Kinetic inductance of superconducting nanostrips with turns

Abstract

Kinetic inductances of superconducting nanostrips with a meander pattern are theoretically investigated based on the London model, and the effect of the current crowding at the turns of the nanostrips is considered. The complex current approach is developed for analytical investigation of the kinetic inductance of nanostrips with turns for thin $d<\lambda$ and narrow $w\ll \lambda^2/d$ superconducting strips, where $d$ is the strip thickness, $w$ is the strip width, and $\lambda$ is the London penetration depth. We show that the current distribution in superconducting nanostrips of $wd\ll\lambda^2$ is identical to that in normal conducting nanostrips of $wd\ll\delta^2/2$, where $\delta$ is the skin depth, and the dependence of the kinetic inductance on the nanostrip geometry is identical to that of the normal resistance. Effects of the edge defects of superconducting strips upon the kinetic inductance are also considered.