Advancements in quantum voltage standards for time-dependent signals

Abstract

Quantum voltage standards based on acJosephson effect are in use in metrology since just a few years after the discovery of the physical effect. The role of quantum standards is now crucial following the SI redefinition in 2019 [1]: electrical units are now defined in function of the fundamental constants e (elementary charge) and h (Planck's constant). The extremely low uncertainty in dc measurements, that can be below 1 nV/V at 10 V [2], is stimulating research to extend application to ac and signals arbitrarily changing with time. Approaching the dc accuracy is challenging, however. The two main technologies used for the generation of non-steady voltage signals are programmable and pulsed Josephson junction arrays. In the following we discuss the main advancements obtained with both technologies and the most recent developments, in particular the advantages of He-free device cooling techniques.

Recent advancements and perspectives of INRiM’s time-dependent Josephson voltage standards

“…In this paper, which extends the research presented in [12], we discuss the main breakthroughs achieved at INRiM utilizing both JVS technologies, along with the latest innovations benefiting from He-free device cooling methods.…”