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

TL;DR

This paper proposes a near-term silicon-based experiment leveraging third quantization to generate nearly deterministic multipartite entanglement among photonic modes, enabling scalable quantum computing without non-deterministic gates.

Contribution

It introduces a practical implementation of third quantization in silicon using antimony donors to produce high-efficiency multipartite entanglement.

Findings

Achieves an upper-bound efficiency of 87.5% for Bell states among 56 pairs.

Demonstrates a method for deterministic entanglement without non-deterministic gates.

Proposes a feasible experiment using silicon chip technology.

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.