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arXiv · 2403.13505

Towards an All-Silicon QKD Transmitter Sourced by a Ge-on-Si Light Emitter

Florian Honz·Nemanja Vokić·Michael Hentschel·Philip Walther·Hannes Hübel·Bernhard Schrenk
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Abstract

We demonstrate a novel transmitter concept for quantum key distribution based on the polarization-encoded BB84 protocol, which is sourced by the incoherent light of a forward-biased Ge-on-Si PIN junction. We investigate two architectures for quantum state preparation, including independent polarization encoding through multiple modulators and a simplified approach leveraging on an interferometric polarization modulator. We experimentally prove that the Ge-on-Si light source can accommodate for quantum key generation by accomplishing raw-key rates of 2.15 kbit/s at a quantum bit error ratio of 7.71% at a symbol rate of 1 GHz. We further investigate the impact of depolarization along fiber-based transmission channels in combination with the broadband nature of the incoherent light source. Our results prove the feasibility of a fully-integrated silicon quantum key distribution transmitter, including its light source, for possible short-reach applications in zero-trust intra-datacenter environments.

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Florian Honz, Nemanja Vokić, Michael Hentschel, Philip Walther, Hannes Hübel, Bernhard Schrenk. 2024-03-20. Towards an All-Silicon QKD Transmitter Sourced by a Ge-on-Si Light Emitter. https://arxiv.org/abs/2403.13505

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