NIST has detailed the requirements for Quantum Locking Ranges (QLR), a standard for Josephson junction devices used in high-precision voltage measurements. These systems rely on fundamental physics constants to create exact voltage pulses that remain stable even if power or temperature changes. The “locking range” identifies the specific operating window where the device produces accurate results, serving as a critical check to ensure the equipment is calibrated correctly.
This technology is currently implemented in devices for measuring DC voltage and generating audio or radio frequency signals, as well as in controlling superconducting quantum bits. By operating within the locking range, these systems maintain accuracy without needing frequent external calibration, which improves the reliability of both measurement tools and quantum processors. The focus is on ensuring the voltage output stays constant over a significant range of settings.
While no specific future dates are given, these systems are already operational with capabilities extending up to 3 GHz. The main benefit is increased confidence in measurement accuracy and better scalability for quantum computers. Optimizing these ranges allows future systems to maintain precision without constant adjustments, supporting the development of more robust quantum technologies.
Keywords: Josephson junctions, quantum-locking range, Josephson voltage standard
