Giant Thermoelectrically Generated Magnetic Flux in a Superconducting Bimetallic Loop and a Suggested Direct Measurement of a Normal Thermocurrent in a Superconductor

Abstract

When a counterflow supercurrent is generated in a superconducting bimetallic loop by a thermoelectric quasiparticle current, the phase difference can only be maintained constant if very large surface currents flow. We show that this implies a magnetic flux associated with the loop of order $\frac{r}{\ensuremath{\lambda}}$ ($r$ is the radius of arm perpendicular to $\ensuremath{\nabla}T$ and $\ensuremath{\lambda}$ is the penetration depth) greater than the simple theory suggests, and that this may be used to m\'easure the normal current directly.