Path-encoded high-dimensional quantum communication over a 2-km multicore fiber

Year: 2021

Authors: Da Lio B., Cozzolino D., Biagi N., Ding Y., Rottwitt K., Zavatta A., Bacco D., Oxenlowe L.K.

Autors Affiliation: Center for Silicon Photonics for Optical Communication (SPOC), Department of Photonics Engineering, Technical University of Denmark, Lyngby, Denmark; CNR – Istituto Nazionale di Ottica (CNR-INO), Firenze, Italy; LENS and Dipartimento di Fisica e Astronomia, Universita di Firenze, Sesto Fiorentino, Italy

Abstract: Quantum key distribution (QKD) protocols based on high-dimensional quantum states have shown the route to increase the key rate generation while benefiting of enhanced error tolerance, thus overcoming the limitations of two-dimensional QKD protocols. Nonetheless, the reliable transmission through fiber links of high-dimensional quantum states remains an open challenge that must be addressed to boost their application. Here, we demonstrate the reliable transmission over a 2-km-long multicore fiber of path-encoded high-dimensional quantum states. Leveraging on a phase-locked loop system, a stable interferometric detection is guaranteed, allowing for low error rates and the generation of 6.3 Mbit/s of a secret key rate.

Journal/Review: NPJ QUANTUM INFORMATION

Volume: 7 (1)      Pages from: 63-1  to: 63-6

More Information: The authors would like to thank D. Rusca for the fruitful discussion. This work is supported by the Center of Excellence, SPOC-Silicon Photonics for Optical Communications (ref DNRF123), by the EraNET Cofund Initiatives QuantERA within the European Union´s Horizon 2020 research and innovation program grant agreement No. 731473 (project SQUARE).
KeyWords: key distribution; entanglement; states
DOI: 10.1038/s41534-021-00398-y