Overview
- Researchers report finite-data secure key generation at 11 kilometers and positive key rates at 100 kilometers.
- Two trapped rubidium atoms at separate nodes were linked via single photons across standard optical fiber to generate shared keys.
- Single-photon interference, quantum frequency conversion to low-loss telecom wavelengths, and noise-suppressed emission preserved high-fidelity entanglement.
- The demonstration extends prior device-independent QKD distances by roughly two orders of magnitude, indicating progress toward metropolitan-scale links.
- The work, led by Bo-Wei Lu with Pan Jianwei’s group at the University of Science and Technology of China, is published in Science.