Switching dynamics in Al/InAs nanowire-based gate-controlled superconducting switch.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• The gate-controlled supercurrent (GCS) effect in superconducting nanostructures is key for developing superconducting transistors.
• Recent studies debate the GCS effect's origin, with leakage-based scenarios being a focus.
• Understanding the microscopic processes and timescales of the GCS effect is vital for its application.

Purpose of the Study:

• To investigate the microscopic origin of the gate-controlled supercurrent (GCS) effect in Al/InAs nanowires (NWs).
• To analyze the dynamics of superconducting-to-normal state switching induced by gate voltage.
• To determine the transport mechanisms responsible for observed fluctuations.

Main Methods:

• Observation of gate-induced two-level fluctuations between superconducting and normal states in Al/InAs NWs.
• Noise correlation measurements to assess the relationship between fluctuations and leakage current.
• Time-domain measurements to analyze the statistical properties (Poissonian) of the fluctuations.

Main Results:

• Gate-induced two-level fluctuations were observed in Al/InAs nanowires.
• Strong correlation found between these fluctuations and leakage current.
• Fluctuations exhibit Poissonian statistics, consistent with stress-induced leakage current (SILC) via inelastic tunneling with phonon generation.

Conclusions:

• The study identifies stress-induced leakage current (SILC) as the dominant mechanism behind the observed gate-induced fluctuations.
• Findings provide a microscopic explanation for the gate-controlled supercurrent (GCS) effect in superconducting nanowires.
• This research offers deeper insights into the switching dynamics of superconducting nanowires under strong gate voltage influence, aiding the development of superconducting electronics.