Ultrathin quantum light sources: Scientists show excitonic interactions boost efficiency of entangled photon generation

https://phys.org/news/2024-08-ultrathin-quantum-sources-scientists-excitonic.html

"spontaneous parametric down-conversion generating entangled photon pairs is more efficient when harnessing many-body excitonic resonances/ transitions between excitons present in non-linear optical crystal...  further enhanced when pairs of opposite charges are closer together, or when pump beam frequency closely matches an excitation frequency in the crystal... use of ultrathin crystals eliminates phase matching problem... more easily integrated into hybrid quantum-photonic platforms"

Related: A non-reciprocal phase transition to a many-body, time-dependent phase is proposed to emerge in driven layered ferromagnets
https://www.eurekalert.org/news-releases/1104489