Superconductivity-related insulating behavior

We present the results of an experimental study of superconducting, disordered, thin films of amorphous indium oxide. These films can be driven from the superconducting phase to a reentrant insulating state by the application of a perpendicular magnetic field (B). We find that the high-B insulator exhibits activated transport with a characteristic temperature, T-I. T-I has a maximum value (T-I(p)) that is close to the superconducting transition temperature (T-c) at B=0, suggesting a possible relation between the conduction mechanisms in the superconducting and insulating phases. T-I(p) and T-c display opposite dependences on the disorder strength.