Quantum entanglement based communication schemes have many advantages. High-dimensional encoding has been shown to improve robustness and channel capacities in secure quantum communications. The transmission of genuine high-dimensional entanglement under real-world atmospheric link conditions, however, is an ongoing experimental challenge. We report on a proof-of-concept experiment in which we, for the first time, use energy-time and polarization hyperentanglement to transmit 4-dimensional entanglement via a 1.2-km-long intra-city free-space link. We discuss how this approach can be adapted for high-dimensional free-space QKD and report on the progress of ongoing experiments.

Date Published: 9 March 2020
PDF
Proc. SPIE 11272, Free-Space Laser Communications XXXII, 112720N (9 March 2020); doi: 10.1117/12.2542529

Published in SPIE Proceedings Vol. 11272:
Free-Space Laser Communications XXXII
Hamid Hemmati; Don M. Boroson, Editor(s)