Thursday, October 13, 2022, 16:00
WHGA Auditorium
Peter Krüger, PTB Berlin
Abstract:
Magnetic fields are ubiquitous in nature and have had a firm place in
technology for a long time. Yet, there are many open questions, needs
for research and emerging new applications. Standards need to be set or
refined, and more accurate calibrations are required by industrial
adopters of new technologies. A particularly interesting challenge
arises at the lowest end of the spectrum of magnetic fields - a place
where also numerous new opportunities lie. With demonstrated
measurement sensitivities beyond the femtotesla (per root Hertz) scale,
the neuronal activities of the brain following a peripheral nerve
stimulus become detectable in a single trial, for example. While even
the foundations of physics can be tested at the frontier of lowest
metrological noise floors, another current trend is to make magnetic
field measurement and imaging viable in application contexts beyond
quantum physics laboratories. We will primarily discuss such
developments in terms of sensor developments, measurement environments
and key use cases. We will focus on atomic gas-based probes of DC and
slowly varying magnetic fields. With trapped ultracold gases, high
resolution field mapping can be achieved with relevance to material
developments such as indium tin oxide replacements for next-generation
touch screens and solar panels. On the other hand, cells containing
thermal atomic vapours can provide highest field sensitivities as part
of optically pumped magnetometers with use in clinical neurology or
current-density imaging in electric vehicle batteries.