Magnon hydrodynamics in an atomically thin ferromagnet
Year: 2026
Type: article
Abstract: Strong interactions between particles can lead to emergent collective excitations. Spin waves, known as magnons, have been predicted to reach a strongly interacting hydrodynamic regime, where they form a slow collective density mode. In this work, we isolate exfoliated sheets of chromium trichloride (CrCl 3 ), where magnon interactions are strong, and develop a technique to measure the collective magnon dynamics though nearby nitrogen-vacancy centers in diamond. Thermal magnetic fluctuations generated by monolayer CrCl 3 increase upon decreasing temperature; this anomalous trend may be a consequence of the damping rate of a low-energy magnon sound mode that sharpens as magnon interactions increase with increasing temperature. By measuring the magnetic fluctuations emitted by thin multilayer CrCl 3 in the presence of a variable-frequency drive field, we obtain spectroscopic evidence for this two-dimensional magnon sound mode.
Source: Science
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, Harvard University, Fundación Ramón Areces, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Institute for Theoretical Atomic, Molecular and Optical Physics, Harvard University, Oak Ridge Institute for Science and Education, Intelligence Community Postdoctoral Research Fellowship Program, Multidisciplinary University Research Initiative, Staatssekretariat für Bildung, Forschung und Innovation, Office of Naval Research, Division of Materials Research, Army Research Office
Awards: G1432373144, G1650921002, Amir Yacoby Experimental Investigator Award, G1877134453, NCCR SPIN: Spin Qubits in Silicon, G3155092797, G3715997057, Pablo Jarillo-Herrero Experimental Investigator Award, Tuning the Electronic and Topological Properties of Twisted van der Waals Heterostructures, G6098521345, Non-perturbative approaches to strongly correlated many-body systems, G6404769184, G6631512092, G7173401321, G7452299184, G8510387532, G993971353
OpenAlex ID: W7161978075