Control of the nonlinear response of nanostructures via path interference effects, i.e., Fano resonances, has been studied extensively. In such studies, a frequency conversion process takes place near a hot spot. Here, we study the case where the frequency conversion process takes place along the body of a nonlinear crystal. Metal nanoparticle–quantum emitter dimers control the down-conversion process, taking place throughout the crystal body, via introducing interfering conversion paths. Dimers behave as interaction centers. We show that two orders of magnitude enhancement is possible, on top of the enhancement due to localization effects. That is, this factor multiplies the enhancement taking place due to the field localization.

中文翻译：

---

通过等离激元-量子发射体混合结构对非线性晶体中的下变频进行精细控制

已经广泛研究了通过路径干扰效应（即，Fano共振）控制纳米结构的非线性响应。在这样的研​​究中，频率转换过程发生在热点附近。在这里，我们研究了频率转换过程是沿着非线性晶体的主体发生的情况。金属纳米粒子-量子发射器二聚体通过引入干扰的转换路径来控制整个晶体中发生的下转换过程。二聚体充当相互作用中心。我们显示，除了由于本地化效应引起的增强之外，还可以实现两个数量级的增强。即，该因素使由于场局部化而发生的增强倍增。