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arXiv · 2404.08378

On-chip quantum interference between independent lithium niobate-on-insulator photon-pair sources

Robert J. Chapman·Tristan Kuttner·Jost Kellner·Alessandra Sabatti·Andreas Maeder·Giovanni Finco·Fabian Kaufmann·Rachel Grange
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Abstract

Generating and interfering non-classical states of light is fundamental to optical quantum information science and technology. Quantum photonic integrated circuits provide one pathway towards scalability by combining nonlinear sources of non-classical light and programmable circuits in centimeter-scale devices. The key requirements for quantum applications include efficient generation of indistinguishable photon-pairs and high-visibility programmable quantum interference. Here, we demonstrate a lithium niobate-on-insulator (LNOI) integrated photonic circuit that generates a two-photon path-entangled state, and a programmable interferometer for quantum interference. We generate entangled photons with $\sim2.3\times10^8$ pairs/s/mW brightness and perform quantum interference experiments on the chip with $96.8\pm3.6\%$ visibility. LNOI is an emerging photonics technology that has revolutionized high-speed modulators and efficient frequency conversion. Our results provide a path towards large-scale integrated quantum photonics including efficient photon-pair generation and programmable circuits for applications such as boson sampling and quantum communications.

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Robert J. Chapman, Tristan Kuttner, Jost Kellner, Alessandra Sabatti, Andreas Maeder, Giovanni Finco, Fabian Kaufmann, Rachel Grange. 2024-04-12. On-chip quantum interference between independent lithium niobate-on-insulator photon-pair sources. https://doi.org/10.1103/n2y3-2bmz

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