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Abstract: Hybrid light-matter excitations, so-called polaritons, combine the advantages of photons in detection and transmission with the interactions of their matter component. They are therefore not only of great technological interest but also promising tools to probe new states of matter. However, their driven and dissipative nature also poses a challenge for any theoretical description. In this talk I will explain how this challenge can be addressed with non-equilibrium field-theory. Using two examples from my recent research I will provide a small glimpse into the rich many-body physics of polaritons. I will begin by introducing a systematic expansion in the interaction range and leverage it to provide a quantitative description of non-equilibrium phase transitions in photonic waveguides. Subsequently I will address the time-evolution of polaron-polaritons in a two-dimensional semiconductor irradiated by an intense light pulse, highlighting our recent advances towards the quantitative description of the dynamics of highly excited many-body systems.

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Johannes Lang
Seminar Room 0.03, ETP and Zoom (https://uni-koeln.zoom.us/j/96646818958 )
Contact: Lasse Gresista