Threshold fluctuations in a superconducting current-carrying bridge

Abstract

We calculate the energy of threshold fluctuation $\delta F_{thr}$ which triggers the transition of superconducting current-carrying bridge to resistive state. We show that the dependence $\delta F_{thr}(I)\propto I_{dep}\hslash (1-I/I_{dep}{)}^{5/4}/e$, found by Langer and Ambegaokar for a long bridge with length $L\gg \xi$, holds far below the critical temperature both in dirty and clean limits (here $I_{dep}$ is the depairing current of the bridge and $\xi$ is a coherence length). We also find that even 'weak' local defect (leading to the small suppression of the critical current of the bridge $I_c\lesssim I_{dep}$) provides $\delta F_{thr}\propto I_c\hslash (1-I/I_c{)}^{3/2}/e$, typical for a short bridge with $L\ll \xi$ or a Josephson junction.

8 pages,7 figures; typos corrected, argument added in section 2

References in corpus (3)

• Microscopic theory of thermal phase slips in clean narrow superconducting wires
• Threshold Perturbations in Current-Carrying Superconducting Bridges with a Finite Length near the Critical Temperature
• Decay of near-critical currents in superconducting nanowires

Cited by in corpus (1)

• Local thermal fluctuations in current-carrying superconducting nanowires