Local relativistic field quantisation for novel photonics devices


Local relativistic field quantisation for novel photonics devices

Wed, 24/11/2021 - 15:00 to 16:00
Dr Almut Beige
University of Leeds

If you would like to attend this talk in-person in DB114, please register using the Eventbrite link below - this will ensure that we keep numbers below the limit imposed by social distancing.

Dr Almut Beige from the University of Leeds will give a hybrid in-person / online seminar on "Local relativistic field quantisation for novel photonics devices". This will be held simultaneously in DB114 and online, with more information to follow.

For many years, quantum opticians have recognised the importance of local photon theories in the study of locally-interacting quantum systems. Recently, the need for such theories has become even more urgent. For example, highly-localised wave packets which constitute ultra-broadband photons are now frequently used in linear optics experiments [1]. These and other experiments [2,3] clearly demonstrate the need for a better understanding of the quantum physics of tightly confined light fields. In two recent papers [4,5], we have already shown that a local description of light, which must overcome several no-go theorems, is indeed possible. Starting from the assumption that the basic building blocks of the quantised electromagnetic field are local bosonic field excitations with a clear direction of propagation and polarisation, we identified their Schroedinger equation and constructed Lorentz covariant electric and magnetic field observables. Our approach only simplifies to the standard quantum optics description of the electromagnetic field when restricted to a subspace of monochromatic photon states with positive frequencies. Moreover, it is consistent with the Wheeler-DeWitt equation of relativistic quantum field theory and will hopefully pave the way for novel photonic quantum devices.

[1] Ultra-broadband entangled photons on a nanophotonic chip, U. A. Javid, et al., arXiv:2101.04877.
[2] Cavity quantum electrodynamics and chiral quantum optics, M. Scheucher, et al., arXiv:2012.06546.
[3] How to administer an antidote to Schrödinger's cat, J.-R. Alvarez, et al., arXiv:2106.09705.
[4] Quantising the electromagnetic field in position space, D. Hodgson, et al., arXiv:2104.04499.
[5] Locally acting mirror Hamiltonians, J. Southall, et al., J. Mod. Opt. 68, 647 (2021).


Almut Beige obtained her PhD from the University of Göttingen in Germany before holding postdoctoral positions at Imperial College London, the Max Planck Institute for Quantum Optics in Germany and the University of Cambridge. Almut later returned to Imperial College London as a lecturer and in 2005 she moved to the University of Leeds, where she heads up the Theoretical Physics Group today. Her research mainly covers topics in Quantum Optics and Quantum Photonics. She is most known for her expertise in modelling open quantum systems and in addressing issues related to the practical realisation of quantum technology.