  The double quantum dot system with single-walled metallic armchair carbon
nanotube leads has been studied using Non-equilibrium Green function in the
Keldysh formalism. The effect of relative spacing between the energy levels of
the dots, interdot tunneling matrix-element, interdot Coulomb interaction and
van-Hove singularities in density of states characteristics of
quasi-one-dimensional carbon nanotube leads on the conductance of the double
quantum dot system has been studied. The conductance and dot occupancies are
calculated at finite temperature. It is observed that the density of states of
the carbon nanotube leads play a significant role in determining the
conductance profile. In particular, whenever the chemical potential of the
isolated double quantum dot system is aligned with the position of a van-Hove
singularity in the density of states of armchair carbon nanotube leads, the
height of the corresponding conductance peak falls considerably. It is further
observed that the suppression in the heights of the alternate peaks depends on
the relative positions of the energy levels of the dots and their magnitude of
separation.
