Transport phase diagram for superconducting thin films of tantalum with homogeneous disorder

Abstract

We have constructed a phase diagram in temperature--magnetic-field--disorder space for homogeneously disordered superconducting Ta thin films. We identify the phases by measuring nonlinear transport characteristics that are known to be unique in each phase. The resulting phase diagram shows that the superconducting phase is completely surrounded by the intervening metallic phase prohibiting a direct superconductor-insulator transition at any disorder.