By scanning a focused laser beam (diameter~20 and < 1 mW) on Josephson tunnel junctions we observed variations in the zero-voltage current as a function of beam position. We believe that the laser beam at the appropriate power levels serves as a direct probe of the current distribution in the junction. Two types of factors contribute to the non-uniformity of the current distribution. The first is related to the intrinsic non-uniformity of the junction and the second is due to external parameters such as applied magnetic field and temperature. Using this technique, we have directly observed the formation of vortices in a junction in a magnetic field.
No takes yet. Share an insight, caveat, or question.
Lhota et al. (1983) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: