Physik-Kolloquium
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HU Department of Physics
Newtonstraße 15,
12489 Berlin
Lise-Meitner-Haus, Christian-Gerthsen-Hörsaal
Nanomechanical control of light-matter interaction
Prof. Leonardo Midolo
Niels Bohr Institute, University of Copenhagen
Photonic quantum technologies offer a promising route to establish quantum information processing using single photons, enabling future quantum computers to exchange information over long distances via optical fibers. Self-assembled quantum dots (QDs) in InAs/GaAs are a mature technology at the core of (commercially available) deterministic single-photon sources in the near infrared [1] and telecom [2] wavelengths. Embedding QDs in suspended nanophotonic waveguides provides the essential elements to generate and channel photons in photonic chips with high efficiency and low noise, with practical applications in quantum communication [3]. The self-assembly process induces randomness both in spectral and spatial distribution of the emitters, making it hard to scale up beyond single-emitter experiments. In this talk, I will introduce our recent work in using nanomechanical devices [4] and photonic integrated circuits, to compensate the randomness and enable additional "tuning knobs" in waveguide quantum electrodynamics system [5].
[1] R. Uppu et al., “Scalable integrated single-photon source”, Science Advances 6, eabc8268 (2020).
[2] M. Albrechtsen et al., “A quantum-coherent photon-emitter interface in the original telecom band”, arXiv:2510.09251 (2025).
[3] M. Zahidy et al. “Quantum key distribution using deterministic single-photon sources over a field-installed fibre link”, npj Quantum Information 10, 2, (2024)
[4] L. Midolo, A. Schliesser, and A. Fiore, “Nano-opto-electro-mechanical systems”, Nature Nanotechnology 13, 11-18 (2018).
[5] C. Qvotrup et al, “Integration of a GaAs-based nanomechanical phase shifter with quantum-dot single-photon sources”, Physical Review Applied 24, 054016 (2025); C. Qvotrup et al, “Controlling emitter-field coupling in waveguides with a nanomechanical phase shifter”, arXiv:2503.01014 (2025).
The Colloquium will be held in “hybrid” format, i.e., you can join the talk in the lecture hall or via zoom.