Nonlinear current flow and electric field domains in inhomogeneous superconductors

Abstract

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 peaks, while random inhomogeneities can cause a nonmonotonic dependence of J c ( B), negative differential conductivity and electric field domains (superconducting Gunn effect).