Spatiotemporal intermittency in the critical dynamics of dc-driven two-dimensional frustrated Josephson arrays

Abstract

We report the numerical observation of spatiotemporal intermittency in the critical dynamics of two-dimensional frustrated underdamped dc-driven Josephson junction arrays. This intermittency is due to the hopping of the system among the different subcritical metastable states, which are characterized by domain walls separating regions with the symmetry of the ground state. Turbulentlike domains correspond to the regions surrounding the nucleation and decay of these domain walls, or equivalently, to the regions where vortex motion takes place. This intermittency is further signaled by the observation of $1/f$ noise in the high-frequency tail of the power spectrum of the voltage fluctuations, and by the scaling of the characteristic time scale for front propagation with the current. A study of the ground and metastable states of the system is also presented.