The coherent transmission properties of armchair SWNTs with finite length are studied with the help of real space Green's function method. In the linear conductance study, we find that SWNTs indeed act as genuine quantum wires: the conductance peak occurs in existence of resonant tunneling through a discrete electron level that is aligned with the Fermi energy Ef of the electrodes. The doubling of the conductance peaks observed in a recent experiment is numerically verified. We also find that there exist negative differential conductance region for larger bias voltage and similar transmission behavior for armchair SWNTs in the non-linear conductance study.
ASJC Scopus subject areas