Ultrafast spin-lattice interactions in manganese-based antiferromagnetic intermetallics

• Applicant: Dr. Yoav William Windsor
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564400819

Antiferromagnets are prime candidates for next generation spintronics, offering superior energy efficiency and spin manipulation speeds. They also harbor a wealth of magnetic properties that are absent in conventional ferromagnets (chirality, periodicity…). However, in contrast to ferromagnetic magnetization, these properties are often hard to utilize. Therefore, fundamentally new routes to access and control these unique degrees of freedom are needed. Spin-lattice coupling effects (“SLC”), i.e. interactions between antiferromagnetic (AF) spin order and the atomic arrangement, are a promising route. They are intrinsic and controllable (e.g. via strain, pressure, THz excitation…), and may serve as an energy efficient alternative to B-fields. To realistically harness SLC, insight beyond phenomenology is needed. Nowadays it is well-recognized that ultrafast studies of nonequilibrium states are powerful tools for probing fundamental interactions in solids. To study SLC, this must be applied to the spins AND to the lattice. This project aims to demonstrate this exact approach, by using unambiguous ultrafast probes of (1) the lattice (ultrafast electron diffraction), and of (2) AF spin order (resonant X-ray diffraction). The project will focus on one well-established and clear-cut SLC effect associated with one specific AF spin order. In collaboration with 2 theory groups, it will isolate the Mn-Mn interactions enabling this phase, and the 4f-3d interactions that quench it. We will generalize these observations through the availability of other, isostructural, Mn-based AF materials. Lastly, technologically relevant Mn-based compounds are of environmental importance. Mn is common on earth, and its many unpaired spins may offer an alternative to rare-earth magnetism.

• DFG Programme: Research Grants
• International Connection: Austria, Sweden
• Cooperation Partners: Professor Dr. Arthur Ernst; Professor Dr. Danny Thonig
• Co-Investigator: Professor Dr. Cornelius Krellner