Speaker
Description
Entanglement is at the basis of most modern quantum technologies, where continuous degrees of freedom play a special role: They allow for imaging and provide infinite-dimensional Hilbert spaces, promising rich structures that can be exploited for improved resolution and information processing. On the flipside, this complexity requires a different experimental arsenal to access. Reliable verification of such entanglement is an important step toward certifiable quantum resources in free-electron platforms and toward accessing quantum-enhanced imaging techniques. Here, I will present how two techniques from photonic quantum optics can verify spatial entanglement in electron-photon pairs: discretisation via mutually unbiased bases [1] and ghost imaging [2]. We recently implemented the latter, experimentally showing a clear violation (24 standard deviations) of the entanglement bound in a TEM. I will present the background of these techniques and our results, connecting quantum mechanics with electron optics.
[1] P Rembold†, S Beltrán-Romero†, A Preimesberger†, S Bogdanov, IC Bicket, N Friis,
E Agudelo, D Rätzel, P Haslinger State-Agnostic Approach to Certifying Electron-Photon Entanglement in Electron Microscopy. Quantum Sci. Technol. 045003 (10) https://iopscience.iop.org/article/10.1088/2058-9565/adf004
[2] A Preimesberger†, S Bogdanov†, IC Bicket, P Rembold, P Haslinger Experimental Verification of Electron-Photon Entanglement arXiv:2504.13163 (2025) https://arxiv.org/abs/2504.13163