The time of light
PhD defence, Friday 23rd October 2026, Victor Rueskov Christiansen
When does light arrive? We don't notice it, since light travels so quickly, but in fact, light can be delayed similar to how a thunderclap will arrive later than the lightning strike. When light is so dim that only a few particles of light travel in a lightbeam, light reveals its quantum nature, and gains the weird property that it may arrive not at a single moment, but be spread out in time. During Victor Rueskov Christiansen's PhD project, he has investigated the timing of quantum light and characterized how its indefinite time of arrival is changed by the interaction with atoms in matter. He has developed a theory for describing how light travels in quantum networks and used the fact that matter imposes a shift in time onto light to implement devices useful for technologies such as quantum computing.
The PhD study was completed at Department of Physics and Astronomy, Faculty of Natural Sciences, Aarhus University.
This summary was prepared by the PhD student.
Time: Friday, 23rd October 2026 at 14:00
Place: Building 1523, room 318, Lecture Theatre Physics Auditorium, Institute of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C
Title of PhD thesis: Composing Photons in Time: Multimode Nonlinear Interactions in Quantum Networks with Temporal Pulses of Light
Contact information: Victor Rueskov Christiansen, e-mail: victorrc@phys.au.dk, tel.: +45 21 28 14 76
Members of the assessment committee:
Professor Guido Burkard, Department of Physics, University of Konstanz, Germany
Associate Professor Mikkel Heuck, Department of Electrical and Photonics Engineering, Technical University of Denmark, Denmark
Professor Steen Hannestad (chair), Department of Physics and Astronomy, Aarhus University, Denmark
Main supervisor: Professor Klaus Mølmer, Niels Bohr Institute, Copenhagen University, Denmark
Co-supervisor: Professor Jan Arlt, Department of Physics and Astronomy, Aarhus University, Denmark
Language: The PhD dissertation will be defended in English
The defence is public.
The PhD thesis is available for reading at the Graduate School of Natural Sciences/GSNS, Ny Munkegade 120, building 1521, 8000 Aarhus C