A superconducting-nanowire three-terminal electrothermal device.

Area of Science:

• Superconducting electronics
• Nanotechnology
• Quantum computing

Background:

• Superconducting electronics using Josephson junctions offer low-loss signal processing but suffer from magnetic field sensitivity, limited amplification, and manufacturing complexity.
• Existing superconducting devices require specialized fabrication and are sensitive to environmental magnetic fields, hindering widespread adoption.

Purpose of the Study:

• To develop a novel superconducting electrothermal device that overcomes the limitations of Josephson junction-based electronics.
• To demonstrate a new superconducting device, the nanocryotron, with improved performance and manufacturability.

Main Methods:

• Fabrication of a 3-terminal, nanowire-based superconducting electrothermal device (nanocryotron) from a single thin film using electron-beam lithography.
• Characterization of the nanocryotron's gain, impedance driving capability, and operation in ambient magnetic fields.
• Integration and testing of the nanocryotron as a digital logic element (half-adder) and as a digital amplifier for superconducting nanowire single-photon detector pulses.

Main Results:

• The nanocryotron, a Josephson junction-free device, was successfully fabricated using conventional electron-beam lithography.
• Demonstrated gain exceeding 20 and the ability to drive high impedances (100 kΩ).
• Successful operation in typical ambient magnetic fields and application in digital logic and signal amplification circuits.

Conclusions:

• The nanocryotron represents a significant advancement in superconducting electronics, offering a robust alternative to Josephson junction-based devices.
• Its high gain, impedance driving capability, and operation in ambient magnetic fields make it suitable for classical and quantum communications, photon sensing, and astronomical applications.
• The nanocryotron's compatibility with existing superconducting technologies facilitates integration and broadens its potential impact.