Weissflog, Maximilian A.Maximilian A.WeissflogFedotova, AnnaAnnaFedotovaTang, YilinYilinTangLaudert, BenjaminBenjaminLaudertAbtahi, FatemehFatemehAbtahiShradha, SaiSaiShradhaShinde, SaniyaSaniyaShindeSaravi, SinaSinaSaraviStaude, IsabelleIsabelleStaudePertsch, ThomasThomasPertschSetzpfandt, FrankFrankSetzpfandtLu, YueruiYueruiLuEilenberger, FalkFalkEilenberger2024-04-102024-04-102023https://publica.fraunhofer.de/handle/publica/46592310.1109/CLEO/EUROPE-EQEC57999.2023.102321372-s2.0-85175739155Transition metal dichalcogenides (TMDCs) thinned-down to the monolayer level allow the realisation of very broad-band, phase-matching free nonlinear devices. A particularly interesting application would be the generation of entangled photon-pairs, which form the backbone of many recent implementations in quantum optics. However, the limited absolute efficiency of monolayers has so far only allowed seeded parametric amplification [1], experimental evidence for the generation of entangled photon-pairs through spontaneous parametric down-conversion (SPDC) remained elusive up to now [2]. A promising route for the realization of broad-band photon-pair sources in van der Waals materials are moderately thicker, yet still phase-matching free layer stacks with preserved noncentrosymmetry [3, 4]. Here, we close the gap of a missing entangled photon-pair source in TMDCs and demonstrate, for the first time to our knowledge, pair generation via SPDC in 3R-MoS2enconference paper