Effect of In-Plane Line Defects on Field-Tuned Superconductor–Insulator Transition Behavior in Homogeneous Thin Film

抄録

Field-tuned superconductor–insulator transition (FSIT) behavior in two-dimensional (2D) isotropic and homogeneous thin films is usually accompanied by a nonvanishing critical resistance at low T. It is shown that, in a 2D film including line defects paralle to each other but with random positions perpendicular to them, the (apparent) critical resistance in low T limit vanishes, as in the one-dimensional (1D) quantum superconducting (SC) transition, under a current parallel to the line defects. This 1D-like critical resistive behavior is more clearly seen in systems with weaker point disorder and may be useful in clarifying whether the true origin of FSIT behavior in the parent superconductor is the glass fluctuation or the quantum SC fluctuation. As a by-product of the present calculation, it is also pointed out that, in 2D films with line-like defects with a long but finite correlation length parallel to the lines, a quantum metallic behavior intervening the insulating and SC ones appears in the resistivity curves.