Khachaturova T. Effect of the barrier electronic structure on transport characteristics of tunnel contacts with metallic electrodes

A new approach for calculating the transparency of metal-insulator-metal heterostructures is developed. It takes into account a real electronic spectrum and spatial inhomogeneity of dielectric barrier. It is shown that the dependence of tunneling conductance versus applied voltages of heterostructures with semimetal electrodes manifest an unusual W-behavior. It is proved that if the Fermi level of the tunneling structure under study is located in the lower part of the dielectric forbidden band the conductance voltage characteristic contains the negative resistance region. Within a two-band approximation the tunneling magnetoresistance in the double spin filters with ferromagnetic dielectric barriers are calculated. The obtained characteristics are in the good qualitative and quantitative agreement with experimental results. Influence of multiple Andreev reflections on current-voltage curves for Josephson structures with a spatially inhomogeneous transition layer between superconducting electrodes, elaboration of specific recommendations for creation of novel and improvement of existing devices for micro- and nanoelectronics based on the electron tunneling phenomenon in thin insulating layers. The results obtained are of significant fundamental and applied importance for further development of the physics of solid-state heterostructures with nanoscale insulating interlayers.