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

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.