Transfer-matrix simulations of field emission from a metallic (5,5) carbon nanotube

We present three-dimensional simulations of field emission from an open (5,5) carbon nanotube without adsorption, by using a transfer-matrix methodology. By introducing pseudopotentials for the representation of carbon atoms and by repeating periodically a basic unit of the nanotube, band-structure effects are manifested in the distributions of energies. A representation of the band structure of the (5,5) nanotube is presented. The total-energy distributions of both the incident and field-emitted electrons contain peaks, which are related to discontinuities in the band structure or to standing waves in the carbon nanotube (a total length of 5.657 nm is considered). These peaks move to lower energies when the extraction field is increased. Such peaks should be observable in field-emission experiments.