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MON: Monday Contributed Sessions
MON 13: QIP Implementations: Photons II
MON 13.6: Talk
Monday, September 8, 2025, 17:45–18:00, ZHG001
Demonstration of free-electron-photon entanglement — •Jan-Wilke Henke1,2, Hao Jeng1,2, Murat Sivis1,2, and Claus Ropers1,2 — 1Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany — 2University of Göttingen, 4th Physical Institute, Göttingen, Germany
Most emerging quantum technologies including quantum computation and sensing rely on quantum entanglement. Verifying the entanglement between different quantum system is thus of high relevance. While the interaction of free electrons with optical fields is expected to induce free electron-photon entanglement [1,2], its proof has been an outstanding challenge.
Here, we demonstrate quantum entanglement between free electrons and photons [3]. Harnessing a quantum eraser-type setup [4], we employ dual electron beams in a transmission electron microscope that generate photons of distinct polarisation at a nanostructure. The joint electron-photon state is reconstructed from measurements in different bases and shown to violate the Peres-Horodecki entanglement criterion by more than 7 standard deviations. This proof of electron-photon entanglement will be a cornerstone of free electron quantum optics, enabling quantum-enhanced sensing in electron microscopy.
[1] O. Kfir, Phys. Rev. Lett. 123, 103602 (2019);
[2] A. Konecńa, F. Iyikanat, and F. J. García de Abajo, Sci. Adv. 8, eabo7853 (2022);
[3] J.-W. Henke et al., arXiv:2504.13047 (2025);
[4] J.-W. Henke, H. Jeng & C. Ropers, Phys. Rev. A 111, 012610 (2025)
Keywords: Quantum entanglement; Electron microscopy; Hybrid quantum systems; Electron-driven photon generation