Chirality effect on carbon nanotube electron resonators

The quantum conductance oscillations of metallic single-walled carbon nanotube (SWNT) electron resonators with different chirality have been studied numerically. It is found that the slow oscillation background as well as fast conductance oscillations are intrinsic properties of SWNT electron resonators. All metallic SWNT except zigzag type electron resonators can present slow conductance oscillations background, whose oscillation period is increase as the chiral angle decrease, and the zigzag type SWNT resonators don't show the slow oscillation background. For the armchair SWNT resonators the slow oscillation background have distinctly different transport behavior depending on whether the length of the tube is commensurate with a (3N + 1) rule, with N the number of basic carbon repeat units along the nanotube length.