| Hörsaal A1
Prof. Dr. Christian Schneider
”Strong light-matter coupling with two-dimensional materials“
Semiconducting monolayer crystals have emerged as a new platform for studies of tightly bound excitons and many-body excitations in ultimately thin materials. Their giant dipole cou-pling to optical fields makes them very appealing for (nano-) photonic devices. I will discuss the fundamental properties of such two-dimensional materials which are integrated in photonic mi-crocavities, In particular, I will demonstrate that the regime of strong light-matter coupling can accessed, and the effect of bosonic condensation of exciton-polaritons, driven by excitons host-ed in an atomically thin layer of MoSe2 has become within reach .
In turn, high fidelity spin-selective, as well as valley-coherent injection of valley exciton -polaritons is facilitated via quasi-resonant, non-linear spectroscopy. In contrast to former experiments based on excitons in bare MoSe2 monolayer crystals, coherent Light-matter coupling serves as a powerful tool to retain to a very high degree the valley-coherent superposition in the polariton-system. As a consequence, valley- and thus spin-polarized polariton currents manifest in the expanding polariton cloud, which we associate with the recently predicted valley Hall effect in the hybrid light-matter system.
 C. Schneider et al. Nature Communications 9, 2695 (2018)
 M. Waldherr et al. Nature Communications 9, 3286 (2018)