Long periodic oscillation of electronic properties in capped finite-length armchair carbon nanotubes

摘要

Confinement boundary effects, coupled with quantum size effects, on the electronic properties of capped armchair single-walled carbon nanotubes are investigated by use of the tight-binding method. We observe a long periodic oscillation (LPO) behavior of energy gap, except for the conventional short periodic oscillation (SPO) behavior, with the length of carbon nanotube. Different from the intrinsic SPO, the period of LPO is deeply dependent on the topological structure of the closure, but is less related to the tube diameter. It is shown that the LPO behavior results from a closure-induced shift of allowed wave vectors perpendicular to the tube axis.