We demonstrate conditional entanglement swapping, i.e. teleportation of entanglement, between time-bin qubits at the telecommunication wavelength of 1536.4 nm with high fidelity of 87\%. Our system is deployable, utilizing modular, off-the-shelf, fiber-coupled, and electrically controlled components such as electro-optic modulators. It leverages the precise timing resolution of superconducting nanowire detectors, which are controlled and read out via a custom developed graphical user interface. The swapping process is described, interpreted, and guided using characteristic function-based analytical modeling that accounts for realistic imperfections. Our system supports quantum networking protocols, including source-independent quantum key distribution, with an estimated secret key rate of approximately 0.5 bits per sifted bit.
@article{arxiv.2503.18906,
title = {Entanglement swapping systems toward a quantum internet},
author = {Samantha I. Davis and Raju Valivarthi and Andrew Cameron and Cristian Pena and Si Xie and Lautaro Narvaez and Nikolai Lauk and Chang Li and Kelsie Taylor and Rahaf Youssef and Christina Wang and Keshav Kapoor and Boris Korzh and Neil Sinclair and Matthew Shaw and Panagiotis Spentzouris and Maria Spiropulu},
journal= {arXiv preprint arXiv:2503.18906},
year = {2025}
}