Impact of band structure on wave function dissipation in field emission resonance

Abstract

We demonstrated on Ag(111) and Ag(100) surfaces that the reciprocal of the field emission resonance (FER) linewidth, which is proportional to the mean lifetime of resonant electrons in FER, may vary with the electric field. The variation on Ag(111) was nearly smooth, whereas that on Ag(100) was sporadic and fluctuated remarkably. This drastic difference can be explained through their dissimilar projected bulk band structures and the ensemble interpretation of quantum mechanics, according to which all resonant electrons are governed by a single wave function (WF). Ag(100) has an energy gap above its vacuum level, whereas Ag(111) does not. Consequently, the dissipation rate of the WF, which is relevant to the FER linewidth, on Ag(111) was almost stable, whereas that on Ag(100) fluctuated. The fluctuation originated from the quantum trapping effect and surface dipole layer (SDL) on Ag(100) surface. Through FER linewidth, we also demonstrated that SDLs of Cu(100) and Ag(100) are different.