Experimental study of the effect of silver on the characteristics of a bicrystalline transition of an HTS detector

The study is aimed at studying the effect of the silver film on the characteristics of the bicrystalline transition in high-temperature superconducting (HTS) detectors based on YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO). The paper analyzes five chips manufactured in different technological cycles. There are three types of structures of Josephson detectors with log periodic antennas of different configurations on each chip. The main attention is paid to the comparison of critical current, normal resistance and characteristic voltage at temperatures of 4 and 77 K. The results showed that structures with the same geometric dimensions of the Josephson junction exhibit significant differences in parameters. It is established that the main reason for the parameter deviations is the proximity of the silver layer to the bicrystalline boundary, which leads to contamination of the barrier and changes in the properties of the transition.