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arXiv · 2303.17258

Integrate and scale: A source of spectrally separable photon pairs

Ben M. Burridge·Imad I. Faruque·John G. Rarity·Jorge Barreto
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Abstract

Integrated photonics is a powerful contender in the race for a fault-tolerant quantum computer, claiming to be a platform capable of scaling to the necessary number of qubits. This necessitates the use of high-quality quantum states, which we create here using an all-around high-performing photon source on an integrated photonics platform. We use a photonic molecule architecture and broadband directional couplers to protect against fabrication tolerances and ensure reliable operation. As a result, we simultaneously measure a spectral purity of $99.1 \pm 0.1$ %, a pair generation rate of $4.4 \pm 0.1$ MHz mW$^{-2}$, and an intrinsic source heralding efficiency of $94.0 \pm 2.9$ %. We also see a maximum coincidence-to-accidental ratio of $1644 \pm 263$. We claim over an order of magnitude improvement in the trivariate trade-off between source heralding efficiency, purity and brightness. Future implementations of the source could achieve in excess of $99$ % purity and heralding efficiency using state-of-the-art propagation losses.

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Ben M. Burridge, Imad I. Faruque, John G. Rarity, Jorge Barreto. 2023-03-30. Integrate and scale: A source of spectrally separable photon pairs. https://arxiv.org/abs/2303.17258

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