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arXiv · 2409.17060

Polarization-encoded quantum key distribution with a room-temperature telecom single-photon emitter

Xingjian Zhang·Haoran Zhang·Rui Ming Chua·John Eng·Max Meunier·James A Grieve·Weibo Gao·Alexander Ling
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Abstract

Single photon sources (SPSs) are directly applicable in quantum key distribution (QKD) because they allow the implementation of the canonical BB84 protocol. To date, QKD implementations using SPS are not widespread because of the need for cryogenic operation, or frequency conversion to a wavelength efficiently transmitted over telecommunication fibers. We report an observation of polarization-encoded QKD using a room-temperature telecom SPS based on a GaN defect. A field test over 3.5 km of deployed fiber with 4.0 dB loss yielded a secure key rate of 585.9~bps. Further testing in a 32.5 km fiber spool (attenuation of 11.2 dB), which exhibited substantially lower polarization mode dispersion, yielded a secure key rate of 50.4 bps. Both results exhibited a quantum bit error rate (QBER) of approximately 5%. These results illustrate the potential of the GaN defects for supporting polarization-encoded quantum communication.

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Xingjian Zhang, Haoran Zhang, Rui Ming Chua, John Eng, Max Meunier, James A Grieve, Weibo Gao, Alexander Ling. 2024-09-25. Polarization-encoded quantum key distribution with a room-temperature telecom single-photon emitter. https://arxiv.org/abs/2409.17060

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