近日，英国利兹大学Quentin M. Ramasse团队研究了电子显微镜中的磁振子光谱学。该研究于2025年7月23日发表在《自然》杂志上。

由于热管理和信息传输速度方面的挑战，晶体管的小型化正接近极限。为了克服这些障碍，诸如自旋电子学之类的新兴技术正在被开发出来，这些技术可以研究电子的自旋和电荷。界面或结构缺陷处的局部现象将极大地影响自旋基器件的效率，这使得在纳米尺度和原子尺度上研究自旋波传播的能力成为关键挑战。在相关的长度尺度上研究自旋波（也称为磁振子）的高空间分辨率工具的发展，对于理解它们的性质如何受到局部特征的影响至关重要。

研究组在纳米级主题扫描透射电子显微镜（STEM）上检测大块太赫兹磁振子。通过混合像素电子探测器的高分辨率电子能量损失谱，他们克服了微弱信号在薄NiO纳米晶体中映射太赫兹磁振子激发所带来的挑战。先进的非弹性电子散射模拟证实了他们的发现。这些结果为探测磁振子和探索它们的色散及其由纳米级结构或化学缺陷引起的修饰开辟了新的途径。这标志着磁振学的一个里程碑，为自旋电子器件的发展提供了令人兴奋的机会。

附：英文原文

Title: Magnon spectroscopy in the electron microscope

Author: Kepaptsoglou, Demie, Castellanos-Reyes, Jos ngel, Kerrigan, Adam, Alves do Nascimento, Jlio, Zeiger, Paul M., El hajraoui, Khalil, Idrobo, Juan Carlos, Mendis, Budhika G., Bergman, Anders, Lazarov, Vlado K., Rusz, Jn, Ramasse, Quentin M.

Issue&Volume: 2025-07-23

Abstract: 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.

DOI: 10.1038/s41586-025-09318-y

Source: https://www.nature.com/articles/s41586-025-09318-y