A Thin-Film Cryotron Suitable For Use as an Ultra-Low-Temperature Switch.

Area of Science:

• Low-temperature physics
• Superconducting electronics
• Quantum computing hardware

Background:

• Superconducting circuits are crucial for scientific applications but lack high-current, low-power switches for sub-Kelvin operation.
• Existing switching technologies do not meet the demanding requirements for extremely low temperatures.

Purpose of the Study:

• To develop and demonstrate a cryotron switch optimized for sub-Kelvin temperatures.
• To address the need for high current capacity and low power dissipation in superconducting circuits.

Main Methods:

• Fabrication and characterization of a novel cryotron device.
• Magnetic field application to suppress superconductivity and control switching states.
• Measurement of critical current, control current, leakage current, and switching speed.

Main Results:

• Demonstrated a cryotron switch functional at sub-Kelvin temperatures.
• Achieved a maximum device current of approximately 900 microA in the closed state.
• Switching to the open state required 2 mA of control current with a leakage of ~500 nA.
• Observed switching speeds faster than 200 ns.

Conclusions:

• The developed cryotron is a viable high-current switch for sub-Kelvin applications.
• Potential applications include single-pole, double-throw switches in sensitive low-temperature instrumentation.
• This advancement facilitates the development of more complex superconducting circuits for scientific research.