The study explores perpendicular transport through macroscopicallyinhomogeneous three-dimensional disordered conductors using mesoscopic methods(real-space Green function technique in a two-probe measuring geometry). Thenanoscale samples (containing $\sim1000$ atoms) are modeled by a tight-bindingHamiltonian on a simple cubic lattice where disorder is introduced in theon-site potential energy. I compute the transport properties of: disorderedmetallic junctions formed by concatenating two homogenous samples withdifferent kinds of microscopic disorder, a single strongly disorderedinterface, and multilayers composed of such interfaces and homogeneous layerscharacterized by different strength of the same type of microscopic disorder.This allows us to: contrast resistor model (semiclassical) approach with fullyquantum description of dirty mesoscopic multilayers; study the transmissionproperties of dirty interfaces (where Schep-Bauer distribution of transmissioneigenvalues is confirmed for single interface, as well as for the stack of suchinterfaces that is thinner than the localization length); and elucidate theeffect of coupling to ideal leads (``measuring apparatus'') on the conductanceof both bulk conductors and dirty interfaces When multilayer contains aballistic layer in between two interfaces, its disorder-averaged conductanceoscillates as a function of Fermi energy. I also address some fundamentalissues in quantum transport theory--the relationship between Kubo formula inexact state representation and ``mesoscopic Kubo formula'' (which gives thezero-temperature conductance of a finite-size sample attached to twosemi-infinite ideal leads) is thoroughly reexamined by comparing their answersfor both the junctions and homogeneous samples.
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