Nonlinear current flow and electric field domains in inhomogeneous superconductors

We show that both macroscopic planar defects and random inhomogeneities of superconducting properties cause strong local enhancement of electric field , which dramatically changes nonlinear current transport of superconductors . We find that even small planar defects can produce significant voltage pe aks, while random inhomogeneities can cause a nonmonotonic dependence of J( c)(B), negative differential conductivity and electric field domains (super conducting Gunn effect).