Manifestation of quantum confinement in transport properties of ultrathin metallic films

The influence of quantum size effect on the transport properties of ultrathin Cu and Fe films in the thickness range between 1 and 32 monolayers is studied by solving the linearized Boltzmann equation in the relaxation-time approximation using ab initio calculations within the framework of spin density functional theory.A strong manifestation of quantum confinement is found in the density of states. However, the plasma frequency shows a smooth or oscillating behavior for different film orientations. The results are in qualitative agreement to infrared-absorption experiments at Cu(111), Fe(001), and Fe(111) films.