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arXiv · 2502.01096

Near-deterministic photon entanglement from a spin qudit in silicon using third quantisation

Gözde Üstün·Samuel Elman·Jarryd J. Pla·Andrew C. Doherty·Andrea Morello·Simon J. Devitt
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Abstract

Unlike other quantum hardware, photonic quantum architectures can produce millions of qubits from a single device. However, controlling photonic qubits remains challenging, even at small scales, due to their weak interactions, making non-deterministic gates in linear optics unavoidable. Nevertheless, a single photon can readily spread over multiple modes and create entanglement within the multiple modes deterministically. Rudolph's concept of third quantization leverages this feature by evolving multiple single-photons into multiple modes, distributing them uniformly and randomly to different parties, and creating multipartite entanglement without interactions between photons or non-deterministic gates. This method requires only classical communication and deterministic entanglement within multi-mode single-photon states and enables universal quantum computing. The multipartite entanglement generated within the third quantization framework is nearly deterministic, where ``deterministic'' is achieved in the asymptotic limit of a large system size. In this work, we propose a near-term experiment using antimony donor in a silicon chip to realize third quantization. Utilizing the eight energy levels of antimony, one can generate two eight-mode single-photon states independently and distribute them to parties. This enables a random multipartite Bell-state experiment, achieving a Bell state with an upper-bound efficiency of 87.5% among 56 random pairs without non-deterministic entangling gates. This approach opens alternative pathways for silicon-based photonic quantum computing.

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Gözde Üstün, Samuel Elman, Jarryd J. Pla, Andrew C. Doherty, Andrea Morello, Simon J. Devitt. 2025-02-03. Near-deterministic photon entanglement from a spin qudit in silicon using third quantisation. https://doi.org/10.1103/fzgd-6tlf

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