Configurable and scalable continuous variable (CV) quantum networks for measurement-based quantum information protocols or multipartite quantum communication schemes can be obtained via parametric down conversion (PDC) in non-linear waveguides. In this work, we exploit symmetric group velocity matching (SGVM) to engineer the properties of the squeezed modes of the PDC. We identify type II PDC in a single waveguide as the best suited process, since multiple modes with non-negligible amount of squeezing can be obtained. We explore, for the first time, the waveguide dimensions, usually only set to ensure single-mode guiding, as an additional design parameter ensuring indistinguishability of the signal and idler fields. We investigate here potassium titanyl phosphate (KTP), which offers SGVM at telecommunications wavelengths, but our approach can be applied to any non-linear material and pump wavelength. This work paves the way toward the engineering of future large-scale quantum networks in the CV regime.

可通过非线性波导中的参数下变频 (PDC) 获得用于基于测量的量子信息协议或多方量子通信方案的可配置和可扩展的连续变量 (CV) 量子网络。在这项工作中，我们利用对称群速度匹配 (SGVM) 来设计 PDC 压缩模式的特性。我们将单个波导中的 II 型 PDC 确定为最适合的工艺，因为可以获得具有不可忽略的挤压量的多个模式。我们首次探索了通常仅设置为确保单模引导的波导尺寸，作为确保信号场和闲散场不可区分的附加设计参数。我们在这里研究磷酸氧钛钾 (KTP)，它在电信波长提供 SGVM，但我们的方法可以应用于任何非线性材料和泵浦波长。这项工作为未来在 CV 机制中设计大规模量子网络铺平了道路。