Developing an approach based on the formation of YBa$_2$Cu$_3$O$_x$–interlayer–YBa$_2$Cu$_3$O$_x$ epitaxial structures with high current-carrying ability

An approach based on the formation of YBa$_2$Cu$_3$O$_x$–interlayer–YBa$_2$Cu$_3$O$_x$ multilayer epitaxial structures with high current-carrying ability is proposed. The use of interlayers representing simple cubic oxides (SrTiO$_3$ and CeO$_2$) allows the growth of crystal defects during the formation of a high-temperature superconductor (HTS) layer to be stopped. The phenomenon of current transfer through 10- to 50-nm-thick interlayers has been discovered. Using the proposed approach, it is possible to increase the current-carrying ability in proportion to the number of HTS layers in the structure. This in principle solves the problem of critical current-density degradation with increasing thickness of YBa$_2$Cu$_3$O$_x$ layer.