A primary quantum current standard based on the Josephson and the quantum Hall effects

Area of Science:

• Quantum Metrology
• Electrical Standards
• Condensed Matter Physics

Background:

• The redefinition of the ampere necessitates a quantum current standard with 10^-8 relative uncertainty.
• Existing single-electron devices struggle to achieve this accuracy for net current flow.
• Previous methods using Ohm's law with Josephson and quantum Hall standards achieved target uncertainty but required error corrections.

Purpose of the Study:

• To present a novel programmable quantum current generator.
• To enable current scaling without errors using a combined quantum electrical circuit.
• To establish a basis for a universal quantum realization of electrical units.

Main Methods:

• Integration of Josephson voltage and quantum Hall standards with a superconducting cryogenic amplifier.
• Development of a programmable quantum electrical circuit for error-free current scaling.
• Utilization of full quantum instrumentation for precise current generation and verification.

Main Results:

• Demonstration of a programmable quantum current generator in the microampere range.
• Achieved quantized current values of ±(n/p)ef_J with relative uncertainties below 10^-8.
• Verified accuracy through full quantum instrumentation, validating the error-free scaling.

Conclusions:

• The developed generator provides a new pathway for accurate quantum current standards.
• This technology can significantly improve high-value resistance measurements.
• It bridges the gap between different quantum current sources, advancing electrical metrology.