A Review of the Josephson Voltage Standard and Its Applications

Josephson voltage standards (JVSs), which are based on fundamental physical constants, serve as natural voltage references with exceptional accuracy and long-term stability. They play a foundational role in modern precision metrology and in the development of advanced scientific instruments and measurement technologies. This paper reviews their fundamental principles, historical development, key technologies, and application progress. First, the physical mechanism of voltage reproduction based on the Josephson effect is explained. Building on this basis, the working principles, technical features, and research status of three types of standards, i.e., the conventional Josephson voltage standard (CJVS), the programmable Josephson voltage standard (PJVS), and the Josephson arbitrary waveform synthesizer (JAWS), are described in detail. Second, a series of international key comparisons conducted to validate consistency among different Josephson voltage standards is summarized. Next, novel voltage measurement techniques based on Josephson voltage standards are described, with a focus on their broad applications in establishing quantum-based power standards, enabling precise measurements with Kibble/Joule balances, developing noise thermometers, and calibrating advanced metrology standards. Furthermore, directions for further exploration in quantum measurement techniques based on Josephson quantum voltage standards are discussed, and future prospects are outlined. Finally, conclusions are presented.