Interface disorder and transport properties in tunnel junctions

A number of newly developed experimental techniques and theoretical insights have made it possible to investigate the electronic transport properties of conductors at the atomic scale. The field is rapidly evolving and establishes concepts and insights that can be the basis of a future technology molecular electronics. Ab initio electronic structure calculations offer the opportunity to investigate the transport properties of atomic-sized nanocontacts without any free parameters. The nanocontacts are modeled by atomic chains separating two semi-infinite metallic or magnetic leads. A first-principle screened Korrigna-Kohn-Rostoker method is used to calculate the electronic properties of the systems, treating the leads and atomic chains on the same footing without any model parameters. The calculations are based on density functional theory. The transport properties are discussed in terms of ballistic transport. The Landauer formalism is applied to investigate the conductance and magnetoresistance (MR).