Resonant transport in single-wall armchair carbon nanotubes with local mirror-symmetry-breaking deformations

Local mirror-symmetry-breaking deformations such as flattening strongly affect electron coherent transport in single-wall armchair carbon nanotubes. Such a local deformation gives rich structures in electron transmission, such as a transmission barrier, resonances, and antiresonances. When local deformations create barriers, a finite perfect tube sandwiched between two deformed regions behaves as a quantum dot. As gate voltage varies, this nanotube device exhibits periodic resonant peak pairs in transmission, each of which results from nearly degenerate bound states of beat type. This feature of resonances is attributed to the mixing of two channels \pi] and \pi*] due to the breaking of mirror symmetries.