  We predict shot noise enhancement in defect-free carbon nanotube field-effect
transistors through a numerical investigation based on the self-consistent
solution of the Poisson and Schrodinger equations within the non-equilibrium
Green functions formalism, and on a Monte Carlo approach to reproduce injection
statistics. Noise enhancement is due to the correlation between trapping of
holes from the drain into quasi-bound states in the channel and thermionic
injection of electrons from the source, and can lead to an appreciable Fano
factor of 1.22 at room temperature.
