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Publication - Dr Raffaele Santagati

    Chip-to-chip quantum teleportation and multi-photon entanglement in silicon


    Llewellyn, DM, Ding, Y, Faruque, II, Paesani, S, Bacco, D, Santagati, R, Qian, Y-J, Li, Y, Xiao, Y-F, Huber, M, Malik, M, Sinclair, GF, Zhou, X, Rottwitt, K, O'Brien, JL, Rarity, J, Gong, Q, Oxenlowe, L, Wang, J & Thompson, MG, 2019, ‘Chip-to-chip quantum teleportation and multi-photon entanglement in silicon’. Nature Physics.


    Exploiting semiconductor fabrication techniques, natural carriers
    of quantum information such as atoms, electrons, and photons can
    be embedded in scalable integrated devices [1–3]. Integrated optics
    provides a versatile platform for large-scale quantum information
    processing and transceiving with photons [3–16]. Scaling
    up the integrated devices for quantum applications requires highperformance
    single-photon generation and photonic qubit-qubit
    entangling operations [17–20]. However, previous demonstrations
    report major challenges in producing multiple bright, pure and
    identical single-photons [8–12], and entangling multiple photonic
    qubits with high fidelity [13–15]. Another notable challenge is to
    noiselessly interface multiphoton sources and multiqubit operators
    in a single device [3–15]. Here we demonstrate on-chip genuine
    multipartite entanglement and quantum teleportation in silicon,
    by coherently controlling an integrated network of microresonator
    nonlinear single-photon sources and linear-optic multiqubit
    entangling circuits. The microresonators are engineered to
    locally enhance the nonlinearity, producing multiple frequencyuncorrelated
    and indistinguishable single-photons, without requiring any spectral filtering. The multiqubit states are processed in a programmable linear circuit facilitating Bell-projection and fusion-operation in a measurement-based manner. We benchmark key functionalities, such as intra-/inter-chip teleportation of quantum states, and generation of four-photon Greenberger-Horne-Zeilinger entangled states. The production, control, and transceiving of states are all achieved in micrometer-scale silicon chips, fabricated by complementary metal-oxide-semiconductor processes. Our work lays the groundwork for scalable on-chip multiphoton technologies for quantum computing and communication.

    Full details in the University publications repository