Metal-Insulator Transition in Superconducting Al, Al:Au and Al:Pd Films

Abstract

Metal-insulator transition in disordered superconductors is studied to clarify the roles of spin-orbit and short-range Coulomb interactions. Films of Al and Al:Au exhibit almost the same superconductor (S)-insulator (I) transition with increasing disorder and/or magnetic field, indicating that the former is not important for S–I transition. In Al:Pd films, we observe the effect of short-range Coulomb interaction as the suppression of superconductivity and the tendency for the appearance of a normal phase between S and I.