Speaker
Description
Spin-dependent phenomena play a central role in determining the quantum and magnetic properties of materials. Techniques such as electron spin resonance (ESR) and nuclear magnetic resonance (NMR) use microwave (MW) radiation to coherently manipulate spin states and have become essential tools for studying spin systems [1,2]. However, these approaches typically measure the averaged response of large spin ensembles and therefore provide limited spatial information, making it difficult to investigate locally varying properties in heterogeneous materials.
Here, we introduce SPINEM (Spin Electron Microscopy), a method that combines MW-driven electron spin excitation with the spatial resolving power of transmission electron microscopy (TEM). In our approach, the static magnetic field of the TEM objective lens polarizes the electron spins in the sample, while a MW resonator integrated into a dedicated TEM holder [3] drives electron spin transitions in the gigahertz range. The applied MW field periodically deflects the probing free-electron beam, while the precessing electron spins generate an additional oscillating magnetic field that further modulates the electron trajectory. Using phase-sensitive detection synchronized to the MW excitation, these weak electron spin-induced deflections can be separated from the primary beam modulation and detected with sensitivity in the picoradian regime. By tuning the external magnetic field through the resonance condition of the sample, SPINEM enables highly sensitive measurements of local spin dynamics [4].
SPINEM combines the spectroscopic strengths of conventional spin-resonance methods with the spatial resolution of electron microscopy, providing localized access to electron spin-dependent properties within a sample. More broadly, the technique opens a pathway toward quantum-enabled electron microscopy approaches capable of probing nanoscale spin phenomena beyond the reach of conventional ensemble-based measurements.
References
[1] A. Bienfait, et al. Nat. Nanotechnol. 2016, 11, 253.
[2] B. Reif, S. E. Ashbrook, L. Emsley, M. Hong Nat. Rev. Method. Prim. 2021, 1, 2.
[3] A. Jaroš, J. Toyfl, A. Pupić, B. Czasch, G. Boero, I. C. Bicket, P. Haslinger Ultramicroscopy 2025, 278, 114224.
[4] A. Jaroš, M. S. Seifner, J. Toyfl, B. Czasch, S. Beltrán-Romero, I. C. Bicket, P. Haslinger ACS Nano 2026, 20, 3443.