On High-Dimensional Twin-Field Quantum Key Distribution

Quantum 9, 1869 (2025).

https://doi.org/10.22331/q-2025-10-01-1869

Twin-Field Quantum Key Distribution (QKD) is a QKD protocol that uses single-photon interference to perform QKD over long distances. QKD protocols that encode information using high-dimensional quantum states can benefit from increased key rates and higher noise resilience. We define the essence of Twin-Field QKD and explore its generalization to higher dimensions. Further, we show that, ultimately, the Twin-Field protocol cannot be generalized to higher dimensions in accordance with our definition.