Finite size and current effects on IV characteristics of Josephson junction arrays

The effects of finite size and of finite current on the current-voltage characteristics of Josephson junction arrays are studied both theoretically and by numerical simulations. The crossover from nonlinear to linear behavior at low temperature is shown to be a finite size effect and the nonlinear behavior at higher temperature, T>${\mathrm{T}}_{\mathrm{KT}}$, is shown to be a finite current effect. These are argued to result from competition between the length scales characterizing the system. The importance of boundary effects is discussed and it is shown that these may dominate the behavior in small arrays.