  The charge-carrier transport properties of ultrathin metallic films are
analysed with ab-initio methods using the density functional theory (DFT) on
free-standing single crystalline slabs in the thickness range between 1 and 8
monolayers and compared with experiments for Pb films on Si(111). A strong
interplay between bandstructure, quantised in the direction normal to the
ultrathin film, charge-carrier scattering mechanisms and magnetoconduction was
found. Based on the bandstructure obtained from the DFT, we used standard
Boltzmann transport theory in two dimensions to obtain results for the
electronic transport properties of 2 to 8 monolayers thick Pb(111) slabs with
and without magnetic field. Comparison of calculations and experiment for the
thickness dependence of the dc conductivity shows that the dominant scattering
mechanism of electrons is diffuse elastic interface scattering for which the
assumption of identical scattering times for all subbands and directions, used
in this paper, is a good approximation. Within this model we can explain the
thickness dependences of the electric conductivity and of the Hall coefficient
as well as the anomalous behaviour of the first Pb layer.
