Although the prefixes ‘nano’, ‘femto’ and ‘atto’ suggest something small, they often conceal significant physics and impressive technology. This year, two research groups have been awarded the Helmholtz Prize for setting accuracy records in their respective fields. In the category "Precision measurement in fundamental research", researchers from the Physikalisch-Technische Bundesanstalt and the University of Würzburg have succeeded in measuring the quantum anomalous Hall effect at a new level of precision in the nanometre range (a few parts in a billion; nano = 10–9). This has been achieved with special topological, two-dimensional materials. This has opened the door to a new type of electrical quantum resistance standard. In the category ‘Precision Measurement in Applied Metrology’, the prize goes to researchers at the Max Planck Institute for the Physics of Light in Erlangen. Using a completely new technique known as "femtosecond fieldoscopy" (femto = 10–15), optical electric fields of ultrafast phenomena can be analysed with high precision. This opens up new possibilities, for example, for label-free bioimaging and the detection of target molecules in aqueous environments. The two prizes, each endowed with 20 000 euros, will be awarded on 25 August 2026 at a scientific conference at PTB's Berlin Institute.
Quantum anomalous Hall effect
Electrical resistance has been at home in the quantum world for many decades. For example, the ohm unit of resistance is realised via the quantum Hall effect (QHE), in which characteristic plateau values of the resistance occur in strong magnetic fields and at low temperatures. However, this external magnetic field prevents QHE resistance standards from being integrated with quantum voltage standards based on the Josephson effect in a common cryostat, as the Josephson effect does not tolerate magnetic fields.
With the help of novel materials, however, it is possible to generate a quantum Hall effect even without an external magnetic field. This quantum anomalous Hall effect (QAHE) utilises the exotic physical properties of magnetically doped topological insulators (TI). The Helmholtz Prize-winning researchers have succeeded in conducting an experimental "universality test" that achieves resistance values at the highest level of precision and accuracy that match those of the QHE. The magnetically doped material, i.e. the QAHE sample, was produced at the "Institute for Topological Insulators" at the University of Würzburg, while the precision measurements of the Hall resistance were carried out by PTB's "Electrical Quantum Metrology" department.
The results of this work make it possible to establish a new type of electrical quantum resistance standard and to develop a universal integrated quantum metrology system consisting of primary electrical resistance and voltage standards.
Femtosecond Fieldoscopy
Exploring the micro- and nanocosmos in both living and non-living nature requires specialised techniques in microscopy and spectroscopy. Femtosecond fieldoscopy (a term coined by Fattahi herself), developed by Hanieh Fattahi and her independent research group at the Max Planck Institute for the Science of Light, represents a groundbreaking measurement technique that is nothing short of extraordinary. This new method, which utilises ultrashort laser pulses, opens a new window of observation into the microscopic world, where processes – such as the interactions of light with matter – take place very rapidly, i.e. on very short timescales (in the range of femtoseconds or attoseconds). Femtosecond fieldoscopy makes it possible to measure the properties of the electric field of optical radiation under ambient conditions – that is, not just in a vacuum – meaning that biological samples can also be examined.
The impressive characteristics of this method: a measurement bandwidth in the petahertz range, a temporal resolution in the attosecond range, a sensitivity down to femtojoule energies, a dynamic range of over 100 dB, and a spatial resolution below the diffraction limit of light. This method thus combines key properties and represents a versatile tool for spectroscopy, imaging and fundamental investigations of light-matter interactions.
This new measurement technique finds direct application, for example, in the investigation of light-molecule interactions in liquids or in label-free super-resolution microscopy, i.e. without the use of dyes or markers.
The Prize
The Helmholtz Prize is a very special benchmark in the world of metrology. It is regarded as the ‘Nobel Prize of Metrology’ and is thus the flagship award of the Helmholtz Fund, which awards the prize every two years for outstanding scientific and technological research in the field of precision measurement in physics, chemistry and medicine. In each of the two categories, ‘Fundamentals’ and ‘Applications’, it is endowed with 20 000 euros. The Helmholtz Fund e. V. is a unique non-profit association that has always been dedicated to promoting scientific progress in measurement technology. The association bears the name of the co-founder and first president of the Physikalisch-Technische Reichsanstalt (PTR), the exceptional researcher Hermann von Helmholtz.
jes/ptb
Helmholtz Prize 2026: Precision measurements in fundamental research
The prize winners
- Dinesh K. Patel, 1A Cal GmbH, Kassel, formerly PTB, Department of ‘Electrical Quantum Metrology’
- Kajetan M. Fijalkowski, University of Würzburg, Faculty of Physics and Astronomy and Institute for Topological Insulators, Würzburg
- Mattias Kruskopf, PTB, Department of Electrical Quantum Metrology, QuantumFrontiers and Topical Group Quantum Electrical Standards member
Scientific paper
Patel, D.K., Fijalkowski,K.M., Kruskopf, M. et al. A zero external magnetic field quantum standard of resistance at the 10−9 level. Nature Electronics 7, 1111–1116 (2024). https://doi.org/10.1038/s41928-024-01295-w
Contact
Dr Hansjörg Scherer, Division 2.6 ‘Electrical Quantum Metrology’, Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Email: hansjoerg.scherer@ptb.de
Helmholtz Prize 2026: Precision measurements in applied metrology
The prize winners
Srivastava, Andreas Herbst, Kilian Scheffter, Soyeon Jun, Steffen Gommel, Peter Antonius Aldegonda Dullens, Hanieh Fattahi all: Max Planck Institute for the Science of Light, Femtosecond Fieldoscopy
Scientific papers
- Anchit Srivastava, Andreas Herbst, Mahdi M. Bidhendi, Max Kieker, Francesco Tani & Hanieh Fattahi, Near-petahertz fieldoscopy of liquid, Nature Photonics, Volume 18 | December 2024 | 1320–1326, https://doi.org/10.1038/s41566-024-01548-2
- Andreas Herbst, Anchit Srivastava, Kilian Scheffter, Soyeon Jun, Steffen Gommel, Luca Rebecchi, Sidharth Kuriyil, Andrea Rubino, Nicolò Petrini, Ilka Kriegel and Hanieh Fattahi, Ultrafast Nonlinear Dynamics of Indium Tin Oxide Nanocrystals Probed via Fieldoscopy, Advanced Science, 2026, 13, e16818, https://doi.org/10.1002/advs.202516818
Contact
Dr Hanieh Fattahi, Max Planck Institute for the Science of Light, Femtosecond Fieldoscopy, Staudtstraße 2, 91058 Erlangen, Email: hanieh.fattahi@mpl.mpg.de
Author: Jens Simon
