Evaluation of junction parameters with control of carrier concentration in Bi2Sr2CaCu2O8+δ stacked junctions

The control of the critical current density (JC) and the junction resistance (RN) along the c axis of intrinsic Josephson junctions (IJJs) on a high-TC superconductor is very important for applying the IJJs to electronic devices. For controlling these junction parameters, we have clarified the relationship of JC, RN, and the carrier concentration in Bi2Sr2CaCu2O8+δ whiskers by changing the carrier concentration with an annealing process. We determined the electrical transport characteristics of the IJJs. As a result, the JC increased, and the RN decreased systematically when the carrier concentration increased. The values of JC and RN could be controlled by a change in the carrier concentration