Continuous variable multimode quantum states via symmetric group velocity matching

Configurable and scalable continuous variable quantum networks for measurement-based information protocols or multipartite 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 squeezed modes PDC. We identify type II PDC a single waveguide as best suited process, since multiple with non-negligible amount squeezing obtained. explore, first time, dimensions, usually only set ensure single-mode guiding, an additional design parameter ensuring indistinguishability signal idler fields. investigate here potassium titanyl phosphate (KTP), which offers SGVM at telecommunications wavelengths, but our approach applied any material pump wavelength. This work paves way towards engineering future large-scale regime.