Density functional analysis of field emission from metals

A fully self-consistent method suitable to evaluate field emission currents is newly developed on the basis of the density functional theory. This method does not require nearby counter electrode. By using this method, first we have investigated field emission currents from a biased metallic surface represented by the bare jellium model. Next, the present method has been applied successfully to the case where a sodium layer is adsorbed on the jellium surface of rs=2 bohr. We have confirmed reduction of the potential barrier and a considerable increase in field emission currents by the sodium adsorption. These analyses show the validity of our method.