Dynamic resistance of the current-induced intermediate state in superconductors

Abstract

We have measured the in-phase component of the low-frequency ac impedance of the dc current-induced intermediate state in wires of pure and impure type I superconductors. We find that this dynamic resistance of the intermediate state is greater than the normal state resistance of the wire. The linear response theory for the dynamic resistance developed by Gauthier and Rochon provides a reasonable qualitative understanding of our experimental results.

Low-frequency impedance of the direct current induced intermediate state in superconductors: I. The in-phase component

“…It is therefore of some interest to compare theory and experiment in the case of a pure indium wire, and this is done in Fig. 4, where the experimental results on 99.9999% pure indium wire of 0.25 mm diameter are taken from the work of Wiederick et al 9 (their specimen VI). We note that there is reasonably good agreement between experimental measurements and theoretical values obtained by using Eq.…”