Possibility of a zero-temperature metallic phase in granular two-band   superconducting films
  A variational approach is used to study the superconductor-insulator transition in two-band granular superconducting films using a resistance-shunted Josephson junction array model in this letter. We show that a zero-temperature metallic phase may exist between the superconducting and insulator phases which is absent in normal single band granular superconducting films. The metallic phase may be observable in some dirty pnictide superconductor films. 
Bojun Yan and Tai-Kai Ng
cond-mat.supr-con cond-mat.mtrl-sci