The 2018 Helmholtz Prize in the category of “Applied Metrology” was awarded to a team of researchers from the Physikalisch-Technische Bundesanstalt: Dr. Dietmar Drung, Dr. Martin Götz, Eckart Pesel and Dr. Hansjörg Scherer. Working at the interface between research and practical application, these four scientists have succeeded in developing both methods and instruments that have brought about groundbreaking improvements in the traceable, high-precision measurement and generation of small electrical currents.
Specifically, their project concerns the development of a novel current amplifier, the Ultrastable Low-Noise Current Amplifier (ULCA), and its associated current comparator, which enables the traceable and highly accurate calibration of the ULCA. The characteristics of the ULCA are nothing short of revolutionary: although it is small and portable, it can be used to measure currents with outstanding accuracy (relative uncertainty of 10-7 for a 100 pA current). It can also be used as a reference current source for small electric currents at national metrology institutes – in other words, at the highest metrological level.
These new procedures and devices have improved and expanded calibration and measurement capabilities – for example, those in the semiconductor industry, in environmental measurement technology, in DNA sequencing and in quantum communication. In current research, they are being used in single-electron circuits for the future quantum-based realization of the unit of electric current, the ampere. The ULCA is licenced by PTB and is already being used by a small German enterprise. Clients who have used the ULCA to date include national metrology institutes in the United States, Asia and Europe as well as German calibration laboratories.