Record spin waves thanks to flux quanta

October 16, 2025 by Anika Stegeman, Technical University of Braunschweig edited by Lisa Lock, reviewed by Robert Egan This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: fact-checked peer-reviewed publication trusted source proofread Spin waves are considered to be promising candidates for a new form of electronics. Instead of electrons, the focus here is on magnons. These quantized units of spin waves describe how spin precession propagates. Similar to electrons, magnons can transmit information in a conductor. However, they do so with much lower resistance and thus a fraction of the energy consumption.At TU Braunschweig, the Cryogenic Quantum Electronics working group, together with international partners, has now set a new record for the wavelength of excited propagating magnons. The researchers led by Professor Oleksandr Dobrovolskiy used another quasiparticle, fluxons, to excite the spin waves.

The team collaborated with partners from Huazhong University of Science and Technology in China, Goethe University Frankfurt am Main, the University of Vienna and the University of Bordeaux."Fluxons move as magnetic flux quanta of a superconductor at speeds of up to 10 kilometers per second. We succeeded in using the ultra-fast fluxons to excite a spin wave in a neighboring magnet," explains Dobrovolskiy. "This effect can be imagined as similar to the bow wave created by a speedboat in water. Except that our boat is so fast that it literally creates a kind of sonic boom."The team also observed a characteristic feature of this interaction: a so-called Shapiro step in the electrical response of the superconductor. This effect shows that the motion of the fluxons is synchronized with the generated spin waves—an indication of coherent coupling between the two systems. The research is published in the journal Nature Nanotechnology.Beyond fundamental physics, this discovery opens up new possibilities for spin wave–based electronics. "Our results could pave the way for smaller, faster and more efficient components for future information processing systems," says Professor Dobrovolskiy.With the establishment of modern laboratory facilities at the Laboratory for Emerging Nanometrology (LENA) at TU Braunschweig, the group on Cryogenic Quantum Electronics is now ideally positioned to scale hybrid fluxon-magnon systems to atomic dimensions and conduct experiments with individual quantum excitations.More information: Oleksandr V. Dobrovolskiy et al, Moving Abrikosov vortex lattices generate sub-40-nm magnons, Nature Nanotechnology (2025). DOI: 10.1038/s41565-025-02024-w. www.nature.com/articles/s41565-025-02024-w Journal information: Nature Nanotechnology Provided by Technical University of Braunschweig 1 hour ago02 hours ago05 hours ago05 hours ago06 hours ago047 minutes ago1 hour ago1 hour ago1 hour ago1 hour ago1 hour ago1 hour ago1 hour ago2 hours ago2 hours agoJun 21, 2021Jun 24, 2025Oct 26, 2023Jul 9, 2025Aug 1, 2019Apr 4, 20231 hour ago3 hours ago7 hours ago23 hours ago22 hours ago23 hours ago