Magnon spectroscopy in the electron microscope

• 成果类型: Article
• 署名作者: Kepaptsoglou, Demie; Castellanos-Reyes, Jose Angel; Kerrigan, Adam; Alves do Nascimento, Julio; Zeiger, Paul M.; El Hajraoui, Khalil; Idrobo, Juan Carlos; Mendis, Budhika G.; Bergman, Anders; Lazarov, Vlado K.; Rusz, Jan; Ramasse, Quentin M.
• 署名单位: University of York - UK; University of York - UK; Uppsala University; University of Washington; University of Washington Seattle; United States Department of Energy (DOE); Pacific Northwest National Laboratory; Durham University; University of Leeds; University of Leeds
• 刊物名称: Nature
• ISSN/ISSBN: 0028-2967
• DOI: 10.1038/s41586-025-09318-y
• 发表日期: 2025-08-07
• 关键词: interatomic force-constants; vibrational spectroscopy; spin-waves; dispersion; nio; SCATTERING

摘要

The miniaturization of transistors is approaching its limits owing to challenges in heat management and information transfer speed1. To overcome these obstacles, emerging technologies such as spintronics2 are being developed, which make use of the electron's spin as well as its charge. Local phenomena at interfaces or structural defects will greatly influence the efficiency of spin-based devices, making the ability to study spin-wave propagation at the nanoscale and atomic scale a key challenge3,4. The development of high-spatial-resolution tools to investigate spin waves, also called magnons, at relevant length scales is thus essential to understand how their properties are affected by local features. Here we detect bulk THz magnons at the nanoscale using scanning transmission electron microscopy (STEM). By using high-resolution electron energy-loss spectroscopy with hybrid-pixel electron detectors, we overcome the challenges posed by weak signals to map THz magnon excitations in a thin NiO nanocrystal. Advanced inelastic electron scattering simulations corroborate our findings. These results open new avenues for detecting magnons and exploring their dispersions and their modifications arising from nanoscale structural or chemical defects. This marks a milestone in magnonics and presents exciting opportunities for the development of spintronic devices.