Switching dynamics and MQT in Bi2201 intrinsic Josephson junctions

摘要

We investigate the switching dynamics of Bi2Sr1.6La0.4CuO6+delta (Bi2201) intrinsic Josephson junctions (IJJs) to clarify the effect of the strong coupling between junctions in the stack. We find that the number of junctions switching simultaneously to the finite voltage states can be tuned by changing the load resistance connected in series with IJJs. The width of the switching current distribution (SCD) becomes constant below 0.4 K indicating the crossover of switching mechanism from the thermal activation to the macroscopic quantum tunneling. The quality factors obtained based on the analysis of the SCD are in the range from 70 to 100, which implies that Bi2201 IJJs work as underdamped Josephson junctions similar to Bi2Sr2CaCu2O8+delta IJJS.