The theory of tunneling in normal metal/d-type superconductor 2D-Structures

A sequential theoretical analysis is performed of tunneling in normal metal /d-type superconductor structures which contain scattering centers in the i nterlayer between a normal metal and a superconductor. As a result, it is d emonstrated that the presence of a scattering center inside an insulator in terlayer leads to partial suppression of previously predicted anomalously h igh values of conductance in the low-voltage region (zero bias anomaly (ZBA )). In so doing, the inclusion of the "interference" term in the current op erator (interference of tunneling through a scattering center with direct p otential tunneling) results in the suppression of ZBA. The predicted effect is virtually independent both of the position of the scattering center in the interlayer and of the shape of the resonance curve of scattering (which is Lorentzian in the case of resonance tunneling through the scattering ce nter). (C) 2001 MAIK "Nauka/ Interperiodica".