Conductivity in glass phases of disordered granular superconductors in magnetic fields

The electric conductivities in glass phases of three-dimensional (3D) granular superconductors in magnetic fields are examined based on a disordered quantum Josephson-junction array. Contrary to a recent argument of a glass phase with metallic response, a correct inclusion of an Ohmic dissipative dynamics always leads to a glass phase with divergent dc conductivity. With no dissipative term, a metallic glass phase is obtained irrespective of the range of correlation of quenched disorder, i.e., even in the so-called Bose-glass phase with experimentally vanishing resistivity.