Effect of capacitance on I‐V characteristics of overdamped Josephson junctions: Classical and quantum limits

摘要

We have considered the effect of capacitance on the I‐V characteristics of a Josephson tunnel junction in the overdamped limit. Both thermal and quantum fluctuations limits have been investigated. In the framework of the washboard‐shaped potential the quantum and thermal fluctuations determine the time spent by the particle in and out of a potential well. These characteristic times have been calculated. The results allowed the possibility of obtaining the I‐V characteristics of the junctions. It is shown that for current I smaller than the critical Ic, I‐V curves with a higher slope correspond to larger capacitance values whereas for I≫Ic the curves with smaller capacitance lie above those with larger capacitance.