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DTSTART:20250330T030000
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DTSTAMP:20260424T040548Z
UID:1760688000@ist.ac.at
DTSTART:20251017T100000
DTEND:20251017T110000
DESCRIPTION:Speaker: Jan-Wilke Henke\nhosted by Charles Roques-Carmes\nAbst
 ract: The interaction of free electrons with photons has recently generate
 d considerable interest\, with theoretical studies promising manifold appl
 ications from quantum optical state preparation to enhanced sensing. Advan
 ces in coincidence measurements based on event-based electron detection\, 
 and increased electron-light coupling strength via phase matching and reso
 nant enhancement\, have brought experiments with single electrons and sing
 le photons within reach. The preparation of nonclassical light and the dem
 onstration of electron-photon entanglement are two critical milestones in 
 this ongoing development of free-electron quantum optics.In this talk\, I 
 will present the experimental realisation of these cornerstones: The demon
 stration of electron-heralded photon number state generation and the obser
 vation of free-electron-photon entanglement. Employing integrated photonic
  structures that allow for efficient electron-light scattering [1]\, passi
 ng electrons inside a transmission electron microscope can efficiently int
 eract with the waveguides' optical mode\, creating electron-photon pairs [
 2]. The time- and energy-resolved detection of both particles reveals the 
 resulting correlations between energy-loss electrons and generated photons
 . We study the photon statistics heralded by such loss-electrons in a Hanb
 ury-Brown and Twiss setup\, and observe an anti-bunching that verifies the
  generation of nonclassical photon number states [3]. The underlying inela
 stic electron-light scattering is\, moreover\, expected to induce electron
 -photon entanglement. We implement a quantum eraser scheme [4\,5]\, involv
 ing two partial electron beams that generate orthogonally-polarised photon
 s\, to study electron-path—photon-polarisation entanglement. Observing t
 he interference of the recombined electron beams in coincidence with measu
 rements of the photon polarisation in different bases\, we experimentally 
 implement a state tomography of the full electron-photon quantum state and
  find a violation of the Peres-Horodecki entanglement criterion. This cons
 titutes a first unequivocal demonstration of free-electron-photon entangle
 ment [6\,7].Our results have significant implications for the development 
 of free-electron quantum optics\, demonstrating the feasibility of electro
 n-driven sources of quantum light and enabling quantum-enhanced sensing in
  electron microscopy based on photon-mediated electron entanglement in the
  future.[1] J.-W. Henke et al.\, Nature 600 (2021)\, 653-658[2] A. Feist e
 t al.\, Science 377 (2022)\, 777-780[3] G. Arend et al.\, arXiv:2409.11300
  (2024)\, preprint[4] J.-W. Henke\, H. Jeng & C. Ropers\, Phys. Rev. A 111
  (2025)\, 012610[5] E. Kazakevich\, H. Aharon & O. Kfir\, Phys. Rev. Res. 
 6 (2024)\, 043033[6] J.-W. Henke\, H. Jeng\, M. Sivis & C. Ropers\, arXiv:
 2504.13047 (2025)\, preprint[7] A. Preimesberger et al.\, arXiv:2504.13163
  (2025)\, preprint ***Jan-Wilke Henke studied Physics at the University o
 f Göttingen\, Germany\, and Aarhus University\, Denmark. He received his 
 Master's degree with distinction in 2021 from the University of Göttingen
 . Since mid-2021\, he has been a PhD student in the group of Claus Ropers 
 at the Max Planck Institute for Multidisciplinary Sciences\, working on th
 e development of quantum optics with free electrons in an ultrafast transm
 ission electron microscope.
LOCATION:Mondi 2\, Central Building\, ISTA
ORGANIZER:omerhalil.unal@ist.ac.at
SUMMARY:Jan-Wilke Henke: Exploring single-electron-single-photon interactio
 ns: From heralded quantum light to electron-photon entanglement
URL:https://talks-calendar.ista.ac.at/events/6035
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