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

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.