ИСТИНА

Recent theoretical studies of coherent charge transport in junctions involving multiband superconductors and in structures with topological materials with induced superconductivity are reported [1]. Specifically, we consider structures with a high-temperature superconducting iron-based pnictides (FeBS), and hetreostructures which are formed of a thin metal layer with spin–orbit coupling or 2D topological insulator HgTe in contact with an s-wave superconductor. The theoretical analysis is performed in frameworks of our unified approach based on the tight-binding method and boundary conditions obtained for it. This approach makes it possible to take into account a complex nonparabolic and anisotropic spectrum of normal excitations in unconventional superconducting materials and their multiband character, as well as unusual types of symmetries of the superconducting order parameter in them. The method of calculations and the results are presented for the conductivities of junctions between a normal metal and multiband superconductor or the topological material, as well as for the Josephson current. Comparison with the experiment for the junction with FeBS was performed and an experiment is proposed to test our theoretical results for .structures with a metal with spin-orbit interaction with induced superconductivity.