Hierarchical quasiparticle dynamics in antiferromagnets revealed by time- and momentum-resolved X-ray scattering
Year: 2026
Type: article
Abstract: Energy flows among coupled subsystems are essential for ultrafast dynamics and high-speed technologies. In magnetic materials, spin fluctuations —magnons— mediate these flows in ultrafast magnetism. Yet momentum-resolved access to low-energy magnons governing the microscopic dynamics has been lacking. Using time-resolved resonant diffuse scattering alongside complementary time-resolved X-ray techniques and quantum-kinetic simulations, we unveil the hierarchical energy pathways among correlated systems in the photoexcited antiferromagnet CuO. Above-bandgap excitation triggers near-instantaneous spin disorder, generating non-thermal magnons throughout reciprocal space within femtoseconds. Real-time momentum-resolved tracking reveals picosecond magnon quasi-thermalization, followed by nanosecond recovery via momentum-selective magnon-phonon scattering. The quasiparticle dispersion mismatch creates recovery bottlenecks that control non-equilibrium lifetimes. This microscopic framework transcends phenomenological models and generalizes across antiferromagnetic insulators, establishing design principles for ultrafast control of antiferromagnetic order.
Source: Nature Communications
Authors: Arnau Romaguera, Elizabeth Skoropata, Yun Yen, Biaolong Liu, Abhishek Nag, Shih-Wen Huang, Ludmila Leroy, Katja Sophia Moos, Gian Parusa, Serhane Zerdane, Ritwika Mandal, Céline Mariette, Matteo Levantino, Eugenio Paris, Luc Patthey, Ekaterina Pomjakushina, Urs Staub, Monica Ciomaga Hatnean, Michael Schüler, Elia Razzoli, Hiroki Ueda
Institutions: Paul Scherrer Institute, University of Bremen, École Polytechnique Fédérale de Lausanne, University of Fribourg, Centre National de la Recherche Scientifique, Institut des Matériaux Jean Rouxel, Université de Nantes, Nantes Université, European Synchrotron Radiation Facility, ETH Zurich
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: European Synchrotron Radiation Facility, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Paul Scherrer Institut, National Center of Competence in Research Materials’ Revolution: Computational Design and Discovery of Novel Materials, National Supercomputing Center, Korea Institute of Science and Technology Information
OpenAlex ID: W7129101505
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