Approaching depairing current in dirty thin superconducting strip covered by low resistive normal metal

Abstract

Abstract We experimentally demonstrate that a thin dirty superconducting (S) strip covered by low resistive normal metal (N) approaches closer to the depairing current than a single S strip, which makes its non-linear properties stronger. The obtained result comes from proximity-induced superconductivity in the N layer, its large contribution to the superconducting properties of the SN bilayer and larger sensitivity to the current than that of the host S layer. We argue that such an SN bilayer could be a promising system for different applications based on the current-dependent kinetic inductance. In addition, we also find that in the presence of the N layer the maximal vortex velocity in the resistive state considerably increases.