Current-induced suppression of superconductivity in tantalum thin films at zero magnetic field

We report our findings on the mechanism of current-induced suppression of superconductivity in amorphous tantalum films as thin as 5nm under zero applied magnetic field. Our results indicate that the applied current generates magnetic vortices threading the films, and the dynamics of these vortices leads to the suppression of the superconductivity. Our findings also imply that the motion of current-generated magnetic vortices gives rise to nonlinear transport of which characteristics closely resemble those expected in Kosterlitz-Thouless theories with strong finite size effects.