High-dimensional intracity quantum cryptography with structured photons

By Alicia Sit, Frédéric Bouchard, Robert Fickler, J'er'emie Gagnon-Bischoff, H. Larocque, Khabat Heshami, Dominique Elser, Christian Peuntinger, K. Gunthner, B. Heim and 4 more. 2016

403 citations recorded by the source corpus.

Quantum key distribution (QKD) promises information-theoretically secure communication and is already on the verge of commercialization. The next step will be to implement high-dimensional protocols in order to improve noise resistance and increase the data rate. Hitherto, no experimental verification of high-dimensional QKD in the single-photon regime has been conducted outside of the laboratory. Here, we report the realization of such a single-photon QKD system in a turbulent free-space link of 0.3 km over the city of Ottawa, taking advantage of both the spin and orbital angular momentum photonic degrees of freedom. This combination of optical angular momenta allows us to create a 4-dimensional quantum state; wherein, using a high-dimensional BB84 protocol, a quantum bit error rate of 11% was attained with a corresponding secret key rate of 0.65 bits per sifted photon. In comparison, an error rate of 5% with a secret key rate of 0.43 bits per sifted photon is achieved for the case of 2-dimensional structured photons. We thus demonstrate that, even through moderate turbulence without active wavefront correction, high-dimensional photon states are advantageous for securely transmitting more information. This opens the way for intracity high-dimensional quantum communications under realistic conditions.

Subfields: Acoustics and Ultrasonics, Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/b2a17ad9e887322839240885f7cf5f15d089fed2

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In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Orbital Angular Momentum States Enabling Fiber-based High-dimensional Quantum Communication (2018, background): “[5] A.”
Twisted photons: new quantum perspectives in high dimensions (2017, neutral): “Recently, the ﬁ rst high-dimensional quantum states have been used to perform a free-space intra-city QKD experiment over 300 m in Ottawa (see Figure 4) 91 .”
Nonseparable States of Light: From Quantum to Classical (2022, background): “quantum cryptography for encrypting colorful images with structured light photon [167].”
Advances in quantum cryptography (2019, neutral): “[256] A.”