Switching Currents Limited by Single Phase Slips in One-Dimensional Superconducting Al Nanowires

Abstract

An aluminum nanowire switches from superconducting to normal as the current is increased in an upsweep. The switching current (Is) averaged over upsweeps approximately follows the depairing critical current (Ic) but falls below it. Fluctuations in Is exhibit three distinct regions of behaviors and are nonmonotonic in temperature: saturation well below the critical temperature Tc, an increase as T2/3 at intermediate temperatures, and a rapid decrease close to Tc. Heat dissipation analysis indicates that a single phase slip is able to trigger switching at low and intermediate temperatures, whereby the T2/3 dependence arises from the thermal activation of a phase slip, while saturation at low temperatures provides striking evidence that the phase slips by macroscopic quantum tunneling.

Source-reported materials — not catalogue approval

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