon nanotubes have been investigates intensively over the last years since they represent an archetype of a one-dimensional (1D) systems. For metallic 1D systems, conventional Fermi-liquid theory fails due to strong correlation effects. The electronic density of states of the valence band electrons of mats of single-wall carbon nanotubes was directly monitored by angle integrated high resolution photoemission experiments. The spectral function and the temperature dependence of the intensity at the Fermi level exhibited a power low dependence with the exponents of 0.46. However, the observed exponent is much larger than the theoretical upper limit in the exact solvable Hubbard model, g =0.125, indicating that a more realistic microscopic model is required to describe the real quasi-1D systems. Such large values of the critical exponent are explained in the framework of state strongly interacting Luttinger liquid, that is realized in 1D systems with a hard-core repulsive interaction between articles. The critical exponents of the correlation functions, that describe a power law behavior of the conductance and differential conductance with respect to temperature and bias voltage, are calculated using the Bethe ansatz solution of the model and conformal field theory. The model proposed to explain the experimental data for critical exponents observed on carbon nanotubes and organic conductors.