Efficient room-temperature molecular single-photon sources for quantum key distribution

Quantum key distribution (QKD) allows the distribution of cryptographic keys between multiple users in an information-theoretic secure way, exploiting quantum physics. While current QKD systems are mainly based on attenuated laser pulses, deterministic single -photon sources could give concrete advantages in terms of secret key rate (SKR) and security owing to the negligible probability of multi-photon events. Here, we introduce and demonstrate a proof-of-concept QKD system exploiting a molecule-based single-photon source operating at room temperature and emitting at 785 nm. With an estimated maximum SKR of 0.5 Mbps, our solution paves the way for room-temperature single-photon sources for quantum communication protocols.

Automated summary

Quantum key distribution (QKD) is a secure method for distributing cryptographic keys between users, utilizing quantum physics. Current QKD systems use attenuated laser pulses, but using deterministic single-photon sources can improve secret key rate (SKR) and security by eliminating multi-photon events. We introduce and demonstrate a proof-of-concept QKD system with a molecule-based single-photon source operating at room temperature and emitting at 785 nm. Our solution has an estimated maximum SKR of 0.5 Mbps, paving the way for room-temperature single-photon sources in quantum communication protocols.