Precise in-situ tuning of a superconducting nanowire's critical current using high bias voltage pulses

TL;DR

This paper introduces a method to precisely tune the critical current and temperature of superconducting nanowires in situ using high bias voltage pulses, enabling exact control over their superconducting properties.

Contribution

The study demonstrates a novel in-situ tuning technique for superconducting nanowires via high bias voltage pulses, correlating electrical changes with structural transformations observed through TEM imaging.

Findings

Critical current and temperature can be reduced, minimized, then enhanced by pulsing.

Controlled pulsing allows setting the switching current to a desired value.

Structural transformation from amorphous to crystalline nanowire occurs during pulsing.

Abstract

We present a method for in-situ tuning the critical current (or switching current) and critical temperature of a superconducting nanowire using high bias voltage pulses. Our main finding is that as the pulse voltage is increased, the nanowires demonstrate a reduction, a minimum and then an enhancement of the switching current and critical temperature. Using controlled pulsing, the switching current of a superconducting nanowire can be set exactly to a desired value. These results correlate with in-situ transmission electron microscope imaging where an initially amorphous nanowire transforms into a single crystal nanowire by high bias voltage pulses.