Aarhus Universitets segl

CCQ Lunch Seminar - Simon Panyella Pedersen

Oplysninger om arrangementet


Onsdag 8. februar 2023,  kl. 11:30 - 13:00



Title: Analysing the nonlinearity of atomic arrays using a Green's function approach to time evolution


At a previous CCQ lunch I talked about how sub-wavelength atomic arrays, which have been found to have remarkable linear optical properties, are in themselves only weakly nonlinear due to their collective interaction with photons, despite the underlying nonlinearity of the individual saturable atoms. I showed how our result that by putting together two such arrays, we can recover the nonlinearity via an emergent cavity-like behaviour with a large delay time that allows photons to interact strongly before being emitted from the system. As a complement to this previous numerical analysis, I am now working on the the system analytically using a Green's function approach to calculate the dynamics of the system and the interaction of the photons using the T-matrix. This allows for writing the two-photon correlation functions of the system analytically and perhaps also an effective Hamiltonian for the interacting photons. With this we thus hope to study the nature of the photon-photon interaction and the many-body physics of the system. As an initial step to this, I have performed the analysis for a single array, yielding the two-photon temporal correlation and the two-photon momentum density. I will present this analysis after recapping the previous results.