  Dynamical mean field theory is employed to calculate the properties of
multilayered inhomogeneous devices composed of semi-infinite metallic lead
layers coupled via barrier planes that are made from a strongly correlated
material (and can be tuned through the metal-insulator Mott transition). We
find that the Friedel oscillations in the metallic leads are immediately frozen
in and don't change as the thickness of the barrier increases from one to
eighty planes. We also identify a generalization of the Thouless energy that
describes the crossover from tunneling to incoherent Ohmic transport in the
insulating barrier. We qualitatively compare the results of these
self-consistent many-body calculations with the assumptions of
non-self-consistent Landauer-based approaches to shed light on when such
approaches are likely to yield good results for the transport.
