Characteristics of thin-film-type Josephson junctions using Bi2Sr2CaCu2Ox/Bi2Sr2CuOy/Bi2Sr2CaCu2Oz structure

摘要

Investigation of sandwich-type Josephson junctions using a Bi$-2$/Sr$-2$/CaCu$-2$/O$- x$//Bi$-2$/Sr$-2$/CuO$-y$//Bi$-2$/Sr$-2$/CaCu$-2$/O$-z$/ (BSCCO/BSCO/BSCCO) structure. The barrier layer (BSCO) has crystalline structure similar to that of superconducting electrodes (BSCCO). Moreover, the BSCO film was conductive even at 4.2 K. The junctions exhibited S/N/S type I-V characteristics. The clear Shapiro steps appeared under microwave radiation. The values of current step height induced by the radiation oscillated with electric power. The I$-c$/ value changed in proportion to (1-T/T$-c$/)$+2$/ near T$-c$/.