SIMULATIONS OF CURRENT - DRIVEN 3-DIMENSIONAL JOSEPHSON-JUNCTION ARRAYS

We present Langevin simulations of anisotropic three-dimensional Josep hson arrays driven by an external current. We study the superconductin g phase transition at zero magnetic field, by analyzing both the helic ity modulus and the voltage. We find that there is a well defined phas e transition at any finite current smaller than the Josephson critical current. The critical temperature T-c(I) obtained decreases linearly with current I. We also find that the onset of voltage occurs at tempe ratures smaller than T-c(I). We discuss the consequences of this resul t for the interpretation of recent experiments in the flux transformer configuration.