First Results on Atomically Resolved Spin-Wave Spectroscopy by Transmission Electron Microscopy

Abstract

Spin-wave spectroscopy methods, such as electron-spin-resonance [1], and ferromagnetic resonance [2], are vital tools for materials characterization and chemical monitoring. Together with momentum-sensitive techniques, such as Brillouin light scattering, they are also central to spintronics experiments and the design of spintronic and magnonic devices. Here, we demonstrate a new technique to spatially resolve spin-waves on the single nanometer scale with the potential for atomic resolution by transmission electron microscopy (TEM). The precessional torque of a spin excitation is coupled to a highly coherent electron beam, which reveals localized resonant spin excitations in transmission electron microscopy. This technique can be applied in-situ and in-operando on its own and together with conventional spectroscopy methods. As a model system, we present first results of magnonic networks comprising ferromagnetic nanoparticles [3,4] and observe the spatial distributions of various spin-resonance modes.Financially supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 405553726 – TRR 270 and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant No. 856538, project “3D MAGiC”)