Strategies for generating separable photon triplets in waveguides and ring resonators

TL;DR

This paper analyzes how to generate photon triplets with minimal spectral correlations in waveguides and resonators, aiming to improve their usefulness in quantum computing and information processing.

Contribution

It introduces strategies involving dispersion and pump engineering to reduce spectral correlations in photon triplet sources, demonstrated through realistic device designs.

Findings

Feasibility of few-mode photon triplet generation with current technology

Strategies effectively minimize spectral correlations in designed sources

Potential for practical quantum technology applications

Abstract

Photon triplet sources exhibit non-Gaussian features, a key property for applications in quantum computing and quantum information. However, spectral correlations can limit the performance and detection efficiency of these systems. Motivated by this observation, we present a theoretical analysis of the spectral properties of photon triplets generated through spontaneous third-order parametric down-conversion in photonic devices, and discuss strategies to quantify and minimize such correlations. We propose two approaches: dispersion engineering in waveguides and pump engineering in resonators. We apply these strategies in two realistic source designs, namely a high-index-contrast optical fiber and a silicon nitride microring resonator. Finally, we discuss detection strategies for probing non-Gaussian features of the triplet state. We find that it is feasible to achieve few-mode generation of photon triplets using state-of-the-art experimental systems, a crucial step toward practical applications of photon triplet sources in quantum technologies.