Universal transition between inductive and capacitive admittance of metallic single-walled carbon nanotubes

Abstract

We theoretically investigate the subterahertz ac response of submicron metallic single-walled carbon nanotube connected to electrodes using the nonequilibrium Green's-function method. We find that the ac response shows remarkable chirality dependence in the presence of the contact resistance at the nanotube/electrode interfaces: the susceptance is classified into three categories with respect to the tube length for armchair nanotubes while it is independent of the tube length for zigzag nanotubes. Moreover, the susceptance changes from inductive to capacitive as the contact resistance increases, and the inductive-capacitive transition occurs universally at the quantum resistance, $h/{e}^{2}$, irrespective of tube chirality and length. We give an account of the universal transition using a simple resonant tunneling model.