Phys.org August 19, 2024
Researchers in Singapore have showed that the efficiency of spontaneous parametric down-conversion (SPDC) could be improved by harnessing many-body excitonic interactions present in the non-linear optical crystal. They showed that excitonic resonances and interexciton transitions could enhance the probability of SPDC. They benchmarked their ab initio many-body calculations using experimental polar plots of second harmonic generation in NbOI2, demonstrating the relevance of excitons in the nonlinear response. A strong double-exciton resonance in 2D NbOCl2 led to significant enhancement in the second order susceptibility. According to the researchers their work paves the way for the realization of efficient ultrathin quantum light sources… read more. TECHNICAL ARTICLE
(a) Atomic structure for ML NbO2… Credit: Phys. Rev. Lett. 132, 246902, 14 June 2024