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arXiv · 2502.14806

Passive Demultiplexed Two-photon State Generation from a Quantum Dot

Yusuf Karli·Iker Avila Arenas·Christian Schimpf·Ailton José Garcia Junior·Santanu Manna·Florian Kappe·René Schwarz·Gabriel Undeutsch·Maximilian Aigner·Melina Peter·Saimon F Covre da Silva·Armando Rastelli·Gregor Weihs·Vikas Remesh
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Abstract

High-purity multi-photon states are essential for photonic quantum computing. Among existing platforms, semiconductor quantum dots offer a promising route to scalable and deterministic multi-photon state generation. However, to fully realize their potential we require a suitable optical excitation method. Current approaches of multi-photon generation rely on active polarization-switching elements (e.g., electro-optic modulators, EOMs) to spatio-temporally demultiplex single photons. Yet, the achievable multi-photon rate is fundamentally limited by the switching speed of the EOM. Here, we introduce a fully passive demultiplexing technique that leverages a stimulated two-photon excitation process to achieve switching rates that are only limited by the quantum dot lifetime. We demonstrate this method by generating two-photon states from a single quantum dot without requiring any active switching elements. Our approach significantly reduces the cost of demultiplexing while shifting it to the excitation stage, enabling loss-free demultiplexing and effectively doubling the achievable multi-photon generation rate when combined with existing active demultiplexing techniques.

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Yusuf Karli, Iker Avila Arenas, Christian Schimpf, Ailton José Garcia Junior, Santanu Manna, Florian Kappe, René Schwarz, Gabriel Undeutsch, Maximilian Aigner, Melina Peter, Saimon F Covre da Silva, Armando Rastelli, Gregor Weihs, Vikas Remesh. 2025-02-20. Passive Demultiplexed Two-photon State Generation from a Quantum Dot. https://arxiv.org/abs/2502.14806

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