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Exciton-Enhanced Spontaneous Parametric Down-Conversion in Two-Dimensional Crystals

Computational Physics 2024-06-18 v3 Materials Science

Abstract

We show that excitonic resonances and interexciton transitions can enhance the probability of spontaneous parametric down-conversion, a second-order optical response which generates entangled photon pairs. We benchmark our ab initio many-body calculations using experimental polar plots of second harmonic generation in NbOI2_2, clearly demonstrating the relevance of excitons in the nonlinear response. A strong double-exciton resonance in 2D NbOCl2_2 leads to giant enhancement in the second order susceptibility. Our work paves the way for the realization of efficient ultrathin quantum light sources.

Keywords

Cite

@article{arxiv.2305.08345,
  title  = {Exciton-Enhanced Spontaneous Parametric Down-Conversion in Two-Dimensional Crystals},
  author = {Fengyuan Xuan and MingRui Lai and Yaze Wu and Su Ying Quek},
  journal= {arXiv preprint arXiv:2305.08345},
  year   = {2024}
}
R2 v1 2026-06-28T10:34:19.137Z