We evaluated a multi-color two-photon entangled state generated in silicon via spontaneous four-wave mixing (SFWM) as a potential source for bosonic integrated circuits. Spatially entangled photon states were created using a pair of silicon waveguides that produced signal and idler photons through SFWM, allowing us to observe quantum interference between them. Assuming that the frequencies of the multi-color photons were nearly identical, we characterized the generated quantum state by performing quantum state tomography on the bosonic system using a linear optical circuit. This study demonstrates the feasibility of using photon-pair sources generated in silicon via SFWM in bosonic optical circuits and highlights their potential for a wide range of applications in silicon-based optical quantum technologies.
@article{arxiv.2507.09851,
title = {Evaluating a Multi-Color Entangled-Photon Source for a Bosonic Silicon Quantum Circuit},
author = {Koki Nagamachi and Hiroki Yamashita and Mikio Fujiwara and Shigehito Miki and Hirotaka Terai and Takafumi Ono},
journal= {arXiv preprint arXiv:2507.09851},
year = {2025}
}