Proximitized insulators from disordered superconductors

We present an experimental study of bilayers of a disordered Ag metal layer close to the metal-insulator transition and an indium-oxide film which is on the insulating side of the superconductor insulator transition. Our results show that superconducting fluctuations within the indium-oxide film, that proximitize the underlying metal layer, induce insulating rather than superconducting behavior. This is ascribed to suppression of density of states (due to the superconducting energy gap) for quasiparticles in the proximitized regions. Our results present a manifestation of the proximity effect phenomenon and provide important insight into the nature of the insulating phase of the disorder driven superconductor insulator transition.

Automated summary

We conducted an experimental study on bilayers of a disordered Ag metal layer and an indium-oxide film, which are close to the metal-insulator transition and the superconductor insulator transition, respectively. Our findings demonstrate that superconducting fluctuations within the indium-oxide film lead to insulating behavior rather than superconducting behavior. This is attributed to the suppression of density of states for quasiparticles in the proximitized regions due to the superconducting energy gap. Our results provide important insights into the nature of the insulating phase in the disorder-driven superconductor insulator transition.