CHARGE DISORDER IN GRANULAR ARRAYS

It is demonstrated that already weakly disordered distribution of offs et charges destroys the Kosterlitz-Thouless-Berezinskii charge-unbindi ng phase transition in two dimensional normal and superconducting gran ular arrays and films. Under these conditions the array conductance sh ows a purely thermally activated behavior with the effective Coulomb g ap being decreased due to charge disorder. Our results may account for recent experimental findings in two dimensional arrays of tunnel junc tions.