Instabilities in the Voltage—Current Characteristics of Current-Carrying One-Dimensional Superconductors

Abstract

Voltage steps in the transition curves of current-carrying thin wires and whiskers have been observed in the last few years independently by the Cornell group and by us.¹ Figure 1 shows such transition curves of a Sn whisker 0.45 mm in length and 0.65 µm² in cross-sectional area. The voltage across the whisker is plotted vs. temperature, which is measured relative to the mean-field critical temperature: $\Delta (T)$. For low measuring current intensities the transition curves are rather smooth. Increased currents lead to a broadening of the transitions and the step structures appear.