Fully resolved currents from quantum transport calculations

We extract local current distributions from interatomic currents calculated using a fully relativistic quantum mechanical scattering formalism by interpolation onto a three-dimensional grid. The method is illustrated with calculations for Pt|Ir and Pt|Au multilayers as well as for thin films of Pt and Au that include temperature-dependent lattice disorder. The current flow is studied in the "classical"and "Knudsen"limits determined by the sample thickness relative to the mean free path λ, introducing current streamlines to visualize the results. For periodic multilayers, our results in the classical limit reveal that transport inside a metal can be described using a single value of resistivity ρ combined with a linear variation of ρ at the interface while the Knudsen limit indicates a strong spatial dependence of ρ inside a metal and an anomalous dip of the current density at the interface which is accentuated in a region where shunting is incomplete.