Shape dependence of the intrinsic quantum shot noise suppression of electron field emission

This paper presents a two-dimensional nonuniform model to calculate the quantum shot noise suppression (or Fano factor) for electron field emission from a single field emitter of two different shapes: Lorentzian and prolate spheroidal. Between them, the Lorentzian field emitter has a larger shot noise suppression. For a given sharp emitter at a fixed work function, there is a minimum value of the Fano factor, which is independent of the geometrical sharpness of the emitter, and it increases with larger work function. Comparison with the one-dimensional uniform model has implied that prior results had overestimated the shot noise suppression.