Relationship between Critical Current Fluctuation of Superconducting Bicrystal Junction and Junction Parameters

Critical current fluctuation of bicrystal junctions is estimated from the 1/ f flux noise of the superconducting quantum interference device (SQUID) at T =77 K. The relationships between the current fluctuation and junction parameters, such as critical current I o and resistance R , are obtained. The obtained parameter dependence can be well explained by using the parameter dependence of the resistance fluctuation reported by Marx and Gross [Appl. Phys. Lett. 70, 120 (1997)] and the relationship between I o and R obtained for the present junctions. The agreement indicates that the critical current fluctuation is correlated with the resistance fluctuation through the relationship between I o and R .