Development of a Superconducting Differential Double Contour Interferometer

Area of Science:

• Quantum Computing
• Superconducting Devices
• Quantum Metrology

Background:

• Superconducting devices are crucial for quantum technologies.
• Accurate detection of magnetic flux is essential for qubit manipulation.
• Existing devices like SQUIDs have limitations in sensitivity and readout.

Purpose of the Study:

• To investigate the operational principles of the superconducting differential double contour interferometer (DDCI).
• To evaluate the DDCI's performance for ultrasensitive magnetic flux detection.
• To assess the DDCI's suitability for digital readout of superconducting flux qubit states.

Main Methods:

• Fabrication and characterization of the DDCI device.
• Utilizing Josephson junctions for weak coupling between superconducting contours.
• Analyzing the step-like changes in critical current due to magnetic flux variations.

Main Results:

• Demonstrated the DDCI's functionality in detecting magnetic flux.
• Observed step-like changes in critical current corresponding to quantum number changes.
• Showcased the potential for digital readout of flux qubit states.

Conclusions:

• The DDCI is a promising new device for ultrasensitive magnetic flux detection.
• The DDCI offers a potential advantage over traditional superconducting quantum interference devices.
• The DDCI facilitates digital readout for superconducting flux qubits.